Circuit approach

What sets this circuit approach apart is its institutionally relevant analysis of the relationship between banks, firms and workers. A model of the circuit of money is developed in which prime importance is placed upon the role of banks in financing industrial activities. Central to this approach is an application of the Kalecki principle, that capitalists earn what they spend the question being how an injection of money can circulate around the economy and return back to the capitalists. Moreover, how is this circuit of money intertwined with the activities of industrial sectors And how much money is required for the circuit to be complete Marx s reproduction schema provides a natural starting point for addressing these questions. 

In comparison to Marx, therefore, the circuit approach significantly reduces the amount of money that has to be advanced in order for the production process to be initiated. 

The parallel assumption of the circuit approach is that the multiplier is also equal to 1, meaning that there are no income-expenditure spill-over effects between sectors, with the amount advanced having no multiplied impact upon income. The multiplier relationship in (4.23) can be presented as a general model in which the multiplier/velocity is a parameter that can vary in value. From this perspective, the Graziani and single swap models represent a particularly narrow case in which the value of this parameter is restricted to 1. 

Although it is traditional in Marxian frameworks for capitalists to initiate the circulation of money with an advance of constant and variable capital, our previous discussion, in Chapter 4, showed that there are a number of ways in which the circulation of money can be modelled. In the single swap approach all of income is advanced in the Franco-Italian circuit approach only the wage bill is advanced in Nell s mutual exchange approach only wages in the capital goods sector are advanced. Our contribution has been to suggest, under the Kalecki principle (first introduced in Chapter 3), that capitalists advance an amount of money sufficient to realize their profits. This model is predicated on the definition of investment as accumulation of constant and variable capital. 

Similarly, for Nell (1998 206), the circuit approach in its contemporary form appears to owe its origin to Marx and for Graziani (1989 2), elements from the Marxian doctrine are surely present in the debates on the monetary circuit . 

I am grateful to Victoria Chick for suggesting to me this interpretation of the production period, and its contrast with the circuit approach. Thanks are also due to Giuseppe Fontana, and two excellent anonymous referees for Research in Political Economy, for pressing me on this and other points. 

The equivalent electrical circuit approach has already been introduced in connection with analysis of mass sensors (Chapter 4). Its application is older and somewhat... 

Equation (10) shows that we can always accomplish our objective if we can measure the full canonical distribution of an appropriate order parameter. By full we mean that the contributions of both phases must be established and calibrated on the same scale. Of course it is the last bit that is the problem. (It is always straightforward to determine the two separately normalized distributions associated with the two phases, by conventional sampling in each phase in turn.) The reason that it is a problem is that the full canonical distribution of the (an) order parameter is typically vanishingly small at values intermediate between those characteristic of the two individual phases. The vanishingly small values provide a real, even quantitative, measure of the ergodic barrier between the phases. If the full -order parameter distribution is to be determined by a direct approach (as distinct from the circuitous approach of Section IV.B, or the off the map approach to be discussed in Section IV.D), these low-probability macrostates must be visited. 

A successful equivalent circuit approach to Wagner s theory was worked out by Hoar and Price. They developed a simple voltage divider circuit which gives quantitative formulas for emf and scaling rate that are very similar to those derived more rigorously by Wagner. A linear lumped version of their proposed circuit is shown in Fig. 3. The subscripts 1, 2 and 3 refer to M cations, X anions and electrons respectively. 

In part I above, c. Wagner s theory of mixed conduction was reviewed in terms of an equivalent circuit approach. The implications of mixed conduction theory for parabolic scaling of metals in high temperature atmospheres were also detailed. It was pointed out, however, that current interest in mixed conduction theory is no longer motivated by corrosion considerations because far too few systems of practical interest conform to the conditions required for pareibolic oxidation. 

Returning to the main thread here, we note that Equations 33 and 34 apply to each mobile species individually however, in all cases of practical interest simultaneous migration of more than one species must be considered. This is especially true in the case of multicomponent electrolytes in which many kinds of ions may be mobile. But if several species are in motion they merely make simultaneous contributions to the current exchanged with the external circuit. The relative contribution of each will depend on the ease of transport in the elctrolyte, i.e., on Gj and on the chemical and electrical potential gradients which act on it. But these matters are better discussed in terms of the extended equivalent circuit approach which will now be developed. 

