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        검색결과 781

        221.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        This study presents a sustainable design method to optimize the embodied energy and CO2 emission complying with the design code for reinforced concrete column. The sustainable design method effectively achieves the minimization of the environmental load and energy consumption whereas the conventional design method has been mostly focused on the cost saving. Failure of reinforced concrete column exhibits compressive or tensile failure mode against an external force such as flexure and compression; thus, optimization analyses are conducted for both failure modes. For the given sections and reinforcement ratios, the optimized sections are determined by optimizing cost, embodied energy, and CO2 emission and various aspects of the sections are thoroughly investigated. The optimization analysis results show that 25% embodied energy and 55% CO2 emission can be approximately reduced by 10% increase in cost. In particular, the embodied energy and CO2 emission were more effectively reduced in the tensile failure mode rather than in the compressive failure mode. Consequently, it was proved that the sustainable design method effectively implements the concept of sustainable development in the design of reinforced concrete structure by optimizing embodied energy consumption and CO2 emission.
        4,000원
        222.
        2017.06 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In order to reduce odor and methane emission from the landfill, open biocovers and a closed biofilter were applied to the landfill site. Three biocovers and the biofilter are suitable for relatively small-sized landfills with facilities that cannot resource methane into recovery due to small volumes of methane emission. Biocover-1 consists only of the soil of the landfill site while biocover-2 is mixed with the earthworm casts and artificial soil (perlite). The biofilter formed a bio-layer by adding mixed food waste compost as packing material of biocover-2. The removal efficiency decreased over time on biocover-1. However, biocover-2 and the biofilter showed stable odor removal efficiency. The rates of methane removal efficiency were in order of biofilter (94.9%)>, biocover-1(42.3%)>, and biocover-2 (37.0%). The methane removal efficiency over time in biocover-1 was gradually decreased. However, drastic efficiency decline was observed in biocover-2 due to the hardening process. As a result of overturning the surface soil where the hardening process was observed, methane removal efficiency increased again. The biofilter showed stable methane removal efficiency without degradation. The estimate methane oxidation rate in biocover- 1 was an average of 10.4%. Biocover-2 showed an efficiency of 46.3% after 25 days of forming biocover. However, due to hardening process efficiency dropped to 4.6%. After overturn of the surface soil, the rate subsequently increased to 17.9%, with an evaluated average of 12.5%.
        4,200원
        224.
        2017.04 KCI 등재 구독 인증기관 무료, 개인회원 유료
        연구에서는 펄프공정으로부터 배출되는 리그닌 추출물 내의 금속이온분리를 위한 연구를 진행하였다. α- Alumina 분말에 DMAc (N,N-dimethylacetamide) 용매와 PESf (Polyethersulfone) 고분자를 혼합하고 PVP (Polyvinylpyrrolidone) 분산제를 첨가하여 슬립 캐스팅 방법으로 분리막을 제조하였다. 분리막은 CFP (Capillary Flow Porometer) 장치 를 통해 기공크기를 측정하고 FE-SEM (Field Emission Scanning Electron Microscope) 장치를 이용하여 실제 분리막 표면과 단면을 관찰하였다. 플럭스는 분리 실험장치를 이용하여 시간당 여과된 무게를 측정하여 계산하였다. 기공크기측정은 0 psi에 서 30 psi까지 서서히 증가하는 승압조건에서 진행하였다. 분리막의 기공크기는 0.4 μm 크기를 가지며 플럭스는 분리막의 파 울링에 의해 초기 플럭스 값인 6.36 kg⋅m-2⋅h-1에서 1.98 kg⋅m-2⋅h-1으로 감소하여 3시간 이후부터 일정해지는 것을 확인 하였다. 투과 실험 후 막 오염물질은 간단한 세척을 통해 제거 가능하였다. 분리실험을 통해 초기 리그닌 추출물 내에 포함되 어 있던 Na은 69%만큼 줄었고, Fe은 87%, K은 95%, Ca은 93%, Mg은 96%만큼 제거됨을 보였다
        4,000원
        227.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Greenhouse gas emission from agricultural land is recognized as an important factor influencing climatic change. In this study, the national CO2 emission was estimated for paddy soils, using soil GHG emission model (DNDC) with 1 km2 scale. To evaluate the applicability of the model in Korea, verification was carried out based on field measurement data using a closed chamber. The total national CO2 emission in 2015 was estimated at 5,314 kt CO2-eq, with the emission per unit area ranging from 2.2~10.0 t CO2-eq ha-1. Geographically, the emission of Jeju province was particularly high, and the emission from the southern region was generally high. The result of the model verification analysis with the field data collected in this study (n=16) indicates that the relation between the field measurement and the model prediction was statistically similar (RMSE=22.2, ME=0.28, and r2=0.53). More field measurements under various climate conditions, and subsequent model verification with extended data sets, are further required.
