검색결과

검색조건
좁혀보기
검색필터
결과 내 재검색

간행물

    분야

      발행연도

      -

        검색결과 11

        1.
        2014.11 구독 인증기관·개인회원 무료
        현대농업에서 부각되는 식물공장의 문제점은 해충 문제 이다. 본 연구는 식물공장에서 가장 문제가 되는 진딧물의 피해를 줄이는데 효과적인 광원을 찾는데 목적이 있다. 구 배는 적색+청색 혼합광(R+B), 적색+청색+백색 혼합광 (R+B+W), 적색+적외선 혼합광(R+fR), 적색(R), 청색(B), 적외선(fR), 황색(Y), 백색(W)으로 구성하였다. 처리한 duty 비는 R+B에서 100%, 95%, 90%, 85%, 80%, 75%, R+B+W에서 100%, 85%, 70%로, 나머지 광원은 100%이 었다. R+B은 75%에서 R+B+W은 100%에서 진딧물 발생 량이 가장 적었다. 광원에 따른 결과, fR일 때 진딧물 발생 량이 가장 적었다. Hz는 R+B에서 20, 60, 180, 540, 1620, 4860으로 R+B+W에서 60, 180, 540, 1620으로, 나머지 광 원은 180이었다. R+B에서 Hz가 540일 때 진딧물 발생량이 가장 많았다. R+B+W의 경우 Hz가 540일 때 가장 적었다. Hz가 180으로 동일할 때 진딧물 발생량은 R+B, R+B+W, fR일 때 가장 낮았다. 진딧물이 가장 적은 광원은 fR이었다. 따라서 진딧물의 피해를 줄이기 위해서는 fR에서 재배하는 것이 가장 효율적이다.
        3.
        2016.11 KCI 등재 서비스 종료(열람 제한)
        최근 다양한 형태의 막구조물의 건설이 증가추세이지만 막구조물에 적합하지 않은 내화기준이 적용되어 활용성이 위축되고 있는 실정이다. 그렇기 때문에 막구조물의 건설 활성화에 맞추어서 이에 대한 내화기준의 제·개정이 필요한 상황이다. 따라서 본 연구에서는 일반적 으로 많이 사용되는 막재료(ETFE, PVF, PTFE)를 선정하여 막구조물에 화재가 일어났을 때, 시간이 변화함에 따라 온도가 올라가는 막재료의 물리적인 특성 변화와 발열량과 막재료 설치높이와의 상관관계를 파악하여 막구조 내화기준에 기초 자료로 활용하고자 한다.
        4.
        2015.05 서비스 종료(열람 제한)
        Mathematical models have been developed to evaluate methane emission from landfills. The Intergovernmental Panel on Climate Change (IPCC) and the US Environmental Protection Agency (USEPA) have provided first-order decay (FOD) models to estimate methane emission from landfills. The methane generation potential (L0) and the methane generation rate constant (k) are the two primary parameters in the FOD model. A major challenge in landfill gas modeling is estimating these parameters. The IPCC recommended that every country should develop country-specific emission factors appropriate for its circumstances and characteristics. The k value represents the rate constant associated with waste decomposition. In general, there are two different approaches for estimating a k value for a landfill. One uses actual field data in comparison with modeled data. However, this approach is limited by the spatial and temporal characteristics of landfill. Another approach is to collect samples of landfilled waste and then measure their biodegradability of waste as a function of waste age. As biodegradability is a surrogate for landfilling age, lower biodegradability would be expected in order samples. The objective of this study was to determine a k value using an anaerobic test (GB21). To achieve this objective, the GB21 which is used in Germany was conducted to estimate biodegradability of waste samples, and k value was determined based on FOD equation. Waste samples were collected at a landfill located in A City, Korea. The landfill is a valley-type landfill. It received municipal solid waste from 1990 to 2010. Food and paper wastes were the major fractions, constituting about 62.9% of the total amount disposed. However, the Ministry of Environment in Korea banned direct landfilling of food wastes in 2005, since then, food waste has no longer been disposed into landfills. In this study, the landfill site was separated into four areas based on landfilling age, and four samples were collected from each area. Cumulative biogas production for the waste excavated from the landfill varied from 6.9 to 35.8 Nl/kg-Dry Matter. Cumulative biogas production for landfilling age of 1 year was 35.8 Nl/kg-DM and it decreased to 6.9 Nl/kg-DM after 14 years. The k value obtained from this study was 0.156 yr-1 and was higher than the default k prescribed by the IPCC, which is 0.09 yr-1 in boreal and temperate climates. The higher k values obtained in this study can be explained by the high proportion of food waste disposed into the studied landfill. The default k values of rapidly degrading wastes including food waste and sludge are 0.185 yr-1. In addition a higher k value will result in predictions of more methane generation in the early years after waste burial, resulting in higher estimates of uncollected methane in greenhouse gas inventories. This work contributes to understanding decomposition rate of landfilled waste by examining biodegradability determination and providing k value for landfill.
        5.
        2014.06 KCI 등재 서비스 종료(열람 제한)
