Of moving particle

The Mechanism of Electrical Conduction. Let us first give some description of electrical conduction in terms of this random motion that must exist in the absence of an electric field. Since in electrolytic conduction the drift of ions of either sign is quite similar to the drift of electrons in metallic conduction, we may first briefly discuss the latter, where we have to deal with only one species of moving particle. Consider, for example, a metallic bar whose cross section is 1 cm2, and along which a small steady uniform electric current is flowing, because of the presence of a weak electric field along the axis of the bar. Let the bar be vertical and in Fig. 16 let AB represent any plane perpendicular to the axis of the bar, that is to say, perpendicular to the direction of the cuirent. 

Light has a dual character - it may be described either as a wave motion or as a stream of moving particles. Since light is a form of electromagnetic radiation, its properties, as with all forms of electromagnetic radiation, are... 

In this chapter, we consider reactors for fluid-solid reactions in which the solid particles are in motion (relative to the wall of the vessel) in an arbitrary pattern brought about by upward flow of the fluid. Thus, the solid particles are neither in ideal flow, as in the treatment in Chapter 22, nor fixed in position, as in Chapter 21. We focus mainly on the fluidized-bed reactor as an important type of moving-particle reactor. Books dealing with fluidization and fluidized-bed reactors include those by Kunii and Levenspiel (1991), Yates (1983), and Davidson and Harrison (1963). 

After introducing some types of moving-particle reactors, their advantages and disadvantages, and examples of reactions conducted in them, we consider particular design features. These relate to fluid-particle interactions (extension of the treatment in Chapter 21) and to the complex flow pattern of fluid and solid particles. The latter requires development of a hydrodynamic model as a precursor to a reactor model. We describe these in detail only for particular types of fluidized-bed reactors. 

It is also feasible to measure both droplet size and velocity simultaneously with the holographic method. Such a measurement system has been developed by Murakami and Ishikawa. 65()l They used two pulse lasers of different wavelengths to record two holograms on two different films, separated by an appropriate time interval. The displacements of moving particles were measured on a superimposed picture of the two films to determine the velocities of the particles. 

Some qualities of light are best explained if we describe it as consisting of moving particles, often called photons or quanta (called the particle theory of light). Other qualities are best explained if... 

The de Broglie relationship states that any beam of moving particles will display wave properties according to the formula... 

In Chapter 2, Eqs (2-9) to (2-11) giving the terminal velocity of particles may be used to calculate the velocities required to move such particles through vertical pipes. The velocities calculated by these formulas are those required to support the particles in a vertical fluid stream. Motion in the direction of the moving stream will be imparted when the velocities exceed the calculated amounts. Little is known with regard to velocities for horizontal transportation of particles. In general, velocities capable of moving particles vertically will be more than sufficient for horizontal transportation. 

J. Cl. Maxwell [l] Illustrations of the dynamical theory of gases, Part 1 On the motions and collisions of perfectly elastic spheres, Phil. mag. (4) 19 (1860), p. 19 Part 2 On the process of diffusions of two or more kinds of moving particles among one another, Phil. Mag. (4) 20 (1860), p. 1 (also Scientific Papers 1, Cambridge 1890, p. 377). 

The internal spout consists of two cavities which are symmetrically located about the gas orifice axis, and are delimited by two rings of moving particles, the particle flow lines being similar to those for a pair of vortices in a continuous medium. 

SPT is the preferred teclmique when more detail on different populations of moving particles in a heterogeneous system is required. Although the information content of SPT is much higher than that of FRAP, it is much more demanding on... 

Describe de Broglie s revolutionary concept involving the characteristics of moving particles. (5.2)... 

Position in phase space is the 6N-dimensional point q = (r, p ). Phase point velocity is u = q = The flnx of moving particles (number of particles going through a unit area... 

In a classical system of moving particles the magnitude of the flux vector is the number of particles going per unit time through a unit area perpendicular to that vector. If p(r) and v(r) are the density and average speed of particles at point r, the flux is given by... 

If a student does not believe that sunrays absorb a puddle (see Sect. 2.1), he or she can then, using the particle model of matter with the idea of moving particles, successfully develop a scientific concept about the evaporation of water. There is an extension of the already established particle concept taught in lessons before - a conceptual growth appears. 

Gupalo, Yu. P., Polyanin, A. D., and Ryazantsev, Yu. S., Mass transfer interaction of moving particles in a reactive dispersive system, Acta Astronautica, Vol. 5, pp. 1213-1219, 1978. 

The Proton. The discovery of the electron was followed by a search for its positive counterpart. It was by using a vacuum tube fitted with a perforated cathode (Fig. 1) that Sir J. J. Thomson was able to obtain evidence for the existence of positive rays and to show that these too seemed to consist of moving particles. He found that for these particles the ratio of charge to mass (ejm) was not constant as it had been for electrons but depended on the nature of the gas present in the... 

A number of methods for the determination of electrophoretic velocity and electrokinetic potential of particles have been developed. These methods include the moving boundary method (a direct study of motion of the boundary between the disperse system and the free dispersion medium due to the applied potential difference), microelectrophoresis (a direct observation of moving particles using a microscope or ultramicroscope), electrophoresis in gels, paper electrophoresis, etc [ 13]. These methods are broadly used to study disperse systems formed with low molecular weight substances, as well as polymers, especially those of natural origin. Electrophoretic methods allow one to separate and analyze mixtures of proteins, and thus are effectively used in scientific research and medical diagnostic applications. 

Interference is the phenomenon that distinguishes waves from matter. While waves can interfere with one another in a constructive (when the superposition of the waves add up) or destructive (when the superposition of the waves cancel each other) manner, matter cannot. It was thus reasonable for many scientists of the seventeenth and eighteenth centuries to describe light either in terms of moving particles or of waves. ... 

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