• Title/Summary/Keyword: Pilot zone

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Simulation of Natural Gas Injected Dual-Fuel DI 2-Stroke Diesel Engine (천연가스를 파이럿오일과 이원공급하는 직접분사식 2행정 디이젤기관의 시뮬레이션)

  • Choi, In Su
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.3
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    • pp.9-18
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    • 1995
  • The substitution of conventional fuel oil by alternative fuels is of immense interest due to liquid oil shortage and requirements of emission control standard. Among the alternative fuels, natural gas may be the most rational fuel, because of its widespread resource and clean est burning. Meanwhile, engine simulation is of great importance in engine development. Hence a zero-dimensional combustion model was developed for dual-fuel system. Natural gas was injected directly into the cylinder and small amount of distillate was used to provide the ignition kernel for natural gas burning. The intake air and exhaust gas flow was modeled by filling and emptying method. Although the single zone approach has an inherent limitation, the model showed promise as a predictive tool for engine performance. Its simulation was also made to see how the engine performance was influenced by the fuel injection timings and amount of each fuel.

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Effect of Acoustical Excitation and Flame Stabilizer on a Diffusion Flame Characteristics (음향가진과 보염기형상이 확산화염의 특성에 미치는 영향)

  • Jeon, C.H.;Chang, Y.J.
    • Journal of the Korean Society of Combustion
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    • v.3 no.1
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    • pp.1-10
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    • 1998
  • Lots of techniques are adopted for a flame stabilization and a high-load combustion. But the techniques being used were passive control method which have to change combustor shape like pilot flame, flame stabilizer, pressure profile, etc. Active control method which is not necessary to transform its shape is employed. Acoustical excitation is broadly used for its convenience in changing frequency and intensity. Both acoustical excitation and flame stabilizers were adopted to study their relationship. So, we investigated flammability limits. Flame visualization. And mean temperature in the condition of various frequencies, intensities, and flame stabilizers. As a consequence, flammability limit were advanced in acoustically excited flame at some frequencies. Coherent structure was extended to the downstream region through acoustical excitation and a size of vortice was curtailed. Also width of recirculation zone was magnified. In addition, Effects of acoustical excitation was stood out at 25mm flame stabilizer rather than another ones.

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The Attitude and Regulation of Chinese Arbitral Institution about an Emergency Arbitrator (긴급중재인 제도관련 중국 중재기관의 규정 및 태도)

  • Ha, Hyun-Soo
    • Journal of Arbitration Studies
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    • v.26 no.4
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    • pp.63-82
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    • 2016
  • In order to cope with the changes of International Commercial Arbitration, the Shanghai International Economic and Trade Arbitration Commission (SHIAC) regulated an Emergency Arbitrator for the first time, implementing the arbitration rules in China (Shanghai) Pilot Free Trade Zone on May 1, 2014. Moreover, the China International Economic and Trade Arbitration Commission (CIETAC) also regulated the Emergency Arbitrator in the revised arbitration rules on January 1, 2015. However, it caused considerable contradiction that SHIAC and CIETAC admitted an interim measure decision by the Emergency Arbitrator under the circumstance that the Chinese court can impose a preservative measure in the Civil Procedure Code (CPC) and Arbiration Act. This study attempted to compare the main contents of an Emergency Arbitrator regulated in the arbitration rules of SHIAC and CIETAC with arbitration rules of representative arbitral institutions which operate an Emergency Arbitrator. In addition, this study verified the application features and problems through comparing the rule of SHIAC and CIETAC with the rule related to the preservative measure in Chinese law.

1차원 현장 soil column 실험을 통한 SAT 반응 모델 검증

  • ;Jeongkon Kim
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.09a
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    • pp.83-86
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    • 2003
  • Soil Aquifer Treatment (SAT) is a technique in which secondary- or tertiary-treated wastewater is infiltrated through unsaturated soil and stored in the saturated zone. In SAT, contaminants are removed by physical and biochemical reactions taking place in soils. In this study, a numerical model was developed to predict changes in water quality during SAT operations. The contaminant species considered in the model were ammonium, nitrate, dissolved organic carbon, and dissolved oxygen. The model was calibrated against experimental data obtained from one dimensional soil column tests conducted for 84 days. The calibrated model will be used to find out optimum conditions for the pilot- and regional-scale SAT operations to be scheduled for the next phase of this project.

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Mixed Display Platform to Expand Comfortable Zone of Stereoscopic 3D Viewing

  • Yang, Ungyeon;Kim, Namkyu;Seo, Jinseok;Kim, Ki-Hong;Lee, Gil-Haeng
    • ETRI Journal
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    • v.35 no.2
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    • pp.352-355
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    • 2013
  • Common stereoscopic three-dimensional (3D) display has a convergence and accommodation conflict that violates the natural human cognitive process of viewing. This weakness exposes the challenge in supporting fun factors while eliminating safety problems in the 3D viewing experience. Thus, human factors have become a major research topic. In this letter, we propose a 3D stereoscopic visualization platform that can expand the sense of a 3D space by fusing organically mixed stereoscopic displays to provide a continuous feeling of 3D depth. In addition, we present pilot test results to show the possibility of the technical implementation of the proposed platform and note ongoing research issues to be addressed.

