• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.320-325
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• 2001

In this study, CT specimen were prepared from Pressure Vessel Steel which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at $25^{\circ}C$, -3$0^{\circ}C$, -6$0^{\circ}C$, -8$0^{\circ}C$, -10$0^{\circ}C$ and -12$0^{\circ}C$ and in the range of stress ratio of 0.05 and 0.3 by means of opening mode displacement. At the constant street ratio, the threshold stress intensity factor range ΔK$_{th}$ in the early stage of fatigue crack growth(Region I) and stress intensity factor range ΔK in the stable of fatigue crack growth(Region II) was increased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm do/dN -ΔK in RegionII, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It was assumed that the fatigue crack growth rate do/dN is rapid in proportion to descending temperature in Region IIand the cryogenic-brittleness greatly affect a material with decreasing temperature.e.greatly affect a material with decreasing temperature.

• 한국해양공학회지
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• 제15권3호
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• pp.100-106
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• 2001

In this study, CT specimens were prepared from Pressure Vessel Steel which was used for pressure vessel plates for room and low temperature service. And we got the following characteristics from fatigue crack growth test carried out in the environment of room and low temperature at $25^{\circ}C$, -3$0^{\circ}C$, -6$0^{\circ}C$, -10$0^{\circ}C$ and -12$0^{\circ}C$ and in the range of stress ratio of 0.05 and 0.3 by means of opening mode displacement. At the constant stress ratio, the threshold stress intensity factor range ${\Delta}K_{th}$ in the early stage of fatigue crack growth (Region I) and stress intensity factor range ${\Delta}K$ in the stable of fatigue crack growth (Region II) was increased in proportion to descent temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm da/dN $-{\Delta}K$ in Region II, that is, the fatigue crack growth exponent m increased with descending temperature at the constant stress ratio. It was assumed that the fatigue crack growth rate da/dN in proportion to descending temperature in Region II and the cryogenic-brittleness greatly affect a material with decreasing temperature.

• 한국어류학회지
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• 제23권2호
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• pp.87-94
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• 2011

본 연구는 통상적으로 활어 수송을 위해 사용되는 수온 $15{\pm}2^{\circ}C$ 범위에서 단기 수온 강하와 단기간 먹이제한을 했을 때 넙치의 스트레스 반응과 생리상태를 혈중 생화학 인자와 4종류의 갑상선호르몬의 변화를 통해 파악하고, 이 결과들을 바탕으로 어류의 스트레스 및 생리활성 지표로서 분석 인자들의 효용성을 검토하고자 하였다. 먹이제한 실험은 1년생 넙치 양성어(전장 $32.9{\pm}1.2$ cm, 체중 $348.0{\pm}34.7$ g)를 이용해 8일간 실시하였고, 수온변화 실험은 1년생 양성어(전장 $32.7{\pm}1.2$ cm, 체중 $327.1{\pm}33.6$ g)를 이용해 8일간 수온을 $15.8^{\circ}C$에서 $13.3^{\circ}C$로 하강시키며 실시하였다. 혈중 생화학적 분석 인자는 ALT, AST, TP, GLU, 전해질($Na^+$, $K^+$, $Cl^-$), thyroid hormones (total $T_3$ & $T_4$ free $T_3$ & $T_4$)의 혈중 변화로 이루어졌다. 먹이섭식 제한 결과, AST, ALT 및 전해질에서는 절식기간 동안 어떠한 유의한 변화를 찾아볼 수 없었지만, TP와 GLU는 유의하게 감소하는 경향을 보였다. 갑상선호르몬 농도의 경우, 조사된 4종류 모두 절식기간이 길어지면서 감소하는 경향이 있었으며, 통계적으로 $FT_4$와 $TT_3$가 개시에 비해 실험 종료시 유의하게 감소하였다. 수온하강 실험의 경우, AST, ALT, TP 및 전해질 및 갑상선호르몬 농도에서 유의한 변화는 없었으나, GLU에서는 온도하강에 따른 농도 감소가 관찰되었다(P<0.05).

• 임산에너지
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• 제22권1호
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• pp.24-29
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• 2003

낙엽송 간벌재 톱밥보드로 우드세라믹을 제조한 후 수지함침율 및 소성온도에 따른 우드세라믹의 표면온도 변화를 조사하였다. 히터의 표면온도가 증가함에 따라 우드세라믹의 표면온도도 급속히 증가하였으며 수지함침율 70∼80%, 소성온도 800∼1000℃ 조건으로 제조된 우드세라믹의 표면 온도가 상대적으로 높았다. 히터의 표면온도보다 우드세라믹 표면온도의 하강속도가 느려 우드세라믹이 오랜 시간 열을 유지하고 있음을 알 수 있었다.

• Journal of the Korean Wood Science and Technology
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• 제35권3호
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• pp.22-28
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• 2007

소나무 간벌재로 톱밥보드를 만든 후 우드세라믹을 제조하여 승온속도 및 최고온도에서의 유지시간에 따른 우드세라믹의 표면온도의 변화를 조사하였다. 승온속도 $2^{\circ}C/min$와 유지시간 1시간의 조건으로 제조된 우드세라믹의 표면 온도가 가장 높았다. 히터의 표면 온도보다 우드세라믹의 표면온도의 하강 속도가 느려 우드세라믹이 오랜 시간 열을 유지하고 있음을 알 수 있었다.

• 전기학회논문지
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• 제58권6호
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• pp.1157-1165
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• 2009

In AC-PDP, it is necessary to achieve high luminance efficiency, high luminance and high definition by adopting technologies such as high xenon concentration, MgO doping, and long gap. However, it is very difficult to apply above technologies because they make the driving voltage margin reduced. Especially, high Xe concentration technology for high efficacy makes not only the driving voltage margin reduced but also the stability of reset discharge decreased at low temperature. In this paper, we studied temperature and voltage dependent stability of reset discharge and present the experimental results of the discharge characteristics at low temperature. In addition, we suggested the mechanism of bright noise and black noise at low temperature. Finally, we proposed double reset waveform to improve the bright noise and descending scan time method to improve the black noise.

