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Thesis (M. Sc.)--University of Canterbury, 2007. / Typescript (photocopy). Includes bibliographical references (leaves 76-78). Also available via the World Wide Web.

The aim of this thesis is to analyze the heat transfer in steam generator of blocks in the nuclear power plant VVER 440. The steam generator represents the border between the primary and the secondary circuit. The heat is carried from a warm water from reactor to a cold water. The steam arises after the heat transfer and drives the steam turbine. An important quantity which represents the heat transfer is a heat transfer factor. This thesis is divided into theoretical and a practical part. In the theoretical part is mentioned a principle of the steam generator and the theoretical calculation of the heat transfer factor, which comes first of all from the character of the streaming in the steam generator. The practical part brings a comparison of the heat transfer factor calculated from data measured after the start of the third block of EDU in 1986, with the heat transfer factor which comes from the measurement after the power-increase for 105 % of nominal power of the same block in 2009. Further is shown the prediction of the heat transfer factor for next power-increase and the following service is shown too.

Ecologization of agriculture and forestry directly and indirectly influences the environment, water, air, and landscape. Thus, analysis of organic forestry activities, evaluation and forecast are of scientific, ecological and political significance. Weed control and the resulting organic farming and forestry issues have attracted greater attention to the use of physical methods in weed control, because this weed control method is effective and does not leave chemical residues neither in the soil, nor in water. One of the physical methods is thermal weed control method, which contrary to the other weed control methods, leaves only dead biomass, preventing self-sowing of weed seeds in the soil, destroys some of the pests and disinfects the surface layer of soil (Upadhyaya et al, 2007). Meanwhile, as an alternative to seed treatment, various physical methods are also used (Lynikienė, 2006). However, the effect of some of the techniques on seed-born fungi are not explained, optimal exposures of the effects are unidentified (Clear et al., 2002). One of the possibilities to reduce the infestation of seeds by fungi - their thermal destruction. / Žemės ir miškų ūkio ekologizavimas tiesiogiai ir netiesiogiai veikia aplinką, vandenį, orą, landšaftą. Todėl ekologinės veiklos miškų ūkyje analizė, įvertinimas ir prognozė turi mokslinę, ekologinę ir politinę reikšmę (Diepenbrock, 1996). Piktžolių naikinimas ir ekologinės žemės bei miškų ūkių problemos paskatino atkreipti dėmesį į fizikinių metodų naudojimo piktžolių kontrolei svarbą, nes šis piktžolių naikinimo metodas yra efektyvus, nepaliekantis cheminių medžiagų likučių nei dirvožemyje, nei vandenyje. Vienas iš fizikinių metodų ir yra terminis piktžolių naikinimo būdas, kuris, skirtingai nuo kitų piktžolių kontrolės būdų, palieka tik negyvą jų biomasę, neleisdamas piktžolių sėkloms pasisėti dirvoje, sunaikina kai kuriuos kenkėjus ir dezinfekuoja paviršinį dirvožemio sluoksnį (Upadhyaya, 2012). Kaip alternatyva sėkloms beicuoti taip pat naudojami įvairūs fizikiniai metodai (Lynikienė, 2006). Kai kurių metodų poveikis sėklomis plintantiems mikromicetams nenustatytas, nenustatytos ir šių poveikių optimalios ekspozicijos (Clear et al., 2002). Viena iš galimybių sumažinti sėklų užterštumą mikromicetais – jų naikinimas termiškai.

Magistriniame darbe tiriama terminė piktžolių kontrolė vandens garu, kuri yra viena iš aplinką tausojančių technologijų pasėlių piktžolėtumui mažinti. Iki šiol buvo tirtas vandens garo poveikis augalui, atlikti kai kurie temperatūros sklaidos termiškai paveiktame dirvožemio sluoksnyje tyrimai, tačiau poveikis dirvožemio ekosistemai ir jo kokybei nebuvo tirtas. / This Master's thesis investigated thermal weed control by water steam which is green and efficient technology for crop protection. Until now studies of the water steam effect on plants, also some measurements of the temperature spread in soil were performed, however impact on soil ecosystem and its quality has not been studied.

The aim of this diploma thesis is to describe the gasification of biomass with a mixture of oxygen and water vapor. The theoretical part is focused on the gasification process, gasification reactors and the quality of the resulting gas. In the experimental part we look for the ideal ratio of oxygen to water vapor, which are used as gasification media. Subsequent measurements are carried out on the fluidized bed reactor, the results of which are further processed and evaluated.

The aim of the project is to design a steam generator in which the sodium flows pipeline hand, and on the other hand, water flow and water vapor (H2O). The main idea of this thesis is to propose such a steam generator, to avoid or eliminate the possibility of adverse reactions of sodium with water and, if this phenomenon occurs, thus minimizing the damage caused by this reaction. The work contains information on the implementation of steam, steam option, the necessary calculations for the design and construction and evaluation.

