Mass uniformity

The use of highly dispersed metals at low concentration levels has found wide use In Industry, particularly for electronic and catalytic uses. The desire to optimize the size and mass uniformity of these metal particles Is of particular Interest. Characterization of these materials Is difficult especially when metal particle sizes are on the order of 5 nm or less and concentrations are below 1 wt-Z. Development of highly sophisticated techniques In recent years has provided new approaches to understanding the physical and chemical properties of these materials. Electron microscopy has proven quite valuable In the acquisition of data and subsequent generation of information, which Is necessary to understand the physical-chemical properties of Individual nm-slzed particles. 

This Study has shown that reasonably uniform platinum crystallites can be made on y-alumlna, and that platinum and palladium can be segregated and maintained In that form for the most part even after exposure to high temperature oxidation-reduction conditions. Highly dispersed clusters of palladium, nickel, cobalt, and Iron can be observed. Cluster size determination could not be accurately made because of the lack of contrast between the cluster and the support. The marginal detectability by EDS for these clusters enabled elemental Identification to be made, however, mass uniformity determinations could not be made. 

Thus, the normal component of the attraction field caused by masses uniformly distributed on the planar surface can be expressed as... 

Coating Mass Uniformity and Distribution. Basically, there have been two approaches to model the accumulation of mass (coating material) on the surface of bed particles (i) the use of population balances and (ii) the probabilistic modelling of the spray-particle interaction. We will look at each of these approaches and see how it may be possible to combine these methods to give a fuller picture of coating performance. 

In a modification of this process, a wet mixture of sawdust or peat and magnesium carbonate is subjected to the action of carbon dioxide under pressure. A soluble bicarbonate is produced which penetrates the mass uniformly. After activation, the magnesium oxide remaining in the char can be extracted for re-use with water and carbon dioxide under pressure. 

The physical parameters of the process are monitored in normal production runs to obtain additional information on the process and its reliability. Extra temperature-sensitive devices installed in an autoclave or dry-heat sterilizer (in addition to probes used routinely) will permit an in-depth study of the heat distribution for several loads. Heat-penetration measurements are recommended for injectable products of higher viscosity or with volumes larger than 5 ml. A tableting press equipped with pressure-sensitive cells will be helpful in collecting statistical data on the uniformity of die-fill and therefore on mass uniformity. 

Prior to measurement, the separated and purified plutonium must be incorporated into a source to produce a low mass, uniformly distributed deposit on a highly polished metal surface. Two techniques that are commonly used are (1) electrodeposition, and (2) co-precipitation with a carrier. 

These temperature phenomena and facts and regularities for the continental grounds, the atmospheric air and the oceanic seawater can demonstrate that the temperature changes are dominantly controlled by the heat from the Sun and the stable temperatures are controlled by the constant heat from the interior of the Earth. Such results can demonstrate that there is a mechanism between the crust and the mantle to keep the heat transfer from the hot mantle materials to the crust rock masses uniformly and constantly. This mechanism is the thin spherical gas layer as a heat insulation seam between the crust and mantle. 

Profiling in this manner is not limited to thickness alone. A good case can be made for the importance of mass uniformity in many tapes. Systems actually exist in which mass uniformity is a more critical parameter than thickness uniformity. Regardless of the system, mass uniformity within a cast layer has great importance, since it affects shrinkage uniformity, density gradients, warpage, electrical properties and the like. 

The nonwoven fabric uniformity is originally defined as the fabric mass per unit area (or fabric density) distribution in the fabric structure. The basic statistic terms of fabric mass uniformity in nonwoven industries are the standard deviation (measured parameters (eg, fabric weight, fabric thickness, fabric density, optical levels, rays absorption amounts, grey level intensity of images, etc.) as follows ... 

The fabric uniformity is anisotropic, ie, the uniformity is different in different directions in fabric structures, notably, in machine direction (MD) and cross direction (CD). The ratio of the index of dispersion was roughly used to represent the anisotropy of uniformity. The local anisotropy of nonwoven fabrics mass uniformity has also been defined by Scharcanski and Dodson in terms of local dominant orientations of fabric weight. 

The displacement capacities are computed from the capacity curve obtained for the building, which presents the evolution of the base shear force (horizontal force representative of the seismic action) against the displacement of a control point (significant point of the structure, usually the centroid of the roof slab), e.g., in Fig. 6. This curve is computed by applying an incremental lateral static loading on the structure, which is processed with force and/or displacement control, and for which two load distribution patterns are usually assumed proportional to the inertial masses multiplied by the displacements of the first vibrational mode of the structure (modal distribution) and proportional to the inertial masses (uniform distribution). 

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