• 유통과학연구
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• 제16권11호
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• pp.11-19
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• 2018

Purpose - The purpose of this study is to provide a systematic literature review related to environmental upgrading in Global Value Chains (GVCs) and suggest possible future research agendas in advancing environmental upgrading and ultimately GVC boundaries. Research design, data, and methodology - The academic databases such as Science Direct, EBSCO, ProQuest and Google Scholar were explored using a structured keywords searches to identify relevant research in the environmental upgrading area in GVCs. Only relevant papers were selected after reading the abstracts, and analyzed using qualitative content analysis. Results - Overall analysis of the literature review suggests two critical developments in the field of environmental upgrading. The first and foremost major development is an enhanced understanding of environmental upgrading as a concept and phenomenon. The second significant development is that environmental upgrading has been empirically proven to be fundamentally based on relationships and power structures within GVCs. Conclusions - Environmental upgrading in GVCs has been studied individually and not in relation to financial outcomes and social upgrading. Hence, the relationship of environmental upgrading with financial outcomes and social upgrading needs to be investigated. Furthermore, the impact of the interaction of varying institutional structures on environmental upgrading is worthy of future study.

• Korean Chemical Engineering Research
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• 제48권5호
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• pp.589-597
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• 2010

하수처리 시스템에서의 생물학적 영양염류 기준이 강화됨에 따라, 표준활성슬러지공법으로 운전 중인 하수처리장의 고도처리 공법으로의 개보수 필요성이 증가하고 있다. 그러나 실제 하수처리 시스템에서의 다양한 유입조건 및 운전조건의 복잡한 반응 구성으로 인해 실험을 통하여 개보수된 고도처리공법의 최적조건을 찾는 것은 쉽지 않은 일이며, 이는 많은 시간과 비용을 소모하여 비효율적이다. 따라서 본 연구에서는 활성슬러지공정모델(ASMs)을 기반으로 한 하수처리장의 모델링 및 시뮬레이션 기법을 통하여 하수처리장의 고도처리공법으로의 upgrading 설계를 수행하며, 이를 통계적이며 체계적으로 접근하기 위해 반응표면분석법(Response surface method)을 통한 고도처리공법의 설계 최적화를 수행하였다. 또한 실규모 하수처리장에서의 운전 최적화를 위해서는 하수처리의 동력학적 매개변수에 대한 정확한 분석이 수행되어야 한다. 본 연구에서는 다변량 통계분석 기법인 부분최소승자법(PLS)을 통하여 하수처리 시스템의 동력학적 매개변수 간의 상관관계를 파악하며, 고도처리공법 하수처리장의 운전 결과에 가장 큰 영향을 미치는 매개변수를 도출하였다. 본 연구를 통해 하수처리장의 고도처리공법 upgrading 설계 및 운전 최적화를 위한 방법론을 제시하였으며, 이를 통하여 설계시간 및 경비 절감 등 고도처리공법으로의 고효율적인 개보수가 가능할 것으로 예상된다.

• Computational Structural Engineering : An International Journal
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• 제1권1호
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• pp.59-69
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• 2001

This study is intended to propose a systematic approach for reliability-based assessment of life cycle cost (LCC) effectiveness and economic efficiency for cost-effective seismic upgrading of existing bridges. The LCC function is expressed as the sum of the upgrading cost and all the discounted life cycle damage costs, which is formulated as a function of the Park-Ang damage index and structural damage probability. The damage costs are expressed in terms of direct damage costs such as repair/replacement costs, human losses and property damage costs, and indirect damage costs such as road user costs and indirect regional economic losses. For dealing with a variety of uncertainties associated with earthquake loads and capacities, a simulation-based reliability approach is used. The SMART-DRAIN-2DX, which is a modified version of the well-known DRAIN-2DX, is extended by incor-porating LCC analysis based on the LCC function developed in the study. Economic efficiencies for optimal seismic upgradings of the continuous PC segmental bridges are assessed using the proposed LCC functions and benefit-cost ratio.

• Bulletin of the Korean Chemical Society
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• 제35권7호
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• pp.1951-1955
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• 2014

Catalytic pyrolysis of Geodae-Uksae 1, a kind of miscanthus found in Korea, was carried out over mesoporous MCM-48 catalysts. For rapid product analysis and catalyst evaluation, pyrolysis-gas chromatography/mass spectrometry was used. X-ray diffraction, nitrogen sorption, pyridine adsorbed Fourier transform infrared, and NH3 temperature programmed desorption were utilized to analyze the properties of the catalysts. Compared to non-catalytic reaction, catalytic upgrading over mesoporous Al-MCM-48 catalysts produced a higher-quality bio-oil with a high stability and low oxygen content. Al-MCM-48 exhibited higher deoxygenation ability than Si-MCM-48 due to its higher acidity.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.172-172
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• 2011

