• 제목/요약/키워드: School Dust

검색결과 539건 처리시간 0.028초

미세먼지 차단 기능성 의류 제품의 성능 평가에 관한 연구 (Performance Evaluation of Fine-Dust Blocking Effect of Functional Clothing)

  • 황석주;이창훈;권진경;김영실;최은진;김다진;김민;육세진
    • 한국입자에어로졸학회지
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    • 제18권4호
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    • pp.137-145
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    • 2022
  • As many studies on the harmfulness of fine dust have been reported, awareness of its seriousness is spreading. Recently, interest in indoor air quality as well as air pollution is increasing, and research on measures to block fine dust flowing into the room from the outside is being conducted. The clothing company is launching functional clothing to prevent fine dust attached to clothing from entering the room through outdoor activities. However, it is difficult to confirm whether there is actually fine-dust blocking performance, and there is no evaluation standard. In this study, the contamination rate caused by fine dust was quantitatively compared through image processing after contamination of the outer fabric for 4 types of commercially available functional clothing with fine-dust blocking effect. The difference in particle contamination according to the material of the outer fabric was analyzed by comparing the surface resistance, and it was found that the higher the surface resistance of the outer fabric material, the more fine dust was attached. The analysis method of this study is expected to be able to quantitatively compare and evaluate the fine-dust blocking performance of functional clothing.

PROPERTIES OF DUST IN VARIOUS ENVIRONMENTS OF NEARBY GALAXIES

  • Kaneda, Hidehiro;Kokusho, Takuma;Yamada, Rika;Ishihara, Daisuke;Oyabu, Shinki;Kondo, Toru;Yamagishi, Mitsuyoshi;Yasuda, Akiko;Onaka, Takashi;Suzuki, Toyoaki
    • 천문학논총
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    • 제32권1호
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    • pp.135-139
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    • 2017
  • We have performed systematic studies of the properties of dust in various environments of nearby galaxies with AKARI. The unique capabilities of AKARI, such as near-infrared (near-IR) spectroscopy combined with all-sky coverage in the mid- and far-IR, enable us to study processing of dust, particularly carbonaceous grains includings polycyclic aromatic hydrocarbons (PAHs), for unbiased samples of nearby galaxies. In this paper, we first review our recent results on individual galaxies, highlighting the uniqueness of AKARI data for studies of nearby galaxies. Then we present results of our systematic studies on nearby starburst and early-type galaxies. From the former study based on the near-IR spectroscopy and mid-IR all-sky survey data, we find that the properties of PAHs change systematically from IR galaxies to ultraluminous IR galaxies, depending on the IR luminosity of a galaxy or galaxy population. From the latter study based on the mid- and far-IR all-sky survey data, we find that there is a global correlation between the amounts of dust and old stars in early-type galaxies, giving an observational constraint on the origin of the dust.

House Dust Mite Allergens in Domestic Homes in Cheonan, Korea

  • Nam, Hae-Seon;Siebers, Robert;Lee, Sun-Hwa;Park, Joon-Soo;Kim, Yong-Bae;Choi, Young-Jin;Lee, Sang-Han;Crane, Julian
    • Parasites, Hosts and Diseases
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    • 제46권3호
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    • pp.187-189
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    • 2008
  • House dust mites produce inhalant allergens of importance to allergic patients, We measured the major group 1 allergens, Der p 1 and Der f 1, from the house dust mites Dermatophagoides pteronyssinus and Dermatophagoides farina, respectively in 100 randomly selected domestic homes from Cheonan, Korea, Dust samples were collected by vacuuming from the living room floor and 1 mattress in each home, Der p 1 and Der f 1 were measured by double mono-clonal ELISA. Der p 1 levels were very low, with geometric mean levels for floors and mattresses being $0.11\;{\mu}g/g$ (range: 0.01-4.05) and $0.14\;{\mu}g/g$ (range: 0.01-30.0), respectively. Corresponding levels of Der f 1 were higher, $7.46\;{\mu}g/g$ (range: 0.01-262.9) and $10.2\;{\mu}g/g$ (range: 0.01-230.9) for floors and mattresses, respectively. D. farinae appears to be the dominant house dust mite in Cheonan.

