• 공업화학
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• 제26권6호
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• pp.674-680
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• 2015

리튬이차전지 실리콘 전극에 활용하기 위해, 유기용매에 용해성이 있는 폴리이미드(Polyimide, PI) 고분자 바인더를 두 단계 반응을 이용해 합성하였다. 두 가지 단량체(Bicyclo[2,2,2]oct-7-ene-2,3,5,6-tetracarboxylic Dianhydride (BCDA)와 4,4-oxydianiline (ODA))의 개환 반응 및 축합 반응을 통해 PI 고분자 바인더를 합성하였다. 합성된 PI 고분자 바인더를 이용해 실리콘(silicon, Si) 음극 전극을 제조하였다. 또한 비교군으로써, Polyvinylidene Fluoride (PVDF)을 고분자 바인더로 사용하는 동일 조성을 가진 실리콘 전극을 제조하였다. PI 바인더를 사용한 Si 전극($2167mAh\;g^{-1}$)의 초기 쿨롱 효율은 기존 PVDF 바인더 조성의 Si 전극($1,740mAh\;g^{-1}$)과 유사했지만, 방전용량은 크게 개선되었다. 특히 수명 특성에서는 PI 바인더를 사용한 Si 전극이 우수한 특성을 나타내었는데, 이는 PI 바인더를 사용한 Si 전극접착력($0.217kN\;m^{-1}$)의 전극 접착력이 PVDF를 사용한 Si 전극($0.185kN\;m^{-1}$)보다 높아, 실리콘 부피팽창에 의한 전극 구조 열화가 적절히 제어되었기 때문이라고 판단된다. Si 전극 내의 접착력은 surface and interfacial cutting analysis system (SAICAS) 장비를 통해 검증하였다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.93-93
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• 2017

To develop rice cultivars with increased biomass and grain yield, superior lodging resistance is an essential trait. The new breeding approach can be adopted for the improvement of stem lodging resistance by enhancing culm strength. The resistance to breaking type lodging is attributed to bending moment of basal culm (M), which is composed of the section modulus (SM) and bending stress (BS). The resistance to the bending type lodging is attributed to flexural rigidity (FR) of stem, which is composed of the secondary moment of inertia (SMI) and Young's modulus (YM). Starch and cell wall components such as cellulose, hemicellulose and lignin also play a significant role in physical strength of culm, and thus affect lodging. Leaf Star has a superior lodging resistance due to its thick and stiff culm because of its high M and FR compared with Koshihikari. Furthermore, Leaf Star contains high densities of hemicellulose, cellulose and low lignin density in culm compared with Koshihikari. In this study, we performed QTL analysis for these traits associated with culm strength, using 94 recombinant inbred lines (RILs, $F_8$), derived from a cross between Leaf Star and Koshihikari. The SM in the RILs showed a continuous distribution. QTLs for SM were detected on chrs.2, 3 and 10. Leaf Star alleles increased SM on chrs. 2 and 3, but Koshihikari allele increased on chr.10. These QTLs overlapped with those QTLs identified using backcrossed inbred line derived from a cross between Chugoku 117 and Koshihikari, the parents of Leaf Star. The FR in Leaf Star was higher than that in Koshihikari due to the larger SMI and YM. 3 QTLs for SMI were detected on chrs.2, 3 and 10. Leaf Star alleles increased SMI on chrs.2 and 3, and Koshihikari alleles increased on chr.10. One QTL on chr.3 and two QTLs on chr.5 for hollocelulose content were detected with Leaf Star alleles contribution. Moreover, two QTLs were detected for hemicellulose density on chrs.3 and 5. Leaf Star allele increased hemicellulose density on chr.5, and Koshihikari allele increased on chr.3. Furthermore, two QTLs for cellulose density were detected on chr.5, and one QTL on chr.2. For starch content, one QTL on chr.3 and two QTLs on chr.5 with Leaf Star alleles contribution were detected. TULK-6 carrying a chromosome segment of Leaf Star on chr.5 in the Koshihikari genetic background showed higher densities of starch and hemicellulose than those in Koshihikari. These results suggest that the detected QTLs for culm strength could be utilized for the improvement of lodging resistance in rice by marker-assisted selection.

