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Basic Concepts of Kinetic Theory

The time evolution of this phase space probability density is governed by the Liouville equation expressed as [Pg.207]

Various efforts along these lines have attempted to derive the Boltzmann equation from first principles. However, a number of assumptions come into play in all these derivations, which renders even the more formal analyzes somewhat ad hoc. Therefore, many practitioners do not consider the classical formalism worthwhile. [Pg.207]

In this section the statistical theorems or mathematical tools needed to understand the Boltzmann equation in itself, and the mathematical operations performed developing the macroscopic conservation equations starting out from the microscopic Boltzmann equation, are presented. [Pg.207]

Introductory it is stressed that a heuristic theory, which resembles the work of Boltzmann [6] and the standard kinetic theory literature, is adopted in this section and the subsequent sections deriving the Boltzmann equation. Irrespective, the notation and concepts presented in sect. 2.2 are often referred, or even redefined in a less formal wrapping, thus the underlying elements of classical mechanics are prescience of outmost importance understanding the true principles of kinetic theory. [Pg.208]


Chapter 2 contains a summary of the basic concepts of kinetic theory of dilute and dense gases. This theory serves as basis for the development of the continuum scale conservation equations by averaging the governing equations determining the discrete molecular scale phenomena. This method is an alternative to, or rather both a verification and an extension of, the continuum approach described in Chap. 1. These kinetic theory concepts also determine the basis for a group of models used describing granular flows, further outlined in Chap. 4. [Pg.1542]

The development of combustion theory has led to the appearance of several specialized asymptotic concepts and mathematical methods. An extremely strong temperature dependence for the reaction rate is typical of the theory. This makes direct numerical solution of the equations difficult but at the same time accurate. The basic concept of combustion theory, the idea of a flame moving at a constant velocity independent of the ignition conditions and determined solely by the properties and state of the fuel mixture, is the product of the asymptotic approach (18,19). Theoretical understanding of turbulent combustion involves combining the theory of turbulence and the kinetics of chemical reactions (19—23). [Pg.517]

Although the field of gas-phase kinetics remains hill of challenges it has reached a certain degree of maturity. Many of the fiindamental concepts of kinetics, in general take a particularly clear and rigorous fonn in gas-phase kinetics. The relation between fiindamental quantum dynamical theory, empirical kinetic treatments, and experimental measurements, for example of combustion processes [72], is most clearly established in gas-phase kmetics. It is the aim of this article to review some of these most basic aspects. Details can be found in the sections on applications as well as in the literature cited. [Pg.794]

Study, the students are taught the basic concepts of chemistry such as the kinetic theory of matter, atomic stmcture, chemical bonding, stoichiometry and chemical calculations, kinetics, energetics, oxidation-reduction, electrochemistry, as well as introductory inorgarric and organic chemistry. They also acquire basic laboratory skills as they carry out simple experiments on rates of reaction and heat of reaction, as well as volrrmetric analysis and qualitative analysis in their laboratory sessions. [Pg.138]

In Sections V and VI, a brief history of the developments of the MCT from the hydrodynamic approach (Critical Phenomena) and the renormalized kinetic theory approach has been presented. The basic concept of MCT is to use the product of the slow (hydrodynamic) variables to span the orthogonal subspace of the fast variables. [Pg.94]

The theory involves the basic concept of matter as composed atoms and/or molecules that move more rapidly (gases) or vibrate more energetically (solids) as temperature increaes. Thus, crystals melt at a point where the heat or energy input exceeds the bond energy of the solid state. See kinetics, chemical gas thermodynamics. [Pg.730]

Density Functions play a fundamental role in the definition of Quantum Theory, due to this they are the basic materials used in order to define Quantum Objects and from this intermediate step, they constitute the support of Quantum Similarity Measures. Here, the connection of Wavefunctions with Extended Density Functions is analysed. Various products of this preliminary discussion are described, among others the concept of Kinetic Energy Distributions. Another discussed set of concepts, directly related with the present paper, is constituted by the Extended Hilbert Space definition, where their vectors are defined as column structures or diagonal matrices, containing both wavefunctions and their gradients. The shapes of new density distributions are described and analysed. All the steps above summarised are completed and illustrated, when possible, with practical application examples and visualisation pictures. [Pg.1]

What are the basic postulates of kinetic molecular theory How does the concept of pressure follow from kinetic molecular... [Pg.238]

The explanation given for the growth rates of linear polyethylene is highly specific. Based on the successive modifications that have been made, there is a serious question as to whether the reptation concept, as it has been applied, has general applicability to the crystallization kinetics of polymers. If the basic ideas of reptation theory are appropriate, major alterations have to be made so that it explains the molecular weight dependence of all polymers. [Pg.201]

The concept of corresponding states was based on kinetic molecular theory, which describes molecules as discrete, rapidly moving particles that together constitute a fluid or soHd. Therefore, the theory of corresponding states was a macroscopic concept based on empirical observations. In 1939, the theory of corresponding states was derived from an inverse sixth power molecular potential model (74). Four basic assumptions were made (/) classical statistical mechanics apply, (2) the molecules must be spherical either by actual shape or by virtue of rapid and free rotation, (3) the intramolecular vibrations are considered identical for molecules in either the gas or Hquid phases, and (4) the potential energy of a coUection of molecules is a function of only the various intermolecular distances. [Pg.239]

This chapter treats the descriptions of the molecular events that lead to the kinetic phenomena that one observes in the laboratory. These events are referred to as the mechanism of the reaction. The chapter begins with definitions of the various terms that are basic to the concept of reaction mechanisms, indicates how elementary events may be combined to yield a description that is consistent with observed macroscopic phenomena, and discusses some of the techniques that may be used to elucidate the mechanism of a reaction. Finally, two basic molecular theories of chemical kinetics are discussed—the kinetic theory of gases and the transition state theory. The determination of a reaction mechanism is a much more complex problem than that of obtaining an accurate rate expression, and the well-educated chemical engineer should have a knowledge of and an appreciation for some of the techniques used in such studies. [Pg.76]

Although Theory and Modeling is more extensively discussed in Chapter 3, it is helpful to briefly discuss some basic concepts related to the accumulation of chemicals by SPMDs. Huckins et al. (1993) have shown that the uptake process obeys first-order kinetics (Figure 2.3). This type of exchange kinetics is characterized by half-lives (ti/2), which are constant for a particular set of conditions and... [Pg.36]

We can understand how atmospheric pressure is just the weight of the atmosphere pushing down on the Earth s surface, but how can we apply the basic definition of pressure to a confined gas To expand our concept of pressure and provide a basic framework for understanding the behavior of gases, we use a simple model for a confined gas. This model is known as the kinetic molecular theory. The kinetic molecular theory states ... [Pg.101]


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