Ústav teoretické a experimentální elektrotechniky

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    Comparing efficiencies of polypropylene treatment by atmospheric pressure plasma jets
    (WILEY-V C H VERLAG GMBH, 2023-07-11) Polášková, Kateřina; Ozkan, Alp; Klíma, Miloš; Jeníková, Zdeňka; Buddhadasa, Madhuwanthi; Reniers, François; Zajíčková, Lenka
    Plasma treatment of polypropylene (PP) is a well-established method of improving its surface properties. However, the efficiencies of different plasma discharges are seldom compared. Herein, we discuss the differences in PP treated by three arc-based commercial plasma jets working in dry air, Plasmatreat rotating plasma jet (PT-RPJ), AFS PlasmaJet & REG; (AFS-PJ), and SurfaceTreat gliding arc jet (ST-GA), and by the low-temperature RF plasma slit jet (RF-PSJ) working in argon. The AFS-PJ has a significantly different reactive species composition dominated by nitrogen oxides. It induced higher thermal loads leading to surface damage. The other arc-based jets (PT-RPJ and ST-GA) created the PP surface with higher oxygen and nitrogen concentration than the low-temperature RF-PSJ. It induced a higher adhesion strength measured on PP-aluminum joints.
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    Enhanced Adhesion of Electrospun Polycaprolactone Nanofibers to Plasma-Modified Polypropylene Fabric
    (MDPI, 2023-03-28) Janů, Lucie; Dvořáková, Eva; Polášková, Kateřina; Janůšová, Martina; Ryšánek, Petr; Chlup, Zdeněk; Kruml, Tomáš; Galmiz, Oleksandr; Nečas, David; Zajíčková, Lenka
    Excellent adhesion of electrospun nanofiber (NF) to textile support is crucial for a broad range of their bioapplications, e.g., wound dressing development. We compared the effect of several low- and atmospheric pressure plasma modifications on the adhesion between two parts of composite-polycaprolactone (PCL) nanofibrous mat (functional part) and polypropylene (PP) spunbond fabric (support). The support fabrics were modified before electrospinning by low-pressure plasma oxygen treatment or amine plasma polymer thin film or treated by atmospheric pressure plasma slit jet (PSJ) in argon or argon/nitrogen. The adhesion was evaluated by tensile test and loop test adapted for thin NF mat measurement and the trends obtained by both tests largely agreed. Although all modifications improved the adhesion significantly (at least twice for PSJ treatments), low-pressure oxygen treatment showed to be the most effective as it strengthened adhesion by a factor of six. The adhesion improvement was ascribed to the synergic effect of high treatment homogeneity with the right ratio of surface functional groups and sufficient wettability. The low-pressure modified fabric also stayed long-term hydrophilic (ten months), even though surfaces usually return to a non-wettable state (hydrophobic recovery). In contrast to XPS, highly surface-sensitive water contact angle measurement proved suitable for monitoring subtle surface changes.
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    Automated Design and Integration of Asset Administration Shells in Components of Industry 4.0
    (MDPI, 2021-03-12) Arm, Jakub; Benešl, Tomáš; Marcoň, Petr; Bradáč, Zdeněk; Schröder, Tizian; Belyaev, Alexander; Werner, Thomas; Braun, Vlastimil; Kamenský, Pavel; Zezulka, František; Diedrich, Christian; Dohnal, Přemysl
    One of the central concepts in the principles of Industry 4.0 relates to the methodology for designing and implementing the digital shell of the manufacturing process components. This concept, the Asset Administration Shell (AAS), embodies a systematically formed, standardized data envelope of a concrete component within Industry 4.0. The paper discusses the AAS in terms of its structure, its components, the sub-models that form a substantial part of the shell's content, and its communication protocols (Open Platform Communication-Unified Architecture (OPC UA) and MQTT) or SW interfaces enabling vertical and horizontal communication to involve other components and levels of management systems. Using a case study of a virtual assembly line that integrates AASs into the technological process, the authors present a comprehensive analysis centered on forming AASs for individual components. In the given context, the manual AAS creation mode exploiting framework-based automated generation, which forms the AAS via a configuration wizard, is assessed. Another outcome consists of the activation of a virtual assembly line connected to real AASs, a step that allows us verify the properties of the distributed manufacturing management. Moreover, a discrete event system was modeled for the case study, enabling the effective application of the Industry 4.0 solution.
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    A Real Model of a Micro-Grid to Improve Network Stability
    (MDPI, 2017-07-30) Marcoň, Petr; Szabó, Zoltán; Veselý, Ivo; Zezulka, František; Sajdl, Ondřej; Roubal, Zdeněk; Dohnal, Přemysl
    This paper discusses the smart energy model of a smart grid using a significant share of renewable energy sources combined with intelligent control that processes information from a smart metering subsystem. An algorithm to manage the microgrid via the demand-response strategy is proposed, accentuating the requirement that the total volume of energy produced from renewable sources is consumed. Thus, the system utilizes the maximum of renewable sources to reduce CO2 emissions. Another major benefit provided by the algorithm lies in applying the current weather forecast to predict the amount of energy in the grid; electricity can then be transferred between the local and the main backup batteries within the grid, and this option enables the control elements to prepare for a condition yet to occur. Individual parts of the grid are described in this research report together with the results provided by the relevant algorithm.
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    Asset Administration Shell as the Key Enabler of the Industry 4.0 Phenomenon
    (Elsevier, 2024-08-30) Arm, Jakub; Kaczmarczyk, Václav; Benešl, Tomáš; Marcoň, Petr; Jirgl, Miroslav; Bradáč, Zdeněk
    With the advent of the Industry 4.0 concept, the digitization of industrial production enterprises and the development of technologies that enabled the transformation of production into a so-called smart factory accelerated. One of the core components of this modern factory is the I4.0 component consisting of a resource and its virtual envelope (AAS). It is the virtual envelope that forms the complex digital twin of the resource and enables interaction with the environment. The AAS standard is gradually being formed, while there are already parts enabling the design and implementation of the so-called passive part of AAS. Using the theory, the original idea is transformed into a semi-formal description, which can already be implemented in various applications. Other technologies such as OPC UA, REST API, TSN are connected with AAS and its deployment, which ensure communication and the implementation itself. This paper discusses various aspects that are related to the role, design and implementation of AAS in various applications.