• Title/Summary/Keyword: Normal transport

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Fluid Flow and Solute Transport in a Discrete Fracture Network Model with Nonlinear Hydromechanical Effect (비선형 hydromechanic 효과를 고려한 이산 균열망 모형에서의 유체흐름과 오염물질 이송에 관한 수치모의 실험)

  • Jeong, U-Chang
    • Journal of Korea Water Resources Association
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    • v.31 no.3
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    • pp.347-360
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    • 1998
  • Numerical simulations for fluid flow and solute transport in a fracture rock masses are performed by using a transient flow model, which is based on the three-dimensional stochastic and discrete fracture network model (DFN model) and is coupled hydraulic model with mechanical model. In the numerical simulations of the solute transport, we used to the particle following algorithm which is similar to an advective biased random walk. The purpose of this study is to predict the response of the tracer test between two deep bore holes (GPK1 and GPK2) implanted at Soultz sous Foret in France, in the context of the geothermal researches.l The data sets used are obtained from in situcirculating experiments during 1995. As the result of the transport simulation, the mean transit time for the non reactive particles is about 5 days between two bore holes.

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Thermal Analysis for Dry Transport of a Shipping Cask (수송용기의 건식수송에 대한 열해석)

  • Lee, J.C.;Kang, H.Y.;Yoon, J.H.;Chung, S.H.;Kwack, E.H.
    • Nuclear Engineering and Technology
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    • v.25 no.2
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    • pp.248-254
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    • 1993
  • The purpose of this study is to evaluate the thermal safety for dry transport of a shipping cask. Analysis condition was based on an ambient temperature of 38$^{\circ}C$ for normal heat condition. The cask was designed to carry 4PWR spent fuel assemblies with a burnup of 38,000 MWD/MTU and 3 years of cooling time. Thermal analysis was carried out by using the COBRA-SFS code. The fuel cavity was considered to be filled with air, nitrogen or helium gas for dry transport. The results of analysis showed that the maximum temperatures of fuel rod cladding in air and helium cavity would be 277$^{\circ}C$ and 226$^{\circ}C$, respectively, for 3 years of cooling time. These values were less than the specified temperature to maintain the thermal integrity of fuel assembly for dry transport.

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Roles of Sperm Proteins

  • Cho, Chung-Hee
    • 대한생식의학회:학술대회논문집
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    • 2001.11a
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    • pp.57-62
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    • 2001
  • One of recent advances of mammalian fertilization is the understanding of the molecular basis of fertilization. Several proteins localized in sperm nucleus or on sperm surface are necessary for the fertilization process. Protamines, sperm nuclear proteins, are required for normal sperm function that leads to fertilization. Fertilin and cyritestin are sperm surface proteins and essential for sperm-egg binding. Fertilin is also required for sperm transport in the female reproductive tracts. Metalloproteses on sperm plasma membrane are found to play a role in sperm-egg fusion. The functional analysis of these proteins provides a new insight into the molecular mechanisms underlying mammalian fertilization and male fertility.

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In Vitro Uptake of Salicylate by Human Red Blood Cells

  • Kim, Chone-Kook
    • Archives of Pharmacal Research
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    • v.2 no.1
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    • pp.65-70
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    • 1979
  • Distribution and binding properties of sodium salicylate the human red blood cells were studied under various experimental conditions. The effect of tonicity and hemolysis on the steady state level of the drug within the human red blood cells were accounted for in this study. When the washed cells were suspended in normal saline solution, the drug was so rapidly permeated into red cells. Since the pH of the system forces nearly complete ionization of the drug, ionic diffusion through aqueous pores is thought to be the mode of salicylate transport. Human red cell binding capacity and association constant for salicylate were estimated. This work supports the view that the red cells act asan important reservior of salicylate.

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Effect of Chain Matching between Hydrocarbon and Fatty Acid on High Pressure Rheology

  • Ohno, N.;Mukai, R.;Rahman, Md.Z.;Shibata, K.
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2002.10b
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    • pp.83-84
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    • 2002
  • For estimation of chain-matching phenomena between normal paraffin as a solvent and straight-chain fatty acid as an additive, the density measurement of n-dodecane, n-tetradecane and n-hexadecane were carried out at oil temperature 313K and pressure up to 1.3 GPa. Their solidification pressure were easily determined by the appearance of molecular crystal, abrupt volumetric contraction and generation of heat of solidification and showed minima under the matching condition. The bulk modulus K of molecular crystal was evaluated using phase diagram. The bulk modulus showed maxima under the each matching condition. The chain matching effect on the bulk modulus beyond the scope of the interfacial phenomena are confirmed.

