Showing papers by "Nagoya Institute of Technology published in 1987"
190 citations
TL;DR: The melting temperatures of natural and synthetic monazite and xenotime (rare-earth ortnophosphates) were measured, using a heliostat-type solar furnace as mentioned in this paper.
Abstract: The melting temperatures of natural and synthetic monazite and xenotime (rare-earth ortnophosphates) were measured, using a heliostat-type solar furnace. The results obtained are as follows: natural monazite from Japan (2057°40°C), synthetic monazite RPO4 (R=La, 2072°20°C; R=Ce, 2045°20°C; R=Pr, 1938°20°C; R=Nd, 1975°20°C; R=Sm, 1916°20°C), and synthetic xenotime RPO4(R=Y, 1995°20°C; R=Er, 1896°20°C).
127 citations
118 citations
TL;DR: In this article, the composition of the material with maximum conductivity has been estimated to be MgZr4(PO4)6 having the same crystal structure as that of NaZr2(PO 4)3, and the conductivities are 2.9 × 10−5 and 6.1 × 10 −3Scm−1 at 400 and 800 °C, respectively.
96 citations
01 Jan 1987
TL;DR: In this article, the Boltzmann equation and a Monte Carlo simulation method were used to determine the inelastic and elastic electron collision cross-sections for molecules of interest in plasma processes, gas lasers, gaseous dielectrics, diffuse discharge opening switches, space science and radiation research.
Abstract: Elastic and inelastic electron collision cross-sections for molecules of interest in plasma processes, gas lasers, gaseous dielectrics, diffuse discharge opening switches, space science and radiation research have been determined from available electron beam and electron swarm data utilizing the Boltzmann equation and a Monte Carlo simulation method. The method is the same as the one used by Phelps, Crompton, Thomas, Tagashira, and their co-workers. The discussion will cover a number of molecular species, e.g., F2, HCl, SO2, CH4, SiH4, CF4, CCl2F2, CCl4, SF6, C2H6, and Si2H6, in the 0 to 1000 eV energy range. In spite of several studies, inelastic collision cross-sections for N2 are still not well-known. This matter will be briefly addressed. The discussions will then focus mainly on the cross-sections for CF4. Some calculated results of electron swarm data for CF4 and CF4-inert gases mixtures will be presented.
90 citations
TL;DR: In this article, an elastic constitutive model is developed for flexible fiber composites which are composed of continuous curved fibres and ductile matrices, and the prediction of nonlinear stress/strain responses of the composites is performed by a stepwise incremental analysis.
65 citations
TL;DR: In this article, a constitutive model for sands and clays by which the general strain increments (dex, dey and dγxy) are directly related to the general stress increment (dσx, dσy, and dτxy) is proposed.
41 citations
TL;DR: In this paper, the annealing effect of ethylene ionomers at various temperatures and for various periods was studied by differential scanning calorimetry, showing that the melting peak at the lower temperature, which was assigned to bundlelike crystal owing to a Hoffman-Weeks relationship, shifted to a higher temperature with the annaling temperature and period, indicative of recrystallization.
Abstract: The annealing effect of ethylene ionomers annealed at various temperatures and for various periods was studied by differential scanning calorimetry. Two endothermic melting peaks were observed for all the ethylene ionomers annealed. The melting peak at the lower temperature, which was assigned to bundlelike crystal owing to a Hoffman-Weeks relationship, shifted to a higher temperature with the annealing temperature and period, indicative of recrystallization. There is physical cross-linking consisting of ionic aggregates, such as multiplets and clusters in ethylene ionomers. The crystallization kinetics of ethylene ionomers was fundamentally similar, but different from that of low-density polyethylene. Crystallization and recrystallization suggested a mobile ethylene chain in both amorphous regions and ionic aggregates even in the presence of cross-linking.
41 citations
TL;DR: Spectroscopic studies and chemical transformation have established the structure of physalin L as 25- epi -3,4-dehydro-2,3,25,27-tetrahydrophysalin A.
40 citations
TL;DR: In this article, the effect of the physical aging of ethylene ionomers was studied for the samples with the acid content of 5.4 mol%, and the degree of neutralization, 0, 60% Na, 60%, Zn, and 90% Zn.
Abstract: The effect of the physical aging of ethylene ionomers was studied for the samples with the acid content of 5.4 mol%, and the degree of neutralization, 0%, 60% Na, 60% Zn, and 90% Zn. The information about the crystal and the cluster part of the physically aged ionomers was obtained by differential scanning calorimetry and by dynamic viscoelastic measurements, respectively. The degree of crystallinity and the dynamic modulus for the ionomers of the degree of neutralization 0%, 60% Na and 60% Zn increased gradually with the aging time; on the other hand, the crystallinity of 90% Zn remained constant and the modulus at 100°C increased to a certain value up to a period of 100 h, but thereafter the crystallinity increased remarkably and the modulus remained. These facts indicate that the crystallization of neutralized ethylene ionomer starts after clustering and the clustering would finish at early stage of the physical aging for intermediately neutralized ethylene ionomer. The physical aging effect of the ethylene ionomers was, thus, found to be important to material design.
