The purpose of this paper is to clarify the temporary threshold shifts in fingertip vibratory sensation produced by hand-transmitted vibrations that have the same equivalent tool vibration levels according to the JIS B 4900 determination method. The JIS B 4900 standard is based on vibration exposure dose values. Therefore, even though the vibration exposure pattern is varied, the severity of vi...

vibration in the air slide tables of ultra precision machines prevents gaining accuracies within nanometer level. in this work, dissimilar types of internal vibration including small vibrations and pneumatic hammers have been tested and some measures have been offered to reduce their effects. this paper has also proceeded to the vibration tests on the air slide tables built with different numbe...

today there are different vibration isolators used in industries according to the weight and excitation frequency of the machines which have vibration. one of them is air spring which is in two types: convoluted air spring and membrane air spring. convoluted air springs are used to control vibrations in low frequency (usually lower than 10 hz) and the membrane ones are used in high frequency (u...

The laser-polarization effects on nonadiabatically coupled π-electron rotation (ring current) and molecular vibration have been theoretically analyzed for aromatic molecules with quasi-degenerate excited states irradiated by an ultrashort laser pulse of arbitrary polarization. We first derived general formulations of the coherent electronic wave packet and expectation value of electronic angula...

We study the electronic lifetimes in molecular junctions using the Keldysh nonequilibrium Green function (NEGF) model. It is found that two characteristic time scales which govern the electron tunneling phenomena. One is the electronic lifetime in which electronic energy in the molecular electronic state dissipates into the right/left electrode or vibrational mode, the other is the residence ti...

Combined use of IR, Raman, neutron scattering and fluorescence measurements for porphycene isolated in helium nanodroplets, supersonic jet and cryogenic matrices, as well as for solid and liquid solutions, resulted in the assignments of almost all of 108 fundamental vibrations. The puzzling feature of porphycene is the apparent lack of the N–H stretching band in the IR spectrum, predicted to be...

We use empirical molecular dynamics technique to investigate the low-energy vibrations in a large 4096 atom model for pure amorphous silicon and a set of models with voids of di€erent size based on it. Numerical vibrational eigenvalues and eigenvectors for our models are obtained by exact diagonalization of their dynamical matrices. Our calculations show that localized low-energy vibrational ex...

structural dynamic parameters: natural period, shape modes and damping ratio of vibration, play a decisive role on the seismic behavior of those structures. there are several methods for determining of the structural dynamic parameters, such as: free vibration, ambient vibration and force vibration tests. in this research the structural response of a three-story building (the natural frequencie...

In soft matter physics novel kinds of “cluster phases” have attracted considerable attention recently. These phases are observed, for instance, in systems in which particles interact via bounded, purely repulsive potentials that originate from the effective interactions between soft colloids, such as dendrimers. At sufficiently high densities these particles overlap, thereby forming clusters wh...