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Transfert d'un composé organo-chloré depuis une zone source localisée en zone non saturée d'un aquifère poreux vers l'interface sol-air : expérimentations et modélisations associéesMarzougui, Salsabil 29 January 2013 (has links) (PDF)
Deux expériences ont été menées sur la plate-forme expérimentale "SCERES" afin d'évaluer les concentrations et les flux de vapeurs de TCE dans SCERES en présence de deux dalles de béton fissurées installées, l'une après l'autre, à la surface de SCERES. Cet aquifère poreux est un milieu hétérogène de grande échelle (25 x 12 x 3 m3). Les résultats ont montré que le panache de vapeur de TCE couvre la plupart du bassin au bout de 3 semaines depuis la création de la zone source de TCE dans le sous sol. L'hétérogénéité du site SCERES a engendrée une distribution verticale non uniforme de la concentration de vapeurs de TCE. La simulation du panache de vapeur dans SCERES a été effectuée au moyen du code de calcul multiphasique "SIMUSCOPP". La présence sur SCERES de la dalle de béton, un milieu peu perméable et peu diffusif, a constitué une "barrière" en vue du transfert de vapeurs de TCE vers l'interface dalle/atmosphère. Afin de mieux quantifier le flux de vapeurs à travers la dalle de béton, une étude de coefficient de diffusion et de perméabilité des deux dalles a été réalisée. Un mouvement vertical ascendant du toit de la nappe a généré un fort gradient de pression motrice de l'air du sol. Ceci a engendré une forte augmentation des flux de vapeurs à l'interface sol/atmosphère. La quantification de ces flux de vapeurs a été effectuée à l'aide d'une solution semi analytique basée sur la loi de Fick et la loi de Darcy en tenant compte à la fois de l'effet de gradient de pression motrice et l'effet de densité de vapeurs sur le transfert de vapeurs vers la surface du sol. L'intrusion de vapeurs de TCE dans le bâtiment modèle, installé sur la dalle de béton, a été générée par une mise en dépression dans ce dernier. Ce qui a fait augmenter la concentration de vapeurs de TCE sous la dalle ainsi dans le bâtiment. La simulation de l'intrusion de vapeurs dans l'air intérieur de bâtiment a été réalisée par l'intermédiaire du code de calcul multiphysics "COMSOL", avec lequel nous avons démontré l'évolution de la concentration de vapeurs obtenues expérimentalement dans le bâtiment et qui dépend directement de la variation spatio-temporelle du flux massique à travers la dalle.
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Implementation of Fast Fourier Transformation on Transport Triggered Architecture / Implementation of Fast Fourier Transformation on Transport Triggered ArchitectureŽádník, Jakub January 2017 (has links)
V této práci je navrhnut energeticky úsporný procesor typu TTA (Transport Triggered Architecture) pro výpočet rychlé Fourierovy transformace (FFT). Návrh procesoru byl vytvořen na míru použitému algoritmu pomocí speciáoních funkčních jednotek. Algoritmus byl realizován jako posloupnost instrukcí tak, že většina výpočtu probíhá ve smyčce obrahující pouze jedionu paralelní instrukci. Tato instrukce je umístěna do instrukčního bufferu, odkud je potom volána místo instrukční paměti. Díky tomu se dá docílit nižší spotřeby, neboť volání z instrukčního bufferu je efektivnější než volání z instrukční paměti. Program byl zkompilován na časovém modelu procesoru a časová simulace potvrdila správnost návrhu. Součástí práce jsou rovněž pomocné programy v Pythonu, které slouží ke generaci referenčních výsledků a automatické simulaci a porovnání výsledků simulace s referencí.
