Subject aliphatic hydrocarbons

Schoch A process for making acetylene by subjecting aliphatic hydrocarbons to a silent electric discharge. Developed by E. P. Schoch at the University of Texas. 

Tabak and colleagues111 found most compounds in the group to be subject to significant degradation under experimental aerobic conditions. At least ten of the compounds are subject to biodegradation under anaerobic conditions. Britton112 discusses microbial degradation of aliphatic hydrocarbons in more detail. 

Moreover, sp3 C-H bond activation is one of the most significant subjects because aliphatic hydrocarbons including methane exist abundantly in nature. 

The nitration of moderate to high molecular weight alkane substrates results in very complex product mixtures. Consequently, these reactions are only of industrial importance if the mixture of nitroalkane products is separable by distillation. Polynitroalkanes can be observed from the nitration of moderate to high molecular weight alkane substrates with nitrogen dioxide. The nitration of aliphatic hydrocarbons has been the subject of several reviews. 

The mechanism of action for diesel fuels is not well characterized due to the complexity of its petroleum hydrocarbon mixture. The presence of additives that improve fuel combustion or prevent microbial growth may contribute to toxicity. Based on research conducted with individual components of diesel fuels, the primary mechanism of action for central nervous system (CNS) depression from diesel fuel is the reversible, physical interaction of the aromatic and aliphatic hydrocarbons with cell membranes. Renal toxicity is possibly attributed to oxidative metabolites of some of the aromatic constituents. Eye and skin injury are attributable to direct irritant action and the high lipid solubility that may dissolve protective skin oils and allow penetration into the skin tissue. The dermal carcinogenesis observed in rodents subjected to chronic dermal exposure to diesel may be attributed to the genotoxic activity of PAHs and the promoting activity of repeated dermal injury. 

Besides acting as an electron scavenger, the precise role of O2 has been elusive for some time and continues to be a subject of some debate. In several studies on the photocatalysed oxidation of aliphatic hydrocarbons, alcohols, ketones, carboxylic acids and aldehydes, Heller (1995) concluded that molecular O2, and not the photogenerated hole or OH radical, is the primary oxidising agent. As evidence, data were given that photooxidation of n-octane films on water produced only traces of octanols. 

Aliphatic hydrocarbons are not the subject of extensive photophysical investigation in spite of unique character of a electron excitation involved. The effect of polarization on the lowest excited states have been theoretically investigated by... 

The metallocene is added to the supported MAO as a solution in toluene or aliphatic hydrocarbon. Subsequently subjecting the mixture to microwaves has been claimed to fix the metal component on the support and reduce reactor fouling (adhesion of polymer to reactor surfaces). The metallocene can also be dry-blended with the support, avoiding solubilization of the finished catalyst. ... 

We may think that corrosion problems are exclusive to metallic materials, or at least to materials characterized by electronic conductivity, and this is probably true as regards electrochemical corrosion. However, for example, rubber is subject to SCC in environments containing ozone, polystyrene is subject to SCC in environments containing aliphatic hydrocarbons, high-density polyethylene may be subject to SCC (e.g., in benzene), and ice is subject to cracking in environments containing alcohol. 

The temperature resistance of the polyarylates lies between polysulfone and polycarbonate. The polymer is flame retardant and shows good toughness and UV resistance. Polyarylates are transparent and have good electrical properties. The abrasion resistance of polyarylates is superior to polycarbonate. In addition, the polymer shows a very high recovery from deformation. However, the material is subject to environmental stress cracking, particularly in the presence of aromatic and aliphatic hydrocarbons. 

Early in the development of organic chemistry, organic compounds were arbitrarily classified as aliphatic or aromatic. Aliphatic compounds have open-chain structure. In addition to aliphatic compounds, there was a large number of compounds which were obtained from natural sources e.g., resins, balsams, aromatic oils etc., all of which had a pleasant odour. These compounds had higher percentage of carbon content than the corresponding aliphatic hydrocarbons and most of the simple compounds contained atleast six carbon atoms. These compounds were known as aromatic compounds. Further more, when these aromatic compounds were subjected to various methods of treatment, they often produced benzene or derivatives of benzene. 

This is intended for locations subject to intermittent contact with aliphatic hydrocarbons such as mineral spirits, lower alcohols, glycols, etc. Such contact can be the result of splash, spillage, or fumes. 

These thermoplastic polymers are generally characterized by their toughness in respect to resistance to heat and UV exposure. Of importance also are their transparency, warp resistance, excellent flexural recovery, high elastic limits, and good electrical and mechanical properties, including outstanding creep resistance. They have as well excellent radiation and oxidation resistance. Their thermal expansion rate is close to Uiat of metal. This amorphous material is subject to environmental stress cracking, however, particularly in the presence of aromatic or aliphatic hydrocarbons. 

Particulates are another source of respiratory irritation when inhaled. In urban environments, diesel exhaust particles (DEP) and fly ash residue from power plant oil combustion are the main contributors of respirable particulates of less than 10 pm diameter (PMIO). These contain mixtures of lipophiles and hydrophiles including various metals, acid salts, aliphatic hydrocarbons, PAHs, quinones, nitroaromatic hydrocarbons, and aldehydes [19]. Diesel combustion particulates contain large surface areas that can adsorb large quantities of organic compounds and deliver these to respiratory tract tissue. Other inhaled particulates can adhere to lung surfaces and adsorb and bond with other vapors that are inhaled, thereby increasing their toxicides. PM2.5 particulates (those with diameters of less than 2.5 pm) which reach the lower respiratory tract as far as the alveoli are more toxic than PMIO particulates of the same composition [20]. The subject of fine particle toxicity (nanotoxicity) is explored in greater detail in Chapter 36. 

The saturated hydrocarbon moieties give lipids an aliphatic character, and thus hydro-phobic properties, which limit their loss from artefacts by water leaching. However, they are subject to chemical and microbiological alterations since they have a limited number of reactive sites, they are relatively less susceptible to structural modification and degradation than polysaccharides, proteins and nucleotides. 

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