Use of a rotating disc reactor to investigate the heterogeneously catalysed oxidation of cinnamyl alcohol in toluene and ionic liquids

To evaluate the effect of mass transfer limitations in the three-phase oxidation of cinnamyl alcohol carried out in toluene and an ionic liquid (1-butyl-3-methyl-imidazolium bis(trifluoromethylsulphonyl)imide), studies have been performed in a rotating disc reactor and compared with those carried out in a stirred tank reactor where mass transfer effects are considered negligible. High catalyst efficiencies are found in the stirred tank reactor with the use of both ionic liquid and toluene, although there is a decrease in rate for the ionic liquid reactions. In contrast, internal pore diffusion limits the reaction in both solvents in the rotating disc reactor. This mass transfer resistance reduces the problem of overoxidation of the metal surface when the reaction is carried out in toluene, leading to significantly higher rates of reaction than expected, although at the cost of decreased selectivity.

Noninvasive Detection of Brushless Exciter Rotating Diode Failure

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Shifts in electron capture to the continuum at low collision energies: Enhanced role of target postcollision interactions

Measurements of electron velocity distributions emitted at 0degrees for collisions of 10- and 20-keV H+ incident ions on H-2 and He show that the electron capture to the continuum cusp formation, which is still possible at these low impact energies, is shifted to lower momenta than its standard position (centered on the projectile velocity), as recently predicted. Classical trajectory Monte Carlo calculations reproduce the observations remarkably well, and indicate that a long-range residual interaction of the electron with the target ion after ionization is responsible for the shifts, which is a general effect that is enhanced at low nuclear velocities.

Comparison of LIMPET contra-rotating wells turbine with theoretical and model test predictions

The performance of the contra-rotating Wells turbine installed in the LIMPET wave power station is compared to the predicted performance from theoretical analysis and model tests. A reasonable agreement was found between the predicted and measured turbine damping characteristic, however the turbine efficiency was found to be poorly predicted. It is postulated that this is due to the unsteady nature and mal-distribution of flow through the LIMPET turbine, which were not considered in the predictions. It is suggested that the reduced performance of the contra-rotating Wells turbine makes biplane or monoplane Wells turbines with guide vanes better solutions for OWC's.

The Kitai criterion and backward shifts

It is proved that for any separable infinite dimensional Banach space X, there is a bounded linear operator T on X such that T satisfies the Kitai criterion. The proof is based on a quasisimilarity argument and on showing that I + T satisfies the Kitai criterion for certain backward weighted shifts T.

Survival of juvenile European eels (Anguilla anguilla) transferred among salinities, and developmental shifts in their salinity preference

After their oceanic migration, juvenile European eels Anguilla anguilla enter estuaries as glass eels, develop into pigmented elvers and migrate into fresh water. Fisheries often transfer such eels abruptly between salinities, principally glass eels and elvers from estuarine to fresh water. It is usually assumed that survival rates are high, but this required systematic investigation. Survival was found to be 100% over 21 days of glass eels and semipigmented elvers transferred abruptly from estuary conditions into fresh water, 50% sea water and full sea water. Fully pigmented elvers, however, showed significantly reduced survival when transferred into sea water. Salinity preference experiments with juvenile eels have historically been inconclusive. Here, in a choice chamber design, a clear developmental shift in salinity preference was found, with glass eels preferring 100% sea water, semipigmented elvers showing no clear preference and fully pigmented elvers preferring fresh water. We conclude that eel fisheries enhancement by abrupt transfer of juveniles among salinities is largely vindicated. In addition, developmental shifts in salinity preference have been clarified and this aids in the interpretation of eel migration patterns.

Use of a batch rotating photocatalytic contactor for the degradation of organic pollutants in wastewater

Aqueous solutions of a chlorinated VOC, 3,4-dichlorobut-1-ene, as well as other pollutants, may be mineralised to carbon dioxide, water and hydrochloric acid using a sealed rotating photocatalytic reactor. The effect of pH, dissolved oxygen concentration, light intensity, pollutant concentration and rotation speed on the degradation rate have been investigated as well as competition kinetics with methanol. This reactor may be optimised to minimise competition effects in mixed solutions. (C) 2001 Elsevier Science B.V. All rights reserved.