19 research outputs found
Dynamics of axial separation in long rotating drums
We propose a continuum description for the axial separation of granular
materials in a long rotating drum. The model, operating with two local
variables, concentration difference and the dynamic angle of repose, describes
both initial transient traveling wave dynamics and long-term segregation of the
binary mixture. Segregation proceeds through ultra-slow logarithmic coarsening.Comment: 4 pages, 3 Postscript figures; submitted to PR
Skin Bioimpedance Analysis to Determine Cellular Integrity by Phase Angle in Women with Fibromyalgia: A Cross-Sectional Study.
Oxidative stress has been proposed as a significant part of the pathogenesis of fibromyalgia,
and the phase angle in bioelectrical impedance analysis has been explored as a potential technique to
screen oxidative abnormalities. This study recruited 35 women with fibromyalgia and 35 healthy
women, who underwent bioelectrical impedance analysis and maximum isometric handgrip strength
tests. Women with fibromyalgia showed lower bilateral handgrip strength (right hand: 16.39 ± 5.87
vs. 27.53 ± 4.09, p < 0.001; left hand: 16.31 ± 5.51 vs. 27.61 ± 4.14, p < 0.001), as well as higher body
fat mass (27.14 ± 10.21 vs. 19.94 ± 7.25, p = 0.002), body fat percentage (37.80 ± 8.32 vs. 30.63 ± 7.77,
p < 0.001), and visceral fat area (136.76 ± 55.31 vs. 91.65 ± 42.04, p < 0.01) compared with healthy
women. There was no statistically significant difference in muscle mass between groups, but women
with fibromyalgia showed lower phase angles in all body regions when compared with healthy
control women (right arm: 4.42 ± 0.51 vs. 4.97 ± 0.48, p < 0.01; left arm: 4.23 ± 0.48 vs. 4.78 ± 0.50,
p < 0.001; trunk: 5.62 ± 0.77 vs. 6.78 ± 0.84, p < 0.001; right leg: 5.28 ± 0.56 vs. 5.81 ± 0.60, p < 0.001;
left leg: 5.07 ± 0.51 vs. 5.69 ± 0.58, p < 0.001; whole body: 4.81 ± 0.47 vs. 5.39 ± 0.49, p < 0.001).
Moreover, whole-body phase-angle reduction was only predicted by the presence of fibromyalgia
(R 2 = 0.264; β = 0.639; F(1,68) = 24.411; p < 0.001). Our study revealed significantly lower phase angle
values, lower handgrip strength, and higher fat levels in women with fibromyalgia compared to
healthy controls, which are data of clinical relevance when dealing with such patients.post-print1,25 M
Patterns and Collective Behavior in Granular Media: Theoretical Concepts
Granular materials are ubiquitous in our daily lives. While they have been a
subject of intensive engineering research for centuries, in the last decade
granular matter attracted significant attention of physicists. Yet despite a
major efforts by many groups, the theoretical description of granular systems
remains largely a plethora of different, often contradicting concepts and
approaches. Authors give an overview of various theoretical models emerged in
the physics of granular matter, with the focus on the onset of collective
behavior and pattern formation. Their aim is two-fold: to identify general
principles common for granular systems and other complex non-equilibrium
systems, and to elucidate important distinctions between collective behavior in
granular and continuum pattern-forming systems.Comment: Submitted to Reviews of Modern Physics. Full text with figures (2Mb
pdf) avaliable at
http://mti.msd.anl.gov/AransonTsimringReview/aranson_tsimring.pdf Community
responce is appreciated. Comments/suggestions send to [email protected]
Mars Express: The Exploration of Phobos
The origin, structure and composition of Phobos are essentially still unresolved issue, with major outcomes for understanding the origin and evolution of the Solar system, and of the Mars system. Several missions have been designed with this unique body the only target. Is Phobos a captured small body (and in this case, can we identify the degree of differentiation such a small object has undergone ?), or is there any co-generic process with Mars involved ? Are there still volatile species trapped, and if so where, and in what form ? What are the reciprocal contributions of Mars and Phobos material accreted in the other body? The number of key clues for deciphering the early solar system processes, the Mars-Phobos binary evolution, and the role Phobos could play in the future of Mars exploration (including human expeditions), are numerous, and exciting for a large community. Part of the answers are in the high resolution coverage of this object (optical and IR, for composition variation), and in its full spectral analysis, from UV to thermal IR : Mars Express is the unique mission to provide this opportunity, and orbit 756, August 22, a totally unique opportunity to approach Phobos so closely. OMEGA should provide all across Stickney, the deepest accessible material, and over more than 20 km along, a spatial resolution less than 200 m, and assess the composition (and possibly their variations) wrt silicates (mafic materials), oxides, and eventually hydrated minerals and organics. By no means we should miss this opportunity: no one would understand the rationale not to turn the instruments ON while so close, and pointing them towards the Phobos surface
Proposal For a European Lander Mission Roadmap To Explore Mars.
Proposition soumise à l'ES