• 한국산업보건학회지
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• 제15권1호
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• pp.1-7
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• 2005

Although the Fourier Transform Infra-Red spectrophotometric Direct on Filter(FTIR-DOF) method is a useful analytical technique for quantifying quartz content in respirable dust samples, a number of analytical problems must be taken into consideration such as, to name only a few, inhomogeneous deposition of particles, level of environmental humidity, uneven surface of the filter, and interfering minerals in the sample. This study was designed to select the most suitable wavelength and proper filter material for the method, and to investigate effects of humidity and inhomogeneous deposition of particles on the filter. Samples of respirable dust, created in a dust chamber containing standard material of quartz, were collected using a cyclone equipped with a 25mm filter as a collection medium. The results were as follows; 1. Among seven (7) commercially available filters tested for the FTIR-DOF method, the DM 800 filter showed the best analytical performance having the lowest background absorbance bands and no overlapping peaks at 799, 779, and $695cm^{-1}$. 2. The variations of absorbance due to humidity ranged from 1.0% to 3.3% for $799cm^{-1}$, 1.0% to 3.3% for $779cm^{-1}$, and 8.9%~20.9% for $695cm^{-1}$ peaks, respectively. The $699cm^{-1}$ peak was proved to be most vulnerble to environmental humidity for quantitative analysis of quartz. 3. As for effects of inhomogeneous deposition of samples, the highest variation of absorbance of 10.9% ($13.5{\mu}g$) was observed when using the 695cm-1. The variations of absorbance from the other two peaks, 799 and $779cm^{-1}$, ranged from 1.2 to 3.2%, and 1.4 to 4.1%, respectively. Therefore, the $799cm^{-1}$ peak was considered to be most reliable for quantitative analysis of quartz. The results of this study suggest that, for quantitative analysis of quartz in the respirable dust samples, use of the $799cm^{-1}$ peak can minimize the influence of environmental humidity and inhomogeneous deposition of particles on the filter. The FTIR-DOF method, if adopted for routine analysis of quartz in the respirable dust samples, could save sample preparation time and efforts substantially and also could increase analytical throughputs. Since use of the $799cm^{-1}$ peak is prone to be affected by interferences in the sample, further research on minimizing the effects is needed.

• International Journal of Safety
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• 제1권1호
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• pp.47-51
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• 2002

This study was performed by measuring the minimum ignition temperature of polyurethane form recovered from the recycling process of the end-of-life home appliances. The critical ignition temperature of polyurethane form was lower as the size of the sample vessel was increased, and that of polyurethane form using cyclopentane as the forming agent was relatively lower than the polyurethane form using CFC and the combustion of cyclopentane-polyurethane form occurred fiercely. It is considered that the recycling process of end-of-life home appliances using cyclopentane-polyurethane form as the insulator would require a special fire and dust explosion prevention measures since there exists a high potential hazard of fire and dust explosion during crushing and storage processes.

• 분석과학
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• 제26권2호
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• pp.113-119
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• 2013

본 연구에서는 전기전자제품에 브롬화난연제로 널리 사용되고 있는 폴리브롬화디페닐에테르가 우리의 생활에서 어떻게 배출되는지 파악하고자 가정에서 발생되는 먼지 시료를 2011년 1월부터 12월까지 채취 분석하여 이성체 함량특성을 조사하였다. 아파트와 실험실에서 채취한 실내 먼지 중 총 22종의 PBDEs (47, 49, 66, 71, 77, 85, 99, 100, 119, 126, 138, 153, 154, 156, 183, 184, 191, 196, 197, 206, 207, 209)를 분석하여 정량한 결과, 아파트 실내 먼지에서 검출된 PBDEs 농도는 35.22~575.88 ng/g으로 나타났으며, 실험실에서 겨울에 채취된 먼지 중에서는 PBDEs가 524.44 ng/g 검출되었다. 분석시료 중 1ng/g 이상 검출된 이성체는 BDE-47, 153, 183, 196, 197, 206, 207, 209 등 8종으로 조사되었으며, 모든 시료에서는 BDE-206, 207, 209 3종의 이성체가 검출되었다.

• Korean Chemical Engineering Research
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• 제59권3호
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• pp.359-365
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• 2021

본 연구에서는 분진의 착화 특성 및 정전기 위험성 평가법을 실험적으로 조사하였다. 착화에너지 시험은 PE(HD), PE(LD), PMMA 분진에 대해 MIKE-3장치를 사용하여 실시하였다. PE (HD)의 경우 약 8 ms의 일정 시간 경과 후에 분진운의 착화 화염이 형성되고, 착화원 중심부에서는 화염 핵이 관찰되지 않았다. 분진의 분산 횟수가 증가함에 따라 정전압이 증가하고 분진 농도에 따른 정전압 발생 증가율은 PMMA, PE(LD), PE (HD) 순으로 가장 높았다. PE(HD) 분진의 분산 조건이 정전압에 미치는 영향을 조사하였으며, 분산 횟수가 많아질수록 정전압이 증가하였고 동일한 분산 횟수에서는 분진 농도가 높아질수록 정전압이 증가하였다. 정전기 착화에 의한 화재폭발사고 예방을 위한 안전 정전압은 PE(HD), PE(LD)-1, PE(LD)-2, PMMA에 있어서 각각 2.58, 44.72, 25.82, 8.16 kV로 추정되었다. 정전압 측정자료를 사용하여 정전기 착화 위험성을 효율적으로 조사하여 최소착화에너지를 추정하는 방법을 제안하였다.

