Materials Literature
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Abstract The Hall coefficient and resistivity of a range of polycrystalline graphites with different crystal sizes and a single crystal of Travancore graphite have been measured over a wide range of temperature. The number of free electrons has been found to be approximately 6x1018 per cm3 at room temperature; the var…
Abstract In liquids the molecular configuration is a function of temperature. If in a given substance super-cooling of the liquid is possible to such a low temperature—the ‘transformation temperature’ (Tg)—that the viscosity reaches about 1013 poises, the required changes in configuration become impossible and at all…
INTRODUCTION The following described materials have been unearthed partly during the construction of the Ch ngtu-Chungking Railway mainly in 1951 and partly during the clearing away the building foundation in Tatienwan, a suburb of Chungking.
Mole\`ere's theory of multiple scattering of electrons and other charged particles is here derived in a mathematically simpler way. The differential scattering law enters the theory only through a single parameter, the screening angle ${{\ensuremath{\chi}}_{a}}^{\ensuremath{'}}$, Eq. (21). The angular distribution, ex…
Abstract Several configurations of polypeptide chains involving planar amide groups with the dimensions found by experiment for simple substances, and hydrogen bonds between the NH groups and the carbonyl oxygen atoms, have been discovered. One of these structures, the α-helix, with about 3·7 amino-acid residues per t…
Since the first studies with bacterial corrosion of underground pipe lines in 1939 in the United States chief interest has been centered in this subject in the Eastern states. Indications are that the causative sulfate-reducing bacteria and the characteristic anaerobic soils associated with their corrosive action are…
Paul R. Kent, MSC, USN, J. Howard Steeve, MSC, USN; Convergence Insufficiency: Incidence Among Military Personnel and Relief by Orthoptic Methods, The Mili
The mineral gyrolite was discovered in Skye by T. Anderson in 1851. He showeditto be ahydratedcaleiumsilicateofapproximate composition 2CaO.3SiO 2 .3H 2 O. Subsequently gyrolite has been found in other localities, and has been prepared hydrothermally by Flint, McMurdie, and Wells. The ratio of lime to silica found by…
Abstract Die Darstellung von Mangan(VII)‐oxyd aus Kaliumpermanganat und konz. Schwefelsäure wird beschrieben, Mangan(VII)‐oxyd ist eine in der Aufsicht grüne, in der Durchsicht rote, ölige Flüssigkeit vom Smp. 5,9° und dem Zersetzungspunkt ∼55°. D = 2,396; elektr. Leitfähigkeit x < 4 · 10 −9 Ohm −1 · cm −1 . Dielek…
When an alloy develops an ordered structure, new Brillouin zone boundaries are formed corresponding to the extra Bragg reflections. It is shown that, in this process, the Fermi energy is lowered, and this tends to stabilize the superlattice. The theory is applied to the superlattices in CuPt, CuAu and Ag 3 Mg, where t…
A study of the thermal decomposition of nitromethane was made by the flow method, with nitrogen as carrier gas, the reaction being followed by polarographic analysis of the effluent from the furnace for nitromethane. When carefully dried nitrogen was used the rate of disappearance of nitromethane became erratic; it wa…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Catalytic Oxidation of Carbon Monoxide on Nickel Oxide. I. Pure Nickel OxideG. ParravanoCite this: J. Am. Chem. Soc. 1953, 75, 6, 1448–1451Publication Date (Print):March 1, 1953Publication History Published online1 May 2002Published inissue 1 March 1953https://pubs.acs.o…
The error in the Worthington (1885) sessile drop equation, as an approximation to the exact equation from which it was derived, is found to be of the order of experimental errors in recent surface tension determinations. The source of error and origin of the optical band system observed when parallel light is used to…
Synopsis In 1913, a grain elevator near Winnipeg, Canada, experienced a bearing-capacity failure during its first loading. The foundation consisted of a large rectangular raft resting on a plastic clay deposit. The load at failure is known. This article presents the results of tests made to determine the properties of…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCatalytic Activity of Lanthanum and Strontium ManganiteG. ParravanoCite this: J. Am. Chem. Soc. 1953, 75, 6, 1497–1498Publication Date (Print):March 1, 1953Publication History Published online1 May 2002Published inissue 1 March 1953https://pubs.acs.org/doi/10.1021/ja01102a52…
In a previous paper (Brindley, 1951) chamosites from a number of localities were examined, and their structure was shown to be of kaolin-type. Furthermore, it was shown that many of the variations in X-ray powder diagrams of chamosites can be accounted for by the existence of two kaolin-type structures, one hexagonal…
Young's moduli (E) of the directions 〈100〉 and 〈111〉 and the shear modulus (G) for 〈100〉 were determined in germanium from −195 to 255, 275, and 140°C, respectively. From these moduli, the elastic parameters, the compressibility, and Poissons's ratio were calculated. The thermal expansion was measured from −196 to 275…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTHE CHEMISTRY OF HYDROPEROXIDES. XII. THE GENERATION AND PROPERTIES OF FREE RO2. RADICALSM. S. KHARASCH, PETER PAUSON, and WALTER NUDENBERGCite this: J. Org. Chem. 1953, 18, 3, 322–327Publication Date (Print):March 1, 1953Publication History Published online1 May 2002Publish…
Abstract A method for following rapid crystallization in polymers using infrared absorption has been devised. The infrared absorption was correlated quantitatively with the density of polyethylene terephthalate for varying degrees of crystallinity and qualitatively with the change in x‐ray diffraction pattern on cryst…
C . W. Bunn and H. Emmett have observed the spreading, of multi-molecular layers on growing crystals of artificial compounds, and have suggested that deposition takes place on the high-index surfaces at the edges of the layers. Their work led the author to examine crystals of several mineral species for evidence of th…