Showing papers by "Utsunomiya University published in 1993"

Light-propagation characteristics in thermally diffused expanded core fibers

Abstract: Characteristics of light propagation in thermally diffused expanded-core (TEC) fibers are analyzed. Changes in the modal-field distributions along fibers and transition losses are obtained by use of the propagating-beam method. It is found that a transition length sufficiently longer than the characteristic length is necessary to expand or reduce the field diameter with low losses. A simplified model for understanding the mechanism of light propagation in TEC fibers is presented. Transmission losses between TEC fibers having imperfect splices are measured, the results are compared with those obtained by a simple theory and an exact theory. >

Production of Two Single-Λ Hypernuclei by Ξ- Capture

Abstract: The S= −2 hypernuclear states formed through (K − , K + ) reactions have been studied by using the 1.66 GeV/c K − beam provided by KEK Proton Synchrotron. Investigation has been done on the stars due to the capture of the ξ − hyperons at rest in nuclear emulsion, which hyperons were produced in (K − , K + ) reactions. We observed a clear case of an absorption of ξ − hyperon at rest by a nucleus followed by a back-to-back emission of two single-Λ hypernuclei

Cosmic—Ray Deficit from the Directions of the moon and the Sun Detected with the Tibet Air Shower Array

Abstract: Data from the Tibet air-shower array were used to examine the cosmic-ray shadows of the Moon and the Sun at energies around 10 TeV. The shadowing effect was clearly observed at the $5.8\ensuremath{\sigma}$ level for the Moon, while the shadow of the Sun was found in the direction away from the Sun by 0.86\ifmmode^\circ\else\textdegree\fi{} to the west and 0.43\ifmmode^\circ\else\textdegree\fi{} to the south. The effect of the geomagnetic field has also been observed in the shadow of cosmic rays by the Moon. The observed deflection of the Sun's shadow is briefly discussed in connection with the effect of the magnetic fields between the Sun and the Earth. This is the first observation of the effects of such magnetic fields on the cosmic-ray shadow. The maximum-likelihood analysis of the Moon data set shows that the angular resolutions of the array for showers with its mode energies 7 and 35 TeV are 0.87${\mathrm{\ifmmode^\circ\else\textdegree\fi{}}}_{\ensuremath{-}0.10\mathrm{\ifmmode^\circ\else\textdegree\fi{}}}^{+0.13\mathrm{\ifmmode^\circ\else\textdegree\fi{}}}$ and 0.54${\mathrm{\ifmmode^\circ\else\textdegree\fi{}}}_{\ensuremath{-}0.08\mathrm{\ifmmode^\circ\else\textdegree\fi{}}}^{+0.11\mathrm{\ifmmode^\circ\else\textdegree\fi{}}}$, respectively.

Export of Soluble Sugars and Increase in Membrane Permeability of Gladiolus Florets during Senescence

Abstract: Export of soluble sugar, changes in all membrane permeability, and production rate of ethylene in the perianths of the lower florets on the gladiolus spikes were determined as related to physiological events affecting the wilting of perianths after they were fully unfolded.1. Perianths appeared to be wilting between 2 and 3 days after unfolding fully (DAU). Concurrent with the onset of wilting, perianths rapidly decreased in fresh and dry weights.2. Between 1 and 2 DAU, one day before perianths started to wilt, total soluble sugar contents began to decrease. Between 2 and 3 DAU, the largest loss of total soluble sugars occurred, most of which was possibly due to export from perianths to other parts.Concurrent with the export of sugars, an increase in leakage of ions from perianth tissues was observed.3. Rates in ethylene production of perianths did not show a significant change in relation to the time of wilting.Depletion of sugars was discussed as related to the disintegration of membranes, which could cause perianths to wilt.

Direct Evidence of the Interplanetary Magnetic Field Effect on the Cosmic-Ray Shadow by the Sun

Abstract: The Tibet air-shower array, being successively operated at an altitude of 4300 m above sea level since 1990, has detected the shadows of the Sun and Moon in the 10 TeV cosmic-ray flux. In particular, the shadow of the Sun was observed in the direction significantly away from the apparent solar position, under the influence of the solar and interplanetary magnetic fields. A further analysis shows that the shadows by cosmic rays coming from the away and toward field sectors in the interplanetary space are shifted in opposite directions to one another according to the polarity of the fields. This is the first direct observation of the influence of the interplanetary magnetic field on the shadow's displacement

Raman and Infrared Spectra of Misfit Layer Compounds MNbS3 (M=Sn, Pb, La, Ce)

Abstract: Raman scattering and infrared reflection spectra of misfit layer compounds MNbS3 (M=Sn, Pb, La, Ce) have been measured to study the interlayer interaction and the charge transfer from the MS layer to the NbS2 layer. Analysis of the Raman spectra indicates that the interlayer interaction is considerably stronger for the La and Ce compounds than for the Sn and Pb compounds, which may be related to the difference in the amount of the charge transfer.

