Bacillus polymyxa L-1129 produced a new peptide antibiotic complex, named LI-Fs, composed of more than ten components. In this reports we will describes the isolation, structure elucidation and biological activity of each components, LI-F03a, LI-F03b, LI-F04a, Li-F04b, LI-F05a, LI-F05b, LI-F06a, LI-, LI-F07a, LIF07b, LIF08a and LIF08b. These antibiotics were active against gram positive bacteria, mycobacteria and wide range of fungi and yeast, but not for gram negative bacteria. The antibiotic complex LI-Fs (400mg) was isolated from 10 liters fermentation broth using several kind of column chromatography. HPLC analysis showed that the complex was composed of at least 12 components. The components were isolated by HPLC, and the structures of each components were determined by 1D and 2D NMR and MS spectra coupled with amino acid analyses to be hexadepsipeptide containing 15-guanidino-3-hydroxypentadecanoic acid as side chain. The structure of LI-F05a was identified to be a cyclohexadepsipeptide [L-thr(1)-D-val(2)-L-Ile(3)-D-allo Thr(4)-D-Asn(5)-D-Ala(6)] and LI-F05b was identified as an isomer of LI-F05a that was replaced the Asn residue in LI-F05b with Gln, similar pairs were also found in other components, (LI-F06a-LI-, LI-F07a-LI-F07b, LI-F08a-LI-F08b) (Fig. 4). Four amino acids; L-Thr(1); D-Ala(6); D-Asn(5) or D-Gln(5); D-allo Thr(4) and one side chain were commonly found in the LI-Fs antibiotics. Thus, these moieties seems to be fundamental for biological activity of LI-Fs antibiotics.

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This paper discusses on the minimum energy maneuver of a satellite using two reaction wheels. The problem is a rest-to-rest maneuver around the axis, which is perpendicular to each wheel axes. The attitude of satellite is described using the parameters that are presented by Tsiotras et al. The parameters are useful for the description of maneuvers by two wheels. The relation between the optimal maneuver and the moment of inertia is shown analytically and numerically. The results show that the symmetry satellite whose all moments of inertia are same does not have a unique optimal solution. A group of minimum energy trajectories exists. On the other hand, the asymmetry satellite has a unique optimal solution. The numerical solutions show that the wheel on the axis of smaller moment of inertia consumes more energy than the other wheel.

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A preliminary life test of a low-power DC arcjet anode was conducted using a 500-W-class laboratory-model arcjet. After a continuous operation of 90-h, we compared the degradation of two types of anodes: one is a conventional pure tungsten anode, which is made of multiple fine grains of several tens of micrometer in size; another is a tungsten anode made of only four coarse grains. Both materials showed nearly the same amount of degradation from the viewpoint of so-called a constrictor closure phenomenon, in which the radius of the constrictor decreases during the continuous operation. However, micrograph analyses showed different degradation features for the two anodes: for the conventional tungsten anode, grains were severely embrittled in the recrystalization processes after the thruster operation accompanied by many cracks or even drops out of grains; in contrast, the anode made of four coarse grains showed a few cracks only along the grain boundaries, and its thrust performance was unchanged before and after the 90-h test. Hence there is a possibility to suppress the grain embrittlement by completely removing these grain boundaries from the tungsten anode by making the anode from one huge grain.

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A two-stage magnetic field with cusp and divergent shapes was applied in a magneto-plasma-dynamic (MPD) thruster discharge chamber. The thrust efficiency intensively increased with enhanced thrust and unchanged discharge voltage because of more effective ionization/heating and swirl acceleration due to the applied magnetic field. When the magnetic field became much stronger and the arc current became much higher, the thrust approached the self-magnetic thrust. As a result, an optimum magnetic field strength existed. The plasma flow was observed by a high-speed camera, and plasma density, temperature and velocity were measured with electrostatic probes. Through the magnetic nozzle the exhausted plasma rotated and spreaded radially-outward, and the plasma density decreased near the central axis. Accordingly, the plasma characteristics agreed with the measured thrust performance, considering intensive plasma heating due to Hall current and swirl acceleration, i.e. conversion from azimuthal kinetic energy to axial kinetic energy.

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This paper describes the torque characteristics of surface-mounted-PM motor with concentrated stator winding. The torque is analyzed in detail by 2D FEM, and the proposed segmented PM motor is very useful to reduce the cogging torque. The simulation results by FEM are presented together with the considerably reduced rotor iron structure.

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The paper reports design process of a space boom to be installed in a 50kg-class micro-satellite, tentatively called as SOHLA-1. The total mass of the boom is 483g, while the length of the boom is 416mm. A spring-string type pin-puller was proposed. Vibration test with a bread-board model (BBM) of the boom leaded to an engineering model (EM) of the boom accommodated with a two-pin type pin-puller. Vibration test with the boom EM suggested some modifications to be made for a proto-type model (PM) of the boom. Vibration test, deployment test and thermal test on the boom PM confirmed feasibility of the flight model (FM) of the boom.

