용융침투성장법을 이용한 YBCO 단결정 제조

한상철,정년호,한영희,성태현,Han, Sang-Chul,Jeong, Neyon-Ho,Han, Young-Hee,Sung, Tae-Hyun 한국전기전자재료학회 2007 전기전자재료학회논문지 Vol.20 No.6

Large and single-grain Y-Ba-Cu-O(YBCO) bulk superconductors have been fabricated by using a seeded infiltration and growth method. $Y_2BaCuO_5$(Y211) precursor pellets and $YBa_2Cu_3O_x$(Y123) liquid source pellets were prepared using commercial powder and were processed by infiltration and growth method to achieve low pore and high trapped field property. The superconductor properties of the single crystal are measured and analyzed in relation with the density and size of the Y211 particle in the Y123 matrix. An optimum processing condition is suggested based on the analyzed results.

웨어러블 산업의 특성과 발전전략

한상철,한경수,Han, Sang-Cheol,Han, Gyeong-Su 한국정보디스플레이학회 2014 인포메이션 디스플레이 Vol.15 No.6

대면적 YBCO 고온 초전도 벌크 자석 및 조작기 개발

한상철,박병준,정세용,한영희,이종원,Han, Sang-Chul,Park, Byung-Jun,Jung, Se-Yong,Han, Young-Hee,Lee, Jong-Won 한국전기전자재료학회 2015 전기전자재료학회논문지 Vol.28 No.7

For the practical application of a YBCO superconductor bulk, the superconductor bulk magnet with high magnetic field on a large area surface should be fabricated. To make this, YBCO single crystal bulks with fine $Y_2BaCuO_5$(Y211) particles have been prepared by the top-seed melt growth(TSMG) method with $YBa_2Cu_3O_x$, $Y_2O_3$, and $CeO_2$ mixing precursor. By using $Y_2O_3$ instead of $Y_2BaCuO_5$ as precursor, the manufacturing process became simpler and more economical. The microstructures, trapped field and critical current density of the various conditioned YBCO bulks have been observed, analyzed and measured. The different characteristic values of the several samples have been analyzed from the viewpoint of their microstructures. We have developed a $8{\times}12cm$ size superconductor bulk magnet, up to 3 T class, by using the 4 T class-high field superconducting magnetizer and confirmed the applicability of the transmission level circuit breakers by measuring the strength and speed of the superconductor bulk magnet actuator.

고액용융성장법을 이용한 YBCO 단결정 제조

한상철,이정필,박병철,정년호,박병준,정세용,한영희,성태현,Han, Sang-Chul,Lee, Jeong-Phil,Park, Byeong-Cheol,Jeong, Neyon-Ho,Park, Byung-Jun,Jung, Se-Yong,Han, Young-Hee,Sung, Tae-Hyun 한국전기전자재료학회 2009 전기전자재료학회논문지 Vol.22 No.10

YBCO bulks with fine $Y_2BaCuO_5$(Y211) particles have been prepared by the top-seed modified powder melting process method, Solid-Liquid Melt Growth(SLMG), with $Y_2O_3$, $BaCuO_2$ and CuO mixing precursor. By using $Y_2O_3$ instead of $Y_2BaCuO_5$ as precursor, the processing became to be simpler and cheaper than the current powder melting process. The microstructures, trapped field and critical current density of the various conditioned YBCO bulks have been analyzed and the effect of Pt additive was studied. The different trapped magnetic field values of the several samples have been explained in the viewpoint of their microstructures. The fabrication of large-sized YBCO single domain has been conducted.

동결보존된 생쥐 고환조직 세포의 광학 및 전자현미경적 관찰

한상철,송상진,이선희,오승한,궁미경,박용석,Han, Sang-Chul,Song, Sang-Jin,Lee, Sun-Hee,Oh, Seung-Han,Koong, Mi-Kyung,Park, Yong-Seog 대한생식의학회 2003 Clinical and Experimental Reproductive Medicine Vol.30 No.2

Objective: The aim of this study was to investigate the morphological aspects of testicular tissue before and after freezing-thawing by light and transmission electron microscopy. Methods: Tissue biopsies were carried out on mouse testis for freezing. Samples in medium containing 20% glycerol were frozen by computer-controlled freezing program. The effect of freezing-thawing on the structural change of testicular tissues were examined by light and electron microscopy. Results: The freezing-thawing procedure had no significant effect on tubular diameter. However, it caused folding of the lamina propria, and notable damage to Sertoli cells, spermatogonia and spermatocytes. The cells were detached, desquamated from the basal lamina and had increased vacuolization. Round spermatids, elongated spermatids and spermatozoa were less affected, and most of them maintained their normal structure. Conclusions: The structure of spermatogonia, spermatocyte and basal compartments in seminiferous epithelium was significantly altered by freezing-thawing procedure of mouse testicular tissues. Thus, we need to develop a more reliable method for the cryopreservation of testicular tissues.

