scispace - formally typeset
Search or ask a question

Showing papers by "Utsunomiya University published in 1994"


Journal ArticleDOI
TL;DR: In this paper, a steel pile used for building foundations as a heat exchanger with the soil was used to predict variations in the water temperature and the quantity of heat exchanged with soil.

83 citations


Journal ArticleDOI
TL;DR: In this paper, the effects of each electrolytic condition on current efficiency, Vickers hardness, crystal structure and crystal morphology were studied with respect to the electrodeposited iron films obtained from iron(II) chloride solution.

58 citations


Journal ArticleDOI
TL;DR: In this article, the shape of π-A isotherms of a series of long-chain acids measured for a constant observation time at 10 °C changed systematically with changing chain length.

50 citations


Journal ArticleDOI
TL;DR: The findings suggest that the SCN is involved in the mechanism of blood glucose and body fluid intake as well as that of circadian rhythm.

48 citations


Journal ArticleDOI
TL;DR: In this paper, the corrosion of aluminum foil was inhibited in 0.1 − 10 wt% NaCl aqueous solutions in the presence of an external magnetic field, and the inhibition increased as the magnetic flux density was increased.

44 citations


Journal ArticleDOI
TL;DR: In this article, 3-dehydroteasterone, [2H6]typhasterol, and [ 2H6]-teasterone were fed to cultured cells of Catharanthus roseus.
Abstract: [2H6]3-Dehydroteasterone, [2H6]teasterone and [2H6]typhasterol were fed to cultured cells of Catharanthus roseus. As metabolites of [2H6]3-dehydroteasterone, [2H6]typhasterol (major) and [2H6]teasterone (minor) were identified by full-scan GC-MS. This result, together with the result of feeding teasterone and typhasterol, provides evidence for the possible involvement of 3-dehydroteasterone in the conversion of teasterone to typhasterol.

39 citations


Journal ArticleDOI
TL;DR: In this paper, a piecewise-linear second-order nonautonomous differential equation derived from a simple electronic circuit is shown to have a singular bifurcation into instant chaos.
Abstract: Strange bifurcation route to chaos is found in a piecewise-linear second-order nonautonomous differential equation derived from a simple electronic circuit. When a limit cycle loses its stability, the attractor changes directly to chaos (instant chaos) without undergoing a period doubling bifurcation or an intermittency. The width of the attractor's band is continuous at the bifurcation point, and the chaotic band grows larger continuously as the system parameter is varied. We call this bifurcation a singular bifurcation into instant chaos. The purpose of this paper is to show that the singular phenomenon arises from the piecewise-linearity of the system. To analyze this phenomenon in detail, the degenerate approach is applied. In this simplified case, the Poincare map is derived rigorously as a one-dimensional mapping. By analyzing it, we prove with computer assistance that the Liapunov exponent jumps discontinuously from minus to plus at the bifurcation point. >

31 citations


Journal ArticleDOI
TL;DR: In this paper, the electronic structure of graphitic tubules with general chirality is thoroughly studied by means of a recursion tight-binding method, and a detailed investigation of densities of states around the Fermi level for various types of tubules confirms the previous theoretical prediction that tubules become metals (M), narrow-gap semiconductors (NS's), or moderate-gap SVCs (MS's), depending on an integer index k specifying the geometrical structure of the tubules.
Abstract: The electronic structure of graphitic tubules with general chirality is thoroughly studied by means of a recursion tight-binding method. A detailed investigation of densities of states around the Fermi level for various types of tubules confirms the previous theoretical prediction that tubules become metals (M), narrow-gap semiconductors (NS's), or moderate-gap semiconductors (MS's), depending on an integer index k specifying the geometrical structure of the tubules. We point out that the MS's are systematically classified into two types, MS1 and MS2, according to this index. Namely, tubules correspond to M for k=0; otherwise they belong to semiconductors, being NS's, MS1, or MS2, respectively, for k modulo 3=0, 1, or 2. Our result is compared with an approximate expression for energy gaps of MS's, derived by White et al. and we discuss the deviation of our results from this expression. An empirical expression for the energy gap, which elucidates such a deviation, is suggested.

