12,763 research outputs found

    Memory effect in triglycine sulfate induced by a transverse electric field: specific heat measurement

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    The influence of a transverse electric field in the specific heat of triglycine sulphate (TGS) has been studied. The specific heat of TGS has been measured heating the sample from ferroelectric to paraelectric phase after prolonged transverse electric field (i.e. perpendicular to the ferroelectric axis). It is shown that the specific heat of TGS can remember the temperature TsT_s at which the transverse field was previously applied.Comment: ReVTeX4 Twocolumn 4 pages, 4 figure

    Deployment of Digital Video and Audio Over Electrical SCADA Networks

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    With the arrival of new hardware and software technologies, supervisory control and data acquisition human-machine interfaces (SCADA/HMI), usually text-based, can now benefit from the advantages the inclusion of multimedia information brings. However, due to the special requirements imposed by such systems, integrating audio and video data into the SCADA interfaces is not a trivial task. In this document we analyze those special characteristics and propose solutions so this integration is possible in power systems communication.Ministerio de Ciencia y Tecnología TIC2000-0367-P4-0

    The Integrated Renovation of High-Rise Hotels on the Spanish Mediterranean Coast

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    In terms of construction and energy efficiency, Spain has one of the highest indexes of obsolete buildings among the developed countries. In the case of high-rise hotel buildings, this problem is further added to by the low levels of safety in the case of fire. The development of tourism in the 1950s and 60s led to the construction of a large number of high-rise hotels with 30+ floors. Initially, they conformed to lax, undemanding regulations regarding fire resistance in their structural components, fire escape routes, protected staircases, and so on. The requirements of today’s regulations in this field, contained in the Basic SI Technical Building Code Document, often make the renovation of these buildings an impossible task. Installing specially protected staircases can entail traumatic modifications that are sometimes unviable due to structural conditions or economic considerations. Furthermore, the building’s energy efficiency and CO2 emissions do not correspond to environmentally-friendly practices. This paper examines the above questions with regard to the Hotel Tryp Gran Sol in Alicante, Spain. The hotel is 97 m high and has 31 floors. The integrated renovation of the hotel requires serious reflection upon the building’s global response to personal safety, its envelope components and its air conditioning. Architectural solutions and the building’s economic viability for future exploitation as an important element in the building’s life cycle assessment (LCA) are discussed

    Probabilistic Guarded P Systems, A New Formal Modelling Framework

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    Multienvironment P systems constitute a general, formal framework for modelling the dynamics of population biology, which consists of two main approaches: stochastic and probabilistic. The framework has been successfully used to model biologic systems at both micro (e.g. bacteria colony) and macro (e.g. real ecosystems) levels, respectively. In this paper, we extend the general framework in order to include a new case study related to P. Oleracea species. The extension is made by a new variant within the probabilistic approach, called Probabilistic Guarded P systems (in short, PGP systems). We provide a formal definition, a simulation algorithm to capture the dynamics, and a survey of the associated software.Ministerio de Economía y Competitividad TIN2012- 37434Junta de Andalucía P08-TIC-0420

    Experimental method to determine specific heat and transition enthalpy at a first order phase transition: fundamentals and application to a NiMnIn Heusler alloy

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    A new method that characterizes thermal properties during a first-order phase transition is described. The technique consists in exciting the sample by a series of constant frequency thermal pulses which one in every N pulses (N is a small number like four) being exceedingly large in amplitude. This pulse induces phase transformation which is inhibited during the following smaller pulses due to thermal hysteresis. That way the specific heat for a given mixture of phases can be determined. The results obtained are independent of experimental parameters like the rate and the amplitude of the pulses, unlike what happens in other calorimetric techniques. The method also provides the enthalpy excess by analyzing the energy balance between the dissipated heat and the heat flowing during each pulse of measurement. The protocol is tested to analyze the phase transitions of a Heusler alloy Ni 50.54 Mn 33.65 In 15.82 . The paramagnetic-ferromagnetic transition for the austenite phase is continuous and the specific heat shows a lambda anomaly. The martensitic phase transition shows a first-order character and the specific heat follows a step-like behaviour in contrast with previously reported large-peak anomalies.Comment: 15 pages, 5 figure

    AE Aurigae: first detection of non-thermal X-ray emission from a bow shock produced by a runaway star

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    Runaway stars produce shocks when passing through interstellar medium at supersonic velocities. Bow shocks have been detected in the mid-infrared for several high-mass runaway stars and in radio waves for one star. Theoretical models predict the production of high-energy photons by non-thermal radiative processes in a number sufficiently large to be detected in X-rays. To date, no stellar bow shock has been detected at such energies. We present the first detection of X-ray emission from a bow shock produced by a runaway star. The star is AE Aur, which was likely expelled from its birthplace by the encounter of two massive binary systems and now is passing through the dense nebula IC 405. The X-ray emission from the bow shock is detected at 30" to the northeast of the star, coinciding with an enhancement in the density of the nebula. From the analysis of the observed X-ray spectrum of the source and our theoretical emission model, we confirm that the X-ray emission is produced mainly by inverse Compton upscattering of infrared photons from dust in the shock front.Comment: Accepted for publication in the Astrophysical Journal with number ApJ, 757, L6. Four figure

