The most important feature of bells is their sound. Their clarity and beauty depend, first of all, on the bell’s geometry - particularly the shape of its profile and the mechanical properties of alloy. Bells are the castings that work by emitting sound in as-cast state. Therefore all features that are created during melting, pouring, solidification and cooling processes will influence the bell's sound. The mechanical properties of bronze depend on the quality of alloy and microstructure which is created during solidification and depend on its kinetics. Hence, if the solidification parameters influence the alloy’s properties, how could they influence the frequencies of bell`s tone? Taking into account alterable thickness of bell's wall and differences in microstructure, the alloy's properties in bell could be important. In the article authors present the investigations conducted to determine the influence of cooling kinetics on microstructure of bronze with 20 weight % tin contents.
The paper analysed the influence of current frequency on the thermal field of the insulated busbar. Its physical model consist of two hollow cylinders and a solid cylinder with different material properties. In turn, the mathematical model is a system of heat conduction equations with the appropriate set of the boundary, initial and continuity conditions. The problem was solved using the modified Green’s method. As a result, the following characteristics and parameters of the busbar were determined as a functions of frequency: heating curves, local time constants, steady-state current ratings, and stationary temperature profiles. The results were positively verified by finite element method.
The never before published paper is one of the last writings of Juliusz Żórawski (1898–1967), professor architect and theoretician of architecture. The notion of limited complexity introduced here relates to individual characteristics of the conceptual abilities of man. Tasks of architecture are based on prognoses, and this brings with it the risk of making errors. The author criticises J. Fourastié’s prognoses related to the Earth’s overpopulation in 3000 AD, which would force building new cities above the ground, contrary to human psychosomatic nature and habitude.
Drilling operations of the Cape Roberts Project took place between 1997 and 1999 offshore of Cape Roberts in the western Ross Sea, Antarctica. These were made possible due to a group effort by geoscientists from Australia, Germany, Italy, New Zealand, Great Britain, and the United States. The major goal of this undertaking was the recovery and analysis of sediment core, which was expected to provide a first East Antarctic record of the Early Cenozoic hothouse to icehouse climatic transition. This goal was not attained. Nevertheless, over the three seasons, a 1500 m long composite section was recovered, including a predominantly Early Oligocene to Early Miocene (34—17 Ma) glaciomarine succession. It was analyzed in terms of sediment physical properties, paleontology, tectonic structures and geophysics. This multidisciplinary investigation allowed detailed reconstruction of a significant portion of local environmental history, spanning a period of highly variable environmental conditions strongly affected by local glacier advance and retreat across the Victoria Land Basin margin.