• Advances in Energy Research
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• 제1권2호
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• pp.127-146
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• 2013

Torrefaction technologies convert assorted biomass feedstocks into energy-concentrated, carbon neutral fuel that is economically transported and easily ground for blending with fossil coals at numerous power plants around the world without needs to retrofit. Utilization of torrefied biomass in conventional electric generating units may be an increasingly attractive alternative for electricity generation as aging power plants in the world need to be upgraded or improved. This paper examines the economic feasibility of torrefaction in different scenarios by modeling torrefaction plants producing 136,078 t/year (150,000 ton/year) biocoal from wood and corn stover. The utilization of biocoal blends in existing coal-fired power plants is modeled to determine the demand for this fuel in the context of emerging policies regulating emissions from coal in the U.S. setting. Opportunities to co-locate torrefaction facilities adjacent to corn ethanol plants and coal-fired power plants are explored as means to improve economics for collaborating businesses. Life cycle analysis was conducted in parallel to this economic study and was used to determine environmental impacts of converting biomass to biocoal for blending in coal-fired power plants as well as the use of substantial flows of off-gasses produced in the torrefaction process. Sensitivity analysis of the financial rates of return of the different businesses has been performed to measure impacts of different factors, whether input prices, output prices, or policy measures that render costs or rewards for the businesses.

• Advances in Energy Research
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• 제5권3호
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• pp.239-254
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• 2017

The world began to search for new energy sources with increasing energy demand. Renewable energy sources are as hydropower important for alternative energy. Countries with high hydroelectric potentials continue to work to utilize hydroelectric power plants in the most efficient way. Pumped storage hydropower plants are an important investment to meet the growing energy needs at peak times and to store energy. Although it produces energy in many countries, pumped storage hydropower plants have not begun to be built in Turkey which has high hydroelectric potential. A new era will be opened for energy production in Turkey where a large number of pumped storage hydropower plants projects are in study phase with the construction of pumped storage hydropower plants and first nuclear power plant.

• 동력기계공학회지
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• 제10권4호
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• pp.105-110
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• 2006

Among many other alternative energy resources, small scale hydro power has been brought into attention as a reliable source of energy today, which had been relatively neglected since 1960s. Especially, Kaplan micro-turbine can be applied to various kind of small hydro power plants, such as reservoirs for agriculture purpose, sewage treatment plants and water purification plants. However present low head of Kaplan micro-turbines and small scale hydro turbines, have limitations in the minimum required head and flow rate for efficient operation. This research is to develop modeling analysis for the Kaplan micro-turbine, which can improve economical features of small hydro power plants. The contents and scope of this research are the efficiency improvement of Kaplan micro-turbine.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.331-332
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• 2006

This paper proposes the fuel cell power plants as alternative energy sources for distributed generation in Jeju Island, Korea. This will help to increase the fuel efficiency, at least double the current thermal power plants, decrease environmental pollution, virtually to none, increase the reliability of power supply, reducing the dependency of the HVDC link, and provide quality power to the growing infrastructure in meeting the requirements for the free-trade international island.

• 농업과학연구
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• 제40권2호
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• pp.169-176
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• 2013

The price and revenue of rice are expected to decrease due to increasing rice imports, decreasing consumption and the discontinuance of the government's rice procurement. This degenerating profitability is leading to a rise in the cultivation of upland-crops such as beans, fodder crops and fruits in paddy fields. However, there is a lack of research on the selection of rice substitute crops which are adaptable to the relevant region through profitability analysis. This research, therefore, analyzed investment profitability of rice substitute crops for Cheorwon-gun area in Kangwon province. The study applied net present value (NPV) and internal rate of return (IRR), which fit for mutually exclusive investments that make one selection to the exclusion of other crops. Target crops are green house plants in Cheorwon-gun area. Financial analysis showed paprika and cucumber have investment feasibility for automated vinyl greenhouses and conventional plastic greenhouses respectively.

