Possible Origin of Double-Peak Behavior of the Pinning-Force Density in Thick MgB2 Films with Columnar Structures

강원남,정순길,성원경,N. H. Lee,RANOTMAHIPAL 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.2

We have investigated the flux pinning force in MgB2 thick films with columnar structures. Three types of thick lms with different grain sizes were prepared on c-cut Al2O3 substrates by using the hybrid physical-chemical vapor deposition method at 520, 540 and 560 ℃. For all of the samples, the pinning force densities showed an unusual double-peak behavior with two types of irreversible fields, H*, separating the peaks. This double-peak behavior of the pinning forces did not obey any flux pinning scaling laws, but could be well scaled by using separate pinning forces with the reduced irreversible fields bH H=Hirr and bL H=H*. These results suggest that these double-peak features are associated with two different pinning mechanisms, such as point defects in intragrains and planar defects between columnar grains. The latter pinning sources were observed to be stronger pinning centers compared to the former ones.

산소 결핍도 변화에 따른 YBa_2 Cu_3 O_7-y의 열기전력 변화

강원남,김용민,조경철,최무용 성균관대학교 기초과학연구소 1988 論文集 Vol.39 No.1

To clarify the superconducting mechanism of the high Tc oxide superconductors, we have studied the interactions among electrons and elementary excitations and the electronic energy band structure by measuring the thermoelectric power of YBa_2 Cu_3O_7-y with various oxygen deficiencies. We have found that the major charge carriers in YBa_2Cu_3O_7-y are holes, that the width of the electronic energy band is larger than the intial estimation, and that the interaction between electrons and phnonos in the material is not strong enough to explain the high Tc super conductivity, while we have seen an evidence that there exist strong interactions between electrons and magnetic excitations.

Growth of Epitaxial MgB2 Thick Films with Columnar Grains by Using Hybrid Physical-Chemical Vapor Deposition

강원남,성원경,J. Y. Huh,N. K. Yang,J. G. Park,정준기,김철진 한국물리학회 2008 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.53 No.2

Epitaxial MgB2 thick films were grown on c-cut Al2O3 substrates at 600 ℃ by using a hybrid physical-chemical vapor deposition (HPCVD) technique. In order to obtain a high magnesium vapor pressure around the substrates at low temperatures, we used a specially designed susceptor having a susceptor cap and achieved a very high growth rate of 0.17 μm/min at low temperatures. The X-ray diffraction patterns showed epitaxial growth of MgB2 thick films. Hexagonal-shaped columnar grains with an average diameter of 250 nm were observed by using cross-sectional and planar view of transmission electron microscopy (TEM) images. For the 1.7-μm-thick film, Tc was observed to be 40.5 K with a Jc of 1.5 × 106 A/cm2 at 30 K for a self field. As a plausible explanation for the high Jc, the vortex pinning mechanism caused by planar arrays of intercolumnar boundaries will be considered.

혼성물리화학기상 증착법으로 여러가지 불순물층 위에 제조한 MgB₂ 박막에 대한 연구

강원남,성원경,정순길,박세원 한국초전도학회 2008 Progress in superconductivity Vol.10 No.1

By using the hybrid physical-chemical vapor deposition (HPCVD) technique, we have fabricated MgB₂ thick films on Al₂O₃ substrates with various impurity layers of Ni, Ti, and SiC. We have found a significant enhancement of the critical current density (Jc) for MgB₂ films grown on impurity layered substrates, indicating that additional impurity layers were provided as possible pinning sites by chemical doping in MgB2 films. All samples doped by Ni, Ti, and SiC were observed to have high superconducting transition temperatures of 39 - 41 K. The Jc of MgB₂ films grown on SiC impurity layered substrates showed three times higher than that of undoped films at high magnetic fields above 1 T.

