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.

노인에서 내피의존성 혈관반응에 대한 비타민 C의 효과에 대한 연구

온영근,김용석,오도연,최진호,황의석,김철호 대한노인병학회 2001 Annals of geriatric medicine and research Vol.5 No.1

Brassica 種들의 花뢰크기에 의한 小胞子 發育段階 및 胚發生 比較

장영석(Young Seok Jang),민경수(Kyung Soo Min),오용비(Yong Bee Oh),정동희(Dong Hee Chung) 한국육종학회 1997 한국육종학회지 Vol.29 No.4

The purpose of this study is to search for the identifing method that could separate buds with embryogenic potential from collected buds for increasing the efficiency of embryogenesis by microspore culture in Brassica species. It was investigated developmental stage of microspore by bud-size and ratio of petal/anther length and compared to amount of embryogenesis through isolated microspore culture from the buds with late-uninucleate stage. In Brasica napus, Lisandra of spring type showed bud-size of 3.2~4.1mm which belongs to late-uninucleate stage as embryogenic microspores and their range of petal/ anther length ratio were 1/2~3/4. Hallayuchae of winter type rapeseed showed bud-size of 3.1~3.6mm which belongs to late-uninucleate stage as embryogenic microspores and their range of petal/anther length ratio were 1/3~1/2. Two genotypes of B juncea had the same petal/anther length ratio as range of 1/2~3/4 with embryogenic microspores but their bud-size were some difference as bud-size of Young-sanpohwanggyeja were 2.9~4.0mm and bud-size of Hwanggyeja were 2.9~4.1mm. Also, two genotypes of B. campestris had the same petal/anther length ratio as range of 2/3~3/4 with embryogenic microspores but bud-sizes were some difference as bud-size of Hyakusai were 2.9~3.4mm and bud-size of Sosongchae were 2.9~3.2mm. In B. oleracea, the petal/anther length ratio with embryogenic microspores according to bud-size were showed range of 1/2~2/3 in all of two genotypes and bud-size of Broccoli were 2.4~3.2mm and bud-size of Cauliflower were 2.9~3.7mm. In the embryo yield per 100,000 microspores by isolated microspore culture from the buds with embryogenic microspores, Young-sanpohwanggyeja of B. juncea were 47 embryos and Hwanggyeja of B. juncea were 23 embryos, B. campestris of Hyakusai were 367 and Sosongchae were 123, B. oleracea of Broccoli were 678 and Cauliflower were 562. However in B. napus was showed much differences by the growth habit, the spring type of Lisandra were producted 7,047 embryos of which higher about 9.2 times than those of winter type Hallayuchae.

흰쥐 시상에서 Epidermal growth factor receptor면역반응 신경세포의 생후 발달에 관한 연구

박영란,정윤영,김종중,문정석,오재욱,정영욱,김주수 조선대학교 2003 The Medical Journal of Chosun University Vol.28 No.1

Background and Objectives : Epidermal growth factor receptor (EGFR), a 170-kDa transmembrane glycoprotein, appears to mediate epidermal growth factor (EGF) activity. Transforming growth factor-α and EGF produce their biological effects in numerous systems by stimulating the EGFR In this study, we examine the postnatal development of EGFR immunoreactivity in the different regions of the thalamus of the rat Materials and Methods : The present study is based on 28 postnatal cases of rat thalamus ranging from the day of birth, postnatal day 0 (P0) to 30 days (P3, P5, P10, P15, P20, P30), and these cases were compared with adult rat thalamus. Cryostat sections were processed free-floating with monoclonal antibody by immunohistochemistry Results : EGFR immunoreactivity in the thalamus of the rat showed very different patterns according to postnatal ages and thalamic areas. EGFR-immunoreactive cells appeared in the first two postnatal weeks, except the ventral posterior thalamic nuclei. In the early postnatal days, EGFR-immunoreactive cells appeared thalamic midline structures, increased progressively in the first two postnatal weeks, and followed mediolateral gradient. The mature patterns of EGFR-immunoreactive cells were achieved at P20 Conclusion : These data indicate that the maturation of EGFR-immunoreactive cells requires a relatively prolonged period of time to achieve an adult configuration. Many growth factors probably play protective or neurotrophic roles at EGFR-immunoreactive neurons of thalamus both young and adult rats In addition to difference in time of appearance in thalamic nuclei and developing pattern with mediolateral gradient suggest that EGFR-immunoreactivities are correlated with the appearance of the related functional.

