Intelligent Transportation Systems (ITS) has impulsed the vehicular communications at the present time. The vehicular communications field is a hot research topic and is attracting a great interest in the automotive industry and telecommunications. There are essentially two main lines of work: (1) communication services related to road safety and traffic information; and (2) information and entertainment services, also named infotainment services. These latter services include both transmitting multimedia (voice over IP, streaming, on-line gaming, etc.) and classic data services (e-mail, access to private networks, web browsing, file sharing, etc.). In this thesis we will focus on these infotainment services because further research in this immature research field is necessary and, until nowadays, the main effort of the research community regarding vehicular communication has been focused on road safety and traffic information. Vehicular nodes need to be reached from the Internet and vice versa to be able to access to infotainment services. While vehicles move along the road infrastructure, they change their wireless point of attachment to the network. During this process, connectivity breaks down until the vehicle is connected again to a new road side unit in its area. This disconnection causes a disruption in the communications. Fast handoffs are a crucial requirement for vehicular networks to avoid long disruption times, since the high speed of vehicular nodes involves suffering a lot of handoffs during an Internet connection. This thesis is focused on Vehicular-to-Infrastructure (V2I) real-time infotainment services. The main contributions of this thesis are: i) a new testing framework for V2I communications to be able to test infotainment services in an easy way; ii) the analysis of the deployability of infotainment video services in vehicular networks using mobility protocols; and iii) the development of a new TCP architecture that will provide a better performance for all TCP-based infotainment services in a vehicular scenario with handoffs. In this thesis, firstly, we propose a new testing framework for vehicular infotainment applications. This framework is a vehicular emulation platform that allows testing real applications installed on Linux virtual machines. Using emulation, we are able to evaluate the performance of real applications with real-time requirements, so we can test multimedia applications used to offer infotainment services in vehicular scenarios in a straightforward way. Secondly, using the testing framework implemented in the first part of the thesis, we have done a performance evaluation of an infotainment service. Among these services, we think that video on demand services on highways will be interesting for users, and generate revenue to network operators. So we evaluated how network-layer handoffs can limit the deployment of a video streaming service. According to the results obtained, driving at high speeds will be an issue for a correct playback of video content, even using fast handoffs techniques. Finally, we developed a new TCP architecture to enhance performance during handoffs. Most of the non-safety services on ITS rely on the Transport Control Protocol (TCP), one of the core protocols of the Internet Protocol Suite. However there exists several issues related to TCP and mobility that can affect to TCP performance, and these issues are particularly important in vehicular networks due to its high mobility. Using new IEEE 802.21 MIH services, we propose a new TCP architecture that is able to anticipate handoffs, permitting to resume the communication after a handoff, avoiding long delays caused by TCP issues and adapting the TCP parameters to the new characteristics of the network. Using the architecture proposed, the performance of TCP is enhanced, getting a higher overall throughput and avoiding TCP fairness issues between users. / Els Sistemes de Transport Intel·ligents (ITS) han impulsat les comunicacions vehiculars en l'actualitat. Les comunicacions vehiculars és un camp d'investigació de moda, i està atraient un gran interès en la indústria automobilística i de les telecomunicacions. En el camp de les comunicacions vehiculars, hi ha principalment dues línies de treball: (1) serveis de comunicacions relacionats amb la seguretat viària i la informació del trànsit; i (2) serveis d'informació i entreteniment, també anomenats serveis d'infotainment. Aquests últims inclouen tant serveis multimèdia (veu sobre IP, streaming, jocs on-line, etc.), com serveis clàssics de dades (correu electrònic, accés a xarxes privades, navegació web, compartir arxius, etc.). En aquesta tesi ens centrarem en aquests serveis d'infotainment ja que és necessari aprofundir en la investigació per aquests tipus de serveis, ja que, fins avui, els esforços de la comunitat científica en el camp de les comunicacions vehiculars s'ha centrat en els serveis relacionats amb la seguretat viària i la informació del trànsit. Els nodes vehiculars necessiten tenir connexió a Internet per a poder tenir accés als serveis d'infotainment. Mentre els vehicles estan en moviment a través de la xarxa viària, els vehicles han d'anar canviant el punt de connexió sense fils amb la xarxa. Durant aquest procés de canvi de punt de connexió, anomenat handoff, es perd la connectivitat fins que el vehicle es reconnecta a un altre punt de connexió viària prop de la seva àrea. Aquesta desconnexió causa interrupcions en les comunicacions. Uns handoffs ràpids són bàsics a les xarxes vehiculars per a evitar llargs períodes d'interrupció durant les comunicacions, ja que la gran velocitat a la que es mouen els nodes vehiculars significa un gran nombre de handoffs durant una connexió a Internet. Aquesta tesi es centra en serveis d'infotaiment en temps real per a comunicacions Vehicle-a-Infraestructura (V2I). Les principals contribucions d'aquesta tesi son: i) un nou marc de proves per a les comunicacions (V2I) per a poder provar serveis d'infotainment d'una manera fàcil; ii) l'anàlisi de la viabilitat del desplegament de serveis d'infotainment de vídeo en xarxes vehiculars utilitzant protocols de mobilitat IP; i iii) el desenvolupament d'una nova arquitectura TCP que proporciona un millor funcionament per a tots aquells serveis d'infotainment basats en el protocol TCP en un escenari vehicular amb handoffs. En aquesta tesi, primer proposem un nou marc de proves per a aplicacions vehiculars d'infotainment. Aquest marc és una plataforma