산소결핍도 변화에 따른 YBa₃Cu₃O7-y의 열기전력 변화

강원남 成均館大學校 基礎科學硏究所 1989 論文集 Vol.39 No.2

Enhanced critical current density of MgB2 thin films deposited at low temperatures by ZnO seed impurity

강원남,Duong Pham,Huynh Van Ngoc,정순길,강대준 한국물리학회 2018 Current Applied Physics Vol.18 No.6

We report a facile method to enhance the critical current density (Jc) of superconducting MgB2 thin films. MgB2 thin films were deposited on zinc acetate dehydrate (Zn(CH3COO)22H2O) spin-coated Al2O3 (000l) substrates by using a hybrid physical-chemical vapor deposition system at low temperatures. Synthesis of MgB2 at low temperatures can reduce the substitution of Zn into the Mg site, hence avoiding the reduction of superconducting critical temperature. MgB2 thin films grown on ZnO-buffered layers showed a significant enhancement of Jc in the magnetic field due to the creation of additional pinning sources, namely point defects and grain boundaries. Broad peaks were observed in the magnetic field dependence of the flux pinning force density, indicating competition of different pinning sources.

서울시 관내 노인복지관 이용 노인의 죽음준비교육에 대한 효과

강원남(Kang, Won Nam),유지영(Lyu, Jiyoung) 한림대학교 고령사회연구소 2019 한림고령사회연구 Vol.7 No.1

본 연구는 서울시 관내 노인복지관 이용자들을 대상으로 죽음준비교육 중 사전연명의료의향서 및 호스피스 완화의료를 중심으로 한 단회기 교육이 관련 지식, 죽음태도, 죽음불안 및 삶의 의미에 어떤 영향을 미치는지 살펴보는 것을 목적으로 진행되었다. 실험은 서울시 관내 노인복지관을 이용하는 60세 이상 노인들을 대상으로 진행되었으며, 자발적 참여 의사를 밝힌 노인들을 실험집단 30명과 통제집단 24명으로 나누어 사전 검사 실시 후 실험집단을 대상으로 주 1회, 회기당 90분, 총 3회기에 걸쳐 죽음준비교육을 실시하였으며 교육 후 사후 검사를 실시하였다. 그리고 교육 효과의 지속성을 확인하기 위하여 4주 후 다시 추후 검사를 실시하였다. 통제집단은 죽음준비교육이 이루어지지 않았고 실험집단과 동일하게 사후, 추후 검사만을 실시하였다. 연구 결과 죽음준비교육이 사전연명의료의향서 및 호스피스 완화의료에 대한 내용들을 중심으로 단기적으로 이루어질 경우 관련된 지식과 죽음태도, 죽음불안, 삶의 의미에는 유의미한 변화가 없었으며, 통제집단과 비교했을 때도 유의미한 변화는 없었다. 이와 같은 교육은 사전연명의료의향서 및 호스피스 완화의료에 대해 참여자들에게 적절한 정보를 제공하고, 죽음에 대한 태도에 일부 영향을 줄 수 있으나, 죽음불안과 삶의 의미에 영향을 주는데는 한계가 있음을 시사한다. 이상의 결과를 통해 사전연명의료의향서 및 호스피스 완화의료를 중심으로 한 단회기 교육이 노인의 관련 지식 및 죽음불안, 죽음태도, 삶의 의미에 미치는 영향을 알아볼 수 있었으며, 죽음준비교육 진행 시 고려해야 할 구성별, 내용별, 회기별 적절성과 향후 죽음준비교육이 나아가야 할 방향성에 대하여 확인하였다. This study was performed to examine the effect of short-term death education focused on Advanced Directives and Hospice Palliative Care on the related knowledge, Attitude about Death, Death Anxiety, and Meaning of Life of the elderly in the senior welfare centers in Seoul. The experiment was conducted among the elderly over 60 years of age in senior welfare centers in Seoul. The participants were divided into two groups, such as 30 subjects for the experimental group and 24 subjects for the control group. All participants had pre-tests before the education. Three sessions of 90-minute Death Education were conducted once a week and post-tests were conducted after the education. In order to confirm the continuity of the educational effect, the follow-up tests were performed after 4 weeks. The control group did not receive death education, but they had the same post-tests and follow-up tests. The study results showed that there was no significant change in the related knowledge, Attitude about Death, Death Anxiety, and Meaning of Life when Death Education focusing on Advanced Directives and Hospice Palliative Care was conducted in a short-term. The education can provide participants with relevant information about Advanced Directives and Hospice Palliative Care, and may have some impact on their attitudes toward death. However, the impacts on Death Anxiety and Meaning of Life may be limited. In this study, the effect of a short-term education centered on Advanced Directives and Hospice Palliative Care on the related knowledge, Death Anxiety, Attitude about Death, Meaning of Life of the elderly was examined. Based on the study results, the composition, content, and the number of sessions for the appropriate Death Education were suggested.

