• Environmental Analysis Health and Toxicology
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• 제13권1_2호
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• pp.43-53
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• 1998

Ambient air levels of polycyclic aromatic hydrocarbons(PAHs) are of concern because of their potential for adverse health effects including transformation of some of these substances to mutagens and carcinogens by mammalian microsomal enzyme system. Airbone particulate samples were collected by a conventional high-volume sampler and by an Anderson cascade impactor on 2 to 3 days in each month over a period of 1 year at a representative site of the heavy traffic area of Seoul from beptember 1994 to August 1995. Ten individual PAHs in sizable air particulates of each stage of two months were separated and analyzed by gas chromatography/mass spectrometry. As a results of analysis, the gross concentrations of PAHs in the fine and coarse particles were higher in the winter month than in the spring, followed in descending order by in the fall and summer. In a study of dependency of 10 PAHs compounds on size distribution of particles at heavy traffic area found that about 85% of the total PAHs content was associated with particles less than 2.0um (fine particles) in diameter of winter sampling period. while 79% were associated with this size fraction during summer period. In according to the mean concentrations of the 10 PAHs in 7 size classification from < 0.38 to> 10.1, the 'size was the smaller, PAHs concentration was the higher. Thus it was found that PAHs concentration was greatly affected by air particle size. Annual mean benzo(a)pyrene equivalents was 5.88ng/m$^3$ and obtained by applying, toxic equivalency factor developed by Nisbet and Lagoy.

• The Korean Journal of Ecology
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• 제22권1호
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• pp.59-63
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• 1999

사철쑥에 함유되어 있는 천연 화학물질이 다른 식물에 미치는 효과를 구명하기 위하여 실험식물의 종자발아와 생장실험을 수행하고 사철쑥의 화학성분을 분석했으며, 그 성분과 동일한 시약으로 생물학적 정량을 실시하였다. 사철쑥의 수용추출액에 의한 발아율은 실새풀, 이고들빼기와 왕고들빼기는 수용추출액의 농도가 증가함에 따라 비례적으로 감소했으나, 그러나 코스모스와 익모초는 70% 실험구와 100%, 10%구와 30%에서 서로 반대로 나타났다. 유식물의 건중량은 추출액의 농도가 증가함에 따라 감소현상이 뚜렷하였다. 사철쑥의 정유의 농도에 따라 쑥과 질경이는 정유농도가 증가함에 따라 생장은 억제되었고 유근보다 유묘에서 더욱 확실하였다. GC로 사철쑥의 정유를 분석하여 36종류의 화학물질을 분리확인하였고 이들중 7종류를 선정하여 생물학적 정량을 실시한 결과 terpinen-4-ol이 가장 강한 억제작용이 있었다.

• 한국건설순환자원학회논문집
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• 제3권4호
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• pp.328-334
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• 2015

건축용 단열재는 에너지 절약을 목적으로 적용되며 불연 및 내화성능이 요구되는 부위는 무기계 섬유를 주재료로 사용하는 미네랄울 및 글라스울 소재가 적용된다. 하지만 무기계 소재인 미네랄울이나 글라스울은 특성상 수분에 취약하여 뭉침 및 처짐 현상 등이 발생하여 단열효과가 떨어지며 유기계 소재인 폴리스티렌폼이나 우레탄폼 등은 화재에 취약하고 일산화탄소 발생에 의한 가스유해성 등으로 적용에 한계를 갖고 있다. 본 연구에서는 폐유리분말과 플라이애시를 사용하여 가볍고 열전도율이 낮은 무기계 경량 발포소재를 제조하고 물리적 특성을 분석하여 단열용 제품으로서의 가능성을 확인하고자 하였다. 연구결과 폐유리분말과 플라이애시를 사용한 경량 발포소재는 균일한 공극을 형성하며 발포하였고 경량이며 불연재료이므로 불연성능 요구되는 부위에 사용이 가능하다.