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Vliv národní identity na české postoje k evropské integraci / The impact of national identity on Czech position towards European integrationKim, Min Sun January 2021 (has links)
The Czech Republic has been regarded as a little troublemaker of the EU due to its Eurosceptic stances. This phenomenon was distinct in the 2000s regardless of the state's position, whether it was just an EU candidate or already a member state. Around the time, President Vacláv Klaus and his political party (ODS), as Czech leadership, contributed to promoting the Eurosceptic governments towards the EU. It could be seen as strange that such a trait was revealed both in the midst of preparations to join the EU and after its accession when it is the proper time to present a cooperative attitude. Thus, this thesis speculates that the skeptical national identity of the Czech Republic has been constructed throughout history, particularly about 450 years from the Bohemia Kingdom to Czechoslovakia (1525~1971), and affected then Czech domestic politics to formulate the official Eurosceptic positions towards the several EU integration matters (constitutional, security, and monetary integrations). In this context, this master's thesis aims to find an objective correlation that Czech identity had an influence on then Czech Euroscepticism. This way, this thesis expects to advance knowledge concerning Czech identity and its relevance to European politics.
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The (In)ability of the International Intellectual Property Regime to Adequately Protect Traditional Knowledge and Traditional Cultural Expressions : A Legal Analysis on the Intellectual Property Protection of Traditional Knowledge and Traditional Cultural Expressions in the Context of Sustainable DevelopmentMakipour, Sanam January 2023 (has links)
No description available.
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Review of the Sanctioning Power in Public Procurement: About the Plenary Court Agreement 1/2015-TCE issued by the State Procurement Court / Revisión de la Potestad Sancionadora en Contratación Pública: A propósito del Acuerdo de Sala Plena 1/2015-TCE emitido por el Tribunal de Contrataciones del EstadoRubio Salcedo, César Rommel 10 April 2018 (has links)
On the basis of the revision of the power to impose on government procurement matter, the author analyses the content and scope of Plenary Court agreement 1/2015-TCE; to the light of the juridical and factual that will occur with the emission and issue of this binding precedent.In addition, the author works a prediction of the eventual contradictions on the application of the Plenary Court agreement that may occur in the juridical administrative system and the harmful consequences of the effectiveness of it. / A partir de la revisión de la potestad sancionadora en materia de contratación pública, elautor analiza el contenido y los alcances del Acuerdo de Sala Plena 1/2015-TCE; a la luz de las implicancias jurídicas y fácticas que se presentarán con la emisión y publicación de este precedente vinculante.Adicionalmente, se prevé las eventuales contradicciones en que la aplicación de este Acuerdo de Sala Plena puede generar en el ordenamiento jurídico administrativo; así como las nefastas consecuencias de su vigencia.
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Organisational and Workforce Restructuring in a Deregulated Environment: A Comparative Study of The Telecom Corporation of New Zealand (TCNZ) and TelstraRoss, Peter, n/a January 2003 (has links)
In the late 1980s, governments in New Zealand and Australia began to deregulate their telecommunications markets. This process included the corporatisation and privatisation of former state owned telecommunications monopolies and the introduction of competition. The Telecom Corporation of New Zealand (TCNZ) was corporatised in 1987 and privatised in 1990. Its Australian counterpart, Telstra, was corporatised in 1989 and partially privatised in 1997. This thesis examines and compares TCNZ and Telstra's changing organisational and workforce restructuring strategies, as they responded to these changes. It further examines how these strategies influenced the firms' employment relations (ER) policies. Strategic human resource management (SHRM) and transaction costs economics (TCE) theories assist in this analyse. TCE links organisational restructuring to the make/buy decisions of firms and the asset-specificity of their employees. It suggests that firms will retain workers that have developed a high degree of firm-specific skills, and outsource more generic and semi-skilled work. Firm strategies are also influenced by national, contextual, factors. From a TCE perspective, these external factors alter relative transaction costs. Hence, different ownership structures, ER legislation and union power help to explain differences in TCNZ and Telstra's organisational restructuring and ER strategies. During the decade from 1990 to 2000, TCNZ and Telstra cut labour costs through large-scale downsizing programs. Job cuts were supported by outsourcing, work intensification and the introduction of new technologies. These initial downsizing programs were carried out through voluntary redundancies, across most sections of the firms. In many instances workers simply self-selected themselves for redundancies. TCNZ and Telstra's