Structure–property insights into nanostructured electrodes for Li-ion batteries from local structural and diffusional probes

Microwave heating presents a faster, lower energy synthetic methodology for the realization of functional materials. Here, we demonstrate for the first time that employing this method also leads to a decrease in the occurrence of defects in olivine structured LiFe1−xMnxPO4. For example, the presence of antisite defects in this structure precludes Li+ diffusion along the b-axis leading to a significant decrease in reversible capacities. Total scattering measurements, in combination with Li+ diffusion studies using muon spin relaxation (μ+SR) spectroscopy, reveal that this synthetic method generates fewer defects in the nanostructures compared to traditional solvothermal routes. Our interest in developing these routes to mixed-metal phosphate LiFe1−xMnxPO4 olivines is due to the higher Mn2+/3+ redox potential in comparison to the Fe2+/3+ pair. Here, single-phase LiFe1−xMnxPO4 (x = 0, 0.25, 0.5, 0.75 and 1) olivines have been prepared following a microwave-assisted approach which allows for up to 4 times faster reaction times compared to traditional solvothermal methods. Interestingly, the resulting particle morphology is dependent on the Mn content. We also examine their electrochemical performance as active electrodes in Li-ion batteries. These results present microwave routes as highly attractive for reproducible, gram-scale syntheses of high quality nanostructured electrodes which display close to theoretical capacity for the full iron phase

A Collaborative Children\u27s Literature Book Club for Teacher Candidates

This paper highlights the two-year journey of an extra-curricular book club for teacher candidates as they explored children’s literature in order to further their teaching practice. Initial themes were confirmed and refined as the journey of the book club concluded after two years. A sociocultural theoretical framework guided this work and considered Cambourne’s (1988) conditions of learning, specifically immersion in texts, as well as the important role of social contexts in developing shared text meanings. A qualitative methodology, drawing on participatory action research (Kemmis & McTaggart, 2005) and taking a case study approach to sharing the case of this collaborative children’s literature book club, was used

M.C.R.G. Study of Fixed-connectivity Surfaces

We apply Monte Carlo Renormalization group to the crumpling transition in random surface models of fixed connectivity. This transition is notoriously difficult to treat numerically. We employ here a Fourier accelerated Langevin algorithm in conjunction with a novel blocking procedure in momentum space which has proven extremely successful in $\lambda\phi^4$. We perform two successive renormalizations in lattices with up to $64^2$ sites. We obtain a result for the critical exponent $\nu$ in general agreement with previous estimates and similar error bars, but with much less computational effort. We also measure with great accuracy $\eta$. As a by-product we are able to determine the fractal dimension $d_H$ of random surfaces at the crumpling transition.Comment: 35 pages,Latex file, 6 Postscript figures uuencoded,uses psfig.sty 2 misspelled references corrected and one added. Paper unchange

Evaluation of Nanomaterial Approaches to Damping in Epoxy Resin and Carbon Fiber/Epoxy Composite Structures by Dynamic Mechanical Analysis

Vibration mitigation in composite structures has been demonstrated through widely varying methods which include both active and passive damping. Recently, nanomaterials have been investigated as a viable approach to composite vibration damping due to the large surface available to generate energy dissipation through friction. This work evaluates the influence of dispersed nanoparticles on the damping ratio of an epoxy matrix. Limited benefit was observed through dispersion methods, however nanoparticle application as a coating resulting in up to a three-fold increase in damping

Seabed Mining and Approaches to Governance of the Deep Seabed

Commercial seabed mining seems imminent, highlighting the urgent need for coherent, effective policy to safeguard the marine environment. Reconciling seabed mining with the United Nations Sustainable Development Goals will be difficult because minerals extraction will have irreversible consequences that could lead to the loss of habitats, species and ecosystems services. A dialog needs to take place around social, cultural, environmental and economic costs and benefits. Governance of human interactions with the seabed is fragmented and lacks transparency, with a heavy focus on facilitating exploitation rather than ensuring protection. In the light of high uncertainties and high stakes, we present a critical review of proposed policy options for the regulation of seabed mining activities, recommend actions to improve seabed governance and outline the alternatives to mining fragile deep-sea ecosystems

Dynamical Casimir Effect with Semi-Transparent Mirrors, and Cosmology

After reviewing some essential features of the Casimir effect and, specifically, of its regularization by zeta function and Hadamard methods, we consider the dynamical Casimir effect (or Fulling-Davis theory), where related regularization problems appear, with a view to an experimental verification of this theory. We finish with a discussion of the possible contribution of vacuum fluctuations to dark energy, in a Casimir like fashion, that might involve the dynamical version.Comment: 11 pages, Talk given in the Workshop ``Quantum Field Theory under the Influence of External Conditions (QFEXT07)'', Leipzig (Germany), September 17 - 21, 200