Effect of Mn and C on Age Hardening of Fe–Mn–Al–C Lightweight Steels

Sung‑Won Park,Jun Young Park,Kyong Mox Cho,Jae Hoon Jang,Seong‑Jun Park,Joonoh Moon,Tae‑Ho Lee,Jong‑Ho Shin 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.3

The effects of Mn and C content on the age hardening of Fe–Mn–Al–C lightweight steels, which have austenitic or duplex(austenite and ferrite) microstructures, were investigated. An increase in Mn content induced a delay of the age hardeningthat is caused by the formation of intra-granular κ-carbides. In order to interpret the effect of Mn content, first-principlescalculations were conducted using the supercells of Fe24Al8C8,Fe24Al8C7,Fe24(Al7Mn)C8, and Fe24(Al7Mn)C7. The calculationsshowed that an increase in Mn content could be the source of the delay of the intra-granular κ-carbide formation bysuppressing C atom’ occupation of the vacancy at the body-centered site of L12. An increase in C content accelerated theformation of intra-granular κ-carbides, which induced the intense age hardening, and coarse inter-granular κ-carbides, whichresulted in significant decrease in impact absorbed energy due to inter-granular fracture.

Detection of benzalkonium chloride on glass surfaces using silver nanoparticles

Nguyễn Hoàng Ly,Phuong-Dong Nguyen,Sang Jun Son,이철민,Soonmin Jang,주상우,Kyungjoo Kim,Jiseon Choi,Ye-eun Joo,Jung Il Lee 대한화학회 2022 Bulletin of the Korean Chemical Society Vol.43 No.2

Raman reporter-based surface-enhanced Raman scattering (SERS) has been used to investigate the detection of one member of a class of the cationic surfactant quaternary ammonium compounds, alkyl dimethyl benzyl ammonium chloride, also known as benzalkonium chloride (BAC). For this study, SERS was performed using silver nanoparticles (AgNPs). Density functional theory (DFT) of BAC on Ag6 clusters was introduced to estimate binding at the level of the B3LYP/LANL2DZ basis sets. As the chain length increased from n = 8 to 18, the binding energies were expected to increase by 2.1 kcal/mol. Methylene blue (MB) Raman reporter molecules were subsequently treated on BAC thin-film-covered glass surfaces. Atomic force microscopy (AFM) images were used to determine the coverage of BAC on the glass, and field-emission electron microscope (FE-SEM) images revealed the surface morphologies of the SERS substrates. A standard calibration curve was prepared to quantify BAC within a concentration range of 0.0036805 to 36?805?ppm (r2?≥?0.99), according to the BAC-correlated SERS intensities of MB Raman peaks at ~1620?cm?1 adsorbed on AgNPs. A molecular dynamics (MD) simulation supported strong adsorption of BAC on glass surfaces.

경부고속철도건설사업 성과평가

송성태(Sung Tae Song),최문규(Moon Kyu Choi),박상구(Sang Gu Park),장호환(Ho Hwan Jang),차효정(Hyo Jung Cha) 한국철도학회 2012 한국철도학회 학술발표대회논문집 Vol.2012 No.5

1992년 첫 삽을 뜨면서 시작한 경부고속철도건설사업이 2004년 4월, 1단계 개통을 한데 이어 지난 2010년 11월 완전 개통하였다. 경부고속철도 개통으로 경부축 지역의 2시간대 서비스 제공을 통한 국토의 균형발전 촉진 및 여가·관광사업 활성화, 기술발전, 환경비용 및 에너지 절감 등 긍정적인 효과를 이룬 반면, 잦은 기본계획 변경으로 인한 사업비 및 사업기간의 증가, 현실과 맞지 않은 설치기준으로 인한 과잉설계 문제 등 부정적 효과도 초래했다. 본 연구를 통해 사업추진 단계별 주요 이슈에 대해 객관적인 시각으로 문제점을 분석하고 시사점을 도출함으로써, 현재 추진하고 있는 호남고속철도와 수도권고속철도 사업에서는 시행착오를 줄이고 사업을 효율적으로 추진하는데 활용하고자 한다. Launched in 1992, the Gyeung-Bu High Speed Railway (HSR) was fully opened in November 2010 following the partial opening of the first phase in April 2004. Since the opening it has made tremendous achievements, including but not limited to, technical innovation, balanced regional development, growth of leisure and tourism industries, and savings of environmental costs and energy. On the other hand, it has brought negative effects such as increase in project time and cost by frequent changes of the basic plan and over-design based on unrealistic criteria. In this study we will analyze major issues that occurred at each stage of the Gyeong-Bu HSR project and draw implications. Thus, this study will enhance to efficiently implement the Ho-Nam and Seoul Metropolitan HSR project through minimizing possible trials and errors.

