Tobacco rattle virus (TRV) is a bipartite plant virus that infects potato tubers to produce the spraing or corky ring spot (CRS) disease of potato. TRV is primarily a soil-borne pathogen that is vectored by trichodorid nematodes. Spraing is characterized by the production of brown arcs and flecks in the tuber flesh or circular rings on its external surface. Spraing has been described as a hypersensitive response (HR). However, the genetic and biochemical nature of spraing had not been previously investigated experimentally. I have conducted studies to reveal the gene expression and the biochemical basis for spraing formation. Microarray analysis of RNA extracted from tuber-tissue showing spraing symptoms, revealed up-regulation of several defence related genes. Quantitative RT-PCR (qRT-PCR) of some of the differentially-expressed potato defence related genes was done for verification of the microarray data. Biochemical tests for cell death response reactions and staining for HR-related compounds or production of reactive oxygen species (ROS) also revealed the operation of HR-related processes in the spraing-affected tuber. Uneven distribution of the TRV RNA-1 in a spraing-symptomatic tuber also supports the notion that it’s a virus-induced HR-response. RNA-2 of TRV besides coding for the CP also carries the non-structural genes, 2b and 2c genes that are responsible for the nematode transmission of TRV. Fifteen different TRV recombinant isolates were prepared and the influence of the RNA-2 specific genes, encoded by a range of TRV-isolates, in causing infection among different cultivars of potato was also evaluated. Investigations were conducted to identify TRV-susceptible genotypes in which virus could move systemically and accumulate to a sufficient level to be useful for TRV-infection and VIGS-related studies for functional analysis of potato genes.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / A cajucultura, como atividade de importÃncia econÃmica para o Nordeste brasileiro, vem passando por um perÃodo de decrÃscimo de produtividade, muito por causa do regime extrativista empregado no seu cultivo e pela falta de um mÃnimo de tÃcnicas de manejo de produÃÃo, dentre eles o controle de pragas. Muitos sÃo os fatores que influenciam na eficiÃncia de uma aplicaÃÃo de defensivos, porem grande parte dos produtores dÃo mais importÃncia ao produto aplicado que a forma como ele à aplicado. Definir o volume adequado de calda a ser aplicado na copa de culturas arbÃreas à uma tarefa difÃcil, devido a variabilidade existente entre os cultivos. O conceito de TRV (Tree Row Volume) surgiu como uma forma de adequar a quantidade de calda a ser aplicada em funÃÃo do volume da copa da cultura. Objetivou-se com este trabalho avaliar a deposiÃÃo de calda e corante na folha do cajueiro e as perdas de corante e calda para o solo em aplicaÃÃes em oito taxas de aplicaÃÃo, sendo quatro dessas taxas aplicadas com um turboatomizador, trÃs com um equipamento costal motorizado e uma com equipamento costal manual. O experimento foi conduzindo em uma Ãrea de cajueiro anÃo precoce localizada no municÃpio de PacajÃs-CE. Para as aplicaÃÃes, as taxas dos equipamentos foram regulados, onde para o turboatomizador foram realizadas regulagens na orientaÃÃo do fluxo de ar, taxa de aplicaÃÃo e do perfil de distribuiÃÃo vertical da calda, para os equipamentos costal manual e costal motorizado foram feitas a regulagem das taxas de aplicaÃÃo. Os testes de deposiÃÃo de calda e corante na copa do cajueiro foram conduzidos no delineamento experimental de faixas, onde os tratamentos principais foram oito taxas de aplicaÃÃo, sendo quatro destas aplicadas com o turboatomizador (100%, 85%, 70% e 50% da taxa de aplicaÃÃo de referencia), trÃs pelo pulverizador costal motorizado (nÃvel 6, entre o nÃvel 3 e 4 e o nÃvel 1 do controlador de vazÃo) e uma com o pulverizador costal manual, os tratamentos secundÃrios foram os seis pontos de coletas na copa do cajueiro. Os testes de perdas de corante e de calda para o solo foram conduzidos no delineamento de blocos, onde os tratamentos foram as oito taxas de aplicaÃÃo utilizados nos testes de deposiÃÃo na copa. A deposiÃÃo de calda na copa da cultura se deu de forma crescente a medida que se aumentou a taxa