액적의 Weber 수에 따른 냉각특성의 변화

방창훈,양창호 한국산업안전학회 2003 한국안전학회지 Vol.18 No.1

The objective of the present work is to examine the variation of cooling characteristics due to the Weber number of droplet on a heated surface. The surface temperatures varied from 72.5~106.1℃ on steel and Teflon, when Weber number was 60, 180, 300. The results are as follows; In the case of the same droplet size, the initial temperature of solid increases the indepth temperature of solid more drop. In the case of the same surface temperature, Weber number increases with increasing the cooling effect of droplet. The time-average heat flux increases with increasing the initial temperature of solid and Weber number. The evaporation time decreases with increasing the initial temperature of solid and Weber number.

물액적에 의한 미연소면의 냉각에 관한 실험적 연구

방창훈,김정수,예용택 한국화재소방학회 2000 한국화재소방학회논문지 Vol.14 No.3

본 연구의 목적은 물액적에 의한 미연소면의 냉각 특성을 연구하는 것이다. 고온고체로는 황동, 탄소강, 동을 사용하였으며 온도범위는 70℃~116℃이다. 액적의 직경은 2.4 mm~3.0 mm로 하였다. CCD카메라를 이용하여 액적의 증발과정을 기록하였으며, 증발시간은 비디오에 기록된 프레임을 분석하여 구하였다. 열전도도가 가장 큰 동의 경우 액적이 떨어진 직후조금 냉각되었다가 일정 온도를 유지하지만 열전도도가 낮은 탄소강의 경우는 증발시간 동안 약 1℃ 정도의 온도 기울기가 나타났다. 고체 표면에서의 액적증발시 무차원 액적체적은 가열체의 재질에 상관없이 무차원 증발시간이 증가할수록 선형적으로 감소한다. The objective of the present work is to examine the cooling characteristics of water droplet on the unburned surface. The hot solid surface material used brass, carbon steel and copper at temperature ranging from 70 to 116℃. the droplet size is from 2.4 mm to 3.0 mm. The CCD camera was used to record the evaporation histories of the droplets. and the evaporation time of the droplet on the hot solid surface could be determined by using frame-by-frame analysis of the video records. It is found that during the droplet evaporation process for copper the temperature remains nearly constant, whereas for carbon steeel the temperature continuously decreases about 1℃. During the droplet evaporation process on the hot solid surface, regardless of solid materials, nondimensional droplet volume decreases nondimensional evaporation time increases.

복사열에 노출된 소방용 방수복의 열적 특성에 관한 연구

방창훈 한국화재소방학회 2003 한국화재소방학회논문지 Vol.17 No.1

본 연구에서는 복사열에 노출된 소방용 방수복의 열적 특성에 대한 실험을 수행하였다. 실험결과 소방용 방수복의 노출시간에 따른 표면의 온도상승은 노출거리가 가까울수록 급격히 일어났다. 또한 복사열유속이 클수록 표면의 온도가 높으며, 정상상태 도달시간은 짧게 나타났다. 소방용 방수복의 노출거리가 멀어질수록 표면의 온도는 급격히 감소하며, 전면과 후면의 온도차도 감소하였다. 복사열유속이 증가할수록 안전노출거리가 증가하였다. 따라서 소방대원의 안전을 위해서는 복사열원으로부터 일정거리이상 떨어져 작업하여야 할 것으로 사료된다. This experimental study shows the thermal characteristics of the fire fighter's waterproof clothing exposed to the radiation heat. From the test results, the surface temperature of the fire fighter's waterproof clothing exposed to the radiation with the passage of time sharply increased as the exposed-distance became closer. Also as the radiant heat flux increased, the surface temperature is higher and the time reaching steady state is sharply shorter. As the exposed-distance become more distant, the surface temperature of the fire fighter's waterproof clothing decreased and the difference of temperature between the front side and the back side of the clothing decreased as well. Besides, the radiant heat flux increased, the safety exposed-distance increased. Therefore it is necessary that fire fighter have to work keeping a fixed safe distance from the radiant heat source.

