Solid-Liquid Phase

The dependence on the temperature of the specific resistance (Q/cm) of the pure MEPBr and MEMBr complexes, and a 1 1 mixture there of, as obtained in Ref. [73], is listed in Table 4. It is remarkable that within the complex phases consisting of Br2 and either pure MEP or MEM the change of specific resistance at the liquid —> solid phase transition amounts to about one order of magnitude, where as the value is only doubled in the 1 1 mixture. The table also indicates that MEMBr complexes possess higher melting temperatures. 

In the case of (Ala-Gly-Pro)n with n = 5-15, the tripeptide chains were synthesized by the liquid-solid phase technique. As mentioned above, the coupling of longer preformed peptide chains was difficult and the yield of the trimer was low. Therefore, a liquid-solid phase technique was applied in which a trimer was grown in a stepwise manner, beginning from a trifunctional crosslinked base A. 

Volume Gas phase, LVI, LV HSI, LVS, PLC Liquid/solid phase, CIS, CT, SPME, nano-ESI... 

Fig. 2. Phase diagram for the AlCl -EtMeImCl molten salt ( ) liquid-solid phase transitions and (O) glass transitions. Adapted from Fannin et al. [33] by permission of the American Chemical Society, Inc.

We now look at the phase diagram for water in Figure 5.10. Ice melts at 0 °C if the pressure is p° (as represented by T and Pi respectively on the figure). If the pressure exerted on the ice increases to P2, then the freezing temperature decreases to 7). (The freezing temperature decreases in response to the negative slope of the liquid-solid phase boundary (see the inset to Figure 5.10), which is most unusual virtually all other substances show a positive slope of (lp/dT.)... 

The Clapeyron equation, Equation (5.1), yields a quantitative description of a phase boundary on a phase diagram. Equation (5.1) works quite well for the liquid-solid phase boundary, but if the equilibrium is boiling or sublimation - both of which involve a gaseous phase - then the Clapeyron equation is a poor predictor. 

Solidification Stefan Number St = cplAT/AHm Compare sensible to latent heat in liquid-solid phase change Matson et al. [409]... 

Taking an entirely different tack on supported phase transfer catalysts, Sawicki, Chapter 12, initially used polyethers chemically bound to silica. But, he also demonstrated that solid silica or alumina alone may function as liquid-solid phase transfer catalysts, probably through mechanisms entirely different than the classical PTC sequence. 

Figure 4. Liquid—solid phase diagrams of EC/DMC, EC/ EMC, and PC/EC. (Reproduced with permission from ref 159 (Figure 9). Copyright 2000 The Electrochemical Society.)...

The method of latent heat storage based on liquid-solid phase transition is available to make smaller the volume of heat storage tank, because of its higher thermal density than that of sensible heat storage. Therefore, a substance which has a large amount of latent heat of fusion is more profitable as a heat storage material. 

For phase diagrams, a phase boundary is one end of a tie-line and, therefore, is dependent on the phase which exists at the other end of the tie-line. In a binary system, two independent measurements are therefore needed to define the tie-line in the case of a liquid/solid phase boundary this would be and Xg at temperature T. Ideally it would be desirable to have these two compositions as independent variables giving rise to two independent equations of error. The Lukas programme does this by making two equations but where the dependence of error on one of the measurements is weak. This is important if the two concentrations have different accuracies. For some types of experimental values newer versions of the Lukas programme offer different kinds of equations of error (Lukas and Fries 1992). 

The ultimate aim of scientists has always been to be able to see molecules while active. In order to achieve this goal, the microscope should be able to operate under ambient conditions. Further, all kinds of molecular interactions between a solid and its environment (gas or liquid or solid), initially, can take place only via the surface molecules of the interface. It is obvious that, when a solid or liquid interacts with another phase, knowledge of the molecular structures at these interfaces is of interest. The term surface is generally used in the context of gas-liquid or gas-solid phase boundaries, while the term interface is used for liquid-liquid or liquid-solid phases. Furthermore, many fundamental properties of surfaces are characterized by morphology scales of the order of 1 to 20 nm (1 nm = 10-9 m = 10 A (Angstrom = 10-8 cm). 

