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        검색결과 55

        42.
        2011.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 석모도 지역의 지열에너지 개발에 중요한 심부 파쇄대 시스템에 대한 보다 광범위하고 정밀한 조사를 위하여 2005-2006년에 수행되었던 44 측점의 탐사 영역을 확대하여 추가로 36 측점에서 자기지전류 및 가청주파수 자기지전류 심부물리탐사 현장 탐사 자료를 획득하였다. 이전의 자료와 함께 모든 자료는 격자상으로 분포하도록 설계하여 관심 영역 내에서 2차원 및 3차원 역산을 통하여 지질 구조 해석을 실시하였다. 역산 해석 결과 지열수가 발견된 시추공 주변으로 파쇄대로 추정되는 최소 2 조의 큰 전기비저항 불연속면을 영상화하였는데, NNE-SWW(북북동-남서) 방향으로 발달한 불연속대는 지열수가 발견된 시추공 방향으로 발달되어있고, 이와 함께 인접한 바다로부터 EW(동-서) 방향으로 불연속면이 발달되어 있음을 볼 수 있었다.
        4,200원
        43.
        2004.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        Twenty three samples of man-made mineral fibers (MMMF) were collected and analyzed for their mineral contents using a transmission electron microscope equipped with energy dispersive X-ray analyzer (TEM-EDX). Five glass fibers showed a straight fiber type without branches with average diameter ranged from 2.6㎛ to 5.6㎛ and average length 12.2∼29.6㎛. The major atomic compositions of the glass fibers were Na, Mg, Si, Ca, and Fe with a little variance among them and contained trace amounts of Al and Si. Eleven rock wool fibers also showed a straight fiber type without branches. The rock wool fibers used in 3 insulation panel and 1 insulation tube had average diameter 13.6∼26.4㎛ and average length 13.6∼26.4㎛. The major atomic compositions of the rock wool fibers were Na, Mg, Al, Si, S, Ca, Fe, and Cu with a little variance among them. Two of rock wool sealant fibers and one of coating material fibers had average 0.8∼ 2.2㎛ diameter and 9.9∼16.2㎛ average length. The major atomic compositions of the fibers were Mg, Al, Si, Ca, and Fe with a little variance among them and contained trace amount of S. The fibers in the rock wool coating materials contaminated partially with another type of fibers. Four of rock wool ceiling board showed 0.9∼2.04㎛ average diameter and 4.3∼15.2㎛ average length. The major atomic compositions of the fibers were Mg, Al, Si, S, Ca, and Fe with a little variance among them and contained trace amounts of Na, K, and Ti. Three of long glass fibers showed a mass appearance with finely splitted fibers, and the major atomic compositions of the fibers were Na, Mg, Al, Si, S, Ca, and Fe with no variance among them. One type of ceramic fiber showed 2.9±1.59㎛ average diameter and 20.3±9.38㎛ average length. The major compositions of the fibers were Al, Si, and S. A gypsum board and a perlite and a calcium silicate insulation material all showed aspect ratio less than 3:1, indicating non-fibrous materials. The major compositions of the gypsum board particles were Al, Si, S, K, Ca, and Fe, The perlite particles were consisted of Na, Al, Si, S, K, Ca, and Fe, and the calcium silicate insulation materials were mainly consisted of Al, Si, Ca, and Fe.
        4,900원
        44.
        2004.12 KCI 등재후보 구독 인증기관 무료, 개인회원 유료
        140 buildings of Korean major cities were investigated for the presence of asbestos and man made mineral fibers (MMMF) in their construction materials. 73 (52%) and 84 (60%) buildings contained asbestos and MMMF in their construction materials, respectively, and 17 (12%) buildings contained both asbestos and MMMF. 75% of the asbestos containing buildings were mostly constructed during 1970's. 100% of underground shopping arcades, 90% of manufacturing workplaces, 84% of train and bus terminals had the asbestos containing construction materials. The manufacturing workplaces of Daejeon (89%) and Daegu (89%), which mostly had been built in the past, used asbestos containing building materials, while the building in Seoul, Busan and Jinju, which were constructed recently, used relatively lower asbestos containing building materials with 46%, 28%, and 33%, respectively. 9 building materials that have been widely used in Korea were analyzed using a transmission electron microscope equipped with energy dispersive X-ray analyzer (TEM-EDX) for their mineral contents. All asbestos fibers showed typical characteristics of chrysotile fibers with hollow tube structure. The average diameter ranged from 0.03㎛ to 0.05㎛, and the average length were ranged from 7.5㎛ to 12.0㎛. Atomic percentages of asbestos fibers were 51.9∼55.9% of Mg, 41.3∼44.3% for Si, and 2.7∼4.8% for Fe.
