O objetivo dessa pesquisa foi avaliar, com o auxilio do método fotoelástico, o comportamento das tensões sobre as estruturas de suporte da prótese total mandibular, nas seguintes condições: 1. Prótese total com base confeccionada de forma convencional com resina acrílica; 2.Prótese total com base de resina acrílica e uma camada de material resiliente à base de silicone. Para o experimento foram confeccionadas 4 próteses totais, sendo uma com base de resina acrílica e 3 com bases de resina acrílica e material resiliente, com espessuras de 1mm, 2mm e 3mm. As 4 próteses, mais o modelo fotoelástico, constituíram os corpos de prova denominados: CPO (base de resina ); CP1; CP2 e CP3 (bases de resina e material resiliente). As condições de carregamento foram feitas com 0,5; 1,0; 1,5 e 2,0 bars, nesta seqüência, para cada corpo de prova. A seqüência de ensaios mostrou um comportamento de distribuição de tensões menos abrangente para o corpo de prova de base acrílica CP0, com as tensões concentradas na crista do rebordo e em pontos mais localizados na extensão da área basal, enquanto que os corpos de prova com material resiliente, CP1, CP2 e CP3, mostraram maior abrangência na distribuição das tensões para modelo, com franjas fotoelásticas mais extensas, à medida que a camada resiliente era mais espessa. Observou-se ainda, que com o aumento da espessura da camada resiliente, houve uma redução na largura e na intensidade das franjas, realizada de maneira mais uniforme e ampla, gerando intensidades menores e menos concentradas. As conclusões a que se chegou foram: 1. O corpo de prova de base acrílica CP0, apresentou concentração de tensões na crista do rebordo e em alguns pontos mais localizados da extensão da área basal do modelo fotoelástico, para todas as condições de carregamento; 2. Os corpos de prova com resina acrílica e material resiliente, CP1, CP2 e CP3 promoveram uma distribuição de tensões mais abrangentes no modelo fotoelástico; 3. O CP2 foi o que apresentou maior alteração na intensidade das tensões, na seqüência de imagens de 0,0 de carga até o carregamento máximo de 2,0 bars. O comportamento apresentado pelo CP1, sob todas as condições de carregamento e sob todos os aspectos avaliados, parece ser o mais recomendável para bases de próteses totais, compostas de resina acrílica e material resiliente à base de silicone. / The objective of this study was to evaluate the stress distribution under support structures of full dentures with acrylic and resilient base. The methodology used was the photoelastic analysis in four different conditions, full denture with acrylic base and full denture with acrylic and resilient base with different thickness (1mm, 2mm and 3mm). Like this a dry human skull was reproduced in photoelastic resin material and its lower dental arch was shaped in order to simulate an edentulous arch. In this way, four dentures were prepared and the load tests were done. The load distribution along the lower jaw was assessed by photoelastic stress analysis and showed that in denture with conventional acrylic base the loads were more concentrated and located in some areas whereas in dentures with conventional acrylic base and resilient base the loads were more uniformly distributed. The results and observed aspects suggested that the better thickness for denture resilient liners considering the stress distribution is 1mm although the 2mm and 3mm are also good to distribute the loads more uniformly than the acrylic hard base.

