High Power Neutral Beam Injection in LHD

The results on high power injection with the ueutral bean, injection （NBI） system for the Large Helical Device （LHD） are reported. The system consists of three beam-lines with two hydrogen negative ion （H^- ion） sources installed in each beam-line. In order to improve the injection power, a new beam accelerator with a multi-slot grounded grid （MSGG） has been developed and applied to one beam-line. Using the accelerator, a maximum power of 5.7 MW was achieved in 2003 and 2004, and the maximum energy of 189 keV was reached. The power and energy exceeded the design values of the individual beam-line for LHD. The other beam-lines also increased their injection power up to about 4 MW, and the total injection power of 13.1 MW was achieved with three beam-llnes in 2003. Although the accelerator had an advantage in high power beam injection, extracted beams expand in the short side direction of the ground-grid slot. The disadvantage has been resolved by modifying the aperture shapes of the steering grid.     

Photoluminescence of layered perovskite oxides with triple- octahedra slabs containing titanium and niobium

Abstracts are not published in this journal This revised version was published online in November 2006 with corrections to the Cover Date.     

使用直线电动机之电火花加工性能

介绍了日本沙迪克公司开发的采用直线电动机的电火花成形加工机的高灵敏度响应和高速抬刀性能,并与旋转电动机方式进行了对比试验。结果表明,直线电动机方式定位控制精度高、抬刀速度快、排屑效果好,能更有效防止发生短路,因而能提高加工速度和加工效率。     

Application of the Integrated Diode Synchronous Motor to Traction Drive Motors

In this study, a traction drive electric motor was designed with a new magnet‐free motor design technique where electromagnets are generated on a rotor by utilizing changes in the spatial second harmonic of the magnetic fields. To apply the proposed technique to electric motor design, balancing the rotor and stator magnetomotive force is important. This paper presents design methods for adjusting the rotor and stator magnetomotive forces. A test motor was designed with these design methods and evaluated using a motor bench. The analytical and measurement data indicated that the proposed motor performed comparably to magnet motors.     

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.     

Dielectric Recovery Characteristics after High‐Frequency Current Interruption in Vacuum Circuit Breaker

When the contacts of circuit breaker are opened just before current zero, the gap between contacts will still be very short. Therefore, it cannot withstand recovery voltage between the contacts. In such a case, multiple reignition is likely to take place. Many investigators had tried to clarify this phenomenon, and many reports have been published. However, high‐frequency current interruption and dielectric recovery characteristics are related to some parameters (value of current, arc time, and so on). In addition, arc phenomenon has also been implicated. Hence, it is difficult to understand this phenomenon accurately. In this paper, we conducted dielectric recovery test and high‐frequency current interruption test. Further, we conducted observation experiment using vacuum chamber in order to investigate the effect of small dc current. At the end, we calculated plasma density in the electrodes after high‐frequency current interruption by considering the result of observation experiment and dielectric recovery test.     

放射防护体系的演进

建立在线性无阈假设上的现行辐射防护体系对工作人员和公众成员所受剂量的最小化具有很大的贡献。然而,因为线性无阈意味着不管剂量多么小辐射总是有害的,所以已经引起人们的“辐射恐惧”并因过度审管而造成资源的浪费。作者重温了辐射健康效应的研究结果,包括对辐射工作人员的重大流行病学研究。发现在低于目前最大剂量限值(工作人员：50 mSv／y,公众成员：5 mSv／y)的辐射照射情形下没有明显的有害健康效应的证据,而二十世纪后半叶这些限值在全世界被广泛采用。既然DNA修复、细胞凋亡、适应性反等生物防预机理的存在得到了公认,那么线性假设就不能说成是“科学的”。越来越多的证据表明存在着辐射危险的阈效应。为了解决低剂量问题。在新的放射防护体系中应当引入“实际的”阈值或“事实上的安全剂量”概念。“实际的”阈值可定义为某一剂量水平,低于此剂量水平就不会诱发可观察到的放射所致的癌症或遗传效应。除了医疗目的有意照射以外,如果工作人员和公众成员从受照中得不到利益,则辐射照射应当保持在“实际的”阈值之下。假设目前的剂量限值低于“实际的”阈值且没有“辐射损害”,那么对于职业照射和公众照射就不需要“正当性”和“最优化(ALARA)”原则。这样一来,允许以对社会的利益抵销对个人的辐射损害的“正当性”伦理学问题也就能够得到解决。而且,用健康和安全换取经济利益的“最优化”的伦理问题也可以得到解决。只有通过引入“实际的”阈值概念的方法才能使辐射防护体系建立在面向个人的理念上,并且满足21世纪伦理学的平等原则。     

Sugar and Cyclitol Determination in Vegetables by HPLC Using Postcolumn Fluorescent Derivatization

Nonreducing sugars such as sucrose, raffinose, myo-inositol, pinitol and galactinol were separated on a polyamine-bonded polymer gel (NH₂ type) column using acetonitrile-water as mobile phase. Sugars in the eluate were detected by periodate oxidation and the subsequent derivation of guanidine to fluorescent compounds. Detection limits were: sucrose 2.5, D-glucose 2.5 and pinitol 4 ng. This highly sensitive method was more accurate and rapid for determining sugar contents in immature soybean seeds, sweet corn kernels and chinese mustard leaves than the conventional method using refractive index detection. Also, this method reduced the injection volumes of extracts to the column and allowed to lengthen the column life.     

HYPOTENSIVE ACTIVITY OF MUSCLE PROTEIN AND GLUTEN HYDROLYSATES OBTAINED BY PROTEASE TREATMENT

Protein hydrolysates obtained by treatment with papain, trypsin, chymotrypsin and actinase all exhibited inhibitory activity (IC50: 3.4–41.8 mg%) toward angiotensin‐converting enzyme (ACE) (EC 3.4.15.1). In particular, the protein hydrolysate obtained by treatment with papain showed the highest inhibitory activity (3.7–5.3 mg%). The ACE inhibitory activity of the gluten hydrolysate obtained with actinase was mainly due to peptides of less than 500 Da in molecular mass. On the other hand, the ACE inhibitory activity of the myofibrillar protein hydrolysate obtained with papain was due to peptides of both less and more than 500 Da in molecular mass. The blood pressure of spontaneously hypertensive rats (SHR) administered the myofibrillar protein hydrolysate was significantly reduced at 2 h after administration. The blood pressure of SHR was also reduced at 2 h after administration of the gluten hydrolysate, and this effect continued until 6 h. These hydrolysates may potentially be useful as antihypertensive food materials.     

The Circuit Analysis and Performance Evaluation of an Hc Type Magnetic Coupling Contactless Power Transformer that is Compatible with Both Solenoid and Circular Type Transformers

There are two types of the transformers in a contactless power transfer system: solenoid type (H‐shaped) and circular type transformers. These two types of transformers are not compatible because their magnetic field structures are different. An Hc type transformer that is compatible with both transformer types has been proposed. The Hc type receiver adds a central magnetic pole by dividing the winding coil of the H‐shaped receiver. The Hc type receiver can change the magnetic field structure by changing the connections of the divided windings and can receive power from both types of transmitters. In this study, we conducted a circuit analysis and evaluated the performance of the Hc type transformer.