Single solutes

Although preparative HPLC is by definition a technique of separation (which implies that at least two components must be present in the mixture), it is useful to consider the situation when one component only is overloaded. This is not only the sim- 

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Figure 8.2 Schematic illustrations of AGm versus X2 showing how jUj -may be determined by the tangent drawn at any point, (a) The polymer-solvent system forms a single solution at all compositions, (b) Compositions between the two minima separate into equilibrium phases P and Q.

Whereas a linear relation between flow stress and lattice-parameter change is obeyed for any single solute element in nickel, the change in yield stress for various solutes in nickel is not a single-valued function of the lattice parameter, but depends directly on the position of the solute in the Periodic Table... 

Adsorption and ion exchange share so many common features in regard to apphcation in batch and fixed-bed processes that they can be grouped together as sorption for a unified treatment. These processes involve the transfer and resulting equilibrium distribution of one or more solutes between a fluid phase and particles. The partitioning of a single solute between fluid and sorbed phases or the selectivity of a sorbent towards multiple solutes makes it possible to separate solutes from a bulk fluid phase or from one another. 

A linearized, acoustic approach was found satisfactory for the description of the near-piston region for low piston Maeh-numbers by Guirao et al. (1976) and Gorev and Bystrov (1985). The linearized equations, however, provided a single solution at the location of the leading shock. 

In Chapter 13 we dealt with the equilibrium established when a single solute, either a weak acid or a weak base, is added to water. This chapter focuses on the equilibrium established when two different solutes are mixed in water solution. These solutes may be—... 

These ideas, developed for an electrochemical cell, have great importance in chemistry because they are also applicable to chemical reactions that occur in a single beaker. Without an electric circuit or an opportunity for electric current to flow, the chemical changes that occur in a cell can be duplicated in a single solution. It is reasonable to apply the same explanation. 

As before ft s without superscript refer to the clathrate for convenience we neglect the vapor pressure of Q, but this is not essential. Equilibrium between clathrate and gas was implicitly assumed in our derivation it led to Eq. 12. Equilibrium between clathrate and Qa is governed by Eq. 21 with the = sign. Repeating these equations for a single solute A we have... 

Without disclosing security information we can state that at present we are making 10,000 heavy metal ion determinations annually by means of the x-ray photometer and that we expect this number to increase as we find new applications among essential materials, process reagents, and others. We estimate that use of the instrument saves approximately 3000 man-hours annually. This figure is estimated on the basis that analysis of a single solution by x-ray requires 20 minutes, whereas other methods require twice this time. 

It is possible that the aluminum octahedra may be of more than one kind. In this case average values of the sums would have to be used in Equations 4 and 5, and the equations would no longer possess a single solution. 

In practice, it is probable that both of the effects discussed contribute to the overall peak asymmetry. Unfortunately, peak asymmetry varies in extent from the very obvious to the barely noticeable and because of this, peak asymmetry is often dismissed as the normal shape of a single solute peak. Such an assumption can cause serious errors in both qualitative and quantitative analysis. 

Fig. 10.9 Diagram of steady states I and III are domains of existence of single solution, II is a domain of existence of three solutions (two stable and one unstable). Lines A and A2 correspond to two stable solutions. Reprinted from Yarin et al. (2002) with permission...

In partly frozen solutions, M is independent both of the nature of the solutes and of their total concentration prior to freezing. At constant pressure it is dependent only on temperature. For a solution containing a single solute, this is also roughly true of the molality m (It is only roughly true because < > changes somewhat with concentration.)... 

This pulse plating technique has the advantage of simplicity, i.e., application of a simple waveform in current or potential in a single solution. Problems arise, however, because at the more positive potential a pure element or compound is deposited, while during the pulse the second element or compound formed is inevitably contaminated with the first. Switzer et al. [73] reported a variation on... 

Micellar flooding is a promising tertiary oil-recovery method, perhaps the only method that has been shown to be successful in the field for depleted light oil reservoirs. As a tertiary recovery method, the micellar flooding process has desirable features of several chemical methods (e.g., miscible-type displacement) and is less susceptible to some of the drawbacks of chemical methods, such as adsorption. It has been shown that a suitable preflush can considerably curtail the surfactant loss to the rock matrix. In addition, the use of multiple micellar solutions, selected on the basis of phase behavior, can increase oil recovery with respect to the amount of surfactant, in comparison with a single solution. Laboratory tests showed that oil recovery-to-slug volume ratios as high as 15 can be achieved [439]. 

Volumes Vl and Vq of the two immiscible liquid phases, are added to the extraction vessel and a single solute distributes itself between the phases as concentrations X and Y, respectively, at a rate, Q, as shown in Fig. 3.30. 

Figure 3.30. Single-solute batch extraction between immiscible liquid phases.

The previous treatments have been confined to the case of single-solute extraction between immiscible liquid phases. Assuming the liquid phases... 

For single-solute, gas-liquid mass transfer, the component balances are as before... 

This section concerns the modelling of countercurrent flow, differential mass transfer applications, for both steady-state and non-steady-state design or simulation purposes. For simplicity, the treatment is restricted to the case of a single solute, transferring between two inert phases, as in the standard treatments of liquid-liquid extraction or gas absorption column design. 

Consider a batch two-phase extraction system, with a single solute. 

For their current density technique at the dme, Kies and Van Dam82c reported a standard deviation for a single solution (8 10 5 AfTlN03), based on 11 recordings, of 0.5% and rectilinear calibration graphs in the range 20-1000 nM. 

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