Showing papers by "Westinghouse Electric published in 1972"

Phase instabilities during high temperature exposure of 316 austenitic stainless steel

Abstract: Although Type 316 austenitic stainless steel is widely used in steam generating plants and nuclear reactors the knowledge about aging reactions, nature of precipitates, and precipitation kinetics during high temperature exposure is limited. Time-temperature-precipitation (TTP) diagrams were determined between 400° and 900°C for up to 3000 hr as a function of carbon content, solution treatment temperature, and cold work. The nucleation and growth phenomena, morphology, and composition of the various carbide (M23C6, M6C) and intermetallic phases (σ, χ, η were determined. The complex sequence of phase instabilities can be explained on the basis of the carbon content, effect of molybdenum and chromium on the carbon solubility, thermodynamic stability of the phases, and the kinetics of the various precipitation reactions.

The j integral as a fracture criterion

Abstract: The path independent J integral, as formulated by Rice, can be viewed as a parameter which is an average measure of the crack tip elastic-plastic fied. This together with the fact that J can be evaluated experimentally, makes a critical J value an attractive elastic-plastic fracture criterion. The critical J value fracture criterion refers to crack initiation under plane strain conditions from essentially elastic to fully plastic behavior. Experiments supporting the validity of a critical J value fracture criterion are presented in this paper. Values of the J integral were determined experimentally for two steel alloys, one of low and the other of intermediate strength. A review is given of the analytical support for the critical J value fracture criterion. The range of applicability of the critical J value concept, its limitations, and its advantages are also discussed. /Author/

The high-temperature oxidation, reduction, and volatilization reactions of silicon and silicon carbide

Abstract: A thermochemical analysis was made of the oxidation, reduction, and volatilization reactions which occur in the Si-O-C system. One characteristic feature is the high SiO(g) and SiO(g) + CO(g) pressures at the Si(s)-SiO2 and SiC(s)-SiO2(s) interfaces. Active oxidation with weight losses and passive oxidation with weight gains were found on oxidizing Si(s) and SiC(s) in low oxygen pressures above 1000°C. Rapid oxidation was related to the SiO(g) and SiO(g) + C0(g) pressures at the Si(s) or SiC(s)-SiO2(s) interfaces.

Characterization of thin-oxide MNOS memory transistors

Abstract: A direct tunneling theory is formulated and applied to high-speed thin-oxide complementary metal-nitride-oxide-silicon (MNOS) memory transistors. Charge transport in the erase/write mode of operation is interpreted in terms of the device threshold voltage shift. The threshold voltage shift in the erase/write mode is related to the amplitude and time duration of the applied gate voltage over the full range of switching times. MNOS memory devices ( X_{o}=25 \Aring, X_{N} = 335 \Aring ) exhibit a \Delta V_{th} = \plusmn3 V for an erase/write t_{p} = 100 ns, which corresponds to an initial oxide field strength E_{ox}= 1.2 \times 10^{7} V/cm. The direct tunneling theory is applied to the charge retention or memory mode in which charge is transported to and from the Si-SiO 2 interface states. The rate of charge loss to interface states is influenced by electrical stress which alters the interface state characteristics. We discuss the fabrication of complementary high-speed MNOS memory transistors and the experimental test procedures to measure charge transport and storage in these devices.

Digital computer monitored and/or operated system or process which is structured for operation with an improved automatic programming process and system

Abstract: An industrial production or other operational system is established by connecting apparatus which implements system operations to a digital computer system using an interface system. Machine readable definitions of events, of executable jobs, and of system variables are prepared for computer entry and ultimately for configuration of the system apparatus into an entity having operational characteristics corresponding to the entered definitions. The definitions of system variables may include definitions of signals which are coupled between the system apparatus and the computer through the interface system, and such signals may be put to system monitoring or control uses or both of these uses in the structured system. Some of the definitions may be computer programs, but most are preferably definitions of the system configuration written out in a language which a systems engineer can understand and use. Generally, definitions may include designators which are names or numbers. Any definition may refer to an event, a job, or a variable by making reference to the designator that is included in the definition of the event, the job or the variable. Executable job definitions may, by referring to event designators, specify specific events which are to trigger their execution--or example, variable scanning events or variable change-of-state events--or they may specify that they are to be periodically executed at a specified frequency or rate. The definitions are processed individually by an off-line preliminary processor which converts the systems engineer's language into a numeric language intelligible to processing programs within the computer system or to the computer system itself. The definitions are then fed into the computer system. Automatic programming means within the computer system establish all the necessary linkages between each new definition and previously entered definitions and other operative portions of the computer system so as to implement each definition relative to the system apparatus as soon as the definition is received and so as automatically to establish the desired system operating configuration through the controlled operation of the computer relative to the interfaced system apparatus. Definitions may be deleted from the computer system at any time and in any order by the automatic programming means without shutting down the system, and the system operating configuration may thus be modified whenever necessary or desirable. Following such deletions, the automatic programming means eliminates linkages which are no longer required and compresses the tables in which such linkages may be stored so as to maximize the storage space which is available for additional new definitions and their associated linkages.

