• Title/Summary/Keyword: Semi-industrial Area

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Investigation on a Haze Episode of Fine Particulate Matter using Semi-continuous Chemical Composition Data (준 실시간 화학적 조성자료를 이용한 미세입자 연무 에피소드 규명)

  • Park, Seung-Shik;Kim, Sun-Jung;Gong, Bu-Joo;Lee, Kwon-Ho;Cho, Seog-Yeon;Kim, Jong-Choon;Lee, Suk-Jo
    • Journal of Korean Society for Atmospheric Environment
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    • v.29 no.5
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    • pp.642-655
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    • 2013
  • In this study, semi-continuous measurements of $PM_{2.5}$ mass, organic and elemental carbon (OC and EC), black carbon (BC), and ionic species concentrations were made for the period of April 03~13, 2012, at a South Area Supersite at Gwangju. Possible sources causing the high concentrations of major chemical species in $PM_{2.5}$ observed during a haze episode were investigated. The measurement results, along with meteorological parameters, gaseous pollutants data, air mass back trajectory analyses and PSCF (potential source contribution function) results, were used to study the haze episode. Substantial enhancements of OC, EC, BC, $K^+$, $SO{_4}^{2-}$, $NO{_3}{^-}$, $NH{_4}{^+}$, and CO concentrations were closely associated with air masses coming from regions of forest fires in southeastern China, suggesting likely an impact of the forest fires. Also the PSCF maps for EC, OC, $SO{_4}^{2-}$, and $K^+$ demonstrate further that the long-range transport of smoke plumes of forest fires detected over the southeastern China could be a possible source of haze phenomena observed at the site. Another possible source leading to haze formation was likely from photochemistry of precursor gases such as volatile organic compounds, $SO_2$, and $NO_2$, resulting in accumulation of secondary organic aerosol, $SO{_4}^{2-}$ and $NO{_3}{^-}$. Throughout the episode, local wind directions were between 200 and $230^{\circ}C$, where two industrial areas are situated, with moderate wind speeds of 3~5 m/s, resulting in highly elevated concentration of $SO_2$ with a maximum of 15 ppb. The $SO{_4}^{2-}$ peak occurring in the afternoon hours coincided with maximum ambient temperature ($24^{\circ}C$) and ozone concentration (~100 ppb), and were driven by photochemistry of $SO_2$. As a result, the pattern of $SO{_4}^{2-}$ variations in relation to wind direction, $SO_2$ and $O_3$ concentrations, and the strong correlation between $SO_2$ and $SO{_4}^{2-}$ ($R^2=0.76$) suggests that in addition to the impact of smoke plumes from forest fires in the southeastern China, local $SO_2$ emissions were likely an important source of $SO{_4}^{2-}$ leading to haze formation at the site.

A Study on Numerical Calculations of Hybrid Air Pollution Control System Coupled with SDR and Bag Filter(II) -Structural Improvement (반건식 반응기와 백필터를 결합한 하이브리드 대기오염제어 시스템의 수치해석적 연구(II) -구조개선을 중심으로)

  • Kim, Jin-Uk;Jung, Yu-Jin;Yoo, Jeong-Kun;Shon, Byung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.2
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    • pp.985-992
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    • 2011
  • The 3D computational fluid dynamics (CFD) was performed in relation to the internal fluid characteristics and flow distribution for the development of the most optimal model in the complex post-disposal device. As it is expected that a channeling (drift) would be made by the semi-dry reactor due to the large difference in the flow distribution by the compartment in the bag filter, a structural improvement should be urgently made for more uniformed flow distribution in the bag filter. Three types of modifications such as i) changing the plenum shape, ii) orifice install in the exit part of cleaned gas, iii) increasing the plenum number were established. From the results of computational fluid dynamics, it was revealed that the changing of plenum shape and orifice install in the exit part of cleaned gas was more reasonable than the increasing the plenum number because of the difficulties of retrofit. The complex post-disposal device, modified and supplemented with this analysis, integrated the semi-dry reactor and the bag filter in a single body, so it follows that the improvement can make the device compact, save the installation area, save the operation fee, and management more convenient.

