• Title/Summary/Keyword: thermal pollution

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Method of Integrating Landsat-5 and Landsat-7 Data to Retrieve Sea Surface Temperature in Coastal Waters on the Basis of Local Empirical Algorithm

  • Xing, Qianguo;Chen, Chu-Qun;Shi, Ping
    • Ocean Science Journal
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    • v.41 no.2
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    • pp.97-104
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    • 2006
  • A useful radiance-converting method was developed to convert the Landsat-7 ETM+thermal-infrared (TIR) band's radiance ($L_{{\lambda},L7/ETM+}$) to that of Landsat-5 TM TIR ($L_{{\lambda},L5/TM+})$ as: $L_{{\lambda},L5/TM}=0.9699{\times}L_{{\lambda},L7/ETM+}+0.1074\;(R^2=1)$. In addition, based on the radiance-converting equation and the linear relation between digital number (DN) and at-satellite radiance, a DN-converting equation can be established to convert DN value of the TIR band between Landsat-5 and Landsat-7. Via this method, it is easy to integrate Landsat-5 and Landsat-7 TIR data to retrieve the sea surface temperature (SST) in coastal waters on the basis of local empirical algorithms in which the radiance or DN of Lansat-5 and 7 TIR band is usually the only input independent variable. The method was employed in a local empirical algorithm in Daya Bay, China, to detect the thermal pollution of cooling water discharge from the Daya Bay nuclear power station (DNPS). This work demonstrates that radiance conversion is an effective approach to integration of Landsat-5 and Landsat-7 data in the process of a SST retrieval which is based on local empirical algorithms.

Emission Characteristics of Diesel Oxidation Catalysts for a Commercial Diesel Engine (상용 디젤엔진용 산화촉매의 배출가스 저감 특성)

  • Choi, B.C.;Lee, C.H.;Park, H.J.;Jung, M.K.;Kwon, G.M.;Shin, B.S.;Kim, S.S.
    • Journal of Power System Engineering
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    • v.6 no.2
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    • pp.18-23
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    • 2002
  • Recently, as people pay attention to the environmental pollution, the emission of diesel engine has become a serious problem. Diesel Oxidation Catalysts(DOC) were experimentally investigated for the purification of pollutants exhaust emission from the diesel engine. In this study, the conversion efficiency of exhaust gas was investigated with various washcoat materials of the DOC. It was formed that CO conversion efficiency depended on temperature, but THC conversion was dominated by temperature and space velocity. Conversion efficiency of THC and CO increased with the addition of ZSM-5 in the washcoat, whereas these conversion efficiency decreased by adding Nd and Ba additives. $V_2O_5$ additive had the thermal stability for high temperature. Thermal durability of the catalyst was improved as increase of $V_2O_5$ additive.

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A Study on the Optimum of Closed ${CO}_{2}$ Gas Turbine Process for Nuclear Energy Power Plant(I) (원자력 발전소에 대한 밀폐 ${CO}_{2}$ 가스터빈 프로세스의 최적화 연구 I)

  • 이찬규;이종원
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.13 no.3
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    • pp.490-499
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    • 1989
  • These days the closed cycle gas turbine attracts considerable attention due to : (1) The possibility of directly coupling the closed cycle gas turbine with a high temperature gas cooled reactor ; (2) the economical use of dry coolers to reduce the thermal charge of the environment ; and (3) the reduction of pollution and energy consumption, by replacing the domestic hearth by a central heating and power station. In this paper, we selected the optimal cycle from the characteristic of thermodynamic cycle for the optimal design of closed CO$_{2}$ gas turbine cycle usuable in nuclear energy power plant. Also the effects of between the parameters and thermal efficiency were investigated by computer simulation. These results and design data will be added to basics in optimal designing closed CO$_{2}$ cycle gas turbine plant.

