Materials Literature
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The effect of macroscopic surface roughness upon the resistivity of thin metal films has been calculated by computer modelling of the form of these films. It is shown that, as a consequence of the tendency for the films to be islandised, the resistivity as a function of decreasing mean film thickness rises well above…
An area in north-central New Brunswick of approximately 20 km 2 , where tors are common, was found to be undisrupted by glaciation. The soils in this area are developed on grus and appear to be of pre-Wisconsin age. In both residual Podzolic and colluvial Brunisolic soils, gibbsite was found to be present in significa…
An investigation has been performed into the general corrosion behavior of metallic materials in acid containing organic solutions. Media effects were investigated and found to considerably affect the dissolution process of metals. The metals and solvents used in this study were: Metals—Zn, Fe, Al, Cr-Ni steel; solven…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTStudy of thermal polymerization of styrene by Raman scatteringB. Chu, G. Fytas, and G. ZalczerCite this: Macromolecules 1981, 14, 2, 395–397Publication Date (Print):March 1, 1981Publication History Published online1 May 2002Published inissue 1 March 1981https://pubs.acs.org/…
The effects of composition, temperature, applied field, and duration of the applied field on the dc resistivity of chromium-doped manganese-zinc ferrites have been studied. From the observed temperature variation of resistivity, activation energy of each sample is calculated. The overall results are discussed in light…
Abstract Most ammonia volatilization studies have focused mainly on specific fertilizers, management, and environmental factors associated with N loss. The objective of this study was to evaluate the influence of particle size of both added and native CaCO 3 and the modifying effects of Fe oxides on NH 3 volatilizatio…
Mn-Al-C alloy for permanent magnets has merit for several reasons: a) carbon stabilizes the metallurgical phases, deformation temperature is high enough for plastic transformation to produce anisotropic τ-phase efficiently; b) useful magnetic energy exceeds the best hexaferrites; the alloy can be more efficient than A…
An extension of the classification of the spectra of neutral praseodymium, based on the analysis of high resolution recordings in the IR and visible ranges, provides new levels of the even configurations 4 f 2 5 d 6 s 2 and 4 f 2 5 d 2 6 s . A parametric interpretation of the fine and hyperfine structures is given for…
The d.c. resistance of amorphous red phosphorus has been measured up to pressures of 90 kbar. At 70 kbar, a transition to orthorhombic black phosphorus was observed. The effect of an initially inhomogeneous microstructure is discussed. At a fixed pressure, a time dependence of the resistance was observed, and this is…
Abstract Partial development of the α form crystals in γ nylon 12 has been found to take place by drawing near the melting point. The confirmation of the α form has been made by X‐ray diffraction, infrared absorption, and differential scanning calorimetry. The amount of the α form varies depending upon the temperature…
Abstract The hevea brasiltensis rubber contains, besides the insoluble branched entities, linear and branched molecules in the soluble fraction. The branching characteristics found by analyzing fractions of different molecular weight of rubber coagulated from freshly tapped latex, stabilized with hydroxylamine hydroch…
Among the Y-Ni compounds, four different behaviours, characteristic of the occurrence of d ferromagnetism in intermetallics have been observed : Exchange Enhanced Pauli Paramagnetism in YNi5 and YNi2, Very Weak Itinerant Ferromagnetism in YNi3, Collective Electron Metamagnetism in Y2Ni17 and Thermal Spontaneous Magnet…
The electrical conduction of 20 µm thick polypropylene films with different crystallinities has been studied at 72°C below 400 kV/cm. The field dependence of the current shows that the conduction mechanism in this polymer is ion hopping. The estimated ionic jump distance strongly depends on the polymer crystallinity,…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSAXS studies of segmented polyether poly(urethaneurea) elastomersG. L. Wilkes and S. AbouzahrCite this: Macromolecules 1981, 14, 2, 456–458Publication Date (Print):March 1, 1981Publication History Published online1 May 2002Published inissue 1 March 1981https://doi.org/10.102…
Single crystals of NaCl, LiF and MgO were deformed at strain rates of 105 s−1 by impacting them with glass and tungsten carbide spherical particles of diameter in the range of 0·4-G l·0 mm. By measuring the incident and rebound velocities and the size of the residual indentation, the dynamic hardnesses of these materi…
The changes in density of specific tissues after administration of intravenous contrast agents is easily detectable by computed tomography and is important in distinguishing normal and pathologic tissues. The time course of these density changes was determined in nine specific tissues in the rat by measuring tissue ra…
A model to predict the forces on conical-nosed penetrators for normal impact into dry rock targets is developed. The target medium is described by a linear hydrostat, a linear shear failure-pressure relation, and the material density. A cylindrical cavity expansion approximation to the target response permits one-dime…
Abstract The course of intermolecular reactions induced by peroxide decomposition in linear polyethylene has been determined and compared with similar reaction systems in which the substrate is a lowmolecular‐weight alkane. Efficiency of intermolecular coupling is 40% for an alkane and 25–30% for the polymer system. C…
Electrostrictive terms have been introduced into the simple Kittel free-energy function for antiferroelectrics. An additional coefficient W is found to be required to take account of the interaction with the sublattice polarizations, and Q and W values have been calculated from experimental data for typical antiferroe…
Abstract Analysis of the distribution of gibbsite in soils and saprolites of Galicia, NW Spain, leads to the conclusion that this mineral is mostly formed by inorganic mechanisms in open, well-drained and desaturated systems in the initial stages of weathering of various aluminosilicates, especially plagioclases. No e…