Práca sa zaoberá mechanikou kontinua. Konkrétne je zameraná na lineárnu elasticitu homogénnych izotropných pevných telies. Pre dve rôzne kontinuá – klasické kontinuum a mikropolárne je odvodená silná aj slabá formulácia. Cosseratovo (mikropolárne) kontinuum predstavuje rozšírenie ku klasickému, kde je uvažovaný ďalší stupeň voľnosti - nezávislá rotácia. Mikropolárne kontinuum definuje ďalšie dve materiálové konštanty, ktoré súvisia s rotáciou. V súčasnosti je metóda konečných prvkov veľmi populárny spôsob približného riešenia rovníc lineárnej elasticity. Pre účely diplomovej práce bol vyvinutý program pre MKP riešenie 2D rovinných úloh. Pre lepšiu predstavu o vplyvu rôznych parametrov na správanie sa oboch kontinuí analyzujeme jednoduchý príklad konzolového nosníka. Riešenia analyzujeme s využitím 4-uzlového štvorhranného elementu, ktorý je jedným z najpoužívanejších pre MKP. V Cosseratovom kontinue by mali byť rotácie previazené skrz parameter vnútornej dĺžky, čo by sa malo odzrkadliť zvýšenou tuhosťou telesa. Úlohou práce je porovnať výsledky z oboch kontinuí a potvrdiť tento predpoklad.

Lyman continuum (LyC) photons are known to be responsible for reionising the universe after the end of the Dark Ages, which marked a period called the Epoch of Reionisation (EoR). While these high-energy photons are thought to predominantly originate from young, hot, massive stars within the earliest galaxies, and contributions from high-energy sources like quasars and AGN, the origins of these photons are yet not well known and highly debated. Detecting LyC photons from the early galaxies near the EoR is not possible as they get completely absorbed by the intergalactic medium (IGM) on their way to us, which has prompted the development of various indirect diagnostics to study the amount of LyC photons contributed by such galaxies by studying their analogues at low redshifts. In this study, we probe the ionised interstellar medium (ISM) of seven Green Pea galaxies through spatially resolved[O III] λ5007/[O II] λ3727 (O32) and [O III] λ5007/Hα λ6562 (O3Hα) emission-line ratio maps, using data from the Multi Unit Spectroscopic Explorer (MUSE) onboard the Very large telescope (VLT). Out of the two ratios, the former has proven to be a successful diagnostic in predicting Lyman continuum emitters (LCEs). Along with the line ratio maps, the surface brightness profiles of the galaxies are also studied to examine the spatial distribution of the emission lines and the regions from which they originate. The resulting maps indicate whether the ISM of the galaxies is ionization-bounded or density-bounded. Our analysis reveals that a subset of the galaxies with ionization-bounded ISM exhibits pronounced ionisation channels in the outer regions. These channels are potential pathways through which Lyman continuum photons may escape. For density-bounded ISM, the ionised ISM extends well beyond the stellar regions into the halos of the galaxies, highlighting their potential contribution to the ionising photon budget during the EoR. The findings emphasise the importance of spatially resolved ISM studies in understanding the mechanisms facilitating the escape of LyC photons.

The purpose of this study was to develop and test a measuring instrument based on the Gibb’s Defensive Communication Climate Paradigm (1961) to assess the communication climate focus of professional nurses in selected public hospitals in the Gauteng province. This focus involves the communication behaviour orientation of the professional nurses and their perceptions of the communication behaviour orientation of their operational managers. The Gibb’s model comprises six bipolar conceptual continuums, namely Evaluation-Description, Control-Problem orientation, Strategy-Spontaneity, Neutrality-Empathy, Superiority-Equality and Certainty-Provisionalism Continuums. The study consisted of a non-experimental design, including a developmental phase and a testing phase. During the developmental phase the researcher developed a measuring instrument (a Semantic Differential Scale questionnaire); used a simple, random sample method to pre-test the instrument; analysed the data by applying Cronbach’s Alpha reliability analysis and refined the instrument. Further refinement of this new instrument by future researchers is recommended. During the testing phase the researcher also used a simple, random sample, consisting of professional nurses (N = 270) from three selected public hospitals in Gauteng; tested the items against the biographical data and the three research questions and analysed the obtained data by utilising both descriptive and inferential statistics. A Delphi panel of experts were involved in both phases of the study. The results of the study indicated that although the respondents had a predominantly supportive communication behaviour orientation, they were more focused on the communication behaviour of their operational managers than on their own. Furthermore, the results indicated no significant differences in the influencing factors: age, tenure (periods in hospital), gender, language and institution (public hospital), in terms of the six conceptual continuums. Significant differences were found only in the factor: unit/ward, indicating that the supportiveness of the communication behaviour of professional nurses could be dependent on their specific work environment. Guidelines aimed at the development of a supportive climate were drawn up for the National Department of Health, Gauteng Department of Health, public hospitals, operational managers and professional nurses. It is recommended that implementation of the newly developed guidelines be pivotal for public hospitals, to refocus their communication climates towards supportive communication. / Health Studies / D. Litt. et Phil. (Health Studies)

