Materials Literature
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The growth of germanium dendrites containing two twin planes has been investigated. The solution of the heat flow problem in the stem of a growing dendrite being pulled from a melt permitted the design of experiments suitable for testing theory. The limiting growth velocity was determined as a function of melt underco…
A technique is described for testing rutile single crystals in compression at elevated temperatures. The stress‐strain behavior of crystals of four different orientations was examined up to temperatures in excess of 1000°C, and a dependence of both the flow stress and the rate of work hardening on crystal orientation…
Nuclei of several isotopes of promethium were aligned at low temperatures by a pseudoquadrupole interaction in cerium magnesium nitrate and by a magnetic hfs interaction in neodymium ethylsulfate. Pseudoquadrupole coupling constants were determined for ${\mathrm{Pm}}^{143}$, ${\mathrm{Pm}}^{144}$, and 5.4-day ${\mathr…
Abstract The structure of hexagonal polyoxymethylene has been re‐examined by means of x‐rays. The parameters of the elementary cell, the space groups, and the model of the spiral chain previously described in the literature for this polymer have been discussed. A new elementary cell and a new type of helical chain wit…
Abstract The steady‐state (d.c.) electrical conductivity of polypropylene has been measured as a function of temperature (25–150°C.) and field strength (0–94 kv./cm.). The temperature coefficient of the conductivity is 34.6 kcal./mole expressed as an activation energy. This is much larger than the activation energy fo…
Ac electrical conductivity measurements have been made on polycrystalline samples of various compositions in the MgO–NiO system. Four activation energies have been obtained with pure MgO: 5.2, 2.7, 3.5, and 0.92 eV. These seem to be the activation energies, respectively, for intrinsic O= conductivity, extrinsic O= con…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarbon-13 Nuclear Magnetic Resonance Spectra of Olefins and Other HydrocarbonsR. A. Friedel and H. L. RetcofskyCite this: J. Am. Chem. Soc. 1963, 85, 9, 1300–1306Publication Date (Print):May 1, 1963Publication History Published online1 May 2002Published inissue 1 May 1963htt…
Randomly oriented fibers of either molybdenum or niobium were incorporated into hot‐pressed pellets of 10, 30, and 50 wt% UO 2 in ThO 2 to improve the thermal conductivity and the thermalshock resistance. Pellets 3/8 in. in diameter and about 3/8 in. long were irradiated in NaK capsules either bare or jacketed in Zirc…
SUMMARY Vitamin B12 is an essential nutrient for the flagellate Prymnesium parvum when growing in axenic culture and apparently can be replaced only by a few related ‘incomplete’ analogues, i.e. only those devoid of one or both benzimidazole-methyl groups; and, of the substituted analogues, some (e.g. the mono-acid, t…
Abstract The dynamic properties of a natural vulcanized rubber containing carbon black were studied for dynamic tensions of amplitude varying greatly. It was shown that both the elastic responses and viscosity change with amplitude of oscillation and with concentration and type of carbon black. The effects of thermal…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Structure of Copper TetraphenylporphineEverly B. FleischerCite this: J. Am. Chem. Soc. 1963, 85, 9, 1353–1354Publication Date (Print):May 1, 1963Publication History Published online1 May 2002Published inissue 1 May 1963https://pubs.acs.org/doi/10.1021/ja00892a032https://…
Lattice parameters and distribution coefficients for the Bi2Te3-Bi2Se3 pseudobinary alloy system have been determined for several compositions across the phase diagram. The c lattice constant (based on a hexagonal lattice) shows deviation from Vegard's law between 33% Bi2Se3 and pure Bi2Se3 with maximum deviation at 6…
Perovskites of the system SrFeO 3 ‐SrTiO 3 were prepared, and measurements were made of their magnetic and electrical behavior. Chemical analysis showed that the percentage of Fe 4+ varied from 72.5% for SrFeO 2.86 to about zero for Sr(Fe 0.1 Ti 0.9 )O 2.95 ; the remainder of the iron was in the Fe 3+ state and electr…
Abstract Soil factors which have been reported to affect lime requirement were measured on 26 Wisconsin Soils, and the importance of these factors in predicting lime requirement was determined by use of linear and multiple regression. The lime requirement was taken as the amount of < 200‐mesh dolomitic limestone ne…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTPreparation and Structures of Metal Cyanide-Lewis Acid Bridge CompoundsD. F. ShriverCite this: J. Am. Chem. Soc. 1963, 85, 10, 1405–1408Publication Date (Print):May 1, 1963Publication History Published online1 May 2002Published inissue 1 May 1963https://pubs.acs.org/doi/10.1…
Abstract A polybenzimidazole has been prepared from 3,3′‐diaminobenzidine and phthalic anhydride which has a high molecular weight and very good heat stability. Replacement of the hydrogen atoms on the nitrogen of the imidazole nuclei in a polybenzimidazole does not improve the heat stability as indicated by the prope…
fl-Pu is monoclinic body-centered with 34 atoms per unit cell. At 190 C a=9.284, b=10.463, c=7.859/~, fl=92.13 and the density is 17.70 g.cm. -3.
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTFertilizer Materials, Preparation and Characterization of Some Calcium PyrophosphatesE. H. Brown, J. R. Lehr, J. P. Smith, and A. W. FrazierCite this: J. Agric. Food Chem. 1963, 11, 3, 214–222Publication Date (Print):May 1, 1963Publication History Published online1 May 2002P…
Abstract Wakelin's method of correlation analysis of x‐ray diffraction patterns was adapted for fibers, films, and polymer samples of poly(ethylene terephthalate). This method gives a number called a crystallinity index, which is a measure of how far an unknown sample is between the extremes of the most amorphous and…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Metal-Metal Bonded, Polynuclear Complex Anion in CsReCl4J. A. Bertrand, F. A. Cotton, and W. A. DollaseCite this: J. Am. Chem. Soc. 1963, 85, 9, 1349–1350Publication Date (Print):May 1, 1963Publication History Published online1 May 2002Published inissue 1 May 1963https:/…