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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.
61

Termocronologia por traços de fissão em apatitas na região do Arco de Ponta Grossa, entre os alinhamentos de Guapiara e São Jerônimo-Curiúva

Franco, Ana Olivia Barufi [UNESP] 27 January 2006 (has links) (PDF)
Made available in DSpace on 2014-06-11T19:26:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2006-01-27Bitstream added on 2014-06-13T19:33:38Z : No. of bitstreams: 1 franco_aob_me_rcla.pdf: 2573807 bytes, checksum: 574f9f24f539eb53bda347597a2b1d4d (MD5) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / A evolução do Arco de Ponta Grossa, na região sudeste brasileira, durante o Meso-Cenozóico, apresenta uma estreita relação com os eventos tectono-magmáticos responsáveis pela abertura do Oceano Atlântico- Sul. A utilização do Método de Datação por Traços de Fissão em apatitas, nessa região, permitiu a identificação de cinco eventos térmicos, responsáveis pela estruturação dessa feição, a partir do Cretáceo. São eles: Evento A - Aquecimento em 130 Ma, relacionado ao evento de ruptura do Gondwana Sul-Ocidental e geração do Oceano Atlântico-Sul; Evento B - Resfriamento em 110 Ma, associado à reativação de antigas zonas de cisalhamento e/ou falhas geradas na ocasião do evento de ruptura do Gondwana Sul-Ocidental; Evento C - Aquecimento em 90 Ma, associado à um soerguimento regional, interpretado como alçamento de isógradas, provavelmente como reflexo do soerguimento do Arco de Ponta Grossa e conseqüente sedimentação correlativa (Grupo Bauru ls, no interior continental, e seqüência inferior da Formação Santos, na Bacia homônima), bem como de intrusões alcalinas; Evento D - Resfriamento em 60 Ma, correlacionado à um evento erosivo, que propiciou a formação de uma extensa superfície de erosão, neste caso a Superfície Sulamericana, amplamente registrada tanto na parte continental como na porção submersa adjacente ao Arco de Ponta Grossa (sob a forma de discordância regional na Bacia de Santos); Evento E - Resfriamento em 30/20 Ma, associado à atuação de ciclos erosivos, instalação de bacias tafrogênicas e, localmente, intrusões alcalinas. / The evolution of Ponta Grossa Arch, in southeastern Brazil, during Mesozoic-Cenozoic, seems to be related to the tectono-thermal events related to South Atlantic opening. The use of Apatite fission Track Method, in this region, allowed the recognition of five thermal events, responsible for the formation of this feature, since Cretaceous, which are: Event A - Heating event in 130 Ma, related to the Southeastern Gondwana break-up and the origin of South Atlantic Ocean; Event B - Cooling event in 110 Ma, associated to the shear zones reactivation and/or faults generated during Gondwana break-up; Event C - Heating event in 90 Ma, associated with a regional uplift, interpreted as uplift isotherms, probably as a reflection of Ponta Grossa Arch uplift and correlated sedimentation (Bauru Group ls, in continent and the inferior sequence of Santos Formation, in Santos Basin), and alkaline intrusions; Event D - Cooling event in 60 Ma, correspondent to an erosional event, that formed an extended erosional surface, in this case, Sulamericana Surface, registered both in continental region and in offshore portion (registered as a regional discordance in Santos Basin); Event E - Cooling in 30/20 Ma, related to erosional cycles, tafrogenic basins origin and, locally, alkaline intrusions.
62