Les traits fonctionnels sont de plus en plus utilisés en écologie pour expliquer les changements de composition et de structure de la communauté phytoplanctonique en fonction des contraintes environnementales. Ce succès tient au fait que les traits fonctionnels sont des caractéristiques reliées aux processus de croissance et de perte des organismes, et qu'ils déterminent ainsi l'occurrence, la dominance ou l'absence d'une espèce dans des conditions environnementales données. Parmi les traits fonctionnels, on distingue les traits morpho-fonctionnels qui présentent l'avantage d'être facilement observables et mesurables. Les approches basées sur les traits morpho-fonctionnels ont majoritairement été utilisées en lac mais pourraient toutefois s'avérer pertinentes en rivière où l'importance relative des contraintes environnementales agissant sur la communauté phytoplanctonique est très variable d'un système à l'autre. L'objectif de cette thèse a donc été de tester l'hypothèse selon laquelle la communauté phytoplanctonique en rivière pouvait être structurée selon les traits morpho-fonctionnels. Dans les rivières étudiées, nous avons montré que la communauté est structurée selon les traits morpho-fonctionnels reliés à la vitesse de sédimentation, en mettant en évidence le rôle clé de la forme des organismes, mais aussi de leur motilité et de leur densité via la présence de mucilage. A travers la sélection de différentes valeurs pour ces traits morpho-fonctionnels, nous avons pu mettre en évidence l'impact majeur de la turbulence sur la communauté phytoplanctonique de ces rivières. L'effet de ce paramètre a été testé expérimentalement en conditions contrôlées sur une communauté simplifiée afin de tester l'hypothèse selon laquelle sous l'effet de la turbulence, la composition de la structure de la communauté pouvait être prédite par les traits morpho-fonctionnels. Les résultats de cette approche expérimentale ont permis de réitérer le rôle clé de la forme dans la structure de la communauté corroborant ainsi les résultats de rivières et ont également souligné le rôle de la plasticité phénotypique. L'approche basée sur les traits a également été testée en estuaires, mais s'est cependant montré infructueuse. Plusieurs hypothèses ont été proposées pour expliquer ce résultat, notamment l'absence de trait identifié comme étant relié à la salinité. / Functional traits are increasingly used in ecology to explain changes in the composition and structure of phytoplankton community in relation to environmental constraints. Functional traits are related to growth and loss processes, and thus they determine the occurrence, dominance or absence of species in given environmental conditions. Among the functional traits, morpho-functional traits display the advantage of their ease to be measured. Approaches based on morpho-functional traits were mainly used in lakes, but could however be relevant in rivers where the relative significance of environmental constraints acting on the phytoplankton community varies from one system to another. The aim of this thesis was therefore to test the hypothesis that riverine phytoplankton community could be structured according to morpho-functional features. In the rivers studied, we showed that the community is structured according to morpho-functional traits related to sedimentation rate, highlighting the key role of the shape of organisms, but also of their motility and density via the presence of mucilage. Through the selection of different values for these morpho-functional traits, we highlighted the main impact of turbulence on the phytoplankton community within these rivers. The effect of this parameter has been tested experimentally on a simplified community under controlled conditions in order to test the hypothesis that as a result of turbulence, the composition of community structure could be predicted through morpho-functional traits. The results of this experimental approach helped to reiterate the key role of the shape in community structure thus corroborating the results found in rivers. It also stressed the role of phenotypic plasticity. This approach based on features was also tested in estuaries, but was, however, unsuccessful. Several hypotheses have been proposed to explain this result, including the lack of traits identified as related to salinity.

