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Analysis of the use of transistors based on SiC technology in inverters in the context of electromagnetic compatibility
Get PDFCurrently, manufacturers of power-electronic components are trying to introduce the silicon carbide (SiC) technology in their products and MOSFET transistors made with this technology are available on the market. They are characterised by a significantly higher operating frequency, reaching even 100 kHz and low switching losses. The application of this type of devices causes high voltage gradients at the inverter output, which can lead to increased inverter electromagnetic disturbances. This article presents test results and a high-frequency analysis, allowing for a preliminary evaluation of the use of SiC transistors in inverters in the context of electromagnetic compatibility
A comparative study of along-wind and crosswind responses of steel chimneys according to Polish and Eurocode standards
Get PDFAn analysis of the response of steel chimneys to wind action is presented in this paper. The approaches presented in the Polish standards and in Eurocode 1 referring to steel chimneys and wind action are shown here. Comparisons of along-wind and crosswind action according to these procedures are made. Responses to the wind action, i.e. displacements of the top of each chimney, are compared. Real chimneys were analyzed. In almost every case, significant vibrations due to vortex excitation was observed. Structural data was obtained from the literature. All chimneys and wind actions were modelled in FEM system – Autodesk Mechanical Simulation 2013. Very significant differences of the crosswind response were observed when analyzing two approaches proposed by Eurocode. Lateral displacements were larger than longitudinal displacements in many analyzed cases
Metropolis. Genius loci historic metrololitan cores and pan-European corridor
Get PDFMetropolises can be analyzed from numerous points of view. Miller’s Law allows us to analyze them in the context of their behavior as complex organisms, as the fruit of the process of globalization. Their layout over the space of the world is subjected to Zipf’s Law. The subject of this article is a fragment of this spatial layout, a latitudinal transportation corridor ‒ the Polish section of the A-4 route from Germany to Ukraine. The Author searches for the genius loci of the metropolises that are situated along this corridor, for the elements that allow their inhabitants to identify themselves with a given metropolis
A village in the park scenery
Get PDFThis article presents a brief description of the state of research on the idea of the village in the landscape park. This concept has many features that justify its prevalence in the practical activities of spatial planning, because it can be a form of realization of the idea of sustainable development
Flax fibers as natural filler for rigid polyurethane- -polyisocyanurate foams based on bio-polyol from rapeseed oil
Get PDFThe influence of flax fibers on the physical and mechanical properties and the flammability of rigid polyurethane-polyisocyanurate foams obtained from rapeseed oil-based polyol was analyzed. The rigid polyurethane-polyisocyanurate foams with apparent density of 40−48 kg/m3 were prepared. It has been found that the introduction of flax fiber has a beneficial effect on selected properties of obtained foams
New dimension for straw construction
Get PDFThe rising interest in the ecological and energy-saving constructions include the whole life cycle of building – starting from materials and ending with remains that a building leaves in the environment. The holistic view of the ecological construction leads to increase in the interest in constructions made from straw. This article focuses on the technology using straw bales in modern buildings. To a great extent the straw bale method fulfils modern, ecological trends because of low production costs, low energy use during production and biodegradation, among others. The article describes physical parameters specific for straw bale and gives examples of current projects of modern buildings made with this technology
Seen from Siena
Get PDFThe article discusses a series of paintings, on a vision of a modern city, inspired by the author’s recent visit to Siena, Italy. It describes an importance of architectural visions and its complementary role in relation to an architectural practice. The article presents the author’s experiences with the process of painting. It highlights the role of a quick sketch in the process of selecting and analysing a subject. Finally, it showsthe unique importance of traditional painting techniques in a realization of the subject, impossible to be replaced by a digital visualization
Evaluation of the efficiency of construction workers on different days of the week in terms of fuzzy sets
Get PDFThis paper presents the methodology for comparing previously designated efficiencies of teams of workers using the fuzzy set theory. Efficiency was tested using timekeeping on different days of the week in the execution of specific construction tasks by the same team. The article also presents previously tested factors in this aspect and evaluates the impact of a particular day of the week on resource efficiency
Architecture dressed in rationalism
Get PDFRome, as the headquarter of fascist Italy, became the place where il Duce was fulfilling his dreams of restoring the Great Empire. The architecture that appeared in the times of the dictator, is as much progressive (it has roots in the early 20th century European Avant-garde art), as it is traditional – through its references to ideas of culture and nation. In the course of the article, I presented the conditions that gave rise to fascist architecture in Rome. Daring architectural designs, connected with widening the streets, construction of new districts, highlighting the ancient monuments, led to destruction of parts of the city (mass evictions, damaged Renaissance and Baroque monuments). Realization of those enterprises was possible only during authoritarian rule – Mussolini had no difficulty either in commissioning the construction of the new, or destruction of the old buildings. At the threshold of the approaching war, Italian architecture performed primarily an ideological function, and secondarily, it fulfilled the material and aesthetic needs of the nation
The idea of a historic city. Heritage and creation
Get PDFAuthor addresses the issue of sustainability of the market square formula in the historical cities as public space, which to this day remains an attractive urban form. Against this background, it outlined the theory has been the continuity of composition of the city based on the balance between creation and cultural heritage