• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2001년도 추계학술발표회
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• pp.99-102
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• 2001

The soil-to-air fluxes of three PAHs(Phenanthrene, Pyrene, Benzo(a)pyrene) from a laboratory contaminated forest soil were investigated in experimental microcosms. The effects of soil temperature(45$^{\circ}C$, $25^{\circ}C$, 5$^{\circ}C$) and relative humidity(0%, 100%) were investigated according to existence of the humic layer(O layer) over the mineral layer(A layer). Volatilization flux experiments were carried out for a period of 96 hrs. The resulting PAHs volatilization fluxes from the different conditions were quantified and compared. In the mineral layer, highest volatilization flux among the individual PAHs was Phenanthrene >Pyrene> Benzo(a)pyrene on the conditions of 45 $^{\circ}C$, RH=100%. In the humic layer over the mineral layer, maximum volatilization flux was Phenanthrene on the condition of 45$^{\circ}C$, RH=0%. Results from flux experiments showed that volatilization fluxes of PAHs were dependent on soil temperature. Existance of humic layer over the mineral layer delayed transportation to the air of especially heaveir molecular PAHs. But, if humic layer is contained water sufficiently, it is possible that volatilization fluxes are enhanced by water convective flux according to variation of soil temperature and air relative humidity.

• 한국토양환경학회지
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• 제5권1호
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• pp.13-23
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• 2000

본 연구에서는 유류가 오염된 토양을 복원하기 위해 실제 현장의 토양성상과 오염현황을 조사하고 이 자료를 바탕으로 in situ복원기술인 토양증기추출법을 적용할 때 복원효율에 영향을 미치는 토양증기추출 장치의 운전조건과 토양성상의 영향을 검토하였다. 본 부지는 지하저장고에서 누출된 휘발유가 오염되어 있었고 그 농도는 BTEX가 최대 1.081ppm, TPH가 최대 5,548ppm이 포함되어 있었으며, 장기간에 걸쳐 지하 6m깊이까지 확산되어 오염물의 분포 면적은 170$\textrm{m}^2$, 오염토양의 총 부피는 약 1,000$\textrm{m}^3$으로 추산되었다. 오염부지의 토양은 지하 3~4m까지는 사질매립토이고 지하 4~6m에서는 불균질한 점토질이 섞인 미사토였으며 토양의 공기투수계수는 1.058-1.077$\times$$10^6$$\textrm{mm}^2$이었다. 이 부지내 일부지역에 지하수 흐름이 있으며 지하수위는 지하 약 3~4m부터 존재하였고 지하6m이하에는 암반이 존재하였다. 이 부지에 깊이 6m인 8개의 추출정과 7.5마력 용량의 진공펌프가 포함된 토양증기추출 장치를 설치하여 하루 8시간씩 100일간 운전한 결과 지하수가 존재하지 않는 사질토양에 있었던 BTEX는 90%이상의 효율로 제거하였으나 지하수대가 존재하는 지역에서는 BTEX와 TPH의 제거효율이 대폭 낮아졌다. 또한 토양증기장치에 의해 유도된 토양내 공기흐름은 토양깊이가 깊어질수록 공기 흐름량은 감소하여 복원효율이 떨어졌다.

• Journal of Radiation Protection and Research
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• 제39권2호
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• pp.89-95
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• 2014

원전의 인허가 승인을 위한 사고결말평가에서 경수로는 미국의 규제지침에서 제시한 바와 같이 방사성물질의 지표침적의 고려를 허용하지 않고 있는데 반해 중수로의 규제지침에서는 이의 고려를 허용하고 있다. 이러한 배경에 따라 본 연구에서는 방사성물질의 지표침적에 의한 피폭영향의 민감도를 정량적으로 고찰, 분석하였다. 가상사고 시나리오를 구성하여 Cs-137과 I-131의 환경방출에 따른 총 피폭선량을 평가한 결과, 방사성물질의 지표침적과 이로 인한 공기중 농도의 감손을 고려치 않는 경우에 보다 보수적 결과를 나타냈다. 이는 지표침적에 의한 피폭선량이 총 피폭선량에 미치는 기여는 상대적으로 적은데 비해 지표침적으로 인한 공기중 농도의 감손이 총 피폭선량에 미치는 기여는 상대적으로 크기 때문이다. 대기안정도, 방출기간, 평가거리 등에 따라 차이는 있지만 두 핵종 모두 총 피폭선량에 대해 흡입에 의한 피폭이 90% 이상을 차지했으며, 지표침적에 의한 피폭은 기껏해야 10% 미만을 나타냈다. 지표침적의 고려에 따른 총 피폭선량의 감소는 $^{137}Cs$ 보다는$^{131}I$의 경우에 보다 컸으며, 대기가 안정하고 방출기간이 길수록, 그리고 방출점으로부터 평가지점이 멀수록 감소경향은 보다 뚜렷하게 나타났다.

