} From: "Paula Sicurello" {patpxs-at-gwumc.edu} } } I'm working in a lab where they have been adding a hypo clearing agent called Orbit Bath into the Kodak rapid fix. Has anybody heard of doing this? I have never heard of this and I can't get the Orbit Bath without promising my first born and pulling a few teeth. } } I'd rather go back to the tried and true method of developing the Kodak 4489 in HRP or D-19, fixing in Kodak Rapid Fix (using A & B), dunking in Hypo clear and washing as usual. } } If someone can come up with a good reason to keep continuing this practice, or even an explanation as to why they even started it, I'm all ears. } Some people use Orbit bath in the fix to cut the time in the fixer. I know of no advantage to it except it speeds up the process a little but not much. The main advantage is for fixing fiber paper so the paper spends less time in the fix and there is less time for fixer to diffuse into the paper.
Gordon
Gordon Couger Stillwater, OK www.couger.com/gcouger
I'm certain that every mount sold by ProSciTech is anodized, and by their very appearance, all other such commercially sold mounts I have seen are anodized too. True the anodized film is very thin. Cheers Jim Darley ProSciTech Microscopy PLUS PO Box 111, Thuringowa QLD 4817 Australia Ph +61 7 4774 0370 Fax:+61 7 4789 2313 service-at-proscitech.com Great microscopy catalogue, 500 Links, MSDS, User Notes ABN: 99 724 136 560 www.proscitech.com
On Saturday, December 01, 2001 9:07 AM, Darrell Miles [SMTP:milesd-at-US.ibm.com] wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } } Anodizing of aluminum can be done in many colors, as } well as a clear coating. I would not expect SEM stubs to be } anodized, as the aluminum oxide coating which forms is an } insulator. This would inhibit the removal of the electron } charge from the sample. The native oxide film is no where } near the thickness of the usual anodized film, and can easily } be broken. The thickness of the anodized film can be } controlled, but it is still an effective insulator. I am fairly } certain that none of the stubs I have ever used were anodized. } } Regards, } Darrell
Tom, The window should be OK IF: 1.) it was protected from mechanical damage (covered effectively) and
2.) the vacuum in the dewar had not deteriorated much while it was cold, ie there was still a vacuum after it warmed up.
The question really is: is the SiLi crystal still good? Upon warming up, it may have gotten contaminated by all of the junk coming out of the zeolite cry-sorption material.
Basically, many detectors do store fairly well, but I would not invest much, if any, money in aquiring one unless is was proved to be good. On the other hand, if you can get it for free, the mounting is correct for your microscope and you're willing to have it rebuilt, it could be a good deal. Contact
"Jim Nicolino" {JNicolino-at-xraydetectors.com}
for possible cost. He's done several rebuilds for some of my customers.
Ken Converse owner Quality Images third party SEM service Delta, PA
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } } I have the chance of receiving a surplus PGT EDS detector. It has not been } used for two years. My question is would the detector's window still be } good? It has been in storage and the detector window has not been kept } cold during these past two years. Any advice is appreciated. } } Tom Bargar } tbargar.unmc.edu } } } }
True, the most likely defect of a soft-vacuum, stored SiLi detector would be a contaminated crystal. This "may" be worth fixing in the USA. In Australia, with the added high freight cost, such detectors become ornaments. At one point I had three SiLi detectors in use and two attractive, high-technology vases with dried flower arrangements. Cheers Jim Darley ProSciTech
On Saturday, December 01, 2001 11:27 PM, Ken Converse [SMTP:qualityimages-at-netrax.net] wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } } Tom, } The window should be OK IF: } 1.) it was protected from mechanical damage (covered effectively) and } } 2.) the vacuum in the dewar had not deteriorated much while it was } cold, ie there was still a vacuum after it warmed up. } } The question really is: is the SiLi crystal still good? Upon warming } up, it may have gotten contaminated by all of the junk coming out of } the zeolite cry-sorption material. } } Basically, many detectors do store fairly well, but I would not invest } much, if any, money in aquiring one unless is was proved to be good. On } the other hand, if you can get it for free, the mounting is correct for } your microscope and you're willing to have it rebuilt, it could be a } good deal. Contact } } "Jim Nicolino" {JNicolino-at-xraydetectors.com} } } for possible cost. He's done several rebuilds for some of my customers. } } Ken Converse } owner } Quality Images } third party SEM service } Delta, PA } } } "tbargar-at-unmc.edu"-at-sparc5.microscopy.com wrote: } } } ------------------------------------------------------------------------ } } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } } -----------------------------------------------------------------------. } } } } } } I have the chance of receiving a surplus PGT EDS detector. It has not been } } used for two years. My question is would the detector's window still be } } good? It has been in storage and the detector window has not been kept } } cold during these past two years. Any advice is appreciated. } } } } Tom Bargar } } tbargar.unmc.edu } } } } } } } }
Do you need to observe the hair cross-sections in great detail, or are you just looking at general morphology? If the latter, then you can cross-section hairs for microscopy by pulling the hairs through a small hole (0.5 or so mm diameter) in a flat metal sheet (can't remember exactly, but maybe 1 mm thick - about the same size as a microscope slide). You will probably need to mix the hairs with cotton so they go through and then stay tight in the hole - they need to be jammed fairly hard in the hole for the next part. Then you just cut off the hairs either side with a sharp razor blade so you get a flat cross-section, mount the metal slide on top of a regular slide, apply a drop of oil (or preferred mountant) to the hairs in the hole, coverslip and observe.
This is one way I've seen zoologists identify hairs and characterise differences. } } I have been asked to prepare some cross sections of hair for inspection with } an optical microscope and not having much experience doing this I have } gotten some advice locally and tried a few things with an old microtome, but } without much success. } } I am wondering if someone on this list could offer me some advice on how to } prepare the hair for the sectioning. So far working with paraffin has not } be successful as the hair seems to not cut well leaving either a hole in the } wax strip or a raised and irregular hair. } } Alternately I would be interested in talking to a lab near Connecticut that } could do this sectioning for me. } } Thanks very much for any help you may be able to offer! } } Richard Shalvoy } Arch Chemicals } Cheshire, CT } 203-271-4394 } rbshalvoy-at-archchemicals.com
cheers, rosemary
Rosemary White Microscopy Centre CSIRO Plant Industry GPO Box 1600 Canberra, ACT 2601 Australia
I would certainly hope that SEM stubs are NOT anodized. Not only does anodizing create an insulating surface, but it also creates a surface with very poor vacuum properties -- anodized parts will pump down slowly due to the gas trapped in the porosity.
Fred Schamber ASPEX, LLC
Jim at Proscitech wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } I'm certain that every mount sold by ProSciTech is anodized, and by their very } appearance, all other such commercially sold mounts I have seen are anodized } too. True the anodized film is very thin. } Cheers } Jim Darley } ProSciTech Microscopy PLUS } PO Box 111, Thuringowa QLD 4817 Australia } Ph +61 7 4774 0370 Fax:+61 7 4789 2313 service-at-proscitech.com } Great microscopy catalogue, 500 Links, MSDS, User Notes } ABN: 99 724 136 560 www.proscitech.com } } On Saturday, December 01, 2001 9:07 AM, Darrell Miles [SMTP:milesd-at-US.ibm.com] } wrote: } } ------------------------------------------------------------------------ } } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } } -----------------------------------------------------------------------. } } } } } } Anodizing of aluminum can be done in many colors, as } } well as a clear coating. I would not expect SEM stubs to be } } anodized, as the aluminum oxide coating which forms is an } } insulator. This would inhibit the removal of the electron } } charge from the sample. The native oxide film is no where } } near the thickness of the usual anodized film, and can easily } } be broken. The thickness of the anodized film can be } } controlled, but it is still an effective insulator. I am fairly } } certain that none of the stubs I have ever used were anodized. } } } } Regards, } } Darrell
I have question: Is it possible to attach EDS detector to old EM400 WITHOUT goniometer ? 1) What one need to change - polepieces to have a hole ? apertures for low bkgnd ? or maybe whole goniometer has to be installed ? 2) Does maybe someone have such detector for give/sell away ??
regards
Krzysztof Herman EO Service Labsoft, ul.Ba¿ancia 45A 02-892 Warszawa, tel/fx: (+48 22)6449753, 6449750 mobile: (+48 601)307456 www.labsoft.com.pl
I am interested in gaining insight into the role of microscopic artifacts in the history of biology. May I impose on list members to contribute particularly glaring examples of misinterpreation of biological facts due to improper microscopic technique? I apologize if this is off-topic or a waste of bandwidth.
Let me provide the first example of a misinterpretation and request your assistance in learning whether this was due to improper use of the microscope, or perhaps even malfeasance: Sidney Hickson's early work on Millepora spp. (Cnidaria:Hydrozoa) fire corals. It seems an incredible lapse, a wholly fabricated natural history account, one that persisted for a considerable period in the fabric of the mythology of biological knowledge. I am interested because reproduction of Millepora platyphylla is the subject of incompleted thesis research of mine.
Hickson published a report on reproduction of "Millepora" around the end of the 19th Century. (Anong his other errors he synonomyized all species of Millepora as ecomorphs of one, M. alcicornis.) In this report, which I do not have available at this time, he included several plates of drawings depicting a putative sequence of reproductive events in this organism. We now understand that his depiction is not even close to the way that Millepora spp. (which were later redesignated as proper individual species through painstaking work by Boschma---notwithstanding the issues recently raised by molecular work) reproduce. The depiction involved dozens of drawings, and a sequence of events based on a misinterpretation of what are apparently artifacts.
Hickson (of Cambridge University) worked extensively in the field, including Indonesia and the Philippines. Was his microscopic work done in the field? Are members of this list enlightened as to Hickson's methods?
Hickson's erroneous drawings of the medusae of Millepora lived on for over 3/4 of a century in virtually every Invertebrate Zoology textbook published until the late 1980s or 1990s. His erroneous description of the medusa of Millepora as lacking a velum led to the designation of a separate branch of hydromedusae by Mayer, as the only hydrozoan medusa without a velum. My unpublished observations in the 1980s as well as published observations by John Lewis of McGill University showed that the medusae of Millepora spp. clearly possess a velum.
I apologize for monopolizing the bandwidth. I hope this is as fascinating a topic for others as for myself, and not considered off-topic.
Alan Davis
-- Alan E. Davis, Science Instructor Marianas High School PMB 30, Box 10006, Saipan, MP 96950 Northern Mariana Islands adavis-at-saipan.com
"An inviscid theory of flow renders the screw useless, but the need for one non-existent." ---Lord Raleigh(aka John William Strutt),or else his son, Jr., who was also a scientist.
We wish to set up a film thickness monitor to satisfy the wants of a user who has to work to ISO 9000 rules. We have a used Varian Auto deposition system Model 985-7009 which has become separated from its manual and which has problems.
Does anyone out there have a copy which we could have/get a copy of?
Thanks. Dr. Mel Dickson, Deputy Director, The Electron Microscope Unit, Adjunct Associate Professor, School of Microbiology & Immunology The University of New South Wales UNSW SYDNEY 2052 Australia. Phone +612 9385 6383 Fax +612 9385 6400 http://srv.emunit.unsw.edu.au/
You are hoping in vain, commercial mounts are anodized, because: 1 The layer is too thin to insulate even at low voltages. SEM have high volts (even specimen currents are many and not fractions of volts) and low currents. No problem. 2 Otherwise the mounts would oxidise and I believe that too is not the best conductor. 3 Al too is porous, if you really care use polished stainless. 4 Does it matter? It would in an ion pumped TEM, but in an SEM? 5 All other suppliers do anodize. That is a better reason than you may think! 6 If we did not, people would buy other supplier's mounts because ours would look "cheap"
Now, I have a question: How long have you and some other people been using anodized mounts and not realised that the nice shiny finish is not a polish. Have you never seen machine finished Al???
If you really want to make a point, place a hundred commercial mounts into the bottom of the SEM chamber and then repeat that experiment with machine finished Al mounts. Record vacuua at various points and run the experiment three times. Report the results. I would be interested to learn if there is any difference. Those hundred plain Al mounts made in a machine shop would be a trifle expensive (you could acid strip the anodizing), but cheaper than most experiments.
Christmas is coming, so lets be charitable: anodized mounts are a good deal and they are very suitable for SEM work. Cheers Jim Darley ProSciTech Microscopy PLUS PO Box 111, Thuringowa QLD 4817 Australia Ph +61 7 4774 0370 Fax:+61 7 4789 2313 service-at-proscitech.com Great microscopy catalogue, 500 Links, MSDS, User Notes ABN: 99 724 136 560 www.proscitech.com
On Monday, December 03, 2001 12:14 PM, Frederick Schamber [SMTP:schamber-at-aspexllc.com] wrote: } I would certainly hope that SEM stubs are NOT anodized. Not only does } anodizing } create an insulating surface, but it also creates a surface with very poor } vacuum } properties -- anodized parts will pump down slowly due to the gas trapped in } the } porosity. } } Fred Schamber } ASPEX, LLC } } Jim at Proscitech wrote: } } } ------------------------------------------------------------------------ } } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } } -----------------------------------------------------------------------. } } } } I'm certain that every mount sold by ProSciTech is anodized, and by their } } very } } appearance, all other such commercially sold mounts I have seen are } } anodized } } too. True the anodized film is very thin. } } Cheers } } Jim Darley } } ProSciTech Microscopy PLUS } } PO Box 111, Thuringowa QLD 4817 Australia } } Ph +61 7 4774 0370 Fax:+61 7 4789 2313 service-at-proscitech.com } } Great microscopy catalogue, 500 Links, MSDS, User Notes } } ABN: 99 724 136 560 www.proscitech.com } } } } On Saturday, December 01, 2001 9:07 AM, Darrell Miles } } [SMTP:milesd-at-US.ibm.com] } } wrote: } } } ------------------------------------------------------------------------ } } } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } } } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } } } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } } } -----------------------------------------------------------------------. } } } } } } } } } Anodizing of aluminum can be done in many colors, as } } } well as a clear coating. I would not expect SEM stubs to be } } } anodized, as the aluminum oxide coating which forms is an } } } insulator. This would inhibit the removal of the electron } } } charge from the sample. The native oxide film is no where } } } near the thickness of the usual anodized film, and can easily } } } be broken. The thickness of the anodized film can be } } } controlled, but it is still an effective insulator. I am fairly } } } certain that none of the stubs I have ever used were anodized. } } } } } } Regards, } } } Darrell
I looking at purchasing a microtome for sectioning polymers, primarily PE. Although I am familiar with microtomes used in biological studies, I have no experience in sectioning polymers. Has anyone sectioned polymers with repeated success? What features are desired for sectioning polymers? Is there a specific knife angle that works well?
KD Derr SEM/Polymer Technician Gas Technology Institute 1700 S Mount Prospect Rd Des Plaines, IL 60018 (847) 768-0505 (phone) (847) 768-0569 (fax) kd.derr-at-gastechnology.org
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I have never used Orbit bath nor Hypo. In fact the former is totally new to me. I have heard of Hypo in the '60s. I was curious and went to the expert. I phoned Kodak Scientific Support (800-225-5352) to find out whether developing the 4489 film in D19 and fixing in Kodak Rapid Fixer is adequate. The answer is "Yes" What about Hypo? He asked, "Who makes it?" He assured me that nothing else is needed after Rapid Fix. Just wash the negs. in water will do.
AnnFook Yang EM Unit, Eastern Cereal and Oilseed Research Centre, Room 2091, Bldg. 20, Central Experimental Farm, Ottawa, Ontario Canada K1A 0C6
Tel: 1-613-759-1638 Fax: 1-613-759-1701
e-mail: yanga-at-em.agr.ca
} } } "Paula Sicurello" {patpxs-at-gwumc.edu} 11/30/01 03:25PM } } } ------------------------------------------------------------------------ The Microscopy ListServer -- Sponsor: The Microscopy Society of America
Hi Listers,
I can't put cute subject headings anymore, so I'm trying not to be too negative ;-).
I'm working in a lab where they have been adding a hypo clearing agent called Orbit Bath into the Kodak rapid fix. Has anybody heard of doing this? I have never heard of this and I can't get the Orbit Bath without promising my first born and pulling a few teeth.
I'd rather go back to the tried and true method of developing the Kodak 4489 in HRP or D-19, fixing in Kodak Rapid Fix (using A & B), dunking in Hypo clear and washing as usual.
If someone can come up with a good reason to keep continuing this practice, or even an explanation as to why they even started it, I'm all ears.
Help clear me of my negative thoughts,
Paula :-)
Paula Sicurello George Washington Univ. Medical Center Dept. of Pathology, Ross Hall rm 505 Electron Microscope Lab 2300 Eye St. Washington, DC 20037 202-994-2930 phone 202-994-2518 fax
To "Anodize" is to subject a metal to an electrolytic action as the anode of a cell in order to coat/deposit a protective or decorative film.
Most aluminium anodization that I have seen creates a dark THICK oxide film (tens to hundreds of nm thick) and is insulating.
I've never seen this on an aluminium SEM stub. Certainly many I've used are electropolished and some (the ones we make here in our machine shop ) are simply milled and mechanically polished. All will at a minimum have a native oxide. All are conductive, and yes (Jim) I've seen polished (electrochemical, mechanical) as well as all ranges of "machine" finished products. These are NOT anodized, they are all simply oxidized by leaving them sit in air. The native oxide which forms is a few tens of angstroms thick and is stable, by definition this is not anodization. I have never heard of anyone calling this process "anodization" should that be what you are referring to.
So... now I'm curious and I would request that the various suppliers who like reply to this list to fill us all in on what you do.
1.) How many of you anodize your stubs (ie. coat), vs electropolish, vs mechanically polish. 2.) If you intentionally anodize, (ie. deposit/coat) your stub with an electrodeposited layer how thick is your film, and what do you anodize it with. 3.) It might also help to define the "anodization" process (if you do this) so that we are all understand what each of you mean in the context of how you make the stubs we purchase.
Orbit bath is very useful. It should not, however, be added to the fixer. The purpose of the hypo clearing agent is to remove the residue of fixer from the negatives after fixing. I strongly recommend that Orbit not be added to the fixing bath.
Good luck,
Gary M. Brown
Jim at Proscitech To: "'Darrell Miles'" {milesd-at-US.ibm.com} , {jim-at-proscitech "Microscopy-at-sparc5.microscopy.com" .com} {Microscopy-at-sparc5.microscopy.com} cc: Subject: RE: Cleaning SEM stubs 12/01/01 05:16 AM Please respond to "jim-at-proscitech .com"
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I'm certain that every mount sold by ProSciTech is anodized, and by their very appearance, all other such commercially sold mounts I have seen are anodized too. True the anodized film is very thin. Cheers Jim Darley ProSciTech Microscopy PLUS PO Box 111, Thuringowa QLD 4817 Australia Ph +61 7 4774 0370 Fax:+61 7 4789 2313 service-at-proscitech.com Great microscopy catalogue, 500 Links, MSDS, User Notes ABN: 99 724 136 560 www.proscitech.com
On Saturday, December 01, 2001 9:07 AM, Darrell Miles [SMTP:milesd-at-US.ibm.com] wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } } Anodizing of aluminum can be done in many colors, as } well as a clear coating. I would not expect SEM stubs to be } anodized, as the aluminum oxide coating which forms is an } insulator. This would inhibit the removal of the electron } charge from the sample. The native oxide film is no where } near the thickness of the usual anodized film, and can easily } be broken. The thickness of the anodized film can be } controlled, but it is still an effective insulator. I am fairly } certain that none of the stubs I have ever used were anodized. } } Regards, } Darrell
Orbit Bath was, as you say, a hypo-clearing agent designed to decrease water wash times while increasing removal of residual fixer from photographic materials after processing. I believe it is no longer made. We recently sent a BUNCH of this stuff to our chemical recycling folks here on campus, because we do so little silver-based photographic work anymore. We retained a small stock.
Although also used for films, Orbit and similar chemicals had their heydey before the routine use of resin-coated papers, which don't absorb chemicals readily. The fiber-based materials used commonly in the past were (and are) very elegant papers and for my money are still the best photographic papers made. However, for anything other than fine-arts use, resin coated papers have rightfully taken over, with the advantages of decreased processing times and chemical consumption.
By way of interesting trivia, I had once heard that some of the fixer-removal products got their start after someone discovered that washing photo materials in seawater after processing (maybe because it was the only water they had available in an emergency) was more efficient than fresh water. Does anyone know if this has a basis in fact or is it just urban myth?
Randy
Randy Tindall EM Specialist Electron Microscopy Core Facility W122 Veterinary Medicine University of Missouri Columbia, MO 65211 Tel: (573) 882-8304 Fax: (573) 884-5414 Email: tindallr-at-missouri.edu Web: http://www.biotech.missouri.edu/emc/
-----Original Message----- } From: Paula Sicurello [mailto:patpxs-at-gwumc.edu] Sent: Friday, November 30, 2001 2:26 PM To: microscopy-at-sparc5.microscopy.com
Hi Listers,
I can't put cute subject headings anymore, so I'm trying not to be too negative ;-).
I'm working in a lab where they have been adding a hypo clearing agent called Orbit Bath into the Kodak rapid fix. Has anybody heard of doing this? I have never heard of this and I can't get the Orbit Bath without promising my first born and pulling a few teeth.
I'd rather go back to the tried and true method of developing the Kodak 4489 in HRP or D-19, fixing in Kodak Rapid Fix (using A & B), dunking in Hypo clear and washing as usual.
If someone can come up with a good reason to keep continuing this practice, or even an explanation as to why they even started it, I'm all ears.
Help clear me of my negative thoughts,
Paula :-)
Paula Sicurello George Washington Univ. Medical Center Dept. of Pathology, Ross Hall rm 505 Electron Microscope Lab 2300 Eye St. Washington, DC 20037 202-994-2930 phone 202-994-2518 fax
We have been using carbon grating replicas for calibrating the magnification of our TEM images for many years. We are in the process of revising our imaging and morphometry protocols. I am not happy with the precision and longevity of the carbon grating replicas. Are there more precise and/or stronger standards for TEM magnification calibration? The final magnifications of our images range from 3,000 -20,000 X.
John M. Basgen Department of Pediatrics University of Minnesota Mayo Mail Code 491 420 Delaware Street SE Minneapolis, MN 55455 USA Phone: 612-625-7979 FAX: 612-626-2791 E-mail: basgen-at-umn.edu
Fred Schamber wrote: =============================================================== I would certainly hope that SEM stubs are NOT anodized. Not only does anodizing create an insulating surface, but it also creates a surface with very poor vacuum properties -- anodized parts will pump down slowly due to the gas trapped in the porosity. ================================================================ Fred is certainly correct.
SPI Supplies has offered "lathe finish" aluminum SEM mounts for nearly thirty years and while we have offered different types of surface finishes, none have ever involved the use of an anodization process. I think the same would be true for the other major manufactures of SEM mounts but I would not want to speak for them since I really don't know exactly what they might or might not have offered over the years. To apply a nonconductive layer to an SEM mount would surely, to me at least, seem quite counter productive.
I think that there is a problem with semantics here. Let me quote from my trusty Webster's New Word Dictionary:
----------------------- an•o•dize to put a protective, often colored, oxide film on (a light metal) by an electrolytic process in which the metal serves as an anode. ----------------------
I was happy to see that my memory was not failing me.
The nornal, naturally occurring oxide layer that forms on bare exposed aluminum is just that: an oxide layer. It is very thin, and generally not enough to cause anyone real complications with charging. If this is the layer people are talking about, then so far as I know, no one (well almost no one) would consider this to be an "anodized" layer. After all, we are talking about a layer intentionally applied, not one that forms naturally upon exposure to air.
I can not comment about what some other firm(s) might be doing, but if they are indeed anodizing their aluminum mounts, they would be growing a nice oxide layer, much thicker than the naturally occurring kind, and one that certainly would exhibit lower conductivity characteristics.
SPI Supplies and to the best of my knowledge, the other leading firms offering SEM mounts, offer aluminum (often times an alloy rather than pure aluminum) that is either "lathe finish", or "polished" or an intermediate finish, called by SPI Supplies as its Luster™ finish. But in no case is an oxide layer being intentionally grown onto the aluminum surface using any kind of anodization process. Details about the SEM mounts produced by SPI Supplies can be found on the SPI Supplies website given below.
Actually, what is involved here is a bit more than just semantics. The naturally formed oxide layer is many times thinner than an anodized layer, and if my memory is right, that naturally occurring layer is on the order of 5 nm or less. Most anodized layers we have seen over the years (by cross- section TEM, for example) are on the order of 500 - 1000 nm (or more), and all exhibit high porosity (and therefore surface area). Until now, I have not been aware that anyone would call the naturally formed oxide layer to be an anodized layer, but perhaps I am not keeping up with the more modern use of the term. Someone help me out if I am wrong about this.
Chuck
=================================================== Charles A. Garber, Ph. D. Ph: 1-(610)-436-5400 President 1-(800)-2424-SPI SPI SUPPLIES FAX: 1-(610)-436-5755 PO BOX 656 e-mail: cgarber-at-2spi.com West Chester, PA 19381-0656 USA Cust. Service: spi2spi-at-2spi.com
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I will be the first to admit that I am not an expert on either SEM stubs or anodizing, but I have had very negative experience with the latter in vacuum systems. I once designed some relatively small black-anodized parts into a SEM and spent considerable time trying to find out why we had a degradation in pumping speed -- finally, someone wiser than me sanded off the anodizing and the vacuum was fine. So I have, in effect, done the experiment you describe -- ordinary machined aluminum parts are vastly superior to anodized aluminum parts in terms of their vacuum properties in my experience (and I did some followup experiments in a test system employed specifically to measure vacuum properties of materials and confirmed that a little bit of anodizing is a surprisingly bad thing). If one actually did the experiment you propose with one hundred anodized stubs, my bet is that you would be shocked (but in order to do the experiment, I think you would first have to have MOST stubs anodized). It is not a question of the mere "roughness" of the surface.Apparently the anodizing process creates very tiny interstices which hold the dye, and this is what causes the problem -- or so I have assumed. I suppose it could be the dye itself -- I never tried the experiment on "clear anodized" parts.
When I look at catalog advertisements for aluminum SEM stubs, I always see reference to various degress of polishing, and don't recall ever seeing reference to anodizing. Reading the description, it certainly sounds like they are just pure uncoated aluminum -- I've never looked at the ones you sell.
} From an electrical standpoint, I also really wonder how anodizing could work. I know that anodizing must be avoided on electrical cabinetry because one cannot establish reliable contacts (a different surface treatment process is used on aluminum instead). I'm sceptical about the "thin coating" concept since it is my understanding that it is precisely the insulating layer which protects the surface from oxidation. Any amount of insulation on a SEM stub would be a big problem. (Of course, the same thing can be said about the thin oxide layer that naturally forms when aluminum is exposed to air.) But it is my understanding that anodizing is a process which modifies the surface, not a simple "coating" which can be "thin".
My negative opinions about anodizing for vacuum systems aren't just mine -- in fact, I thought they were "common knowledge". For example, I refer you to the very informative vacuum information site maintained by Roy Schmaus at the University of Alberta http://nyquist.ee.ualberta.ca/~schmaus/vacf/index.html Under Basics/An Introduction to Materials for use in Vacuum we find the following statement: "Aluminum that will be exposed to vacuum should never be anodized due to serious outgassing problems." Under "References" on the same page he notes: "I recently had a call from someone who has used Anodized Aluminum as an INSULATOR down into the ultra high vacuum region. Admittedly the pieces used were very small and INITIAL OUTGASSING WAS A PROBLEM but low costs were a major advantage." [my EMPHASIS added]
So given my own negative experience and the congruent remarks of others who work in this field, I have long understood that anodizing was something to always avoid in vacuum systems -- and I've ASSUMED that applied to SEM stubs. Am I wrong?
How DO polished stubs stay so shiny? I've wondered the same. However, anodized parts I have seen always have a kind of "matte" appearance, rather than a high gloss in any case.
So, though it is entirely possible that I will learn something from this discussion that I did not know previously (it would hardly be the first time), my limited grasp of the subject still convinces me that SEM stubs should NOT be anodized. But how do they retain their surface finish and conductivity? Your response suggests that you manufacture SEM stubs and call out an anodized surface -- did I read this correctly? Or are you purchasing stubs which you assume are anodized? I really would be interested if someone who is in the business of manufacturing these things could comment directly to this -- without disclosing proprietary information of course.
"Charity" in view of the season notwithstanding, I consider this a matter of considerable practical importance. If I am in error about this, I want to know it, since a non-insulating, non-outgassing, but still protective anodizing surface would be a very good thing. If I am correct, then others reading this exchange should know that anodizing is something that should be scrupulously avoided in vacuum systems (SEM and otherwise). This is the kind of thing where a little misinformation can cause a great deal of grief, so getting to the bottom of this will presumably be a good thing for everyone. I'm prepared to learn from new facts, if someone can put them on the table.
Fred Schamber ASPEX, LLC
Jim at Proscitech wrote:
} You are hoping in vain, commercial mounts are anodized, because: } 1 The layer is too thin to insulate even at low voltages. SEM have high volts } (even specimen currents are many and not fractions of volts) and low currents. } No problem. } 2 Otherwise the mounts would oxidise and I believe that too is not the best } conductor. } 3 Al too is porous, if you really care use polished stainless. } 4 Does it matter? It would in an ion pumped TEM, but in an SEM? } 5 All other suppliers do anodize. That is a better reason than you may think! } 6 If we did not, people would buy other supplier's mounts because ours would } look "cheap" } } Now, I have a question: How long have you and some other people been using } anodized mounts and not realised that the nice shiny finish is not a polish. } Have you never seen machine finished Al??? } } If you really want to make a point, place a hundred commercial mounts into the } bottom of the SEM chamber and then repeat that experiment with machine finished } Al mounts. Record vacuua at various points and run the experiment three times. } Report the results. I would be interested to learn if there is any difference. } Those hundred plain Al mounts made in a machine shop would be a trifle } expensive (you could acid strip the anodizing), but cheaper than most } experiments. } } Christmas is coming, so lets be charitable: anodized mounts are a good deal and } they are very suitable for SEM work. } Cheers } Jim Darley } ProSciTech Microscopy PLUS } PO Box 111, Thuringowa QLD 4817 Australia } Ph +61 7 4774 0370 Fax:+61 7 4789 2313 service-at-proscitech.com } Great microscopy catalogue, 500 Links, MSDS, User Notes } ABN: 99 724 136 560 www.proscitech.com } } On Monday, December 03, 2001 12:14 PM, Frederick Schamber } [SMTP:schamber-at-aspexllc.com] wrote: } } I would certainly hope that SEM stubs are NOT anodized. Not only does } } anodizing } } create an insulating surface, but it also creates a surface with very poor } } vacuum } } properties -- anodized parts will pump down slowly due to the gas trapped in } } the } } porosity. } } } } Fred Schamber } } ASPEX, LLC } } } } Jim at Proscitech wrote: } } } } } ------------------------------------------------------------------------ } } } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } } } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } } } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } } } -----------------------------------------------------------------------. } } } } } } I'm certain that every mount sold by ProSciTech is anodized, and by their } } } very } } } appearance, all other such commercially sold mounts I have seen are } } } anodized } } } too. True the anodized film is very thin. } } } Cheers } } } Jim Darley } } } ProSciTech Microscopy PLUS } } } PO Box 111, Thuringowa QLD 4817 Australia } } } Ph +61 7 4774 0370 Fax:+61 7 4789 2313 service-at-proscitech.com } } } Great microscopy catalogue, 500 Links, MSDS, User Notes } } } ABN: 99 724 136 560 www.proscitech.com } } } } } } On Saturday, December 01, 2001 9:07 AM, Darrell Miles } } } [SMTP:milesd-at-US.ibm.com] } } } wrote: } } } } ------------------------------------------------------------------------ } } } } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } } } } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } } } } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } } } } -----------------------------------------------------------------------. } } } } } } } } } } } } Anodizing of aluminum can be done in many colors, as } } } } well as a clear coating. I would not expect SEM stubs to be } } } } anodized, as the aluminum oxide coating which forms is an } } } } insulator. This would inhibit the removal of the electron } } } } charge from the sample. The native oxide film is no where } } } } near the thickness of the usual anodized film, and can easily } } } } be broken. The thickness of the anodized film can be } } } } controlled, but it is still an effective insulator. I am fairly } } } } certain that none of the stubs I have ever used were anodized. } } } } } } } } Regards, } } } } Darrell
Surely the most famous misinterpretations of microscopical observations are those recorded in drawings made by preformationists in the 18th Century of the "homunculus" in the head of human sperm. Several of these drawings are commonly reprinted in textbooks as cautionary examples.
For a discussion of a common histological artifact see "Multinucleate Plant Cells" by Burkholder and Mc Veigh (1941) in vol. 68 of the Bulletin of the Torrey Botanical Club p. 395.
You should also check out what the web has to offer on the history of Royal Rife and the Rife Microscope.
Finally, evidence seems to be accumulating that the "nanobacteria" observed by EM in the martian meteorite are artifacts.
Mike Dalbey
Lecturer in Biology University of California, Santa Cruz
Some subscribers to the list did not see this message the first time I posted it. At Nestor's suggestion, I am re-posting it, with apologies to those who did see it the first time!
Tony G-R
-------------
The New England Society for Microscopy (NESM) will be holding it's 35th Annual Fall Symposium at UMASS-Lowell in Lowell, Massachusetts on Friday, Dec. 7, 2001.
The meeting will begin at 12 Noon with Registration in the Mil Conference Center-Wannalancit Building (North Campus).
There will be 3 Sessions: A special student session beginning at 1:05 pm with 4 presentations, followed by a Poster session and coffee break.
Session II (Biological) begins at 2:20 pm and has as it's speaker, Ken Moore (University of Iowa), the National MSA Speaker. His talk will be: "Application of Microscopy Techniques to the Study of Genetic Therapy Research".
Another Poster Session and Afternoon Coffee Break will follow at 3:20 pm.
Session III (Materials Science) will begin at 3:40 pm and have 2 speakers: Elen Humphreys from M.I.T. and Koichi Nishikida from Thermo Spectra-Tech.
The Annual Business Meeting will convene at 5:00 pm and will include the election of NESM officers for 2002.
A Dinner and after-dinner speaker will follow at 6 pm.
Advance registration is due by Friday, November 30th. Registration after November 30th will NOT include dinner. The registration for NESM members is $10.00 and $25.00 for non-members. Dinner is $15.00 extra.
For more detailed information, please contact Mary McCann, NESM Treasurer at mccanns-at-tiac.net or NESM's website: http://www.msa.microscopy.com/MSALAS/NESM/NESMHome.htm
** Anthony J. Garratt-Reed ** MIT Room # 13-1027 ** 77 Massachusetts Avenue ** Cambridge, MA 02139-4307 ** USA ** ** Phone: (+) 1-617-253-4622 ** Fax: (+) 1-617-258-6478 **
---------- From: Griffiths, Vern Sent: Friday, November 30, 2001 11:34 AM To: 'microscopy-at-sparc5.microscopy.com' Subject: RE: Cleaning SEM stubs
We have a metallographic lab next door. I've cleaned and reused hundreds of stubs. After I've accumulated 50 - 100 stubs, I put them in an ultrasonic cleaner in acetone for five to ten minutes. This gets off most carbon paint and adhering specimen stuff and the like. Then I take the stubs, one at a time, and polish/grind them on a 320 grit silicon carbide paper on a standard metallographic polishing wheel. I generally do the sides and one end, sometimes (rarely) both ends and they look like new. A relatively negligible amount of material is removed so that I have stubs on which this operation has been performed many times. Each stub may require 30 - 60 seconds total so that you may find this time consuming but for us it's worth the effort. I don't know what the black stuff you mention is, but aluminum will corrode in aqueous solutions and the Alconox is probably alkaline enough to aggravate the situation. Vern Griffiths, Montana Tech ---------- From: jmkrupp-at-cats.ucsc.edu {mailto:jmkrupp-at-cats.ucsc.edu} [SMTP:jmkrupp-at-cats.ucsc.edu] {mailto:[SMTP:jmkrupp-at-cats.ucsc.edu]} Sent: Thursday, November 29, 2001 5:35 PM To: Microscopy-at-sparc5.microscopy.com {mailto:Microscopy-at-sparc5.microscopy.com} Subject: Cleaning SEM stubs ------------------------------------------------------- The Microscopy ListServer -- Sponsor: The Microscopy Society of America To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com {mailto:ListServer-at-MSA.Microscopy.Com} On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html {http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html}
I heard on the radio that the economy is in a recession, so I figured I had better get busy and try to save money and recycle some supplies. I also had a big box of used SEM stubs and thought I could start there.
