Continuum modelling of shock waves through granular gases and the role of statistical fluctuations

2016 ◽  
Author(s):  
Nick Sirmas ◽  
Matei I. Radulescu
Keyword(s):  
Shock Waves ◽  
Granular Gases ◽  
Statistical Fluctuations ◽  
Continuum Modelling

scholarly journals The Role of Mesh Generation, Adaptation, and Refinement on the Computation of Flows Featuring Strong Shocks

2012 ◽  
Vol 2012 ◽  
pp. 1-15 ◽  
Author(s):  
Aldo Bonfiglioli ◽  
Renato Paciorri ◽  
Andrea Di Mascio
Keyword(s):  
Shock Waves ◽  
Mesh Generation ◽  
The Other ◽  
Shock Capturing ◽  
Structured Grids ◽  
Computational Mesh ◽  
Versatile Technique ◽  
Coarse Meshes ◽  
Shock Fitting

Within a continuum framework, flows featuring shock waves can be modelled by means of either shock capturing or shock fitting. Shock-capturing codes are algorithmically simple, but are plagued by a number of numerical troubles, particularly evident when shocks are strong and the grids unstructured. On the other hand, shock-fitting algorithms on structured grids allow to accurately compute solutions on coarse meshes, but tend to be algorithmically complex. We show how recent advances in computational mesh generation allow to relieve some of the difficulties encountered by shock capturing and contribute towards making shock fitting on unstructured meshes a versatile technique.

Role of laser-induced stress and shock waves in modification of the photoconductivity of films

1998 ◽  
Vol 13 (11) ◽  
pp. 1298-1303 ◽  
Author(s):  
V A Gnatyuk ◽  
A I Vlasenko ◽  
P O Mozol' ◽  
O S Gorodnychenko
Keyword(s):  
Shock Waves ◽  
Induced Stress ◽  
And Shock Waves

The Materialism Controversy

After Hegel ◽  
2014 ◽  
Author(s):  
Frederick C. Beiser
Keyword(s):  
Nineteenth Century ◽  
Shock Waves ◽  
Free Will ◽  
Natural Science ◽  
Main Question ◽  
Modern Natural ◽  
Modern Natural Science ◽  
Scientific Materialism ◽  
Reason And Faith

This chapter examines the so-called “materialism controversy,” one of the most important intellectual disputes of the second half of the nineteenth century. The dispute began in the 1850s, and its shock waves reverberated until the end of the century. The main question posed by the materialism controversy was whether modern natural science, whose authority and prestige were now beyond question, necessarily leads to materialism. Materialism was generally understood to be the doctrine that only matter exists and that everything in nature obeys only mechanical laws. If such a doctrine were true, it seemed there could be no God, no free will, no soul, and hence no immortality. These beliefs, however, seemed vital to morality and religion. So the controversy posed a drastic dilemma: either a scientific materialism or a moral and religious “leap of faith.” It was the latest version of the old conflict between reason and faith, where now the role of reason was played by natural science.

Key role of the expression of bone morphogenetic proteins in increasing the osteogenic activity of osteoblast-like cells exposed to shock waves and seeded on bioactive glass-ceramic scaffolds for bone tissue engineering

2014 ◽  
Vol 29 (5) ◽  
pp. 728-736 ◽  
Author(s):  
Giuliana Muzio ◽  
Germana Martinasso ◽  
Francesco Baino ◽  
Roberto Frairia ◽  
Chiara Vitale-Brovarone ◽  
...  
Keyword(s):  
Shock Wave ◽  
Alkaline Phosphatase ◽  
Shock Waves ◽  
Bioactive Glass ◽  
Bone Morphogenetic Protein ◽  
Bone Morphogenetic Proteins ◽  
Glass Ceramic ◽  
Osteogenic Activity ◽  
Morphogenetic Protein

In this work, the role of shock wave-induced increase of bone morphogenetic proteins in modulating the osteogenic properties of osteoblast-like cells seeded on a bioactive scaffold was investigated using gremlin as a bone morphogenetic protein antagonist. Bone-like glass-ceramic scaffolds, based on a silicate experimental bioactive glass developed at the Politecnico di Torino, were produced by the sponge replication method and used as porous substrates for cell culture. Human MG-63 cells, exposed to shock waves and seeded on the scaffolds, were treated with gremlin every two days and analysed after 20 days for the expression of osteoblast differentiation markers. Shock waves have been shown to induce osteogenic activity mediated by increased expression of alkaline phosphatase, osteocalcin, type I collagen, BMP-4 and BMP-7. Cells exposed to shock waves plus gremlin showed increased growth in comparison with cells treated with shock waves alone and, conversely, mRNA contents of alkaline phosphatase and osteocalcin were significantly lower. Therefore, the shock wave-mediated increased expression of bone morphogenetic protein in MG-63 cells seeded on the scaffolds is essential in improving osteogenic activity; blocking bone morphogenetic protein via gremlin completely prevents the increase of alkaline phosphatase and osteocalcin. The results confirmed that the combination of glass-ceramic scaffolds and shock waves exposure could be used to significantly improve osteogenesis opening new perspectives for bone regenerative medicine.

Role of statistical fluctuations for the interpretation of Arrhenius-type plots in nuclear multifragmentation

1997 ◽  
Vol 56 (4) ◽  
pp. R1683-R1686 ◽  
Author(s):  
J. Tõke ◽  
D. K. Agnihotri ◽  
B. Djerroud ◽  
W. Skulski ◽  
W. U. Schröder
Keyword(s):  
Statistical Fluctuations ◽  
Nuclear Multifragmentation

MODELS OF FREE COOLING GRANULAR GASES

2001 ◽  
Vol 04 (04) ◽  
pp. 321-331 ◽  
Author(s):  
UMBERTO MARINI BETTOLO MARCONI ◽  
ANDREA BALDASSARRI ◽  
ANDREA PUGLISI
Keyword(s):  
Kinetic Energy ◽  
Lattice Model ◽  
Topological Defects ◽  
Total Momentum ◽  
Granular Gases ◽  
Two Dimensional ◽  
Spatial Structures ◽  
Free Evolution ◽  
Free Cooling

We consider the free evolution of systems of granular particles whose dynamics is characterized by a collision rule which preserves the total momentum, but dissipates the kinetic energy. Starting from an inelastic version of a minimal model proposed by Ulam for a gas of Maxwell molecules, we introduce a new lattice model aimed at investigating the role of dynamical correlations and the onset of spatial order induced by the inelasticity of the interactions. We study, in one- and two-dimensional cases, the velocity distribution, the decay of the energy, the formation of spatial structures and topological defects. Finally, we relate our findings to other models known in other fields.

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