TUNABLE FEATURES OF TIO2 NANOPARTICLES FOR PHOTOCATALYTIC AND PHOTOVOLTAIC APPLICATIONS: A FUNDAMENTAL STUDY OF ELECTRONIC AND STRUCTURAL ASPECTS.

Nanosized titanium dioxide has been widely explored as both pristine and doped semiconductor. TiO2 nanocrystals were successfully synthesized by three different procedures. Two of them are based on a controlled sol\u2013gel reaction, implemented either by doping or by a hydrothermal growth step with the use of surfactants, exploiting three-dimensional micelles. The latter one is a microemulsion-mediate route, to accurately control the growth of Ti precursor in nanoreactors by the con\ufb01nement in aqueous droplets. As for the doping, both metal and non-metal elements have been chosen, namely praseodymium, silver and nitrogen. In this latter case, both organic and inorganic sources, in turn, were used to modulate the N content of doped-titania. All samples were characterized from the morphological, structural, optical, and electronic points of view. Moreover, for selected N-TiO2 samples, the role of the aging time after the calcinations of the powders (from \u201cfreshly prepared\u201d to \u201cold\u201d samples) both on the intensity of the optical features and on the bulk paramagnetic nitrogen concentration was also considered. Two main fields of applications for titania powders and films were investigated: photocatalysis and photovoltaics. Thus, the photocatalytic activity of several samples was tested using either UV or visible light irradiation with regard to different pollutants, ranging from ethanol (both in aqueous and gaseous media) to the more complex methylene blue molecule (deposited onto the oxide film). Besides, advanced oxidation processes were successfully applied to the degradation and final mineralization of bisphenol A and 4-cumylphenol. The use of TiO2 immobilized in thin films is of paramount importance for the plant-scale applicability of the process, especially if a low intensity irradiation source, such as solar light, is to be exploited. Then, photocatalytic reduction of hexavalent chromium was conducted with the use of electrodeposited TiO2 layers. Even though (doped) titanium dioxide is one of the most commonly adopted semiconductors in photocatalysis, it suffers from a relatively high bandgap \u2013 hence the doping to increase visible light absorption \u2013 and from recombination of photogenerated charge carriers. Furthermore, univocal conclusions on the Fermi energy levels, chemical nature and location of the doping centers, and related charge transfer processes versus dopant concentration are absent in the literature. Therefore, electronic effects induced by the presence of the heteroatom in the TiO2 nanocrystals were investigated by a synergistic combination of electrochemical experiments (Mott-Schottky plots, photovoltage and photocurrent measurements) and theoretical DFT calculations. Results on the doped materials point towards a reduced tendency to charge carriers\u2019 recombination and different effects on the (quasi-)Fermi energy location of the final material. Recombination is a central issue also in solar cell devices, resulting in possible low efficiencies. The ability of spin-coated and spray-pyrolyzed TiO2 blocking layers in preventing or reducing losses arising from electron transfer via the transparent conductive substrate has been examined in bilayer hybrid dye-sensitized solar cell (DSC) devices. Then, different types of both solid-state dye-sensitized solar cells and DSCs with a liquid electrolyte were tested making use of the more effective spray-pyrolyzed TiO2 as \u201cblocking layer\u201d and optimizing home-made nanostructured titania pastes

Addition of magnesium sulphate to ropivacaine for spinal analgesia in dogs undergoing tibial plateau levelling osteotomy

The aim of this blinded, randomised, prospective clinical trial was to determine whether the addition of magnesium sulphate to spinally-administered ropivacaine would improve peri-operative analgesia without impairing motor function in dogs undergoing orthopaedic surgery. Twenty client-owned dogs undergoing tibial plateau levelling osteotomy were randomly assigned to one of two treatment groups: group C (control, receiving hyperbaric ropivacaine by the spinal route) or group M (magnesium, receiving a hyperbaric combination of magnesium sulphate and ropivacaine by the spinal route). During surgery, changes in physiological variables above baseline were used to evaluate nociception. Arterial blood was collected before and after spinal injection, at four time points, to monitor plasma magnesium concentrations. Post-operatively, pain was assessed with a modified Sammarco pain score, a Glasgow pain scale and a visual analogue scale, while motor function was evaluated with a modified Tarlov scale. Assessments were performed at recovery and 1, 2 and 3 h thereafter. Fentanyl and buprenorphine were administered as rescue analgesics in the intra- and post-operative periods, respectively. Plasma magnesium concentrations did not increase after spinal injection compared to baseline. Group M required less intra-operative fentanyl, had lower Glasgow pain scores and experienced analgesia of longer duration than group C (527.0 ± 341.0 min vs. 176.0 ± 109.0 min). However, in group M the motor block was significantly longer, which limits the usefulness of magnesium for spinal analgesia at the investigated dose. Further research is needed to determine a clinically effective dose with shorter duration of motor block for magnesium used as an additive to spinal analgesic agents

Mesoporous Titania Nanocrystals by Hydrothermal Template Growth

Mesoporous TiO(2) nanocrystals have been synthetized by a classical sol-gel route integrated by an hydrothermal growth step using monomeric (dodecylpyridinium chloride, DPC) or dimeric gemini-like (GS3) surfactants as template directing agents. Adsorption isotherms at the solid/liquid interface of the two surfactants have been obtained on aqueous dispersion of titania; the nature of the oxide/adsorbate interactions and the molecules orientation/coarea are discussed. The effects produced by the presence of the two surfactants on the different morphological (surface area, porosity, and shape) and structural (phase composition and aggregate size) features of the final TiO(2) samples, calcined at 600 degrees C, are discussed

