DRIFT+MS Quantitative Study of the CO Oxidation on Gold supported on Ceria

The steps of the CO oxidation reaction on a Au/CeO2 catalyst was quantitatively investigated using a novel DRIFT cell/micro-reactor. The design and characterization of this DRIFT cell/micro-reactor, coupled with mass spectrometry, to perform operando and transient studies of reactions at the gas/solid interface is presented. The cell was modeled and experimentally validated to obtain kinetic parameters of reactions under true chemical control conditions. Light-off curves of activity vs temperature, step-reaction and excitation modulation spectroscopy (MES) experiments were carried out. TOF and apparent activation energy were identical to the measured using a conventional reactor. The simultaneous detection of gas phase concentrations by MS and the intensity of the IR signals allowed the quantification of surface species active in the reaction: i) Au0-CO (2110 cm-1), Au+-CO (2125 cm-1), ii) carbonate adsorbed on the ceria support (1700-1200 cm-1). Moreover, the amount of adsorbed oxygen could also be quantified. Kinetic constants of CO adsorption and oxidation were measured.Fil: Aguirre, Alejo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Collins, Sebastián Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaVI San Luis School and Conference on Surfaces, Interfaces and CatalysisSanta FeArgentinaInstituto de Desarrollo Tecnológico para la Industria QuímicaUniversidad Nacional del Litora

Dynamic Restaurants Quality Mapping Using Online User Reviews

Millions of users post comments to TripAdvisor daily, together with a numeric evaluation of their experience using a rating scale of between 1 and 5 stars. At the same time, inspectors dispatched by national and local authorities visit restaurant premises regularly to audit hygiene standards, safe food practices, and overall cleanliness. The purpose of our study is to analyze the use of online-generated reviews (OGRs) as a tool to complement official restaurant inspection procedures. Our case study-based approach, with the help of a Python-based scraping library, consists of collecting OGR data from TripAdvisor and comparing them to extant restaurants’ health inspection reports. Our findings reveal that a correlation does exist between OGRs and national health system scorings. In other words, OGRs were found to provide valid indicators of restaurant quality based on inspection ratings and can thus contribute to the prevention of foodborne illness among citizens in real time. The originality of the paper resides in the use of big data and social network data as a an easily accessible, zero-cost, and complementary tool in disease prevention systems. Incorporated in restaurant management dashboards, it will aid in determining what action plans are necessary to improve quality and customer experience on the premises

Synergetic Effect of Bimetallic Au-Ru/TiO2 Catalysts for CO and Methanol Complete Oxidation

It is well known that gold nanoparticles supported on metal oxides are active in various reactions of environmental importance.1 Particularly, supported Au nanoparticles is well known as very efficient catalysts for CO oxidation at low temperature.1 It is also possible to perform the oxidation of some volatile organic compounds (VOCs) such as light hydrocarbons and alcohols at room temperature. The most efficient and low-cost method for their abatement is the catalytic combustion to CO2 and H2O, preferentially at low temperatures. On the other hand, the preparation of bimetallic catalysts has been proposed as an alternative to improve the activity, stability and/or selectivity of gold catalysts. In this way, the addition of a second metal could modify the physicochemical and electronic properties of the first metal.2 Ruthenium-based catalysts have been studied in VOCs oxidation reaction, and in conjunction with gold, they exhibit an improvement in catalytic activity.Fil: Calzada, L.. Universidad Nacional Autónoma de México; MéxicoFil: Collins, Sebastián Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Delannoy, L.. Universite de Paris VI; FranciaFil: Louis, C.. Universite de Paris VI; FranciaFil: Ortalan, V.. Universidad Nacional Autónoma de México; MéxicoFil: Zanella, R.. Universidad Nacional Autónoma de México; MéxicoGold 2018ParisFranciaUniversité Pierre et Marie Curi

Molecular recognition of an acyl–enzyme intermediate on the lipase B from <i>Candida antarctica</i>

This investigation provides evidence of the acyl enzyme species involved in the interaction of R/Sketoprofen with the lipase B from Candida antarctica. The interaction between the profen and the enzyme was studied by in situ time-resolved ATR-FTIR under both static and transient conditions. Particularly, modulation excitation spectroscopy (MES) with phase sensitive detection (PSD) allowed us to univocally distinguish the signals belonging to the interaction between ketoprofen and the enzyme from the strong background signals. These experimental tools coupled with theoretical DFT analysis allowed us to propose various species derived from the interaction of ketoprofen with serine through H bonding (without reaction) and the acyl enzyme species (ester bond formation) which are the intermediates in the biocatalytic assisted esterification and hydrolysis using lipases.Centro de Investigación y Desarrollo en Ciencias AplicadasFacultad de Ciencias Exacta

Catalytic and molecular insights of the esterification of ibuprofen and ketoprofen with glycerol

