Ti₂O₃ film electrode for water treatment via electrochemical chlorine evolution

This work introduces a low-cost and earth-abundant Ti2O3 thin film electrode as the anode for chlorine-driven electrochemical water treatment. A simple method of immobilizing Ti2O3 powder onto a conductive glass substrate has been developed and studied. Electrochemical characterization showed that the chlorine evolution reaction (CER) was more favorable than the oxygen evolution reaction (OER) for the Ti2O3 film electrode. The Ti2O3 film electrode showed high efficiency of free chlorine production, which leads to a good performance in degrading methyl orange (97.9% in 1.5 h) and tetracycline (78.0% in 1.5 h) via chlorine evolution. Pollutant degradation reaction by chlorine is observed to be the major reaction (75%) in this electrochemical water treatment system, while direct electron transfer (DET) reaction also contributed to pollutant degradation. Ti2O3 film electrodes can work efficiently for several cycles with the help of an easy regeneration step between cycles.</p

Increased permeability of the malaria-infected erythrocyte to organic cations

AbstractThe human malaria parasite, Plasmodium falciparum, induces in the plasma membrane of its host red blood cell new permeation pathways (NPP) that allow the influx of a variety of low molecular weight solutes. In this study we have demonstrated that the NPP confer upon the parasitised erythrocyte a substantial permeability to a range of monovalent organic (quaternary ammonium) cations, the largest having an estimated minimum cross-sectional diameter of 11–12 Å. The rate of permeation of these cations showed a marked dependence on the nature of the anion present, increasing with the lyotropicity of the anion. There was no clear relationship between the permeation rate and either the size or the hydrophobicity of these solutes. However, the data were consistent with the rate of permeation being influenced by a combination of these two factors, with the pathways showing a marked preference for the relatively small and hydrophobic phenyltrimethylammonium ion over larger or less hydrophobic solutes. Large quaternary ammonium cations inhibited flux via the NPP, as did long-chain n-alkanols. For both classes of compound the inhibitory potency increased with the size and hydrophobicity of the solute. This study extends the range of solutes known to permeate the NPP of malaria-infected erythrocytes as well as providing some insight into the factors governing the rate of permeation

Connected Women: How Mobile Can Support Women's Economic and Social Empowerment

This report explores how mobile services provided by Vodafone and the Vodafone Foundation are enabling women to seize new opportunities and improve their lives. Accenture Sustainability Services were commissioned to conduct research on the services and to assess their potential social and economic impact if they were widely available across Vodafone's markets by 2020. It showcases the projects and the work of those involved and also poses the question -- what would the benefit to women and to society at large be if projects such as these were taken to scale and achieved an industrialscale of growth? This reflects the Foundation's commitment not solely to the development of pilots but rather the Trustees' ambition to see projects which lead to transformational change. In order to understand this more deeply, the Report looks at the benefits for women and society and providessome financial modelling for how the engagement of commercial players could achieve industrial, sustainable growth in these areas. Accenture has provided the modelling and, given the public benefit and understanding which the report seeks to generate, these are shared openly for all in the mobile industry to understand and share. It is the Trustees' hope that the collaboration with Oxford University and Accenture in the delivery of this Report will stimulate not only the expansion of existing charitable programmes but will also seed other philanthropic, social enterprise or commercial initiatives

Investigating the hydration of C3A in the presence of the potentially toxic element chromium–a route to remediation?

Pollution by hexavalent chromium is a growing, global problem. Its presence in public water systems is often the result of industrial activities, both past and present. In this study, tricalcium aluminate (C3A, Ca(3)Al(2)O(6)) is added to solutions of varying concentrations of potassium chromate (K(2)CrO(4)) and samples of both the solid and liquid are taken at various time intervals to monitor the removal of chromium from the solutions. Solution concentrations of 0.2 M, 0.1 M, 0.02 M, and 0.01 M are used, and the chromium concentration is found to reduce in all cases. For the 0.02 M solution the chromium concentration is reduced from 1040 ppm to 3.1 ppm in 1 week, and the chromium concentration of the 0.01 M solution is reduced from 520 ppm to 0.26 ppm in only one day of reaction with the C3A. The chromium removed from solution is identified in the solid products, which were fully characterised as being a mixture of ettringite (Ca(6)[Al(OH)(6)](2)(CrO(4))(3)·26H(2)O) and monochromate (Ca(4)[Al(OH)(6)](2)CrO(4)·8H(2)O) phases from analysis of Powder X-ray Diffraction and Fourier Transform Infrared Spectroscopy data. The work presented here is a proof of concept study to investigate C3A as a potential material for the removal of hexavalent chromium from solution. The results from this study are initial steps towards development of this as a technology for hexavalent chromium remediation

Synchrotron X-ray and neutron investigation of the structure and thermal expansion of the monoclinic Al13Cr2 phase

The crystal structure of the Al13Cr2 intermetallic phase at 298 K was studied by synchrotron X-ray and neutron diffraction through the analysis of data collected on bulk samples, one in the as-cast condition, one after annealing at 773 K for 24 h and one for 168 h. Furthermore the thermal expansion behaviour of the structure was investigated for the first time in-situ up to 773 K. The diffraction patterns were analysed using whole pattern fitting techniques using the Le Bail and Pawley methods as well as the Rietveld method. The structure was found to be monoclinic with space group C2=m and lattice parameters a ¼ 25.3101 Å, b ¼ 7.6081 Å, c ¼ 10.9689 Å and b ¼ 128.704+ at 298 K in the as-cast condition. From the temperature variation of the unit cell parameters the principal axes of the thermal expansion tensor were calculated. The largest principal axis has a magnitude of 1:66 105 K1 and lies parallel to b, the second largest lies in the a-c plane at an angle of ∼37° from c in the direction of -a with a value 1:64 105 K1 whereas the smallest lies at ∼53° to c in the direction of þa and has a value of 1:31 105 K1 . Analysis of the behaviour of the icosahedra revealed that their expansion is highly anisotropic and the level of anisotropy is related to the point symmetry of the central Cr atoms

α/β-Ni(OH)₂ phase control by F-ion incorporation to optimise hybrid supercapacitor performance

We have controlled the formation of flower-like nanostructured pure alpha phase and pure beta phase nickel hydroxide (α-Ni(OH)2, β-Ni(OH)2), as well as mixtures of phases (αβ-Ni(OH)2). Through a range of experiments, we prove that the addition of fluoride ions controls the phase formed and we suggest two possible mechanisms for this effect. Incorporated fluoride ions in the layers disfavour the insertion of other anions and water molecules, resulting in β-Ni(OH)2 which has a smaller interlayer distance; and we suggest that the high electronegativity of F results in less nickel oxidation to Ni3+ also disfavouring extra anions between layers. The nickel hydroxide materials were characterised by a suite of techniques including powder X-ray diffraction, electron microscopy, thermal analysis and in situ X-ray absorption spectroscopy, in combination with electrochemical studies. The redox cycle stability and conductivity were improved through control of phase formation, such that αβ-Ni(OH)2 exhibits 108% capacity retention after 2000 continuous charge-discharge cycles at 20 mA cm−1 while α-Ni(OH)2 displays only 50% capacity retention after 2000 cycles. Finally, the assembled αβ-Ni(OH)2//activated carbon hybrid supercapacitor displays maximum energy density of 32 W h kg−1 at a power density of 900 W kg−1, and retains 86% capacity after 5000 continuous charge-discharge cycles.</p