Experimental dissolution of calcium, magnesium, and strontium from Recent biogenic carbonates; a model of diagenesis
Abstract Incongruent dissolution of aragonite and magnesium calcite
Materials Literature
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Magnetic semiconductors
Both semiconductors and magnetic materials exhibit interesting properties that can be used in electronic devices. A material that combines these properties, i.e., a magnetic semiconductor, could show interesting cross effects, such as a large magnetoresistance, or hysteresis and the associated memory phenomena introdu…
Hot‐Working of Aluminum Oxide: I, Primary Recrystallization and Texture
Polycrystalline aluminum oxide was hot‐worked at 1750° to 1950°C and at stresses <21, 000 psi using a press‐forging technique. No ductility problems were encountered, and maximum true strains and strain rates of ‐1.25 and 0.2/min, respectively, were observed. Deformed samples often showed grain elongation in additi…
Adsorption of Nitrate in Amorphous and Kaolinitic Hawaiian Soils
Abstract The adsorption of nitrate in an amorphous Akaka silty clay and kaolinitic Wahiawa silty clay increased consistently with increasing concentration and decreasing pH of the electrolyte solution. The magnitude of adsorption was higher in the Akaka than in the Wahiawa soil. The amount of adsorbed nitrate was nota…
Gitterschwingungsspektren. III. Mitteilung
Zur Klärung der Frage, inwieweit die Gitterschwingungen der Spinelle bestimmten Koordinationspolyedern oder der gesamten Elementarzelle zuzuordnen sind, wurden die Zahl, der Schwingungstyp und die Symmetriekoordinaten der Schwingungen aus der Faktorgruppe des idealisierten Spinellgitters (Raumgruppe F4 1 /d3̄̅2/m) abg…
CATION EXCHANGE PROPERTIES OF MICAS
Summary The abilities of 10 trioctahedral and 3 dioctahedral micas to release K by cation exchange were compared by repeatedly extracting the micas with NaCl solutions. For a chosen solution concentration and pH, the quasi‐equilibrium concentration of K in a solution in contact with a mica is largely independent of th…
Surface tension of polymer solutions. I. Solutions of poly(dimethylsiloxanes)
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSurface tension of polymer solutions. I. Solutions of poly(dimethylsiloxanes)George L. Gaines Jr.Cite this: J. Phys. Chem. 1969, 73, 9, 3143–3150Publication Date (Print):September 1, 1969Publication History Published online1 May 2002Published inissue 1 September 1969https://…
Physics of Instabilities in Amorphous Semiconductors
A four-fold classification of the current-controlled instabilities in amorphous semiconductors is proposed. The experimental evidence supporting a simple band model for the amorphous covalent alloys is given. The present understanding of the reversible switching effects and of the switching with memory is discussed.
Thermally induced solid state polycondensation of nylon 66, nylon 6‐10 and polyethylene terephthalate
Abstract The mechanism of solid state polycondensation has been subjected to a fundamental analysis. Equations were formulated for combined diffusion and chemical reaction for two separate situations. One was for solid state polycondensation in polymer flakes or chips. The other dealt with polymer powders. The resulta…
Ring-current effect of the phthalocyanine ring
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRing-current effect of the phthalocyanine ringThomas R. Janson, Alexander R. Kane, John Francis Sullivan, Kerro Knox, and Malcolm E. KenneyCite this: J. Am. Chem. Soc. 1969, 91, 19, 5210–5214Publication Date (Print):September 1, 1969Publication History Published online1 May…
Mechanical Properties of Metal Oxide Films
A brief review is given of mechanical property measurements on oxide films. This review is followed by a detailed discussion of the mechanical and fracture properties of anodic aluminum oxide films as observed in the author's laboratory. Extensive measurement of Young's modulus, <mml:math xmlns:mml="http://www.w3.org/…
Twenty million energy product samarium-cobalt magnet
Considerable interest has been centered around rare-earth-cobalt magnets during recent years. For the last two years we have been carrying out a research program in the general area of rare-earth-cobalt magnets. At this time, we have successfully developed a rare-earth-cobalt magnet with close to the attainable limit…
Infra-red absorption due to localized modes of vibration of impurity complexes in ionic and semiconductor crystals
A brief account is given of the theory of the vibrations of an imperfect crystal containing isolated impurities and pairs of impurities, and the strength of the induced infra-red absorption is discussed. An analysis is then made, by the methods of group theory, of the energy levels and expected optical transitions of…
Scattering of light from assemblies of oriented rods
Abstract The scattering patterns are calculated from anisotropic rods having an arbitrary angle of the polarizability axis with respect to the rod axis. The effect of a distribution of orientation of the rods is explored. This leads to a change in scattering patterns produced by orienting the rods upon stretching the…
High magnetic permeability in Ni-Fe-Cu-Mo alloys
Earlier work showed that some low-field magnetic properties of high-permeability Ni-Fe alloys containing about 80-percent Ni could be explained by considering the effect of the filling of the 3d vacancies of the Ni atoms by the outermost electrons of an added nonferromagnetic element. This work is extended to show how…
Phosphorescence Mechanism in CdF2:Eu3+
Single crystals of CdF2, doped with Eu3+, were grown by the Bridgman method, and shown by fluorescence and absorption spectra to contain no detectable Eu2+, irrespective of the presence of Na+ or Y3+ as added impurities. Ultraviolet irradiation at 77°K produced a new broad absorption band near 3400 Å, which disappeare…
Photodegradative wavelength dependence of thermally resistant organic polymers
Abstract The wavelength dependence of photodegradation of three “high temperature” aromatic polyamide polymers has been very accurately determined by means of a fast grating spectrograph used in conjunction with a high pressure xenon arc. One of these polymers, the poly‐(isophthalamide) of 4,4′‐bis( p ‐aminophenyl)‐2,…
A histological study of the regenerative response in a lizard, Anolis carolinensis
Abstract Amputated hyperinnervated Anolis carolinensis limbs were studied histologically at various times from early stages of post‐amputational wound healing to formation of mature mounds. Comparable stages of normally innervated amputated limbs were also studied. The sequence of events involved in tissue repair was…
Measurement of Curative Diffusion Between Rubbers by Microinterferometry
Abstract Diffusion of sulfur and MBTS across interfaces between dissimilar rubbers has been measured by microinterferometry. This technique involves the comparison of optical path length through refractive index gradients, due to diffusion, against that of a reference area. Differential diffusion coefficients are obta…
Elastic Properties of Polycrystalline Yttrium Oxide, Holmium Oxide, and Erbium Oxide: High‐Temperature Measurements
The Young's and shear moduli of polycrystalline yttrium oxide, holmium oxide, and erbium oxide were determined from room temperature to 1000°C using the sonic resonance technique. The bulk modulus and Poisson's ratio were computed as functions of temperature for each oxide. The Young's, shear, and bulk moduli decrease…