A Study on Manufacturing and Processes of the Lightweight Block Unit for Roof Greening with Bottom ash (옥상녹화용 경량유닛의 블록제조 공법 및 공정 연구)

  • Moon, Jong-Wook;Oh, Jung-Keun;Lee, Tae-Goo
    • KIEAE Journal
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    • v.12 no.3
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    • pp.95-100
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    • 2012
  • Thermal phenomena has caused abnormal weather phenomena due to the lack of urban green spaces To solve these problems, the country of recorded a city business is actively evolving trends. but in all the land, most built-up city's green buildings unless the demolition of the composition is an impossible situation, green space in urban areas, with emphasis on composition. In this study, thermal power plants that occured in the evolution of vegetation by utilizing Bottom Ash was tried to develop a lightweight block. Bottom Ash block to take advantage of vegetation is focused create green space in urban areas Vegetation in the block was carried out manufacturing lightweight, porous, lightweight water ratio suitable for three types of blocks selected according to its kind study on the manufacturing and process. Bottom Ash from this study at the time of disposal of coal ash generated by recycling the landfill shortages, loss of landfill costs, environmental pollution and are trying to solve the same problem at the same time.

Effect of Applying Pressure of High Pressure Diecasting Process Using Salt core (용탕단조 시 저온염코어 적용 가압력의 영향)

  • Lee, Jun-Ho;Moon, J.H.;Lee, Dock-Young
    • Journal of Korea Foundry Society
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    • v.28 no.3
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    • pp.136-140
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    • 2008
  • A new concept of salt core, a melting temperature of which is lower than the solidus temperature of cast alloy, was introduced to produced an integrated casting part having a complicated inner shape or requiring under-cut in high pressure die casting or squeeze casting process. The main goal of this study is to develop a new integrated net-shape forming technology using fusible core of lower melting temperature than that of a casting alloy. This integrated net-shape forming technology would be very successful and cost-effective for producing the integrated products having a complicated inner shape or requiring under-cut. The technology for measuring and evaluating a various property of fusible core such as a thermal conductivity and thermal expansion coefficient, melting temperature was established. Also, the work space can be cleaned without a pollution inducing products.

Study on Analysis of Buoyancy Effect in Air-heating Collector using Solar Heat (태양열을 이용한 공기가열 집열기의 부력효과 해석 연구)

  • Yang, Young-Joon
    • Journal of the Korean Society of Industry Convergence
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    • v.24 no.4_2
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    • pp.467-474
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    • 2021
  • The renewable energy is known as eco-friendly energy to reduce the use of fossil fuel and decrease the environmental pollution due to exhaust gas. Targets of solar collector in domestic are usually acquisitions of hot water and hot air. System of air-heating collector is one of the technologies for obtaining hot air in cases of especially heating room and drying agricultural product. The purpose of this study is to investigate the characteristics of thermal flow such as relative pressure, velocity, outlet temperature and buoyancy effect in air-heating collector using solar heat. The flow field of air-heating collector was simulated using ANSYS-CFX program and the behaviour of hot air was evaluated with SST turbulence model. As the results, The streamline in air-heating collector showed several circular shapes in case of condition of buoyancy. Temperature difference in cross section of outlet of air-heating collector did not almost show in cases of buoyancy and small inlet velocity. Furthermore merit of air-heating collector was not observed in cases of inlet velocities. Even though it was useful to select condition of buoyancy for obtaining high temperature, however, it was confirmed that the trade off between high temperature of room and rapid injection of hot air to room could be needed through this numerical analysis.

Tropical red alga Compsopogon caeruleus: an indicator of thermally polluted waters of Europe in the context of temperature and oxygen requirements

  • Andrzej S., Rybak;Andrzej M., Woyda-Ploszczyca
    • ALGAE
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    • v.37 no.4
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    • pp.301-316
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    • 2022
  • The red alga Compsopogon caeruleus can generally be found in tropical and subtropical waters worldwide. In addition to its natural habitats, this species may be found in waters that receive abnormally hot water, e.g., from powerhouses. To date, the presence of C. caeruleus has not been observed in thermally polluted lacustrine ecosystems in Poland, which has a moderate climate. The thalli of this red alga were found growing on Vallisneria spiralis in Lichenskie Lake. Importantly, this paper presents a previously unknown relationship between the temperature (20, 25, 30, 35, and 40℃) and oxygen requirements of C. caeruleus (based on ex situ measurements of O2 consumption by thalli). Surprisingly, 35℃ can be the optimum temperature for C. caeruleus, and this temperature is higher than the values reported by some previous thermal analyses by approximately 10℃. Additionally, we reviewed and mapped the distribution of this nonnative and mesophilic red alga in natural / seminatural water ecosystems in Europe. Finally, we propose that the occurrence of C. caeruleus mature thalli can be a novel, simple and easy-to-recognize bioindicator of artificially and permanently heated waters in moderate climate zones by a regular discharge of postindustrial water.

