• Title/Summary/Keyword: airborne measurement

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A Study on the Sanitary Condition of Kitchens in Food Court/Cafeterias - An Observation on Seasonal Variations (휴게음식점 주방의 환경위생상태에 관한 조사연구 - 계절별 변화를 중심으로 -)

  • Kim, Jong-Gyu;Park, Jeong-Yeong;Kim, Joong-Soon
    • Journal of Environmental Health Sciences
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    • v.38 no.2
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    • pp.118-127
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    • 2012
  • Objectives: This study was undertaken to assess the sanitary conditions in the kitchens of food court/cafeterias and determine seasonal variations. Methods: We measured environmental factors (air temperature, relative humidity, illumination intensity, noise level), and dropping airborne microbes (bacteria and fungi) in the kitchens of eight food court/cafeterias in four seasons (January, April, July, and October). Air temperature and relative humidity were measured with in/out thermo-hygrometers at 1.2-1.5 m above floor level. Illuminance measurement was performed through the multiple point method of Korean Standards (KS). Noise level was measured by the standard methods for the examination of environmental pollution (noise and vibration) of Korea. The estimation of dropping airborne bacteria and fungi was performed through use of Koch's method. Results: The highest kitchen air temperature was in July, and the lowest in January. The average temperature surpassed $21^{\circ}C$ throughout the seasons, suggesting a higher temperature than required for the safe handling of food. Humidity in all the kitchens was measured in the range of 50-60%. Half of the kitchens showed illumination intensities below 300 Lux in April. It was found that the sound pressure level of noise in almost all of the kitchens was higher than 85 dB (A). The highest levels of dropping airborne bacteria and fungi were noted in July. The numbers of airborne bacteria were higher than those of fungi. The levels of dropping airborne bacteria and fungi were affected by air temperature, relative humidity, season, and place. Conclusions: This study indicates that the kitchen environments were unqualified to supply safe food. The hygiene level of the kitchens should be improved.

MLS for Building Acoustics Measurement (건축음향을 위한 MLS 측정방법)

  • Borjabad, Roberto
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 1996.10a
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    • pp.386-393
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    • 1996
  • The paper describes how a Maximum Length Sequence(MLS) and correlation technique in the form of Hadamard transformation may be applied for the measurement of airborne sound reduction. It is shown that in most cases, the values obtained by the MLS technique will be equal to the expected values obtained by the classical method. However, due to the correlation process involved, the MLS method will be much less sensitive to disturbances from extraneous noise. The described method has been implemented in an RTA acoustic analyser.

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Estimation of SO2 emissions in large point sources at Dangjin City using airborne measurements (항공관측 결과를 활용한 당진시 대형사업장에서의 황산화물 배출량 평가)

  • Kim, Yong Pyo;Kim, Saewung;Kim, Jongho;Lee, Taehyoung
    • Particle and aerosol research
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    • v.16 no.4
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    • pp.107-117
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    • 2020
  • Based on the airborne measurement results over a coal fired power plant and steel work in Dangjin city, SO2 emission amounts of each site are estimated (top-down emission). Airborne measurements were carried out on May-June and October-November 2019. The estimated SO2 emission in 2019 for the power plant was 1502.1 kg/hr and that for the steel work was 2850.5 kg/hr, higher as much as a factor of 2.5 and 2.0, respectively, than the emission amounts provided by both facilities (bottom-up emission). The outcomes strongly illustrates that well designed airborne observations can serve a quantitative diagnostic tool for bottom-up emission estimates. Further research direction to improve the reliability of the top-down emission estimates is suggested.

Analysis of airborne sound insulation performance by the experiment using small size specimen (축소시편 실험을 통한 공기전달음 차단성능 분석)

  • Kim, Hang;Park, Hyeon Ku;Goo, Hee Mo;Kim, Sun-Woo
    • KIEAE Journal
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    • v.14 no.1
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    • pp.83-89
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    • 2014
  • The residents' demand for the comfortable life is promoting development of wall and window which has high sound insulation performance. To develop wall system, various aspects should be considered on the environment, material, construction and structure. Especially focusing on the acoustical view, the economical solution is one of the most critical point. Recently the interest on the partition wall is being increased, because it is useful for the Rahmen type apartment which is considered as an alternative to reduce floor impact sound. This study examines simplified measurement method of airborne sound insulation applied small size specimen, in order to save money to be used for the standard specimen then to promote the development process. The results showed that the simplified method could be effective for the wall system the sound insulation performance upto Rw 50 dB, and for the judgement of rank order of sound insulation performance of the similar wall type while developing.

Estimation of Maximum Volume in Landfill Site Using Airborne LiDAR Measurement (항공LiDAR 자료를 이용한 생활폐기물매립장의 가용한도 추정)

  • Byun, Sang-Chul;Choi, Myung-Kyu;Kim, Jin-Kwang
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.28 no.5
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    • pp.547-554
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    • 2010
  • This study intends to analyze how long the landfill site will be available by estimating maximum volume of landfill. Preestimated volume was calculated using digital maps and scheme drawings. The latest reclamation volume was measured using the state-of-the-art airborne LiDAR technology. Based on these data. landfill volume of now, carries in volume of past a few years and subsidence rate were calculated. As a result of study, the remaining capacity of this landfill site was estimated that it would be available till 2045.

Measurement of the Elemental Composition in Airborne Particulate Matter Using Instrumental Neutron Activation Analys

  • Chung, Yong-Sam;Lim, Jong-Myoung;Moon, Jong-Hwa;Kim, Sun-Ha;Cho, Hyun-Je;Kim, Young-Jin
    • Nuclear Engineering and Technology
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    • v.36 no.5
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    • pp.450-459
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    • 2004
  • For the evaluation of emission sources by air sampling, airborne particulate matter for fine (<2.5 ${\mu}m2$ EAD : $PM_{2.5}$) and coarse partical (2.5-10 ${\mu}m2$ EAD : $PM_{2.5-10}$ fractions were collected using a Gent stacked filter unit low volume sampler and two types of polycarbonate filters. Air samples were collected twice monthly at two regions in and around Daejeon city in the Republic of Korea from January to December 2002. Monthly mass concentration of $PM_{2.5}$ and $PM_{2.5-10}$ were measured and the concentrations of 10 marker elements (Al, Sc, Ti ; Na, Cl ; As, V. Sb, Br, Se) were determined by an instrumental neutron activation analysis. Analytical quality control was corried out using certified reference materials. Enrichment factors were also calculated from the monitoring data to classify the anthropogenic and crustal origins.