Showing papers by "Westinghouse Electric published in 1974"

A new ferroelectric memory device, metal-ferroelectric-semiconductor transistor

Abstract: The ferroelectric field effect has successfully been demonstrated on a bulk semiconductor (silicon) using a thin ferroelectric film of bismuth titanate (Bi 4 Ti 3 O 12 ) deposited onto it by RF sputtering. A new memory device, the metal-ferroelectric-semiconductor transistor (MFST); has been fabricated. This device utilizes the remanent polarization of a ferroeletric thin film to control the surface conductivity of a bulk semiconductor substrate and perform a memory function. The capacitance-voltage characteristics of the metal-ferroelectric-semiconductor structure were employed to study the memory behavior. The details of the study together with a preliminary results on the MFST are presented.

Harmonic Mixing with an Anti-Parallel Diode Pair

Abstract: An analytical and experimental investigation of the properties of an antiparallel diode pair is presented. Such a configuration has the following unique and advantageous characteristics as a harmonic mixer: 1) reduced conversion loss by suppressing fundamental mixing products; 2) lower noise figure through suppression of local oscillator noise sidebands; 3) suppression of direct video detection; 4) inherent self protection against large peak inverse voltage burnout. These results are obtained without the use of either filters or balanced circuits employing hybrid junctions.

Predictions of arc temperature profiles using approximate emission coefficients for radiation losses

Abstract: Coefficients are calculated for the net emission of radiation per cc from the center of cylindrical isothermal plasmas of various temperatures and radii. Coefficients are given as a function of temperature and radius for the D lines of sodium vapor at 250 torr and for the continuum radiation of air at 1 and 30 atm. These coefficients are used in the Elenbaas Heller equation to derive temperature profiles of wall stabilized arcs e.g. for 4·5A with a radius of 0·35 cm in sodium vapor at 250 torr and 10,000 and 20,000A with a radius of 1 cm for air at 30 atm. Comparisons are made with calculated temperature profiles where self absorption effects and the radiation transfer are treated exactly, but still assuming thermodynamic equilibrium. It is found that the approximation using the net coefficients yields central arc temperatures and electric field strengths for a given arc current accurate to 10 per cent. Computation time for the approximate calculation is more than an order of magnitude less than for the calculation where radiation transfer is treated exactly. Thus the approximation facilitiates an account of line radiation for arc plasmas having complex spectra.

High‐Temperature Strength Behavior of Hot‐Pressed Si3N4: Evidence for Subcritical Crack Growth

Abstract: The high-temperature strength of commercial hot-pressed Si3N4 was obtained for (1) two materials with different impurity contents, (2) the weak and strong material directions, (3) air and Ar ambients, and (4) different stressing rates. Strength degradation occurred at a lower temperature for the less pure material; both material directions exhibit the same rate of strength degradation. The testing ambient did not affect strength. The strength at temperatures ∼1200°C depended strongly on stressing rate. The presence of rough, crack-shaped topographical features on the fracture surface and the observation of large cracks that formed during stressing are reported as evidence for subcritical crack growth at high temperatures. It is hypothesized that accelerated creep caused by grain-boundary sliding at preexisting crack fronts is the mechanism responsible for the observed subcritical crack growth.

Block oriented random access memory

Abstract: A block oriented random access memory (BORAM) is disclosed as comprising a plurality of memory arrays of metal-nitride-oxide semiconductor (MNOS) memory elements. Each memory array includes a plurality of the MNOS memory elements disposed in rows and columns, and serial or sequential means such as a shift register for writing and reading data to and from the memory elements through column conductors associated with each column of the memory elements. A temporary storage means such as a latch is inserted between each stage of the shift register and the column conductor, whereby a multiplexing function can be performed between the stage outputs of the shift register and the columns of the memory elements. Address means is provided for the rows of memory elements, whereby a row may be selected for entry of data through its associated column conductor. In one illustrative embodiment, a plurality of such assemblies is assembled into a block capable of being separately addressed, wherein each such assembly is capable of storing one bit of a multi-bit word of data. In turn, a plurality of such blocks is assembled to form the block oriented random access memory, wherein each such block may be randomly accessed, and the data therein sequentially read and written.

