The mainly research is by adding the rare-earth metal gadolinium salts with sol-gel process to form the gadolinium -doped titanium dioxide, and by forming the liquid crystal template with the non-ionic surfactant to form the mesostructure of titanium dioxide. And the research has aimed at the using different non-ionic surfactant, the different pH value, the different solvent of water/ethanol ratio, the hydrothermal process or not, and the gadolinium content. We discussed these factors how to affect the titanium dioxide in the physical property, the chemical property, or structure influence. Using the XRD to measure the mesostucture of titanium dioxide and the crystallization of titanium dioxide, and we observe the shape and particle size of titanium dioxide with SEM. We use UV-visible spectrum to observe absorption spectrum of titanium dioxide. The result discovers that surfactant effect is using triblock copolymer, poly (ethylene oxide) - poly (propylene oxide) - poly (ethylene oxide), the titanium dioxide has anatase and rutile crystallization, and particle aggregation. The pH affects the partic le size and the shape. In pH is 5.8, the titanium dioxide has anatase and rutile crystallization. In water/ethanol ratio effect, we use solvent including ethanol, the titanium dioxide has anatase and rutile. Through hydrothermal process, titanium dioxide has little brookite crystallization and the few fibrous titanium dioxides. The doping gadolinium effect is the anatase is reducing with gadolinium content increasing, and from the UV-visible spectrum, the doping gadolinium titanium dioxide has the red shift. The titanium dioxide using polyoxyethylene sorbitan monostearate and doping gadolinium has the anatase, and absorbs a longer wavelength, and when the doping content is 1% titanium dioxide has a better absorption.

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

The purpose of this work was to study the possibility of creating Gd2O3-nanoparticles by spark generation. For this, the Palas GFG 1000 aerosol generator was used with much positive results. The potential possibilities to tune the physical properties of the nanoparticles by varying a set of experimental parameters during the fabrication process have been studied. This was investigated by comparing particles made by two different types of methods: wet chemistry (colloids), which was used in an earlier study, and an aerosol technique (aerosols), that was explored in this study. In this work, the production of 10, 20 and 40 nm particles with a high yield was obtained. Reducing the size even more proved to be troublesome. It was only possible to create a small amount of 5 nm sized particles. The reason for this is still not clear and will have to be further studied. One drawback with the fabrication procedure that was used for this work, the aerosol method, is that the amount of particles that was created is low compared to the amount of particles created by the earlier investigated modified polyol method. In the future this amount can be increased either by connecting several generators in parallel or by increasing the efficiency of the neutralizer. Description of the production and characterization of nanometer sized Gd2O3-particles constitute the main part of this work. Agglomerated particles was created by a vaporization/condensation-method and deposited onto silicon substrates for characterization. SEM studies were made in order to compare concentrations of produced particles made by the aerosol method and by the modified polyol method. For characterization, TEM investigations were made to study particle size, morphology and reshaping behavior before and after sintering was done. By using the results obtained in this work several new projects can be explored. This is very promising for future tries when a full characterization concerning spark gap-distance, gas flow and sintering temperature will be done.

Fler och fler webbapplikationer låter sina användare ladda upp bilder. Ibland behöver dessa bilder manipuleras på något sätt, till exempel förminskas eller beskäras för att bättre passa in på webbsidan. Detta kan göras på flera olika sätt men denna rapport behandlar endast ett av biblioteken för bildmanipulation i PHP, nämligen GD-biblioteket.Syftet med denna rapport var att hitta eventuella styrkor och svagheter i detta bibliotek gällande bildmanipulation. Detta har gjorts genom att försöka skapa, för webben vanlig funktionalitet så som exempelvis tumnaglar, beskärning och vattenmärkning och sedan dokumentera resultatet.Resultatet av testningen visade att all testad funktionalitet gick att åstadkomma och slutsatsen som drogs av detta var att GD-biblioteket är ett bra val för någon som vill manipulera bilder. / More and more web applications allow its users to upload images. Sometimes you need these images manipulated in a way, such as reduce or crop it to better fit on the website. This can be done in various ways, but this report deals only with one of the libraries for image manipulation in PHP, namely the GD library.The purpose of this report was to identify potential strengths and weaknesses of this image processing library. This has been done by trying to create, typical web functionalities such as thumbnails, cropping and watermarking and then documenting the results.The results of the testing showed that all tested functionality was achievable and the conclusion drawn from this was that the GD library is a good choice for anyone who wants to manipulate images.