d'emulació vehicular que permet provar aplicacions reals instal·lades en màquines virtuals Linux. Utilitzant l'emulació, som capaços d'avaluar el rendiment d'aplicacions reals amb característiques de temps real. D'aquesta manera es poden avaluar aplicacions multimèdia utilitzades per oferir serveis d'infotainment d'una forma senzilla en escenaris vehiculars. Segon, utilitzant el marc de prova implementat en la primera part de la tesi, hem avaluat el rendiment d'un servei d'infotainment. Entre aquest tipus de servei, creem que els serveis de vídeo sota demanda en autopistes/autovies serà interessant pels usuaris i generarà beneficis per als operadors de la xarxa. Per tant, hem avaluat com els handoffs a nivell de la capa de xarxa poden limitar el desplegament d'un servei de streaming de vídeo sota demanda. D'acord amb els resultats obtinguts, conduir a grans velocitats podria ser un problema per a poder reproduir un vídeo correctament, tot i utilitzar tècniques de handoffs ràpids. Finalment, hem desenvolupat una nova arquitectura TCP per a millorar el rendiment del protocol durant els handoffs. La majoria dels serveis d'infotainment utilitzen el Protocol de Control de Transport (TCP), un dels principals protocols de la pila de protocols d'Internet. Però existeixen forces problemes relacionats amb l'ús de TCP i la mobilitat que n'afecta el rendiment, i aquests problemes són particulars

La presente investigación, fundamentada dentro de las perspectivas humanísticas cualitativas, tiene como objetivo aportar los conocimientos en el marco de la movilidad y del espacio público, con el fin de generar lineamientos que permitan promover un estilo de vida urbana centrado en la integración entre distintos modos de transportes públicos motorizados y no motorizados. En la primera parte de la tesis, se evidencia buenas prácticas urbanas donde la inserción de sistemas de transportes masivos, ha beneficiado la movilidad y favorecido el mejoramiento de la calidad de los espacios públicos, convirtiendo la ciudad en un referente urbano. La construcción del marco conceptual, permitió validar la hipótesis de investigación planteada, “El impacto de la inserción del Metro, como una buena práctica para la planificación del transporte, se minimiza si no se considera la diversidad, la accesibilidad y la cualificación de sus espacios públicos, como indicadores para el manejo de la movilidad”. La ciudad del municipio Maracaibo, con 1.450.665 habitantes y un territorio de 393 Km2, ha evidenciado un incremento en el desmejoramiento del sistema de Transporte urbano en los últimos años, acumulando demandas insatisfechas como resultado de las limitaciones y circunstancias internas y externas del servicio, impidiendo una previsiva y adecuada dirección de la ciudad, por ende, la movilidad llega a ser insostenible, dirigida al automóvil. La inserción del metro en la ciudad, se posiciona en la actualidad como un escenario que evidencia una desarticulación entre las políticas de intervención del espacio público deseable y los modelos de desarrollo de los medios de transporte que facilitan su movilidad A partir de esta problemática, se desarrolla en la segunda parte de esta investigación, un diagnóstico situacional del Corredor de Sabaneta, donde se inserta la primera línea del Metro Maracaibo (Venezuela). Una matriz de relación, permite formular políticas, estrategias y acciones que contribuyen con el manejo de movilidad alentando de este modo patrones de usos accesibles y eficientes. Finalmente, se presenta una propuesta en tres estaciones, que resume lineamientos para el manejo de la movilidad urbana “sostenible” a través de seis vértices: a) reacondicionamiento del viario peatonal existente, b) re-organización del viario urbano – Ciclovias-, c) Nodos e intermodales, d) Reconversión de los vacíos urbanos en espacios públicos–conectividad a dos niveles-, e) mobiliario urbano y f) el arte como elemento integrador de modos de transporte. / This dissertation, which is based on qualitative and humanistic perspectives, aims at contributing with knowledge within the frame of mobility and public spaces, for the purpose of generating guidelines which will allow promoting an urban lifestyle focused on the integration amongst a number of motorized as well as non-motorized public transportation modes. Within the first part of the dissertation, good urban practices are evidenced where the insertion of massive transport systems have benefited mobility as well as favored the quality improvement of public spaces. Therefore, the city has become an urban benchmark. The construction of the conceptual framework allowed validating the proposed research hypothesis: “The impact of the subway system insertion as a good practice for transportation planning is minimized if diversity, accessibility and qualification of its public spaces are not considered, as indicators for mobility planning”. In the city of the Maracaibo municipality, with a population of 1.450,665 inhabitants, and a 2 surface area of 393 Km , it is evidenced increased deterioration of the urban transport system in recent years, as unsatisfied demands have been piling up as a consequence of the limitations, as well as internal and external service circumstances, thus preventing provident and adequate city planning. As a result, mobility becomes unsustainable, as it is intended for automobiles. The insertion of the subway system into the city currently proves to be a scenario which evidences disarticulation between desirable public space intervention policies and development models for means of transport which facilitate mobility. By taking these problems as a starting point, the second part of this research develops a situational diagnose for the Sabaneta Corridor, in which the first line of the Maracaibo subway system (Venezuela) is inserted. A SWOT matrix allows making policies, as well as devising strategies and actions for contributing to mobility planning whilst encouraging, in this manner, both accessible and efficient use patterns. Finally, a proposal is presented for three stations, which summarizes guidelines for “sustainable” urban mobility planning across six vertices: a) reconditioning of the existing urban pedestrian walkways, b) re-organization of the urban road system –cycle lanes-, c) Nodes and intermodal transport units, d) Redevelopment of urban idle spaces into public spaces –two-level connectivity-, e) street furniture, and f) art as an integration element for means of transport.

