This paper presents the results of fractionation of particulate and soluble organic matter in a mixture of maize silage and cattle manure (49:51% volatile solids) that was used as a feedstock for anaerobic digestion. The extended Weender’s analysis was adapted to measure raw protein, raw lipids, fraction of carbohydrates (including starch, cellulose, hemicelluloses) and lignin. The content of individual fractions in composite, Xc (as kg COD kg-1 COD) was: 0.111 proteins, 0.048 lipids, 0.500 carbohydrates and 0.341 inerts. The biodegradability of Xc was 68%. Based on material balance, the carbon concentration in Xc was 0.0326 kmol C kg-1 COD, whereas nitrogen concentration 0.0018 kmol N kg-1 COD. The estimated pH of the feedstock based on acid-base equilibrium corresponded to the actual value (pH 7.14).

The aim of this study was to implement ADM1xp model to simulate behavior of anaerobic co-digestion of maize silage and cattle manure. The accuracy of ADM1xp has been assessed against experimental data of anaerobic digestion, performed at OLR = 2.1 gVS dm-3·d-1 and HRT = 45d. Due to the high number of parameters in ADM1xp, it was necessary to develop a customized procedure limiting the range of parameters to be estimated. The best fitting of experimental to simulated data was obtained after verification of 9 among 105 stoichiometric and kinetic parameters. The values of objective function (Jc) ranged between 0.003 (for valerate) and 211 (for biogas production).

The effect of laser, as a heat source, on a one-dimensional finite body was studied in this paper. The Cattaneo-Vernotte non-Fourier heat conduction model was used for thermal analysis. The thermal conductivity was assumed temperature-dependent which resulted in a non-linear equation. The obtained equations were solved using the approximate-analytical Adomian Decomposition Method (ADM). It was concluded that the non-linear analysis is important in non-Fourier heat conduction problems. Significant differences were observed between the Fourier and non-Fourier solutions which stresses the importance of non-Fourier solutions in the similar problems.

This article discusses the use of small lead seals (seal tags) in early medieval Poland for commercial and customs control in the context of an economic crisis. The introduction of sealing goods by the Piasts is explained by its cultural transfer from Rus’. Polish commercial lead seals were in use synchronously with Hohlpfennigs from the middle of the 13th to the middle of the 14th century. Their design systematically reflected signs and symbols on bracteates and differed significantly from other small seals of Drohiczyn type from Rus’. The extraordinary number of small lead seals found at Drohiczyn possibly reflects a short- -term relocation of trade routes caused by military conflicts.