Hydrogen Behavior in Ti-Added Reduced Activation Ferritic-Martensitic Steels

Kang‑Mook Ryu,Dae Geon Lee,Joonoh Moon,Chang‑Hoon Lee,Tae‑Ho Lee,Jae Sang Lee,Dong‑Woo Suh 대한금속·재료학회 2021 METALS AND MATERIALS International Vol.27 No.3

Hydrogen behavior and corresponding mechanical degradation were examined in TaTi-RAFM and EUROFER97 steels. Increased Ta content with Ti addition decelerates the hydrogen diffusion but increases the solubility in the lattice. It ismainly led by the higher fraction of Ta-rich MC carbides and dislocation density in TaTi-RAFM steel. Overall activationenergy of hydrogen trapping of investigated steels is evaluated to be 25.3 ~ 25.6 kJ/mol in the tempered condition. The activationenergy increases to nearly 30 kJ/mol when the steels are re-austenitized and quenched. Higher activation energy withincreased dislocation density indicates that the dislocation provides for trap site with higher activation energy than Ta-richMC carbide. Mechanical degradation by hydrogen with respect to the yield strength, tensile strength and uniform elongationcould not be observed in all investigated steels. The presence of hydrogen only has influence on the loss of post-uniformelongation. For a given charging time, the loss of post-uniform elongation is more remarkable in TaTi-RAFM steel due tothe larger hydrogen uptake.

성인 쇄골 간부 골절에서 두 가지 수술적 치료군 간의 결과 비교: 금속판을 이용한 관혈적 정복 및 내고정술과 Steinmann Pin을 이용한 경피적 겸자 정복 및 골수강내 고정술의 결과 비교

허성식 ( Sung Sik Ha ),심재천 ( Jae Chun Sim ),홍기도 ( Ki Do Hong ),김재영 ( Jae Young Kim ),강정호 ( Jung Ho Kang ),박광희 ( Kwang Hee Park ) 대한골절학회 2007 대한골절학회지 Vol.20 No.3

목적: 성인 쇄골 간부 골절에서 금속판을 이용한 관혈적 정복 및 내고정술과 Steinmann pin을 이용한 경피적 겸자 정복 및 골수강내 고정술의 결과를 분석하여 비교하였다. 대상 및 방법: 2002년 3월부터 2006년 1월까지 본원에서 치료한 총 68예의 쇄골 간부 골절을 대상으로 하였으며, 금속판을 이용한 33예, Steinmann pin을 이용한 35예의 치료 결과를 분석하였다. 최종 결과 판정은 강 등의 기준에 의한 임상적 결과와 방사선학적 골유합 기간으로 하였고, 수술 시간을 비교하였다. 결과: 임상적 결과는 우수 이상의 예가 금속판을 이용한 군의 경우 총 33예 중 29예로 88%, Steinmann pin을 이용한 군의 경우 총 35예 중 32예로 91%의 결과를 보였다. 방사선학적 골유합 시기는 각각 평균 8.9주와 9.1주였고, 수술 시간은 금속판 군에서 평균 72분, Steinmann pin 군에서 평균 18분이었다. 결론: 성인 쇄골 간부 골절의 치료에 있어 금속판을 이용한 수술 군과 Steinmann pin을 이용한 수술 군은 임상적, 방사선학적 결과 면에서 통계학적으로 큰 차이를 보이지 않았으나, Steinmann pin을 이용한 수술 군에서 수술 시간 및 회복기간의 감소로 인하여 경제적인 면과 수술반흔의 감소에 따른 미용적인 면에서 더 만족스런 결과를 보였다. Purpose: To evaluate the results between open reduction and internal fixation with the plate and percutaneous reduction by towel clip and intramedullary fixation with Steinmann pin for clavicle shaft fractures in adult. Materials and Methods: We have studied the results in 33 cases with the plate. 35 cases with the Steinmann pin among total 68 cases of clavicle shaft fracture. The patients were followed up over a period of at least 12 months. The final postoperative outcome was analyzed with the clinical outcomes using Kang`s criteria. radiological union time and operation time. Results: The clinical outcome that was good or excellent according to the Kang`s criteria showed a distribution of 88% in the group using the plate with 29 cases out of total 33 cases. 91% in the group using the Steinmann pin with 32 cases out of total 35 cases. The mean radiological union time was 8.9 weeks in the group using the plate. 9.1 weeks in the group using Steinmann pin. The mean operation time was 72 minutes in the group using the plate, whereas was 18 minutes in the group using Steinmann pin. Conclusion: In the treatment of adult clavicle shaft fracture. two groups did not show a significant statistical difference in clinical and radiological outcomes. However, the operation time and postoperative functional recovery was significantly shorter and faster in the group using Steinmann pin. Additionally economic and cosmetic aspect was more satisfactory in the group using Steinmann pin.

