Potentials for which the corresponding Schrödinger equation is maximally superintegrable in three-dimensional Euclidean space are studied. The quadratic algebra which is associated with each of these potentials is constructed and the bound state wave functions are computed in the separable coordinates.

One of the most important current objectives of the Chemical Looping Combustion (CLC) technology for gaseous fuels lies in scaling-up the aforementioned technology in the short term from 100 kW th to 10 MW th scale. In order to meet this challenge, the commercial availability of suitable multi ton-scale oxygen carrier materials at competitive price is needed. In this work, a Cu-based oxygen carrier prepared by the impregnation method using a commercial alumina as support, referred as Cu14Al_Commercial, has been developed and evaluated in a 500W th CLC pilot plant during the combustion of CH 4 at two different temperatures, i.e., 800 °C and 900 °C. The outstanding results obtained in terms of both combustion efficiency and mechanical stability have shown that the Cu14Al_Commercial impregnated oxygen carrier can be selected to upscale CLC technology for gaseous fuels.

We give a graphical prescription for obtaining and characterising all separable coordinates for which the Schrödinger equation admits separable solutions for one of the superintegrable potentials D

Lactic acid bacteria (LAB) commonly cause spoilage in minimal heat-treated vacuum-packed cured delicatessen meats. Predominant species are Lactobacillus sake and L. curvatus. LAB strains isolated from spoiled products of this type (liver sausage, ham and bologna sausage) were found to be sensitive to low nisin concentrations (maximum of 1.25 microg g(-1)). Addition of 25 microg g(-1) nisin (as Nisaplin) inhibited the growth of LAB spoilage organisms inoculated into vacuum-packed pasteurized bologna-type sausages stored at 8 degrees C. Control sausages became spoiled (>10(8) LAB CFU g(-1)) by day 7, whereas sausages containing nisin remained unspoiled for >50 days. The effect of three types of phosphates (used as emulsifiers) on nisin activity in the sausages was compared. LAB growth rate was fastest in samples containing orthophosphate, and slowest in sausages containing diphosphate. The shelf life was also greatly extended in the latter. Fat content also affected nisin activity. Nisin activity (as indicated by LAB inhibition) was greatest in samples containing 15% > 25% > 37% (wt/wt) fat. In a sausage formulation containing 37% fat and incorporating diphosphate as emulsifier, levels of nisin as low as 2.5 microg g(-1) showed antibacterial effects. A nisin level of 6.25 microg g(-1) totally inhibited LAB growth for over 4 weeks and 25 microg g(-1) for 5 weeks. Spoilage control was achieved in the same sausage formulation but with 25% (wt/wt) fat; 12.5 microg g(-1) nisin prevented LAB growth for 5 weeks.

A complete analysis of the free-field massless spin-s equations (s=0, (1)/(2) ,1) in Kerr geometry is given. It is shown that in each case the separation constants occurring in the solutions obtained from a potential function can be characterized in an invariant way. This invariant characterization is given in terms of the Killing–Yano tensor admitted by Kerr geometry.

For the design, scale-up and optimization of pressurized packed bed reactors for chemicallooping combustion, understanding of the effect of the pressure on the reactivity of the oxygen carriers is very important. In this work, the redox reactivity of CuO/Al 2 O 3 and NiO/CaAl 2 O 4 particles at elevated pressures have been measured in a pressurized hightemperature magnetic suspension balance. The experiments have demonstrated that the pressure has a negative influence on the reactivity and that this effect is kinetically controlled. The negative effect of the pressure might be caused by the decrease in the number of oxygen vacancies at higher pressures. Moreover, the reactant gas fraction has been demonstrated as an important parameter, probably related to competition between different species for adsorption on the oxygen carrier surface. These effects have been included in the kinetic model leading to a good description of the experimental results. The impact of these findings on packed-bed CLC applications with larger oxygen carrier particles has been investigated with a particle model that considers diffusion limitations and kinetics. It has been shown that the impact of diffusion limitations decrease with increasing pressure, due to the decrease in reaction rates and the increase in diffusion fluxes caused by Knudsen diffusion. The results have been validated by experiments with 1.7 mm NiO/CaAl 2 O 4 particles. These results corroborate that the selection of larger particles because of pressure drop considerations, does not lead to a large decrease in effective reaction rates, which is beneficial for packed-bed CLC applications.

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