• Title/Summary/Keyword: facilitated transport

검색결과 135건 처리시간 0.025초

동역학적 흡착 관계식을 이용한 다공 매질에서의 유동세균에 의한 유기성 오염물의 가속이송 예측 모델 (Modeling Bacteria Facilitated Contaminant Transport in Porous Media with Kinetic Adsorption Relationships)

  • 김승현
    • 대한지하수환경학회지
    • /
    • 제2권1호
    • /
    • pp.22-29
    • /
    • 1995
  • 유동 세균 입자는 지체계수를 감소시키므로써 지하수에서 소수성 오염물의 이동을 촉진시킨다. 그 크기와 표면의 적당한 물리화학적 조건으로 인하여 세균은 효율적인 오염물의 운반자가 될 수 있다. 이러한 운반자가 있을 때, 그 계는 액상, 입상, 그리고 고상의 3 상으로 해석되어야한다. 오염물은 각 상에 모두, 혹은 그 중의 일부에 존재할 수 도 있다. 본 연구에서는 세균이 있는 경우, 생화학적으로 분해 가능한 유기성 오염물의 다공매질에서의 거동을 물질수지에 기초하여 수학적 모델로 묘사한다. 세균의 액상과 고상사이의 물질 전이 및 오염물의 액상과 입상사이의 물질 전이는 동역학적 관계식으로 나타냈다. 모델 결과를 일반화하기 위하여 무차원화를 수행했고, 그 해를 구하여 세균에 의한 오염물의 가속이송 효과를 알 수 있었다. 모델 결과는 문헌상의 실험결과와 비교되었다. 모델 결과로부터 오염물은 그 계의 Damkohler I 수가 10 이상일 경우 국지 평형 가정을 할 수 있었으며, 세균의 성장율과 주입 농도 등이 오염물의 청소에 아주 중요한 요소임을 알 수 있었다.

  • PDF

평형 모델을 이용한 다공매질에서의 유동 세균에 의한 유기성 오염물의 가속이송 (Modeling Bacteria Facilitated Contaminant Transport in Porous Media with Equilibrium Adsorption Relationships)

  • 신항식;김승현
    • 대한지하수환경학회지
    • /
    • 제2권1호
    • /
    • pp.14-21
    • /
    • 1995
  • 지하수에 콜로이드가 있을 경우 지체계수 감소로인한 오염물의 가속이송이 일어난다. 세균은 콜로이드 크기이며, 비중이 물과 비슷하고. 또 특유의 표면조건으로 인하여 오염물을 가속이송시킬 수 있다. 유동 세균이 지하수에 있으면 그 system 은 액상, 고상, 그리고 입상의 3 상 (phase) 으로 해석되어야 한다. 본 연구에서는 물질수지에 기초한 수학적 모델을 개발하여 다공매질에서의 오염물의 이동을 예측했다. 세균과 오염물의 각 상사이의 분배는 평형분배 모델을 이용했다. 모델결과를 일반화하기 위하여 무차원화 기법이 사용되었다. 모델의 해는 수치해법이 사용되었고, 문헌상의 실험결과와 비교되었다. 유동 세균이 존재하므로써 오염물이 가속이송되었고, 오염물을 섭취하므로써 그 농도를 낮출 수 있었다.

  • PDF

세포막 물질수송계의 조절에 의한 유기수은의 세포독성 변화에 대한 연구 (Changes on the Methylmercury-induced Cytotoxicity by Control of Cell Membrane Transport System)