질소이온주입에 의한 알루미늄의 표면개질특성

강혁진(Hyuk-Jin Kangㅠ),안성훈(Sung-Hoon Ahn),이재상(Jae-Sang Lee),김경균(Kyung-Gun Kim) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.5

The research on surface modification technology has been advanced to improve the properties of engineering materials. Ion implantation is a novel surface modification technology to enhance the mechanical, chemical and electrical properties of substrate’s surface using accelerated ions. In this research, nitrogen ions were implanted into aluminum substrates which would be used for mold of rubber materials. The composition of nitrogen ion implanted aluminum alloy and nitrogen ion distribution profile were analyzed by Auger Electron Spectroscopy (AES). To analyze the modified surface, properties such as hardness, friction coefficient, wear resistance, contact angle, and surface roughness were measured. Hardness of ion implanted specimens was higher than that of untreated specimens. Friction coefficient was reduced, and wear resistance was improved. From the experimental results, it can be expected that ion implantation of nitrogen enhances the surface properties of aluminum mold.

지방정부의 목표관리와 예산관리의 연계를 위한 모형 연구 - 부산광역시를 중심으로 -

박영강 ( Park Young-kwang ),강성권 ( Kang Sung-kwon ),강재호 ( Kang Jae-ho ),이강웅 ( Lee Gang-woong ),이종필 ( Lee Jong-pil ) 부산연구원 2004 연구보고서 공동연구 Vol.2004 No.0

