Quench detection of fast plasma events for the JT-60SA central solenoid

The JT-60 is planned to be modified to a full-superconducting tokamak referred to as the JT-60 Super Advanced (JT-60SA). The maximum temperature of the magnet during its quench might reach the temperature of higher than several hundreds Kelvin that will damage the superconducting magnet itself. The high precision quench detection system, therefore, is one of the key technologies in the superconducting magnet protection system.The pick-up coil method, which is using voltage taps to detect the normal voltage, is used for the quench detection of the JT-60SA superconducting magnet system. The disk-shaped pick-up coils are inserted in the central solenoid (CS) module to compensate the inductive voltage. In the previous study, the quench detection system requires a large number of pick-up coils. The reliability of quench detection system would be higher by simplifying the detection system such as reducing the number of pick-up coils. Simplifying the quench detection system is also important to reduce the total cost of the protection system. Hence the design method is improved by increasing optimizing parameters. The improved design method can reduce the number of pick-up coils without reducing the sensitivity of detection; consequently the protection system can be designed with higher reliability and lower cost. The applicability of the disk-shaped pick-up coil for quench detection system is evaluated by the two dimensional analysis. In the previous study, however, the analysis model only took into account the CS, EF (equilibrium field) coils and plasma. Therefore, applicability of the disk-shaped pick-up coil for the quench detection system remains open question because the fast plasma events, such as disruption, mini collapse and ELM (edge localized mode), directly influences on the voltage of pick-up coil making the quench signal undetectable. Consequently, a new analysis model proposed in the present paper was designed to avoid this difficulty by introducing the passive coil series such as vacuum vessel and stabilizer. The influence of fast plasma events is absorbed by passive coil series like real system, and the evaluation of applicability can be examined in detail. The analysis results show that the disk-shaped pick-up coil is applicable whenever the standard operation, disruption, mini collapse and ELM.     

Structural and Thermoelectric Properties of Chimney–Ladder Compounds in the Ru-Mn-Si System

We have investigated phase relationships of the sesquisilicide alloys in the Ru-Mn-Si system. A series of chimney–ladder phases Ru_1−x Mn _x Si _y (0.14 ≤ x ≤ 0.97, 1.584 ≤ y ≤ 1.741) are formed over a wide compositional range between Ru₂Si₃ and Mn₄Si₇. We also investigated thermoelectric properties of the directionally solidified Ru_1−x Mn _x Si _y alloys as a function of Mn content and temperature. The dimensionless figure of merit ZT for alloys with high Mn content (x ≥ 0.75) increases as the Mn content increases. The alloy with x = 0.90 exhibits ZT as high as 0.76 at 874 K.     

Precise control of sheet resistance in boron doping of silicon byexcimer laser irradiation

To control the sheet resistance in boron doping of silicon by the excimer laser irradiation, two-step doping consisting of the deposition of boron films and the incorporation of dopant atoms is proposed. These processes are carried out in the same chamber successively. Precise control of the sheet resistance can be realized by this method and a very low sheet resistance can also be obtained by only one pulse irradiation for the melting of silicon     

A product modeling system for constructing intelligent CAD and CAM systems

It is essential for the achievement of intelligent manufacturing systems to properly encode manufacturing knowledge in computer systems. We propose a product modeling system that is a framework for representing and utilizing models of both design objects and design tasks. The key concept in the framework is that of constraint. Several prototypical CAD/CAM applications constructed on the framework are shown.     

Aortic valve replacement through the transected aorta in a patient with aortic stenosis and a calcified ascending aorta

BACKGROUND: Uveitis associated with juvenile rheumatoid arthritis (JRA) is an important cause of visual impairment in children. Because uveitis is often asymptomatic in this age group, frequent ophthalmologic screening examinations are recommended. Recent reports have found a decrease in the prevalence and severity of uveitis in JRA when compared to older data. METHODS: The charts of 52 consecutive patients with JRA seen over a 30-month period were retrospectively reviewed. RESULTS: Eye examination identified uveitis in five (12%) patients. All patients with uveitis were female, ANA positive, and had pauciarticular-onset arthritis. Three patients had the onset of uveitis before the age of 2. All patients have maintained good visual acuity and have not developed serious sight-threatening ocular complications over the follow-up period. CONCLUSIONS: Although the prevalence and severity of JRA-associated uveitis may be decreasing, we strongly recommend continued strict adherence to the current screening guidelines.     

Endomorphins have orexigenic and anxiolytic activities in mice

This study was designed to investigate the effects of endomorphin 1 and 2, recently identified mu-opioid receptor selective peptides, on food intake and anxiety in non-food-deprived mice. The intracerebroventricular (i.c.v.) injection of either endomorphin 1 or 2 (0.03-30 nmol) increased food intake in a dose-related manner. A significant increase was observed 20 min after i.c.v. injection of endomorphin 1 or 2 and continued for 4 h. In the elevated plus maze test, the i.c.v. injection of endomorphin 1 (30 nmol) significantly decreased the normal preference for the closed arms. These results suggest that endomorphin produces orexigenic and anxiolytic effects, and that the mu-opioid receptor contributes to the regulation of feeding and anxiety in mice.