Enhanced catalytic activity of Ni on η-Al2O3 and ZSM-5 on addition of ceria zirconia for the partial oxidation of methane

peer-reviewedNickel supported on η-Al2O3 and ZSM-5(80) catalysts with and without the addition of ceria-zirconia, were prepared by co-precipitation and wet impregnation methods and used for the low temperature catalytic partial oxidation of methane (CPOM). The catalysts were tested under reaction temperatures of between 400 and 700 °C with a WHSV of 63,000 mL g−1 h−1. The activity of the catalyst was found to be dependent on the support and preparation method. The optimum catalyst composition of those tested was 10% Ni on 25%CeO2-ZrO2/ZSM-5(80), prepared by co-precipitation, where the reaction reached equilibrium conversion at 400 °C (T50% < 400 °C), which is one of the lowest temperatures reported to date. Further increases in temperature led to improved selectivity to CO reaching 60% at 600 °C. Although the observed kinetics were found to be controlled by strong adsorption of CO at lower temperature, this was an equilibrium limitation with longer time on stream experiments showing no decrease in the catalyst activity over 25 h at 400 °CACCEPTEDpeer-reviewe

Investigating the Solubility and Cytocompatibility of CaO-Na2O-SiO2/TiO2 Bioactive Glasses

This study aims to investigate the solubility of a series of titanium (TiO2)-containing bioactive glasses and their subsequent effect on cell viability. Five glasses were synthesized in the composition range SiO2-Na2O-CaO with 5 mol % of increments TiO2 substituted for SiO2. Glass solubility was investigated with respect to (1) exposed surface area, (2) particle size, (3) incubation time, and (4) compositional effects. Ion release profiles showed that sodium (Na+) presented high release rates after 1 day and were unchanged between 7 and 14 days. Calcium (Ca2+) release presented a significant change at each time period and was also composition dependent, where a reduction in Ca2+ release is observed with an increase in TiO2 concentration. Silica (Si4+) release did not present any clear trends while no titanium (Ti4+) was released. Cell numbers were found to increase up to 44%, compared to the growing control population, with a reduction in particle size and with the inclusion of TiO2 in the glass composition

Influence of particle size on the physicochemical properties and stickiness of dairy powders

peer-reviewedThe compositional and physicochemical properties of different whey permeate (WPP), demineralised whey (DWP) and skim milk powder (SMP) size fractions were investigated. Bulk composition of WPP and DWP was significantly (P < 0.05) influenced by powder particle size; smaller particles had higher protein and lower lactose contents. Microscopic observations showed that WPP and DWP contained both larger lactose crystals and smaller amorphous particles. Bulk composition of SMP did not vary with particle size. Surface composition of the smallest SMP fraction (<75 μm) showed significantly lower protein (−9%) and higher fat (+5%) coverage compared with non-fractionated powders. For all powders, smaller particles were more susceptible to sticking. Hygroscopicity of SMP was not affected by particle size; hygroscopicity of semi-crystalline powders was inversely related to particle size. This study provides insights into differences between size fractions of dairy powders, which can potentially impact the sticking/caking behaviour of fine particles during processing.ACCEPTEDpeer-reviewe