• 제목/요약/키워드: school zones

검색결과 480건 처리시간 0.026초

Synthesis and Biological Activity of Geranyloxy Compounds

  • Oh, Hyun-Ju;Oh, In-Kio;Na, Young-Soon;Kim, Myung-Ju;Baek, Seung-Hwa
    • 동의생리병리학회지
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    • 제19권3호
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    • pp.792-796
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    • 2005
  • Disk assays on the compounds (10 and 12) showed both to have antifungal activity against the dermatophytic fungus Trichophyton mentagrophytes ATCC 28185, (1 and 3 mm inhibition zones at $60\;{\mu}g/disc$), but not against the Gram-positive bacterium B. subtilis or the Gram-negative bacteria Escherichia coli and Pseudomonas aeruginosa or fungi Cladosporium resinae and Candida albicans. However, the compound (13) did not show against antifungal activity. The geranyloxy compounds (10, 12, and 13) were cytotoxic to P388 murine leukaemia cells ATCC CCL 46 P388D1, ($IC_50$ >6,250 ng/mL at $7.5\;{\mu}g/disc$). These results suggest that The geranyloxy compounds possesses antimicrobial and antitumor activities.

엔진 배기매니폴드의 배기가스 누설 해석 (Leakage Analysis of the Exhaust Gas for the Engine Exhaust Manifold)

  • 최복록
    • 한국자동차공학회논문집
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    • 제15권3호
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    • pp.160-165
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    • 2007
  • Exhaust manifold is generally subjected to thermal cycle loadings ; at hot condition, large compressive plastic deformations are generated, and at cold condition, tensile stresses are remained in highly deformed critical zones. These phenomena originate from that thermal expansions of the runners are restricted by inlet flange connected to the cylinder head, because the former is less stiff than the latter and, the temperature of the inlet flange is lower than that of the runners. Therefore, due to the repetitions of thermal deformation, leakage problems could be occur between inlet flange and cylinder head. In this study, we obtained pressure distributions along gasket bead lines from the finite element analysis and compared to the test results. It shows a good agreement between numerical and experimental results.

선박용 디젤기관의 주철부품 보수용접 특성에 관한 연구 (A Study on Characteristics of Repair Welding for Cast Iron Part of Diesel Engine for Ship)

  • 강명신;김진경;김영식
    • 한국해양공학회:학술대회논문집
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    • 한국해양공학회 2004년도 학술대회지
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    • pp.283-287
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    • 2004
  • Arc welding is sometimes used to repair damaged cast iron parts in diesel engine for driving a ship. In this case cola arc welding. is good for. saving the time and results in good repairing. But if some difference in hardness on welding zones made with AWS E Ni-CI and NiFe-CI. happen, repaired parts would be cracked in a short. In order to overcome this default, the study is performed on varying preheating temperature of welding parts, selecting welding rod and welding work way. The result will be used on ship's repair working shop.

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EGR 성층화급기에 의한 DME HCCI 연소시의 압력 상승률 저감에 관한 연구 (A Study about the Effects of EGR Stratification on Reducing the Pressure RIse Rate of DME HCCI Combustion)

  • 임옥택
    • 한국수소및신에너지학회논문집
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    • 제22권6호
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    • pp.895-904
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    • 2011
  • Stratified charge has been thought as one of the ways to avoid a sharp pressure rise on HCCI combustion. The purpose of this study is to evaluate the potential of stratified charge for reducing PRR on HCCI combustion. The pre-mixture with thermal, mixing and EGR stratifications is charged in Rapid Compression Machine. After that, the pre-mixture is compressed and in that process, in-cylinder gas pressure and temperature are analyzed. Additionally numerical calculation with multi-zones modeling is run to know the potential of stratified charge for reducing PRR.

움직임 물체 검출 기반 학원 통학차량 승하차 위험 경고 시스템 (Motion Object Detection Based Hagwon-Bus Boarding Danger Warning System)

  • 송영철;박성령;양승한
    • 전기학회논문지
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    • 제63권6호
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    • pp.810-812
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    • 2014
  • In this paper, a hagwon-bus boarding danger warning system based on computer vision is proposed to protect children from an accident causing injuries or death. Three zones are defined and different algorithms are applied to detect moving objects. In zone 1, a block-based entropy value is calculated using the absolute difference image generated by the absolute differential estimation between background image and incoming video frame. In zone 2, an effective and robust motion object tracking algorithm is performed based on the particle filter. Experimental results demonstrate the efficient and effectively of the algorithm for moving object inspection in each zone.

