The subject of diploma thesis is to gather knowledge in the production and use of hydrogen. This work is devoted to a comparison of the previously existing processes for producing hydrogen, where the vast majority is filled of fossil fuel. Another section is devoted to new materials for the study based on a number of selected patents and the experiment promising new method for decomposition of water. Based on available data will be carried out energy balance and consequently will be drafted energy system using hydrogen as fuel. In conclusion will be future possibilities evaluated in the field of hydrogen energy.

Biomass gasification using air with addition of oxygen can be the right way to increase the quality of the syngas produced. This thesis aims to characterize the gasification process using oxygen-enriched air and verify its effect on the gas. The theoretical part deals with description of the technology with an emphasis on various gasifying agents and different possibilities of increasing gas quality. The practical part contains the results of measurements on the atmospheric fluidized bed reactor and their evaluation. The experiment was performed with various oxygen enrichment taking into account the capabilities of the equipment used.

Nowadays there is research into molten salt reactors. The use of chlorine-based salts, which would be more available than known fluoride salts, is envisaged. The subject of research is not only the chemical and physical properties of chloride salts, but also their behavior in the neutron field and the influence of neutron balance inside the reactor. Many properties can also be determined using calculations that draw information from scientific nuclear libraries (endf). The purpose of this work is to compare important nuclear libraries with each other, and also to compare the reaction rates calculated from the library data with the reaction rates obtained by self-measurement. The preview will include a description of the necessary activities associated with the preparation of measurements, instructions for compiling the computer program NJOY and the process of the measurement itself. At the end of the work will be summarized the results and statements of which nuclear library is the closest in its values to the results of experiments.

This master thesis deals steam generator for ESFR (European Sodium Fast Reactor), which is heated by liquid sodium. In the beginning chapters, there are theoretic information about ESFR's parameters and its' comparison with ohter types of heat exchangers in nuclear reactors with the same principal (sodium as a coolant). Then designing part follows, which contents of introduction of calculations, option of material and conception of heater. Computational part on its own includes thermal, hydraulic and stress calculations and comparison with aspects in nuclear safety and security.

Thesis on Electron beam welding of ODS materials is divided into theoretical and experimental part. In the first part the theoretical research work focuses on the accurate description of the candidate materials in a research fusion reactor ITER. Following are detailed constructional ODS materials and tungsten alloy as a material of the first wall. The second part of the theoretical research deals with various possibilities of joining high-melting dissimilar materials such as brazing or electron beam welding as well, which will be established in the experimental section. The experimental part of the thesis deals with a joining ODS steel MA 956 with sintered carbide WC-Co and ODS tungsten. These materials are welded by electron beam. Individual samples are distinguished used filler material, preheating or welding parameters. This thesis contains photographic documentations of microstructure the welding samples, results from scanning electron microscopy, and measurements of microhardness across the weld metal.

This master thesis deals with polyhydroxyalkanoates (PHA) and their role in bacterial biofilms. In the theoretical part the polyhydroxyalkanoates, bacterial biofilm and the relationship between them were reviewed. The experimental part focused on differences in PHA production by planktonic and biofilm cells. In order to study selected topic, bacterial strains of Burkholderia cepacia and Burkholderia sacchari were cultivated using a CDC biofilm reactor. The attention was paid to quantity and especially to the form in which PHA occurs in planktonic and biofilm cells. Results of Raman spectroscopy have shown that PHA exists exclusively in native amorphous form in planktonic bacterial cells. On the other hand, in biofilm PHA occurs also in a partially crystalline form. In addition, the resistance of planktonic and biofilm cells against various stress factors and the effect of osmotic stress on PHA production was tested too. According to the results of the experiment, when the bacteria were exposed to different stress factors (high temperature, low temperature, presence of detergent and so forth) biofilm cells showed a higher stress resistance than planktonic cells. Apart from slowing cell growth and reproduction, increased osmotic pressure in the culture medium also caused decrease of PHA production. In addition, planktonic cells responded to external stimuli more sensitively than biofilm ones.