• 디지털산업정보학회논문지
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• 제8권4호
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• pp.193-203
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• 2012

This study analyzed regular transportation costs between port warehouses and processing plants and between processing plants and central distribution centers and further transportation costs relations according to empty transfer rates in each circulation by examining the distribution routes of imported grain including wheat, barley, corn, and soybean, namely port warehouses, processing plants, and central distribution centers. Based on the results, the study compared and reviewed the logistics transportation costs. The analysis results of the alternative model show that logistics operational costs could be considerably cut down by introducing a flexible vehicle transportation operational method, which is to change the vehicle loading parts for proper substitute transportation after unloading and transport them to other locations such as central distribution centers instead of returning empty, as an alternative to high operational costs deriving from empty vehicle operation in each circulation after unloading items in case of transportation of imported grain and processed items. The results allow for a more realistic approach to general problems with large-scale distribution network operation and provide a theoretical foundation to serve as a guide to establish policies for corporate operation of imported grain logistics systems.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1993년도 하계학술대회 논문집 A
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• pp.140-143
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• 1993

Station Blackout(SBO) event means the complete loss of alternating current(AC) electrical power to the essential & nonessential switchgear buses in a nuclear power plants. Since many safety systems in nuclear power plants depend upon alternative current power, the SBO event could be an important contributor to damage of reactor core. Therefore, the SBO events have been considered as a very important safety issues in a nuclear power plants. In this paper, as evaluating the design characteristics of offsite & emergency power systems, an acceptable minimum SBO duration is calculated. And it is presented that the design method for alternative AC(AAC) sources to cope with the SBO events.

• 한국원자력학회:학술대회논문집
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• 한국원자력학회 2002년도 추계학술발표회요약집
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• pp.205-205
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• 2002

• International Journal of Advanced Culture Technology
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• 제7권4호
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• pp.104-110
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• 2019

Since 1986, domestic sewage treatment plants have installed and operated biogas plants that produce biogas (digested gas) using food, livestock manure and sewage sludge as part of the use of alternative energy for energy independence. Despite concerns about safety accidents and risks of large-scale accidents due to the continuous expansion of biogas plants, the Ministry of Environment has managed and supervised biogas plants to be environmental plants, focusing on environmental management. There is a lack of safety awareness of workers' processes. Only recently has the process safety management (PSM) system been implemented in biogas plants, but workers' perceptions of process safety have changed. As there is a difference in the degree of safety process management and safety awareness among workers, it is necessary to establish clear and systematic safety management standards. Therefore, The purpose of this study is to examine whether the application of the plant safety management (PSM) system to biogas plants is effective for workers' safety awareness in order to ensure safe operation of biogas plants and prevent workers' safety accidents in advance.

• Journal of Crop Science and Biotechnology
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• 제11권2호
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• pp.127-134
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• 2008

Tobamoviruses are the major viral pathogens of tomato and bell pepper. The preliminary results showed that Acibenzolar-Smethyl(ASM; S-methylbenzo(1,2,3) thiadiazole-7-carbothiate) pre-treatment to tomato and tobacco plants reduces the concentration of Tomato mosaic tobamovirus(ToMV) and Tobacco mosaic tobamovirus(TMV) in tomato and bell pepper seedlings, respectively. Pre-treatment of the indicator plant(Nicotiana glutinosa) with the ASM followed by challenge inoculation with tobamoviruses produced a reduced number and size of local lesions(67 and 79% protection over control to TMV and ToMV inoculation, respectively). In order to understand the mechanism of resistance the gene expression profiles of antiviral genes was examined. RT-PCR products showed higher expression of two viral resistance genes viz., alternative oxidase(AOX) and RNA dependent RNA polymerase(RdRp) in the upper leaves of the ASM-treated tomato plants challenge inoculation with ToMV. Further, the viral concentration was also quantified in the upper leaves by reverse transcription PCR using specific primer for movement protein of ToMV, as well as ELISA by using antisera against tobamoviruses. The results provided additional evidence that ASM pre-treatment reduced the viral movement to upper leaves. The results suggest that expressions of viral resistance genes in the host are the key component in the resistance against ToMV in the inducer-treated tomato plants.