Materials Literature
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The asymptotic behavior of multichannel parallel relaxation processes for systems with dynamical disorder is investigated in the limit of a very large number of channels. An individual channel is characterized by a state vector x which, due to dynamical disorder, is a random function of time. A limit of the thermodyna…
Abstract Anthraquic conditions were defined in the soil taxonomy primarily for rice paddy soils, but little data have been published on relationships among saturation, reduction, and morphological features for such soils. We studied those parameters in three alternatively flooded and irrigated rice‐growing Alfisols. R…
Substitution of yttrium (${\mathrm{Y}}^{3+}$) in La-Ca-Mn-O perovskites of the ${\mathrm{ABO}}_{3}$ structure markedly affects the crystal structure and lattice constants as well as the resistivity (\ensuremath{\rho}), ferromagnetic transition temperature (${\mathit{T}}_{\mathit{c}}$), and the temperature correspondin…
The influence of surface energies on line resolution in screen printing was studied in this paper. Ink wettability on surfaces is decreased by decreasing the surface energies of substrates-the reduction in wettability improves the line resolution. For such high surface-energy substrates as ceramics, the effective mean…
Cellulose acetate (CA) was melt compounded with two different citric acid esters: triethyl citrate and acetyl triethyl citrate. It was observed, based on the glass transition temperatures, that both plasticizers were miscible with CA. The addition of plasticizer reduced the tensile modulus and increased the elongation…
Two laboratory melts of the standardized nitrogen-rich austenitic stainless steel specified in ISO 5832-9:1992(E) have been characterized with respect to corrosion properties, mechanical properties, and microstructure. The two melts differ essentially in nitrogen concentration, namely, 0.42 and 0.46 wt %, respectively…
Abstract Large‐scale quantum chemical simulations of the diffusion hops of empty cation and anion vacancies, as well as F + and F centers in MgO crystals have been done. The atomic configurations for 224‐site cluster and charge density distribution are analyzed for the equilibrium and saddle‐point configurations durin…
Sensitivity to nickel, cobalt, and chromium is common among the general population. The identification of these sensitivities is generally by the detection of cell-mediated immunity. We have reported previously the use of an indirect enzyme-linked immunosorbent assay method to quantitate metal-specific antibodies in p…
The influence on their mesomorphic behaviour of introducing a carbon-carbon double bond into the chain, central linkage and alicyclic rings in the core of nematic and smectic liquid crystals (LCs) is discussed. Mesogens incorporating a trans-carbon-carbon double bond conjugated with an aromatic ring exhibit high mesop…
Using small‐angle scattering, together with density measurements, X‐ray diffraction, nitrogen adsorption, and both transmission and scanning electron microscopy, the microstructural evolution during sintering in nanostructured ceramic oxides has been studied. The availability of samples with sufficient size and unifor…
Wear and wear transition in silicon carbide ceramics during sliding have been investigated. Three different microstructures, i.e., solid‐state‐sintered silicon carbide, liquidphase‐sintered silicon carbide, and a liquid‐phase‐sintered SiC‐TiB 2 composite, were produced by hot pressing. Wear data and examinations of wo…
The nomenclature of the taxon first recorded as Fragilaria (virescens) v. exigua by Grunow in Cleve & Moeller (1878) is examined with regard to the current botanical name, F. exiguiformis Lange-Bertalot. The distribution of this taxon in relation to pH is described from surface sediment samples collected from more tha…
A large number of incorrect crystal structures is being published today. These structures are proving to be a particular problem to those of us who are interested in comparing structural moieties found in the databases in order to develop structure-property relationships. Problems can reside in the input data, e.g., w…
Electrochemical measurements and constant extension rate tests (CERT) of cold-worked X-52 carbon steel showed stress corrosion cracking (SCC) can be induced in aqueous sulfate (SO42−), bicarbonate (HCO3−), and simulated soil solutions at 50°C. Susceptibility to SCC was at a minimum near the corrosion potential (Ecorr)…
The Raman and infrared (IR) spectra of ethylene carbonate (EC) containing various concentrations of lithium perchlorate have been studied. It was found that both the vibrational frequencies and the relative intensities of the bands related to the ring structure and C=O group of the EC molecule change with the concentr…
Teflon clad and As/sub 40/S/sub 60/ glass clad As/sub 40/S/sub 55/Se/sub 5/ fibers transmitting in the 1-6 /spl mu/m wavelength region have been fabricated in lengths of about 50 m and with minimum losses of 0.098 and 0.65 dB/m, respectively. Short lengths of the Teflon clad fiber possessed a minimum loss of 0.047 dB/…
MOCVD has many promising advantages over physical processes but industrial applications are still sparse, probably because commercial availability of suitable precursors is limited. In this Research News article the stringent requirements for metal‐organic compounds for thermal MOCVD as well as for photo‐MOCVD and MOM…
Abstract For a range of different fillers, silicas and carbon blacks, added to a rubber melt at various concentrations, dynamic moduli in the linear viscoelastic limit have been determined. It is shown that reinforcement is due to hydrodynamic effects and the formation of a secondary particulate structure within the r…
Barley starch was plasticized in a melt mixer using glycerol and water as plasticizers. Plasticizer concentration, time, temperature, and shear were varied, and their effects on the molecular weight of starch and the glass transition temperature and mechanical properties of the mixtures were studied. Depolymerization…
Electromigration reliability of different metallization systems (Al-2%Si, Al-Cu/TiW, Cu, and TiN/Al-2%Si/TiN) and structures (Al-via and W-plug) under bidirectional current stress has been studied in a wide frequency range (from mHz to 200 MHz). The experimental results show that at low frequency, the damage healing f…