    Onto-CC: a web server for identifying Gene Ontology conceptual clusters

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    The Gene Ontology (GO) vocabulary has been extensively explored to analyze the functions of coexpressed genes. However, despite its extended use in Biology and Medical Sciences, there are still high levels of uncertainty about which ontology (i.e. Molecular Process, Cellular Component or Molecular Function) should be used, and at which level of specificity. Moreover, the GO database can contain incomplete information resulting from human annotations, or highly influenced by the available knowledge about a specific branch in an ontology. In spite of these drawbacks, there is a trend to ignore these problems and even use GO terms to conduct searches of gene expression profiles (i.e. expression + GO) instead of more cautious approaches that just consider them as an independent source of validation (i.e. expression versus GO). Consequently, propagating the uncertainty and producing biased analysis of the required gene grouping hypotheses. We proposed a web tool, Onto-CC, as an automatic method specially suited for independent explanation/validation of gene grouping hypotheses (e.g. coexpressed genes) based on GO clusters (i.e. expression versus GO). Onto-CC approach reduces the uncertainty of the queries by identifying optimal conceptual clusters that combine terms from different ontologies simultaneously, as well as terms defined at different levels of specificity in the GO hierarchy. To do so, we implemented the EMO-CC methodology to find clusters in structural databases [GO Directed acyclic Graph (DAG) tree], inspired on Conceptual Clustering algorithms. This approach allows the management of optimal cluster sets as potential parallel hypotheses, guided by multiobjective/multimodal optimization techniques. Therefore, we can generate alternative and, still, optimal explanations of queries that can provide new insights for a given problem. Onto-CC has been successfully used to test different medical and biological hypotheses including the explanation and prediction of gene expression profiles resulting from the host response to injuries in the inflammatory problem. Onto-CC provides two versions: Ready2GO, a precalculated EMO-CC for several genomes and an Advanced Onto-CC for custom annotation files (http://gps-tools2.wustl.edu/onto-cc/index.html)

    Mujeres que son pareja de un varón infectado por el VIH: descripción de sus características y valoración del riesgo

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    ObjetivoDescribir las situaciones de riesgo y la prevalencia del virus de la inmunodeficiencia humana (VIH) en mujeres con pareja heterosexual infectada por el VIH.DiseñoEstudio descriptivo y transversal.EmplazamientoCentro ambulatorio de diagnóstico del VIH de Madrid.PacientesSe incluyó en el estudio a 229 mujeres atendidas por primera vez entre 1993 y 2002 por tener una pareja heterosexual estable diagnosticada de infección por el VIH, sin otra exposición de riesgo.Mediciones principalesInformación sociodemográfica, historial reproductivo, conducta sexual, datos clínicos y analíticos de ambos miembros de la pareja.ResultadosEl 66% de las parejas mantenían relaciones sexuales desde hacía más de un año. Las mujeres tenían menor edad media (29,6 años) que los varones. El 29% de las mujeres tenían hijos y el 5,2% estaban embarazadas. Entre los varones, el 82% se había inyectado drogas, pero sólo el 13% mantenía esta práctica. El 73% estaba diagnosticado de infección por el VIH desde hacía más de 6 meses, el 16% presentaba criterios de sida y el 35% recibía tratamiento antirretroviral. El 60% de los varones que conocían previamente su infección habían evitado sistemáticamente los coitos sin preservativo, frente al 33% de los que no se sabían infectados (p < 0,001). El 19% había tenido accidentes en el uso del preservativo. La seroprevalencia del VIH en las mujeres fue del 6,1% (intervalo de confianza del 95%, 3,5-10,3%).ConclusionesLa atención a las personas con VIH debe incluir la asistencia a la pareja sexual, ofreciendo información, apoyo psicológico, consejo preventivo y reproductivo, además del diagnóstico del VIH y de otras infecciones de transmisión sexual.ObjectiveTo describe the situations of risk and the prevalence of HIV in women with a heterosexual partner infected by HIV.DesignCross-sectional descriptive study.SettingOut-patient HIV diagnosis centre in Madrid.Patients229 women seen for the first time between 1993 and 2002 because they had a stable heterosexual partner diagnosed with HIV, and who were exposed to no other risk.Main measurementsSocial and personal details, reproduction history, sexual conduct, clinical, and analytic data of both partners.Results66% of couples had maintained sexual relations for over a year.Women were on average younger (29.6 years old) than the men. 29% of the women had children and 5.2% were pregnant. 82% of men had injected drugs, but only 13% still did. 73% had been diagnosed with HIV for over 6 months, 16% had AIDS criteria, and 35% were taking retroviral treatment. 60% of the men who knew of their infection had systematically avoided sex without condoms, against 33% of those who did not know they were infected (P<.001). 19% had had accidents in use of the condom.HIV seroprevalence in the women was 6.1% (95% CI, 3.5%-10.3%).ConclusionsHealth care of people with HIV must include care of their sexual partner, involving information, psychological support, preventive and reproductive advice, as well as diagnosis of HIV or other sexually transmitted diseases

    Non-linear classifiers applied to EEG analysis for epilepsy seizure detection

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    This work presents a novel approach for automatic epilepsy seizure detection based on EEG analysis that exploits the underlying non-linear nature of EEG data. In this paper, two main contributions are presented and validated: the use of non-linear classifiers through the so-called kernel trick and the proposal of a Bag-of-Words model for extracting a non-linear feature representation of the input data in an unsupervised manner. The performance of the resulting system is validated with public datasets, previously processed to remove artifacts or external disturbances, but also with private datasets recorded under realistic and non-ideal operating conditions. The use of public datasets caters for comparison purposes whereas the private one shows the performance of the system under realistic circumstances of noise, artifacts, and signals of different amplitudes. Moreover, the proposed solution has been compared to state-of-the-art works not only for pre-processed and public datasets but also with the private datasets. The mean F1-measure shows a 10% improvement over the second-best ranked method including cross-dataset experiments. The obtained results prove the robustness of the proposed solution to more realistic and variable conditions. (C) 2017 Elsevier Ltd. All rights reserved
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