Core-electron spectra and electronic structure of CeNbS3.

Abstract: Core-electron-spectroscopy studies have been made for CeNbS 3 , which is one of the misfit-layer compounds. The Ce 3d and 4d x-ray photoemission (XPS) spectra are quite similar to those in CeSe. Ce exists mainly as a trivalent ion and the 4f electrons hybridize with other conduction and valence electrons. The S 2p XPS spectrum exhibits only a broad peak which consists of plural spin-orbit-split structures at different chemical environments. We find some evidence which indicates interlayer interaction and electron transfer from the Ce 5d band to the Nb d z 2 band. The Nb n 2,3 inner-shell-electron energy-loss spectrum exhibits a small peak just above the threshold, indicating that the d z 2 band is still incompletely filled after charge transfer

Analyses of Developmental Ability of (BALB/c*C57BL/6) F1 and ICR Mouse Embryos Fertilized In Vitro and Their Chromosome at the First Cleavage Division.

Abstract: Superovulated eggs in (BALB/c×C57BL/6) F1 and ICR (outbred in a closed colony) female mice were fertilized in vitro with spermatozoa obtained from caudal epididymides of ICR males. Air-dried chromosome preparations were made from colcemid-primed 1-cell eggs and stained by the C-banding method. The fertilization rate was lower in F1 eggs than in ICR eggs (88 vs. 92%, P<0.02). The incidence of metaphase ("syngamy") eggs was higher in F1 eggs, and the incidence of pronuclear and late prometaphase ("pre-syngamy") eggs was higher in ICR eggs (P<0.001, P<0.005), showing delayed progress of the first cleavage in the ICR eggs. Developmental rates from 2-cell to 4-cell stage and from morula to blastocyst stage were significantly lower in ICR eggs (P<0.001) than in F1 eggs. These results show that a delay of embryo development had already appeared before male and female genomes fused (pre-syngamy). The incidence of triploidy, which might be caused by dispermy, was higher in F1 eggs, in both the pronuclear and mitotic stages (P<0.001). A little aneuploidy and structural aberration of chromosomes occurred in both F1 and ICR eggs, and no significant difference was observed between F1 and ICR eggs. The sex ratio at the first cleavage stage in both F1 and ICR eggs showed no significant deviation from equality.

Construction of a new shuttle vector pSTE33 and its stabilities in Bacillus stearothermophilus, bacillus subtilis, and Escherichia coli

Abstract: A shuttle vector that could replicate in B. stearothermophilus, B. subtilis, and E. coli was constructed from B. stearothermophilus cryptic plasmid pSTK1, E. coli vector pUC19, and a thermostable kanamycin-resistance marker. This new vector was stably maintained in B. stearothermophilus at 67°C without selective pressure.

Stability and Antimicrobial Property of 4-Methylthio-3-butenyl Isothiocyanate, the Pungent Principle in Radish

Abstract: Stability of 4-methylthio-3-butenyl isothiocyanate (MTBI) was studied in an aqueous medium. Most of (E)-MTBI was degraded within 3h by shaking or sonicating and within 6h on an agar plate. (Z)MTBI was more stable. Antimicrobial activity of MTBI on 8 bacteria, 3 yeasts, and 5 fungi was estimated in a gaseous phase. The growth of fungi were strongly inhibited by MTBI in the dose range 2.5-7.5 μmol/ plate. The fact that the maximum amount of MTBI in head space was only 0.2% of the dose suggested that the antimicrobial activity of MTBI was very high.

Self-avoiding Paths on the Three Dimensional Sierpinski Gasket

Abstract: We study self-avoiding paths on the three-dimensional pre-Sierpinski gasket. We prove the existence of the limit distribution of the scaled path length, the exponent for the mean square displacement, and the continuum limit. We also prove that the continuum-limit process is a self-avoiding process on the three-dimensional Sierpinski gasket, and that a path almost surely has infinitely fine creases.

Antimicrobial activity of water-soluble products derived from radish mustard oil and identification of an active component therein

Abstract: Antimicrobial property of water-soluble products obtained by degradation of 4-methylthio-3-butenyl isothiocyanate, the pungent principle of radish, was studied using 5 Gramnegative and 5 Gram-positive bacteria, 5 yeasts, and 9 fungi. Two antimicrobial components were found in the water-soluble products, of which the major one was isolated and indentified to be 2-thioxo-3-pyrrolidinecarbaldehyde on the bases of UV, MS, 1H-NMR and 13C-NMR spectral data. The identified compound exhibited a prominent growth-inhibition on the fungi and Gram-positive bacteria. The inhibitory effect on the yeasts and Gramnegative bacteria except for Escherichia coli was the least among the tested microorganisms.

