나사산이 있는 관이음의 효과적인 해석모델의 개발

임중연,이호용,고광일 東國大學校 1996 東國論叢 Vol.35 No.-

This paper is concerned with and efficient model for the structural analysis of threaded connections which is used to assemble the tubular connections such as pipes. Advanced mechanics has been used to develop the model which yields acceptably accurate solutions for stresses when compared to other methods such as experimental or finite element analysis procedures. Beam-on-elastic-foundation equations are used to compute stresses due to assembly of the connection while bolt-nut equation and Lame' equation are used for axial loads and pressures. Numerical results show that our model is computationally efficient and valid in terms of stress distribution for make-up. The current model can provide the quick and inexpensive analysis tools to the production engineer with reasonable accuracy.

16S rDNA 클론 library 제작 및 핵산염기서열 결정을 통한 교정용 미니임플랜트 주위 열구의 세균 동정

임성훈,김광원,유소영,국중기,장영일 대한치과교정학회 2006 대한치과교정학회지 Vol.36 No.4

교정치료 시 고정원으로 사용되는 교정용 미니임플랜트는 가동성 점막인 치조점막 부위에 식립해야 하는 경우가 많은데, 이때 미니임플랜트 주위 연조직의 증식을 동반한 염증이 빈번히 발생한다. 본 연구에서는 치조점막에 식립하여 연조직 증식이 발생된 미니임플랜트 주위의 세균총과 동일 환자의 인접한 건강한 치은 열구의 세균총을 비교하고자 하였다. 이를 위해 7명의 환자를 대상으로 하악 구치부의 치조점막에 식립하여 연조직 증식이 발생한 미니임플랜트 및 이에 연결된 결찰선 주위 열구의 세균막과 미니임플랜트에 인접한, 치은 염증이 없는 제2대구치의 치은열구의 세균막을 멸균된 paper point로 채취한 후, 16S rDNA 클론 library 제작 및 핵산염기서열 분석법을 이용하여 세균을 동정하여 비교하였다. 실험 결과 미니임플랜트 주위 열구로부터 304개의 16S rDNA 클론을 얻었으며, 치은열구로부터 238개의 16S rDNA 클론을 얻었다. 클론의 9.2%에 해당하는 24종의 세균들은 미니임플랜트 주위 열구에서만 검출되었고, 이들은 Haemophilus aphrophilus, Sphingomonas species, Capnocytophaga species, Prevotella melaninogenica, Lachnospiraceae species, Porphyromonas species, Neisseria flava 등이었다. 전체 클론의 80.4%에 해당하는 29종의 세균들은 미니임플랜트 주위 열구 및 건강한 치은 열구 모두에서 검출되었다. 이들 중 특히 미니임플랜트 주위에서 더 많은 클론이 분리된 세균들은 Prevotella species, Atopobium rimae, Veillonella species, Streptococcus intermedius/constellatus, Streptococcus salivarius 등이었다. 향후 연구에서는 본 연구에서 치조점막에 식립한 미니임플랜트 주위에서 검출된 세균들이 염증을 일으키거나 악화시킬 수 있는지를 밝히는 것이 필요하며, 이를 바탕으로 치조점막에 식립한 미니임플랜트 주위의 연조직 염증을 줄일 수 있는 방법을 찾는 것이 바람직하다. Objective: The purpose of this study was to compare the bacterial flora at the peri-implant sulcus of the orthodontic mini-implant placed in the alveolar mucosa with the bacterial flora at the adjacent healthy gingival sulcus. Methods: Two plaque samples from 7 patients were collected by inserting paper points into the sulcus between the mini-implant and ligature wire connected to the mini-implant head and inflamed alveolar mucosa, and from the gingival sulcus of a healthy tooth adjacent to the mini-implant. Results: Using 16S rDNA clone library, the 24 kinds of bacteria including Haemophilus aphrophilus, Sphingomonas species, Capnocytophaga species, Prevotella melaninogenica, Lachnospiraceae species, Porphyromonas species, Neisseria flava were identified only from the sulcus around the mini-implant. These bacteria constituted only 9.2% of total clones, and the bacteria identified from both the sulcus around mini-implants and the gingival sulcus constituted 80.4% of total clones. Of these bacteria, clones of Prevotella species, Atopobium rimae, Veillonella species, Streptococcus intermedius/constellatus, Streptococcus salivarius were more frequently isolated from the peri-implant sulcus. Conclusion: This study suggests that a broad epidemiological study is needed to find causative bacteria which induce inflammation from the peri-implant sulcus.

