This paper reports an investigation of dynamical behaviors of motile rod-shaped bacteria within anisotropic viscoelastic environments defined by lyotropic liquid crystals (LCs). In contrast to passive microparticles (including non-motile bacteria) that associate irreversibly in LCs via elasticity-mediated forces, we report that motile Proteus mirabilis bacteria form dynamic and reversible multi...

Magnetic resonance elastography (MRE) is a noninvasive method that allows the determination of in vivo shear elasticity of soft tissues. In this thesis methods for the determination of isotropic and anisotropic shear elasticities from MRE wave data were developed and evaluated. All methods presented in this work are based on planar MRE, i.e. they are based on the measurement of a single displac...

We consider the Cahn–Hilliard equation — a fourth–order, nonlinear parabolic diffusion equation describing phase separation of a binary alloy which is quenched below a critical temperature. The occurrence of two phases is due to a nonconvex double well free energy. The evolution initially leads to a very fine microstructure of regions with different phases which tend to become coarser at later ...

We present a model to investigate the formation of surface patterns in biological materials through the interaction of anisotropic interfacial tension, bending elasticity, and capillarity at their free surfaces. Focusing on the cholesteric liquid crystal (CLC) material model, the generalized shape equation for anisotropic interfaces using the Rapini-Papoular anchoring and Helfrich free energies...

Colloidal hybrids comprise organic and inorganic components and are attracting considerable attention in the literature. Recently, we reported hybrid anisotropic microsheets that formed thermoresponsive gels in polymer solutions [Liu et al., Langmuir, 25, 490, 2009]. Here, we investigate the composition and properties of these hybrid colloids themselves in detail for the first time. Three diffe...

Bacteria often inhabit and exhibit distinct dynamical behaviors at interfaces, but the physical mechanisms by which interfaces cue bacteria are still poorly understood. In this work, we use interfaces formed between coexisting isotropic and liquid crystal (LC) phases to provide insight into how mechanical anisotropy and defects in LC ordering influence fundamental bacterial behaviors. Specifica...

Recent Particle System models have evolved toward accurate representation of elastic stiffness based on continuum mechanics, converging to formulations that make them quite analogous to fast Finite Element methods. These formulations usually involve the linearization of tensors that help their formulation in the context of linear elasticity. Toward our objective of simulating the nonlinear prop...

In this article we describe the latest developments of the minimally invasive hepatic surgery simulator pro totype developed at INRIA A key problem with such a simulator is the physical modeling of soft tissues We propose a new deformable model based on non linear elasticity and the nite element method This model is valid for large displacements which means in particu lar that it is invariant w...

2014 Paratellurite TeO2 is a crystal with exceptional anisotropic elasticity. This is the origin of interesting acousto-optical applications; as they depend on crystalline perfection, dislocations are of particular importance and their properties are also directly linked to elasticity. We have calculated the energy of dislocations with [100], [110] and [001] Burgers vectors : in some cases, it ...

Recent studies show that the D'' layer, just above the Earth's core-mantle boundary, is composed of MgSiO3 post-perovskite and has significant lateral inhomogeneity. Here we consider the D'' diversity as related to the single-crystal elasticity of the post-perovskite phase. We measure the single-crystal elasticity of the perovskite Pbnm-CaIrO3 and post-perovskite Cmcm-CaIrO3 using inelastic X-r...