Wetting incomplete

Liquid remains as a discrete drop Complete wetting Incomplete wetting... 

Circffiation and heat transfer in this type of evaporator are strongly affected by the liquid level. Highest heat-transfer coefficients are achieved when the level, as indicated by an external gauge glass, is only about halfway up the tubes. Shght reductions in level below the optimum result in incomplete wetting of the tube walls with a consequent increased tendency to foul and a rapid reduction in capacity. When this type of evaporator is used with a liquid that can deposit salt or scale, it is customary to operate with the liquid level appreciably higher than the optimum and usually appreciably above the top tube sheet. 

Cassie [39] extended Wenzel s treatment to composite surfaces. His treatment can be applied to a rough surface incompletely wetted by a liquid so that it consists of an area fraction f wetted and /2 unwetted surface. Then ... 

Estimate the effective fraction w etted packing area by Figure 9-46 or 9-43. As a general rule, try not to accept design if fraction wetted is le.ss than 0.5. If it is less, adjust tower conditions to raise value, bearing in mind that this factor is based on scattered and very incomplete data. 

In RPs, insufficient compaction and consolidation before plastic solidification or cure will result in air pockets, incomplete wet-out and encapsulation of the fibers, and/or insufficient fiber or uniform fiber content. These deficiencies lead to loss of strength and stiffness and susceptibility to deterioration by water and aggressive agents. 

Huse has pointed out that strain is to be expected in most thin-film systems, since even in the incommensurate case the intrinsic surface stress will strain the film (18). As a result, we conclude that incomplete wetting is expected for all crystalline films, except in the case where there is an epitaxial relationship between film and substrate and that the film is maintained at its bulk equilibrium lattice spacing. 

The calculation above is vahd for a spherical nucleus forming in bulk solution or on an electrode surface completely wetted by the hquid electrolyte, where the wetting angle a — 0 (Fig. 14.8a). The work of nucleation decreases markedly when wetting is incomplete (Fig. 14.8fc), since the electrode-electrolyte contact area is smaller. The work also decreases when asperities, microcracks, and the like are present on the surface. Thus, Eq. (14.33) states merely the highest possible value of work... 

FIGURE 14.8 Gas-bubble nuclei on an electrode with (a) complete and (b) incomplete wetting of the surface by the liquid, and (c) a gas bubble at the moment of tearing away. 

Some rare-earth fluoride samples had been wet-ashed incompletely with the three mixed acids and some gave low results. These samples, now containing pyridine, were reprocessed by addition of more acids and slow evaporation on a hot-plate. One of the samples frothed up and then exploded violently. Pyridinium perchlorate seems likely to have been involved. 

Wet chemical oxidation methods, using oxidants such as persulfate, are widely used in oceanographic and limnologic work [46,47]. The main drawbacks of these methods are their manual and cumbersome techniques and incomplete oxidation of some organic compounds [48]. 

Initially, results reported for dry-combustion methods were found to be higher than wet-oxidation methods based on persulfate by factors of 2 or more. This discrepancy has steadily decreased as methodologies have improved. Contamination problems of dry methods have been reduced and the oxidation efficiency of the wet methods has been improved. While the differences between approaches have been discussed [94,95], there is still uncertainty whether the remaining difference between the two techniques is real - a result of incomplete oxidation, incorrect estimation of blanks, or a combination of both. 

Hysteresis is observed not only in the sorption isotherms but also in calorimetric measurements of heat of wetting at different moisture contents, and it is thus a combined entropy and enthalpy phenomenon. A reliable explanation for this effect is not currently available, but there is speculation that it is due to the stresses which are induced as the cellulose swells. Since the swelling of cellulose is not completely reversible, mechanical recovery is incomplete and hysteresis will therefore be present both in the internal stress-strain curve of the sample, and also in the water adsorption isotherm. 

These authors also report a comparison of the efficacy of wet cells compared with heat-dried cells and with Pichia extracts. This appears to show the best result with the extracts, but it is difficult to assess the meaning of this study. The outcome is reported in terms of percentage yield of the final product, and it is impossible to judge whether what is being observed reflects different amounts of activity and incomplete reactions, varying stability of the biocatalyst in its various states, interfering side reactions due to other cellular activities, and so on. It is not clear to what extent reaction under each set of conditions was optimized or maximized. 

Several investigators have utilized thermal techniques for the separation of sulfate species collected on filter media with subsequent analysis by electron impact mass spectrometry, wet chemical analysis or sulfur flame photometry. In most instances the separation between sulfuric acid and its ammonium salts was incomplete or problems were encountered in recovering the species of interest from filters heavily laden with particulate (29-34). 

These contact angles can be related to the physical state of the surface. The 100 facet is better wetted than the 111 one because the 100 surface is partly premelted. But, the liquid-like disordered monolayer is too thin to have the properties of the macroscopic liquid, and this "adsorbed liquid layer" coexists with a non-wetting macroscopic liquid. This so-called "incomplete surface melting" has also been observed on a pure single crystal of ice. ... 

Dampproofed concrete, therefore, should not show significant uptake of surface water in conditions of rain and wind up to about 100 km h T In fact, on prolonged exposure, some wetting does occur, because of defects in the hydrophobic coating, and the presence of larger voids in the concrete, up to perhaps 1 mm wide these are due to incomplete compaction, or to the nature of the concrete in the case of blocks. 

Ar" backsputter as a standard pre-metal clean or Incomplete resist and/or developer removal In wet patterning results In an ohmlcally conducting surface of sheet resistivity 1.5 x 10 Q/q. Otherwise polylmlde film surfaces are not measurably conductive. 

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