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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.
891

Recherche d'optimisation énergétique d'un réacteur plasma froid de traitement d'effluents gazeux chargés en composés organiques volatils à pression atmosphérique. / Energetic optimization of cold plasma process for VOC charged industrial gaseous effluent treatment

Mericam bourdet, Nicolas 19 March 2012 (has links)
Ce travail s’inscrit dans le processus de développement d’un dispositif de traitement de composés organiques volatils (COV) par plasma non-thermique. L’application industrielle des dispositifs de dépollution par plasma froid se heurte à deux limitations majeures que sont une consommation énergétique importante et la formation de sous-produits. Deux axes d’amélioration de l’efficacité énergétique du procédé à décharges sur barrière diélectrique sont explorés dans ce travail de thèse : le mode de dépôt d’énergie dans la décharge et le couplage du réacteur plasma avec un dispositif catalytique. Concernant le premier axe, l’étude a montré que dans le cas des réacteurs DBD étudiés, le paramètre gouvernant la réactivité chimique du plasma à pression atmosphérique était la densité d’énergie, qu’il s’agisse de production d’ozone ou d’élimination d’un COV de la phase gazeuse. L’étude chimique des sous-produits de dégradation par décharge a été conduite pour trois molécules cibles : l’éthanol, l’acétone et la méthyléthylcétone. Dans le cas de l’éthanol, un schéma cinétique 0D est proposé, montrant l’importance de la dissociation dans les mécanismes de dégradation du COV. Pour le second axe exploré, le réacteur plasma a été couplé à un catalyseur. Deux formulations de catalyseurs ont été utilisées, avec et sans métaux précieux. Dans les deux cas, l’activation du catalyseur à basse température par couplage avec le réacteur plasma est démontrée. La dernière partie de l’étude présente les résultats obtenus sur un réacteur plasma à échelle pilote visant à estimer l’impact de l’augmentation des capacités de traitement d’un réacteur DBD sur l’efficacité énergétique du procédé. / This work deals with the development of a VOC removal method by non-thermal plasma which has several advantages including flexibility, compactness and limited investment costs. Further development of this technology needs to overcome major drawbacks such as high energy consumption for high flow rate treatment and the presence of by-products. The first part of the study focuses on the method of discharge energy deposition and the search for optimization of the process energy efficiency. Development of experimental and measurement tools, in particular for the determination of the electrical power injected into the discharge were carefully carried out. The effect of voltage waveform, signal frequency and electrode shape were investigated. The results show that no energy efficiency improvement could be brought by variation of these parameters and that only energy density is important in the gas treatment process. The second part of the study was devoted to the study of conversion of three pollutants (acetone, ethanol and methylethylketone). Formation of by-products was analyzed and a kinetic scheme is proposed for ethanol conversion. To decrease the level of by-products at the reactor outlet, the association between cold plasma and catalysis was investigated. Catalysis was found to allow an improvement in the oxidation of the pollutants and of the discharge by-products. The last part of this work focused on results obtained with a large flow rate plasma reactor to confirm extension of laboratory scale results to larger equipment. Results confirmed that the extension of low flow rate experimental results is possible.
892

Skills training and development : Russia in comparative perspective

Anikin, Vasiliy January 2018 (has links)
The acquisition and maintenance of human capital are considered key drivers of productivity and economic growth. However, recent literature shows that in the case of Russia, this relationship is not obvious, which raises a question concerning the nature of human capital accumulation, despite the significant expansion of tertiary education in this country. The existing literature, much of it relying on a theory of market imperfections, tends to explain low incidences of training by the lack of employer incentives to invest in the human capital of their employees. This dissertation adds to this view confirming the negative role of ‘bad’ jobs and social origins in obstructing employees from skills development in BRIC-like countries. Skills training in Russia is constrained by stratifying occupational forces comprising jobs with low requirements to skills development, which conserves the working population in generic labour. This reveals the phenomenon of skills polarisation ‘at the bottom’ in a late-industrial country, thus, contributing to the growing critique of the knowledge society theory. For those few workers who occupy ‘good’ jobs, skills training is strongly linked to personal-specific traits, such as qualifications and computer and language skills; and this is common in both Russia and India. However, in contrast to Russia, India is still forming their knowledge society. This is confirmed by the statistically significant impact of socio-demographic origins (e.g. age, household size, marital status, and religion) on the incidence of training, which reveals a crucial role of ascription in human capital acquisition in contemporary India. The present thesis contributes to the growing literature on structural prerequisites for successful advancement and the contradictory development of the BRIC countries.
893

