Experimental verification

The polarization characteristic of a partially covered inert macroelectrode is easy to determine, but it is very difficult or even impossible to do the same for microelectrodes placed on it. On the other hand,30 the morphology of metal electrodeposits indicates the conditions of deposition. Hence, the type of process control on the microelectrodes can be derived from their morphology and correlated with the polarization curve for the partially covered macroelectrode. 

There are two conditions under which the particles of active metal placed on the surface of a macroelectrode can represent microelectrodes. The first condition is that the substrate is conducting but inert relative to the process under consideration. The second one is that the grains are sufficiently small to permit activation control of the electrochemical process on them, making thus, mixed overall control, as in the case of the tips of growing dendrites,11,12,31 or during the induction time of the formation of spongy deposits.32-34 

As already stated, the nuclei behave as microelectrodes in the initial stage of electrodeposition of metals onto inert substrates.33 If nucleation exclusion zones around nuclei are formed,35,36 an inert substrate can be partially covered even at long deposition times, due to the nucleation exclusion zones overlapping, which results in the formation of granular electrodeposits.37,38 In this way, a granular 

The electrolyte solutions used in further experiments were 0.5 M AgN03 in 0.2 M HNO3 (nitrate bath) and 0.1 M AgN03 in 0.5M (NH4)2S04 (ammonium bath). The overpotential was increased from initial to the final value and held for 30 s before measurement in all cases during the polarization measurements. 

The polarization curves on platinum electrodes were very similar to those obtained on graphite ones.7 

Experiments for verifying the efficiency of heat transfer in the dilute phase were carried out in the equipment shown in Fig. 11 (Kwauk and Tai, 1964). It consisted of two vertical heat transfer columns, i.d. = 300 mm for 

Solids temperature was measured at various heights by intercepting receptacles, each of which contains a bare thermocouple which follows the solids temperature when turned upright to collect the solids, and measures the gas temperature when the solids are dumped by simply turning the receptacles 180°. 

Experimental results for particles in the millimeter range are shown in Fig. 12 in terms of unitary heat transfer height z/TV for different average particle diameters for both empty columns and columns with internal baffles. The various data give a range ofNH values between 2 and 7 for the 7.2-m experimental apparatus, corresponding to particle-to-gas heat transfer coefficients between 300 and 1,000 kcal/irf hr °C. The measured pressure drops for the two columns were of the order of 10 mm water gage. 

As follows from the model, high activation energy of the chemical reaction is an important prerequisite for intensive regime of the electrolysis. Thus, the developed theoretical approach was checked in experiments on the electrolysis of KF-KBF4 melts with graphite anode [32]. The ability of boron to increase the activation energy of thermal destmction of carbon compounds was taken into consideration when choosing the molten system. 

Lead accumulator battery-rheostat was chosen as power supplier. The output voltage and short circuit current were up to 60 V and 50 A accordingly. 

The experimental cell was used, offering the possibility to take samples of anode gases for chromatographic and chemical analysis by the method described in [33], The anode was a graphite cylinder with a thermocouple positioned in a weU inside for measurement of temperature. Temperature differences were measured with differential thermocouple, with one jtmction being inside the anode and the other junction in the bulk electrolyte. Other experimental details can be found elsewhere [32]. 

Long-term electrolysis of KF-KBF4 melt was performed at 670 °C with small initial additions (1-2 wt%) of anhydrous boron oxide B2O3. 

Further on, the situation is developing in the following way. After 2-3 days of such operation, delays occur in the intermediate region II while the system passes to the conditions of common anode effect I. Upon a time, these delays become more and more durable, and then osciUatimis appear in the region II, as shown in Fig. 5.17. Oscillations vanish after another 3-5 h of the electrolysis, and then, a few hours later, the system jumps into the conditions of intensive regime represented by line III in Fig. 5.16. Finally, after 4—5 days operation, the anode 

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This work presents the theoretieal results and their experimental verifications concerning two possible methods for predicting the material discontinuities shape and severity. The methods are developed for the case of the eddy current transducer with orthogonal coils, for two situations for long crack-tjfpe discontinuities, a metod based on the geometrical diffraction has been used, while in the ease of short discontinuities the holographic method is prefered. 

The uncertainties in choice of potential function and in how to approximate the surface distortion contribution combine to make the calculated surface energies of ionic crystals rather uncertain. Some results are given in Table VII-2, but comparison between the various references cited will yield major discrepancies. Experimental verification is difficult (see Section VII-5). Qualitatively, one expects the surface energy of a solid to be distinctly higher than the surface tension of the liquid and, for example, the value of 212 ergs/cm for (100)... 

A rather different method from the preceding is that based on the rate of dissolving of a soluble material. At any given temperature, one expects the initial dissolving rate to be proportional to the surface area, and an experimental verification of this expectation has been made in the case of rock salt (see Refs. 26,27). Here, both forward and reverse rates are important, and the rate expressions are... 

This can be illustrated by showing the net work involved in various adiabatic paths by which one mole of helium gas (4.00 g) is brought from an initial state in whichp = 1.000 atm, V= 24.62 1 [T= 300.0 K], to a final state in whichp = 1.200 atm, V= 30.7791 [T= 450.0 K]. Ideal-gas behaviour is assumed (actual experimental measurements on a slightly non-ideal real gas would be slightly different). Infomiation shown in brackets could be measured or calculated, but is not essential to the experimental verification of the first law. 

