• 제목/요약/키워드: Natural supply

검색결과 891건 처리시간 0.026초

CFD Approach on Gas Explosion for SIL in Gas Fuelled Ship

  • Kim, Ki-Pyoung;Kim, You-Taek;Kang, Ho-Keun
    • Journal of Advanced Marine Engineering and Technology
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    • 제39권2호
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    • pp.195-200
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    • 2015
  • It is envisaged that the effect of increasingly stricter air emissions legislation implemented through IMO Annex VI and other local air quality controls, together with favorable financial conditions for the use of natural gas instead of liquid fuel oil as a bunker fuel, will see an increasing number of DF engine and single gas fuel engine applications to LNG carriers and other vessel types. As part of provision for the current international movements in the shipping industry to reduce GHG emission in air, new design concepts using natural gas as an alternative fuel source for propulsion of large commercial vessels, have been developed by shipyards and research institutes. In this study, an explosion analysis for a gas supply machinery room of LNG-fuelled container ship is presented. The gas fuel concept is employed for the high pressure ME-GI where a leakage in the natural gas double supply pipe to the engines is the subject of the present analysis. The consequences of a leak are simulated with computational fluid dynamics (CFD) tools to predict typical leak scenarios, gas cloud sizes and possible explosion pressures. In addition, capacity of the structure which is subject to explosion loads has been assessed.

천연가스 기관의 성능 향상에 관한 연구 (A study on performance improvement of natural gas fueled engine)

  • 정동수;정진도;서승우;최교남
    • 대한기계학회논문집
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    • 제16권1호
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    • pp.175-179
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    • 1992
  • 본 연구에서는 LPG 기관을 천연가스 이용기관으로 변경하고자 할 때 발생하는 출력 감소를 보안하기 우하여, 공기연료 혼합비 조절, 점화시기조절, 과급효과 방법에 의한 출력향상 효과를 파악하였다.

델파이법을 이용한 천연염색에 관한 기초 연구 (제3보) -천연염료의 개발가치 평가- (A Preliminary Study on Natural Dyeing by the Delphi Method (Part III) -Developing Valuation of Natural Dyes-)

  • 유명님;노의경
    • 한국의류학회지
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    • 제30권5호
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    • pp.733-741
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    • 2006
  • This study was to investigate categories of valuation and make the standard on developing valuation of natural dyes by Delphi method. The three-round Delphi tests were performed with 36 professional in the academic, the industrial, and the art field.'Dyeability property' meant levelling, adsorption, color diversity with mordant, color stability, 'marketability', possibility of mass production, economical efficiency, functionality, demand and supply of natural dyes, 'color', yield, beautiful color, value of color and 'color fastness', washing, perspiration and light fastness. Indigo, persimmon, cochineal, safflower and onion in dyeability property were evaluated highly, functional natural dyes in marketability, red and purple color ones except indigo in color and ones containing tannin in color fastness.

디젤연소용기에 직접분사된 천연가스와 파일럿오일의 복합연소 모델링 (Modeling the Dual-Fuel Combustion of Natural Gas and Pilot Distillate Injected Directly into a Diesel Combustion Bomb)

  • 최인수
    • 한국자동차공학회논문집
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    • 제4권1호
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    • pp.155-164
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    • 1996
  • Dual-fuel engines are being researched with emphasis on the possible types of natural gas supply systems. Hence, a three-dimensional combustion model by using finite volume method was developed to provide a fundamental understanding of the auto-ignition of pilot distillate and subsequent burning of natural gas, when the natural gas as well as the distillate was directly injected into a quiescent diesel engine like combustion bomb tests and the numerical results were investigated for the mixed combustion phenomena. With high-pressure natural gas injection, it was found that the gaseous fuel injection characteristics had to be well harmonised with that of the pilot distillate. For better combustion efficiency, however, further researches are required for the optimisation of injection system in the existence of air motion.

