• 한국소음진동공학회논문집
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• 제24권1호
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• pp.35-44
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• 2014

Sound pressure levels in the receiving room while testing airborne sound insulation performance are varied by the measuring points. This may increase the measurement error, then decrease the measurement reliability. With this reason the research has carried out on the method to reduce deviations of sound pressure level in the ISO type rectangular laboratory focusing on the measurement of airborne sound insulation performance. Tests were made to see the effect of sound absorption in the receiving room, loudspeaker locations, microphones locations and flanking transmission path. Consequently, it was resulted that sound absorption in the receiving room and the loudspeaker location have influence on the sound level deviations especially in the low frequency. The microphone location was very important to get measurement reliability. The effective measuring point, which the sound level difference with average sound pressure level is within 2 dB, could yield most reliable average sound pressure level. Therefore it is necessary to find the effective measuring points in the receiving room. Flanking transmission path should be sealed using sound absorber or magnet etc. to prevent from lowering the sound insulation performance.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.249-250
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• 2023

The objective of this study is to evaluate the airborne sound insulation performance between housing units and community facilities during the construction phase. Community facilities adjacent to housing units can lead to noise problems, hence it is necessary to minimize noise transmission during the design phase. However, flanking noise transmitted through gaps of structures, windows, pipes, and other openings may result in substandard sound insulation performance falling below the design standards. Therefore, It is crucial to measure airborne sound insulation in the field during the construction phase. The measurement was conducted using the survey method for the field measurement of the airborne sound insulation in accordance with KS F ISO 10052:2021. Although the noise standards caused by community facilities in apartment complexes are not specified in current laws and regulations, desired noise level was set based on international guidelines for indoor noise. First, the level of noise generated in community facilities was estimated, and then the sound insulation performance was evaluated to determine whether the desired noise level was achieved.

• 한국산업보건학회지
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• 제16권2호
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• pp.101-109
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• 2006

The objective of this study is to provide fundamental data for pertinent management of indoor air quality through investigating the size-based characteristics of bioaerosol distributed in the general hospital. Measurement sites are main lobby, ICU, ward and laboratory and total five times were sampled with six-stage cascade impactor. Based on the result of this study, concentrations of airborne bacteria and fungi were the highest in main lobby as followed by an order of ward, ICU and laboratory. Concentrations of airborne bacteria was generally higher than those of airborne fungi and the ratio of indoor and outdoor concentration of both exceeded 1.0 in all the measurement sites of the general hospital. The predominant genera of airborne bacteria identified in the general hospital were Staphylococcus spp.(50%), Micrococcus spp.(15-20%), Corynebacterium spp.(5-20%), and Bacillus spp.(5-15%). On the other hand, the predominant genera of airborne fungi identified in the general hospital were Cladosporium spp.(30%), Penicillium spp.(20-25%), Aspergillus spp.(15-20%), and Alternaria spp.(10-20%). In regard to size distribution of bioaerosol, the detection rate was generally highest on 5 stage($1.1-2.1{\mu}m$) for airborne bacteria and on 1 stage(>$7.0{\mu}m$) for airborne fungi. Cleanliness of facilities in the general hospital and condition of HVAC system should be monitored regularly to prevent indoor air contamination by airborne microorganisms.

• 환경위생공학
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• 제14권3호
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• pp.139-149
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• 1999

This study was performed to investigate components of organic solvents and present statues of environmental measurements with official records of working environmental measurements of 4,181 workplaces in 3,280 workshops used airborne organic solvents. 1. The mean working hour of 4,181 workplace producing airborne organic solvents in 3,280 workshops was 437±28.7min, but the mean sampling time for measurement of airborne organic solvents was identified to be 254±28.8min. In 73.0% of 4,181 samples the sampling frequencys were Full-period, single sample measurement. 2. The total 54 components of organic solvents were measured in total airborne samples of 4,181 workplace in 3,280 workshops in both of first and second half-year. These were divided into 38 components, Group 1 substances (5 components), Group 2 substances (31 components) and Group 3 substances (2 components), regulated by the Industrial Safety and Health Law, and other 16 components without legal duty of working environment measurement. The most common component in each half-year was Toluene (84.8%, 88.2%), which was followed by Xylene (464.4%, 51.7%), Methyl ethyl ketone (31.1%, 34.4%), n-Hexane (22.7%, 27.8%) and Benzene (20.4%, 21.5%) in frequency. Of legal duty free components, Ethyl benzen, Trimethyl benzene and Pentane were frequently detected. In conclusion, these results show that the present legal classification system of organic solvents needs to revise. Also these results suggest that it must be necessary to analyze the component of airborne organic solvents mixture and to evaluate their effects on workers' health for the effective management of working environment in workshops treating with organic solvents.

• Asian Journal of Atmospheric Environment
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• 제7권2호
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• pp.105-113
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• 2013

We constructed and tested an airborne peroxyacetyl nitrate (PAN) monitoring system based on luminol chemiluminescence detection with fast gas chromatography. This system allowed for simultaneous measurement of PAN and nitrogen dioxide ($NO_2$) with a time resolution of <2 min. Actual sample masses within the fixed volume sample loop at various altitudes and temperatures were adjusted to standard atmosphere, using measured pressures and temperatures. The airborne PAN measurement system was evaluated during two field studies above the southern Korean Peninsula in August and October 2009. The detection limit based on the ISO approach was 0.035 ppbv PAN, well below the observed concentrations of 0.185-1.49 ppbv during these studies. Under these conditions, the PAN mixing ratios were positively correlated with $O_x$ ($O_x=O_3+NO_2$), with slopes varying between 0.014 and 0.033 and intercepts between 22.6 and 55.1 ppbv $O_x$. The intercepts corresponded roughly to background $O_x$ mixing ratios in central Europe; however, the slopes were above the range of slopes reported in other studies. We also enhanced the durability, safety, and ease of maintenance of the PAN monitoring system by redesigning the structure of the conventional luminol cell.

