Superconducting MgB2 Wire Drawing Considering Anisotropic Hardening Behavior and Hydrostatic Effect

Young‑Seok Oh,Ho Won Lee,Kook‑Chae Chung,Duck‑Young Hwang,Seong‑Hoon Kang,Jeong Whan Yoon 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.7

Numerical modeling was conducted to investigate the deformation behavior of powder mixture during multi-pass drawingprocesses for multi-filamentary MgB2wire. A modified Drucker-Prager Cap (DPC) model with an elliptical cap surface usingthe new material characterization method was developed to capture the anisotropic hardening behavior and hydrostatic effectof the powder mixture. A number of uniaxial die compaction, cold isostatic pressing, diametrical compression, and uniaxialcompression tests were conducted using different powder densities to characterize the modified DPC model. A commercialfinite element software ABAQUS with a user subroutine was used to simulate the drawing of the MgB2wire. The densityand area fraction of the powder mixture during the wire-drawing process were verified with experimental results. The differencein packing density at the inner and outer filaments of the MgB2wire was successfully captured by simulation. Inaddition, the effect of the initial packing density on the superconducting properties of MgB2wire was numerically studied. It is shown that the increase in the superconducting area, which results from a high initial packing density, should be moreeffective compared to the increase in the grain connectivity in enhancing the critical current properties for the MgB2wirewhen the final packing density is saturated after a number of drawing processes.

一部 鍍金作業者의 淋巴球 姉妹染色分體交換 出現에 關한 硏究

崔榮珠,金永煥,車喆煥 고려대학교 의과대학 1987 고려대 의대 잡지 Vol.24 No.1

Since the sister chromatid exchange(SCE) technique was developed by Taylor in 1958, it has been modified and utilized in the fields of mutagenicity, teratogenicity and carcinogenicity evaluation not only for academic purpose but also occupational medicine. In Korea, however, very rare approaches to mutagenicity of toxic agents were performed. And no research on SCE in human lymphocytes was reported in relation to occupational working environment up to date in Korea. Therefore this study was designed to know the possibility of utilizing the SCE as an index which could evaluate the effect of toxic chemicals on the health of industrial workers. A total of 32 metal plating workers using chromium which was proved having mutagenicity and carcinogenicity were selected as an experimental group for this studies. The SCE in peripheral lymphocytes of the workers was studied including the amount of chromium excretion in urine, the smoking amount and working years. The results were as follows; 1. The average number of SCE per lymphocyte was significantly higher in plating workers than nonexposure group showing the rate of 1.6 (5.7 v/s 3.6). 2. The difference in SCE status by smoking habit was not statistically significant both in exposure and unexposure groups. There was no difference in SCE status by career of exposed workers. 3. The higher the concentration of chromium in working environment, the higher the number of SCE per lymphocyte in exposed workers was showed, which revealed a clear dose-response relationship. 4. The correlation between number of SCE per cell and amount of chromium in urine was statistically significant with the coefficient of 0.661 showing Y= 0.23X + 3.0 (P<0.01), in which Y indicates number of SCE per cell and X indicates chromium concentration in urine by ㎍/1.

관상동맥 시술 도중 발생한 좌주간부 관상동맥 박리에 대한 스텐트 삽입 치료의 단장기 임상 결과 : acute and long-term results

