Resistance in-plane

Product Name Thickness (mm) Weight (g/m ) Bulk Density (g/cm ) Porosity (%) Tensile Strength (MPa) Stiffness (Taber) Through-Plane Air Permeability (sec/100 cc) In-Plane Air Permeability (sec/100 cc) Compressibility (%) Through- Plane Resistivity (mohm cm ) In-Plane Resistivity (mohm cm) Comments ... 

Product Thickness Weight Bulk Density Porosity Tensile Strength Stiffness Through-Plane Air Permeability In-Plane Air Permeability Compressibility Through- plane Resistivity In-Plane Resistivity... 

The most typical way to measure the in-plane electrical conductivity of a diffusion layer is through the use of the four-point probe method. A small current is applied across the sample material a separate set of voltage measuring probes that are in touch with the material are used to measure the resulting voltage drop in order to calculate the resistance. With these values, the in-plane resistivity, p, can be calculated with the following equation [9,233] ... 

Figure V 3 l. Temperature dependence of the in-plane resistivity for YBCO single crystal [4]...

This is the most desirable situation for a fuel cell, because the ohmic resistance is minimized. However, due to the disposition of the current collectors, this situation is not achievable, and a deviation along the plane of the cell is unavoidable. For this reason, the resistance generated if current flows in a straight line is usually named cross-plane resistance while the term in-plane resistance refers to the contribution due to the directional deviation. Even for the planar configuration, where expression (A3.1) is usually employed, small in-plane resistance is present (Figure A3.2). 

However, in planar SOFC, the resulting in-plane resistance has a modest contribution to the overall voltage reduction, compared to the cross-plane resistance, thus Equation (A3.1) is usually employed. 

Solution 1 is the easiest to realize, but a high in-plane resistance is expected, due to the fact that the current, in order to flow from one tube end to the other, flows along the cell. Better performance can be expected from solutions 2 and 3. 

When the current is collected through an internal and an external mesh (case 3), the current path is fairly straight, as visible from Figure 4.25. In this case, the tubular configuration operates in a condition that is very close to that of the planar configuration. The in-plane resistance is minimized, but, the manufacturability is more complex. 

FIGURE 16 Difference between the in-plane resistivity in magnetic fields and its zero-field value for LuNi2B2C at three different temperatures as a function of H2. H is parallel to the electrical current. The dashed lines represent fits according to Ap H2 (after Fisher et al., 1997). 

FIGURE 6.19 Room temperature in-plane resistivity of F GIC C Fy for different fluorine concentrations. O0 is the in-plane conductivity of host graphite pristine graphite (HOPG) and graphite fiber (VGCF). Note that y is defined as y = (1 + x) 1 for C F. (From Vaknin, D., et al., Synth. Metals, 16, 349, 1986. With permission.)... 

Fio. 11. Ratio of in-plane resistivity p, to perpendicular resistivity / as a function of a-Si H layer thickness , dark O, 1-sun illumination. 

The anisotropy in the electrical resistivity can be explained by similar arguments. In the simplest model the in-plane resistivity of the layered material is the reciprocal of the average conductivity or... 

When materials have very high conductivities, one needs to use four-electrode measurements to avoid limitations from the in-plane resistance of the electrode... 

In-plane resistance of the bipolar plate A (per unit length to currents per unit width) leads to changes in the cell voltage ... 

Fig. 23 In-plane resistance and maximum load of DGEBA carbon fibre nanocomposite as determined from mode I fracture toughness tests [135]...

Several interpretations were given of the observed linear temperature dependence of the in-plane resistivity and Hall carrier number. Although a strong temperature dependence is possible in a two-band model provided that the scattering rates are different in these two bands, a linear F-dependence requires precise cancellation between electron and... 

In the optical conductivity, the pseudogap state reveals itself in two distinct ways (i) the in-plane scattering rate at m < 700 cm is reduced which inevitably leads to reduction of the in-plane resistivity (see discussion in sect. 4.3) (ii) the interplane conductivity is reduced at 0 < 250 cm which accounts for semiconducting behavior of the c-axis resistivity (see discussion in sect 4.5). Despite the difference in the energy scales seen in the in-plane and interplane transport, these two effect are clearly coimected (Takenaka and Uchida 1994, Basov et al. 1996). 

Despite the ionic resistance of the electrolyte plays an important role in the cell ohmic resistance, it is the contribution of the anode and cathode resistance which determines the high ohmic resistance of the cell this is due to the long path of the electrons in the electrodes [29] (high in-plane resistance). The equivalent electrical circuit has been assumed by the current literature [30,31] and the ohmic overpotential has been evaluated according to the equations (42) and (43) ... 

---