• Geomechanics and Engineering
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• 제14권1호
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• pp.99-105
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• 2018

Soils are generally classified as fine-grained or coarse-grained depending on the percentage content of the primary constituents. In reality, soils are actually made up of mixed and composite constituents. Soils primarily classified as fine-grained, still consists of a range of coarse particles as secondary constituents in between 0% to 50%. A laboratory scale model test was conducted to investigate the influence of coarse particles on the physical (e.g., density, water content, and void ratio) and mechanical (e.g., quick undrained shear strength) properties of primarily classified fine-grained cohesive soils. Pure kaolinite clay and sand-mixed kaolinite soil (e.g., sand content: 10%, 20%, and 30%) having various water contents (60%, 65%, and 70%) were preconsolidated at different stress levels (0, 13, 17.5, 22 kPa). The quick undrained shear strength properties were determined using the conventional Static Cone Penetration Test (SCPT) method and the new Fall Cone Test (FCT) method. The corresponding void ratios and densities with respect to the quick undrained shear strength were also observed. Correlations of the physical properties and quick undrained shear strengths derived from the SCPT and FCT were also established. Comparison of results showed a significant relationship between the two methods. From the results of FCT and SCPT, there is a decreasing trend of quick undrained shear strength, strength increase ratio ($S_u/P_o$), and void ratio (e) as the sand content is increased. The quick undrained shear strength generally decreases with increased water content. For the same water content, increasing the sand content resulted to a decrease in quick undrained shear strength due to reduced adhesion, and also, resulted to an increase in density. Similarly, it is observed that the change in density is distinctively noticeable at sand content greater than 20%. However, for sand content lower than 10%, there is minimal change in density with respect to water content. In general, the results showed a decrease in quick undrained shear strength for soils with higher amounts of sand content. Therefore, as the soil adhesion is reduced, the cone penetration resistances of the FCT and SCPT reflects internal friction and density of sand in the total shear strength.

• 대한관절경학회지
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• 제15권1호
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• pp.13-18
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• 2011

목 적: $TightRope^{(R)}$ (Arthrex, Inc, Naples, FL)를 이용한 급성 견봉쇄골 관절 탈구의 관절경적 오구쇄골 관절 고정술의 방사선학적 및 임상적 결과를 평가하고자 한다. 대상 및 방법: 2009년 2월부터 2010년 2월까지 Rockwood 3형 또는 5형의 급성 견봉쇄골 관절 탈구 환자 20명에 대해 $TightRope^{(R)}$를 이용하여 관절경적 오구쇄골 관절 고정술을 시행하였다. 추시 기간은 평균 13.4(10~22)개월이었다. 방사선학적 평가는 쇄골 관절 부하 사진을 통해 쇄골과 오구돌기 사이 거리를 건측과 비교하였고, 임상적 평가는 KSS(Korean Shoulder Scoring System)를 이용하였으며, 환자들의 미용적 만족도도 평가하였다. 결 과: 방사선학적 평가에서 18예는 매우 우수, 1예는 우수, 1예는 양호의 결과를 보였다. KSS는 평균 98.5(92~100)점이었으며, 전 예에서 만족할 만한 미용적 결과를 보였다. 1예에서 매듭에 의한 피부 압통 및 촉진되는 불편감을 호소하여 시행한 매듭 봉합술 후 국소 감염이 발생하여 국소 마취 하 배농술 및 2주간 항생제 사용으로 치유하였다. 결 론: Rockwood 3형 또는 5형의 급성 견봉쇄골관절 탈구의 치료에 있어 $TightRope^{(R)}$를 이용한 관절경적 오구쇄골 관절 고정술은 만족스러운 방사선학적 및 임상적 결과를 보이며, 술후 합병증이 거의 없고, 조기 재활이 가능하며, 뛰어난 미용적 결과를 보이고, 금속 고정물 제거를 위한 이차적 수술이 필요없는 훌륭한 치료 방법이 될 것으로 생각된다.

• 정보교육학회논문지
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• 제11권4호
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• pp.447-459
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• 2007

최근 한국의 청소년들은 컴퓨터 보급의 확대와 컴퓨터 게임 산업의 발전으로 컴퓨터 게임의 이용이 급격히 늘고 있다. 청소년의 82.4%가 게임 경험을 가지고 있으며, 이중 22.4%는 매일 컴퓨터 게임을 하는 것으로 나타났다. 컴퓨터 게임은 자신감과 집중력을 향상 시킬 수 있으며 인터넷 사용, 외국어 실력 그리고 인지 능력을 향상시켜 학습 효과를 촉진시킬 뿐만 아니라 스트레스를 풀어준다는 긍정적인 주장도 있으나 중독 증세로 인해 야기되는 부정적인 주장도 있다. Young(1996)은 컴퓨터 게임 중독이 다른 중독 현상처럼 통제상실, 갈망, 결혼불화, 학업실패, 재정적 결핍, 실직 등 사회적인 문제를 야기할 수 있다고 경고하고 있다. 이에 따라 본 연구에서는 컴퓨터 게임 중독이 청소년의 인성특성에 실제 어떤 영향을 미치는지를 알아보았다. 이를 위해 청소년의 컴퓨터 게임 이용 실태 조사, 컴퓨터 게임 중독 검사와 성별간의 차이 분석, 컴퓨터 게임 중독 정도와 인성특성간의 상관 분석 등을 실시하였다. 그 결과 컴퓨터 게임 중독은 청소년의 안정성, 자율성, 정서인식, 정서표현, 정서조절 등의 인성 특성에 부정적인 영향을 주는 것으로 확인되었다.