A Study on Flow Characterstics of Gas Turbine rvpe Combustor (II) - Flow Characteristics in Combustor - (가스터어빈형 연속류연소기의 유동에 관한 연구(II) -연소기내의 유동특성-)

  • 이근오;지용욱;김형섭
    • Journal of the Korean Society of Safety
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    • v.4 no.1
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    • pp.59-70
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    • 1989
  • This paper deals with the experimental study on the flow characteristics in straight flow can type combustor which has been used for high pressure ratio gas turbine combustor. The author has investigated the effects of swirl number and secondary air hole arrays in axial position on the flow characteristics by adopting the tuft method and 5-Hole Pilot Tube. From these experiments, as the swirl number increases, the results obtained is that the area of recirculation zone becomes wide and the position of vortex-core region approaches to the near of fuel nozzle in the model combustor. The most favourable penetration is obtained when secondary air jet is introduced through the air holes distributed in the form of paralled two rows in axial position of model combustor.

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Economic Prospects and Policies for Sustainable Agriculture in Korea (친환경농업의 경제성과 육성방안)

  • Oh Ho Sung
    • Proceedings of the Korean Society of Crop Science Conference
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    • 1998.10a
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    • pp.1-23
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    • 1998
  • Sustainable agriculture in Korea will gain important momentum by implementing The Direct Payment Scheme for Environmentally Friendly Agriculture in 1999. The farmers who want to participate in the program will be paid 530,000won/ha directly by the Government in return for engaging sustainable agriculture. The policy scheme which is a pilot program will be restricted to environmentally regulated areas to apply such as water supply protection zone, environmental protection districts and national parks. As a consequence of the policy, the supply of transitional organic agricultural products is expected to increase significantly. However the increased supply of low input agricultural products may have difficulties to find an appropriate marketing channel which is differentiated from the general agricultural product market. Development of an open market system for mass transaction of the low imput agricultural products is necessary. Also various government programs and projects which are designed for clean environment and regional community development must be integrated into the sustainable agriculture program to have synergy effects.

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An Experimental Study on the Characteristics of Temperature field according to the Combustor Diameters in the Dual Swirl Burner (이중 선회버너에서 연소실 직경에 따른 온도장 특성에 관한 실험적 연구)

  • Choi, Inchan;Lee, Keeman
    • 한국연소학회:학술대회논문집
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    • 2013.06a
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    • pp.107-108
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    • 2013
  • An experimental study in the dual swirl burner was conducted to analyze the temperature characteristics in the combustion field. The dual swirl burner consists of a main swirling pre-mixed flame with tangential swirler surrounding a pilot which can stabilize a diffusion flame or a partially premixed flame with vane swirler depending on whether fuel is supplied at the exit plane or further upstream. The purpose of this study is to analyse experimentally the characterization of flame temperature in the reacting zone, specially, according to the various combustor diameters like 80mm, 100mm, 130mm and 150mm(O.D). As a result, the temperatures of combustion field were decreased as the diameter of combustor increased. Therefore, these results can be expected that the larger diameter of combustor tend to emit less NOx emission than the small combustor.

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Emission studies of a dual swirl burner in the region of lean equivalence ratios (희박한 당량비 구간에서 이중 선회버너의 배출특성 연구)

  • Park, Taejoon;Lee, Keeman
    • 한국연소학회:학술대회논문집
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    • 2013.06a
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    • pp.111-112
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    • 2013
  • An experimental study of a dual swirl burner was conducted to analyze NOx emission in the lean conditions. The dual swirl burner is composed of a combination of swirling jet premixed(main section) and diffusion flames(pilot section). It was operated with a co-swirling configuration and overall equivalence ratios between 0.6 and 0.8. The purpose of this study is to analyze experimentally the characterization of flame temperature and NOx concentration in reacting zone and to supply the useful experimental data for numerical simulations. The measurements of temperature and NOx concentration were captured using a thin digitally-compensated thermocouple and a sampling quartz probe with quenching effect of sudden expansion, and were measured by the NOx analyzer of chemiluminescence method. We could analyse the NOx emission characteristics comparing the temperature distributions in the lean equivalence ratios.

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Evaluation of Bio-Chemical Restoration Index at the Creation Site of Ecological Environmental Zone in Coastal Area (연안생태환경공간 조성지의 생물-화학적 복원지수 평가)

  • Lee, In-Cheol;Yi, Byung Ho;Park, So Young;Ryu, Cheong Ro
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.28 no.1B
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    • pp.161-168
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    • 2008
  • The ecological environmental zones in coastal area, like tidal flat and salt marsh, were gradually decreased due to large scale of coastal development projects, reclamation and so on. Therefore, the development of artificial tidal flat and salt marsh has been emphasized in coastal area as mitigation concept and studies on related this background has performed. But studies on the quantitative evaluation for degree of restoration were insufficient. In this paper, as a fundamental study for evaluation of restoration on the creation of ecological environmental zones in coastal area, it was conducted that the monitoring and experiment for bio-chemical factors (bio-diversity, population and biomass of macro-benthos, survival ratio of reed, the number of heterotrophic bacteria and physico-chemical characteristics such as COD, IL, TN, TP and pH) using a in-situ pilot plant of tidal flat (Zone. P1) and salt marsh (Zone. P2), which was distinguished by content of dredged soil, in Jinudo, Nakdong estuary. From results of this study, the restoration index (RI), for evaluation concerning degree of restoration on the creation of ecological environmental zones in coastal area, was suggested and quantitative evaluation was performed using a restoration index (RI).