Observed experimental results

The BDE theory does not explain all observed experimental results. Addition reactions are not adequately handled at all, mosdy owing to steric and electronic effects in the transition state. Thus it is important to consider both the reactivities of the radical and the intended coreactant or environment in any attempt to predict the course of a radical reaction (18). AppHcation of frontier molecular orbital theory may be more appropriate to explain certain reactions (19). 

It appears therefore that our proposed mechanism is sufficient to explain the observed experimental results. However, if we had assumed dimerization from a triplet state precursor,... 

The mechanism of the chemiluminescent reactions between alkyl halides and electrogenerated aromatic hydrocarbon radicals (cf. p. 119) has been elucidated in more detail 213>. The proposed general mechanism is consistent with the observed experimental results ... 

Indeed, the equation is consistent with the observed experimental results, except in the case of [OH-]. They explained the discrepancy by the fact that the concentration of OH- is regulated by formate anion buffer via reaction with CO, thereby maintaining the overall water-gas shift reaction rate to be essentially independent of base. 

While the detailed calculations gave energies and widths in reasonable agreement with the observed experimental results, they did not provide a simple physical picture of why the He spectrum was the way it was. To address this issue Macek described the He atom using hyperspherical coordinates. In this approach, the two electrons, each described by three coordinates, are replaced by an equivalent single particle in six dimensions.8,9 In Fig. 23.3 we show the He atom in which rt and r2 are the vectors from He2+ to each of the two electrons. The hyperradius Rh is defined by... 

As early as 1943, Sommer (101) reported the existence of a stoichiometric compound CsAu, exhibiting nonmetallic properties. Later reports (53, 102, 103,123) confirmed its existence and described the crystal structure, as well as the electrical and optical properties of this compound. The lattice constant of its CsCl-type structure is reported (103) to be 4.263 0.001 A. Band structure calculations are consistent with observed experimental results that the material is a semiconductor with a band gap of 2.6 eV (102). The phase diagram of the Cs-Au system shows the existence of a discrete CsAu phase (32) of melting point 590°C and a very narrow range of homogeneity (42). 

Moreover, in the physical world, the observed experimental results are biased by the presence of experimental errors, so that the concept of truth must be intended in a less strong sense. Finally, a theory Th is not a simple statement but rather a complex set of hypotheses (in some case not all explicitly stated, but situated in the background of our knowledge). If the theory disagrees with experiments, which of the hypotheses is falsified by the experiment ... 

The assumption that the fraction (1-Hce) of external catalyst surface is dry, as used by some other investigators (11), results in a very large B1q which cannot explain or even match the observed experimental results. Dryout of a catalyst surface appears possible only when much larger temperature gradients are present. On the other hand the assumption of riCE= 1 everywhere leads to unrealistic dependence of mass transfer coefficients on liquid velocity. Matching the data with a single parameter model (an overall mass transfer coefficient) results in too high an effect of velocity on such a parameter and in the loss of model predictive ability for different solvents. 

The observed experimental result that Voc decreases linearly for bulk heterojunction solar cells allows us to conclude that, at least in the high temperature range (T > 200 K), these solar cells may be described by a diode model with Ip exp(E/kT). Here E is a parameter analogous to Eg for conventional semiconductors. For conjugated polymer/fullerene bulk heterojunction solar cells, E should correspond to the energy difference between the HOMO level of the donor and the LUMO level of the acceptor components of the active layer [as also suggested by the extrapolated value of V oc(0 K)]. 

To counteract the (vexing) convection effects on kinetic experiments, Aogaki and co-workers, having developed a special electrode assembly to separate mass transport and kinetic effects, report a marked decrease in the exchange current density (about 25%) in magnetic fields imposed on a copper deposition cell. Virtually no effect on the transfer coefficient (a 0.44) was observed. Experimental results obtained in nickel-phosphorus alloy deposition, cupric ion reduction in ethylenediamine solutions, and the electrolytic reduction of acetophenone " are further demonstrations of the interaction of the magnetic fields with polarization characteristics, and point to the difficulty of fully eliminating the effect of convection and/or diffusion on electrode kinetics. 

Unfortunately the answer to our third question, that of the mechanism of coupling, is the subject of heated controversy between various research workers and undoubtedly the exact nature of the gears that couple ATP formation to electron transport are still to be worked out. However, any hypothesis has to account for a number of observed experimental results, the most important of which are ... 

Other Reducing Agents. 1,4-Dihydropyridines such as 1-benzyl-1,4-di-hydronicotinamide (BNAH) are NADH equivalents capable of acting as good electron donors. These reagents have been used in the reductive desulfonyla-tion of a-nitro,90,91 a-keto,92 and a-cyanosulfones92 under sunlight irradiation. Based on the observed experimental results, these reactions seem to proceed via radical-anion species as shown in Scheme 2.91... 

Figure 1.9 shows the Mathcad implementation of the shooting method for Stefan flow, and compares the results predicted by solving the Maxwell-Stefan equations to the experimental values obtained by Carty and Schrodt (1975). The predicted fluxes and concentration profiles are in excellent agreement with the observed experimental results. 

The model was run to simulate the transformation of n-heptane over a Y zeolite. Several sets of parameters were tried till a set resulted in a simulation which fairly coincides with the observed experimental results. 

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