Large trucks may have an integrated microwave oven, or a driver may add oneas a standalone solution, to allow heating food during long-haul transports. If a crash occurs with an item inside the oven, it may thrust against the door with such force that it opens from the inside. The goal of this thesis work is to develop a concept for a universally applicable solution that prevents flying parts from within the oven on a crash, as that presents a safety hazard for anyone inside the cabin. The thesis work was conducted according to a stage gate process, which included four phases: Context, Ideation, Concept Development, and Concept Design. It includes interviews, company visits, literature searches, design methodology, concept comparisons and computer aided design. The thesis work concludes with three concepts, all of which are locking solutions that are applied externally onto a microwave oven. They include a bolt latch, a solenoid lock, and a bolt latch integrated with the oven’s door button. All solutions traverse the transition area between door and panel.

La thèse est consacrée à la recherche des catastrophes marines (tsunamis, ondes de tempête) dans les Antilles françaises, en utilisant des modèles analytiques et numériques de mécanique des fluides. L'accent est mis sur le développement de modèles de mouvement de glissements de terrain et des vagues causées par ces glissements. Le modèle le plus simple du glissement de terrain «solide block» est utilisé pour évaluer les caractéristiques des flux pyroclastiques du volcan Soufrière-Hills (Montserrat). Un modèle plus complexe de modélisation de glissement de terrain (modèle de Savage-Hutter) a été étudié analytiquement, donnant ainsi une nouvelle famille de solutions exactes décrivant le mouvement de l'écoulement par gravité non linéaire dans une vallée ou dans un canyon sous-marin. Le modèle comprend des ondes simples (Riemann waves),le cas d'un barrage qui cède (dam-break problem), des solutions auto-similaires dans la M-fonne et « chapeaux paraboliques ». Grâce à la théorie linéaire de l'eau peu profonde nous avons étudié le processus de génération de tsunamis par des glissements de terrain de volume variable, se déplaçant à une vitesse variable dans un bassin de profondeur variable. Dans le cas d'un fond marin particulier (cas sans "réflexion"), les phénomènes de résonnance ont été étudiés dans un bassin à profondeur variable. Nous avons utilisé des méthodes numériques pour la résolution non-linéaire des équations des eaux peu profondes afin d'analyser des catastrophes marines réelles (les ondes de tempête causées par le cyclone Lili en 2002, le tsunami volcanique de 2003 à Montserrat) et probables (un tsunami prés des côtes de la Martinique). Des données sur les catastrophes / The dissertation is devoted to research in the field of marine natural hazards (tsunamis, storm surges) in the French West Indies, using analytical and numerical models of fluid mechanics. Emphasis is placed on the development of models of landslide motion and generated tsunami waves. The simple "solid block" model is used to evaluate the characteristics of pyroclastic flow Soufriere Hills volcano (Montserrat). The "fluid model" of a landslide (so called Savage-Hutter model) is studied analytically; within this model a new family of exact solutions that describe the motion of nonlinear gravity flow in a valley or underwater canyon is found: nonlinear Riemann wave, dan break problem, self-similar solutions (M - wave and parabolic cap). In the framework of the linear shallow water theory the process of generation of tsunami waves by landslides of variable volume moving with variable velocity above the basin of variable depth is studied. For the specific bottom profile ("reflectionless" one) the resonant phenomena is investigated in the basin of variable depth. Numerical methods are used to analyze marine hazards: historical (storm surges, caused by Cyclone LILI in 2002; volcanic tsunami 2003 on Montserrat) and possible events (possible tsunami of the coast of Martinique). Various data on marine natural disasters are obtained during field surveys (volcanic tsunami in 2003, stonn surges caused by Hurricane Dean in 2007). Designed catalogs of tsunamis and storm surges are created based on results of numerical modeling and field studies; some statistical analysis is perfomed

