The aim of this work was to study the effect of different methods of multi-walled carbon nanotubes (MWCNTs) dispersion, and their influence on the microstructure and properties of aluminium alloy matrix composites produced using the powder metallurgy techniques, such as powder milling/mixing and hot extrusion. The main problem in the manufacturing of nanocomposites is the homogeneous distribution of MWCNTs in the metal matrix. To achieve their proper distribution a high-energy and low-energy mechanical milling, using a planetary ball mill, and mixing, using a turbulent mixer, were applied. Studies have shown that composite materials prepared using milling and extrusion have a much better dispersion of the reinforcing phase, which leads to better mechanical properties of the obtained rods. The low-energy mechanical mixing and mixing using the turbulent mixer neither change the powder morphology nor lead to adequate dispersion of the carbon nanotubes, which directly affects the resulting properties.

The purpose of the following paper is to demonstrate the thought processes behind the design and verification of the electric race car structure. The developed structures were modelled in the CAD environment of Siemens NX 10.0 program. The main aim of inventing different solutions was to improve the characteristics of the car. These characteristics include, for instance, aerodynamic drag and gearbox friction. After the framework was established, work on the shape of the body began. The body alterations are understood as reducing the overall width of the car, decreasing the cross-section area and tilting the sides of the sheathing in order to minimise the generated aerodynamic drag. All elements were verified computationally to check whether they can be improved by altering their geometry. Main condition upon which every modification was made was to switch from the previous belt transmission to the newly designed chain transmission. The most significant change in the frame was reducing the back-section width in order to accommodate the chain transmission. Furthermore, it was required to enable easy switching of the transmission from chain to belt. Next step of the project was adding the mechanism enabling the tilting of wheels rotational axis in relation to the ground.

The paper presents a mirror cover manufacturing process, focused on geometry optimization by reducing air drag for Silesian Greenpower electric car. Silesian Greenpower is a student’s interfaculty project, of which aim is to design, build, and race an electric vehicle. Each car is equipped with the same motor and batteries. Target is to finish as many laps as possible during a set amount of time. Major development takes place in aerodynamics to decrease movement resistance. In the presented development process, computer-aided design software was used to create part concepts and then aerodynamics simulation was carried out to determine quality of each design. The influence of chosen geometric parameters was analysed and discussed in the article. The final concept was manufactured using 3D-printing technology with ABS - acrylonitrile butadiene styrene, because of good mechanical properties but also availability and relatively low cost. 3D˗printed elements were verified experimentally using smoke stream generator.

In the article the problem of the road safety in Bytom based on analysis of the period 2013 – 2017 is presented. The types of traffic incidents and their classification are specified. Selected issues that have a particular impact on the safety level of road users, such as the number of road accidents, the reasons for their occurrence, the perpetrators of accidents and their consequences, are described. Actions and initiatives taken to improve safety were discussed. In addition, the paper evaluates the effects of measures to improve road safety introduced in Bytom