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This work focuses on the propulsion of swimming micro-robots through accessible, quasi-static, fluid-filled, environments of the human body. The operating environment dictates that the system must function under low Reynolds number flow conditions. In this fluidic regime, viscous forces dominate. Inspiration is drawn from biological examples of propulsion systems that exploit the dominance of viscous forces. A system based on the prokaryotic flagella is chosen due to its simplicity; it is essentially a rigid helix that rotates about its base. To eliminate the piercing threat posed by a rigid helix, a propulsion system utilizing a flexible filament is proposed. The filament is designed such that under rotational load, and the resulting viscous drag, it contorts into a helix and provides propulsive force. Four mathematical models are created to investigate the behaviour of the proposed flexible filament. An experimental prototype of the flexible tail is built for similar purposes. An experimental rigid tail is also built to serve as a benchmark. The experimental results for propulsive force generated by the rigid tail match the Resistive-Force Theory (RFT) model. An analysis of the system concludes that experimental error is likely minor. An ADAMS model of the rigid tail, as a result of modelling error, under-predicts the propulsive force. The experimental flexible filament shows that the proposed propulsion system is feasible. When actuated, the tail contorts into a `helix-like' shape and generates propulsive force. An ADAMS model of an ideal flexible filament shows that, if a complete helix is formed, there is no loss in performance when compared to a rigid counterpart. The experimental filament is too stiff to form a complete helix and, accordingly, the ADAMS model does not simulate the filament well. To decrease this discrepancy, a second ADAMS model, attempting to directly simulate the experimental filament, rather than an ideal one, is created. Regardless, the second ADAMS model gives confidence that a multi-body dynamic model using lumped-parameter drag forces, after further modifications, can simulate the experimental flexible filament well.

Here I present results from three field studies and one manipulative experiment that explored some of the factors that may influence belowground communities at multiple spatial scales. In the first field study I found that the abundance of two groups of soil mites was positively related to soil pore volume in two contrasting habitats. Hence, by limiting abundance, soil pore volume could indirectly influence species richness of mites. In another field study, using a spatial design, I found that the variation in community composition of soil mites and microbes within habitats was related to the variation in soil properties and plant community composition. However, the relative influence of these factors depended on the degree to which they varied within a habitat. Similarly, using a multi-site field study I found that soil properties, plant community composition and also precipitation influenced the composition of the microbial and mite communities within the landscape. This study also showed that the species richness of soil mites within a site was related to the degree of variation in soil properties and vegetation within the site. Finally, a manipulative field experiment showed that species richness of soil fauna was related to small-scale heterogeneity in soil physical properties, and that both the abundance and composition of belowground communities was related to the organic horizon thickness. Overall, my work shows a general positive relationship between species richness of soil biota and heterogeneity across spatial scales, and that the composition of belowground communities is related to the variation in soil properties, plant community composition and climate.

This study was designed to show what dissemules may be carried by selected genera of Odonata, where the dissemules may be predominantly carried on the selected insects and to relate the behavior of the selected Odonata to frequency of occurrence of micro-organisms on the insects.