<p>Cilj&nbsp; ovog&nbsp; rada&nbsp; bio&nbsp; je&nbsp; ispitivanje&nbsp; mogućnosti&nbsp; primene&nbsp; modifikovanog&nbsp; bentonita&nbsp; kao katalizatora&nbsp; (ferioksalat&nbsp; i&nbsp; Al,&nbsp; Fe-bentonit&nbsp; katalizatori)&nbsp; u&nbsp; Fenton&nbsp; i&nbsp; foto-Fenton&nbsp; procesu&nbsp; uklanjanja tekstilne&nbsp; reaktivne&nbsp; boje&nbsp; Reactive&nbsp; Red&nbsp; 120.&nbsp; Do&nbsp; sada&nbsp; su&nbsp; objavljene&nbsp; studije&nbsp; primene&nbsp; heterogenog Fenton procesa sa različitim koncentracijama gvožđau katalizatorima i sa kompleksom ferioksalata,međutim, njihovo poređenje u smislu efikasnosti obezbojavanja nije istraženo, &scaron;to je bio jedan od fokusa&nbsp; istraživanja&nbsp; u&nbsp; ovom&nbsp; radu.&nbsp; Osim&nbsp; toga,&nbsp; potencijal&nbsp; sunčeve&nbsp; energije&nbsp; predstavlja&nbsp; 16,7%&nbsp; od ukupno&nbsp; iskoristivog&nbsp; potencijala&nbsp; obnovljivih&nbsp; izvora&nbsp; energije&nbsp; u&nbsp; Srbiji,&nbsp; dok&nbsp; je&nbsp; prosečno&nbsp; sunčevo zračenje&nbsp; u&nbsp; Srbiji&nbsp; oko&nbsp; 40%&nbsp; vi&scaron;e&nbsp; od&nbsp; evropskog&nbsp; proseka,&nbsp; čineći&nbsp; ga&nbsp; vrlo&nbsp; zanimljivim&nbsp; za&nbsp; primenu&nbsp; u ovom tipu tretmana. U cilju &scaron;to boljeg iskori&scaron;ćenjasunčevog zračenja i unapređenja fotokatalitičkih performansi&nbsp; procesa&nbsp; primenjen&nbsp; je&nbsp; parabolični&nbsp; koncentri&scaron;ući&nbsp; reaktor,&nbsp; koji&nbsp; je&nbsp; za&nbsp; ovu&nbsp; vrstu&nbsp; procesa prvi put upotrebljavan. Proučavano je u kojoj meri je solarna fotokataliza značajan segment tehnike za tretman otpadnih voda tokom degradacije perzistentnih jedinjenja, kao &scaron;to je organska azo boja. Takođe, utvrđen je i potencijal fotolize vodonik-peroksida za obezbojavanjem sintetičkog rastvora date&nbsp; boje.&nbsp; Prva&nbsp; faza&nbsp; imala&nbsp; je&nbsp; za&nbsp; cilj&nbsp; sintezu&nbsp; materijala&nbsp; primenom&nbsp; različitih&nbsp; metoda&nbsp; pripreme&nbsp; i<br />konstrukciju solarnog paraboličnog reaktora, koji će se koristiti u Fenton i foto-Fenton procesima degradacije boje Reactive Red 120. Druga faza je podrazumevala karakterizaciju novosintetisanih materijala i optimizaciju procesa fotokatalize primenom Fenton i foto-Fenton procesa i određivanje postignutih efikasnosti primenjenih procesa. Takođe, vr&scaron;eno je određivanje stepena mineralizacije i identifikacija degradacionih produkata nakon procesa degradacije tekstilne boje Reactive Red 120, kao&nbsp; i&nbsp; primena&nbsp; foto-Fenton&nbsp; procesa&nbsp; na&nbsp; realnom&nbsp; efluentu.&nbsp; Na&nbsp; osnovu&nbsp; dobijenih&nbsp; rezultata&nbsp; tokom primene Fenton procesa i kori&scaron;ćenjem oba tipa katalizatora u periodima niskog i visokog intenziteta zračenja,&nbsp; sa&nbsp; aspekta&nbsp; postizanja&nbsp; visoke&nbsp; efikasnosti&nbsp; obezbojavanja&nbsp; i&nbsp; najmanjeg&nbsp; izluživanja&nbsp; gvožđa,<br />može&nbsp; se&nbsp; zaključiti&nbsp; da&nbsp; je&nbsp; Fenton&nbsp; proces&nbsp; najefikasniji&nbsp; na&nbsp; pH&nbsp; vrednosti&nbsp; 3.