BDNF/TrkB em câncer colorretal : interações funcionais com GRPR e EGFR

Farias, Caroline Brunetto de January 2012 (has links)
BDNF/TrkB são descritos em diversas neoplasias onde iniciam sinais mitogênicos, facilitam o crescimento tumoral, previnem apoptose e regulam angiogênese e metástase. Outros fatores de crescimento também são importantes para tumorigênese, como GRP/GRPR e EGF/EGFR. O objetivo geral deste trabalho foi investigar o papel de BDNF/TrkB em câncer colorretal avaliando possíveis interações com GRPR e EGFR. Verificamos que BDNF e seu receptor, TrkB, estão presentes em amostras de pacientes com câncer colorretal esporádico, e os níveis de BDNF encontram-se mais elevados no tecido neoplásico que no tecido adjacente ao tumor. O tratamento com RC- 3095, um antagonista de GRPR, na linhagem celular de câncer colorretal humana, HT-29, causa diminuição nos níveis de NGF secretados pelas células e aumento de BDNF em relação ao controle não tratado. RC-3095 inibe a proliferação e viabilidade celular das linhagens HT-29 (EGFR positiva) e SW-620 (EGFR negativa), embora apenas em HT-29 ocorra um aumento significativo na expressão de mRNA de BDNF. Por isso, um anticorpo monoclonal anti-EGFR, cetuximabe, foi combinado a RC-3095, nas células HT-29, sendo capaz de prevenir tal aumento, sugerindo que este efeito seja mediado por EGFR. Os tratamentos com um inibidor de Trks, K252a (1000 nM) ou com cetuximabe (10 nM) também inibem a proliferação celular. Entretanto, a combinação de BDNF a cetuximabe previne este efeito, enquanto que a combinação de doses não efetivas de K252a (10 nM) à cetuximabe (1 nM) inibe a proliferação celular de HT- 29. Além disso, cetuximabe também causa aumento na expressão de mRNA de TrkB e BDNF, após 600 minutos de tratamento. Nossos resultados sugerem que a inibição da proliferação celular in vitro ou do crescimento tumoral in vivo devem acontecer através do bloqueio combinado entre GRPR e TrkB em células de câncer colorretal EGFR positivas, e que BDNF também esteja envolvido em mecanismos de resistência a fármacos. Por isso, o bloqueio de BDNF / TrkB pode emergir como potencial alvo antitumoral. / BDNF / TrkB are described in various cancers where they participate in tumor growth, apoptosis, angiogenesis and metastasis. Furthermore, other growth factors are also important to tumorigenesis as GRP/GRPR and EGF/EGFR. Therefore, the aim of this study was to investigate the role of BDNF/TrkB in colorectal cancer evaluating the interactions with GRPR and EGFR. We found that BDNF and its receptor, TrkB, are present in samples from patients diagnosed with sporadic colorectal cancer, and BDNF levels were higher in tumor tissue compared to adjacent tumor tissue. Treatment with RC-3095, GRPR antagonist, in human colorectal cancer cell line, HT-29 caused a decrease in NGF levels secreted by cells, and generated increase of BDNF when compared to untreated control. RC-3095 inhibited the proliferation and cell viability in HT-29 (EGFR positive) and SW-620 (EGFR negative), but only HT-29 cells showed a significant increase in BDNF mRNA expression. Therefore, a monoclonal anti-EGFR antibody, cetuximab was combined with RC-3095 in HT-29 cells, and was able to prevent such an increase, suggesting that this effect is mediated by EGFR. The treatment with a Trk inhibitor, K252a (1000 nM) or cetuximab (10 nM), inhibited cell proliferation. However, the combination of BDNF with cetuximab prevented this effect, whereas the combination of ineffective doses of K252a (10 nM) with cetuximab (1 nM) still inhibited cell proliferation of HT-29. Furthermore, cetuximab also caused an increase in BDNF and TrkB mRNA expression, 600 minutes after treatment. In summary, our results suggest that inhibition of cell proliferation in vitro or tumor growth in vivo must occur between the combination of GRPR and TrkB in EGFR positive colorectal cancer cells, and that BDNF is also involved in drug resistance mechanisms. Therefore, blockage of BDNF / TrkB may emerge as potential antitumor target.
894

The impact of the 'war on terror' on Birmingham's Pakistani/Kashmiri Muslims' perceptions of the state, the police and Islamic identities

