Composite secondary phase effect

M. A Lopes, F. J. Monteiro, J. D. Santos. Glass-reinforced hydroxyapatite composites Secondary phase proportions and densiftcation effects on biaxial bending strength. J. Biomed. Mater. Res. Appl. Biomater. 1999 48 734-740... 

Since other secondary interactive effects, e.g. electrostatic effects, can also contribute with a particular type of RPC sorbent to the retention of peptides as the mobile-phase composition is changed, the shape of these In k versus ip plots then over the range 0.0 < ip < 1.0 takes on the characteristic U-shaped dependencies.112,211 As a consequence of these dependencies of In k on ip, for mixtures of peptides elution usually requires the use of gradient elution conditions, even when closely related or homologous peptides are being separated. 

Factors that affect rennet coagulation. The effect of various compositional and environmental factors on the primary and secondary phases of rennet coagulation and on the overall coagulation process are summarized in Figure 10.4. 

Equation (1-7) shows that in an ideal case the selectivity of the system is only dependent on the difference in the analytes interaction with the stationary phase. It is important to note that the energetic term responsible for the eluent interactions was canceled out, and this means that the eluent type and the eluent composition in an ideal case does not have any influence on the separation selectivity. In a real situation, eluent type and composition may influence the analyte ionization, solvation, and other secondary equilibria effects that will have effect on the selectivity, but this is only secondary effect. 

Despite the linear relation between the composition of the feedstock and that of the deposited flhns, it can be noted that the concentration of nickel doping in the deposited films was lower than that of the liquid feedstock. This effect might be justified either by a selective depletion of the nickel precursor during the transport or by its lower sticking coefficient on the surface of the substrate at the deposition temperature. The IR analyses of the deposited NixCo3.x04 (0 < x < 1) films, not shown, revealed their spinel structure, and a shift of the characteristic vibration bands indicated the incorporation of nickel into the spinel lattice. Further evidence about the controlled incorporation of nickel into the lattice of cobalt oxide can be drawn from conductivity measurements. Fig. 5b shows a substantial increase in conductivity as a function of the concentration of nickel incorporated into the film. The formation of a secondary phase should be expressed by a discontinuity, which is clearly absent in the investigated range of conditions. 

Chapter 12 of Ref. 79)]. Next, secondary>retention effects 88) that can affiwt separation are considered, and ropriate changes in mol -phase composition are made ... 

In the case of SEC separations, knowing the sample molecular weight allows us to choose the right pore size column prior to the first HPLC run. An initial separation is then followed by adjustments in mobile-phase composition or additives, in order to minimize any secondary-retention effects (see preceding section). 

The PVS mixture mle is also applied to study the effect of residual porosity on sintering behaviors of the Zr02-TiN composite powders, by incorporating porosity as a third phase with zero conductivity. With this assumption, Eqs. (6.19) and (6.20) are still applicable, by using a reduced volume concentration of the secondary phase, y, due to the presence of the pores. The reduced volume concentration can be related to relative density (D) of the sintering powder compacts, given by V = D — y, where y is the volume fraction of the matrix phase in partially sintered compacts. 

Upon cooling, these liquid phases remain as glassy phases or as secondary crystalline phases in the sintered materials consequently, these hquid-phase-sintered ceramics are actually composite materials consisting of a matrix of grains and dispersed secondary phases. The thermal conductivity of these composite materials will depend on the amount, distribution state and thermal conductivity of each constituent phase in the structure. The effects of secondary phases on the thermal conductivity ofliquid-phase-sintered nonoxide ceramics are discussed in the following subsection. 

In this section, the mechanical properties of carbides and borides of Zr-, Hf- and Ta-based composites are presented and correlated to the morphological features with particular attention to the effect of the secondary phases on the high temperature behaviour. The mechanical properties of the UHTCs presented in this chapter are summarized in Table 4. 

The composition of the primary emulsion dispersed phase may have a significant effect on the overall stability of a system, especially when interactions between the components and surfactant are possible, or when the components themselves may be somewhat surface-active. In most instances of multiple-emulsion formulation, the internal primary and external secondary phases will be similar in that each will be aqueous or an oil, but the nature of addenda included in each will differ. In particular, there may be significant differences in the level and nature of organic additives and electrolytes present that could alter the stability of the total system. 

In most situations the eluent composition is chosen to minimize the effects of hydrophobic interaction, but these secondary effects can be used to advantage. By careful selection of a salt and its concentration, specific selectivities for analytes can be achieved without the use of organic solvents. Therefore, many separations usually run by solvent gradient reversed-phase methods can be completed with a purely aqueous isocratic eluent (13,14). 

Ticlopidine inhibits the P2Yj2 platelet ADP receptor, thus inhibiting ADP-dependent activation of the GP Ilb/IIIa receptor. It has a slow onset of action and takes 3-7 days to reach its maximal antiplatelet effect. It is inactive in vitro and must undergo activation by the hepatic cytochrome p450 enzyme system. Secondary prevention trials have found that ticlopidine-treated patients have an estimated RRR of 33% for the composite endpoint of stroke, myocardial infarction, or vascular death after ischemic stroke. Significant adverse effects include bone marrow depression, rash, diarrhea, and thrombotic thrombocytopenic purpura. No clinical trials have studied ticlopidine for the treatment of stroke in the acute phase. 

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