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Investigamos neste estudo a alternÃncia entre os modos verbais subjuntivo e indicativo em expressÃes dubitativas da lÃngua falada da Cidade do MÃxico, tambÃm conhecida como MÃxico, D.F. ou MÃxico, Distrito Federal. Valemo-nos do Corpus SociolinguÃstico de Ciudad de MÃxico, coletado e transcrito pelo Laboratorio de Estudios FÃnicos del Colegio de MÃxico (LEF-CM). O principal objetivo desse estudo à descrever o estado da variaÃÃo entre subjuntivo e indicativo em oraÃÃes independentes dubitativas, analisando os contextos favorÃveis e de restriÃÃo da variante subjuntivo e, assim, apontar se hà indÃcios de uma possÃvel mudanÃa em progresso na amostra analisada. Elencamos variÃveis linguÃsticas e sociais que, por hipÃtese, poderiam favorecer a variaÃÃo, outras que favoreceriam o indicativo e outras que favoreceriam o subjuntivo. Desse modo, concebendo a forÃa modal nÃo sendo exclusivamente encontrada na forma verbal, mas sim apreensÃvel no discurso e tambÃm, considerando um continuum do valor de certeza da modalidade irrealis, inerente aos enunciados dubitativos, buscamos mapear a frequÃncia de ocorrÃncia dos modos verbais em enunciados dubitativos, onde, segundo a normatividade, terÃamos preferencialmente o subjuntivo. Assim, almejamos identificar quais fatores condicionam o uso de subjuntivo ou de indicativo nessas construÃÃes. Os dados foram quantificados por meio do programa estatÃstico GOLDVARB X e analisados à luz da Teoria da VariaÃÃo e MudanÃa e de pressupostos funcionalistas, uma vez que ambas convergem no tocante à concepÃÃo de lÃngua como sistema heterogÃneo e passÃvel Ãs pressÃes de uso, consequentemente à variaÃÃo e à mudanÃa. Os resultados apontam as variÃveis item dubitativo e tempos verbais em alternÃncia como favorecedores do subjuntivo nessa variÃvel linguÃstica. Nesse sentido, observamos que hà uma especializaÃÃo no paradigma dos advÃrbios de dÃvida, consagrada e ratificada pelo uso, que atuariam, assim, como Ãndices da modalidade subjacente a esses enunciados, sendo o seguramente e o a lo mejor favorecedores do indicativo e de mais certeza do falante, enquanto o probablemente, o posiblemente e o quizÃ(s) favoreceriam o subjuntivo. Jà o grupo tempos verbais em alternÃncia nos indica que os tempos verbais de subjuntivo: presente, pretÃrito perfecto e pretÃrito imperfecto, sofrem a concorrÃncia da respectiva forma verbal de indicativo. O Ãnico tempo verbal que nÃo se mostra favorÃvel à variaÃÃo à o pluscuamperfecto de subjuntivo que se mostra contexto quase que categÃrico de subjuntivo com apenas uma ocorrÃncia de alternÃncia com a respectiva forma do indicativo. Em linhas gerais, sem desconsiderar a influÃncia sintÃtico-semÃntica, concebemos que no ato comunicativo a escolha do falante, situada no nÃvel pragmÃtico-dicursivo, propicia a codificaÃÃo de mensagens com sentidos diferentes da significaÃÃo que o item dubitativo ou o modo verbal prototipicamente possuem, com vistas a cumprir determinado propÃsito comunicativo. Nesse sentido, o julgamento epistÃmico do falante subjacente no discurso condiciona a seleÃÃo de itens dubitativos, que atuam como Ãndices da modalidade, e na seleÃÃo do modo verbal. Quanto Ãs variÃveis sociais, embora nÃo selecionadas pelo programa estatÃstico, os resultados mostram que os homens usam mais a forma subjuntiva que as mulheres e que os falantes com mais escolaridade usam mais o subjuntivo. / Investigamos en este estudio la alternancia entre los modos verbales subjuntivo e indicativo en expresiones dubitativas de lengua hablada de Ciudad de MÃxico, tambiÃn conocida como MÃxico, D.F. o MÃxico, Distrito Federal. Nos valemos del Corpus SociolingÃÃstico de Ciudad de MÃxico, colectado y transcripto por Laboratorio de Estudios FÃnicos del Colegio de MÃxico (LEF-CM). El principal objetivo de ese estudio es describir el estado de la variaciÃn entre subjuntivo e indicativo en oraciones independientes dubitativas, analizando los contextos favorables y de restricciÃn de la variante subjuntivo y, asÃ, apuntar si hay indicios de un posible cambio en progreso en la muestra analizada. Elegimos variables lingÃÃsticas y sociales que, por hipÃtesis, podrÃan favorecer la alternancia, otras que favorecerÃan el indicativo y otras que favorecerÃan el subjuntivo. De ese modo, concibiendo la fuerza modal como no siendo exclusivamente encontrada en la forma verbal, sino aprehensible en el discurso y tambiÃn, considerando un continuum del valor de certeza de la modalidad irrealis, inherente a los enunciados dubitativos, buscamos mapear la frecuencia de ocurrencia de los modos verbales en enunciados dubitativos, donde, segÃn la normatividad, tendrÃamos preferentemente el subjuntivo. De ese modo, anhelamos identificar cuÃles factores condicionan el uso de subjuntivo o de indicativo en esas construcciones. Los datos fueron cuantificados por medio del programa estadÃstico GOLDVARB X y analizados a la luz de la TeorÃa de VariaciÃn y Mudanza y de presupuestos funcionalistas, una