• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.216-219
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• 2011

신.재생에너지는 머지않아 고갈될 것이라 예측하고 있는 화석에너지의 대체에너지로서 대형 홍수와 국지적 집중호우, 가뭄과 전염병, 기근 등 우리인류의 생존을 위협하는 재앙을 어느 정도 줄일 수 있고, 온실효과 가스를 저감하고자 하는 하나의 방법으로서 가스배출량이 적은 수력, 풍력, 태양광 등의 재생에너지를 이용한 방법이다. 이 중 물은 무한적인 자원이 아니기 때문에 소중히 여기고 순환과정을 통하여 재활용 될 수 있고, 친환경적이고 장기적인 수명과 다른 자원을 사용하는 발전소들보다 더 효율적이며 복원 가능성이 크고 다른 오염유발 에너지 자원을 대신한다. 본 연구에서는 경상북도 북부지역 5개 지점의 소수력발전 후보지점에 대한 평 갈수기 및 홍수기의 유량측정에서 수위-유량관계곡선식의 유도등의 목적을 달성하기 위하여 2009년 3월부터 2010년 9월까지 5개 지점을 대상으로 현지조사 및 자료수집, 측량작업, 유량측정 등을 실시하였다. 본 유량측정을 통하여 경상북도 북부지역의 최적 소수력 발전지점 선정을 위한 기초자료를 제공할 수 있을 것으로 판단된다.

• Journal of the Korean Wood Science and Technology
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• v.25 no.1
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• pp.56-64
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• 1997

Since there are three hydroxyl groups on each anhydroglucose ring of the cellulose, the renewable resources, we can get various functional papers by the chemical modification of cellulose. The reaction involving the introduction of the ${\beta}$-cyanoethyl ($-CH_2-CH_2$-CN) group into organic substances containing reactive hydrogen atoms is known as cyanoethylation. Cellulose reacts with acrylonitrile in the presence of strong alkalis in a typical manner of primary and secondary alcohols to form cyanoethyl ethers. In cyanoethylation, important factors of reaction are temperature, concentration of the NaOH, and addition rate of acrylronitrile. FT-IR spectra of cyanoethyl group was confirmed at $2250cm^{-1}$, which corresponds the introduction of aliphatic nitrile group. Effect of cyanoethyl DS(degree of substitution) on strength properties was resulted that cyanoethylated BKP of DS 0.04 appeared to be the best choice for overall strength properties. Also, excellent thermal stability in aging characteristics was obtained.

• KEPCO Journal on Electric Power and Energy
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• v.7 no.2
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• pp.249-254
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• 2021

As the spreading speed of electric vehicles increases rapidly, those are expected to be able to use them as flexible resources in the power system beyond the concern for the supply of its charging power. Especially when the Renewable Energy sources (RES) which have no intrinsic control capability have replaced the synchronous generators more and more, the power system needs to secure the additional frequency control resources to ensure its stability. However, the feasibility of using electric vehicles as the frequency control resources should be analyzed from the perspective of the power system operation and it requires the existing simulation frameworks for the power system. Therefore, this paper proposes the grid connected modeling of the primary frequency control provided by electric vehicles which can be integrated into the existing power system model. In addition, the proposed model is implemented considering technical performances constrained by the characteristics of the Vehicle-Grid Integration (VGI) system so that the simulation results can be accepted by the power utilities operating the power system conservatively.

• Journal of the Korea Furniture Society
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• v.25 no.4
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• pp.345-352
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• 2014

This study was carried out to develop eco-friendly wood street lamp (EFWSL) by using wood resources stacked in the forests after tree tending operations which were mostly abandoned, but economical as renewable wood resources for developing the wood coated street lamps with the effects of cost reduction and their attractive appearances. This study has led to the development of key compact structures of street-lighting wood poles (shaft) using laminated timber. The core technique in this study is related with producing the more stable wood poles (shaft) with the hole inside than wood poles exposed under the natural environment through applicable process to protect the wood from bursting and splitting. We also comprehensively developed the method to conserve the timber durability of wood shaft and connect the wood shaft with groove, race way to be located in the groove, locking ring, current stabilizer connected to the groove and luminaire support arm, base and hand-hole which was partly used in combination with steel materials and wood. Also we increased the utilization of abandoned and stacked woods after thinning in the forests such as Pinus densiflora, Larix leptolepis, and Pinus koraiensis plantations by maximizing the value of these natural wood resources as main materials of eco-friendly street lightings with the effects of cost reduction and attractive appearances and also the expectation of advertising effects of street lightings developed in this study.

