The bridge structure’s development causes a riverbed cross-sections contraction. This influences the flow regime, being visible during catastrophic floods. Then the flow velocity increases and water piles up upstream the bridge, where headwater afflux could be observed. These changes depend on the watercourse geometry and the bridge cross-section properties, especially on the degree of flow contraction under the bridge. Hydraulic conditions under the bridge depend on flow velocity, dimensions, and shape of abutments, the granulometric composition of bedload, which can be quantitatively characterized by hydraulic resistance coefficients. The research subject of headwater afflux is equated with the recognition of morphodynamic processes occurring along the passage route. The headwater afflux could be estimated by empirical formulas and by the energy method using Bernoulli’s law. Empirical methods are optimized by adopting various statistical criteria. This paper compares the headwater afflux values calculated using two existing empirical formulas, Rehbock and Yarnell, and compares them with the results of laboratory tests. Following the assumption that the free water surface is influenced by flow resistance, an attempt was made to include friction velocity in the empirical formulas. Based on the Authors’ database, the coefficients used were optimized using bootstrap resampling in Monte Carlo simulation. The analyses demonstrated that the formula best describing the phenomenon of headwater afflux upstream the bridge is an empirical formula built based on the historical Yarnell formula, which includes friction velocity value. The optimized equation provides an average relative error of 12.9% in relation to laboratory observations.

This paper present the results of experimental investigations of condensation of R134a refrigerant in pipe minichannels with internal diameters 0.64, 0.90, 1.40, 1.44, 1.92 and 3.30 mm subject to periodic pressure instabilities. It was established that as in conventional channels, the displacement velocity of the pressure instabilities distinctly depends on the frequency of their hydrodynamic generation. The void fraction distinctly influences the velocity of the pressure instabilities. The form of this relationship depends on the internal diameter of the minichannels and on the method of calculating the void fraction.

In this paper a two-disc spinning disc reactor for intensified biodiesel synthesis is described and numerically simulated. The reactor consists of two flat discs, located coaxially and parallel to each other with a gap of 0.2 mm between the discs. The upper disc is located on a rotating shaft while the lower disc is stationary. The feed liquids, triglycerides (TG) and methanol are introduced coaxially along the centre line of rotating disc and stationary disc. Fluid hydrodynamics in the reactor for synthesis of biodiesel from TG and methanol in the presence of a sodium hydroxide catalyst are simulated, using convection-diffusion-reaction species transport model by the CFD software ANSYS©Fluent v. 13.0. The effect of the upper disc’s spinning speed is evaluated. The results show that the rotational speed increase causes an increase of TG conversion despite the fact that the residence time decreases. Compared to data obtained from adequate experiments, the model shows a satisfactory agreement.

The purpose of the article is to ask the question of the meaning of art in Emmanuel Levinas’ philosophy, taking into account not only the well-known text Reality and Its Shadow, but also texts from the later period of his work. The first part of the article is an interpretation of Reality and Its Shadow in the context of contemporary phenomenological concepts. The second, on the other hand, will be an attempt to show the change in Levinas’ approach to the visual arts based on his statements about Jean-Michel Atlan’s paintings and Sascha Sosno’s sculptures. The third, concluding section, will in turn attempt to describe works of contemporary art that would perhaps elude Levinas’ strict evaluation of art, highlighting the tension between the dimension of ontology and ethics, without falling into banal moralizing and allowing harm to be revealed without, however, leading the viewer to ethical paralysis.

This paper examines the coverage of women’s health issues, preventive care and prophylaxis in 19th-century Polish popular medical periodicals, in particular Dziennik Zdrowia dla Wszystkich Stanów [ Journal of Health for all Social Classes] (1801–1802), Przyjaciel Zdrowia [ Health’s Friend] (1861–1863), Zdrowie [ Health] (1877/78–1880), and Lekarz [ The Physician] (1903/04–1904/05). The authors of this study try to find an answer to the question whether those periodicals did succeed in giving women’s health issues the rank and status warranted by their significance.