&nbsp; AlFeB&nbsp; je&nbsp; pokazao&nbsp; veću reaktivnost čak i pri manje upotrebljenim dozama od0,05 g u odnosu na CuOFeB (0,2 g), kao i mogućnost&nbsp; manje&nbsp; upotrebe&nbsp; vodonik-peroksida&nbsp; od&nbsp; 2,5&nbsp; mM,&nbsp; za&nbsp; postizanje&nbsp; visoke&nbsp; efikasnosti obezbojavanja i postignut visok stepen mineralizacije. Vi&scaron;i intenzitet sunčevog zračenja omogućava odvijanje reakcije obezbojavanja na vi&scaron;im pH vrednostima primenom oba katalizatora tokom fotoFenton&nbsp; procesa.&nbsp; Ovo&nbsp; je&nbsp; posebno&nbsp; izraženo&nbsp; kod&nbsp; CuOFeB&nbsp; tokom&nbsp; letnjeg&nbsp; perioda&nbsp; (pH&nbsp; 7),&nbsp; čak&nbsp; i&nbsp; pri nižim dozama katalizatora. Međutim, najveći udeo u&nbsp; procesu obezbojavanja pri upotrebi CuOFeB katalizatora ima fotoliza vodonik-peroksida (80%). Suprotno ovim rezultatima, pri istim reakcionim uslovima,&nbsp; potrebna&nbsp; je&nbsp; veća&nbsp; količina&nbsp; AlFeB&nbsp; katalizatora&nbsp; (0,1&nbsp; g)&nbsp; i&nbsp; niža&nbsp; pH&nbsp; vrednost&nbsp; reakcije,&nbsp; a efikasnost&nbsp; procesa&nbsp; značajno&nbsp; zavisi&nbsp; od&nbsp; početne&nbsp; koncentracije&nbsp; H₂O₂.&nbsp; Činjenica&nbsp; da&nbsp; se&nbsp; u&nbsp; pripremi katalizatora koristio bentonit kao prirodan, &scaron;irokorasprostranjen i jeftin materijal i solarno zračenje kao obnovljiv i alternativni izvor fotona, gore navedene rezultate bi trebalo uzeti u obzir prilikom analize tro&scaron;kova efikasnosti primenjenog procesa. Takođe, primena unapređenih procesa oksidacije se&nbsp; razmatra&nbsp; kao&nbsp; predlog&nbsp; za&nbsp; najbolju&nbsp; dostupnu&nbsp; tehniku&nbsp; kada&nbsp; je&nbsp; u&nbsp; pitanju&nbsp; tretman&nbsp; otpadne&nbsp; vode tekstilne industrije, dok se kao dodatne nove tehnike uzimaju u obzir foto-oksidacije i ispitivanje mogućnosti&nbsp; njihove&nbsp; primene&nbsp; u&nbsp; preči&scaron;ćavanju&nbsp; otpadne&nbsp; vode&nbsp; u&nbsp; tercijarnom&nbsp; tretmanu&nbsp; na poluindustrijskim sistemima.<br />&nbsp;</p> / <p>The aim of this study was to investigate the decolorization efficiency of Reactive Red 120&nbsp; (RR120) synthetic solution using ferrioxalate (CuOFeB) and Al, Fe-bentonite (AlFeB) catalysts in&nbsp; Fenton&nbsp; and&nbsp; photo-Fenton&nbsp; process.&nbsp; So&nbsp; far,&nbsp; studies&nbsp; of the&nbsp; application&nbsp; of&nbsp; a&nbsp; solar-assisted&nbsp; heterogeneous Fenton process with various Fe loaded catalysts and with ferrioxalate complex have&nbsp; been published, but according to&nbsp;&nbsp; the author&rsquo;s knowledge, their comparison in terms of efficacy of&nbsp; decolorization&nbsp; has&nbsp; not&nbsp; been&nbsp; performed,&nbsp; which&nbsp; was&nbsp; one&nbsp; of&nbsp; the&nbsp; focus&nbsp; of&nbsp; research&nbsp; in&nbsp; this&nbsp; paper.&nbsp; In addition, the potential of solar energy represents&nbsp; 16.7% of the total utilized&nbsp; potential of renewable&nbsp; energy sources in Serbia, while the average solar radiation in&nbsp; Serbia is&nbsp; about 40% higher than the&nbsp; European average, making it very interesting for&nbsp; application in this type of treatment. In order to&nbsp; optimize the use of solar radiation and to improve&nbsp; the photocatalytic performance of the process, parabolic&nbsp; concentrating&nbsp; reactor&nbsp; was&nbsp; used&nbsp; for&nbsp; the&nbsp; first&nbsp; time.