Made available in DSpace on 2016-06-02T19:56:52Z (GMT). No. of bitstreams: 1 5331.pdf: 11740082 bytes, checksum: e8f5288e8c937187089b53d5c0ebd1c9 (MD5) Previous issue date: 2013-04-26 / Financiadora de Estudos e Projetos / The combustion of petroleum fuels produces large emissions of NOX, SOX and other strong atmospheric pollutants. The abatement of NOX can be achieved by the nonselective catalytic reduction of NO with CO, for that, supported noble metals have been the most commonly used, with high cost as disadvantage. Transition metal oxides show good activity for this reaction, however, they have poor performance in the presence of SO2, O2 and water steam. Thus, this study aimed to prepare, characterize and evaluate catalysts based on CuO, Fe2O3 and CuO-Fe2O3 supported on TiO2, ZrO2 and their mixtures, in the reduction of NO to N2 with CO in the presence or absence of water steam. XRD data, N2 adsorption and H2-TPR showed that mixed oxides and their catalysts, prepared by sol-gel in-situ, presented specific surface areas between 30 to 60 m2/g, with Cu or Fe species highly distributed, having the last greater interaction with titanium. Rietveld refinement showed preferential formation of zirconium titanate, then showing a close interaction of these species in the mixed supports. All catalysts were highly active in the reduction of NO to N2. At temperatures below 500 °C a CuO catalysts were more active and selective for the formation of N2 than Fe2O3, with the formation of N2O being favored with the increase of zirconium in the support. At 600 °C, the high conversion of NO to N2 on CuO was not influenced by the content of TiO2 in the support. Also at 600 °C, an increasing in the content of titanium in the Fe2O3 catalysts resulted in a significant drop in the conversion of NO to N2. The presence of water steam during the reduction of NO with CO at 600 °C caused a significant decrease in the conversion of NO to N2 and CO to CO2 on the CuO catalyst on the support with higher titanium content. The water steam completely eliminates the activity for the reduction of NO to N2 on Fe2O3 catalysts, but keeping a high conversion of CO to CO2. The CuO and CuO-Fe2O3 catalysts on zirconium-rich supports showed high potential for the abatement of NOX in the presence of water steam at temperatures above 500 ºC. / A combustão de derivados do petróleo gera grandes emissões de NOX, SOX e outros fortes poluentes da atmosfera. O abatimento de NOX pode ser realizado por meio da redução catalítica não seletiva com CO, onde os metais nobres suportados têm sido os mais empregados, com a desvantagem de seu elevado custo. Óxidos de metais de transição apresentam boa atividade nessa reação, no entanto, têm baixo desempenho na presença de SO2, O2 e vapor de água. Assim, este trabalho teve como objetivo preparar, caracterizar e avaliar catalisadores a base de CuO, Fe2O3 e CuO-Fe2O3 suportados em TiO2, ZrO2 ou suas misturas, na redução de NO a N2 com CO na presença ou ausência de vapor de água. Dados de DRX, adsorção de N2 e RTP-H2 mostraram que os suportes mistos e seus catalisadores, que foram preparados via síntese sol-gel in-situ, apresentaram áreas superficiais específicas entre 30 e 60 m2/g, com as espécies de Cu ou Fe altamente distribuídas, tendo essas últimas maior interação com a titânia. Refinamento de Rietveld mostrou formação preferencial de titanato de zircônia, evidenciando a estreita interação dessas espécies nos suportes mistos. Todos os catalisadores foram altamente ativos na redução de NO a N2. Em temperaturas inferiores 500 ºC os catalisadores de CuO foram mais ativos e seletivos à formação de N2 que o Fe2O3, com a formação de N2O sendo favorecida com o aumento de zircônia no suporte. A 600 ºC, a alta conversão de NO a N2 sobre CuO não foi influenciada pelo conteúdo de TiO2 no suporte. Nessa temperatura, o aumento do teor de titânia provocou nos catalisadores de Fe2O3 uma queda significativa na conversão de NO a N2. A presença de vapor de água durante a redução de NO com CO a 600 ºC provocou sobre CuO queda significativa da conversão de NO a N2 e de CO a CO2 sobre o suporte com maior conteúdo de titânia. Nos catalisadores de Fe2O3 puro, o vapor de água anulou completamente a atividade para a redução de NO a N2, mas manteve-se a conversão de CO a CO2. Os catalisadores de CuO e CuO-Fe2O3 sobre suporte contendo alto teor de zircônia apresentaram alto potencial para o abatimento de NOx na presença de vapor de água em temperaturas superiores a 500 ºC.

This diploma thesis describes a JSD600 unit intended for mathematical processing, measuring and data recording. The JSD600 unit is highly intended for industrial measuring of water steam energy delivery.First part of the work focuses on basics of the JSD600 unit detailing and describing main structures and principles for relevant data storing.Next part summarizes some basic facts and knowledge from the area of industrial liquid flow, energy measuring and describes water steam states. All these points within this range are needed for dilemma understanding.Last task deals with complete list of communication datagrams, which have been used for communication with JSD600 unit, including a main packet of structure descriptions.The second part of this dissertation brings the unit setup application description including some implementation details of the most interesting parts.