There are two recent trends in improving performance of local government: The one is result-oriented budget system developed in European countries; the other is Management By Objectives (MBO) carried out in the United States. Japanese local governments, in which changes in budget system occur relatively slow, attempt to introduce performance-oriented administrative evaluation system while in Korea, Seoul local government makes a move to improve MBO by including performance-based budget system. Busan Metropolitan City has drawn up partially performance-based budgets(PB) in four areas (Financial Management Division, Environment Bureau, Busan Cultural Center and the Special Accounts for Transportation Project) since 2003, but budget system in general remains the same because, the performance proposals in budgets were merely linked with general directors and managers' objectives under MBO. The purpose of this study is to examine expected problems in introducing objective- budget connection system and to find alternatives and implications by analyzing the cases of three cities: Seoul of Korea, Suginami-Gu of Tokyo, Japan, City of Phoenix, U.S.A. Results showed that Suginami-Gu's administrative evaluation system was less effective than that of Phoenix mixing with PB and MBO. That of Seoul having a similar model to Phoenix budget system was turned out to be less effective. This means experience and technique of evaluation are more important in the efficiency of evaluation model rather than structural factors of evaluation model itself. Based on these results, we proposed basic directions of an objective-budget connection system to improve the efficiency of the system and institutional and technical alternatives as follows: First of all, when Korean local governments look for a new objective-budget connection system, Seoul's performance-management model will be a major alternative. Suginami-Gu's administrative evaluation system can be easily applicable, but it is not yet linked with personal compensation and promotion so that it may be passive in developing an evaluation index and its techniques. There for the operational experience and model of Phoenix having a similar model to Seoul's would be helpful. When we introduce a performance-management system of Seoul, we may have to consider the following institutional and technical alternatives in order to increase its efficiency: ① It is required to renovate the structure of Seoul's performance-based budgetary system. The case of Phoenix would be an alternative. ② To develop a performance index corresponding to the characteristics of Busan, it is needed to keep close bondage between evaluation-in-charge department and project departments, and to obtain external institutions' support and NGO's involvement. In this process, an organization's mission should be identified. In the setting up managers' personal goals require a concrete and diverse index like Phoenix's. ③ For performance evaluation as a core function of object-budget connection system, it is required to reinforce evaluation-in-charge department, to establish an adequate evaluation procedure and to carry out systematic training for supervisors' evaluation skill improvement and active participation of staff members. ④ To promote the efficiency of connection model, the inducement measure should be strengthened and its application should be expanded gradually. In Busan's case, bonus is offered as a means of the inducement. As the inducement effect of bonus is not high, the standard for bonus distribution should be varied to enhance the inducement effect. Structural renovation of budget system in the proposed alternatives requires central government's changes in the guide on the compilation of budget, but it can be done on the local government level. Reorganization of the evaluation agency and financial inducement structure can be achieved through local government's individual revision of ordinances and regulations. Thus, institutional restriction is unlikely to occur in the process of introducing a new objective-budget system. Those alternatives are considered as basic contents when Busan Metropolitan City introduces a new system mixing MBO with PB. But supplementary case studies on each country's budgetary structure and related financial system will be desirable. To realize these alternatives, it is required to overcome resistance from members of an organization and to secure political force to settle down the new system. It is desirable for a mayor of local government to have his/her confidence to pursue administrative reform and to obtain supports from community's council and opinions at the same time. This study is jointly conducted by Busan Development Institute and Dong-eui University in the form of Research-Academia consortium. Professor Kang, Jae-Ho of Busan National University participated in the project as a special researcher. We appreciate the advice and help of those who offered relevant materials from domestic and overseas. Especially, we would like to express our sincere thanks director Sakae Sueki and his staff members in the Department of Planning at Suginami-Gu of Tokyo, Professor Hiroshi Sato of Chuogakuin University in Japan, and Mr. Bob Wingenroth, City Auditor and his Deputy City Auditors, Ms. Diane L. Artrip, JoAnne M. Dukeshire in Phoenix, Arizona.

동 전차선(Cu) 및 동합금 전차선(CuSn)의 굽힘피로 수명 평가

김용석(Yongseok Kim),리하오창(Haochuang Li),강민성(Minsung Kang),구재민(Jae-Mean Koo),석창성(Chang-Sung Seok),이기원(Kiwon Lee),권삼영(Sam-Young Kwon) Korean Society for Precision Engineering 2012 한국정밀공학회지 Vol.29 No.12

Contact wire is one of the most important components supplying electricity to railroad cars. At the beginning of the research on contact wire, wear problem caused by friction between contact wire and pantograph was considered even more important issue for the failure of contact wire. However, since several fatigue fractures were reported from Shinkansen in Japan, fatigue fracture has become another important issue for the failure of contact wire. Despite of its importance, standard of the fatigue test of contact wire has not been established yet. Thus, fatigue characteristics of contact wire is very difficult issue to evaluate quantitatively. Hence, in this study, test method simulating operating conditions of contact wire by Minsung Kang and etc. is used to evaluate the fatigue characteristics of copper alloy contact wire. Also, test results is compared with the result of Minsung Kang’s research on pure copper contact wire.

