• 대한기계학회:학술대회논문집
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• 대한기계학회 2000년도 추계학술대회논문집B
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• pp.738-744
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• 2000

The breakup behaviors of impinging droplet on a hot surface are studied experimentally. The droplets are produced by the dripping method and the breakup behaviors of liquid droplet are recorded by photographs. Experimental conditions are, droplet diameter di : 2.5, 3.2 [mm], weber number : $30{\sim}140$, surface temperature : $28^{\circ}C(room\;temperature){\sim}450^{\circ}C$. Water is used to liquid. As weber number of droplet increases, a liquid sheet, which is formed after the impingement on a hot surface, is disintergrated by the dynamical effect. But at low weber number, it has effected by thermodynamical effect. The breakup behaviors of droplet are divided into three patterns with weber number and surface temperature, non-disintegration, transition and disintegration region. Further, these boundary values are affected by the hot surface temperature and weber number. SMD of breakup droplets are calculated in according to surface temperatures and weber number. The minium SMD of breakup droplets are observed at weber number 65.49, temperature $250^{\circ}C$ and weber number 99.08, temperature $350^{\circ}C$.

• 설비공학논문집
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• 제23권1호
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• pp.54-60
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• 2011

Procedures for estimation of insulation thickness for a horizontal pipe for condensation control or personnel protection has been investigated, parallel to the previous work of a vertical wall case. Parameters include pipe diameter, emissivity, thermal conductivity, and operating temperatures. The results indicated that the surface emissivity plays a very important role in the design of insulation, specially for the case of high temperature application with low Bi. The effect of surface radiation in such case could be up to 65% of the total. Required insulation thickness for the surface temperature control increases as pipe diameter increases and as surface emissivity decreases. Adequate revision of specifications or standards to include newly invented insulation materials with high emissivity has been also suggested.

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 2003년도 학술대회지
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• pp.97-104
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• 2003

The surface temperature at the interface of bodies in a sliding contact is one of the most important factors influencing the behavior of machine components. So the calculation of the surface temperature at a sliding contact interface has long been an interesting and important subject for tribologist. In this study to verify estimation of temperature rising, calculated temperatures were compared with measured temperatures. It is possible to calculate bulk and flash temperature.

• 한국제4기학회지
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• 제24권2호
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• pp.1-11
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• 2010

지표 특성 차이에 따라 외부강제력에 대한 차별적인 반응을 보이는 지표 평형온도 분포를 실험하기 위해 에너지 균형 모형(Energy Balance Model, EBM)이 사용되었다. EBM은 입사되는 복사에너지가 각 위도별로 수송되는 에너지와 방출되는 복사에너지의 합과 균형을 이루었을 때의 온도를 산출한다. 지구의 에너지 원천인 태양복사에너지를 전지구 에너지 균형에 있어 중요하게 취급하기 위하여 위도별 알베도 변화뿐만 아니라 해륙의 분포 차이에 따른 에너지 균형을 고려한 지구 평형온도 분포에 관한 실험이 수행되었으며, 입사되는 태양복사에너지량을 강제력으로 하여 위도별 알베도의 선형적인 증감, 극지역 알베도의 5%, 10%, 15% 증감에 대한 반응, 극과 중위도 지역에서의 상반된 증감에 대한 반응을 실험하였다. 그리고 얼음-알베도 피드백의 유무에 대한 실험도 수행되었다. 극지역의 알베도를 증가시키면 입사되는 태양에너지를 차단시켜 위도별 열수송을 감소시키는데 이는 극지역을 저에너지 상태로 유지시킴으로써 저위도에서부터의 에너지 수송을 강화시킨다. 이러한 수송량의 차이로 인해 중위도 지역의 온도 변화는 극지역에 비해 크게 나타난다. 육지는 해양에 비해 열용량이 작기 때문에 평형온도에 도달하는 시간이 짧으며 알베도에 따른 온도변화에 민감하여 해양과의 온도차이를 유발시킨다. 따라서 평형온도는 지표가 가지는 특성인 알베도와 열용량의 차이에 따라 다르게 나타나며 알베도가 증가함에 따라 감소하고 열용량이 작을수록 변화율이 큰 특징이 있다. 얼음-알베도 피드백은 알베도의 선형적인 증가에 따른 지구 평형온도의 감소를 가속화시키지만 국지적으로는 비선형적인 감소를 보인다.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2004년도 추계학술대회
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• pp.1225-1230
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• 2004