        The management of household hazardous waste (HHW), a component of municipal solid waste (MSW) has become a major of concern partly due to their potential toxicity upon disposal. Improper management of such waste can deteriorate the environment and cause serious damage to the human health. This paper discusses the current fundamental management practices, which include the generation rate, collection systems and treatment using the survey reviews of households and interviews held with experts in the Daejeon metropolitan city. Surveys of more than 378 people in Daejeon Metropolitan City were conducted to investigate the characteristics, generation rate, social behavior and awareness regarding disposal of HHW. The target items used in this study includes used lamps, used batteries, pharmaceuticals, and household pesticide chemicals. According to the survey conducted, the generation rates of HHW varied depending upon the dwelling type, collection system, and waste type. Apartment complex residents participated actively in source separation, using the established collection system with limited items (e.g., fluorescent lamps and batteries), while single family housing residents tend to store HHW at households. There is still a need for public awareness, detailed policies and legislation requiring source segregation at households, and better collection systems for HHW. The results of this study can be used for developing better management of HHW in municipal solid waste streams to prevent potential environmental impacts and human health risks.
        6.
        2014.01 KCI 등재 서비스 종료(열람 제한)
        Leachate generation is an inevitable consequence of waste disposal in landfills. Numerous mathematical modelshave been developed to simulate leachate occurrence and behavior. However, these models have been successful toa limited extent because of uncertainties associated with biological, chemical, and physical processes in landfills. Inorder to predict the generation of leachate in closed landfills, correlation analysis was conducted based on precipitationin this paper. Regression analysis for deriving the correlation between precipitation and leachate generation rate wasperformed in a closed landfill. As a result, we found that the amount of leachate which is generated regardless ofprecipitation should be considered as well as the percolation of precipitation. Also, it was possible to make an fairlyaccurate prediction of leachate generation only using precipitation data in this paper. It is suggested that the amountof leachate generation is 4~8% of monthly precipitation and about 25,000m3/month of base generation regardlessof precipitation. However, the predicted values of leachate generation for the high precipitation seasons were not closeto those observed.
        7.
        2009.01 KCI 등재 서비스 종료(열람 제한)
        Fabrication and oxidants production of 3 or 4 components metal oxide electrode, which is known to be so effective to destruct non-biodegradable organics in wastewater, were studied. Five electrode materials (Ru as main component and Pt, Sn, Sb and Gd as minor components) were used for the 3 or 4 components electrode. The metal oxide electrode was prepared by coating the electrode material on the surface of the titanium mesh and then thermal oxidation at 500℃ for 1 h. The removed RhB per 2 min and unit W of 3 components electrode was in the order: Ru:Sn:Sb=9:1:1 > Ru:Pt:Gd=5:5:1 > Ru:Sn=9:1 > Ru:Sn:Gd=9:1:1 > Ru:Sb:Gd=9:1:1. Although RhB decolorization of Ru:Sn:Sb:Gd electrode was the highest among the 4 components electrode, the RhB decolorization and oxidants formation of the Ru:Sn:Sb=9:1:1 electrode was higher than that of the 3 and 4 components electrode. Electrogenerated oxidants (free Cl and ClO2) of chlorine type in 3 and 4 components electrode were higher than other oxidants such as H2O2 and O3. It was assumed that electrode with high RhB decolorization showed high oxidant generation and COD removal efficiency. OH radical which is electrogenerated by the direct electrolysis was not generated the entire 3 and 4 components electrode, therefore main mechanism of RhB degradation by metal oxide electrode based Ru was considered indirect electrolysis using electrogenerated oxidants.
        8.
        2009.01 KCI 등재 서비스 종료(열람 제한)