de aplicaÃÃo, apresentando uma maior concentraÃÃo na parte lateral da copa da cultura. Maiores valores de deposito de corante foram encontrados nos tratamentos com o pulverizador costal motorizado com regulador de vazÃo no nÃvel 6 e entre os nÃveis 3 e 4, nas aplicaÃÃes com o turboatomizador uma maior deposiÃÃo de corante foi encontrada nos tratamentos com 70% e 55% da taxa de aplicaÃÃo de referÃncia. As aplicaÃÃes com o turboatomizador apresentaram maior uniformidade de distribuiÃÃo de corante nos pontos de coleta em relaÃÃo aos equipamentos costal motorizado e costal manual. Maiores perdas de calda foram encontradas a medida que se aumentou a taxa de aplicaÃÃo, com exceÃÃo da aplicaÃÃo com o equipamento costal manual. Maiores perdas da corante foram encontradas nas aplicaÃÃes com o equipamento costal manual, seguido das aplicaÃÃes com o turboatomizador e com o pulverizador costal motorizado. As aplicaÃÃes com equipamento costal motorizado com regulador de vazÃo no nÃvel 6 e entre os nÃveis 3 e 4 se mostraram mais eficiente em depositar calda na cultura do cajueiro, para as aplicaÃÃes com o turboatomizador a taxa da aplicaÃÃo com 55% da taxa da aplicaÃÃo de referÃncia se mostrou mais eficiente em depositar corante e com menores perdas. Pode-se concluir que a deposiÃÃo na folha e perda para o solo de calda à maior quanto maior a taxa, porÃm a deposiÃÃo de corante na folha à maior no equipamento costal motorizado e a maior perda de corante para o solo se dà na aplicaÃÃo com o equipamento costal manual. / The cashew cultivation as an activity of economic importance for the Brazilian Northeast, has been going for a period of decline in productivity, largely because of the extractive scheme employed in its cultivation and the lack of minimal technical management of production factors, among them pest control. There are many factors that influence the effectiveness of a pesticide application, however much the producers give more importance to the applied product that the form how it is applied. Set the appropriate water volume to be applied in the canopy of tree crops is a difficult task due to the variability between crops. The concept of TRV has emerged as a way to adjust the amount of syrup to be applied depending on the volume of the canopy. The objective of this study was to evaluate the deposition of dye and syrup in the cashew leaf and losses of dye and syrup for ground applications in eight application rates, with four of those rates applied air carrier sprayer with a three with a motorized knapsack equipment and a manual knapsack with equipment. The experiment was driving in an area of dwarf cashew localized in Pacajus - CE. The adjustment of application equipment used at work for the air carrier sprayer was made adjustments were made in the direction of air flow, application rate and the vertical distribution profile of the syrup to the knapsack and motorized knapsack equipment of the adjustment were made application rates. Tests of spray deposition and dye in cup cashew were conducted in experimental design tracks in a split plot design where the main treatments were eight application rates, four of which applied to the air carrier sprayer (100%, 85%, 70% and 50% of the application rate of reference), three by motorized knapsack sprayer (level 6, between level 3 and 4 and level 1 flow controller) and one with manual knapsack, secondary treatments were the six points collections in the cup cashew. Tests for loss of dye and syrup to soil were conducted in the experimental design of tracks, where treatments were eight application rates used in the tests deposition in the cup. The spray deposition on the cup occurred incrementally measure that increased the rate of application, with a higher concentration at the side of the cup. Higher values of deposit of dye were found in treatments with motorized knapsack sprayer with flow regulator at level 6 and between levels 3 and 4, the air carrier sprayer applications with greater deposition of dye was found in the treatments with 70 % and 55 % the rate of application of reference. The applications with the air carrier sprayer showed greater uniformity of dye at collection points in relation to motorized and manual equipment costal rib. Greater losses of the