Materials Literature
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The structural features of the porous type of anodic oxide coating applied to aluminum have been investigated with the electron microscope. These coatings consist of close‐packed cells of oxide, predominately hexagonal in shape, each of which contains a single pore. Pore size is a function of the electrolyte used and…
H. U. Sverdrup; On Conditions for the Vernal Blooming of Phytoplankton, ICES Journal of Marine Science, Volume 18, Issue 3, 1 January 1953, Pages 287–295, https
Abstract The method described in part I for the determination of the thermionic constants of graphite, which is based on finding the saturation vapour pressure of the electron gas in a graphite chamber at different known temperatures, and applying the well-known thermodynamic relation of Clausius and Clapeyron, can be…
Abstract The theory of a Ce3+ ion in a crystal is considered as that of a free ion with a single 4f electron outside closed shells, and the effect of the surrounding lattice is included as a static crystalline electric field. The problem is solved when this field has C3k symmetry. It is possible that this theory will…
Abstract The anomalous skin effect arises in good conductors at low temperatures and high frequencies when the electronic mean free path becomes comparable with or greater than the classically calculated skin depth. Measurements have been made on a number of metals at frequencies of 1200 and 3600 Mc/s, and the form of…
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…