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Van, Drooge Barend L. "Long-range atmospheric transpod and fate of persistent organic pollutants in remote mountain areas." Doctoral thesis, Universitat Autònoma de Barcelona, 2004. http://hdl.handle.net/10803/3660.
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Kazemzadeh, Osgoei Bentolhoda. "Conception d’un système de transmission haut débit dans un canal doublement sélectif : système de TransPod." Electronic Thesis or Diss., Limoges, 2024. http://www.theses.fr/2024LIMO0055.
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Cette thèse explore la modélisation des canaux et la conception de la couche physique pour améliorer les communications à haut débit dans les canaux sans fil à haute mobilité, en se concentrant spécifiquement sur le système TransPod. Le travail commence par une revue complète des canaux sans fil, en se focalisant sur les canaux doublement sélectifs, leurs dégradations, et les techniques de modulation telles que OFDM et OTFS. Nous caractérisons ensuite le canal de transmission du guide TransPod, en examinant à la fois les caractéristiques à grande échelle et à petite échelle, et en traitant le bruit provenant du système de transmission de puissance basé sur le plasma. Un système de communication à double liaison est proposé pour atténuer les déconnexions fréquentes. Nous proposons une nouvelle technique d’estimation de canal basée sur des pilotes pour les systèmes OTFS dans le domaine retard-Doppler, et introduisons une méthode d’estimation du canal Doppler fractionnaire basée sur l’apprentissage automatique utilisant les deep neural networkThis thesis explores channel modeling and physical layer design to enhance high data rate communications in high mobility wireless channels, with a specific focus on the TransPod system. The work begins with a comprehensive review of wireless channels, focusing on doubly selective channels, their impairments, and modulation techniques such as OFDM and OTFS. We then characterize the TransPod guideway transmission channel, examining both large-scale and small-scale characteristics, and addressing noise from the plasma-based power transmission system. A dual-link communication system is proposed to mitigate frequent disconnectivity. We propose a novel sequence-pilot-based channel estimation technique for OTFS systems in delay-Doppler domain and introduce a machine learning-based method for fractional Doppler channel estimation using deep neural network
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Hrabetova, Sabina, Ang Sherpa, and Fanrong Xiao. "Diffusive spread of substance through brain extracellular space in in vitro model of sleep and awake brain states." Universitätsbibliothek Leipzig, 2016. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-198264.
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Desaunay, Aurélien. "Etude et modélisation de la biosorption des métaux par les bactéries. Application au transfert du cadmium et du zinc, seuls ou en mélange par Escherichia coli et Cupriavidus metallidurans en colonnes de sable d'Hostun." Thesis, Grenoble, 2011. http://www.theses.fr/2011GRENU049/document.
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Recent field observations have demonstrated that supposedly poorly mobile metals can be detected at long distances from their source, highlighting the importance of poorly predicted transport processes. The fast mobilisation of metals by the colloidal and mobile fraction of soils and in particular biotic colloids (bacteria, algae, fungi, virus, etc.), is now identified as an important secondary transport process that can lead, under specific conditions, to accelerated and potentially dominant pollutant transfer towards aquifers. In order to better understand the role of the bacterial compartment of soils to metal leaching, we conducted a coupled study under static and dynamic conditions. Firstly we evaluated Zn and Cd metal biosorption onto active or inactive Gram negative bacteria (Escherichia coli and Cupriavidus metallidurans CH34) by characterizing the sub-cellular distribution of the metals through a cell disruption approach. The quantification of Zn and Cd in extracellular, membrane and cytoplasm compartments of the cells permitted to show that metals are unequally distributed between the three cell compartments and also between the two bacteria. Surprisingly, metals internalization appeared to be the dominant accumulation process of metals (high cytoplasm contents). The physiological state of the cells was also shown to be important in metal management by the bacteria, since metal accumulation in active cells was reduced due to enhanced efflux and/or EPS production mechanisms. These results suggest bacteria can internalize important amounts of heavy metals and also that adsorption onto cell surface is only a first step in metal management by bacteria. The so-determined thermo-dynamic reactivity constants were used to fit metal breakthrough curves performed in natural sand columns. The transport experiments of bacterial cells, metals or mixtures of bacteria and/or metals performed in the second part of the study, demonstrated that bacteria are able to accelerate the in situ mobilization of Cd and Zn retained in natural sand columns. This transport process was shown to be dominant upon aqueous transport and was correctly fitted using a combined transfer and geochemical modelling approach. Altogether, these results showed that, under specific conditions, heavy metal transport by bacterial cells can dominate aqueous transport processes in soilsRecent field observations have demonstrated that supposedly poorly mobile metals can be detected at long distances from their source, highlighting the importance of poorly predicted transport processes. The fast mobilisation of metals by the colloidal and mobile fraction of soils and in particular biotic colloids (bacteria, algae, fungi, virus, etc.), is now identified as an important secondary transport process that can lead, under specific conditions, to accelerated and potentially dominant pollutant transfer towards aquifers. In order to better understand the role of the bacterial compartment of soils to metal leaching, we conducted a coupled study under static and dynamic conditions. Firstly we evaluated Zn and Cd metal biosorption onto active or inactive Gram negative bacteria (Escherichia coli and Cupriavidus metallidurans CH34) by characterizing the sub-cellular distribution of the metals through a cell disruption approach. The quantification of Zn and Cd in extracellular, membrane and cytoplasm compartments of the cells permitted to show that metals are unequally distributed between the three cell compartments and also between the two bacteria. Surprisingly, metals internalization appeared to be the dominant accumulation process of metals (high cytoplasm contents). The physiological state of the cells was also shown to be important in metal management by the bacteria, since metal accumulation in active cells was reduced due to enhanced efflux and/or EPS production mechanisms. These results suggest bacteria can internalize important amounts of heavy metals and also that adsorption onto cell surface is only a first step in metal management by bacteria. The so-determined thermo-dynamic reactivity constants were used to fit metal breakthrough curves performed in natural sand columns. The transport experiments of bacterial cells, metals or mixtures of bacteria and/or metals performed in the second part of the study, demonstrated that bacteria are able to accelerate the in situ mobilization of Cd and Zn retained in natural sand columns. This transport process was shown to be dominant upon aqueous transport and was correctly fitted using a combined transfer and geochemical modelling approach. Altogether, these results showed that, under specific conditions, heavy metal transport by bacterial cells can dominate aqueous transport processes in soils
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Klein, Sarah. "Application des outils de la physique statistique au transport intracellulaire." Thesis, Université Paris-Saclay (ComUE), 2016. http://www.theses.fr/2016SACLS090/document.
