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An emulsion was prepared using corn fibre gum (CFG) and the resulting oil and aqueous phases were separated by centrifugation. The material adsorbed onto the surface of the oil droplets in the oil phase was desorbed using surfactant. The desorbed CFG and the non adsorbed CFG that remained present in the aqueous phase were collected, precipitated using alcohol and freeze dried. Their sugar composition, phenolic acid, lipid and protein contents were determined. There was no consistent difference observed in the sugar composition, phenolic acid and lipid contents of the original material and the adsorbed and non adsorbed fractions. There was, however, a significant difference in the protein contents with the adsorbed fraction containing ~10.7% protein compared to 3.90% and 2.87% for the original and non adsorbed CFG samples respectively. The three samples were also found to have very similar molecular mass distributions and each showed the presence of two peaks using refractive index detection. The major peak, corresponding to ~95% of the total, had a molecular mass of ~ 650,000 g/mol and the minor peak corresponded to a molecular mass of ~ 90,000 g/mol. The corresponding UV elution profiles indicated that the minor peak contained a significant proportion of phenolic and/or proteinaceous material.

Accepted: 2000-03-22, 資料番号: SA1002548000

A magnetic cloud embedded in a corotating interaction region was observed by WIND 244 Re upstream of Earth on May 13, 1995. This cloud was unusual since it had at least two internal structures and the profile of the magnetic field strength did not conform to a simple force-free flux rope model, though the field direction fitted well. About 90 min later, it was detected by IMP 8 and GEOTAIL in front of Earth's bow shock. GEOTAIL observed a sunward movement of the bow shock 8 min after the passage of the front boundary. From the normal vector of the bow shock front, we deduce that the shape of the expanding bow shock was distorted from an axially symmetric geometry. The shape was consistent with distortion due to the observed inclination of the front boundary of the magnetic cloud.

Observations of the Geotail spacecraft show that ion flow oscillations in the Pc 5 frequency range are fairly common at the equatorial region in the dawn magnetosphere (−5 ≤ X GSM ≤ 5). The amplitudes of these oscillations sometimes exceed 250 km/s. We examined in detail several events associated with temporal magnetopause crossings during the course of oscillations. It is found that plasma flow oscillations near the magnetopause correspond closely with magnetic field pulsations at latitudes of 70 – 75 degrees on the ground, although the form of the flow oscillation is spiky rather than sinusoidal. The boundary normal inclines sunward (tailward), when the spacecraft enters the magnetosheath (magnetosphere). Most of magnetopause crossings analyzed are cases with high magnetic shears (Bz in the magnetopause was negative in most cases). Outward and sunward flows, whose magnitudes are greater than those in the magnetosheath, were observed in the magnetosphere after inbound crossings, while inward and tailward flows were detected before outbound crossings. These characteristics are not necessarily consistent with the excitation of surface waves by the Kelvin-Helmholtz instability. A high-speed flow with the sunward and outward component was also observed in the magnetosphere after the inbound crossing with high magnetic shear in an isolated and temporal magnetopause crossing event drivent by a pressure pulse.

Accepted: 1998-07-15, 資料番号: SA1002535000

Accepted: 1997-10-27, 資料番号: SA1002488000

Accepted: 1997-01-10, 資料番号: SA1002482000

Accepted: 1997-01-10, 資料番号: SA1002483000

著者人数：13名, 資料番号: SA1002447000

著者人数：18名, Accepted: 1996-05-24, 資料番号: SA1002516000

南極周回気球(ボーラー・パトロール・バルーン : PPB)計画は, 1984年国立極地研究所, 宇宙科学研究所および大学機関の研究者が中心になって検討会が発足し, PPB実験に必要な成層圏での輻射環境および風系等の気象学的研究, 基本搭載計器の開発および気球放球設備の整備等が検討された。この計画は, 気球を成層圏内に一定高度を保ちながら数週間位浮遊させ, 南極大陸の周りを安定した風系に乗せ周回させることである。検討および開発は順調に行われ, 1987年第28次観測隊によって, 最初のテストフライが行われ, 続いて1989年第30次観測隊によって, 周回を目指したPPB気球が放球された。1991年より本格科学観測のためのPPB気球が放球され, 改めてPPB気球の有効性が再確認されてきた。本稿では, PPB気球実験のあらましおよび成果をまとめ, 今後多岐にわたる分野の研究者の示唆を得ることと利用の際の参考になることを目的として現在の状態を記す。, Since 1984,the National Institute of Polar Research and the Institute of Space and Astronautical Science have studied the feasibility of a long duration circumpolar balloon experiment, called Polar Patrol Balloon (PPB) project. This project aims at establishing a PPB system to bring scientific playloads in the stratosphere over the Antarctic region by large zero-pressure balloons. Three test balloon flights in 1987 and 1989 at Syowa Station have shown that the PPB would have a good condition of coming back to the Iaunching site during the summer season in Antarctica. The PPB experiments for scientific observation were consequently carried out since 1991. It would be necessary to continue, because we have a lot of interesting research subjects in many scientific fields in the Antarctic region. This paper will describe the summary of the balloon launching system and the scientific ballooning technology of the PPB project., 資料番号: SA0167038000

1989年3月13日の大磁気嵐中に, EXOS-Dに搭載されたフラックスゲート磁力計により観測された沿磁力線電流(FAC)の特性について報告する。本磁気嵐は地磁気観測史上有数の磁気嵐であり, その間にEXOS-Dは午前昼間側及び夕方側で大規模なFACを観測した。午前側のFACの特性は, 1)地磁気嵐主相では, 地磁気緯度で50°から80°にも及ぶ広いFAC領域が観測された。2)FACの極性は, 低緯度から上向き, 下向きのFACの他にそれらの高緯度側に上向きの大規模FACが出現した。3)この高緯度側の上向きFAC高緯度境界に狭い緯度巾(1.5°)のペアーのFACが観測された。夕方側のFACの特性は, 1) FACの低緯度側境界はSSCの直後から低緯度側に移動しはじめるが, 高緯度側境界は即座には反応しない。2)磁気嵐の回復期には逆に高緯度境界は直ぐに反応し高緯度側に移動しはじめたが, 低緯度側境界は遅れて反応した。, The EXOS-D satellite was launched on February 22,1989 into an elliptic orbit with a 75°inclination and with an initial perigee and apogee of about 275km and 10500km, respectively. Although the complete set of observations did not begin until the beginning of April, the fluxgate magnetometer was in operation during the great magnetic storm of March 13,1989,which has been one of the greatest storms this century. This preliminary report describes the characteristics of the field-aligned currents (FACs) observed by EXOS-D in the morning and evening sectors during this magnetic storm. The FAC system in the morning sector observed during the main phase spread greatly in invariant latitude (33°), its lowest latitude reaching as low as 50°. FAC events both in the main and recovery phases showed the following common features : (i) The presence of a pair of distinct FAC regions, an upward current on the poleward part and a downward current equatorward; (ii) the existence of a pair of FACs with narrow latitudinal width (1.5°) at the poleward edge of upward current in (i). In the evening sector the lower latitude boundary of the FACs began to move equatorward right after the SSC and eventually reached as low as 50°, but the higher latitude one did not immediately respond to the SSC. As the recovery the storm progressed, on the other hand, the higher latitude boundary of the FACs returned poleward more quickly than the lower latitude boundary., 資料番号: SA0166928000