A Study on Numerical Calculations of Hybrid Air Pollution Control System Coupled with SDR and Bag Filter (반건식 반응기와 백필터를 결합한 하이브리드 대기오염제어 시스템의 수치해석적 연구(I))

  • Kwon, Young-Hyun;Kim, Jin-Uk;Jung, Yu-Jin;Kim, Min-Choul;Lee, Jae-Jeong;Lee, Gang-Woo;Shon, Byung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.11
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    • pp.4656-4663
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    • 2010
  • In this study, the 3D computational fluid dynamics (CFD) was performed in relation to the internal fluid characteristics, flow distribution, air mean ages, and residence time for the development of the most optimal model in the complex post-disposal device. As it is expected that a channeling (drift) would be made by the semi-dry reactor due to the large difference in the flow distribution by the compartment in the bag filter, a structural improvement should be urgently made for more uniformed flow distribution in the bag filter. In addition, it showed the possibility that the velocity field and distribution characteristics of the residence time could be improved through a modification to inlet structure of the spray dryer reactor. The complex post-disposal device, modified and supplemented with this analysis, integrated the semi-dry reactor and the bag filter in a single body, so it follows that the improvement can make the device compact, the installation area, the operation fee, and management more convenient.

Estimation of PM10 Source Contributions on Three Cities in the Metropolitan Area by Using PMF Model (PMF 모델을 이용한 수도권 내 3개 도시에서의 PM10 오염원의 기여도 추정)

  • Lee, Tae-Jung;Huh, Jong-Bae;Yi, Seung-Muk;Kim, Shin-Do;Kim, Dong-Sool
    • Journal of Korean Society for Atmospheric Environment
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    • v.25 no.4
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    • pp.275-288
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    • 2009
  • The Korean government strengthened the environmental polices to manage and enhance Metropolitan Area air quality, and also has enforced "Special Act on Seoul Metropolitan Air Quality Improvement (SASMAQI)" issued in Dec. 2004. Recently government expanded the Seoul Metropolitan Air Quality Management District (SMAQMD) to the outskirts satellite cities of Seoul area through the "Revised Law Draft of SASMAQI". The SMAQMD has been alloted the allowable emission loads to the local governments on the basis of the carrying $PM_{10}$ capacity. However, in order to establish the effective air quality control strategy for $PM_{10}$, it is necessary to understand the corresponding sources which have a potential to directly impact ambient $PM_{10}$ concentration. To deal with the situations, many receptor methodologies have been developed to identify the origins of pollutants and to determine the contributions of sources of interests. The objective of this study was to extensively identify $PM_{10}$ sources and to estimate their contributions at the metropolitan area. $PM_{10}$ samples were simultaneously collected at the 3 semi-industrialized local cities in the Seoul metropolitan area such as Hwasung-si, Paju-si, and Icheon-si sites from April 15 to May 31, 2007. The samples collected on the teflon membrane filter by one $PM_{10}$ cyclone sampler were analyzed for trace metals and soluble ions and samples on the quartz fiber filter by another sampler were analyzed for OC and EC. Source apportionment study was then performed by using a positive matrix factorization (PMF) receptor model. A total of 6 sources were identified and their contributions were estimated in each monitoring site. Contribution results on Hwasung, Paju, and Icheon sites were as follows: 33%, 27%, and 27% from soil source, 26%, 26%, and 21% from secondary aerosol source, 11%, 11%, and 12% from biomass burning, 12%, 6%, and 5% from sea salt, 7%, 15%, and 19% from industrial related source, and finally 11%, 15%, and 16% from mobile and oil complex source, respectively. This study provides information on the major sources affecting air quality in the receptor sites and thus it will help to manage the ambient air quality in the metropolitan area by establishing reasonable control strategies, especially for the anthropogenic emission sources.

An Efficiency Improvement of Secondary-Side Rectifier for Minimizing 2nd Coil-Making in Contact-less Power Supply (비접촉 전원공급 시 2차측 코일 제작을 줄이기 위한 2차측 정류부 효율 개선에 관한 연구)

  • Yu, Joo-Hee;Kim, Choon-Sam;Sung, Won-Ki
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.3
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    • pp.1302-1307
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    • 2011
  • The Spiral coil is made considering primary, secondary side coil inductance, turn number, size, thickness, and shielding area with the litz wire-type in case of manufacturing a coil, and at this time, the semi-automation winding machine is used. When deciding on primary and secondary side coil specification and manufacturing a coil, the spiral coil of a specification varied in the various litz wire of a specification is required, and at this time, a difficulty is generated by the manufacture cost, period which during, and failure the manufacture is generated in the coil sample making. A difficulty is in the desired coil quality control of a specification. Since improving the rectifier of the secondary side in order to improve this kind of problem, the range of the coil design and the during the manufacture, various coil manufacture specifications can be comprehensively made.