• Korean Chemical Engineering Research
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• 제45권4호
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• pp.319-327
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• 2007

소각은 유기성 유해폐기물에 대해 가장 발달된 유용한 처리기술로 인정되어 왔다. 그러나 PCBs와 같이 유해한 폐기물의 처리를 위한 소각로의 부지확보나 인허가가 유해한 대기오염 물질의 배출에 대한 주민의 우려로 용이하지 않다. 최근에 많은 소각 대체기술들이 개발되어 왔으며 이 기술들은 소각에 비해 다이옥신이나 퓨란과 같은 유해한 물질의 배출이 적어 주민의 우려를 완화시킬 수 있다. 본 논문에서는 다양한 유해폐기물의 종류에 대해 현재 적용이 가능한 소각 대체기술들을 검토하였다. 다양한 범주의 비열처리 및 열처리 소각 대체기술들을 공정운전조건, 적용대상 폐기물 및 이차폐기물 발생특성의 관점에서 평가하고 몇 가지 소각 대체기술들에 대해서는 공정의 운전원리에 대해 자세히 설명하였다.

• 청정기술
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• 제2권2호
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• pp.100-125
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• 1996

After recycle of spent materials has been optimised, there remains a proportion of waste which must be dealt with in the most environmentally friendly manner available. For materials such as municipal waste, clinical waste, toxic waste and special wastes such as tyres, incineration is often the most appropriate technology. The study of incineration must take a process system approach covering the following aspects: ${\bullet}$ Collection and blending of waste, ${\bullet}$ The two stage combustion process, ${\bullet}$ Quenching, scrubbing and polishing of the flue gases, ${\bullet}$ Dispersion of the flue gases and disposal of any solid or liquid effluent. The design of furnaces for the burning of a bed of material is being hampered by lack of an accurate mathematical model of the process and some semi-empirical correlations have to be used at present. The prediction of the incinerator gas phase flow is in a more advanced stage of development using computational fluid dynamics (CFD) analysis, although further validation data is still required. Unfortunately, it is not possible to scale down many aspects of waste incineration and tests on full scale incinerators are essencial. Thanks to a close relationship between SUWIC and Sheffield Heat&Power Ltd., an extended research programme has been carried out ar the Bernard Road Incinerator plant in Sheffield. This plant consists of two Municipal(35 MW) and two Clinical (5MW) Waste Incinerators which provide district heating for a large part of city. The heat is distributed as hot water to commercial, domestic ( >5000 dwelling) and industrial buildings through 30km of 14" pipes plus a smaller pipe distribution system. To improve the economics, a 6 MW generator is now being added to the system.

• 한국추진공학회지
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• 제20권2호
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• pp.31-38
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• 2016

세계적으로 사용 중인 대부분의 추진물질들은 연소 시 메탄가스, 이산화탄소 등의 환경유해 물질을 다량 발생시킨다. 본 연구에서는 이러한 문제를 개선하기 위해 에너지 가소제로 사용 가능한 고질소 화합물인 트리아졸 계열의 4,5-bis(azidomethyl)-methyl-1,2,3-triazole(DAMTR)의 합성공정을 확립하였다. 또한, 분광분석(NMR, IR)을 통해 DAMTR의 구조를 분석하였고, 유리전이온도, 녹는점, 분해온도, 밀도, 점도, 충격감도, 점도, 휘발성 등의 물리적 특성을 측정하였다. 그리고 Gaussian 09와 EXPLO5를 이용하여 생성열과 폭발 특성(폭압, 폭속) 등을 계산하였다.

• 대한임상독성학회지
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• 제15권2호
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• pp.86-93
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• 2017

Purpose: Some advanced countries have reported annual statistics for poisoning based on data from poison control centers. This study was conducted to propose a baseline format and statistics of poisoning in Korea from a national representative database. Methods: This study was a retrospective analysis of poisoning patients based on data from an emergency department (ED) based injury in-depth surveillance project by the Korea Centers for Disease Control and Prevention in 2016. Bite or sting injuries were not included. Variables related to poisoning were summarized using a similar format as the National Poison Data System in the United States. Results: A total of 7,820 poisoning patients presented to 23 EDs. Adults ${\geq}20$ years accounted for 84% of the population, while the proportion of intentional poisoning was 59.4%. The most common poisoning substances were therapeutic drugs (45%), gas (21%), pesticides (15%), and artificial toxic substances (13%). Overall, 34.5% of patients were admitted for further treatment. The mortality was 3.2% (248 cases), and the most common causative substances were carbon monoxide, glyphosate, and paraquat, in order. Conclusion: This study showed the recent status of poisoning in Korea. However, a comprehensive poisoning registry based on poison control centers may be required to provide more accurate national statistics in the future.

