1,544 research outputs found

    Embeddings between grand, small and variable Lebesgue spaces

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    We give conditions on the exponent function p()p(\cdot) that imply the existence of embeddings between grand, small and variable Lebesgue spaces. We construct examples to show that our results are close to optimal. Our work extends recent results by the second author, Rakotoson and Sbordone.Comment: Final version to appear in Math. Note

    Solubility of triglycerides in aqueous ethanol

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    INSTABILITY AND TRADE IN CURRENCY AREAS

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    We present a model of a currency area in which labor markets of country members are isolated but there is trade among these countries. When a country experiences a negative (resp. positive) shock, inflation goes down (up). This causes two effects. On the one hand the real interest rate of this country increases (decreases). On the other hand the goods produced in this country become more (less) competitive. We show that the stability of the system depends on several factors, including a large competitive effect, how inflation expectations are formed and fiscal policy. In general, stability requires a trade-off between the rationality of expectations and budget balance.

    Application of heterogeneous catalysts in ozonation of model compounds in water

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    The presence of micropollutants, particularly pesticides, in surface waters across Canada has been of concern not only for their environmental impact, but also for their potential effects on human health and recalcitrant nature to conventional water treatment methods. Although ozone has been mainly applied for disinfection of drinking water, oxidation of trace organics by ozonation has been considered potentially effective. In an effort to meet increasingly stringent drinking water regulations, different solid catalysts have been used to enhance the removal of water contaminants by ozonation. In spite of the increasing number of data demonstrating the effectiveness of heterogeneous catalytic ozonation, the influence of different factors on the efficiency of micropollutants oxidation is still unclear. In the present work, application of three solid catalysts in ozonation of two model micropollutants in pure water was examined using a laboratory-scale reaction system over a range of operating conditions. The three catalysts investigated were activated carbon, alumina, and perfluorooctyl alumina, and the two model micropollutants were the pesticides atrazine and 2,4-dichlorophenoxyactic acid. The effects of solution pH, presence of a radical scavenger, pesticide adsorption on catalyst, and catalyst dose on micropollutant removal were investigated. Solution pH was found to significantly influence the catalyst ability to decompose ozone into free hydroxyl radicals. The effect of these free radicals was markedly inhibited by the radical scavenger resulting in a negative impact on pesticides degradation. In general, the removal rate of pesticides was found to increase with increasing doses of catalyst. In the ozonation process in the presence of activated carbon, atrazine removal rates increased four and two times when using a catalyst dose of 0.5 g L-1 at pH 3 and 7, respectively, whereas observed reaction rates for 2,4-D increased over 5 times in the presence of 1 × 10-4 M tert-butyl alcohol at pH 3. In the ozonation system catalyzed by 8 g L-1 alumina, the observed reaction rate constant of atrazine removal notably improved at neutral pH by doubling the micropollutant removal rate. For the pesticide 2,4-D in the presence of 1 × 10-4 M tert-butyl alcohol at pH 5, the observed removal rate was over ten times higher than that for the non-catalytic ozonation process using also using a catalyst dose of 8 g L-1. Modification of alumina to produce perfluorooctyl alumina resulted in a material able to significantly adsorb atrazine, while not exhibiting affinity for adsorption of 2,4-D. In spite of its adsorptive properties, perfluorooctyl alumina was found to enhance neither molecular ozone reactions nor ozone decomposition into hydroxyl radicals. Thus, the observed removal rates for atrazine and 2,4-D by ozonation in the presence of perfluorooctyl alumina did not increase significantly

    A Eficácia do Programa de Aperfeiçoamento de Professores (PROMEP) em Universidades Públicas Estaduais no México

