• Title/Summary/Keyword: Air-quality

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Removal/Recovery of VOCs Using a Rubbery Polymeric Membrane (Rubbery 고분가 막을 이용한 휘발성 유기화학물의 제거 및 회수)

  • Cha, Jun-Seok
    • Membrane Journal
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    • v.6 no.3
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    • pp.173-181
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    • 1996
  • Common volatile organic compounds(VOCs) such as toluene and methanol were removed successfully from N$_{2}$ using a novel silicone-coated hollow fiber membrane module. This novel membrane is a thin film composite(TFC) and was highly efficient in removing VOCs selectively from a N$_{2}$ stream. This membrane had some innate advantages over other silicone-based membrane in that the selective barrier was ultrathin(~1 $\mu$m) and the porosity of the polypropylene substrate was high which leads to a low permeation resistance. The substram was very strongly bonded to the coating layer by plasma polymerization and can withstand a very high pressure. A small hollow fiber module having a length of 25cm and 50 fibers could remove 96~99% of toluene as well as methanol vapors when the feed flow rate was up to 60cc/min. The percent removal of VOCs were even higher when the feed inlet concentration was higher. This process is especially suitable for treating streams having a low flow rate and high VOCs concentration. The permeances of VOCs through this membrane was in the range of $4~30 \times 10^{-9}gmol/sec \cdot cm^{2}\cdot cmHg$ for both toluene and methanol, and nitrogen permeance was between $3~9 \times 10^{-10}gmol/sec \cdot cm^{2} \cdot cmHg$. High separation factor between 10~55 for toluene/N$_{2}$ and 15~125 for methanol/N$_{2}$ were obtained depending on the feed flow rate ranges and feed VOCs concentration levels.

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Effect of High-Humidity and High Temperature at Kentucky Bluegrass Growth in Summer (하절기 한지형 잔디 재배 시 침수 및 고온으로 인한 잔디의 생육 불량 현상)

  • Lee, Jeong-Ho;Choi, Jun-Yong;Lee, Song-Ho;Joo, Young-Kyoo
    • Asian Journal of Turfgrass Science
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    • v.22 no.2
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    • pp.133-140
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    • 2008
  • The growth of root and shoot normally decline dramatically in mid-summer of Korea, moreover the cool-season turfgrassgrass eventually wither to death over $30^{\circ}C$. The increase of air temperature also drives the heat of soil, that makes stress on root system. The heat stress affects physiological mechanisms of hormonal unbalance that stimulates shoot growth, photosynthesis, and transpiration. To solve those problems, many studies have been carried out to control soil moisture and OM content to decrease soil temperature for dissolving the growth retardant by heat stress. This study initiated to analyze the change of soil temperature with soil moisture, and the effect of soil depth and moisture content on heat transmit and thermal changes on turfgrass growth(productivity, green color, and damage by dryness and high temperature). Kentucky bluegrass plots prepared with 25%, 33%, 40% soil moisture treatments. Soil temperature was measured every five min. with four thermo-sensors at 12 and 2 cm soil depth. The most acceptable growth showed at 33% soil moisture, but the worst result showed at 40%. The soil moisture seriously affected on the growth of Kentucky bluegrass, however the quality of turfgrass may acceptable if we can control soil moisture down to 33% when the flooding season of monsoon.

Fixation and Histochemistry of Biological Tissues Using the Microwave Fixator Equipped with Infrared-Temperature Sensor (적외선 온도감응기를 장착한 마이크로파 고정기에 의한 생체조직 고정효과와 조직화학적 특성)

  • 신길상;민소연;김완종;손태호
    • The Korean Journal of Zoology
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    • v.38 no.3
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    • pp.417-425
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    • 1995
  • The present study was carried out to investigate the effect of microwave fixation in comparison with that of chemical fixation in preparing the microscopic samples. The microwave fixator was equipped with infrared-temperature sensor, and that was designed to compensate air temperature in the microwave fixator. In the microwave fixation, rat tongue was well preserved in terms of muscular fasciculus and pancreas stained by Feulgen reagents showed clear reaction products in the nucleus. Reaction products by PAS method in duodenal villi appeared specifically at the goblet cells. In electron microscopy, pancreatic cellular components such as secretory granules and collagen bundles were well preserved in both fixations. In aspect of histochemical reaction and electron microscopy, high quality was due to the protein content of microwave fixed specimen. The microwave fixation method saved total duration engaging microscopic preparation.