이세환,이승환,홍명기,김영학,이철환,한기훈,송종민,강덕현,송재관,김재중,박성욱,박승정 대한내과학회 2004 대한내과학회지 Vol.66 No.6

목적 : 심도자 사용 시술과 관련된 좌주간부 관상동맥박리에 대한 적절한 치료는 아직 확실히 정립되지 않은 상태이다. 이에 본 연구는 좌주간부 관상동맥 박리에 대한 스텐트 삽입술의 단장기 임상결과를 후향적으로 분석하였다. 방법 : 좌주간부 관상동맥 박리에 대한 치료로 즉각적인 스텐트 삽입술을 시행하는 것이 안전하고 효과적인 방법임을 가설하였고, 이러한 즉각적인 스텐트 삽입을 시행한 10명의 환자를 대상으로 단장기적 임상경과를 의무기록 고찰과 전화 면담을 통해서 평가하였다. 결과 : 전체 환자 모두 처음부터 좌주간부 관상동맥에 유의한 협착을 가진 환자는 없었으며, 8명의 환자는 심도자의 조작으로 인한 박리가 발생한 경우였고(진단적 혈관 조영술 중에 3명, 유도 도자 조작 중에 5명), 나머지 2명은 다른 병변에 스텐트 삽입시술을 하는 중에 박리가 발생하였다. 이 10명의 환자에서 모두 즉각적인 스텐트 삽입술이 시행되었고, 4명의 환자에서 시술 도중 혈압 저하로 Intra-aortic Ballon Pump (IABP)를 장착하였다. 모든 환자에서 성공적으로 스텐트가 삽입되었고, 병원내 사망은 1명도 없었다. 6개월 추적 관상동맥 조영술은 8명의 환자에서 시행되었다. 혈관 조영상의 재협착(직경 협착 50% 이상)은 8명 모두에게서 관찰되지 않았으며, 퇴원 후 평균 31±25개월의 추적관찰 결과 주요 심장사건은 1건도 발생하지 않았다. 결론 : 비록 대상 환자가 적은 연구였지만 좌주간부 관상동맥 박리에 대한 스텐트 삽입술은 기술적으로 안전하고 빠르게 시행 할 수 있으며, 훌륭한 단장기적인 치료 효과를 보여준다. Background : The optimal treatment of patients with left main coronary artery (LMCA) dissection during catheter-based procedure remains uncertain. We retrospectively analyzed the acute and long-term results of bail-out stenting for LMCA dissection. Methods : In cases with significant LMCA dissection occurring during catheter-based procedure, prompt stent implantation may be safe and associated with favorable clinical outcome. We evaluated the acute and long-term results of bail-out stenting for LMCA dissection occurring during catheter-bases procedure in 1- patients. Results : Initially, there was significant stenosis of LMCA segment in these patients. Catheter-induced dissection occurred in 8 patients (during diagnostic angiography in 3 patients and guiding catheter manipulation in 5 patients). Two patients suffered dissection in the setting of stent deployment in other vessels. Therefore, bail-out stenting LMCA dissection was performed in a total of 10 patients. In 4 patients, hypotension developed and intra-aortic balloon pump was placed during procedure. Stents were successfully deployed in all patients. There was no in-hospital mortality. Six-month angiographic follow-up was performed in 8 patients. Angiographic restenosis(diameter stenosis 50%) was not observed in all patients at follow-up study. During a mean follow-up of 31±25 months after hospital discharge, there was no major adverse cardiac event (death, myocardial infarction, and target lesion revascularization). Conclusion : Bail-out LMCA stenting is technically feasible, and showed good acute and long-term results in a small series of patients.

암처리 엽수와 기간이 들깨의 생육 및 개화에 미치는 영향

최영훈,최영환,이영근,김용균,손병구,강점순,김근기 밀양대학교 농업기술개발연구소 2000 農業技術開發硏究所報 Vol.4 No.1

The lower leaves shading in upper leaves is unknown to be reduced significantly due to the early differentiation of flower-bud by dark treatment of leaves when growing perilla for harvesting the leaves in the greenhouse during the winter. This study analyzed the effect of dark treatment of leaves on the growth and regulation of flowering, which are closely related with differentiation of flower and amount of leaves. One leaf and 3 leaves per plant were dark treated for 0, 5, 10 days. Plant hight was reduced in 3 leaves treatment, but there was no difference in 1 leaf treatment. Stem diameter was reduced in both 1 leaf and 3 leaves treatments, which was more significant in 3 leaves treatment. Leaf area was reduced when 1 leaf was treated for 10 days, but there was no difference when 1 leaf was treated for 5 days. When 3 leaves were treated, leaf area was no difference between treatments. However, leaf area which 3 leaves were treated was reduced more significantly than that 1 leaf was treated. Seed weight was remarkably decreased when 1 leaf was treated for 10 days, and it was decreased when 3 leaves were treated for more than 5 days.

고감도 Ames test(microsuspension assay)와 임파구 소핵시험법을 이용한 변이원성에 관한 조사 연구

안지영,김해준,윤인재,성영자,김영환,장영철 大韓産業醫學會 1996 대한직업환경의학회지 Vol.8 No.3

In order to evaluate the mutagenic effects of extractable indoor air pollutants (organic matters), we measured the mutagenic activities by sensitive microsuspension Ames test using new tester strains (YG 1024 and YG 1029). And additionally to evaluate the mutagenic effects on vital cell, we examined the frequencies of micronucleus appearing in lymphocytes from dye handling workers and controls. This study was conducted from Jan. to May, 1995. The extractable indoor air pollutants were collected by low volume air sampler in a general office room and 3 of dye handling factories. And the environment of general office room divided into 3 different groups according to the type of room heaters. To determine the frequencies of micronucleus appearing in lymphocytes, we sampled peripheral venous blood from 20 of dye handling workers and 20 of controls, and cultured, and then examined the lymphocytes. The results obtained were as follows: 1. The indirect mutagenic activities of extractable organic matters from suspended particulates collected in a general office room were higher than the direct one. 2. The strain YG 1024 was the most sensitive, and the increasing order of test strains that showed higher number of revertant were YG 1024, YG 1029, TA 100, TA 98. 3. In the general office room, the room using kerosene heater showed the highest mutagenecity, and the next was buthan gas heater, and non-heating room in order. 4. The mutagenic effects of suspended particulates in dye handling factories on the strain YG 1024 was 1.2 times higher than YG 1029. 5. The frequencies of micronucleus appearing in lymphocyte of the circulating blood of dye handling workers and the control were 5.65±2.97‰ and 4.65±0.97‰, respectively. And the difference was statistically significant.

