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A study on the deformation behaviour of the cathode collector bar at high temperature and low levels / Study on the deformation behavior of the cathode collector bar at high temperature and low levelsFakoya, Femi Richard 20 April 2018 (has links)
L'étude de la déformation de la barre collectrice dans les conditions subies au sein de la cellule de réduction d'aluminium est d'une grande importance pour l'optimisation de l'efficacité et l'augmentation de la durée de vie de la cellule. Ce mémoire nous informe des résultats d'un programme expérimental réalisé sur une barre de collectrice en acier. Le but, est d' étudier son comportement en tenant compte de ses propriétés thermiques, mécaniques et de fluage. Des essais ont été effectués en compression à de basses tensions, de 0,5 à 2MPa et à une température élevée, de 900°C. Différents comportements ont été observés à de faibles contraintes, jusqu'à 2MPa, cela peut être justifié par le temps et le niveau de pression appliqué. L'inspection métallographique a montré l'apparition d'oxydation et de la corrosion sur des échantillons testés, ceci est dû à l'environnement agressif des conditions du test. D'importants efforts et modifications ont été fournis pour éradiquer cet effet et pour améliorer l'exactitude des données de test de fluage obtenus. / The study of the deformation behaviour of the collector bar at conditions experienced within the aluminium reduction cell is of great importance to optimizing the efficiency and increasing the life span of the cell. This mémoire communicates the results of an experimental program carried out on the steel collector bar material (AISI 1006) to investigate its behaviour in relation to its thermal, mechanical and the creep properties. Tests were carried out in compression at low stresses, 0.5 to 2 MPa and high temperature, 900 °C. Different behaviour was observed at low stresses up to 2 MPa, which can be characterised by time and applied stress level. Metallographic inspection showed effect of oxidation and corrosion on tested samples due to the aggressive environment of the test condition, major efforts and modification were made to eradicate this effect and to improve the accuracy of obtained creep test data.
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Proposition d’un cadre conceptuel d’arrimage des savoirs géographiques locaux dans les macro-observatoires : cas de la région DIANA MadagascarRandrianarivelo, Mamy Dina 20 April 2018 (has links)
Le recours aux données géographiques issues des macro-observatoires s’impose comme la solution incontournable pour les agences de développement et bailleurs de fonds internationaux en quête de données structurées et facilement accessibles. Ces données sont pourtant conçues selon une vision globalisante qui ne reflète pas ou pas suffisamment les contextes spécifiques locaux sur lesquels ces acteurs doivent intervenir. Dans les pays du Sud en particulier, les savoirs géographiques locaux constituent le plus souvent la seule source de données terrain disponible. Mais leur fiabilité et leur utilité sont souvent questionnées, en comparaison des données statistiques ou cartographiques des macro-observatoires. En effet, ils ne sont que peu ou pas formalisés. Ils nécessitent des processus de collecte de terrain complexes à mettre en œuvre. Leur interprétation est souvent difficile, en particulier pour les acteurs occidentaux. Ce travail de recherche a pour objectif la conception d’un cadre d’intégration des savoirs géographiques locaux dans les macro-observatoires. Il repose concrètement sur l’observation, l’analyse et la mise en relief des points communs et des différences des deux types de savoirs géographiques, à partir du cas de la région de DIANA à Madagascar; et plus précisément des savoirs locaux issues d’une démarche de Zonage À Dire d’Acteurs (ZADA) et des données globales de l’observatoire « Harvest Choice » de l’International Food Policy Research Institute (IFPRI). Mots-clés : Macro-observatoires, données locales, données globales, infrastructure de données spatiales, intégration des données, connaissances locales, connaissances experts, SIG.
