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Each independent and dependent operator has two aspects 1) Operation represents a component requiring actuation. For example, a motor-operated valve, is represented as a Type 6 operator since the valve needs both an input (flow) and an actuation (electric power) to pass the flow... [Pg.121]

In practical product design, a full LCA is seldom performed. The unit operations represent whole systems, which are used as building blocks. Typical examples include elementary flows determined for the manufacture of 1 m-1-mm sheet metal of galvanized steel, incineration of 1 kg of polyethylene, or production and distribution of 1 MJ electricity. ... [Pg.1362]

There are two modes of filter operation representing extreme eases of filtration viz. (1) eonstant rate and (2) eonstant pressure. [Pg.92]

The operator hi is a one-electron operator, representing the kinetic energy of an electron and the nuclear attraction. The operators J and K are called the Coulomb and exchange operators. They can be defined through their expectation values as follows. [Pg.121]

The operator representing the angular momentum of a mass point circulating about the e-axis was given in the specific form... [Pg.391]

This result holds equally well, of course, when R happens to be the operator representing the entropy of an ensemble. Both Tr Wx In Wx and Tr WN In WN are invariant under unitary transformations, and so have no time dependence arising from the Schrodinger equation. This implies a paradox with the second law of thermodynamics in that apparently no increase in entropy can occur in an equilibrium isolated system. This paradox has been resolved by observing that no real laboratory system can in fact be conceived in which the hamiltonian is truly independent of time the uncertainty principle allows virtual fluctuations of the hamiltonian with time at all boundaries that are used to define the configuration and isolate the system, and it is easy to prove that such fluctuations necessarily increase the entropy.30... [Pg.482]

Gas-liquid-particle operations represent efficient tools or building blocks for the chemical engineer, and it seems likely that their application will spread. Progress in this direction will depend, in part, on the continuation and extension of investigations of the types reviewed in this paper. It may be said that the research carried out to date has only scratched the surface of this subject. [Pg.131]

For a single electron, the velocity operator in eq.(7) corresponds to the current operator j(Ro,B) = —ev, and hence to the following operator representing the magnetic field induced at a field point R... [Pg.196]

In a comprehensive study of trichloroethylene emission sources from industry conducted for EPA, the major source was degreasing operations, which eventually release most of the trichloroethylene used in this application to the atmosphere (EPA 1985e). Degreasing operations represented the largest source category of trichloroethylene emissions in 1983, accounting for about 91% of total trichloroethylene emissions. Other emission sources include relatively minor releases from trichloroethylene manufacture, manufacture of other chemicals (similar chlorinated hydrocarbons and polyvinyl chloride), and solvent evaporation losses from adhesives, paints, coatings, and miscellaneous uses. [Pg.204]

Much of the great interest that the Reduced Density Matrices (RDM) theory has arisen since the pioneer works of Dirac [1], Husimi [2] and Lowdin [3], is due to the simplification they introduce by averaging out a set of the variables of the many body system under study. For all practical purposes, the averaging with respect to A-1 or N-2 electron variables which is carried out in the -RDM or 2-RDM respectively, does not imply any loss of the necessary information. The reason for this is that the operators representing the AT-electron observables are sums of operators which depend only on one or two electron variables. [Pg.55]

The effluent limitations of all aluminum forming operations representing (a) the degree of effluent reduction attainable by the application of the BPT currently available and (b) the degree of effluent reduction attainable by the application of the BAT economically achievable, can be found from the... [Pg.221]

Table 7.8 indicates that the major regulated parameters for pretreatment of coil coating industrial wastewater are chromium, cyanide, zinc, total toxic organics (TTO), oil and grease, manganese, fluoride, phosphorus, and copper. The effluent limitations of all coil coating operations represent the following ... [Pg.295]

It is assumed that a given Fourier-transform operation, represented by... [Pg.142]

In this expression, cfaa is an operator representing the creation of an electron with spin ct(ct =t or J,) and orbital state a at site i, cirm is the corresponding annihilation operator, and the operator htrln = cltncirm appearing in... [Pg.200]

You can describe the acidity of an aqueous solution quantitatively by stating the concentration of the hydronium ions that are present. [HsO" ] is often, however, a very small number. The pH scale was devised by a Danish biochemist named Spren Sorensen as a convenient way to represent acidity (and, by extension, basicity). The scale is logarithmic, based on 10. Think of the letter p as a mathematical operation representing -log. The pH of a solution is the exponential power of hydrogen (or hydroni-um) ions, in moles per litre. It can therefore be expressed as follows ... [Pg.390]

If in the non-BO calculation one chooses a basis set of eigenfunctions of the operator representing the square of the total angular momentum and the... [Pg.382]

For the heteronuclear (HEN) A2B-type species, the symmetry operator was = 1(82) Ye 82)- In this case the nuclear operator was a singlet for H parrs and symmetric for D pairs. Finally for the HEN HDT-type isotopomer we had = e(82). Again in all cases the electron operators represented a singlet. For discussion of the construction of the operators, see, for example, the excellent work of Pauncz [73]. [Pg.467]

Such an operation represents, in the synthetic sense, the classical Williamson reaction (or its r/j/o-equivalent in the case of sulphur). However, with amines, in order to avoid polyalkylations, a FGA must be carried out beforehand, introducing a carbonyl group (=0) at the p.ro-position, and proceeding then to the ipso-disconnection to afford the amine and an acyl derivative -as an acid chloride, for instance-, since in the synthetic direction monoacylations can be easily controlled owing to the deactivation of the resulting amide, which prevents further acylations. In practice, the amide can then be reduced by UAIH4. As an alternative solution, a... [Pg.103]

This operation represents on cycle of the adsorbent inventory. [Pg.257]

The older modular simulation mode, on the other hand, is more common in commerical applications. Here process equations are organized within their particular unit operation. Solution methods that apply to a particular unit operation solve the unit model and pass the resulting stream information to the next unit. Thus, the unit operation represents a procedure or module in the overall flowsheet calculation. These calculations continue from unit to unit, with recycle streams in the process updated and converged with new unit information. Consequently, the flow of information in the simulation systems is often analogous to the flow of material in the actual process. Unlike equation-oriented simulators, modular simulators solve smaller sets of equations, and the solution procedure can be tailored for the particular unit operation. However, because the equations are embedded within procedures, it becomes difficult to provide problem specifications where the information flow does not parallel that of the flowsheet. The earliest modular simulators (the sequential modular type) accommodated these specifications, as well as complex recycle loops, through inefficient iterative procedures. The more recent simultaneous modular simulators now have efficient convergence capabilities for handling multiple recycles and nonconventional problem specifications in a coordinated manner. [Pg.208]

The perturbation method (abr. p.m.) is one of the most important methods of approximation in quantum mechanics as well as in some fields of classical mechanics. It is usually presented in the following form. Let H0 be the operator representing some physical quantity of the unperturbed system and let i c0 be the perturbation, where k is a parameter assumed to be small. Then p.m. consists in solving problems concerning the perturbed operator H% = H0 + by expanding the results into power series of k, assuming that they are already solved for the unperturbed operator H0. [Pg.2]

** Key Indicators Represent Operation Opportunities **

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