Liquid crystal image display panel with integrated addressing circuitry

Abstract: A flat, non-vacuum display panel using a lightmodulating layer of a voltage-dependent, optically active material of twisted nematic liquid crystals, X-Y matrix addressed by an array of coextensive, vacuum-deposited, interconnected thin film transistors which are scanned from the periphery of the flat panel by electronic shift registers. The panel is illuminated from the rear by white light, which passes a mosaic color filter for color television display. The invention hereindescribed was made in the course of or under a contract with the U.S. Air Force.

Color-Discrimination Index

Abstract: The area of the gamut, in a uniform chromaticity-scale diagram of the chromaticities of a standard array of object colors, is taken to be a measure of color-discrimination capability of an illuminant. The 1960 CIE u, v chromaticity diagram, and the eight test colors of the interim method for computing a color-rendering index, are used for demonstration. Correlation with long-standing subjective evaluations of color rendering of eight commercial lamps is shown. Artificial illuminants excel daylight and the equal-energy spectrum in the gamut of chromaticities of illuminated samples.

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.

Strength Degradation and Crack Propagation in Thermally Shocked Al2O3

Abstract: Strength degradation and crack propagation in Al2O3 are shown to depend on the initial strength and grain size of the material. The strengths of single-crystal sapphire and polycrystalline Al2O3 specimens with grain sizes of 10, 34, and 40 μm decreased discontinuously at the critical quenching temperature. In contrast, the strength of polycrystalline Al2O3 with a grain size of 85 μm decreased gradually as the quenching temperature increased. The strength retained after thermal shock and the extent of crack propagation decrease with increasing initial strength and grain size, respectively, in Al2O3.

Photoluminescence of Radiation Defects in Ion-Implanted 6 H SiC

Abstract: Radiation defects were introduced into $6H$ SiC by ion implantation and by electron bombardment. The defects produce a new low-temperature luminescence that is independent of the implanted ion, and one portion, the ${D}_{1}$ spectrum, persists after a 1700\ifmmode^\circ\else\textdegree\fi{}C anneal. A comparison of the ${D}_{1}$ spectrum in ion- and electron-bombarded samples shows that its intensity is strongly dependent on defect concentration, suggesting that the luminescence center is a pure-defect complex, possibly a divacancy. The ${D}_{1}$ spectrum, which was previously observed in cubic SiC, has a strong vibronic structure with localized and resonant modes. In $6H$ SiC it is repeated three times, due to the three inequivalent sites in this polytype. ${D}_{1}$ has an unusual temperature dependence, the low-temperature (1.4\ifmmode^\circ\else\textdegree\fi{}K) spectrum being extinguished as the high-temperature (77\ifmmode^\circ\else\textdegree\fi{}K) form is activated. The abrupt change of spectrum is attributed to a lattice distortion at the low temperature. The changes in luminescence on annealing are correlated with changes in electrical properties observed in ion-implanted samples by Marsh and Dunlap.

Formulation of a Reflector-Design Problem for a Lighting Fixture

Abstract: The problem of designing a reflector to distribute the illumination of a nonisotropic point source on a plane aperture according to a pre-assigned pattern is analyzed. An integral equation and equivalent partial differential equation are derived. The form of the latter reveals this reflector-design problem to be a singular elliptic Monge–Ampere boundary-value problem.

Superconductivity in the TiO and NbO systems

Abstract: This paper presents electrical resistivity and superconductivity studies for the B1 (NaCl) structure oxides of titanium, vanadium, and niobium. In samples of nominal composition TiO x , VO x , and NbO x ,x was varied from 0.8 to 1.2. It was found that all three of these oxides exhibit room-temperature electrical resistivities characteristic of metallic behavior. With decreasing temperature, the resistivity drops steeply in the case of NbO x , but remains steady or rises somewhat in the case of TiO x and VO x , depending on the exact value ofx. It is suggested that in TiO x and VO x there is a large resistivity component due to scattering of carriers by disordered vacancies. Superconductivity was observed in NbO x (T c=1.38 K,x=1.0) and TiO x (T c=1.0 K,x=1.07). In the latter case the material showed a well-defined maximum ofT c as a function of composition, withT c 1.20. Several VO x samples remained normal to 0.07 K.

Laser properties of nd(+3) and ho(+3) doped crystals with the apatite structure.

