1,104 research outputs found

    Transition metal-based bimetallic catalysts for the chemoselective hydrogenation of furfuraldehyde

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    In this work, the liquid-phase chemoselective hydrogenation of furfural was studied, employing Pt, Rh and Ni-based catalysts. Bimetallic systems, containing different amounts of tin, were obtained by means of controlled surface reactions between a monometallic catalyst and Sn(C4H 9)4. The results obtained when monometallic catalysts were employed suggest a relationship between metal properties and the activity and selectivity obtained. All systems allowed obtaining furfuryl alcohol with high selectivity (99, 97 and 76% were achieved with Pt, Rh and Ni catalysts, respectively). The addition of tin has different effects on the three systems, both in terms of conversion and selectivity. An interesting result was obtained for the Ni-based catalysts, for which the addition of tin led to a significant increase in furfuryl alcohol selectivity and, depending on the Sn/Ni ratio, also to an increase in the catalytic activity of the system.Centro de Investigación y Desarrollo en Ciencias Aplicada

    Transition metal-based bimetallic catalysts for the chemoselective hydrogenation of furfuraldehyde

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    In this work, the liquid-phase chemoselective hydrogenation of furfural was studied, employing Pt, Rh and Ni-based catalysts. Bimetallic systems, containing different amounts of tin, were obtained by means of controlled surface reactions between a monometallic catalyst and Sn(C4H 9)4. The results obtained when monometallic catalysts were employed suggest a relationship between metal properties and the activity and selectivity obtained. All systems allowed obtaining furfuryl alcohol with high selectivity (99, 97 and 76% were achieved with Pt, Rh and Ni catalysts, respectively). The addition of tin has different effects on the three systems, both in terms of conversion and selectivity. An interesting result was obtained for the Ni-based catalysts, for which the addition of tin led to a significant increase in furfuryl alcohol selectivity and, depending on the Sn/Ni ratio, also to an increase in the catalytic activity of the system.Neste trabalho foi estudada a hidrogenação quimiosseletiva em fase líquida do furfural, empregando-se catalisadores baseados em Pt, Rh e Ni. Sistemas bimetálicos, contendo diferentes quantidades de estanho, foram obtidos por meio de reações de superfície controlada entre um catalisador monometálico e Sn(C4 H9)4. Quando foram utilizados catalisadores monometálicos, os resultados obtidos sugerem uma relação entre as propriedades do metal e da atividade e seletividade. Todos os sistemas permitiram a obtenção do álcool furfurílico com alta seletividade (99, 97 e 76% com catalisadores de Pt, Rh e Ni, respectivamente). A adição de estanho tem efeitos diferentes sobre os três sistemas, tanto em termos de conversão quanto na seletividade. Um resultado interessante foi obtido para os catalisadores baseados em Ni, para os quais a adição de estanho levou a um aumento significativo da seletividade do álcool furfurílico e, dependendo da razão Sn/Ni, também há um aumento na atividade catalítica do sistemaFil: Vetere, Virginia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Merlo, Andrea Beatriz. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Ruggera, José Fernando. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; ArgentinaFil: Casella, Mónica Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Investigación y Desarrollo en Ciencias Aplicadas "Dr. Jorge J. Ronco". Universidad Nacional de la Plata. Facultad de Ciencias Exactas. Centro de Investigación y Desarrollo en Ciencias Aplicadas; Argentin

    Silica-supported PtSn Catalysts Obtained Through Surface Organometallic Chemistry on Metals Techniques Using a Hydrosoluble Organotin Promoter : Application to the Selective Hydrogenation of α, β-Unsaturated Aldehydes and Ketones

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    In this paper we propose the preparation of a PtSn bimetallic catalyst through techniques derived from Surface Organometallic Chemistry on Metals (SOMC/M) using water as solvent. The system, PtSn0.2ac, was employed in the chemoselective liquid-phase hydrogenation of acetophenone, cinnamaldehyde and benzaldehyde. The results were compared with those obtained with a PtSn catalyst also prepared via SOMC/M, but using a conventional paraffinic solvent. The aqueous medium-prepared catalyst resulted to be as active in and selective to the desired product (unsaturated alcohols) as that obtained from n-heptane. This catalyst has the advantage of being prepared in a solvent compatible with the environment, without losing the superior characteristics of SOMC/M-based systems.Centro de Investigación y Desarrollo en Ciencias Aplicada

    Prey encounters and spatial memory influence use of foraging patches in a marine central place forager

