Prohlížení Acta Polytechnica. 2020, vol. 60 dle názvu

Zobrazují se záznamy 10-29 z 58

    • BETA CANTOR SERIES EXPANSION AND ADMISSIBLE SEQUENCES 

      Autor: Caalim , Jonathan; Demegillo , Shiela
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      We introduce a numeration system, called the beta Cantor series expansion, that generalizes the classical positive and negative beta expansions by allowing non-integer bases in the Q-Cantor series expansion. In particular, ...

    • CHAOTISED POLYMERIC HOLLOW FIBRE BUNDLE AS A CROSSFLOW HEAT EXCHANGER IN AIR-WATER APPLICATION 

      Autor: Kroulíková , Tereza; Astrouski , Ilya; Raudenský , Miroslav
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Fifteen years ago, polymeric hollow fibre heat exchangers were presented for the first time. Nowadays there are not only the shell-and-tube types as there were at the beginning. In this paper, six chaotised polymeric hollow ...

    • COMPLEXITY REDUCTION OF CYCLOSTATIONARY SENSING TECHNIQUE USING IMPROVED HYBRID SENSING METHOD 

      Autor: Abdullah , Hikmat N.; Dawood , Zinah O.; Abdelkareem , Ammar E.; Abed , Hadeel S.
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      In cognitive radio system, the spectrum sensing has a major challenge in needing a sensing method, which has a high detection capability with reduced complexity. In this paper, a low-cost hybrid spectrum sensing method ...

    • COUPLED ELECTROMAGNETIC-THERMAL SIMULATION OF A POWER TRANSFORMER BY 3D FEM 

      Autor: Henriques , Henrique Oliveira; Vizeu , Carlos Eduardo; Souza , Paulo Cesar; Costa , Mauricio Caldora; Sotelo , Guilherme Gonçalves; Sousa , Jonaylton Moura; Fortes , Marcio Zamboti; Ferreira , Vitor Hugo
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Power transformers are the most common equipment in an electric power system, which has been manufactured in the last decade. However, overheating can damage them, considerably reducing their operation lives, which may ...

    • DEFORMATION ANALYSIS OF LAYERED REINFORCED CONCRETE - FOAM CONCRETE FLOOR SLABS 

      Autor: Lytvyniak , Oksana
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      This article presents a theoretical study of a stress-strain state of layered reinforced concrete - foam concrete floor slabs (hereinafter called as the LRFCS), with the use of a deformation analysis. Compressive and tensile ...

    • DEVELOPMENT OF NUMERICAL MODELS FOR THE PREDICTION OF TEMPERATURE AND SURFACE ROUGHNESS DURING THE MACHINING OPERATION OF TITANIUM ALLOY (Ti6Al4V) 

      Autor: Daniyan , Ilesanmi; Tlhabadira , Isaac; Mpofu , Khumbulani; Adeodu , Adefemi
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Temperature and surface roughness are important factors, which determine the degree of machinability and the performance of both the cutting tool and the work piece material. In this study, numerical models obtained from ...

    • EIGENVALUES EVALUATION OF GENERALLY DAMPED ELASTIC DISC BRAKE MODEL LOADED WITH NON-CONSERVATIVE FRICTION FORCE 

      Autor: Úradníček , Juraj; Musil , Miloš; Bachratý , Michal
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      This paper deals with the evaluation of eigenvalues of a linear damped elastic two-degrees-of-freedom system under a non- onservative loading. As a physical interpretation of a proposed mathematical model, a simplified ...

    • ENERGY GAIN FROM ERROR-CORRECTING CODING IN CHANNELS WITH GROUPING ERRORS 

      Autor: Kuznetsov , Alexandr; Oleshko , Oleg; Kuznetsova , Kateryna
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Abstract. This article explores the a mathematical model of the a data transmission channel with errors grouping. We propose an estimating method for energy gain from coding and energy efficiency of binary codes in channels ...

    • EXPERIMENTAL INVESTIGATION OF THE POZZOLANIC POTENTIALS OF MILLET AND RICE HUSK ASH AS MINERAL ADDITIVE IN SELF-COMPACTING CONCRETE 

      Autor: Wasiu , John; Oluwatosin , Fashina Ayoola
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Self-compacting concrete (SCC) is a new concept of concrete mix which flows in a formwork and consolidates itself without the need for compaction. Effectively compacting concrete can be very difficult especially in areas ...

    • EXTERNAL ROLLING OF A POLYGON ON CLOSED CURVILINEAR PROFILE 

      Autor: Kresan , Tetiana; Pylypaka , Serhii; Ruzhylo , Zynovii; Rogovskii , Ivan; Trokhaniak , Oleksandra
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The rolling of a flat figure in the form of an equilateral polygon on a curvilinear profile is considered. The profile is periodic. It is formed by a series connection of an arc of a symmetrical curve. The ends of the arc ...