30 citations


Journal ArticleDOI
TL;DR: A monocyclic triterpene ester, iristectorene B, has been isolated from the seeds of Iris tectorum as discussed by the authors, which was shown to be 3-{3-hydroxy-2-[5-hydroxyl]-4,8,12- trimethyl-( 3E,7E )-3,7,11-tridecatrienyl]-2,3-dimethyl]-6-(1-methyl-2-oxoethylidene)cyclohexyl} propyl tetradecanoate

28 citations


Journal ArticleDOI
TL;DR: It is suggested that the variation in annual growth rate is dependent on food supply during the spring phytoplankton bloom which varies from year to year according to the flow of the cold Oyashio current each spring.
Abstract: Annual variation in the growth rate of the protobranch bivalve Yoldia notabilis (collected in Otsuchi Bay, northeastern Japan between 1989 and 1991) was determined by measuring shell length at successive growth lines. Factors affecting growth rates were assessed by examining long-term environmental data. Shell cross-sections of Y. notabilis showed a clear pattern of internal growth lines which formed simultaneously with the annual external lines on the outer shell surface. Hence, they were used as an age marker. A maximum lifespan of 17 yr was determined for this species, and a sigmoidal growth curve was obtained by the internal growth line analysis. Examination of the growth lines also revealed a large annual variation in growth rate, fluctuating as much as 32-fold during the past 9 yr. The variation correlated negatively with water temperature and positively with chlorophyll a content in the water column. It is suggested that the variation in annual growth rate is dependent on food supply during the spring phytoplankton bloom which varies from year to year according to the flow of the cold Oyashio current each spring.

28 citations


Journal ArticleDOI
TL;DR: In this article, a principle of the laser wakefield particle acceleration has been tested by the Nd : glass laser system with the peak power of 30 TW and the pulse duration of 1 ps.
Abstract: A principle of the laser wakefield particle acceleration has been tested by the Nd : glass laser system with the peak power of 30 TW and the pulse duration of 1 ps. The particle acceleration up to 18 MeV/c has been demonstrated by injecting 1.0 MeV/c electrons emitted from a solid target by an intense laser impact. The corresponding field gradient achieves 1.7 GeV/m.

Journal ArticleDOI
TL;DR: In this paper, a 5 l aeration tank containing a separation apparatus composed of a rotary magnetic disk and a scraper was prepared for sewage treatment, and a 100-d experiment was carried out using highly condensed activated sludge (7−12 g l −1 mixed-liquor volatile suspended solids) which is magnetized by adding magnetite powder, under the COD Cr loading rate of 0.81 g l−1 d −1 without withdrawal of excess sludge.

Journal ArticleDOI
TL;DR: In this article, the Sierpinski gasket and the ABC-gaskets are constructed as limits of random walks on one-dimensional chains and a limit theorem related to the discrete-time multi-type nonstationary branching processes is applied.
Abstract: Diffusion processes on the Sierpinski gasket and theabc-gaskets are constructed as limits of random walks. In terms of the associated renormalization group, the present method uses the inverse trajectories which converge to unstable fixed points corresponding to the random walks on one-dimensional chains. In particular, non-degenerate fixed points are unnecessary for the construction. A limit theorem related to the discrete-time multi-type non-stationary branching processes is applied.

Journal ArticleDOI
TL;DR: In this article, eight tetracyclic spirotriterpene derivatives, iristectorones A-H, have been found in the seeds of Iris tectorum.

Journal ArticleDOI
TL;DR: In this paper, heat generation due to eddy currents and hysteresis induced by alternating magnetic field was utilized for the enhancement of ethanol formation catalyzed by immobilized yeast.

Journal ArticleDOI
TL;DR: Six new triterpene esters, iristectorenes A and C-G, along with one known one have been found in the seeds of Iris tectorum, and they are established to be 3-3-hydroxy-2,3-dimethyl-6 and 1-methyl-2-oxoethylidene)-cyclohexyl.

