No description available.

CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / FAPEMIG - Fundação de Amparo a Pesquisa do Estado de Minas Gerais / Nesta tese foi demonstrado que a associação da técnica eletroanalítica Voltametria de Redissolução Anódica de Onda Quadrada (SWASV, do inglês, Square-Wave Anodic Stripping Voltammetry) com a Análise por Injeção em Batelada (BIA, do inglês, Batch- Injection Analysis) permite o desenvolvimento de métodos analíticos para a determinação de metais (Cu, Cd, Pb, Hg e Zn) em amostras de etanol combustível e biodiesel. Metais podem ser incorporados aos biocombustíveis em processos de armazenagem e transporte, podendo causar danos irreversíveis ao biocombustível, o qual pode danificar motores e causar problemas ambientais. Logo, justifica-se o presente trabalho pela necessidade do desenvolvimento de métodos analíticos visando o controle de qualidade em relação ao teor de metais nestas amostras, preferencialmente métodos de fácil manuseio, rápidos, de baixo custo e robustos. BIA-SWASV permitiu a determinação direta (sem qualquer diluição da amostra) de Cd, Pb, Cu e Zn em etanol combustível empregando eletrodos de Au e filme de Hg. Limites de detecção na faixa de 0,6 a 5 pg L-1, faixa linear de 12,5 a 200 pg L-1 e valores de recuperação entre 87 e 109% foram obtidos para análises de 1 mL de amostra e tempo de deposição de 90 s (tempo total de cada medida de ~200 s). O tempo de injeção da amostra pela micropipeta eletrônica usada no sistema BIA foi de 40 s, ou seja, a deposição dos metais ocorreu mesmo após o término da injeção (transporte difusional das espécies ao eletrodo). Além disso, esta tese apresenta a associação de eletrodos impressos (SPE, do inglês, Screen-Printed Electrode) ao sistema BIA visando o desenvolvimento de métodos analíticos com características portáteis. Este sistema foi combinado a outros componentes que funcionam com uso de baterias como, pipetas eletrônicas, mini-potenciostatos e computador laptop, e aplicado à determinação de metais (Pb, Cu e Hg) em amostras de biodiesel após digestão ácida. Empregaram-se nos experimentos SPE’s com tinta condutora de Au (SPGE, do inglês, Screen-Printed Gold Electrode) como eletrodo de trabalho, reduzindo o volume de amostra a 200 pL (em eletrodos convencionais utilizou-se 1000 pL) com tempo de injeção de 40 s (velocidade de injeção de 5 gL s-1) e, nestas condições, obtiveram-se limites de detecção abaixo de 1,0 gg L-1 (equivalente a 6 gg g-1), faixa linear entre 20 e 280 gg L-1 e valores de recuperação entre 90 e 110% para amostras de biodiesel fortificadas. O baixo consumo de amostra no sistema BIA prolongou o tempo de vida útil do SPGE para um dia inteiro de análises (210 injeções). O sistema BIA associado a técnicas eletroanalíticas permitiu o desenvolvimento de métodos analíticos de baixo custo, simples, precisos, que empregam pequeno volume de amostra, portáteis (sobretudo com o emprego de SPE’s), que podem ser aplicados para a determinação de rotina e em campo de metais em amostras de etanol combustível e biodiesel. / In this thesis it is shown that the association of electroanalytical technique Square- Wave Anodic Stripping Voltammetry (SWASV) with Batch-Injection Analysis (BIA) allows the development of analytical methods for determination of metals (Cu, Cd, Pb, Hg and Zn) in ethanol fuel and biodiesel samples. Metals can be incorporated into biofuels during storage and transportation processes, which can damage engines and cause environmental problems. Therefore, it becomes necessary to develop analytical methods aiming the quality control of metals in these samples, preferably methods that are easy to operate, fast, inexpensive and robust. BIA-SWASV allowed direct determination (no dilution of the sample) of Cd, Pb, Cu and Zn in fuel ethanol employing Au and Hg film electrodes. Detection limits in the range of 0.6 to 5 pg L"1, linear range from 12.5 to 200 pg L-1 and recovery values of between 87 and 109% were obtained for analysis of 1 mL of sample and deposition time of 90 s (total time of each measurement of ~200 s). The time of sample injection by the electronic micropipette used by the BIA system was 40 s, that is, the deposition of metal occurred even after the end of injection (diffusional transport of species to the electrode). In addition, in this thesis it is presented the combination of Screen-Printed Electrodes (SPE) to the BIA system aimed to the development of analytical methods with portable characteristics. This system was combined with other components that operate using batteries as electronic pipettes, mini- potentiostat and laptop computer, and applied to the determination of metals (Pb, Cu and Hg) in biodiesel samples after acid digestion. It was used in the experiments SPE's with Au conductive ink as a working electrode (SPGE), reduced the volume of sample to 200 pL (in conventional electrodes was used 1000 pL) with injection time of 40 s (injection rate of 5 pL s-1), and in these conditions, detection limits lower than 1,0 pg L-1 (equivalent to 6 pg g-1), linear range between 20 and 280 pg L-1 and recovery values between 90 and 110% for biodiesel fortified samples were obtained. The low sample consumption extended the lifetime SPGE’s for a whole day of analysis (210 injections). BIA system associated with electroanalytical techniques allowed the development of inexpensive,simple, accurate, portable (especially with the use of SPE's) analytical methods, employing reduced sample volume, which can be applied for the routine and on-site determinations of metals in ethanol fuel and biodiesel samples. / Tese (Doutorado)

This dissertation takes part of researches and discussions that aim to verify the digital inclusion process on Special and Inclusive Education. From the investigation of docent knowledge it aims to understand how are constituted and dimensioned by the practices referring to the resources by which children with visual impairments may access knowledge. The research context was the specialized educational assistance in municipal schools of Uberlândia, Minas Gerais, Brazil, where thirteen students with visual impairments receive a curricular and pedagogical complementation. They are enrolled in nine Basic Education schools in the city. The theoretical framework focuses on information and critical reflections concerning to three main challenges of our time: the Inclusive Education, the digital inclusion and the inclusion of ICTs Information and Communication Technologies in the Education of students with visual impairments. During the course of this dissertation, moved by the characteristic contexts of the present digital age, we proposed to analyze Braille System and the computer with screen reader as resources involved in reading, writing and information access problems, as well in accessing information, knowledge and social interaction. The search method was conducted under a historical and cultural approach, according to Gonzalez Rey s qualitative epistemology. The interviewed subjects culture and identity come into play to determine their knowledge and skills with ICT. We used semistructured interviews as data collection resource. These data were further analyzed under the Content Analysis approach described by Bardin. Data construction resulted in the formulation of categories or analysis axes established from the aspects considered as fundamental in order to include the entire focused reality. From this reality, we discussed the constitution of docent knowledges, the challenges and the possibilities on using the ICT, the didactical aspects and finally, we described the difficulties verified as a result of the inclusion and the exclusion that summit teachers and students. The results reveal knowledges and practices consonant to individual and social culture of teachers, which are characteristic of the historical range we find ourselves, concerning to as the assimilation of digital technologies for education and society. / Essa dissertação integra-se às pesquisas e discussões empreendidas com o intuito de potencializar o processo de inclusão digital na Educação Especial e na Educação Inclusiva. A partir da investigação dos saberes docentes, objetiva compreender como são constituídos e dimensionados por meio das práticas referentes aos recursos de acesso ao conhecimento para crianças com deficiência visual. O contexto da pesquisa foi o atendimento educacional especializado das escolas municipais de Uberlândia, em que recebem complementação curricular e pedagógica treze alunos com deficiência visual matriculados em nove escolas de Ensino Fundamental. O referencial teórico focaliza-se em informações e em reflexões críticas atinentes a três grandes desafios sociais dos nossos tempos: O desafio da Educação Inclusiva, o da inclusão digital, e o da inclusão das TICs na Educação de alunos com deficiência visual. Durante o percurso desta dissertação, motivados pelos contextos característicos da presente era digital, propusemo-nos a analisar o sistema Braille e o computador com leitor de tela como recursos envolvidos na problemática de leitura, da escrita e do acesso à informação, ao conhecimento e à interação social. A metodologia da pesquisa foi conduzida sob um enfoque histórico-cultural, conforme a epistemologia qualitativa de Gonzalez Rey, em que a cultura e a identidade dos sujeitos entrevistados entram em ação para determinar seus saberes e habilidades com as TICs. Entrevistas semiestruturadas foram empregadas como recurso na coleta dos dados, posteriormente analisados na perspectiva da análise de conteúdos descrita por Bardin. A construção dos dados culminou com