This paper presents results of evolutionary minimisation of peak-to-peak value of a multi-tone signal. The signal is the sum of multiple tones (channels) with constant amplitudes and frequencies combined with variable phases. An exemplary application is emergency broadcasting using widely used analogue broadcasting techniques: citizens band (CB) or VHF FM commercial broadcasting. The work presented illustrates a relatively simple problem, which, however, is characterised by large combinatorial complexity, so direct (exhaustive) search becomes completely impractical. The process of minimisation is based on genetic algorithm (GA), which proves its usability for given problem. The final result is a significant reduction of peak-to-peak level of given multi-tone signal, demonstrated by three real-life examples.

The production of thin-walled castings with wall thickness in the range of 1.5 to 3 mm and below requires the development of insulation

moulding sands and/or core materials. The test has been taken to develop these kind of materials. The study included a description of their

thermophysical properties. Authors described problems related to the heat flow in the casting-mould system, i.e. mathematically described

the main dependence of heat give-up during crystallization of the casting. The influence of the content of polyglicol on the thermophysical

properties of the mould with gypsum and cement binder was examined. Using the ATD method determined were the increments ΔT1 and

ΔT2 describing the temperature changes in the mould during crystallization of hypoeutectic alloy of AlSi6 and the temperature difference

between casting material and mould during the crystallization. In the considered range of technological parameters a description of the

heat flow kinetics was given.

Until now, the mould sand in general use in the foundry industry are based on bentonite, which resulted from the fact that a good recognition properties and phenomena associated with this material. Come to know and normalized content of montmorillonite and carbonates and their important role in the construction of bentonite, and mass properties of the participation of compressive strength or scatter. Halloysite is widely used in industry and beyond them. However, little is known about its use in the foundry in Poland and abroad. This article presents preliminary research conducted at the Foundry Department of Silesian University of Technology on this material. Will raise the question of the representation of this two materials, which contains information connected with history and formation of materials, their structure and chemical composition. In the research, the results of compressive strength tests in wet masses of quartz matrix, where as a binder is used halloysite and bentonite in different proportions.

This paper presents numerical two-dimensional results for fine-grained concrete under quasi-static three-point bending at meso-scale. Concrete was modelled as a random heterogeneous three-phase material. The simulations for notched concrete beams were carried out with the standard finite element method using an isotropic damage constitutive model enhanced by a characteristic length of micro-structure by means of a non-local theory. The effect of the volume fraction, shape, size, statistical distribution and stiffness of aggregate was analysed. Moreover, the effect of the bond thickness, notch size and characteristic length of micro-structure on the material behaviour was numerically investigated. The FE results were compared with own laboratory test results and other meso-scale calculations for three-phase concrete elements.

The paper presents an analysis of the influence of elevated temperature on thin-walled purlins restrained by sheeting. In the first part of the study the bearing capacity of purlins cooperating with sheeting is examined in normal and elevated temperature based on European Standards. Next, special attention is paid to creating a numerical FEM model of the restrained purlins in Abaqus program taking into account different materials properties with respect to temperature increase.