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국제표준화기구 ISO/NP 16266 방법을 이용한 환경 중 Pseudomonas aeruginosa의 분리 및 동정 (Isolation and Identification of Pseudomonas aeruginosa in Natural Environments by International Organization for Standardization ISO/NP 16266)

  • 이시원;김지혜;이보람;주윤리;최별;박수정;정현미;정원화
    • 미생물학회지
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    • 제50권4호
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    • pp.384-386
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    • 2014
  • 녹농균은 병원, 물, 토양 및 대기 등의 많은 자연과 인공환경에서 서식하는 기회주의적 병원체로, 병원 내 감염 등의 심각한 문제점을 야기할 수 있다. 본 연구에서는 신뢰높은 표준화 방법인 International Organization for Standardization (ISO)을 적용하여, 물과 토양에서 220개의 녹농균의 추정 집락을 분리하였으며, 생리생화학적 특성으로 녹농균을 동정하였다. ISO/NP 16266 방법을 적용하였을 때, 총 220개의 추정 집락 중 방류수에서 drain swab으로 채취한 오직 1개의 집락만이 최종적으로 녹농균 양성으로 확정되었다. 한편, ISO에서 2014년 새롭게 제안한 1,10 phenanthroline 저항성 실험은, 환경 중 P. aeruginosa를 검출 및 동정하기 위해 적합한 방법으로 사료된다.

천연 소재 복합물이 고지방사료로 유도된 비만 생쥐의 조직형태 및 조직병리학적 변화에 미치는 영향 (The Effect of Natural Mixture Supplementation on Histopathological and Histomorphometrical aspects in High Fat Diet-induced Obese Mice)

  • 신인순;최혜민;구세광;김미려
    • 대한본초학회지
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    • 제27권4호
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    • pp.53-58
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    • 2012
  • Objective : Obesity is often defined as a condition associated with accumulations of excessive body fats which resulting from disorder of energy balance in term of energy intake and energy expenditure. Methods : The effects of natural mixture (T) for inhibition of lipid metabolism on the liver, epididymal fat pads and pancreatic zymogen granules of high fat diet (HFD) supplied rats were observed by histopathology and histomorphometry. Results : As results of HFD supply, severe steatohepatitis such as increases of mean diameters of hepatocytes and the percentages regions of fatty changes was detected. In addition, hypertrophy of adipocytes (increase of mean diameters of epididymal fat pads) was also detected with dramatic decreases of pancreatic zymogen granules at histopathological and histomorphometrical observations. However, theses steatohepatitis and hypertrophy of adipocytes induced by HFD supply were inhibited by treatment of 5 % and 10 % T (T5, T10), respectively. Well corresponded as the results of adipocyte hypertrophy and steatohepatitis, the decreases of pancreatic zymogen granules were also dose-dependently inhibited by T treatment as compared with HFD control, respectively. Conclusion : In conclusion, based on the results, it is considered that test materials, T5 and T10, will be showed hepatoprotective and anti-obese effects, may be directly and/or indirectly mediated by pancreatic zymogen granules because they dose-dependently inhibited steatohepatitis, hypertrophy of adipocytes and decreases of pancreatic zymogen granules induced by HFD supply, respectively.

멀티에이전트 기반 SCM 모델링 및 구현 (Multiagent Enabled Modeling and Implementation of SCM)

  • 김태운;양성민;서대희
    • 한국정보시스템학회지:정보시스템연구
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    • 제12권2호
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    • pp.57-72
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    • 2003
  • The purpose of this paper is to propose the modeling of multiagent based SCM and implement the prototype in the Internet environment. SCM process follows the supply chain operations reference (SCOR) model which has been suggested by Supply Chain Counsil. SCOR model has been positioned to become the industry standard for describing and improving operational process in SCM. Five basic processes, plan, source, matte, deliver and return are defined in the SCOR model, through which a company establishes its supply chain competitive objectives. A supply chain is a world wide network of suppliers, factories, warehouses, distribution centers and retailers through which raw materials are acquired, transformed or manufactured and delivered to customers by autonomous or semiautonomous process. With the pressure from the higher standard of customer compliance, a frequent model change, product complexity and globalization, the combination of supply chain process with an advanced infrastructure in terms of multiagent systems have been highly required. Since SCM is fundamentally concerned with coherence among multiple decision makers, a multiagent framework based on explicit communication between constituent agents such as suppliers, manufacturers, and distributors is a natural choice. Multiagent framework is defined to perform different activities within a supply chain. Dynamic and changing functions of supply chain can be dealt with multi-agent by cooperating with other agents. In the areas of inventory management, remote diagnostics, communications with field workers, order fulfillment including tracking and monitoring, stock visibility, real-time shop floor data collection, asset tracking and warehousing, customer-centric supply chain can be applied and implemented utilizing multiagent. In this paper, for the order processing event between the buyer and seller relationship, multiagent were defined corresponding to the SCOR process. A prototype system was developed and implemented on the actual TCP/IP environment for the purchase order processing event. The implementation result assures that multiagent based SCM enhances the speed, visibility, proactiveness and responsiveness of activities in the supply chain.

