• Korean Journal of Agricultural Science
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• v.38 no.2
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• pp.349-360
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• 2011

The international oil price have being fluctuated due to the exhaustion of fossil energy problem became big social issue. Rural villages are relatively sensitive to the energy problem, reflecting the characteristics of rural sustainable and stable introduction of renewable energy sources that are available is essential. In addition, through the influx of young workers in rural areas to regain vitality, efforts to improve rural living environment has been under the rural newtown project. In this study, a survey aimed at rural dwellers through the AHP, interview to report of realization about renewable energy and review the current policies. The results of realization survey though AHP are as follows, (1) the advantage of the natural environment (2) the superiority of government supporting policy and being economic, (3) easy to use, (4) ecologically stable, and (5) policy stable, respectively. In addition, renewable energy sources among the inhabitants of rural areas by solar energy was the highest score. The impact of regional characteristics compared with other energy sources receive little, easy to apply and has already been considerable technological development is considered.

• New & Renewable Energy
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• v.7 no.2
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• pp.10-17
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• 2011

Korea is the 11th largest energy consumption country and 96% of its total energy consumption depends on imports from overseas. Therefore it is a very important task to secure renewable energy sources which can reduce both the carbon-dioxide emission and dependency on overseas energy imports. Among the various renewable energy sources, organic wastes are important sources. In Korea, 113 million toe of methane is generated from organic wastes annually, but only 3.7% is effectively used for energy conversion. Thus, it is very important to make better use of organic wastes, especially for power generation. The goals of this project are to develope the fuel supplying system of Bio Gasturbine (GT) for 5MW-class co-generation system. The fuel supplying system mainly consists of $H_2S$ removal system, Bio Gas compression system, Siloxane removal system and moisture separating systems. The fuel requirement of 5MW-class GT is at around 60% of $CH_4$, $H_2S$ (<30 ppm), Siloxane(<10 mg/$nm^3$) and supply pressure (> 25 bar) from biogas compressor. Main mechnical charateristics of Bio Gasturbine system have the specific performance; 1) high speed turbine speed (12,840 rpm) 2) very clean emmission NOx (<50 ppm) 3) high efficiency of energy conversion rate. This paper focuses on the development of design technology for food waste biogas pretreatment system for 5MW-class biogas turbine. The study also has the plan to replace the fuel of gas turbine and other distributed power systems. As the increase of bioenergy, this system help to contribute to spread more New & Renewable Energy and the establishment of Renewable Portfolio Standards (RPS) for Korea.

• ALGAE
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• v.31 no.3
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• pp.257-266
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• 2016

Nitrogen is one of the most critical nutrients affecting cell growth and biochemical composition of microalgae, ultimately determining the lipid or carbohydrate productivity for biofuels. In order to investigate the effect of nitrogen sources on the cell growth and biochemical composition of the marine microalga Tetraselmis sp., nine different N sources, including NaNO₃, KNO₃, NH₄NO₃, NH₄HCO₃, NH₄Cl, CH₃COONH₄, urea, glycine, and yeast extract were compared at the given concentration of 8.82 mM. Higher biomass concentration was achieved under organic nitrogen sources, such as yeast extract (2.23 g L⁻¹) and glycine (1.62 g L⁻¹), compared to nitrate- (1.45 g L⁻¹) or ammonium-N (0.98 g L⁻¹). All ammonium sources showed an inhibition of cell growth, but accumulated higher lipids, showing a maximum content of 28.3% in ammonium bicarbonate. When Tetraselmis sp. was cultivated using yeast extract, the highest lipid productivity of 36.0 mg L⁻¹ d⁻¹ was achieved, followed by glycine 21.5 mg L⁻¹ d⁻¹ and nitrate 19.9 mg L⁻¹ d⁻¹. Ammonium bicarbonate resulted in the lowest lipid productivity of 14.4 mg L⁻¹ d⁻¹. The major fatty acids in Tetraselmis sp. were palmitic, oleic, linoleic and linolenic acids, regardless of the nutritional compositions, indicating the suitability of this species for biodiesel production.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.10a
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• pp.893-894
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• 2005

• Asia-Pacific Journal of Business
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• v.10 no.1
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• pp.87-103
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• 2019

In December 2017, the Moon Jae-in administration announced a major policy shift away from nuclear and coal, committing itself to the vision of creating a society where renewable sources account for 20% of its electricity generation by 2030. This energy transition involves not just a technical transition from conventional energy sources to renewable energy but also active participation of multiple stakeholders in the energy governance. While energy policy making has long been dominated by the central government in Korea with the aim of managing the supply for rapid industrialization and economic growth, the Moon administration aims to diffuse the central government's authority across various actors in society. Among those actors, this study focuses on the roles that local governments play in energy transition. Despite deepening local autonomy since 1995, Korean local governments have remained policy targets or recipients in the energy policy domain. This article discusses how such a traditional role has evolved under the new administration's energy transition policy and examines what challenges and limitations local governments face in creating a more decentralized energy governance system.

• Journal of Astronomy and Space Sciences
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• v.5 no.2
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• pp.143-158
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• 1988

Since the successful observation by Uhuru, the first astronomical satellite, X-ray astronomy has become one of the rapidly developing fields in astronomy. The scientific results provide us the unique opportunity to understand the high energy nature of X-ray sources. We now know that our galaxy contains many different types of X-ray sources such as the compact X-ray sources, galactic bulge sources in addition to the Sun, the brightest X-ray sources in the sky. In this study we review the general properties of galactic X-ray sources, the characteristics of periodic compact X-ray sources, and bursters as well as the models.

• Proceedings of the Korean Nuclear Society Conference
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• 1977.06a
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• pp.109.5-110
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• 1977

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.3 no.3
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• pp.213-220
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• 1974

• Journal of the Korean Solar Energy Society
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• v.36 no.6
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• pp.13-24
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• 2016

The government introduced a mandatory installation system of new & renewable energy for public building to meet the target of greenhouse gas reduction and also suggest a correction factor for new renewable energy to expand the installation of various new & renewable energy systems. The introduction of correction factors, however, was followed by the reduction of installation size of new & renewable energy sources. Assuming that it was caused by a correction factor for each new renewable energy source calculated by the initial costs, this study proposed a new correction factor approach based on payback periods to reflect the technology element in the calculation process of correction factors additionally. The application results of new correction factors show that it was possible to do complex calculations including the economic and technological aspects to select a new & renewable energy system and that the installation size was also enlarged.

• Explosives and Blasting
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• v.27 no.2
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• pp.56-60
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• 2009

In view of physics, energy is defined as the ability to work. The use of natural gas and nuclear power have been increased since 1980s to replace fossil fuels such as coal and petroleum. Recently, solar energy, wind power, tidal power, and geothermal energy have been considered as promising alternative energy sources to overcome environmental pollution. However, their energy efficiencies are much lower than those of chemical energies such as nuclear power, explosive, and petroleum gas. In this study, the present situation of the green energy was reviewed to seek out the way to overcome the limit of the environmental (alternative) energy. Also, purification, application and development trend of the highly efficient alternative energy sources were investigated.