syrup as it increased the rate of application, with the exception of the application with knapsack equipment were found. Greater losses of dye were found in applications with manual knapsack equipment, followed by the air carrier sprayer applications and motorized knapsack sprayer. Applications with motorized knapsack equipment with flow regulator at level 6 and between levels 3 and 4 were more efficient in depositing the crop cashew dye, for applications with the air carrier sprayer application rate with 55 % of the rate of application of reference is more efficient in depositing dye and with smaller losses. It can be concluded that the deposition in the leaf and loss to the soil is greater the higher the rate, but the deposition of dye on the leaf is higher in motorized knapsack sprayer and more loss of dye to the ground occurs in the application equipment knapsack.tr

La Tripanosomiasis americana es el problema sanitario más relevante de la Argentina, afectando cerca de 1,6 millones de personas. La Organización Mundial de la Salud considera a la enfermedad de Chagas como uno de los mayores flagelos de América Latina: unas 18 millones de personas sufren sus consecuencias y 120 millones están en riesgo de infección. Si bien esta enfermedad se distribuye principalmente en América Latina, en las últimas décadas se ha observado con mayor frecuencia en los Estados Unidos, Canadá, muchos países europeos y algunos del Pacífico Occidental. Hasta hoy, el control de esta enfermedad, se basa exclusivamente en insecticidas que acarrean múltiples problemas en cuanto a su incorrecta aplicación y baja selectividad, debido a que eliminan tanto enemigos naturales de los triatominos como otras especies benéficas para el hombre, produciendo un gran deterioro en el medio ambiente, provocando todo esto que los insectos sean cada vez más resistentes a los insecticidas aplicados. La introducción o el incremento de enemigos naturales en poblaciones naturales de las principales especies transmisoras de Chagas, puede lograr con el tiempo la reducción del número de vectores a niveles que aseguren la interrupción de la transmisión del parásito en la población susceptible. Cabe destacar que los aspectos negativos en las campañas de rociado y la perspectiva que esas dificultades se agraven, ha motivado a que la búsqueda de nuevos métodos de control de triatominos de domicilio y peridomicilio haya sido identificada como un área prioritaria de investigación por la Organización Mundial de la Salud. El Triatoma virus (TrV) es el único virus entomopatógeno identificado en triatominos hasta el momento. Existen observaciones que sustentarían el uso de TrV como control biológico. Muscio en 1997, registró porcentajes superiores a 90% de mortalidad en el laboratorio en estados ninfales de T. infestans infectados con TrV. Además, Rozas-Dennis y Cazzaniga en el 2000, observaron que la infección con TrV reduce la longevidad y la fecundidad de las hembras adultas, y que las ninfas infectadas muestran parálisis en las patas y dificultad para desprenderse de la exuvia. De acuerdo al Comité Internacional de Taxonomía Viral (ICTV), TrV pertenece a la familia Dicistroviridae cuya especie tipo es el virus de la parálisis del grillo, con un único género: Cripavirus. Es un virus ARN de hebra simple y sentido positivo, con una longitud de 9.010 bases y una masa molecular teórica de 2.886,4 KDa. La composición de los viriones de TrV es 35% de ARN y 65% de proteínas. El genoma posee dos marcos abiertos de lectura denominados ORF1 y ORF2 que codifican las proteínas no estructurales y de la cápside respectivamente; separados por una región intergénica (IGR). De acuerdo a los estudios realizados hasta el momento, TrV puede transmitirse principalmente por vía horizontal, mediante la ruta fecal-oral, como así también por una vía vertical (transovárica). Su distribución en la naturaleza se restringe solamente a T. infestans y T. sordida. Hasta el momento no se conocen estudios inherentes a la búsqueda de TrV en Latinoamérica: al presente solo se ha encontrado en Argentina. El objetivo central de este trabajo fue, por un lado estudiar la diversidad de TrV en triatominos de nuestro país; y obtener un sistema para la replicación de TrV in vitro. Así, se analizaron