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    This study was carried out as part of the Moray Firth Marine Mammal Monitoring Programme, a joint industry, academic and government strategic research project with funding from Beatrice Offshore Wind Ltd and Moray Offshore Renewables Ltd (MORL).Given the patchiness and long-term predictability of marine resources, memory of high-quality foraging grounds is expected to provide fitness advantages for central place foragers. However, it remains challenging to characterize how marine predators integrate memory with recent prey encounters to adjust fine-scale movement and use of foraging patches. Here, we used two months of movement data from harbour seals (Phoca vitulina) to quantify the repeatability in foraging patches as a proxy for memory. We then integrated these data into analyses of fine-scale movement and underwater behaviour to test how both spatial memory and prey encounter rates influenced the seals' area-restricted search (ARS) behaviour. Specifically, we used one month's GPS data from 29 individuals to build spatial memory maps of searched areas and archived accelerometery data from a subset of five individuals to detect prey catch attempts, a proxy for prey encounters. Individuals were highly consistent in the areas they visited over two consecutive months. Hidden Markov models showed that both spatial memory and prey encounters increased the probability of seals initiating ARS. These results provide evidence that predators use memory to adjust their fine-scale movement, and this ability should be accounted for in movement models.PostprintPeer reviewe

    Variation in foraging activity influences area-restricted search behaviour by bottlenose dolphins

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    Open Access via the Royal Society Agreement Beatrice Offshore Wind Ltd COWRIE Department of Energy & Climate Change, Scottish Government Fundación la Caixa (becas Posgrado, 2015) Marine Mammal Monitoring Programme (MMMP) Marine Scotland Science Moray Offshore Wind Farm (East) Ltd NatureScot Funding This project was made possible through the integration of O.F.B.'s PhD into a broader NatureScot and joint industry funded Marine Mammal Monitoring Programme (MMMP) that supports statutory monitoring of the Moray Firth SAC and offshore windfarm construction. We thank NatureScot, Marine Scotland Science, Beatrice Offshore Wind Ltd, Moray Offshore Wind Farm (East) Ltd, Department of Energy & Climate Change, Scottish Government, Oil & Gas UK and COWRIE for contributing funds or equipment to the MMMP. O.F.B. was funded through a studentship from the Fundación ‘la Caixa’ (Becas Posgrado, 2015). I.M.G., B.J.C. and P.M.T. were core funded by the University of Aberdeen but with salary support for the period of this study though contract to MMMP. V.I.M. and S.M.P. were funded through the MMMP. R.X.C. was core funded by Leibniz Institute for Zoo and Wildlife Research (IZW). Acknowledgements The authors gratefully acknowledge the support of the Maxwell High Performance Computing Cluster, funded by the University of Aberdeen, during the development of DOLPHIN-SPOT. We would also like to thank Claudia Aparicio Estaella for her help during the validation of the automatic detector. We acknowledge Bill Ruck, Moray First Marine and colleagues from the University of Aberdeen for assistance with the data collection and anonymous reviewers for comments that helped improve the manuscript.Peer reviewedPublisher PD

    Density of water adsorbed on bentonites: determination and effect on microstructural void ratio modelling

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    The ability of helium gas displacement pycnometry to characterise the reduction of adsorbed water density with increasing bentonite water content was tested. For this purpose, after obtaining the grain density (which was assumed to be constant), an intensive campaign of 45 experiments was carried out with two bentonites for a total of 90 determinations, obtaining very consistent water density results. Furthermore, the water retention curve of one of the two bentonites was fully characterised by 95 tests with a chilled-mirror dew-point psychrometer. The water content results were used to determine the microstructural void ratio, both assuming a constant water density and considering the variation of the adsorbed water density obtained with the helium pycnometer. It was verified that with the constant value, by assuming a lower water density (1 g/cm3) than the experimental (values of 1.20 g/cm3 were obtained under hygroscopic conditions), higher values of microstructural void ratios are predicted, up to 15% greater for a relative humidity of 70% (0.46 instead of 0.40). For higher relative humidities the comparison loses its consistency, since the presence of capillary water cannot be disregarded, and the calculation of the microstructural void ratio is based on the assumption that the water present in bentonite is mainly in the form of adsorbed water. However, this does not compromise the analysis performed, as the results obtained for lower relative humidity values provide enough information to demonstrate the relevance of the errors that can occur when deriving models of the microstructural void ratio without taking into account the variation of the density of adsorbed water.This study was funded by the Junta de Comunidades de Castilla-La Mancha and the European Regional Development Fund (European Union) through project SBPLY/19/180501/000222.Peer ReviewedPostprint (published version

    Insect-corn kernel interaction: Chemical signaling of the grain and host recognition by Sitophilus zeamais (Coleoptera: Curculionidae)

