Discontinuities in granular materials: Particle-level mechanisms

2009 ◽  
pp. 223-237
Author(s):  
J. Carlos Santamarina ◽  
Hosung Shin
Keyword(s):  
Granular Materials ◽  
Particle Level

scholarly journals A constitutive model with microstructure evolution for flow of rate-independent granular materials

2011 ◽  
Vol 682 ◽  
pp. 590-616 ◽  
Author(s):  
JIN SUN ◽  
SANKARAN SUNDARESAN
Keyword(s):  
Friction Coefficient ◽  
Constitutive Model ◽  
Granular Materials ◽  
Simple Shear ◽  
Evolution Equations ◽  
Complex Loading ◽  
Dem Simulations ◽  
Particle Level ◽  
Complex Rheology ◽  
Using Data

A constitutive model is developed for the complex rheology of rate-independent granular materials. The closures for the pressure and the macroscopic friction coefficient are linked to microstructure through evolution equations for coordination number and fabric. The material constants in the model are functions of particle-level properties and are calibrated using data generated through simulations of steady and unsteady simple shear using the discrete element method (DEM). This model is verified against DEM simulations at complex loading conditions.

Neutron Diffraction Techniques in Granular Mechanics

2017 ◽  
Vol 905 ◽  
pp. 190-195
Author(s):  
Christopher M. Wensrich ◽  
Erich H. Kisi ◽  
Vladimir Luzin ◽  
Oliver Kirstein ◽  
Alexander L. Smith ◽  
...  
Keyword(s):  
Neutron Diffraction ◽  
Granular Materials ◽  
Plastic Anisotropy ◽  
Continuum Theory ◽  
Neutron Imaging ◽  
Three Dimensions ◽  
Force Transmission ◽  
Complex Behaviour ◽  
Granular Assemblies ◽  
Particle Level

Granular materials demonstrate unique mechanical properties stemming from their discrete nature. At large length scales granular assemblies are often viewed from the perspective of continuum theory where they show complex behaviour such as elastic and plastic anisotropy related to the load and deformation history. This complex behaviour is inextricably linked to the micromechanics of load sharing and force transmission at the particle level. At these scales, bulk stress is not shared homogeneously between particles, but rather by a network of `force chains' that form a skeleton supporting the vast majority of the applied load. The formation and failure of these structures govern much of the bulk behaviour of these materials. Neutron diffraction techniques are now providing a window into the mechanics of granular materials at both bulk and particle scales. Through a combination of tomographic neutron imaging and diffraction based strain measurement it is now possible to directly examine the stress within individual particles in granular assemblies. Results of these experiments in two and three dimensions are presented and the outlook for this approach to studying the mechanics of granular materials is discussed.

Dissipation in granular materials

1998 ◽  
Vol 77 (5) ◽  
pp. 1413-1425 ◽  
Author(s):  
Dietrich E.Wolf, Farhang Radjai, Sabine Dipp
Keyword(s):  
Granular Materials

Mechanisms and kinetics of gravity separation of granular materials

2020 ◽  
Vol 63 (6) ◽  
pp. 545-561
Author(s):  
V N Dolgunin ◽  
A N Kudi ◽  
M A Tuev
Keyword(s):  
Granular Materials ◽  
Gravity Separation ◽  
Kinetics Of

Toward the Analysis of the Structure of Granular Materials

2013 ◽  
Vol 58 (1) ◽  
pp. 32-39
Author(s):  
O.I. Gerasymov ◽  
◽  
A.G. Zagorodny ◽  
M.M. Somov ◽  
◽  
...  
Keyword(s):  
Granular Materials

A Prototype Homogenization Model for Acoustics of Granular Materials

2006 ◽  
Vol 4 (5-6) ◽  
pp. 585-600 ◽  
Author(s):  
Robert P. Gilbert ◽  
Alexander Panchenko ◽  
Xuming Xie
Keyword(s):  
Granular Materials ◽  
Homogenization Model

A Fused Thiophene-S,S-Dioxide-Based Super-Photostable Fluorescent Marker for Lipid Droplets

