L’optimisation de l’incorporation et de la libération de principes actifs dans les produits formulés constitue un des enjeux majeurs des industries pharmaceutiques et cosmétiques. L'objectif principal de notre étude est de proposer un modèle prédictif de la diffusion de petites sondes au sein des émulsions concentrées. Pour cela, il a fallu considérer à la fois la formulation d’émulsions concentrées stables et leur caractérisation rhéologique et structurelle ainsi que la prédiction des paramètres de transfert des sondes au sein des émulsions concentrées. On entend par paramètres de transfert, tous les paramètres permettant de caractériser les différents mécanismes de transfert de sondes dans les émulsions concentrées pris en compte dans notre système, à savoir le coefficient de diffusion dans les phases continue et dispersée, le coefficient de transfert à l’interface eau/huile, le coefficient de partage à l’équilibre de la sonde entre les deux phases de l’émulsion. Une nouvelle approche de caractérisation de la structure des émulsions concentrée a permis l’obtention des paramètres importants de structure (taille des gouttes et épaisseur du film de la phase continue). L’étude détaillée des mécanismes et processus diffusionnels est réalisée avec la prise en compte des résultats liés à la caractérisation structurelle du système d’étude. Ainsi, un modèle de diffusion fondé sur une approche phénoménologique est proposé pour prédire l'évolution des profils de concentration de la sonde dans les émulsions concentrées. Les cinétiques expérimentales de libération des sondes sont comparables à celles simulées par le modèle sans paramètres ajustables. Cette comparaison montre une bonne adéquation entre le modèle de diffusion et l’expérience / In the field of controlled release technology for new drugs, models that can predict its delivery during application are important for device design. The main objective of this work is to develop a predictive model able to describe the drug delivery from highly concentrated water-in-oil emulsions. These systems consist of deformed droplets dispersed in a continuous film. Their structure’s characteristics make them favourable for their use as releasing devices. A combination of different transfer mechanisms has been implemented in a mathematical model in order to simulate release experiments under different operating conditions (volume fraction, oil/surfactant ratio). A sensitivity analysis has been performed to point out the most relevant parameters affecting the drug’s release: drug partition and diffusion coefficients. Partition coefficient of the drug for different surfactant concentrations has been obtained through a predictive thermodynamic model UNIFAC, and the diffusion coefficient using Chang and Wilke equations in addition to the Stefan- Maxwell development. An original and simple technique has been used to determine indirectly the mean droplet size of the concentrated emulsions, through measurements of continuous phase’s thickness by analysis of incoherent polarized steady light transport through emulsion samples. In a general view, the diffusion model proposed for small drug diffusion in concentrated emulsions, which was first proposed for diluted emulsions, predicts successfully the evolution of mandelic acid concentrations during release experiments undertaken in perfect sink conditions

Bien que les matériaux poreux soient nombreux dans la nature, la synthèse en laboratoirede matériaux présentant une porosité multi-échelle ou hiérarchisée est toujours délicate. Enutilisant la matière molle (émulsions concentrées, auto-assemblages, mésophases lyotropes, etc)et le procédé sol-gel, il est possible d’obtenir une grande variété de matériaux monolithiques, àporosité hiérarchisée, composés d’un squelette silicique. La porosité de ces matériaux peut êtreoptimisée en jouant avec la nature de l’émulsion, le tensioactif utilisé, ou avec l’ajout d’agentd’extérieur comme le sel. En combinant ces méthodes, des matériaux possédant une mésoporositéhexagonale ont été obtenus. Grâce à leur surface riche en silanols, ces matériaux poreux ont étéfonctionnalisés par greffage post-synthèse de molécules organiques. Dès lors, l’immobilisationd’entités biologiques comme les enzymes au sein de la structure poreuse a permis d’utiliser cesmatériaux pour des réactions d’hydrolyse, de synthèse ou de décoloration en milieu aqueux dansune approche de « chimie verte ». Enfin, des micro-organismes ont été piégés dans ces matériauxporeux qui ont été recouverts d’une coque en silice. Les micro-organismes peuvent s’y développersans restriction et leur croissance est très