• Title/Summary/Keyword: Passage Rate

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A Study on Flow Analysis of Model Engine Coolant Flow Passage : Comparison with Experimental Data of Lotus Model and Flow Rate Control (엔진 냉각수 유동통로 모델에 대한 수치해석 : Lotus 모델의 실험 결과와의 비교 및 유량제어)

  • Cho, W.K.;Hur, N.
    • Transactions of the Korean Society of Automotive Engineers
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    • v.3 no.5
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    • pp.17-23
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    • 1995
  • A numerical analysis on engine coolant is made by the use of FVM based general purpose 3 dimensional Navier-Stokes solver, TURB-3D. Numerical solutions are verified by comparison with the experimental data of Lotus model. The results show a good qualitative as well as quantitative comparison. Coolant flow rate control is attempted through adjusting the cross section area of passage base on the results of an original coolant passage. It is concluded from the results that the flow rate control is possible as attempted, and thus can be used in the real engine design.

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The Effect of Partial Blockage of Flow Passage to Performance Change of a Liquid Rocket Engine (유로 단면 부분 폐쇄가 액체로켓엔진 성능 변화에 미치는 영향)

  • Cho, Won Kook
    • Journal of Aerospace System Engineering
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    • v.9 no.4
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    • pp.67-72
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    • 2015
  • The analysis has been performed on the blockage effect at the propellant flow passage in a liquid rocket engine. This simulates an example of emergency situation where flow passage is partially blocked. The analysis method has been validated by predicting the pump head and flow rate within 1% precision against the measured data of turbopump-gas generator coupled test. When the oxidizer passage is reduced it is predicted that the mixture ratio decreases, the oxidizer pump head increases and the gas generator pressure increases. When the fuel passage is reduced it is predicted that the mixture ratio increases, fuel flow rate decreases and the fuel pump head increases.

Improvements of the Public Pedestrian Passage in the Apartment Complex from Crime Prevention Through Environmental Design Aspect (범죄예방 환경설계 관점에서 공동주택 단지 내 공공보행통로의 개선방안 연구)

  • Lee, Seung-Ji
    • Journal of the Architectural Institute of Korea Planning & Design
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    • v.34 no.6
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    • pp.135-142
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    • 2018
  • A public pedestrian passage induces traffic into the apartment complex, and therefore, it requires the application of Crime Prevention Through Environmental Design(CPTED). This paper aims to analyze the conditions and to suggest the improvements of public pedestrian passages in apartment complexes, applying a 3-D approach from CPTED aspect. The first aspect is "Designation": 1)The linkage between the public pedestrian passages is weak, and their designated purpose becomes unclear. 2)When the designated purpose is not considered for each complex, the closure rate is high. 3)The closure rate of the "Through type" is high. It suggests that the pedestrian network should be built and vitalized at the local urban level. The second aspect is "Definition." The public pedestrian passage lacks a social, cultural, and legal definition and only has a passive physical definition. It suggests that a legal definition and specialized guildline be prepared. The third aspect is "Design": 1)Insufficient territoriality exists between the public pedestrian passage and the inside of the complex. Territoriality should be reinforced between the public pedestrian passage and the rest of the internal territory. 2)The landscaping adjacent to the public pedestrian passage lacks deliberation. Since this is where safety and privacy collide, detailed design and maintenance of the landscaping is required. 3)It lacks systematical crime prevention facilities and should compensate accordingly.

Effects of Donor Cell Passage, Size and Type on Development of Porcine Embryos Derived from Somatic Cell Nuclear Transfer