downsizing strategies then became more strategic, as they targeted generic and semi-skilled work for outsourcing. These strategies accorded with a TCE analysis. But TCNZ and Telstra engaged in other practices that did not accord with a TCE analysis. For example, both firms outsourced higher skilled technical work. TCNZ and Telstra's continued market domination and the emphasis that modern markets place on short term profits, provided possible reasons for these latter strategies. This thesis suggests, therefore, that while TCE may help to predict broad trends in 'rational organisations', it may be less effective in predicting the behaviour of more politically and ideologically driven organisations aiming for short term profit maximisation. Some TCNZ and Telstra workers were shifted to subsidiaries and strategic alliances, which now assumed responsibility for work that had previously been performed in-house. Many of these external firms re-employed these workers under more 'flexible' employment conditions. TCNZ and Telstra shifted to more unitarist ER strategies with their core workers and reduced union influence in the workplace. Unions at Telstra were relatively more successful in retaining members than their counterparts at TCNZ. By 2002, TCNZ and Telstra had changed from stand-alone public sector organisations, into 'leaner' commercially driven firms, linked to subsidiaries, subcontractors and strategic alliances.
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Cooling Of Electronics With Phase Change Materials Under Constant Power And Cyclic Heat LoadsSaha, Sandip Kumar 02 1900 (has links)
The trend in the electronic and electrical equipment industry towards denser and more powerful product requires a higher level of performance from cooling devices. In this context, passive cooling techniques such as latent heat storage systems have attracted considerable attention in recent years. Phase change materials (PCMs) have turned out to be extremely advantageous in this regard as they absorb high amount of latent heat without much rise of temperature. But unfortunately, nearly all phase change materials (PCMs) with high latent heat storage capacity have unacceptably low thermal conductivity, which makes heating and cooling processes slow during melting and solidification of PCMs. Augmentation of heat transfer in a PCM is achieved by inserting a high thermal conductivity material, known as thermal conductivity enhancer (TCE), into the PCM. The conglomeration of PCM and TCE is known as a thermal storage unit (TSU).
In this thesis, detailed and systematic analyses are presented on the thermal performance of TSUs subjected to two types of thermal loading- (a) constant power loading in which a constant power level is supplied to the chip (heater) for a limited duration of time, and (b) cyclic loading. Eicosane is used as the PCM, while aluminium pin or plate fins are used as TCEs.
First, a 1-D analytical model is developed to obtain a closed-form temperature distribution for a simple PCM domain (without TCE) heated uniformly from the bottom. The entire heating process is divided into three stages, viz. (a) sensible heating period before melting, during which heat is stored in the solid PCM in the form of specific heat,
(b) melting period, during which a melt front progresses from the bottom to the top layer of the PCM and heat is stored in latent as well as in sensible forms, and (c) post melting period, during which energy is stored again in the form of sensible heat. For each stage, conduction energy equation is solved with a set of initial and boundary conditions. Subsequently, a resistance capacitance model of phase change process is developed for further analysis.
For transient performance under constant thermal loading, experimental investigations are carried out for TSUs with different percentages of TCE. A numerical model is developed to interpret the experimental results. The thermal performance of a TSU is found to depend on a number of geometrical parameters and boundary conditions. Hence, a systematic approach is desirable for finding the best TSU design for which the chip can be operated for a longer period of time before it reaches a critical temperature (defined as the temperature above which the chip starts malfunctioning). As a first step of the approach, it is required to identify the parameters which can affect the transient process. It is found that the convective heat transfer coefficient, ‘h’ and the exposed area for heat transfer have little effect on the chip temperature during the constant power operation. A randomized search technique, Genetic Algorithm (GA), is coupled with the CFD code to find an optimum combination of geometrical parameters of TSUs based on the design criteria. First, the optimization is carried out without considering melt convection within the PCM. It is found that the optimum half-fin width remains fixed for a given heat flux and temperature difference. Assuming a quasi steady process, the results of optimization are then explained by constructing and analyzing a resistance network model. The resistance network model is then extended to include the effect of melt convection, and it is shown that the optimum pitch changes with the strength of convection. Accordingly, numerical analysis is carried out by considering the effect of melt convection, and a correlation for optimum pitch is developed.