différente de celle observée dans les cultures classiques.La coque en silice, formée en surface, est donc imperméable au passage des bactéries (taillemicrométrique) mais perméable à la diffusion des substrats et des réactifs. Cette diffusion a étémise à profit pour réaliser des réactions enzymatiques en cascade. Ces matériaux se positionnentcomme des biocatalyseurs très prometteurs pour de nombreuses applications. / Although porous materials are numerous in nature, the laboratory synthesis of materials withmulti-scale or hierarchical porosity is always difficult. By using soft matter (concentrated emulsions,self-assemblies, lyotropic mesophases, etc.) and the sol-gel process, it is possible to obtaina wide variety of monolithic materials with hierarchical porosity composed of a silicic skeleton.The porosity of these materials can be optimized by playing with the nature of the emulsion,the surfactant used, or with the addition of external agents such as salt. By combining these methods,materials with hexagonal mesoporosity have been obtained. Thanks to their silanol-richsurface, these porous materials have been functionalized by post-synthesis grafting of organicmolecules. Therefore, the immobilization of biological entities such as enzymes within the porousstructure has made it possible to use these materials for hydrolysis, synthesis or discolorationreactions in aqueous media in a "green chemistry" approach. Finally, microorganisms were trappedin these porous materials which were covered with a silica shell. Microorganisms can growthere without restriction and their growth is very different from that observed in conventionalcultures. The silica shell formed on the surface is therefore impermeable to the passage of bacteria(micrometric size) but permeable to diffusion of substrates and reagents. This diffusion wasused to carry out cascade enzymatic reactions. These materials are positioned as very promisingbiocatalysts for many applications.

La situation énergétique actuelle impose le développement de technologies qui utilisent des énergies renouvelables pour limiter la dépendance aux ressources fossiles et diminuer l’impact de l’activité humaine sur le changement climatique. Parmi ces technologies, le solaire thermodynamique utilise l’énergie solaire pour chauffer un absorbeur, l’énergie de cet absorbeur étant alors convertie en électricité à travers un cycle thermodynamique classique. L’amélioration des performances de cette technologie passe par la conception d’absorbeurs capables de fonctionner efficacement à haute température. Dans ce travail de thèse, nous explorons deux voies différentes dans ce but.La première est basée sur la conception de structures multicouches optimisées par algorithme génétique. Nous montrons que ces structures permettent d’obtenir un rendement supérieur à 80 %, valeur très proche des limites fondamentales, démontrant ainsi leur fort potentiel pour le solaire thermodynamique.La seconde voie est basée sur l’optimisation des interactions électromagnétiques dans des structures plasmoniques à base de nanoparticules métalliques. Ces structures sont le siège d’effets coopératifs qui peuvent exalter très fortement les pertes dans la structure. Ces mécanismes sont mis à profit pour concevoir des absorbeurs à base de réseaux binaires de nanoparticules d’or et d’argent dispersées dans une matrice transparente. / The current energy situation requires the development of technologies that use renewable energy sources to reduce the dependence on fossil fuels and the impact of human activity on climate change. Among these technologies, thermodynamic solar power uses solar energy to heat an absorber, whose heat is then converted into electricity through a classical thermodynamic cycle. The improvement of the performances of this technology requires the design of absorbers able to operate strongly at high temperature. In this thesis, we explore two different ways for this purpose.The first is based on the design of multilayer structures optimized by a genetic algorithm.We will see that these structures lead to an efficiency higher than 80 %, very close to the fundamental limits, demonstrating so their strong potential for thermodynamic solar technology. The second way is based on the optimization of electromagnetic interactions inside plasmonic nanostructures composed of metal nanoparticles. These structures are the site of cooperative effects between nanoparticles that can exalt strongly losses inside the structure. These mechanisms are exploited to design absorbers based on binary networks made with nanoparticles of gold and silver dispersed in a transparent matrix.

