Particle comment

Using this definition of the Thiele modulus, the reaction rate measurements for finely divided catalyst particles noted below, and the additional property values cited below, determine the effectiveness factor for 0.5 in. spherical catalyst pellets fabricated from these particles. Comment on the reasons for the discrepancy between the calculated value of rj and the ratio of the observed rate for 0.5 in. pellets to that for fine particles. 

If the component analysed represents 20 per cent of the mixture by mass and each of the samples removed contains approximately 100 particles, comment on the quality of the mixture produced and present the data in graphical form showing the variation of mixing index with time. 

Membrane-mimetic compartment Incorporated particles Comments Reference... 

Size p Shape Major Minor Trace No. Particles Comments... 

We will almost always treat the case of a dilute gas, and almost always consider the approximation that the gas particles obey classical, Flarniltonian mechanics. The effects of quantirm properties and/or of higher densities will be briefly commented upon. A number of books have been devoted to the kinetic theory of gases. Flere we note that some... 

In the previous section, non-equilibrium behaviour was discussed, which is observed for particles with a deep minimum in the particle interactions at contact. In this final section, some examples of equilibrium phase behaviour in concentrated colloidal suspensions will be presented. Here we are concerned with purely repulsive particles (hard or soft spheres), or with particles with attractions of moderate strength and range (colloid-polymer and colloid-colloid mixtures). Although we shall focus mainly on equilibrium aspects, a few comments will be made about the associated kinetics as well [69, 70]. 

The number of C H2n+2 iso mers has been calculated for values of n from 1 to 400 and the comment made that the number of isomers of C167H336 exceeds the number of particles in the known universe (10 °) These obser vations and the historical background of isomer calcu lation are described in a pa per in the April 1989 issue of the Journal of Chemical Edu cat/on (pp 278-281)... 

In the last section we noted that Simha and others have derived theoretical expressions for q pl(p for rigid ellipsoids of revolution. Solving the equation of motion for this case is even more involved than for spherical particles, so we simply present the final result. Several comments are necessary to appreciate these results ... 

For the a-helix, the length per residue is about 1.5 A. Use this figure with the molecular weight to estimate the length 2a of the particle. Use the estimated a/b ratios to calculate the diameter 2b of the helix, which should be approximately constant if this interpretation is correct. Comment on the results. 

The letters a-g will be used in the references as brief symbols for indicating the main method used in a paper, and many papers are further characterized by one line comments. Even articles concerning the general theory for many-particle systems have been included. 

This account of the kinetics of reactions between (inorganic) solids commences with a consideration of the reactant mixture (Sect. 1), since composition, particle sizes, method of mixing and other pretreatments exert important influences on rate characteristics. Some comments on experimental methods are included here. Section 2 is concerned with reaction mechanisms formulated to account for observed behaviour, including references to rate processes which involve diffusion across a barrier layer. This section also includes a consideration of the application of mechanistic criteria to the classification of the kinetic characteristics of solid-solid reactions. Section 3 surveys rate processes identified as the decomposition of a solid catalyzed by a solid. Section 4 reviews other types of solid + solid reactions, which may be conveniently subdivided further into the classes... 

Friis and Hamielec (48) offered some comments on the continuous reactor design problem suggesting that the dispersed particles have the same residence time distribution as the dispersing fluid and the system can be modeled as a segregated CSTR reactor. 

Make sure that you specify all of the distribution parameters available for esch method. Comment on the efficiacy of the methods as applied to the study of particle size analysis. 

A comment regarding the dispersion of the Ru-Rh/Si02 and the Ru-Ir/Si02 is in order. For the case of the supported Pt-Ru catalysts. Increases in dispersion as a result of clustering were very large ( ). This effect was particularly noticeable for bimetallic particles which conform to the cherry model. Evidently, the formation of an inner core enriched in one of the two metals, followed by an outer layer enriched in the other metal, inhibits further crystal growth. For the alumina-supported Pt-Ru bimetallic clusters, the effect, although present, is considerably smaller. 

Certainly, the system of equations for the attraction field is much more complicated than that for the potential. Before we continue it may be appropriate to make the following comment. In all geophysical methods the fields, such as the particle displacement caused by elastic waves, the constant and time-varying electric... 

Horanyi G. 1985. Comments on the electrochemical behavior of small metal particles. J Phys Chem 89 2967-2968. 

Having acknowledged a qualitative agreement in experimentally determined change in a and p during adsorption of acceptor particles with theoretical predictions we should comment the correct choice of parameter toe expressions (1.81) and (1.83) makes it feasible to obtain a... 

Our comments on adsorption of oxygen and nitrogen atoms lead to conclusion that practically under all conditions the initial rate of variation of conductivity of zinc oxide film due to adsorption of acceptor particles discussed in this section is proportional to the concentration of particles in the space adjacent to the surface of oxide film. This is similar to the case of donor particles. This means that the following equation is applicable ... 

These are broadly in line with the comments of others, except that some hold the view that to obtain the densest possible bed structure the impinging particle must hit the accumulating bed with sufficient speed to forcibly displace those particles already in position [130,131,152-154]. The slurry is displaced into the... 

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