• 한국소음진동공학회논문집
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• 제13권8호
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• pp.637-644
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• 2003

Airborne noise is one of the considerable environmental factors for navy ship personnel who should accomplish their tasks in restricted ship spaces against adverse health effect of noise. However, it is difficult to find studies on actual condition of airborne noise for navy ships. In this study, we measured airborne noise levels at 379 compartments of 33 Korean navy ships. Using the measured data, we presented mean values and their standard deviations of measured noise levels with factors of ship type, compartment category, and operation mode. Additionally, we evaluated the mean value and cumulative probability of airborne noise levels of compartments with those of the US navy ships. These results can be rationally used in making the proper airborne noise criteria of the navy ship for the future.

• 한국농공학회논문집
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• 제61권5호
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• pp.79-87
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• 2019

With desires for safe food, there is growing concern that pesticide spray drift will expose people, plants, and the environment to pesticide residue and potential negative effects thereof. For highly efficient, safe spray application, technologies for measuring the spray drift should be developed and improved with some urgency. This study investigated the applicability of two optical particle counters (OPCs), which are mostly used to measure airborne particle mass concentration, for measurement of airborne pesticide spray drift. Experiments were conducted in a controlled laboratory and an ash tree orchard to evaluate the handiness and accuracy of two OPCs, OPC 1 and OPC 2. The experimental results indicated that the OPC 1 was better applicable to the measurement of spray drift in the field while the use of the OPC 2 was limited due to its narrow range of measurable droplet sizes. The readings of the OPC 1 produced highly accurate results ($R^2=0.9637$) compared to the actual spray drift. For better application of OPCs, this study suggests the OPCs should be positioned properly to inhale spray droplets of the appropriate size and concentration.

• Journal of Microbiology and Biotechnology
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• 제18권1호
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• pp.176-182
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• 2008

In the present study, a control methodology utilizing airborne silver nanoparticles is suggested and tested with respect to its potential to control Gram-positive Staphylococcus epidermidis and Bacillus subtilis, and Gram-negative Escherichia coli bacteria bioaerosols deposited on filters. As it is known that the Gram-negative bacteria are sensitive to airflow exposure, the main focus of this study for testing the airborne silver nanoparticles effect was the Gram-positive Staphylococcus epidermidis and Bacillus subtilis bacteria bioaerosols whereas Escherichia coli bioaerosols were utilized for comparison. Airborne bacteria and airborne silver nanoparticles were quantitatively generated in an experimental system. Bioaerosols deposited on the filter were exposed to airborne silver nanoparticles. The physical and biological properties of the airborne bacteria and airborne silver nanoparticles were measured via aerosol measurement devices. From the experimental results, it was demonstrated that this method utilizing airborne silver nanoparticles offers potential as a bioaerosol control methodology.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.313-314
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• 2021

An old building over 30 years old continue to increase. Therefore, there will be more dismantling of old buildings in the future. Safety management of dismantling works is being strengthened. However, no consideration has been given to the effects of dismantling workers and their residents due to environmental hazards arising from the demolition process. Only spray and dust prevention measures are subject to inspection to minimize dust generation considering civil complaints around the site of dismantling work. In this paper, residential buildings, which account for the largest proportion of old buildings, were collected and identify total airborne bacteria and floating fungi among environmental hazards caused by non-structural dismantling work. Measurement results showed that workers during dismantling work are working in places with 4.8 times more total airborne bacteria than indoor air quality maintenance standards. Related research is needed for the health of dismantling workers.

• 한국구조물진단유지관리공학회 논문집
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• 제27권6호
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• pp.13-21
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• 2023

본 연구에서는 인천항만 시설물의 대기 중 비래염분량을 조사하였다. 2021.9 ~ 2023.8월, 총 2년 동안 북항, 남항, 신항에 총 15개의 염분포집기를 설치하여 대기 중 비래염분량을 측정하고, 항만시설물과 측정환경에 따른 비래염분량의 분포 특징과, 해안거리에 따른 비래염분량의 감소 특성을 분석하였다. 그 결과, 북항, 남항, 신항의 월별 비래염분량 분포는 0.4 ~ 3.3 mdd로 유사하게 나타났으며, 해안선의 방향을 고려한 계절풍의 영향으로 북항과 남항은 겨울에, 신항은 여름에 비래염분량이 높게 나타났다. 측정환경에 따른 비래염분량의 특징으로는 동일 지역에서 내해보다 내륙에 위치하여 바다에서 부는 바람이 내해를 통과하여 지나가는 위치에 있는 지점에서 비래염분량이 높게 나타났다. 또한 동일지역에서 해안거리가 동일한 두 지점일지라도 지면으로부터 높이에 따라서 비래염분량에 차이가 있었다. 한편 간만대의 경우, 월별 비래염분량은 상부보다는 하부에서 현저히 높게 나타났으며, 예외적으로 상부의 비래염분량이 하부만큼 높은 기간은 최고조위와 조위차가 높은 특징이 있었다. 해안으로부터 거리에 따른 항별 비래염분량의 감소율식을 도출하였으며, 그 결과, 해안으로부터 멀어질수록 비래염분량의 감소율은 신항이 가장 크고, 남항이 가장 작게 나타났다.