An X-ray CT apparatus is provided with an X-ray tube current modulation pattern calculation means that calculates an X-ray tube current modulation pattern based on a 3-dimensional model of an object calculated based on a scanogram image of the object, start-up shape acquisition means that acquires a start-up shape of CT values of a predetermined region of the object or CT value time differences after injecting contrast agent into the object, time contrast curve prediction means that predicts a time contrast curve indicative of a time sequential change of contrast in a diagnostic portion of the object at each slice position at a scan time based on the acquired start-up shape of the CT values or CT value time differences, object 3-dimensional model modification means that modifies a 3-dimensional model of the object based on the predicted time contrast curve, and X-ray tube electric current modulation pattern modification means that modifies the X-ray tube electric current modulation pattern based on the modified 3-dimensional model of the object.

X-ray CT apparatus

An electric power-steering device has a speed-reducing mechanism (17) for reducing the speed of an output shaft (16) of an electric motor (15). The speed-reducing mechanism (17) has an internal gear (39) engaged and rotated with the output shaft (16) and an external gear (40) with which the internal gear (39) internally meshes. A drive pulley (41) rotatable together with the external gear (40) and a driven pulley (42) provided so as to surround a steering shaft are connected by an endless belt (43). Speed reduction is obtained by the internal gear (39) and the external gear (40), and the speed-reducing mechanism (17) as a whole achieves a high reduction ratio without greatly reducing the diameter of the drive pulley (41).

Electric power-steering device

The composition of worldwide energy consumption is undergoing tremendous changes due to the consumption of non-renewable fossil energy and emerging global warming issues. Renewable energy is now the focus of energy development to replace traditional fossil energy. Energy storage system (ESS) is playing a vital role in power system operations for smoothing the intermittency of renewable energy generation and enhancing the system stability. We divide ESS technologies into five categories, mainly covering their development history, performance characteristics, and advanced materials. Biomass storage and gas storage are also discussed, which are not considered in most reviews. After detailed research, the rapid development of each technology in recent years is introduced, and some representative research works are surveyed. We comprehensively summarized the advantages and disadvantages of various ESS technologies and presented several evaluation indicators for quantitative analysis. Hybrid ESS is also considered based on the complex market demand. Then, we investigate the applications of various ESS technologies as short-term, medium-term, and long-term storages in power systems, covering the power generation, transmission and distribution, and end-user. Finally, this paper reviews global developing trends, and identifies critical challenges and promising opportunities.

A review of technologies and applications on versatile energy storage systems

The magnet/dielectric composites with tunable structure and composition have drawn much attention because of their particular merits in magnetoelectric properties compared with the sole dielectric or magnetic composites. In addition, porous materials at the nanoscale can satisfy the growing requirements in many industries. Therefore, constructing porous metal alloy/carbon nanocomposites is to be an admirable option. Unfortunately, traditional synthesis methods involve multistep routes and complicated insert-and-remove templates approaches. Here we report a facile process to synthesize CoxNiy/C composites via a spontaneous cross-linking reaction and subsequent calcination process, during which multiple processes, including reducing polyvalent metal ions, forming alloy, and encapsulating alloy nanoparticles into porous carbon matrix, are achieved almost simultaneously. By adjusting the feed ratio of Co2+ to Ni2+ ions, controllable composition of CoxNiy/C composites can be gained. It should be noted that the...

Cross-linking-derived Synthesis of Porous CoxNiy/C Nanocomposites for Excellent Electromagnetic Behaviors

An electric power steering apparatus has a steering mechanism SM having universal joints 4, 6 in a torque transmitting system, a steering toque detecting unit 14, a steering angle detecting, unit 18, a torque fluctuation detecting unit 43 for detecting a torque fluctuation due to the crossing angle α in the universal joints 4, 6 on the basis of the steering angle θ detected by the steering angle detecting unit 18 and any one of the steering torque T detected by the steering torque detecting unit, a current command value It and self-aligning torque SAT; and a current command value correcting unit 44 for correcting the current command value on the basis of the torque fluctuation detected by the torque fluctuation detecting unit 43 and the steering angle θ detected by the steering angle detecting unit 18.

