Performance of acrylate-poly(ethylene oxide) polymer electrolytes in lithium batteries

Results for the performance of lithium/Mn0₂ batteries containing solid polymer electrolytes based on poly(ethylene oxide) blends with some acrylic derivatives are presented. The ionic conductivities of the electrolytes are promising for battery application. It was found, however, that interfacial phenomena impair the battery efficiency. Impedance spectroscopy shows resistive limitations at the anode interface of the batteries, caused either by formation of an electrically distinguishable resistive layer or by chemical interaction between the polymer and lithium, influencing, most probably, the kinetics of the lithium oxidation reaction.     

Influence of n-alkanes on wettability and zeta potential of quartz

Contact angles were measured in the following systems: quartz/water droplet/saturated vapor of water + n-alkane and quartz/water droplet/saturated vapor of n-alkane. The alkanes tested were from hexane to pentadecane. In both systems non-smooth changes of contact angle as a function of the chain length were observed. These changes are similar to the zeta-potential changes measured previously for two different samples of quartz in the quartz/n-alkana/water system. On the basis of the results and calculations it is suggested that the observed non-smooth changes of contact angle are due to similar changes in film pressures of the water and n-alkanes.     

影响掺矿渣的钢纤维砼强度的主要因素

研究结果表明 :水胶比、胶凝材料用量、钢纤维掺量、矿渣代水泥量对钢纤维砼强度影响显著。当矿渣取代水泥 10 %时 ,钢纤维砼强度最高。经试验选择出一个具有良好和易性和较高强度 (118MPa)的钢纤维砼配合比 ,为掺磨细矿渣的中含量超短异形钢纤维砼的设计和施工提供了试验依据     

Effect of hot pressing on processing and properties of BBN ceramics

BBN (BaBi₂Nb₂O₉) is very interesting and promising lead free material with relaxor properties in capacitors, sensors and actuators.     

Synthesis of unsaturated polyesters of increased solubility in styrene

The present study presents the synthesis of unsaturated polyester resins using only one glycol i.e., ethylene glycol. Polyesters of inorganic solubility in styrene were prepared. Properties of the resins in the noncrosslinked state in the process of crosslinking and after curing were studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 3143–3150, 2006     

Efficient computer implementation of the renormalized coupled-cluster methods: The R-CCSD[T], R-CCSD(T), CR-CCSD[T], and CR-CCSD(T) approaches

The recently proposed renormalized (R) and completely renormalized (CR) coupled-cluster (CC) methods of the CCSD[T] and CCSD(T) types have been implemented using recursively generated intermediates and fast matrix multiplication routines. The details of this implementation, including the complete set of equations that have been used in writing efficient computer codes, memory requirements, and typical CPU timings, are discussed. The R-CCSD[T], R-CCSD(T), CR-CCSD[T], and CR-CCSD(T) computer codes and similar codes for the standard CC methods, including the LCCD, CCD, CCSD, CCSD[T], and CCSD(T) approaches, have been incorporated into the gamess package. Information about the main features of this new set of CC programs is provided.     

Flux Jumps and H-T Diagram of Instability for MgB2

We present a study of magneto-thermal instabilities in polycrystalline MgB₂ superconductor, by magnetic hysteresis loop measurements and by investigations of magnetic flux dynamics with a miniature Hall probe. Temperature and magnetic field ranges where the flux jumps may be observed have been determined. On the basis of measurements of the magnetic flux dynamics, an average magnetic diffusivity describing the process of the flux jump is estimated. This parameter is compared with the thermal and magnetic diffusivities calculated on the basis of available data for thermal conductivity, heat capacity and resistivity. It is shown that the estimated value of the field of the first flux jump is influenced significantly by the field dependence of specific heat. In order to explain the observed phenomenon, the temperature reached by the sample during the flux jump at different magnetic fields is calculated.     

Effect of temperature on the strength and conductivity of a deformation processed Cu-20%Fe composite

The high temperature (22–600 °C) properties were evaluated for a Cu-20%Fe composite deformation processed from a powder metallurgy compact. The ultimate tensile strengths decreased with increasing temperature but were appreciably better than those of similarly processed Cu at temperatures up to 450 °C. At 600 °C, the strength of Cu-20%Fe was only slightly better than that of Cu as a result of the pronounced coarsening of the Fe filaments. However, at temperatures of 300 and 450 °C, the strength of Cu-20%Fe is about seven and six times greater, respectively, than that of Cu, as compared to about a two fold advantage at room temperature. Therefore, Cu-20%Fe composites made by deformation processing of powder metallurgy compacts have mechanical properties much superior to those of similarly processed Cu at room temperature and at temperatures up to 450 °C. The pronounced decrease in electrical conductivity of deformation processed Cu-20%Fe as compared to Cu is attributed to the appreciable dissolution of Fe into the Cu matrix which occurred during the fabrication of the starting compacts where temperatures up to 675 °C were used. While the powder metallurgy compacts used for the starting material for deformation processing in this study did not lead to a high conductivity composite, the powder metallurgy approach should still be a viable one if processing temperatures can be reduced further to prevent the dissolution of Fe into the Cu matrix.     

Analytical determination of intrinsic permeability of synthetic nonwoven filter fabrics

In this paper an analytical method for determining the permeability of nonwoven filter fabrics is presented. The derived formula shows that the intrinsic permeability, fully characterizing the porous medium, depends on fabric porosity, n, fibre diameter, d, and a shape factor determined experimentally.