Le tétrachloroéthène (PCE) et les éthènes chlorés qui lui sont apparentés ont été abondamment utilisés pour plusieurs applications en industrie dès le début du 20e siècle. Ils sont cependant comptés parmi les polluants les plus communs des sols et de l’eau et beaucoup d’efforts sont déployés afin de les éliminer. Nous croyons que la conversion des éthènes chlorés en éthènes par des microorganismes est une solution prometteuse. Le premier aspect du projet visait donc à établir les conditions pour lesquelles un consortium enrichi en Dehalococcoides ethenogenes permettrait la conversion complète de PCE en éthène. Les expériences réalisées nous ont permis de souligner le rôle de l’acide lactique ajouté aux cultures comme source de carbone et source indirecte d’électrons pour la déhalorespiration. Nous avons également pu établir l’effet de la concentration initiale de biomasse dans les cultures sur le profil de déhalogénation du PCE. Le deuxième aspect du projet visait à développer un protocole d’encapsulation du consortium dans une matrice polymérique afin de profiter des nombreux avantages potentiels de l’encapsulation. Nous avons testé trois montages d’encapsulation différents : atomisation avec jet d’air, atomisation avec vibrations ultrasoniques et « drop-wise ». Le dernier montage prévoyait l’encapsulation des cultures dans des billes d’alginate enrobées de chitosane gélifié par du lignosulfonate. C’est le seul montage qui nous a permis d’encapsuler le consortium de façon efficace sans effet significatifs négatifs sur son activité de déchlorination. Aussi, la comparaison des profils de déhalogénation du PCE de cellules encapsulées et cellules libres a montré une plus faible accumulation de TCE, 1,2-DCE et VC dans les échantillons de cellules encapsulée et, par conséquent, une conversion plus rapide et plus complète du PCE en éthène. Finalement, nous avons observé une tendance favorable à l’idée que les microorganismes encapsulés bénéficient d’un effet de protection contre de faibles concentrations d’oxygène. / Tetrachloroethylene (PCE) and other chlorinated ethenes have been used for industrial purposes since the beginnning of 20th century. However, they are now considered common pollutants of soil and water. A lot of efforts are directed toward elimination of these compounds and we believe degradation of these chlorinated ethenes by microorganisms is the best solution. The first step of this project was to establish a complete conversion of PCE to its non-toxic product ethylene using an enriched consortium of Dehalococcoides ethenogenes. Our results show the importance of lactic acid as a carbon source and indirect source of electrons in a reaction known as dehalorespiration. We have been able to establish the effect of initial biomass on the biodegradation profile of PCE. The second step of the project was to obtain a working protocol for encapsulation of the consortium in a polymeric matrix. Such immobilization procedure would then allows numerous possible advantages as shown in the literature. We tested three encapsulation setups: air atomization, ultrasonic atomization and drop-wise technique. In the last setup, we successfully encapsulated the bacterial consortium into particles made of an alginate core surrounded by a chitosan layer. Thus the drop-wise technique allowed encapsulation of the consortium without negative effects on its dechlorination activity. In addition, the dechlorination profiles of encapsulated cells showed a lower accumulation of chlorinated intermediates TCE, 1,2-DCE and VC which yield a more rapid and complete conversion of PCE to ethylene. Finally, our results support the idea that encapsulated microorganisms may benefit from a protective effect when oxygen is present in the medium.