The esterification of rac-ibuprofen and rac-ketoprofen with glycerol catalyzed with the commercial biocatalyst Novozym® 435 was investigated at 45 °C with various profen: glycerol molar ratios using 2-propanol as co-solvent in a batch type reaction. The conversion of rac-ibuprofen reached 46%, with an enantiomeric excess towards the S-enantiomer of 42%. When 1:4 ibuprofen:glycerol molar ratio was assayed, 75% of the R-ibuprofen reacted with glycerol towards the monoglyceride with 99% selectivity, which is highly relevant in the field of prodrugs synthesis. The conversion of rac-ketoprofen was lower, 17 % vs. 46 % of rac-ibuprofen, and the esterification afforded both the monoglyceride (70%) and diglyceride (30%) regardless of the ketoprofen:glycerol molar ratio. Investigations of the esterification at molecular level through concentration-modulated infrared spectroscopy, static ATR-FTIR and in situ Raman spectroscopy showed the continuous decay of the species belonging to rac-ibuprofen and glycerol providing further evidences of the reaction. Moreover, the interaction of CALB with ibuprofen modifies the contribution of the ordered structures of the lipase, which might be related with the improved catalytic performance in the esterification of that profen.Fil: Toledo, Victoria. 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: José, Carla. 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: Llerena Suster, Carlos Rafael. Facultad de Ciencias Exactas, Universidad Nacional de la Plata; Argentina. 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: Collins, Sebastián Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Portela, Raquel. Consejo Superior de Investigaciones Científicas. Instituto de Tecnología Química; EspañaFil: Bañares, Miguel A.. Consejo Superior de Investigaciones Científicas. Instituto de Tecnología Química; EspañaFil: Briand, Laura Estefania. 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

Gold catalysts supported on cerium-gallium mixed oxide for the carbon monoxide oxidation and water gas shift reaction

The synthesis, characterization and catalytic properties of gold supported on ceria, gallia and a cerium-gallium mixed oxide were investigated. The nanostructural characterization of the cerium-gallium support (nominal atomic composition Ce80Ga20) showed that gallium(III) cations are homogenously distributed into the ceria matrix by substituting cerium(IV) cations of the fluorite-type structure of ceria. Au was added to the supports by the deposition-precipitation method using urea. High Au dispersions were achieved for all the fresh materials (D > 60%). The CO oxidation and the water gas shift (WGS) reaction were tested on the whole set of catalysts. All the supported-gold catalysts showed high activity for the CO oxidation reaction. However, those containing gallium in their formulation deactivated due to gold particle sinterization. Au(2%)/CeO2 was the most active material for the WGS reaction, and the Au(2%)/Ce80Ga20 was as active as a Au(3%)/Ce68Zr32 catalyst for CO oxidation, and even more active than the reference catalyst of the World Gold Council, Au(2%)/TiO2.Fil: Vecchietti, María Julia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Collins, Sebastián Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Delgado, Juan José. Universidad de Cadiz. Facultad de Ciencias. Departamento de Cs.de Los Materiales E Ing.metalurgica y Quim.inorg.; EspañaFil: Malecka, Malgorzta. Universidad de Cadiz. Facultad de Ciencias. Departamento de Cs.de Los Materiales E Ing.metalurgica y Quim.inorg.; EspañaFil: del Rio, Eloy. Universidad de Cadiz. Facultad de Ciencias. Departamento de Cs.de Los Materiales E Ing.metalurgica y Quim.inorg.; EspañaFil: Chen, Xiaowei. Universidad de Cadiz. Facultad de Ciencias. Departamento de Cs.de Los Materiales E Ing.metalurgica y Quim.inorg.; EspañaFil: Bernal, Serafín. Universidad de Cadiz. Facultad de Ciencias. Departamento de Cs.de Los Materiales E Ing.metalurgica y Quim.inorg.; EspañaFil: Bonivardi, Adrian Lionel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; Argentin

Investigación de sitios ácidos del heteropoliácido de Wells Dawson por adsorción de piridina

El objetivo de esta investigación fue estudiar la interacción de la piridina con el ácido fosfotúngstico de Wells Dawson H6P2W18O62.13H2O másico con el fin de determinar la naturaleza y número de sitios ácidos Brönsted y Lewis presentes en el mismo. Este estudio se realizó mediante la técnica de quimisorción de piridina a temperatura ambiente y análisis por espectroscopia infrarroja in situ de la evolución de la interacción entre la molécula sonda y el material. La evidencia experimental permitió concluir que la compresión del heteropoliácido fosfotúngtico durante la preparación de una pastilla auto-soportada como también la baja superficie específica del material inhiben la adsorción de la molécula sonda.This contribution investigates the interaction between pyridine and bulk phosphotungstic Wells Dawson heteropolyacid H6P2W18O62.13H2O in order to determine the nature and number of both Lewis and Brønsted acid sites. This study was performed through the chemisorption of pyridine at R.T. followed by the continuous analysis of the material with in situ infrared spectroscopy. The results allowed to conclude that the compression of the material during the preparation of the self-supported wafer and the low surface area of the heteropolyacid inhibit the adsorption of the molecular probe.Fil: Matkovic, Silvana Raquel. 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: Bosco, Marta Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Collins, Sebastián Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Briand, Laura Estefania. 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

