The Wiener index of a graph G is defined as the sum of the distances between all pairs of vertices in G. In this master thesis we introduce recursive trees, plane oriented recursive trees (PORTs) and simply generated trees. We then present results by Neininger, Janson, and Munsonius and Rüschendorf for the expectation and limiting distribution of the Wiener index of these families. For recursive trees and PORTs the results follow from analysing the recursive structure of the trees and the contraction method, while the results for simply generated trees is based on a limiting object, the continuum random tree.

E-bikes, often known as electric bicycles, are becoming more and more well-liked as green modes of mobility. High-capacity lithium-ion (Li-ion) batteries are utilised to power these e-bikes because of their extended cycle life, high energy density, and low self-discharge rate. The performance and longevity of these batteries may be impacted by temperature fluctuations, however. To guarantee the safe and dependable functioning of Li-ion batteries used in e-bikes, it is crucial to do temperature analysis on the batteries. In this dissertation, the thermal behaviour of a 48V 60AH Li-ion battery used in an e-bike will be studied under various cooling scenarios. The research specifically contrasts forced convection cooling using fans with broad and limited outlet ports to natural air convection cooling with large and reduced outlet ports. The study sheds light on the ideal cooling setups that might increase battery longevity and performance. The results of this study have important ramifications for e-bike producers and designers, battery producers, and energy storage system researchers. Simulations based on computational fluid dynamics (CFD) are used to simulate the thermal behaviour of the Li-ion battery under various cooling settings for the investigation. 25°C has been selected as the ambient temperature. For forced convection, the airflow rate is set at 3.5 m/s, whereas the airflow rate for natural convection is set at 0.1 m/s. The study's findings demonstrate that both natural and forced convection cooling methods may successfully lower the temperature of a Li-ion battery. However, forced air convection cooling using fans is more efficient than natural air convection at dispersing heat. These findings suggest that, owing to the higher air velocity, shrinking the outlet ports in both cooling approaches improves thermal performance.

This research attempts to evaluate temporary urban regeneration potential by integrating two systems that make up an interim intervention which addresses an observed problem. The research proposes a systematic approach for a multi-system life cycle assessment model which lays out the process of working with two separate systems to provide a pathway for temporary urban development strategies. To achieve this, the research starts with identifying parameters of temporary urban regeneration through a systematic review of the literature. Key parameters are categorized based on objectives, indicators, as well as, physical characteristics of the literature explored case studies. Then, the findings are utilized to guide the proposed model of connecting two given systems to assess their joint impacts on a temporary urban regeneration system. The proposed MSLCA framework utilizes a holistic modeling structure with a process to integrate and analyze separate systems and quantify results for overall sustainability performance. Finally, the model is used to evaluate a case study involving two systems that address observed problems and provide urban services. The results explore the environmental impacts of the proposed intervention and highlight the effects of individual components on both systems. Through the implementation of the model, decisions on temporary urban intervention are guided by hotspots in the results. The findings reveal an opportunity for future research to expand the model's application to other processes and further its scope beyond environmental indicators. Subsequent studies can investigate opportunities for a holistic approach that includes economic and social aspects. / Doctor of Philosophy / The way we live in cities is heavily influenced by how they are planned. Improvident city planning could deny residents opportunities to enjoy some basic urban amenities. These problems could be self-induced as they are often a result of planning, policies, or personal habits and choice. Planners, urban designers, and regulators are constantly experimenting with different tools of urban regeneration to rediscover genuine urban experiences. This research sets out to investigate opportunities for temporary urban interventions on vacant lands in the city of Riyadh through repurposing idle shipping containers as a tool. This is to address the issues of a lack of urban services within residential subdivisions in the city, the high prevalence of vacant lands, and a wide availability of decommissioned shipping containers. The use of shipping containers for non-cargo purposes has seen an increased interest among architects and designers for their versatility and accessibility. Empty container accumulation is often a result of an unbalanced trading system which is mainly an issue of import-based countries. Therefore, the upcycling potential of intermodal containers can extend their life cycles and take advantage of their structure. It also maximizes the environmental returns of their raw materials. Through such processes of circular economy, potential waste objects can be repurposed as resources into usable structures and thus avoids the use and extraction of new raw materials. It is generally thought that the repurposing of shipping containers into building structures introduces environmental advantages when compared to traditional construction. Similarly, vacant lands are a valuable and well-established resource that can provide the setting for temporary urban interventions. Finding a joint productive use of these systems is at the center of this research as it attempts to assess the urban regeneration value of their merged utility during their idle stage. This helps address a key challenge that most urban area suffers from which is the lack of easily accessible and timely deployable temporary urban intervention to serve a particular use. This research aims to create a model that evaluates the lifecycles of temporary uses based on the joint intersection of contributing systems. The proposed Multi-System Life Cycle Assessment (MSLCA) model is to be applied to assess temporary urban regeneration interventions and help make decisions regarding appropriate approaches. The goal of the model is to propose a value-based approach based on characteristics from two systems. The resulting MSLCA model answers questions on how to apply LCA processes to a transitional intervention with new processes. In doing so, it highlights parameters for systems integration and processes for planning appropriate scenarios for urban interventions. It also highlights the need for unique system boundaries and specifies approaches for system assessment and interpretation. Finally, it provides broader impact categories beyond environmental impacts to consider specific economic and social indicators.

