Showing papers by "Westinghouse Electric published in 1981"

Estimations on J-integral and tearing modulus T from a single specimen test record

Abstract: This paper presents methods for evaluating the J-integral and the tearing moduli from a single test record. Several different aspects of the problem have been combined in this work. An overview of the conditions for separability of the load into multiplicative functions of displacement and crack length as well as for the existence of it-factors is presented. The consequences of expressing J by a Merkle-Corten type formula are explored in terms of the crack increment, da, the tearing modulus, T, and J itself, including the case of growing cracks. A simple method is suggested to obtain the correct J for crack growth and T from nothing more than the test record itself; the procedure is applied to available experimental data and the results are compared with those obtained by other formulae. Additional physical interpretation is given on the T m a t -versus-T a p p stability criterion and the remaining compliance capacity C C R is defined.

A Branch and Bound Model for Choosing Optimal Substation Locations

Abstract: A distribution planning model is formulated which considers existing and potential substation locations, their capacities and costs, together with the primary feeder network represented by small area demand locations to represent non-uniform loads, and feeder segments having variable distribution costs and limited capacities. A branch and bound search method is described which utilizes a shortest path table to obtain lower bounds and solutions from a transshipment linear programming model for upper bounds. The solution of a small example is presented in detail, and computational results for several larger problems are summarized.

High temperature solid electrolyte fuel cell configurations and interconnections

Abstract: High temperature fuel cell configurations and interconnections are made including annular cells having a solid electrolyte sandwiched between thin film electrodes. The cells are electrically interconnected along an elongated axial outer surface.

Fuel cell generator

Abstract: High temperature solid oxide electrolyte fuel cell generators which allow controlled leakage among plural chambers in a sealed housing. Depleted oxidant and fuel are directly reacted in one chamber to combust remaining fuel and preheat incoming reactants. The cells are preferably electrically arranged in a series-parallel configuration.

Colloidal versus polymer gels and monolithic transformation in glass-forming systems

Abstract: There are three basic types of precursor solution used to form oxides and glasses through gellation: solutions of metallic salts, colloidal sols, and solutions of polymerizing species. Although an intermediate state in all three cases is called a gel, there are fundamental differences in the gelling mechanism and nature of the gel in these systems. In colloidal systems gelling is a result of electrolytic effects which also determine the interparticle distance at the gelling point, thus influencing the capability of the gel to remain monolithic during the transformation to an organic-free state. On the other hand, gelling in polymerized systems occurs as a result of polymerization by chemical reaction. The nature and kinetics of these reactions determine the properties of the gel and resultant inorganic polymer.

Small Crack Behavior and the Prediction of Fatigue Life

Abstract: It is becoming increasingly evident that an understanding of incipient microcracking and growth of small cracks is essential to the development of improved predictions of the fatigue life of structures. Information on the threshold and kinetic properties of small cracks is reviewed and critically discussed. It is shown that the use of conventional fracture mechanics concepts to characterize small cracks results in behavior which differs from that of large cracks—this difference is due to a breakdown of underlying continuum mechanics assumptions. Methods to incorporate small crack behavior in fatigue life predictions are also considered. In these predictions, the importance of separately treating crack initiation and crack growth and of accounting for small crack behavior and plasticity effects (particularly for notched members) is demonstrated.

An Evaluation of Nuclear Power Plant Safety Parameter Display Systems

Abstract: Two proposed safety parameter display systems, of the type to be required in nuclear power plant control rooms, were evaluated using a training simulator and experienced crews undergoing refresher training. A decision analysis approach was used. The discussion addresses the effectiveness of the training situation as an evaluation tool and methodological issues.

Automatic test system utilizing interchangeable test devices

Abstract: An automatic test system controlled by a general purpose digital central processor is disclosed. The central processor accepts test programs in a high level compiler language such as Atlas. The Atlas program is compacted into a simplified language which is utilized to communicate with test devices via a standard IEEE 488 data bus. Each of the test devices includes a programmable interface digital processor which performs any translation that may be necessary in order to permit specific test instruments coupled to the central processor via the interface processor to perform the tests specified by the high level test programs. A switching matrix also communicates with the digital processor to connect the appropriate test device to the unit under test.