신생 생쥐 고환에서 기인한 다분화능 생식줄기세포주의 확립 및 특성 분석

한상철,송행석,전진현,Han, Sang-Chul,Song, Haeng-Seok,Jun, Jin-Hyun 대한생식의학회 2008 Clinical and Experimental Reproductive Medicine Vol.35 No.1

목 적: 본 연구에서는 신생 생쥐 고환으로부터 다분화능 생식줄기세포주 (MGSCs)를 확립하고, 배아체 형성을 통한 삼배엽성 세포로의 분화 가능성을 확인하고자 하였다. 연구방법: 고환에서 유래한 MGSCs를 확립하기 위하여 생후 $2{\sim}3$일된 생쥐 고환 조직으로부터 세포들을 분리하여 1% FBS를 첨가한 생쥐 배아줄기세포주 배양조건에서 배양하였다. MGSCs 콜로니가 형성된 후에는 배양액의 FBS의 농도를 15%로 높였다. 이러한 과정으로 확립된 MGSCs의 미분화 및 분화 특성을 배아줄기세포주와 비교, 분석하였다. 결 과: 신생 생쥐 고환 조직에서 수획한 세포들로 실시한 9번의 배양실험에서 2개의 MGSCs 세포주를 확립하였다. MGSCs 세포주와 생쥐 배아줄기세포 모두에서 미분화 표지인자인 Thy-1, Oct-4, Nanog, Sox2의 발현과 alkaline phosphatase 활성을 관찰할 수 있었으며, MGSCs의 미세구조 또한 생쥐 배아줄기세포와 유사하였다. MGSCs에서 형성된 배아체에서 삼배엽성 표지유전자의 발현을 확인하였다. 결 론: 본 연구의 결과는 배아줄기세포의 윤리적인 문제점을 극복할 수 있는 고환 유래의 다분화능 MGSCs가 생물공학과 재생의학에서 효율적으로 이용될 수 있는 가능성을 보여준 것으로 생각된다. Objective: The aim of this study was to investigate whether multipotent germline stem cells (MGSCs) can be established from neonatal mouse testis. Methods: Various cells containing MGSCs were collected from neonatal testis of ICR mice and allocated to plates for in vitro culture. After 7 days in culture, the cells were passed to a fresh culture plate and continuously cultured. From the third or fourth passage, the presumed MGSCs were cultured and maintained on mitomycin C-inactivated STO feeder cells. The MGSCs were cultured in a condition where mouse embryonic stem cells (ESCs) are cultured. Characteristics of the MGSCs were evaluated by RT-PCR, immunocytochemistry, alkaline phosphatase activity, karyotyping, and transmission electron microscopy. Results: Two MGSCs lines were established from 9 pooled sets of neonatal testicular cells. MGSCs colonies were morphologically undistinguishable from ESCs colonies and both MGSC lines as well as ESCs expressed undifferentiated stem cell markers, such as Thy-1, Oct-4, Nanog, Sox2 and alkaline phosphatase. Fine structure of undifferentiated MGSCs were similar to those of ESCs and 60% of MGSCs (12/20) had normal karyotype at passage 10. They were able to form embryoid bodies (EBs) and MGSC-derived EBs expressed marker genes of three germ layers. Conclusion: We could establish the MGSCs from neonatal mouse testis and they were differentiated to multipotent lineages of three germ layers. Molecular characteristics of MGSCs were similar to those of ESCs. Our results suggest a possibility that multipotent stem cells derived from testis, the MGSCs, could replace the ESCs in biotechnology and regenerative medicine.