Dans le cadre du conditionnement des déchets nucléaires, les géopolymères représentent une alternative potentielle aux liants hydrauliques classiques. A ce jour, il est admis que la formation des géopolymères procède selon un mécanisme de dissolution - restructuration - polymérisation conduisant à un matériau solide. Cependant, les liens précis entre la composition de la solution d’activation, le déroulement des réactions de géopolymérisation et la microstructure finale doivent être déterminés du point de vue de la texturation et de l’évolution structurale du matériau. Ainsi plusieurs paramètres de formulation ont été étudiés : la nature de l’activateur alcalin, la concentration en silice et l’ajout d’une source d’aluminium. Il apparait que l’environnement chimique des précurseurs silicatés ou alumino-silicatés est contrôlé par les paramètres de formulation constitutifs de la solution d’activation. Lors de la formation du réseau géopolymérique, ces précurseurs jouent un rôle primordial sur la cinétique de dissolution du métakolin, la taille, l’arrangement et l’agrégation des oligomères alumino-silicatés participant à la formation du réseau poreux. A plus long terme, certaines caractéristiques du réseau poreux qui sont-elles même contrôlées par la taille et l’agencement des oligomères, varient légèrement au cours du temps. Le réarrangement de la structure poreuse associé d’une part à la densification du réseau solide, et d'autre part à la fermeture partielle de la porosité conduit à une légère augmentation de la taille des pores et à une diminution du volume poreux accessible. / In the context of conditioning of nuclear waste, geopolymers represent a potential alternative to conventional hydraulic binders. Currently, it is recognized that the formation of geopolymer proceeds according to a mechanism of dissolution - restructuring - polymerization resulting in a solid material. Despite the availability of many studies to understand these mechanisms, the precise relationship between the chemical nature of the activating solution, the geopolymerization process and the final microstructure should be determined from the point of view of the texturing and the structural evolution of the material. In this work, several parameters were studied: the nature of the alkali activator, the silica concentration and the addition of an aluminum source. It appears that the chemical environment of the silicate or aluminosilicate precursors is controlled by the activating solution composition. During the consolidation of the geopolymer network, these precursors play an important role on the dissolution rate of metakaolin, the size, the rearrange¬ment and the aggregation of aluminosilicate oligomers involved in the porous solid network formation. Subsequently, some characteristics of the porous network which are controlled by the size and the rearrangement of oligomers vary slightly over time. The refinement of the porosity associated to first, a densification of the solid network, and secondly, a partial closure of the porosity at the nanometer scale leads to an increase in the pore size and a decrease of the pore volume.

No description available.

A theoretical study is conducted for the lateral torsional buckling of wooden beam-deck assemblies consisting of twin beams braced by tongue-and-groove decking at the top. Two models are developed, each with a series of analytical and numerical solutions formulated. The first model targets twin-beam-deck assemblies where deck boards and other components are detailed to provide full continuous lateral restraint while the second model is built for situations where the beams are allowed to sway laterally and the relative lateral movement between the beams is partially restrained by the deck boards. In the first model, focus is on wind uplift while in the second model, both gravity and uplift loading scenarios are investigated. In the first model, an energy method is adopted and the principle of stationary potential energy is evoked to formulate closed-form solutions, energy-based solutions and a finite element solution. The validity of the present solutions is verified against a finite element based ABAQUS model. Similarly, a family of solutions is developed under the sway model and verified against the ABAQUS. Parametric studies are conducted for both models to examine the effects of various variables on the buckling capacity. A comparative investigation on the behavioral difference between the two models under ABAQUS is also presented. Overall, the restraining effects of deck boards bracing either on the beam compression or tension side is observed to have a significant influence on the lateral torsional buckling capacity of the twin-beam-deck assemblies.

京都大学 / 新制・課程博士 / 博士(医学) / 甲第23107号 / 医博第4734号 / 新制||医||1051(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 平井 豊博, 教授 湊谷 謙司, 教授 川口 義弥 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

