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2019

Physics and Astronomy Publications

Articles 1 - 3 of 3

Full-Text Articles in Physics

Stability Of Binary Colloidal Crystals Immersed In A Cholesteric Liquid Crystal, Setarehalsadat Changizrezaei, Colin Denniston May 2019

Stability Of Binary Colloidal Crystals Immersed In A Cholesteric Liquid Crystal, Setarehalsadat Changizrezaei, Colin Denniston

Physics and Astronomy Publications

In this paper, we model a number of both closed-packed and non-closed-packed crystals inside a cholesteric liquid crystal (LC) with different pitch values and nematic LC through the Landau–de Gennes free-energy method. We used binary boundary conditions (normal and planar anchoring) applied on the surface of colloids as we are interested in investigating the stability of binary crystals. The results indicate that body-centered-cubic (BCC) crystals have a lower-energy lattice defect structure than the diamond crystal, and the most energetically favorable BCC lattice can be formed in a cholesteric liquid crystal with a pitch value commensurate with the lattice spacing. Furthermore, …


An Analytic Study Of The Wiedemann-Franz Law And The Thermoelectric Figure Of Merit, Aakash Yadav, Pc Deshmukh, Ken Roberts, Nm Jisrawi, Sree Ram Valluri Apr 2019

An Analytic Study Of The Wiedemann-Franz Law And The Thermoelectric Figure Of Merit, Aakash Yadav, Pc Deshmukh, Ken Roberts, Nm Jisrawi, Sree Ram Valluri

Physics and Astronomy Publications

Advances in optimizing thermoelectric material efficiency have seen a parallel activity in theoretical and computational advances. In the current work, it is shown that the calculation of exact Fermi-Dirac integrals enables the generalization of the Wiedemann-Franz law (WF) to optimize the dimensionless thermoelectric figure of merit ZT. This is done by optimizing the Seebeck coefficient, the electrical conductivity and the thermal conductivity. In the calculation of the thermal conductivity, both electronic and phononic contributions are included. The solutions provide insight into the relevant parameter space including the physical significance of complex solutions and their dependence on the scattering parameter r …


Simulations Of Microscopic Propulsion Of Soft Elastic Bodies, David Urbanik, Shikhar Man Dwivedi, Colin Denniston Feb 2019

Simulations Of Microscopic Propulsion Of Soft Elastic Bodies, David Urbanik, Shikhar Man Dwivedi, Colin Denniston

Physics and Astronomy Publications

Using simulations that realistically model both hydrodynamic and elastic behavior, we study the motion of a microscopic, driven elastic sphere immersed in water. We first confirm the “jittery” relaxation recently predicted theoretically for an externally driven elastic sphere. The sphere is then divided in two and each section is driven internally with the two sections 180° out of phase. With periodic and perfectly symmetric driving, the elastic sphere spontaneously breaks symmetry and can attain macroscopic average swimming velocities to the right or left, the direction depending only on the initial state. With asymmetric driving the elastic sphere swims in one …