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Preparation of one-dimensional chemical sensors of metal oxide
Sixtová, Kateřina ; Nováková, Jaroslava (advisor) ; Kúš, Peter (referee)
In this thesis, the preparation of a chemical sensor that uses a one-dimensional structure as a sensitive part is studied. First, a scanning electron microscope (SEM) was used to examine the following structures: zinc oxide nanorods, tungsten oxide nanorods, and gallium-doped zinc oxide nanorods. To verify their composition, energy-dispersive X-ray spectroscopy (EDX) was performed. Three chips were examined as well, one of which was then selected for the subsequent preparation of the nanosensor. This was achieved by lifting the structure from the substrate using a nanomanipulator integrated into the microscope with an inserted tungsten tip and placing it on a contact of the chip. To attach the nanorod to the tip, two methods were used. The first one used electrostatic attraction between the rods and the tip, while the second one was based on the deposition of platinum on the rod-tip contact using a focused ion beam (FIB) and a gas injection system (GIS).
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Study of thin film catalysts for direct methanol fuel cell anode
Fusek, Lukáš ; Matolín, Vladimír (advisor) ; Nováková, Jaroslava (referee)
This thesis is focused on the study of catalyst layers for direct methanol fuel cell anode prepared by a new method using magnetron sputtering. Homemade as well as commercial supports were used. The study of properties of prepared layers was carried out in fuel cell using methods of electrochemical analysis, such as electrochemical impedance spectroscopy and cyclic voltametry for examination of conductivity, catalyst activity and resistance to poisoning by residual carbon species. Polarization curves were used to investigate power and diffusion properties. A reference cell composed of commercially-available electrodes was chosen for comparison.
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Study of Pt-CeOx catalytic layers in simulated fuel cell conditions
Dinhová, Thu Ngan ; Nováková, Jaroslava (advisor) ; Tsud, Nataliya (referee)
The diploma thesis concerns the study of catalytic layers Pt-CeOx used in Proton-Exchange Membrane Fuel Cells. Employing a Transmission Electron Microscope and Near-Ambient Pressure Photoelectron Spectroscopy, morphology, particle size distribution, chemical composition, and effects of fuel cell conditions were studied. This work contributes to the clarification of the dynamic character of the prepared catalytic layers in reactive conditions, which is essential for understanding their catalytic activity and durability.
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Study of the effect of thin film catalyst morphology on efficiency of water electrolyzer with proton conducting membrane
Hrbek, Tomáš ; Matolín, Vladimír (advisor) ; Nováková, Jaroslava (referee)
Title: Study of the effect of thin film catalyst morphology on efficiency of water electrolyzer with proton conducting membrane Author: Tomáš Hrbek Department: Department of Surface and Plasma Science Supervisor: prof. RNDr. Vladimír Matolín, DrSc., Department of Surface and Plasma Science Abstract: This bachelor thesis deals with the possibility of reducing the amount of noble metals in catalytic layers of proton exchange water electrolyzer (PEM-WE). The PEM-WE is an important unit of hydrogen economy as it allows storage of excess energy from renewable sources in the form of chemical energy. In the first part, etched membrane electrolyzers were prepared and tested, membrane etching is a previously unpublished procedure leading to a reduction of the amount of catalyst. Etched membranes were studied by scanning electron microscopy and, consequently tested in real working conditions in electrolyzers. In the second part of the work; Ir and IrO2 were compared as catalysts for PEM-WE anode. Their in-cell performance was tested directly in the electrolysers and in controlled condition by rotating disk electrode. Keywords: electrolyzer, magnetron sputtering, thin-layer catalyst, etched mem- brane PEM, Ir vs. IrO2
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Study of thin film catalysts for direct methanol fuel cell anode
Fusek, Lukáš ; Matolín, Vladimír (advisor) ; Nováková, Jaroslava (referee)
This thesis is focused on the study of catalyst layers for direct methanol fuel cell anode prepared by a new method using magnetron sputtering. Homemade as well as commercial supports were used. The study of properties of prepared layers was carried out in fuel cell using methods of electrochemical analysis, such as electrochemical impedance spectroscopy and cyclic voltametry for examination of conductivity, catalyst activity and resistance to poisoning by residual carbon species. Polarization curves were used to investigate power and diffusion properties. A reference cell composed of commercially-available electrodes was chosen for comparison.
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Investigation of thin films for hydrogen fuel cells
Komárková, Zuzana ; Matolín, Vladimír (advisor) ; Nováková, Jaroslava (referee)
Clean and highly efficient energy source has long been sought to solve energy and environmental problems. Fuel cells, which convert the chemical energies sto- red in fuel directly into electrical energy, are expected to be the key technology. In this thesis the catalytic active layers (specifically Pt, PtCo, PtNi, PtRu) for Direct methanol fuell cell (DMFC) are studied. We have evaluated PtCo as the best cathode catalysts. We have significantly reduced the amount of platinum as well as the power loss at higher concentrations of methanol. The sputtered PtCo catalyst is comparable power density in comparison with commercial Pt catalyst while the specific power per gram of platinum is several times higher. The speci- fic power of our anode catalyst layers is comparable to reference catalysts. Our findings are useful for future improvements of the anode catalyst layer for DMFC.
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Treatment of cardiac arrhythmias related to nursing care
NOVÁKOVÁ, Jaroslava
Nursing care continuing the treatment of cardiac arrhythmias is an inseparable part of the patient?s care. As there are various types of arrhythmias and different types of treatment, similarly, the subsequent nursing care has its specifics as well. It relates not only to the post-treatment care but also to pre-surgery preparation and subsequent education. The theoretical part of the thesis contains the information on arrhythmias, their development and treatment. Organizations associating nurses working in arrhythmologic centres are mentioned as well. The practical part consists of the survey research. The quantitative enquiry is conducted in arrhythmologic centres by means of questionnaires addressing the nurses. The qualitative part contains interviews with patients who underwent some of the types of cardiac arrhythmia treatment. The objective of the thesis was to find out whether the nurses are aware of the specifics of the nursing care that follows the treatment of cardiac arrhythmia, in which stage the treatment is the most demanding for nurses and whether they can apply standardized nursing procedures in their work. Another objective is focused on mapping of the educative activity within the nursing care. Interviews with the patients are aimed at the areas of admission, prior to surgery, after surgery and during education. They should outline the view from ?the other side?. All the defined hypotheses were confirmed. The cardinal hypothesis of the thesis was the assumption that nurses, when providing nursing care to patients undergoing treatment of cardiac arrhythmias, do not work according to standardized nursing procedures. Subsequently, a draft of standardized nursing procedure focused on nursing care of patients undergoing implantation of a permanent cardiostimulator was prepared ? it could be applied in the University Hospital in Plzeň where most of the enquiry was conducted.
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