• 대한기계학회:학술대회논문집
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• 대한기계학회 2003년도 춘계학술대회
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• pp.90-95
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• 2003

Fracture behaviors of pipes with local wall thinning are very important for the integrity of nuclear power plant. In pipes of energy plants, sometimes, the local wall thinning may result from severe erosion-corrosion (E/C) damage. However, the effects of local wall thinning on strength and fracture behaviors of piping system were not well studied. In this paper, the monotonic bending tests were performed of full-scale welded and unwelded carbon steel pipes with local wall thinning. A monotonic bending load was applied to straight pipe specimens by four-point loading at ambient temperature without internal pressure. The observed failure modes were divided into four types; ovalization, crack initiation/growth after ovalization, local buckling and crack initiation/growth after local buckling. Also, the strengths of welded and unwelded piping system with local wall thinning were evaluated.

• Applied Biological Chemistry
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• 제33권1호
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• pp.8-13
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• 1990

우리나라에서 생산되는 장려품종 중 팔달, 단엽, 장백, 백운, 장엽콩과 재래종 중 검정콩, 갈색아주까리콩 등 7품종을 대상으로 형태적 특성과 표피의 색, 고형분 및 단백질의 추출 수율, 콩의 색소용출속도 등을 조사하였다. 그 결과 콩 개체의 무게는 갈색아주까리콩이 가장 높고 단엽, 장백이 가장 낮은 값을 보였다. 표피의 색에서는 'L'값은 장백이 가장 높았으며 팔달, 백운, 장엽, 단엽 등도 비교적 높은 'L'값을 나타내었다. 'a', 'b'값에서는 장엽이 높았고 검정콩과 갈색아주까리콩이 비교적 낮은 'b'값을 보였다. 콩을 마쇄하여 물로 추출할 때 고형분과 단백질의 수율은 3회까지 대부분이 추출되었으며 이때 이들의 수율은 각각 73.2 %, 83.2 %이었다. 콩 표피의 색소의 용출은 추출온도와 시간에 따라 큰 영향을 받았다. 평형에 도달한 흡광도(A)와 추출온도(T)와의 관계는 A=aT+b의 관계로 표시할 수 있었으며, 색소용출 속도와 온도와의 관계는 $60^{\circ}C$를 중심으로 두개의 직선관계가 있었다. 이 관계에서 계산된 활성화에너지는 고온보다 저온이 더 높았고, Local 1과 Local 2가 가장 높은 활성화에너지 값을 보여 주었다.

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2004년도 춘계학술발표대회 논문집
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• pp.186-189
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• 2004

A thermal model of carbon spun yam is presented. The unit cell of spun carbon yam is divided into a number of volume elements and the local material properties have been given to each element. By using Finite Difference Method (FDM), temperature distribution in the unit cell can be obtained. Effective thermal conductivity of the spun carbon yam unit cell is calculated using the temperature distribution and thermal conductivities of local elements.

• 전자공학회논문지T
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• 제36T권2호
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• pp.70-76
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• 1999

최근에 휴대전화기가 저 연령층까지 널리 보급되어 어린이들의 두부내에 열점(hot-spot)형성문제가 염려되고 있는 실정이다. 전자파의 인체영향이 체온상승의 열적작용에 의한 것이라고 생각한다면 휴대전화기에 의해 발생하는 두부내 국소SAR의 인체영향도 두부의 온도상승과 연관된다고 추정된다. 본 논문은 휴대전화기를 실사용 상황에서 시간대별 두부의 국소부위에 대한 온도변화를 측정하였다. 그 결과 휴대전화기의 통화시작점에서 계속적인 온도상승을 보이다가 통화가 끝나는 시점에서 두부의 국소적인 온도변화는 빠르게 회복되지만 생체전신의 평균온도는 상승함을 알 수 있었다.

