Influence dispersion

The new route (process C) for manufacturing acrylic based polymers seems very promising. Polymers prepared by this way attain the efficiency of the best dispersants on the market. In the future, we will explore this route, improving parameters which are known to influence dispersant efficiency such as molecular... 

Once the mathematical description of dispersion has been clarified, we are left with the task of quantifying the dispersion coefficient, Eiis. Obviously, Edh depends on the characteristics of the flow field, particularly on the velocity shear, dvx/dy and dvx /dz. As it turns out, the shear is directly related to the mean flow velocity vx. In addition, the probability that the water parcels change between different streamlines must also influence dispersion. This probability must be related to the turbulent diffusivity perpendicular to the flow, that is, to vertical and lateral diffusion. At this point it is essential to know whether the lateral and vertical extension of the system is finite or whether the flow is virtually unlimited. For the former (a situation typical for river flow), the dispersion coefficient is proportional to (vx )2 ... 

Canevari, G.P. Basic Study Reveals How Different Crude Oils Influence Dispersant Performance in Proceedings of the Oil Spill Conference API Publication 4452, American Petroleum Institute Washington, DC, 1987,... 

Arvidsson, M., Merlind, P. K., Hynen, A., and Bergman, B. (2001). Identification of factors influencing dispersion in split-plot experiments. Journal of Applied Statistics, 28, 269-283. 

To achieve best jetness, a formulator would select a grade having very fine particles (high surface area) and a moderate structure (Table 11.1). As mentioned before, this is because small prime particles provide greater overall surface area to both absorb and scatter visible light, and moderate to high structure positively influences dispersion. 

In the presence of mountains and sloping terrain the wind speeds can be lower, especially at night. Buoyancy forces tend to dominate over inertial effects so that F < 1, leading to marked diurnal variations in the wind speed and direction, over the urban area and outside it. Such areas are associated with sudden changes in the airflow, internal fronts and pooling of the air in valleys, all of which greatly influence dispersion of air pollution and products from accidental releases (Hunt, Fernando and Princevac, 2003 [297]). 

Table 2 also shows that the resulting Rh dispersion is not a fimction of the metal loading but of the structure of the support [12,13], The natme of the support influences dispersion and therefore the size of the metallic particles. There was no correlation between metallic load and dispersion. Lamellar structures (BENa and BENPIL) incorporated larger amounts of rhodium complex but had lower dispersion than the catalysts synthesized on zeolitic products. The influence of the support structure is also reflected in the results for the zeolitic product synthesized with different treatment conditions or in different media, which determine the channel dimensions and the number of anchoring centres in the resulting samples. Higher dispersion was achieved in the more transformed samples, ZE— P, than in ZE—X, and in those synthesized in distilled water (ZEDI-) than in sea water medium (ZESE-). 

Sample introduction into a carrier stream generates a dispersing sample zone and each of its fluid elements is carried along at a velocity corresponding to its respective position in the stream. Convective mass transport is then a consequence of the parabolic distribution of the linear velocities of every fluid element (Fig. 3.1, upper). Diffusive mass transport is dependent mainly on the concentration differences between neighbouring fluid elements and their diffusion coefficients. Although diffusive mass transport occurs in an isotropic fashion, only its radial component is relevant as a factor influencing dispersion. 

At this point, it is noteworthy that without the resin fraction, asphaltenes are generally nondispersible in the remainder of petroleum, thereby indicating that the resins are, under ambient conditions, a necessary constituent and that by their presence they prevent incompatibility (3,4). This is only one of several factors that influence dispersibility or compatibility, and others will be noted, in turn, throughout the chapter. 

Lastly. ASTM D3313 for carbon black pellet hardness does not directly measure carbon black dispersion. This method does measure the individual carbon black pellet "hardness" or crush strength. Carbon black pellets that are too hard will not break up during mixing or disperse properly. Therefore by controlling the pellet hardness of carbon black, one cause of poor dispersion can be controlled. However, there are many other variables that influence dispersion as well. New sophisticated instruments arc now available for measuring carbon black pellet crush strength. 

Storage Reclose containers immediately after use separation and turbidity may occur during storage/transport warm to 30-60 C and mix before use prod, efficiency is not influence Disperse-Ayd 1 [Elemenlis Spec. U.S.]... 

Effectiveness of Dispersants. Dispersant effectiveness is defined as the amount of oil that the dispersant puts into the water column compared to the amount of oil that remains on the surface. In the field, effectiveness is indicated by the formation of a white to coffee-coloured plume of dispersed oil in the water column which is visible from ships and aircraft. This is shown in Figure 1. Many factors influence dispersant effectiveness, including oil composition, sea energy, state of oil weathering, the type of dispersant used and the amount applied, temperature, and salinity of the water. The most important of these is the composition of the oil, followed closely by sea energy and the amount of dispersant applied. 

Figure 5.1 Materials and processing parameters influencing dispersion of particulate...

There are four fundamental properties of carbon blacks which determine how these materials can be used with optimization. One Fineness and particle size distribution (Figure 2.39) influence blackness and tint. Two Structure within the carbon black particle and the aggregation of the particles (also called structure. Figure 2.39) influence dispersibility and electrical conductivity. Three Porosity and pore-size distributions influence viscosity and coverage requirements. Four The presence of surface functionality influences wettability, viscosity and electrical conductivity. In carbon black usage, it is their external surfaces, with oxygen functionality in some cases, which dominate their sorption properties, as distinct from the internal microporosity as found in activated carbon. Carbon blacks are supplied by manufacturers both as powders and as pellets. 

It can be demonstrated that not only the average molecular weight characteristic of a given polymer system influences dispersant efficiency, but also the polydispersity within any molecular weight range ... 

Emulsions of different oils in ternary HPMC/NaCMC/SDS mixture having 0.7% HPMC, 0.3% NaCMC and three characteristic SDS concentrations i.e. 0.00% (no HPMC-SDS complex formation), 0.35% (maximum of HPMC/SDS interaction), 1.00% (end of HPMC-SDS interaction) were prepared and spray dried. Dispersion properties (mean diameter and standard deviation) of the emulsions and suspensions of microcapsules in water are shown in Table 1. As it can be seen in Table 1 oil type influences dispersion properties of emulsions, and thus suspensions. Largest droplet diameter in all emulsions is obtained at 0.00% SDS, i.e. where no HPMC/SDS complex and coacervate formation takes place. On the other hand, largest diameter of suspended microcapsules occurs at 1.00% SDS. 

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