Modified Pharmacokinetic/Pharmacodynamic model for electrically activated silver-titanium implant system

  • Tan, Zhuo;Orndorff, Paul E.;Shirwaiker, Rohan A.
    • Biomaterials and Biomechanics in Bioengineering
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    • v.2 no.3
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    • pp.127-141
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    • 2015
  • Silver-based systems activated by low intensity direct current continue to be investigated as an alternative antimicrobial for infection prophylaxis and treatment. However there has been limited research on the quantitative characterization of the antimicrobial efficacy of such systems. The objective of this study was to develop a semi-mechanistic pharmacokinetic/pharmacodynamic (PK/PD) model providing the quantitative relationship between the critical system parameters and the degree of antimicrobial efficacy. First, time-kill curves were experimentally established for a strain of Staphylococcus aureus in a nutrientrich fluid environment over 48 hours. Based on these curves, a modified PK/PD model was developed with two components: a growing silver-susceptible bacterial population and a depreciating bactericidal process. The test of goodness-of-fit showed that the model was robust and had good predictability ($R^2>0.7$). The model demonstrated that the current intensity was positively correlated to the initial killing rate and the bactericidal fatigue rate of the system while the anode surface area was negatively correlated to the fatigue rate. The model also allowed the determination of the effective range of these two parameters within which the system has significant antimicrobial efficacy. In conclusion, the modified PK/PD model successfully described bacterial growth and killing kinetics when the bacteria were exposed to the electrically activated silver-titanium implant system. This modeling approach as well as the model itself can also potentially contribute to the development of optimal design strategies for other similar antimicrobial systems.

A Study on the Environmental Changes in the 4th Industrial Revolution Era and the Strategic Response Priority of SMEs (제4차 산업혁명 시대의 환경변화와 중소규모 기업의 전략적 대응 우선순위)

  • Sohn, Seyung-Hee
    • Korean small business review
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    • v.41 no.3
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    • pp.151-172
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    • 2019
  • The changes in the 4th industrial revolution era are not limited to specific sectors, but affect all sectors of industry. Thus all companies are required to respond effectively to changes. Some companies response by adopting cutting-edge ICT and some companies improve the organizational structure, or enhance the competence of individual employees. This study is based on the assumption that the responses to the change in the 4th industrial revolution era should not be uniform, and that the response strategies and priorities should vary according to the characteristics of the companies. The purpose of this study is to suggest both different response strategies and the priority of the responding factors(areas) to small and medium-sized enterprises. Data were collected through the semi-Delphi method. As a result of data analysis, the priorities of the medium-sized enterprises were as follows: introduction of IT-strengthening the competence of the individuals - establishing technology infrastructure-improving organizational structure - efficiency of work - improving organizational culture. While the priorities of the response factors(area) of the small-sized companies were as follows: strengthening the competence of the individuals - efficiency of work - introduction of IT - establishing technology infrastructure - improving organizational structure - improving organizational culture.

An Analysis on the Mechanism and Algorism of ET·IT Based Future City Space (환경기술과 정보기술 기반의 미래도시 공간 메커니즘과 알고리즘 분석)

  • Han, Ju-Hyung;Lee, Sang-Ho
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.3
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    • pp.296-305
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    • 2017
  • This study aims to create a new urban space through mechanism structure and algorism analysis between IT and ET. The results are as follows. First, the development trends of ET IT are classified into 4 types, "Eco-Friendly Development", "Energy Production Technology Development", "Energy Saving Technology Development" and "Wide Area IT Network Development", which are found to be constantly evolving. Second, Sang-Am DMC developed through the environmentally protective and eco-friendly aspects of ET from the Korean War to 1978. Wide area IT networks developed rapidly from 1990 to 2000. However, in 2010, urban spaces began to develop by the fusion of the Environment and Information. The fusion of Environment and Information in the development trends in the past is referred to as "Individual Development", that in the present is referred to as "Semi-fusion Development" and that in the future will be referred to as "Total Fusion Development". Third, the mechanism structure of DMC has evolved through creation, extinction and fusion processes. The creation process will serve to supplement the insufficiencies of the existing systems, the extinction process will be the compactification of the fusion process, and the fusion process will be the standard for creation and extinction. Finally, the future of new innovative urban and architectural spaces will be forged by the mechanism symbolization patterns of IT ET.