The first part of the thesis focuses on developing a numerical methodology to simulate the acoustic properties of a hybrid liner consisting of a perforated plate, a porous layer and a Helmholtz cavity. Liners are always a standard way to reduce noise in today’s aeroengines, e.g. the fan noise can be reduced effectively through the installation of acoustic liners as wall treatments in the ducts. In order to optimize a liner in the design phase, an accurate and efficient prediction tool is of interests. Hence, a unified Linearized Navier-Stokes equations(LNSE) approach has been implemented in the thesis, combining the LNSE in frequency domain with the fluid equivalent model. The LNSE is applied in the vicinity of the perforated plate to simulate sound propagation including viscous damping effect, and the fluid equivalent model is used to model the sound propagation in the porous material including absorption. The second part of the thesis focuses on the prediction of thermoacoustic instabilities. Thermoacoustic instabilities arise when positive coupling occurs between the flame and the acoustics in the feedback loop, i.e. the flame acts as an amplifier of the disturbances (acoustic or fluid) at a natural frequency of the combustion system. Once the thermoacoustic instabilities occur, it will lead to extremely high noise levels within a relatively narrow frequency range, resulting in a huge damage to the structure of the combustors. Hence, a solution must be found, which breaks the link between the combustion process and the structural acoustics. The numerical prediction of thermoacoustic instabilities in the thesis is performed by two different numerical methodologies. One solves the Helmholtz equation in combination of the flame n − tau model with the low Mach number assumptions, and the other solves the Linearized Navier-Stokes equations in frequency domain with mean flow. The result show that the mean flow has a significant effect on the thermoacoustic instabilities, which is non-negligible when the Mach number reaches to 0.15. / <p>QC 20151221</p> / TANGO

Culverts throughout the country are approaching or are past their original design lives. These ‘baby boomer’ culverts will need to be repaired, rehabilitated, or replaced. Because entire culvert replacement is so expensive and intrusive, alternate measures to extend the culvert project life are growing increasingly popular. One such method is slip lining, where a ‘sleeve’ is installed within an existing culvert barrel and stabilized. Plastic pipe sleeves are very popular for slip lining primarily because the plastic material's lower Manning's roughness values allow for the culvert capacity to be maintained despite a reduction in culvert size. Unfortunately, the reduced friction within the barrel can create a barrier to fish passage due to increased water velocities. The increased velocities also cause greater outlet scour which can result in further obstacles to fish passage. These new fish barriers can greatly affect aquatic ecosystems by limiting the access that fish have to smaller tributaries used for spawning and rearing—access that is critical to the life cycles of many fish. It is suggested that mitigation of the increased velocities should go hand-in-hand with slip lined culvert design projects where fish passage (present or future) is to be considered. Can the demand for hydraulic capacity as well as the demand for fish passage be satisfied? Careful design and installation, coupled with post-project monitoring can result in slip lined culvert retrofits which successfully pass fish. Investigation of federal and state laws and various agency guidelines has informed the creation of a list of culvert conditions which should prompt consideration of slip lined culvert retrofit among other design alternatives. Additionally, a literature review and survey of all U.S. state Departments of Transportation as well as state Fish and Wildlife Departments has shown that there has been very limited experience in providing for fish passage through slip lined culverts. Literature and practice has pointed to the use of baffles and tailwater control weirs for velocity mitigation. Site visits have been made to the few states with this experience to assess developing technologies and record successful and unsuccessful installations. Additional hydraulic analysis using current software suggests general trends in the effects slip lined culvert retrofits on flow type, headwater, velocity as well as the effects of tailwater control weirs. Issues of sustainability, constructability and maintenance, as well as monitoring are addressed.

