Analysis and comparison of three Coleoptera families in organic and conventional orchards within the Etna Regional Park (Catania, Sicily)

The objective of this work was to compare two agricultural management systems, organic and conventional, in the Etna Regional Park. The influence in both spatial and temporal dimensions, that natural habitats adjacent to these two different managed agricultural systems have on Coleoptera biocoenosis in orchards was also studied. This comparison was done through standardised data and multivariate analysis using a multi-taxa approach. Specifically, three families of the Order Coleoptera, namely Carabidae, Tenebrionidae and Staphylinidae (excluding Aleocharinae and Scydmaeninae) were studied.peer-reviewe

Superior Water Sheeting Effect on Photocatalytic Titania Nanowire Coated Glass

Simple, rapid, and inexpensive fabrication of self-cleaning glass surfaces based on wet chemical deposition of H₂Ti₃O₇ (trititanate) and subsequent transformation of it into TiO₂ (anatase) nanowires on pristine glass surfaces is reported. Despite the low, 55%, surface coverage, the nanowire roughened glass surface showed self-cleaning properties comparable to much thicker, over 100-nm-thick, TiO₂ nanoparticle coated glasses. The superwettable surface showed 12° contact angle. Moreover, ultraviolet (UV) and natural light activated photocatalysis remained effective at enhancing the self-cleaning process in the case of the TiO₂ nanowire coated glass. Time-resolved study of the water droplet spread in millisecond time scales revealed that capillary forces induced by the random nanowire network significantly enhance the water sheeting effect of these textured glass surfaces. Time-resolved experiments revealed that the spreading velocity of the droplets were enhanced by 19% for the TiO₂ nanowire roughened surface and reached a <i>v</i>₀ = 508 mm/s initial spreading speed. Outdoor experiments validated the concept that TiO₂ nanowire coated glass possess self-cleaning properties with significantly reduced titania content compared to nanoparticle based films

Superior Water Sheeting Effect on Photocatalytic Titania Nanowire Coated Glass

Simple, rapid, and inexpensive fabrication of self-cleaning glass surfaces based on wet chemical deposition of H₂Ti₃O₇ (trititanate) and subsequent transformation of it into TiO₂ (anatase) nanowires on pristine glass surfaces is reported. Despite the low, 55%, surface coverage, the nanowire roughened glass surface showed self-cleaning properties comparable to much thicker, over 100-nm-thick, TiO₂ nanoparticle coated glasses. The superwettable surface showed 12° contact angle. Moreover, ultraviolet (UV) and natural light activated photocatalysis remained effective at enhancing the self-cleaning process in the case of the TiO₂ nanowire coated glass. Time-resolved study of the water droplet spread in millisecond time scales revealed that capillary forces induced by the random nanowire network significantly enhance the water sheeting effect of these textured glass surfaces. Time-resolved experiments revealed that the spreading velocity of the droplets were enhanced by 19% for the TiO₂ nanowire roughened surface and reached a <i>v</i>₀ = 508 mm/s initial spreading speed. Outdoor experiments validated the concept that TiO₂ nanowire coated glass possess self-cleaning properties with significantly reduced titania content compared to nanoparticle based films

Photodiode Response in a CH₃NH₃PbI₃/CH₃NH₃SnI₃ Heterojunction

Here we report another surprising feature of the methylammonium metal halide material family, the phototunability of the diode response of a heterojunction made of CH₃NH₃PbI₃ and its close relative, CH₃NH₃SnI₃. In the dark state the device behaves as a diode, with the Sn homologue acting as the “<i>p</i>” side. The junction is extremely sensitive to illumination. A complete reversal of the diode polarity, the first observation of its kind, is seen when the junction is exposed to red laser light of 25 mW/cm² or larger power density. This finding opens up the possibility for a novel class of optoelectronic devices

Influence of Protamine Functionalization on the Colloidal Stability of 1D and 2D Titanium Oxide Nanostructures

