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.

Excitation of Metastable Levels in Helium near Threshold

Abstract: The excitation of the metastable levels in helium ($2^{3}S$ and $2^{1}S$) was studied as a function of electron energy near threshold. The excitation due to essentially monoenergetic electrons was obtained by using the retarding potential method. The metastables were detected by their emission of electrons from a gold-plated cylinder. It was found that the excitation function for the $2^{3}S$ level is linear from the onset of excitation to approximately 0.4 ev above onset except for a small amount of tailing near threshold. The excitation function peaks at 0.6 ev above the excitation threshold. The value of the cross section of the $2^{3}S$ level is in reasonable agreement with the value given by Maier-Leibnitz.

Durra: a structure description language for developing distributed applications

Abstract: Durra is a language and runtime support system for developing distributed applications. In this paper, we describe the general nature of these applications, and the need for separating structural and behavioural details. A Durra user describes an application as a set of components (application tasks and communication channels), a set of alternative configurations showing how these components are connected at runtime, and a set of conditional configuration transitions that take place at runtime. We illustrate these features through examples drawn from the fault tolerance domain. We conclude with an illustration of the use of Durra in an incremental software development scenario.

Combustor with two stage primary fuel tube with concentric members and flow regulating

Abstract: A combustor for a gas turbine having a centrally located fuel nozzle and inner, middle and outer concentric cylindrical liners, the inner liner enclosing a primary combustion zone. The combustor has an air inlet that forms two passages for pre-mixing primary fuel and air to be supplied to the primary combustion zone. Each of the pre-mixing passages has a circumferential array of swirl vanes. A plurality of primary fuel tube assemblies extend through both pre-mixing passages, with each primary fuel tube assembly located between a pair of swirl vanes. Each primary fuel tube assembly is comprised of two tubular members. The first member supplies fuel to the first pre-mixing passage, while the second member, which extends through the first member, supplies fuel to the second pre-mixing passage. An annular fuel manifold is divided into first and second chambers by a circumferentially extending baffle. The proximal end of the first member is attached to the manifold itself while the proximal end of the second member is attached to the baffle. The distal end of the first member is attached directly to the second member at around its mid-point. The inlets of the first and second members are in flow communication with the first and second manifold chambers, respectively. Control valves separately regulate the flow of fuel to the two chambers and, therefore, to the two members of the fuel tube assemblies, thereby allowing the flow of fuel to the first and second pre-mixing passages to be separately controlled.

Effect of Unbalanced Voltage on the Operation of Polyphase Induction Motors

Abstract: Three-phase electric power systems generally provide voltage supply at the generating station that is well balanced in both magnitude and displacement. For varying reasons, however, some degree of voltage unbalance occurs at the point of utilization, and, depending upon the amount of unbalance, this can have an adverse effect upon the operation of polyphase induction motors. A major cause of unbalanced voltage at the point of utilization is that single-phase loads on a system are not uniformly applied to all three phases. This is particularly true for some rural electric power systems, and it can also occur in large urban power systems where heavy single-phase demands are imposed by facilities such as extensive shopping plazas. A large manufacturing plant may have well balanced incoming supply voltage, but unbalance can develop within the plant from its own single-phase power requirements if these are not uniformly spread among the three phases. Regardless of the cause, unbalanced voltage is harmful to three-phase induction motors. The paper to follow concentrates upon that aspect of unbalanced voltage.

Spontaneous degradation of aromatic polypromellitamic acids

Abstract: The reaction of pyromellitic dianhydride with a solution of a primary diamine in a solvent such as dimethylacetamide gives a viscous solutionof a polypyromellitamic acid of high molecular weight. The viscosity of the solution decreases greatly when it is aged at 35°C. Higher temperatures or the presence of water, excess amine or excess anhydride accelerate the rate of decline. A rapid early drop in viscosity has been found to be due primarily to hydrolysis by adventitious water and to exchange reactions of amine or anhydride groups with the o-carboxyamide linkage. Slow decline over a long period of time results from hydrolysis by water produced in the slow conversion of polypyromellitamic acid to polypyromellitimide. Degradation by hydrolysis also occurs when polyimide films are cast by heating the solution. The effect can be minimized by casting thin films, from which water can diffuse rapidly, or by using a chemical method, such as treatment with acetic anhydride and pyridine, to remove the water produced in imidization.