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Effect of Water Flux on the Determination of Membrane Permeability Using Single-pass Perfusion

  • Oh, Doo-Man
    • Journal of Pharmaceutical Investigation
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    • v.24 no.3
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    • pp.19-25
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    • 1994
  • The single-pass perfusion technique was employed in order to investigate the effect of water flux from the rat jejunum in the normal experimental conditions. Our results suggested that water flux below ${\pm}0.75%/cm$ of jejunal length was considered normal. Water flux was $-0.131\;{\pm}\;0.311%/cm$ of jejunal length in a citrate buffer and should be corrected in order to determine the permeabilities of the compounds. Perfusion rate up to 0.5 ml/min had no effects on the permeability of ampicillin. Neither the effective permeabilities nor the wall permeabilities of aminopenicillins were influenced by water flux during experiments in rats.

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A Numerical Study on Normal and Abnormal Combustion in Hydrogen Premixture (수소 예혼합기의 정상 및 이상연소에 관한 수치해석)

  • 손채훈;정석호
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.8
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    • pp.1989-1998
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    • 1995
  • Characteristics of the flame propagation for normal and abnormal combustion in hydrogen premixture in a cylindrical constant-volume combustion chamber are studied numerically. A detailed hydrogen oxidation kinetic mechanism, mixture transport properties and a model describing spark ignition process are used. The calculated pressure-time history of the stable deflagration wave propagation agrees well with the experiment. The ignition of the premixture in the unburned gas, initiated by the hot spot, causes a transition from deflagration to detonation under some initial temperature and pressure. Under the initial conditions with high temperature and pressure, excessive ignition energy initiates a strong blast wave and a detonation wave that follows. The chemical reaction in the detonation wave is much more vigorous than that in the deflagration wave and the peak pressure in the detonation wave is much higher than the equilibrium value.

A study on the improvement of sound absorption coefficient of an honeycomb panel by the core resonance (코어공명을 이용한 허니콤패널의 흡음율 개선에 관한 연구)

  • Yu, Y.H.
    • Journal of Power System Engineering
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    • v.12 no.4
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    • pp.46-51
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    • 2008
  • Honeycomb panel has a constructive advantage because it is constructed with a honeycomb core, so it has relatively higher strength ratio to weight. Therefore honeycomb panel has been used as the light weight panels in the high-speed railway technology and high-speed ship like as cruise yachts. Also it has been used in the aircraft and aerospace industry as a structural panel because light weight structure is indispensible in that field of industry. Recently, the honeycomb panel is embossed in the viewpoints of high oil prices as the lightweight panel of the transport machine, however the sound insulation capacity of the honeycomb panel is poorer than those of uniform and another sandwich panels. In this paper a method to improving the sound absorption coefficient of a honeycomb panel Is studied by using the Helmholtz resonator. The sound absorption coefficients for some kinds of honeycomb cores are demonstrated by the normal incident absorption coefficient method.

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A study on the mechanism for reduction of lead-induced toxicity in nervous system by aloe vera (Aloe vera의 연 유도성 신경계 독성 저감 기전에 관한 연구)

  • 정명규;곽영규
    • Journal of Environmental Health Sciences
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    • v.22 no.3
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    • pp.8-16
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    • 1996
  • Effects of water extract of aloe vera on lead-induced neurotoxicity were investigated in sciatic nerve isolated from rat. The mechanism on toxicity reduction by measuring activities of axonal enzymes, metabolism of myo-inositol in nerve, lead concentration in several organs and so on were further examimed. In the lead-treated rats, the transport rate of axonal enzyme, such as acetyl cholinesterase and choline acetyltransferase, was reduced by from 50% to 30% respectively. Reduction in myo-inositol concentration and $Na^+/K^+$ ATPase activity were also observed in sciatic nerve from lead-treated rat. However, the aloe extract administration significantly eliminated the impairment and maintained myo-inositol concentration to about 85% of normal level. Also aloe extract promoted the excretion rate of lead which is accumulated in blood, sciatic nerve and kidney. These results suggest that lead-induced neurotoxicity was significantly reduced by administration of aloe extract and the mechanism might be partly increase in kidney excretion rate of lead and parity normalization of $Na^+/K^+$ ATPase activity which is critical factor in order to keep nerve maintaining normal myo-inositol level.

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Gate-tunable Supercurrent in Graphene-based Josephson Junction (그래핀 조셉슨 접합에서 초전류의 게이트 전압 의존성)

  • Jeong, D.;Lee, G.H.;Doh, Y.J.;Lee, H.J.
    • Progress in Superconductivity
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    • v.13 no.1
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    • pp.47-51
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    • 2011
  • Mono-atomic-layer graphene is an interesting system for studying the relativistic carrier transport arising from a linear energy-momentum dispersion relation. An easy control of the carrier density in graphene by applying an external gate field makes the system even more useful. In this study, we measured the Josephson current in a device consisting of mono-layer graphene sheet sandwiched between two closely spaced (~300 nm) aluminum superconducting electrodes. Gate dependence of the supercurrent in graphene Josephson junction follows the gate dependence of the normal-state conductance. The gate-tunable and relatively large supercurrent in a graphene Josephson junction would facilitate our understanding on the weak-link behavior in a superconducting-normal metal-superconducting (SNS) type Josephson junction.