Die vorliegende Arbeit befasst sich mit dem Einfluss der Porosität lichtbogendrahtgespritzter Zylinderlaufbahnen auf das Reibungsverhalten. Hierzu wird das fokussierte System aus Kolbenring, Schmierstoff und Lauffläche zunächst für einen repräsentativen Betriebspunkt per numerischer Abschätzung der Kolbenringzwischendrücke sowie der Schmierfilmdicke analysiert und eine Einteilung der Reibungszustände vorgenommen. Unter anderem auf Basis der strömungsmechanischen Ähnlichkeitstheorie erfolgt im Anschluss eine Ableitung von Betriebspunkten für experimentelle Untersuchungen an einem Mittelhub-Tribometer im Bereich der Grenzreibung sowie Mischreibung und Hydrodynamik. An diesem Modellprüfstand werden daraufhin zum einen Laufbahnsegmente differenter Porosität gegen einen nitrierten Kompressionsring bewertet. Neben skalaren Größen dienen wegaufgelöste Signale über dem Hub zur Analyse des Reibungsverhaltens. In Ergänzung zu den nitrierten Oberflächen wird das Potenzial einer ta-C Beschichtung zur Reibungsreduzierung bewertet. Die Übertragbarkeit der erarbeiteten Erkenntnisse auf den verbrennungsmotorischen Betrieb wird über eine Messreihe an einem Einzylinderprüfstand untersucht. Auch hier werden Oberflächendaten verwendet, um eine Korrelation zwischen den ermittelten Reibmitteldrücken respektive den wegaufgelösten Signalen und der Porosität herstellen zu können. Über diese experimentellen Untersuchungen hinaus wird das Verhalten des Schmierfilms zwischen dem Kolbenring und einzelner Poren der Lauffläche mit Hilfe der dreidimensionalen numerischen Strömungssimulation analysiert. Hierzu werden Laufbahnsegmente per Computertomographie vermessen, einzelne Porenobjekte isoliert und für die Simulation aufbereitet. Im Rahmen von stationären Berechnungen wird zunächst eine Vielzahl einzelner Objekte in einem abstrahierten System strömungsmechanisch untersucht. Die Analyse ausgewählter Poren in transienten Strömungssimulationen und die Bewertung der Übertragbarkeit der Erkenntnisse schließen diese Arbeit ab.:1. Einleitung und wissenschaftliche Zielsetzung 1.1. Einführung 1.2. Zielsetzung und Aufbau der Arbeit 2. Grundlagen 2.1. Grundlagen der Tribologie 2.1.1. Reibung 2.1.2. Verschleiß 2.1.3. Schmierung und Schmierstoffe 2.2. Geometrische Charakterisierung von Oberflächen 2.3. Amorphe Kohlenstoffschichten 2.4. Kolbengruppe und Zylinderlaufbahn 2.5. Strömungsmechanik 2.5.1. Strömungsmechanische Grundlagen 2.5.2. Grundgleichungen der Strömungsmechanik 3. Methoden 3.1. Topographie von Oberflächen 3.1.1. Konfokalmikroskopie 3.1.2. Computertomographie 3.2. Untersuchung tribologischer Eigenschaften 3.2.1. Mittelhub-Tribometer 3.2.2. Einzylinderprüfstand 3.3. Numerische Strömungssimulation 3.3.1. Vernetzungsmethoden 3.3.2. Finite-Differenzen-Methode 3.3.3. Finite-Volumen-Methode 3.3.4. Instationäre Strömungen 3.3.5. Turbulente Strömungen 3.3.6. Kompressible Strömungen 4. Analyse des Systems aus Kolbenring, Schmierstoff und Zylinderlaufbahn 4.1. Bewertung der Kolbenringzwischendrücke 4.2. Numerische Berechnung der Schmierfilmdicke 4.3. Analyse der Reibzustände 5. Experimentelle Analyse 5.1. Untersuchungen am Mittelhub-Tribometer 5.1.1. Ableitung der Betriebspunkte, des Prüfablaufs und der Versuchsmatrix 5.1.2. Analyse der Oberflächen der Versuchsteile 5.1.3. Signalaufbereitung und -bewertung 5.1.4. Ergebnisse im Bereich der Grenzreibung 5.1.5. Ergebnisse im Bereich der Mischreibung und Hydrodynamik 5.2. Untersuchungen am befeuerten Einzylinderprüfstand 5.2.1. Prüfablauf und Versuchsmatrix 5.2.2. Analyse der Oberflächen der Versuchsteile 5.2.3. Ergebnisse der Messungen am Einzylinderprüfstand 5.3. Übertragbarkeit der Messergebnisse für den repräsentativen Betriebspunkt 6. Strömungssimulation des Schmierfilms 6.1. Extraktion und Aufbereitung der Poren aus der Zylinderlaufbahn 6.1.1. Vermessung und Aufbereitung der Laufbahnsegmente 6.1.2. Extraktion und Aufbereitung der Poren 6.2. Stationäre Strömungssimulation 6.2.1. Modellierung des Systems und Automatisierung der Berechnung 6.2.2. Ergebnisse 6.3. Transiente Strömungssimulation 6.3.1. Modellierung