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Effect of Variety and Shading Material on Growth Characteristics and Ginsenoside Contents of 2-Year-Old Ginseng (Panax ginseng C. A. Meyer) Grown in Imperfectly Drained Paddy Soil (배수약간불량 논토양에서 품종 및 해가림 피복물 종류가 2년생 인삼의 생육과 진세노사이드 함량에 미치는 영향)

  • Lee, Sung-Woo;Yeon, Byeong-Yeol;Kim, Chung-Guk;Shin, Yoo-Su;Hyun, Dong-Yun;Kang, Seung-Won;Cha, Seon-Woo
    • Korean Journal of Medicinal Crop Science
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    • v.16 no.6
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    • pp.434-438
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    • 2008
  • To selection of optimal shading material, two-year-old ginseng (Panax ginseng C. A. Meyer) of new cultivar, 'Cheonpoong' (CP), and native species 'Hwangsookjong' (HS) were cultured under three kinds of shading materials such as three-layered blue and a one-layered black PE (polyethylene) net (TBSB), blue PE sheet (BS), and aluminium coated PE sheet (AS) in imperfectly drained paddy soil. Growth characteristics, yield and ginsenoside contents were investigated under three shading materials. Yield and ginsenoside contents of ginseng were distinctly affected by intensity and quality of sunlight penetrated through shading materials. Light transmission ratio, air and soil temperature according to shading materials were higher in order of BS, AS, and TBSB. However, ratio of aerial phase and porosity of the soil were higher in order of AS, BS, and TBSB, respectively. There was no significantly difference in the ratio of rusty colored root by shading materials. CP showed higher stem length, leaf area, and root weight than that of HS, while the former showed distinctly lower discolored leaf ratio than that the other. Eight kinds of ginsenosides content of CP were higher than that of HS in $Rg_1$, Re, Rf, $Rb_1$ and Rc except $Rg_2$, $Rb_2$, and $Rb_3$. Total ginsenoside contents of CP was distinctly higher than that of HS. Total ginsenoside contents as affected by shading materials was higher in order of BS, TBSB, and AS in CP, while TBSB, BS, and AS in HS.

Characteristics of Stormwater Runoff with respect to Pavement Types (도로 포장방법에 따른 비점오염물질 유출특성 비교)

  • Kim, Cheolmin;Choi, Jiyeon;Lee, Jung Min;Cho, Hyejin;Kim, Lee-Hyung
    • Journal of Wetlands Research
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    • v.16 no.3
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    • pp.423-429
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    • 2014
  • Due to high imperviousness rates of the roads, various pollutants originated from vehicle activities and air depositions are accumulated on the road surfaces. The washed-off pollutants can deteriorate the water quality and destroy the aqua-ecosystems with their toxicity. Usually the roads are paved with asphalt and concrete, which can affect on the pollutant concentrations with different frictional forces. Therefore, this research is performed to evaluate the influences of different pavement type on discharged concentrations of pollutant. The results shows the first flush phenomenon was occurred on both pavement types. However, peak concentrations are higher in concrete pavement areas than asphalt pavement because concrete pavement has high contact area with vehicles. The EMCs(Event Mean Concentration) also shows high values in concrete paved roads. As a result of this research, it can be concluded the pavement type is also one of the important affecting factors on pollutant emissions from the roads.

