Factors Affecting Distribution

Chlorofluorocarbons have low dermal absorption characteristics. Absorption by the lungs is slow (based on data collected from animal studies). The main factor affecting distribution of chlorofluorocarbons in an individual is the amount of body fat. Chlorofluorocarbons are concentrated in the body fat and are slowly released into the blood at concentrations that do not present a risk of cardiac sensitization. 

Calvert, S. E. (1964). Factors affecting distribution of laminated diatomaceous sediments in the Gulf of California. Am. Assoc. Petroleum Geol. Mem. 3, 311-330. 

Cooper WJ, Shao C, Lean DRS, Gordon AS, Scully FE (1994) Factors affecting distribution of hydrogen peroxide in surface waters. In Baker LA (ed) Environmental chemistry of lakes and reservoirs. Adv Chem Series 237, American Chemical Society, Washington DC, p 393... 

Monomer compositional drifts may also occur due to preferential solution of the styrene in the mbber phase or solution of the acrylonitrile in the aqueous phase (72). In emulsion systems, mbber particle size may also influence graft stmcture so that the number of graft chains per unit of mbber particle surface area tends to remain constant (73). Factors affecting the distribution (eg, core-sheU vs "wart-like" morphologies) of the grafted copolymer on the mbber particle surface have been studied in emulsion systems (74). Effects due to preferential solvation of the initiator by the polybutadiene have been described (75,76). 

Adsorption Kinetics. In zeoHte adsorption processes the adsorbates migrate into the zeoHte crystals. First, transport must occur between crystals contained in a compact or peUet, and second, diffusion must occur within the crystals. Diffusion coefficients are measured by various methods, including the measurement of adsorption rates and the deterniination of jump times as derived from nmr results. Factors affecting kinetics and diffusion include channel geometry and dimensions molecular size, shape, and polarity zeoHte cation distribution and charge temperature adsorbate concentration impurity molecules and crystal-surface defects. 

Scale-Up Principles. Key factors affecting scale-up of reactor performance are nature of reaction zones, specific reaction rates, and mass- and heat-transport rates to and from reaction sites. Where considerable uncertainties exist or large quantities of products are needed for market evaluations, intermediate-sized demonstration units between pilot and industrial plants are usehil. Matching overall fluid flow characteristics within the reactor might determine the operative criteria. Ideally, the smaller reactor acts as a volume segment of the larger one. Elow distributions are not markedly influenced by... 

After absorption, a chemical compound enters the circulation, which transfers it to all parts of the body. After this phase, the most important factor affecting the distribution is the passage of the compound through biological membranes. From the point of view of the distribution of a chemical compound, the organism can be divided into three different compartments (1) the plasma compartment (2) the intercellular compartment and (3) the intracellular compartment. In all these compartments, a chemical compound can be bound to biological macromolecules. The proportion of bound and unbound (free) chemical compound depends on the characteristics of both the chemical... 

Petanate, A.M. and Glatz, C.E., 1983. Isoelectric precipitation of soy protein. I. Factors affecting particle size distributions. II. Kinetics of protein aggregate growth and breakage. Biotechnology and Bioengineering, 25, 3049. 

The full picture of the factors affecting copolymer sequence distribution and their relative importance still needs lo be filled in. 

Nonstoichiometry of the oxides can be due to a number of reasons, such as hydration,159 incomplete oxidation,158 and the generation of defects at interfaces.157 An important factor affecting the chemical composition of the oxides is the incorporation of electrolyte species into the growing alumina. There have even been suggestions to use this for impurity doping of oxides and modifying their properties.161 Various kinds of anion distributions and mechanisms of anion incorporation and their influence on oxide properties have been reported. The problems attracting attention are ... 

Hardiman R.T., Jacoby B., Banin A. Factors affecting the distribution of cadmium, copper and lead and their effect upon yield and zinc content in bush beans (Phaseolus vulgaris L.). Plant Soil 1984a 81 17-27. 

Product distributions obtained on esterification of nucleosides and nucleotides under basic conditions throw further light on factors affecting selective reactivity. p-Toluenesulfonylation of adenosine 5 -monophosphate in aqueous alkali yielded exclusively (in 54-61% yield) the 2 -p-toluenesulfonate.107 Lack of reaction at HO-3 was attributed either to formation of a phosphoric p-toluenesulfonic anhydride, which sterically protected this hydroxyl group, or to the higher acidity of HO-2. It has been shown that the acidic site (with pKa 12.5) in adenosine is associated with the presence of both HO-2 and HO-3, as replacement of either of these by hydrogen, or of HO-2 by methoxyl, results in loss of this acidity.108 Inductive effects, or the sta-... 

The effect of temperature on distribution ratios has already been mentioned on page 91. Although the separation proceeds more quickly at elevated temperatures, resolution suffers because of increased rates of diffusion. However, in adsorption TLC only small increases in Rt values are observed even with a 20°C rise. Strict temperature control is not necessary if samples and standards are run at the same time, although large fluctuations should be avoided. The quality of the thin-layer materials, and in particular the presence of impurities in them, determine the extent to which partition, adsorption, ion-exchange and exclusion participate in the sorption process. These factors affect Rr values in an unpredictable manner. Thin layers should be of uniform thickness, between 0.2 and 0.3 mm with thinner layers, local variations in thickness can result in appreciable variations in Rf values. 

We have seen in the preceding chapters that a considerable amount of both experimental and theoretical evidence points to the existence of a transition layer at the boundary of two phases—in other words, of a layer in which the concentration of the phases is different from that in the bulk. It will, therefore, be advisable to consider quite generally what factors affect the concentration — for instance, the distribution of a solute in a solvent. 

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