a formulação de categorias ou eixos de análise pontuados a partir de aspectos considerados fundamentais para a abrangência de toda a realidade em foco. Dessa realidade, discutimos a constituição dos saberes docentes, os desafios e as possibilidades docentes na utilização das TICs, os aspectos didáticos e metodológicos e, por fim, tematizamos as dificuldades verificadas como resultantes da inclusão e exclusão a que professores e alunos encontram-se submetidos. Os resultados revelam saberes e práticas consoantes à cultura individual e social dos docentes, característicos do intervalo histórico em que nos encontramos quanto à assimilação das tecnologias digitais pela Educação e pela sociedade em geral. / Mestre em Educação

The work of this master thesis is based on analyses of monthly precipitation data from 70 stations of the SMHI (Swedish Meteorological and Hydrological Institute) in Sweden, in the period 1860-2014, using the information for the year of introduction of the wind shield at each station. The primary goal is the calculation of correction factors which will be applied on the precipitation data in the period of measurements before the introduction of the wind shield. This correction will counterbalance the underestimation of the collected precipitation by the unshielded precipitation gauges due to the effect of the wind. The wind induced error, related to aerodynamical effects, increases with increasing wind speed. The stronger the wind, the more capable it is of deflecting the precipitation water droplets or snowflakes, falling towards the gauge orifice, away from it. In spite of the important efficiency of the wind shield which acts to diminish the wind error, the long-term effect of changing the measuring instrumentation at some time in the observations history is the production of inhomogeneous data in the measurements records. Inhomogeneous precipitation data are sources of errors in climatology and hydrology and result in misleading conclusions regarding the climate change and climate variations, hence they should be identified and corrected through a homogenization method. The analysis includes the comparison of the precipitation data of each station during two periods, one before and one after the introduction of the wind shield. This comparison leads to the calculation of ratios representing the increase in the catch between the two periods due to the introduction of the wind shield. Temperature data are also processed in order to estimate the type of precipitation (snow/rain) in each case. The monthly corrections ranged between 5 %, for rain, and 27 % for snow precipitation. The absolute value of the increase of the average annual precipitation due the implementation of the correction was 50 mm. The comparison of the corrected against the uncorrected precipitation time series indicated a less pronounced increase (0.74 mm/y) of the precipitation during the last 150 years, after the application of the correction, compared to the increase indicated from the uncorrected data (1.19 mm/y). / Kontinuerliga samt felfria nederbördsmätningar är av stor betydelse för geovetenskaper som klimatologi och hydrologi därför att nederbördsdata är en av de primära meteorologiska parametrarna för forskning om klimatförändringen. Att säkerställa felfria (homogena) nederbörds tidsserier betyder i stort sett att säkerställa homogenitet genom att identifiera och korrigera inhomogena data. Icke homogena data uppkommer på grund av förändringar i mätmetoder och mätförhållanden under observationstiden, sedan 1860-talet tills idag alltså. Denna studies syfte är att beräkna en korrektion som ska användas för att korrigera nederbördsmätningar som utfördes sedan 1860 utan vinskydd. Vindskyddet eller vindskärmen, en speciell utrustning som användas på nederbördsinsamlare, infördes gradvis under perioden 1900-1960 vid de svenska nederbördstationerna. Vindskyddet introducerades med avsikt att minska vindens påverka vid nederbördsinsamling. Men trotts den positiva effekten som vindskyddet ledde till, genom den ökade nederbördsmängden som samlades in, skapade denna förändring av mätarutrustningen inhomogena data. Bearbetningen skedde för månadsnederbördsdata från 70 stationer från SMHIs meteorologiska nätverk genom att jämföra nederbördsobservationer som genomfördes under perioderna tio år före och tio år efter införandet av vindskydd. Dessutom användes temperaturdata från samma stationer för att uppskatta nederbördslag (snö/regn). Skälet till detta är att vinskyddseffekten är olika mellan snö och regn. Beräkningarna och bestämningen av nederbördslag ledde till en 5 % respektive 27 % nederbörds ökning för regn och snö för de mätningarna som utfördes utan vindskydd. I genomsnitt har de korrigerade värdena, under perioden som vinskyddet saknades, ökat med omkring 50 mm.