• 한국환경과학회지
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• 제12권11호
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• pp.1167-1171
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• 2003

Polycyclic aromatic hydrocarbons (PAHs) are an important group of organic contaminants present in sewage sludge, due to their persistence, toxic, bioaccumulative and long range transfer. These characters make themselves as Persistent Organic Pollutants(POPs) in Long Range Transboundary Air Pollutions convention(LRTAP) of Europe. A method of the gas chromatographicmass spectrometric (GCMS) determination of PAHs present in sewage sludge was developed and applied to analyzed samples from five sewerage treatment plants (SWTPs), having different treatment types. PAHs were extracted from freeze-dried samples by toluene 16 hours in a soxhlet extraction system. The sludge extracts were cleaned-up by an activated silica gel column chromatography. The sum of the 16 US Environmental Protection Agency PAHs sewage sludge samples varied from 2.44 to 4.82 $\mu\textrm{g}$/g. Concentration of emission carcinogen PAHs(PAHcarc), such as Benzo(a)anthracene, Benzo(b)f1uoranthene, Benzo(k)f1uoranthene, Benzo(a)pyrene, Dibenzo(a,h)anthracene and Indeno( 1,2,3-cd)pyrene ranged from 0.62 to 1.03 $\mu\textrm{g}$/g. The total amount of PAHs emission from sewage sludge in Korea was calculated as a top-down approach. PAHs and $\Sigma$PAHcarc from sewage treatment plants had emitted to environment by several pathway. The highest amount of emission to the environment was remarked in the ocean dumping(PAHs and $\Sigma$PAHcarc emissions were 1155.95 kg/year and 5040.32 kg/year, respectively).

• KSBB Journal
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• 제26권5호
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• pp.471-476
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• 2011

Nowadays biodiesel (fatty acid methyl ester, FAME) has been becoming an important issue as a desired alternative of energy products because of non-toxic, biodegradable properties, and lower exhaust emissions. During esterification of fatty acids or transesterification of oils and fats with short chain alcohols by the alkali-catalyzed methanolysis, FAME and unrefined glycerol are generated. Quantification of glycerol as a by-product is important because of a determinant of biodiesel quality. However, the glycerol analysis by gas chromatography (GC) method has laborious works with sample preparation, long time and cost of sample analysis. Thus, there is a need to analyze glycerol more simply. Herein we demonstrate that the colorimetric assay for glycerol analysis conducted by UV-vis spectrophotometer at the wavelength 617 nm whose peak is maximum intensity of malachite green, resulting in the red-shift occurred proportionally as a function of glycerol amount. Thus, it is considered the solvent media for malachite green fading for biodiesel production: (1) water, (2) MeOH, and (3) EtOH. The resulting findings show that the peak intensity at 617 nm in glycerol-malachite green mixture had a relationship between glycerol concentration and degree of peak shift as increase in pure glycerol concentration approximately at pH 7.0. However, when it was measured the unrefined glycerol concentration by diluting and adjusting with water to buffer (pH 7.0), it was not observed the absorption peak at 617 nm because of impurities and OH ions. In case of glycerol from biodiesel production factories, glycerol concentration could be successfully measured.

• Current Photovoltaic Research
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• 제3권4호
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• pp.135-139
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• 2015

$Cu_2SnS_3$ (CTS) based thin film solar cells (TFSCs) are of great interest because of its earth abundant, low-toxic and eco-friendly material with high optical absorption coefficient of $10^4cm^{-1}$. In this study, the DC sputtered precursor thin films have been sulfurized using rapid thermal annealing (RTA) system in the graphite box under Ar gas atmosphere for 10 minute. The systematic variation of sulfur powder during annealing process has been carried out and their effects on the structural, morphological and optical properties of CTS thin films have been investigated. The preliminary power conversion efficiency of 1.47% with a short circuit current density of $33.9mA/cm^2$, an open circuit voltage of 159.7 mV, and a fill factor of 27% were obtained for CTS thin film annealed with 0.05g of S powder, although the processing parameter s have not yet been optimized.