Abstract: A great variety of compounds occur in nature or have been synthesized in the laboratory that crystallize with the apatite structure. We have investigated a number of the apatites and found them to be excellent laser hosts for neodymium and holmium. The apatites described in this paper were grown using the Czochralski method, have low optical losses in the pump and emission spectral regions for neodymium and holmium, and the hosts have been developed to readily accept large concentrations of doping ions. This paper describes the crystal growth, physical properties, spectroscopy, and laser performance of this family of new laser materials.

Interruption ability of vacuum interrupters subjected to axial magnetic fields

Abstract: Two vacuum interrupters equipped with 7 cm-diameter electrodes have been power tested with and without the presence of an axial magnetic field during arcing. The field strength was 2×10−5 teslaper arcing ampere, with a negligible field at a current zero. Observations with both interrupters at arc currents of 10–25 kA (r.m.s.) revealed that the field suppressed the peak arc voltage at electrode spacings of approximately 0.4 cm by about 30%. The current-interruption ability of one interrupter increased by at least 20%, and the magnetic field also increased the interruption probability of the second interrupter. These effects are attributed to plasma confinement by the field, which reduces the total input power to the interrupter and increases the threshold current associated with anode-spot formation. The plasma confinement also reduces the probability of arcing to the vapour-condensation shield.

Effect of Conducting Particles on AC Corona and Breakdown in Compressed SF6

Abstract: This paper describes studies of the effects of conducting particles on breakdown phenomena in compressed SF6 under alternating voltage conditions. Results with free particles of different shapes and materials are compared with those obtained with fixed particles for both parallel-plane and coaxial electrode geometrics. Calculations of the particle motion and of the energy in microdischarges between particle and electrodes are used to suggest mechanisms by which breakdown is initiated. It is shown that the breakdown voltage, which can be as low as 10% of the uncontaminated value, is markedly dependent on particle shape, size and material, and that the nature of the motion in alternating fields is important in establishing conditions for free- particle-triggered breakdown.

The extent and nature of the strength-differential effect in steels

Abstract: Tensile and compressive stress-strain curves were obtained for several types of microstructures in a variety of steels. The strength-differential effect, previously found in martensitic structures, was present in lower, intermediate, and upper bainite and in Widmanstatten ferritepearlite as well as in ultrafine-grained martensite. An equiaxed ferrite-pear lite structure showed no strength differential. The strength differential in martensite increased as test temperature was decreased below room temperature. In several series of tests, the same specimen design was used in tension and in compression to eliminate possible strength variations due to variations in specimen preparation. Several theories which have been proposed for the strength-differential effect are discussed with respect to the present results, and it is shown that most of the previous suggestions are invalid.

Time compression of audio signals

Abstract: The invention pertains to a technique for time-compressing audio signals without disturbing the relative position of the audio samples through the use of a time buffer store and a subsequent FM recording of the time-compressed audio signal in a format similar to video signals and the subsequent demodulation of the FM signals and time expansion of the signals to produce the original audio signals. The use of FM modulation and demodulation of a type similar to that used with video information for recording and transmitting time-compressed audio information permits common processing of audio and video information and the utilization of standard video transmission and video tape and video disc recorders to accommodate audio as well as video information.

Low parasitic capture fuel assembly structure

Abstract: The basic fuel assembly structure for a nuclear reactor comprises a skeleton made up of individual hollow tubes composed of a zirconium base alloy, such as Zircaloy, and held in place by Inconel or stainless steel grids disposed between stainless steel end nozzles at the top and the bottom of the structure. The tubes serve as guide thimbles for cylindrical control elements strategically located in a square array of fuel rods held in place by spring fingers on the "egg-crate" grids. The guide thimbles are attached to the top and bottom nozzles and the grids by mechanical joints without welding dissimilar metals.

High-Speed Distance Relaying Using a Digital Computer I - System Description

Abstract: An experimental general-purpose process-control digital computer system provides high-speed phase-and ground-distance fault protection of one 230 kV transmission line. The stored program performs all of the relaying functions using the output of an analog-to- digital converter which reads the instantaneous value of the power- system currents and voltages. Model line tests described in a companion paper (II -Test Results) form the basis for preliminary performance evaluation. An automatic oscillograph and diagnostic programs will allow a study of field performance.

Nuclear techniques for detecting the presence of explosives

Abstract: The invention pertains to a nuclear technique for monitoring objects such as luggage and parcels to determine the presence of specified nitrogen containing materials such as explosives as a function of the nitrogen content and concentration profile. Objects to be analyzed to determine the presence of nitrogen are subjected to a thermal neutron environment and the gamma ray radiation produced by the object in response to nitrogen reactions is monitored by gamma ray detectors. The gamma ray detectors produce indications of the nitrogen content of the object and the concentration profile of the nitrogen in the object. The information provided by the gamma ray detectors is processed to determine if the measured nitrogen content and concentration corresponds to a class of nitrogen containing material of interest, i.e. explosives.

