• Title/Summary/Keyword: urban air

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The Effect of the Attached Glazing and Windbreak on the Thermal Performance and Air Tightness of Sliding window (덧유리 및 방풍재 적용을 통한 슬라이딩 창의 단열 및 기밀성능 개선효과 분석)

  • Bae, Min-Jung;Kang, Jae-Sik;Choi, Gyeong-Seok;Choi, Hyung-Joung
    • KIEAE Journal
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    • v.17 no.4
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    • pp.59-65
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    • 2017
  • Purpose: Thermal performance and air tightness of window are improved for the building energy efficiency. As the deteriorated houses are increased, the improve measures with low cost and easy installation are developed in the energy performance of window. Attached glazing and windbreak can be easily applied to the window with low cost. In this paper, the effect of the attached glazing and windbreak on the thermal performance and air tightness of window is analyzed as the measure to improve performance of window. Method: Thermal transmittance of glazing is evaluated through WINDOW simulation according to thickness of attached glazing and air cavity. Based on the simulation results, thermal transmittance, air tightness and condensation resistance performance of four cases are tested according to Korea standards. One type of PVC sliding double window is chosen as the specimen. For the analysis on low performance of window, the outside of window is excluded in the PVC sliding double window. Result: This study shows that thermal performance of glazing can be increased by the application of attached glazing. Furthermore, lower thermal performance of glazing can obtain the higher effect of attached glazing. The application of attached glazing and windbreak can effect on increasing thermal performance and air tightness of window.

Numerical Simulation on the Wind Ventilation Lane and Air Pollutants Transport due to Local Circulation Winds in Daegu Districts (대구지역의 국지순환풍의 환기경로 및 대기오염수송에 관한 수치모의)

  • Koo, Hyun-Suk;Kim, Hae-Dong
    • Journal of the Korean earth science society
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    • v.25 no.6
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    • pp.418-427
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    • 2004
  • Recently, urban planning with consideration of urban climate, represented by the concept of urban ventilation lane is widely practiced in many countries. The concept of urban ventilation lane is mainly aimed to improve the thermal comfort within urban area in summer season. It has also the aim to reduce the urban air pollution by natural cold air drainage flows which are to be intensified by a suitable alignment of buildings as well as use zonings based on scientific reasons. In this study, the prevailing wind ventilation lane of a local wind circulation and around Daegu for a typical summer days was investigated by using a numerical simulation. The transport of air pollutants by the local circulation winds was also investigated by using the numerical simulation model, the RAMS (Reasonal Atmospheric Model System).The domain of interest is the vicinity of Daegu metropolitan city (about 900 km2). The horizontal scale of the area is about 30 km. The simulations were conducted under a late spring synoptic condition with weak gradient wind and almost clear sky. From the numerical experiment, the following three conclusions were obtained: (1) The major wind passages of the local circulation wind generated by radiative cooling over the representative mountains of Daegu (Mt. Palgong and Mt. Ap) were found. The winds blow down along the valley axis over the eastern part of Daegu as a gravity flow during nighttime. (2) At the flatland, the winds blow toward the western part of Daegu through the city center. (3) As the results, the air pollutants were transported toward the western part of Daegu by the winds during nighttime.

Evaluation on Effects of Acid Deposition by analysis Rainfall in the Forest (산림내 강우에 의한 산성 강하물의 영향 평가)

  • 이총규;김종갑
    • The Korean Journal of Ecology
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    • v.21 no.5_1
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    • pp.449-456
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    • 1998
  • This study was carried out to investigate the characteristics of acid deposition by stemflow, throughfall, rainfall and $SO_{2}$ in the industrial, urban and rural areas where were affected by the acid rain areas air pollution in Pinus thunbergii than Quercus spp. forest. As the stemflow pH in industrial and urban area were lowed that of rural area, the result industrial and urban, and correlation of negative ($r=-0.9415^{**}$) between pH and EC. The concentration of acid ion by stemflow, throughfall, rainfall were high $SO_{4}^{2-}$ ion at industrial areas, especially of $NO_{3}^{-}$ ion at urban areas. The concentration of basic ion all rain fall were high $Ca^{2+},\;Na^{+}$ ion at industrial areas, but there were high $Ca^{2+}$, $Na^{+}$ ion at urban areas. The concentration of $SO_{2}$ at survey areas were high $SO_{2}$ concentration at industrial and urban areas, but there was low at rural areas. There was correlation of negative ($r=-0.8007^{**}$ between pH and $SO_{2}$ concentration at survey areas. Soil acidity was also affected by stemflow and showed sigificantly low pH in industerial and urban areas.

