Materials Literature
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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…
Dips were observed in the distribution curves of the deposition rates of ZnO films prepared both by planar diode and by planar magnetron sputtering. These dips are ascribed to high-energy neutral atoms bombarding the films. The influence of high-energy neutral atoms on the mixed orientation of ZnO film is also investi…
Summary Estimates of rain drop impact stress were made from measurements of the penetration of water drops through nylon meshes, from analysis of cine photographs of splash and from the output of a force transducer. Results indicated maximum stresses of 2–6 MPa acting for about 50 microseconds on the perimeter of a ci…
The Bi 2 O 3 ‐PbO phase diagram was determined using differential thermal analysis and both room‐ and high‐temperature X‐ray powder diffraction. The phase diagram contains a single eutectic at 73 mol% PbO and 635°C. A body‐centered cubic solid solution exists above ∼600°C within a composition range of 30 to 65 mol% Pb…
Adsorption of electron acceptors on partially reduced TiO 2 leads to the localization of mobile conduction band electrons which is indicated by the appearance of an ESR signal with g = 2.003. The localization process is accompanied by an electron transfer from donor centers in reduced TiO 2 (Ti 3+ ions) to adsorbed mo…
The strength of diamond is usually measured using an indentation technique. It is shown that the values obtained by previous workers for good quality diamond are reasonably consistent if they are all calculated with the same chosen values of modulus and Poisson ratio. By monitoring the extent of crack growth from bene…