Several circuit approaches to perform impedance measurements have been proposed elsewhere [2], [3], [7], considering the need of exciting at a given frequency and measuring the response obtained. In experimental biology, it is worthwhile to develop automatic measurement techniques allowing researchers to monitor the evolution of their experiments on-line, yet requiring a simple set-up. 

In the following. Section 2 presents the electrical model employed for the cell-electrode system characterization, and its related parameters. Section 3 introduces the OBT circuit approach and the main circuit blocks employed for testing cell culture samples. Sensitivity curves are obtained for the proposed impedance-sensing method. Simulations and experimental results illustrating the agreement of the proposed technique are described in Section 4, and finally, Section 5 summarizes the work. 

Some details of the Randles circuit require further study. First, the double layer capacitance is in many cases more properly modeled with a constant phase element. This gives information on the mesoscopic structure of the oxide-electrolyte interface. Also, in some cases, the diffusion impedance contains a power-law behavior. The reason for this is controversial is it due to the back contact or rather an indicator of an unknown kinetic process in WO3 It should also be mentioned that the adsorption process proposed by Fianceschetti and Macdonald [1982] has not been studied in detail, and the systematic equivalent circuit approach of Janmik [2003] has only been rarely used. 

It is possible to interpret the optoelectrical impedance in terms of an electrical equivalent circuit. When doing so, the system resembles a resistor R = AQ at low frequencies and a capacitor C = tIAQ at high frequencies. At intermediate frequencies the system shows a more complex behavior. One should be careful to have a mental picture of a resistor and a capacitor when using equivalent circuit approach for interpreting IMPS data. Maybe it is better to look upon it in a more abstract mathematical way. 

Of these different modeling methods, the equivalent electrical circuit approach is the most widely used to serve the need for precision of the model without too high a degree of complexity of its implementation. 

The major shortcoming of an equivalent circuit approach is that an impedance paAem obtained experimentally can be presented by more than one equivalent... 

Wise, K. D. and Starr, A., 1969, An integrated circuit approach to extracellular micro-electrodes, Proc. 8th Int. Conf. Med. Biol. Eng. Sec. 14-5. 

The equivalent electrical circuit approach adopted maps the processes occurring in the corrosion systems and enables the determination of parameters relevant to these processes. The parameter values of individual elements of equivalent electrical circuit representing investigated corrosion systems are summarized in Table 2. 

FIGURE 1 A series of 100-element crossbar circuits, the prominent circuits of molecular electronics. The molecule of interest is typically sandwiched between the intersection of two crossed wires. This very simple circuit can be used even in the presence of manufacturing defects and can be fabricated at dimensions that far exceed the best lithographic methods. The device densities in these circuits approach lO /cm for the smallest crossbars. 

The approach developed by Danishefsky and co-workers for the construction of sugar derivatives (see Vol.l6,p.126), which employs the initial synthesis of a dihydropyrone derivative by a Lewis acid-catalyzed hetero-Diels-Alder reaction, has been extended to the synthesis of the glycoside derivative (36), x>f DL-llncosamine (Scheme 10). Introduction of the amino-function at C-6 required a circuitous approach Involving 6,7-bromohydrin, 6,7-epoxide, and N-substituted 6,7-aziridine intermediates. ... 

In another work, Du et al. (2007a) measured the impedance spectra of a half-cell cathode, with and without 0.5M methanol solution on the anode side of the membrane. The resulting spectra show an increase in the charge transfer resistance due to crossover, and a somewhat larger inductive low-frequency loop. Using the equivalent circuit approach, the increase in the loop radius was attributed to the poisoning of the Pt surface by MOR intermediates. 

Wise KD, AngeU JB, Starr A (1970) An integrated-circuit approach to extracellular microelectrodes. IEEE Transactions on Biomedical Engineering BME-17 238-247. 

At this point it should be cautioned that the equivalent circuit approach can yield detailed information of the physicochemical processes of ohmic, mass transfer, and kinetic resistances for a given system, but it is subject to the assumptions of the equivalent circuit used. That is, the use of equivalent circuit analysis offers infinite possibilities and combinations of electrical circuits which all can be rearranged in different ways. The EIS... 

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