The stubs are left over from various projects, some have silver paint, some with double stick tape, etc. I thought I could loosen things up a bit by soaking them in water and/or an Alconox solution. This fit in very well with my plan for recycling since the plan was to let them soak until the recession is over.
Since there was no way to know when things would return to normal, I put some into an ultrasonic cleaner with Fisher Ultrasonic Cleaning solution. Says it is safe for aluminum and other things.
Now I have a problem. The stubs turned pretty ugly. Big black stains all over the place. Looks like some reaction between the Al and the Alconox. Stubs in plain water are not so bad. Ultrasonic cleaner can't remove the black stuff. I can polish off the black stuff, but that wasn't part of the plan. This was supposed to be simple.
I don't think the black stuff affects the functioning of the stub, it just looks ugly and means I have to explain to some users that they are just as good as the few shiny ones left in the drawer (stubs that is, not users).
So tell me oh mighty metal and materials experts, what is the black stuff, why did it appear, and is there any easy way to get rid of it? Or is this some kind of plan to pull the economy back up to speed by making me buy a bunch of shiny new SEM stubs?
Jonathan Krupp Microscopy & Imaging Lab University of California Santa Cruz, CA 95064 (831) 459-2477 jmkrupp-at-cats.ucsc.edu {mailto:jmkrupp-at-cats.ucsc.edu}
John M. Basgen wrote: =============================================================== We have been using carbon grating replicas for calibrating the magnification of our TEM images for many years. We are in the process of revising our imaging and morphometry protocols. I am not happy with the precision and longevity of the carbon grating replicas. Are there more precise and/or stronger standards for TEM magnification calibration? The final magnifications of our images range from 3,000 -20,000 X. ================================================================ Have you seen the MAG*I*CAL™ TEM Calibration Specimen as described on the SPI website, page URL http://www.2spi.com/catalog/standards/magical.html
It seems to get around most of the problems associated with the carbon grating replicas and although nothing is forever, it is quite robust in comparison and should last quite a long time.
Chuck
=================================================== Charles A. Garber, Ph. D. Ph: 1-(610)-436-5400 President 1-(800)-2424-SPI SPI SUPPLIES FAX: 1-(610)-436-5755 PO BOX 656 e-mail: cgarber-at-2spi.com West Chester, PA 19381-0656 USA Cust. Service: spi2spi-at-2spi.com
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As far as the finish goes, I have machined aluminum myself, and have left a far "shinier", superior finish on the aluminum, compared to what the normal SEM stubs show. I must admit that I have never had any from ProSciTech, but from your statement, they are very similar. It must be more than the finish that makes you spend the money to have them anodized.
True, the freshly machined aluminum forms a native oxide fairly fast, but it is nowhere near the thickness of the oxide formed by anodizing.
I'm not trying to be uncharitable, I am just surprised that someone would go to the expense of anodizing SEM stubs, which also forms an insulating film. I have made my own mounts for specific uses which are not anodized, and they don't look any different from the commercially acquired ones, even after years of use. Of course, the proper alloy needs to be used, or you WILL have vacuum problems.
Food Structure & Functionality Forum Symposium 2002 May 5 to 8, 2002, Palais des Congres de Montreal, Montreal, Quebec, Canada
An international symposium leading Food Structure & Functionality studies through the 21st century
"webaddress at the AOCS site (http://www.aocs.org/member/division/fsff/index.htm)", bulletin board (http://www.aocs.org/ubbcgi/ultimatebb.cgi
held in conjunction with the 93nd AOCS Annual Meeting & Expo (www.aocs.org)
The mandate of the Food Structure & Functionality Forum : "To promote global collaboration between Food and Agriculture professionals in Structure and Functionality disciplines by facilitating and providing a forum for exchange of knowledge, expertise and research findings". The symposium has two themes: * new and novel approaches (including microscopy, rheology and spectroscopy) to the study of structure-function relationships in foods; * food system studies covering any part of the processing chain - from the raw material to the final product, and including trouble shooting.
Tentative Technical Program Schedule (as of December 3rd, 2001)
Sunday, May 5th Short Course - Understanding structure-function relationships in food systems through specific localisation methods and microscopy. Contact: Marcel Paques (Paques-at-nizo.nl)
Monday, May 6th-Morning Opening of symposium - Opening remarks
Plenary Speaker and presentation of Division Achievement Award
Dairy Applications Session. Chairs: Mark Auty, Dairy Products Research Centre, TEAGASC, Ireland (mauty-at-moorepark.teagasc.ie ) and Harjinder Singh, Massey University, NZ (H.Singh-at-massey.ac.nz)
Some Observations of a Microscopist, Author, and Reviewer on Structural Studies of Milk Products. M. Kalab, Agriculture and Agri-Food Canada, Canada
Effect of Emulsifiers and Processing Conditions on Microstructure of Milk Fat/Sunflower Oil Blends. S. Martini1, M. Cerdeira1, C. Puppo1, R.W. Hartel2, and M.L. Herrera1,3, 1CIDCA, UNLP, CONICET, Argentina; 1University of Wisconsin-Madison, USA; 3University of Buenos Aires, Argentina
Texturization of Dairy-Based Spreads. Y. Shi, B. Liang, and R.W. Hartel, University of Wisconsin-Madison, USA
Localization of Whey and Casein in Cheeses Using Microscopy and Immunochemistry Techniques. Y. Wang and D. Pechak, Kraft Foods, U.S.A
Manufacturing Yoghurt Structures with a Predicted Consumer Preference. M Langton and A. Astrom, SIK, Sweden
Dynamic Confocal Imaging of Tension and Fracture in Composite Food Materials. D.P Ferdinando1, K.P Plucknett2, and V. Normand3, 1Unilever Research, UK; 2DERA, UK; 3Firmenich SA, Switzerland
TBA - Topic: Dairy powders/caramels. C. Attapattu, University of Wisconsin, USA
Monday, May 6th - Afternoon Colloidal and Interfacial Sciences Session. Chairs: Marcel Paques (Paques-at-nizo.nl ) and David Pechak (Dpechak-at-kraft.com)
Protein Polysaccharide Interactions. C.G. De Kruif, NIZO Food Research, Netherlands (keynote speaker)
To Be Announced. B. Campbell, Kraft Foods, USA
Structure in Heat Treated Low_Fat Emulsions. R. Ofstad and V. Hoest, MATFORSK, Norway
Fatty Acid Salts-Induced Gels of Food Proteins: Their Rheological Properties and Structural Changes of the Proteins During Gelation. N. Yuno-Ohta, Nihon University, Japan
Wheat Gluten Proteins. A.S. Tatham, IACR Long Ashton research Station, United Kingdom
Interfacial Composition and Stability of Oil in Water Emulsion formed with Mixtures of Milk Proteins and Polysaccharides. H. Singh and Y. Hemar, Institute of Food, Nutrition and Human Health, Massey University, NZ
Dedicated Poster Session
Division Board Meeting
Tuesday, May 7th - Morning Agricultural Applications of Microscopy and Imaging Session/ joint with Feed Microscopy Division. Topic: Food Contamination contacts: Mark Auty, Dairy Products Research Centre, TEAGASC (mauty-at-moorepark.teagasc.ie ) and Marge McCutcheon, West Virginia Department of Agriculture, USA (Feed Microscopy Division)
Contaminants in Food Processing. D. Kittleson, General Mills Technology East , USA
How to approach contaminant identification. M. Auty, Dairy Products Research Centre, Ireland
Identification of plant material. D.F. Wood, USDA, USA
To Be Announced. J. Makowski, Windsor and Associates, USA
Species identification of Animal Hair by Using Atomic Force Microscopy. C.W. Cruywagen, University of Stellenbosch, South Africa.
Quanitation of Total Fat and Fat Quality in Cheese and Dairy Products Using Membrane Separation Technology. V.C. Gordon, Safety Associates, Inc., USA
Detection and Differentiation of APRALAN, PAYLEAN, PULMOTIL and TYLAN in Animal Feeds using microscopy. P. Klink. Elanco Animal Health, a Division of Eli Lilly and Company, USA.
Additonal speakers to be announced.
Division Luncheon and round table (expert) discussion. Topic to be announced
Tuesday, May 7th - Afternoon Microbiology and Food Session Chairpersons: Judy Arnold and Ida Yates, USDA, ARS, Russell Research Center, USA
Prevention of Bacterial Fouling on Food Equipment Surfaces. J.W. Arnold, USDA, ARS, Russell Research Center, USA
Probiotics and Their Use in Food Animal Production. R. Droleskey, USDA, ARS, SPARC, USA
The Effect of High Pressure Steriliztion on Listeria Inoculated Seafood. K.R.S. Schneider and M.V.W. Wood, University of Florida, USA
Food Microstructure Investigations by Atomic Force Microscopy. J. Thornton, Digital Instruments/Veeco Metrology Group, USA
Controlling Growth of the Toxigenic Fungus, Fusarium Verticillioides. I. Yates and J. Arnold, Russell Research Center, ARS, USDA, USA
Division Members Meeting (immediately following the afternoon session)
Wednesday, May 8th- Morning Ingredients and Food Processing Session- Chairpersons: Diana Kittleson, General Mills Technology East, USA; and Bernhard Tauscher, Federal Research Center for Nutrition, Germany
Non-Invasive Quality Determination of Fruit and Vegetables: Application of a Multi-Wavelength NIR-Diode Laser Array. B. Tauscher, Federal Research Center for Nutrition, Germany
Characterisation of the Application of Novel Oil Structurants. E. Floeter, F. Gandolfo, and W. Hogervorst, Unilever Research Vlaardingen, The Netherlands
High Pressure Processing. E. Ting and E. Raghubeer, Flow International, USA
Microstructure of Rice Starch Isolates. D.F. Wood1, A.M.Ibanez_Carranza2, and C.F. Shoemaker2, 1USDA, ARS, WRRC, USA; 2University of California, USA
To be announced, D.W. Stanley, Department of Food Science, University of Guelph, Canada
To Be Announced. F. Escher, B. Conde-Petit, ETH, Switzerland
To Be Announced. M. Michel, Nestec Ltd., Nestle Research Center, Switzerland
To Be Announced. M. Salmenkallio-Marttila , VTT Biotechnology, Finland
To Be Announced. J. Boye, Agriculture and Agri-Food Canada, Canada.
Wednesday, May 8th - Afternoon New Methods and Techniques for Food Structure and Functionality Analysis SessionChairpersons: Kathy Groves, Leatherhead Food Research Association, England; and Maud Langton, SIK, Sweden
Quantifying Microstructures through Image Analysis. G.M.P. van Kempen1, M. van Ginkel2, C.L. Luengo Hendriks2, L.J. van Vliet2, and S. Singleton3, 1Unilever Research Vlaardingen, Netherlands; 2Delft University of Technology, The Netherlands; 3Unilever Research Colworth House, Great Britain
Cryo-TEM of Biopolymers in Comparision with Other TEM-techniques. M. Langton, A. Altskar, and A.-M Hermansson, SIK, Sweden
Freeze-substitution and low temperature embedding of dairy products for electron microscopy. A.K. Smith and H.D. Goff, Department of Food Science, University of Guelph, Canada
MicroRheology: preliminary results of structural behaviour of foods under deformation. M. Paques, Y. Nicolas, Wageningen Centre for Food Sciences/Unilever Vlaardingen, The Netherlands.
Recent Advances in our Understanding of the Relationship Between Crystallization Behavior, Microstructure and Rheological Properties of Fat Crystal Networks. A. Marangoni, University of Guelph, Canada
Spectroscopic Prediction of Rheological Properties in Grains. F. Meadows and F. Barton USDA, ARS, QARU, USA
Staining Techniques for Detection of Components in Fish Muscle. K. Hanneson Eggen and G. Enersen, Matforsk, Norway
Changes in plant tissue after pulsed electric field treatment. M. Fincan, P. Dejmek, Dept. of Food Engineering, Lund University, Sweden
Closure of Symposium
Posters
Relationships between Microstructure and Rheological Properties of Model Lipid Systems. B. Liang, Y. Shi, and R.W., Hartel Univ. of Wisconsin-Madison, USA
Minor Biomolecules from the Olive Drupe to Olive Oil: The Technology and the Well-being Effects. N. Uccella, CIRASAIA-Mediterranean Agrifood Research Centre, Calabria University, Italy
Formation and Physical Properties of ?-Fat Gel. I: Macroscopic and Microscopic Observations. K. Higaki1, Y. Sasakura1, I. Hachiya1, and K. Sato2, 1Meiji Seika Kaisha Ltd., Japan; 2Faculty of Applied Biological Science, Hiroshima University, Japan
Formation and Physical Properties of ?-Fat Gel. Ii: In situ Observation of Gel-Formation Processes. K. Higaki1, Y. Sasakura1, I. Hachiya1, S. Ueno2, and K. Sato2, 1Meiji Seika Kaisha Ltd., Japan; 2Faculty of Applied Biological Science, Hiroshima University, Japan
Formation and Physical Properties of ?-Fat Gel. III: Rheological Properties. K. Higaki1, T. Koyano1, I. Hachiya1, and K. Sato2, 1Meiji Seika Kaisha Ltd., Japan; 2Faculty of Applied Biological Science, Hiroshima University, Japan
Formation and Physical Properties of ?-Fat Gel. IV: Why and How? K. Sato1, K. Higaki2, T. Koyano2, and I. Hachiya2, 1Faculty of Applied Biological Science, Hiroshima University, Japan; 2Meiji Seika Kaisha Ltd., Japan
Exchange in Semi-Solid Triglyceride systems measured by NMR Spectroscopy: Effect of Partial Glycerides on Exchange Rates. P. Smith1, N. Haghshenas1, I. Furo2, and B. Bergenstahl3, 1YKI Institute for Surface Chemistry, Sweden; 2Royal Institute, Sweden; 3Lund University, Sweden.
Effect of Shear Rate on Fat Crystallization Kinetics. P.H. Rousset and V. Mooser, Nestle Research Center, Switzerland.
Utilizing Polarized Light Microscopy to Characterize the Effects of Tween60 on the Physical Properties of a Model Plastic Fat System. J.W. Litwinenko and A.G. Marangoni, University of Guelph, Canada.
AnnFook Yang may have gone to the experts, but do they know their own products?
The material known today as Sodium Thiosulphate (or sodium thiosulfate), with the composition Na2S2O3.5H2O was formerly known as sodium hyposulphite. As it was the principal ingredient in fixers, the conventional abbreviation for the fixing bath was "Hypo". The chemistry hasn't changed - just the name has been forgotten, but not by Kodak, who still manufacture (or at least, did last time we ordered it!) "Hypo-Clear", which is a rapid washing agent.
Kodak's current Rapid Fixer (which isn't listed on their Web site, but is referred to in the literature accompanying their current black-and-white photography products, and which we and others still buy in significant quantities) uses Ammonium Thiosulphate rather than the sodium salt. The same literature also specifies the use of Kodak Fixer, which presumably therefore is still available, and which I imagine is still a sodium thiosulphate (or "Hypo"!) based fixer, but I don't have any on hand, so can't be sure of that.
Interestingly, Ilford's web pages also do not mention their black-and-white fixers - only by going to the product specification pages can one find mention of the Ilford line of B&W chemicals - as asides in the processing recommendations. Is this some sort of conspiracy to render the market obsolete by denying users any information about the products, thus ensuring that the demand will wither away?
For our film - SO163 in our case - we use the exact sequence that the Kodak support person recommended, as we have for the past 25 years. For paper, on the rare occasions when we make photographic enlargements, we add the step of soaking in Hypo-Clear.
Tony Garratt-Reed
} I have never used Orbit bath nor Hypo. In fact the former is totally new } to me. I have heard of Hypo in the '60s. I was curious and went to the expert. } I phoned Kodak Scientific Support (800-225-5352) to find out whether } developing the 4489 film in D19 and fixing in Kodak Rapid Fixer is } adequate. The answer is "Yes" } What about Hypo? He asked, "Who makes it?" } He assured me that nothing else is needed after Rapid Fix. Just wash the } negs. in water will do. } } } } } } AnnFook Yang } EM Unit, } Eastern Cereal and Oilseed Research Centre, } Room 2091, Bldg. 20, } Central Experimental Farm, } Ottawa, Ontario } Canada K1A 0C6 } } Tel: 1-613-759-1638 } Fax: 1-613-759-1701 } } e-mail: yanga-at-em.agr.ca } } } } } "Paula Sicurello" {patpxs-at-gwumc.edu} 11/30/01 03:25PM } } } } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
** Anthony J. Garratt-Reed ** MIT Room # 13-1027 ** 77 Massachusetts Avenue ** Cambridge, MA 02139-4307 ** USA ** ** Phone: (+) 1-617-253-4622 ** Fax: (+) 1-617-258-6478 **
Catherine, a microtome devoted to polymers should have a cryo chamber since a lot of polymers are easier to section at sub-zero (C) temperatures. Definitely recommend a 35 deg knife. Other than that, just use common strategy for microtomy of biological samples (with some patience for trial/error temp setting). You can contact me off-line for our instrument info. Good luck,
Alice.
Alice Dohnalkova Battelle, PNNL Richland, WA (509)372-0692
-----Original Message----- } From: "Catherine.Derr-at-gastechnology.org"-at-sparc5.microscopy.com [mailto:"Catherine.Derr-at-gastechnology.org"-at-sparc5.microscopy.com] Sent: Monday, December 03, 2001 6:20 AM To: Microscopy-at-sparc5.microscopy.com
I looking at purchasing a microtome for sectioning polymers, primarily PE. Although I am familiar with microtomes used in biological studies, I have no experience in sectioning polymers. Has anyone sectioned polymers with repeated success? What features are desired for sectioning polymers? Is there a specific knife angle that works well?
KD Derr SEM/Polymer Technician Gas Technology Institute 1700 S Mount Prospect Rd Des Plaines, IL 60018 (847) 768-0505 (phone) (847) 768-0569 (fax) kd.derr-at-gastechnology.org
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Catherine Derr wrote: ====================================================== I looking at purchasing a microtome for sectioning polymers, primarily PE. Although I am familiar with microtomes used in biological studies, I have no experience in sectioning polymers. Has anyone sectioned polymers with repeated success? What features are desired for sectioning polymers? Is there a specific knife angle that works well? ====================================================== We have been sectioning polyethylene for over thirty years in our laboratory . If you are talking about thin sectioning polyethylene, unpigmented, then in many ways, the sectioning is not going to be greatly different from your biological samples.
There are several things that are going to be very important for you:
1] PE sectioning can not be done at room temperature, only cryo.
2] polyethylene is very soft, and the key is to do the sectioning with minimum distortion. That means diamond knives, and the smaller the angle the better. We usually are using a 35° knife angle.
3] polyethylene is either injection molded (into parts) or melt extruded (into film). The results you get from sectioning along the injection or extrusion direction might not necessarily be the same as when you section transverse to that section. So you want to give some thought as to which view would give you the most useful information considering your objectives and then it would be most important to always section all samples at the same angle relative to the machine direction. Otherwise, differences in section angle could be "interpreted" as differences between samples but such would be false interpretations.
4] pure unfilled polyethylene are normally pretty unremarkable by thin section TEM because there is nothing really to "see" or to give any contrast . Unless you were trying something exotic with the sections, such as negative staining of the lamellar or spherulytic structures, your main concern would be in the sectioning of the inorganic additive particles which in general would be much harder than the polyethylene. The presence of these additives would impart small damge points on the knife edge which would then show up as annoying striations in the final section (and image). Therefore you don't want to use your good (and expensive) life science knives for such sectioning, but a good materials science knife (which can be obtained through SPI or the other firms offering diamond knives.
5] We have found that when comparing microtomes from the two major ultramicrotome manufacturers, one can get comparable results using either system. Just remember that for this kind of work, a good cryo system is needed.
Chuck
=================================================== Charles A. Garber, Ph. D. Ph: 1-(610)-436-5400 President 1-(800)-2424-SPI SPI SUPPLIES FAX: 1-(610)-436-5755 PO BOX 656 e-mail: cgarber-at-2spi.com West Chester, PA 19381-0656 USA Cust. Service: spi2spi-at-2spi.com
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I would like to do 3D reconstructions out of my .avi or .tif series, is it possible to do so with the Confocal Assistant ? If not, what easy-to-handle software is available?
Thank you
Albert Cardona Genetics Department University of Barcelona Av. Diagonal, 645 08028 Barcelona, Spain
__________________________________________________ Do You Yahoo!? Buy the perfect holiday gifts at Yahoo! Shopping. http://shopping.yahoo.com
As a follow up to your posting on anodised componenets in vacuum - decorative anodising is often wiped with a light oil or polish, after dyeing, to give that nice shiny look.
Now that really isn't good for the vacuum!!!!
Regards, Ron
---------------------- Mr. R.C. Doole Department of Materials, University of Oxford. Parks Road, Oxford. OX1 3PH. UK. Phone +44 (0) 1865 273701 Fax +44 (0) 1865 283333 ron.doole-at-materials.ox.ac.uk
For crying into a big bucket. Under the onslaught I have no doubt that normal heavy duty anodized surface (like a handrail) are unsuitable for SEM mounts. } Most aluminium anodization that I have seen creates a dark } THICK oxide film (tens to hundreds of nm thick) and is insulating. (Nestor).
But I never suggested that the mounts were heavily anodized; on the contrary I stated that the coating on our mounts is very thin. Furthermore, I stated that the appearance of our mounts is identical to those from other suppliers. Recently, because of a lost shipment we had to buy some American-made mounts and I'm sure that no customer would have noted.
I am not an expert on anodizing either, but when many years ago I sent samples to our manufacturer, I was immediately advised - "they are anodized". So we had ours "anodized", afterall the samples had come from Chuck!
I find it amazing that, seemingly same listers believed that I would supply dull, thick anodized mounts which don't conduct and outgas catastrophically. My previous two communications, made it clear that that just wasn't so.
The issues may be: Is our supplier electropolishing, but calls that anodizing? Or how would in practice a very thin layer of anodizing differ from the naturally occurring oxide film? Or what is the end result of electro-polishing? Could this in fact add a thin anodized layer? Is a very thin anodized film shiny or dull?
I would have liked answers to those questions, which could have resolved the differences. At this point I know that the mounts are not just machined Al; they had a treatment and according to the manufacturer they are "anodized". There is of course the possibility that our manufacturer never applied any process. But why would he? The charge for "anodizing" is paltry. Thank you for your vigorous discussion. Cheers Jim Darley ProSciTech Microscopy PLUS PO Box 111, Thuringowa QLD 4817 Australia Ph +61 7 4774 0370 Fax:+61 7 4789 2313 service-at-proscitech.com Great microscopy catalogue, 500 Links, MSDS, User Notes ABN: 99 724 136 560 www.proscitech.com
On Tuesday, December 04, 2001 4:01 AM, Frederick Schamber [SMTP:schamber-at-aspexllc.com] wrote: } Jim, } I will be the first to admit that I am not an expert on either SEM stubs or } anodizing, but I have had very negative experience with the latter in vacuum } systems. I once designed some relatively small black-anodized parts into a } SEM and spent considerable time trying to find out why we had such bad } "outgassing" -- finally, someone wiser than me sanded off the anodizing and } the vacuum was fine. So I have, in effect, done the experiment you describe } -- ordinary machined aluminum parts are vastly superior to anodized aluminum } parts in terms of their vacuum properties in my experience (and I did some } followup experiments in a well-controlled apparatus designed specifically to } measure vacuum properties of materials and confirmed that a little bit of } anodizing is a very bad thing). It is not a question of the mere "roughness" } of the surface. Apparently the anodizing process creates very tiny } interstices which hold the dye, and this is what causes the problem -- or so } I have assumed. I suppose it could be the dye itself -- I never tried the } experiment on "clear anodized" parts. } When I look at catalog advertisements for aluminum SEM stubs, I always see } reference to various degress of polishing, and don't recall ever seeing } reference to anodizing. } From an electrical standpoint, I also really wonder how anodizing could work. } I know that anodizing must be avoided on electrical cabinetry because one } cannot establish reliable contacts (a different surface treatment process is } used on aluminum instead). I'm sceptical about the "thin coating" concept } since it is my understanding that it is precisely the insulating layer which } protects the surface from oxidation. Any amount of insulation on a SEM stub } would be a big problem. (Of course, the same thing can be said about the thin } oxide layer that naturally forms when aluminum is exposed to air.) But it is } my understanding that anodizing is a process which modifies the surface, not } a simple "coating" which can be "thin". } My negative opinions about anodizing for vacuum systems aren't just mine -- in } fact, I thought they were "common knowledge". For example, I refer you to the } very informative vacuum information site maintained by Roy Schmaus at the } University of Alberta } ~http://nyquist.ee.ualberta.ca/~schmaus/vacf/index.html } {http://nyquist.ee.ualberta.ca/schmaus/vacf/index.html} } Under Basics/an Introduction to Materials for use in Vacuum we find the } following statement: "Aluminum that will be exposed to vacuum should never be } anodized due to serious outgassing problems." Under "References" on the same } page he notes: "I recently had a call from someone who has used Anodized } Aluminum as an insulator down into the ultra high vacuum region. Admittedly } the pieces used were very small and initial outgassing was a problem but low } costs were a major advantage." [emphasis added] } So given my negative experience and the congruent remarks of others who work } in this field, I have long assumed that anodizing was something to avoid at } all costs in vacuum systems -- and I've assumed that applied to SEM stubs. Am } I wrong? } How do polished stubs stay so shiny? I've wondered the same. However, anodized } parts I have seen always have a kind of "matte" appearance, rather than a } high gloss in any case. } So, though it is entirely possible that I will learn something from this } discussion that I did not know previously (it would hardly be the first } time), my limited grasp of the subject still convinces me that SEM stubs } should NOT be anodized. But how do they retain their surface finish and } conductivity? Your response suggests that you manufacture SEM stubs and call } out an anodized surface -- did I read this correctly? Or are you purchasing } stubs which you assume are anodized? I really would be interested if someone } who is in the business of manufacturing these things could comment directly } to this -- without disclosing proprietary information of course. } "Charity" in view of the season notwithstanding, I consider this a matter of } considerable practical importance. If I am in error about this, I want to } know it, since a non-insulating, non-outgassing, but still protective } anodizing surface would be a very good thing. If I am correct, then others } reading this exchange should know that anodizing is something that should be } scrupulously avoided in vacuum systems (SEM and otherwise). In either case, } getting to the bottom of this will presumably be a good thing for everyone. } I'm prepared to learn from new facts, if someone can put them on the table. } Fred Schamber } ASPEX, LLC } } Jim at Proscitech wrote: } You are hoping in vain, commercial mounts are anodized, because: } 1 The layer is too thin to insulate even at low voltages. SEM have high volts } } (even specimen currents are many and not fractions of volts) and low currents. } } No problem. } 2 Otherwise the mounts would oxidise and I believe that too is not the best } conductor. } 3 Al too is porous, if you really care use polished stainless. } 4 Does it matter? It would in an ion pumped TEM, but in an SEM? } 5 All other suppliers do anodize. That is a better reason than you may think! } } 6 If we did not, people would buy other supplier's mounts because ours would } look "cheap" } Now, I have a question: How long have you and some other people been using } anodized mounts and not realised that the nice shiny finish is not a polish. } Have you never seen machine finished Al??? } If you really want to make a point, place a hundred commercial mounts into the } } bottom of the SEM chamber and then repeat that experiment with machine } finished } Al mounts. Record vacuua at various points and run the experiment three times. } } Report the results. I would be interested to learn if there is any difference. } } Those hundred plain Al mounts made in a machine shop would be a trifle } expensive (you could acid strip the anodizing), but cheaper than most } experiments. } Christmas is coming, so lets be charitable: anodized mounts are a good deal } and } they are very suitable for SEM work. } Cheers } Jim Darley } ProSciTech Microscopy PLUS } PO Box 111, Thuringowa QLD 4817 Australia } Ph +61 7 4774 0370 Fax:+61 7 4789 2313 service-at-proscitech.com } Great microscopy catalogue, 500 Links, MSDS, User Notes } ABN: 99 724 136 560 www.proscitech.com } On Monday, December 03, 2001 12:14 PM, Frederick Schamber } [SMTP:schamber-at-aspexllc.com] wrote: } } I would certainly hope that SEM stubs are NOT anodized. Not only does } } anodizing } } create an insulating surface, but it also creates a surface with very poor } } vacuum } } properties -- anodized parts will pump down slowly due to the gas trapped in } } } } the } } porosity. } } } } Fred Schamber } } ASPEX, LLC } } } } Jim at Proscitech wrote: } } } } } ------------------------------------------------------------------------ } } } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } } } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } } } On-Line Help {http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html} } } } } } } -----------------------------------------------------------------------. } } } } } } I'm certain that every mount sold by ProSciTech is anodized, and by their } } } } } } very } } } appearance, all other such commercially sold mounts I have seen are } } } anodized } } } too. True the anodized film is very thin. } } } Cheers } } } Jim Darley } } } ProSciTech Microscopy PLUS } } } PO Box 111, Thuringowa QLD 4817 Australia } } } Ph +61 7 4774 0370 Fax:+61 7 4789 2313 service-at-proscitech.com } } } Great microscopy catalogue, 500 Links, MSDS, User Notes } } } ABN: 99 724 136 560 www.proscitech.com } } } } } } On Saturday, December 01, 2001 9:07 AM, Darrell Miles } } } [SMTP:milesd-at-US.ibm.com] } } } wrote: } } } } ------------------------------------------------------------------------ } } } } } } } } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } } } } } } } } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } } } } } } } } On-Line Help } } } } {http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html} } } } } -----------------------------------------------------------------------. } } } } } } } } } } } } } } } } Anodizing of aluminum can be done in many colors, as } } } } well as a clear coating. I would not expect SEM stubs to be } } } } anodized, as the aluminum oxide coating which forms is an } } } } insulator. This would inhibit the removal of the electron } } } } charge from the sample. The native oxide film is no where } } } } near the thickness of the usual anodized film, and can easily } } } } be broken. The thickness of the anodized film can be } } } } controlled, but it is still an effective insulator. I am fairly } } } } certain that none of the stubs I have ever used were anodized. } } } } } } } } Regards, } } } } Darrell
The consensus on my question was HUH? Most of the EM world has used a hypo clearing agent after the fixer step to reduce the washing time. Though I did get a reply stating that is was used originally to reduce the time in fixer and it was supposed to make for better archival properties.
I will be returning to the tried and true method as soon as it gets here.
Thanks to all who replied.
Paula :-)
Paula Sicurello George Washington Univ. Medical Center Dept. of Pathology, Ross Hall rm 505 Electron Microscope Lab 2300 Eye St. Washington, DC 20037 202-994-2930 phone 202-994-2518 fax
Just to clear up a couple of statements someone made. There is no such thing as a "clear" anodic film. And dies are not used to give anodic films colour ..The colour comes from metals in the anodic layer. Thickness of the layer is also a factor.
Paul D. Nolan Electron Optics
Alcan International Limited Kingston Research and Development Centre P.O.Box 8400, 945 Princess Street Kingston, Ontario K7L 5L9
The native oxide thickness of aluminum metal, depending upon processing, is typically on the order of 30 to 50 angstroms. You can measure this thickness very easily by making a simple XPS measurement of the Al2p core level.
I'm looking for a double sided adhesive to stick samples (aluminum) onto glass slides. I want to be able to remove them with relative ease and replace them for storage. Conductivity is not an issue At present i am using those little double sided sticky press down adhesives used for SEM stubs ..they are a little to sticky for my liking.
Any suggestions?
Paul D. Nolan Electron Optics
Alcan International Limited Kingston Research and Development Centre P.O.Box 8400, 945 Princess Street Kingston, Ontario K7L 5L9
} With any instrument purchase the best thing to do is go to the } manufacturers, or better yet have them come to you, and see how the } instrument works on your samples. I have extensive experience sectioning } PE and I have always used Reichert-Jung, now Lieca, ultramicrotomes. That } does not mean others would not do the job. The main thing is to get a } system that works well when cryo-ultramicrotoming. As stated in another } response you may well have to cryotome your samples and if you are buying } for polymer work you definitely want to get a system that will work at } both room temp and cryo conditions. How to section PE can differ } depending on the type of PE, high density or low density. If you have } HDPE then you can often pre-stain with Chlorosulfonic Acid and room temp } microtome. Otherwise you may have to stain with RuO4 before or after } cryomicrotoming. There are many good references on these } techniques. Good luck on your purchase.
} I looking at purchasing a microtome for sectioning polymers, primarily } PE. Although I am familiar with microtomes used in biological studies, I } have } no experience in sectioning polymers. Has anyone sectioned polymers with } repeated success? What features are desired for sectioning polymers? Is } there a specific knife angle that works well? } } KD Derr } SEM/Polymer Technician } Gas Technology Institute } 1700 S Mount Prospect Rd } Des Plaines, IL 60018 } (847) 768-0505 (phone) } (847) 768-0569 (fax) } kd.derr-at-gastechnology.org
Stephen McCartney Research Associate 2108 Hahn Hall Materials Institute Virginia Tech Blacksburg, VA 24061-0344 USA
Being a Plant Pathologist, the best I can think of is the story of Pierce's disease of grapes, which was of unknown etiology for a long time. Forgive me for not seeking details from the literature.
At one time it was proposed to be caused by a virus. Extensive light microscope work missed the true cause- a bacterium. After elucidation of the pathogen, I am told that upon review of work previously done, the bacterium WAS there to be seen, but was missed.
Upon a similar vein, MLO's in plants were not recognized in TEM work until a human or animal pathologist saw micrographs of MLO's in plant tissue, and was readily able to say what they were.
Anecdotal, but food for thought.
Lesson? I better keep my eyes and my mind open.
Maureen Petersen Dept. Plant Pathology University of Florida
Dear Listers, Given that my curiosity is up per the plating/no plating of the stubs, my posting is geared more towards the actual reusing of stubs. For the past eight years I have been subjecting a set of 50 or so stubs to a sand blasting treatment. You may question the feasibility of a sandblaster BUT what is important is the media used to blast with. glass beads in the range of 170-325 mesh are used to effectively remove residue, glue, tape, and any material that resides on the stub. This particular media results in no residue and no tolerance change, although a pure water treatment and ultrasonic wash are utilized. I have had no trouble at all even after this amount of time.
Robert Fowler Quality Assurance Technician (Failure Analysis) TDK Components USA, Inc. Multilayer Ceramic Capacitor Division 1 TDK Boulevard Peachtree City GA 30269-2051 Telephone: (770) 631-0410 Ext.315 Fax: (770) 487-1460 email: rfowler-at-tdktca.com www.tdk.com
I embed the hair in epoxy after the usual fixation and dehydration steps. Then section with a glass knife, mount on a slide, and stain with toluidene blue. Joyce Craig Chicago State University
You are right about an anodized aluminum finish. It is an excellent insulator, not at all the type of finish you want on an SEM specimen mount, as conductivity is critical. I think it may also create vacuum problems.
The mounts (stubs) we manufacture are machined on very high speed turning equipment from high grade aluminum bar stock. After machining, we put them through a rigorous part cleaning process using special cleaning solutions. Typical chemical based solutions tend to leave a film on the mounts that both insulates and degrades vacuum. Event our turning equipment uses a special, non-petro based cutting lubricant to avoid the potential for any contamination. Each mount is then carefully inspected and wiped down to ensure that they are completely clean and dry, then stored in air tight packing material.
Because our machines operate at such high speeds, our process eliminates the need for polishing. However, mounts that are made on more conventional lathes or machines may require a final polishing to achieve the same results.
I hope this helps.
Best regards, Michael R. Nesta General Manager Energy Beam Sciences, Inc. Agawam, MA USA Tel: (413) 786-9322 "Adding Brilliance to Your Vision"
-----Original Message----- } From: zaluzec-at-sparc5.microscopy.com [mailto:zaluzec-at-sparc5.microscopy.com] Sent: Monday, December 03, 2001 9:32 AM To: Microscopy-at-sparc5.microscopy.com
As I recall from my metallurgy
To "Anodize" is to subject a metal to an electrolytic action as the anode of a cell in order to coat/deposit a protective or decorative film.
Most aluminium anodization that I have seen creates a dark THICK oxide film (tens to hundreds of nm thick) and is insulating.
