This thesis presents how a solution to fetch and stream a video feed from the astrovisualization software OpenSpace to a web page can be designed. The streaming protocol that was used was WebRTC. Three different methods for fetching data and creating a video feed were investigated: WebRTC, Spout, and GStreamer. Through user tests, the GStreamer method was determined to be the best option for the streaming solution. / <p>Examensarbetet är utfört vid Institutionen för teknik och naturvetenskap (ITN) vid Tekniska fakulteten, Linköpings universitet</p>

During translation, the transfer RNAs (tRNAs) play the crucial role of adaptors between the messenger RNA and the amino acids. The tRNAs are first transcribed as pre-tRNAs which are then maturated. During this maturation, several nucleosides are modified by tRNA modification enzymes. These modifications are important for the functions of the tRNAs and for their correct folding. Many of the modifications are methylations of the bases or the ribose. Four families of tRNA methyltransferases are known, among which the SPOUT superfamily. Proteins of this superfamily are characterised by a C-terminal topological knot where the methyl donor is bound. With the exception of the monomeric Trm10, all known SPOUT proteins are dimeric and have an active site composed of residues of both protomers. Interestingly, depending on the organism, the same modification can be catalysed by completely unrelated enzymes. On the other hand, homologous enzymes can have different specificities or/and activities. These differences are well illustrated for the TrmJ and Trm10 enzymes.<p>In the first part of this work we have identified the TrmJ enzyme of Sulfolobus acidocaldarius (the model organism of hyperthermophilic Crenarchaeota) which 2’-O-methylates the nucleoside at position 32 of tRNAs. This protein belongs to the SPOUT superfamily and is homologous to TrmJ of the bacterium Escherichia coli. A comparative study shows that the two enzymes have different specificities for the nature of the nucleoside at position 32 as well as for their tRNA substrates. To try to understand these shifts of specificity at a molecular level we solved the crystal structure of the SPOUT domains of the two TrmJ proteins.<p>In the second part of this work, we have determined the crystal structure of the Trm10 protein of S. acidocaldarius. This is the first structure of a 1-methyladenosine (m1A) specific Trm10 and also the first structure of a full length Trm10 protein. The Trm10 protein of S. acidocaldarius is distantly related to its yeast homologues which are 1-methylguanosine (m1G) specific. To understand the difference of activity between the Trm10 enzymes, we compared the yeast and the S. acidocaldarius Trm10 structures. Remarkably several Trm10 proteins (such as Trm10 of Thermococcus kodakaraensis) are even able to form both m1A and m1G. To understand the capacity of the T. kodakaraensis protein to methylate A and G, a mutational study was initiated./Lors de la traduction, les ARN de transfert (ARNt) jouent le rôle crucial d’adaptateurs entre l’ARN messager et les acides aminés. Les ARNt sont transcrits sous forme de pré-ARNt qui doivent être maturés. Lors de cette maturation, plusieurs nucléosides sont modifiés. Un grand nombre de ces modifications sont des méthylations des bases ou du ribose. Quatre familles d’ARNt méthyltransferases sont actuellement connues, dont la superfamille des SPOUT. Les membres de cette superfamille sont caractérisés par un nœud dans la chaîne polypeptidique du côté C-terminal. C’est au niveau de ce nœud que se lie la S-adénosylméthionine qui est le donneur de groupement méthyle. A l’exception de Trm10 qui est monomérique, toutes les protéines SPOUT connues sont dimériques et leur site actif est formé de résidus provenant des deux protomères. Selon l’espèce, une même modification peut être formée à la même position dans la molécule d’ARNt par des enzymes qui appartiennent à des familles différentes. A l’opposé, des enzymes homologues peuvent présenter des spécificités ou des activités différentes.<p>Au cours de ce travail, nous avons identifié l’enzyme TrmJ de Sulfolobus acidocaldarius (l’organisme modèle des Crénarchées hyperthermophiles) qui méthyle le ribose du nucléoside en position 32 des ARNt. Cette protéine est un homologue de l’enzyme TrmJ de la bactérie Escherichia coli. L’étude comparative que nous avons réalisée a révélé que ces deux enzymes présentent une différence de spécificité pour la nature du nucléoside en position 32 ainsi que pour les ARNt substrats. Afin de comprendre ces différences de spécificité au niveau moléculaire, les structures des domaines SPOUT des deux TrmJ ont été déterminées et comparées.