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.

Thermodynamics of sodium chloride solutions at high temperatures

Abstract: Osmotic coefficients are reported from vapor-pressure-lowering measurements on sodium chloride solutions at concentrations from approximately 4m to saturation and at temperatures from 75° C to 300° C. In combination with previously reported measurements at lower concentrations, these results allow a correlation of free energies for the system NaCl−H2O over a range of concentrations and temperatures that is unprecedented for any aqueous electrolyte. Activity coefficients and other thermodynamic quantities for both salt and water have been calculated for the complete range of concentrations and temperatures. Calculated heats of solution and standard partial molal entropies agree well with calorimetric determinations where comparison is possible. The excess partial molal entropy of the salt is informative concerning structural effects and their changes with temperature and concentration.

Exciton Recombination Radiation and Phonon Spectrum of 6 H SiC

Abstract: A photoluminescence spectrum consisting of about 50 lines has been observed at low temperatures in $6H$ SiC. The spectrum can be attributed to exciton recombination after capture by un-ionized nitrogen atoms. The mechanism is similar to that first reported by Haynes for impurities in Si, but the large unit cell of $6H$ SiC (with 12 atoms) provides three inequivalent sites for nitrogen, and 36 phonon branches, hence the large number of lines. Seventeen phonon energies have been measured and plotted in a plausible way in an appropriate extended k space, leading to some conclusions about the band structure of $6H$ SiC. Spin-orbit splitting of the valence bands is only 4.8 meV suggesting that the hole is confined to the carbon sublattice. Luminescence, due to the annihilation of free excitons, has also been observed. Earlier absorption measurements have been reinterpreted, making use of the new understanding of the $6H$ SiC phonon spectrum.

Apparatus and methods for storing and releasing hydrogen

Abstract: A rechargeable device (20) that stores and discharges hydrogen is described. The device stores hydrogen in a solid form and supplies hydrogen as a gas when needed. The solid storage medium (36) may be metal hydride in a ground particle form that avoids the need for compaction or other treatment. Dividers (28) partition a container into separate chambers, each provided with a matrix (26), formed from an appropriate material like a thermally-conductive aluminum foam, which forms a number of cells (27). For proper chamber size, the ratio of chamber length to container diameter should be between about 0.5 and 2. Metal hydride particles (or other hydrogen storage medium) may be placed within the cells, which help prevent excessive particle settling. The container is provided with a hydrogen transfer port (32) through which hydrogen gas passes upon either discharging from or charging of the metal hydride particles. A filter may be placed within the port to allow hydrogen to flow but prevent particles from escaping. A heat transferring surface (23) is formed by, for instance, a channel that is thermally coupled with the aluminum foam. Fluid flows through the channel (40) to deliver or remove heat during the respective hydrogen discharging or charging processes.

Operation of /spl plusmn/100 MVAr TVA STATCON

Abstract: In 1995 a /spl plusmn/100 MVA static synchronous compensator (STATCON) was commissioned for the Tennessee Valley Authority (TVA) at the Sullivan substation in North-Eastern Tennessee, USA. This was an historic milestone in the initiative for flexible AC transmission systems (FACTS) promoted by the Electric Power Research Institute (EPRI). The TVA STATCON is the first of its kind, using GTO thyristor valves, to be commissioned in the United States, and is currently the largest installation of this type in the world. Commissioning tests have now been completed and the STATCON is operating continuously online. The demonstrated performance of the equipment has either met or exceeded expectations in all areas and has proven beyond doubt the viability of this type of equipment in high power transmission systems. This paper briefly reviews the STATCON installation and reports on the static and dynamic performance observed during commissioning.