En els 200 anys compresos entre 1761, data del Pla radial de carreteres d’Espanya, i la segona meitat del segle XX es produeix la modernització del sistema de comunicacions terrestres de Catalunya. Es tracta d’un arc temporal prou llarg en el qual les noves infraestructures de transport evolucionen d’acord amb un model caracteritzat per una planificació intensiva de la xarxa de carreteres i uns ritmes irregulars de construcció de vies amb una tendència al retard endèmic en relació als plans d’origen. El contrast entre aquests dos elements principals va condicionar la consecució de la xarxa viària moderna i va establir també unes relacions específiques de concurrència entre els diversos mitjans de transport i la mobilitat que d’aquests es deriva. En l’àmbit català, el reconeixement del model descrit s’adequa perfectament a l’evolució seguida a la regió de Barcelona, i coincideix en gran part amb la divisió administrativa de la província com a marc d’actuació i gestió de la xarxa de carreteres des del segon terç del segle XIX. Les fonts històriques consultades han permès corroborar que la formació de la xarxa viària obeeix a uns cicles distingits pels arguments i criteris que justifiquen l’obertura de vies noves. En un primer moment, la planificació és assimilable a una radiografia de l’activitat econòmica del territori que té en compte l’estructura de la circulació comercial llargament consolidada; sorgeix, així, la xarxa bàsica a escala catalana com a expressió de la primera industrialització, sancionada en el Pla estatal de 1860. La potència dels nous eixos definits pel saber tècnic de l’enginyeria de camins esdevenen els canals d’una nova comunicació que es completa amb un segon moment de planificació provincial, més madura i protagonitzada per la xarxa de carreteres secundàries del darrer terç del segle XIX. La identificació de la interacció entre carreteres i territori porta a reflexionar sobre el paper fonamental de les vies en l’assoliment d’un equilibri territorial que es converteix, en un tercer cicle que té lloc durant les primeres dècades del segle XX, en una veritable acció de govern destinada a estendre la civilització per tota la geografia catalana. Són els camins veïnals com a equipaments del territori que superen amb escreix la magnitud de la planificació I també dels ritmes constructius anteriors. Avui, formen part de la xarxa de carreteres locals de Barcelona i els considerem components essencials del seu patrimonio territorial. Finament, l’arribada de l’automòbil suposa l’entrada de nous paràmetres que es concreten especialment en una visió que incorpora noves escales territorials i supera l’articulació basada en la concurrència i la intermodalitat que s’havia establert entre els carruatges i el ferrocarril. L’hegemonia del nou mitjà de transport s’imposa a partir de 1960, moment que s’instaura un cicle dual de planificació basat en l’acabament de la xarxa viària local i el començament de les vies d’alta capacitat que estructuren la Regió Metropolitana de Barcelona. / In the 200 years between 1761, (Radial Road Plan, Spain), and the second half of the 20th century witnessed the modernization of terrestrial communications system in Catalonia. It constitutes a long enough period of time in which the new transportation infrastructures evolve according with a model characterized by an intensive road network planning and some irregular road construction rhythms, with a certain endemic delay in relation to the original plans. The contrast between these two main elements conditioned the achievement of a modern road network and established some specific relations of coexistence between the diverse transport modalities and their derived mobility. In Catalonia, the described model perfectly matches the evolution of Barcelona region, and coincides largely with the administrative division of the province as an area of performance for the road network since the second third of the 19th century. The historical sources consulted corroborate that the formation that the road-network evolution follows a cycle based on the arguments that justify the new road construction. Firstly, planning becomes a territory x-ray of economic activity that takes into account the consolidated commercial mobility. It led to the Catalan-scaled basic network as a first industrialization expression, sanctioned in the state Plan of 1860. Civil engineering body of knowledge left those strong new axes behind, leading to a new communication system to be completed, in the late 19th century, by provincial planning, focusing on the secondary road network. The identification of road-territory interaction leads to consider the fundamental role of the road network in achieving a territorial balance that results in a third cycle during the early 20th century, as a true governmental action aimed to civilize the Catalan geography. These are the “veïnal” paths that widely exceed those formulated in plans as well as the previous construction rhythms. At present, they form part of Barcelona’s local network and are considered as essential elements of its landscape heritage. Finally, the arrival of the car-based mobility on the scene resulted in a vision that incorporates new territorial scales and overcomes the railway-carriage intermodal reality. Car hegemony, since 1960s, initiates a process of local road network completion and the appearance of a highway network for the Metropolitan Region of Barcelona.