Hazardous o-toluidine mineralization by photocatalytic bismuth doped ZnO slurries

Photocatalytic mineralization of o-toluidine in aqueous media under UV/solar irradiation was achieved by bare and bismuth doped zinc oxide nanoparticles. By adopting different analytical approaches a reaction mechanism is proposed, explaining the differences in photodetoxification performances

A geo-chemo-mechanical study of a highly polluted marine system (Taranto, Italy) for the enhancement of the conceptual site model

The paper presents the results of the analysis of the geo-chemo-mechanical data gathered through an innovative multidisciplinary investigation campaign in the Mar Piccolo basin, a heavily polluted marine bay aside the town of Taranto (Southern Italy). The basin is part of an area declared at high environmental risk by the Italian government. The cutting-edge approach to the environmental characterization of the site was promoted by the Special Commissioner for urgent measures of reclamation, environmental improvements and redevelopment of Taranto and involved experts from several research fields, who cooperated to gather a new insight into the origin, distribution, mobility and fate of the contaminants within the basin. The investigation campaign was designed to implement advanced research methodologies and testing strategies. Differently from traditional investigation campaigns, aimed solely at the assessment of the contamination state within sediments lying in the top layers, the new campaign provided an interpretation of the geo-chemo-mechanical properties and state of the sediments forming the deposit at the seafloor. The integrated, multidisciplinary and holistic approach, that considered geotechnical engineering, electrical and electronical engineering, geological, sedimentological, mineralogical, hydraulic engineering, hydrological, chemical, geochemical, biological fields, supported a comprehensive understanding of the influence of the contamination on the hydro-mechanical properties of the sediments, which need to be accounted for in the selection and design of the risk mitigation measures. The findings of the research represent the input ingredients of the conceptual model of the site, premise to model the evolutionary contamination scenarios within the basin, of guidance for the environmental risk management. The study testifies the importance of the cooperative approach among researchers of different fields to fulfil the interpretation of complex polluted eco-systems

MAGGnet: an international network to foster mitigation of agricultural greenhouse gases.

Research networks provide a framework for review, synthesis and systematic testing of theories by multiple scientists across international borders critical for addressing global-scale issues. In 2012, a GHG research network referred to as MAGGnet (Managing Agricultural Greenhouse Gases Network) was established within the Croplands Research Group of the Global Research Alliance on Agricultural Greenhouse Gases (GRA). With involvement from 46 alliance member countries, MAGGnet seeks to provide a platform for the inventory and analysis of agricultural GHG mitigation research throughout the world. To date, metadata from 315 experimental studies in 20 countries have been compiled using a standardized spreadsheet. Most studies were completed (74%) and conducted within a 1-3-year duration (68%). Soil carbon and nitrous oxide emissions were measured in over 80% of the studies. Among plant variables, grain yield was assessed across studies most frequently (56%), followed by stover (35%) and root (9%) biomass. MAGGnet has contributed to modeling efforts and has spurred other research groups in the GRA to collect experimental site metadata using an adapted spreadsheet. With continued growth and investment, MAGGnet will leverage limited-resource investments by any one country to produce an inclusive, globally shared meta-database focused on the science of GHG mitigation

The banking-industry relationship in Italy: large national banks and small local banks compared (1913-1936)

Using a large dataset of Italian joint-stock companies, this article analyses the networks of corporate interlocks of the major universal banks and twenty most ‘central’ local banks in a critical period of Italian industrialisation. The networks of the two types of banks were largely independent, with universal banks being affiliated principally to larger concerns in electricity, transport and storage, and financials; and local banks to riskier, younger and smaller firms in light manufacturing. The article then explores whether the bank-industry relationship in Italy reflected the hegemony of banks and followed a bank-control model. Our analysis does not support that view. It rather indicates that interlocking directorates were driven principally by a convergence of interests between banks (monitoring customers) and industrial firms (interested in tapping capital and credit flows), with the latter exerting a slightly higher influence over the former. This significantly differentiates Italy from Germany and the USA, where banks had a more dominant position in the corporate system

Probabilistic downscaling of remote sensing data with applications for multi-scale biogeochemical flux modeling

Upscaling ecological information to larger scales in space and downscaling remote sensing observations or model simulations to finer scales remain grand challenges in Earth system science. Downscaling often involves inferring subgrid information from coarse-scale data, and such ill-posed problems are classically addressed using regularization. Here, we apply two-dimensional Tikhonov Regularization (2DTR) to simulate subgrid surface patterns for ecological applications. Specifically, we test the ability of 2DTR to simulate the spatial statistics of high-resolution (4 m) remote sensing observations of the normalized difference vegetation index (NDVI) in a tundra landscape. We find that the 2DTR approach as applied here can capture the major mode of spatial variability of the high-resolution information, but not multiple modes of spatial variability, and that the Lagrange multiplier (γ) used to impose the condition of smoothness across space is related to the range of the experimental semivariogram. We used observed and 2DTR-simulated maps of NDVI to estimate landscape-level leaf area index (LAI) and gross primary productivity (GPP). NDVI maps simulated using a γ value that approximates the range of observed NDVI result in a landscape-level GPP estimate that differs by ca 2% from those created using observed NDVI. Following findings that GPP per unit LAI is lower near vegetation patch edges, we simulated vegetation patch edges using multiple approaches and found that simulated GPP declined by up to 12% as a result. 2DTR can generate random landscapes rapidly and can be applied to disaggregate ecological information and compare of spatial observations against simulated landscapes