Resistance calculation

Before a fan selection can be completed either by the owner s engineer or the manufacturer, a system resistance calculation must be made at several selected fan volume flow rates. This will be discussed in the section, Summary of Fan System Calculations, Figure 12-128... 

The reduction in the tensile load capacity of the drill pipe is 311,400 -260,500 = 50,900 lb. That is about 17% of the tensile drill pipe resistance calculated at the minimum yield strength in uniaxial state of stress. For practical purposes, depending upon drilling conditions, a reasonable value of safety factor should be applied. 

Figure 4-276. Comparison of the compensated dual-resistivity log resistivities run while drilling to the invaded and noninvaded resistivities calculated with wireline phasor induction data. The spurt loss is the ratio R /R (Courtesy Anadrill [tt3].)...

Table 10.3. Composition of candidate alloys and results of calculations on toughness, weldability and corrosion resistance. Calculation was conducted assuming an annealing temperature of 1050°C, 0.8%Mn, 0.7%Si and 0.024%C (wt%). PRE value in the heading of the table indicates value for SAF2205 (from Lee 1995)...

For a particle with an energy E, the effective gap seen is A — E. At low temperatures, we can take into account the excess resistance due to charge imbalance by introducing an effective voltage dependent charge imbalance time tq caT/(A — eV), and adding a resistance Rq = PaAq to the resistance calculated in the spin-polarized BTK model described above. 

A geometrical factor, k, can then simply be calculated from a ratio of these two voltages and the sheet resistance calculated from... 

Fig. 9.4. Typical loss of current density as a function of ZnO sheet resistance calculated for three values of the absorber bandgap (assuming air mass 1.5 illumination, redrawn with permission from [12])...

Fig. 9.6. Calculated optimum interconnect distance and resulting module efficiency as a function of ZnO sheet resistance. Calculations are based on the properties of a small area CIGSe-based cell with 14.4% efficiency. Reprinted with permission from [17]...

The plethysmograph is sealed and the mouse ventilated for 5 min with readings monitored by computer. The accepted index of airway function is airway resistance, calculated by a change in pressure/a change in flow (see Note 4). 

From the R and C values of the time constants a-c in the model, it was possible to estimate the thickness and resistivity of layers comprising the compact part of the surface films. The temperature dependence of these three time constants (e.g., linear Arrhenius plots for the different resistivities calculated that reflect different activation energy for Li+ ion migration in each layer), as well as their dependence on the solution composition and the experimental conditions, revealed that the model has a solid physicochemical ground [48,49,186],... 

Based on the relative values for the two permeability coefficients, the resistance to the diffusion of HC03 across the plasma membrane is about 5 x 104 times higher than that for C02, for example, 5 x 106 s m-1. Because of the extremely high resistance for HCO3-, we conclude that bicarbonate does not diffuse across the plasma membrane at a rate necessary to sustain photosynthesis. The plasma membrane resistance calculated for CO2 (100 s m-1) is relatively small (Table 8-4), which suggests that diffusion of CO2 is adequate for moving this substrate of photosynthesis across the plasma membrane. 

F.q. (16-23). Subsequently, it became clear that a theoretical form for S (q)S(q) given by Percus and Yevick (1958) and Pcrcus (1962) was more convenient, and probably as accurate as the experiment for the resistivity calculation. This approach was used by Ashcroft and Lckner (1966) for an extensive study of the resistivity of all the simple liquid metals. The form due to Pcrcus and Yevick depends only upon two parameters, a hard-sphere diameter and a packing fraction these lead to a simple form in terms of elementary functions Ashcroft and Lckner discuss the choice of parameters. This form is presumably just as appropriate for other elemental liquids. 

The through-the-thickness reinforcement acts as a crack bridging, which requires new concepts and methods to be used for the fracture resistance calculation. 

For any pair of non-adjacent vertices, the resistance distance is the effective resistance calculated according to the two classical Kirchhoff laws for series and parallel electrical circuits some examples of calculations are given in Box R-1 for ethylbenzene. 

T. Smedes, N.P. van der Mejis and A.J. van Gendered. Boundary Element methods for 3D capacitance and substrate resistance calculations in inhomogeneous media in a VLSI layout verification package. Advances in Engineering Software 20. pp 19-27. 1994. 

Sokolov, Yu.Yu. (1984) Equations of flexible vegetation inclination in connection with flood-land resistance calculation, Dynamics and thermal regime of rivers and ponds, Moscow Nauka Publ., 72-85. 

Surface resistivity. One side of the specimen is coated with a circle of silver paint surrounded by a ring of silver paint. The uncoated distance between the circle and the ring is an effective length on which surface resistivity is measured. The other surface of the specimen is fully coated with silver paint. Current and voltage are measured and surface resistivity calculated. If samples contain internal or external antistatics, the measurement is performed under a controlled atmosphere to eliminate the influence of temperature and relative humidity. Also, specimen conditioning is used to account for migration of the antistatic to the surface. The surface of specimen containing antistatics is not coated with silver paint, but electrodes are... 

Capacitances and resistances calculated for the two maxima at various bias potentials are shown in Table 1. Capacitances calculate from the high frequency maximum are of the order of 0.1 pF cm and increase with increasing cathodic potential. The time constant remains constant in the potential region studied. The value of the capacitance and the potential dependences are close to those expected for the space charge region and hence are assigned to this. 

At high enough qualities and mass fluxes, however, it would be expected that the nucleate boiling would be suppressed and the heat transfer would be by forced convection, analogous to that for the evaporation for pure fluids. Shock [282] considered heat and mass transfer in annular flow evaporation of ethanol water mixtures in a vertical tube. He obtained numerical solutions of the turbulent transport equations and carried out calculations with mass transfer resistance calculated in both phases and with mass transfer resistance omitted in one or both phases. The results for interfacial concentration as a function of distance are illustrated in Fig. 15.112. These results show that the liquid phase mass transfer resistance is likely to be small and that the main resistance is in the vapor phase. A similar conclusion was reached in recent work by Zhang et al. [283] these latter authors show that mass transfer effects would not have a large effect on forced convective evaporation, particularly if account is taken of the enhancement of the gas mass transfer coefficient as a result of interfacial waves. 

The value of 1.18 10" m.g" is close to the specific resistance calculated using the Carman-Kozeny equation ((6.4)) for hematite particles of diameter (dp) 70 nm, density (pp) of 5.2 g.cm - and packing densit) of 0.4, i.e. onty slightly less compact than that arising from random close packed spheres for which 1-e = 0.63. This value is 1.30 10" m.g. ... 

Rolling resistance calculated from the heat generation rate (Rc) 13.2 Ibf 14.0 Ibf... 

The ground-bed resistance is similar to that of the total circuit resistance calculated for the design of a sacrificial system (Section 15.6.2). In this case, multiple anodes are used and the resistance of anode to ground is calculated from Sunde equation [88]. 

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