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On the applications of AWS into the Four-Dimensional Data Assimllation Technique for 3 Dimensional Air Quality Model in Use of Atmospheric Environmental Assessment (환경영향평가용 대기질 모델을 위한 AWS자료의 4 차원 동화 기법에 관한 고찰)

  • Kim, Cheol-Hee
    • Journal of Environmental Impact Assessment
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    • v.11 no.2
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    • pp.109-116
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    • 2002
  • The diagnostic and prognostic methods for generating 3 dimensional wind field were comparatively analyzed and 4 dimensional data assimilation (FDDA) technique by incorporating Automatic Weather System (AWS) into the prognostic methods was discussed for the urban scale air quality model. The A WS covered the urban scale grid distance of 10.6 km and 4.3 km in South Korea and Kyong-in region, respectively. This is representing that AWS for FDDA could be fairly well accommodated in prognostic model with the meso${\gamma}$~ microa scale (~5 km), indicating that the 3 dimensional wind field by FDDA technique could be a useful interpretative tool in urban area for the atmospheric environmental impact assessment.

In vitro mutagenicity and genotoxicity study of PAHs and nitro-PAHs using the bacterial revertant (Ames) test and alkaline single cell gel electrophorosis (Comet) assay

  • Kim, Soung-Ho;Oh, Seung-Min;Chung, Kyu-Hyuck
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.284.1-284.1
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    • 2002
  • In previous studies, we demonstrated that ambient PM collected from urban site of Korea air could induce DNA damage, Various mutagens and carcinogens present in the urban air differ according to the source of the pollutants. Polycyclic aromatic hydrocarbons (PAHs) and their nitrated compound are produced in the combustion of fossil fuels as diesel emission exhausts. In recent, PAH and nitro-PAH have been identified in urban air particulate matter (PM). and some of them were found to be tumorigenic in experimental animals and humans. (omitted)

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Policy and Industry Trends in Urban Air Mobility (도심항공모빌리티(UAM) 관련 정책·산업 동향 및 이슈)

  • A. Hong;A.S. Park;M.S. Kim
    • Electronics and Telecommunications Trends
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    • v.38 no.4
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    • pp.36-46
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    • 2023
  • This paper presents concepts, policies, industry trends, and related issues in urban air mobility (UAM). UAM will contribute to transportation by mitigating traffic congestion and environmental problems in the future. Accordingly, governments of major countries are promoting UAM policies and demonstration projects as well as preparing laws and certification standards. In UAM, overseas startups lead airframe developments, and major companies from the aircraft, automotive, and information technology industries are also participating. In addition, startups and major companies are building the corresponding infrastructure. For the development of UAM, issues related to technology, regulation systems, and infrastructure still need to be resolved.

A Study on the Relationship between Land Cover Type and Urban Temperature - focused on Gimhae city - (토지피복유형 특성과 도시 온도의 관계 분석 - 김해시를 대상으로 -)

