• Title/Summary/Keyword: Water types

검색결과 4,269건 처리시간 0.034초

기수호의 습성천이 현상과 생태적 복원정책 (On the Realities of Hydrach Succession in Brackish Water Lakes and Ecological Restoration Policy)

  • 신승춘;박용길
    • 한국환경과학회지
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    • 제13권1호
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    • pp.11-17
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    • 2004
  • The purpose of this study is to present the model of ecological restoration through analysis on the condition of hydrach succession process in brackish water lake. To this study, we investigate and research the present condition of brackish water lake in South Korea. Most brackish water lake in South Korea have characteristics that is come into being malignant hydrach succession. Many lakes were reclaimed to increase foodstuff production. And river conservation work seperate lakes from the ocean. In a embryological view, most lakes based on the brackish water lakes, But present lakes show many different types such as a fresh water lake, a salt lake, a brackish water lake, a swamp, and a marshland. As a result, brackish water lakes have greatly damaged by diverse artificial interventions to promote people's activities. Therefore, in order to manage brackish water lakes systematically, criteria of lake preservation must be coincide with the present conditions of hydrach succession in each lake.

Behavior of Water Vapor Permeability on Layered System

  • Oh, Ae-Gyeong
    • 한국의류산업학회지
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    • 제11권2호
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    • pp.359-362
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    • 2009
  • This study investigates the behavior of water vapor permeability of a layered system to find out a comfortable combination of a layered system for outdoor activities and examines the water vapor permeability of various types of outdoor clothing fabrics. The layered system includes the base layer such as sportswool and polyester/cotton fabrics, the middle layer such as single and double sided fleece fabrics, and the shell layer such as polyurethane-coated, PTFE-laminated and microfiber fabrics in this experiment. Results show that the layered system was applied, it was working together as a whole having some influence on each other layer, though every layer offered varying degree of water vapor permeability. Water vapor permeability of layered system exactly followed the same trend as the shell layer, which is all vapor permeable water repellent fabrics as a single layer. The rate of water vapor transfer through a layered system is mainly related to the type of vapor permeable water repellent fabrics used for the shell layer.

Characteristics of Wintering Bird Communities in the Moeyungyi Wetland Wildlife Sanctuary, Myanmar

  • Aung, Hsu Sandar;Kim, Hankyu;Lee, Yohan
    • Journal of Forest and Environmental Science
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    • 제38권3호
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    • pp.195-206
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    • 2022
  • Gaining an understanding of bird communities in different habitat types is essential for the conservation of ecologically important habitats. Wetlands possess different types of habitats and provide an important environment for wintering waterbird communities. This study compares avian communities in five different habitat types in the Moeyungyi Wetland Wildlife Sanctuary (MWWS), Myanmar. From December 2014 to the first week of February in 2015, bird and habitat data were collected from representative areas of five habitat types (i.e., short grassland, tall grassland, lotus fields, open water areas, and rice fields) at MWWS. We established nine sampling plots in each habitat type, and used the point quadrat method to survey habitats and the point count method to survey birds in the habitats. Simple one-way analysis of variance (ANOVA) and post-hoc tests were used to determine differences between bird communities. We made 95 detections during 19 daily visits to each of the five habitat types. During the survey period, we recorded a total of 10,389 individuals belonging to 52 different bird species, based on 7-min observations at each of the 45 point count stations. Furthermore, we detected significant differences by habitat structure (i.e., vegetation coverage, height, and density; water depth; and plant species diversity) as well as bird communities (i.e., species richness, abundance, and diversity indices). In addition, the detailed analysis of 52 avian species revealed significant differences among 45 species with respect to the mean numbers of observed individuals in the survey habitats. The findings of this study revealed significant differences in the structure and composition of waterbird communities among the five assessed habitat types. Because natural marshes provide preferable habitats for a larger number and greater diversity of birds, relative to rice fields, natural marshes should be prioritized for conservation and restoration in Moeyungyi Wetland Wildlife Sanctuary.