Equation (A2.1.21) includes, as a special case, the statement dS > 0 for adiabatic processes (for which Dq = 0) and, a fortiori, the same statement about processes that may occur in an isolated system (Dq = T)w = 0). If the universe is an isolated system (an assumption that, however plausible, is not yet subject to experimental verification), the first and second laws lead to the famous statement of Clausius The energy of the universe is constant the entropy of the universe tends always toward a maximum. ... 

A theoretical basis for the law of corresponding states can be demonstrated for substances with the same intemiolecular potential energy fimction but with different parameters for each substance. Conversely, the experimental verification of the law implies that the underlying intemiolecular potentials are essentially similar in fomi and can be transfomied from substance to substance by scaling the potential energy parameters. The potentials are then said to be confomial. There are two main assumptions in the derivation ... 

Li Y L ef al 1995 Experimental verification of a new mechanism for dissociative chemisorption atom abstraction Phys. Rev. Lett. 74 2603-6... 

A recent suggestion has been to use plants to stimulate the microbial degradation of the hydrocarbon (hydrocarbon phytoremediation). This has yet to receive clear experimental verification, but the plants are proposed to help deUver air to the soil microbes, and to stimulate microbial growth in the rhizosphere by the release of nutrients from the roots. The esthetic appeal of an active phytoremediation project can be very great. 

Seed Regeneration. The objectives of the seed regeneration program were to provide experimental verification of the feasibiUty of one of the seed regeneration processes which have been selected for first commercial use. The specific process under evaluation was the Econoseed process (Fig. 11) (61). A 5 MW POC facihty was in operation in Capistrano, California, and produced over 6 t of potassium formate seed, which was regenerated from spent seed, ie, K SO, obtained from CFFF tests. 

J. Siler, "Reverse Osmosis Membranes-Concentration Polarization and Surface Fouling Predictive Models and Experimental Verifications," dissertation. University of Kentucky, Lexington, Ky., 1987. 

Cold fusion has been reported to result from electrolyzing heavy water using palladium [7440-05-3] Pd, cathodes (59,60). Experimental verification of the significant excess heat output and various nuclear products are stiU under active investigation (61,62) (see Eusion energy). 

The work of adhesion was determined from the a versus P measurements (see Eq. 11). The work of adhesion between two rubber spheres was found to be 71 4 mJ/m. The work of adhesion reduced to 6.8 0.4 mJ/m in the presence of 0.01 M solution of dodecyl sulfate. Using these measurements of adhesion between rubber in air and a surfactant solution, Johnson et al. [6] provided the first direct experimental verification of the Young s equation (Eq. 40). They also measured... 

Tones, W. W. and R. D, Peacock, 1994 Refinement and Experimental Verification of a Model for Fire Growth and Smoke Transport, 2nd lAFSS Meeting. 

Mathews, H.B., Miller, S.J. and Rawlings, J.B., 1996. Model identification for crystallization theory and experimental verification. Powder Technology, 88, 221-235. 

Experimental verification of existence of metallic and semiconducting CNTs... 

S. G. Mueller, R. Eckstein, D. Hofmann, L. Kadinski, P. Kaufmann, M. Koelbl, E. Schmitt. Modelling of the PVT-SiC bulk growth process taking into account global heat transfer, mass transport and heat of crystal-Uzation and results on its experimental verification. Mater Sci Eorum 0 51, 1998. 

Most of the synthetic work directed toward the higher annulenes was caiiied out by Franz Sondheimer and his students, first at Israel s Weizmann Institute and later at the University of London. Sondheimer s research systematically explored the chemistry of these hydrocarbons and provided experimental verification of Hiickel s rule. 

Discarding Liebig s theoiy as worthless because it could not be subjected to experimental verification, OstvUd contended that a catalyst merely sped up a reaction that was already occurring at a very slow rate. He also indicated that a catalyst cannot change the equilibrium composition. By analogy, he considered... 

With remarkable accuracy, Democritus in the fifth century B.C. set the stage for modem chemistry. His atomic theory of matter, which he formulated without experimental verification, still stands, more or less intact, and encapsulates the profound truth that nature s stunning wealth boils down to atoms and molecules. As science uncovers the mysteries of the world around us, we stand ever more in awe of nature s ingenious molecular designs and biological systems nucleic acids, saccharides, proteins, and secondary metabolites are four classes of wondrous molecules that nature synthesizes with remarkable ease, and uses with admirable precision in the assembly and function of living systems. 

Towards the experimental verification of the theory of ergonic distribution, five lines of investigation have been struck out. 

It has been known since the beginning of recorded history that not all liquids are completely miscible with one another. But only in recent times have we learned that gases may also, under suitable conditions, exhibit limited miscibility. The possible existence of two gaseous phases at equilibrium was predicted on theoretical grounds by van der Waals as early as 1894, and again by Onnes and Keesom in 1907 (see R8). Experimental verification, however, was not obtained until about forty years later, primarily by Krich-evsky, Tsiklis, and their co-workers in Russia (see Gl, SI), by Lindroos and Dodge at Yale (L5), and, more recently, by de Swaan Arons and Diepen at Delft (D3). 

Experimental verification of the universal wing shape (4.90) is not only an important way of checking the dominant role of spectral exchange but also an additional spectroscopic way to measure energy relaxation time even before collapse (in rare gases). Unfortunately it has not been done yet due to lack of accuracy far beyond the spectral edge. 

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