Au cours des dernières années, les exigences croissantes en matière de dissipation thermique à haut rendement pour la microélectronique, les engins spatiaux, les réacteurs nucléaires, etc., encouragent le développement d'échangeurs de chaleur de nouvelle génération. Le caloduc est l’un des équipements de refroidissement efficaces et potentiels. La plupart du transfert de masse et de chaleur se fait au niveau de la micro-région près de la ligne triple de contact (solide, liquide, vapeur), qui est essentielle à l'amélioration de la performance thermique du caloduc. Cette étude se concentre sur le processus d'évaporation de gouttes sessiles de deux nouveaux fluides de travail (solution binaire et nanofluide), qui possèdent une micro-région similaire à celle du caloduc. Le flux de Marangoni induit par le gradient de concentration et la conductivité thermique exceptionnelle devraient améliorer significativement le débit evaporé du mélange alcool-eau et du nanofluide de graphène, respectivement. Une combinaison de techniques acoustiques et infrarouges est développée pour suivre la variation de la concentration d'alcool pendant l'évaporation des gouttes des mélanges 1-butanol-eau et éthanol-eau. Selon l'observation du comportement d'évaporation à différentes températures du substrat, une série d'équations empiriques est suggérée pour prédire le taux d'évaporation de la solution binaire de 1-butanol-eau en considérant l'effet Marangoni thermal et solutal. De plus, l'effet de la PEGylation, de la concentration des nanoparticules et de la température du substrat sur l'évaporation de gouttes de graphène nanofluide est étudié par des méthodes microscopiques, optiques et infrarouges. Les résultats expérimentaux et l'analyse thermodynamique peuvent contribuer à la compréhension complète du mécanisme impliqué concernant les performances d'évaporation du nanofluide de graphène. / In recent years, increasing requirement in high efficient heat dissipation for micro-electronics, spacecraft, nuclear reactors etc., encourage the development of next generation heat exchanger. Heat pipe is one of potential effective cooling equipments and most of mass and heat transfer take place at micro-region near triple phase (solid, liquid, vapor) contact line of working fluid, which is essential to thermal performance improvement of heat pipe. This study focuses on the evaporation process of sessile droplets of two novel working fluids (binary solution and nanofluid), which possess similar micro-region to that in heat pipe. Concentration gradient induced Marangoni flow and exceptional thermal conductivity are expected to significantly enhance evaporation rate of alcohol-water mixture and graphene nanofluid, respectively. A combination of acoustic and infrared techniques is developed to track alcohol concentration variation during evaporation of 1-butanol and ethanol aqueous droplets. According to observation of evaporation behavior at different substrate temperature, a series of empirical equations is suggested to predict evaporation rate of 1-butanol-water binary solution droplet considering thermal and solutal Marangoni effect. In addition, the effect of PEGylation, nanoparticle concentration and substrate temperature on drop evaporation of graphene nanofluid are investigated by microscopic, optical and infrared methods. Experimental results and thermodynamic analysis can contribute to the full understanding of involved mechanism concerning evaporation performance of graphene nanofluid.