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

Submitted by PPG Engenharia El?trica (engenharia.pg.eletrica@pucrs.br) on 2018-01-16T12:25:22Z No. of bitstreams: 1 Dissertacao Henrique Cabral Final.pdf: 7113504 bytes, checksum: 991064508825d35b392d6e41b5e9023f (MD5) / Approved for entry into archive by Caroline Xavier (caroline.xavier@pucrs.br) on 2018-01-26T13:01:29Z (GMT) No. of bitstreams: 1 Dissertacao Henrique Cabral Final.pdf: 7113504 bytes, checksum: 991064508825d35b392d6e41b5e9023f (MD5) / Made available in DSpace on 2018-01-26T13:06:39Z (GMT). No. of bitstreams: 1 Dissertacao Henrique Cabral Final.pdf: 7113504 bytes, checksum: 991064508825d35b392d6e41b5e9023f (MD5) Previous issue date: 2016-08-29 / This work presents a study and a development of a current source microinverter, based on the ?uk converter operating in discontinuous conduction mode, for microgeneration purposes based on photovoltaic systems. In this sense, we carried out a steady-state analysis of the ?uk converter, in order to establish the design criteria for the ?uk microinverter. All peripheral systems required for the microinverter operation have also been developed, and are included in this study, namely: the MPPT, PLL, and islanding detection algorithms. All control systems, i.e., the MPPT, PLL, and anti-islanding detection algorithms, were implemented in the DS1104 R&D controller board, from dSPACE?, using MATLAB/Simulink? to program it. / Este trabalho apresenta o estudo e o desenvolvimento de um microinversor de corrente, baseado no conversor ?uk, operando no modo de condu??o descont?nua, para a aplica??o em microgera??o fotovoltaica. Inicialmente, s?o desenvolvidos estudos de car?ter qualitativo e quantitativo do comportamento do microinversor de corrente baseado no conversor ?uk, os quais culminaram no desenvolvimento de crit?rios para o dimensionamento do conversor ?uk, que desempenha um papel central na estrutura do microinversor proposto. Sistemas perif?ricos necess?rios para a opera??o do microinversor, assim como aqueles exigidos pelas concession?rias de energia el?trica para a aplica??o em sistemas de microgera??o s?o estudados e desenvolvidos nessa disserta??o. Para tanto, a implementa??o de todos os sistemas de controle, ou seja, os algoritmos de MPPT, de sincronismo, e de detec??o da opera??o ilhada, foram realizados em ambiente MATLAB/Simulink? associada ? uma placa de desenvolvimento do fabricante alem?o dSPACE?, modelo DS1104, a qual permite o controle em tempo real dos transistores do microinversor.

The presented thesis focused on the study of a new material concept of Ce3+ doped multicom- ponent aluminum garnets (GdLu)3(GaAl)5O12. High purity single crystalline epitaxial films were grown by the method of liquid phase epitaxy from the BaO-B2O3-BaF2 flux with spe- cial emphasis on the elimination of the potential impurities coming from the flux. Combined experimental study of photoelectron yield (under alpha excitation), decay kinetics of fast and delayed recombination in the milisecond time range (under e-beam excitation) and photo-, cathodo- and radio-luminescence spectroscopies were used to characterize the studied mater- ial. The single-step nonradiative energy transfer from the donor Gd3+ to an acceptor Ce3+ was observed in the low Gd, Ce doped LuAG films and established as long-range dipole - dipole interaction. Special attention was devoted to the positive effect of combined Gd and Ga substitution on the extensive suppression of shallow traps, which are responsible for the slow component in the scintillation response. The best obtained scintillation characteristics of the studied epitaxial films were comparable with the top performance bulk crystals. 1

abstract: A process plan is an instruction set for the manufacture of parts generated from detailed design drawings or CAD models. While these plans are highly detailed about machines, tools, fixtures and operation parameters; tolerances typically show up in less formal manner in such plans, if at all. It is not uncommon to see only dimensional plus/minus values on rough sketches accompanying the instructions. On the other hand, design drawings use standard GD&T (Geometrical Dimensioning and tolerancing) symbols with datums and DRFs (Datum Reference Frames) clearly specified. This is not to say that process planners do not consider tolerances; they are implied by way of choices of fixtures, tools, machines, and operations. When converting design tolerances to the manufacturing datum flow, process planners do tolerance charting, that is based on operation sequence but the resulting plans cannot be audited for conformance to design specification. In this thesis, I will present a framework for explicating the GD&T schema implied by machining process plans. The first step is to derive the DRFs from the fixturing method in each set-up. Then basic dimensions for the features to be machined in each set up are determined with respect to the extracted DRF. Using shop data for the machines and operations involved, the range of possible geometric variations are estimated for each type of tolerances (form, size, orientation, and position). The sequence of manufacturing operations determines the datum flow chain. Once we have a formal manufacturing GD&T schema, we can analyze and compare it to tolerance specifications from design using the T-map math model. Since the model is based on the manufacturing process plan, it is called resulting T-map or m-map. Then the process plan can be validated by adjusting parameters so that the m-map lies within the T-map created for the design drawing. How the m-map is created to be compared with the T-map is the focus of this research. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2015