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La plupart des processus dans notre vie quotidienne sont des processus hors équilibre. Un exemple de système hors équilibre est la cellule biologique et le transport qui a lieu dedans. Dans cette thèse ce transport intracellulaire est modélisé par des processus stochastiques. Pour cela deux approches différentes ont été utilisées : d’une part une modélisation explicite de particules actives avec des degrés de liberté internes obtenus expérimentalement, d’autre part une description phénoménologique des effets collectifs, qui est réalisée au moyen de processus d’exclusion.Un des résultats principaux pour le modèle explicite est qu’il est crucial de prendre en compte les fluctuations des forces pour reproduire les caractéristiques principales du mou- vement. Un autre élément important est la prise en considération de l’environnement cellu- laire, qui peut produire des effets non-triviaux, comme par exemple une inversion du sens de déplacement moyen. Pour étudier les effets collectifs il est possible de représenter le mou- vement des particules d’une manière simplifiée, en utilisant un processus d’exclusion avec des particules ayant des états internes. Le désordre sur les taux de saut qui en résulte peut provoquer une condensation dépendant de la densité.Un autre modèle étudié est un processus d’exclusion sur un réseau à deux voies. On suppose que deux types de particules se déplacent dans une géométrie tubulaire, inspirée par les champignons filamenteux. Ces hypothèses définissent un modèle minimal qui présente une transition de phase d’une phase de basse densité vers une phase pulsante caractérisée par des oscillations de densitéMost processes in our daily life are far from equilibrium. The prime example is a cell and the transport occurring within. In this thesis intracellular transport is modeled by means of stochastic processes. For this, two different approaches are applied: the explicit mod- eling of active particles with internal degrees of freedom with characteristics as they were determined experimentally. And secondly, the collective effects occurring in many particle systems are studied in a phenomenological way by means of exclusion processes.In the explicit model one important result is given by the fact that force fluctuations are essential to capture the relevant motion characteristics. Further, the influence of the cellular environment creates counter-intuitive effects, like a possible inversion of the bias. The motion characteristics can be represented in a coarse-grained manner as an exclusion process for particles with internal states. Due to the resulting disorder in the hopping rates a density-dependent condensation occurs.In a second part, a two-lane exclusion model is studied. Two species in a tubular geometry inspired by filamentous fungi are considered.This can be seen as a minimal model exhibiting a phase transition from a low density phase to an intriguing phase with periodically changing particle densities
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Hrabetova, Sabina, Ang Sherpa, and Fanrong Xiao. "Diffusive spread of substance through brain extracellular space in in vitro model of sleep and awake brain states: Diffusive spread of substance through brain extracellular space in in vitromodel of sleep and awake brain states." Diffusion fundamentals 24 (2015) 23, S. 1, 2015. https://ul.qucosa.de/id/qucosa%3A14539.
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Louis, Michel. "Architecture et acces d'un frontal de communication a transpac, transcom et transdyn : association de voies terrestres a des liaisons transdyn unidirectionnelles." Paris 6, 1988. http://www.theses.fr/1988PA066374.
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Description d'un frontal de communication multiprocessus. Mise en uvre de liaisons transdyn basees sur des liaisons par satellite telecom1 au moyen de la classe 4 du protocole de transport iso. Definition du protocole de transport pour la diffusion de donnees proche de la classe 4 du protocole iso
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Louis, Michel. "Architecture et accès d'un frontal de communication à TRANSPAC, TRANSCOM et TRANSDYN association de voies terrestres à des liaisons TRANSDYN unidirectionnelles /." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37615364v.
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Yeung, Sau-fung Lorraine, and 楊秀鳳. "Transport planning in Hong Kong: cross borderfreight transport." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1995. http://hub.hku.hk/bib/B42574456.
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Rajbhandari, Bidur. "Modelling intelligent transport systems applications for public transport." Thesis, University of Southampton, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246885.
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Armstrong, Amrith. "Road Freight Transport : Transport Purchasing and Environmental Impacts." Thesis, Högskolan i Borås, Institutionen Ingenjörshögskolan, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hb:diva-17527.
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This paper on the environmental impacts of transport purchasing in road freight is to highlight how the adaptive capability of transport chains are affected through collaboration and the aim for sustainability through political regulations and societal demands.This paper is divided into a theoretical framework and an empirical study, followed by the analysis, conclusions and discussions based on the framework and empirical study.The theoretical framework will discuss the different aspects of road freight transport which impact the environment and show the interdependencies of each aspect.The analysis will highlight the empirical chapter with a comparison of the theoretical framework in order to make substantial conclusions.Conclusions among others are that standardization is needed although flexibility and agility is also needed. By standardizing processes, routine measures can be implemented and it creates a sense of certainty within the company. Agility and flexibility can be achieved by adding modular processes which can be implemented if the need for customization arises.Governmental involvement is necessary for the development of infrastructure to minimize traffic congestion and improve the infrastructure for increased reliability, accessibility, and flexibility. By developing the rail infrastructure, a larger share of goods can be transferred via railway and thus reduce the environmental impacts of road freight through intermodal transportation.Program: Industrial Engineering – Logistics Management
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MOHAMMAD, ZADEHVADGHA ALIREZA. "Transport combine." Nantes, 1989. http://www.theses.fr/1989NANT4005.
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L'aspect technique economique du transport combine, la conteneurisation le conteneur et ses caracteristiques, le ferroutage et ses differentes techniques; la technique porte-barge, technique de transroulage, le navire roulier, technique de translevage: le navire porte-conteneurs, le conteneur aerien. La conteneurisation et les pays en voie de developpement. Les aspects juridiques du transport combine, le document de transport combine, l'entrepreneur de transport combine, le commissionnaire de transport en droit francais, le regime juridique du transport combine, la notion de colis, la clause "said to contain", le conteneur en pontee, le regime unique de responsabilite pour l'etc, la liberte contractuelle. Systemereseau, systeme uniforme, le fondement de la responsabilite, l'assurance et le systeme de responsabilite, le systeme de responsabilite instaure par la convention de geneve du 24 mai 1980The economic technical aspect of international transportation, the containerisation, the container and its characteristics, rail and road transportation and its varioustechniques, the "porte-barge" technique, the roll-on technique, the roll-on-roll-off ship, lift technique, the container ship, the containerfor air transportation. The containerisation and 3rd world countries. The juridical aspects of intermodal transportation, the intermodal transportation document, the intermodal transportation entrepreneur, the transportation commissionary in frenchlaw, the juridical system of intermodal transportation, the notion of "package", the "said to contain" clause, the container on deck, the sole system of responsability for etc (itc), contractual liberty, network system, uniform system, the basis of responsability, insurance and the system of responsability, the system of responsability created by the geneva convention on may 24th, 1980
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Monbourquette, Vincent. "Optimisation de réseaux de transport : transport de bois brut inter-usine & transport de copeaux." Master's thesis, Université Laval, 2016. http://hdl.handle.net/20.500.11794/27554.
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Ce mémoire présente les résultats de projets d'optimisation de réseaux de transport de l'entreprise Produit Forestier Résolu (PFR). Ces réseaux traitent, dans un cas, du transport de bois brut inter-usine et dans l'autre, de l'approvisionnement et du transport de copeaux vers les papetières. Le projet du transport de bois brut inter-usine cherche à développer un outil d'optimisation pour effectuer la planification du transport du bois brut entre les différentes étapes de production, soit le sciage, le séchage et le planage. Ce projet s'avère nécessaire en raison du contexte opérationnel de PFR, qui possède plusieurs petites usines avec des capacités différentes à chaque étape, demandant donc le transport de produits à différents moments. Le projet se restreint au territoire du Lac Saint-Jean, au Québec. Ce projet est complexe notamment en raison de la gestion des chargements; comme il s'agit de paquets de bois de toutes longueurs et dimensions, il n'est pas possible de simplement considérer une caractéristique physique pour remplir le camion. Les résultats sont prometteurs et proposent, outre une réduction significative du temps de planification, des gains allant de 1200 à 3000$ pour une période de deux semaines. Du côté du transport de copeaux, l'objectif est également de créer un outil d'optimisation, cette fois pour gérer l'approvisionnement en copeaux des papetières de PFR à travers la province de Québec. Ici, le défi est de considérer les recettes de productions aux papetières et d'assurer l'approvisionnement en tenant compte des différents mélanges d'essences aux scieries et les contraintes d'entreposage aux papetières. En raison de l'ampleur du réseau, les résultats sont significatifs, proposant des gains allant de 180 000 à 475 000$ pour une période de 4 semaines, en plus de faciliter la production de différents scénarios étudiant diverses hypothèses.
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Benjamin, Daniel. "Thermal transport and photo-induced charge transport in graphene." Diss., Georgia Institute of Technology, 2011. http://hdl.handle.net/1853/42746.
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The electronic material graphene has attracted much attention for its unique physical properties such as, linear band structure, high electron mobility, and room temperature ballistic conduction. The possibilities for device applications utilizing graphene show great variety, from transistors for computing to chemical sensors. Yet, there are still several basic physical properties such as thermal conductivity that need to be determined accurately.
