Materials Literature
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Magnetic properties of single crystalline Ga1−xFexSe have been measured. This material is in the new class of diluted magnetic semiconductors based on the III–VI semiconductors. The magnetization versus field for an x=0.05 sample deviates from the linear response seen previously in Ga1−xMnxSe and Ga1−xMnxS and reaches…
Hyperbranched aromatic polyamides and copolymers were prepared by direct polycondensation in the presence of condensation agents. Three strategies were described: (1) self-polycondensation of AB x -type monomers, (2) copolymerization of AB 2 and AB monomers and (3) polymerization of A 2 and B 3 monomers. The self-poly…
The morphology of the diglycidyl ether of bisphenol-A/poly(3-aminopropylmethylsiloxane) (DGEBA/PAMS) reactive blends was studied by fluorescence techniques as a function of the initial composition. Some fluorescence results were compared with those from optical and electron microscopy investigations. Several morpholog…
The growth of (010)-oriented CrO2 thin films on Al2O3(0001) substrates leads to a higher grain boundary density than the growth of (100)-oriented CrO2 thin films on isostructural TiO2(100) substrates. For both types of films an intrinsic linear contribution to the high field magnetoresistance (MR) due to spin disorder…
The need to destabilize foams and control their formation arises in many industrial processes. Mechanical foam breakers, mechanical vibration and ultrasonic vibration are examples of physical destructive techniques which do not suffer from the drawbacks associated with the use of chemical antifoams and defoamers. This…
Frozen-in phason fluctuations in single grains of icosahedral Al-Pd-Mn quasicrystals have been studied by high-resolution coherent X-ray scattering. Bragg peak widths scale as expected for a distribution of uniform phason strains. Strong relaxation of the uniform phason strain is observed after sample annealing. Large…
Low impurity content is the essential requirement to many applications of vitreous arsenic chalcogenides as a material for optoelectronics. Investigations carried out in last ten years in-creased the knowledge volume about the nature and origin of impurities in chalcogenide glasses, their effect on glass properties, e…
The replacement of organometallic rhenium species (e.g., CH(3)ReO(3)) by less expensive and more readily available inorganic rhenium oxides (e.g., Re(2)O(7), ReO(3)(OH), and ReO(3)) can be accomplished using bis(trimethylsilyl) peroxide (BTSP) as oxidant in place of aqueous H(2)O(2). Using a catalytic amount of a prot…
Abstract The essential work of fracture (EWF) method has aroused great interest and has been used to characterize the fracture toughness for a range of ductile metals, polymers and composites. In the plastics industry, for purposes of practical design and ranking of candidate materials, it is important to evaluate the…
This new architectural class of macromolecules has received substantial attention during the past decade. Three dendritic subclasses, which include: (a) random hyperbranched (i.e. one-pot AB x polymerizations), (b) dendritic grafted (i.e. Combburst® polymers) and (c) regular dendrons/dendrimers (e.g., Starburst® dendr…
In the present work, electrochemical noise (EN) was measured in three different types of experimental set-ups in order to obtain and compare various types of corrosion. Simultaneously with EN measurements, a parallel technique was used, regarding the type of experimental set-up: a computer visualization system combine…
Abstract Ultrasonic degradation of poly(methyl methacrylate) (PMMA) was carried out in several solvents and some mixtures of solvents. The time evolution of molecular weight distribution (MWD), determined by gel permeation chromatography, is analysed by continuous distribution kinetics. The rate coefficients for polym…
A new kink diimide-dicarboxylic acid, 2,2-bis[4-(4-trimellitimidophenoxy)phenyl]diphenylmethane (BTPDM), was synthesized by the condensation reaction of bis[4-(4-aminophenoxy)phenyl]diphenylmethane (BAPDM) with trimellitic anhydride. A series of new poly(amide-imide)s were prepared by direct polycondensation of BTPDM…
The adsorption behavior of a hydroxypropyl methyl cellulose (HPMC) polymer in aqueous suspensions of alumina, silica, kaolin, and talc powders, two‐component combinations, and one three‐component combination was determined. Powders were well characterized by chemical analysis, XRD, DRIFT, SEM, particle size, surface a…
Abstract CuS millimeter-scale tubular crystals were synthesized for the first time via a hydrothermal method at 185 °C. A possible growth mechanism of CuS tubular crystals was proposed.
A new theory of multilayers with enhanced normal reflectance has been developed based on the superposition of a few layers of various different radiation-absorbing materials. Every layer in the multilayer had a subquarterwave optical thickness. The theory was developed for materials with small refractive-index differe…
Londonite, (Cs,K,Rb) Al 4 Be 4 (B,Be) 12 O 28 , is the Cs-dominant analogue of rhodizite. It occurs with rhodizite at Antandrokomby, a dike of granitic pegmatite in the Manandona valley, Antsirabe region, and at Ampanivana and Antsongombato, in the Betafo region south of Mahaiza, all in Madagascar. Londonite occurs in…
SummaryThe rate at which chloride ions diffuse from archaeological iron into a treatment solution depends on how the chloride ions are initially distributed in the corrosion layer. This paper compares solutions of the diffusion equation for two limiting cases: (1) where the chloride ions are initially spread uniformly…
Inspired by Archaebacterial lipids, transmembrane probes anchor a sensing fluorescent polyene with Ångström resolution deep within a lipid layer. These new bolaamphiphiles are obtained in good yields from a double cross-coupling between esters with a terminal acetylene group and conjugated 1,ω-dihalopolyenes, followed…
The magnetotransport properties of single crystal trilayers 60 Å Co2MnGe/NM/30 Å Co2MnGe where NM is a nonmagnetic spacer material has been studied. The samples were grown by molecular beam epitaxy on GaAs (001) substrates. The 2 to 1 ratios in thickness of the Co2MnGe layers allows for the easy determination of which…