1,721,178 research outputs found
FROM QGIS TO PYTHON: COMPARISON OF FREE AND OPEN TOOLS FOR STATISTICAL ANALYSIS OF CULTURAL HERITAGE AND DATA REPRESENTATION
Full text linkThe onset of the Covid pandemic in 2020 changed the approach to work, research, and study. This period has been a wake-up call for public administrations, the private sector, and the academic community, to digitise their data. In Italy, digital and information technologies for the protection and enhancement of cultural heritage, which were an imperative for more than a decade, have been accelerated. This paper aims to collect and to process openly available data on patrimony from OpenStreetMap and the Lombardian Geoportal. The study is divided into two phases: a simple statistical analysis of cultural heritage in Monza is obtained, and the results are presented graphically. Firstly, built-in tools and Python Console of QGIS are evaluated, to filter attributes and add geometrical values to the downloaded material. Secondly, plug-in DataPlotly and an online coding application named Replit are assessed. The results are presented and compared in terms of their flexibility, quality of visual representation, customisation, and simplicity of use. Tools developed through and for QGIS are easy to use and available to everyone. Additionally, coding applications can be integrated for more refined results. This approach fosters interdisciplinarity, bridges the gap between professionals and non-expert users of GIS, and opens a range of opportunities for future collaborations. The citizen, as a mapper, can be involved in the administrative decision-making process, contributing with data collected in situ. Collaboration between these two sides can potentially produce the better for evaluating the contemporary built environment and its undividable part of cultural heritage
Kinetic vortex chain solution in the drift-wave plasma regime
No full textA fully nonlinear Bernstein-Greene-Kruskal stationary solutionis found in the form of a quasi-three-dimensional chain of electron holes coupled to hydrodynamic vortices. This new coherent structure is enabled by the trapping and depletion of resonant particles, and the cyclotron dissipation of the singular current sheets. It is expected to play an important role in the collisionless magnetic field line reconnection in the drift-wave plasma regime, where it represents a plausible saturated state
Two-dimensional electron-magnetohydrodynamic nonlinear structures
No full textTwo-dimensional coherent electromagnetic structures involving the dynamics of the electron population in a quasineutral plasma with immobile ions are described. These structures consist of small scale magnetic vortices that propagate at a constant velocity. The dispersion relations of dipolar and tripolar vortices and of dipolar vortices and of vortex chains are given. The magnetic field of these vortices is three-dimensional. In addition, stationary quadrupolar vortices are described that are formed in the neighborhood of an X-point of the background configuration. (C) 2000 American Institute of Physics. [S1070-664X(00)01303-3]
Coherent nonlinear electromagnetic drift-mode structures
No full textThe nonlinear dynamics of an inhomogeneous plasma with hot electrons and cold ions, in the frequency range below the ion cyclotron and magnetosonic frequencies, is studied in the presence of magnetic shear. Both the finite electron mass and electron stress-tenser effects are accounted for, permiting arbitrary parallel phase velocities. A class of nonlinear travelling solutions is found, which are fully determined by the boundary conditions in the infinity, even on closed nonlinear characteristics. For the typical tokamak scaling beta < (L-n/L-3)(2), two different regimes are distinguished. In the shear Alfven regime, beta much less than m(e)/m(i), the solution has the form of a complex vortex chain, possessing both the magnetic and flow components, supported by a self-organized localized plasma flow and poloidal field. In the drift-wave regime, m(e)/m(i) much less than beta much less than 1, the solution is a nonlinear electromagnetic drift wave, whose amplitude is determined by its wavelength and the angle of propagation
Bernstein-Greene-Kruskal chain of drift-tearing vortices
No full textCollisionless magnetic reconnection in the driftwave plasma regime, rho(s,i)much greater than d(e), is studied using a drift-kinetic description of electrons and fluid ions. A fully nonlinear Bernstein-Greene-Kruskal (BGK) stationary solution is constructed which has the form of a quasi-three-dimensional chain of electron holes coupled to hydrodynamic vortices. This stationary structure is obtained by setting up a plateau in the electron distribution function, followed by the trapping and consecutive depletion of resonant particles, and by the removal of the singular current layers by their short-circuiting via electron gyrations. (C) 2000 American Institute of Physics. [S1070-664X(00)04902-8]
