• 한국물환경학회지
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• 제33권6호
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• pp.650-660
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• 2017

In this study, pollutant emission characteristics by water damage period analyzed 11 items (water temperature, pH, DO, EC, BOD, COD, TOC, SS, T-N, T-P and flow) with load duration curve, time series load curve and factor analysis for three years (2014-2016). Load duration curve is applied to judge the level of impaired waterbody and estimate impaired level by pollutants such as BOD and T-P in this study depending on variation of stream flow. Water quality standard exceeded the flow of mid-range and low-range by flow condition evaluation using load duration curve. This watershed was influenced by point source more than non-point source. Cumulative excess rate of BOD and T-P kept water quality standard for all seasons (spring, summer, autumn and winter) except BOD 59% in spring. Water quality changes were influenced by pollutants of basic environmental treatment facilities and agricultural areas during spring and summer. Results of factor analysis were classified commonly first factor (BOD, COD, and TOC) and second factor (flow, water temperature and SS). Therefore, effects of artificial pollutants and maintenance water must be controlled seasonally and reduced relative to water damage caused by point pollution sources with effluent standard strengthened in the target watershed.

• 동력기계공학회지
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• 제12권1호
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• pp.13-19
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• 2008

In this study, a variable induction and exhaust system is applied to turbocharged diesel engine to improve the volumetric efficiency, especially, in a low and transient engine speed range where much of the pollutant matters are expelled out. The volumetric efficiency is known as one of the most important factor which affects significantly engine performance, fuel economy and further emission and noise level. As the torque increase with the engine speed up, the gas flow in an exhaust pipe become pulsating and then has an effect on boost up capacity of air charging into the cylinder and expelling capacity to atmosphere simultaneously. But at a low and idling speed, the pulsation effect was not so significant. Accordingly, resonator was employed to compensate their loss. The variable induction system consists of the secondary pipe, resonator, intercooler, and torque variance were examined with extended operating conditions. In the mean time, for interpretation and well understanding for the phenomena of wave action that arising during intake and exhaust process between turbocharger and variable intake system, the concept of the combined supercharging was introduced. Some of results are depicted which deal with a pressure history during valve events of induction process. Consequently, by the governing of these phase and amplitude of pulsating wave, it enables us to estimate and evaluate for the intake system performance and also, designing stage of the system layout.

• Asian Journal of Atmospheric Environment
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• 제7권1호
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• pp.25-37
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• 2013

Open biomass burning (excluding biofuels) is an important contributor to air pollution in the Asian region. Estimation of emissions from fires, however, has been problematic, primarily because of uncertainty in the size and location of sources and in their temporal and spatial variability. Hence, more comprehensive tools to estimate wildfire emissions and that can characterize their temporal and spatial variability are needed. Furthermore, an emission processing system that can generate speciated, gridded, and temporally allocated emissions is needed to support air-quality modeling studies over Asia. For these reasons, a biomass-burning emissions modeling system based on satellite imagery was developed to better account for the spatial and temporal distributions of emissions. The BlueSky Framework, which was developed by the USDA Forest Service and US EPA, was used to develop the Asian biomass-burning emissions modeling system. The sub-models used for this study were the Fuel Characteristic Classification System (FCCS), CONSUME, and the Emissions Production Model (EPM). Our domain covers not only Asia but also Siberia and part of central Asia to assess the large boreal fires in the region. The MODIS fire products and vegetation map were used in this study. Using the developed modeling system, biomass-burning emissions were estimated during April and July 2008, and the results were compared with previous studies. Our results show good to fair agreement with those of GFEDv3 for most regions, ranging from 9.7 % in East Asia to 52% in Siberia. The SMOKE modeling system was combined with this system to generate three-dimensional model-ready emissions employing the fire-plume rise algorithm. This study suggests a practicable and maintainable methodology for supporting Asian air-quality modeling studies and to help understand the impact of air-pollutant emissions on Asian air quality.

