Showing papers by "Utsunomiya University published in 1989"

Dependence of the Band Bending of the Oxide Semiconductors on pH

Abstract: The dependence of the band bending of the oxide semiconductors on pH have been studied by measuring the flatband potential photopotential, and rest dark potential in the solution without redox species. The rest dark potentials were almost constant with pH, while the flatband potential showed the 60 mV/pH dependence. This indicates that only the band in the space charge layer bends by pH with the 60 mV/pH dependence under the rest dark potential state. The flatband states were held at for , , , and , respectively, under the rest dark potentials The above phenomenon is based on the reaction of the oxide surface state with H+ and/or OH− in the solution. This mechanism is described in detail. The enhancement of the water photolysis on catalyst by the alkaline treatment is well explained by the large band bending in alkaline solution under the rest dark potential state.

Emulsifying Properties of Bovine Milk Fat Globule Membrane in Milk Fat Emulsion: Conditions for the Reconstitution of Milk Fat Globules

Abstract: A procedure for the reconstitution of milk fat globules (MFG) stabilized with milk fat globule membrane (MFGM) was developed. MFG was reconstituted by homogenizing a mixture of 1% MFGM and 25% milk fat at 45°C and at pH 7.0 for 1 min. The emulsifying properties of MFGM were evaluated by emulsifying activity (EA), emulsion stability (ES), whippability and foam stability. Of the variables affecting the reconstitution of MFG, prolonged homogenization decreased EA and ES. About 25% milk fat gave maximal EA and ES, increasing the MFGM concentration increased both EA and ES, which were also influenced by the pH level. Foam disappeared at >30°C.

Methods for culture of Bombyx mori wing discs

Abstract: A culture method forBombyx wing discs is described. Grace's insect medium,Bombyx hemolymph, and moderate doses of ecdysterone (0.02 to 0.1 µg/ml) were necessary for complete imaginal differentiation ofBombyx wing discs. This procedure is useful for understanding ecdysteroid action on insect imaginal differentiation and metamorphosis.

Effects of Ultrasound on Dyeing of Nylon 6

Abstract: In order to study the effect of ultrasound, amorphous and unoriented nylon 6 films were dyed with disperse, acid, acid mordant, and reactive dyes with and without ultrasound. Dyeings were done at 20, 40, and 60°C. Ultrasound was effective in in creasing the uptakes of all four dyes on nylon 6 at these temperatures. The activation energies of the four dyes decreased with ultrasound. It is clear that ultrasound has an effect on the rate of dyeing on nylon 6.

Reflection electron-energy-loss spectroscopy, x-ray-absorption spectroscopy, and x-ray photoelectron spectroscopy studies of a new type of layer compound CrPS 4

Abstract: A new type of layer compound, ${\mathrm{CrPS}}_{4}$, has been investigated by means of reflection electron-energy-loss spectroscopy (REELS), x-ray-absorption spectroscopy (XAS), and x-ray photoelectron spectroscopy (XPS). Information on the bonding states of the compositional atoms and the occupied energy states has been deduced from the core- and valence-electron XPS results. The binding energies and the multiplet structures of core levels have been discussed in detail. Information on the unoccupied energy states has been deduced from the XAS results. On the basis of the REELS results, energy positions and the joint density of states have been discussed. The optical properties have been investigated through the Kramers-Kronig analysis of the REELS spectrum. We have made an attempt to derive the depth profile of the localized energy states from the incident-energy dependence. A schematic energy-band model has been proposed.

A Hybrid Experiment to Search for Beauty Particles

Abstract: We give here a detailed description of experiment WA75, which was performed at CERN to search for beauty particles. Events containing at least one muon with a high momentum transverse to the beam direction were selected; then the primary interactions and decay vertices, located in stacks of nuclear research emulsions, were examined and analysed. The various parts of the apparatus are described and the off-line analysis and search in emulsion are discussed. An estimate is made of the sensitivity of the experiment to beauty- and charmed-particle production.

Photosynthetic electron transport inhibition by phlorophenone derivatives

Abstract: The structure/activity relationships of phlorophenone derivatives including grandinol and homograndinol, which are potent inhibitors of photosynthetic electron transport (PET) in Eucalyptus grandis, were examined. The results indicate that at least one acyl functionality on a phloroglucinol nucleus was essential for PET inhibition, and that the lipophilicity and/or length of the acyl group was the most prominent factor affecting the activity. In addition, the introduction of a formyl group to monoacylphloroglucinols remarkably enhanced the activity. The structural requirements for PET inhibition in these compounds were found to be very similar but not identical with those for the phenol type of inhibitors proposed by Trebst et al.

