102 research outputs found

    TiO2-Low Band Gap Semiconductor Heterostructures for Water Treatment Using Sunlight-Driven Photocatalysis

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    Heterogeneous photocatalysis is a promising advanced oxidation process for water purification, given its potential to fully oxidize organic pollutants and to inactivate microorganisms. Due to its versatility and high performance in a broad range of conditions, titanium dioxide (TiO2)-based photocatalysis has been systematically used at laboratory scale to treat water of different quality. Even though TiO2 is an exceptional photocatalyst, its broad band gap value (3.2 eV) makes necessary the use of UV light to achieve the photoactivation. This results in the underutilization of the material in sunlight-driven photocatalysis schemes. In order to overcome this handicap, the synthesis of heterostructures using low band gap semiconductors coupled with TiO2 has brought exceptional materials for visible light-driven photocatalysis. In this chapter, the fundamentals of the synthesis and photoactivation of TiO2-low band gap semiconductor heterostructures are explored. The mechanisms leading to the increase of the photocatalytic activity of such heterostructures are described. A summary of the available data on the photocatalytic performance of TiO2-based heterostructures is presented, in terms of degradation of organic pollutants in water using visible light and sunlight. A comparison of the depuration performance of powdered and thin film heterostructures is given at the end of the chapter

    A nonequilibrium renormalization group approach to turbulent reheating

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    We use nonequilibrium renormalization group (RG) techniques to analyze the thermalization process in quantum field theory, and by extension reheating after inflation. Even if at a high scale Λ\Lambda the theory is described by a non-dissipative λϕ4\lambda\phi^{4} theory, the RG running induces nontrivial noise and dissipation. For long wavelength, slowly varying field configurations, the noise and dissipation are white and ohmic, respectively. The theory will then tend to thermalize to an effective temperature given by the fluctuation-dissipation theorem.Comment: 8 pages, 2 figures; to appear in J. Phys. A; more detailed account of the calculation of the noise and dissipation kernel

    Inflation and nonequilibrium renormalization group

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    We study de spectrum of primordial fluctuations and the scale dependence of the inflaton spectral index due to self-interactions of the field. We compute the spectrum of fluctuations by applying nonequilibrium renormalization group techniques.Comment: 6 pages, 1 figure, submitted to J. Phys.

    Targeting Beta-Blocker Drug–Drug Interactions with Fibrinogen Blood Plasma Protein: A Computational and Experimental Study

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    In this work, one of the most prevalent polypharmacology drug–drug interaction events that occurs between two widely used beta-blocker drugs—i.e., acebutolol and propranolol—with the most abundant blood plasma fibrinogen protein was evaluated. Towards that end, molecular docking and Density Functional Theory (DFT) calculations were used as complementary tools. A fibrinogen crystallographic validation for the three best ranked binding-sites shows 100% of conformationally favored residues with total absence of restricted flexibility. From those three sites, results on both the binding-site druggability and ligand transport analysis-based free energy trajectories pointed out the most preferred biophysical environment site for drug–drug interactions. Furthermore, the total affinity for the stabilization of the drug–drug complexes was mostly influenced by steric energy contributions, based mainly on multiple hydrophobic contacts with critical residues (THR22: P and SER50: Q) in such best-ranked site. Additionally, the DFT calculations revealed that the beta-blocker drug–drug complexes have a spontaneous thermodynamic stabilization following the same affinity order obtained in the docking simulations, without covalent-bond formation between both interacting beta-blockers in the best-ranked site. Lastly, experimental ultrasound density and velocity measurements were performed and allowed us to validate and corroborate the computational obtained resultsThis research was funded by FCT/MCTES through national funds (Michael González-Durruthy, Riccardo Concu, and M. Natália D.S. Cordeiro), grant UID/QUI/50006/2020, as well as by Xunta de Galicia (Juan M. Ruso), grant ED41E2018/08S

    Estudo da variação da concentração sérica de fenobarbital em cães cronicamente medicados

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    In order to evaluate daily changes of concentration of phenobarbital during the interval of 12 hours of its administration, serum phenobarbital concentration were measured each two hours in 30 dogs submitted to the referred drug therapy for at least one month. All serum phenobarbital drug concentration were determined by use of a fluorecence polarization immunoassay. The values of half-lives obtained varied from 13 to 131 hours, most dogs reached steaty state serum concentrations by 15 days, and all dogs after four weeks. Therefore, clinicians should monitor serum phenobarbital concentrations four weeks after initiating treatment or after a change in dosage. There was significant difference among the averages of the samples two and four hours (peak) with the ones samples colected immediately before, and eight, 10 and 12 hours after its administration. In order to monitore serum phenobarbital concentrarions, its is suggest that blood collection is measured just before the dose or at any time between eight and 12 hours after its administration. If a concern arises regarding toxicity, a second sample should be colleted between two and four hours after phenobarbital administration.Com a finalidade de avaliar a variação na concentração sérica do fenobarbital durante um intervalo de 12 horas da sua administração, as concentrações séricas foram mensuradas a cada duas horas em 30 cães cronicamente medicados, durante no mínimo um mês. A determinação dos valores séricos de fenobarbital, por meio de Imunofluorescência polarizada. Os valores de meia-vida obtidos variaram de 13-131 horas, sendo que a maioria dos cães atingiram o estado de equilíbrio dinâmico por volta de 15 dias, e todos após quatro semanas, recomendando-se assim monitoração após quatro semanas do início da terapia ou após cada ajuste de dose. Houve diferença significante entre as médias das amostras coletadas duas e quatro horas (pico) com as das amostras coletadas imediatamente antes e oito, 10 e 12 horas após sua administração. Assim, para a monitoração, pode-se realizar a coleta sangüínea, imediatamente antes da administração do fenobarbital, ou em qualquer horário, entre oito a 12 horas após sua administração e nos casos suspeitos de intoxicação uma segunda amostra pode ser coletada dentro de duas a quatro horas após a sua administração

