Showing papers by "Westinghouse Electric published in 1987"

Classification of dolomite rock textures

Abstract: Dolomite rock textures can be classified according to crystal size distribution and crystal boundary shape. The classification scheme presented here is largely descriptive but carries genetic implications because size distribution is controlled by both nucleation and growth kinetics, and crystal boundary shape is controlled by growth kinetics. Size distributions are classified as unimodal or polymodal. Crystal boundary shapes are classified as planar or nonplanar. If the evidence permits, a complete classification includes a description of recognizable allochems, matrix, and void filling. Allochems and preexisting cements may be unreplaced, partially replaced, replaced mimically, or replaced nonmimically. Allochems may be dissolved, leaving molds. Matrix can be unreplace, partially replaced, or replaced by a unimodal or polymodal size dolomite. Unimodal size distributions generally indicated a single nucleation event on a unimodal substrate. Polymodal sizes can be formed by multiple nucleation events on a unimodal or polymodal substrate or differential nucleation on an originally polymodal substrate. Planar crystal boundaries develop when crystals undergo faceted growth, and nonplanar boundaries develop when crystals undergo nonfaceted growth. Nonplanar boundaries are characteristic of growth at elevated temperature (> 50°C) and/or high supersaturation. Both planar and nonplanar dolomite can form as a cement, replacement of CaCO3, or neomorphism of a precursor dolomite.

Evidence for weak link and anisotropy limitations on the transport critical current in bulk polycrystalline Y1Ba2Cu3Ox

Abstract: Measurements of the transport critical‐current density (Jc), magnetization Jc, and magnetoresistance in a number of bulk sintered samples of Y1Ba2Cu3Ox from several different laboratories indicate that the transport Jc is limited by weak‐link regions between high Jc regions. The weak‐link Jc has a Josephson character, decreasing by two orders of magnitude as the magnetic field is increased from 0.1 to 10 mT at 77 K. An examination of the grain‐boundary region in Y1Ba2Cu3Ox shows no observable impurities or second phases to the scale of the [001] lattice planes (∼12 A). The effect of intrinsic conduction anisotropy is discussed. A current‐transfer model is proposed in which weak conduction along the c axis plays a role in limiting Jc at grain boundaries. Orienting the grains in the powder state during processing may result in enhanced transport Jc in bulk conductors.

Human interaction with an “intelligent machine

Abstract: In this paper we report the results of a study of technicians diagnosing faults in electro-mechanical equipment with the aid of an expert system. Technicians varying in level of experience and interactive style (active or passive) diagnosed faults varying in level of difficulty. The results indicate that the standard approach to expert system design, in which the user is assigned the role of data gatherer for the machine, is inadequate. Problem solving was marked by novel situations outside the machine's conpetence, special conditions, underspecified instructions, and error recovery, all of which required substantial knowledge and active participation on the part of technicians. We argue that the design of intelligent systems should be based on the notion of a joint cognitive system architecture: computational technology should be used to aid the user in the process of solving his problem. The human's role is to achieve total system performance as a manager of knowledge resources that can vary in kind and amount of “intelligence” or power.

Verification of computer software

Abstract: A computer program is verified, unit by unit, by automatically instrumentating the code and generating a test driver program which executes all branches of an instrumented code unit. The code is instrumented by operating processors to standardize the code format and to insert executable tracer statements into each block of reformatted code between control statements. A pseudocode having only control statements and tables identifying valid linkages between blocks of code are generated by another processor for use by a verifier in selecting values of input variables and expected outputs for test cases which execute each block of code in the selected unit. Another processor generates the test driver program from the test cases and a software test specification identifying the test cases and expected results. The test driver program and instrumented code unit are compiled and linked to repeatively execute the instrumented code unit to implement all the test cases. Results of the test cases are printed out indicating the sequence of block linkages generated by each test case, the expected output values and the actual output values.