국소적으로 진행된 자궁경부암의 방사선치료와 복합 항암화학요법의 동시치료 결과

강원철(One Chul Kang),최은경(Eun Kyung Choi),정원규(Weon Kuu Chung),김종훈(Jong Hoon Kim),장혜숙(Hyesook Chang),김용만(Yong Man Kim),김영탁(Young Tak Kim),남주현(Joo Hyun Nam),목정은(Jung-Eun Mok),이무송(Moo-Song Lee) 대한방사선종양학회 1998 Radiation Oncology Journal Vol.16 No.3

목 적 : 국소적으로 진행된 자궁경부암환자에서 방사선 치료와 5-FU, CDDP 복합항암요법의 동시 치료에 의한 종양관해율, 치료부작용, 예후인자, 실패양상과 생존율을 분석하기 위하여 전향적 제 2상연구를 시행하였다. 대상 및 방법 : 울산대학교 서울중앙병원 방사선종양학과와 산부인과에서 1992년 5월부터 1997년 1월까지 FIGO병기 IIB, III, IVA의 국소적으로 진행된 자궁경부암으로 진단받고 치료한 환자 73명중 방사선치료와 동시에 2회의 FP 항암요법을 시행한 68명을 대상으로 분석을 시행하였다. FIGO병기에 의한 분포는 IIB 46명, IIIA 2명, IIIB 15명, IVA 5명이었고, 이들의 연령분포는 31세에서 77세까지로 중앙값 58세이었다. 방사선치료시 외부조사는 전골반부에 4,140-5,040 cGy를 시행후 192Ir 고선량 근접치료기로 주 3회씩 6-7회의 강내조사를 시행하며 동시에 B점추가조사를 시행하여 A점에 7,500-8,000 cGy, B점에 6,000-6,500 cGy가 되도록 조사하였다. FP (5-FU;1,000mg/m2/24 hours, 4 days+CDDP; 20mg/m2/3 hours, 3 days) 항암화학요법은 방사선치료 시작 제 1일과 제 29일에 각각 4일간 투여하도록 하였다. 치료효과는 치료종료시점과 치료후 1개월, 3개월에 시행한 부인과 검사와 MRI로 판정하였다. 결 과 : 전체 환자의 추적기간은 4개월에서 68개월 (중앙값 24개월)이었다. 생존율을 분석한 환자 64명의 5년생존율 및 무병생존율은 각각 52%와 64%였으며, FIGO병기 IIB인 환자의 5년생존율과 무병생존율은 각각 58%, 71%이었고, FIGO병기 III와 IVA인 환자는 각각 36%, 46%이었다. 재발양상은 전체 재발율이 27.9% (19/68)로, 국소재발이 5.9% (4/68), 원격전이가 10.3%(7/68), 국소재발과 원격전이가 같이 있는 경우가 11.8% (8/68)로 나타났다. 치료종료 한달 후 치료 효과를 판정할 수 있었던 64명중 78% (50/64)가 완전관해를 보였다. 예후인자는 단변량분석시 5년생존율에 FIGO병기, 치료반응율, 골반내와 대동맥주위 림프절 전이유무가 통계적으로 의미 있었고, 다변량분석시 치료반응율과 치료중 혈색소 농도가 통계적으로 의의있게 나타났다. 치료에 따른 독성은 10%내외로 치료후 대부분 자연 회복되었으나, 2차 항암약물투여중 폐부종이 발생한 1명과 치료종료후 8개월에 만성합병증인 장천공이 발생한 1명은 치료에 따른 부작용으로 사망하였다. 결 론 : 국소적으로 진행된 자궁경부암에 대한 방사선치료와 복합항암요법의 동시치료는 수용 가능한 독성을 보였고, 진행된 경우 생존율의 향상을 관찰할 수 있었다. 좀 더 장기적인 추적관찰 후 여러 예후인자들을 고려하여 초기 치료반응율을 높이는 치료방법의 선택이 필요하리라 생각되며, 동시 방사선-항암화학요법의 종양관해율과 생존율의 차이를 알아보기 위한 제 3상 무작위 연구가 필요한 것으로 생각된다. Purpose : Prospective, single arm, Phase I/II clinical trial was performed to assess the efficacy and toxicity of the concurrent chemotherapy and definitive radiotherapy (RT) in patients with previously untreated locally advanced carcinoma of the uterine cervix. Methods and Materials : From May 1992 to January 1997, a total of 73 patients with advanced cervical carcinoma were entered on the protocol but 5 patients were excluded in analysis because of patients' refusal of treatment. Their ages ranged from 31 to 77 years, median 58 years. The International Federation of Gynecology and Obstetrics (FIGO) stage distribution was as follows: IIB 46, IIIA 2, IIIB 15 and IVA 5. RT consisted of external beam irradiation to 4,140-5,040 cGy/23-28 fractions plus high dose rate intracavitary treatments to deliver a dose of 30-35 Gy to point A in 6-7 fractions. During the intracavitary