Volatile, volatiles

Volatilization — Volatilization is a physico-chemical phenomenon of particular interest to environmental managers as well as safety managers. It is the tendency of a material to transfer from a liquid phase (either pure or dissolved as in aqueous systems) to a gaseous phase (commonly air). The volatilization, or evaporation as it is more commonly called, is controlled by a number of factors, the most important of which are the vapor pressure of the material, temperature (vapor pressure increases with temperature), and air/material interfacial surface area, and the action of active mass transfer agents such as wind. 

Membership functions for the sets "very volatile," "volatile," and "slightly volatile."... 

Volatilization volatilization t,/2 = 5.5 h from a water column 1 m2 in cross section of depth 1 m (Mackay Leinonen 1975) ... 

Volatilization volatilization rate constant Iq = 0.03 d-1, microcosm exptl. (Wakeham et al. 1986). 

Volatilization volatilizes rapidly from water and land (Howard 1989). 

Volatilization Volatilization and biodegradation may be dominant transport and transformation processes for styrene in water calculated volatilization t,/2 = 3 h from a river 1-m deep with a current speed of 1.0 m/s and wind velocity of 3 m/s (Howard 1989) ... 

Pemety, 380 Volatil. Volatiles. Volatilisation Tout I Art [hermetique] consiste a volatiliser le fixe, et a fixer le volatil. ... 

Souchon et al. [41] found this process to be very efficient in the recovery of tomato volatiles both from the model system and from commercial tomato waste stream. They reported that using a 1.4-m membrane surface, a 20-L/h waste stream flow, and hexane as the extracting solvent, they would recover approximately 95% of the hydrophobic tomato volatiles. Volatile recovery is dependent upon the type of volatile being extracted and the extracting solvent. 

High Volatility. The problem preceding that of antiknock quality was concerned with fuels of low volatility. Volatility again became a problem in the early thirties as a result, in part, of extended thermal operations to make higher octane nmn-... 

Reduced Volatility—Volatility reductions would decrease gasoline volume and octane levels and produce excess light hydrocarbons. All gasoline producing facilities would, of course, have to be expanded to make up the volume loss, but greater increases in alkylation and isomerization capacity would be needed to raise octanes and utilize as much of the light hydrocarbons in gasoline as possible. 

Testing very volatile, volatile and semi-volatile organic chemical (WOC, VOC and SVOC) emissions from diverse product types to satisfy the differing needs of various national and international regulations and consumer or market interests, is a difficult thing to do. Emission testing is best carried out under conditions... 

As temperature increases, the vapor pressure of a liquid increases, as does the volatility. Volatility is a nonquantitative term that describes the tendency of a liquid to evaporate. More volatile liquids evaporate more readily than less volatile liquids. More volatile liquids have a higher vapor pressure than less volatile liquids. 

Volatilization volatilization t,/2 4.0 h from a model river 1 m deep flowing 1 m/s with a wind velocity of 3 m/s, based on estimated Henry s law constant (estimated-P/C, Lyman et al. 1982 quoted, Howard 1990). Photolysis will not undergo direct photolysis in the troposphere (quoted, Howard 1990). 

Buttery, R.G., Ling, J.C., Guadagni, D.G. (1969) Food volatiles. Volatilities of aldehydes, ketones, and esters in dilute water solution. J. Agric. Food Chem. 17, 385-389. 

Volatilization volatilization from water is negligible, calculated volatilization t,2 = 660 d (from 1 cm) and t,2 = 7.1 yr (from 10 cm) from soil (Howard 1991). 

Volatilization volatilization rate k < 0.01 kg ha-1 d 1 in a flooded rice field (Seiber et al. 1986 Seiber McChesney 1987 quoted, Seiber et al. 1989)... 

Volatilization volatilization t,2 = 2650 d from chemical below soil surface (Jury et al. 1990). 

Gas chromatography remains our most powerful separation technique probably because of this, it has become the most widely used of all analytical techniques. The major limitation to its application, of course, is that it is restricted to the separation of compounds which possess (or which can be derivitized to compounds which do possess) suitable vapor pressures, or "volatility . Volatility, however, is a necessary attribute of odorous compounds, and aroma exercises a profound influence on flavor. Hence, it is not surprising to find that gas chromatography has received a great deal of attention from the flavor chemist, and that many of the advances in gas chromatography have been made by those in the flavor field. 

For determination of Total Volatiles (Volatiles and Moisture), two methods can be recommended ... 

Volatilization volatilization and sorption t,/, 192 h from natural pond (Schauerte et al. 1982) ... 

Volatilization volatilization t,/, = 296 h from a model river was estimated using Henry s law constant for a model river of 1 m deep with 1 m/s current and a 3 m/s wind (Howard 1989)... 

Volatility. Volatility is defined as the propensity of a chemical to partition to air and migrate as a vapor. It is primarily a function of the vapor pressure of the compound. Vapor pressure is defined as the pressure of a chemical exerted by its vapor when in equilibrium with the solid or liquid form of... 

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