  • 염정호;고대하;김준연;김남송
    • 한국환경보건학회지
    • /
    • 제26권4호
    • /
    • pp.88-96
    • /
    • 2000
  • The aim of the current study was to evaluate the transport system in EMT-6 cell for the uptake of the methylmercury(MeHg). Several inhibitors ere used to test used to test which potential transport system might be involoved in MeHg uptake. Probenecid was used to test the organic transport system, valinomycin for testing the effect of the membrane potential, cytochalasin B for testing the facilitated diffusive D-glucose transport system and colchicine for testing the microtubule system. Ouabain for evaluating active transport system, 4',4-diisothiocyano-2',2-stilbenedisulfonic acid(DIDS) the Cl- ion transport system and verapamil for the $Ca^{2+}$ transprot system. Significantly, MeHg decreased the synthesis of nitric oxcide(NO) and intracellular ATP in ENT-6 cells. In the condition of ouabain containing with MeHg decreased the production of NO and intracelluar ATP. In the treatment of inhibitors, ouabain showed protective effect against cytotoxicity of MeHg but ather inhibitors not showed protective effects. The protective effects of ouabain against the cytotoxicity of MeHg deoended on the concentration of added ouabain to the culture medium for MET-6 cells. These result showed that the uptake of MeHg might be involved in the active transport system. Active transports system seems to share similarities with the transport systems for the uptake of MeHg when using MeHg and MeHg-glutathione complex.x.

  • PDF

촉진수송 및 태양전지용 분리막 (Polymer Electrolytes and their Application to Solar Cells and Separation Membranes)

  • 강용수
    • 한국막학회:학술대회논문집
    • /
    • 한국막학회 2004년도 첨단 분리막 연구동향
    • /
    • pp.13-35
    • /
    • 2004
  • Metal Complexes in Macromolecules Applications of Polymer Electrolyte Membranes Facilitated Transport in Solid State Roles of Electrolytes in Solar Cells - Electrolytes :ㆍI- and $I_3$-conductor ㆍelectron barrier or hole conductor ㆍelectrochemical redox reaction media ㆍinterfacial contactor for dye, $TiO_2$ and electrode ㆍmechanical separator (omitted)

  • PDF

Novel Composite Membranes Comprising Silver Salts Physically Dispersed in Poly(ethylene-co-propylene) for the Separation of Propylene/Propane

  • Kim, Jong-Hak;Min, Byoung-Ryul;Kim, Yong-Woo;Kang, Sang-Wook;Won, Jong-Ok;Kang, Yong-Soo
    • Macromolecular Research
    • /
    • 제15권4호
    • /
    • pp.343-347
    • /
    • 2007
  • Novel composite membranes, which delivered high separation performance for propylene/propane mixtures, were developed by coating inert poly(ethylene-co-propylene) rubber (EPR) onto a porous polyester substrate, followed by the physical distribution of $AgBF_4$. Scanning electron microscopy-wavelength dispersive spectrometer (SEM-WDS) revealed that silver salts were uniformly distributed in the EPR layer. The physical dispersion of the silver salts in the inert polymer matrix, without specific interaction, was characterized by FT-IR and FT-Raman spectroscopy. The high separation performance was presumed to stem from the in-situ dissolution of crystalline silver ionic aggregates into free silver ions, which acted as an active propylene carrier within a propylene environment, leading to facilitated propylene transport through the membranes. The membranes were functional at all silver loading levels, exhibiting an unusually low threshold carrier concentration (less than 0.06 of silver weight fraction). The separation properties of these membranes, i.e. the mixed gas selectivity of propylene/propane ${\sim}55$ and mixed gas permeance ${\sim}7$ GPU, were stable for several days.

Effect of Salt on Facilitated Propylene Transport through Crosslinked PVA/Silver Salt Complex Membranes

  • Kim, Jong-Hak;Min, Byoung-Ryul;Lee, Ki-Bong;Kang, Yong-Soo
    • Korean Membrane Journal
    • /
    • 제8권1호
    • /
    • pp.43-49
    • /
    • 2006
  • Complex membranes consisting of silver salt ($AgBF_4,\;AgCF_3SO_3,\;AgSbF_6,\;AgNO_3$) and poly(vinyl alcohol) (PVA) or crosslinked PVA (CPVA) were prepared and tested for the separation of propylene/propane mixtures. For the tested membranes, the complex membranes containing $AgBF_4$ exhibited the highest separation properties, i.e., approximately 20 GPU ($1 GPU=10^{-6}cm^3 (STP)/(cm^2 sec cmHg)$) and 100 of selectivity at 0.2 of silver mole fraction. The CPVA membranes containing silver salt always showed higher selectivity than PVA membranes, presenting silver ions coordinated to -CHO are more effective than those to -OH groups. The threshold silver concentration of CPVA membranes was lower than that of PVA membranes, which might be due to stronger interaction of silver ions with -CHO than that with -OH. The composition at which the selectivity is the highest did not significantly depend on the crosslinking, but did on the kind of silver salt.

