Grafted Sepiolites for the Removal of Pharmaceuticals in Water Treatment

The increased detection of pharmaceuticals in finished drinking water has become a growing cause of concern in recent years. The removal of atenolol, ranitidine, and carbamazepine by sepiolite, following functionalization of its surface by organosilane grafting, constituted the subject of this investigation. Silylated surfaces include octyl, γ-aminopropyl, 3-chloropropyl, and triphenyl moieties. The sorption of atenolol and ranitidine was higher on sepiolite functionalized with 3-chloropropyl, while carbamazepine showed a higher sorption on sepiolite with triphenyl groups. Filtration experiments of both ranitidine and carbamazepine on octyl- and triphenyl-sepiolite, respectively, showed a higher retention of ranitidine in comparison to carbamazepine, in spite of the fact that the number of sorption sites was lower due to its higher binding rate.Ministerio de Educación y Cultura CTM2013-42306-R, CTM2016-77168-

A targeted search for point sources of EeV photons with the Pierre Auger Observatory

We report a first measurement for ultrahigh energy cosmic rays of the correlation between the depth of shower maximum and the signal in the water Cherenkov stations of air-showers registered simultaneously by the fluorescence and the surface detectors of the Pierre Auger Observatory. Such a correlation measurement is a unique feature of a hybrid air-shower observatory with sensitivity to both the electromagnetic and muonic components. It allows an accurate determination of the spread of primary masses in the cosmic-ray flux. Up till now, constraints on the spread of primary masses have been dominated by systematic uncertainties. The present correlation measurement is not affected by systematics in the measurement of the depth of shower maximum or the signal in the water Cherenkov stations. The analysis relies on general characteristics of air showers and is thus robust also with respect to uncertainties in hadronic event generators. The observed correlation in the energy range around the 'ankle' at lg(E/eV) = 18.5-19.0 differs significantly from expectations for pure primary cosmic-ray compositions. A light composition made up of proton and helium only is equally inconsistent with observations. The data are explained well by a mixed composition including nuclei with mass A > 4. Scenarios such as the proton dip model, with almost pure compositions, are thus disfavored as the sole explanation of the ultrahigh-energy cosmic-ray flux at Earth. (C) 2016 The Author(s). Published by Elsevier B.V

Search for ultrarelativistic magnetic monopoles with the Pierre Auger observatory

We present a search for ultrarelativistic magnetic monopoles with the Pierre Auger observatory. Such particles, possibly a relic of phase transitions in the early Universe, would deposit a large amount of energy along their path through the atmosphere, comparable to that of ultrahigh-energy cosmic rays (UHECRs). The air-shower profile of a magnetic monopole can be effectively distinguished by the fluorescence detector from that of standard UHECRs. No candidate was found in the data collected between 2004 and 2012, with an expected background of less than 0.1 event from UHECRs. The corresponding 90% confidence level (C.L.) upper limits on the flux of ultrarelativistic magnetic monopoles range from 10(-1)9 (cm(2) sr s)(-1) for a Lorentz factor gamma = 10(9) to 2.5 x 10(-21) (cm(2) sr s)(-1) for gamma = 10(12). These results-the first obtained with a UHECR detector-improve previously published limits by up to an order of magnitude

Impact of atmospheric effects on the energy reconstruction of air showers observed by the surface detectors of the Pierre Auger Observatory

Atmospheric conditions, such as the pressure (P), temperature (T) or air density (rho proportional to P/T), affect the development of extended air showers initiated by energetic cosmic rays. We study the impact of the atmospheric variations on the reconstruction of air showers with data from the arrays of surface detectors of the Pierre Auger Observatory, considering separately the one with detector spacings of 1500m and the one with 750m spacing. We observe modulations in the event rates that are due to the influence of the air density and pressure variations on the measured signals, from which the energy estimators are obtained. We show how the energy assignment can be corrected to account for such atmospheric effects

Verificación estática de confidencialidad en un sistema de múltiples niveles de seguridad basado en Java bytecode