Shaping of Axisymmetric Bodies for Minimum Drag in Incompressible Flow

Abstract: A method is presented for the automatic synthesis of minimum drag hull shapes for axisymmetric vehicles of specified enclosed volume and constant speed submerged in incompresible, nonseparating, noncavitating flow at zero incidence. The computer-oriented optimization procedure does not consider propulsion or maneuvering; drag reduction is accomplished solely through manipulation of the vehicle hull shape. The selected optimization formulation is a nongradient algorithm in a finite, constrained parameter space. This study considers an eight-parameter class of rounded-nose tailboom bodies constrained to be well behaved as determined by previous hydrodynamic experience. The drag model, for nonseparating flows at zero incidence, is based on classical hydrodynamics and consists of computer programs from work available in the literature; the model is representative of state-of-the-art drag prediction methods. By exploiting laminar flow while avoiding turbulent separation, a body with a drag coefficient one-third below the best existing laminar design has been obtained. The evidence suggests that the method produces realistic hull shapes useful in engineering design. The optimization procedure is independent of any particular drag model so that the effects on minimum drag shapes due to alternate drag models can be studied.

Z slot antenna

Abstract: An improved antenna of a coaxial type utilizing Z-shaped slots disposed in the outer conductor to provide an omnidirectional antenna pattern. Current coupling to the slots is achieved by means of the transverse portion of the Z slot. Detuning effects due to the presence of a transmission line are compensated for by dielectrically loading the slots with a dielectric cover over the coaxial line and/or by lengthening the longitudinal arms of the Z. The longitudinal spacing between each slot and the length of the transverse portion of each slot are chosen while considering all line effects to obtain the required phase and amplitude relationships. The antenna consequently requires no additional coupling, tuning or phasing devices mounted within or without the coaxial line.

A Validation of the Color-Preference Index

Abstract: Four fluorescent lamps of daylight chromaticity, and with varying Color-Preference Index (CPI), illuminated an array of fruit, vegetables, breads and meat. The lamps were rated in order of preference for the coloration of this array by 267 observers. Excellent correlation of observer preference with CPI, as well as with the prime-color content of the spectral power distributions of the lamps, served to validate the CPI and Judd's assignment of preferred chromaticities of identifiable objects.

Metal/air cells and improved air electrodes for use therein

Abstract: Air electrodes for use in electrochemical energy cells which comprise a hydrophilic layer and a hydrophobic layer laminated thereto. The hydrophilic layer essentially comprises a hydrophilic composite which includes I. an oxygen absorption/reduction carbon, Ii. a material selected from the group consisting of A. CuWO 4 , NiWO 4 , CoWO 4 and WC with 1-20 wt. % Co. for a unifunctional electrode, or B. WS 2 , WC, and WC with 1-20 Wt.% Co. for a bi-functional electrode, and Iii. a nonwetting agent containing a polytetrafluoroethylene. A metal current collector is molded into the composite to form a substantially flat hydrophilic layer. A catalyst is preferably incorporated into the composite of a bifunctional electrode to increase cycling life. The hydrophobic layer, comprising a sheet of porous fluorinated ethylene propylene, polypropylene or polytetrafluoroethylene, is laminated to the hydrophilic layer to complete the air electrodes of the invention.

Translucent Sintered MgAl2O4

Abstract: A translucent polycrystalline MgAl2O4 ceramic was prepared from finely divided coprecipitated spinel in which a small amount of CaO added as a sintering aid was uniformly distributed. The CaO promotes densification through the formation of a liquid phase at the sintering temperatures. Depending on the sintering treatment, the relative density of the sintered spinel was 99.7 to ∼100% of theoretical. The in-line optical transmission was > 10% from 0.3 to 6.5 μm. Total transmission in the visible region was between 67 and 78%.

Hot-Pressing Behavior of Si3N4

Abstract: The densification behavior of Si3N4 containing MgO was studied in detail. It was concluded that MgO forms a liquid phase (most likely a magnesium silicate). This liquid wets and allows atomic transfer of Si3N4. Evidence of a second-phase material between the Si3N4 grains was obtained through etching studies. Transformation of α- to β-Si3N4 during hot-pressing is not necessary for densification.

Insulated-gate thin film transistor with low leakage current

Abstract: An insulated-gate thin film transistor is provided with low leakage drain current. A second semiconductor layer makes contact with the source electrode and the semiconductor layer forming the channel of the transistor at least between the source and drain electrodes. The second semiconductor layer is of opposite type conductivity from the channel semiconductor layer and preferably forms a PN heterojunction with the channel semiconductor layer. Alternatively, a metal layer may be used in place of the second semiconductor to form a Schottky-barrier junction with the channel semiconductor layer instead of a PN junction. Preferably, the channel semiconductor layer and the second semiconductor layer or the metal layer are sequentially evaporation deposited through the same deposition mask onto a substrate from evaporant sources spaced substantially different distances from the substrate so that the sequential layers are deposited on first and second overlapping areas of the substrate.

