유화처리 바이오디젤이 도포된 콘크리트의 침투깊이 판정

백철 ( Baek Cheol ),김태우 ( Kim Tae-woo ),이재진 ( Lee Jae-jin ),이동윤 ( Lee Dong-yun ),한민철 ( Han Min-cheol ),한천구 ( Han Cheon-goo ) 한국건축시공학회 2017 한국건축시공학회 학술발표대회 논문집 Vol.17 No.2

This study is to provide a evaluation method for the penetration depth of emulsified refined bio diesel(ERBD)applied to a surface of the concrete by using water absorption capability of the concrete. The concrete applied with ERBD was immersed at water for 1 min., 5min., and 10 min. and then was checked the brightness with elapse of time. Test results indicated that there was clear difference between ERBD part and non ERBD part in concrete specimen after measuring the brightness until 120min.

대장내시경검사의 전처치로서 항콜린제 사용에 관한 연구 : 전향적, 이중맹검법으로

박경남,한동수,이민호,최호순,박준용,손주현,이오영,함준수,전용철,송승찬,기춘석,윤병철,이종희 대한소화기내시경학회 1997 Clinical Endoscopy Vol.17 No.3

Background: Use of antispasmodic medication prior to colonoscopy is controversial but someone believes antispasmodic may improve visualization of colonic mucosa and ease colonoscope insertion. So, we designed a study to assess the effect of premedication with the antispasmodic, hyoscine-N-butyl bromide(Buscopan') on the performance of colonoscopy. Methods: This study was prospective, double blinded, randomized, controlled study, One hundred three consecutive patients were randomized to receive intravenous buscopan lml(n=52) or placebo(n=51) combined with our standard initial medication(me- peridine 50 mg and midazolam 2 mg). Insertion of colonoscopy was timed, and 100 mm visual analogue scales (VAS) were used for asscssing difficulty of procedure, colonic motility, frequency of positional change, frequency of external compression, difficulty of assistance and degree of discomfort experienced by the patients. Results: There were no significant differences of intubation time between buscopan group(mean time, 7.23 min., range 2~15) and placebo group(7.07 min., range 3-25), (p=0.83) and withdrawal time between buscopan group (6.46 min., range 2-22) and placebo group(6.76 min., range 2 25), (p=0.69). Also, there was no significant differences in intubation time between males and females(buscopan; males 7.00 min., females 7.60 min., p=0.34, placebo; males 7.0~5 min., females 7.08 min., p 0.44). The VAS scores checked by endoscopist(p=0.29), assistant(p=0.32) and patient (p=0.15) were not significantly different in both groups. There were no significant differences in intubation time, VAS scores nf endoscopist, assistant, and patients. Conclusion: Premedication with intravenous bu.opan has no advantage on colonoscopy procedure. Use of antispasmodic medication prior to colonoscopy was not considered as recommendable agent.

The effects of secondary task on the control of vehicle under driving simulator: a study among 50s taxi drivers

Han Soo Kim,Jin Seung Choi,Dong Won Kang,Hong Won Yeon,Mi Hyun Choi,Doo Hwan Ji,Byung Chan Min,Soon Cheol Chung,Gye Rae Tack 대한인간공학회 2011 대한인간공학회 학술대회논문집 Vol.2011 No.5

Objective: The aim of this study is to quantitatively evaluate the effects of the secondary task during simulated driving using the variable indicating control of vehicle. Background: There are so many researches for simulated driving and performance. For instance, some researches show that the effects of cell phone conversations on simulated driving. Cell phone conversations impaired explicit recognition memory. Method: Participants included 50s taxi drivers; 15 males and 15 females. All subjects were instructed to keep a distance (30m) from the car ahead and a constant speed (80km/hr or 100km/hr). Sending text message (STM) and Searching navigation (SN) were selected as the secondary task. Experiment consisted of rest for 3min., driving alone for 1min. and driving with secondary task for 1 min.. We were analyzed anterior-posterior coefficient of variation (APCV) and medial-lateral coefficient of variation (MLCV). Results: APCV was increased by 175.4% in STM and 223.8% in SN at 80km/hr. MLCV was increased by 242.3% in STM and 323.4% in SN at 100km/hr. There was no significant difference between genders. Conclusion: Consequently, performing secondary task during driving impaired the control of vehicle.

미더덕의 생리활성이 향상된 아임계수 추출물의 제조

조민지(Min-Ji Jo),한지경(Ji-Kyoung Han),성수창(Su-Chang Sung),이승철(Seung-Cheol Lee) 한국식품영양과학회 2018 한국식품영양과학회지 Vol.47 No.11

