Showing papers by "Mitsubishi Electric published in 1978"
TL;DR: In this article, the epitaxial layers of GaAs were grown on GaAs(100) at substrate temperatures ranging from 400° to 600°C by molecular beam epitaxy.
100 citations
TL;DR: In this article, the α-dispersion temperature of polystyrene and polymethylmethacrylate (PMMA) filled with glass beads and mica flakes was investigated.
Abstract: Dynamic mechanical properties of polystyrene (PS) and polymethylmethacrylate (PMMA) filled with glass beads and mica flakes have been investigated. The α-dispersion temperature (Tα) increases with filler content in each system. The increase in Tα is larger for PMMA than for PS in the case of the same filler; the increase in Tα is larger for mica than for glass in the case of the same polymer. Polymer-filler interaction energies have been estimated from heats of adsorption of the monomers of the filler surfaces determined by solid gas adsorption chromatography. The increase in Tα can be related to the extent of polymer-filler interaction energy. The thickness of the partially immobilized layer on the filler surface has been estimated to be the orders of 0.1 and 1.0 μm, respectively, for the mica and the glass-filled systems.
91 citations
TL;DR: In this article, various factors controlling flashover of solid insulators in pressurized SF6, are reviewed and their influences in gas insulated systems are discussed from a practical point of view.
Abstract: Various factors controlling the flashover of solid insulators in pressurized SF6, are reviewed and their influences in gas insulated systems are discussed from a practical point of view. Flashover voltage of clean insulator surface is under the influence of the insulator-metal contact as well as the macroscopic electric field distortion due to the high dielectric permittivity of solid insulator. Conducting particles or even fine metal powder can reduce the flashover voltage. Their effects are strongly dependent on the position they are located, the size of the insulator and gas pressure. Humidity of SF, gas should be strictly governed in SF, gas insulated apparatuses, since the condensation of water can decrease flashover voltage considerably. Decomposition products of SF6 due to the arcing in switchgears are deleterious to epoxy insulators particularly when silica is used as their filler. The decomposition products decrease the leakage resistance on the insulation surface. The field strength near positive electrode is enhanced by the electrolytic effect in the surface conduction layer. In some extreme condition, it initiates tracking on the insulator surface.
91 citations
TL;DR: In this article, the thermal oxidation of a silicon nitride film was evaluated at temperatures ranging from 900°C to 1100°C and under water vapor partial pressures ranging from 0.25 atm to 0.95 atm.
Abstract: The thermal oxidation of a silicon nitride film was evaluated at temperatures ranging from 900°C to 1100°C and under water vapor partial pressures ranging from 0.25 atm to 0.95 atm. The oxidation rate was measured by ellipsometry and the results were compared with those of simultaneously oxidized silicon substrates. The conversion ratio, which is the thickness ratio of a grown oxide film to a consumed nitride film, of 1.64 was obtained with small fluctuation. The oxidized nitride thickness xn was found to be proportional to t2/3, where t is the oxidation time. This relationship is consistent with a proposed oxidation model. The figure of merit m was defined as the masking effect of a nitride film. It was found that a large m value was obtained when the film was oxidized at low temperature and under high water vapor partial pressure.
52 citations
TL;DR: In this article, the effect of particle size on the modulus can be explained in terms of orientation of the filler by comparing the experimental data with Wu's and Padawer and Beecher's predictions of the dynamic mechanical properties of poly(methyl methacrylate) (PMMA) filled with mica flakes (M) or glass beads (G).
Abstract: Dynamic mechanical properties of poly(methyl methacrylate) (PMMA) filled with mica flakes (M) or glass beads (G) were investigated as functions of particle size and filler concentration. With increasing particle size, dynamic modulus E′ slightly decreases for system G, while it increases rapidly at first and then approaches the limiting value for system M. Primary dispersion temperature Tα increases with increasing filler concentration. With increasing particle size, Tα decreases for system G but increases for system M. For the mica-filled system, the effect of particle size on the modulus can be explained in terms of orientation of the filler by comparing the experimental data with Wu's and Padawer and Beecher's predictions of the modulus. In order to explain the dependence of Tα on particle size and concentration, an equation for Tα has been proposed:
where Kf is a constant and S is the specific surface area of filler per gram of polymer. For system G, Tα can be expressed by the above equation, irrespective of particle size and filler concentration. In the case of system M, it is suggested that Tα is affected also by orientation in addition to the surface area of the filler.
