Passive elements

The basie passive elements of eleetrieal systems are resistanee, induetanee and eapa-eitanee as shown in Figure 2.10. 

Localised corrosion can occur if the passivating element of an alloy is locally depleted from the matrix. This may occur in the sensitized regions of stainless steels for example, as outlined above. Other alloy components too. 

The passive films formed by the addition of sufficient amounts of valve metals to amorphous nickel-valve-metal alloys are exclusively composed of valve-metal oxyhydroxides or oxides such as TaOjCOH) , Nb02(OH) or TajO,. Consequently, amorphous alloys containing strongly passivating elements, such as chromium, niobium and tantalum, have a very high ability... 

As can be seen in Fig. 3.67, the corrosion resistance of amorphous alloys changes with the addition of metalloids, and the beneficial effect of a metaU loid in enhancing corrosion resistance based on passivation decreases in the order phosphorus, carbon, silicon, boron (Fig. 3.72). This is attributed partly to the difference in the speed of accumulation of passivating elements due to active dissolution prior to passivation... 

IZI=J(Z )2+(Z ), and phase angle shift,, vs. f). The electrochemical system is then simulated with an electrical circuit that gives the same impedance response. Ideally this electrical circuit is composed of linear passive elements, e.g. resistors and capacitors, each of which represents individual physicochemical steps in the electrochemical reaction. ... 

By the beginning of the eighteenth century, water and earth had become the two passive elements in a way they were the old Aristotelian matter onto which various properties were impressed by the active elements, SPIRIT, FIRE, and SALT. Surely earth is the more passive, indeed, its recognition depends upon its extreme passivity. It is the otherwise undistinguished material that remains after a fire analysis, it s what doesn t distill off, called the caput mortuum. Later, some time in the late sixteenth or early seventeenth century, it was recognized that the solid residue of fire analysis had to be divided because it often contained salt, which could be... 

As seen from (3.29), zooplankton are considered passive elements of the ecosystem subject to physical processes of transference in space as a result of water movement. However, zooplankton are known to migrate mainly in the vertical direction. In the given model we can use a simple mechanism to simulate the process of vertical migration of zooplankton. For this purpose, we divide the whole water thickness into two layers 0 < z < z0 and z0 < z < H. Let us suppose that zooplank-... 

Planar resonators and microstrip and coplanar transmission lines represent the passive elements in almost any integrated circuit technology at first, on chip integration in socalled mmics (monolithic microwave integrated circuits) with SiGe or m/v semiconducting active... 

Circuit elements can be classified into two categories, passive elements and active elements. The former consumes energy and the latter generates energy. Examples of passive elements are resistors (measured in ohms), capacitors (measured in farads), and inductors (measured in henries). The two typical active elements are the current source (measured in amperes), such as generators, and the voltage source (measured in volts), such as batteries. 

It is well known that the behavior of electrical transmission lines can be represented in terms of distributed passive elements. As we mentioned at the beginning of this chapter, there exists an analogy between the electrical and mechanical behavior of the systems. Returning to the Maxwell model, one has... 

We can generalize the analogy by considering the viscoelastic materials as a continuum where the theory of transmission lines can be applied. In this way, a continuous distribution of passive elements such as springs and dash-pots can be used to model the viscoelastic behavior of materials. Thus the relevant equations for a mechanical transmission line can be written following the same patterns as those in electrical transmission lines. By representing the impedance and admittance per unit of length by g and j respectively, one has... 

Passive circuit elements are components that do not generate current or potential. A passive electrical circuit is composed only of passive elements. Only an element with two contacts is considered here, which is analyzed by considering the current flowing through and the potential difference between the contacts, shown as open circles in Figure 4.1. 

Electrical circuits can be constructed from the passive elements shown in Figure 4.1. The fundamental relationship between current and potential for the resistor... 

Figure 4.1 Passive elements that serve as components of an electrical circuit.

The response in current of the passive elements to a pure sinusoidal potential modulation... 

For two passive elements in series, the same current must flow through the two elements, and the overall potential difference is the sum of the potential difference for each element. Thus, according to the definition of impedance given as equation (4.19), the impedjmce for the series arrangement shown in Figure 4.2(a) is given by... 

For two passive elements in parallel, the overall current is the sum of the current flowing in each element, and the potential difference is the same for each dipole. 

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