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SWMM 모형을 활용한 평야부 관개효율 및 용수공급 취약성 평가 (Assessment of Irrigation Efficiency and Water Supply Vulnerability Using SWMM)

  • 신지현;남원호;방나경;김한중;안현욱;이광야
    • 한국농공학회논문집
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    • 제62권6호
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    • pp.73-83
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    • 2020
  • Agricultural drought is a natural phenomenon that is difficult to observe and quantitatively express, and agricultural water use is high and usage patterns are diverse, so even if there is a lack of rainfall. The frequency and severity of agricultural drought are increased during the irrigation period where the demand for agricultural water is generated, and reasonable and efficient management of agricultural water for stable water supply is required. As one method to solve the water shortage of agricultural water in an unstructured method, it is necessary to analyze the appropriate supply amount and supply method through simulation from the intake works to the canals organization and paddy field. In this study, irrigation efficiency was analyzed for irrigation systems from April to September over the past three years from the Musu Reservoir located in Jincheon-gun, Chungcheongbuk-do and Pungjeon Reservoir located in Seosan-si, Chungcheongnam-do. SWMM (Storm Water Management Model) was used to collect agricultural water, and irrigation efficiency analysis was conducted using adequacy indicators, and water supply vulnerability. The results of the agricultural water distribution simulation, irrigation efficiency and water supply vulnerability assessment are thought to help the overall understanding of the agricultural water supply and the efficient water management through preliminary analysis of the methods of agricultural water supply in case of drought events.

복합화력발전의 가스연료 공급계통에 대한 위험도 평가 기법 연구 (I) : API RBI 절차에 기반한 위험도 평가 (Risk Assessment Technique for Gas Fuel Supply System of Combined Cycle Power Plants (I) : Based on API RBI Procedures)

  • 송정수;유종민;한승연;최정우;윤기봉
    • 에너지공학
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    • 제27권2호
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    • pp.1-13
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    • 2018
  • 미세먼지 저감 및 에너지원 변환에 대한 정책 추진에 따라 천연가스를 연료로 하는 발전의 비중이 확대되고 있다. 복합화력발전 플랜트, 열병합발전 플랜트 등에서 천연가스 연료공급계통이 가스가 가열된 상태에서 고압으로 운용되고 있으므로, 누출사고를 예방하여 화재 및 폭발에 의해 사고를 방지하여야 한다. 본 연구에서는 API RP 581 RBI 코드를 기반으로 복합화력발전 플랜트의 천연가스 연료공급계통을 대상으로 위험도 평가를 수행하였다. API RBI 코드의 적용을 위해 평가 대상 계통의 라인 및 세그먼트를 구분하였다. 파손확률과 파손피해 산출을 위해 운전 데이터 및 입력 정보를 분석하였다. 설치 초기 시점 및 운전시간 경과에 따른 위험도 평가 결과 추이를 분석하였다. 코드 기반 평가 시 가스연료 공급계통은 두께 감육, 외부 손상, 기계적 피로 손상기구의 영향이 주로 반영되었다. 운전 시간이 경과함에 따라 단열재 하부 부식(CUI, Corrosion Under Insulation) 등에 의한 외부손상이 위험도를 상승시키는 원인으로 예상되었다.