Controlled infiltration profile of SiC coating layer on graphite by Si vapor deposition reaction

Kuk-Jin Hwang,Si-Young Bae,Kyoung-Ho Kim,Yoon-Cheol Lee,Jung-Tae Hwang,Heesoo Lee,Seong Min Jeong,Myung-Hyun Lee 한양대학교 세라믹연구소 2019 Journal of Ceramic Processing Research Vol.20 No.2

SiC-coated graphite was successfully fabricated at different temperatures (1300-1600 oC) through a silicon vapor depositionreaction (Si-VDR) process. Si powder was used for the Si source of the SiC coating layers. When Si powder was evaporatedat high temperature near the melting point of bulk Si, Si gases are moved and changed into Si liquid at the surface of thegraphite. The high-temperature process facilitated the formation of SiC coating layers on the graphite. The microstructural,mechanical, and thermal oxidation properties of the coated graphite were investigated.

Association Among Self-Injury, Suicidal Tendency, and Personality and Psychological Characteristics in Korean Adolescents

Kyojin Yang,Si Young Kim,Hyejin Kim,Jun-Won Hwang 대한신경정신의학회 2022 PSYCHIATRY INVESTIGATION Vol.19 No.1

Objective To compare mental health problems and personality characteristics between adolescents with self-injury (SI) and suicidal tendency (ST), including suicidal ideation and suicide planning. Methods The participants completed the Adolescent Personality and Mental Health Problems Screening Questionnaire, Third version (AMPQ-III), and Korean version of the Strengths and Difficulties Questionnaire (SDQ-Kr), and gave their demographic information. Based on the answered SI and ST items in AMPQ-III, the participants were divided into groups: without SI and ST, with SI and without ST, without SI and with ST, and with SI and ST. Analysis of variance (ANOVA) and post-hoc Scheffe test were used to determine group differences, stepwise multiple linear regression, and factors associated with SI and ST. Results ANOVA yielded results for all categories of mental health problems. Significant differences were observed between the four groups. Conversely, for personality characteristics, only the sense of community item between the group without SI and with ST and the group without SI and ST were significantly different; sense of community was associated with ST (β=-0.054, p=0.005). Among the mental health subscales, SI was significantly associated with conduct problems (β=0.211, p<0.001), emotional problems (β=0.173, p<0.001), peer problems (β=0.085, p<0.001), and prosocial behavior (β=0.073, p<0.001). ST was significantly associated with emotional symptoms (β=0.317, p<0.001), peer problems (β=0.130, p<0.001), conduct problems (β=0.106, p<0.001), hyperactivity (β=0.050, p=0.010), and prosocial behavior (β=0.062, p<0.001). Conclusion The findings highlight the necessity of assessing psychological strength, difficulties, and personality characteristics for the prevention and early intervention of adolescent SI.

아조염료의 전기분해에 대한 반응파라미터의 측정

황영기,방시욱 慶南大學校 附設 工業技術硏究所 1998 硏究論文集 Vol.15 No.3

Carmine-6B 아조염료 수용약을 양극산화시키는 전기분해반응에서 부반응이 없는 최소운전전압은 1.2V로, 산소발생에 따른 부가적인 산화작용을 고려한 최적운전전압은 20∼25V로 각각 조사되었다. 초기속도법으로 구한 분해반응치수는 0.68로 측정되었으며 반응속도는 전압상승에 따라 0.5승에 비례하였다. 물질전달계수는 pH에 무관하고 교반속도의 ⅓승에 비례 증가하였다. Decomposition of Carmine-6B azo dye has been performed by electrochemical oxidation. Minimum voltage for the reaction was found to be 1.2V. Oxygen evoluted on anode effected on the decomposition at the cell voltage as high as 20V or 25V. Initial reaction rate depended on both initial concentration with 0.68th order and cell voltage with 0.5th order. Mass transfer coefficient of azo dye was independent on pH of solution, but it was in proportion to its agitating speed by one third power .

