Granular behavior in polycrystallineSm2−xCexCuO4−ycompounds

1994 ◽  
Vol 50 (14) ◽  
pp. 10080-10087 ◽  
Author(s):  
R. F. Jardim ◽  
L. Ben-Dor ◽  
D. Stroud ◽  
M. B. Maple
Keyword(s):  
Granular Behavior

scholarly journals La Palma landslide tsunami: computation of the tsunami source with a calibrated multi-fluid Navier–Stokes model and wave impact assessment with propagation models of different types

2019 ◽  
Author(s):  
Stéphane Abadie ◽  
Alexandre Paris ◽  
Riadh Ata ◽  
Sylvestre Le Roy ◽  
Gael Arnaud ◽  
...  
Keyword(s):  
Water Waves ◽  
Model Simulation ◽  
Tsunami Source ◽  
Navier Stokes ◽  
Time Of Arrival ◽  
Wave Impact ◽  
Boussinesq Model ◽  
Wave Source ◽  
La Palma ◽  
Granular Behavior

Abstract. In this paper, we present a new source assessment of the La Palma collapse scenario previously described and studied in Abadie et al. (2012). Three scenarios (i.e., slide volumes of 20, 40 and 80 km3) are considered, from the initiation of the slide to the water waves generation, using THETIS, a 3D Navier–Stokes model. The slide is considered as a Newtonian fluid whose viscosity is adjusted to approximate a granular behavior. After 5 minutes of propagation with THETIS, the generated water wave is transferred into FUNWAVE-TVD for 15 minutes of Boussinesq model simulation. Then, four different depth-averaged codes are used to propagate the wave to the Guadeloupe area, Europe and French coasts. Finally, the wave impact in terms of run-up is evaluated through direct computations in specific areas or using theoretical formulas. Although the wave source appears reduced due to the rheology used compared to former works, the wave impact is still significant for the maximum slide volume considered on surrounding islands and coasts, as well as on remote most exposed coasts such as Guadeloupe. In Europe and in France, the wave impact is moderate (for specific areas in Spain and Portugal) to weak (Atlantic French coast). The comparison between the different wave models in overlapping computational regions shows an overall agreement in terms of first wave amplitude and time of arrival, but differences appear in the trailing waves.

scholarly journals Geometry-dependent constitutive law for granular slow frictional drag

2017 ◽  
Vol 31 (10) ◽  
pp. 1742006 ◽  
Author(s):  
T. Furuta ◽  
K. Katou ◽  
S. Itoh ◽  
K. Tachibana ◽  
S. Ishikawa ◽  
...  
Keyword(s):  
Confining Pressure ◽  
Constitutive Law ◽  
Dimensionless Number ◽  
Shear Strain Rate ◽  
Granular Bed ◽  
Frictional Drag ◽  
Essential Parameter ◽  
Number Formula ◽  
Dense Flow ◽  
Granular Behavior

Frictional constitutive law for very slow vertical withdrawing of a thin rod from a granular bed is experimentally studied. Using a very precise creep meter, geometry-dependent granular frictional constitutive law is particularly examined. In some previous works, a dimensionless number [Formula: see text] has been used to characterize granular frictional constitutive laws, where [Formula: see text], [Formula: see text], [Formula: see text], and [Formula: see text] are the shear strain rate, grain diameter, confining pressure, and bulk density of granular bed, respectively. It has been considered that granular frictional constitutive law expressed by [Formula: see text] is universal (almost geometry-independent) in dense flow regime. In this study, however, we find that the geometry of the system is much more crucial to characterize granular friction in a very slow withdrawing regime. Specifically, the ratio between rod and grain diameters must be an essential parameter to describe the granular frictional constitutive law. Physical meaning of the geometry-dependent constitutive law is discussed on the basis of grains-contact-number dependence of granular behavior.

Viscoplastic and Granular Behavior in Films of Colloidal Nanocrystals

2007 ◽  
Vol 98 (2) ◽  
Author(s):  
Dongyun Lee ◽  
Shengguo Jia ◽  
Sarbajit Banerjee ◽  
Joze Bevk ◽  
Irving P. Herman ◽  
...  
Keyword(s):  
Colloidal Nanocrystals ◽  
Granular Behavior

scholarly journals Merging fluid and solid granular behavior

Soft Matter ◽  
2016 ◽  
Vol 12 (41) ◽  
pp. 8616-8628 ◽  
Author(s):  
Dalila Vescovi ◽  
Stefan Luding
Keyword(s):  
Granular Behavior

Granular behavior observed in the polycrystalline superconducting LiFeAs

2015 ◽  
Vol 28 (2) ◽  
pp. 025006 ◽  
Author(s):  
Shiv Jee Singh ◽  
Robert Beck ◽  
Sabine Wurmehl ◽  
Christian Hess ◽  
Bernd Büchner
Keyword(s):  
Granular Behavior

scholarly journals La Palma landslide tsunami: calibrated wave source and assessment of impact on French territories

2020 ◽  
Vol 20 (11) ◽  
pp. 3019-3038
Author(s):  
Stéphane Abadie ◽  
Alexandre Paris ◽  
Riadh Ata ◽  
Sylvestre Le Roy ◽  
Gael Arnaud ◽  
...  
Keyword(s):  
Model Simulation ◽  
Water Model ◽  
Navier Stokes ◽  
Wave Impact ◽  
Boussinesq Model ◽  
Propagation Models ◽  
Wave Source ◽  
La Palma ◽  
Granular Behavior ◽  
Landslide Tsunami

