• 제목/요약/키워드: Marine transport

검색결과 578건 처리시간 0.032초

Gravity Level Dependency of Gas-Liquid Two-Phase Flow

  • Choi, Bu-Hong
    • Journal of Advanced Marine Engineering and Technology
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    • 제27권4호
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    • pp.487-493
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    • 2003
  • More reliable design of thermal transport. Power acquisition and thermal management systems requires the through understanding of the flow hydrodynamic. the differences and similarities between the two-phase flow characteristics of two-Phase flow influenced by the gravity levels. The data of flow Patterns, void fraction, frictional pressure drop associated with their characteristics were obtained at $\mu\textrm{g}$. 1g and 2g. Flow patterns and void fraction data obtained at three gravity levels were compared with each other and previous models and correlations.

Neutron clustering in Monte Carlo iterated-source calculations

  • Sutton, Thomas M.;Mittal, Anudha
    • Nuclear Engineering and Technology
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    • 제49권6호
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    • pp.1211-1218
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    • 2017
  • Monte Carlo neutron transport codes generally use the method of successive generations to converge the fission source distribution to-and then maintain it at-the fundamental mode. Recently, a phenomenon called "clustering" has been noted, which produces fission distributions that are very far from the fundamental mode. In this study, a mathematical model of clustering in Monte Carlo has been developed. The model draws on previous work for continuous-time birth-death processes, as well as methods from the field of population genetics.

신용장통일규칙(UCP)상 운송주선인 운송서류의 수리요건에 관한 연구 (A Study on the Acceptance Conditions of a Freight Forwarder's Transport Document under UCP)

  • 강호경
    • 무역상무연구
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    • 제51권
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    • pp.285-313
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    • 2011
  • There can be analyzed severally on the acceptance conditions of freight forwarder's transport document under UCP. First, Bills of Lading issued by forwarding agents will be refused. This can be seen in the article 20 of 1933 Revision UCP(Brochure 82) and the article 20 of 1951 Revision UCP(Brochure 151). Second, Unless specifically authorized in the credit, Bills of Lading issued by forwarding agent will be rejected. It is prescribed in the front part (a) of article 17 of 1962 Revision UCP(Brochure 222) and the article 19 of 1974 Revision UCP(Publication No. 290). Third, Acceptance conditions are different according to the type of transport documents, that is either Bill of Lading or not. It is prescribed in the art 25 and article 26 of 1983 Revision UCP. Unless otherwise stipulated in the credit, transport document issued by a freight forwarder will be rejected unless it is the FIATA Combined Transport Bill of Lading approved by the International Chamber of Commerce or otherwise indicates that it is issued by a freight forwarder acting as a carrier or agent of a named carrier. On the other hand, unless otherwise stipulated in the credit, marine bill of lading issued by a freight forwarder will be rejected, unless it indicates that it is issued by such freight forwarder acting as a carrier, or as the agent of a named carrier. Fourth, transport documents issued by a freight forwarder will be accepted. This can be found in the article 30 of 1993 Revision UCP(ICC Publication No. 500) and the article 14 l of 2007 Revision UCP(ICC Publication No. 600). According to the former unless otherwise authorized in the Credit, transport document issued by a freight forwarder will only be accepted if it is appears on its face to indicate the name of the freight forwarder as a carrier or multimodal transport operator or its agent. The latter prescribed that a transport document will be accepted if it is issued by a freight forwarder by a agent of carrier or freight forwarder itself.

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제주지역 오존 및 미세먼지 고농도일의 기류패턴에 따른 농도변화와 기상조건 분석 (Variations of Ozone and PM10 Concentrations and Meteorological Conditions according to Airflow Patterns of their High Concentration Episodes on Jeju Island)

  • 한승범;송상근;최유나
    • 한국환경과학회지
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    • 제26권2호
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    • pp.183-200
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    • 2017
  • The classification of airflow patterns during high ozone ($O_3$) and $PM_{10}$ episodes on Jeju Island in recent years (2009-2015), as well as their correlation with meteorological conditions according to classified airflow patterns were investigated in this study. The airflow patterns for $O_3$ and $PM_{10}$ were classified into four types (Types A-D) and three types (Types E-G), respectively, using the HYbrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model and synoptic weather charts. Type A was the most dominant airflow pattern for $O_3$ episodes, being characterized by the transport of airflows from urban and industrial areas in China with the highest frequency (about 69%, with a mean of 67 ppb). With regard to the $PM_{10}$ episodes, Type E was the most dominant airflow pattern, and was mostly associated with long distance transport from Asian dust source regions along northwesterly winds, having the highest frequency (about 92%, with a mean of $136{\mu}g/m^3$). The variations in the concentration of $O_3$ and $PM_{10}$ during the study period were clarified in correlation with two pollutant and meteorological variables; for example, the high (low) $O_3$ and $PM_{10}$ concentrations with high (low) air temperature and/or wind speed and vice versa for precipitation. The contribution of long-range transport to the observed $PM_{10}$ levels in urban sites for different airflow patterns (Types E-F), if estimated in comparison to the data from the Gosan background site, was found to account for approximately 87-93% (on average) of its input. The overall results of the present study suggest that the variations in $O_3$ and $PM_{10}$ concentrations on Jeju Island are mainly influenced by the transport effect, as well as the contribution of local emissions.

