Suggestions for Safe Motorchair Football.

本研究は電動車椅子サッカーの岡山県における活動状況を把握し，このスポーツを安全に行う方法について検討することを目的とした。対象は脊髄損傷(A群)，脳性麻痺(B群)，筋ジストロフイー(C群)の選手各々4名， 5名および4名の計13名で，平成13年8月24日から平成13年12月23日までに行なわれた計8日の練習および試合をビデオカメラを用いて撮影し分析した。平成13年12月14日までの練習状況から電動車椅子同士の衝突により生じるスピン，身体接触，電動車椅子の浮揚の危険な衝突に着目し，平成13年12月23日に行なわれた3試合，計120分のなかで危険な衝突に関して分析を行った。その結果， A群では 危険な衝突が19回， BおよびC群でも計19回みられた。それらの内，衝突後の防御姿勢の有無に関してA群は認められた回数が17回，認められなかった回数が2回であった。B群およびC群では，認められた回数がl回，認められなかった回数が18回であった。A群とB・C群間での防御姿勢の有無に関する差異は有意(x2検定， p < 0.01) であった。以上より障害種別によるクラス分けの必要性が明らかになった。さらにヘルメットやプロテクターの着用の重要性に関しての指摘も行い，指導員の養成の必要性についても考察した

Synthesis of single-phase L10-FeNi magnet powder by nitrogen insertion and topotactic extraction

Tetrataenite (L10-FeNi) is a promising candidate for use as a permanent magnet free of rare-earth elements because of its favorable properties. In this study, single-phase L10-FeNi powder with a high degree of order was synthesized through a new method, nitrogen insertion and topotactic extraction (NITE). In the method, FeNiN, which has the same ordered arrangement as L10-FeNi, is formed by nitriding A1-FeNi powder with ammonia gas. Subsequently, FeNiN is denitrided by topotactic reaction to derive single-phase L10-FeNi with an order parameter of 0.71. The transformation of disordered-phase FeNi into the L10 phase increased the coercive force from 14.5 kA/m to 142 kA/m. The proposed method not only significantly accelerates the development of magnets using L10-FeNi but also offers a new synthesis route to obtain ordered alloys in non-equilibrium states

A study on the time-matching in three dimensional cinematography

本研究の目的は,同期しているデータと同期上の誤差を含んだデータの解析結果を比較し,民生用ビデオの定量的動作解析への利用の可能性を検討することであった。フレームカウンターを接続した2台のビデオカメラにより,バレーボールのスパイク動作を撮影した。2台のカメラの2次元座標が同期している場合,No.1カメラとNo.2カメラの2次元座標の時刻が1/120秒ずれている場合,No.1カメラとNo.2カメラの2次元座標の時刻が1/60秒ずれている場合の3通りの同期誤差をもつ2次元座標を準備し,DLT法により身体各部位及びボールの3次元座標を算出した。スティックピクチャーによる視覚的比較,各種測定項目による数値的比較を通して,同期,同期誤差1/2field,同期誤差1fieldのデータ間に大差が見られなかったこと,そして大部分の測定項目の値は先行研究の値の範囲にあったことから,民生用ビデオによる3次元動作解析は可能であると考えられた。The purpose of this study was to compare the analysis results of Time-Matching with Time-Error data and to find the possible utilization for quantitative motion analysis by home videos.It took spiking motions of volleyball by two video cameras with frame counter. After prepared three cases of two-dimensional coordinates that the time of two cameras are matching, different of 1/120 and 1/60 seconds, three-dimensional coordinates of the segment endpoints and a ball were calculated by Direct Linear Transformation Method.There were no great difference in Time-Matching, 1/2 and 1field data through the visual comparison by stick-pictures and the numerically comparison by various kinds of items of measurement. Consequently, the results suggest that it is possible to do three dimensional motion analysis by home videos

Large negative uniaxial magnetic anisotropy in highly distorted Co-ferrite thin films

The strain induced magnetic anisotropy (MA) of epitaxial Co-ferrite (CFO) thin films grown on MgAl2O4(001) (MAO) by reactive sputtering was studied. These films underwent large tetragonal compressive strain due to the lattice mismatch between the substrates and films, resulting in tetragonalities of up to −0.04. Scanning transmission electron microscopy observation combined with fast Fourier transform analysis revealed that the lattice distortion monotonically relaxed with the increasing film thickness. Unlike the CFO(001) films on MgO(001) substrates, a magnetically enhanced layer exists at the interface between CFO and MAO. A large negative uniaxial MA energy of −5.9 MJ/m3 was confirmed for the thinnest film of 12.9 nm at 300 K by magneto-torque measurements. The induced uniaxial anisotropy decreased with the increasing film thickness owing to misfit relaxation. The magneto-elastic (ME) constant, which was determined by a fitting line for films with different thicknesses and therefore different tetragonalities, was 0.15±0.01 GJ/m3. This result is consistent with the value of 0.14 GJ/m3 for the bulk and suggests that the framework of the phenomenological ME theory for CFO is valid for a wide range of tetragonalities, at least up to −0.04. Our results also indicate that the misfit engineering of CFO thin films has great potential in inducing enhanced uniaxial MA

Spin Hall magnetoresistance at the interface between platinum and cobalt ferrite thin films with large magnetic anisotropy

The recently discovered spin Hall magnetoresistance (SMR) effect is a useful means to obtain information on the magnetization process at the interface between a nonmagnetic metal and ferromagnetic insulators. We report the SMR measurements at the interface between platinum and cobalt ferrite thin films for samples with two different preferential directions of magnetization (out-of-plane and in-plane). The directional difference of the magnetic easy axis does not seem to influence the value of SMR

Effects of time and environmental conditions on the quality of DNA extracted from fecal samples for genotyping of wild deer in a warm temperate broad-leaved forest

Extraction of DNA from non-invasive samples (feces) has been used increasingly in genetic research on wildlife. For effective and reliable genetic analyses, knowledge about which samples should be selected in the field is essential. For this reason, we examined the process of DNA degradation in feces of deer. We collected fresh fecal pellets from three wild deer living in a warm temperate forest. We then assessed the effects of time (3, 5, and 10 days) under three environmental conditions (on the forest floor, on exposed ground, and inside the laboratory) on the rates of correct genotyping (CG), amplification failure (NA), genotyping error among positive amplification (ER), false alleles (FA), and allelic dropout (AD) of 15 microsatellite loci. The rate of CG significantly decreased, and those of NA and FA increased with increasing lapse of time. Rates of CG tended to be highest and those of NA, ER, FA, and AD to be lowest in feces kept inside, followed by those on the forest floor. Suitability of samples for DNA extraction was lowest in fecal pellets left on exposed ground, and we suspect that rain may hasten DNA degradation. NA rate could serve as a reliable indicator of the quality of fecal pellets because it was significantly positively correlated with ER rate. For efficient genetic analyses using deer feces in warm temperate zones, we recommend collecting fecal pellets within 3 days of defecation, during periods without rainfall and from under the cover of trees