English
Related papers

Related papers: New classification method of volcanic ash samples …

200 papers

This paper introduces ASTRA (Algorithm for Stochastic Topological RAnking), a new method for classifying galaxies into cosmic web structures -- voids, sheets, filaments, and knots -- specifically designed for large spectroscopic surveys.…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-29 Jaime E. Forero-Romero , Alejandro Palomino , Felipe Leonardo Gómez-Cortés , Xiao-Dong Li

In this paper, we present a new method to select the faint, background galaxies used to derive the mass of galaxy clusters by weak lensing. The method is based on the simultaneous analysis of the shear signal, that should be consistent with…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-23 I. Formicola , M. Radovich , M. Meneghetti , P. Mazzotta , A. Grado , C. Giocoli

We introduce an accurate, self-contained and automatic atom based numerical algorithm to characterize grain distributions in two dimensional Phase Field Crystal simulations. Four input parameters must be set by the user and their effect is…

Materials Science · Physics 2018-11-29 Gabriel Martine La Boissoniere , Rustum Choksi

Volcanic eruptions emit ash that can be harmful to human health and cause damage to infrastructure, economic activities and the environment. The delimitation of ash clouds allows to know their behavior and dispersion, which helps in the…

Computer Vision and Pattern Recognition · Computer Science 2023-07-25 Christian Carrillo , Gissela Torres , Christian Mejia-Escobar

We present experimental phase functions of three types of millimeter-sized dust grains consisting of enstatite, quartz and volcanic material from Mount Etna, respectively. The three grains present similar sizes but different absorbing…

Astrophysics of Galaxies · Physics 2017-09-05 O. Muñoz , F. Moreno , F. Vargas-Martín , D. Guirado , J. Escobar-Cerezo , M. Min , J. W. Hovenier

We probe gravitational clustering in N-body simulations using geometrical descriptors sensitive to `connectedness': the genus curve, percolation and shape statistics. We find that both genus and percolation curves provide complementary…

Astrophysics · Physics 2007-05-23 V. Sahni

Oblique, low-velocity impacts onto extraterrestrial terrain are an inevitable occurrence during space exploration. We conduct two-dimensional discrete simulations to model such impacts into a bed of triangular grains. Finite element method…

Earth and Planetary Astrophysics · Physics 2022-06-29 Peter M. Miklavčič , Hesam Askari , Paul Sánchez , Alice C. Quillen , Esteban Wright

This paper proposes a simple, generic and robust method to extract the grains from experimental tridimensionnal images of granular materials obtained by X-ray tomography. This extraction has two steps: segmentation and splitting. For the…

Computer Vision and Pattern Recognition · Computer Science 2008-07-23 Vincent Tariel

For 3D geometries, we consider stones (modeled as convex polyhedra) subject to weathering with planar slices of random orientation and depth successively removing material, ultimately yielding smooth and round (i.e. spherical) shapes. An…

Statistical Mechanics · Physics 2020-03-10 D. J. Priour

A sample of Nobeyama flares was selected and analyzed using loop model for important flare parameters. The model for the flaring region consists of a three dimensional dipolar magnetic field, and spatial distributions of non-thermal…

Solar and Stellar Astrophysics · Physics 2015-06-16 Joaquim E. R. Costa , Paulo J. A. Simões , Tereza S. N. Pinto , Victor F. Melnikov

The volume of data that will be produced by the next generation of astrophysical instruments represents a significant opportunity for making unplanned and unexpected discoveries. Conversely, finding unexpected objects or phenomena within…

Instrumentation and Methods for Astrophysics · Physics 2019-09-11 Gary Segal , David Parkinson , Ray P. Norris , Jesse Swan

In this study we demonstrate for the first time that the unified Monte Carlo approach can be applied to model gas-grain chemistry in large reaction networks. Specifically, we build a time-dependent gas-grain chemical model of the…

Astrophysics · Physics 2011-02-11 A. I. Vasyunin , D. A. Semenov , D. S. Wiebe , Th. Henning

Information about the make-up of the galaxy arrives in the Solar system in many forms: photons of different energies, classically collected by ground- and space-based telescopes, neutral and charged atomic particles, and solid macroscopic…

Atomistic simulations have now established themselves as an indispensable tool in understanding deformation mechanisms of materials at the atomic scale. Large scale simulations are regularly used to study the behavior of polycrystalline…

Materials Science · Physics 2021-12-08 M. Vimal , S. Sandfeld , A. Prakash

Terrestrial laser scanning technology provides an efficient and accuracy solution for acquiring three-dimensional information of plants. The leaf-wood classification of plant point cloud data is a fundamental step for some forestry and…

Computer Vision and Pattern Recognition · Computer Science 2020-12-08 Zichu Liu , Qing Zhang , Pei Wang , Yaxin Li , Jingqian Sun

We critically examine the best lines of evidence for grain growth in protoplanetary disks, based on modelling of observed spectral energy distributions and images of T Tauri and Herbig Ae stars. The data are consistent with millimeter-sized…

Astrophysics · Physics 2007-05-23 E. I. Chiang

Aligned interstellar grains produce polarized extinction (observed at wavelengths from the far-ultraviolet to the mid-infrared), and polarized thermal emission (observed at far-infrared and submm wavelengths). The grains must be quite…

Astrophysics of Galaxies · Physics 2025-04-07 B. T. Draine

We present calculations of diffusion coefficients in grain boundaries in Yukawa crystals for astrophysics. Our methods follow from our recent work calculating diffusion coefficients in perfect body-centered cubic crystals. These diffusion…

Polarized continuum emission from aligned grains in disks around young stellar objects can be used to probe the magnetic field, radiation anisotropy, or drift between dust and gas, depending on whether the non-spherical grains are aligned…

Solar and Stellar Astrophysics · Physics 2020-04-09 Zhe-Yu Daniel Lin , Zhi-Yun Li , Haifeng Yang , Leslie Looney , Chin-Fei Lee , Ian Stephens , Shih-Ping Lai

We develop a Lagrangian stochastic model (LSM) of a volcanic plume in which the mean flow is provided by an integral plume model of the eruption column and fluctuations in the vertical velocity are modelled by a suitably constructed…

Geophysics · Physics 2021-04-07 Benjamin J. Devenish , Matteo Cerminara