I've never seen this on an aluminium SEM stub. Certainly many I've used are electropolished and some (the ones we make here in our machine shop ) are simply milled and mechanically polished. All will at a minimum have a native oxide. All are conductive, and yes (Jim) I've seen polished (electrochemical, mechanical) as well as all ranges of "machine" finished products. These are NOT anodized, they are all simply oxidized by leaving them sit in air. The native oxide which forms is a few tens of angstroms thick and is stable, by definition this is not anodization. I have never heard of anyone calling this process "anodization" should that be what you are referring to.
So... now I'm curious and I would request that the various suppliers who like reply to this list to fill us all in on what you do.
1.) How many of you anodize your stubs (ie. coat), vs electropolish, vs mechanically polish. 2.) If you intentionally anodize, (ie. deposit/coat) your stub with an electrodeposited layer how thick is your film, and what do you anodize it with. 3.) It might also help to define the "anodization" process (if you do this) so that we are all understand what each of you mean in the context of how you make the stubs we purchase.
we inadvertantly ordered several thousand 4x5 inch glassine envelopes (for EM negatives). As we are not using this size and I would hate to waste them, anybody could have them for free. I am at the University of Chicago. Please contact me offline.
Paul Is there a distinction between an anodic film and an anodised film??
Organic dyes are in fact widely used to colour anodized aluminium, though I am prepared to concede that I am not up to date with techniques for anodizing, and may have missed recent innovations involving metal-doping of the oxide film. The aluminium oxide film formed on anodized aluminium at first has a frosted appearance, which is presumably caused by light scattering from multiple voids and micro-rough surfaces. The film is rendered more translucent by various post-anodizing treatments, following dyeing if desired. But once this treatment is carried out, the film is clear - i.e. you can see right through to the base metal, aluminium oxide being one of nature's clear, light-transmitting materials. Most people have experienced lightfastness problems in dyed anodized aluminium products, a syndrome which I am not aware occurs in metal-doped alumina such as ruby. I have seen the anodizing process being carried out, including dyeing with organic dyes, without any other metal than aluminium in sight. Was I dreaming this?
Chris
} Just to clear up a couple of statements someone made. } There is no such thing as a "clear" anodic film. } And dies are not used to give anodic films colour ..The colour comes from } metals in the anodic layer. Thickness of the layer is also a factor. } } Paul D. Nolan } Electron Optics } } Alcan International Limited } Kingston Research and Development Centre } P.O.Box 8400, 945 Princess Street } Kingston, Ontario K7L 5L9 } } Tel: (613) 541-2066 } Fax: (613) 541-2134 } paul.nolan-at-alcan.com } }
Robert, I also bead-blast stubs. Works very well as long as you're not looking for a smooth surface, then you have to grind and polish afterwards, but the bead blasting DOES clean that top surface in a hurry. On Al I usually only blast at 35psi to keep the erosion down.
I have several pieces of Al that have a lot 1/8" holes drilled in them. Load'em up with stubs and blast away! It's fast, it's fun and reasonably ecologically sound. Follow with a BRIEF ultrasonic bath in JOY, rinse with tap, DI or distilled water, depending on how particular you are, and dry. Alconox and some of the other heavy-duty lab cleaners have a pH that is far too high for Al, although they work great on glass.
Ken Converse owner Quality Images third party SEM service Delta, PA
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } } Dear Listers, } Given that my curiosity is up per the plating/no plating of the stubs, my } posting is geared more towards the actual reusing of stubs. For the past } eight years I have been subjecting a set of 50 or so stubs to a sand } blasting treatment. You may question the feasibility of a sandblaster BUT } what is important is the media used to blast with. glass beads in the range } of 170-325 mesh are used to effectively remove residue, glue, tape, and any } material that resides on the stub. This particular media results in no } residue and no tolerance change, although a pure water treatment and } ultrasonic wash are utilized. I have had no trouble at all even after this } amount of time. } } Robert Fowler } Quality Assurance Technician (Failure Analysis) } TDK Components USA, Inc. } Multilayer Ceramic Capacitor Division } 1 TDK Boulevard } Peachtree City GA 30269-2051 } Telephone: (770) 631-0410 Ext.315 } Fax: (770) 487-1460 } email: rfowler-at-tdktca.com } www.tdk.com } } } }
Michael R. Nesta wrote: =============================================================== You are right about an anodized aluminum finish. It is an excellent insulator, not at all the type of finish you want on an SEM specimen mount, as conductivity is critical. I think it may also create vacuum problems.
The mounts (stubs) we manufacture are machined on very high speed turning equipment from high grade aluminum bar stock. After machining, we put them through a rigorous part cleaning process using special cleaning solutions. Typical chemical based solutions tend to leave a film on the mounts that both insulates and degrades vacuum. Event our turning equipment uses a special, non-petro based cutting lubricant to avoid the potential for any contamination. Each mount is then carefully inspected and wiped down to ensure that they are completely clean and dry, then stored in air tight packing material.
Because our machines operate at such high speeds, our process eliminates the need for polishing. However, mounts that are made on more conventional lathes or machines may require a final polishing to achieve the same results
"Paul.Nolan-at-alcan.com"-at-sparc5.microscopy.com wrote: } Just to clear up a couple of statements someone made. } There is no such thing as a "clear" anodic film. } And dies are not used to give anodic films colour ..The colour comes from } metals in the anodic layer. Thickness of the layer is also a factor. } Paul D. Nolan
The anodizing process for aluminium indeed does require a dye. There are plenty of companies selling the dyes etc.. http://www.caswellplating.com/frames.asp?bottom=/anodizedye.htm http://www.plating-supplies.com/Anodizing.html http://www.davistl.com/services/anodizing_plating.htm
Some pages actually showing the process: http://www.focuser.com/atm/anodize/anodize.html http://hem.passagen.se/ballista/anod_eng.html
And one does get the "clear" anodization by using same process, but not using dye.
There are as well other methods for getting, for example titanium, colourfull surface films. These are used in jewelry etc. and some do refer to these as anoziding (anodic polarization). However, the aluminium anodizing does as common term refer to the dye process described above.
Not sure if this one fits the bill but it is a similar one to the grape disease story by Maureen Petersen.
The one I mean is the discovery/description of Helicobacter pylori in human gastric biopsies in the early 80's (when it was given the name Campylobacter pylori). It had been there all of the time but had been disregarded as 'stuff'.
I seem to recall a similar story regarding the finding of Actinomyces in cervical smear material.
We tend to see what we expect might possibly be there and consciously or unconsciously ignore the rest as 'noise' - perhaps a natural action but also potentially dangerous.
I have not looked up the original references either but a search on www.google.com will provide much information.
Med vänliga hälsningar/With best wishes
Gareth
"Close your eyes and look. What you saw at first is there no more; and what you will see next has not yet come to life" Leonardo da Vinci (1452-1519).
Gareth Morgan MPhil MSc FIBMS, Institutionen för Mikrobiologi, Patologi och Immunologi(IMPI), H5, Karolinska Institutet, Dept of Biomedical Laboratory Science, Lindhagensgatan 92, Box 12773, S 112 96, Stockholm Sweden
We usually tend to avoid issues between suppliers which are controversial, but based on our long experience in the business in this area, we shall. Ladd, being the oldest EM supplier and first company to provide commercail SEM mounts, has never anodized our mounts. We continue to machine polish them as we have done thru the years. Based on our long history we feel that anodizing would be ineffective at best and perhaps just increase cost unnecessarily.
John Arnott
Disclainer: Ladd Research sells EM supplies, including SEM mounts. --
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zaluzec-at-sparc5.microscopy.com wrote: } } ------------------------------------------------------------------------} The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------.} } As I recall from my metallurgy } } To "Anodize" is to subject a metal to an electrolytic action as the } anode of a cell in order to coat/deposit a protective or decorative film. } } Most aluminium anodization that I have seen creates a dark } THICK oxide film (tens to hundreds of nm thick) and is insulating. } } I've never seen this on an aluminium SEM stub. Certainly many I've used are } electropolished and some (the ones we make here in our machine shop ) } are simply milled and mechanically polished. All will at a minimum } have a native oxide. } All are conductive, and yes (Jim) I've seen polished } (electrochemical, mechanical) as } well as all ranges of "machine" finished products. These are NOT anodized, they } are all simply oxidized by leaving them sit in air. The native oxide } which forms } is a few tens of angstroms thick and is stable, by definition this is not } anodization. I have never heard of anyone calling this process "anodization" } should that be what you are referring to. } } So... now I'm curious and I would request that the various suppliers } who like reply } to this list to fill us all in on what you do. } } 1.) How many of you anodize your stubs (ie. coat), vs electropolish, } vs mechanically polish. } 2.) If you intentionally anodize, (ie. deposit/coat) your stub with } an electrodeposited layer } how thick is your film, and what do you anodize it with. } 3.) It might also help to define the "anodization" process (if you do } this) so that we are all } understand what each of you mean in the context of how you make the } stubs we purchase. } } Nestor } Your Friendly Neighborhood SysOp.
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Listers, I know this topic has come up previously but many of the responses have gone directly to the inquirer rather than to the list. I am looking for information about video rate CCD camera for TEM below $50,000 in cost. The intended use for the camera is teaching and assisting investigators in viewing samples in a service lab situation. It is not meant for capture of high quality images but capture of lower quality images "for the record" would be helpful. I am already in touch with Gatan concerning such cameras so would like to hear about other options. I would appreciate hearing from users regarding their recommendations and experiences but do not mind hearing directly from venders. Thank you, Debby
Debby Sherman Phone: 765-494-6666 Life Science Microscopy Facility FAX: 765-494-5896 Purdue University E-mail: dsherman-at-purdue.edu S-052 Whistler Building West Lafayette, IN 47907
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Ken, If a smoother finish is in order then I also use a more aggressive media (60 - 120 mesh). This media gives a much smoother "glossy" finish but I personally have never had a reason to have the surface that smooth.
Robert Fowler Quality Assurance Technician (Failure Analysis) TDK Components USA, Inc. Multilayer Ceramic Capacitor Division 1 TDK Boulevard Peachtree City GA 30269-2051 Telephone: (770) 631-0410 Ext.315 Fax: (770) 487-1460 email: rfowler-at-tdktca.com www.tdk.com
Ken Converse {qualityimages-at-n To: "robert.fowler-at-tdktca.com" etrax.net} -at-sparc5.microscopy.com, "MSA, listserver" {Microscopy-at-sparc5.microscopy.com} 12/04/2001 05:34 cc: PM Subject: Re: Aluminum Stubs
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Robert, I also bead-blast stubs. Works very well as long as you're not looking for a smooth surface, then you have to grind and polish afterwards, but the bead blasting DOES clean that top surface in a hurry. On Al I usually only blast at 35psi to keep the erosion down.
I have several pieces of Al that have a lot 1/8" holes drilled in them. Load'em up with stubs and blast away! It's fast, it's fun and reasonably ecologically sound. Follow with a BRIEF ultrasonic bath in JOY, rinse with tap, DI or distilled water, depending on how particular you are, and dry. Alconox and some of the other heavy-duty lab cleaners have a pH that is far too high for Al, although they work great on glass.
Ken Converse owner Quality Images third party SEM service Delta, PA
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } } Dear Listers, } Given that my curiosity is up per the plating/no plating of the stubs, my } posting is geared more towards the actual reusing of stubs. For the past } eight years I have been subjecting a set of 50 or so stubs to a sand } blasting treatment. You may question the feasibility of a sandblaster BUT } what is important is the media used to blast with. glass beads in the range } of 170-325 mesh are used to effectively remove residue, glue, tape, and any } material that resides on the stub. This particular media results in no } residue and no tolerance change, although a pure water treatment and } ultrasonic wash are utilized. I have had no trouble at all even after this } amount of time. } } Robert Fowler } Quality Assurance Technician (Failure Analysis) } TDK Components USA, Inc. } Multilayer Ceramic Capacitor Division } 1 TDK Boulevard } Peachtree City GA 30269-2051 } Telephone: (770) 631-0410 Ext.315 } Fax: (770) 487-1460 } email: rfowler-at-tdktca.com } www.tdk.com } } } }
One of my customers needs to remove AFM cantilevers from SEM stubs after examination without breaking them. Standard SEM adhesives are too sticky for him too.
We cut a square from the adhesive section of a Post-It note, and used double-stick tape to attach it to the stub with the Post-It adhesive facing up. It is sticky enough to hold his small samples in place - if your samples are not too large or heavy, it might be worth a try.
The Department of Energy has issued a solicitation for Small Business Innovative Research (SBIR) proposals related to electron beam instrumentation. This is a great opportunity for small businesses to apply for research funding to help develop their creative ideas for instrumentation and methods that can help advance the field. This is the second year the solicitation includes electron beam instrumentation and it is hoped that a strong set of proposals will be received.
The web site detailing the solicitation is: http://sbir.er.doe.gov/sbir/Solicitations/FY%202002/BES.htm#T9 (This will take you directly to the portion dealing with electron beam instrumentation.)
Electron beam instrumentation is included in technical topic 9, "NEUTRON AND ELECTRON BEAM INSTRUMENTATION." Part b covers Electron Beam Microcharacterization Facilities.
In short, grant applications are sought:
-to develop stages and holders with new capabilities for in situ experiments in the transmission electron microscope.
-to develop electron sources for scanning transmission electron microscopy with brightness on the order 109 Amp/cm2/steradian or higher.
-for systems for automated data collection and processing.
-for improved x-ray and electron detectors.
The closing date is Jan 15, 2002 but please be sure to check the web site to verify this!!
Please distribute this information to your colleagues that may have an interest in this area and encourage them to think creatively. If there are any questions, please contact the SBIR program office or you may contact me off-line.
Best regards, Dean
--------------------------- Dean J. Miller Materials Science Division Argonne National Laboratory Argonne, IL 60439
We use cleaved edge specimens of III-V multilayers. We can measure layer thicknesses in-house to a good accuracy (~0.1%) using high resolution X-ray diffraction, whereas the mag-i-cal is (I believe) only guaranteed to +/- 2%. Measurement errors from TEM negatives puts the error in calibration up to about 0.5%. The thin area on the samples is miniscule and they are very robust. A drawback is that you need to be able to tilt the sample to 45 degrees. As discussed some time ago on this listserver, you need to be careful to eliminate lens hysteresis effects if you want to make your measurements accurate.
Cheers,
Richard Beanland Marconi Caswell Ltd. Towcester, Northants, NN12 8EQ UK
e-mail richard.beanland-at-marconi.com
-----Original Message----- } From: Garber, Charles A. [mailto:cgarber-at-2spi.com] Sent: 03 December 2001 18:53 To: MICROSCOPY BB
-- [ From: Garber, Charles A. * EMC.Ver #3.1 ] --
John M. Basgen wrote: =============================================================== We have been using carbon grating replicas for calibrating the magnification of our TEM images for many years. We are in the process of revising our imaging and morphometry protocols. I am not happy with the precision and longevity of the carbon grating replicas. Are there more precise and/or stronger standards for TEM magnification calibration? The final magnifications of our images range from 3,000 -20,000 X. ================================================================ Have you seen the MAG*I*CAL(tm) TEM Calibration Specimen as described on the SPI website, page URL http://www.2spi.com/catalog/standards/magical.html
It seems to get around most of the problems associated with the carbon grating replicas and although nothing is forever, it is quite robust in comparison and should last quite a long time.
Chuck
=================================================== Charles A. Garber, Ph. D. Ph: 1-(610)-436-5400 President 1-(800)-2424-SPI SPI SUPPLIES FAX: 1-(610)-436-5755 PO BOX 656 e-mail: cgarber-at-2spi.com West Chester, PA 19381-0656 USA Cust. Service: spi2spi-at-2spi.com
Look for us! ############################ WWW: http://www.2spi.com ############################ ==================================================
Anodizing. Seems like everyone knows what it is, until they compare notes!
The furor drove me to crack a wonderful older textbook, Thin Film Processes, edited by John L. Vossen and Werner Kern, Academic Press 1978.
} From my reading the reason for the confusion is clear: there really are a lot of ways to anodize aluminum, some of which result in a clear coating, some colored, some porous, some hard. The most common and least expensive method is the sulfuric acid process with follow-up dying described so excellently on the web pages Kristian Ukkonen refers us to.
For anyone who is interested, here are some excerpts on various ways of anodizing aluminum, from the chapter by Frederick Lowenheim on "Deposition of Inorganic Films from Solution".
"Although H2SO4 is the most common anodizing electrolyte, many others are in use. For special effects or attainment of special properties, chromic acid anodic coatings are opaque, limited to about 10 um in thickness...
"Phosphoric acid anodizing has been used as a basis for plating on Al, though it has been largely superseded by the zincate and other processes.
"Oxalic acid coatings are yellow, and somewhat harder than conventional H2SO4 coatings. Mixtures of oxalic and sulfuric acid produce hard coatings, competing with low-temperature H2SO4 processes.
"Sulfonated organic acids, combined with H2SO4, produce so-called 'integrally colored' coatings on specific alloys. Various shades are used in architectural applications...
"Boric acid electrolytes, often with additions of borax, produce thin barrier oxide coatings used for electrical capacitors.
"Many anodic coatings on Al can be colored, either with organic dyes or mineral pigments. Postanodic treatments, especially that known as sealing, are important in determining the final properties of the coating..."
Libby Shaw
} From: Kristian Ukkonen {kristian.ukkonen-at-iki.fi} } } } "Paul.Nolan-at-alcan.com"-at-sparc5.microscopy.com wrote: } } Just to clear up a couple of statements someone made. } } There is no such thing as a "clear" anodic film. } } And dies are not used to give anodic films colour ..The colour comes from } } metals in the anodic layer. Thickness of the layer is also a factor. } } Paul D. Nolan } } The anodizing process for aluminium indeed does require a dye. } There are plenty of companies selling the dyes etc.. } http://www.caswellplating.com/frames.asp?bottom=/anodizedye.htm } http://www.plating-supplies.com/Anodizing.html } http://www.davistl.com/services/anodizing_plating.htm } } Some pages actually showing the process: } http://www.focuser.com/atm/anodize/anodize.html } http://hem.passagen.se/ballista/anod_eng.html } } And one does get the "clear" anodization by using same } process, but not using dye. } } There are as well other methods for getting, for example } titanium, colourfull surface films. These are used in } jewelry etc. and some do refer to these as anoziding } (anodic polarization). However, the aluminium anodizing } does as common term refer to the dye process described } above. } } Kristian Ukkonen. } *************************************************************** Elisabeth L. Shaw, Facility Coordinator Surface and Spectroscopy Labs Analytical Shared Experimental Facilities MIT Center for Materials Science and Engineering
Address: MIT Room 13-4149 Tel: 617-253-5045 77 Massachusetts Ave. Email: elshaw-at-mit.edu Cambridge, MA 02139 Fax: 617-258-6478 http://web.mit.edu/cmse/www/ ***************************************************************
This query is directed specifically at users of the Hitachi S4700 FESEM, but may also apply more widely to users of FESEM's.
We get a curious result (to me) when flashing the tip. We were advised to flash until the emission current reading read about 20uA on the "le" meter. The flash intensity adjustment behind the scope was initially set to accomplish this in one or two flashes when flashing at an intensity of "2" in the Setup-Column menu.
That is what happened for quite some time, however for a while now flashing has resulted in values between 7-12 on the "le" meter. The initial flash briefly degrades the vacuum at the gun as expected as contamination is driven off, but subsequent flashes do not, also as expected. However, subsequent flashes usually LOWER the "le" meter value, rather than raise it toward our goal of 20. This is the really puzzling part to me. Originally, the value increased with each flash, and if an excessive number of flashes were required, we would adjust the intensity pot in the rear of the scope.
We normally run the scope at an emission of 10uA, with kV's of 1.0-10.0. All vacuum readings are normal, and the scope performs beautifully in terms of resolution and brightness.
My questions are:
1) Why is the "le" value decreasing with multiple flashes?
2) How dangerous are multiple flashes to the tip?
3) Does the condition described above indicate any problem with the tip and/or scope?
4) Is flashing actually accomplishing anything if the vacuum gauge shows no contamination being driven off?
5) Is it safe to keep turning up the intensity pot on the rear of the scope? (Something tells me no.)
6) Do I simply not understand what's going on? (Something tells me yes.)
Thanks in advance!
Puzzled in Missouri, Randy
Randy Tindall EM Specialist Electron Microscopy Core Facility W122 Veterinary Medicine University of Missouri Columbia, MO 65211 Tel: (573) 882-8304 Fax: (573) 884-5414 Email: tindallr-at-missouri.edu Web: http://www.biotech.missouri.edu/emc/
FYI: ctfexplorer has been updated and it is still free for all. New features/improvements: - extended microscope list - "Euro-bug" removed (problem with Windows locales which use a comma instead of a point for a decimal separator).
To the best of my knowledge, the software does not have any nasty bugs. It is tested under Windows 95/98/NT4/2000.
Please give it a try. Please DO direct your suggestions and comments to sidorov-at-yahoo.com I hope you'll find the software useful.
Here is the link: http://clik.to/ctfexplorer (always use this link. it will direct you to the right location). Direct link: http://www.maxsidorov.com/ctfexplorer
Enjoy, __________________________________ Max Sidorov, Ph.D. sidorov-at-yahoo.com
----------Additional Info---------- ctfExplorer is a highly interactive program which calculates/displays the contrast transfer function of TEMs. I know that there are similar programs floating around but ctfexplorer does not only 1d but also 2d calculations/display with 2-fold and 3-fold astigmatism imposed. There are other unique features to it. All parameters (defocus, voltage, Cs, etc) can be changed interactively.
Features - Calculates 1-Dimensional CTF - Calculates 2-Dimensional CTF - Calculates Defocus Map - Calculates point-to-point resolution, Lichte defocus and info limit - Shows the effects of 2-Fold and 3-Fold astigmatism - Allows to change Defocus, 2-Fold and 3-Fold astigmatism in real time - Shows what happens to 1D CTF in different directions when there's astigmatism - Displays the damping envelopes - Allows to select a microscope from a list of microscopes - Allows to create a custom microscope - Allows to change HT, Cs, Cc, Energy Spread, Convergence for any microscope - 2 modes of operation: CTF Explorer (to see everything) and CTF Plotter - Compares 2 microscopes or 2 settings for 1 microscope - Saves 1D CTF, 2D CTF and "Defocus Map" as bitmaps or metafiles - Exports 1D plots to tab-delimited text format
What you are looking for sounds like our product numbers 60550, Double Coated Aluminum tape. Please contatc me or check our website for more details.
John Arnott
Disclaimer: Ladd Reserch sells EM supplies. This product may be available from other vendors. --
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Paul.Nolan-at-alcan.com-at-sparc5.microscopy.com wrote: } } ------------------------------------------------------------------------} The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------.} } Hello } } I'm looking for a double sided adhesive to stick samples (aluminum) onto } glass slides. } I want to be able to remove them with relative ease and replace them for } storage. } Conductivity is not an issue } At present i am using those little double sided sticky press down adhesives } used for SEM stubs ..they are a little to sticky for my liking. } } Any suggestions? } } Paul D. Nolan } Electron Optics } } Alcan International Limited } Kingston Research and Development Centre } P.O.Box 8400, 945 Princess Street } Kingston, Ontario K7L 5L9 } } Tel: (613) 541-2066 } Fax: (613) 541-2134 } paul.nolan-at-alcan.com
Hello, I have another vacuum problem with our Electronscan E3 ESEM after swapping out a failing rotary pump. The vacuum was working fine and then after being in standby for a couple days, we went into wet mode and had a vacuum failure with the message: "Error cannot Determine state" on the console. Resetting gives the same message. Power cycling the console gives an "E2 can't pump column error", followed by the cannot determine state message.
Powering everything off and restarting, it seems the diffusion pumps won't start up now. Everything was working fine, but now I think there is a problem with the vacuum control unit or a sensor. Is there a way of resetting the VCU, or some other troubleshooting I can do? Thanks for any advice. Gordon
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ Gordon Ante Vrdoljak Electron Microscope Lab ICQ 23243541 http://nature.berkeley.edu/~gvrdolja 26 Giannini Hall gvrdolja-at-nature.berkeley.edu UC Berkeley phone (510) 642-2085 Berkeley CA 94720-3330 fax (510) 643-6207 cell (510) 290-6793
Thanks for the comment, Mike. Just a bad wording from my side. MAx
-----Original Message----- } From: Michael O'Keefe [mailto:MAOKeefe-at-lbl.gov] Sent: Wednesday, December 05, 2001 10:56 AM Cc: sidorov-at-yahoo.com
Sorry about the subject name, it is a bit misleading. In using a Leica SP2 confocal, I have noticed that it is possible to see the cover slip and slide. Why/how is this possible? The setup is essentially this: a coverslip is placed on a slide, which is then placed on the stage (there is nothing between them, except of course for miscellaneous small dust particles and air). The slide is then scanned with light from a HeNe laser (633nm). When the light detection (wavelengths directed to the PMT's) is set to include 633nm (i.e. 610-650nm), the signal is of course very bright. I am assuming that this is due to reflection. What I am confused about is that if the light detection doesn't include 633nm (sampling from 660-710nm), there is still signal present, and it is in the same pattern as is seen when looking at the reflected light. It is important to note that this pattern is connected to the coverslip and slide somehow, as moving the stage will cause a corresponding change in the image produced by the system. I realize that I may be missing something fairly obvious, but any help would be greatly appreciated.
Thanks, Russell
-- Confocal Imaging Facility Technician Tufts Medical School 136 Harrison Ave. Boston, MA 02111 Tel. (617) 636-3795
Leslie has a great idea. I've used it myself for wafer pieces. Another thing that I've used is the double-sided carbon tape, but have reduced the surface adhesion by touching it repeatedly with my fingers or something else that is strong enough to be pried off without damage. This makes the tape tacky, but without the death grip is has when it's new.
Leslie Eibest wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } Paul; } } One of my customers needs to remove AFM cantilevers from SEM } stubs after examination without breaking them. Standard SEM } adhesives are too sticky for him too. } } We cut a square from the adhesive section of a Post-It note, } and used double-stick tape to attach it to the stub with the Post-It } adhesive facing up. It is sticky enough to hold his small samples in } place - if your samples are not too large or heavy, it might be worth } a try. } } Leslie Eibest } SEM lab
-- ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Becky Holdford (r-holdford-at-ti.com) 972-598-1291 (pager) SC Packaging Development Texas Instruments, Inc. Dallas, TX ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
I have commented on advantages of using the MAG-I-CAL sample in the past and will not do so again here.
I want to comment on Richard's response below. Before I do so, I want to say that I am an overly enthusiastic supporter and believer in the Small Angle Cleavage Technique (SACT) or MicroCleave(TM) Technique and that South Bay Technology is the only company that makes it and I don't work for them. (I hope that this helps keep any feathers from being ruffled.)
Richard, SACT is a marvelous way of preparing III-V samples very quickly and it is an excellent way of calibrating layer thickness values in the TEM when used in conjunction with high resolution X-ray diffraction. I have a PDF file on the SBT web site (https://www.southbaytech.com) that illustrates how this is done. Search for the Microcleave Kit (model number 520) and then look at the application note number 61. The advantage that the SACT method has is that you can get all the thickness that you need from very thin to very thick. By setting up the appropriate imaging conditions, thickness of the layers can be measured very accurately. Similar to what you have said in your response, you can use them to calibrate the TEM. This is what John McCaffrey did when he created the Mag-i-cal sample. BTW, application note #226 is a poster of the technique that John and I put together and is also available on the SBT web site.
-Scott
Scott D. Walck, Ph.D. PPG Industries, Inc. Glass Technology Center P. O. Box 11472 (letters) Guys Run Rd. (packages) Pittsburgh, PA 15238-0472
Walck-at-PPG.com
(412) 820-8651 (office) (412) 820-8515 (fax)
-----Original Message----- } From: Richard Beanland [mailto:richard.beanland-at-marconi.com] Sent: Wednesday, December 05, 2001 9:39 AM To: Microscopy-at-sparc5.microscopy.com
We use cleaved edge specimens of III-V multilayers. We can measure layer thicknesses in-house to a good accuracy (~0.1%) using high resolution X-ray diffraction, whereas the mag-i-cal is (I believe) only guaranteed to +/- 2%. Measurement errors from TEM negatives puts the error in calibration up to about 0.5%. The thin area on the samples is miniscule and they are very robust. A drawback is that you need to be able to tilt the sample to 45 degrees. As discussed some time ago on this listserver, you need to be careful to eliminate lens hysteresis effects if you want to make your measurements accurate.
Cheers,
Richard Beanland Marconi Caswell Ltd. Towcester, Northants, NN12 8EQ UK
e-mail richard.beanland-at-marconi.com
-----Original Message----- } From: Garber, Charles A. [mailto:cgarber-at-2spi.com] Sent: 03 December 2001 18:53 To: MICROSCOPY BB
-- [ From: Garber, Charles A. * EMC.Ver #3.1 ] --
John M. Basgen wrote: =============================================================== We have been using carbon grating replicas for calibrating the magnification of our TEM images for many years. We are in the process of revising our imaging and morphometry protocols. I am not happy with the precision and longevity of the carbon grating replicas. Are there more precise and/or stronger standards for TEM magnification calibration? The final magnifications of our images range from 3,000 -20,000 X. ================================================================ Have you seen the MAG*I*CAL(tm) TEM Calibration Specimen as described on the SPI website, page URL http://www.2spi.com/catalog/standards/magical.html
It seems to get around most of the problems associated with the carbon grating replicas and although nothing is forever, it is quite robust in comparison and should last quite a long time.
Chuck
=================================================== Charles A. Garber, Ph. D. Ph: 1-(610)-436-5400 President 1-(800)-2424-SPI SPI SUPPLIES FAX: 1-(610)-436-5755 PO BOX 656 e-mail: cgarber-at-2spi.com West Chester, PA 19381-0656 USA Cust. Service: spi2spi-at-2spi.com
Look for us! ############################ WWW: http://www.2spi.com ############################ ==================================================
Below is the result of your feedback form (NJZFM-ultra-55). It was submitted by (microscope-at-tin.it) from http://www.msa.microscopy.com/Ask-A-Microscopist.html on Wednesday, December 5, 2001 at 09:25:51 ---------------------------------------------------------------------------
Email: microscope-at-tin.it Name: Massimo
Organization: None
Education: Graduate College
Location: Torino; Italy
Question: 05 December 2001
Let introduce myself. I am an Italian amateur naturalist. I have a light microscope and I have arranged an iris diaphragm on the collector lens of illuminator system to performing an illumination according to Koehler method. I do not understand well the last procedure step:
{ { Step 4. Now lift the eyepiece out of the body tube and look down the tube at the back lens of the fully-lighted objective. (This is best accomplished by the use of a pinhole eyepiece; an eyepiece with a tiny hole) while looking down the microscope tube, slowly open and close the substage condenser aperture iris diaphragm. It will be seen that closing the aperture iris diaphragm "cuts into" the periphery of the back lens of the objective. For excellent illumination and contrast, approximately º-1/3 of the back lens should be occluded, thus leaving 2/3-3/4 of the back lens illuminated. Then replace the eyepiece in the tube. This step too must be repeated each time a different objective is turned into place on the nosepiece.} }
So just a few questions:
how much would the hole diameter be of the pinhole eyepiece? And in which way would I have to use it? Or what would I expect by seeing throught the hole?
There are some photos or web location where I could see the back lens to become occluded by closing or opening the aperture iris diaphragm? And to understand the meaning of this operation.
Below is the result of your feedback form (NJZFM-ultra-55). It was submitted by (robert.s.mattingly-at-grc.nasa.gov) from http://www.msa.microscopy.com/Ask-A-Microscopist.html on Wednesday, December 5, 2001 at 14:00:05 ---------------------------------------------------------------------------
Email: robert.s.mattingly-at-grc.nasa.gov Name: Bob Mattingly
Organization: NASA Glenn Research Center
Education: Undergraduate College
Location: Cleveland, Ohio, USA
Question: I have heard of an adapter for mounting a Nikon 995 Digital Camera to an Olympus SZH-ILLD Macroscope. I cannot find any information on the manufacturer of an adapter to meet my application. Are you aware of any suppliers? Thanks in advance for your help with this issue.
Our Leica Orthoplan 2 needs to be decontaminated. Fungi have grown on the front surface mirrors in the internal prism of the main stand.
In the past, we had to return the stand to Germany for repair but are wondering if anyone knows of a qualified Leica repair center in the US. Barring this, we would purchase a second Orthoplan 2 main stand if one were available.
Thank you.
-- ############################################################## John J. Bozzola, Ph.D., Director I.M.A.G.E. (Integrated Microscopy & Graphics Expertise) 750 Communications Drive - MC 4402 Southern Illinois University Carbondale, IL 62901 U.S.A. Phone: 618-453-3730 Fax: 618-453-2665 Email: bozzola-at-siu.edu Web: http://www.siu.edu/departments/shops/cem.html ##############################################################
It is a while since our E3 departed, so my memory of the symptoms is a bit rusty. However, a problem we had from time to time was the "U" bend in the vibration isolation block in the pumping lines filling with oil, and thereby preventing any pumping from taking place, once the column has been pumped to a modest vacuum. This would cause the vacuum pumps to fail to start as you described.
The remedy was to disconnect the rubber hoses, pour out the oil, then reassemble and start up.
I do recall seeing the error messages you describe, but whether they were associated with this particular fault I can't now remember.
Tony Garratt-Reed.
At 10:58 AM 12/5/2001 -0800, Gordon Vrololjak wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
They make nice adapters for the 990 to most any scope.
gary g.
At 03:29 PM 12/5/2001, you wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
Thanks to all who responded to this query. There is much more to this than meets the eye. Rather typical in this field it seems.
Finding a sharp edge seems easy enough. Not so. Sharp is sharp but really sharp is hard to find. At 200KX, sharp is not so sharp. I used some xxxx maker's apertures only to find that they were not so sharply defined. I tried two others and found that they too were not sharp. I finally found one of my Amray 70u Au coated apertures to be sharp enough to use. I had to tilt it to make a truly sharp edge. The trick is to increase contrast, decrease brightness and slow scan the image at 200KX. Then, do the line scan. I go the following results:
With my Amray FESEM, higher CL# means smaller spot size. So the spot size numbers seem to jive.
This is no small feat to measure!! The key is to do the slow scan first and then do the line scan. Otherwise, there is too much mechanical noise and human interference (coughing) which corrupts the results.
I'm going to do CL15 and CL20 tomorrow and see what I get.
I intuitively see the rationale for how this works. It becomes more obvious as I work with it. The Gaussian aspects are surprising yet rather logical. A 3D plot of a spot would surely look like this. -- good stuff.
A recent example image is at http://photoweb.net/spot-23.tif
Thanks.
gary g.
At 03:53 PM 11/26/2001, you wrote: } The SEM spot size can be measured by doing a line scan across a sharp edge. } For more details see the SEM lab workbook by Lyman et al., 1990. } } Krassimir Bozhilov. } } } } } } Hi all: } } } } Is there any direct way to quantitatively determine } } and measure the actual spot size of a SEM beam? } } } } Given various KV, WD, final aperture sizes, condenser lens } } settings, etc., is there a way to truly find out what } } the real spot size is on the specimen? } } } } Any ideas? } } } } gary g. } } } }
Hi, Alan and Listers- } } I am interested in gaining insight into the role of microscopic artifacts } in the history of biology.
Although I 'm sure there are examples of misinterpretation of artifacts that have been perpetuated for many years, I can offer here a story of the flip side. This is about what appeared to be a well-known artifact that turned out to be, in fact, a surprising real structure. It's also an embarrassing personal story!
An undergraduate student was working with some colleagues who were studying the behavior and neurophysiology of the escape response of several species of planktonic copepods (small crustaceans). They had reams of data and were beginning to characterize the responses of the animals to different kinds of stimuli. Each species had it's own characteristic response, but a general picture was beginning to form. There appeared to be two different classes of response though, one type particularly puzzling. The undergrad spent some time in the EM facility with me, using SEM to describe the sensory setae. She expressed an interest in trying TEM and so we went through fixation, embedding, sectioning, etc. I had worked on the tiny beasts for close to 10 years and had found some interesting structures that I worked on from time to time. Copepods were difficult to fix, some species more so than others. So I had concentrated on the "pretty" ones and temporarily given up on the "ugly" ones - the ones with all those myelin body artifacts that I just couldn't seem to avoid. Finally it was time to try to work on them again, so I gave this one particularly difficult species to the undergrad to try to fix and section. She came to me with micrographs, wondering what in the world were those squiggles she saw. I patiently explained that myelin bodies were a fixation artifact, produced when lipids became mobile during fixation, then reformed in these "onion bodies" . I sent her back to work to try again, and she came up with the same results. "What if they aren't an artifact?" she kept asking. I explained that invertebrates do not have such membranous structures; they were artifactual. I brought out the books and papers about myelin body artifacts. I brought out the books and papers that said invertebrates do not have membranous wrappings around their axons. She was unconvinced. In a hurry one day when she was really bugging me I dug through my files and found the decade-old folder to show her I'd seen the same thing - an artifact. "But there's an axon in the middle of each one", she protested, not knowing that was "impossible". I glanced at them impatiently and saw that she was right, but she was running off to class.
