• 설비공학논문집
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• 제20권5호
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• pp.327-333
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• 2008

The purpose of this study is to develop a paddle-type dryer and to commercialize the dryer, in which mixing and drying can be done simultaneously. According to a performance test, a newly-designed paddle-type dryer can dry Chitosan salt to a low moisture contents below 0.3%. Also the newly-designed dryer can dry air pollution materials, because the dryer can operate in a closed system. The economic efficiency of a newly-designed system and an existing system was compared in a performance test. As a result, the economic efficiency of a newly-designed system was higher than an existing system. In conclusion, it is thought that the newly-designed system has a high commercial value.

• 대기
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• 제27권1호
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• pp.29-40
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• 2017

The $PM_{10}$ and $PM_{2.5}$ particles over the Yellow Sea of Korea were collected by ship-borne observation during two cruises in spring, 2015. Their water-soluble ionic components such as $NH_4^+$, $Na^+$, $K^+$, $Mg^{2+}$, $Ca^{2+}$, $SO_4^{2-}$, $NO_3^-$, $Cl^-$, $F^-$, $CH_3COO^-$, $HCOO^-$, and $CH_3SO_3^-$ were analyzed, in order to examine the pollution characteristics of the secondary aerosol components. The comparative study of particle size distribution has resulted that $NH_4^+$, $nss-SO_4^{2-}$, $nss-Mg2+$, $nss-K^+$, $HCOO^-$, and $CH_3SO_3^-$ species mostly existed in fine particle mode. Meanwhile, nss-F-and sea-salt species were distributed in both fine and coarse particle mode, $NO_3^-$, $nss-Ca^{2+}$, $CH_3COO^-$ species were rich in coarse particle mode. The concentrations of secondary pollutants($nss-SO_4^{2-}$, $NO_3^-$, $NH_4^+$) increased in fine particles, and those of natural components ($nss-Ca^{2+}$, Sea-salt) increased in coarse particles. $NH_4^+$ exists as the form of $(NH_4)_2SO_4$ and $NH_4NO_3$, and mostly as $(NH_4)_2SO_4$ in fine particles. $NH_4NO_3$ has lower content compared to $(NH_4)_2SO_4$, and it mostly existed in fine particles at Yellow Sea I and in coarse particles at Yellow Sea II. The concentration ratios of $NO_3^-/nss-SO_4^{2-}$ for Yellow Sea I and Yellow Sea II were 0.52 and 0.16 in coarse particles, and they were 0.64 and 0.38 in fine particles, respectively, showing that the stationary source emissions were more important than mobile source emissions in Yellow Sea II (except Passage II-4).

• 한국산업융합학회 논문집
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• 제5권1호
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• pp.75-80
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• 2002

In this study, the initial number of bacteria before ozone sterilizing shows 290 per $1m{\ell}$ in RUN 1 and RUN 2 equally, but the removal rate shows more than 50% in RUN 1, and 100% in RUN 2 respectively when ozone injection amount is $0.28mg/{\ell}$. It is regarded as a satisfactory result that E-coli concentration without ozone contact is 890, rapid removal effect of E-coli is observed in $0.28mg/{\ell}$ of ozone, and E-coli is removed perfectly in $0.84mg/{\ell}$ of ozone. It is thought that an excellent efficiency is obtained for vibrio alginolyticus because the initial number of bacteria before ozone contact is positive, but it is altered to negative after ozone contact. CODcr shows the tendency which is somewhat reduced as the ozone injection is increased, but the general effect is appeared not so much, and it is thought that the tendency is caused by the reason that sea water contains much salt which is estimated as a component of CODcr, therefore it is regarded that ozone contact has not an important effect on salinity. It is thought that the frequency of changing salt water in the fish preserve of a sliced raw fish restaurant can be reduced to under the standard because NTU of 7 days after sea water injection is 0.70 in the experiment of turbidity, hut more than 50% of turbidity removal efficiency is appeared at $0.28mg/{\ell}$ of ozone injection, and it shows 70% at $0.84mg/{\ell}$ of ozone injection in RUN 1 and RUN 2 commonly.