• 한국추진공학회지
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• 제6권2호
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• pp.29-36
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• 2002

두 번째 벤츄리 끝단 각도가 가스터빈 연소기의 유동 및 분무 특성에 미치는 영향을 이해하기 위해 스월 vane 형태의 2중 스월컵을 장착한 산업용 가스터빈 엔진에 대해 두 번째 벤츄리 끝단 각이 수렴형, 직선형, 발산형의 세 경우에 대해 실험을 수행하였다. 두 번째 벤츄리 끝단 각도의 변화가 가스터빈 연소기의 재순환 영역의 위치, 크기 및 형상 등의 유동 특성과 연료 액적 분무 형태를 크게 변화시킴을 확인 할 수 있었다. 발산형 벤츄리에서는 내부 재순환 영역이 점화가 일어나는 지점에서 가까운 곳에서 형성되므로 화염의 안정화에는 탁월할 것으로 판단되지만, 수렴형 벤츄리에서 가장 작고 균일한 크기의 액적들이 측정되었고, 내부 재순환 영역이 연소기 내에 길게 형성된 점으로 고효율, 저공해 연소기로는 수렴형 벤츄리의 경우가 적합하리라 판단된다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.254-257
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• 2017

본 논문에서는 항공 가스 터빈용 연소기 개발을 위한 단일 연소기 섹터 시험 결과에 대한 논의하였다. 연소기로 공급되는 전체 공기 중 주 연소 영역으로 공급되는 공기비율을 변화 시키면서 배출물 농도, 라이너 표면 온도 분포 및 연소기 출구 온도 패턴 등의 연소 성능 변화를 연구하였다. 주 연소 공기량이 증가함에 따라 CO와 NOx 배출 농도가 증가하는 경향이 있었으며, 연소기 출구 패턴은 개선되는 것으로 나타났다. 희석 공기공을 회전시켜 배치하는 경우 연소기 출구 온도 패턴의 변화가 민감하게 변하는 것을 확인하였다. 이러한 연구 결과는 연소기의 효율, 내구성 및 배출물 감소 성능을 고려한 연소기 라이너 설계 최적화 과정의 기초 자료로 활용할 예정이다.

• 한국건설관리학회논문집
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• 제18권5호
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• pp.68-76
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• 2017

최근 이슈가 되고 있는 미세먼지(fine dust)는 직경이 $10{\mu}g/m^3$이하인 미립자물질(particulate matter)로서, 흡입 시 인체에 치명적인 악영향을 주는 오염물질로 분류되어 있다. 미세먼지가 바람에 날려 비산할 때 주변에 끼치는 악영향이 증가하므로, 이러한 비산먼지(fugitive dust)를 잘 통제해야 한다. 특히 건설업은 한국에서 가장 비산먼지를 많이 배출하는 사업 분야이므로, 건설현장에서 배출되는 비산먼지를 잘 관리하는 것이 국내 미세먼지의 문제를 해결하는 중요사안이 될 수 있다. 그러나 현재 국내의 비산먼지 관련 민원 수중 건설업이 가장 큰 비율을 차지하고 있는 실태로 보아, 국내의 건설현장 비산먼지 배출에 대한 제도적인 관리에 대한 점검이 필요하다. 이에 본 논문에서는 국내외 주요도시별 건설현장에 적용되는 비산먼지 규정을 비교분석한 뒤, 도출한 개선안을 제안하여 국내 건설현장 비산먼지의 제도적 관리에 일조하고자 한다.

• Carbon letters
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• 제18권
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• pp.49-55
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• 2016

Refuse-derived fuel (RDF) produced using municipal solid waste was pyrolyzed to produce RDF char. For the first time, the RDF char was used to remove aqueous copper, a representative heavy metal water pollutant. Activation of the RDF char using steam and KOH treatments was performed to change the specific surface area, pore volume, and the metal cation quantity of the char. N₂ sorption, Inductively Coupled Plasma-Atomic Emission Spectrometer (ICP-AES), and Fourier transform infrared spectroscopy were used to characterize the char. The optimum pH for copper removal was shown to be 5.5, and the steam-treated char displayed the best copper removal capability. Ion exchange between copper ions and alkali/alkaline metal cations was the most important mechanism of copper removal by RDF char, followed by adsorption on functional groups existing on the char surface. The copper adsorption behavior was represented well by a pseudo-second-order kinetics model and the Langmuir isotherm. The maximum copper removal capacity was determined to be 38.17 mg/g, which is larger than those of other low-cost char adsorbents reported previously.

