Rate effect

Rate effects may not be chemical kinetic ones. Benson and co-worker [84], in a study of the rate of adsorption of water on lyophilized proteins, comment that the empirical rates of adsorption were very markedly complicated by the fact that the samples were appreciably heated by the heat evolved on adsorption. In fact, it appeared that the actual adsorption rates were very fast and that the time dependence of the adsorbate pressure above the adsorbent was simply due to the time variation of the temperature of the sample as it cooled after the initial heating when adsorbate was first introduced. [Pg.661]

Table 12 2 summarizes orientation and rate effects m electrophilic aromatic sub stitution reactions for a variety of frequently encountered substituents It is arranged m order of decreasing activating power the most strongly activating substituents are at the top the most strongly deactivating substituents are at the bottom The mam features of the table can be summarized as follows... [Pg.494]

For catalytic investigations, the rotating basket or fixed basket with internal recirciilation are the standard devices nowadays, usually more convenient and less expensive than equipment with external recirculation. In the fixed basket type, an internal recirculation rate of 10 to 15 or so times the feed rate effectively eliminates external diffusional resistance, and temperature gradients. A unit holding 50 cm (3.05 in ) of catalyst can operate up to 800 K (1440 R) and 50 bar (725 psi). [Pg.708]

In this chapter, we will review the effects of shock-wave deform.ation on material response after the completion of the shock cycle. The techniques and design parameters necessary to implement successful shock-recovery experiments in metallic and brittle solids will be discussed. The influence of shock parameters, including peak pressure and pulse duration, loading-rate effects, and the Bauschinger effect (in some shock-loaded materials) on postshock structure/property material behavior will be detailed. [Pg.187]

If two irradiations are undertaken in similar neutron spectra to the same total number of atomic displacements and at the same temperature, but at different rates (i.e., over different time intervals), the graphite sample with the shorter exposure time will show more damage (i.e., a flux or rate effect). This is because the net observed damage is a function not only of the total damage produced (dependant on the neutron dose), but also on the extent of annealing of that damage, which is... [Pg.459]

The data structure organization described above has been implemented in the BFM as well as in a very efficient off-lattice Monte Carlo algorithm, discussed in detail in the next chapter, which was modified to handle EP and used to study shear rate effects on GM [57]. [Pg.519]

FIGURE 22.8 Flow rate effect on the elution of polyacrylamide. Degradation of polymer during the analysis occurs in each case at flow rates just above those shown. Unmodified MW = 12-15 x I0 carboxyl substitution = 9.5%. , unmodified A, sheared for 30.0 min , sheared for 12 hr O, sonicated for 1.0 min O, sonicated for 5.0 min. (From Ref 23, Copyright 1988. Reprinted by permission of John Wiley Sons, Inc.)... [Pg.604]

The hydrolysis of aspirin [Eq. (6-70), R = CH3] is a classic example demonstrating a sigmoid pH-rate effect. Figure 6-13 shows this curve for trimethyl-... [Pg.283]

A further complication arises with Ingold s suggestion" that both the inductive and resonance effects are composed of initial state equilibrium displacements that reveal themselves in equilibrium properties like dipole moments and equilibrium constants and of time-dependent displacements produced during reaction by the approach of an attacking reagent, observed rate effects being resultants of both types of electronic effects. Hammett, however, claims that it is not necessary or possible to make this distinction. [Pg.323]

Mechanism Initial state Transition state Relative charge in transition state Rate effect of increase in solvent polarity... [Pg.388]

I.O. Bashkin, E.G. Ponyatovsky, O.N. Senkov, and V.Yu. Malyshev, The strain-rate effect on the hydrogen-induced workability improvement of titanium alloy VT20 at temperatures 500-800°C, Phys. Met. Metall., 69 167 (1990). [Pg.437]

Static and dynamic property The uses of these foams or porous solids are used in a variety of applications such as energy absorbers in addition to buoyant products. Properties of these materials such as a compressive constitutive law or equation of state is needed in the calculation of the dynamic response of the material to suddenly applied loads. Static testing to provide such data is appealing because of its simplicity, however, the importance of rate effects cannot be determined by this one method alone. Therefore, additional but numerically limited elevated strain-rate tests must be run for this purpose. [Pg.501]

Since industrial nitration occurs, in most cases, in two-phase systems a number of workers have investigated the kinetics in both organic and acid phases (Refs 18b, 46 81). The consensus is that nitration occurs mainly in the acid phase. In what follows we will examine reaction rate effects in industrial-type nitrations for producing TNT, NG and EGDN... [Pg.261]

TNT Reaction rate effects in the production of MNT and DNT were already examined in Section VI. Here we will examine reaction rate effects for the trinitration stage, ie, DNT - TNT... [Pg.261]

Instead or in addition, the reactants A and B may associate in a fast preequilibrium, or one of them may bind to a third component. Such interactions will exert important rate effects and for that reason must be accounted for. The existence of equilibria in which the reactants participate may translate to an important effect on the chemical mechanism or to a trivial one. Either way, the issue must be addressed to arrive at a reliable mechanism. The matter can grow complicated, in that the concentration variables that affect the rate may do so because they really do enter the mechanism, or because they participate in extraneous equilibria. Of course, they may play both roles. Sorting out these matters sounds complicated, but it is not difficult if one proceeds systematically. [Pg.126]

This equation is known as the Br0nsted-Bjerrum equation. Because y% appears in the denominator, it explicitly acknowledges the premise of TST that there is an equilibrium between the reactants and the transition state. Equation (9-27) provides the basis for understanding the direction and magnitude of rate effects arising from changes of reaction medium. This approach will be used to formulate effects of solvent and inert electrolytes in the sections that follow. [Pg.204]

Wilkinson s method for, 32-33 with respect to a species, 6 with respect to concentration, 16 with respect to time. 16 Reaction profile diagram. 84—85 Reaction rates, effect on of concentrations, 9 of ionic strength, 206-214 of light, 9... [Pg.280]

West JR, Smith HW, Chasis H. 1948. Glomemlar filtration rate, effective renal blood flow, and maximal tubular excretory capacity in infancy. J Pediatr 32 10-18. [Pg.237]

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