Materials Literature
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The stopping power of $K$-shell electrons for large incident particle energies is calculated in this paper, adding to and correcting previous work on the subject. A definition is given for the average ionization potential of an atom independent of the energy of the incident particle. An integral representation is deri…
Abstract A procedure has been developed for preparing reproducible specimens of cuprous oxide at the oxygen-poor limit of its composition range. The electrical conductivity and thermoelectric power of such specimens were measured simultaneously, and related to temperature within the range 20 to 1030° C. The conductivi…
Abstract Using methods of modern field theories a canonical transformation of the Hamiltonian of free electrons in the field of the lattice vibrations is performed. This transformation takes account of the bulk of the interaction of the electrons with the vibrational field and leads to a renormalization of the velocit…
Conditions favoring the formation of the ring discharge, and changes in the electrical characteristics which it brings about, are discussed. A theory is developed which seeks to explain the formation of the ring in terms of field distortion caused by negative space charges in the gap. This requires a change of view on…
Samples of skin from three sheep (Ryeland, Lincoln, and Merino) were sectioned, and measurements made of the diameters and spatial relationships of the wool fibres. It has been shown that in all three samples a negative correlation occurred between the size of a fibre and the number, size, and distance of the fibres a…
Abstract Different mixing conditions were employed to obtain vulcanizates, varying only in degree of carbon black dispersion, with natural and synthetic rubbers, using a single sample of a commercial grade HAF black. Light transmittance measurements on dilute solutions of dissolved unvulcanized stocks prepared by an i…
Lattice constants and temperatures corresponding to maximum dielectric permittivity were investigated for compositions in the barium titanate‐rich portion of the system barium titanate–barium stannate–strontium titanate. Substitution of tin for titanium increases the lattice constant at room temperature, and substitut…
Abstract A theoretical description is given for the propagation of longitudinal plane waves of large lateral extent in solids, for waves of plastic as well as elastic strain. The importance of the hydrostatic compressibility in determining the nature of the waves is brought out. The results are illustrated by a comput…
1 Im System Lanthanoxyd–Uranoxyd tritt eine Fluoritphase von 33–70 Mol-% LaO1,5 auf; die Gitterkonstante steigt dabei von 5,462 auf 5,543 kX für den Michkristall mit 68,0 Mol-% LaO1,5. Nach der an Lanthanoxyd reichen Seite tritt der C-Typ der Sesquioxyde auf, der durch die anomale Mischkristallbildung bis 1200° C best…
The resistance of single textile fibers and assemblies of these fibers has been studied because of its relation to the effects of static electricity in fibrous materials. An apparatus has been con structed to measure resistances of fibers and assemblies from 10 8 to 10 16 ohms at specified tem peratures and relative h…
An equation relating the diffuse reflectance of crystalline powders to particle size, index of refraction, and absolute optical absorption coefficient is derived. Absorption spectra calculated by means of this equation from diffuse reflectance of KCl:Tl, KBr:Tl, and didymium glass are shown to be in satisfactory agree…
The butyric acid forming bacteria, if continuously subcultured, undergo certain changes which affect morphological as well as physiological features. These changes were described as early as 1893 by Grimbert as degenerative changes of his cultures. Winogradsky (1902) found that his Clostridium pasteurianum ceased to f…
The thermal conductivities of polycrystalline alumina, beryllia and graphite have been measured between 2° K and room temperature The first two are dielectric solids but, even in the graphite specimens, the electronic contribution to the heat conduction is very small It is shown that the phonon mean free path is limit…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Experimental Determination of the Surface Tension of Magnesium OxideGeorge Jura and Carl W. GarlandCite this: J. Am. Chem. Soc. 1952, 74, 23, 6033–6034Publication Date (Print):December 1, 1952Publication History Published online1 May 2002Published inissue 1 December 1952…
The self-diffusion constant of the macromolecules in plasticized polystyrene and pure poly-n-butyl acrylate has been measured over a wide variety of conditions by a radioactive tracer technique. Well-characterized polymer fractions were used throughout. Simultaneous measurements of the bulk viscosity were also made. F…
Except for minor editorial revisions this paper is the reproduction of a report written for the Metallurgical Laboratory of the University of Chicago almost ten years ago, after the experimental production of a divergent chain reaction. This report has now been declassified and can be published. The present first part…
ABSTRACT The byssus threads, periostracum, hinge, ground substance of the shell, and the supporting material of the gills of Mytilus edulis, have been examined by physical, chemical, and histochemical means. The byssus threads, periostracum, and hinge have been shown to consist of a quinone-tanned protein. The byssus…
An attempt has been made to explain the observed viscous behavior of bulk polymers. It is found that the viscosity and diffusion may be represented by a theory which takes into account the coupling together of the molecules. Two equivalent treatments are given. One makes use of a segmental friction factor in the same…
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