Riparian buffer strips influence nitrogen losses as nitrous oxide and leached N from upslope permanent pasture

Riparian buffer strips can have a significant role in reducing nitrogen (N) transfers from agricultural land to freshwater primarily via denitrification and plant uptake processes, but an unintended trade-off can be elevated nitrous oxide (N2O) production rates. Against this context, our replicated bounded plot scale study investigated N2O emissions from un-grazed ryegrass pasture served by three types of riparian buffer strips with different vegetation, comprising: (i) grass riparian buffer with novel deep-rooting species, (ii) willow (young trees at establishment phase) riparian buffer, and (iii) deciduous woodland (also young trees at establishment phase) riparian buffer. The experimental control was ryegrass pasture with no buffer strip. N2O emissions were measured at the same time as total oxidized N in run-off, and soil and environmental characteristics in the ri parian buffer strips and upslope pasture between 2018 and 2019. During most of the sampling days, the no-buffer control treatment showed significantly (P < 0.05) greater N2O fluxes and cumulative N2O emissions compared to the remainder of the treatments. Our results also showed that the grass riparian buffer strip is a sink of N2O equivalent to − 2310.2 g N2O-N ha− 1 day− 1 (95% confidence interval:− 535.5 to 492). Event-based water quality results obtained during storms (12 November 2018 and 11 February 2019) showed that the willow riparian buffer treatment had the highest flow-weighted mean N concentrations (N-FWMC) of 0.041 ± 0.022 and 0.031 ± 0.015 mg N L− 1, when compared to the other treatments. Our 9-month experiment therefore, shows that ri parian buffer strips with novel deep-rooting grass can therefore potentially address emissions to both water and air. The results imply that over a shorter timeline similar to the current study, the grass riparian buffer strip can potentially address N emission to both air and water, particularly when serving a permanent pasture in similar settings as the current experiment.Fil: Dlamini, J.C. Crop and Climate Sciences. Departament of Soil; Sudáfrica. Rothamsted Research. Sustainable Agriculture Sciences; Reino Unido. University of Pretoria. Department of Plant and Soil Sciences; SudáfricaFil: Cardenas, L.M. Rothamsted Research. Sustainable Agriculture Sciences; Reino Unido.Fil: Tesfamarian, E.H. University of Pretoria. Department of Plant and Soil Sciences; SudáfricaFil: Dunn, R.M. Rothamsted Research. Sustainable Agriculture Sciences; Reino Unido.Fil: Loick, N. Rothamsted Research. Sustainable Agriculture Sciences; Reino Unido.Fil: Charteris, A.F. Rothamsted Research. Sustainable Agriculture Sciences; Reino Unido.Fil: Cocciaglia, L. Università degli Studi di Perugia. Dipartimento di Scienze Agrarie, Alimentari e Ambientali; ItaliaFil: Vangeli, Sebastián. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Clima y Agua; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Agronomía. Departamento de Ingeniería Agrícola y Uso de la Tierra. Cátedra de Manejo y Conservación de Suelo; ArgentinaFil: Blackwell, M.S.A. Rothamsted Research. Sustainable Agriculture Sciences; Reino Unido.Fil: Upadhayay, H.R. Rothamsted Research. Sustainable Agriculture Sciences; Reino Unido.Fil: Hawkins, J.M.B. Rothamsted Research. Sustainable Agriculture Sciences; Reino Unido.Fil: Evans, J. Rothamsted Research. Computational and Analytical Sciences; Reino UnidoFil: Collins, A.L. Rothamsted Research. Sustainable Agriculture Sciences; Reino Unido

Identificación de intermediario de reacción de la enzima lipasa B de candida antarctica

Las lipasas (EC 3.1.1.3, triacilglicerol hidrolasas) son enzimas hidrolíticas ampliamente usadas en numerosas reacciones y procesos industriales debido a su habilidad para catalizar diversas reacciones.Centro de Investigación y Desarrollo en Ciencias Aplicada

Identificación de intermediario de reacción de la enzima lipasa B de candida antarctica

Las lipasas (EC 3.1.1.3, triacilglicerol hidrolasas) son enzimas hidrolíticas ampliamente usadas en numerosas reacciones y procesos industriales debido a su habilidad para catalizar diversas reacciones.Centro de Investigación y Desarrollo en Ciencias Aplicada