Investigation of the nonunifcrmity of the acoustic properties of the human tibia

Mechanics of Composite Materials - A method is proposed for determining the propagation velocity and coefficient of attenuation of ultrasonic vibrations in both the whole diaphysis of the human...     

Love waves of SH type in an inhomogeneous transversely isotropic elastic medium

The asymptotics of high-frequency Love waves, which are analogous to transverse surface SH waves, is considered for a special type of anisotropy (transverse isotropy) of elastic media. The wave field is represented as a sum of the space-time (ST) caustic expansion and two additional ST ray series for faster (relative to the transverse surface wave) body waves, decaying exponentially with depth. Near the surface, the coefficients of the ST caustic and ray series, as well as the eikonals of waves, are determined in the form of expansions in a small parameter, which characterizes the proximity of the caustic of the ray field to the surface. With regard for the specific structure of the elasticity tensor of a transversely isotropic medium, the surface is treated as a plane. Interrelations between the parameters of elasticity, which are consistent with the conditions of the positivity of the elastic deformation energy and provide for the origination of the surface waves considered, are obtained.Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 239, 1997, pp. 243–262.This work was supported by the Russian Foundation for Basic Research under grant No. 96-01-00666.     

A general model of metal underpotential deposition in the presence of thiol-based additives based on an in situ STM study

Bis(3-sulfopropyl)disulfide (SPS) is a common additive in commercial copper electroplating baths. We have studied the influence of SPS on Cu underpotential deposition (UPD) on a Au(111) single crystal surface by means of cyclic voltammetry (CV) and electrochemical scanning tunneling microscopy (EC-STM). By combining our results with the results from the literature we propose a model that describes different stages of Cu UPD in the presence of SPS. Further analysis shows that our model is also applicable to a more general case of UPD of different metals, e.g. Cu and Ag, on a thiol-modified single-crystal surface, where the bond between the substrate and the thiol is adatom mediated. In addition, we have verified our model by in situ observation of the lifting of the Herringbone reconstruction on the Au(111) surface by Cu UPD.     

Dispersion properties of nonstationary SV Rayleigh waves near the surface of an inhomogeneous elastic body

The physical characteristics of the surface of nonstationary SV Rayleigh waves are studied and formulas are obtained for the phase and group velocities (as functions of time and the observation point on the surface) of the Rayleigh waves. These formulas are in accord with the familiar formulas for the phase and group velocities in the stationary case.Translated from Zapiski Nauchnykh Seminarov Leningradzkogo Otdeleniya Matematicheskogo Instituta im. V. A. Steklova, AN SSSR, Vol. 173, pp. 172–179, 1988.