• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.205-208
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• 2005

This research is aimed at the development of a software that predicts the surface temperature profiles of three-dimensional objects on the ground considering the spectral solar radiation through the atmosphere. The thermal modelling is essential for identifying the objects on the scenes obtained from the satellites. And the temperature distribution on the objects is necessary to obtain their infrared images in contrast to the background. We developed a software that could be used to model the thermal problems of the ground objects irradiated by the spectral solar radiation. This software can be used to handle the conduction within the object as a one-dimensional mode into the depth or as a three-dimensional mode through the media. LOWTRAN7 is used to model the spectral solar radiation including the direct and diffuse solar radiances. In this paper, temperature distributions on the objects obtained by using the one-dimensional and the three-dimensional thermal models are compared with each other to examine the applicability of the relatively easy-to-apply one-dimensional model.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.195.1-195.1
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• 2011

This paper presents an experimental study on a new potential geothermal energy source obtained from tunnel structures. An "energy textile", which is a textile-type ground heat exchanger, was fabricated between a shotcrete layer and a guided drainage geotextile in the tunnel lining system. To examine the long-term thermal behavior of the energy textile, the difference in temperatures of the inlet and outlet fluid circulating through the heat exchange pipe within the energy textile was monitored using a constant-temperature water bath. Daily heat exchange rate of the energy textile during cooling operation was estimated from the measured temperatures of the inlet and outlet fluid through the energy textile. The air and ground temperature was also continuously monitored. The operation of the energy textile as a ground heat exchanger was simulated using a 3D numerical CFD model (Fluent). The thermal conductivity of shotcrete and concrete lining components and temperature variation of air in the tunnel were incorporated in the model. The numerical analysis shows a good agreement with the long-term monitoring result.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1071-1075
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• 2003

In a closed square cavity filled with a liquid, a cooled the upper horizontal wail and a heated the lower horizontal wall, the flow isn't generated under the ground-based condition when Rayleigh number is lower than 1700. In such case the flow phenomena near an air bubble under a cooled horizontal wall were investigated. The temperature and the flow fields were studied by using the Thermo-sensitive Liquid-Crystal and the image processing. The qualitative analysis for the temperature and the flow fields were carried out by applying the image processing technique to the original data. Injecting bubble at the center point of upper cooled wall, the symmetry shape of two vortexes near an air bubble was observed. The bubble size increased, the size of velocity and the magnitude of velocity increased. In spite of elapsed time, a pair of two vortexes was the unique and steady-state flow in a square cavity and wasn't induce to the other flow in the surround region.

• Bulletin of the Korean Chemical Society
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• 제25권8호
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• pp.1217-1224
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• 2004

We have calculated the probability of HBr formation and energy disposal of the reaction exothermicity in HBr produced from the reaction of gas-phase bromine with highly covered chemisorbed hydrogen atoms on a Si (001)-(2 ${\times}$1) surface. The reaction probability is about 0.20 at gas temperature 1500 K and surface temperature 300 K. Raising the initial vibrational state of the adsorbate(H)-surface(Si) bond from the ground to v = 1, 2 and 3 states causes the vibrational, translational and rotational energies of the product HBr to increase equally. However, the vibrational and translational motions of product HBr share most of the reaction energy. Vibrational population of the HBr molecules produced from the ground state adsorbate-surface bond ($v_{HSi}$ =0) follows the Boltzmann distribution, but it deviates seriously from the Boltzmann distribution when the initial vibrational energy of the adsorbate-surface bond increases. When the vibration of the adsorbate-surface bond is in the ground state, the amount of energy dissipated into the surface is negative, while it becomes positive as vHSi increases. The energy distributions among the various modes weakly depends on surface temperature in the range of 0-600 K, regardless of the initial vibrational state of H(ad)-Si(s) bond.

• 설비공학논문집
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• 제17권1호
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• pp.71-81
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• 2005

The main objective of the present study is to investigate the performance characteristics of a ground-source heat pump(GSHP) system with a 130 m vertical and 62 mm nominal diameter U-tube ground heat exchanger. In order to evaluate the performance analysis, the ground-source heat pump connected to a test room with $90\;m^2$ floor area in the Korea Institute of Construction $Technology(37^{\circ}39'N,\;126^{\circ}48'E)$ was designed and constructed. This ground-source heat pump system mainly consisted of ground heat exchanger, indoor heat pumps and measuring devices. The cooling and heating loads of the test room were 5.5 and 7.2 kW at design conditions, respectively. The experimental results were obtained from July 2, 2003 to July 1, 2004. The cooling and heating performance coefficients of the system were determined from the measured data. The average cooling and heating COPs for the system were obtained to be 4.90 and 3.96, respectively. The temperature variations in ground and the ground heat exchanger pipe surface at different depths were also measured.