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We investigated the genetic diversity of the core collection of hexaploid wheat accessions in the Japanese wheat gene bank, NBRP-Wheat, with a focus on grain morphology. We scanned images of grains in the core collection, which consists of 189 accessions of Triticum aestivum, T. spelta, T. compactum, T. sphaerococcum, T. macha and T. vavilovii. From the scanned images, we recorded six metric characters (area size, perimeter length, grain length, grain width, length to width ratio and circularity) using the software package SmartGrain ver. 1.2. Statistical analyses of the collected data along with hundred-grain weight revealed that T. aestivum has the largest diversity in grain morphology. Principal component analysis of these seven characters demonstrated that two principal components (PC_core1 and PC_core2) explain more than 96% of the variation in the core collection accessions. The correlation coefficients between the principal components and characters indicate that PC_core1 is related to grain size and PC_core2 to grain shape. From a genome-wide association study, we found a total of 15 significant marker-trait associations (MTAs) for grain morphological characters. More interestingly, we found mutually exclusive MTAs for PC_core1 and PC_core2 on 18 and 13 chromosomes, respectively. The results suggest that grain morphology in hexaploid wheat is determined by two factors, grain size and grain shape, which are under the control of multiple genetic loci.

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An experimental study on aerodynamic effect of RLVs (Reusable Launch Vehicles) due to fuselage cross sections has been conducted in subsonic flow. Three fuselage models and two wing-body models have been considered. Fuselage models have a circular, a square and a triangular cross section. Wing-body models have a square and a triangular cross section with wings. Experiments have been conducted under test conditions of free-stream Mach number M_∞=0.3 and Reynolds number Re=3.2×10⁶. Aerodynamic forces are measured and flow fields are visualized by smoke-wire technique and oil-flow technique. Results show that fuselage cross sections have much effect on whole aerodynamic characteristics, the fuselage model with a triangular cross section has higher lift coefficient in high angle of attack region than that of the other fuselage models and the wing-body model with a triangular fuselage cross section does not stall till high angle of attack region compared with the “Square” fuselage wing-body model.

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Ignition tests of methane fuel under supersonic air streams were conducted with the methane/oxygen combustion jets as an ignition source. The ignition capability of the combustion jets differed with their equivalence ratio φ; ignition at Mach 2 was successful at 2.4kW calorific input power with φ=0.3 jets while 6.5kW power was needed at stoichiometry (φ=1.0). Numerical calculations revealed the relative effectiveness on shortening the ignition delay times for methane/air mixture between active radicals such as H, O, and OH and ordinary oxygen gas O₂ abundantly contained in the lean combustion jets. These results overall suggest that ignition by the methane/oxygen combustion jets has an advantage in simplicity from the practical viewpoint over the plasma jet method which needs a heavy electrical power source.

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Numerical prediction of the reservoir temperature in a shock tunnel is performed by simulating the unsteady flow field in the driven tube and nozzle of the shock tunnel of Nagoya University. The axisymmetric, compressible Navier-Stokes equations are numerically solved by a finite volume code with the third order MUSCL in space and the fourth order Runge-Kutta method in time. The results show that the flow pattern near the end of the driven tube is highly complicated, because the reflected shock wave interacts with the boundary layer and contact discontinuity. The present simulation estimates the reservoir temperature of the shock tunnel at a maximum value of 876K, which agrees with the value predicted from the heat flux experimentally measured at a model in the test section.

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We developed a method, which is called the multi nodes technique, that can take into account of the any electrical isolation of conductors using the multi nodes of the electric scalar potentials. The eddy currents in the laminated silicon steel sheets can be calculated using this method without the mesh of the interlaminar air gap. It is quantitatively clarified that the eddy currents in the laminated silicon steel sheets in a permanent magnet-type MRI system have effects on the time variations of the flux distributions.

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This paper studies penetration depth and wave propagation in multi-layer ground. A relation between a wave propagation domain frequency, penetration dpeth and multi-layer ground parameters is estimated. An experimental setup is constructed to study the transient characteristics of spherical grounding electrode embedded into ground. The ground is analysed as homogenous ground, two-layer ground and multi-layer ground. To verify the proposed equations, a spherical grounding electrode is tested by injecting a step like current of different rise times into the spherical grounding electrode at different depths. The injected currents and voltages are measured and analysed. The electrode impedance shows dependence on the injected domain frequency and depth of the spherical grounding electrode at different ground layers. Numerical model is proposed by using the current source simulation method and the method of successive image technique. This model is used to investigate the penetration depth effects on grounding spherical electrode resistance in homogenous and two-layer ground. The experimental results verify the proposed estimated penetration depth equations.

