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Modification of conventional photoanode with oxide nanoparticles is a practical tactic to improve the performance of electrochemical devices. In this study, erbium oxide (Er2O3) nanoparticles were mixed with the TiO2 paste and photovoltaic performance of the dye-sensitized solar cell (DSSC) was investigated. The highest power conversion efficiency of 6.39% was reached with the 1 wt.% of Er2O3 in photoanode, while in the similar condition the device with the pure TiO2 photoanode achieved the power conversion efficiency of 3.54%. This improvement in the power conversion efficiency was attributed to declining in charge recombination, improved open-circuit voltage and short-circuit current due to the presence of the critical amount of Er2O3. XPS analysis confirms the structural coherence between the Er2O3 and TiO2, which enhanced the optical performance of the composite photoanode. Composite photoanodes were further characterized by FESEM-EDX, XRD, and AFM for structural and morphological studies.

Changes in physiochemical properties of spray-dried camel milk powders during storage at 11–32% RH and 37 °C over 18 weeks were investigated. The results showed that fresh camel milk powders had amorphous structure, clumsy spherical shape particles and almost 100% solubility in water. During storage at controlled low RH levels (

Water-induced crystallisation of amorphous core-cyclodextrin (CD) complex is an essential step in a solid encapsulation process and removal of added water is a challenging. Ethanol addition is expected to shorten the complex dehydration time. This study investigated crystallisation of amorphous spray-dried α-, β- and γ-CD powders by direct mixing 15% (w/w) of ethanol:water mixture (0:100, 20:80, 40:60, 60:40, 80:20 and 100:0) over 72 h period. The results showed α- and β-CD powders crystallised at all concentrations of ethanol solutions. Especially mixed with 0:100 and 20:80 ethanol:water solutions, the crystallisation behaviour of α- and β-CD powders was similar to that of commercial crystalline counterparts. γ-CD powders exhibited a crystallisation sign as mixed with 0:100 and 20:80 ethanol:water solutions only. In the study of fish oil encapsulation using the mixture of water and ethanol to induce the complex crystallisation, only γ-CD powder was able to form complex with fish oil.

Cultures of Trichodesmium from the Northern and Southern Great Barrier Reef Lagoon (GBRL) have been established in enriched seawater and artificial seawater media. Some cultures have been maintained with active growth for over 6 years. Actively growing cultures in an artificial seawater medium containing organic phosphorus (glycerophosphate) as the principal source of phosphorus have also been established. Key factors that contributed to the successful establishment of cultures were firstly, the seed samples were collected from depth, secondly, samples were thoroughly washed and thirdly, incubations were conducted under relatively low light intensities (PAR similar to 40-50 mumol quanta m(-2) s(-1)). N-2 fixation rates of the cultured Trichodesmium were found to be similar to those measured in the GBRL. Specific growth rates of the cultures during the exponential growth phase in all enriched media were in the range 0.2-0.3 day(-1) and growth during this phase was characterised by individual trichomes (filaments) or small aggregations of two to three trichomes. Characteristic bundle formation tended to occur following the exponential growth phase, which suggests that the bundle formation was induced by a lack of a necessary nutrient e.g. Fe. Results from some exploratory studies showed that filament-dominated cultures of Trichodesmium grew over a range of relatively low irradiances (PAR similar to 5-120 mumol quanta m(-2) s(-1)) with the maximum growth occurring at - 40-50 mumol quanta m(-2) s(-1). These results suggest that filaments of the tested strain are well adapted for growth at depth in marine waters. Other studies showed that growth yields were dependent on salinity, with maximum growth occurring between 30 and 37 psu. Also the cell yields decreased by an order of magnitude with the reduction of Fe additions from 450 to 45 nM. No active growth was observed with the 4.5 nM Fe addition.

