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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
231

Etude du traitement de désinfection des eaux de refroidissement par le couplage H2O2/UV : application à une tour aéroréfrigérante / Disinfection process study of cooling water by H2O2/UV : application to a cooling tower

Putois, Tamara 10 October 2012 (has links)
Les légionelles sont un enjeu de santé publique majeur car ces bactéries sont responsables des cas de légionellose, parfois mortels. Les tours aéroréfrigérantes (TAR) peuvent être incriminées car pouvant potentiellement émettre des aérosols contaminés. Un traitement de désinfection de ces eaux est donc nécessaire. Cependant les techniques actuelles conduisent très souvent à des injections importantes de réactifs induisant des rejets écotoxiques dans l'environnement qu'il est nécessaire de limiter. L'application du traitement d'oxydation avancée H2O2/UV – considéré comme innovant pour ce domaine et dont l'impact environnemental est limité (décomposition du peroxyde d'hydrogène en eau et oxygène, peu de production de composés toxiques) – a prouvé son efficacité de désinfection à la fois au sein d'un pilote de laboratoire sur une eau reconstituée, chargée en microorganismes et matière organique, mais aussi lors du traitement de l'eau d'une TAR du secteur tertiaire. Les ultraviolets ont été appliqués de manière continue (10 à 22 J.cm-2 sur le pilote ; 2 à 7 J.cm-2 sur la TAR) avec le maintien d'un résiduel constant en peroxyde d'hydrogène (10 à 50 mg.L-1 sur le pilote ; 3 à 10 mg.L-1 sur la TAR). Sur le pilote de laboratoire, le traitement H2O2/UV a montré une efficacité supérieure à l'application des UV ou du peroxyde d'hydrogène seul. Des abattements plus importants sur les paramètres microbiologiques de l'eau et des biofilms (ATP, bactéries cultivables et totales) et une modification profonde de la matière organique (minéralisation) ont pu être observés. Il a ainsi été conservé les avantages de chaque technique (désinfection reconnue des UV et action bactéricide de H2O2), tout en limitant leurs inconvénients (absence de rémanence des UV, fortes concentrations nécessaires en H2O2) grâce à la génération de radicaux hydroxyles pouvant agir sur les microorganismes et la matière organique. L'étude sur une TAR a confirmé ces résultats et a montré de bonnes performances de désinfection en comparaison avec celles obtenues pour le dioxyde de chlore. Cependant, lors les phases d'optimisation des essais, une adaptation des bactéries au peroxyde d'hydrogène a été observée indiquant la nécessité d'un contrôle régulier de cet oxydant afin de maintenir un résiduel conséquent et d'éviter la mise en place d'une dérive du système. De plus, il a été montré que le traitement n'a eu qu'une faible action sur les produits de conditionnement de l'eau (antitartre, anticorrosion). Une rapide évaluation économique a permis de placer le couplage H2O2/UV dans le même ordre de grandeur que les traitements habituels. / Legionella is a major public health issue as they are responsible for Legionnaires' disease, which can be fatal. Cooling towers are often incriminated because of their potential emission of contaminated aerosols. A disinfection process for treating water is then necessary. However, current techniques often need high concentrations of chemical products which lead to ecotoxic releases into the environment. UV-H2O2 is an advanced oxidation process with a limited environmental impact (hydrogen peroxide decomposition into oxygen and water, low production of toxic compounds). It was shown that this method is an effective technique of disinfection both in a laboratory pilot on water charged with microorganisms and organic matter, and in the water treatment of a cooling tower (service sector). UV irradiation was applied continuously (10 – 22 J.cm-2 on the pilot; 2 – 7 J.cm-2 on the cooling tower) with a constant residual of hydrogen peroxide (10 to 50 mg.L-1 on the pilot; 3 to 10 mg.L-1 on the cooling tower). On the laboratory pilot, UV-H2O2 showed a higher efficacy than UV or hydrogen peroxide treatments applied alone. A more important reduction of microbiological parameters in water and biofilms (ATP, heterotrophic plate and total bacteria counts) and a deep change in organic matter (mineralization) were observed. The advantages of each process (both well-known UV disinfection and bactericidal action of H2O2) were selected by limiting their disadvantages (no residual with UV, need for high concentrations of H2O2) through the generation of hydroxyl radicals, acting on microorganisms and organic matter. The study on a cooling tower confirmed these results and showed good disinfection performances compared with those obtained for chlorine dioxide. However, the optimization phases of the treatment highlighted a bacterial adaptation to hydrogen peroxide. A monitoring of this oxidant is required in order to maintain a residual, and therefore to avoid a drift of the system. Besides, UV-H2O2 showed little effect on scale and corrosion inhibitors. A rapid economic assessment allowed to placing UV-H2O2 in the same order of magnitude as usual treatments.
232

