193 research outputs found

    Test Procedures for Characterizing, Evaluating, and Managing Separator Materials used in Secondary Alkaline Batteries

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    Secondary alkaline batteries, such as nickel-cadmium and silver-zinc, are commonly used for aerospace applications. The uniform evaluation and comparison of separator properties for these systems is dependent upon the measurement techniques. This manual presents a series of standard test procedures that can be used to evaluate, compare, and select separator materials for use in alkaline batteries. Detailed test procedures evaluating the following characteristics are included in this manual: physical measurements of thickness and area weight, dimensional stability measurements, electrolyte retention, resistivity, permeability as measured via bubble pressure, surface evaluation via SEM, chemical stability, and tensile strength

    How should we ‘care’ for LGBT+ students within higher education?

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    This article draws on a recent U.K. research project about lesbian, gay, bisexual and trans (LGBT+) perspectives on university to examine the implications for pastoral care and other service provision on campus. In a departure from previous scholarship that has tended to understand LGBT+ students as ‘vulnerable’ and/or needing ‘support’, it argues that university spaces should be (re)framed in a way that moves beyond (only) personal or individual ‘care’. The article outlines some of the issues that LGBT+ students may face under the following headings: Curriculum and course content; Discrimination, prejudice and bullying; Facilities and service provision on campus; A continuum of experiences. Following these, a final section draws some conclusions and implications for practice in higher education

    A flexible luminescent probe to monitor fast ion losses at the edge of the TJ-II stellarator

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    A mobile luminescent probe has been developed to detect fast ion losses and suprathermal ions escaping from the plasma of the TJ-II stellarator device. The priorities for its design have been flexibility for probe positioning, ease of maintenance, and detector sensitivity. It employs a coherent fiber bundle to relay, to the outside of the vacuum chamber, ionoluminescence images produced by the ions that impinge, after entering the detector head through a pinhole aperture, onto a screen of luminescent material. Ionoluminescence light detection is accomplished by a charge-coupled device camera and by a photomultiplier, both of which are optically coupled to the in-vacuum fiber bundle head by means of a standard optical setup. A detailed description of the detector, and the first results obtained when operated close to the plasma edge, are reported.Ministerio de Educación y Ciencia FTN 2003-0905, ENE2007-6500

    Systolic ventricular filling

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    The evidence of the ventricular myocardial band (VMB) has revealed unavoidable coherence and mutual coupling of form and function in the ventricular myocardium, making it possible to understand the principles governing electrical, mechanical and energetical events within the human heart. From the earliest Erasistratus' observations, principal mechanisms responsible for the ventricular filling have still remained obscured. Contemporary experimental and clinical investigations unequivocally support the attitude that only powerful suction force, developed by the normal ventricles, would be able to produce an efficient filling of the ventricular cavities. The true origin and the precise time frame for generating such force are still controversial. Elastic recoil and muscular contraction were the most commonly mentioned, but yet, still not clearly explained mechanisms involved in the ventricular suction. Classical concepts about timing of successive mechanical events during the cardiac cycle, also do not offer understandable insight into the mechanism of the ventricular filling. The net result is the current state of insufficient knowledge of systolic and particularly diastolic function of normal and diseased heart. Here we summarize experimental evidence and theoretical backgrounds, which could be useful in understanding the phenomenon of the ventricular filling. Anatomy of the VMB, and recent proofs for its segmental electrical and mechanical activation, undoubtedly indicates that ventricular filling is the consequence of an active muscular contraction. Contraction of the ascendent segment of the VMB, with simultaneous shortening and rectifying of its fibers, produces the paradoxical increase of the ventricular volume and lengthening of its long axis. Specific spatial arrangement of the ascendent segment fibers, their interaction with adjacent descendent segment fibers, elastic elements and intra-cavitary blood volume (hemoskeleton), explain the physical principles involved in this action. This contraction occurs during the last part of classical systole and the first part of diastole. Therefore, the most important part of ventricular diastole (i.e. the rapid filling phase), in which it receives >70% of the stroke volume, belongs to the active muscular contraction of the ascendent segment. We hope that these facts will give rise to new understanding of the principal mechanisms involved in normal and abnormal diastolic heart functio

    Evaluación de factores de riesgo cardiovascular y manifestaciones neurológicas en mujeres con síndrome de Ehlers-Danlos

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    El Síndrome de Ehlers Danlos (SED) es una enfermedad poco frecuente y hereditaria del tejido conectivo. Esta entidad puede identificarse en la práctica médica por presentar afecciones en el sistema músculo esquelético, ocular y cardiovascular, pero sus complicaciones neurológicas son poco estudiadas y reportadas. Últimamente se hallaron en Argentina casos de SED con trombofilia asociada por déficit de MTHFR. El objetivo de este trabajo es describir el riesgo cardiovascular en mujeres con SED y relatar posibles manifestaciones cerebrovasculares y sus antecedentes familiares de ACV.Facultad de Ciencias Médica

    Evaluación de factores de riesgo cardiovascular y manifestaciones neurológicas en mujeres con síndrome de Ehlers-Danlos

