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Abstract

The presented paper encompasses four threads of deliberation that show the essence, cognitive value and utility of the concept of creative cities in the shaping of the future of contemporary cities. These threads are: creative development, a model of a creative city, preconditions of a creative city, and the use of a creative city as a vehicle of development.
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Abstract

The article aims at presenting the philosophy and model of the development vehicle to be understood as a new concept and tool to investigate and program local and regional development processes. The practical issues covered by the article include the identification and discovery of development vehicles, the elements of which can be observed in Polish metropolitan areas and agglomerations.
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Abstract

The article contains new approach to creating future of cities and urban regions based on the concept of creative cities. The core of this approach is to treat the genetic code of development as a tool for creating future of the territorial units. The combination and synergy of development genes that were considered as creativity, innovativeness and entrepreneurship allows the use of the fundamental elements of strategic analysis. On one hand, these elements are future challenges of cities and urban regions that they face in the perspective of global trends; on the other hand, they are strategic capabilities of sectors inseparably linked with creativity – sectors of culture, science and business, the integration of which is based on cultural heritage of cities and urban regions. The next issue of the article is the description of the way genes of urban development are manifested in the four sectors. It allows to present the genetic code of development function as a generator of strategic capabilities of creative sectors in cities and urban regions. Finally, the ideas of cross-sectoral undertakings for Polish big cities and urban agglomerations that enable facing intellectual and strategic global challenges were presented. This takes place through the use of strategic capabilities based on the genes of creativity, innovativeness and entrepreneurship; in this way, the genetic code of the development of large cities and urban agglomerations served as the new prospective approach to creating their future.
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Abstract

The results of studies presented in this article are an example of the research activity of the authors related to lead-free alloys. The studies covered binary SnZn90 and SnZn95 lead-free alloys, including their microstructure and complex mechanical characteristics. The microstructure was examined by both light microscopy (LM) and scanning electron microscopy (SEM). The identification of alloy chemical composition in micro-areas was performed by SEM/EDS method. As regards light microscopy, the assessment was of both qualitative and quantitative character. The determination of the geometrical parameters of microstructure was based on an original combinatorial method using phase quantum theory. Comprehensive characterization of mechanical behavior with a focus on fatigue life of alloys was performed by means of the original modified low cycle fatigue method (MLCF) adapted to the actually available test machine. The article discusses the fatigue life of binary SnZn90 and SnZn95 alloys in terms of their microstructure. Additionally, the benefits resulting from the use of the combinatorial method in microstructure examinations and MLCF test in the quick estimation of several mechanical parameters have been underlined.
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Abstract

The paper describes the studies of ternary SnZn9Al1.5 lead-free alloy from the viewpoint of its mechanical behavior as well as microstructure examined by the light and scanning electron microscopy. The authors focused their attention specifically on the fatigue parameters determined by the original modified low-cycle fatigue method (MLCF), which in a quick and economically justified way allows determination of a number of mechanical parameters based on the measurement data coming from one test sample only. The effect of the addition of 1.5% Al to the binary eutectic SnZn9 alloy on its microstructure and the obtained level of mechanical parameters was analyzed. The phases and intermetallic compounds occurring in the alloy were identified based on the chemical analysis carried out in micro-areas by the SEM/EDS technique. It was shown that the addition of 1.5% Al to the binary eutectic SnZn9 alloy resulted in a more favorable microstructure and consequently had a positive effect on the mechanical parameters of the alloy. Based on the conducted research, it was recommended to use a combinatorial method based on the phase quanta theory to quickly evaluate the microstructure and the original MLCF method to determine a number of mechanical parameters.
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Abstract

The study includes the results of research conducted on selected lead-free binary solder alloys designed for operation at high temperatures. The results of qualitative and quantitative metallographic examinations of SnZn alloys with various Zn content are presented. The quantitative microstructure analysis was carried out using a combinatorial method based on phase quanta theory, per which any microstructure can be treated as an array of elements disposed in the matrix material. Fatigue tests were also performed using the capabilities of a modified version of the LCF method hereinafter referred to in short as MLCF, which is particularly useful in the estimation of mechanical parameters when there are difficulties in obtaining many samples normally required for the LCF test. The fatigue life of alloys was analyzed in the context of their microstructure. It has been shown that the mechanical properties are improved with the Zn content increasing in the alloy. However, the best properties were obtained in the alloy with a chemical composition close to the eutectic system, when the Zn-rich precipitates showed the most preferred morphological characteristics. At higher content of Zn, a strong structural notch was formed in the alloy because of the formation in the microstructure of a large amount of the needle-like Zn-rich precipitates deteriorating the mechanical characteristics. Thus, the results obtained during previous own studies, which in the field of mechanical testing were based on static tensile test only, have been confirmed. It is interesting to note that during fatigue testing, both significant strengthening and weakening of the examined material can be expected. The results of fatigue tests performed on SnZn alloys have proved that in this case the material was softened.
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