I have noticed it with new pucks (most likely some kind of grease from manufacturing) and later on when used in dry shipping dewars that has old absorbent coating. Also it might be that your dewar is not holding vacuum very well. Usually it can be cleaned with compressed air but have decided to change dewar anyway and problem disappeared.
Michal On Feb 21, 2020, at 18:40, Diana Tomchick <diana.tomch...@utsouthwestern.edu> wrote: CAUTION: This email originated from outside of the University of Saskatchewan. Do not click links or open attachments unless you recognize the sender and know the content is safe. If in doubt, please forward suspicious emails to phish...@usask.ca I believe my technician decided that it was due to the breakdown of the adsorbent foam in our oldish shipping dewar, as it stopped happening once we replaced that particular dewar. But I would be open to other explanations. Diana ************************************************** Diana R. Tomchick Professor Departments of Biophysics and Biochemistry UT Southwestern Medical Center 5323 Harry Hines Blvd. Rm. ND10.214A Dallas, TX 75390-8816 diana.tomch...@utsouthwestern.edu<mailto:diana.tomch...@utsouthwestern.edu> (214) 645-6383 (phone) (214) 645-6353 (fax) On Feb 21, 2020, at 6:33 PM, Emilia C. Arturo (Emily) <ecgart...@gmail.com<mailto:ecgart...@gmail.com>> wrote: EXTERNAL MAIL Hi All, We have been noticing lately that our crystal pucks return from different beamlines coated with the same powdery material. For the record, we typically undo our pucks, clean the assemblies and dry out the pucks within a day of receiving the shipping dewar, but notice the same thing regardless of how long between receiving the dewar and disassembling the pucks. Have any of you experienced this sort of thing, or have suggestions of what might be the cause and/or the powdery material? Regards, Emily. -- "Study as if you were going to live forever; live as if you were going to die tomorrow." - Maria Mitchell "I'm not afraid of storms for I'm learning to sail my ship." - Louisa May Alcott ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 CAUTION: This email originated from outside UTSW. Please be cautious of links or attachments, and validate the sender's email address before replying. ________________________________ UT Southwestern Medical Center The future of medicine, today. ________________________________ To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1 ######################################################################## To unsubscribe from the CCP4BB list, click the following link: https://www.jiscmail.ac.uk/cgi-bin/webadmin?SUBED1=CCP4BB&A=1