vez que ambas convergen cuanto a la concepciÃn de lengua como sistema heterogÃneo y pasible a las presiones de uso, consecuentemente a la variaciÃn y a la mudanza. Los resultados apuntan las variables item dubitativo y tempos verbais em alternÃncia como favorecedoras del subjuntivo en esa variable lingÃÃstica. En ese sentido, observamos que hay una especializaciÃn en el paradigma de los adverbios de duda, consagrada y ratificada por el uso, que actuarÃan, asÃ, como Ãndices de la modalidad subyacente a esos enunciados, siendo el seguramente y el a lo mejor favorecedores del indicativo y de mÃs certeza del hablante, mientras el probablemente, el posiblemente y el quizÃ(s) favorecerÃan el subjuntivo. Ya el grupo tempos verbais em alternÃncia nos indica que los tiempos verbales de subjuntivo: presente, pretÃrito perfecto y pretÃrito imperfecto, sufren la concurrencia de la respectiva forma verbal de indicativo. El Ãnico tiempo verbal que no se muestra favorable a la alternancia es el pluscuamperfecto de subjuntivo que se muestra contexto casi que categÃrico de subjuntivo con apenas una ocurrencia de alternancia con la respectiva forma de indicativo. En lÃneas generales, sin desconsiderar el influjo sintÃctico-semÃntico, concebimos que en el acto comunicativo la elecciÃn del hablante, situada en el nivel pragmÃtico-discursivo, propicia la codificaciÃn de mensajes con sentidos diferentes de la significaciÃn que el Ãtem dubitativo o el modo verbal prototÃpicamente poseen, con vistas a cumplir determinado propÃsito comunicativo. En ese sentido, el juzgamiento epistÃmico del hablante subyacente en el discurso condiciona la selecciÃn de Ãtems dubitativos, que actÃan como Ãndices da modalidad, y en la selecciÃn del modo verbal. Con relaciÃn a las variables sociales, aunque no hayan sido seleccionadas por el programa estadÃstico, los resultados muestran que los hombres usan mÃs la forma subjuntiva que las mujeres y que los hablantes con mÃs escolaridad usan mÃs el subjuntivo.

O entendimento sobre os processos de fraturas em materiais à de grande importÃncia para a fÃsica e indÃstrias da construÃÃo civil. AtravÃs dos processos de fraturas podemos compreender melhor as propriedades elÃsticas dos materiais, como seu mÃdulo de Young macroscÃpico, tensÃo de ruptura e mÃdulo de rigidez. Podemos definir os processos de fraturas como sendo aqueles que dividem um sistema em duas ou mais partes, destruindo a conexÃo global dos elementos que o constituem. Nesse contexto, no primeiro capÃtulo à feito uma descriÃÃo matemÃtica das equaÃÃes da mecÃnica do contÃnuo, no segundo capÃtulo aborda-se o modelo de elementos discretos (DEM) que à um mÃtodo numÃrico capaz de descrever o comportamento mecÃnico de materiais granulados. No terceiro capÃtulo, construÃmos o modelo computacional para estudar, as propriedades mecÃnicas de 3 tipos de amostras, cristalina, amorfa e multifÃsica. O modelo computacional utilizado se mostrou bastante interessante e apresentou resultados que podemos considerar como sendo satisfatÃrios. / O entendimento sobre os processos de fraturas em materiais à de grande importÃncia para a fÃsica e indÃstrias da construÃÃo civil. AtravÃs dos processos de fraturas podemos compreender melhor as propriedades elÃsticas dos materiais, como seu mÃdulo de Young macroscÃpico, tensÃo de ruptura e mÃdulo de rigidez. Podemos definir os processos de fraturas como sendo aqueles que dividem um sistema em duas ou mais partes, destruindo a conexÃo global dos elementos que o constituem. Nesse contexto, no primeiro capÃtulo à feito uma descriÃÃo matemÃtica das equaÃÃes da mecÃnica do contÃnuo, no segundo capÃtulo aborda-se o modelo de elementos discretos (DEM) que à um mÃtodo numÃrico capaz de descrever o comportamento mecÃnico de materiais granulados. No terceiro capÃtulo, construÃmos o modelo computacional para estudar, as propriedades mecÃnicas de 3 tipos de amostras, cristalina, amorfa e multifÃsica. O modelo computacional utilizado se mostrou bastante interessante e apresentou resultados que podemos considerar como sendo satisfatÃrios. / The understanding about the fractures processes in materials has a big importance for physics and civil construction industries. Through the fractures processes, we can better understand the materialsâ elastics properties as its macroscopic Young module, rupture tension and rigidity module. We can define the fractures processes as those which divide a system into two or more parts, destroying the global connection of the elements that constitute it. In this context, in the first chapter, we can find a mathematical description of continuum mechanics equations. The second chapter discusses the model of Discrete Element(DEM), which is a numerical method capable of describing the mechanical behavior of granular materials. In the third chapter, we built the computational model for studying the mechanicals properties of three types of samples, crystalline, amorphous and multiphase. The computational model showed itself quite interesting and