Coupling of Creep Deformation Mechanism Equations and Dynamic Recrystallization Kinetics for the Calculation of Processing Maps for Metallic Alloys

Woo‑Jin Kim,Hee‑Tae Jeong 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.3

In the present work, kinetic equations of dynamic recrystallization and high-temperature deformation mechanism equationswere coupled to calculate and construct processing maps for metallic alloys in 2D and 3D. The validity of this method wasconfirmed for selected materials (Mg and Fe alloys) by comparing the calculated processing maps with those constructedbased on experimental data. The effect of the initial grain size on the processing maps was predicted. The proposed analysismethod is innovative because the processing map for a material of interest can be calculated as a function of strain rate,temperature and strain under any deformation condition once the dynamic recrystallization kinetics and the creep deformationequations for the material are known. Furthermore, the proposed method can provide information regarding the ratecontrollingcreep deformation mechanism and microstructural evolution at any location on the processing maps.

古代哲學思想이 東醫病理學에 미친 影響

鄭遇悅,李鎭弘,鄭鉉雨 대한동의병리학회 1997 동의생리병리학회지 Vol.11 No.2

學問은 어느시대를 막론하고 그 胎動當時의 時代的·社會的·政治的·思想的 背景속에서 발전한다. 韓醫學 또한 이러한 背景속에서 발전되었다. 醫學은 환자의 질병을 치료하기 위한 학문으로 인체의 陰陽平衡狀態를 建康이라 정의한다면 疾病이란 인체의 陰陽失調(陰陽偏盛偏衰)라 말할 수 있다. 이러한 疾病을 유발시키는 원인과 그 원인으로 인하여 인체에 나타나는 각종 症狀들에 대 病理機轉을 밝히기 위해서는 韓醫學의 胎動當時의 배경들을 연구할 필요성이 있다하겠다. 그리하여 《黃帝內徑》이 著述되기 前 古代 哲學思想이 韓醫學 理論定立-東醫病理學-에 어떠한 영향을 미쳤는가를 고찰하기 위하여 현재 출간되고 있는 韓醫學 서적을 중심으로 고대 서적들을 참고하여 陰陽五行論과 精氣神論의 형성과정을 살펴보았다. 그 결과 古代 哲學思想인 敬天崇祖思想과 陰陽五行思想, 精氣神學思想들이 그 시대의 學術的 思想을 반영하듯 韓醫學에서도 역시 主流를 이루고 있었고, 이를 바탕으로 病因論도 고찰할 수 있었다. 즉, 韓醫學의 認識方法인 由果析因ㆍ類比推理ㆍ以象測臟 및 以表測裡의 方法을 통하여 疾病의 原因과 病理機轉등을 밝혔는데, 이것이 바로 그 時代的ㆍ學術的 背景에 따른 것임을 알 수 있었다. Because a time, society, politics, thought bring about effect learning, formation of oriental medicine is formed this background also, Before《Nae-Kyung》was written to study numerous effect antiquity philosophically on oriental medicine pathology investigated books from antiquity to presently. The result were as follows. 1. Before the Chroicles of Lu witch docters acted. 2. In the Chroicles of Lu, philosophically were "the Uem-Yang-O-Haeng theory", "Jeong-Chi-Shin theory" and "Chen-Yin-Shang-Ueong theory" etc. 3. This theories were effected formation of oriental medicine(the cause of a disease, course of disease, pathologic change, therapy etc)

Coating with boron nitride on SiC fiber using atomic substitution

Woo‑Seong Tak,Jin‑Uk Hwang,Young‑Keun Jeong,Woo‑Sik Kim 한국세라믹학회 2020 한국세라믹학회지 Vol.57 No.2

To increase the mechanical properties of ceramic matrix composite, it is important that formation of lubricant layer for crack deflection between matrix and fiber. Therefore, we fabricated uniform boron nitride (BN) lubricant layer using atomic substitution method. Silicon carbide (SiC) fiber surface was modified with amine groups using (3-amonipropyl)triethoxysilane to coat SiC fiber with BN as a solid lubricant. Then, surface was coated with graphene oxide (GO). Boric acid powder was supplied to the GO-coated fibers and the samples were heat-treated at 1200–1400 ℃ under N2 and NH3 atmospheres. An uniform BN layer could be coated on SiC fiber with 10 nm-1.11 μm. Crystallinity and thickness of BN layer could be controlled by reaction temperature. It was also confirmed that crystalline BN formed under process conditions of higher than 1400 ℃.

