Elementary Hydrostatics

Close - packed granular clusters : hydrostatics and persistent Gaussian fluctuations

Dense granular clusters often behave like macroparticles. We address this interesting phenomenon in a model system of inelastically colliding hard disks inside a circular box, driven by a thermal wall at zero gravity. Molecular dynamics simulations show a close-packed cluster of an almost circular shape, weakly fluctuating in space and isolated from the driving wall by a low-density gas. The de...

Elementary categories, elementary toposes

Function and hydrostatics in the telson of the Burgess Shale arthropod Burgessia.

Burgessia bella is a characteristic Burgess Shale arthropod (508 Ma), but the unusual preservation of its telson in both straight and bent modes leads to contradictory interpretations of its function. A reinvestigation of the fossil material, including burial attitudes, combined with a comparison with the decay sequence and mechanics of the telson in living Limulus, demonstrates that the telson...

Ecological nuances in functional magnetic resonance imaging (fMRI): psychological stressors, posture, and hydrostatics.

Brain imaging techniques such as functional magnetic resonance imaging (fMRI) have forged an impressive link between psychology and neuroscience. Whereas most experiments in cognitive psychology require participants to perform while sitting upright in front of display devices, fMRI obliges participants to perform cognitive tasks while lying supine and motionless inside a narrow bore. In additio...

Hydrostatics and Dynamical Large Deviations of Boundary Driven Gradient Symmetric Exclusion Processes

We prove hydrostatics of boundary driven gradient exclusion processes, Fick’s law and we present a simple proof of the dynamical large deviations principle which holds in any dimension.