This thesis report demonstrates a process of designing a control system for a low-cost micro-manipulator fabricated through 3D printing technique. A 3D printed micro-manipulator easily suffers from the problems of unexpected and non-uniform output motions, so a control system is designed to mitigate the external disturbance and improve the output precision of output motions, operation complexity, and motion capability. The overall design process consists of mechanical fabrication, control system design and experimental validations. From the results of validations tests, the 3D printed micro-manipulator is able to generate three dimensional(X, Y, and Z) motorized movements with the travel range at 38mm in each dimension. Also, it can provide an adjustable output resolution based on different parameter settings in the control system. The minimum step size can reach to 0.76 µm/step. The suggested step size is 2µm/step due to the limitation of perception resolution. The average output precision of the output motion is bounded within 5 µm in the validation tests. In order to improve the user experiences, the suitable operation speed for each dimension ranges from 25 to 50 µm/s. Users can easily control the 3D printed micro-manipulator to do some simple micro-manipulation tasks by manipulating micro-samples through teleoperated or semi-autonomous control provided in the control system. The parts used to build the micro-manipulator are common, off-the-shelf, or 3D printed, so users can easily do the maintenance or repairs on the 3D printed micro-manipulator.<br>

Le marché des microcontrôleurs est en pleine mutation et devrait croitre propulsé par le développement de l’Internet des objets. La puissance de calcul, la connectivité, les performances des périphériques et l’efficacité énergétique sont les facteurs clés de ce développement. Le module de gestion de l’alimentation est entièrement intégré au sein même du microcontrôleur lui permettant de fonctionner avec uniquement quelques composants passifs. Ce module doit assurer le maintien de la tension d’alimentation indépendamment de la consommation du microcontrôleur qui augmente avec la puissance de calcul. L’architecture choisie doit également optimiser le rendement selon la consommation du microcontrôleur sans impacter le fonctionnement de blocs sensibles. L’intégration de l’étage de puissance d’une alimentation à découpage engendre du bruit de commutation ayant un impact sur les fonctions analogiques du circuit. L’objectif de ce travail est l’analyse de la génération du bruit par l’étage de puissance et sa propagation au sein du circuit complexe. Le modèle de génération du bruit est constitué de circuits RLC équivalents. Les expressions des R, L et du C sont exprimées dans chaque état de l’étage de puissance en fonction des composants parasites du système. Ces modèles permettent de comprendre le mécanisme de génération du bruit et de donner une estimation de l’amplitude et de la fréquence des résonances. L’ensemble du système c’est-à-dire le circuit, le boitier et la carte électroniques, est modélisé pour extraire les chemins de propagation entre l’alimentation à découpage et les cellules sensibles du système. Ces modèles sont vérifiés en mesurant un circuit de test. Finalement trois solutions sont proposées pour réduire l’impact du bruit de l’alimentation à découpage : deux changements dans l’architecture de l’étage de puissance pour réduire la génération du bruit et une modification des interconnexions globales du circuit pour améliorer l’isolation entre les différentes parties du système. Cette thèse présente une méthodologie originale pour construire un modèle au niveau système de la génération et de la propagation du bruit de commutation. Les connaissances acquises ont été vérifiées expérimentalement et appuyées par la conception d’un démonstrateur (qui doit être testé). / The micro-controller market is undergoing changes and is expected to grow quickly promoted by the Internet-of-Things (IoT) development. Calculation capability, connectivity, analog performances and power efficiency are key enablers. Power management unit is co-integrated with the micro-controller so that only few off-chip passive components are necessary. The embedded power management unit must deliver the micro-controller input voltage along with the power demand which increases with the computation capability. The chosen architecture has to optimize the efficiency in high and low power mode but without impacting analog performance of sensitive IPs (Intellectual Property). The active part of an inductive buck converter is integrated but some switching noise is observed that severely impact analog IPs. The objective of this work is the analysis of the noise generation from the power stage and its propagation in the System-on-Chip (SoC). The generation model is constituted of a RLC equivalent circuits in each state of the power stage. The R, L and C expressions are detailed depending on physical parasitic components. These models permit to understand noise mechanisms and to give an estimation of the noise amplitude and frequency resonance. The models show the degrees of freedom to manage the noise signature. The whole system, i.e. the electronic board, the package and the chip, is modeled to extract the system-level propagation path between the buck converter and sensitive IPs. These models are verified by measurement on a test vehicle. Finally three solutions are presented to reduce the buck converter noise impact: two changes in the power stage architecture to reduce noise generation and one modification of the top routing of the power delivery network to improve isolation between parts of the circuit regarding noise susceptibility. The thesis contributes an original methodology to build the missing models at system-level regarding noise generation and propagation from the switching power supply. Knowledge has been acquired, experimentally verified and supported by the design of a demonstrator (to be tested).

