The characteristics of phonons, i.e. linearized normal modes of vibration, provide important insights into many aspects of crystals, e.g. stability and thermodynamics. In this paper, we use the Objective Structures framework to make concrete analogies between crystalline phonons and normal modes of vibration in non-crystalline but second derivatives is block-circulant. The block-circulant natur...

PURPOSE To describe the fluidic events that occur in a test chamber during phacoemulsification with longitudinal and torsional ultrasound (US) modalities. SETTING Pasteur Ophthalmic Clinic Phacodynamics Laboratory, Santiago, Chile, and Nanyang Technological University, Singapore. DESIGN Experimental study. METHODS Ultra-high-speed videos of a phacoemulsifying tip were recorded while the t...

Abstr&---A general valence force field for secondary chlorides has been refined which includes torsional force constants based on assignments of low frequency modes in model compounds. This force field also incorporates force constants related to observed intermolecular interactions. The good agreement between observed and calculated frequencies indicates that this force field will be useful in...

We use a simple toy-model to discuss global MHD modes of a neutron star, taking into account the magnetic coupling between the elastic crust and the fluid core. Our results suggest that the notion of pure torsional crust modes is not useful for the coupled system, all modes excite Alfvén waves in the core. However, we also show that the modes that are most likely to be excited by a fractured cr...

We introduce the torsional network model (TNM), an elastic network model whose degrees of freedom are the torsion angles of the protein backbone. Normal modes of the TNM displace backbone atoms including C(β) maintaining their covalent geometry. For many proteins, low frequency TNM modes are localized in torsion space yet collective in Cartesian space, reminiscent of hinge motions. A smaller nu...

A parameter study is presented to determine effects of planet gear design parameters on the global modal behaviour planetary geared rotor systems. The sensitivity analysis conducted using a three-dimensional dynamic model system for number gears, mistuning, mass mesh stiffness and speed. These have varying impacts both natural frequencies mode shapes, therefore vibration modes determined by com...

introduction: this study investigated the fatigue and fracture modes of race and protaper rotary instruments. materials & methods: fatigue resistance was evaluated by rotating the files 30 ° or 60 ° and with 2 or 5mm radius of curvature. race taper 06 size 25 and protaper f1 files (n=40) were used. the number of rotations to failure was analyzed by two-way anova and independent sample     t-tes...

We demonstrate an all-fiber tunable polarization filter with high coupling efficiency based on acousto-optic coupling between two optical polarization modes of the LP(01) mode propagating in a highly birefringent single mode optical fiber. An over-coupling between the two polarization modes is realized over the wavelength range from 1530 nm to 1610 nm using traveling torsional acoustic wave. Th...