Later that day we looked closely and decided that, indeed, the images were a real mess and difficult to interpret, but there was a faint possibility that these weren't classic myelin body artifacts. Whatever it was was certainly reproducible, and these forms appeared every time in the antennal nerve. So we emailed the PIs of the project and told them we might have myelinated axons in the difficult-to-interpret species. It was April1, April Fools' Day, the undergrad's name was April, and they thought it was a joke. After all, the dogma is that invertebrates don't have myelin! Check any biology book.
But by the next day they realized that myelin (OK, "myelin-like structures" for you purists) would instantly and completely explain 10 years' worth of puzzling data.
It took awhile to prove to ourselves (mainly me, since I'd been repeating the dogma for many years) that these structures were real, orderly, and extensive wrappings of membrane around the axons. It took ultrarapid cryofixation and cryosubstitution to really show that the artifactual bodies that had plagued a number of people working on these critters were in truth these surprising, dogma-busting structures.
We made the April the first author on the Nature paper, which came out in April 1999.
I don't take anything for granted anymore! The lesson is: keep an open mind.
For more on the copepod story- Copepod neuroecology http://www.pbrc.hawaii.edu/~petra/copepod.html
Aloha, Tina
http://www.pbrc.hawaii.edu/microangela
**************************************************************************** * Tina (Weatherby) Carvalho * tina-at-pbrc.hawaii.edu * * Biological Electron Microscope Facility * (808) 956-6251 * * University of Hawaii at Manoa * http://www.pbrc.hawaii.edu/bemf* ****************************************************************************
Hi There, I'm interested in mesuring specimen thickness in TEM. In my case these two techniques (covergent beam technique and the spacing Moire franges) can not be applied. I'll apreciate any further suggestion. Thanks in advance M. Jouiad
-------------------------------------------------------- DR. Mustapha JOUIAD
.. does anbody have an idea (... or even better plans) how to build a more or less "homebrewn" probecurrentmeter (... FEGSEM -} pA resolution needed) ... a comercial instrument is probably to expensive??? (} = 10TDM,- = 5000€,- ???) .. i just had to learn that this is a very useful tool!!!
Hi, Mustapha, you could try EELS for that; the method can give you a very precise value for local thickness.
Corneliu Sarbu, PhD MTMDept. Belgium
- - - - - - - - - - - - - - Original Message - - - - - - - - - - - - - - ------------------------------------------------------------------------ The Microscopy ListServer -- Sponsor: The Microscopy Society of America
Hi There, I'm interested in mesuring specimen thickness in TEM. In my case these two techniques (covergent beam technique and the spacing Moire franges) can not be applied. I'll apreciate any further suggestion. Thanks in advance M. Jouiad
-------------------------------------------------------- DR. Mustapha JOUIAD
Thanks to everyone who responded to my request for information about flatbed scanners! There appears to be a number of very good instruments out there. Thanks for your suggestions!
Ken --
Kenneth M. Bart Director, Electron Microscopy Facility Hamilton College Clinton, New York 13323
I would not think that specimen current is independent of spot size. In fact, I go to great lengths to adjust KV, WD and spot size to obtain just the right specimen current to image upper metal on microchips underneath 10000A of SiN. I lay down a Schottky barrier for the particular type of passivation and adjust the SEM parameters for best picture. Too high of specimen current produces too many SE and thus charging and bad images. The optimum is just enough SE for detail and plenty of BSE for topography.
I can measure specimen current using my Fluke DMM. If the value is not too low, the Fluke will read it (nA). I also use it to measure gun brightness as part of routine calibration.
I'll try measuring the currents today and see what gives.
gary g.
At 06:00 AM 12/6/2001, you wrote: } Hi } } I am very interested with this topic, and we have done such mesures years } ago, as we buid our lab-made LEED optics, with low energy guns, but with } spot sizes of microns... I have for our Jeol 840 a table buid with } such mesures by an japanese ingenior of Jeol Europe, which gives the spot } size versus WD, Energy, and current. So for exemple, with 10 keV, 10E-11A } and 8 mm WD, it should be 110 angstrom. It's a w type gun. This table is } of course not valuable for an other SEM, and I'll have to built it for our } FE-SEM... } } So, a question : do you have a mesure of the probe current (faraday cup, } or as sample current on carbon tape), corresponding to the condenser } settings you have used ? In case our FE-SEM (Jeol 6700F), Jeol claims that } the spot size is independant of the probe current, and I want to verify } it. And comparaison with an other SEM is interesting too. } } } J. Faerber } IPCMS-GSI } (Institut de Physique et Chimie des Matériaux de Strasbourg } Groupe Surface et Interfaces) } 23, rue de Loess } 67037 Strasbourg CEDEX } France } } Tel 00 33(0)3 88 10 71 01 } Fax 00 33(0)0 88 10 72 48 } E-mail Jacques.Faerber-at-ipcms.u-strasbg.fr
I would like to add a comment to John's discussion on calibration samples. I used both the diffraction gratings and the latex spheres prior to John's development of the Mag-i-cal sample. I found that over the overlapping magnification range that both were suitable, they did not agree. Further, I did see changes in the latex spheres at long exposures --I believe it was when I used a lower energy microscope.
I had to do periodic QS9000 (automotive industry equivalent to ISO-9000) calibration procedures for the microscope. With the Mag-i-cal sample, all of the microscope calibrations can be done with one sample very quickly. It is the only way to go.
-Scott
Scott D. Walck, Ph.D. PPG Industries, Inc. Glass Technology Center P. O. Box 11472 (letters) Guys Run Rd. (packages) Pittsburgh, PA 15238-0472
Walck-at-PPG.com
(412) 820-8651 (office) (412) 820-8515 (fax)
-----Original Message----- } From: John McCaffrey [mailto:john.mccaffrey-at-nrc.ca] Sent: Thursday, December 06, 2001 1:07 PM To: Microscopy listserver
You can also determine specimen thickness with electron energy loss spectroscopy (EELS) by applying the log-ratio technique to the low loss spectra (see Egerton, Electron energy loss spectroscopy in the electron microscope, New York: Plenum, 1996). This technique yields a result in units of the mean free path for inelastic scattering.
Mustapha Jouiad wrote:
} Hi There, } I'm interested in mesuring specimen thickness in TEM. In my case these two } techniques (covergent beam technique and the spacing Moire franges) can not be } applied. I'll apreciate any further suggestion. } Thanks in advance } M. Jouiad } }
-- _____________________________________________________ Tyrone L. Daulton Director: Marine Geosciences - Electron Microscopy Center Physicist and Senior Electron Microscopist
Naval Research Laboratory Marine Geosciences Division (Code 7400) Stennis Space Center, MS 39529-5004
I have completed many measurements of spot size and specimen current. Tabular data can be found at http://photoweb.net/SEMLog.pdf
This SEM is a Schottky field emission scope. One of the routine periodic checks is to measure the gun brightness. The spec is 12.5nA. This gun is doing 13.81nA and is just a bit higher than the +-1.5nA limits. The method of correcting this is to adjust the extractor voltage by 100 Volt increments and see how the brightness changes after about an hour. Then, once stable, that is the new extractor voltage. Extractor current can vary greatly whereas the gun brightness is quite steady.
Gun brightness is measured with a 4-digit Fluke 79-III DMM connected to the stage alarm BNC jack. The beam is directed into a Faraday cup located on the stage, CL is opened up to -35 and mag is set to 150KX. The voltage reading on the DMM divided by 1E7 (10 Meg Ohms) is the current at the Faraday cup. I used this same method for measuring specimen current with the target aperture for measuring spot size.
The numbers are somewhat believable. However, at low CL values, the specimen current became negative. So I suspect that this method does not work for really low values of specimen currents.
Can anyone comment on the sanity level of the spot size values I have derived? Are these reasonable for a FESEM at 10KV, 4mmWD, and 100u final aperture?
tnx, gary g.
At 06:00 AM 12/6/2001, you wrote: } Hi } } I am very interested with this topic, and we have done such mesures years } ago, as we buid our lab-made LEED optics, with low energy guns, but with } spot sizes of microns... I have for our Jeol 840 a table buid with } such mesures by an japanese ingenior of Jeol Europe, which gives the spot } size versus WD, Energy, and current. So for exemple, with 10 keV, 10E-11A } and 8 mm WD, it should be 110 angstrom. It's a w type gun. This table is } of course not valuable for an other SEM, and I'll have to built it for our } FE-SEM... } } So, a question : do you have a mesure of the probe current (faraday cup, } or as sample current on carbon tape), corresponding to the condenser } settings you have used ? In case our FE-SEM (Jeol 6700F), Jeol claims that } the spot size is independant of the probe current, and I want to verify } it. And comparaison with an other SEM is interesting too. } } } J. Faerber } IPCMS-GSI } (Institut de Physique et Chimie des Matériaux de Strasbourg } Groupe Surface et Interfaces) } 23, rue de Loess } 67037 Strasbourg CEDEX } France } } Tel 00 33(0)3 88 10 71 01 } Fax 00 33(0)0 88 10 72 48 } E-mail Jacques.Faerber-at-ipcms.u-strasbg.fr
I have an old Olympus IMT-2 inverted scope. It has sliders for inserting filters into the light path for fluorescence imaging. Right now I can only image two fluorophores limited by my slider slots. Does anyone know of some way I can image three dyes, i.e. a filter cube or expanded slider system, specifically for the IMT-2?
John, I'd just like to add a couple of points - I'd like to make it clear that I do think that the the mag-i-cal specimen is probably the best commercially available calibration sample. I didn't mean to be disparaging! It's much better than diffraction grating replicas or other commercially available calibration specimens - it beats diffraction grating replicas in that you can use the crystallography to eliminate specimen tilting and is also more stable. Also, both this and the SACT technique have the advantage that you don't need large tilts and could be used in a single tilt holder.
The extent to which you calibrate your microscope depends on what you use it for - you can get a very accurate relative calibration by taking pictures of the same region at different magnifications. You are only then limited by how accurately you can measure features on the negative (0.05 mm in 5cm is readily achievable with the right specimen and a lupe, which gives you 1% relative accuracy). Once you get down to layers below 100 atomic layers thick then of course it becomes impossible to get better than 1% accuracy with HRTEM. Lack of contrast between the different layers can make things even worse at larger thicknesses for some samples.
The 0.1% layer thickness accuracy I quoted was for X-ray diffraction, and for the right sample XRD does beat TEM every time in terms of accuracy. However, most device structures can't be measured using superlattice fringes in XRD and that is where TEM comes in. Of course we're only measuring thickness because it is a measure of device performance; really thin layers, below 100 atomic planes thick, are usually only used as quantum well structures, delta-doping layers or etch stops, the effectiveness of which can usually be assessed by means more relevant to the device performance than layer thickness (e.g. PL, sheet carrier density, overetching). (I am unaware of any applications which need high accuracy from thin layers apart from microelectronics(?))
I do XRD with a 1mm spot on the sample I use for calibration and make a cleaved edge specimen from a region as close as possible to that position. With a 1% thickness variation over a 3" wafer I'm happy that this is truly representative. With lattice matched III-V layers you can grow as thick as you like, and you get better contrast in dark field 002 images. The downside is that the samples are less stable chemically and physically than Si/SiGe which doesn't lend itself to commercial supply (I certainly wouldn't like to put 100 InP cross sections in the post with a bet that more than 50% would arrive unscathed).
Richard Beanland Marconi Caswell Ltd., Caswell, Towcester, Northants NN12 8EQ UK
e-mail richard.beanland-at-marconi.com
-----Original Message----- } From: John McCaffrey [mailto:john.mccaffrey-at-nrc.ca] Sent: 06 December 2001 18:07 To: Microscopy listserver
Hello John,
While I noted that you weren't too happy with the replica samples, these calibration samples (particularly the cross grating replica samples) are probably still the best choice for the calibration ranges in which you are working. A common cross-grating replica (see, for example, http://www.2spi.com/catalog/standards/othertem10.html) has a line density of 2160 lines/mm, which would give you a line spacing on your negatives of 1.39 mm -at- 3000X and 9.26 mm -at- 20,000X. This length would allow you to measure tens of spacings at all of your magnification ranges, and cut your uncertainty down to reasonable levels. While the edge definition of the grating replicas is not the greatest, and while you may have to replace the sample every year or two, these calibration samples are still among the most simple to use, as well as being reliable and reproducible. They are also inexpensive. Other options include latex spheres, which are in the size range that would be useful for your required magnification ranges. The down-side of these samples is that the spheres have a stated average value, so measurements of many spheres are required to lower the uncertainty to the desired level. Also, there is some anecdotal evidence that these spheres change size when exposed to higher electron doses. If your requirement included the entire set of magnification ranges of your TEM, the MAG*I*CAL sample is still the best bet. (Disclaimer: I "invented" the sample, but will attempt to stay objective about it's merits!). Since this sample and all other samples based on crystal lattice spacings rely on fundamental constants of nature, they are the most accurate and precise samples currently available. However, in spite of this glowing pedigree, crystal-based calibration samples still cannot give measurements with better than ~1% uncertainty. The response to your enquiry from Richard Beanland claiming 0.1% accuracy for cleaved III-V multilayers is a bit misleading (not to mention that he disparagingly compared this supposed superior uncertainty to my beloved MAG*I*CAL!). His layer thickness confidence is based on X-ray diffraction (XRD) measurements. XRD gives very accurate layer thickness measurements, but these measurements are averaged over enormous surface areas in TEM terms - the diameter of the x-ray beam, which can be significant fractions of a square mm. This is a very useful measurement for a layer thickness, but this does not translate directly into uncertainty in a TEM. When a semiconductor multiplayer is viewed in cross section, there are a series of contributors to the layer measurement uncertainty: The state-of-the-art TEM's have resolutions of approximately 0.2 nm. The (002) lattice spacings in most semiconductors (the atomic layers parallel to the surface in most wafers) are a little below 0.3 nm. This means that any measurement of a thicker semiconductor layer in a TEM is going to have a "TEM uncertainty" of approximately one atomic layer at each interface. Producing a semiconductor crystal interface that is perfectly, atomically abrupt (even over the relatively small volume of material used in high resolution TEM) is not trivial, and rarely claimed. Any additional atoms from layer A mixed into layer B, or vice versa, will tend to blur the interface when viewed in cross-sectional TEM. This "epitaxial layer" uncertainty is also approximately one atomic layer at each interface. Highly competent crystal growers can minimize, but not eliminate this interfacial intermixing, allowing the combination of the "TEM uncertainty" and the "epitaxial uncertainty" into one atomic layer at each interface. Semiconductor multilayers can only be grown up to a certain critical thickness, at which point the differences in lattice parameter between the adjoining layers becomes so great that the crystal 'relaxes' with the generation of misfit dislocations at the interface. These dislocations need to be avoided in a calibration sample, but the contrasting layer needs to be grown as thick as possible to minimize the influence (i.e., the percentage) of the two points above. Over an entire semiconductor wafer, there will be systematic thickness variations; i.e., layers may be slightly thicker in the middle of the wafer than at the edge. This is a fairly small, but still significant variation - typically less than 1%. Therefore, it becomes important to know where on the wafer your piece of material comes from. So, why can't the "God-traceable" crystal-based TEM calibration samples give measurements with better than ~1% uncertainty? From the combination of uncertainties given above! The thinnest SiGe marker layers in the MAG*I*CAL sample are approximately 10.0 nm thick, and considering their two interfaces to be uncertain in the worse case to approximately one atomic spacing each, this interfacial contribution to uncertainty is about 0.6%. Coupled with the {1% uncertainty across the entire MAG*I*CAL wafer gives a total uncertainty of ~2%, with a safety margin built in. Richard Beanland did correctly imply the important point that, if one wishes to internally calibrate one's own sample against a known lattice spacing on that same sample, the uncertainties will indeed be less. However, 1% uncertainty is a better estimate of the 'best' uncertainty available in a TEM calibration sample, even for a sample based on a fundamental constant of nature. Cheers John
John P. McCaffrey, Ph.D. Institute for National Measurement Standards National Research Council of Canada M-35 Montreal Road Labs Ottawa, Ontario K1A 0R6 CANADA
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } We use cleaved edge specimens of III-V multilayers. We can measure layer } thicknesses in-house to a good accuracy (~0.1%) using high resolution X-ray } diffraction, whereas the mag-i-cal is (I believe) only guaranteed to +/- 2%. } Measurement errors from TEM negatives puts the error in calibration up to } about 0.5%. The thin area on the samples is miniscule and they are very } robust. A drawback is that you need to be able to tilt the sample to 45 } degrees. As discussed some time ago on this listserver, you need to be } careful to eliminate lens hysteresis effects if you want to make your } measurements accurate. } } Cheers, } } Richard Beanland } Marconi Caswell Ltd. } Towcester, } Northants, } NN12 8EQ } UK } } e-mail richard.beanland-at-marconi.com } } -----Original Message----- } } From: Garber, Charles A. [mailto:cgarber-at-2spi.com] } Sent: 03 December 2001 18:53 } To: MICROSCOPY BB } Subject: TEM Calibration } } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } -- [ From: Garber, Charles A. * EMC.Ver #3.1 ] -- } } John M. Basgen wrote: } =============================================================== } We have been using carbon grating replicas for calibrating the magnification } of our TEM images for many years. We are in the process of revising our } imaging and morphometry protocols. I am not happy with the precision and } longevity of the carbon grating replicas. Are there more precise and/or } stronger standards for TEM magnification calibration? The final } magnifications of our images range from 3,000 -20,000 X. } ================================================================ } Have you seen the MAG*I*CAL(tm) TEM Calibration Specimen as described on the } SPI website, page URL } http://www.2spi.com/catalog/standards/magical.html } } It seems to get around most of the problems associated with the carbon } grating replicas and although nothing is forever, it is quite robust in } comparison and should last quite a long time. } } Chuck } } =================================================== } Charles A. Garber, Ph. D. Ph: 1-(610)-436-5400 } President 1-(800)-2424-SPI } SPI SUPPLIES FAX: 1-(610)-436-5755 } PO BOX 656 e-mail: cgarber-at-2spi.com } West Chester, PA 19381-0656 USA Cust. Service: spi2spi-at-2spi.com } } Look for us! } ############################ } WWW: http://www.2spi.com } ############################ } ==================================================
Hi All, I am attempting to make very accurate measurements of optical coating thicknesses ( {1%), sampling regions a couple of microns or less in size. This isn't possible with SEM or TEM due to interfacial mixing and/or lack of contrast between the layers. (No matter how well calibrated the microscope may be!) One tool which may do the job (and be more relevant to device performance) is a microspectrophotometer such as a 'Nanospec' - or possibly a spectroscopic ellipsometer with very small spot size. Is anyone aware of such a tool I could try in the UK (I am unable to raise the suppliers of Nanospec tools). Alternatively is there another (preferably optical) technique I could use which could also give relevant data?
Mnay thanks for any ideas you may have,
Richard Beanland, Marconi Caswell Ltd., Caswell, Towcester, Northants NN12 8EQ UK
- KE development www.kedev.com range approx 1 pA - 2 µA price approx 1200 €
- Keithley www.keithley.com range approx 0.02 pA - 20 mA price approx 2000 € (model 6485)
sincerely,
Jean Louis HEITZ
CRITT Matériaux-LNE Est 19 rue de Saint Junien, BP 23 F - 67305 SCHILTIGHEIM CEDEX tel. +33(0) 388 191 510 fax +33(0) 388 191 514 jl.heitz-at-critt.fr www.critt.fr
Hello, I have been dealing with SEM/EDS for only 1.5 years and I have a lot to learn, but recently I have been asked a question: What is the EDS depth of penetration on my unit? I work with Amray 1645 and it was upgraded by PGT for imaging and EDS. Could anybody answer the question How deep does the x-ray beam penetrates through a sample and, if it is varies, how to find out actual depth?
hi all, i am doing collagen extractions from corneas and negative staing them to get the lenghts. my problem is that i am having trouble getting the collagen to stick to the formvar. any suggestions. i am on a deadline to work out the details of this project. John
I have an older SEM which over a period of several months seems to repeatedly develop a small droplet of oil on the EDS detector collimator.
It is a diffusion pumped system. The mechanical backing pump is regularly serviced and gets oil changes.
I am inclined to think it is time to clean the diffusion pump and change the oil there. Perhaps over time backstreaming from the mechanical pump has occurred, causing contamination of the diffusion pump oil with mechanical pump oil. The latter, which has higher vapor pressure, is evaporating out of the diffusion pump into the chamber and condensing on the coldest point there (the detector).
Any opinions on whether this is reasonable or not? Any other possibilities anyone can think of? I'd hate to change the diffusion pump oil, which is going to be a big pain, if this is not going to do the trick.
By the way, I'm already planning to install a foreline trap (there currently isn't one).
Thanks,
Wharton
********************************************************** Wharton Sinkler UOP LLC Des Plaines, IL
If the pattern is the same, the signal is probably still reflected light. This signal can be very large compared to fluorescence and it is just blasting through (or around) the filters/prism.
Jim Pawley
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
-- **************************************** Prof. James B. Pawley, Ph. 608-263-3147 Room 223, Zoology Research Building, FAX 608-265-5315 1117 Johnson Ave., Madison, WI, 53706 JBPAWLEY-at-FACSTAFF.WISC.EDU "A scientist is not one who can answer questions but one who can question answers." Theodore Schick Jr., Skeptical Enquirer, 21-2:39
----- Forwarded by Robert Fowler/TCU/TDK-US on 12/07/2001 09:54 AM -----
"Monson, Frederick C." To: "'robert.fowler-at-tdktca.com'" {fmonson-at-wcupa {robert.fowler-at-tdktca.com} .edu} cc: Subject: RE: Aluminum Stubs - Long Version 12/07/2001 09:48 AM
Thanks for pointing the direction. The only sand blasting I have any recollection of was many years ago when you could take your spark plugs to Pep Boys and use a machine they had for public use. Like the fluoroscope in Buster Brown(?), they too have disappeared.
Thanks again Bob, I appreciate your time and consideration,
Regards,
Fred
} ---------- } From: robert.fowler-at-tdktca.com } Sent: Friday, December 7, 2001 9:03 AM } To: Monson, Frederick C. } Subject: RE: Aluminum Stubs - Long Version } } } Hello again Mr Monson, } In the past you have taken the time to help me with a problem on my SEM } so } I will take the time to fill you in on the details of my procedures. Due } to } liability reasons I have to say that these are my own procedures and I } cannot endorse anyone using these (reference only). All materials required } are readily available from McMASTER-CARR WWW.MCMASTER.COM } } P/N } Price } 1- Self Contained Vacuum 9808T44 450.00 } 2- HEPA Filter 9808T47 89.00 } 3- Blasting Cabinet 33005K71 250.00 } 4-Media (170-325 mesh) 3386K75 37.00 } 5-Media (60-120 mesh) 3386K72 35.00 } } Stubs are placed in an appropriate holder. This will vary slightly with } the } style of stubs used. A piece of 12 inch square of aluminum with 1/8" or } 1/4" holes is fine. This is placed in the blasting cabinet. Vacuum turned } on. Air supplied is usually run at 35 PSI. If residue is thick (most of } the } time some tapes such as double sided carbon tape can be mostly removed } before blasting) then a higher (50 PSI) air pressure is required. Parts } are } blasted until visibly clean. 170-325 mesh media will produce a matte } finish. 60-120 mesh grit will produce a glossier finish and removes } residues faster. After blasting parts are removed and cleaned in } ultrasonic } wash using DI water. Distilled water is fine. This wash is repeated three } times. The following are clips from correspondence about cleaning stubs. } } Robert, } I also bead-blast stubs. Works very well as long as you're not looking } for a smooth surface, then you have to grind and polish afterwards, but } the bead blasting DOES clean that top surface in a hurry. On Al I } usually only blast at 35psi to keep the erosion down. } } I have several pieces of Al that have a lot 1/8" holes drilled in them. } Load'em up with stubs and blast away! It's fast, it's fun and } reasonably ecologically sound. Follow with a BRIEF ultrasonic bath in } JOY, rinse with tap, DI or distilled water, depending on how particular } you are, and dry. Alconox and some of the other heavy-duty lab cleaners } have a pH that is far too high for Al, although they work great on glass. } } Ken Converse } owner } Quality Images } third party SEM service } Delta, PA } } -- [ From: Garber, Charles A. * EMC.Ver #3.1 ] -- } } Hi Robert, } } You are quite correct, this is undoubtedly the "best" way to clean sample } mounts for reuse. However, we have had several concerns, and that is why } we } have not recommended it ourselves when people ask: } } a) In a large central facility, some of the remains of samples could } contain hazardous materials which would then end up contaminating the } media } and in the end, while you have clean sEM mounts, there is created a large } volume of hazardous waste, and } } b) How would you really know that the "cleaned" mounts were really } "clean" } and in a virgin pristine state? In other words, what would be the "test"? } } I would be curiously as to how you approach those two issues. We } ourselves } have to think about liability issues, and that is why we have not } aggressive } promoted this as a means for people to clean and reuse their "used" SEM } mounts. WE even considered offering a recycling service, and doing mount } cleaning here, but I did not know how to protect the health and safety of } my } people when handing the waste mounts from other laboratories. } } Chuck } } PS: Please remember that we are nearly 100% paperless and we would ask } that any reply to this message be by way of the "reply" feature on your } software, so that the entire string of correspondence can come back to us } and all be in one place. } } =================================================== } Charles A. Garber, Ph. D. Ph: 1-(610)-436-5400 } President 1-(800)-2424-SPI } SPI SUPPLIES FAX: 1-(610)-436-5755 } PO BOX 656 e-mail: cgarber-at-2spi.com } West Chester, PA 19381-0656 USA Cust. Service: spi2spi-at-2spi.com } } } Look for us! } ############################ } WWW: http://www.2spi.com } ############################ } ================================================== } } } Hello Mr Garber } In response to your e-mail } a) The actual blasting unit that I use is relatively small in size. (2 ft } square) The volume of media used is around 3 quarts. In the eight years I } have been cleaning stubs the media has been changed maybe twice. This } material is treated as hazardous waste and disposed of accordingly. In my } opinion this is a small amount to dispose. Of course the relatively small } amount of stubs cleaned weekly (50 pcs) has a direct impact on media life. } I am not sure of most facilities volume, but if handled correctly } (dedicated blasting unit) this should not create problems. } b) That is a very good question. I honestly do not know of a procedure to } test to confirm the stubs are actually "clean" } } } -- [ From: Garber, Charles A. * EMC.Ver #3.1 ] -- } } Many thanks for sharing that information with us. I am sure some of my } other } people will find it interesting. As I think I indicated, we have long } thought of a mechanism for "recycling" used mounts for people (many just } throw them out) but these other considerations have generally stopped us } dead in our tracks. But within a given laboratory, like yours, you would } pretty much know what was or was not on the mounts, and therefore would } know } how to properly protect yourself from exposure to bad things. } } } } Robert Fowler } Quality Assurance Technician (Failure Analysis) } TDK Components USA, Inc. } Multilayer Ceramic Capacitor Division } 1 TDK Boulevard } Peachtree City GA 30269-2051 } Telephone: (770) 631-0410 Ext.315 } Fax: (770) 487-1460 } email: rfowler-at-tdktca.com } www.tdk.com } } } } } "Monson, } } Frederick C." To: } "'robert.fowler-at-tdktca.com'" } {fmonson-at-wcupa {robert.fowler-at-tdktca.com} } } .edu} cc: } } Subject: RE: Aluminum Stubs } } 12/05/2001 } } 10:38 AM } } } } } } } } } } Morning Bob, } Would you mind telling me/us how you accomplish the sandblasting of } your used stubs. A real materials and methods paragraph would be most } helpful for us biologists in the audience. I will soon be surrounded by } bags of the things and I keep on finding more. Have tried sanding and } some } other methods, but all either mar the surface unsatisfactorily or leave } residue. } } Thanks in advance, } } Fred Monson } } Frederick C. Monson, PhD } Center for Advanced Scientific Imaging(CASI) } West Chester University of Pennsylvania } Schmucker Science Center II } South Church Street } West Chester, PA, 19383 } eMail: fmonson-at-wcupa.edu } http://darwin.wcupa.edu/casi/ } } } } ---------- } } From: "robert.fowler-at-tdktca.com"-at-sparc5.microscopy.com } } Sent: Tuesday, December 4, 2001 12:45 PM } } To: Microscopy-at-sparc5.microscopy.com } } Subject: Aluminum Stubs } } } } ------------------------------------------------------------------------ } } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } } -----------------------------------------------------------------------. } } } } } } Dear Listers, } } Given that my curiosity is up per the plating/no plating of the stubs, } my } } posting is geared more towards the actual reusing of stubs. For the past } } eight years I have been subjecting a set of 50 or so stubs to a sand } } blasting treatment. You may question the feasibility of a sandblaster } BUT } } what is important is the media used to blast with. glass beads in the } } range } } of 170-325 mesh are used to effectively remove residue, glue, tape, and } } any } } material that resides on the stub. This particular media results in no } } residue and no tolerance change, although a pure water treatment and } } ultrasonic wash are utilized. I have had no trouble at all even after } this } } amount of time. } } } } Robert Fowler } } Quality Assurance Technician (Failure Analysis) } } TDK Components USA, Inc. } } Multilayer Ceramic Capacitor Division } } 1 TDK Boulevard } } Peachtree City GA 30269-2051 } } Telephone: (770) 631-0410 Ext.315 } } Fax: (770) 487-1460 } } email: rfowler-at-tdktca.com } } www.tdk.com } } } } } } } } } }
I apologize to all who recently received a queer email from me. I was hit by s new virus W32Aliz . Worm which my antivirus failed to detect and which is spreading in Microsoft Outlook Express without you open any atachment. Jiri Kalvoda
--- Odchozí zpráva neobsahuje viry. Zkontrolováno antivirovým systémem AVG (http://www.grisoft.cz). Verze: 6.0.306 / Virová báze: 166 - datum vydání: 4.12.2001
I apologize to all who recently received a queer email from me. I was hit by s new virus W32Aliz . Worm which my antivirus failed to detect and which is spreading in Microsoft Outlook Express without you open any atachment. Jiri Kalvoda
--- Odchozí zpráva neobsahuje viry. Zkontrolováno antivirovým systémem AVG (http://www.grisoft.cz). Verze: 6.0.306 / Virová báze: 166 - datum vydání: 4.12.2001
These are fundamental questions that you can learn about from a number of text books and courses. I would suggest starting with the SEM and Microanalysis book by Goldstein et al. You could also think about attending the Lehigh Microscopy Short Course which is very good and would teach you these things. David Joy has some Monte Carlo simulation software in the public domain that calculates these things and graphically displays them. You can get them at the EMMPDL - MASLIB - Mac & PC Shareware Libraries at Argonne National Laboratory. The following FTP Site give you access to these Software Libraries. Access is by anonymous Login:
Host : WWW.AMC.ANL.GOV or the mirror site WWW.MSA.Microscopy.Com
Login: Username = Anonymous Password = Your Email Address
You will have to hunt for them. Go to the main listing and look at the titles.
-Scott
Scott D. Walck, Ph.D. PPG Industries, Inc. Glass Technology Center P. O. Box 11472 (letters) Guys Run Rd. (packages) Pittsburgh, PA 15238-0472
Walck-at-PPG.com
(412) 820-8651 (office) (412) 820-8515 (fax)
-----Original Message----- } From: ATC SEM Laboratory [mailto:atcsem-at-earthlink.net] Sent: Friday, December 07, 2001 8:09 AM To: Microscopy-at-sparc5.microscopy.com
Hello, I have been dealing with SEM/EDS for only 1.5 years and I have a lot to learn, but recently I have been asked a question: What is the EDS depth of penetration on my unit? I work with Amray 1645 and it was upgraded by PGT for imaging and EDS. Could anybody answer the question How deep does the x-ray beam penetrates through a sample and, if it is varies, how to find out actual depth?
If you have not lost cooling efficiency in the cold trap at the top of the diffusion pump or in the lines around the diffusion pump, I would wager that it is not diffusion pump oil. Check the cooling lines for adequate flow. If they are plugged, you could get diff pump fluid up in the chamber. Chances are that it is mechanical pump fluid. I trap will help, but you have to maintain it properly. To get rid of the oil in the chamber, there are some things that you could do. I recommend the Evactron system by XEI. I have checked it out (see the M&M 2001 proceedings) and it does clean up hydrocarbon oils in a vacuum chamber. XEI also has an overnight nitrogen purge system that helps clean microscope by using clean dry nitrogen. A colleague at one of our other research sites has this system on an older SEM and it really helps to keep beam contamination down. You could set up your own system with a leak valve and a pump that throttles the vacuum pump. You then keep the system in the viscous flow regime and it will clean the system. Better yet, you can put heaters on the tubing to heat the nitrogen going into this system and it will improve the "scrubbing" action of the gas molecules on the surface of the chamber.
-Scott
Scott D. Walck, Ph.D. PPG Industries, Inc. Glass Technology Center P. O. Box 11472 (letters) Guys Run Rd. (packages) Pittsburgh, PA 15238-0472
Walck-at-PPG.com
(412) 820-8651 (office) (412) 820-8515 (fax)
-----Original Message----- } From: Sinkler, Wharton [mailto:WSinkler-at-uop.com] Sent: Friday, December 07, 2001 8:42 AM To: 'Microscopy-at-MSA.Microscopy.Com'
Dear Listers,
I have an older SEM which over a period of several months seems to repeatedly develop a small droplet of oil on the EDS detector collimator.
It is a diffusion pumped system. The mechanical backing pump is regularly serviced and gets oil changes.
I am inclined to think it is time to clean the diffusion pump and change the oil there. Perhaps over time backstreaming from the mechanical pump has occurred, causing contamination of the diffusion pump oil with mechanical pump oil. The latter, which has higher vapor pressure, is evaporating out of the diffusion pump into the chamber and condensing on the coldest point there (the detector).
Any opinions on whether this is reasonable or not? Any other possibilities anyone can think of? I'd hate to change the diffusion pump oil, which is going to be a big pain, if this is not going to do the trick.
By the way, I'm already planning to install a foreline trap (there currently isn't one).
Thanks,
Wharton
********************************************************** Wharton Sinkler UOP LLC Des Plaines, IL
Thanks for the note. I didn't take your remarks as disparaging - however, I did take advantage of them to have a little fun!
I now work for the NRC Institute for National Measurement Standards, which is the Canadian equivalent of your NPL, American's NIST, the "world's" BIPM, etc., so issues of traceability and ISO 17025 take up a lot of my time now. The fact that there is no officially traceable, high-magnification TEM calibration sample available has caused me (and probably most microscopists) some extra headaches. I maintain that TEM calibration samples based on crystal lattice spacing are fundamental constants of nature (i.e., "God -traceable") and hence do not require the blessing of a National Measurement Institute. It does occasionally take a bit of persuasion to convince the bureaucratically-minded that the whole point of traceability is not to refer to SI units through a National Measurement Institute, but to refer to nature through all of the above!
As you implied in your original posting, having a crystal as the basis of the sample allows self-calibration at better than the 1% level. Backing that measurement up with XRD is even more convincing. You have a nice advantage in your calibrated measurements in that you can lattice-match your alloy layers, and avoid worries about layer thickness variations as a result of strain. A potential problem with the SiGe marker layers in the MAG*I*CAL sample was that they were strained layers and hence had a slight variation in lattice parameter. We worked around that problem by self-calibrating the thickness of the individual SiGe layer(s)against the pure silicon crystal substrate. Silicon and TEM are a marriage made in heaven - the low atomic number of silicon makes the sample still useful for TEMs with accelerating voltages less than 200 keV. You are also correct about the robustness of Si relative to InP - in my experience, InP crystals will gratuitously cleave under any kind of stress, and usually in exactly the region of interest . . .!
Anyway, I appreciate the opportunity to discuss with you the subtlties of TEM calibration. The topic doesn't work it's way into social conversation very often. . .!
Cheers John
All the best.
