Effects of the amount of nickel powder (Ni) in Ni-carbon fiber (CF) hybrid filler systems on the conductivity(or resistivity) and thermal coefficient of resistance (TCR) of filled high density polyethylene were studied. Increases of the resistivity and TCR with increasing Ni concentration at a given hybrid filler content were observed. Using the fiber contact model, we showed that the main role of Ni in the hybrid filler system is to decrease the interfiber contact resistance when Ni concentration is less than the threshold point. The formation of structural defects leading to reduced reinforcing effect resulted in both a reduction of strength and an increase of the coefficient of thermal expansion in the composite film; these changes are responsible for the increases of both resistivity and TCR with increasing Ni concentration in the hybrid filler system.

We have developed a near real-time flare alerting system which (1) downloads the latest GOES-l0 1-8 Å X-ray flux 1-min data by an automated ftp program and shell scripts, (2) produces a beep sound in a simple IDL widget program when the flux is larger than a critical value, and (3) makes it possible to do a wireless alerting by a set of portable transceivers. Thanks to the system, we have made successful Ha flare observations by the Solar Flare Telescope in Bohyunsan Optical Astronomy Observatory. This system is expected to be helpful for ground-based flare observers.

본 연구에서는 GnRH가 과배란 처치된 래트의 초기 난포기와 후기 난포기에서 난소기능에 어떠한 영향을 미치는지를 이해하기 위해서, 30IU PMSG와 10IU hCG로 전처치된 미성숙 래트에 있어서 배란반응, 배란 난자의 형태학적 이상 유무 및 핵 성숙도, 난소 중량, 난소의 조직학적인 변화 및 혈중 스테로이드 호르몬 (17-estradiol, progesterone 및 testosterone) 농도에 대하여 GnRH agonist의 효과를 검사하였다.

Recent high resolution CO observations of normal and starburst galaxies at Owens Valley Millimeter Array are summarized. While normal disk galaxies generally show exponential distribution which follows the optical blue light, starburst galaxies are often characterized by a compact (~1 kpc) nuclear complex whose surface gas mass density is strongly correlated with the observed large infrared luminosity and thus the ongoing massive star formation.

With a modern microdensitometer and POSS glass copies, we have performed an automated star counting in two colors, blue and red, over the region containing Bok globule B361. Distribution of the measured extinction values over the projected angular distance from the cloud center was approximated by a power-law, and the resulting power-law indices for the blue and red are shown to be distinctly different from each other. The difference in the power-law index indicates that the mean dust size increases towards the cloud center. Possible physical causes for such size variation are briefly discussed.

Drought is one of the most important types of abiotic stress that affects stability and amount of yield. This study was conducted to screen for drought tolerance at early seedling stages for 318 ecogeographically diverse wild barley (HordeumvulgareL.spp.spontaneum) diversity collection (WBDC). Considerable variation was observed for all the seedling characters examined. Seedling growth was significantly reduced by 17% polyethyleneglycol -induced osmotic stress with significant variation among accessions. Comparison of mean performance under normal and osmotic stress conditions indicated that shoot length was the most sensitive trait, followed by seedling length, seminal root number, root-shoot length ratio and root length. The mean of root-shoot length ratio, however, increased under osmotic stress. Correlation studies indicated that the root length was the most important trait, followed by shoot length and root-shoot length ratio. The accessions from the Fertile Crescent and North Africa showed more drought tolerance than those from the other geographical regions. The accessions WBDC009 (Jordan), WBDC075 (Libya), WBDC181 (Jordan), WBDC242 (Jordan) and WBDC280 (Israel) exhibited the lowest stress susceptibility index ‘S’ values. Consequently, these accessions showed tolerance to drought at the early seedling stage and are considered to be good sources of drought tolerance for cultivated barley improvement. This work was supported by a grant from Regional Subgenebank Support Program of Rural Development Administration, Republic of Korea .