triatominos de 10 provincias argentinas desde el 2008 hasta el 2011, resultando un total de 1632 ejemplares pertenecientes a 10 especies de domicilio, peridomicilio y ambiente silvestre: T. infestans, T. guasayana, T. delpontei, T. breyeri, T. eraturysiforme, T. sordida, T. platensis, T. garciabesi, Panstrongylus guentheri y Psammolestes coreodes. Las especies anteriormente mencionadas fueron capturadas en viajes de campaña, obtenidas del material conservado en la colección de nuestro laboratorio o enviadas de otros centros de referencia. A todos los insectos se les extrajo la materia fecal para luego extraerle ARN y finalmente analizarlas mediante RT-PCR. Los resultados positivos resultantes de la RT-PCR fueron 29. Estos productos resultantes se purificaron, cuantificaron y se enviaron a secuenciar. El análisis de las muestras secuenciadas no mostraron variabilidad genómica significativa. Esto se vio reflejado tanto a nivel específico, como de hábitat y distribución geográfica de los triatominos. Contar con líneas o cultivos celulares sensibles a la infección con TrV podría traer grandes ventajas. Permitir aislar, caracterizar y estudiar en profundidad la biología del virus nos permitiría obtener masa viral, siendo una herramienta fundamental para su posible uso como agente de control biológico. Si bien, no se conocen líneas celulares susceptibles a TrV, se intentó su replicación en líneas de dípteros y lepidópteros. Se desconoce además, si el virus producirá efecto citopático visible en las células. Con respecto a este otro gran objetivo general, se intentó la replicación de TrV en cultivos celulares. Por un lado, en líneas celulares de insecto, por medio de distintos métodos: transfección, electroporación, inoculación con tripsina y con virus purificado. Por otro lado se intentó obtener cultivo primario de vinchucas sanas. Para esto se utilizaron triatominos de la colonia de nuestro laboratorio. Los sustratos para la realización del cultivo primario fueron embriones y adultos (con y sin tripsina y explantos); además se inocularon huevos embrionados. Para todos los métodos y ensayos descriptos anteriormente, se utilizaron técnicas de SDS-PAGE, Western Blot (WB), Inmunofluorescencia indirecta (IFI) o bien RT-PCR para confirmar la presencia del TrV en las células. Para evaluar el líquido alantoideo se utilizó la técnica de Hemaglutinación (HA). No fue posible la replicación in vitro de TrV en líneas celulares de dípteros (C6/36) y lepidópteros (SF9, SF21, HighFive). Tampoco fue posible obtener un clon celular partiendo de tejidos adultos o embrionarios de vinchucas sanas. En cuanto a la presencia de virus en líquido alantoideo por HA, en ningún caso se obtuvo resultado positivo, ni tampoco utilizando sobrenadantes supuestamente infectados. Sin embargo el virus TrV purificado utilizado como control, aglutinó los glóbulos rojos de pollo. En las pruebas complementarias de Microscopia electrónica, SDS-PAGE, WB, IFI, RT-PCR tampoco obtuvimos resultados satisfactorios. Este trabajo de tesis, representa uno de los estudios más amplios realizado hasta el presente en TrV de triatominos en Argentina. El registro de este virus es de alta importancia, debido a que de las tres vías posibles de contagio de la enfermedad de Chagas, la vectorial es la predominante en el área endémica, siendo imprescindible profundizar aún más en el conocimiento de los insectos huéspedes para optimizar su control. Los resultados de esta labor, amplían considerablemente la información existente sobre este virus en Argentina, siendo de suma importancia además para el resto de los países afectados por la enfermedad. Si bien no fue posible la replicación del virus in vitro, nada se conocía al respecto sobre TrV. Es por ello que se intentará su replicación en líneas celulares de hemípteros, donde se han citado resultados exitosos en virus muy cercanos filogenéticamente. Se esbozan datos novedosos sobre la distribución geográfica y de ambiente; hospedero y variabilidad genómica de las especies analizadas. Si bien no ha sido uno de los objetivos de este trabajo de tesis, el desarrollo de la misma, permitió ampliar el estudio del virus para poder llegar a utilizarlo en un futuro inmediato, como ya se ha mencionado, como agente de control biológico.

