Materials Literature
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Small crystals of natural graphite showing no evidence of twinning were found in a sample of marble from the Lead Hill mine (Ticonderoga, New York). They were isolated, handled very carefully to avoid deformation, and their $c$-axis conductivity determined. It was found to be about 2\ifmmode\times\else\texttimes\fi{}$…
The thermal expansions of a number of binary lithium, sodium, and potassium silicate glasses are reported over the tempcrature range from room temperature to thcir deformation points. The expans ivities of the glasses increased with increasing alkali oxide concentration. These expansivities were used to calculate dens…
The acceleration of high temperature corrosive attack on heat-resistance alloys caused by the presence of vanadium compounds is well established. The progressive addition of sodium sulfate to the vanadium contaminant indicates that the most corrosive mixture is approximately 20 percent sodium sulfate—80 percent vanadi…
A determination of the Cu63 nuclear resonance line width in concentrated hydrochloric acid solutions containing both cuprous and cupric chloride leads to an evaluation of the bimolecular rate constant k for the electron exchange process Cu+++Cu+→+Cu++Cu++.The experimentally determined value for k is k = 0.5×108 liter/…
Neutron diffraction measurements have been made on iron at a series of elevated temperatures up to about 1000\ifmmode^\circ\else\textdegree\fi{}C to establish the magnetic scattering effects through the Curie temperature and in the $\ensuremath{\gamma}$-phase region. Diffraction patterns obtained for the face-centered…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTDegradation of Polyphosphates in Solution. I. Kinetics and Mechanism of the Hydrolysis at Branching Points in Polyphosphate Chains1Ulrich P. Strauss and Theodore L. TreitlerCite this: J. Am. Chem. Soc. 1956, 78, 15, 3553–3557Publication Date (Print):August 1, 1956Publication…
An apparatus is described to measure volumetrically the amount of gas adsorbed by a catalyst at constant pressure and at exposure times as short as 0.1 min. The volumes of oxygen adsorbed by a technical silver catalyst at pressures of 200, 400, and 700 mm. and in the temperature range of 180° to 300°C. have been measu…
During neutron irradiation at 100°c alpha uranium creeps slowly (e.g. 10−−7 per hour) under external stresses of order of one-hundredth of the normal yield stress of the metal at that temperature. This effect is predicted as a consequence of the phenomenon of “radiation-growth” which occurs in uranium, and is then con…
The magnetization of some rare-earth orthoferrites and related compounds, and of some iron-group cyanides, has been investigated at temperatures between room temperature and 1.3\ifmmode^\circ\else\textdegree\fi{}K. Some are ferromagnetic, some antiferromagnetic, and some paramagnetic following the Curie-Weiss law.The…
Journal Article Clays and Clay Minerals Get access Clays and Clay Minerals, Edited byAdaSwinepord, Norman Plummer, Proceedings of the Second National Conference on Clays and Clay Minerals. National Academy of Sciences-National Research Council, Washington, D. C, 1954. viii pp. Illus., index, bibl. R A Heindl R A Heind…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Plutonium-Hydrogen System. II. Solid Solution of Hydrogen in Plutonium Dihydride1Robert N. R. Mulford and Gladys E. SturdyCite this: J. Am. Chem. Soc. 1956, 78, 16, 3897–3901Publication Date (Print):August 1, 1956Publication History Published online1 May 2002Published in…
The' linear t he rm a l ex pa nsion of fOlll samples of T eflo n was de termined . The' res ults for an neil. lecl T eflon m'e indi cated in a plot of t he ex pa nsion vel s us te m perature and in iI. table li st in g t he average coeffi cLCnts of lincar expa ns io n from -J 90 to + 300 C. The eff ect of internal r e…
Abstract The tear properties of natural rubber and GR‐S vulcanizates containing carbon black are compared with those of gum vulcanizates, using a method developed in a previous paper. The distinctive features in the tear behavior of the filed vulcanizates are noted and discussed. The results indicate that there are tw…
A phenomenological theory of the time dependence of mechanical breakdown phenomena is presented which is applicable to creep failure of oriented polymeric filaments under tensile stresses. In using the theory, one makes assumptions about the distribution of breaking times in ensembles of filaments which are bearing co…
Abstract Increasing the degree of crystallization of unoriented 66 or 610 nylon increases the stiffness, yield point, tensile strength, and hardness, but reduces the impact strength, particularly in the high crystallinity range. The impact strength was increased by increasing the molecular weight, but the other proper…
Abstract The bands due to stretching of OH groups of all four crystalline modifications of cellulose have been measured using a deuteration technique which enables crystalline regions to be studied independently of amorphous regions. Cellulose III prepared from cellulose I (III I ) was found to be different from cellu…
The reduction in the ionization loss of charged particles due to the polarization of the medium has been calculated using the mean excitation potentials recently determined by Caldwell. Values of the coefficients of an approximate analytic expression for the density effect correction have been obtained for a number of…
The propagation of short mechanical pulses along rods of three polymers, polythene, polystyrene and polymethylmethacrylate, has been investigated experimentally. The pulses were produced by the detonation of small quantities of explosive at one end of a rod and a condenser microphone was employed to record the displac…
The switching time ts and the switching current imax have been measured as a function of applied field E and of the size of the sample. It has been observed that the ``activation field'' α for the nucleation of new domains is inversely proportional to the thickness of the sample. This behavior can be explained by assu…
Descemet's membrane, previously thought to be "structureless," has been found to be characterized by a fine structure of great regularity. Sections perpendicular to the plane of the membrane surface appeared to be cross-striated, with narrow dark bands separated by wide light bands traversed by fine filaments. Tangent…