Chlorinated solvent are volatile organic substances that can be harmful for humans and for the environment. Examples of common chlorinated solvents are perchloroethene, PCE, and trichloroethene, TCE. Chlorinated solvents appear as contaminants in soils primarily where they have been used as washing fluids in dry-cleaning facilities or as degreasers in metal industries. Chlorinated solvents are DNAPLs (dense non-aqueous phase liquids), which means that they are not easily dissolved in water and that they sink to the bottom of the aquifer. Adsorption to soils is low so chlorinated solvents are mobile in soils. Chlorinated solvents can be harmful at low concentrations. Complete degradation can only occur under specific conditions. Because of the properties of these substances, investigation and analysis methodology are extra important for determining transport and risks in a contaminated area. In this work, investigation and analysis methods for chlorinated solvents are described. Planning, fieldwork, modeling and risk analysis are described. Projects concerning chlorinated solvents completed by Golder Associates AB have been compiled and analysed. Based on the compilation, conclusions have been drawn and statistics have been calculated. Investigations of the relation between concentrations in different media have been made as well as investigations of the relation between degradation products at different distances from the source and at different times after release. The data from the environmental investigations have been compared with theoretical literature values and modelling results. The results show that there is a large natural variation in the data and that the differences between different areas are quite large. The results confirm the theory that the percentage of degradation products increases with distance from the source and with time from release. In addition, solvents with a higher degree of chlorination seams to appear to a greater extent in the soil and the more volatile substances seams to appear to a greater extent in the soil air. / Klorerade lösningsmedel är flyktiga klorerade organiska ämnen som kan vara skadliga för människor och miljön. Exempel på vanliga klorerade lösningsmedel är perkloreten, PCE och trikloreten, TCE. Klorerade lösningsmedel förekommer som markföroreningar främst efter användning som tvättvätska i kemtvättar och som avfettningsmedel i metallindustrin. Klorerade lösningsmedel är DNAPLs (dense non-aqueous phase liquids), det innebär att de är svårlösliga i vatten och att de sjunker och lägger sig på botten av akviferen. Fastläggningen i jorden är liten hos klorerade lösningsmedel som därmed är rörliga i marken. De är farliga redan vid små koncentrationer och fullständig nedbrytning sker endast under vissa förutsättningar. Ämnenas egenskaper gör att undersöknings- och analysmetodiken är viktig för att riktigt kunna bestämma deras utbredning och risk på ett förorenat område. I detta arbete beskrivs undersöknings- och analysmetodiken för områden förorenade med klorerade lösningsmedel. Upplägg, fältarbete, modellering och riskbedömning beskrivs. Projekt som handlar om klorerade lösningsmedel utförda av Golder Associates AB har sammanställts. Sammanställningen har analyserats och utifrån den har olika slutsatser dragits och statistik beräknats. Bland annat har samband mellan halter i olika medier samt samband mellan halter av nedbrytningsprodukter på olika avstånd från källan respektive efter olika lång tid från läckage har undersökts. Data från miljöundersökningarna har även jämförts med teoretiska litteraturvärden samt modelleringsresultat. Resultatet visar att den naturliga spridningen av data är stor samt att resultaten skiljer sig åt mellan olika områden. Resultaten bekräftar teorierna att halten nedbrytningsprodukter ökar med avståndet från källan och med tiden samt att ämnen med högre kloreringsgrad finns i större utsträckning i jorden och att flyktigare ämnen finns i större utsträckning i porluften.

Le tétrachloroéthène (PCE) et les éthènes chlorés qui lui sont apparentés ont été abondamment utilisés pour plusieurs applications en industrie dès le début du 20e siècle. Ils sont cependant comptés parmi les polluants les plus communs des sols et de l’eau et beaucoup d’efforts sont déployés afin de les éliminer. Nous croyons que la conversion des éthènes chlorés en éthènes par des microorganismes est une solution prometteuse. Le premier aspect du projet visait donc à établir les conditions pour lesquelles un consortium enrichi en Dehalococcoides ethenogenes permettrait la conversion complète de PCE en éthène. Les expériences réalisées nous ont permis de souligner le rôle de l’acide lactique ajouté aux cultures comme source de carbone et source indirecte d’électrons pour la déhalorespiration. Nous avons également pu établir l’effet de la concentration initiale de biomasse dans les cultures sur le profil de déhalogénation du PCE. Le deuxième aspect du projet visait à développer un protocole d’encapsulation du consortium dans une matrice polymérique afin de profiter des nombreux avantages potentiels de l’encapsulation. Nous avons testé trois montages d’encapsulation différents : atomisation avec jet d’air, atomisation avec vibrations ultrasoniques et « drop-wise ». Le dernier montage prévoyait l’encapsulation des cultures dans des billes d’alginate enrobées de chitosane gélifié par du lignosulfonate. C’est le seul montage qui nous a permis d’encapsuler le consortium de façon efficace sans effet significatifs négatifs sur son activité de déchlorination. Aussi, la