This work examines the thermal properties of graphene grown by the chemical vapor deposition technique. The thermoelectric power of graphene is studied in ambient and vacuum environments and is shown to be highly sensitive to surface charge doping. Exploiting this effect, we study the change in thermoelectric power due to introduction of gaseous species. The temperature dependent thermal conductivity of graphene is measured using a comparison method. We show that the major contribution to the thermal conductivity is the scattering of in-plane phonons.
Graphene also shows promise as an optoelectronic material. We probe the Landau level structure of graphene in high magnetic fields using a differential photoconductivity technique. Using this method we observed the lifting of spin and valley degeneracies of the lowest Landau level in graphene.
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Bjarnason, Jónas. "Optimized Transport Planning through Coordinated Collaboration between Transport Companies." Thesis, KTH, Optimeringslära och systemteori, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-134095.
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This thesis studies a specific transport planning problem, which is based on a realistic scenario in the transport industry and deals with the delivery of goods by transport companies to their customers. The main aspect of the planning problem is to consider if each company should deliver the cargo on its own or through a collaboration of companies, in which the companies share the deliveries. In order to find out whether or not collaboration should take place, the transport planning problem is represented in terms of a mathematical optimization problem, which is formulated by using a column generation method and whose objective function involves minimization of costs. Three different solution cases are considered where each of them takes into account different combinations of vehicles used for delivering the cargo as well as the different maximum allowed driving time of the vehicles. The goal of the thesis is twofold; firstly, to see if the optimization problem can be solved and secondly, in case the problem is solvable, investigate whether it is beneficial for transport companies to collaborate under the aforementioned circumstances in order to incur lower costs in all instances considered. It turns out that both goals are achieved. To achieve the first goal, a few simplifications need to be made. The simplifications pertain both to the formulation of the problem and its implementation, as it is not only difficult to formulate a transport planning problem of this kind with respect to real life situations, but the problem is also difficult to solve due to its computational complexity. As for the second goal of the thesis, a numerical comparison between the different instances for the two scenarios demonstrates that the costs according to collaborative transport planning turns out to be considerably lower, which suggests that, under the circumstances considered in the thesis, collaboration between transport companies is beneficial for the companies involved.
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Lumsdon, Leslie Malcolm. "Tourism transport : an investigation of non-motorised tourism transport." Thesis, Staffordshire University, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341403.
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Mettier, Ralph. "Mass transport in fractured media transition to anomalous transport /." [S.l. : s.n.], 2007.
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Yeung, Sau-fung Lorraine. "Transport planning in Hong Kong : cross border freight transport /." Click to view the E-thesis via HKUTO, 1995. http://sunzi.lib.hku.hk/hkuto/record/B42574456.
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PAROLIN, ALBERTA. "Cities and transpor networks : comparative atlas." Doctoral thesis, Università IUAV di Venezia, 2009. http://hdl.handle.net/11578/278148.
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Luk, Yiu-wah Everett, and 陸耀華. "Potential applications of intelligent transport systems in urban freight transport." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2004. http://hub.hku.hk/bib/B29851397.
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Mbiydzenyuy, Gideon. "Quantitative Assessment of Intelligent Transport Systems for Road Freight Transport." Doctoral thesis, Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:bth-00553.
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In this thesis, methods for using computer-based models as support tools for assessing Transport Telematic Services (TTSs) are studied. Such assessments provide one way to understand how TTSs can address problems caused by transportation, such as accidents, emissions, and energy consumption. TTSs are services based on telematic systems which are Intelligent Transport Systems (ITS) involving the integrated use of information and communication technologies in transport. The focus is on TTSs that are relevant for road freight transport, even though the suggested methods can easily be adapted for TTSs in other areas. We characterize TTSs, e.g., in terms of their functionalities, and apply computer-based modeling for pre-deployment assessment of various TTSs (from an ex-ante perspective). By analyzing information provided by the suggested computer-based models, it is possible to make an informed decision whether to (or not to) deploy a given TTS. A review of previous studies reveals information about relevant TTSs for freight transport in areas such as driver support, administration, safety, traffic management, parking, and goods handling. A hierarchical clustering algorithm and a k-minimum spanning tree algorithm were employed to analyze synergies of TTSs. Synergies can enable identification of sets of TTSs that can lead to cost savings if deployed on a common platform (cf. Multi-Service Architectures). An analytical model inspired by the net present value concept is used to estimate quantified societal benefits of TTSs. An optimization model is formulated and solved using a branch and bound method to determine an optimal combination of TTSs taking into consideration societal benefits, costs, dependencies, and synergies. The optimization model also addresses possible system architectures for achieving multiple TTSs. Dominance rough set approach is used to assess and compare benefit areas for TTSs specific to truck parking. The benefit areas are suggested with the help of conceptual modeling, which describes functional models of a system in terms of states, transitions among states, and actions performed in states. The main scientific contributions of the thesis are in suggesting new quantitative models, extending and applying existing models in the assessments of TTSs, and obtaining results that can help decision-makers select TTSs for medium-to long-term investments. Researchers can employ and build on the proposed methods when addressing different scenarios (geographic or organizational) involving similar TTSs. By studying a range of TTSs and possible Multi-Service Architecture concepts for such TTSs, the thesis contributes to achieving convergence of TTSs in a Multi-Service Architecture environment that will improve cost efficiency, minimize redundancies, and encourage the establishment of standards in the deployment of TTSs in road freight transport. TTSs implemented in such an environment can contribute to optimizing available capacity, accuracy, speed, and efficiency of road freight transport systems.
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Pasidis, Ilias. "Urban transport externalities." Doctoral thesis, Universitat de Barcelona, 2017. http://hdl.handle.net/10803/404487.
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Chapter 2 of this dissertation estimates the joint causal effect of highway and railway Infrastructure on the suburbanization of population in European cities. Using a unique dataset of 579 European cities from 29 European countries during the period 1961-2011, I provide evidence that an additional highway ray displaces on average approximately 9 percent of the central city population to the suburbs in Europe's cities. However, Roman and Medieval cities appear to be more resilient to this process. Indeed, this existence of historical amenities in the cities of Europe appears to provide a reasonable explanation for these differences, providing some of the first empirical evidence for Brueckner et al. ( 1999)'s theory.
Chapter 3 of this dissertation tests and confirms the 'fundamental law of highway congestion' for the cities of Europe. Using different approaches, I find an elasticity of Vehicle Kilometres Travelled (VKT) with respect to highway lane km in the range of 0. 7-1. In a second stage, I estimate the effect of the increase in highway traffic on the emissions of some of the most harmful air pollutants. For nitrogen oxides, the estimated elasticity is approximately 0.10 - I.e. a ten-percent increase in highway traffic causes a one-percent increase in nitrogen oxide emissions. Sulphur dioxide also seems to increase considerably with highway traffic. Furthermore, the heterogeneous analysis shows that the increase in traffic congestion and urban air pollution is higher in cities with- out tolls - a finding that substantiates congestion pricing - and in cities without subways - a finding that corroborates rapid transit policies.
Chapter 4, in contrast, analyses the bidirectional relationship between high- way accidents and traffic congestion for highways In England. The research design is based on the daily and hourly specific mean reversion pattern of highway traffic, which can be used to define a recurrent congestion benchmark. Using this benchmark, I am able to identify the causal effect of accidents on non-recurrent traffic congestion. The results of this analysis suggest that a marginal decrease in the average speed due to an accident is about 7.8 km/h, while the journey time increases by around 27 percent when I consider the duration of this effect. Another important finding is that the effect declines by 70-75 percent after the first quarter of an hour. Finally, a back-of- the- envelope calculation suggests that an accident causes on average a 70-minute traffic delay per km for the users of that particular highway segment, while this effect Is 160 minutes in recurrently congested segments.
