statistical mechanics

We investigate the mechanics and stability of a nanoscale origami crease via a combination of equilibrium and nonequilibrium statistical mechanics. We identify an entropic torque on nanoscale origami creases, and find stability properties have a nontrivial dependence on bending stiffness, radii of curvature of its creases, ambient temperature, its thickness, and its interfacial energy.

Fatemeh Ahmadpoor

New Jersey Institute of Technology

Dear colleagues,

We invite you to see the preprint of our new paper "Statistical mechanics of a dielectric polymer chain in the force ensemble" that will appear in Journal of the Mechanics and Physics of Solids. Here we compute the electroelasticity of single polymer chains using both analytical approximations and novel MCMC techniques. Working in the fixed force ensemble facilitates the derivation of the analytical approximations, which are shown to agree well with the MCMC results. This work complements prior work on the statistical mechanics of dielectric polymers chains obtained in a different ensemble. (https://doi.org/10.1016/j.jmps.2021.104658).

I highly recommend this paper to any mechanician who is familiar with the scientific efforst in the last 150 years to unify mechanics and thermodynamics. Sosnoskiy and Sherbakov and several others from the Russian Academy of Sciences listed in the Acknowledgemnsts have achieved it. Congratulations.

Sosnovskiy, L. Sherbakov, S.,”Mechanothermodynamic Entropy and Analysis of Damage State of Complex Systems”, Entropy, 2016, 18, 268.

Peridynamic theory of solids from the perspective of classical statistical mechanics

R. Rahman, J.T. Foster

Highlights

For centuries, great minds like Kepler, Maxwell and Einstein have investigated the statistical characterization of many-body systems, and implications of small-scale structures on the macroscopic transport and mechanical properties. In this work, an accurate statistical description of heterogeneous particulate materials is computed using novel adaptive interpolation/integration scheme. This statistical information is then utilized within mathematical theories for predicting the overall thermo-mechanical behavior.

Contact: Dr. Siddiq Qidwai, siddiq.qidwai@nrl.navy.mil

Postdoc Information: http://hroffice.nrl.navy.mil/jobs/postdoc.htm. Note the substantial stipend and benefits.

A single strand of polymer is a chain of a large number of monomers.  The monomers are joined by covalent bonds, and two bonded monomers may rotate relative to each other.  At a finite temperature, the polymer rapidly changes from one configuration to another.  When the two ends of the polymer are pulled by a force, the distance between the two ends changes.  The polymer is known as an entropic spring.

We are currently looking for a top candidate to join the System Level Design group at CMU (www.ece.cmu.edu/~sld/), as a Postdoctoral Associate, starting Spring 2013. Main responsibilities involve work on modeling and control of stochastic micro-robotic swarms targeting biological applications.

Notes and slides for a course on engineering thermodynamics.  I used the Dover edition of Carnot's book.

(Journal of Elasticity, Carlson memorial Volume)

A methodology is devised to utilize the statistical mechanical entropy of an isolated, constrained atomistic system to define the dissipative driving-force and energetic fields in continuum thermomechanics. A thermodynamic model of dislocation mechanics is discussed. One outcome is a definition for the mesoscale back-stress tensor and the symmetric, polar dislocation density-dependent, Cauchy stress tensor from atomistic ingredients.

For a system in thermal contact with the rest of the world, we have described three quantities: entropy, energy, and temperature. We have also described the idea of a constraint internal to the system, and associated this constraint to an internal variable.

The lecture notes of the two courses I taught at Stanford University during the last two quarters, "ME 340 Elasticity" and "ME 334 Introduction to Statistical Mechanics", are available in PDF format online at:

  http://micro.stanford.edu/~caiwei/me340/

  http://micro.stanford.edu/~caiwei/me334/

Perhaps it could be useful to you.

5 Lectureships and 5 Post-Doctoral Research Fellowships in the EPSRC funded national Centre for Advanced Tribology at Southampton (nCATS) 

Lectureships: £32,795 to £41,545

How to measure the temperature of a nanotube?