comparaison des profils de déhalogénation du PCE de cellules encapsulées et cellules libres a montré une plus faible accumulation de TCE, 1,2-DCE et VC dans les échantillons de cellules encapsulée et, par conséquent, une conversion plus rapide et plus complète du PCE en éthène. Finalement, nous avons observé une tendance favorable à l’idée que les microorganismes encapsulés bénéficient d’un effet de protection contre de faibles concentrations d’oxygène. / Tetrachloroethylene (PCE) and other chlorinated ethenes have been used for industrial purposes since the beginnning of 20th century. However, they are now considered common pollutants of soil and water. A lot of efforts are directed toward elimination of these compounds and we believe degradation of these chlorinated ethenes by microorganisms is the best solution. The first step of this project was to establish a complete conversion of PCE to its non-toxic product ethylene using an enriched consortium of Dehalococcoides ethenogenes. Our results show the importance of lactic acid as a carbon source and indirect source of electrons in a reaction known as dehalorespiration. We have been able to establish the effect of initial biomass on the biodegradation profile of PCE. The second step of the project was to obtain a working protocol for encapsulation of the consortium in a polymeric matrix. Such immobilization procedure would then allows numerous possible advantages as shown in the literature. We tested three encapsulation setups: air atomization, ultrasonic atomization and drop-wise technique. In the last setup, we successfully encapsulated the bacterial consortium into particles made of an alginate core surrounded by a chitosan layer. Thus the drop-wise technique allowed encapsulation of the consortium without negative effects on its dechlorination activity. In addition, the dechlorination profiles of encapsulated cells showed a lower accumulation of chlorinated intermediates TCE, 1,2-DCE and VC which yield a more rapid and complete conversion of PCE to ethylene. Finally, our results support the idea that encapsulated microorganisms may benefit from a protective effect when oxygen is present in the medium.

L’emploi d’adjuvants fluidifiants est courant pour tout béton. Ceci permet d’améliorer les propriétés rhéologiques à l’état frais: la fluidité initiale et son maintien pendant les 2-3 premières heures de la vie d’un béton. La compréhension de ce mécanisme d’action est encore partielle pour les PCP (copolymères greffés). Ici, le but a été de tester l’hypothèse selon laquelle l’évolution de la quantité de PCP adsorbé par unité de surface minérale instantanée explique quantitativement l’évolution temporelle de la fluidité au cours de la période d’ouvrabilité.Sur un système inerte (calcite), nous avons confirmé que la fluidité est bien gouvernée par l’adsorption: à même adsorption surfacique, la fluidité de la pâte est quasiment identique quelle que soit la structure du PCP. Par ailleurs sur un système inerte (calcite ou ettringite), la modification de la fonction ionique du PCP fournit une solution pour améliorer la résistance de l’adsorption à la variation de la concentration en sulfates.Deux techniques ont été utilisées pour mesurer l’aire interfaciale au cours de l’hydratation d’un système réactif modèle (aluminate tricalcique, gypse, hémihydrate et calcite): l’adsorption de N2 et la relaxométrie du proton de l’eau. L’adsorption du PCP par unité de surface réelle a été calculée et corrélée à la fluidité de la pâte. La relation simple fluidité/adsorption n’est plus vérifiée ici. La présence de PCP a un impact sur l’hydratation du système et l’augmentation de l’étendue de la surface minérale associée. Les PCP vont augmenter la surface spécifique de l’ettringite qui précipite en modifiant sa morphologie. Cet effet est plus marqué quand la densité de greffage du PCP diminue. / Nowadays the use of superplasticizers admixtures becomes unavoidable for concrete. It allows enhancing the rheological properties at the fresh state: the initial flow and slump retention during the 2-3 first hours of the life of a concrete. The understanding of this mechanism is still partly elucidated for PCE (grafted copolymers). The aim of this thesis was to challenge the assumption of the evolution of the adsorbed amount of PCE per instantaneous mineral surface unit as origin of the fluidity temporal evolution during the workability period.On an inert system (calcite), we confirmed that the fluidity is mainly governed by the adsorption level. Thus for a same surface adsorption density, the fluidity of the paste is roughly similar whatever the structure of the PCE. On an inert system also (calcite or ettringite), the modification of the anionic function provides a technological way to improve the resistance of the adsorption against the variation of the sulfate ions concentration.The surface area of a reactive model system (tricalcium aluminate, gypsum, hemihydrate and calcite) has been measured by two techniques during the workability period: the N2 adsorption (BET) and the water proton relaxometry (RMN). The PCE adsorption per surface unit has been calculated and analysed in link with the fluidity of the paste. In that case, the simple relation, shown on the inert system, is not verified because the presence of PCE has also an impact on the hydration and on the extent of the surface area. Especially PCE lead to increase the surface by changing the morphology of ettringite. The specific surface area of ettringite increases when the grafting density of PCE decreases.