37 citations
TL;DR: In this article, a review of thermally stimulated polarization/depolarization current and its relationship with d.c/a.c. conduction and dielectric relaxation is presented.
Abstract: Biasing of an oxide glass by an applied electric field is reviewed with emphasis on the present author's works on thermally stimulated polarization/depolarization current and its relationship with d.c./a.c. conduction and dielectric relaxation. Evidence is presented supporting the idea that in oxide glass conduction should be accompanied by polarization, termed conduction polarization.
TL;DR: In this paper, the cause of UV-induced coloring of calcium aluminate glasses was investigated and the most effective wavelength agreed with that of the apparent absorption edge was found to be due to the emergence of an aluminum-oxygen hole center and an ozonide (O3-).
Abstract: Calcium aluminate glasses show high sensitivity to ultraviolet radiation without the doping of optically active components. In this paper, photosensitive characteristics and the cause of UV-induced coloring were investigated for these glasses. Ultraviolet rays below 270 nm were effective for inducing the coloring. The most effective wavelength agreed with that of the apparent absorption edge. In the ternary system with SiO2 or GeO2, the sensitivity was monotonically reduced with the amount of the third component and almost vanished for the compositions containing 40 mol%. On the basis of the establishment of a close correlation between two optical absorption bands and two electron spin resonance signals induced by UV illumination, the UV-induced coloring was concluded to be due to the emergence of an aluminum-oxygen hole center (Al-OHC) and an ozonide (O3-).
TL;DR: In this article, a fine powder of the oxide was suspended in PVA solution containing a dispersant, and the viscous suspension was extruded as a filament into precipitating medium and the filament was coiled on a winding drum.
Abstract: The suspension spinning of Ln-Ba-Cu-0 (Ln=Dy, Y, Ho and Er), Bi-Sr-Ca-Cu-0 and Tl-Ba-Ca-Cu-0 was examined to prepare a long filament with high Jc. A fine powder of the oxide was suspended in PVA solution containing a dispersant. The viscous suspension was extruded as a filament into precipitating medium and the filament was coiled on a winding drum. The obtained filament about 200 μm in diameter was heated to remove volatile components and to generate the superconducting phase.
TL;DR: In this paper, the stress and strain of GaAs on Si grown by using strained superlattice intermediate layers and a two-step growth method are characterized by the photoluminescence, X-ray diffraction and the curvature radius.
Abstract: The stress and strain of GaAs on Si grown by using strained superlattice intermediate layers and a two-step growth method are characterized by the photoluminescence, X-ray diffraction and the curvature radius. The strain of GaAs grown using strained superlattice intermediate layers is smaller than that grown by the two-step growth method.
TL;DR: In this paper, the metallic-antimony-induced allylation of aldehydes by allylic halides and phosphates gave high yields of the corresponding homoallylic alcohols, regioselectively.
TL;DR: In this article, the electrocatalytic reduction of carbon dioxide was carried out on two types of Au plate electrode; one was partially immersed in electrolyte solution containing CO2 and the other was completely immersed.
TL;DR: In this paper, the authors investigated the effect of codopant oxisides (solvation shell) on the optical properties of Nd and Ce ion activated silica glasses and their codoping effects on the samples prepared by O2/Ar plasma torch CVD.
Abstract: Optical properties of Nd and Ce ion activated silica glasses and their codoping effects of Al, P and F have been investigated on the samples prepared by O2/Ar plasma torch CVD. At a low doping level of 1×1019/cm3, most doped Nd ions begin to cluster. This results from the high enthalpy state of their coordination in which they are isolatedly dispersed in the matrix. Codoping of Al and P effectively dissolves the clustering and probably causes the coordination consisting of codopant oxisides (solvation shell), while that of F does not change the absorption and fluorescence properties of Ce doped glass due to Si-F covalent bonding formation. Preparation dependent defect like peroxy linkage in SiO2 glass is suggested to have influence upon doping state of Ce doped at the same level with the defect density, on the basis of EPR centers induced by XeCl excimer laser irradiation. Possible application of solvation shell model for coordination control around active ions in SiO2 glass is discussed.
TL;DR: In this article, the EPR measurements on Fe 3+ centres in RbCdF 3 and CsCdFsF 3 for crystals co-doped with Li + ions have been made in the cubic phase of host crystals.
Abstract: EPR measurements on Fe 3+ centres in RbCdF 3 and CsCdF 3 for crystals co-doped with Li + ions have been made in the cubic phase of host crystals. In both the crystals spectra from two kinds of Fe 3+ tetragonal centres associated with Cd 2+ vacancy (V Cd ) and Li + ion at the nearest-divalent-cation sites have been observed. From obtained fine structure parameters in the spin Hamiltonian the metal-ligand distances have been determined by the superposition model. The fine structure parameters have been explained well by the obtained metal-ligand distances, which show the contraction ordistortion of fluorine octahedra surrounding Fe 3+ ions.
