Saturation component

The oligomerization of cardanol with boron trifluoride etharate as the initiator was studied in detail by Antony et al. [171]. The reaction conditions were optimized by using gel permeation chromatography as 140°C with an initiator concentration of 1%. GPC data indicate conversion of all monoene, diene, and triene components into polymer except the saturated component, indicating participation of all the unsaturated components in polymerization. It is possible that the initiation of po-... 

Each oil-dispersant combination shows a unique threshold or onset of dispersion [589]. A statistic analysis showed that the principal factors involved are the oil composition, dispersant formulation, sea surface turbulence, and dispersant quantity [588]. The composition of the oil is very important. The effectiveness of the dispersant formulation correlates strongly with the amount of the saturate components in the oil. The other components of the oil (i.e., asphaltenes, resins, or polar substances and aromatic fractions) show a negative correlation with the dispersant effectiveness. The viscosity of the oil is determined by the composition of the oil. Therefore viscosity and composition are responsible for the effectiveness of a dispersant. The dispersant composition is significant and interacts with the oil composition. Sea turbulence strongly affects dispersant effectiveness. The effectiveness rises with increasing turbulence to a maximal value. The effectiveness for commercial dispersants is a Gaussian distribution around a certain salinity value. 

Susceptibility to n-alkane degradation is an inverse function of chain length. Branched alkanes are less susceptible than straight-chain n-alkanes, and the most resilient saturated components are the pristine and phytane isoprenoids (Wang et al. 1998). 

In some favorable cases, the age of fluid in an aquifer system may be estimated from measurements of a radiogenic 4He concentration ([4He]) and a flux (JM(.) of radiogenic 4He into a fluid system with the use of a relation t = [4He]/./He. The observed 4He in fluid generally consists of radiogenic 4He accumulated in the fluid and an initially air-saturated component. However, the latter component is generally much smaller than the former and can be safely neglected. Hence,... 

The initial rate of uptake also increases as the external concentration is raised (Figure 2). At high concentrations further increments in the extracellular concentration produce much smaller increases in the accumulation rate, indicating the involvement of a saturable component in the uptake process. At low concentrations the data conform to the classical equation of Michaelis-Menten, giving a straight line when plotted according to the Lineweaver-Burk method. The rising slope of... 

The methyl esters of the long-chain fatty acids can be subjected to exactly the same examination as outlined earlier in this chapter. In the usual case, these fatty acid esters will be composed largely of unsaturated (olefinic) linkages with little or no saturated components. This follows the pattern noted before for the substituents located at the C-2 position in other phosphoglycerides. A quantitative analysis of these fatty acids will show that there is 1 mol per mol of lipid phosphorus. The lysoalkenyletherphosphatidylcholine can then be studied further. 

The extent of pheromone degradation under field conditions was investigated with a microencapsulated formulation containing a saturated hydrocarbon and acetate (octadecane and tetradecyl acetate (14 Ac)), the corresponding monounsaturated hydrocarbon and acetate ((Z)-4-octadecene and (Z)-9-tetradecenyl acetate (Z9-14 Ac)) and a diunsaturated acetate ((Z,S )-9,ll-tetradeca-dienyl acetate (ZE9,ll-14 Ac)), chosen so that all the components had similar volatilities. On exposure to sunlight, loss of the diene was more rapid than loss of the monounsaturated components which in turn disappeared faster than the saturated components (Fig. 1). All components disappeared at a similar, slower rate when shielded from direct sunlight. 

The occurrence of fewer secondary cracking reactions in the MR is confirmed by the significant deviations in the LPG olefmicity. This is the ratio of unsaturated to saturated components in the LPG fraction and is a typical indicator for secondary hydrogen-transfer reactions. The definition of this ratio is given in equation 1. Figure 5 shows this... 