• Journal of Microbiology and Biotechnology
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• v.26 no.7
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• pp.1278-1284
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• 2016

Rhizopus chinensis cells immobilized on loofah (Luffa cylindrica) sponges were used to produce biodiesel via the transesterification of soybean oil. In whole-cell immobilization, loofah sponge is considered to be a superior alternative to conventional biomass carriers because of its biodegradable and renewable properties. During cell cultivation, Rhizopus chinensis mycelia can spontaneously and firmly adhere to the surface of loofah sponge particles. The optimal conditions for processing 9.65 g soybean oil at 40℃ and 180 rpm using a 3:1 methanol-to-oil molar ratio were found to be 8% cell addition and 3-10% water content (depending on the oil's weight). Under optimal conditions, an over 90% methyl ester yield was achieved after the first reaction batch. The operational stability of immobilized Rhizopus chinensis cells was assayed utilizing a 1:1 methanol-to-oil molar ratio, thus resulting in a 16.5-fold increase in half-life when compared with immobilized cells of the widely studied Rhizopus oryzae. These results suggest that transesterification of vegetable oil using Rhizopus chinensis whole cells immobilized onto loofah sponge is an effective approach for biodiesel production.

• Korean Journal of Organic Agriculture
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• v.17 no.3
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• pp.307-326
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• 2009

The present study suggests a concept of resources circulation type agriculture and a concept of a livestock zone related to it and evaluated economical efficiency about a possibility of the resources circulation type livestock zone based on the concept. As a result, when the resources circulation type livestock zone is operated in an area of 1,300ha, it was evaluated that the profit of 11,244 hundred thousand won per year is generated, compared to the conventional agriculture. When light and heat expenses and roughage of Hanwoo production, production of TMR forage as well as income of the energy and composting business of livestock manure at the recycling center were considered in addition to that, it was judged that the present zone development bushiness has enough business feasibility. However, it is necessary that the support regulations, etc. is constructed so that all produced compost byproducts are used at farmhouses and the system related to facility investment assurance and assistance of operating expenses is maintained. It is thought that the complement of a system is also necessary so that energy or power generation expenses can be operated in the same conditions as other new & renewable energy, and the nation's purchase of carbon credits(CDM) is investigated and systemized in the early period, and construction of a revitalization plan of the business through budget securing of the Ministry of Agriculture and Forestry related to the trade of CDM and carbon emission rights is also a business that should be urgently developed. In the future, the change of an outside environment will further promote use of the energy. Also, as people, who don't know agriculture. farm village, increase day by day because of population concentration in a city, an opportunity that can new added value through experience tourism or educational programs utilizing them is increasing. Accordingly, if programs utilizing social characteristics, such as utilization as a space of tourism. leisure. experience, system construction of bio-energy and system construction that Micro Grid or Smart Grid as a dispersed storage and generation system is stabilized, are constructed, it can be said that revitalization or success conditions of the zone is further achieved.

• Resources Recycling
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• v.31 no.2
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• pp.3-11
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• 2022

Owing to the global development of high-strength alloys and renewable energy industries, the demand for vanadium, a key raw material in these industries, is expected to increase. Until now, vanadium has been recovered as a by-product of the industry, but interest in its direct recovery from minerals has increasing with its significantly increasing demand. In particular, the recovery of vanadium from stone coal ore and vanadium titano-magnetite (VTM) containing vanadium has been actively researched in China, which has the largest reserves and production of vanadium in the world. In Korea, a large amount of VTM also occurs in the northern part of Gyeonggi-do, and fundamental research and technical development is being conducted to recover vanadium. It is necessary to understand the current status of the separation technology used worldwide to satisfy the demand for metals such as vanadium, which currently depends on imports.