Orientador: Nelson Horacio Pezoa Garcia / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de Alimentos / Made available in DSpace on 2018-07-23T07:24:45Z (GMT). No. of bitstreams: 1 GilabertEscriva_MariaVictoria_M.pdf: 2902847 bytes, checksum: 9437b7cb28e89a7cba49e16a8e730251 (MD5) Previous issue date: 1997 / Resumo: O processo de torração é fundamental para a obtenção das características de qualidade do cacau. Quando torradas convencionalmente, as amêndoas de cacau produzem uma massa ("líquor") desuniforme, devido ao elevado gradiente de temperaturas entre o centro e a parte externa, deixando o interior cru ou a parte externa excessivamente torrada. Esta foi a causa do desenvolvimento da torração em fragmentos ("nibs") e das tentativas de torração do "líquor". Porém, estas técnicas amplamente difundidas precisam de várias etapas prévias, que encarecem o processo. Neste trabalho foi testada a torração por microondas, numa tentativa de diminuir o gradiente de temperaturas na amêndoa, aplicando um tratamento térmico mais uniforme. Este tipo de aquecimento difere do tradicional porque as ondas penetram no produto uniformemente, aquecendo-o não por convecção ou condução, como é o caso da torração convencional. O objetivo deste estudo foi comparar estes dois tipos de torração de cacau: convencional, em forno elétrico rotativo de regime intermitente, e por microondas, em protótipo de forno rotativo contínuo por microondas (2450MHz). O cacau foi torrado tanto em amêndoas inteiras quanto fragmentadas em "nibs", para determinar a possibilidade de obter um produto uniforme através da torração em amêndoas inteiras usando a energia das microondas e os parâmetros mais adequados de tempo e potência requeridos. As amêndoas originárias do estado do Pará, foram caracterizadas quantitativamente através da composição centesimal e porcentagem de componentes e qualitativamente através do teste de corte. A variável do tratamento por microondas foi a densidade de potência aplicada tanto às amêndoas inteiras (254,45 a 290,80 Wh/kg) quanto aos "nibs" (227,27 a 262,23 Wh/kg), com tempo de residência do produto no cilindro constante (10 min.). O tratamento convencional teve como variável o tempo de torração das amêndoas (40 a 44 min) e dos "nibs" (34 a 38 min), enquanto a temperatura da camisa do forno era mantida a 150°C. Após a torração, um total de 12 amostras foram moídas em moinho de rolos resfriados com a finalidade de obter o ¿líquor". Foram feitas análises de gordura, umidade e tamanho de partícula de cada amostra. A comparação das amostras foi feita em termos de viscosidade, que é uma propriedade muito importante da massa de cacau, já que influencia tanto o seu uso final quanto a definição dimensional de equipamentos (tubulações, bombas). A viscosidade foi medida em reômetro Brookfield (mod. RV-DVIII), de cilindros concêntricos (adaptador de pequenas amostras), com temperatura controlada, mediante um programa baseado na bibliografia, com a finalidade de obter medidas e resultados os mais homogêneos possíveis. A viscosidade plástica das amostras torradas em microondas foi, em geral, menor que a daquelas torradas em forno elétrico rotativo. A das amostras torradas em fragmentos ("nibs") também foi menor que a daquelas torradas em amêndoas inteiras quando torradas em forno elétrico. Quando o tratamento foi por microondas, a viscosidade das amostras obtidas de amêndoas torradas inteiras foi menor que a das amostras torradas em "nibs". ¬A análise sensorial realizada com três especialistas mostrou que o sabor das amostras torradas em microondas foi similar ao do "líquor" obtido da torração convencional, apresentando como vantagem a redução de tempo deste novo processo. Os resultados obtidos, pioneiros nesta área, podem ser considerados positivos pois o fato de as amostras torradas em microondas serem menos viscosas pode favorecer o manuseio do "líquor" e representar uma redução na quantidade de manteiga de cacau a ser adicionada no processo de fabricação do chocolate, o que representa uma vantagem econômica. Também pode ser destacado o fato de que a torração de amêndoas em microondas (3200 kW ou 290,80 Wh/kg), apresentou um produto uniforme e de boas características sensoriais, sem precisar de nenhum tratamento prévio / Abstract: The cocoa roasting process is of fundamental importance in producing the quality characteristics of cocoa. When conventionally roasted, cocoa beans produce a non-uniform cocoa-mass (Liquor) due to the considerable differential in temperature between the surface and the core of the bean, leaving the latter raw or the former excessively roasted. To avoid this, a new roasting procedure was developed using either nibs (peeled and broken beans) or liquor (cocoa mass). However, these widely divulged techniques require preliminary stages which make the treatment more expensive. In this work, microwave roasting was