The process of containerization and its continuous development involves changes and technological innovations in containerships and maritime container terminals. In the current era of "gigantism", despite existing fleet overcapacity, shipping companies are booking larger and fuel-efficient vessels to benefit from economies of scale and to reduce operating costs. Consequently, port terminals have to cope with unprecedented container volumes and increasing demands, as a result, handling operations are likely to be subject to delay. In this context, container terminals are dealing with the huge challenge of readjusting themselves in order to, on one hand, improve productivity and level of service offered to the customers (minimize turnaround time) and, on the other hand, to manage terminal handling operations efficiently with the aim of reducing operating costs and becoming more competitive. Moreover, considering that adapting facilities and terminal infrastructures involves large investment and given the lack of space in many urban ports for expanding the operational area, the improvement of handling operations efficiency is more important than ever. Thus, many efforts are required to improve the productivity of container terminals by introducing efficient solutions and optimization techniques to decision-making processes and, on the other side, introducing technological improvements such as the automation of handling equipment. In light of this, this thesis is focused on the optimization of handling operations in the storage yard, which is considered to be the most complex terminal subsystem since terminal performance depends on its efficiency. In particular, it attempts to: (1) determine optimal storage space utilization by considering the yard inventory and congestion effects on terminal performance; (2) introduce new allocating storage strategies with the aim of minimizing the amount of rehandling moves, which are considered to be the most important cause of inefficiency in container yard terminals, and; (3) develop a generic storage pricing schedule to encourage customers to pick up their containers promptly and, as a consequence, reduce the average duration of stay, avoiding yard congestion. In order to tackle these issues, two different analytical models are introduced in this thesis. The first one aims to forecast storage yard inventory by dealing explicitly with stochastic behavior, yard inventory peaks and seasonal fluctuations. The second one, which is based on probabilistic and statistical functions, is derived to estimate the average number of rehandles when containers with different departure probabilities are mixed in the same stack. Finally, the numerical experiments presented in this thesis prove the usefulness of the different analytical models, yard design methods, cost models and operative and tactical strategies developed herein. These can be applied by other researchers, planners and terminal operators to optimize the yard handling processes, to improve their efficiency rates and to increase terminal throughput without incurring large investment. By being technically efficient, the terminal will be more cost-efficient as well, resulting in the overall optimization of terminal performance.

This thesis develops mathematical programming models which integrate network design (ND) and line frequency setting (LFS) phases. These appear in transport planning studies that extend an existing urban public transportation system (UPTS) and are suitable for underground and rapid transit systems. The ND phase extends the working UPTS, taking as inputs the locations of candidate stretches and stations on the new lines, as well as construction costs which cannot exceed the available infrastructure budget. Regarding the LFS phase, frequencies and vehicles are assigned to functioning and newly built lines, providing that they do not exceed resource capacities and the time horizon. The developed models take into account the type of service patterns that may operate on the lines of the transport system. They include local services, where vehicles halt at every node in the line, and express services, in which vehicles halt at only a subset of nodes in the line. A passenger assignment model allows solving, simultaneously, the ND and LFS phases under a system optimum point of view. The combined model has two variants: one which deals with inelastic demand and another which faces elasticities in demand. The latter originates from changes in the modal choice proportions of travelers and may result from modifications in the public transport system. The former does not take into account competition among several modes of transportation and it is formulated as a mixed-integer linear programming problem. In contrast, the latter allows passengers to travel via two modes of transportation: public transport and private car. It is formulated as a mixed-integer linear bi-level programming problem (MILBP) with discrete variables only in the upper level. In both models, a complementary network is used to model transfers among lines and to reach the passenger¿s origin and/or destination nodes when the constructed UPTS does not cover them. The model with inelastic demand is initially solved by means of the commercial solver CPLEX under three different mathematical formulations for the ND phase. The first two are exact approaches based on extensions of Traveling Salesman Problem formulations for dynamic and static treatment of the line¿s subtours, whereas the last one is an approximation inspired by constrained k-shortest path algorithms. In order to deal with large-sized networks, a quasi-exact solution framework is employed. It consists of three solving blocks: the corridor generation algorithm (CGA), the line splitting algorithm (LSA), and a specialized Benders decomposition (SBD). The LSA and CGA are heuristic techniques that allow skipping some of the non-polynomial properties. They are related to the number of lines under construction and the number of feasible corridors that can be generated. As for the SBD, it is an exact method that splits the original mathematical programming problem into a series of resolutions, composed of two mathematical problems which are easier to solve. Regarding the elastic demand variant, it is solved under the same framework as the specialized Benders decomposition adaptation for solving MILBP, which results from this variant formulation. The inelastic demand variant is applied to two test cases based on underground network models for the cities of Seville and Santiago de Chile. Origin destination trip matrices and other parameters required by the models have been set to likely values using maps and published studies. The purpose of these networks is to test the models and algorithms on realistic scenarios, as well as to show their potentialities. Reported results show that the quasi-exact approach is comparable to approximate techniques in terms of performance. Regarding the elastic demand variant, the model is more complex and can be applied only to smaller networks. Finally, some further lines of research for both modeling and algorithmic issues are discussed.

