• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전력기술부문
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• pp.106-108
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• 2001

As 3V cathode material, a new doping spinel material, LiMn1.6Se0.4O4 powder with a phase-pure polycrystalline was synthesized by a sol-gel method. In spite of Jahn-teller distortion in 3V region($2.4{\sim}3.5V$), the LiMn1.6Se0.4O4 electrode shows no capacity loss. The material in the 3V region initially delivers a discharge capacity of 100mAh/g which increase with cycling to reach 105mAh/g after 90cycles. And 5V cathode material LiNi0.5-xMxMn1.5O4(M=Cr, V, Fe) compounds have been synthesized by sol-gel method. a series of electroactive spinel compounds, LiNi0.5-xMxMn1.5O4(M=Cr, V, Fe) has been studied by crystallographic and electrochemical methods. The material presents only one plateau at around 4.5 V vs. Li/Li+ with a large discharge capacity of 152mAh/g and fairly good cyclability.

• Nuclear Engineering and Technology
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• 제52권11호
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• pp.2613-2619
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• 2020

This work investigated the gamma-ray shielding performance, and the physical and mechanical properties of poly (methyl methacrylate) (PMMA) composites embedded with 0-44.0 wt% bismuth trioxide (Bi₂O₃) fabricated by the fast ultraviolet (UV) curing method. The results showed that the addition of Bi₂O₃ had significantly improved the gamma shielding ability of PMMA composites. Mass attenuation coefficient and half-value layer were examined using five gamma sources (Cs-137, Ba-133, Cd-109, Co-57, and Co-60). The high loading of Bi₂O₃ in the PMMA samples improved the micro-hardness to nearly seven times that of the pure PMMA. With these enhancements, it was demonstrated that PMMA/Bi₂O₃ composites are promising gamma shielding materials. Furthermore, the fast UV curing exerts its great potential in significantly shortening the production cycle of shielding material to enable rapid manufacturing.

• 한국재료학회지
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• 제7권7호
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• pp.608-617
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• 1997

전자빔 용해법에 의해 고순도 티타늄잉고트 및 버튼시편을 제조하였다. 이들 중 18개의 금속불순물을 GDMS(Glow Discharge Mass Spectrometry)로 그리고 탄소, 질소, 산소의 함량을 고온연소법으로 측정한 후 이들과 전기비저항, 경도와의 관계를 조사하였다. 99%와 99.6%스폰지를 용해한 경우 대부분의금속불순물들이 대폭 감소하는 큰 휘발 정련효과가 나타났으며 비금속불순물들의 경우는 장비의 진공상태에 따라 큰 영향을 받으며 정련효과를 기대할 수 없었다. 금속 불순물중 철은 가장 제거하기 어려운 원소로 밝혀졌으며 이는 원료 스폰기중에서 철이 주불순물이기 때문이며 추가적인 예비정련이 필요한 것으로 나타났다. 상온 및 액체질소온도에서의 전기비저항은 가스불순물의 량이 증가함에 따라 직선적으로 증가하였으며 이들의 저항비($\rho$$_{RT}$ /$\rho$$_{N2}$)는 가스불순물의 총량이 1,000ppm이하의 경우 불순물량이 감소함에 따라 급격하게 저하하였으며 이 이상인 경우 완만하게 감소하였다. 이들의 경도는 가스불순물의 량이 증가하였으며 산소당량의 평방근에 비례하는 것으로 나타났다.다.

• 대한한방소아과학회지
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• 제19권2호
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• pp.51-68
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• 2005

Objective : Rumenshiqin(儒門事親) was compiled by Zhang Zi Huo(張子和) of the Jin(金) Dynasty of China. He invented unique medical theory and treatment such as three excretive methods(perspiratory, vomitory and purgative therapy). The aim of this study was to make the best use of the therapeutic theory of Rumenshiqin(儒門事親) connected with pediatrics. Methods: We conducted literature search in detail for contents of Rumenshiqin(儒門事親) and reviewed various kinds of books. Results : Zhang Zi Huo(張子和) recognized that children had pure-yang bodies(純陽之體) and emphasized that children need to prevent heat-stagnation(鬱熱) and asthenic yin(損陰). He instructed that a principle of raising such as wearing thin clothes, eating fresh food, harboring little desire and little anger, and taking temperate medicine. He described that pathogenic factors were mistake of rearing, misuse of medicine, exogenous factor, and excessive emotion. Conclusion : According to the above results, it is concluded that his therapeutic theory should be used at present.

• 한국분말재료학회지
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• 제12권1호
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• pp.56-63
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• 2005

Ag powder was prepared from $AgNO_3$ by wet chemical reduction method using various reduction agent system involving $AgNO_3$, $AgNO_2$(AgCl) and Ag complex ion aqueous solution. The pure Ag powder could be prepared regardless of reaction system but the particle shape and distribution were affected very much according to the kind of reduction agents and reaction systems. The optimum reaction system for the preparation of the silver powder having the uniform particle shape and size distribution was Ag complex ion aqueous solution-reduction agent system and in particular, $H_2O_2$ and $C_6H_8O_6$as a reduction agent leaded the more uniform particle shape and size distribution.