Abordagens sintéticas para a funcionalização de novas porfirinas

Barona Castaño, Juan Camilo 30 September 2016 (has links)
Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2016-12-19T09:56:37Z No. of bitstreams: 1 DissJCBC.pdf: 5997390 bytes, checksum: 80e19d348ed8c7141a681d299fed21d7 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2017-01-16T17:35:25Z (GMT) No. of bitstreams: 1 DissJCBC.pdf: 5997390 bytes, checksum: 80e19d348ed8c7141a681d299fed21d7 (MD5) / Approved for entry into archive by Marina Freitas (marinapf@ufscar.br) on 2017-01-16T17:35:35Z (GMT) No. of bitstreams: 1 DissJCBC.pdf: 5997390 bytes, checksum: 80e19d348ed8c7141a681d299fed21d7 (MD5) / Made available in DSpace on 2017-01-16T17:35:49Z (GMT). No. of bitstreams: 1 DissJCBC.pdf: 5997390 bytes, checksum: 80e19d348ed8c7141a681d299fed21d7 (MD5) Previous issue date: 2016-09-30 / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Herein, we optimized some conditions in the synthesis of a β-octasubstitued porphyrin with electron withdrawing groups (1). This system was used to study the bromination of the meso position aiming at subsequent cross-coupling reactions and meso-functionalization of these porphyrin systems (Scheme 3). The main goal was to obtain porphyrin derivatives with modulations in the UV-visible spectra with potential application as photosensitizers for photodynamic therapy treatments (PDT). We found better conditions for the preparation of the porphyrin 1 changing the formaldehyde precursor from trioxane to dimethoxymethane, and reducing the time of second step in the reaction (oxidation of the porphyrinogen). The yield was increased to 13%. After the optimization of 1, different bromination methodologies were tested in order to obtain the meso-bromoporphyrins 2 or 3; but unsuccessfully. In this perspective, we also proposed the synthesis of β-fused porphyrins with imide moieties (Scheme 4), being the functionalized pyrrole 8 the starting material. Porphyrins 9 and 11 might be alternatives for the preparation of new substituted derivatives via cross-coupling reactions, leading to compounds with different photophysical properties. The synthesis of porphyrin 9 was not succeeded by the approaches adopted here, showing only complex mixtures or total degradation of 8. Furthermore, experiments for the formation of dipyrrolmethane 10 were made without any success, precluding the construction of the porphyrin 11. Certain intermediates of interest could be isolated with relative success, and future explorations will be considered. / Neste trabalho foram otimizadas algumas condições de síntese de uma porfirina β-octasubstituída com grupos retiradores de elétrons (1). Em seguida, estudos sobre bromações nas posições meso deste sistema foram realizados objetivando posteriores reações de acoplamento cruzado e meso-funcionalizações destes sistemas porfirínicos (Esquema 1). O objetivo fundamental foi obter derivados porfirínicos com modulações no espectro de UV-visível e posteriores aplicações como fotossensibilizadores em tratamentos por terapia fotodinâmica (PDT). Encontramos melhores condições reacionais para a formação da porfirina 1 mudando o precursor do formaldeído para dimetoximetano e diminuindo o tempo da segunda etapa de reação (oxidação do porfirinogênio). O rendimento obtido neste trabalho foi de 13%. Após a preparação da porfirina 1 iniciamos os testes reacionais visando a meso-bromação e assim, foram testadas várias metodologias, entretanto, em nenhuma das tentativas foi possível obter os compostos desejados 2 ou 3. Ainda neste contexto, propusemos a síntese de porfirinas β-fundidas com unidades imida (Esquema 2), partindo-se do pirrol contendo este grupo funcional. As porfirinas 9 e 11 poderiam ser submetidas à reações de acoplamento similares às anteriores, permitindo a preparação de novos derivados substituídos e, então, a compostos com diferentes propriedades fotofísicas a ser estudadas. A síntese da porfirina 9 não pôde ser realizada pelas abordagens adotadas, mostrando apenas misturas complexas ou degradação total de 8. Ainda, testes de formação do dipirrolometano 10 foram realizados sem sucesso, impossibilitando então, a construção da porfirina 11. Alguns intermediários de interesse puderam ser isolados com relativo sucesso deixando algumas possibilidades de exploração futuras de alguns resultados aqui obtidos.
63

Avalia??o dos efeitos t?xicos in vitro e in vivo do extrato hidroetan?lico dos frutos de Genipa americana L. (Rubiaceae) em camundongos Swiss