This thesis examines the pivotal role of port infrastructure in supporting offshore wind project development, with a focus on the strategic significance of port operation and storage. This study addresses the challenges of evaluating port area demand, complicated by the intricate and dynamic nature of the construction and logistical operations associated with offshore wind development. Through a comprehensive approach that includes a literature review on diverse roles of ports, analysis of port operations for key turbine components, and formulation of an assessment model to estimate port area demand, this research offers insights into the logistical and operational needs of ports in the offshore wind sector. A significant highlight of this study is the consideration of the temporal influence on port demand, a crucial factor stemming from the continuous loading and unloading activities at the port. In addition to port terminal area, hard criteria such as water depth, quay length, and load-bearing capacity are also examined. The findings underscore the connection between port infrastructure and the efficient operation of offshore wind farms. It highlights the need for synchronized coordination between the transport rate of components and offshore installation activities, to meet the specific demands of port infrastructure. Furthermore, the thesis explores these findings in the context of port development, identifying key requirements, challenges, and opportunities within the sector and offering a forward-looking perspective on the industry. This perspective considers the emerging trends, technological advancements, and innovative practices in offshore wind and their implications for port development. In conclusion, the research emphasizes the critical importance of understanding and meeting port specification requirements for the successful execution of offshore wind projects. It calls for continuous research and development efforts to improve the accuracy of estimating port infrastructure enhancement needs, in support of the growing offshore wind industry.

"Ça s'est passé à la taverne de l'hôtel Plaza, à deux pas des installations portuaires de la compagnie Alcan, à Port-Alfred. Chaque jour de la semaine, ils se retrouvaient en aprèsmidi autour de la même table : barbier à la retraite, chauffeur de taxi à la grande gueule, manoeuvre au port et prostituée vieillissante. Ça parlait de marée, marins, clients d'exception et voyages longue distance. Ça se racontait des histoires pas toujours catholiques. Enregistrées à leur insu par un étudiant rattaché au GRAMUL, les histoires de cet étrange quatuor intriguent un autre étudiant, Etienne, qui met la main dessus. Celui-ci est à ce point touché par ces personnages qu'il décide de faire une pause dans la rédaction de sa thèse en muséologie afin d'écrire un roman basé sur ces documents. Ça s'intitulera Port- Alfred Plaza, et Etienne ira écrire sur place son premier roman. Dans ce lieu de transit, il fera la connaissance de Johanna, une femme de ménage dotée d'un étonnant sens des affaires." / "Dans le roman Port-Alfred Plaza, la ville portuaire impose sa présence pour devenir un véritable personnage. Dans la réflexion intitulée Port-Alfred evermore, cette même ville se transformera en espace propice à l'introspection. D'une approche résolument thématique, cette réflexion sur la présence de la ville portuaire en littérature prendra la forme d'un journal intime. Cinéaste apatride retrouvant après quarante ans d'absence les rues et les ruelles de son enfance, Laurence Kennedy prendra plaisir à se mouler au plan orthogonal de la petite ville portuaire. Vers la fin de son séjour, il rencontrera dans le parc un jeune homme venu écrire ici son premier roman, et le jour suivant, à la taverne, un certain barbier à la retraite. Son journal de déambulation aura cette particularité d'être émaillé d'extraits de textes. Ceux de Femand Dumont et d'Alain Médam deviendront autant d'amorces à la réflexion, et les extraits de quelques écrivains ayant décrit la réalité portuaire viendront cristalliser les souvenirs d'une enfance lumineuse passée dans un petit port en Amérique."

