• 한국입자에어로졸학회지
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• 제8권4호
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• pp.151-160
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• 2012

Health effects caused by the ultrafine particles in ambient air are great concern to the public health, and the strict measuring and monitoring of the ambient aerosol are required. In this work, the characteristics of the aerosol size distribution in Pohang province are studied. Optical particle counters (Grimm APS 1108 and 1109) were used to measure the aerosol size distribution in the area. Locations near the national monitoring site located in the industrial and the residence area were selected for the measuring sites of this study, and the locations in border area between the industry and the residence were selected for the reference of the comparison. In the industry site, it is found that the concentration of aerosol particles near the size of 5 ${\mu}m$ appear characteristically and the fluctuations in concentration with respect to time are minimal. The mass concentration of the aerosol above 10 ${\mu}m$ in diameter in the industry area was found to fluctuate significantly. The mass portion of $PM_{10}$ and PM2.5 to TSP in the residence area were 83% and 51% respectively. In the industrial regional, it was found that the mass portion of PM10 and $PM_{2.5}$ to TSP were 76% and 35% respectively. In the boundary area the mass portion of $PM_{10}$ and $PM_{2.5}$ to TSP were 78% and 54% respectively.

• Environmental Engineering Research
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• 제20권1호
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• pp.79-87
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• 2015

To treat leather industry wastewater (LIW) containing high nitrogen concentration, eight aerobic denitrifiers were isolated from sludge existing in an LIW-treatment aeration tank. Among them, one strain named as KH8 had showed the great ability in denitrification under an aerobic condition, and it was identified as Pseudomonas aeruginosa R12. The aerobic denitrification ability of the strain KH8 was almost comparable to its anaerobic denitrification ability. In lab-scale aerobic denitrifications performed in 1-L five-neck flasks for 48 hr, denitrification efficiency was found to be much improved as the strain KH8 held a great majority in the seeded cells. From the nitrogen balance at the cell-combination ratio of 10:1 (the strain KH8 to the other seven isolates) within the seeded cells, the percentage of nitrogen loss during the aerobic denitrification process was estimated to be 58.4, which was presumed to be converted to $N_2$ gas. When these seeded cells with lactose were applied to plant-scale aeration tank for 56 day to treat high-strength nitrogen in LIW, the removal efficiencies of $COD_{Cr}$ and TN were achieved to be 97.0% and 89.8%, respectively. Under this treatment, the final water quality of the effluent leaving the treatment plant was good enough to meet the water-quality standards. Consequently, the isolated aerobic denitrifiers could be suitable for the additional requirement of nitrogen removal in a limited aeration-tank capacity. To the best of our knowledge, this is the first report of aerobic denitrifiers applied to plant-scale LIW treatment.

• 한국환경보건학회지
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• 제46권6호
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• pp.757-763
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• 2020

Objectives: The objective of this study was to evaluate the concentrations of airborne fungi in public transportation from autumnl 2016 to summer 2017. Methods: This study measured the concentrations of airborne fungi on six subway lines and intercity buses in Seoul. Results: The concentration of fungi in the air in public transportation was found to be lower than the standard (500 CFU/㎥) for vulnerable group facilities among public use facities. In summer, the concentration of airborne fungi was relatively higher than in autumn. The concentrations of airborne fungi in subway (252.0 CFU/㎥) and train (45.1 CFU/㎥) were high tendency during non-rush hours in summer, while intercity bus was hightendency during rush hours in summer (111.9 CFU/㎥). The major types of airborne fungi in public transportation were Cladosporium, Penicillium, and Aspergillus. Conclusions: The harmful airborne fungus were detected though they did not exceed the standard in all public transportation. As a result, further studies on the analysis of the distribution of airborne fungi by ventilation and the characterization of indoor environments are needed to propose effective management of airborne fungi in public transportation.