Simultaneous determination of platinum(II), rhodium(III) and palladium(II) with 2-(5-bromo-2-pyridylazo)-5-(N-propyl-N-sulfopropylamino)phenol by high performance liquid chromatography

Abstract: Complexation postcolonne pour determination simultanee du platine, rhodium et palladium par chromatographie HPLC-phase inverse

An approach to Japanese-sign language translation system

Abstract: A method was developed for translating written (spoken) language (text in Japanese) into a sequence of sign words of Japanese sign language called Simultaneous Japanese Sign Language (SJSL). The Japanese-to-Sign translation system is described that uses a Japanese-to-Sign translation dictionary with about 250 signs. >

Determination of silver in seawater by graphite furnace atomic absorption spectrometry after solvent extraction and microscale back-extraction.

Abstract: A method is presented for the determination of silver in seawater by graphite furnace atomic absorption spectrometry after solvent extraction and microscale back-extraction. Silver is quantitatively extracted with 2× 10-4mol l-1 dithizone-benzene from seawater, and back-extracted with 100μl of nitric acid. The aqueous phase is taken by a fine glass tube; then a 10μl aliquot of the solution is injected into the graphite tube. This procedure has been applied to the determination of silver in coastal seawater.

Chaotic phenomena in four circuits with an ideal diode due to the change of the oscillation frequency

Abstract: Four simple chaos-generating circuits that include a diode are proposed for which both rigorous analyses and physical explanations of the generation of chaos are given. The idealized case in which the diode in the circuit operates as a simple on-off switching element is considered. In this case, the circuit equation is represented as an equation in which two linear second-order ordinary differential equations that have considerably different oscillation frequency are connected to each other by the switching operation of the diode. It is clarified that this effect causes a stretching and folding mechanism. Moreover, it is possible to derive a Poincare map strictly as a one-dimensional map that is similar to a logistic map, and it explains the generation of chaos. >

X-ray-absorption and -emission spectra of a K 2 PdCl 6 crystal studied by the self-consistent-charge extended Hückel method

Abstract: Molecular-orbital calculations are performed for an octahedral complex (${\mathrm{PdCl}}_{6}$${)}^{2\mathrm{\ensuremath{-}}}$ with a self-consistent-charge extended H\"uckel method and used to analyze experimental x-ray-absorption and -emission spectra for ${\mathrm{K}}_{2}$${\mathrm{PdCl}}_{6}$ crystals. Our calculations are entirely based on first principles in the sense that empirical atomic data are not used. The observed features for the x-ray-absorption and -emission spectra are shown to be generally accounted for by our calculations.

Extensive air showers accompanied by gamma -ray families with

Abstract: Extensive air showers (EAS's) accompanied by families of high-energy cascade showers were observed at Mt. Norikura (738 g ${\mathrm{cm}}^{\mathrm{\ensuremath{-}}2}$). 99 families of \ensuremath{\gamma}-ray- and hadron-origin showers with total energies J${E}_{\ensuremath{\gamma}}$,H\ensuremath{\ge}10 TeV were obtained. The success rate of the combination between families and EAS's reaches to almost 90% (87 events). The families are associated with young EAS's, with mean age parameter s\ensuremath{\sim}0.7, whose sizes distribute widely over three orders of magnitude up to ${10}^{8}$. The size spectrum of the family-associated EAS's coincides with the general EAS's in the size region above 5\ifmmode\times\else\texttimes\fi{}${10}^{6}$ but the former drops rapidly from the latter below this critical size. From the absolute intensity of J${E}_{\ensuremath{\gamma}}$,H spectrum the proton fraction in the primary cosmic rays is deduced to be (14\ifmmode\pm\else\textpm\fi{}5)%, with an error of one standard deviation, in the primary energies (5\ifmmode\times\else\texttimes\fi{}${10}^{14}$)\char21{}${10}^{16}$ eV, in comparison with a Monte Carlo simulation assuming an adequate interaction model. This agrees with the result obtained by the work with other mountain data and is also compatible with the result inferred from the size spectrum gap between the family-associated EAS's and the general EAS's in the region below the critical size.

Abundance of primary protons at (1-3)×10 15 eV inferred from a simulation of extensive air showers with γ-ray families