Espectro da ponte estaiada e do mirante em meio ao circuito do turismo de negÃcios & eventos

Morgana Melca Braga Sampaio 00 August 2018 (has links)
nÃo hà / Esta dissertaÃÃo, denominada Espectro da Ponte Estaiada e do Mirante em meio ao circuito do Turismo de NegÃcios & Eventos, objetiva compreender, no campo da avaliaÃÃo de polÃticas pÃblicas, a concepÃÃo da polÃtica de turismo para a cidade de Fortaleza atravÃs da construÃÃo de Ãcones urbanos, vinculados ao setor turÃstico, notadamente o segmento de NegÃcios & Eventos. Toma como objeto especÃfico de sua avaliaÃÃo, a proposta do Governo do Estado do Cearà em construir a Ponte Estaiada e o Mirante como Ãcones urbanos para atrair novos fluxos do capital financeiro e investimentos no setor turÃstico. A despeito da nÃo materialidade das obras, seus espectros mantÃm a atualidade polÃtica, uma vez que foram constituÃdos dentro de novas configuraÃÃes de turismo de NegÃcios & Eventos em consonÃncia com as linhas prevalecentes das polÃticas pÃblicas de turismo no Estado do Cearà das Ãltimas dÃcadas. O eixo central da anÃlise realiza a crÃtica da lÃgica intrÃnseca à concepÃÃo de desenvolvimento da cidade, a partir dos investimentos na Ãrea do turismo na construÃÃo de novos equipamentos, marcada ainda pela forte intervenÃÃo do Estado junto à esfera privada, remodelando o espaÃo da cidade sob a Ãgide da acumulaÃÃo do capital. Inspirada no modelo de âAvaliaÃÃo em Profundidadeâ, desenvolvida por Rodrigues (2008), que em seu construto estabelece procedimentos sistemÃticos de investigaÃÃo, baseados em eixos de anÃlise que orientam as prÃticas investigativas na Ãrea, empreendi esforÃos avaliativos a partir dos trÃs primeiros eixos analÃticos configurados pela autora (anÃlise de conteÃdo do programa, contexto da formulaÃÃo da polÃtica e trajetÃria institucional). Avaliei documentos oficiais e fiz uso de entrevistas nÃo estruturadas, sendo esta a principal tÃcnica investigativa, se configurando em uma pesquisa predominantemente qualitativa. Em decorrÃncia dessa opÃÃo, meu plano investigativo transcendeu a anÃlise de dados quantitativos coletados em formatos padronizados ou em abordagens lineares. Como resultado dessa avaliaÃÃo, pude compreender a metrÃpole como um lugar onde as transformaÃÃes urbanas e a produÃÃo do espaÃo sÃo realizadas em funÃÃo da reproduÃÃo do capital e a total preponderÃncia dessas obras e projetos urbanos diante da falta de instrumentos eficazes de controle social em torno do conjunto de aÃÃes segregacionistas de cunho espacial, que visam à obtenÃÃo de lucro e o consequente privilÃgio dos setores imobiliÃrios dominantes. Averiguei que a polÃtica de turismo està ancorada em um modelo de desenvolvimento urbanÃstico mercantil, inserido no cenÃrio de investimentos de capitais pÃblicos e privados, nacionais e internacionais, o que revela a intercessÃo entre o segmento de NegÃcios & Eventos e o setor imobiliÃrio, gerando novas configuraÃÃes espaciais, uma vez que esta modalidade de turismo tem por base as obras ligadas aos grandes eventos e a investimentos em infraestrutura viÃria e de lazer. / This dissertation, titled Specter of the Cable-stayed Bridge and the Observation Tower amid the Circuit of Business Tourism and Events, aims at understanding, with evaluation of public policies, a conception of touristic entrepreneurship for the city of Fortaleza through construction of urban icons, linked to the sectors that deal with it, notably the Business and Events Segment. The specific goal of this evaluation is the proposal by the Government of the State of Cearà to build the Cable-stayed Bridge and the Observation Tower as an urban icon to attract new flows of financial capital and investments directed to the sector of tourism. In spite of the non-materiality of the works, their specters support political relevance, since they were constituted within new configurations of Business Tourism & Events and agree with the prevailing lines of public policies of tourism in the State of Cearà of the last decades. The main effort of the analysis is to present a critique of the intrinsic logic applied to the conception of development of the city, starting from investments in tourism for construction of new equipment, still marked by strong State intervention that privileges the private sector, by remodeling city environs under the aegis of capital accumulation. Inspired by the "In Depth Assessment Modelâ developed by Rodrigues (2008), which in its construct establishes systematic rules of investigation, based on axes of analysis that guide investigative practices in the area, this dissertation reveals evaluation efforts attached to the first three analytical axes as designed by the author (content analysis of the program, context of policy formulation and institutional trajectory). This work resorted to official documents and unstructured interviews, the latter being the main investigative technique, and leading to predominantly a qualitative research. As an upshot of this option, the research plan transcended the analysis of quantitative data collected in standardized formats or in linear approaches. As a result of this evaluation, one tends to understand the metropolis as a place where urban transformations and opening of spaces march with capital reproduction and total preponderance of urban works and projects in the face of the lack of effective instruments of social controls around the set of spatial segregationist actions for obtaining profit and the consequent privilege of dominant real estate sectors. It was noticed that tourism-related policies anchor in a model of commercial urban development, inserted in the scenario of investments of public and private, national and international capital, which reveals intercession of the Business & Events Segment and the real estate sector, generating new spatial configurations, since this modality of tourism focus on works linked to major events and investments in road and leisure infrastructure.
233