Mapping cognitive demands in complex problem-solving worlds

Abstract: Tool builders have focused, not improperly, on tool building--how to build better performing machine problem-solvers, where the implicit model is a human expert solving a problem in isolation. A critical task then for the designer working in this paradigm is to collect human knowledge for computerization in the stand alone machine problem-solver. But tool use involves more. Building systems that are "good" problem-solvers in isolation does not guarantee high performance in actual work contexts where the performance of the joint person-machine system is the relevant criterion. The key to the effective application of computational technology is to conceive, model, design, and evaluate the joint human-machine cognitive system (Hollnagel & Woods, 1983). Like Gestalt principles in perception, a decision system is not merely the sum of its parts, human and machine. The configuration or organization of the human and machine components is a critical determinant of the performance of the system as a whole (e.g. Sorkin & Woods, 1985). The joint cognitive system paradigm (Woods, 1986; Woods, Roth & Bennett, in press) demands a problemdriven, rather than technology-driven, approach where the requirements and bottlenecks in cognitive task performance drive the development of tools to support the human problem-solver. In this paper we describe an approach to understand the cognitive activities performed by joint human-machine cognitive systems. The real impediment to effective knowledge acquisition is the lack of an adequate language to describe cognitive activities in particular domains--what are the cognitive implications of some application's task demands and of the aids and interfaces available to the people in the system; how do people behave/perform in the cognitive situations defined by these demands and tools. Because this independent cognitive description has been missing, an uneasy mixture of other types of description of a complex situation has been substituted---descriptions in terms of the application itself, of the implementation technology of the interfaces/aids, of the user's physical activities or user psychohaetrics. We describe one approach to provide an independent cognitive description of complex situations that can be used to understand the sources of both good and poor performance, i.e. the cognitive problems to be solved or challenges to be met.

Role of matrix‐particle interface adhesion on fracture toughness of dual phase epoxy‐polyethersulfone blend

Abstract: Compatibility or miscibility of a polyethersulfone (ICI: Victrex 100P) and a tetrafunctional epoxy (Ciba-Geigy: MY-720), cured with an aromatic anhydride, has been studied using scanning electron microscopy, x-ray microanalysis, and dynamic mechanical spectroscopy. Fracture toughness of epoxy and a blend of epoxy and polyethersulfone has been measured using three point bend tests (ASTM: E-399-81). Fracture surfaces were examined by x-ray microanalysis for detecting concentration of sulfur, present in polyethersulfone, in the matrix and precipitated phase. The influence of the morphology of the epoxy/polyethersulfone blend on its fracture toughness and toughening mechanism has been studied. Fracture toughness values of unmodified and modified cured epoxy resin were evaluated as a function of test temperature.

Effect of Sol‐Gel Mixing on Mullite Microstructure and Phase Equilibria in the α‐Al2O3‐SiO2 System

Abstract: Starting powders containing 72 wt% Al/sub 2/O/sub 3/ and 28 wt% SiO/sub 2/ were prepared by sol-gel methods classified as colloidal and polymeric. Compacts fired at 1700/sup 0/C showed significant differences in microstructure. The specimens formed with the colloidal powder had mullite grains of prismatic shape and liquid phase; with polymeric powder, mullite grains were granular with no liquid phase present. It is shown that the mullite grains in the first case are higher in Al/sub 2/O/sub 3/ content, resulting in an excess of SiO/sub 2/ which is the base for the liquid phase. In the second case, the mullite grains have the same Al/sub 2/O/sub 3/ content as the starting powders. The presence of a liquid phase in the first case is considered to be metastable, resulting from the nature of the starting materials and processing conditions employed.

Energy beam casting of metal articles

Abstract: Near net shape metal articles are cast from powder feedstock using a focused high energy beam which melts successive layers of powder as it repetitively traces the shape of the article over a substrate without the necessity for refocusing. Powder is fed into a cavity in which the article is formed at a rate to maintain a depth which provides lateral support for, and therefore forms a mold for, a thick layer of powder which is melted by the energy beam to add each layer to the article. The high energy laser or electron beam has a power density sufficient to penetrate the melted layer of powder and melt the surface of the underlying substrate or layer just enough to provide a good metallurgical bond for the layer being added. A copper fixture which supports the substrate while the article is being formed, serves as a heat sink and forms the cavity which confines the powder to the vicinity of the article being formed. Various shapes can be cast through selected programming of the repetitive pattern of relative motion between the energy beam and the substrate.