• Laboraroty Animal Research
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• 제34권4호
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• pp.223-231
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• 2018

Regulation of gastrointestinal hormones have been reported in animal models for constipation undergoing laxative therapy when administered herbal products. We undertook to investigate whether the laxative activity of gallotannin-enriched extracts isolated from Galla Rhois (GEGR) affects the regulation of gastrointestinal hormones, by examining the concentration of four hormones and the activation of their receptors in the loperamide (Lop)-induced constipation model. Stool parameters, including number, weight and water content, were significantly recovered in the Lop+GEGR treated group, relative to the Lop+ vehicle treated group; however, food intake and water consumption were maintained at a constant level. Also, a similar recovery was detected for thickness of mucosa, muscle and flat luminal surface in the Lop+GEGR treated group. Furthermore, concentration of the four gastrointestinal hormones evaluated, namely, cholecystokinin (CCK), gastrin (GAS), somatostatin (SS) and motilin (MTL), were lower in the Lop+vehicle treated group than the No treated group, but were remarkably enhanced in the Lop+GEGR treated group. Moreover, the downstream signaling pathway of MTL and SS receptors were recovered after GEGR administration. Results of the present study therefore indicate that the laxative effects of GEGR treatment may be tightly related with the regulation of gastrointestinal hormones in the Lopinduced constipation model.

• 한국의류산업학회지
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• 제6권6호
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• pp.799-802
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• 2004

The dyeability of the cotton fabric with Brassica campestris extract was investigated. The colorant was extracted with methanol. Cotton fabrics were dyed at various conditions such as temperatures, concentrations, dyed times, and mordanting methods. The maximum wavelength of extract was 421nm. The highest K/S value was showed at 200% dye concentration at $60^{\circ}C$, 45 minutes. As the effect of dyed temperature and mordanting on dyeability was not great, the Brassica campestris was one-color dyestuff.

• Current Research on Agriculture and Life Sciences
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• 제33권2호
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• pp.57-63
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• 2015

안전한 천연물을 이용한 천연항산화제 개발 연구의 일환으로, 오크라, 엉컹퀴, 엄나무 및 줄풀 등 4종의 천연 약용식물 추출물의 항산화 활성을 측정해보았다. 추출물의 총 phenolic compounds 함량은 오크라와 엉컹퀴는 50% ethanol, 엄나무는 40% ethanol, 줄풀은 60% ethanol에서 최대용출을 나타내었으며, water 추출물에서 2.72~34.15 mg/g, ethanol 추출물에서 2.83~34.23 mg/g의 용출율을 나타내었다. 4종류 약용식물 water과 ethanol 추출물의 DPPH radical 소거능은 $50{\mu}g/mL$의 저농도에서 모두 74% 이상의 높은 소거활성을 나타내었다. ABTS radical cation decolorization을 측정한 결과, 4종의 약용식물 water 추출물과 ethanol 추출물 $100{\mu}g/mL$의 농도에서 모두 88% 이상의 높은 저해율을 나타내었다. 지용성 물질에 대한 항산화 효과를 측정하기 위해 antioxidant protection factor(PF)를 측정한 결과, 엉컹퀴 water과 ethanol 추출물 $50{\ddot{I}}g/mL$의 저 농도에서 각각 1.73과 1.76 PF로 다른 약용식물 보다 높은 항산화효과를 나타내었다. TBARs 생성 억제율을 측정한 결과 오크라를 제외한 3종의 약용식물 추출물 $50{\mu}g/mL$ phenolic 농도에서 80% 이상의 생성억제 효과를 나타내었다. 이러한 결과에 따라 다양한 약용식물 추출물이 항산화 및 기능성 식품 소재로 활용이 가능하다고 판단되었다.

• 한국엔터테인먼트산업학회논문지
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• 제14권6호
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• pp.109-124
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• 2020