The effects of substrate material on the local heating performance of microheaters are studied by both numerical analysis and experiment. Transient conduction analysis shows that the substrate material with low thermal conductivity is critical to the local heating and fast response. A measurement technique for surface temperature field in microscale is newly proposed, which uses temperature sensitive fluorescent dye coated on the surface. The measured surface temperature fields on microheater arrays fabricated on different substrates are presented.

• 반도체디스플레이기술학회지
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• 제10권4호
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• pp.21-23
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• 2011

Uniformity of plasma etching processes critically depends on the wafer temperature and its distribution. The wafer temperature is affected by plasma, chucking force, He back side pressure and the surface temperature of ESC(electrostatic chuck). In this work, 3D mathematical modeling is used to investigate the influence of the geometry of coolant path and the temperature distribution of the ESC surface. The model that has the coolant path with less change of the cross-sectional area and the curvature shows low standard deviation of the ESC surface temperature distribution than the model with the coolant path of the larger surface area and more geometric change.

• 대한기계학회논문집B
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• 제25권6호
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• pp.845-852
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• 2001

The characteristics of evaporation cooling of single droplet on a heated surface were studied experimentally. The two kinds of heater modules were tested to measure cooling characteristics of metal surface (high conductivity) and Teflon surface (low-energy surface, low conductivity). The results showed that time averaged heat flux during droplet evaporation increased exponentially with initial surface temperatures of brass, copper and steel. The heat flux and evaporation time did not varied with metal conductivities. However, the temperature drop after the deposition of droplet was larger on Teflon than on the metals. Thus, the correlation of interface temperature between liquid droplet and metal surface was proposed as a function of the initial surface temperature of heating materials, which could be applied to both metal and non-metal ones.

• 대한임상전기생리학회지
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• 제5권2호
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• pp.61-72
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• 2007

INTRODUCTION: Local heat and cold application has been frequently used as means of muscle relaxation and blood circulation or reinforcing muscle strength, relaxing muscle tension in clinical situation. In particular, it has been known that long-term heat and cold application for relaxing muscle tension inhibits muscle spasticity or tension. But, it has been rarely reported that what influences of heat and cold application on activation of muscle action potential. Therefore, this study aims to analyze surface temperature and electromyography activities according to the heat and cold application. METHODE: Subjects of this research were 10 normal men and women (5 men, 5 women). Hot pack and cold pack was applied to vastus medialis muscle of thigh and rectus femoris muscle for 20 min. Surface temperature of vastus medialis muscle and rectus femoris muscle was measured, knee joint of subjects was in $45^{\circ}$ flexion, sitting on a chair, maximal isometric contraction was induced, surface electromyography (sEMG) signals were collected and root mean square (RMS) and median frequency (MOF) were analyzed. All measurements were conducted before and immediately after experiment, 10 min., 20 min. and 30 min. after experiment. Data were analyzed with SPSS 12.0 program, comparison of changes in superficial temperature and sEMG signals through repeated measurement was conducted with repeated measures ANOVA and significance level $\alpha$ was 0.05. RESULTS: Changes of surface temperature of vastus medialis muscle according to cold application were radically decreased immediately after application, but it was recovered after 30 min. of application and it showed significant difference (F4. 36=72.216, P<0.001). Surface temperature of rectus femoris also showed radical decrease immediately after application, but it was recovered after 30 min. of application and showed significant difference (F4. 36=88.930, P<0.001). Changes of surface temperature of vastus medialis muscle according to heat application were radically increased immediately after application, but it was recovered after 30 min. of application and it showed significant difference (F4. 36=27.267, P<0.001). Surface temperature of rectus femoris also showed radical decrease immediately after application, but it was recovered after 30 min. of application and showed significant difference (F4. 36=19.774, P<0.001). Changes of sEMG by heat and cold application were no statistical difference. Surface temperature of skeletal muscle after heat and cold application showed significant change for 30 min., but it was found that increase or decrease of surface temperature had not great influence on sEMG activities.