El ferro-carril es el sistema urbano de transporte masivo de pasajeros por antonomasia. Es la infraestructura urbana de mayor coste y la de mayor repercusión en su entorno. Posee un poder de transformación del tejido urbano a medio y largo plazo y configura y refleja la historia, el crecimiento , la evolución y los avatares del sistema urbano sobre el que se asienta. La relación entre desarrollo urbano y desarrollo de la red ferro-viaria metropolitana es pareja y conforman un complejo puzzle donde se definen los centros neurálgicos y las periferias urbanas, los focos de gran dinamismo espacial, económico y social y las áreas relegadas al aislamiento. Prever los trazados del ferro-carril significa prever, a su vez, los cambios y transformaciones que se producirán sobre la superficie. La presente Tesis busca profundizar en la interacción existente entre la red ferro-viaria de un área urbana y sus repercusiones a nivel territorial, social y político. Otro de los objetivos es el de comprender los factores que conforman el espacio urbano y sus elementos existentes. En este sentido se pretende analizar el fenómeno de la sinergia existente entre la red ferro-viaria y el entramado urbano, para cuantificar la forma y cuantía en que ambos sistemas se retroalimentan. Hasta la fecha, los planes que decidían los trazados de las líneas y estaciones de los sistemas ferro-viarios se realizaban, fundamentalmente, por medio de parámetros técnicos, basándose en las áreas de producción y reproducción de las urbes a las que daba cobertura el sistema ferro-viario. Uno de los propósitos de esta tesis es ampliar el número de variables a considerar, a la hora de trazar una línea o red ferro-viaria, teniendo en cuenta parámetros de índole social y no únicamente consideraciones técnicas. El estudio de caso se centra en la ciudad de Barcelona. Hoy, Barcelona, es una ciudad en etapa de consolidación, la expansión descontrolada de la periferia está en claro retroceso y se comienzan a dibujar nuevos centros económicos y sociales en el espacio urbano consolidado. Dicha consolidación ha de pasar necesariamente por la vertebración con los sistemas de transporte. En este sentido, se advierte claramente la evolución que ha tenido el sistema ferro-viario barcelonés y su imbricación con el crecimiento urbano de la ciudad. El sistema ferro-viario barcelonés, en su etapa de madurez, ha transformado su estructura arborescente a una red propiamente dicha, una malla con interconexiones múltiples y con un centro amplio que abarca la práctica totalidad del continuo urbano. Con la finalización de las obras de ampliación de la red ferro-viaria de Barcelona se cerrará también un capítulo en la historia del urbanismo barcelonés. / This thesis seeks to deepen the interaction between the railway network in an urban area and their impact on territorial, social and political level. Another objective is understand the factors that shape the urban space and its existing elements. In this sense is analyzed the phenomenon of synergy between railway network and the urban area. To date, the plans that decided the lines and stations of the railways systems were realized mainly through technical parameters, based on the areas of production and reproduction of the cities. One purpose of this thesis is to expand the number of variables to consider, taking into account social parameters, not only technical considerations. The case of study focuses on the city of Barcelona. Today, Barcelona is a city in consolidation phase, the uncontrolled expansion of the periphery is in sharp decline and begin to appear new economic and social centers in the consolidated urban space. Such consolidation must necessarily pass through the articulation with transport systems. In this sense, the evolution that has taken the Barcelona railways system and its integration with the urban growth of the city is clearly seen. The railways of Barcelona has transformed its tree structure to an actual network, a mesh with multiple interconnections and a major center covering almost all the urban continuum. With the completion of the expansion of the railways of Barcelona it will close a chapter in the history of Barcelona urbanism.