이 연구는 한국 영화시장에서의 집중화 현상을 고찰하기 위해 스크린 규모와 흥행, 그리고 국적을 중심으로 이를 분석했다. 분석대상은 2005년부터 2019년까지 15년 동안의 연도별 흥행 100위권 영화로, 총 1,500편이다. 분석결과 스크린수는 매년 꾸준히 증가하는 추세였고, 스크린 집중화는 높은 수준으로 나타났다. 흥행 100위 기준 스크린 집중도는 2005년의 12%에서 30% 이상으로 상승했으며, 흥행 10위 기준에서는 2005년 21%에서 큰 상승폭을 보이며 2014년 이후 매년 50% 이상을 차지했다. 개봉 스크린 규모가 증가하면서 멀티플렉스는 흥행유인력이 높은 영화에 보다 많은 스크린을 할당했다. 오랫동안 스크린 독과점에 대한 비판이 있어왔지만 멀티플렉스는 2011년과 2012년 이후 이를 더 심화시키면서 한 편의 영화가 전체 스크린의 60% 이상을 차지하고 개봉되는 상황을 발생시키고 있다. 멀티플렉스의 이런 방식은 흥행 100위권 영화의 시장 점유율을 95%까지 상승하게 하고 있다. 또한 멀티플렉스는 한국영화보다 할리우드 영화에 보다 더 많은 스크린을 할당하는 경향을 보여주었다. 흥행성과가 높은 100위권을 대상으로 한 분석에서 영화 국적은 한국과 미국으로 집중된 것으로 나타났다. 이를 제외한 18개 국가의 경우 공급 측면에서 9.3%만 차지했다. 영화의 국적별 소비를 살펴보면, 두 국가로의 집중화 현상은 더 강하게 나타났다. 공급 차원에서 90.7%를 차지하고 있지만 소비 측면에서 96.6%를 차지했다. 공급에서의 집중화 현상은 소비에서의 집중화 현상과 정적인 상관관계를 보여주었고, 소비 측면에서의 집중화가 공급 측면보다 조금 더 높게 나타났다. 한국 영화시장은 스크린의 증가가 공급과 소비의 집중화를 심화한 사례로 드러났다.

• KIEAE Journal
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• 제17권3호
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• pp.125-131
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• 2017

Purpose: The study is to measure concentrations of indoor air pollutants in housing and to analyze the characteristics of pollutants in housing indoor-air between summer and winter comparatively. The research result could be used as data for public health through indoor air quality management of existing housing and more as a reference for new housing. Method: It was investigated 24 middle class housings of metropolitan area in winter which have been built for the past 30 years. Concentration of HCHO, TVOC was investigated in living room at morning and night and concentration of $CO_2$ was investigated in living room and master bedroom at morning and night. SKT100-X5 was used for concentration of HCHO, TVOC and ZGm053UK for concentration of $CO_2$. The characteristics of HCHO, TVOC, $CO_2$ concentration in winter were analyzed and then the concentrations in winter were analyzed the concentrations in summer being preceding research comparatively. Result: Average concentration of TVOC in winter was 2.7 times more than that of TVOC in summer, average concentration of HCHO in winter was about 2.0 times more than that of HCHO in summer. Average concentration of $CO_2$ in the morning at living room in winter was 1.3 times more than that of $CO_2$ in summer. Average concentration of $CO_2$ in the morning at master bedroom in winter was 1.1 times more than that of $CO_2$ in summer. Average concentration of TVOC was 1.31 times more than that of HCHO and standard deviation of that was 1.73 times higher. Average concentration of $CO_2$ was almost nearly close or over to 1,000ppm being criteria of the Ministry of Environment.

• Food Science and Biotechnology
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• 제15권2호
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• pp.196-201
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• 2006

Freeze concentration of milk was carried out thorough the controlled recrystallization of ice in a multi-stage freeze concentrator. Artificial temperature control was used to induce ice recrystallization via a heat and cold shock process. In each stage of freeze concentration, the recrystallization time was fixed at 1, 2, 4, and 8 hr to compare the solute concentrate, yield, Brix, ice crystal size, and freezing point at each experimental condition. Higher concentrations of milk solids were seen with increased durations of recrystallization time, and a maximum total solids in the final product of 32.7% was obtained with a ripening time of 8 hr in a second stage process. Milk solid yield decreased according to the solute concentration and recrystallization time. The results of Brix and ice crystal size showed a positive correlation with recrystallizaiton time. These results suggest the possibility of freeze concentration being of practical use in the dairy industry.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2018년도 공동국제학술발표회
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• pp.141-141
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• 2018