Análise numérica e experimental do efeito dinâmico do vento em torres metálicas treliçadas para telecomunicações. / Experimental and numerical analysis of the dynamic wind effect on freestanding latticed telecommunication tower.

Célio Fontão Carril Júnior 21 August 2000 (has links)
Torres metálicas treliçadas tem sido largamente utilizadas como suporte de antenas de microondas. Devido ao baixo peso e a inexistência de terremotos significativos no Brasil, a força de vento é o fator determinante do projeto destas estruturas. Com o objetivo de determinar estas forças e seus efeitos em torres treliçadas foram realizadas investigações numéricas e experimentais. Uma torre de 100 metros foi dimensionada com base nos padrões existentes no Brasil. Examinou-se a resposta dinâmica da estrutura ao longo do vento. Investigaram-se a resposta ressonante, não ressonante e o fator resposta de rajada. Concluiu-se que a resposta ressonante não é significativa para este tipo de estrutura. Compararam-se os modelos de DAVENPORT (1993), da norma Brasileira NBR6123/88 e o processo do vento sintético de FRANCO (1993). Uma investigação experimental foi realizada para analisar os coeficientes de força em uma seção da torre estudada. Os experimentos foram realizados no “Boundary Layer Wind Tunnel Laboratory” (BLWTL) da “University of Western Ontario” (UWO), Canadá. Foram analisados o ângulo de incidência do vento; o índice de área exposta; o efeito de proteção; o fator de interferência no coeficiente de arrasto de antenas de microondas, devido à proximidade da torre e a influência da turbulência do vento. Os resultados mostraram boa concordância com os valores obtidos em diferentes normas existentes. / With today’s expanding communication systems, a large number of lattice towers to support cellular and microwave antennas are being constructed in Brazil. Due to the lightweight of these structures, wind forces are the primary concern in the design. With the objective of determining these forces and their effects upon latticed towers, a numerical and experimental investigation is accomplished. A 100-meter tower is designed based on existing patterns of latticed towers in Brazil. The along wind dynamic response is analysed. The resonant, background response and gust factor are examined. It is concluded that the resonant response is not significant for this type of structure. The DAVENPORT (1993) method, the Brazilian code NBR6123/88 and the process of the synthetic wind of FRANCO (1993) are compared. An experimental investigation is accomplished to analyse the force coefficients on a section of the lattice tower studied. The tests were performed at the Boundary Layer Wind Tunnel Laboratory, University of Western Ontario (UWO), Canada. The wind incidence angle; the tower solidity; the shielding effect; the interference factor upon the drag coefficient of the microwave antennas, due to the tower proximity and the influence of the wind turbulence are analysed. The results are ii good agreement with the values obtained in different existent codes.
234

