Reaction of the N‐heterocyclic carbene, 1,3‐dimesityl‐ imidazol‐2‐ylidene,with a uranyl triflate complex,UO2(OTf)2(thf)3

The N‐heterocyclic carbene, 1,3‐dimesityl‐imidazol‐2‐ylidene (IMes) reacts with tetrahydrofuran (THF) in the presence of an oxidizing uranyl triflate complex, UO₂(OTf)₂(thf)₃ (^?OTf = ^?OSO₂CF₃), to give 1,4‐bis(1,3‐dimesityl‐2‐imidazolium)‐1,3‐butadiene bis(trifluoromethanesulfonate), formally understood as the coupling product of two equivalents of IMes with [CH?CH? CH?CH](OTf)₂. Copyright © 2005 John Wiley & Sons, Ltd.     

Multi-scan reversible cyclic voltammetry: is the ultimate condition approached and, if so, how fast?

A previous article shows that, after an infinite number of cycles, reversible cyclic voltammetry will attain an ultimate state characterized by properties that were identified in that study. Here, reversible multi-scan cyclic voltammetry has been modelled with a view to assessing the circumstances under which the ultimate state is attainable in an experimentally realistic time. The prediction has been confirmed that, under very specific conditions, the ultimate condition is attained after only a few scans. Under less restrictive conditions, one property of ultimacy is developed rapidly, but others evolve more slowly, or not at all. Modelling shows that the multi-scan voltammetric current may be analyzed into several components, of which the ultimate current is the purely periodic component.     

Perturbative QCD calculation of jet cross sections in e+e− annihilation

We calculate the α_s² to three-jet cross sections in e⁺e^? annihilation in a scheme that uses regulator masses for the infrared and collinear divergences. Using various methods to define the three-jet region, we find that the corrections to the O(α_s) cross sections are large.     

A model investigation of the acoustical performance of courtyard houses with respect to noise from road traffic

The action of courtyard houses in reducing the noise nuisance from road traffic is examined using the techniques of computer simulation and acoustic scale modelling. This building form is found to be capable of reducing the noise level experienced within a protected space (indoor or outdoor) by a significant amount. For a courtyard house a fixed distance from a roadway the most significant parameter is found to be the height of the courtyard walls. The effect of varying courtyard width and depth on the net attenuation is slight by comparison with the effect observed on varying the height of the walls.     

Attempts to measure sensitiser photophysics in opaque tissue

Diffuse reflectance laser flash photolysis has been used in an attempt to measure transient triplet spectra of the sensitisers, disulphonated aluminium phthalocyanine and porphyrin IX (derived from 5-amino laevulinic acid), in opaque tissue and models. The latter consisted of tissue phantoms; the former included rat liver and red blood cells. In all cases, triplet-triplet absorption spectra with relatively poor signal-to-noise were obtained providing some encouragement in the application of this technique to in vivo studies on photosensitisers.     

Growth of mercury electrodeposits on an inlaid disc thermodynamic theory

On the basis of the concept of interfacial energy minimization, a theoretical study has been made of the growth of liquid mercury formed by electrodeposition onto an inlaid disc. Many different growth patterns are shown to be possible, depending on the magnitudes of the specific interfacial energies of the following interfaces: mercury/solution, mercury/disc, mercury/insulator, solution/insulator, and solution/disc.