A partir de 2014, o interesse pelas grandes centrais de geração fotovoltaica tem aumentado no Brasil. Visando elevar a produtividade dos sistemas e, com isso, alavancar a competitividade econômica, muitos dos investidores de grandes projetos estão optando pela utilização de sistemas de seguimento solar. Contudo, há pouco conhecimento sobre o real desempenho operacional de sistemas fotovoltaicos com seguimento no país. Este trabalho avalia a operação e o desempenho de sistemas fotovoltaicos com seguimento solar, com e sem concentração, através de dois estudos de caso. No primeiro, foram avaliados e comparados dois sistemas fotovoltaicos com seguimento em dois eixos, um com módulos de concentração e outro com módulos planos, ambos instalados em Ilha Solteira, São Paulo. Já no segundo, realizou-se a avaliação de um sistema fotovoltaico com seguimento de eixo horizontal instalado na Universidade de São Paulo, bem como a comparação deste sistema com um sistema fixo. Para realizar as avaliações nos estudos de caso, foram utilizadas as figuras de mérito produtividade final, YF, rendimento global, PR, e fator de capacidade, FC. No caso dos sistemas de Ilha Solteira, os resultados evidenciam não só que o sistema sem concentração teve um melhor desempenho em relação ao sistema com concentração, como também evidenciam a necessidade de atenção devido às particularidades dos sistemas fotovoltaicos com concentração no Brasil. No caso dos sistemas instalados na Universidade de São Paulo, os resultados mostram que, ao longo de seis meses de operação, o sistema fotovoltaico de eixo horizontal teve um ganho médio de produtividade final de 9% comparado com o sistema fixo. / Since 2014, interest in large-scale photovoltaic power plants has increased in Brazil. Aiming to raise system yield and thereby boost economic competitiveness, many investors are making use of solar tracking systems. However, there is little knowledge on the actual operational performance of photovoltaic systems with solar tracking in the country. This work evaluates the operation and performance of photovoltaic systems with solar tracking capabilities, with and without concentration technology, through two case studies. First, two photovoltaic systems with dual-axis solar tracking, one with concentration modules and the other with flat modules, both installed in Ilha Solteira, São Paulo, are evaluated and compared. Second, the performance of a photovoltaic system with horizontal axis solar tracking installed at the University of São Paulo, São Paulo, is evaluated, followed by a comparison with a fixed photovoltaic system. In order to carry out these assessments, the final yield, YF, the performance ratio, PR, and the capacity factor, FC, were used as figures of merit. Regarding the systems installed in Ilha Solteira, the results not only show that the non-concentrating system performed better than the concentrating system, but also evidences the necessity for attention due to the particularities of the photovoltaic systems with concentration technology in Brazil. As for the systems installed at the University of São Paulo, the results show that the photovoltaic system with horizontal-axis solar tracking had a final average yield 9% higher when compared to the fixed-tilt system.

