• 한국산업보건학회지
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• 제25권4호
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• pp.465-471
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• 2015

Objectives: An objective of this study is to apply a thermal image camera which shows various color according to temperature of indoor surface for estimating concentration of airborne fungi. Materials and Methods: While wall temperature were monitored by applying the thermal image camera, airborne bacteria as well as air temperature and relative humidity have been measured in lecture room and toilet of university for seven months. Results: Based on the results obtained from this study, the ranges of temperature and airborne fungi concentration were $20{\sim}24^{\circ}C$ and $20{\sim}400cfu/m^3 $ for red image, $17.5{\sim}20^{\circ}C$ and $35{\sim}150cfu/m^3$ for orange image, $15.5{\sim}17.5^{\circ}C$ and $25{\sim}650cfu/m^3$ for sky-blue image, and $13.5{\sim}15.5^{\circ}C$ and $50{\sim}200cfu/m^3$ for blue image, respectively. The color of indoor surface taken shot by thermal image camera showed consistent trend with temperature of indoor surface. There is, however, little correlation between color of indoor surface and airborne fungi concentration(p>0.05). Among environmental factors, relative humidity in indoor air showed a significant relationship with airborne fungi concentration(p<0.05). Conclusions: The more measurement data for proving statistically an association between color of indoor surface and airborne fungi concentration should be provided to easily estimate indoor level of airborne fungi.

• Journal of Preventive Medicine and Public Health
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• 제39권4호
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• pp.325-330
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• 2006

Objectives: The aims of this study were to examine the level of airborne fungi and environmental factors in Seoul metropolitan subway stations and to provide fundamental data to protect the health of subway workers and passengers. Methods: The field survey was performed from November in 2004 to February in 2005. A total 22 subway stations located at Seoul subway lines 1-4 were randomly selected. The measurement points were subway workers' activity areas (station office, bedroom, ticket office and driver's seat) and the passengers' activity areas (station precincts, inside train and platform). Air sampling for collecting airborne fungi was carried out using a one-stage cascade impactor. The PM and CO2 were measured using an electronic direct recorder and detecting tube, respectively. Results: In the activity areas of the subway workers and passengers, the mean concentrations of airborne fungi were relatively higher in the workers' bedroom and station precinct whereas the concentration of particulate matter, $PM_{10}\;and\;PM_{2.5}$, were relatively higher in the platform, inside the train and driver's seat than in the other activity areas. There was no significant difference in the concentration of airborne fungi between the underground and ground activity areas of the subway. The mean $PM_{10}\;and\;PM_{2.5}$ concentration in the platform located at underground was significantly higher than that of the ground (p<0.05). Conclusions: The levels of airborne fungi in the Seoul subway line 1-4 were not serious enough to cause respiratory disease in subway workers and passengers. This indicates that there is little correlation between airborne fungi and particulate matter.

• Safety and Health at Work
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• 제14권2호
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• pp.215-221
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• 2023

Background: There is little information about the airborne hazardous agents released during the heat treatment when manufacturing a welding material. This study aimed to evaluate the airborne hazardous agents generated at welding material manufacturing sites through area sampling. Methods: concentration of airborne particles was measured using a scanning mobility particle sizer and optical particle sizer. Total suspended particles (TSP) and respirable dust samples were collected on polyvinyl chloride filters and weighed to measure the mass concentrations. Volatile organic compounds and heavy metals were analyzed using a gas chromatography mass spectrometer and inductively coupled plasma mass spectrometer, respectively. Results: The average mass concentration of TSP was 683.1±677.4 ㎍/m³, with respirable dust accounting for 38.6% of the TSP. The average concentration of the airborne particles less than 10 ㎛ in diameter was 11.2-22.8×10⁴ particles/cm³, and the average number of the particles with a diameter of 10-100 nm was approximately 78-86% of the total measured particles (<10 ㎛). In the case of volatile organic compounds, the heat treatment process concentration was significantly higher (p < 0.05) during combustion than during cooling. The airborne heavy metal concentrations differed depending on the materials used for heat treatment. The content of heavy metals in the airborne particles was approximately 32.6%. Conclusions: Nanoparticle exposure increased as the number of particles in the air around the heat treatment process increases, and the ratio of heavy metals in dust generated after the heat treatment process is high, which may adversely affect workers' health.

• 한국대기환경학회지
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• 제13권3호
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• pp.207-214
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• 1997

We collected airborne complex mixtures in a industrial area of Yeochun, and examined whether these complex mixtures could affect gap junctional intercellular communication (GJIC) in a cultured WBF-344 rat liver epithelial cells (LEC). Since the reduction of GJIC plays an important role in chemical carcinogenesis, measurement of changes of GJIC is a meaningful method to screen carcinogenicity of these mixtures. High and low volume samples were dissolved in dimethyl sulfoxide (DMSO) and tested. Blank filter extractions were also examined for exclud-ing possible toxicity of filter itself, and TPA (12-O-tetradecanoylphorbol-13-acetate) and DMSO were used as positive and negative control, respectively. When the cells were exposed to samples at concentration below that required to maintain rather than 85% cell viability based on the result of neutral red uptake assay, maximal inhibition of GJIC was observed at 1hr after treatment with both high and low volume samples by scrape-loading dye transfer assay. In fluorescence recovery after photobleaching assay, recovery rates via gap junctions were 33%/min in high volume sample and 62%/min in low volume sample. In together, airborne samples collected in Yeochun inhibited GJIC in a cultured WBF-344 rat LEC. These results suggest airborne samples tested in this experiment may attribute to cause a certain type and degree of cancers in in vivo when exposured for some periods.