La fase de transición se define como el proceso de cambiar de un plan de semaforización o de tiempos de semáforos a otro. Este proceso puede conducir a graves interrupciones en el flujo de tráfico provocando congestión y costos asociados con el tiempo adicional de viaje, el consumo de combustible y las emisiones de gases contaminantes a la atmosfera. Esta investigación propone el diseño de un modelo matemático no lineal para mejorar el rendimiento de la transición entre los planes de frecuencia de la señal en las intersecciones coordinadas. El modelo comprende la minimización de una función de costos sociales, que incluye una reducción en la demora, las emisiones de gases y el consumo de combustible, considerando múltiples objetivos que adoptan más medidas de efectividad. Para resolver el modelo matemático se diseña un algoritmo de colonia de hormigas que permite encontrar los parámetros óptimos de coordinación durante la fase de transición. Además la evaluación de la eficacia del nuevo modelo, su validez y utilidad se han comprobado mediante su aplicación en dos casos de estudios y un caso real para un corredor en la ciudad de Santander. Esta evaluación se realizó sobre la base de la capacidad del modelo para reducir al mínimo los retardos, las emisiones de contaminación del aire y el consumo de combustible. El modelo es eficiente en tanto que permite reducir los costos sociales asociados con el período de transición. / The transition phase is defined as the process of changing from one traffic-timing plan to another. This process may lead to serious disruptions in traffic flow causing congestion and extra costs associated with additional travel time, fuel consumption and emissions of polluting gases into the atmosphere. This research proposes the design of a nonlinear mathematical model to improve the performance of the transition between signal frequency plans in coordinated intersections. The model includes the minimization of a social cost function that incorporates a reduction in delay, gas emissions and fuel consumption, considering multiple objectives that adopt more effectiveness measures. To solve the mathematical model, an ant colony algorithm is designed to find the optimal coordination parameters during the transition phase. In addition, the new model effectiveness, its validity and usefulness have been proven through its application in two case studies and a real case of a traffic corridor in the city of Santander. This assessment was made based on the model's ability to minimize delays, emissions of air pollution and fuel consumption and its effectiveness in reducing the social costs associated with the transition period.

NUNES, C. S. Caracterização de fases e análise de trincas em junta soldada de Inconel 625 e aço 9Cr-1Mo após envelhecimento. 2006. 105 f. Dissertação (Mestrado em Ciência de Materiais) – Centro de Tecnologia, Universidade Federal do Ceará, Fortaleza, 2006. / Submitted by Marlene Sousa (mmarlene@ufc.br) on 2016-03-31T13:01:03Z No. of bitstreams: 1 2006_dis_csnunes.pdf: 11133016 bytes, checksum: 2052908ae018bb93d27596c930c78e76 (MD5) / Approved for entry into archive by Marlene Sousa(mmarlene@ufc.br) on 2016-03-31T17:59:22Z (GMT) No. of bitstreams: 1 2006_dis_csnunes.pdf: 11133016 bytes, checksum: 2052908ae018bb93d27596c930c78e76 (MD5) / Made available in DSpace on 2016-03-31T17:59:22Z (GMT). No. of bitstreams: 1 2006_dis_csnunes.pdf: 11133016 bytes, checksum: 2052908ae018bb93d27596c930c78e76 (MD5) Previous issue date: 2006-11-13 / The discoveries of new oil deposits with right rates acidity caused the refining units of crudes use facilities modified and adapted to this condition. In order to increase the corrosion resistance and reduce the risk of failure during the operation are used alloy steels of type Cr-Mo, A-213 T-9 (9%Cr e 1%Mo) in the tubes in refining plants configuring tubes ASTM A335 GR P 9, as API RP-530, designed for continuous service in media containing sulfide and high temperature. These tubes are coated with aluminum and welded by TIG welding process, with the root password nickel alloy, Inconel 625, welding rod ER-NiCrMo-3 and fill electrode E 505. Thus, it studied the behavior of nickel alloy deposited on the union of the tubes, their properties and has been the characterization of phases present in the material after aging. For this, we used samples from 02 tubes A-213 T-9 coated with aluminum and welded together under the same conditions of the tubes of the furnaces of the units of petroleum refining. The samples were exposed to temperatures in the range of operation (500 º C to 700 º C) for periods of 10h, 100h, 500h e 1000h. / As descobertas de novas jazidas de petróleo com índices de acidez cada vez maiores fizeram com que as unidades de refino de óleos crus utilizassem instalações modificadas e adaptadas para essa condição. Visando aumentar a resistência à corrosão e a reduzir o risco de falha durante a operação são empregados os aços liga do tipo Cr-Mo, A-213 T-9 (9%Cr e 1%Mo) nos tubos de fornos nas usinas de refino configurando os tubos ASTM A335 GR P 9, conforme API RP-530, projetados para serviço contínuo em meios contendo sulfeto e elevada temperatura. Esses tubos são revestidos internamente com alumínio e soldados através do processo de soldagem TIG, tendo como passe raiz liga de níquel, Inconel 625, vareta ER-NiCrMo-3 e preenchimento com eletrodo E 505. Dessa forma, estudou-se o comportamento da liga de níquel depositada na união dos tubos, suas propriedades e realizou-se a caracterização de fases presentes no material após o envelhecimento. Para isto, utilizou-se amostras de 02 tubos A-213 T-9 revestidos com alumínio e unidos por solda nas mesmas condições dos tubos dos fornos das unidades de refino de petróleo. As amostras foram expostas as temperaturas no intervalo de operação (500ºC à 700ºC) por períodos de 10h, 100h, 500h e 1000h.

