• 미생물학회지
• /
• 제28권3호
• /
• pp.278-282
• /
• 1990

Diffusion and partition of progesterone into the polyacrylamide gel was examined. Diffusion coefficient of progesterone decreased down to an asymptotic value as the concentration of the organic solvents in the diffusing medium increased. However the partition coefficient diminished steadily. Crosslinking density in the gel didn't affected the diffusion coefficient considerably but lowered the partition coefficient due to the contraction of pore volume of the gel. Progesterone showed higher diffusion coefficient as well as partition coefficient in the polyurethane than in the polyacrylamide gel, which seems to be ascribed to the difference in hydrophobicity, pore volume and pore size of the polymer matrix.

• Environmental Analysis Health and Toxicology
• /
• 제16권4호
• /
• pp.189-196
• /
• 2001

Octanol/water partition coefficients of 52 chemicals were calculated using RP-HPLC estimation method and predicted by computer program, PCHEM. The result showed relationship between literature values and RP-HPLC observed values (relative coefficient r$^2$＝0.916), but the relationship of PCHEM values with literature values was lower than RP-HPLC value (relative coefficient r$^2$＝0.795). The average difference in partition coefficient between the RP-HPLC method and flask-shaking method was log Kow＝0.54, while the average difference between the values predicted form the computer program and flask- shaking method was log Kow = 0.36 Compared to octanol/water partition coefficients by 3 methods (Flask-shaking, RP-HPLC, computer prediction), the octanol/water partition coefficient values based on the flask-shaking method were very similar to the literature values, while the octanol/water partition coefficient values by RP-HPLC method without to consider the dead time, and computer prediction values did not significantly differ with the literature values.

• Bulletin of the Korean Chemical Society
• /
• 제28권7호
• /
• pp.1183-1186
• /
• 2007

A shake-flask method was used to determine the n-octanol/water partition coefficients of sulfamethazine, sulfadimethoxine, sulfamethoxydiazine, sulfamonomethoxine, sulfamethoxazole, sulfaquinoxaline and sulfachloropyrazine from (298.15 to 333.15) K. The results showed that the n-octanol/water partition coefficient of each sulfonamide decreased with the increase of temperature. Based on the fluid phase equilibrium theory, the thermodynamic relationship of n-octanol/water partition coefficient depending on the temperature is proposed, and the changes of enthalpy, entropy, and the Gibbs free energy function for sulfonamides partitioning in n-octanol/ water are determined, respectively. Sulfonamides molecules partitioning in n-octanol/water is mainly an enthalpy driving process, during which the order degrees of system increased. The temperature effect coefficient of n-octanol/water partition coefficient is discussed. The results show that its magnitude is the same as that of values in the literature.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 1996년도 경북지부 결성 및 추계학술발표회 논문집
• /
• pp.50-53
• /
• 1996

This paper reports the experimental results for the determination of the overall partition coefficient of VOCs in unsaturated soil, A chromatographic method was used for the determination of gaseous partition coefficients to natural soil under various water content conditions. The equilibrium vapor pressure of water over saturated salt solution was used to fix the relative humidity of the air and control the water content of the soil systems. The transport behavior was studied for dichloromethane, trichloroethane and dichlorobenzene pollutants, with log octanol-water partition coefficients(log $K_{ow}$ ) which range from 1.25 to 3.39, or water to soil partitioning which varies by 135 times; water solubility constants which vary by 3 times; and vapor pressures which range from 1 to 362 torr. Water content of the soil had a pronounced effect on the effective partition coefficient(between gas and soil + water stationary phase) as well as on the effective dispersion coefficient.

• 한국식품과학회지
• /
• 제19권2호
• /
• pp.140-145
• /
• 1987

폴리에틸렌 글라이콜-덱스트란 흔합수용액이 형성하는 수용액 2상계에서 표면 소수성의 크기를 알고 있는 표준 단백질들의 분획계수를 관찰하였다. 또한 폴리에틸렌 글라이콜(PEG)에 palmitate를 부착시킨PEG-P를 첨가함으로써 상층부의 소수성을 증가 시켰을때 단백질들의 분획계수 변화를 조사하였다. PEG/dextran 2상계에서 단백질의 분획계수는 딘백질의 유효 소수성에 관계없이 2상계의 용적비가 동일한 조건에서 PEG와 dextran의 농도가 함께 증가함에 따라 분획계도 증가하였다. 그러나 PEG에 78%친환도를 가지는 PEG-P를 소량 첨가하여 만든 2상계에서는 유효 소수법이 큰 bovine serum albumin과 $\beta-lactoglobulin$의 분획계수가 10배 이상 증가하였고. 유효 소수성이작은 ovalbumin은 큰 변화를 보이지 않았다. 이러한 분획계수의 급격한 중가는 PEG-P의 첨가량이 아주 낮은 2% 수준일 때 나타났으며 그 이상 침가시에는 모든 단백질이 공히 10% 첨가될때까지 완만히 증가하는 경향을 나타내었다.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
• /
• pp.115-118
• /
• 2006

The partitioning tracer method has been studied as an alternative method for characterizing aquifers contaminated by nonaqueous phase liquids (NAPLs). Accurate partition coefficients of tracers partitioning between NAPL and water are needed to improve the reliability of the partitioning tracer method. In this research, partition coefficients of alcohol tracers partitioning between benzene, toluene, ethylbenzene, and xylenes (BTEX) compounds and water are estimated from using the approach of equivalent alkane carbon number (EACN). General agreement was observed in between the measured and estimated partition coefficients. Based on these results we can verify that the EACN approach is suitable for estimating the partition coefficient.

