• Title/Summary/Keyword: Energy problems

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Development Trends and Perspectives of Dye-Sensitized Solar Cells (염료감응 태양전지 개발동향 및 전망)

  • Kang , Moon-Sung;Kang , Yong-Soo
    • Journal of Powder Materials
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    • v.12 no.1
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    • pp.7-16
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    • 2005
  • Dye-sensitized solar cells(DSSCs) have been under investigation for the past decade due to their attractive features such as high energy conversion efficiency and low production costs. The basis for energy conversion in the injection of electrons from a photoexcited stateof a dye sensitizer into the conduction band of the nanocrystalline $TiO_2$ semiconductor upon absorption of light. It is believed that the DSSC is one of the most promising technologies to solve the significant energy problems. In this article, the development trends and perspective of DSSCs were reviewed.

Transient Characteristics of Fuel Cell Stack at Continuous Current Discharge (일정 전류에서 연료전지의 비정상 특성)

  • Park, Chang Kwon;Jeong, Kwi Seong;Oh, Byeong Soo
    • Journal of Hydrogen and New Energy
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    • v.14 no.3
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    • pp.195-206
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    • 2003
  • Polymer electrolyte membrane fuel cells(PEMFC) are very interesting power source due to high power density, simple construction and operation at low temperature. But they have problems such as high cost, improvement of performance and effect of temperature. This problems can be approached using mathematical models which are useful tools for analysis and optimization of fuel cell performance and for heat and water management, in this paper, transient model consists of various energy terms associated with fuel cell operation using the mass and energy balance equation. And water transfer in the membrane is composed of back diffusion and electro-osmotic drag. The temperature calculated by transient model approximately agreed with the temperature measured by experiment in constant current condition.

Multiple Objective Input-Output Analysis in Energy and Environmental Planning (다목적 산업연관분석을 이용한 에너지.환경계획)

  • 강희정;차재호;유왕진
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.21 no.46
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    • pp.207-219
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    • 1998
  • Multiple Objective Programming(MOP) has been suggested for the solution of completed decision problems. Decision analysis in numerous areas, including energy and environmental planning, necessarily requires consideration of multiple conflicting objectives, MOP has been successfully applied to a number of these problems. The objective of this paper is to present a MOP process which are integrated model with the Input-Output(I-O) analysis for energy and environment planning in industrial sectors. In the model, three objectives are observed such as (1) value added (2) total energy consumption and (3) environmental impacts. Special emphasis is placed on the police implications of industrial structures.

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A Fuzzy Ligic Controller for the Swell and Shrink Problems of Nuclear Steam Generators

  • Moon, Byung-Soo;Park, Jae-Chang-;Han, Kwang-Soo
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1070-1073
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    • 1993
  • A Fuzzy Logic Controller for handing the swell/shrink problems of nuclear steam generators is designed, implemented and tested on the compact nuclear simulator at Korea Atomic Energy Research Institute. Its performance is found to be better than of the PI controller originally being used. In terms of the total variations for the control actions and for the flow error curve, the ones by the fuzzy controller are found to be less than one third of those by the PI controller.

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Recent Development for the Determination of Metabolizable Energy Values (대사에너지 측정방법에 대한 최근 연구동향)

  • 한인규;오상집;송만강
    • Korean Journal of Poultry Science
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    • v.7 no.2
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    • pp.4-17
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    • 1980
  • This is to review from the existing literatures the various methods of determination, problems involved in the determination of metabolizable energy(ME) values of poultry feedstuffs that is the most widely used energy term in poultry nutrition. An attempt will also be made to introduce the newly developed determination method of ME by Sibbald and his associates. It was found that conventional methods of ME measurements such as total collection method and indicator method require a great deal of labor and time. It should also be pointed out that these methods have some technical problems as well. Experimental evidences indicate that the ME content of feedstuffs may be affected by breed, age, substitution level of basal diet, kind of basal diet, methods of chemical analysis and chemical composition of experimental diet. Standard procedures and technical advantages of newly developed method of "True Metabolizable Energy" system are fully described.

