Equivalent penetration

To allow comparison with other models and experimental data, Szekely and Evans recast the results in an alternative form. They defined an equivalent penetration, which is a direct measure of the conversion ... 

Figure 4.5-3 Equivalent penetration versus ifCgo for the pore model with the following parameters ...

The investigations of the metal release rates of Inconel 600 and Inconel 690 reported by Beslu et al. (1986) yielded results which were somewhat different from those of Lister and Davidson mentioned above. Their experiments, also using radioindicator techniques, were carried out in the Corele loop, a so-called zero release loop made almost completely of Zircaloy-4 and titanium. The equivalent penetrations of both Inconel alloys obtained by measuring the cobalt release were lower by a factor of 2 to 8 than Ae data reported by Lister and Davidson (1989), when normalized to an exposure period of 1000 hours. The measured cobalt release from Inconel 600 was hi er by about a factor of 2 than that from Inconel 690, with this difference being largely independent of the experimental conditions applied such as flow rate, temperature and solution pH. Moreover, the cobalt release rates measured by Beslu et al. (1986) did not decrease with time but remained... 

The corrosion of the stainless steel 304SS, as well as of Stellite 6, under BWR conditions was studied in detail by Lister and Davidson (1989) using the same experimental setup as for the corresponding experiments under PWR conditions (see Section 4.4.3.2.). The results of these investigations concerning stainless steel 304SS are shown in Fig. 4.43.a. in the form of equivalent penetrations (see Section 4.4.3.2.) over the experimental period of 2000 hours. Using log-log coordinates, cobalt shows an almost linear increase which can be described by the equation... 

Similar to PWR conditions, cobalt shows a preferential release to the coolant as compared to iron, indicating a comparatively weak cobalt retention in the oxide layers formed on the surfaces of the materials. Furthermore, the results show a chromium release which initially increases more than linearily with time and a somewhat irregular Co release behavior which was possibly influenced by errors in the measurement of the very low Co activity concentrations present in the experimental solutions. Since the °Co release rate is almost constant over time, the equivalent penetration under BWR operating conditions is lower than that under PWR conditions for the time period of the experiments however, when integrated over the 30-year operational life of the plant, the Co release under BWR conditions is significantly higher than that under PWR operating conditions. 

International Rubber Hardness. The International mbber hardness test (ASTM D1415) (2) for elastomers is similar to the Rockwell test ia that the measured property is the difference ia penetration of a standard steel ball between minor and major loads. The viscoelastic properties of elastomers require that a load appHcation time, usually 30 seconds, be a part of the test procedure. The hardness number is read directly on a scale of 0 to 100 upon return to the minor load. International mbber hardness numbers are often considered equivalent to Durometer hardness numbers but differences ia iadenters, loads, and test time preclude such a relationship. 

In a detersive system containing a dilute surfactant solution and a substrate bearing a soHd polar sod, the first effect is adsorption of surfactant at the sod—bath interface. This adsorption is equivalent to the formation of a thin layer of relatively concentrated surfactant solution at the interface, which is continuously renewable and can penetrate the sod phase. Osmotic flow of water and the extmsion of myelin forms foHows the penetration, with ultimate formation of an equdibrium phase. This equdibrium phase may be microemulsion rather than Hquid crystalline, but in any event it is fluid and flushable... 

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... 

Type and specifications on fan driver, gear types, pow er voltage, phase, cycles. Motors should at least meet specifications equivalent to totally enclosed, fan cooled, or if in explosive hazardous area, TEFC Class I, Group D (except this not acceptable in hydrogen or acetylene atmosphere). Due to moisture conditions around this equipment, it should be protected against moisture penetration and corrosion. 

Corrosion rates in normal industrial atmospheres measured as loss of weight over a period are extremely uniform among the various alloys. Table 4.19, last column, gives the corrosion rates (in g m d" ) for a number of alloys determined at Clifton Junction in recent years. The highest value recorded (0-4 g m d ) is equivalent to a rate of penetration of 0-076 mm/y, which is appreciably less than that of mild steel. 

Material Density (g cm ) Penetration equivalent to a corrosion rale of 1 mdd ... 

Corrosion Rate the rate at which a corrosion reaction proceeds. It may be expressed as a rate of penetration mm y", /xm s etc. (inches per year or ipy is still sometimes used), or as a rate of weight loss per unit area, for example g m" d", mg dm d (mdd) etc. It may also be expressed as the equivalent current density. 

These equations are equivalent, but the first converges rapidly for short times and the second for long times. The equations clearly show that for short times the penetration theory is approached ... 

In a gas-liquid contactor, a pure gas is absorbed in a solvent and the Penetration Theory provides a reasonable model by which to describe the transfer mechanism. As fresh solvent is exposed to the gas, the transfer rate is initially limited by the rate at which the gas molecules can reach the surface. If at 293 K and a pressure of 1 bar the maximum possible rate of transfer of gas is 50 m3/m2s, express this as an equivalent resistance, when the gas solubility is 0.04 kmol/m3. 

Vapor-phase fuel-distribution image converted to an equivalence-ratio field downstream of the maximum liquid-phase fuel penetration. Quantitative planar images are obtained in the optical engine using PLRS. (From Espey, C., Dec, J.E., Litzinger, T.A., and Santavicca, D.A., Combust. Flame, 109,65,1997.)... 

---