    • EXTRACTION AND EVALUATION OF OIL FROM GREEN ALGAE CLADOPHORA GLOMERATA BY HEXANE/ETHER MIXTURE 

      Autor: Yusuff , Adeyinka Sikiru; Ewere , Donatus
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The overall aim of this study was to grow green algae Cladophora glomerata, extract oil from it, and characterize the extracted oil to gain insight into its physicochemical properties. The effects of parameters affecting ...

    • HEAT TRANSFER ENHANCEMENT AND FRICTION IN DOUBLE PIPE HEAT EXCHANGER WITH VARIOUS NUMBER OF LONGITUDINAL GROOVES 

      Autor: Sunu , Putu Wijaya; Anakottapary , Daud Simon; Suarta , I Made; Santosa , I Dewa Made Cipta; Suarsana , Ketut
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      It has been found out that heat exchangers with longitudinal grooves produce better heat transfer than those without longitudinal grooves. However, up to now, there have been few investigations and applications of longitudinal ...

    • HOMOGENIZATION OF TRANSPORT PROCESSES AND HYDRATION PHENOMENA IN FRESH CONCRETE 

      Autor: Beneš , Michal; Štefan , Radek
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The problem of hydration and transport processes in fresh concrete is strongly coupled and non- inear, and therefore, very difficult for a numerical modelling. Physically accurate results can be obtained using fine-scale ...

    • INFLUENCE OF CHEMICAL POLYMER ADDITIVE ON THE PHYSICAL AND MECHANICAL PROPERTIES OF EXPANDED POLYSTYRENE CONCRETE 

      Autor: Wasiu , John; Baba , Daoud Mohammad
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      This research investigated the effect of Renolith chemical polymer additive (RCPA) on the properties of expanded polystyrene (ESP) concrete. Renolith chemical additive is a polymer-based product in a liquid form made up ...

    • INVESTIGATION OF THE DYNAMIC BEHAVIOUR OF NON-UNIFORM THICKNESS CIRCULAR PLATES RESTING ON WINKLER AND PASTERNAK FOUNDATIONS 

      Autor: Salawu , Saheed; Sobamowo , Gbeminiyi; Sadiq , Obanishola
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The study of the dynamic behaviour of non-uniform thickness circular plate resting on elastic foundations is very imperative in designing structural systems. This present research investigates the free vibration analysis ...

    • KINEMATIC SYNTHESIS OF CENTRAL-LEVER STEERING MECHANISM FOR FOUR WHEEL VEHICLES 

      Autor: Pramanik , Santiranjan; Thipse , Sukrut Shrikant
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      A central lever steering mechanism has been synthesized to obtain five precision points for a four-wheel vehicle using Hooke and Jeeves optimization method. This compound mechanism has been studied as two identical crossed ...

    • LASER ULTRASONIC MEASUREMENT OF MECHANICAL DECAY IN LIMESTONE CAUSED BY FREEZE-THAW CYCLES 

      Autor: Kravcov , Alexander; Franek , Ondřej; Morozov , Nikolaj; Kucewicz , Michał; Tomaszewski , Michał; Svoboda , Pavel; Baranowski , Paweł
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      In this article, an innovative new method of non-destructive testing for estimating the sensitivity of limestone is presented. An advantage of the laser ultrasonic structuroscopy method is the time and the quality, due to ...

    • MICROSTRUCTURAL CHARACTERISTICS, MECHANICAL AND WEAR BEHAVIOUR OF ALUMINIUM-ALLOYED DUCTILE IRONS SUBJECTED TO TWO AUSTEMPERING PROCESSES 

      Autor: Adebayo , Abdullahi Olawale; Oyetunji , Akinlabi; Alaneme , Kenneth Kenayo
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The effect of aluminium addition and austempering processes on the microstructures, mechanical and wear properties of rotary melting furnace processed ductile irons was investigated. Ductile irons containing 1−4 wt.% Al ...

    • MINIMIZATION OF TOXIC EMISSIONS DURING BURNING LOW-GRADE FUEL AT KAZAKHSTAN THERMAL POWER PLANT 

      Autor: Askarova , Aliya; Šafařík , Pavel; Nugymanova , Aizhan; Bolegenova , Saltanat; Maximov , Valeriy; Bolegenova , Symbat
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      This paper presents new results of computational experiments on the implementation of Overfire Air (OFA) technologies using an example of a combustion chamber of the BKZ-75 boiler of the Shakhtinskaya power plant (Shakhtinsk, ...

    • MODEL REFERENCE ADAPTIVE CONTROL-BASED GENETIC ALGORITHM DESIGN FOR HEADING SHIP MOTION 

      Autor: Al-Awad , Nasir Ahmad
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      In this paper, the heading control of a large ship is enhanced with a specific end goal, to check the unwanted impact of the waves on the actuator framework. The Nomoto model is investigated to describe the ship’s guiding ...