Thesis (MEng (Chemical Engineering))--Cape Peninsula University of Technology, 2020 / Continuous growth in the world population has raised significant fears with regards to the sustainability of energy and water resources. Globally, water is an indispensable resource as it is essential for the sustenance of human, animal and plant life. Water is essential for all forms of life and plays a pivotal role in economic growth. The textile industry is one of the greatest consumers of water, it is, therefore, necessary to effectively treat the large amounts of wastewater before discharge to the environment. It is estimated that annually, more than 700,000-tonnes of textile wastewater is produced by the dyeing industry. Textile wastewater is generally characterised by electrolytes, suspended solids, mineral oils and multiple textile dyes, and has therefore been classified as one of the most polluting wastewaters. These dyes are toxic and, in most cases, are not biodegradable. The presence of very small amounts (i.e. < 1 ppm) of dyes in water has aesthetic impacts and is thus undesirable. It is, therefore, necessary to treat textile wastewater before discharging. Currently, membrane technology is widely used for wastewater treatment, as well as water purification. Forward osmosis (FO) is a promising technology for both these applications. FO is characterised by the flow of water through a semipermeable membrane from a feed solution (FS) characterised by the low solute concentration or low osmotic pressure (OP) to a draw solution (DS) characterised by the high solute concentration or high OP, due to the OP gradient across the membrane. The FO process eliminates the need for high hydraulic pressure, as required in traditional membrane technologies, and also has low fouling tendencies. Furthermore, FO has the advantage of lower energy requirements and membrane replacement costs. However, there are still many disadvantages such as reverse solute flux (RSF), membrane fouling, and concentration polarisation (CP) amongst others that still need to be addressed. Therefore, more research needs to be done in light of these limitations to better understand and mitigate these limitations to increase the effectiveness and efficiency of the FO process. This study aimed to evaluate a dye-driven FO system for the reclamation of water from textile wastewater and synthetic brackish water (BW5) by investigating the effects of membrane orientation, system flowrate, change in DS, and membrane fouling on the FO systems performance and energy consumption. The FS used was BW5 with sodium chloride (NaCl) content of 5 g/L whereas Reactive Black 5 (i.e. a reactive dye) and Maxilon Blue GRL (i.e. a basic dye) dyes were used as a DS, respectively. The membrane utilised was a cellulose triacetate (CTA) membrane and was tested in FO mode and pressure retarded osmosis (PRO) mode whilst the system flowrate was adjusted to 400, 500 and 600 mL/min, respectively. Experiments were performed using a bench-scale FO setup which comprised of an FO membrane cell, a double-head variable speed peristaltic pump, a digital scale, two reservoirs for the FS and DS, respectively, a digital multiparameter meter and a digital electrical multimeter to measure system energy consumption. Each experiment comprised of six steps: baseline 1 (membrane control), main experiment (dye-driven FO experiment), baseline 2 (membrane control repeat), membrane cleaning, membrane integrity (membrane damage dye identification) and membrane cleaning (preparation for next experiment). The baseline 1 and baseline 2 experiments operated for 3 h whilst each membrane cleaning procedure operated for 30 min. The main experiments operated for 5 h in the FO mode and 4 h in PRO mode whilst the membrane integrity experiments operated until a minimum of 10 mL water was recovered. Results showed that the PRO mode achieved both higher forward flux (𝐽𝑤) (i.e. 8.87, 8.71 and 9.13 L/m2.h for flowrates of 400, 500 and 600 ml/min) and water recovery (𝑅𝑒) rates compared to FO mode (i.e. 6.60, 6.88 and 7.58 L/m2.h for flowrates of 400, 500 and 600 ml/min). The variation of flowrates had little to no influence on the 𝐽𝑤, 𝐽𝑠 and 𝑅𝑒 of the system. The system consumed less energy in PRO mode (i.e. 381 kWh/m3 average consumption for all three flowrates) than FO mode (i.e. 417 kWh/m3 average consumption for all three flowrates). It was also observed that at a higher DS 𝑂𝑃, the system consumed less energy. Therefore, selecting an optimum initial 𝑂𝑃 is essential for a FO process to minimise the pumping energy. Furthermore, a change in DS from Reactive Black 5 dye to Maxilon Blue GRL dye had no significant impact on the system performance and energy consumption. In this study, no significant membrane fouling was observed, however, minute traces of fouling in the form of foreign functional groups could be observed in the attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) spectrums of the used membranes. Additionally, the observation of negligible changes in baseline 2 (membrane control) Re and Jw results suggested the possible occurrence of membrane fouling during the main experiment (dye-driven FO system).

