Unsteady motion of the impeller is one of the several methods to improve mixing in unbaffled vessel. It is very important in pharmaceutical industry, crystallization processes or some chemical reaction with catalyst where baffles are not recommended. The literature data shows that unsteady mixing cause generation of axial flow for radial impellers (Rushton turbine). The purpose of this study was to investigate axial force for axial impellers like A315, HE-3 and SC-3. Moreover, the momentum number, flow number and pumping efficiency were analysed. Results shows that axial force for unsteady mixing is higher in comparison to steady-state mixing. Also, the comparison of axial force between impellers shows that blades influence momentum number and flow number. Impellers with larger blade surface generate stronger axial force. The obtained results reveal that unsteady mixing with axial impellers could be apply for solid-liquid mixing as suitable alternative to steady-state mixing.

Backlogs of transmission facilities (pipelines, power lines, media networks) on third – party property require regulation. This applies to both existing infrastructure and that which remains in the design phase. Drawing on literature, legislation, and practical knowledge, the article’s authors combined statutory definitions and court interpretations with industry guidelines. The transmission easement term was introduced to the Polish law the Civil Code (Act of 2008). The issue of transmission easement, and especially the rules for defining the scope of encumbrances, areas of influence the facilities have on the real estate, and the remuneration related to that, are complex issues that are worthy of being analysed more closely. The analysis of judical decisions and practical vocational experience have allowed for determining the scope of rights and obligations related to the easement laws. It is the intent of the authors of this article for its contents to clarify the transmission easement term and to draw attention to associated issues. We focus on showcasing the transmission easement issue law-wise, with aid of e.g. rulings of Polish common courts, by highlighting the defectiveness and incompleteness of regulations. It is meant as a basis for initiating detailed studies aimed at determining solutions to specific problems.

The study focuses on the geochronology and correlation between loesses and glacial tills in the Vistula catchment in Poland, in an area covered by all Scandinavian ice-sheets and characterized by thick loess successions. The basis for this correlation was a litostratigraphic analysis of selected loess sites in the uplands, which are well-documented in the literature, and the occurrences of loess and loess-like deposits under the cover of glacial deposits in the lowland part of the Vistula catchment, characterized by a much sparser documentation. The nomenclature of loess horizons follows Maruszczak (2001) and Kukla (1987), but sometimes is significantly changed, according to modern Quaternary stratigraphical schemes. According to the analysis, accumulation of almost all loess horizons distinguished so far has been documented in the Pleistocene succession of the Vistula catchment: the oldest – lower (LNd), middle (LNs), and upper (LNg); older: lower (LSd), middle (LSs), and upper (LSg); and younger: lowest (LMn), lower (LMd), middle (LMs), and upper (LMg). In most cases loess accumulation took place in steppe-tundra conditions preceding the maximum ice-sheet development during the succeeding Scandinavian glaciations. For selected sites, the loess occurrence is presented in superposition to glacial tills and interglacial deposits. The distinguished loesses and glacial tills are tied to the stratigraphic schemes of the Pleistocene in Poland (Marks et al. 2016, 2019) and correlated with Ukrainian loess horizons (Łanczont et al. 2019).