Frequencies defined

Sample Frequency. Defines the sampling frequency, in MHz, to be used in the digitisation of the A-scan signal. 

Perform layout inspection and functional testing at a frequency defined by the customer. 

Before deriving the rate equations, we first need to think about the dimensions of the rates. As heterogeneous catalysis involves reactants and products in the three-dimensional space of gases or liquids, but with intermediates on a two-dimensional surface we cannot simply use concentrations as in the case of uncatalyzed reactions. Our choice throughout this book will be to express the macroscopic rate of a catalytic reaction in moles per unit of time. In addition, we will use the microscopic concept of turnover frequency, defined as the number of molecules converted per active site and per unit of time. The macroscopic rate can be seen as a characteristic activity per weight or per volume unit of catalyst in all its complexity with regard to shape, composition, etc., whereas the turnover frequency is a measure of the intrinsic activity of a catalytic site. 

The frequency defines the diffusion depth in the working gas and the regenerator material. The diffusion depth, d, is given by ... 

Figure 1.25 exemplifies the strucmres of certain efficient precatalysts for asymmetric transfer hydrogenation of ketones. Precatalysts C1-C3 use the NH effect described above. A turnover frequency, defined as moles of product per mol of catalyst per hour, of 30,000 h is achieved by using of C2 and an alkaline base in 2-propanol. A Rh complex C3 is an isolobal to the corresponding arene-Ru complex (see Figure 1.23). The Ru complexes C4 " and C5 without NH group in ligand catalyze the reaction by different mechanisms. A higher than 90% optical yield is achieved by using C5 in reduction of certain aliphatic ketones.

In order to evaluate the vibrational frequencies defined within the model described in Section 2.1, the second derivative of the electronic energy with respect to the nuclear coordinates (usually the normal coordinates) must be evaluated. There are three different methods of evaluation of the second derivative namely, it is possible to perform numerical second differentiation, numerical first differentiation of analytical derivatives, or direct analytical second differentiation. These derivatives provide the matrix of force constants which when diagonalized gives frequencies of the IR transitions as well as their normal modes (the degree and direction of the motion of each atom for a particular vibration). ... 

For the sake of consistency and convenience, rates to products quoted throughout this review are given in terms of turnover frequency, defined here as the number of moles of product formed per gram-atom of metal per hour. This provides units of reciprocal hours, rather than the more commonly accepted reciprocal seconds. For the reactions described here, however, use of the former units affords numbers of a magnitude convenient for ready comprehension and comparison. 

By using the field with the modulated amplitude and frequency defined in Eq. 

A wave packet can be formed by combining two harmonic waves of equal amplitude a, but slightly different frequencies, defining a total disturbance... 

The transducer operates most efficiently when the SAW wavelength, A, matches the transducer periodicity, d. This occurs when the transducer is excited at the synchronous frequency, defined by/<, = vjd, where v is the SAW propagation velocity. 

The second model (HI) is less involved. It has received some use (Y2) because of its simplicity. A representative drop of the dispersed phase is assumed to interact with an ensemble of other drops at a certain frequency defined by an interaction coefficient. The equation governing the temporal variation of concentration in the drop is given by... 

The reduced presentation of the data given in Figure 18.6 shows that the impedance response is dominated by a single relaxation process with an activation energy near 0.83 eV. The impedance data collected at different temperatures were normalized by the maximum mean value of the real part of the impedance and plotted against a normalized frequency defined by... 

Malmierca, M. S., Rees, A., Le Beau, F. E., and Bjaalie, J. G. (1995). Laminar organization of frequency-defined local axons within and between the inferior colliculi of the guinea pig. J. Comp. Neuro. 357(1), 124-44. 

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