  • Zhang, Y.H.;Song, E.S.;Kim, E.S.;Cong, P.Q.;Lee, S.H.;Lee, J.W.;Yi, Y.J.;Park, Chang-Sik
    • Asian-Australasian Journal of Animal Sciences
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    • v.22 no.2
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    • pp.194-200
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    • 2009
  • The aim of this study was to investigate the effects of donor cell passage, size and type on the development of nuclear transfer embryos. Porcine cumulus cells, fetal fibroblasts and oviductal epithelial cells from 1-2, 3-6 and 7-10 passages were used for the nuclear transfer. In the oocytes with the cumulus donor cells, fusion and cleavage rates of oocytes and cell numbers per blastocyst among the three different passage groups did not show any differences, but the rates of blastocyst formation from 1-2 and 3-6 passage groups were higher than those from 7-10 passage group. The rates of fusion, cleavage and blastocyst formation, and the cell numbers per blastocyst were higher in the embryos with the sizes of <20 and 20 ${\mu}m$ cumulus donor cells compared to the >20 ${\mu}m$ cumulus donor cell. In the oocytes with the fetal fibroblast donor cells, the rate of blastocyst formation from the 3-6 passage group was higher than from 1-2 and 7-10 passage groups. The embryos with the size of 20 $\mu{m}$ fetal fibroblast donor cell showed higher rate of blastocyst formation compared to those with <20 and >20 ${\mu}m$ donor cells. In the oocytes with the oviductal epithelial cells, the rates of blastocyst formation from 1-2 and 3-6 passage groups were higher compared to those from 7-10 passage group. The embryos with the sizes of <20 and 20 ${\mu}m$ oviductal epithelial donor cells had a higher rate of blastocyst formation compared to those with >20 ${\mu}m$ donor cell. Fusion and cleavage rates of oocytes, and cell numbers per blastocyst among the three different donor cell types from the 3-6 passage did not show any differences. However, the rate of blastocyst formation of somatic cell nuclear transfer (SCNT) embryos with the fetal fibroblast donor cell was higher than that of blastocyst formation of SCNT embryos with the cumulus and oviductal epithelial donor cells.

STUDIES IN FIBRE DIGESTION AND PASSAGE RATE OF LIQUID AND SOLID IN CATTLE AND BUFFALOES

  • Abdullah, N.;Ho, Y.W.;Mahyuddin, M.;Jalaludin, S.
    • Asian-Australasian Journal of Animal Sciences
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    • v.4 no.2
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    • pp.137-141
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    • 1991
  • Rumen liquor characteristics and disappearance rate of dry matter were studied in Kedah-Kelantan cattle and swamp buffaloes fed grass of rice straw-based diet. Cobalt-EDTA and chromium mordented fibres prepared from the faecal material were used to determine the liquid and solid particles movement in both animal species fed with rice straw. Swamp buffaloes showed a more intense rumen fermentation activity than Kedah-Kelantan cattle when both species were fed straw-based diet. The buffaloes also demonstrated faster rates of grass and straw degradation in situ. The fluid outflow rate from the rumen of buffalo ($1.06{\pm}0.19l/h$) was observed to be slower than that of cattle ($1.55{\pm}0.01l/h$). No significant differences between cattle and buffaloes were observed in rumen fluid volume and passage rate of small particles from the rumen.

A Study on the Exhaust Gas Recirculation in a MILD Combustion Furnace by Using the Coanda Nozzle Effect (MILD 연소로에서 Coanda 노즐 효과를 이용한 배기가스 재순환에 관한 연구)

  • Ha, Ji Soo;Shim, Sung Hoon
    • Journal of Korean Society of Environmental Engineers
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    • v.35 no.12
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    • pp.967-972
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    • 2013
  • A MILD (Moderate and Intense Low oxygen Dilution) combustion, which is effective in the reduction of NOx, is considerably affected by the recirculation flow rate of hot exhaust gas to the combustion furnace. The present study used the MILD combustor, which has coaxial cylindrical tube. The outside tube of the MILD combustor corresponds to the exhaust gas passage and the inner side tube is the furnace passage. A numerical analysis was accomplished to elucidate the characteristics of exhaust gas entrainment toward the inner furnace with the changes of coanda nozzle geometrical parameters, nozzle passage gap length, nozzle passage length, nozzle angle and expansion length. The optimal configuration of coanda nozzle for the best entrainment flow rate was gap length, 0.5 mm, expansion angle, 4o and expansion length, 146 mm. The nozzle passage length was irrelevant to the exhaust gas entrainement.