Journal ArticleDOI
TL;DR: In this paper, benthic foraminiferal tests in 56 seafloor sediment samples (high tide to 45 m depth; slightly brackish to normal marine) in Port Pegasus, south-east Stewart Island, are analysed by cluster analysis.
Abstract: Census data on benthic foraminiferal tests in 56 seafloor sediment samples (high tide to 45 m depth; slightly brackish to normal marine) in Port Pegasus, south‐east Stewart Island, are analysed by cluster analysis. The faunal samples are grouped into six associations: A. Trifarina angulosa/Textularia proxispira/Miliolinella subrotundata—current‐swept passages and adjacent port; B. Notorotalia finlayi/Quinqueloculina delicatula/Nonionella flemingi—muddy fine sand at 22–30 m; C. Notorotalia zelandica/Elphidium novozealandicum—sheltered bays at 2.5–26 m; D. Rosalina bradyi—shallow subtidal amongst rocky reefs; E. Ammonia beccarii/Elphidium advenum depressulum/Haynesina depressula—0.5–6 m, sheltered bays and channels of Cooks Arm; F. Miliammina fusca—brackish, intertidal. In the entrance passages and exposed shelf (5–45 m depth) planktics comprise 15–30% of the total foraminiferal tests. Directly inside the passages in Port Pegasus, planktics comprise 30–65% of the fauna. These are dominated by small...

Journal ArticleDOI
TL;DR: In this article, a spatial walk-off polarizer that utilizes form-birefringence in an obliquely deposited thick film is proposed, composed of two substances, slant needle-like microcolumns and resultant fine voids around them.
Abstract: A spatial walk-off polarizer that utilizes form-birefringence in an obliquely deposited thick film is proposed. The film is composed of two substances, slant needle-like microcolumns and resultant fine voids around them. The structure has the uniaxial birefringence whose optic axis is parallel to the column/void axis. The basic operation was confirmed with tantalum-oxide thick films deposited onto beveled silica substrates. The spatial walk-off characteristic has clearly been observed, and the maximum polarization-split angle is measured to be 7.3/spl deg/, being larger than that of existing polarizers such as those made of rutile and calcite. >


Journal ArticleDOI
TL;DR: Two (-)-methoxybutanolides have been isolated from the rhizomes of Lindera glauca on the basis of spectroscopic methods and their structures were elucidated to be (3 S ,2 E )-2-(11-dodecenylidene)-3-Methoxy-4-methylenebutanolide and (3S,2 E)- 2-(11 - dodecynylidenes)-3 -meth oxygen

Book ChapterDOI
01 Jan 1994
TL;DR: For organizing the collaborating team, an efficient negotiation method with a learning mechanism based on histories of past negotiations is developed, and the method is evaluated by an implemented simulator.
Abstract: In this paper, an organization method for a collaborating team in a multi-agent robotic system is discussed. In order to realize a flexible and robust intelligent robotic system, we have been developing a distributed autonomous robotic system, ACTRESS, which is composed of multiple and heterogeneous robotic agents. In ACTRESS, every robotic agent aids other agents to achieve a common target, which cannot be carried out by a single agent. The agent requiring the collaboration organizes a collaborating team using communication, which consists of a leader agent (called coordinator) and some follower agents (called cooperators). For organizing the collaborating team, we developed an efficient negotiation method with a learning mechanism based on histories of past negotiations, and evaluated the method by an implemented simulator. Firstly, this paper presents teams and negotiation for organization in distributed autonomous robotic systems. Secondly, an organization strategy using negotiation with learning mechanism is discussed. Finally, the implementation and evaluation of this method are described, and experimental results are shown.

