Even though isolated defect-free single-wall carbon nanotubes are straight, bundles of chiral single-wall carbon nanotubes are often helical according to our observations using high-resolution electron microscopy. The driving force for the formation of such helices is the energy gain associated with the optimum orientational alignment of neighboring nanotubes. Our total energy calculations allo...

Stronger constraints on the pseudoscalar coupling constants of an axion to a proton and a neutron are obtained from an indirect measurement of the effective Casimir pressure between two Au-coated plates by means of micromechanical torsional oscillator. For this purpose, the additional effective pressure due to two-axion exchange is calculated. The role of boundary effects and the validity regio...

This paper describes the Lyapunov-based force control suppressing the coupled bending and torsional vibrations of a one-link flexible arm with a rigid tip body. On the basis of the distributed parameter model, the output feedback control law is constructed using Lyapunov method, and the asymptotic stability of the closedloop system is proved. The proposed controller consists of the PD feedback ...

Abstract: The flow generated by a circular cylinder, performing longitudinal and torsional oscillations, in an infinite expanse of a micropolar fluid is studied under the influence of uniform transverse magnetic field. Analytical expressions for the velocity components and micro rotation components are obtained by using no slip and hyper stick conditions on the boundary of the cylinder. The eff...

Atomic force microscopes have become indispensable tools for mechanical characterization of nanoscale and submicron structures. However, materials with complex geometries, such as electrospun fiber networks used for tissue scaffolds, still pose challenges due to the influence of tension and bending modulus on the response of the suspended structures. Here we report mechanical measurements on el...

Steel angle sections are frequently employed in bracing systems or truss structures as single members built-up members. Angles may be coupled back-to-back to create Tee cruciform cross-sections. These sensitive torsional and flexural-torsional buckling due the cross-section shape fact that axial force not applied at shear centre. In this work, a comprehensive numerical investigation of behaviou...

We analyze the coherent dynamics of optically excited alkenes in a fully correlated 3d tight-binding model with extended Hubbard interactions. The scenario that emerges is that the steric repulsive interactions are the driving force behind ultrafast cis-trans photoisomerizations. This resolves the apparent discrepancy between values for the torsional stiffness obtained from band-structure poten...

The present paper studies the possibility of propagation of torsional surface waves in an inhomogeneous anisotropic layer lying between two heterogeneous half-spaces (upper and lower half-space). Both the half-spaces are assumed to be under compressive initial stress. The study reveals that under the assumed conditions, a torsional surface wave propagates in the medium. The dispersion relation ...

INTRODUCTION: The treatment of early onset scoliosis with posterior hook constructs and fusion is often complicated by the crankshaft phenomenon, which is the gradual increase in rotational deformity due to continued anterior growth in the presence of a solid posterior fusion. The combination of a posterior hook construct and an anterior fusion is considered the gold standard for prevention of ...