• The Korean Journal of Pain
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• 제22권2호
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• pp.146-150
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• 2009

Background: A skin temperature difference is one of the variables used in the diagnosis of complex regional pain syndrome. However, there have been no reports as to whether the real (${\Delta}T$) or absolute value ($|{\Delta}T|$) of skin temperature differences should be used in the diagnosis of complex regional pain syndrome. This study was conducted to compare the diagnostic validity of ${\Delta}T$ with $|{\Delta}T|$ for complex regional pain syndrome using receiver operating characteristic curves (ROC). Methods: Infrared thermographic images were obtained from the 144 patients who were suspected to have CRPS in a unilateral limb. After ${\Delta}T$ and $|{\Delta}T|$ calculation from the thermographic image, ROCs of ${\Delta}T$ and $|{\Delta}T|$ were developed, and the areas under the curve (AUC) for the ROC curves were compared. Results: AUCs of ${\Delta}T$ and $|{\Delta}T|$ were 0.520 and 0.746 respectively, this difference was statistically significant (P < 0.001). Conclusions: Absolute skin temperature difference shows greater validity in the diagnosis of CRPS than ${\Delta}T$. Therefore, $|{\Delta}T|$ is more useful when comparing the skin temperature of CRPS patients.

• 한국광학회지
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• 제4권3호
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• pp.354-358
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• 1993

지그재그 슬랩 레이저의 글라스 내부 온도분포를 마하-젠더 간섭계로 측정하였다. 슬랩 레이저글라스의 파괴 원인은 슬랩글라스의 표면과 중심부의 온도차로 이 온도차 ${\Delta}T_0$가 $110^{\circ}C$, $62^{\circ}C$에서 두 장의 레이저글라스가 파괴되었다. 고평균출력 글라스레이저를 설계하는데 있어서 안전 작동을 이하여 슬랩글라스 표면과 중심부의 온도차 ${\Delta}T_0$가 $50^{\circ}C$를 넘지 않도록 해야한다.

• 한국세라믹학회지
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• 제35권10호
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• pp.1094-1100
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• 1998

The thermal fatigue behavior of alumina ceramics was investigated by water quenching method. Single-quench thermal shock tests were performed to decide the critical thermal shock temperature difference ($\Delta$Tc) which was found to be 225$^{\circ}C$ Cyclic thermal shock fatigue tests were performed at temperature diff-erences of 175$^{\circ}C$, 187$^{\circ}C$ and 200$^{\circ}C$ respectively. After cyclic thermal shock fatigue test the distributions of retained strength and crack were observed. Retained strength was measured by four point bending method and crack observation method bydye penetration. In terms of the retained strength distribution the critical number of thermal shock cycles(Nc) were 7 for $\Delta$T=200$^{\circ}C$, 35 for $\Delta$T=187$^{\circ}C$ and 180for $\Delta$T=175$^{\circ}C$ respec-tively. In terms of the crack observation the critical number of thermal shock cycles were 5 for $\Delta$T==200$^{\circ}C$ 20 for $\Delta$T==187$^{\circ}C$ and 150 for $\Delta$T=175$^{\circ}C$ respectively. The difference of Nc investigated by two different methods is due to the formation of the longitudinal cracks which had no effect on the four point bending strength. Therefore the thermal fatigue behavior of alumina ceramics could be more accurately described by the crack observation method than the retained strength measurement method.

• 대한한방체열의학회지
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• 제5권1호
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• pp.46-58
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• 2006

