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Two-group equations

The discussion of the two group equations (10), (10 a) leads only to rather obvious results in the case of a simple, bare pile and their usefulness becomes apparent only in less simple cases. The situation is rather the opposite for the modifled Fermi equations (7), (7 a) which can be solved easily only for a simple bare pile. Even finding the adjoint operator to... [Pg.548]

The appropriate two-group equations for the flux distribution within the rod are given by (8.149). In the present application 4n and < 2 denote the fast and thermal fluxes, respectively, in the reactor core, and 3 and 4>4, those in the control rod. The boundary conditions to be satisfied by the fast flux 3 are the usual requirements of continuity and finiteness ... [Pg.733]

In making certain mathematical approximations to the Schrodinger equation, we can equate derived terms directly to experiment and replace dilTiciilL-to-calculate mathematical expressions with experimental values. In other situation s, we introduce a parameter for a mathematical expression and derive values for that parameter by fitting the results of globally calculated results to experiment. Quantum chemistry has developed two groups of researchers ... [Pg.217]

S-Goncept and Its Application. The assumptions and conditions for deriving equations 7, 11, and 15 impose limitations on the appHcation of the Z-concept and fall into two groups. The first concerns the particulate material. Particles (or drops) are assumed to be spherical in shape and uniform... [Pg.400]

Fluormated organosilanes are also formed by the addiuon of trimethylsily-iated ketene acetals to hexafluoroaceione [S ], a process that appears to be dnven by the enhanced electrophihcity of the carbonyl carbon, which results from the presence of two adjacent influoromethyl groups (equation 72)... [Pg.598]

Addition of amines to a,/J-unsaturated sulfones has been used in synthesis of key intermediates of biotin. In this reaction, benzylamine serves first as a base in the reaction with 60 to afford thiophene 1,1-dioxide (61) and also as a nucleophile to introduce two amino groups (equation 57)49. [Pg.776]

Oosawa (1971) developed a simple mathematical model, using an approximate treatment, to describe the distribution of counterions. We shall use it here as it offers a clear qualitative description of the phenomenon, uncluttered by heavy mathematics associated with the Poisson-Boltzmann equation. Oosawa assumed that there were two phases, one occupied by the polyions, and the other external to them. He also assumed that each contained a uniform distribution of counterions. This is an approximation to the situation where distribution is governed by the Poisson distribution (Atkins, 1978). If the proportion of site-bound ions is negligible, the distribution of counterions between these phases is then given by the Boltzmann distribution, which relates the population ratio of two groups of atoms or ions to the energy difference between them. Thus, for monovalent counterions... [Pg.61]

Since sulphones 204 are easily available compounds one would expect that they could be used as starting materials for the preparation of sulphoxides via the selective removal of one oxygen atom from the sulphonyl group (equation 112). Up to now, there is only one example reported of a direct reduction of a sulphone to a sulphoxide. The bicyclic dideuterio sulphone 205 after 24 h treatment with three-fold excess of diisobutyl aluminium hydride in boiling dichloromethane gave the corresponding sulphoxide 206 in 36% yield (equation 113). A two-step procedure for the selective reduction of sulphones to sulphoxides, which involves an initial reaction of sulphone 204 with aryldiazonium tetrafluoroborate 207 to form aryloxysulphoxonium salt 208 and its subsequent reduction (equation 114), was alluded to by Shimagaki and coworkers and... [Pg.280]

How did the network do this Encoded in the network s connection weights is the equation of the line that separates the two groups of points this is... [Pg.21]

The term in brackets is the value of Y calculated using equation (2.10). The actual value of Y for the point is subtracted from this, and, if the result is negative, the point lies above the line that divides the two groups and, therefore, is in group 1, while, if the value is greater than zero, the point lies below the line and is in group 0. If the value is zero, the point lies exactly on the line. [Pg.21]

While technically not "organometallics," enamines are reagents that can provide nucleophilic carbon for new bond formation. Two groups of researchers have reported on the use of such reagents for the formation of new carbon-phosphorus bonds through displacement of chloride from phosphorus.72 73 For example, displacement of bromide from phosphorus tribromide has been used for the introduction of a new thiophosphoryl functionality adjacent to an original carbonyl group (Equation 4.28).72 This approach provides a facile access to (3-ketophosphonates. [Pg.124]

This process is likely to proceed via a palladacycle intermediate followed by a Pd(ll) to Pd(iv) oxidation. Reductive elimination occurs with C-O bond formation and regeneration of the Pd(ll) catalyst. Evidence for a palladacycle intermediate is supported by the high regioselectivity (8-Me group oxidized) observed for the oxidative functionalization of 5,8-dimethylquinoline, which, in the absence of a possibility of coordination, would otherwise contain two identical methyl groups (Equation (57)). [Pg.120]

After the classification of the unmeasured variables is completed, we need to classify the measured ones. First, the set of equations is divided into two groups ... [Pg.55]

Now, for the sequential treatment of constraint and measurements equations, consider the system partitioned into two groups as follows ... [Pg.121]


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See also in sourсe #XX -- [ Pg.99 ]




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