Low temperature electroplated Au?SnNi?Au ohmic contacts on n type GaAs

A method is described for fabricating ohmic contacts on n type GaAs by alloying electroplated layers of Au-SnNi-Au at 300°C, resulting in a contact resistance of approximately 3 × 10?5 ? cm2. In applications for which this resistance is adequate, the technique has the advantage of requiring low-temperature alloying for short times.     

Productivity and scholarly impact (citations) of British, Canadian, and U.S. departments of psychology (1975).

Evaluated the psychology departments at 180 universities in Canada, the United Kingdom, and the US in terms of their productivity and the impact of their scholarly research. The 1975 Social Science Citation Index (SSCI) was used as the basis for counting both citations of and publications by each of the 5,597 faculty members. Psychologists at the 180 evaluated departments received a total of 76,189 citations in 1975 (mean 13.6) and produced a total of 4,977 publications (mean .89). Data are presented for the top 100 departments: total, mean, and median number of citations of each department as well as the total and mean number of publications. The citation measures correlated more highly with reputational ranks taken on 76 American schools in an earlier study than did the publication measures. The departments of psychology at 4 universities were consistently in the top 8 on the total, mean, and median citation measures of scholarly impact: Stanford, Harvard, Yale, and the University of Pennsylvania. 18 of the top 100 departments in terms of total citations were from either Canada or the United Kingdom. Methodological difficulties in using the SSCI and possible uses and limitations of citation counts are discussed. (24 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

CONTENTS OF SIMPLE,POLYMERIC AND COMPLEXED FLAVANOLS IN WORTS AND BEERS AND THEIR RELATIONSHIP TO HAZE FORMATION

The highest concentrations of complexed and polymeric flavanols were found in the early runnings from a small-scale mash tun. Formation of break during and after boiling was accompanied by the removal of flavanols from solution, especially the complexed and polymeric fractions. Variations in boiling procedure affected the amount of break formed, the amount of residual soluble flavanols and the colloidal stability of the resultant worts. Colloidal stability in beer was influenced by the contents of simple flavanols and the availability of air during storage. Dimeric and trimeric flavanols seemed especially susceptible to oxidation which implied an important role in haze formation. Flavanols found in commercial beers were mainly monomeric and complexed forms.     

Analysis of polymer membrane formation through spinodal decomposition. III: Two-dimensional simulations of early-stage behavior

A nonlinear diffusion equation is used to study early-stage spinodal decomposition of polymer solutions, in relation to the membrane formation, in two dimensions. The effects of overall polymer composition and composition-dependent mobility and diffusivity are included in our simulations. Our results show a kinetically stable structure is established during the early stages, which corresponds to a circular range of peaks in the two-dimensional frequency spectrum. Such a spectrum is found to result in an interconnected cell structure in the two-dimensional real space. A decrease in the level of polymer interdomain interconnectedness is obtained as time increases, which indicates the influence of interfacial tension. As the overall polymer composition is increased, an increase in interdomain distances is observed, although the same early stage morphological structure is obtained. Finally, calculated interdomain distances from the two-dimensional simulation are larger than those obtained in equivalent one-dimensional model systems.     

A study of the complexing properties of a hydrosoluble polymer based on modified polyacrylamide containing diethanolamine functions

The grafting addition of diethanolamine functional groups on polyacrylamide was carried out by a Mannich reaction. The polymer obtained includes amino alcohol functions as well as carboxylate functions due to partial hydrolysis. The complexing power of this polymer toward Cu²⁺ ions shows an increased stability of the complexes compared to those obtained with diethanolamine. The range of existence is similarly extended for the complexes with a high degree of coordination due to the proximity of the complexing sites in the macromolecular chain.     

Polarized liquid3He in a4He circulating dilution refrigerator

We have used a⁴He circulating dilution refrigerator to produce cold liquid³He with a steady state out-of-equilibrium nuclear spin polarization. Polarizations on the order of 15% (more than 7 times higher than the equilibrium polarization in the external field of 6.6 T) have been obtained in the mixing chamber of the refrigerator at temperatures between 10 and 15 mK. The polarization is enhanced at high pressure because the molar susceptibility of concentrated³He is larger than that of the dilute phase. The polarization exchange between the dilute and concentrated phases (in direct contact in the heat exchanger of the refrigerator) amplifies the enhancement. The polarization diminishes below a pressure of 2.6 bar. This allows us to scale and reinterpret susceptibility data of the dilute phase¹ in combination with the effective mass deduced from osmotic pressure measurements². We find 1+F ₀ ^a = 0.89±1% on the phase separation line in the pressure range 0–20 bar.We would like to thank Profs. D.M. Lee and M.S. Tagirov for the many discussions during their visits.     

The production of ochratoxin A and citrinin in barley

The production of ochratoxin A by Aspergillus ochraceus and of ochratoxin A and citrinin by Penicillium viridicatum growing on previously sterilised barley for 200 days at 5, 10 and 20°C and a water activity of 0.85 is reported. A. ochraceus did not grow at 5°C, multiplied slowly at 10°C but did not produce toxin. At 20°C the organism multiplied more quickly and produced ochratoxin after 19 days, which slowly disappeared over the next 150 days. P. viridicatum grew slowly at 5°C but did not produce any toxin. It multiplied at 10°C and produced ochratoxin A which was only detectable during the period from 100 to 150 days. At 20°C both ochratoxin A and citrinin were produced. Ochratoxin A was detected after 10 days and was still present after 240 days, whereas citrinin was produced in large quantities between 118 and 129 days and then rapidly disappeared.