A number of natural resources can be exploited for providing energy, such as the sun, wind, water flow, tides, waves and deep heat generated within the earth. Recently, renewable resources especially that extracted from solar have been significantly encouraged mainly for environmental worries, such as climate change mitigation and global warming, coupled with high oil cost and security and economic matters. The crucial need of energy in human development has also been another important drive pushing the rapid progresses in renewable technologies, which results in both large-scale strategic projects for covering wide urban and rural areas and simple systems suitable for individual buildings. Solar energy has become a widely desired option, especially in high solar radiation areas. The Middle East, especially Gulf region is an ideal geographical area for solar power where it has one of the highest solar irradiation rates across the world. The population in Gulf Cooperation Council (GCC) countries is significantly small compared to the geographical areas and populations are distributed mostly throughout huge areas forming small villages and rural communities on substantial distances from the main power networks. In Saudi Arabia, there is a crisis in supplying enough electricity to the large cities and domestic remote area in various parts in the country and a wide range of remote areas still suffer from a severe shortage of power supply. In this project, the opportunity of using small-scale solar energy technologies, such as Stand-Alone Building-Integrated PV (SABIPV) systems has been investigated as an optimal solution for providing solar energy to a great deal of off-grid areas in Kingdom of Saudi Arabia and the expected short and long-term impacts of such solution have been studied. The study showed that the main reasons behind the crisis in supplying electricity to domestic remote and rural off-grid areas in Saudi Arabia are the weakness of the financial returns compared to the cost of providing the service, the difficulty of the natural topography of areas, high cost of maintenance works, and the regulations of providing electric services in Saudi Arabia. This is in addition to the expected environmental impacts, such as raising the pollution rates in the area and the safety influences of extending the high voltage lines over huge areas. On the other hand, the lack of the necessary infrastructure services, particularly electricity and the looking forward for better level of prosperity lead people who live in countryside and remote areas usually to immigrate to in-grid areas which has several short and long-term negative impacts on economic, social and security sides. This study shows that SABIPV system is a cost-Impactive, powerful, and fundamental solution for all off-grid areas in Saudi Arabia including remote villages and rural communities and providing the same level of electricity services that can be achieved in urban on-grid areas. The system is expected to have positive impacts including reducing pollution and greenhouse gas emissions, the expansion of agricultural land and reduce desertification, reducing the influence of high-voltage electrical lines on living organisms, providing adequate electricity service at lower cost, offering more job opportunities for people in remote areas, increasing agricultural and handicraft products, developing the tourism sector in rural areas, reducing the rate of migration from rural areas to the cities, and reducing the slum areas in cities which helps to reduce the rate of crimes, ignorance, the low level of morality, and health and environmental problem.

A partir de 2014, o interesse pelas grandes centrais de geração fotovoltaica tem aumentado no Brasil. Visando elevar a produtividade dos sistemas e, com isso, alavancar a competitividade econômica, muitos dos investidores de grandes projetos estão optando pela utilização de sistemas de seguimento solar. Contudo, há pouco conhecimento sobre o real desempenho operacional de sistemas fotovoltaicos com seguimento no país. Este trabalho avalia a operação e o desempenho de sistemas fotovoltaicos com seguimento solar, com e sem concentração, através de dois estudos de caso. No primeiro, foram avaliados e comparados dois sistemas fotovoltaicos com seguimento em dois eixos, um com módulos de concentração e outro com módulos planos, ambos instalados em Ilha Solteira, São Paulo. Já no segundo, realizou-se a avaliação de um sistema fotovoltaico com seguimento de eixo horizontal instalado na Universidade de São Paulo, bem como a comparação deste sistema com um sistema fixo. Para realizar as avaliações nos estudos de caso, foram utilizadas as figuras de mérito produtividade final, YF, rendimento global, PR, e fator de capacidade, FC. No caso dos sistemas de Ilha Solteira, os resultados evidenciam não só que o sistema sem concentração teve um melhor desempenho em relação ao sistema com concentração, como também evidenciam a necessidade de atenção devido às particularidades dos sistemas fotovoltaicos com concentração no Brasil. No caso dos sistemas instalados na Universidade de São Paulo, os resultados mostram que, ao longo de seis meses de operação, o sistema fotovoltaico de eixo horizontal teve um ganho médio de produtividade final de 9% comparado com o sistema fixo. / Since 2014, interest in large-scale photovoltaic power plants has increased in Brazil. Aiming to raise system yield and thereby boost economic competitiveness, many investors are making use of solar tracking systems. However, there is little knowledge on the actual operational performance of photovoltaic systems with solar tracking in the country. This work evaluates the operation and performance of photovoltaic systems with solar tracking capabilities, with and without concentration technology, through two case studies. First, two photovoltaic systems with dual-axis solar tracking, one with concentration modules and the other with flat modules, both installed in Ilha Solteira, São Paulo, are evaluated and compared. Second, the performance of a photovoltaic system with horizontal axis solar tracking installed at the University of São Paulo, São Paulo, is evaluated, followed by a comparison with a fixed photovoltaic system. In order to carry out these assessments, the final yield, YF, the performance ratio, PR, and the capacity factor, FC, were used as figures of merit. Regarding the systems installed in Ilha Solteira, the results not only show that the non-concentrating system performed better than the concentrating system, but also evidences the necessity for attention due to the particularities of the photovoltaic systems with concentration technology in Brazil. As for the systems installed at the University of São Paulo, the results show that the photovoltaic system with horizontal-axis solar tracking had a final average yield 9% higher when compared to the fixed-tilt system.

