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Related papers: Grain-size dynamics beneath mid-ocean ridges: Impl…

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Grain alignment theory suggests that grains should be aligned in circumstellar regions and the observational data available supports this conclusion. We discuss the alignment of grains via (1) magnetic relaxation, (2) mechanical processes,…

Astrophysics · Physics 2007-05-23 Lazarian A

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

Airless planetary bodies are covered by a dusty layer called regolith. The grain size of the regolith determines the temperature and the mechanical strength of the surface layers. Thus, knowledge of the grain size of planetary regolith…

Earth and Planetary Astrophysics · Physics 2015-06-12 Bastian Gundlach , Jürgen Blum

A systematic investigation is presented of grain boundaries and grain boundary networks in two dimensional flexible membranes with crystalline order. An isolated grain boundary undergoes a buckling transition at a critical value of the…

Condensed Matter · Physics 2009-10-22 Carlo Carraro , David R. Nelson

Widespread detection of amorphous and crystalline water (H${}_{2}$O) ice in the outer solar system bodies and the interstellar medium has been confirmed over the past decades. Radiative transfer models (RTMs) are used to estimate the grain…

Earth and Planetary Astrophysics · Physics 2023-03-29 A. Emran , V. F. Chevrier

Current transport in polysilicon is a complicated process with many factors to consider. The inhomogeneous nature of polysilicon with its differently shaped and sized grains is one such consideration. We have developed a method that…

Granular materials are known to separate by size under a variety of circumstances. Experiments presented here and elucidated by modeling and MD simulation document a new segregation mechanism, namely segregation by friction. The experiments…

Soft Condensed Matter · Physics 2009-11-07 L. Kondic , R. R. Hartley , S. G. K. Tennakoon , B. Painter , R. P. Behringer

Investigating the dust grain size and its dependence on substructures in protoplanetary disks is a crucial step in understanding the initial process of planet formation. Spectral indices derived from millimeter observations are used as a…

Earth and Planetary Astrophysics · Physics 2024-10-08 Dafa Li , Yao Liu , Hongchi Wang , Min Fang , Lei Wang

A continuum grain boundary model is developed that uses experimentally measured grain boundary energy data as a function of misorientation to simulate idealized grain boundary evolution in a 1-D grain array. The model uses a continuum…

Materials Science · Physics 2024-01-29 Syed Ansari , Amit Acharya , Alankar Alankar

The present article reports a method for the average grain size evaluation of superconducting nano-particles through their magnetic properties. The use of SQUID magnetometry to determine the average MgB2 particle size was investigated and…

This paper investigates the statistical behavior of two-dimensional grain microstructures during grain growth under anisotropic grain boundary characters. We employ the threshold-dynamics method, which allows for unparalleled computational…

Materials Science · Physics 2023-09-19 Jaekwang Kim , Nikhil Chandra Admal

Particle coarsening and grain growth take place to minimize the total interfacial energy. The classical mean-field treatments by Lifshitz, Slyozov, [1] Wagner [2] and Hillert [3] predicted cubic growth law under bulk-diffusion controlled…

Materials Science · Physics 2017-08-24 Yanhao Dong , Jian Han

In light of the race towards macroscale superlubricity of graphitic contacts, the effect of grain boundaries on their frictional properties becomes of central importance. Here, we elucidate the unique frictional mechanisms characterizing…

Mesoscale and Nanoscale Physics · Physics 2020-08-04 Xiang Gao , Wengen Ouyang , Oded Hod , Michael Urbakh

The evolution of two grains, which lie on a substrate and are in contact with each other, can be roughly described by a model in which the exterior surfaces of the grains evolve by surface diffusion and the grain boundary, namely the…

Analysis of PDEs · Mathematics 2022-07-08 Katrine Golubkov , Amy Novick-Cohen , Yotam Vaknin

Segment lengths along major strike-slip faults exhibit a size dependency related to the brittle crust thickness. These segments result in the formation of the localized 'P-shear' deformation crossing and connecting the initial Riedels…

By means of contact dynamics simulations, we analyze the stress state in a granular bed slowly tilted towards its angle of repose. An increasingly large number of grains are overloaded in the sense that they are found to carry a stress…

Soft Condensed Matter · Physics 2009-11-10 Lydie Staron , Jean-Pierre Vilotte , Farhang Radjai

Elevated pressures are encountered in many metal forming processes that can alter microstructural evolution rates. Here we measure rate changes with pressure in recrystallization and grain growth in Fe through adaptation of…

Materials Science · Physics 2023-11-14 Darren C. Pagan , Lukas A. Kissell , Matthew L. Whitaker

Deep-Earth volatile cycles couple the mantle with near-surface reservoirs. Volatiles are emitted by volcanism and, in particular, from mid-ocean ridges, which are the most prolific source of basaltic volcanism. Estimates of volatile…

Geophysics · Physics 2017-02-15 Tobias Keller , Richard F Katz , Marc M Hirschmann

The thermodynamic structure of protoplanetary discs is determined by dust opacities, which depend on the size of the dust grains and their chemical composition. In the inner regions, the grain sizes are regulated by the level of turbulence…

Earth and Planetary Astrophysics · Physics 2021-06-30 Jonas Müller , Sofia Savvidou , Bertram Bitsch

Evolution of grain mantles in various interstellar environment is studied. We concentrate mainly on water, methanol, carbon di-oxide, which constitute nearly 90% of the grain mantle. We investigate how the production rates of these…

Solar and Stellar Astrophysics · Physics 2010-11-11 Ankan Das , Kinsuk Acharyya , Sandip K. Chakrabarti