tested, attempting to reduce the temperature gradient in the cocoa bean by using a more uniform heating treatment. Microwave heating differs from traditional methods because the waves penetrate the product uniformly, not heating either by conduction or by convection, as is the case in conventional roasting. The objective of this study was to compare the microwave continuous roasting process (2450MHz) with the conventional batch method, evaluating the efficiency of the use of microwaves in the roasting of whole beans and nibs, and also determining the ideal time-energy combinations for the roasting of cocoa by microwaves. Treated beans from the state of Pará were quantitatively analysed to determine the proximate composition of the raw material and also qualitatively analysed (cut test). The variable used in the microwave treatment was the power density applied to the whole beans (254,45 a 290,80 Wh/kg) and to the nibs (227,27 a 262,23 Wh/kg), with a constant residence time of 10 minutes. The process was undertaken in a prototype of a continuous rotary cylindrical microwave oven. The variable used in the conventional roasting process was the roasting time of the beans (40 to 44 min.) and the nibs (34 to 38 min). This process was carried out at a constant temperature of 150°C in a rotary electric oven. After roasting, 12 samples were ground in a refrigerated cylinder mill to obtain the liquor. The fat content, moisture and particle size were determined in each sample. The samples were compared with respect to viscosity, which is a very important property of the liquor, since it determines both its final use and the size definition of equipments like pipes and pumps. The viscosity was measured in a Brookfield rheometer (mod RV-DVIII) with two concentric cylinders (small sample adapter), and controlled temperature, using a program based on the literature aimed at obtaining the most homogenous results possible. In general, the plastic viscosity of the microwaved samples was lower than that of the conventional roasted samples. Also the nibs showed lower viscosities than the whole beans when roasted in the electric oven. The viscosity of the samples roasted in the microwave oven was lower in the whole beans than in the nibs. The product was sensorially evaluated by three experts in cocoa flavour, and it was shown that the flavour of the microwave roasted products was similar to that of the conventionally roasted products with the advantage of a reduction in process time. These results are pioneer in this area and can be considered positive because low viscosity would improve the handling of the liquor and result in a reduction in cocoa butter addition in chocolate production, improving the economy of the process Roasting of whole beans by microwaves offered a uniform and good flavoured product (A3200), and no pretreatment was required / Mestrado / Mestre em Tecnologia de Alimentos

Orientador: Jonas Contiero / Banca: Cassiana Maria Reganhan Coneglian / Banca: Elisabeth Loshchagin Pizzolitto / Resumo: A cepa bacteriana Pseudomonas aeruginosa LBI, isolada de solo contaminado com hidrocarbonetos, foi inoculada visando promover a degradação dos hidrocarbonetos através da capacidade de produção de biossurfactantes. Como matéria prima alternativa de baixo custo para produção biossurfactantes utilizou-se a borra oleosa proveniente do fundo de tanques de estocagem da REPLAN-PETROBRAS. Os ensaios foram realizados em triplicatas a 30C, 200 rpm, durante 168 horas e o acompanhamento foi realizado por amostra a cada 24 horas para quantificar o biossurfactantes e o crescimento celular. A tensão superficial, PH e os estudos de estabilidade e emulsificação foram realizados com o sobrenadante do cultivo de 168 horas. A cepa bacteriana mostrou-se capaz de se desenvolver e produzir biossurfactantes em querosene, óleo diesel, petróleo e borra oleosa. Apenas benzeno e tolueno não apresentam resultados positivos / Abstract: Pseudomonas aeruginosa LBI isolated from hydrocarbon contaminated soil and potential producer of biosurfactant was used for hydrocarbon biodegradation. The petroleum waste from REPLAN-PETROBRAS, alternative source of low cost to biosurfactante synthesis was utilized on medium culture. These studies were done at 30C with shaking at 200 rpm, during 168 hours, in triplicate. The samples were withdrawn daily for growth studies and biosurfactante production. The surface tension, PH and stability studies were done with the cell-free broth after 168 hours of incubation. The strain was able to produce biosurfactantes and to grow on the analyzed carbon sources, except benzene and toluene. When cultivated on diesel oil 30%, the strain produced higher quantities of biosurfactante. The biosurfactante was able to emulsifier all analyzed hidrocarbons. Stability studies of the product on the culture broth indicate that the biosurfactante is stable in extreme conditions. Therefore the strain Pseudomonas aeruginosas LBI and the biosurfactante produced have potential applications in bioremediation of site hydrocarbon contaminated, and possible application in enhanced oil recuperation / Mestre