Philosophiae Doctor - PhD / A novel monomer (N,N'-Bis-(1H-pyrrol-2-ylmethylene)-benzene-1,2-diamine-BPPD) was derived from the condensation reaction between o-phenylenediamine and a pyrrole derivative. The monomer was polymerized electrochemically to produce the new polymer material - polymerized(N,N'-Bis-(1H-pyrrol-2-ylmethylene)-benzene-1,2-diamine) PBPPD. This novel polymer material was deposited at the surface of a screen-printed carbon electrode, as a thin film, in the development of chemical sensors for the detection of polycyclic aromatic hydrocarbons (PAHs). The monomer material was characterized in terms of its optical (spectroscopy) and thermal properties. The polymer material was characterized in terms of its surface morphology and its redox electrochemistry. Fourier transform infrared spectroscopy (FTIR) was used to confirm the azomethine bond formation during the condensation reaction of an aldehyde and primary amine derivative. / 2020-08-31

L’identification d’antiviraux à large spectre est un des défis majeurs de la rechercheactuelle en virologie. Une des stratégies les plus prometteuses consiste à cibler une interactionvirus/hôte conservée. Ainsi, avec la technique d’AlphaScreen® et le modèle d’interactionprotéine VI de l’Adénovirus (AdV)/Nedd4-2, nous avons réalisé un criblage biochimique àhaut débit contre l’interaction virus/hôte [LP]PxY/Nedd4, commune à différentes familles devirus. Nous avons trouvé des candidats inhibiteurs issus d’une banque de composés approuvéspar les agences de santé. Nous les avons testés, caractérisés et validé leur effet antiviral surdeux familles de virus totalement différentes. Ainsi, les composés C9 (Sulconazole) et C4(Flunarizine) que nous avons identifiés diminuent la réplication de l’AdV, un virus à ADNenveloppé et du virus de Marburg, un virus à ARN, non enveloppé de la famille desFiloviridae. Ces résultats ont permis de valider l’interaction [LP]PxY/Nedd4 comme unecible idéale d’un antiviral à large spectre et de proposer un repositionnement de ces moléculesC9 et C4 comme antiviraux potentiels. Nous avons également synthétisé de nouvellesmolécules analogues du composé C9 et démontré qu’elles étaient tout aussi efficaces que lecomposé lui-même sur la réplication de l’AdV. Ces résultats nous ont permis de présenter laclasse des dérivés imidazolés comme structure de base pour l’élaboration de nouveauxantiviraux, potentiellement à large spectre. / Broad-spectrum antiviral identification is considered as one of the major aims of theactual virology research and one strategy consists in targeting virus/host interaction. Using theAlphaScreen® technology and the adenoviral model protein VI/Nedd4-2, we performed highthroughputbiochemical screening targeting the [LP]PxY/Nedd4 interaction, a commoninteraction of different virus families. We identified candidate inhibitors from a librarycompound approved by health agencies. We tested, characterized and validated the antiviraleffect of those compounds on two very different virus families. Indeed, compounds C9(Sulconazole) and C4 (Flunarizine) decrease replication of the adenovirus, a DNA nonenvelopedvirus and the replication of the Marburg virus, an RNA enveloped virus from theFilovirus family. Taken together, those results permit us to validate the [LP]PxY/Nedd4interaction as good target for a broad spectrum antiviral and to propose the “repositioning” ofcompounds C4 and C9 as antivirals. Moreover, we have synthesized new analogues from C9showing similar effect on AdV replication compared to the original molecule (C9). Inconclusion, our work on developing new broad-spectrum antivirals highlights the possibilityto use imidazole derivatives as a new class of antiviral compounds.

