비대칭 폴리비닐리덴플루오라이드(PVDF) 막을 상전환법으로 제조하였다. 도포용액은 PVDF를 용매인 N-ethyl-2-pyrrolidone (NMP)와 비용매인 1,4-dioxane, diethyleneglycol dimethyl ether (DGDE), acetone, (equation omitted)-butyrolactone(GBL)의 혼합용매에 녹여서 제조한다. 여러 첨가제가 도포용액 특성, 투과특성과 막 구조에 미치는 영향을 조사하였다. 응고제인 물과 1,4-dioxane, DGDE, acetone과의 상용성이 NMP보다 낮아서 기공크기가 작아진다. 첨가제의 양을 조절하여 기공크기를 변화시켰다. 혼합용매(수계 및 비수계)가 막의 투과성능에 미치는 영향을 살펴보았다. 용액점도뿐만 아니라 표면장력도 용매 투과특성에 영향을 끼침을 알 수 있었다.

Clusters of galaxies are storage rooms of cosmic rays. They confine the hadronic component of cosmic rays over cosmological time scales due to diffusion, and the electron component due to energy losses. Hadronic cosmic rays can be accelerated during the process of structure formation, because of the supersonic motion of gas in the potential wells created by dark matter. At the shock waves that result from this motion, charged particles can be energized through the first order Fermi process. After discussing the most important evidences for non-thermal phenomena in large scale structures, we describe in some detail the main issues related to the acceleration of particles at these shock waves, emphasizing the possible role of the dynamical backreaction of the accelerated particles on the plasmas involved.

μ방lt emitting diodes (LED) devices are commercially introduced as an alternative for low-Ievellaser therapy (11ι，T) ， and it has several advantages over lasers such as a safe, efficient, and less-expensive altemative to treat wounds. And LED irradiation at the same biostimulatory wavelength has similar bíochemical effεαs. In the present study, to asses whether the I핑ht-emitting diode (LED) irradíation can stimulate bone regeneration, irradiated bony defects with or without grafting materials on rat calvaria were compared to corresponding nonirradiated control. Fifty male Sprague-Dawly rats weighing about 150g, were used. Factors for present study were designed as follows, 1) presence or absence of grafting materials, 2) with or without irradiation, and 3) number of irradiation. Two weeks after operation, rats were sacrifìced. Radiologic and 비stomorphologic fmdings were evaluated. Macrospically, there were no incidents of infection, dehiscence, hematoma and necrosis during study. Radiological findings showed greater radiopacity in the graft group and radiopacity increased as the number of irradiation increase. And microscopically, new bαle formation was great in the graft group and increased as the number of irradiation increase, Present study has shown that LED irradiation improved bone regeneration through radiologic and histomorphologic fmdings in rat.

Molecular clouds present many levels of structure, including clumps and cores of varying size and density. We present a brief summary of these cores, describing their observed physical properties and their place in the star formation process. We conclude with some speculation about pre-proto-stellar stages of molecular cores and the observational challenges in their observation.

Disk galaxies abound with intermediate-scale structures such as OB star complexes, giant clouds, and dust spurs in a close geometrical association with spiral arms. Various mechanisms have been proposed as candidates for their origin, but a comprehensive theory should encompass fundamental physical agents such as self-gravity, magnetic fields, galactic differential rotation, and spiral arms, all of which are known to exist in disk galaxies. Recent numerical simulations incorporating all these physical processes show that magneto-Jeans instability (MJI), in which magnetic tension resists the stabilizing Coriolis force of galaxy rotation, is much more powerful than swing-amplification or the Parker instability in forming self-gravitating intermediate-scale structures. The MJI occurring in shearing and expanding flows off spiral arms rapidly forms structures elongated along the direction perpendicular to the arms, remarkably similar to dust spurs seen in HST images of spiral galaxies. In highly nonlinear stages, these spurs fragment to form bound clumps, possibly evolving into bright arm and interarm H II regions, suggesting that all these intermediate-scale structures in spiral galaxies probably share a common dynamical origin.

본 연구에서는 유의미 학습을 촉진시키고 학습자들이 나름대로 개념을 형성하는 과정을 확인할 수 있는 방법인 개념도를 이용하여 중학생들의 ‘해수‘ 개념 형성에 미치는 영향에 대해 알아보았다. 이를 위하여 부산광역시의 중학교 1학년 4개 학급 128명을 대상으로 개념도를 활용한 수업 전-후에서 과학 학업 성취도와 자기 주도적 학습특성 및 개념도에 대한 인식을 조사해 본 결과는 다음과 같다. 첫째, 과학 학업 성취도에 미치는 효과는 유의수준 .05에서 유의미한 차이가 있는 것으로 나타났다. 둘째, 개념도를 활용한 수업은 전통적 수업 집단에 비해 학습자의 자기 주도적 학습특성을 향상시키는데 효과적인 것으로 나타났다. 셋째, 개념도를 활용한 수업이 개념 형성에 궁극적인 반응을 하는 것으로 나타났다.

