Evaporation rate factors influencing

Leaf gas exchange rates are highly dependent on local climatic factors influencing C02 diffusion and evaporation rates, especially temperature lapse rates. The dependency of gas-exchange parameters on local climatic factors and leaf anatomy may account for the wide variability in leaf stomatal responses and stable isotope composition over elevation transects found in different species and different regions. 

The reason for the differences in the pools formed by the spill in the unmitigated case can be explained by the curves for the evaporation rates of carbon disulfide. See Figure 7.4. First, consider the unmitigated D/5 case. In this case the maximum evaporation rate from the pool is reached approximately 1000 seconds after the start of the incident and is 8.5 kg/s, the largest of any of those considered. Factors that influenced this vaporization rate are listed below. 

The factors which decrease evaporation rate with time are (1) retreat of an initially continuous deposit into discrete small areas as it gets too thin to be coherent, (2) influence of adsorption or solution in the porous, oily, or wet surface, (3) retreat of a deposit, initially lying on the outer surface, into deeper capillary spaces. 

For example, an ink may contain a mixture of cyclohexanone with an evaporation rate of 0.2 and butoxyethanol (Butyl Cellosolve) with an evaporation rate of 0.07. Additional factors to take into account when choosing the solvents are the interaction of the solvent with the substrate, e.g., swelling of polymeric substrates enhances adhesion. Surface tension will influence print quality and dot gain with high surface tension solvents leading to smaller drops. 

The interaction between the ink and the substrate, both during and after deposition, strongly influences the quality of printing. Dynamic ink-substrate interactions such as ink drop impact, wetting, spreading, penetration, and solvent evaporation rate, as well as drying and coalescence of the ink particles on the substrate, are aU important factors. 

The solubility map does not indicate evaporation rate. Evaporation rate depends on many factors including solvent vapor pressure, hydrogen bonding, solvent-resin forces, solvent molecule shape, and polar forces among the constituents of the solution but solvent blends at the border of immiscibility evaporate more rapidly than blends of true solvents which fall at the center of the soluble area of a solubility map. This is die result of all the factors that influence evaporation. 

Some factors that influence the rate of evaporation of a solvent include temperature, flow of air over sample, vapor pressure of the solvent, latent heat, specific heat, and molecular weight (53). Galstaun (55) in 1950 reported a thorough study of the evaporation of some hydrocarbon solvents and developed equations for evaporation rates as related to several factors including temperature drop of liquid as it evaporates. Sletmoe (56) developed equations for the evaporation of neat solvent blends. The total rate of evaporation was proposed to be equal to the sum of the rates for the individual solvent components ... 

These two models illustrate how the properties of the compound influence the rate of evaporation from water under static conditions. Environmental conditions such as wind speed and turbulence in the water phase will have a marked influence on rates of evaporation that would reduce gradients and also reduce the width of the interfacial diffusion layers and systematic analysis of these effects have been discussed. Other variables will affect evaporation rates by controlling the actual concentration of the compound in solution. Suspended sediments and/or DOM would act in this manner. Weak acids and bases would only evaporate as the neutral species since the complementary anions or cations would be more water soluble and essentially have no vapor pressure. Consequently, environmental pH relative to pA values will be a consideration. It should be mentioned that compounds may distribute into the vapor phase by other processes than evaporation. Formation of aerosols, for example, can be a factor. 

A discussion of the factors influencing the evaporation of soil moisture is presented by Hide (1954). He states that the rate of evaporation of moisture from soil is influenced by ... 

Using the EISA method, the mesostructure produced is influenced by a number of factors. The evaporation rate of the volatile solvent is crucial to the establishment of an ordered mesostructure and may induce changes between ordered mesostructures. In general the surfactant structure (packing parameter) and the ratio of inorganic species to surfac-... 

The results presented above show that many factors influence the process of crystallization of a CT complex in a polymer matrix. Some of them, like temperature, solvent used, and composition of the polymer matrix, have been discussed in more detail, others, like the molecular weight of the polymer, and evaporation rate have only been mentioned. Investigations are still in progress. 

In the section on basic solvent characteristics it was shown that molecular weight and intermolecular forces are the two major factors determining the volatility of a solvent. Several properties were shown to relate to volatility such as boiling point, vapour pressure and evaporation rate. These properties will be discussed in more detail and attention paid to the influence of solvent mixing on these properties and to the solvent evaporation from polymer films. 

A complicating factor is the fact that the humidity of the air influences the evaporation rate of the water in the formulation (Figure 3.6) and hence the solvent balance during evaporation. A certain control of air humidity when applying this type of water-borne paints is therefore in general required [9]. 

Volatilization. The susceptibility of a herbicide to loss through volatilization has received much attention, due in part to the realization that herbicides in the vapor phase may be transported large distances from the point of application. Volatilization losses can be as high as 80—90% of the total applied herbicide within several days of application. The processes that control the amount of herbicide volatilized are the evaporation of the herbicide from the solution or soHd phase into the air, and dispersal and dilution of the resulting vapor into the atmosphere (250). These processes are influenced by many factors including herbicide application rate, wind velocity, temperature, soil moisture content, and the compound s sorption to soil organic and mineral surfaces. Properties of the herbicide that influence volatility include vapor pressure, water solubility, and chemical stmcture (251). 

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