• 한국방사선학회논문지
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• 제6권6호
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• pp.521-529
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• 2012

본 연구의 목표는 신발 굽 높이에 따른 Kager씨 삼각 면적의 방사선영상 변화와 후종족부의 표면온도 변화를 알아보고자 연구하였다. 카이거씨 면적은 단순 방사선촬영검사와 인피니티 영상저장전송시스템을 이용하여 측정 하였다. 후종족부의 표면온도는 전산화적외선체열검사를 이용하여 측정하였다. 운동화 착용 대상자에게 신발 굽 높이가 다른 하이힐을 착용시켜 카이거씨 삼각 면적과 후종족부의 표면온도 차이를 분석 하였다. 하이힐 대상자들은 운동화 대상자들에 비하여 카이거씨 삼각 면적이 $0.88cm^2$, 후종족부의 표면온도가 $1.4^{\circ}C$ 각각 감소하였다. 최고신장과 최저신장의 카이거씨 면적과 표면온도의 차이는 운동화와 하이힐에서 각각 $0.9cm^2$, $1.2cm^2$, $1.6^{\circ}C$, $0.5^{\circ}C$이며 모두 미세한 차이를 나타냈다. 최고체중과 최저체중의 카이거씨 면적과 표면온도의 차이는 운동화와 하이힐에서 각각 $1.8cm^2$, $0.8cm^2$, $1.1^{\circ}C$, $0.2^{\circ}C$이며 체중이 높을수록 카이거씨 면적과 표면온도가 감소하였다. 하이힐 최장시간 착용자와 최저시간 착용자의 카이거씨 면적과 표면온도의 차이는 각각 $0.8cm^2$, $1.4^{\circ}C$, 이며 착용시간이 증가함에 따라 카이거씨 면적과 표면온도가 감소하였다. 결론적으로 하이힐을 장시간 착용하면 후종족부 통증과 혈류 장애를 유발 할 것으로 고려된다.

• 한국측량학회지
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• 제36권4호
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• pp.263-270
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• 2018

지표면 온도는 지면-대기의 상호 순환을 이해하는데 중요한 요소로 알려져 있지만 시공간적 변동성이 크기 때문에 정규적인 관측은 거의 이루어지지 못하고 있다. 기존의 지표면 온도는 위성 영상을 이용하여 관측하고 있지만 위성의 특성상 긴 재방문주기와 낮은 정확도의 한계를 가지고 있다. 본 연구에서는 기존의 위성 영상을 활용한 지표면 온도 관측의 대체가능성을 확인하기 위해 무인항공기에 열적외선 센서를 탑재하여 단일 영상을 취득하였다. 취득된 영상은 JPEG 영상에서 TiFF 영상으로 변환하여 정사영상을 제작하였으며 정사영상의 DN값을 이용하여 실제 지표면 온도로 계산하였다. 계산된 피복별 지표면 온도의 정확도를 평가하기 위해 영상촬영과 동시에 적외선 온도계로 직접 관측한 지표면 온도와 비교하였다. 두 가지 방법으로 관측한 지표면 온도를 비교 했을 때, 모든 피복들에 대해서 정확도가 열적외선 센서의 관측 정확도 이하로 나타났다. 따라서 무인항공기에 탑재된 열적외선 센서를 이용하여 기존의 지표면 온도 관측 방법인 위성 영상의 대체 가능성을 확인하였다.