Defined as “the ways the writers project themselves into their texts to communicate their integrity, credibility, involvement, and a relationship to their subject matter and their readers” (Hyland, 1999: 101), stance can be expressed by a variety of means, including, among others, hedges, emphatics and attitude markers. The use of these elements – their frequency, distribution and variety in different text types – is language and culture-specific. This paper focuses on selected exponents of stance by which speakers of English and Polish express their assessment of the truth of a proposition and their commitment to this assessment, and more specifically, on high-value modal verbs of epistemic necessity and inference used in linguistics research articles in these two languages. The analysis is based on two corpora of research articles published in the years 2001–2006 in English- and Polish-language linguistics-related journals, each corpus consisting of 200 complete articles. The analysis focuses on the following modal and quasi-modal verbs: MUST, NEED, HAVE (GOT) TO (Eng.) and MUSIEĆ (Pl.) in an attempt to discuss their use in one specific genre and discipline but across languages and cultures. The results indicate that, compared to the English necessity and inference cluster, Polish MUST is heavily underrepresented, but that the proportion of epistemic and root meanings as well as the ratio of epistemic proper and indirect evidential senses is similar across the two studied corpora. It is also apparent that for the English data the relative frequency of individual modal expressions is different from that reported from non-academic varieties of English, and that the proportion of epistemic and root meanings for these modals is different in the studied sample and in non-academic contexts.

The paper presents the results of simulation tests of hydraulic resistance and temperature distribution of the prototype Stirling alpha engine supplied with waste heat. The following elements were analyzed: heater, regenerator and cooler. The engine uses compressed air as a working gas. Analyses were carried out for three working pressure values and different engine speeds. The work was carried out in order to optimize the configuration of the engine due to the minimization of hydraulic resistance, while maintaining the required thermal capacity of the device. Preliminary tests carried out on the real object allowed to determine boundary and initial conditions for simulation purposes. The simulation assumes that there is no heat exchange between the regenerator and the environment. The solid model used in simulation tests includes the following elements: supply channel, heater, regenerator, cooler, discharge channel. Due to the symmetrical structure of the analyzed elements, simulation tests were carried out using 1/6 of the volume of the system.

This paper describes the weather conditions on the NE coast of Sørkappland (South Spitsbergen) during August 2005, and considers them in the context of the general synoptic situation over the North Atlantic . A comparison of local climates features for the East and West coast of southern Spitsbergen shows that the general atmospheric circulation and direct solar radiation in summer are the decisive factors affecting weather on the East coast. Foehn effects were observed during the study period. In the East, these were triggered by the westerly cyclonic situation and, in the West, by the easterly. The differences in the intensity of foehn effects may be explained by a specific relief of the Sørkappland peninsula.

The paper looks at the issues of operation safety of the national power grid and the characteristics

of the national power grid in the areas of transmission and distribution. The issues of

operation safety of the national transmission and distribution grid were discussed as well as threats

to operation safety and security of the electricity supply related to these grids. Failures in the

transmission and distribution grid in 2017, caused by extreme weather conditions such as: a violent

storm at the night of 11/12.08.2017, hurricane Ksawery on 5–8.10.2017, and hurricane Grzegorz on

29–30.10.2017, the effects of which affected tens of thousands of electricity consumers and led to

significant interruptions in the supply of electricity were presented. At present, the national power

(transmission and distribution) grid does not pose a threat to the operation safety and security of

the electricity supply, and is adapted to the current typical conditions of electricity demand and the

performance of tasks during a normal state of affairs, but locally may pose threats, especially in

extreme weather conditions. A potentially high threat to the operation safety of the national power

grid is closely linked to: age, technical condition and the degree of depletion of the transmission and

distribution grids, and their high failure rate due to weather anomalies. Therefore, it is necessary

to develop and modernize the 400 and 220 kV transmission grids, cross-border interconnections,

and the 110 kV distribution grid (especially in the area of large urban agglomerations), and the MV

distribution grid (especially in rural areas). The challenges faced by the transmission and distribution

grid operators within the scope of investment and operating activities, with a view to avoiding

or at least reducing the scale of grid failures in the case of future sudden high-intensity atmospheric

phenomena, are presented.