I detta examensarbete behandlas en jämförelse mellan två olika material utifrån LCC för GC-broar. Dessa är stål och Delignified Densified Wood (DDW). Samhället är i behov av att utvecklas inom ett mer hållbart- och anpassad till klimatkraven. Detta innebär att det ställs krav på Trafikverket. Dessa krav innebär bland annat att byggnadsmaterial behöver utvecklas. Sverige har god tillgång till skog och träframtagning. Trafikverket bör nyttja mer av träets potential. Denna studie har därför gjorts för att bedöma DDW som är ett träbaserat material utifrån intervjuer och livscykelkostnadsanalys (LCC-analys). LCC är ett tillvägagångsätt för att få en totalbild över en produkts samtliga kostnader under dess livslängd. Det vill säga att för en bro bedöms kostnaderna från projektering till rivning. Syftet med LCC-analys är att hitta den mest lönsamma investeringskostnad som uppfyller dagens samhällskrav. DDW är framtagen av Forskare vid Marylands Universitet. Forskningen har observerat att obehandlat trä går att få lika starkt som stål. Processen innebär att ligninet avlägsnas och träet placeras i tryck under värme på cirka 100 C°. Detta leder till att cellulosafibrerna pressas samman och blir hårdare. Det resulterar förenklat sagt att träet blir mycket hårdare, tåligare och starkare och går att forma och böja. Resultatet av examensarbetet tyder på att DDW inte är lämpligt just nu som konstruktionsmaterial i utomhusklimat och inte är ekonomiskt lönsamt. DDW är vetenskapligt intressant och bör forskas vidare. I dagsläget rekommenderas inte DDW som GC-bromaterial. Trafikverket bör bygga mer GC- broar av trä som passar väl som GC-bromaterial. / n this thesis a comparison is made between two different construction materials based on LCC for pedestrian and cycle bridges. These materials are steel and Delignified Densified Wood (DDW). Today ́s society needs to develop with more sustainable and climate-friendly construction. This need imposes demands on the Swedish transport administration, e.g. that building materials need to be developed. One viable material for Sweden, since it has good access to forestry and wood production, is wood. The Swedish transport administration should use more of the potential of wood. This study therefore assesses DDW, which is a wood-based material, based on interviews and life cycle cost analysis (LCC-analysis). LCC is a way of getting a complete picture of a product's entire costs during its lifespan. In the case of a bridge, the costs are estimated from planning to demolition. The purpose of LCC analysis is to find the most profitable investment cost that meets today's social requirements. DDW is developed by researchers at Maryland University. Researchers have observed that natural wood can be as strong as steel. The process involves removing lignin and placing it under pressure at a temperature of about 100 ° C. This causes the cellulosic fibers to compress and become harder. This simply means that the wood becomes much harder, more durable and stronger, and can also shape and bend. The result of the thesis suggests that DDW is not suitable at present as construction material in outdoor climate and is not economically profitable. DDW is scientifically interesting and should be researched further.

[EN] During viral infections, the outcome of the infective process is a net balance between the compatible and defence interactions. When a virus infects the eukaryotic cell, it must deal with different host defence mechanisms among which RNA silencing is part of the initial plant innate defence response. RNA silencing in plants has the role of restraining viral proliferation in the infected cell and therefore regulates the equilibrium between viral load and plant cell integrity that is key for the plant-virus compatibility. The virus itself is inductor, target and suppressor of the RNA silencing in plants. Viral silencing suppressor proteins (VSR) counteract host antiviral silencing and modify the host gene expression programme to generate a permissive environment for compatible infections. In this PhD thesis we have studied the interface between viral and plant RNA silencing in the context of a compatible infection. Using Tobacco rattle virus (TRV) as a model viral system and Nicotiana benthamiana and Arabidopsis thaliana as host model systems, we have dissected the role of endogenous small RNAs to promote gene silencing responses to viral sequences. Our results point to possible functional interactions between miRNAs and complementary sequences in viral genomes even though the role of those interactions as a viral proliferation controls mechanisms is not part of this thesis. We have found that TRV 16K silencing suppressor protein effects play a central role to dictate the way the TRV and plant RNA silencing interact. The 16K protein avoids, partially, the assembly of silencing effectors complexes and thus compromises the impact of antiviral vsiRNAs-mediated and endogenous small RNAs-mediated RNA silencing. The suppressor effect of TRV does not have a significant impact on the miRNAs content, relative composition and activity although we cannot discard an effect on the metabolisms of some particular miRNA species. / [ES] En las infecciones por virus, el desenlace del proceso infectivo debe entenderse como el resultado neto de las interacciones compatibles y de defensa entre el virus y la planta hospedadora. Cuando un virus entra en una célula eucariota debe lidiar con la activación de diferentes mecanismos de defensa del huésped. El silenciamiento génico mediado por RNA constituye una primera línea de defensa innata de la planta, siendo los propios virus inductores, dianas y supresores de este sistema de defensa. Las plantas a través del silenciamiento génico son capaces de limitar la proliferación viral en las células infectadas permitiendo un delicado equilibrio entre la multiplicación del virus y la integridad celular. Sobre este equilibrio se fundamenta la relación de compatibilidad en la interacción planta-virus. En este escenario, los virus utilizan sus proteínas supresoras de silenciamiento (VSR) para modular los efectos