제주 성상 S/S MTr #1 행원 풍력단지 전압해석

김상준(Sang-Jun Kim),조민호(Min-Ho Cho),윤기갑(Gi-Gab Yoon),장상옥(Sang-Ok Jang),안정식(Jeong-Shik Ahn) 대한전기학회 2003 대한전기학회 학술대회 논문집 Vol.2003 No.11

성인에서 발생한 발진성 가성 혈관종증

서상희 ( Sang Hee Seo ),장호선 ( Ho Sun Jang ),목혜수 ( Hye Soo Mok ),김성준 ( Sung Jun Kim ),김병수 ( Byung Soo Kim ),김문범 ( Moon Bum Kim ),오창근 ( Chang Keun Oh ),권경술 ( Kyung Sool Kwon ) 대한피부과학회 2007 대한피부과학회지 Vol.45 No.8

Background: Eruptive pseudoangiomatosis (EPA) is a rare, benign, spontaneously regressing childhood exanthem. It is characterized by the sudden onset of several bright red angioma-like papules surrounded by pale halos with a distinct histopathology from true angiomas. Objective: This study was performed to evaluate the clinical and histopathologic characteristics of EPA occuring in adults. Methods: Ten adult patients who visited Pusan National University Hospital and Mok Hye-SooㆍJang Ho-Sun Dermatology Clinic from March 2005 to September 2006 were evaluated. We prospectively evaluated the sex, age, onset season, past medical history including immunosuppressive abnormalities, systemic disorders and other diseases including allergies. We also investigated the relations of mosquito biting, patients` occupations and outdoor activities to occurrence of EPA. In addition, simultaneous occurrence in family members, the clinical, histopathologic, laboratory findings, disease courses and responses to treatment were evaluated. Based on medical records, photographs and pathologic slides, we retrospectively diagnosed another 20 EPA patients suspected as insect bite from October 2003 to March 2005. The same questions were inquired as for the 10 patients who prospectively underwent evaluation. Results: In the study, female predominance (76.7%) was observed and the average age of onset was 54.2 years. Interestingly, there was no child patient during the period of study. Multiple, 2∼5 mm sized, red angiomatous papules surrounded by pale halos occurred on exposed areas such as the arms (86.7%), legs (50%), and face (46.7%), although it could also occur to a non-exposed area. EPA occuring in adults usually appeared in summer (80%). The mean disease duration was 3.4 weeks. Although EPA spontaneously regressed, it had the potential of recurrence (46.7%). Histopathologic findings showed dilated dermal blood vessels without the evidence of increase in numbers, and perivascular lymphocytes infiltration. Inside the lumen of dermal blood vessels, plump endothelial cells were found. Conclusion: EPA occuring in adults usually happened to exposed sites in summer, so it can be misdiagnosed as insect bite. We suggest that dermatologists should be concerned about EPA in adults and conduct further investigation to have a better understanding of the disease. (Korean J Dermatol 2007;45(8):797∼803)

플라즈마 정보인자를 활용한 SiO₂ 식각 깊이 가상 계측 모델의 특성 인자 역할 분석

장윤창,박설혜,정상민,유상원,김곤호,Jang, Yun Chang,Park, Seol Hye,Jeong, Sang Min,Ryu, Sang Won,Kim, Gon Ho 한국반도체디스플레이기술학회 2019 반도체디스플레이기술학회지 Vol.18 No.4

We analyzed how the features in plasma information based virtual metrology (PI-VM) for SiO2 etching depth with variation of 5% contribute to the prediction accuracy, which is previously developed by Jang. As a single feature, the explanatory power to the process results is in the order of plasma information about electron energy distribution function (PIEEDF), equipment, and optical emission spectroscopy (OES) features. In the procedure of stepwise variable selection (SVS), OES features are selected after PIEEDF. Informative vector for developed PI-VM also shows relatively high correlation between OES features and etching depth. This is because the reaction rate of each chemical species that governs the etching depth can be sensitively monitored when OES features are used with PIEEDF. Securing PIEEDF is important for the development of virtual metrology (VM) for prediction of process results. The role of PIEEDF as an independent feature and the ability to monitor variation of plasma thermal state can make other features in the procedure of SVS more sensitive to the process results. It is expected that fault detection and classification (FDC) can be effectively developed by using the PI-VM.