2020 ◽  
Author(s):  
Masayasu Taki ◽  
Keiji Kajiwara ◽  
Eriko Yamaguchi ◽  
Yoshikatsu Sato ◽  
Shigehiro Yamaguchi
Keyword(s):  
Small Molecules ◽  
Lipid Droplets ◽  
Trajectory Analysis ◽  
Super Resolution ◽  
Fluorescent Marker ◽  
Selective Staining ◽  
Fluorescent Markers ◽  
Biological Studies ◽  
Particle Level

Lipid droplets (LDs) are essential organelle in most eukaryotes, and tracking intracellular LDs dynamics using synthetic small molecules is crucial for biological studies. However, only a limited number of fluorescent markers that satisfy all requirements, such as the selective staining of LDs, high photostability, and sufficient biocompatibility, have been developed. Herein, we report a series of donor-p-acceptor dyes based on the thiophene-containing fused polycyclic scaffold [1]benzothieno[3,2-<i>b</i>][1]benzothiophene (BTBT), in which either or both thiophene rings are oxidized into thiophene-<i>S</i>,<i>S</i>-dioxide to form an electron-accepting building block. Among these dyes, LAQ1 satisfied all the aforementioned requirements, and allowed us capturing ultra-small LDs on the endoplasmic reticulum (ER) membrane by stimulation emission depletion (STED) microscopy with a super-resolution below the diffraction limit of light. Moreover, the extremely high photostability of LAQ1 enabled recording the lipolysis of LDs and the concomitant lipogenesis as well as long-term trajectory analysis of micro LDs at the single particle level in living cells.

Colloidal Plasmonic Nanostar Antennas with Wide Range Resonance Tunability

2019 ◽  
Author(s):  
Theodoros Tsoulos ◽  
Supriya Atta ◽  
Maureen Lagos ◽  
Michael Beetz ◽  
Philip Batson ◽  
...  
Keyword(s):  
Single Particle ◽  
Structural Complexity ◽  
Field Enhancement ◽  
Hot Electron ◽  
Structure Property ◽  
Plasmon Band ◽  
Gold Nanostars ◽  
Wide Range ◽  
Particle Level ◽  
Spectrally Resolved

<div>Gold nanostars display exceptional field enhancement properties and tunable resonant modes that can be leveraged to create effective imaging tags or phototherapeutic agents, or to design novel hot-electron based photocatalysts. From a fundamental standpoint, they represent important tunable platforms to study the dependence of hot carrier energy and dynamics on plasmon band intensity and position. Toward the realization of these platforms, holistic approaches taking into account both theory and experiments to study the fundamental behavior of these</div><div>particles are needed. Arguably, the intrinsic difficulties underlying this goal stem from the inability to rationally design and effectively synthesize nanoparticles that are sufficiently monodispersed to be employed for corroborations of the theoretical results without the need of single particle experiments. Herein, we report on our concerted computational and experimental effort to design, synthesize, and explain the origin and morphology-dependence of the plasmon modes of a novel gold nanostar system, with an approach that builds upon the well-known plasmon hybridization model. We have synthesized monodispersed samples of gold nanostars with finely tunable morphology employing seed-mediated colloidal protocols, and experimentally observed narrow and spectrally resolved harmonics of the primary surface plasmon resonance mode both at the single particle level (via electron energy loss spectroscopy) and in ensemble (by UV-Vis and ATR-FTIR spectroscopies). Computational results on complex anisotropic gold nanostructures are validated experimentally on samples prepared colloidally, underscoring their importance as ideal testbeds for the study of structure-property relationships in colloidal nanostructures of high structural complexity.</div>

EULER-LAGRANGE APPROACH OF DUST EMISSION AND DISPERSION FROM STOCKPILES OF GRANULAR MATERIALS

2016 ◽  
Author(s):  
Bruno Furieri ◽  
Edilson Luiz do Nascimento ◽  
Neyval Reis ◽  
jane meri Santos ◽  
Enilene Lovatte ◽  
...  
Keyword(s):  
Granular Materials ◽  
Dust Emission ◽  
Lagrange Approach
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