&nbsp; As&nbsp; a&nbsp; significant&nbsp; segment&nbsp; of&nbsp; the&nbsp; wastewater&nbsp; treatment&nbsp; technique&nbsp; during&nbsp; the&nbsp; degradation&nbsp; of&nbsp; persistent&nbsp; compounds,&nbsp; such&nbsp; as&nbsp; organic azo dye, solar photocatalysis was studied. Also, the potential of photolysis of hydrogen peroxide for&nbsp; decolorization of the synthetic dye solution was determined. Aim of the first phase of the study was synthesizing&nbsp; materials&nbsp; by&nbsp; using&nbsp; different&nbsp; methods&nbsp; of&nbsp; preparation,&nbsp; and&nbsp; construction&nbsp; of&nbsp; a&nbsp; solar&nbsp; parabolic reactor, which will be used in Fenton andphoto-Fenton dye degradation processes. The second phase involved the characterization of newlysynthesized materials and the optimization of the&nbsp; photocatalytic&nbsp; process&nbsp; by&nbsp; applying&nbsp; Fenton&nbsp; and&nbsp; photo-Fonton&nbsp; processes,&nbsp; as&nbsp; well&nbsp; as&nbsp; the&nbsp; determination&nbsp; of&nbsp; achieved efficiency&nbsp; of&nbsp; the&nbsp; appliedprocesses.&nbsp; Also, the degree&nbsp; of mineralization and the identification of degradation products after applied processes were determined. Application&nbsp; of the photo-Fenton process on a real effluent was conducted as well. Based on the obtained results&nbsp; during&nbsp; Fenton&nbsp; process&nbsp; and&nbsp; using&nbsp; both&nbsp; types&nbsp; of&nbsp; catalysts&nbsp; in&nbsp; periods&nbsp; of&nbsp; low&nbsp; and&nbsp; high&nbsp; intensity&nbsp; of&nbsp; radiation, from the aspect of achieving high efficiency of decolorization and smallest iron leaching,&nbsp; it&nbsp; can&nbsp; be&nbsp; concluded&nbsp; that&nbsp; the&nbsp; Fenton&nbsp; process&nbsp; is&nbsp; most effective&nbsp; at&nbsp; pH&nbsp; 3.&nbsp; AlFeB&nbsp; showed&nbsp; greater&nbsp; reactivity even at less used doses of 0.05&nbsp; g, compared to CuOFeB (0.2 g), and the possibility of using&nbsp; less&nbsp; hydrogen&nbsp; peroxide&nbsp; (2.5&nbsp; mM),&nbsp; achieving&nbsp; high&nbsp; efficiency&nbsp; and&nbsp; a&nbsp; high&nbsp; degree&nbsp; of mineralization. Higher intensity of solar radiationallows the reaction to be carried out at higher pH values when using both catalysts during the photo-Fenton process. This is particularly pronounced largest part in the decolorization process using the CuOFeB catalyst has&nbsp; a photolysis of hydrogen peroxide&nbsp; (80%).&nbsp; Contrary&nbsp; to&nbsp; these&nbsp; results,&nbsp; under&nbsp; the&nbsp; same&nbsp; reaction&nbsp; conditions,&nbsp; a&nbsp; higher&nbsp; doses&nbsp; of AlFeB catalyst (0.1 g) is needed at lower pH value&nbsp; of the reaction, and the process efficiency is significantly dependent on the initial concentration of H ₂O₂. The fact that in the preparation of the catalysts bentonite as a natural, abundant, inexpensive material was used and solar&nbsp; radiation as a renewable and alternative source of photons, the above results