Assis, Cinthya Saraiva de 27 October 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-06-23T20:55:01Z No. of bitstreams: 1 CinthyaSaraivaDeAssis_DISSERT.pdf: 1209351 bytes, checksum: 5bb50037084ea9c40b94cff6abdaf523 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-28T17:58:44Z (GMT) No. of bitstreams: 1 CinthyaSaraivaDeAssis_DISSERT.pdf: 1209351 bytes, checksum: 5bb50037084ea9c40b94cff6abdaf523 (MD5) / Made available in DSpace on 2016-06-28T17:58:44Z (GMT). No. of bitstreams: 1 CinthyaSaraivaDeAssis_DISSERT.pdf: 1209351 bytes, checksum: 5bb50037084ea9c40b94cff6abdaf523 (MD5) Previous issue date: 2015-10-27 / O uso terap?utico de plantas medicinais tem contribu?do desde a antiguidade de forma ben?fica para a sa?de. No entanto, muitas esp?cies carecem de evid?ncias cient?ficas que forne?am embasamento para a sua utiliza??o na pr?tica terap?utica. Neste contexto, encontra-se a esp?cie Genipa americana L. (Rubiaceae), conhecida popularmente como jenipapo e utilizada como antissifil?tica, antiulcerosa e anti-hemorr?gica, contra hematomas, como t?nico, afrodis?aco, etc. Visto que, essa esp?cie carece de estudos toxicol?gicos, o objetivo deste trabalho foi avaliar a toxicidade in vivo (toxicidade aguda e subcr?nica) e in vitro (citotoxicidade) do extrato dos frutos da G. americana. O extrato hidroetan?lico dos frutos de G. americana foi preparado por macera??o. Foi realizada uma an?lise fitoqu?mica preliminar para avaliar a presen?a de metab?litos secund?rios no extrato. No estudo da citotoxicidade do extrato (0,1; 1,0; 10; 100 e 1000 ?g/100?L) foram utilizadas linhagens de c?lulas normais (3T3) e tumorais (786-0, HepG2 e B16), analisados pelo ensaio do MTT. Para a avalia??o da toxicidade aguda (dose ?nica de 2000 mg/Kg) e subcr?nica (100, 500 e 1000 mg/Kg por 30 dias) foram utilizados camundongos Swiss de ambos os sexos. Ao final dos experimentos, amostras de sangue e ?rg?os foram coletados para an?lise. Os dados entre os grupos foram comparados pelo test T ou por ANOVA com p?s-teste de Dunnett com n?vel de signific?ncia de 5%. O estudo fitoqu?mico do extrato indicou principalmente a presen?a de irid?ides. Os ensaios de citotoxicidade apresentaram resultados de at? 70% de inibi??o celular frente ? linhagem de B16, na dose de 1000 ?g/100?L, e at? 29% frente ? linhagem 786-0, na dose de 10 ?g/100?L. O extrato n?o promoveu morte nas c?lulas 3T3 e HepG2. Durante as avalia??es in vivo, n?o houve mortes de animais. A an?lise das amostras de sangue revelou que os animais submetidos ? avalia??o da toxicidade aguda apresentaram leves altera??es hep?ticas, e que os animais submetidos ? avalia??o da toxicidade subcr?nica apresentaram altera??es no peso relativo do rim esquerdo e na concentra??o plasm?tica de ur?ia. N?o foram observadas diferen?as entre grupos testes e controles na avalia??o histopatol?gica dos ?rg?os coletados. Apesar das altera??es encontradas nos ensaios de toxicidade in vivo, segundo os crit?rios descritos pelos Guias OECD, sugere-se que o extrato hidroetan?lico dos frutos da G. americana seja classificado como de baixa toxicidade. A citotoxicidade do extrato sugere que omesmo possui potencial contra as linhagens de melanoma (B16) e carcinoma renal (786-0). / The therapeutic use of medicinal plants has contributed since antiquity in a beneficial way for health. However, many species lacks of scientific evidence which provide basis for their use in therapeutic practice. In this context is the Genipa americana L. species (Rubiaceae), popularly known as jenipapo and used to treat syfilis, ulcer and hemorrhagic disturbs. It's also used against bruising, as tonic and as aphrodisiac. Due this species lacks toxicological studies, the aim of this study was to evaluate the toxicity in vivo (acute and sub-chronic toxicity) and in vitro (cytotoxicity) of the hydroethanolic extract from G. americana fruits. The hydroethanolic extract of G. americana fruits was prepared by maceration. A preliminary phytochemical analysis was performed to assess the presence of secondary metabolites in the extract. The cytotoxicity study of the extract (0.1, 1.0, 10, 100 and 1000 mg / 100 ul) were performed against normal cells (3T3) and tumor (786-0, HepG2 and B16), analyzed by the MTT assay. To evaluate the acute (single dose of 2000 mg / Kg) and subchronic (100, 500 and 1000 mg / kg for 30 days) toxicity Swiss mice of both sexes were used. At the end of the experiment, blood samples and organs were collected for analysis. Data between groups were compared by t test or ANOVA with Dunnett's post-test with 5% significance level. The phytochemical study of the extracts mainly indicated the presence of iridoids. Results for cytotoxicity tests showed up to 70% inhibition of B16 cell line at a dose of 1000 mg / 100 ul, and up to 29% inhibition of 786-0 at a dose of 10 ug / 100 ul. The extract did not cause death in 3T3 and HepG2 cells. During the in vivo assays, there were no animal deaths. Analysis of blood samples revealed that the animals submitted to the evaluation of acute toxicity had changes in AST and ALT, and that the animals evaluated for subchronic toxicity showed changes in the relative wet weight of the kidney and plasma urea concentration. No differences were observed between groups on histopathological evaluation of the collected organs. Despite the changes found in the in vivo toxicity tests, using the criteria described by the OECD Guidelines, it is suggested that the hydroethanolic extract of the fruits of the G. americana is classified as low toxicity. The cytotoxicity of the extract suggests that they have potential against melanoma cell lines (B16).
64

Apport d'une résolution verticale plus fine dans le calcul des tendances physiques pour la modélisation du brouillard dans le modèle AROME / The impact of vertical resolution on fog forecasting in the kilometric-scale model AROME

