Browsing by Author "Nosek, Jaroslav"

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    Advantages and Problems of Developing Unmanned One-Wheel Balancing Robots
    (Institute of Electrical and Electronics Engineers Inc., 2019-01-01) Zhmud, Vadim; Ivoilov, Andrei; Dimitrov, Lubomir; Roth, Hubert; Nosek, Jaroslav; Hardt, Wolfram; Trubin, Vitaly G.
    Currently, there is an intensive development of various variants of balancing robots, one-wheeled and two-wheeled ones. Two classes of two-wheeled robots can be distinguished: a) as on a Segway; b) as on a bicycle and a motorcycle. Both of these options are structurally unstable systems. Such structures without the use of an effective system of maintaining balance are fundamentally unstable, in the de-energized state they overturn. The equilibrium can be provided by a system with negative feedback. The development of a one-wheeled balancing robot in the version with an existing pilot has already been decided in practice, but driving such a vehicle requires a pilot with certain skills to ride it. In the unmanned version, all actions performed by the pilot must be replaced by an electromechanical system, which, firstly, provides an imbalance in order to set the direction and speed of movement through the system, which maintains this balance due to the rotation of the wheel, secondly, ensures the maintenance of equilibrium in the direction of the axis of this single wheel; thirdly, it forms the necessary effects for turning. Electromechanical propulsion can be a flywheel, a pendulum; one can also use a fan. At high speeds, it is also possible to use aerodynamic forces, for example, wings, but such a solution at the present stage of the development of technology should rather be considered exotic. However, a robot that is almost an aircraft due to lift from fans, wings or an air cushion may be the ideal solution for high-speed movements on a relatively flat surface. In this case, a purely symbolic touch of the ground, perhaps even interrupted when overcoming too deep and (or) short recesses, allows the robot to be classified as a ground-based (or jumping) device, which frees it from the formalities necessary for the legal use of flying unmanned aerial vehicles, formally such device is not flying mean. Accordingly, the movement of such a robot should be tied to the landmarks and possibilities of the route, its functions are also associated with ground objects, and the possibility of a short-term flight is only an additional bonus. These considerations make it relevant to consider such a way to resolve the issue of stabilizing the equilibrium of a one-wheeled robot, such as the use of lifting force of fans. However, the presence of the wheel creates other possibilities for the load-carrying capacity of the device, and so on; short-term hover by inertia requires completely different energy costs than continuous flight. The purpose of this study is to develop a set of technical proposals for the implementation of high-speed unmanned robot for informational purposes: information gathering (video, audio, electrometer, etc.), as well as for the removal and delivery of small loads. The objectives of the study are to analyze the existing technical solutions and a motivated proposal for the basic principles of the design of the specified balancing robot. A key feature of such robots should be steady motion in an unmanned version along a predetermined trajectory over rough terrain, including the slope of the terrain both in the direction of motion and in the direction orthogonal to the direction of motion.
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    Botanická zahrada v Liberci
    (Technická univerzita v Liberci, 2018-02-01) Nosek, Jaroslav; Univerzitní knihovna TUL
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    Cestovní zpráva Teambuilding 2019
    (2019-08-06) Nosek, Jaroslav; Univerzitní knihovna
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    Combination of nZVI and DC for the in-situ remediation of chlorinated ethenes: An environmental and economic case study
    (PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND, 2020-04-01) Černíková, Martina; Nosek, Jaroslav; Černík, Miroslav
    Over the past two decades, the use of nanoscale zero-valent iron (nZVI) has emerged as a standard method of contaminated groundwater remediation. The effectiveness of this method depends on key intrinsic hydrogeological parameters, which can affect both reactivity of the nanoparticles and their migration in the aquifer. In the case of low hydraulic permeability, the migration of nanoparticles is limited, which negatively influences remediation. An application of nZVI reinforced with a DC electric field led to a significant increase in the efficiency of remediation, as demonstrated by long-term monitoring at a former industrial site in Horice (Czech Republic). For the method testing, a 12 x 9 m polygon was defined around well 154, where the original contamination was predominantly composed of DCE (7300 mu g/l), and with a total concentration of chlorinated ethenes of 8880 mu g/l. During the first stage of the activities, 49 kg of nZVI was injected and monitored for two years. Subsequently, the electrodes were installed, and for three years, the synergistic action of nZVI within an applied DC field was monitored. Based on 32 monitoring campaigns performed over the six years, the combined method was compared with an application of the only nZVI in technical, environmental and economic terms. Technically, the method requires annual reinstallation of anodes as a result of their oxidative disintegration. Environmentally, the method provides significantly improved chlorinated ethane reduction, remediation of low permeable zones, and extended efficiency. Economically, the method is five times cheaper when compared to the nZVI used alone.