    Brønsted Base Catalyzed One-Pot Synthesis od Stereodefined Six-Member Carbocycles Featuring Transient Trienolates and a Key Intramolecular 1,6-Addition

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    Acatalyst-driven one-pot reaction sequence is developed for the enantio- and diastereoselective synthesis of tetrasubstituted cyclohexenes from simple unsaturated ketones or thioesters.The method involves atertiary amine/squara- mide-catalyzed a-selective addition of transiently generated trienolates to nitroolefins,subsequent base-catalyzed double bond isomerization, and an intramolecular (vinylogous) 1,6- addition reaction, arare key carbocyclization step that proceeded with essentially perfect stereocontrolSupport has been provided by the University of the Basque Country UPV/EHU (UFI QOSYC 11/22), the Basque Government (GV grant No IT-1236-19), and the Ministerio de Economía y Competitividad (MEC Grant CTQ2016-78487-C2), Spain. I.I. and O.O. thank GV for a fellowship. G.Z. and E.G.-B thank the European Funding Horizon 2020-MSCA (ITN-EJD CATMEC 14/06-721223)

    LLAMAS: An acquisition, control and monitoring software for LLAMA

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    The Large Latin American Millimeter Array is a 12?m Nasmyth antenna to be installed at 4850 m above see level in the Argentinian Atacama Region. LLAMA will operate both in single dish mode and as a VLBI station. LLAMAS is the software, under development, that will acquire the data from the receivers, control the different devices and monitor the safe functioning of the sub-parts. It is based on the ALMA Common Software (ACS), that implements the concept of containers and distributed component objects. It is programmed in JAVA, C++ andPython, and uses the Common Object Request Broker Architecture (CORBA) infrastructure to exchange messages between the subsystems. LLAMAS must be as heterogeneous as the telescope operation: single dish observing modes with simultaneous readouts from single-pixel receivers, and two different polarization channels in continuum (total?power) or spectral mode, single-dish from multi-pixel cameras, and coordinated interferometric observations as a VLBI station. Since the antenna will be located at a very high altitude, the control room will be at a safer lower place 20 km away, and therefore the operation will be remote. Moreover, the high altitude requires the use of disk-less computers and the immediate data transfer to the control room through a fast connection link. It is also envisaged a Web based observing proposal submission and data querying system for the astronomers, making the whole observing process world wide available. In this work we present the conceptual software design of the observation cycle, that we call from the Astronomer to the Astronomer (A2A), and we describe the different subsystems needed to accomplish this goal.Fil: Giménez de Castro, Guillermo C.. Universidade Presbiteriana Mackenzie; BrasilFil: Larrarte, Juan Jose. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Ibsen, J. J.. Atacama Large Millimiter/submillimeter Array; ChileFil: Abraham, Zulema. Universidade do Sao Paulo. Instituto de Astronomia, Geofísica e Ciências Atmosféricas; BrasilFil: Bareilles, Federico Ariel. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Hauscarriaga, Fernando Pablo. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto Argentino de Radioastronomía. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto Argentino de Radioastronomía; ArgentinaFil: Strauss, C.. National Institute For Space Research; BrasilFil: Zanella, D.. Universidade do Sao Paulo. Instituto de Astronomia, Geofísica e Ciências Atmosféricas; BrasilXXXIX Reunião Anual da Sociedade Astronômica BrasileiraOuro PretoBrasilSociedade Astronômica Brasileir

    Dataset of characteristic remanent magnetization and magnetic properties of early Pliocene sediments from IODP Site U1467 (Maldives platform)

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    This data article describes data of magnetic stratigraphy and anisotropy of isothermal remanent magnetization (AIRM) from "Magnetic properties of early Pliocene sediments from IODP Site U1467 (Maldives platform) reveal changes in the monsoon system" [1]. Acquisition of isothermal magnetization on pilot samples and anisotropy of isothermal remanent magnetization are reported as raw data; magnetostratigraphic data are reported as characteristic magnetization (ChRM).info:eu-repo/semantics/publishedVersio
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