        4,000원
        228.
        2017.03 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Daecheong Reservoir was made by the construction of a large dam (>15 m in height) on the middle to downstream of the Geum River and the discharge systems have the watergate-spillway (WS), a hydropower penstock (HPP), and two intake towers. The purpose of this study was to investigate the limnological anomalies of turbid water reduction, green algae phenomenon, and oligotrophic state in the lower part of reservoir dam site, and compared with hydro-meteorological factors. Field surveys were conducted in two stations of near dam and the outlet of HPP with one week intervals from January to December 2000. Rainfall was closely related to the fluctuations of inflow, outflow and water level. The rainfall pattern was depended on the storm of monsoon and typhoon, and the increase of discharge and turbidity responded more strongly to the intensity than the frequency. Water temperature and DO fluctuations within the reservoir water layer were influenced by meteorological and hydrological events, and these were mainly caused by water level fluctuation based on temperature stratification, density current and discharge types. The discharges of WS and HPP induced to the flow of water bodies and the outflows of turbid water and nutrients such as nitrogen and phosphorus, respectively. Especially, when hypoxic or low-oxygen condition was present in the bottom water, the discharge through HPP has contributed significantly to the outflow of phosphorus released from the sediment into the downstream of dam. In addition, HPP effluent which be continuously operated throughout the year, was the main factor that could change to a low trophic level in the downreservoir (lacustrine zone). And water-bloom (green-tide) occurring in the lower part of reservoir was the result that the water body of upreservoir being transported and diffused toward the downreseroir, when discharging through the WS. Finally, the hydropower effluent was included the importance and dynamics that could have a temporal and spatial impacts on the physical, chemical and biological factors of the reservoir ecosystem.
        4,800원
        229.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The concern on the greenhouse gas emissions is increasing globally. Especially, the greenhouse gas emission from fisheries is an important issue due to Cancun Agreements Mexico in 1992 and the Kyoto protocol in 2005. Furthermore, the Korean government has a plan to reduce the GHG emissions as 5.2% compared to the BAU in fisheries until 2020. However, the investigation on the GHG emissions from Korean fisheries has not been executed much. Therefore, the quantitative analysis of GHG emissions from Korean fishery industry is needed as the first step to find a relevant way to reduce GHG emissions from fisheries. The purpose of this research is to investigate which degree of GHG emitted from the major coastal fisheries such as coastal gillnet fishery, coastal dual purpose fishery, coastal pots fishery and coastal small scale stow net fishery. Here, we calculated the GHG emission from the fisheries using the LCA (Life Cycle Assessment) method. The system boundary and input parameters for each process level are defined for LCA analysis. The fuel use coefficients of the fisheries are also calculated according to the fuel type. The GHG emissions from sea activities by the fisheries will be dealt with. Furthermore, the GHG emissions for the unit weight of fishes are also calculated with consideration to the different consuming areas. The results will be helpful to understand the circumstances of GHG emissions from Korean fisheries.
        4,300원
        230.
        2017.02 KCI 등재 구독 인증기관 무료, 개인회원 유료
        The water removal characteristics in a PEMFC trapezoidal gas channel are investigated with the volume of fluid (VOF) method. For the case of wall contact angle of 60 degree, liquid water attaches on the top wall and moves toward the exit. In contrast, liquid water moves along the channel side corner or GDL surface irregularly for the higher wall contact angles. The hydrophillic wall contact angle of 60 degrees provides more favorable diffusion of reactants to cathode reaction sites as the GDL surface water coverage ratio approaches zero even if the water flow rate increases.
