Liquid volume, increased, effect

The increase in density on melting is assumed to arise from two competing effects that occur as water is heated. First, increasing translational freedom for the water molecules weakens the hydrogen-bonded network that exists in ice I. This network thus collapses, and reduces the volume. Second, increased vibrational energy for the molecules causes an effective increase in the volume occupied by any one molecule, thus enlarging the overall volume of the liquid. The first effect is considered to predominate below 4 °C, the second above 4 °C. 

Further, the constancy of bubble volume with flow rate at small flow rates which is observed by many investigators is true only for inviscid liquids having high surface-tension effects. If highly viscous liquids (n > 500 cp) are used, the bubble volume increases very fast with the flow rate. On increasing the... 

Flotation. Flotation (qv) is used alone or in combination with washing and cleaning to deink office paper and mixtures of old newsprint and old magazines (26). An effective flotation process must fulfill four functions. (/) The process must efficiently entrain air. Air bubble diameter is about 1000 Jim. Typically air bubbles occupy 25—60% of the flotation cell volume. Increasing the air liquid ratio in the flotation cell is said to improve ink removal efficiency (27). (2) Ink must attach to air bubbles. This is primarily a function of surfactant chemistry. Air bubbles must have sufficient residence time in the cell for ink attachment to occur. (3) There must be minimal trapping of cellulose fibers in the froth layer. This depends on both cell design and surfactant chemistry. (4) The froth layer must be separated from the pulp slurry before too many air bubbles collapse and return ink particles to the pulp slurry. 

The exposure can be either in air or a liquid chosen to simulate service conditions. Commonly, ring test pieces are chosen for liquid exposure, so simulating the geometry of practical seals and giving a relatively large surface area to volume ratio so that equilibrium swelling is reached reasonably quickly. It should be noted that the swelling effect of the liquid will affect the relaxation pattern measured and an increase in stress may be seen over a limited time period if there is a volume increase. 

For flash vaporization injection, the effect of injection speed, choice of solvent, and injector temperature greatly affect the solvent peak width. Injection of a low-boiling solvent at high injector temperatures can cause the entire expansion volume of the liner to be exceeded by the expanded solvent. It must be remembered that 1 pi of liquid solvent injected at 250°C at 10 psig head pressure is converted to some 200-1000 pi of gas. Thus, as the injection volume increases, the injection rate should be adjusted so as not to exceed the expansion volume available in the port liner. Generally, nonpolar solvents perform best in the direct flash mode. The injection rate should follow the following formula [26] ... 

They found that optimal conditions of the position of the stirrer exist in the range of 0.25 < HJd < 0.75 for both turbine and propeller stirrers. Their work suggests that beyond a Reynolds number of 20,000, the power number becomes constant. An increase in solid content increases the power consumption, while an increase in gas velocity reduces the power consumption. Kurten and Zehner (1979) examined the effect of gas velocity on the power consumption for suspension of solids and found that because of simultaneous aeration, a higher power input is required for suspension in the presence of gas. This is mainly due to the reduced liquid circulation velocity in the presence of gas bubbles. Most recently, Albal et al. (1983) evaluated the effect of liquid properties on power consumption for both two- and three-phase systems. They found that power consumption per unit volume increases with solid concentration. The influence of particle size on power consumption increases with the solids concentration. For an unconventional arrangement of a stirrer, they also found different Ne-Re curves for glycerine and CMC solutions. 

Increase of pressure has also the effect of bringing the gaseous molecules closer and closer to one another (due to decrease in volume). This is an additional helpful factor in converting a gas into liquid. Thus, increase of pressure and decrease of temperature both tend to cause liquefaction of gases. For instance, sulphur dioxide can be liquefied at -8 C if the pressure is 1 atm. But it can be liquefied even at a higher temperature of 20 C if the pressure is increased to 3.24 atm. 

Figure 1.16. Effects of a sharp edge on the contact angle formed by a meniscus advancing on a solid surface. In (a) 1,2,3 and 4 denote the successive configurations of the liquid surface when the liquid volume is increased. With a constant volume of liquid, an advancing triple line is either pinned (b) or...

Figure 1.29. (a) Successive configurations of a meniscus on a vertical solid surface consisting of two macroscopic phases when the liquid volume is increased, (b) Effect of a small chemical heterogeneity... 

It should be noted that the formula about the modulus of bulk elasticity of a foam refers to deformation at both compression and expansion. At large deformations, however, their effects differ significantly. When the foam is compressed the gas volume can be reduced so that to become comparable to the liquid volume. The expansion of a foam cannot be unlimited depending on its initial expansion ratio, the volume of the foam can increase only until the border pressure reaches a critical value (see Section 6.5.2). The latter is related to foam dispersity and surfactant adsorption, and decreases with the increase in surface area. 

Many of the thermodynamic and transport properties of liquid water can be qualitatively understood if attention is focused on the statistical properties of the hydrogen bond network [9]. As an example, let us observe the temperature dependence of density and entropy. As temperature decreases, the number of intact bonds increases and the coordination number is closer to the ideal value 4. Because of the large free volume available the temperature decrease is associated with an increase of the local molecular volume. This effect superimposes of course to the classical anharmonic effects which dominate at high temperature, when the number of intact bonds is smaller. The consequence of both effects is a maximum on the temperature dependence of the liquid density. This maximum is actually at 4°C for normal water and 11 °C for heavy water. Such a large isotopic effect can also be understood because the larger mass of the deuterium makes the hydrogen bonds more stable. 

A temperature 85°C is higher than the critical crystallization temperature [33] of n-octadecanol monolayer. This means that the highest surface concentration of the monolayer, irrespective of the amount of n-octadecanol deposited on silica gel, is equal to 0.27 nm per molecule. The run of Vs vs r diagram for n-octane is slightly different from that at 40°C. The retention volumes increase with r up to a surfaee concentration 0.57 nm, but without a noticeable effect of silica gel surface deactivation, and next decrease to a minimum at r corresponding to 0.27 nm per n-octadecanol molecule, i.e. at the surface concentration characteristic for LE phase. The Vs increase beginning from this value is the result of n-octane dissolution in liquid threedimensional n-octadecanol. 

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