석탄계 활성탄별 흡착능 및 경제성 평가 (Adsorption Efficiency of Coal Based GACs and Evaluation of Economic Efficiency)

  • 최동훈;손희종;박진식;문추연;류동춘;장성호;권기원;김한수
    • 한국환경과학회지
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    • 제22권2호
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    • pp.205-213
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    • 2013
  • This is made of domestic and foreign coal activated carbon of five species, physicochemical adsorption efficient about sterilize products and micro harmful substances and is a result of the economic evaluation. The most well-developed micropores bed volume 123,409 of AC-1 activate carbon appeared to be the best next AC-2, AC-3, AC-4, AC-5 followed by activated carbon was investigated. PFOA and PFOS in the BV 96,000 when evaluating foreign types of adsorption activated carbon adsorption capacity was greater when more than PFOA, PFOS showed that the adsorption well. The economic evaluation of activated carbon usage in chloroform (CUR) was most excellent as a AC-1 4.3 g/day, the next AC-2, AC-3, AC-4, AC-5 there are two types of foreign economic order appears to have appeared, but the current domestic market when applying the price AC-1, AC-3, AC-2, AC-4, AC-5 order was investigated.

강황(薑黃) 추출물의 암세포 성장 억제 효과 (Curcuma Longa L. Extract Controls Cancer Cell (Sarcoma 180) Growth)

  • 조수인
    • 대한본초학회지
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    • 제20권4호
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    • pp.27-31
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    • 2005
  • Objectives : The anticancer response of three different types of water extracts of Zingiberaceae Curcuma longa L. tested for sarcoma 180. Only few studies carried out to investigate the effects of other contents of Curcuma longa L. in anticancer activities, therefore, in this study we have investigated the effects of other component then curcumin in Curcuma longa L. for anticancer a activities. Methods : Three different types of water extracts of Curcuma longa L. were prepared as follows. The sarcoma cells (S180) were maintained in Dulbecco's modified Eagle's medium (DMEM) and were seeded on 24-well cell culture cluster flat bottom with lid tissue culture treated non-pyrogenic polystyrene. The growth of sarcoma 180 was monitored for 1, 2 and 5 days. The sarcoma cells were pictured using inverted microscope and cell density was counted using hemocytometry. Results : After 5 days in the culture medium the results showed high growth of sarcoma 180 for control condition and the surface of CCP plates were fully covered with the cells. In case of medium in which the 10% of filtered water extract of Curcuma longa L. was added a very limited growth of sarcoma 180 was observed. The results were showed only small difference in cell density for two different concentrations of unfiltered water extracts of Curcuma longa L. whereasin case of filtered water extracts the control of sarcoma growth shows better result. Conclusion : The filtered water extracts showed the best result relatively to the unfiltered water extracts for two different concentrations. This indicates that the water extracts of Curcuma longa L. can have anticancer activities possibly without curcumin.

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토성 및 지하수위에 따른 사료용 옥수수와 수수-수단그라스 잡종의 생육 (Growth of Maize and Sorghum-Sudangrass Hybrid Affected by Soil Texture and Ground Water Levels)

  • 이호진;김수형;이홍석
    • 한국작물학회지
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    • 제39권6호
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    • pp.585-593
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    • 1994
  • 사양토와 식양토 두 토성에 대하여 각각 25, 35, 50, 70, 100cm의 지하수위가 조절가능한 시험구에서 토성 및 지하수위가 우리나라에서 주로 이용되는 두가지 청예사료작물인 옥수수와 수수-수단그라스 잡종의 생육에 미치는 영향을 알아보고 작물별 적정지하수위를 알아보기 위하여 1993년에 수행되었다. 그 결과를 요약하면 다음과 같다 1. 두 작물 모두 사양토에서 우수한 생육을 보였으며 옥수수는 사양토의 지하수위 100cm에서 가장 우수한 생육을 보였으며 수수-수단그라스 잡종은 사양토 지하수위 70cm에서 가장 우수한 성적을 나타내었다. 2. 수수-수단그라스 잡종이 토성차이 및 지하수위 차이에 따른 생육의 변이가 적어서 옥수수에 비해 적응성이 높은 것으로 판단되었다. 3. 옥수수와 수수-수단그라스 잡종의 뿌리 해부구조 관찰결과 토성 및 지하수위에 따른 일정한 경향을 찾아내기는 어려웠으며 옥수수에서 피층조직이 파괴된 경우가 더 많았고 부위별로는 중간부분과 끝부분에서 피층조직이 파괴된 경우가 더 많았다.