Based on literature review, statistics of waste management at ports in South Africa is hard to come by. The research critically assessed the current waste management practices at Transnet National Ports Authority. Transnet National Ports Authority, Port of Richards Bay (TNPA RCB) was used as a case study to examine the different types and quantities of waste produced, analysing the current waste management model as well as determining TNPA RCB compliance to pertinent waste legislation. A 10 day waste audit was conducted to obtain quantitative data and to identify the different types of waste generated. The baseline data resulting from the waste audit conducted for the first time since the establishment of the TNPA RCB, found 402 kg of general waste generated, 74 kg of this total is segregated for recycling and the remaining 328 kg is landfilled. The overall conclusion gained during compliance audit was that the TNPA RCB was partly compliant with pertinent waste legislation and obligations. Furthermore, questionnaires about waste were sent to staff members working in offices to get an overview of how they deal with current waste management. A number of barriers to sustainable waste management were identified, including: lack of knowledge and awareness; constraints on facilities and human resources; culture that resists change and contamination. To overcome these, there needs to be education, as well as co-operation between top management, staff and waste service providers to help implement new strategies. The primary conclusions from this dissertation are that there are opportunities to divert waste streams from landfill and to attain a sustainable waste management system at TNPA RCB. / Environmental Sciences / M. Sc. (Environmental Management)

La thèse aborde une question originale et d'actualité: l'extension artificielle des côtes. Afin de mieux comprendre ce phénomène dans son actualité, la thèse attache une importance à la description de la pratique des États en fournissant les informations aussi précises, aussi actuelles et aussi concrètes que possible. C'est à partir de cette pratique que la thèse répond à la question de savoir comment les règles de droit répondent aux exigences de la pratique. En ce qui concerne la pratique des États, la thèse explique, dans une première partie, que l'extension artificielle des côtes est destinée, tantôt, à protéger les côtes contre l'élévation du niveau de la mer, tantôt à gagner des terres pour diverses fins: habitat humain, agricoles, développement des ports et de leurs infrastructures pour les besoins des navires modernes et du commerce international. Mais parallèlement, cette extension entraîne des effets négatifs pour l'écosystème côtier (chapitre I). Des travaux de ce genre ont été menés, ou vont l'être, en Europe (Pays-Bas, Allemagne, Belgique, France, R.-U., etc), aux États-Unis, en Asie (Bahreïn, Malaisie, Hong Kong, Singapour, Japon), en Australie, et sur certains archipels du Pacifique (chapitre II). La seconde partie de la thèse examine le droit applicable au phénomène d'extension artificielle des côtes. Sont ainsi passées en revue: les règles relatives à la navigation (chapitre III), les règles relatives aux lignes de base (chapitre IV), les règles relatives aux hauts-fonds découvrants (chapitre V), les règles relatives aux îles et aux rochers (chapitre VI) et enfin les règles relatives à la protection de l'environnement marin (chapitre VII).

The port site of Berenike Troglodytica - located on the Egyptian Red Sea coast - served the spice and incense routes that linked the Mediterranean World (specifically the Roman Empire) to India, Southern Arabia and East Africa. In the Greco-Roman period the site was at the cutting edge of what was then the embryonic global economy, ideally situated as a key node connecting Indian Ocean and Mediterranean trade for almost 800 years. It is now located in an arid, marginal, hostile environment but the situation must have been very different 2300 years ago, at the time of its founding. At the time of elephant-hunting trips during the Hellenistic period before the inception of its important role in the global markets of the day in the Roman period Berenike would have to have looked much different to what we can now imagine. What was it like then, when the first prospectors visited this location at the time of Ptolemy II? Why this particular place, and this particular landscape setting seemed such a propitious location for the siting of an important new harbour? Given the importance of the port over almost a millennium it is perhaps surprising that very little is known about the different factors impacting on the foundation, evolution, heyday and subsequent decline of the city; or the size, shape, and capacity of its harbour. The intention of this research is to address this shortfall in our knowledge, to examine the drivers behind the rise and fall of this port city, and to explore the extent to which the dynamics of the physical landscape were integral to this story. Using an innovative Earth Science approach, changes in the archaeological 'coastscape' have been reconstructed and correlated with periods of occupation and abandonment of the port, shedding light on the nature, degree and directionality of human-environment interactions at the site. This work has revealed profound changes in the configuration of the coastal landscape and environment (including the sea level) during the lifespan of Berenike, highlighting the ability of people to exploit changes in their immediate environment, and demonstrating that, ultimately, the decline of the port was partly due to these landscape dynamics. To further explore these themes the landscape reconstructions have been supplemented by semi-quantitative analyses of a suite of variables likely to influence the initial siting of new ports of trade. These have shown that although the site of Berenike was ideal in terms of its coastal landscape potential, possessing a natural sheltered bay and lagoon system, the choice of location was not solely influenced by its environmental conditions. Additionally, a detailed review of vessels that plied Red Sea and Indian Ocean routes is presented here in order to better understand the design and functioning of Berenike's harbour. This serves the purpose of identifying unifying features that provide more detail about the size and draught of vessels and the potential capacity of the harbour basin. By using this multi-scalar approach it has been possible to reconstruct the 'coastscape' of the site through the key periods of its occupancy and those phases immediately before and after its operation. This has wide-ranging implications for researchers studying ancient ports along this trade network as a larger database will tease out more details about how influential the landscape was in the initial siting of the port and its subsequent use and decline.

