Browsing Acta Polytechnica by Title

Now showing items 787-806 of 880

    • The effects of potassium permanganate on the geotechnical properties of soils 

      Author: Ola, Samuel Akinlabi; Usifoh, Osemudiamen Ayoposi; Nnochiri, Emeka Segun
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2023)
      In Nigeria, potassium permanganate (KMnO4) is used as a chemical oxidant in the removal of hydrocarbons from polluted soils and groundwater, but there is no information on the effects of KMnO4 on the geotechnical properties ...

    • The Electrification of Tramways in Ostrava in 1900–1901 

      Author: Závodná , Michaela
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2012)
      This paper focuses on the electrification of tramways in Ostrava in 1900-1901. As the administrative, economic and cultural centre of an evolving industrial agglomeration, Ostrava had specific transportation requirements. ...

    • The engineering performance of eco-friendly concretes containing diatomite fly ash and ground granulated blast furnace slag 

      Author: Aruntaş, Hüseyin Yilmaz; Yildiz, Erkan; Kaplan, Gökhan
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2022)
      Approximately 10 % of CO2 is emitted from an ordinary Portland cement production. In cement and concrete production, CO2 emissions can be greatly reduced by using Supplementary Cementitious Materials (SCMs). In addition, ...

    • THE FIRST CENTURY OF COSMIC RAYS, AN HISTORICAL OVERVIEW 

      Author: Jones, Lawrence W.
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)
      The 1912 balloon flights of Victor Hess and related activities in those years are reviewed. Subsequent research during the early 20th Century is noted, including the discovery of the positron, mesons, and air showers. The ...

    • THE FIRST STARS 

      Author: Whalen, Daniel J.
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)
      Pop III stars are the key to the character of primeval galaxies, the first heavy elements, the onset of cosmological reionization, and the seeds of supermassive black holes. Unfortunately, in spite of their increasing ...

    • THE FLOQUET METHOD FOR PT-SYMMETRIC PERIODIC POTENTIALS 

      Author: Jones F., H.
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2014)
      By the general theory of PT-symmetric quantum systems, their energy levels are either real or occur in complex-conjugate pairs, which implies that the secular equation must be real. However, for periodic potentials it is ...

    • The Formation of a Power Multi-Pulse Extreme Ultraviolet Radiation in the Pulse Plasma Diode of Low Pressure 

      Author: Borgun , Ievgeniia V.; Azarenkov , Mykola O.; Hassanein , Ahmed; Tseluyko , Oleksandr F.; Maslov , Vasyl I.; Ryabchikovk , Dmitro L.
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)
      In this paper results are presented on experimental studies of the temporal characteristics of spike extreme ultraviolet (EUV) radiation in the spectral range of 12.2 ÷ 15.8 nm from the anode region of high-current (I = ...

    • THE GERDA EXPERIMENT: STATUS AND FUTURE PLANS 

      Author: Zavarise, Paolo
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)
      The GERDA experiment is searching for the neutrinoless double beta decay of 76Ge. An observation of the neutrinoless double beta decay will not only prove lepton number violation by two units, but also that the neutrino ...

    • THE GOODNESS OF SIMULTANEOUS FITS IN ISIS 

      Author: Kühnel , Matthias; Falkner , Sebastian; Grossberger , Christoph; Ballhausen , Ralf; Dauser , Thomas; Schwarm , Fritz-Walter; Kreykenbohm , Ingo; Nowak A., Michael; Pottschmidt , Katja; Ferrigno , Carlo; Rothschild E., Richard; Martínez-Núñez , Silvia; Torrejón , José Miguel; Fürst , Felix; Klochkov , Dmitry; Staubert , Rüdiger; Kretschmar , Peter; Wilms , Jörn
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2016)
      In a previous work, we introduced a tool for analyzing multiple datasets simultaneously, which has been implemented into ISIS. This tool was used to fit many spectra of X-ray binaries. However, the large number of degrees ...

    • THE HISTORY OF THE S PROCESS AND ITS PRESENT STATE 

      Author: Shaviv, Giora
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)
      We review the history and the present status of the s-process and point to problems in need of clarification. In some cases it has to do with lack of experimental data and in other the theory is missing.

    • The Impact of Active Conductors on Czech and Hungarian Lightning Protection Legislation 

      Author: Mikeš , Jan; Efmertová , Marcela; Szedenik , Norbert; Kutáč , Jirí
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)
      This paper summarizes the developmental conditions for the emergence of protection against lightning. It reviews the legislation especially in the Czech Republic over the last 15 years, and its application for active ...