Locking Compression Plate를 이용한 전위성 쇄골 간부 골절의 수술적 치료

정남식,홍기도,하성식,박성준,강정호,심재천,Chung, Nam-Sik,Hong, Ki-Do,Ha, Sung-Sik,Park, Sung-Joon,Kang, Jung-Ho,Sim, Jae-Cheon 대한정형외과스포츠의학회 2006 대한정형외과스포츠의학회지 Vol.5 No.1

목적: 전위성 쇄골 간부 골절의 치료로 관혈적 정복술 후 LCP를 사용하여 내고정을 시행한 환자를 대상으로 방사선학적, 임상적 결과를 분석하여 전위성 쇄골 간부 골절의 치료에 있어서 LCP의 유용성을 알아보고자 하였다. 대상 및 방법: 2003년 5월부터 2004년 11월까지 본원에서 쇄골 간부 골절에 대해 LCP를 이용한 관혈적 정복, 금속내 고정술을 시행하고 6개월 이상 추시가 가능하였던 26례를 대상으로 하였다. 수술 후 최종 평가는 방사선 결과와 fang s criteria를 이용한 임상적 결과로 분석하였다. 결과: 수술 후 평균 9.3주에 모든 예에서 지연유합 없이 골유합 되었으며 임상적으로 Kangs criteria에 따라 구분한 결과, 우수 이 상이 22례로 나타났다. 특히, 견관절 운동은 상완골 골절이 동반된 두 경우를 제외한 24례에서 2.9주내에 정상 범위로 빠른 회복을 보였다. 합병증으로는 견관절 운동 장애 2례, 수술 절개 부위의 켈로이드 형성 1례였으며 그 이외에 다른 주요 합병증은 없었다. 결론: 전위성 쇄골 간부 골절에서 LCP를 이용한 관혈적 정복 및 금속내 고정술은 기존의 금속판에 비해 수술 후 합병증을 줄이고 효과적인 골유합과 조기 견관절 운동에 도움을 줄 수 있는 좋은 치료 방법 중 하나라고 사료된다. Purpose: To assess the effectiveness of the Locking compression plate (LCP) after open reduction for the treatment of the displaced clavicular shaft fracture, the clinical and radiologic outcome of the patients who were managed with the LCP for internal fixation after open reduction has been analyzed. Materials and Methods: We reviewed 26 cases with a displaced clavicular shaft fracture treated by internal fixation using Locking compression plate after open reduction between May 2003 and November 2004. The patients were followed up for at least six months period, and final postoperative outcome was evaluated using clinical results based on Kang's criteria, radiologic signs of fusion. Results: All fractures united by an average of 9.3 weeks without delayed union and showed fast recovery of motion fraction and shoulder function. In addition,24 cases without the fractures of proximal humerus recovered to normal range of shoulder notion within 2.9 weeks. Clinically, according to Kang's criteria, the outcome was good or better in 22 patients. The complications included shoulder joint dysfunction in two cases and keloid formation in one case, and no other complications were observed. Conclusion: The internal fixation using LCP for the treatment of displaced clavicular shaft fracture is a safe, reliable method of treatment, with few complications, and offers rapid recovery of shoulder joint function and bone union.

급성 심근경색 후 심인성쇽의 발생에 관여하는 위험인자

전두수(Doo Soo Jeon),정해억(Hae Uk Chung),승기배(Ki Bae Seung),강동헌(Dong Hun Kang),김상우(Sang Wo Kim),김용주(Young Ju Kim),채장성(Jang Sung Chae),김재형(Jae Hyung Kim),홍순조(Soon Jo Hong),최규보(Kyu Bo Choi) 대한내과학회 1996 대한내과학회지 Vol.50 No.6