• 한국해안해양공학회지
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• 제15권4호
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• pp.259-268
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• 2003

Kitan 해협을 포함하는 Seto내해(inland sea)에서는 COD, 인 등에 관한 총량규제가 실시됨에도 불구하고 적조현상과 빈산소 수괴 현상이 매년 발생하고 있는데, 그 원인으로서 저니로부터의 용출과 부영양화에 따른 1차 생산의 증가가 주목되고 있다 또한 최근의 조사결과는 수질오염의 원인이 되는 질소와 인과 같은 영양염이 육지뿐만 아니라 태평양으로부터도 유입되고 있다는 것을 보여주고 있다. 본 연구에서는 Osaka만과 Kii수로를 연결하는 Kitan해협에 있어서 유동구조와 물질수송구조의 실태를 명확히 밝히기 위해 현지관측을 실시하였으며, 기 출판된 자료와 함께 연구대상 해역의 오염원인을 규명하고자 하였다. 현지조사는 1999년부터 2002년 사이에 걸쳐 실시되었으며, 자료의 획득은 각 계절을 대표하는 2월, 5월, 8월, 11월에 각각 이루어졌다.

• Asian Journal of Atmospheric Environment
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• 제11권2호
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• pp.122-130
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• 2017

The main purpose of the study was to clarify the properties of individual particles collected at each behavior space of a factory worker. The samplings of size-segregated ($PM_{2.1-1.1}$ and $PM_{4.7-3.3}$) indoor particles were conducted at three different behavior spaces of a factory worker who is engaged in an auto parts manufacturing plant (i.e., his home, his work place in factory, and his favorite restaurant). Elemental specification (i.e., relative elemental content and distribution in and/or on individual particles) was performed by a micro-PIXE system. Every element detected from the coarse particulate matters of home was classified into three groups, i.e., a group of high net-counts (Na, Al, and Si), a group of intermediate net-counts (Mg, S, Cl, K, and Ca), and a group of minor trace elements (P, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, and Pb). The results of EF for $PM_{4.7-3.3}$ in home indicated that several heavy metals were generated from the sources within the house itself. An exceptional feature shown in the individual particles in workplace is that Cr, Mn, and Co were clearly detected in both fine and coarse particles. Cluster analysis suggested that the individual coarse particles ($PM_{4.7-3.3}$) collected at the indoor of factory were chemically heterogeneous and they modified with sea-salt, mineral, and artificially derived elements. The principal components in individual coarse particles collected at restaurant were sea-salt and mineral without mixing with harmful trace elements like chromium and manganese. Compared to the indoor fine particles of home and restaurant, many elements, especially, Cl, Na, Cr, Mn, Pb, and Zn showed overwhelmingly high net-counts in those of factory.

• 한국전기전자재료학회논문지
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• 제18권1호
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• pp.62-67
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• 2005

Recently, polymer insulators that are used for high voltage applications have some advantages such as light weight, small size, vandalism resistance, hydrophobicity and easy making process. During outdoor service of polymer insulators, the surface of the insulating material is frequently subjected to moisture and contamination that lead to dry band arcing. Their tracking resistance, erosion resistance, end sealing and shed design are very important because dry band arcing causes degradation of polymer surface. Aging test to estimate life property of polymer insulator is executed through several international standard such as IEC 61109 and CEA tracking wheel test, but is not getting clear conclusion yet. There are two methods in the diagnosis method of polymer insulator such as off-line and on-line. The diagnosis methods in off-line are external condition analysis by the eye, contaminant analysis on surface, surface analysis, pollution withstand voltage test, power frequency flashover voltage test, lightning impulse flashover test, tensile fracture load test and flexural load test. Polymer material is also investigated it's tracking resistance by adding surface active agent in IEC 587. In this paper, the tracking performance of polymer insulator with salt solution which is added surface active agent. The diagnosis of insulator sample has been analyzed by leakage current and visual examination, STRI guide and thermal image camera.

• 공업화학
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• 제23권6호
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• pp.567-571
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• 2012

전통회화의 변색은 온도, 습도, 빛, 그리고 대기 오염에 의한 각종 화학 물질들과 사용된 무기 안료와의 화학반응에 의해 일어나기도 한다. 본 연구에서는 조선종이라고 불리는 한지에 석록, 석청 무기 안료를 사용해 전통방법으로 시험편을 제작하고, 인위적인 노화시험을 통해 안료와 환경 요인의 상호 작용에 의한 노화과정을 조사하였다. 석청은 XRD 및 TGA 결과로부터 내후성 시험의 습기와 내염수 시험의 염무에 의해 영향을 받는 것을 알 수 있었다. 하지만 석록은 내후성 시험이나 내자외선 시험 중 주로 자외선에 의해 화학적 변화가 일어나는 것을 색차 및 TGA 결과로부터 볼 수 있었다.

