Materials Literature
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The kinetics and mechanism of the synthesis and degradation of polyhydroxyalkanoates (PHA) in Alcaligenes eutrophus have been studied. PHA polymers were accumulated in the cells in nitrogen-free mineral media containing various carbon substrates, and the accumulated PHA polymers were subsequently degraded after the ca…
Abstract The crystalline structure of the M 2 CuWO 6 phases with M = Ba or Sr was obtained from X-ray powder diffraction at room temperature with CuK α radiation. The phases are isostructural with tetragonal unit cells, space group I4/m and Z = 2. The parameters for the Sr 2 CuWO 6 phase are: Mr = 518.6, a = 5.42693(5…
Abstract Surface roughness and thickness uniformity are two of the most important parameters to control in the manufacture of polymeric films. In this paper, we present the results of a detailed experimental study on the effect of biaxial stretching variables on these parameters in polyethylene terephthalate and poly…
Argon ions (Ar+) were implanted into a substrate of natural graphite (crystal) by 4 kV acceleration for a period of 5 min using a VG EX05 ion gun. (The surface plane of the substrate was perpendicular to the flight path of the argon ions.) No attempt was made to maximize the argon concentration within the graphite. Th…
The ability to achieve high twisting rates without the need to rotate the heavier mechanical elements and the low yarn tensions enable very high delivery rates with friction spinning. The soft handle of the yarn, versatility to handle all types of fibres and the core spinning facility are the other meri.ts of this sys…
Aus Cer und Kaliumpolyselenid in der Schmelze ist KCeSe 4 zugänglich. Die Struktur dieses neuartigen Lanthanoidpolychalcogenids ist verwandt mit der CuAl 2 ‐Struktur, und Ce und Se bauen anionische Schichten mit K + Ionen in den Zwischenräumen auf. Die Ce 3+ ‐Ionen sind quadratisch‐antiprismatisch von acht Se ‐Einheit…
Abstract Alkaline earth element-added boron and phosphorus mixed oxides supported on Cab-O-Sil showed high catalytic activity in partial oxidation of methane to HCHO at < 773 K. The results of the experiment using 18O2 suggested that the lattice oxygen atoms of the catalyst are responsible for the oxidation.
Symmetry analysis of possible magnetic structures with k = 0 and of phase transitions is described for the metallic perovskites Mn3MN (M = Ni, Ga, Ag, Sn, Zn). The phase transition from a triangular antiferromagnetic structure to a triangular noncomplanar structure is considered phenomenologically in detail. Theoretic…
Silicon is the second most abundant element in the earth's crust and occurs widely in nature as silica (silicon dioxide) or as silicate minerals. Although these materials have many uses, the most extensive use of silicon is found in the materials which can be derived from these inorganic precursors. These derivatives…
Low-energy electron microscopy (LEEM) and mirror electron microscopy (MEM) utilize a parallel beam of slow-moving electrons backscattered from the specimen surface to form an image. If the electrons strike the surface an LEEM image is produced and if they are turned back just before reaching the surface an MEM image r…
Theoretical yields of poly-d(−)-3-hydroxybutyrate (PHB) from several carbon sources have been estimated from biochemical pathways leading to PHB. In estimating the yields, a special emphasis is made on recycling (or regeneration) of NADP+ which is the co-substrate of acetoacetyl-CoA reductase, one of three key enzymes…
Abstract Novel microcellular PVC foams with a very homogenous cell distribution and cell densities ranging from 10 7 to 10 9 cells/cm 3 have been created using carbon dioxide as the nucleating gas. Microcellular foams with relative densities (density of foam divided by the density of unfoamed polymer) ranging from 0.1…
Abstract A new X-ray diffraction pattern for the compound cerium oxygen apatite, Ce 4.67 [SiO 4 ] 3 O is suggested. The compound was prepared by the solid state reaction of the oxides, CeO 2 and SiO 2 and has a hexagonal crystal structure with the lattice constants a = 9.6578 Å and c = 7.1187 Å. The sample of the most…
X-ray photoelectron spectroscopy (XPS) was used to characterize a highly oriented pyrolytic graphite (HOPG) sample. The HOPG was cleaved using scotch tape prior to introduction into an ultrahigh vacuum analytical chamber. No further cleaning was used as no elements other than carbon were detected in XPS survey scans.…
Abstract Die Kristallstrukturen von Mg 3 Ni 20 P 6 (a = 11,113(3) Å) und Mn 3 Ni 20 P 6 (a = 11,085(1) Å) wurden röntgenographisch mit Einkristallmethoden bestimmt. Beide Verbindungen, dargestellt durch Erhitzen entsprechender Elementgemenge, bilden eine Besetzungsvariante der Cr 23 C 6 ‐Struktur (Fm3m), in der viele…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTInfrared spectra of [n]staffanesMurthy S. Gudipati, Steven J. Hamrock, V. Balaji, and Josef MichlCite this: J. Phys. Chem. 1992, 96, 25, 10165–10176Publication Date (Print):December 1, 1992Publication History Published online1 May 2002Published inissue 1 December 1992https:/…
Interferometric measurements of the chirality-induced biaxiality in the vicinity of the uniaxial-to-biaxial cholesteric transition of the lyotropic system potassium laurate, decylammonium chloride, ${\mathrm{H}}_{2}$O, and brucine sulfate are reported. The mean-field approach to describe the cholesteric-to-cholesteric…
M\"ossbauer spectroscopy, magnetic susceptibility, and Rietveld analysis were used to study the magnetic and structural properties of ${\mathrm{YSr}}_{2}$${\mathrm{Cu}}_{2}$${\mathrm{FeO}}_{\mathit{y}}$ prepared under different annealing conditions. The structure was refined using the tetragonal space group P4/mmm for…
Synthesis and characterization of 2,5-dimethyl-1-phenylpyrrole.
Abstract— The possibility of using specially prepared single crystals as indicators of fatigue damage is outlined. Results are described of an analysis of deformation patterns developed in the single‐crystal indicator surface, under fatigue and static loading. It is shown that the density and direction of deformation…