<p>En parallèle, nous avons résolu la structure cristalline de la protéine Trm10 de S. acidocaldarius. C’est la première structure disponible d’un enzyme Trm10 formant de la 1-méthyladénosine (m1A). C’est aussi la première structure complète d’une protéine Trm10. Les enzymes homologues des levures Saccharomyces cerevisiae et Schizosaccharomyces pombe qui n’ont que peu d’identité de séquence avec l’enzyme de S. acidocaldarius, forment de la 1-méthylguanosine (m1G). Dans le but de comprendre comment ces enzymes homologues peuvent présenter des activités différentes, leurs structures ont été comparées. De manière surprenante, certains homologues de Trm10 (comme l’enzyme de l’Euryarchée Thermococcus kodakaraensis) sont capables de former du m1A et du m1G. Afin de mieux comprendre comment ces protéines sont capables de méthyler deux types de bases, nous avons initié l’étude de l’enzyme Trm10 de T. kodakaraensis par mutagenèse dirigée.<p><p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

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Made available in DSpace on 2015-03-26T14:01:03Z (GMT). No. of bitstreams: 1 texto completo.pdf: 4064077 bytes, checksum: 9b21ed6ac17078998aca806bb631cda3 (MD5) Previous issue date: 2010-06-14 / Acidentes com Bicas de Smelt são reportados pelo Black Liquor Recovery Boiler Advisory Committee, BLRBAC, e constituem uma preocupação real de segurança sob o ponto de vista operacional. Tipicamente o smelt escorre através de bicas refrigeradas a água da fornalha para o tanque dissolvedor e uma falha pode levar a explosões pelo contato água-smelt. Este trabalho estuda um caso real onde condições severas de corrosão culminaram com a falha em serviço de uma de seis bicas em uma caldeira de recuperação na CENIBRA. A falha resultou em grande volume de água de resfriamento entrando na caldeira e em contato com smelt ao redor da abertura da bica, mas felizmente não ocorreram explosões água-smelt. Uma elaborada investigação foi conduzida para se determinar as causas da falha da bica. Conclui-se que a falha foi causada por fluxo insuficiente de água de resfriamento para a bica de smelt, que, por sua vez, foi causada por uma seqüência de eventos que ocorreram após uma falha geral no sistema de geração de energia elétrica da fábrica. O estudo do evento levou ao desenvolvimento e implantação de procedimentos operacionais e de manutenção que tem por objetivo assegurar fluxo de água de resfriamento adequado para as bicas de smelt para prevenção de falhas recorrentes. / Smelt Spout accidents are reported by Black Liquor Recovery Boiler Advisory Committee, BLRBAC, and constitute a real safety concern from the operational point of view. Typically smelt flows through water cooled spouts from furnace to the smelt dissolving tank and a failure can lead to smelt-water contact explosions. This work studies a real case where severe corrosion led to an in-service failure of one of the six spouts on a recovery boiler at Cenibra. The failure resulted in a large amount of cooling water entering the boiler and contacting smelt around the spout opening, but fortunately no smelt-water explosion occurred. An extensive investigation was conducted to determine the causes of the spout failure. It was concluded that the failure was caused by insufficient cooling water flow to the smelt spout, which, in turn, was caused by a sequence of events that occurred after a general black out of an electrical energy system at the mill. The experience has led to the development and placement of operating and maintenance procedures that ensure adequate cooling water flow to smelt spouts to prevent future failures.

Submitted by Johnny Rodrigues (johnnyrodrigues@ufcg.edu.br) on 2018-10-17T16:51:04Z No. of bitstreams: 1 VIMÁRIO SIMÕES SILVA - TESE PPGEP 2004..pdf: 7946663 bytes, checksum: d4d441a16d5722370a6af66bb77ae188 (MD5) / Made available in DSpace on 2018-10-17T16:51:04Z (GMT). No. of bitstreams: 1 VIMÁRIO SIMÕES SILVA - TESE PPGEP 2004..pdf: 7946663 bytes, checksum: d4d441a16d5722370a6af66bb77ae188 (MD5) Previous issue date: 2004-08-31 / Os microrganismos, além de sua importância industrial na obtenção por via biotecnológica de diversos produtos, podem ser utilizados diretamente como alimento para humanos e animais. Neste contexto, vem crescendo o interesse pelo aproveitamento de fontes proteicas não tradicionais, na formulação de ração animal. A utilização de leveduras, tem por meta suprir a carência de proteínas e vitaminas BI. A operação de secagem é importante porque prepara o produto com as características necessárias para atender as exigências de mercado e dentro deste contexto, o leito de jorro e leito fluidizado podem ser utilizados como mais uma opção dentro dos diversos tipos de secadores ora empregados nesta operação. A matéria prima utilizada neste trabalho foi à levedura do gênero Saccharomyces cerevisiae prensada do tipo comercial (fermento biológico fresco da marca Fleischmann"), com umidade média de 70% em base úmida, de cor creme, e granulometria média de 0,991 mm. Os experimentos de secagem de levedura foram realizados em leito de inertes constituído de partículas de poliestireno de 3,26 mm em coluna de 10,3 cm de diâmetro e 25,3 