  • SONG, Bong-Geun;PARK, Kyung-Hun
    • Journal of the Korean Association of Geographic Information Studies
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    • v.22 no.2
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    • pp.65-81
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    • 2019
  • This study analyzed the relationship of land cover type, urban temperature in Gimhae city, Gyeongsangnam-do, South Korea. Date were used for land cover map, MODIS LST, and detailed temperature data on the Korean Peninsula based on RCP between 2000 and 2010. The correlation between urban area and surface temperature was 0.417, 0.512 for agricultural area and -0.607 for forest area. The correlation between surface temperature and air temperature was 0.301. The relationship with air temperature was analyzed as 0.275 for urban area, agriculture area 0.226, forest area 0.350. Urban and agricultural areas showed increased surface and air temperature as the area increased, while forest areas showed opposite improvements. In structural equation models, urban and agricultural areas had direct effects on the rise of surface temperature, whle forest areas had direct effects on the reduction of air temperature. In the future, it is necessary to use measured temperature data near the surface to understand the relationship between surface temperature and temperature according to the changes in spatial characteristics, which will prepare measures for urban heat island mitigation at the level of urban and environmental planning.

Characterization of Air Quality in Various Types of Indoor Environments in Urban Areas - Focusing on Homes, Offices, and Restaurants - (도시지역 실내환경 유형별 공기질 특성 평가 -가정, 사무실 및 식당을 중심으로-)

  • 백성옥;김윤신
    • Journal of Korean Society for Atmospheric Environment
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    • v.14 no.4
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    • pp.343-360
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    • 1998
  • In this study, comprehensive air quality monitoring was undertaken with a variety of objectives to collect data on the levels of various indoor and ambient air quality parameters in the urban areas of Seoul and Taegu. The sampling sites were comprised of six offices, six residences and six restaurants in each city. The ambient air adjacent to the indoor sites was also simultaneously sampled for the same constituents. The sampling was conducted in two phases: summer of 1994 and winter of 1994/95. A range of air quality parameters were measured simultaneously, which include RSP, CO, COB, NOB, a range of VOC, airborne microbials, temperature, and relative humidity. The indoor and ambient levels of the pollutants measured in this study varied widely between the three types of environments studied. Comparison of median values for the three groups revealed that restaurants had higher indoor levels of most pollutants than homes or offices. There was also a clear pattern of the indoor levels of target pollutants being higher than those outdoors, particularly in restaurants. Concentrations of CO and most of the VOC were found to be significantly higher in the commercial districts, indicating the influence of vehicle exhaust emissions. A very wide range of VOC levels was documented in this study. Although median indoorloutdoor ratios indicated a generally increasing level of VOC indoors when compared to those outdoors, no statistically significant differences were found between indoor and outdoor VOC levels in homes and offices, implying the importance of ambient air quality in determining the quality of indoor air for homes and offices in urban areas. In addition, there was a general pattern of increasing concentrations from summer to winter, and similarly from outdoor to indoor air for nearly all target compounds. The seasonal differences in median levels were very clearly seen for fuel combustion related pollutants such as RSP, CO and VOC, this being attributed to the effects of increased fuel consumption during the cold season and to meteorological factors.

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Air Temperature Differences in Areas with High-rise Buildings (초고층빌딩지역의 기온차)

  • Jin, Wen-Cheng;Lee, Kyoo-Seock
    • Journal of the Korean Institute of Landscape Architecture
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    • v.40 no.1
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    • pp.12-22
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    • 2012
  • In Seoul, skyscrapers are built in commercial zones known as residential-commercial complexes, which cause such environmental problems as urban heat islands(UHI) and air pollution. To investigate air temperature differences in areas near skyscrapers at Gangnam-gu, Seoul, South Korea, fixed air temperature observation and traverse observations were performed from March 16, 2008 to March 15, 2009. The annual mean air temperature at Tower Palace(TPL) was higher than that at Sookmyung Girls' High School(SMG) by $0.7^{\circ}C$, although the distance between the two observation positions is only 200m. The number of tropical nights at TPL was 13, while that at SMG was 5. The higher air temperature at TPL was due to a significantly lower sky view factor(SVF), which prevented long-wave radiation from emitting into the sky. The highest air temperature increases near TPL occurred on summer nights because of the high-electricity consumption value of $70.22Wh/m^2$ for the TPL block in August due to air conditioning for cooling. It is concluded that the warm air pocket centered on TPL.