• 한국초전도저온공학회:학술대회논문집
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• 한국초전도저온공학회 2003년도 추계학술대회 논문집
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• pp.139-141
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• 2003

Multiple CeO$_2$/YSZ/Y$_2$O$_3$buffer layers, and subsequent YBCO films were deposited on the biaxially textured pure Ni and Ni ＋ 3at％W substrates using pulsed laser deposition. The deposition conditions of buffer layers on Ni and NiW were studied and compared. Good biaxial textures of buffer layers have been obtained on both substrates. The Jc's of YBCO films on these metal substrates were greater than 1$\times$10$^{6}$ A/$\textrm{cm}^2$ at 77K, 0T.

• The International Journal of Costume Culture
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• 제3권2호
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• pp.124-135
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• 2000

This research investigated the difference in fabric preference over formal wear attire of 1999 Spring/Summer season between Korean and American female consumers. 25 Korean and 25 U.S.A. fabrics were used as fabric samples, and the respondents for the survey included 50 Koreans and 50 Americans in the 20s and 40s age groups. All six population groups showed similar dislike rankings toward the total fabrics (n=50). When the Korean fabrics and the U.S.A. fabrics were considered separately, the 20s and 40s age groups, especially between Korean 20s and Korean 40s, showed significant similarities in the dislike rankings. When the dislike preferences between Korean fabrics and U.S.A. fabrics were examined for different population groups, all the groups showed somewhat similar dislike rankings and in all cases U.S.A. fabrics were disliked more than the Korean fabrics. The most apparent difference in the physical characteristics of disliked fabrics was observed in jabric color. The Americans, especially the 40s age group, disliked fabrics with dark compound colors, whereas the Koreans in all age groups dislike fabrics close to bright pure colors.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.294-296
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• 2017

본 연구에서는 대체 혼합물을 이용하여 케로신의 초임계 조건에서의 열전달 특성을 예측하고 이를 열전달 계산에 적용하는 연구를 수행하였다. 케로신의 열전달 특성은 NIST SUPERTRAPP을 사용하여 대표 물질의 열물성 데이터를 조합함으로써 모사하였다. 본 연구를 통해 획득한 케로신의 열물성 DB는 초속 연소기의 재생 냉각 열교환기의 설계 변수 결정에 사용할 예정이며, 재생냉각 연소기의 연소 시험 결과와 비교를 통해 예측된 열물성 데이터의 타당성을 검증해 나갈 예정이다.

• Macromolecular Research
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• 제12권3호
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• pp.263-268
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• 2004

We have synthesized a water-soluble polyimide precursor, poly(amic acid) amine salt (PAD), from pyromellitic dianhydride (PMDA), 4,4'-oxydianiline, and N,N -dimethylethanolamine (DMEA) and have investigated in detail its properties with respect to the degree of salt formation (D$\_$sf/). The maximum value of D$\_$sf/ we obtained upon precipitation of the precursor solution into acetone was 79%. We synthesized a PAD having a D$\_$sf/ of 100% (PAD100) by the solid state drying of an organic solution. The precursors showed different solubility depending on the D$\_$sf/ to make up to 4 wt% solutions in water containing a small amount of DMEA. PAD100 is completely soluble in pure water. We investigated the imidization behavior of PAD in aqueous solution using various spectroscopic methods, which revealed that PAD 100 has faster imidization kinetics relative to that of the poly(amic acid)-type precursors. The resulting polyimide films prepared from an aqueous precursor solution possess almost similar physical and thermal properties as those prepared from N-methyl-2-pyrrolidone(NMP) solution. Therefore, we have demonstrated that PAD can be used as a water-based precursor of polyimide; this procedure avoids the use of toxic organic solvents, such as NMP.

• 패션비즈니스
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• 제8권6호
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• pp.39-56
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• 2004

At the outset, surrealism starts from pure art, but surrealism has greatly influenced commercial art and fashion circles, more so than any other genre of art. The critical thinking methods of surrealism and its mode of expression continues to influence fashion theory extensively. Even now, surrealism may be found in the designs presented in fashion circles and is still expected for future lines. Surrealism in modern fashion has been reborn, newly integrated and transformed, based on the features of Surrealism paintings. The characteristics of its forms can be found in a combination of modern material, modern design and new skills and the classical items : bodyform molding context of architecture, experimental and sex-appealing of body. Expression was made by borrowing natural motives and recreating natural fabrics while the existing typical idea about clothes was destructed, with the boundary of patterns changed. Expression was also made by mixing items, uniting future images, and using up-to-date functional techniques. This study is significant that up-to-date technological culture expands cyber-space and increases surrealistic expressions by combined heterogeneous materials, thus arousing much interest. The purpose of this study is to determine interrelationship between how surrealism developed and what formative properties those clothes affected by surrealism obtained in the 1990s.