YMCA 체육의 역사적 함의

김영훈(Kim, Young-hun),장성호(Jang, Sung-Ho),박윤기(Park, Yun-Ki) 용인대학교 무도연구소 2012 武道硏究所誌 Vol.23 No.1

이 연구는 역대 YMCA 체육을 토대로 하여 구체적으로 살펴보고자 한다. 이에관해 생활체육 활성화 방안 모색을 제시하는데 논의 및 결론을 도출하였다. 이는 다음과 같이 확인할 수 있다. 첫째, 한국에서의 YMCA운동은 1899년 경성에서 선교활동을 시작되었다. 둘째, YMCA의 전인교육정신인 지(智)·덕(德)·체(體)의 정신과 통하는 정신으로서 비폭력, 민주주의의 실천교육과 상통하는 정신이었다. 셋째, 이상재의 교육사상은 인간의 본질적인 면에 치중하여 올바른 인격체로 양성하는 것으로 지·덕·체의 전인적 교육이었음 알 수 있었다. 넷째, 서울 YMCA의 창립과 역사적 배경을 보면 서울YMCA는 1903년 10월 28일 창립하였다. 다섯째, 서울YMCA를 도입, 회원들에게 지도한 스포츠로는 야구, 농구, 배구, 축구, 유도, 검도, 체조 등이 있었다. 이상과 같이 종합해 볼 때, 역대 YMCA 체육의 역사에서 보이듯이 그 정책을 통해 한국생활체육의 활성화를 위한 방안 모색에 따른 정체성을 제시할 수 있는 것이다. This research is looked at concretely is based on the generation of YMCA physical training. It derive a discussion and conclusion to grope a plan to activate living physical training. This can be confirmed by the following essay. First, the YMCA exercise in Korea started in Gyeong-sun, 1899 as a missionary activity. Second, the mind of former education of YMCA’s just·morality·formality was a mind connected to the communicating with anti-violence, democratic practice education. Third, Lee Sang-Jea’s educational method is to bring up the personality to the right side valued on true nature of a human being, which indicates that his educational method is for the whole man. Fourth, looking at the foundation and historical backround, Seoul YMCA was established on 28th October 1903. Fifth, sports that Seoul YMCA guided to members were baseball, basketball, volleyball, football, judo, kendo, gymnastics etc. To round up all the above statements, the identity following a plan to activate Korea living P.T can be derived through the policy as seen in YMCA physical training’s history in generations.

Case Report : Arteriovenous malformation in uterine cervix during pregnancy

( Sung Mee Kim ),( Won Kyu Jang ),( Joon Cheol Park ),( Jeong Ho Rhee ),( Jong In Kim ),( Jin Gon Bae ) 대한산부인과학회 2014 Obstetrics & Gynecology Science Vol.57 No.2

As the development of Doppler ultrasonography, many cases of uterine arteriovenous malformation (AVM) have beed diagnosed. But there is no case of cervical AVM in pregnant uterus. We present a 33-year-old pregnant woman who was diagnosed with AVM of the uterine cervix during the midtrimester. Color Doppler sonography and magnetic resonance image were used for diagnosis. We performed Cesarean section because of the risk of massive bleeding from the cervical AVM at 34 weeks` gestation. This is the first case of cervical AVM during pregnancy with a successful outcome and an uneventful postpartum course.

Severe Spastic Dysarthria Due to Bilateral Injury of the Corticobulbar Tract in a Patient with Traumatic Brain Injury

Jang, Sung Ho,Seo, You Sung Wolters Kluwer Health, Inc. All rights reserved. 2016 AMERICAN JOURNAL OF PHYSICAL MEDICINE & REHABILITA Vol.95 No.10

Structural Performance Evaluation of a Precast PSC Curved Girder Bridge Constructed Using Multi-Tasking Formwork

Sung-Jae Kim,Jang-Ho Jay Kim,Seong-Tae Yi,Norhazilan Bin Md Noor,Sung-Chul Kim 한국콘크리트학회 2016 International Journal of Concrete Structures and M Vol.10 No.3

Recently, advanced transit systems are being constructed to reduce traffic congestions in metropolitan areas. For these projects, curved bridges with various curvatures are required. Many curved bridges in the past were constructed using aesthetically unpleasant straight beams with curved slabs or expensive curved steel box girders with curved slabs. Therefore, many recent studies have been performed to develop less expensive and very safe precast prestressed concrete (PSC) curved girder. One method of reducing the construction cost of a PSC curved girder is to use a reusable formwork that can easily be adjusted to change the curvature and length of a girder. A reusable and curvature/dimension adjustable formwork called Multi-tasking formwork is developed for constructing efficient precast PSC curved girders. With the Multi-tasking formwork, two 40 m precast PSC box girders with different curvatures were constructed to build a two-girder curved bridge for a static flexural test to evaluate its safety and serviceability performance. The static flexural test results showed that the initial cracking load was 1400 kN, exceeding the design cracking load of 450 kN. Also, the code allowed deflection of 50 mm occurred at a load of 1800 kN, verifying the safety and serviceability of the precast PSC curved bridge constructed using the multi-tasking formwork.