초음파 진동이 가진된 밀폐용기에서 상변화 열전달 특성

박설현,정대훈,오율권 조선대학교 에너지.자원신기술연구소 2001 에너지·자원신기술연구소 논문지 Vol.23 No.1

Solid-liquid phase change (i.e. melting or solidification) occurs in a number of situations of practical interest. Some common examples include the melting of edible oil. metallurgical process such as casting and welding, and materials science applications such as crystal growth. Therefore, due to the practical importance of the subject, there have been a large number of experimental and numerical studies of problems involving phase change during the past few decades. This study presents experimental work on phase change heat transfer. Especially, in order to increase heat transfer rate. ultrasonic vibrations were introduced. The melting cavity contained one vertical heating surface which dissipates heat at constant power and was insulated on the sides. Experimental observations show that the effect of ultrasonic vibrations on heat transfer is very important throughout melting process. The results of this study reveal that ultrasonic vibrations accompany the effects like agitation, acoustic streaming, cavitation, and oscillating fluid motion. Such effects are a prime mechanism in the overall melting process when ultrasonic vibrations are applied. They speed up the melting process as much as 2.5 times, compared with the result of natural melting. Also, energy can be saved by applying ultrasonic vibrations to the natural melting.

배관내에서 난류 마찰 저항감소에 관한 연구

박설현,윤정환,서동표,정대훈,오율권 朝鮮大學校 機械技術硏究所 2000 機械技術硏究 Vol.3 No.1

Polymer drag reduction can offer a attractive way to utilize ready-made facilities in crude-oil transport system without additional large expenditure. Also, drag reduction in two phase flow can be applied to phase change system such as chemical reactor, pool and pump impeller which occurs cavitation. But the research on drag reduction in two phase flow has not been investigated. Therefore, experimental investigations have been carried out to analyze the drag reduction in the single phase and two phase flow. The objectives of the proposed investigation are primarily to identify and develop high performance polymer additives for fluid transportation. And drag reduction will be evaluated in horizontal flow by measuring void fraction, pressure drop, mean liquid velocity and turbulent intensity

가스가 주입된 용기에서 기공율, 기포빈도와 온도측정에 관한 연구

박설현,오율권,서동표 朝鮮大學校 機械技術硏究所 1999 機械技術硏究 Vol.2 No.2

The local phase volume fraction, bubble frequency and the phase temperature distributions were measured in vertical air injected water baths. An electroresistivity probe was employed for the determination of the local void fraction and bubble arrival frequency. The phase resolved temperatures were measured using a microthermocouple. The thermocouple signals were digitally filtered, and were carried out to characterize the overall structure of the gas-liquid plume and the heat transfer mechanism between the phases.

