Showing papers by "General Electric published in 1970"

Transmission Network Estimation Using Linear Programming

Abstract: One aspect of long-range planning of electric power systems involves the exploration of various designs for the bulk power transmission network. The use of linear programming for network analysis to determine where capacity shortages exist and, most importantly, where to add new circuits to relieve the shortages is presented. The new method of network estimation produces a feasible transmission network with near-minimum circuit miles using as input any existing network plus a load and generation schedule. An example is used to present the two steps of the method: 1) linear flow estimation and 2) new circuit selection. The method has become a fundamental part of computer programs for transmission network synthesis.

Infrared Absorption in Some II-VI Compounds Doped with Cr

Abstract: The optical absorption spectra of substitutional ${\mathrm{Cr}}^{2+}$ ($3{d}^{4}$) in single crystals of ZnS (cubic and mixed cubic-and-hexagonal), ZnSe, ZnTe, CdS, and CdTe have been measured for Cr concentrations of ${10}^{18}$-${10}^{20}$ ${\mathrm{cm}}^{\ensuremath{-}3}$ and at 2, 15, and 300\ifmmode^\circ\else\textdegree\fi{}K in the wave-number range $5\ensuremath{\le}\overline{\ensuremath{ u}}\ensuremath{\le}30000$ ${\mathrm{cm}}^{\ensuremath{-}1}$. The room-temperature spectrum in the range $500\ensuremath{\le}\overline{\ensuremath{ u}}\ensuremath{\le}30000$ ${\mathrm{cm}}^{\ensuremath{-}1}$ is dominated by a broad absorption band at 5500 ${\mathrm{cm}}^{\ensuremath{-}1}$ arising from the $^{5}T_{2}\ensuremath{\rightarrow}^{5}E$ transition. These two levels originate from the crystal-field splitting of the $^{5}D$ free-ion ground state. At helium temperatures distinct lines appear on the low-energy side of the $^{5}T_{2}\ensuremath{\rightarrow}^{5}E_{2}$ absorption band in all samples except for CdTe. These lines are associated with zero-phonon transitions and phonon-assisted transitions. As the temperature is increased, the relative intensities of some of the lines change due to the thermal population of low-lying levels belonging to the orbital ${T}_{2}$ state. In the case of ZnSe these levels have been studied in the far infrared in the range $5\ensuremath{\le}\overline{\ensuremath{ u}}\ensuremath{\le}200$ ${\mathrm{cm}}^{\ensuremath{-}1}$, both with and without a magnetic field. An interpretation of the results is made based on crystal-field theory with a strong, static, Jahn-Teller distortion of $E$ symmetry in the $^{5}T_{2}$ orbital ground state. There is little or no Jahn-Teller effect in the $^{5}E$ orbital excited state. The optical transitions exhibit a strong coupling to $E$-mode phonons of average energy \ensuremath{\sim}70 ${\mathrm{cm}}^{\ensuremath{-}1}$.

Properties of deterministic top-down grammars

Abstract: The class of context-free grammars that can be deterministically parsed in a top down manner with a fixed amount of look-ahead is investigated. These grammars, called LL(k) grammars where k is the amount of look-ahead are defined and a procedure is given for determining if a context-free grammar is LL(k) for a given value of k . A procedure is given for eliminating the e-rules from an LL(k) grammar at the cost of increasing k by 1. There exist cases in which this increase is inevitable. A procedure is given for obtaining a deterministic push-down machine to recognize a given LL(k) grammar and it is shown that the equivalence problem is decidable for LL(k) grammars. Additional properties are also given.

Influence of the Electron Charge Distribution on Surface-Plasmon Dispersion

Abstract: The effects of the spatial variation of the electron density on the surface-plasmon dispersion relation are investigated. We show that measurements of that relation are a useful probe of the electron density in the surface region. Previous calculations on homogeneous materials have predicted a linear or quadratic dependence of the frequency on momentum parallel to the surface. We find that the usual surface-plasmon resonance frequency at first decreases with increasing momentum and then increases with further increases in momentum. This behavior agrees with the experimentally observed dispersion. Additional higher-frequency surface modes, similar to those observed in laboratory plasmas, are identified.