cm de altura. Inicialmente foram levantados dados de equilíbrio higroscópico da levedura a 25, 30, 40 e 49 °C e as isotermas de dessorção obtidas foram ajustadas pelos modelos de GAB e BET Numa segunda etapa, foi estudada a fluidodinâmica do leito de jorro e leito fluidizado para analisar o efeito da presença de leveduras sobre o comportamento do leito de inertes e definir as condições mínimas de operação de modo a estabelecer a matriz de planejamento fatorial. Com o objetivo de analisar e comparar o desempenho dos leitos fluidodinamicamente ativos foi estudada a secagem em leito de jorro e leito fluidizado. Para isto, foi seguido um planejamento fatorial tendo como variáveis de entrada a velocidade do ar e a quantidade de leveduras alimentada, e, como respostas, o rendimento, retenção, perdas, umidade do produto e teor de proteínas. A temperatura foi fixada entre 38 e 44 °C. para todos os experimentos. As taxas instantâneas de evaporação de água apresentaram flutuações na maioria dos ensaios, tanto em leito de jorro como em leito fluidizado, as eficiências energéticas de secagem foram relativamente baixas nos dois processos, em torno de 5 a 50%. A cinética de produção de pó mostrou comportamento crescente e praticamente linear em todos os experimentos. Foi obtido nos ensaios em leito de jorro, um conteúdo de umidade no produto entre 11,65 a 31,34%, em base úmida, e teor proteínas entre 50,09 e 52,68%. Para o leito fluidizado em 7,98 a 48,72% de umidade e 40,6 a 49,7% de proteínas Diante do exposto, o secador de leito de jorro apresentou melhor desempenho, visto que, na qualidade do produto, a umidade e teor de proteínas apresentaram melhores resultados, e um maior rendimento e menor retenção de pó. Comparado com outros secadores, apresentou desempenho maior em termos de proteínas e performance, sendo recomendado estudar o processamento com temperaturas maiores de modo a reduzir o teor de umidade do produto. / Microorganisms, aside from their industrial importance in obtaining several products by biotechnology, can be used directly as food for humans and animals. In this context, an interest in non-conventional sources of protein for animal feed has been growing. The use of yeasts has the aim of supplying the proteins and vitamin B1 requirement. The drying operation is important because it prepares the product with the characteristics necessary for attending to the market demands and in this context the spouted bed and the fluidized bed can be used as one more option in the various types of dryers used in this operation. The raw material used in this work was pressed Saccharomyces cerevisiae commercial type yeast (fresh biological Fleischmann yeast), with an average moisture of 70% in a wet base, cream-colored, and an average size of 0.991 mm. The yeast drying experiments were performed in inert beds constituted by polystyrene particles of 3.26 mm in a column of 10.3 cm of diameter and 25.3 cm of height. The yeast was fed at the top of the column in an intermittent regime. Initially data of hygroscopic equilibrium of the yeast were studied at 25. 30, 40 and 49 °C and the obtained desorption isotherms were adjusted by the GAB and BET models. In a second stage, the fluid dynamics of the spouted bed and the fluidized bed was studied to analyze the effect of the presence of yeast on the behavior of the inert particles bed and to define the minimal operating conditions so that the matrix of factorial design was established. With the objective of analyzing and comparing the performance of the dynamically active beds, the drying of yeast in the spouted and the fluidized bed was studied. For this, a factorial experimental design was followed. The input variables were the velocity of the air and the quantity of yeast fed and as response variables the product yield, retention, loses, moisture and protein content of the dried yeast. The temperature was fixed between 38 and 44 °C for all the experiments. The instant water evaporation rate presented fluctuations in most of the experiments, both in the spouted bed and in the fluidized bed. The drying energy efficiency was relatively low in both processes, in turn of 5 and 50 %. The powder production kinetics showed an increasing and practically linear behavior in all the experiments. The moisture content of the product varied between 11.65 and 31.34% in a wet base and a protein content between 50.09 and 52.68% was obtained in the spouted bed tests. For the fluidized bed a 7.98 to 48.72% moisture and 40.6 to 49.7% proteins were obtained. The spouted bed dryer presented a better performance, inasmuch as, in the quality of the product, the moisture and the protein content presented best results and a greater yield and less retention of powder. Compared to other dryers, it presented a better operation in terms of protein and performance. It is recommended to study the process in a higher temperature interval so as to reduce the moisture content of the product.