Abstract: A Monte Carlo simulation of extensive air showers (EAS's) was done under a particle-interaction model and was compared with the EAS's accompanied by \ensuremath{\gamma}-ray and hadronic families with total energy J${E}_{\ensuremath{\gamma}}$,H greater than 10 TeV obtained in the Mt. Norikura experiment (2780 m above sea level). The strong correlation between the shower size ${N}_{e}$ of EAS's with family and the primary energy, ${E}_{0}$, was obtained from the simulation as ${E}_{0}$/${N}_{e}$${=(2.0}_{\mathrm{\ensuremath{-}}0.7}^{+2.7}$) GeV with 95% width. The flux of the EAS's with family is sensitive to the chemical composition, especially to the fraction of protons in the primary cosmic-ray particles. The fraction of protons is inferred to be (20\ifmmode\pm\else\textpm\fi{}6)% and (23\ifmmode\pm\else\textpm\fi{}9)%, with one standard deviation (1\ensuremath{\sigma}), at energy (${1.4}_{\mathrm{\ensuremath{-}}0.5}^{+1.9}$)\ifmmode\times\else\texttimes\fi{}${10}^{15}$ eV and (${2.8}_{\mathrm{\ensuremath{-}}1.0}^{+3.8}$)\ifmmode\times\else\texttimes\fi{}${10}^{15}$ eV with 95% confidence interval, respectively, under the assumption of increasing cross section ${\ensuremath{\sigma}}_{p\mathrm{\ensuremath{-}}\mathrm{air}\mathrm{\ensuremath{\propto}}{E}^{0.055}}$ and approximate Feynman scaling in the fragmentation region. These values are in agreement with the values obtained from other mountain emulsion-chamber experiments within 2\ensuremath{\sigma}. The proton fraction thus obtained, around 20%, is much less than the normal abundance (\ensuremath{\sim}40%) expected from direct observations at lower energies around ${10}^{12}$ eV.

The Surface-treatment of Ceramic Powders Through Pulverization in a Reactive Atmosphere With a Ball Mill (1) The Surface-treatment of Quartz Powder

Abstract: The surface nature of quartz powder pulverized in a hexane solution of cetyl alcohol or octadecyltriethoxysilane by means of a ball mill was investigated. The original quartz powder showed itself to be hydrophilic since it dispersed in water as well in an immiscible mixed dispersive medium. While quartz pulverized in a hexane solution of cetyl alcohol was hydrophilic since it dispersed in water, for an immiscible mixed dispersive medium, guartz after pulverization for 8hrs. dispersed in water, but that after pulverization for 16hrs, or longer, dispersed in hexane. These pulverized quartz powders were much more hydrophobic than the original quartz powder. The quarts powder after pulverization in a hexane solution of octadecyltriethoxysilane showed that the one after pulverization for 24hrs, dispersed in water, while the one after pulverization for 32hrs., or longer floats on water. Therefore, these quartz powder were found to be hydrophobic, but for an immiscible mixed disperse medium, the ones after pulverization for 8hrs, or longer, dispersed in the hexane phase. The characteristic absorptions due to the surface group on the quartz powder after pulverization for 64hrs. were observed in the infrared adsorption spectra. The evolved vapors of the surface group were observed in their pyrolysis curves. The increase in carbon content was found to be accompanied with an increase in surface area due to pulverization. Accordingly, the quartz powder was found to be surface-treated effectively due to pulverization. The quartz powder pulverized in the hexane solution of cetyl alcohol was hydrophilic, more hydrophobic than the original quartz powder. This is due to the formation of the equilmol OH-group as that of the alcoxy-group.

VLA Polarization Observation of the Radio ARC at 15 GHZ

Abstract: Polarization measurements of the radio Arc were made with the VLA at 15 GHz. High frequency polarimetry made with high spatial resolution minimizes Faraday depolarization and reveals polarized filaments which correspond to the predominant filaments of the radio Arc. We notice a peculiar linear feature in the polarization map (“thorns”) which suggests the presence of a second magnetic field system. The total intensity maps show no evidence for an interaction between the two field systems, so the thorns may be foreground magnetized structures. However, if the two magnetic field systems do interact, it would allow a model in which the acceleration of relativistic particles takes place at their intersection. The accelerated particles would flow toward both ends of the radio Arc, and account for the intrinsic polarization observed along the entire length of the system. Thermal electrons responsible for the Faraday depolarization occuring at longer wavelengths may be supplied by the interaction of the streams of relativistic particles with relatively dense, ambient thermal clouds.

Photoconjugation of Methyl Linolenate in the Presence of Iodine as a Sensitizer

Abstract: In the previous paper, we reported the optimum conditions for the iodine-sensitized conjugation of methyl linoleate and its reaction mechanism.This paper discusses isomerization arising from irradiation with a 100W high-pressure mercury lamp using methyl linolenate with a 1, 4, 7-triene structure. Conjugated diene-trienoates and small amounts of conjugated trienoates are formed in this reaction. Slightly milder conditions than in methyl linoleate are suitable for the formation of conjugated diene-trienoates. The reaction conducted at room temperature using a sample with a concentration of 10 to 20% adding approximately 0.1% of iodine to a nonpolar solvent such as petroleum ether by irradiation for 46h is considered optimum. To obtain conjugated trienoates mainly, however, milder conditions such as no more than 0.03% iodine should be used. Under such conditions, the amounts of conjugated compounds were as much as about 70% (conjugated diene-trienoates 5562%; conjugated trienoates 815%) of the reaction products.This sensitized isomerization proceeds in the same way as indicated in the previous report and double bonds shift only in the direction of the conjugation.