• Title, Summary, Keyword: partition coefficient

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Gas-Particle Partitioning of PCBs in Ambient Air, Yokohama Japan (일본 요코하마 대기 중 PCBs의 가스-입자 분배)

  • Kim Kyoung-Soo
    • Journal of Korean Society for Atmospheric Environment
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    • v.21 no.3
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    • pp.285-293
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    • 2005
  • This study was aimed at estimation of gas-particle partitioning of polychlorinated biphenyls (PCBs) in ambient air. The samples were collected at urban site in Japan from March 2002 to January 2003. The concentration of total PCBs (from 4 CB to 10 CB) and TEQ (Toxic equivalent) ranged from 62 to $247\;pg/m^3$ and from 2 to $14\;fgTEQ/m^3 $, respectively. The average contribution $(\%)$ of gas phase to total PCBs concentration was above $80\%$, which suggests that in the atmosphere PCBs predominantly existed in the gas phase. The weak correlations between total PCBs concentration and temperature was found. However this result was due to a typhoon during summer and raining during sampling period. The gas-particle partition coefficient (Kp) was obtained as a function of temperature. The partition ratio of gaseous and particulate phase PCBs can be estimated for an arbitrary temperature. The plot of gas/particle partition coefficient (log Kp) vs. sub-cooled liquid vapor pressure $(log\;P_L)$ had reasonable correlations for individual samples but the slope varied among the samples (coefficients of determination for log Kp versus log $P_L$ plot were> 0.76 $(p<0.0001)$, except for 3 samples). As a result, the variations in the slope among the sampling period may be due to change of temperature, raining during sampling period and wind in this study.

Numerical Simulation of Fluorescent Whitening Agents (DAS1) in Tokyo Bay (동경만 형광표백제 성분물질(DAS1)의 거동 특성 시뮬레이션)

  • Kim, Dong-Myung
    • Journal of Environmental Science International
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    • v.20 no.4
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    • pp.519-525
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    • 2011
  • A three-dimensional ecological model(EMT-3D) was applied to DAS1 in Tokyo Bay. The simulated results of DAS1 were in good agreement with the observed values. The result of sensitivity analysis showed that photolysis coefficient and extinction coefficient were important factor for dissolved DAS1, and photolysis coefficient, extinction and POC partition coefficient for PAHs in particulate organic matter. Mass balance of DAS1 in Tokyo Bay was calculated by using the simulated results of EMT-3D.

Apparent pKa and Partition Coefficient of Tranylcypromine (Tranylcypromine의 겉보기 해리항수(解離恒數) 및 분배계수(分配係數))

  • Kang, Gun-Il;Chung, Soon-Young
    • YAKHAK HOEJI
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    • v.28 no.5
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    • pp.293-297
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    • 1984
  • The pKa' of tranylcypromine was determined by potentiometric titration and ultraviolet spectrophotometric method and found to be 8.08 and 8.15, respectively. The Papp of tranylcypromine between n-heptane and aqueous buffer solution was measured to be 0.90 at pH 7.48 and 4.50 for Pm. The pKa' of tranylcypromine obtained by means of the partition method was 8.13.

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Nickel and cobalt partition coefficients in pyrite-pyrrhotite as geothermometer. (지질온도계로써 황철석과 자류철석내의 Ni와 Co의 분배 계수)

  • Yoo, Jae-Shin
    • Journal of the Speleological Society of Korea
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    • v.24 no.25
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    • pp.69-80
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    • 1991
  • 광화시기가 같은 유화광물중에서 상접하는 황철석과 자류철석 내에 함유되어 있는 코발트와 니켈의 함량을 정량분석하여 이들 원소들의 Partition Coefficients로부터 Bezmen method를 이용하여 광물의 생성온도를 구하였다(217~395$^{\circ}$). 지질 연대가 같은 유화광물의 생성온도는 동시기에 생성된 인접한 석영내의 유체포유물의 filling temperature와 거의 일치한다(255~395$^{\circ}$). 따라서 이들 광산내의 광물의 생성온도는 지질온도계로 사용이 가능하며 광물의 생성환경을 규명하는데도 유용할 것이다.

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Preformulation Study of Aspalatone, a New Antithrombotic Agent (새로운 항혈전 약물인 아스팔라톤의 전처방화 연구)

  • 곽혜선;전인구
    • Biomolecules & Therapeutics
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    • v.8 no.4
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    • pp.332-337
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    • 2000
  • Physicochemical properties of aspalatone (acetylsalicylic acid maltol ester, AM), which has been recently found to have an antithrombotic effect, were studied in terms of solubility, dissolution, partition coefficient (Pc) and stability. The solubility of AM at 37$^{\circ}C$ was about 1.2 mg/ml and the P$_{c}$ value for n-octanol/water and chloroform/water was 11.4 and 382.6, respectively. Dissolution rates of AM at pH 1.2 and 6.8 were more than 80% within 30 min. The degradation of AM followed apparent first-order kinetics, and was dependent on temperature, pH and ionic strength. From the pH-rate profile, the optimal pH was found to be at around 4.0. Half-lives at pH 1.2 and 6.8 were 33.5 and 44.4 hr, respectively. The degradation rate of AM at pH 1.2 was somewhat faster than that of aspirin, but at pH 7.0, the degradation rate of AM was slower than that of aspirin.n.

