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Carbon materials for power sources
Tichý, Jiří ; Bača, Petr (referee) ; Novák, Vítězslav (advisor)
This work deals with carbon materials and using them in electrochemical energy sources. Object of this work was to prepare carbon materials and investigate their electrical properties. The theoretical part objects of the carbon materials, their properties, application in electrochemical energy sources and measurement methods used in experimental part. Experimental part describes the preparation of the electrodes with various carbon materials and summarizes the results of measurements.
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Flexible structure development for efficient heat transfer
Černoch, Jakub ; Lazar, Václav (referee) ; Mašek, Jakub (advisor)
Diplomová práce se zabývá teoretickými výpočty a návrhem struktury pro přenos tepla, která je součástí Miniaturizovaného tepelného spínače podle zadaných požadavků Evropské Kosmické Agentury. Základními parametry jsou nízká hmotnost a vysoká tepelná vodivost. Práce navazuje na spínač navržený firmou Arescosmo, který nesplňoval požadované limity zejména v oblasti hmotnosti a tepelné vodivosti. Pomocí teoretických výpočtů hmotnosti a tepelné vodivosti bylo ověřeno 49 variant ve třech základních konceptech – Mechanická struktura, flexibilní struktura složená z drátků a foliová struktura. Z hlediska tepelné vodivosti jako nejlepší struktury vycházejí ty, které jsou založené na použití ochranných kovových opletů. Z dostupných zdrojů byly rovněž navrženy technologie, které by bylo možné využít pro výrobu těchto struktur. Pro splnění požadavků, bude v další fázi projektu nutné vyrobit experimentální vzorky na kterých budou teoretické výpočty a vybrané technologie ověřeny.
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Purification of Producer Gas in Biomass Gasification using Carbon Materials
Al-Dury, Sausan Salem Kadam ; Klemeš,, Jiri (referee) ; Noskievič, Pavel (referee) ; Skála, Zdeněk (advisor)
This work is dealing with the utilization of biomass feed stocks and wooden residue for gasification process to produce syn-gas suitable for the implementation of power plants for electricity generation and problem of gas production suitable for further chemical and energy purpose discussing the suitable practical purification methods, given that the complexity of theme and project which carried out through detailed analysis. Since the obtained gas has many types of unwanted contaminants. It was necessary to derive an effective cleaning method for gas purification from chemical contaminants especially tars components. The discussion of the definitions and methods for the determination of gas unwanted components and their removal technologies on the basis of the knowledge of data, collecting and analysis carried out through an experimental massive approach. The theoretical analysis of the gasification process for an effective tar reduction in the produced gas has been studied as well. Since the quality requirements for internal combustion engines, gas turbines and fuel cells using the primary measurement methods cannot be achieved for gas production, this work aimed removing different particulates and tar. The main emphasis is placed on the methods of high cleaning taking in account the chemical and thermal specifications of the gas which is based on the utilization of three different kinds of carbon materials successfully and efficiently char coal, black coke and active carbon for tar removal which has a major impact on the process parameters. The analysis was responding with the mechanism and the techniques of minimizing the resultant allowable concentration by using a suitable materials and verifying the operation conditions without affecting the gas thermal efficiency. The highlights of the theoretical and experimental work has been drawn up by a high concept cleaning allowing the production of a pure gas having a quality that meets the modern technical requirements for electricity generation. Functionality the most efficient cleaning methods were based in the current project for tar reduction on the quantity of tar removed, the materials used for tar cracking and the conditions of the experimental work as well. For a successful application, some proposals have been settled for industrial applications of gas cleaning.
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Low Temperature Fuel Cells H2-O2 with Anionic and Bipolar Membrane
Barath, Peter ; Sedlaříková, Marie (advisor)
The doctoral thesis deals with investigation of the catalysts and ionexchanege membranes for fuel cells H2-O2. The work contains the basic principles of chemical reactions, thermodynamic aspects and kinetic properties in PEM fuel cells.Ion-exchagers based on fluorinated polymer sulfonic acids known as NAFION are used in most cases. These compounds are very expensive. Also a strong corrosive attribute requires platinum as a catalysator. These facts make the membrane fuel cells fully non-competetive with e.g. internal combustion engine in spite of all ecological advantages of this electrical power source. The subject of doctoral thesis is research and development of compounds for the composite electrode materials base on NiOx, Ni-Pd and Raney Ni suitable as catalysts a nd alkaline or bipolar ionexchange membranes for electrochemical fuel cells.