Product information network system

Abstract: A manufacturing data creation and distribution system comprises a computer with a graphics-capable display screen. The computer is capable of processing programmable instructions and creating data, and of generating graphic images on the display screen. A video camera is connected to the computer, and the computer includes hardware which can digitize the images transmitted by the video camera into a computer-readable form and display the digitized camera images on the display screen. A plurality of microprocessor-controlled workstations are networked to a microprocessor-controlled networking and file server, which can selectively retrieve data and transmit such data to the workstations for display. Also included within the computer is the capability to selectively manipulate the image-data received from the video camera to generate a manufacturing aid applicable to a product to be produced.

Fuel cell generator containing self-supporting high gas flow solid oxide electrolyte fuel cells

Abstract: Axially elongated, electrochemical cell assembly containing a plurality of cell elements each made up of an electronically conductive, porous, inner electrode (47), an annular, solid electrolyte (45) contacting and surrounding said first electrode, and an annular, electronically conductive, porous, outer electrode (49) contacting and surrounding said electrolyte, with annular, electronically conductive, interconnection members (51) disposed between and bonded to cell elements, where the inner electrodes of the cell elements are electronically connected through the interconnection member, and the outer electrodes of the cell elements are physically and electronically segmented from each other; where a plurality of such cell assemblies can be connected by a sleeving means and placed in the generating chamber of an electrochemical cell generator, which also has an associated dual gaseous reactant input, at least one combustion product chamber, and a combustion product gas exhaust.

Passively cooled catalytic combustor for a stationary combustion turbine

Abstract: A catalytic combustor unit for a stationary combustion turbine includes a substrate composed of a plurality of intersecting walls defining a series of generally parallel passages aligned in rows and columns, open at their opposite ends and exposed to a heated flow of fuel and air mixture therethrough. The walls have sections which border and define the respective passages. Each wall section is in common with two adjacent passages and has a pair of oppositely-facing surface regions, one of which is exposed to one of the two adjacent passages and the other exposed to the other of the two adjacent passages. A catalyst coating is applied on selected ones of the wall surface regions exposed to certain ones of the passages, whereas selected others of the wall surfaces exposed to certain others of the passages are free of the catalyst coating. The substrate is thus provided with an arrangement of catalyzed passages in which the mixture is catalytically reacted and non-catalyzed passages in which the mixture is substantially not reacted but instead provides passive cooling of the substrate.

Low NOx rich-lean combustor especially useful in gas turbines

Abstract: A combustor capable of reducing the noxious emissions such as fuel bound and thermal nitrogen oxide products, during combustion of high nitrogen bearing and high aromatic content fuels is disclosed. The combustor includes a plurality of substantially concentric pipes defining annular passages with annular divergent nozzles. The divergent nozzles may be formed by rings having a venturi shaped axial section to facilitate fast mixing of axially supplied air between adjacent annular passages. The longitudinal spacing between at least two adjacent nozzles defines first and second divergent cavities. A fuel rich torodial vortex is formed in proximity to a central fuel jet in the first cavity and advantageously converts fuel bound nitrogen to N2. A fuel lean torodial vortex formed in the second cavity mixes hot combustion products with additional gaseous reactant to complete the combustion while avoiding locally high temperatures, and thus thermal NOx formation. A ring of jet nozzles radially injects relatively small amounts of high pressure gaseous reactant or steam to form a throat to separate and stabilize the vortices. Alternatively, the pipe extending between the two cavities can include a convergent and divergent portion forming the throat between the cavities for separating and reinforcing the toroidal vortices. Guide vanes may be positioned in the annular passages to swirl the gaseous reactant entering the cavities to assist in the formation of the toroidal vortices.

Integral cooling garment for protection against heat stress

Abstract: An integral cooling garment for protection against heat stress characterized by a pair of separate linings stitched together to form tube-receiving chambers which microporous tubes are detachably connectable to a source of liquid carbon dioxide which converts to a solid phase and then gradually sublimates to carbon dioxide gas that is released into the chambers for cooling a wearer of the article of clothing, and the article being untethered to the source of liquid carbon dioxide when worn.