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Effect of ion-pair complexation with bile acids on the bilary excretion and systemic distribution of organic drugs

  • Shim, Chang-Koo
    • Archives of Pharmacal Research
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    • v.9 no.1
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    • pp.49-54
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    • 1986
  • Effect of sodium taurodeoxycholate (TDC) infused intravenously on the pharmacokinetics of methylene blue (MB) was studied in the rat to investigate the role of ion-pair complexation in the body on drug elimination and disposition. Distribution volume (Vd) of MB was increased significantly (p< 0.05) by TDC infusion. Considering together with the fact that apparent partition coefficient (APC) of MB between phosphate buffer (pH 7.4) and n-octanol was increased markedly by TDC, the increase in Vd seemed to be the result of decreased polarity of MB by ion-pair formation with TDC. But total body clearance (CLt) and biliary excretion clearance (CLbil) of MB were not increased significantly by TDC.

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Development of a Supported Emulsion Liquid Membrane System for Propionic Acid Separation in a Microgravity Environment

  • Li, Jin;Hu, Shih-Yao B.;Wiencek, John M.
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.6 no.6
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    • pp.426-432
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    • 2001
  • Perstractive fermentation is a good way to increase the productivity of bioreactors. Us-ing Propionibacteria as the model system, the feasibility of using supported emulsion liquid mem-brane(SELM) fro perstractive fermentation is assessed in this study. Five industrial solvents were considered as the solvent for perparing the SELM. The more polar a solvent, is the higher the par-tition coefficeint However, toxicity of a solvent also increases with its polarity. CO-1055(indus-trial decanol/octanol blend)has the highest partition coefficient toward propionic acid among the solvents that has no molecular toxicity toward Propionibacteria, A preliminary extraction study was conducted using tetradecane as solvent in a hydrophobic hollow fiber contactor. The results confirmed that SELM eliminates the equilibrium limitation of conventional liquid-liquid extrac-tion and allows the use of a non-toxic solvent with low partition coefficient.

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Pattern Partitioning and Decision Method in the Semiconductor Chip Marking Inspection (반도체 부품 마크 미세 결함 검사를 위한 패턴 영역 분할 및 인식 방법)

  • Zhang, Yuting;Lee, Jung-Seob;Joo, Hyo-Nam;Kim, Joon-Seek
    • Journal of Institute of Control, Robotics and Systems
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    • v.16 no.9
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    • pp.913-917
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    • 2010
  • To inspect the defects of printed markings on the surface of IC package, the OCV (Optical Character Verification) method based on NCC (Normalized Correlation Coefficient) pattern matching is widely used. In order to detect the micro pattern defects appearing on the small portion of the markings, a Partitioned NCC pattern matching method was proposed to overcome the limitation of the NCC pattern matching. In this method, the reference pattern is first partitioned into several blocks and the NCC values are computed and are combined in these small partitioned blocks, rather than just using the NCC value for the whole reference pattern. In this paper, we proposed a method to decide the proper number of partition blocks and a method to inspect and combine the NCC values of each partitioned block to identify the defective markings.

Refining of Silicon by Fractional Melting Process (Fractional Melting에 의한 Si 정련에 관한 연구)

  • Kim, Kwi-Wook;Yoon, Woo-Young
    • Journal of Korea Foundry Society
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    • v.17 no.6
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    • pp.598-607
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    • 1997
  • Fractional melting process involves heating an alloy within its liquid-solid region simultaneously ejecting liquid from the solid-liquid mixture. The extent of the purification obtained is comparable to that obtained in multi-pass zone refining. The new fractional melting process in which centrifugal force was used for separating the liquid from the mixture has been developed and applied to the purification of the metallic grade. Refining ratio depends on partition ratio, cake wetness and diffusion in the solid, and it was controlled by various processing parameters such as rotating speed and heating rate. The new parameter called "refining partition coefficient" has been suggested to estimate the effects of processing variables on the refining ratio. Because major impurities in MG-silicon such as Fe, Al, Ni have a low segregation coefficient, good purification effect is expected. The results of refining MG-silicon(98%) showed that 3N-Si was obtained in refined solid of 50% of the original sample.

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Influence of Temperature and Affinity of Disperse Dye on Dyeing of PET(Polyethylene Terephthalate) Microfiber (PET 초극세사 염색에서 분산염료의 친화력과 온도 의존성)

  • Lee, Hun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.9
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    • pp.532-540
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    • 2019
  • PET microfibers with various diameters (0.5, 0.2, 0.06, and 0.01 dpf) were dyed with a dispersed dye (C.I. Disperse Blue 56) at various temperatures. The dyeing process was conducted under infinite dyebath conditions at constant temperatures. The effects of the dyeing temperature and diameter on the partition coefficient, affinity, and diffusion coefficient of disperse dyes were studied. The curve of isotherms was fitted well to Nernst-type model in a large range of initial dye concentrations. At the same temperature, the partition coefficient and affinity decreased with increasing sample diameter due to the increase in surface area. At all deniers, the partition coefficient and affinity decreased with increasing temperature because the dyeing process is an exothermic reaction. In addition, the decrease in radius of the sample gives rise to a decrease in the heat of dyeing. The fine diameter of the sample resulted in an increased surface area but decreased space between the microfibers. Consequently, decreasing the diameter of the microfibers leads to a decrease in the diffusion coefficient. At the same diameter, the diffusion coefficient increased with increasing temperature because of rapid dye movement and the large free volume of the sample inside. In addition, thermal dependence of the diffusion coefficient increased when the diameter of the sample increased.