Water saturation value

Nine sample strips (about 100x10x0.1 mm) of the polymers listed in Table 7.10 were first dried at 50°C in vacuum until constant sample weights were reached. The dry samples were stored subsequently for more than two years in ion-free water (in the dark) at 20 1°C. Then the weight increase due to water absorption was measured on surface-dry samples. The samples and the equilibrium water saturation values measured are listed in Table 7.10. 

Table 7.10 The equilibrium water saturation values measured a ter more than two years of water immersion.

The calculated equilibrium water saturation of 1.23 %wt. holds for completely amorphous PK copolymer i.e. if x(c) > 0.63, the equilibrium water saturation value of the semi-crystalline polymer as such, becomes 0.50 %wt. The equilibrium water saturation, measured on sheet material in demineralised water at 20°C, was 2.55 %wt. The calculated water saturation depends in this case mainly on the molar water content value of the CO group used. The calculated value is about five times too low and this illustrates again the necessity of looking for better defined molar water content values. 

Macroscopic resistivity anisotropy of laminated sediments has been described by Hagiwara (1994, 1996, 1997), Klein (1996), and Klein et al. (1997). Hagiwara (1994) describes anisotropy as the result of the parallel layering of sand and shale. Klein (1996) and Klein et al. (1997) focussed their investigations on modelling of binary, anisotropic sands they demonstrated the effects of macroporous and microporous layers of different water saturation upon resistivity anisotropy. Mollison et al. (1999) and Schon et al. (1999, 2000) derived a modular tensor model to analyse multicomponent induction measurements in anisotropic formations. Kennedy and Herrick (2003) studied the conductivity anisotropy in shale-free sandstone and derived water saturation values of the two sand fractions related to the height above the free water level. 

Referring to Fig. IV-4, the angles a and /3 for a lens of isobutyl alcohol on water are 42.5° and 3°, respectively. The surface tension of water saturated with the alcohol is 24.5 dyn/cm the interfacial tension between the two liquids is 2.0 dyn/cm, and the surface tension of n-heptyl alcohol is 23.0 dyn/cm. Calculate the value of the angle 7 in the figure. Which equation, IV-6 or IV-9, represents these data better Calculate the thickness of an infinite lens of isobutyl alcohol on water. 

The main reason for the importance of aeration Hes in the limited solubiUty of oxygen in water, a value which decreases in the presence of electrolytes and other solutes and as temperature increases. A typical value for the solubiUty of oxygen (the equiUbrium saturation concentration) in water in the presence of air at atmospheric pressure at 25°C is about 0.008 kg 02/m (= Sparts per million = 0.25 mmol/L). Thus, for a yeast or bacterial bioreaction demanding oxygen at the rates given in Table 1, all oxygen is utilized in about 10 to 40 s (3,7). 

FIG. 2-11 Enthalpy-concentration diagram for aqueous hydrogen chloride at 1 atm. Reference states enthalpy of liquid water at 0 C is zero enthalpy of pure saturated HCl vapor at 1 atm (—85.03 C) is 8000 kcal/moL NOTE It should he observed that the weight basis includes the vapor, which is particularly important in the two-phase region. Saturation values may be read at the ends of the tie lines. [Van Nuys, Trans. Am. Inst. Chem. Eng., 39, 663 (1943).]... 

Peat Peat is partially decomposed plant matter that has accumulated underwater or in a water-saturated environment. It is the precursor of coal but is not classified as coal. Sold under the term peat moss or moss peat, peat is used in the United States mainly for horticultural and agricultural apphcations, but interest is growing in its use as a fuel in certain local areas (e.g.. North Carolina). Peat is used extensively as a fuel primarily in Ireland and the former Soviet Union. Although analyses of peat vary widely, a typical high-grade peat has 90 percent water, 3 percent fixed carbon, 5 percent volatile matter, 1.5 percent ash, and O.IO percent sulfur. The moisture-free heating value is approximately 20.9 MJ/kg (9000 Btu/lb). 

It is necessary to draw attention to the variable pH of water which may be encountered in quantitative analysis. Water in equilibrium with the normal atmosphere which contains 0.03 per cent by volume of carbon dioxide has a pH of about 5.7 very carefully prepared conductivity water has a pH close to 7 water saturated with carbon dioxide under a pressure of one atmosphere has a pH of about 3.7 at 25 °C. The analyst may therefore be dealing, according to the conditions that prevail in the laboratory, with water having a pH between the two extremes pH 3.7 and pH 7. Hence for indicators which show their alkaline colours at pH values above 4.5, the effect of carbon dioxide introduced during a titration, either from the atmosphere or from the titrating solutions, must be seriously considered. This subject is discussed again later (Section 10.12). 

In an experimental wetted wall column, pure carbon dioxide, is absorbed in water. The mass transfer rate is calculated using the penetration theory, application of which is limited by the fact that the concentration should not teach more than 1 per cent of the saturation value at a depth below the surface at which the velocity is 95 per cent of the surface velocity. What is the maximum length of column to which the theory can be applied if the flowrate of water is 3 cm3/s per cm of perimeter ... 

The humidity can be reduced by compressing air, allowing it to cool again to its original temperature, and draining off the water which has condensed. During compression, the partial pressure of the vapour is increased and condensation takes place as soon as it reaches the saturation value. Thus, if air is compressed to a high pressure, it becomes saturated with vapour, but the partial pressure is a small proportion of the total pressure. Compressed air from a cylinder therefore has a low humidity. Gas is frequently compressed before it is circulated so as to prevent condensation in the mains. 