Hamrebäcken rinner genom östra delen av Västerås och har Mälaren som recipient. Under bäckens flödesväg tillkommer dagvatten och föroreningar i form av näringsämnen och tungmetaller från dess avrinningsområde. Bäcken utgör ett av de mest prioriterade vattendragen i Västerås gällande utsläpp av dagvatten. Detta examensarbete har utförts med syftet att utreda föroreningssituationen för Hamrebäcken och hur dess recipient Mälaren påverkas. Examensarbetet syftade även till att undersöka reningseffekten för en befintlig dagvattendamm samt att utifrån ett kostnads- och reningsperspektiv beskriva ett antal åtgärdsförslag för att uppnå en förbättring av bäckens ekologiska och kemiska status. Utvärdering av Hamrebäckens föroreningsbelastning samt reningseffekt för befintlig dagvattendamm och åtgärdsförslag utfördes med hjälp av den Excelbaserade dagvatten- och recipientmodellen StormTac.   Resultatet från studien visade att den modellerade belastningen från flera av bäckens delavrinningsområden överskrider föreslagna riktvärden för mindre vattendrag. Den totala belastningen från Hamrebäckens avrinningsområde överskrider i fallet för föroreningarna bly och suspenderat material även föreslagna riktvärden för Mälaren. Modellering av den befintliga dammen indikerar att anläggningen är underdimensionerad i förhållande till dess belastningsyta. Dammens reningseffekt uppnår inte heller effektmålen i Västerås stads handlingsplan för dagvatten. Ett förslag om utbyggnation av dammen har tagits fram utifrån litteraturstudie och tillgänglig yta för åtgärden. Den simulerade ombyggnationen uppnådde inte uppsatta effektmål men gav en betydande ökning i reningseffekt. Åtgärder som syftar till att öka dammens avskiljningsförmåga bör därför utredas ytterligare.   Fyra ytterligare åtgärdsförslag togs fram och reningseffekten av dessa modellerades i StormTac. Detta inkluderade två olika placeringar av dagvattendammar, en skärmbassäng med flytande våtmark, samt en konstruerad våtmark. Från genomförd modellering rekommenderas vidare utredning av åtgärdsförslagen inkluderande ett anläggande av en skärmbassäng med flytande våtmark, alternativt en konstruerad våtmark. Detta då dessa åtgärdsförslag uppnådde effektmålen för rening enligt Västerås stads handlingsplan för dagvatten. Åtgärdsförslagen skilde sig något åt gällande kostnadseffektivitet. Detta ansågs dock inte ensamt vara argument nog för att motivera anläggning av något åtgärdsförslag till följd av osäkerheter i det beräknade resultatet. Att en skärmbassäng kan utföras i närtid och inte kräver några ingrepp i avrinningsområdet kan anses som ytterligare argument för installation av anläggningen. En konstruerad våtmark kan i sin tur motiveras med att anläggningen bidrar till att höja det estetiska och ekologiska värdet av området. Dessa argument bör beaktas i valet av metod och det fortsatta arbetet med att minska områdets föroreningsbelastning och förbättra bäckens ekologiska och kemiska status. / Hamrebäcken is a small stream in Västerås, which flows through the eastern part of the city. Along it’s course to Lake Mälaren, the stream receives polluted stormwater containing such as heavy metals and nutrients. The primary objective of this master thesis was to investigate the level of pollutants in Hamrebäcken. A secondary objective was to study the reduction efficiency of an existing wet stormwater treatment pond in the area, and propose ways in which to achieve a higher ecological and chemical status for the stream. The stormwater and recipient software model StormTac was used to estimate the level of pollutants and to investigate the reduction efficiencies of different stormwater treatment facilities.   The study revealed that pollutant levels were too high for several of the subwatersheds, based on the recommended guidance for small streams. The pollutant load for the total watershed exceeded the guidance levels for Lake Mälaren for lead and suspended solids. Modelling the reduction efficiency of the existing wet pond indicated that the pond’s size was inadequate to cater for the quantity of incoming stormwater in need of treatment. Subsequently, the pollution reduction efficiency of the pond was not meeting those objectives set out in the Stormwater Action Plan developed by Västerås municipality. A proposal for rebuilding the pond was therefore developed, taking into account the existing conditions of the area and using recommendations from literature. When modeled in StormTac, the modified pond showed a substantial increase in reduction efficiency compared to that of the existing pond. Despite not reaching the objectives of the Action Plan, this suggested that it would be beneficial to investigate measures that increase the reduction efficiency of the existing wet pond further. As a result, an additional four alternatives for reducing the pollutant load of Hamrebäcken were developed using StormTac. These consisted of two wet stormwater treatment ponds at different locations within the watershed, a screen basin with floating treatment wetlands, and a constructed wetland.   The modeling revealed that the most feasible of the investigated measures was an installation of either a screen basin with floating treatment wetlands or a constructed wetland, both measures adjacent to the outlet of Hamrebäcken. This was mainly due to the modeled reduction capacity of these measures where the reduction objectives of the Action Plan were reached. A difference in cost effectiveness was found between the different measures. This was however not considered to solely be argument to justify the implementation of a certain measure due to uncertainties in the modelled result. The fact that a screen basin can be installed in the near future and without occupying space in the watershed are additional arguments for the use of this measure. A constructed wetland can in return be motivated by a potential increase in esthetic and ecological value of the area. These arguments should be considered in the continued investigation of choosing a measure for reducing the pollutant load of Hamrebäcken and to achieve a higher ecological and chemical status for the stream.