Purpose: We intended to observe the relations between Chiljehyangbuhwan and abdominal & palmar temperature according to primary dysmenorrhea severity. Methods: We selected the 100 primary dysmenorrhea patients by the screening tests (first screening test-inquiry, second screening test-clinical test. additionally WHR (Waist-to-Hip ratio) by Inbody 2.0). By the fixed blocked randomization and double blind method, Chiljehyangbuhwan or placebo was administered for 1 menstration period. Finally, 69 patients remainded. Before and after administration, we measured 4 points abdominal temperature (Chon-jung (CV17), Chung-wan(CV12), Kwan-won(CV4). Chung-guk(CV3)) by DITI(DOREX Inc., USA). And then we checked the difference of temperature $({\Delta}T)$ between CV17 and CV12/CV17 and CV4/CV17 and CV3/CV12 and CV4/CV12 and CV3. Also, we measured 2 points (palmar region, upper front of forearm) for the difference of palmar temperature $({\Delta}T)$. Then, we checked palmar temperature minus upper front of forearm temperature and took an average of right and left ${\Delta}T.$ After that. we compared ${\Delta}T$ with primary dysmenorrhea severity evaluated by VRS (verbal rating scale) and MVRS (multidimensional verbal rating scale). In dysmenorrhea severity. we standardized scale score and 3-group-severity by score (mild, moderate. severe). Besides, we compared palmar ${\Delta}T$ with abdominal ${\Delta}T$. For statistics, we used ANOVA and Spearman's rho correlations. SPSS 13.0 for windows. Results: In case of MVRS, though Chiljehyangbuhwan was correlated to abdominal ${\Delta}T$(CV12 and CV3/CV12 and CV4). it was not correlated to palmar ${\Delta}T$. In case of VRS, though Chiljehyangbuhwan was not correlated to abdominal ${\Delta}T$. it was correlated to palmar ${\Delta}T$. However. palmar ${\Delta}T$ was not correlated to abdominal ${\Delta}T$. Statistically they showed significant result (p<0.05). Conclusion: The primary dysmenorrhea patients showed that severity by MVRS was connected with abdominal ${\Delta}T$ (CV12 and CV3/CV12 and CV4) and severity by VRS was connected with palmar ${\Delta}T$ after Chiljehyangbuhwan administration. So we can consider Chiljehyangbuhwan partially effects the abdominal & palmar temperature according primary dysmenorrhea severity. However, palmar temperature was not correlated to abdominal temperature. Therefore, we need further study.

• 태양에너지
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• 제8권2호
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• pp.46-56
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• 1988

This investigation concerns thermal stratification of the water due to the temperature difference (${\Delta}T=T_{\infty}-T_i$) between the mean temperature of the water in the test tank (1m wide, 1m high, 2.1m long) and the temperature of the inflow water into the tank; flow rate of circulating water and height of the sink diffuser in the test tank. The additional objectives was to observe a stratification phenomena near an interface by measuring the velosities and the temperature difference and investigate an availabilities of the better effective hot water through establishing thermocline near an interface around the bottom of the tank. Following results were obtained through the experiments. 1. When the flow rate was constant and the temperature difference (${\Delta}T=T_{\infty}-T_i$) between the mean temperature of the flow in the test tank and the temperature of the inflow water increased by 5.6, 9.5, 13.5($^{\circ}C$), obtained the better effective advantage of hot water and the stress near an interface increased gradually. 2. When the ${\Delta}T=T_{\infty}-T_i$ was constant and flow rate increased by 4.0, 4.8, 6.4, 8.0 (LPM), obtained the better effective advent age of hot water and the mean stress near an interface increased gradually. 3. When the height of the sink diffuser was 25cm from tank bottom in comparison with 50cm, obtained the better effective advantage of hot water and the mean stress near an interface increased.

• Membrane and Water Treatment
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• 제10권5호
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• pp.321-330
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• 2019

The objective of this study was to examine the recovery of the power plant cooling tower blowdown water (CTBD) by membrane distillation. The experiments were carried out using a flat plate poly vinylidene fluoride (PVDF) membrane with a pore diameter of $0.22{\mu}m$ by a direct contact membrane distillation unit (DCMD). The effects of operating parameters such as transmembrane temperature difference (${\Delta}T$), circulation rate and operating time on permeate flux and membrane fouling have been investigated. The results indicated that permeate flux increased with increasing ${\Delta}T$ and circulation rate. Whereas maximum permeate flux was determined as $47.4L/m^2{\cdot}h$ at ${\Delta}T$ of $50^{\circ}C$ for all short term experiments, minimum permeate flux was determined as $7.7L/m^2{\cdot}h$ at ${\Delta}T$ of $20^{\circ}C$. While $40^{\circ}C$ was determined as the optimum ${\Delta}T$ in long term experiments. Inorganic and non-volatile substances caused fouling in the membranes.

• KSBB Journal
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• 제5권4호
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• pp.403-410
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• 1990

Application of the Rheocatch Hotwire Monitoring System for food biotechnology process was evaluated. The growth of microogranism, E coli (JM 83 and Sigma) and Corynesccfertun glutamicum, were monitored. in the fermentor. The cell growth could not be detected the temperature differences between the hotwire and samples($\Delta$T) as indicated by the monitoring system during the fermentation processes. The cell concentration of less than 2g/dl was not sufficient to generate the measurable temperature difference in the fermentor. In order to calibrate the Rheocatch Monitoring System, the temperature difference as a function of solute concentration (microbial cells, sodium cholide, sucrose and dextran) was studied. The relationship between $\Delta$T and the concentration of microbial cells, sucrose and dextran can be expressed in a power series. Further studied with dextran indicated that viscosity and/or kinematic viscosity increase exponentially with an increase in $\Delta$T This is regardless of the concentration and molecular weight of dextran. $\Delta$T linearly increases with the logarithm of molecular weight, while the logarithm of viscosity and the logarithm of kinematic viscosity increase with the logarithm of molecular weight.