    • THE IMPACT OF SELECTED PROCESSES AND TECHNOLOGICAL PARAMETERS ON THE GEOMETRY OF THE WELD POOL WHEN WELDING IN SHIELS GAS ATMOSPHERE 

      Author: Bradáč , Josef; Moravec , Jaromír
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2017)
      This paper is focused on welding with a consumable electrode in a gas shield atmosphere and its main aim is to show the influence of selected processes and technological parameters on the geometry of the weld pool in terms ...

    • THE IMPACT OF SUZAKU MEASUREMENTS ON ASTROPARTICLE PHYSICS 

      Author: Ota, Naomi
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)
      Results from the Suzaku X-ray broad-band observations of clusters of galaxies are summarized. Aiming at understanding the physics of gas heating/particle acceleration and the cluster dynamical evolution, we search for ...

    • The impact of the air temperature on measuring the zenith angle during the year in the ground layer of the atmosphere for the needs of engineering surveying 

      Author: Suk, Tomáš; Štroner, Martin
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2021)
      This paper presents the results of over a year-long experiment dealing with a temperature measurement to calculate the theoretical effect of the atmosphere on the measured zenith angle in engineering surveying. The ...

    • THE INFLUENCE OF BASALT MINERALS AS CEMENT SUBSTITUTION MATERIALS IN MORTAR 

      Author: Amin , Muhammad; Birawidha , David Candra; Isnugroho , Kusno; Hendronursito , Yusup; Sumardi , Slamet; Ario , Septa; Syafriadi , Syafriadi; Al-Muttaqii , Muhammad
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2019)
      This study was conducted to determine the effect of the concentration of basalt as a cement substitution material in mortar. Basalt was analysed by XRD and XRF. From the XRD results, the diffractogram shows the dominant ...

    • THE INFLUENCE OF CUTTING CONDITIONS ON THE SELECTED PARAMETERS OF THE SURFACE INTEGRITY 

      Author: Čep , Robert; Malotová , Šárka; Lichovník , Jiří; Hatala , Michal; Legutko , Stanislaw
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2018)
      The article deals with an investigation of residual stress in machined surface under conditions of high-feed milling and determination of the influence of machining conditions on the size and types of stress resulting from ...

    • THE INFLUENCE OF FRICTION STIR WELDED PROCESS PARAMETERS OF AA2519-T62 ON JOINT QUALITY DEFINED BY NON-DESTRUCTIVE LASER AMPLIFIED ULTRASONIC METHOD AND BY MICROSTRUCTURE ANALYSIS 

      Author: Kravcov , Alexander; Kosturek , Robert; Śnieżek , Lucjan; Kluczyński , Janusz; Franek , Ondřej; Morozov , Nikolaj; Maciejewski , Pawel
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2020)
      The presented research contains a description of a non-destructive laser ultrasound internal structure analysis of aluminium joints made by friction stir welding. In the research, four selected technological parameter ...

    • The Influence of Nitrogen in Ar+N2 Mixture on Parameters of High-Temperature Device with Electric Arc 

      Author: Jakubova , Ivana; Senk , Josef; Laznickova , Ilona
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2013)
      The paper presents the results of numerous experiments carried out on a high temperature device consisting of an arc heater with intensively blasted electric arc and reaction chambers connected to its output. The influence ...

    • THE INFLUENCE OF SILVER NANOPARTICLES SYNTHESIS ON THEIR PROPERTIES 

      Author: Mražíková , Anna; Velgosová , Oksana; Kavuličová , Jana; Krum , Stanislav; Málek , Jaroslav
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2018)
      Application of green methods to replace physical and chemical methods for synthesis of silver nanoparticles (AgNPs) has become necessary not only from economic aspect but especially due to its significant impact on ecosystem. ...

    • THE INFLUENCE OF SIZE FRACTION ON THE COMPRESSIBILITY OF PINE SAWDUST AND THE EFFECTIVENESS CRITERION FOR DENSIFICATION 

      Author: Matúš , Miloš; Križan , Peter; Kováčová , Monika; Beniak , Juraj
      (České vysoké učení technické v PrazeCzech Technical University in Prague, 2014)
      Particulate matter from biomass, e.g. wood sawdust, is very diverse. The basic parameter describing the densification process of particulate matter is its compressibility, quantified by the coefficient of compressibility. ...