• 한국환경과학회지
• /
• 제5권2호
• /
• pp.243-252
• /
• 1996

미국 New Jersey주에서 채취한 4종류의 토양사료를 이용하여 토양에서 카드뮴 흡착과 치환성양이온의 탈착에 미치는 pH와 유기뮬함령의 영향을 조사하였다. 카드뮴용액으로는 $1\times10^{-5}$M,$1\times10^{-4}$M, $2\times10^{-4}$M, $3\times10^{-4}$M ${Cd(NO_3)}_2$ 용액을 사용하였고, 흡착평형시의 토양용액의 pH는 4.0,5.5, 7.0, 8.5로 맞추었다. 카드뮴흡착등온선의 기울기는 토양용액의 pH가 증가하였으며, partition coefficient($K_4$)도 용액의 pH가 증가할수록 크게 증가하였다. 또한 Langmuir흡착방정식에 의하여 구한 카드뮴대흡착량도 용액의 pH가 높은 경구가 낮은 경우보다 훨씬 많았다. $1\times10^{-4}$M ${Cd(NO_3)}_2$ 용액을 사용한 실험에서 유기물함량과 partition coefficient사이의 correltion coefficient($r^2$)는 용액의 pH가 4.0인 경우의 0.3027에서 pH가 8.5인 경우의 0.9964로 증가하였으며, $2\times10^{-4}$M ${Cd(NO_3)}_2$ 용액을 사용한 실험에서는 pH가 4.0인 경우의 0.2093에서 pH가 8.5인 경우의 0.9657로 증가하였다. 칼슘과 마그네슘의 탈착량은 토양용액의 pH가 증가할수롱, 흡착된 카드뮴의 양이 증가할수록 감소하였다.

• 대한기계학회논문집B
• /
• 제21권7호
• /
• pp.948-961
• /
• 1997

The effects of intake port eccentricity and a partition between the two intake ports on the incylinder swirl characteristics in a 4 valve diesel engine having the two intake ports, one is a helical intake port and the other is a tangential intake port, were investigated by using the impulse swirl meter(ISM) in a steady flow test rig. Mean flow coefficient ( $C_{f(mean)}$, swirl ratio ( $R_{s}$) and the mass flowrate through the two intake ports with and without intake port partition were measured. The results showed that the characteristics of in-cylinder swirl ratio formed by a 4-valve cylinder head were largely affected by valve eccentricity ratio ( $N_{y}$) and the existence of an intake port partition between the two intake ports. Mean flow coefficient ( $C_{f(mean)}$) increases and swirl ratio ( $R_{s}$) decreases in case of being the partition between the two intake ports. And also the mass flowrate through the tangential intake port is 19.0% and 7.7% more than that of the helical intake port in case of the two intake ports with and without partition respectively.ively.

• 한국지하수토양환경학회:학술대회논문집
• /
• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
• /
• pp.20-28
• /
• 2006

Partitioning tracer tests were conducted to quantify the saturation degree of diesel and water in unsaturated soil, respectively. The use of partitioning tracers that partition into diesel, water, and air (i.e., three-phase partitioning), is in attractive alternative to traditional coring and analysis method. These gaseous partition tracers not global warming gas like CFC's are Butane, Acetylene, Ethylene, Methylene chloride, and Methane. The glass column packed with sandy soil was prepared, in which a three-phase system of air, water, and diesel was maintained. Conservative and partition gas tracers were injected into the columns and detected easily using a single GC detector(FID). For each tracer, a method of moments was used to estimate partition coefficient between water, diesel. and the air, respectively. The results from the column studies showed that the diesel/air tracer partition coefficient ranged from 8.2 to 868 and 9.2 for water/air. Saturation degree of diesel and water in the column, predicted by the partition coefficients obtained from tests, was underestimated up to 66% and 23% respectively.

• 한국미생물·생명공학회지
• /
• 제20권2호
• /
• pp.190-195
• /
• 1992

Polythylene glycol/dextran 수성 2단계에서 polyethylene glycol의분자량과 농도가 증가할수록 체적비는 증가하고 분배계수는 감소하였다. 또한 dextran의 분자량이 증가할 수록 체적비는 감소하고 분배계수는 증가하였다. 한편 dextran의 농도가 증가할수록 체적비와 분배계수는 감소하였다.