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Prescribed energy values

We have examined exact solutions, in the form of Kummer functions, that may be used to describe various forms of confinement to specific spatial regions. The definition of confinement has been enlarged from that used conventionally, and in all cases the physical aspects of the confinement are modeled by boundary conditions. These boundary conditions in some cases include prescribed energy values, but are mainly conditions on the wavefunction and its derivative on the boundary of the confined region. In this way the main aspects of the physics are modeled by the exact solutions found. However,... [Pg.198]

The regulations prescribe the energy values to be used as in Table 3. There are agreed values for some other materials. The synthetic dextrose polymer poly dextrose is accepted to be only 1 kcal g 1 (or 4 kJ g 1) even though it would otherwise fall within the definition of a carbohydrate. The accepted value for gum acacia, a polysaccharide obtained from trees of the species Acacia Senegal and closely related species, is 2 kcal g 1 (or 8 kJ g-1). [Pg.47]

At first sight, the principle of minimum entropy production, especially in the case of a continuous system, seems to have some intimate connection with the principle of least dissipation of energy. However, these two principles are of rather different characters. In the case of least dissipation of energy the flows are varied by keeping the intensive variables at every point constant, while the forces and flows are varied at the same time in accordance with the phenomenological relations under the prescribed boundary values in the case of the principle of minimum production of entropy. [Pg.302]

Therefore by (2.194) no conditions are to be imposed upon n on the boimdary except those dictated by the given anchoring alignment. This then makes it sufficient only to minimise the bulk energy subject to n taking prescribed fixed values on the boundary, that is, n = on the boundary for some fixed n. Two examples of... [Pg.47]

Minimum exposure times must be observed in order to reach the requisite S/N ratio. As per EN 1435 and EN 584-1, for the different ranges of utilization (energy, wall thickness), definite film elasses are prescribed. They are characterized by the minimum gradient-to-noise ratios. Based on this, one can calculate the minimum values for the S/N ratio based on the IP systems. The exposure time and the device parameter sensitivity and dynamics (latitude) must be adjusted accordingly, with an availability of an at least 12 bit system for the digitalization. [Pg.474]

For qualitative purposes the circle itself isn t even necessary We could locate the Huckel MOs by simply working with the polygons themselves The circle is needed only when Frost s method is used quantitatively In those cases the radius of the circle has a prescribed value allowing each MO to be assigned a specific energy... [Pg.452]

Part IV of this chapter will present the elementary theory of Second-Law cost accounting and its application to several practical cases, showing its usefulness for (i) costing "energy" commodities, (ii) plant operation decisions, and (iii) plant designs — new and retro-fit. These methods can be used to prescribe efficiencies and investments, traded-off against each other, but they will yield truly optimal results only to the extent that the real value (cost) of the "energy" supply is known. [Pg.33]

The matrix elements Hab.ca, Aat,ca are calculated using spin valence functions constructed from atomic orbitals. The energies E%, Ef, Ef, Ef are the exact values for the particular states of the participating atoms and may be taken from spectroscopic tables. The corresponding quantities E%, etc., with tildes are the values for these same spectroscopic states obtained from calculations using the orbital wavefunctions. In essence, equation (116) prescribes how the matrix elements Hab.ca, which are obtained from an ab initio spin valence calculation, are to be corrected in order to eliminate known atomic errors. [Pg.105]

A combined analytical and numerical method is employed to optimize process conditions for composites fiber coating by chemical vapor infiltration (CVI). For a first-order deposition reaction, the optimum pressure yielding the maximum deposition rate at a preform center is obtained in closed form and is found to depend only on the activation energy of the deposition reaction, the characteristic pore size, and properties of the reactant and product gases. It does not depend on the preform specific surface area, effective diffusivity or preform thickness, nor on the gas-phase yield of the deposition reaction. Further, this optimum pressure is unaltered by the additional constraint of prescribed deposition uniformity. Optimum temperatures are obtained using an analytical expression for the optimum value along with numerical... [Pg.183]

To determine the free-energy profile (rather then the potential energy profile as above), one performs a (typically short) constant temperature (canonical ensemble) FPMD simulation of the system (while constraining the reaction coordinate to the prescribed value) and records the mean force of constraint along the chosen reaction coordinate. This process is then repeated for a number of points along the reaction coordinate connecting the reactant and... [Pg.89]

The first question we pose is of wider generality than is needed to consider the question of electron occupancies. In particular, we ask for the relevant probability distribution for those problems in which not only is the average value of the energy prescribed, but so too is the average number of particles, N). In this case, using the maximum entropy ideas introduced above, the entropy and its associated constraints may be written as... [Pg.133]

Its solution must be finite and continuous for all values of r from zero to infinity. Here we are chiefly interested in the magnitude of the proper values E for which this equation has a solution satisfying the prescribed conditions. In particular, we shall only discuss the case where < 0. This corresponds to the elliptical orbits in Bohr s theory energy must be supplied in order to remove the electron to the boundary of the atom or, better expressed, to an infinite distance from the nucleus. The case where E > would correspond to Bohr s hjrperbolic orbits. Por the sake of simplicity we shall introduce rational units. We... [Pg.300]


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See also in sourсe #XX -- [ Pg.47 , Pg.48 ]




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