34 citations
TL;DR: In this paper, the total amount of CH radicals produced in the reaction zone is estimated by comparing NH∗ emission intensity with NO for the flame of added fuel nitrogen, and it is shown that the amount is uniquely determined by the mixture strength without depending on the flame temperature and is also scarcely influenced by fuel.
34 citations
30 citations
TL;DR: An optical branch and switch based on a unique mirror effect were fabricated by varying the amount of Ti diffused in a LiNbO(3) waveguide, and their properties were investigated.
Abstract: An optical branch and switch based on a unique mirror effect were fabricated by varying the amount of Ti diffused in a LiNbO3 waveguide, and their properties were investigated. In this type of optical branch, the branching ratio of the light intensity could be varied by the electric field as well as by the separating angle and the effective indices of the waveguides. The main features of this optical switch are (1) small and simple electrode form and (2) a separating angle large enough to accommodate a number of switches on a single substrate. The ratio of the optical branch light intensity to that of the main waveguide was varied from 0.10 to 12.4 by applying the electric field from 0 V/μm to 8 V/μm.
29 citations
TL;DR: In this article, a numerical method to find the significant eigenvalues (damping factors and natural frequencies) and eigenvectors (oscillation mode shapes) in the dynamic stability range of a power system is presented.
Abstract: This paper deals with a numerical method to find the significant eigenvalues (damping factors and natural frequencies) and eigenvectors (oscillation mode shapes) in the dynamic stability range of a power system.
27 citations
TL;DR: In this paper, the deformation and fracture behavior of stator windings subjected to static and cyclic bending loadings was analyzed. And the reliability of newly developed insulation systems was evaluated on a 1300 MVA water cooled generator.
Abstract: This paper presents the deformation and fracture behavior of stator windings subjected to static and cyclic bending loadings, and the reliability of newly developed insulation systems. The flexural deformation characteristics are revealed on the curved end portion of the stator windings for a 1300 MVA water cooled generator. The fatigue characteristics are examined on the test bars with three different kinds of the developed insulation systems. Comparing those results with calculated thermal strain, it has been confirmed that the insulation systems have sufficient mechanical strength to withstand thermal cycling in service.
25 citations
TL;DR: In this paper, the dielectric strength of superconductivity and low resistivity at cryogenic temperatures is investigated and whether Paschen's law is valid over a wide range of low temperatures or not.
01 Apr 1978
TL;DR: Light emission from an epoxy resin specimen with pin-plane electrodes was studied using a refrigerated 13-stage photomultiplier and a 4-stage image intensifier as mentioned in this paper.
Abstract: Light emission from an epoxy resin specimen with pin-plane electrodes was studied using a refrigerated 13-stage photomultiplier and a 4-stage image intensifier. In the pretreeing period weak light, comparable in intensity to that resulting from thermal photomultiplier noise, was observed together with visible effects of deterioration such as fine shadow lines and void formation and growth. The deterioration in the void-free state is probably caused by hot electron bombardment of resin molecules in the high field region.
TL;DR: In this paper, a computer program was developed for the three-dimensional calculation of the absorbed energy density in polymer films on substrates in electron beam lithography, based on the reciprocity principle proposed by Chang.
Abstract: A computer program has been developed for the three-dimensional calculation of the absorbed energy density in polymer films on substrates in electron beam lithography. In this calculation the Monte Carlo results have been used for the radial energy intensity distribution for a point source electron beam. The program is based on the reciprocity principle proposed by Chang. Some exposure experiments have been conducted with an electron resist of PMMA (polymethyl methacrylate) for isolated patterns in the from of a line of finite length (8.1 µm) as well as of a rectangle (3.1×8.1 µm2) in order to check the reliability of the calculations. Operating beam voltages used for the investigation are 14 and 20 keV. The electron resist thickness is 8000 A. Relatively good agreement has been obtained between the calculated and the experimental results. This program is applicable to an arbitraty pattern, and therefore it will be useful for investigations of the proximity effect in electron beam lithography.
