• Title/Summary/Keyword: transport rate

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A Study on Prediction of Sediment and Riverbed Variation According to Sediment Transportation Functions (유사량 산정공식에 따른 유사 및 하상변동 예측에 관한 연구)

  • Go, Su Hyeon;Song, In Ryeol;Kim, Chang Seok
    • Journal of Environmental Science International
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    • v.13 no.3
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    • pp.263-277
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    • 2004
  • The purpose of this study is to analyze the characteristics of riverbed variation due to the sediment protection weir located on the estuary of the main stream of Taehwa river using I-D finite difference model, HEC-6 model, and the followings are the results of estimating sediment transport rate, amount of scour or deposition, and accumulated amount of deposit according to before and after of the sediment protection weir removal with various flow rates in the channel. Ackers-White transport function produced the greatest sediment transport rate while Meyer-Peter showed the smallest sediment transport rate at the most down stream area of the watershed through the sediment transport rate analyses for various flow rates according to the existence or nonexistence of the sediment protection weir. Toffaleti's and Colby transport function were closest to the average value, and the difference among the results of the sediment transport functions showed up to 8~9 times. Duboy's transport function produced the greatest riverbed variation while Toffaleti's showed the smallest variation through the riverbed variation analyses according to the existence or nonexistence of the sediment protection weir. Yang's was closest to the average value, and the difference among the results of the riverbed variation analyses ranged from 1.4 times to 11 times. It is thought that a sediment transport function must be selected very carefully with respect to the criteria of sediment yield estimation because the analysis results of the sediment transport rate and riverbed variation according to flow rates showed significant differences among the sediment transport functions, and the differences of sediment transport rate and riverbed variation according to the various sediment transport functions decreased as the flow rate increased.

Water Vapor Transport Properties of Nonwoven Batting Materials (부직포 충전재의 수분투파성)

  • Kim, Hui-Suk;Na, Mi-Hui;Kim, Eun-Ae
    • Journal of the Korean Society of Clothing and Textiles
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    • v.22 no.1
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    • pp.72-79
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    • 1998
  • Journal of the Korean Society of Clothing and Textiles Vol. 22, No. 1 (1998) p. 72∼79 The purpose of this study was to investigate the effects of geometrical structure and fiber type on the water vapor transport properties of nonwoven batting materials. Two types of fiber were used such as polyester and wool. Correlation between physical properties of nonwovens and water vapor transport rate was analyzed by Pearson Correlation. Steady and dynamic state water vapor transport properties were measured by absorption, evaporation and cobaltots chloride method respectively. The results were as follows: 1) In geometrical structure, thickness of nonwovens was effected on absorption and evaporation rate and air permeability was more influencing factor on water vapor transport rate than porosity. There were no decreasing of water vapor transport rate in hydrophilic fiber at high relative humudity. 2) The hydrophilicity of fiber affected steady and dynamic state water vapor permeabilities and wool nonwoven showed higher water vapor transport rate than polyester at high relative humidity. 3) Thickness showed higher correlation coefficient with water vapor transport rate than other physical properties of nonwovens.

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Investigation on the Survival and Hatching Rate of Fertilized Eggs in Olive Flounder Paralichthys olivaceus During Commercial Transport Conditions (넙치(Paralichthys Olivaceus) 수정란 수송조건에 따른 생존율 및 부화율 조사)

  • Suh, Jong-pyo;Yoon, Young-seock;Kim, Sung-hyun;Lee, Woo-jai;Lee, Chi-Hoon;Lee, Young-Don
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.53 no.4
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    • pp.486-491
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    • 2020
  • This study was investigated the survival and hatching rate of fertilized eggs in olive flounder Paralichthys olivaceus at water temperature, salinity, duration of transport and different stock densities during commercial transport. The observed optimal temperature during transport was 17.5℃ similar to the natural environmental conditions. The proper salinity was observed to be at 33 psu (practical salinity unit) in both surviving and hatching rate. In terms of the duration of transport, there were no differences until 12 hours between survival and hatching rate, but shorter time of transport would be better. With the best conditions during transport, 20,000 eggs/L were handled in both survival and hatching rate. These results can be essential in the production and transport of healthy olive flounder seeds.

