Materials Literature
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Abstract By the incorporation of certain types of additives in bisphenol A polycarbonate, the modulus and tensile strength of the films are increased and the elongation is decreased. This effect is called antiplasticization, because the opposite results are obtained on plasticization—decreased modulus and tensile stre…
The latent hardening produced by straining copper crystals in single glide was investigated by measuring the flow stress on secondary systems. Specimens oriented for slip on these systems were spark cut from large prestrained crystals and tested in tension. These specimens did not always yield on the most highly stres…
A computer program that determines the stress required to move a dislocation through an array of obstacles distributed at random on a slip plane has been written. This program has been used to measure the critical shear stress of random arrays of (a) obstacles of various equal strengths, (b) obstacles with two differi…
A thorough review is made of the application of the Peierls model to the macroscopic plastic deformation of ionic crystals, metals, alloys, and covalently bonded crystals. The effects of the shape of the Peierls hill, kink–kink energies, and the frequency terms on the stress–temperature and activation volume–stress re…
Phenomenological equations between dislocation velocity, effective shear stress, temperature, and pressure are presented. It is suggested that the term "activation volume" be properly assigned to the pressure dependence of dislocation velocity. Indirect methods of determining velocity–stress relations are reviewed, an…
The form of vacancy clusters in quenched aluminium of 99.99% purity has been investigated using transmission electron microscopy techniques. A new four-layer planar vacancy cluster lying on parallel {111} planes has been observed and its structure has been characterized by observing both the unfaulting behaviour of th…
<div class="htmlview paragraph">Theoretical and experimental investigations were carried out for the purpose of predicting and measuring the performance which results from operation of compression ignition engines when anhydrous ammonia is used rather than diesel fuel. Predictions were that ammonia would give sl…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTA simplified synthesis for meso-tetraphenylporphineAlan D. Adler, Frederick R. Longo, John D. Finarelli, Joel Goldmacher, Jacques Assour, and Leonard KorsakoffCite this: J. Org. Chem. 1967, 32, 2, 476Publication Date (Print):February 1, 1967Publication History Published onli…
From configurational entropy considerations, it is estimated that the grains in silica glass are far more likely to have a cristobalite structure than a pentagonal dodecahedral one.
Abstract The recombination of nitrogen atoms has been studied photometrically in a fast flow system. The concentration of nitrogen atoms was determined by nitric oxide titration. The measured bimolecular rate constant has the form kB = A + B[M] for M = N2, Ar and He with a constant value of A. The surface process was…
The phase diagram of sulfur has been investigated up to 60 kbar by differential thermal conductivity analysis in piston-cylinder and tetrahedral devices. The data indicate that the melting curve of orthorhombic sulfur rises to a triple point between orthorhombic, fibrous, and liquid sulfur at 37 kbar and 410\ifmmode^\…
The bulk electrical conductivities of a series of monocarboxylic and polycarboxylic aromatic acids and some derivatives of these acids have been measured in order to study the effect of hydrogen bonding on conductivity. Electrical measurements were made on carefully purified, polycrystalline samples, compressed to rem…
The absorption edge (380-500 m\ensuremath{\mu}) of AgBr was investigated with fine-grain suspensions in water. When the small amount of Rayleigh scattering was subtracted, the absorption coefficient was calculated from the remaining specular density. Comparison of crystals of about 65 \AA{} radius with bulk material s…
The electron spin resonance of magnesium pyrophosphate (Mg2P2O7) doped with 0.3% manganese pyrophosphate has been studied at room temperature and in the temperature range of 55° to 94°C using a microwave frequency of 35 Gc/sec. The parameters of the spin Hamiltonian and the orientation of the principal axes of the Mn2…
The mechanism of energy transfer between Eu and Nd and the migration of excitation between Eu ions in the Na0.5(Y, Eu, Nd)0.5Wo4 tungstates and (Y, Eu, Nd)2O3 sesquioxides are examined. Transfer from Eu to Nd appears to be predominately by dipole—dipole interactions. At high Eu concentrations energy may migrate betwee…
A number of experimental techniques have been combined to study radiation-induced defects that are complementary to $F$ centers. One series of experiments, in which the resistance to dislocation motion due to interstitial centers was monitored by means of flow-stress changes, indicated that the centers produced by irr…
Critical scattering of neutrons around the superlattice reflections (1, 0, 0) and (1, 1, 1) from a single crystal of $\ensuremath{\beta}$-brass has been measured at temperatures from 2 to 25\ifmmode^\circ\else\textdegree\fi{}C above the transition temperature. The temperature dependence of the critical peak intensity,…
Phonons in sodium fluoride have been studied at room temperature using inelastic neutron scattering techniques. Consistent results were obtained using a cold neutron time-of-flight apparatus and a triple-axis spectrometer. The time-of-flight results were interpolated on to symmetry directions from the observed scatter…
The spectra between 4000 and 23 000 cm−1 of gaseous UCl4 have been obtained for the temperature range 950° to 1250°K. These spectra have been compared with those of single-crystal UCl4 at 77°K and room temperature. Spectra of solid UCl4 were obtained over the temperature range 300° to 827°K in order to compare with th…
The electrical resistivity and the magnetoresistance in $n$-type InSb containing more than 1.8\ifmmode\times\else\texttimes\fi{}${10}^{14}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ carriers have been measured from 4.2 to 0.1\ifmmode^\circ\else\textdegree\fi{}K. The resistivity increases logarithmically as the temperature is…