Modelagem matemática de reator para produção de álcoois graxos etoxilados. / Mathematical modeling of the ethoxylated alcohols reactor.

Gisele Milanello do Amaral 24 August 2007 (has links)
Foi desenvolvido modelo matemático para o processo de produção de álcoois etoxilados em um reator batelada com spray da fase líquida na fase gasosa. O modelo considera a cinética da polimerização iônica e a transferência de massa de óxido de eteno entre as fases gasosa e líquida. A cinética foi estudada a partir de dados previamente obtidos em laboratório. Para modelagem da transferência de massa, foram utilizados dados de bateladas industriais. Foram testados vários modelos de transferência de massa encontrados na literatura, sendo que o modelo que se mostrou mais adequado para este reator industrial foi o de gotas com circulação interna. A partir do modelo obtido da cinética e da transferência de massa, foi analisada a influência de parâmetros de projeto, como a vazão de recirculação de líquido, a relação entre a altura e o raio do reator e o tipo de spray na produtividade deste. Observou-se que a maior vazão de recirculação aumenta a produtividade do reator, assim como o aumento da altura do reator. O tipo e o diâmetro da gota do spray também influenciam a produtividade do reator. / A mathematical model for the production of ethoxylated alcohols in a spray tower loop reactor was developed. The model considers the reaction as an ionic polymerization and the ethylene oxide mass transfer from the vapor phase to the liquid phase. The kinetics was obtained from a laboratory scale reactor data. The mass transfer model was obtained from the industrial reactor data. Several models for the mass transfer of ethylene oxide from gas phase to the liquid droplets were tested, and it was found that the most appropriate mass transfer model for this industrial reactor was the internally well-mixed drop model. From the kinetics and the mass transfer model, the influence of the pump recirculation flow rate, the ratio between the reactor height and radius and the spray performance was analyzed. The results show that higher reactor productivity can be obtained using higher recirculation flow and higher reactor height. The spray nozzle performance and the drop diameter also influence the reactor productivity.
235

Estudo do processo fermentativo continuo para produção de etanol utilizando celulas auto-imobilizadas em reatores tipo torres / Study of continuous fermentation process for ethanol production using self-immobilized cells in fixed bed tower reactors

