scholarly journals Physico-chemical properties of Selenium-Tellurium alloys across the scales

2021 ◽  
Author(s):  
Luke D Geoffrion ◽  
Gregory Guisbiers

Selenium and tellurium are both energy critical elements as defined by the American Physical Society and the Materials Research Society. When mixed together, both elements form an alloy. The size-...

MRS Bulletin ◽  
1992 ◽  
Vol 17 (7) ◽  
pp. 70-77 ◽  
Author(s):  
T.H. Geballe

I would like to raise a question of interest to many of us here today: “Why have we not been able to find a room-temperature superconductor?” I have a scenario for why not that can be illustrated by projecting ahead 98 years. It is 2089, the tercentenary of the French Revolution. The revolt against science that started building up in the last decade of the 20th century has reached a crescendo and a revolutionary tribunal has erected a huge guillotine. Following in the tradition of Lavoisier's trial and execution, the presidents of the Materials Research Society, the American Chemical Society, and the American Physical Society have been found to be enemies of the people and have been sentenced to be guillotined. The president of the Materials Research Society steps up. In his final words, he says: “I have no regrets. We've supplied you with the pole vaults which have made possible a new world's record above 30 feet, we've given you automobile bumpers that prevent damage in crashes at 60 miles per hour, and we've given you tennis rackets that are big enough to allow you to cover from center court to the alley without having to take a step.” With that, he bravely puts his head on the block. Down crashes the knife but inexplicably it stops just before it reaches his neck. According to the rules he steps down a free man. Then the American Chemical Society president steps up and says: “I don't have any regrets either. We have given you body centered cubic diamond that makes it possible to build indestructible houses, we have given you disposable diapers that are biodegradable in 30 seconds, and we've reseeded the stratosphere with ozone. We have done our job.” She courageously puts her head on the block, and the guillotine comes down. Again it stops short and she walks away, a free woman. Then the president of the American Physical Society says: “I don't have any regrets either. We've circled the equator with our newest SSC and have given you the Higgs boson, we've given you light that you can squeeze until it hurts, and we've discovered over 100 theoretical models which should lead to room-temperature superconductors. We haven't given you any real ones because there aren't any—we've tested all the possibilities. But, by the way, while we've been standing here, I've done a back-of-the-envelope calculation and I've found out wha's wrong with this guillotine. If you give me a screwdriver I can fix it.”


MRS Bulletin ◽  
1997 ◽  
Vol 22 (7) ◽  
pp. 3-4
Author(s):  
Sabrina J. Diol

Through my interdisciplinary graduate work, I have attended conferences organized by various professional societies such as the Materials Research Society (MRS), American Physical Society (APS), Optical Society of America (OSA), and American Chemical Society (ACS). I have also participated in some of their employment workshops and have searched their websites for employment resources. This article elaborates on information and services that professional societies and organizations can provide to ease employment search for their student membership.Career Workshops. These workshops provide excellent guidance, especially for students initiating their employment search. Obviously, the best ones are conducted by people who recruit PhD graduates. I attended an employment workshop organized by the American Institute of Physics (AIP) during the 1995 MRS Fall Meeting. An extremely dynamic hightechnology industrial recruiter conducted the workshop. The mock interviews, mininetworking groups, and resume and cover letter critique involved audience participation and were highly effective. I strongly recommend such a workshop. On the other hand, I have also been frustrated with workshops in which speakers did not have a technical PhD background since I often found their suggestions unsuitable.Employment Database. A website with current job postings mainly for PhD graduates is extremely useful. The National Academy of Science (http://www2.nas.edu) is among the few sources for this. The critical issue in this case is to have a well-maintained site with frequent updates and a search engine. Another alternative, which we have been using at the University of Rochester, is to circulate job postings via electronic mail. Again, timeliness is the key issue.


Author(s):  
H. Gross ◽  
H. Moor

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.


1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)


1963 ◽  
Vol 79 (2) ◽  
pp. 263-293 ◽  
Author(s):  
E.M. Savitskii ◽  
V.F. Terekhova ◽  
O.P. Naumkin

1990 ◽  
Vol 39 (442) ◽  
pp. 996-1000 ◽  
Author(s):  
Ayao TAKASAKA ◽  
Hideyuki NEMOTO ◽  
Hirohiko KONO ◽  
Yoshihiro MATSUDA

Food Biology ◽  
1970 ◽  
pp. 19-23
Author(s):  
Nawal Abdel-Gayoum Abdel-Rahman

The aim of this study is to use of karkede (Hibiscus sabdariffa L.) byproduct as raw material to make ketchup instead of tomato. Ketchup is making of various pulps, but the best type made from tomatoes. Roselle having adequate amounts of macro and micro elements, and it is rich in source of anthocyanine. The ketchup made from pulped of waste of soaked karkede, and homogenized with starch, salt, sugar, ginger (Zingiber officinale), kusbara (Coriandrum sativum) and gum Arabic. Then processed and filled in glass bottles and stored at two different temperatures, ambient and refrigeration. The total solids, total soluble solids, pH, ash, total titratable acidity and vitamin C of ketchup were determined. As well as, total sugars, reducing sugars, colour density, and sodium chloride percentage were evaluated. The sensory quality of developed product was determined immediately and after processing, which included colour, taste, odour, consistency and overall acceptability. The suitability during storage included microbial growth, physico-chemical properties and sensory quality. The karkede ketchup was found free of contaminants throughout storage period at both storage temperatures. Physico-chemical properties were found to be significantly differences at p?0.05 level during storage. There were no differences between karkade ketchup and market tomato ketchup concerning odour, taste, odour, consistency and overall acceptability. These results are encouraging for use of roselle cycle as a raw material to make acceptable karkade ketchup.


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