In general, with decreasing hydrocarbon partial pressure, unsaturated components such as acetylene, ethylene, propylene, and butadiene increase whereas BTX, pyrolysis fuel oil, and saturated components such as methane, ethane, and propane decrease. Low hydrocarbon partial pressure can be attained either by high steam dilution or by low absolute pressure in the cracking coil, which is determined by furnace outlet pressure and pressure drop in the cracking coil. For each specific case there is an optimum steam dilution. Reduction of steam dilution influences yields, utilities, running times and, in the case of a new ethylene plant, of course, investment costs—but in different ways, either positive or negative. Thus, an optimization has to be carried out to identify the most economic steam dilution. 

Residence Time. The influence of residence time on yields is similar to that of hydrocarbon partial pressure, but smaller. In principle, unsaturated components increase slightly with shorter residence time, depending on the cracking severity. At the same time, saturated components and pyrolysis fuel oil (PFO) decrease. The quality of pyrolysis fuel oil also is influenced by residence time. For constant P E, the ratio of carbon to hydrogen in PFO becomes smaller with decreasing residence time, which has a positive effect on coking tendency besides other parameters. 

Saponification refers to alkaline hydrolysis of fats and oils to give glycerol and the alkali metal salt of a long chain fatty acid (a soap). In this experiment saponification of olive oil is accomplished in a few minutes by use of a solvent permitting operation at 160°C. Of the five acids found in olive oil, listed in Table 1, three are unsaturated and two are saturated. Oleic acid and linoleic acid are considerably lower melting and more soluble in organic solvents than the saturated components, and when a solution of the... 

Hexane or light petroleum ether, chloroform, benzene, and toluene are most often the major components of the mobile phase, whereas smaller proportions of diethyl ether, acetone, methanol, ethanol, or acetic acid are added as modifiers. Chloroform-methanol and hexane-acetone mobile phases reportedly provide very good separations. Often more than one development is required for reliable resolution. The separation starts with the most polar phase and proceeds, after drying between runs, with mobile phases of gradually decreasing polarity. Highly unsaturated components are resolved first and do not move further with subsequent developments when the more saturated components are separated. 

The long-term fate of dispersed oil is not known, although it probably degrades to some extent as it consists primarily of saturate components. Some of the dispersed oil may also rise and form another surface slick or it may become associated with sediment and be precipitated to the bottom. 

White oils These are highly refined oils which consist entirely of saturated components, all aromatics being removed by treatment with fuming sulphuric acid or by selective hydrogenation. Their name reflects the facts that they are virtually colourless and the most highly refined. White oils are used in medical products and the food industry. 

Solvent extraction replaced acid treatment as the method for improving oxidative stability and viscosity/temperature characteristics of base oils. The solvent selectively dissolves the undesired aromatic components, the extract, leaving the desirable saturated components, especially alkanes, as a separate phase, the raffinate. Choice of solvent is determined by a number of factors, which are as follows ... 

They found other peculiarities when studying the transport of L-tryptophan in human freshly sampled red cells uptake could be resolved into linear and saturable components but upon infection or storage of red cells the linear component was substantially increased whereas the Kt and maximum velocity (Vmax) remained constant. (They also contended that the presence of parasitized red cells altered the permselectivity of uninfected red cells.) Further, the changes in the permselectivity of the P. falciparum-infected red cells was unaffected by p-chloromercuribenzoate (PCMB) and cytochalasin B, inhibitors for glucose transport, as well as DIDS and DNDS for anion transport, but was inhibited by phloretin, a modifier of the membrane dipole potential shown to block a variety of mediated and non-mediated transport mechanisms. Phloretin also inhibited the in vitro growth of P. falciparum. This work is reviewed in Ginsburg and Kirk, 1998. 

Ancelin, M. L. and Vial, H. J. (1992) Saturable and non-saturable components of choline transport in Plasmodium-infected mammalian erythrocytes possible role of experimental conditions. Biochem. J. 283 619-621. 

Glycerol absorption in H. diminuta occurs by passive diffusion at high concentrations (>0.5mM) and by a carrier-mediated process at lower concentrations. At lower concentrations, absorption of this lipid precursor is non-linear, dependent on temperature and pH, and competitively inhibited by glycerol and a-glycerophosphate. The existence of two distinct carriers for this molecule is suggested by studies which show that only about half the saturable component in H. diminuta is Na -sensitive and inhibitable by 1,2-propandiol (2). 

---