Galassi, Gabriel Ramos 29 June 2007 (has links)
Orientador: Silvio Roberto Andrietta / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-10T10:19:18Z (GMT). No. of bitstreams: 1 Galassi_GabrielRamos_M.pdf: 1009774 bytes, checksum: 86a841b010532edff0ac4939c19472f4 (MD5) Previous issue date: 2007 / Resumo: Este trabalho tem por objetivo a realização de um estudo aprofundado do processo de fermentação alcoólica contínua em que são utilizados reatores tubulares tipo torre e células auto-imobilizadas. Buscou-se nesse projeto a seleção entre quatro cepas com características floculantes e perfis metabólicos adequados ao trabalho em tais reatores. O anseio por melhorias no sistema de fermentação contínua com células auto-imobilizadas se dá em função da busca por métodos com reduzido custo de produção do etanol, o que ocorre nesse sistema, onde inexiste a necessidade da utilização de unidades de separação de células (centrifugas), reduzindo assim em torno de 15% o custo final do preço do produto acabado. As linhagens utilizadas foram quatro cepas do gênero Saccharomyces cerevisiae com características floculantes e formadoras de partículas esféricas (pellets) quando cultivadas em mesa agitadora circulatória. Duas dessas cepas selecionadas foram obtidas da unidade de fermentação industrial da Usina Junqueira (Igarapava/SP), isoladas durante a safra de janeiro de 2000, são elas as cepas JU C2 e JU C4, outras duas cepas foram obtidas através de recentes isolamentos no Departamento de Biotecnologia e Processos do CPQBA/Unicamp, cepas G1 e G2. No processo de otimização foram utilizados dois reatores tubulares em série, um primeiro reator (R1) recebia um substrato concentrado de sacarose, diluído em linha visando atingir concentrações pré-determinadas para o uso nos experimentos e um segundo reator (R2) que recebia o efluente (vinho fermentado) proveniente de R1. Foram realizados quatro experimentos, cada qual com uma linhagem diferente. Os experimentos tiveram entre 20 a 25 dias de duração cada, porém, para fins de padronização foram selecionados 12 dias de ensaios. Durante os experimentos, diferentes vazões de alimentação aos reatores foram testadas, estas alternaram de forma crescente entre 1,2; 1,5; 1,8 e 2,1 L/h de substrato. Amostras foram retiradas do sistema e analisadas quanto à quantidade de sólidos solúveis, quantidade de ART, etanol produzido e vazão real do sistema. Ao término de cada experimento foram realizadas análises de cariotipagem, potencial de floculação por absorbância e determinação da floculação pela expressão dos genes FLO5 e FLO10. De forma geral, todas as linhagens estudadas mostraram-se hábeis ao trabalho em biorreatores fluidizados, desde que sejam respeitados seus limites metabólicos atuando nesse tipo de reatores. As linhagens JU C4 e G1 sobressaíram-se entre as demais pelo comportamento flexível e adaptável diante das situações impostas ao longo do projeto. Foram capazes de formar leitos celulares estáveis e com bom desempenho na conversão de açúcares á etanol. As linhagens JU C2 e G2 apresentaram também bons resultados na produção de etanol, no entanto, seus perfis como linhagens floculantes exigem uma maior cautela na utilização das mesmas em processos fermentativos. JU C2 com baixo poder floculante, formando por vezes leitos pouco estáveis e G2 com grande poder floculante, formando por vezes leitos compactos com canais preferenciais de passagem de substrato / Abstract: using flocculation yeasts of Saccharomyces cerevisiae in fixed bed tower reactors for ethanol production. We sought, through this job, the selection between four flocculent yeasts strains with appropriate metabolic profile to work in this kind of reactor. The selected yeasts strains present strong flocculent characteristics and there is no need to use cell separation unity (centrifuge) after the fermentation process reducing around 15% the costs of ethanol production. Two of these strains, JU C2 and JU C4, were collected from an industrial fermentation unity at Usina Junqueira (Igarapava/SP) during the crop of 2000. The other two strains, G1 and G2, were collected from CPQBA/Unicamp. In the operational optimization were used two fixed bed type tower reactors connected in series, a first one (R1) receive a concentrated sucrose medium diluted in line for reach predetermined concentrations and a second one (R2), that receive fermented wine from the first (R1). The fermentations experiments had between 20 or 25 days, but for standardization of the work 12 days of assays were selected. During the experiments, different feed outflow were tested in the reactors, these had been alternated in a increasing way between 1,2; 1,5; 1,8 and 2,1 L/h of medium. Samples were collected from the system and analyzed the amount of soluble solids, amount of reducing sugars, ethanol and real outflow of the system. In the ending of each experiment were analyzed the karyotyping profile and flocculating potential by absorbance method and expression of the FLO1 and FLO10 genes. The results confirm that all the studied strains are able to work in fluidized bioreactors since their metabolic limits where respected. The best results were obtained with JU C4 and G1 strains. They show a flexible and adaptable behavior ahead the tested situations in this job. They were capable to form steady beds and demonstrate good performance in sugar conversion to ethanol. The other strains, JU C2 and G2, showed nice results in the production of ethanol, however their flocculent profiles demand caution when used in fermentation processes. JU C2 has a low flocculent power forming sometimes unstable cell beds and G2 has a high flocculent power forming sometimes compact cell beds with preferential channels of medium passage / Mestrado / Desenvolvimento de Processos Biotecnologicos / Mestre em Engenharia Química
236