Effect of Sugar Starvation on the Sugar Transport System in Suspension Cultures of Streptanthus trotus (Streptanthus tortus 배양 세포에서 당류고갈이 당류 수송계에 미치는 영향)

  • 조봉희
    • Korean Journal of Plant Tissue Culture
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    • v.27 no.1
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    • pp.47-50
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    • 2000
  • In suspension cultures of Streptanthus. the uptake rate of sugar was increased during the ceil starvation of sugar in the medium. The maximal uptake rate obtained with 3 days of cell starvation. Sugar transport system induced by the sugar starvation was completely inhibited by 10 $\mu$M cycloheximide. Plant cells are known to possess only one sugar transport system, but the uptake rate of glucose obtained a saturated kinetic while the one of sucrose had two different kinetics after the sugar starvation. Induced sugar transport systems had different kinetics compared to plant cell. These results showed that higher plants have adaptable ability to induce new sugar transport systems when the environment changed unsuitable.

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Long-Term Shoreline Change and Evaluation of Total Longshore Sediment Transport Rate on Hupo Beach (후포해빈에서 해안선의 장기변화 및 전연안표사량의 추정)

  • Park, Il-Heum;Lee, Young-Kweon
    • Journal of Ocean Engineering and Technology
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    • v.21 no.4
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    • pp.15-20
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    • 2007
  • The harbor siltation by longshore sediment transports has become a serious problem on the East Coast of Korea. A reasonable prediction of the longshore sediment rate is important to approach the siltation problem effectively. In the recently developed 1-line model, the empirical constants of the sediment transport formula, which include the absolute quantity of sediment transport rate and the spatial distribution of breaking wave height by wave deformation, are treated as calibration parameters. Since these constants should be determined by the very long-term shoreline data, the longshore sediment rates are much more reasonable values. The method was applied to Hupo Beach, which has experienced heavy siltation. The authors also discuss long-term shoreline change using aerial photos and the observed wave-induced current patterns. According to the result, the SW-direction sediment transport rate was $146,892m^3/year$, and the NE direction was $2,694,450m^3/year$ at Hupo Beach for the last 11 years. The siltation in Hupo Harbor might be affected by the NE-direction sediment transport from Hupo Beach.

The Effect of Geometrical Structure on the Moisture Transport Properties of Nonwoven Batting Materials (부직포 충전재의 구조적 특성이 수분전달 특성에 미치는 영향-단층구조와 이층구조 부직포의 비교-)

  • 김희숙;나미희
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.6
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    • pp.810-818
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    • 2000
  • The purpose of this study was to analyze the effect of geometrical structure on the moisture transport properties of nonwoven batting materials. Two types of nonwovens were used such as single and double layered nonwovens. Steady and dynamic state water vapor transport properties were measured by absorption, evaporation and cobaltous chloride method respectively. The results of this study were as follows: 1) Geometrical structure affected water vapor evaporation, but there were no differences between single and double layered nonwovens in moisture absorption. Thickness and air permeability were influencing factor on water vapor transport rate. 2) Directionality of double layered nonwoven was observed both in steady and dynamic state moisture transport. There were differences between upper and lower layer of double layered nonwoven both in moisture absorption rate and color change by cobaltous chloride method. 3) In dynamic state of water vapor transport rate, single layered nonwoven reached more rapidly at the established relative humidity. It was confirmed that geometrical structure affected water vapor evaporation and hydrophilicity of fiber affected moisture absorption because there were much more water vapor transport rate by evaporation than absorption within the same period of time.

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Adaptive FEC and Rate Adaptation for High-speed Transport (고속 전송을 위한 적응형 FEC 및 전송률 제어)

  • Chang Hye young;Kim Jong won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.30 no.3B
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    • pp.85-94
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    • 2005
  • In this paper, we propose a reliable high-speed UDP-based media transport with an adaptive error control. The proposed adaptive transport scheme controls the amount of redundancy by monitoring the network in order to adapt to network fluctuations efficiently. The feedback of receiver enables the sender to be aware of current reception status (i.e., rate and type of packet loss) and to estimate the expected network status. Based on this, the proposed transport attempts to enable reliable transport by adaptively controlling the amount of both whole sending rate and the ratio for adaptive FEC code. Experiment with high-speed network has been conducted to verify the performance of the proposed system that demonstrates the enhanced reliability of the proposed transport at the speed of up to several hundred Mbps.