미더덕의 이용 다변화를 위하여 아임계수 추출물을 제조하고 생리활성을 평가하였다. 미더덕은 동결건조 분말 상태로 10, 30, 60분 동안 다양한 온도(50, 100, 200, 300℃)에서 추출되었다. 아임계수 조건은 ACE 저해 활성, 항산화 활성, AChE 저해 활성과 같은 중요한 생리학적 특성을 상당히 증가시켰다. 200℃, 60분 추출물에서 가장 높은 ACE 저해활성을 나타냈으나 더 높은 온도 조건인 300℃에서는 급격히 감소하였다. DPPH 라디칼 소거능과 ABTS라디칼 소거능은 300℃, 30분 추출물에서 공통적으로 가장 높은 값을 보였고, AChE 저해 활성 또한 같은 경향을 나타냈다. 이러한 결과는 아임계수 추출이 미더덕의 생리활성을 증가시키는 유용한 가공방법이 될 수 있음을 시사한다. For diverse application of Styela clava (Korean name: miduduck) as a food material, subcritical water (SCW) extract was prepared and its physiological activity was evaluated. To accomplish this, S. clava powder (0.1 g) was placed in a stainless vessel containing 10 mL of distilled water, after which SCW extraction was carried out at 50, 100, 200, and 300℃ for 10, 30, and 60 min. SCW treatment significantly increased important physiological properties of the extract such as angiotensin converting enzyme (ACE) inhibitory activity, antioxidant activity, and acetylcholinesterase (AChE) inhibitory activity. The highest ACE inhibitory activity was found in samples subjected to SCW extraction at 200℃ for 60 min; however, the activity decreased at higher temperature (300℃). The SCW extract of S. clava prepared at 300℃ for 30 min showed the highest antioxidant activity [1,1-diphenyl-2-picrylhydrazyl and 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activities] and AChE inhibitory activity. These results indicate that SCW extraction might be a useful method for increasing the physiological activity of S. clava.

단신 : 실리콘의 염소화반응에 의한 사염화규소 제조

박균영 ( Kyun Young Park ),이미선 ( Mi Sun Lee ),김민철 ( Min Cheol Kim ),이찬희 ( Chan Hee Lee ),박회경 ( Hoey Kyung Park ),강태원 ( Tae Won Kang ),정해성 ( Hae Seong Jeong ),한경아 ( Kyoung Ah Han ),허원회 ( Weon Hoe Huh ),유지 한국화학공학회 2013 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.51 No.3

직경 25 mm의 파이렉스 튜브 내에서 실리콘의 유동층 염소화 반응이 수행되었다. 반응기에 공급되는 질소 유량0.8~1.0 L/min, 염소 유량 0.2 L/min, 반응온도 450℃, SiCl4 응축기의 냉매온도는 -5℃로 설정하였다. 반응기에 도입되는 가스 내 염소의 몰분율이 증가하면 SiCl4의 수율이 증가하였다. 반응가스 중 염소의 몰분율 0.2의 조건에서 SiCl4의 수율은 28% 이었다. 염소의 몰분율 증가는 반응열 상승에 의해 반응온도 상승을 가져옴으로써 안전을 고려하여 염소의 몰분율을 0.2 이상으로 올리지 못했다. 실리콘의 유동층 염소화 반응에 의한 사염화실리콘의 제조 가능성이 입증되 었으며, 향후 보다 가혹한 조건에서의 실용화 연구를 위한 기초로 활용될 수 있을 것으로 기대된다. The chlorination of a metallurgical-grade silicon was carried out in a fluidized bed reactor, 25 mm in diameter. The flow rate of the chlorine admitted into the reactor was 0.2 L/min and that of the carrier nitrogen was 0.8~1.0 L/ min. The reactor temperature was maintained at 450℃ and the temperature of the coolant at the SiCl4 condenser was at -5℃. The SiCl4 yield increased with increasing the mole fraction of chlorine in the feed gas, exhibiting 28% at the mole fraction of 0.2. Further increase of the chlorine mole fraction was not attempted in a worry that the reactor might be failed due to the high exothermicity of the reaction. The production of SiCl4 from silicon by fluidized bed chlorination was demonstrated on a laboratory scale, which is a stepping stone for future studies under more severe conditions toward industrial application.

고온양생이 콘크리트의 강도발현에 미치는 영향

한민철 청주대학교 산업과학연구소 2007 産業科學硏究 Vol.24 No.2

In this paper, estimation of compressive strength of concrete subjected to high temperature was discussed. Water to binder ratios ranging from 30% to 60% and curing temperature ranging from 20℃∼65℃ were adopted for experimental parameters. According to results, high curing temperature resulted in an increase in early age strength, while it led to decrease later age strength. for strength estimation, Logistic model based on maturity equation and Carino model based on equivaltlt age were applied to verify the availability of estimation model. It shows that fair agreements betwetl calculated values and measured values were obtained evaluating compressive strength with logistic curve. The application of logistic model at high temperature had remarkable deviations at later maturity. Whereas, the application of Carino model showed good agreements between calculated values and measured ones regardless of W/B. However, correction factors should be considered to enhance the accuracy of later age strength estimation of concrete for both Logistic and Carino model.

