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Electrospun fibers based on PVDF and nylon
Černohorský, Petr ; Sobola, Dinara (referee) ; Papež, Nikola (advisor)
Polymer nanofibers used for the construction of triboelectric nanogenerator (TENG) and piezoelectric nanogenerator (PENG) are new and promising technologies for energy recovery. Thanks to the generation of electrical energy based on mechanical movement (deformation), these fibers can find application in the field of self-powered electronic devices. In this work, three nanofibrous structures of materials were prepared by electrostatic spinning: pure polyvinylidene fluoride (PVDF), pure polyamide-6 (PA6) and their mixed combination PVDF / PA6. Non-destructive analyzes such as Raman spectroscopy, FTIR, XPS and electron microscopy were used to study the properties of nanofibers. Analyzes confirmed the positive effect of electrostatic spinning of polymers on the support of the formation of highly polar crystalline -phase in PVDF and , -phase in PA6. The structure arrangement of the nanofibrous material and their defects were observed by scanning electron microscopy (SEM). Furthermore, the contact angle of the wettability of the liquid on the surface was measured for the materials, and the permittivity was measured to monitor the dielectric properties. The described results make the mixed material PVDF / PA6 very promising for further research in the field of nanogenerators and functional textiles.
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Development of DC arc quenching chamber
Černohorský, Petr ; Valenta, Jiří (referee) ; Šimek, David (advisor)
Seminar thesis focuses on the issues about quenching the electric direct arc by the quanching system. Teoretical part deals with action about quanching the direct arc and with another actions which happens in direc discharge. There is described proposal and construction of the insulating quenching system. Than chamber was testing in high voltage laboratory and the results from testing was evaluated.
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Electrospun fibers based on PVDF and nylon
Černohorský, Petr ; Sobola, Dinara (referee) ; Papež, Nikola (advisor)
Polymer nanofibers used for the construction of triboelectric nanogenerator (TENG) and piezoelectric nanogenerator (PENG) are new and promising technologies for energy recovery. Thanks to the generation of electrical energy based on mechanical movement (deformation), these fibers can find application in the field of self-powered electronic devices. In this work, three nanofibrous structures of materials were prepared by electrostatic spinning: pure polyvinylidene fluoride (PVDF), pure polyamide-6 (PA6) and their mixed combination PVDF / PA6. Non-destructive analyzes such as Raman spectroscopy, FTIR, XPS and electron microscopy were used to study the properties of nanofibers. Analyzes confirmed the positive effect of electrostatic spinning of polymers on the support of the formation of highly polar crystalline -phase in PVDF and , -phase in PA6. The structure arrangement of the nanofibrous material and their defects were observed by scanning electron microscopy (SEM). Furthermore, the contact angle of the wettability of the liquid on the surface was measured for the materials, and the permittivity was measured to monitor the dielectric properties. The described results make the mixed material PVDF / PA6 very promising for further research in the field of nanogenerators and functional textiles.
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Development of DC arc quenching chamber
Černohorský, Petr ; Valenta, Jiří (referee) ; Šimek, David (advisor)
Seminar thesis focuses on the issues about quenching the electric direct arc by the quanching system. Teoretical part deals with action about quanching the direct arc and with another actions which happens in direc discharge. There is described proposal and construction of the insulating quenching system. Than chamber was testing in high voltage laboratory and the results from testing was evaluated.
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Modelling and Optimization of Processes at an Operational Level
Cerman, Tomáš ; Voráček, Jan (advisor) ; Černohorský, Petr (referee)
Theses is devided into two parts, the first one is dealing with theory the other one with practical exercise. There is basic terminology set in the first part, focusing mainly on process management and methodologies leading the current evolution in that respect, Lean and Six Sigma. I also refer about tools for mapping the processes and devote a section to theory of queues which is a main subject for modelling in the practical part. I have not omitted to mention axioms for modeling itself. Practical part comes from job experience I had. Main goal is to set up a model simulation based on the main features of the process structure, involve main principles of mentioned methodologies and to discuss the results simulation brings.
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