This paper discusses the adsorption of Direct Orange 26 azo dye on sunflower husk - an agricultural waste product. During the study, sorption kinetics and equilibrium as well as sorption capacity of the husk were investigated. The adsorption kinetics was analyzed using pseudo-first and pseudo-second order equations, which indicated a chemical sorption mechanism. The sorption equilibrium was approximated with the two-parameter Freundlich and Langmuir equations and the three-parameter Redlich-Peterson equation. The main experiments were carried out in a laboratory adsorption column under different process conditions. Experimental data were interpreted with the Thomas model, based on the volumetric flow rate, initial composition of the feed solution and mass of the adsorbent. The results of modeling the adsorption equilibrium, adsorption kinetics and adsorption dynamics were evaluated statistically.

The author claims that Marx’s ideas have succeeded, the proletariat has been victorious in the class conflict but the victory is completely different from what Marx has expected. The vision of the proletariat state ended up in a total failure. The vestiges of Marx’s proposal testify to complete inapplicability of his main ideas to the circumstances of the contemporary world. The concept of a state managed by the proletariat class turned out to be defective. The ownership of the means of production has failed. The concept of private property defended itself and has even been strengthened. And where a public ownership won the upper hand, as in State Treasury, it turned out to be institutional and not collective. Moreover, the state interferes more and more vigorously in private businesses and their activities. On the other hand, however, the proletariat succeeded in the area of employment law where it won some durable legal guarantees. Thus Marx correctly perceived certain needs of the proletariat but proposed inapt solutions to them.

This document analyses qualities of methods used for testing dynamical parameters of Digital-to-Analog Converters (DAC) using a multi-frequency signal. As the source for these signals, Amplitude Modulated (AM) and Frequency Modulated (FM) signals are used. These signals are often used in radio engineering. Results of the tests, like Effective Number of Bits (ENOB), Signal-to-Noise and Distortion (SINAD), are evaluated in the frequency domain and they are compared with standard results of Sine Wave FFT test methods. The aim of this research is firstly to test whether it is possible to test a DAC using modulated signals, secondly to reduce testing time, while estimating band performance of DAC.