• 한국안전학회지
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• 제21권5호
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• pp.28-33
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• 2006

The rapidly advanced industrial society takes advantage of high-technology, but it also suffered from the side effects such as various diseases by contamination. Of these problems, air pollution is considered as the most important problem nowadays. Air contamination is not only limited outdoors, but it also causes more serious effect in our indoor air environment. Depending on the notion that indoor air effects physical health seriously, the needs of the air cleaner is more earnest. Therefore, the main purpose of this study is to develop the air cleaner to meet the standard and get rid of poisonous and harmful material from the atmosphere by using a Corona Discharge. According to the purpose of this study, We set the negative ion generator, the UV, $TiO_{2}$ optical catalyzer, the electrical dust collector and the air filter in series order. It emits a lot of negative ions. We use these ions to purify harmful factors and contaminated materials. We collect the dust using static power that comes from the discharge of corona. At the same time, we try to develop the air cleaner to keep the air quality to meet the standard and kill the various viruses using UV LED and $TiO_{2}$ optical catalyzer. In this study, we use the UV LED that is smaller and efficient than a existing UV lamp. What is more, the UV LED has a features that a stabilizer occupying much space is not needed any more.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2008년도 추계학술대회 논문집
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• pp.299-300
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• 2008

• 한국독성학회:학술대회논문집
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• 한국독성학회 2002년도 Current Trends in Toxicological Sciences
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• pp.69-70
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• 2002

Arsenic (As) is a ubiquitous element found in several forms in foods and environmental media, such as soil, air, and water. The primary route of human exposure is through ingestion of arsenic-contaminated food and drinking water. The predominant form of arsenic in drinking water is inorganic arsenic, which is both highly toxic and readily bioavailable.(omitted)

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2003년도 추계학술대회 논문집
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• pp.199-199
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• 2003

During the cleanup of US Department of energy facilities, contaminated materials, toxic and hazardous radionuclides (e.g., Th, Cs, and U) and heavy metals (e.g., Cr, Hg, Pb, and Ni)-laden ultrafine particles are generated. The size of the particles is up to about 200 nm. Understanding of the production of these nanometer size particles is critical in determining the surface cleaning efficiently. (omitted)

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.77-80
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• 2001

Groundwater, contaminated predominantly with aromatic compounds and chlorinated ethylene, could be biologically treated in a fluidized-bed reactor with immobilized cells. The decomposition efficiency for the aromatics was over 90% at the retention time of 2.5 h. The chlorinated ethylenes, especially trichloroethylene (TCE) and cis-dichloroethylene (DCE), could be decomposed only insufficiently. No anaerobic methane formation was observed for this groundwater even at a very low dissolved oxygen (DO) concentration of 0.75 mg/L. The variation of DO concentration resulted in an optimal value of 1.5 mg/L. The recycle of air waste could increase the utilization of oxygen. The amount of low boiling pollutants stripped out remained constant with the recycle, while for the higher boiling pollutants the stripping slightly increased. Using air instead of oxygen increases the flow rate of air waste, which is connected to a higher stripping of pollutants. In this investigation, the pollutant concentration in the air waste remained constant. The stripping of main pollutants did not exceed 0.3 %.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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• pp.555-558
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• 2006

In recent years, urban development has expanded rapidly in Nawabshah City of Pakistan. A major effect associated with this population trend is transformation of the landscape from natural cover types to increasingly impervious urban land. The core objective of this study are to provide time-series information to define and measure the urban land cover changes of Nawabshah, Pakistan between the years 1992 and 2002, and to examine related urbanization impacts on air quality of the study area. Two multi-temporal Landsat images acquired in 1992 and 2002 together with standard topographical maps to measure land cover changes were used in this study. The image processing and data manipulation were conducted using algorithms supplied with the ERDAS Imagine software. An unsupervised classification approach, which uses a minimum spectral distance to assign pixels to clusters, was used with the overall accuracy ranging from 84 percent to 92 percent. Land cover statistics demonstrate that during the study period (1992-2002) extensive transformation of barren and vegetated lands into urban land have taken place in Nawabshah City. Results revealed that land cover changes due to urbanization has not only contaminated the air quality of the study area but also raised the health concerns for the local residents.

• Food Science and Biotechnology
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• 제15권1호
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• pp.57-62
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• 2006

Six organophosphorus, one organochlorine, and three synthetic pyrethroid pesticides were analyzed for their residues during washing and hot-air drying of red peppers conducted in the production of powder. The residue ratio in organophosphorus pesticides was 33% in chlorpyrifos, 31 % in diazinon, 50% in methidathion, 80% in EPN, 28% in fenitrothion, and 60% in profenofos. The ratio in pyrethroids was 109% in cypermethrin, 102% in deltamethrin, and 106% in fenvalerate. That in organochlorine was 56% in ${\alpha}$-endosulfan and 90% in ${\beta}$-endosulfan. The results were greatly different between organophosphorus and pyrethroid pesticides. UV irradiation along with hot-air drying brought about a remarkable reduction of the residues, up to 70% as compared with hot-air drying only. The removal effect was most remarkable in pyrethroids, which are hardly removed by hot-air drying. The color of the pepper was not changed during UV irradiation. The use of oxidizing agents such as hydrogen peroxide or chlorine dioxide during washing did not show a remarkable removal of residues. The residue ratio was not affected whether the pesticide is contaminated artificially or naturally.