Edward Włodarczyk

Static and dynamic ductility of copper and its sinters

In order to raise the sensitivity of microwave electron-paramagnetic-resonance (EPR) spectrometers, it is proposed to use a piece of ferroelectric material as an additional resonator. The method has been tested using the RE-1307 microwave EPR spectrometer and a pulsed microwave spectrometer. The possibility of raising the signal-to-noise ratio when using ferroelectric resonators of rectangular-parallelepiped and spherical shape has been considered. For a potassium-tantalate ferroelectric resonator of rectangular-parallelepiped shape, the signal-to-noise ratio has been raised by a factor of 16 at 331 K and by a factor of 10 at 292 K. In the pulse experiment, the presence of the ferroelectric resonator permits a reduction in microwave power, required for sample saturation, by a factor of 50 at 50 K.

Experimental Analysis of Local and Average Dynamic Longitudinal Engineering Compressive Strains in Ductile Porous Rod After the Taylor Direct Impact Experiment

The recent experimental method for determining dynamic longitudinal engineering compressive local strain, εl (x), (x is Lagrangian coordinate) and average one, εa, in a ductile porous rod, plastically deformed by Taylor direct impact experiment (Taylor DIE) is presented in this paper. Analysis of strain distribution, εl (x), along axis of the rod was performed by means of this method. There are two essential singularities in this distribution, namely: the first – the maximum compressive strain, εl max, there is in a near of the striking end rod, but it does not locate on the target face; and the second – at high loading (impact velocity), value of the maximum, εl max, decreases together with increasing of initial rod porosity, inversely than at static loading. The values of the strains εl (x) and εa are limited by the impact velocity U. Influence of the moderate porosity (e.g. for copper – ∆sa < 20%) on values of the εl (x) and εa is in the order of several percent and it may be neglected.

Investigation of laser radiation extinction in pyrotechnic aerodispersive clouds at 1.06-um and 10.6-um wavelengths

In the paper an extinction of the laser radiation at 1.06 and 10.6 micrometers wavelengths in aerosol clouds generated by burning of pyrotechnic mixtures is investigated. The results of transmission measurements and evaluated values of volume attenuation coefficient are presented for a few kinds of chloro-organometallic smoke-producing agents. An estimation of the laser ranging diminution by the pyrotechnic-derived smoke was carried out.