262 research outputs found

    Innovative Soil Management and Micro-Climate Modulation for Saving Water in Peach Orchards

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    Microclimatic and soil management studies emphasize that roofing above the canopy or soil mulching contributes to reduce water losses from horticultural cropping systems and, at the same time, to increase water use efficiency. The aim of this 2-year on-farm study, carried out on a late ripening peach (cv. California) orchard, was to investigate the combined effect of water supply (full or deficit irrigation, DI), incoming light (hail or shading net), and soil management (tilling or mulching) on: microclimate; fruit growth; yield; irrigation water use productivity (WPI); and soil water stress coefficient (Ks). Shading hail net reduced air temperature (−1°C), wind speed (−57%), solar radiation (−32%), while increased relative air humidity (+9.5%). Compared to the control treatment (hail net coverage, soil tillage, and full irrigation), the innovative management (DI + shading hail net + mulching) reduced seasonal volumes of irrigation water (−25%) and increased both final yield (+36%) and WPI (+53%). Saving water resources without losing yield is an achievable goal by peach orchards growing under the Mediterranean climate if the DI agro-technique is adopted conjointly with shading hail net and soil mulching

    Evaluation of infertility

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    The most important goal of fertility investigation is to identify the cause(s) of infertility and to prescribe adequate therapy. The couple should be treated as a single unit as each partner contributes a share to the infertility potential of the couple. Evaluation should begin with the taking of a detailed history and a complete physical examination of both partners, which may point the investigation in a particular direction. However, other pertinent fertility factors should not be overlooked. A standardized and comprehensive approach to the investigation of infertility is proposed and is presented as a series of flow chart

    Evaluation of infertility

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    The most important goal of fertility investigation is to identify the cause(s) of infertility and to prescribe adequate therapy. The couple should be treated as a single unit as each partner contributes a share to the infertility potential of the couple. Evaluation should begin with the taking of a detailed history and a complete physical examination of both partners, which may point the investigation in a particular direction. However, other pertinent fertility factors should not be overlooked. A standardized and comprehensive approach to the investigation of infertility is proposed and is presented as a series of flow chart

    Microemulsion-Based Gels for Lipase-Catalyzed Ester Synthesis in Organic Solvents

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    Microemulsions are clear, stable, isotropic mixtures of oil, water, and surfactant, frequently in combination with a cosurfactant. These systems are currently of interest to the pharmaceutical scientist because of their considerable potential to act as drug delivery vehicles by incorporating a wide range of drug molecules. The purpose of this work is to solubilize in AOT [sodium bis(2-ethylhexyl)sulphosuccinate] water-in-oil microemulsions at two different R-values the Chromobacterium viscosum (CV) lipase and lipoprotein lipase ex Pseudomonas and to use them to catalyze the lactonization of 16-hydroxyhexadecanoic acid at 40°C. CV lipase is also immobilized in gelatin-containing microemulsion-based gels (MBGs) with retention of catalytic activity. These lipase-containing MBGs proved to be novel solid-phase catalysts for use in apolar organic solvents. CV lipase-containing MBGs are used to synthesize, on a preparative scale, a variety of different esters under mild conditions

    Partial Hydrogenation of Soybean and Waste Cooking Oil Biodiesel over Recyclable-Polymer-Supported Pd and Ni Nanoparticles

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    Biodiesel obtained through the transesterification in methanol of vegetable oils, such as soybean oil (SO) and waste cooking oil (WCO), cannot be used as a biofuel for automotive applications due to the presence of polyunsaturated fatty esters, which have a detrimental effect on oxidation stability (OS). A method of upgrading this material is the catalytic partial hydrogenation of the fatty acid methyl ester (FAME) mixture. The target molecule of the partial hydrogenation reaction is monounsaturated methyl oleate (C18:1), which represents a good compromise between OS and the cold filter plugging point (CFPP) value, which becomes too high if the biodiesel consists of unsaturated fatty esters only. In the present work, polymer-supported palladium (Pd-pol) and nickel (Ni-pol) nanoparticles were separately tested as catalysts for upgrading SO and WCO biodiesels under mild conditions (room temperature for Pd-pol and T = 100◦ C for Ni-pol) using dihydrogen (p = 10 bar) as the reductant. Both catalysts were obtained through co-polymerization of the metal containing monomer M(AAEMA)2 (M = Pd, Ni; AEEMA− = deprotonated form of 2-(acetoacetoxy)ethyl methacrylate)) with co-monomers (ethyl methacrylate for Pd and N,N-dimethylacrilamide for Ni) and cross-linkers (ethylene glycol dimethacrylate for Pd and N,N’-methylene bis-acrylamide for Ni), followed by reduction. The Pd-pol system became very active in the hydrogenation of C=C double bonds, but poorly selective towards the desirable C18:1 product. The Ni-pol catalyst was less active than Pd-pol, but very selective towards the mono-unsaturated product. Recyclability tests demonstrated that the Ni-based system retained its activity and selectivity with both the SO and WCO substrates for at least five subsequent runs, thus representing an opportunity for waste biomass valorization

    Synthesis by sol-gel route, chemical and biological characterization of hybrid material composed by Fe(II)C and poly(ε-caprolactone)

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    Abstract. Sol-gel route represents a valuable technique to obtain functional materials, in which organic and inorganic members are closely connected. Imbalance of the iron level in the body causes several diseases. In particular, the low level of iron, during pregnancy, is responsible of the iron deficiency anemia, and even of neurodegenerative diseases. The aim of this work was the synthesis of therapeutic systems, iron (II) based, by sol-gel method. In a SiO2 matrix were embedded polyethylene glycol (PCL 7, wt%) and ferrous citrate (Fe(II)C 6wt%) for drug delivery applications. Fourier Transform Infrared (FTIR) spectroscopy was used to study the interactions among different components in the hybrid materials. SiO2/Fe(II)C/PCL materials have been proposed as valuable antibacterial agents against Escherichia coli and Enterococcus faecalis