Selective Coordination of Silver Ions to Poly(styrene-b-(ethylene-co-butylene)-b-styrene) and its Influence on Morphology and Facilitated Olefin Transport

  • Lee, Dong-Hoon;Kang, Yong-Soo;Kim, Jong-Hak;Kang, Sang-Wook
    • Macromolecular Research
    • /
    • 제16권8호
    • /
    • pp.676-681
    • /
    • 2008
  • The $\pi$-complex membranes of poly(styrene-b-(ethylene-co-butylene)-b-styrene) (SEBS) of two silver salts of $AgBF_4$ and $AgCF_3SO_3$ were prepared and tested for the separation of the propylene/propane mixtures. The Fourier-transform infrared (FT-IR) spectra of these complexes showed that the silver salts were dissolved in SEBS up to a silver mole fraction of 0.14, due to $\pi$-complexation between the aromatic C=C bonds of styrene blocks and silver ions. Above this solubility limit, ion pairs and high-order ionic aggregates began to form, so that silver salts were distributed unselectively in both the EB and PS blocks. The domain size of the PS blocks was enlarged up to this critical concentration with increasing silver concentration without structural transitions, as confirmed by small angle x-ray scattering (SAXS). These structural properties of the SEBS/silver salt complexes may explain the lower separation properties for propylene/propane mixtures compared to poly(styrene-b-butadiene-b-styrene)(SBS)/silver salt complex membranes.

유기 태양전지 개발 동향 및 전망 (Development Trends and Perspectives of Organic Solar Cells)

  • 강문성;강용수
    • 공업화학
    • /
    • 제16권2호
    • /
    • pp.159-168
    • /
    • 2005
  • 염료감응 태양전지(dye-sensitized solar cells, DSCs)는 높은 광전효율과 값싼 제조비용의 매력을 가지고 있어 지난 10년간 활발히 연구되어왔다. 염료감응 태양전지의 에너지 전환은 광자를 흡수한 여기 상태 염료감응제의 나노결정 산화티타늄 반도체 전도대로의 전자 주입에 의해 발생된다. 이러한 염료감응 태양전지는 미래의 에너지 문제를 해결할 수 있는 유망한 청정재생 에너지원으로 기대된다. 본 총설에서는 염료감응 태양전지의 최근 개발 동향과 향후 전망에 대해 조사하였다.

Separation and Concentration of L-Phenylalanine using a Supported Liquid Membrane

  • Jeong Woo Choi;Kyu
    • Biotechnology and Bioprocess Engineering:BBE
    • /
    • 제3권1호
    • /
    • pp.24-31
    • /
    • 1998
  • The separation and concentration of L-phenylalanine (L-Phe) using a supported liquid membrane (SLM) is investigated. A cation complex agent, di-2-ethylhexyl phosphoric acid (D2EHPA), is used as a carrier in the SLM with n-Heptane as a solvent. The reaction order and equilibrium constant in the formation reaction of L-phe-carrier complex are obtained from the extraction experiment. A mathematical model for a carrier mediated counter transport process is proposed to estimate the diffusion coefficient of L-phe-carrier complexly in the liquid membrant. Permeation experiments of L-phe using a SLM are performed under various operating conditions and optimum conditions for the transport of L-phe are obtained. Concentration of L-phe in the strip phase against its concentration is observed. Transport rate of glucose through liquid membrane is less than that of L-phe in the competitive transport of L-phe and glucose. And the existence of glucose reduced the transport rate of L-phe. The performance of separation with continuous strip phase is increased due to the dilution effect in the strip phase.

  • PDF