Passive safety system for a pressurized water nuclear reactor

Abstract: A passive safety system for a nuclear reactor is comprised of a first subsystem for circulating water solely by natural convection from a first branch to a second branch of a reactor coolant circuit with the circumvention of a steam generator for removing decay heat from the reactor coolant circuit at any pressure. There is also provided a second subsystem for introducing stored cold water solely by gravity into the reactor vessel for making up for lost water in the reactor coolant circuit at any pressure. The passive safety system further has a third subsystem for introducing stored cold water solely by gravity into the reactor vessel when the pressure with the reactor coolant circuit is reduced at least approximately to the same pressure as in the containment, for flooding the containment to a height above the first and second branches of the reactor coolant circuit.

Multi-layer single substrate microwave transmit/receive module

Abstract: A microwave transmit/receive module comprises a single multi-layer substrate having at least two opposed mounting surfaces. The substrate including a plurality of integrated dielectric layers, electrical conductors and thermal conductors selectively interconnected between the layers of the substrate. A microwave signal processing means is mounted on at least one of the mounting surfaces of the substrate for processing microwave radar signals. A control signal processing means is mounted on at least one of the mounting surfaces of the substrate for providing control signals for the microwave signal processing means via selected electrical conductors. A power conditioning means is mounted on at least one of the mounting surfaces of the substrate for providing power to the microwave signal processing means and the control signal processing means via selected electrical conductors. A heat sink interface means coupled to the thermal conductors is mounted on at least one of the mounting surfaces of the substrate in thermal proximity selected portions of the microwave signal processing means, the power conditioning means and the control signal processing means for conducting thermal energy away therefrom via selected thermal conductors. An optical interface interface as well as an integrated coaxial cable carrying power, control and microwave signals for the module.

Properties and microstructure of thin LiNbO3 films prepared by a sol-gel process

Abstract: Thin LiNbO3 films were prepared from polymerized sol-gel precursor solutions having various concentrations and water:alkoxide ratios in an effort to investigate the effects of these and other processing variables on the resultant film properties and microstructure. Films deposted on silicon substrates were mostly amorphous when pyrolyzed at 435°C for 30 min. Randomly oriented polycrystalline films having distinctive microstnietures were produced using longer heating times or higher temperatures. All of the films exhibited low refractive indices due to porosity, which was attributed to the low level of hydrolysis water required to produce stable polymeric precursor solutions. When single-crystal LiNbO4 was used as the substrate, epitaxial growth of the film resulted. This ideal case establishes the feasibility of producing epitaxial films via sol-gel processing. All films were characterized by transmission electron microscopy (TEM) and thin-film x-ray diffraction patterns.

Automated visual assessment system with steady state visual evoked potential simulator and product detector

Abstract: An automated visual testing system is disclosed which presents an alternating steady state visual stimulus to a patient through an optical system that modifies the stimulus image. As the image changes, the patient produces evoked potentials that change. The evoked potentials are detected by a product detector which produces the amplitude of the evoked potentials. The amplitude is monitored through an analog to digital converter by a supervisor computer. The supervisor computer produces patient response curves from which it diagnoses visual system malfunction and/or prescribes correction. A control processor controls a stimulus generator to produce the image and an optical system, that includes polarizers, an astigmatism test slit or a cylindrical lense, a zoom lense system and a variable focal length test lense, transmits the image to the patient. The steady state visual potential stimulus generator is a device by which a rapidly complementing or flashing pattern can be presented to the patient. The generator allows the contrast of the image to be varied without varying luminance and allows operation in a true bicolor and multicolor mode. The product detector detects the level of the steady state evoked potential signals even in the presence of substantial background noise and extraneous electroencephalographic signals. These detectors can be used to monitor the evoked potential produced by visual, all or somatic steady state stimuli. The components described above can be used to produce a system that can determine to which of several different displays an observer is paying attention by providing images that blink at different frequencies and product detectors for each of the stimulus frequencies. The product detector producing the highest output indicates the display upon which the observer is focused.