• Journal of Contemporary Eastern Asia
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• v.15 no.1
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• pp.41-63
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• 2016

Energy policy is known to have higher path dependency among policy fields (Kuper and van Soest, 2003; OECD, 2012; Kikkawa, 2013) and is a critical component of the infrastructure development undertaken in the early stages of nation building. Actor roles, such as those played by interest groups, are firmly formed, making it unlikely that institutional change can be implemented. In resource-challenged Japan, energy policy is an especially critical policy area for the Japanese government. In comparing energy policy making in Japan and Germany, Japan’s policy community is relatively firm (Hartwig et al., 2015), and it is improbable that institutional change can occur. The Japanese government’s approach to energy policy has shifted incrementally in the past half century, with the most recent being the 2012 implementation of the “Feed-In Tariff Law” (Act on Special Measures Concerning Procurement of Renewable Electric Energy by Operators of Electric Utilities), which encourages new investment in renewable electricity generation and promotes the use of renewable energy. Yet, who were the actors involved and the factors that influenced the establishment of this new law? This study attempts to assess the factors associated with implementing the law as well as the roles of the relevant major actors. In answering this question, we focus on identifying the policy networks among government, political parties, and interest groups, which suggests that success in persuading key economic groups could be a factor in promoting the law. Our data is based on the “Global Environmental Policy Network Survey 2012-2013 (GEPON2)” which was conducted immediately after the March 11, 2011 Great East Japan Earthquake with respondents including political parties, the government, interest groups, and civil society organizations. Our results suggest that the Feed in Tariff (FIT) Law’s network structure is similar to the information network and support network, and that the actors at the center of the network support the FIT Law. The strength of our research lays in our focus on political networks and their contributing mechanism to the law’s implementation through analysis of the political process. From an academic perspective, identifying the key actors and factors may be significant in explaining institutional change in policy areas with high path dependency. Close examination of this issue also has implications for a society that can promote renewable and sustainable energy resources.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.6
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• pp.449-469
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• 2011

This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigerating Engineering during 2010. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) Research trends of thermal and fluid engineering have been surveyed as groups of general thermal and fluid flow, fluid machinery, and new and renewable energy. Various topics were presented in the field of general thermal and fluid flow. Research issues mainly focused on the thermal reliability of axial fan and compressor in the field of fluid machinery. Studies on the design of ground source heat pump systems and solar chemical reactors were executed in the field of new and renewable energy. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics and industrial heat exchangers. Researches on heat transfer characteristics included heat transfer in thermoelectric cooling/power generation systems, combined heat and power systems, carbon nano fluid with PVP, channel filled with metal foam and smoke ventilation in a rescue station of a railroad tunnel. Also the studies on flow boiling of R123/oil mixture in a plain tube bundle and R410A charge amount in an air cooled mini-channel condenser were reported. In the area of industrial heat exchangers, researches on plate heat exchanger, shell and tube heat exchanger, enthalpy exchanger, micro channel PCHE were performed. (3) Refrigeration systems with alternative refrigerants such as hydrocarbons, mixed refrigerants, and CO2 were studied. Performance improvement of refrigeration systems are tried applying various ideas of refrigerant subcooling, dual evaporator with hot gas bypass control and feedforward control. The hybrid solar systems combining the solar collection devices with absorption chillers or compression heat pumps are simulated and studied experimentally as well to improve the understanding and the feasibility for actual applications. (4) Research trend in the field of mechanical building facilities has been found to be mainly focused on field applications rather than performance improvements. Various studies on heating and cooling systems, HVAC facilities, indoor air environments and energy resources were carried to improve the maintenance and management of building service equipments. In the field of heating and cooling systems, papers on a transformer cooling system, a combined heat and power, a slab thermal storage and a heat pump were reported. In the field of HVAC facilities, papers on a cooling load, an ondol and a drying were presented. Also, studies on HVAC systems using unutilized indoor air environments and energy resources such as air curtains, bioviolence, cleanrooms, ventilation, district heating, landfill gas were studied. (5) In the field of architectural environment and energy, studies of various purposes were conducted such as indoor environment, building energy, renewable energy and green building. In particular, renewable energy and building energy-related researches have mainly been studied reflecting the global interest. In addition, many researches which related the domestic green building certification of school building were performed to improve the indoor environment of school.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.2
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• pp.56-62
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• 2013

Organic wastes are not disposing object but renewable resources. One of those ways of rendering to resources, composting is environmentally friendly way as to aspect of recycling of resources. Regardless of ways, composting goes through the main processes which are fermentation process and curing process. In the study, mobile composting device was developed with the experiments which were performed to solve the problems of fermentation and curing process. Since reaction vessel is rotated, it does not cease in the middle of agitation because of foreign. In addition, it mixed as well. With maintaining uniform temperature of reaction vessel by controlling amount of air, fermentation and curing are easy to use. Its economic feasibility is better than the existing fermentation equipments. Furthermore, it benefits to reduce the personnel and materiel maintenance cost, and mass produce composting product which use organic waste. Especially, although it needs less space, it has effect to provide transferable composting device with available area to increase by contacting organic waste to air.