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Carbon materials for power sources
Tichý, Jiří ; Novák, Vítězslav (referee) ; Barath, Peter (advisor)
This work deals with carbon materials and using them in alternative energy sources. Object of this work was prepared electrodes with carbon materials and investigate their electrical properties. The practical part objects of the carbon materials, their properties and application in fuel cells and Ni-Cd batteries. Analysis describes the electrochemical processes in electrode materials with carbon as conductive element.
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Preparation of graphene quantum dots and study of their properties
Zdražil, Lukáš ; Mikula, Milan (referee) ; Zmeškal, Oldřich (advisor)
Current methods for preparing graphene quantum dots (GQDs) rely on oxidation and reducing agents or require energy-intensive and technologically demanding preconditions. Applying microwave expansion and liquid phase exfoliation (LPE) in a sample of graphite powder enabled us to prepare GQDs that exhibit strong luminescence in the blue region of the visible spectrum. The proposed technique for synthesizing GQDs is energetically undemanding and does not necessitate additional chemical components.
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Flexible structure development for efficient heat transfer
Černoch, Jakub ; Lazar, Václav (referee) ; Mašek, Jakub (advisor)
Diplomová práce se zabývá teoretickými výpočty a návrhem struktury pro přenos tepla, která je součástí Miniaturizovaného tepelného spínače podle zadaných požadavků Evropské Kosmické Agentury. Základními parametry jsou nízká hmotnost a vysoká tepelná vodivost. Práce navazuje na spínač navržený firmou Arescosmo, který nesplňoval požadované limity zejména v oblasti hmotnosti a tepelné vodivosti. Pomocí teoretických výpočtů hmotnosti a tepelné vodivosti bylo ověřeno 49 variant ve třech základních konceptech – Mechanická struktura, flexibilní struktura složená z drátků a foliová struktura. Z hlediska tepelné vodivosti jako nejlepší struktury vycházejí ty, které jsou založené na použití ochranných kovových opletů. Z dostupných zdrojů byly rovněž navrženy technologie, které by bylo možné využít pro výrobu těchto struktur. Pro splnění požadavků, bude v další fázi projektu nutné vyrobit experimentální vzorky na kterých budou teoretické výpočty a vybrané technologie ověřeny.
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Preparation of graphene quantum dots and study of their properties
Zdražil, Lukáš ; Mikula, Milan (referee) ; Zmeškal, Oldřich (advisor)
Current methods for preparing graphene quantum dots (GQDs) rely on oxidation and reducing agents or require energy-intensive and technologically demanding preconditions. Applying microwave expansion and liquid phase exfoliation (LPE) in a sample of graphite powder enabled us to prepare GQDs that exhibit strong luminescence in the blue region of the visible spectrum. The proposed technique for synthesizing GQDs is energetically undemanding and does not necessitate additional chemical components.
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Purification of Producer Gas in Biomass Gasification using Carbon Materials
Al-Dury, Sausan Salem Kadam ; Klemeš,, Jiri (referee) ; Noskievič, Pavel (referee) ; Skála, Zdeněk (advisor)
This work is dealing with the utilization of biomass feed stocks and wooden residue for gasification process to produce syn-gas suitable for the implementation of power plants for electricity generation and problem of gas production suitable for further chemical and energy purpose discussing the suitable practical purification methods, given that the complexity of theme and project which carried out through detailed analysis. Since the obtained gas has many types of unwanted contaminants. It was necessary to derive an effective cleaning method for gas purification from chemical contaminants especially tars components. The discussion of the definitions and methods for the determination of gas unwanted components and their removal technologies on the basis of the knowledge of data, collecting and analysis carried out through an experimental massive approach. The theoretical analysis of the gasification process for an effective tar reduction in the produced gas has been studied as well. Since the quality requirements for internal combustion engines, gas turbines and fuel cells using the primary measurement methods cannot be achieved for gas production, this work aimed removing different particulates and tar. The main emphasis is placed on the methods of high cleaning taking in account the chemical and thermal specifications of the gas which is based on the utilization of three different kinds of carbon materials successfully and efficiently char coal, black coke and active carbon for tar removal which has a major impact on the process parameters. The analysis was responding with the mechanism and the techniques of minimizing the resultant allowable concentration by using a suitable materials and verifying the operation conditions without affecting the gas thermal efficiency. The highlights of the theoretical and experimental work has been drawn up by a high concept cleaning allowing the production of a pure gas having a quality that meets the modern technical requirements for electricity generation. Functionality the most efficient cleaning methods were based in the current project for tar reduction on the quantity of tar removed, the materials used for tar cracking and the conditions of the experimental work as well. For a successful application, some proposals have been settled for industrial applications of gas cleaning.
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