Philip, Alexandre 17 October 2016 (has links)
Le brouillard est un phénomène météorologique dangereux car les fines gouttelettes d'eau en suspension dans l'atmosphère réduisent considérablement la visibilité. Bien que les avancées scientifiques et informatiques permettent d'utiliser des modèles de prévision numérique du temps de plus en plus détaillés, la prévision du brouillard reste encore un challenge dû à la multitude et la complexité des processus mis en jeu lors du cycle de vie du brouillard (dynamique, microphysique, turbulent et radiatif). Dans cette thèse, des simulations sont réalisées sur l'aéroport Paris Charles-de-Gaulle avec le modèle à échelle kilométrique AROME afin d'étudier l'impact de la résolution verticale sur la prévision du brouillard. L'étude détaillée d'un cas de brouillard a permis de mettre en évidence le fort impact de la résolution verticale sur la formation du brouillard. La résolution verticale a un impact sur l'heure de formation, le développement spatial et même sur les processus physiques liés à l'apparition du brouillard. L'impact de la résolution verticale a été évalué statistiquement sur l'hiver 2011-2012 et a permis de confirmer les résultats obtenus lors de l'étude de cas. Il a été mis en évidence qu'une résolution verticale fine permet de simuler davantage de brouillards locaux qu'une résolution verticale lâche. De plus, ces simulations ont souligné que le modèle surestime la hauteur de la base du nuage quelle que soit la résolution verticale. Bien que le nombre de bonnes détections augmente avec une résolution verticale fine, la qualité de la prévision reste inchangée à cause d'un nombre de fausses alarmes plus important ce qui peut être expliqué par l'hétérogénéité spatiale des brouillards simulés. Utiliser une résolution fine sur un grand domaine entraîne un surcoût numérique qui n'est pas envisageable en opérationnel. Dans cette thèse, deux méthodes numériques de représentation de la couche limite de surface permettant d'associer une résolution fine près du sol et un temps de calcul modeste ont été évaluées pour une étude de cas et durant une saison hivernale. La meilleure des méthodes basée sur le schéma Canopy permet de bien représenter le comportement physique du modèle à résolution verticale fine lors de l'apparition de brouillards purement radiatifs. Cependant, la méthode atteint ses limites lorsque l'apparition du brouillard est impactée par des circulations locales car l'advection n'est pas prise en compte par cette méthode. Le diagnostique de brouillard par Canopy permet de corriger le biais sur la fréquence d'occurrence de brouillard mais n'améliore pas significativement la qualité de la prévision. / The fog is a hazardous meteorological phenomenon because of the visibility decrease due to water droplets present in the atmosphere. Despite scientific and numerical improvements allowing the use of very detailed numerical weather prediction models, fog forecasting is still a challenge to address. Indeed, several complex processes are involved during the fog life cycle (dynamic, micro-physic, turbulence and radiation). In this thesis, simulations are performed at the Paris Charles-de-Gaulle airport with the kilo-metric scale model AROME in order to study the impact of the vertical resolution on the fog forecasting. A detailed study case highlights the strong impact of vertical resolution on the fog formation. Vertical resolution impacts both the onset time, the spatial development and also the physical processes involved at the fog onset. The impact of vertical resolution has been evaluated statistically over the winter season 2011-2012 and has confirmed the results obtained with the study case. It has been shown that a finer vertical resolution leads to the simulation of more local fog events than a coarser vertical resolution. Furthermore, these simulations emphasize that the model overestimates the cloud base height whatever the vertical resolution. In spite of the increase of good detections with a finer vertical resolution, the overall forecast quality does not change because of more frequent false alarms. These false alarms can be explained by enhanced spatial heterogeneities of simulated fogs at finer vertical resolution. Using a finer vertical resolution on a large domain increase the numerical cost, which is not affordable for operational forecasting. In this thesis, two numerical methods representing the surface boundary layer and allowing a finer vertical resolution at a low computational cost have been tested for the case study and during the winter season. The best method is based on the surface boundary layer scheme Canopy, which improves the physical behavior of the model during the onset of radiation fogs. However, the limits of the method are reached when the onset is impacted by local circulations, which they are not taken into account with this method. The fog diagnostic by Canopy reduces the frequency bias fog forecast but it does not significantly improve the overall forecast quality because of more frequent false alarms.
65

Exploring the latent structure of IT employees’ intention to resign in South Africa