Electric Power Steering Apparatus

The superconducting magnet is effective to get a high stable and high magnetic field for magnetic resonance imaging (MRI). The current MRI superconducting magnet needed cooling in the liquid helium (4.2 K) to use NbTi superconducting wire. In the past few years, price increase and low availability of liquid helium has become a serious problem. Under such circumstances, the development of a high-temperature superconducting (HTS) coil dispensing with liquid helium cooling is greatly desired. The research and development project of the high stable magnetic field ReBCO coil system fundamental technology that started from the latter half of 2013 develops a ReBCO coil for 3 T MRI superconducting magnets. It gets a prospect of the practical use as the final aim. In this project, we will produce an HTS test coil of 300 mm bore experimentally and evaluate the magnetic field. This coil is cooled in less than 20 K by a GM refrigerator. We are going to make MRI used by the ReBCO coil field to evaluate the uniformity and stability of the magnetic field.

Research and Development of the High Stable Magnetic Field ReBCO Coil System Fundamental Technology for MRI

This paper investigates a method to increase fuel economy of motors for an electric vehicle (EV) traction system. The low-torque region of an EV motor is frequently used in everyday urban driving and in fuel economy measurement. Pulsewidth modulation (PWM) carrier harmonic iron loss accounts for a high percentage of total loss for EV motors in this region. This paper reveals the relationship between phase current and carrier harmonic iron loss for a permanent-magnet synchronous motor (PMSM) in the low-torque region. Thus, a novel carrier harmonic loss reduction technique is proposed and applied to two sets of three-phase windings for a concentrated winding PMSM. The loss is successfully reduced in a 70-kW EV motor as well as a two-dimensional finite-element method (2-D-FEM) calculation. The efficiency of the developed motor is calculated and compared with that of a conventional motor in the JC08 mode driving cycle.

PWM Carrier Harmonic Iron Loss Reduction Technique of Permanent-Magnet Motors for Electric Vehicles

PROBLEM TO BE SOLVED: To obtain a stator for a rotating electric machine, capable of suppressing torque ripples without degrading the characteristics of the stator SOLUTION: In the stator for a rotating electric machine wherein a magnetic pole section is formed at each tip of a plurality of magnetic pole teeth facing the rotor and arranged in the direction of the periphery of a yoke at specified intervals, a plurality of plate-shaped magnetic members 12, each of which has a different width in the direction of periphery of each magnetic pole section 12d, 12e, are laminated, and the width of an opening between the adjoining magnetic pole sections 12d, 12e is made larger than specified at every point in the direction of the axis COPYRIGHT: (C)2002,JPO

Stator for rotating electric machine

The present invention provides a dynamo-electric machine that suppresses vibrations caused by imbalance due to electromagnetic forces and that also suppresses imbalance in magnetic attraction forces generated owing to the difference in the number of coil portions among electric circuit portions. This dynamo-electric machine comprises an armature having a winding consisting of a plurality of coil portions each formed by lap-winding a conductor between a corresponding pair of slots formed in an outer circumferential surface portion of a core fixed to a shaft in such a way as to extend in an axial direction thereof, a commutator fixed to an end portion of the shaft and having a plurality of segments to which both end sections of said coil portions are electrically connected, brushes made to respectively abut against the surfaces of the segments of the commutator, and equalizers for connecting said segments, which are to be at equal electric potential, to each other. Moreover, the coil portions are parallel-connected to one another between the segments, and disposed in such a manner as to be symmetrical with respect to a mechanical angle of 360 degrees.

Electric rotating machine

A motor embedded with magnets having good properties and productivity. A rotor of this motor includes a rotor core with laminated rotor core plates punched out of an electromagnetic steel plate and studded with bonded magnets of a powdered permanent magnet material and a resin in groups of slits located in the rotor core for each pole of the rotor.

Akihiro Daikoku

Papers

Research and Development of the High Stable Magnetic Field ReBCO Coil System Fundamental Technology for MRI

PWM Carrier Harmonic Iron Loss Reduction Technique of Permanent-Magnet Motors for Electric Vehicles

Stator for rotating electric machine

Electric rotating machine

Motor and motor rotor having embedded permanent magnets