The analysis of phenomena related to gas transport in hard coal is important with regard to the energetic use of coal bed methane (CBM), the reduction of greenhouse gas emissions to the atmosphere (CO2) and the prevention of natural hazards such as methane hazards and gas and rock outbursts. This article presents issues concerning the feasibility and scope of applying the unipore and bidisperse diffusion models to obtain knowledge concerning the kinetics of methane sorption and its diffusion in the carbon structure, depending on its petrography. Laboratory tests were carried out on coal samples which varied in terms of petrography. Quantitative point analyses were carried out, based on which content of groups of macerals was determined. The degree of coalification of coal samples was also determined based on measurements of vitrinite reflectivity R0 and the volatile matter content Vdaf. Sorption kinetics were also investigated, and attempts were made to adjust the unipore and bidisperse models to the real sorption kinetic courses. This allowed the identification of appropriate coefficients controlling the course of sorption in mathematical models. An attempt was also made to assess the possibility of applying a given model to properly describe the phenomenon of methane sorption on hard coal.

The paper presents the application of the IMGAMO (immune game theory multiobective algorithm) in the optimal design of electrothermal microactuators. Several numerical tests on the mathematical benchmark test functions were performed, showing the superiority of the IMGAMO, when a large number of criteria are considered, in comparison to other multiobjective optimizers. A parametric numerical model of an electrothermal microactuaror was developed and verified. Six functionals, which depend on various thermal and mechanical quantities of the microactuator, were proposed, formulated and numerically implemented. These functionals represent real requirements asked of microactuators. The boundary-value problem of an electro-thermo-mechanical field was solved multiple times during the course of optimization by way of the finite element method (FEM). A numerical example of multiobjective optimization of chevron-type electrothermal actuators is included in the paper. Representation of the multi-dimensional Pareto fronts by means of scatter plot matrices, aided by self-organizing maps (SOMs), is presented. The novel method of selecting interesting, compromise-solutions is proposed and described.

Lightweight-focused design often leads to a problematic vibration susceptibility of designed components. To reduce potential environmental and health risks, excessive vibrations have to be mitigated preferably through lightweight-compatible solutions. The presented studies aim at the establishment of almost weight-neutral solutions for adaptive tuning of the dynamic behaviour of lightweight components. The proposed unique actuating principle is based on structural cavities generating evanescent deformations when supplied with fluidic medium. These cavities encapsulate compressible, viscoelastic elements which are combined with the surrounding layers and operate according to an extended principle of Constrained Layer Damping. The evanescent morphing is used to deliberately alter the geometrical and material properties of the viscoelastic elements through their compression in order to achieve a damping and stiffness capacity adaptation. The analysed Compressible Constrained Layer Damping (CCLD) object is configured as a three layered beam consisting of the load-bearing structure as well as constraining layer and compressible viscoelastic layer. The main studies were conducted using a developed finite-element model. Herein, the geometrical, material and load property range has been parametrised so that generalised conclusions about the CCLD dynamic behaviour could be drawn. The deformation kinematics of the CCLD under combined loads resulting from static tension and flexural vibrations has been analysed. Furthermore, the assessment of the dynamic behaviour adaptation potential for different compressible viscoelastic materials was carried out. The goal of this study was on the one hand to determine a feasible initial configuration of the CCLD for its successful application and on the other hand the assessment of its damping efficiency.

In this paper a problem of structural optimization of an aerofoil is examined. Authors' implementation of a multiobjective optimization algorithm based on differential evolution and elements of game theory is used as an optimization tool. Real requirements asked of aerofoil systems, described by mathematical functions are used as optimization objectives. Values of these functionals are determined numerically multiple times during the course of optimization. On the basis of a wing of unmanned aerial vehicle (UAV), a parametric numerical model is built. The inner geometry of the wing is described by 24 design variables and is subject to the optimization, while the outer geometry doesn't change.

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