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Évaluation et analyse de l'initiation de la corrosion dans des éléments de béton arméBarrera, Eduardo 20 April 2018 (has links)
L’objectif général du projet est de valider l’existence d’un effet d’échelle liant temps d’initiation de la corrosion à la taille des éléments en béton armé. Dix-huit poutres ont été fabriquées avec les mêmes caractéristiques, soit : la même section transversale, le même gâchage de béton, le même lot d’acier, la même épaisseur de béton de recouvrement et les mêmes conditions de cure. Le seul facteur qui diffère entre les poutres est la longueur. Six poutres ont été construites avec une longueur de 0,60 m, six de 1,80 m et six de 3,00 m. Les éléments ont été exposés à un environnement salin (3% de NaCl) avec des cycles de mouillage de 2,5 jours et de séchage de 4,5 jours. Il a été confirmé que la taille des éléments en béton armé a une influence sur le temps d’initiation de la corrosion. Ce dernier diminue lorsque la taille de l’élément augmente. / The main objective of the study was to validate the existence of a scale effect of the initiation corrosion time related to the size of the reinforced concrete elements. Eighteen beams were poured with the same characteristics: same cross-section, same concrete pouring, same steel batch, same thickness of concrete and same curing conditions. The only difference between the beams was their length. Six beams were built to the length of 0.60 metres, six to 1.80 metres and six to 3.0 meters. The elements were exposed to a saline environment (3% of NaCl) with wetting cycles of 2.5 days and drying cycles of 4.5 days. It was confirmed that in the work conditions of the project, the size of the reinforced concrete elements has an influence on the corrosion initiation time. The initiation time decreases as the size of the element increases.
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Postoje obyvatel RF k zimním olympijským hrám v Soči 2014 / Attitudes of Russian Population to Winter Olympic Games in Sochi 2014Khrushchev, Kirill January 2012 (has links)
Title: Attitudes of Russian Population to Winter Olympic Games in Sochi Objectives: The main objective of this thesis is to determine attitudes of Russian population and residents of Sochi to XXII Winter Olympic Games. Another objective is to show advantages and disadvantages of hosting the Olympic Games and also to make recommendations, which can be used by government and sport institutions while organizing big sports events. Methods: Quantitative sociological research was made for the purpose of this thesis. Research was implemented by written, electronic and oral questioning .Obtained statistics were processed and analyzed. Results: All the findings are compiled into the tables and diagrams in the result part of this diploma work. Keywords: Sociological research, questionnaire, Olympic games 2014, Russia, Sochi
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Postoje obyvatel RF k zimním olympijským hrám v Soči 2014 / Attitudes of Russian Population to Winter Olympic Games in Sochi 2014Khrushchev, Kirill January 2013 (has links)
Title: Attitudes of Russian Population to Winter Olympic Games in Sochi Objectives: The main objective of this thesis is to determine attitudes of Russian population and residents of Sochi to XXII Winter Olympic Games. Another objective is to show advantages and disadvantages of hosting the Olympic Games and also to make recommendations, which can be used by government and sport institutions while organizing big sports events. Methods: Quantitative sociological research was made for the purpose of this thesis. Research was implemented by written, electronic and oral questioning .Obtained statistics were processed and analyzed. Results: All the findings are compiled into the tables and diagrams in the result part of this diploma work. Keywords: Sociological research, questionnaire, Olympic games 2014, Russia, Sochi
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Efeitos de poluição urbana na higroscopicidade dos aerossóis e na ativação de gotas em nuvens quentes na Amazônia no âmbito do experimento GoAmazon 2014/5 / Urban pollution effects on aerosols hygroscopicity and warm clouds droplets activation in Amazon in context of the GoAmazon 2014/5 experimentAraujo, Alex Sandro Alves de 05 May 2017 (has links)