Swine production represents approximately 40% of the world's meat production, and swine wastes contain high concentrations of organic matter, nitrogen (N) and phosphorus (P). Swine production is intensifying as meat demand increases and concentrated animal feeding operations (CAFOs) are becoming increasingly common, making it difficult to treat the waste generated. A system for holistic treatment of swine waste produced in CAFOs was investigated in this study that sustainably generates energy and recovers N and P as saleable fertilizers. The system uses anaerobic digestion (AD) for methane production and solids stabilization, followed by precipitation of struvite (MgNH4PO4*6H2O) and recovery of N by ion exchange onto natural zeolites. This process is expected to mitigate both eutrophication of receiving waters and greenhouse-gas emissions while generating products that meet agronomic nutrient demands; however, the economic and environmental sustainability remains unknown. The objectives of this study were to: (1) evaluate water quality and the fate of nutrients and ions in each step in the proposed system through pilot and bench scale experiments, (2) evaluate content/quality of struvite precipitates formed in wastewater treatment processes, (3) assess basic composition of zeolite materials that are being considered for use as IX materials, (4) quantify the environmental impact of the proposed system, and (5) estimate the economic benefits and costs of the proposed system. The results of a bench scale evaluation of the system show that although water quality greatly improves throughout the treatment process, the effluent water quality has high concentrations of COD (2,803 mg O2/L) and E. coli (106.3 CFU/100ml). This limits reuse options for the reclaimed water, however a variety of on-farm applications may be suitable. During struvite precipitation, the recovery efficiency of SRP was 87% (60 mg/L recovered); however, although measurements that take into account P in suspended solids show a lower recovery efficiency, they also show higher mass recovery (77% efficiency, 66 mg/L recovered). N recovery during struvite precipitation showed a similar trend, with 49% of TN and 7% of NH4-N being recovered. Struvite recovery can only occur from NH4-N and soluble reactive P. The additional recovery observed is likely due to adsorption of the nutrients onto the precipitate. Therefore, to accurately measure and report recovery, measurements of N and P that take into account suspended solids should be used. In most wastes, magnesium is the limiting constituent for struvite formation, but for swine AD effluents, P is the limiting constituent. Therefore, a higher soluble P concentration would increase recovery potential. The majority of the remaining N and P as well as a significant amount of potassium (K) were recovered during IX. Six struvites from commercial processes as well as our bench-scale experiments were assessed and compared by X-ray diffraction, SEM imaging, and SEM-EDX scans. All samples were confirmed as struvite by XRD, however they varied widely in crystal size and shape. The elemental composition of the samples was similar; however, struvite formed from phosphate mining waste had higher amounts Mg and P, indicating more pure struvite formation. The presence of impurities in some samples was likely due to the reactor design and solids separation methods. XRD was also used to confirm the identity of zeolites. Three clinoptilolites had similar crystal size and elemental composition except for Zeosand [reg] which showed a surface roughness, which likely contributes to higher cation exchange capacity. Chabazite has smaller crystal size and larger pores than clinoptilolite, which also likely contributes to its higher capacity. Life cycle assessment (LCA) was used to evaluate the environmental sustainability of the system and the results suggested that environmental benefits were provided across almost all impact categories. Two alternatives for raising the pH in struvite precipitation (NaOH addition vs. aeration) and two alternatives for zeolite IX materials (chabazite vs. clinoptilolite) were assessed, but there were negligible differences between alternatives. The system was also assessed at a medium and large scale, and the large scale was more environmentally friendly across all categories. Operational impacts were significantly greater than construction impacts; therefore, the environmental impact of the system can be accurately assessed by only including operation. A life cycle cost assessment (LCCA) was also performed on the system and showed a payback period of 39 years for a medium sized system and 15 years for a large size. This, however, is when compared to a "business-as-usual" scenario and does not consider renewable energy credits or government grants. Furthermore, although a larger system is more economically beneficial, this must be balanced with quality of animal care. From a cost standpoint, IX recovery using chabazite is not recommended and struvite precipitation using aeration is more economically beneficial than NaOH addition.

