Prohlížení Acta Polytechnica. 2020, vol. 60 dle názvu

Zobrazují se záznamy 18-37 z 58

    • 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 ...

    • MODELING OF MATERIAL BALANCE FROM THE EXPERIMENTAL UCG 

      Autor: Durdán , Milan; Terpák , Ján; Kačur , Ján; Laciak , Marek; Flegner , Patrik
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The underground coal gasification is a continually evolving technology, which converts coal to calorific gas. There are many important parameters in this technology, which are difficult to measure. These parameters include ...

    • NATM TUNNELS – CONSIDERATION OF THE PARTLY DAMAGED PRIMARY LINING IMPACT FOR THE SECONDARY LINING EVALUATION 

      Autor: Trunda , Vlastislav; Hilar , Matouš
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Tunnels excavated by the New Austrian Tunnelling Method (NATM) are traditionally supported by a double-shell lining. The primary lining is generated from reinforced sprayed concrete with rockbolts, the secondary lining is ...

    • NEURINGER-ROSEINWEIG MODEL BASED LONGITUDINALLY ROUGH POROUS CIRCULAR STEPPED PLATES IN THE EXISTENCE OF COUPLE STRESS 

      Autor: Vashi , Yoginibahen Devendrasinh; Patel , Rakesh Manilal; Deheri , Gunamani Biswanath
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      This study intents to scrutinize the impact of ferrofluid in the presence of couple stress for longitudinally rough porous circular stepped plates. The influence of longitudinal surface roughness is developed using the ...

    • Newmark algorithm for dynamic analysis with Maxwell chain model 

      Autor: Schmidt , Jaroslav; Janda , Tomáš; Zemanová , Alena; Zeman , Jan; Šejnoha , Michal
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      This paper investigates a time-stepping procedure of the Newmark type for dynamic analyses of viscoelastic structures characterized by a generalized Maxwell model. We depart from a scheme developed for a three-parameter ...

    • ON CFD INVESTIGATION OF RADIAL CLEARANCE OF LABYRINTH SEALS OF A TURBINE ENGINE 

      Autor: Čížek , Michal; Pátek , Zdeněk
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      Fluid flow in labyrinth seals of a turbine engine is described. The aim is to describe numerical calculations of fluid flow in labyrinth seals and evaluate the calculated data for different settings of radial clearance of ...

    • ON THE SECOND LIGHT FLASH EMITTED FROM A SPARK-GENERATED BUBBLE OSCILLATING IN WATER 

      Autor: Vokurka , Karel
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The light emitted from the spark-generated bubbles oscillating in water is studied experimentally. Attention is paid to the emission of light from bubbles in the final stages of their first contraction and in the early ...

    • OPTIMIZATION OF A SMALL SOLAR CHIMNEY 

      Autor: Castro Silva , Janaina Oliveira; Maia , Cristiana Brasil
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      An optimization study to maximize the exergy efficiency of a small-scale solar chimney was carried out. Optimization variables include collector diameter (Dc), collector height (Hc), tower height (Ht), and tower diameter ...

    • OPTIMIZING EFFICIENCY OF THE COMBINED SEWER OVERFLOW CHAMBER HOBAS 

      Autor: Procházka, Jiří; Pollert, Jaroslav
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The paper deals with the design of swinging self-clean screen bars and the assessment of pressure losses in the combined sewer overflow chamber (HOBAS CSO Chamber), sold by the company HOBAS. The HOBAS CSO Chamber ensures ...