        4,000원
        45.
        2007.12 KCI 등재 서비스 종료(열람 제한)
        In this study, the potential of a newly developed simulation toolkit, GATE for the simulation of electronic portal imaging devices (EPID) in radiation therapy was evaluated by characterizing the performance of the metal plate/phosphor screen detector for EPID. We compared the performances of the GATE simulator against MCNP4B code and experimental data obtained with the EPID system in order to validate its use for radiation therapy.
        46.
        2006.05 KCI 등재 서비스 종료(열람 제한)
        The increase in environmental loads and energy consumptions has resulted in the need of developed new forms of energy for a sustainable use for the society. Recently, the viability of using unused energy has attracted a great deal of attention. From the view point of using unused energy, the most critical problem can be referred to as the distance between the heat source/sink and heat demand area. The water resource in the city water system was used to solve this distance problem with unused energy. The calculation method of the potential use unit was used to survey the potential of the water resource in the city water system. The amount of theoretical unused energy and energy savings in the model city were estimated using this method. It is estimated that the amounts of energy savings and CO2 reduction correspond to 131.3 GWh and 29280[t-C], respectively, per annual basis.
        47.
        2005.02 KCI 등재 서비스 종료(열람 제한)
        Draft is defined as an unwanted local cooling of the human body caused by air movement. It is a serious problem in many ventilated or air conditioned buildings. Often draft complaints occur although measured velocities in the occupied zone maybe lower than prescribed in existing standards. Purpose of this study is to clarify the evaluation of thermal comfort based on temperature and air velocity in winter. Experiments were performed in an environmental chamber in winter. Indoor temperature and air velocity was artificially controlled. The experiments were performed to evaluate temperature conditions and air velocity conditions by physiological and psychological responses of human. According to physiological responses and psychological responses, it was clear that the optimum air velocity is about 0.15 m/s and 0.30 m/s.
        48.
        2003.09 KCI 등재 서비스 종료(열람 제한)
        When the city water was heated for the optimum use of unused energy, the energy flows and losses were calculated and evaluated to improve the value of heated water systems at dwelling side. To obtain this purpose, It was simulated on heat flows under two conditions like with heat pumps or not and calculated the energy savings. Furthermore, recycling water system was suggested for enhancing the value of heated water system. From this results, the energy flows without heat pumps showed that it was 3-4 percents of heat losses from pipes, 62 percents of energy savings from hot water uses and 34 percents of unutilized heat. When the heated water system adopt the recycling water system at dwelling side, it was improved 12 percents of total energy savings.
        49.
        2003.06 KCI 등재 서비스 종료(열람 제한)
        In order to make use of the protection effect against wind by the vegetation, it examined whether it should make what vegetation form and arrangement using the 2-dimensional non-hydrostatic model. When the foliage shielding factor increases, it becomes hard to take in protection effect against wind in a residential section. When it makes height of vegetation high, it becomes hard to take in protection effect against wind with height. In the comparison in the case where vegetation high is gradually made low toward wind-stream from a vegetation, and the case of making it low gradually, although former tends to receive the protection effect against wind by the vegetation, attenuation of wind velicity becomes large. In the comparison in the case where foliage shielding factor and distribution of density of leaf are gathered gradually toward wind-stream from a vegetation. It has been understood to evaluate to height the influence that the vegetation multi-layer model by which the heat revenue and expenditure in the direction of the vegetation height is considered is used, and to characterize the vegetation group by the parameter setting.
        50.
