Materials Literature
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Careful experimental techniques, especially with synchrotron radiation, give well-resolved diffraction patterns. Remaining overlapping peaks can be separated by profile analysis and profile fitting. The mathematical formalism is given. The derived parameters are: peak positions for lattice constants, integrated intens…
L'agent de surface a pour role de stabiliser la mousse avant gelification. Influence d'agents de surface sur des proprietes de surface de mousses phenoliques
The wetting by a liquid drop of a model mammalian hair fibre is compared with that of a smooth cylindrical fibre. (B. J. Carroll, J. Collodid Interface Sci., 1976, 57, 488). The model considered has a series of axially symmertrical serrations regularly spaced along the fibre length and these are shown to play an impor…
Thermogravimetric (TG) data on reoxidation behaviour of a particular type of sponge iron (coal based sponge iron) are mainly reported in this paper. While emphasis is on isothermal kinetics, some nonisothermal TG data are also presented. The data have been analysed using the reduced time plot and the activation energy…
Abstract Recent research of the well‐drained cerrados (savanna) soils of Brazil suggests that poor root growth associated with inferior crop production is often caused by subsoil Ca deficiency rather than Al toxicity. The present study was conducted to re‐examine this hypothesis and to compare native soil vegetation p…
The effect of a magnetic field applied perpendicular to the helical axis of a cholesteric liquid crystal mixture with positive diamagnetic anisotropy has been studied by laser diffraction and microscopy. A rapid decrease of the field below a threshold H s generates first a metastable periodically striated texture. A f…
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Chlorided Pt/Al2O3 has been subjected to series of consecutive oxychlorination/reduction cycles in which oxychlorination stages in each series involved heat treatment of Pt/Al2O3 at 723, 893 or 993 K in oxygen containing 400 ppm carbon tetrachloride. The quality of resulting Pt dispersion was monitored by infrared and…
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In searching the elements to suppress the intergranular brittleness in molybdenum, TiC addition was found effective. In order to clarify the effect of TiC addition quantitatively, molybdenum bicrystals containing 1.5 mol%TiC were prepared by a floating zone melt technique. The fracture behaviour was measured by a 4-po…
Abstract Das thermische Verhalten von RbGeI 3 wurde unter Verwendung von Röntgenbeugung, Ramanspektroskopie und DTA/DSC untersucht. RbGeI 3 ist tetramorph. In der Kristallstruktur der gelben orthorhombischen LT‐Form (RG P2 1 2 1 2 1 ; a = 10,1441 (8) Å; b = 4,5460(5) Å; c = 16,8438(9) Å), die durch Kristallisation aus…
A simple method which is suitable for determining with reasonable precision the lattice parameters of the crystals with known structure using a 16-bit personal computer and an unsophisticated calculation is described. This procedure is based on the Nelson-Riley extrapolation function and the least-squares analysis. Th…
The effects of maleic and fumaric acids and their mono- and di-anions on the dissolution of calcite in aqueous solution have been studied over a wide pH range (3–8.5) by (i) the channel flow cell method, (ii) etch pit morphology measurements and (iii) the determination of adsorption isotherms. It is established that t…
Abstrac tAn improved model for the atomic oxygen oxidation of silver is presented. The transport of oxygen through the oxide layer is modelled using two transport mechanisms, namely gas flow through micro-pores and Fickian diffusion. Both processes exhibit parabolic growth. The interfacial reaction between oxygen and…
Various NADH model compounds, 1-(X-benzyl)-1,4-dihydronicotinamide (X-BNAH: X = 4-MeO, 4-Me, H, 4-Cl2, and 2,4-Cl2) and 10-methyl-9,10-dihydroacridine (AcrH2), form complexes with metalloporphyrins (FeTPPClO4, FeTPPCl, MnTPPClO4, and ZnTPP; TPP: tetraphenylporphyrin) in dichloromethane or chloroform. For the BNAH–ZnTP…
In order to improve the understanding of pollution or moisture-triggered flashovers a joint four-year test was initiated to evaluate DC insulators under natural pollution and wetting conditions. The main purpose of the test is to establish correlations among flashover, equivalent salt density deposits, and weather, op…
The monoclinic form of LiMgBO 3 has been synthetized and its crystal structure studied by single crystal X-ray diffraction methods. The space group is C 2/ c , Z = 8, with unit cell parameters a = 5.161(1) Å, b = 8.880(2) Å, c = 9.911(2) Å and β = 91.29(2)°. The structure which is isotypic to that of i.a . LiZnBO 3 ,…
Abstract The rheological and thermal properties of poly(vinyl alcohol) (PVA) gels prepared through freezing‐thawing cycles were studied, in order to clarify the relation between structure and functional properties. The breaking strength of PVA gels increases with increasing the degree of saponification (DS), i.e. the…
The chelation of spironaphthoxazine derivatives in the coloured form to divalent metals induced considerable shift of the absorption spectra and significant retardation of the decolouration rate in the dark.
Abstract This article discusses the classifications of high-speed tool steels and describes alloying elements and their effects on the properties of high-speed tool steels. It analyzes the heat treatment of high-speed tool steels, namely, preheating, austenitizing, quenching, and tempering. Surface treatments for the…