Materials Literature
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Previously we have shown how to obtain the electric properties of a polymer or other periodic system at the coupled Hartree–Fock level by direct, analytical calculation rather than by extrapolation of oligomer results. Here we add computationally simpler noniterative formulas and test the methodology for the longitudi…
In silicon and other materials with a high Peierls potential. dislocation motion takes place by nucleation and propagation of kink pairs. The rates of these unit processes are complex unknown functions of interatomic interactions in the dislocation core, stress and temperature. This work is an attempt to develop a qua…
The genus Saccharothrix is phylogenetically heterogeneous on the basis of analysis of almost complete 16S rDNA sequences. An evaluation of chemotaxonomic, morphological and physiological properties in the light of the molecular phylogeny data revealed that several species are misclassified. Saccharothrix aerocolonigen…
The transformation kinetics and microstructures of glass‐ceramics, which deviate from those of a stoichiometric cordierite compound, are greatly dependent on the compositions of the starting glasses. Compositions richer in (MgO,SiO 2 ) than the stoichiometric cordierite compound suppress the formation of μ‐cordierite,…
Low-frequency (100 Hz-1 MHz) dielectric studies of the AgNb 1- x Ta x O 3 (ATN) (0⩽ x ⩽0.4), Ag 1- x K x NbO 3 (AKN) (0⩽ x ⩽0.04), Ag 1- x Li x NbO 3 (ALN) (0⩽ x ⩽0.04) and Ag 1- x Na x NbO 3 (ANN) (0⩽ x ⩽0.4) solid solution ceramics were carried out in the temperature range 120-700 K. The dielectric dispersion was on…
MyristoylCoA:protein N-myristoyltransferase (Nmt) attaches myristate to the N-terminal Gly residue of proteins involved in a variety of signal transduction cascades, and other critical cellular functions. To gain insight about the structural basis of substrate recognition and catalysis, we determined the structures of…
In the present work, additions of 2% vanadium, 2% niobium and 2% titanium were respectively made to a high-chromium white iron (17% Cr) to analyse the effect of these elements on the as-cast structure of the alloy, and their influence on the material's hardness. This study was carried out for different solidification…
Decrease in luminous intensity of multibubble sonoluminescence (MBSL) at excessive ultrasonic intensity is studied in connection with the behavior of cavitation bubbles. The intensity of MBSL from aerated distilled water in a rectangular vessel with six transducers, in which a standing wave field was established, was…
Thin semiconducting thermoelectric films with narrow energy band gaps are considered to be very promising for future microdevice applications (sensors and generators). The polycrystalline BiSbTe alloys (V–VI semiconductors) are examples. In this report, the detailed temperature dependence of electrical resistivity [ρ(…
Effect of retained austenite on the corrosion performance of modified 13% Cr martensitic stainless steel (0.025%C-13%Cr-[4% to 6%]Ni-[1% to 2%]Mo) seamless pipe is investigated. Retained austenite in the modified 13% Cr steel pipe was formed in the tempering period and its volume was affected by tempering temperature.…
In 1998 Siemens AG (SAG) took over the tubular Solid Oxide Fuel Cell (SOFC) technology from Westinghouse. This merger placed SAG under the responsibility of Siemens Westinghouse Power Corporation (SWPC), and gave them the opportunity to concentrate on this technology as the most promising fuel cell option for the emer…
Standard EXAFS analysis on Ce x Zr 1 - x O 2 mixed oxides leads to incorrect structural parameters. A comparison of XRD Rietveld analysis with an EXAFS study of a Y-doped reference compound and a Ce 0.5 Zr 0.5 O 2 catalyst showed that in order to obtain reliable structural parameters with EXAFS an anharmonic pair dist…
We report a polarization beam splitter that uses polarization gratings written onto a zero-twist nematic liquid-crystal display. We show three configurations. The first two separate the diffracted light into two orthogonally polarized orders that are either linearly or circularly polarized. In the third configuration,…
In the framework of the Peierls model generalized to two dimensions the dissociation of a dislocation in the {111} plane of a fcc lattice into two Shockley partials is studied by a variational procedure. Each partial is made up by a distribution of infinitesimal dislocations with a density obtained by a superposition…
Layered double hydroxysalt green rusts, GRs, are very reactive compounds and their general formula, [Fe 2 (1-x) Fe 3+ x (OH) 2 ] x+ [x/n A n- ·m H 2 O] x- , where x is the ratio Fe 3+ /Fe tot , reflects the structure in which brucite-like layers alternate with interlayers of anions A n- and water molecules. A GR miner…
Polymer nanocomposites consisting of 32 nm diameter TiO 2 nanoparticles and epoxy resin were ultrasonically processed and the mechanical and permeability properties of the resulting composites were compared to composites containing 0.24 μm TiO 2 particles and to neat resin. It was found that the nanocomposites with we…
Abstract A series of the longest class of oligothiophenes extended at intervals of seven thiophene units from the 6-mer up to the 48-mer has been synthesized by a combination of the random Eglinton coupling reaction of mono- and di-ethynylsexithiophenes and a subsequent sodium sulfide-induced cyclization reaction of t…
Abstract Fire retardants may considerably improve the fire properties of wood products, but the durability, e.g. in exterior applications, has not been addressed fully. This paper reviews the existing knowledge and experience mainly from the USA with the aim of supporting further development in Europe. The review is c…
The yeast enzymes involved in UDP-GlcNAc biosynthesis are potential targets for antifungal agents. GNA1, a novel member of the Gcn5-related N-acetyltransferase (GNAT) superfamily, participates in UDP-GlcNAc biosynthesis by catalyzing the formation of GlcNAc6P from AcCoA and GlcN6P. We have solved three crystal structu…
Two different phases of LaMnO3+δ [one showing a metal–insulator transition (MIT), referred to as LaMn–C, and the other not showing a MIT, referred to as LaMn-S] have been clearly observed to follow two different conduction mechanisms. Interestingly, small polaron hopping models of Mott, Schnakenberg, and Emin are foun…