582 research outputs found

    Catalogue of Apparent Diameters and Absolute Radii of Stars (CADARS) - Third Edition - Comments and Statistics

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    The Catalogue, available at the Centre de Donn\'ees Stellaires de Strasbourg, consists of 13573 records concerning the results obtained from different methods for 7778 stars, reported in the literature. The following data are listed for each star: identifications, apparent magnitude, spectral type, apparent diameter in arcsec, absolute radius in solar units, method of determination, reference, remarks. Comments and statistics obtained from CADARS are given.Comment: A&A, in pres

    Alternative characterization of the nematic transition in deposition of rods on two-dimensional lattices

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    We revisit the problem of excluded volume deposition of rigid rods of length k unit cells over square lattices. Two new features are introduced: (a) two new short-distance complementary order parameters, called Π and ς, are defined, calculated, and discussed to deal with the phases present as coverage increases; (b) the interpretation is now done beginning at the high-coverage ordered phase which allows us to interpret the low-coverage nematic phase as an ergodicity breakdown present only when k≥7. In addition the data analysis invokes both mutability (dynamical information theory method) and Shannon entropy (static distribution analysis) to further characterize the phases of the system. Moreover, mutability and Shannon entropy are compared, and we report the advantages and disadvantages they present for their use in this problem.Fil: Vogel, E. E.. Universidad de La Frontera; ChileFil: Saravia, G.. Universidad de la Frontera. Facultad de Ingeniería y Ciencias; ChileFil: Ramirez Pastor, Antonio Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; ArgentinaFil: Pasinetti, Pedro Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich". Universidad Nacional de San Luis. Facultad de Ciencias Físico Matemáticas y Naturales. Instituto de Física Aplicada "Dr. Jorge Andrés Zgrablich"; Argentin

    Monte Carlo-based 3D surface point cloud volume estimation by exploding local cubes faces

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    This article proposes a state-of-the-art algorithm for estimating the 3D volume enclosed in a surface point cloud via a modified extension of the Monte Carlo integration approach. The algorithm consists of a pre-processing of the surface point cloud, a sequential generation of points managed by an affiliation criterion, and the final computation of the volume. The pre-processing phase allows a spatial reorientation of the original point cloud, the evaluation of the homogeneity of its points distribution, and its enclosure inside a rectangular parallelepiped of known volume. The affiliation criterion using the explosion of cube faces is the core of the algorithm, handles the sequential generation of points, and proposes the effective extension of the traditional Monte Carlo method by introducing its applicability to the discrete domains. Finally, the final computation estimates the volume as a function of the total amount of generated points, the portion enclosed within the surface point cloud, and the parallelepiped volume. The developed method proves to be accurate with surface point clouds of both convex and concave solids reporting an average percentage error of less than 7 %. It also shows considerable versatility in handling clouds with sparse, homogeneous, and sometimes even missing points distributions. A performance analysis is presented by testing the algorithm on both surface point clouds obtained from meshes of virtual objects as well as from real objects reconstructed using reverse engineering techniques

    Critical behavior of repulsive linear kk-mers on triangular lattices

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    Monte Carlo (MC) simulations and finite-size scaling analysis have been carried out to study the critical behavior in a submonolayer two-dimensional gas of repulsive linear kk-mers on a triangular lattice at coverage k/(2k+1)k/(2k+1). A low-temperature ordered phase, characterized by a repetition of alternating files of adsorbed kk-mers separated by k+1k+1 adjacent empty sites, is separated from the disordered state by a order-disorder phase transition occurring at a finite critical temperature, TcT_c. The MC technique was combined with the recently reported Free Energy Minimization Criterion Approach (FEMCA), [F. Rom\'a et al., Phys. Rev. B, 68, 205407, (2003)], to predict the dependence of the critical temperature of the order-disorder transformation. The dependence on kk of the transition temperature, Tc(k)T_c(k), observed in MC is in qualitative agreement with FEMCA. In addition, an accurate determination of the critical exponents has been obtained for adsorbate sizes ranging between k=1k=1 and k=3k=3. For k>1k>1, the results reveal that the system does not belong to the universality class of the two-dimensional Potts model with q=3q=3 (k=1k=1, monomers). Based on symmetry concepts, we suggested that the behavior observed for k=1,2k=1, 2 and 3 could be generalized to include larger particle sizes (k2k \geq 2).Comment: 17 pages, 13 figure

    Surface phase transitions in one-dimensional channels arranged in a triangular cross-sectional structure: Theory and Monte Carlo simulations