IGSCC Behavior of Alloy 600 Steam Generator Tubing in Water or Steam Tests Above 360 C

Abstract: Laboratory testing to produce intergranular stress corrosion cracking (IGSCC) of Alloy 600 steam generator tubing in primary water environments can require lengthy exposure times, even at ...

Machine assisted execution of process operating procedures

Abstract: A computer based system aids an operator in proceeding step-by-step through procedures for a complex process facility. At each step, monitored plant parameter values are used to evaluate relevant plant status and recommend action to be taken. The status and recommended action are presented to the operator on a display device together with prompts for generating appropriate responses. The step logic is carried out repetitively to provide the operator with feedback and to verify operator actions. The complete display picture including operator responses, and other plant conditions monitored in parallel with the current step, is logged for later review. An online review feature permits review of plant conditions and operator actions while the operator continues to execute the procedure. High-level textual statements of all steps of a current procedure can be reviewed and prior steps can be executed or re-executed.

Seawater power cell

Abstract: Disclosed is a battery having an anode selected from the group consisting of magnesium, zinc, and mixtures and alloys thereof, an oxygen electrode as the cathode, and means for maintaining the anode and the cathode in an electricity-generating relationship when the battery is placed in salt water. Also disclosed is a method of producing electricity by positioning the anode and cathode in a saline electrolyte whereby the reaction M+20H.sup.- →M(OH).sub.2 +2e.sup.- occurs at the anode and the reaction O.sub.2 +2H.sub.2 O+4e.sup.- →20H.sup.31 occurs at the anode, where M is magnesium, zinc, aluminum, or mixtures or alloys thereof.

Effect of compositional variation and annealing in oxygen on superconducting properties of Y 1 Ba 2 Cu 3 O 8-y

Abstract: Changes in the ratios of cations by \ensuremath{\sim}10% off the ${\mathrm{Y}}_{1}$${\mathrm{Ba}}_{2}$${\mathrm{Cu}}_{3}$${\mathrm{O}}_{8\mathrm{\ensuremath{-}}\mathrm{y}}$ composition demonstrated that a range of solid solutions exists in this material. The critical temperature within this range is strongly composition dependent and falls off from above 90 K to \ensuremath{\sim}70 K. Annealing stoichiometric samples in 1 bar of oxygen at 700 \ifmmode^\circ\else\textdegree\fi{}C for 36 and 108 h resulted in narrowing of the magnetic susceptibility transition and significant increases in the critical current density ${J}_{c}$, p-type effective carrier concentration ${n}^{\mathrm{*}}$, and upper critical field, ${H}_{c2}$. After annealing, ${J}_{c}$ between 5 and 60 kOe was (3--1.5)\ifmmode\times\else\texttimes\fi{}${10}^{4}$ A/${\mathrm{cm}}^{2}$ at 4.2 K and (2--0.5)\ifmmode\times\else\texttimes\fi{}${10}^{2}$ A/${\mathrm{cm}}^{2}$ at 77 K. The value of ${n}^{\mathrm{*}}$ after annealing was 4.2\ifmmode\times\else\texttimes\fi{}${10}^{21}$ ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}3}$. An extrapolated value of ${H}_{c2}$(T=0)=1.2 MOe was obtained from \ensuremath{\Vert}${\mathrm{dH}}_{c2}$/dT\ensuremath{\Vert}=19 kOe/K. A set of microscopic superconducting parameters was derived from results of resistive measurements made on a single, annealed specimen.

Generator configuration for solid oxide fuel cells

Abstract: Disclosed are improvements in a solid oxide fuel cell generator 1 having a multiplicity of electrically connected solid oxide fuel cells 2, where a fuel gas is passed over one side of said cells and an oxygen-containing gas is passed over the other side of said cells resulting in the generation of heat and electricity. The improvements comprise arranging the cells in the configuration of a circle, a spiral, or folded rows within a cylindrical generator, and modifying the flow rate, oxygen concentration, and/or temperature of the oxygen-containing gases that flow to those cells that are at the periphery of the generator relative to those cells that are at the center of the generator. In these ways, a more uniform temperature is obtained throughout the generator.

