Analysis of wetting

Two main categories of the wet process exist, depending on whether the calcium sulfate is precipitated as the dihydrate or the hemihydrate. Operation at 70—80°C and 30% P20 in the Hquid phase results in the precipitation of CaSO 2 filterable form 80—90°C and 40% P20 provide a filterable CaSO O.5H2O. Operation outside these conditions generally results in poor filtration rates. A typical analysis of wet-process acid is given in Table 4. For more detailed discussion of the wet-process acid, see Fertilizers. 

Figure 14-9 also shows a flowchart for analysis of wet and dry precipitation. The process involves weight determinations, followed by pH and conductivity measurements, and finally chemical analysis for anions and cations. The pH measurements are made with a well-calibrated pH meter, with extreme care taken to avoid contaminating the sample. The metal ions Ca, Mg, Na, and are determined by flame photometry, which involves absorption of radiation by metal ions in a hot flame. Ammorda and the anions Cl, S04 , NO3 , and P04 are measured by automated colorimetric techniques. 

Bullock Jr, OR, Brehme KA. 2002. Atmospheric mercury simulation using the CMAQ model formulation description and analysis of wet deposition results. Atmos Environ 36 2135-2146. 

Archer, J. S. On-line analysis of wet combustion gases by gas chromatography. J. 

The attractiveness of surface/pore characterization via NMR spin-lattice relaxation measurements of pore fluid lies in the potential advantages this technique has as compared to the conventional approaches. These include rapid analysis, lower operating costs, analysis of wet materials, no pore shape assumption, a wide range of pore sizes can be evaluated (0.5 nm to >1 /im), no network/percolation effects and the technique is non-destructive. When determining specific surface areas, NMR analysis does not require out-gassing and has the potential for on-line analysis of slurries. 

ASTM C285-88 (Re-approved 1994) Standard test method for sieve analysis of wet milled and dry milled porcelain enamel, for determination of the fineness of frit in wet-or dry-milled porcelain enamels and other ceramic coatings on metals by use of the number 200 or No 325 mesh, 212 ASTM C925-79 (Re-approved 1995) Standard test method for precision electroformed wet sieve analysis of non-plastic ceramic powders, for particle size distribution determination ofpulverized alumina and quartz for particle sizes from 45 pm to 5 pm by wet sieving, 212, 230... 

Einfeldt, J., Meipner, D., Kwasniewski, A., and Einfeldt, L. Dielectric spectroscopic analysis of wet and well dried starches in comparison with other polysaccharides, Polymer, 42, 7049, 2001b. 

Calorimetric Studies of Water-Polymer Interactions. Additional information concerning water-polymer interactions was obtained through analysis of wet copolyoxamide samples by differential scanning calorimetry. Calorimetric experiments were performed both on polymer powders and on porous polymer films, with primary attention given to p-222I. 

Uytterhoeven MG, Schoonheydt RA (1993) Probing the synthesis of CoAPO-n molecular sieves by analysis of wet precm-sor gels. In von BaUmoos R, Higgins JB, Treaty MMJ (eds) Proceedings from the Ninth International Zeolite Conference. Butterworth-Heine-mann, Boston London Oxford Singapore Sydney Toronto Wellington, vol I, p 329 Han H-S,Chon H (1994) Stud Surf Sci Catd 84 797... 

Our target is to ultimately fabricate reactive micro- and nanopatterns for the area-selective immobilization of biologically relevant molecules via covalent coupling. In addition to full control of reactivity and pattern sizes, biocompatibility and minimized NSA are important for rendering these systems useful as generic platforms. In this context we review in this contribution our recent efforts in this area. We focus in particular on (1) the elucidation of structure-reactivity relationships, (2) the in situ compositional analysis of wet chemical reactions in monolayer-based systems down to nanometer length scales, and on (3) the application and refinement of various micro- and... 

Beerbom, M., O. Henrion, A. Klein, T. Mayer, and W. Jaegermann (2000). XPS analysis of wet chemical etching of GaAs(llO) by Br-2-H20 Comparison of emersion and model experiments. Electrochim. Acta 45, 4663-4672. 

Although the mathematical relationships encountered in wetting phenomena are usually quite simple, they are found to be very useful in many practical applications. Their combinations and variations have given rise to still more relationships, which further expand their utihty without expanding the amount of information necessary for their application. Two thermodynamic relationships that can be useful in the analysis of wetting and spreading phenomena are the works of cohesion and adhesion. 

Olaofsson K, Manufacturing analysis of wet filament winding, 2nd International Convention for Filament Winding Technology, Brussels, Oct 17-19, 2001. 

Traditional electron microscopy is conducted in high vacuum, which imposes specific efforts to sample preparation. Particles from colloidal suspensions have to be deposited onto an appropriate substrate (e.g. on carbon or silica films) and dried. Alternatively, the suspensions can be shock-freezed and particles are subsequently excavated from the continuous phase by special cryo-preparation techniques (Schmidt et al. 1994, pp. 694—705). The sample preparation can be considerably reduced with environmental scanning electron microscopes (ESEM), which are operated up to 1000 Pa and, thus, even facilitate the analysis of wet surfaces. However, the ease in operation is at the expense of resolution (Danilatos 1993). 

Computational Analysis of Wetting on Hydrophobic Surfaces Application to Self-Cleaning Mechanisms... 

The linear stability analysis of wetting films was first performed for surfactant-fi-ee films by Jain and Ruckenstein [553] and this analysis was further extended to surfactant containing films by Edwards et al. [58]. 

For thermal analysis of wet fabrics, the liquid is water and the gas is air. Evaporation or condensation occurs at the interface between the water and air so that the air is mixed with water vapor. A flow of the mixture of air and vapor may be caused by external forces, for instance, by an imposed pressure difference. The vapor will also move relative to the gas by diffusion from regions where the partial pressure of the vapor is higher to those where it is lower. 

Fowkes (1962, 1963, 1964, 1967) provided another approach for the analysis of wetting experiments by proposing that a surface tension y (soKd or liquid) may be expressed as the sum of a number of various components ... 

The role of water for chemically reactive membranes logically addresses the question of the influence of humidity on membrane separation performances. It has been stated before that, while flue gases are systematically wet, CO2/N2 separation studies by membrane materials most often report on dry mixtures. Apart from chemically reactive and liquid membranes, the analysis of wet CO2/N2 mixtures by dense polymers has been indeed seldom reported. It might be anticipated, however, that the presence of water will have a signiflcant impact in terms of separation performances. First, water can play a signiflcant role in terms of plasticization for glassy membrane materials. Even though most membrane materials for CO2 capture are of rubbery type, major modiflcations could occur compared to the dry mixture results. 

FTIR is especially useful for the characterization of surface species and the state of adsorbed molecules. A study of supported oxide catalysts involving FTIR and adsorption measurements is reported by Rives and his co-workers and the use of FTIR as an ancillary technique is referred to in several other papers. NMR measurements have been carried out in the context of image analysis (NMRI) of pore structures (Ewing et al), determination of dlffusivities of adsorbed species (Bahceli et al) and the pore structural analysis of wet materials (Smith and Davis). 

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