The paper attempts to determine the impact of fuel impurities on the spark discharge energy and the wear of the spark plug electrode. Spark plugs were analyzed in two typical configurations of the ignition system. A number of tests were conducted to determine the wear of the spark plug electrode exposed to different types of impurities. The spark discharge energy for new and worn spark plugs was determined through calculation.

The paper discusses the modelling of magnetic coupling in ignition coils by fractional differential equations. The use of fractional-order coupling allows us to consider the losses caused by the non-linearity of the ferromagnetic core of the ignition coil and obtain the waveform of the ignition coil’s secondary voltage closest to the values obtained experimentally.

The paper analyses the possibilities of treating the ignition cable in the internal combustion engine as a distributed parameter system. It presents the experimental verification of computer simulations of signal propagation generated by ignition systems in the ignition cables, modelled by the distributed parameter system. The tests conducted to determine the wave parameters of ignition cables, as well as the results of numerical simulations and their experimental verifications, are presented. It is concluded that the modelling of the ignition cable by means of a long line gives positive results that can be used for the design of a spark plug with impedance equal to wave impedance of the ignition cable.

The application of solid-state light sources in luminaires creates a new quality in illumination design works. In a confrontation with a commonly used but relatively unattractive flood method, the use of small-size luminaires allows one to present an illuminated architectural object in a more attractive way in the evening and at night. In this case, it is possible to apply the principles of illumination described in the literature, especially the principle of height amplification and the principle of depth amplification. The conceptual work of illumination with the use of a large number of small-size luminaires does not require the use of supporting graphical tools, but the specification of actual lighting equipment using only polygonal samples in this case is not possible. The paper presents selected issues of the key stages of the completed work. Using specialized computer software, a geometric model of the architectural object has been developed, facade materials have been parameterized, models of small-size illuminating equipment have been selected and, finally, calculations of luminance distribution on illuminated surfaces have been carried out. As a result of computer work, luminance distributions and photorealistic visualizations of illuminations from defined main directions of observation were obtained. The Lubomirski Palace in Przemysl is an example of the architectural object indicated for detailed works.

This paper presents equivalent impedance and operator admittance systems for fractional order elements. Presented models of fractional order elements of the type: s ^α L _α and 1/s ^α C _α, (0 α 1) were obtained using the Laplace transform based on the expansion of the factor sign to an infinite fraction with varying degrees of accuracy – the continued fraction expansion method (CFE). Then circuit synthesis methods were applied. As a result, equivalent circuit diagrams of fractional order elements were obtained. The obtained equivalent schemes consist both of classical RLC elements, as well as active elements built based on operational amplifiers. Numerical experiments were conducted for the constructed models, presenting responses to selected input signals.

The article presents selected results of research on improving pedestrian traffic safety. Based on annually-updated accident statistics made available by the police, as well as the new pedestrian traffic regulations in force, detailed work was undertaken to assess the level of visibility of pedestrians by drivers in pedestrian crossing areas. The research was carried out by analyzing several characteristic cases of pedestrian crossings occurring in Poland, in which there was only dedicated lighting for crossings, only street lighting, and a variant of coexistence of both of the above lighting solutions. Illuminance measurements were made in the horizontal and vertical planes of pedestrian crossings, and the results were confronted with the relevant guidelines. The next step involved a complementary measurement of the luminance distribution of the vertical plane containing the pedestrian and a portion of the sub- and super-horizontal background. Visibility pedestrians was considered in positive and negative contrast variants, and was then related to the obtained results of the illumination distribution. The analysis of the results of the study indicated the possibility of limited visibility of pedestrians at the crossings despite the satisfactory results obtained from measurements of the illuminance distribution within the crossings.