presented results which we can consider satisfactory. / The understanding about the fractures processes in materials has a big importance for physics and civil construction industries. Through the fractures processes, we can better understand the materialsâ elastics properties as its macroscopic Young module, rupture tension and rigidity module. We can define the fractures processes as those which divide a system into two or more parts, destroying the global connection of the elements that constitute it. In this context, in the first chapter, we can find a mathematical description of continuum mechanics equations. The second chapter discusses the model of Discrete Element(DEM), which is a numerical method capable of describing the mechanical behavior of granular materials. In the third chapter, we built the computational model for studying the mechanicals properties of three types of samples, crystalline, amorphous and multiphase. The computational model showed itself quite interesting and presented results which we can consider satisfactory.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-07-03T18:01:03Z No. of bitstreams: 1 BartolomeuMendonca.pdf: 7776338 bytes, checksum: 55d965cc65ca192d16d1b33d52fcccc4 (MD5) / Made available in DSpace on 2017-07-03T18:01:03Z (GMT). No. of bitstreams: 1 BartolomeuMendonca.pdf: 7776338 bytes, checksum: 55d965cc65ca192d16d1b33d52fcccc4 (MD5) Previous issue date: 2017-01-30 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / This thesis contests current and academic understanding of modernity as the expression of a civilized and superior humanity in all of its dimensions (social, political, economic, cognitive, moral) which would have in coloniality its unwanted side effect, and would allegedly have been overcome or is on its way to. Instead, it pursues to demonstrate that a conceptualanalytical inversion is possible: what has endured and is currently being deepened, is the coloniality that emerged in the fifteenth century, with the beginning of European empires great navigations towards the conquest of the new world – as they named it themselves; and modernity figures as economic, political, cognitive benefits, and so on, restricted to the settlers, or their reduced and dependent caste of subjects, the fruit of looting, theft, the death of coloniality’s victims, presently updated and deepened by the colonial heir elite. There is therefore the worldwide expression of coloniality (=modernity) which suggests the colonial continuum as an analytical proposition. To demonstrate the thesis of coloniality (=modernity) and the colonial continuum, the empirical situations of compulsory displacements were chosen, and the expropriation of territory, resources, products, knowledge and population government resulting from them. The colonial elite, as well as their inheritors, who have promoted primitive accumulation through despoliation, have at the same time profited from the expropriation and exploration of territories and the work force of Indigenous and African peoples and other peoples or traditional communities – currently the republic slaves. The debate over modernity, transmodernity, coloniality, development, progress, globalization, although controversial, has constituted the fundamental for the thesis main hypothesis: compulsory displacements due to planning, installation and operation of massive projects of intensive development in land, capital and workforce, which hierarchize human social groups, as well as their territories in civilized/barbarian or qualified/unqualified presently occur as unfoldings of a colonial modus operandi - by means of the colonial continuum. To demonstrate this hypothesis, as well as to furnish this thesis, besides drawing from a large academic production (ranging from contributions from Marx, 1985; Benjamin, 1987; Harvey, 2010; Foucault 2008; Ianni, 2000; to the those named post or de-colonial Latin Americans such as Dussel, 2005; Mignolo, 2003; Quijano, 1992), and speeches classified as common sense, contained in narratives, in conversations of people in traditional communities or presently circulating in pamphlets, newspapers and websites are also considered. The typical empiricists analysed who turn into privileged status of entities for inference were the RESEX communities in Tauá-Mirim, in Área Rural II, São Luis/MA, the Piquiá de Baixo community in Açailândia/MA, and the Projeto Pioneiro de Colonização in Buriticupu/MA. / Este trabalho de tese contesta a compreensão corrente e acadêmica sobre modernidade como expressão de uma humanidade civilizada e superior em todas as dimensões (social, política, econômica, cognitiva, moral) e que teria na colonialidade seu efeito colateral e indesejado, que supostamente já estaria superada ou em vias de superação. Ao contrário, procura demonstrar que é possível uma inversão conceitual-analítica, ou seja, que o que perdura e se aprofunda atualmente é a colonialidade, emergente a partir do século 15, com o início das grandes navegações