Abstract The purpose of this study is to determine the exact natural frequencies and mode shapes of multi-span uniform and multi-step Euler-Bernoulli beams with various concentrated elements (such as point masses, rotary inertias, linear springs, rotational springs, spring-mass systems, etc.) by using the matrix assembly method (MAM). To this end, the coefficient matrices for an intermediate pinned support, an intermediate concentrated elements, left-end support and right-end support of a beam are derived, first. Next, the overall coefficient matrix for the whole structural system is obtained by using the assembly technique of the finite element method. Finally, the natural frequencies and the associated mode shapes of the vibrating system are determined by equating the determinant of the last overall coefficient matrix to zero and substituting the corresponding values of integration constants into the associated eigenfunctions respectively. The effects of in-span pinned supports and various concentrated elements on the free vibration characteristics of the beam are also studied.

With its long cycle life and scalable design, the vanadium redox flow battery (VRB) is a promising technology for grid energy storage. However, high materials costs have impeded its commercialization. An essential but costly component of the VRB is the ion-exchange membrane. The ideal VRB membrane provides a highly conductive path for protons, prevents crossover of reactive species, and is tolerant of the acidic and oxidizing chemical environment of the cell. In order to study membrane performance and optimize cell design, mathematical models of the separator membrane have been developed. Where previous VRB membrane models considered minimal details of membrane transport, generally focusing on conductivity or self-discharge at zero current, the model presented here considers coupled interactions between each of the major species by way of rigorous material balances and concentrated solution theory. The model describes uptake and transport of sulfuric acid, water, and vanadium ions in Nafion membranes, focusing on operation at high current density. Governing equations for membrane transport are solved in finite difference form using the Newton-Raphson method. Model capabilities were explored, leading to predictions of Ohmic losses, vanadium crossover, and electro-osmotic drag. Experimental methods were presented for validating the model and for further improving estimates of uptake parameters and transport coefficients. / text

Föreliggande studie har syftat till att, genom semistrukturerade djupintervjuer med professionella retuschörer aktiva i branschen, undersöka om gemensamma steg kunde urskiljas genom respondenternas beskrivningar av arbetsprocessen.Genom studien framkom det att respondenterna beskrev likartade processer samt att samarbete med medarbetare var en viktig faktor för ett utvecklande arbete. Beskrivningarna av arbetsprocessen tydde på att samtliga respondenter hade ett personligt intresse för arbetet och branschen.Respondenterna ansåg även att retuschörens tidigare erfarenhet var betydande och till stor del påverkar tidsåtgången för arbeten. De menade också att tidsåtgången även påverkas av hur utförlig arbetsordern är vid uppstart av projektet. Det framkom även att respondenterna själva inte genomför någon utförlig uppföljning och granskning av hur det slutliga materialet används. / The present study aimed to, through semi-structured in-depth interviews with professional retouchers active in the industry, examine if common steps could be identified by the respondents’ descriptions of the work process.The study revealed that respondents described similar processes, and collaboration with colleagues was an important factor for a developing work. The descriptions of the work indicated that all respondents had a personal interest in the work and in the industry.Respondents also felt that the retouchers previous experience was significant and largely affects the duration of the work. They also pointed out that the duration also is affected by the amount of details specified in the work order at the startup of the project. It also emerged that the respondents themselves did not make any detailed follow-up and review of how the final material was used.