Le Roux, Mark January 2013 (has links)
One of the major challenges facing South African IT organisations today is the dramatic shortage of IT professionals. Both literature and business sentiment have indicated that employee turnover within the IT sector is on a continually rising trend. The ramifications of these high turnover rates translate into exorbitant direct and indirect costs to organisations. The purpose of this research was to identify the factors pertaining to the underlying structure of the turnover intention of these employees. A deeper understanding of these drivers may possibly enable management to reduce the turnover intention of employees within their organisations. A quantitative, multi-disciplinary research approach, focussing on the antecedents of turnover intention and the three systemic levels of organisational behaviour (micro, meso and macro) was used to operationalise the main research construct of this study. Data was collected by means of an anonymous self-administered web-based survey. A sample of 188 completed questionnaires was collected using a snowball sampling technique from the population of employees in the IT industry in South Africa. A statistical data reduction method, exploratory factor analysis, was conducted on the dataset to determine the underlying nature of the construct, IT employees’ perceived intention to resign from employment. After an appropriate number of factor analytic rounds, a robust 4-factor model of the data set was established. The results indicated that the factor, Personal Enrichment from Management Support, possibly plays the most significant role in understanding, monitoring, and managing IT employees’ perceived intention to resign from employment. The study provided support that monetary factors had the most significant influence in an employee’s decision to join an organisation; however, nonmonetary benefits, such as job satisfaction and skills development, were found to be more effective in retaining employees. The practical implications uncovered from this study will enable management to gain further insight into understanding the underlying factors and drivers of turnover intention and thereby minimise its impact on the organisation. / Dissertation (MBA)--University of Pretoria, 2013. / lmgibs2014 / Gordon Institute of Business Science (GIBS) / MBA / Unrestricted
66

Characterization and Modeling of the Martensite Transformation in Advanced High-Strength Steels

Cluff, Stephen Roy 09 December 2019 (has links)
Multiple studies on the microstructures of advanced high-strength steels are presented here that seek to add to the already substantial body of knowledge on martensite in steel. These studies seek to gain additional insight into the role that the martensite transformation has on the observed mechanical properties of modern steels. Crystallographic Reconstruction of Parent Austenite Twin Boundaries in a Lath Martensitic Steel The study of post-transformation microstructures and their properties can be greatly enhanced by studying their dependence on the grain boundary content of parent microstructures. Recent work has extended the crystallographic reconstruction of parent austenite in steels to include the reconstruction of special boundaries, such as annealing twins. These reconstructions present unique challenges, as twinned austenite grains share a subset of possible daughter variant orientations. This gives rise to regions of ambiguity in a reconstruction. A technique for the reconstruction of twin boundaries is presented here that is capable of reconstructing 60 degree twins, even in the case where twin regions are comprised entirely of variants that are common between the twin and the parent. This technique is demonstrated in the reconstruction of lath martensitic steels. The reconstruction method utilizes a delayed decision-making approach, where a chosen orientation relationship is used to define all possible groupings of daughter grains into possible parents before divisive decisions are made. These overlapping, inclusive groupings (called clusters) are compared to each other individually using their calculated parent austenite orientations and the topographical nature of the overlapping region. These comparisons are used to uncover possible locations of twin boundaries present in the parent austenite. This technique can be applied to future studies on the dependence of post-transformation microstructures on the special grain boundary content of parent microstructures. Coupling Kinetic Monte Carlo and Implicit Finite Element Methods for Predicting the Strain Path Sensitivity of the Mechanically Induced Martensite Transformation The kinetic Monte Carlo method is coupled with a finite-element solver to simulate the nucleation of martensite inside the retained austenite regions of a TRIP (transformation induced plasticity) assisted steel. Nucleation kinetics are expressed as a function of load path and kinematic coupling between retained austenite regions. The model for martensite nucleation incorporates known elements of the kinetics and crystallography of martensite. The dependence of martensite transformation on load path is simulated and compared to published experimental results. The differences in transformation rates of retained austenite are shown to depend on load path through the Magee effect. The effects of average nearest neighbor distance between austenite grains is shown to affect the rate at which martensite nucleates differently depending on load path. Ductility and Strain Localization of Advanced High-Strength Steel in the Presence of a Sheared Edge The localization of strain in the microstructures of DP 980 and TBF 980 is quantified and compared. Of particular interest is the difference in final elongation observed for both materials in the presence of a sheared edge. Scanning electron micrographs of etched microstructures near the sheared edge are gathered for both materials at varying amounts of macroscopic strain. These micrographs are used to generate strain maps using digital image correlation. A two point statistical measure for strain localization is developed that utilizes strain map data to quantify the degree to which strain localizes around the hard phase of both materials. The DP steel exhibits higher strain localization around the martensite phase. Reasons for differences in strain localization and shear banding between the two materials are suggested, and the role played by the mechanically induced martensite transformation is speculated.
67

A study of water vapor variability associated with deep convection using a dense GNSS receiver network and a non-hydrostatic numerical model / 稠密GNSS可降水量観測ネットワークと非静力学モデルを用いた深い対流に伴う水蒸気変動に関する研究