• Restorative Dentistry and Endodontics
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• 제27권1호
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• pp.77-86
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• 2002

Current composites are made with dimethacrylate monomers and silane-treated silica microfillers, either alone or with silane treated glass fillers The main reasons for clinical failure of dental composites are secondary caries, wear and fracture. Most of practitioner want to get a composite which is more tougher under occlusal stress, less polymerization contraction, and better handling properties in application clinically. The aim of this study was to investigate the influence of resin matrix with various flows on the physical proper-ties such as fracture toughness and degree of conversion of the experimental resins. It was hypothesized that flexible or tough resin composites can be designed by judicious choice of monomer composition Various flow resin matrices containing Bis-GMA, UDMA, and TEG-DMA were made by altering the pro-portion of the monomers. After the unfilled resins were light-cured for different light intensity, the fracture toughness(K$_{1c}$) was measured according to ASTM standard using the single edge notched geometry, and degree of conversion(DC) was measured by FTIR. And experimental composites were formulated with variations in the proportion of silanated quartz and strontium glass fillers as 60, 75, and 77wt%. Also, the physical properties of composites with various filer contents were evaluated as same manner. All resulting data were compared by ANOVA/Tukeys test at 0.05 level. The results were as follows; 1. The degree of conversion of high flow resin containing less Bis-GMA was higher than that of low flow unfilled resin 2. While the degree of conversion of unfilled resin was increased according to light intensity for polymerization, there was no significant increase with moderate and high light intensity. Also, the fracture toughness was not increased by high light intensity. 3. The fracture toughness was high in the low flow unfilled resin containing higher contents of Bis-GMA. 4. There was a significant increase for fracture toughness and a tendency for degree of conversion to be reduced when the content of fillers was increased. 5. In the experimental composites, the flow of resin matrix did not affected on the fracture toughness, even, which was decreased as increase of viscosity. These results showed that the physical properties of a dental composite could be attributed to the flow of resin matrix with relative content of monomers. Specific combination of resin monomers should be designed to fulfil the needs of specific indication for use.

• Korean Journal of Acupuncture
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• 제21권2호
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• pp.95-110
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• 2004

Objectives : Ulcerative colitis and Crohn's diseases are chronic inflammatory disease of the gastrointestinal tract identified mainly for diarrhea, stomachache, hemafecia. The source and pathologic mechanism about ulcerative colitis and Crohn's disease are still unknown but stress, infection, a genetic factor, environmental factors etc. may be the cause of chronic inflammatory disease of the gastrointestinal tract recently. Methods : Because ulcerative colitis and Crohn's disease is recognized as Ha-ri(下痢) or Jang-Byok(腸?) in Oriental Medicine, Rhizoma Coptidis Herbal acupunctures were injected in hapgok $(LI_4)$ which is used to treat intestinal disease in clinic. All animals were subjected to the injection of saline $(300\;{\mu}l,\;500\;{\mu}l)$ for a study control and TNBS $(300\;{\mu}l,\;500\;{\mu}l)$ into the lumen of the colon, 8cm proximal to the anus through the intestine. Rhizoma Coptidis Herbal (20 mg/ml, 0.4 ml) acupuncture solution was injected to the $LI_4$ (both hands) at the secondary injection time of TNBS in rats. And body weight, RBC count, WBC count, total protein, Paw edema rate, rate of protein leakage into CMC-pouch fluid, IgG levels and IgM levels were observed to study the effects of Rhizoma Coptidis Herbal acupuncture in hapgok $(LI_4)$. Results : In results, Rhizoma Coptidis Herbal acupuncture in hapgok $(LI_4)$ on TNBS-induced colitis reduced the rate of weight loss but had no effect on RBC and WBC count. And it reduced total protein concentration, paw edema, rate of protein leakage into CMC-pouch fluid, IgG levels and IgM levels. Conclusion : Data suggest that injection of Rhizoma Coptidis herbal acupuncture solution into hapgok has significant therapeutic effect on the colitis.

