• Title/Summary/Keyword: GRI

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Analysis of Reduction Factors to Creep Deformation of Reinforced Geosynthetics

  • Jeon, Han-Yong;Yuu, Jung-Jo;Mok, Mun-Sung
    • Proceedings of the Korean Fiber Society Conference
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    • 2003.10a
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    • pp.104-104
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    • 2003
  • Geosynthetic Reinforcements - membrane drawn type, warp/knitted type, junction bonded type and composite type geogrids, strip type reinforcement - were used to compare the long-term perfor-mance by total factor of safety with reduction factors during service periods. To evaluate the reduction factors, wide-width tensile property, installation damage, creep deformation, chemical and biological degradation tests were performed. Long-term design strengths of geosynthetic reinforcements were calculated by using GRI standard Test Method GG4.

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Effect of hydrogen on adsorption of hydrocarbon fragments on graphene

  • Cho, Sangmo
    • Proceeding of EDISON Challenge
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    • 2014.03a
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    • pp.464-466
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    • 2014
  • We investigate the effect of hydrogen on adsorption of hydrocarbon molecules on graphene with density functional theory (DFT) calculations. In this study, we calculate the binding energies of hydrogen molecule, carbon atom and other hydrocarbon fragments such as CHx (x=1, 2, 3, 4) on graphene to find the most stable adsorption site. Then, to study the effect of hydrogen, we investigate the adsorption of hydrocarbon fragments in the presence of hydrogen atoms on graphene.

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Adsorption of carbon atoms on graphene/MgO(111)

  • Min, Kyung-Ah
    • Proceeding of EDISON Challenge
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    • 2013.04a
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    • pp.228-231
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    • 2013
  • In this study, we investigate the electronic and atomic structure of graphene on O-terminated MgO(111) using density functional theory (DFT) calculations. To suggest a possible direction for future band gap engineering of graphene on MgO(111), adsorption of carbon atoms on graphene/MgO(111) is studied by considering the several adsorption sites. Details in adsorption properties of carbon atoms on graphene/MgO(111) are analyzed in terms of energy band structure.

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A Chemical Reactor Modeling for Prediction of NO Formation of Methane-Air Lean Premixed Combustion in Jet Stirred Reactor (제트 혼합 반응기 내 희박 예혼합 메탄-공기 연소의 NO 생성 예측을 위한 화학 반응기 모델링)

  • Lee, Bo-Rahm;Park, Jung-Kyu;Lee, Do-Yong;Lee, Min-Chul;Park, Won-Shik
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.34 no.4
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    • pp.365-373
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    • 2010
  • A chemical reactor model (CRM) was developed for a jet stirred reactor (JSR) to predict the emission of exhaust such as NOx. In this study, a two-PSR model was chosen as the chemical reactor model for the JSR. The predictions of NO formation in lean premixed methane-air combustion in the JSR were carried out by using CHEMKIN and GRI 3.0 methane-air combustion mechanism which include the four NO formation mechanisms. The calculated results were compared with Rutar's experimental data for the validation of the model. The effects of important parameters on NO formation and the contributions of the four NO pathways were investigated. In the flame region, the major pathway is the prompt mechanism, and in the post flame region, the major pathway is the Zelodovich mechanism. Under the lean premixed condition, the N2O mechanism is the important pathway in both flame and postflame regions.

Analysis of Long-Term Deformation Behaviors of Geocomposites for Reinforcement (보강용 지오컴포지트의 장기변형거동 해석)

  • Jeon, Han Yong;Heo, Dai Young
    • Journal of the Korean Geosynthetics Society
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    • v.3 no.2
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    • pp.39-45
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    • 2004
  • Geocomposite mechanically bonded with woven type geotextile and nonwoven geotextile was used to examine to the long-term creep deformation behaviors by the SIM(Stepped Isothermal Method). The temperature steps were $26^{\circ}C$, $40^{\circ}C$, $54^{\circ}C$, $68^{\circ}C$, $82^{\circ}C$ and loading levels were 40%, 50%, 60% of designed strength for stepped isothermal method. Results of creep tests are showing that their strain were lower than 10% during 10,000 hours(GRI GS 10). Also, the effect of weft injection density to the creep deformation behaviors were examined. The weft densities of 0%, 50%, 100% of the original weft density showed the creep strain within 10% and the creep strain was increased with the decrease of weft injection density.

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A Study on Emission Characteristics of Inserting CO Tube (CO튜브 삽입에 따른 오염 물질 배출특성에 관한 연구)

  • Lee, Jae-Park;Kim, Jong-Min;Lee, Seung-Ro;Lee, Chang-Eon
    • Journal of Energy Engineering
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    • v.19 no.3
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    • pp.182-187
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    • 2010
  • This study was the effect of inserting CO tube on $NO_x$ and CO emission characteristics in a compact combustion chamber. In detail, $NO_x$ and CO emission characteristics with changing of distance due to inserting CO tube between a burner and a main heat exchanger were investigated. For this study, the commercial program, FLUENT with GRI 2.11 detail reaction mechanism, was used for the numerical study and a commercial heat exchanger was tested for the experimental study. As results, when the CO tube was inserted between a burner and a main heat exchanger, it was verified that $NO_x$ and CO emissions was decreased simultaneously as CO tube was closed to a burner and the distance between CO tube and a main heat exchanger was increased.