일본잎갈나무 낙엽의 추출성분 및 항산화활성

사전령,권동주,김진규,황병호,배영수 江原大學校 森林科學硏究所 2005 Journal of Forest Science Vol.21 No.-

일본잎갈나무 낙엽 (8.5kg)을 채취하여 9.5% EtOH 용액으로 추출하고 농축된 추출용액은 분획깔때기로 헥산, 메틸렌클로라이드, 에틸아세테이트 및 수용성으로 순차 추출하여 동결건조하였다. 에틸아세테이트용성과 수용성 분획에 대하여 칼럼크로마트크래피를 실시하였고, 충진물질로는 Sephadex LH-20을, 용리용매로는 메탄올 수용액 및 에탈올-핵산 혼합용액을 사용하였다. 단리된 화합물들은 TLC로 확인한 후 NMR 스펙트럼을 사용하여 정확한 구조규명을 하였고 FAB-MS와 EI-MS 스펙트럼으로 분자량을 측정하였다. 일본잎갈나무 낙엽으로부터 5개의 화합물을 단리하였으며, 각 분획물과 단리된 화합물들은 DPPH 라디칼 소거법을 이용하여 항산화 시험을 실시하였다. Fallen neeldes (8.5kg) of Larix kaempferi were separately collected. extracted with 95% EtOH. EtOH extract was evaporated under reduced pressure, concentrated then successively fractionated with a series of hexane. methylene chloride, ethylaectate and water on a separatory funnel. Then, each fraction was freeze dried. A portion of ethylacetate and water soluble powder were packed on a column chromatography (Sephadex LH-20) eluting with aqueous MeOH and EtOH-hexane mixture. Spectrometric analyses such as NMR and FAB-MS including TLC were performed to characterize the structures of isolated compounds.

반코마이신 골시멘트의 유효성 및 안정성에 대한 고찰

황시영,김은영 충남대학교 약학대학 의약품개발연구소 2012 藥學論文集 Vol.27 No.-

Infections of prosthetic joints represent a major cause of morbidity from both the loss of mobility. Vancomycin impregnated cement is used as a spacer or during reimplantation surgery for the treatment of prosthetic joint infection. The aim for this article is to evaluate the effectiveness and safety for preclusive use of vancomycin to prosthetic joint. PubMed and EMBASE search was conducted using a combination sear ch term "vancomycin" as MeSH terms, "cement" as All Fields, and "infection" as All Fields. 9 out of 40 papers which were searched were used to reviewing. Effectiveness- although results of randomized, controlled trials were insufficient, the result shows that vancomycin-impregnated cement takes advantage of prevention and control of infection and maintenance of joint function. Safety- in some cases, nephrotoxicity was reported when vancomycin-impregnated cement was inserted. But still in needs more well designed RCTs and supportive guidelines. Although the use of vancomycin with impregnated cement is not approved by KFDA, it was effective and safe for the treatment of prosthetic joint infection based on this review.

경관 Simulation을 통한 수영강 연접지역의 건축물 고도규제 방안

윤시운,이광국,황영우 東亞大學校 建設技術硏究所 1999 硏究論文集 Vol.23 No.1

This study analyzes the future landscape assesment of Suyoung-River and adjacent areas. Computer Simulation method is used for these purposes. It is expected that the high buildings and high density in Suyoung Information Site might cover the Jang-Mountain view. Therefore this study analyzes the expectations by the experiment of the change of the heights of buildings and the view-point so that Suyoung Information Site can secure the feelings of openness and can be harmonious with natural landscape and skyline. If the high dense buildings are going to be constructed, the optimum condition of development should be between 1.5 and 2.0 of evaluation indicator. The minimum indicator 1.5 would be appropriate as the standard of regulation. The results show that the buildings along the riverside road in the west need to be regulated under the height of 30m(about 10 stories) and the buildings along the Chungryul-Street in the east under the height of 90m(about 30 stories). 하천은 산과 구릉지 등과 함께 도시의 아름다운 경관을 형성하는 중요한 경관요소이다. 도시내 하천변에 나타나는 경관문제는 대부분 대규모 건축물에 의한 경관 훼손에서 비롯된다. 부산의 대부분 하천은 시가지를 통하여 바다로 유입되고 있으나 대부분 복개되었거나 주변지역의 고층건물 입지로 인해 하천 자체가 시민에게 주는 정 (正)의 경관적 요소는 점점 감소하고 있다. 본 연구의 대상지인 수영강은 현재 시가지내를 흐르고 있어 시민에게 주요한 openspace로 기능하고 있다. 주변지역은 지금까지 수영 비행장이라는 기능으로 연해 개발이 유보되어 오다 최근 수영정보단지의 개발계획 등으로 인해 개발압력을 강하게 받고 있다. 향후개발이 진행된다면 수영강변에서 조망할 수있는 주변 자연경관과 시가지 경관은 차폐될 뿐만 아니라, 그 자체의 규모가 크고 형태도 단조로와 위압적이고 획일적인 경관이 형성되게 될 것이다. 현재에도 수영강변의 구릉지에는 아파트 가 입지하여 조망을 차폐하고 있을 뿐 아니라 녹지를 잠식하고 있다. 이러한 현상은 향후 개발압력에 빌려 수영강변의 어느 지역 에서나 발생하는 공통적인 현상이 될 것이다. 이러한 조망차폐, 획일성, 위압감의 조성, 지형의 훼손 및 잠식 등으로 대표되는 수영강의 경관문제는 현행법상 건축심의 시 받는 경관심의로 해결하기에는 한계가 있다. 따라서 본 연구는 수영강과 연접지역, 그리고 배경녹지축인 주변산을 공간적 범위로 하여 첫째, 수영강 연접지역의 범위를 설정하고 연접지역을 몇 개의 경관구역으로 나누어 각 경관구역별 경관의 문제점과 특성을 살펴본다. 둘째, 경관분석을 위하여 Computer를 이용한 수영강변 주요 조망점 에서 사람의 눈에 보이는 대로 주변 경관을 연출해 낼 수 있는 가상의 경관 Simulation을 실시한다. 셋째,이를 바탕으로 수영강 연접지역의 건축물 고도규제 를 위한 기준설정과 고도규제 방안을 제안하는데 목적이 있다.