• 보건의료산업학회지
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• 제1권1호
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• pp.59-74
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• 2007

Considering the characteristics of the Korean family which maintain a close connection with their patients from the moment of their falling sick to hospitalization to discharge, the family is the most important environmental factor of the social supporting system, and is the important object of the client as well as activity system. The medical social work intends to meet the practical needs of aged chronic patients, providing them and their family with a professional human service. The end of this study is to find out the hardships of both the aged chronic patients and their family as well as their needs for the social welfare service, and to search out the way of comprehensive social work service. The summary of the analysis of the survey is as follows: 1. The needs of aged chronic patients are divided into those of the solution of the problems of falling ill, social welfare program and discharge. Those needs arc affected by the various factors of the types of hospitals, the patients' age, the kinds of insurance, and the supporting systems, etc. Accordingly, the assessment of the needs of the patients are asked to be done comprehensively in accordance with the kinds of diseases and social environments. 2. The importance of the family to the aged chronic patients is evident. The family plays a decisive role in the patients' hospitalization and discharge, the family being an important supporting system and making it necessary to take an approach to client system. The family has difficulty in getting connection of community resources, in adapting to social life after the patient's discharge, and in paying the treatment. The family suffers the secondary hardships more than the burden of the treatment expenses. 3. For this reason various interventions are needed to reduce the stress caused by supporting and nursing patients. Thus the social welfare service for the aged chronic patients and their family needs the following prepositions: 1. It is the characteristics of the aged chronic patients that they need continuous care and that the strengths of the patients and their family cannot be too much emphasized, and that comprehensive assessment based on the connection 'with the community and the mutual interchange 'with the environment, is much emphasized. 2. The family of the aged chronic patient is a resources system as well as a client one. 3. Another characteristic of the aged chronic patients is that with the resources connection in mind, it needs an active intervention of social workers in the community. With these prepositions considered, the development of practical social work service for the aged chronic patients is thought urgently needed.

• Applied Biological Chemistry
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• 제32권1호
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• pp.23-29
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• 1989

soybean hypocotyl에서 분리한 미토콘드리아로부터 submitochondrial particles와 matrix 단백질 추출액을 준비하고 전기분해법으로 제조한 superoxide를 처리하여 malate dehydrogenase 및 cytochrome C oxidase의 불활성화와 mitochondrial membrane의 과산화를 각각 조사하였다. 막에 결합되어 있는 cytochrome C oxidase나 수용액상태의 malate dehydrogenas는 모두 $O^{-}_{2}$에 대해 매우 민감하게 불활성화되었다. 즉 dismutation 반응이 빠르게 진행되어 실질적으로 효소의 불활성화에 기여하게 될 농도는 대단히 낮을 것으로 추정되는 $O^{-}_{2}$의 명목상 처리농도 1.4mM 전후에서 두 효소는 그 활성을 완전히 상실하였다. 한편 malondialdehyde의 생성을 지표로 하여 측정된 membrane 과산화는 인지질로서만 이루어진 liposome의 경우보다는 다소 낮은 수준이었으나 무시할 수는 없는 정도였다. mitochondrial membrane의 과산화가 상대적으로 억제된 것은 막에 결합되어 있는 항산화제 및 단백질들에 의한 $O^{-}_{2}$소거효과에 기인하였으리라 해석된다. 식물 미토콘드리아의 대표적인 대사과정인 TCA cycle과 호흡전자전달반응의 성분효소들인 malate dehydrogenase와 cytochrome C oxidase가 불활성화되었고 membrane이 과산화 되었다는 사실은, 식물의 냉해와 광피해 발현기작에서 공히공통적인 화학적 인자로 인정되는 $O^{-}_{2}$의 과잉생성 및 축적이 그것의 주 생성처인 미토콘드리아의 생화학적 기능과 구조에 미칠수 있는 파괴적 효과를 적절히 지시하는 것이다.

• 한국재료학회지
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• 제9권9호
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• pp.919-925
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• 1999

가공열처리에 의한 결정립계조절 개념을 이용하여 Alloy 600 재료의 결정립계특성과 부식특성을 조사하였다. 가공열 처리에 따른 결정립계특성 변화를 EBSP로 분석하였으며, 결정립계특성 변화가 입계부식 및 응력부식균열 거동에 미치는 영향을 평가하였다. 가공열처리 반복에 따른 각 단계에서의 CSL 입계의 분율 변화가 두드러지지는 않았으나, 상용재료에 비하여 CSL 분율이 약 10% 이상 향상된 결과를 얻었다. 결정립계특성 변화에 따라 입계부식 저항성이 현저하게 증가하였으나, 1차측 응력부식균열 특성에 있어서는 가공열처리를 반복할수록 파단시간과 최대하중이 감소하고 평균 균열성장속도가 증가하였으며 2차 균열이 억제되는 결과를 얻었다. 결정립계의 \`fine tuning\` 기구가 이러한 부식거동변화에 작용한 것으로 해석할 수 있었다.