        4,000원
        231.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        대부분의 온실가스는 에너지의 생성 및 이용으로부터 발생되고, 교통부문에서 배출되는 온실가스 중 약 95 % 이상이 수송용 연료에서 기인한다. 또한, IPCC 가이드라인에서 제시하는 배출계수를 사용하였을 경우 국가 고유의 연료특성이 반영되지 않는 단점이 있고, 기후변화협약 교토의정서에 따른 의무 감축국도 UN에 제출하는 국가 온실가스 배출량 보고서 작성 시 대부분 Tier 2나 Tier 3 수준의 배출계수를 적용하고 있 다. 본 연구에서는 국내 교통부문에 사용되는 휘발유, 경유 등의 수송용 연료에 대한 연차별 시계열 특성을 파 악하고, CO2 배출계수의 연도별 변화추이를 분석하여 실제 연료를 활용한 CO2배출계수 실측방법의 적용 타 당성을 평가하였다.
        4,000원
        232.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, we investigated influent and effluent water pollutants in 53 Public Sewage Treatment Works (PSTWs) where industrial wastewater or landfill leachate is combined four times for two years from 2014 to 2015. Also, we analyzed the characteristics of heavy metals and volatile organic carbons at influent and effluent of these PSTWs caused by sewage treatment combined with industrial wastewater or landfill leachate. As a result, six heavy metals such as barium, copper, iron, manganese, nickel and zinc, and four volatile organic carbons (VOCs) including phenols, di(2-)ethylhexyl phthalate (DEHP), formaldehyde and toluene were observed above detection limits in most of PSTWs. Also, it was revealed that six heavy metals such as hexavalent chromium, mercury, cadmium, chromium, nickel and selenium, and four VOCs including 1,1-dichloroethylene, vinyl chloride, naphthalene, and epichlorohydrin were observed more frequently according to precipitation. As a result of reviewing the monitoring data on “Water Quality Monitoring Networks” in lower watersheds of PSTWs, both heavy metals and VOCs were below detection limits, indicating that the effluent water had little influence on the watershed. Nevertheless for the better management of influent and effluent pollutants in PSTWs, it is necessary to establish the advanced management plans for water pollutants in PSTWs, which include a list of priority substances management, monitoring plans, and guidelines for industrial wastewater and landfill leachate combined in PSTWs.
        4,000원
        233.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this study, swine and cattle farms located in Jeollanam-do were selected to analyze and evaluate the components of odorants in livestock facilities. In addition, a preliminary survey of the literature was conducted to establish a sampling and analysis method for phenol and indoles which are major components of odor emissions from livestock facilities, yet are not regulated by the laws. To establish a sampling and analysis method for phenol and indoles, Tedlar bag and Tenax-TA sorbent tube was used as background concentration of blank sample and samples according to the elapsed time. The results obtained indicate the GC/MS analysis with Tenax-TA sorbent tube sampling was an effective method for measuring the compounds of phenol and indoles. In the swine facility, the rankings of the odorants in order, from highest to lowest, were ammonia, sulfuric compounds, phenol/indoles, volatile fatty acids. The main odorants were hydrogen sulfide (41.3%) and 4-methylphenol (p-cresol, 13.9%). In the swine slurry storage, hydrogen sulfide (33.7%), ammonia (18.8%), and 3-methylindole (skatole, 15.7%) were the main odorants, and hydrogen sulfide (31%) and i-valeric acid (32.4%) were the main odorants in the cattle farms.
