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Subject Boltzmann constant

Boltzmann constant, and g, is a statistical weight for the ith excited state. The summation over all possible states is the electronic partition function. If the flame temperature is constant throughout the analysis, the signal level will be subject only to the amount of sample in this region. Thus the intermediate zone is usually aligned with the optical path and is of most importance for analytical measurements. However, this alignment of the optical path should also be optimized for the particular element to be quantitated. [Pg.429]

This method involves the numerical integration of the equations of motion (F = ma) for each of the molecules, subject to intermolecular forces, in time. The molecules are positioned arbitrarily in a simulation cell, that is, a three-dimensional cube, with initial velocities also specified arbitrarily. Subsequently, the velocities are scaled so that the summation of the kinetic energies of the molecules, 3NkTI2, gives the specified temperature, T, where W is the number of molecules and k is the Boltzmann constant. Note that after many collisions with the walls and the other molecules, the relative positions and velocities of the molecules arc independent of the initial conditions. [Pg.48]

A plastic which behaves like a Kelvin-Voigt model is subjected to the stress history shown in Fig. 2.87. Use the Boltzmanns Superposition Principle to calculate the strain in the material after (a) 90 seconds (b) 150 seconds. The spring constant is 12 GN/m and the dashpot constant is 360 GNs/m. ... [Pg.164]

Here, k is Boltzmann s constant, namely 1.39 10-16 ergs/deg. and N (E) is the number of independent ways in which the system of atoms may have the total energy E. The subject of quantum statistics is concerned with the detailed determination of the quantity N(E). [Pg.4]

Recall that Aj are positive integration constants. For open systems Ai is equal to the known concentration of the charge carrier t, wherever

closed systems, in which only the total number of charge carriers may be known rather than their concentration somewhere, the Ai are subject to determination in the course of the solution. (The properties of the solutions for parallel open and closed system formulations may differ quite markedly, as was exemplified in [1].) Equation (2.1.2), the Poisson-Boltzmann equation, is a particular case of the nonlinear Poisson equations... [Pg.23]

In the discussion of many properties of substances it is necessary to know the distribution of atoms or molecules among their various quantum states. An example is the theory of the dielectric constant of a gas of molecules with permanent electric dipole moments, as discussed in Appendix IX. The theory of this distribution constitutes the subject of statistical mechanics, which is presented in many good books.1 In the following paragraphs a brief statement is made about the Boltzmann distribution law, which is a basic theorem in statistical mechanics. [Pg.602]

It is not surprising that the approximate bounds give the correct time dependence for the free boundary motion, since X is identical, except for constant factors, with the Boltzmann similarity variable. For a block of ice whose surface temperature is subjected to a step increase of 5°C. the upper and lower bounds are within 3% of each other, and the approximate growth constant calculated from Eq. (238) is about 0.5% from the exact value. [Pg.124]

The physical basis of current MRI methods has its origin in the fact that, in a strong magnetic field, the nuclear spins of water protons in different tissues relax back to equilibrium at different rates, when subject to perturbation from the resting Boltzmann distribution by the application of a short radio frequency (rf) pulse. For the most common type of spin-echo imaging, return to equilibrium takes place in accord with equation 1 and is governed by two time constants T and T2, the longitudinal and transverse relaxation times, respectively. [Pg.430]

Show that the form of the Boltzmann principle given in equation (2-45) reverts to the defining equation for the shear creep compliance, equation (2-9), when a sample, initially at rest, is subjected to an instantaneous increment of stress at t = 0, which is thereafter held constant. [Pg.48]

The subject of statistical mechanics is a branch of mechanics which has been found very useful in the discussion of the properties of complicated systems, such as a gas. In the following sections we shall give a brief discussion of the fundamental theorem of statistical quantum mechanics (Sec. 49a), its application to a simple system (Sec. 496), the Boltzmann distribution law (Sec. 49c), Fermi-Dirac and Bose-Einstein statistics (Sec. 49d), the rotational and vibrational energy of molecules (Sec. 49e), and the dielectric constant of a diatomic dipole gas (Sec. 49/). The discussion in these sections is mainly descriptive and elementary we have made no effort to carry through the difficult derivations or to enter into the refined arguments needed in a... [Pg.395]

Lastly, as shown above, complexing reactions should be considered as subjected to the mass action law in consideration of the Boltzmann factor for the solution ions. The Boltzmann factor depends on charge of the inner-sphere complex, and for this reason the complex formation reaction s equilibrium constant (see equation (2.257)) may be determined from the following equation... [Pg.191]

C = a constant of proportionality subject to the conditions of a constant number of molecules and of constant energy k = Boltzmann s constant = R/Na = 1.38x10 J/K T = temperature (in imits of degrees Kelvin)... [Pg.391]

GPa, respectively, with relaxation time r 5 s. The pofymer is subjected to a constant rate of tensOe strain e = 10" s". Derive the stress-strain relation Boltzmann superposition principle. [Pg.183]

To begin with the fundamental analysis of EDL interactions, let us first consider the distribution of potential between two charged infinite parallel plates at a distance of 2H apart and subjected to constant surface potentials (refer to Eig. 1). Assuming a Boltzmann distribution of the respective ionic concentrations, one can write, for a symmetric 1 1 electrolyte (see entry Electrical Double Layers ),... [Pg.735]

Thermal noise Electric noise power that is due to heat It is equal to the product of Boltzmann s constant, the absolute temperature of the subject, and the operating frequency bandwidth. [Pg.505]

Technically, the Boltzmann distribution applies to particles in an ideal gas, not to molecules in crystal structures. However, we have considered the group of related molecules in crystals to be subject to random distortions from crystal packing effects in each separate crystal structure. The energies of the particles in the ideal gas depend on the temperature through Boltzmann s constant or the ideal gas constant. If a Boltzmann-type distribution holds for distortions in crystal structures, the actual value of the constant, or the effective temperature, is unknown. This subject is discussed further in French et. al. (2000). [Pg.276]


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Boltzmann constant

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