Estudo teorico e experimental de uma torre de nebulização para absorção de SO2 / Theoretical and experimental study of spray tower for absorpion of SO2

Codolo, Milene Costa 22 February 2006 (has links)
Orientador: Waldir Antonio Bizzo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-09T18:51:04Z (GMT). No. of bitstreams: 1 Codolo_MileneCosta_M.pdf: 1600775 bytes, checksum: 69ec6ddb7de37e176139ccd08583c483 (MD5) Previous issue date: 2006 / Resumo: Este trabalho estuda a absorção de SO2 em uma torre de nebulização contra-corrente. Um estudo experimental foi realizado, a fim de determinar a influencia das variáveis do processo de absorção. As variáveis estudadas foram: velocidade do gás, vazão de líquido, concentração de SO2 no gás na entrada e a relação líquido/gás. Também foi analisada a formação do filme de líquido ao longo da torre, proveniente da colisão das gotas com a parede do equipamento. A análise do filme de líquido foi importante para determinar a vazão das gotas ao longo da torre. Além do estudo experimental foi desenvolvido neste trabalho um modelo para simular a transferência de massa em uma torre de nebulização para remoção de SO2. Foi analisada a transferência de massa tanto nas gotas quanto no filme de líquido. O modelo foi desenvolvido para prever a concentração de SO2 no gás na entrada da torre, pois a concentração de SO2 na saída foi imposta. O modelo mostra a principal área de absorção na torre, a influência do diâmetro da torre, a influência da velocidade da gota na absorção de SO2 e dados do modelo foram comparados com dados experimentais / Abstract: This work studies the absorption of sulfur dioxide in a counter-current spray tower. An experimental study was carried out to analyzer the process parameters of the absorption of sulfur dioxide. The parameters studied were: gas velocity, liquid flow, sulfur dioxide concentrations in the gas feed and liquid/gas rate. It was also analyzed the formation of liquid film, from the collision of drops on the wall tower. The analyzed liquid film was used to determined de liquid flow as drops along the spray tower. Besides an experimental study it was developed in this work a model to simulate the mass transfer in a spray tower to removal sulfur dioxide. Both mass transfer in the drops and mass transfer in the liquid film were analyzed. The model has been developed to predict the SO2 concentrations in the gas feed, therefore the SO2 concentrations in the gas exit was determined. The model shows the main area of absorption, the influence drop diameter, the influence of drop velocity in the absorption of SO2 and data from model were compared with experimental data / Mestrado / Termica e Fluidos / Mestre em Engenharia Mecânica
237

Sistema de captaÃÃo de energia solar para uma torre de dessalinizaÃÃo tÃrmica com recuperaÃÃo de calor / System of captation of solar energy for a tower of thermal dessalinizaÃÃo with heat recovery