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    This article evaluates the effectiveness of Promep, a faculty improvement program implemented by Mexico’s Federal Department of Public Education (SEP) since 1996 to improve the academic qualifications, performance, and organization of faculty at the public higher education institutions. This evaluation examines the degree to which Promep has achieved its quantitative objectives with regard to the Public State Universities (PSU), which is the higher education subsystem that Promep has been active in for the longest period of time (1996–2013). The evaluation is based on numerous data reports published by Promep, the SEP, and other federal institutions as well as on essential subsystem-wide indicators calculated from data individually collected from each of the PSU for the purposes of this study. The results indicate that Promep has significantly improved the academic qualifications, performance, and organization of the full-time faculty staff of the PSU, but also that by 2013 the program has not been able to meet the quantitative goals it expected to achieve by late 2008, which was its initial deadline. The study suggests that the failure to achieve these initial and manageable goals has occurred mostly because many PSU have allowed the infringement of their own faculty recruitment, permanence, and promotion regulations and Promep has failed to stop these practices through the establishment of more drastic strategies, such as binding agreements and penalization schemes. Este artículo evalúa la efectividad del Programa de Mejoramiento del Profesorado (Promep) implementado por la Secretaría de Educación Pública (SEP) de México desde 1996 para mejorar el perfil, desempeño y organización académica de la planta docente de las instituciones públicas de educación superior en el país. Esta evaluación se enfoca en el grado en el que Promep ha alcanzado los objetivos que él mismo se propuso alcanzar en el subsistema de las Universidades Públicas Estatales (UPES), el cual es la división del sistema de educación superior mexicano en el que Promep estuvo activo por más años (1996-2013). La evaluación se basa en la información extraída de varios reportes publicados por Promep, a través de la SEP, y otras instituciones federales, así como en datos e indicadores obtenidos de manera directa de cada una de las UPES incluidas en el estudio. Los resultados indican que Promep ha mejorado significativamente el perfil, desempeño y organización académica del profesorado de tiempo completo de las UPES, pero también que para el 2013 el programa aún no había sido capaz de cumplir con los objetivos cuantitativos que él mismo se propuso alcanzar para finales del 2008. El estudio sugiere que este fracaso para alcanzar los objetivos iniciales se debe principalmente al hecho de que muchas UPES han cometido o permitido la violación de las regulaciones sobre reclutamiento, permanencia y promoción del profesorado y al hecho de que Promep no ha establecido estrategias more drásticas para detener estas violaciones, como la firma de acuerdos jurídicos que incluyan penalizaciones para las UPES que cometan violaciones.O presente artigo avalia a eficácia do Programa de Melhoramento de Professores (PROMEP) implementado pelo Ministério de Educação Pública (SEP) do México desde 1996 para melhorar o perfil e desempenho e organização acadêmica do corpo docente das instituições públicas de ensino superior no país. Esta avaliação incide sobre o grau em que PROMEP alcançou os objetivos que ele se propõe atingir no subsistema de Universidades Públicas Estaduais (UPES), que é a divisão do sistema mexicano de ensino superior em que PROMEP esteve ativo por mais anos (1996-2013). A avaliação é baseada na informação extraída dos diversos relatórios publicados pelo PROMEP, através do SEP, e de outras instituições federais, bem como de dados e indicadores obtidos diretamente de cada UPES incluídas no estudo. Os resultados indicam que PROMEP elevou significativamente o perfil, desempenho acadêmico e organização do corpo docente em tempo integral das UPES, mas também que, até 2013, o programa ainda não tinha sido capaz de cumprir as metas quantitativas que se deveria atingir para final de 2008. O estudo sugere que essa falha em atingir os objetivos iniciais foi principalmente devido ao fato de que muitas UPES cometeram ou autorizaram a violação dos regulamentos em matéria de recrutamento, retenção e promoção de professores e o fato de que PROMEP não estabeleceu medidas drásticas para parar essas violações, incluindo a assinatura de acordos legais que incluam sanções por violações das UPES

    Weight distribution of cyclic codes defined by quadratic forms and related curves

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    We consider cyclic codes CL associated to quadratic trace forms inm variables (Formula Presented) determined by a family L of q-linearized polynomials R over Fqm, and three related codes CL,0, CL,1, and CL,2. We describe the spectra for all these codes when L is an even rank family, in terms of the distribution of ranks of the forms QR in the family L, and we also computethe complete weight enumerator for CL. In particular, considering the family L = ‹xql›, with l fixed in N, we give the weight distribution of four parametrized families of cyclic codes Cl, Cl,0,Cl,1, and Cl,2 over Fq with zeros(Formula Presented) respectively,where q = ps with p prime, α is a generator of F*qm, and m/(m,l)is even. Finally, we give simple necessary and sufficient conditions for Artin–Schreier curves yp−y = xR(x)+βx, p prime, associated to polynomials R ∈ L to be optimal. We then obtain several maximal and minimal such curves inthe case (Formula Presented).Fil: Podesta, Ricardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Videla Guzman, Denis Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin

    The weight distribution of irreducible cyclic codes associated with decomposable generalized Paley graphs

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    We use known characterizations of generalized Paley graphs which areCartesian decomposable to explicitly compute the spectra of the corresponding associated irreducible cyclic codes. As applications, we give reduction formulas forthe number of rational points in Artin-Schreier curves defined over extension fields and to the computation of Gaussian periods.Fil: Podesta, Ricardo Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; ArgentinaFil: Videla Guzman, Denis Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Centro de Investigación y Estudios de Matemática. Universidad Nacional de Córdoba. Centro de Investigación y Estudios de Matemática; Argentina. Universidad Nacional de Córdoba. Facultad de Matemática, Astronomía y Física; Argentin

    A ringed pole-on outflow from DO Tauri revealed by ALMA

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    We present new ALMA Band 6 observations including the CO (2-1) line and 1.3 mmcontinuum emission from the surroundings of the young stellar object DO Tauri. TheALMA CO molecular data show three different series of rings at different radial ve-locities. These rings have radii around 220 au and 800 au. We make individual fits tothe rings and note that their centers are aligned with DO Tauri and its optical high-velocity jet. In addition, we notice that the velocity of these structures increases withthe separation from the young star. We discuss the data under the hypothesis that therings represent velocity cuts through three outflowing shells that are possibly drivenby a wide-angle wind, dragging the environment material along a direction close to theline of sight (i= 19◦). We estimate the dynamical ages, the mass, the momentum andthe energy of each individual outflow shell and those of the whole outflow. The resultsare in agreement with those found in outflows from Class II sources. We make a roughestimate for the size of the jet/wind launching region, which needs to be of.15 au.We report the physical characteristics of DO Tauri?s disk continuum emission (almostface-on and with a projected major axis in the north-south direction) and its velocitygradient orientation (north-south), indicative of disk rotation for a 1-2 Mcentral star.Finally we show an HST [SII] image of the optical jet and report a measurement of itsorientation in the plane of the sky.Fil: Fernandez Lopez, Manuel. 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: Zapata Gonzalez, Luis Alberto. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Rodríguez, Luis F.. Universidad Nacional Autonoma de Mexico. Instituto de Astronomia; MéxicoFil: Vazzano, María Mercedes. 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: Guzman, Andrés E.. National Astronomical Observatory Of Japan; JapónFil: López, Rosario. Universidad Autónoma de Barcelona. Facultad de Física. Departamento Astronomía y Meteorología; Españ

    Soil Pathogen Fate and Transport: Biopores Facilitating Escherichia Coli Transport

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