Evaluation of Hot Deformation and Dynamic Recrystallization Behaviors of Advanced Reduced-Activated Alloy (ARAA)

Sang‑Wook Kim,Hyeon‑Woo Son,Taek‑Kyun Jung,Young‑Bum Chun,Yi‑Hyun Park,Ji‑Woon Lee,Soong‑Keun Hyun 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.4

The hot deformation behavior of advanced reduced-activation alloy (ARAA) was investigated using hot torsion tests. Thefl ow stress decreased as deformation temperature increased and as strain rate decreased. The fl ow behavior demonstratedthe typical dynamic recrystallization (DRX). Based on the constitutive analysis of peak stress, the activation energy for hotdeformation was found to be 330.3 kJ mol −1 . Peak stress was analyzed as a function of the Zener–Hollomon parameter, andcalculated and experimental values were in good agreement. A DRX kinetic model for ARAA was derived with deformationconditions based on the Avrami-type model. It was confi rmed that the volume fraction of dynamically recrystallized grainsincreased as deformation temperature increased and as strain rate decreased. The necklace structure and grain boundarybulging were observed in the deformed microstructure of ARAA. The suggested DRX mechanism for ARAA during hotworking is discontinuous DRX.

생활체육참가정도와 Wellness지수, 생활만족의 관계

김상국(Kim Sang-Kook),이광욱(Lee Kwang-Wook) 한국체육과학회 2005 한국체육과학회지 Vol.14 No.2

The purpose of this study was to examine the relationships among leisure sports participation, wellness inventory and life satisfaction, The subjects were 645 adults(male=348; female=297) aged more than 20 years who participated in community-based leisure sports programs of the fitness clubs in Seoul and Incheon City, Korea, The degree of leisure sports participation; items on the Wellness scale developed and used by Kim Sang-kuk based on Wellness: Concepts and Application developed by Anspaugh et al.(l994); and the Korean version of the Satisfaction with Life scale(SWLS) developed by Diener, Emons, Larsen & Griffin(1985) translated and used by Lee Jong-kil(1992). The validity of the questionnaire was verified through specialists' meeting, the pilot test, and exploratory and confirmatory factor analysis. The reliability of the questionnaire was found to be Cronbach' s α=.66~.83. The methods of statistics used to analyze the collected data were correlation analysis and multiple regression using SPSS WIN 11.5. As a result, the following findings were obtained: First, it was found that the degree of leisure sports participation had an effect on the wellness inventory. That is, participants who participated in the leisure sports program longer, more frequently, and more actively had the higher level of recognition on the wellness inventory than any other group. Second, it was found that the degree of leisure sports participation had an effect on the life satisfaction. That is, participants who participated in the leisure sports program longer, more frequently, and more actively the higher level of recognition on the life satisfaction than any other group. Third, it was found that the wellness inventory had an effect on the life satisfaction. That is, the participants who were highly conscious of physical, social, mental health domains as subfactors of the wellness inventory had the higher level of life satisfaction.

해외사례 벤치마킹에 기반한 국내 CM 대가체계 개선 시사점 도출

김상범,이정대,김재욱,Kim, Sang-Bum,Lee, Jeong-Dae,Kim, Jae-Wook 한국건설관리학회 2008 건설관리 : 한국건설관리학회 학회지 Vol.9 No.1

국내 CM은 2001년 건설산업기본법에 의해 개념과 범위가 정의된 후 지속적인 성장을 계속해 오고 있다. 하지만, 이러한 CM 제도에 기반한 성장에도 불구하고 국내에서의 CM 적용성과는 기대치에 비해 상대적으로 낮은 것으로 나타났다. 그 주요원인의 하나로 국내 CM제도가 책임감리에 비하여 업무범위가 넓지만, 대가기준은 책임감리에 비해 낮기 때문인 것으로 분석되었다. 따라서, 국내 CM 대가체계의 합리적인 기준을 정립하는 것이 시급할 것으로 판단된다. 본 연구에서는 CM 대가체계의 합리적인 기준을 마련하기 위하여 CMAA, ASCE, DOE, DOL 등의 다양한 해외사례 벤치마킹 연구를 통하여 국내 CM 대가체계를 비교하여 대가 상승요인을 추정하고 대가산정 개선방향을 제시하였다. 분석결과 대가수준은 해외에 비하여 현저하게 낮은 수준인 것으로 판단되었으며, 업무범위는 해외와 비교하여 그 폭이 좁으며 획일적인 구조를 가진 것으로 분석되었다. 따라서, 본 연구에서는 글로벌스탠다드에 따르는 국내 CM 대가체계를 개선하기 위하여 실비정액보수가산(Cost Plus Fixed Fee) 방식을 제시하고, 입 낙찰 전반에 걸친 CM 대가체계에 대한 기준(Framework)을 제시하였다. The Korean Construction Industry significantly contributed to the Korean economic development not only by preparing the domestic infrastructure but also by successfully conducting various international projects. However, major incidents such as the collapse of Sung-Su Bridge and Sam-Pung Department Store along with stagnation of Korean Economy have raised questions about underlying systematic problems of the Korean Construction Industry. As a solution to resurrect the Korean Construction Industry, the Construction Management (CM) system introduced in late 1990's and increasingly utilized as an innovative delivery system. Despite of the fast growth of CM, the performance of CM has not been up to the hype and low CM fee has been identified as one of the main reasons of unsatisfactory CM performance. Therefore, this research attempted to propose ways of improving 'CM Fee Guidelines' published by Korean Ministry of Construction and Transportation by conducting a benchmarking study on Global Standards of estimating CM Fee. International organizations benchmarked in this research include CMAA, ASCE, DOL, DOE, etc. Various investigation and analysis revealed that Korean 'CM Fee Guidelines' need to significantly modified comparing to Global Standards. This research also tried to prepare recommendations to improve the CM deliver system focusing on the 'Method of CM Fee Estimation' and Selection of a CM firm as an owner's agent.