Metastable Immiscibility Surface in the System Na2O‐B2O3‐SiO2*

Abstract: Opalescence and clearing techniques were used to determine the metastable immiscibility surface for sodium borosilicate solutions. These results indicate that a three-liquid region, which may or may not be metastable to two-liquid regions, underlies the immiscibility surface.

Pulse Power Failure Modes in Semiconductors

Abstract: Semiconductor devices operating under both biased and unbiased conditions are vulnerable to permanent damage from relatively moderate levels of pulsed electrical energy, particularly of submicrosecond pulse duration. An experimental study was performed to determine the permanent damage levels associated with a number of different devices and to identify the failure mechanisms associated with each. The device types investigated included general purpose and high speed computer diodes, a medium power diode, medium frequency and UHF transistor amplifiers, and a dielectrically isolated diode gate expander. The permanent damage levels associated with these devices were determined both for positive and negative polarity pulses at different conditions of quiescent bias and pulse width. The pulse duration times included the range of 30 to 300 nanoseconds, and in some instances, up to 1 microsecond. Failure models for both thermal second breakdown induced damage to the semiconductor junction and thermal damage to the device interconnecting leads and metallization patterns were also developed.

Passive learning from television

Abstract: Learning is generally conceived as active and purposive behavior, involving motivation, practice, achievement. Here, the authors focus on "passive" learning, on what is "caught" rather than "taught," and on the processes by which such learning may take place. Passive learning is typically effortless, responsive to animated stimuli, amenable to artificial aid to relaxation, and characterized by an absence of resistance to what is learned, thus opening up possibilities that, depending on one's point of view, one may welcome or deplore. Herbert E. Krugman is responsible for corporate public relations and advertising research at the General Electric Company. Eugene L. Hartley is Dean of the College of Community Sciences at the University of WisconsinGreen Bay, and Emeritus Professor of Psychology, City College, CUNY.

Analytical and experimental studies of facilitated transport

Abstract: Facilitated transport is a process in which permeation through a liquid film is chemically augmented. Because of the scientific and engineering interest in this phenomenon, the purpose of this work was to carry out a detailed mathematical and experimental investigation of facilitated transport. The differential equations describing facilitated transport are presented, and a generally applicable numerical solution recently developed by G. M. Roe for this type of boundary value problem is summarized. The experimental investigation consisted of measuring the steady state rate of transport of nitric oxide through thin films of ferrous chloride solution and of determining independently the values of the system parameters of which the nitric oxide flux was a function. The experimental results were accurately predicted by using the model developed by Roe. This is the first demonstration of a general quantitative understanding of facilitated transport.

The Effect of Silicon and Manganese on the Oxidation Mechanism of Ni-20 Cr*

Abstract: Additions of 3% silicon or manganese to Ni-20 Cr reduced the oxidation rate, whereas additions of 1% had little effect. Three percent silicon alloys formed an inner scale of SiO2, and 3% manganese alloys formed an inner spinel layer of essentially pure MnCr2O4. The experimentally determined solid-state growth rate of NiCr2O4 was about 1000 times slower than the growth rate for Cr2O3. It has been established that the protective layer on Ni-20 Cr (Nichrome alloys) is the spinel and not Cr2O3 as previously postulated. The mechanism for scale growth is discussed for Ni-20 Cr alloys.

The crystal chemistry of apatite: structure fields of fluor- and chlorapatite

Abstract: tions were deduced. The size limits for substitutions in fluorapatite were 0.29 A

The effect of solidification rate on structure and high-temperature strength of the eutectic NiAl-Cr

Abstract: The eutectic NiAl-Cr, consisting of chromium rods in a NiAl matrix, was directionally solidified at rates varying from 1/4 to 30 in. per hr. The inter-rod spacing and elevated temperature tensile properties were measured and the structure determined for each solidification rate. The spacing, λ, obeyed the relation λ2V= Constant, whereV is the solidification rate. AtV greater than 1 in. per hr, a cell or colony structure formed and the cell size decreased with increasing solidification rate. At 600°C, the tensile strength increased substantially with decreasing inter-rod spacing, reaching 100,000 psi at the highestV. At 800° and 1000°C, the strength first increased then decreased at the highest solidification rates reaching maximum strengths of 63,000 psi and 47,000 psi, respectively. At 1200°C, the strength decreased slightly with increasing solidification rate. Fracture occurred by shear along grain boundaries and cell walls. The decreased strength at the highest solidification rates may be related to the increased cell boundary area.

