Materials Literature
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Transmission electron microscopy studies of the (1−x)Pb(Mg1/3Nb2/3)O3–(x)PbTiO3 [PMN-PT (1-x)/x] crystalline solution have been performed for x=0.1, 0.2, 0.35, and 0.60. Bright-field imaging has revealed a common sequence of domainlike states with increasing x. Normal micron-sized ferroelectric domains were found for…
Zinc sulphide nanoparticles in the size range ∼10–40 Å diameter have been synthesized using the aqueous chemical method. Scanning tunneling microscopy showed that particles are indeed nanosize particles. The size dependent band gap could be varied from a bulk value of 3.68 to 4.5 eV. X-ray diffraction indicated that n…
Chemical vapor deposition using 2-methyl-1,2′-naphthyl ketone as a starting material has been done between 1000 and 600 °C on Ni particles with diameters ranging from 10 to 500 nm. The Ni particles were prepared by annealing Ni thin film deposited on quartz glass substrates. The size of the Ni particle was controlled…
We present a first-principles study of excitonic self-trapping in diamond. Our calculation provides evidence for self-trapping of the core exciton and gives a coherent interpretation of recent experimental x-ray absorption and emission data. Self-trapping does not occur in the case of a single valence exciton. We pred…
Abstract This paper describes the development and testing of a solid, encapsulated scale inhibitor for use in fracturing treatments. Data from laboratory and field tests are reported. Laboratory testing with a continuous flow apparatus has yielded inhibitor release rates under dynamic conditions. The inhibitor was tes…
The phenomenon of Ostwald ripening is examined theoretically for precipitates in solution, crystallites on a substrate, and islands of insoluble surfactant molecules at the liquid–air interface. The classical theory of Ostwald ripening, developed by Lifshitz and Slyozhov and independently by Wagner, employs a continuu…
We have extended a recently introduced united atom model of n-alkanes to investigate the liquid-state dynamics of squalane, a molecule with six, symmetrically placed, methyl side groups. We compare our results with experimental measurements of diffusion in the same system and with experimental and simulation results o…
Chemical treatments similar to those routinely used to extract cellulose from plant biomass caused significant increases in the relative crystallinity index (RCI) of Sig-macell 100 (a commercial cellulose of moderate crystallinity), as measured by x-ray powder diffraction in both the reflectance and transmittance mode…
Exciton effects on conjugated polymers are investigated in the soliton lattice system. We use the Su-Schrieffer-Heeger model with long-range Coulomb interactions treated by the single-excitation configuration-interaction method. The soliton band is present in the Peierls gap of the doped system. There appears a new ki…
Silicon-containing Polymers reflects the growing interest worldwide in this developing field. Silicon polymers are now finding use as moulding materials, rubbers, ceramic precursors, in lithography and reprography as photosensitive materials, as conducting polymers, and in a host of other applications. This book prese…
Abstract Mechanical properties of recycled PP/rubber/filler systems were studied and mechanisms were discussed on the basis of molar mass and molar mass distribution, morphologies, and thermal behavior. Characteristics of recycled PP/rubber/filler depend on degradation of PP and additional components. Recycling proces…
The active site of pig heart citrate synthase contains a histidine residue (H320) which interacts with the carbonyl oxygen of oxaloacetate and is implicated in substrate activation through carbonyl bond polarization, a major catalytic strategy of the enzyme. We report here the effects on the catalytic mechanism of cha…
Abstract A mathematical model that includes crystallization in the spinline and the effect of crystallization on the extensional viscosity and the various physical properties of polypropylene has been developed and used to help in identifying the various factors that can affect the spun yarn characteristics. The model…
Abstract Both as‐molded and annealed poly(ether ether ketone) (PEEK)/poly(ether sulfone) (PES) blends have been prepared by direct injection molding. The system has been found to be immiscible at all compositions; however, as a result mainly of the produced morphology, it surprisingly maintains to a very great extent…
Monoiodotyrosine margatoxin ([125I]MgTX) specifically and reversibly labels a maximum of 0.8 pmol of sites/mg of protein in purified rat brain synaptic plasma membrane vesicles with a dissociation constant of 0.1 pM under equilibrium binding conditions. This Kd value was confirmed by kinetic experiments (Kd of 0.07 pM…
Abstract Morphology and mechanical properties of polypropylene (PP)/high density polyethylene (HDPE) blends modified by ethylene‐propylene copolymers (EPC) with residual PE crystallinity were investigated. The EPC showed different interfacial behavior in PP/HDPE blends of different compositions. A 25/75 blend of PP/HD…
Abstract Silkworm cocoon silk and spider major ampullate (drag line) silk exhibit macroscopic tensile properties that, while impressive in the context of polymer fibers, are highly variable. The variability is linked to the cross‐sectional geometry being nonuniform: silk fiber cross section changes significantly over…
Abstract Styrene‐butadiene rubber (SBR) composites were prepared by incorporating short sisal fibers of different lengths and concentrations into the SBR matrix in a mixing mill according to a base formulation. The curing characteristics of the mixes were studied and the samples were vulcanized at 150°C. The propertie…
PURPOSE: To evaluate the size and shape of commercially available polyvinyl alcohol (PVA) particles and to determine whether they change in size when suspended in nonionic contrast and in a solution of nonionic contrast and absolute alcohol. METHODS: The two-dimensional area and the long and short axis of PVA particle…
Raman scattering in tetramethylammonium tribromocadmate crystals is measured at room temperature and low temperature down to 9 K in the region from 10 to 3400 cm−1. The infrared spectrum in the NIR region is also taken at room temperature to facilitate the identification of the vibrational modes. Efforts are made to i…