The reliability of the experimental A / MX) values was checked for systems containing nitrobenzene, nitromethane, and 1,2-dichlo-roethane as organic solvent by comparing the differences in these values for various pairs of salts with the differences in the Galvani (i.e.,distribution) potemtials, A cp MX) for the same pairs. The differences should be the same. The A cp or Afip data can be used to estimate ion solvation energies in a water-saturated solvent. ... 

Salts such as silver chloride or lead sulfate which are ordinarily called insoluble do have a definite value of solubility in water. This value can be determined from conductance measurements of their saturated solutions. Since a very small amount of solute is present it must be completely dissociated into ions even in a saturated solution so that the equivalent conductivity, KV, is equal to the equivalent conductivity at infinite dilution which according to Kohlrausch s law is the sum of ionic conductances or ionic mobilities (ionic conductances are often referred to as ionic mobilities on account of the dependence of ionic conductances on the velocities at which ions migrate under the influence of an applied emf) ... 

El Khadem18 reported that D-glucosone gives a single spot when developed with collidine-water or phenol-water, Rp values of 0.21 and 0.13 respectively, being recorded. It was stated18 that no movement of the osone occurs on development with butanol saturated with water. Homo-... 

Solubility in water and vapor pressure are both saturation properties, i.e., they are measurements of the maximum capacity that a solvent phase has for dissolved chemical. Vapor pressure P (Pa) can be viewed as a solubility in air, the corresponding concentration C (mol/m3) being P/RT where R is the ideal gas constant (8.314 J/mol.K) and T is absolute temperature (K). Although most chemicals are present in the environment at concentrations well below saturation, these concentrations are useful for estimating air-water partition coefficients as ratios of saturation values. It is usually assumed... 

A tank contains 100 gal of brine with 50 lb of dissolved salt. The bottom of the tank is covered with a cake of salt whose surface may be assumed to remain substantially constant. The salt dissolves at a rate proportional to the difference between the conentration of the solution and the saturation value which is 3.0 lb/gal. If the water in the tank were fresh, the rate of solution would be 1.0 lb/min. Fresh water is allowed to run into the tank at... 

Because both Tg and water activity are functions of water content, the two parameters can be correlated to each other. This can be done in two main ways, as presented by Roos (1995). The first is to measure Tg of samples humidified to known water activity values (i.e., using saturated salt solutions) and then plot Tg values as a function of water activity (e.g., see Figure 6.2A in Roos, 1995). Over the entire nw range, a sigmoid-shaped curve was... 

When sufficient amounts of hydrocarbon chains are mixed with water, macroscopic phase separation takes place. The saturation value of hydrocarbon... 

Measurements of aqueous solubility and partition coefficient between cellulose acetate and water were compared for thirty disperse dyes and an approximate inverse relationship was postulated [60]. This can only be valid to a limited extent, however, because the partition ratio also depends on the saturation solubility of the dye in cellulose acetate. This property varies from dye to dye and is not directly related to aqueous solubility. The solubilities of four dyes in a range of solvents were compared with their saturation values on cellulose acetate. Solubilities in benzene showed no significant correlation. With the other solvents the degree of correlation increased in the order ethanol < ethyl acetate < 20% aqueous diethylene glycol diacetate (CH3COOCH2CH2OCH2CH2OCOCH3). The last-named compound was suggested as a model with polar groups similar to those in cellulose acetate [86]. 

Another similar approach would be to follow Wilson et al. (1988) in using different residual saturations for the vadose and water-saturated zones. Wilson et al. (1988) found sr values of 9 and 29% in the vadose and saturated zones, respectively. Hence, one could revise Equation 6.8 as follows ... 

For an unconsolidated porous medium with uniform pore size distribution, the ratio of VJHa approaches its maximum value much more rapidly than that found in a medium where pore size distribution is nonuniform, leading to the significant variation of water saturation in the contaminated zone. 

At 293 K, a supersaturated solution of sucrose contains 2.45 kg sucrose/kg water. If the equilibrium saturation value is 2.04 kg/kg water, what is the supersaturation ratio in terms of kg/kg water and kg/kg solution ... 

Compression. The humidity of a gas may be reduced by compressing it, cooling it down to near its original temperature, and then draining off the water which has condensed. During compression, the partial pressure of the water vapour increases and condensation occurs as soon as the saturation value is exceeded. 

If the modification imparts dimensional stability to the wood, the difference between the water-saturated and oven-dry volume of the wood sample is reduced, resulting in a lower value for S. The increase in dimensional stability can then be evaluated in terms of an anti-swelling efficiency (ASE) ... 

Samples with lEC values of 0.98-2.2 meq/g (x = 1-5) were prepared and found to be insoluble in water. In excess of lEC = 2.2 meq/g (x = 6), however, the polymer was found to form a hydrogel, thereby eliminating the possibility of forming a suitable film. Conductivity of water-saturated SDAPP was... 

This implies that vapor equilibration of PEMs corresponds to large negative liquid pressures inside the membrane or that Tj, would increase from zero to the saturation value for P very close to P. Moreover, the effect of the total gas pressure on water uptake should be insignificant at normal values of Ps 1 atm. Heuristic solutions out of this dilemma would be to recalibrate the value of V or to normalize P to a reference value of a... 

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