395 research outputs found

    Exact controllability of a second order integro-differential equation with a pressure term

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    This paper is concerned with the boundary exact controllability of the equation u′′−Δu−∫0tg(t−σ)Δu(σ)dσ=−∇pu''-\Delta u-\int_0^t g(t-\sigma)\Delta u(\sigma) d\sigma=-\nabla p where QQ is a finite cilinder Ω×]0,T[\Omega\times]0,T[, Ω\Omega is a bounded domain of RnR^n, u=(u1(x,t),…,un(x,t))u=(u_1(x,t),\ldots,u_n(x,t)), x=(x1,…,xn)x=(x_1,\ldots,x_n) are nn-dimensional vectors and pp denotes the pressure term. The result is obtained by applying HUM (Hilbert Uniqueness Method) due to J. L. Lions. The above equation is a simple model of dynamical elasticity equations for incompressible materials with memory

    Perspectivas de la teoría crítica al final de la Ilustración.

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    Qualitative aspects for the cubic nonlinear Schrödinger equations with localized damping: Exponential and polynomial stabilization

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    AbstractResults of exponential/polynomial decay rates of the energy in L2-level, related to the cubic nonlinear Schrödinger equation with localized damping posed on the whole real line, will be established in this paper. We use Kato's theory and a priori estimates to obtain the result of global well-posedness and we determine exponential/polynomial stabilization combining the ideas of unique continuation due to Zhang, semigroup property and Komornik's approach

    Sistema de análisis de validez de las declaraciones (protocolo SVA) en un caso de abuso sexuales entre menores. Descripción de criterios y su aplicación

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    El SVA (Statement Validity Assessment) se aplica con frecuencia para la valoración de la credibilidad del testimonio en menores víctimas de abusos sexuales. Constituye una herram ienta validada en el ámbito de la psicología forense, pero no está exenta de subjetividad. El rigor metodológico en la aplicación del protocolo es imprescindible para que las conclusiones obtenidas t engan alguna validez en el procedimiento. En un caso de d enuncia de abusos sexuales entre menores se aportó al procedimiento un informe psicológico forense que analizaba la credibilidad del testimonio tras aplicar el protocolo SVA. Se discute la metodología apl icada y la argumentación del informe, y, por tanto, la validez de las conclusiones obtenidas en el informe pericial presentadoThe SVA (Statement Validity Assessment) is often applied to the assessment of the credibilit y of testimony in child victims of sexual abuse. It is a validated tool in the field of forensic psychology, but is somewhat subjective. The methodol ogical rigor in the application of the protocol is essential for the conclusions have any validity in the p roceeding. In case of a complaint of sexual abuse among children a forensic psychological report analyzing the credibility of the testimony after applying the SVA protocol is presented to the court. It discusses the methodology and therefore the validity of the conclusions of the expert report submitted

    Presence of banned chlorinated pollutants in sediments of the Northern Iberian Coast

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    Polychlorinated biphenyls (PCBs) are industrial chemical compounds that were banned in the mid-1970s owing to concerns about their toxicity, persistence and potential to bioaccumulate in the environment. However, despite European and global action, releases continue through diffuse emissions to air and water and PCBs concentrations are still detected in environmental matrices. In the framework of the Regional Sea Conventions such as OSPAR or Barcelona Convention, it is proposed to monitor the concentrations of pollutants that include, at least, the following PCBs: CB 28, 52, 101, 118, 138, 153 and 180. A control of the described PCBs presence was performed in a set of more than 70 surficial marine sediment samples distributed in the Gulf of Biscay/Atlantic coastal area. The analysis includes an accelerated solvent extraction step (ASE) followed by detection in a gas chromatography coupled to ECD detector. The analysis was under QA/QC to guarantee the quality of the results. The results indicate a detectable presence of PCBs pointing out higher concentration in eastern stations. Background Assessment Concentration (BACs) and Environmental Assessment Criteria (EAC) are assessment criteria that in place for polychlorinated biphenyls (PCBs) in sediment and they were used to evaluate the concentrations found. Most of the sediments have concentrations close to or even smaller than the BACs but in some specific sediments the concentration of some of the PCBs exceeds the EAC indicating possible toxic effects

    Influence of microwave oven calcination on the pozzolanicity of sugar cane bagasse ashes (SCBA) from the cogeneration industry

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    [EN] This study evaluates the effects of microwave oven calcining conditions on the pozzolanicity of sugar cane bagasse ashes (SCBA) generated by the electric power cogeneration industry. The calcining temperatures varied between 600 ºC and 800 ºC, and the permanence times were 60 min in an electric oven and 30, 45 and 60 min in a microwave oven. To evaluate the behaviour of the ashes according to different calcining conditions, we carried out the following analyses: granulometric distribution (laser diffraction), oxide percentages (XRF), loss on ignition (LOI), powder X-ray diffraction (XRD), pozzolanic reactivity, determination of amorphous silica content and thermogravimetry of hydrated lime pastes (DTG). The results show that SCBA calcination in a microwave oven results in ashes with greater pozzolanic reactivity and a significantly more efficient burning process than in an electric oven.The authors would like to thank the CNPq-Brazil (Project: 200133/2017-9) for financial support.Rossignolo, J.; Borrachero Rosado, MV.; Soriano Martinez, L.; Paya Bernabeu, JJ. (2018). Influence of microwave oven calcination on the pozzolanicity of sugar cane bagasse ashes (SCBA) from the cogeneration industry. Construction and Building Materials. 187:892-902. https://doi.org/10.1016/j.conbuildmat.2018.08.016S89290218

    Reading-related Cognitive Deficits in Spanish Developmental Dyslexia

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    AbstractSpanish-speaking children learn to read words written in a relatively transparent orthography. Variations in orthographic transparency may shape the manifestation of reading difficulties. This study was intended to help clarify the nature of developmental dyslexia in Spanish. Developmentally Dyslexic children (DD) were compared to a chronological age-matched control group (CA). Measures included rapid automated naming, verbal working memory, phonological short-term memory, and phonemic awareness. Results demonstrated that developmental dyslexics show reading-related cognitive deficits in areas such as naming speed, verbal working memory, phonological short-term memory, and phonemic awareness. Our results are consistent with studies conducted in the Spanish language and in other transparent orthographies
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