Ce travail de thèse, réalisé au Laboratoire de Physique de la MatièreCondensée (LPMC), s'inscrit dans le contexte des nouveaux lasers etamplificateurs à fibre optique opérant dans le visible. Cependant, ledéveloppement de telles fibres est limité par des phénomènes tels que le photonoircissement.Cette thèse a été consacrée à l'étude et à la résolution desproblèmes de photo-noircissement des fibres optique de silice dopées àl’aluminium et au thulium, sous pompage optique à 1,07 μm. Au cours de cettethèse, une nouvelle méthode de fabrication spécifique à nos besoins a étédéveloppée et mise en oeuvre au LPMC. Une étude systématique du rôle de laconcentration en thulium dans les mécanismes de photo-noircissement a étémenée. Le rôle du co-dopage avec de l'aluminium, du cérium ou du lanthane aaussi été analysé par des études systématiques. Le photo-noircissement estimputé à la génération de centres colorés par le pompage. Une fois créés, cescentres colorés peuvent être blanchis par la pompe. Un modèlephénoménologique sur la dynamique du photo-noircissement permet dediscuter séparément de la génération et du blanchiment. Au cours de cetravail, il a été montré que l'augmentation de la concentration en thulium et/oula puissance de pompe a pour effet d'améliorer le phénomène de génération. Àl'opposé, l'augmentation de la concentration en aluminium ou en cérium ou enlanthane a pour effet d'améliorer les mécanismes de blanchiment. La mise enévidence et la compréhension de ces mécanismes ouvrent la voie vers desnouveaux lasers et amplificateurs à fibre optique dans le domaine du visible / This thesis, conducted at the Laboratoire de Physique de la Matière Condensée(LPMC), is in the context of new lasers and optical fiber amplifiers operating inthe visible. This wavelength range is currently booming for many applications.However, the development of such fibers are limited by the photo-darkeningphenomenon. This phenomenon consists of the loss of transparency in thematerial during its use under optical pumping. This thesis is devoted to thestudy and the resolution of issues caused by photo-darkening in aluminum- andthulium-doped silica optical fibers when optically pumped at 1.07 μm. In thisthesis, a new method of fiber manufacture that is specific to our needs hasbeen developed and implemented at LPMC. A systematic study of the role ofthulium concentration in the photo-darkening mechanism was conducted. Therole of the co-doping with aluminum, cerium or lanthanum was also analyzedby systematic studies. The photo-darkening is attributed to the generation ofcolor centers by pumping. Once created, these color centers can be bleachedby the pump. A phenomenological model of the dynamics of photo-darkeningallows a separate discussion between the generation and the bleachingphenomena. In this work, it is shown that the increasing of the concentration ofthulium and/or the pump power has the effect of increasing the generationphenomenon. In opposite, increasing of the concentration of aluminum orcerium or lanthanum has the effect to intensify the bleaching mechanism. Theidentification and understanding of these mechanisms open the path to newlasers and optical fiber amplifiers in the visible range

La presente tesis propone una solución tecnológica que automatice el proceso de monitoreo de los planes de acción generados para mejorar la tasa del logro de la competencia de aprendizaje de los estudiantes universitarios, con el objetivo de mejorar el proceso de evaluación por competencias. Nuestra propuesta permite el monitoreo automatizado de los planes de acción gracias a un sistema con características, tales como: (1) registro de los planes a través de formularios con un diseño de experiencia de usuario, (2) visualización y descarga de dashboards personalizados para cada nivel del plan de acción o, en general, con todos los planes de un usuario específico para el análisis y la toma de decisiones, (3) carga y descarga de evidencias sobre el cumplimiento de las acciones de mejora, (4) creación de informes para el seguimiento de planes de acción en formatos apropiados para facilitar la lectura, y (5) envío de notificaciones por correo electrónico sobre cualquier cambio en el plan. La propuesta se describe en dos partes: (1) la automatización del proceso de monitoreo, (2) las funcionalidades de la solución y (3) la arquitectura tecnológica diseñada. Con el fin de validar la propuesta, se desarrolló una encuesta para ser respondida por expertos de calidad educativa en una institución universitaria. Los resultados mostraron que el 93.8 % de los participantes consideran que la solución contribuye a la mejora del logro de las competencias, asimismo se demostró que el monitoreo de los planes de acción se realiza con un 99,6% de mayor eficiencia, lo que facilita su cumplimiento de acuerdo con los parámetros de costo, tiempo e impacto planificado, además, contribuye con la mejora continua de la evaluación basada en competencias. / This paper proposes a technological solution that automates the action plan monitoring process designed to improve the achievement rate of the learning competence on university students, with the objective of improving the process of evaluation by competencies. Our proposal allows the action plan automated monitoring thanks to a system with features, such as: (1) plan registration through forms with a user experience design, (2) custom dashboards display and download for each level of the action plan or, in general, with all the plans of a specific user for analysis and decision making, (3) loading and downloading of evidence on compliance of the improvement actions, (4) report creation for action plan monitoring in appropriate formats to facilitate reading, and (5) email notifications delivery about any changes to the plan. The proposal is described in two parts: (1) the automation of the monitoring process, (2) the solution functionalities and (3) the designed technological architecture. To validate the proposal, a survey was developed to perform it with functional analysts in a university institution. The results showed that 93.8% of the participants consider that the solution contributes to the improvement of the achievement of competencies, it was also demonstrated that the action plan monitoring is carried out with 99.6% more efficiency, which facilitates compliance with the cost, time and planned impact parameters also contributes to the competency-based evaluation continuous improvement. / Tesis