문수산(봉화군) 일대의 식물상

한종원, 양선규, 최슬기, 장창석, 김규식, 오병운 忠北大學校部設基礎科學硏究所 2007 自然科學硏究 Vol.21 No.-

-본문참고-

장군봉(봉화군) 일대의 식물상

한종원, 양선규, 최슬기, 장창석, 김규식, 오병운 忠北大學校部設基礎科學硏究所 2007 自然科學硏究 Vol.21 No.-

-본문참고-

백두대간(추풍령-덕유산)구간의 식물상

한종원, 양선규, 최슬기, 장창석, 오병운 忠北大學校部設基礎科學硏究所 2007 自然科學硏究 Vol.21 No.-

-본문참고-

초등학교 고학년 학생의 장애아동에 대한 인식 조사

김보람,김호영,손유라,오진주,윤슬기,이효정,장문영 대한감각통합치료학회 2011 대한감각통합치료학회지 Vol.9 No.1

목적 : 초등학교 고학년 학생의 장애아동에 대한 인식을 알아보는 것이다. 연구방법 : 연구 대상은 김해시에 소재한 통합교육을 실시하지 않는 초등학교의 4, 5, 6학년의 비장애 아동이었다. 연구 기간은 2008년 10월 2일부터 10월 17일까지였으며, 설문지를 사용하였다. 설문지의 하위 영역은 사귐, 활 동, 학업 영역의 세 부분으로 각 10문항으로 이루어져 있으며 SPSS 12.0을 사용하여 분석하였다. 결과 : 장애아동에 대한 인식조사 결과 첫째, 성별에 따른 인식은 남학생보다 여학생의 평균 점수가 높았으나 통계 적으로 유의미한 차이는 없었다. 둘째, 학년에 따른 인식은 4학년의 평균 점수가 가장 높았고 6학년이 가장 낮았으 며 통계적으로 유의미한 차이가 있었다(F=3.546, p<0.05). 셋째, 장애인 접촉 유무에 따른 인식은 접촉 경험이 없 는 학생이 있는 학생보다 평균점수가 높았으나 통계적으로 유의미한 차이는 없었다. 결론 : 비장애학생의 장애아동에 대한 인식은 학년에 따라 차이가 있었다. 본 연구는 작업치료사들에게 장애아동에 대한 또래집단의 인식에 대한 정보를 제공함으로써 학교환경에 대한 이해를 도울 수 있을 것이다. Objective : The purpose of this study was to investigate attitude of grade-schoolers toward children with disabilities. Methods : The subjects of this study were grade-schoolers who have not received an inclusive education in Gim-hae. The study was surveyed from October second to 17th in 2008. The survey was categorized into three parts; comradeship, activity, and study. Each part of the survey consists of 10 questions. Data were analyzed by SPSS (version 12.0). Results : The results were as follows; First, the attitude of girls toward disabled students was non-significant compared to boys. Second, the order of attitude degree in grade of students was 4, 6, and 5. The attitude toward children with disabilities showed statistically significant difference according to grade(F=3.546, p<0.05). Third, the attitude of students who have experience of contact with people with disabilities was non-significant compared to non-experienced students. Conclusion : In conclusion, therefore peer groups in lower class levels showed more positive attitude toward the children with disabilities. The result will be useful information for understanding disabled children and making positive attitude. Also it is expected that occupational therapists help disabled children to participate in school life successfully using these information.

Biotransformation of Linoleic Acid into Hydroxy Fatty Acids and Carboxylic Acids Using a Linoleate Double Bond Hydratase as Key Enzyme

Oh, Hye‐,Jin,Kim, Sae‐,Um,Song, Ji‐,Won,Lee, Jung‐,Hoo,Kang, Woo‐,Ri,Jo, Ye‐,Seul,Kim, Kyoung‐,Rok,Bornscheuer, Uwe T.,Oh, Deok‐,Kun,Park, Jin‐,By WILEY-VCH 2015 Advanced Synthesis & Catalysis Vol. No.

<P><B>Abstract</B></P><P>Hydroxy fatty acids are used as starting materials for the production of secondary metabolites and signalling molecules as well as in the manufacture of industrial fine chemicals. However, these compounds are usually difficult to produce from renewable biomass by chemical means. In this study, linoleate double bond hydratases of <I>Lactobacillus acidophilus</I> NBRC 13951 were cloned for the first time. These enzymes were highly specific for the hydration of the C‐9 or the C‐12 double bond of unsaturated fatty acids (e.g., linoleic acid). Thereby, the enzymes allowed the selective production of hydroxy fatty acids such as 13‐hydroxy‐<I>cis</I>‐9‐octadecenoic acid and 10‐hydroxy‐<I>cis</I>‐12‐octadecenoic acid from linoleic acid. In addition, the hydroxy fatty acids were further converted into industrially relevant carboxylic acids (e.g., 12‐hydroxy‐<I>cis</I>‐9‐dodecenoic acid, α,ω‐tridec‐9‐enedioic acid) and lactones (i.e., δ‐decalactone, γ‐dodecelactone) <I>via</I> whole‐cell biocatalysis using an enzyme cascade. This study thus contributes to the preparation of hydroxy fatty acids, unsaturated carboxylic acids, and lactones from renewable unsaturated fatty acids.</P>

