Saturation fraction definition

It is thus tempting to define the first saturated layer as being one monolayer, and this often done, causing some confiision. One therefore also often uses tenns like saturated monolayer to indicate such a single adsorbate layer that has reached its maximal two-dimensional density. Sometimes, however, the word saturated is omitted from this definition, resulting m a different notion of monolayer and coverage. One way to reduce possible confiision is to use, for contrast with the saturated monolayer, the tenn fractional monolayer for the tenn that refers to the substrate unit cell rather than the adsorbate size as the criterion for the monolayer density. 

A saturated aqueous solution in contact with an excess of a definite solid phase at a given temperature will maintain constant humidity in an enclosed space. Table 11.4 gives a number of salts suitable for this purpose. The aqueous tension (vapor pressure, in millimeters of Hg) of a solution at a given temperature is found by multiplying the decimal fraction of the humidity by the aqueous tension at 100 percent humidity for the specific temperature. For example, the aqueous tension of a saturated solution of NaCl at 20°C is 0.757 X 17.54 = 13.28 mmHg and at 80°C it is 0.764 X 355.1 = 271.3 mmHg. 

The line = 0 can be considered as a borderline for applicability of the basic model, in which the Gaussian curvature is always negative. Recall that in the basic model the oil-water interface is saturated by the surfactant molecules by construction of the model. Hence, for equal oil and water volume fractions the Gaussian curvature must be negative, by the definition of the model. 

If equilibrium has not been reached between a mixture of components, the condition is referred to as partial saturation. At partial saturation the gas mixture obeys real gas laws. There are several ways to express the concentration of a vapor in a mixture of gases. Most often, weight or mole fraction is used. Other definitions are relative saturation (relative humidity), molal saturation (molal humidity) and absolute saturation (absolute humidity). 

Figure 8.3. Fatty acid composition of anhydrous milk fat and selected milk fat fractions grouped in short chain, medium chain and long chain saturated fatty acids and unsaturated fatty acids. For definition of fractions, see Figure 8.1. The numbers in the bars give the percentage of the group of fatty acids. Data from Deffense (1987, Table 3).

The percolation model suggests that it may not be necessary to have a rigid geometry and definite pathway for conduction, as implied by the proton-wire model of membrane transport (Nagle and Mille, 1981). For proton pumps the fluctuating random percolation networks would serve for diffusion of the ion across the water-poor protein surface, to where the active site would apply a vectorial kick. In this view the special nonrandom structure of the active site would be limited in size to a dimension commensurate with that found for active sites of proteins such as enzymes. Control is possible conduction could be switched on or off by the addition or subtraction of a few elements, shifting the fractional occupancy up or down across the percolation threshold. Statistical assemblies of conducting elements need only partially fill a surface or volume to obtain conduction. For a surface the percolation threshold is at half-saturation of the sites. For a three-dimensional pore only one-sixth of the sites need be filled. 

The occurrence of fewer secondary cracking reactions in the MR is confirmed by the significant deviations in the LPG olefmicity. This is the ratio of unsaturated to saturated components in the LPG fraction and is a typical indicator for secondary hydrogen-transfer reactions. The definition of this ratio is given in equation 1. Figure 5 shows this... 

For a gas at temperature T and pressure P containing a single condensable vapor A with mole fraction y>A and vapor pressure pXiT), Raoult s law [j a/ = Pa( )1 provides the basis for a number of definitions. If Raoult s law is satisfied, the vapor is saturated (or equivalently, the gas is saturated with A) if VaP < Pa(T), the vapor is superheated. If A is saturated and either the temperature is decreased or the pressure is increased, A will begin to condense. If liquid A is in contact with a gas phase and the system is at equilibrium, the A vapor in the gas must be saturated. 

After having been deprived of these three fractions, the liquid still contains albuminoid substances in solution, which can be diAdded into two new fractions. The first is precipitated when the liquid, previously saturated with anunonium sulphate, is addified the second remains in solution. We have, thus, definitely separated all the products of peptic hydrolysis into five portions. 

Saturation of a reabsorptive system will, by definition, increase the fractional excretion of ifs subsfrate. As an example of the important use to which such observations can be put, reference may be made to the report that at high bolus concentrations of metallothionein (MT) the... 

The half-lives of the unsaturated compounds were smaller than the half-lives of the corresponding saturated compounds. This effect was expected because natural rubber is non-polar, and on non-polar GC liquid phases unsaturated compounds have shorter retention times than saturated. By broadening the definition of N to equivalent carbon number with the saturated compounds as the reference, monoenes can be correlated with the same regression equation parameters (Equation 4) as the saturated compounds. The N values may then possess fractional values. In the acetate series at 20 C, the N values for the monoenes were as follows (14) Z7-12 Ac,... 

Generally, asphalt can be fractionated into four important fractions saturates, aromatics, resins, and asphaltenes . The classic definition of fractions of asphalts is based on the solution properties of petroleum residuum in various solvents. A complete fractionation scheme is given in Figure 1 (1) the oil constituents are propane soluble (2) resins are n-pentane soluble but propane insoluble (3) asphaltenes are toluene soluble but n-pentane insoluble and (4) preasphaltenes are insoluble both in n-pentane and toluene. The fractionated part of oil is generally considered to be a combination of saturates and aromatics. The polarity of these four fractions increases from saturates, to aromatics, to resins, to asphdtenes. 

Definition of Raoult s law The partial pressure p, of component i in the vapor phase is at an adjusted equilibrium proportional to the mole fraction Xj in the liquid phase. The saturated vapor pressure depends on the equilibrium temperature. 

Have all the proteins required for initiation now been identified There is no doubt that the seven factors are sufficient to promote initiation, but in comparison with the crude reticulocyte lysate these systems that use purified components function at a very slow rate - of the order of 0 (II). Moreover, the amounts of initiation factors required to obtain maximal rates in the fractionated system seem very hi. Although there are no firm estimates of the concentrations of initiation factors in crude lysates, few would dispute that they are probably lower than the levels used in fractionated systems, where, with one exception, the relationship between the quantities of factors added and the number of initiation events is such that each molecule of factor might function only once in a stoichiometric manner. The exception is eIF-5 which saturates at low levels and definitely acts catalytically. For the other factors, the explanation may be that there is a large fraction of denatured factor which is defective in catalysing the correct overall reaction, but can interfere with the action of the fully active factor, and thereby cause a low rate of... 

Measurement of dye adsorption with the purpose of determining wettability of sandstone cores was first proposed by Holbrook and Bernard (3). These authors defined relative water wettability as the fraction of the total surface area of a core that is contacted by injected water. There follows from this definition that if this fractional area were found to be a function of the saturation of the core then relative water wettability is also saturation dependent. 

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