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    In living organisms, the cuticle has structural functions and is involved through chemical signaling in biological interactions such as plant-insect and provides protection against biotic and abiotic factors, thereby avoiding desiccation or predators'attack. The objective of this study was to investigate the participation of the epicuticle in the interaction of the maize kernel and the maize weevil Sitophilus zeamais. For this study the extraction ofepicuticle was carried on and the extract was analyzed by GC-MS. Digital photographs ofcross sections of grains with and without epicuticle were taken, and behavior bioassayswere carried out with both grains with and without epicuticle and epicuticle extracts. TheGC-MS analysis of the epicuticle extract demonstrated the presence of aliphatichydrocarbons, alcohols, ethers, fatty acids, sterols and their derivatives. The results ofpreference bioassays showed that the epicuticle of maize has a primordial role in itsinteraction with S. zeamais participating in the recognition and attraction to the foodsource. According to these results, in the assay of kernels' susceptibility to insect attack,kernels without epicuticle were significatively less damage than kernels with epicuticle. In progeny assays, the exposition of S. zeamais adults to kernels without epicuticle caused a reduction in progeny, indicating that it could regulate the reproduction of S. zeamais. In addition, the compounds present in the epicuticle extract may act assignalling molecules and developmental regulators. This study reveals the effect of the maize kernel epicuticle on Sitophilus behavior and contributes to the understanding of their interaction.Fil: Usseglio, Virginia Lara. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; ArgentinaFil: Zaio, Yésica Paola. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; ArgentinaFil: Dambolena, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Ciencias y Tecnología de los Alimentos; ArgentinaFil: Merlo, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias. Departamento de Recursos Naturales. Cátedra de Microbiología Agrícola; ArgentinaFil: Peschiutta, María Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Zunino, María Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; Argentina5th Congress of the Latin American Association of Chemical EcologyValparaisoChileAsociación Latino Americana de Ecología Químic

    Ecological interactions affect the bioactivity of medicinal plants

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    Essential oils produced by medicinal plants possess important bioactive properties (antibacterial, antioxidant) of high value for human society. Pollination and herbivory can modify the chemical defences of plants and therefore they may influence the bioactivity of essential oils. However, the effect of ecological interactions on plant bioactivity has not yet been evaluated. We tested the hypothesis that cross-pollination and simulated herbivory modify the chemical composition of essential oils, improving the bioactive properties of the medicinal plant Lepechinia floribunda (Lamiaceae). Through controlled experiments, we showed that essential oils from the outcrossed plant progeny had a higher relative abundance of oxygenated terpenes and it almost doubled the bacteriostatic effect on Staphylococcus aureus, compared to inbred progeny (i.e., progeny produced in absence of pollinators). Herbivory affected negatively and positively the production of rare compounds in inbred and outcrossed plants, respectively, but its effects on bioactivity still remain unknown. We show for the first time that by mediating cross-pollination (indirect ecosystem service), pollinators can improve ecosystem services linked to the biological activity of plant’s essential oils. We stress the importance of the qualitative component of pollination (self, cross); an aspect usually neglected in studies of pollination services.Fil: Camina, Julia Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Usseglio, Virginia Lara. Universidad Nacional de Córdoba; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Marquez, Victoria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Merlo, Carolina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Dambolena, José Sebastián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; ArgentinaFil: Zygadlo, Julio Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentina. Universidad Nacional de Córdoba; ArgentinaFil: Ashworth, Lorena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto Multidisciplinario de Biología Vegetal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto Multidisciplinario de Biología Vegetal; Argentin

    Transition metal-based bimetallic catalysts for the chemoselective hydrogenation of furfuraldehyde

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    In this work, the liquid-phase chemoselective hydrogenation of furfural was studied, employing Pt, Rh and Ni-based catalysts. Bimetallic systems, containing different amounts of tin, were obtained by means of controlled surface reactions between a monometallic catalyst and Sn(C4H 9)4. The results obtained when monometallic catalysts were employed suggest a relationship between metal properties and the activity and selectivity obtained. All systems allowed obtaining furfuryl alcohol with high selectivity (99, 97 and 76% were achieved with Pt, Rh and Ni catalysts, respectively). The addition of tin has different effects on the three systems, both in terms of conversion and selectivity. An interesting result was obtained for the Ni-based catalysts, for which the addition of tin led to a significant increase in furfuryl alcohol selectivity and, depending on the Sn/Ni ratio, also to an increase in the catalytic activity of the system.Centro de Investigación y Desarrollo en Ciencias Aplicada

    Characterising underwater noise and changes in harbour porpoise behaviour during the decommissioning of an oil and gas platform

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    This study was funded by the UK Department for Business, Energy & Industrial Strategy (BEIS) Offshore Energy Strategic Environmental Assessment research programme under contracts OESEA-20-125 and OESEA-21-133, using equipment previously purchased by UK Department of Energy and Climate Change, Scottish Government, Oil and Gas UK, COWRIE and Moray Offshore Renewables Ltd.Peer reviewe
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