On the material properties of shell plate formed by line heating

  • Lim, Hyung Kyun;Lee, Joo-Sung
    • International Journal of Naval Architecture and Ocean Engineering
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    • 제9권1호
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    • pp.66-76
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    • 2017
  • This paper is concerned with investigating the plastic material properties of steel plate formed by line heating method, and is aimed at implementing more rational design considering the accidental limit states such as collision or grounding. For the present study, line heating test for marine grade steel plate has been carried out with varying plate thickness and heating speed, and then microscopic examination and tensile test have been carried out. From the microscopic, it is found that the grain refined zones like ferrite and pearlite are formed all around the heat affected zone. From the tensile test results, it is seen that yield strength, tensile strength, fracture strain, hardening exponent and strength coefficient vary with plate thickness and heat input quantity. The formulae relating the material properties and heat input parameter should be, therefore, derived for the design purpose considering the accidental impact loading. This paper ends with describing the extension of the present study.

Electrical Machines and Drives for Potentially Explosive Atmospheres

  • Grantham, Colin
    • Journal of international Conference on Electrical Machines and Systems
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    • 제1권1호
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    • pp.128-134
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    • 2012
  • This paper gives an overview of the requirements for electrical equipment in potentially explosive atmospheres and describes how these are applied to electrical machines and drives in hazardous areas. The method by which equipment can be shown to be safe in a whole range of gases, by testing in a single test gas, is covered. It is shown how the more recently introduced methods of protection for hazardous areas, increased safety and nonsparking, are ideally suited to AC machines and drives. A novel method of measuring the fullload temperature rise of electrical machines for hazardous, and other areas, without the need to connect a mechanical load to the machine's drive shaft is explained.

Comparison of Power Loss and Magnetic Flux Distribution in Octagonal Wound Transformer Core Configurations

  • Cinar, Mehmet Aytac;Alboyaci, Bora;Sengul, Mehlika
    • Journal of Electrical Engineering and Technology
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    • 제9권4호
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    • pp.1290-1295
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    • 2014
  • In this paper, various configurations of octagonal wound transformer core topology, which has previously proved advantages on conventional wound cores, are studied. Each configuration has different joint types and different placement of joint zones on the core. Magnetic flux distributions and power losses of each configuration are analyzed and compared. Comparisons are based on both 2D&3D finite element simulations and experimental studies. The results show that, joint types and their placements on the core cause local flux accumulations and dramatically affect power loss of the core.

크레인 설비의 검사에 따른 기초연구 (Basic research, according to the inspection of crane equipment)

  • 안태건;심규형;이동호
    • 대한안전경영과학회지
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    • 제14권4호
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    • pp.169-175
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    • 2012
  • Self-Inspection is being used in the workplace hazardous, dangerous machinery and equipment to build capacity for the voluntary safety risks due to use of machinery and prevention of industrial accidents that inspect facilities for safety issues, is to check. However, December 31, 2008 as part of Article 36 of the Occupational Safety and Health Act (safety inspection), the financial vanish as the self-test, Safety inspection program has been changed., In each individual workplace that creates its own standards and regulations to use the existing inspection system is in some cases. This study is located in the southeast industrial complex as a risk reducer manufacturer, machine-based target zones in S Corp owns most of the crane based on the results of the tests is to analyze the problem. Then check the results - to bring its measures and information you need to know for sure is to propose.

Numerical method for the strength of two-dimensional concrete struts

  • Yun, Y.M.
    • Computers and Concrete
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    • 제28권6호
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    • pp.621-634
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    • 2021
  • For the reliable strut-and-tie model (STM) design of disturbed regions of concrete members, structural designers must accurately determine the strength of concrete struts to check the strength conditions of a selected STM el and the anchorage of reinforcing bars in nodal zones. In this study, the author proposed a consistent numerical method for strut strength, applicable to all two-dimensional STMs. The proposed method includes the effects of a biaxial stress state associated with tensile strains in reinforcing bars crossing a strut, deviation angle between strut orientation and compressive principal stress flow, and degree of confinement provided by reinforcement. The author examined the method's validity through the STM prediction of the ultimate strengths of 517 reinforced concrete (RC) deep beams, 24 RC panels, and 258 RC corbels, all tested to failure.