Materials Literature
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The crystallization of isotactic polypropylene was studied by DSC method at a standard cooling rate of 10 deg/min. The samples were in the forms of sandwiches comprising polymer films of various thickness and layers of foreign materials. After the crystallization the spherulitic structure of the samples was investigat…
Calderonite, ideally Pb 2 Fe 3+ (VO 4 ) 2 (OH), a new member of the brackebuschite group, has been found in the upper oxidation zone of two Pb-Zn hydrothermal deposits located at Santa Marta and Azuaga, Badajoz province, Spain. Brackebuschite and calderonite probably form a complete solid solution, locally with import…
Ultrafine-grained titanium produced by equal channel angular pressing and subsequent cold rolling is studied by Xray diffraction. It is found that a texture exists in which the hexagonal basal planes are parallel to the longitudinal axis of the billet. The crystallite size distribution and the dislocation structure ar…
Abstract Measurements have been made of the degradation rates for poly(vinyl chloride) (PVC) and nitrocellulose with cellulose acetate (NC) in x‐ray photoelectron spectroscopy. These materials form part of earlier studies published by others to evaluate instrumental degradation factors. In the earlier studies, results…
A comparison analysis has been undertaken to study the effect of different wood fillers on density and mechanical properties of two different types of commercial polyurethane (PUR) foams: low-density flexible foams and high-density rigid foams. The micro-fillers used were based on wood flour particles of size 70-250 m…
We present a numerically efficient steady-state finite-element solver for electromechanical devices incorporating magnetic saturation in which the magnetization of ferromagnetic materials is modeled as a field-dependent equivalent current density. We use a Lagrangian representation of continuum variables, thereby remo…
Mechanical activation and fine comminution of hexagonal oxide ferrimagnets by milling to a nanocrystalline state (ultradisperse powder), followed by sintering, leads to significant changes in the phase diagram, the temperature of synthesis, and the magnetic properties as compared to those of the materials obtained by…
Nanoscale carbon/MgO composite adsorbents have been prepared by chemical vapor deposition (CVD) of carbon over aerogel-prepared nanocrystalline MgO with propylene as the carbon precursor, and by pyrolysis of Mg(OH) 2 aerogels modified with resorcinol. A new textural approach including adsorption methods and HREM has b…
A new naviculoid diatom species, Nupela exotica Monnier, Lange-Bertalot & Bertrand spec. nov., has been discovered in a tropical freshwater aquarium near Orléans (France). It is described on the basis of SEM studies, complemented by LM observations. The diatom flora and water characteristics are particular, since taxa…
The Raman-active phonons in perovskite-like LaMn1−xCoxO3 (x=0, 0.2, 0.3, 0.4, and 1.0) are studied by measuring the Raman spectra at temperatures of 295 and 5 K. The changes in the spectra with Co doping are correlated with the decrease of the orthorhombic distortions. Surprisingly, more phonon lines are observed than…
Abstract Threshold Al KLL Auger electron spectroscopy and K‐edge x‐ray absorption fine structure spectroscopy have been used to examine technical purity (99.5%) aluminium foil before and after chemical treatment that altered the thickness and degree of hydroxylation of the oxidized layer. Comprehensive surface chemica…
Abstract We present a three‐dimensional simulation of scanning electron microscope (SEM) images and surface charging. First, the field above the sample is calculated using Laplace's equation with the proper boundary conditions; then, the simulation algorithm starts following the electron trajectory outside the sample…
The oxidative chemical polymerization of N-methylaniline was studied in hydrochloric acid solution using sodium dichromate as oxidant at 5°C under nitrogen atmosphere. The effect of hydrochloric acid, sodium dichromate and monomer concentration on the polymerization reaction was investigated. The order of reaction wit…
A new copper complex, [Cu(phen)2N3]ClO4 (phen = 1,10-phenanthroline), has been synthesized and characterized by X-ray single-crystal structure analysis. The copper atom is five-coordinated with four nitrogen atoms of two phens and one nitrogen atom of the azide to form an intermediate coordination geometry distorted f…
Diprora haenaensis gen. et sp. nov. Main, an araphid filamentous diatom, is described from a cryptic, pseudoaerial habitat in Kaua'i, Hawaiian Islands. The valve ends of this new diatom have pervalvar extensions of the mantle edges, termed here prows. The frustules are heavily silicified and usually heterovalvar (one…
We show that the structure of transparent oxy-fluoride glass-ceramics formed by heat treatment of glasses of typical composition 32(SiO 2 ):9(AlO 1.5 ):31.5(CdF 2 ):18.5(PbF 2 ): 5.5(ZnF 2 ):3.5(ErF 3 ) mol% consists of ∼ 12 nm diameter, Er 3+ -doped, β-PbF 2 nano-crystals embedded in a silica-based glass network and…
We propose a simple procedure for designing an integrated single-chip grating-based thin-film filter. A simulation from a rigorous coupled-wave analysis shows that structural adjustment based on the effective medium theory can achieve the desired integration without notable performance degradation. Our spectropolarime…
Abstract Poly( dl ‐lactide) (PLA) and two of its random copolymers with glycolic acid, poly( dl ‐lactide‐ co ‐glycolide) (PLGA) with 75/25 and 50/50 component ratios of lactide/glycolide were blended with poly(ethylene oxide)/poly(propylene oxide)/poly(ethylene oxide) (PEO–PPO–PEO) triblock non‐ionic surfactants, know…
Heterogeneous platinum catalysts (Pt/SiO 2 ) obtained by the sol-gel process at pH 3 and 9 have been used in the hydrosilylation reaction of 1-alkynes using various silanes. Once the catalysts were activated they were used in the hydrosilylation of 1-alkynes after a short induction period. The product distribution was…
The oil sands industry in Alberta (Canada) has developed the composite tailings (CT) process to reduce the fluid fine tails resulting from the processing of oil sands. This process uses a chemical coagulant (gypsum or alum) to produce aggregated fines (clay), so they are retained with the coarse sand fraction of the e…