간세포암과 감별이 어려웠던 악성중피종 치험 1예

김선문,허원석,채경훈,강윤세,정재훈,김연수,박기오,문희석,이엄석,김석현,성재규,이병석,이헌영,신경숙,조준식,송인상,강대영 충남대학교 의학연구소 2003 충남의대잡지 Vol.30 No.2

Malignant peritoneal mesothelioma is a rare neoplasm that arises from the mesothelium of a serosal cavity and is a rapidly fatal disease with a median survival of 4 to 12 months for untreated cases. Recently, we experienced a case with malignant peritoneal mesothelioma who was suspected hepatocelluar carcioma by abdominal CT scan and was confirmed by biopsy including immunohistochemical stain(calretinin) after surgery. We performed tumor excisions and wedge resection of the liver(segment Ⅷ)and inserted Tencoff catheter in abdominal cavity at 25th day of post-operation. We treated with intraperitoneal paclitaxel(25mg/m^(2)/day for 5 days) six courses monthly. She was well tolerable and is still living without any evidence of recurrence for 14th month of post-operation.

대한민국 환경교육의 체계와 활성화 방안

오영석 동국대학교 지역개발대학원 1999 開發論叢 Vol.8 No.-

섬유 보강 모래의 전단 강도 특성

吳英錫,朴鎔遠 명지대학교 공학기술연구소 1992 공학기술연구소 논문집 Vol.7 No.-

In this study, we have studied the shear strength and stress-strain characteristics of fiber reinforced sand through laboratory direct shear test. Among many factors affecting the reinforcing effect the stiffness, the interval and orientation of the nclusions are lighted in this study. In the tests, KS standard sand and poly-vinyl wire coating are used and the number of reinforcement and inclination angle to the expected shear plane are changed. From the test results, it is found that fiber reinforced sand has greater shear resistance and extensibility(ductility) as well and smaller loss of post peak strength compared to unreinforced sand. It is also observed that the initial orientation of the reinforcement affects the magnitude of the shear resistance increase in the composite. In this test, reinforcements oriented at 45˚ to shear plane produced the maximum increase in shear resistance. Further research and observations on full scale structures are required in order to develop a better understanding of the potential effect of reinforcement bending stiffness and on the behavior of fiber reinforced sand.

면접조사를 통한 초등학생의 영양교육 실태 및 실천도 조사

오유진,이영미,김정현,안홍석,김정원,박혜련,서정숙,김경원,권오란,박혜경,이은주,성현이 대한지역사회영양학회 2008 대한지역사회영양학회지 Vol.13 No.4