Fusion neutron production during deuterium neutral-beam injection into the PLT tokamak

Abstract: Fusion neutron emission of 1.5 × 1014 neutrons s−1 and 2 × 1013 neutrons/pulse has been observed for PLT deuterium discharges with up to 2.5 MW of deuterium neutral-beam injection. The neutron time evolution and magnitude are consistent with theoretical calculations of the fusion reactions caused by energetic injected ions which are confined and slow down classically. The factor-of-two accuracy in the absolute neutron calibration is the major uncertainty in the comparison with theory. Neutron sawtooth oscillations ( 3%) are observed which can also be explained classically.

Event-logging system

Abstract: A solid-state event-logging system records the occurrence of specified events in a removable, solid-state, memory cartridge. Counters continuously count pulses produced by a plurality of electrical energy measuring devices. Sample values of the continuous counts are produced and input to a microprocessor wherein each sample value has the previous sample value subtracted therefrom. The difference is added to an interval sum stored in a random access memory. The interval sums, together with real time information produced by a clock, are input to the memory cartridge according to a predetermined format. The clock is maintained in synchronization with the frequency of the line voltage by the microprocessor.

Computer Image Generation for Flight Simulation

Abstract: Visual simulation seems to imply image realism-though visual simulation systems can produce realistic images, their main goal Is training effectiveness

Variable area fuel cell cooling

Abstract: A cooling module (42) for a fuel cell arrangement (10) having cooling fluid flow passages (44) which vary in surface area from the inlet to the outlet of the passages. A smaller surface area is provided at the passage inlet, which increases toward the passage outlet, so as to provide more uniform cooling of the entire fuel cell. The cooling passages (44), can also be spaced from one another in an uneven fashion. The ability to provide more uniform cell temperature and consequently to increase the cell temperature for a given maximum level means a reduction in the effect of carbon monoxide poisoning. Also, a reduction in air flow reduces the power ! required to circulate cooling air stream.

Electro-optical system for correlating and integrating image data from frame-to-frame

Abstract: An electro-optical system which integrates the image pattern information, extracted from a plurality of image frames and identified as belonging to a common candidate object, to form a composite image pattern of the candidate object which may be accurately classified with respect to a reference object image pattern is disclosed. More specifically, the formed composite image pattern of the candidate object is correlated with each image pattern of a set of reference object image patterns to generate a corresponding set of correlation values. Preferably, the largest of the correlation values is selected for a comparison with a threshold correlation value. In the event the generated correlation value exceeds the threshold correlation value, the candidate object represented by the composite image pattern is classified as the referenced object corresponding to the selected correlation value. Another aspect of the electro-optical system permits the threshold correlation value to be adaptively selected in accordance with the number of frames integrated to form the composite image pattern under consideration for classification. In addition, a final classification of the candidate object may include the smoothing of a plurality of classification decisions generated throughout the integration sequence during which a number of composite image patterns are formed.

Apparatus and method for tape bonding and testing of integrated circuit chips

Abstract: A metallic lead frame strip, method of manufacturing same, a test tape, a method of testing together with the art work for same is disclosed. The method of manufacturing includes a method for producing art work that provides for accuracy in etching both sides of the lead frame strip simultaneously and permits a highly accurate positioning of the bonding bumps of at least one integral bonding bump for each lead and also discloses leads having a plurality of bonding bumps for connecting electrically common portions of a chip to be tested. Also, the use of registration aids are disclosed which allow lead bumps to be registered to chip pads even though the bumps cannot be seen in the alignment step. The testing of the chip also includes a method and double-layer test strip that may be used repeatedly for testing successively larger chips having an increasing number of individual leads.

Recent developments in the technology of sulphur dioxide depolarized electrolysis

Abstract: The use of sulphur dioxide as an anode depolarizer in the electrolytic production of hydrogen can considerably reduce the electrical energy input to the electrolyzer. The present work deals with developments in the technology of SO2-depolarized electrolysis. Recent achievements in electrode fabrication techniques and optimization of cell configuration have resulted in substantial improvements in both cell potential and performance stability. While operating in 50 wt% sulphuric acid at 50° C and 1 atm, the measured cell potentials at 200 and 400mA cm−2 were ≈ 0.77 and 1.05V (including ohmic losses), respectively. A cell endurance test, performed at a constant current density of 100mA cm−2, indicated that a stabilized cell potential of ≈ 675 mV was achieved after 80 hours of continuous operation. The resulting gas from the test cell contained 98.7 vol% hydrogen. The effect of acid concentration in the range 10–60 wt% on the performance characteristics of an SO2-depolarized electrolyzer was also investigated. Experimental results revealed that the optimum acid concentration for operating SO2-depolarized electrolyzers is approximately 30 wt%. The observed cell potential was only 0.71 V at 200mA cm−2.