Cheers John
John P. McCaffrey, Ph.D. Institute for National Measurement Standards National Research Council of Canada M-35 Montreal Road Labs Ottawa, Ontario K1A 0R6 CANADA
----- Original Message ----- } From: "Richard Beanland" {richard.beanland-at-marconi.com} To: "'John McCaffrey'" {john.mccaffrey-at-nrc.ca} Cc: "'Microscopy-at-MSA.Microscopy.Com'" {Microscopy-at-sparc5.microscopy.com} Sent: Friday, December 07, 2001 5:13 AM
How are you preparing the Formvar?
Films should be freshly carbon coated. If not fresh, should be less than a week old--or if you're still having trouble with non-sticking, carbon coat same day). Also, you can "rejuvenate" them with glow discharge in a vacuum evaporator for 10-30 sec. You can also irratiate them with UV light for 30-40 min.
If neither is available, try poly-L-lysine (FW: 4000; 0.1% aqueous for a couple min, then wash in a couple drops of water); drain, dry). Other possible rx: alcian blue, benzyldimethyl alkylammonium chloride (BAC).
Hayat MA, Miller SE. Negative Staining. McGraw-Hill. 1990.
Sara Miller
On Fri, 7 Dec 2001 JHoffpa464-at-aol.com-at-sparc5.microscopy.com wrote:
} Date: Fri, 07 Dec 2001 08:18:49 EST } From: JHoffpa464-at-aol.com-at-sparc5.microscopy.com } To: microscopy-at-sparc5.microscopy.com } Subject: negative staining } } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } } hi all, i am doing collagen extractions from corneas and negative staing them to get the lenghts. my problem is that i am having trouble getting the collagen to stick to the formvar. any suggestions. i am on a deadline to work out the details of this project. } John } } }
Sara E. Miller, Ph. D. P. O. Box 3712 Duke University Medical Center Durham, NC 27710 Ph: 919 684-3452 FAX: 919 684-3265
Try chroma.com They are a great resource and have lots of information on their web site.
Dave Burton Optical Specialist University of Washington ----- Original Message ----- } From: {"ebhan-at-cybermed.ucsd.edu"-at-sparc5.microscopy.com} To: {Microscopy-at-sparc5.microscopy.com} Sent: Thursday, December 06, 2001 2:32 PM
Dear Wharton and Microscopy List:
The assumption that your oil droplet is roughing pump oil distilled through the diffusion pump is very reasonable and is the most likely source. Michael Postek of NIST wrote a paper on this and a method he came up for control of the problem: "An Approach to the Reduction of Hydrocarbon Contamination in the Scanning Electron Microscope" Scanning Vol. 18, 269-274 (1996). He used a controlled leak into the foreline to stop backstreaming and control the problem. He also dicusses Cryotrps and Nitrogen purge systems as controls. I have reprints available of this article available for the asking. Send me your mailing address. Ric Felton found by IR that his oil drop was coming a oil outgassing from the Japanese Black Rubber vacuum hose supplied with his SEM. The oil can also come in from an airlock if the airlock is pumped continuously by a roughing pump.
I make my living by controling contamination and Oil backsteaming problems in electron microscopes. Doing business as XEI Scientific, I make the both a Nitrogen Purge system and the Evactron SEM-CLEAN Plasma Cleaning system for cleaning Electron Microscopes. Visit my web site at www. SEMCLEAN.COM for details.
Ronald Vane XEI Scientific 3124 Wessex Way Redwood City, CA 94061 (650) 369-0133
-----Original Message----- } From: Sinkler, Wharton {WSinkler-at-uop.com} To: 'Microscopy-at-MSA.Microscopy.Com' {Microscopy-at-sparc5.microscopy.com}
The Integrated Microscopy Core, Department of Molecular and Cellular Biology, Baylor College of Medicine has an immediate full-time opening for an electron microscopy technician. The Integrated Microscopy Core is a busy, state-of-the-art facility with a new Hitachi H7500 equipped with Gatan’s new 2kx2k CCD camera, deconvolution, laser scanning confocal, and 2 CCD-based upright and inverted epifluorescence microscopes. The applicant should have at least one year of experience in various aspects of sample preparation for biological TEM including fixation, embedding, ultrathin sectioning, staining and darkroom procedures. The applicant should have experience in the operation of TEMs and knowledge of computers. Other duties include preparation of solutions, embedding media and the maintaining of records. The position offers opportunities for training in advanced microscopy techniques, including digital TEM, fluorescence, deconvolution and laser scanning confocal microscopy. The position requires a minimum of a Bachelors degree and will start as a Lab Technician II; salary range is in the 30-40K, commensurate with experience, and the standard Baylor College of Medicine benefits package.
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Baylor College of Medicine is an Equal Opportunity, Affirmative Action and Equal Access Employer
I don't think this is a terribly unusual problem. I have operated two scopes with EDS detectors that have also developed oil drops on the end of the snout. The problem is that the collimator is chilled from the liquid nitrogen in the detector dewar, so any oil vapor in the chamber (and there is always some) goes right to it and condenses. If your scope is a variable pressure SEM one thing that helps is to maintain it at 7-10 Pa chamber pressure when not in use. This keeps a certain amount of gas circulating through the chamber and helps to flush out the backstreamed vapors. There is also a product called SEMCLEAN (I think), and I believe it operates on a similar principle.
Good luck, Randy
Randy Tindall EM Specialist Electron Microscopy Core Facility W122 Veterinary Medicine University of Missouri Columbia, MO 65211 Tel: (573) 882-8304 Fax: (573) 884-5414 Email: tindallr-at-missouri.edu Web: http://www.biotech.missouri.edu/emc/
-----Original Message----- } From: Sinkler, Wharton [mailto:WSinkler-at-uop.com] Sent: Friday, December 07, 2001 7:42 AM To: 'Microscopy-at-MSA.Microscopy.Com'
Dear Listers,
I have an older SEM which over a period of several months seems to repeatedly develop a small droplet of oil on the EDS detector collimator.
It is a diffusion pumped system. The mechanical backing pump is regularly serviced and gets oil changes.
I am inclined to think it is time to clean the diffusion pump and change the oil there. Perhaps over time backstreaming from the mechanical pump has occurred, causing contamination of the diffusion pump oil with mechanical pump oil. The latter, which has higher vapor pressure, is evaporating out of the diffusion pump into the chamber and condensing on the coldest point there (the detector).
Any opinions on whether this is reasonable or not? Any other possibilities anyone can think of? I'd hate to change the diffusion pump oil, which is going to be a big pain, if this is not going to do the trick.
By the way, I'm already planning to install a foreline trap (there currently isn't one).
Thanks,
Wharton
********************************************************** Wharton Sinkler UOP LLC Des Plaines, IL
At 09:03 AM 12/7/2001, you wrote: } Dear Gary, } } [snip]
} While I am not familiar with the Amray 1910, I have worked with many other FE } and conventional SEMs and I think your current measurements are not accurate. } In general, as beam currents increases, the spot size should also increase, } which is the opposite of what your data shows.
I would think that this SEM should exhibit the same characteristics as others would. I agree that the relationship of spot size and specimen current is whacky. I attribute this to my poor method of measuring the low specimen currents. As a check, I did the gun brightness test. It was working as normal. But the current value is probably 100 times what actual operating specimen current is. Gun brightness is measured without any final aperture and with condenser lens wide open (-35).
} I also have a graph from JEOL for the spot size vs. beam current for a JEOL } 840, which apparently is similar to what the other writer has. The graph I } have has almost a straight line on a log-log grid that goes through 10 nm at } 10 pA, 50 nm at 1 nA, and 500 nm at 500 nA (this is for a W filament at 30 kV } and the aperture size is increased as the beam current increases). } Unfortunately, the JEOL data does not indicate how the "spot diameter" was } measured.
Assuming we use the same "sharp corner" method, the log-log data means that the relationship is not linear. My data suggests that it is linear. So again, my measurements are suspect. The only thing I seem to find believable about what I measured is that spot size gets smaller at higher CL settings. At least this is a good correlation direction.
} Spot size vs. beam current data from an older Philips FE SEM at 10 kV with a } 30 um aperture is as follows: ~0.5 nm at ~10 pA, ~3.5 nm at ~0.55 nA, and } ~30 nm at ~35 nA. } } It is also interesting that in your data, over the full range of CL settings, } the currents you have measured hardly change, while most SEMs will have a } full range of several orders of magnitude or more. } } If possible, I would suggest you borrow a Keithley 485 picoammeter (or } similar) to check the current measurements you have made. Note that if the } sign of the measurement changes at low beam currents, it indicates that there } is a grounding problem that has a leakage current that is larger (and } opposite) of what you are measuring. Also note, that on a picoammeter like } the 485, the displayed reading when connected to a Faraday cup in an SEM will } always be negative when working correctly.
I ordered a 485. It should be here in two weeks. I'll re-do all measurements when it gets here. Any special notes I should know about when using it? It has a BNC input jack so I'll just coax from it to my stage alarm BNC.
What could I do to check the stage grounding situation? The BNC alarm output is not grounded (shorted). Perhaps I should check the BNC ground side to be sure it is grounded. That would mess things up for sure. But the gun brightness measurement would not have worked correctly.
} My background is in using electron microscopes for e-beam lithography. In } that case, the exposed spot is always larger than the size of the incident } beam. This results from the fact that as soon as the beam hits, there will } be scattering and it is the secondary electrons that have the highest } probability for exposing the resist. For comparison, a high performance FE } SEM at 30 kV and ~20 pA of current can expose lines down to 10 or 20 nm, } which puts an upper limit on the beam size for those models at those } conditions. Since such models have a resolution spec of 1 to 2 nm above 10 } kV, the lithography size is reasonable, since the resolution measurements are } not limited by a resist resolution or by broadening by secondary electrons.
We use Heidelberg DWL to write masks. The laser makes patterns down to about 0.1u which is all we need at 0.25u feature size. It is probably better than that but I have never measured it.
} In general, the approach for measuring resolution is to see how small a gap } the beam can fit between islands of gold. While this approach does not give } any information on the profile of the beam as you are trying to measure, it } certainly gives reasonable data on the "width" of the beam. Quite simply, if } the image is dark when the beam is positioned in a 5 nm gap between to gold } islands on carbon, then it is clear that "most" of the beam is hitting the } carbon and not the gold. It would be interesting if you could correlate your } width measurements to values from a resolution measurement.
there might be another approach to performing a sanity check. I can set up some IC process control monitors which have various geometries of metal fingers meshed between one another. Each set of fingers (E with lots of fingers sticking out) are meshed together but not touching. With 24VDC or 12VDC in the chamber for the stepper motors and limit switches, I could connect one E to +12 and bring the other E out through the picoammeter and place a beam at various points. This ought to cause current flow when the beam transcends two adjacent fingers. Might be worth a shot.
I am still searching for a true sharp corner. They are not all that sharp. At 100KX and above, the detail in their surface shows up and degrades a sharp delineation at the boundary.
Gary G.
} Joe } _________________________________________ } Joe Nabity, Ph.D. } JC Nabity Lithography Systems } E-Beam Lithography using Commercial SEMs & STEMs } PO Box 5354, Bozeman, MT 59717 USA } Voice: (406) 587-0848 } FAX: (406) 586-9514 } E-mail: info-at-jcnabity.com } Web: www.jcnabity.com
This is something we had been experiencing with our SEM and our former beryllium window detector. The X-ray detector had to be removed more than once to wash oil off the window, in spite of having upgrading the diff pump oil to Santovac to try to minimise the contamination. I analysed some of the oil deposited on the collimator by FT-IR and it wasn't Santovac oil, it was backstreaming diff pump oil. Then when we upgraded the X-ray system a couple of years ago to a thin (polymer) window detector, I decided something had to be done about the oil, even though the new detector surfaces weren't so cool as the previous one's.
One problem with foreline traps is that they slow down pumping speed. So I cannibalised a much bigger rotary pump from an old mass spec that was being binned, had it reconditioned, fitted a good foreline trap and haven't looked back. If you can do the same, I'm sure you will be pleased with the effort.
"Sinkler, Wharton" {WSinkler-at-uop.com} on 07/12/2001 13:41:57
To: "'Microscopy-at-MSA.Microscopy.Com'" {Microscopy-at-sparc5.microscopy.com} cc:
Dear Listers,
I have an older SEM which over a period of several months seems to repeatedly develop a small droplet of oil on the EDS detector collimator.
It is a diffusion pumped system. The mechanical backing pump is regularly serviced and gets oil changes.
I am inclined to think it is time to clean the diffusion pump and change the oil there. Perhaps over time backstreaming from the mechanical pump has occurred, causing contamination of the diffusion pump oil with mechanical pump oil. The latter, which has higher vapor pressure, is evaporating out of the diffusion pump into the chamber and condensing on the coldest point there (the detector).
Any opinions on whether this is reasonable or not? Any other possibilities anyone can think of? I'd hate to change the diffusion pump oil, which is going to be a big pain, if this is not going to do the trick.
By the way, I'm already planning to install a foreline trap (there currently isn't one).
Thanks,
Wharton
********************************************************** Wharton Sinkler UOP LLC Des Plaines, IL
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When I get a question about SEM/EDS analysis depth, I refer people to the ASTM E 1508-98 "Standard Guide for Quantitative Analysis by Energy Dispersive Spectroscopy" which is in volume 3.01 if you have the annual books ASTM publishes. In paragraph 8.2.3, there is a rule of thumb to estimate the analysis depth where 99% of the x-rays are emitted. The rest of the guide is also a useful, brief, reference to be familiar with when doing EDS experiments.
Regards, Dave Audette david.audette-at-sylvania.com
Our website about beetles / coleoptera on www.coleoptera.org has been updated
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Keep care and be of good cheer.
Regards
(name) Vratislav Richard Eugene Maria John Baptist (surname) of Bejsak (Bayshark)-Colloredo-Mansfeld
website: http://www.coleoptera.org listserver: coleoptera on www.egroup.com/group/coleoptera/info.html Coleoptera - Australia, Tenebrionidae of World (incl. Lagriinae, Alleculinae)
University of Sydney The Wentworth Bldg., Box 62 NSW 2006 AUSTRALIA phone : +61 414 540 465 email: vratislav-at-bigfoot.com ricardo-at-ans.com.au (before Ricardo-at-compuserve.com and ricardo-at-login.cz )
Only after the last tree has been cut down, only after the last river has been poisoned, only after the last fish has been caught, only then will you find that money can not be eaten.' CREE INDIAN PROPHECY.
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Soda glass, is used in most and especially the cheaper microscope slides. Soda glass does fluoresce. If you look at the slide side on and the glass has any tinge of green, than its soda glass. If you can, just place a couple of coverslips on the stage - hopefully you would not get fluorescence, proving its the slide. The slides to use for any fluorescence applications are the water- white or superwhite slides. These the manufacturer claims, do not fluoresce at all - probably true in normal microscopy situations, but one customer with an extra powerful detection system managed to get some slide fluorescence from the superwhite slides too. Disclaimer: ProSciTech supplies Superwhite slides. Cheers Jim Darley ProSciTech Microscopy PLUS PO Box 111, Thuringowa QLD 4817 Australia Ph +61 7 4774 0370 Fax:+61 7 4789 2313 service-at-proscitech.com Great microscopy catalogue, 500 Links, MSDS, User Notes ABN: 99 724 136 560 www.proscitech.com
On Saturday, December 08, 2001 12:15 AM, James Pawley [SMTP:jbpawley-at-facstaff.wisc.edu] wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } } Russell, } } If the pattern is the same, the signal is probably still reflected } light. This signal can be very large compared to fluorescence and it } is just blasting through (or around) the filters/prism. } } Jim Pawley } } } } ------------------------------------------------------------------------ } } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } } -----------------------------------------------------------------------. } } } } } } Sorry about the subject name, it is a bit misleading. In } } using a Leica SP2 } } confocal, I have noticed that it is possible to see the cover slip } } and slide. Why/how is this possible? The setup is essentially this: } } a coverslip is placed } } on a slide, which is then placed on the stage (there is nothing between them, } } } } except of course for miscellaneous small dust particles and air). The slide } } is } } then scanned with light from a HeNe laser (633nm). When the light detection } } (wavelengths directed to the PMT's) is set to include 633nm (i.e. } } 610-650nm), the } } signal is of course very bright. I am assuming that this is due to } } reflection. What I am confused about is that if the light detection } } doesn't include 633nm } } (sampling from 660-710nm), there is still signal present, and it is } } in the same } } pattern as is seen when looking at the reflected light. It is } } important to note } } that this pattern is connected to the coverslip and slide somehow, } } as moving the } } stage will cause a corresponding change in the image produced by the system. } } I realize that I may be missing something fairly obvious, but } } any help would } } be greatly appreciated. } } } } Thanks, } } Russell } } } } } } } } -- } } Confocal Imaging Facility Technician } } Tufts Medical School } } 136 Harrison Ave. } } Boston, MA 02111 } } Tel. (617) 636-3795 } } -- } **************************************** } Prof. James B. Pawley, Ph. 608-263-3147 } Room 223, Zoology Research Building, FAX 608-265-5315 } 1117 Johnson Ave., Madison, WI, 53706 JBPAWLEY-at-FACSTAFF.WISC.EDU } "A scientist is not one who can answer questions } but one who can question answers." } Theodore Schick Jr., Skeptical Enquirer, 21-2:39
I am an art conservator working in Japan and would like to purchase a pigment reference set and mounting medium but have been unsuccessful in my web searches.
I seem to recall that McCrone and Fisher sold such pigment reference sets--with about 40 or so mounted samples of common artist pigments, but their web pages did not turn up with any such item.
Also, I would like to know what is the best refractive index for medium used to mount pigments? Is is 1.55? When I was in the U.S. I used Cargille mounting medium.
Thank you so much for your assistance, since it is quite difficult for me to find information on this in Japan.
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Dear Wharton, It seems like all of the responses to your inquiry are trying to solve the effect of your problem rather than the cause. The oil that is condensing is most likely mechanical pump oil if your vacuum system is working properly. In any vacuum system using a oil charged mechanical pump and a diffusion pump there will be oil vapors. These oil vapors are also the cause of contamination spots on the sample after the beam has stayed in one location for a period of time. Unless you upgrade your vacuum system to a dry mechanical pump and a turbo molecular pump, oil vapors will be present. Now the cause of your problem is the EDX detector itself. EDX detectors are static vacuum systems. They are initially pumped out; when LN2 is present in the dewar, which is attached to a cold finger holding all of the internal components, cryostatic pumping occurs within the EDX detector. With a well maintained EDX detector, very little thermal loss is transferred to the external portion of the detector. In your case, the internal vacuum of your EDX detector is poor and a high thermal loss causes the EDX tube to be cold and therefore becoming coldfinger within the vacuum system. This coldfinger ( your EDX tube) is now attracting the oil vapor present in your SEM and creating the oil droplets. To solve your problem you need to have a vacuum treatment ( pump-out and bake-out )performed on your EDX detector. If you would like additional information concerning EDX detectors, please visit my web site xraydetectors.com. Regards, Jim Nicolino
"Sinkler, Wharton" wrote: } } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } Dear Listers, } } I have an older SEM which over a period of several months seems to } repeatedly develop a small droplet of oil on the EDS detector collimator. } } It is a diffusion pumped system. The mechanical backing pump is regularly } serviced and gets oil changes. } } I am inclined to think it is time to clean the diffusion pump and change the } oil there. Perhaps over time backstreaming from the mechanical pump has } occurred, causing contamination of the diffusion pump oil with mechanical } pump oil. The latter, which has higher vapor pressure, is evaporating out } of the diffusion pump into the chamber and condensing on the coldest point } there (the detector). } } Any opinions on whether this is reasonable or not? Any other possibilities } anyone can think of? I'd hate to change the diffusion pump oil, which is } going to be a big pain, if this is not going to do the trick. } } By the way, I'm already planning to install a foreline trap (there currently } isn't one). } } Thanks, } } Wharton } } ********************************************************** } Wharton Sinkler } UOP LLC } Des Plaines, IL
"Sinkler, Wharton" wrote: } } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } Dear Listers, } } I have an older SEM which over a period of several months seems to } repeatedly develop a small droplet of oil on the EDS detector collimator. } } It is a diffusion pumped system. The mechanical backing pump is regularly } serviced and gets oil changes. } } I am inclined to think it is time to clean the diffusion pump and change the } oil there. Perhaps over time backstreaming from the mechanical pump has } occurred, causing contamination of the diffusion pump oil with mechanical } pump oil. The latter, which has higher vapor pressure, is evaporating out } of the diffusion pump into the chamber and condensing on the coldest point } there (the detector). } } Any opinions on whether this is reasonable or not? Any other possibilities } anyone can think of? I'd hate to change the diffusion pump oil, which is } going to be a big pain, if this is not going to do the trick. } } By the way, I'm already planning to install a foreline trap (there currently } isn't one). } } Thanks, } } Wharton } } ********************************************************** } Wharton Sinkler } UOP LLC } Des Plaines, IL
Apologies. I have just reread my message and can see the mistake. The analysed oil that had condensed on our detector collimator did not give the characteristic FT-IR spectrum of a polyphenol ether, e.g. Santovac oil, it was rotary pump oil (and not diff pump oil). Hence, a foreline trap was fitted to the rotary pump.
"Garber, Charles A." {cgarber-at-2spi.com} on 08/12/2001 05:19:15
To: "jill.webb-at-rssl.com" {jill.webb-at-rssl.com} cc:
-------- REPLY, End of original message --------
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My FESEM is Schottky ZrOW, thermally assisted. I believe that all Hitachi FESEMs are cold cathode. If so, my experience probably does not apply.
The Schottky filaments have to be "conditioned" prior to use. This process involves having the gun assembly sitting by itself and braid strap grounded to Earth ground. The entire gun electrode set is then brought up to 32KV while a separate gun chamber ion pump power supply is connected and monitored for pump current.
The potential is raised slowly, about 500V per 5 minutes or so. The pump current is constantly watched. If it starts to increase, the potential is reduced, let sit and then raised again. At some point, the unit may zap. This drive the pump current way high and the whole process starts over again. Once the gun assembly can sit at 32KV for an hour with low pump current and no zapping, it is then mounted on the column. It should never zap again during operation at 30KV max rated potential.
When connected to the column and console electronics, a zap will most likely take out some electronics in the system. This is why the gun is conditioned off of the column.
I don't have an emission current control. The only computer controlled setup values are for extractor voltage and suppressor voltage. Once set, they are not adjusted again under normal operation.
I would think that any zapping is an indication of dirt or crud on the gun area. What does Hitachi say about this?
gary g.
At 08:44 AM 12/5/2001, you wrote:
} Dear listers, } } This query is directed specifically at users of the Hitachi S4700 FESEM, but } may also apply more widely to users of FESEM's. } } We get a curious result (to me) when flashing the tip. We were advised to } flash until the emission current reading read about 20uA on the "le" meter. } The flash intensity adjustment behind the scope was initially set to } accomplish this in one or two flashes when flashing at an intensity of "2" } in the Setup-Column menu. } } That is what happened for quite some time, however for a while now flashing } has resulted in values between 7-12 on the "le" meter. The initial flash } briefly degrades the vacuum at the gun as expected as contamination is } driven off, but subsequent flashes do not, also as expected. However, } subsequent flashes usually LOWER the "le" meter value, rather than raise it } toward our goal of 20. This is the really puzzling part to me. Originally, } the value increased with each flash, and if an excessive number of flashes } were required, we would adjust the intensity pot in the rear of the scope. } } We normally run the scope at an emission of 10uA, with kV's of 1.0-10.0. } All vacuum readings are normal, and the scope performs beautifully in terms } of resolution and brightness. } } My questions are: } } 1) Why is the "le" value decreasing with multiple flashes? } } 2) How dangerous are multiple flashes to the tip? } } 3) Does the condition described above indicate any problem with the tip } and/or scope? } } 4) Is flashing actually accomplishing anything if the vacuum gauge shows no } contamination being driven off? } } 5) Is it safe to keep turning up the intensity pot on the rear of the } scope? (Something tells me no.) } } 6) Do I simply not understand what's going on? (Something tells me yes.) } } Thanks in advance! } } Puzzled in Missouri, } Randy } } Randy Tindall } EM Specialist } Electron Microscopy Core Facility } W122 Veterinary Medicine } University of Missouri } Columbia, MO 65211 } Tel: (573) 882-8304 } Fax: (573) 884-5414 } Email: tindallr-at-missouri.edu } Web: http://www.biotech.missouri.edu/emc/
I saved an old Cook CV-301 thermal evaporator from another group from a dumpster and I rebuilt it. It has two sets of boat holders mounted on the base plate. The boat gap is 3" and the clamping screws have 3/16" diameter threads. The bell jar is 12" in diameter by 12" high. Pump down pressure was improved from 10E-3 to 3 - 5 x10E-6, now. I have no accessories for the thing. I have no manuals (hint), no shutter, etc.
I want to set this up as a dedicated old style 1/8" carbon rod and a W basket (mgs of metal) evaporator. I buy my TEM grids but sometimes they are too light on carbon or I would like to increase the conductivity of the carbon 'back coated' formvar grids. Thus, I would like to 'thicken' them up a bit with carbon. I do NOT want to send big 'boulders' of carbon smashing through perfect featureless grid films, however.
So I need to buy a carbon evaporation unit of some type. Should I go with an old style combo unit like Ladd Research sells? Many think carbon fiber / cord / strings are the way to go and the Ladd unit does not appear to do that type of C. Obviously, I would want to have a W basket or W wire setup as a option for my troubles saving this unit.
Ladd sells both combination and separate units to do both jobs and they can be shielded. Have you used one of these? Fullams sells much cheaper priced units, but are unshielded. Have you used them on a non-EFFA evaporator or port? Does the carbon rod spring work smoothly and reliably on any of these units?
What other after market units are reliable based on your REAL experiences and what would you buy today, if you had to do it over again, like me?
One final, low priority, question on DP oil: The Cook is simpler to use than my Edwards 306A but it only has a 400-450 watt DP heater on a Varian HS2 DP. It calls for 100mls of Dow Corning 704 silicone oil. Not my first choice. I think the heater is too small in wattage for Santovac based on my experience with a 1964 JEOL JEM 7 TEM oil conversion attempt. I could try to switch to another DP fluid like Apiezon A, B or a Fomblin. DC 704 boils at about 215°C. So, have you ever done this type of oil conversion successfully and what oil did you use? Alternatively, I also have a degree in Electronic Technology with honors of the highest distinction and could take the controling circuit board out, figure out the schematic and convert the design to supply a 1KW or larger heater. However, I am not sure this HS2 DP can handle a 500 - 600 watt heater using Santovac for the next 10 years I have to work. Notes: The HS2 DP seems to be a bit too slow in pumping speed to me and might be undersized. It is not the original DP unit but looks right mechanically except for a slight roughing port mis-aligment of 1/4 " at the 4" long vac. hose outlet. The chimney is clean, aligned and assembled correctly.
Thank you in advance for any PRACTICAL experience(s) you can provide. I am trying to avoid the trial and error route.
Sincerely,
Paul Beauregard Senior Research Associate PPG Industries Monroeville Technical Center Monroeville, PA 15146 (724) 325-5131
You are correct. The process you describe does not apply to the Hitachi S-4700 FESEM.
The Hitachi S-4700 is a cold FE. The procedure you describe is for the Amray "305" gun which is normally brought to 35 KV for one hour or more. If the engineer tells you 32KV, he is probably cutiing corners.
For the Amray 305 gun: The zapping you describe is from stray molecules that have a tendency collect randomly around the gun, including the insulators. I have found that there are several "thresh-holds": voltages at which the gun arcs. These are proportional to vacuum integrity. The "thresh-holds" are at 14-15 KV, 24KV and 30KV. The 305 guns will arc then the vacuum will need to be "cleaned up" by gettering. We then start the whole conditioning process over again.
Although the indicated vacuum on the Amray CRT reads about 10e-10 Torr, the actual pressure is closer to 1x10e-8 or 8x10e-9. I have actually measured this from a calibrated hot cathode gauge.
Amray guns could use with more assistance from an additional ion pump. The existing ion pump is rated at 2 l/s. This is barely enough to "hold" the vacuum & seems to be nothing more than an "indicator" gauge. I have installed a 20 l/s ion pump on the gun and have had considerable success with less arcing, faster pump down times, better resolution, etc. It is no mistake that most other Schottky FE guns have this arrangement (LEO, Hitachi, JEOL).
Now for the Hitachi 4700 Cold FESEM questions:
} 1) Why is the "le" value decreasing with multiple flashes?
It shouldn't. Most Hitachi guns I have seen always increase with multiple flashes. I would suspect contamination or a gun problem.
} 2) How dangerous are multiple flashes to the tip?
Multiple flashes have a tendency to "blunt" or "round" the tip giving the tip less filament life but more filament stability. Hitachi actually recommends multiple flashes to condition a new tip.
} 3) Does the condition described above indicate any problem with the tip } and/or scope?
See the answer to question #1.
} 4) Is flashing actually accomplishing anything if the vacuum gauge shows no } contamination being driven off?
The first flash sould drive off any molecules at the FE tip and, therefore, give a poor, but temporary, vacuum indication. Successive flashes should affect the FE tip but will not change the vacuum.
} 5) Is it safe to keep turning up the intensity pot on the rear of the } scope? (Something tells me no.)
Define "safe" and the amount you are turning up the intensity pot. Hitachi typically has three flash intensity settings (approprately named: 1,2,3) with "3" being the most intense. I usually set "1" for 5 ua, "2" for 10 ua and "3" for 30 ua on the FIRST flash. Sucessive flashes have a tendency to increase the emission current. This is rather tricky as each filament will have a different setting. I would guess that anything over 40 & above is probably melting the FE tip and giving you poorer filament life.
} 6) Do I simply not understand what's going on? (Something tells me yes.)
Based on the depth and type of questions you ask, I think that you do know what is going on. I also would be concerned also if sucessive flashes decrease the emission current.
Summary: my guess is that there is something wrong (or going wrong) in the gun area.
What is the extraction voltages before& after all this?
DISCLAIMER: THE ABOVE ARE BASED UPON MY EXPERIENCE & ARE OF MY OPINION AND OF MY COMPANY, SCANSERVICE CORP. TO THOSE THAT WOULD CRITICIZE THE ABOVE BASED UPON A MIS-SPELLED OR MISPLACED WORD (especially from acadamia) I WOULD ONLY SAY "GET A LIFE".
Any and all CONSTRUCTIVE advice is certainly welcomed.
Regards,
Earl Weltmer
----- Original Message ----- } From: "Gary Gaugler" {gary-at-gaugler.com} To: "Tindall, Randy D." {TindallR-at-missouri.edu} Cc: "MSA listserver" {Microscopy-at-sparc5.microscopy.com} Sent: Sunday, December 09, 2001 1:56 PM
I have some samples of tungsten carbide and diamond dust in mineral oil taken from grinding machines. How do I separate these from the oil for LM and SEM and disperse them for examination? I need to get these particles into a solvent so that the particles separate. Oil makes the particles clump together. Carbides are heavy and sharp and stick to the sides of all containers so it is just too easy to get a false picture.
Many thanks. Gervais Sawyer. Forest Products Research Centre. UK.
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Although there are many excellent books on histochemical techniques for animal tissues, I have been unable to find one still in print that concentrates on plant tissue. I would appreciate any recommendations so I can add this resource to our facility mini-library.
Debby Sherman Phone: 765-494-6666 Life Science Microscopy Facility FAX: 765-494-5896 Purdue University E-mail: dsherman-at-purdue.edu S-052 Whistler Building West Lafayette, IN 47907
by sparc5.microscopy.com (8.9.3+Sun/8.9.3) id KAA16619 for dist-Microscopy; Mon, 10 Dec 2001 10:38:39 -0600 (CST) Received: from no_more_spam.com (sparc5 [206.69.208.10]) by sparc5.microscopy.com (8.9.3+Sun/8.9.3) with SMTP id KAA16615 for "MicroscopyFilteredEmail1-at-msa.microscopy.com"; Mon, 10 Dec 2001 10:38:08 -0600 (CST) by sparc5.microscopy.com (8.9.3+Sun/8.9.3) with ESMTP id KAA16608 for {Microscopy-at-sparc5.microscopy.com} ; Mon, 10 Dec 2001 10:37:57 -0600 (CST) Received: from NPGSlithography-at-aol.com by imo-m01.mx.aol.com (mail_out_v31_r1.9.) id 6.126.89d294b (3699); Mon, 10 Dec 2001 11:34:10 -0500 (EST) Message-ID: {126.89d294b.29463e01-at-aol.com}
Dear Gary,
} I ordered a 485. It should be here in two weeks. I'll re-do all } measurements } when it gets here. Any special notes I should know about when using it? } It has a BNC input jack so I'll just coax from it to my stage alarm BNC.
First, the stage alarm circuit must not be connected while using the picoammeter. If the BNC is normally connected to the alarm circuit, removing the cable to the alarm and connecting the picoammeter should be fine. The stage should have no other grounding path other than through the picoammeter.
(Note that the stage alarm will then be disabled, so it shouldn't be left this way if inexperienced users will be running the SEM.)
Ideally, the power outlet used by the picoammeter will have the same grounding as the SEM.
A good reality check is to connect the picoammeter and take a reading while the SEM is powered up, but the beam is off. With good grounding, a reading of zero will result. If a non-zero reading is measured, a quick and dirty solution is to use the "relative" mode of the Keithley 485 in order to take subsequent readings relative to the beam off baseline. This approach assumes that any leakage current being measured is a constant. Valid beam current measurements from a Faraday cup will always be displayed as negative numbers with the Keithley.
Also, note that a standard BNC cable will generate tens or hundreds of picoamps through internal friction if it is flexed or even bumped. Consequently, a relatively short BNC cable that is reasonably motionless will give the best measurements.
Finally, the Keithley 485 has a local magnetic field that is significant compared to the typical environmental specs for an SEM. Consequently, for best imaging, the 485 should be more than ~1 meter from the column. It is especially important to note that the 485 has a higher local magnetic field when the front power button is in the off position, than when the meter is turned on. Consequently, if the meter is close to the column, it must be unplugged to stop the field.
Joe _________________________________________ Joe Nabity, Ph.D. JC Nabity Lithography Systems E-Beam Lithography using Commercial SEMs & STEMs PO Box 5354, Bozeman, MT 59717 USA Voice: (406) 587-0848 FAX: (406) 586-9514 E-mail: info-at-jcnabity.com Web: www.jcnabity.com
Thanks to everyone who replied to my questions about flashing the tip in our FESEM giving us odd flashing current readings. I received some very informative and helpful replies, as always from this list.
Incidentally, I didn't put the question to the list because of any lack of helpfulness by Hitachi Instruments. I was just curious about the experiences of fellow users and what they thought about the theory behind this. We love this scope!
Happy Holidays, Randy
Randy Tindall EM Specialist Electron Microscopy Core Facility W122 Veterinary Medicine University of Missouri Columbia, MO 65211 Tel: (573) 882-8304 Fax: (573) 884-5414 Email: tindallr-at-missouri.edu Web: http://www.biotech.missouri.edu/emc/
While Jim Nicolino is says about EDS detectors acting as cold fingers can be true. However, I wish to point out that not all oil diffusion pumped are SEMs are the same as far as oiliness. For example, old Hitachi S-570s are infamous for being oily because they lacked a proper baffle above the diffusion pump mouth. I have never cleaned a S-570 without finding oil dripping from the bottom of the baffle plate at the bottom of the chamber. Hitachi S-2500 and S-2700 which updated the S-570s did not have as severe of a oil problem because of an improvement to the design.
Also contributing to the effect are choices of pump oil, heater temperature, cooling water temperature, and crossover pressure. If any of these is wrong then their will be severe backstreaming from the diffusion pump. Will Biglow's book "Vacuum Methods in Electron Microscopy" is good reference.
In modern JEOL and Hitachi SEMs that have diffusion pumps rarely does one find that it is the diffusion pump giving the problem. More common is oil backstreaming from the load locks. Many a user has replaced the diff pump with a turbo pump only to get little improvement because of the rotary oil roughing pumps, poor sample handling, and oily chambers and stages.
Notice: XEI Scientific makes products to remove oil from SEM chambers. www.SEMCLEAN.com
Ronald Vane XEI Scientific 3124 Wessex Way Redwood City, CA 94061 (650) 369-0133
-----Original Message----- } From: Jim Nicolino {JNicolino-at-fcol.com} To: Sinkler, Wharton {WSinkler-at-uop.com} Cc: 'Microscopy-at-MSA.Microscopy.Com' {Microscopy-at-sparc5.microscopy.com}
McCrone continues to sell the small set of reference pigments. Perhaps you did a search on the "McCrone Associates, Inc." page instead of on the "McCrone Microscopes and Accessories" pages.
