Aliphatic hydrocarbons concentration factor

Several factors indicate that the amino acids detected in all of these carbonaceous chondrites are indigenous and that they must have originated abiotically. First, the presence of protein and non-protein amino acids, with approximately equal quantities of D and L enantiomers points to a nonbiological origin and precludes terrestrial contamination. In addition, the non-extractable fraction of the Murchison is significantly heavier in 13C than terrestrial samples. Finally, the relative abundances of some compounds detected resemble those of products formed in prebiotic synthesis experiments. The aliphatic hydrocarbons are randomly distributed in chain length, and the C2, C3, and C4 amino acids have the highest concentrations (i.e., the most easily synthesized amino acids with the least number of possible structures are most abundant) [4]. 

Citrus oils contain up to 95 % monoterpene hydrocarbons (usually (-t)-limonene, but others as well e.g., lemon oil also contains y-terpinene and /l-pinene). The important aroma-determining components of citrus oils are functionalized terpenes and aliphatic compounds (predominantly carbonyl compounds and esters), present only in relatively low concentrations [358, 358a]. Thus, several methods are employed to concentrate citrus oils on an industrial scale. The monoterpene hydrocarbon content is decreased by distillation, liquid-liquid partitioning between two immiscible solvents, or absorption on a carrier such as silica gel. The deterpenized concentrates are marketed under the name Citrus oil a-fold, depending on the concentration factor [358b]. 

Whatever the specific type, a valid question for all ordinary emulsions with or without surfactants is what is the maximum amount of the dispersed phase in the continuous phase when the former will still remain dispersed In other words, at what volume ratio does an inversion (i.e. OAV to W/O and the reverse) take place Emulsions for particle preparation are known to have been prepared where the volume ratio of the two phases can go up to near 1 1 [18]. In addition and contrast to this general idea about the relative contents of the two phases, one must also refer to the highly concentrated water-in-oil emulsions which can be prepared with a fluorinated surfactant and a fluorocarbon/hydrogenated surfactant (pronouncedly hydrophobic) and a hydrocarbon [19]. In these W/O emulsions, up to 98% w/w water is added, but inversion is never achieved. Highly concentrated W/O emulsions have also been described recently by Hakansson etal. [20] where the surfactant is of the alcohol ethoxylated type, the dispersed phase is aqueous in nature and the continuous phase, an aliphatic hydrocarbon. It has been indicated that such emulsions may contain more than 99% of the dispersed phase. These are, however, very special cases and do not demand further discussion here. Without going into specificities, let us look at the general factors that may influence inversion [3, 21, 22] ... 

Physical properties such as adhesion to metals tear resistance, abrasion resistance, resistance to diffusion of gas as well as resistance to dilute and concentrated acids, aliphatic and aromatic hydrocarbons, ketones, oil and gasoline, water absorption, oxidation, ozone, sunlight, heat aging, low temperature and flame of the common elastomers are documented in the literature.114 Rating of elastomers with respect to resistance to the factors cited above are in terms of outstanding, excellent, very good, good, fair and poor. 

Inverse emulsion polymerization is used for the preparation of polymers with ultrahigh molecular masses. For this type of polymerization, the expression dispersion polymerization is often used in the literature [410]. A concentrated monomer solution (about 40% monomer in water) is dispersed under intensive stirring in aliphatic or aromatic hydrocarbons in the presence of additives (emulsifiers, protective colloids). Polymerization can be initiated by either water-soluble or oil-soluble initiators [411-418]. The advantage of this process is based on the constant viscosity of the reaction mixture, as the increase of viscosity takes place only in the dispersed phase. By the use of additives (tensides), the dispersion inverts when the emulsion is stirred into water. Precipitation from the aqueous solution yields a polymer with ultrahigh molar mass. The quality of polymer made by inverse emulsion polymerization is influenced by the following factors (1) species and concentration of initiator, (2) species and concentration of additives (emulsifiers, protective colloids), (3) type of oil phase, and (4) particle size of the dispersed water phase. Because of the easy modification of all these parameters, much attention has been given in recent years to water-in-oil emulsion polymerization of AAm and MAAm. 

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