should&nbsp; be taken into account in the cost-effectiveness&nbsp; analysis&nbsp; of&nbsp; the&nbsp; applied&nbsp; process. Also,&nbsp; the&nbsp; application&nbsp; of&nbsp; advanced&nbsp; oxidation processes is considered as a proposal&nbsp; for the best available technique when it comes to the treatment of&nbsp; wastewater&nbsp; from&nbsp; the&nbsp; textile&nbsp; industry,&nbsp; while&nbsp; as&nbsp; additional&nbsp; new&nbsp; techniques,&nbsp; photooxidation&nbsp; is considered as a candidate and the possibility of their application in the treatment of wastewater in tertiary treatment on semi-industrial systems.</p>

In der vorliegenden Arbeit wurde die heterogen-katalysierte, partielle Gasphasenhydrierung von Benzol zu Cyclohexen untersucht. Dazu wurden Träger- und Schalenkatalysatoren für Schüttgutreaktoren sowie Mikrostruktur-Reaktoren mit katalytisch aktivierten Wafern hergestellt und eingesetzt. Die Bildung des thermodynamisch und kinetisch nicht begünstigten Zielproduktes Cyclohexen konnte durch den Reaktionsmodifikator Methanol bewirkt werden. Dieser war in der Lage, die Verhältnisse der Geschwindigkeiten der Teilreaktionen sowie der Sorptionsprozesse an der Katalysatoroberfläche so zu beeinflussen, daß Cyclohexen im Abgasstrom der Reaktion nachgewiesen werden konnte. Dabei gelang es außerdem, die Reaktion unter quasi-stationären Bedingungen an unterschiedlichen Katalysatoren reproduzierbar durchzuführen und mit Hilfe eines einfachen Verfahrens die Katalysatoren zu reaktivieren. Der Einfluß des Trägermaterials von Ruthenium-Katalysatoren auf Umsatzgrad, Selektivität sowie das Desaktivierungsverhalten während der Gasphasenhydrierung wurde ermittelt. Darüber hinaus wurde eine Reihe von unpromotierten und promotierten Ru/Al2O3-Trägerkatalysatoren mit Hilfe des Sol-Gel-Verfahrens präpariert und in der Gasphasenhydrierung von Benzol in Gegenwart des Reaktionsmodifikators Methanol untersucht. Dabei konnte gezeigt werden, daß die zusätzliche Promotierung mit Zinkoxid zu einer weiteren Verbesserung der Cyclohexen-Bildung führte. Die Mikrostruktur-Reaktoren für die partielle Gasphasenhydrierung von Benzol wurden zum einen aus mikrostrukturierten Aluminium-Wafern und zum anderen aus mikrostrukturierten Edelstahl-Wafern gebildet. Beide Wafertypen wurden mit unterschiedlichen Methoden katalytisch aktiviert. Die Aluminium-Wafer wurden durch anodische Oxidation und anschließende Imprägnierung aktiviert, für die Aktivierung der Edelstahl-Wafer wurde ein Sol-Gel-Tauchbeschichtungs- Verfahren mit Imprägnierung angewendet. Bei der Untersuchung der partiellen Gasphasenhydrierung von Benzol an den Mikrostruktur-Reaktoren mit den jeweiligen Waferkatalysatoren zeigte sich, daß die Mikrostruktur-Reaktoren mit Aluminium-Waferkatalysatoren bezüglich der Bildung von Cyclohexen besser geeignet waren, als die Mikrostruktur-Reaktoren mit Edelstahl-Waferkatalysatoren. Es wurde gezeigt, daß ein Mikrostruktur-Reaktor in der partiellen Gasphasenhydrierung von Benzol das gleiche Selektivitäts-Umsatz-Verhalten aufweist, wie ein Schüttgutreaktor mit vergleichbarem Schalenkatalysator.