The direct link to the page is:
http://www.mccrone.com/cgi-bin/SoftCart.exe/mac/reference/paintref.html?L+mccrone+svuu9375+1007930922 The choice of mounting medium depends on several factors related to your own work. It is often convenient to have a mounting medium with higher refractive index somewhere in the middle of the range of refractive indices of your samples. First, in many cases a rapid subdivision between pigment types can be made on the basis of whether they are above or below the r.i. of the mounting medium.
Second, pigments tend to have high refractive indices for the simple reason that, in order to function well as pigments, they must be effective at scattering light. The greater the difference in r.i. between the organic binder and the pigment, the more effective the scattering and the greater the opacity of the paint. If you chose a medium with a low r.i., the large index difference between the particles and the medium will make it more difficult to observe the optical properties and shape of very fine particles.
In general, Far Eastern art done in aqueous media makes greater use of low r.i. pigments in the form of clays, micaceous minerals and so on. So the nature of the art which you spend time on is something to consider as well.
The softening temperature of the mounting medium is a factor to consider. It is convenient to have a material which remains viscous near room temperature so that particles may be observed while rolling under the cover slip. On the other hand, if you store mounted samples for long periods, such media will cold-flow and require you to store your slide cases standing on end so that the slides remain horizontal to keep the coverslips from sliding off.
Finally, I would caution against placing too great a confidence in pigment identifications based primarily on comparison to a limited reference set. Many conservation studies suffer from erroneous pigment identifications based PLM comparison to the most similar example in a limited reference set rather than an actual identification. There is no substitute for instrumental analysis to supplement microscopy.
Disclaimer: I am not associated with McCrone A. & C. and have no interest the company.
John Twilley Art Conservation Scientist
c. yeh wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } } } } I am an art conservator working in Japan and would like to purchase a } pigment reference set and mounting medium but have been unsuccessful } in my web searches. } } I seem to recall that McCrone and Fisher sold such pigment reference } sets--with about 40 or so mounted samples of common artist pigments, } but their web pages did not turn up with any such item. } } Also, I would like to know what is the best refractive index for medium } used to mount pigments? Is is 1.55? When I was in the U.S. I used Cargille } mounting medium. } } Thank you so much for your assistance, since it is quite difficult for } me to find information on this in Japan. } } } __________________________________________________ } FREE voicemail, email, and fax...all in one place. } Sign Up Now! http://www.onebox.com } } } }
I recently acquired an AMRAY 1610T with PGT 4000 EDS. (Thanks, Melissa!)
I hope to restore it to working condition in my spare time. The manuals that were included appear to be incomplete copies. For example, the SEM manual doesn't include schematics, but the vacuum logic manual does.
Are there also service manuals for this? What might be my best route to getting a set of complete manuals?
Here's a question - can joysticks be serviced? The one that controls the stage movement on our ElectroScan E3 has been getting a little wonky lately; movement is quite jerky, especially in side-to-side motion. I'm thinking maybe there's a build-up of crud or something in there that might be causing this. There are four small Phillips-head screws that seem to hold the joystick in place on the control panel, and I wonder if we could get at the mechanism that way. Has anyone out there ever worked on their own joystick? (There's just no way to say that without it sounding kind of funny...)
F.C. Thomas MicroAnalysis Facility Geological Survey of Canada (Atlantic) Bedford Institute of Oceanography Dartmouth, Nova Scotia Canada
We have a small room for cryoesctioning and storage of a liquid nitrogen container. For the safety concern, I would like to get a oxygen sensor or alarm to monitor the oxygen level. Does anyone konw where I can get this kind of device? Any suggestion will be appreciated. Thanks in advance.
Shanling
Shanling Shi Advanced Imaging & Measurement Unilever Research US 45 River Road Edgewater, NJ 07020 201-840-2340 Shanling.Shi-at-unilever.com
This AirAware model is AC powered (Comes with an AC adaptor, no batteries to worry about.), simple to install, and has a loud alarm. The sensor is relatively inexpensive and easy to replace. We use it in our freeze fracture/cryo microtome room.
Good Luck, Jim
Disclaimer: We have no monitary interest in PriorityOne or Lab Safety Supply.
} } Hello everyone, } } We have a small room for cryoesctioning and storage of a liquid nitrogen } container. For the safety concern, I would like to get a oxygen sensor or } alarm } to monitor the oxygen level. Does anyone konw where I can get this kind of } device? Any suggestion will be appreciated. Thanks in advance. } } Shanling } } Shanling Shi } Advanced Imaging & Measurement } Unilever Research US } 45 River Road } Edgewater, NJ 07020 } 201-840-2340 } Shanling.Shi-at-unilever.com }
James S. Romanow The University of Connecticut Physiology and Neurobiology Department Electron Microscopy Facility Unit 2242 Storrs, CT 06269-2242 bsgphy3-at-uconnvm.uconn.edu 860 486-2914 voice 860 486-1936 fax
Does it have an ion pump on the gun chamber? If so, it is set up to handle LaB6, otherwise W only.
What seems to be the problem with the system at present? Is it connected and powered? Check all vacuum connections. A good option is to remove the standpipe (if ion pump is present) and replace with Lesker butterfly valve and serrated stainless steel flex pipe with KF fittings. The standard vertical stand pipe can be a a leaker.
The UVACOS vacuum board is pretty much standard for all 1000 series SEMs. The 1610T added the Balzers 240 turbo and controller. The slow scan nature of this system makes it difficult to use. I brought a 1610T to life about four years ago. I moved on to an 1830 and and now have a 1910FESEM. There is much similarity between these extremes of models.
If there are specific sections you need, I have a complete manual for AMR1000.
gary
At 10:23 AM 12/10/2001, you wrote:
} I recently acquired an AMRAY 1610T with PGT 4000 EDS. } (Thanks, Melissa!) } } I hope to restore it to working condition in my } spare time. The manuals that were included appear to } be incomplete copies. For example, the SEM manual } doesn't include schematics, but the vacuum logic } manual does. } } Are there also service manuals for this? What might } be my best route to getting a set of complete manuals? } } - John
Announcing the Seventh Annual INTERNATIONAL 11-Day Short Course on
3D Microscopy of Living Cells, June 10 - 20, 2002
Sixth, Post-course Workshop on, 3D Image Processing, June 22 - 24, 2002
Organized by Prof. James Pawley, University of Wisconsin-Madison
in association with the, UBC Brain Research Centre, Prof. Max Cynader, Director. University of British Columbia, Vancouver, BC, Canada
(CORRECTION!! some early brochures were sent out with an incorrect URL. Course info can be found at: ht tp://www.3dcourse.ubc.ca )
THE PURPOSE OF THE COURSE
Modern methods of 3D light microscopy promise a revolutionary improvement in our ability to view living cells. To help convert this promise to reality for a wider selection of biological scientists, the organizers have designed an intensive eleven-day residential course concentrating on all aspects of the 3D Microscopy of Living Cells. Sponsored by the Brain Research Centre at the University of British Columbia, it will be held in June of 2002. The course includes 4 days on 2D techniques, 5 days of 3D techniques and 2 days on 3D measurement and display. It includes everything from basic microscopy to confocal and multiphoton microscopy. A half-day Pre-course is offered for those wishing to brush up on (very!) basic optics.
Topics include: o Quantitative 2D light microscopy o 3D Imaging in confocal and widefield o Fluorescent and backscattered light signals o Digitization: The Nyquist Criterion o Poisson noise QE and S/N. o Lasers and laser tweezers o Objectives and aberration correction o Scanning-systems: AODs, mirrors, disks o Wide field/deconvolution techniques o Detectors: operation and performance o Optimal pinhole size/photon efficiency o Dye design, characteristics and use o How to keep your cells alive o Multi-photon excitation o Measuring ion concentrations o Display and measurement of 3D data
Morning lecture/demonstrations lead to hands-on laboratory exercises each afternoon utilizing most of the commercial instruments currently available for 3D microscopic imaging. Students will work in groups of 3 or 4 throughout the discussion and laboratory sessions, and may complete a live-cell 3D study on their own specimens. In the first 6 years, over 160 students from 25 countries have attended. Last year, 12 separate 3D microscopical workstations were each scheduled for over 30 hours of student use under the supervision of an international faculty of 17 who represent the state-of-the-art in live-cell microscopy. Including manufacturers representatives, the teacher/student ratio will be almost 2:1.
INTERNATIONAL FACULTY o Stephen Adams University of California-SD o Dan Axelrod University of Michigan o Mark Cannell University of Auckland o Milton Charlton University of Toronto o Ping Chin Cheng SUNY, Buffalo o Stefan Hell Max Planck Institute, Goettingen o Alan Hibbs BioCon, Melbourne, Australia o Iain Johnson Molecular Probes, OR o Larry Keenan Cell Robotics, NM o Ernst Keller Carl Zeiss, Thornwood, NY o Andres Kriete Tissue Informatics, Pittsburgh o Glen MacDonald Virginia Bloedel Hearing Inst, WA o Irina Majoul Max Planck Institute, Goettingen o Felix Margadant University of Sydney o Tim Murphy University of British Columbia o Jim Pawley University of Wisconsin-Madison o Steve Potter California Institute of Technology o Chip Shook Eppendorf Scientific,Albequerque, NM o Jim Turner Wadsworth Institute, NY o Michael Weis Agriculture Canada
TUITION Course tuition is $2,250 US and includes lunches and generous snacks. On receipt of 50% deposit, all students will receive preliminary group assignments and a copy of the textbook, Handbook of Biological Confocal Microscopy, (Plenum, 1995). The tuition fee includes the Opening Reception, the Manufacturer's Reception, and the Beach Party, and a handout binder. Accommodations and other meals are not included. The Pre-course is $100 US
APPLICATIONS Applicants will submit an application to assess knowledge level and field of interest. Enrollment will be limited to 24 - 32 participants (depending on equipment availability). Selection will be made on the basis of background and perceived need. Those with little previous LM experience will be provided with basic texts to read before the course begins, and should take the Pre-course.
Application forms and other course information from this and past years can be downloaded from the WWW site at
h ttp://www.3dcourse.ubc.ca/home.html
or obtained from:
Prof. James Pawley, Zoology Department., 1117 W. Johnson Drive, Madison, WI. Phone: 608-263-3147 fax. 608-265-5315 Email: jbpawley-at-facstaff.wisc.edu
IMPORTANT DATES Applications must be received by Mar. 15, 2002 Deposit due Apr. 15, 2002 Registration 5:00 - 7:00 pm Sunday, June 9, 2002 Intro. Lecture 7:00 PM, Sunday, June 9, 2002 Last class ends with lunch, Thursday, June 20, 2002
-- **************************************** Prof. James B. Pawley, Ph. 608-263-3147 Room 223, Zoology Research Building, FAX 608-265-5315 1117 Johnson Ave., Madison, WI, 53706 JBPAWLEY-at-FACSTAFF.WISC.EDU "A scientist is not one who can answer questions but one who can question answers." Theodore Schick Jr., Skeptical Enquirer, 21-2:39
I have a query from a collegue carrying out autoradiography of an uneven surfaced structure. She has found that standard autoradiographic plates are not suitable and is interested in using a liquid emulsion or stripping film. I have directed her towards Ilford as a source of a liquid emulsion - has anyone any other suggestion and is stripping film (Kodak AR 10) still available.
Thanks
Ian
Ian Hallett HortResearch Mt Albert Research Centre Private Bag 92 169 Auckland, New Zealand Fax 64-9-815 4201 Telephone 64-9-815 4200 EMail ihallett-at-hortresearch.co.nz
______________________________________________________ The contents of this e-mail are privileged and/or confidential to the named recipient and are not to be used by any other person and/or organisation. If you have received this e-mail in error, please notify the sender and delete all material pertaining to this e-mail. ______________________________________________________
we are using a light microscope to acquire brightfield images of diatoms, which we then want to process by computer. However, the presence of diffraction effects around the edges of the images is causing us problems.
Does anyone know of any software, preferably free, which can deconvolve an image to reduce the effects of diffraction?
thank you
Micha Bayer ______________________________
Dr. Micha Bayer Royal Botanic Garden Edinburgh 20A Inverleith Row Edinburgh EH3 5LR Scotland, U.K. Tel. (+44) (0)131-248 2915 Fax (+44) (0)131-248 2901 Project Homepage at http://www.rbge.org.uk/research/Diadist/index.htm RBGE home page at http://www.rbge.org.uk ______________________________
Oxygen monitors are pretty standard in hospital MRI centers. I have some experience with ones from Enmet. URL is http://www.enmet.com/medical.html. Sensor cells need to be replaced at least once a year, and the calibration drifts as the cells age. Although calibration kits are available, I alway just calibrated to the known O2 level in the air, at a place and time when no cryogens were present.
Dave
Shanling Shi wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } Hello everyone, } } We have a small room for cryoesctioning and storage of a liquid nitrogen } container. For the safety concern, I would like to get a oxygen sensor or alarm } to monitor the oxygen level. Does anyone konw where I can get this kind of } device? Any suggestion will be appreciated. Thanks in advance. } } Shanling } } Shanling Shi } Advanced Imaging & Measurement } Unilever Research US } 45 River Road } Edgewater, NJ 07020 } 201-840-2340 } Shanling.Shi-at-unilever.com
-- __________________________________ David J. Wilbur, Ph.D. Instrumentation Specialist Department of Chemistry Tufts University voice: 617-627-2163 Fax: 617-627-3443 email: dwilbu01-at-tufts.edu __________________________________
Does anyone have any information or opinion, positive or negative, about Q-Imaging and their Retiga 1300 cooled ccd camera? Their web site is www.qimaging.com. We would be using the camera for fluorescence imaging (with deconvolution) and bright field, dark field, DIC, phase imaging. Please feel free to contact me on or off the list.
Thanks for any info, -- _/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/_/ Jessica Wagner Molecular Cytology Core Facility University of Missouri 573-882-4895
Hello all, Does anybody out there know of a decent EM book that focuses on pathology in agricultural systems (i.e. chickens, maize and insects [as vectors])?
Cleaning out my "delete" file I have just noticed a request for a method to enable the cracking of human hair. I have been involved with this type of "problem" many times so set out below is a method which we have found works well for LM as well as SEM. We have even used the technique to investigate failures in freezer bags!
1. Drill two or three holes through two SEM stubs placed face to face. 2. Pass the fibres through the holes. 3. Fix them in place with a water based carbon solution, make sure the fibre/stub interface is well wetted. 4. When fully dry place in liquid nitrogen CARE!!. 5. When the bubbling stops lift out CARE!! 6. Place on an insulating surface and with a blade strike the interface between the two stubs - the system will fracture. 7. When dried off you have two sets of surfaces to look at in LM or SEM.
It works great on a number of differing media other than fibres, the only snag is they must not be affected by the water base.
Steve Chapman Senior Consultant Protrain For consultancy and professional training in EM world wide Tel 44+ 1280 814774 Direct Line 816512 Fax 814007 www.emcourses.com
I am posting the following for a colleague. Please respond directly to him.
Marie
**********************
Electron Microscopy Technician/Research Assistant
This is a full time position of which 70% of time will be devoted to electron microscopy research support and 30% to a combination of research support in light microscopy immunocytochemistry, cell biology and general laboratory maintenance. Percentages might be adjusted to research demands. Responsibilities include: Transmission electron microscopy (TEM) preparation, immunolabeling and TEM observation and documentation of perfused brain tissues; preparation and immunolabeling of perfused brain tissue samples for light microscopy immunocytochemistry and immunofluorescence; cell culture; preparation of buffer solutions; laboratory maintenance; supervision of laboratory ordering, receiving and record keeping, among others. Qualifications: Background in biological sciences. Candidates with experience in biological transmission electron microscopy and good communication skills are preferred. Salary commensurate with experience.
Submit curriculum vitae plus names, addresses and phone numbers of three references to:
Prof. Angel L. de Blas Dept. Physiology & Neurobiology 3107 Horsebarn Hill Rd; U-4156 Storrs, CT 06269-4156 Ph: (860) 486-3285 Fax: (860) 486-3303 e-mail: deblas-at-oracle.pnb.uconn.edu
We encourage applications from under-represented groups including minorities, women and people with disabilities.
Dr. Marie E. Cantino Dept. of Physiology and Neurobiology, U-2242 University of Connecticut Storrs, CT 06269-2242 Phone: 860-486-3588 Fax: 860-486-6369
The following position for a microscopist is being advertised in a major Australian University.
The University of New South Wales is 30 minutes to the central business district of Sydney and 10 minutes to Coogee Beach. The University of NSW is widely regarded as the premier Australian research University and encourages a vigorous research program. The University was the cradle for two major advances in electron microscopy:
1. The Robinson scintillator backscatter detector
2. The Environmental scanning electron microscope
The monetary reward may not seem generous compared with US or European salaries.
But this is compensated for by the strong local purchasing power of the Australian dollar and the benefit that a good lifestyle is much less expensive and more accessible in Sydney than in other international capitals.
Sydney is noted for its mild climate; beaches; opera house; cosmopolitan atmosphere; busy arts scene; access to aquatic sports like swimming, surfing, sailing, SCUBA diving; international standard sports facilities; quality of cuisine and value of wines; excellent educational facilities; high quality of medical care etc. Sydney is an ideal city in which to raise children.
You can learn about NSW from the State Government website
http://www.nsw.gov.au/
You can learn about Sydney from the tourism website
http://www.visitnsw.com.au/0300/0300.asp
You can learn about the University at http://www.unsw.edu.au and about the Electron Microscope Unit at http://srv.emunit.unsw.edu.au
You can direct questions to
p.munroe-at-unsw.edu.au
{bold} {color} {param} ffff,0000,0000 {/param} {bigger} Deputy Director
UNIVERSITY OF NEW SOUTH WALES
ELECTRON MICROSCOPE UNIT
REF. 1293EMAIL
{/bigger} {/color} {/bold}
The Electron Microscope Unit is a central infrastructural research facility, containing eleven principal instruments with a staff of ten. The Unit supports a very wide range of research projects from across the University and its success is based on a strong client-focused orientation. The Unit seeks a dynamic electron microscopist, ideally with a strong background in biomedical or polymer research. The successful applicant will be expected to assist the Unit's Director in the day-to-day management of the Unit, provide expertise in microscopy to a wide range of research projects in biomedical and organic materials and provide appropriate training in microscopy to the Unit's users. The Deputy Director will also develop and carry out research projects, not only related to their own interests, but also in collaboration with other academic staff within the University.
The successful applicant will also be expected to take up a fractional (20%) appointment as Lecturer or Senior Lecturer in a School relevant to their background and experience and will contribute to the teaching effort of that School and to supervise research students as appropriate.
{bold} Additional essential criteria {/bold} for appointment at Senior Lecturer level: a significant record of publication, a demonstrated track record in attracting research funding and prior experience in managing an electron microscope facility.
{bold} Essential criteria: {/bold} a PhD; proven capacity to undertake high quality research; track record of publications in internationally refereed journals; proven experience in teaching; excellent interpersonal, oral and written communication skills; very high level practical experience and theoretical ability in electron microscopy; ability to implement OHS principles and equity and diversity policies and programs.
Desirable criteria: track record in attracting research funding; experience in management of a research laboratory.
{bold} The salary range {/bold} will be commensurate with Lecturer A$52,173 - A$61,957 per year or Senior Lecturer is A$63,912 - A$73,695 per year depending on qualifications and experience.
Membership of a University approved superannuation scheme is a condition of employment.
Enquiries may be directed to Electron Microscope Unit Director, Associate Professor Paul Munroe, on telephone (61 2) 9385 4435, facsimile (61 2) 9385 6400 or email p.munroe-at-unsw.edu.au.
Applications close 7 February 2002.
APPLICATION PROCEDURE
Applicants should submit written applications systematically addressing the selection
criteria, QUOTING REFERENCE NUMBER. Include business and private telephone numbers; a complete resume, (copies of academic transcript and qualifications where appropriate); and the names, addresses (and preferably email addresses or facsimile numbers) of at least two referees to: The Recruitment Officer, Human Resources, UNSW Sydney 2052, email: recruitment-at-unsw.edu.au or facsimile (61 2) 9662 2832 by applications close date.
www.unsw.edu.au
Dr. Mel Dickson,
Deputy Director, The Electron Microscope Unit,
Adjunct Associate Professor, School of Microbiology & Immunology
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How are they mounted? I have no experience with diatoms, but for what it's worth, what about minimizing the refraction BEFORE the light gets to the computer? I mean if the diatoms are in water you may be able to increase the refractive index of the medium you are using (by adding dextran, polyvinyl alcohol, etc) to nearly match that of the specimen, so that the object's refraction is less of a problem.
OptiPrep (TM) (aka iodixanol) is miscible with water and has a very high refractive index, 1.40 for a 40% solution, which is near the R.I. of silica. Another contrast medium, Omnipaque (TM) (iohexol) is lower in R.I. but may be less expensive.
I would guess that this approach would even improve deconvolved images of diatoms in water. Does anyone have experience with this?
Richard
Richard Thrift, PhD
(858) 625-2424 Richard_Thrift-at-SkyePharma.com SkyePharma, Inc 10450 Science Center Drive San Diego, CA, 92121 USA
we are using a light microscope to acquire brightfield images of diatoms, which we then want to process by computer. However, the presence of diffraction effects around the edges of the images is causing us problems.
Does anyone know of any software, preferably free, which can deconvolve an image to reduce the effects of diffraction?
thank you
Micha Bayer ______________________________
Dr. Micha Bayer Royal Botanic Garden Edinburgh 20A Inverleith Row Edinburgh EH3 5LR Scotland, U.K. Tel. (+44) (0)131-248 2915 Fax (+44) (0)131-248 2901 Project Homepage at http://www.rbge.org.uk/research/Diadist/index.htm RBGE home page at http://www.rbge.org.uk ______________________________
With the advent of digital cameras that can be hooked into either eye piece of a stereo microscope, the collection of stereo pairs seems very simple. And with inkjet printers and programs like Adobe Photoshop we now have a great deal of freedom. Has anyone found any simple solutions for printing and presenting the stereo pairs?
I have never worked with diatoms and have never experienced the problem you describe. I have however worked with image processing and analysis. One thing that experience has taught me is that it is best to present as 'good' or 'pure' an image as possible to the computer rather than use the software to 'clean it up'. Such processing will change your image/data in some way which may be undesirable (depends what you are doing).
Could you suspend them in something else? Use a different optical setup?
I would be interested to know if you find an answer.
Good luck.
Nadolig Llawen a Blwddyn Newydd Dda / God Jul och Gott Nytt År / Merry Christmas and a Happy New Year
Gareth Morgan MPhil MSc FIBMS, Institutionen för Mikrobiologi, Patologi och Immunologi(IMPI), H5, Karolinska Institutet, Dept of Biomedical Laboratory Science, Lindhagensgatan 92, Box 12773, S 112 96, Stockholm Sweden
I tried to reply directly to you but it bounced for some reason, so this time I'm sending to the whole list, assuming you'll see it this way. (If anyone else is having problems with a wonky joystick, read on to learn what's fixed mine.)
Frank Thomas GSC Atlantic
----- Original Message ----- } From: "Frank Thomas" {thomasf-at-agc.bio.ns.ca} To: "Monson, Frederick C." {fmonson-at-wcupa.edu} Sent: Tuesday, December 11, 2001 3:07 PM
Hello Micha, I would agree that index matching your mounting media to the refractive index of silica should alleviate the diffraction problems you describe. One important concern is the method by which you are introducing contrast into the specimen for visualization. When the refractive indices are matched, the diatoms will be invisible under standard brightfield illumination. Phase contrast and Nomarski DIC depend on the changes in refractive index at boundries between areas of differing RI to enhance contrast. I have no experience with imaging diatoms, but I seem to recall that darkfield illumination is a popular way to image diatoms, although this method is also dependant on at least a slight mismatch in the refractive index of the specimen and mountant. You might be able to get away with a very close match, however. The numerical aperture of the lens you are using to image the diatoms should be as large as possible. I'm not sure how big your diatoms are, but using a higher numerical aperture objective (preferably oil immersion) may help. If your diatoms are small enough to approach the diffraction-limited resolution limit of the objective lens you are using switch to a higher power or better quality objective (if you have that option). Good luck! -Karl G.
At 12:00 PM 12/11/2001 +0100, Micha Bayer wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
_______________________________________________ Karl Garsha Specialist in Light Microscopy Beckman Institute for Advanced Science and Technology 405 North Mathews Avenue Urbana, IL 61801 Room B650J Tel: (217) 244-6292 Fax: (217) 244-6219 www.itg.uiuc.edu
I just wanted to point you to our analySIS software and the Stereo module. You can take a stereo pair, and display that anaglyphically (red and green), and with the correct glasses you see a 3D image (you can of course also print that). Alternatively, you can have the software calculate the 3D surface of the Object from the stereo pair and then display your object in 3D on the computer. The software was initially written for stereo imaging on an SEM, but there is no reason it should not work on images from a stereo microscope.
mike
Michael Bode, Ph.D. Soft Imaging System Corp. 1675 Carr St., #105N Lakewood, CO 80215 =================================== phone: (888) FIND SIS (303) 234-9270 fax: (303) 234-9271 email: mailto:info-at-soft-imaging.com web: http://www.soft-imaging.com ===================================
-----Original Message----- } From: Smartech [mailto:smartech-at-optonline.net] Sent: Tuesday, December 11, 2001 9:14 PM To: To all on the list
With the advent of digital cameras that can be hooked into either eye piece of a stereo microscope, the collection of stereo pairs seems very simple. And with inkjet printers and programs like Adobe Photoshop we now have a great deal of freedom. Has anyone found any simple solutions for printing and presenting the stereo pairs?
In a message dated 12/12/01 10:24:00 AM, mb-at-Soft-Imaging.com writes:
} I just wanted to point you to our analySIS software and the Stereo module. } You can take a stereo pair, and display that anaglyphically (red and green), } and with the correct glasses you see a 3D image (you can of course also } print that). Alternatively, you can have the software calculate the 3D } surface of the Object from the stereo pair and then display your object } in 3D on the computer. The software was initially written for stereo imaging } on an SEM, but there is no reason it should not work on images from a stereo } microscope.
Since you originally asked about Photoshop, I'd like to point out that combining two images as an anaglyph is straightforward using the Photoshop channels command (put the left image into the red channel, the right one into the blue and green). And for measuring the parallax and generating a height map or reconstructed 3D image of the surface you can use the Image Processing Tool Kit plug-ins for Photoshop. One of the examples on the web site (see http://www.ReindeerGraphics.com/foveapro2/surface.html) in fact uses images of a small fossil captured through a stereo microscope using an inexpensive Nikon digital camera.
The backstreaming of oil from diffusion pump systems into the specimen chambers of electron microscopes has been a problem that has been around for a long time, and one that is very hard to eliminate. This was a matter that I addressed as fully as I could while writing my book on 'Vacuum Methods in Electron Microscopy' (see http://www.2spi.com/catalog/books/book48.html and http://www.pup.princeton.edu/titles/6484.html for a description). Dealing with backstreaming from rotary vane pumps is described on pages 144 to 150, and from oil diffusion pumps on pages 190 to 200. Perhaps some of the information presented there would be of help. -- Wilbur C. Bigelow, Prof. Emeritus Materials Sci. & Engr., University of Michigan 3062 Dow Bldg.; 2300 Hayward St. Ann Arbor, MI 48109-2136 e-mail: bigelow-at-umich.edu; Fx:734-763-4788; Ph:734-662-5237
Hello, I was going to volunteer to give a 60 minute science demonstration to students at local grade schools and was looking for ideas for projects. I came up with some things such as having the students look at organisms in pond water in light microscopes, maybe some SEM photos of common insects (which may not be hands on enough to interest the kids), or teaching them how to pan for gold. The idea is to capture the interest of students and encourage them to study science.
Could you forward any ideas you may have? Thanks, Gordon
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ Gordon Ante Vrdoljak Electron Microscope Lab ICQ 23243541 http://nature.berkeley.edu/~gvrdolja 26 Giannini Hall gvrdolja-at-nature.berkeley.edu UC Berkeley phone (510) 642-2085 Berkeley CA 94720-3330 fax (510) 643-6207 cell (510) 290-6793
Çan anyone direct me to a manufacturer of 2-chamber coverslips for cell culture that use #1.5 thickness coverslips? So far, I'm only finding #1 thickness.
Thanks, Glen
-- Glen MacDonald Microscopy and Imaging Facility University of Washington Core for Communication Research Virginia Merrill Bloedel Hearing Research Center Box 357923 University of Washington Seattle, WA 98195-7923 glenmac-at-u.washington.edu (206) 616-4156 (206) 616-1828 fax ************************************************************************** C:} The box said "Requires Windows95 or better". So I bought a Macintosh. **************************************************************************
We're looking for a 100X planapo oil lens (NA = 1.4) for a Nikon Diaphot TMD, tube length 160 mm. If anyone has one in excellent condition to sell, please let me know. Vendor replies welcome. Phil -- Philip Oshel Supervisor, AMFSC and BBPIC microscopy facilities Department of Animal Sciences University of Wisconsin 1675 Observatory Drive Madison, WI 53706 - 1284 voice: (608) 263-4162 fax: (608) 262-5157 (dept. fax)
I guarantee that they won't match! Without a bit of directed effort, at least, and if they do happen to match, it is easily fixed by adjusting the concentration of polymer.
With just a tiny bit of mismatch between sample & medium, the sample can be imaged easily by tweaking the contrast on the camera, even if it is not so easily seen by eye.
Another trick which works for latex beads & may work for silica is to add a bit of Nile Red to the suspension. The dye will stick to the surface & fluoresce, while it is almost nonfluorescent in water.
Richard
} } } James Pawley {jbpawley-at-facstaff.wisc.edu} 12/12/01 10:08:29 AM } } } Problem is that when the RI finally does match, bright field contrast disappears.
Jim P. } ------------------------------------------------------------------------ } How are they mounted? I have no experience with diatoms, but for } what it's worth, what about minimizing the refraction BEFORE the } light gets to the computer? I mean if the diatoms are in water you } may be able to increase the refractive index of the medium you are } using (by adding dextran, polyvinyl alcohol, etc) to nearly match } that of the specimen, so that the object's refraction is less of a } problem. } } OptiPrep (TM) (aka iodixanol) is miscible with water and has a very } high refractive index, 1.40 for a 40% solution, which is near the } R.I. of silica. Another contrast medium, Omnipaque (TM) (iohexol) is } lower in R.I. but may be less expensive. } } I would guess that this approach would even improve deconvolved } images of diatoms in water. Does anyone have experience with this? } } Richard } } Richard Thrift, PhD } } (858) 625-2424 Richard_Thrift-at-SkyePharma.com } SkyePharma, Inc } 10450 Science Center Drive } San Diego, CA, 92121 USA } } } } } "Micha Bayer" {M.Bayer-at-rbge.org.uk} 12/11/01 12:00:20 PM } } } } Hi, } } we are using a light microscope to acquire brightfield images of } diatoms, which we then want to process by computer. However, the } presence of diffraction effects around the edges of the images is } causing us problems. } } Does anyone know of any software, preferably free, which can } deconvolve an image to reduce the effects of diffraction? } } thank you } } Micha Bayer } ______________________________ } } Dr. Micha Bayer } Royal Botanic Garden Edinburgh } 20A Inverleith Row } Edinburgh EH3 5LR } Scotland, U.K. } Tel. (+44) (0)131-248 2915 } Fax (+44) (0)131-248 2901 } Project Homepage at http://www.rbge.org.uk/research/Diadist/index.htm } RBGE home page at http://www.rbge.org.uk } ______________________________
-- **************************************** Prof. James B. Pawley, Ph. 608-263-3147 Room 223, Zoology Research Building, FAX 608-265-5315 1117 Johnson Ave., Madison, WI, 53706 JBPAWLEY-at-FACSTAFF.WISC.EDU "A scientist is not one who can answer questions but one who can question answers." Theodore Schick Jr., Skeptical Enquirer, 21-2:39
Gordon - Try liquid nitrogen experiments. These are always a hit with kids although a but risky so caution is advised. You could freeze and break rubber bands, shatter a rose, inflate a balloon with LN gas boil off (use a plastic soda bottle) then deflate it by placing back into LN. There are lots of other ideas as well but this can get you started. Good luck.
Dave
On Wed, 12 Dec 2001, Gordon Vrololjak wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } } Hello, } I was going to volunteer to give a 60 minute science demonstration to } students at local grade schools and was looking for ideas for projects. I } came up with some things such as having the students look at organisms in } pond water in light microscopes, maybe some SEM photos of common insects } (which may not be hands on enough to interest the kids), or teaching them } how to pan for gold. The idea is to capture the interest of students and } encourage them to study science. } } Could you forward any ideas you may have? } Thanks, } Gordon } } \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ } Gordon Ante Vrdoljak Electron Microscope Lab } ICQ 23243541 http://nature.berkeley.edu/~gvrdolja 26 Giannini Hall } gvrdolja-at-nature.berkeley.edu UC Berkeley } phone (510) 642-2085 Berkeley CA 94720-3330 } fax (510) 643-6207 cell (510) 290-6793 } } }
I am looking for anyone with experience looking at coccolithophorids using TEM.
We need to look at sections. The guys are only about 5 um in diameter. I have done some thin layer embedding and individual cell selection before, but never on anything this small. I will be checking other sources of information about techniques, but thought I would ask here too,
Any hints or tips on fixing, embedding, etc. that might help?
Thanks
Jonathan Krupp Microscopy & Imaging Lab University of California Santa Cruz, CA 95064 (831) 459-2477 jmkrupp-at-cats.ucsc.edu
Dear List, dear Jon, In our lab people from the institute of crystallograhpy investigated coccoliths using TEM. They just used "powders" in plane view. If there is any method to prepare these algae so that the algae or the coccoliths can be sectioned and investigated individually I would be very glad to receive this inforamtion, too. Thank you very much. Gerhard Frank
Jon Krupp schrieb: } } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } Season's Greetings: } } I am looking for anyone with experience looking at coccolithophorids using TEM. } } We need to look at sections. The guys are only about 5 um in diameter. I } have done some thin layer embedding and individual cell selection before, } but never on anything this small. I will be checking other sources of } information about techniques, but thought I would ask here too, } } Any hints or tips on fixing, embedding, etc. that might help? } } Thanks } } Jonathan Krupp } Microscopy & Imaging Lab } University of California } Santa Cruz, CA 95064 } (831) 459-2477 } jmkrupp-at-cats.ucsc.edu
-- Gerhard Frank Central Facility for High Resolution Electron Microscopy UNIVERSITAET ERLANGEN-NUERNBERG Institut fuer Werkstoffwissenschaften VII Cauerstr. 6, D-91058 Erlangen, Germany Gerhard.Frank-at-ww.uni.erlangen.de
Caroline Schooley has assembled several microscopy based school activities on the Project Micro web page ( http://www.msa.microscopy.com/ProjectMicro/ClassroomActivities.html). The one I am familiar with, The Beanie Baby Mystery, is easy to do with a few stereomicroscopes or magnifying glasses. It can take 30-45 minutes depending on the size of the class and the story can be changed for the age of the students.
Joe Neilly Abbott Laboratories D-45M, AP31 200 Abbott Park Rd. Abbott Park, IL 60064-6202
Gordon Vrololjak {gvrdolja-at-nature.Ber To: microscopy-at-sparc5.microscopy.com keley.EDU} cc: Subject: demonstration for K-6th grade students 12/12/01 12:13 PM
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Hello, I was going to volunteer to give a 60 minute science demonstration to students at local grade schools and was looking for ideas for projects. I came up with some things such as having the students look at organisms in pond water in light microscopes, maybe some SEM photos of common insects (which may not be hands on enough to interest the kids), or teaching them how to pan for gold. The idea is to capture the interest of students and encourage them to study science.