As medidas do experimento Green Ocean Amazon (GoAmazon 2014/5 ) foram realiza- das nos arredores de Manaus, na região central da Amazônia, durante dois anos, com o objetivo de entender como o ciclo de vida dos aerossóis e das nuvens em condições naturais é influenciado pelas emissões urbanas. Neste contexto, o presente trabalho procurou estudar a higroscopicidade dos aerossóis em condições poluídas pela pluma de Manaus e discuti-la à luz do que era esperado em condições prístinas. A partir desses resultados experimentais, usamos um modelo adiabático de parcela de nuvem para estudar o impacto da poluição de Manaus na formação de nuvens quentes. Observamos altas concentrações de aerossóis vindos de Manaus, com média de Ncn = 2.425 cm 3 e percentis de 25 % e de 75 % respectivamente dados por 937 cm 3 e 3.259 cm 3 . Para a Amazônia prístina, os valores tipicamente encontrados são da ordem de Ncn 400 cm 3 . A higroscopicidade das partículas da poluição urbana é notavelmente baixa, com média de t = (0, 09 ± 0, 01) para todos os diâmetros investigados. Além disso, são altamente heterogêneas quanto à higroscopicidade. As partículas naturais da Amazônia têm higroscopicidade média da ordem de t 0, 14, não sendo tão heterogêneas quanto as partículas de Manaus. Aperfeiçoamos e utilizamos um modelo adiabático de parcela de nuvem para investigar de forma sistemática o impacto da pluma de Manaus nos primeiros estágios de formação das nuvens quentes. O modelo foi validado através da comparação com quatro casos exemplificados na literatura, vindos de modelos conceitualmente semelhantes, mas de implementações numéricas diferentes. Em nossas simulações, consideramos que o formato da distribuição de tamanho das partículas de aerossol poderia variar com a concentração total de partículas, ao irmos da situação limpa para a poluída. Além disso, consideramos também que a higroscopicidade variava com a concentração total e com o tamanho das partículas de aerossol. Isto foi feito em etapas, permitindo representar as partículas de aerossol com crescente grau de detalhamento. Observamos que o número de gotículas na base da nuvem é determinado principalmente pela concentração de partículas e pela velocidade vertical. Em segundo lugar, vem o formato da distribuição de tamanho, e, depois, a higroscopicidade. Mostramos que simulações que não consideram estes outros fatores irão, necessariamente, superestimar o efeito dos aerossóis nas nuvens quentes. Da condição limpa para a condição poluída pela pluma, observamos o aumento da concentração gotículas e a correspondente diminuição do raio efetivo dessa população de gotículas. Observamos, também, a diminuição da fração de aerossóis ativados. Os resultados sugerem que, na condição poluída, as nuvens acumulam água líquida mais rapidamente em seus primeiros 200 m, em relação à condição limpa. / The measurements of the Green Ocean Amazon 2014/5 experiment were carried out on the outskirts of Manaus, in the central Amazon region, for two years, with the objective of understanding how the natural aerosol and cloud life cycles would be perturbed by urban emissions. In this context, the present work aimed at studying the aerosol hygroscopicity under polluted condition, comparing it with the pristine environment. Based on these results, we used an adiabatic cloud parcel model to study the impact of Manaus pollution on the first stages warm clouds formation. We observed high concentrations of aerosols coming from Manaus, with average Ncn = 2.425 cm 3 and percentiles 25 % and 75 % of 937 cm 3 and 3.259 cm 3 res- pectively. For the pristine Amazon, typical values would be about Ncn 400 cm 3 . The hygroscopicity of urban pollution particles were notable low, with average t = (0, 09±0, 01) for all diameters investigated, and a high level of heterogeneity was found. On the other hand, natural particles in the Amazon have a hygroscopicity of about t 0,14 and are not as much heterogeneous. We improved and used an adiabatic cloud parcel model to systematically investigate the impact of the Manaus pollution plume on the first stages of warm cloud develop- ment. The model was validated by comparison with four exemplary cases found in the literature, from conceptually similar models, but with different numerical imple- mentations. In our simulations, we considered that the shape of the size distribution could vary with increasing number concentration, as we moved from the clean to the polluted conditions. We also allowed the hygroscopicity to vary with the concentration and the diameter of the aerosol particles. These were done in stages, hence allowing an increasing level of complexity in the representation of the aerosol particles. We observed that the number of activated cloud droplets is as function primarily of the concentration and the vertical velocity. In second place comes the dependence with the shape of the size distribution and, after that, with the hygroscopicity. We showed that simulations that do not consider these other factors will, necessarily, over predict the effect of aerosols on shallow warm clouds. As expected, when we simulated clean conditions changing towards a polluted one, we found an increase in the number of activated droplets and corresponding decrease of effective radius of those droplets, and of the activated fraction. Our results suggest that, under polluted conditions, clouds accumulate liquid water more rapidly during the first stages of its development than under clean conditions.
