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Micro-reversibility

The Ci bidentate ligand system may be as simple as a chiral monophosphine and a chloride ion, as shown in Figure 13.12. Suppose that in a P-X ligand system the nucleophilic attack takes place at the position trans to the phosphine, then we expect on the basis of micro reversibility that also the... [Pg.279]

This property ensures that expression (11) satisfies the micro-reversibility principle [27]. Note that this result is maintained if the TJJ are kept in (6) and (9). Expression (5) of T b deserves a few comments. First, T b appears independent of the zero of energy of H due to the second term of the numerator [27]. Secondly, according to the Wolfsberg—Helmholz approximation [28] ... [Pg.9]

In equilibrium of redox reactions, the Fermi level of the electrode equals the Fermi level of the redox particles (ckm) = panodic reaction current equals, but in the opposite direction, the cathodic reaction current (io = io = io). It follows from the principle of micro-reversibility that the forward and backward reaction currents equal each other not only as a whole current but also as a differential current at constant energy level e io(e) = tS(e) = io(e). Referring to Eqns. 8-7 and 8-8, we then obtain the exchange reaction ciurent as shown in Eqn. 8-18 ... [Pg.240]

In order to determine whether the ROP of lactones into the corresponding aliphatic polyesters is possible, thermodynamics have to be taken into account. The ROP follows the micro-reversibility rule according to (1) ... [Pg.177]

The principle of detailed balance (and the micro reversibility) [48] requires that 2D exchange spectrum A Tm) is always symmetric. The matrix A(0) represents a 2D exchange spectrum recorded at = 0. It is a diagonal... [Pg.276]

McWhorter S, Soper SA. Conductivity detection of polymerase chain reaction products separated by micro-reversed-phase liquid chromatography. Journal of Chromatography A 883,1-9, 2000. [Pg.230]

Partly ionized gas or vapour is called a plasma. It contains atoms, molecules, and ions from which some fraction may be in excited states, and free electrons. Several theoretical models have been presented to describe a plasma. One of these is the so called Thermal Equilibrium Theory, which is based on the micro reversible principle. According to this principle, each energy process is in equilibrium with a reverse process. For example, the number of transitions per time unit from the state f to the state (absorption) is exactly the same as the number of the reverse transitions (emission). According to Maxwell, the microscopic states of the plasma at thermal equilibrium may be calculated on the basis of the temperature, which is the only variable. The number of particles (dA) with the speed between v dv is ... [Pg.29]

If the tissue component is very complex, or if the peptide of interest is only a minor component of the sample, a fractionation by means of (micro-) reversed-phase liquid chromatography should be earned out The collected fractions may then be assayed by mass spectrometry. [Pg.224]

Correa, R.A., Ferras, V., Medvedovici, A., Sandra, P., Ceme, K., and David, F. (1999) Positional and Configurational Separation of Fatty Acid Isomers by Micro Reversed-Phase Liquid Chromatography with an Ag -containing Mobile Phase, J. Chromatogr. A... [Pg.60]

Micro-reversibility requires that there be no difference in the values of Zy and Zji and we use (Zy +Zjj)/2 for evaluating the solute partition function on surface (this prevents efots of errors from numerical integration). [Pg.223]

While the choice of a good proposal density is essential to improve the sampling efiflciency of the algorithm, another approach to improve RQMC is to study the quality of the target distribution 17. In fact, to obtain good estimates of some properties, it is important to sample reptiles from 71 for large value of L. One problem of RQMC is that the propagator G only satisfies the micro-reversibility... [Pg.333]

The individual membrane filtration processes are defined chiefly by pore size although there is some overlap. The smallest membrane pore size is used in reverse osmosis (0.0005—0.002 microns), followed by nanofiltration (0.001—0.01 microns), ultrafHtration (0.002—0.1 microns), and microfiltration (0.1—1.0 microns). Electro dialysis uses electric current to transport ionic species across a membrane. Micro- and ultrafHtration rely on pore size for material separation, reverse osmosis on pore size and diffusion, and electro dialysis on diffusion. Separation efficiency does not reach 100% for any of these membrane processes. For example, when used to desalinate—soften water for industrial processes, the concentrated salt stream (reject) from reverse osmosis can be 20% of the total flow. These concentrated, yet stiH dilute streams, may require additional treatment or special disposal methods. [Pg.163]

For a given amplitude of the quasi-elastic release wave, the more the release wave approaches the ideal elastic-plastic response the greater the strength at pressure of the material. The lack of an ideally elastic-plastic release wave in copper appears to suggest a limited reversal component, however, this is much less than in the silicon bronze. Collectively, the differences in wave profiles between these two materials are consistent with a micro-structurally controlled Bauschinger component as supported by the shock-recovery results. Further study is required to quantify these findings and... [Pg.209]

Indian Ion Exchange and Chemical Industries - Produces reverse osmosis and demineralization systems, base exchange softeners, clarifiers and filters, degassers and de-aerators, filtration and micro filtration systems, effluent treatment plant...http //www.indianionexchange.com. ... [Pg.440]

Most of the optical-alignment systems incorporate a micro-processing unit, which eliminates recording errors commonly found with reverse-dial indicator and rim-and-face methods. Optical systems automatically maintain the proper orientation and provide accurate offset and angularity data, virtually eliminating operator error. [Pg.924]

Finiteness is the basic assumption a finite total volume of space-time and a finite amount of information in a finite volume of space-time. We require universality, of course, since we know that without it nothing much of interest can happen. We can also take a strong cue from our own universe, which allows us to build universal computers. If the underlying micro-physics was not universal we would not be able to do this. Reversibility is desirable because it ensures a strict conservation of information and can be used to create systems that conserve various quantities such as energy and angular momentum despite underlying anisotropies. [Pg.666]

Dilute solutions of antimony(III) and arsenic(III) (ca 0.0005M) may be titrated with standard 0.002 M potassium bromate in a supporting electrolyte of 1M hydrochloric acid containing 0.05 M potassium bromide. The two electrodes are a rotating platinum micro-electrode and an S.C.E. the former is polarised to +0.2 volt. A reversed L-type of titration graph is obtained. [Pg.634]

The titrations so far discussed in this chapter have been concerned with the use of a reference electrode (usually S.C.E.), in conjunction with a polarised electrode (dropping mercury electrode or rotating platinum micro-electrode). Titrations may also be performed in a uniformly stirred solution by using two small but similar platinum electrodes to which a small e.m.f. (1-100 millivolts) is applied the end point is usually shown by either the disappearance or the appearance of a current flowing between the two electrodes. For the method to be applicable the only requirement is that a reversible oxidation-reduction system be present either before or after the end point. [Pg.635]

The quality and quantity of sites which are capable of reversible lithium accommodation depend in a complex manner on the crystallinity, the texture, the (mi-cro)structure, and the (micro)morphology of the carbonaceous host material [7, 19, 22, 40-57]. The type of carbon determines the current/potential characteristics of the electrochemical intercalation reaction and also potential side-reactions. Carbonaceous materials suitable for lithium intercalation are commercially available in many types and qualities [19, 43, 58-61], Many exotic carbons have been specially synthesized on a laboratory scale by pyrolysis of various precursors, e.g., carbons with a remarkably high lithium storage capacity (see Secs. [Pg.386]


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See also in sourсe #XX -- [ Pg.275 ]




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