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.

Effect of Selected Impurities on the High Temperature Mechanical Properties of Hot-Pressed Silicon Nitride

Abstract: The effect of impurities on the high temperature mechanical properties of hot-pressed silicon nitride has been determined. Selected impurity additions were made to both relatively pure α-phase and Β-phase silicon nitride starting powders. These powders were hot-pressed to full density using 5 wt % MgO as the pressive additive. The silicon nitride hot-pressed from the α-phase powder exhibited higher strength at both 25 and 1400‡ C than that fabricated from the Β-phase powder. The impurity additions had no effect on the room temperature mechanical properties. The CaO additions had the most significant effect on the high temperature mechanical properties. In both the material hot-pressed from the α-phase and Β-phase powders, increasing CaO additions severely reduced the high temperature strength and increased the amount of non-elastic deformation observed prior to fracture. Although alkali additions (Na2CO3, Li2CO3, K2CO3) also tended to have the same effects as the CaO, the high volatility of these compounds resulted in a much reduced concentration in the hot-pressed material, thus minimizing somewhat their tendency to enhance the high temperature strength degradation. The Fe2O3 and Al2O3 had no apparent effect on the high temperature mechanical properties.

Turbine blade vibration detection apparatus

Abstract: Sensors are disposed equally about a blade row in a turbine with each sensor providing an output signal responsive to a passing blade. A blade is selected for monitoring purposes by location relative to a reference position ± some angular distance constituting a small window. As the selected blade passes a sensor, its output signal provides a pulse, and is gated. The sequential pulses of the sensors form a pulse train. An FM detector is provided to derive vibration information.

Energy dissipation and secondary electron emission in solids

Abstract: Experimental evidence is presented for the proportionality between secondary electron yield and the energy dissipated by electrons near the surface of a solid. Using measurements of the energy carried away by electrons transmitted and reflected from thin foils of aluminum and carbon, the energy dissipated in an incremental layer at the exit sur face was obtained. Simultaneous measurements of the secondary electron yield showed a close proportionality between the number of secondaries produced and the energy dissipation density near the surface independent of the incident electron energy between 1 and 10 kev. By subtracting the contribution of the backscattered electrons to the yield at the front surface of a thick aluminum target, the yield of secondaries was found to be propontional to the rate of energy loss calculated from the Bohr-Bethe theory over the energy range investigated. (auth)

Self-Diffusion of Iron in Iron Oxides and The Wagner Theory of Oxidation

Abstract: The rates of self-diffusion of iron in artifically prepared wustites of various compositions have been determined using the decrease in surface activity technique. Similar measurements are reported for artificial magnetites of nearly stoichiometric composition and for natural hematite single crystals. These data, together with appropriate thermodynamic data derived from the present study or from the literature, are used to calculate the rates of oxidation of iron and its oxides, taking as a basis the theoretical rate equations developed by Wagner. The calculations are compared with experimental rate constant data for these same reactions and are shown to provide essential confirmation for the Wagner theory. For the most part, the results are also consistent with the previously proposed transport mechanisms in the oxides of iron.

Self-calibrating microwave transponder

Abstract: A self-calibrating microwave transponder incorporating an amplifier, modulator, instantaneous frequency discriminator, memory and voltage controlled oscillator is described which may generate an RF signal in response to the carrier frequency of received low duty cycle pulse RF signals. The instantaneous frequency discriminator is used to provide an address signal from the pulse RF signals which is used to access a memory that contains the correct tuning data for the voltage controlled oscillator to generate an RF signal.