        Fabrication and oxidants formation of 1 and 2 component metal oxide electrode, which is known to be so effective to destruct non-biodegradable organics in wastewater, were studied. Five electrode materials (Ru, Pt, Sn, Sb and Gd) were used for the 1 and 2 component electrode. The metal oxide electrode was prepared by coating the electrode material on the surface of the titanium mesh and then thermal oxidation at 500℃ for 1 h. The removed RhB per 2 min and unit W for one component electrode decreased in the following sequences: Ru/Ti > Sb/Ti > Pt/Ti > Gd/Ti > Sn/Ti. The concentration of oxidants generated in 1 and 2 component electrodes was in the order of: ClO2 > free Cl > H2O2 > O3. OH radical was not generated from in entire one and two component electrodes. RhB degradation rate and generated oxidants of the Ru-Sn=9:1 electrode was higher than that of the two component electrode. The exact relationship between the removal of RhB and the generated oxidants concentration was not obvious. However, it was assumed that electrode with high RhB decolorization had high oxidant concentration.
        9.
        2004.07 KCI 등재 서비스 종료(열람 제한)
        Most of methane gas result from waste matter in landfill, therefore the persons concerned take an increasing interest in management of gases in landfill. Infrared Gas Analyzer was used to measure components of gases, CH4, CO2, O2, through gas exhausted pipe. To measure amount of the gas flow meter(Portable Hot-Line Current Meter) was used and it was set at right angles with direction of the flow. In this research the total amount of methane gas produced in Beck-Suk Landfill was calculated through FOD method suggested by IPCC. This research found that in Chon-An Beck-Suk Landfill anaerobic resolution was made actively and the amount of methane gas produced there was 54.14%, which is higher than common figure, 50%, in other researches. The components of reclaimed waste matter, especially, organic waste matter can have a great effect of the amount of the greenhouse gases produced in landfill. We can expect that the amount of greenhouse gas will decrease from 2005, when it will be prohibited from carrying kitchen refuse and sludge into landfill.
        10.
        2004.07 KCI 등재 서비스 종료(열람 제한)
        Indoor air quality is affected by source strength of pollutants, ventilation rate, decay rate, outdoor level, and so on. Although technologies measuring these factors exist directly, direct measurements of all factors are not always practical in most field studies. The purpose of this study was to develop an alternative method to estimate these factors by application of multiple measurements. For the total duration of 30 days, daily indoor and outdoor NO2 concentrations were measured in 30 houses in Brisbane, Australia, and for 21 days in 40 houses in Seoul, Korea, respectively. Using a box model by mass balance and linear regression analysis, penetration factor (ventilation divided by sum of air exchange rate and deposition constant) and source strength factor (emission rate divided by sum of air exchange rate and deposition constant) were calculated. Subsequently, the ventilation and source strength were estimated. In Brisbane, the penetration factors were 0.59±0.14 and they were unaffected by the presence of a gas range. During sampling period, geometric mean of natural ventilation was estimated to be 1.10±1.51 ACH, assuming a residential NO2 decay rate of 0.8 hr-1 in Brisbane. In Seoul, natural ventilation was 1.15±1.73 ACH with residential NO2 decay rate of 0.94 hr-1. Source strength of NO2 in the houses with gas range (12.7±9.8 ppb/hr) were significantly higher than those in houses with an electric range (2.8±2.6 ppb/hr) in Brisbane. In Seoul, source strength in the houses with gas range were 16.8±8.2 ppb/hr. Conclusively, indoor air quality using box model by mass balance was effectively characterized.
        11.
        1994.04 KCI 등재 서비스 종료(열람 제한)
        Hordeum bulbosum을 이용한 보리 반수체육종법의 실용화를 체계화하기 위해 일련의 실험을 실시하였으며, 유배의 적취시기, 유배의 크기에 따른 배배양 반응, 배지 및 환경조건 등을 조사하였다. 1. 유배의 적취시기는 배발육과 식물체 발생률을 고려할 때 수분 후 17일이 적기였다. 2. 식물체 발생에 유리한 유배의 크기는 0.9mm내외였다. 3. 식물체 발생에 효과적인 배지 및 배양조건은 MS배지의 암상태에서 발생시킨 후 명상태로 하는 것이 정상 식물체 발생률(3%)이 높았으나, 작업상의 편리성을 고려한다면 B5배지에서 24시간의 일장처리조건이 좋았다. 4. 반수체는 정상 2배체에 비하여 배 및 식물체의 발생이 현저히 부진하였다.