SHS 공정에 의해 제조된 Mo_xW_1-xSi₂ 발열체의 열화메커니즘

이동원,이상헌,김용남,이성철,구상모,오종민,Lee, Dong-Won,Lee, Sang-Hun,Kim, Yong-Nam,Lee, Sung-Chul,Koo, Sang-Mo,Oh, Jong-Min 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.10

The degradation mechanism of $Mo_xW_{1-x}Si_2$ ultrahigh-temperature heating elements fabricated by self-propagating high-temperature synthesiswas investigated. The $Mo_xW_{1-x}Si_2$ specimens (with and without post-annealing) were subjected to ADTs (accelerated degradation tests) at temperatures up to $1,700^{\circ}C$ at heating rates of 3, 4, 5, 7, and $14^{\circ}C/min$. The surface loads of all the specimen heaters were increased with the increase in the target temperature. For the $Mo_xW_{1-x}Si_2$ specimens without annealing, many pores and secondary-phase particles were observed in the microstructure; the surface load increased to $23.9W/cm^2$ at $1,700^{\circ}C$, while the bending strength drastically reduced to 242 MPa. In contrast, the $Mo_xW_{1-x}Si_2$ specimens after post-annealing retained $single-Mo_xW_{1-x}Si_2$ phases and showed superior durability after the ADT. Consequently, it is thought that the formation of microcracks and coarse secondary phases during the ADT are the main causes for the degraded performance of the $Mo_xW_{1-x}Si_2$ heating elements without post-annealing.

SHS 공정으로 제조된 Mo<SUB>x</SUB>W<SUB>1-x</SUB>Si₂ 발열체의 가속수명시험과 고장분석

이동원(Dong-Won Lee),이상헌(Sang-Hun Lee),김용남(Yong-Nam Kim),이희수(Heesoo Lee),이성철(Sung-Chul Lee),구상모(Sang-Mo Koo),오종민(Jong-Min Oh) 한국전기전자학회 2017 전기전자학회논문지 Vol.21 No.3

고온자전합성과 후열처리 공정으로 MoxW1-xSi₂ 발열체를 제조하였다. MoxW1-xSi₂ 발열체의 신뢰성을 검증하기 위해 가속수명시험을 수행하였으며, 수명시간을 Minitab 프로그램으로 추정하였다. 또한, 가속수명시험 후의 MoxW1-xSi₂ 발열체의 고장분석을 전기적과 구조적 특성으로부터 수행하였다. 그 결과, MoxW1-xSi₂ 발열체의 지배적인 고장 유형은 발열체 내부의 크랙 형성과 SiO₂ 보호층의 박리임을 확인하였다. MoxW1-xSi₂ heaters were fabricated by self-propagating high-temperature synthesis (SHS) process and post sintering process. To validate the reliability of the MoxW1-xSi₂ heaters, the accelerated life test (ALT) was conducted, and then lifetime to MoxW1-xSi₂ heaters was estimated by using Minitab programs. Also, the failure analysis of MoxW1-xSi₂ heaters after ALT was performed through electrical and structural properties. As the results, it was confirmed that the dominant failure mode of MoxW1-xSi₂ heaters is the crack formation in heaters and the delamination of protective SiO₂ layers.

가토에서 일측 요관 부분 및 완전폐색시 신장과 요관의 조직학적 변화

김상현,김용웅,육승모,한동석,노안식,임재성,김홍식,나용길,설종구 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

This study was designed to clarify histologic changes in the experimental rabbit kidney and ureter after unilateral partial or complete ureteral obstruction. A total of 20 adult white rabbits were divided into 4 subgroups in the partial obstruction followed by 2 weeks, the partial obstruction followed by 4 weeks, the complete obstruction followed by 2 weeks, and the complete obstruction followed by 4 weeks. The normal control group was consisted of 5 adult white rabbits. The kidneys and ureters for light microscopy were fixed in 10% neutral formalin, embedded in paraffin and stained with hematoxylin and eosin. Abnormal histologic fingings showed in ipsilateral kidney and ureter of all subgroups(such as dilatation of uriniferous tubule, focal necrosis and desquamation of epithelium, interstitial fibrosis, glomerular congestion, widening of Bowman's space, dilatation of ureter, epithelial cell atrophy or loss, interstitial fibrosis and interstitial inflammation). These findings were most severe in the group of the complete-obstructed ureter for 4 weeks. No significant changes showed in contralateral ureter of all subgroups. The degree of obstruction was severe and period of obstruction was long, the histological changes in ipsilateral side were severe. Despite of changes in ipsilateral side no abnormal findings showed in contralateral side. We suggest that long term experimental investigation of histologic changes in ipsilateral side and compensatory changes in contralateral side have to be studied.

