Partition coefficients defined

Chlorinated hydrocarbons and soils Koc = 0.63 Kow where Kow is the octanol-water partition coefficient defined as concentration of chemical in octanol divided by concentration of chemical in water at equilibrium. c... 

Using the above expressions for partition coefficients defined on the basis of weight fraction and volume fraction activity coefficients one avoids the difficulty of trying to define what exactly the molar volume of a polymer is. 

The data in Table I may be used to infer values of K, the solubilization equilibrium constant or partition coefficient defined by... 

Cdo and Mq are, respectively, the initial dmg concentration and undissolved dmg amount in donor compartment, while Kid, K21, K23, and K3,. are partition coefficients defined as follows ... 

The Ostwald solubility coefficient L is the gas-liquid partition coefficient defined as ... 

Koc can be estimated from Kow, the octanol-water partition coefficient (defined in Section 1.8.3). Table 3-5 shows some correlations between Koc and Kow for different classes of hydrophobic organic compounds. For further descriptions of the hydrophobic behavior of chemicals, the reader is referred to Schwarzenbach et al. (1993). 

R is the gas constant, Bn is the second virial coefficient for the probe, B13 is the mixed virial coefficient of the solute vapor and carrier gas, V is the partial molar volume of 1 at infinite dilution, P is the total pressure, and K is the equilibrium partition coefficient, defined as the ratio of concentration of solute in the stationary phase, q, to that in the gas phase, c, that is, K s q/c. 

Abraham et al. [64] characterized fullerene as adsorbent in gas-solid chromatography experiment. From the adsorption isotherms, gas-solid partition coefficients defined by Eq.(35), were calculated ... 

A convenient quantitative measure of uptake of a gaseous species by a liquid is the distribution coefficient (partition coefficient), defined as the ratio of the concentration of the respective species in the gas to that in the liquid. If the concentration of the species in the liquid remains low, the distribution coefficient often remains independent of concentration. This is known as Henry s law, and the constant distribution coefficient is called the Henry coefficient, Hx ... 

Methods. The diffusion experiments were performed at room temperature (23 C) utilizing a glass diffusion cell consisting of two compartments each with a volume of 175 ml. Each chamber was stirred at a constant rate to reduce boundary layer effects. Solute concentrations were monitored by h or C tracers, refractive index, or U.V. spectroscopy. Partition coefficients, defined as the ratio of the concentrations in the membrane and in the bulk aqueous phase were determined by solution depletion technique. 

In vapor adsorption on atmospheric particles, one often parametrizes the partitioning of a species between the gas and aerosol phase by introducing the partitioning coefficient defined as (Yamasaki et al. 1982 Pankow 1987)... 

To determine the preference of gases and organic components relative to water, gas and octanol we used equation (2.334). The partition coefficient defined from equations (2.300) and (2.319) is equal to 0.0416 Hj., and instead of coefficient can be used the octanol-water partition coefficient. ... 

M is the time-dependent undissolved (solid) drug amount present in the donor compartment S is the area available for permeation K, is the drug dissolution constant Cj is the drug solubility Vr is the receiver compartment volume Ai, A3, and A2 are, respectively, the thicknesses of the first and the second stagnant layers and the membrane Cjo and Mg are, respectively, the initial drug concentration and undissolved drug amount in donor compartment, while K2X, K22, and K r are partition coefficients defined as follows ... 

The effect of water-to-oil ratio By increasing the overall water-to-oil ratio in a given system, with everything else being kept constant, the alcohol content in each phase can either decrease or increase, depending on the alcohol distribution between hydrocarbon and water. If the partition coefficient, defined as the alcohol concentration in the oil phase divided by its concentration in the aqueous phase, is less than one, an increase in the WOR induces a decrease in the alcohol concentration in both phases. This is the case with isopropanol and the water-octane pair. This is pointed out elsewhere (6). 

The modelling of the partitioning of a chemical (pollutant) between water and lipid material (body fat) is usually done through a knowledge of the octanol-water partition coefficient, defined as ... 

In order to develop efficient post-polymerization and devolatilization operations, it is critical to know where the residual monomer and VOCs are located, that is, if they are mainly in the polymer particles or in the aqueous phase. Table 18.1 (in Section 18.4.2.1) summarizes the partition coefficients (defined as the ratio between the concentrations of monomer/VOC in the polymer particles and in the aqueous phase) measured for several monomers and VOCs in latexes. It can be seen that the monomers are mainly located in the polymer particles. On the other hand, water-soluble VOCs such as acetaldehyde and tert-butanol are mainly in the aqueous phase. It is worth pointing out that the partition coefficient decreases (that is, the monomer partitioning shifts toward the aqueous phase) as the average monomer concentration in the system decreases [56, 57]. 

There have been developments in understanding how the type of emulsion is related to the phase diagram of mixtures of oil + water + surfactant at equilibrium. These have come from the studies with microemulsions and as an example we take the case of a nonionic surfactant of the polyoxyethylene glycol ether type, C.E,.. Let us consider equilibrium systems of heptane and water (equal volumes) containing C12E5. At low [surfactant], monomer distributes between oil and water but heavily in favour of the oil. The partition coefficient defined as (molar concentration in heptane)/(molar concentration in water) increases from 130 at 10 C to —1500 at 50 C. Above a critical surfactant concentration, reached in both phases and designated (typically 5 X 10 m) and c Coji (typically... 

The second tricky point in the analysis comes from the partition coefficient H. I have casually described /fas a partition coefficient or a Henry s law coefficient, neglecting the complex units which can be involved. To illustrate these, we can compare three common forms of partition coefficients, defined at equilibrium... 

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