Distribution homogeneity

Figure 4. Monomer density profile Pn,(y) normalized such that p ,(y) = 1 if the monomers were distributed homogeneously in the simulation box plotted vs. y at various values of s/ksT from e/ksT = 0.1 (circles to s/kfiT = 0.019 (erosses). Data are for a symmetrical AB polymer mixture with Na = Nb = N = 32, the interface occurring at y = 0. From Miiller et al." ...

For the sake of simplicity we can assume that initially the heights of barriers are distributed homogeneously over the interval A = 4o 5) ... 

Similar to our previous reasoning, we can assume that are distributed homogeneously over interval obtain for the... 

This involves a chemical change. It is required that any decomposition procedure should alter the original environment of the sample into a digest, i.e. a solution in which the analyte is distributed homogeneously. More specific conditions set to a decomposition technique are [4] ... 

Loss of water and other volatile vehicle components Phase distribution (homogeneity or phase separation, bleeding)... 

Poisoning curves for porous catalysts. Curve A is for a porous catalyst with hT very small and poison distributed homogeneously. Curve B is for large hT with the poison distributed homogeneously. Curves C and D correspond to preferential adsorption of poison near the pore mouths. For curve C, hT = 5, and for curve D, hT = 20. 

For uniformly distributed homogeneous flows, the fluid properties can be described in terms of averages over the flow cross section. Such flows can be described as one dimensional, as opposed to separated or heterogeneous flows, in which the phase distribution varies over the cross section. 

Nanoparticles of dilute magnetic semiconductors have also been studied by NMR. Here one important question is whether the magnetic ion is incorporated into the NC or resides on the surface. The 113Cd MAS-NMR of NCs of Cd0.991Co0.009S with diameters from 3.5 to 29.5 nm showed peaks shifted by electron hyperfine interactions from next-nearest neighbor Co2+ ions, and by comparison with results from bulk samples that were discussed in Sect. 3.5 it was concluded that Co2+ ions occupied Cd2+ sites and were distributed homogeneously ... 

It is assumed that all chains are oriented parallel to the fibre axis and that equal parts of the fibre contain equal numbers of starting points of chains of arbitrary length u. Thus the starting points are distributed homogeneously along the length of the fibre. The length distribution of the chains is determined by the distribution function /( ) with... 

Uranium is distributed uniformly within individual growth layers, but varies greatly in concentration between successive layers (A, B, and C). The distribution of tracks suggests that U is distributed homogeneously in single calcite crystals, and is not concentrated at grain boundaries or in inclusions. 

It is assumed that the metals are distributed homogeneously in the water column as well as in the upper sediment layer. In both compartments, the metals can exist in either a dissolved form or as adsorbed to solid particles. 

The formation of graft copolymers leads to the possibility of combining incompatible polymers in such a way that the components may be distributed homogeneously or they are at least firmly fixed to each other at the phase boundaries, for example, with high-impact polystyrene, where the two components, polystyrene, ( 90%) and rubber ( 10%), are combined through... 

The effects of liquid fuel pulsation without air forcing were visualized at four instances of time (images not included). At time 0, a high concentration of fuel became visible at the nozzle exit. At time 7t/2, the fuel droplets became evenly dispersed through the quarter cycle. Times tt and 37t/2 showed similar droplet distributions, homogeneous throughout the flow. 

Under FCCU operating conditions, almost 100% of the metal contaminants in the feed (such as nickel, vanadium, iron and copper porphyrins) are decomposed and deposited on the catalyst (2). The most harmful of these contaminants are vanadium and nickel. The deleterious effect of the deposited vanadium on catalyst performance and the manner in which vanadium is deposited on the cracking catalyst differ from those of nickel. The effect of vanadium on the catalyst performance is primarily a decrease in catalyst activity while the major effect of nickel is a selectivity change reflected in increased coke and gas yields (3). Recent laboratory studies (3-6) show that nickel distributes homogeneously over the catalyst surface while vanadium preferentially deposits on and reacts destructively with the zeolite. A mechanism for vanadium poisoning involving volatile vanadic acid as the... 

It is obvious that in an OLED efficient charge injection is crucial. A simple estimate will illustrate this. Suppose that a concentration n of charge carriers equivalent to the capacitor charge CV, where C is the capacitance per unit area and V is the applied voltage, is distributed homogeneously within a dielectric layer... 

A constant total shear S suggests that the profiles of the material in the two different size screw extruders are identical or that the material distribution (homogeneity) in the extruder is independent of screw speed. In a similar manner, scale-up factors for power consumption, specific energy consumption, throughput rate, etc. have been compiled in the literature (21,22). 

The common aim of the Raman and NIR spectroscopy examples below was to display the API and excipient localization on the tablet surface in order to assess distribution homogeneity and characterize the solid-state properties of the API. 

Another result of the requirements to distribute homogeneous test material is that some pretreatment steps usually performed on routine samples are not done on the interlaboratory sample. For example, in interlaboratory rounds for the determination of metals by inductively coupled plasma, the test material is often a solution of the metals in water. Often a method requires extraction of the metals by acid digestion of the field sample, a procedure that will have significant uncertainty in terms of recovery of analyte. 

Fig. 17. Picture of the reduction process of a singly promoted iron catalyst, (a) Unreduced large catalyst particle with the promoter distributed homogeneously, (b) Catalyst after short reduction. Aluminum-rich regions appear, (c) Catalyst after further reduction consists of a-Fe and FcA1204 inclusions, (d) Fully reduced catalyst consists of small a-Fe particles with A1203 inclusions. Figure according to Tops e et al. (95).

In the case of a distributed system we need to establish the mass-balance for a small element AV and then take liniAV o to arrive at a DE, as detailed for distributed homogeneous systems earlier in Chapter 4 and depicted in Figure 6.11. 

For the evaluation of the non-faradaic component of the response in a more realistic way, different proposals have been made. A useful idea is that corresponding to the interfacial potential distribution proposed in [59] which assumes that the redox center of the molecules can be considered as being distributed homogeneously in a plane, referred to as the plane of electron transfer (PET), located at a finite distance d from the electrode surface. The diffuse capacitance of the solution is modeled by the Gouy-Chapman theory and the dielectric permittivity of the adsorbed layer is considered as constant. Under these conditions, the CV current corresponding to reversible electron transfer reactions can be written as... 

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