• Title/Summary/Keyword: Opening Up

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Startup Analysis of Staged Combustion Cycle Engine Powerpack (다단연소사이클 엔진 파워팩 시동해석)

  • Lee, Suji;Moon, Insang
    • Journal of the Korean Society of Propulsion Engineers
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    • v.20 no.3
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    • pp.1-8
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    • 2016
  • It was examined that start-up characteristics of a staged combustion cycle engine powerpack. Among various parameters, valve opening time was considered as a main factor affecting the start-up characteristics. Using monte-carlo method, characteristics variation was analyzed when the valve opening time deviates from the nominal value. As a result, the main fuel valve opening time and the start turbine ending time were significant associated with the startup characteristics. When separating main fuel valve opening time and start turbine stop time, main fuel valve opening time was an important factor. For stable operation, the main fuel valve opening time must be set one second before after driving the start turbine. Likewise, it was confirmed that the startup analysis can suggest an appropriate startup sequence for a stable startup.

Effects of Vacuum Paokaging on Lipid Oxidation and Meat Color of Chilled Pork (진공포장이 냉장돈육의 지질산화 및 육색에 미치는 영향)

  • 양종범;고명수;문윤희
    • The Korean Journal of Food And Nutrition
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    • v.15 no.1
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    • pp.1-6
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    • 2002
  • This study was conducted to investigate the effects of vacuum packaging on lipid oxidation and meat color of chilled pork. During storage meats wert evaluated for TBA values, pH, blooming time and CIE L$\^$*/a$\^$*/b$\^$*/ values. The TBA values of wrapped meats increased rapidly after 7days and Those of vacuum packaged meats maintained at low level up to 30 days of storage. The pH of wrapped meats increased rapidly after 7days, while those of vacuum packaged meats increased slowly up to 30 days of storage. The bloom time of vacuum packaged meals was 30 min after opening. The CIF L$\^$*/ values of wrapped meats decreased rapidly on the 7th day, while those of vacuum packaged meats directly after opening decreased slightly up to 7days of storage and thereafter increased gradually. The CIE a$\^$*/ values of wrapped meats increased gradually up to 7days and thereafter decreased rapidly, while those of vacuum packaged meats directly after opening were lower than those of wrapped meats. The CIE a$\^$*/ values of vacuum packaged meats after 30 min in the air were higher than those of vacuum packaged meals directly after opening. The CIE b$\^$*/ values of wrapped meats increased rapidly on 4th day and thereafter decreased rapidly, while those of vacuum packaged meats directly after opening were lower than those of wrapped meats. The CIE b$\^$*/ values of vacuum packaged meats after 30 min in the air were higher than those of vacuum packaged meats directly after opening.

Hydro-mechanical Behavior of a Circular Opening Excavated in Saturated Rockmass (포화된 암반에 굴착된 원형공동의 수리-역학적 거동)

  • Lee Youn-Kyou;Shin Hee-Soon
    • Explosives and Blasting
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    • v.23 no.2
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    • pp.23-35
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    • 2005
  • Excavation of an opening in a saturated porous rock may lead to the development of pore pressure around the opening due to the redistribution of initial rock stresses. The built-up of pore pressure, in turn, may affect the mechanical behavior of rock mass and give the different pattern of stress distribution around the opening from that of the case where the coupling is neglected. In this study, the short time response of an opening excavated in saturated ground under anisotropic initial stress conditions was investigated numerically. Not on the wall of opening but at a short distance from the wall, the tangential stresses were peak during the short period after excavation when the hydro-mechanical coupling is considered.

Experimental Study on Flame Trajectory in Building External Walls Fire (건축물 외벽화재시 Flame Trajectory 추정을 위한 실험적 연구)

  • Shin, Yi-Chul;Park, Kye-won;Jeong, Jae-Gun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.79-80
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    • 2016
  • In the event of a fire on the outer walls of an architectural structure, through real scale experiments with the purpose of estimating the Flame Trajectory, the behavior and risks of expanded combustion to an upper architectural compartment of the Fire Plume Ejected from an Opening according to changes in the aspect ratio of the opening were examined. The results showed that the more the heat release rate of the fire source increased, the heat capacity of the Fire Plume Ejected from the Opening also increased, and for the case of heptane when compared with methanol or ethanol, the results showed a trend for a significant amount of unburned gas to remain. The results also showed that the larger the aspect ratio was, the more likely it was for the Flame Trajectory to approach the outer walls and rise up. In each of the experiment conditions, as the flame rose from the lower part of the wall to the upper part of the wall, a steady decrease was shown for the temperature distribution. Also by quantitatively analyzing the amount of unburned gas that remained, a method to estimate the temperature of the Fire Plume Ejected from an Opening for a traverse opening was implemented.

