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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

An experimental study of electron transfer and emission during particle-surface interactions

McGrath, Caith Thomas January 2000 (has links)
No description available.
132

Experimental and modelling studies of coal/biomass oxy-fuel combustion in a pilot-scale PF combustor

Jurado Pontes, Nelia January 2014 (has links)
This thesis focuses on enhancing knowledge on co-firing oxy-combustion cycles to boost development of this valuable technology towards the aim of it becoming an integral part of the energy mix. For this goal, the present work has addressed the engineering issues with regards to operating a retrofitted multi-fuel combustor pilot plant, as well as the development of a rate-based simulation model designed using Aspen Plus®. This model can estimate the gas composition and adiabatic flame temperatures achieved in the oxy-combustion process using coal, biomass, and coal-biomass blends. The fuels used for this study have been Daw Mill coal, El Cerrejon coal and cereal co-product. A parametric study has been performed using the pilot-scale 100kWth oxy-combustor at Cranfield University and varying the percentage of recycle flue gas, the type of recycle flue gas (wet or dry), and the excess oxygen supplied to the burner under oxy-firing conditions. Experimental trials using co-firing with air were carried out as well in order to establish the reference cases. From these tests, experimental data on gas composition (including SO3 measurement), temperatures along the rig, heat flux in the radiative zone, ash deposits characterisation (using ESEM/EDX and XRD techniques), carbon in fly ash, and acid dew point in the recycle path (using an electrochemical noise probe), were obtained. It was clearly shown during the three experimental campaigns carried out, that a critical parameter was that of minimising the air ingress into the process as it was shown to change markedly the chemistry inside the oxy-combustor. Finally, part of the experimental data collected (related to gas composition and temperatures) has been used to validate the kinetic simulation model developed in Aspen Plus®. For this validation, a parametric study considering the factor that most affect the oxy-combustion process (the above mentioned excess amount of air ingress) was varied. The model was found to be in a very good agreement with the empirical results regarding the gas composition.
133

Le calcul parallèle des plus courts chemins temporels

Pépin, Jean-Nicolas January 2003 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
134

Planification de tournées de véhicules pour le problème de livraison à domicile

Azi, Nabila January 2004 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
135

Phylogenetic shadowing using a model selection process

Shakiba, Mashid January 2006 (has links)
Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.
136

Nabytí od neoprávněného / Acquisition of property from unlawful possessor

Hradil, Aleš January 2014 (has links)
ACQUISITION OF PROPERTY FROM UNLAWFUL POSSESSOR In my diploma thesis I deal with the issue of the acquisition of property from unlawful possessor as an exception to the traditional civil law principle nemo plus iuris ad alium transferre potest quam ipse habet (also called as nemo dat rule), the principle, which lays down that no one can transfer more rights than he has himself. The topic is extremely actual since as of 1st of January 2014 the Act No. 89/2012 Coll., The Civil Code, which - in comparison to the previous legislation - provides diametric changes in the understanding and in the legislation of the property acquisition from unlawful possessor, became effective. Until the adoption of the new Civil Code, the legislation in this area was inadequate and due to dichotomy between Civil and Commercial Code it was also fragmented. The thesis is composed of an introduction, five main chapters (which are further divided into sub-chapters) and a conclusion. Each chapter deals with different aspects of acquisition of property from unlawful possessor. In the first introductory part I give my thesis some theoretical fundamentals and define basic terminology used in this paper: property, good faith. I'm also trying to analyze nemo plus iuris principle and conflict of protection of property rights with the...
137

Stored-grain insect management with insecticides: evaluation of empty- bin and grain treatments against insects collected from Kansas farms

Sehgal, Blossom January 1900 (has links)
Master of Science / Department of Grain Science and Industry / Bhadriraju Subramanyam / The insecticides, β-cyfluthrin and chlorpyrifos-methyl plus deltamethrin, are approved in the United States for treating empty bin surfaces. Chlorpyrifos-methyl plus deltamethrin and spinosad insecticides are approved for direct treatment of wheat. The efficacy of commercial formulations of β-cyfluthrin and chlorpyrifos-methyl plus deltamethrin at labeled rates was evaluated against adults of 16 field strains of the red flour beetle, Tribolium castaneum (Herbst); seven strains of sawtoothed grain beetle, Oryzaephilus surinamensis (L.); and two strains of the lesser grain borer, Rhyzopertha dominica (F.). Concrete arenas in plastic Petri dishes (9 cm diameter) were used to simulate the concrete floor of empty bins. The time for ~100% knockdown and mortality of adults of laboratory strains of the three species was first established by exposing them to insecticide-treated concrete surfaces for 1 to 24 h. Adults of field strains of each species were exposed to specific established insecticide-time combinations. Mortality of all species was lower than knockdown, suggesting recovery after seven days when placed on food. Chlorpyrifos-methyl plus deltamethrin did not control all R. dominica and most O. ]surinamensis field strains. β-cyfluthrin was extremely effective against R. dominica but ineffective against T. castaneum and O. surinamensis field strains, even at four times the high labeled rate. Field strains of R. dominica were highly susceptible to spinosad and chlorpyrifos-methyl plus deltamethrin at labeled rates on hard red winter wheat. Strains of T. castaneum and O. surinamensis were susceptible only to the latter insecticide. Dose-response tests with spinosad on the two least susceptible field strains of each species showed the lethal dose for 99% mortality (LD[subscript]99) for T. castaneum and R. dominica field strains were similar to that of the corresponding laboratory strains. Corresponding values for the two O. surinamensis field strains were significantly greater (~6 times) than the laboratory strain. The effective dose for progeny reduction (ED[subscript]99) of only one R. dominica field strain was significantly greater (~2 times) than that of the laboratory strain. The baseline susceptibility data of field strains of three insect species to spinosad will be useful for monitoring resistance development once this product is commercially released as a grain protectant.
138