En tant que préalable à l’appréciation d’une forme, le cadre demeure une question centrale en esthétique de l’image. Où débute une forme, où s’achève-t-elle ? Si le cadre délimite l’image en y circonscrivant un espace au regard, il peut jouer de ses plasticités et renverser ce présupposé en son contraire : la tendance all-over de l’expressionnisme abstrait montre bien des exemples où le cadre se défait dans une ouverture qui rend l’espace à son indétermination, fut-elle fixée à l’avant de notre regard. Le point de départ de cette recherche vient du concept établi par Meyer Schapiro du cadre comme « véhicule matériel » où il y fait distinction entre l’image-objet (absence de limites de surface et visibilité du support) et l’image-signe (limite de surface liée à la représentation). Faisant état de cette différence fondamentale, nous proposons un travail interdisciplinaire – le cinéma expérimental et sa relation avec les autres arts – où l’œuvre d’Andy Warhol servira de fil conducteur. A partir d’une première occurrence appelée cadre-surface, il semble important de revenir sur certains malentendus concernant le Pop art tant sur le plan historique, philosophique, qu’esthétique en proposant le concept de « ready-made illusionniste ». Dans un deuxième temps, le cadre-perception sera l’occasion d’affiner notre travail en revenant sur la position du spectateur face aux images à travers le concept de « Pensée visuelle » développé par Rudolf Arnheim. On verra de quelle façon le cinéma expérimental à tendance structurelle et matérialiste (Michael Snow, Paul Sharits, Peter Gidal) se nourrit de la relation figure-fond établit par la psychologie de la forme (gestalt). Par là, comment le film ouvre aux possibles phénoménologiques d’un autre rapport à l’image ? Enfin, la dernière partie situera le cadre à sa propre destitution physique dans un chemin qui va du cadre-écran au cadre-performance. Devant cette typologie quelque peu taxinomique, nous souhaitons moins y penser un cloisonnement entre les différents types de cadre qu’y trouver force circulaire afin de répondre à l’hypothèse suivante : en quoi la matérialité des premiers films de Warhol nous engage progressivement dans une réflexion ambiguë parce qu’ambivalente autour d’une image spectrale et dématérialisée ? / As a prerequisite to the assessment of a form, the framework remains a central issue in the aesthetics of the image. Where does a form begin, where does it end? If the frame defines the image circumscribing there a space for the eye to see, it can play of its plasticity and overturn this assumption into its opposite: the all-over pattern of abstract expressionism shows examples where the frame opens up to an undetermined space, whether it might have been fixed or not before we set eyes on it. The starting point for this research comes from the concept established by Meyer Schapiro of the frame as a "material vehicle" where he makes a distinction between the image-object (no surface boundaries and visibility of support) and the image-sign (surface boundary associated with the representation). Stating this fundamental difference, we propose an interdisciplinary work - experimental cinema and its relationship to the other arts - where Andy Warhol’s work will serve as a guideline. From a first occurrence called frame-surface, it seems important to revisit some misunderstandings about Pop art, historically, philosophically, and aesthetically, by proposing the concept of "ready-made illusionist". Secondly, the frame-perception will be an opportunity to refine our work by returning to the position of the viewer facing images through the concept of "visual thinking" developed by Rudolf Arnheim. We'll see how experimental film with structural and materialistic tendency (Michael Snow, Paul Sharits, Peter Gidal) feeds on the figre-ground organization established by the psychology of form (Gestalt). Then, how does the film open to the phenomenological possibilities of another connection to the image? The last part will place the frame over its own physical removal on a path that goes from frame-screen to frame-performance. Given this typology somewhat taxonomic, we wish to think of it less as a division between different types of frame than to find circular strength in it, in order to meet the following hypothesis: how does the materiality of early Warhol films progressively engage us in an ambiguous, since ambivalent, reflection around a spectral and dematerialized image?