한국인 직무 스트레스 측정도구의 개발 및 표준화

장세진,고상백,강동묵,김성아,강명근,이철갑,정진주,조정진,손미아,채창호,김정원,김정일,김형수,노상철,박재범,우종민,김수영,김정연,하미나,박정선,이경용,김형렬,공정옥,김인아,김정수,박준호,현숙정,손동국 大韓産業醫學會 2005 대한직업환경의학회지 Vol.17 No.4

Background and Purposes: Over the past three decades, numerous studies performed in Korea have reported that job stress is a determinant risk factor for chronic diseases and work disability. Every society has its own culture and occupational climate particular to their organizations, and hence experiences different occupational stress. An occupational stress measurement tool therefore needs to be developed to estimate it objectively. The purpose of this study is to develop and standardize the Korean Occupational Stress Scale (KOSS) which is considered to be unique and specific occupational stressors in Korean employees. Subjects and Methods: Data were obtained from the National Study for Development and Standardization of Occupational Stress (NSDSOS Project: 2002-2004). A total of 12,631 employees from a nationwide sample proportional to the Korean Standard Industrial Classification and the Korean Standard Occupational Classification were administered. The KOSS was developed for 2 years (2002-2004). In the first year, we collected 255 items from the most popular job stress measurement tools such as JCQ, ERI, NIOSH and OSI, and 44 items derived from the a qualitative study (depth interview). Forty-three items of KOSS, in the second year, were retained for use in the final version of the KOSS by using Delphi and factor analysis. Items were scored using conventional 1-2-3-4 Likert scores for the response categories. Results: We developed eight subscales by using factor analysis and validation process: physical environment (3 items), job demand (8 items), insufficient job control (5 items), interpersonal conflict (4 items), job insecurity (6 items), organizational system (7 items), lack of reward (6 items), and occupational climate (4 items). Together they explained 50.0% of total variance. Internal consistency alpha scores were ranged from 0.51 to 0.82. Twenty-four items of the short form of the KOSS (KOSS-SF) were also developed to estimate job stress in the work setting. Because the levels of the subscales of occupational stress were gender dependent, gender-specific standard norms for both the 43-item full version and the 24-item short form using a quartile for the subscales of KOSS were presented. Conclusion: The results of this study suggest that KOSS might be an appropriate measurement scale to estimate occupational stress of Korean employees. Further and more detailed study needs to be conducted to improve the validity of this scale.

황기桃紅湯이 Endotoxin으로 유발된 白鼠의 血栓症에 미치는 영향

田炳薰,李鎭弘,鄭鉉雨,禹元洪,鄭遇悅 대한동의병리학회 1993 동의생리병리학회지 Vol.8 No.-

연구배경 : 최근의 死亡率중에 腦血管系疾患이 차지하고 있는 比率이 대단히 높기 때문에 氣와 血의 이론적 관계인 "氣爲血之帥, 氣行則血行." 의 관점하에서 腦血管系疾患중의 하나인 血栓病을 동의학적 병리론에 의거하여 "瘀血"의 범주에 속할 것으로 사료되기 때문에 補氣之劑인 황기를 君藥으로하고 活血祛瘀之劑인 桃仁과 紅花를 加하여 실시하기로 하였다. 그리하여 본 연구가 임상에서 血栓症治療에 應用할 수 있는지를 考察하고, 작게는 東醫學 發展의 이론적 뒷받침이 되었으면 하는 바램에서 시행하였다. 방법 : 황기도홍탕이 1첩분량(318.75g)을 100ml로 減壓濃縮하여 0.2mg/kg의 endotoxin을 試料投與 1시간 후에 白鼠의 尾靜脈에 注入하고 4시간이 경과되면 urethane 痲醉下에서 心臟採血 하였다. 결과 : 血小板數와 FDP는 對照群에 비하여 增加 또는 減少되었지만 有意性은 나타내지 않았다. 그러나 prothrombin time과 fibrinogen량은 對照群에 비하여 有意性있게 短縮 또는 增加하였다. 결론 : 황기도홍탕이 endotoxin으로 誘發된 白鼠의 血栓症에 미치는 影響은 有意한 것으로 나타났다. 그렇기 때문에 黃?桃紅湯이 腦血管疾患 뿐만 아니라 瘀血性疾患에 임상적으로 응용하면 보다 높은 치료효과를 거두리라 思料된다 This study was performed to investigate the effect of Whangkidohongtang(황기도홍탕) on the intravascular coagulation induced by endotoxin in rats. The intravascular coagulation was induced by injecting endotoxin in the caudal vein of rats. And these rats were treated with extract of Whangkidohongtang(황기도홍탕)1.0ml/200g (GroupⅠ) and Whangkidohongtang(황기도홍탕) 2.0ml/200g (groupⅡ), which were administered orally. Then, the number of blood cells, platelets, concentration of prothrombin time, fibrinogen and FDP(fibrin-fibrinogen degradation products) were measured. The following results were obtained : 1. The number of platelets increased in the GroupⅡcompared with the control group, but it is not significant. 2. The prothrombin time was shortened significantly in the GroupⅡcompared with the control group. 3. The concentration of fibrinogen increased significantly in the trial group compared with the control group. 4. The degree of concentration of FDP decreased significantly in the trial group compared with the control group, but it is not significantly. According to the above results, it is considered that Whangkidohongtang(황기도홍탕) has the significant effects on thrombosis. Therefore, Whangkidohongtang(황기도홍탕) seems to be applicable to the diseases related to thrombosis.