기내배양시 GA₃처리에 의한 들깨의 생육 및 개화조절

최영환,최영훈,강점순,손병구,이영근,주우홍 밀양대학교 농업기술개발연구소 2000 農業技術開發硏究所報 Vol.4 No.1

This study was conducted to estimate growth of leaf and shoot and flowering as affected by GA3 treatment in vitro. Plant height was longer as the concentration of GA3 was higher up to 2.0mg/l. Stem diameter was thick up to the concentration of GA3 was 0.1mg/l , but become thinner as the concentration of GA3 was higher. Root weight and root length were well developed in GA3 concentration was 0.5∼2.0mg/l. Number of roots was more in GA3 concentration was 0.5 and 1.0mg/l . The first flowering occurred in 40 days after 0.5 mg/l GA3 treatment. As the concentration of GA3 was higher, flowering was delayed. Number of flowering was significantly increased in GA3 concentration was 0.1 and 0.5mg/l. However, it was gradually decreased after 60 days. Percentage of flowering per plant was highest in GA3 concentration was 0.5mg/l , but it was lower as the concentration of GA3 was increased.

농장 사육되는 타조에서 나타난 다리 기형의 증례 보고

최종윤,손화영,전무형,조성환,김혜성,류시윤,박배근,이영원,윤원기 충남대학교 수의과대학 동물의과학연구소 2001 動物醫科學硏究誌 Vol.9 No.-

Two farmed young ostrich chicks were applied to pathology laboratory at Chungnam National University. Grossly, one ostrich showed rotated tibiotarsus, the other showed rolled toes. Case 1 ostrich was hypertrophy of fibualis longus and tibial cranialis tendon and gastrocnemius tendon in crus, inflammation of flexor digitorum longus. In histopathological views, myocytes of fiburalis longus were showed hypertrophy and hyperplasia. It is not found any specific feature in X-ray of the case 2 ostrich. Limb deformities were detected frequently in farmed ostrich chicks in 2- to 3 weeks old. Limb deformities were an important cause of mortality in farmed ostrich chicks during the first 10weeks after hatch. Cause of limb deformities were considered a nutrition problem.

췌장암 환자에서 알코올 내장신경 신경파괴블럭 후 발생한 간염

이상은,최석환,김영환,임세훈,이정한,이근무,정순호,최영균,김영재,신치만 인제대학교 2008 仁濟醫學 Vol.29 No.-

Splanchnic neurolytic block(SNB) with alcohol improves the management of pancreatic cancer pain. Adverse effects of alcohol SNB which include regional pain, hypotension, diarrhea, and acute alcohol intoxication are common, but acute hepatitis caused by alcohol neurolytic block is rare. A 63-year-old patient with pancreatic head cancer and liver metastasis had complete pain relief after both retrocrural tansdiscal SNB with 100% alcohol 10 ml. But, 1 day later, liver function test showed a high elevation in the aspartate aminotransferase (AST, 2182 IU/L) and alanine aminotransferase (ALT, 1807 IU/L). The patient had slight jaundice, general weakness, chilling, nausea and vomiting after SNB. Both AST and ALT decreased to 46 and 119 IU/L within 10 days with only supportive therapy. But, 19 days later, the patient died due to pneumonia. Our case illustrates the importance of clinical surveillance especially in patient with hepatic disease after alcohol SNB.

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.

완전 방실차단을 동반한 급성 심근염

이유선,정진옥,박용규,박형서,노상필,정승현,김정희,이재환,최시완,성인환 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

급성 심근염환자에서 발행한 완전 방실차단을 영구 심장박동 조율기로 치료한 1예를 경험하였기에 문헌고찰과 함께 보고하는 바이다. Myocarditis, an inflammatory process involving the myocardal wall, may be caused by most infectious agents. Irrespective of its etiology, it presents commonly with evidence of heart failure, hypotension, and various electrocardiographic abnormalities. Patient with myocarditis may be asymptomatic or may have a rapidly progressive fatal disease. Medical management of patients with myocarditis includes specific therapy for underlying infection and control of the complication of myocarditis such as congestive heart failure and arrhythmia. Recently we had experienced myocarditis with complete atrioventricular block in 37-year-old man. Although he had shown complete recovery of heart failure, he had shown complete atrioventricular block, so we inserted permanent pacemaker. We report it with review of the literature.