Increasing the Accuracy of Reproduction of Pressure by Means of the Ukrainian Secondary Standard of the Unit of Pressure

The estimated components of the error in the determination of the effective area of a measuring piston-cylinder assembly of a piston manometer with a non-sealed piston are reported. Such manometers are incorporated into the secondary standard of the unit of pressure.     

Fluxmeter for Measuring the Magnetic Susceptibility of Stainless Steel Samples

A portable device for measuring very low levels of the magnetic susceptibility of stainless steel is described. Taking into account that the magnetic susceptibility of stainless steel decreases with an increasing external magnetic field, the detector of the device is supplied with a small-size magnet producing a magnetic field of about 0.15 T at the measurement point. The device sensitivity is 0.001.     

Developing an integrated technique to evaluate crack formation in reinforced concrete under uniaxial compression

Regularities of changes in the parameters of acoustic and electromagnetic emission and of forced electric response from reinforced concrete under uniaxial compression have been studied. It has been established that the main diagnostic criteria of the onset of crack formation are the emergence of high-amplitude signals of acoustic and electromagnetic emission; considerable changes in the spectral composition of the electric signal; a decrease in the maximum coefficient of correlation between the spectra of signals registered at different stages of loading as compared with the spectrum of the signal prior to loading; and hopping shift of the frequency at which the maximum correlation coefficient is observed. On-line monitoring and periodic inspection can be used to assess the onset of crack-formation processes.     

Adhesive contact quality diagnostics in compisite materials with a usage of mechanoelectrical transformatios phenomenon

In the Tomsk Polytechnic University during the set of years the development of the composite dielec-tric meterials structural and mechanical characteristics nondestructing testing is conducted with a usage ofmechanoelectrical transformatios phenomenon[1].In the most of composite materials the weakest part are the adhesive contact zones of the components ,composingthis composite .Therefore ,the quality of this contact will determine the mechanical properties ofsuch material .Thereis al ways a …     

Investigation of the relationship between the parameters of electric response to impact excitation of porous heterogeneous materials and variations in their strength under the conditions of cyclic freezing-defreezing

A decrease in the strength of cement-sand specimens due to cyclic alternating-sign temperature excitation is shown to yield a shift of the principal maximum and the entire spectrum of the electric response to an impact excitation towards lower frequencies, spectrum broadening, and deterioration of the spectral maxima quality factor.     

The effect of the filler particle size on the efficiency of mechanoelectrical transformations in concretes

The mechanoelectrical transformations in concretes were studied using the method of physical modeling. It is demonstrated that the filler particle size has a decisive effect on the efficiency of mechanoelectrical transformations in concretes. Dependence of the amplitude of electromagnetic response to shock excitation on the surface area of inclusions is determined.     

Electromagnetic diagnostics of composite materials

The large volume of researches was carry out in order to interrelate parameters of mechanoelectrictransformations [ MET] with mechanical characteristics of composites affected MET effectiveness and tostudy the main factors affecting METeffectiveness .Gain-frequency characteristics of electromagnetic response oni mpact excitation of composites ,consis-ting of cement and aggregate ,depend onlocation the last in the sample[1].It was determinedthat magnitude of electromagnetic responseincreases…