antivirales del silenciamiento y reprogramar la expresión génica del huésped proporcionando un entorno favorable para el desarrollo de la infección compatible Con este trabajo hemos abordado el modo en que los virus interaccionan con el silenciamiento génico en el contexto de una infección compatible. Empleando el virus del cascabeleo del tabaco (TRV) como sistema viral y Nicotiana. benthamiana y Arabidopsis thaliana como modelos de huésped, hemos indagado en el potencial de los pequeños RNAs (sRNAs) endógenos para guiar procesos de silenciamiento sobre secuencias virales. Nuestros resultados suLa manera en que TRV interacciona con la ruta de silenciamiento está condicionada gieren la posibilidad de interacciones funcionales entre microRNAs (miRNAs) y secuencias complementarias en el genoma del virus, si bien su relevancia como mecanismo de control de la proliferación viral no se ha estudiado en este trabajo. por el efecto supresor de la proteína 16K. Esta proteína impide, al menos parcialmente, el ensamblaje de los complejos efectores de silenciamiento y puede por tanto comprometer el efecto del silenciamiento antiviral dependiente de sRNAs tanto virales (vsiRNAs) como endógenos. El efecto supresor de TRV no parece perturbar globalmente el contenido, composición relativa y actividad de los miRNAs, si bien no es descartable que induzca alteraciones en el metabolismo de especies concretas. / [CA] En les infeccions per virus, el desenllaç del procés infectiu ha d'entendre's com el resultat net de les interaccions compatibles i de defensa entre el virus i la planta hoste. Quan un virus entra a una cèl·lula eucariota ha de lluitar amb l'activació de diferents mecanisme de defensa de l'hoste. El silenciament gènic per RNA constitueix una primera línia de defensa innata de la planta, i els propis virus son inductors, dianes i supressors d'aquest sistema de defensa. Les plantes a través d'aquest silenciament, són capaces de limitar la proliferació viral a les cèl·lules infectades, permetent un delicat equilibri entre la multiplicació del virus i la integritat cel·lular. En aquest equilibri es fonamenta la relació de compatibilitat existent a la interacció planta-virus. En aquest escenari, els virus utilitzen les seues proteïnes supressores de silenciament (VSR) per tal de modular els efectes antivirals del silenciament i reprogramar l'expressió gènica de l'hoste, proporcionant un entorn favorable per al desenvolupament de la infecció compatible. Amb aquest treball hem abordat la manera en la que els virus interaccionen amb el silenciament gènic en el context d'una infecció compatible. Emprant el virus del cascavelleig del tabac (TRV) com a sistema viral i Nicotiana. benthamiana i Arabidopsis thaliana com a hostes models, hem indagat en el potencial dels RNAs endògens curts de doble cadena (sRNAs) per guiar processos de silenciament sobre seqüències virals. Els nostres resultats suggereixen la possibilitat de interaccions funcionals entre microRNAs (miRNAs) i seqüències complementàries al genoma del virus, tot i que la seua rellevància com a mecanisme de control de la proliferació viral no ha estat tractat en aquest treball. La manera en la que TRV interacciona amb les rutes de silenciament es troba condicionada per l'efecte supressor de la proteïna 16K. Aquesta proteïna impedeix, al menys parcialment, l'acoblament dels complexos efectors del silenciament i pot llavors comprometre l'efecte del silenciament antiviral depenent de sRNAs, tant virals (vsiRNAs) com endògens. L'efecte supressor de TRV no sembla pertorbar globalment el contingut, composició relativa i activitat dels miRNAs, tot i que no es pot descartar que induïsca alteracions en el metabolisme d'espècies concretes. / Martínez Priego, L. (2016). Actividad antiviral de pequeños RNAs endógenos y supresión de silenciamiento génico por la proteína 16K del virus del cascabeleo del tabaco (TRV) [Tesis doctoral]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/61464

Esta dissertação aborda o cálculo da taxa de crescimento da tensão de restabelecimento transitória (TCTRT), considerando o caso de falha na barra, durante a abertura do primeiro polo e o cálculo da tensão de restabelecimento transitória (TRT) nos primeiros instantes de tempo, incluindo o efeito da capacitância. Os principais casos possíveis de falha na barra foram analisados e os resultados demonstraram a precisão das expressões obtidas. Normalmente, o cálculo da TCTRT e da TRT é feito por meio de simulações em programas de transitórios eletromagnéticos em que há rotinas específicas para a extração dos valores destas, porém, em determinadas condições, podem ocorrer oscilações ou imprecisões numéricas. Por ser um assunto de grande interesse convém desenvolver expressões que possam esclarecer resultados duvidosos sem a necessidade de artifícios de redução do passo de integração a valores muitas vezes não factíveis. As expressões obtidas neste trabalho podem ser utilizadas não só para se obter de forma precisa e simplificada os valores da taxa de crescimento da tensão de restabelecimento transitória de um circuito real, assim como os valores da TRT nos primeiros instantes de tempo. / This study is focused on the rate of rise of transient recovery voltage (RRTRV) calculation considering the case of bus fault, during the first pole to open, and also includes the transient recovery voltage (TRV) calculation, in the first instants of time, including the capacitance effect. The main cases of bus fault have been evaluated and demonstrate that the expressions developed in this study are relevant and with good precision. Usually, the RRTRV and the TRV are calculated with the use of simulation programs, using specific routines, nevertheless, in certain conditions, there might be oscillations and numeric imprecisions which requires a mathematic expression. This topic is of great interest and it is important to have mathematical expressions that could clarify doubtful results. The expressions obtained in this study can be use in a very simples and effective mode to calculate RRTRV and the TRV in the first instants of time, considering a real life circuit.

