We measured ambient concentrations of hazardous air pollutants such as volatile organic compounds (VOCs) and aldehydes in residential areas nearby small and medium scale shipbuilding companies. The VOC concentrations were higher during the normal operation periods than vacation at which almost all operations were shutdown. Concentrations of VOCs was higher, as the sampling site was nearer from shipbuilding companies. The major components of VOCs were m,p-xylene, ethylbenzene, o-xylene, toluene, and 1,3,5-trimethylbenzene which had been found as major VOC compounds emitted from painting processes of shipbuilding in the previous studies. The major components of aldehydes analyzed were benzaldehyde, acrolein, formaldehyde, and acetaldehyde. The concentration of aldehydes was highest at the furthest sampling point from shipbuilding companies because the formation of aldehyde compounds could be occurred by the secondary chemical reactions of VOCs. The results of this study shows a proper counterplan need to be established for the reduction of hazardous air pollutants emitted from small and medium scale shipping companies.
This study was aimed to behaviour of organics and nitrogen on the upflow anaerobic reactor when a acid fermenter is added. Upflow anaerobic reactor (UAR) reaction will result which operates, COD removal efficiencies of reactor with nitrate loading rate 0.11, 0.66g/L/d were over 77%, but one with 1.0g/L/d was 73.5%. Especially, on NLR 0.11g/L/d, COD removal was 77% and nitrate removal efficiency was 93% simultaneously. The other side upflow anaerobic reactor and acid fermenter (UAR+AF) reaction will result witch operates, COD removal efficiencies of reactor with nitrate loading rate 0.11, 0.66g/L/d were over 85%, but one with 1.0g/L/d was 80%. Especially, on NLR 0.11g/L/d, COD removal was 85% and nitrate removal efficiency was 98% simultaneously. Also, without in reaction condition increase of influent nitrate concentration resulted in the linear decrease of nitrate removal efficiency and nitrate removal efficiency at influent nitrate-nitrogen 800mg/L was 50%. Alkalinity was increased theoretically by denitrification at low nitrate-N concentration, however, it was not increased theoretically at high nitrate-N. 40% nitrate-N of UAR was denitrified until 70% height of reactor and 90% nitrate-N of UAR+AF was denitrified until 30% height of reactor Upflow anaerobic reactor was to occur accumulate acid, which TVA/Alkalinity is 0.3~0.47. Increase of NLR resulted increase of effluent alkalinity and TVA production
피부주름 개선에는 콜라겐(collagen)뿐만 아니라 탄력섬유인 엘라스틴(elastin) 등도 기여하는 것으로 보고되고 있다. 더 나아가 자외선에 의하여 사람의 피부에서 광노화 현상이 나타나며 자외선 조사 후 엘라스타제(elastase)의 활성이 증가하기 때문에 엘라스타제의 활성증가는 자외선에 의한 피부 탄성도의 감소 및 주름 생성의 주요원인으로 생각된다. 따라서 본 연구에서는 피부주름 생성에 영향을 미치는 엘라스타제의 활성을 측정하기 위한 모델을 마련하기 위하여 시판되는 두 가지 엘라스타제, 돼지 췌장 엘라스타제(porcine pancreatic elastase)와 사람 호중구 엘라스타제(human neutrophil elastase)를 사용하였으며 다음 세 가지는 정상 사람 섬유아세포(normal primary human fibroblasts), 쥐의 3T3 섬유아세포주(3T3 mouse fibroblasts), 사람의 CCD-25Sk 섬유아세포주(CCD-25Sk human fibroblasts)로부터 elastase를 준비하여 사용하였다. 준비된 5가지 효소의 농도에 기질의 농도 및 배양시간에 따르는 효소의 활성을 비교 평가하였다. 양성대조군으로 사용한 phosphoramidon이 normal human primary fibroblast elastase와 CCD-25Sk fibroblast elastase의 활성을 유의성 있게 억제한 반면에 porcine pancreatic elastase에는 별다른 영향을 미치지 못하였다. 따라서 주름 개선 후보물질 탐색을 위한 엘라스타제의 선정에는 신중한 고려가 필요할 것으로 사료된다.
본 연구에서는 헤테로 접합을 이용하여 누설전류를 저감 시키는 기술을 적용하여 Particle-In -Binder을 이용한 방 사선 영상 센서의 변환 물질을 개발하였다. 이는 디지털 방사선 영상 검출기의 두 가지 방식 중 하나인 직접방식에 사 용되는 핵심 소자로 기존의 비정질 셀레늄(Amorphous Selenium)을 대체하여 더욱 효율이 높은 후보 물질들이 연구되 어지는 가운데 태양전지와 반도체 분야에서 이미 많이 사용되어온 이종접합(Hetero junction)을 이용해 누설 전류를 저감 시키는데 그 목적이 있다. 본 연구에서 사용되는 Particle-In -Binder 제작 방법은 검출 물질 제작이 용이하고 높은 수율과 대면적의 검출기 제작에 적합하나 높은 누설 전류가 의료 영상 시스템에 있어서 문제가 되어 오고 있다. 이러한 단점을 보완하기 위해 다층 구조를 이용하여 누설 전류를 저감시킨다면 Particle-In -Binder을 이용하여 간편 하게 향상된 효율의 디지털 방사선 검출기를 제작 할 수 있다고 사료 되어 진다. 본 연구에서는 누설전류 및 민감도, 그리고 선형성에 대한 전기적 신호를 측정하여 제작된 다층 구조의 방사선 검출 물질의 특성 평가가 이루어 졌다.
Micropollutants, which can be caused by imperfect combustion, are toxic chemical compound that flows into the river system after being contained in road runoff, a non-point source pollutant and accumulates in the body. The micropollutants that have characteristics such as toxicity, persistence, bio-accumulation, long-range transportation behave so similarly to micro particles that they can be removed by means of filtration or absorption. This study has examined the kinds and concentrations of micropollutants contained in deposited road particles. It has revealed that the kinds of micropollutants contained in the clarified supernatant liquid of deposited road particles are heavy metals and polycyclic aromatic hydrocarbons(PAHs) composed of two or three benzene rings, including naphthalene and acenaphthalene. Their concentrations have been shown to be low, with 0.418 mg/L, 0.058 mg/L, 0.104 mg/L, 0.014 mg/L, 0.00075 mg/L for Zn, Pb, Cu, Cr, Cd, respectively and 0.00156 mg/L and 0.00184 mg/L for naphthalene and acenaphthalene.