녹차 및 결명자 추출물의 교정용 브라켓과 치면 사이의 경계부에서 분리된 mutans streptococci에 대한 항균작용

임성훈,서정순,윤영주,김광원,유소영,김화숙,국중기,이병래,차종희,박재윤 대한치과교정학회 2003 대한치과교정학회지 Vol.33 No.5

본 연구는 치아우식증에 관련된 Mutans streptococci 표준균주 및 임상분리 균주의 성장억제를 유도할 수 있는 천연 생약추출물을 검색하기 위하여 실시되었다. 녹차추출물은 CHMC-2032를 사용하였으며, 결명자 추출물은 50% 에탄올을 이용하여 얻었다. 이들 추출물의 Mutans streptococci 표준균주 및 교정환자들에서 브라켓과 치면 사이의 경계부에서 분리된 각각 10 균주씩의 S. mutans 및 S. sobrinus에 대한 최소성장억제농도를 액체배지 희석법으로 구하였다. 그 결과 CHMC-2032의 S. mutans 및 S. sobrinus의 표준 균주, S. sobrinus의 대부분 임상분리 균주에 대한 최소성장억제농도는 5 mg/ml이었다. 그러나 결명자 추출물에 의한 S. mutans 및 S. sobrinus에 대한 세균 성장억제 효과는 미미하였다. 본 연구 결과 치아우식증의 예방적 측면에서 결명자차보다는 녹차를 마시는 것이 유리하며, CHMC-2032를 이용하여 구강양치용액을 제조하여 사용할 경우 교정환자를 포함하여 대부분의 사람에게서 치아우식증 예방 효과가 있으리고 추정된다. Mutans streptococci is the major causative factor in dental caries. Especially, orthodontic patients with fixed appliance are a risk group for dental caries. Because fixed appliances attached on teeth may change the environment of dental plaque, the enamel decalcification or dental caries around the bracket and band is a major side effect of orthodontic treatment. The aim of this study was to search plant extracts that have antimicrobial effect on mutans streptococci. Seed-extract of Casio tora were prepared with ethanol and CHMC-2032, the leaf-extracts from Camellia sinensis extract, was obtained extract, 2 type strains and 20 clinical isolates of mutans streptococci isolated from the interface between orthodontic brackets and tooth surfaces in the orthodontic patients were used in this study. The minimal inhibitory concentration of CHMC-2032 was 5 mg/ml on the S. mutans KCTC 3065, S. sobrinus KCTC 3088, and 8 clinical isolates of S. sobrinus. However, there was no antibacterial effect of seed-extract of C. tora on mutans streptococci. These data suggest that green tea may be more effective than the tea prepared from C. tora in the prevention of enamel decalcification or dental caries around brackets.

炭水素 元素分析에 있어서 檢體의 充塡 位置에 基因하는 誤差에 對한 硏究

林中基 成均館大學校 1962 論文集 Vol.7 No.-

To reduce the errors, in the microdetermination of carbon and hydrogen by the electrical automatic combustion apparatus, measured the errors due to the positions' of sample in the carbon and hydrogen combustion tube. The samples are used Glucose, Acetanilide, Phenacetin and Diazoamino-benzene. Experimented positions of samples were 3cm, 5cm, 7cm, 8cm and 9cm, from the front edge of the long stationary burner. Every samples determined twice and took the averages of measured carbon and hydrogen's values of each samples. In this experiment, it was found that the most suitable position of sample in the carbon and hydrogen combustion tube is 8cm from the long stationary burner.

L-THIA/NPS to Assess the Impacts of Urbanization on Estimated Runoff and NPS Pollution

임경재,비니드엥겔,김영석,최증대,김기성 江原大學校 附設 環境硏究所 2003 環境硏究 Vol.20 No.-

The land use changes from non-urban areas to urban areas lead to the increased impervious areas, consequently increased direct runoff and higher peak runoff. Urban areas have also been recognized as significant sources of Nonpoint Source (NPS) pollution, while agricultural activities have been known as the primary sources of NPS pollution. Many features of the L-THIA/NPS GIS, L-THIA/NPS WWW system have been enhanced to provide easy-to-use system. The L-THIA model was applied to the Little Eagle Creek (LEC) watershed in Indiana to evaluate the accuracy of the model. The L-THIA/NPS GIS estimated yearly direct runoff values match the direct runoff separated from U.S. Geological Survey stream flow data reasonably. The R2 and Nash-Sutcliffe values are 0.67 and 0.60, respectively. The L-THIA estimated runoff volume and total nitrogen loading for each land use classification in the LEC watershed were computed. The estimated runoff volume and total nitrogen loading in the LEC watershed increased by 180% and 270% for the 20 years. Urbanized areas - "Commercial", "High Density Residential", and "Low Density Residential" of the LEC watershed made up around 68% of the 1991 total land areas, however contributed more than 92% of average annual runoff and 86% of total nitrogen loading. Therefore, it is essential to consider the impacts of land use change on hydrology and water quality in land use planning of urbanizing watershed.

