Radial dispersion in trickle-bed reactors: Comparison between sock and dense loadings

A 0.3 m diameter trickle-bed reactor filled with porous alumina cylinders is used to study the influence of the catalyst loading method on liquid distribution. The study compares the performances of the dense and the sock loading methods in terms of radial liquid spreading. Measurements were performed using two wire mesh tomography devices, placed, respectively, 0.33 and 0.96 m below the liquid distributor. The obtained results show that, in opposition to general agreement, sock packed beds seem to distribute liquid better than dense packed beds. This surprising result may be tentatively explained by a larger anisotropy of the dense loading.     

Heuristic-driven Techniques for Test Case Selection

We propose an approach to testing that combines formal methods with practical criteria, close to the testing engineer's experience. It can be seen as a framework to evaluate and select test suites using formal methods, assisted by informal heuristics. We also introduce the formalism of enriched transition systems to store information obtained during the testing phase, and to adapt classical test generation techniques to take advantage of the possibilities of the new formalism.     

Isokinetic gradient centrifugation prolongs survival of pig islets xenografted into mice

The shikimate pathway presents an attractive target for malaria chemotherapy. Three shikimic acid analogs exhibited different effects on Plasmodium falciparum growth. (6R)-6-Fluoro-shikimate and (6S)-6-fluoro-shikimate inhibited growth (50% inhibitory concentrations, 1.5 x 10(-5) and 2.7 x 10(-4) M, respectively), whereas 2-fluoro-shikimate had no effect. para-Aminobenzoic acid abrogated the inhibition, demonstrating that the shikimate pathway was specifically targeted.     

Cerumen impaction

Cerumen impaction represents the most common otologic problem encountered by physicians. It can affect up to 6% of the general population and a much higher percentage in the mentally retarded population. Cerumen is a mixture of secretory products of two glands in the external auditory canal where it serves a protective function. The external auditory canal possesses a unique anatomy and physiology that permits an efficient self-cleaning system. In most cases, a breakdown in the epithelial migration of the external auditory canal is thought to cause cerumen impaction. The management of cerumen impaction include direct removal, irrigation, and the use of cerumenolytics.