폐쇄성 무정자증 환자와 정자형성저하증 환자의 고환정자를 이용한 체외수정 및 배아이식술의 결과

한상철,박용석,최수진,이선희,홍승범,이형송,임천규,송인옥,서주태,Han, Sang-Chul,Park, Yong-Seog,Choi, Su-Jin,Lee, Sun-Hee,Hong, Seung-Bum,Lee, Hyoung-Song,Lim, Chun-Kyu,Song, In-Ok,Seo, Ju-Tae 대한생식의학회 2009 Clinical and Experimental Reproductive Medicine Vol.36 No.1

목 적: 폐쇄성 무정자증 (obstructive azoospermia) 환자와 정자형성저하증 (hypospermatogenesis) 환자의 고환 정자를 이용한 체외수정 및 배아이식술의 결과를 비교, 분석하고자 하였다. 연구방법: 2003년 1월부터 2006년 12월까지 체외수정 및 배아이식술을 위해 고환조직 정자채취술을 시행한 폐쇄성 무정자증 환자 155명 (241주기)과 정자형성저하증 환자 28명 (34주기)을 대상으로 하였다. 고환조직 정자채취술과 세포질내 정자주입술을 실시한 후 수정률, 착상률, 임신율, 출산율을 비교하였으며, 통계적 분석은 t-test와 ${\chi}^2$-test를 사용하였다. 결 과: 정자형성저하증 환자의 고환정자 회수 결과, 신선고환을 사용한 21주기 중 1주기에서는 정자를 회수하지 못하였으나, 정자를 확인하고 고환조직 동결보존 후 융해한 13주기에서 모두 정자를 회수할 수 있었다. 수정률은 정자형성저하증 환자보다 폐쇄성 무정자증 환자에서 통계적으로 유의하게 높았다 (75.6 % vs. 62.6%, p<0.001). 난할 배아 발생률도 정자형성저하증 환자보다 폐쇄성 무정자증 환자에서 통계적으로 유의하게 높았다 (66.8% vs. 54.8% p<0.001). 그러나 우수배아 형성률, 임상적 임신율, 착상률, 출산율에는 차이가 없었다. 결 론: 정자형성저하증 환자의 고환정자를 사용하여 세포질내 정자주입술을 실시할 경우 수정률과 초기 난할율은 폐쇄성 무정자증 환자보다 낮지만, 정상적으로 발달한 배아를 이식할 경우 임신율, 착상률, 그리고 출산율에는 영향을 미치지 않는 것으로 사료된다. Objective: To compare the clinical outcomes of ICSI with sperm retrieved from testicular tissue in patients with obstructive azoospermia (OA) or hypospermatogenesis (HS). Methods: From January 2003 through December 2006, 155 patients with OA (241 cycles) and 28 patients with HS (34 cycles) were included in this study. We compared clinical outcomes of ICSI with testicular sperm such as fertilization rate, implantation rate, clinical pregnancy rate and delivery rate. Data were statistically analyzed using t-test and ${\chi}^2$-test. Results: Testicular spermatozoa could not be retrieved in 1 out of the 21 cycles where fresh testicular sperm extraction in HS patients. Fertilization rate (FR) was significantly higher in OA than HS (75.6 % vs. 62.6%, p<0.001). Cleavage rate (CR) per fertilized zygote was also significantly higher in OA than that in HS (66.8% vs. 54.8% p<0.001). However, there were no significant differences in good embryo rate (GER), clinical pregnancy rate (CPR), implantation rate (IR) and delivery rate (DR). Conclusion: Our results show that testicular sperm of HS does not affect CPR, IR, and DR although it has shown reduced FR and CR.

공간분활 및 영역열량측정에 의한 공평 자동난방운영시스템 구현

한상철,류광렬,Han, Sang Cheol,Ryu, Kwang Ryol 한국정보통신학회 2019 한국정보통신학회논문지 Vol.23 No.8

본 논문은 주거공간영역 별로 사용 난방열량을 측정하고 사용량을 자동으로 측정 분석하여 계량 운영 할 수 있는 공평관리 자동난방운영시스템의 구현이다. 난방공간은 4영역으로 분할하여 하나의 계량기로 유량과 열량이 계측된다. 이 시스템은 열량검출, 온도조절기, 밸브제어기, PC컨버터와 모니터링으로 구성된다. 난방 공간영역은 실내온도에 따라 열량 계산에 필요한 환수 온도가 측정되고 영역별 열량이 산출된다. 실험결과, 측정기기로 계측한 값과 비교하여 측정열량 값의 오차 범위는 1% 내이다. 기존의 유량계를 이용한 난방 분할 방식과 비교하면 난방 에너지 사용 비용이 약 7% 저감된다. 이 공평시스템은 향후에는 BEMS와 공동으로 연계하는 연구가 필요하다. This paper describes the system implementation of the heating operation based on spatial distributing and zonal calorie measuring and analyzing of houses to calculate the fair amount of the heating meterage automatically. The heating space is distributed into 4 zones, which the flow rate and calories are checked by one meter respectively. The system is composed of a heating sources, adjuster of thermostat, valve controller, PC converter and total monitering. The returning temperature in the spatial zones is measured for the heating calorie to calculate the zonal calories according to the rooms temperature. The proposed system results in error by 1% or less in comparing with the dedicated experimental equipment, and reduces energy cost by 7% from conventional system. The fair checking system will be enhanced with building energy management system in the future.