des Systems 6.3.2. Ergebnisse 7. Zusammenfassung und Ausblick 7.1. Zusammenfassung 7.2. Ausblick Literatur Abbildungsverzeichnis Tabellenverzeichnis Nomenklatur A. Anhang A.1. Anhang zu Kapitel 5 A.2. Anhang zu Kapitel 6 / This work deals with the influence of the porosity of twin wire arc sprayed cylinder liner on the friction behavior. For this purpose, the focused system of piston ring, lubricant and liner is first analyzed for a representative operating point by numerical estimation of the piston ring intermediate pressures as well as the lubricant film thickness and a classification of the friction states is carried out. Among other things, based on the mechanics of flow similarities, a calculation of operating points for experimental investigations on a medium stroke tribometer in the field of boundary friction as well as mixed and hydrodynamic friction is done subsequently. After that, on this model test bench, cylinder segments of different porosity are evaluated against a nitrided piston ring. Beside scalar values, signals above the stroke are used to analyze friction behavior. In addition to the nitrided surfaces, the potential of a ta-C coating for friction reduction is investigated. The transferability of the developed findings to the combustion-engined operation is evaluated via a series of measurements on a single cylinder test bench. Here, too, surface data is used to establish a correlation between the mean effective pressure of frictional forces determined or the signals above the stroke and the porosity. In addition to these experimental investigations, the behaviour of the lubricant film between the piston ring and single pores of the cylinder surface is evaluated using the three-dimensional numerical flow simulation. For this purpose, liner segments are measured by computed tomography, individual pore objects are isolated and processed for simulation. In the context of stationary calculations, a large number of individual objects are first examined in an abstracted system. The analysis of selected pores in transient flow simulations and the evaluation of the transferability of the findings complete this work.:1. Einleitung und wissenschaftliche Zielsetzung 1.1. Einführung 1.2. Zielsetzung und Aufbau der Arbeit 2. Grundlagen 2.1. Grundlagen der Tribologie 2.1.1. Reibung 2.1.2. Verschleiß 2.1.3. Schmierung und Schmierstoffe 2.2. Geometrische Charakterisierung von Oberflächen 2.3. Amorphe Kohlenstoffschichten 2.4. Kolbengruppe und Zylinderlaufbahn 2.5. Strömungsmechanik 2.5.1. Strömungsmechanische Grundlagen 2.5.2. Grundgleichungen der Strömungsmechanik 3. Methoden 3.1. Topographie von Oberflächen 3.1.1. Konfokalmikroskopie 3.1.2. Computertomographie 3.2. Untersuchung tribologischer Eigenschaften 3.2.1. Mittelhub-Tribometer 3.2.2. Einzylinderprüfstand 3.3. Numerische Strömungssimulation 3.3.1. Vernetzungsmethoden 3.3.2. Finite-Differenzen-Methode 3.3.3. Finite-Volumen-Methode 3.3.4. Instationäre Strömungen 3.3.5. Turbulente Strömungen 3.3.6. Kompressible Strömungen 4. Analyse des Systems aus Kolbenring, Schmierstoff und Zylinderlaufbahn 4.1. Bewertung der Kolbenringzwischendrücke 4.2. Numerische Berechnung der Schmierfilmdicke 4.3. Analyse der Reibzustände 5. Experimentelle Analyse 5.1. Untersuchungen am Mittelhub-Tribometer 5.1.1. Ableitung der Betriebspunkte, des Prüfablaufs und der Versuchsmatrix 5.1.2. Analyse der Oberflächen der Versuchsteile 5.1.3. Signalaufbereitung und -bewertung 5.1.4. Ergebnisse im Bereich der Grenzreibung 5.1.5. Ergebnisse im Bereich der Mischreibung und Hydrodynamik 5.2. Untersuchungen am befeuerten Einzylinderprüfstand 5.2.1. Prüfablauf und Versuchsmatrix 5.2.2. Analyse der Oberflächen der Versuchsteile 5.2.3. Ergebnisse der Messungen am Einzylinderprüfstand 5.3. Übertragbarkeit der Messergebnisse für den repräsentativen Betriebspunkt 6. Strömungssimulation des Schmierfilms 6.1. Extraktion und Aufbereitung der Poren aus der Zylinderlaufbahn 6.1.1. Vermessung und Aufbereitung der Laufbahnsegmente 6.1.2. Extraktion und Aufbereitung der Poren 6.2. Stationäre Strömungssimulation 6.2.1. Modellierung des Systems und Automatisierung der Berechnung 6.2.2. Ergebnisse 6.3. Transiente Strömungssimulation 6.3.1. Modellierung des Systems 6.3.2. Ergebnisse 7. Zusammenfassung und Ausblick 7.1. Zusammenfassung 7.2. Ausblick Literatur Abbildungsverzeichnis Tabellenverzeichnis Nomenklatur A. Anhang A.1. Anhang zu Kapitel 5 A.2. Anhang zu Kapitel 6