The colloidal stability of titanium oxide nanosheets (TNS) and nanowires (TiONW) was studied in the presence of protamine (natural polyelectrolyte) in aqueous dispersions, where the nanostructures possessed negative net charge, and the protamine was positively charged. Regardless of their shape, similar charging and aggregation behaviors were observed for both TNS and TiONW. Electrophoretic experiments performed at different protamine loadings revealed that the adsorption of protamine led to charge neutralization and charge inversion depending on the polyelectrolyte dose applied. Light scattering measurements indicated unstable dispersions once the surface charge was close to zero or slow aggregation below and above the charge neutralization point with negatively or positively charged nanostructures, respectively. These stability regimes were confirmed by the electron microscopy images taken at different polyelectrolyte loadings. The protamine dose and salt-dependent colloidal stability confirmed the presence of DLVO-type interparticle forces, and no experimental evidence was found for additional interactions (e.g., patch-charge, hydrophobic, or steric forces), which are usually present in similar polyelectrolyte–particle systems. These findings indicate that the polyelectrolyte adsorbs on the TNS and TiONW surfaces in a flat and extended conformation giving rise to the absence of surface heterogeneities. Therefore, protamine is an excellent biocompatible candidate to form smooth surfaces, for instance in multilayers composed of polyelectrolytes and particles to be used in biomedical applications

Nanopore Integrated Nanogaps for DNA Detection

A high-throughput fabrication of sub-10 nm nanogap electrodes combined with solid-state nanopores is described. These devices should allow concomitant tunneling and ionic current detection of translocating DNA molecules. We report the optimal fabrication parameters in terms of dose, resist thickness, and gap shape that allow easy reproduction of the fabrication process at wafer scale. The device noise and current voltage characterizations performed and the influence of the nanoelectrodes on the ionic current noise is identified. In some cases, ionic current rectification for connected or biased nanogap electrodes is also observed. In order to increase the extremely low translocation rates, several experimental strategies were tested and modeled using finite element analysis. Our findings are useful for future device designs of nanopore integrated electrodes for DNA sequencing

Nanowires of Methylammonium Lead Iodide (CH₃NH₃PbI₃) Prepared by Low Temperature Solution-Mediated Crystallization

We report the synthesis of Methylammonium Lead Iodide (CH₃NH₃PbI₃) nanowires by a low temperature solution processed crystallization using a simple slip-coating method. The anisotropic particle shape exhibits advantages over nanoparticles in terms of charge transport under illumination. These results provide a basis for solvent-mediated tailoring of structural properties like the crystallite size and orientation in trihalide perovskite thin films, which, once implemented into a device, may ultimately result in an enhanced charge carrier extraction

Three-Dimensionally Enlarged Photoelectrodes by a Protogenetic Inclusion of Vertically Aligned Carbon Nanotubes into CH₃NH₃PbBr₃ Single Crystals

We demonstrate that single crystals of methylammonium lead bromide (MAPbBr₃) could be grown directly on vertically aligned carbon nanotube (VACNT) forests. The fast-growing MAPbBr₃ single crystals engulfed the protogenetic inclusions in the form of individual CNTs, thus resulting in a three-dimensionally enlarged photosensitive interface. Photodetector devices were obtained, detecting low light intensities (∼20 nW) from the UV range to 550 nm. Moreover, a photocurrent was recorded at zero external bias voltage, which points to the plausible formation of a p–n junction resulting from interpenetration of MAPbBr₃ single crystals into the VACNT forest. This reveals that vertically aligned CNTs can be used as electrodes in operationally stable perovskite-based optoelectronic devices and can serve as a versatile platform for future selective electrode development

The Role of Transport Agents in MoS₂ Single Crystals

We report resistivity, thermoelectric power, and thermal conductivity of MoS₂ single crystals prepared by the chemical vapor transport (CVT) method using I₂, Br₂, and TeCl₄ as transport agents. The material presents low-lying donor and acceptor levels, which dominate the in-plane charge transport. Intercalates into the van der Waals gap strongly influence the interplane resistivity. Thermoelectric power displays the characteristics of strong electron–phonon interaction. A detailed theoretical model of thermal conductivity reveals the presence of a high number of defects in the MoS₂ structure. We show that these defects are inherent to CVT growth method, coming mostly from the transport agent molecules inclusion as identified by total reflection X-ray fluorescence analysis (TXRF) and in-beam activation analysis (IBAA)