Cette thèse est une étude micro-économétrique qui a pour objet d’étudier la relation entre l’innovation, le commerce électronique et la productivité. Au de là de cet objectif, ce travail a pour but d’identifier la structure des entreprises qui pratiquent la vente enligne. La présente thèse est composée essentiellement de trois études dans lesquelles on exploite des données statistiques qui concernent des entreprises françaises de toute taille (les micro, petites, moyennes et grandes). Les bases de données ont été construites à partir des enquêtes TIC et commerce électronique, CIS, R&D et FARE. L’enquête FARE fournit des statistiques financières supplémentaires. La première étude vise à déterminer l’impact du e-commerce sur la productivité en utilisant un panel de données de 2008 à 2012. Les données sont analysées en utilisant la fonction de production de Cobb-Douglas. Les résultats montrent que le e-commerce a un impact positif et significatif sur la productivité au cours de cette période. Ainsi, l’e-commerce contribue à promouvoir la productivité des entreprises françaises. La deuxième étude vise à comprendre les motivations qui poussent les micro-entreprises à adopter la vente en ligne et à évaluer leur productivité. Dans cette étude, on utilise la méthode du Propensity Score Matching. Pour évaluer les différences de productivité entre, d’une part les micro-entreprises qui pratiquent la vente en ligne et, d’autre part, celles qui n’utilisent pas l’outil du e-commerce pour l’année 2012. Les résultats démontrent que le chiffre d’affaire généré parles micro-entreprises pratiquant la vente en ligne est plus élevé, et ces dernières affichent une meilleure productivité en comparaison avec les entreprises que ne la pratique pas. Le troisième objectif est de déterminer l’impact de la R&D et de l’innovation en matière de TIC, plus particulièrement l’e-commerce, sur la performance des entreprises française en2008. Une variante du modèle CDM (Crépon, Duguet et Mairesse) est appliquée. Cette étude décrit le lien entre les dépenses R&D, e-commerce, l’innovation et la productivité. Les résultats montrent que la R&D est un facteur important de l’innovation, et le capital TIC est aussi un facteur clé pour le e-commerce. En outre, bien que ces deux facteurs (l’output de la R&D précisément les innovations technologiques de produits /procédés et le commerce électronique), affectent positivement la productivité, l’impact positif est plus marqué pour l’innovation. / This thesis is a micro-econometric investigation into the relationship between innovation, e-commerce, and productivity, as well as an establishment of the structure of e-selling firms. It is composed of three main investigations using micro, small, medium and large datasets from French firms. The datasets are created by merging the ICT & e-commerce survey, CIS, R&D, and FARE. FARE survey is used to provide additional financial statistics. The first investigation aims to identify the impact of e-commerce on productivity using panel datasets from 2008 to 2012. The data is analyzed using a Cobb-Douglas production function including physical capital and labor input. The findings show that e-commerce has a positive and significant impact on productivity during this period of time. E-commerce does contribute in promoting productivity for French firms. Secondly, it aims to understand the motives behind micro firms inadopting e-selling activities, and to assess their productivity. This investigation uses propensity score method to obtain matched samples to estimate the treatment effect on the treated ; in other words we evaluate productivity differences between e-selling micro firms and non e-selling micro firms for the year 2012. The findings imply thate-selling micro firms have a higher turnover and higher productivity compared to the ones that do not sell online. The third aim is to determine the impact of R&D and ICT innovations, more particularly e-commerce, on firm performance after its application for the year 2008. A variant of the CDM model (Crepon, Duguet and Mairesse) is applied. It describes the link between R&D expenditure, e-commerce, innovation, and productivity.The results show that R&D is an important enabler of innovation, and ICT capital is also a key enabler for e-commerce. In addition, both, R&D output (precisely technological innovation which are product and process innovation) and e-commerce, have a positive influence on productivity; while R&D reveals a greater productivity effect.

1v. (various paging) : / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (D.Sc.1976) from the Dept. of Geology, University of Adelaide