• Weed & Turfgrass Science
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• 제4권1호
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• pp.71-75
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• 2015

운동장은 체육활동 공간으로 학생은 물론 일반인들도 자주 이용하는 시설로서 다양한 피복소재들을 사용하고 있다. 본 연구에서는 동일한 운동장에 다양한 피복소재들이 적용되어 있는 경북대학교 상주캠퍼스의 대운동장에서 피복 소재별(나지, 들잔디 식재지, 우레탄 트랙, 콘크리트 바닥면, 에폭시 바닥 처리, 인조잔디)에 따른 표면온도를 비교하고자 수행하였다. 조사는 한국잔디의 녹화시기를 고려하여 5월부터 10월까지 지표면 온도와 지상부 1 m높이의 온도를 측정하였는데 각각 9시, 12시, 15시, 18시에 측정하였다. 지표면 온도는 피복소재 별과 조사 시간대별로 차이를 보였는데 나지와 천연잔디에서는 전체 조사 시간대에서 가장 낮은 온도를 나타내었다. 온도가 높은 지역은 조사시간대별에 따라 차이를 보여 우레탄 트랙과 인조잔디에서는 12시와 15시 조사에서 온도가 가장 높았고, 콘크리트와 에폭시 바닥면에서는 18시 조사에서 가장 높은 온도를 보였다. 지상 1 m 높이의 온도는 조사지역별 온도의 차이는 지표면에 비하여 현저히 적었으나 18시 조사를 제외하고, 모든 조사 시간대에서 인조잔디 지역의 온도가 가장 높게 나타났다. 따라서 운동장에 들잔디와 같은 난지형 천연잔디도 지표면과 지상부 온도 상승 억제 효과가 있어 운동 경기자의 경기력 향상에 기여할 것으로 생각된다.

• 한국수산과학회지
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• 제37권1호
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• pp.65-72
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• 2004

Fish catch by a set net in Hamdeuk fishing ground off Jeju Island were studied to determine seasonal variation of species composition and catch from 1998 to 2000. A total 72,022.9 kg was caught during the survey period, including Scomber japonicus and Trachurus japonicus of $76.4\%$ in the total. The other dominant species were Siganus fuscescens, Loligo chinesis, Seriola dumerili, Sepioteuthis lessoniana, Sardinops melanostictus, and Seriola lalandi accounting to $20.0\%$ of the total. The fishing period conducted by a set net in Hamdeuk fishing ground were from May to November. The catch by a set net were higher in summer than in spring and autumn and closely related with the seasonal variation of sea water temperature. The catch was higher in 1998 than In 1999 and 2000, which was related to the sea water temperature in fishing ground.

• 한국환경보건학회지
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• 제1권1호
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• pp.41-45
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• 1974

A study was carried out to determine the content of Mn and Cr in the ground water in Seoul area, where municipal water supply system was not installed, from Nov. 1 to Nov. 30, 1973. In this study, authors examined the hardness, pH, water temperature and Cl ion to investigate the general conditions of the ground water. For this study, samples were collected from 46 wells which were located in outpart of Seoul city, and Mn and Cr were determined with the Spectronic-20. The following results were obtained: 1) Average value of the ground water conditions of the wells were 13.3$\circ$C in temperature, pH 6.3, hardness 159 ppm and Cl ion 41 ppm. 2) In the manganese concentration, the highest area was Yeongdeungpo-Ku(0.318 ppm), while the lowest area was Sungbuk-Ku(0.065 ppm) and the mean concentration of the whole district was 0.196 ppm. 3) In the chrome concentration, the highest area was Yeongdeungpo-Ku(0.031 ppm), while the lowest area was Dobong-Ku (trace) and the mean concentration of the whole district was 0.012 ppm.

• 한국지열·수열에너지학회논문집
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• 제10권2호
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• pp.13-18
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• 2014

This paper proposes an optimum pipe material (PVC vs. PE) design & selection for open loop ground heat exchangers. Heat exchange efficiency and/or workability, and the need for trench insulation were investigated by comparing EWT (cooling mode) of each system. CFD simulations for the PVC and PE pipe with the same inner diameter show similar EWT. This is because the PVC pipe has a small thickness but a low thermal conductivity as compared to the PE pipe, and thus these two properties tend to offset each other. However, a hypothetically insulated pipe led to a meaningful drop of EWT. This means pipe insulation is of importance in performance of ground heat exchangers. From analyzing climate data and system operation, it is not advantageous to insulate trench pipes due to construction difficulties and ground temperature characteristics that are seasonally varied.

• 설비공학논문집
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• 제16권12호
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• pp.1175-1182
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• 2004

Installations of vertical boreholes for the ground source heat pump system are expensive to install. One way to reduce the initial cost is to increase the specific heat extraction rate of borehole system. However, as the specific heat extraction rate increases the temperature of borehole fluid decreases with the resultant lower Coefficient Of Performance in Heating(COPH) of heat pump system. The purpose of this study is to provide the basic informations about the performance of heat pump system with the specific heat extraction rate and soil thermal properties such as thermal conductivity and temperature. It is shown that the specific heat extraction rate is the most important parameter for the ground source heat pump system. To obtain the reasonable COPH value (COPH > 3) the heat extraction rate should be about 25 W/m or less. Accurate measurements of soil thermal properties are also very important to design the system properly. The effects of borehole thermal resistances are also examined in this study.