In modern, low emission, gas turbine combustion systems the amount of air available for cooling of the flame tube liner is limited. This has led to the development of more complex cooling systems such as cooling tiles i.e. a double skin system, as opposed to the use of more conventional cooling slots i.e. a single skin system. An isothennal experimental facility has been constructed which can incorporate 10 times full size single and double skin (cooling tile) test specimens. The specimens can be tested with or without effusion cooling and measurements have been made to characterise the flow through each cooling system along with the velocity field and cooling effectiveness distributions that subsequently develop along the length of each test section. The velocity field of the coolant film has been defined using pneumatic probes, hot-wire anemometry and PIV instrumentation, whilst gas tracing technique is used to indicate (i) the adiabatic film cooling effectiveness and (ii) mixing of the coolant film with the mainstream flow. Tests have been undertaken both with a datum low turbulence mainstream flow passing over the test section, along with various configurations in which large magnitudes and scales of turbulence were present in the mainstream flow. These high turbulence test cases simulate some of the flow conditions found within a gas turbine combustor. Results are presented relating to a variety of operating conditions for both types of cooling system. The nominal operating condition for the double skin system was at a coolant to mainstream blowing ratio of approximately 1.0. At this condition, mixing of the mainstream and coolant film was relatively small with low mainstream turbulence. However, at high mainstream turbulence levels there was rapid penetration of the mainstream flow into the coolant film. This break up of the coolant film leads to a significant reduction in the cooling effectiveness. In addition to the time-averaged characteristics, the time dependent behaviour of the .:coolantfilm was. also investigated. In particular, unsteadiness associated with large scale structures in the mainstream flow was observed within the coolant film and adjacent to the tile surface. Relative to a double skin system the single skin geometry requires a higher coolant flow rate that, along with other geometrical changes, results in typically higher coolant to mainstream velocity ratios. At low mainstream turbulence levels this difference in velocity between the coolant and mainstream promotes the generation of turbulence and mixing between the streams so leading to some reduction in cooling effectiveness. However, this higher momentum coolant fluid is more resistant to high mainstream turbulence levels and scales so that the coolant film break up is not as significant under these conditions as that observed for the double skin system. For all the configurations tested the use of effusion cooling helped restore the coolant film along the rear of the test section. For the same total coolant flow, the minimum value of cooling effectiveness observed along the test section was increased relative to the no effusion case. In addition the effectiveness of the effusion patch depends on the amount of coolant injected and the axial location of the patch. The overall experimental data suggested the importance of the initial cooling film conditions together with better understanding of the possible mechanisms that results in the rapid cooling film break-up, such as high turbulence mainstream flow and scales, and this will lead to a more effective cooling system design. This experimental data is also thought to be ideal for the validation of numerical predictions.