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Análisis de la oferta de capacitación en los gobiernos locales de mayor índice de inseguridad de Lima Metropolitana para la atención de la problemática vinculada con la labor policial en materia de seguridad ciudadana, durante los años 2012, 2013 y 1er semestre 2014.Espinoza Barrientos, Fernando 07 April 2016 (has links)
Si se desea contar con una Policía altamente profesionalizada y eficaz, es preciso saber con exactitud cuáles son sus recursos humanos y qué grado real de capacitación poseen. Una vez conocidos estos datos, resulta necesario mejorar las técnicas de gestión de personal existentes, sabiendo que el bien social que la Policía produce está directamente generado por los hombres y las
mujeres que la integran. / Tesis
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Aplicación del modelo de gravedad para el análisis de los determinantes del flujo de importaciones peruanas de origen asiático en el período 2000-2014Urcia Erazo, María Cecilia 26 April 2017 (has links)
La investigación trata de explicar el comportamiento de las importaciones peruanas desde Asia, las cuales han presentado una dinámica interesante en los últimos quince años. A través del análisis econométrico en diferentes especificaciones del Modelo de Gravedad, se comprobó que el tipo de cambio real bilateral, los aranceles de Nación Más Favorecida y los costos del comercio internacional fueron los determinantes más importantes para explicar el flujo de importaciones totales desde 22 países de Asia en el periodo 2000 – 2014. A nivel desagregado, los ingresos del Perú afectaron más a la importación de bienes intermedios y de capital, el tipo de cambio real bilateral tuvo un impacto positivo y significativo para la importación de bienes de capital, y la Crisis Financiera de EE.UU. afectó más a la importación de bienes intermedios. Destaca además el impacto significativo de los costos del
comercio sobre los tres tipos de importación. El vínculo importador – proveedor asiático se puede seguir reforzando con mejoras en el desempeño logístico del Perú para facilitar el comercio y mayores vínculos con proveedores asiáticos de interés económico para diversificar el intercambio comercial. Se espera fomentar la investigación en las relaciones comerciales con el continente asiático, en especial enfocar a las importaciones no como una amenaza a la economía nacional sino como una oportunidad de generar mayor dinamismo en el intercambio comercial. / Tesis
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Πλευρική εξάπλωση στην παραλιακή ζώνη του Ληξουρίου και Αργοστολίου κατά τους σεισμούς της Κεφαλονιάς στις 26-1- & 03-2-2014Κεχαγιάς, Γιώργος 26 April 2015 (has links)
H πλευρική εξάπλωση είναι ένα εντυπωσιακό-καταστροφικό φαινόμενο,
επακόλουθο της ρευστοποίησης, που οδηγεί στην εδαφική αστοχία. Στην περίπτωση
κεκλιμένων εδαφών ή εδαφών που καταλήγουν σε ελεύθερο μέτωπο, προκαλείται
έντονη ρηγμάτωση της επιφάνειας του εδάφους και Πλευρική Εξάπλωση, Lateral
Spreading, (δηλαδή οριζόντια μετακίνηση) του εδαφικού υλικού (παραμορφώσεις
πολύπλοκης μορφής), στην περιοχή της όχθης υδάτινων ρευμάτων ή άλλων
θαλασσίων μετώπων και η εξάπλωση αυτών σε μεγάλη απόσταση προς τα ανάντι.
Αντικείμενο της παρούσας Διατριβής αποτελεί η μελέτη της εκτεταμένης
πλευρικής εξάπλωσης που πραγματοποιήθηκε υπό συνθήκες ελευθέρου μετώπου
προς την κατεύθυνση της ακτογραμμής στο Δυτικό Κρηπίδωμα του Λιμένα
Ληξουρίου και στην παραλιακή ζώνη του Αργοστολίου κατά τους σεισμούς της
Κεφαλονιάς στις 26-1-2014 (Mw=6.1) και στις 03-2-2014 (Mw=6.0).