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    Combining nanoscale zero-valent iron with electrokinetic treatment for remediation of chlorinated ethenes and promoting biodegradation: A long-term field study
    (PERGAMON-ELSEVIER SCIENCE LTD, THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND, 2020-01-01) Czinnerová, Marie; Voluščuková, Ondřejka; Marková, Kristýna; Ševců, Alena; Černík, Miroslav; Nosek, Jaroslav
    Nanoscale zero-valent iron (nZVI) is recognized as a powerful tool for the remediation of groundwater contaminated by chlorinated ethenes (CEs). This long-term field study explored nZVI-driven degradation of CEs supported by electrokinetic (EK) treatment, which positively affects nZVI longevity and migration, and its impact on indigenous bacteria. In particular, the impact of combined nZVI-EK treatment on organohalide-respiring bacteria, ethenotrophs and methanotrophs (all capable of CE degradation) was assessed using molecular genetic markers detecting Dehalococcoides spp., Desulfitobacterium spp., the reductive dehalogenase genes vcrA and bvcA and ethenotroph and methanotroph functional genes. The remediation treatment resulted in a rapid decrease of the major pollutant cis-1,2-dichloroethene (cDCE) by 75% in the affected area, followed by an increase in CE degradation products methane, ethane and ethene. The newly established geochemical conditions in the treated aquifer not only promoted growth of organohalide-respiring bacteria but also allowed for the concurrent presence of vinyl chloride- and cDCE-oxidizing methanotrophs and (especially) ethenotrophs, which proliferated preferentially in the vicinity of an anode where low levels of oxygen were produced. The nZVI treatment resulted in a temporary negative impact on indigenous bacteria in the application well close to the cathode; but even there, the microbiome was restored within 15 days. The nZVI-EK treatment proved highly effective in reducing CE contamination and creating a suitable environment for subsequent biodegradation by changing groundwater conditions, promoting transport of nutrients and improving CE availability to soil and groundwater bacteria.
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    Comparison of the Effectiveness of Various Structures of Regulators for Controlling an Object of the Sixth Order
    (Institute of Electrical and Electronics Engineers Inc., 2019-01-01) Zhmud, Vadim; Dimitrov, Lubomir; Nosek, Jaroslav; Roth, Hubert
    Object control requires the calculation of a regulator. One of the most effective methods for calculating the regulator is the method of numerical optimization of the regulator. This paper discusses the solution of the problem of controlling a linear object of the sixth order, the parameters of which are such that this high order significantly and negatively affects the possibilities of successfully managing this object. Using the traditional approach to the design problem of the controller (regulator) allows us to formally solve the problem; however, the result of this solution is not satisfactory. The use of additional derivation does not give any noticeable improvement. A solution to this problem is proposed by using pseudo-local feedback, moreover, this connection is supposedly most effective if it covers one of two identical links in the object model. This allows for a smoother attenuation of the frequency response of the object in the region where the action of these two links begins to affect. For pseudo-local communication, an additional PID controller is used, the coefficients of which are also determined by the method of numerical optimization. The optimization result allows us to conclude that the presence of an integral element in this controller is optional. The calculation result of such a composite controller meets the most stringent requirements for the quality of control, since in such a system the speed is increased at least twice, the oscillations, which were about 10% in amplitude, are completely eliminated, the robustness of the system is ensured, which is verified by changing all the controller coefficients by 5% up and down, and also by changing the time constant of the element of the pseudolocal loop by 10% up and down, changes in the transition process of the system in this case remain are acceptable.