TL;DR: Good agreement was obtained between the experimental and computed results of the absorption cross section of the gamma-0 band of nitric oxide.
Abstract: The absorption by the γ-0 band of nitric oxide at 2260 A has been studied. Its apparent absorption cross section depends both on total pressure and its concentration. In order to investigate these absorption characteristics quantitatively, a line by line analysis was made. Good agreement was obtained between the experimental and computed results of the absorption cross section.
TL;DR: In this article, a UHF power transistor developed by using arsenic implantation is characterized by a power gain of 5 dB with an associated collector efficiency of 60%, and a saturated power of 22W, at 900 MHz with 12.5 V dc supply voltage.
Abstract: The basic feature of heavy dose arsenic implantation is studied with an aim of the application to shallow emitters of bipolar devices. Secondary defect caused by heavy dose arsenic implantation is significantly affected by an annealing atmosphere. A TEM observation and an electrical measurement show that the high temperature annealing in an N2 atmosphere results in a high quality crystalline layer. The arsenic concentration profile measured by a He+ backscattering method is well predicted by the computer simulation with the concentration dependent diffusivity. The transistor with arsenic-implanted emitter and boron-implanted base has shown to have negligible emitter-push effects. A UHF power transistor developed by using arsenic implantation is characterized by a power gain of 5 dB with an associated collector efficiency of 60%, and a saturated power of 22W, at 900 MHz with 12.5 V dc supply voltage.
19 Jun 1978
TL;DR: The outline and the experimental results of the system which automatically restructures and partitions a logic circuit consisting of standard SSI's and MSI's so that the gate types and the numbers of input/output terminals of the reorganized circuits are within the restrictions of the specified LSI are described.
Abstract: Described is the outline and the experimental results of the system which automatically restructures and partitions a logic circuit consisting of standard SSI's and MSI's so that the gate types and the numbers of input/output terminals of the reorganized circuits are within the restrictions of the specified LSI.
TL;DR: In this paper, high-power field effect transistors were fabricated on molecular-beam epitaxial GaAs crystals, with a power output at 1 dB gain compression of 4.0 W, a corresponding linear gain of 5.4 dB and a power-added efficiency as high as 35% were realized.
Abstract: High-power GaAs field-effect transistors were fabricated on molecular-beam epitaxial GaAs crystals. Devices with a power output at 1 dB gain compression of 4.0 W, a corresponding linear gain of 5.4 dB and a power-added efficiency as high as 35% have been realised.
TL;DR: A digital audio system now includes a home use VTR as record and reproduce media that insures ready use of existing TV equipments, their peripherals, and networks.
Abstract: A digital audio system now includes a home use VTR as record and reproduce media. In this system, audio signal is converted into digital codes by PCM, which are again converted such that the resultant signal be identical with NTSC TV format. This insures ready use of existing TV equipments, their peripherals, and networks.
TL;DR: Aluminum diffusion into silicon nitride films at temperatures in the range 450-530°C was studied by Auger electron spectroscopy in conjunction with depth profiling in this paper, where the activation energy for the diffusion of aluminum and the diffusion coefficient were found to be 2.0±0.3 eV and (7.3±3.5) x 10 -3 cm 2 s -1, respectively.
TL;DR: The diffusion mechanism of arsenic implanted into silicon dioxide is studied by the MeV He+ backscattering method in this article, where the diffusion coefficient of elemental arsenic is extremely small, i.e., smaller than 1×10−17 cm2/sec at 1200°C.
Abstract: The diffusion mechanism of arsenic implanted into silicon dioxide is studied by the MeV He+ backscattering method. The diffusion coefficient of elemental arsenic in silicon dioxide is extremely small, i.e., smaller than 1×10−17 cm2/sec at 1200°C. The arsenic diffusivity in silicon dioxide is enhanced by introducing extra oxygen into silicon dioxide from an oxidizing atmosphere or by additional oxygen implantation. Arsenic interacts with the extra oxygen, and an arsenic‐oxygen compound might be formed which has a much larger diffusivity than elemental arsenic.
TL;DR: In this paper, a new type of shaped-beam radar antenna having good polarization characteristics is described, which is composed of a dual doubly curved reflector system and a feed horn with good axial ratio, such as a dualmode horn.
