Abstract In the paper a variant of cyclic production with setups and two-machine cell is considered. One of the stages of the problem solving consists of assigning each operation to the machine on which it will be carried out. The total number of such assignments is exponential. We propose a polynomial time algorithm finding the optimal operations to machines assignment.

The topic of waste incineration/co-incineration is critical, given the increasingly stringent regulations on environmental aspects. The widespread use of polymeric materials generates significant waste, posing an ecological problem. Current regulations mandate a reduction in the landfilling of plastic waste, which should be replaced by recycling, with the possi-bility of exploiting the energy potential due to its high calorific value. The electricity generation in Poland is mainly based on coal, so using polymers as alternative fuels is an important research issue. The research results presented in this paper make it possible to compare the properties of selected waste plastics and coal and their behavior during thermal processes, considering the quality of the gases released. Based on the thermal analyses, a FuzzyTherm model was introduced based on one of the fuzzy logic methods, one of the main artificial intelligence modeling approaches. The model predicts the temperatures corresponding to endothermic and exothermic reactions. The model achieved good accuracy. The maximum relative error between measured and calculated data is lower than 11%. These aspects constitute an innovative element of this paper.

The aim of this study was to present the results of the examinations of the structure and thermomechanical properties of PA6/NanoBent composite. NanoBent composites composed of minerals from the smectite group (mainly montmorillonite) were used for modification of polyamide 6. PA6 composite with content of 1, 3, 5% of NanoBent was prepared in a Theysohn TSK 75-N twin screw extruder. The samples were prepared using the injection technology by means of a Krauss-Maffei KM65-160 C1 injection molding machine. The samples of composites obtained at different injection temperatures and injection mold temperatures were used for the examinations. Degree of crystallinity was examined using the DSC method whereas the material structure was examined with an optical microscope. DSC studies showed a reduction in the value of the degree of crystallinity with the increasing content of nanofiller in the polymer material. The narrowing of the peak was recorded in the DSC thermograms for nanocomposites with greater percentage of the nanofiller. Dynamical properties of polyamide 6 nanocomposite were also determined in relation to temperature and frequency. The samples were bended at frequencies of 1 Hz and 10 Hz over the temperature range from –100°C to 180°C and the heating rate of 2K/min. A significant increase in storage modulus was observed for PA6 samples with the content of 5% of NanoBent obtained at the injection temperature of 270°C and mold temperature of 70°C. Smaller size of spherulites and arrangement of structural elements in clusters along the line of polymeric material flow in the mold cavity at higher contents of NanoBent were observed during structural examinations of the composites.

The aim of the research was to determine the factors defining the growth and development of Lolium perenne and Trifolium repens upon petroleum contamination. The top layer of clay soil contaminated with petroleum products resulting from an oil pipeline failure was collected for the tests. The control was the same type of uncontaminated soil with the addition of, under laboratory conditions, tissue paper. The research was conducted in two stages. The first concerned the germination process and seedlings parameters (Petri dishes). The germination energy ( GE) and the germination capacity ( GC) of seeds were determined. The seedling’s development was also evaluated based on ‘WinRhizo PRO 2009’ software. Then, in the second stage, pot tests were carried out, where the growth and development of species in the first year after sowing were temporarily measured. The parameters studied were the number, height, green and dry masses of the plants.
A Gompertz regression model describing seed species germination and number species as time dependent dynamic was applied. The data were analysed statistically using variance analysis (ANOVA) and the PCA (principal component analysis) method. The results of our study indicated that admixture of petroleum into the soil does not seriously affect the development dynamics of Lolium perenne seedlings. The diesel oil contamination mostly affects the germination of the Trifolium repens by a statistically significant increase of the maximum value of germination and increasing the maximum growth rate.