Chemical and electrochemical methods for depositing platinum microparticles at the membrane-electrode interface of solid polymer fuel cell oxygen reduction electrodes have been developed and studied.

Innovative newly qualified graduates need to proof themselves to the world through their God-given talents and ideas and can only really put their name on the map by starting their own company. Graduates being compelled to join a company to attain, over a number of years, the necessary capital investment and business skills, cannot flourish and reach their full potential whilst being overshadowed by the company. There is a need for an interface between the university and the industry, a middle ground and an incubator where newly graduates can be nurtured into maturity in order to be independent. An opportunity for innovative entrepreneurs to start his/her own company by providing them with the necessary services and conveniences, immediate and grand exposure as well as training in the field of business management. Lynnwood Road as the front facade of the University of Pretoria, forms the visual interface with the public sector. Lynnwood Road is a narrative journey describing the translating of information being offered by the University of Pretoria. This narrative is formed in each person's own thoughts driving along Lynnwood Road, but the narrative is incomplete as it is without a conclusion. There isn't a building that serves as an exhibition space for the university to display the products and innovations that comes from absorbing years of information at the University of Pretoria. / Dissertation (MArch(Prof))--University of Pretoria, 2009. / Architecture / unrestricted

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The conflict between stability and curving has been well documented since the dawn of the railways. Advances in computer technology and deeper understanding of the complex mechanics of the wheel-rail interface have led to the study of innovative designs. This thesis outlines the need for steering systems for railway applications. A number of innovative passive solutions have been proposed to reduce the conflict between stability and curving. Comparisons of some of these solutions show that significant benefits can be obtained by using uncommon configurations.

The main aim of this paper is to analyse the user interface of current school information system and to redesign new interface based on user testing results. The assumption for reaching this goal is the necessary knowledge of principles of designing modern user interfaces. The benefit consists in creating a whole new structure of navigation system and in the redesigning layouts. The beginning part of this work presents value of usability user interface and who is designing and testing it. The following part describes principles of modern user interfaces. Conclusion part of this paper presents a case study, which describes the problems of current user interface of the ISIS and the new solution of user interface ISIS and its navigation system.

La microchirurgie de l’oreille moyenne requiert une forte dextérité en raison de la finesse et de l’extrême sensibilité des structures impliquées. L’apprentissage de cette chirurgie est délicat et est effectué en fin d’internat. Ce travail porte sur le développement d’un modèle mécanique en éléments finis des différentes structures qui composent l’oreille moyenne dans le but de concevoir un simulateur chirurgical. Les objectifs sont de fournir un outil polyvalent pour l’apprentissage et l’entraînement de la chirurgie par la chirurgie, ainsi que d’offrir la possibilité d’explorer et d’évaluer de nouvelles procédures chirurgicales liées à l’apport de nouvelles technologies telles que la robotique. Le comportement mécanique du modèle développé a été confronté avec succès aux observations réalisées sur des pièces anatomiques. Afin d’obtenir un outil de simulation qui tienne compte des différences anatomiques de chaque patient, une méthode de déformation de l’atlas mécanique basée sur l’imagerie clinique a été implémentée. Les simulations du fraisage de la platine de l’étrier ainsi que le placement d’une prothèse ossiculaire ont été réalisées à l’aide d’une interface haptique et d’une nouvelle approche du rendu. Ce travail constitue ainsi le premier simulateur virtuel de chirurgie de l’oreille moyenne. Enfin le robot télé-opéré, RobOtol, a été intégré au simulateur afin d’étudier de nouvelles procédures chirurgicales robotisées. Le travail effectué porte essentiellement sur la simulation interactive réaliste de procédures chirurgicales complexes ainsi que la formation et la robotisation de la microchirurgie otologique. / Microsurgery of the middle ear requires high dexterity due to the finesse and the extreme sensitivity of the structures involved. Learning this surgery is delicate and is performed at the end of the residency. This work focuses on the development of a mechanical finite element model of the anatomical structures that compose the middle ear in order to design a surgical simulator. The objectives are to provide a versatile tool for learning and training of the surgery by surgical practice, as well as the opportunity to explore and evaluate new surgical procedures related to new technologies such as robotics. The mechanical behavior of the developed model was successfully confronted with observations on human specimens. In order to obtain a simulation tool that takes into account the anatomical differences of each patient, a deformation approach of our mechanical atlas, based on clinical imaging, was implemented. Simulations of the stapes footplate drilling and the placement of an ossicular prosthesis were performed using a haptic interface and a novel rendering approach. This work is thus the first virtual simulator of the middle ear surgery. Finally the tele-operated robot, called RobOtol was incorporate in the simulator to explore new robot-based surgical procedures. In addition, the simulation allows to train the otologists to the use of the robot. This work concerns mainly on the interactive simulation of complex surgical procedures, as well as on the learning and the robotization of the otologic microsurgery.

