The article presents results of research on the influence of variable parameters of horizontal continuous casting on the structure of AlCu4MgSi (EN AW-2017A) alloy ingots. The special character of the process allows for a continuous change of some of its parameters, namely, of the casting speed and of the rate of the cooling fluid flow thorough the crystallizer. These parameters have a significant impact on the crystallization process of the liquid metal. Depending on the cooling rate, intensity of the convection inside the solidifying alloy, and its chemical composition, there may arise some differences in the structure of the cast. In this study, ingots obtained at different casting speeds have been analyzed. The research methodology, based on light microscopy and electron microscopy (SEM), as well as energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD), allowed for a thorough examination of the structure of the studied materials. The results were shown that an increase in the ingot casting speed leads to an increase in the average grain surface area.
Monitoring the solidification process is of great importance for understanding the quality of the melt, for controlling it, and for predicting the true properties of the alloy. Solidification is accompanied by the development of heat, the magnitude of which depends on the different phases occurring during solidification. Thermal analysis is now an important part of and tool for quality control, especially when using secondary aluminium alloys in the automotive industry. The effect of remelting on the change of crystallization of individual structural components of experimental AlSi9Cu3 alloy was determined by evaluation of cooling curves and their first derivatives. Structural analysis was evaluated using a scanning electron microscope. The effect of remelting was manifested especially in nucleation of phases rich in iron and copper. An increasing number of remelts had a negative effect after the fourth remelting, when harmful iron phases appeared in the structure in much larger dimensions.
The article is focused on the most recent investigations of glaciotectonic structures in high escarpment exposures of the Vistula valley from Dobrzyń to Kuzki in the western part of the Płock Basin. Deformations involve Neogene and occasionally the Lower Pleistocene deposits and they are not expressed as landforms. Structural investigations and analysis of archival geological data provided new information on the origin of large-scale shear structures. Results obtained are clearly contrary to the concept of Brykczyński (1982) regarding valley-side glaciotectonics in the Płock Basin. An emergence of the extensive zone of serial thrust structures of significant amplitude (up to 100–150 m) was found to have not been controlled by a palaeovalley. A driving mechanism is interpreted as a gravity spreading in front of ice sheets advancing from north-northeast during the South Polish Complex (Dorst-Elsterian).
The aim of the study was to develop a practical approach to parametric shaping of spatial steel rod structures formed based on a hyperbolic paraboloid. This design approach was realized by application of designing tools working in environment of Rhinoceros 3D, that is its plug-in Grasshopper for geometric modelling and Karamba 3D for structural analysis. The goal of this research was to elaborate an universal scripts in order to create rod structures‘ models of various forms and grid patterns, as well as evaluating their structural behaviour dependently on various boundary conditions. The optimisation criterion was the minimum mass and deflection. Several proposals of coverings by means of single layer grid structures were presented and analysed to choose the best solution. The rod structures generated based on a hyperbolic paraboloid turned out to be structures with good static properties, so may be an interesting proposals to cover large areas.
This article combines a general introduction to the crime fi ction of Walery Przyborowski with a study of the structure of the plot of his novels. The analyses of ten of his novels conclude with a typology of their narrative schemes, shown in the context of certain invariant patterns and the conventions of related literary genres. While the main objective of this study is to outline the structure of crime story and the social issues depicted in Przyborowski’s crime fi ction, it also pays some attention to the ways in which it refl ects his concerns about contemporary life and the condition of Poland under foreign rule. Basically, Przyborowski’s formula is to make use of the staples of the genre – mystery, adventure, romance – and the techniques of the popular novel. Moreover, his novels, like all of the 19th-century crime fi ctions, are clearly indebted to the conventions of the historical novel.
The Carpathian Orava Basin is a tectonic structure filled with Neogene and Quaternary deposits superimposed on the collision zone between the ALCAPA and European plates. Tectonic features of the south-eastern margin of the Orava Basin and the adjoining part of the fore-arc Central Carpathian Palaeogene Basin were studied. Field observations of mesoscopic structures, analyses of digital elevation models and geological maps, supplemented with electrical resistivity tomography surveys were performed. Particular attention was paid to joint network analysis. The NE-SW-trending Krowiarki and Hruštinka-Biela Orava sinistral fault zones were recognized as key tectonic features that influenced the Orava Basin development. They constitute the north-eastern part of a larger Mur-Mürz-Žilina fault system that separates the Western Carpathians from the Eastern Alps. The interaction of these sinistral fault zones with the older tectonic structures of the collision zone caused the initiation and further development of the Orava Basin as a strike-slip-related basin. The Krowiarki Fault Zone subdivides areas with a different deformation pattern within the sediments of the Central Carpathian Palaeogene Basin and was active at least from the time of cessation of its sedimentation in the early Miocene. Comparison of structural data with the recent tectonic stress field, earthquake focal mechanisms and GPS measurements allows us to conclude that the Krowiarki Fault Zone shows a stable general pattern of tectonic activity for more than the last 20 myr and is presently still active.