A Study on the Comparisom of Load-carrying Capacity by the rating Methods of Bridges

한상철,양승이,Han, Sang Chul,Yang, Seung Ie Korean Society of Steel Construction 2001 韓國鋼構造學會 論文集 Vol.13 No.5

현재교량의 절반 가량이 성능이 저하되어 보수 보강이 요구되고 있는 실정인데 이들 교량은 제 기능을 발휘하지 못하거나 소요강도에 미달되는 경우가 있다. 필요이상의 보수보강비용 또는 재거설의 비용의 투입을 피하기 위하여 현재 상태의 내하력이 정확히 평가되어져야 한다. 교량의 평가방법으로 허용응력 평가법 (ASD) 하중계수평가법 (LFD) 하중저항계수평가법 (LRFD) 등이 현재 사용되고 있다. 본 논문에서는 허용응력 평가법 (ASD) 하중계수평가법 (LFD) 하중저항계수평가법 (LRFD)등이 비교되고 실제 교량에 적용된 하중실험의 자료들을 모았다. 그리고 하중실험의 교량평가 결과와 이론에 의한 교량평가 결과의 차이점에 대해 연구하였다. 그리고 기존에 존재하는 교량에 ASD, LFD 그리고 LRFD 방법을 적용 비교하여 어느 수준에 해당되는지를 비교 검토하였다. About half of bridges in United States are considered to be deficient and therefore are in need of repair or replacement. Half of these are functionally obsolete, and others do not have required strength For these bridges repairs and replacements are needed To avoid the high cost of rehabilitation the bridge rating must corectly report the present load-carrying capacity Rating engineers use Allowable Stress Design(ASD) Load Factor Design(LFD), and Load Resistance Factor Design(LRFD) to evaluate the bridge load carrying capacity In this paper the load rating methods are introduced and bridge load test data are collected. The reasons that make the difference between test results and analytical results are explained for each bridge load test And load rating methods are applied to real bridge. The rating factors from each method are compared.

ALFD방법에 의한 연속합성판형교의 강도평가에 대한 연구

한상철,정경희,Han, Sang Cheol,Chung, Kyung Hee 한국강구조학회 1999 韓國鋼構造學會 論文集 Vol.11 No.2

ALFD방법은 연속합성판형교의 과재하중과 최대하중에 대한 강도검토에 있어서 실제적인 거동을 나타낼 수 있는 탄소성해석법이다. 주어진 하중으로 인한 최대 정, 부모멘트단면에서의 항복은 활하중이 통과한 후에 잔류하는 소성회전을 일으킨다. 또한 제조시의 잔류응력으로 인하여 이론적인 항복모멘트 이하에서도 소성변형을 일으킨다. 이러한 국부항복은 다음에 작용되는 과재하중하에서 탄성화되어 정의 자생모멘트를 유발한다. 본 연구에서는 지점과 최대 정모멘트 단면에서의 단위소성회전각으로 인한 자생모멘트를 공액보법과 3연모멘트법에 의하여 구하였고, 9개의 설계경간을 지점단면을 감소시켜가면서 본 연구에서 개발한 전산프로그램에 의하여 연속관계와 모멘트-비탄성회전각 실험곡선과 일치하는 자생모멘트를 구하였다. 또한 한국도로교시방서에 준하여 비조밀단면을 갖는 3경간 연속합성판형교의 평가를 수행하였다. Elastic-plastic methods have been used for the better prediction of the actual behavior of continuous-composite plate girder bridges in the overload and maximum load analysis. The structural evaluation using ALFD(Alternate Load Factor Design) uses the elastic-plastic analysis. The plastic rotations that remain after the load is removed can be occurred by the yielding locations of the maximum moment section. This situation can occur due to the residual stresses even if the moment is below the theoretical yield moment. The local yielding causes positive automoments that assure elastic behavior under subsequent overloads. In this study, the automoments at the piers occurred due to the unit plastic rotations and other locations were calculated by the conjugate-beam method and three-moment equation, using the nine design span with progressively smaller pier sections. The automoments were determined by the developed computer programs in this study in which the moments and plastic rotations from the continuity and moment-inelastic rotation relationships must be equal. And also the ratings of 3-span continuous composite plate girder bridges with non-compact section were carried out according to the Korean Highway Bridge Specification.