Could you forward any ideas you may have? Thanks, Gordon
\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\ Gordon Ante Vrdoljak Electron Microscope Lab ICQ 23243541 http://nature.berkeley.edu/~gvrdolja 26 Giannini Hall gvrdolja-at-nature.berkeley.edu UC Berkeley phone (510) 642-2085 Berkeley CA 94720-3330 fax (510) 643-6207 cell (510) 290-6793
Nalge Nunc, their Lab Tek II chambered coverglass. They also make 1, 4, and 8 well coverslips with 1.5 thickness coverglasses. I don't have a phone number or URL, as our dealings are with the local distributor. Phil
} Çan anyone direct me to a manufacturer of 2-chamber coverslips for cell } culture that use #1.5 thickness coverslips? So far, I'm only } finding #1 thickness. } } Thanks, } Glen } } -- } Glen MacDonald } Microscopy and Imaging Facility } University of Washington Core for Communication Research } Virginia Merrill Bloedel Hearing Research Center } Box 357923 } University of Washington } Seattle, WA 98195-7923 } glenmac-at-u.washington.edu } (206) 616-4156 (206) 616-1828 fax } ************************************************************************** } C:} The box said "Requires Windows95 or better". So I bought a Macintosh. } **************************************************************************
-- Philip Oshel Supervisor, AMFSC and BBPIC microscopy facilities Department of Animal Sciences University of Wisconsin 1675 Observatory Drive Madison, WI 53706 - 1284 voice: (608) 263-4162 fax: (608) 262-5157 (dept. fax)
General preparation methods for light microscopy and SEM examination of coccolithophorids are nicely summarized on pages 330-331 of "Plankton Stratigraphy" Bolli, Saunders and Perch-Neilsen (Editors), 1985, Cambridge University Press. They don't, however, say anything about sectioning them. For biostratigraphy, where it's important to know exactly what species you're dealing with, you normally want the little guys as whole as possible, and id's are made on the basis of (mostly) morphology. I bet your local Earth Sciences library has this book, anyway. Are you at liberty to say why you're interested in sectioning them?
Frank Thomas Geological Survey of Canada (Atlantic) Bedford Institute of Oceanography Dartmouth, Nova Scotia
----- Original Message ----- } From: "Jon Krupp" {jmkrupp-at-cats.ucsc.edu} To: {Microscopy-at-sparc5.microscopy.com} Sent: Wednesday, December 12, 2001 6:20 PM
Calling All Microscopists,
We have often removed sputtered gold from SEM specimens with a solution of potassium iodide / iodine complex. However, I've forgotten the quantitative formulation. Does anyone know how much of KI and of I2 to use?
+-----------------------------------------+ Robert H.Olley J.J.Thomson Physical Laboratory University of Reading Whiteknights Reading RG6 6AF England +-----------------------------------------+ Phone: {direct line +44 (0) 118 9318572 {University internal extension 7867 Fax: +44 (0) 118 9750203 Email: R.H.Olley-at-reading.ac.uk URL: http://www.reading.ac.uk/~spsolley +-----------------------------------------+
I would like to direct you to a wonderful program called "Project MICRO" (details can be found on the MSA website): http://www.msa.microscopy.com/Project Micro
Basically it is a program to introduce microscopic explorations to elementary and junior high school students. I am a member and corresponding secretary of MSA's local affiliate, New England Society for Microscopy, and our group has wholeheartedly embraced Project MICRO. We actually raised money and put together three kits (inlcudes all the materials, dissecting and simple monocular microscopes). Several members have used the program in their local schools. We even had a workshop at our annual Woods Hole Meeting (Woods Hole, MA) a few years back to encourage members to get involved. I am hoping to run a Saturday Workshop at a local school sometime in January.
The program utilizes a workbook "Microscopic Explorations"-a GEMS Festival Teacher's Guide, which was put together at the Lawrence Hall of Science at the University of California at Berkeley.
It sounds like a good program for you. You could get a kit and run a workshop with teachers in a local school. Students and teachers are overwhelmingly supportive.
Take a look......
Peggy Sherwood
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-- Peggy Sherwood Lab Associate, Photopathology Wellman Laboratories of Photomedicine (W224) Massachusetts General Hospital 50 Blossom Street Boston, MA 02114 617-724-4839 (voice mail) 617-726-6983 (lab) 617-726-3192 (fax) sherwood-at-helix.mgh.harvard.edu
At 08:34 AM 12/13/2001 -0600, you wrote: } Microscopy-at-sparc5.microscopy.com
Thomas Moninger (thomas-moninger-at-uiowa.edu) University of Iowa Central Microscopy Research Facility (www.uiowa.edu/~cemrf) View expressed are my own.
I am currently working on an EDS analysis project on carbon / fluorine matrices. Usually carbon starts as the taller peak, and remains so throughout the acquisition. Occasionally, however, when starting an spectrum acquisition I will see the fluorine peak start as the taller peak, then slow to become the shorter peak.
I was told by an observer that there is a phenomenon known as "chemical shift," that could have an impact on the amount of certain elements in the interaction volume of a sample. This person didn't know much about it other than it could give you inaccurate quant results.
Is there such a thing as chemical shift, and if so, could someone explain what exactly is happening during the process?
This sounds like a problem with terminology. I would not call it chemical shift but probably would call it devolatilization.
When someone says "chemical shift", I usually think of a shift in the energy or wavelength of the x-ray lines due to the chemical environment of an atom. For example, sulfur as sulfide, as sulfate, and as thiol each have slightly different peak energies. That is something that can be observed and can be a problem with wavelength dispersive analysis. However, the resolution is not so good to be able to observe such a shift, unless you have one of the new microcalorimeter detectors.
I might also consider a shift of intensity between peaks as a chemical shift. I remember seeing a paper about the L-lines of nickel. Depending on the amount of alloying element (Al, I think), the relative intensity of the L-lines changed dramatically. The explanation was that the electronic environment changed so that different transitions giving rise to L-lines were more favorable as there was more or less of the alloying element. This is quite visible by EDS, but not that common.
I sincerely doubt that you are seeing either of these effects.
What you are probably seeing is a change in chemical composition with continued exposure to the electron beam. That does lead to a shift in the chemical composition, but I reserve the phrase chemical shift for what I explained above. You are either preferentially volatilizing one component compared to another, or you are changing the components through heating. This is not uncommon, particularly at higher currents and voltages.
You might try a number of things to reduce the energy dumped into your sample. You might try dropping your beam current. If you are doing SEM, you might also reduce the voltage. You might try spreading a beam over an area (or larger area) rather than using a point analysis so that the energy is spread out. (This presumes your sample is homogeneous.)
You might also try a much shorter exposure, or successive exposures to try to capture the initial composition. I know our Tracor Northern TN-2000 had a feature for painting a window for an element and plotting the intensity of that window over time - you picked the time interval per channel. However, I don't think that feature has been on any of our last three EDS systems. It would be really helpful for what you are facing. There are probably ways to fake your way through with what you do have. \
I hope this helps. Warren
At 12:24 PM 12/13/01 -0600, you wrote:
} I am currently working on an EDS analysis project on carbon / fluorine } matrices. Usually carbon starts as the taller peak, and remains so } throughout the acquisition. Occasionally, however, when starting an } spectrum acquisition I will see the fluorine peak start as the taller peak, } then slow to become the shorter peak. } } I was told by an observer that there is a phenomenon known as "chemical } shift," that could have an impact on the amount of certain elements in the } interaction volume of a sample. This person didn't know much about it other } than it could give you inaccurate quant results. } } Is there such a thing as chemical shift, and if so, could someone explain } what exactly is happening during the process? } } Thanks, } } } Jeff Oakley } Rayovac Corporation
------------------------------------------- No files should be attached to this message ------------------------------------------- Warren E. Straszheim Materials Analysis and Research Lab Iowa State University 23 Town Engineering Ames IA, 50011-3232
I am looking for help finding staining chemistries or procedures, which may be used to enhance imaging of GaN based material layers. Any information you could pass along would be helpful.
Robert H.Olley wrote: =============================================================
We have often removed sputtered gold from SEM specimens with a solution of potassium iodide / iodine complex. However, I've forgotten the quantitative formulation. Does anyone know how much of KI and of I2 to use? =============================================================== I know it goes against conventional wisdom, but in the past we have been able to remove the sputtered gold layer using an oxygen plasma in one of our Plasma Prep II plasma etchers. I have never had anyone explain to me why it would do this but it apparently does. A typical gold thickness would come off in about thirty or so minutes. We made this discovery when trying to come up with a good demonstration of the effect of etching as a function of time on some ordinary clay coated paper. To etch a little more we had to first etch off the applied gold layer for the previous step. This was done some years ago before the days or the more modern techniques that often times require no coating at all. We have the results from that study on a sign we use in our exhibit stands but don't have it yet on our website. If you would like to see the results, ask me when ever you see SPI at a trade show exhibition. I usually have it with me on display.
For some samples, the liquid method would change the sample and that would certainly be the case for paper.
Chuck
PS: Please remember that we are nearly 100% paperless and we would ask that any reply to this message be by way of the "reply" feature on your software, so that the entire string of correspondence can come back to us and all be in one place.
=================================================== Charles A. Garber, Ph. D. Ph: 1-(610)-436-5400 President 1-(800)-2424-SPI SPI SUPPLIES FAX: 1-(610)-436-5755 PO BOX 656 e-mail: cgarber-at-2spi.com West Chester, PA 19381-0656 USA Cust. Service: spi2spi-at-2spi.com
Look for us! ############################ WWW: http://www.2spi.com ############################ ==================================================
It's also possible that carbon is increasing during the analysis due to hydrocarbon contamination of the sample or microscope, a common situation in e-beam analysis. You might try monitoring the count rates for the C and F x-rays to see whether the carbon is increasing or fluorine is being lost.
Larry Thomas Pacific Northwest National Laboratory P.O. Box 999 Mail Stop P8-16 Richland, WA, USA
---------- From: Warren E Straszheim Sent: Thursday, December 13, 2001 12:11 PM To: Oakley, Jeff Cc: Microscopy-at-sparc5.microscopy.com Subject: Re: EDS analysis / "Chemical shift"
------------------------------------------------------------------------ The Microscopy ListServer -- Sponsor: The Microscopy Society of America To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html
This sounds like a problem with terminology. I would not call it chemical shift but probably would call it devolatilization.
When someone says "chemical shift", I usually think of a shift in the energy or wavelength of the x-ray lines due to the chemical environment of an atom. For example, sulfur as sulfide, as sulfate, and as thiol each have slightly different peak energies. That is something that can be observed and can be a problem with wavelength dispersive analysis. However, the resolution is not so good to be able to observe such a shift, unless you have one of the new microcalorimeter detectors.
I might also consider a shift of intensity between peaks as a chemical shift. I remember seeing a paper about the L-lines of nickel. Depending on the amount of alloying element (Al, I think), the relative intensity of the L-lines changed dramatically. The explanation was that the electronic environment changed so that different transitions giving rise to L-lines were more favorable as there was more or less of the alloying element. This is quite visible by EDS, but not that common.
I sincerely doubt that you are seeing either of these effects.
What you are probably seeing is a change in chemical composition with continued exposure to the electron beam. That does lead to a shift in the chemical composition, but I reserve the phrase chemical shift for what I explained above. You are either preferentially volatilizing one component compared to another, or you are changing the components through heating. This is not uncommon, particularly at higher currents and voltages.
You might try a number of things to reduce the energy dumped into your sample. You might try dropping your beam current. If you are doing SEM, you might also reduce the voltage. You might try spreading a beam over an area (or larger area) rather than using a point analysis so that the energy is spread out. (This presumes your sample is homogeneous.)
You might also try a much shorter exposure, or successive exposures to try to capture the initial composition. I know our Tracor Northern TN-2000 had a feature for painting a window for an element and plotting the intensity of that window over time - you picked the time interval per channel.
However, I don't think that feature has been on any of our last three EDS systems. It would be really helpful for what you are facing. There are probably ways to fake your way through with what you do have. \
I hope this helps. Warren
At 12:24 PM 12/13/01 -0600, you wrote:
} I am currently working on an EDS analysis project on carbon / fluorine } matrices. Usually carbon starts as the taller peak, and remains so } throughout the acquisition. Occasionally, however, when starting an } spectrum acquisition I will see the fluorine peak start as the taller peak, } then slow to become the shorter peak. } } I was told by an observer that there is a phenomenon known as "chemical } shift," that could have an impact on the amount of certain elements in the } interaction volume of a sample. This person didn't know much about it other } than it could give you inaccurate quant results. } } Is there such a thing as chemical shift, and if so, could someone explain } what exactly is happening during the process? } } Thanks, } } } Jeff Oakley } Rayovac Corporation
------------------------------------------- No files should be attached to this message ------------------------------------------- Warren E. Straszheim Materials Analysis and Research Lab Iowa State University 23 Town Engineering Ames IA, 50011-3232
Does anyone know of an antifade agent that works for liver-cell microscopy systems? We're having trouble with fading of the fluorescent signal. Thanks in advance.
Mary
Mary McKee MGH Renal Unit Charlestown, MA 02129 (617)726-3696
I am working ICs which have an upper and lower TiW barrier metal layer between AlSi. The problem is that the huge extreme of Z makes SE and BSE imaging big time difficult. I tried moderating the range using Au/Pd (60/40%) but it makes little difference. This coating was about 40A thick.
Does anyone have a suggestion about how to normalize the Z range of materials in this type of specimen so that either SE or BSE images would show reasonable contrast? If anyone would like to see my pathetic images at this time, I can put them on one of my web sites.
Here are the killer (Z values): Al=13 Si=14 Ti=22 W=74 (low % but huge impact on image contrast)
I have thought about Silver (Z47) and Zirconium (Z40) to try to even out the overall Z range of the specimen. Unfortunately, Anatech does not make Zirconium targets for the Hummer VII. I have available Au, Pd, Pt, silver, or air.
Am I at the limits of this coater and its target materials?
Our ion mill has developed a vacuum problem. After checking and servicing various components including replacing the whisperlock with the blanking tool, we have narrowed down the possible defect to be with the vac valve (airlock evacuation valve) on the right mill. The vacuum deteriorates significantly when the right mill vac button is depressed and remains at the poor vac continuously. This is irrespective of whether the whisperlock or the blanking tool is installed . Among the spares, we have spare o-rings for the vac and vent valves, but we do not have any information regarding how these are to be greased / replaced or for the valve to be serviced. No apparent screws / nuts / washers etc are found. Any information regarding the servicing of these parts will be greatly appreciated since we do not have a service contract on the instrument. Our instrument is nearly 10 years old and we have been maintaining it ourselves for most part of the period.
With Thanks and Best wishes to all list members, ---- Divakar R Physical Metallurgy Section, Indira Gandhi Centre for Atomic Research Kalpakkam 603102, India ----
I wish you had said more about the materials you are looking at. The electron beam causes considerable heating in a sample, and if there is free fluorine in the sample, not chemically bonded, then the action of this heating and the vacuum could cause migration of the fluorine. As mentioned by another poster, 'chemical shift' in x-ray spectroscopy refers to the actual shifts in peak locations caused by chemical bonds altering the quantum energy levels of the electron shells. This effect will only be seen on fully focusing Johannson wavelength spectrometers or the more recent microcalorimeter systems, developed at NIST.
One other possibility is an instrumental problem. Problems in the DAC circuitry of an EDS can result in odd effects, particularily at the low end. Normally, something like this would be heat related and probably show up as the instrument is first warming up. Is it possible that the high fluorine peaks that slowly decrease are found primarily on the first spe ctrum or two in a run of samples?
Allen R. Sampson Advanced Research Systems 317 North 4th. Street St. Charles, Illinois 60174
-----Original Message----- } From: Oakley, Jeff [SMTP:oakleyj-at-rayovac.com] Sent: Thursday, December 13, 2001 10:25 AM To: 'Microscopy-at-MSA.Microscopy.Com'
I am currently working on an EDS analysis project on carbon / fluorine matrices. Usually carbon starts as the taller peak, and remains so throughout the acquisition. Occasionally, however, when starting an spectrum acquisition I will see the fluorine peak start as the taller peak, then slow to become the shorter peak.
I was told by an observer that there is a phenomenon known as "chemical shift," that could have an impact on the amount of certain elements in the interaction volume of a sample. This person didn't know much about it other than it could give you inaccurate quant results.
Is there such a thing as chemical shift, and if so, could someone explain what exactly is happening during the process?
Gary, You should have a gamma function that will allow non-linear amplification on your AMRAY. Have you tried that?
Ken Converse owner Quality Images third party SEM service Delta, PA
Gary Gaugler wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of } America To Subscribe/Unsubscribe -- Send Email to } ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } } hello listers: } } I am working ICs which have an upper and lower } TiW barrier metal layer between AlSi. The problem is } that the huge extreme of Z makes SE and BSE imaging } big time difficult. I tried moderating the range using } Au/Pd (60/40%) but it makes little difference. This } coating was about 40A thick. } } Does anyone have a suggestion about how to normalize } the Z range of materials in this type of specimen so that } either SE or BSE images would show reasonable contrast? } If anyone would like to see my pathetic images at this time, } I can put them on one of my web sites. } } Here are the killer (Z values): } Al=13 } Si=14 } Ti=22 } W=74 (low % but huge impact on image contrast) } } I have thought about Silver (Z47) and Zirconium (Z40) } to try to even out the overall Z range of the specimen. } Unfortunately, Anatech does not make Zirconium } targets for the Hummer VII. I have available Au, Pd, Pt, silver, or } air. } } Am I at the limits of this coater and its target materials? } } TIA, } gary g. } } } }
Sounds like gamma filtering would help you. If you have that option on your SEM, give it a try.
Diane Ciaburi
Gary Gaugler {gary-at-gaugler.com} 12/14/01 12:10 AM
To: MSA listserver {Microscopy-at-sparc5.microscopy.com} cc: Subject: IC cross sections -- with high Z contrast
hello listers:
I am working ICs which have an upper and lower TiW barrier metal layer between AlSi. The problem is that the huge extreme of Z makes SE and BSE imaging big time difficult. I tried moderating the range using Au/Pd (60/40%) but it makes little difference. This coating was about 40A thick.
Does anyone have a suggestion about how to normalize the Z range of materials in this type of specimen so that either SE or BSE images would show reasonable contrast? If anyone would like to see my pathetic images at this time, I can put them on one of my web sites.
Here are the killer (Z values): Al=13 Si=14 Ti=22 W=74 (low % but huge impact on image contrast)
I have thought about Silver (Z47) and Zirconium (Z40) to try to even out the overall Z range of the specimen. Unfortunately, Anatech does not make Zirconium targets for the Hummer VII. I have available Au, Pd, Pt, silver, or air.
Am I at the limits of this coater and its target materials?
Unfortunately, application of a coating will not solve your problem. The only effect will be to reduce sensitivity to changes in Z under the coating. The same effect could be had by just reducing the gain/contrast control. The Z ratio remains the same under the coating. If the contrast/gain is increased to compensate for the sensitivity loss generated by an applied coating, you will be back where you started, but with a degraded signal to noise ratio. I have graphics of this effect in my homegrown "SEM Primer" booklet.
The problem is common for me. Sometimes I want to see very small Z changes when the overall range is huge. You ought to try heterogeneous mixes/compounds like C, O, Al, and U!!!
To my knowledge, there is no really *good* solution to maintaining high BSE sensitivity while not saturating, but I have used two methods.
1) Multiple images: 2, maybe 3 images, each covering a band of atomic numbers without black/white saturation. The images may be used separately, or colored and an overlay composite made using an image editor.
2) Use non-linear video processing. I modified my (previous GW Elec.) BSE system by adding a clipping diode with a variable reference bias . Could set white clipping just about anywhere in the output range. The clipping/limiting was not "hard" so that some signal variation would make it through. This had the effect of reducing effective gain/brightness on the high end. The degree of gain compression was a function of the original gain & brightness and the new adjustment.
Although only viewable effectively using a software package, another approach would to use more than 256 shades/8 bit gray scale (hardware/software permitting). For Example, a 32 bit gray scale image would likely work fine, but you could only "see" a portion of the range at any time.
Woody White McDermott Technology, Inc.
} -----Original Message----- } From: Gary Gaugler [mailto:gary-at-gaugler.com] } Sent: Friday, December 14, 2001 12:10 AM } To: MSA listserver } Subject: IC cross sections -- with high Z contrast } } } -------------------------------------------------------------- } ---------- } The Microscopy ListServer -- Sponsor: The Microscopy Society } of America } To Subscribe/Unsubscribe -- Send Email to } ListServer-at-MSA.Microscopy.Com } On-Line Help } http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -------------------------------------------------------------- } ---------. } } } hello listers: } } I am working ICs which have an upper and lower } TiW barrier metal layer between AlSi. The problem is } that the huge extreme of Z makes SE and BSE imaging } big time difficult. I tried moderating the range using } Au/Pd (60/40%) but it makes little difference. This } coating was about 40A thick. } } Does anyone have a suggestion about how to normalize } the Z range of materials in this type of specimen so that } either SE or BSE images would show reasonable contrast? } If anyone would like to see my pathetic images at this time, } I can put them on one of my web sites. } } Here are the killer (Z values): } Al=13 } Si=14 } Ti=22 } W=74 (low % but huge impact on image contrast) } } I have thought about Silver (Z47) and Zirconium (Z40) } to try to even out the overall Z range of the specimen. } Unfortunately, Anatech does not make Zirconium } targets for the Hummer VII. I have available Au, Pd, Pt, silver, or } air. } } Am I at the limits of this coater and its target materials? } } TIA, } gary g. } }
I second all the comments made by Warren Straszheim in reply to this posting, but would also suggest what seems to me to be an equally likely possibility given the elements in question - contamination.
Jeff does not mention the form of the samples or the conditions of the experiment, but the observation that the carbon signal increases with analysis time is very common, and is the result of the build-up of contamination resulting from the break-down of hydrocarbon molecules diffusing around the sample surface (sometimes originating from the microscope vacuum, sometime3s carried in with the sample, often both). This is observed much more at high magnifications or in point mode, and both in the SEM and the STEM/TEM. Frequently, a careful examination of an SEM image taken after the analysis will show a spot where the probe had been (in the STEM/TEM the contamination is usually very obvious).
It can be very difficult to predict when you will see contamination problems, and when you won't. Even two samples prepared, supposedly, in the same way, and examined one after the other, may behave differently.
Tony G-R
At 12:24 PM 12/13/2001 -0600, you wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
** Anthony J. Garratt-Reed ** MIT Room # 13-1027 ** 77 Massachusetts Avenue ** Cambridge, MA 02139-4307 ** USA ** ** Phone: (+) 1-617-253-4622 ** Fax: (+) 1-617-258-6478 **
I am considering purchasing a refurbished fluorescence microscope from Microgen Optics. Any feedback re: experience with this company would be much appreciated. Thanks,
Susan Stanton, Ph.D. College of Allied Health Sciences University of Cincinnati Cincinnati, OH 45267-0394
Chemical shift (changing of the position of the peak due to changing energy of the outer electrons because of the chemical interaction) for fluorine should be relatively small. It usually important only for WDS acquisition if it is performed on standard position. For EDS it should be irrelevant since the whole spectra is acquired and chemical shift will affect mostly position and not intensity of a peak.
I think you run into one of the two (or both) problems: 1. Beam induced migration of fluorine (most probable). 2. Carbon contamination under the beam.
You can try to apply methods suitable for beam sensitive specimens. - Use only low magnifications for very fast observing of the specimen. - Make all preparations at higher magnifications - focusing and whatever else - on one place, then move to desired place and perform acquisition as quickly as possible. - Defocus beam as much as possible. - Use shorter acquisition times and lower voltage and beam current.
Vladimir
Vladimir M. Dusevich, Ph.D. Electron Microscope Lab Manager 3127 School of Dentistry 650 E. 25th Street Kansas City, MO 64108-2784
} -----Original Message----- } From: Oakley, Jeff [mailto:oakleyj-at-rayovac.com] } Sent: Thursday, December 13, 2001 12:25 PM } To: 'Microscopy-at-MSA.Microscopy.Com' } Subject: EDS analysis / "Chemical shift" } } } -------------------------------------------------------------- } ---------- } The Microscopy ListServer -- Sponsor: The Microscopy Society } of America } To Subscribe/Unsubscribe -- Send Email to } ListServer-at-MSA.Microscopy.Com } On-Line Help } http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -------------------------------------------------------------- } ---------. } } } I am currently working on an EDS analysis project on carbon / fluorine } matrices. Usually carbon starts as the taller peak, and remains so } throughout the acquisition. Occasionally, however, when starting an } spectrum acquisition I will see the fluorine peak start as } the taller peak, } then slow to become the shorter peak. } } I was told by an observer that there is a phenomenon known as } "chemical } shift," that could have an impact on the amount of certain } elements in the } interaction volume of a sample. This person didn't know much } about it other } than it could give you inaccurate quant results. } } Is there such a thing as chemical shift, and if so, could } someone explain } what exactly is happening during the process? } } Thanks, } } } Jeff Oakley } Rayovac Corporation } } }
Lots of good suggestions. Several questions I did not answer. First, the SEM is an AMRAY 1910 Schottky FESEM. Over a reasonable condenser setting range, the probe diameter is about 90A at high condenser setting, 10KV. I have a new Keithley picoammeter on order to use to re-do the probe diameter measurements and record specimen currents. My DMM approach does/did not work.
The cross section sandwich is non-conducting by its nature. Since the device is a completed IC, it has all underlayers, poly, interlayer dielectric, double metal interconnect, 2KA SiO2 and 10KA SiN passivations. Top down, this device would charge. I can image it at moderate KV and small probe diameter with BSE.
My BSE is a Robinson Model 6. I can mix any amount of SE and BSE in any relationship. SE+BSE, SE-BSE, BSE-SE, etc.
My scope has a Gamma control. However, it does not work. This could be because I'm not using it correctly or have not even turned it on. I will check this for sure. If it is broken, Amray will fix it. Gamma is a good idea to try.
The other idea of separate images of different Z areas of interest has potential. How different this would be from the mixer on the Robinson remains to be seen. Even so, separate images could be shot and aligned afterwards.
Procedurally, the cross sections are made with traditional Buehler equipment and fine diamond paste polish. Specimens without barrier metal turn out quite well. This new lot with TiW is a real problem. The next one has TiN barrier metal. The TiN devices are built on thin SOS. The ones I'm working with now are bulk CMOS. The TiW devices will shift to SONOS early next year.
The consensus seems to be that coating is a waste of time. I can't really argue with that, based on my bad prior history of doing this. I have a new specimen with TiW which is mounted and desiccated overnight. I will try looking at it without any coating. The main glass slide is stuck down on a 90 degree Pella stub and the bottom portion is covered with coloidal silver. The upper part of the specimen is un-touched.
Thanks to all. gary g.
At 03:59 AM 12/14/2001, you wrote: } You didn't mention what type of SEM you are using. I assume that you are } looking at cross-sections of the IC's. We use a FESEM and use 2.5kv and } that works nicely without any coating at all. Before we had the FESEM we } used a gold coater. We did not coat the cross-section directly but laid it } flat down so the gold just drifted over the edge of the cross-section. This } gave us very nice contrast with the metalization and the SiO2. Let me know } how this works for you or give me a call. } Mark } 612-954-2845
Thanks to all for the many excellent suggestions. Some ideas had already been tried while others had not.
Gamma is a good idea. My scope has gamma feature but for some reason, it does not work. A service call should solve that problem. But I found a very nice way to handle the huge Z contrast range in barrier metal ICs.
I still have to coat the specimen with only about 30A of Au/Pd or Pt to eliminate charging. I shoot at between 5-10KV with medium spot size. At this range, the key is to do a SE-BSE image with the amount of subtracted BSE set for best image. This seems rather obvious right now. But it did not this AM.
Setting up the SE for excellent detail and definition in the low Z areas while ignoring the high Z areas is the first action. Then, engage mixing, set for SE-BSE and adjust the amount of SE to BSE so that the overall contrast range is evened out. The results are perfect, I think.
you can see a sample at:
http://photoweb.net/Test7-5dsp8bc.jpg
If anyone has any other ideas or suggestions, please don't hesitate to put them forward.
Thanks, Gary Gaugler, Ph.D. Microtechnics, Inc. Granite Bay, CA 916.791.8191 916.791.8186 fax
Start off the New Year with plans to attend the annual MSA/MAs meeting in Quebec August 4-8 2002. This year, the Education Outreach symposium will be examining the use of image processing as a tool in the academic curriculum. In addition to using image processing as a way to increase the use of microscopic images in classes, Ken and I are interested in new approaches for microscopy or remote access to expand the role of microscopy and microscopes in the classroom at any level.
If you are interested in presenting in this symposium, please contact me. I have included the symposium abstract for your information.
Please note: we are more interested in discussing image processing as a curriculum tool than in discussing 'how to' process images.
See you all in Quebec Steve Barlow
Teaching and Learning - Creating Effective, Innovative Solutions in Microscopy, Imaging, and Analysis Steve Barlow and Ken Baker
Teaching and learning in the field of microscopy imaging and analysis are important to the practice of all forms of microscopy. Microscopy imaging and analysis has adopted an extensive collection of tools and techniques and continues to develop as an increasingly complex subject area. Computer-assisted microscopies, high speed global internet communications, remote microscopies and image acquisition, digital imaging tools, and multidimensional imaging and analysis techniques all offer opportunities for powerful innovation in teaching and learning. Pedagogical resources include: distance learning, on-line manuals, references, tutorials, image databases, and a selection of shared utilities and dedicated discussion forums. This symposium will encourage contributions that emphasize creative, effective, and innovative educational approaches to microscopy, image acquisition and analysis, and increased use of microscopy and images in a student curriculum.
dear colleagues I would like to add anatomy of the beetle. I am looking for nice scan picture of the beetle both sides...
Thank you very much for your help.
Marry Christmas
Keep care and be of good cheer.
Regards
(name) Vratislav Richard Eugene Maria John Baptist (surname) of Bejsak (Bayshark)-Colloredo-Mansfeld
website: http://www.coleoptera.org listserver: coleoptera on www.egroup.com/group/coleoptera/info.html Coleoptera - Australia, Tenebrionidae of World (incl. Lagriinae, Alleculinae)
University of Sydney The Wentworth Bldg., Box 62 NSW 2006 AUSTRALIA phone : +61 414 540 465 email: vratislav-at-bigfoot.com ricardo-at-ans.com.au (before Ricardo-at-compuserve.com and ricardo-at-login.cz )
Only after the last tree has been cut down, only after the last river has been poisoned, only after the last fish has been caught, only then will you find that money can not be eaten.' CREE INDIAN PROPHECY.
Incoming mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com).
on 12/14/01 6:04 AM, Allen Sampson at ars-at-sem.com wrote:
} } As mentioned } by another poster, 'chemical shift' in x-ray spectroscopy refers to the } actual shifts in peak locations caused by chemical bonds altering the } quantum energy levels of the electron shells. This effect will only be } seen on fully focusing Johannson wavelength spectrometers or the more } recent microcalorimeter systems, developed at NIST. } In the interest of completeness, the tunnel junction diode detector, also recently developed, has energy resolution in the few eV range, so it is also able to detect chemical shifts. Yours, Bill Tivol
I have no experience with TEM investigation of coccolithophorids, but for SEM, the folks here spray them onto stubs - they're so tiny they adhere on their own - and then sputter coat. Also, filtering seawater with coccos in it and looking at a cutout from the filter paper (in the SEM, at least) works well for us.
Good luck, Dee }
} Season's Greetings: } } I am looking for anyone with experience looking at coccolithophorids using } TEM. } } We need to look at sections. The guys are only about 5 um in diameter. I } have done some thin layer embedding and individual cell selection before, } but never on anything this small. I will be checking other sources of } information about techniques, but thought I would ask here too, } } Any hints or tips on fixing, embedding, etc. that might help? } } Thanks } } Jonathan Krupp } Microscopy & Imaging Lab } University of California } Santa Cruz, CA 95064 } (831) 459-2477 } jmkrupp-at-cats.ucsc.edu
*************************************************************** Please do not publicly post any of my correspondence without permission
Dee Breger Mgr. SEM/EDX Facility Lamont-Doherty Earth Observatory 61 Route 9W Palisades, NY 10964 USA T: 845/365-8640 F: 845/365-8155
http://www.ldeo.columbia.edu/micro http://www.discovery.com/area/science/micro/micro1.html http://www.lsc.org/antarctica/front.html Journeys in Microspace (Columbia University Press, 1995)
Does anyone know of an antifade agent that works for liver-cell microscopy systems? We're having trouble with fading of the fluorescent signal. Thanks in advance.
Mary
Mary McKee MGH Renal Unit Charlestown, MA 02129 (617)726-3696
I am posting a summary of responses to my request to this list on 3 December 2001, for information about any roles microscopic artifacts may have played in the history of biology. I posted my own experience regarding Sidney Hickson's description of reproductive events in _Millepora_ sp)p). (A copy of my somewhat lengthy post is enclosed at the end of this summary.)
To be fair to Sidney Hickson, who drew and described the incredible, imagined sequence of reproductive events in Millepora sp(p). I mentioned in my original , I believe that he did print a retraction of the findings in that paper.
Gareth Morgan (whose contribution is mentioned below) offered the following remark:
We tend to see what we expect might possibly be there and consciously or unconsciously ignore the rest as 'noise' - perhaps a natural action but also potentially dangerous.
Maureen A. Peterson offered a similar remark, which I took as personal advice:
"Lesson? I better keep my eyes and my mind open."
Both Volker Brinkmann and Mike Dalbey called attention to the "homunculus" (little man-shaped pre-embryos) which were reported in the 18th Century in human sperm.
Volker Brinkmann:
The first microscopic misinterpretation was probably that by Antoni van Leeuwenhook analysing human sperm. He was convinced to see little men with heads, arms and legs swimming around. There are some nice drawings of that.
Mike Dalbey:
Surely the most famous misinterpretations of microscopical observations are those recorded in drawings made by preformationists in the 18th Century of the "homunculus" in the head of human sperm. Several of these drawings are commonly reprinted in textbooks as cautionary examples.
Mike Dalbey further pointed out several interesting examples, including a contemporary issue, the putative bacteria fossiles in the martian meteorite::
For a discussion of a common histological artifact see "Multinucleate Plant Cells" by Burkholder and Mc Veigh (1941) in vol. 68 of the Bulletin of the Torrey Botanical Club p. 395.
You should also check out what the web has to offer on the history of Royal Rife and the Rife Microscope.
Finally, evidence seems to be accumulating that the "nanobacteria" observed by EM in the martian meteorite are artifacts.
Maurreen A. Peterson (Mape-at-mail.ifas.ufl.edu) posted concerning a disease of grapes, a case of failure to see the etiological agent, which was there all the time:
Being a Plant Pathologist, the best I can think of is the story of Pierce's disease of grapes, which was of unknown etiology for a long time. Forgive me for not seeking details from the literature.
At one time it was proposed to be caused by a virus. Extensive light microscope work missed the true cause- a bacterium. After elucidation of the pathogen, I am told that upon review of work previously done, the bacterium WAS there to be seen, but was missed.
Upon a similar vein, MLO's in plants were not recognized in TEM work until a human or animal pathologist saw micrographs of MLO's in plant tissue, and was readily able to say what they were.
Anecdotal, but food for thought.
Two similar misinterpretations of existing evidence were pointed out by Gareth Morgan ( {Gareth.Morgan-at-impi.ki.se} ). The first regarded _Helicobacter pylori_, a causitive agent for gastric ulcers.
Not sure if this one fits the bill but it is a similar one to the grape disease story by Maureen Petersen.
The one I mean is the discovery/description of Helicobacter pylori in human gastric biopsies in the early 80's (when it was given the name Campylobacter pylori). It had been there all of the time but had been disregarded as 'stuff'.
Gareth suggested a google search might reveal more information, and indeed it did: over 82,000 hits. I hope I will be forgiven for quoting one site in part:
Although they were the first to succeed in establishing a link between bacteria and ulcers, the Australians were not the first to try. Since the time of Robert Koch in the late19th century, microscopists observed curved bacteria among the cells under the mucus lining of the stomach, particularly in and around ulcer craters. No one had ever succeeded in isolating the microorganisms, however, and their presence had been explained away as artifact or postmortem contamination. Besides, it was thoroughly accepted among clinical microbiologists of the time that it was unlikely that bacteria could live and grow in the strongly acidic environment of the human stomach.
Warren, a pathologist who examined gastric biopsies, also observed the curved rod-shaped bacteria under his microscope. After examining many such specimens, he realized that the bacteria were always present in tissue that showed signs of inflammation, that the number of organisms correlated with the degree of the inflammation present, and that they occurred in half of the routine gastric biopsy specimens he examined. Convinced that his observations were significant and merited further investigation, he kindled the interest of Barry Marshall, then a trainee in internal medicine, and together they set out to isolate the source of the infection.
[This site is: http://www.faseb.org/opar/pylori/pylori.html]
Gareth also suggested a similar misreading may have been involved with "the finding of Actinomyces in cervical smear material." I was unable to find any clear elucidation of such events; however, one site mentioned that care should be taken by the pathologist in diagnosing "atypical _Mycobacteria_" due to possible presence of Actinomycetes.