Anaerobic digestion(AD) has successfully been used for many applications that have conclusively demonstrated its ability to recycle biogenic wastes. AD has been successfully applied in industrial waste water treatment, stabilsation of sewage sludge, landfill management and recycling of biowaste and agricultural wastes as manure, energy crops. During AD, i.e. organic materials are decomposed by anaerobic forming bacteria and fina1ly converted to excellent fertilizer and biogas which is primarily composed of methane(CH4) and carbon dioxide(CO2) with smaller amounts of hydrogen sulfide(H2S) and ammonia(NH3), trace gases such as hydrogen(H2), nitrogen(N2), carbon monoxide(CO), oxygen(O2) and contain dust particles and siloxanes. The production and utilisation of biogas has several environmental advantages such as i)a renewable energy source, ii)reduction the release of methane to the atomsphere, iii)use as a substitute for fossil fuels. In utilisation of biogas, most of biogas produced from small scale plant e.g. farm-scale AD plant are used to provide as energy source for cooking and lighting, in most of the industrialised countries for energy recovery, environmental and safety reasons are used in combined heat and power(CHP) engines or as a supplement to natural. In particular, biogas to use as vehicle fuel or for grid injection there different biogas treatment steps are necessary, it is important to have a high energy content in biogas with biogas purification and upgrading. The energy content of biogas is in direct proportion to the methane content and by removing trace gases and carbon dioxide in the purification and upgrading process the energy content of biogas in increased. The process of purification and upgrading biogas generates new possibilities for its use since it can then replace natural gas, which is used extensively in many countries, However, those technologies add to the costs of biogas production. It is important to have an optimized purification and upgrading process in terms of low energy consumption and high efficiency giving high methane content in the upgraded gas. A number of technologies for purification and upgrading of biogas have been developed to use as a vehicle fuel or grid injection during the passed twenty years, and several technologies exist today and they are continually being improved. The biomethane which is produced from the purification and the upgrading process of biogas has gained increased attention due to rising oil and natural gas prices and increasing targets for renewable fuel quotes in many countries. New plants are continually being built and the number of biomethane plants was around 100 in 2009.

• 공업화학
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• 제20권1호
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• pp.1-8
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• 2009

바이오오일은 고부가가치 화학물질이나 차세대 탄화수소 연료 생산을 위한 석유정제시설의 연료로서 사용이 가능하기 때문에 전도유망한 신재생 에너지원 가운데 하나로 상당한 관심을 불러일으키고 있다. 바이오오일을 석유정제시설에 공급하기 위해서는 전처리 과정으로 안정화 공정이 필요하며, 이를 위한 방법 가운데 현재로서는 촉매 접촉 분해법이 잠재성이 가장 높은 것으로 인식되고 있다. 본 총설에서는 촉매 접촉 분해법을 활용한 바이오오일 개질에 관한 최근 연구 동향을 적용된 촉매의 성능과 개질 방법을 중심으로 소개하고자 한다.

• Structural Engineering and Mechanics
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• 제26권3호
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• pp.277-295
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• 2007

3-D wall panels are used in construction of exterior and interior bearing and non-load bearing walls and floors of building of all types of construction. Fast construction, thermal insulation, reduced labor expense and weight saving are the most well pronounced advantage of such precast system. When the structural performance is concerned, the main disadvantage of 3D panel, when used as floor slab, is their brittleness in flexure. The current study focuses on upgrading ductility and load carrying capacity of 3D slabs in two different ways; using additional tension reinforcement, and inserting a longitudinal concentrated beam. The research is carried on both experimentally and numerically. The structural performance in terms of load carrying capacity and flexural ductility are discussed in details. The obtained results could give better understanding and design consideration of such prefabricated system.

• 한국전기전자재료학회논문지
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• 제23권8호
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• pp.645-650
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• 2010

The continuous increase demand for electric power leads to the additional construction of transmission facilities, but it is not easy to acquire right-of-way for transmission facilities. Therefor, there is a need for compact tower that can be built on a narrow right-of-way the compact tower with polymer insulation arm is a solution. It can be upgrading conventional 154 kV transmission line voltages to 345 kV levels. However transmission voltage is increasing, environment interference (corona noise, radio interference, etc.) will occur gradually. This environment interference is depending on the electrical clearances of tower and configuration of conductors. Therefore the analysis of the factors of environmental interference is necessary in order to upgrading transmission voltage. This paper presents the design factor of a compact tower to meet the environmental interference standard.

• 한국실내디자인학회논문집
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• 제21권6호
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• pp.260-270
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• 2012

The demographic and environmental changes such as the decrease of the population growth rate and the increase of the population of the senior citizens, which become issues of the modern society, are bringing numerous changes of many aspects like national economy, community, and culture. These social phenomena give impacts on the school facilities as well. Thus owing to the decrease of the number of the students, the number of the newly constructed schools has been decreased drastically, and moreover the merger of the schools cause many schools to be default. Meanwhile, the school facilities have been expanded into the functions of the local community centers, and the various educational activities demand the diversity and flexibility of the spaces. These factors add more burdens to the current schools. Therefore the school facilities are needed to adopt a flexible and relevant change necessary for using the spaces in accordance with the changed needs of the times, and are needed to reinvented continuously not to limit the educational and social activities because of the degradation of the school facilities. Yet because there are no proper criteria for doing the task, problems related to the relevance of the task and the unnecessary investment are raised. So through this study I tried to demonstrate the standardized index in terms of the sequential priority of upgrading the facilities among the schools.

• 유기물자원화
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• 제27권1호
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• pp.77-85
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• 2019

바이오가스화는 유기성폐기물을 처리하는 과정에서 발생되는 메탄가스를 포함하는 환경 친화적인 연료를 생산하는 기술이다. 바이오가스화는 유기성폐기물의 해양투기 금지 이후 안정적인 육상처리일 뿐만 아니라 신재생에너지원으로 인정받으면서 세계적인 관심을 받고 있다. 최근에는 생산된 바이오가스를 고품질화하여 도시가스 및 수송용으로 이용하는 추세가 증가하고 있다. 바이오가스화 현장시설에서는 아직도 잦은 고장으로 바이오가스 생산이 저하되고, 또한 생산된 바이오가스를 효과적으로 정제하여 이용하는 것이 미흡한 실정이다. 이 연구에서는 바이오가스 생산 및 이용 시설에서의 문제점들을 파악하고, 최적으로 바이오가스를 도시가스 및 수송용으로 활용 가능하기 위한 가이드라인 및 기술지침을 마련하고자 하였다.