Having established the role of melt convection on the thermal performance of TSUs, rigorous computational and experimental studies are performed in order to develop correlations among different non-dimensional numbers, such as Nusselt number, Rayleigh number, Stefan number and Fourier number, based on a characteristic length scale for convection. The enclosures are classified into three types, depending on the aspect ratio of cavity, viz. shallow, rectangular and tall enclosures. For a shallow enclosure, the characteristic length is the height of cavity whereas for a tall enclosure, the characteristic length is the fin pitch. In case of rectangular enclosure, both pitch and height are the important characteristic lengths.
For cyclic operation, it is required that the fraction of the PCM melting during the heating cycle should completely solidify back during the cooling period, in order that that TSU can be operated for an unlimited number of cycles. If solidification is not complete during the cooling period, the TSU temperature will tend to rise with every cycle, thus making it un-operational after some cycles. It is found that the solidification process during the cooling period depends strongly on the heat transfer coefficient and the cooling surface area. However, heat transfer coefficient does not play any significant role during the heating period; hence a TSU optimized for transient operation may not be ideal for cyclic loading. Accordingly, studies are carried out to find the parameters which could influence the behaviour of PCM under cyclic loading. A number of parameters are identified in the process, viz. cycle period and heat transfer coefficient. It is found that the required heat transfer coefficient for infinite cyclic operation is very high and unrealistic with air cooling from the surface of the TSU. Otherwise, the required cooling period for complete re-solidification will be very high, which may not be suitable for most applications.
In an effort to bring down the cooling period to a duration that is comparable to the heating period, a new design is proposed where both ‘h’ and area exposed to heat transfer can be controlled. In this new design, the gaps between the fins in a plate-fin TSU are alternately filled with PCM, such that only one side of a fin is in contact with PCM and the other side is exposed to the coolant (air). In this arrangement, the same heat flow path through the fin which is used for heating the PCM (during the heating stage) can also be used for cooling and solidifying the PCM during the cooling part of the cycle. Natural or forced air cooling through the passages can be introduced to provide a wide range of heat transfer coefficient which can satisfy the cooling requirements. With this arrangement, the enhanced area provided for cooling keeps the ‘h’ requirement within a realistic limit. This cooling method developed is categorized as a combination of active and passive cooling techniques. Analytical and numerical investigations are carried out to evaluate the thermal performance of this modified PCM-based heat sink in comparison to the ones with conventional designs. It is found that, the performance of new PCM-based heat sink is superior to that of the conventional one. Experiments are performed on both the conventional and the new PCM-based heat sinks to validate the new findings.
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The Focal Reducing Imager and Spectrograph FORS, built for the optical 16-metre ‘Very Large Telescope’ of the European Southern Observatory / Der Fokal-Reduktor und Spektrograph FORS, entwickelt für das optische 16-meter ‘Very Large Telescope’ des Europäischen Süd-ObservatoriumsNicklas, Harald 04 July 2005 (has links)
No description available.