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CASMO-3/MASTER Pin Power Benchmarking for the B&W Critical Experiments

  • Kim, Kang-Seog;Song, Jae-Seung;Zee, Sung-Quun;Kim, Yong-Rae
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05a
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    • pp.225-230
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    • 1996
  • A three-dimensional reactor core simulation code, MASTER has been developed as a part of ADONIS which is the Korean core design package in KAERI. CASMO-3 is used as a precedent lattice code for two-group microscopic cross section and heterogeneous formfunctions. The pin power reconstruction capability of CASMO-3/MASTER was evaluated for a validation and verification Five B&W critical experiments were selected as benchmark problems. These problems included two experiments for CE-type and three for WH-type fuel assemblies. Two of them contained gadolinia rods as burnable absorber. Comparison of the calculated pin power distributions with the measured ones demonstrate that CASMO-3/MASTER can predict the pin power distribution as well as CASMO-3/SIMULATE-3.

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Effect of Energy Consumptuon on Air Pollution in I.R.Iran

  • Ayati, B.;Ganjidoust, H.
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2003.11a
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    • pp.43-46
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    • 2003
  • The economy of I.R.Iran is so related to oil that has had many environmental problems especially air pollution in urban areas in recent years. Statistics show that most of the time, the condition of air quality is in crisis level especially during fall and winter seasons. Rapid and high population growth has had large amount of fossil fuels consumption in all sectors including transportation, industry, agriculture, residential and commercial and public services and air pollution and healthy problems. Iran's abundance of fossil fuel resources has tended to discourage the country's incentive to shift to cleaner alternative energy sources for its energy needs that must be considered in future programming. These are discussed in this paper.

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Energy Evaluation Studies on Pyroprocessing of Solids (고체 물질의 고온 처리 공정에 관한 에너지 평가 연구)

  • Ha, Daeseung;Choi, Sangmin
    • 한국연소학회:학술대회논문집
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    • 2014.11a
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    • pp.305-307
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    • 2014
  • Pyroprocessing (or pyrometallurgy) is the way of extracting from materials subjected to high temperatures. Generally, this process has a high energy consumption because of mass production and heating-up. To attain effective and efficient energy management, energetic analysis using 0-dimensional model is usually conducted. However, this model can lead to a misunderstanding about energy evaluation due to many assumptions and limitations. In this study, heat & mass balance using 0-dimensional model was reviewed to systematize problems and considerations in general process energy evaluation.

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Analysis of Development Situation of Korean and Foreign Street Furnitures Using Alternative Energy (대체에너지를 이용한 국·내외 가로시설물 개발 유형 분석)

  • Kim, Ja Kyung;Park, Hyung Jin
    • KIEAE Journal
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    • v.10 no.1
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    • pp.33-44
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    • 2010
  • These days, the use of alternative energy is recognized as one of countermeasures to rising oil prices and climate-change agreements. Especially, it is regarded as a main element to realize 'Low-Carbon Green Growth', one of the key policies of MB government. However, though alternative energy, renewable energy, is a main policy issue of the present administration, there are many problems to solve: the lack of recognition of its energy, the low level of its technology, its expert's shortage, and its limited application fields. Therefore, to stimulate the use of alternative energy in Korea and to change the recognition of this energy, it is needed to utilize it to urban street furniture that many people visit and use. In particular, if alternative energy is first applied to street furniture that needs energy for its management, the effect of publicity and energy saving will be so great. In this study, for the basic research to introduce and promote various alternative energy sources such as solar power, wind power, small hydro power, and human power, we analyzed the present condition of development of Korean and foreign street furniture items. Furthermore, we evaluated the level of development of these street furniture products and the design types of them and from these evaluations suggested the design direction that can solve problems in development and improve the possibility of application of these energy sources to these street furniture items. Through these analyses, this study aims to enhance the image of future environment-friendly city and make new index for the application of alternative energy.