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    COST-EFFECTIVE REMEDIATION USING MICROSCALE ZVI: COMPARISON OF COMMERCIALLY AVAILABLE PRODUCTS
    (SOC ECOLOGICAL CHEMISTRY & ENGINEERING, OPOLE UNIV, OLESKA 48, OPOLE, 45-951, POLAND, 2020-01-01) Pavelková, Alena; Stejskal, Vojtěch; Vološčuková, Ondřejka; Nosek, Jaroslav
    Zero-valent iron is very effective in the treatment of groundwater contaminated with chlorinated hydrocarbons and solvents broadly used in industrial production. In terms of its sustainability and cost, a legitimate effort has been devoted to the optimization of the remediation process, which can be demanding and expensive. In this study, the application potential and fundamental properties of several commercial micro-sized zero-valent iron (mu ZVI) were investigated. Although the manufacturers report the basic parameters of mu ZVI, it has been shown that the actual reactivity of apparently similar products varies notably. This work was focused on monitoring of frequently occurring contaminants. The actual contaminated water from the Pisecna locality former landfill of industrial waste, with high levels of chlorinated ethenes and ethanes (PCE, TCE, cis-1,2-DCE and 1,2-DCA) was used for the experiment. The degree of dechlorination reached over 85 % 32 days after the application of mu ZVI in several samples and a far higher reaction rate for smaller particles was observed. Also, the amount of cis-1,2-DCE, which is characterized by slow decomposition, decreased by more than 95 % over the course of the experiment. Smaller particles showed a much longer sedimentation rate and gradual fractionation was also observed. Monitoring of ORP and pH also suggested that the smaller particles possessed a reduction capacity that was sufficiently high even at the end of the experiment. Laboratory tests with apparently similar mu ZVI samples indicated considerable differences in their reaction rate and efficiency.
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    Domain phenomena in single crystalline and ceramic ferroics: Unresolved and attractive problems
    (Technická Univerzita v Liberci, 2003-01-01) Fousek, Jan; Cross, Leslie Eric; Nosek, Jaroslav
    Domain-related properties of ferroic materials offer a number of application aspects. However, some of the involved domain characteristics have not been fully explained and may initiate an interesting field of further research. Here we specify and discuss several such still unresolved problems related to single crystalline and ceramic samples. Those concerning static domain pattern include the topic of domain wall thickness and of possible macroscopic wall properties, macroscopic properties of ceramic samples depoled in different ways and application of multidomain systems in surface acoustic wave devices. Discussed problems related to dynamic domain phenomena include the issue of visibility and thickness of moving domain walls, the effect of nucleation and the topic of extrinsic contributions to macroscopic properties of multidomain samples. © 2002 Elsevier Science B.V. All rights reserved.
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    Drive level dependence of the resonant frequency in BAW quartz resonators and his modeling
    (IEEE, Piscataway, NJ, United States, 1997-01-01) Nosek, Jaroslav
    Orlando, FL, USA
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    Electric-field enhanced reactivity and migration of iron nanoparticles with implications for groundwater treatment technologies: Proof of concept
    (2019-05-01) Cernik, Miroslav; Nosek, Jaroslav; Filip, Jan; Hrabal, Jaroslav; Elliott, Daniel W.; Zboril, Radek
    The extensive use of nanoscale zero-valent iron (nZVI) particles for groundwater treatment has been limited, in part, because of their non-selective reactivity and low mobility in aquatic environments. Herein, we describe and explore progressive changes in the reactivity and migration of aqueous dispersed nZVI particles under an applied DC electric field. Due to the applied electric field with an intensity of about 1 V cm(-1), the solution oxidation-reduction potential (ORP) remained as low as -200 mV for at least 32 days, which was in agreement with the persistence of the reduced iron species (mainly Fe(II)), and led to substantially prolonged reactivity of the original nZVI. The treatment of chlorinated ethenes (DCE > PCE > TCE) was markedly faster, individual CHC compounds were eliminated with the same kinetics and no lesser-chlorinated intermediates were accumulated, following thus the direct dechlorination scheme. When nZVI-dispersion flows towards the anode through vertical laboratory columns filled with quartz sand, significant enhancement of nZVI migration was recorded because of lower extent of nanoparticle aggregation and increased repulsion forces between the nanoparticles and the surface of silica dioxide. The results of this study have significant consequences for groundwater remediation, mainly for the treatment of slowly degradable DCE in real CHC contaminated groundwater, where it could improve the reactivity, the longevity and the migration of nZVI particles. (C) 2019 Elsevier Ltd. All rights reserved.