Liquid crystal (LC) system was introduced into W/O emulsion in order to enhance the stability and moisturizing effect. The LC system, composed of beeswax, surfactant, and water was formed on the surface of emulsion droplet, which was investigated through a polarized microscope. The phenomenon that the viscosity in W/O emulsion system is decreased with time, was reduced by the formation of LC with the addition of beeswax. Centrifugal separation test showed that the stability of emulsion system was increased with the addition of beeswax to 3%. The color change of vitamin C was delayed in LC emulsion systems, which indicates stabilization effect against the oxidation of vitamin C. Evaporation rate in W/O emulsion was retarded by LC, so that high moisturizing effect is expected in W/O LC system.

Compared to the influences of Korean art journalism, the researches on them are rarely conducted. This study aims to examine the influence of art journalism in art magazines in Korea. Although it is essential to consider media, journalism, public opinion altogether, I focused only on the media due to the absence of previous studies. I have analyzed the current conditions of korean art journalism, types of feature articles, sponsors, their relations with articles, and the comparison with foreign art journalism in terms of production conditions. There have been about one hundred art magazines published in previous sixty years and currently there are twenty three. Monthly periodicals are the majority; the publishers are sorted out as publishing houses, galleries, newspaper company in order; specialized art magazines developed from the eighties. Through an examination of feature articles in these art magazines, I found that they repeated similar art issues and covered the same artists, sponsors and articles. Moreover, when the magazines went through the conflicts between managers and editors, the ascendency of managers obstructed the development of art journalism regarding journal quality. These days, art journalism have been comparatively regressed compared to other art systems such as art museums, curatorship, international art festivals, distributions and art promotion policies. The main causes for failure were the lack of professional management, the limited effort to diversify sponsors, and the repetition of the same informants and events without making an effort to be specialized. Magazines are published media which contribute to the creation of culture, distribution, and preservation. Therefore art magazines can be said the most influential media in forming art culture and distributing it. It is quite necessary to reform the problems of repeating of information and the lack of speciality in conjunction with the commitment of management and editorialship.

This paper presents the application of integrated mathematical programming approach for the design of cellular manufacturing. The cores of the proposed approach are two phases; concurrently a dealing with exceptional elements(EEs) and cell formation and facilities layout design. A policy dealing with EEs considers minimizing the total costs of three important costs ; (1) intercellular transfer (2) machine duplication and (3) subcontracting. And important issue is the calculation of the number of machines needed by considering the maximum utilization of machines and the available capacity of a machine that can be transferred for intercell moving is an key. Facilities layout design is considered to reflect the real field data such as the operation sequence of the parts to be manufactured. quadratic. The model is formulated as mixed integer programming that is presented to find the optimal solution.

이 연구는 약용버섯 번데기 동충하초로부터 특이적 자실체 형성 유전자를 선별하기 위하여 수행하였다. cDNA는 버섯의 분화 4단계 균사체, 원기, 미성숙 자실체, 성숙한 자실체로부터 분리한 각각의 total RNA를 이용하여 합성하였다. 특이적으로 발현된 유전자의 선별은 cDNA와 랜덤한 primer set을 이용한 DD-PCR에 의해 수행되었고, pGEM 클로닝 벡터를 이용하여 6개의 partial 유전자 서열을 확인하였다. 6개의 DD-PCR product는 보고된 유전자와 유사도를 확인하기 위해 NCBI BLAST search를 사용하여 GenBank에서 비교하였고, 6개의 유전자는 보고되지 않은 유전자임을 확인하였다.

The mesophase pitch was prepared by adding 1~10 wt% of the borane-pyridine complex (BPC) to decant oil. It was prepared in a reactor held at 450℃ for 2 h in N2 atmosphere. The mesophase pitches were analyzed using thermogravimetric analyzer (TGA), melting point apparatus, X-ray diffraction (XRD) and polarized optical microscope. The coke yield, softening point, toluene insoluble, density and content of anisotropy in the mesophase pitches were increased with BPC contents. The XRD profiles did not show any effect of addition of BPC on the formation of mesophase pitch, while the crystallinity of mesophase pitches was increased when the materials were heat treated with boron compound.