        2003.06 KCI 등재 서비스 종료(열람 제한)
        The research on potential energy was conducted to conserve the high-exergy energy like primary energy and utilize waste heat from sewage. From the point of view in using the waste heat, the energy potential of waste water from the model house was simulated. From the results,when the heated water was supplied to the model house side in order to put unused energy to practice use, heated water had higher energy potential than unheated water, which was due to the discharge of most of unused energy. The possessing heat capacity of sewage from heated water was increased to 40-70 percents in comparison with that from the unheated water. Therefore, it can be used as energy source for improving coefficient of performance of heat pumps. By adopting the multiple heat pump into a model house, It showed that the possessing heat capacity of sewage was reduced. It was also found that the heat was recovered as energy source for multiple heat pump in a model house.
        51.
        2003.04 KCI 등재 서비스 종료(열람 제한)
        How to plan the energy system is one of the keys for constructing the Environment -Friendly City. For this reason, a great number of surveys for utilizing unused energy have conducted by a planner. In regard to unused energy, the heat from incineration plants classify as a unused energy having high-exergy-energy. From this point of view, It is studied about the plant systems providing heat to district heating & cooling(D.H.C) and producing electric power. It is divided four system models as system I (10K [kgf/cm2] vapor as outlet of boiler, supply for 10K vapor and return to 60℃ as supply condition of district heating), system Ⅱ (30 K vapor as outlet of boiler, supply for 5K vapor and return to 60℃ as supply condition of district heating), system Ⅲ (30 K vapor as outlet of boiler, supply for 85℃ hot water and return to 60℃ as supply condition of district heating), system Ⅳ (30 K vapor as outlet of boiler, supply for 47℃ hot water and return to 40℃ as supply condition of district heating). The results from the upper condition of four system, System Ⅱ got a proper on economical benefits and system Ⅳ calculated as benefiting on energy saving effects, and suggest indifference curve as the total evaluation method of both economical benefits and energy saving.
        52.
        2003.03 KCI 등재 서비스 종료(열람 제한)
        Ecological society and energy conservative systems has become a subject of world wide attention. To examine the technologies of such systems as resource recycling society, this study is proposed for using rainwater as energy source and water resources in urban area. Useful informations for planning of utilizing rainfall as energy source, water resources, emergency water and controlling flood are discussed with model systems in urban area. It is calculated that the rate of utilizing rainwater, amounts of utilizing rainwater, substitution rate of supply water, amounts of overflow rainwater according to rain storage tank volume. By applying the past weather data, The optimum volume of rain water storage was calculated as 200m3 which mean no benefits according to the increase of storage tank volumes. For optimum planing and control method at the model system, several running method of rainwater storage tank was calculated. The optimum operating method was the using weather data as 3hours weather forecast.
        53.
        2000.10 KCI 등재 서비스 종료(열람 제한)
        Numerical simulation model using nesting method and considering topographic features was developed to predict atmospheric environments, atmospheric flow, temperature and diffusion of air pollutants in Kwangyang bay where having complex areas of point sources, Korea. In addition, developed simulation model was used tracing of spreading range of pollutants when a gas leaks suddenly from Yeo-cheon industrial complex. By comparing the measured and calculated data on atmospheric flow, temperature and diffusion of air pollutants, the results showed that this model can be well applied and complicated topography affected the diffusion of air pollutants.
        54.
        1999.08 KCI 등재 서비스 종료(열람 제한)
        This study was performed to investigate the fluid flow characteristics, the temperature distribution, humidity and PMV(Predicted Mean Vote of thermal sensation) distributions of the 3-dimensional room with side wall exhaust. The finite volume method and turbulence k-ε models with the SIMPLE computational algorithm are used. As the results of the three dimensional simulations, the region of exceeding Y=1.5m was high temperature and humidity. The inlet velocity and temperature were influenced to the floor strongly, and the room PMV was about -1.0 except the inlets.
        55.
        1999.04 KCI 등재 서비스 종료(열람 제한)
        This study was conducted to evaluate the treatment efficiency including reaction kinetics and hydraulic characteristics of food processing wastewater by using an ejector-type aeration system (ETAS) in activated sludge process. The oxygen transfer efficiency in ETAS can be changed in accordance with the depth of reactor. However, the optimum air velocity was found less than 1.82 m/hr at a superficial liquid velocity of 634 m/hr. The ETAS process showed higher organic material removal efficiency than that of the existing activated sludge process under hydraulic detention time ranged from 6 to 12 hours. This process, which can maintain MLVSS highly, is able to have high organic material removal efficiency at short HRT and deal with variable organic material loading.
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