Statische Rottereaktoren sind mit ihrem Festbett das vorherrschende technologische Konzept zur biologischen Behandlung von Restabfall (MBA) und zur Bioabfallkompostierung. Auftretende prozesstechnische Probleme beim Reaktorbetrieb waren die Motivation zur vorliegenden Arbeit. Untersucht wurde das Betriebsverhalten am Beispiel von MBA-Anlagen. Die Bedingungen und Vorgänge wurden im Kontext von Stoffsystem und technischem System unter Anwendung verfahrenstechnischer Methoden analysiert. Für Großanlagen geeignete experimentelle Methoden wurden entwickelt und das Betriebsverhalten im Istzustand und im modifizierten Anlagenzustand beschrieben. Es wurden signifikante Beeinflussungen der Rottebedingungen durch Stoffsystem und Prozessführung unter Einwirkung der Technik deutlich. Die prozessrelevanten Einflussfaktoren sowie deren Ursachen und Wirkungen auf das Betriebsverhalten konnten analysiert und zahlreiche konzeptions- und konstruktionsbedingte Probleme statischer Rottereaktoren identifiziert werden. Als besonders problematisch zeigten sich stochastisch und systematisch auftretende Vorzugsströmungen aufgrund der Heterogenität des Haufwerks und undefinierte Bedingungen zur Belüftung aufgrund schwankender Druckbedingungen im Prozessluftsystem und gegenseitiger Beeinflussungen. Aus den Ergebnissen wurden Maßnahmen für einen verbesserten Betrieb bestehender Anlagen und Lösungen für zukünftige Anlagen abgeleitet / With their fixed bed, static reactors are the predominant technological concept for the biological treatment of residual waste (MBT) and for the composting of bio-waste. Process-based problems in the reactor operation were the motivation for the present work. The operating behavior was examined using the example of MBT plants. The conditions and processes were analyzed in the context of the material system and the technical system using process engineering methods. Experimental methods suitable for real plants were developed and the operating behavior in the current state and in the modified plant state was described. Significant influences on the rotting conditions by the material system and process management under the effect of technology became apparent. The process-relevant influencing factors and their causes and effects on the operating behavior could be analyzed and numerous concept- and construction-conditioned problems of static reactors could be identified. Stochastic and systematic preference flows due to the heterogeneity of the material in the reactor and undefined conditions for ventilation due to fluctuating pressure conditions in the process air system and mutual influences were particularly problematic. Technical measures for improved operating behavior of existing plants and solutions for future plants were derived from the results.

This thesis is focused on medical radioisotopes production ca- pabilities at the LVR-15 research reactor at Řež, near Prague in the Czech Republic. Firstly, a calculation prediction of activities for the chosen target materials is provided as well as the determination of the suitable irradiation time for the experiment. These target materials in the form of activation detectors are then irradiated in the reactor. Their activities are measured by methods of γ-spectrometry and the results are compared with the pre- dictions. This validates those calculation predictions for the use of activity predictions for the process of medical radioisotope production at the LVR- 15 reactor and for the subsequent shipment of these radioisotopes to the hospitals and/or final processors. 1