식이섬유 보충용 식품의 섭취에 따른 여성의 비만관련 체구성 요인 및 배변만족도의 변화

임용택,강선영,김재등,김성수,김재우,이충영,김정모 한국스포츠리서치 2004 한국 스포츠 리서치 Vol.15 No.1

The Purpose of this study was to investigate the effect of functional food including dietary fiber supplementation on body composition concerning obesity and defecation satisfaction of women. Twelve young healthy women but had defecation difficulty were participated as a subject. Body weight, %body fat, WHR mesurement and defecation satisfaction questionnaire were performed before and after 2 weeks' supplementation. The results of this study were as follows : First, Body composition concerning obesity such as body weight(p=.0065), % body fat(p =.0004) and WHR(p=.0007) after 2 weeks' functional food including dietary fiber supplementation was decreased significantly. Second, defecation satisfaction functional food including dietary fiber supplementation was increased significantly(p = .0039). This results suggested that functional food including dietary fiber supplementation should be recommended as effective dietary food for persons with obesity and defecation difficulty.

위장질환에 따른 H.pylori 감염빈도와 검사방법의 비교분석

김대현,조재현,금민수,최성곤,이창형,탁원형,권영오,김성국,최용환,정준모 慶北大學校 醫科大學 1997 慶北醫大誌 Vol.38 No.2

목적 : H. pylori가 위장관 질환의 병인에 깊은 관련이 있어 이의 적절한 진단 및 치료가 중요하게 대두되고 있다. 이에 저자들은 소화기 증상을 주소로 내원한 환자들을 대상으로 내시경 검사를 실시하여 H. pylori검출을 위한 CLO검사, IgG 항체검사 및 H&E 염색 등을 시행하여 각 질환별로 H. pylori 감염의 양성율을 알아보고 검사법에 따른 민감도 및 특이도를 그 유용성에 대하여 조사하였다. 대상 및 방법 : 1996 4월에서 8월까지 경북대학교병원에 소화기증상을 주소로 내원한 총 313명의 환자를 대상으로 내시경 검사를 실시하여 H. pylori 검출을 위한 CLO 검사, IgG 항체검사, 조직염색 검사를 실시하였다. 결과 : 전체 대상 환자수는 313명이었고 연령별 분포는 16세부터 80세 까지 다양하였으며 그중40대, 50대, 60대가 각각 69예(22%), 73예(23.3%), 65예(20.8%)로 전체 환자중 66%를 차지하였다. 남녀비는 2.07 대 1로 남자가 많았다. 대상환자의 평균나이는 52±15세였고, 전체 대상환자에서 H. pylori 양성군과 음성군의 평균나이는 각각 50±15세, 54±15세 였고, 궤양환자군에서 H. pylori 양성군과 음성군사이의 평균나이는 각각 49±14.8세, 55±13.8세로 나타났다. 각 질환별분포는 위염이 72명(23%), 십이지장 궤양이 85명(27.2%), 위궤양이 80명(25.6%), 위암이 20명(6.4%), 비궤양성 소화불량이 13명(4.2%), 기타가 43명(13.7%)이었으며, H. pylori 감염 양성율은 위염이 71%, 십이지장 궤양이 86.8%, 위궤양이 58.3%, 위암이 75%, 비궤양성 소화불량이 75%였으며 특히 유문륜 궤양에서는 100%의 양성율을 보였다. 소화성 궤양군과 비궤양군에서의 H. pylori 양성율을 비교해 본 결과 궤양군에서는 73.1%, 비궤양군에서는 72%로 통계학적으로 차이는 없었다(P=0.91). 