Cette étude est dédiée au développement d’une anode pour une pile à combustible SOFC monochambre. Ce dispositif ne présente pas de séparation physique entre les compartiments anodique et cathodique, contrairement à une pile conventionnelle. Un mélange contenant de l’oxygène et un hydrocarbure est directement injecté sur l’ensemble du dispositif comprenant électrolyte, anode et cathode. La cathode doit être sélective à la réduction de l’oxygène et l’anode à l’oxydation de l’hydrocarbure. Ce dispositif permet donc de s’affranchir des problèmes d’étanchéité des dispositifs conventionnels mais les matériaux d’électrode doivent répondre à des critères catalytiques restrictifs. L’étude a été réalisée avec une anode de type cermet composée de nickel et d’oxyde de cérium gadolinié (CGO). L’hydrocarbure choisi est le propane. L’objectif du travail est de comprendre les phénomènes physico-chimiques se produisant à l’anode afin d’optimiser les conditions de fonctionnement de la pile monochambre, sous mélange O2 / C3H8. Pour cela, les propriétés catalytiques des poudres de nickel et de CGO ont été déterminées en fonction de la température et du rapport O2 / C3H8. Après avoir optimisé les paramètres de préparation des anodes par sérigraphie sur électrolyte support (CGO), des mesures de conductivité électrique par méthode Van der Pauw ont été réalisées également sous différents mélanges O2 / C3H8 en fonction de la température. La confrontation des résultats (propriétés catalytiques et électriques) a permis de mettre en évidence l’existence d’une température limite de fonctionnement, qui dépend du rapport O2 / C3H8. En-dessous de cette température limite, le nickel s’oxyde et l’anode catalyse principalement l’oxydation totale du propane. Au-dessus de cette température limite, le nickel reste sous la forme métallique et catalyse préférentiellement l’oxydation partielle du propane. Ces résultats sont également corroborés à des calculs thermodynamiques, qui mettent en évidence que la réaction préférentielle à basse température est l’oxydation du nickel. Des phénomènes d’oscillations de la conductivité électrique et de la température ont permis de proposer un mécanisme réactionnel basé sur le dépôt et l’oxydation de carbone. Enfin, des dispositifs complets monochambre ont été élaborés en utilisant une cathode BSCF (Ba0,5Sr0.5Co0,8Fe0,2O3) et testés. / This work is devoted to the development of a single chamber SOFC. Unlike a conventional SOFC, this type of fuel cell has no physical separation between the anodic and cathodic compartments. An oxygen and hydrocarbon mixture is injected directly on the overall fuel cell, including the electrolyte, the anode and the cathode. The cathode must have a high selectivity to the oxygen reduction, and the anode to the hydrocarbon oxidation. This device allows to avoid the conventional devices sealing problems, but the electrodes materials must fit with restrictive catalytic criterions. The study has been conducted with a cermet anode type, composed of nickel and gadolinia doped ceria (CGO). The selected hydrocarbon was the propane. The goal of this work is to understand physico-chemical processes taking place at the anode in order to optimize the operating conditions of the fuel cell, in an O2 / C3H8 mixture. The catalytic properties of nickel and CGO powders were determined as a function of temperature and O2 / C3H8 ratio. After optimization of the anode screen-printing conditions preparation on a CGO support, electrical measurements were done using the Van der Pauw method under different O2 / C3H8 mixtures as a function of temperature. The results of catalytic and electrical measurements show a limiting operating temperature, which depends on the O2 / C3H8 ratio. Below this limiting temperature, the nickel is oxidized and principally catalyses the total oxidation of the propane. Above this limiting temperature, nickel remains into its metallic state and preferentially catalyses the partial oxidation of the propane. These results are also corroborated to thermodynamics calculations, which show that at low temperature, the oxidation of nickel is the most favourable reaction. Some oscillations of the conductivity have been observed. Oscillations of electrical conductivity and temperature allowed proposing a reaction mechanism based on carbon deposition and oxidation. Finally, complete single chamber devices have been elaborated using a BSCF (Ba0,5Sr0.5Co0,8Fe0,2O3) cathode and tested.

