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.

Alternative Approach to the Solution of Added Carrier Transport Problems in Semiconductors

Abstract: A novel method of solving added carrier transport problems in semiconductors is presented. The usual procedure in treating problems of this type is to derive a continuity equation for charge carriers on the basis of carrier conservation, allowing for generation and recombination, and to solve this equation under appropriate boundary conditions. The resulting fluxes or currents are obtained from diffusion and drift current equations, which involve the concentrations and concentration gradients. In the formulation presented here, equations embodying conservation of flux (again with due allowance for generation and recombination) which incorporate the proper boundary conditions from the outset are solved in the steady-state one-dimensional case to yield a Green's function for the desired carrier fluxes directly. The method is more general than the commonly used continuity equation formulation in that the physical dimensions of the system and the diffusion lengths are not restricted to be large compared to the mean free path; in particular it is unnecessary to assume Fick's law for diffusion processes. Otherwise the method is equivalent to the continuity equation analysis. An example involving carrier generation in a plane region bounded on one side by a surface of arbitrary reflection coefficient (or recombination velocity) and on the other by a collecting $p\ensuremath{-}n$ junction is worked out. The results are shown to reduce to those obtained via the continuity equation in the appropriate limiting case.

Electrochemical reduction of nitrates and nitrites in alkaline nuclear waste solutions

Abstract: Sodium nitrate and nitrite are major components of alkaline nuclear waste streams and contribute to environmental release hazards. The electrochemical reduction of these materials to gaseous products has been studied in a synthetic waste mixture. The effects of electrode materials, cell design, and other experimental parameters have been investigated. Lead was found to be the best cathode material in terms of current efficiency for the reduction of nitrate and nitrite in the synthetic mix. The current efficiency for nitrite and nitrate removal is improved in divided cells due to the elimination of anodic oxidation of nitrite. Operation of the divided cells at high current densities (300–600 mA cm−2) and high temperatures (80°C) provides more efficient reduction of nitrite and nitrate. Nearly complete reduction of nitrite and nitrate to nitrogen, ammonia, or nitrous oxide was demonstrated in 1000 h tests in a divided laboratory electrochemical flow cell using a lead cathode, Nafion® 417 cation exchange membrane, and oxygen evolving DSA® or platinum clad niobium anode at a current density of 500 mA cm−2 and a temperature of 70° C. Greater than 99% of the nitrite and nitrate was removed from the synthetic waste mix batch in the 1000 h tests at an overall destruction efficiency of 55%. The process developed shows promise for treating large volumes of waste.

Apparatus and method for adapting cards designed for a VME bus for use in a VXI bus system

Abstract: A method and device for adapting a VME card for use in a VXI system are disclosed. The device resides on a circuit board that is plugged between the VXI bus and the VME card. The device provides two or more sets of VXI configuration registers. Each region of addresses normally used by the VME card is assigned to one of the simulated VXI units, and the device modifies incoming VXI addresses directed to each region so that the VME card responds to the VXI address. The VXI units simulated by the device may include one message-based device and one register-based device, so that both capabilities are available to the VME card. The device buffers signals passing between the VME card and the VXI bus, generating delays and timing signals to produce proper operation of all system components. The device provides bidirectional communication between the VME card and the VXI bus, so that the VME card can be the VXI bus master. The registers of the device can be configured manually by the user or dynamically by the VXI resource manager, permitting full operational conformance with the VXI specification. VME user-defined signals generated by the card are available on an auxiliary connector but are not passed through to the VXI bus.

Method and apparatus for eccentricity correction in a rolling mill

Abstract: A method and apparatus is disclosed for eccentricity correction in a rolling mill, in which prior to rolling, the eccentricity of the back-up rolls is measured and recorded both initially and each time the back-up rolls are changed. In an analog loop, constant roll gap is maintained by bidirectionally displacing the back-up rolls so as to maintain constant roll force in accordance with a reference roll force signal, the displacements being such as to neutralize the measured and recorded eccentricity. In a digital feedback loop, controlled by a digital computer, roll force is maintained constant in accordance with changes in the gauge of the work product, with the displacement of the back-up rolls producing a change in roll opening. The analog and digital control loops are cooperatively combined, so that the change in roll opening resulting from digital control, produces a new roll force reference for the analog loop. Effectively then, the intercooperation of analog and digital loops simultaneously produces roll eccentricity and gauge change compensation.