Doped ceria (CeO2) compounds are fluorite type oxides which show oxide ionic conductivity higher than yttria stabilized zirconia, in oxidizing atmosphere. As a consequence of this, considerable interest has been shown in application of these materials for ‘low temperature operation (500–650 °C)’ of solid oxide fuel cells (SOFCs). In this study, YxCe1−xO2−δ ( x=0.05, 0.1, 0.15, 0.2 and 0.25) fine powders were prepared using a carbonate co-precipitation method. The relationship between electrolytic properties and nano-structural features in the sintered bodies was examined. The micro-structures of Y0.05Ce0.95O1.975, Y0.15Ce0.85O1.925 and Y0.25Ce0.75O1.875 as representative three specimens have been investigated in more detail with transmission electron microscopy (TEM). The big diffuse scattering was observed in the background of electron diffraction pattern recorded from Y0.15Ce0.85O1.925 and Y0.25Ce0.75O1.875 sintered bodies. This means that the coherent micro-domain with ordered structure is in the micro-structure. While Y0.25Ce0.75O1.875 sintered body with low conductivity and high activation energy has big micro-domains, the micro-domain size in Y0.15Ce0.85O1.925 with high conductivity and low activation energy was much smaller than that of Y0.25Ce0.75O1.875. TEM observation gives us message that the size of coherent micro-domain with ordered structure would closely relate to the electrolytic properties such as conductivity and activation energy in the specimens. It was concluded that a control of micro-domain size in nano-scale in Y2O3 doped CeO2 system was a key for development of high quality solid electrolyte in fuel cell application.

This study aims to compare the relaxivities of ultra-small dual positive and negative contrast iron oxide nanoparticles (DCION) at different magnetic field strengths ranging from 4.7 to 16.4 T at physiological temperatures; and to investigate the effect of particle aggregation on relaxivities. Relaxivities of DCIONs were determined by magnetic resonance imaging scanners at 4.7, 7, 9.4, and 16.4 T. Both longitudinal (T 1) and transverse relaxation times (T 2) were measured by appropriate spin-echo sequences. It has been found that both longitudinal and transverse relaxivities are significantly dependent on the magnetic field strength. Particle aggregation also strongly affects the relaxivities. Awareness of the field strength and particle colloid stability is crucial for the comparison and evaluation of relaxivity values of these ultra-small iron oxide nanoparticles, and also for their medical applications as contrast agents.

The study identifies the various components contributing to atmospheric particulate matter in Brisbane, Queensland, Australia, during the period from the end of April and the months of July–August in 1992, covering the autumn period which is typically the period of high asthma incidence in Brisbane. Most particulate matter is < 2 μm and submicronic. Electron microscopy revealed that the submicron material is composed mainly of combusted (“soot”) and incompletely burned hydrocarbons arising from motor vehicle exhaust emissions, crustal matter in the form of quartz microconcretions and other silicates, quiescent spores of Mucorales, and soil bacteria. The contribution from pollen and fungal spores has been evaluated and quantified. Fungal spores counts dominate the bioaerosol counts in the 2–10 μm range and are very high in Brisbane from the end of April through May to mid-June. However even at peak periods the total bioaerosol count only contributes of the order of 5–10% of the total particulate mass. The results show that Pm10 (particulate matter less than 10 μm in diameter) and nephelometer readings do not indicate peak periods of allergenic bioaerosol readings (in fact there is a negative correlation) due to the low contribution of the bioaerosol count to the total and the different influences of wind speed. However the electron microscopy results show that this does not mean there are no synergies between aerosols from anthropogenic sources and bioaerosols. The cytoplasmic content of spores and pollen was often found to be adhered to motor vehicle emission material and crustal matter. The latter may therefore act as carriers for dispersed cytoplasmic allergenic material released from pollen and fungal spores.

The Clay Minerals Society Source Clay kaolinites, Georgia KGa-1 and KGa-2, have been subjected to particle size determinations by 1) conventional sedimentation methods, 2) electron microscopy and image analysis, and 3) laser scattering using improved algorithms for the interaction of light with small particles. Particle shape, size distribution, and crystallinity vary considerably for each kaolinite. Replicate analyses of separated size fractions showed that in the