As curvas de polarização potenciodinâmicas cíclicas da liga de níquel Inconel 625, em solução de NaCl 3,56 %, pH 7,5, desaerada e a temperatura ambiente, obtidas com base na metodologia descrita na norma ASTM G61, foram estudadas com o objetivo de interpretá-las, especialmente no trecho após a reversão da polarização. Para esse estudo, foram realizadas análises complementares por MEV/EDS e por espctroscopia Raman da superfície do eletrodo de trabalho e determinação qualitativa por EDS da composição do eletrólito coletado nas vizinhas do eletrodo de trabalho. Medidas de pH e determinação do teor de O2 do eletrólito junto ao eletrodo de trabalho também foram feitas. Os resultados obtidos mostraram que, entre o potencial de circuito aberto até potencial de quebra (Eb), da ordem de 0,600 V (ECS), a curva de polarização apresenta um comportamento passivo com tendência a atingir a densidade de corrente da ordem de 10-6 A/cm². Nessa região, ocorre o espessamento da camada devido à formação principalmente de Cr2O3. Após Eb, ocorre a mudança na inclinação da curva, devido à ocorrência da reação de oxidação da água, comprovada pela acidificação do eletrólito. No potencial de 0,750 V (ECS) ocorre uma inflexão na curva, causando a diminuição discreta da corrente, atribuída à formação de MoO42- (gel) que evita a incorporação de ânions como Cl- ou OH-, dificultando, porém não evitando, a oxidação/dissolução da camada passiva, comprovada pela presença de íons de Cr e de Ni no eletrólito, caracterizando uma região transpassiva. Após a reversão da polarização no potencial de 1,130 V (ECS), a curva apresenta uma histerese positiva, com valores de densidades de correntes menores em relação ao mesmo potencial aplicado durante a polarização direta, indicando a ocorrência de repassivação devido principalmente à formação de uma camada rica em Mo sobre a liga, cuja formação pode ser atribuída à transformação do molibdato para o óxido MoO3 decorrente da forte acidificação do eletrólito verificado nesse trecho da curva. Ainda, após a inversão da polarização, ocorre a transição da corrente anódica para catódica em um potencial próximo de 0,720 V (ECS). Do potencial de 0,600 V (ECS) até 0,200 V (ECS), observa-se uma região de passivação secundária, atribuída à formação do MoO3 de maneira mais significativa. Ao final a densidade de corrente volta a aumentar, indicando o início da oxidação/dissolução do MoO3 para Mo3+. / Cyclic potentiodynamic polarization curves of the nickel alloy Inconel 625 in 3.56 % NaCl solution, pH 7.5, deaerated and at ambient temperature, obtained according to the ASTM G61, were studied in order to interpret them, especially after the reversion of the scanning direction. For this study, complementary analyzes by MEV/EDS and by Raman spectroscopy of the working electrode surfaces as well as EDS analyses of the electrolyte collected near the working electrode were carried out. The pH values and O2 content of the electrolyte near the working electrode were also obtained. From the open circuit potential (OPC) up to breakdown potential (Eb), at about 0,600 V (ECS), the polarization curve presents a passive behavior with a tendency to reach the current density of 10-6 A/cm². In this region, the thickening of the passive film takes place mainly due to the formation of Cr2O3. After Eb, a change of the curve slope occurs due to the oxygen evolution reaction which is confirmed by the acidification of the electrolyte. At the 0,750 V (ECS) potential, an inflection of the curve is observed causing a discrete decrease in the current which was attributed to the formation of MoO42- (gel) which, in turn, avoids the incorporation of anions as Cl- or OH- in the passive film. This fact makes the oxidation/dissolution of the passive film difficult but does not avoid it since Cr and Ni ions were detected in the electrolyte after the inflection, characterizing a transpassive region. After the reversion of the scanning direction at the potential 1,130 V (ECS), the curve shows a positive hysteresis with lower current densities than the values obtained at the same potential applied during the direct polarization. This indicates the occurrence of repassivation mainly due to the formation of a Mo rich layer on the alloy whose formation can be attributed to the transformation of the molybdate to the MoO3 because of the strong acidification of the electrolyte. After the reversion of the polarization, a transition from the anodic current to cathodic occurs at a potential close to 0,720 V (ECS). From the potential of 0,600 V (ECS) up to 0,200 V (ECS), a secondary passivation region is observed which was attributed to the significant formation of MoO3. At the end of the reverse polarization, the current increases again, indicating the initiation of the oxidation/dissolution of MoO3 to Mo3+.

