• Title/Summary/Keyword: Urban air quality

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A Study on the Thermal Load Patterns for a Exterior Wall in a House According to a Variation of Earth Sheltering Thickness (복토 주택의 외벽면 복토 두께 변화에 따른 열부하 패턴에 관한 연구)

  • Lee, Jae-Hyuk;Choi, Won-Ki;Suh, Seung-Jik;Cho, Dong-Woo
    • Proceedings of the SAREK Conference
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    • 2008.06a
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    • pp.807-812
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    • 2008
  • The various attempts is made to solve the energy and environment problems. In addition, people interested in their life quality want the more eco-friendly living space. So we suggested that the earth-sheltered house could be one of the eco-friendly and low energy consuming houses to meet the social interest. And we also made data for design of the earth-sheltered house to be applicable to climate of Korea. In this study, a simulation was performed to estimate a boundary temperature according to earth sheltering thickness at the earth-sheltered part(exterior wall) in the case of earth sheltering on the plane ground not using a sloped site. And we analyzed the reduction of a thermal load by using this boundary temperature. We also compared a case of earth sheltering at the vertical wall with a case of earth sheltering at the roof to know the thermal reduction effect of a case of earth sheltering at the vertical wall.

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Energy Saving Potentials of Ventilation Controls Based on Real-time Vehicle Detection in Underground Parking Facilities

  • Cho, Hong-Jae;Park, Joon-Young;Jeong, Jae-Weon
    • International Journal of High-Rise Buildings
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    • v.2 no.4
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    • pp.331-340
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    • 2013
  • The main topic of this paper is to show a possibility of indoor air quality enhancement and the fan energy savings in underground parking facilities by applying the demand-controlled ventilation (DCV) strategy based on the real-time variation of the traffic load. The established ventilation rate is estimated by considering the passing distance, CO emission rate, idling time of a vehicle, and the floor area of the parking facility. However, they are hard to be integrated into the real-time DCV control. As a solution to this problem, the minimum ventilation rate per a single vehicle is derived in this research based on the actual ventilation data acquired from several existing underground parking facilities. And then its applicability to the DCV based on the real-time variation of the traffic load is verified by simulating the real-time carbon monoxide concentration variation. The energy saving potentials of the proposed DCV strategy is also checked by comparing it with those for the current underground parking facility ventilation systems found in the open literature.

Numerical Study on the Process Analysis of Ozone Production due to Emissions Reduction over the Seoul Metropolitan Area (수도권 배출량 저감에 따른 오존 발생 과정 분석에 관한 수치연구)

  • Jeong, Yeo-Min;Lee, Soon-Hwan;Lee, Hwa-Woon;Jeon, Won-Bae
    • Journal of Environmental Science International
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    • v.21 no.3
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    • pp.339-349
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    • 2012
  • In order to clarify the impact of emissions reductions on the air quality over Metropolitan area of Korean Peninsula, several numerical experiment and analysis of integrated process rate(IPR) of ozone were carried out. Numerical models used in this study are WRF for the estimate the meteorological elements and CMAQ for assessment of ozone concentration. As result in the sensitive test of VOC/NOx reduction experiments, although VOC reduction tends to induce the different impact on the advection and photochemical reaction rate of ozone in urban area and rural area, the mechanism of ozone appeared to be more sensitive to the reduction of VOC than that of NOx over the metropolitan and its surround area. So the control of VOC emission inventories is an effective means to decrease the ozone concentrations around this area.

The Distribution of Work-Life Integration against COVID-19 and its Implications: Focusing on Remote Work in Switzerland

  • CHOI, Choongik;LEE, Kwang-Hoon
    • Journal of Distribution Science
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    • v.21 no.1
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    • pp.95-105
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    • 2023
  • Purpose: This study aims to explore the distribution of work-life integration against COVID-19 and its Implications by analyzing remote work in Switzerland. Research design, data and methodology: The study performed literature review and descriptive analyses using various data such as perception surveys, statistics, and related documents. Results: The infectious disease was a turning point for many people in Switzerland by changing where and how people want to live. Since the COVID-19 crisis demonstrated that disease could be spread by proximity, negative perception about urban areas expanded, and rural areas are increasingly preferred due to fresh and clean air and a more ecological lifestyle. In addition, increased remote work, a change brought about by COVID-19, has subsequently led to changes in household habits and needs. Distance from work is no longer an important factor when someone chooses where to live. A trend is now emerging where households wanting to improve the quality of life leave the city center and move to the suburbs. Conclusions: Paradoxically, such trend accelerated by the COVID-19 crisis has an unintendedly positive impact on the distribution of work-life integration across society while providing more flexibility in terms of place and time management and lowering the burden on roads and infrastructure.