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Stable electrolyte cathode atmospheric dc glow microdischarges were generated by using a miniature helium gas flow from a nozzle electrode in air. We developed two schemes to control the temporal evolution of the discharge and the interaction between the discharge column and the ambient air. The vaporization of electrolyte solutions takes place and affects the discharge characteristics. It takes time from the start of the discharge. Therefore the discharge was controlled by applying pulse modulated dc voltages. If the voltage was dropped down to zero before the vaporization, the gas discharge developed without the ionization of the components of solution. The helium gas discharge without air developed when the nozzle electrode was placed in a glass capillary. This was confirmed by examining the change in pH of the solution, which usually decreased owing to the generation of nitrogen oxides in the discharge in air.

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This paper investigates frequency-dependent parameters of a counterpoise which are identified from measured voltages and currents by a numerical optimization technique. Based on the investigation, the frequency characteristics of the impedance and the admittance are made clear. Then, Sunde's formulas of the frequency-dependent impedance and admittance, which are not widely used because of requiring iterative calculations to determine the final values, are compared with the measured results. It appears that Sunde's iterative formulas show a similar trend to the frequency-dependent parameters identified from the measured results, and can be adopted in a frequency lower than 100kHz. However above the frequency, the formula is case sensitive and is not reliable.

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Numerical investigation of the rolling moment control of a delta wing using a micro-flap in supersonic flow is performed in the present study. So far, several experiments and CFD analyses regarding the micro-flap in subsonic flow have been reported, and the location of a leading edge separation vortex and its size are found to play a key role in producing the rolling moment. On the other hand, in supersonic flow, the mechanism of rolling moment generation is found to be different from that in subsonic flow. The leading edge separation vortex is not so much affected by micro-flap installation. However, a large pressure change behind the micro-flap is observed, which causes the rolling moment of the delta wing. Moreover, the rolling moment in the supersonic flow is generated only in one direction, unlike the subsonic flow, where it is produced in either direction.

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Genetic Network Programming (GNP) has been proposed as a new method of evolutionary computations and its basic characteristics are studied. GNP is constructed using graph structures whose gene consists of directed graphs, so it is possible to search solutions effectively especially for the dynamic real world problems due to the implicit memory function of its structure. Also GNP can easily implement a priori knowledge into its structure as functional nodes. There has been no example where GNP is applied to real world systems until now. In this paper, Elevator Group Supervisory Control System (EGSCS) which is a typical real world system is studied using GNP. From the simulations, the availability of GNP to EGSCS is confirmed and it is clarified that the proposed method can show better performances than other conventional methods.

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The present paper has investigated the effect of sheath grounding on a control cable based on EMTP simulations, when a lightning current flows into counterpoises representing a part of a grounding mesh. Voltages and currents observed on the control cable are given as a superposition of an well-known induced voltage due to the lightning current on the counterpoise, of a voltage transferred from the counterpoise to which the cable metalic sheath is grounded, and of a lightning current circulating in a closed loop composed of the metalic sheath and the counterpoise when the cable both ends are grounded. The induced voltage from the counterpoise is not necessarily dominant even in a long cable because the current along the counterpoise decreases rapidly as the distance from the sending end increases. Although the sheath grounding decreases the node voltage due to the induced voltage, but at the same time increases a voltage transferred from the counterpoise. The inductance of a grounding lead reduces a current flowing into the cable sheath during a high frequency transient, and thus a more current flows through the counterpoise. This results in a higher induced voltage to the control cable from the counterpoise.

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Supersonic flow fields around Two-Stage-To-Orbit (TSTO) models with different configurations have been experimentally examined in this paper. Four configurations for the orbiter have been considered: A) a hemisphere-cylinder, B) a hemisphere-cylinder with a flat bottom, C) an obliquely truncated circular cylinder, and D) a cone-cylinder. All the flow fields around these models showed complicated shock/shock and shock/boundary-layer interactions, which can be categorized into three patterns, depending on the extent to which the separation shock wave contributes to these interactions. The models B, C and D were proposed to suppress the pressure rise due to the interactions observed in the model A. As a result, the model B showed almost the same interactions as the model A, while in the model C they did not present. In the model D, a large pressure rise was seen in the case with no clearance, whereas the model undergoes the least aerodynamic interaction at a rather large clearance. It is concluded from these results that the model C is less affected by aerodynamic interactions due to the clearance than the other models.

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A computational program using a CFD-CSD coupled method has been developed to study the problem of low supersonic curved panel flutter. So far the supersonic aerodynamic model has been commonly employed to compute flutter boundaries. However, the present CFD-CSD coupled method makes it possible to analyze flutter boundaries at all speeds including transonic speeds. The computed flutter dynamic pressure for M_∞=3 agrees with others’ results. A curved panel flutter were analyzed at a low supersonic speed, M_∞=1.2. The flutter for small curvature panels is first-mode flutter, which is similar to flat panel flutter, whereas it becomes higher-mode flutter for larger curvature plates. In this study, flutter boundaries for an access panel have also been simulated. Its critical dynamic pressure becomes significantly lower compared with the case of a panel with its all edges simply supported.

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