Dehumidification: on the correlation of wet and dry transport processes in plate finned-tube heat exchangers

Abstract: The transverse velocity of the condensing phase during dehumidification is analogous to the transverse velocity at the wall when exercising boundary layer control by fluid extraction through a permeable wall. Wet and dry pressure drop and heat transfer rates are analyzed for correlation using boundary layer suction theory. Data are presented for flat-plate finned-tube heat exchangers during air heating and dehumidification operations and the data show a significant effect of transverse velocity correlated by the boundary layer suction formulation. The condensate film is considered isothermal in this analysis and the results indicate that an improved modeling of the condensate film is required. The authors find that the transverse velocity of the condensing phase has an important effect on transport phenomena during dehumidification and that the validity of the Chilton-Colburn heat and mass transfer analogy in describing dehumidification is supported by these results. It should be noted that the dry data form the beginning of a plate fin heat exchanger data base. The present data show the effect of tube diameter and, independently, fin density variation on the Colburn and friction factors with all other geometric parameters held invariant.

Method for laser beam welding metal matrix composite components

Abstract: A substantially homogeneous metal matrix composite conduction weld between first and second metal matrix composite components is formed by placing the components into abutting position, with a major portion thereof spaced from each other, and directing a laser beam through the spacing onto the intersection and oscillating the beam across the intersection to form a shallow pool of metal matrix composite while feeding a metal matrix composite filler wire into the pool. The laser beam and filler wire are moved along the intersection such that solidification of the molten pool containing the filler wire metal matrix composite is effected, to form the weld line, without separation of the metal matrix composite into separate phases. The filler wire may be preheated and pressure may be applied, either to one or both components in a direction transverse the plane of the intersection or to the weld line in the direction of the plane of the intersection.

Apparatus for the measurement and/or regulation of a braking force and/or of a braking torque

Abstract: An apparatus which measures and regulates the braking torque of a brake unit in long-term operational use. The brake unit includes both a brakable element and the braking device. An output signal from at least one temperature-dependent measuring element, located on or in one of the brakable elements and the braking device, is supplied to an evaluation apparatus. The evaluation apparatus determines, from the current value of the output signal of the temperature-measuring element, a present braking torque, and adjusts such torque when desirable.

Elongated solid electrolyte cell configurations and flexible connections therefor

Abstract: A flexible, high temperature, solid oxide electrolyte electrochemical cell stack configuration is made, comprising a plurality of flattened, elongated, connected cell combinations 1, each cell combination containing an interior electrode 2 having a top surface and a plurality of interior gas feed conduits 3, through its axial length, electrolyte 5 contacting the interior electrode and exterior electrode 8 contacting electrolyte, where a major portion of the air electrode top surface 7 is covered by interconnection material 6, and where each cell has at least one axially elongated, electronically conductive, flexible, porous, metal fiber felt material 9 in electronic connection with the air electrode 2 through contact with a major portion of the interconnection material 6, the metal fiber felt being effective as a shock absorbent body between the cells.

Sputter deposition of YBa2Cu3O7−y thin films

Abstract: Thin films of YBa2Cu3O7−y were prepared by magnetron sputtering. The films were characterized by x‐ray diffraction, in situ x‐ray photoelectron spectroscopy to determine the as‐deposited oxygen content for various substrate temperatures, and scanning electron microscopy to analyze the microstructure. The orthorhombic phase was observed after an ex situ 700 °C anneal. We have obtained films which were completely superconducting at 82 K with 6 K transition widths.

Current Readout Of Infrared Detectors

Abstract: A buffered direct-injection (BDI) current readout for infrared detectors is described and analyzed. It is compared with the common direct-injection (DI) circuit with respect to injection efficiency, noise, and tolerance of low RoA product photovoltaic detectors. Power requirements and threshold control are also discussed. Throughout the analysis it is clear that much advantage is gained at relatively little cost by the use of a BDI structure for an integrated circuit focal plane.