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    Exkurze do Národní technické knihovny
    (2024-04-12) Nosek, Jaroslav; UKN
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    Ferroelectric domain structures in PZN-8%PT single crystals studied by scanning force microscopy
    (Technická Univerzita v Liberci, 2001-01-01) Abplanalp, M.; Barošová, Dagmar; Bridenbaugh, P.; Erhart, Jiří; Fousek, Jan; Günter, Peter N.; Nosek, Jaroslav; Šulc, Miroslav
    Domain structures in unpoled PZN-8%PT single-crystal (001) plates have been investigated by scanning force microscopy in the piezoresponse mode, at room temperature. Regular fingerprint structure of nonferroelastic domains with antiparallel polarization (of typical width 1-2 μm) has been observed. Compared to domain patterns usually observed in other materials, domains are rather diffuse, with irregular domain walls. The latter are preferably oriented parallel to {211}- or {231}-type planes. Antiparallel polarization switching induced by local application of electric field was clearly demonstrated. Probable ferroelastic (110) domain walls have been also identified and corresponding domain structures have been analyzed. © 2001 Elsevier Science Ltd.
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    Fotografie – co s nimi
    (2016-11-03) Nosek, Jaroslav; Univerzitní knihovna TUL
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    Laboratorní výzkum a modelování transportních vlastností nanoželeza
    (Technická Univerzita v Liberci, 2009-01-01) Nosek, Jaroslav
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    Laboratorní výzkum elektroredukce chlorovaných uhlovodíků.
    (Technická Univerzita v Liberci, 2012-01-01) Cádrová, Lucie; Nosek, Jaroslav
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    Laboratory Comparison of Nzvi / S-nzvi Efficiency in Systems with And Without Power
    (2019-01-01) Vološčuková Ondřejka; Skácelová, Petra; Pavelková, Alena; Slunský, Jan; Nosek, Jaroslav
    The use of nZVI is well known method for remediation of groundwater contaminated with chlorinated hydrocarbons. The present paper investigates the ability of traditional nZVI and S-nZVI modified with sulphide ion (HS- ) to reduce CHC in real wastewater sample. In the effort to enhance longevity and efficiency of the treatment, experiments were performed under applied voltage (patent 304152, owner MEGA a.s., TUL). Results showed elevated reactivity of nZVI in reactors with passing voltage. The decomposition of the CHC in DC supported reactors occurred several times faster than in reactors without added voltage. However, the analysis of products suggests different pathway of decomposition when S-nZVI is used. The main product of reductive dechlorination was acetylene as opposite to regular nZVI which produced predominantly ethene and ethane. The nZVI provided with DC showed the most rapid decline of all contaminants in the time frame of 5 days.
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    Měření elektrických a tepelných vlastností geopolymerů.
    (Technická Univerzita v Liberci, 2011-01-01) Polášek, Tomáš; Nosek, Jaroslav
    Bakalářská práce je zaměřena na měření elektrických a tepelných vlastností geopolymerů. Práce je rozdělana na dvě části. První část obsahuje rešerši k měření. V ní jsou zapsány definice důležitých pojmů k měření, vzorce pro výpočty a důkladně popsány typy pro jednotlivá měření. Druhá část práce je experimentální. Obsahuje podrobný popis obou měření vodivosti. Výsledky získané z těchto měření jsou zapsány do tabulek a zpracovány do grafů. V závěru práce jsou jednotlivé měřené vzorky porovnány mezi sebou a poté jsou vybrány takové, které vykazují nejlepší vlastnosti. Tyto vzorky poté poslouží k určení směru vývoje, pro získání ještě lepších vlastností geopolymerů.
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    Modernizace výrobního interferometru a vývoj řídícího software
    (2014-10-20) Nosek, Jaroslav; Lédl Vít, Ing. Ph.D.; Skolitel : 54889 Fárek Jiří, prof. Ing. CSc.; Konzultant : 61197 Psota Pavel, Ing. Ph.D.; Konzultant2 : 64392 Vojtíšek Petr, Ing.
    Interferometrie je nejpoužívanějším nástrojem k přesnému měření optických elementů. V nedávné době byl v centru TOPTEC zrenovován hardware rovinného výrobního interferometru, avšak po stránce softwarové nedošlo doposud k žádnému progresu. Práce popisuje základní postupy a algoritmy implementované do vyhodnocovací jednotky interferometru tak, aby následovala moderní trendy optického průmyslu.
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    Nedamy (Teambuilding 2017)
    (Technická univerzita v Liberci, 2017-11-20) Nosek, Jaroslav; Univerzitní knihovna TUL