The present-day methods of supervising the operational use of jet engines are based, among other things, on computerised procedures of monitoring and recording various failure modes, including the surge. This dangerous mode of operation of a turbojet engine occurs quite commonly while operating it. In some cases, it could result even in the engine destruction. What has been presented in this study is the way of applying a non-linear observer of a one-spool single-flow turbojet to generate a computer algorithm to detect the surging. An exemplary application of such an algorithm to monitor the surging that occurs in the K-15 engine has also been shown.

New information about presence and features of some Lecanora species as well as their ecology and distribution in Antarctica are provided. Lecanora dispersa (Pers.) Sommerf. is confirmed to occur in the Antarctic region; L. sverdrupiana Řvst. is recorded for the first time from maritime Antarctica; L. torrida Vain. is reported as new for that Antarctic area and for the southern hemisphere. An attempt to summarize the present state of knowledge for the genus Lecanora in the Antarctic region is made. Several species, which require more in depth studies, are briefly discussed and an up-to-date list of species occurring in Antarctica is included.

Various methods for steady-state and transient analysis of temperature distribution and efficiency of continuous-plate fins are presented. For a constant heat transfer coefficient over the fin surface, the plate fin can be divided into imaginary rectangular or hexangular fins. At first approximate methods for determining the steady-state fin efficiency like the method of equivalent circular fin and the sector method are discussed. When the fin geometry is complex, thus transient temperature distribution and fin efficiency can be determined using numerical methods. A numerical method for transient analysis of fins with complex geometry is developed. Transient temperature distributions in continuous fins attached to oval tubes is computed using the finite volume - finite element methods. The developed method can be used in the transient analysis of compact heat exchangers to calculate correctly the heat flow rate transferred from the finned tubes to the fluid.

Bogusław Wolniewicz’s book Things and facts, although it is essentially devoted to the interpretation of the Wittgenstein’s Tractatus, also has a substantive layer in which Wolniewicz raises very important problems in the fields of methodology, semiotics and metaphysics, such as: (a) the problem of clarity of philosophical texts and its relation to simplicity and brevity, as well as to thoroughness and suggestiveness; (b) the problem of semantic correlation types; (c) the problem of analysis, interpretation and definition; (d) the problems of modality, negative facts, absolute monism and coherentionism; (e) the problem of abstraction and moral-praxeological antinomy. The author of the paper reconstructs Wolniewicz’s views on these matters.

The communicative turn in historiography has extended source criticism within historical studies by examining sources as products of human action. This article presents some source critical considerations regarding travel reports as documents of their time, and reviews their narrative perspective taking point of departure in theoretical approaches from literary studies. The overriding question here is how and to what extent the supposed and simultaneously strenuous objectivity of the historical sources is provided in three selected international travel reports written by travellers, observers and intellectuals, who visited Poland during World War I.

One of the more sensitive and touchy fields in which a confrontation occurs of significantly different visions of reality is being made by the understanding and representing of heaven. In those remarks I recall the standpoint of Catholic theologians and some of the selected scholars representing natural sciences. However, even such selective comparison shows how great the differences are between the visions of heaven sketched by the theologians and those by the natural scientists. Although they were and still are tray representatives of natural sciences, who had found and still find even if not linking points connecting those radically different views of heaven, than at least some sort of compromise in acknowledging their validity. On the other hand even them admit that it requires the use of significantly different standards of validity in theology and natural sciences.