Materials Literature
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SUMMARY Release of potassium from 15 surface samples of benchmark Alluvial, Red and Black soils of India to 0.01 M solutions of BaCl 2 , CaCl 2 , NH 4 Cl and NaCl was studied in soils either untreated or pretreated with 5 × 10 −3 M KCl. In the untreated soils, the efficacy of the extractants declined in the sequence:…
2,3-Bisphosphoglycerate-independent phosphoglycerate mutase (EC 5.4.2.1) was purified and characterized from maize. SDS electrophoresis showed only one band with a molecular mass of 64 kDa, similar to that determined for the native enzyme by gel-filtration chromatography. The kinetic constants were similar to those re…
A method is described for examining and measuring fiber cuticular scale patterns from optical micrographs, impressions, or SEMs. The captured images are initially manipulated using several image processing functions to clarify scale structure. Image analysis is then done using a chain-coding routine that allows a numb…
Pullets of three genetic stocks derived from commercial White Leghorn-type chickens differed in relative productivity when they were beak trimmed or not and kept in 6-hen cages in a well-lighted house. An important part of the apparent discrepancy in rankings among stocks was associated with differences in mortality f…
Dynamic mechanical and tensile stress-strain properties were measured for four sets of acrylic pressure sensitive adhesives, and were compared to industry standard “applications” peel and shear properties. Correlations were established showing that more than half of the range of performance shown by commercial PSA's i…
We have incorporated the flexoelectric terms in developing one-dimensional models of E.H.D. instabilities in nematics both under D.C. and A.C. excitations. It is shown that, using this model, we can account for the following experimental observations, which could not be adequately explained by earlier models: (i) The…
Abstract The thermal degradation of polybutadiene (PB) samples having different initial contents of cis ‐1,4‐, trans ‐1,4‐ and 1,2‐units were investigated at temperatures lower than 250°C, where cyclization, cross‐linking and cis ‐ trans isomerization occur without depolymerization. Changes of the cis ‐ trans content…
Abstract The structure of well ground cellulose I and cellulose II samples was studied by measuring the X‐ray scattering intensities and calculating the corresponding radial atomic density functions (RDFs). Experimentally obtained results have been compared with model calculations mainly varying the packing of nearest…
Abstract The catalytic power of Ca-nontronite, Ca-bentonite, and Ca-kaolinite in promoting the abiotic ring cleavage of pyrogallol (1,2,3-trihydroxybenzene) and the associated formation of humic polymers was studied in systems free of microbial activity. The presence of Ca-kaolinite and especially Ca-nontronite in the…
We determined the value of MR for detecting abnormalities of the uterus caused by in utero exposure to diethylstilbestrol in patients in whom such abnormalities were evident on hysterosalpingography. Of 200 women with a history of diethylstilbestrol exposure in utero, 12 had undergone hysterosalpingography as part of…
The utility of circularly polarized luminescence (CPL) spectroscopy in the study of lanthanide ion coordination chemistry has been described. A variety of optically active Tb(III) and Eu(III) compounds have been considered, containing chiral carboxylic acids, chiral amino acids, chiral aminopolycarboxylic acids, achir…
Abstract Dynamic mechanical thermal analysis and calorimetric studies are reported on blends of poly(ethylene oxide) (PEO) with poly( N ‐vinyl pyrrolidone) (PVP) between 80% and 40% PEO. DMTA curves show a peak corresponding to a phase of pure PEO and another peak which can be attributed to blended material. The calor…
Abstract The formation of kaolinite from Al hydroxy interlayered Garfield nontronite has been carried out at 225°C in hydrothermal conditions. The kaolinitization process, which proceeds through mixed-layer kaolinite/smectite intermediates, was followed by XRD, IR and ESR spectroscopy, chemical analysis and charge pro…
The d.c. flux decay test has been proposed as an alternative and attractive method of extracting synchronous machine parameters. With the machine stationary, direct current is passed through two phases and the decay of current is observed following the short-circuiting of the supply. Tests on two large turbinegenerato…
Anodicallyoxidized alumina has been investigated theoretically and experimentally concerning the anisotropy of its optical loss and refractive index. When the pores in the alumina film are filled with metallic materials, the film yields anisotropy of the optical loss and consequently acts as a polarizer. However, the…
Abstract Under the right conditions, high strengths are shown to be achievable in vibration welded polycarbonate to polyetherimide Joints. While welding of thermoplastic interfaces of the same material can be understood in terms of interchain diffusion at elevated temperatures, this mechanism is severely limited in th…
By inserting a lambda placMu bacteriophage into gene glmS encoding glucosamine 6-phosphate synthetase (GlmS), the key enzyme of amino sugar biosynthesis, a nonreverting mutant of Escherichia coli K-12 that was strictly dependent on exogenous N-acetyl-D-glucosamine or D-glucosamine was generated. Analysis of suppressor…
Abstract A quantitative simulation in the cluster approximation is made of an autolocalized hole in the amorphous SiO 2 network. A model is suggested in which the thermal excitation of holes from Anderson localized states of the top of the silica valence band above the mobility edge corresponds to the thermally stimul…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA new tetranuclear oxohydroxoiron(III) cluster: crystal structure, magnetic properties, and EXAFS investigation of [L4Fe4(.mu.-O)2(.mu.-OH)4]I4.cntdot.3H2O (L = 1,4,7-triazacyclononane)Stefan Drueke, Karl Wieghardt, Bernhard Nuber, Johannes Weiss, Emile L. Bominaar, A. Sawar…
Abstract CO 2 sorption and transport were investigated for the polyimide prepared from 3,3′,4,4′‐biphenyltetracarboxylic dianhydride (BPDA) and 4,4′‐diaminodiphenyl sulfone (DDS). The morphology of films did not change on annealing above the glass transition temperature and remained amorphous unlike the polyimide prep…