In situ chemical oxidation (ISCO) using permanganate has been increasingly applied to deplete mass from dense nonaqueous-phase liquid (DNAPL) source zones. However, uncertainty in the performance of ISCO on DNAPL contaminants is partially attributable to a limited understanding of interactions between the oxidant, subsurface hydrology, and DNAPL mass transfer, resulting in failure to optimize ISCO applications. To investigate these interactions, a factorial design experiment was conducted using one-dimensional flow through tube reactors to determine how groundwater velocity, permanganate concentration, and DNAPL type affected DNAPL mass depletion rates. DNAPL mass depletion rates were found to increase with increasing groundwater velocity, or increasing oxidant concentration. An interaction occurred between the two factors, where high oxidant concentrations had little impact on mass depletion rates at high velocities. High oxidant concentration systems experienced gas generation. Mass depletion rates were fastest at high velocities, but required additional oxidant mass and pore volume addition to achieve complete mass depletion. Lower-velocity systems were more efficient with respect to oxidant mass and pore volume requirements, but mass depletion rates were reduced.

Les réseaux Telecom sont désormais en charge du transport d’une large variété de trafic de types donnés, voix, vidéo et autres protocoles industriels réclamant des garantie de qualité de service strictes. L’ingénierie de trafic permet non seulement d’optimiser les ressources réseaux mais aussi de parvenir à garantir ces qualités de service exprimées en termes de délais dans le réseau, de gigue mais aussi de taux de disponibilité en présence de pannes de liens ou de nœuds. La technologie MPLS TE, basée sur la commutation de labels le long de chemins contraints a permis d’atteindre ces objectifs et fut déployée dans de nombreux réseaux. L’objectif de cette thèse est de proposer un nouveau modèle architectural nommé PCE, ainsi que des protocoles et algorithmes novateurs afin de résoudre plusieurs problèmes d’envergure liés à l’ingénierie de trafic et disponibilité du réseau. L’architecture PCE est tout d’abord décrite ainsi que le protocole de signalisation PCEP utilisé entre clients et serveurs, puis les protocoles de découvertes de PCE et algorithmes de partage de charge. Ensuite un nouvel algorithme récursif est spécifié permettant grâce à un calcul collaboratif et récursif distribué impliquant une suite de PCEs de calculer le chemin optimal pour des tunnels inter-domaines. Un nouveau paradigme pour le calcul des chemin de secours est spécifié qui permet à chaque nœud d’agir en tant que PCE pour le calcul des tunnels de secours de chacun de ses voisins dans l’hypothèse que sa propre panne, permettant une utilisation partagée des ressources réseau dédiées au secours pour des tunnels protégeant des ressources indépendantes... / Modern data networks carry a wide variety of traffic such as voice, video, data and other industrial protocols that require guaranteed quality of service. Traffic Engineering (TE) allows for network resource optimization while meeting service level agreement for these sensitive traffics in terms of delays, jitter but also network reliability in case of network element failure. To that end a technology making use of constrained paths using label switching (called MPLS TE) has been developed and widely used in a number of networks. The objective of this thesis is to propose a new architecture model referred to as the Path Computation Element (PCE) along with a number of protocols and algorithms in order to tackle a number of technical challenges. First the PCE architecture is described in terms of functional blocks with its protocols: the signalization protocol called PCEP used between client and servers in charge of computing label switched path in the network, the process of PCE discovery and load balancing. Then a new backward recursive algorithm is specified allowing for the computation of optimal inter-domain tunnels, which involves a series of stateless PCEs. We then introduce a paradigm shift consisting distributing the computation of backup tunnels in the network used by the well-known technology called Fast Reroute. Thanks to this new paradigm, each node independently acts as a PCE computing the back tunnels of all of its neighbors, thus maximizing the degree of sharing of the backup capacity among tunnels that protect independent resources. We conclude this thesis by showing how the PCE architecture can be applied (with adaptations specified in the last two chapt...

