• 한국환경과학회지
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• 제15권7호
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• pp.669-676
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• 2006

PAHs are major pollutants that are widely distributed in soil and groundwater environment, so that may be regarded as carcinogens. We investigated the degradation kinetics of PAH in aqueous solution when low pressure UV energy and ultrasonic irradiation were applied. Phenanthrene and pyrene were used as model compounds. The degrees of degradation of these compounds with time were analyzed with a GC/MSD (SIM-mode). UV photolysis experiments showed that phenanthrene was reduced by 90 -67% at initial concentrations of 1 ppm to 8ppm whilst it decreased to 50% at 10 ppm. Under the same conditions pyrene was degraded up to about 75% at lower initial concentrations but the reduction efficiency dropped to a level of 34 to 29% at the higher concentrations above 8 ppm. The reaction orders for phenanthrene and pyrene were found to be zero-th and ca. -0.4th order, respectively, thus implying that the reported assumption of pseudo 1st order reaction for some PAHs would be no longer valid. PAH degradation was roughly proportional to the intensity of UV (number of lamps), exhibiting maximum 92.5% of the degradation efficiency. The solution pH was lowered to 4.4 from 6.4 during the experiments partially because the carbons decomposed by the energy reacted with oxygen radicals to produce carbon dioxides. Ultrasonic irradiation on phenanthrene solutions gave relatively poor results which matched to 50 to 70% of degradation efficiency even at 2 ppm of initial concentration. Phenanthrene was found to be degraded more efficiently than pyrene for the two energy sources. Ultrasound also followed the same reaction kinetics as UV energy on PAH degradation.

• 자원ㆍ환경경제연구
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• 제18권4호
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• pp.557-586
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• 2009

고유가와 기후변화로 인해 에너지 수요관리정책에 대한 관심이 국내외 적으로 높아지고 있다. 그렇지만 국내에서는 에너지 수요관리와 관련해서 지방정부의 역할이 미약하기만 한 실정이다. 에너지 수요관리정책과 관련해서는 기술력과 자금을 확보한 중앙정부의 역할이 중요하겠지만 직접적인 에너지 소비지에 밀착되어 있는 지방정부의 역할도 중요할 수 있다. 따라서 지방정부의 에너지 수요관리정책을 활성화시키고 5년마다 수립되는 '지역에너지계획'의 실행력을 높이기 위해서는 지역의 에너지 소비특성에 대한 정확한 이해에 기반한 계획의 수립이 필요하다. 이에 본 논문에서는 전국 16개 지자체의 에너지 소비를 인구, 생산, 원단위라는 항목으로 분해해서 그 특성을 분석하고자 한다. 지수분해분석 결과 광역시의 경우에는 외환위기 이후 생산 증가로 인한 에너지 소비 증가를 원단위 개선 효과로 일정 부분 상쇄시킨 것으로 나타났다. 반면에 도 지역의 경우에는 제조업 중심의 산업화로 인해 외환위기 이후에도 에너지 소비 증가를 상쇄시키지 못한 것으로 나타났다. 결론적으로 본 논문에서는 제조업 비중이 높은 도 지역의 경우 에너지 저소비형 산업구조로의 전환이 필요하며, 3차 산업 중심의 구조전환이 이루어진 광역시의 경우에는 건물, 수송 분야의 에너지 효율개선이 필요함을 제안할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.670-674
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• 2012

The photovoltaic performance of solid-state dye-sensitized solar cells employing hole transport material (HTM), 2,2',7,7'-tetrakis-(N,N-di-p-methoxyphenyl-amine)-9,9'-spirobifluorene (spiro-MeOTAD), has been investigated in terms of HTM overlayer thickness. Two important parameters, soak time and spin-coating rate, are varied to control the HTM thickness. Decrease in the period of loading the spiro-MeOTAD solution on $TiO_2$ layer (soak time) leads to decrease in the HTM overlayer thickness, whereas decrease in spin-coating rate increases the HTM overlayer thickness. Photocurrent density and fill factor increase with decreasing the overlayer thickness, whereas open-circuit voltage remains almost unchanged. The improved photocurrent density is mainly ascribed to the enhanced charge transport rate, associated with the improved charge collection efficiency. Among the studied HTM overlayer thicknesses, ca. 230 nm-thick HTM overlayer demonstrates best efficiency of 4.5% at AM 1.5G one sun light intensity.

• Asian Journal of Atmospheric Environment
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• 제10권4호
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• pp.190-196
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• 2016

The objective of this study is to obtain the optimal conditions to remove hydrogen fluoride (HF) generated from a variety of F-gas treatment processes. First, we selected $Ca(OH)_2$ and $CaCO_3$ as a reactant among the various alkali salts which have a high removal efficiency and a competitive price by forming a calcium fluoride precipitate. Additionally, various factors were investigated to improve the removal efficiency of HF. The conditions such as the settling time, agitating time and intensity, reaction temperature, and pH were considered as main factors. As a result, in the treatment process to remove HF through Ca-based alkali salts, the optimal conditions were a 120 min settling time, 30 min of agitation at 100 rpm, a pH of 4-8, and a reaction temperature of $40^{\circ}C$.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2011년도 춘계학술대회 초록집
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• pp.67.1-67.1
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• 2011

Knowledge of the solar radiation components and classified wavelength are essential for modeling many solar energy systems. This is particularly the case for applications that concentrate the incident energy to attain high photo-dynamic efficiency achievable only at the higher intensities. In order to estimate the performance of concentrating solar systems, it is necessary to know the intensity of the beam radiation, as only this components can be concentrated, and The new solar system can generate electricity from ultraviolet and infrared light as well as visible light. The Korea Institute of Energy Research(KIER) has began collecting solar radiation components data since January, 1988, and solar radiation classified wavelength data since November, 2008. KIER's solar radiation components and classified wavelength data will be extensively used by concentrating solar system users or designers as well as by research institutes.