Based on literature review, statistics of waste management at ports in South Africa is hard to come by. The research critically assessed the current waste management practices at Transnet National Ports Authority. Transnet National Ports Authority, Port of Richards Bay (TNPA RCB) was used as a case study to examine the different types and quantities of waste produced, analysing the current waste management model as well as determining TNPA RCB compliance to pertinent waste legislation. A 10 day waste audit was conducted to obtain quantitative data and to identify the different types of waste generated. The baseline data resulting from the waste audit conducted for the first time since the establishment of the TNPA RCB, found 402 kg of general waste generated, 74 kg of this total is segregated for recycling and the remaining 328 kg is landfilled. The overall conclusion gained during compliance audit was that the TNPA RCB was partly compliant with pertinent waste legislation and obligations. Furthermore, questionnaires about waste were sent to staff members working in offices to get an overview of how they deal with current waste management. A number of barriers to sustainable waste management were identified, including: lack of knowledge and awareness; constraints on facilities and human resources; culture that resists change and contamination. To overcome these, there needs to be education, as well as co-operation between top management, staff and waste service providers to help implement new strategies. The primary conclusions from this dissertation are that there are opportunities to divert waste streams from landfill and to attain a sustainable waste management system at TNPA RCB. / Environmental Sciences / M. Sc. (Environmental Management)

Titre de la Thèse : L'établissement des chemins de fer dans les Balkans à l'époque ottomane : structuration de l'espace et organisation des échanges (1856-1913)Rejoindre l'Orient, voici sans doute l'une des obsessions de l'Occident. Peut-être l'épopée d'Alexandre le Grand a t-elle contribué à construire cet objectif quasi mystique. Quoi qu'il en soit, le XIXe siècle est celui de sa rationalisation. L'invention de la locomotive et celle du navire à vapeur permettent d'amorcer un processus de mise en réseau du monde. Sur les cinq continents, les villages, les villes et les ports s'interconnectent progressivement, engendrant une mondialisation des flux commerciaux et humains. Ce mouvement est orchestré par les grandes puissances européennes, dont le pouvoir est fondé sur la conquête de nouveaux marchés et sur l'importation des matières premières essentielles à leur essor. Londres et Bombay forment alors deux pivots incontournables, permettant de rediriger les flux en circulation à l'échelle trans-continentale. Entre ces deux points, Suez joue le rôle d'interface entre la mer Rouge et la Méditerranée. Au cours de la seconde moitié du XIXe siècle, l'espace balkanique est progressivement intégré à ce système-monde. L'introduction du rail y induit une profonde redéfinition des rapports de force, que ceux-ci soient d'ordre économique, militaire ou politique. A ce titre, la mise en place de voies ferrées dans les Balkans, à l'époque sous domination de l'Empire ottoman, résulte d'une imbrication de stratégies d'influence, s'exprimant à différentes échelles. Cette thèse se propose de les mettre en lumière. / Reaching the East : this is undoubtedly one of the obsessions of the West. Maybe Alexander the Great's conquests contributed to forge this quasi-mystical aim. Wherever it comes from, the XIXth century is the one of its rationalization. Inventions such as steam locomotive and steamship allow to begin a global networking process. On five continents, villages, cities and ports, are progressively interconnected, generating a globalization of human and trade flows. This movement is orchestrated by the major European powers, whose expansion is based on the conquest of new markets and on the importation of natural resources required for their development. London and Mumbay play at that time a pivotal role, allowing to reroute flows in circulation at the inter-continental scale. Between these two major cities, Suez is an unavoidable crossing point between the Mediterranean and the Red Sea. During the second half of the XIXth century, the Balkan space is progressively integrated to this world-system. In that region, the introduction of railway induces a radical restructuring of power relations, whether political, economical or military. For this reason, the establishment of railways in the Balkans results from an interlacing of influencing strategies, articulated at various scales. This thesis sets out to highlight them.