Ahmed, Shamila Kouser January 2012 (has links)
This thesis explores British Muslims’ counter discourse to the ‘war on terror’ through revealing the impact of the dominant ‘war on terror’ discourse created by the state. The research explores the counter discourse through investigating the impact of the ‘war on terror’ on Birmingham’s Pakistani / Kashmiri Muslims’ perceptions of the state, the police and Islamic identities before the ‘war on terror’ and since the ‘war on terror’. The theoretical perspectives of cosmopolitanism and citizenship are used as a foundation from which the ‘war on terror’ and the role of the state and the police in the ‘war on terror’ can be deconstructed, critiqued and reconstructed according to Muslim citizens’ perceptions. In particular attention is paid to the challenges and difficulties the 32 respondents interviewed for the research have faced since the ‘war on terror’. Many themes emerged through this framework and the core themes were injustice, legitimacy and human rights. The impact of the ‘war on terror’ showed the battle for Islamic identity construction versus resistance and the negative impact of regulatory discourses on perceptions of commonality, unity and shared identities.
895

Urban Transformation Of Ottoman Port Cities In The Nineteenth Century: Change From Ottoman Beirut To French Mandatory Beirut

Kihtir Ozturk, Pelin 01 September 2006 (has links) (PDF)
This thesis attempts to give the increasing importance of Ottoman port cities in the urban hierarchy during the nineteenth century and analyzes the urban transformation of these cities under the forces of changing administrative and socio-economic structure of the empire. The impact of European economic penetration and Ottoman Tanzimat Reforms were indicated as major causes for this changing structure. Beirut, being one of the major port cities of the Ottoman Empire is studied as a case study. The changing administrative and socio-economic structure of the Empire created an urban transformation which changed the city to a cosmopolitan trade capital from a small fortified port city.
896

Exploring Crime In A Spatial And Temporal Context: Suitable Response Strategies For Urban Planning And Policing By The Case Of Etlik Police Station Zone

Erdogan, Aygun 01 September 2007 (has links) (PDF)
This study explores incidents in a spatial and temporal context to achieve suitable strategies for urban planning and policing in crime prevention/reduction. For this purpose, space and time related incidents are analyzed through new crime ecology theories within the designed loose-coupled GIS-based system at mezo-micro ecological levels in a case area within Ankara Metropolis, in 2000. Its main argument is that incidents display differences in the spatial and/or temporal distribution among planned, squatter, and in-transition settlements. In exploring distribution of incidents at global and local scales, it also searches the validity and critical adaptability of the new theories developed/practiced in North American and European countries. In line with new theories, incidents at global scale displayed clustering in space and time. Generally, incidents in aggregate, concentrated mostly in planned / less in in-transition / least in squatter areas / and particularly during spring-summer months. However, incidents against people and against property predominated respectively in squatter and planned areas, and between 18:00-00:00, and 00:00-08:00. As for local scale, incidents in aggregate, displayed spatial interaction (clustering), but no space-time interaction. Spatial distribution in time suggested that incidents persistently occur mainly in planned areas. v Incidents against property displayed highest level of spatial, and also temporal clustering at global scale / and particularly spatial clustering (particularly for commercial burglaries/thefts) and space-time clustering (for residential burglaries) at local scale. Complementarily, relatively homogenous global scale spatial distribution of incidents against people is accompanied by their non local scale spatial clustering or space-time clustering, whereby space-time dispersion was observed for simple batteries.
897

Spatial Analysis Of Mega-event Hosting: Olympic Host And Olympic Bid Cities

Erten, Sertac 01 January 2008 (has links) (PDF)
The aim of this dissertation is to provide a new perspective to the analysis of megaevent / host city relationship. The significance of the research subject depends on the interest in hosting mega-events such as the Olympic Games and the World Fairs, which generate a competition among cities. Turkish cities are recently being involved in this competition. In addition to that, mega-events have large-scale and long-term impacts on the built environment, which has not been thoroughly discussed in urban studies. The methodology which is based on a qualitative analysis comprises three steps: a historical analysis made on the Olympic host cities, and two case studies. The first case is Athens as the 2004 Olympic city, the second case is Istanbul as an Olympic bid city since 1990. This study recognizes but qualifies the concept of megaevent hosting. It is shown that mega-event hosting is a capacity-building process, whilst it has a potential to generate overdose investments problem in the built environment. The most significant conclusion of the study is that the ability of coping with this problem is correlated with the ability of absorbing the investments made.
898

