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The basic learning of electromagnetic induction is to understand the relationship between the magnitude and direction of the induced electromotive force by changing the magnetic flux, but this cannot be visually grasped as a phenomenon. This is the reason why it is difficult for students to understand the concept of electromagnetic induction. It is required to develop an experimental kit that allows students to understand visually and quantitatively through experiments. In this work, we developed an “induced electromotive force experiment kit” for high school students and taught high school students about electromagnetic induction experiments using this kit. In this report, we outline the experiment kit and our project class of high school/university connection.

The basic learning of electromagnetic induction is to understand the relationship between the magnitude and direction of the induced electromotive force by changing the magnetic flux, but this cannot be visually grasped as a phenomenon. This is the reason why it is difficult for students to understand the concept of electromagnetic induction. It is required to develop an experimental kit that allows students to understand visually and quantitatively through experiments. In this work, we developed an “induced electromotive force experiment kit” for high school students and taught high school students about electromagnetic induction experiments using this kit. In this report, we outline the experiment kit and our project class of high school/university connection.

Magnetic flux coordinates are constructed from an analytic solution (Ito and Nakajima 2009 Plasma Phys. Control. Fusion 51 035007) for the reduced magnetohydrodynamics (MHD) equilibrium equations for high-beta tokamaks in the presence of poloidal and toroidal flows comparable to the poloidal sound velocity. The analytic solution indicates non-circular magnetic flux surfaces and transition between sub- and super-sonic poloidal flows. The magnetic flux coordinates for such non-circular magnetic flux surfaces are obtained for stability analysis. The flux coordinates are numerically obtained from the high order polynomial equations for the relation with the geometrical coordinates. As applications, pressure profiles in the poloidal direction on each flux surface, which become non-constant due to flow, and the flux average of the pressure are obtained. The transitions of the pressure profiles and the flux average of the pressure between sub- and super-sonic poloidal flows are discussed in relation with the radial force balance. The flux coordinates are also obtained analytically by expanding the coordinate relations with respect to the inverse aspect ratio.

A low-power-consumption Magneto-Rheological (MR) fluid damper has been designed and fabricated to suppress the vibration of a space flexible structure. The MR damper fabricated in this study has advantages of both semi-active and optimal passive dampers, unlike the conventional MR and Electro-Rheological (ER) fluid semi-active damper. The vibration is thus damped quickly when the damper is controlled semi-actively, and the vibration energy is dissipated by an optimal passive damper in the absence of control. To implement the aforementioned damper, fabricated was an electromagnet combined with a permanent magnet. Its performance and the characteristics of the damper with the newly developed electromagnet were subsequently measured. The performance of the damper has been confirmed by vibration suppression experiments using 10-bay truss structures., 資料番号: AA0048057005, レポート番号: JAXA-RM-04-010

The present study describes that time-Varying (50 Hz) magnetic field of 1 mT to the pregnant mice has teratogenic effects on the developing embryos. Fetuses were continuously exposed with alternation magnetic field in utero from 7.5 to 18.5 days of pregnancy. Mice were autopsied on 18.5 days of pregnancy. Control mice received sham exposure with the same schedule as that of exposed. The mouse was sacrificed by overdose ether anesthesia and the fetuses were removed for morphological observation. The skeleton of fetuses was doubly stained with alcian blue and arizarin red S. The specimens were observed under a stereomicroscope. Various malformations were observed in 50 percent of exposed fetuses. The exposure group had anomalies including polydactylism, abdominal fissure, trace of 13th rib, lumbar rib and curled tail., 資料番号: AA0047275029

資料番号: AA0045426057

資料番号: AA0045426055

The speed-torque characteristic and the commutation characteristic are mainly depend on the magnetic flux in armature airgap. In this paper, the numerical solution method to analyse the magnetic flux is proposed. Next, The magnetic fluxes in small-sized DC machine with armature wave-winding are derived from the proposed method. The magnetic fluxes in commutating zones, which are disturbed by commutating current of armature coil, are investigated. The results may be used to improve the both characteristics of DC machine.

Magnetic-field-controlled chemical wave traveling of Co (2) complex-hydrogen peroxide system was examined under micro-gravity. The wave traveling depended on the gradient of the magnetic flux density. The undisturbed wave front was observed to quantitatively analyze the magnetic-field-dependence of the traveling., 資料番号: AA0063706047