Materials Literature
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To explain the low-frequency dielectric relaxation of many types of materials, the current relaxation phenomenon induced in an inhomogeneous conductor with a spatial distribution of local conductivity is investigated. The nonuniform current density produces the true charge (conduction charge). The origin of the relaxa…
An experimental apparatus has been developed to permit the simultaneous measurement of moisture sorption by a fabric and moisture flux through a fabric during the transient period after the fabric is exposed to a humidity gradient. By suitable manipulation of the experimental conditions, the method demonstrates that m…
compatible with A1-Fe phases in the same composition range; (3) the m value is ~4.0-4.4; (4) the strongest diffraction spots are fundamental, i.e. most atoms scatter in phase. From these assumptions, a framework of 126 atoms in the unit cell was set up, which produced the strongest diffraction spots. 'Vacancies' and F…
Machine learning (ML) is transforming all areas of science. The complex and time-consuming calculations in molecular simulations are particularly suitable for an ML revolution and have already been profoundly affected by the application of existing ML ...Read More
The structural gene of pyruvate formate-lyase (pfl) and that of pyruvate-formate-lyase-activating enzyme were shown to be adjacent on the chromosomal map of Escherichia coli. DNA sequencing was performed along a stretch of 3592 nucleotides to obtain the amino acid sequences of both proteins. The derived primary struct…
A system of hard spherocylinders near an impenetrable wall is studied in the low-density Onsager approximation. Using a simple local approximation for the one-particle distribution function, we show that the preferred orientation of the nematic director is parallel to the wall. The density and order-parameter profiles…
Residual thermal stresses and strains, developed during cooling of a SiC whisker‐Al 2 O 3 composite, were determined by an experimental neutron diffraction technique and the results were compared with analytically determined values. High compressive residual thermal stresses were generated in the whiskers during coold…
The convolutive X-ray peak profile-fitting methodology described in the previous paper [Enzo, Fagherazzi, Benedetti & Polizzi (1988). J. Appl. Cryst. 21, 536–542] has been applied to a series of fluorite samples milled for different times and two zirconia ultra-fine powders, by using either pseudo-Voigt or Voigt (in t…
A detailed neutron-powder-diffraction experiment as a function of temperature has revealed the existence of a reversible structural transition at about 80 K in stoichiometric ${\mathrm{La}}_{2}$Ni${\mathrm{O}}_{4}$. This phase transition is characterized by the anomalous behavior of the orthorhombic strain with no app…
The stability of the phases in equilibrium is calculated for the Si‐C‐N‐O system in order to analyze and predict the reactions in ceramic whisker formation and sintering of silicon nitride composites. Equilibria among SiC, Si 3 N 4 , Si 2 N 2 O, SiO 2 , Si, and the gas phase are evaluated at different carbon activitie…
Abstract— For a variety of chemically defined, synthetic and natural porphyrins, the tendency for self aggregation, binding to serum albumin, distribution coefficient betweenoctanol–1 and water and uptake in V79 Chinese hamster cells have been determined. A strong correlation was found between cell uptake and distribu…
A wet‐chemical approach is applied to derive fine powders with compositions 11 mol% CeO 2 ‐ZrO 2 , 1 mol% YO 1.5 ‐10 mol% CeO 2 ‐ZrO 2 , 12 mol% CeO 2 ‐ZrO 2 , and 2 mol% YO 1.5 ‐10 mol% CeO 2 ‐ZrO 2 by the coprecipitation method. The characteristics of the as‐derived powders are evaluated through thermal analysis and…
Abstract Due to their unique polarity, pore-size distribution, and high surface areas, pillared and delaminated clays are potentially useful materials for the adsorption of environmental toxicants. To determine their properties for adsorption of chlorinated phenols, alumina-pillared montmorillonite (APM), chromia-pill…
NiOx films were made by dc magnetron sputtering of Ni in O2 at a rate of <0.15 nm s−1. The grain size was ∼10 nm and the crystal structure was cubic. Electrochemical hydration, and ensuing conversion to electrochromic NiOxHy, took place in KOH. Spectrophotometric measurements in the 0.35–2.5-μm range showed tha…
Abstract The structure parameter x (also known as the nonlinearity parameter), which in the KAHR model determines the relative contributions of temperature and structure to the retardation times of polymers in the glass transition region, is evaluated experimentally for a narrow molecular weight fraction of atactic po…
Application de simulations par ordinateur utilisant la technique de dynamique moleculaire a un verre de silice dans des domaines de temperature compris entre 300 et 9000 K et de pression compris entre 0 et 175 kbar
Incident-beam monochromators have been available commercially for many years, but the significant advantages of their use in conventional divergent-beam diffractometry are not widely appreciated. The improvement in the quality of diffraction data which results from the removal of the Kα2 component of Kα radiation at s…
Transcription of the Bombyx mori fibroin gene in a posterior silk gland extract can be separated into three functional steps on the basis of sensitivity to Sarkosyl: 1) formation of an initiation complex, which is blocked by 0.025% Sarkosyl; 2) conversion of the initiation complex to an elongation complex, a step sens…
The Bacillus subtilis hom gene, encoding homoserine dehydrogenase (L-homoserine:NADP+ oxidoreductase, EC 1.1.1.3) has been cloned and its nucleotide sequence determined. The B. subtilis enzyme expressed in Escherichia coli is sensitive by inhibition by threonine and allows complementation of a strain lacking homoserin…
The isotropic elastic moduli of four specimens of nitrogen‐stabilized cubic aluminum oxide (ALON) were measured using pulse superposition interferometry. Experiments were carried out as a function of both pressure (ambient to 1 GPa) and temperature (0° to 25°C) for specimens of 30.0 and 35.7 mol% AlN. The second‐order…