H. F. Moura Nunes posted about another possible case:
I am not sure of that. But I heard some years ago that the first information about the structure of poliovirus - in the early days of the electron microscope - was that they were long filamentous structures. Some time later it has been seen that the filamentous structures were in fact bacterial flagella.
Tina Carvalho posted a long discussion of a personal experience regarding another real structure that had been interpreted as an artifact. The experience must be re-posted in its entirety, in spite of its length.
Although I 'm sure there are examples of misinterpretation of artifacts that have been perpetuated for many years, I can offer here a story of the flip side. This is about what appeared to be a well-known artifact that turned out to be, in fact, a surprising real structure. It's also an embarrassing personal story!
An undergraduate student was working with some colleagues who were studying the behavior and neurophysiology of the escape response of several species of planktonic copepods (small crustaceans). They had reams of data and were beginning to characterize the responses of the animals to different kinds of stimuli. Each species had it's own characteristic response, but a general picture was beginning to form. There appeared to be two different classes of response though, one type particularly puzzling. The undergrad spent some time in the EM facility with me, using SEM to describe the sensory setae. She expressed an interest in trying TEM and so we went through fixation, embedding, sectioning, etc. I had worked on the tiny beasts for close to 10 years and had found some interesting structures that I worked on from time to time. Copepods were difficult to fix, some species more so than others. So I had concentrated on the "pretty" ones and temporarily given up on the "ugly" ones - the ones with all those myelin body artifacts that I just couldn't seem to avoid. Finally it was time to try to work on them again, so I gave this one particularly difficult species to the undergrad to try to fix and section. She came to me with micrographs, wondering what in the world were those squiggles she saw. I patiently explained that myelin bodies were a fixation artifact, produced when lipids became mobile during fixation, then reformed in these "onion bodies" . I sent her back to work to try again, and she came up with the same results. "What if they aren't an artifact?" she kept asking. I explained that invertebrates do not have such membranous structures; they were artifactual. I brought out the books and papers about myelin body artifacts. I brought out the books and papers that said invertebrates do not have membranous wrappings around their axons. She was unconvinced. In a hurry one day when she was really bugging me I dug through my files and found the decade-old folder to show her I'd seen the same thing - an artifact. "But there's an axon in the middle of each one", she protested, not knowing that was "impossible". I glanced at them impatiently and saw that she was right, but she was running off to class.
Later that day we looked closely and decided that, indeed, the images were a real mess and difficult to interpret, but there was a faint possibility that these weren't classic myelin body artifacts. Whatever it was was certainly reproducible, and these forms appeared every time in the antennal nerve. So we emailed the PIs of the project and told them we might have myelinated axons in the difficult-to-interpret species. It was April1, April Fools' Day, the undergrad's name was April, and they thought it was a joke. After all, the dogma is that invertebrates don't have myelin! Check any biology book.
But by the next day they realized that myelin (OK, "myelin-like structures" for you purists) would instantly and completely explain 10 years' worth of puzzling data.
It took awhile to prove to ourselves (mainly me, since I'd been repeating the dogma for many years) that these structures were real, orderly, and extensive wrappings of membrane around the axons. It took ultrarapid cryofixation and cryosubstitution to really show that the artifactual bodies that had plagued a number of people working on these critters were in truth these surprising, dogma-busting structures.
We made the April the first author on the Nature paper, which came out in April 1999.
I don't take anything for granted anymore! The lesson is: keep an open mind.
For more on the copepod story- Copepod neuroecology http://www.pbrc.hawaii.edu/~petra/copepod.html
Finally, perhaps appropriately, I include my original posting:
I am interested in gaining insight into the role of microscopic artifacts in the history of biology. May I impose on list members to contribute particularly glaring examples of misinterpreation of biological facts due to improper microscopic technique? I apologize if this is off-topic or a waste of bandwidth.
Let me provide the first example of a misinterpretation and request your assistance in learning whether this was due to improper use of the microscope, or perhaps even malfeasance: Sidney Hickson's early work on Millepora spp. (Cnidaria:Hydrozoa) fire corals. It seems an incredible lapse, a wholly fabricated natural history account, one that persisted for a considerable period in the fabric of the mythology of biological knowledge. I am interested because reproduction of Millepora platyphylla is the subject of incompleted thesis research of mine.
Hickson published a report on reproduction of "Millepora" around the end of the 19th Century. (Anong his other errors he synonomyized all species of Millepora as ecomorphs of one, M. alcicornis.) In this report, which I do not have available at this time, he included several plates of drawings depicting a putative sequence of reproductive events in this organism. We now understand that his depiction is not even close to the way that Millepora spp. (which were later redesignated as proper individual species through painstaking work by Boschma---notwithstanding the issues recently raised by molecular work) reproduce. The depiction involved dozens of drawings, and a sequence of events based on a misinterpretation of what are apparently artifacts.
Hickson (of Cambridge University) worked extensively in the field, including Indonesia and the Philippines. Was his microscopic work done in the field? Are members of this list enlightened as to Hickson's methods?
Hickson's erroneous drawings of the medusae of Millepora lived on for over 3/4 of a century in virtually every Invertebrate Zoology textbook published until the late 1980s or 1990s. His erroneous description of the medusa of Millepora as lacking a velum led to the designation of a separate branch of hydromedusae by Mayer, as the only hydrozoan medusa without a velum. My unpublished observations in the 1980s as well as published observations by John Lewis of McGill University showed that the medusae of Millepora spp. clearly possess a velum.
I apologize for monopolizing the bandwidth. I hope this is as fascinating a topic for others as for myself, and not considered off-topic.
-- Alan E. Davis, Science Instructor Marianas High School PMB 30, Box 10006, Saipan, MP 96950 Northern Mariana Islands adavis-at-saipan.com
"An inviscid theory of flow renders the screw useless, but the need for one non-existent." ---Lord Raleigh(aka John William Strutt),or else his son, Jr., who was also a scientist.
I'd be willing to work on them at $75 plus parts. Most of the problems are cleaning of the stick and guides. Other problems are dirty pots.
Send 'em to me and I can fix them and send them back.
No guarantee, but its worth a shot.
gary g.
At 03:40 AM 12/12/2001, you wrote: } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America
I am an undergraduate ChemE major at the University of Rhode Island and I had a question on techniques and AFm capabilities.
Is there a way to measure the force a piezoelectric crystal applies with a certain voltage using an AFM and proscan version 1.5b.0001
Right now I can use the cantiliever to exert force and measure the spring constant of a sample by pushing down, using spectroscopy.
Can it be done without pushing the cantilever down, and instead put a voltage though the crystal and have the crystal push up and measure the force exerted?
Also, on a side note, what is the best way to prepare a blood sample onto a slide (or what would be better than a slide) in a study on the aging of blood. This study will be using primarily AFM techniques, and perhaps nanoindentation. It will also be using the same samples for several weeks, perhaps monthes. After only a week the samples are already crumbling. How can I keep them at ambient conditions, and still keep them from breaking apart?
Hello listers: I am currently trying to prepare TEM samples of polycrystalline strontium titanate (grain size ~20 micron) by conventional dimpling/ion milling. However, due to porosity, I have been having problems in thinning down this material. One of the suggested sample prep methods was to thin the material up to say ~50micron and then embed some sort of epoxy in it, so that the epoxy will fill in the pores. Could someone explain to me how to do this? What type of epoxy should I use and how do I ensure that the epoxy has filled up the pored? Thanks, Prad
Pradyumna Prabhumirashi Dept. of Materials Science Northwestern University Phone: (847)491-7798 Fax : (847)491-7820
A postdoctoral associate position is immediately available in the Department of Molecular & Cellular Biology, Baylor College of Medicine, Houston, TX. The work focuses upon steroid receptor function in an integrating molecular, biochemical, genetic and cell biological approach, and is extremely imaging intensive (including both live and fixed cells, LM/EM). Specific interests address questions of the relationship between transcription factor function, subnuclear organization, intranuclear dynamics and associations with nuclear structure. This single cell approach also allows examining in vivo protein-protein interactions, large-scale chromatin organization, and direct transcription read-out using cell lines with integrated bioluminescent reporters. Imaging resources include state-of-the-art confocal and deconvolution microscopy, and a new digital transmission electron microscope. All microscopes and robust computer/software resources are housed in a completely redesigned/renovated Integrated Microscopy Core. The ideal candidate will have extensive molecular/biochemical experience, OR, extensive imaging/computer training. The ability to communicate exceptionally well (oral and written) and interact with a larger group studying mechanisms of receptor function from many other angles is imperative.
Interested applicants should send an electronic CV and a cover letter expressing their research interests and career plans to:
Michael A. Mancini, Ph.D. Assistant Professor Director, Integrated Microscopy Core Department of Molecular & Cellular Biology Baylor College of Medicine Houston, TX 77030 713.798.8952 mancini-at-bcm.tmc.edu http://microscopy.bcm.tmc.edu web version of the ad: http://208.188.94.28/templates.asp?PageID=127
References:
Stenoien DL, Nye AC, Mancini MG, Patel K, Dutertre M, O'Malley BW, Smith CL, Belmont AS, Mancini MA. (2001) Ligand-mediated assembly and real-time cellular dynamics of estrogen receptor alpha-coactivator complexes in living cells. Molecular and Cellular Biology. 21:4404-12.
Stenoien DL, Patel K, Mancini MG, Dutertre M, Smith CL, O'Malley BW, Mancini MA. (2001). FRAP reveals that mobility of oestrogen receptor-alpha is ligand- and proteasome-dependent. Nature Cell Biology. 3:15-23.
Stenoien DL, Mancini MG, Patel K, Allegretto EA, Smith CL, Mancini MA. (2000). Subnuclear trafficking of estrogen receptor-alpha and steroid receptor coactivator-1. Molecular Endocrinology. 14:518-34
One quick question.....I am currently performing a general TEM fixation on petunia petals. In our lab, we place plant tissue (once dissected and in fixative) in a vacuum to remove the air. This normally causes the tissue to sink. For these petals, however, I have had them in a vacuum 5 times so far (around 15 minutes each time, or until they "bubble over") and some of them are still not sinking..........
It's almost as if they are hydrophobic. Does anyone know if there is something about petals in general that makes them more difficult to infiltrate with the fixative? I am doing leaves as well and they sank to the bottom just fine.
Does anyone else on this list perform a lot of plant tissue (leaves / petals) fixation? If so, do you place your samples in a vacuum, or use a detergent like Triton X to get the tissue to sediment?
I'm wondering how much damage is caused by placing the tissue in a vacuum as opposed to using a detergent. I know the detergent disrupts membranes, but wouldn't a vacuum have the same effect? Are there other means to get the tissue to sediment? Is one technique better than the other?
I am helping a museum establish a protocol to identify residues on African tribal beads, which is thought to be fecal matter. The sample material will be limited to micrograms and will contain mineral and other contaminants. Can anyone recommend microchemical or micro tests that might be used to differentiate fecal matter?
If the material is dried out, the bugs will probably be dead and uncultivable. Microscopy observation, unless there are specific antibodies against enteric bacteria available for labeling, will be useless. Probably the best test would be a molecular test for E. coli (e.g., PCR).
On Mon, 17 Dec 2001, James Martin wrote:
} Date: Mon, 17 Dec 2001 16:10:05 -0500 } From: James Martin {james.s.martin-at-att.net} } To: microscopy-at-sparc5.microscopy.com } Subject: microchemical tests for fecal matter } } ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } } I am helping a museum establish a protocol to identify residues on African } tribal beads, which is thought to be fecal matter. The sample material will } be limited to micrograms and will contain mineral and other contaminants. } Can anyone recommend microchemical or micro tests that might be used to } differentiate fecal matter? } } With thanks, } } Jamie } } } }
Sara E. Miller, Ph. D. P. O. Box 3712 Duke University Medical Center Durham, NC 27710 Ph: 919 684-3452 FAX: 919 684-3265
I have gained the above mentioned microprobe, but it doesn't work yet. It was disassembled in another building, brought over and I have reassembled it to the best of my ability. Kind of a baptism by fire.
The chiller is chilling and the water is coursing around the oil reservoir as well as into the appropriate parts under the column. The oil, used to cool the objective lens, is running from inside that reservoir through new hoses. And the vacuum measures in the 0-5 micro amp range where I'm told it should be (its actually 0.3 at the gun and 0.5 in the column). And the penning gauge measures in the 10^-5 range at the main evacuation manifold - that's good, too.
There is a gauge (Load/Filament) on the Accelerating Voltage panel that should light up "when the vacuum is at the desired level" according to the manual. But something is not allowing that to happen. Consequently, the high voltage cannot be turned on. And there is the rub.
We do not have a service contract on this beast yet. I have called the service people and they have given me a considerable amount of help to date. We just can't get any farther than this. Is there any help for me and my albtross?
Kind regards, --
+++++++++++++++++++++++++++++
R. Ann Bliss Technician, Chemistry and Materials Science Materials Science and Technology Division Lawrence Livermore National Laboratory
Please let me give you a perspective from that of a photographer. In this respect, I have poop specimens which are between days and years old. They all seem to share the same basic characteristics. There is fiber, bulk, stuff, and lots of E. coli. I have also found a few cocci in the mess.
These specimens were sealed under #1 cover slips with cyanoacrylate glue. They are still viable to this day.
The specimens I made for SEM were not very sophisticated. I would have fixed them with Osmium and done CPD. I am not set up to do this. But what I found was that the bacteria were crushed by the high vacuum of the SEM....but they were still viable, morphologically. But without fixing, they deteriorate rapidly. Even stored at 40mT, they do not hold up. Being devoid of Oxygen, the bacteria seem to be confused--as I have seen nearly zero spores. Only dead rods. Of course, there may be other organisms present which do not sporulate. Anyway, not many spores are seen.
It seems to me that the standard protocol for bacterial fixation is quite good and certainly appropriate. In contrast, the LM method can go on for a long time. But of course, the magnification and resolution between LM and SEM is quite different.
But...to your problem. Given that you have a very small amount of material with which to work, experimentation is not a luxury. I would suggest taking a small amount of material and doing a gas chromatograph analysis on it and then taking another small amount and examining it under SEM. With the SEM of the material, you will probably see a lot of crap that is not at all associated with the human crap (feces). What I mean is, junk. This will take some doing to evaluate. Sorting it all out will not be easy at all.
Lots of luck.
gary g.
At 01:10 PM 12/17/2001, you wrote:
} I am helping a museum establish a protocol to identify residues on African } tribal beads, which is thought to be fecal matter. The sample material will } be limited to micrograms and will contain mineral and other contaminants. } Can anyone recommend microchemical or micro tests that might be used to } differentiate fecal matter? } } With thanks, } } Jamie
I would recommend you ask this question to the SPM mailing list http://www.di.com/spm%20forum/spmforummailinglist.html
You may also find the information you need in the application notes found at the DI and Thermomicroscope websites (they are now the same company but still have separate websites): - www.di.com and http://www.tmmicro.com/
DeltaDOT Ltd. PFSG group ACE Building Department of Bioengineering Imperial College London SW7 2AY
0207-594-5174 0794 - 1312335
www.deltadot.com
Information on scanning probe & microfluidics : www.achem.ic.ac.uk/gsanders **************************************************************************** ******* **************************************************************** ----- Original Message ----- } From: "Keith Cochran" {Cochrak-at-egr.uri.edu} To: "Microscopy Listserve" {Microscopy-at-sparc5.microscopy.com} Sent: Monday, December 17, 2001 12:41 AM
Karli Yes, petals are very often hydrophobic. They are covered with a waxy, hydrophobic cuticle. The cell surfaces are very often papillate and the papilla surface may be minutely wrinkled, increasing the water contact angle so that the surface is non-wettable. The most important thing (and this applies to fixation of many types of plant leaves too) is that the pieces you are fixing are small enough for the glutaraldehyde fix to penetrate rapidly via the cut edges - it will penetrate only exceedingly slowly, if at all, via the cuticle, so total immersion is not worth striving for. Cutting pieces 1/2 (half) to 1 mm square should be the aim. Do this using a slicing action with a very sharp degreased razor blade with the petal in a pool of glutaraldehyde in a petri dish, so that cut surfaces are immediately exposed to fix. Subsequent vacuum infiltration will help to get the fix into the tissue if the petals (or leaves) have a lot of intercellular air space, but they will continue to float.
Chris
----- Original Message ----- } From: "Karli Fitzelle" {fitzelle.1-at-osu.edu} To: {Microscopy-at-sparc5.microscopy.com} Sent: Monday, December 17, 2001 8:51 PM
I am DR Nelson Afam {a Civil servant in the ministry of Health} here in Nigeria. I know this letter would come to you as a surprise because we have not met before either physically or through correspondence. I got your contact from our chamber of commerce here in Nigeria and have no doubt in your ability to handle this proposal involving huge sums of money.
The Subject: My father chief Michael Afam {Now late} was the Royal head of my community, Eleme {an oil rich town} in Nigeria. My community produce 5.8% of the total annual crude oil production in Nigeria and 0.5% of the Dollar value of each barrel is paid to my father as royalty by the federal government. In his position as the royal head and chairman of the Akwaeze oil trust fund, he made some money which he behind for his children. The money is twenty five Million, Six thousand US Dollars {$25 .6m}. This money originated from the accumulated royalties between 1998.
Due to poor banking system in Nigeria and political\economics instability as a result of past military rules {1985-1999}, he deposited this money in a “Box” with an open beneficiary in a local security firm. He told the security Company that the content of the box is Gold worth $25.6m. And the box will be safeguarded until he finishes arrangement to transfer it abroad. He was planning this when he died last year of heart Attack.
The Proposal: Just before my father died, he called my attention in confidence to the money and charged me to look for a foreigner who would assist me in the transfer\investment of the fund. So I would be very grateful if you could accept to help me achieve this great object. I promise to give you 20% of total fund s transferred as compensation for your assistants. Five present {5%} would be set aside to take care of all expenses we may incur during the transaction. To the indicate your interest, contact me urgently and confidentially through E-mail for information and the roles you will play in the business. God bless you. DR Nelson Afam
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Jeff- I do not know what beam energy you are using, but another possibility is that the sample(s) in question are charging enough to reduce the effective landing energy of the primary electrons thus altering the peak ratios. I would be surprised if this is what is occurring in your case since the C and F peaks aren't that far apart in energy, but fluorocarbons can be very insulating. With my PGT EDX system in mapping mode, I can view the quasi-real-time count rates in the C and F energy windows. Perhaps if your system can do the same, that could shed some light on your problem (e.g. are both C and F signals getting smaller with the F signal doing so faster, or is F going down as C is going up?). Are the samples gold coated? Does gold coating eliminate the observed effect? Good luck.
Sincerely, Matthew Ervin, Ph.D. (301)394-0017 phone, (301)394-1559 fax MErvin-at-ARL.Army.mil
M/S: AMSRL-SE-RL US Army Research Laboratory 2800 Powder Mill Road Adelphi, MD 20783-1197
Disclaimer: The opinions and views expressed above are those of the author and do not necessarily represent those of the U.S. Army Research Laboratory or any other government agency
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I am currently working on an EDS analysis project on carbon / fluorine matrices. Usually carbon starts as the taller peak, and remains so throughout the acquisition. Occasionally, however, when starting an spectrum acquisition I will see the fluorine peak start as the taller peak, then slow to become the shorter peak.
I was told by an observer that there is a phenomenon known as "chemical shift," that could have an impact on the amount of certain elements in the interaction volume of a sample. This person didn't know much about it other than it could give you inaccurate quant results.
Is there such a thing as chemical shift, and if so, could someone explain what exactly is happening during the process?
Karli, This primary fixative worked very well for Arabidopsis inflourescences even the smallest buds. I also used it for fixing bean (Fava) leaves but in that case I needed a brief vacuum to submerge the leaf samples. The reference is included. 2.8 % glutaraldehyde Buffer 0.1 M Hepes buffer (pH- 7.2) + 0.02% Triton X-100 Buffer wash 0.1 M Hepes buffer
Owen, Heather A., and C.A. Makaroff, Ultrastructure of microsporogenesis and microgametogenesis in Arabidopsis thaliana (L.) Heynh, ecotype Wassilewskija (Brassicaceae) Protoplasma (1995) 185:7-21
It was a long time ago that I worked with 733, but as I remember the vacuum control board has two or three variable resistors which set thresholds, including threshold for turning on high voltage. This board is not very stable and thresholds needs to be readjusted from time to time. I believe it could be your problem. Consult with manual which resistor control high voltage threshold (or are they marked on the board?).
Good luck,
Vladimir
Vladimir M. Dusevich, Ph.D. Electron Microscope Lab Manager 3127 School of Dentistry 650 E. 25th Street Kansas City, MO 64108-2784
} -----Original Message----- } From: R. Ann Bliss [mailto:bliss5-at-popcorn.llnl.gov] } Sent: Monday, December 17, 2001 7:06 PM } To: Microscopy-at-sparc5.microscopy.com } Subject: JEOL 733 Help needed } } } -------------------------------------------------------------- } ---------- } The Microscopy ListServer -- Sponsor: The Microscopy Society } of America } To Subscribe/Unsubscribe -- Send Email to } ListServer-at-MSA.Microscopy.Com } On-Line Help } http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -------------------------------------------------------------- } ---------. } } } Happy Holidays: } } I have gained the above mentioned microprobe, but it doesn't work } yet. It was disassembled in another building, brought over and I have } reassembled it to the best of my ability. Kind of a baptism by fire. } } The chiller is chilling and the water is coursing around the oil } reservoir as well as into the appropriate parts under the column. The } oil, used to cool the objective lens, is running from inside that } reservoir through new hoses. And the vacuum measures in the 0-5 micro } amp range where I'm told it should be (its actually 0.3 at the gun } and 0.5 in the column). And the penning gauge measures in the 10^-5 } range at the main evacuation manifold - that's good, too. } } There is a gauge (Load/Filament) on the Accelerating Voltage panel } that should light up "when the vacuum is at the desired level" } according to the manual. But something is not allowing that to } happen. Consequently, the high voltage cannot be turned on. And there } is the rub. } } We do not have a service contract on this beast yet. I have called } the service people and they have given me a considerable amount of } help to date. We just can't get any farther than this. Is there any } help for me and my albtross? } } Kind regards, } -- } } +++++++++++++++++++++++++++++ } } R. Ann Bliss } Technician, Chemistry and Materials Science } Materials Science and Technology Division } Lawrence Livermore National Laboratory } } _____________________________ } }
Regarding the recent question I posted about flashing current decreasing with each tip flash in a Hitachi S4700 FESEM, the problem appears to have been in the gun cable contacts. The Hitachi engineer flashed the tip several times, getting tiny increases in current each time, then checked the contacts on the cable. The next flash produced a MARKED increase in flashing current and the system is now running normally.
My question was aimed more at understanding at the theory behind all this, since the scope was performing just fine, but it turns out to have been a simple mechanical problem fixable in about five minutes.
Thanks again for all the replies.
Randy Tindall EM Specialist Electron Microscopy Core Facility W122 Veterinary Medicine University of Missouri Columbia, MO 65211 Tel: (573) 882-8304 Fax: (573) 884-5414 Email: tindallr-at-missouri.edu Web: http://www.biotech.missouri.edu/emc/
When I open a SE image into Photoshop (v6), it has been my practice to assign a generic gamma=2.2 working space to it. Better, would be to assign whatever space it was acquired with (i.e., the actual display profile for the SEM computer). My thinking is, since we make all adjustments with that display, it is the gamma space I should be associating the SE image to. And indeed, the image appears just like it did at the SEM computer.
However ... the SEM image acuisition software only allows me to fill up the histogram, endpoint to endpoint, without any tools for what's between (gamma). Am I somehow doing the acquisition an injustice with respect to the detector's true gamma?? What if the SE detector's true gamma is unity (e.g., like x-ray maps)?? Has anyone ever determined what a SE detector's apparent gamma is?? If for the sake of the images' data integrity, shouldn't acquisition software be aware of detector gamma, and compensate for the monitor's gamma??
genuinely ... michael shaffer :o) Avalon Peninsula, Newfoundland
I cannot help this person. I was wondering if anyone out their could. Please contact him directly.
-----Original Message----- } From: Nellis, David [mailto:dnellis-at-ncifcrf.gov] Sent: Tuesday, December 18, 2001 11:12 AM To: 'semguy-at-semguy.com' Cc: Giardina, Steve
Dear Listies,
I'm having a bit of trouble sectioning epidermis and dermis. The dermis has thick collagen bundles that tear when thin sectioned for TEM. The epidermis stays intact.
I've tried LR White for better infiltration, initial 15% resin infiltration, extended infiltration times, increased and decreased knife angle, glass knives, diamond knives, decreased and increased cutting speeds.
Befuddled,
Tim Quinn University of Kansas Research Assistant Natural History Museum and Biodiversity Research Center Dyche Hall Room 414 Lawrence, KS 6604-2454 785-864-4556 tquinn-at-ku.edu
I don't have an answer to your specific question, but I do have a paper titled "Technique for the Preparation of TEM Plan-View and Cross-Section Samples of YBa2Cu3O7 Thin Films on MgO and SrTiO3" by Dr. Stephen Strieffer that may be of help. If you would like a copy of the paper, please send me your complete mailing address off-line and I will get it out to you. We also have many other technical papers and application notes available on our website under "Applications Support" at www.southbaytech.com.
DISCLAIMER: South Bay Technology produces equipment and supplies which are described in the above mentioned paper and, therefore, has a vested interest in promoting their use.
I hope this helps.
Best regards-
David
Pradyumna Prabhumirashi wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } Hello listers: } I am currently trying to prepare TEM samples of polycrystalline } strontium titanate (grain size ~20 micron) by conventional dimpling/ion } milling. However, due to porosity, I have been having problems in } thinning down this material. One of the suggested sample prep methods } was to thin the material up to say ~50micron and then embed some sort of } epoxy in it, so that the epoxy will fill in the pores. } Could someone explain to me how to do this? What type of epoxy should I } use and how do I ensure that the epoxy has filled up the pored? } Thanks, } Prad } } Pradyumna Prabhumirashi } Dept. of Materials Science } Northwestern University } Phone: (847)491-7798 } Fax : (847)491-7820
-- David Henriks TEL: +1-949-492-2600 South Bay Technology, Inc. FAX: +1-949-492-1499 1120 Via Callejon San Clemente, CA 92673 USA e-mail: henriks-at-southbaytech.com
You have to be careful when referring to gamma. I read a technical article about 1-1/2 years ago that discussed the use of gamma processing and the definition of gamma in different media. It is different for display monitors, film, SEM's etc. I wish that I had photographic memory so that I could recall the points -but I do remember being surprised because of the different definitions in various fields of imaging technology. I had learned about gamma from an SEM course and thought of it as the processing curves shown in the Goldstein et al. book.
I don't think that you should be using gamma processing on SEM images after you collect them. The SEM should have gamma processing on the output of the detector amplifier to the analog to digital converter. Do it electronically to capture what you need from the image. Of course, you should set up the digital image so that as much of the gray scale is used as possible. After a digital image is acquired, the middle control in Photoshop's level control, i.e. the gamma, should only be needed to be moved slightly to adjust the average gray level of the image. If your SEM doesn't have this ability to adjust gamma before the image is digitized, then you can always do a gamma correction using the LUT (Look up table. My philosophy is to use as much of the gray scale as possible when the image is made and to put the average gray level where I like it. I adjust all the display monitors to display what a properly set up image should look like.
Another thing about the SE detector is that the PMT ages. So that if you did set up or relied on some value, over time it would change.
-Scott
Scott D. Walck, Ph.D. PPG Industries, Inc. Glass Technology Center P. O. Box 11472 (letters) Guys Run Rd. (packages) Pittsburgh, PA 15238-0472
Walck-at-PPG.com
(412) 820-8651 (office) (412) 820-8515 (fax)
-----Original Message----- } From: michael shaffer [mailto:rarewolf-at-roadrunner.nf.net] Sent: Tuesday, December 18, 2001 10:26 AM To: MSA listserver
When I open a SE image into Photoshop (v6), it has been my practice to assign a generic gamma=2.2 working space to it. Better, would be to assign whatever space it was acquired with (i.e., the actual display profile for the SEM computer). My thinking is, since we make all adjustments with that display, it is the gamma space I should be associating the SE image to. And indeed, the image appears just like it did at the SEM computer.
However ... the SEM image acuisition software only allows me to fill up the histogram, endpoint to endpoint, without any tools for what's between (gamma). Am I somehow doing the acquisition an injustice with respect to the detector's true gamma?? What if the SE detector's true gamma is unity (e.g., like x-ray maps)?? Has anyone ever determined what a SE detector's apparent gamma is?? If for the sake of the images' data integrity, shouldn't acquisition software be aware of detector gamma, and compensate for the monitor's gamma??
genuinely ... michael shaffer :o) Avalon Peninsula, Newfoundland
I do not understand purpose of replicating SEM monitor. I think it is more useful to set PC monitor so that it will correspond to printed image (or to averege PC's monitor, if digital images are going to be electronically distributed).
Vladimir
Vladimir M. Dusevich, Ph.D. Electron Microscope Lab Manager 3127 School of Dentistry 650 E. 25th Street Kansas City, MO 64108-2784
} -----Original Message----- } From: michael shaffer [mailto:rarewolf-at-roadrunner.nf.net] } Sent: Tuesday, December 18, 2001 9:26 AM } To: MSA listserver } Subject: SE detector gamma } } } -------------------------------------------------------------- } ---------- } The Microscopy ListServer -- Sponsor: The Microscopy Society } of America } To Subscribe/Unsubscribe -- Send Email to } ListServer-at-MSA.Microscopy.Com } On-Line Help } http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -------------------------------------------------------------- } ---------. } } } When I open a SE image into Photoshop (v6), it has been my } practice to } assign a generic gamma=2.2 working space to it. Better, } would be to assign } whatever space it was acquired with (i.e., the actual display } profile for } the SEM computer). My thinking is, since we make all } adjustments with that } display, it is the gamma space I should be associating the SE } image to. And } indeed, the image appears just like it did at the SEM computer. } } However ... the SEM image acuisition software only allows } me to fill up } the histogram, endpoint to endpoint, without any tools for } what's between } (gamma). Am I somehow doing the acquisition an injustice } with respect to } the detector's true gamma?? What if the SE detector's true } gamma is unity } (e.g., like x-ray maps)?? Has anyone ever determined what a } SE detector's } apparent gamma is?? If for the sake of the images' data integrity, } shouldn't acquisition software be aware of detector gamma, } and compensate } for the monitor's gamma?? } } genuinely ... michael shaffer :o) } Avalon Peninsula, Newfoundland } } } }
Hello, We want to determine the lattice parameter of nanoparticles on amorphous carbon as a function of size in the TEM. The nanoparticles are smaller than an extinction length, so I can't use dynamical diffraction techniques such as CBED. We are planning on coating the backside of the carbon film with a standard such as gold to use as a reference for SADP analysis. Does anyone know of a better technique to use to determine the lattice parameter of these nanoparticles in the TEM?
Thank you in advance,
Tom Schamp
University of Virginia Dept. of Materials Science cts2v-at-virginia.edu
We are considering purchasing a CL detector for our Philips (now FEIC) XL30 SEM. We are looking for a cost effective CL detector for diagenetic and paragenetic studies of geological materials, typically sandstones. I have looked over the Gatan (formerly Oxford) web site and I wondered if any users out there have used these detectors? If so could you send recommendations or advice regarding the possible options for CL detectors? If there are any other companies out that also make detectors please let me know.
Thanks in advance,
Nick Wilson
Dr. Nick Wilson Research Scientist Geological Survey of Canada 3303-33rd St. N.W. Calgary AB, Canada T2L 2A7 Tel: 403-292-7045 Fax: 403-292-7159 Email: nwilson-at-nrcan.gc.ca
Job Announcement: Electron Microscopy (full time, permanent) Research Scientist level Health Research Inc., Wadsworth Center, Albany, NY 12058.
We are looking for a motivated, mature and responsible individual to join a state-of-the-art Federal funded biomedical research laboratory. Flexible job hours in a challenging and stimulating research environment. Will train for specialized tasks.
Minimum qualification: B.S. in biology with experience in specimen sectioning and electron microscopy. Preferred qualification: B.S. in biology with experience in serial sectioning and electron microscopy.
Responsibilities: 1. Embedding various biological specimens for transmission electron microscopy analyses. 2. Thin and thick (serially) sectioning of specimens. 3. Scanning and photographing sections with the EM 4. Conducting 3D analyses.
Contact: Richard Cole Research Scientist III Director: Advanced Light Microscopy Core Unit Wadsworth Center P.O. Box 509 Albany N.Y. 12201-0509 518-474-7048 Phone 518-486-4901 Fax
I think you can try to determine it by means of HRTEM.
Chun-Ming Li Dept. of Materials Science and Engineering University of Illinois at Urbana-Champaign 1304 West Green St. Urbana, IL 61801 Email: lichun-at-uiuc.edu
Tom Schamp wrote:
} ------------------------------------------------------------------------ } The Microscopy ListServer -- Sponsor: The Microscopy Society of America } To Subscribe/Unsubscribe -- Send Email to ListServer-at-MSA.Microscopy.Com } On-Line Help http://www.msa.microscopy.com/MicroscopyListserver/FAQ.html } -----------------------------------------------------------------------. } } Hello, } We want to determine the lattice parameter of nanoparticles on } amorphous carbon as a function of size in the TEM. The nanoparticles } are smaller than an extinction length, so I can't use dynamical } diffraction techniques such as CBED. We are planning on coating the } backside of the carbon film with a standard such as gold to use as a } reference for SADP analysis. Does anyone know of a better technique to } use to determine the lattice parameter of these nanoparticles in the } TEM? } } Thank you in advance, } } Tom Schamp } } University of Virginia } Dept. of Materials Science } cts2v-at-virginia.edu
We have a group in our institution that is putting together a setup for microinjection. The group interested in this setup is going to be microinjecting fluorescent labeled compounds into adherent cells. We are currently looking at a Zeiss Axiovert 25 CFL. This is a very popular microscope which allow for phase contrast and fluorescence. The only drawback of this microscope and others in this price range is that the mercury lamp is only 50 Watts. The 50W lamp is fine for routine fluorescence but my question is whether it will be effective in picking up dimly lit samples like the fluorescent compounds we are going to microinject?
I received this query, and I cannot help her. Anyone out there who can? Please respond offline to Dr. Marszal.
We wonder if it is possible to have TEM images (with negative staining) taken in your facility as a service. We need to analyze protein polymer samples. If it can be done as a service, what fee could we expect per sample? Such an analysis was done for us before and we know the approximate conditions of the experiment. Also, if it can be done, how soon can we do it? If you do not provide the service, what are the other options; can I participate in the analysis although I have never operated an electron microscope?
Ewa Marszal, PhD FDA/CBER HFM-345 1401 Rockville Pike, Suite 200 N Rockville, MD 20852-1448 phone: 301-402-4638 fax: 301-402-2780
-- Leona Cohen-Gould, M.S. Sr. Staff Associate Director, Electron Microscopy Core Facility Manager, Optical Microscopy Core Facility Joan & Sanford I. Weill Medical College of Cornell University voice (212)746-6146 fax (212)746-8175
I'd suggest a harder resin, an epoxy type, to give support to the collagen bundles. Try Spurrs or Embed812, formulated for a harder block. Both are also a fairly low viscosity type resin. You may have to try a few hardness formulas to get it right. Use the diamond knife, if its in good shape, that is.
Good luck,
Gib
-- Gib Ahlstrand Electron Optical Facility, University of Minnesota, CBS Imaging Center, 35 Snyder Hall, St. Paul, MN. USA. 55108 (612)624-3454 (612)625-5754 FAX, giba-at-puccini.cdl.umn.edu http://www.cbs.umn.edu/ic/
} Dear Listies, } } I'm having a bit of trouble sectioning epidermis and dermis. The dermis has } thick collagen bundles that tear when thin sectioned for TEM. The epidermis } stays intact. } } I've tried LR White for better infiltration, initial 15% resin infiltration, } extended infiltration times, increased and decreased knife angle, glass } knives, diamond knives, decreased and increased cutting speeds. } } Befuddled, } } Tim Quinn } University of Kansas } Research Assistant } Natural History Museum and Biodiversity Research Center } Dyche Hall Room 414 } Lawrence, KS 6604-2454 } 785-864-4556 } tquinn-at-ku.edu