열가소성 Wood-Plastic Composites의 기계적 물성에 미치는 커플링제의 영향

윤태호,신경섭,황택성,이존태 공주대학교 자원재활용 신소재 연구센터 1999 1차년도 센터 성과집 Vol.1999 No.-

목분 충진제의 함량을 달리 하고 PE수지를 매티릭스로 하여 wood plastic composites(WPC)를 제조하였다. 또한 매트릭스와 충진제간의 계면결합력을 증가시키기 위하여 커플링제로 phthalic anhydride(PA)를 사용하였으며, 충진제의 충진률과 커플링제 처리가 복합재의 기계적 물성에 미치는 영향과 계면현상을 관찰하였다. 목분의 충진률 30wt%, PA커플링제농도 3wt%일 때 인장강도는 26.37MPa로 최대값을 나타내었으며, 이때 충격강도는 46.24J/m의 최대값을 나타냈다. 또한 WPC는 주사전자현미경 관찰을 통해서 커플링제의 처리농도의 증가에 따라 목분과 PE 수지와의 분산과 결합이 잘 이루어졌으을 확인할 수 있었다. Wood powder as reinforcing fillers and polyethylene as a matrix have been used for wood plastic composites(WPC). In preparing WPC, the coupling agent, phthalic anhy dride(PA) was used in order to increase the interfacial bonding force between matrix and fillers. In this study, the effect of wood powder, PA concentration on the mechanical properties and interfcial phenomena on the composites was eveluated. The tensile strength of 3wt% PA-treated composites reached its maximum value of 25.91 MPa when the wood powder content was 30wt%, and the mximum impact strength of PA-treated composites was 46.24H/m. SEM observation showed that wood powder was well dispersed and bonded well with PE matrix by increasing the coupling agent concentration.

관상동맥 스텐트 내 재협착의 발생에 미치는 임상적 관동맥 조영술적 요인들

윤혁준,김기식,박형섭,이영수,현대우,한성욱,허승호,김윤년,김권배,박남희,원경숙 대한순환기학회 2003 Korean Circulation Journal Vol.33 No.12

『南北觀光 交流와 東海岸地域 觀光開發 方向摸索』

윤경호 江陵大學校統一問題硏究所 1999 統一問題硏究 Vol.15 No.-

嶺東地域 開發의 實態와 方向摸索

윤경호 강릉대학교 영동산업문제연구소 1991 産經論叢 Vol.13 No.-

STI571 (Glivec^(�))에 의하여 빠른 치료 반응을 보인 불응성 Gastrointestinal stromal tumor

윤경원,이제중,김여경,황호인,이병환,조상희,정익주,김형준 全南大醫大 2001 전남의대학술지 Vol.37 No.4

왜 다양한 항우울제가 필요한가?

윤호경,김용구 大韓神經精神醫學會 2008 신경정신의학 Vol.47 No.1

Depression is a chronic, recurring and potentially life-threatening illness. Depression is a syndrome notable for heterogeneity of its clinical presentation, treatment responsiveness, neurobiology, and genetics. The highly variable compilation of symptoms that is used to define depression, and the highly variable course of the illness and its response to various treatments, indicate that depression subsumes numerous disease states of distinct etiology, and perhaps distinct pathophysiology. Current under-standing ofthe mechanisms of pharmacotherapy for depression is characterized by the emphasis on increasing synaptic avail-ability of serotonin, noradrenaline, and possibly dopamine, while minimizing side effects. This is unfortunate, because less than half of individuals with depression show full remission in response to these mechanisms. While current phannacotherapies target monoaminergic systems, distinct neurobiological underpinnings and other systems are likely involved in the pathogenesis of depression. Recently, several promising hypotheses of depression and antidepressant action have been formulated. These hypotheses are largely based on dsyregulation of neural plasticity, CREB, BDNF, corticotropin-releasing factor, glucocorticoid, hypothalamic-pituitary adrenal axis and cytokines. Based on these new theories and hypotheses of depression, a number of new and novel agents show a considerable promise for refining treatment options for depression. In this article, we provide an overview of the mechanisms of action of currently available antidepressant treatments. We then provide a progress report on some of the most promising current strategies.

Characteristics of F₂Hybrids from Crosses between Korean Cultivars and Canadian Cultivars in Buckwheat(Fagopyrum esculentum Moench.)

Yoon,Kyoung-Min,Hong,Soon-Kwan,Park,Cheol-Ho 한국자원식물학회 2002 Plant Resources Vol.5 No.1

Korean cultivars of buckwheat(Fagopyrum esculentum Moench.) was crossed with Canadian cultivars in order to improve seed yield as well as leaf production of buckwheat for using as food and medicine. The agronomic characteristics and rutin contents of F₂hybrids are investigated for further selection of superior lines. Dry weight per plant was the highest in a line 1110(6.71g) and leaf weight per plant was the highest in a line 1110(1.91g). Hybrid seeds were 0.55 - 0.70cm long and 0.37 - 0.47cm wide on average. 100 seeds weight ranged from 2.57g to 3.58g. Line 1076 produced the longest seeds(0.70cm) and line 1186 was the longest in seed width. Line 1196 showed the highest 100 seeds weight(3.58g). The highest frequency of the LWR(length/width rate) was 0.66~0.70, indicating that seed shape of the hybrids was mostly oval. Line 1087 showed the highest contents of rutin(77.26ppm). Lines 1090 and 1181 contained respectively rutin of 54.76ppm and 54.35ppm in the seeds. From the yield and rutin point of view, the most superior lines was line 1087 among the lines used for this study.