Exergy analysis and heat integration of a pulverized coal oxy combustion power plant using ASPEN plus

Khesa, Neo January 2017 (has links)
A dissertation submitted to the faculty of Engineering and the Built Environment, University of the Witwatersrand, in fulfillment of the requirements for the degree of Master of Science in Engineering. 21 November 2016 / In this work a comprehensive exergy analysis and heat integration study was carried out on a coal based oxy-combustion power plant simulated using ASPEN plus. This is an extension on the work of Fu and Gundersen (2013). Several of the assumptions made in their work have been relaxed here. Their impact was found to be negligible with the results here matching closely with those in the original work. The thermal efficiency penalty was found to be 9.24% whilst that in the original work was 9.4%. The theoretical minimum efficiency penalty was determined to be 3% whilst that in the original work was 3.4%. Integrating the compression processes and the steam cycle was determined to have the potential to increase net thermal efficiency by 0.679%. This was close to the 0.72% potential reported in the original work for the same action. / MT2017
139

Modelagem estocástica do labirinto em cruz elevado / Elevated Plus Maze: a Stochastic Modeling

Arantes, Rafael 27 September 2016 (has links)
O labirinto em cruz elevado é muito usado em estudos relacionados à ansiedade em ratos. As medidas tradicionalmente usadas são o número de entradas e o tempo passado nos braços abertos. Trabalhos recentes analisam a movimentação no interior dos braços, mas não propõem um índice que resuma as análises feitas. Esta tese sintetiza as informações de um destes trabalhos em índices. Um dos índices propostos usa os tempos médios de primeira visita a cada posição do labirinto e o outro se baseia na distribuição estacionária de probabilidade, o primeiro é capaz de diferenciar grupos de ratos submetidos a diferentes drogas ansiolíticas. Além disso, a tese propõe um modelo de processo Markoviano que incorpora informações desconsideradas no modelo anterior. A comparação entre os modelos revelou valores super ou subestimados no primeiro. Por fim, esta tese propõe um modelo de cadeias de Markov considerando como estados o seguinte conjunto de comportamentos: \"rearing\", \"stretching\", \"dipping\", \"freezing\" e \"grooming\". Tal abordagem inédita, apesar de simplificar exageradamente o modelo, foi capaz de reproduzir várias características conhecidas da exploração. / The elevated plus maze is widely used in studies related to anxiety in rats. The most widely used measures are the amount of entries and time spent on open arms. Recent studies analyze the movement inside the arms, but do not propose an index that summarizes the analyzes. This thesis summarizes by indices the information in one of these studies. An index uses the first visit average time to each position of the maze and another is based on the stationary probability distribution, the first one are able to differentiate groups of rats submitted to different anxiolytic drugs. These thesis also proposes a Markov process model that incorporates more information than the other model. The comparison between the models showed over- or underestimated values in the first. Finally, this thesis proposes a Markov chains model considering the following behaviors as states: rearing, stretching, dipping, freezing and grooming. This new approach, though oversimplify the model was able to reproduce several known features of exploitation.
140

Teoremas fundamentais para o caminho mais curto entre duas sequências / Théorèmes fondamentaux pour le plus court chemin entre deux sequences

Lambert, Rodrigo 17 June 2015 (has links)
Definimos a função caminho mais curto como sendo a mínima quantidade de passos para que uma realização do processo com condição inicial y atinja um conjunto-alvo x. Para tal função, provamos três resultados principais: um teorema de concentração de massa, um princípio de grandes desvios, e uma convergência em distribuição. / Dans ce travail, nous étudions les propriétés de le chemin le plus court entre deux sequences, et en présente trois principaux résultats: Le premier est le comportement asymptotique de le chemin le plus court comme une fonction linéaire de la taille de les cylindres. Le deuxième est un principe de grandes déviations pour cette quantitée. Et le troisième est de la convergence en distribution d\'une version re-mise à l\'échelle de cette variable aleatorie.

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