• 한방재활의학과학회지
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• 제26권2호
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• pp.85-96
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• 2016

Objectives This study was performed to evaluate the effects of acupuncture, electro-acupuncture and acupuncture with pulsed electromagnetic therapy on upper extremity of healthy people and hemiplegic patients by D.I.T.I.. Methods 20 healthy people and 20 hemiplegic patients caused by stroke were selected. They have been treated three different types of treatment; acupuncture, electro-acupuncture and acupuncture with pulsed electromagnetic therapy. And skin temperature of upper extremity has been measured before and after each treatment by D.I.T.I.. The thermographic data was analyzed by 'Independent T-test' and 'Repeated measures ANOVA test'. Results 1. In healthy group, there was very statistical significant difference (p<0.001) of the amount of thermal change by each treatment, and the amount of change was arranged in descending order; acupuncture with pulsed electromagnetic, acupuncture and electro-acupuncture. 2. In hemiplegic group, the skin temperature of hemiplegic side was $0.97^{\circ}C$ cooler than non-hemiplegic side. 3. Skin temperature of all hemiplegic patients was increased after acupuncture treatment. 4. In hemiplegic group, there was statistical significant difference (p<0.05) of the amount of thermal change by each treatment, and the amount of change was arranged in descending order; acupuncture with pulsed electromagnetic, acupuncture and electro-acupuncture. Conclusions The results indicate that acupuncture, electro-acupuncture and acupuncture with pulsed electromagnetic therapy had good effect on the change of skin temperature by stimulating sympathetic nervous system.

• 한국어류학회지
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• 제24권1호
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• pp.41-47
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• 2012

본 연구는 조기류(참조기, 수조기)의 양식생물학적 기초자료를 확보하고자 육상수조에서의 성장 특성 및 저수온 노출에 대한 영향을 조사하였다. 1년 사육기간동안 수조기가 참조기에 비해 성장이 빨랐고, CF는 모두 9월에 가장 높게 나타났으며, DFI는 모두 9~10월에 최대값을 보인 후 낮아졌다. 사료계수는 참조기가 2.20, 수조기가 1.34였다. 완만한 수온 하강에 대한 영향은 참조기와 수조기 미성어 모두 $4.7^{\circ}C$ 이하에서 폐사가 발생하였으며, 조기류 월동의 임계수온은 $9^{\circ}C$로 나타났다.

• Journal of Acupuncture Research
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• 제19권3호
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• pp.64-76
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• 2002

Objective : The purpose of this study is to investigate the mechanism and effect of moxibustion objectively and to be used as the quantitative data for developing the new thermal stimulating treatment by observing the combustion characteristics of commercial moxaes. Methods : We have selected two types(large-size moxa A(LMA), large-size moxa B(LMB)) among large moxaes used widely in the clinic. We examined combustion times, temperatures, temperature gradients in each period during a combustion of moxa. Results : 1. The ascending temperature gradient measured in the central point of non-contacted surface was fastest, the average ascending temperature gradient of both moxaes was $0.0384^{\circ}C/sec$, $0.0123^{\circ}C/sec$ respectively, 3.1 times faster in LMA. The maximum ascending temperature gradient was also about 2.9 times faster in LMA. The time required for the maximum ascending temperature gradient from ignition was 254sec, 411sec respectively. 2. The minimum descending temperature gradient in the retaining period was $-0.0250^{\circ}C/sec$, $-0.0090^{\circ}C/sec$ respectively and the average descending temperature gradient was $-0.0160^{\circ}C/sec$, $-0.0037^{\circ}C/sec$ respectively on the non-contact surface. 3. On the basis of the non-contact surface($A_I$), the time at which the effective stimulus period began to occur was about 264sec, 796sec respectively after an ignition, the time at which the maximum temperature began to occur was about 373sec, 1323sec respectively after an ignition, and the maximum temperature was $0.9^{\circ}C$ higher in LMA. The maximum ascending temperature gradient was also about 4.2 times faster in LMA. Conclusion : It was thought that not only the figure of moxicombustion device, but also the form and size of moxa had influence on the combustion characteristics deciding the performance of stimulus seriously.

• Journal of Advanced Marine Engineering and Technology
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• 제25권6호
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• pp.1228-1236
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• 2001

In this study, CT specimens were prepared from ASTH A5l6 steel which was used for pressure vessel plates for moderate and lower temperature service. And we got the fellowing characteristics from fatigue crack growth test carried out in the environment of room and low temperature at $25^{\circ}C$ , $-30^{\circ}C$, $-60^{\circ}C$, $-80^{\circ}C$, $-100^{\circ}C$ and $-120^{\circ}C$ and in the range of stress ratio of 0.1, 0.3 by means of opening mode displacement. At the constant stress ratio, the Threshold stress intensity factor range ΔAKth in the early stage of fatigue crack growth (Region I) and stress intensity factor range $\DeltaK$ in the stable of fatigue crack growth (Region II) was increased in proportion to descend temperature. It assumed that the fatigue resistance characteristics and fracture strength at low temperature is considerable higher than that of room temperature in the early stage and stable of fatigue crack growth region. The straight line slope relation of logarithm da/dN-$\Delta$K in Region II that is, the fatigue clack growth exponent m increased with descending temperature at the constant stress ratio. It assumed that the fatigue crack growth rate da/dN is rapid in proportion to descend temperature in Region II and the cryogenic-brittleness greatly affect a material with decreasing temperature.