Apparatus for treating industrial and domestic waste waters

Abstract: A system for treating waste waters including a pair of concentric tanks forming a space therebetween which serves as an aeration chamber. Untreated but screened waste water is discharged into the (annular) space and withdrawn therefrom by a pump which passes the liquid through an oxygenating device which induces air into the liquid. The liquid is then circulated through long tubing wound around the outside peripheral surface of the tank to obtain intimate contact between the gas, liquid and solids therein and to convert dissolved material into insoluble material by a conventional biochemical process. The liquid thus processed in the tubing is introduced into the central or inner tank where the treated solids rise to the surface for recycling in the system while the liquid effluent is filtered and discharged to a river or stream.

Electrical system with programmed computer control and manually initiated control means

Abstract: An automatically controlled electrical system controls a plurality of loads in the functions of load resetting, logical control, load sequencing, overload evaluation, and load shedding with single point control. A data entry and display means provides a manual interface with the system. The system utilizes remotely controlled power switching and circuit protective devices. A small general purpose computer is used to effect control functions by, preferably, multiplexed control signals. The computer directs the control signals to and from the appropriate switching devices and it also provides capability to program for automatic control, sequencing and self-checkout functions.

Microminiature ganged threshold accelerometers compatible with integrated circuit technology

Abstract: The device described permits threshold acceleration detection in a wide range from a few ten's of g's up to maybe 100 000 g's. It is a threshold sensing device with an extremely high on-to-off resistance ratio. The device consists of a flexible metal beam and an associated contact pad, which is activated by the force of the beam's inertial mass when being accelerated in a direction normal to the contact plane. The mechanical and electrical operation of the accelerometer is analyzed and expressions are given for the relationship between beam deflection, acceleration detection level, and various required beam dimensions. A batch fabrication procedure is demonstrated and acceleration test results up to 8000 g's are reported for multiple ganged accelerometers.

Solid electrolyte cell

Abstract: 1. A METHOD OF MAKING A SOLID ELECTROLYTE CELL COMPRISING: (A) PREPARING A SHEET OF AN ELECTROLYTE COMPOSITION COMPRISING A FINELY-DIVIDED, SOLID, SINTERABLE ELECTROLYTE HAVING IONIC VACANCIES CAPABLE OF CONDUCTING A CARRIER, AND A FIRST SYNTHETIC, ORGANIC RESIN WHICH DOES NOT LEAVE A RESIDUE WITH N AN ELECTRODE COMPOSITION (B) COVERING SAID SHEET WITH AN ELECTRODE COMPOSITION COMPRISING A FINELY-DIVIDED, SOLID ELECTRODE INERT TO SAID CARRIER WHICH IS SINTERABLE AT A TEMPERATURE AT WHICH SAID ELECTROLYTE IS SINTERABLE, A SECOND SYNTHETIC, ORGANIC RESIN WHICH DOES NOT LEAVE A RESIDUE WHEN THERMALLY DEGRADDED, AND A SOLVENT FOR SAID SECOND, SYNTHETIC, ORGANIC RESIN; (C) EVAPORATING SAID SOLVENT; (D) THERMALLY DEGRADING SAID FIRST AND SECOND, SYMTHETIC, ORGANIC RESINS; AND (E) IN A SINGLE OPERATION SINTERING SAID ELECTROLYTE AND SAID ELECTRODE.

Self aligning combustor and transition structure for a gas turbine

Abstract: Gas turbine combustion apparatus in which the combustor is anchored at its upstream end and the transition member is anchored at its downstream end, the downstream end of the combustor and the upstream end of the transition member being disposed in mutual engagement and alignment and freely slidable relation during thermal expansion by a clevis support structure and sealed at their engaging portions by a slotted twin layer cuff spring.

Vacuum-type circuit interrupters having heat-dissipating devices associated with the contact structures thereof

Abstract: Vacuum "bottles", or vacuum-type circuit interrupters are provided having heat pipes, or reflux condensers provided in the contacts and contact-stems thereof, to remove the generated heat from the interior of the vacuum-interrupter envelope at the contacts to the external parts of the interrupter, and thereby means of heat-dissipating fins, or other heat-dissipator structures disposed at strategic locations, permit the generated heat to be dissipated to the surrounding atmosphere. By the use of such heat pipes, or reflux condensers, associated with the contact structures of vacuum interrupters, the current ratings of the vacuum interrupters may thereby be increased, and the attained maximum temperatures are considerably reduced, over the situation which would exist if no heat dissipator were employed. The heat pipes, or the reflux condensers may be provided interiorly of one or both of the separable contacts, and the generated heat at the contacts may be transmitted to externally-disposed cooling fins, or other cooling heat-dissipating structures.