Chapter 5 uses geo-located data of retail rents, shop vacancies and footfall in the Netherlands to quantify shopping externalities. First, a theoretical model formalizes the existence of vacancies in the property market and establishes the relationship between shop rents and footfall, as well between vacancies and footfall. Identification is obtained using a novel research design based on spatial differences of footfall between intersecting shopping streets. The estimates imply an elasticity of rental in- come with respect to footfall of about 0.25 and about 0.1 with respect to the number of shops. The latter is substantial compared to the elasticities in the agglomeration economies literature. A shop's marginal benefit of a pedestrian passing by Is about 0.004 euros. The study also shows that footfall reduces shop vacancy rates consider-ably. Using the estimated elasticity of rental income, welfare considerations can be made taking into account new and existing shops. An average annual subsidy of about 10 percent of the rent to a new shop is welfare optimal, but when subsidies are given to existing shops, subsidies to shops that generate more footfall should be substantially higher.
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Steigleder, Mauro. "Pencil Light Transport." Thesis, University of Waterloo, 2005. http://hdl.handle.net/10012/1150.
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Global illumination is an important area of computer graphics, having direct applications in architectural visualization, lighting design and entertainment. Indirect illumination effects such as soft shadows, color bleeding, caustics and glossy reflections provide essential visual information about the interaction of different regions of the environment. Global illumination is a research area that deals with these illumination effects. Interactivity is also a desirable feature for many computer graphics applications, especially with unrestricted manipulation of the environment and lighting conditions. However, the design of methods that can handle both unrestricted interactivity and global illumination effects on environments of reasonable complexity is still an open challenge. We present a new formulation of the light transport equation, called pencil light transport, that makes progress towards this goal by exploiting graphics hardware rendering features. The proposed method performs the transport of radiance over a scene using sets of pencils. A pencil object consists of a center of projection and some associated directional data. We show that performing the radiance transport using pencils is suitable for implementation on current graphics hardware. The new algorithm exploits optimized operations available in the graphics hardware architecture, such as pinhole camera rendering of opaque triangles and texture mapping. We show how the light transport equation can be reformulated as a sequence of light transports between pencils and define a new light transport operator, called the pencil light transport operator, that is used to transfer radiance between sets of pencils.
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Kim, Wonjung Ph D. Massachusetts Institute of Technology. "Optimal transport strategies." Thesis, Massachusetts Institute of Technology, 2013. http://hdl.handle.net/1721.1/79309.
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Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2013.Cataloged from PDF version of thesis.
Includes bibliographical references (p. 103-112).
It is generally presupposed that the shapes and mechanisms encountered in nature have evolved in such a way as to maximize the robustness of a species. However, most such optimization problems arising in biology are sufficiently complex that it is neither clear what is being optimized, nor what are the relevant constraints. We here consider a number of natural fluid transport systems that may be framed in terms of constrained optimization problems. We first examine natural drinking strategies. We classify the drinking strategies of a broad range of creatures according to the principal forces involved, and present physical pictures for each style. Simple scaling arguments are developed and tested against existing data. While suction is the most common drinking strategy, various alternative styles have evolved among creatures whose morphological, physiological and environmental constraints preclude it. Many small creatures rely on relatively subtle capillary effects for fluid uptake. Particular attention is given to nectar drinking strategies. Nectar drinkers must feed quickly and efficiently due to the threat of predation. While the sweetest nectar offers the greatest energetic rewards, the sharp increase of viscosity with sugar concentration makes it the most difficult to transport. An optimal sugar concentration is thus expected for which the energy intake rate is maximized. An extensive data set indicates that the sugar concentration that optimizes energy transport depends exclusively on the drinking technique employed. We identify three nectar drinking techniques: active suction, capillary suction, and viscous dipping and rationalize the reported optimal concentrations for each through consideration of the appropriate constrained optimization problem. Blood flow in vertebrates and phloem flow in plants are known to be optimized for efficient transport of oxygen and sugar, respectively. Efficient transport of material is similarly advantageous in engineered transport systems such as traffic and wireless networks. We thus develop a general framework for determining the concentration that maximizes the material flow in a number of transport systems.
by Wonjung Kim.
Ph.D.
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V, Parzhytskaya D., and Goncharova A. D. "Mathemetics and transport." Thesis, National Aviation University, 2021. https://er.nau.edu.ua/handle/NAU/50703.
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1. GasnIkov A. V., Klenov S. L., NurmInskIy E. A., Holodov Ya. A., Shamray N. B. Vvedennya v matematichne modelyuvannya transportnih potokIv. - M.: MTsNMO, 2013.
2. VuchIka V. R. Transport v mIstah, zruchnih dlya zhittya. - M .: TeritorIya maybutnogo, 2011. - [OrigInal: Vuchic V. R. Transportation for Livable Cities, 1999].Transport is sometimes called the circulatory system of a country’s economy. Railway, automobile, sea, river, air - these are just general names for a well-known list of modes of transport. Huge numbers of people and essential goods move on land, in the air, and on water. All this is important to do on time and with minimal cost.
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Syed, Asif Ahmed. "Water Transport Terminal." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/31738.
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This thesis is an attempt in the exploration of an architectural idea of breaking away from a conventional column beam structure.
This idea led to a geometrical form which would be most stable, supported by itself, and also helps mitigate the lateral forces of wind and water in which it would stand. The conical form and scale achieved in the proposal would also help create a landmark to the cityâ s growing skyline.
It also acts as the point of threshold between land and water, providing an opportunity to sense water in a variety of ways.Master of Architecture
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Legrand, Dupont Bénédicte. "L'opération de transport." Lille 2, 2010. http://www.theses.fr/2010LIL20015.
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Réceptacle des multiples influences économiques, politiques et environnementales, le transport des marchandises reflète une réalité complexe. En effet, appréhendée à la lumière des nouveaux enjeux, la configuration d'un déplacement de marchandise s'en est trouvée altérée tant d'un point de vue technique que juridique. A ce titre, son approche mérite d'être renouvelée. Le renouvellement de l'approche se traduit par une nouvelle analyse du déplacement au coeur d'une opération complexe. Dès lors, la notion d'opération de transport s'est naturellement imposée comme la réponse aux nombreux bouleversements qui ont affecté et complexifié l'acheminement des marchandises. Parce qu'interdépendance technique et juridique caractérisent aujourd'hui la relation de transport devenue plurale, complexe de contrats et contrat complexe expriment cette réalité ainsi que les conséquences qui y sont attachéesThe crucible for multifarious economic, political and envirenmental influences, goods transportation reflects an intricate reality. Because it is now grasped by having an insight into new issues, the shape of goods movements has been modified from a technical point of view as well as a legal one. On this account only, its apprehension warrants a new approach. The reneval brought about by the latter is conveyed through a novel analysis of the movement taking place within a complex transport operation. Consequently, the notion of an operational level agreement naturally took hold as a response to the many disruptions which impacted and complexified the carriage of goods. Since juridicial and technical interdependence today characterises transport relationships that have become plurial, complexes of contracts and complex contracts give expression to this reality as well as to the consequences pertaining to it
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Rolland, Guy Garraud Pierre. "Filouterie de transport." Lyon : Université Lyon3, 2006. http://thesesbrain.univ-lyon3.fr/sdx/theses/lyon3/1990/rolland_g.
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Walschaers, Mattia [Verfasser], Andreas [Akademischer Betreuer] Buchleitner, and Mark [Akademischer Betreuer] Fannes. "Efficient quantum transport." Freiburg : Universität, 2016. http://d-nb.info/1122647247/34.
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Shin, Ghi Ryang. "Quantum transport theory." Diss., The University of Arizona, 1993. http://hdl.handle.net/10150/186508.