This study investigated the experience and practice of elementary school students on nutrition education. The data were collected from 217 male and female students attending 5-6th grade elementary schools in Seoul and Kyunggi-Do from March to June 2007, interviewing face to face by a nutrition teacher and 3 interns of a nutrition teacher. The results were as follows: 86.5% of the subjects learned about ‘Table etiquette’, ‘Reasons for eating fruits and vegetables’ (78.7%), ‘Food waste and environment’ (72.3%), ‘Healthy snacks’ (55.7%), ‘Food sanitation’ (52.3%), ‘Food culture of foreign countries’ (48.1%). Nutrition education experience was significantly different by gender. A total of 43.5% boys responded that they never learned about ‘basic food preperation’ (p < 0.01). They had learned ‘Nutrients for body’ and ‘Food waste and environment’ in school, ‘Healthy weight loss’, ‘Food culture of foreign countries’, ‘Food circulation’ on television, Most content (‘Table etiquette’, ‘Simple cooking’, ‘Food sanitati n’, ‘Eating behaviors for health’, ‘Reasons for eating fruits and vegetables’, ‘Healthy snacks’) was learned from parents. The practice after nutrition education was higher in ‘Table etiquette’ (2.14), ‘Eating fruits and vegetables’ (2.07) than others compared with education experience. The most reason of non-practice on nutrition information was ‘Troublesome’. In ‘Nutrients for body’, a boy answered ‘Difficult for practice’ 20.0%, a girl answered ‘Difficult to understand’ 32.6%, showing a significant difference between the gender groups (p < 0.001). They remembered the ‘Nutrients for body’ (49.6%), ‘Food sanitation’ (44.5%) because of ‘important content’,‘Basic food preparation’ (40.6%), ‘Food culture of foreign countries’ (36.3%) because of ‘interesting content’, ‘Healthy weight loss’ (52.0%), ‘Eating behavior for health’ (44.5%) and ‘Healthy snacks’ (33.7%) because of ‘need for my health’.

육상 창던지기 경기 중 최고기록 발현시기에 대한 연구

오봉석,조영제 한국스포츠리서치 2003 한국 스포츠 리서치 Vol.20 No.1

The purpose of this study was to find the best times that means the best record exhibition times during the javelin throwing competition of track and field. And anther purpose was to offer some valuable and practical informations about javelin throw to javelin throwers and their directors. The subjects of this study were 69(man 34, woman 35) javelin throwing athletes who passed elimination at national track and field events. These subjects thrown javelin 6 times, that is, 3 times during elimination times and 3 times during final times. So total throwing numbers were 552 times. And these javelin throwing records were recognized by Korea Amateur Athletic Federation as official records. The results were as follows; First, in man's javelin athletes the order of elimination record was first times> second times> third times. The order of final record was third times> first times> second times. And on the whole, the order of record was sixth times> fourth times, first times, fifth times> second times> third times. So man's javelin throw records were divided into three types and it's difference was significant(p<.05). Second, in woman's javelin athletes the order of elimination record was third times> second times> first times. The order of final record was third times, second times> first times. And on the whole, the order of record was sixth times, fifth times> third times> fourth time s> second times> first times. So woman's javelin records were divided into five types, but it's difference was not significant(p>.05). Third, the all time's relation of javelin throwing records was significant(p<.01). These results lend support for the notion that javelin throwing athletes have higher final records than elimination records. By the way, I think this kind of competition record distribution has some problems in the point of the javelin throwing trait. That is, the only one time's record that means the best competition record was accepted by KAAF as an official record. So, I think it is necessary for javelin athletes to improve their elimination record. In other words, during the elimination period javelin athletes are likely to be placed in situation that improve their competition record. This necessity was supported by the warming-up theory and by the trait of javelin throwing competition.

地方政府의 環境行政機能 强化方案

오영석 동국대학교 경주대학 1995 東國論集 Vol.14 No.-

The full-scale autonomy of local governments in Korea in 1995 is considered as a chance to raise the capability of environmental administration of local governments for several reasons. This article aims to discuss four menas to increase the capability. The current system of environmental administration in Korea is described in terms of organizations and functions. The Korean system is highly centralized. The Korean Environmental Protection Agency and other related ministries possess almost all powers in planning and enforcement. It is recommended to turn over the centralized powers to local governments. Some criteria are suggested for the distribution between central and local governments. It includes efficiency, spill-over effect, technology, and level of hazard. The four means to raise the administrative ability of local governments are (1) to hire more public servants who have skills and knowledge in environmental managements, (2) to expand expenditures for environmental protection, (3) to adjust current environmental administration functions between central and local governments, and (4) to transfer some public functions to individuals and firms in private sectors.