오리부산물과 한약재를 이용한 추출액의 영양성분 및 중금속 노출에 대한 피해 완화 효과 : (Ⅱ) 중금속 노출에 대한 오리추출액의 피해 완화 효과 (Ⅱ) Damage Mitigation Effects on Heavy-metals Exposure of Peking-Duck By-Product Extracts

한종현,이우진,조성균,이미정,정미란,전정우,김운영,박성혜 동아시아식생활학회 2003 동아시아식생활학회지 Vol.13 No.4

This study was performed to investigate the effects of peking-duck extracts added with medicinal herbs(DJ) on the intoxication of heavy metals (Hg, Pb, Cd, As) in rats. Sprague-Dawley rats weighing 150±15g, were randomly assigned to 5 groups: basal diet only in normal control group(NCG); basal diet and heavy metals without DJ injection in heavy metal control group(HMC); basal diet, heavy metals and DJ(3㎎/㎖) injection in heavy metal low duck juice group(HMLD), basal diet, heavy metals and DJ(30㎎/㎖) injection in heavy metal middle duck juice group(HMMlD); basal diet, heavy metal and DJ(300㎎/㎖) injection in heavy metal high duck juice group(HMHD). Hg and As was injected by 50ppm and Cd and Pb by 25ppm for 17days. Also DJ oral feeding was conducted for 28days. The result of this study were as follows: Food intake and body weight gain in heavy metal administered groups were lower than those of NCG. Liver, kidney and testis weights were not significantly different among 5 groups. GOT, GPT and BUN activities were significantly reduced in DJ treated groups as compared to HMC. DJ showed the suppressing effect on the accumulation of Hg, Pb and Cd in serum, liver and kidney. Fecal Hg and Cd excretions increased with DJ feeding. The results suggested that DJ may have some protective effects on Hg, Cd and Pb intoxication by reducing the accumulation m tissues and increasing excretion. This study also showed the effective way of using duck-extract and its application to the oriental medicine.

서울의 Penicillinase Producing Neisseria Gonorrhoeae 발생빈도(1994)

김재홍,안진균,정성재,김영태,김중환,김시영,이석종,이홍렬,서호석,김경훈,권혁진,정우권,고우석,이용석,안필수,오준규,오용섭 대한화학요법학회 1996 대한화학요법학회지 Vol.14 No.1

Background : In recent years gonorrhoea has been panendemic and remains one of the most common Sexually Transmitted Diseases in the world, especially in developing countries. Objective & Method : For the detection of a more effective therapeutic regimen and assessing the prevalence of Penicillinase Producing Neisseria Gonorrhoeae(PPNG), Ive have been trying to study the patients who have visited the VD Clinic of Choong-Ku Public Health Center in Seoul since 1980 by means of the chromogenic cephalosporin method. Results : In 1994, 168 strains of N. gonorrhoeae were isolated, among which 109 (64,9% ) were PPNG. Conclustion : Our results suggests that the prevalence of PPNG in Seoul is still increasing.