• 한국통신학회논문지
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• 제8권1호
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• pp.1-11
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• 1983

PCM方式에 의한 Telemetry system을 各部別로 設計 및 構成하여 搭載型航空遠隔測定裝置의 開發을 처음으로 追究하였다. 여기에 사용된 時分割多重化方式의 主裝置인 PCM Encoder의 機能은 最大許容人力이 64words/frame이며 bit rate는 140kbit/sec, sampling rate는 200 frames/sec, 그리고 resolution은 10bits/word이다. 그리고 送信裝置의 周波數帶域은 telemetry band인 2.2-2.3GHz(S-band)를 사용하였으며 變調方式은 PCM/FM으로 設計하였다. 이와 같은 telemetry system에 대한 硏究는 처음 試裝開發되는 모든 飛行　에 대하여 飛行試驗中에 일어나는 各種飛行資料를 獲得하기 위한 遠隔測定裝置에 대한 硏究로서 완벽한 性能과 機能을 確認하였다.

• 한국산업보건학회지
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• 제23권4호
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• pp.341-347
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• 2013

Objectives: The aim of this study is to investigate the differences in airborne TDI concentrations based on the filter collection method and liquid collection method and to compare airborne TDIs concentrations by sampling method change when using the filter collection method in the spray-painting process. Methods: For the sample measurement, the filter collection method(OSHA#42) and liquid collection method(NIOSH#5522) were used; for the sampling method, the full-period single sampling and full-period consecutive sampling methods were used. The samples were collected in spray-painting and drying process locations. Results: In all samples collected from the spray-painting and drying process locations through the filter collection and liquid collection methods, greater amounts of 2,6-TDI than 2,4-TDI were detected. When the TDI collection concentrations based on the sampling methods were compared, the concentrations of 2,4-TDI and 2,6-TDI collected by the consecutive sampling method were higher than the concentrations of 2,4-TDI and 2,6-TDI collected by the single sampling method for both the filter collection method and liquid collection method used in the spray-painting process. These differences were statistically significant. Conclusions: When TDI collection concentrations based on the sample measurement methods were compared, the concentration of 2,4-TDI and 2,6-TDI collected through the liquid collection method were higher than the concentrations of 2,4-TDI and 2,6-TDI collected by the filter collection method, and the differences were statistically significant. In the drying process, no difference was shown in the collection concentrations of 2,4-TDI and 2,6-TDI with the two measurement methods.

• 한국산업안전학회:학술대회논문집
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• 한국안전학회 1999년도 춘계 학술논문발표회 논문집
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• pp.271-276
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• 1999

미국을 비롯한 선진국들은 이미 휘발성 유기화합물(volatile organic compounds) 과 독성 중금속(toxic metals)을 비롯한 유해 대기오염물(hazardous air pollutants)에 대해 ATEOS (Airborne Toxic Element and Organic Species), TEAM(Total Exposure Assessment Measurement) 연구등의 대규모 연구를 통하여 인체에 미치는 영향이 가장 큰 물질군이 휘발성 유기화합물임을 밝혀낸 바 있다. (중략)

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2011년도 춘계학술대회 논문집
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• pp.593-594
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• 2011

• Nuclear Engineering and Technology
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• 제10권1호
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• pp.13-25
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• 1978

1970년 12월에서 1976년 12월 사이의 6년간 고리 원자력발전소 주변 환경에서 채취한 시료에 대하여 환경방사능을 측정조사하였다. 1976년에 채취한 공기미진에서 진알파 방사능과 1970년 12월에서 1976년 12월 사이에 채취한 시료인 토양, 물, 공기미진, 낙진, 솔잎, 빗물과 여런 식품시료에 페하여 전베타 방사능을 측정하였다. 시금치, 배추, 보리, 쌀, 뱀장어, 조기, 미역, 파해 및 우유 중에 함유된 스트론튬-90및 세시움-137 방사능은 방사화학적으로 분석하여 측정하였고 정수, 하천수, 바닷물 중의 트리튬도 전해법으로 농축하여 그 방사능을 측정하였다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2007년도 춘계학술대회논문집
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• pp.411-415
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• 2007

The reduction of airborne and structure-borne noise of a shipboard pump for a navel ship is very important because the noise levels of the pump must not exceed criteria such as MIL-STD. In this paper, several practical examples of reducing the noise levels are presented. The examples show that the inadequate rotor-balancing and shaft-alignment results in the increase of the structure-borne noise on all lower mounts. It is also found that the unequal loading on mounts can cause the dramatically increasing the noise levels on certain local positions. Since the piping system arrangement such as valve location, flexible joint, and elbow location affects on the noise measurement, care must be taken to minimize the unnecessary noise from the piping system.