• 한국응용과학기술학회지
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• 제36권3호
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• pp.905-914
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• 2019

본 연구에서는 PMF 모델을 이용하여 $PM_{2.5}$에 대한 오염원 확인 및 오염원별 기여도를 분석하였다. A시의 배출원별 기여도 순위는 Secondary Sulfate가 19.8%로 가장 기여도가 높고, 그 다음으로는 Mobile 19.5%, Industry 16.0%, Biomass Buring 14.1%, Secondary Nitrate 14.1%, Oil Combustion 11.6%, Aged Sea Salt 2.6%, Soil 2.5% 등으로 분석되었다. Sulfate와 Ammonium 농도가 배출원별 프로파일에서 기여도가 가장 높은 오염원으로 분석되었는데, 이는 대기 중에서 가스상 전구물질(SOx와 암모니아 가스)이 광화학 반응하여 생성된 2차 에어로졸인 것으로 분석되었다.

• 한국대기환경학회지
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• 제19권6호
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• pp.701-717
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• 2003

The objective of this study was to extensively estimate the air quality trends of the study area by surveying con-centration trends in months or seasons, after analyzing the mass concentration of PM-10 samples and the inorganic lements, ion, and total carbon in PM-10. Also, the study introduced to apply the PMF (Positive Matrix Factoriza-tion) model that is useful when absence of the source profile. Thus the model was thought to be suitable in Korea that often has few information about pollution sources. After obtaining results from the PMF modeling, the existing sources at the study area were qualitatively identified The PM-10 particles collected on quartz fiber filters by a PM-10 high-vol air sampler for 3 years (Mar. 1999∼Dec.2001) in Kyung Hee University. The 25 chemical species (Al, Mn, Ti, V, Cr, Fe, Ni, Cu, Zn, As, Se, Cd, Ba, Ce, Pb, Si, N $a^{#}$, N $H_4$$^{+}$, $K^{+}$, $Mg^{2+}$, $Ca^{2+}$, C $l^{[-10]}$ , N $O_3$$^{[-10]}$ , S $O_4$$^{2-}$, TC) were analyzed by ICP-AES, IC, and EA after executing proper pre - treatments of each sample filter. The PMF model was intensively applied to estimate the quantitative contribution of air pollution sources based on the chemical information (128 samples and 25 chemical species). Through a case study of the PMF modeling for the PM-10 aerosols. the total of 11 factors were determined. The multiple linear regression analysis between the observed PM-10 mass concentration and the estimated G matrix had been performed following the FPEAK test. Finally the regression analysis provided source profiles (scaled F matrix). So, 11 sources were qualitatively identified, such as secondary aerosol related source, soil related source, waste incineration source, field burning source, fossil fuel combustion source, industry related source, motor vehicle source, oil/coal combustion source, non-ferrous metal source, and aged sea- salt source, respectively.ively.y.

• 한국대기환경학회지
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• 제18권4호
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• pp.305-316
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• 2002

Various air pollutants were measured at Tokchok Island in the Yellow Sea that is about 50 km distant from Incheon since April 1999. This study was undertaken to help understanding the level of air pollution and its distribution characteristics over the Yellow Sea. The geographical characteristics of the air pollution monitoring station and emission inventories of Tokchok Island are introduced. The mass concentrations and chemical compositions of TSP and P $M_{2.5}$ measured until March 2000 are discussed in this paper. The overall average mass concentrations are about 37.2 $\mu\textrm{g}$/㎥ for TSP and 18.7 $\mu\textrm{g}$/㎥ for P $M_{2.5}$ , respectively, which are similar to or a little lower than the values observed in other background sites at Kangwha and Taean. However, they are much lower than those observed at Qingdao in China. The low mass concentration and major anthropogenic ion concentrations in aerosols collected at Tokchok Island show that local sources are not dominant at Tokchok Island. The estimated average fractions of anthropogenic non-sea-salt sulfate to the total sulfate concentration of TSP and P $M_{2.5}$ are greater than 80% for both sizes. It hence suggests that the sulfate be mainly affected by anthropogenic sources. If we consider the average mass ratio of P $M_{2.5}$ to TSP, the mass fractions of anthropogenic species to P $M_{2.5}$ , and the molar ratio of nss S $O_4$$^{2-}$ to total N $O_{3-}$, it may be possible to infer that a part of anthropogenic species measured at Tokchok Island be transported from China. The characteristics of neutralization of nss S $O_4$$^{2-}$ and the particle size of major ions are also discussed.