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Rectification column: criteria of efficiency
Get PDFIn the paper analysis of the factors influencing the efficiency of the rectification process is provided. The authors show that existing dependences, equivalent to HETP, cannot be used for calculating rectification plate columns and columns with vortex nozzles, in which the coefficients of mass transfer are substantially dependent on the irrigation density and the gas/steam velocity. The dependence of the efficiency of the packet vortex nozzle as a function of the hydrodynamic regimes of the vapour and liquid phases is proposed
Lwów period of S. Ulam’s mathematical creativity
Get PDFWe provide an outline of Stanisław Ulam’s results obtained in the framework of the widely understood Lvov school of mathematics
IPMSM with SMCrotor – optimization and experimental results
Get PDFThe work presented in this paper relates to an Interior Permanent Magnet Synchronous Motor (IPMSM) experimental results and optimization procedure programed in Matlab and Maxwell environments. The stator of the machine is a conventional stator with distributed winding. The subject of the first optimization stage was the geometry of the IPM machine, concerning average torque value maximization and maximum cogging torque value minimization under physical and technological constraints. The optimized rotor core is made of from Magnetic Powder (SMC). It was tested in a generator regime
Analysis of aerodynamic interference between a high-rise building and its immediate city surroundings
Get PDFThis paper summarizes results of wind tunnel tests of a high-rise building placed in Warsaw city centre. Aerodynamic laboratory studies were accomplished in a boundary layer wind tunnel. The main objective of the research was to determine the distribution of the mean wind pressure coefficient over the building’s external surfaces as affected by the aerodynamic interference between the structure and its immediate city surroundings. Interference coefficients of wind pressure and global wind forces acting upon the surfaces of the building walls and roof were calculated. The aerodynamic studies showed a significant influence of objects located nearby on the wind load that the high-rise building structure surfaces are subjected to
The concept of living. A housing estate as the mirror of time
Get PDFThe contemporary shape of the housing estate does not promote development of social bonds. No other pro-social movement in the whole history of urban space has changed so much in the traditional cityscape as the modern avant-grade of the 19th and early 20th century. The situation in urban planning and design at that time was similar to other fields of science. The period brought a change in understanding beauty in art and architecture, and modernism strongly emphasised functionalism, rational and utilitarian values of the living environment of man
Blurring the borders between architecture and the visual arts
Get PDFTraditional fields of visual arts – sculpture and painting – have been connected with architecture in different ways. At the end of 20th century, artistic practices within these arts intensified efforts aiming to incorporate architecture in an unprecedented manner into the area of interest as a source of inspiration. The contemporary phenomena have not only expanded, but very often introduced new actions and experiences of space perception that escape classical classification of fine arts
Games of illusions
Get PDFVisual illusion and optical deception are essential and admissible means in the creation of architectural quality. The users and beholders of architecture expect to be enchanted by the friendly ruses of illusion. The true masters of architecture have always been masters in the game of visual lies and deception. Architectural illusions are used to show us an idealised reality
Experimental Study to Develop a Control System for Submersible Mixers in Biogas Plants
Get PDFFor developing a control system for these agitators, the analysis focused on the rheological characteristics of digestates, the open jet in non-Newtonian fluids and the flow conditions in a biogas reactor. In addition to a clearly visible shear-thinning effect, the viscoelastic proportion of these substrates was also determined. Depending on the stirrer speed and the rheology, the angle of spread varies and a reverse flow can occur directly at the stirrer. Therefore, not only can the position of the stirrer be used to optimise the flow field. The conical spreading of the liquid jet also enhance the mixing process. By using thrust measurements, their suitability as controlled process variables could be demonstrated
Numerical Modeling of the Pulse Wave Propagation in Human Thoracic Aorta
No full textIn this paper, a solution to the numerical simulation of blood flow in the human thoracic aorta is presented. In vivo measurements of pulsewave waveforms were performed and used as the initial condition for numerical calculations. Equations resulting from the analysis of the general mass and momentum balance for blood flow were used for the description of aortal haemodynamics. The system of differential equations has been solved with the method of characteristics, which is often used in hydrodynamic problems. Numerical simulations were employed for the cases of three people of differing ages. As a result, time-dependent profiles of blood pressure and velocity as well as deformation of the arterial wall were determined
The idea of the socialist city. The case of Nowa Huta
Get PDFNowa Huta represents a complex space, full of paradoxes and inner contradictions. It is difficult to evaluate. The aim of the article is the attempt to analize the built environment of Nowa Huta, to present selected ideas connected with the creation of the city and situating them in a broader, but still architectural context, the context of architectural creativity and urban development. The analysis is accompanied with a commentary on the cultural space understood as the sphere of values and meanings present in the material urban tissue