Measurement of Oxygen Saturation Concentration by Zeolite (제올라이트별 산소포화농도 측정 실험)

  • Park, Sung-Sik;Kim, Kwang-Hwan
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.2
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    • pp.617-622
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    • 2018
  • Air is essential for human beings to survive, but urban air is polluted with soot and harmful gases, due to the increase in industrial development and the population. Thus, air pollution in large cities is of increasing interest in the research community. One of the plausible solutions to this problem is supplying sufficient oxygen to indoor spaces. The main principle of the oxygen generator is to separate oxygen from air using synthetic zeolite. Various synthetic zeolites have been applied to public indoor spaces with the focus being placed on the oxygen exchange quality. Among the characteristics of zeolites which can be applied to oxygen generators is their ability to adsorb nitrogen from the air and, in this way, generate only oxygen. Thus, we investigated the degree of nitrogen adsorption by five kinds of natural zeolite and LTA zeolite 3A, 4A, and 5A (two different sizes). Using the PSA method, the higher the degree of nitrogen adsorption, the higher the oxygen saturation concentration, it was found that the nitrogen adsorption degree of the 5A zeolite was the highest. 6% on average. It was also found that the size of the zeolite had a significant effect on the degree of nitrogen adsorption.

Distribution of Airborne Hexavalent Chromium Concentrations in Large Industrial Complexes in Korea

  • Kang, Byung-Wook;Lee, Hak-Sung;Kim, Jong-Ho;Hong, Ji-Hyung;Kim, Rok-Ho;Seo, Young-Kyo;Han, Jin-Seok;Baek, Kyung-Min;Kim, Min-Ji;Baek, Sung-Ok
    • Asian Journal of Atmospheric Environment
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    • v.10 no.4
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    • pp.208-216
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    • 2016
  • This paper reports the results of a field evaluation which used sampling and analytical methods to determine the levels of airborne hexavalent chromium Cr(VI) in major industrial complexes in Korea over a seven year period (2007-2013). Cr(VI) concentrations were determined using cellulose filter sampling and ion chromatography analysis. In order to validate the analytical performance of these methods, studies were also carried out to investigate data quality control (QC) parameters, such as the method detection limit (MDL), repeatability, and recovery efficiencies. The average concentrations of Cr(VI) for the nine industrial complexes in Korea were in the range of 0.09 to $1.40ng/m^3$, which is similar to of the concentrations in other industrial areas around the world. The impacts of Cr(VI) emissions from industrial areas on Cr(VI) concentrations in neighboring-residential areas were considerably low, and the dispersion of Cr(VI) from industrial areas to residential areas was estimated to be 'not-significant'. Cr(VI) levels were not affected by seasonal variation, which suggests that chromium was emitted continuously from the industrial sources throughout the year. The concentration of Cr(VI) measured accounted for 0.7 to 9.4 percent of the total chromium level, which is a low percentage compared to those in other urban areas around the world. This is the first report in an international journal of a field study conducted in Korea to determine the concentration of Cr(VI) in the ambient air of industrial and residential areas.

Vertical Distribution and Potential Risk of Particulate Polycyclic Aromatic Hydrocarbons in High Buildings of Bangkok, Thailand

  • Pongpiachan, Siwatt
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.1865-1877
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    • 2013
  • Vertical variations of polycyclic aromatic hydrocarbon (PAH) concentrations in $PM_{10}$ were investigated in order to assess the factors controlling their behavior in the urban atmosphere of Bangkok City, Thailand. Air samples were collected every three hours for three days at three different levels at Bai-Yok Suit Hotel (site-1 and site-2) and Bai-Yok Sky Hotel (site-3) in February $18^{th}-21^{st}$, 2008. The B[a]P concentration showed a value 0.54 fold, lower than the United Kingdom Expert Panel on Air Quality Standard (UK-EPAQS; i.e. 250 pg $m^{-3}$) at the top level. In contrast, the B[a]P concentrations exhibited, at the ground and middle level, values 1.50 and 1.43 times higher than the UK-EPAQS standard respectively. PAHs displayed a diurnal variation with maximums at night time because of the traffic rush hour coupled with lower nocturnal mixing layer, and the decreased wind speed, which consequently stabilized nocturnal boundary layer and thus enhanced the PAH contents around midnight. By applying Nielsen's technique, the estimated traffic contributions at Site-3 were higher than those of Site-1: about 10% and 22% for Method 1 and Method 2 respectively. These results reflect the more complicated emission sources of PAHs at ground level in comparison with those of higher altitudes. The average values of incremental individual lifetime cancer risk (ILCR) for all sampling sites fell within the range of $10^{-7}-10^{-6}$, being close to the acceptable risk level ($10^{-6}$) but much lower than the priority risk level ($10^{-4}$).