Application of Epoxy Resins in Electrical Apparatus

Abstract: This summarizes the important physical and electrical characteristics of these diverse and highly useful insulating materials. Factors of chemical structure which influence the resulting resin properties are discussed. The great variety of properties which can be achieved through variations in this one class of resins is emphasized. A range of applications of these resins is mentioned and illustrated.

Monitoring system for elevator installation

Abstract: A monitoring system for off-site monitoring, traffic study and/or trouble shooting of elevator installations. Communication between the remote monitoring site and a selected elevator installation is established via a direct dial telephone link. The remote monitoring site includes visual display means for displaying the operation of the selected elevator installation in real time, means for storing and analyzing status signals from the elevator installation, as well as for printing out the results of such an analysis, and control means for entering commands to be executed by the elevator system. In addition to observing the operation of the complete elevator installation, any combination of software and/or hardware at the elevator installation may be selectively monitored by substituting a system processor and/or simulated car controllers, both of which are located at the monitoring site, for those located at the elevator installation, and operating selected components at the elevator installation along with those at the monitoring site via the communication link. The operation of the resulting hybrid system including its response to commands initiated at the monitoring site may be displayed and/or analyzed, as desired.

Fabrication and some applications of large-area silicon field emission arrays

Abstract: A method of fabricating large-area arrays of sharply-pointed field emitters at densities up to 1·5 × 10 5 per cm 2 from single crystal silicon wafers is described. The point emitters are formed by etch-undercutting a precision oxide pattern which is delineated on the silicon surface by projection photolithography. Observations indicate that emitters with very small tip dimensions in the 200Arange are formed. In the presence of an external electric field, such as produced by a voltage applied to a closely-spaced, planar anode, multiple-emitter arrays are shown to field-emit electrons uniformly over areas up to 3 cm dia. Two important applications currently being explored, are discussed: (1) High resistivity, p -Si has been utilized to develop experimental field emission photocathodes with which field emission imaging has been demonstrated. These photoemitters exhibit very high photo-sensitivities at visible and near i.r. wavelengths. For example, at 0·86 μm, the measured quantum efficiency is 25 per cent which is about five-times higher than the red-sensitive S-20 photocathode and comparable to the highest reported sensitivities of the III–V photosurfaces; (2) N -type emitter arrays show considerable promise as high current, cold cathodes and total emission currents of 1/4 A from 1 cm 2 areas of 100 Ω-cm n -type emitters have been obtained. Measurements were made under pulse conditions because of anode dissipation considerations.

Computer controlled security system

Abstract: A bidirectional electronic interface couples remote sensing security transducers such as fire and burglar monitoring devices to a computer such that the circuitry of the bidirectional electronic interface functions to both transmit signals from the remote sensing transducer to the computer for analysis and processing and transmit control and data information to remote control and monitoring stations. The computer scans the content of the bidirectional electronic interface for remote transducer information with the bidirectional electronic interface serving as a storage apparatus. The computer is programmed to respond to the information presented by the bidirectional electronic interface to initiate predetermined control and data recording functions for both direct activation of remote apparatus and for transmittal of control signals through the bidirectional electronic interface circuitry to remote apparatus. The flexibility provided by the bidirectional electronic interface circuitry provides for effective and efficient utilization of conventional computer capability in a security system. Circuitry of the type disclosed herein has been described in detail in U.S. Pat. No. 3,805,234 entitled "Digital Data Transmission Systems" issued Apr. 14, 1974 and U.S. Pat. No. 3,910,322 entitled "A Test Set Controlled By A Remotely Positioned Digital Computer", both of which have been assigned to the assignee of the present invention.

The semiconductor field-emission photocathode

Abstract: The recently developed large-area field-emission photocathode is described. It consists of a finely spaced array of point emitters fabricated by etching of p-type silicon or other semiconductor. Uniform emission over areas of 6-7 cm2have been obtained. For Si, the spectral response extends from 0.4 to 1.1 µm. Quantum yields of 25 percent at 0.86 µm have been measured, which is about five times the value reported for the extended S-20 photocathode and comparable to the best III-V photoemitters. Calculations indicate that quantum yields of up to 40 percent at 0.86 µm and 28 percent at 0.9 µm are attainable with the present photocathode structures. For low dark current densities, photocathode cooling to temperatures approaching 77 K must be employed at present. The dark current is shown to be dominated by surface-generated electrons in the space-chargeregion of the emitters. Effects of phosphorus gettering and annealing treatments on dark current are discussed, and the spatial frequency response of the device is determined. The results of a computer study show that the field intensification factor of p-semiconductor field emitters behaves quite differently from that of metallic emitters.

