Materials Literature
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In order to analyse the bending rigidity of woven fabrics in any direction, the authors have theoretically derived a versatile equation (19) without neglecting twist effects of constituent yarns. Assuming that yarns are elastic and homogeneous and no interaction exists in yarns, the twist effects could be described as…
Abstract The contribution of exchangeable K to the K uptake by ryegrass in the field was studied on soils of the North Island whose dominant clay minerals were considered not to contain non‐exchangeable but plant available K. Six were derived from basalt or andesitic volcanic ash and 4 from sedimentary rock. On 8 site…
Abstract The effect of orientation on the structure and transport properties of high‐density polyethylene film has been studied. Microstructure was characterized using small‐angle light scattering, birefringence, and wide‐angle x‐ray scattering. Water vapor and oxygen transmission rates were determined as a function o…
A series of PDMS networks were prepared by endlinking reaction of α, ω-functional precursor polymers. The erosslinking reaction and the influence of incomplete reaction on formation of pendent chains are discussed. Equilibrium concentration and light spectroscopy measurements have demonstrated a decrease of the mesh s…
Treatment with mercury(II) acetate of metal complexes of porphyrins bearing peripherally unsubstituted positions gives the corresponding mercurated derivatives; using the palladium–olefin reaction, this observation is exploited in the synthesis of coproporphyrin III tetramethyl ester (2), harderoporphyrin trimethyl es…
The pyroelectric coefficient p of the mm2 phase of Fe-I and Cu-Cl boracite has been measured from 20 C upwards. The quasistatic Byer-Roundy technique applied to Fe-I boracite yielded p = 0. 01 x 10-8Ccm-2K-1 at 20°C, rising to 0. 1 x 10-8Ccm-2K-1 at 63°C; the extrapolated value for TC (72°C) is ∼ 1. 9 x 10-8Ccm-2K-1.…
The electron spin resonance of MnO42− has been studied at 4.2 K in single crystal K2SO4. The principal values of the g and A tensors are gx=1.9757, gy=1.9696, gz=1.9445, Ax=−21.0×10−4 cm−1, Ay=−25.5×10−4 cm−1, and Az=−147.6×10−4 cm−1. Az and gz make an angle of 7.8° and the only element of symmetry in the MnO42− tetra…
Les caractéristiques structurales et chimiques des aluminates et silicates hydratés contenant du nickel — caractéristiques qui, pour la plupart, ont été mises en lumière au cours de la dernière décade — sont passées en revue. La grande majorité de ces minéraux ressemblent aux silicates hydratés magnésiens avec substit…
Nickel was systematically substituted for cobalt in Waspaloy. M'echanical test results indicate that lower cobalt has little effect on tensile properties, but adversely affects creep rate and stress rupture life. Phase extraction studies found slight decreases in gamma prime volume fractions and increased M'23C6 carbi…
Related optical and detector properties of the PbS-Si heterojunction (HJ) are presented and discussed. A direct optical bandgap at 300 K of 0.44 eV has been measured for PbS-Si versus 0.42 eV for PbS-sapphire. The HJ photocurrent frequency response has been determined to consist of two waveform components: Type A, a "…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStudies on Thermal Degradation of Synthetic Polymers. 12. Kinetic Approach to Intensity Function Concerning Pyrolysis Condition for Polyethylene Low PolymerTakashi Sawaguchi, Tatsuo Inami, Takeshi Kuroki, and Tadashi IkermuraCite this: Ind. Eng. Chem. Process Des. Dev. 1980,…
Treatment of heptaethyl(vinyl)porphyrin (1) with acidified nitrite solution gives a greenish porphyrin which is shown to be 21(E)-3,7,8,12,13,17,18-heptaethyl-2-(2-nitrovinyl)porphyrin, (2). Protoporphyrin dimethyl ester (3) similarly treated gives a mixture of compounds, including two greenish porphyries which are fo…
An apparatus was deviced for the analysis of CO2, CO and NO in the small amount of the gas sampled around the coke specimen during combustion. The conversion ratio of organic nitrogen in coke to NO was calculated from the analytical results of these gases.According to the analysis of the conversion ratio, the reaction…
Glycoside H2, C56H92O25, [α]D -25.9°(MeOH), which causes marked potentiation of the effect of NGF (nerve growth factor), was isolated from Bei-Wujiapi (the cortex of Periploca sepium BGE., Asclepiadaceae) and its chemical structure was established to be ⊿5-pregnene-3β, 16α, 20α-triol 3-O-[2-O-acetyl-β-D-digitalo…
57Fe Mössbauer studies of HoFe2 and DyFe2 at various temperatures exhibit a small but definite asymmetry in the peak positions as well as in the peak widths. The symmetry in the line widths suggests that the magnetization deviates from [100] direction, whereas the asymmetry in the peak positions can arise either due t…
Abstract Single crystals of rare‐earth (La‐Nd, Sm, Gd) and Y dititanates have been grown either by the method of direct high frequency heating in cold container or/and floating zone optical technique. The crystals Ce 2 Ti 2 O 7 and Pr 2 Ti 2 O 7 belong to the structural type of Ca 2 Nb 2 O 7 and possess dielectric and…
Cu-Pd-Ag alloys were aged with the isochronic ageing method after quenching from the solid solution temperature into ice water. The hardness test, electrical resistivity measurement and X-ray diffraction analysis were performed to investigate the ageing characteristics. It was found that there were three different har…
Polycrystalline films of BaTi03 with ferroelectric properties are regularly observed for films thicker than 1000 Å which have been rf-sputtered deposited at 5 Å/min onto silicon substrates at temperatures above 500°C. A 2000 Å thick film deposited under these conditions typically exhibits a counter-clockwise hysteresi…
New data on the physical and chemical characteristics of the UICC standard reference samples are presented. Aspects such as fibre length and diameter distribution, composition and special electrical and magnetic properties are covered. The possibility of preparing samples with graded characteristics is raised. A new e…
An experimental study of the residual stresses and fatigue properties of ground En 31 steel specimens is described. The individual grinding parameters (wheel types and speed, feed, dressing, and lubricant) are grouped into three categories: abusive, conventional, and gentle grinding. In the absence of high temperature…