The helical jet is generated in a tangential pipe nozzle having the tangential and the axial inlets and the axial outlet. The flow directions in free jet spreading in the stationary air was measured by means of a flag type probe. The flow was visualized using the planar scattering technique. It was found that due to asymmetrical distribution of the tangential velocity in the jet leaving the nozzle, the air particles spread in the ambient with various intensity depending on the azimuthal angle. The result is that the jet has a spiral shape with bean-like cross-section.

The mathematical modeling of mineral processing is a very complex task because of random character of comminuted materials. However, it allows applying of standard laws of mass preservation and mass transport. The basic method of description of comminution processes is determination of particles size distribution curves for products. In the paper, the concept of applying so-called censored distribution functions was presented, what means equations of exponential, Weibull, log-normand logistic distribution functions as the basis of crushers work description (formulas 1, 2, 3 and 4). The censoring of distribution functions is being realized through acceptation of maximum particle size dmax and the shape of them depends on shape and scale parameters. The joining of technical parameters of comminuting devices with parameters of equations describing distribution functions of products allows creating of satisfying models of comminution processes. After application of general forms of separation curves the description of sieving processes is possible (equations 6a and 6b) and then also of comminution systems. The optimization of aggregates production may be based on introduction of goal function determining profit dependably on amount of individual assortments. In case of analysis of comminution systems (formulae 10) in preparation of feed to beneficiation the goal function should be based on levels of useful minerals exposure in individual fractions. The paper shows the possibility of simulation of comminution processes course leading to determination of optimal conditions of systems containing comminution and sieving processes. Furthermore, the necessity of creation of empirical models for grinding processes was shown as they would be the compensation of models being result of heuristic analysis of phenomena. Also, the elementary rules of selection of models forms and their modifications based on justification of relations between distribution function parameters and basic technical parameters of devices as well characteristics of comminuted materials were discussed. The paper is the introduction to further research of general approach to joining grained materials characteristics with comminution effects.

In the experiment, bubbles were generated from two brass nozzles with inner diameters of 1.1 mm. They were submerged in the glass tank filled with distilled water. There have been measured the air pressure fluctuations and the signal from the laser-phototransistor sensor. For analysis of the pressure signal the correlation (the normalized cross - correlation exponent) and non-linear analyses have been used. It has been shown that hydrodynamic interactions between bubbles can lead to bubble departure synchronization. In this case the bubble departures become periodic. The results of calculation of correlation dimension and the largest Lyapunov exponent confirm that hydrodynamic bubble interactions observed for 4 mm spacing between nozzels cause the periodic bubble departures from two neighbouring nozzles.

Energy efficiency improvement and ecological safety of heat power plants are urgent problems, which require scientifically grounded approaches and solutions. These problems can be solved partly within the presented heat-and-power cycles by including contact energy exchange equipment in the circuits of existing installations. A significant positive effectis obtained in the contact energy exchange installations, such as gas-steam installation ‘Aquarius’ and the contact hydrogen heat generator that also can use hydrogen as a fuel. In these plants, the efficiency increases approximately by 10–12% in comparison with traditional installations, and the concentration of toxic substances, such as nitrogen oxides and carbon monoxide in flue gas can be reduced to 30 mg/m3and to 5 mg/m3, respectively. Moreover, the plants additionally ‘generate’ the clean water, which can be used for technical purposes.

W tekście wskazuję na etyczny kontekst twórczości Ryszarda Wagnera. W skrócie sygnalizuję kwestię relacji wartości estetycznych i etycznych. Zaznaczam społeczne zaangażowanie pism teoretycznych Wagnera, skupiając się na emancypacyjnym charakterze egalitarnych i rewolucyjnych tez. W kolejnym wątku opisuję wpływ myśli Schopenhauera na autora Sztuki i rewolucji. Szczególnie skupiam się na wątku miłości, wyrzeczenia, poświęcenia i zanegowania woli. W ostatniej części odnoszę się do wagnerowskiego antysemityzmu i tzw. pism regeneracyjnych.

This article is a discussion of Ewa Domańska's and Hayden White's views on the usefulness of history against the background of similiar views of contemporary modernist and postmodernist theoreticians of history. This analysis is based on two books: Ewa Domańska's Mikrohistorie. Spotkania w międzyswiatach, and Hayden White's Poetyka pisarstwa historycznego, a collection of Hyden White's studies edited by Domańska.

One of the most prominent English historians, Thomas Babington Macaulay belongs to a group of thinkers which developed what H. Butterfield in 1931 called the ,,Whig interpretation of History". Although Butterfield criticised this kind of writing about the past, Macaulay's ,,History of England" became the most influential interpretation of English history in the 19th century. One of the most important issues for Thomas Babington was the process of the formation of the English political system. The English constitution, a fundamental element of political system of the largest empire in the! 9th century, was a very important model for every political thinker. This is why a presentation of Lord Macaulays view on the most important events which influenced the formation of the British political system is a key to understanding not only the English constitution but also the role and importance of historians and their works for English politics. The article presents one of the most influential interpretation of the English constitution in the 19th Century, written by the eminent historian and statesman Thomas Babington Lord Macaulay.