High-current vacuum arcs. Part 1: An experimental study

Abstract: The vacuum or metal-vapour arc between butt electrodes of 6?75mm diameter, at separations up to 40mm, has been studied experimentally throughout a range of sinusoidal current loops up to 100kA peak. The appearance and properties of the copper-vapour discharge are shown to vary widely over this current range. The well known diffuse low-voltage vacuum arc which exists at a few hundred amperes develops into a constricted higher-voltage form as the current is increased, and, during 50Hz loops in excess of about 10KA peak, the arc produces grossly melted electrode spots at temperatures which are shown to be close to the boiling point of copper. High-pressure magnetically constricted arc columns develop from these large electrode spots, producing a discharge which bears many resemblances to a high-pressure high-current arc. Theoretical interpretations of these findings are presented in the companion paper.

Fan engine with counter rotating geared core booster

Abstract: The disclosure describes a turbofan engine having high and low pressure compressors wherein the low pressure compressor, or booster, comprises two counter rotating elements, a rotating duct which carries fan blades on its exterior surface and compressor blades on its interior surface and a conventional compressor rotor which rotates in a direction counter to the direction of rotation of the rotating duct. Alternative gearing schemes for coupling the rotation of the fan to the rotation of the low pressure compressor are shown.

A Review of the Literature on the Missile-Allocation Problem

Abstract: This paper reviews the missile-allocation-problem literature. The problem considered is: given an existing weapon force and a set of targets, what is the optimal allocation of weapons to targets? References are organized by type, characterized by submodel, discussed, and annotated. It is proposed that this review methodology by applied to other appropriate areas.

Linear Combination of Atomic Orbital-Molecular Orbital Treatment of the Deep Defect Level in a Semiconductor: Nitrogen in Diamond

Abstract: A deep defect level in a semiconductor is simulated by a large cluster of host atoms surrounding the defect The electronic states of the entire system are then computed by linear combination of atomic orbital-molecular orbital techniques The nitrogen donor in diamond is treated as an example A large Jahn-Teller distortion is predicted which forces the donor state down close to the valence band, in good agreement with experiment The calculated donor wave function agrees with EPR and electron-nuclear double resonence results

The strain rate dependent plastic flow behavior of zirconium and its alloys

Abstract: The effect of strain rate (10−5 { $$ \sim $$ } 10−1 min−1) on the plastic flow behavior was examined by means of tension tests over a range of temperatures (RT { $$ \sim $$ } 500°C). The principal material examined was Zircaloy-2, and the others were iodide zirconium and binary alloys of Zr-0.1 pct O and Zr-1.5 pct Sn by weight. In Zircaloy-2, the behavior was characterized by a sudden increase of flow strength with decreasing strain rate; concurrently the ductility decreased. Other interrupted and hold time experiments showed that the process is essentially that of a strain rate-induced strengthening phenomenon, with several features which could be identified with the strain aging process. It was further shown that the critical range of strain rates and temperatures at which the anomalous behavior took place could be correlated with the minimum in the strain rate sensitivity of flow stress. A similar but less pronounced flow behavior was observed with pure zirconium and its binary alloys, but with no marked change in the tensile ductility. From these results, the role of oxygen and tin on the early stage of plastic flow behavior was discussed in terms of dislocation-impurity interaction mechanisms. It was however concluded that these elements are not directly responsible for the ductility loss at slow strain rate in Zircaloy-2.

Liquid–liquid phase separation in multicomponent polymer solutions. IX. Concentration‐dependent pair interaction parameter from critical miscibility data on the system polystyrene–cyclohexane

Abstract: Critical miscibility data obtained from measurements of phase-volume ratios have been used to calculate the concentration dependence of the pair interaction parameter for the system polystyrene–cyclohexane. The measured temperature and concentration ranges are 11–30°C and 4–18% polymer by weight, respectively. With the Gibbs free energy of mixing expressed in polymer segment mole fractions, x*, the pair interaction parameter is g(x*, T) = 0.4961 + 71.92/T + 0.2312x* + 0.0750x*2. In a polymer volume fraction formulation the parameter is g(φ, T) = 0.4099 + 90.65/T + 0.2064 φ + 0.0518 φ2, which approximates to χ(φ, T) = 0.2035 + 90.65/T + 0.3092 φ + 0.1554 φ2. Comparison of the temperature and concentration dependence with that obtained by other authors shows very good agreement, even when extensive extrapolations in temperature and concentration are applied. The present function is believed to be the most accurate. Solutions of mixtures of two narrow-distribution polystyrenes in cyclohexane show separation into three liquid phases under the exact conditions predicted by theoretical calculation with the present pair-interaction function.

