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First limit

The rate constant 2 shows a typical Arrhenius form, at least over a modest range of temperature, while k involves a combination of diffusion to the walls and a subsequent surface-phase reaction. [Pg.489]

The condition for criticality, i.e., for the first limit, will then be parametrized by ( = 0, i.e., by the condition [Pg.490]

In unstirred systems, the effective rate of diffusion will be decreased by increasing the total pressure, allowing inert gases to influence the explosion pressure. The concentration of O2 will be directly related to the partial pressure. [Pg.490]

If we ignore the effect of p on k, which may be much smaller in well-stirred systems, the ignition condition can be written as [Pg.490]


Historically, the development of the acrylates proceeded slowly they first received serious attention from Otto Rohm. AcryUc acid (propenoic acid) was first prepared by the air oxidation of acrolein in 1843 (1,2). Methyl and ethyl acrylate were prepared in 1873, but were not observed to polymerize at that time (3). In 1880 poly(methyl acrylate) was reported by G. W. A. Kahlbaum, who noted that on dry distillation up to 320°C the polymer did not depolymerize (4). Rohm observed the remarkable properties of acryUc polymers while preparing for his doctoral dissertation in 1901 however, a quarter of a century elapsed before he was able to translate his observations into commercial reaUty. He obtained a U.S. patent on the sulfur vulcanization of acrylates in 1912 (5). Based on the continuing work in Rohm s laboratory, the first limited production of acrylates began in 1927 by the Rohm and Haas Company in Darmstadt, Germany (6). Use of this class of compounds has grown from that time to a total U.S. consumption in 1989 of approximately 400,000 metric tons. Total worldwide consumption is probably twice that. [Pg.162]

The first limitation is set by the nature of random failure events. If we believe that failures occur periodically and not with equal probability in time, the premise of PM or periodic machinery maintenance is incorrect. Therefore, the only alternative is continuous monitoring. [Pg.1044]

The growth rate of a nucleation-controlled face can be expressed, within certain limits, in terms of i and g without their explicit evaluation. The first limit we shall consider is that of large g so that a nucleus, having formed, spreads rapidly to cover the substrate before another nucleation event occurs, see Fig. 3.5 a. If the substrate has a width L, then the rate of nucleation is iL and the growth rate is given by ... [Pg.243]

Ethylammoniinn niirate, l H jf HjNH tNOj, was the first limit liquid to he discovered. Its melting point of 12°C was reported in 1914 and it has since been used as a nonpolluting solvent for organic reactions and for facilitating the folding of proteins. [Pg.15]

Copper(II) ions in the presence of chloride ions are reduced at the dropping mercury electrode (dme) in two steps, Cu(II) -> Cu(I) and Cu(I) -> Cu(0) producing a double wave at -1-0.04 and 0.22 V versus sce half-wave potentials. In the presence of peroxydisulphate , when the chloride concentration is large enough, two waves are also observed the first limiting current corresponds to the reduction of the Cu(II) to Cu(I) plus reduction of a fraction of peroxydisulphate and the total diffusion current at a more negative potential is equal to the sum of the diffusion currents of reduction of Cu(II) to Cu(0) and of the peroxydisulphate. There is evidence that peroxydisulphate is not reduced at the potential of the first wave because of the adsorption of the copper(I) chloride complex at... [Pg.547]

The first limitation is related to interference of the anode and the cathode. The finite permeability of the Nation membrane to fuel and oxygen results in crossover of fuel from the anode to the cathode, and oxygen crossover in the opposite direction. This may have a significant influence on electrode kinetics. [Pg.518]

In the last section of the paper, we discuss a Bayesian approach to the treatment of experimental error variances, and its first limited implementation to obtain MaxEnt distributions from a fit to noisy data. [Pg.12]

It must be realised however (as indeed it was at the time of these experiments (53)) that the use of such studies to determine the sequence, has certain limitations. The first limitation is that nothing can be said about the role of species not detectable by EPR, such as fully reduced flavin. Secondly and more generally, it has to be assumed for both the oxidizing and reducing substrates, that each reacts with only one of the... [Pg.115]