당뇨병 백서의 간세포에서 Glucokinase 활성도 및 유전자 발현에 대한 인슐린의 영향

강성이,팽정령,서광식,안규정,우정택,김성운,양인명,김진우,김영설,김광원,최영길 경희대학교 유전공학연구소 1993 遺傳工學論文集 Vol.5 No.-

목적 당대사의 조절 상태에 따른 생체 변화를 분자 수준에서 이해하고자 식이 조건을 달리한 정상 백서와 화학적으로 유도된 당뇨병 백서의 간조직에서 혈당수준과 인슐린치료 정도에 따라 나타나는 글루코키나제 활성도 및 유전자 발현을 분석하였다. 방법 스트렙토조토신 정맥투여 후 당뇨병의 유발을 확인하고, 인슐린을 1일 3회 3일간 복강내로 투여하여 상태를 안정시킨 후, 인슐린 투여군은 인슐린 투여 6시간이내에 그리고 인슐린 비투여군은 24시간 후 단두하여 채혈하고 복강을 열어 간조직을 채취하였다. 채취한 간조직에서 글루코키나제 활성도는 인산화된 포도당에서 NADH의 형성을 형광분광계로 측정하였으며, 글루코키나제 유전자 mRNA발현은 Northern 분석법을 이용하였다. 성적 정상 백서에서 공복상태와 식이를 섭취한 경우에 간조직의 글루코키나제 효소의 활성은 차이가 없었으나, 글루코키나제 유전자 mRNA 발현은 증가되었다. 당뇨병이 유발된 백서의 간조직에서 글루코키나제 효소의 활성 및 글루코키나제 유전자의 mRNA 발현은 정상 백서에 비하여 낮았다. 인슐린 투쳐 후 글루코키나제 효소의 활성 및 글루코키나제 유전자의 mRNA 발현이 증가되었고, 특히 혈당이 정상화된 경우에서 글루코키나제 유전자의 mRNA 발현이 증가도었다. 결론 인슐린에 의한 간조직에서 글루코키나제 효소의 활성 및 글루코키나제 유전자의 mRNA을 증가를 볼수 있었다. 당뇨병 백서에서 인슐린 투여 후에 혈당조절이 안된 경우 간조직의 글루코키나제 유전자의 mRNA 발현이 증가가 없는 것으로 보아 글루코키나제 mRNA의 발현에는 인슐린 이외의 다른 요소가 관여할 것으로 생각된다. The liver-specific hexokinase isoenzyme, referred to as glucokinase, is thought to play a key reglulatory role in hepatic glucose metabolism. The glucokinase gene is, therefore, of interest both because of its tissue-specific expression and because of the several regulatory processes that can be analyzed. The level of hepatic glucokinase activity appears to be determined essentially by regulation of the rate of enzyme synthesis, with insulin playing a leading role as an inducer. We investigated the role of insulin for the induction of glucokinase in the liver of diabetic rats. Experimental diabetes was induced by injection of streptozotocin 7 days before the experiment. Regular insulin was given by three days intraperitoneal injection at 8-h interval. The glucokinase mRNA in the liver was estimated by Nothern blot assay, as well as by fluorometric enzyme activity assay. Glucokinase activity was not reduced in the liver of normal fasting rats as compared to normal fed rats. And glucokinase activity was reduced in the liver of diabetic rats as compared to normal rats. In diabetic rats treated with insulin, glucokinase enzyme activity were increased. But glucokinase mRNA expression was only increased in normoglycemic diabetic rat with treated with insulin as compared to hyperglycemic rat. These data indicate that insulin stimulates hepatic glucokinase enzyme activity and mRNA expression. But other hormonal or metabolic factors may be contribute to regulation of glucokinase mRNA expression.

혈액 투석 환자에서 중심정맥 협착에 대한 스텐트 삽입술 : Wallstent Placement

임대승,노상필,이유선,정승현,김보영,이정우,강정아,김정희,이민수,정준용,최시완,정진옥,성인환,이강욱,신영태 충남대학교 의과대학 의학연구소 2002 충남의대잡지 Vol.29 No.1

Stenosis of central vein is a common complication arising after percutaneous subclavian vein catheter insertion performed for temporary vascular access in chronic renal failure patients undergoing hemodialysis. There are several treatment methods for the condition like percutaneous angioplasty(PTA), stent insertion, and surgery, but recent trend is toward PTA and stents. Among the patients diagnosed with chronic renal failure from March 1993 to May 2002 and undergoing hemodialysis through AV fistula, the 14 Patients in whom central vein stenosis arose were selected for the study. A total of 28 percutaneous interventions(5 PTA and 23 stent placement) were performed, and restenosis rate and the time taken till the restenosis in de novo lesions and instant lesions were compared. All 28 cases were operated successfully. The 14 cases that received both anigioplasty and stent placement initially. (de novo lesion : 14 cases), Among the 10 cases with de novo lesion that followed up more than 1 year, 3 cases are currently undergoing hemodialysis without restenosis, and the remaining 7 cases have recurred stenosis with the mean time to restenosis of 10.9 months. In the 7 cases in whom stenosis recurred, 11 interventions were done(instent lesion: 11 cases). 4 of these were using only ballon angioplasty with 100% restenosis rate and the mean time of 3 months until restenosis. The remaining 7 cases were using both balloon angioplasty and stent placement, also with 100% restenosis rate but with the mean time of 12 months until restenosis, which was later than the group receiving only balloon angioplasty. In treating the patients with central vein stenosis, stent placement seems to be more advantageous over PTA in terms of restenosis rate and the mean duration of patency. In the case of instent lesion, inserting the stent for the second time after stenosis recurred lengthened the duration of patency compared to performing balloon angioplasty alone.