A study on the development of drainage system for rapid drainage of thermal power plant outdoor coal storage during rainfall and characteristics of discharged water quality (강우시 화력발전소 옥외저탄장 신속한 배수를 위한 배수시스템 개발 및 배출 수질 특성에 관한 연구)

  • Lim, Chang-Min;Kwon, Hyun-Woo;Kim, Young-Min;Cho, Do-Young;Lee, Gun-Cheol
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2022.11a
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    • pp.189-190
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    • 2022
  • Power plants that produce electricity through thermal power plants mainly store coal in outdoor storage yards. In particular, coal is directly exposed to rainwater during rainfall, including torrential rain. There is no separate drainage facility in the outdoor coal yard, and coal is simply stored on the ground. Accordingly, during rainfall, coal dust flows down by rainwater, and a large amount of rainwater that is not drained overflows the outdoor coal yard, overflowing the surrounding facilities and causing environmental pollution. Therefore, in this study, a drainage system was developed for the rapid drainage of an outdoor coal mine, and the quality of the water was evaluated when rainwater mixed with drainage characteristics and coal dust was discharged through the drainage system.

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Application of the Latest Land Use Data for Numerical Simulation of Urban Thermal Environment in the Daegu (최신토지피복자료를 이용한 대구시의 열환경 수치모의)

  • Lee, Hyun-Ju;Lee, Kwi-Ok;Won, Gyeong-Mee;Lee, Hwa-Woon
    • Journal of Korean Society for Atmospheric Environment
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    • v.25 no.3
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    • pp.196-210
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    • 2009
  • The land surface precesses is very important to predict urban meteorological conditions. Thus, the latest land use data set to reflect the rapid progress in urbanization was applied to simulate urban thermal environment in Daegu. Because use of the U.S geological Survey (USGS) 25-category data, currently in the fifth-generation Pennsylvania State University-National Center for Atmospheric Research Mesoscale Model (MM5), does not accurately described the heterogeneity of urban surface, we replaced the land use data in USGS with the latest land-use data of the Korea Ministry of Environment over Daegu. The single urban category in existing 24-category U.S. Geological survey land cover classification used in MM5 was divided into 5 classes to account for heterogeneity of urban land cover. The new land cover classification (MC-LULC) improved the capability of MM5 to simulate the daytime part of the diurnal temperature cycle in the urban area. The 'MC-LULC' simulation produced the observed temperature field reasonably well, including spatial characteristics. The warm cores in western Daegu is characterized by an industrial area.

A STUDY ON EXTRACTING THE SURFACE TEMPERATURE USING THERMAL INFRARED OF ASTER IMAGES IN URBAN AREA

  • Jo Myung-Hee;Kim Hyung-Sub;Kim Sung-Jae;Yu Seong-Ok
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.717-720
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    • 2005
  • Recently as large sized urban development and the city ward drifting of population are caused, the urban surface temperature is raised very seriously and rapidly. These artificial developments have destroyed the inner and outer landscapes such as topography and have changed complex local climate such as a sudden rise in temperature, the change of wind field and air pollution. In order to clarify this problem visually, the studies on extracting the thermal infrared and the characteristic analysis of local climate in urban area had been performed by using the sixth band of Landsat TM and ETM+. However, there is a need to alternate Landsat TM and ETM+ because these satellite images are not applied any more. Therefore, in this paper it is proposed to use 2 Aster image (2004.4.17 daily 2b03, 2004.10.10 night 2b03) of EOS AM and to extract the surface temperature. Also, the pattern of surface temperature in urban area and the application possibility in local climate study are proposed by verifying the correlation with A WS data. Also, IKONOS image was used to figure out the artificial development area in visual.

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