A Study on the Preparation of Boogags by Traditional Methods and Improvement of Preservation (전통적 방법에 의한 부각의 제조 및 저장성 향상에 관한 연구)

  • 박재익;정계환;김봉섭;허종화
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.23 no.6
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    • pp.986-993
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    • 1994
  • As a part of development of traditional foods, mugwort boogag and dry laver boogag were fried insoybean oil, and BHA or tocopherol-added soybean oil. They were wrapped up in opp vinyl film, and preserved at $4^{\circ}C(RH{\;}40{\pm}5%){\;}and{\;}25^{\circ}C(RH{\;}80{\pm}5%)$. During the storage of bobogags, acid value, peroxide value, and TBA value were investigated. Changes of sensory evaluation and texture profile were also examined. Boogags were manufactured by washing the raw materials. drying in the shade, mixing them with glutinous rice flour, and hot-air drying up it to 13 % of moisture contents after dryed it up to 80% of moisture contents on dry table for 23days, in order. These boogags were packaged to manufacture goods with dryed state or fried at $160^{\circ}C$ for 10 sec. Acid value, peroxide value, and TBA value of boogags which preserved at $4^{\circ}C$ generally appeared lower than at $25^{\circ}C$. As storage time goes by, moisture contents of bobogagas preserved at $25^{\circ}C$ increased and its quality were gradually deteriorated. When the boogags were fried in BHA(0.01%) and tocopherol (0.01%) added soybean oil, changes of acid value, peroxide value, TBA value were generally low. During the storage of bobogagas antioxidant effect of BHA was higher than that of tocopherol. Texture was inclined to decrease as storage time goes, by that of boogags preserved at $4^{\circ}C$ was a little more satisfactory. Hardness was also high.

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Mass transfer Characteristic during Osmotic Dehydration of Ginger and Its Effect on Quality (생강 삼투압 건조 시 물질이동 특성과 품질에 미치는 효과)

  • Kim, Myung-Hwan
    • Applied Biological Chemistry
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    • v.41 no.5
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    • pp.372-376
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    • 1998
  • Internal mass transfer during osmotic dehydration of gingers in sugar solution was examined as a function of concentration, temperature and immersion time of those solutions using moisture loss, sugar gain, molality and rate parameter. Influence of osmotic dehydration on browning reaction and texture properties of air dried rehydrated was also evaluated. Increasing the concentration and temperature of sugar solutions increased moisture loss, sugar gain, molality and rate parameter. Water loss and sugar gain were rapid in the first 3 min and then changed gentle slope. Moisture loss during osmotic dehydration using a sugar solution $(60\;Brix,\;80^{\circ}C)$ with 18 min immersion time was 40.05 g moisture/100 g wet ginger which was 52% reduction of initial moisture content in ginger (83.02%, wet basis). The changes of rate parameter were more affected by temperature than by concentration of sugar solution. Minimum browning degree (O.D.=0.027) was carried out by osmotic dehydration in sugar solution $(40\;or\;50\;Brix,\;80^{\circ}C)$ with 15 min immersion time compared to control (O.D.=0.132). Influence of osmotic dehydration on puncture forces of 3 min rehydrated ginger in boiling water were $22{\sim}34%$ of reduction, while blanching treatment had not affected compared to those of control.

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Distribution of Microorganisms in Domestic Museum Environments (국내 박물과 환경에 분포하는 미생물의 분리)