As technology evolves, new devices and interaction techniques are developed. These transformations create several challenges in terms of usability and user experience. Our research faces some challenges for data input or content exploration in scenarios with restrictions. It is not our intention to investigate all possible scenarios, but we deeply explore a broad range of devices and restrictions. We start with a discussion about the use of an interactive coffee table for exploration of personal photos and videos, also considering a TV set as an additional screen. In a second scenario, we present an architecture that offers to interactive digital TV (iDTV) applications the possibility of receiving multimodal data from multiple devices. Our third scenario concentrates on supporting text input for iDTV applications using a remote control, and presents an interface model based on multiple input modes as a solution. In the last two scenarios, we continued investigating better ways to provide text entry; however, our restriction becomes not using the hands, which is the kind of challenge faced by severely motor-disabled individuals. First, we present a text entry method based on two input symbols and an interaction technique based on detecting internal and external heel rotations using an accelerometer, for those who keep at least a partial movement of a leg and a foot. In the following scenario, only the eyes are required. We present an eye-typing technique that recognizes the intended word by weighting length and frequency of all possible words formed by filtering extra letters from the sequence of letters gazed by the user. The exploration of each scenario in depth was important to achieve the relevant results and contributions. On the other hand, the wide scope of this dissertation allowed the student to learn about several technologies and techniques. / Com a evolução da tecnologia, novos dispositivos e técnicas de interação são desenvolvidas. Essas transformações criam desafios em termos de usabilidade e experiência do usuário. Essa pesquisa enfrenta alguns desafios para a entrada de dados e exploração de conteúdo em cenários com restrições. Não foi intenção da pesquisa investigar todos os possíveis cenários, mas sim a exploração em profundidade de uma ampla gama de dispositivos e restrições. Ao todo cinco cenários são investigados. Primeiramente é apresentada uma discussão sobre o uso de uma mesa de centro interativa para a exploração de fotos e vídeos pessoais, a qual também considera um aparelho de TV como tela adicional. Com base no segundo cenário, uma arquitetura que oferece a aplicações de TV digital interativa (TVDI) a possibilidade de receber dados multimodais de múltiplos dispositivos é apresentada. O terceiro cenário se concentra no suporte a entrada de texto para aplicações de TVDI usando o controle remoto, resultando na apresentação de um modelo de interface baseado em múltiplos modos de entrada como solução. Os dois últimos cenários permitem continuar a investigação por melhores formas de entrada de texto, porém, a restrição se torna a impossibilidade de usar as mãos, um dos desafios enfrentados por indivíduos com deficiência motora severa. No primeiro deles, são apresentados um método de entrada de texto baseado em dois símbolos de entrada e uma técnica de interação baseada na detecção de rotações do pé apoiado sobre o calcanhar usando acelerômetro, para aqueles que mantêm pelo menos um movimento parcial de uma perna e um pé. No senário seguinte, apenas os movimentos dos olhos são exigidos. Foi apresentada uma técnica de escrita com o olho que reconhece a palavra desejada ponderando o comprimento de a frequência de ocorrência de todas as palavras que podem ser formadas filtrando letras excedentes da lista de letras olhadas pelo usuário. A exploração de cada cenário em profundidade foi importante para a obtenção de resultados e contribuições relevantes. Por outro lado, o amplo escopo da dissertação permitiu ao estudante o aprendizado de diversas técnicas e tecnologias.