인천-개성 항로 바지 수송시스템 구축에 관한 기초적 연구 (A Study on Construction of Barge Transportaion System between Incheon and Gaesung)

  • 김상현;이승희;이영길;유진원
    • 해양환경안전학회지
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    • 제14권3호
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    • pp.227-233
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    • 2008
  • 최근 남북한의 경제교류 증대 및 개성공단의 발전에 따라 남북한의 물동량은 급속히 증가하고 있다. 또한 인천과 개성 사이의 물류 수송을 위하여 육상수송뿐만이 아니라 다양한 물류 수송 및 수송로의 제공이 요구되고 있다. 이 논문에서는 인천과 개성 사이의 바지 운송시스템 구축에 대하여 고찰한다. 적은 초기 투자비용, 적하역 및 접안 편이성 등과 같은 유리한 점을 가진 바지 운송시스템은 유럽 및 미국 등에서 널리 사용되고 있다. 먼저 본 논문에서는 바지 운송 항로, 해상 물동량 및 바지와 푸셔로 구성되는 바지 선단 등에 대하여 고찰한다. 그 다음에 바지 해상항로 조건 및 바지 선단 등에 기초하여 바지 및 푸셔의 선형 및 일반배치 설계를 수행한다. 마지막으로 바지 항로 운영 방안, 적하역 시설, 물류 센터 및 복합 수송 등과 같은 바지 해상항로 구축 방안에 대하여 고찰한다.

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독성 Alexandrium tamarense 의 EST 분석 및 삭시톡신 생합성 유전자의 확인 (Expressed Sequence Tag Analysis of Toxic Alexandrium tamarense and Identification of Saxitoxin Biosynthetic Genes)

  • 장만;이주연;정영재;이건섭;김동균;이택견
    • 한국산학기술학회논문지
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    • 제14권7호
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    • pp.3582-3588
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    • 2013
  • A. tamarense로부터 ESTs library를 제작하였다. 이들의 염기서열을 분석하여 STX 생합성 관련 유전자를 클로닝하였다. 연구결과 827 클론의 염기서열이 분석되었고, 564개의 EST가 GenBank에서의 Blast search를 사용하여 기능에 따라 분류되었다. EST에서의 주요 유전자는 cellular organization, cell metabolism, energy, cell cycle과 DNA processing, cellular transport와 transport, cell rescue, defense, death와 aging 및 transcription 등으로 분석되었다. 특히 S-adenosylmethionine synthetase와 H2A histone family 유전자의 발현이 독성 A. tamarense에서 증가하였다. 이러한 결과는 두 개의 유전자가 A. tamarense에서의 삭시톡신 생합성을 검출하기 위한 좋은 바이오마커가 될 수 있음을 보여준다.

2010년 3월 극심한 황사사례의 발생 및 수송과정에 관한 연구 (A Study on the Outbreak and Transport Processes of the Severe Asian Dust Event Observed in March 2010)

  • 김석우;송상근;한승범
    • 한국대기환경학회지
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    • 제32권3호
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    • pp.256-271
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    • 2016
  • The source and transport of the severe Asian dust event (ADE) recently observed in the Korean peninsula were analyzed based on observations (surface weather charts and satellite data) and modeling study (WRF-CMAQ modeling systems). The ADE occurred on 20-21 March 2010 in South Korea with very high $PM_{10}$ concentrations (up to approximately $3,000{\mu}g/m^3$ in Daegu and Jeju). The dominant meteorological conditions affecting the dust outbreak and transport processes were found to be associated with the two synoptic features: (1) strong airflows (i.e., westerlies) induced by a strong pressure gradient resulting from a dense isobar pattern (west-high and east-low) between Tuva Republic and Mongolia and (2) a rapid movement of the strong westerlies merged with airflows generated near Gobi Desert and Inner Mongolia. The merged strong westerlies with a low pressure played a pivotal role in the huge amount of AD and its transport height of 5-8 km. The time and location of dust emissions calculated in the source regions were similar to those observed in the weather charts and satellite image. The ADE simulation mostly showed agreement in the patterns and the concentration levels of modeled dust (including $PM_{10}$) with those of the observations.

한국 남동해역 취송순환문제에서 바람응력에 대한 최적화 연구 (An optimization strategy in wind-driven circulation with uncertain forcing problem off the southeastern coastal waters of Korea)

  • 김종규;김헌태
    • 한국해양환경ㆍ에너지학회지
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    • 제4권2호
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    • pp.35-42
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    • 2001
  • 한국 남동해역 취송순환에서의 부정확한 외력의 바람응력 문제에 대한 최적화 방법의 유용성에 관하여 검토하였다. 바람응력은 모델 및 수치적 정식화 과정에서 상층 경계조건 및 외력항으로 고려되었다. 그리고 바람응력 평가에 대한 최적화 방법의 적용성 및 모델변수의 초기값 추정치의 중요성을 검토하였다. 최적화 연구로부터 동해 남부해역의 취송순환에 관한 동한난류의 수송량 변화 및 통해 난수층의 형성과 분포특성을 바람응력, 바람응력 회전성 및 상층두께의 변동으로부터 파악할 수 있음을 확인하였다.

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