A molecular dynamics study of the thermal properties of thorium oxide

There is growing interest in the exploitation of the thorium nuclear fuel cycle as an alternative to that of uranium. As part of a wider study of the suitability of thorium dioxide (thoria) as a nuclear fuel, we have used molecular dynamics to investigate the thermal expansion, oxygen diffusion, and heat capacity of pure thoria and uranium doped (1-10%) thoria between 1500K and 3600 K. Our results indicate that the thermal performance of the thoria matrix, even when doped with 10%U, is comparable to, and possibly better than, that of UO2

Exploring the experiences and outcomes of advantaged and disadvantaged families

This report provides further evidence of the interrelationship between age, young motherhood, family type and a range of measures of socio-economic advantage and disadvantage. Maternal age and family type were found to be closely interrelated and both strongly associated with socio-economic disadvantage, with concentrated disadvantage evident in mothers under 25 and lone parents who do not live with other adults. These measures were also closely associated with health-related behaviours including likelihood of breastfeeding, attending ante-natal classes and smoking amongst mothers. Even amongst more disadvantaged groups, positive health-related behaviours were connected to relative social and economic advantage with level of maternal education featuring prominently

The impact of regulation, ownership and business culture on managing corporate risk within the water industry

Although the specifics of water utility ownership, regulation and management culture have been explored in terms of their impact on economic and customer value, there has been little meaningful engagement with their influence on the risk environment and risk management. Using a literature review as the primary source of information, this paper maps the existing knowledge base onto two critical questions: what are the particular features of regulation, ownership and management culture which influence the risk dynamic, and what are the implications of these relationships in the context of ambitions for resilient organizations? In addressing these queries, the paper considers the mindful choices and adjustments a utility must make to its risk management strategy to manage strategic tensions between efficiency, risk and resilience. The conclusions note a gap in understanding of the drivers required for a paradigm shift within the water sector from a re-active to a pro-active risk management culture. A proposed model of the tensions between reactive risk management and pro-active, adaptive risk management provides a compelling case for measured risk management approaches which are informed by an appreciation of regulation, ownership and business culture. Such approaches will support water authorities in meeting corporate aspirations to become "high reliability" services while retaining the capacity to out-perform financial and service level targets

Insulator–metal transitions in Pr0.7Ca0.3MnO3 induced by a magnetic field

A magnetic field induced insulator to metal transition has been observed in both polycrystalline and single crystals samples of Pr0.7Ca0.3MnO3. Application of a magnetic field leads to a first-order phase transition from an insulating to a conducting state at low temperatures. The hysteresis associated with this transition allows the resistivity at 4 K to be varied by more than eight orders of magnitude depending on the field history of the sample

Remotely triggered scaffolds for controlled release of pharmaceuticals

Fe3O4-Au hybrid nanoparticles (HNPs) have shown increasing potential for biomedical applications such as image guided stimuli responsive drug delivery. Incorporation of the unique properties of HNPs into thermally responsive scaffolds holds great potential for future biomedical applications. Here we successfully fabricated smart scaffolds based on thermo-responsive poly(N-isopropylacrylamide) (pNiPAM). Nanoparticles providing localized trigger of heating when irradiated with a short laser burst were found to give rise to remote control of bulk polymer shrinkage. Gold-coated iron oxide nanoparticles were synthesized using wet chemical precipitation methods followed by electrochemical coating. After subsequent functionalization of particles with allyl methyl sulfide, mercaptodecane, cysteamine and poly(ethylene glycol) thiol to enhance stability, detailed biological safety was determined using live/dead staining and cell membrane integrity studies through lactate dehydrogenase (LDH) quantification. The PEG coated HNPs did not show significant cytotoxic effect or adverse cellular response on exposure to 7F2 cells (p < 0.05) and were carried forward for scaffold incorporation. The pNiPAM-HNP composite scaffolds were investigated for their potential as thermally triggered systems using a Q-switched Nd:YAG laser. These studies show that incorporation of HNPs resulted in scaffold deformation after very short irradiation times (seconds) due to internal structural heating. Our data highlights the potential of these hybrid-scaffold constructs for exploitation in drug delivery, using methylene blue as a model drug being released during remote structural change of the scaffold