N/A Objectives: Cardiogenic shock resulting from acute myocardial infarction is a serious complication with high mortality. The early identification of patients at high risk of developing post-infarction cardiogenic shock might allow early intervention in an attempt to prevent cardiogenic shock and to reduce the mortality due to cardiogenic shock. The aim of the present study was to examine the risk factors of inhospital development of cardiogenic shock among patients with acute myocardial infarction. Methods: We studied 152patients with acute myocardial infarction who were admitted to Kang-Nam St. Mary's hospital within 24hours after the onset of chest pain and did not have cardiogenic shack on admission between March 1991 and May 1994. Clinical data of these patients were analyzed. Results: Of 152patients, 17(11.1%) developed cardiogenic shock during their hospital stay. Cardiogenic shock developed in 53% of cases more than 24hours after admission. 82.4% of patients with cardiogenic shock died whereas a 6.7% in-hospital mortality was found among patients without cardiogenic shock. Multivariate regression analysis that controlled for variables affecting incidence of postinfarction cardiogenic shock showed that independent risk factors for in-hospital cardiogenic shock were history of myocardial infarction (adjusted relative odds[RO]=5.294, 95% confidence interval[CI]=2.149 to 13.041); heart failure on admission (RO=3.344, 95% CI=1.738 to 6.432); hyperglycemia (>180mg/dl) in non-diabetic patients (RO=3.270, 95% CI=1,590 to 6.727); age over 70 year old (RO=2.912, 95% CI= 1.816 to 4.668); ST deviation over 4mm (RO=2.417, 95% CI=1.225 to 4.767); peak LDH level greater than 1600U/ml (RO=1.154, 95% CI=1.080 to 1.233). Patients with one independent risk factor had an estimated probability of 10.5% for developing inhospital cardiogenic shock; patients with two independent risk factors, 48.5%, patients with three risk factors, 65.0% patients with four risk factors, 65.7% patients with five risk factors, 67.2%. Conclusion: Of post-infarction cardiogenic shock during admission, 53% developed more than 24hours after admission. The more independent risk factors on admission for inhospital cardiogenic shock patients with acute myocardial infarction had, the more likely in-hospital cardiogenic shock developed.

Alpha-lipoic acid protects human dopaminergic neuronal cells against hydrogen peroxide-induced cell injury by inhibiting autophagy and apoptosis

Kang, Kyeong-Rok,Kim, Jae-Sung,Kim, Tae-Hyeon,Seo, Jeong-Yeon,Lim, HyangI,Park, Jong-Hyun,Yang, Kwang Yeol,Yu, Sun-Kyoung,Kim, Heung-Joong,Kim, Chun Sung,Chun, Hong Sung,Lee, Dong-Seol,Park, Joo-Cheol The Korean Academy of Oral Biology 2021 International Journal of Oral Biology Vol.46 No.1

Alpha-lipoic acid (ALA) is a naturally occurring antioxidant and has been previously used to treat diabetes and cardiovascular disease. However, the autophagy effects of ALA against oxidative stress-induced dopaminergic neuronal cell injury remain unclear. The aim of this study was to investigate the role of ALA in autophagy and apoptosis against oxidative stress in the SH-SY5Y human dopaminergic neuronal cell line. We examined SH-SY5Y phenotypes using the 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromide assay (cell viability/proliferation), 4′,6-diamidino-2-phenylindole dihydrochloride nuclear staining, Live/Dead cell assay, cellular reactive oxygen species (ROS) assay, immunoblotting, and immunocytochemistry. Our data showed ALA attenuated hydrogen peroxide (H2O2)-induced ROS generation and cell death. ALA effectively suppressed Bax up-regulation and Bcl-2 and Bcl-xL down-regulation. Furthermore, ALA increased the expression of the antioxidant enzyme, heme oxygenase-1. Moreover, the expression of Beclin-1 and LC-3 autophagy biomarkers was decreased by ALA in our cell model. Combined, these data suggest ALA protects human dopaminergic neuronal cells against H2O2-induced cell injury by inhibiting autophagy and apoptosis.

[Free Paper] Initial experience with robotic thyroidectomy for the management of Graves disease

Jae Hyun Park,Cho-Rok Lee,Seulkee Park,Jun Soo Jeong,Sang-Wook Kang,Jong Ju Jeong,Kee-Hyun Nam,Woong Youn Chung,Cheong Soo Park 대한외과학회 2011 대한외과학회 학술대회 초록집 Vol.2011 No.11

Effect on Treatments Combined Fog System with Foliage Spray of CaCl₂ to Reduce Water Core in an Apple Cultivar ‘Hongro’

Sung-Hee Lee,Jae-Wung Lee,Hyun-Man Shin,Ik-Jei Kim,BoGoo Kang,Ki Yeol Lee 한국원예학회 2015 한국원예학회 학술발표요지 Vol.2015 No.5