Photic-zone euxinia (PZE) is associated with several times in Earth's history including Phanerozoic extinction events and long parts of the Proterozoic. One of the best modern analogues for extreme PZE is Mahoney Lake in British Columbia, Canada where a dense layer of purple sulfur bacteria separate the oxic mixolimnion from one of the most sulfidic monimolimnions in the world. These purple sulfur bacteria are known to produce the carotenoid okenone. Okenone's diagenetic product, okenane, has potential as a biomarker for photic-zone euxinia, so understanding its production and transport is important for interpreting the geologic record. In the following dissertation, I examine Mahoney Lake with a multi-proxy approach. I use lipid biomarkers to understand organic matter production burial in the lake and find strong evidence of lateral transport of organic matter from shoreline microbial mats to the lake-bottom sediments. I also find evidence of okenone production in these shoreline mats and a carotenoid previously unreported in the environment, Thiothece-484, associated with the okenone synthetic pathway. Finally, I develop a new bioinformatics method to examine high-throughput metagenomic data and use this method to start understanding how the metabolic and lipid synthetic pathways of microbial communities in the lake are associated with each other. / Earth and Planetary Sciences

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Écrites pour empêcher que les faits humains étaient oubliés avec le temps, les Histoires d’Hérodote d’Halicarnasse soulignent, depuis le proême, leur potentiel de pérennisation. En réalisant son entreprise après la fin des guerres contre les perses, il veut préserver les actions de ceux qui, à son avis, méritent d’être rappelés. L’historien émerge en tant que figure d’auteur qui revendique la capacité de préserver les réalisations des êtres humains. S’agit-il aussi d’une préservation de soi-même en tant qu’auteur ? Cette thèse vise à répondre à la question posée. La Grèce des póleis a vu survenir la figure de l’auteur. Des nombreux auteurs grecs ont exprimé la volonté de signer leurs oeuvres. La présence autorielle de l’historien est inséparable du contenu exposé dans le texte. Il s’agit donc d’une quête de préservation de son propre kléos, ce qu’on peut vérifier dans sa signature ou sphragís, bien que dans le moi de l’écrivain et son dialogue avec le lecteur future. Pour atteindre son but, Hérodote dispose de l’écriture de l’histoire, un outil pour résister à Khrónos, cette figure qui représente le temps destructeur. / Escrita para impedir que os feitos humanos fossem esquecidos com passar do tempo, as Histórias de Heródoto de Halicarnasso sublinham, desde o proêmio, seu potencial perenizador. Realizando seu empreendimento após o fim das guerras contra os persas, ele pretende preservar as ações daqueles que, na sua opinião, merecem ser lembrados. O historiador surge como figura autoral que reivindica a capacidade de preservar as realizações humanas. A busca de preservação dos outros se refere de algum modo à preservação de si próprio? Esta tese consiste em uma tentativa de responder positivamente a esta questão. A Grécia das póleis vê surgir a ênfase cada vez mais demarcada da figura autoral. É grande a lista de autores gregos que manifestaram a vontade de assinar o nome em suas obras e os poetas, talvez, sejam o maior exemplo disso. Quanto ao historiador, que em muito se refere à poesia, sua presença autoral se tornou algo indissociável do conteúdo apresentado no texto. Trata-se, então, de uma busca de fazer com que seu kléos seja conhecido pela posteridade, o que podemos compreender se considerarmos alguns elementos presentes no seu texto, como a assinatura ou sphragís, a presença constante do eu do autor e uma espécie de “diálogo” com o leitor futuro. Para tal intento, Heródoto dispõe da sua escrita da história, uma ferramenta utilizada para resistir a Khrónos ou o tempo, que a todos destrói.

La manifestation d‟auteur est un élément que peut être facilement verifié dans les Histoires d‟Hérodote d‟Halicarnasse. Depuis la présentation du nom propre au début de l‟ouvre (sa sphragis), grâce à l‟utilization fréquent du moi dans le récit, l‟auteur se présente comme responsable de la propre production. Et le résultat est l‟emphase sur la figure de celui qui a effectué la recherche, ce qui signifie un contraste important si on les comparé aux productions des poètes grecs. Cette thèse se compose d‟une recherche dont l‟objectif est d‟examiner la manifestation auctorale d‟Hérodote à partir de la présence de poètes dans l‟Histoires. Ils ont été analysés les extraits où ils sont mentionnés, a fin de montrer la distance établie par Hérodote et l‟émergence de l‟auteur dans sa ouvre. / A manifestação autoral é um elemento que pode ser facilmente verificado nas Histórias de Heródoto de Halicarnasso. Desde a apresentação do nome próprio no início da obra (sua sphragis), passando pelo frequente uso do eu na narrativa, o autor apresenta a si próprio como o responsável pela produção. E o resultado é a ênfase na figura daquele que executou a investigação, o que significa um importante contraste se comparado às produções dos poetas gregos. Esta dissertação consiste em uma investigação cujo objetivo é examinar a manifestação autoral herodotiana a partir da presença dos poetas nas Histórias. Foram analisadas as passagens em que estes são mencionados, no intuito de mostrar o distanciamento estabelecido por Heródoto, e a emergência do autor em sua obra.