As recentes descobertas de reservas de petróleo no pré-sal, representam uma grande oportunidade e desafio para a Petrobrás e demais indústrias de exploração e extração do petróleo. As exigências quanto aos materiais mais resistentes à corrosão e que conciliam boa resistência mecânica são cada vez maiores, devido aos constantes esforços dinâmicos que os equipamentos estarão sujeitos, pois os componentes estruturais serão submetidos à grande lâmina de água, ocorrência que as companhias exploradoras terão que superar. A otimização de materiais e equipamentos que podem melhorar a performance nas explorações do pré-sal tem sido a grande busca do setor nos últimos anos, muitos deles precisam ser testados e atestados quanto sua resistência à propagação de trincas, uma vez que, serão submetidos a oscilações devido as movimentações das marés e as condições de alta severidade a que serão expostos. Para suportar as condições de exposições com H2S, resistência a corrosão por pitting e resistência mecânica, porcas e parafusos têm sido fabricados com o Inconel 625, essas peças são estruturais e de extrema importância para a prospecção do petróleo. Após todas as etapas de fabricação, conformação, tratamento térmico e laminação a frio, o material foi caracterizado, realizou-se ensaio de metalografia que apresentou tamanhos de grão 7 e 8 conforme norma ASTM E112. Uma das premissas para a realização desse trabalho está nas condições que o material será exposto em situações acidentais, conforme informações da própria Petrobrás, em caso de vazamentos, os do tipo estruturais podem ser submetidos a temperaturas criogênicas de -100°C, -120°C e até -190°C devido ao vazamento de gases. Assim, o material foi caracterizado em temperaturas criogênicas através dos ensaios de tração, impacto e de CTOD. No ensaio de tração foi observado para as diferentes temperaturas criogênicas que apesar do aumento na resistência do material, da ordem de 787 MPa, o Inconel 625 manteve um alongamento acima de 40%. Nos resultados de Impacto a tenacidade se manteve acima de 200 J e não foi notada a curva de transição dúctil-frágil, mesmo para temperaturas tão baixas. No ensaio de CTOD utilizou-se corpos de prova de flexão (SENB) no ensaio de tenacidade à fratura, de acordo com a norma ASTM E1290.A componente plástica da abertura da boca do entalhe na temperatura de -190°C, pior caso, se manteve em 1,52 mm em média. Mediante a todos os resultados obtidos, pode-se afirmar que o aumento da resistência do Inconel 625 pelo processo de encruamento, não impossibilita sua aplicação para temperaturas criogênicas, mantendo sua capacidade de se deformar apreciavelmente antes de se romper. / Recently oil and gas discoveries in the Pre-Salt layer represent a huge exploration potential in Brazil, however, the technological challenges for the exploitation of these mineral resources are immense and therefore have motivated the development of studies looking for efficient methods and materials for their productions. The requirements about materials more corrosion resistance and mechanical resistance have been more frequently, as a result of high deep layer to explore the petroleum. The materials and equipment optimization to improve the performance in the pre-salt exploration have been the big search for oil and gas companies in the last years, but this materials must be testing in the crack propagation, because, this materials must resistance by oscillations, as consequence of ocean movements and others difficult situations that the materials must be support. To support H2S conditions, corrosion resistance by pitting corrosion and high mechanical resistance, bolts and nuts have been manufactured with Inconel 625, these products are structural and they are extreme importance to petroleum exploration. After all manufacturing operations, hot worked heat treatment and cold worked, the material was studied, and it was realized micrographic testing that result in grain size 7 and 8, in accordance ASTM E112 standard. One of premise to realized this paper are in the conditions that the material will be supported in accident situations, in agreement of Petrobras information, in the gases scape accidents, the structure materials can be exposed in cryogenically temperatures of -100°C, -120°C until -190°C. Therefore, the material was studied in cryogenically temperatures throw tensile testing, impact testing and CTOD. In the tensile testing was noted to different kind of cryogenically temperatures, same with more mechanical resistance, 787 MPa yield strength, the Inconel 625 has kept the 40% elongation. In the impact testing the notch toughness as kept above 200 J and it was not seen the transition ductile-Brittle in the low temperatures. In the CTOD testing was used bending test specimens (SENB) in the fracture toughness test for the Inconel 625, in agreement with the ASTM E1290 standard. The specimens was testing in tension and CTOD test in low temperatures: -100°C, -120°C and -190°C.The Clip gage displacement was recorded in the -190°C temperature with 1,52 mm average, this is the worse situation. Analyzing all the results, can be considered that the growth mechanical resistance of Inconel 625 by cold worked process, allow your application with cryogenically situations and the material has kept your ability to be well deformed before the crack.