So, for this binary solution of components A and B, which mix perfectly at all compositions, there is a two-phase region at which both solid and liquid phases can coexist. The uppermost boundary between the liquid and liquid + solid phase regions in Figure 2.3f is known as the liquidus, or the point at which solid first begins to form when a melt of constant composition is cooled under equilibrium conditions. Similarly, the lower phase boundary between the solid and liquid + solid phase regions is known as the solidus, or the point at which solidification is complete upon further equilibrium cooling at a fixed composition. 

Let us first consider the liquid-solid phase transformation. At the melting point (or more appropriately, fusion point for a solidification process), liquid and solid are in equilibrium with each other. At equilibrium, we know that the free energy change for the liquid-solid transition must be zero. We can modify Eq. (2.11) for this situation... 

Solidification. When the ingot or casting solidifies, there are three main possible microstructures that form (see Figure 7.5). We will describe here only the final structures the thermodynamics of the liquid-solid phase transformation have been described previously in Chapter 2. The outside layer of the ingot is called the chill zone and consists of a thin layer of equiaxed crystals with random orientation. 

Conventional radiochemical methods for the determination of long-lived radionuclides at low concentration levels require a careful chemical separation of the analyte, e.g., by liquid-liquid, solid phase extraction or ion chromatography. The chemical separation of the interferents from the long-lived radionuclide at the ultratrace level and its enrichment in order to achieve low detection limits is often very time consuming. Inorganic mass spectrometry is especially advantageous in comparison to radioanalytical techniques for the characterization of radionuclides with long half-lives (> 104 a) at the ultratrace level and very low radioactive environmental or waste samples. 

To single out the peculiarities in the phase behavior of ionic fluids, it is convenient to consider first the behavior of nonionic (e.g., van der Waals-like) mixtures. We note, however, that the subsequent considerations ignore liquid-solid phase equilibria, which in real electrolyte solutions can lead to far more complex topologies of the phase diagrams than discussed here [150],... 

Taken from K. Roth, G. Schneider, and E. U. Franck, Liquid-Liquid and Liquid-Solid Phase Equilibriums in Cyclohexane-Methanol and Phenol-Water Systems up to 6000 Bars , Ber. Bunsenges. Physik. Chem., 70, 5-10 (1966). 

ESPS thus shares a number of the advantages that ESIT has with respect to integration methods (Sections IV.A.2 and IV.C.2). It is pleasingly transparent The evolution with temperature of the relative stability of fee and hep LJ crystals can be read off from Fig. 7 and the LJ freezing pressure can be seen in Fig. 9. Apart from finite-size effects, uncertainties are purely statistical. The fact that both phases are realized within the same simulation means that finite-size effects can be handled more systematically this seems to be a particular advantage of the ESPS approach to the liquid-solid phase boundary. 

Due to the complexity of mass transfer between gas-liquid-solid phases, it is difficult to evaluate the average value of mass transfer coefficient ki from the literature. A realistic way to evaluate ki is to use the algebraic expression of solution and by regression to obtain the experimental data rather than by regression with solving the set of non-linear differential equations. 

Liquid-gas or solid-gas separation exergy loss can usually be neglected as long as the saturation vapour pressure of the liquid (solid) phase is low (and kinetics fast enough). 

The use of a phase-change media circumvents many of these problems. A material slightly above its liquid/solid-phase transition temperature may be ejected from a jet-printing nozzle the droplet solidifies quickly upon contact with a cooler surface. The feature size will then depend more on the cooling rate and less on the material s wetting properties, because a frozen droplet cannot spread. In this situation, the substrate temperature controls the printed feature size for materials having excellent wetting properties. 

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