Urban Coastal Settlements: Implementation Of A Coastal Area Assessment Model In Iskenderun Case

Cakir, Bilge 01 August 2010 (has links) (PDF)
Coastal urban settlements require a special planning approach since they bring the concepts of &ldquo / urban&rdquo / and &ldquo / coastal&rdquo / together. In relation to the specific contents of these concepts, there are also different models of management plans. &ldquo / Urban Disaster Risk Management&rdquo / and &ldquo / Integrated Coastal Zone Management&rdquo / are two of them. Urban Disaster Risk Management model deals with the planning and management problems of urban settlements in the case of disaster risk conditions. Likewise, Integrated Coastal Zone Management model focuses on the whole coastal area and deals with the sustainable use and protection of all types of coastal resources. However, in case of urban coastal settlements, these models of management plans can be valid together, can overlap, and they can even conflict with each other. In this thesis study, these two models of management plan and their coexistence are considered. A Coastal Area Assessment Model is set up and applied for Iskenderun case. This model provides a detailed spatial analysis opportunity in planning and management of coastal urban settlement. Therefore the model offers a significant input for the planning process through determining urban and coastal risks at the same time. Coastal Area Assessment Model is a tool which takes both Urban Disaster Risk Management and Integrated Coastal Zone Management models&rsquo / concerns into account and evaluates the coastal settlement in terms of urban risk sectors and coastal management issues. This study also introduces an approach on classification of the coastal areas and coastal urban settlements while setting up the Coastal Area Assessment Model. Coastal Area Assessment Model becomes an advantageous tool since it has significant contributions to the planning process by making a simple risk analysis and guiding the proper utilization and protection of the population, built environment, and resources of the coastal areas. Risk sectors, coastal management issues, critical and prior intervention areas of a coastal urban settlement are easily determined, and preparation of development plans of a coastal settlement is guided by the implementation of Coastal Area Assessment Model. In addition to these, general principles on planning and management of coastal settlements are determined by the implementation of the model for the implementation conditions of Urban Disaster Risk Management model, Integrated Coastal Zone Management model, and the Coastal Area Assessment Model in Turkey are also discussed and presented.
899

Les récepteurs 5-HT4b adoptent différentes conformations ligand-spécifique ayant des propriétés de signalisation et de régulation distinctes

Younes, Stephane Y. 04 1900 (has links)
Les antidépresseurs actuels sont très similaires au niveau de leur mécanisme d’action et sont plus ou moins efficaces. Un des problèmes majeurs est leur long temps de latence à fournir une action thérapeutique dû aux adaptations des sites pré et post synaptiques. Dans un modèle animal, nous avons récemment découvert que l’agoniste RS67333 des récepteurs 5-HT4 était en mesure de produire en trois jours les mêmes effets antidépresseurs qui normalement prennent de deux à trois semaines à apparaître avec les antidépresseurs actuellement disponibles. De plus, nous avons constaté que les effets antidépresseurs de cet agoniste possédaient une résistance à la tolérance. Il y a d’autres agonistes du même récepteur, tel que le prucalopride qui ne produit pas d’effets antidépresseurs comme RS67333. Étant donné que l’efficacité du Prucalopride à stimuler les 5-HT4Rs est similaire sinon plus grande que celle de RS67333, nous avons énoncé l’hypothèse que le récepteur 5-HT4 pourrait adopter différentes conformations actives suite à son activation par différents agonistes. Nous avons ainsi décidé d’explorer les principales réponses fonctionnelles des récepteurs 5-HT4B en observant leurs propriétés de régulation et de signalisation. Nous avons montré que l’isoforme B du récepteur 5-HT4, étant hautement exprimé dans le système limbique, détient une signalisation et une régulation différentes dépendant du ligand activateur. Nos résultats indiquent que chacun des agonistes testés (5-HT, RS67333, ML10302, Zacopride, Prucalopride) modulent distinctivement la production d’AMPc et l’internalisation du récepteur. Les résultats nous ont clairement permis de déterminer que les agonistes possèdent une efficacité et ou puissance différentes les uns par rapport aux autres. De plus, l’ordre d’efficacité des agonistes à moduler la voie de l’AMPc était (Prucalopride > Zacopride = ML10302 = 5-HT > RS67333) et est différente de leur ordre d’efficacité à induire la régulation du récepteur par internalisation (5-HT > Zacopride > Prucalopride > ML10302 = RS67333). Ainsi, nous avons montré que les 5-HT4Rs adoptent des conformations qui sont ligand-spécifiques. Cela implique que la sélectivité fonctionnelle serait un facteur important à considérer dans les mécanismes d’action antidépresseur des agonistes de ce récepteur. / Antidepressants currently available are very similar toward their mechanism of action and are more or less effective. One major problem is their long latency to provide a therapeutic effect due to adaptations of pre and post synaptic locations. In an animal model, we recently discovered that the agonist RS67333 of the 5-HT4 receptors was able to produce in three days the same antidepressant effects that normally take two to three weeks to appear with the currently available antidepressants. In addition, we found that the antidepressant effects of this agonist had a resistance to tolerance. There are others agonists of the same receptor such as prucalopride, which does not produce antidepressant effects as RS67333. Since the effectiveness of prucalopride to stimulate 5-HT4Rs is similar if not greater than RS67333, we stated the hypothesis that the 5-HT4 receptor could adopt different active conformations following its activation by various agonists. We decided to explore the major functional responses of 5-HT4B by observing their regulatory and signaling properties. We showed that the B isoform of the 5-HT4, being highly expressed in the limbic system, has a different signaling and regulation depending on the ligand. Our results indicate that each of the agonists tested (5-HT, RS67333, ML10302, Zacopride, Prucalopride) distinctively modulate cAMP production and receptor internalization. The results have clearly identified that agonists differed in potency and efficacy. Moreover, the order of effectiveness of agonists to modulate the cAMP pathway was (prucalopride> zacopride = 5-HT = ML10302> RS67333) different from their order of effectiveness in inducing receptor regulation by internalization (5-HT> Zacopride> Prucalopride> RS67333 = ML10302). Thus, we have shown that 5-HT4Rs adopt conformations that are ligand-specific. This implies that functional selectivity is an important factor in the mechanisms of antidepressant action of this receptor agonists.
900

