Polystyrene-based nanocomposites with different fillers: fabrication and mechanical properties

The paper presents a comprehensive analysis of elastic properties of polystyrene-based nanocomposites filled with different types of inclusions: small spherical particles (SiO2 and Al2O3), alumosilicates (montmorillonite, halloysite natural tubules and Mica) and carbon nanofillers (carbon black and multi-walled carbon nanotubes). Composites were fabricated by melt technology. The analysis of composite melts showed that the introduction of Montmorillonite, Multi-walled carbon nanotubes, and Al2O3 particles provided an increase in melt viscosity by an average of 2 to 5 orders of magnitude over the pure polystyrene. Block samples of composites with different filler concentrations were prepared, and their linear and nonlinear elastic properties were studied. The introduction of more rigid particles led to a more profound increase in the elastic modulus of the composite, with the highest rise of about 80% obtained with carbon fillers. Carbon black particles provided also an enhanced strength at break of about 20% higher than that of pure polystyrene. The nonlinear elastic moduli of composites were shown to be more sensitive to addition of filler particles to the polymer matrix than the linear ones. The nonlinearity coefficient $\beta$ comprising the combination of linear and nonlinear elastic moduli of a material demonstrated considerable changes correlating with changes of the Young's modulus. The absolute value of $\beta$ showed rise in 1.5-1.6 times in the CB- and HNT-containing composites as compared to that of pure PS. The changes in nonlinear elasticity of fabricated composites were compared with measurements of the parameters of bulk nonlinear strain waves in them. Variations of wave velocity and decay decrement correlated with observed enhancement of materials nonlinearity

Testing the time series for stationarity in systems for processing of experimental data

We propose a criterion for estimating the experimentally obtained time series for stationarity. The criterion makes it possible to automatically choose in real time the corresponding process of further processing and analyzing the recorded information and, correspondingly, improve reliability of the spectral estimates of a signal. The step-by-step estimation algorithm is presented. © 2013 Springer Science+Business Media New York

Experimental evaluation of inhomogeneous nonlinear refractive index distribution using time-resolved inline digital holography

publishedVersionNon peer reviewe

Investigation of Nonlinear Optical Properties of Quantum Dots Deposited onto a Sample Glass Using Time-Resolved Inline Digital Holography

We report on the application of time-resolved inline digital holography in the study of the nonlinear optical properties of quantum dots deposited onto sample glass. The Fresnel diffraction patterns of the probe pulse due to noncollinear degenerate phase modulation induced by a femtosecond pump pulse were extracted from the set of inline digital holograms and analyzed. The absolute values of the nonlinear refractive index of both the sample glass substrate and the deposited layer of quantum dots were evaluated using the proposed technique. To characterize the inhomogeneous distribution of the samples’ nonlinear optical properties, we proposed plotting an optical nonlinearity map calculated as a local standard deviation of the diffraction pattern intensities induced by noncollinear degenerate phase modulation.publishedVersionPeer reviewe

The mobile experimental complex for studying of electromagnetic fields generated in a wide frequency range in an industrial environment

© 2014 IEEE. The mobile experimental complex was created by the authors for research of the electromagnetic (EM) fields generated by the electrical equipment and the elements of electric power systems in a wide frequency range. The description of the architecture and composition of the equipment is given, and its functionalities are considered. The complex is used to monitor the EM environment of objects for the purpose of solving of problems of electromagnetic compatibility (EMC). The results of monitor studies of the EM environment at two energy and industry sites are given

The mobile experimental complex for studying of electromagnetic fields generated in a wide frequency range in an industrial environment

© 2014 IEEE. The mobile experimental complex was created by the authors for research of the electromagnetic (EM) fields generated by the electrical equipment and the elements of electric power systems in a wide frequency range. The description of the architecture and composition of the equipment is given, and its functionalities are considered. The complex is used to monitor the EM environment of objects for the purpose of solving of problems of electromagnetic compatibility (EMC). The results of monitor studies of the EM environment at two energy and industry sites are given

The mobile experimental complex for studying of electromagnetic fields generated in a wide frequency range in an industrial environment

© 2014 IEEE. The mobile experimental complex was created by the authors for research of the electromagnetic (EM) fields generated by the electrical equipment and the elements of electric power systems in a wide frequency range. The description of the architecture and composition of the equipment is given, and its functionalities are considered. The complex is used to monitor the EM environment of objects for the purpose of solving of problems of electromagnetic compatibility (EMC). The results of monitor studies of the EM environment at two energy and industry sites are given

Testing the time series for stationarity in systems for processing of experimental data

We propose a criterion for estimating the experimentally obtained time series for stationarity. The criterion makes it possible to automatically choose in real time the corresponding process of further processing and analyzing the recorded information and, correspondingly, improve reliability of the spectral estimates of a signal. The step-by-step estimation algorithm is presented. © 2013 Springer Science+Business Media New York