다파장 라만 라이다 시스템을 이용한 고도별 황사의 단산란 알베도 산출 (Retrieval of Vertical Single-scattering albedo of Asian dust using Multi-wavelength Raman Lidar System)

  • 노영민;이철규;김관철;신성균;신동호;최성철
    • 대한원격탐사학회지
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    • 제29권4호
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    • pp.415-421
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    • 2013
  • 본 연구에서는 다파장 라만 라이다 시스템을 이용하여 대기 중의 비구형 순수 황사입자와 구형 오염 입자가 혼합된 황사 입자의 단산란 알베도를 산출할 수 있는 방법론을 제시하고, 실제 대기 관측 사례 분석 자료로부터 정확도를 검증하고자 하였다. 편광소멸도는 황사와 비황사와의 혼합정도에 반비례함을 응용하여 편광소멸도 값으로부터 황사비를 산출하고 이를 이용하여 황사와 비황사로 황사층을 구분하였다. 산출된 비황사의 두 파장(355, 532 nm)의 소산계수와 세 파장(355, 532, 1064 nm)의 후방산란계수를 이용하여 역행렬 분석을 수행하여 비황사의 고도별 단산란알베도를 도출하였다. 황사와 비황사의 가중치를 소산계수값으로부터 산출하고 각 가중치를 황사와 비황사에 적용하여 황사 층 전체의 고도별 단산란알베도를 산출하였다. 단, 황사의 단산란알베도는 순수황사로 가정하여 발원지에서 측정된 순수황사가 나타내는 0.96의 값을 적용하였다. 본 연구로부터 개발된 분석방법은 기존의 원격탐사 기술의 한계점을 극복하여 황사의 이동시 타 오염입자와의 혼합에 따른 광학적 특성의 변화에 대한 정밀한 자료를 제공할 수 있을 것으로 기대된다.

SMALL-SCALE STRUCTURE OF THE ZODIACAL DUST CLOUD OBSERVED IN FAR-INFRARED WITH AKARI

  • Ootsubo, Takafumi;Doi, Yasuo;Takita, Satoshi;Matsuura, Shuji;Kawada, Mitsunobu;Nakagawa, Takao;Arimatsu, Ko;Tanaka, Masahiro;Kondo, Toru;Ishihara, Daisuke;Usui, Fumihiko;Hattori, Makoto
    • 천문학논총
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    • 제32권1호
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    • pp.63-65
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    • 2017
  • The zodiacal light emission is the thermal emission from the interplanetary dust and the dominant diffuse radiation in the mid- to far-infrared wavelength region. Even in the far-infrared, the contribution of the zodiacal emission is not negligible at the region near the ecliptic plane. The AKARI far-infrared all-sky survey covered 97% of the whole sky in four photometric bands with band central wavelengths of 65, 90, 140, and $160{\mu}m$. AKARI detected the small-scale structure of the zodiacal dust cloud, such as the asteroidal dust bands and the circumsolar ring, in far-infrared wavelength region. Although the most part of the zodiacal light structure in the AKARI far-infrared all-sky image can be well reproduced with the DIRBE zodiacal light model, there are discrepancies in the small-scale structures. In particular, the intensity and the ecliptic latitude of the peak position of the asteroidal dust bands cannot be reproduced precisely with the DIRBE models. The AKARI observational data during more than one year has advantages over the 10-month DIRBE data in modeling the full-sky zodiacal dust cloud. The resulting small-scale zodiacal light structure template has been used to subtract the zodiacal light from the AKARI all-sky maps.

Risk Assessment of Exposure to Silica Dust in Building Demolition Sites

  • Normohammadi, Mohammad;Kakooei, Hossein;Omidi, Leila;Yari, Saeed;Alimi, Rasul
    • Safety and Health at Work
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    • 제7권3호
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    • pp.251-255
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    • 2016
  • Background: Building demolition can lead to emission of dust into the environment. Exposure to silica dust may be considered as an important hazard in these sites. The objectives of this research were to determine the amount of workers' exposure to crystalline silica dust and assess the relative risk of silicosis and the excess lifetime risk of mortality from lung cancer in demolition workers. Methods: Four sites in the Tehran megacity region were selected. Silica dust was collected using the National Institute for Occupational Safety and Health method 7601 and determined spectrophotometrically. The Mannetje et al and Rice et al models were chosen to examine the rate of silicosis-related mortality and the excess lifetime risk of mortality from lung cancer, respectively. Results: The amount of demolition workers' exposure was in the range of $0.085-0.185mg/m^3$. The range of relative risk of silicosis related mortality was increased from 1 in the workers with the lowest exposure level to 22.64/1,000 in the employees with high exposure level. The range of the excess lifetime risk of mortality from lung cancer was in the range of 32-60/1,000 exposed workers. Conclusion: Geometric and arithmetic mean of exposure was higher than threshold limit value for silica dust in all demolition sites. The risk of silicosis mortality for many demolition workers was higher than 1/1,000 (unacceptable level of risk). Estimating the lifetime lung cancer mortality showed a higher risk of mortality from lung cancer in building demolition workers.