한국어 판 구조화 임상면담도구 개발 : 신뢰도 연구

한오수,안준호,송선희,조맹제,김장규,배재남,조성진,정범수,서동우,함봉진,이동우,박종익,홍진표 대한신경정신의학회 2000 신경정신의학 Vol.39 No.2

연구목적: 정신장애의 정확한 진단과 평가는 임상에서뿐만 아니라 신뢰성 있는 연구를 위해서도 매우 중요하다. Structured Clinical Interview for DSM-IV(SCID)는 임상전문가들이 사용하는 진단도구로서, 비교적 짧은 시간에 정확한 진단을 내릴 수 있다. 본 연구는 한국어판SCID를 개발하고 그 신뢰도를 평가하기 위해 수행되었다. 방법: 국문학자가 포함된 번역위원회를 통하여 연구용판 SCID를 번역한 후, 정신과 의사 2인과 임상심리학자 1인에게 한국어판SCID 실시방법을 교육시킨 뒤 한국어판SCID를 이용한 면담의 평가자간 신뢰도 (interrater reliability)를 검증하였다. 면담 대상은 1999년 2월에서 3월까지 2개 병원 정신과에 치료중인 환자 90명(남:41명, 여:29명)이었다. 결과: 현재 장애(current disorder) 평가에서 주요 우울장애, 기분부전장애, 정신분열병, 알코올 남용 및 의존, 기타 물질 남용 또는 의존, 여러 불안장애들 및 섭식장애 등과 같은 대부분 장애의 kappa값은 .70이상으로 매우 높았다. 그 이외의 양극성 장애, 망상장애, 광장공포증, 감별 불능 신체화 장애 및 건강염려증의 kappa값도 .69에서 .40사이로 수용할 수 있는 정도였다. 평생 장애(lifetime disorder)에서는 양극성 장애(k=.69)와 감별 불능 신체화장애(k=.59)를 제외한 다른 모든 장애의 kappa값이 .70이상이었다. K-SCID 면담시 Ⅰ축 질환에 대하여 흔하게 다중 진단이 내려졌으며, 평균 진단 수는 1.5∼1.7개로 나타났다. 결론: 한국어판 SCID는 신뢰도가 높은 진단도구로 생각되며, 향후 정신질환의 정확한 진단과 임상연구에 유용하게 사용될 수 있다. Objectives: Accurate diagnosis and assessment for psychiatric disorders is crucial for research, as well as for clinical practice. Structured Clinical Interview for DSM-Ⅳ(SCID-RV) is a less time-consumimg and more accurate structured diagnostic interview form. It can be used by clinical professions and is known for a reliable diagnostic tool. Present study was conducted to develop Korean version of SCID-RV and to test the inter-rater reliability. Methods: The authors have translated original SCID-RV into Korean, and revised in parallel with sociocultural background of Korea. Ninety patients from two psychiatric hospitals, both outpatient and inpatient, were interviewed and rated independently by three raters. Results: The kappa coefficients for most of illnesses, such as major depressive disorder, dysthymia, schizophrenia, alcohol abuse and dependency, anxiety disorder and eating disorder were excellent(>0.70) in the evaluation of current disorders. And the kappa coefficients for bipolar disorder, delusional disorder, agoraphobia, undifferentiated somatoform disorder, and hypochondriasis were acceptable(>0.40) in the evaluation of current disorders. In the evalua-tion of lifetime disorders, the concordant rates of all the diagnoses except bipolar disorder and undifferentiated somatoform disorder were excellent. Lack of hierarchy in DSM-Ⅳ allows for multiple Axis I diagnoses. Mean numbers of Axis I diagnoses per subject assigned by the three raters were 1.5-1.7. Conclusions: Our findings confirm that SCID-RV yields highly reliable diagnoses. SCID-RV is recommended for accurate diagnosis in clinical practice and research on psychiatric disorders.