Materials Literature
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To obtain powder with a composition of 3 mol% Y 2 O 3 –97 mol% ZrO 2 , a process of Y‐Zr oxalate powder production has been optimized, to produce an oxalate with minimal particle size. The methodology of the nonisothermal decomposition of Y‐Zr oxalate has been explained. Characteristics of the nonisothermal decomposit…
Accurate quantitative X‐ray diffraction analysis of SiC‐based ceramics is difficult because of the significant overlap of the Bragg reflections from the different SiC polytypes. In this regard, the Rietveld method is a powerful tool for the accurate and precise analysis of the phase/polytype compositions in these mate…
Hydrogenated carbon nitride films were deposited by reactive dc magnetron sputtering in mixed Ar/N2/H2 discharges at temperatures of 100 and 350 °C. The total pressure was kept constant at 0.33 Pa and the gas mixtures were varied in order to study the effect of the hydrogen on the resulting film structure and properti…
Brain extraction of (18)F-labeled 2-fluoro-2-deoxy-D-glucose (FDG) was significantly higher in pentylene tetrazole (PTZ)-treated rats (32 +/- 4%) than controls (25 +/- 4%). The FDG permeability-surface area product (PS) was also significantly higher with PTZ treatment (0.36 +/- 0.05 ml. min(-1). g(-1)) than in control…
The effects of the molecular mass of B-site ions of Pb(B ′ B ′′ )O 3 –PbTiO 3 (B ′ =Mg, Zn, Ni, Sc, In and Yb; B ′′ =Nb and Ta) and Pb(B, Ti)O 3 (B=Zr, Hf and Sn) piezoelectric materials on the electromechanical coupling factors were investigated. The relationship between the electromechanical coupling factor k p near…
Polycrystalline In2O3:Sn (ITO) films have been prepared by reactive radio frequency diode sputtering of an oxidic target using various oxygen/argon mixtures. They mostly contain more oxygen than the ideal crystal. When deposited at low pressure, the crystals have an expanded lattice (up to 3.5%) and, for small oxygen…
We report low temperature specific heat measurements of ${\mathrm{Pr}}_{1\ensuremath{-}x}{\mathrm{Ca}}_{x}{\mathrm{MnO}}_{3}$ $(0.3<~x<~0.5)$ and ${\mathrm{La}}_{0.5}{\mathrm{Ca}}_{0.5}{\mathrm{MnO}}_{3}$ with and without applied magnetic field. An excess specific heat, ${C}^{\ensuremath{'}}(T),$ of nonmagnetic…
Dielectric beta relaxation in a pyridine-toluene solution is studied close to the glass transition. Loss peak frequency and maximum loss both exhibit thermal hysteresis. An annealing-state-independent parameter involving loss and loss peak frequency is identified. This parameter has a simple Arrhenius temperature depe…
Most bacterial proteins are stable, with half-lives considerably longer than the generation time. In Escherichia coli, the few exceptions are unstable regulatory proteins. The results presented here indicate that the first enzyme in methionine biosynthesis - homoserine trans-succinylase (HTS) - is unstable and subject…
The combination of copper perchlorate, 2,3-pyrazinedicarboxylate (pzdc) and one of pyrazine (pyz), 4,4‘-bipyridine (bpy), or trans -1,2-bis(4-pyridyl)ethylene (bpe) yields a series of Cu complex-assembled compounds [Cu 2 (pzdc) 2 (PL)· x H 2 O] n (PL = pyz, bpy, or bpe). These compounds were characterized by elemental…
BACKGROUND: The favorable properties of lanthanide chelates compared with conventional fluorescent probes have attracted considerable interest. A Eu(3+) chelator, 4,7-bis(chlorosulfophenyl)-1, 10-phenanthroline-2,9-dicarboxylic acid (BCPDA), has been synthesized previously. METHODS: We here describe immunoassay, immun…
The syntheses of soluble windmill and grid porphyrin arrays through the AgI-promoted coupling reaction of 1,4-phenylene-bridged linear porphyrin arrays, which are comprised of a central ZnII beta-free porphyrin and flanking peripheral NiII beta-octaalkylporphyrins, are described. The coupling reaction is advantageous…
The effects of low-temperature stress on the glycolytic activity of the lactic acid bacterium Lactococcus lactis were studied. The maximal glycolytic activity measured at 30 degrees C increased approximately 2.5-fold following a shift from 30 to 10 degrees C for 4 h in a process that required protein synthesis. Analys…
A petromimetic (geological–analog) approach is applied to the design of alumina‐fiber‐reinforced glass‐ceramic‐matrix composites that use a refractory, trioctahedral fluoromica fiber–matrix interphase and feldspar matrixes. Studies of the solid‐state reaction couples between these silicate phases are pursued to addres…
The structural properties of As–Se–S glass system were investigated by x-ray absorption spectroscopy (XANES and EXAFS) using synchrotron radiation. A preliminary characterization by x-ray powder diffraction, differential scanning calorimetric and thermogravimetric measurements was also carried out. The changes in glas…
A new orthorhombic polar variety of Pb-hilgardite containing Na + and HOCl 2− ions in the cavities of the framework has been prepared by hydrothermal synthesis. A correlation between the structural features and nonlinear-optical properties of the crystals is discussed. Similar to the hexaborate group, pentaborates wit…
This paper proposes a new Measurement Standardization Procedure to measure and quantify the acoustic noise produced by power transformers in audio and video equipment under normal and adverse mains conditions. These conditions and the physical mechanisms that cause the noise are discussed. A new measurement set up and…
Relaxor-like dielectric behavior, analogous to that found in lead magnesium niobate, has been induced in the polar dielectric barium magnesium niobate (BMN). In BMN, the dielectric constant was increased and the temperature of the maximum dielectric constant was shifted to a lower temperature with a decrease in measur…
Chromium-doped zinc oxide thin films were deposited using the spray pyrolysis technique. In all cases 15 at. % of chromium in solution was used. Under diluted HCl, a low etching rate in ZnO:Cr thin films is obtained, as compared to undoped ZnO. As-deposited and vacuum-annealed films show a high resistivity. X-ray diff…
High-temperature polyimide composites with low and stable dielectric properties were produced by thermally curing prepolyimide moulding compounds which were prepared by the wet impregnation of chopped short quartz fibres with a PMR-II polyimide matrix resin solution, followed by the evaporation of the solvent with vig…