• 천문학논총
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• 제16권1호
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• pp.43-47
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• 2001

We developed a CCD camera that can observe wide fields on the sky. We tested the field of views using various lenses. For cooling the CCD chip, we used a thermoelectric cooling device and tested the cooling efficiency. This camera will continuously observe a part of the sky. The data from the camera will be used to decide the current weather condition by the real-time star counting program (SCount) which will be developed later.

• Elastomers and Composites
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• 제56권4호
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• pp.250-253
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• 2021

Polypyrrole is an organic thermoelectric material which has been receiving extensive attention in recent years. Polypyrrole is applicable in various fields because its electrical properties are controllable by its doping concentration. In this study, the effects of the polypyrrole doping state on its photoresponse were investigated. The degree of doping was controlled by ammonia solution treatment. Then, the chemical structure as a function of the doping states was observed by Raman analysis. Moreover, the photocurrent and photovoltage characteristics for various doping states were measured by an asymmetrically irradiated light source. As the degree of doping increased, the electrical conductivity increased, which affected the photocurrent. Meanwhile, the photovoltage was related to the temperature gradient caused by light irradiation.

• 한국초전도ㆍ저온공학회논문지
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• 제20권2호
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• pp.24-28
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• 2018

To understand the effects of Cd substitution for Cu, $(Pb_{0.5}Cu_{0.5-x}Cd_x)Sr_2(Ca_{0.7}Y_{0.3})Cu_2O_z$ (x = 0 ~ 0.5) compounds were synthesized and the structural and superconducting properties of the compounds were characterized. Resistivity data revealed that superconducting transition temperature rises initially up to x = 0.25 and then decreases as the Cd doping content increases. Room-temperature thermoelectric power decreases at first up to x = 0.25 and then increases with higher Cd doping content, indicating that the change in $T_c$ is mainly caused by the change in the hole concentration on the superconducting planes by the Cd doping. The non-monotonic dependence of the lattice parameters and the transition temperature with Cd doping content is discussed in connection with the possible formation of $Pb^{+2}$ ions and the removal of excess oxygen caused by Cd substitution in the charge reservoir layer. A correlation between transition temperature and c/a lattice parameter ratio was observed for the $(Pb_{0.5}Cu_{0.5-x}Cd_x)Sr_2(Ca_{0.7}Y_{0.3})Cu_2O_z$ system.

• Physical Therapy Rehabilitation Science
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• 제12권3호
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• pp.310-319
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• 2023

Objective: The purpose of this study was to investigate the effects of a combination of progressive scapular stabilization exercises, neck and thoracic spine mobilization, and thermoelectric physical therapy on pain, range of motion, muscle strength, and function in patients with acute whiplash injury. Design: A randomized controlled trial design. Methods: A total of 24 subjects were included in this study. They were randomly assigned to an experimental group (n=12) that performed scapular stabilization exercises, neck and thoracic spine mobilization, and physiotherapy, and a control group (n=12) that only performed neck and thoracic spine mobilization and physiotherapy. The pre-test was conducted before the intervention and consisted of a total of 12 treatment sessions of 60 minutes each, three times a week. A posttest was conducted 4 weeks later. Pain, range of motion, muscle strength, and function were assessed before and after intervention. Results: The results of the study showed that there was a significant difference in pain reduction and range of motion and muscle strength improvement in the experimental group, and a significant difference was also found between the experimental group and the control group in terms of functional evaluation. Conclusions: The combination of exercise therapy and joint mobilization technique and physical therapy resulted in greater improvements in pain, range of motion, strength, and function assessment, contributing to improved overall function.

• 마이크로전자및패키징학회지
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• 제17권4호
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• pp.77-82
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• 2010

증착공정 및 환원분위기 열처리가 p형 Sb-Te 박막의 열전특성에 미치는 영향을 연구하였다. $Sb_2Te_3$ 잉곳을 분쇄한 분말을 증착원으로 사용하여 형성한 박막은 $2.71{\times}10^{-4}W/m-K^2$, Sb와 Te 혼합분말을 증착원으로 사용하여 형성한 박막은 $0.12{\times}10^{-4}W/m-K^2$, Sb와 Te의 동시 증착으로 제조한 박막은 $0.73{\times}10^{-4}W/m-K^2$의 출력인자를 나타내었다. $300^{\circ}C$에서 2시간 유지하는 환원분위기 열처리에 의해 $Sb_2Te_3$ 잉곳을 분쇄한 분말을 증착원으로 사용하여 형성한 박막의 출력인자가 $24.1{\times}10^{-4}W/m-K^2$로 향상되었으며, Sb와 Te의 동시증착으로 제조한 박막의 출력인자는 $40.2{\times}10^{-4}W/m-K^2$로 크게 향상되었다.