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Prospects for the Management of Shanghai Harbour

  • He Yegang
    • Proceedings of the KOR-KST Conference
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    • 1993.07a
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    • pp.99-105
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    • 1993
  • This Article analyses the present situation of Shanghai Harbour and the Harbour's important role in the development of chinese economy. The article forecasts that the yearly tonnage turnover of the port will reach about 200 million tons in the year of 2000, possibly reach to 270--300 million tons by the end of 2020. it also forecasts that the container handling capacity of the port will be 2 million TEUS in 2000 and 6 million TEUS in 2020 respectively. In order to keep pace with the present situation of opening up and developing Pudong new area, this article suggests that the strategic target of the management and development of Shanghai Harbour should be : grasp the opportunity of opening up and developing Pudong, take the building of the deep-waterway port as the main task, which can accept the third or fourth generation international container ships, bring into full play the traditional advantages the Harbour has, unfold the businesses in other fields, participate in the marketing competition, speed up the development of the Harbour itself, make efferts to build Shanghai Harbour into a port-industry-trade-transportation integral modernized international deep-water key port.

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A Subjective Study on the Reverberation Characteristics of Coupled Spaces (음향적으로 결합된 공간의 주관적 잔향감에 관한 연구)

  • Jeong, Dae-Up;Choi, Young-Ji
    • Journal of Korean Association for Spatial Structures
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    • v.8 no.3
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    • pp.65-73
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    • 2008
  • The present work deals with subjective assessments to propose the objective parameter related to the subjective attribute of reverberation in the coupled room varied the aperture opening size. A 1/10 scale model was built and used for the measurements and subjective assessments. For the subjective tests, binaural impulse responses(BIRs) were measured using a dummy head and the measured BIRs were convolved with anechoic recorded music for the presentation over the headphones. The results showed that the perceived reverberation was the largest in the aperture opening size 12.5%(1.97% of mail) room surface area)and decreased with increasing the aperture opening size over 25% (3.94% of main room surface area) in the main room coupled with the secondary reverberant room. In the main room coupled with the secondary absorptive room, there was no changes in the perceived reverberation up to the aperture opening size 6.25%(0.99% of main room surface area) and it gradually decreased with increasing the aperture opening site over 12.5%. The objective parameter, T30/T15, showed a very low correlation with the perceived reverberation in the coupled room varied the aperture opening size but showed a high correlation with a new objective parameter, T30/Tbp, proposed by the authors. Because the late part decay energy more rapidly increases with increasing the aperture opening site than the early and middle part decay energy, the LDT/EDT or T3/T1 is a better quantifier to measure double slopes in the coupled room than the T30/T15.

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Estimation of Maintenance Flow for Suitable Utilization of Fishway (어도의 적절한 이용을 위한 유지유량 평가)

  • Kim, Seok-gyu;Kim, Chul;Kim, Seonghwan;Ko, Kwangyong
    • Journal of Korean Society on Water Environment
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    • v.25 no.2
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    • pp.281-287
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    • 2009
  • Achieved monitoring regularly about fishway that is a intake dam belongings to Kyeongchon for 5 years. Result that achieve monitoring, discovered pressing issue of opening and closing degree of discharge control part in fishway. In this research, analyze discharge relation with fishway and intake sluice and presented operation plan of opening and closing of discharge control part. Investigated necessity intake discharge and benefited area to analyze relation of discharge that is flowed in fishway and discharge escaping by intake sluice. When opened discharge control part step by step gradually, analyzed discharge. Compared with survey discharge making ration curve of fishway and intake sluice using orifice and submerged weir formula. Because operation of intake dam is necessary intake discharge and upriver inflow discharge by time, operation uses by survey discharge and calculated opening discharge of fishway by opening discharge of intake sluice via monthly inflow discharge. To sum up, calculated floodgate opening height of fishway by water level to present maintenance standard of intake dam.