    . Microwave-assisted solvothermal controlled synthesis of Fe-Co

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    Syntheses of bimetallic cobalt-iron-based nanoparticles starting from Co(acac)2 and Fe(acac)3 (acac = acetylacetonate) were carried out by microwave-assisted solvothermal process, using ethylene glycol as the solvent and (polyvinylpyrrolidone) PVP, as the stabilizer. Indeed, the reaction mechanism in the presence of ethylene glycol is well understood [1] with the role of PVP being the inhibition of nanoparticles growth [2]. However, the control of the morphology of the synthetized nanoparticles is still a great challenge. Herein, we demonstrated that by adding amines to the reaction mixture, it is possible to control the morphology of the prepared bimetallic cobalt-iron materials. Thus, different Co-Fe micro-composites were synthetized by an innovative microwave assisted solvothermal synthesis, which allows to considerably reduce reaction time from 12 h to 15 min, with respect to classical thermal methods. The procedure was optimized by varying several parameters, such as: amount of PVP, in the presence or in the absence of amines, reaction temperature. The dark brown obtained powders were characterized by scanning electron microscopy, infrared spectroscopy and thermogravimetric analysis, confirming the beneficial effect of the presence of the amine in the morphology of the obtained composites. The obtained results open a new scenario for further studies on the possibility to control the morphology of bimetallic composite materials. [1] Fievet F, Lagier J P and Figlarz M Mater. Res. Soc. Bull. 24 (1989) 29–34 [2] Teranishi T, Kurita R and Miyake M J. Inorg. Organometall. Polym. 10 (2000) 145–5

    Polyacetylenes Bearing Chiral-Substituted Fluorene and Terfluorene Pendant Groups: Synthesis and Properties

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    The synthesis of the first polyacetylenes bearing chiral fluorene-based pendant groups is described. Poly{9,9-bis[(S)-3,7-dimethyloctyl]fluoren-2-ylacetylene} (PFA1), poly{9,9-bis[(S)-2-methylbutyl]- fluoren-2-ylacetylene} (PFA2), and poly{9,9,9′,9′,9′′,9′′-hexakis[(S)-2-methylbutyl]-7,2′;7′,2′′-terfluoren- 2-ylacetylene} (PFA3) have been obtained by Rh(I)-catalyzed polymerization of the corresponding terminal acetylene monomers 2-ethynyl-9,9-bis[(S)-3,7-dimethyloctyl]fluorene (2a), 2-ethynyl-9,9-bis[(S)-2-methylbutyl]fluorene (2b), and 2-ethynyl-9,9,9′,9′,9′′,9′′-hexakis[(S)-2-methylbutyl]-7,2′;7′,2′′-terfluorene (10). The effect of the alkyl chain length at the C-9 position of fluorene on the structural and conformational aspects of the polymers PFA1 and PFA2 as well as on their chiroptical properties was studied by XRD, DSC, TGA, GPC, UV-vis, and CD. A more planar conformation of the polyenic backbone of PFA1 with respect to PFA2 can be inferred by a red shift of the ð-ð* transition in the UV-vis spectra. Their photoluminescence properties are those typical of fluorene systems. CD measurements evidenced Cotton effects of opposite signs in correspondence of the backbone absorption region, ascribable to an excess of a screw sense of the helical conformations assumed by the two polymers. PFA3 revealed an amorphous structure and exhibited peculiar thermal stability features (as indicated by TGA and DSC). Its emission spectra interest the violet-blue region and do not show any substantial red shift passing from solution to solid state, thus pointing out an aggregation prevention of terfluorene groups by means of the polyacetylene backbone

    Synthesis and activity of -Fe2O3 nanoparticles in the catalytic reduction of halonitroarenes under sustainable conditions

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    Abstract. The catalytic reduction of nitroarenes towards anilines is an important reaction from both academic and industrial points of view, being the resulting products important intermediates to produce dyes, agrochemicals, pigments, and pharmaceuticals. In addition, removal of nitroarene pollutants from water by reducing them into anilines is a valuable method to purify contaminated matrices. Such reductive reactions are frequently carried out by using noble metal catalysts [1], which are usually very active and recyclable in some cases. Recently, the use of earth abundant metal catalysts has gained great interest especially for economic reasons, as these materials are generally cheap and easy to be reached [2]. In this framework, iron oxides catalysts are very attractive because they are cheap and not toxic. Herein, we report on the synthesis of α-Fe2O3 nanoparticles (NPs) of size ranging from 50 to 80 nm starting from a porous organic polymer (POP) containing Fe(III) sites, which was in turn annealed at 400°C. The obtained NPs were characterized by SEM-EDX, XRPD, IR and TXRF and were employed as active and recyclable catalysts in the reduction of p-bromonitrobenzene into p-bromo-aniline, using hydrazine hydrate in ethanol, taken as the model reaction. [1] Dell’Anna, M.M.; Intini, S.; Romanazzi, G.; Rizzuti, A.; Leonelli, C.; Piccinni, F.; Mastrorilli, P. J. Mol. Catal. A: Chem. 2014, 395, 307–314. [2] Romanazzi, G.; Fiore, A.M.; Mali, M.; Rizzuti, A.; Leonelli, C.; Nacci, A.; Mastrorilli, P.; Dell'Anna, M. M. Mol. Catal., 2018, 446, 31–3
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