Flow-Induced Vibration and Wear of Steam Generator Tubes

Abstract: Potential tube fretting wear and fretting fatigue caused by flow-induced vibration are addressed in the design of nuclear steam generators. Flow-induced interactions of the tubes with the tube supp...

Review of high-voltage gas breakdown and insulators in compressed gas

Abstract: In the past ten years there have been significant advances in the theoretical and experimental analysis of high-voltage gas breakdown and surface flashover of insulators in compressed gases. This has probably been fostered by the recent growth in the design and application of gas-insulated high-voltage equipment. The review describes the characteristics of compressed-gas breakdown, including the effects of failure of Paschen's law; conditioning; electrode area; material and surface; breakdown-voltage distribution; particle contamination; voltage waveform; temperature; and gas mixtures. The insulator-flashover characteristics are then described, including the effects of insulator-electrode interface; insulator material; insulator shape; voltage waveform; charge generation; particle contamination; surface contamination; conditioning; flashover distribution; and dependence on type of gas. The various mechanisms proposed for gas breakdown and insulator flashover are reviewed and discussed in relation to the experimental characteristics. Future theoretical and experimental work is suggested to clarify the gas-breakdown and insulator-flashover mechanisms, and which would also help bring about the design of improved high-voltage gas-insulated systems.

Metal acetylacetonates as latent accelerators for anhydridehyphen;cured epoxy resins

Abstract: Twenty-two metal acetylacetonate compounds have been evaluated as possible latent accelerators for epoxy-anhydride solventless resins. Experimental data have revealed that titanium (IV) oxyacetylacetonate, chromium (III), zirconium (IV), cobalt (III), and cobalt (II) acetylacetonates are particularly effective with anhydride cured epoxy resins. When added to the resin at a level of 0.05–0.10% (w/w), they provide very fast gel times at 150–175°C combined with very good storage stabilities (> six months) at room temperature. The power factor values of cured resin samples, containing these preferred metal acetylacetonates, have been found to be between 2.0 and 2.5% at 150°C and 60 Hz. Correlation between the catalytic effectiveness of these metal acetylacetonates, as latent accelerators for epoxy-anhydride resins, and their thermal stabilities suggest that decomposition products may be the active species responsible for initiating polymerization in epoxyanhydride resin systems.

Method and apparatus for the automatic diagnosis of system malfunctions

Abstract: Diagnostic apparatus for monitoring a system subject to malfunctions. Estimates are obtained relating normal system operation to operating variables. Estimates are additionally obtained relating specific malfunctions to specific variables. The variables are combined in accordance with predetermined functions to get an indication of a particular malfunction. This indication is modified by a factor related to the normal operation of the system to yield a probability of the occurrence of the malfunction, and which probability is limited to a value less than 100%.

Distribution network communication system with flexible message routes

Abstract: Each customer location is equipped with a remote terminal which contains a role code identifying the remote terminal as an end device and a plurality of address codes. A plurality of signal repeaters are each connected with certain of the remote terminals through a distribution network. Each signal repeater contains stored route and role codes as well as a unique address code allowing each signal repeater to be additionally addressed as an end device. A central station produces an outgoing communication signal intended for at least one end device. A communication link couples the central station to the power distribution network. The communication signal includes a route code identifying a signal path to the end device, a role code identifying the first device in the identified route, an address code and a message code. Upon receipt of the communication signal by a signal repeater which is not the intended end device, the received route and role codes are compared to the stored route and role codes. If there is a match, the signal repeater removes its role code from the communication signal, inserts the role code of the next device in the identified route and retransmits the signal. The signal is continually modified and retransmitted until the message code is received by the intended end device.