Abstract: A new type of shaped-beam radar antenna having good polarization characteristics is described. This antenna is composed of a dual doubly curved reflector system and a feed horn with good axial ratio, such as a dual-mode horn. The rotationally symmetrical beam of the feed horn can be converted into a shaped beam by the reflector system without degradation of the axial ratio. The design of this type antenna is discussed and the experimental results of a model antenna with a cosecant squared beam are shown. Integrated cancellation ratio of the model was 22 dB.
TL;DR: In this paper, the authors investigated the molecular motion in cured epoxy resin filled with mica flakes and found that the filler immobilizes the chain segments and causes a different distribution of local mobility around the junction point.
Abstract: Molecular motion in cured epoxy resin filled with mica flakes was investigated by dynamic mechanical and broad-line nuclear magnetic resonance measurements. Temperature dependences of dynamic modulus and tanδ were determined at 10 Hz for samples containing various amounts of filler. A primary dispersion temperature, T∞, corresponding to the glass transition, shifts to higher temperature with increasing filler volume fraction Vf. The magnitudes of the slope parameters Hr (representing storage modulus E′ data below Tg) decreased with increasing Vf, but Hg (representing E′ data below Tg) remained nearly constant over the whole loading range studied here. NMR line shapes were observed over the temperature range from room temperature to about 200°C for unfilled and filled samples. Each sample showed a distorted line shape in the transition region where major narrowing occurs. The distorted line shape was decomposed into both broad and narrow components by Gaussian analysis. The temperature range where both components can be obtained becomes broader with increasing filler content. The possibility is set forth that the filler immobilizes the chain segments and causes a different distribution of local mobility around the junction point.
27 Jun 1978
TL;DR: In this paper, the performance characteristics of the non-reciprocal remanence ferrite phase shifter have been improved by the adoption of the grooved waveguide, and the Figure-of-Merit and handling power level have been compared with those of the ordinary one.
Abstract: For the purpose of improving the performance characteristics of the nonreciprocal remanence ferrite phase shifter, new configurations are proposed here which are characterized by the adoption of the grooved waveguide. Some results calculated mainly as a function of the grooved waveguide height are shown and compared, in good agreement, with experimental values. The Figure-of-Merit and handling power level of the proposed phase shifter are discussed in comparison with those of the ordinary one.
TL;DR: In this paper, the settling behavior of fillers in thermosetting epoxy casting resins during cure is investigated using a theory based on a modified Stokes' law equation, and the experimental results agree well with the theoretical predictions when the settling distances are small and the particle size distribution is narrow.
Abstract: Using a theory based on a modified Stokes' law equation, the settling behavior of fillers was investigated (glass beads and silica powder) in thermosetting epoxy casting resins during cure. In this study a suspension (a thermosetting epoxy casting resin) containing a large amount of filler particles is assumed to be a homogeneous fluid, and the settling phenomena are treated such that one or more particles of the filler settle into the homogeneous fluid under gravity without interference from other particles. The viscosity increase of the fluid during cure is taken into consideration. The experimental results agree well with the theoretical predictions when the settling distances are small and the particle size distribution is narrow. When these conditions are not satisfied, various effects are observed such as convection, filtering, combination, bottom effect, and a broad particle size distribution. In addition, the formation of a compression zone and of a compaction zone are clearly observed.
TL;DR: In this article, low energy electron loss spectroscopy (ELS) and Auger-AES have been applied for the studies of the interaction of H 2 S molecules with Si(111)7 × 7 surfaces.
01 Feb 1978
TL;DR: In this article, the leakage flux of the electromagnet is taken into account and the method of averaging is applied to nonlinear differential equations which describe the system under the assumption that the system is operating near an equilibrium state.
Abstract: This paper presents an analysis of a magnetic suspension device utiising a tuned LCR circuit. The leakage flux of the electromagnet is taken into account. The method of averaging is applied to nonlinear differential equations which describe the system under the assumption that the system is operating near an equilibrium state. Response characteristics, i.e. the gap distance in an equilibrium state and the equivalent spring constant, are theoretically obtained. The static and dynamic stability criteria are sought. It is demonstrated that a quasiperiodic oscillation occurs in a system which is dynamically unstable. in this case the suspended object oscillates periodically in the steady state. The analytical result is confirmed by experimental observation.