Phase Diagram for a Portion of the System Li2O-Nd2O3-P2O5

In the ternary system Li₂O-Nd₂O₃-P₂0₅, part of the phase diagram relevant to the growth of single LindP₄O₁₂ (LNP) crystals was examined. LNP melts incongruently and decomposes into NdP₃O₉ and liquid at the peritectic temperature of 970°C. For the crystal growth, an Li₂O-P₂O₅ mixture should be used as a flux. The melt compositions from which LNP nucleates were clarified.     

Microparticulation by Jet Mill Grinding of Protein Powders and Effects on Hydrophobicity

A method was studied for microparticulation of protein for use as fat substitutes by superfine grinding. A jet mill produced particles <3 μm from egg white, casein and soybean hull. Microparticulation by grinding of egg white was easier than with casein or soybean hull. Hydrophobicity of casein increased by grinding to super fine particles but little or no effect was observed on soybean hull and egg white.     

FLUX DISTRIBUTION AND REACTANCE IN ENCLOSED SLOT SOLID ROTOR INDUCTION MOTOR

ABSTRACT

In this paper flux distribution by finite element method in the solid rotor with enclosed slot induction motor compared with the flux distribution in the laminate core rotor with enclosed slot is examined.

This paper also presents a method of deriving the reactance from the magnetic energy stored at the portion of the rotor surface. The method of calculating the reactance of the slot tip of an induction motor with enclosed slots is examined. The starting performance calculation of this motor are also described.

Explanation is made here in the order as follows: Equivalent circuit of enclosed slot solid rotor induction motor, Flux distribution in the solid rotor with enclosed slots, Method of deriving the reactance from stored and accumulated magnetic energy, Calculation of the flux distribution, Examples of calculations on the reactance of the slot tip, Results of calculation and measurement on characteristics of the tested motor.

The method of deriving the reactance from the magnetic energy stored in the surface region of the core is considered to be utilizable widely in the technology of magnetic circuits involving non-linear magnetic characteristics     

SURFACE LOSS REDUCTION IN GROOVED SOLID POLES

ABSTRACT

Surface loss due to higher harmonic magnetic flux in solid pole synchronous motor is generally quite significant. This loss is present in both synchronous and solid rotor induction motors. Grooving may be adopted as a method to reduce the surface loss of the solid pole. As the presence of the grooves on solid poles causes a part of the eddy current which is considered as an end effect problem, strictly theoretical solution of the problem is extremely difficult. In this paper loss equation of two layer rotor construction and approximate equation of the loss equation are analyzed.

If the depth of the groove is small compared with the depth of harmonic flux penetration, the part of the solid pole surface is considered partly to be the two layer rotor construction. Measured value of surface loss of grooved solid rotor is described and studied by considering the end effect. Correction cofficient k_r1, about the end effect is obtained by the experiment. The surface loss reduction factor is also obtained. This grooving technique is used for the solid pole synchronous motor and for the claw pole machine.     

Development of High‐Power Density Interleaved dc/dc Converter with SiC Devices

We developed an interleaved dc/dc converter with SiC devices. We applied full‐SiC modules including MOSFETs and SBDs to the interleaved dc/dc converter to achieve a high‐power density. An SiC has a high temperature resistance, which facilitates an improvement in high‐frequency drives. We achieved a high‐power density by utilizing this high temperature resistance. We also fabricated a prototype and tested it with loads up to 65 kW.     

表面波等离子体暴露下铜表面的氧化特性

Surface wave plasma(SWP) is a kind of low temperature plasma which can be utilized for material development.In this research,argon and oxygen were used as a working gas for an SWP experiment and the influence of the plasma irradiation on a copper surface was examined.Particular,relation between the spatial characteristics of SWP and wetting characteristics was examined.As a result,it was found that spatial characteristics of the SWP affected the wetting characteristics and the oxidation characteristics.     

High Density Plasma Heating by EC-Waves Injected from the High-Field Side for Mode Conversion to Electron Bernstein Waves in LHD

To realize an excitation of electron Bernstein waves (EBW) via mode conversion from X-mode waves injected from the high magnetic field side (HFS), new inner-vessel mirrors were installed close to a helical coil in the large helical device (LHD). 77 GHz electron cyclotron (EC) wave beams injected from an existing EC-wave injection system toward the new mirror are reflected on the mirror so that the beams are injected to plasmas from HFS. Evident increases in the electron temperature at the plasma core region and the plasma stored energy were observed by the HFS beam injection to the plasmas with the line-average electron density of 7.5×10 19 m 3 , which is slightly higher than the plasma cut-off density of 77 GHz EC-waves, 7.35×10 19 m 3 . The heating efficiency evaluated from the changes in the time derivative of the plasma stored energy reached ～70%. Although so far it is not clear which is the main cause of the heating effect, the mode-converted EBW or the X-mode wave itself injected from the HFS, an effective heating of high-density plasma over the plasma cut-off of EC-wave was successfully demonstrated.     

Proposal and Feasibility Study of the Integrated Diode Synchronous Motor

This paper presents a new type of magnet‐free motor that has concentrated stator windings and rotor coils with a pair of diodes. The most important feature of this motor is that currents in the rotor coils can be generated by utilizing the changes in the spatial second harmonic of the magnetic fields due to the concentrated stator windings, which normally increase motor losses. A prototype of the motor was designed and fabricated, and its basic performance was evaluated. First, using simplified analytic models, we explain the mechanism of inducing currents in the rotor coils by the changes in the spatial second harmonic of the magnetic fields. Second, we compare the torque performance of the proposed motor and that of other types of motors including a magnet motor through finite‐element analyses. The analyzed data show that the proposed motor can possess greater torque/volume ratio than that of the other motors. Finally, using the measured data, we validate the mechanism of inducing currents in the rotor coils, and examine the torque and power characteristics of the motor.     

Imperfect debugging models with fault introduction rate for software reliability assessment

In general it is considered to be unrealistic in software reliability modelling to assume that the faults detected by software testing are perfectly removed without introducing new faults. In this paper we propose two software reliability assessment models with imperfect debugging by assuming that new faults are sometimes introduced when the faults originally latent in a software system are corrected and removed during the testing phase. It is assumed that the fault detection rate is proportional to the sum of the numbers of faults remaining originally in the system and faults introduced by imperfect debugging. These two models are described by a nonhomogeneous Poisson process. Several quantitative measures for reliability assessment are derived, and the maximum likelihood estimations of unknown model parameters are presented. Finally, numerical examples of software reliability analysis based on these two models are shown.