Expansion of the analyte concentration range using self-absorption lines

The width of a spectral line in atomic emission spectral analysis with arc radiation sources is, as a rule, much smaller than the hardware function of the spectral device. Thus, the spectral line shape is determined by the hardware function of the spectral device and can be approximated, for example, by the Voigt function. However, when analyzing standard samples with a wide range of element concentrations, the problem of self-absorption often occurs, due to which the analytical line has to be changed, which is not always possible. We propose to modify the Voigt function by adding a factor that describes self-absorption, by analogy with the Bouguer-Lambert law. The possibility of using the proposed function was evaluated in analysis of standard samples of rocks, ores and sandstones on a Grand-Potok spectral system with a MAÉS analyzer and BLPP-2000 linear photodetector arrays. The use of proposed approximating function is shown to provide an increase in the working range of the calibration curves of Cu 327.3954 nm, Cu 324.7532 nm, Pb 287.3311 nm, Ni 305.0818 nm, and Mo 313.2594 nm by 1 – 3 orders of magnitude.

Improving the efficiency of antennas of MIMO communication systems

The last two decades were marked by increasing of interest in problems of application of the MIMO systems in a radar and wireless communication. Use of the principles of creation of MIMO systems in communication complexes allows increasing the capacity of channels and speed of information transfer due to increase in number of the transferring and reception antennas. In the report questions of modernization of antennas of the wearable mobile communication devices allowing to reduce correlation of channels and to increase spectral system effectiveness of communication are considered. Results of a research of mutual correlation reduction between two antennas of MIMO system are given. Using method of numerical modelling influence of several options of the decoupling structures on interconnection size between radiators and on their directional patterns were investigated. Comparative results of a pilot study of the model of antennas with the outcome device having the best characteristics and without the decoupling device are presented.

Stabilization of Variable Coefficients Euler-Bernoulli Beam with Viscous Damping under a Force Control in Rotation and Velocity Rotation

This paper investigates the problem of exponential stability for a damped Euler-Bernoulli beam with variable coefficients clamped at one end and subjected to a force control in rotation and velocity rotation. We adopt the Riesz basis approach for show that the closed-loop system is a Riesz spectral system. Therefore, the exponential stability and the spectrum-determined growth condition are obtained.