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Within the framework of the quantum transport theory based on the Wigner transform of the density matrix I study first in non-relativistic and subsequently in relativistic formulation a number of applications. I also develop further the recently proposed relativistic theory: the classical limit is carefully derived and the integral equations of the relativistic Wigner function derived explicitly. I show how it is possible to obtain the Schwinger like particle production rate from relativistic quantum transport equations. Noteworthy numerical results address the shape of the relativistic Wigner function of a given quantum state. Other numerical studies are primarily oriented towards the time evolution of the Wigner function--I can presently solve only the nonrelativistic case in which there is no mixing between particle production and flow phenomena: I consider numerically the fate of the muon after muon catalyzed fusion.
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Heaton, Luke Latham Moorhouse. "Biological transport networks." Thesis, University of Oxford, 2012. https://ora.ox.ac.uk/objects/uuid:48cf4d64-c051-463c-b9f8-ff50f1a4c2c7.
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Cord-forming fungi form extensive networks that continuously adapt to maintain an efficient transport system, and we can photograph their growth, digitize the network structure, and measure the movement of radio-tracers. Mycelial networks are more accessible than the transport networks of other multicellular organisms, but there are many open questions concerning the coordination of growth and transport within fungal networks. As osmotically driven water uptake is often distal from the growing margin, and aqueous fluids are effectively incompressible, we propose that growth induces mass flows across the mycelium, towards the growing regions. We imaged the temporal evolution of networks formed by Phanerochaete velutina, and at each stage calculated the unique set of currents that account for the observed changes in cord volume, while minimizing the work required to overcome viscous drag. Predicted speeds were in reasonable agreement with experimental data, and cords that were predicted to carry large currents were significantly more likely to increase in size than cords with small currents. We have also developed an efficient method for calculating the exact quantity of resource in each part of an arbitrary network, where the resource is lost or delivered out of the network at a given rate, while being subject to advection and diffusion. This method enabled us to model the spatial distribution of resource that emerges as a fungal network grows over time, and we found good empirical agreement between our model and experimental data gathered using radio-labelled tracers. Our results suggest that in well insulated fungal networks, growth-induced mass flow is sufficient to account for long distance transport. We conclude that active transport mechanisms may only be required at the very end of the transport pathway, near the growing tips. We also developed a simple model of glucose delivery through vascular networks, which indicates that increasing the number of blood vessels in a region can actually decrease the total rate of glucose delivery.
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Ji, Zhi Ping. "Transport combiné ou transport routier ? Etude des facteurs de choix entre deux systèmes de transport intérieur de fret." Phd thesis, Ecole Nationale des Ponts et Chaussées, 1994. http://tel.archives-ouvertes.fr/tel-00529459.
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Le but de cette thèse est de décrire la problématique de la concurrence entre le transport combiné et le transport routier, par une analyse quantitative des facteurs influant le choix du transport combiné intérieur. Cette analyse s'appuie sur des outils économétriques du choix du mode de transport qui reposent sur la théorie de la maximisation de l'utilité du consommateur. Une double démarche de la modélisation a été conduite afin de trouver les facteurs sensibles à l'égard du transport combiné : d'une part, la modélisation agrégée du partage modal à l'aide des données recensées sur un échantillon de 44 axes principaux du transport combiné intérieur, et d'autre part, la modélisation désagrégée à l'aide des données tirées de l'enquête auprès des chargeurs de l'INRETS. Les résultats obtenus au cours de ce travail sont plutôt encourageants. Notre étude confirme que les facteurs tels que le prix et la distance ont une forte influence sur le choix du transport combiné. En plus, d'autres facteurs tels que les plages horaires de départ des trains, les différentes catégories de chargeurs et la valeur au kilo de l'envoi se révèlent également sensibles vis-à-vis du choix du transport combiné. La méthode utilisée permet de prévoir l'influence de la concurrence sur le marché de transport de fret et peut s'avérer aussi un outil d'analyse dans le but d'éclairer la politique du développement du transport combiné.
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Ji, Zhi Ping. "Transport combiné ou transport routier? : étude des facteurs de choix entre deux systèmes de transport intérieur de fret." Marne-la-vallée, ENPC, 1994. http://www.theses.fr/1994ENPC9423.
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Le but de cette thèse est de décrire la problématique de la concurrence entre le transport combiné et le transport routier, par une analyse quantitative des facteurs influant le choix du transport combiné intérieur. Cette analyse s'appuie sur des outils économétriques du choix du mode de transport qui reposent sur la théorie de la maximisation de l'utilité du consommateur. Une double démarche de la modélisation a été conduite afin de trouver les facteurs sensibles a l'égard du transport combiné; d'une part, la modélisation agrégée du partage modal à l'aide des données recensées sur un échantillon de 44 axes principaux du transport combiné intérieur, et d'autre part, la modélisation désagrégée a l'aide des données tirées de l'enquête auprès des chargeurs de l'INRETS. Les résultats obtenus au cours de ce travail sont plutôt encourageants. Notre étude confirme que les facteurs tels que le prix et la distance ont une forte influence sur le choix du transport combiné. En plus, d'autres facteurs tels que les plages horaires de départ des trains, les différentes catégories de chargeurs et la valeur au kilo de l'envoi se révèlent également sensibles vis-à-vis du choix du transport combiné. La méthode utilisée permet de prévoir l'influence de la concurrence sur le marché de transport de fret et peut s'avérer aussi un outil d'analyse dans le but d'éclairer la politique du développement du transport combiné
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Huisinga, Torsten. "Internet Data Transport - From the Perspective of Discrete Mass Transport Modeling." Gerhard-Mercator-Universitaet Duisburg, 2006. http://www.ub.uni-duisburg.de/ETD-db/theses/available/duett-04212006-081607/.
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In recent years a new class of one-dimensional cellular automata (CA) models has attracted much attention. These so-called mass transport models can be characterized as nonequilibrium stochastic processes. In the presented thesis a new model of this class, the Asymmetric Multi Occupation Process (AMOP) is considered. This CA model was first introduced with open boundary conditions to simulate Internet data transport. It is defined on a one-dimensional lattice equipped with buffers of finite size that can be occupied by at most B particles. The local dynamics are implemented by the totally asymmetric shift of discrete mass variables respectively particles under consideration of hard-core repulsion and parallel dynamics. In the first part of this work the AMOP with periodic boundary conditions is investigated by means of numerical as well as analytical considerations. Regarding deterministic model dynamics the influence of finite buffer and system sizes onto the fundamental diagram (FD), i.e., flow-density relation is analyzed. Furthermore, for stochastic movement the FDs obtained by numerical simulations are compared with analytical results derived by Mean-Field (MF) approaches and a 2-cluster approximation. In the second part the AMOP with open boundary conditions is investigated in the context of boundary induced phase transitions. In case of deterministic bulk dynamics an analytical exact representation of the system inflow as well as the outflow is presented in dependence of the buffer size. As a result the deterministic phase diagram derived by numerical simulations could be verified by analytical considerations. Regarding stochastic particle movement the phase diagram is obtained by Monte Carlo simulations. In both cases it is shown that the jammed phase is strongly enlarged for increasing buffer sizes. Finally, in the third part of this thesis the influence of interacting boundaries on the model dynamics is analyzed. Therefore, a new fall back inflow strategy is introduced in order to stabilize high flow states and thus prevent the system from a complete jamming. Precisely, the inflow is determined by the state of the last site of the system. As a result the phase diagrams of the deterministic and the stochastic model obtained by means of numerical simulations are presented. Two new phases could be identified a free-flow as well as a jammed phase both characterized by a striped microscopic pattern. Especially in the arising striped jammed regime system flow and mean velocity are drastically enlarged compared to generic inflow strategies. Here, the fall back strategy is capable to prevent the system from a complete jamming. Thus, the introduced inflow procedure represents an effective strategy for establishing reliable connections.