dos impérios europeus rumo à conquista do, por eles mesmos denominado, novo mundo, e a modernidade figura como benefícios econômicos, políticos, cognitivos, etc. restritos aos colonizadores, ou a sua pequena e dependente casta de súditos, fruto do saque, do roubo, da morte das vítimas da colonialidade, atualizada e aprofundada, no tempo presente, pela elite herdeira colonial. Tem-se, portanto, a expressão mundial da colonialidade (= modernidade) que sugere, como proposta analítica, o continuum colonial. Para demonstrar a tese da colonialidade (= modernidade) e do continuum colonial elegeram-se as situações empírica dos deslocamentos compulsórios e das expropriações dos territórios, dos recursos, dos produtos, dos saberes e do governo das populações deles decorrentes. A elite colonial, bem como sua herdeira, que promoveram/promovem a acumulação primitiva e por espoliação, ao mesmo tempo se beneficiaram/beneficiam da expropriação e exploração dos territórios e da força de trabalho dos povos indígenas e africanos e outros povos ou comunidades tradicionais – hoje os escravos da república. O debate sobre modernidade, transmodernidade, colonialidade, desenvolvimento, progresso, globalização, apesar de controverso, constituiu a base para a principal hipótese desta tese: os deslocamentos compulsórios em razão do planejamento, instalação e operação de grandes projetos de desenvolvimento intensivos em terra, capital e trabalho, que hierarquizam os grupos sociais humanos, bem como os seus territórios, em civilizados/bárbaros ou qualificados/desqualificados ocorrem, atualmente, como desdobramentos do modus operandi colonial – pelo continuum colonial. Para demonstrar tal hipótese, bem como guarnecer esta tese, além de recorrer à larga produção acadêmica (que vai desde as contribuições de Marx, 1985; Benjamin, 1987; Harvey, 2010; Foucault, 2008; Ianni, 2000 até os denominados pós ou decoloniais latino-americanos como Dussel, 2005; Mignolo, 2003; Quijano, 1992), consideraram se, também, as falas classificadas como sendo senso comum, aquelas contidas nas narrativas, nas conversas das pessoas das comunidades tradicionais ou que circulam correntemente em panfletos, jornais, e sítios da internet. Os típicos empíricos analisados e que passam ao status privilegiado de entes para inferência foram as comunidades da RESEX Tauá-Mirim, na Área Rural II de São Luís/MA, a comunidade Piquiá de Baixo em Açailândia/MA; o Projeto Pioneiro de Colonização de Buriticupu/MA.

L'Équateur est le 5ème pays producteur de pétrole en Amérique du Sud. Les étapes d'extraction et de raffinage génèrent des déchets contentant des métaux co-émis avec les hydrocarbures aromatiques polycycliques (HAPs), connus pour leurs effets cancérogènes et toxiques chez l'homme. Dans ce contexte et dans le cadre du programme ANR MONOIL, le premier objectif de cette thèse était de déterminer la distribution des métaux dans l'environnement sur les provinces d'Orellana et Sucumbíos (zones d'extraction du pétrole en Amazonie, " NAR ") et dans la ville d'Esmeraldas (raffinerie, sur la côte Pacifique," NPC "). Le 2ème objectif était d'étudier le transfert des métaux depuis le sol ou l'air vers les cacaoyers, largement cultivés en Equateur, et d'en déterminer les impacts sur la santé après ingestion. Enfin, le 3ème objectif était de surveiller la qualité de l'air (PM10) afin d'évaluer l'impact des activités anthropiques et le potentiel oxydatif des particules. Des sols et des cultures ont été collectés dans 31 fermes entre 2014 et 2016. Des échantillons d'air ont été prélevés mensuellement sur 3 sites, à proximité des plateformes pétrolières et de la raffinerie. La composition chimique (teneurs en métaux, carbone organique et élémentaire, ions, sucres, polyols, HAPs) a été déterminée dans les PM10. L'évaluation des risques sanitaires a été réalisée via 3 voies d'exposition. Les effets non cancérogènes et cancérogènes ont été quantifiés à l'aide de l'Indice de Risque (HI) et du Risque Total de Cancer (TCR). La bioaccessibilité du Cd par ingestion a été déterminée avec le test BARGE dans les pâtes et fèves de cacao. La formation d'espèces réactives de l'oxygène (ROS) a été quantifiée par spectrophotométrie en utilisant 3 essais acellulaires: DTT, AA et DCFH. Les résultats montrent que dans 72% des sites, les concentrations en Ba, Co, Cu, Cr, Ni, V et Zn dans les sols dépassent les limites de la législation équatorienne. Pour la plupart des cultures, les concentrations en métaux sont inférieures aux limites de détection, sauf pour le Cd dans le cacao et le Pb dans le manioc, qui dérogent aux normes de qualité alimentaire. Les cacaoyers accumulent le Cd dans les feuilles, les cabosses et les fèves. Comme la teneur en Cd du pétrole est inférieure à la limite de détection, les produits agrochimiques et les intrants organiques peuvent être incriminés. Près de 100% de la teneur totale en Cd dans les pâtes et fèves de cacao est bioaccessible par ingestion. Le risque pour la santé après consommation de chocolat oscille