6,130 research outputs found

    Spatially resolved physical and chemical properties of the planetary nebula NGC 3242

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    Optical integral-field spectroscopy was used to investigate the planetary nebula NGC 3242. We analysed the main morphological components of this source, including its knots, but not the halo. In addition to revealing the properties ofthe physical and chemical nature of this nebula, we also provided reliable spatially resolved constraints that can be used for future photoionisation modelling of the nebula. The latter is ultimately necessary to obtain a fully self-consistent 3D picture of the physical and chemical properties of the object. The observations were obtained with the VIMOS instrument attached to VLT-UT3. Maps and values for specific morphological zones for the detected emission-lines were obtained and analysed with routines developed by the authors to derive physical and chemical conditions of the ionised gas in a 2D fashion. We obtained spatially resolved maps and mean values of the electron densities, temperatures, and chemical abundances, for specific morphological structures in NGC 3242. These results show the pixel-to-pixel variations of the the small- and large-scale structures of the source. These diagnostic maps provide information free from the biases introduced by traditional single long-slit observations. In general, our results are consistent with a uniform abundance distribution for the object, whether we look at abundance maps or integrated fluxes from specified morphological structures. The results indicate that special care should be taken with the calibration of the data and that only data with extremely good signal-to-noise ratio and spectral coverage should be used to ensure the detection of possible spatial variations.Comment: 11 pages, 8 figures accepted for publication in Astronomy & Astrophysic

    Estado Confusional Agudo apĂłs Corticoterapia Inalada

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    Background: The connection between corticotherapy and neuropsychiatric symptoms is widely known, being one of the first questions we need to assess when presenting with first episode psychiatric symptoms or confusional state. Aims: To date, data on cases related to inhaled corticotherapy and neuropsychiatric effects is scarce. In this paper we describe a rare case in a young woman. Methods: The clinical case presented led us to try to understand the data published on the subject in order to discuss it in greater length. Results and Conclusions: We present and discuss a 27-year-old patient’s case, with no previous psychiatric disease, who was admitted to our Psychiatric ward after the onset of severe acute behavioural disturbance characterized by aggressiveness, visual and auditory hallucinatory activity, misidentification and altered conscience status. It was later found that seven days earlier she had been prescribed inhaled corticotherapy for a minor respiratory infection. A few days after corticotherapy withdrawal, the clinical symptoms improved significantly.info:eu-repo/semantics/publishedVersio

    Perceived parent and friend support for romantic relationships in emerging adults

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    Positive close relationships with immediate close network members are associated with healthy adjustment among emerging adults (EA). These influence the initiation and maintenance of romantic relationships. A cross-sectional study (N = 630) explored the role of perceived parental and friend support for the current romantic relationship in relationship quality among early EA (EEA; 18-21 years) and middle EA (MEA; 22-25 years) heterosexuals. Structural equation modeling results showed that in EEA, greater friend support was associated with greater commitment, satisfaction, and investments, and less quality of alternatives. Greater parental support was associated with greater commitment, satisfaction, and investments in MEA. This research advances literature by showing different associations between sources of social support and relationship quality in two EA age groups.info:eu-repo/semantics/acceptedVersio

    Semiclassical description of resonant tunneling

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    We derive a semiclassical formula for the tunneling current of electrons trapped in a potential well which can tunnel into and across a wide quantum well. The calculations idealize an experimental situation where a strong magnetic field tilted with respect to an electric field is used. The resulting semiclassical expression is written as the sum over special periodic orbits which hit both walls of the quantum well and are perpendicular to the first wall.Comment: LaTeX, 8 page

    Some boundary effects in quantum field theory

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    We have constructed a quantum field theory in a finite box, with periodic boundary conditions, using the hypothesis that particles living in a finite box are created and/or annihilated by the creation and/or annihilation operators, respectively, of a quantum harmonic oscillator on a circle. An expression for the effective coupling constant is obtained showing explicitly its dependence on the dimension of the box.Comment: 12 pages, Late