Oigawa, Masanori 23 March 2016 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19505号 / 理博第4165号 / 新制||理||1598(附属図書館) / 32541 / 京都大学大学院理学研究科地球惑星科学専攻 / (主査)教授 津田 敏隆, 教授 石川 裕彦, 教授 余田 成男 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
68

Pelagic larval duration and growth rate of the endemic reef fish, halichoeres socialis (Labridae): Mesoamerican barrier reef, Central America

Sun, Zhixian 19 March 2024 (has links)
Halichoeres socialis Randall & Lobel, 2003, is the only wrasse species (Teleostei: Labridae) with a restricted distribution within the Caribbean Meso-American Barrier Reef (MABR), Central America. This study examined the early life history of H. socialis to gain insight into its natural history and to assess if any pattern in otolith microstructure could be linked to its endemism. The sagittal otoliths from 67 individuals (ranging 9.8–43.4mm SL) were analyzed to determine the daily age and increment profile. Results indicate that (1) H. socialis displays a typical “settlement mark”; (2) the pelagic larval duration (PLD) ranged from 22 to 32 (mean=27, n=59) days, which was similar to its congeners; and (3) the juvenile growth rate is 0.7mm/d, which was faster than most congeners. The endemism of H. socialis is not explained by its PLD. Alternatively, it is possible that larval behaviors (vertical migration and/or schooling) play a key factor in how H. socialis larvae are retained within the MABR region. / 2026-03-19T00:00:00Z
69

Caractérisation des vents de vallée en conditions stables à partir de la campagne de mesures KASCADE et de simulations WRF à méso-échelle / Characterization of down-valley winds in stable stratification from the kascade field campaign and WRF mesoscale simulations

Duine, Gert-Jan 12 October 2015 (has links)
Cette thèse est dédiée à la caractérisation des vents descendants de vallée en terrain complexe d'orographie modérée à moyenne latitude, dans le contexte de la réglementation des rejets atmosphériques de Cadarache. Cadarache est un des centres de recherche du "Commissariat à l'énergie atomique et aux énergies alternatives" (CEA), installé dans une petite vallée (CV) confluente à la vallée de la Durance (DV). Ces deux vallées se distinguent par leur taille, et sont le siège d'écoulements aux caractéristiques différentes en stratification stable. Un forçage synoptique faible associé à un ciel dégagé sont dans la région des conditions fréquentes qui favorisent la stabilité atmosphérique et consécutivement la mauvaise dispersion des polluants, faisant de cette situation un sujet d'intérêt majeur. La campagne de mesure KASCADE (KAtabatic winds and Stability over CAdarache for Dispersion of Effluents) constitue le volet expérimental de l'étude. Réalisée pendant l'hiver 2013 elle a couvert 3 mois d'observation continue et complétée de 23 périodes d'observation intensive (POI). L'analyse montre que les écoulements descendant les vallées de Cadarache (CDV) et de la Durance (DDV) dominent pendant toute la période d'étude. La stabilité s'installant dès le coucher du soleil, le courant CDV s'épaissit progressivement. Le profil de vent en forme de jet présente son maximum à environ 30 m où il atteint 2 à 3 m s-1. Il se maintient toute la nuit et disparaît avec l'inversion de stabilité. Comme la station météorologique du centre manque de capteur de vent dans la CV même, une méthode a été développée pour diagnostiquer le CDV en exploitant l'instrumentation actuelle. Ainsi, si la prévision de ce vent n'est pas à la portée du modèle méso-échelle WRF avec une résolution kilométrique, cette méthode le permet en combinant une descente d'échelle dynamique et statistique. Le vent DDV est identifié comme un vent qui suit l'axe de la vallée, fortement corrélé à la stabilité à l'échelle régionale car il n'apparaît que la nuit lorsque le forçage synoptique est faible. Ce vent n'arrive à Cadarache que 6 à 9 heures après le coucher du soleil avec une grande variabilité. D'un autre côté, il est à son maximum au lever du soleil avant que les processus convectifs ne démarrent, et présente un jet autour de 200 m avec des vitesses de 4 à 8 m s-1 et dont la hauteur est corrélée à la profondeur de la vallée. Dans les simulations avec WRF, malgré des défauts, la DV étant bien résolue avec une maille de 1 km, l'occurrence de ce vent est assez bien simulée. Par ailleurs l'examen de ses caractéristiques spatiales montre qu'il s'agit soit d'un écoulement de drainage, soit d'un écoulement canalisé forcé. Bien qu'on ne dispose pas de données suffisantes pour élucider le mécanisme dominant de déclenchement du vent DDV, les deux précédemment identifiés sont de bons candidats. / Stable stratification can be one of the most penalizing condition concerning pollutants in the atmospheric boundary layer. Over complex terrain under these conditions, the relief may modify the flow. Therefore the knowledge of down-valley wind characteristics influencing the wind field at Cadarache and its close surroundings is crucial for safety regulation in the context of sanitary impact of the site. Cadarache is a CEA research centre and located in the Prealps of southeast France. It is embedded in a small valley, the Cadarache Valley (CV), which is one of the tributaries of the larger Durance Valley (DV). The two valleys are distinct in size and therefore react differently to stable conditions, and are investigated by means of observations (field experiment KASCADE : KAtabatic winds and Stability over CADarache for Dispersion of Effluents) and simulations (the Weather Research and Forecasting (WRF) model). To investigate the valley wind behaviour, the KASCADE campaign has been designed and conducted in the winter of 2013, covering a 3-month period and 23 intensive observation periods (IOP). It resulted in a well-documented campaign, from which the analysis shows that the Cadarache and Durance down-valley (CDV and DDV respectively) winds are both dominant flows during the period of investigation. The CDV wind is a thermally driven flow, with regular wind speeds up to 2 - 3 m s-1 up to 50 m agl. It persists throughout the night and disappears in the early morning with the stability. The current observational network of Cadarache lacks means of measurement for inside CDV wind. This work shows that it can be nowcasted from available meteorological tower observations. Due to the CV small scale, currently a wind forecast on kilometer resolution is out of reach, but the methodology developed here can be used to forecast the wind through a combination of dynamical and statistical downscaling. The DDV wind has been recognized as down-valley oriented, and strongly related to stability at a regional scale, as it exists only after sunset when synoptic forcing is very weak. DDV wind arrival at Cadarache is mostly observed 6 to 9 hours after sunset, but however dominantly present around sunrise, when convectively driven processes are not yet established. Jets are observed mostly at around 200 m agl with wind speeds between 4 and 8 m s-1. Despite some (general) deficiencies of the WRF model, the DDV wind is simulated close to reality thanks to the 1-km resolution allowing a correct representation of the Durance valley orography. The ensemble of 23 simulated IOPs allowed further to characterize the flow in a spatial sense and to recognize drainage and flow channelling as most important candidates for the flow mechanism.
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Análise transdisciplinar, evolutiva e sustentável de uma filière de biocombustível : a macaúba em Montes Claros/M.G.