entre faible et élevé, selon la quantité ingérée. Dans les PM10, le Ba et le Mo, traceurs spécifiques des activités pétrolières, ont montré des valeurs beaucoup plus élevées que celles enregistrées dans les sites industriels. Les ratios OC/EC étaient plus élevés en Amazonie, suggérant des émissions biogéniques plus importantes. La teneur en HAPs est plus élevée sur la côte, cependant les niveaux de BaP étaient inférieurs aux limites de l'UE. Les résultats du potentiel oxydatif ont montré que les composés émis par l'industrie pétrolière (HAPs, Ba, Ni, Zn), par la combustion de la biomasse (sucres) dans le NAR ainsi que les traceurs industriels dans le NPC (As, Ba, Ni, NH4+) corrèlent avec la génération de ROS. Les principales voies d'exposition aux métaux sont l'ingestion et l'inhalation et, dans une moindre mesure, le contact dermique avec le sol. Les enfants tout comme les adultes sont vulnérables aux effets toxiques de ces composés. Enfin, d'autres facteurs comme la déforestation, l'agriculture et les émissions naturelles (volcans) dans le NAR mais aussi les industries dans le NPC contribuent également aux dégâts environnementaux constatés et aux effets néfastes sur la santé. / Ecuador is the 5th crude oil producer country in South America. Oil extraction and refining generate toxic waste containing metals co-emitted with polycyclic aromatic hydrocarbons (PAHs), naturally present in crude oil or added during production, and known for their carcinogenic and toxic effects in humans. In this context and as a part of the ANR MONOIL program, the first aim of this PhD research was to determine the distribution of metal(loid)s in the environment in the provinces of Orellana and Sucumbíos (oil extraction, North Amazon " NAR ") and the city of Esmeraldas (oil refining, North Pacific Coast, " NPC "). The second aim was to determine if there was a transfer of toxic metals, such as Cd, from soil or air to cacao crops, widely cultivated in Ecuador, and if the consumption of cacao-based products could imply risks for human health. Finally, the third aim was to monitor air quality over 2 years in both areas to assess the impact of anthropogenic activities and the oxidative burden of particulate matter (PM10). Soils and local crops were collected in 31 small-scale farms, between 2014 and 2016. Monthly PM10 samples were collected in 3 sites, in the vicinity of oil platforms close to the refinery. PM10 chemical composition (contents in metals, organic and elementary carbon (OC, EC), ions, sugars, polyols, PAHs) was determined. Human health risk assessment was performed taking into account ingestion, inhalation and dermal contact. Non carcinogenic and carcinogenic effects were quantified using the Hazard Index (HI) and the Total Cancer Risk (TCR). Bioaccessibility of Cd after ingestion was determined by the BARGE in vitro test in cacao beans and liquors. In aerosols, reactive oxygen species (ROS) formation was quantified using 3 acellular assays: DTT (dithiothreitol), AA (ascorbic acid) and DCFH (2',7'-dichlorodihydrofluorescein). Ba, Co, Cu, Cr, Ni, V and Zn concentrations in 72% of the study soils exceeded the limits of the Ecuadorian legislation. For most of the crops, elements were below the limits of detection but, Cd in cacao and Pb in manioc were above the international standards for food quality. Cacao trees accumulate Cd in leaves, pod husks and beans. Because Cd contents in crude oil were below the detection limits, agrochemical products and natural inputs may also be important sources. Almost 100% of the total Cd content in cacao beans and liquor was bioaccessible by ingestion. The health risk after chocolate consumption was low to high, depending on the ingestion rate and the cacao liquor percentage. In PM10, As, Cd, Ni and Pb were below the EU thresholds. However, Ba and Mo, specific tracers of oil activities, used as weighting agents or catalyzers during drilling and refining, showed values much higher than those recorded in other urban-industrialized sites. PM10 composition depended on oil activity. OC/EC ratios were higher in the NAR (oil extraction) than in the NPC (oil refining), suggesting that biogenic emissions were more important in the Amazon area. PAHs contents were higher in the NPC, but levels of benzo-a-pyrene were below the EU limits. Oxidative potential results showed that compounds emitted by oil industry (PAHs, Ba, Ni, Zn) and by biomass burning (sugars) in the NAR as well as industrial tracers in the NPC (As, Ba, Ni, NH4+) were correlated with ROS generation. Regarding residential exposure, the main routes of exposure to metal(loid)s were first ingestion, inhalation and in a small extent soil dermal contact, being both children and adults vulnerable. Finally, the oil Ecuadorian environment is not only contaminated by oil activities. Other factors like deforestation, agriculture and natural emissions (volcanos) in the NAR and industries in the NPC also contribute to environmental damages and may lead to adverse health effects.