Proceedings ArticleDOI
08 May 1994
TL;DR: The architecture of the human interface system was designed so as to allow the operator to interact with the system through consistent interface in the real environment and in the simulator environment, in which robotic agents' programs are developed.
Abstract: The paper describes the human interface system in the autonomous and decentralized multi-agent robotic system ACTRESS. The human interface system coordinates the interaction between the human operator and robotic agents, monitors system's activities and presents them do the operator. The operator can send commands to individual robotic agents or a group of agents through the human interface. He can also intervene in the system based on monitored system status if and when necessary. The human interface also acts as a window through which the robotic agents contact the operator for judgment and advice. The paper presents the architecture of the human interface system. The architecture was designed so as to allow the operator to interact with the system through consistent interface in the real environment and in the simulator environment, in which robotic agents' programs are developed. >

Journal ArticleDOI
TL;DR: The p K d values of the chiral α-methylbenzyl or sec -butyl moieties were greater than those of the corresponding ( R )-isomers and paralleled the p I 50values of the PS II inhibition assay, and eudismic indexes decreased with increased activities.

Journal ArticleDOI
TL;DR: In this article, the authors measured the Cu Lα emission spectra in fluorescence from CuS and Cu 2 S with a two-crystal vacuum spectrometer equipped with beryl crystals.
Abstract: The Cu Lα emission spectra in fluorescence from CuS and Cu 2 S are measured with a two-crystal vacuum spectrometer equipped with beryl crystals The measured spectra are composed of a prominent peak and its high-energy structure They are compared with the S L 2,3 emission, S Kβ emission, Cu L 3 absorption and S K absorption spectra reported previously to obtain information about the electronic structures of the copper sulfides It is shown that the valence bands are composed of three parts: The upper part consists of the Cu 3 d states with considerable contribution of the S 3 p and 3 s characters, while the middle part consists of the S 3 p states with small contribution of the Cu 3 d and S 3 s characters and the lower part arises from the S 3 s states In addition, it is shown that the hybridization between the Cu 3 d and S 3 p or 4 p orbitals is fairly large in the lower part of the conduction band of CuS

Journal ArticleDOI
TL;DR: In this paper, a submerged filter system consisting of magnetically anisotropic tubular support media was investigated for wastewater treatment with a biofilm system, which was formed within 15 min on the magnetic support media by magnetic attraction.

Journal ArticleDOI
TL;DR: In this article, a non-linear large amplitude ion wave excitation by short microwave pulse at the resonance absorption region has been observed and the maximum amplitude of the wave is δn/n ≈ 40% in peak-to-peak, when a short microwave pulses of the order of or less than a period of ion oscillation (τi = 2π/ωpi) is used.
Abstract: Non-linear large amplitude ion wave excitation by short microwave pulse at the resonance absorption region has been observed. The maximum amplitude of the wave is δn/n ≈ 40% in peak-to-peak, when a short microwave pulse of the order of or less than a period of ion oscillation (τi = 2π/ωpi) is used. The excited wave propagates to lower density regions and its velocity is a function of its amplitude, v ∝ (δn/n0)2.2–2.7. At the same time, a strong electron wave is excited after shut-off of the incident microwave pulse and high energy electrons are emitted and accelerated by the excited electron wave wakefield.

Journal ArticleDOI
TL;DR: In this paper, the authors used a cross correlation method to detect the shear wave splitting and estimated the location and the cause of polarization in the southwestern part of Fukushima Prefecture, northeastern Japan.
Abstract: We have investigated shear wave polarization anisotropy in the southwestern part of Fukushima Prefecture, northeastern Japan. Waveform data we analyzed are obtained by a local seismic networks of Tohoku University and Utsunomiya University. We used a cross correlation method to detect the shear wave splitting. For the shallow events beneath the southwestern part of Fukushima Prefecture, observed that fast shear wave oscillation directions (FSODs) are oriented to the NW-SE. The observed delay times are less than 0.1 s and tend to have large values in high seismicity regions. For the intermediate-depth events, observed FSODs are oriented parallel to the dip direction of the subducted slab and most of the observed delay times are less than 1 s. We estimated the location and the cause of anisotropy based on these observations. In the upper crust beneath the southwestern part of Fukushima Prefecture anisotropy is estimated to be caused mainly by preferredly oriented cracks controlled by the tectonic stress.