• 한국표면공학회지
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• 제38권1호
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• pp.7-13
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• 2005

Bismuth thin films were prepared on glass substrate with RF magnetron sputtering and effects of substrate temperature on surface morphology and their electrical transport properties were investigated. Grain growth of bismuth after nucleation and the onset of coalescense of grains at 393 K were observed with field emission secondary electron microscopy. Continuous thin films could not be obtained above 473 K because of grain segregation and island formation. Hall effect measurements showed that substrate heating yields the decrease of carrier density and the increase of mobility. Resistivity of bismuth film has its minimum (about 0.7 x 10/sup -3/ Ωcm) in range of 403～433 K. Annealing of bismuth films deposited at room temperature was carried out in a radiation furnace with flowing hydrogen gas. The change of resistivity was not significant due to cancellation of the decrease of carrier density and the increase of mobility. The abrupt change of electrical properties of film annealed above 523 K was found to be caused by partial oxidation of bismuth layer in x-ray diffraction analysis.

• 펄프종이기술
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• 제44권5호
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• pp.80-86
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• 2012

The disposal of the bottom ash originated from a thermoelectric power plant which used the pulverized coal, has been an important issue of the power plants. In order to find the possible way of recycling of the bottom ash, the applicability of the bottom ash as an inorganic filler for paper making was investigated in this study. The pretreatment with acid were applied for upgrading the properties of bottom ash. The effects of the addition of the bottom ash to the different pulp stocks, Sw-BKP, DIP(Deinked Pulp), Sw-UBKP were evaluated in terms of the change in paper properties. The brightness and tensile strength decreased as the increase of the amount of the bottom ash addition. The bulk and the opacity were increased by the addition of bottom ash. The pretreatment of bottom ash resulted in the increase of improvement of the brightness and the strength properties comparing with those of untreated bottom ash.

• 한국재료학회지
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• 제9권11호
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• pp.1108-1111
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• 1999

결정성장 도중 전류에 의해 고/액 계면에서 발생하는 Peltier 열을 이용하면 온도구배의 증가와 이에 따른 성장속도의 증가 및 결정성의 향상에 기여할 것이라 예상되어, 고/액 계면에서 복합적으로 발생하는 Peltier 효과를 조사하였다. 전류 밀도, 극성 및 온도구배의 변화에 따른 고상과 액상 및 그 계면에서의 온도변화로부터 이론적 추론에 의해 Peltier 열, Thomson 열 및 Joule 열만의 영향으로 분류할 수 있었고, 고상/액상 계에 대한 Peltier 계수 및 Thomson 계수도 구할 수 있었다.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 제36회 하계학술대회 논문집 B
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• pp.1711-1713
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• 2005

최근 고유가 시대에 따른 대체 에너지기술 분야에 대한 관심과 함께 저전력 소비형 전자기기의 동력원으로서 열전발전기술이 주목받고 있다. 열전발전 기술을 이용하여 산업폐열원 등에서 전력을 생산하기 위해서는 폐열원의 열적 분포특성이 우선적으로 검토, 평가되어야 한다. 그 이유는 일반적 산업폐열원의 경우 발전소자가 설치될 열원에서의 열 분포가 실험실 조건에서와 같이 일정면적에서의 균일 열량조건을 만족시키기는 어렵고 국부적 불균일 열 분포를 나타낼 가능성이 매우 높기 때문으로, 이같은 불균일 열원특성은 열전모듈의 직렬연결을 기본으로 하고 있는 열전 발전시스템의 발전능에 직접적 영향을 미치게 되기 때문이다. 따라서 불균일 열원특성에 따른 열전 발전능의 평가는 열전발전기 전체의 발전능을 평가하는 매우 중요한 인자이다. 본 연구에서는 Bi-Te계 열전발전모듈을 이용하여 열편차 조건에서의 열분포 특성 및 열전달 특성변화를 조사하고 이것에 따른 단위발전소자의 발전특성 변화를 규명 하고자 하였다.

• 마이크로전자및패키징학회지
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• 제24권2호
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• pp.61-67
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• 2017

소자의 트랜지스터 밀도가 급속히 높아짐에 따라 소자 내부에서 발생하는 열 유속(heat flux) 또한 빠르게 증가하고 있다. 소자의 고열 문제는 소자의 성능과 신뢰성 감소에 크게 영향을 미친다. 기존의 냉각방법들은 이러한 고열문제를 해결하기 위해선 한계점에 다다랐고, 그 대안으로 liquid heat pipe, thermoelectric cooler, thermal Si via, 등 여러 냉각방법이 연구되고 있다. 본 실험에서는 직선형 마이크로채널과 TSV(through Si via)를 이용한 액체 냉각시스템을 연구하였다. 두 종류의 냉매(DI water와 ethylene glycol(70 wt%))와 3 종류의 금속 범프(Ag, Cu, Cr/Au/Cu)의 영향을 분석하였으며, 대류, 복사 및 액체 냉각으로 인한 총 열 유속을 계산하여 비교하였다. 냉각 전후의 냉각시스템의 표면온도는 적외선현미경을 통해 측정하였고, 마이크로채널 내 액체 흐름은 형광현미경을 이용하여 측정하였다. 총 열 유속은 ethylene glycol(70 wt%)의 경우 가열 온도 $200^{\circ}C$에서 $2.42W/cm^2$로 나타났으며 대부분 액체 냉각 효과에 의한 결과로 확인되었다.