Abstract. In this paper, we present new results on the potential La Palma collapse event, previously described and studied in Abadie et al. (2012). Three scenarios (i.e., slide volumes of 20, 40 and 80 km3) are considered, modeling the initiation of the slide to the water generation using THETIS, a 3D Navier–Stokes model. The slide is a Newtonian fluid whose viscosity is adjusted to approximate a granular behavior. After 5 min of propagation with THETIS, the generated water wave is transferred into FUNWAVE-TVD (Total Variation Diminishing version of FUNWAVE) to build a wave source suitable for propagation models. The results obtained for all the volumes after 15 min of Boussinesq model simulation are made available through a public repository. The signal is then propagated with two different Boussinesq models: FUNWAVE-TVD and Calypso. An overall good agreement is found between the two models, which secures the validity of the results. Finally, a detailed impact study is carried out on La Guadeloupe using a refined shallow water model, SCHISM, initiated with the FUNWAVE-TVD solution in the nearshore area. Although the slide modeling approach applied in this study seemingly leads to smaller waves compared to former works, the wave impact is still very significant for the maximum slide volume considered on surrounding islands and coasts, as well as on the most exposed remote coasts such as Guadeloupe. In Europe, the wave impact is significant (for specific areas in Spain and Portugal) to moderate (Atlantic French coast).

Evolution from multilayer to granular behavior via Cobalt layers fragmentation in Co/Cu multilayers

2003 ◽  
Vol 262 (1) ◽  
pp. 120-123 ◽  
Author(s):  
P Vavassori ◽  
F Spizzo ◽  
E Angeli ◽  
D Bisero ◽  
F Ronconi
Keyword(s):  
Granular Behavior

Using a Lattice-Based Cellular Automata Approach to Model the Load Carrying Capacity of Granular Flows

2007 ◽  
Author(s):  
Venkata K. Jasti ◽  
C. Fred Higgs
Keyword(s):  
Cellular Automata ◽  
Carrying Capacity ◽  
Extreme Temperature ◽  
Granular Flows ◽  
Load Carrying Capacity ◽  
Local Flow ◽  
The Past ◽  
Load Carrying ◽  
Ca Model ◽  
Granular Behavior

Flows of solid granular particles are proposed as an alternate lubrication mechanism to conventional liquid lubrication in sliding contacts, because of their ability to carry loads and to accommodate surface velocities. Alternate lubrication is becoming necessary in extreme temperature environments where liquid lubricants fail and in micro/nanoscale environments were they promote stiction. However understanding granular behavior has been a challenge because of their ability to behave as solids, liquids and gases with varying circumstances. Cellular automata (CA), a deterministic rule based mathematics approach, has been successful in modeling some complex aspects of granular behavior. Our previous work successfully modeled granular shear with CA model. This work introduces a more versatile and novel cellular automata framework which combines the computational efficiency of CA with the power of particle dynamics to capture collision events. In the past, the load carrying capacity of granular flows was demonstrated in the experiments conducted by Yu and Tichy [2] and later, local flow properties were modeled using the granular kinetic lubrication continuum modeling approach. These results were used as a benchmark for determining the effectiveness of the current CA model.

The Granular Behavior of LaSrCuO: Oxygen Concentration Effects on the Electrical Resistivity

1987 ◽  
Vol 99 ◽  
Author(s):  
E. Osquiguil ◽  
L. Civale ◽  
R. Decca ◽  
H. Safar ◽  
E. Martinez ◽  
...  
Keyword(s):  
Electrical Resistivity ◽  
Oxygen Content ◽  
Oxygen Concentration ◽  
Superconducting Properties ◽  
Concentration Effects ◽  
Resistivity Measurements ◽  
Clean Limit ◽  
Ceramic Superconductors ◽  
Wide Range ◽  
Granular Behavior

ABSTRACTElectrical resistivity measurements of the superconductor La1.80sr0.20CuO4-δ over a Wide range of temperatures and oxygen concentration, together with the analysis of superconducting properties of the material, indicate that the ceramic superconductors are high < materials in the clean limit. The granular superconducting behavior is determined by the oxygen content.

Including Friction and Spin Rules in the Lattice-Based Cellular Automata Approach to Model Granular Flows

2009 ◽  
Author(s):  
Martin C. Marinack ◽  
Venkata K. Jasti ◽  
C. Fred Higgs
Keyword(s):  
Cellular Automata ◽  
Computational Efficiency ◽  
Granular Flow ◽  
Extreme Temperature ◽  
Granular Flows ◽  
Friction Modeling ◽  
Model Collision ◽  
Ca Model ◽  
Granular Behavior ◽  
Multiphase Behavior

Granular flows have been proposed as an alternative lubrication mechanism to conventional liquid lubricants in sliding contacts due to their ability to carry loads and accommodate surface velocities. Their load carrying capacity has been demonstrated in the experiments of Yu and Tichy [1]. Alternate lubrication techniques are becoming necessary due to the failure of conventional liquid lubricants in extreme temperature environments, and their promotion of stiction in micro-/nanoscale environments. Yet, understanding granular behavior has been difficult due to its non-linear and multiphase behavior. Cellular Automata (CA) has been shown to be a viable first order approach to modeling some complex aspects of granular flow. Previous work by the authors successfully modeled granular shear with a CA model [2]. Additional work combined CA computational efficiency with particle dynamics to effectively model collision events. This work builds upon and modifies the prior CA modeling approaches by adding friction modeling and spin of particles. This modification maintains the computational efficiency of CA, while increasing accuracy of the predicted granular flow properties, such as speed, solid fraction, and granular temperature. The current work compares the CA model with friction and spin physics relations to the authors’ prior CA model which neglected friction. Both CA models are also evaluated against experimental data to quantify the benefits of including friction and spin in the CA modeling approach for granular flows.

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