Lima, Marcelo Mencarini January 2011 (has links)
Há pouca informação sobre o agronegócio sustentável para biocombustíveis elaborados a partir de oleaginosas florestais perenes, num contexto de sóciobiodiversidade. Na presente pesquisa, foi proposto e aplicado um framework para analisar a emergência, evolução e consolidação de uma filière do biodiesel a partir da macaúba, uma oleaginosa florestal perene, orientada pelo desenvolvimento sustentável. Para isso, utilizou-se a combinação de três abordagens e instrumentos, resumidos a seguir: O primeiro é o metaframework transdisciplinar de Munasinghe (2002), o Sustainomics. O segundo, constituído pela análise de filière, uma abordagem francesa, e suas diretrizes mesoanalíticas: tecnologias, estratégia e relações (MONTIGAUD, 1991). O terceiro, no âmbito da Economia Evolutiva, utilizou-se o framework Micro-Meso-Macro (DOPFER, FOSTER e POTTS, 2004). Essas abordagens e alguns de seus instrumentos foram ajustados entre si, por meio de suas dimensões e elementos integrativos, para proposição de um novo framework na presente pesquisa, intitulado “Cadeia Oleaginosa Florestal Perene Micro- Meso-Macro Transdisciplinar-Sustainomics”, concebido tanto para a identificação como a recomendação de prioridades presentes e futuras para a cadeia estudada. A presente pesquisa é exploratória e qualitativa, na qual foram coletados dados primários e secundários. Na coleta de dados primários, foram feitas entrevistas, registradas em vídeo. Dos 7 elos identificados na filière da macaúba, o estudo de caso abordou os sistemas de produção, adotados e prospectados, no Elo Agrícola e na Agroindústria, no período entre 2004 a 2009, no locus geográfico do município de Montes Claros/MG. Os resultados foram interpretados com base nos instrumentos Matriz de Impacto da Ação, Análise diagnóstica sistêmica da filière e em duas técnicas da Economia Evolutiva: a Trajetória Micro Como um Domínio Analítico e a Análise da Trajetória Meso Genérica. Identificou-se em primeiro lugar, que das 6 empresas que atuam diretamente na filière emergente, no Brasil, nenhuma explora exclusivamente biodiesel de macaúba. Em segundo, existe a possibilidade de um jogo do tipo ganha-ganha no caso analisado, possibilitando simultaneamente “a melhoria da vida das pessoas pobres e o combate ao problema das mudanças climáticas” (MUNASINGHE, 2002). Na analise dos resultados são apontados, a recomendação de substituições progressivas: 1) Do diesel fóssil por biocombustíveis, que tenham ciclo de vida, de fato, renovável; 2) Das matérias-primas de ciclo anual, com baixos rendimentos em biocombustíveis, provenientes de monocultivos, por policultivos de culturas perenes, da biodiversidade dos biomas, com foco na macaúba para o Cerrado; 3) Da monocultura da soja pelas matérias-primas para biocombustíveis oriundas dos recursos florestais naturais não madeiráveis, organizada em sistema de produção agroflorestas sucessionais, com inovação pelo uso nas áreas de Reservas Legais, sustentáveis na forma de campos de produção. 4) Da entropia do desmatamento, pela sintropia; 5) Do biodiesel pelo uso direto – SVO: desatrelar o processo tecnológico agroindustrial equivocado de transesterificação do óleo vegetal para retirada da glicerina do óleo; 6) Dos motores de ciclo diesel não adiabáticos, produzidos e utilizados no Brasil, por novas tecnologias disponíveis: operar com temperaturas mais altas para queimar, como biocombustível, também a glicerina, evitar a desnecessária geração de resíduos. Por fim, o framework de análise para culturas perenes oleaginosas sustentáveis (Cadeia Oleaginosa Florestal Perene Micro-Meso-Macro Transdisciplinar-Sustainomics) utilizado neste estudo de caso, pode ser aplicado para outras culturas similares, com o objetivo de evitar catástrofes bruscas, sem demora, eliminando atividades que ameacem superar o limiar de segurança e capacidade de carga dos