Prevalence and Factors of Chronic Kidney Disease

( Seul Hyun Oh ),( Ha Yeon Kim ),( Chan Young Oak ),( Min Jee Kim ),( Chang Seong Kim ),( Joon Seok Choi ),( Hyung Chul Lee ),( Jeong Woo Park ),( Eun Hui Bae ),( Seong Kwon Ma ),( Nam Ho Kim ),( Soo 대한신장학회 2010 Kidney Research and Clinical Practice Vol.29 No.4

Purpose: The prevalence of chronic kidney disease (CKD) is increasing. Accordingly, hospitalization and mortalities associated with CKD also have increased. The present study aimed to determine the prevalence of CKD, and explore the causative risk factors. Methods: One thousand one hundred and forty-seven patients who underwent the mass health screening test at Chonnam National University Hospital between July 2007 and December 2007 were studied. The prevalence of CKD and possible risk factors such as gender, previous history of diabetes mellitus and hypertension, smoker status (current and ex-smoker), BMI, increased LDL cholesterol, triglyceride levels, HDL cholesterol level and anemia were analyzed. Results: There were 631 male and 616 female subjects. Mean age was 48.6 years and mean glomerular filtration rate was 117.2±28.7 ml/min/1.73m(2). The prevalence of CKD was 10.3%, and the prevalence of advanced CKD (CKD stage 3-5) was 0.5%. The prevalence of advanced CKD was higher in subjects with diabetes. The awareness of CKD was very low. Factors independently associated with CKD were sex favoring men (odd ratio [OR], 2.106; 95% CI, 1.436-3.090), smoker (OR, 0.575; 95% CI, 0.382-0.867), DM (OR, 2.395; 95% CI, 1.338-4.286), inadequate blood sugar (OR, 2.536; 95% CI, 1.267-5.077), HDL<40 mg/dL (OR, 0.418; 95% CI, 0.191-0.915) in a univariate analysis. With a multivariate analysis, female gender (OR, 2.123; 95% CI, 1.209-3.730) was the only independent risk factor for CKD. Conclusion: Since the CKD is a public health burden, closer attention is needed to prevent the CKD in the high-risk group.

Necrosectomy of hepatic left lateral section after blunt abdominal trauma in a patient who underwent central hepatectomy and bile duct resection for perihilar cholangiocarcinoma

Seul Gi Oh,Shin Hwang,Suhyeon Ha,Heewon Kim,Lee Na Ryu 한국간담췌외과학회 2020 Annals of hepato-biliary-pancreatic surgery Vol.24 No.3

When the liver is divided into the right and left halves after central hepatectomy, a serious injury to the one half of the liver can destroy the ipsilateral half. We report a case showing total necrosis of the hepatic left lateral section (LLS) caused by blunt abdominal trauma in a patient who had undergone central hepatectomy and bile duct resection for perihilar cholangiocarcinoma. A 47-year-old female patient was transferred because of postoperative status following blunt abdominal trauma. Five years before, she had been diagnosed with perihilar cholangiocarcinoma. Since the tumor extent was compatible with Bismuth-Corlette type IV, she underwent central hepatectomy and bile duct resection. After five years, she experienced an industrial safety accident, in which a heavy refrigerator fell over her body. She underwent emergency duodenal diversion surgery with distal gastrectomy and Roux-en-Y gastrojejunostomy. During this surgery, serious ischemic injury of the LLS with occlusion of the left portal vein and hepatic artery was identified, but not treated. After three weeks, LLS necrosectomy with repair of the jejunal limb was done. Postoperative bile leak developed and required supportive care for two months for its healing. She is currently doing well without any physical discomfort four months after the necrosectomy. Our experience with this case suggests that an injury to the afferent jejunal limb requires an individualized treatment strategy including long-standing waiting with effective drainage for spontaneous healing. The experience of this case appears to be theoretically matched with late-stage resection of LLS following central hepatectomy and bile duct resection.