초등학교 교사의 소방안전의식에 관한 연구 : 영주시를 중심으로 Focusing on Yeongju city

방창훈 한국화재소방학회 2004 한국화재소방학회논문지 Vol.18 No.1

본 연구는 초등학교 교사의 소방안전에 관한 의식을 조사하여 초등학교에서 소방안전교육이 효율적으로 이루어질 수 있도록 하기 위하여 수행되었다 설문조사는 영주시 초등학교에 재직 중인 교사 203명에 대하여 2003년 9월 5일부터 9일까지 실시되었으며, 다음과 같은 결론을 얻었다. 교사들은 소방안전교육의 필요성은 매우 인식하나 수업비중은 조금 낮게 생각하며, 실제적인 교육은 더욱 낮게 이루어지는 것으로 나타났다. 교사들은 안전교육 분야 중 교통안전을 가장 중요하게 여기며, 다음으로 놀이안전, 시설물안전 및 소방안전 순으로 중요하게 생각하였다. 교사들은 소방안전교육에 따른 어려움으로 관심부족(36.0%), 자료 또는 시간 부족(31.5%) 등을 들었으며, 효과적인 소방안전교육을 위한 요구사항으로는 소방안전전문가의 초청교육(62.1%), 교육자료의 개발 보급(16.3%) 등이었다. The purpose of this study is to help the education of fire safety in elementary schools be. given effectively by teachers through the investigation of their recognition on fire safety. To achieve the purpose, 203 elementary school teachers in Yeongju city were interviewed for 5 days from Sep. 5 to 9, 2003. The results of this study are as follows; Teachers recognized the education of fire safety to be very necessary, but they gave less consequence to it relatively and classes for fire safety were done quite a little in actual education. Teachers put the traffic safety on the top in the list of safety education and play safety, facility safety and fire safety follows it in order. Teachers stated lack of interest (36.0%), lack of material and class hours(31.5%) for the difficulty of the fire safety education and they .recognized that a fire safety expert's lecture(62.1%) and development and propagation of teaching material were required for the efficient fire safety education.

복사열에 노출된 작업복의 열적특성에 관한 실험적 연구

방창훈,이진호,예용택 한국산업안전학회 2002 한국안전학회지 Vol.17 No.3

The purpose of this study was to present the thermal characteristics of the working uniform exposed to the radiation heat. The effect of exposure time and exposure distance on the changes and the relationship between physical properties were investigated experimentally. Regardless of the kind of working uniform, the surface temperature of the working uniform with exposed time sharply increases as exposed distance is more close and the reaching tie of steady state is shorter. The surface temperature of working uniform exponentially decreases as exposed distance become more distant. For the safety of the working man, it is necessary that he work far away at a fixed standard distance from the radiant heat source.

액적의 충돌속도에 따른 냉각특성의 변화

방창훈 慶北專門大學(영주경상전문대학) 2002 慶北專門大學 論文集 Vol.21 No.-

The objective of the present work is to examine the variation of cooling characteristics due to impinging velocity of droplet on a heated surface. An experimental study on the evaporation of a small water droplet containing an auditive on a heated, chrome coated(10㎛) steel. The surface temperatures varied from 72.5∼106.1℃ on steel, and weber number were 60, 180, 300. The results are as follows; In the case of the same droplet size, the initial temperature of solid increase the indept temperature of solid more drop. In the case of the same surface temperature, weber number increase with increasing the cooling effect of droplet. The time-average heat flux increase with increasing the initial temperature of solid and weber number. The evaporation time decrease with increasing the initial temperature of solid and weber number.

