Materials Literature
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The perovskitelike transition-metal oxide ${\mathrm{Gd}}_{1\ensuremath{-}x}{\mathrm{Sr}}_{x}{\mathrm{TiO}}_{3}$ is investigated by measurements of resistivity, specific-heat, and electron paramagnetic resonance (EPR). Approaching the metal-to-insulator transition from the metallic regime $(x>~0.2),$ the Sommerfeld…
La 1− y Sr y Fe 1− x Al x O 3−δ perovskites were studied as potential materials for solid‐oxide fuel cell (SOFC) cathodes. The phase relations in the LaFeO 3 –SrFeO 3−δ –LaAlO 3 system were investigated by X‐ray powder diffraction analysis. The defect structure of the La 1− y Sr y Fe 1− x Al x O 3−δ perovskites was in…
The infrared (IR) and Raman spectra of propylene carbonate (PC) containing various concentrations of LiClO4 have been measured and analyzed. The difference in spectra of PC with and without LiClO4 was attributed to the interaction of the PC molecules and lithium ions. This interaction occurs mainly on the carbonyl oxy…
In the early 1960s, Werner Von Braun and others recognized the need for a nuclear rocket for sending humans to Mars. The great distances, the intense radiation levels, and the physiological response to zero gravity all support the concept of using a nuclear rocket to decrease mission time. These same needs have been r…
Two series of p/p and o/o type iron(III)-metal-free porphyrin dimers were synthesized and characterized. The dimers consist of a ferric porphyrin and a free-base porphyrin, covalently linked with an alkoxy chain - O ( CH 2 ) n O -(n = 2–10) at the para and ortho position of two phenyl rings. The ferric paramagnetic ef…
The scattering mechanisms of carriers in natural diamond are investigated theoretically, based on the experimental low-field mobility data. The calculated values of low-field mobility are compared with published experimental data. Three types of intervalley phonon scatterings (zero-order) and acoustic phonon scatterin…
The results of measurements of the dynamic yield stress and the ultimate strength of aluminum single crystals in the temperature range from 15 to 650°C, which is only 10°C lower than the melting point, are presented. The measurements are made on samples under the action of plane shock waves with a pressure up to 5 GPa…
The effect of strain rate on the yield strength and fracture toughness of mild steel was studied in the strain rate range 10-5–102 s-1. The lower yield strength was found to be independent of strain rate in the range 10-5–10-3 s-1. Beyond this strain rate, the lower yield strength was found to vary linearly with logar…
1. We report the first measurements to be made on the effects of hydration on the mechanical properties of commercially-prepared duck down feathers. Tensile tests were performed, to failure, on isolated barbs of down feathers at 50% RH and with fully-hydrated (wet) feathers. 2. The Young's modulus (stiffness) and ulti…
Abstract This investigation describes the elastomer—filler interaction and its formation mechanism using solid state high-resolution, high-speed 1 H magic-angle spinning nuclear magnetic resonance (NMR) spectroscopy. Pulsed NMR measurements were carried out on pure styrene-butadiene rubber (SBR), and solvent extracted…
We have designed and tested subwavelength diffractive optical elements consisting of surface-relief gratings made by microcontact printing of self-assembled monolayers. The first device is a beam deflector for 1.55-mum operation consisting of a surface-relief grating made up of eight pillars over one period (9.3 mum)…
A method of sample assembly for four-probe resistivity measurements on fragile organic single crystals using a diamond anvil cell is presented. A procedure to keep insulation between the metal gasket and four leads of thin gold wires bonded to the sample crystal by gold paint is described in detail. The resistivity me…
Methods have been developed to determine by Raman spectroscopy the epoxide conversion in a 4,4'-diaminodiphenylsulfone (DDS)-cured epoxy resin as well as in blends of this resin with copolyethersulfone thermoplastic. The proposed spectral treatments consisted of a peak ratio method and of multivariate analysis. The Ra…
SUMMARY Time–temperature–transformation (TTT) diagrams have been determined for high-lime (10.2%) and moderate-lime (5.2%) bulk raw materials from the Peterborough Member of the Oxford Clay Formation of King’s Dyke [TL 525 297] and Orton [TL 517 293] brickworks. Study of the chemistry and mineralogy of the brickclays…
The kinetics of spherulitic crystallization in fiber reinforced thermoplastics was determined by means of the theoretical model based on the statistical approach and by and the computer simulation of spherulitic crystallization. The computer simulation of the spherulites nucleation and growth was performed to verify t…
Using computer-controlled pulsed laser deposition, high quality SrMoO3 thin films have been epitaxially grown on SrTiO3 (001) substrates. A growth interruption technique was employed for better epitaxy, and layer-by-layer growth was obtained by the intensity oscillations of reflection high-energy electron diffraction.…
Abstract The effect of aluminum powder on the properties of natural rubber composites containing high abrasion furnace black (HAF), general purpose furnace black (GPF), acetylene black, china clay and precipitated silica was studied. In all cases the total filler content including aluminum powder is fixed at 40 parts…
Vanadium oxide (VO x ) films intended for use in uncooled IR microbolometric matrices were deposited by reactive magnetron sputtering on silicon substrates. Optimum deposition conditions were determined, which provide for the obtaining of films possessing a current 1/ f noise level 3–10 times lower, extended dynamic r…
Abstract Different metallic substrates such as beryllium, aluminium, silicon and silver were rigorously tested in all aspects of energy‐dispersive electron probe x‐ray microanalysis of single particles, including the semi‐quantitative determination of low‐ Z elements. The effect of the collecting substrate on the capa…
The P-supplying power of the fine-textured soils from Abitibi-Temiscaming (Quebec, Canada) has never been investigated. Anion exchange membranes (AEM), the electro-ultrafiltration (EUF) technique and chemical extractions were used to describe their P status. Phosphorus was desorbed from four soils that had received 52…