BACKGROUND Seismocardiography is the noninvasive measurement of cardiac vibrations transmitted to the chest wall by the heart during its movement. While most applications for seismocardiography are based on unidirectional acceleration measurement, several studies have highlighted the importance of three-dimensional measurements in cardiac vibration studies. One of the main challenges in using t...

The mono-frequency as well as multi-frequency vortex-induced vibrations of a tensioned beam of aspect ratio 200, immersed in a linear shear flow at Reynolds number 330 and free to move in both the in-line and cross-flow directions, are studied by means of direct numerical simulation. The structural responses are composed of mixed standing–traveling wave patterns. We observe a switch between mon...

In this paper, the author extends existing analysis methods for bowed string vibration to that involving dynamics of a soundbox and neck instrument. Almost all components instrument such as strings, nut, tuning pegs, neck, soundbox, bridge are physically modeled numerically analyzed by finite element method, thereby yielding an equation motion total multi-degree-of-freedom (MDOF) system. Then, ...

Pump dynamic operational conditions result in extreme transient events that can enhance the response of piping networks. The predominant transients during rapid startup and shutdown are mainly studied for centrifugal pumps scarce reciprocating pumps. Our study extends conventional steady-state analysis to include effect pump loading on pulsatile flow-induced acoustics vibrations a complex netwo...

Quantum-mechanical scattering involving continuum states coupled to a scatterer with discrete spectrum gives rise Fano resonances. Here we consider scatterers that possess internal vibrational degrees of freedom in addition states. Entanglement between the scattered excitation and modes complicates analytical numerical calculations considerably. For example one-dimensional develop multichannel ...

A new formulation for the non-dimensional dynamic influence function method, which was developed by the authors, is proposed to efficiently extract eigenvalues and mode shapes of clamped plates with arbitrary shapes. Compared with the finite element and boundary element methods, the non-dimensional dynamic influence function method yields highly accurate solutions in eigenvalue analysis problem...

Title of dissertation: AN EMBEDDED-BOUNDARY FORMULATION FOR LARGE-EDDY SIMULATION OF TURBULENT FLOWS INTERACTING WITH MOVING BOUNDARIES Jianming Yang, Doctor of Philosophy, 2005 Directed by: Assistant Professor Elias Balaras Department of Mechanical Engineering A non-boundary-conforming formulation for simulating transitional and turbulent flows with complex geometries and dynamically moving bo...

air spindles are one of the main elements of precise machine tools. vibration of these spindles is one of the vital issues necessary for investigation. among parameters which influence air spindle vibrations are rotational speed, compression air method, input nozzle diameter, air gap pressure. in this study using ansys, the effects of air gap thickness on air spindle vibrations have been invest...

We propose a method of driving the vibrations of normal modes of a target molecule into coherence using stimulated Raman scattering. In concert many vibrations can produce a larger anti-Stokes signal than a single vibration. The same illumination does not drive other molecules to have coherent vibrations so that these molecules produce a weaker signal. We investigate how target and confounder m...

Farmers experience whole-body vibrations when they drive tractors. Among the various factors that influence the vibrations to which the driver is exposed are terrain roughness, tractor speed, tire type and pressure, rear axle width, and tractor seat height above the ground. In this paper the influence of tractor seat height above the ground on the lateral vibrations to which the tractor driver ...