    Band inversion driven by electronic correlations at the (111) LaAlO3_3/SrTiO3_3 interface

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    Quantum confinement at complex oxide interfaces establishes an intricate hierarchy of the strongly correlated dd-orbitals which is widely recognized as a source of emergent physics. The most prominent example is the (001) LaAlO3_3/SrTiO3_3(LAO/STO) interface, which features a dome-shaped phase diagram of superconducting critical temperature and spin-orbit coupling (SOC) as a function of electrostatic doping, arising from a selective occupancy of t2gt_{2g} orbitals of different character. Here we study (111)-oriented LAO/STO interfaces - where the three t2gt_{2g} orbitals contribute equally to the sub-band states caused by confinement - and investigate the impact of this unique feature on electronic transport. We show that transport occurs through two sets of electron-like sub-bands, and the carrier density of one of the sets shows a non-monotonic dependence on the sample conductance. Using tight-binding modeling, we demonstrate that this behavior stems from a band inversion driven by on-site Coulomb interactions. The balanced contribution of all t2gt_{2g} orbitals to electronic transport is shown to result in strong SOC with reduced electrostatic modulation.Comment: 5 pages, 4 figures, (+ supplemental material

    Primary and secondary scintillation measurements in a xenon Gas Proportional Scintillation Counter

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    NEXT is a new experiment to search for neutrinoless double beta decay using a 100 kg radio-pure high-pressure gaseous xenon TPC. The detector requires excellent energy resolution, which can be achieved in a Xe TPC with electroluminescence readout. Hamamatsu R8520-06SEL photomultipliers are good candidates for the scintillation readout. The performance of this photomultiplier, used as VUV photosensor in a gas proportional scintillation counter, was investigated. Initial results for the detection of primary and secondary scintillation produced as a result of the interaction of 5.9 keV X-rays in gaseous xenon, at room temperature and at pressures up to 3 bar, are presented. An energy resolution of 8.0% was obtained for secondary scintillation produced by 5.9 keV X-rays. No significant variation of the primary scintillation was observed for different pressures (1, 2 and 3 bar) and for electric fields up to 0.8 V cm-1 torr-1 in the drift region, demonstrating negligible recombination luminescence. A primary scintillation yield of 81 \pm 7 photons was obtained for 5.9 keV X-rays, corresponding to a mean energy of 72 \pm 6 eV to produce a primary scintillation photon in xenon.Comment: 16 pages, 10 figures, accepted for publication in JINS

    Nonlinear Relativistic and Quantum Equations with a Common Type of Solution

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    Generalizations of the three main equations of quantum physics, namely, the Schr\"odinger, Klein-Gordon, and Dirac equations, are proposed. Nonlinear terms, characterized by exponents depending on an index qq, are considered in such a way that the standard linear equations are recovered in the limit q→1q \rightarrow 1. Interestingly, these equations present a common, soliton-like, travelling solution, which is written in terms of the qq-exponential function that naturally emerges within nonextensive statistical mechanics. In all cases, the well-known Einstein energy-momentum relation is preserved for arbitrary values of qq

    Differential equations with maximal monotone operators

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    The paper deals with multivalued differential equations in abstract spaces. Nonlocal conditions are assumed. The model includes an m-dissipative multioperator which generates an equicontinuous, not necessarily compact, semigroup. The regularity of the nonlinear term also depends on the Hausdorff measure of noncompactness. The existence of integral solutions is discussed, with a topological index argument. A transversality condition is required. The results are applied to a partial differential inclusion in a bounded domain in R n with nonlocal integral conditions. The model also includes an m-dissipative but not necessarily compact semigroup generated by a suitable subdifferential operator. (c) 2024 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY-NC-ND license (http:// creativecommons .org /licenses /by -nc -nd /4 .0/)
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