The Effect of Biaxial Stresses on Fatigue and Fracture

Abstract: The results are presented of an analytical and experimental program which was conducted to determine if a biaxial stress field produces a significant effect on the fatigue and fracture behavior of thin plates. The materials tested were 6061-T4 and 6061-T6 aluminum sheets and plexiglas sheets. The experimental program included fracture tests with various magnitudes of biaxial load at fracture and fatigue tests with sinusoidal loading normal to the crack and either constant or sinusoidal stresses applied parallel to the crack. The effect of nonsingular stresses on the behavior of a crack is examined from both a linear elastic and an elastic-plastic viewpoint. The experimental study indicates that a biaxial stress field does affect the behavior of a crack in a thin sheet. An increase in the apparent fracture toughness with increasing biaxial load was observed experimentally but as yet cannot be adequately explained using linear fracture mechanics theory. Biaxial stresses were found to produce a shift in the fatigue crack growth rate data, and it is shown that this shift can be predicted using several empirical fatigue crack propagation models.

AC Flashover Tests at Project UHV on Ice-Coated Insulators

Abstract: This paper presents results of experimental studies on the flashover strength of ice-coated insulators. Two types of flashover have been found on ice-covered insulators. One is caused by hard and dry ice formed in temperatures lower than 15 °F. Another is caused by mixed conditions of ice and misty rain in relatively high temperatures of 20 to 30 °F. The flashover voltages of 25 units of 53/4- by 10-inch insulators were 288 kV (phase to ground) in the former condition and 246 kV in the latter. These results were obtained for uncontaminated insulators. Nonuniform voltage distribution along the insulator string produces these low flashover voltages. These tests were conducted at General Electric's Project UHV in the winter season of 1968-1969.

A method of manufacturing a semiconductor device utilizing a flexible carrier

Abstract: Semiconductor devices such as transistors are manufactured by use of a longitudinally extending tape-like carrier including a metallic layer secured to a flexible insulative layer, with the insulative layer having centrally located longitudinally spaced apertures. These apertures are covered by the metallic layer and are dimensioned to encompass contact regions of a semiconductor body such as a transistor or monolithic integrated circuit pellet. Longitudinally spaced sets of finger-like leads are formed from the metallic layer with the inner portions of the leads of each set extending cantilever-wise within the periphery of a respective adjacent aperture for registry with the contact portions of a semiconductor pellet. The leads of each set are connected to the contacts of a pellet registered with the adjacent aperture, the respective pellets and portions of the leads connected thereto are encapsulated, and the carrier may be reeled or otherwise automatically handled, with individual devices obtainable by severance from the carrier.

Reaction vessel for high pressure apparatus

Abstract: AN IMPROVED REACTION VESSEL CONSTRUCTION FOR THE COMPACTION OF A MASS OF DENSE, STRONG PARTICLES E.G. DIAMOND IS DISCLOSED. THIS IMPROVED CONSTRUCTION EMBODIES A MECHANICALLY UNSTABLE STRUCTURAL SYSTEM TO PREVENT THE FORMATION OF PRESSURE-SUPPORTING GEOMETRIES WITHIN OR ENCIRCLING THE MASS.

Mobile locator system for metropolitan areas

Abstract: A locator system is disclosed wherein the vehicle whose location is unknown transmits a short, modulated radio frequency pulse. Receiving stations about the periphery of the area being serviced phase compare the received signal with a standard time reference signal. The phase difference is used to determine the arrival time differences at the known locations of the receiving stations from which the location of the vehicle may be determined. The wavelength of the modulating signal is generally greater than the maximum distance encountered in the service area. The effects of multipath reflections are minimized by utilizing a space dispersed antenna.