RÃgio Davis Barros Alves 02 September 2009 (has links)
CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / This dissertation presents the experimental result of a system to absorb solar energy to heat up a desalination tower with heat recovery mechanism and a change made in the heated water distribution at the heat storage tank. The system to absorb solar energy consists of solar thermal flat plate collectors for high temperatures and it responsible for the conversion of solar radiation in thermal energy to heat up the water to be desalinated. The change made in the storage tank consists of the installation of a stainless steel pipe with holes equally spaced and arrangement to allow a better distribution of the hot water from the solar collectors in the heat storage tank. The desalination unit has two components: two high temperatures solar collectors and a desalination tower with six stages. In its operation, water is heated in the solar collectors and moves by natural convection to the storage tank, to the bottom of the tower. In the tank, the water transfers heat to the salty water in the first stage of the tower. This heated water transfer heat by evaporation, convection and radiation to the second stage and part of its energy is lost to the ambient. The condensed vapor on the walls of the stages flows down by gravity to be collected in a reservoir installed under the desalination tower. The heat received by the second stage is used to heat up the ater in this stage and the process is repeated in all stages. The performance of the desalination unit was satisfactory. The temperature in the storage tank reached values near 85ÂC and the water temperatures at the outlet of the solar collector were near 100ÂC. The daily production was 31 liters of desalinated water and the GOR-value (gain output ratio) was 1,54
238

La relation gestes-parole dans la planification de la résolution du problème de la Tour de Hanoï chez des enfants, adolescents et adultes colombiens / The gesture-speech relationship in planning the solving of the Tower of Hanoï problem by Columbian children, adolescents and adults

Moreno Torres, Mayilin 09 December 2014 (has links)
Lorsque nous parlons, nous bougeons nos mains, nous faisons des gestes. Les gestes aident à communiquer avec les autres mais aussi à mieux exprimer notre pensée. Les gestes et la parole sont donc deux dimensions qui s’intègrent dans un système de communication unifié, reposant sur des représentations cognitives communes : quand un locuteur produit un message, la plupart des informations qu’il veut partager est certes véhiculée par le discours, mais également par les gestes (McNeil, 1992). Parfois, cette information entre les gestes et la parole est non-concordante. Garbert et Goldin-Meadow (2002) ont montré que lorsque les participants expliquent leur résolution de la tâche de la Tour de Hanoï, ces non-concordances entre l’information transmise par les gestes et celle transmise par la parole, peuvent se produire soit aux moments incertains, preuve que les participants hésitent entre plusieurs stratégies de résolution soit aux moments-clés, indiquant la capacité à planifier deux stratégies de résolution, l’une par les gestes, l’autre par la parole. La planification à travers les « mismatches » gestes-parole n’a pas été étudié malgré les nombreuses recherches de Goldin-Meadow à ce sujet. Nous avons mené une étude en Colombie auprès de 144 participants issus de deux milieux socio-économiques contrastés. Nous avons tenté de combler cette lacune en étudiant les effets de l’âge, du milieu socio-économique et de la complexité de la tâche de la Tour de Hanoï sur les non-concordances gestes-paroles lors des explications anticipant sa résolution. Nos résultats suggèrent l’existence d’un effet de la complexité de la tâche et des effets limités de l’âge et du milieu socio-économique. / When we speak, we move our hands, we make gestures. Gestures help to communicate with others but also to better express our thoughts. Gestures and speech are two dimensions that are part of a unified system of communication based on shared cognitive representations: when a speaker produces a message, most of the information he wants to share is certainly conveyed by speech, but also by gestures (McNeil, 1992). Sometimes this information between gestures and speech is discordant. Goldin-Meadow and Garbert (2002) showed that when participants explain their resolution of the Tower of Hanoi task, the mismatch between the information conveyed by the gesture and the information transmitted orally, may occur either at key moments, indicating the ability to provide two problem-solving strategies, or at uncertain times, showing that participants are torn between several solving strategies. We conducted a study in Colombia among to 144 participants from two contrasting socio-economic backgrounds. The study of the development of planning through the gesture-speech "mismatch" remains understudied despite wide research conducted by Goldin-Meadow. We tried to fill this gap by examining the effects of age, socio-economic background and the complexity of the Tower of Hanoi task upon gesture-speech “mismatches” regarding explanations anticipating the resolution. Our results suggest the existence of an effect of the complexity of the task and limited age and socio-economic background effects.
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Modelagem de torres de transmissão utilizando análise numérica dos campos eletromagnéticos e funções racionais / Transmission towers modeling using numerical analysis of electromagnetic fields and rational functions