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Chlorinated ethenes are considered one of the most prevalent sources of groundwater contamination in developed countries. Natural attenuation of chlorinated ethenes is possible through the process of microbial reductive dechlorination. Reductive dechlorination can occur in contaminated aquifers where there are sufficient amounts of organic carbon and reducing redox conditions to support dechlorinating microorganisms. Natural organic carbon (NOC) from dissolved aquifer sediment is thought to be the source of fermentable compounds needed to produce molecular hydrogen that functions as the primary electron donor for reductive dechlorination. Therefore, in an anaerobic aquifer, the production of molecular hydrogen from the fermentation of NOC drives the reductive dechlorination process. The variability and distribution of potential bioavailable organic carbon (PBOC) at a site is relatively unknown and any potential relationships between PBOC and the physical properties of the aquifer sediment have not been evaluated. Exploring relationships between the grain size of aquifer sediment PBOC may help to determine the feasibility of natural attenuation as a long-term remediation strategy at chlorinated ethene-contaminated sites. Because hydraulic conductivity is directly related to aquifer sediment grain size, zones of high hydraulic conductivity may promote greater microbial activity or biodegradation because of the increased availability of PBOC and nutrient flux. To determine potential relationships between PBOC and aquifer sediment grain size, two experiments were performed. PBOC was measured for 106 sediment samples impacted by chlorinated solvent contamination from an anaerobic type II site through a multiple liquid extraction process (Rectanus et al. 2007). Grain size distributions for each of the 106 sediment samples were determined by conducting sieve analyses. The results of both experiments were compared to explore relationships between PBOC and sediment grain size and to evaluate spatial distribution of both in the surficial aquifer. / Master of Science

Diploma thesis deals with the use of organic materials in photovoltaic applications and the study of their electric and dielectric properties. The theoretical part of thesis deals issue of the use of organic polymeric materials in photovoltaics and their advantages and disadvantages. Next are the results of various studies of organic solar cells by other authors. In the practical part of the work are shown experimental results (volt-ampere characteristics and impedance spectra) of samples of organic semiconductors and their evaluation.

Este trabalho apresenta uma análise sobre a Arquitetutra PCE (Path Computation Element), como alternativa para o roteamento inter-domínios em redes heterogêneas, ou seja, em ambientes onde ocorre a integração do domínio óptico, das redes de transporte ópticas, com o domínio eletrônico, das redes convencionais, tratando inclusive com questões de qualidade de transmissão do sinal óptico, ou QoT (Quality of Transmission). Os objetivos e o funcionamento do mecanismo do PCE em redes integradas são detalhados. São apresentados também os conceitos e definições das redes ópticas, bem como seus principais elementos, a proposta de interconexão das mesmas com as redes convencionais provendo uma rede única e integrada, o papel dos planos de controle, e os principais mecanismos de roteamento. A análise do PCE foi direcionada para o comportamento do principal protocolo utilizado na sua arquitetura, denominado PCE Protocol. De forma mais específica, foi realizada a análise de suas mensagens de requisição de rotas e das mensagens de respostas a estas requisições, e sua interferência no tráfego dos enlaces das redes onde são introduzidas. A partir daí é apresentada uma proposta de extensão de parâmetros para o protocolo PCE Protocol, com o objetivo de atender necessidades específicas de QoT, baseado em estudos das particularidades das características das transmissões ópticas. A partir destas definições, foram realizadas análises adicionais a fim de verificar o impacto com relação ao tráfego gerado em enlaces de diferentes larguras de banda, com a definição original do protocolo, e com a extensão proposta, permitindo uma comparação entre ambos. / This thesis presents an analysis of Path Computation Element Architecture (PCE) as an alternative to be implemented in heterogeneous network inter-domain routing, in other words, environments where optical domains are integrated with the electronic domains of conventional networks. Also, the ability of PCE to manage issues regarding the transmission quality of the optical signal, the QoT (Quality of Transmission), is presented. Objectives and functionality of the PCE mechanism in integrated networks is detailed. Concepts and definitions regarding optical networks and their main elements, the aim of interconnection with conventional networks to build a unified and integrated network, the role of control planes, and the main routing mechanisms are also presented. The analysis of the PCE was focused on the behavior of its main protocol, called PCE Protocol. Specifically, the analysis was performed on both its request and response messages, in addition, the interference in the traffic of the links where these messages had been introduced was also analyzed. Afterwards, an extension of the PCE Protocol parameters was proposed based on the study of optical transmission characteristics, with the aim of meeting specific QoT requirements. From these definitions, further analyses of the impact on the traffic in links with different bandwidths were performed, using the PCE protocol, with and without the proposed extension, allowing a comparison between them.