Correlation of Air Pollutants and Thermal Environment Factors in a Confined Pig House in Winter

  • Choi, Hong L.;Kim, Ki Y.;Kim, Hyunook
    • Asian-Australasian Journal of Animal Sciences
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    • 제18권4호
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    • pp.574-579
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    • 2005
  • Optimal management of indoor air quality in a confined pig house, especially in winter, is indispensable for preventing infectious respiratory disease to workers and animals. This study was performed to elucidate the correlation of aerial contaminants and climate factors in a confinement. It was observed that indoor air contaminants ion in the confinement was the highest at 2:00-5:00 pm in a day, followed by 8:00-11:00 pm and 8:00-11:00 am. This was attributed to the increase of pig activities in the afternoon. The concentration of total dust and total airborne bacteria was found to have a significant correlation with temperature and relative humidity (p<0.05). Correlation of total dust and total airborne bacteria, total dust and ammonia, and total dust and odor were shown statistically significant at 95% confidence level. In conclusion, temperature and total dust concentration correlated significantly with all the parameters except for hydrogen sulfide ($H_2S$). This could be explained by the fact the dryness of pig feces by increase of interior temperature and resuspension of feed deposited on the floor by the pig activity, resulted in high generation of dust which adsorbed and carried the airborne bacteria and odor compounds in a confined pig house. It was proved that the adsorptive capacity of dust with ammonia ($NH_3$) was higher than that with hydrogen sulfide ($H_2S$).

폐플라스틱/제강 Dust 성형제의 용출안전성에 대한 연구 (Elution Safety of Recycled Plastic/EAF Dust Composites by Using Leaching Test)

  • 강영구;송종혁
    • 한국안전학회지
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    • 제18권4호
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    • pp.85-91
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    • 2003
  • In this study, We have investigated leaching characteristics of heavy metals for recycled plastic composites containing EAF(Electric Arc Furnace) dust & EAF slag. EAF dust & EAF slag used that is generated in the 3 steel-making compaines in domestic. The physical and chemical properties of EAF dust & slag was examined by measuring specific surface area. porosity, oil absorption test and chemical wetting analysis etc. Results of total analysis indicated that EAF dust, slag contained significant amount of hazardous metals such as Cu, Pb, Cd and Cr. But, In the leaching test of the recycled plastic composites containing EAF dust, slag by Korean Standard Leaching Procedure, composites shows much lower leaching concentration of heavy metals. It was concluded that the recycled plastic composites containing EAF dust, slag showed good physical and chemical characteristics. This means that the EAF dust, slag can be effectively used as a functional filler.

Detection of Asian Dust Air-mass based on Short Wavelength Observation of SeaWiFS

  • Fukushima, H.;Hagihara, Y.;Hoshikuma, Y.;Ohta, S.;Uno, I.
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2003년도 Proceedings of ACRS 2003 ISRS
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    • pp.1203-1205
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    • 2003
  • To detect dust-loaded air-mass over land and ocean, we propose an index, which is essentially the difference in Rayleigh-corrected reflectance between 412 and 443 nm bands of SeaWiFS. Radiative transfer simulations are conducted to show that the index is linearly related to the optical thickness of modeled dust-contaminated aerosol while showing insensitivity against non-absorbing model aerosols. Asian SeaWiFS data set of 2001 spring is used to produce daily composite imagery of the index, which compares well with TOMS Aerosol Index and with predicted aerosol optical thickness predicted by CFORS chemical weather forecast.

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황사농도 단기예측모델의 PM10 농도와 실측 PM10 농도의 비교 - 2006년 4월 7~9일 황사 현상에 대해 - (Comparison of ADAM's (Asian Dust Aerosol Model) Results with Observed PM10 Data)

  • 조창범;전영신;구본양;박순웅;이상삼;정연양
    • 대기
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    • 제17권1호
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    • pp.87-99
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    • 2007
  • Simulation results of Asian Dust Aerosol Model (ADAM) for the period of April 7-9, 2006 were analyzed, comparing with observed PM10 data. ADAM simulated around ten times lower than on-site PM10 concentration in the source regions: Zhurihe, Tongliao, Yushe, Dalian and Huimin. As the result of this low concentration, transported amounts of Asian Dust were under-estimated as well. In order to quantify a forecasting accuracy, Bias and RMSE were calculated. Even though remarkably negative Biases and high RMSEs were observed, ADAM simulation had followed well up the time of dust outbreak and a transported path. However, the emission process to generate dust from source regions requires a great enhancement. The PM10 concentration at the surface reached up to $2,300{\mu}gm^{-3}$ at Baeknyoungdo and Seoul (Mt. Gwanak), up to $1,750{\mu}gm^{-3}$ at KGAWO about 18:00 LST in April 8, respectively; however, ADAM did not simulate the same result on its second peak. It is considered that traveling Asian dust might have been lagged over the Korean peninsula by the blocking of surface high pressure. Moreover, the current RDAPS's 30 km grid resolution (which ADAM adopts as the meteorological input data) might not adequately represent small-scale atmospheric motions below planetary boundary layer.