Materials Literature
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Pb(Zr-Ti)O 3 ceramics modified with WO 3 show low mechanical quality factor and low coercive field, but ones modified with combination of WO 3 and MnO 2 show high mechanical quality factor, high coercive field and stable aging characteristics. Temperature dependence of the resonant frequency is investigated in the wid…
A description is given of the design and operation of a drafting force tester, with emphasis on the material and process variables which influence test results. Visual observations are reported of sliver contraction, fiber straightening, and fiber snap back. Comparison is made between the force-deformation behavior of…
Abstract Lattice spacings perpendicular to the molecular chain axes and crystallite orientation of dried and moist (boiled in water) bulk nylon 6 were determined by x‐ray diffraction under tension of 30–300 kg./cm. 2 . The deformation of the specimen was also measured. The lattice spacings are changed reversibly by th…
Hall coefficient RH and Hall mobility μ have been measured for annealed polycrystalline and epitaxially grown gold, silver, and copper films at 296° and 77°K. At thicknesses above about 600 Å, nearly bulk values are obtained for RH and μ. Below 600 Å, a film-thickness dependence (size effect) was observed. This depend…
Models of the relaxed plain-knit structure proposed by previous workers suffer from the disadvantage of being based on the assumption of some geometrical shape for the knitted loop and are not derived from equilibrium considerations of the forces and couples applied to one loop by its neighbours. In the work described…
Tropocollagen preparations from carp, buffalo fish, rats, calves, sheep, and humans have been studied by electron microscopy and serologic methods. Tropocollagens from each species appeared identical by electron microscopy but they were readily distinguished (except between sheep and calves) by C'-fixation tests with…
Abstract In an attempt to understand the factors involved in morphogenesis of a complex cell like a scale or bristle, the fine structure of the normal development of bristle cells in Drosophila melanogaster (Oregon R) has been studied and compared with that of the mutants sn 3 and Sb. In the development of the normal…
The diffusion-controlled interphase-boundary migration problem is defined by a system of equations in which the boundary conditions for the diffusion equation are determined by capillarity. Numerical computer solutions to these equations were obtained for steady-state Widmanstätten ferrite plate growth. The effect of…
The solidification of a binary system differs from a pure metal in that the latent heat effect no longer occurs at the melting point but rather in a freezing zone between the liquidus and solidus temperatures. Such solidification is analyzed from a heat-transfer point of view. The system considered occupies a semi-inf…
The absorption edge spectrum of thin films of SnO2 has been obtained at room temperature using unpolarized light. The dependence of the absorption coefficient upon film resistivity has been noted and an impurity peak at about 3.4 eV has been observed. The measurements suggest an indirect edge near 2.7 eV and a direct…
Abstract The effect of preheat treatment at temperatures below the glass transition for various periods of time on selected properties of molded polycarbonate has been studied. Changes in tensile and flexural strength as functions of time and preheat temperature (80–140°C.) were determined and these are discussed in r…
Each moving unit of a long, flexible, molecule induces in the surrounding solvent a velocity field which reacts on the motion of other segments. This long-range hydrodynamic interaction modifies strongly the dynamical form factor $S(\mathbf{q}\phantom{\rule{0.25em}{0ex}}\mathrm{\ensuremath{\omega}})$ at low frequencie…
1. The membrane conductance of the crayfish muscle fibre was calculated and the increase in the membrane conductance brought about by the application of gamma-aminobutyric acid (GABA) was investigated under various conditions. The permeability of the activated inhibitory post-synaptic membrane was estimated from the c…
Flashover tests were conducted at the Leadville EHV Test Facility of the Public Service Company of Colorado and Project EHV at Pittsfield, Mass., to obtain comparative data to evaluate the influence of air density on switching surge and impulse flashover strength of transmission line insulation. The tests showed that…
Electrical resistivity and powder neutron diffraction patterns for Cr-V-Mn ternary dilute alloys have been measured at various temperatures. From the measurement an estimation is made on the Néel temperature, spin arrangement, average magnetic moment and wave vector of spin density wave. The ternary data are compared…
The two-dimensional analysis of the dry-relaxed knitted loop given in Part I of this series is extended to three dimensions by considering the couples acting on the loop at the points of interlocking. The fabric dimensional parameters and the knitted-fabric cover are evaluated for the three-dimensional structure, and…
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of some new perovskites containing indium and thalliumRobert D. ShannonCite this: Inorg. Chem. 1967, 6, 8, 1474–1478Publication Date (Print):August 1, 1967Publication History Published online1 May 2002Published inissue 1 August 1967https://pubs.acs.org/doi/10.1021/…
A series of tests, carried out by applying impulse waves simulating switching surges to air gaps with electrodes of different shapes, is described. From the test results, it has been possible to draw some important conclusions about the influence of the electrode shape and also to single out simple rules for the prede…
The velocity of dislocations of mixed edge-screw type in copper crystals of 99.999% purity has been measured as a function of stress at room temperature. Dislocation displacements produced by torsion stress pulses of microsecond duration were detected by etch pitting {100} surfaces. A nearly linear relationship betwee…
The melting, crystallization, and Form II to Form I transformation of isotactic polybutene-1 were studied under hydrostatic pressures up to 5000 atm. The melting behavior of Form I was similar to that of other polymers, showing an increase in melting temperature and decrease in the volume of melting with pressure. Cry…