• 한국터널지하공간학회 논문집
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• 제19권4호
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• pp.589-609
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• 2017

석탄광산 분진을 환기로 제어하기 위해 현재 국내에서 가행되는 5개 광산의 석탄 분진 시료를 채취하여 석탄 분진의 특성인 밀도와 원소분석, 입도 분석을 시행하였다. 이것은 국내에서 생산되는 모든 무연탄에서 파생되는 석탄 분진의 특성을 이해함으로써 보다 쾌적한 작업환경을 제공하는 연구의 기초가 될 것이다. 입도분석(PSA)결과, 본 연구에 사용된 석탄 분진 시료입자의 크기는 $0.007{\sim}88.614{\mu}m$ 범위에 분포하였으며 이중 진폐증을 유발시킬 수 있는 $3.5{\mu}m$ 이하의 입자가 광산 내 상당부분 존재하는 것으로 확인되었다. 5개광업소에서 채취한 석탄광 분진의 풍속에 의한 유동을 알아보기 위해 풍동을 제작하여 풍속에 대한 석탄광 분진의 낙진을 측정하였으며, 낙진된 석탄 분진의 입도분석을 시행하였다. 또한, 실제 미세먼지가 다량으로 발생하는 채준 작업장에서 공기 중에 부유하는 미세먼지를 앤더슨 멀티스테이지 샘플러(Anderson multi-stage sampler)를 이용하여 석탄광 분진을 작업장에서 환기되는 풍속에 따라 측정하였으며 $3.5{\mu}m$ 이하의 석탄 분진을 제어하는 풍속을 실험을 통하여 밝혀냈다. 주선풍기의 과설계를 방지하기 위해 A광업소의 자연환기력을 계산하였다.

• 한국산업보건학회지
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• 제10권1호
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• pp.104-114
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• 2000

This study was carried out to estimate current status of dust concentrations in the factories producing non-metallic products in Korea. Data were gathered from the environmental monitoring reports by 40 workplace environmental monitoring institutes and the questionnaire designed for the study by the authors. A total of 1838 dust samples from 368 plants were obtained from the reports and were analyzed with no data modifications. But data on asbestos, rock wool, and welding fumes were excluded in this evaluation. The factories were classified into eight groups according to the standard industrial classification scheme in Korea. The results of this study were as follows; 1. The factories included were glass, non-refractory ceramic, refractory ceramic ware, structural non-refractory clay and ceramic, cement and lime, articles of concretes, and stone. Mean(geometric mean) concentrations of total dust samples ranged from $1.75(0.84)mg/m^3$ to $5.87(2.84)mg/m^3$. Statistically significantly higher dust concentrations were found in the cement and lime industries compared with other industries. 2. The non-compliance rates were 15.2% in glass and 20.6% in other non-metallic mineral products industries. Although all institutions surveyed utilized the identical sampling and classification scheme for dusts as specified in the current occupational exposure limits, wide discrepancies were found in collecting samples and classifying dusts. Further problems were discovered in classifying dusts. A dust sample collected could be classified into any of the three groups regardless of silica content. The results of this study showed that dust concentrations in the non-metallic products industries varied widely. Also discovered was classification errors of dust types among workplace monitoring institutes. These errors could adversely affect the results of exposure assessments and the true nature of dust hazards. Further, no institutions performed respirable dust sampling and analysis of crystalline silica. In order to correct these malpractices, current standards of occupational exposure limits should be revised and tight supervision by the Ministry of Labour be suggested.

• 분석과학
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• 제25권6호
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• pp.476-482
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• 2012