treatments parametrial boost was delivered for point B dose of 60 Gy in stage IIB and 65 Gy in stage IIIB. Two cycles of concurrent 5-fluorouracil and cisplatin (FP) chemotherapy (5-fluorouracil 1,000 mg/m2/day continuous infusion for 4 days, day 1-4, 29-32 and cisplatin 20 mg/m2/day intravenous bolus for 3 days, day 1-3, 29-31) administered starting on day 1 of RT. Results : The median follow -up was 24 months (range 4-68+). Sixty-four patients were evaluable for survival rate in this protocol; The 5-year actuarial and disease-free survival rate were 52% and 64%, respectively. The 5-year actuarial survival for stage IIB and III+IVA patients were 58% and 36%, respectively. The 5-year disease-free survival rate for stage IIB and III+IVA patients were 71% and 46%, respectively. Of the 68 patients evaluated for patterns of failure, overall recurrence rate was 27.9% (19/68): local failure in 5.9% (4/68), distant metastasis in 10.3% (7/68) and both in 11.8% (8/68). Of the 64 patients evaluated for response at one month after the completion of treatment, the complete response rate was 78% (50/64). Concurrent chemoradiation appear to be a well-tolerated regimen but there were two treatment-related deaths. Conclusion : Concurrent chemotherapy of FP with high-dose definitive RT in locally advanced carcinoma of the uterine cervix is feasible and effective with acceptable toxicities. This chemoradiation regimen may offer a modest survival benefit for advanced stage. Further follow -up of these patients will evaluate the impact of this regimen on the long-term local control and their survival.

하차 결측 교통카드 DB를 이용한 대중교통 OD 구축

신강원,강인구,남문우 한국ITS학회 2016 한국ITS학회 학술대회 Vol.2016 No.10

한국인 지원자에서 니모디핀의 생체이용율연구

강원호,심희옥,남진경,김동출 忠南大學校 生命科學硏究院 醫藥品開發硏究所 2006 藥學論文集 Vol.21 No.-

A reversed phase HPLC method was developed and validated for the determination of nimodipine in human plasma. Nitrendipine was used as an internal standard. Calibration curves were linear in the concentration range of 5~300 ng/ml. The coefficient of variation of the intra- and inter-day precision was below 15%. The coefficient of variation of the accuracy was below 15% in the concentration range investigated. A bioavailability study was performed using the validated HPLC method. Eight healthy male volunteers were orally administered 30 mg of nimodipine. The pharmacokinetic parameters were calculated using WinNonlin. The mean values of AUC_(24hr) was 64.0±31.3 ng·hr/ml, C_(max) was 46.5±31.2 ng/ml, T_(max) was 0.54±0.17 hr and t_(1/2) was 3.03±2.26 hr. The pharmacokinetic parameters and the HPLC method can be used for the design of bioequivalence study of nimodipine.