Esta dissertação aborda o cálculo da taxa de crescimento da tensão de restabelecimento transitória (TCTRT), considerando o caso de falha na barra, durante a abertura do primeiro polo e o cálculo da tensão de restabelecimento transitória (TRT) nos primeiros instantes de tempo, incluindo o efeito da capacitância. Os principais casos possíveis de falha na barra foram analisados e os resultados demonstraram a precisão das expressões obtidas. Normalmente, o cálculo da TCTRT e da TRT é feito por meio de simulações em programas de transitórios eletromagnéticos em que há rotinas específicas para a extração dos valores destas, porém, em determinadas condições, podem ocorrer oscilações ou imprecisões numéricas. Por ser um assunto de grande interesse convém desenvolver expressões que possam esclarecer resultados duvidosos sem a necessidade de artifícios de redução do passo de integração a valores muitas vezes não factíveis. As expressões obtidas neste trabalho podem ser utilizadas não só para se obter de forma precisa e simplificada os valores da taxa de crescimento da tensão de restabelecimento transitória de um circuito real, assim como os valores da TRT nos primeiros instantes de tempo. / This study is focused on the rate of rise of transient recovery voltage (RRTRV) calculation considering the case of bus fault, during the first pole to open, and also includes the transient recovery voltage (TRV) calculation, in the first instants of time, including the capacitance effect. The main cases of bus fault have been evaluated and demonstrate that the expressions developed in this study are relevant and with good precision. Usually, the RRTRV and the TRV are calculated with the use of simulation programs, using specific routines, nevertheless, in certain conditions, there might be oscillations and numeric imprecisions which requires a mathematic expression. This topic is of great interest and it is important to have mathematical expressions that could clarify doubtful results. The expressions obtained in this study can be use in a very simples and effective mode to calculate RRTRV and the TRV in the first instants of time, considering a real life circuit.

The Martin Aircraft Company Limited has been developing the Martin Jetpack for over 25 years. The recent worldwide launch of the Jetpack has enabled the company to step up its research and development programme. The goal of this project was to determine the feasibility of an electrically powered version of the Martin Jetpack. The feasibility of the Electric Jetpack was determined by researching energy storage technologies, researching power cable technologies, simulations of flight times, surveys of electric motors, and the development of a simulation program which was used to optimise some preliminary custom motor designs. The overall conclusion of this project was that the Electric Jetpack was feasible only when it was powered through a tethered power cable, and on-board energy storage was not used. An investigation into current energy storage technologies showed that the Electric Jetpack is not considered feasible when using on-board energy storage, however it is possible to obtain flight for a very short time. The energy storage technologies studied were batteries, fuel cells, and ultra-capacitors. It was found that the best performing technology was the lithium iron nano-phosphate battery. A simulation of flight time showed that this battery type would be able to provide flight for approximately 3.6 minutes. Future trends indicated that the Electric Jetpack with on-board energy storage may eventually be feasible when using a lithium-ion based battery due to improvements being made in energy density and power density. By using a tethered power cable, the weight of the on-board energy storage could be eliminated. This was shown to be a feasible method for powering the Electric Jetpack for applications where the Jetpack needs to only be operated in a small area. The best cable type to use was a multi-stranded flexible cable operating at a high DC bus voltage. The weight of a 5 meter power cable using a 1000 V bus voltage was shown to be 4.9 kg. Potential applications for this kind of Jetpack could include thrill rides and rescue operations from multi-storied buildings. A cable made from carbon nanotubes was shown to be a future technology that could offer a lighter cable. A survey of currently available electric motors showed that none met both the power density and speed required by the Electric Jetpack, even when using a tethered power cable to eliminate the energy storage weight. Because of this, a custom motor design was needed. Research into motor technologies showed that the permanent magnet brushless DC (PMBLDC) motor was the most suited type for the Electric Jetpack. The permanent magnet brushless AC (PMBLAC) motor was also suitable. A PMBLDC motor simulation program was developed using MATLAB which could be used to optimise preliminary custom designs. A characterisation of allowable motor time constants for