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Schmidt, Frank Dr Ing. "Transport und Abscheidung submikroner Partikel - Transport and deposition of submicron particles." Gerhard-Mercator-Universitaet Duisburg, 2001. http://www.ub.uni-duisburg.de/ETD-db/theses/available/duett-08022001-085456/.
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In this study transport and deposition of submicron particles in turbulent and laminar flows is investigated theoretically. Beginning with the modelling of transport processes in pipe flows, transport onto surfaces and in industrial gas cleaning systems has been calculated. Deposition of particles takes place due to convective diffusion, sedimentation,thermophoresis and impaction. Although different geometries have been investigated a characteristical deposition behaviour has been found with a deposition minimum for submicron particles with diameters larger than 0.1 mm. Transport of these particles often depends on thermo- or electrophoresis.
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Wang, Lei. "A Performance Evaluation of Dynamic Transport Switching for Multi-Transport Devices." Diss., CLICK HERE for online access, 2006. http://contentdm.lib.byu.edu/ETD/image/etd1603.pdf.
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Lewis, Dale B. (Dale Brian). "Freight mode choice : air transport versus ocean transport in the 1990s." Thesis, Massachusetts Institute of Technology, 1995. http://hdl.handle.net/1721.1/11828.
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Norscini, Claudia. "Coarse graining of plasma turbulent transport to recover thermodynamical transport laws." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amslaurea.unibo.it/4028/.
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Rassadi, Roozbeh. "The effect of stress on nuclear protein transport : classical nuclear protein transport versus the nuclear transport of heat shock proteins." Thesis, McGill University, 1999. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=33476.
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The stress response is conserved among eukaryotes and affects different cellular functions including protein transport. Here, we have investigated the effect of different types of stress on classical nuclear protein import as well as nuclear import of Ssa4p family of heat shock proteins in Saccharomyces cerevisiae.Under normal conditions, Aequorea victoria green fluorescent protein (GFP), carrying a classical nuclear localization sequence (cNLS-GFP) is nuclear. However, cNLS-GFP equilibrates throughout the cell upon exposure to heat, ethanol, H2O2 or starvation. Redistribution of the small GTPase Gsp1p, a soluble nuclear transport factor, correlates with cNLS-GFP equilibration. This suggests that a collapse of the Gsp1p gradient underlies the inhibition of classical nuclear protein import. In contrast to cNLS-GFP, the cytoplasmic heat shock protein Ssa4p accumulates in nuclei when classical nuclear import is inhibited. The N-terminal 236 amino acid residues of Ssa4p are sufficient for nuclear localization of Ssa4p-GFP upon heat and ethanol stress. The nuclear localization of Ssa4p(1--236)-GFP requires components of Gsp1-GTPase system, but is independent of Srp1p, the cNLS receptor.
Ssa4p(16--642)-GFP accumulates in nuclei of starving cells, mediated by a hydrophobic stretch of amino acid residues in its N-terminal domain. This nuclear localization is reversible upon addition of fresh medium and its export is sensitive to oxidants and temperature-dependent.
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Guerrero, Miguel Arango, and Pedro Shiguihara Juárez. "A Novel Dataset for the Transport Sector in a Province of Peru." Smart Innovation, Systems and Technologies, 2021. http://hdl.handle.net/10757/653801.
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El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.Problems related to public transport and private transport in Peru are persistent. New proposals to solve them arise, currently the world of data analysis is starting in Peru, there are not many open datasets useful that allow proposing solutions in each environment. In this paper, we will collect relevant data of the transport located in a province of Peru with more than 1000 users involved, restricted by a delimited geographic area and with 2 years of operations and more than 3000 transport services tracked. In this way, we highlight the importance of the data, the possible potential uses within the transport, and a case of use of the collected dataset.
Revisión por pares
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Neff, Stephan. "Heavy-ion beam transport in plasma channels transport properties and channel stability /." [S.l. : s.n.], 2005. http://elib.tu-darmstadt.de/diss/000561.
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Scholak, Torsten [Verfasser], and Andreas [Akademischer Betreuer] Buchleitner. "Transport and coherence in disordered networks = Transport und Kohärenz in ungeordneten Netzwerken." Freiburg : Universität, 2011. http://d-nb.info/1123462208/34.
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Garabedian, Stephen P. "Large-scale dispersive transport in aquifers : field experiments and reactive transport theory." Thesis, Massachusetts Institute of Technology, 1987. http://hdl.handle.net/1721.1/14645.
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Jönsson, Linda. "Transport av högdräktiga nötkreatur : Hur påverkas ko och fullvuxet foster av transport." Thesis, Linnéuniversitetet, Institutionen för biologi och miljö (BOM), 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:lnu:diva-53370.
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The aim of the project is to obtain a deeper understanding of how cattle in late pregnancy are affected by transportation and calving during transport or in unsuitable lairage systems at the slaughterhouse. Also, the effect on the calf, whether it is in the womb or after calving, will be investigated. The cattle are in late pregnancy when 90% of the gestation period has passed and during that period they should not be transported. However, veterinarians at the slaughterhouses in Sweden sometimes find fully grown calves in the womb of cattle. Between 1 January 2013 and 1 March 2016 veterinarians informed the county administrative boards about 353 fully grown calves in cattle, which should not been allowed to be transported. Most of the calves probably would have survived if they were born under normal circumstances in a peaceful and safe environment. Cattle in late pregnancy are exposed to great physical and mental stress during transportation, which leads to poor animal welfare. The stress they experience can lead to an abortion of the fetus. If calving occurs during transportation or at the slaughterhouse, there is a risk for both cow and calf to obtain serious physical and mental damage.Syftet med examensarbetet är att erhålla en djupare förståelse för hur högdräktiga nötkreatur påverkas av transport och eventuell kalvning i olämpliga system samt hur kalven påverkas av situationen, vare sig det är i livmodern eller efter kalvning. Nötkreaturen räknas som högdräktiga då 90 % av dräktigheten har passerat, vilket inträffar då det är 28 dagar kvar till beräknad kalvning. Det förekommer dock att Livsmedelsverkets veterinärer ibland finner fullgångna foster i moderdjur som inkommer till Sveriges slakterier. Mellan den 1 januari 2013 och 1 mars 2016 har veterinärerna underrättat länsstyrelserna om 353 möjliga fall av fullvuxna kalvar som troligtvis hade klarat sig om de hade förlösts under normala omständigheter i en lugn och trygg miljö. Högdräktiga nötkreatur utsätts för stora fysiska påfrestningar och omfattande stress i samband med transport vilket leder till dålig djurvälfärd. Hon är stor, tung och klumpig vilket gör att hon tar mer plats i transporten och har problem med att hålla balansen. Stressen som kon utsätts för kan bidra till att kon aborterar fostret. Om kalvning sker ombord på transportfordonet eller på slakteriet riskerar både ko och kalv att utsättas för allvarliga fysiska och psykiska skador. Kalven kan utsättas för skador då transporten inte är anpassad till kalvar och det finns andra nötkreatur ombord. Kalven kan även utsättas för värmestress samt köld och infektioner som kan leda till död.
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Pasichnyk, Inna, and Інна Олександрівна Пасічник. "Integration of the domestic transport system into European and international transport systems." Thesis, National Aviation University, 2021. https://er.nau.edu.ua/handle/NAU/50590.
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1. Natsionalna Transportna Stratehiia Ukrainy Do 2030 roku [in ukr.]. – Access mode: http://publications.chamber.ua/Infrastructure/UDD/ National_Transport_Strategy_2030.pdf
2. Spivrobitnytstvo U Sferi Transportu - 2020: Predstavnytstvo Ukrainy Pry YeS [in ukr.]. – Access mode: https://ukraine-eu.mfa.gov.ua/posolstvo/galuzeve-spivrobitnictvo/transport
3. Danilieva Yu. Intehratsiia Ukrainy Do Rynku Transportnykh Posluh Krain YeS [in ukr]/ Yu. Danilieva. // Visnyk Skhidnoukrainskoho NU Im. V. Dalia. – 2017. – №3. – С. 59–63.