Interactions between Chicken Salt-soluble Meat Proteins and Makgeolli Lees Fiber in Heat-induced Gels

Yun Sang Choi,Kwoan Sik Park,Hack Youn Kim,Hyun Wook Kim,Dong Heon Song,Hai Jung Chung,Ju Woon Lee,Cheon Jei Kim 한국축산식품학회 2011 한국축산식품학회지 Vol.31 No.6

The technological effects of Makgeolli lees fiber (0, 0.5, 1.0, 2.0, and 4.0%) on chicken salt-soluble breast meat proteins in a model system on proximate composition, physicochemical properties, and textural properties were investigated. Makgeolli lees fiber was obtained from Makgeolli brew processing, and the by-products showed good dietary fiber. The moisture and ash contents, water holding capacity, redness, yellowness, hardness, and apparent viscosity of chicken salt-soluble meat protein heat-induced gel systems with Makgeolli lees fiber were all higher than the control without Makgeolli lees fiber. However, protein solubility and electrophoretic patterns did not differ among the control and treatments with Makgeolli lees fiber samples. The chicken salt-soluble protein heat-induced gel systems incorporating Makgeolli lees fiber had improved water holding capacity, textural properties, and viscosity due to Makgeolli lees fiber addition. These results suggest that the addition of 4.0% Makgeolli lees fiber to gel is helpful to improve the physical properties of heat-induced gels.

Interactions between Chicken Salt-soluble Meat Proteins and Makgeolli Lees Fiber in Heat-induced Gels

Choi, Yun-Sang,Park, Kwoan-Sik,Kim, Hack-Youn,Kim, Hyun-Wook,Song, Dong-Heon,Chung, Hai-Jung,Lee, Ju-Woon,Kim, Cheon-Jei Korean Society for Food Science of Animal Resource 2011 한국축산식품학회지 Vol.31 No.6

The technological effects of Makgeolli lees fiber (0, 0.5, 1.0, 2.0, and 4.0%) on chicken salt-soluble breast meat proteins in a model system on proximate composition, physicochemical properties, and textural properties were investigated. Makgeolli lees fiber was obtained from Makgeolli brew processing, and the by-products showed good dietary fiber. The moisture and ash contents, water holding capacity, redness, yellowness, hardness, and apparent viscosity of chicken salt-soluble meat protein heat-induced gel systems with Makgeolli lees fiber were all higher than the control without Makgeolli lees fiber. However, protein solubility and electrophoretic patterns did not differ among the control and treatments with Makgeolli lees fiber samples. The chicken salt-soluble protein heat-induced gel systems incorporating Makgeolli lees fiber had improved water holding capacity, textural properties, and viscosity due to Makgeolli lees fiber addition. These results suggest that the addition of 4.0% Makgeolli lees fiber to gel is helpful to improve the physical properties of heat-induced gels.

Selective hydrodechlorination of trichloromethane to dichloromethane over bimetallic Pt-Pd/KIT-6: Catalytic activity and reaction kinetics

Lee, Sae Rom,Cho, Jae Min,Son, Minji,Park, Myung-June,Yong Kim, Woon,Kim, Sang Yob,Bae, Jong Wook Elsevier 2018 Chemical Engineering Journal Vol.331 No.-