성견에서 교정적 고정원으로서의 티타늄 미니스크류에 대한 연구 : An experimental investigation in dogs

윤병수,최병호,이원유,김경남,심형보,박진형 대한치과교정학회 2001 대한치과교정학회지 Vol.31 No.5

교정치료에서 원하는 치아이동을 위해서는 안정된 고정원이 필요한데 티타늄 미니스크류가 매식과 제거가 쉽고, 구강 내 여러 부위에서 적용이 가능하고, 환자가 느끼는 불편감이나 비용적인 부담이 적고, 제거 후에 치유가 빠르게 진행될 수 있는 등의 장점이 있어 최근에 교정적 고정원으로 사용되기 시작하였다. 티타늄 미니스크류를 교정적 고정원으로 사용한 임상 예들이 여러 편 발표되었는데 미니스크류의 이완이 가장 큰 실패의 원인으로 보고되고 있다. 그러나 지금까지 보고된 논문들에서 교정적 고정원으로 안정성을 줄 수 있는 스크류의 식립 길이에 관한 연구가 없는 상태이다. 교정적 고정원으로 미니스크류를 효과적으로 사용하기 위해서는 식립 부위에 따른 골구조와 골밀도 차이를 고려한 식립 길이에 관한 기준이 필요하다. 이에 본 연구에서는 성견의 상악골과 하악골에서 직경 2mm 티타늄 미니스크류를 다양한 길이로 식립하고 교정력을 적용한 후 그 안정성을 평가하여 교정적 고정원으로 사용될 수 있는 미니스크류의 식립 길이를 결정하고자 하였다. 미니스크류가 상악에서는 6mm이상, 하악에서는 4mm 이상이 골 내에 식립될 때 8주 동안 200g의 교정력에 동요도나 위치변화를 보이지 않았다. 식립 부위로는 부착치은 부위 치근 사이에 식립될 때 구강청결이 유지되고 미니스크류 주변 치은조직에 자극을 주지 않아 정상적인 조직으로 유지 될 수 있었다. 또한 교정력 적용 8주 후 치근단 방사선 사진검사에서 스크류 주변 치근 흡수나 치조골 흡수, 치주 인대 손상이 관찰되지 않았다. 따라서 상 ㆍ 하악 골밀도와 골구조의 차이를 고려하여 미니스크류의 골내 식립 길이를 적절히 조절함으로써 교정적 고정원으로 티타늄 미니스크류가 효과적으로 사용될 수 있다고 생각된다. Titanium miniscrews are being used increasingly as an anchorage for tooth movement, because they are easy to place and to remove, increase the number of sites available, give minimum strain to patients regarding surgical procedures, and offer uneventful healing after removal. The use of titanium miniscrews as an orthodontic anchorage has been reported in clinical case reports, but clinicians hove experienced screw loosening when using such screws. To our knowledge, there are no published reports evaluating the stability of miniscrews. Information about the length of miniscrews used in relation to the location is of some importance, as stability will vary depending on bone quality. The purpose of this study was to evaluate a variety of lengths of miniscrews (diameter: 2mm) which were inserted in maxilla or mandible and to demonstrate in a dog moedl which miniscrew provides fundamental stability in the jaws. 10 mm long miniscrews in the maxilla and 8mm long miniscrews in the mandible showed no clinical mobility and retained their position throughout an 8 weeks force (200g) application. The mucosal condition around the screws was healthy in cases in which miniscrews were inserted in the alveolar bone between the roots and the head of the screws emerged into the attached gingiva. When the force application was terminated, radiographic analysis revealed neither root resorption nor periodontal pathology around the miniscrews that remained stable during the entire treatment period. This study suggests that if titanium miniscrews with adequate length are properly used depending on the location, they provide sufficient stability for orthodontic anchorage.

캔디다균이 분비하는 단백질 분해효소의 순수 분리와 특성 및 교차 항원성

이경호,신운섭,박주영,김수기,박윤선,고춘명 연세대학교 원주의과대학 1995 원주의대논문집 Vol.8 No.1

국내 민간투자(SOC)사업의 효율화 방안에 대한 연구

이호경,김상철,윤준선,백준홍 대한건축학회 2003 대한건축학회 학술발표대회 논문집 - 계획계/구조계 Vol.23 No.1

The purpose of this study is to examine the theoretical concept and practical example of Social Overhead Capital(SOC) project based on development of nation the world. Also, the critical access is to find the way we can develop domestic SOC project underway in private and nationwide. Furthermore, anther access is to propose clearly how to utilize BOT, BTO in financial, technical, CM method focusing on more systematic and effective result.