Journal ArticleDOI
TL;DR: The chromatographic behavior of tris(2-methyl-8-quinolinolato)gallium and other tris (methyl-substituted 8-quinolineolato)-galliums was studied with a methanol-water mixture (80:20 v/v) containing 5×10-4mol dm-3 of the corresponding methyl-saturated 8-in-linol and 2× 10-3mol DMT of a hexamethylenetetramine buffer (pH 6.0) as mentioned in this paper.
Abstract: The chromatographic behavior of tris(2-methyl-8-quinolinolato)gallium and other tris(methyl-substituted 8-quinolinolato)galliums was studied with a methanol-water mixture (80:20 v/v) containing 5×10-4mol dm-3 of the corresponding methyl-substituted 8-quinolinol and 2×10-3mol dm-3 of a hexamethylenetetramine buffer (pH 6.0). The chromatographic behavior of tris(2-methyl-8-quinolinolato)gallium and tris(2, 5-dimethyl-8-quinolinolato)gallium changed when the column was varied. The other tris(methyl-substituted 8-quinolinolato)galliums did not change. Tris(2-methyl-8-quinolinolato)gallium and tris(2, 5-dimethyl-8-quinolinolato)gallium were dissociated by EDTA among all of the tris(methyl-substituted 8-quinolinolato)galliums studied. It was suggested that the chromatographic behavior of tris(2-methyl-8-quinolinolato)gallium was influenced by the chelate forming the interaction of the silanol group on the stationary phase.

Journal ArticleDOI
TL;DR: It is shown that the calculated results of the 4f levels relative to the Fermi level generally agree with the experimental ones obtained from the x-ray-photoemission spectroscopy experiments and bremsstrahlung isochromat spectra.
Abstract: The electronic structures of trivalent and divalent rare-earth hexaborides R${\mathrm{B}}_{6}$ are calculated by using the modified orthogonalized-plane-wave method within the framework of the muffin-tin-potential approximation based on the self-consistent-field atomic-structure calculations. By regarding the 4f state as a partially filled corelike state and for the transition between 4f and 5d states, and adopting the transition state introduced by Slater which includes the effect of the screening of 4f states by 5d electrons, an attempt is made to understand the x-ray-photoemission spectroscopy (XPS) experiments and bremsstrahlung isochromat spectra (BIS). It is shown that the calculated results of the 4f levels relative to the Fermi level generally agree with the experimental ones obtained from the XPS for ${\mathrm{CeB}}_{6}$, ${\mathrm{PrB}}_{6}$, ${\mathrm{NdB}}_{6}$, ${\mathrm{SmB}}_{6}$, ${\mathrm{GdB}}_{6}$, and ${\mathrm{YbB}}_{6}$ and the BIS for ${\mathrm{GdB}}_{6}$, ${\mathrm{TbB}}_{6}$, and ${\mathrm{DyB}}_{6}$, but there is a considerable difference between the calculations and experiments for the XPS for ${\mathrm{TbB}}_{6}$, ${\mathrm{DyB}}_{6}$, and ${\mathrm{HoB}}_{6}$ and the BIS for ${\mathrm{LaB}}_{6}$, ${\mathrm{CeB}}_{6}$, and ${\mathrm{PrB}}_{6}$. The reason for this disagreement is mainly attributed to the effect of 4f multiplets which is not taken into account in the present study.

Journal ArticleDOI
TL;DR: To reduce the scattering loss in LPS's, a multilayer with flat layer boundaries is fabricated with rf bias sputtering, and the insertion loss of the LPS is reduced to ~ 1 × 10(-3) dB/ µm, which is acceptable for practical uses.
Abstract: We experimentally found the unexpected phenomena of scattering in laminated polarization splitters (LPS’s) composed of a-Si:H-SiO2 multilayer and studied its mechanism. The scattering phenomena strongly depend on the incident angle and polarization of the incident light. To reduce the scattering loss in LPS’s, a multilayer with flat layer boundaries is fabricated with rf bias sputtering. As a result, the insertion loss of the LPS is reduced to ~ 1 × 10−3 dB/μm, which is acceptable for practical uses.