abstract: Parts are always manufactured with deviations from their nominal geometry due to many reasons such as inherent inaccuracies in the machine tools and environmental conditions. It is a designer job to devise a proper tolerance scheme to allow reasonable freedom to a manufacturer for imperfections without compromising performance. It takes years of experience and strong practical knowledge of the device function, manufacturing process and GD&T standards for a designer to create a good tolerance scheme. There is almost no theoretical resource to help designers in GD&T synthesis. As a result, designers often create inconsistent and incomplete tolerance schemes that lead to high assembly scrap rates. Auto-Tolerancing project was started in the Design Automation Lab (DAL) to investigate the degree to which tolerance synthesis can be automated. Tolerance synthesis includes tolerance schema generation (sans tolerance values) and tolerance value allocation. This thesis aims to address the tolerance schema generation. To develop an automated tolerance schema synthesis toolset, to-be-toleranced features need to be identified, required tolerance types should be determined, a scheme for computer representation of the GD&T information need to be developed, sequence of control should be identified, and a procedure for creating datum reference frames (DRFs) should be developed. The first three steps define the architecture of the tolerance schema generation module while the last two steps setup a base to create a proper tolerance scheme with the help of GD&T good practice rules obtained from experts. The GD&T scheme recommended by this module is used by the tolerance value allocation/analysis module to complete the process of automated tolerance synthesis. Various test cases are studied to verify the suitability of this module. The results show that software-generated schemas are proper enough to address the assemblability issues (first order tolerancing). Since this novel technology is at its initial stage of development, performing further researches and case studies will definitely help to improve the software for making more comprehensive tolerance schemas that cover design intent (second order tolerancing) and cost optimization (third order tolerancing). / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2016

L’excès de réactivité neutronique dans les centrales nucléaires est compensé par des sys-tèmes actifs de contrôle du réacteur : acide borique et barres de contrôle. L’apport d’antiréactivité peut se faire passivement avec des poisons consommables, c'est-à-dire des absorbants de neutrons, en particulier du gadolinium (Gd).Dans le cadre d’une augmentation de l’enrichissement en U²³⁵ et de réduction de l’utilisation d’acide borique, cette thèse a pour objectif d’optimiser la distribution du ga-dolinium dans des céramiques d’UO₂ afin d’obtenir un apport optimisé d’antiréactivité dans un Réacteur à Eau sous Pression.Dans ce sens, le travail est orienté à trouver des nouveaux matériaux riches en gadolinium. Le diagramme de phase U-O-Gd a donc été exploré dans le domaine des fortes teneurs en Gd. Deux phases cubiques ont été trouvées et caractérisées : les phases C1 et C2. En vue d’une application industrielle, la phase C1 a été retenue comme candidate pour l’ajout du Gd dans les pastilles d’UO₂.La distribution optimale de cette phase C1 dans les assemblages de combustible nucléaire a été étudiée avec le code de calcul neutronique APOLLO2.8. Des études paramétriques ont été réalisées. Ces études neutroniques ont aboutit à un concept performant de pastille empoisonnée. Finalement, des pastilles prototype ont été fabriquées en laboratoire suivant ce concept. L’ensemble des résultats obtenus montre qu’un concept de pastille avec un dépôt superficiel neutrophage de phase C1 est une manière d’apporter de l’antiréactivité de manière optimisée dans le cadre de cycles longs. Ceci pourrait potentiellement être appliquée à l‘échelle industrielle. Un brevet a été déposé en ce sens. / Reactivity excess in Nuclear Power Plants is controlled by reactor’s active systems: boric acid dilution and control rods. Alternatively, negative reactivity insertion can be made in a passive way using burnable poisons, i.e. neutron absorbers, this is the case of gadolinium (Gd).In the industrial framework of U²³⁵ enrichment increase and boric acid restraint, the goal of this thesis is to optimize the distribution of gadolinium in UO₂ ceramics to obtain a high-performance provision of negative reactivity in Pressurized Water Reactors.In this sense, the work is focus on new gadolinium-rich materials. Thus, U-Gd-O phase diagram was explored in the field of high Gd contents. Two cubic phases were found and characterized: the C1 and C2 phases. With the aim of an industrial application, C1 phase was selected as candidate for Gd addition into UO₂ pellets.The optimal distribution of C1 phase within a nuclear fuel assembly was studied using APOLLO 2.8 neutron transport code. Parametrical calculations were performed. These neutronic studies have ends in a successful “concept of poisoned pellet”.Finally, some prototype pellets following this concept were made in laboratory to proof it feasibility.All the obtained results shows that the proposed concept of a neutrophage C1-phase coating on UO₂ pellets is a convenient way to reduce reactivity excess within the framework of long irradiation cycles. This concept could be potentially applied in industrial scale. Consequently a patent application process was initiated.