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    El Síndrome de Ehlers Danlos (SED) es una enfermedad poco frecuente y hereditaria del tejido conectivo. Esta entidad puede identificarse en la práctica médica por presentar afecciones en el sistema músculo esquelético, ocular y cardiovascular, pero sus complicaciones neurológicas son poco estudiadas y reportadas. Últimamente se hallaron en Argentina casos de SED con trombofilia asociada por déficit de MTHFR. El objetivo de este trabajo es describir el riesgo cardiovascular en mujeres con SED y relatar posibles manifestaciones cerebrovasculares y sus antecedentes familiares de ACV.Facultad de Ciencias Médica

    Transient tracking of low and high-order eccentricity-related components in induction motors via TFD tools

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    [EN] The present work is focused on the diagnosis of mixed eccentricity faults in induction motors via the study of currents demanded by the machine. Unlike traditional methods, based on the analysis of stationary currents (Motor Current Signature Analysis (MCSA)), this work provides new findings regarding the diagnosis approach proposed by the authors in recent years, which is mainly focused on the fault diagnosis based on the analysis of transient quantities, such as startup or plug stopping currents (Transient Motor Current Signature Analysis (TMCSA)), using suitable time-frequency decomposition (TFD) tools. The main novelty of this work is to prove the usefulness of tracking the transient evolution of high-order eccentricity-related harmonics in order to diagnose the condition of the machine, complementing the information obtained with the low-order components, whose transient evolution was well characterised in previous works. Tracking of high-order eccentricity-related harmonics during the transient, through their associated patterns in the time-frequency plane, may significantly increase the reliability of the diagnosis, since the set of fault-related patterns arising after application of the corresponding TFD tool is very unlikely to be caused by other faults or phenomena. Although there are different TFD tools which could be suitable for the transient extraction of these harmonics, this paper makes use of a WignerVille distribution (WVD)-based algorithm in order to carry out the time-frequency decomposition of the startup current signal, since this is a tool showing an excellent trade-off between frequency resolution at both high and low frequencies. Several simulation results obtained with a finite element-based model and experimental results show the validity of this fault diagnosis approach under several faulty and operating conditions. Also, additional signals corresponding to the coexistence of the eccentricity and other non-fault related phenomena making difficult the diagnosis (fluctuating load torque) are included in the paper. Finally, a comparison with an alternative TFD tool the discrete wavelet transform (DWT) applied in previous papers, is also carried out in the contribution. The results are promising regarding the usefulness of the methodology for the reliable diagnosis of eccentricities and for their discrimination against other phenomena. © 2010 Elsevier Ltd.All rights reserved.This work was supported by the Spanish 'Ministerio de Educacion y Ciencia', in the framework of the 'Programa Nacional de proyectos de Investigacion Fundamental', project reference DP12008-06583/DPI.Climente Alarcón, V.; Antonino-Daviu, J.; Riera-Guasp, M.; Pons Llinares, J.; Roger-Folch, J.; Jover-Rodriguez, P.; Arkkio, A. (2011). Transient tracking of low and high-order eccentricity-related components in induction motors via TFD tools. Mechanical Systems and Signal Processing. 25(2):667-679. https://doi.org/10.1016/j.ymssp.2010.08.008S66767925

    Síndrome de Ehlers-Danlos y trasplantes de órganos

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    El Síndrome de Ehlers Danlos (SED) es una enfermedad rara, que afecta el colágeno. Existen pacientes con SED que fallecen prematuramente a causa de muerte súbita y complicaciones cardiovasculares como en el caso del tipo IV. Esto los convierte en potenciales donantes de órganos. También pueden ser posibles receptores. El siguiente estudio tiene como objetivo relevar la información sobre eventos postquirúrgicos en personas con SED y antecedentes de trasplantes de órganos en estos pacientes tanto donantes como receptores.Facultad de Ciencias Médica

    Síndrome de Ehlers-Danlos y trasplantes de órganos

    Get PDF
    El Síndrome de Ehlers Danlos (SED) es una enfermedad rara, que afecta el colágeno. Existen pacientes con SED que fallecen prematuramente a causa de muerte súbita y complicaciones cardiovasculares como en el caso del tipo IV. Esto los convierte en potenciales donantes de órganos. También pueden ser posibles receptores. El siguiente estudio tiene como objetivo relevar la información sobre eventos postquirúrgicos en personas con SED y antecedentes de trasplantes de órganos en estos pacientes tanto donantes como receptores.Facultad de Ciencias Médica

    Ionoluminescent response of several phosphor screens to keV ions of different masses

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    We have characterized the ionoluminescent response of several phosphor powder materials when irradiated with ions of different masses H+ ,He+ ,Ar+ accelerated to keV energies. In particular, we have determined the absolute luminosity in terms of the number of photons per incident ion emitted by luminescent screens of Y2O2S:Tb P45, Y3Al5O12 :Ce P46, Y2SiO5 :Ce P47, Y2O3 :Eu P56, and SrGa2S4 :Eu TG-green. Their ionoluminescence has been studied as a function of ion beam energy and current and ion fluency. The energy trend and mass dependence of selected experimental results are compared relative to stopping and range of ions in matter SRIM code predictions.Ministerio de Educación y Ciencia FTN2003-090
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