Nadrzędnym celem funkcjonowania Krajowego Systemu Elektroenergetycznego (KSE) jest zapewnienie bezpieczeństwa dostaw energii elektrycznej. W okresie letnim nasila się tendencja wzrostowa zapotrzebowania na energię elektryczną wywołana m.in. przez upowszechnienie klimatyzacji. W związku z tym należy spodziewać się utrzymania tendencji wzrostowej zapotrzebowania szczytowego w okresie letnim. Przykłady z lat 2015, 2016 czy 2018 wskazują, że KSE potrzebuje letniego źródła szczytowego, które będzie w stanie wytwarzać energię elektryczną niezależnie od sytuacji hydrologicznej. Fotowoltaika jest źródłem energii, które może pokryć zapotrzebowanie szczytowe w dni upalne. W niniejszym artykule pokrótce scharakteryzowano problem wzrostu zapotrzebowania na energię elektryczną w okresie letnim i posłużono się przykładami zdarzeń, które miały miejsce w ostatnich latach. Głównym wnioskiem jest postulat rozbudowy mocy fotowoltaicznych, którego celem będzie produkcja energii elektrycznej w dni upalne pokrywająca szczytowe obciążenie sytemu. Przedstawiono zalety i wady takiego rozwiązania. Niekorzystne warunki atmosferyczne ograniczają produkcję energii elektrycznej z farm wiatrowych czy bloków konwencjonalnych, a także zwiększają straty w przesyle, dlatego fotowoltaika jest pożądanym źródłem z punktu widzenia KSE. W artykule powołano się na przykłady z Czech i Niemiec, gdzie znaczna moc zainstalowana fotowoltaiki pozwala na stabilizowanie pracy systemu elektroenergetycznego w dni upalne. Wskazano także na wzrost roli fotowoltaiki w KSE, który jest zgodny z założeniami Projektu Polityki Energetycznej Polski do 2040 roku.

This article describes a thermodynamic analysis of an oxy type power plant. The analyzed power plant consists of: 1) steam turbine for supercritical steam parameters of 600 °C/29 MPa with a capacity of 600 MW; 2) circulating fluidized bed boiler, in which brown coal with high moisture content (42.5%) is burned in the atmosphere enriched in oxygen; 3) air separation unit (ASU); 4) CO2 capture installation, where flue gases obtained in the combustion process are compressed to the pressure of 150 MPa. The circulated fluidized bed (CFB) boiler is integrated with a fuel dryer and a cryogenic air separation unit. Waste nitrogen from ASU is heated in the boiler, and then is used as a coal drying medium. In this study, the thermal efficiency of the boiler, steam cycle thermal efficiency and power demand were determined. These quantities made possible to determine the net efficiency of the test power plant.

The paper deals with the computational fluid dynamics modelling of carbon dioxide capture from flue gases in the post combustioncapture method, one of the available carbon capture and storage technologies. 30% aqueous monoethanolamine solution was used as a solvent in absorption process. The complex flow system including multiphase countercurrent streams with chemical reaction and heat transfer was considered to resolve the CO2 absorption. The simulation results have shown the realistic behaviour and good consistency with experimental data. The model was employed to analyse the influence of liquid to gas ratio on CO2 capture efficiency.

Adam Mickiewicz’s Pan Tadeusz (in English: Sir Thaddeus, or the Last Lithuanian Foray), the national epic poem, was first published in June 1834. It was perceived as a idyllic work, full of happiness and very ideal heroes. However, one of the most problem of this poem is treason! It is very important to put a question: what is treason in the strict sense of the word? There are a lot of kinds of treason or only one? Is it possible to betray own country on account of favouriting strange fashion, customs or painting? In Pan Tadeusz Mickiewicz intended to stand up for the Polish tradition. He had a high opinion of loyalty, steadiness and the selfless sense of duty.