Dispersion behavior

The second process to finish phthalocyanine, which is more important for P-copper phthalocyanine, involves grinding the dry or aqueous form in a ball mill or a kneader (64). Agents such as sodium chloride, which have to be removed by boiling with water after the grinding, are used. Solvents like aromatic hydrocarbons, xylene, nitrobenzene or chlorobenzene, alcohols, ketones, or esters can be used (1). In the absence of a solvent, the cmde P-phthalocyanine is converted to the a-form (57,65) and has to be treated with a solvent to regain the P-modification. The aggregate stmcture also has an impact on the dispersion behavior of a- and P-copper phthalocyanine pigments (66). 

Colenbrander, G. W. and J. S. Puttock, 1983, Dense Gas Dispersion Behavior Experimental Observations and Model Developments, International Symposium on Loss Prevention and Safety Promotion in the Process Industries, Harrogate, England, September. 

Surface Chemical Aspects of Oil Spill-Dispersant Behavior... 

C. A. Christopher. Surface chemical aspects of oil spill dispersant behavior. In Proceedings Volume, pages 375-389.4th Annu Pennwell Conf Exhibit Co Petro (Safe 93) Conf (Houston, TX, 1/26-1/28), 1993. 

Horwatt, S. W Manas-Zloczower, I., and Feke, D. L., Dispersion behavior of heterogeneous agglomerates at supercritical stresses. Chem. Eng. Sci. 47, 1849-1855 (1992b). 

The dispersion model approach was first proposed to simulate dynamic absorption processes [49], The dispersion model assumes that the small intestine can be considered as a uniform tube with constant axial velocity, constant dispersion behavior, and uniform concentration across the tube diameter. Then the absorption of highly soluble drugs in the small intestine can be delineated by the following dispersion model equation ... 

C. Saltiel, Q. Chen, S. Manickavasagam, L. S. Schadler, R. W. Siegel, and M. P. Menguc, Identification of the dispersion behavior of surface treated nanoscale powders, J. Nanopart. Res. 6,35-46... 

In the preceding section, we emphasized that the surface interaction of metallic particles with liquid molecules is a very important parameter in the dispersion behavior of the sol. Since the surface nature is very sensitive to the surface modification, we can easily regulate it with the use of surfactant. As seen in Figure 9.4.23, almost all metallic particles cannot be dispersed in hexane as a suspension liquid. In this section, we show what kind of surfactant is effective in dispersion. The sample was prepared by the gas flow-cold trap method. We tested three surfactants, dimethyldi-... 

The dispersion behavior of organoclay affected the visual appearance of the hybrid composites (Fig. 6a, b). The composites containing Si particles predominantly as a finely dispersed phase were transparent, e.g., PNCI2 [nanocomposite prepared in... 

The effects of coupling of the DTO and RB units in not only one- but also three-dimensional arrays are discussed below and molecular weight trends illustrated. A fundamental connection between relaxation times and normal mode frequencies, shown to hold in all dimensions, allows the rapid derivation of the common viscoelastic and dielectric response functions from a knowledge of the appropriate lattice vibration spectra. It is found that the time and frequency dispersion behavior is much sharper when the oscillator elements are established in three-dimensional quasi-lattices as in the case of organic glasses. 

Table 6. Dielectric dispersion behavior in the continuum limit...

Comparison of the reduced loss compliance of the one- and three-dimensional arrays is made in Figs. 7 and 8 where Eqs. (T 6) and (T 12) are plotted on reduced frequency scales for a number of molecular weights. The dispersion behavior in the linear case becomes progressively broader with increasing molecular weight. In contrast, the three-dimensional loss profile remains quite sharp even for large molecular weights. 

In "open ends" operation dispersion exists before and after the measuring point. This mode may be used with tracer studies when tracer is injected and sampled some distances from the ends of the vessel for the purpose of making accurate measurements of dispersion behavior. The boundary conditions are... 

Characterizing Dispersibility and Dissolution/Dispersion Behavior of LBDDS. 242... 

Solution and Dispersion Behavior. For the dyeing process in aqueous liquor, the dye must have adequate solubility or dispersibility. In general, good solubility is necessary for good application properties. If the solubility is poor (i.e., if any of the dye is present in the dye liquor in the form of undissolved particles), local coloration (specks), spots, uneven effects, and poor fastness can be produced, leading to serious defects and costly complaints. 

Until a more detailed understanding of mating behavior, dispersal behavior and a complete identification of additional pheromone components is achieved, further field work on mating disruption with budworm can only proceed on an empirical basis. Additionally, treatment effects will be difficult to interpret unequivocally due to the local and long range movements of budworm adults into and out... 

Blends 3 (a,b,c) Rheologically Robust Matrix and Weak Dispersed Components Since PE 1409 is a low viscosity nearly Newtonian polymer melt, its dispersive behavior is uncomplicated and more Newtonian like. Blend 3a forms a small (3-5-pm) droplet dispersion morphology, and Blend 3b is even finer (1-2 pm), becoming, only below 2% concentration, less subject to flow-induced coalescence. The TSMEE-obtained dispersions are finer than those from the TSMEE, with a variety of kneading elements (126). What is noteworthy about these blends is the early stages of the dispersion process, shown on Fig. 11.44, obtained with Blend 3a using the TSMEE at 180°C and 120 rpm. 

The flocculation results on the individual mineral suspensions are shown in Figure 2 (A B). These graphs show the effect of polyacrylic acid dispersant before (PAA) Figure 2A, and after xanthation (PAAX) Figure 2B, on the flocculation-dispersion behavior of individual suspensions of coal and pyrite with Purifloc-A22 flocculant. 

Dilution is attributed to the large amounts of air that are entrained by the spray. As a result of air entrainment, dispersion behavior is altered for materials that exhibit negative buoyancy upon release. This is found to be effective in controlling flammability hazards that are located close to the release source. If an explosion does occur, some of the energy will be absorbed in the breakup of the water spray droplets, thereby mitigating the explosions impact. 

A simple concept can be used to illustrate important features of vapor barriers that alter cloud dispersion behavior in the near field (Meroney, 1991 Meroney and Neff, 1985). The concept is based on adding an entrainment velocity ( e) contribution, which is attributed to the vapor fence. 

Examples of values of Pe are provided in Fig. 19-8. When Pe is large, n =k Pe/2 and the dispersion model reduces to the PFR model. For small values of Pe, the above equation breaks down since the lower limit on n is n = 1 for a single CSTR. To better represent dispersion behavior, a series of CSTRs with backmixing may be used e.g., see Froment and Rischoff (Chemical Reactor Analysis and Design, Wiley, 1990). A model analogous to the dispersion model may be used when there are velocity profiles across the reactor cross-section (eg., for laminar flow). In this case, the equation above will contain terms associated with the radial position in the reactor. 

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