Solid distribution visualization

Visual observation of the entrainment region, with the use of a high speed video camera, has allowed a careful interpretation of the trends in the results. In particular, the solids circulation rates have been correlated with the size and stability of the jet, forming over the entrainment region. Also, non-uniformities of the solids distribution within the spouting jet have been studied. 

The nervous system contains an unusually diverse set of intermediate filaments (Table 8-2) with distinctive cellular distributions and developmental expression [21, 22]. Despite their molecular heterogeneity, all intermediate filaments appear as solid, rope-like fibers 8-12 nm in diameter. Neuronal intermediate filaments (NFs) can be hundreds of micrometers long and have characteristic sidearm projections, while filaments in glia or other nonneuronal cells are shorter and lack sidearms (Fig. 8-2). The existence of NFs was established long before much was known about their biochemistry or properties. As stable cytoskeletal structures, NFs were noted in early electron micrographs, and many traditional histological procedures that visualize neurons are based on a specific interaction of metal stains with NFs. 

This need is addressed in part by NIR-CI, in that it offers the ability to obtain high fidelity, spatially resolved pictures of the chemistry of the sample. The ability to visualize and assess the compositional heterogeneity and structure of the end product is invaluable for both the development and manufacture of solid dosage forms. NIR chemical images can be used to determine content uniformity, particle sizes and distributions of all the sample components, polymorph distributions, moisture content and location, contaminations, coating and layer thickness, and a host of other structural details. "... 

Chemical compound homogeneity is an important issue for pharmaceutical sohd forms. A classical spectrometer integrates the spatial information. In solid form analysis, use of a mean spectrum on a surface can be a drawback. For example, in the pharmaceutical industry it is important to map the distribution of active ingredients and excipients in a tablet so as to reveal physical interaction between the compounds and help to solve homogeneity issues. Spectroscopic imaging techniques that visualize chemical component distribution are thus of great interest to the pharmaceutical community. 

The mechanism by which equilibrium is attained can only be visualized in terms of microscopic theories. In the kinetic sense, equilibrium is reached in a gas when collisions among molecules redistribute the velocilies lor kinetic energies) of each molecule until a Maxwellian distribution is reached for the whole bulk. In the case of the trend toward equilibrium for two solid bodies brought into physical contact, we visualize the transfer of energy by means of free electrons and phonons (lattice vibrations). 

NaCl The bond in solid sodium chloride is a largely ionic one between Na+ and Cl-. In spite of what we ve said previously, though, experiments show that the NaCl bond is only about 80% ionic and that the electron transferred from Na to Cl still spends some of its time near sodium. A particularly useful way of visualizing this electron transfer is to represent the compound using what is called an electrostatic potential map, which uses color to portray the calculated electron distribution in the molecule. The electron-poor sodium atom is blue, while the electron-rich chlorine is red. 

The most important structural features of amorphous SAN copolymers are the weight fraction (h an) of acrylonitrile and the molecular weight distribution (MWD). These features control the solid-state properties and fabrication performance. Also important are the type and level of conjugated chromopores and the monomer sequence distribution. These features control the visual appearance of the SAN copolymer. The chromophores may introduce unwanted yellowness. A nonuniform sequence distribution may cause unwanted haze from phase separation. 

The efficiency with which substances from the surrounding atmosphere are absorbed and distributed in the drop depends on the degree of mixing within the drop. Movement inside the drop can be observed in two ways, namely by suspending solids (e.g. aluminium oxide particles) in the levitated drop and by spiking the drop with a highly concentrated dye solution. In both cases, the speed and the pattern of the distribution inside the drop can be visually observed. 

When a fluid flows across a solid surface, the drag (the resistance to flow) produced by the presence of the surface in contact with the fluid creates a velocity distribution through the bulk fluid. The fluid velocity increases with the distance from the solid surface. The flow may be visualized by so-called streamlines that represent the paths of parcels of fluid. Each streamline represents fluid with the same velocity. Fig. 1 shows the velocity profile with a fluid flowing across a solid surface. The difference in flow rate between adjacent streamlines is always the same when the streamlines are equidistant. 

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