Tools to Improve the Production of Emergency Plans for Floods: Are They Being Used by the People that Need Them?

Recently emergency plans for floods have started to be developed in England and France. At present, tools, such as checklists, guidance and specialized software appear to be used rarely to improve the effectiveness of these plans. Research was undertaken with flood managers in the two countries. The objective was to establish why tools that can usefully contribute to improving emergency plans for floods are often not being used. Many flood managers are not aware of the tools that are available to assist them in formulating emergency plans for floods. It was concluded that there is a need for guidance on the tools and how they can be used to help to improve emergency planning for floods.     

On Diverse Approaches to Bipolar Division Operators

Introducing preferences inside user queries has gained more and more acceptance during the past decade. Besides, it turns out that the concept of bipolarity is of interest for expressing queries in the sense that some requirements are mandatory and play the role of constraints, whereas other are solely desirable. In this paper, we investigate how bipolarity may impact the division operator in the context of relational databases. Various forms of bipolar divisions can indeed be devised, each of them conveying a specific semantics. © 2011 Wiley Periodicals, Inc.     

In-situ growth of CdS quantum dots on g-C3N4 nanosheets for highly efficient photocatalytic hydrogen generation under visible light irradiation

Well dispersed CdS quantum dots were successfully grown in-situ on g-C₃N₄ nanosheets through a solvothermal method involving dimethyl sulfoxide. The resultant CdS–C₃N₄ nanocomposites exhibit remarkably higher efficiency for photocatalytic hydrogen evolution under visible light irradiation as compared to pure g-C₃N₄. The optimal composite with 12 wt% CdS showed a hydrogen evolution rate of 4.494 mmol h⁻¹ g⁻¹, which is more than 115 times higher than that of pure g-C₃N₄. The enhanced photocatalytic activity induced by the in-situ grown CdS quantum dots is attributed to the interfacial transfer of photogenerated electrons and holes between g-C₃N₄ and CdS, which leads to effective charge separation on both parts.     

Supercritical Antisolvent Versus Coevaporation— Preparation and Characterization of Solid Dispersions

The objective of this work was to improve the dissolution rate and aqueous solubility of oxeglitazar. Solid dispersions of oxeglitazar in PVP K17 (polyvinilpyrrolidone) and poloxamer 407 (polyoxyethylene-polyoxypropylene block copolymer) were prepared by supercritical antisolvent (SAS) and coevaporation (CoE) methods. Drug-carrier formulations were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, scanning electron microscopy, gas chromatography, UV/VIS spectroscopy and in vitro dissolution tests. The highest dissolution rate (nearly 3-fold higher than raw drug) was achieved by preparation of drug/PVP K17 coevaporate. Oxeglitazar/PVP K17 solid dispersions were stabilized by hydrogen bonding but contained higher amount of residual dichloromethane (DCM) than poloxamer 407 formulations regardless of the method of preparation. SAS prepared oxeglitazar/poloxamer 407 dissolved more than two times faster than raw drug. However, unlike PVP K17, poloxamer 407 did not form a single phase amorphous solid solution with oxeglitazar which has been manifested in higher degrees of crystallinity, too. Among the two techniques, evaluated in this work, conventional coevaporation resulted in higher amorphous content but SAS reduced residual solvent content more efficiently.     

Activity of PtSnRh/C nanoparticles for the electrooxidation of C1 and C2 alcohols

A systematic investigation of alcohol adsorption and oxidation on binary and ternary electrocatalysts in acid medium was performed. Binary (PtRh) and ternary (PtRhSn) were prepared by the Pechini modified method on carbon Vulcan XC-72, and different nominal compositions were characterized by energy dispersive X-ray and X-ray diffraction (XRD) techniques. The XRD results showed that the Pt₈₀Rh₂₀/C and Pt₇₀Sn₁₀Rh₂₀/C electrocatalysts consisted of the Pt displaced phase, suggesting the formation of a solid solution between the metals Pt/Rh and Pt/Sn.Electrochemical investigations on these different electrode materials were carried out as a function of the electrocatalyst composition, in acid medium (0.5 mol dm^− 3 H₂SO₄), and in the absence and presence of different alcohols (methanol, ethanol and ethylene glycol). The electrochemical results obtained at room temperature have shown that the Pt₇₀Sn₁₀Rh₂₀/C catalyst display better catalytic activity for alcohol oxidation compared with the binary catalyst.In situ reflectance infrared spectroscopy measurements have shown that the oxidation of alcohols mentioned produced CO₂ at low potentials indicating that the materials synthesized could be used as efficient anodes in the fuel cell applications.     

Preparation of Au-BiVO4 heterogeneous nanostructures as highly efficient visible-light photocatalysts

Au-BiVO(4) heterogeneous nanostructures have been successfully prepared through in situ growth of gold nanoparticles on BiVO(4) microtubes and nanosheets via a cysteine-linking strategy. The experimental results reveal that these Au-BiVO(4) heterogeneous nanostructures exhibit much higher visible-light photocatalytic activities than the individual BiVO(4) microtubes and nanosheets for both dye degradation and water oxidation. The enhanced photocatalytic efficiencies are attributed to the charge transfer from BiVO(4) to the attached gold nanoparticles as well as their surface plasmon resonance (SPR) absorption. These new heteronanostructures are expected to show considerable potential applications in solar-driven wastewater treatment and water splitting.