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High Temperature Processes in Silicon Solar Cells Production
Frantík, Ondřej ; Hudec, Lubomír (referee) ; Banský,, Juraj (referee) ; Szendiuch, Ivan (advisor)
The thesis is focused on high temperature processes in crystalline solar cells production. Main topic is diffusion of traditional dopants phosphorus and boron. Diffusion processes for creating solar cells are different from classical diffusion in semiconductor industrial. It is reason why the thesis describes crated layers in detail. Knowledge of diffusion processes is used for creating bifacial solar cells and development of a new phosphorus emitter for conventional solar cells. Bifacial cells are a new type of cells. Developed new emitter increases efficiency and decreases cost of solar cells production. Another part the thesis is devoted to the prediction of diffusion processes. New models of phosphorus and boron diffusion for photovoltaic industrial are created in software SILVACO. Models correspond with real results.
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Phosphorus recovery from liquid digestate
Heger, Jan ; Procházková, Michaela (referee) ; Touš, Michal (advisor)
The focus of this thesis is the posibility of obtaining phosphorus from liquid digestate. The theoretical part of the thesis is focused on summarizing the current situation regarding phosphorus recovery. The research summarizes the essential information about the method of struvite precipitation, by which phoshphorus is obtained in the form of struvite, which can be further used as a fertilizer. Based on the process information, an experimental device was designed to obtain phosphorus in the form of struvite, corresponding to industry standards. It is a cylindrical vessel with a conical bottom, in which the liquid digestate with the chemicals is mixed with a stirrer. The functionality of the device was tested experimentally on the created device. The results of the experiment were analyzed by XPS method, which confirmed the formation of struvite. For future operation, modifications of the device and pre-treatment of the liquid digestate were proposed, which could improve the whole process and its results.
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Development of Light Emitting Electroluminescent Device by Means of Material Printing
Hrabal, Michal ; Syrový,, Tomáš (referee) ; Boušek, Jaroslav (referee) ; Vala, Martin (advisor)
Cílem této práce je vývoj světelného zdroje založeného na technologii tlustostěnného elektroluminiscenčního panelu napájeného střídavým napětím (ACPEL). V současné době se jedná se o jedinou technologii založenou na metodách materiálového tisku vhodnou pro přípravu velkoplošných, flexibilních a vzorovaných zdrojů světla. Důraz je v této práci kladen na představení, prozkoumání a odstranění typických problémů, které jsou spojovány s touto technologií. Tyto problémy jsou omezený odstín barvy emitovaného světla a dlouhodobá stabilita elektroluminiscenčního prvku, který je vystaven vlivům prostředí. Rešeršní část dizertační práce je zaměřena na představení a identifikaci depozičních technik, vhodných pro reprodukovatelnou přípravu ACPEL panelů. Dalším cílem je identifikace fyzikálních parametrů, vhodných pro charakterizaci velkoplošných zdrojů světla. Praktickým cílem práce je nalezení vhodné metodologie pro popis a charakterizaci panelů, jakožto plošných světelných zdrojů. Fotometrická veličina jas L a spotřeba elektrické energie P byly vyhodnoceny jako vhodné parametry, určující aplikaci ACPEL panelů. Na modrém panelu bylo dosaženo maximální hodnoty jasu L = 133 cd•m2 při napětí Upp = 500 V a frekvenci f = 1000 Hz. Hodnoty spotřeby elektrické energie, vztažené na jednotkovou plochu panelů zkoumaných v této práci, jsou (7±3) mW. Tyto dosažené hodnoty dělají ze světelných zdrojů založených na ACPEL technologii zajímavé kandidáty pro různé aplikace. Vlivu rostoucí amplitudy a frekvence budícího napětí na dlouhodobou stabilitu panelů je důležitým cílem této práce. Pro popis stability byly zavedeny parametry L50 and L75. Bylo zjištěno, že rostoucí frekvence budícího napětí zkracuje životnost panelů. Laminovaný panel napájený napětím s přibližně trojnásobně vyšší frekvencí vykazoval přibližně třetinové hodnoty parametrů L50 a L75. Nejvyšších hodnot stabilitních parametrů dosahoval panel enkapsulován mezi skleněné pláty – přibližně sedminásobnou hodnotu oproti laminovanému panelu s trojnásobnou frekvencí. Optimální stability panelů lze dosáhnout při nastavení frekvence v rozmezí 400–800 Hz a zapouzdřením mezi sklo. Úzká paleta odstínů barev emitovaného světla je jeden z typických problémů, který dále zkoumán v dizertační práci. Tato práce zkoumá nadějnou metodu, přídavek vhodného materiálu pro konverzi barvy (CCM). Nový derivát diketopyrrolopyrrolu (DPP), absorbující v modré oblasti, byl přidán k modrému fosforu a byl pozorován sedminásobný narůst hodnot absolutního spektrálního ozáření v oblasti vlnových délek odpovídajících maximální emisi CCM materiálu. Jednoduchost přípravy vyvinutých zdrojů světla spolu s velmi nízkou spotřebou a vysokou dobou života dělají z ACPEL panelů zajímavé kandidáty pro podsvícení prvků například v automobilovém průmyslu, pro dekorativní osvětlení, pro „branding“ – zvýraznění reklamních značek.