Orientador: Armando Turtelli Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Fisica Gleb Wataghin / Made available in DSpace on 2018-07-17T12:07:19Z (GMT). No. of bitstreams: 1 Vieira_SibeliusLellis_M.pdf: 2859885 bytes, checksum: 660982846a7ffabc5e196f9c7e4b4e5f (MD5) Previous issue date: 1987 / Resumo: Apresentamos neste trabalho um sistema de automatização de medidas em fotodensitometria microscópica. Basicamente, tais medidas se constituem em quantificar as relações entre a Intensidade de um feixe transmitindo a relação à Intensidade do feixe incidente em filmes de Raio-X. No processo de automatização, implementamos o hardware e o software de uma Interface inteligente, baseada no microprocessador Z80, cujo objetivo é controlar a aquisição de dados do Fotomicrodensitômetro. Além de controlar a aquisição e transmissão de dados, a Interface é responsável pelo comando do Motor de Passo acoplado ao equipamento. Tal sistema facilita a análise de dados dos filmes de Raio-X, bem como proporciona melhor resolução e confiabilidade às medidas / Abstract: Not informed. / Mestrado / Física / Mestre em Física

This study examines how the Delta-bluffs interface in the Mississippi River alluvial flood plain of western Mississippi affects the spatial variation of tornado occurrence and the characteristics of tornadoes that occur within fifty km of the interface. A t-test and Poisson distribution were used to test for clustering of tornadoes along the Delta-bluffs interface. Previous research has been used to show differing vegetation and soil types can act as focusing mechanisms for thunderstorm development and enhancement. An in-depth analysis of eight tornado events reveals the Delta-bluffs interface enhanced reflectivity and velocity values whenmseven of eight of the storms were within twenty km of the topographic boundary. It was also shown that changes in the roughness of the Earth’s surface can affect the SRH being ingested by a thunderstorm. It was found that F0-F1 tornadoes are significantly (p < 0.01) clustered along the interface but F2-F5 tornadoes were not significantly (p < 0.05) clustered along this boundary. It appears unlikely that characteristics of tornadoes within and outside of the Delta are statistically different.

[pt] O desenvolvimento de interfaces gráficas baseadas na manipulação direta de objetos da aplicação representados em um canvas é uma tarefa complexa que encontra pouco suporte de desenvolvimento nas tecnologias de programação atuais. Grafos dirigidos na forma de diagramas esquemáticos são usados em programas de supervisão, controle e simulações de gerenciamento de energia elétrica, em automações industriais e diversos outros sistemas semelhantes em que o processo é representado por uma série de componentes interconectados. São inúmeras as aplicações baseadas nestes tipos de objetos, a ponto de merecerem ferramentas especiais para o seu desenvolvimento. Este trabalho propõe uma arquitetura para o desenvolvimento de interfaces gráficas baseadas em grafos que permita ao usuário a criação e instanciação de equipamentos com atributos e comportamentos dependentes da aplicação, com um alto grau de abstração. Como ferramenta para o desenvolvimento de aplicações sob a arquitetura proposta, foi implementada uma biblioteca de objetos gráficos com suporte à informação de grafo subentendido nos diagramas. O objetivo principal da arquitetura é permitir que o programador se concentre no desenvolvimento da aplicação, abstraindo-se das questões relacionadas com a interface. Esta arquitetura foi validada através de protótipos de aplicações industriais reais.

Despite the staggering volume of work in the open literature on primary and secondary atomization, there is nothing known that addresses the mechanisms for, and injector geometry implications for, primary atomization within a self-sustained pulsating transonic three-stream injector. Thus, a computational effort involving 86 simulations, including multiple validation exercises, has been executed in order to develop a numerical foundation and then study the effects of nozzle geometry, numerical methodology, grid resolution, modeled domain extent, feed rates, feed flow modulation, feed flow swirl, feed materials, and operating conditions. This is the first undertaking ever reported to disclose the intense details of transonic pulsating flows within the three-stream injector. Metrics for assessment of acoustics and temporal spray character were numerous. Frequency responses among those metrics implied a common pulsation-driving mechanism. It has been discovered that liquid bridging with the production of a liquid fountain and shocklet-like structures in the retracted (pre-filming) zone, along with localized gas-liquid normal pressure gradients, are responsible for bulk pulsations. These findings were never reported in the literature, thus represent an important contribution of this study. Unexpectedly, a new trend for temporal mean droplet size, when normalized by distance from the nozzle, versus distance from the nozzle has been found, which took a common form among all geometries and feed materials tested. Therefore, there is some value to simulate air-water flows, first, to scope general parameters and characteristics, before modeling more computationally challenging slurry flows. This represents an additional contribution of this work not previously reported in the literature. Newly unveiled strong interactions between feed materials, geometry, and feed rate were discovered. Various combinations of inner nozzle retraction and slurry annular thickness were shown to be advantageous, depending on the goals of the injection system. The importance of either geometry variable for three-stream injectors has not been quantified until now. The predictive power of various modeling frameworks has been assessed for the first time. Axi-symmetric (AS) simulations can successfully predict absolute acoustic details; remarkably and surprisingly, AS simulations can also be used for directional indicators of bulk droplet size. This is an especially powerful revelation given the massive reduction in computational requirements for AS models. Reduced order 3-D models are required for better droplet size estimates. A relatively simple eddy-viscosity turbulent model seems to be adequate for predicting droplet sizes for three-stream injectors, in which the primary energy source is bulk pulsations. For larger two-stream systems (atomization energy is sourced in local shear layer instability development), however, a state-of-the-art hybrid model (newly implemented for this effort) appeared to be necessary to capture the resulting droplet scales. Lastly, droplet size and characteristic flow length scale predictions for two open literature non-Newtonian liquid atomizers were made available. / Ph. D.