• 한국의류산업학회지
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• 제2권3호
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• pp.265-271
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• 2000

Heat stress results in fatigue, a decline in strength, alertness., and mental capacity. The problem is compounded when high humidity exists. To help relieve worker heat stress, many types of cooling units are marketed. While workers may experience some cooling, critical body core temperatures often continue to elevate. This study was designed to find the effects of three kinds of cooling vest with portable frozen gel strips on thermophysiological parameters and on temperature and humidity within clothing. The heart rate, rectal, and skin temperature as well as sweat rate and clothing microclimate were measured during 80 min in 5 healthy males. Inquiries were also made into the subjective rating thermal, humidity comfort, and fatigue sensations. The main findings in our experiments are as follows: (a) Physiological parameters such as rectal temperature was the lowest in garb A1, intermediate in garb A, and the highest in garb A2 throughout the experiment. And mean skin temperature was the lowest in garb A, intermediate in garb A1, and the highest in garb A2; (b) Temperature and humidity within clothing (back) were garb in Al, intermediate in garb A, and the highest in garb A2. But the temperature and humidity within clothing (chest) were garb in A, intermediate in garb A1, and the highest in garb A2; (c) Most participants (4 out of 5 persons) answered that they felt more comfortable and fatigueless in garb A1 than in garb A and A2. It is concluded that local cooling in garb A1 of the upper torso could physiological reduce the thermal strain in participants wearing cooling vest.

• 한국연소학회지
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• 제14권4호
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• pp.41-47
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• 2009

An experimental study was performed to confirm the effect of the changing combustor pressure(-30~30 kpa), combustion characteristics were investigated by measuring the local chemiluminescence intensity, the local temperature distribution and emission. In order to investigate combustion ones, the combustor pressure index($P^*$) was controlled in the range of 0.7~1.3 for each equivalence ratio in the present combustion system, where $P^*$ is defined as the ratio of absolute pressure to atmospheric one. The local mean temperature showed the uniform distributions for lower pressure index, which increased with increasing equivalence ratio. The mean $OH^*$ chemiluminescence intensity, showed high level for lower pressure index for ${\Phi}{\get}1.0$ conditions. EINOx decreased with decreasing pressure index for overall equivalence ratio conditions.

• 대한치과의사협회지
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• 제56권1호
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• pp.58-65
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• 2018

Dental local anesthesia is important procedure for the elimination of pain during dental treatment. However, the pain during local anesthesia is one of the main source of fear to the patients. The cause of pain during dental local anesthesia includes soft tissue damage during penetration of the oral mucosa, pressure from the spread of the anesthetic solution, temperature of anesthetic solution, low pH of anesthetic solution, and the characteristics of the drug. Several concepts and devices introduced to date to reduce the pain during local anesthesia for dental treatment. In this report, devices that can reduce the pain during local anesthesia will be discussed.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 추계학술대회논문집A
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• pp.61-66
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• 2001

Fracture behaviors of pipes with local wall thinning is very important for the integrity of nuclear power plant. In pipes of energy plants, sometimes, the local wall thinning may result from severe drosion-corrosion damage. However, effect of local wall thinning on strength and fracture behaviors of piping system were not well studied. In this paper, the monotonic bending tests were performed of full-scale carbon steel pipes with local wall thinning. A monotonic bending load was applied to straight pipe specimens by four-point loading at ambient temperature without internal pressure. From the tests, fracture behaviors and fracture strength of locally thinned pipe were manifested systematically. The observed failure modes were divided into four types; ovalization, ovalization+cracking, local buckling and local buckling+cracking. Also, maximum load was successfully evaluated.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.78.2-78.2
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• 2010

Effect of temperature elevation of inlet air on performance of a membrane humidifier for PEMFC vehicle application was investigated both experimentally and numerically. A shell-and-tube typed gas-to-gas humidifier with Nafion membrane was tested. The experimental result showed that water transfer varies nonlinearly with the temperature elevation. Numerical analysis based on detailed modeling is also conducted on a single tube geometry to explain this nonlinear behavior. The simulation revealed that the local water flux varies nolineary and dramatically along the tube. Analysis is based on competing role of temperature increase and relative humidity decrease, both of which seriously affect water conductivity of the membrane.

• Journal of Advanced Marine Engineering and Technology
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• 제24권3호
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• pp.13-19
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• 2000

In the present study, a program for predicting thermal performance of an air cooled condenser is illustrated. Heat transfer equations of single phase and two phase flow are formulated into the form that is convenient to incorporate the local analysis method. The resulting equations are solved by temperature and mass correction methods. Empirical equations for both side fluids are incorporated in the caculation procedures. In order to compare the calculation results, superheat temperature of steam are varied. The tube length of superheated zone, wall temperature, temperature profile along the tube and steam qualities are predicted.