Westinghouse Electric

About: Westinghouse Electric is a company organization based out in Cranberry Township, Pennsylvania, United States. It is known for research contribution in the topics: Brake & Signal. The organization has 27959 authors who have published 38036 publications receiving 523387 citations.

Advanced state VAr generator employing GTO thyristors

Abstract: The availability of large GTO thyristors has made advanced state VAr generators (ASVGs) competitive with their conventional counterparts. An ASVG substitutes silicon for large passive components. A description is given of a +or-1 MVAr prototype ASVG that was developed to prove the basic principles and verify performance under practical operating conditions. The prototype has been operating at the host utility site, Orange and Rockland Utilities Inc., Spring Valley, NY, since October 1986. An overview of the electrical and mechanical configuration and the test results are given. >

Mobilities of Atomic and Molecular Ions in the Noble Gases

Abstract: A method is described for measuring the mobilities of ions of near-thermal energy. A pulse of ions is generated in a discharge region and passes through a grid into a drift region where a uniform electric field causes the ions to move to a collector electrode. The mobilities are determined from measurements of the transit time of the ions in crossing the drift space. The experimental mobility values for thermal energy ions moving in their parent gases at 300\ifmmode^\circ\else\textdegree\fi{}K and a gas density of 2.69\ifmmode\times\else\texttimes\fi{}${10}^{19}$ atoms/cc are ${\ensuremath{\mu}}_{0}=10.5$ ${\mathrm{cm}}^{2}$/volt-sec (${\mathrm{He}}^{+}$), 20.3 (${\mathrm{He}}_{2}^{+}$), 4.0 (${\mathrm{Ne}}^{+}$), 6.5 (${\mathrm{Ne}}_{2}^{+}$), 1.60 (${\mathrm{A}}^{+}$), 2.65 (${\mathrm{A}}_{2}^{+}$), 0.90 (${\mathrm{Kr}}^{+}$), 1.21 (${\mathrm{Kr}}_{2}^{+}$), 0.58 (${\mathrm{Xe}}^{+}$), and 0.79 (${\mathrm{Xe}}_{2}^{+}$). These values are in good agreement with available theoretical results. Our measurements join smoothly at higher ion energies with the measurements made by Hornbeck and by Varney except in the case of ${\mathrm{A}}_{2}^{+}$. In addition, our results indicate that earlier measurements at near-thermal energy by Tyndall and collaborators refer to the molecular ions in helium and neon, and to the atomic ions in krypton and xenon.

Oxidation of Molybdenum 550° to 1700°C

Abstract: Weight change and oxygen consumption measurements were used to study the oxidation of molybdenum from 550° to 1704°C for pressures of 5 to 76 Torr. For temperatures of 550°–700°C two processes occurred simultaneously, oxide scale formation and molybdenum trioxide volatility. Above 800°C at pressures up to 76 Torr molybdenum trioxide volatilized as fast as it formed. At 900°C and 76 Torr using 1.2 cm2 samples the primary chemical reaction gave a rate of about 1018 at. molybdenum/cm2/sec. Above this temperature for 1.2 cm2 specimens the reaction was limited by gaseous diffusion of oxygen. Little change was found in the rate of oxidation to 1615°C. Pressure had only a small effect on the rate of reaction for these reaction conditions. However, in the chemically controlled region pressure had an important effect on the rate of oxidation. To extend the temperature region where the primary chemical reaction was rate controlling, samples of small area were used. A sample having a total area of 0.12 cm2 gave a reaction rate of . For these very fast reactions, appreciable temperature rises occurred, and the actual sample temperature had to be estimated. A log K vs. 1/T plot of the primary chemical reaction data gave an energy of activation of 19.7 kcal/mole. Reaction conditions where gaseous diffusion processes are rate controlling were determined. All of the earlier studies were made for these reaction conditions. The activated state theory of surface reactions was applied to the primary chemical reaction in the oxidation of molybdenum. A mechanism of mobile adsorption was found to be the primary chemical reaction. This adsorption process probably occurred on a surface already covered with a layer of adsorbed oxygen atoms since was volatilized.

Anharmonic Contributions to the Debye-Waller Factor

Abstract: Cubic- and quartic-anharmonic contributions to the Debye-Waller factor of a Bravais lattice have been obtained in the classical limit. The contributions are of two types: One is proportional to the square of the absolute temperature, and the other is proportional to the cube of the temperature. This is in contrast to the linear dependence on the absolute temperature of the Debye-Waller factor in the harmonic approximation. The first type of anharmonic contributions represents just the anharmonic corrections to the mean square amplitude of vibration of an atom, while the second type of term is related to the thermal average of the fourth power of an atomic displacement. These results have the consequence that with the anharmonic contributions included, the Debye-Waller factor for a cubic crystal is no longer isotropic in the components of the scattering vector, although it possesses cubic symmetry. The anharmonic contributions are evaluated numerically for a fcc crystal with nearest-neighbor, central-force interactions. The anharmonic contributions to the intensity of x rays scattered by one-phonon processes are discussed briefly.

The g-factor and de haas-van alphen effect of electrons in bismuth

Abstract: A theory of the g-factor of conduction electrons is developed which is valid for low symmetry and arbitrary strength of spin-orbit coupling. Application to bismuth shows that m≡ 2/g≃m 0 for most orientations, where m 0 is the effective mass entering the cyclotron frequency. Thus g is 260 when H is in the direction of smallest m 0. Further, the lifting of the spin degeneracy by the magnetic field introduces a factor cos τπm 0/m 8 into the rth oscillatory term in the susceptibility. This explains the apparent phase shift of τπ observed in the de Haas-van Alphen oscillations of Bi.