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Etude numérique et expérimentale des transferts de Composés Organiques Volatils du sol à l'air ambiant, en passant au travers du bétonMusielak, Marion 19 October 2012 (has links) (PDF)
Cette thèse fait partie du projet FLUXOBAT (ANR-PRECODD 2008), qui a pour objectif global de développer une méthodologie robuste et fiable d'estimation des transferts de Composés Organiques Volatils (COV) du milieu souterrain vers l'air intérieur et extérieur. Ce travail concerne l'étude à l'échelle du laboratoire des transferts d'un COV type, le trichloréthylène (TCE), au travers d'un sol modèle (sable) et surtout du béton, en conditions isothermes et pour des milieux secs. Les moyens utilisés sont la modélisation numérique et une série d'expériences en laboratoire. Une étude préliminaire reproduisant des expériences existant dans la littérature dans le sable uniquement, a tout d'abord permis de mettre en place les outils expérimentaux et numériques nécessaires à la modélisation du problème, avant la réalisation de l'étude sur le matériau béton, bien plus complexe. L'étude des transferts dans le béton a été divisée en plusieurs étapes. Dans un premier temps, les transferts dans la pâte de ciment, plus homogène, ont été caractérisés. En particulier, la valeur du coefficient de sorption du TCE dans ce matériau a été obtenue à l'aide du suivi expérimental de la réponse à un " pulse " de polluant. Puis, les paramètres caractéristiques (porosité, perméabilité, ouverture des fissures, coefficient de diffusion effectif) des échantillons tests de " béton complet " ont été mesurés. Un protocole de caractérisation complète des galettes de béton a été mis au point, associé à la création d'un dispositif permettant la mise en place d'expériences de transferts du TCE (composé dont l'étude est complexifiée par son caractère particulièrement agressif) et applicables à tout milieu poreux consolidé. La problématique de l'hétérogénéité du béton, due à la présence de granulats et de fissures, a été traitée afin de proposer des équations de transfert moyennées donnant une meilleure description des transferts. Les conditions d'un cas de pollution " réel " ont été reproduites à l'échelle du laboratoire, sur un modèle réduit, dans une colonne de sable surmontée d'une galette de béton et d'une cavité en dépression représentant un bâtiment, pour étudier les transferts de TCE et valider la caractérisation développée dans l'étude. Les expériences de transferts réalisées sont reproductibles, ont été interprétées numériquement (sous Comsol multiphysics®), et ont permis de confirmer la pertinence de la simulation des transferts à l'aide de la caractérisation développée dans cette étude. Ce travail a permis de mettre, en particulier, en évidence l'importance de la caractérisation fine du béton, dont les propriétés et l'hétérogénéité sont des facteurs très influents sur les transferts, qui ne peuvent pas être décrits correctement avec des modèles analytiques simplifiés. Les résultats comportent l'estimation des paramètres caractérisant les transferts de COV dans le béton, et une compréhension fine des transferts du TCE dans ce matériau.
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O papel da enzima Na+,K+-ATPase no déficit cognitivo e no efeito profilático induzido pelo exercício físico após o Traumatismo Crânio-Encefálico / The role of Na+,K+-ATPase enzyme on cognitive deficit and in the prophylactic effect induced by exercise after Traumatic Brain InjuryLima, Frederico Diniz 17 September 2009 (has links)
Traumatic Brain Injury (TBI) is the major cause of death or cognitive deficits in industrialized countries. Although studies have indicate that the oxidative stress and functional deficits after TBI are connected events, the mechanisms that outline the development of these cognitive deficits are, still, limited. In this context, we
investigated the involvement of oxidative stress markers (thiobarbituric acid reactive species; TBARS and protein carbonylation) and the Na+,K+-ATPase enzyme activity
on the spatial learning after one and three months from a fluid percussion injury (FPI) in rats. The results revealed that FPI increase the latency of escape and the number of the errors on the Barnes Maze Test one and three months after FPI. We also found an increase of TBARS and protein carbonylation in parietal cortex after one and three months FPI. In addition, statistical analysis revealed a decrease of the Na+,K+- ATPase enzyme activity in the parietal cortex after FPI (time-dependent). These