Debido al incremento en la cantidad e importancia de la información manejada por sistemas informáticos, también se incrementa la importancia de controlar la difusión de información privada de los usuarios. Los mecanismos de control del acceso y las técnicas criptográficas aseguran que la información sólo es accedida por entidades autorizadas, pero resultan insuficientes puesto que una vez que la información es accedida no existe control sobre su distribución. Extender el sistema de tipos de un lenguaje de programación agregando niveles de seguridad permite analizar estáticamente, antes de su ejecución, cómo un programa accede y utiliza la información confidencial. El creciente uso de código móvil –software obtenido de la red y ejecutado localmente, generalmente en Java bytecode– resalta la importancia de aplicar estos análisis de confidencialidad a lenguajes de bajo nivel. En este proyecto desarrollaremos un sistema de tipos para Java bytecode extendido con información de seguridad e implementaremos un chequeador de tipos que verifique la confidencialidad de la información local accedida por código móvil. También estudiaremos la desclasificación controlada de información, a fin de incluir en nuestro análisis a programas que inevitablemente revelan información confidencial, por ejemplo, al responder negativamente ante una contraseña inválida.Eje: Nuevas Tecnologías en desarrollo de Sistemas de SoftwareRed de Universidades con Carreras en Informática (RedUNCI

Feature Selection for Polymer Informatics: Evaluating Scalability and Robustness of the FS4RVDD Algorithm using Synthetic Polydisperse Datasets

The feature selection (FS) process is a key step in the Quantitative Structure-Property Relationship (QSPR) modeling of physicochemical properties in Cheminformatics. In particular, the inference of QSPR models for polymeric material properties constitutes a complex problem because of the uncertainty introduced by the polydispersity of these materials. The main challenge is how to capture the polydispersity information from the molecular weight distribution (MWD) curve to achieve a more effective computational representation of polymeric materials. To date, most of the existing QSPR techniques use only a single molecule to represent each of these materials, but polydispersity is not considered. Consequently, QSPR models obtained by these approaches are being oversimplified. For this reason, we introduced in a previous work a new FS algorithm called Feature Selection for Random Variables with Discrete Distribution (FS4RVDD), which allows dealing with polydisperse data. In the present paper, we evaluate both the scalability and the robustness of the FS4RVDD algorithm. In this sense, we generated synthetic data by varying and combining different parameters: the size of the database, the cardinality of the selected feature subsets, the presence of noise in the data, and the type of correlation (linear and nonlinear). Moreover, the performances obtained by FS4RVDD were contrasted with traditional FS techniques applied to different simplified representations of polymeric materials. The obtained results show that the FS4RVDD algorithm outperformed the traditional FS methods in all proposed scenarios, which suggest the need of an algorithm such as FS4RVDD to deal with the uncertainty that polydispersity introduces in human-made polymers.Fil: Cravero, Fiorella. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; ArgentinaFil: Schustik, Santiago. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas; ArgentinaFil: Martínez, María Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; ArgentinaFil: Vázquez, Gustavo. Universidad Católica del Uruguay; UruguayFil: Diaz, Monica Fatima. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Planta Piloto de Ingeniería Química. Universidad Nacional del Sur. Planta Piloto de Ingeniería Química; Argentina. Universidad Nacional del Sur. Departamento de Ingeniería Química; ArgentinaFil: Ponzoni, Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias e Ingeniería de la Computación. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación. Instituto de Ciencias e Ingeniería de la Computación; Argentina. Universidad Nacional del Sur. Departamento de Ciencias e Ingeniería de la Computación; Argentin

Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory

We present a combined fit of a simple astrophysical model of UHECR sources to both the energy spectrum and mass composition data measured by the Pierre Auger Observatory. The fit has been performed for energies above 5.10(18) eV, i.e. the region of the all-particle spectrum above the so-called "ankle" feature. The astrophysical model we adopted consists of identical sources uniformly distributed in a comoving volume, where nuclei are accelerated through a rigidity-dependent mechanism. The fit results suggest sources characterized by relatively low maximum injection energies, hard spectra and heavy chemical composition. We also show that uncertainties about physical quantities relevant to UHECR propagation and shower development have a non-negligible impact on the fit results

Combined fit of spectrum and composition data as measured by the Pierre Auger Observatory (vol 4, 038, 2017) (Erratum)

© Iop Publishing. Artículo firmado por más de 10 autores.Depto. de Estructura de la Materia, Física Térmica y ElectrónicaFac. de Ciencias FísicasTRUEpu