Microdiffraction et microtomographie in situ des transformations hétérogènes du C¦" sous haute pression et haute température

Alvarez murga, Michelle jenice 06 November 2012 (has links) (PDF)
Le diagramme des phases du C60 continue d'être un sujet de discussion et de controverse, malgré la grande quantité de travaux expérimentaux et théoriques fait au fil des ans. Ceci est principalement dû au manque d'études in situ, a l'existence d'états désordonnés présentant des pics de diffraction très mal résolus et à la coexistence de plusieurs polytypes de faible densité. Ce manuscrit présente une étude systématique in situ des transformations hétérogènes du C60 sous haute pression et haute température dans la gamme 1-10 GPa et 300-1200 K. Afin de discriminer les poly(a)morphes de densité similaire dans des échantillons hétérogènes, nous avons utilisé une combinaison de micro-diffraction et micro-tomographie. Les échantillons ont été synthétisés dans une cellule Paris-Edimbourg et caractérisés à l'aide de diffraction des rayons X in situ en dispersion angulaire. Des images tridimensionnels à haute résolution ont été obtenus sur des échantillons trempés par la méthode de micro-tomographie de diffraction/diffusion. Cette méthode permet l'analyse 3D de l'intensité de diffusion reconstruite à partir de séries de projections 2D. Une telle analyse est non destructive et offre une grande sensibilité (0,1% en volume), une haute résolution spatiale (μm3) et peut être multimodale, fournissant des données quantitatives sur la morphologie, la densité, la composition élémentaire ou la structure des matériaux. En outre, nous décrivons le développement d'un système de micro-tomographie in situ sous haute pression et haute température en utilisant une nouvelle cellule rotative Paris-Edimbourg (RoToPEC), combinée avec le rayonnement synchrotron. La capacité à tourner complètement la chambre de l'échantillon sous charge, surmonte la contrainte d'ouverture angulaire limitée des cellules ordinaires et permet l'acquisition de projections tomographiques pour l'imagerie de plein champ ainsi que pour l'imagerie par micro-diffraction. Cette méthode innovante permet l'étude des matériaux sous conditions extrêmes de pression, température ou stress, et pourra être appliquée dans des domaines variés tels que la physique, la chimie, la science des matériaux ou la géologie. Le potentiel de cette nouvelle technique expérimentale est démontré par l'étude de la polymérisation de C60 sous haute-pression et haute température. Mots-clés: C60, diagramme de phase, diffraction, micro-tomographie, haute pression et haute température

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