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 & Circuit breaker. The organization has 27959 authors who have published 38036 publications receiving 523387 citations.

Stabilization of tetragonal phase in polycrystalline zirconia

Abstract: It is shown that the tetragonal phase can be stabilized in the sintered body of a partially stabilized zirconia (PSZ) containing low concentrations of yttria. Such sintered body containing the metastable phase undergoes stress-induced phase transformation by the absorption of thermal or mechanical stress and exhibits strengths in excess of 690 MPa (100ksi).

Rotational Excitation and Momentum Transfer Cross Sections for Electrons in H 2 and N 2 from Transport Coefficients

Abstract: Rotational excitation and momentum transfer cross sections for low-energy electrons in hydrogen and nitrogen are obtained from a comparison of theoretical and experimental values for the mobility and the diffusion coefficient. The theoretical values of the transport coefficients were obtained by calculating accurate electron energy distribution functions using an assumed set of elastic and inelastic cross sections. The discrete nature of the energy loss occurring in a rotational or vibrational excitation collision was included in the theory, as were collisions of the second kind with thermally excited molecules. The resulting values of drift velocity and characteristic energy $\frac{D}{\ensuremath{\mu}}$ were compared with experimental data and adjustments made in the assumed cross sections until good agreement was obtained. The momentum transfer cross sections found in this manner agree well with several recent analyses valid in restricted energy ranges. The final values of the rotational excitation cross sections are about twice the values computed using the theory of Gerjuoy and Stein and the latest available value for the molecular electric quadrupole moments. In hydrogen, the analysis has been extended to energies for which vibrational excitation is important. A vibrational cross section with a maximum of roughly 5\ifmmode\times\else\texttimes\fi{}${10}^{\ensuremath{-}17}$ ${\mathrm{cm}}^{2}$ at 3 eV is consistent with the measurements.

Electrical and Thermal Properties of Bi 2 Te 3

Abstract: Samples of both $n$-type and $p$-type ${\mathrm{Bi}}_{2}$${\mathrm{Te}}_{3}$ containing from 3\ifmmode\times\else\texttimes\fi{}${10}^{17}$ to 5\ifmmode\times\else\texttimes\fi{}${10}^{19}$ extrinsic carriers were prepared and the phase diagram in the region about ${\mathrm{Bi}}_{2}$${\mathrm{Te}}_{3}$ has been clarified. The Hall mobility parallel to the cleavage planes varies as ${T}^{\ensuremath{-}1.5}$ for holes and ${T}^{\ensuremath{-}2.7}$ for electrons. Room temperature values are ${\ensuremath{\mu}}_{p}=420$ ${\mathrm{cm}}^{2}$ ${\mathrm{v}}^{\ensuremath{-}1}$ ${\mathrm{sec}}^{\ensuremath{-}1}$ and ${\ensuremath{\mu}}_{n}=270$ ${\mathrm{cm}}^{2}$ ${\mathrm{v}}^{\ensuremath{-}1}$ ${\mathrm{sec}}^{\ensuremath{-}1}$. The energy gap is ${E}_{g}=0.20$ electron volts. From thermal conductivity measurements over the temperature range from 77\ifmmode^\circ\else\textdegree\fi{}K to 380\ifmmode^\circ\else\textdegree\fi{}K the lattice conductivity was found to be ${\ensuremath{\kappa}}_{L}=5.10\ifmmode\times\else\texttimes\fi{}\frac{{10}^{\ensuremath{-}2}}{T}$ watt-${\mathrm{deg}}^{\ensuremath{-}1}$ ${\mathrm{cm}}^{\ensuremath{-}1}$. The sharp rise in the thermal conductivity in the vicinity of room temperature was attributed to transport of energy by ambipolar diffusion of electrons and holes.

Development of a /spl plusmn/100 MVAr static condenser for voltage control of transmission systems

Abstract: The availability of high power gate-turn-off (GTO) thyristors has led to the development of controllable reactive power sources, using electronic switching power converters, for use in power transmission systems This new technology has resulted in equipment that is fundamentally different from the conventional thyristor-controlled static VAr compensator (SVC) The new equipment is called a static condenser (STATCON) because its steady state output characteristics are similar to those of the rotating synchronous condenser The paper describes the fundamental operating principles, functional characteristics and basic control approach of the STATCON, with particular reference to a /spl plusmn/100 MVAr prototype planned to be installed at the Tennessee Valley Authority (TVA) Sullivan substation, USA This installation will be the first demonstration of a STATCON under the EPRI flexible AC transmission systems (FACTS) program, and will be the largest installation of its type in the world >

Theoretical and Experimental Aspects of the Effects of Point Defects and Disorder on the Vibrations of Crystals—1

Abstract: Publisher Summary One of the more interesting results of the theoretical studies of time-dependent lattice dynamical defect problems has been their prediction of resonance mode. These are exceptional modes whose frequencies lie in the ranges allowed to the normal modes of the perfect host crystal, and which can be characterized qualitatively either by the resonance-type peaks they contribute to the frequency spectrum of the perturbed crystal or, alternatively, by a large amplitude of vibration for the impurity atom or those atoms with which it directly interacts. A precise definition of resonance modes is given in this chapter. They can have interesting consequences for several physical properties of crystals, and their experimental observation is described here. This chapter indicates a wide range of experimental methods that already exists for the study of the dynamical properties of crystals containing point defects, and the complementary and supplementary nature of the results obtained by different methods. The accompanying theoretical discussion varies widely in the detail in which different topics are treated.