Density effective 347, true

Figure 15K represents a typical response of the electrochemical inteqjhase to constant current pulses of different magnitude. For a sufficiently low current density, a true steady state is reached before the effect of diffusion limitation can be observed. As the current density is increased, diffusion limitation sets in earlier. Extrapolation of the potential to zero time can sometimes be employed to estimate a correct value of the activation overpotential, as shown in this Fig. 15K. If such extrapolation is not practical, one may use a higher concentration of the reactant, to increase the ratio x /x (i.e., to...

The effective density of a particle is the particle mass divided by the volume of liquid it displaces (Archimedes density). Its true density is the particle mass divided by the volume it would occupy if it were compressed so as to eliminate all the pores and surface fissures. Its apparent density is its mass divided by its volume, excluding open pores but including closed pores. 

Powder Density. See true density. Powdering. A process sometimes used for the on-glaze decoration of the more expensive types of pottery-ware. Colour mixed with an oil medium is first brushed on the ware, dry powdered colour then being applied to achieve a stippled effect. 

General Principles There are two main types of mass flowmeters (1) the so-called true mass flowmeter, which responds directly to mass flow rate, and (2) the inferential mass flowmeter, which commonly measures volume flow rate aud flmd density separately. A variety of types of true mass flowmeters have been developed, including the following (a) the Maguus-effect mass flowmeter, (b) the axial-flow, transverse-momentum mass flowmeter, (c) the radial-flow, transverse-momentum mass flowmeter, (d) the gyroscopic transverse-momentum mass flowmeter, aud (e) the thermal mass flowmeter. Type b is the basis for several commercial mass flowmeters, one version of which is briefly described here. 

It may be decided that the gamma prior cannot be greater than a certain value xf. This has the effect of true Ling the normalizing denominator in equation 2.6-10," and leads to equation 2.6-17, where P(x v) is the cumulative integral from 0 to over the chi-squared density function with V degrees of freedom, a is the prescribed confidence fraction, and = 2 A" (t+Tr). Thus, the effect of the truncated gamma prior is to modify the confidence interval to become an effective confidence interval of a ... 

The effects of adsorbed inhibitors on the individual electrode reactions of corrosion may be determined from the effects on the anodic and cathodic polarisation curves of the corroding metaP . A displacement of the polarisation curve without a change in the Tafel slope in the presence of the inhibitor indicates that the adsorbed inhibitor acts by blocking active sites so that reaction cannot occur, rather than by affecting the mechanism of the reaction. An increase in the Tafel slope of the polarisation curve due to the inhibitor indicates that the inhibitor acts by affecting the mechanism of the reaction. However, the determination of the Tafel slope will often require the metal to be polarised under conditions of current density and potential which are far removed from those of normal corrosion. This may result in differences in the adsorption and mechanistic effects of inhibitors at polarised metals compared to naturally corroding metals . Thus the interpretation of the effects of inhibitors at the corrosion potential from applied current-potential polarisation curves, as usually measured, may not be conclusive. This difficulty can be overcome in part by the use of rapid polarisation methods . A better procedure is the determination of true polarisation curves near the corrosion potential by simultaneous measurements of applied current, corrosion rate (equivalent to the true anodic current) and potential. However, this method is rather laborious and has been little used. 

To be effective, this method must be carried out on samples which have been blanched, and upon peas from which the skins have been removed. The heat applied in blanching drives off gases entrapped in the tissues, and removal of the skins is required to remove air that may be entrapped under them, although it materially slows up the operation and makes it very tedious. In order that there may be consistency in grading, the test must be conducted under closely standardized conditions of temperature and solution concentration. This becomes of considerable importance in borderline cases, and failure to take it into consideration no doubt accounts for some of the inconsistency in results experienced by the industry. The test is not a true measure of tenderness, in that it accounts for variation in skin texture only in so far as maturity affects skin texture. Skin texture is affected by factors other than maturity (4). Other methods for the estimation of maturity based upon density or specific gravity have been suggested by Jodidi (16) and by Lee (22). 

Elutriation differs from sedimentation in that fluid moves vertically upwards and thereby carries with it all particles whose settling velocity by gravity is less than the fluid velocity. In practice, complications are introduced by such factors as the non-uniformity of the fluid velocity across a section of an elutriating tube, the influence of the walls of the tube, and the effect of eddies in the flow. In consequence, any assumption that the separated particle size corresponds to the mean velocity of fluid flow is only approximately true it also requires an infinite time to effect complete separation. This method is predicated on the assumption that Stokes law relating the free-falling velocity of a spherical particle to its density and diameter, and to the density and viscosity of the medium is valid... 

Passivation phenomena on the whole are highly multifarious and complex. One must distinguish between the primal onset of the passive state and the secondary phenomena that arise when passivation has already occurred (i.e., as a result of passivation). It has been demonstrated for many systems by now that passivation is caused by adsorbed layers, and that the phase layers are formed when passivation has already been initiated. In other cases, passivation may be produced by the formation of thin phase layers on the electrode surface. Relatively thick porous layers can form both before and after the start of passivation. Their effects, as a rule, amount to an increase in true current density and to higher concentration gradients in the solution layer next to the electrode. Therefore, they do not themselves passivate the electrode but are conducive to the onset of a passive state having different origins. 

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