Supervisor – PhD in Economics, Associate Professor Klymenko V.V.Today, the problem of integration of Ukraine's transport system into the European Union has been widely discussed. It is a subject of the National Transport Strategy of Ukraine up to 2030. The transport sector of Ukraine is a significant and important segment for the country's economy, because the efficient and coordinated operation of the entire transport system is a driving force for the overall development of the country. The development of integration processes and the growth of competition in the market of transport services requires new approaches to the development of transport relations, the creation of new technologies and improving the quality of services.
Сьогодні проблема інтеграції транспортної системи України до Європейського Союзу широко обговорюється. Це предмет Національної транспортної стратегії України до 2030 року. Транспортний сектор України є важливим та важливим сегментом для економіки країни, оскільки ефективна та скоординована робота всієї транспортної системи є рушійною силою загального розвитку країни. Розвиток інтеграційних процесів та зростання конкуренції на ринку транспортних послуг вимагає нових підходів до розвитку транспортних відносин, створення нових технологій та підвищення якості послуг.
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DENIS, MARIE-HELENE. "Absorption cuticulaire, transport membranaire et transport à longue distance de l'herbicide glyphosate." Poitiers, 1993. http://www.theses.fr/1993POIT2298.
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Le glyphosate (n-phosphonomethylglycine) est un herbicide tres efficace commercialise sous le nom de roundup. Son efficacite est liee en partie au fait qu'il est bien distribue dans toute la plante a partir des feuilles traitees. Notre travail visait a mieux comprendre les differentes etapes du transport permettant cette distribution. En premier lieu, nous avons etudie l'effet des surfactants mon 0818 et mon 8109 et des sels inorganiques sur la penetration de l'herbicide. Les surfactants stimulent l'absorption du pesticide chez les trois plantes etudiees (vicia faba; brassica napus et elymus repens) sans influencer la translocation. Les melanges surfactants/sels d'ammonium ameliorent parfois l'efficacite du surfactant en augmentant la translocation. Dans un second temps, nous avons focalise notre attention sur l'effet des cations divalents. La chelation des cations diminue a la fois l'absorption cuticulaire et l'absorption membranaire du glyphosate, mais les cations a fortes concentrations n'augmentent que la penetration cuticulaire. L'absorption phloemienne du pesticide est inhibee specifiquement par l'egta, chelateur des ions ca, mais les chelateurs n'affectent pas la vitesse de la translocation de l'herbicide. Le calcium stimule transitoirement (10 min) l'absorption du glyphosate dans les protoplastes foliaires et inversement, le glyphosate stimule de la meme facon l'absorption du ca. L'effet stimulateur du glyphosate sur l'influx de ca implique vraisemblablement des canaux calciques, puisqu'il est partiellement bloque par le verapamil. Enfin, la derniere partie du travail demontre qu'a faible concentration, l'absorption du glyphosate peut etre catalysee par un transporteur de phosphate. En effet, l'acide phosphonoformique (pfa) inhibe competitivement l'absorption du phosphate, mais aussi celle du glyphosate. Le glyphosate, dont l'absorption presente un caractere saturable a faible concentration, peut proteger partiellement le transporteur de phosphate de l'inhibition induite par le pfa
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Rinn, Bernd. "Transport and aging in glassy systems Transport und Altern in glasartigen Systemen /." [S.l. : s.n.], 2002. http://www.bsz-bw.de/cgi-bin/xvms.cgi?SWB9683811.
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Donnel, Peter. "Impurity transport in tokamak plasmas : gyrokinetic study of neoclassical and turbulent transport." Thesis, Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0485/document.
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La compréhension du transport d’impuretés dans les tokamaks est cruciale. En effet, les noyaux lourds ne sont que partiellement ionisés dans le cœur du plasma, ils peuvent alors fortement rayonner et entraîner une diminution importante de la qualité du plasma. Une accumulation des impuretés au cœur du plasma est souvent observée au sein des tokamaks. Cette accumulation est souvent attribuée à la physique néoclassique mais le transport turbulent pourrait bien dominer dans la zone de gradient dans ITER. Jusqu’à récemment, le calcul des flux néoclassique et turbulent étaient réalisés de façon distincte, supposant implicitement que les deux canaux de transport sont indépendants. On peut se demander si cette hypothèse est valide.En effet, des simulations obtenues avec le code gyrocinétique GYSELA ont montré l’existence d’une synergie entre transports néoclassique et turbulent dans le cas des impuretés et un mécanisme permettant sa compréhension a été trouvé.La turbulence peut générer des asymétries poloidales. Un travail analytique permet de prédire le niveau et la structure de la partie axisymétrique du potentiel électrique. Deux mécanismes sont à l’origine des asymétries poloidales du potentiel électrique: la compressibilité du flot et le ballonnement de la turbulence.Une nouvelle prédiction du flux d’impureté néoclassique en présence d’asymétries poloidales et d’anisotropie de la pression a été réalisée. Un bon accord a été trouvé entre la nouvelle prédiction et une simulation réalisée avec GYSELA pour laquelle la turbulence est à l’origine des asymétries poloidales et de l’anisotropie de la pressionImpurity transport is an issue of utmost importance for tokamaks. Indeed high-Z materials are only partially ionized in the plasma core, so that they can lead to prohibitive radiative losses even at low concentrations, and impact dramatically plasma performance and stability. On-axis accumulation of tungsten has been widely observed in tokamaks.While the very core impurity peaking is generally attributed to neoclassical effects, turbulent transport could well dominate in the gradient region at ITER relevant collisionality. Up to recently, first principles simulations of corresponding fluxes were performed with different dedicated codes, implicitly assuming that both transport channels are separable and therefore additive. The validity of this assumption is questionned. Simulations obtained with the gyrokinetic code GYSELA have shown clear evidences of a neoclassical-turbulence synergy for impurity transport and allowed the identification of a mechanism that underly this synergy.An analytical work allows to compute the level and the structure of the axisymmetric part of the electric potential knowing the turbulence intensity. Two mechanisms are found for the generation of poloidal asymmetries of the electric potential: flow compressibility and the ballooning of the turbulence. A new prediction for the neoclassical impurity flux in presence of large poloidal asymmetries and pressure anisotropies has been derived. A fair agreement has been found between the new theoretical prediction for neoclassical impurity flux and the results of a GYSELA simulation displaying large poloidal asymmetries and pressure anisotropies induced by the presence of turbulence
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Donnel, Peter. "Impurity transport in tokamak plasmas : gyrokinetic study of neoclassical and turbulent transport." Electronic Thesis or Diss., Aix-Marseille, 2018. http://www.theses.fr/2018AIXM0485.