<P><B>Abstract</B></P> <P>Selective hydrodechlorination (HDC) of trichloromethane (TCM, CHCl<SUB>3</SUB>) to dichloromethane (DCM, CH<SUB>2</SUB>Cl<SUB>2</SUB>) was studied on the mesoporous bimetallic Pt-Pd/KIT-6 to verify the roles of the active bimetals to catalytic activity and product distribution. The optimal bimetal ratio of 2wt%Pt-0.05wt%Pd on the highly ordered mesoporous KIT-6 calcined at 400°C showed a maximum TCM conversion with DCM yield, and the optimal calcination temperature of Pt-Pd/KIT-6 was mainly responsible for the formation of homogeneously and closely distributed smaller Pt-Pd nanoparticles with higher oxidation states of Pt crystallites supported by XPS and EXAFS analysis. Based on the proposed kinetic models on the optimal Pt-Pd/KIT-6, the competitive reaction mechanisms of the formations of CH<SUB>4</SUB> and monochloromethane (MCM, CH<SUB>3</SUB>Cl) from DCM intermediate can well explain the product distributions. Using the seven different kinetic models, the best model on the basis of the Akaike’s Information Criteria showed the activation energies of the HDC of TCM to be in the range of 18–60kJ/mol. The kinetic model also revealed the inverse relationship between the conversion of TCM and selectivity to DCM. Either an increase of space velocity or decrease of H<SUB>2</SUB>/TCM ratio increased the DCM yield, while there existed the optimal operating conditions. The DCM productivity of 1.5mol-DCM/(g<SUB>cat</SUB>·h) was achievable at the highest space velocity and lowest H<SUB>2</SUB>/TCM ratio under a specific reaction condition of 190°C and 0.1MPa.</P> <P><B>Highlights</B></P> <P> <UL> <LI> HDC of TCM to DCM was studied on the mesoporous 2wt%Pt-0.05wt%Pd/KIT-6. </LI> <LI> At an optimal calcination T=400°C, a maximum DCM yield was obtained. </LI> <LI> Close interactions of smaller Pt-Pd nanoparticles with higher oxidation states are beneficial for a higher DCM yield. </LI> <LI> The kinetic model based on LHHW was well fitted with experimental results. </LI> <LI> Higher DCM productivity was achievable at the highest SV and lowest H<SUB>2</SUB>/TCM ratio. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Reconstruction of Large Defects in the Perineal Area Using Multiple Perforator Flaps

Sung, Ki Wook,Lee, Won Jai,Yun, In Sik,Lee, Dong Won Korean Society of Plastic and Reconstructive Surge 2016 Archives of Plastic Surgery Vol.43 No.5

Background Perineal defects are commonly encountered during the treatment of conditions such as malignancy, infectious disease, and trauma. Covering large defects in the perineal area is challenging due to its complicated anatomy and the need for functional preservation. Methods Fourteen patients who underwent reconstructive surgery with multiple perforator flaps for defects >$100cm^2$ in the perineal area were included in this retrospective cohort study. Characteristics of the perforator flap operation and postoperative outcomes were reviewed. Results Reconstruction was performed using 2 perforator flaps for 13 patients and 3 perforator flaps for 1 patient. Internal pudendal artery perforator flaps were mainly used for covering the defects. The average defect size was $176.3{\pm}61.8cm^2$ and the average size of each flap was $95.7{\pm}31.9cm^2$. Six patients had minor complications, such as wound dehiscence and partial necrosis of the flap margin, which were corrected with simple revision procedures. Conclusions Multiple perforator flaps can be used to achieve successful reconstructions of large perineal defects that are difficult to reconstruct with other coverage methods.

On the Fragile Relationship Between El Niño and California Rainfall

Lee, Sang‐,Ki,Lopez, Hosmay,Chung, Eui‐,Seok,DiNezio, Pedro,Yeh, Sang‐,Wook,Wittenberg, Andrew T. American Geophysical Union 2018 Geophysical research letters Vol.45 No.2

<P>The failed influence of the 2015-2016 El Nino on California rainfall has renewed interest in the relationship between El Nino and U.S. rainfall variability. Here we perform statistical data analyses and simple model experiments to show that sufficiently warm and persistent sea surface temperature anomalies (SSTAs) in the far eastern equatorial Pacific are required to excite an anomalous cyclone in the North Pacific that extends to the east across the U.S. West Coast and thus increases rainfall over California. Among the four most frequently recurring El Nino patterns considered in this study, only the persistent El Nino, which is often characterized by the warm SSTAs in the far eastern equatorial Pacific persisting throughout the winter and spring, is linked to such extratropical teleconnection patterns and significantly increased rainfall over the entire state of California. During the last 69 years, only three of the 25 El Nino events (i.e., 1957-1958, 1982-1983, and 1997-1998) are clearly identified as the persistent El Nino. In addition, the monthly rainfall variance explained by El Nino is less than half that caused by internal variability during the 25 El Nino. Therefore, the rarity of persistent El Nino events combined with the large influence of internal variability effectively explains the fragile relationship between El Nino and California rainfall.</P>

Supplementary Trial for the Effective Utilization of a Methane Gas Producing Tank System

Lee, Jae-Heung,Soh, Chin-Thack,Kim, Sang-Jun,Lee, Chong-Wook INSTITUTE OF TROPICAL MEDICINE YONSEI UNIVERSITY 1978 YONSEI REPORTS ON TROPICAL MEDICINE Vol.9 No.1

Hinokitiol enhances TRAIL-cell death by up-regulation of death receptors via inhibition of autophagy flux

Sung Wook Kim,Ju Hee Lee,Ji Hong Moon,Yang Gyu Park,Uddin MD. Nazim,Jae Kyo Jeong,You Jin Lee,Jae Won Seol,Sang Youel Park 한국실험동물학회 2015 한국실험동물학회 학술발표대회 논문집 Vol.2015 No.8