the PMBLDC motor type was made in order to speed up the simulation time. The optimisation results showed that a power density of 5.41 kW/kg was achievable for the motor when it was located inside the ducted fan tubes, and a power density of 6.56 kW/kg was achievable when the motor was located outside the ducted fans and operated at a higher speed. The motor designs were shown to be within the expected torque per unit rotor volume (TRV) range for aerospace machines. The best power density figures would leave between 37 kg and 42 kg of weight for the motor driver/controller, cable weight, and miscellaneous motor parts. This was considered to be feasible. An FEM simulation was made on one of the optimised motor designs. The FEM results agreed with the parametric results within reasonable accuracy. The parametric back-EMF waveform over-estimated the effects of slotting.

The rate at which a railway track deteriorates depends on the response of the track under different static and repeated dynamic forces. These wheel/rail forces lead to imperfections in the rail surface and deviation in track geometry alignment. The wheel/rail forces are dependent upon the quality of maintenance of the characteristics of both train and track. If train components such as wheelsets and suspensions are maintained to a high standard, less dynamic forces are generated at the wheel/rail interface and less damage is caused over time. Therefore, the amount and cost of maintenance of track are reduced. However, there is little known about how the characteristics of train components affect time-dependent track degradation. Track degradation through deviation of track from its ideal position has the most effect on maintenance costs. Therefore, the present research aims to investigate this track degradation and improve understanding of the effects of train characteristics (such as train mass and speed, suspension stiffness and damping) on railway tracks. The research is conducted by looking into the relationship between wheel/rail forces and track degradation on one hand and between wheel/rail forces and train characteristics on the other hand, with the objective of assisting in managing vehicle/track interaction in order to minimise track degradation. This aim is achieved by investigating the above two relationships to attain the desired relationship between track degradation and train characteristics. The research focuses on wheel/rail vertical forces (both amplitudes and frequencies), vertical track alignment (longitudinal vertical profile), and rail head defects. The study started by collecting wheel/rail vertical forces data in addition to data on vertical track degradation under sustained traffic loads on a heavy haul railway section of track in Central Queensland. Also, five years of degradation and maintenance history data were collected on three other test sections of railway track under variety of traffic conditions and loads in Central Queensland. There were four main analyses of this data employed to probe the study. The first analysis was performed by examining the track degradation history data. The standard deviation method was used in this first analysis to acquire the rate of deterioration in terms of its relationship to track profile (roughness). The second analysis was accomplished by correlating the vertical wheel/rail forces to both vertical track profile and rail roughness using signal processing principles and a function know as coherence. The third analysis was carried out by using the computer simulation software NUCARS to obtain the link between wheel/rail forces and the deterioration of the vertical track profile. The fourth analysis was achieved by combining the results obtained from the above three analyses to acquire the rate of track deterioration in terms of its relationship to varying train characteristics. The first analysis mentioned above quantified the relationship between the level of roughness of the track and rate at which that roughness deteriorated. An important outcome of this relationship is that there is a threshold of roughness below which track deterioration is minimal. The track maintenance planners can now use that threshold for cost effective targeting of tamping activities. The correlation study between track roughness and wheel/rail forces using the coherence function found, surprisingly, that the overall deterioration of the track roughness, in the absence of frequencies of forces above 30 Hz, is due to the so-called quasi-static lower frequency oscillations of dynamic forces. This conclusion together with the relationship between vehicle characteristics and track forces, established in the analyses above, has significant implications for the design of wagon bogies and for charges track owners might levy on trains using their tracks. This research is part of a larger Rail CRC project 11/4 called 'Enhancing the Optimisation of Maintenance/Renewal' being carried out in the School of Urban Development in Queensland University of Technology.