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Arsenic Removal from Water Using Various Adsorbents: Magnetic Ion Exchange Resins, Hydrous Ion Oxide Particles, Granular Ferric Hydroxide, Activated Alumina, Sulfur Modified Iron, and Iron Oxide-Coated Microsand

  • Sinha, Shahnawaz;Amy, Gary;Yoon, Yeo-Min;Her, Nam-Guk
    • Environmental Engineering Research
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    • 제16권3호
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    • pp.165-173
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    • 2011
  • The equilibrium and kinetic adsorption of arsenic on six different adsorbents were investigated with one synthetic and four natural types (two surface and two ground) of water. The adsorbents tested included magnetic ion exchange resins (MIEX), hydrous ion oxide particles (HIOPs), granular ferric hydroxide (GFH), activated alumina (AA), sulfur modified iron (SMI), and iron oxide-coated microsand (IOC-M), which have different physicochemical properties (shape, charge, surface area, size, and metal content). The results showed that adsorption equilibriums were achieved within a contact period of 20 min. The optimal doses of adsorbents determined for a given equilibrium concentration of $C_{eq}=10\;{\mu}g/L$ were 500 mg/L for AA and GFH, 520-1,300 mg/L for MIEX, 1,200 mg/L for HIOPs, 2,500 mg/L for SMI, and 7,500 mg/L for IOC-M at a contact time of 60 min. At these optimal doses, the rate constants of the adsorbents were 3.9, 2.6, 2.5, 1.9, 1.8, and 1.6 1/hr for HIOPs, AA, GFH, MIEX, SMI, and IOC-M, respectively. The presence of silicate significantly reduced the arsenic removal efficiency of HIOPs, AA, and GFH, presumably due to the decrease in chemical binding affinity of arsenic in the presence of silicate. Additional experiments with natural types of water showed that, with the exception of IOC-M, the adsorbents had lower adsorption capacities in ground water than with surface and deionized water, in which the adsorption capacities decreased by approximately 60-95%.

The Occupational Exposure Limit for Fluid Aerosol Generated in Metalworking Operations: Limitations and Recommendations

  • Park, Dong-Uk
    • Safety and Health at Work
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    • 제3권1호
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    • pp.1-10
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    • 2012
  • The aim of this review was to assess current knowledge related to the occupational exposure limit (OEL) for fluid aerosols including either mineral or chemical oil that are generated in metalworking operations, and to discuss whether their OEL can be appropriately used to prevent several health risks that may vary among metalworking fluid (MWF) types. The OEL (time-weighted average; 5 mg/$m^3$, short-term exposure limit ; 15 mg/$m^3$) has been applied to MWF aerosols without consideration of different fluid aerosol-size fractions. The OEL, is also based on the assumption that there are no significant differences in risk among fluid types, which may be contentious. Particularly, the health risks from exposure to water-soluble fluids may not have been sufficiently considered. Although adoption of The National Institute for Occupational Safety and Health's recommended exposure limit for MWF aerosol (0.5 mg/$m^3$ ) would be an effective step towards minimizing and evaluating the upper respiratory irritation that may be caused by neat or diluted MWF, this would fail to address the hazards (e.g., asthma and hypersensitivity pneumonitis) caused by microbial contaminants generated only by the use of water-soluble fluids. The absence of an OEL for the water-soluble fluids used in approximately 80-90 % of all applicants may result in limitations of the protection from health risks caused by exposure to those fluids.

국소마취제(局所麻醉劑)가 Sulfanilamide의 직장내(直腸內) 흡수(吸收)에 미치는 영향 (The Influence of the Local Anesthetics on the Absorption of Sulfanilamide through the Rectum)

  • 하춘자;이진환;최준식
    • 대한약리학회지
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    • 제9권1호
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    • pp.53-58
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    • 1973
  • Author attempts to determine the absorption of the sulfanilamide by the various suppositorial bases contained the local anesthetics through the rectum of the rabbit. The types of bases examined are four of lipophillic, hydrophillic and emulsion types such as oil in water and water in oil, otherwise the local anesthetics are procaine and lidocaine each other 2 and 20 percent in a suppository. The results are as follows; 1. The absorption of sulfanilamide is higher when they are combined with the local anesthetics than when single drugs of them are used. 2. The promotion of absorption by the local anesthetics, both the procaine and lidocaine, are higher when they are used 20 percent than 2 percent as the concentration. 3. In excellency of the suppositorial base, the order of the blood level is polyethylene glycol, oil in water, water in oil as emulson type and cacao butter.

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