Materials Literature
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The crystal structures of the four experimentally observed phases of ${\mathrm{Si}}_{3}{\mathrm{N}}_{4}$ with space groups ${P6}_{3}/m,$ ${P6}_{3},$ ${P3}_{1}/c,$ and ${\mathrm{Fd}}_{3}/m$ are fully optimized by means of first-principles total-energy calculations. The relaxation of all internal parameters is achieved…
The thermal conductivity and the cellular structure as well as the matrix polymer morphology of a collection of chemically crosslinked low-density closed cell polyolefin foams, manufactured by a high-pressure nitrogen gas solution process, have been studied. With the aid of a useful theoretical model, the relative con…
A facile approach to engineering diverse mixed-colloid ensembles is presented here. Various colloid architectures are seen that are controlled by both electrostatic self-assembly and concentration changes (see Figure) regardless of the nature of the nanoparticle core. The methodology should be applicable to the creati…
Neutron-powder-diffraction measurements, combined with magnetization and resistivity data, have been carried out in the doped perovskite ${\mathrm{La}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ $(x=0.47,$ 0.50, and 0.53) to elucidate the structural, magnetic, and electronic properties of the system around…
Abstract Effects of particle size of Al(OH) 3 (ATH) filler on electrical properties of ethylene propylene diene terpolymer (EPDM)/ATH compounds were studied. It was found that tracking and erosion resistance of EPDM/ATH compounds decreased while dielectric properties and 90°C water resistance were improved with the in…
Abstract A model dissolution/reprecipitation process is studied for the recycling of both polyϵ‐caprolactam (PA 6) and polyhexamethyleneadipamide (PA 6 6). This process comprises dissolution of each of the aforementioned polyamides in an appropriate solvent, reprecipitation by addition of a nonsolvent and finally reco…
A new homologous series of thermotropic liquid crystalline poly(azomethine-ether)s was synthesized by solution polycondensation of various diformyl-alpha,omega-diphenoxyalkanes, I-VIII with 2,5-bis(m-aminobenzylidene)cyclopentanone, XI and 2,6-bis(m-aminobenzylidene)cyclohexanone, XII. The inherent viscosities of the…
Abstract We studied the effect of liquid crystal polymer (LCP) and surface modification of neodymium‐iron‐boron (Nd‐Fe‐B) magnetic alloy on the magneto‐mechanical behavior of poly (phenylene sulfide) (PPS) bonded Nd‐Fe‐B magnets to accelerate efforts to develop useful thermoplastic magnets with optimal performance. Th…
Abstract Thermal conductivities of undoped and various protonic acid-doped polyaniline films were measured by combination of a laser flash method and a scanning differential calorimeter. The thermal conductivities thus measured are in the range of conventional organic polymers, indicating that the doped polyaniline fi…
The structures and relative energies for the basic conformations of silacyclohexane 1 have been calculated using HF, RI-MP2, RI-DFT and MM3 methods. All methods predict the chair form to be the dominant conformation and all of them predict structures which are in good agreement with experimental data. The conformation…
Mechanisms of dissipation of the excitation energy in garnet crystal phosphors Y 3 Al 5 O 12 and Y 3 Ga 5 O 12 doped with rare-earth ions with interconfiguration transitions are studied depending on the Ga concentration.
Poly(styrene-co-methacrylic acid) P(St-co-MAA) microspheres with a monodisperse size distribution were prepared by emulsifier-free emulsion copolymerization of St and MAA. The effects of MAA content on the polymerization rate and the content of MAA in the copolymer were investigated by gravimetrical and IR methods, re…
The free R factor is used routinely as a cross-validation tool in macromolecular crystallography. However, without any means of deriving quantitative estimates of its expected value and variance, its application has been rather subjective and its usefulness therefore somewhat limited. In the first part of this series,…
High‐density lead zirconate titanate (PZT) ceramics were fabricated for the first time at a temperature as low as 800°C via the hot isostatic pressing (HIP) of a PZT powder with a modified composition of 0.92Pb(Zr 0.53 Ti 0.47 )O 3 —0.05BiFeO 3 —0.03Ba(Cu 0.5 W 0.5 )O 3 that contained 0.5 mass% MnO 2 . The resultant P…
Capacitive-resistive field computations are carried out around post-type HV insulators of varying shapes. The boundary element method (BEM) has been employed for electric field computations. Different insulator shapes have been obtained by varying several parameters, which define the shape of the HV insulator contour.…
The Saccharomyces cerevisiae YDL219w (DTD1) gene, which codes for an amino acid sequence sharing 34% identity with the Escherichia coli D-Tyr-tRNA(Tyr) deacylase, was cloned, and its product was functionally characterized. Overexpression in the yeast of the DTD1 gene from a multicopy plasmid increased D-Tyr-tRNA(Tyr)…
A data set from the serine protease porcine pancreatic elastase was collected at atomic resolution (1.1 A) with synchrotron radiation. The improved resolution allows the determination of atom positions with high accuracy, as well as the localization of H atoms. Three residues could be modelled in alternative positions…
The corrosion behavior of mild steel in acetic acid (CH3COOH) solutions was studied by weight loss and potentiostatic polarization techniques. The variation in corrosion rate of mild steel with concentrations of CH3COOH, evaluated by weight loss and electrochemical techniques, showed marked resemblance. From both tech…
The results of experimental and theoretical investigations of nonlinear acoustic phenomena (nonlinear losses, shift of resonance frequency, generation of the third harmonic, and nonlinear sound-by-sound damping) in polycrystalline zinc nonannealed and annealed resonating rods are presented. The measurements were carri…
In the present paper, the effect of the addition of fine particles 1%wt BaTiO/sub 3/ to plain low-density polyethylene (LDPE) on the short-term dc breakdown strength of LDPE is investigated. The Weibull plots are used to analyze the breakdown test results. This indicates that the addition of BaTiO/sub 3/ to LDPE has r…