연구회 및 출연연구기관의 새로운 경영모형

  • 유성재;이정원
    • Proceedings of the Technology Innovation Conference
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    • 2003.02a
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    • pp.155-172
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    • 2003
  • Government Research Institutes(GRI), together with universities and private research labs, constitute the core of the Korea's national innovation system, The aim of this paper is to analyze the current system of GRIs and the National Research Councils(RC) in Korea, and suggest some policy recommendations conducive to achieving a world class competitive research system. To identify the problems and policy issues, we have conducted interviews (with executives staffs of RCs, GRIs and government ministries) and questionnaire surveys. For benchmarking purposes, we have visited 9 public research institutes in the USA, UK, Germany, and France. From the analysis of the problems revealed from the interviews and questionnaires, 6 policy variables are identified: three of them, which we call systemware variables, are governance structure, resources allocation system, and management control system; and the other three, which we call humanware variables, are visions and strategic goals, leadership, and research manpower, respectively. We have found that 1;he current GRI/RC systems are inefficient mainly due to the rigid and bureaucratic governance structure and inconsistent resource (i.e., government budgets) allocation systems. We reject the idea of replacing the current RC system with such radical alternatives as 're-governmentization'or 'privatization'. Instead we recommend that the government introduce a better system of governance and national budget allocations, which in turn would help induce a better management control systems, clear research visions and goals, strong leadership on the part of the RC chairman, and more creative and motivated researchers. These recommendations may provide opportunities and rooms for chairmen of RCs and presidents of GRIs to exercise more positive leadership in terms of fitting the visions and goal of GRIs to the national R&D strategy and creating a rational management control system as well as motivating researchers in GRIs to be more creative and productive.

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Effect of the CO Tube insert for Emission Characteristics in a Compact Combustion Chamber (컴팩트 연소실 내 CO튜브 삽입에 따른 오염물질 배출특성)

  • Lee, Jae-Park;Kim, Jong-Min;Lee, Seung-Ro;Jang, Gi-Hyun;Lee, Chang-Eon
    • Proceedings of the Korea Society for Energy Engineering kosee Conference
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    • 2010.04a
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    • pp.66-71
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    • 2010
  • This study was the effect of CO tube insert for NOx and CO emission characteristics in a compact combustion chamber. In detail, NOx and CO emission characteristics with changing of distance due to inserting the CO tube between the burner and the main heat exchanger were investigated. For this study, the commercial program, FLUENT, and the GRI 2.11 detail reaction mechanism were used for the numerical study and a simple model heat exchanger was tested for the experimental study. As results, when the CO tube was inserted between the burner and the main heat exchanger, it was verified the simultaneous NOx and CO reduction method because of increasing the residence time and decreasing the flame temperature.

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A Study on Meta Analysis of Preliminary Feasibility for Government R&D Programs to Improve Planning Project of the Government Funded Research Institutes (정부출연연구기관 주요사업 연구기획 강화를 위한 예비타당성조사 사업 메타분석연구)

  • Lee, Jong-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.11
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    • pp.445-453
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    • 2017
  • The Korean government's recent R&D policy has focused on encouraging government-funded research institutes (GRIs) to develop mid-term, long-term, and large-scale R&D projects. It is necessary to prepare thoroughly for the new R&D strategy, but there is no systematic accumulation of planning expertise, and there has been continued demand for good examples of research planning. Therefore, this study analyzes the reports of preliminary feasibility for government R&D programs through a meta-analysis of detailed evaluation items and contents to help researchers enhance their project-planning ability. The evaluation items that can be applied to R&D planning for GRI were reviewed, and twelve detailed evaluation items were selected through content analysis. The results of this study could contribute to practical R&D project planning and the improvement of evaluations.

Prediction of Pollutant Emissions from Lean Premixed Gas Turbine Combustor Using Chemical Reactor Network (화학반응기 네트워크을 이용한 희박 예혼합 가스터빈 연소기에서의 오염물질 예측에 관한 연구)

  • Park, Jung-Kyu;Nguyen, Truc Huu;Lee, Min-Chul;Chung, Jae-Wha
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.36 no.2
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    • pp.225-232
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    • 2012
  • A chemical reactor network (CRN) was developed for a lean premixed gas turbine combustor to predict the emission of pollutants such as NOx and CO. In this study, the predictions of NOx and CO emissions from lean premixed methane-air combustion in the gas turbine were carried out using CHEMKIN and a GRI 3.0 methane-air combustion mechanism, which includes the four NO formation mechanisms for various load conditions. The calculated results were compared with experimental data obtained from a modified test combustor to validate the model. The contributions of the four NO pathways were investigated for various load conditions. The effects of nonuniformity of the mass flux and of the equivalence ratio of the injector on the NOx formation were investigated, and a method of reducing the pollutant formation was suggested for the development of a sub-10 ppm gas turbine combustor.