<p>One of many applications of geohydraulic modelling is assessing the suitability of a site to host a nuclear waste repository. This modelling task is complicated by scale-dependent heterogeneity and coupled thermo-hydro-mechanical (THM) processes. The objective here was to develop methods for (i) upscaling flow and transport in fractured media from detailed-scale data and (ii) accounting for THM-induced effects on regional-scale transport. An example field data set was used for demonstration.</p><p>A systematic framework was developed where equivalent properties of flow, transport, and stress-effects were estimated with discrete fracture network (DFN) modelling, at some block scale, and then transferred to a regional-scale stochastic continuum (SC) model. The selected block scale allowed a continuum approximation of flow, but not of transport. Instead, block-scale transport was quantified by transit time distributions and modelled with a particle random walk method at the regional scale.</p><p>An enhanced SC-upscaling approach was developed to reproduce the DFN flow results more simply. This required: (i) weighting of the input well-test data by their conductivity-dependent test volumes and (ii) conductivity-dependent correlation structure. Interestingly, the best-fitting correlation structure resembled the density function of DFN transmissivities. </p><p>Channelized transport, over distances exceeding the block scale, was modelled with a transport persistence length. A linear relationship was found between this persistence length and the macroscale dispersion coefficient, with a slope equal to a representative mean block-scale dispersion coefficient.</p><p>A method was also developed to combine well-test data and rock-mechanical data in estimating fracture transmissivities, and its application was demonstrated.</p><p>Finally, an overall sequential THM analysis was introduced allowing the estimation of the significance of waste-related thermo-mechanical (TM) effects on regional transport; here TM effects are calculated separately and their impact on fracture transmissivities were incorporated into the hybrid framework. For the particular case, their effects on regional-scale transport were small.</p>

One of many applications of geohydraulic modelling is assessing the suitability of a site to host a nuclear waste repository. This modelling task is complicated by scale-dependent heterogeneity and coupled thermo-hydro-mechanical (THM) processes. The objective here was to develop methods for (i) upscaling flow and transport in fractured media from detailed-scale data and (ii) accounting for THM-induced effects on regional-scale transport. An example field data set was used for demonstration. A systematic framework was developed where equivalent properties of flow, transport, and stress-effects were estimated with discrete fracture network (DFN) modelling, at some block scale, and then transferred to a regional-scale stochastic continuum (SC) model. The selected block scale allowed a continuum approximation of flow, but not of transport. Instead, block-scale transport was quantified by transit time distributions and modelled with a particle random walk method at the regional scale. An enhanced SC-upscaling approach was developed to reproduce the DFN flow results more simply. This required: (i) weighting of the input well-test data by their conductivity-dependent test volumes and (ii) conductivity-dependent correlation structure. Interestingly, the best-fitting correlation structure resembled the density function of DFN transmissivities. Channelized transport, over distances exceeding the block scale, was modelled with a transport persistence length. A linear relationship was found between this persistence length and the macroscale dispersion coefficient, with a slope equal to a representative mean block-scale dispersion coefficient. A method was also developed to combine well-test data and rock-mechanical data in estimating fracture transmissivities, and its application was demonstrated. Finally, an overall sequential THM analysis was introduced allowing the estimation of the significance of waste-related thermo-mechanical (TM) effects on regional transport; here TM effects are calculated separately and their impact on fracture transmissivities were incorporated into the hybrid framework. For the particular case, their effects on regional-scale transport were small.