ecossistemas da Terra, por meio do aumento de sua resiliência. / There is little information about the sustainable agribusiness for biofuels made from perennial oil forest of sociobiodiversity context. This research aimed to propose a framework and analyze the emergence, evolution and consolidation of a biodiesel filière from Macaúba, guided by sustainable development. For this, it proposes a new model by combinning tree approaches and instruments from the models sumarized as follow: The first tool model is the practical method of Munasinghe (2002): a transdisciplinary metaframework, the Sustainomics, that has evaluative techniques of unsustainable activities. The second is the Filière Method, composed by the following mesoanalitics guidelines: technology, strategy and relationships (MONTIGAUD, 1991). The third envolves levels of Evolutionary Economics, derivatives from the Framework Micro-Meso-Macro (DOPFER FOSTER and POTTS, 2004). These approaches and some instruments used from the models, fit together the dimensions and elements of integration, to propose the mentioned new model entitled as a neologism “Cadeia Oleaginosa Florestal Perene Micro-Meso-Macro Transdisciplinar-Sustainomics”, designed to identify and to recommend urgent priorities in the present and in the future, to the studied chain. This research is exploratory, qualitative, within collected primary and secondary data. Primary data was interviews with video recorded. From the seven rings of chain (Macaúba filière) that were identified, the study case addresses the production systems, some adopted and some prospected, in Agricultural and Agroindustry rings, between the period from 2004 to 2009, the geographical locus of the municipality of Montes Claros/MG. The results were analyzed based on the instruments, as follow: Action Impact Matrix, Diagnostic analysis of systemic filière, and two Evolutionary Economics techniques: Trajectory Micro as an Analytical Domain and Analysis of the Meso Generic Trajectory. It was identified, first, that: the six companies operating directly in emerging filière, none operates exclusively Macaw Palm’s biodiesel. The Second consideration refers that it is possible a win-win game, for the analysed case, making possible coexistence: “improving the lives of poor people and addressing the issue of climate change” (MUNASINGHE, 2002). The results pointed the recomendations of progressive replacement of: 1) The fossil diesel through biofuels, which have life cycle, in fact, renewed; 2) The raw materials of the annual cycle, with low yields of biofuels from monocultures, through polycultures of perennial crops, from biodiversity biomes, focusing on Macaw Palm, for Savannah. 3) the monoculture of soybeans for biofuels, through raw-material derived from Non-Timber Natural Forest resources, organized in successional agroforestry system of production, with innovation for use inthe areas of Legal Reserves, as sustainable production fields. 4) The entropy of deforestation, through the Syntropy; 5) From biodiesel through the direct use - SVO: unleash the technological process of wrong agroindustrial transesterification of vegetable oil to remove the glycerin from the oil; 6) From diesel cicle engines non-adiabatic, produced and used in Brazil through new available technologies: to operate at higher temperatures to burn, as biofuel, as well as glycerin, to avoid unnecessary waste generation. Summing up, the analysis model for perennial crops, oilseeds sustainable (Cadeia Oleaginosa Florestal Perene Micro-Meso-Macro Transdisciplinar-Sustainomics), used in this case study can be applied to other similar cultures, in order to prevent sudden disasters, without delay, eliminating activities that threaten to exceed the safety threshold and carrying capacity of Earth's ecosystems, by increasing its resilience.

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