황사입자들은 수 나노미터에서 수 마이크론 사이의 크기를 가지는 것으로 알려져 있다. 황사가 환경 및 인체 건강에 미치는 영향은 황사 입자의 크기에 의존한다. 입자가 작을수록 멀리까지 이동하며, 인체의 호흡기관 깊숙이 침투한다. 침강장-흐름 분획법(sedimentation field-flow fractionation, SdFFF)은 채널 내 포물선형태의 흐름(parabolic flow profile)과 외부에서 가해지는 원심력의 상호작용을 이용하여 나노 및 마이크론 크기의 입자들의 분리를 제공한다. 본 연구에서는 황사입자의 크기별 분리와 특성분석을 위한 steric 모드 침강장-흐름 분획법(Sd/StFFF)의 응용 가능성을 테스트하였다. 이를 위하여 다양한 Sd/StFFF 파라미터들을(유속, stop-flow time, 원심력의 세기, 등) 최적화 하였다. Sd/StFFF 보정곡선의 $R^2$값은 0.9983으로 높은 직선성을 보였으며, 실험결과는 Sd/StFFF가 마이크론 입자의 크기별 분리에 우수함을 보여주었다. 광학현미경(optical microscopy, OM)을 이용하여 황사입자들의 크기와 모양을 조사하였다. 황사가 진할 때에는 약할 때보다 입자크기가 증가함을 보여주었다. 또한 비가 올 때에는 건조할 때보다 입자크기가 감소하였는데, 이는 입자 표면에 흡착되어 있는 성분들이 빗물에 의해 제거되었기 때문인 것으로 보여진다. 본 연구의 결과는 Sd/StFFF가 황사와 같이 환경입자의 크기특성분석에 유용함을 보여준다.

• 한국산업보건학회지
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• 제7권2호
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• pp.196-208
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• 1997

This study was performed to estimate quartz contents in the both bulk and airborne dust samples and to determine particle size distribution of airborne dust from the selected foundry operations. Total dust samples were collected by a 37mm cassette and respirable by a 10 mm nylon cyclone. Particle size distributions were determined by a Marple's 8-stage cascade impactor at the melting, molding, shakeout and finishing operations. The presence of elements in the dust samples were confirmed by the scanning electron microscopy equipped with the energy dispersive x-ray spectrometry. The quartz contents were estimated using the intensity of the absorption peak of quartz at 799 cm-l by the Fourie Transformed Infrared Spectroscopy (FTIR). The results were as follows: 1. The analysis of data from cascade Impactor showed bimodal distributions of particle size at the melting, molding and shakeout operations. Mass median aerodynamic diameters for the distributions determined by histogram were $0.48-1.65{\mu}m$ for small and $13.43-19.58{\mu}m$ for large modes. In the dust samples collected at the finishing operations, however, only a large mode of $18.89{\mu}m$ was found. 2. The percentages of total to respirable dust concentration calculated from the impactor data ranged from 42 % to 66 %. The average concentrations of respirable dust by cyclone were $0.85-1.28mg/m^3$ collected from the workers, and were $0.23-0.56mg/m^3$ from the areas surveyed. Dust concentrations of personal samples were statistically significantly higher than those of area samples. The highest dust concentration was obtained from the personal samples of the finishing operation. 3. The mean percentages of silicon and oxygen estimated by SEM-EDXA in the bulk samples ranged from 35.83 % to 36.02 % and from 39.93 %-41.64 %, respectively. 4. The average quartz contents estimated by FTIR in the respirable dust from personal samples ranged from 4.32 % to 5.36 % and 4.54 % to 4.70 % in the bulk samples. No statistical difference of quartz content was found between foundry operations. In this study, quartz content was quantified by FTIR. Although no statistically significant difference in quartz content between airborne and bulk, samples and between different foundry operations was found, it is recommended that quartz content in the individual sample of respirable dust be analyzed and the results be used either to select an applicable quartz limits or to calculate the exposure limit. Further studies, however, are needed to compare the results by FTIR and XRD since it is reported that the quartz content determined by FTIR is different from that by XRD.

• 천문학회보
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• 제38권2호
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• pp.59.2-59.2
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• 2013

The luminosity evolution of Type Ia supernova (SN Ia) and dust extinction play major roles in the systematic uncertainties in the SN cosmology. In order to overcome these obstacles, here we propose to use GMT-GMACS to take spectra for early-type host-galaxies of SNe Ia in the redshift range between 0.2 and 1.0. This high-redshift sample will be taken from Dark Energy Survey (DES), which expects more than 200 early-type hosts at this redshift range. They will be compared with nearby early-type hosts, for which we are now obtaining low-resolution spectra. We will select host-galaxies of same population age range for both nearby and high-redshift samples to reduce the possible evolution effect. Since we are dealing with early-type galaxies, our test is also less affected by dust extinction. We expect that our evolution-free and dust-free dark energy test will provide more robust results on the nature of dark energy.

• 자원리싸이클링
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• 제9권1호
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• pp.21-26
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• 2000

고탄소페로망간을 중.저탄소페로망간으로 제조하는 AOD공정의 Bag filter에 포집된 분진은 약 90%가 $Mn_3O_4$인 망간산화물이다. 분진의 입도는 5$\mu\textrm{m}$이하이고, 입자들은 직경이 10nm정도인 미립자들의 응집체로서 구형이다. 분진에서 망간을 질산으로 침출할 때의 최대침출율은 약 67%이며,비정질의 $MnO_2$가 잔류한다. 침출속도는 온도가 증가함에 따라 빨라지고 고농도의 질산에서는 늦어졌다. 침출속도를 여러 침출모델에 적용한 결과는 pore diffusion model에 일치하였다.