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Playing nature in the contemporary search in shaping structural surfaces
Get PDFThe contemporary image of shaping modern architectural designs increasingly entails a synergy of design solutions in terms of form and structure. As a result, shaping integrated structures in the form of structural surfaces takes on particular importance. Modern trends are increasingly looking for analogies to the natural world. Playing Nature are projects inspired with cylindrical shapes, referring to the forms found in nature or using a bionic structure
Parametric identification of system model for the charge output accelerometer
Get PDFThe paper discusses the parametric identification of a system model for the charge output accelerometer based on the simultaneous approximation of amplitude and phase characteristics. The mathematical relationships refer to three models: the mechanical, electrical and complete models, are discussed in detail. The numerical calculations include the parametric identification of the system model for the PCB357B73 accelerometer and determination of the uncertainties associated with the parameters of this model
Each game of lines, solids and forms is based on the same principles and it starts with a concept. The biomorphic vision of the world created by Vincent Callebaut
Get PDFArchitecture as a discipline tends to be understood differently in different environments. Le Corbusier “lines, solids and surfaces are elements through which architecture manifests itself. A thought through, flawless, wonderful game of solids in the light”. The architecture of the 21st century has become a compilation of developed exemplars, from the simple to the organic. The value comes from the idea, the concept of combining all the elements in such a way that the resultant game is both aesthetic and original. Such a game can be seen in the projects of Vincent Callebaut
Contemporary environs of watercourses in Szczyrk – the Silesian Beskids
Get PDFAs a town of abundant natural environment resources, Szczyrk provides a good example of the spatial transformations taking place in recent years. The changes also affect watercourses and areas indicated as eligible for the status of protected areas. Nevertheless, the changes now in progress not only fail to comply with the currently valid trends in architecture and urban planning, but also frequently copy erroneous solutions from the past. The existing situation calls for undertaking appropriate actions for the future, which will enable preservation of the natural environment in the possibly unchanged form so that it could coexist with humans and their activities
Rotary-linear induction motor based on the standard 3-phase squirrel cage induction motor – constructional and technological features
Get PDFInduction motors with some degrees of freedom (more than one) belong to unconventional drives which offer wider possibilities of motion than traditional drives. These motors constitute a small group of electric drives, however, new requirements for mechatronic devices are the cause of growing interest in their steady and regular development. As far as rotary-linear motors are concerned, they can be used in devices dedicated to mixing and drilling ensuring both rotary and linear movements. Because of the complex construction of such motors, their manufacturing process is expensive. In order to reduce these costs, the authors develop and propose the concept of the 3-phase rotary-linear machine built-up on the basis of a standard 3-phase squirrel-cage motor. This approach results in the significant reduction of manufacturing costs through the use of prefabricated parts (e.g. complete stator, stack of stator sheets, motor housing), as well as allowing the partial adoption of technologies used for standard induction motors
The relationship between wind pressure on the surface of rectangular prisms and atmospheric boundary layer parameters
Get PDFThis paper considers the dependence of pressure fields on surfaces of rectangular prisms obtained from wind tunnel experiments on boundary layer characteristics. Six different variants of boundary layer flows were simulated in the wind tunnel. The qualitative coefficients of correlation Rs between the wind pressure coefficient Cp or its standard deviation σp and parameters describing boundary layer flows (wind speed profile, turbulence intensity profile, power spectral density) were estimated in order to determine how wind parameters influence surface pressure. Five rectangular prisms were placed in the wind tunnel. The following ratios of prism dimensions were adopted: D/B/H = 1:2:20 (R5); 1:2:10 (R3); 1:2:5 (R1); 1:4:20 (R4); 1:4:10 (R2)
Analysis of the Influence of Turbulence on the Heat Transfer Between Spherical Particles and Planar Surfaces
Get PDFThe heat transfer between particles and walls plays an important role in several industrial processes. Since established models often deal with simplifications for the surrounding gaseous phase, this work aims to acquire a fundamental understanding of the occurring transport phenomena. In this work, a high-resolved finite-volume method is applied carrying out direct numerical simulation of fluid dynamics and heat transfer simultaneously. The influence of turbulence on the heat transfer is discussed in this paper
The idea of the city and planning theories
Get PDFThe main question put forward in this paper is whether it is possible to outline the main features expressing the idea of a metropolitan city in the late-modern Europe and to point out their relations with contemporary theories of urban planning. In order to identify and systematise “the common ideological indicators” of a contemporary European metropolis, the following criteria have been used: 1) universally recognised principles of urban development, 2) basic assessment criteria of the urban spatial structure and 3) the major modes of controlling urban development. The author has also attempted to systematise the major urban planning theories developed at the turn of the 20th and 21st century and the planning concepts corresponding to various models of spatial structure development that can be found in the new European metropolises. The observations have been illustrated with two examples of planning practice
Control strategy for maximizing conversion efficiency of a small hydropower plant
Get PDFAn analysis of the energy conversion system which consists of a propeller water turbine, a permanent magnet synchronous generator and a power electronic converter is presented. The considered control strategy implements an optimizing technique that guarantees maximal average efficiency independently of hydrological condition changes through the constant search for optimal operation parameters. The water flow parameter, essential for objective function estimation, is eliminated by the dedicated control technique. The control method is implemented and tested in the model created in the Matlab/Simulink software. All characteristics and parameters were identified on a real small hydropower plant and on the special laboratory model
Numerical analysis of three-span slab post-tensioned with unbonded tendonsat ultimate.
Get PDFThe design of multi-span structures post-tensioned with unbonded tendons may differ from the assigned one for reinforced structures or structures post-tensioned with bonded tendons. In some cases Ultimate Limit State can be reached by different loading patterns to which we got used to i.e. load cases which result in maximum values of bending moments in spans and at supports. This behaviour is related to the lack of bond between concrete and strands and the assumption that the force in tendons has a uniform value between anchorages