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Eutrophication of water reservoirs
Kukol, Jan ; Bartoníčková, Eva (referee) ; Biela, Renata (advisor)
The first part of this thesis is focused on general explanation of eutrophication, its causes and consequences. The possible solutions of eutrophication are discussed briefly and a few examples of eutrophic reservoirs in the Czech Republic are added. The second part of this thesis is focused on ongoing modifications of water reservoir Brno and finally the effectiveness of measures are being compared.
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Design of WWTP at locality with extreme demands on quality of treated wastewater
Krupica, Radek ; Vachovec, Roman (referee) ; Hlavínek, Petr (advisor)
This diploma thesis deals with the wastewater treatment technologies by means of which high quality of the treated wastewater is attained, especially with regard to removing nutrients. The introduction of the thesis contains, among others, descriptions of the reserves in the Czech Republic where it is extremely important to insist on the highest quality of the discharged wastewaters. Then follows a summary of the quality requirements on the discharged wastewaters as stipulated in the legislation. Furthermore, I analyse the impact of the nutrients – nitrogen and phosphorus – on the environment and the principles of their removal from the wastewaters. In the next section I concentrate on the technological processes by means of which the required quality of the wastewater is achieved. The conclusion includes a list of technologies used as the tertiary wastewater treatments with emphasis on membrane technologies. The second part of my thesis is a study of a project of a wastewater treatment plant (WWTP) with membrane technology for the villages of Sloup and Šošůvka located within the protected landscape area of Moravian Karst.
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The Study of Intensification of the Constructed Treatment Wetland for the Village of Machová
Zedník, Ondřej ; Pumprlová Němcová, Miroslava (referee) ; Kriška-Dunajský, Michal (advisor)
The village Machová (650 inhabitants) operates a combined sewage system which leads to a treatment wetland. This wastewater treatment plant faces similar problems like most of treatment wetlands from the turn of the last century - it has a low efficiency of the removal of ammonia nitrogen N-NH4 + which causes a negative impact on the watercourses and the environment. The study deals with the technical modification of the operating line which would eliminate the abovementioned problems and solves the sludge treatment in treatment plant. Population growth in the village connected with the construction of sanitary sewer will cause high concentrations of pollution in the inflow. The proposed modification uses the latest scientific knowledge and proven technologies which were created by the Institute of Landscape Water Management. These technologies will secure the low effluent concentrations of monitored parameters not only today but also in case the population of the village will grow.
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Classification of material used for the construction of garden ponds
Sýkora, Jiří ; Repková, Martina (referee) ; Komendová, Renata (advisor)
This thesis deals with the study of the occurrence forms of inorganic phosphorus in water garden ponds and used material impact on the amount of releasable amount of phosphorus in the form of phosphates in the water medium. The practical part of this work focuses on the analysis and subsequent classification of building materials for the production of garden ponds just by releasing ability of phosphorus in the form of phosphates in the water.
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Recovery of waste from processing of phosphorus to produce materials with increased added value
Hejsek, Michal ; Zavřel, Tomáš (referee) ; Ing.Jan Červený, Ph.D. (advisor)
This master thesis focuses on reuse of waste water from industrial plant processing yellow phosphorus. Theoretical part summarizes physical and chemical properties of phosphorus, its transport in biosphere and its role in living organisms. Also the production process of the industrial plant is described. Waste water that contains waste byproducts is considered to be useful source of essential nutrients for economical large scale microalgae cultivation and development of biotechnological processes. In practical part, optimization of growth conditions for microalgae Chlorella pyrenoidosa Chick (IPPAS C-2) cultivation in medium based on wastewater from yellow phosphorus warehouse is presented.
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Harvesting of materials from wastewater and sludge
Boubínová, Marie ; Chorazy, Tomáš (referee) ; Hlavínek, Petr (advisor)
This bachelor thesis is focused on the issue of recycling raw materials from wastewater and sewage sludge with emphasis on phosphorus. The first part of the thesis deals with the problems associated with resources of phosphorus, the use of the legislative and recycling of phosphorus. Then, physico-chemical and biological methods of phosphorus recycling from wastewater and products of their further processing at WWTPs are discussed. Phosphorus recycling is also described in terms of the circular economy, which is explained at the end of the first part of this thesis. The second part of this thesis is a technical-economic research for a specific WWTP over 50 thousand. PE in the Czech Republic. The available technologies for recycling phosphorus from wastewater, sewage sludge and sewage sludge ash are described alsonhere. Then, the technologies are compared and evaluated.
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Pollution of karst watercourses in Říčka river basin
Chlopčíková, Anna ; Tůma, RNDr Antonín (referee) ; Malá, Jitka (advisor)
This bachelor's thesis is focused on the monitoring of pollution parameters in the Moravian Karst area, sampling and the analyses of samples once every 4 weeks. In total, 9 water samples were taken from 8 sampling points. Flow rate, temperature, conductivity, concentration of dissolved oxygen and pH value were measured at each sampling point. Afterwards, content of suspended solids, CODcr, BOD5, ammonia (N-NH4), nitrites (N-NO2), nitrates (N-NO3), organic nitrogen (Norg) and total phosphorus (Ptot) were determined in the samples. At the end of the thesis, the obtained results were compared with each other and with the values stipulated by Government Decree No. 401/2015 Coll. The parameters were processed into tables that provide an overview of average, minimum, and maximum values on each of the sampling points. These tables indicate values that exceed the limits set by the legislation. Also, the change of parameters in time and along the river flow was evaluated from the measured values.
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