TL;DR: In this paper, allylic phosphates allylate ketones and aldehydes in the presence of samarium(II) iodide were shown to preserve the olefin geometry, however, regio-and stereoselectivity are not high.
TL;DR: In this paper, a uniform gels by the sol-gel method using metal alkoxides has been examined to prepare bulk Na2OAl2O3 crystalline phases in a wide range of composition.
TL;DR: In this article, a diffraction of rayons X du systeme ternaire Ti 1−y V y H x avec 0≤y≤1 and 0≥x≤2.
Abstract: Etude par diffraction de rayons X du systeme ternaire Ti 1−y V y H x avec 0≤y≤1 et 0≤x≤2. Analyse cristallographique des phases composant ce systeme. L'une des caracteristiques de ce diagramme est la presence de la phase β dans la region riche en titane. La variation de stabilite de cette phase est discutee en fonction de la structure de bande electronique de ce systeme ternaire
TL;DR: This paper compares several variants of the modified policy iteration algorithms for finding the optimal control for the service rate for a tandem queueing system that has a general cost structure and shows that the optimal Control problem can be solved within a reasonable computation time.
Abstract: This paper discusses the use of modified policy iteration algorithms for finding the optimal control for the service rate for a tandem queueing system that has a general cost structure. It compares several variants of the algorithms and shows that the optimal control problem can be solved within a reasonable computation time.
TL;DR: In this paper, a GaAs was grown on a Si substrate through a SiO2 mask using superlattice intermediate layers by MOCVD and ridge growth was observed at the substrate/mask interface.
Abstract: GaAs was grown on a Si substrate through a SiO2 mask using superlattice intermediate layers by MOCVD. Single and poly crystalline GaAs layers were grown on the Si substrate and on the mask, respectively. Ridge growth was observed at the substrate/mask interface. The relationship between the ridge growth properties (the shape and the height) and the growth conditions were made clear. The ridge growth rate increases exponentially with approaching the interface. The ridge shape was determined by the surface migration and the gradient in the gas phase concentration of the Ga active species. The ridge growth height of GaAs grown on GaAs was higher than that grown on Si. These results could be explained by taking account of the difference in the surface migration length of the Ga active species on GaAs and Si substrates.
Nagoya University1, CERN2, Sapienza University of Rome3, University College London4, University College Dublin5, Birkbeck, University of London6, Women's College, Kolkata7, Nagoya Institute of Technology8, Toho University9, Yokohama National University10, Utsunomiya University11, Gifu University12, Aichi University of Education13
TL;DR: In this paper, the simultaneous production of four charmed particles in interactions induced by 350 GeV/c π − mesons in stacks of nuclear emulsions was reported, which required the presence of at least one muon with a high component of momentum transverse to the beam direction.
TL;DR: The phase diagram for the Fe-rich Fe-Al-Co ordering system has been determined by observing phase separation by means of electron microscopy and magnetization-measurements as mentioned in this paper.
TL;DR: In this paper, the corrosion behavior of carbon steel, austenitic stainless steels, Ni-base alloys, and nickel in hot, concentrated caustic soda solutions at the active potential range was investigated.
Abstract: The corrosion behavior of carbon steel, austenitic stainless steels, Ni-base alloys, and nickel in hot, concentrated caustic soda solutions at the active potential range was investigated
TL;DR: In this article, a peroxylinkage and a molecular oxygen-related defect was found in calcium aluminate glasses and the properties of the corresponding crystalline phases and melts were described.
Abstract: Calcium aluminate glasses show an excellent photosensitivity to ultraviolet-radiation without the doping of optically active components. The photosensitivity is considered to originate from the presence of a peroxylinkage and a molecular oxygen. This article reviews a photosensitive mechanism proposed and describes the relationship between the presence of these oxygen-related defects in these glasses and the characteristics of the corresponding crystalline phases and melts.
TL;DR: In this paper, a pseudo polymeres ont deux chaines laterales alkyles tout les deux carbores de la chaine principale, et. al.
Abstract: Synthese de pseudo polymeres peigne par polymerisation radicalaire de fumarates dialkyl ou d'itaconates dialkyl. Ces polymeres ont deux chaines laterales alkyles tout les deux carbores de la chaine principale. Etude de la cristallisation des chaines laterales
TL;DR: In this paper, the intensity of neutron scattering for tunnel splitting levels of NH + 4 ion is calculated in terms of the orientationally localized states and the k-dependence of the transition integral and the temperature dependence of the spectra are derived.
Abstract: The intensity of neutron scattering for tunnel splitting levels of NH + 4 ion is calculated in terms of the orientationally localized states. The k -dependence of the transition integral and the temperature dependence of the spectra are derived. In conclusion, C 3 v , orientation is the best model to yield the observed spectra and two big additional peaks are anticipated in E >3 meV.