Containment Evaluation of the KN-12 Transport Cask

  • Chung, Sung-Hwan;Choi, Byung-Il;Lee, Heung-Young;Song, Myung-Jae
    • Journal of Radiation Protection and Research
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    • v.28 no.4
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    • pp.291-298
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    • 2003
  • The KN-12 transport cask has been designed to transport 12 PWR spent nuclear fuel assemblies and to comply with the regulatory requirements for a Type B(U) package. The containment boundary of the cask is defined by a cask body, a cask lid, lid bolts with nuts, O-ring seals and a bolted closure lid. The containment vessel for the cask consists of a forged thick-walled carbon steel cylindrical body with an integrally-welded carbon steel bottom and is closed by a lid made of stainless steel, which is fastened to the cask body by lid bolts with nuts and sealed by double elastomer O-rings. In the cask lid an opening is closed by a plug with an O-ring seal and covered by the bolted closure lid sealed with an O-ring. The cask must maintain a radioactivity release rate of not more than the regulatory limit for normal transport conditions and for hypothetical accident conditions, as required by the related regulations. The containment requirements of the cask are satisfied by maintaining a maximum air reference leak rate of $2.7{\times}10^{-4}ref.cm^3s^{-1}$ or a helium leak rate of $3.3{\times}10^{-4}cm^3s^{-1}$ for normal transport conditions and for hypothetical accident conditions.

The Role of Membranes and Intracellular Binding Proteins in Cytoplasmic Transport of Hydrophobic Molecules : Fatty Acid Binding Proteins and Long Chain Fatty Acids (세포내 소수성 물질 이동에서 막과 세포내 결합단백질의 역살 : 지방산 결합 단밸직과 장쇄 지방산)

  • 김혜경
    • Journal of Nutrition and Health
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    • v.30 no.6
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    • pp.658-668
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    • 1997
  • Path of a small hydrophobic molecule through the aqueous cytoplasma is not linear. Partition may favor membrane binding by several orders of magnitude : thus significant membrane association will markedly decrease the cytosolic transport rate. The presence of high concentration of soluble binding proteins for these hydrophobic molecules would compete with membrane association and thereby increase transport rate. For long chain fatty acid molecules, a family of cytosolic binding proteins collectively known as the fatty acid binding proteins(FABP), are thought to act as intracellular transport proteins. This paper examines the mechanism of transfer of fluorescent antyroyloxy-labeled fatty acids(AOFA) from purified FABPs to phosholipid membranes. With the exception of the liver FABP, AOFA is transferred from FABP by collisional interaction of the protein with a acceptor membrane. The rate of transfer increased markedly when membranes contain anionic phospholipids. This suggests that positively charged residues on the surface of the FABP may interact with the membranes. Neutralization of the surface lysine residues of adipocyte FABP decreased fatty acid transfer rate, and transfer was found to proceed via aqueous diffusion rather than collisional interaction. Site specific mutagenesis has further shown that the helix-turn-helix domain of the FABP is critical for interaction with anionic acceptor membranes. Thus cytosolic FABP may function in intracellular transport of fatty acid to decrease their membranes association as well as to target fatty acid to specific subcellular sites of utilization.

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A Study on the Heat and Moisture Transport Properties of Vapor-Permeable Waterproof Finished Fabrics for Sports Wear (스포츠웨어용 투습방수직물의 열·수분이동 특성에 관한 연구)

  • Son, Bu Hun;Kim, Jin-A;Kwon, Oh Kyung
    • Fashion & Textile Research Journal
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    • v.2 no.3
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    • pp.220-226
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    • 2000
  • This study was to determine the characteristics of vapor-permeable waterproof finished fabric by the coating method. 4 different kinds of coating fabrics (A : wet, porous, polyurethane, B : dry, no porous, polyurethane, C : shape memory polyurethane and D : dry, porous polyurethane) were used, which were developed recently With this sample, moisture transport rate ($40^{\circ}C$, 45%RH & $40^{\circ}C$, 95%RH), changes of coating side's shape by washing times, water repellency rate, contracted length, qmax, heat conductivity, heat keeping rate, heat keeping rate with cotton, heat keeping rate on humidity temperature and humidity within clothing etc. were checked. And it was done in a climate chamber under $20{\pm}2^{\circ}C$, $65{\pm}5%RH$. The results of this study were as follow; In the moisture vapor transmission of sample B and C increased on high temperature and high humidity while sample A and D decreased, on this condition. Qmax rate had high relation with ground fabric's surface properties and the order was A>C>D>B. Heat conductivity had high relation with thickness and surface properties. Heat keeping rates on sweat condition showed around half percents of heat keeping rates on normal condition, but had no relation with moisture vapor transport rate. Changes of the fabric's properties by washing times were different in accordance with the construction of fabrics and the coating resin. Sample C had tow heat keeping rate on the high temperature and humidity and high heat keeping rate on the low temperature and humidity Moisture transport rate of vapor-permeable waterproof finished fabrics had high relation with the properties of ground fabrics on low humidity condition, but on the high humidity condition, it was highly related with the properties of coating resin.

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