[pt] O liner é um elemento de extrema importância no processo construtivo de um aterro sanitário, pois funciona como uma barreira capaz de impedir a percolação de agentes contaminantes através do subsolo. Os liners ou camadas impermeabilizantes são geralmente construídos a partir de materiais que possuem baixa permeabilidade. A escolha de um material adequado, assim como o controle dos processos construtivos são indispensáveis para garantir um bom desempenho da camada impermeabilizante. O processo de compactação é de extrema importância neste tipo de obra geotécnica. Os ensaios de compactação realizados em laboratório têm como objetivo reproduzir as condições de campo, no entanto, em numerosos casos há diferenças importantes entre os mecanismos de compactação utilizados, na preparação do material antes do processo de densificação e nas características das amostras, o que gera como conseqüência discrepâncias nos valores de permeabilidade de campo com os de laboratório. O objetivo principal do presente estudo é avaliar experimentalmente a influência de dois mecanismos diferentes de compactação (dinâmico, com o Proctor Normal e estático, com o método de compactação por pisoteamento) nos valores de permeabilidade de um solo coluvionar e de um composto orgânico para seu eventual uso em um liner. Os ensaios foram realizados em corpos de prova com diferentes teores de umidade, preparados com solo coletado no campo Experimental II da PUC-Rio, com composto orgânico produzido a partir do processo de compostagem da grama do Aeroporto Internacional Galeão (RJ), e com misturas em diferentes proporções de ambos os materiais. / [en] The liner is one of the most important elements in a sanitary landfill project, since it works as a barrier capable to impede seepage of pollutant substances through the subsurface. This element is usually built with materials that have low permeability. The choice of the right material as well as the control and supervision of the constructive processes are fundamental to achieve a good liner performance. The compaction process is extremely important in this type of geotechnical impoundment. Laboratory compaction intends to reproduce the field conditions; however, in some cases, there happen to be important differences between the compaction mechanisms used, the preparation of the material before the densification process and the specimens characteristics, which cause discrepancies between the permeability values obtained in the field and the ones obtained in the laboratory. The main objective of this study is to evaluate experimentally the effect of two different compaction mechanisms (dynamic, with standard Proctor and static, with the kneading compaction method) in the hydraulic conductivity of a colluvionar soil and an organic compound for their eventual use in a liner. The tests were executed using specimens with different water contents, prepared with colluvionar soil extracted from the Experimental Field II at the PUC-Rio, with the organic compound, and with mixtures of both materials in different proportions.

A utilização do solo natural compactado com bentonita empregado em camadas impermeáveis para retenção de contaminantes é bastante usual para aterros sanitários. Neste trabalho são apresentados resultados de ensaios condutividade hidráulica e de resistência ao cisalhamento, realizados em equipamentos triaxiais. Além do solo natural, foram utilizadas misturas solo-bentonita nos teores de 2%, 4% e 6%. O solo arenoso ensaiado é encontrado na Planície Costeira Sul do Estado do Rio Grande do Sul. Os valores de condutividade hidráulica diminuiram tanto com o acréscimo do teor de bentonita, quanto com o aumento da tensão de confinamento. A condutividade hidráulica do solo apresentou uma redução de três ordens de grandeza quando este foi compactado com 6% de bentonita (de \'10 POT.-7\' para \'10 POT.-10\' m/s). Em relação a resistência ao cisalhamento do material, constatou-se que com o acréscimo do teor bentonita de 0 para 6%, a coesão efetiva aumentou (de 2,3 para 12,8 kPa) e o ângulo de atrito efetivo diminuiu (de 22,7º pra 14,0º). / Compacted soil-bentonite mixtures used as impermeable layers for retention of contaminants is quite usual in landfills. This paper presents the results of hydraulic conductivity and shear strength tests conducted in a triaxial apparatus. Natural soil, and soil-bentonite mixtures at 2%, 4% and 6% concentrations were tested. The sandy soil tested is found in the Southern Coastal Plain of Rio Grande do Sul. The hydraulic conductivity decreased with both the increase of bentonite content and increase of confining stress. Compared to natural soil, the hydraulic conductivity of compacted soil-bentonite mixtures at 6% content decreased by three orders of magnitude (from \'10 POT.-7\' to \'10 POT.-10\' m/s). Regarding the material shear strength, it was found that when the natural soil is compared to compacted soil-bentonite mixtures at 6% content, the effective cohesion increased (from 2.3 to 12.8 kPa) and the effective friction angle decreased (from 22. 7º to 14.0º).