Susenbeth A, Dickel T, Diekenhorst A and Hohler D (1999), The effect of energy intake, genotype and body weight on protein retention in pigs when dietary lysine is the first-limiting factor , J Anim Sci, 77, 2985-2989. [Pg.176]

Assuming that AE AG, the rate constants for the quenching reaction and its reverse (kj and k i in eq. 8) can be written using the theoretical results of eq. 5-7. In order to make the situation clear it is useful to consider two limiting cases. In the first limit, k i << back electron transfer to give the... [Pg.157]

First law of thermodynamics, 24 645-648 First limiting amino acid, 2 601 First-order irreversible chemical kinetics, 25 286-287, 292-293 First-principle approach, in particle size measurement, 13 153 First sale doctrine, 7 793 Fischer, Emil, 16 768 Fischer carbene reaction, 24 35-36 Fischer esterification, 10 499 Fischer formula, 4 697 Fischer-Indole synthesis, 9 288 Fischer lock and key hypothesis, 24 38 Fischer-Tropsch (FT) synthesis, 6 791, 827 12 431... [Pg.361]

Attempts to gain further insight into the more detailed structure of biguanides in general, and of Paludrine in particular, were made by studies of their ultraviolet spectra, including those of simpler molecules, which may be regarded as the component parts of l-aryl-5-alkyl-biguanides (227), but the succes of this approach was at first limited (227). [Pg.32]

Again the radiative association kinetics described above allow a direct comparison for some realistic values of k and k. For most chemically activated systems at the threshold for unimolecular dissociation, the observed radiative rate constants are of the order of 10-100 s and hence are much below the values expected for k of about 10 s . Therefore, the first limit is most likely to be valid, with the interesting conclusion that the observed unimolecular dissociation rate constant will depend only on the photon density and the absorption cross section (rate constant) at a given wavelength. [Pg.76]

The first limited list proposals were annoimced in November 1984 and proposed that a list of 31 products was adequate to meet all clinical needs in the seven therapeutic areas of indigestion remedies, laxatives, analgesics, cold and cough remedies, vitamin preparations, tonics and benzodiazepines. In the event, when the proposals became operational in April 1985, the initial list had been expanded to 129 products, and later to 160 products. The remaining products reimbursable on the NHS could only be dispensed if prescribed by their generic as opposed to their brand names. [Pg.711]

Composition space. It is firstly of critical importance that a well-understood and properly circumscribed composition space is defined. This is best done by considering databases for use with particular material types, for example steels, conventional Ti alloys, etc. This firstly limits the number of elements which need to be considered and also helps to define concentration limits for these elements. [Pg.330]

The important chromatographic parameter, which can directly be Obtained from the chromatogram, is the retention fiactor k. It is given by the ratio of mass of eluite bound to the stationary phase to the mass in the mobile phase and is conveniently expressed by the corresponding equilibrium concentrations and the phase ratio, When a complex formation in the mobile phase dominates, i.e., the chromatographic process can be represented by the first limiting case, the retention fiactor is obtained by combining Eqs. (SI), (65), (66), and (68) to obtain... [Pg.119]

The constants A and B can be determined from the solutions available for the simple cases in which either = 0 or uw = 0. The first limiting case corresponds to the dissolution of a planar wall in a semiinfinite liquid in steady flow (Blasius flow), while the second limit corresponds to steady-state diffusion with chemical reaction in a stagnant fluid. For Blasius flow at large Schmidt numbers [2],... [Pg.35]

First limitation immediate care is administered to the victim by nonspecialists, or even non-healthcare people. Now, there has been one dogma in France for several decades a chemical eye bum means washing with water and, above aU, not using anything else, especially no neutralizing solutions. [Pg.117]


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Behaviour of First-Order Correction to Autocatalator Stationary-States and Limit Cycles

Explosion limits first

First and second limits (lower pressures)

First kind limit

First step is rate limiting

Induction first limit

Limitations of the First Law

Limits of the First Law

Potassium first limit

The Limiting First-Order Rate Constant

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