Electromagnetic induction of ultrasonic waves is restricted to conducting materials – like eddy current testing – because it involves inducing eddy currents in the surface of the part by a nearby coil of wire. A magnetic field supplied by a nearby magnet interacts with this eddy current to produce a mechanical force on the surface to excite ultrasonic vibrations. The same configuration of coil ...

this paper deals with new method for designing the tuned mass dampers (tmd) with considering both transient and steady state responses, simultaneously. this formulation is presented for undamped vibrations. for this purpose, the absolute value of the structural displacement ratio is minimized numerically. this procedure leads to optimum value of tmd's specifications. for numerical verification,...

The purpose of this mini-review is to outline diversity of chest wall vibrations, specify biomechanical peculiarities and point out a few problems crucial for development of diagnostic and therapeutic applications of chest wall vibrations. The review considers two types of chest wall vibrations: spontaneous, induced by breathing, and forced (or artificial), induced by external vibration forces....

The non-linear electro-ultrasonic spectroscopy was used as a non-destructive testing method for the polymer based and cermet thick film resistors evaluation. We carried out the correlation between this method and standard testing methods as noise spectroscopy and the third harmonic voltage measurements. The measuring set-up with the ultrasonic transducer working on the frequency range 10 kHz to...

The purpose of this paper is to study the effect of presence of fluid within and around a poroelastic circular cylindrical shell of infinite extent on axially symmetric vibrations. The frequency equation each for a pervious and an impervious surface is obtained employing Biot’s theory. Radial vibrations and axially symmetric shear vibrations are uncoupled when the wavenumber is vanished. The pr...

the use of bio-ethanol as an alternative diesel engine fuel is rapidly increasing. bio-ethanol is mixed with diesel fuel at different ratios and used in ci and si engines. since vibrations have direct effects on users and engine components, for this reason analysis of vibration resulting from combustion in ci engines is very important. in this study, evaluation of vibration was performed for bo...

It has been found that ultrasonic treatment of diamond nanopowders contributes to surface cleaning due the removal non-diamond carbon and impurities from boundary nanodiamond grains (from 0.4 0.32 % for ASUD-99 0.67 0.55 ASUD 75, respectively). does not affect total sorption volume values specific studied samples do change, but it changes composition groups on nanoparticles, which its hydrophil...

The formation of human life conditions in residential areas depends on the state ecological balance these territories, which, turn, relays influence various natural and anthropogenic environmental factors. From a practical point view, this is increasingly becoming cumulative or even complex. article discusses need to create system integrated (aggregate) monitoring areas, providing visualization...