NaBr을 첨가한 물소화제의 냉각효과에 관한 연구

방창훈,김종석 한국화재소방학회 2001 한국화재소방학회논문지 Vol.15 No.2

본 연구의 목적은 NaBr(30%, w/w)을 첨가한 물소화제의 냉각효과을 연구하는 것이다. 고온체로는 탄소강과 테프론을 사용하였다. 실험에서 고온체 표면의 온도범위는 70℃∼116℃이며 액적의 크기는 2.6mm이다. 실험결과 고온체 내부의 온도는 재질에 관계없이 순수한 물의 경우가 NaBr수용액보다 낮게 나타났으며, 테프론의 경우가 탄소강보다 온도 변화가 크게 나타났다. 또한 제질에 관계없이, 평균 열유속은 순수한 물의 경우가 NaBr수용액 보다 크게 나타났으며, 겉보기 증발시간은 순수한 물의 경우가 NaBr 수용액보다 짧게 나타났다. The objective of the present work is to examine the cooling effect of a water fire extinguishing agent containing NaBr(30%, w/w). The carbon steel and Teflon were used as a hot solid. The temperature on the hot solid surface ranged from 70℃ to 116℃ and water droplet size was 2.6 mm in the experiments. It is suggested that regardless of the hot solid material, the indepth temperature of the case of NaBr solution is lower than that of pure water and the variation of indepth temperature of teflon is higher than that of carbon steel. Regardless of the hot solid material, the time averaged heat flux of the case of pure water is higher than that of NaBr solution. The apparent evaporation time of the case of pure water is shorter than that of NaBr solution.

복사가열조건에서 표면 거칠기에 따른 액적의 증발 냉각

방창훈,권진순,예용택 한국안전학회 2004 한국안전학회지 Vol.19 No.3

The objective of the present work is to examine evaporation cooling of droplet due to surface roughness under radiative heat input condition. The surface temperatures varied from 80~160℃ on aluminum alloy (AL 2024) and surface roughness was 0.18μm, 1.36μm. The results are as follows; Regardless of surface roughness under radiative heat input condition, as droplet diameter is larger, the in-depth temperature of solid decreases and evaporation time increases. In the case of 0.18μm and 1.36μm of surface roughness, the larger the surface roughness is, the less the evaporation time is and the larger the temperature within the solid is. In the case of Ra = 0.18μm, evaporation time and time averaged heat flux for radiative heat input case is shorter than for the conductive case.

표면 거칠기에 따른 액적의 증발 냉각

방창훈,권진순,예용택 한국안전학회 2003 한국안전학회지 Vol.18 No.3

The objective of the present work is to examine evaporation cooling of droplet due to surface roughness on a heated surface. The surface temperatures varied from 80~160℃ on aluminum alloy (AL 2024) and surface roughness was 0.18μm, 1.36μm. The results are as follows; Regardless of surface roughness, as droplet diameter is bigger, the in-depth temperature of solid decreases and evaporation time increases. In the case of same initial temperature on the heated surface, as droplet diameter is smaller and small surface roughness is bigger, evaporation time decreases and time averaged heat flux increases.

A Combination of Melphalan, Prednisone, and 50 mg Thalidomide Treatment in Non-Transplant-Candidate Patients with Newly Diagnosed Multiple Myeloma

( Hye Jung Chang ),( Jae Hoon Lee ),( Young Rok Do ),( Sung Hwa Bae ),( Jung Lim Lee ),( Seung Hyun Nam ),( Sung Soo Yoon ),( Soo Mee Bang1 ) 대한내과학회 2011 The Korean Journal of Internal Medicine Vol.26 No.4

Background/Aims: The clinical efficacy and safety of a three-drug combination of melphalan, prednisone, and thalidomide were assessed in patients with multiple myeloma who were not candidates for high-dose therapy as a firstline treatment. Because the side effects of thalidomide at a dose of ≥ 100 mg daily can be a barrier to effective treatment for these patients, we evaluated the efficacy and safety of a reduced dose of thalidomide, 50 mg, for non-transplant candidates. Methods: Twenty-one patients were treated in 4-week cycles, receiving 4 mg/m2 melphalan and 40 mg/m2 prednisone on days 1-7 and 50 mg thalidomide daily. The primary efficacy outcome was the overall response rate. Aspirin (100 mg daily) was also provided as prophylactic treatment for thromboembolism. Results: The overall response rate was 57.1%; a complete response was seen in 23.8% of patients, a partial response in 33.3%, and stable disease in 9.5%. After a median follow-up time of 16.1 months, the median time to progression was 11.4 months (95% confidence interval, 2.1 to 20.6); the median overall survival was not reached. Grades 3 and 4 adverse events included infection (10%), peripheral neuropathy (5%), diarrhea (5%), thrombosis (10%), and loss of consciousness (10%). Two patients discontinued treatment due to loss of consciousness and neuropathy. Conclusions: Low-dose thalidomide (50 mg) plus melphalan and prednisone is an effective combination drug therapy option for newly diagnosed myeloma patients who are ineligible for high-dose chemotherapy.