La réduction des nuisances sonores est un enjeu permanent pour les acteurs de l'aéronautique. L'optimisation de la réduction de bruit apportée par les traitements acoustiques tapissant la nacelle des réacteurs turbofan passe par une caractérisation précise des matériaux employés dans l'environnement aéroacoustique d'utilisation, qui met en jeu un écoulement rasant de vitesse importante combiné à de forts niveaux sonores. L'objectif de cette thèse est de développer une méthode inverse pour la détermination de l'impédance acoustique de liners soumis à un écoulement rasant, basée sur des mesures non intrusives du champ de vitesse acoustique au-dessus du matériau par Vélocimétrie Laser Doppler (LDV). L'impédance de liner est obtenue par minimisation de l'écart entre le champ de vitesse acoustique mesuré et le champ simulé numériquement en résolvant les équations d'Euler linéarisées bidimensionnelles harmoniques, discrétisées par un schéma Galerkin discontinu. Le gradient de la fonction objectif minimisée est calculé via la résolution, à chaque itération, des équations directes et adjointes. Une première étape de validation du solveur est effectuée sur des cas-tests académiques, puis sur des cas expérimentaux impliquant des mesures de pression acoustique en paroi rigide opposée au liner. Dans un second temps, la méthode est appliquée à des mesures de vitesse acoustique obtenues par LDV dans le banc B2A de l'ONERA en l'absence d'écoulement. La dernière étape consiste à prendre en compte l'effet d'un écoulement rasant de profil cisaillé. Les impédances identifiées à partir de mesures LDV en présence d'écoulement ont notamment permis de gagner en compréhension sur les phénomènes d'absorption intervenant dans le banc B2A.

No description available.

In maritime transportation, liner shipping accounts for over 60\% of the value of goods shipped. However, very limited literature is available on the study of various problems in liner shipping. In this thesis we focus on problems related to this industry. Given a set of cargo to be transported, a set of ports and a set of ships, a common problem faced by carriers in liner shipping is the design of their service network. We develop an integrated model to design service network for the ships and to route the available cargo, simultaneously. The proposed model incorporates many relevant constraints, such as the weekly frequency constraint on the operated routes, and emerging trends, such as obtaining benefits from transshipping cargo on two or more service routes, that appear in practice but have not been considered previously in literature. Also, we design exact and heuristic algorithms to solve the integer program efficiently. The proposed algorithms integrate the ship scheduling problem, a tactical planning level decision, and the cargo routing problem, an operational planning level decision, and provide good overall solution strategy. Computational experiments indicate that larger problem instances, as compared to the literature, can be solved using these algorithms in acceptable computational time. Alliance formation is very common among global liner carriers however a quantitative study of liner alliances is missing from literature. We provide a mathematical framework for the quantitative study of these alliances. For the formation of a sustainable alliance, carriers need to agree on an overall service network and resolve issues concerning distribution of benefits and costs among the members of the alliance. We develop mechanisms to design a collaborative service network and to manage the interaction among the carriers through the allocation of profits in a fair way. The mechanism utilizes inverse optimization techniques to obtain resource exchange costs in the network. These costs provide side payments to the members, on top of the revenue generated by them in the collaborative solution, to motivate them to act in the best interest of the alliance while satisfying their own self interests.