어음 抗辯制限論

林重鎬 中央大學校 法學硏究所 2002 法學論文集 Vol.26 No.1

韓國의 輸出支援制度에 관한 硏究 : WTO體制를 中心으로 Focus on WTO

林龍澤,金重根 군산대학교 지역개발연구소 1994 地域開發硏究 Vol.6 No.-

The export support system which is classified roughly into export financing system and export tax system has been played an important part in increasing competitiveness of exports since 1960's. As Uruguay Round(UR) come to an amicable settlement in 1994, export support system should be modified to obey new international economic rules(WTO). In conclusion, export financing system and export tax system which are decided to prohibited subsidies(red subsidies) should be altered to actionable subsidies(yellow subsidies) or non-actionable subsidies(green subsidies) in WTO. Export credit insurance system and customs drawback system which fall into non-countervailing subsidies(green subsidies) should be improved in the aspect of their system and operation to support export.

Melandrin의 방향족 유도체 합성에 관한 연구

임중기,이강노,함원훈,이상인 성균관대학교 약학연구소 1992 成均藥硏論文集 Vol.4 No.1

Melandrin, as a possible phytoalexin, which is expected to have the various pharmacological activities; antibacterial, antifungal and antiviral activity, was isolated in 1987 by Woo from Melandrin firmum (Caryophyllaceae). The synthesis of melandrin derivatives has been accomplished by the reaction of 5-hydroxy anthranilic acid ethyl ester with acid chlorides and then by hydrolysis of ethyl ester.

수동변속기 트랜스미션케이스의 피로파괴 분석

임중연 동국대학교 산업기술연구원 1996 산업기술논문집 Vol.7 No.-

본 논문은 로드-로드 스펙트럼 분석기법을 적용하여 자동차 트랜스미션케이스의 피로파괴분석을 다룬 것이다. 수동변속기의 트랜스미션케이스는 다양한 주기적 하중을 받고 있으며 결과적으로 케이스표면에 가끔 균열이 발생되기도 한다. 본 연구에서는 지지방식이 엔지 3점지지 방식에서 트랜스미션 3점지지 방식으로 바뀌면서 발생하는 균열의 원인분석에 관한 것이다. 트랜스미션 3점지지 방식은 내구시험중 드레인플러그 부위에서 균열이 조기발생되었다. 이러한 원인을 정량적으로 분석하기 위하여 1 사이클 내구시험동안 각각의 지지방식에 대하여 누적손상량을 계산할 수 있는 실험 및 컴퓨터를 이용한 분석이 병행되었다. 결과적으로 트랜스미션 3점지지 방식이 엔진 3점지지 방식보다 트랜스미션케이스의 드레인플러그부위에 더 많은 손상을 준다는 것이 판명되었다. This paper is concerned with the fatigue fracture analysis of the automobile transmission case by applying road-load spectrum analysis technique. The manual transmission case receives various cyclic load and sometimes results in crack on the surface of case. Our study investigates the crack occurrence of new model which employes the three-point mounting support on transmission while previous one used three-point mounting support on engine. The crack has been detected near the drain plug for the type of three-point mounting support on transmission during the early stages of endurance test. To find out the cause quantitively, experiment and computational analysis have been carried out to calculate the cumulative damage for both support types during one cycle endurance test. The numerical results show that the type of three-point mounting support on transmission gives larger damages on the surface of transmission case than that of three-point mounting support on engine.

Piperine 誘導體[5-(3-methoxy-4-hydroxyphenyl)-2,4-pentadienoic acid amides]의 合成 硏究

林中基,咸元勳,崔然喆 성균관대학교 약학연구소 1990 成均藥硏論文集 Vol.2 No.1

Abstract-Some 5-(3-methoxy-4-hydroxyphenyl)-2,4-pentadienoic acid amides were synthesized for searching new anticonvulsant agents. The amides could be synthesized by condensation of protected vaniline with crotonic acid amides in the presence of sodium amide. A MOM Ether(methoxymethyl ether) was used to protect one phenolic hydroxyl group of vaniline. MOM Ether was selectively cleaved on exposure to 1 : 1 THF-6N hydrochloric acid.