• Title/Summary/Keyword: Long Bar Impact

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Combination Effects of Large Dam and Weirs on Downstream Habitat Structure: Case Study in the Tamjin River Basin, Korea (대형 댐과 농업용 보가 하류 서식처 특성에 미치는 영향 연구: 탐진강 유역을 대상으로)

  • Ock, Giyoung;Kang, Ji-Hyun;Park, Hyung-Geun;Kang, Dong-Won
    • Korean Journal of Environmental Biology
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    • v.36 no.4
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    • pp.638-646
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    • 2018
  • The purpose of this study was to investigate the long-term habitat morphological alteration resulting from a large dam and weirs in the Tamjin River. To achieve this, we carried out a hydrograph analysis and a substrate size distribution analysis. We also estimated the channel width, bar area and vegetation encroachment using aerial photographs taken before and after the construction of the dam and weirs. The result of the hydrological analysis showed that flooding downstream was greatly reduced with small peaks occurrence after the dam construction. Interestingly, normal hydrographs in the main channel appeared just after tributary conjunction. There was a similar pattern in the substrate size analysis. Despite coarsened substrate just downstream of the dam site, more sand appeared again after introduction of the tributary. However, there was an increase in the bar area downstream of the dam's channels with most bars covered with vegetation. The channel width increased at the upper area of weirs through impoundment, but decreased downstream because of vegetation encroachment. This study indicate that unregulated tributary plays an important role in restoring hydro-physical habitat conditions in mainstream channels below a large dam. However, numerous weirs could be a causal factor to accelerate habitat deterioration in the dam downstream channels.

Impact of aggressive exposure conditions on sustainable durability, strength development and chloride diffusivity of high performance concrete

  • Al-Bahar, Suad;Husain, A.
    • Structural Monitoring and Maintenance
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    • v.2 no.1
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    • pp.35-48
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    • 2015
  • The main objective of this study is to evaluate the long-term performance of various concrete composites in natural marine environment prevailing in the Gulf region. Durability assessment studies of such nature are usually carried out under aggressive environments that constitute seawater, chloride and sulfate laden soils and wind, and groundwater conditions. These studies are very vital for sustainable development of marine and off shore reinforced concrete structures of industrial design such as petroleum installations. First round of testing and evaluation, which is presented in this paper, were performed by standard tests under laboratory conditions. Laboratory results presented in this paper will be corroborated with test outcome of ongoing three years field exposure conditions. The field study will include different parameters of investigation for high performance concrete including corrosion inhibitors, type of reinforcement, natural and industrial pozzolanic additives, water to cement ratio, water type, cover thickness, curing conditions, and concrete coatings. Like the laboratory specimens, samples in the field will be monitored for corrosion induced deterioration signs and for any signs of failureover initial period ofthree years. In this paper, laboratory results pertaining to microsilica (SF), ground granulated blast furnace slag (GGBS), epoxy coated rebars and calcium nitrite corrosion inhibitor are very conclusive. Results affirmed that the supplementary cementing materials such as GGBS and SF significantly impacted and enhanced concrete resistivity to chloride ions penetration and hence decrease the corrosion activities on steel bars protected by such concretes. As for epoxy coated rebars applications under high chloride laden conditions, results showed great concern to integrity of the epoxy coating layer on the bar and its stability. On the other hand corrosion inhibiting admixtures such as calcium nitrite proved to be more effective when used in combination with the pozzolanic additives such as GGBS and microsilica.

A study on the Korean Company's Overseas Expansion Strategy Through Japan Franchise Business Structure Analysis (일본 프랜차이즈사업 구조 분석을 통한 한국기업의 해외진출 전략에 관한 연구)

  • Cho, Hye-Duk;Lee, Sang-Youn
    • The Korean Journal of Franchise Management
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    • v.4 no.1
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    • pp.73-90
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    • 2013
  • Franchise industry know-how and an excellent management company organically integrated knowledge management resources industry. The franchise industry in the country's economic growth continues to contribute a large bar, has had an impact on the company's growth The franchise industry franchise industry in Japan than in other industries, and long-term steady growth rate despite the recent recession and recovery illustrates a trend Thus, the structure of the franchise industry in Japan by analyzing the company's franchise industry in Korea for overseas expansion strategies are evaluated In this study, a plateau in Japan to get bigger and provide a starting point for the 2009 and 2010 Census of Japan Association of Chain and Franchise all over the franchise system through a comparative analysis of Japanese overseas franchise business structure and strategies, and identify the research Korea based on the company's overseas expansion strategy is aimed at For this purpose, literature review and statistical analysis of the number of chain stores industry results, sales trends over the following four results are derived. 1) services with emphasis laid plans enable one franchise 2) the flow of services to the aging franchise, nursing, health-oriented, early childhood education, beauty and related business expected to grow 3) Recognition of Japanese culture and understanding of the importance of the service sector to account for differences in 4) services business of the need for efforts to increase productivity are summarized Based on the results of this study, Korea Franchise companies in the industry, Japan IS overseas expansion strategy franchise industry awareness of cultural differences in the institutional environment and the strategy should be considered.