Organic surface, conversion into

In a similar way, the reaction of surface methoxy species with cyclohexane on zeolite CHs-Y was investigated (263). At temperatures T>493K. surface methoxy species most probably act as precursors of carbene intermediates, which can undergo the sp insertion into C-H single bonds. In the absence of water and other organic species, conversion of methoxy groups alone to alkanes and aromatics was observed at temperatures r>523K (Scheme 17) (263). This observation indicates a... 

Surface preparation of the core foil was originally simple acid etching. As the importance of durable surface treatments became known, a more stable chemical conversion coating with an organic primer-like coating became standard. Still, water ingression into honeycomb structure continued to cause the occasional... 

The biological cycle of arsenic in the surface ocean involves the uptake of arsenate by plankton, the conversion of arsenate to a number of as yet unidentified organic compounds, and the release of arsenite and methylated species into the seawater. Biological demethylation of the methyl-arsenicals and the oxidation of arsenite by as yet... 

Organic solvents enhance emitted intensities mainly because of a higher resultant flame temperature (water has a cooling effect), a more rapid rate of feed into the flame because of the generally lower viscosity, and the formation of smaller droplets in the aerosol because of reduced surface tension. The resultant enhancement of spectral line intensity may be 3-to over 100-fold. Conversely, the presence of salts, acids and other dissolved species will depress the intensity of emission from the analyte and underlines the need for careful matching of samples and standards. 

Werner complex See coordination compound. ver-nor, kam,picks ) wet aahing org chem The conversion of an organic compound into ash (decomposition) by treating the compound with nitric or sulfuric acid. wet ash-ii) wettability chem The ability of any solid surface to be wetted when in contact with a liquid that is, the surface tension of the liquid is reduced so that the liquid spreads over the surface.. wed-a bil-od-e ... 

Before we discuss the chemistry of the stratosphere in detail, let us first briefly consider how chemicals emitted at the earth s surface are transported into the stratosphere and, conversely, how stratospheric species are transported into the troposphere. This issue is important as it determines which species end up in the stratosphere as we shall see, it is only those that survive for a sufficiently long time in the troposphere that are transported into the stratosphere. Thus, reactive organics (larger than CH4) from the troposphere do not survive to reach the stratosphere in appreciable quantities. Similarly, transport from the stratosphere to the troposphere is the major mechanism for removal of the products of the reactions of anthropogenic species that occur in the upper atmosphere. In addition, some 03 is injected into the troposphere, which is a natural source upon which anthropogenic production of 03 is imposed (see Chapter 16). 

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