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    Monte Carlo simulations and finite-size scaling analysis have been carried out to study the critical behavior in a submonolayer lattice-gas of interacting monomers adsorbed on one-dimensional channels arranged in a triangular cross-sectional structure. The model mimics a nanoporous environment, where each nanotube or unit cell is represented by a one-dimensional array. Two kinds of lateral interaction energies have been considered: 1)1) wLw_L, interaction energy between nearest-neighbor particles adsorbed along a single channel and 2)2) wTw_T, interaction energy between particles adsorbed across nearest-neighbor channels. For wL/wT=0w_L/w_T=0 and wT>0w_T > 0, successive planes are uncorrelated, the system is equivalent to the triangular lattice and the well-known (3×3)(\sqrt{3} \times \sqrt{3}) [(3×3)][(\sqrt{3} \times \sqrt{3})^*] ordered phase is found at low temperatures and a coverage, θ\theta, of 1/3 [2/3][2/3]. In the more general case (wL/wT0w_L/w_T \neq 0 and wT>0w_T > 0), a competition between interactions along a single channel and a transverse coupling between sites in neighboring channels allows to evolve to a three-dimensional adsorbed layer. Consequently, the (3×3)(\sqrt{3} \times \sqrt{3}) and (3×3)(\sqrt{3} \times \sqrt{3})^* structures "propagate" along the channels and new ordered phases appear in the adlayer. The Monte Carlo technique was combined with the recently reported Free Energy Minimization Criterion Approach (FEMCA), to predict the critical temperatures of the order-disorder transformation. The excellent qualitative agreement between simulated data and FEMCA results allow us to interpret the physical meaning of the mechanisms underlying the observed transitions.Comment: 24 pages, 6 figure

    Deep Learning in cucina: sviluppo e validazione di un sistema di riconoscimento di azioni basato su sensori RGBD

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    La presente memoria descrive i primi risultati raggiunti nell’ambito di un progetto di ricerca con la scuola bresciana di cucina Cast Alimenti. L’obiettivo del lavoro di ricerca è lo sviluppo di un sistema intelligente per il riconoscimento delle azioni svolte da un cuoco durante la preparazione di una ricetta. Cast Alimenti mira ad ottenere un prodotto da utilizzare durante la didattica che abbia un duplice scopo: da una parte si vuole riconoscere che operazione il cuoco docente sta effettuando, con che ingredienti e con quali utensili; dall’altra parte il sistema sarà in grado di effettuare la stessa operazione di riconoscimento con gli alunni della lezione, controllando se l’operazione pratica di cucina viene svolta nel modo migliore. In questa memoria vengono descritti i primi risultati raggiunti relativi al riconoscimento delle azioni del cuoco. Il riconoscimento delle azioni è stato effettuato e valutato confrontando due tra i migliori algoritmi di riconoscimento azioni basati su reti neurali ricorsive: il primo, denominato Human Pose Model and Temporal Modelling (HPM+TM), basato sull’analisi di immagini di profondità e il secondo, denominato Indipendetly Recurrent Neural Network (IndRNN), basato sulla misura di diversi keypoint individuati a partire da una skeletonization del soggetto ripreso

    Ozone tertiary treatment for pharmaceuticals and personal care products removal from municipal wastewater

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    An ozone pilot plant was installed at a conventional WWTP to evaluate the removal rate of emerging contaminants, drugs, and fragrances, as tertiary treatment. The filtered secondary effluent flow rate ranged between 1.3÷1.9 m3/h with a retention time of 10÷30 minutes and the plant operated with an ozone dose of 2- 4 mgO3/l. The results evidenced a high removal rate of 80-100% for most of the organic targeted compounds: Amisulpride, Azithromycin, Carbamazepine, Diclofenac, Clarithromycin and Ofloxacin. Lower removal rates from 20% to 80%, were observed for some substances e.g. Gabapentin Lactam, Galaxolidone, Irbesartan, Lamotrigine, and Tonalide. Advanced Oxidation Process (AOP) treatment with O3/H2O2, (0.5–1.0–2 molH2O2/molO3) allowed improved results for almost all these latter. In addition, ozone determined up to 42% removal of the absorbance at 254 nm and 20% of COD, wastewater disinfection, a decrease of the GC-MS chromatographic area, and no acute toxicity effect nor estrogenic and mutagen effects have been detected

    Near-infrared interferometric observation of the Herbig Ae star HD144432 with VLTI/AMBER

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    We study the sub-AU-scale circumstellar environment of the Herbig Ae star HD144432 with near-infrared (NIR) VLTI/AMBER observations to investigate the structure of its inner dust disk. The interferometric observations were carried out with the AMBER instrument in the H and K band. We interpret the measured H- and K-band visibilities, the near- and mid-infrared visibilities from the literature, and the SED of HD144432 by using geometric ring models and ring-shaped temperature-gradient disk models with power-law temperature distributions. We derived a K-band ring-fit radius of 0.17 \pm 0.01 AU and an H-band radius of 0.18 \pm 0.01 AU (for a distance of 145 pc). This measured K-band radius of \sim0.17 AU lies in the range between the dust sublimation radius of \sim0.13 AU (predicted for a dust sublimation temperature of 1500 K and gray dust) and the prediction of models including backwarming (\sim0.27 AU). We found that an additional extended halo component is required in both the geometric and temperature-gradient modeling. In the best temperature- gradient model, the disk consists of two components. The inner part of the disk is a thin ring with an inner radius of \sim0.21 AU, a temperature of \sim1600 K, and a ring thickness \sim0.02 AU. The outer part extends from \sim1 AU to \sim10 AU with an inner temperature of \sim400 K. We find that the disk is nearly face-on with an inclination angle of < 28 degree. Our temperature-gradient modeling suggests that the NIR excess is dominated by emission from a narrow, bright rim located at the dust sublimation radius, while an extended halo component contributes \sim6% to the total flux at 2 {\mu}m. The MIR model emission has a two-component structure with \sim20% flux from the inner ring and the rest from the outer part. This two-component structure suggests a disk gap, which is possibly caused by the shadow of a puffed-up inner rim.Comment: 7 pages, 5 figures, accepted by A&
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