Wide range catalytic combustor

Abstract: A catalytic combustor arrangement for use with a gas turbine power plant, has independently regulatable fuel injection elements disposed upstream of a discrete array of passageways disposed between the fuel injection elements and a catalytic reaction member. The centermost fuel injection elements of each combustor may function alone which will permit efficient idling operation of the power plant. The passageways will maintain the flow of fuel and air to only the central portion of each catalytic reactor element thus providing the efficient, low speed, idling, operation of the turbine. As additional fuel injection elements are activated, additional portions of the catalytic reaction member perform the combustion function at the desired level of turbine operation. Thus a wide range of operating conditions of the gas turbine is efficiently permitted with the regulatable fuel injection arrangement therewith.

Electrolytic decomposition of water

Abstract: Electrolysis and catalytic thermochemistry are combined to decompose water while minimizing the energy demanded to accomplish the decomposition. The electrolyte is H2SO3 produced by supplying SO2 and the water to be decomposed to the electrolyzer. The H2SO3 is ionized and oxidized in the electrolyzer into SO4 and H ions and electrons. Hydrogen is derived from the negative electrode of the electrolyzer. The SO4 is combined with H to form H2SO4. The H2SO4 is removed from the electrolyzer to the thermochemical unit, concentrated and decomposed predominately into H2O, SO2 and O2. The SO2 is liquefied and thus separated from the O2 which is derived from the thermochemical apparatus. The liquid SO2 is vaporized and returned to the electrolyzer.

Combined cycle electric power plant and a heat recovery steam generator having improved temperature control of the steam generated

Abstract: A combined cycle electric power plant includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. The steam generator includes a superheater tube through which a fluid, e.g. water, is directed to be additionally heated into superheated steam by the exhaust gas turbine gases. An afterburner further heats the exhaust gas turbine gases passed to the superheater tube. The temperature of the gas turbine exhaust gases is sensed for varying the fuel flow to the afterburner by a fuel valve, whereby the temperatures of the gas turbine exhaust gases and therefore of the superheated steam, are controlled. Further, override signals are generated to prevent the temperature of the superheated steam from falling below a predetermined minimum level and for preventing the temperature and pressure of the superheated steam from exceeding maximum levels.

Non-Elastic Deformation of Polycrystals with a Liquid Boundary Phase

Abstract: A conceptual view is taken to understand the deformation behavior of a polycrystal with a liquid (or a quasi-elastic) boundary phase. The analysis is based on the theories of liquid adhesives, the fracture of liquids and the concepts of fracture mechanics. It is shown that boundary separation rather than boundary sliding is the step that controls the deformation rate. Using this principal result, it is shown that the deformation behavior of a polycrystalline material with a viscous boundary phase is controlled by the flow characteristics, the volume content of the boundary phase and the microstructure features of the polycrystal (viz., voids, solid inclusions and cracks). Polycrystalline materials with a viscous boundary phase will exhibit a much greater rate of deformation in tension than in compression.

Control apparatus for controlling the operation of a gas turbine inlet guide vane assembly and heat recovery steam generator for a steam turbine employed in a combined cycle electric power generating plant

Abstract: A combined cycle electric power generating plant includes gas and steam turbines and a heat recovery steam generator recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. The gas turbine includes a plurality of variably set guide vanes whose position may be set to determine the inlet flow to the gas turbine. Guide vane control apparatus is provided to limit the inlet guide vane position as a function of gas turbine compressor inlet temperature in accordance with a desired gas turbine exhaust flow, and to match the gas turbine exhaust flow to the steam requirements of the steam generator as in turn determined by the load placed upon its steam turbine. In addition, an afterburner is provided to supplementally heat the exhaust gas turbine gases before they are directed to the steam generator. During the startup, the afterburners are operated to supply supplemental heating to the gas turbine exhaust gases supplied to the steam generator whereby the temperature of the steam passed to the steam turbine is maintained at a minimum level. Further, the afterburners are fired to permit additional loading to be placed upon the steam turbine.