Stearic Acid로 被覆한 Fe₃O₄에 의한 油分除去 (Ⅰ)

韓尙敏,張哲鉉,朴勝祚 동아대학교 환경문제연구소 1989 硏究報告 Vol.12 No.1

The large quantity of iron contained in waste sludge discharged form pickling liquor in a steel industry was used for Fe₃O₄. Then we new adsorbent for oil removal was made. The adsorbent was made of Fe₃O₄ coated with stearic acid. The results of this study that perform batch test to relate adsorptive ability, and oil removal efficiency of the adsorbent with kerosene, bunker-c oil, and emulsified bunker-c oil are followings : 1) The results of batch adsorption test fit well to the Freundlich equation, and the K of kerosene, bunker-c oil, and emulsified bunker-c oil was, 0.20, 0.17, and 0.16, respectively. 2) The adsorptive reaction was the first order reaction and the K' was 0.526/min. 3) The kerosene removal efficiency by new adsorbent was 30% in the alkalinity, 85% in the acidity and 92% in a neutrality.

A chemically regenerative redox fuel cell using (2,2,6,6-tetramethylpiperidin-1-yl)oxyl redox reaction in acid medium

Han, Sang-Beom,Kwak, Da-Hee,Park, Hyun Suk,Park, Jin-Young,Ma, Kyeng-Bae,Won, Ji-Eun,Kim, Do-Hyoung,Kim, Min-Cheol,Park, Kyung-Won Elsevier 2018 Journal of Power Sources Vol.393 No.-

<P><B>Abstract</B></P> <P>(2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO) with no free radical and non-volatile characteristic can be utilized as a liquid catalyst instead of O<SUB>2</SUB> at the cathode in a chemical regenerative redox fuel cell with H<SUB>2</SUB> as a fuel at the anode. In this study, the electrochemical properties and performance of TEMPO dissolved in sulfuric acid solution are investigated using half and unit cells. In the half-cell, TEMPO shows an activation energy of 1.27 kcal mol<SUP>−1</SUP> K<SUP>−1</SUP> for the reduction. A chemical regenerative redox fuel cell (CRRFC) using TEMPO as the liquid catalyst exhibits an open circuit voltage of 0.7 V and a maximum power density of 90 mW cm<SUP>−2</SUP> at 30 °C with a low activation loss. The regeneration cycling test of the CRRFC is performed at a constant voltage of 0.4 V under a flow rate of the oxygen-bubbled TEMPO solution. The performance of the CRRFC deteriorates, i.e., a power density of zero measured at >200 min. Thus, a highly efficient regeneration system needs to be developed for a high-performance CRRFC using TEMPO used as a liquid-type oxidant. Furthermore, stable liquid oxidants with relatively high standard reduction potentials can be proposed through various organic compounds.</P> <P><B>Highlights</B></P> <P> <UL> <LI> CRRFC was proposed using TEMPO instead of O<SUB>2</SUB> at the cathode. </LI> <LI> TEMPO showed fairly fast transport and low activation energy for the reduction. </LI> <LI> CRRFC exhibited an open circuit voltage of ∼0.7 V at 30 °C. </LI> <LI> CRRFC exhibited a maximum power density of ∼90 mW cm<SUP>−2</SUP> at 30 °C. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

조강성 혼화제 종류에 따른 콘크리트의 물리적 특성

한천구,한민철,노상균 청주대학교 산업과학연구소 2009 産業科學硏究 Vol.26 No.2

The purpose of this study is to compare and analyze the physical properties of concrete in connection with the recent trends to reduce construction periods, in order to increase early-strength of the concrete where the various kinds of liquified early strength concrete agent are used. As for the experiment plan in two levels such as the W/C 30, 50 %, which the standard air entraining water reducing agent(The following P) was intermixed as the plain, the early-strength agent of MAS serial(The following A), the AE reducing agent of early-strength type of the polycarbonic acid serial(The following B) and the naphthalene+lignin serial(The following C) were selected to change them into 4 levels, so that total 8 levels might be included in the experiment. According to the results, the setting time accelerated as the B was fastest and followed by A and C. And as for the compressive strength, the strength development of A recorded 115 %, B recorded 95% and C recorded 80 % of the plain mixture respectively when they were compared with the plain mixture at one day of age, but in the case of 3 days of age, a recorded 103 %, B recorded 104 % and C recorded 110 % of the plain mixture respectively. On the other hand, when A was added the air content increased by 2 %, so it is judged that the compressive strength of A would more than by 10% in consideration of the fact that the compressive strength fell off by 4~6 % when the air content increased by 1 %.

신우신염으로 오인된 부종양증후군을 동반한 신세포암

한민철,김재헌,박성재,변동원,강덕희,심봉석 이화여자대학교 의과대학 2004 EMJ (Ewha medical journal) Vol.27 No.2

Renal cell carcinoma can presents wide range of signs and symptoms, and commonly associated with paraneoplastic syndrome. Paraneoplastic manifestations are present in up to 20% of patients with renal cell carcinoma. There is convincing evidence that renal cell carcinoma tumor cells elaborate proteins that serve as mediators of endocrine (ex ; ectopic production of parathyroid hormone-related protein or erythropoietin) as well as nonendocrine paraneoplastic syndromes. A paraneoplastic syndrome may be the various clinical presentation of renal cell carcinoma in a significant number of patients, therefore mimicked other general disease. We report a case of renal cell carcinoma associated with paraneoplastic syndrome mimicking pyelonephritis.