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La compréhension du transport d’impuretés dans les tokamaks est cruciale. En effet, les noyaux lourds ne sont que partiellement ionisés dans le cœur du plasma, ils peuvent alors fortement rayonner et entraîner une diminution importante de la qualité du plasma. Une accumulation des impuretés au cœur du plasma est souvent observée au sein des tokamaks. Cette accumulation est souvent attribuée à la physique néoclassique mais le transport turbulent pourrait bien dominer dans la zone de gradient dans ITER. Jusqu’à récemment, le calcul des flux néoclassique et turbulent étaient réalisés de façon distincte, supposant implicitement que les deux canaux de transport sont indépendants. On peut se demander si cette hypothèse est valide.En effet, des simulations obtenues avec le code gyrocinétique GYSELA ont montré l’existence d’une synergie entre transports néoclassique et turbulent dans le cas des impuretés et un mécanisme permettant sa compréhension a été trouvé.La turbulence peut générer des asymétries poloidales. Un travail analytique permet de prédire le niveau et la structure de la partie axisymétrique du potentiel électrique. Deux mécanismes sont à l’origine des asymétries poloidales du potentiel électrique: la compressibilité du flot et le ballonnement de la turbulence.Une nouvelle prédiction du flux d’impureté néoclassique en présence d’asymétries poloidales et d’anisotropie de la pression a été réalisée. Un bon accord a été trouvé entre la nouvelle prédiction et une simulation réalisée avec GYSELA pour laquelle la turbulence est à l’origine des asymétries poloidales et de l’anisotropie de la pressionImpurity transport is an issue of utmost importance for tokamaks. Indeed high-Z materials are only partially ionized in the plasma core, so that they can lead to prohibitive radiative losses even at low concentrations, and impact dramatically plasma performance and stability. On-axis accumulation of tungsten has been widely observed in tokamaks.While the very core impurity peaking is generally attributed to neoclassical effects, turbulent transport could well dominate in the gradient region at ITER relevant collisionality. Up to recently, first principles simulations of corresponding fluxes were performed with different dedicated codes, implicitly assuming that both transport channels are separable and therefore additive. The validity of this assumption is questionned. Simulations obtained with the gyrokinetic code GYSELA have shown clear evidences of a neoclassical-turbulence synergy for impurity transport and allowed the identification of a mechanism that underly this synergy.An analytical work allows to compute the level and the structure of the axisymmetric part of the electric potential knowing the turbulence intensity. Two mechanisms are found for the generation of poloidal asymmetries of the electric potential: flow compressibility and the ballooning of the turbulence. A new prediction for the neoclassical impurity flux in presence of large poloidal asymmetries and pressure anisotropies has been derived. A fair agreement has been found between the new theoretical prediction for neoclassical impurity flux and the results of a GYSELA simulation displaying large poloidal asymmetries and pressure anisotropies induced by the presence of turbulence
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Laube, Felix B. "Optimising urban passenger transport: Developing a least-cost model based on international comparisons of urban transport costs, transport patterns, land use, infrastructure environment and best practice in public transport." Thesis, Laube, Felix B. (1998) Optimising urban passenger transport: Developing a least-cost model based on international comparisons of urban transport costs, transport patterns, land use, infrastructure environment and best practice in public transport. PhD thesis, Murdoch University, 1998. https://researchrepository.murdoch.edu.au/id/eprint/51498/.
Full textAbstract:
Public policy debate today in the field of urban transport tends to be strongly divided. On the one hand there are those who see private motorised mobility or automobile dependence as a logical expression of growing wealth and as such, virtually unavoidable; the city must be adapted to almost open-ended car use. On the other hand, there are those who see private passenger transport as a major problem in cities for a whole host of reasons; car use should be kept within limits imposed by the capacity of the urban system to deliver livability and ecological integrity. Several issues are prominent in this debate such as what primarily influences a city's transport system - physical characteristics of the city or the economics of transport systems. The relative economic merits of different transport modes are also hotly contested. There are claims that non-automobile modes are discriminated against in the market place by inequitable pricing policies which subsidise private transport, while others argue that private transport is more cost-effective and leads to economic growth and wealth creation. With respect to the role of public transport, one side tends to marginalise it, while the other claims that it has a much bigger role to play in cities. A host of data are brought to bear on both sides of the argument claiming to be authoritative, whereas in fact in most cases direct comparability remains somewhat illusive. Naturally, calls for balance between the two views can be heard which attempt to recognise the advantages and disadvantages of the different modes and to arrive at a point where a socially-optimal balance of transport modes might be struck, and where overall transport costs might be genuinely minimised in a city's economy. Unfortunately, a methodology that might be universally applied in finding such a balance and which would bring more clarity and rigour to the debate, does not appear to exist.
This thesis therefore attempts to develop such a methodology by first asking and providing answers to a series of key questions. These questions relate to transport's position in the economy, its true costs, the extent and nature of competition between different modes, critical land use-transport interactions, the interaction of transport costs with other elements of the city, how these costs can be minimised and the role of public transport in this process. By then hypothesising that in any particular city there exists an optimum modal balance which will minimise transport costs as a function of that city's physical and economic constraints, the thesis sets out to develop a model which would represent an optimal balance of transport modes in any city. Through the use of an extensive theoretical overview, combined with thorough collection and analysis of a massive amount of comparable empirical land use, transport, economic and environmental data on 46 global cities, the thesis succeeds in providing some new insights into the above questions and building the suggested model. It also contributes significantly to overcoming a major problem in this policy debate area; the lack of standardised, comparable urban data across a wide range of city types.
The research isolates what appear to be the key underlying factors which determine the characteristics of the transport system and its overall costs. These factors are primarily physical in nature; by contrast, the key economic factors, such as the cost of driving a car, the cost of using or operating public transport and the gross regional product per capita (or city wealth), do not bear significant relationships with modal split. Through a detailed statistical evaluation of all data collected in this study and a step-by-step model building process, the key factors behind the development of a least-cost transport curve are identified. This curve shows what percentage of total motorised passenger kilometres are required on public transport in order to minimise overall passenger transport costs in any city. These costs are expressed as a percentage of a metropolitan region's gross regional product per capita. Using the results of the statistical analysis, it was found that an effective least-cost model could be developed based on the relationships between urban density and private and public transport use, and thus mode split. In order to translate private and public transport use into cost, the relationships between car ownership and car use, as well as between public transport supply and use were then integrated into the model equation.
This model, despite its present prototype form, yields some potentially significant policy insights. These include:
•the fact that all cities in the study appear to benefit economically from a greater role for public transport; all cities appear to be underprovided with public transport service and thus public transport is underused.
•the critical nature of the relative speed between public and private transport. This has direct implications for their competitive position and thus points to the need for appropriate investment in faster public transport or disinvestment in private transport infrastructure which will give public transport a speed advantage;
•the strong influence of higher urban density in improving public transport use and minimising overall transport costs, revealing the importance of reurbanisation programmes in cities. Low density cities are confirmed as being highest in overall transport costs which is not compensated for by higher levels of income and wealth. This has implications for their global competitiveness.
•the potential of lower private transport costs to negatively affect public transport share, thus offsetting the former's cost savings through increased external costs.
•the importance of internal economic efficiency in public transport systems in contributing to their role in the urban transport system, but not at the expense of service quality.
This least-cost model appears therefore to be worthy of further development and refinement as suggested in the thesis. If this can be done it would provide a very useful and wide-ranging policy tool which could be used to:
•find what modal split between public and private transport is required to minimise overall urban passenger transport costs;
•establish what kind of policies in urban planning, transport planning, infrastructure planning and the setting of transport costs might be required for a city to head towards this more satisfactory position;
•test a range of theoretical changes in various factors to see what happens to the least-cost mode split point (eg increased investment in public or private transport infrastructure (rail or freeways), changes in density, pricing policies or changes in cost structures, for example in the energy sector).
•formulate strategic policy directions and to monitor progress and adequacy of applied policies over time.
In terms of the greater role for public transport suggested by the modelling work, the thesis explores ways of optimising the overall performance of urban passenger transport through improved public transport delivery. This work suggests that it is very important to distinguish between the commercial and social optimum in public transport and that only at the social optimum does public transport reach its full potential in a city's economic well-being. This mostly means running public transport systems with an operating result which is not as good as when public transport is commercially optimised. And in operational terms, better exploitation of public transport's potential would appear possible through the use of a coordinated and integrated public transport which employs: (a) time-pulse transfer networks; (b) pulsed, supply-based scheduling; (c) bulk, prepurchase oriented system-wide fare systems; (d) regional cooperation.
Overall, the thesis points to a host of possible future research endeavours and policy applications which have the potential to improve the quality of urban transport decision-making and outcomes.