Temporal and Spatial Distribution of Particulate Carcinogens and Mutagens in Bangkok, Thailand

  • Pongpiachan, Siwatt;Choochuay, C.;Hattayanone, M.;Kositanont, C.
    • Asian Pacific Journal of Cancer Prevention
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    • v.14 no.3
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    • pp.1879-1887
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    • 2013
  • To investigate the level of genotoxicity over Bangkok atmosphere, $PM_{10}$ samples were collected at the Klongchan Housing Authority (KHA), Nonsree High School (NHS), Watsing High School (WHS), Electricity Generating Authority of Thailand (EGAT), Chokchai 4 Police Station (CPS), Dindaeng Housing Authority (DHA) and Badindecha High School (BHS). For all monitoring stations, each sample covered a period of 24 hours taken at a normal weekday every month from January-December 2006 forming a database of 84 individual air samples (i.e. $12{\times}7=84$). Atmospheric concentrations of low molecular weight PAHs (i.e. phenanthrene, anthracene, pyrene and fluoranthene) were measured in $PM_{10}$ at seven observatory sites operated by the pollution control department of Thailand (PCD). The mutagenicity of extracts of the samples was compared in Salmonella according to standard Ames test method. The dependence of the effects on sampling time and on sampling location was investigated with the aid of a calculation of mutagenic index (MI). This MI was used to estimate the increase in mutagenicity above background levels (i.e. negative control) at the seven monitoring sites in urban area of Bangkok due to anthropogenic emissions within that area. Applications of the AMES method showed that the average MI of $PM_{10}$ collected at all sampling sites were $1.37{\pm}0.10$ (TA98; +S9), $1.24{\pm}0.08$ (TA98; -S9), $1.45{\pm}0.10$ (TA100; +S9) and $1.30{\pm}0.09$ (TA100; -S9) with relatively less variations. Analytical results reconfirm that the particulate PAH concentrations measured at PCD air quality monitoring stations are moderately low in comparison with previous results observed in other countries. In addition, the concept of incremental lifetime particulate matter exposure (ILPE) was employed to investigate the potential risks of exposure to particulate PAHs in Bangkok atmosphere.

A Study on the Air Temperature Changes and Regional Characteristics in South Korea (우리나라 지역별 기온변화 특성)

  • Kim, Tae Ryong
    • Journal of Integrative Natural Science
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    • v.2 no.2
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    • pp.131-167
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    • 2009
  • Global warming is regarded as one of the most critical issues that should be taken care of by the entire global community as it threatens the survival of mankind. South Korea, in particular, undergoes faster warming than the average rate of global warming. South Korea has revealed various warming rates and trends being surrounded by sea on three sides and having complex terrains dominated by mountains. The rates vary according to regions and their urbanization and industrialization. Differences also derive from seasons and weather elements. Changes to the highest, mean, and lowest temperature are also different according to the characteristics of regions and observatories, which is more apparent where the force of artificial weather applies. In an urban area, temperature gaps tend to decrease as the lowest temperature rises more than the highest temperature. Meanwhile, temperature gaps grow further in a coastal or country region where the force of artificial weather is small and the force of natural weather prevails. In this study, the investigator analyzed the changes to the weather elements of 11 observation spots that had gone through no changes in terms of observation environment since 1961, were consecutively observed, and had the quality of their observation data monitored on an ongoing basis. Using the results, I tried to identify natural and artificial causes affecting certain spots. Located on the east coast of the Asian Continent, South Korea sees weather changing very dynamically. Having huge influences on our weather, China has achieved very rapid industrialization for the last 30 years and produced more and more greenhouse gases and air pollution due to large-size development projects. All those phenomena affect our weather system in significant ways. Global warming continues due to various reasons with regional change differences. Thus the analysis results of the study will hopefully serve as basic data of weather statistics with which to set up countermeasures against climate changes.

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An Evaluation of Plastic and Early Dry Shrinkage of Fiber Reinforced Concrete Using Recycled Aggregate (순환잔골재를 활용한 섬유 보강 콘크리트의 소성 및 초기 건조수축평가)

  • Park, Yun-Mi;Kim, Young-Duck;Kim, Young-Sun;Kim, Ho-Dong;Kim, Gyu-Yong;Kim, Moo-Han
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.04a
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    • pp.937-940
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    • 2008
  • Recently, the recycling and reusing of construction and demolition waste concrete is urgently required because generation quantity of construction and demolition waste concrete is greatly increased according to the rapid increasing of urban redevelopment project. On the other hand, the problem solution for demand and supply unbalance of fine aggregate is urgently required because of the restriction of collecting sea fine aggregate by intensification of environment influence evaluation and the shortage of river fine aggregate. but a quality of aggregate as building structure is not demonstrated. Therefore it is the objective of this study to estimate plastic and early dry shrink crack of fiber reinforced concrete using a recycled aggregate by plat-ring test and mock-up test of exposure to the air. as a result, in case of plat- ring test, developing crack is wider using recycled aggregate concrete than natural aggregate concrete, is wider using fiber reinforced concrete than non fiber. in case of mock-up test of exposure to the air, it is similar to plat-ring test.

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