Multi-processor automatic test system

Abstract: A test system utilizing a plurality of programmable test instruments each capable of executing portions of a test program with the test program being written in a compiler language such as ATLAS, for example, is disclosed. Programs specifying the tests to be performed are written in a compiler language such as ATLAS and transferred to a central control processor utilizing standard peripheral equipment. The central control processor communicates with a plurality of test instruments utilizing a series of data busses. In executing the test program, the control processor first segments the program into a series of individual tests to be performed. The test instruments are interrogated to determine which of the test instruments is currently capable of executing a specific sequence of the test program. Once an instrument has been identified which can execute the program segment, the control process transfers that segment to the instrument capable of executing the test. After a test has been executed, the programmable test instrument executing the test transfers the result of the test back to the central control processor for analysis. In addition to performing the basic test, each of the instruments also has access to the switching matrix so that the required interconnects between the system being tested and the test instruments can be made under the control of the test instrument itself. Functionally, each of the test instruments accepts segments of the overall test program in a compiler language and performs all the functions necessary to execute that segment of the program and transfer the test results to the central processor. The function of the central processor is to control the system, allocate portions of the program to each of the test instruments and analyze the final test result. Alternate embodiments provide means permitting any one of the programmable test instruments to assume control of the entire system.

Robotic manipulator structure

Abstract: A robotic manipulator structure including a base supporting first and second independently operable drive motors 16 and 18, a first swinging arm rotatably supported by the base and driven from the first drive, a second swinging arm 42 supported for rotation at the end of the first arm for rotation through a plane translationally displaced from the plane through which the first arm rotates, and a mechanism for coupling the rotation of the second drive motor 18 through the hollow shaft 50 concentrically located and rotatable within the hollow shaft 38, and through a sprocket and chain arrangement in the hollow 58 of the first arm to independently effect the rotation of the second arm 42

Photodetectors for acousto-optic signal processors

Abstract: A description of devices, architecture, and performance criteria is presented for solid-state CCD and photodiode sensors useful in acousto-optic processing systems. Special attention is given to sensors used in both bulk and integrated optical acousto-optic instantaneous Fourier transform systems. The device physics of silicon photodetectors is presented in detail including discussion and analysis of quantum efficiency, responsivity, ctosstalk, charge handling capacity, data rate, optical to electrical transfer function, noise sources, dynamic range, and sensitivity. A description of new technologies, such as VHSIC and GaAs IC's which are applicable to sensor technology for AO signal processing systems is also presented.

Hot gas particulate removal

Abstract: Filtration system configurations particularly useful for cleaning high temperature raw gas containing fine particulates such as that discharged from coal gasification and fluidized bed combustion processes. Thin filter elements, having elongated clean channels on one side of a gas permeable ceramic membrane and shorter dirty channels on the other side, extend radially outward from a central duct. Raw gas flows about and through the filter elements, and clean gas which permeates the membrane enters the duct. The elements are cleaned by a back pulse of clean air, spitting the particulates to the bottom of the containing vessel and through an outlet. A high density filter packing within a containing pressure vessel is achieved by nesting a plurality of the duct and filter element modules, or through other orientations and filter element configurations.

Dynamic Stabilizer Verification Tests at the San Juan Station

Abstract: The first Torsional Dynamic Stabilizers were installed at the San Juan generating station to control subsynchronous oscillations between the turbine-generator units and the series capacitor compensated transmission system. A description of these devices and their application at this plant is the subject of this paper. A field test program which included control of self-excited torsional oscillations is described. Test results verify that the Dynamic Stabilizers do control San Juan subsynchronous oscillations and allow unrestricted use of the compensation.

High-purity semi-insulating GaAs material for monolithic microwave integrated circuits

Abstract: Liquid-Encapsulated Czochralski (LEC) growth of large-diameter bulk GaAs crystals from pyrolytic boron nitride (PBN) crucibles has been shown to yield high crystal purity, stable high resistivities, and predictable direct ion-implantation characteristics. Undoped (≲low 1014cm-3chromium) and lightly Cr-doped (low 1015cm-3range) -GaAs crystals, synthesized and pulled from PBN crucibles contain residual shallow donor impurities typically in the mid 1014cm-3, exhibit bulk resistivities above 107Ω . cm, and maintain the high sheet resistances required for IC fabrication (>106Ω/□) after implantation anneal. Direct29Si channel implants exhibit uniform (± 5 percent) and predictable LSS profiles, high donor activation (75 percent), and 4800- to 5000-cm2/V . s mobility at the (1 to 1.5) × 1017cm-3peak doping utilized for power FET's. It has also been established that LEC crystals can provide the large-area, round