        4,900원
        234.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        Objective of this study was to evaluate the carbon budget on 40 years old pear orchard at Naju. For carbon budget assessment, we measured the soil respiration, net ecosystem productivity of herbs, pear biomass and net ecosystem exchange. In 2015, pear orchard released about 25.6 ton CO2 ha-1 by soil respiration. And 27.9 ton CO2 ha-1 was sequestrated by biomass growth. Also about 12.6 ton CO2 ha-1 was stored at pruning branches and about 5.2 ton CO2 ha-1 for photosynthesis of herbs. As a result, 25.6 ton of CO2 per ha is annually released to atmosphere. At the same time about 45.7 ton of CO2 was sequestrated from atmosphere. When it sum up the amount of CO2 release and sequestration, approximately 20.1 ton CO2 ha-1 was sequestrated by pear orchard in 2015, and it showed no significant differences with net ecosystem exchanges (17.8 ton CO2 ha-1 yr-1) by eddy covariance method with the same period. Continuous research using various techniques will help the understanding of CO2 dynamics in agroecosystem and it can be able to present a new methodology for assessment of carbon budget in woody crop field. Futhermore, it is expected that the this study can be used as the basic data to be recognized as a carbon sink.
        4,000원
        235.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        In this paper, the relationship between energy consumption in the logistics industry and economic growth of Tumen River region from 1995 to 2014 is empirically analyzed by using the EKC model theory. The results show that there is a turning point in the Kuznets curve of carbon emission in TumenRiverregion. And it has the characteristic sof "invertedU" curve, which conforms to the environmental Kuznets curve hypothesis. Meanwhile it is stil lintherisingstage. According to the analysis results, it is proposed to set up the concept of low carbon logistics, optimize the energy structure, strengthen the information construction, and establish low-carbon development mechanism and so on.
        4,000원
        236.
        2016.12 KCI 등재 구독 인증기관 무료, 개인회원 유료
        OBJECTIVES: Currently, the market for carbon emissions trading has been increasing. In Korea, it is known that traffic mode rate in bike transportation is low. However, if bike transportation system is encouraged and the traffic mode rate is increased, it would be possible to reduce carbon emissions through the trading market. In this study, a practical policy to activate the bike transportation system in Korea will be proposed and verified. METHODS: Past studies regarding bike transportation system in international and domestic metropolitan cities were analyzed. Moreover, detailed reviews on recent carbon emissions trading market were performed. In particular, SWOT analysis on the bike transportation system in Korea and policy topology analysis were conducted. RESULTS: Based on the literature reviews and SWOT analysis, a new bike transportation policy was proposed. Several actual plans to adopt in Korea were proposed. In addition, a new bike transportation policy was analyzed using policy typology model, and a business model related to the cost of implementing the system and CERs were also proposed. CONCLUSIONS : It is concluded that the proposed bike transportation activation policy and several practical plans to connect CERs and a business model including bus, subway, T-money and bike riders to give some incentive were effective and reasonable. It is desired that this study will help Korea to get CERs through bike transportation activation in the future.
        4,000원
        239.
        2016.10 KCI 등재 구독 인증기관 무료, 개인회원 유료
        본 연구에서는 철근콘크리트 건물에 대한 유전자 알고리즘 기반의 최적구조설계기법을 제시하고자 한다. 목적함수는 구조 물의 비용과 이산화탄소 배출량을 동시에 각각 최소화하는 것이다. 비용 및 인산화탄소 배출량은 구조설계안에서 얻을 수 있는 단면치수, 부재길이, 재료강도, 철근량 등과 같은 설계정보를 통해 계산한다. 즉, 구조물의 물량을 기초로 하여 비용과 이산화탄소 배출량을 평가한다. 재료의 운반, 시공 및 건물 운영 단계에서 발생하는 비용 및 이산화탄소 배출량은 본 연구에 서 제외한다. 제약조건은 철근콘크리트 건물을 구성하는 기둥과 보 부재의 강도조건과 층간변위조건이 고려된다. 제약조건 을 평가하기 위해 OpenSees를 활용한 선형정적해석이 수행된다. 제약조건을 만족시키면서 목적함수에 대해 최소의 값을 제 시하는 설계안을 찾기 위해 유전자 알고리즘이 사용된다. 제시한 알고리즘의 적용성을 검증하기 위해 4층 철근콘크리트 모 멘트 골조 예제에 제시하는 기법을 적용하여 검증한다.
        4,000원