급성신부전을 동반한 알콜성 횡문근융해증 2례

김영민,오동렬,이원재,김형국,황두영,이환,최경호,정시경,김세경,김영옥 大韓應急醫學會 1998 대한응급의학회지 Vol.9 No.4

Rhabdomyolysis is a biochemical and clinical syndrome caused by lysis of skeletal muscle cell and release of muscle cell contents into the circulation. In addition to traumatic cause, various nontraumatic causes have been reported. Rhabdomyolysis has frequently been associated with seamy aspects of life and society: alcoholic abuse, drug addiction, sadistic drill exercise, war events and attempted suicide. The abuse of alcohol causes many hazards in many organs. One of these is acute alcoholic myopathy that may present as a fulminent syndrome of muscle pain and tenderness associated with rhabdomyolysis and acute renal failure. Because the prognosis of adequately treated rhabdomyolysis is excellent, early recognition and prompt management are essential in emergency situation. We experienced two typical cases of alcohol-induced rhabdomyolysis with acute renal failure and report these cases with literature review.

선박용 폐 FRP 수지의 재활용 공정 개발

강세란,김영우,황덕기,김시영,이민규,주창식 한국환경과학회 2003 한국환경과학회지 Vol.12 No.6

A recycling process for the waste FRP from boats was developed. The recycling process is composed of decomposition of waste FRP with propylene glycol and synthesis of recycled unsaturated polyester resin from the decomposed liquid material. Prior to the decomposition, waste FRP was cut into 2cm × 5cm segments and mechanical impact was applied by press roller to give gaps between cumulated laminates. Propylene glycol effectively decomposed the waste FRP segments and glass fibers were easily separated from decomposed liquid material. Recycled unsaturated polyester resin could be made from the decomposed liquid material by reaction with maleic anhydride and phthalic anhydride.

응급센터에서 기관내 삽관을 시행하지 않은 호흡곤란 환자의 동맥혈 이산화탄소분압과 호기말 이산화탄소분압의 연관성분석

김형국,박승현,오동렬,박규남,이원재,황두영,최승필,이운정,정시경,김세경 大韓應急醫學會 1998 대한응급의학회지 Vol.9 No.4

Background: The end-tidal carbon dioxide tension(ETCO₂) is defined as a partial pressure of carbon dioxide at the end of an exhaled breath. The purpose of this study is to determine the correlation between ETCO₂and arterial carbon dioxide tension(PaO₂) in nonintubated patients with respiratory distress in emergency department(ED). Methods: A prospective non-blind study was performed in ED of our university hospitals. Participants included all nonintubated adult patients with respiratory distress requiring arterial blood gas analysis. ETCO₂was measured with a capnography monitor during tidal volume breathing. ETCO₂were recoreded at the time of arterial blood gas sampling. The correlation between ETCO₂and PaCO₂was analyzed in all patients and in subgroups by simple linear regression. Results: Sixty patients were enrolled. In all patients, ETCO₂was 5.72mmHg lower than PaCO₂and correlated well with PaCO₂(r²=0.716). ETCO₂correlated best with PaCO₂in patients who were either acidotic or non-smoking. Conclusion: ETCO₂correlate well with PaCO₂in nonintubated patients with respiratory distress in ED. ETCO₂may be sufficient to reflect PaCO₂in selected patients and obviate the need for repeat arterial blood gas determination.

백서 척수후근절로부터 슈반세포의 효과적인 체외 배양법

김성민,이종호,김남열,안강민,최원재,최시호,차미주,이주영,황순정,장정원,명훈,최진영,서병무,정필훈,김명진 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.4

Schwann cells(SCs), an important component of the peripheral nervous system, intract with nerous to mutually support growth and replication for the peripheral nerve regentation. Recently, ading SCs to the lumen of guidance channel is widely tried to improve regeneration or to make regeneration possible over otherwise irreparable gaps. however, it is not easy to isolate and multiplicate SCs as much as enough to help the axonal regeneration. For the allogeneic SCs source for tubular nerve guidance, we developed a little bit improved technique of harvesting and multiplicating SCs. by culturing dispersed dorsal root ganglia in specially designed medium with growth factors and serial processing, we repeatedlly generate relatively homogenous SC cultures. Our technique was compared with other methods of literature using immunostaining methods such as GFAP, S100, BDNF and the total SC count assessment at different time interval after primary culture.