Potential conversion factors

Corrosion Rate by CBD Somewhat similarly to the Tafel extrapolation method, the corrosion rate is found by intersecting the extrapolation of the linear poi tion of the second cathodic curve with the equihbrium stable corrosion potential. The intersection corrosion current is converted to a corrosion rate (mils penetration per year [mpy], 0.001 in/y) by use of a conversion factor (based upon Faraday s law, the electrochemical equivalent of the metal, its valence and gram atomic weight). For 13 alloys, this conversion factor ranges from 0.42 for nickel to 0.67 for Hastelloy B or C. For a qmck determination, 0.5 is used for most Fe, Cr, Ni, Mo, and Co alloy studies. Generally, the accuracy of the corrosion rate calculation is dependent upon the degree of linearity of the second cathodic curve when it is less than... 

B is the potential of the reference electrode, without whose identification the potential U is undefined. Potentials are conveniently calculated against a standard reference value. Section 3.2 contains further details on reference electrodes and conversion factors. Section 3.3 describes practical methods for measuring potential in the case of flowing currents. 

Table 2-1 Conversion factors and standard potentials for electrochemical metal-metal ion reactions...

The thionine reduction prodnct TH is anodically reoxidized to thionine, while the Fe ions are cathodically rerednced to Fe ions. Thns, the chemical composition of the system will not change dnring cnrrent flow. The potential difference between the electrodes that can be used to extract electrical energy is 0.2 to 0.4 V under current flow. The conversion factor of Inminous to electrical energy is very low in such cells, about 0.1%. This is due to the numerous side reactions, which drastically lower the overall efficiency. Moreover, the stability of such systems is not high. Therefore, the chances for a practical use are not evident so far. 

It is important to recognize that establishing a model reference material, such as the protein-embedding model described above, while essential, is just the first step for standardization of IHC. Further studies will be required to develop mathematically conversion factors, and to explore the potential utility and limitations of this approach for different proteins that are of clinical interest, as diagnostic, prognostic, or predictive markers, as described above.1012... 

For quantitative considerations it is convenient to use atomic units (a.u.), in which h = eo = me = 1 (me is the electronic mass) by definition. They are based on the electrostatic system of units so Coulomb s law for the potential of a point charge is = q/r. Conversion factors to SI units are given in Appendix B here we note that 1 a.u. of length is 0.529 A, and 1 a.u. of energy, also called a hartree, is 27.211 eV. Practically all publications on jellium use atomic units, since they avoid cluttering equations with constants, and simplify calculations. This more than compensates for the labor of changing back and forth between two systems of units. 

Calculated from Ionization potentials of atoms and atomic ions in the CRC Handbook of Chemistry and Physics [8] Conversion factor 1 hartree = 27.2114 eV... 

Taken as the appropriate sums of experimental ionization potentials [80], with a change in sign, using the conversion factor 1 au = 27.2106 eV. 

Thus at 25 °C potentials may be regarded as low or high, depending on whether they are less or more than about 25 mV. The factor (eyp/kBT) appears often in double-layer calculations, so this conversion factor is worth remembering. The relationship of (kBT/e) to (RT/ ) was noted in Section 11.2. 

In equation (18.1), E1 is the standard potential and is a constant that includes all other potentials, R is the ideal gas constant, T is the temperature, z is the charge carried by ion i to be measured and whose activity is a, F represents Faraday s constant and 2.303 is the logarithmic conversion factor. 

Valuer in kcal/moie. The values are obtained from the ionization potentials in Charlotte E. Moore, Atomic Energy Levels as Derived from the Analyses of Optical Spectra (Circular of the National Bureau of Standards 467, Government Printing Office, Washington, D. C.f 1949-1958, vol. Ill), by multiplying by the conversion factor from electron volts to kcal/mole, 23.053. 

Other units are more convenient when we are dealing with individual photon energies. It is common to use the electron volt (eV), equal to the kinetic energy imparted to an electron when it is accelerated in a potential of 1 V. The conversion factor between electron volts and joules is numerically equal to the charge on an electron ... 

Conversion factors for global warming potential (GWP) are expressed in terms of C02 equivalency (kg C02 equivalent), as given in Table 4. Using GWP values, emissions to the air of various substances can be converted to an equivalent C02 global-warming effect by means of the following formula ... 

Half-wave potential (-E1/2) vs. saturated calomel electrode (SCE). Values vs. Ag AgCl or Fc /Fc have been converted to vs. SCE using a conversion factor of 0.045 V or 0.49, respectively [96]. bDMF = dimethylformamide, DMSO = dimethylsulfoxide, DCM = dichloromethane, DCB = dichlorobenzene, THF = tetrahydrofuran, TBAP = tetrabutyl ammonium perchlorate, TBABF4 = tetrabutylammonium tetrafluoroborate, t-butyl = tert-butyl... 

Using the result obtained by Bull and Gortner [J. Phys, Chem, 36, 111 (1932)], that SIP for the streaming of 2 X 10 N sodium chloride through a diaphragm of quartz particles is about 25 millivolts per cm. of mercury pressure, calculate the approximate specific surface conductance of the solution used. Compare the result with the normal value for sodium chloride at the same concentration. The viscosity and dielectric constant of the solution may be assumed to be the same as for water, and the zeta-potential may be taken as 0.05 volt. (Care should be exercised in the matter of units, use being made of the conversion factors in Table I.)... 

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