• 한국태양에너지학회 논문집
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• 제22권3호
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• pp.11-20
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• 2002

This paper proposed a MPPT(Maximum Power Point Tracking) control algorithm for PV(Photovoltaic) array based on a modified constant voltage control MPPT algorithm at low insolation. This method which combined a reference voltage control and a constant voltage control algorithm. In contrast to the typical conventional MPPT algorithm, the proposed method have been obtained high efficiency and good performance in all insolation intensity. The proposed algorithm is verified through simulation and experiment.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.1043-1048
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• 2006

This paper aimed to verify and develop lighting design data for offices in Korea. It focused on a Korean standard office value relative to lighting density and the evaluation of lighting energy and cooling load. When planning indoor lighting design, we generally utilize the lighting density value which is set $14W/m^2$ by the ASHRAE/IES standard office value. However, the value is not appropriate to apply in Korea where higher efficiency lamps are more popular than others. For calculation of a proper lighting density of Korea, we analysed distribution curves of luminous intensity(2-lamp fluorescent lighting fixture with Parabolic) and derived the new lighting density $12.64W/m^2$ as Korea standard office value. In the simulation using this value, it was shown that lighting energy and cooling load could be reduced.

• 전기학회논문지P
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• 제60권4호
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• pp.236-240
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• 2011

Currently one of the most importance issues in industrial sector is energy cost and energy efficiency. The manufacturing plants especially have made many efforts to reduce energy cost by implementing maintenances. But in many cases, they are not aware that how much energy could be saved more. If we know the best energy consumption, which signifies energy baseline, we can control the intensity of maintenances. One way to obtain the baseline is using proper statistics from a specific plant, a sector of industry. Energy bandwidth signifies the gap between actual Specific Energy Consumption(SEC) of a certain plant and minimum SEC of the best plant, and estimate energy saving potential(ESP) is a result of bandwidth analysis. We chose a model plant and implemented some maintenance for a year, and then we obtained ESP. Additionally we could determine the decreased amount of carbon emissions from the plant using Carbon Emissions Factor(CEF) by Intergovernmental Panel on Climate Change(IPCC).

• 한국복합재료학회:학술대회논문집
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• 한국복합재료학회 2002년도 추계학술발표대회 논문집
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• pp.269-272
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• 2002

UV curing technology becomes important in various sectors of applications due to the high efficiency, environmental protection, and saving of energy. The effect of different proportion of vinylester (VE) and unsaturated polyester (UP) for VE/UP blend system was investigated in context of mechanical properties. The compositions of VE/UP blend were varied within 0:100, 20:80, 40:60, 60:40, 80:20, and 100:0 by weight percent. 1 wt% 1-hydroxy-cyclohexyl-phenyl-ketone was used as photoinitiator. The used intensity of UV light was in the range of $40~70 mW/\textrm{cm}^2$. The flexural strength of vinylester was not sensitive to the intensity of UV light. But the unsaturated polyester was very sensitive to the intensity of UV light. The flexural strength of vinylester was always superior to that of unsaturated polyester. The addition of the vinylester increased the flexural strength of blend system.

• 자원ㆍ환경경제연구
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• 제20권2호
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• pp.255-289
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• 2011

본 논문은 2000년, 2005년, 2008년의 3개년을 대상으로 접속불변에너지산업연관표(76개의 산업분류)를 작성하여 집계통계와 함께 산업별 미시적 통계를 제시하고, 이를 이용하여 산업별로 에너지소비량의 변화에 영향을 미치는 요인과 그 크기를 분석하였다. 본 논문에서 부가가치 총액 변화, 부가가치비중 변화, 산출구조 변화, 에너지원단위 변화의 4가지 요인을 고려하였다. 분석모형으로는 우리나라가 수출주도형의 산업구조를 갖고 있다는 점을 고려하여 공급측 모형을 이용한 구조분해분석을 적용하였다. 집계통계를 이용한 분석결과에 따르면 시기에 상관없이 부가가치 총액 변화는 에너지소비량을 증가시켰지만, 산출구조 변화는 에너지소비 변화량을 감소시켰다. 부가가치비중 변화와 에너지원단위 변화에서는 시기별로 에너지소비 변화량의 증감이 반대로 도출되었다. 산업별 통계를 이용한 결과에 따르면 부가가치비중 변화는 시점과 상관없이 전자기기에서 에너지소비 변화량을 증가시키고, 석유제품, 시멘트, 석탄제품에서 에너지소비량을 감소시켰다. 그리고 에너지원단위 변화는 석유제품, 화력, 사업서비스, 금융 및 보험, 보관 및 운수관련서비스에서의 에너지원단위 변화가 에너지소비 변화량을 증가시켰다. 이상의 결과처럼 집계통계를 이용하면 각 산업에서의 현상이 나타나지 않는다. 정부가 정책을 입안하고 시행할 때에 집계통계만을 기준으로 하면 효율적 성과를 거두기 어렵다.