소화성 궤양환자에서 출혈이 동반된 군과 동반되지 않은 군에서의 H. pylori 양성율을 비교해 본 결과 출혈이 동반된 군에서의 양성율은 54.5%였고, 출혈이 동반되지 않은 군에서는 77.5%의 양성율을 보여 출혈이동반되지 않은 군에서 통계학적으로 유의하게 높았다(P=0.014). 나이에 따른 양성율을 알아본 결과 50세 이하에서는 78.5%였고, 50세 이상에서는 67.5%로서 양성율이 낮았으나 통계학적으로 유의성은 없었다(P=0.052). 각 검사법에 따른 민감도 및 특이도는 전체 환자중에서는 CLO검사가 88.9%, 96.1%, IgG항체검사 90.8%, 58.5%, H&E 염색검사 86.9%, 79.2%로서 민감도는 비슷하게 나왔으나 CLO검사는 상대적으로 특이도가 다른 검사법에 비해 높았다. 궤양군에서의 CLO검사의 민감도와 특이도는 92.0%, 95.6%였고, 비궤양군에서의 민감도와 특이도는 84.3%, 96.8%로서 비궤양군에서는 CLO검사의 민감도는 약간 낮았다. 나이에 따른 CLO 검사의 민감도 및 특이도는 50세 이하에서는 91.5%, 93.1% 였고, 50세 이상에서는 86.3%, 97.9%로서 50세 이상에서는 상대적으로 CLO검사의 민감도가 낮았다. 결론 : 본 연구에서는 위장질환에 따른 H. pylori 양성율을 알아보았는데, 다른 보고에서 처럼 높게 나왔으며, 진단 방법으로 사용한 CLO검사, IgG항체 검사, 조직염색검사 등은 모두 비교적 높은 예민도를 나타냈고, 그중 CLO검사가 간편하고 경제적이라는 면에서 임상적으로 유용한 검사로 여겨지나 상대적으로 CLO검사의 민감도가 낮은 비궤양성 질환과 50세 이상의 환자군에서는 CLO검사 외에 다른 검사방법을 병행함으로써 H. pylori의 진단율을 높일 수 있을 것으로 사료된다. Background: Gastric colonization by Helicobacter. pylori is common among patients with peptic ulcer and gastritis. And various diagnostic tests are available in confirming H. pylori infection. The aim of this paper is to estimate the prevalence of H. pylori infection in Gastroduodenal disorders and compare the sensitivity and specificity of the most widely available tests. Methods: A total of 313 patients were tested for H. pylori infection by IgG Ab, CLO test and H&E stains. Results: The prevalence of H. pylori infection was significantly higher in duodenal ulcer(86.8%) than in gastric cancer(75%), gastritis(71%) and gastric ulcer(58.3%)(P=0.009). The sensitivity and specificity of each test was as follows: CLO test(88.9%, 96.1%), IgG Ab test(90.8%, 58.5%), H&E stain(86.9%, 79.2%). Sensitivity of CLO test in peptic group was 92.0%, whereas in non-peptic group, it was 86.3%. Sensitivity of CLO test in age under 50 was 91.5%, that over 50 it was 86.3%. Conculsions: There is a strong association between H. pylori and gastrointestinal disorders. CLO tests have relatively high sensitivity and specificity, especially in peptic group and younger age(below 50 yr)group. But in those patients in which CLO tests are less sensitive (age>50 or non-peptic group), more than one test may be necessary to diagnose the presence of the organism.

