Conductor unipolar

Because of the high values of conductivity which in individual cases are found at room temperature, such compounds are often called superionic conductors or ionic superconductors but these designations are unfounded, and a more correct designation is solid ionic conductors. Strictly unipolar conduction is typical for all solid ionic conductors in the silver double salts, conduction is due to silver ion migration, whereas in the sodium polyaluminates, conduction is due to sodium ion migration. 

With unipolar (or net unipolar) clouds, however, the rate of deposition will be essentially the same as the rate of expansion of the edge of the cloud. In fact, with very large conductors or grounded objects, because of image forces (which will reflect those of the entire cloud rather than just those of an individual particle), the rate of deposition would be expected to be just twice as fast as the rate of expansion of the edge of the cloud. Thus, since the deposition rate will be the product of velocity and concentration, one may use Eqs. (9) and (11) to predict the following deposition rate from a net unipolar charged cloud ... 

The majority of unipolar ionic conductors identified to date are polymorphic compounds with several phase transitions, where the phases have different ionic conductivities owing to modifications in the substructure of the mobile ions [28], One of the first studied cationic conductors was a-Agl [21]. Silver iodide exhibits different polymorphic structures. Agl has a low-temperature phase, that is, [3-Agl, which crystallizes in the hexagonal wurtzite structure type, and a high-temperature cubic phase, a-Agl, which shows a cubic CsCl structure type [20,22] (see Section 2.4.5). 

Fig 1.10 Elema-Schonander unipolar lead with conductor made of stainless steel bands, (from [1], Chap. 9, p. 1) (courtesy of Medtronic)... 

Unipolar leads obviously have only one conductor coil, whereas bipolar leads require two -one for the proximal and the other for the tip electrode. Bipolar leads may have a coaxial, a co-radi-al or parallel wound, and a parallel or multiluminal design. Coaxial bipolar leads, standard in treating... 

Fig. 5.2 Low-profile knot performed with a nonabsorbable suture over the insulation of each conductor present in the lead (a) unipolar pacing lead (b) implantable cardioverter-defibrillator (ICD) integrated lead (c)bipolar pacing lead. The arrows show at which level the low-profile knot should be performed...

Strictly unipolar conduction is typical for all solid ionic conductors in the silver double salts, conduction is because of silver ion migration, while in the sodium polyaluminates, conduction is because of sodium ion migration. 

Ann. Phys.y 1806, xxii, 14-50 an alcohol flame conducts only from the positive wire, soap conducts only from the negative wire this was the first current rectifier. Ohm, J. Chem. Phys.y 1830, lix, 385 1830, lx, 32, explained it for solids by the deposition of a non-conducting layer (e.g. fatty acid) on one wire. Erman divided bodies into (i) non-conductors, (2) complete conductors, (3) incomplete conductors, (4) unipolar positive conductors, (5) unipolar negative conductors. 

Size. The original bipolar lead designs had two parallel conductors individually encased in a stiff, dual-lumen insulated tube and a very bulky bifurcated connector. They were difficult to implant compared to unipolar models. In comparison modem bipolar pacing leads are as thin as their unipolar counterparts and thus size is no longer an issue. 

The pacing lead conductor is composed of wire that conducts the electrical current from the pulse generator to the stimulating electrode and the sensed cardiac signals (intrinsic or evoked) from the electrode(s) to the sensing amplifier of the pulse generator. Unipolar leads require one conductor, whilst bipolar... 

Fig. 1.22 MultifilaT helically coil conductors. Above Unipolar. In this example, there are five single uninsulated strands of tightly coiled wire around a central core though which the stylet passes. The coils are covered with insulating tubing. Middle Bipolar coaxial design, which is currently the most common conductor arrangement There are two multifilar helical coils surrounded by two insulating tubes. The inner is the cathode and the outer surrounding conductor is die anode. This round design is of intermediate size and thicker than a standard unipolar lead. (Permission for use Medtronic.)...

Fig. 5 Examples of various types of lead conductors and their insulation A. a unipolar single-filar conductor coil, B. parallel single-filar conductor cods, C. coaxial multifilar conductor cods, and D. a multifilament microcable...

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