• 한국전기전자재료학회논문지
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• 제31권6호
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• pp.417-421
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• 2018

$TiO_2$ has excellent photocatalytic properties and several studies have reported the increase in its specific surface area. The structure of $TiO_2$ nanofibers indicates promising improved photocatalytic properties and these nanofibers can thus potentially be applied in air pollution sensors and pollutant removal filters. In this study, a $TiO_2$ nanofiber was fabricated by the electrospinning method. The fabrication processing factors such as the applied voltage, the distance between nozzle and collector, and the inflow rate of solution were controlled. The precursor was titanium (IV) isopropoxide and as-spun $TiO_2$ nanofibers were heated at $450^{\circ}C$ for 2 h to obtain an anatase crystalline structure. The microstructure was analyzed using field emission scanning electron microscope (FE-SEM) and X-ray diffraction analysis (XRD). The anatase phase was observed in the $TiO_2$ nanofibers after heat treatment. The diameter of $TiO_2$ nanofibers increased with the flow rate, but decreased with decreasing applied voltage and nozzle to collector distance. The diameter of $TiO_2$ nanofibers was controlled in the range of 364 nm to 660 nm. These nanofibers are expected to be very useful in photocatalytic applications.

• 한국실내디자인학회논문집
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• 제17권3호
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• pp.23-33
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• 2008

After the concept of apartments was introduced in 1960s in Korea, on account of the development of architectural technology and science, high-rise residences in Korea are getting higher, and these residences have been becoming high-rise commercial/residential buildings since 1990. Nowadays, as the construction of high-rise commercial residential building complex is booming, the difference between these complex and high-rise apartments is getting smaller, and these two kind of high-rise residences are becoming new residential style in Korea. And these high-rise residences are considered the symbol of wealth owing to the marketing strategy emphasizing high quality, refined interior, a fair view, and the protection of privacy. However, high-rise residences bring about many problems related to health and psychology caused by the consumption of a large amount of energy, pollutant emission, the deterioration of the quality of indoor air, and vibration. For this reason, in this study, we tried to emphasize the necessity of environment-friendly access to provide healthy living environment and to reduce the negative effect of housing life in high-rise residences, and find the method to improve environment-friendly quality and health of residents in interior space. Therefore, this study aims to detect the problems and the items to be improved of interior spaces of high-rise residences by quantitative, qualitative analysis of the evaluation elements and the floor planning elements deduced from environment-friendly architectural certification in Korea and the other countries, and suggest the guideline to improve the environment-friendly quality of these interior spaces.

• 한국농공학회논문집
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• 제63권3호
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• pp.97-105
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• 2021

Most of the rural development projects for the welfare of residents are mainly new construction and remodeling projects for community buildings such as village halls and senior citizens. However, in the case of the construction industry, it has been studied that 23% of the total carbon dioxide emissions generated in Korea are generated in the building-related sector. (GGIC, 2015) In order to reduce the emission of environmental pollutants resulting from construction of rural community buildings, there is a need to establish a system for rural buildings by predicting the environmental impact. As a result of this study, the emissions of air pollutants from buildings in rural communities were analyzed by dividing into seven stages: material production, construction, operation, maintenance, demolition, recycling, and transportation activities related to disposal. As a result, 12 kg of carbon dioxide (CO), 0.06 kg of carbon monoxide (CO), 0.02 kg of methane (CH), 0.04 kg of nitrogen oxides (NO), 0.02 kg of sulfurous acid gas (SO), and non-methane volatile organics per 1m of buildings in rural communities It was analyzed that 0.02 kg of compound (NMVOC) and 0.00011 kg of nitrous oxide (NO) were released. This study proved that environmentally friendly design is possible with a quantitative methodology for the comparison of operating energy and air pollutant emissions through the design specification change based on the statement of the rural community building. It is considered that it can function as basic data for further research by collecting major structural changes and materials of rural community buildings.