Apparatus and method for installing elevator hoistway equipment

Abstract: An elevator system has a hoistway in which guide rail sections are mounted end-to-end to form guide rails for an elevator car frame or sling and for a couterweight. To install the guide rails a rig is lowered by a hoist towards the lower end of the hoistway. An end of a guide rail section is connected to the rig for each guide rail desired. The rig is raised in steps and each step is equal to the length of a guide rail section. At the end of each step an end of an additional guide rail section is connected to the lower end of each row of suspended guide rail sections until the desired guide rail length is achieved. The points of connection of the guide rail sections to the rig are adjusted to locate each row of guide rail sections in the desired position and the rig is blocked in position. The lowest section of each row is next secured to the building structure housing the hoistway and a car frame or sling is mounted on the lowest sections of guide rails. The sling is raised upwardly in steps. At each stop of the sling workmen operating from the sling secure the adjacent parts of the guide rail sections to the building structure and/or install hoistway apparatus on adjacent parts of the hoistway.

Transponder for an automatic vehicle identification system

Abstract: This disclosure relates to an inductively powered type of electronic transponder for identifying a moving object passing an interrogation area. The transponder includes a tuned inductive-capacitive pick-up circuit for receiving interrogating signals. The picked up interrogating signals are rectified to produce d.c. operating power and are applied to a frequency divider for producing a frequency related transmission signal and clock data rate pulse. A latching circuit enables a shift register so that the clock pulses serially shift out binary encoded data from the shift register. The encoded data is fed to a logic network which is coupled to a balanced switching amplifier for phase modulating the transmission signal for propagation into the interrogation area.

The preparation and characterization of beta-tungsten, a metastable tungsten phase

Abstract: A metastable phase of tungsten (β-W) is obtained by hydrogen reduction of WO3 at 500°C. Five different samples of WO3 have been used to investigate the effects of oxide surface area and impurity content on the reduction process. The initial oxide samples and the reduction product have been characterized by scanning electron micrographs, and measurements of the oxygen content of β-W have been performed. It is concluded that β-W is not a suboxide as previously reported by Hagg and Schonberg. The effect of other elements on the β-W to α-@#@ W transformation temperature has been investigated.

Combined cycle electric power plant and a heat recovery steam generator having improved boiler feed pump flow control

Abstract: A combined cycle electric power plant includes gas and steam turbines and a steam generator for recovering the heat in the exhaust gases exited from the gas turbine and for using the recovered heat to produce and supply steam to the steam turbine. The steam generator includes an economizer tube and a high pressure evaporator tube and a boiler feed pump for directing the heat exchange fluid serially through the aforementioned tubes. A condenser is associated with the steam turbine for converting the spent steam into condensate water to be supplied to a deaerator for removing undesired air and for preliminarily heating the water condensate before being pumped to the economizer tube. Condensate flow through the economizer tube is maintained substantially constant by maintaining the boiler feed pump at a predetermined, substantially constant rate. A bypass conduit is provided to feed back a portion of the flow heated in the economizer tube to the deaerator; the portion being equal to the difference between the constant flow through the economizer tube and the flow to be directed through the high pressure evaporator tube as required by the steam turbine for its present load.

Ground fault protector with arcing fault indicator

Abstract: A ground fault detector having an indicator which indicates the presence of a ground or similar fault in an electrical line to be protected where the fault current is not of sufficient magnitude to cause the ground fault indicator to trip a circuit breaker to thereby interrupt the circuit in which the ground fault current is flowing. The indicating circuit provides a recognizable warning that a ground fault has begun or is in progress so that appropriate steps may be taken to cure the fault to locate the fault, or to indicate the relative magnitude of the fault current before it worsens.

Vehicle movement control system for railroad terminals

Abstract: Data and voice communication links are provided between a movement direction center, a data processing center, and all mobile work units of a railroad terminal control system. A work assignment input from the movement direction center, e.g., an order to assemble a train, activates the data processing center to prepare and transmit to the selected switching locomotive an itemized work list, which is recorded in printed form at the locomotive to serve as specific instructions for accomplishing the assignment. The work unit crew reports readiness to begin and subsequent completion of each work list item. The data processing center responds to these and other information inputs, e.g., vehicle movement indications, to check the work done and to remotely establish the field conditions, e.g. track routes, necessary to accomplish the successive work items until the entire assignment is completed. The data processing center sets up the next route and authorizes the locomotive crew to perform the next work step only when the checking process indicates that the prior work step was correctly completed.

Control system for sensing the vibration and lateral force on a cutting tool

Abstract: A system for sensing the vibration and lateral force in a cutting tool for the purpose of keeping both these operating parameters within tolerable limits. A piezoelectric crystal is mounted in the chuck supporting the cutting tool. The mechanical stresses on the crystal produce an electrical signal which is then separated into vibration and lateral force components. The negative d.c. analog voltages of these components are summed with a positive d.c. voltage analogous to the programmed feed rate, the algebraic summation resulting in an adaptive control voltage which is used to modulate the spindle power in accordance with the ambient vibration and force.