Pinto, André Jinno Gomes, 1983- 24 August 2018 (has links)
Orientadores: José Pissolato Filho, Eduardo Coelho Marques da Costa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de Computação / Made available in DSpace on 2018-08-24T10:02:40Z (GMT). No. of bitstreams: 1 Pinto_AndreJinnoGomes_D.pdf: 9708757 bytes, checksum: 84772389fed6b8c0c68adcdd4db7cd9b (MD5) Previous issue date: 2014 / Resumo: A análise do comportamento dinâmico da torre de transmissão de energia elétrica e torres de telecomunicações é de interesse nos estudos de proteção relacionados com descargas atmosféricas. Normalmente, a impedância de surto da torre no domínio do tempo é usada para caracterizar o comportamento dinâmico da torre. A principal desvantagem na definição de tais impedâncias de surto é a dependência da forma de onda de excitação, e não há consenso sobre a forma de onda de corrente a ser usada. Além disso, não há concordância sobre uma definição única da tensão envolvida. A fim de contornar tais limitações e problemas, o modelo aplicado ao estudo faz uso das análises no dominio da frequência, onde a impedância de surto da torre depende somente da geometria da estrutura e das características eletromagnéticas do meio. Ademais, as limitações associadas com as abordagens simplificadas são enfatizadas no decorrer do presente trabalho. Os resultados apresentados fazem uso de ferramentas computacionais como o código NEC-2 (Numerical Electromagnetic Code) que se baseia na análise numérica da dinâmica do campo eletromagnético. Com a utilização desse código, correntes são geradas e posteriormente utilizadas para o cálculo da impedância de surto da torre. Posteriormente, é gerado um circuito RLC representativo das características da estrutura metálica, obtidas pelo método de vector fitting que aproxima a função impedância de surto da torre por funções racionais. Por fim, o circuito RLC gerado pode ser aplicado nas análises diretamente no domínio do tempo com o uso de programas computacionais como o EMTP (Electromagnetic Transients Program), sem a necessidade do uso de transformadas para alterar o domínio de análise / Abstract: The dynamic analysis of the behavior in power transmission towers and telecommunications towers is of interest in studies related to lightning protection. Normally, the surge impedance of the tower in the time domain is used to characterize the dynamic behavior of the tower. The main disadvantage of these definition of surge impedances is the dependence on the waveform of excitation, and there is no consensus on which current wave to be used. Furthermore, there is no agreement on a single definition of the voltage involved. In order to overcome such limitations and problems, the model applied to the study makes use of the analysis in the frequency domain, where tower¿s surge impedance depends only on the geometry of the structure and electromagnetic characteristics of the medium. Moreover, the limitations associated with the simplified approaches are emphasized in the course of this work. The results presented make the use of computer code as NEC-2 (Numerical Electromagnetic Code) based on the numerical analysis of the electromagnetic field dynamics. Using this code, currents are generated and then used to calculate the surge impedance of the tower. Subsequently, an RLC circuit is generated representating the characteristics of the metal structure, obtained by vector fitting method, that approximates the surge impedance function of the tower by means of rational functions. Finally, the generated RLC circuit can be applied directly in analyzes in the time domain using computer programs such as EMTP (Electromagnetic Transients Program) without the need of using transforms to change domain analysis / Doutorado / Energia Eletrica / Doutor em Engenharia Elétrica
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Nosná konstrukce rozhledny / Load-bearing structure of lookout tower

Leško, Adam Unknown Date (has links)
Diploma thesis deals with the design and assessment of load-bearing structure of lookout tower in locality of Spálava peak in Železné hory. Structure is designed on fourt-pointed star ground plan with dimensions 12 x 12 meters. Lookout tower is 35 meters high, the viewing platform is at a height of 30 meters. Structure is designed as a spacial truss. Most load-bearing elements are made of solid or glued laminated timber. The central column is made of steel.

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