Synergism, hydrocarbon

When a deeper understanding of hydrocarbon synergism is attained, we can model the interactions by including the key reactions however, an interim approach has been adopted to scale hydrocarbon rate constants according to observed reactivities. Gas chromatographic measurements made by Scott Research Laboratories (52, 53) give the input information used in the analysis. Air samples were analyzed at a central basin station and at a northeastern basin station for two smog seasons. 

Direct conversion of methane to ethane and ethylene (C2 hydrocarbons) has a large implication towards the utilization of natural gas in the gas-based petrochemical and liquid fuels industries [ 1 ]. CO2 OCM process provides an alternative route to produce useful chemicals and materials where the process utilizes CO2 as the feedstock in an environmentally-benefiting chemical process. Carbon dioxide rather than oxygen seems to be an alternative oxidant as methyl radicals are induced in the presence of oxygen. Basicity, reducibility, and ability of catalyst to form oxygen vacancies are some of the physico-chemical criteria that are essential in designing a suitable catalyst for the CO2 OCM process [2]. The synergism between catalyst reducibility and basicity was reported to play an important role in the activation of the carbon dioxide and methane reaction [2]. 

Synergism of Phenol and Nitroxyl Radical Action on Hydrocarbon Oxidation... 

Hydrocarbon materials have several different characteristics that can be used to define their level of hazard. Since no one feature can adequately define the level of risk for a particular substance they should be evaluated as a synergism. It should also be realized that these characteristics have been tested under strict laboratory conditions and procedures that may alter when applied to industrial environments. The main characteristics of combustible hydrocarbon materials which are of high interest for fire and explosion influences are described below. 

Using the dendrimer route, it is possible to prepare supported catalysts not available via traditional routes. Dendrimer derived Pt-Au catalysts having compositions within the bulk miscibility gap can be prepared on several oxide supports. For all the supports studied, the bimetallic catalysts exhibited synergism with respect to mono- and cometallic catalysts for the CO oxidation and hydrocarbon NOx SCR reactions. The bimetallic Pt-Au catalysts also showed evidence of exchanging surface and subsurface atoms in response to strongly binding ligands such as CO. 

The conditions for synergism in surface tension reduction efficiency, mixed micelle formation, and Surface tension reduction effectiveness in aqueous solution have been derived mathematically together with the properties of the surfactant mixture at the point of maximum synergism. This treatment has been extended to liquid-liquid (aqueous solution/hydrocarbon) systems at low surfactant concentrations.) The effect of chemical structure and molecular environment on the value of B is demonstrated and discussed. 

During the past few years, the determination of the interfacial properties of binary mixtures of surfactants has been an area in which there has been considerable activity on the part of a number of investigators, both in industry and in academia. The Interest in this area stems from the fact that mixtures of two different types of surfactants often have interfacial properties that are better than those of the individual surfactants by themselves. For example, mixtures of two different surface-active components sometimes reduce the interfacial tension at the hydrocarbon/water interface to values far lower than that obtained with the individual surfactants, and certain mixtures of surfactants are better foaming agents than the individual components. For the purpose of this discussion we define synergism as existing in a system when a given property of the mixture can reach a more desirable value than that attainable by either surface-active component of the mixture by itself. 

Here, also we have extended (10) our treatment of synergism to 2-phase liquid systems and have derived equations that are completely analogous to those obtained for solutions in contact with air, when the nonaqueous phase is a hydrocarbon. The interaction parameter,... 

Organic disulfides and chloroorganic compounds in boundary lubrication conditions form iron sulfide (AHf = -1.04 eV), iron chloride (AHf = -3.54 eV), or iron bromide (AHf = -2.59 eV), which decrease wear and protect against seizure. Some chlorinated and brominated hydrocarbons in the presence of DBDS produce strong synergism in severe conditions involving lubrication in metal cutting (McCarroll et al., 1978 Mould at al., 1973 Plaza, 1989 Plaza et al., 1993 Sakuri etal., 1967). 

C. Hopf, A. von Keudell, W. Jacob Direct verification of the ion-neutral synergism during hydrocarbon film growth. J. Appl. Phys. 93, 3352 (2003)... 

Influence of Initial Composition. Synergism Between Hydrocarbons. The fact that free radicals produced in the photooxidation of one hydrocarbon can accelerate the attack on a coexistent hydrocarbon has been illustrated with experimental findings by Altshuller and Bufalini (45). Because of the limited understanding of detailed interactive mechanisms, we limited our multiple hydrocarbon investigation to a simple parametric study. Using an abbreviated version of the mechanism in Table I, we added a parallel series of oxidation steps. This scheme... 

Alcohol-dependent people with a physical tolerance are relatively tolerant of some other cerebral depressant drugs (hydrocarbon anaesthetics), but of course the synergism with these drugs still occurs. There is no significant acquired cross-tolerance with opioids. 

Table I shows the initial foam height, h°, and the foam half-life, rl/2, in the presence of different types of antifoams. The oil alone has low, foam-breaking efficiency (high initial foam height and half-life), the hydro-phobic particles alone are more effective, and the mixed type of agent is much better antifoam. The synergism between the oil and the hydrophobic solids is a general phenomenon. It generally occurs independently from the nature of the nonpolar oil (silicone or hydrocarbon oil) and the nature of the surfactant solution (anionic, cationic, or nonionic) (86, 88).

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