표재성 방광암에서 Bacillus Calmette-Guerin 방광 내 주입요법 : 장기적 추적결과 Long-term Follow up Results

김용웅,왕세환,육승모,한동석,노안식,나용길,설종구 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

To evaluated the results of long-term follow up of superficial bladder cancer patients who were treated with transurethral resection and intravesical BCG therapy. Between April 1989 and December 1997, 65 patients with superficial bladder cancer were treated with TUR-B(Transurethral resection of bladder tumor) and intravesical BCG instillation, and follow-up was performed for 5 years longer, and the mean follow-up duration was 82 months. Of 65 patients, pathologic stage were Ta in 17 cases and T1 in 48 cases and grade were G Ⅰ in 22 cases, G Ⅱ in 35 cases and G Ⅲ in 8 cases. The tumor recurred in 22(33.8%) at the median of 21.8 months and the tumor progressed in 9(13.8%) at the median of 20.8 months. Most of the recurrences and progression were within 3 year(838 and 77%). Progression is more likely in higher grade(G Ⅱ, G Ⅲ) and higher stage(T1). The complete response rate after first and second courses of BCG therapy were 53% and 73% and the 5 and 10 year disease specific survival rates were 89.5 and 78% respectively. The complete response rate after first and second courses of BCG therapywere 53% and 73%. Most of recurrences and progressions were within 3 years of the BCG therapy, but some cases occured after 5 years. Therefore, close long-term follow up is needed.

지방분권과 지역언론 활성화방안 연구

김덕모,조용철 호남대학교 2005 호남대학교 학술논문집 Vol.26 No.1

According to the launching of participation government, decentralization of power and balabced development of land are uprised as a vital national agenda and diverse discussions are under way actively. Meanwhile evils of localism and Seoul-Metropolitan area based national development strategies put the local far away. So the sense of alienation of local reached the top of a boiling pot. The government of Ro Moo Hyun's plan for decentralization of power and balabced development of land cast a vision of revolutional change in the field of all arena such as politics, economy, society and culture. For that reason, local newspaper (which is the locomotive of local development) is said that he has to be changed more dynamically than ever before. Sprouting of colorful discussions about decentralization of power and measurements of the vitalization of local newspaper after the launching of participation government attribute to that stream. These discussions include institution practices which is accumulated during so many years, changes of media environment and awakening of local pressmen and residents. Now local press is cinfronted with serious agony whether they are making a role of agenda setting for decentralization of power and balanced development of land. In this respects, Gwangju-Jeonnam based newspaper's first page change (top news of each news paper is different from another newspaper) is accepted as positive which reflect the diversitied of society, But critic criticised megative aspects that diversity does not reflect many color of market of public opinion but promotes the disintegration of public opinion. This study aims at trying to find a solution to a problem of what is the better way and measurement to reform local newspaper. To find a solution to a problem, bibliographic research and statistical analysis approach are used here.

창의력 개발을 위한 초등실과 교수·학습자료의 개발

김용익,박행모,방기혁 光州敎育大學校 初等敎育硏究所 2002 初等敎育硏究 Vol.17 No.-

The purpose of this study was to develop instructional materials for the development of creativity through practical arts subject. This study was carried out mainly through literature review. The concept of creativity was organized as creativity domain(X axis) including cognitive and affective one, creativity dimension(Y axis) including historical creativity and psychological creativity, and the viewpoint of creativity level(Z axis) including novelty and appropriateness. In the future, creativity education in practical arts subject should be more emphasized because of creativity development education through practical arts subject was more effective than through other subjects. Most of preceding researches related to creativity in practical arts subject dealt with instructional model and guidance for creativity rather than development of various instructional materials. This study explored Treffinger's instructional model which was composed of difficulty finding, data finding, problem finding, solution finding, and acceptance finding. And, Instructional guidance plan related to 'woodworking lesson' was made at base of the model. Besides, other instructional materials for the improvement of creative thought was concretely presented. Finally, it was suggested that more instructional materials should be developed and a test for effectiveness of such a creative program should be made afterward.

만성 승모판 패쇄부전증 환자에서의 안지오텐신 전환효소 억제제의 장기 투여 효과

김대희,이명묵,이해영,조현재,박승정,서재빈,서정원,양한모,윤창환,조상호,이준희,김용진,김명아,손대원,오병희,박영배 대한순환기학회 2004 Korean Circulation Journal Vol.34 No.2

중추성 요붕증으로 발현된 랑거한스세포 조직구증식증 1례

김준성,윤원상,김근모,최영권,박기원,김병희,유용상 대한소아내분비학회 2004 Annals of Pediatirc Endocrinology & Metabolism Vol.9 No.1