[by] Adrianus J.M. Houtsma and Julius L. Goldstein. / Based on a Ph.D. thesis in the Dept. of Electrical Engineering, 1971, by A.J.M. Houtsma. / Bibliography: p. 71-75.

The visual domain design constitutes the general designers communication basis for communicating messages of product attributes. In the design of an automobile seat where mainly the accommodating functions remain constant, an automobile seat&rsquo / s &ldquo / style&rdquo / affords the ability to provide certain meanings with affective connotations. Treating style aesthetics as a source of information, the communication of &ldquo / comfort&rdquo / can be provided via forms and other attributes. The literature provides strong evidence that comfort is related with aesthetics of any object in use, especially creating expectations towards the product. The &ldquo / Aesthetics of comfort&rdquo / can be explained as a variable intensity &ldquo / feeling&rdquo / or &ldquo / attitude&rdquo / regarding an entity of factors or characteristics of a multidimensional construct. Implemented by different layouts and cues, the consumer should be assisted in understanding the qualities of an automobile seat, such as comfort. As a result of the field study conducted, significant difference was found to exist in between the perception of visual comfort three production seat designs. A positive attitude about comfort towards an automobile seat was found to be influential in positively effecting the perception of seated comfort.

The aerodynamical design of a solar race car is presented together with the racing strategy. Dealing with the design and the racing strategy simultaneously offers the advantage of having improvements on both, using the results of each other. Besides these, as a prerequisite of the design, the decision on number of the wheels is discussed. If the three wheel configuration is selected, the requirements for having the desired performance while eliminating the risk of tipping over are inspected. In the aerodynamics analyses, the software packages Gambit and Fluent are utilized. Using the results of the CFD simulations, aerodynamical shape of the body is analyzed to determine weak points of the design, causing early boundary layer detachment and higher drag. The drag coefficient of the body is also obtained from CFD runs at various speeds. It was determined that the selected NACA profile performs well, under racing speeds but the canopy design is open to improvement. The racing strategy is analyzed using the race track information together with the design of the solar car. A program was created to determine the position, velocity, acceleration and power consumption versus time. Also the lap time and total energy consumption can be obtained and these are vital data while determining their sensitivity to mass or to resistances. By the help of this program, the experience gained by completing laps on the circuit can be partially gained without actual laps.

This thesis analyzes design criteria&rsquo / s, performance evaluation of fuel filter. Fundamental concepts, definition and systems has been discussed at literature survey parts. Fundamentals of filter design tests and calculations are discussed. In Addition Frequency and amplitude effect on fuel filter efficiency investigated with different particle sizes by preparing special test set up. Test results has been analyzed by using Regression, Anova and Analyze of Variance methods with Minitab software.

In this study, a method to predict vehicle pass-by noise in a finite dimensioned, semi-anechoic chamber with chassis dynamometer has been developed. Vehicle noise has been modeled as the summation of the individual contributions regarding the principal noise components, namely, engine including air intake, front tire and rear tire noises. This method employs wave propagation, Doppler shift, and time delay in the estimation of the sound pressure due to each component at points of interest specified by relevant standards. An acoustical simulation model has been developed in MaTLAB environment. The model has been applied on two different vehicles. Finally, the predicted sound pressure values are found to be in good agreement with the corresponding values acquired in outdoor measurements addressed in ISO 362 for vehicle pass-by noise measurement standard.

The aim of this study is to experimentally measure performance characteristics of a compression ignition (CI) internal combustion engine using superheated ethanol vapor. The engine is a 1.3L inline 4 cylinder direct injection (DI) turbocharged compression ignition (CI) engine. While the engine will be fed with superheated ethanol as homogeneous fuel-air mixture through intake manifold, the amount of diesel fuel that the engine requires to run at idle will also be supplied in order to initiate combustion. Ethanol will be superheated using a new patented double heat exchanger has been manufactured by Prof. Dr. Demir Bayka, Dr. Anil Karel and Deniz &Ccedil / akar. The results will indicate if the suggested concept can be applicable.