A Study on Development of Damage Impact Distance Calculation Formula to Determine Evacuation and Notification of Residents in Case of Ammonia Release Accident (암모니아 누출사고 시 주민대피 및 알림 결정을 위한 피해영향거리 산정식 개발 연구)

  • Kim, Hyun-Sub;Jeon, Byeong-Han;Lee, Myeong-Ji;Yun, Jeong-Hyeon;Lee, Hyun-Seung;Jung, Woong-Yul;Jo, Jeong-A
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.10
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    • pp.308-316
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    • 2020
  • This study attempted to derive an equation for calculating the damage impact distance using CARIS so that local governments can quickly determine evacuation and notification of residents in the event of an ammonia-release accident. Ammonia is an accident-causing substance and one of 16 substances to prepare for resident evacuation. It is the most frequently occurring chemical with 58 chemical accidents from 2014~2019. The study derives an equation for calculating the damage impact distance according to the exposure time of ammonia based on AEGL, an acute exposure standard applicable to the general population, which is includes vulnerable groups such as infants, children and the elderly and designated by the EPA. The calculation formulas for each concentration and exposure time to classify the hazardous area according to AEGL-3 and the semi-dangerous area according to AEGL-2 were derived. A comparison of the relative standard deviation between the damage impact distance values of CARIS revealed that is was in the range of 0~2%. Local governments should consider the actual accident situation and apply the appropriate damage-affected distance calculation formula derived from the study to evacuate residents near the origin of the accident or use for protective measures such as indoor evacuation notification.

Recent Progress in Air-Conditioning and Refrigeration Research: A Review of Papers Published in the Korean Journal of Air-Conditioning and Refrigeration Engineering in 2014 (설비공학 분야의 최근 연구 동향: 2014년 학회지 논문에 대한 종합적 고찰)

  • Lee, Dae-Young;Kim, Sa Ryang;Kim, Hyun-Jung;Kim, Dong-Seon;Park, Jun-Seok;Ihm, Pyeong Chan
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.27 no.7
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    • pp.380-394
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    • 2015
  • This article reviews the papers published in the Korean Journal of Air-Conditioning and Refrigeration Engineering during 2014. It is intended to understand the status of current research in the areas of heating, cooling, ventilation, sanitation, and indoor environments of buildings and plant facilities. Conclusions are as follows. (1) The research works on the thermal and fluid engineering have been reviewed as groups of heat and mass transfer, cooling and heating, and air-conditioning, the flow inside building rooms, and smoke control on fire. Research issues dealing with duct and pipe were reduced, but flows inside building rooms, and smoke controls were newly added in thermal and fluid engineering research area. (2) Research works on heat transfer area have been reviewed in the categories of heat transfer characteristics, pool boiling and condensing heat transfer and industrial heat exchangers. Researches on heat transfer characteristics included the results for thermal contact resistance measurement of metal interface, a fan coil with an oval-type heat exchanger, fouling characteristics of plate heat exchangers, effect of rib pitch in a two wall divergent channel, semi-empirical analysis in vertical mesoscale tubes, an integrated drying machine, microscale surface wrinkles, brazed plate heat exchangers, numerical analysis in printed circuit heat exchanger. In the area of pool boiling and condensing, non-uniform air flow, PCM applied thermal storage wall system, a new wavy cylindrical shape capsule, and HFC32/HFC152a mixtures on enhanced tubes, were actively studied. In the area of industrial heat exchangers, researches on solar water storage tank, effective design on the inserting part of refrigerator door gasket, impact of different boundary conditions in generating g-function, various construction of SCW type ground heat exchanger and a heat pump for closed cooling water heat recovery were performed. (3) In the field of refrigeration, various studies were carried out in the categories of refrigeration cycle, alternative refrigeration and modelling and controls including energy recoveries from industrial boilers and vehicles, improvement of dehumidification systems, novel defrost systems, fault diagnosis and optimum controls for heat pump systems. It is particularly notable that a substantial number of studies were dedicated for the development of air-conditioning and power recovery systems for electric vehicles in this year. (4) In building mechanical system research fields, seventeen studies were reported for achieving effective design of the mechanical systems, and also for maximizing the energy efficiency of buildings. The topics of the studies included energy performance, HVAC system, ventilation, and renewable energies, piping in the buildings. Proposed designs, performance performance tests using numerical methods and experiments provide useful information and key data which can improve the energy efficiency of the buildings. (5) The field of architectural environment was mostly focused on indoor environment and building energy. The main researches of indoor environment were related to the evaluation of work noise in tunnel construction and the simulation and development of a light-shelf system. The subjects of building energy were worked on the energy saving of office building applied with window blind and phase change material(PCM), a method of existing building energy simulation using energy audit data, the estimation of thermal consumption unit of apartment building and its case studies, dynamic window performance, a writing method of energy consumption report and energy estimation of apartment building using district heating system. The remained studies were related to the improvement of architectural engineering education system for plant engineering industry, estimating cooling and heating degree days for variable base temperature, a prediction method of underground temperature, the comfort control algorithm of car air conditioner, the smoke control performance evaluation of high-rise building, evaluation of thermal energy systems of bio safety laboratory and a development of measuring device of solar heat gain coefficient of fenestration system.