Effects of the parallel electron dynamics and finite ion temperature on the plasma blob propagation in the scrape-off layer
No full textA new three-dimensional model for the warm-ion turbulence at the tokamak edge plasma and in the scrape-off layer is proposed, and used to study the dynamics of plasma blobs in the scrape-off layer. The model is based on the nonlinear interchange mode, coupled with the nonlinear resistive drift mode, in the presence of the magnetic curvature drive, the density inhomogeneity, the electron dynamics along the open magnetic field lines, and the electron-ion and electron-neutral collisions. Within the present model, the effect of the sheath resistivity decreases with the distance from the wall, resulting in the bending and the break up of the plasma blob structure. Numerical solutions exhibit the coupling of interchange modes with nonlinear drift modes, causing the collapse of the blob in the lateral direction, followed by a clockwise rotation and radial propagation. The symmetry breaking, caused both by the parallel resistivity and the finite ion temperature, introduces a poloidal component in the plasma blob propagation, while the overall stability properties and the speed are not affected qualitatively
Magnetized electron-whistler holes
No full textCoherent magnetic structures comprising a magnetic vortex and an electron hole have been shown to be created by a Weibel-type, anisotropy driven instability. These structures arise from the electric and magnetic trapping of resonant electrons in the growing fields of the instability. The results of two dimensional Vlasov simulations of the nonlinear development of the instability are compared with a novel analytical model of a stationary propagating phase space structure which includes the depletion of the trapped electrons corresponding to the electron holes. (C) 2002 Elsevier Science B.V. All rights reserved
Tripolar shear-Alfven vortex structures
No full textNonlinear structures in the form of coherent tripolar vortices, associated with shear-Alfven perturbations in the presence of both magnetic and velocity shears, are studied analytically
DRAWINGS FOR THE REUSE OF NINETEENTH CENTURY GREENHOUSES IN THE GARDEN OF VILLA CICOGNA MOZZONI
Full text linkThe nineteenth-century greenhouses in the garden of Villa Cicogna Mozzoni are abandoned and dilapidated. Three greenhouses investigated for the research named A, B and C are positioned one above the other on the hill of the garden. They are historical examples of iron and glass structures with masonry walls leaning against the ground. They have undergone numerous modifications over time, as evidenced by archival documents. To create a preservation project for their reuse, bibliographical research was first collected. Secondly, direct and indirect surveys were carried out. The technical drawings were produced on a 1:50 scale using point clouds, orthophotos, sketches and direct measurements. Given the nature of the glass material of which these buildings are predominantly made, it was necessary to process the data obtained with the laser scanner and clean created noise points. Seemingly simple structures, greenhouses are complex buildings that require careful studies of humidity, temperature, irrigation, light and materials. For the presentation of different systems in the greenhouses, color-coded thematical drawings were created. Detailed drawings on a 1:20 scale examine the iron fixtures and manual mechanical system of the windows. Other characteristics were represented in the drawings, such as internal and external movements and communications between greenhouses. The survey and documentation were done to serve for the reuse project which aims to bring back the shine to these greenhouses so that they can be revitalized for botanical and educational activities
Perpendicular electron trapping associated with nonlinear whistlers
No full textKinetic effects leading to the particle trapping are studied in a magnetized, inhomogeneous plasma configuration within the framework of the gyrokinetic theory in the frequency and spatial scale range that corresponds to the whistler waves. This treatment accounts for finite electron Larmor radius and polarization effects. A coherent nonlinear structure is found, which is identified as a magnetic vortex coupled with an electron hole. This novel electron hole is characterized by a strong magnetic field, and has a typical perpendicular size somewhat shorter than the electron collisionless skin depth. Electrons are trapped in the perpendicular direction by the combination of the electrostatic field, arising from the charge separation, and of the Lorentz force resulting from the propagation of the structure relative to the perturbed magnetic field lines. The trapping effects are restricted to the region at the center of the vortex. The size of this region is related to the electron Larmor-radius and to the Debye length. (C) 2001 American Institute of Physics
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