Prior studies indicated that mechanical loading influences cell turnover and matrix remodeling in tissues, suggesting that mechanical stimuli can play an active role in engineering artificial tissues. While most tissue culture studies focus on influence of uniaxial loading or constraints, effects of multi-axial loading or constraints on tissue development are far from clear. In this study, we e...

Uniaxial compression studies are performed on 50-mm-diameter bundles of nominally vertical, intertwined carbon nanotubes grown via chemical vapor deposition from a photolithographically defined catalyst. The inhomogeneous microstructure is examined, demonstrating density and tube orientation gradients, believed to play a role in the unique periodic buckling deformation mechanism. Through in sit...

We study the influence of a magnetic field on the biaxial nematic phase of board-like goethite colloids both experimentally and theoretically. Using synchrotron small angle X-ray scattering techniques we find that applying a magnetic field along the main director of the biaxial nematic phase leads to a clear decrease in biaxiality with increasing magnetic field strength. Above a certain magneti...

The phase behavior of amphiphilic anisometric particles is explored using Monte Carlo simulations. The particles are composed of two incompatible laterally attached units: a spherocylinder and a spheroplatelet. A liquid crystalline phase polymorphism is obtained including biaxial nematic, (quasi long range biaxial) calamitic smectic-A, biaxial lamellar and columnar phases. The simulation result...

We study the nonlinear deformations of a long rectangular elastic plate clamped along its edges and submitted to in-plane biaxial compression. Using the Föppl–von Kármán equations, we predict various secondary buckling modes according to the applied longitudinal and transverse compressions. A model experiment is carried out in a thin polycarbonate film, and the observed buckling patterns are fo...

We have determined the phase diagram for a lattice system of biaxial particles interacting with a second rank anisotropic potential using Monte Carlo simulations for a number of values of the molecular biaxiality. We find increasing differences from mean field theory as the biaxiality increases. We have also calculated for the first time the full set of second rank biaxial and uniaxial order pa...

Infrared absorbance measurements have been carried out on two liquid crystalline organo-siloxane tetrapodes. Results unambiguously show the existence of a biaxial nematic phase below a uniaxial nematic phase. The three components of IR absorbance are used to calculate the various order parameters. On cooling, a weak first-order transition from isotropic to nematic is observed, followed by a sec...

A method of measuring biaxial stress-strain curves for sheet metal samples subjected to large plastic strains is described for one example aluminum alloy (AA 5754-O). The method uses a portable X-ray diffraction (XRD) system to measure in situ stresses during tensile deformations. Calibration of X-ray elastic constants and the effects of texture and intergranular stresses are discussed. Uniaxia...

The defect structures of s = ±1/2 twist disclinations in twisted nematic and twisted chiral liquid crystals have been investigated within the Landau-de Gennes theory numerically. Our results show that there exists eigenvalue exchange across the defect core of both the two models. The defect core is essentially biaxial and never isotropic. The defect centre is uniaxial and is surrounded by a str...

We have studied a system of discotic particles with a central transverse dipole using Monte Carlo (MC) computer simulations at constant pressure. We have investigated several temperatures corresponding to nematic and columnar liquid crystal phases and determined the molecular and dipolar organizations. Low temperature columnar phases are characterized by local biaxial ordering of dipoles, even ...