Η Διατριβή περιλαμβάνει παρουσίαση των διαθέσιμων γεωτεχνικών
δεδομένων για το λιμένα Ληξουρίου και εκτιμήσεις του μεγέθους της πλευρικής
εξάπλωσης με βάση τα σύγχρονα εμπειρικά μοντέλα του Youd et al. (2002) και την
τροποποίηση αυτού, Youd et al. (2013). Γίνεται επίσης, σύγκριση της μετρηθείσας
οριζόντιας μετακίνησης με τις προβλέψεις των οριζόντιων μετακινήσεων των δύο
μοντέλων. Για τον έλεγχο της ρευστοποιησιμότητας του εδάφους -με χρήση του
αριθμού κτύπων NSPT - με σκοπό τον υπολογισμό του αθροιστικού ρευστοποιήσιμου
πάχους Τ15, χρησιμοποιήθηκε η μεθοδολογία των Idriss and Boulanger (2006).
Τέλος, παρουσιάζονται τα διαγράμματα μετρημένης οριζόντιας αθροιστικής
μετακίνησης - απόστασης από το ελεύθερο μέτωπο για την παραλιακή ζώνη του
Αργοστολίου. Λόγω έλλειψης γεωτεχνικών δεδομένων για το Αργοστόλι δεν έγινε
δυνατή η σύγκριση των μετρημένων τιμών με τις εκτιμηθείσες από εμπειρικά
μοντέλα. Ωστόσο, οι τιμές αυτές μπορούν να αποτελέσουν χρήσιμη προσθήκη στην
υφιστάμενη βάση δεδομένων για βελτίωση των εμπειρικών μοντέλων και καλύτερη
εφαρμογή τους στον ελλαδικό χώρο. / Lateral Spreading along the coastal line of Liksouri and Argostoli during the earthquakes in Cephalonia in January 26 & February 3, 2014.
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Impactos da volatilidade da taxa de câmbio no comércio da Colômbia com seus principais parceiros comerciais mediante um modelo gravitacional período 2004-2014Mosquera Agudelo, Paula Andrea January 2017 (has links)
Orientador : Prof. Dr.Maurício Vaz Lobo Bittencourt / Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciencias Sociais Aplicadas, Programa de Pós-Graduação em Desenvolvimento Ecônomico. Defesa : Curitiba, 10/03/2017 / Inclui referências : f. 66-75 / Resumo: O presente estudo tem como objetivo analisar o efeito da volatilidade cambial sobre o fluxo de exportações da Colômbia com os seus parceiros comerciais. O período compreendido no presente trabalho foi de 2004 a 2014 e o número de países considerados no estudo foi de 11. Para o desenvolvimento do estudo foram considerados os dados do comércio internacional entre a Colômbia e os seus parceiros comerciais, os quais foram desagregados no nível de dois dígitos do Sistema Harmonizado. Por outro lado, as variáveis foram inseridas dentro de um modelo gravitacional de comércio, cujos parâmetros foram estimados mediante as técnicas econométricas: Pooled, Dados em Painel (Efeitos Fixos) (Efeitos Aleátorios) e a técnica econométrica Poisson Pseudo Maximum (PPML) na forma de dados em painel. A inclusão e a exclusão das variáveis nas estimativas mostraram que a instabilidade cambial é prejudicial à relação comercial entre Colômbia e seus parceiros comerciais, já que maior incerteza cambial leva os agentes econômicos, a longo prazo, a reduzir suas atividades no comércio internacional, dada maior exposição ao risco. Palavras-chave: Volatilidade da taxa de câmbio; Equação gravitacional; Exportações. / Abstract: The present study aims to analyse the effect of exchange rate volatility on the export flow of Colombia with its commercial partners. The period comprised in the present study was from 2004 to 2014 and the number of countries considered in the study was twelve. In order to carry out this study, international trade data between Colombia and its trading partners were considered, which were broken down to the two-digit level of the Harmonized System. On the other hand, the variables were inserted within a gravitational model of trade, where parameters were estimated by two econometric techniques: Pooled, Fixed effect models, Random effect models and and Poisson Pseudo Maximum Likelihood (PPML) in the form of panel data. The inclusion and exclusion of the variables in the estimates showed that instability in exchange rates is detrimental to trade relationship between Colombia and its trading partners, since greater exchange rate uncertainty pushes economic agents, in the long run, towards reducing their international trade activities due to high exposure to risk. Keywords: Exchange rate volatility; Gravitational equation; Exports
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