Now showing 1 - 7 of 7
  • Publication
    Mechanical and electrical properties of the solid sapropel
    (2015) ;
    Josef Timmerberg
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    ;
    Paul Beckmann
    ;
    Valentina Popa
    ;
    Regina Wagner
    In this paper are explored the mechanical (ultimate compression strength, ultimate strain, Young’s modulus, hardness) and the electrical (relative permittivity, specific electrical resistance, quality factor, their dependence on the electric field frequency in the range till 1MHz) properties of the solid sapropel. For the researches are used samples from the solid, monolith sapropel (obtained in the drying process) and samples from the sapropel powder that are pressed with a different force; before the measurements, a part of these samples were heated. There is explored the dependence of the relative permittivity on temperature. Are explored the methods for the forming of the products from the solid sapropel powder.
    Scopus© Citations 1
  • Publication
    EFFECT OF HEAT TREATMENT ON ELECTRICAL AND MECHANICAL PROPERTIES OF THE SOLID SAPROPEL
    (2017) ; ;
    Rene Castro
    ;
    Vladimir Solovyev
    ;
    Josef Timmerberg
    ;
    Alexander Cvetkov
    ;
    Sergey Gango
    ;
    Angelika Borkenstein
    ;
    Paul Beckmann
    ;
    Helmut Schütte
    ;
    Nikolai Puchkov
    ;
    Sergey Trifonov
    In this work changes of electrical and mechanical properties (hardness) of the solid sapropel after its heat treatment were researched. Changes of real and imaginary parts of dielectric permittivity, dielectric losses and specific electrical resistance depending on electrical field frequency in the range 0.01Hz- 1MHz were observed. Temperature dependences of AC (at 1 kHz) and DC electrical conductivity were studied. Chemical sample composition, IR spectra and structure of the solid sapropel were investigated. Heat treatment has a noticeable effect on the electrical characteristics of solid sapropel due to the strong influence of water on the charge transfer in this complex material. Charge transfer occurs predominantly due to ion migration and demonstrates strong dependence upon hydration - dehydration processes. After the heat treatment of the solid sapropel at the temperature of 1000C its hardness doesn’t change. If the sample of the solid sapropel is subjected to 20 min heat treatment at the temperature of 1500C, its hardness decreases by 5.4%, the number of C=C bonds decreases by 6.3±0.1%, the number of C=N bonds decreases by 2.2±0.1%, the number of C-C bonds decreases by 1,7±0.1%, the number of C-H bonds increases by 18.5±0.3%. It shows that in the temperature range 100-1500C destructive processes of the solid sapropel start, although visually (with optical microscope and with SEM) changes of structure are impossible to observe yet.
    Scopus© Citations 2
  • Publication
    Overview Of The River Basin Management Plans In The Baltic Region Under The Waterpraxis Project
    (2015)
    Māris Mednis
    ;
    Ivars Matisovs
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    ; ;
    Gundars Vaļģis
    The paper provides brief overview of the river basin district management plans in the Baltic region within the WATERPRAXIS project, linked to the EU Water Framework Directive. Latvian experience in completion of the river basin district management plans is emphasized comparing to other regional cooperation partners. Article is based on the report documents, analysis of the available data and review of the development projects subject to implementation. To some extent also potential issues for discussion are outlined. Certain Baltic countries have had difficulties complying with the EU Water Framework Directive,and there are some potential areas of contention, which should be taken into account in further activities. In course of the administrative and territorial reform and compliance with other EU directives (e.g. in the renewable energy sector) modifications can be made to the status of spatial and also river basin management plans and for the purpose of sustainable development in the region.
  • Publication
    A Method For Determination Of Specific Electrical Resistance Of Steel And Nano-Coating Sputtered On It
    (2015) ;
    Josef Timmerberg
    ;
    Konstantins Savkovs
    ;
    Aleksandrs Urbahs
    ;
    Paul Beckmann
    The paper describes methods developed to determine specific electrical conductivity and relative magnetic permeability of cylindrical steel items and nano-coatings deposited on them by sputtering. Research enables development of a new method for determination of thickness of vacuum deposited nano- coating that is based on application of skin effect.
  • Publication
    Does the energy transfer from Ar(1s) atoms to N2 lead to dissociation?
    (2020)
    Claus‐Peter Klages
    ;
    ;
    Lars Bröcker
    ;
    Detlef Loffhagen
    Dielectric‐barrier discharges (DBDs) in Ar–N2 mixtures, with N2 fractions in 0.1–1% range, would be attractive alternatives to DBDs in pure N2 if energy‐transfer reactions between Ar(1s) atoms and N2 molecules were an efficient source of N atoms. Attempts to functionalize polyolefins in flowing postdischarges fed by such DBDs, as well as the search for the First Positive System in the emission spectrum, however, failed. Evidently, the energy‐transfer reactions do not produce N atoms. For Ar(1s3) and Ar(1s5) metastable states, this fact has already been reported in the literature. For Ar(1s2) and Ar(1s4) resonant states, a quantitative argument is derived in this paper: energy transfer from Ar(1s) atoms to N2 molecules is not an efficient source of N atoms.
    Scopus© Citations 3
  • Publication
    RESERCH OF LASER MARKING CHANEL GEOMETRICAL DIMENSIONS DEPENDENCE OF CHANGE OF LASER RADIATION PARAMETERS ON STAINLESS STEEL
    (2016-04-20)
    Dunkins, Vitālijs
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    Komkovs, Jurijs
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    Narica, Pavels
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    Valiniks, Jānis
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    ; ;
    Publication describes results of the stainless steel laser marking, which shows relationship between geometry of the treated surface and parameters of the laser radiation, such as power, pulse frequency, and processing speed.
  • Publication
    Autonomous Vehicles and Mechatronics Education
    (2020)
    Gilberto Marzano
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    ;
    Svetlana Usca
    Automotive mechatronics involves the multidisciplinary integration of automotive mechanical and electronic systems. As such, automotive mechatronics education integrates knowledge and competences across automotive-specific mechanics, electronics, communication, advanced control, and modeling. Over the last few years, the subject of autonomous vehicles has been attracting significant attention from researchers, as well as interest from the media and the public at large. It encompasses a myriad of new applications, ranging from driverless cars to airborne surveillance of sensitive areas. Designing solutions for autonomous vehicles requires the integration of hardware and software components, as well as interaction with cloud-based servers. This paper focuses on autonomous/unmanned ground vehicles within the scope of a mechatronics curriculum. It has been proposes an educational model for autonomous vehicles for inclusion in the new mechatronics curriculum of NewMetro, an EU funded project that aims to develop an innovative European framework of competences for mechatronics education.