• 한국가스학회지
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• 제21권5호
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• pp.1-8
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• 2017

현재 산업현장의 가스 안전관리는 접촉식은 LDAR(Leak Detection and Repair), 비접촉식은 레이저 메탄검지기와 IR 카메라를 사용하고 있다. LDAR 방식은 전체 관리를 하는데 많은 인력과 소요시간이 들고, 관리자가 측정을 위해 가까이 접근해야 하므로 안전의 위협을 받을 수 있어 비접촉식이 더 효율적이다. 비접촉식에서 IR(infrared)을 이용한 가스 측정 방안에 대한 연구가 주목받고 있다. 산업 가스 중 메탄가스를 활용하여 측정 거리에 따라 가스 분출량을 변화시켜 OGI(optical gas image)를 촬영하였다. 본 논문은 가스의 배경온도차이가 OGI 의 선명도에 미치는 영향을 확인하기 위한 실험이다. OGI를 통해 가스의 구름모형을 정확하고, 선명하게 보기 위하여 배경온도 조절판을 제작하였다. 배경온도 조절판을 통해 배경온도와 대기온도 차이가 ${\Delta}T0^{\circ}C$일 때 보다 ${\Delta}T-6^{\circ}C$ 차이의 낮은 온도 조건으로 OGI 촬영을 한 결과가 육안을 확인하였을 때 더 선명한 차이가 나타났다. 선명도 차이의 객관성을 부여하기 위하여 추가로 MATLAB 의 RGB 분석법으로 확인한 결과, ${\Delta}T$가 $-6^{\circ}C$ 일 경우 RGB 값의 수치가 약 20% 낮게 나왔다. 배경온도가 대기온도보다 $-6^{\circ}C$ 낮을 때 더 선명하게 보이는 것은 총 복사법칙으로 설명이 가능하다. 가스의 배경온도가 대기온도에 비해 낮게 될 때 OGI 렌즈로 들어오는 가스의 복사에너지가 증가되어 가스가 더 선명하게 보이게 된다.

• 설비공학논문집
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• 제13권3호
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• pp.145-152
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• 2001

Low Rayleigh number thermal convection in a fluid layer confined between two-infinite horizontal walls kept at spatially sinusoidal temperature distributions, T_L=T_m+\Delta T\sin \kappax,\;T_U=T_m+\Delta T\sin(\kappax-\beta)$, is theoretically investigated by a regular perturbation expansion method. For small wave numbers, an upright cell is formed between the two walls at $\beta$=0. The cell is tilted, as the phase difference increases, and a flow with tow counter-rotating eddies occurs at $\beta=\pi$. when the wave number is large, isolated eddies are formed near the lower and upper walls, for all the phase differences. There exists a wave number at which maximum heat transfer rate at the walls occurs, at each of the phase differences. And the wave number increases with increase of the phase difference. for a fixed wave number, the heat transfer rate decrease with increase of the phase difference.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.239-239
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• 2010

해양에서 물리적 에너지원으로는 조류, 조력, 파력, 해양온도차에너지(Ocean Thermal Energy : OTE)가 있으며, OTE 개발을 위해서는 우선 부존 자원량 파악과 개발적지 선정이 선행되어야 한다. 이를 위해 대상해역의 표층과 심층간의 수온차이 값(${\Delta}T$)에 대한 연중출현확률의 산정이 필요하다. 본 연구에서는 이러한 ${\Delta}T$의 연중출현확률을 산정하기 위해 남해 해역을 대상으로 47년간(1961~2007) 격월 별(2, 4, 6, 8, 10, 12월)로 관측된 93개 정점의 정선해양관측자료(국립수산과학원)를 사용하였다. ${\Delta}T$값을 정량화 하고자 정점 별 ${\Delta}T$(> $5^{\circ}C$, > $10^{\circ}C$, > $15^{\circ}C$)의 연중출현확률을 빈도분석과 조화분석 방법을 사용하여 계산하고 이를 공간적으로 광역적 규모와 지역적 규모에서 두 방법의 장단점을 비교, 분석 하였다.