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Pure real yield

Since the volume fraction of spheres is true absorption, and disappears for any material with a purely real dielectric function, since "=0. Equations (11) and (12) validate Beer s law for dilute colloids - the absorbance is proportional to however for higher values of ... [Pg.229]

At this point it is useful to distinguish two different types of perturbation first, electric field-like perturbations yield purely real and consequently,... [Pg.191]

GP 2] [R 2] The definition of space-time yield in a micro reactor depends on the definition of the reactor volume . Owing to the large amoimt of construction material relative to the reaction channels and the neglect of some reactor parts ( abstraction to the real reaction zone ), several more or less useful definitions can be made. In the following, two definitions concerning the time yield divided by the pure reaction channel volume and the platelet volume were used. [Pg.307]

In order to obtain a definite breakthrough of current across an electrode, a potential in excess of its equilibrium potential must be applied any such excess potential is called an overpotential. If it concerns an ideal polarizable electrode, i.e., an electrode whose surface acts as an ideal catalyst in the electrolytic process, then the overpotential can be considered merely as a diffusion overpotential (nD) and yields (cf., Section 3.1) a real diffusion current. Often, however, the electrode surface is not ideal, which means that the purely chemical reaction concerned has a free enthalpy barrier especially at low current density, where the ion diffusion control of the electrolytic conversion becomes less pronounced, the thermal activation energy (AG°) plays an appreciable role, so that, once the activated complex is reached at the maximum of the enthalpy barrier, only a fraction a (the transfer coefficient) of the electrical energy difference nF(E ml - E ) = nFtjt is used for conversion. [Pg.126]

The results obtained appeared quite promising, but the real sensation was the detection of pyruvate, the salt of 2-oxopropanoic acid (pyruvic acid), which is one of the most important substances in contemporary metabolism. Pyruvic acid was first obtained in 1835 by Berzelius from dry distillation of tartaric acid. The labile pyruvate was detected in a reaction mixture containing pure FeS, 1-nonanethiol and formic acid, using simulated hydrothermal conditions (523 K, 200 MPa). The pyruvate yield, 0.7%, was certainly not overwhelming, but still remarkable under the extreme conditions used, and its formation supports Wachtershauser s theory. Cody concludes from these results that life first evolved in a metabolic system prior to the development of replication processes. [Pg.200]

The reaction rate of AHA is large enough to use centrifugal contactors. Process experiments with real SNF in a series of centrifugal contactors have demonstrated a separation of highly pure U with a yield of >99.99% (126, 183-188). The UREX+ process also enables the effective separation of Tc (189). [Pg.12]

Determination of pure component parameters. In order to use the EOS to model real substances one needs to obtain pure component below its critical point, a technique suggested by Joffe et al. (18) was used. This involves the matching of chemical potentials of each component in the liquid and the vapour phases at the vapour pressure of the substance. Also, the actual and predicted saturated liquid densities were matched. The set of equations so obtained was solved by the use of a standard Newton s method to yield the pure component parameters. Values of exl and v for ethanol and water at several temperatures are shown in Table 1. In this calculation vH and z were set to 9.75 x 10"6 m3 mole"1 and 10, respectively (1 ). The capability of the lattice EOS to fit pure component VLE was found to be quite insensitive to variations in z (6[Pg.90]

The instrumental LoDs set forth in Table 3.1 shows that inductively coupled plasma-mass spectrometry (ICP-MS) is the technique that yields the best values. It should be considered that these limits are based on pure solutions analyzed under optimal conditions. Dealing with real foodstuffs will dramatically change the picture, owing to the complexity of the matrices and contamination phenomena in the laboratory. This means that in food laboratories without clean-room facilities (which is the vast majority) the practical difference in LoDs for ET-AAS and ICP-MS will be of minor importance. The relatively poor LoDs for inductively coupled plasma-atomic emission spectrometry (ICP-AES) when compared to those of ET-AAS implies that this technique is not fit for low-level determination of many elements, for example, Cd and Pb. [Pg.75]

After the seminal work of Guggenheim on the quasichemical approximation of the lattice statistical-mechanical theory[l], various practical thermodynamic models such as excess Gibbs energies[2-3] and equations of state[4-5] were proposed. However, the quasichemical approximation of the Guggenheim combinatory yields exact solution only for pure fluid systems. Therefore one has to resort to numerical procedures to find the solution that is analytically applicable to real mixtures. Thus, in this study we present a new unified group contribution equation of state[GC-EOS] which is applicable for both pure or mixed state fluids with emphasis on the high pressure systems[6,7]. [Pg.385]

The real value of the VVittig reaction is that it yields a pure alkene of defined structure. I he C=C bond in the jiroduct is always exactly where the C=0 group was in the reactant, and no alkene isomers (except E,Z isomers) are formed. For example, Wittig reaction of cyclohexanone with methylenetriphenyl-phosphorane yields only the single alkene product methylenecyclohexane. By contrast, addition of methylmagnesium bromide to cyclohexanone, followed by dehydration wdth l OCl3, yields a roughly 9 1 mixture of two alkenes. [Pg.722]


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See also in sourсe #XX -- [ Pg.261 ]




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