1,303 research outputs found

    How different Fermi surface maps emerge in photoemission from Bi2212

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    We report angle-resolved photoemission spectra (ARPES) from the Fermi energy (EFE_F) over a large area of the (kx,kyk_x,k_y) plane using 21.2 eV and 32 eV photons in two distinct polarizations from an optimally doped single crystal of Bi2_2Sr2_2CaCu2_2O8+δ_{8+\delta} (Bi2212), together with extensive first-principles simulations of the ARPES intensities. The results display a wide-ranging level of accord between theory and experiment and clarify how myriad Fermi surface (FS) maps emerge in ARPES under various experimental conditions. The energy and polarization dependences of the ARPES matrix element help disentangle primary contributions to the spectrum due to the pristine lattice from those arising from modulations of the underlying tetragonal symmetry and provide a route for separating closely placed FS sheets in low dimensional materials.Comment: submitted to PR

    Fermi surface and electronic structure of Pb/Ge(111)

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    The electronic structure of Pb/Ge(111) has been probed along the temperature-induced phase transition ct -root 3X root 3R30 degrees double right arrow 3 X 3 using angle-resolved photoemission. The alpha-root 3X root 3R30 degrees phase is metallic due to the existence of a half-filled, dispersing surface band. The 3 X 3 phase is characterized by the appearance of an additional surface band with 3 X 3 periodicity, whose role in the phase transition is discussed. The Fermi-surface topology of the alpha-root 3X root 3R30 degrees phase has been probed using angle-resolved photoemission. Its shape is undulated, and it resembles strongly the theoretical prediction, with a Fermi momentum of 0.31 Angstrom(-1) along directions and 0.40 Angstrom(-1) along directions. These values were determined from different experimental methods, and agree with the values needed for a perfect 3 X 3 nesting. However, the Fermi surface exhibits no large flat areas suitable for electronic nesting

    A high-resolution fuel type mapping procedure based on satellite imagery and neural networks: Updating fuel maps for wildfire simulators

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    A major limitation in the simulation of forest fires involves the proper characterization of the surface vegetation over the study area, based on land cover maps. Unfortunately, these maps may be outdated, with areas where vegetation is either not documented or inaccurately portrayed. These limitations may impair the predictions of wildfire simulators or the design of risk maps and prevention plans. This study proposes a complete procedure for fuel type classification using satellite imagery and fully-connected neural networks. Specifically, our work is based on pixel- based processing cells, generating high-resolution maps. The field study is located in the Northeast of Castilla y Leo ́n, a central Spanish region, and the Rothermel criteria was followed for the fuel classification. The results record an accuracy of close to 78% on the test sets for the two studied settings, improving on the results reported in previous studies and ratifying the robustness of our approach. Additionally, the confusion matrix analysis and the per-class statistics computed confirm good reliability for all fuel types in a cross-validation framework. The predicted maps can be used on wildfire simulators through GIS tools.BERC 2022–2025 PID2019-107685RB-I00 European Regional Development Fund (ERDF) and the Department of Education of the regional government, the Junta of Castilla y Leo ́n, (Grant contract SA089P20); the European Union’s Horizon 2020 – Research and Innovation Framework Program under Grant agreement ID 101036926

    Leveraging Insights from Unique Artifacts for Creating Sustainable Products

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    Sustainablemanufacturingpursuestheachievementofeconomic,environmental, and societal benefits by promoting the long-term use of materials, products, and components within a circular economy. The analysis of one-of-a-kind classical products reveal some designs that exhibit a creative combination of parts from a variety of industrial sectors. For example, Italian designers behind some innovative artifacts have managed to integrate components from different sources into attractive and emotional-oriented objects that are revered to this day. The present work aims to combine 6R-based sustainable manufacturing with insights gained from some classical products of Italian design characterized by simplicity and decontextualization of common objects. This manuscript presents the design process for leveraging concepts embodied in some unique artifacts from the Italian design movement to inspire the realization of sustainable products. A commercial household item was redesigned to demonstrate the application of the approach by utilizing end-of-life items collected from municipal solid waste. The potential benefits of the triple bottom line approach associated with leveraging concepts, such as those from Italian design, to develop more sustainable products is also discussed

    A New Empirical Model for the Structural Analysis of Early-type Galaxies and a Critical Review of the Nuker Model

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    The Nuker law was designed to match the inner few (~3-10) arcseconds of predominantly nearby (< 30 Mpc) early-type galaxy light-profiles; it was never intended to describe an entire profile. The Sersic model, on the other hand, was developed to fit the entire profile; however, due to the presence of partially depleted galaxy cores, the Sersic model cannot always describe the very inner region. We have therefore developed a new empirical model consisting of an inner power-law, a transition region, and an outer Sersic model to connect the inner and outer structure of elliptical galaxies. Moreover, the stability of the Nuker model parameters are investigated. Surprisingly, none are found to be stable quantities; all are shown to vary systematically with a profile's fitted radial extent, and often by more than 100%. Considering elliptical galaxies spanning a range of 7.5 magnitudes, the central stellar density of the underlying host galaxy is observed to increase with galaxy luminosity until the onset of core formation, detected only in the brightest elliptical galaxies. We suggest that the so-called ``power-law'' galaxies may actually be described by the Sersic model over their entire radial range

    Antioxidant activity of monoterpenes and synergist antioxidant effect with BHT

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    Fil: Quiroga, Patricia R. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Quiroga, Patricia R. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Asensio, Claudia M. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Asensio, Claudia M. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Larrauri, Mariana. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Larrauri, Mariana. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Martin, María P. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Martin, María P. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Rivero, Cecilia G. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Rivero, Cecilia G. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Grosso, Nelson R. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Grosso, Nelson R. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Nepote, V. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Nepote, V. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Synthetic antioxidants are used in many foods. Their health safety is questioned. Monoterpenesobtained from essential oils have shown antioxidant activity. The objective of this study was to evaluate the preserving effect of monoterpenes: thymol, carvacrol, and sabineno hydrate acting as antioxidant additives.Fil: Quiroga, Patricia R. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Quiroga, Patricia R. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Asensio, Claudia M. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Asensio, Claudia M. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Larrauri, Mariana. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Larrauri, Mariana. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Martin, María P. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Martin, María P. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Rivero, Cecilia G. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Rivero, Cecilia G. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Grosso, Nelson R. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Grosso, Nelson R. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Fil: Nepote, V. Universidad Nacional de Córdoba. Facultad de Ciencias Agropecuarias; Argentina.Fil: Nepote, V. Universidad Nacional de Córdoba. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto Multidisciplinario de Biología Vegetal; Argentina.Alimentos y Bebida
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