Enhanced Proliferation and Altered Intracellular Zinc Levels in Early- and Late-Passage Mouse Aorta Smooth Muscle Cells

  • Moon Sung-Kwon;Ha Sang-Do
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.5 no.1
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    • pp.44-47
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    • 2000
  • Cell growth and DNA synthesis were studied from a cultured early- and late- pas- sage mouse aorta smooth muscle cell (MASMC) because the proliferation of vascular smooth muscle cell (VSMC) is a key factor in development of atherosclerosis. In this study, the cells were cultured in fetal bovine serum (FBS) and stimulated by growth factors such as thrombin and platelet-derived growth factor-BB (PDGF-BB). Compared to the number of early-passage MASMC (passage 3 to 9) the number of late-passage MASMC (passage 30 to 40) in a normal serum state was increased 2 fold at Day 1, 3 and 6 in culture, respectively. Incorporation of $[^3H]$ thymidine into DNA induced by serum, PDGF and thrombin in late-passage MASMC was greater than those in early-passage MASMC. We also examined whether intracellular zinc levels would be an aging factor or not. The intracellular zinc level in early- and late-passage MASMC was monitored by using the zinc probe dye N-(6-methoxy-8-quinolyl)-p-toluenesulfonamide. It is interested that late-passage MASMC increased the intracellular fluorescence level of zinc, more than the early passage MASMC did. The alterations of intracellular zinc level occur concurrently with changes in MASMC proliferation rate during aging. This data suggest that the age-associated changes in zinc concentrations may provide a new in vitro model for the study of smooth muscle cell differentiation.

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Effects of Recipient Oocytes and Donor Cells Condition on in Vitro Development of Cloned Embryos after Interspecies Nuclear Transfer with Caprine Somatic Cell (산양의 이종간 핵이식에 있어서 수핵난자에 따른 공여세포의 조건이 핵이식란의 체외발달에 미치는 영향)

  • 이명열;박희성
    • Reproductive and Developmental Biology
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    • v.28 no.1
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    • pp.13-20
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    • 2004
  • This study was conducted to investigate the developmental ability of caprine embryos after somatic cell interspecies nuclear transfer. Donor cells were obtained from an ear-skin biopsy of a caprine, digested with 0.25% trypsin-EDTA in PBS, and primary fibroblast cultures were established in TCM-199 with 10% FBS. After maturation, expanded cumulus cells were removed by vigorous pipetting in the presence of 0.3% hyaluronidase. The matured oocytes were dipped in D-PBS plus 10% FBS+7.5 $\mu\textrm{g}$/ml cytochalasin B and 0.05 M sucrose. The reconstructed oocytes were electrically fused with donor cells in 0.3 M mannitol fusion medium. After the electofusion, embryos were activated by electric stimulation. Interspecies nuclear transfer embryos with bovine cytoplasts were cultured in TCM-199 medium supplemented with 10% FBS including bovine oviduct epithelial cells for 7∼9 day. On the other hand, the NT embryos with porcine cytoplasts were cultured in NCSU-23 medium supplemented with 10% FBS for 6∼8 day at $39^{\circ}C, 5% CO_2$ in air. In caprine-bovine NT embryos, the cleavage(2-cell) rate was 36.8% in confluence and 43.8% in serum starvation. The developmental rate of morula- and blastocyst-stage embryos was 0.0% in confluence and 18.8% in serum starvation. In caprine-porcine NT embryos, the cleavage(2-cell) rate was 76.7% in confluence and 66.7% in serum starvation. The developmental rate of morula and blastocyst stage embryos was 3.3% in confluence and 3.0% in serum starvation, and no significant difference was observed in synchronization treatment between donor cells. In caprine-bovine NT embryos, the cleavage(2-cell) rate of cultured donor cells was 30.8% and 17.6% in 5∼9 and 10∼14 passage(P<0.05). The developmental rate of morula and blastocyst stage embryos were significantly higher(P<0.05) in 5∼9 passage(23.1%) than in 10∼14 passage(0.0%) of cultured donor cells. In caprine-porcine NT embryos, the cleavage rate was significantly higher(P<0.05) in 5∼9 passage(86.7%) than in 10∼14 passage(50.0%) of cultured donor cells. The developmental rate of morula and blastocyst stage embryos were 3.3 and 0.0% in 5∼9 and 10∼14와 passage of cultured donor cells. In caprine-bovine NT embryos, the developmental rate of morula and blastocyst stage embryos were 22.6% in interspecies nuclear transfer, 33.9% in in vitro fertilization and 28.1% in parthenotes, which was no significant differed. The developmental rate of morula and blastocyst stage embryos with caprine-porcine NT embryos were lower(P<0.05) in interspecies nuclear transfer(5.1%) than in vitro fertiltzation(26.9%) and parthenotes(37.4%).