Resistance Behavior

Crack propagation, ceramics, 5 628-630 Crack-resistance behavior... 

The resistivity behavior of La2Cu04, and several other substituted La2Cu04 derivatives, were studied (121) in the USSR. In many samples, the alkaline-earth ions were substituted for the Las+ ion. Their results indicated metallic behavior for La2Cu04 and all the measured alkaline-earth derivatives, but semiconductive behavior for the other Ln2Cu04 parent compounds and their alkaline-earth derivatives. Selected resistivity data for alkaline-earth doped La2Cu04 derivatives are presented in Figure 23. 

Figure 9 Resistive behavior for a film of Tl2Ba2Ca2CusO10 made by spraying of nitrates. (After Reference 49.)...

Dissipation or resistive behavior in a superconductor develops when the quantized vortices depin and cut across the current flow. Vortices are established in these superconductors either with an applied magnetic field or from the self field of a current. Visualization of the vortex structure in the high temperature superconductors has been studied with a Bitter decoration technique by Dolan et al. 

Positive Electron-beam Resist of Poly (a-substituted Benzyl Methacrylate). The electron-beam resist behaviors of poly(a-substituted benzyl methacrylate)s are given in Table III. When the exposed resist films were developed with a mixture of MIBK and IPA, the sensitivities of these polymers were on the order of 10-4 C/cm2. When a dilute solution of sodium methoxide in methanol was used as a developer, the sensitivity was enhanced as compared with the former case, and increased with an increase in the bulkiness of the ester group of the polymer except for poly(a,a-diphenylethyl methacrylate). 

A distinctive advantage of having digital materials at our disposal is the ability to study catalyst deposition processes in these media. Depending on the way the catalyst is applied (e.g. from a solution or from a slurry) the catalyst coating degree of uniformity (Fig. 6) is expected to lead to different flow resistance behavior of the DPF. 

The flow resistance behavior of the reconstructed medium can now be examined by performing 3D flow simulations with the Lattice Boltzmann method (Chen and Doolen, 1998), and obtaining the permeability of the material (Konstandopoulos, 2003). Figure 8(a) depicts a visualization of 3D flow tubes and flow velocity distributions at different cross sections in a reconstructed filter material. Figure 8(b) shows the comparison of computer simulated and experimental permeabilities obtained with the experimental protocol described in Konstandopoulos (2003). 

There is much evidence, however, that the resistivity behavior of a cake under filtration conditions may be different from that measured in a CP cell. The literature is reviewed by Wakeman... 

Analysis by Dissolution Curves. Most performance indicators require only an operational definition these concepts are explained by a film dissolution curve. Figure 2 shows a family of such curves, in which the individual curves correspond to resist behavior in developer solution after exposure to the indicated radiation dose level. Figure 2 is constructed for... 

In fig.l there are presented results of detailed analysis of resistive behavior for YBCO single crystal in the model where total resistivity ptot is... 

Figure 2. Phase diagram of the metal insulator transition in V2O3 as a function of doping with Cr or Ti (regarded as chemical pressure) as well as actual pressure, showing a critical point (after Me Whan, D. B. et al. Phys. Rev. Lett. 1971,27,941). The three phases are paramagnetic insulator (PI), metal, and antiferromagnetic insulator (AFI). The different kinds of resistivity behavior in Figure 3 correspond to different constant pressure (or Cr, Ti content) cuts in this phase diagram.

Ohmic resistance — For a wide variety of materials and conditions, the electrical resistance does not depend on the amount of current flowing or the amount of applied voltage. In such cases, a plot of voltage applied (measured) across the material versus the measured (applied) current through the material will be linear, the slope of the plot being the ohmic resistance, Rq. The material obeys ohm s law and such materials are described as ohmic. See ohmic resistance behavior. 

At temperatures below 300° K. deviations from linear p vs. T behavior may appear, particularly when the ratio of M to W03 is below 0.3. This has been observed on single crystals of copper-doped WOs (36), silver-doped WOs (5), and low-sodium Na WOs (20). It is postulated that a second-order transition occurs, which is related to the ferroelectric transition in W03. This transition which occurs in the neighborhood of 220° K. (it is spread over roughly 50°, probably because it occurs piecemeal as a domain-growth phenomenon), shows up in pure W03 in its resistivity behavior, its Hall coefficient, and its thermoelectric power (7). The carrier mobility drops significantly as the temperature is lowered through the transition, so it is probable that the rather steep rise in resistivity... 

Finally, one should not forget the purely one-dimensional models, such as calculation of the conductivity of the one-dimensional interacting electron gas [50]. Such a model also gives a power law for the resistivity. For an attractive long-range electron-electron interaction there is an enhancement of ah and a different power law from that expected for (say) phonon scattering. However, it is not clear whether such a model applies to the compounds in Fig. 1, which have different ground states, yet still show similar resistivity behavior. 

Many of the Bechgaard salts show at ambient pressure a metal-insulator transition, Tmi, around a few tens of K as can be seen from the resistivity behavior shown for several (TMTSF)2X salts in Fig. 2.5 [35]. This transition is... 

The metal-insulator transition induced by hydrogen causes also changes of the electric resistance of the sample. The physical relation is rather complicated as it depends on the electronic changes as well as hydride growth mechanism and morphology. Therefore, in most cases, the change in resistance behavior is used to determine the onset of hydride formation/ decomposition. Repeating the measurements at various applied pressures/temperatures reveals a van t Hoff plot, similar to DSC-measurements (2.3). 

The phase angle is a more sensitive test of the capacitive or resistive behavior of the system than is the plot of log Z(co) versus log(co). The detailed shapes of these curves depend, of course, on the numerical values chosen for the various circuit elements. Had we used a... 

There is much evidence, however, that the resistivity behavior of a cake under filtration conditions may be different from that measured in a CP cell. The literature is reviewed by Wakeman (1978). CP cell data are easily obtained and may be of value in a qualitative sense as an indication of the sensitivity of resistivity to pressure, but apparently are not of acceptable engineering accuracy for the design of filtration equipment. The deduction of resistivities fi om filtration tests is illustrated in Example 11.1. 

Resist Behavior in Excimer Laser Irradiation 3.4.5.1 Reciprocity Behavior... 

Most often, it is the anodic polarization behavior that is useful in understanding alloy systems in various environments. Anodic polarization tests can be conducted with relatively simple equipment and the scans themselves can be done in a short period of time. They are extremely useful in studying the active-passive behavior that many materials exhibit. As the name suggests, these materials can exhibit both a highly corrosion-resistant behavior or that of a material that corrodes actively, while in the same corrodent. Metals that commonly exhibit this type of behavior include iron, titanium, aluminum, chromium, and nickel. Alloys of these materials are also subject to this type of behavior. 

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