results suggest that cognitive impairment following FPI may result, at least in part, from increase of two oxidative stress markers, protein carbonylation and TBARS that occurs concomitantly to a decrease in Na+,K+-ATPase activity. Physical exercise, despite the involvement on the generation of the reactive oxygen species (ROS), is
used on the rehabilitation of TBI. However, although the favorable effects of physical exercise on traumatic brain injury (TBI) patients is well known, the specific
mechanisms involved in this protection after TBI has been limited. Thus, we investigated whether physical training protects against oxidative damage (measured by protein carbonylation and TBARS) and neurochemical alterations represented by immunodetection of alpha subunit and activity of Na+,K+-ATPase after FPI in cerebral cortex of rats. The results revealed that physical training protected against oxidative damage induced by FPI. In addition, physical training was effective against Na+,K+-
ATPase enzyme activity inhibition and α subunit level decrease after FPI. The Pearson correlation showed that the decrease of the catalytical levels of the Na+,K+-
ATPase enzyme α subunit is related with the increasing on oxidative stress markers. Moreover, the physical activity-related protection against free radicals induced by FPI
links with maintenance of α subunit immunocontent. These results suggest that the effective protection stimulated by physical exercise on the neuronal damage induced
by TBI has connection with the protection of the specific targets from the free radicals action, like Na+,K+-ATPase enzyme. / O Traumatismo crânio-encefálico (TCE) é uma das maiores causas de morte ou déficits cognitivos nos países industrializados. Apesar de os estudos indicarem que o
estresse oxidativo e os déficits funcionais que ocorrem após TCE serem eventos interrelacionados, os mecanismos que delineiam o desenvolvimento destes déficits cognitivos
são, ainda, limitados. Neste contexto nós investigamos o envolvimento de marcadores de estresse oxidativo (espécies reativas ao ácido tiobarbitúrico; TBARS e carbonilação
protéica) e a atividade da enzima Na+,K+-ATPase no aprendizado espacial um e três meses após um dano de percussão por fluído (FPI) em ratos. Os resultados revelaram que o FPI aumentou o tempo de latência e o número de erros no teste do labirinto de Barnes em um e três meses após FPI. Também encontramos aumento no conteúdo de TBARS e proteína carbonil no córtex parietal em um e três meses após FPI. Além disso, a análise estatística revelou uma diminuição na atividade da enzima Na+,K+-ATPase no córtex cerebral após FPI tempo dependente, sugerindo que o déficit cognitivo induzido pelo FPI se deva pela perda de funcionabilidade de enzimas presentes na células como Na+,K+-ATPase. Perda esta induzida pelo aumento na geração de radicais livres após TCE. Apesar de estar envolvido no aumento da produção de espécies reativas ao Oxigênio (ERO), exercício físico tem sido
utilizado na reabilitação de após TCE. Por outro lado, ainda são escassos na literatura estudos que evidenciam a especificidade dos mecanismos envolvidos na proteção induzida pelo exercício físico após TCE. Desta forma, investigamos se o treinamento físico protege contra o dano oxidativo bem como das alterações neuroquímicas representadas pela imunodetecção da subunidade α e da atividade da enzima Na+,K+-ATPase no córtex cerebral de ratos. Os resultados revelaram que o treinamento físico protegeu contra o dano oxidativo induzido por FPI. Além disso, o treinamento físico foi efetivo contra a inibição da
enzima Na+,K+-ATPase e a diminuição dos níveis da sua subunidade α após FPI. A correlação de Pearson revelou que a diminuição dos níveis catalíticos da subunidade α da
enzima Na+,K+-ATPase se correlaciona com o aumento dos marcadores de estresse oxidativo. Além disso, a proteção exercida pela atividade física contra os radicais livres
induzidos por FPI tem relação com a manutenção do imunoconteúdo da subunidade α. A partir destes achados, sugere-se que a efetiva proteção exercida pelo exercício físico no dano neuronal causado induzido pelo TCE se deva pela proteção de alvos específicos a ação de radicais livres, como a enzima Na+, K+-ATPase.
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