Interaction between optical isomerism and plant pharmacological action, change of modes of action and chirality of 1-(α-methylbenzyl)-3-p-tolylurea†

Abstract: The optical isomers, (R)-1(α-methylbenzyl)-3-p-tolylurea ((R)-MBU) and (S)-1-(α-methylbenzyl)-3-p-tolylurea ((S)MBU), which are analogues of daimuron [1-(α,α-dimethylbenzyl)-3-p-tolylurea], a herbicide for Cyperaceae weeds and a safener for paddy rice, exhibited different biological responses. These two physiological properties of daimuron were observed separately in (R)-MBU and (S)-MBU. Only (R)-MBU had herbicidal activity against Cyperaceae weeds, while the (S)-isomer was a more effective safener against bensulfuron-methyl (BSM) injury of rice seedlings than was (R)-MBU. (S)-MBU promoted root growth of rice seedlings, but the (R)-enantiomer inhibited root growth. (S)-MBU was a more potent inhibitor than (R)-MBU on PS II reaction of spinach broken chloroplasts. Furthermore, (S)-MBU and (R)-MBU showed cross intergenus selective phytotoxicity among the Gramineae plants, Oryza sativa L. (rice, cv. Tsukinohikari, japonica), Triticum aestivum L. (wheat, cv. Norin No. 61) and Echinochloa crusgalli var. frumentacea Wight, on root growth inhibition in the dark.

Computer simulation of grain growth in three dimensions

Abstract: A Monte Carlo computer simulation has been carried out to study the kinetics of grain growth and the grain size distribution in three dimensions. The model employed is superimposed onto a fcc lattice, which has the least anisotropy among conceivable ones. The temporal evolution of the microstructure during normal grain growth is monitored for both the cross-section and the model itself to investigate the change in grain size distribution. The simulated results indicate the change in the distribution form of grain size during grain growth. Furthermore, it is found that the microstructural evolution including the change depends on the dimension in measurement and the temperature.

Synthesis of Five-membered Heterocycles by Reactions of N-Substituted-2-aminomethyloxiranes with Heterocumulenes

Abstract: Various five-membered heterocyclic compounds were synthesized by the reactions of N-substituted-2-aminomethyloxiranes with several different heterocumulenes in good yields.

Wakefield accelerator using twin linacs

Abstract: A collinear wakefield test facility using two linacs with a common test section is described. Beams from one linac excite wakefields in a test medium s

Simple and rapid screening method for photosystem II inhibitory herbicides using photoautotrophically cultured plant cells with chlorophyll fluorescence monitoring

Abstract: The photosystem II inhibitory activity of substituted phenylurea derivatives in liverwort photoautotrophically cultured cells was determined by monitoring chlorophyll fluorescence. Since the inhibitory activities in this assay correlated well with both the Hill inhibitory activity in isolated thylakoids and the herbicidal activity against mung bean plants, this bioassay may be a suitable screening method for photosystem II inhibitory herbicides.

Resonance characteristics of whispering gallery modes on a dielectric disk

Abstract: Resonance and loss characteristics of whispering gallery modes in a dielectric disk resonator are discussed three-dimensionally by using an approximate variable separation method. A radius of the disk is sufficiently large compared to a wavelength. A cylindrical function with a complex order and argument whose absolute values are much larger than unity is included in an eigenvalue equation. In this paper, the eigenvalue equation is solved analytically by using a newly developed calculation method of the cylindrical function. As a result, resonance and loss characteristics of the dielectric disk resonator in a wide frequency ranging from a microwave to optical wave are understood. The present method can be applied to a whispering gallery mode resonator made of lossy dielectric materials. Therefore, one can obtain a radiation loss separately from a dielectric loss based on a loss tangent of the materials.

Dynamic Measurement of Clothing Pressure on the Body in a Brassiere

Abstract: In this study, the pressure of a brassiere on the body was measured statically and dynamically. The static pressure in a standing position was large at the shoulder, the side and the back. In the other positions the ratio of static brassiere pressure in each position to the standing position was large at the shoulder and the back. By dynamic measurement, two main peaks of brassiere pressure were observed at the shoulder and the back while performing a motion. Larger brassiere pressure was observed at the shoulder, the side and the back by the dynamic measurement than by the static measurement. The brassiere pressure and observed changes were small at the cup of the brassiere. In comparing the results of the dynamic measurements, the brassiere pressure of a certain position was found to be different when a different motion was perfomed in the same position. It is necessary to measure the clothing pressure on the body dynamically in order to properly evaluate comfortable clothing.