  • Lee Sang-Joon;Lee Jae-Dong;Cha Mi-Sun;Lee Na-Eun;Yoon Soo-Jeong;Cho Hyun-Hok;Kwon Young-Suk
    • Journal of Environmental Science International
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    • v.14 no.8
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    • pp.793-800
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    • 2005
  • We isolated and identified microorganisms from the aerial environment of domestic museums. The fungi, Penicillium spp., Alternaria spp., and Cladosporium spp. were isolated in many museums. It seems that these fungi are related to biological degradation of textile remains. A total of 14 kinds of bacterial strains were isolated: Acinetobacter spp., Pseudomonas spp., Neisseria spp., Alcaligenes spp., Shigella spp., Klebsiella spp., Corynebacterium spp., Aerococcus spp., Bacillus spp., Micrococcus spp., Citrobacter spp., Erwinia spp., Salmonella spp., and Providencia spp. Acinetobacter spp., Pseudomonas spp., Neisseria spp., and Alcaligenes spp. were the predominate bacteria found in samples with a variety of bacteria. This suggests that there is a relationship between bacteria and the damage of textile remains. In the museum, we isolated Alternaria spp, Geotrichum spp., Penicillium spp. Acinetobacter spp., Pseudomonas spp., Alcaligenes spp. from the entrance, exhibit hall and storage, but they were found in smaller number and species in the exhibit cases and paulownia cases. We concluded that paulownia cases were not influenced by the microorganisms because of quality of care provided by the museum staff. Corynebacterium spp., and Bacillus spp. were not detected at the entrance and exhibit hall but were detected in paulownia cases. It is presumed that those bacteria did not flow in from outside, but resulted from contaminants in paulownia cases. In the distribution of microorganisms associated with textile remains, more fungi were detected than bacteria. Acinetobacter spp., Pseudomonas spp., and Neisseria spp., were isolated from silk items. Penicillium spp. and Cladosporium spp. were isolated in the silk and hump items. Aspergillus spp. and Penicillium spp. were isolated from the cotton items. On the other hands, there were no fungi strains in the wool items. Most of the isolated strains from textile remains were aerial microorganisms from the museum environment. These results suggest that textile remains were apt to contaminated by contact with the air.

A Study of population Initialization Method to improve a Genetic Algorithm on the Weapon Target Allocation problem (무기할당문제에서 유전자 알고리즘의 성능을 개선하기 위한 population 초기화 방법에 관한 연구)

  • Hong, Sung-Sam;Han, Myung-Mook;Choi, Hyuk-Jin;Mun, Chang-Min
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.5
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    • pp.540-548
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    • 2012
  • The Weapon Target Allocation(WTA) problem is the NP-Complete problem. The WTA problem is that the threatful air targets are assigned by weapon of allies for killing the targets. A good solution of NP-complete problem is heuristic algorithms. Genetic algorithms are commonly used heuristic for global optimization, and it is good solution on the diverse problem domain. But there has been very little research done on the generation of their initial population. The initialization of population is one of the GA step, and it decide to initial value of individuals. In this paper, we propose to the population initialization method to improve a Genetic Algorithm. When it initializes population, the proposed algorithm reflects the characteristics of the WTA problem domain, and inherits the dominant gene. In addition, the search space widely spread in the problem space to find efficiently the good quality solution. In this paper, the proposed algorithm to verify performance examine that an analysis of various properties and the experimental results by analyzing the performance compare to other algorithms. The proposed algorithm compared to the other initialization methods and a general genetic algorithm. As a result, the proposed algorithm showed better performance in WTA problem than the other algorithms. In particular, the proposed algorithm is a good way to apply to the variety of situation WTA problem domain, because the proposed algorithm can be applied flexibly to WTA problem by the adjustment of RMI.

A Study on Smart Factory System Design for Screw Machining Management (나사 가공 관리를 위한 스마트팩토리 시스템 설계에 관한 연구)

  • Lee, Eun-Kyu;Kim, Dong-Wan;Lee, Sang-Wan;Kim, Jae-joong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2018.10a
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    • pp.329-331
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    • 2018
  • In this paper, we propose a monitoring system that starts with the supply of raw materials for threading, is processed into a lathe machine, and checks for defects of the product are automatically performed by the robot with Smart Factory technology through assembly and disassembly. Completion check according to the production instruction quantity and production instruction is made by checking the production status according to whether or not the raw material is worn by the displacement sensor, and checking the pitch and the contour of the processed female and male to determine OK and NG. The robotic system acts as a relay for loading and unloading of raw materials, pallet transfer, and overall process, and it acts as an intermediary for organically driving. The location information of the threaded products is collected by using the non-contact wireless tag and the energy saving system Production efficiency and utilization rate were checked. The environmental sensor collects the air-conditioning environment data (temperature, humidity), measures the temperature and humidity accurately, and checks the quality of product processing. It monitors and monitors the driving hazard level environment (overheating, humidity) of the product. Controls for CNC and robot module PLC as a heterogeneous system.

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