Market prices in the liberalized European electricity system play a crucial role in promoting competition, ensuring grid stability, and maximizing profits for market participants. Accurate electricity price forecasting algorithms have, therefore, become increasingly important in this competitive market. However, existing evaluations of forecasting models primarily focus on overall accuracy, overlooking the underlying causality of the predictions. The thesis explores two state-of-the-art forecasters, the deep neural network (DNN) and the Lasso Estimated AutoRegressive (LEAR) models, in the EPEX-BE and Nord Pool markets. The aim is to understand if their predictions can be trusted in more general settings than the limited context they are trained in. If the models produce poor predictions in extreme conditions or if their predictions are inconsistent with reality, they cannot be relied upon in the real world where these forecasts are used in downstream decision-making activities. The results show that for the EPEX-BE market, the DNN model outperforms the LEAR model in terms of overall accuracy. However, the LEAR model performs better in predicting negative prices, while the DNN model performs better in predicting price spikes. For the Nord Pool market, a simpler DNN model is more accurate for price forecasting. In both markets, the models exhibit behaviours inconsistent with reality, making it challenging to trust the models’ predictions. Overall, the study highlights the importance of understanding the underlying causality of forecasting models and the limitations of relying solely on overall accuracy metrics. / Priserna på den liberaliserade europeiska elmarknaden spelar en avgörande roll för att främja konkurrens, säkerställa stabilitet i elnätet och maximera aktörernas vinster. Exakta prisprognoalgoritmer har därför blivit allt viktigare på denna konkurrensutsatta marknad. Existerande utvärderingar av prognosverktyg fokuserar emellertid på den övergripande noggrannheten och förbiser de underliggande orsakssambanden i prognoserna. Denna rapport utforskar två moderna prognosverktyg, DNN (Deep Neural Network) och LEAR (Lasso Estimated AutoRegressive) på elmarknaderna i Belgien respektive Norden. Målsättningen är att förstå om deras prognoser är pålitliga i mer allmänna sammanhang än det begränsade sammahang som de är tränade i. Om modellerna producerar dåliga prognoser under extrema förhållanden eller om deras prognoser inte överensstämmer med verkligheten så kan man inte förlita sig på dem i den verkliga världen, där prognoserna ligger till grund för beslutsfattande aktiviteter. Resultaten för Belgien visar att DNN-modellen överträffar LEAR-modellen när det gäller övergripande noggrannhet. LEAR-modellen presterar dock bättre när det gäller att förutse negativa priser, medan DNN-modellen presterar bättre när det gäller prisspikar. På den nordiska elmarknaden är en enklare DNN-modell mer noggrann för prisprognoser. På båda marknaden visar modellerna beteenden som inte överensstämmer med verkligheten, vilket gör det utmanande att lita på modellernas prognoser. Sammantaget belyser studien vikten av att förstå de underliggande orsakssambanden i prognosmodellerna och begränsningarna med att enbart förlita sig på övergripande mått på noggrannhet.

Master of Science / Department of Mechanical and Nuclear Engineering / Donald L. Fenton / Increase in demand for energy necessitates nuclear power units to increase their peak power limits. This increase implies significant changes in the design of the nuclear power unit core in order to provide better economy and safety in operations. A major hindrance to the increase of nuclear reactor performance especially in Pressurized Water Reactors (PWR) is the so called ‘Axial Offset Anomaly (AOA)’. An Axial Offset Anomaly (AOA) is the unexpected change in the core axial power distribution during the operation of a PWR from the predicted distribution. This problem is thought to be occurring because of precipitation and deposition of lithiated compounds such as lithium metaborate (LiBO[subscript]2) on the fuel rod. Due to its intrinsic property, the deposited boron absorbs neutrons thereby affecting the total power distribution in the reactor. AOA is thought to occur when there is sufficient build up of crud deposits on the cladding during subcooled nucleate boiling. Predicting AOA is difficult because there is little information regarding the heat and mass transfer during subcooled nucleate boiling. This thesis describes the experimental investigation that was conducted to study the heat transfer characteristics during subcooled nucleate boiling at prototypical PWR conditions. Pool boiling tests were conducted with varying concentrations of LiBO[subscript]2 and boric acid (H[subscript]2BO[subscript]3) solutions along with deionized water. The experimental data collected includes the effect of coolant concentration, degree of subcooling, system pressure and heat flux on pool boiling heat transfer coefficients. An analysis of deposits formed on the fuel rod during subcooled nucleate boiling is also included in the thesis. The experimental results reveal that the pool boiling heat transfer coefficient is degraded by the presence of boric acid and lithium metaborate in water. At concentration of 5000 ppm in water, the boric acid solution reduced the heat transfer coefficient by 23% and lithium metaborate solution reduced the heat transfer coefficient by 26%.

One of the biggest questions surrounding common-pool natural resources (CPRs) lies in understanding the circumstances which increase the likelihood of sustainable use and those that lead to resource degradation. Small-scale fisheries are an example of a CPR that has proven difficult to manage sustainably. I use social network analysis methods to examine the social connectivity of small-scale fishing communities and the association of network structures with collaborative behavior of small-scale fisheries in the Northern Gulf of California, Mexico.I found considerable connectivity of communities via kinship ties of small-scale fishers, both within the region and to other areas in Mexico. Fisher kinship relationships are important mechanisms for information transfer. Identifying communities in the network that are most likely to share information with other communities allows managers to develop more effective and efficient education, outreach, and enforcement efforts.Communities are also connected by their use of the same fishing zones and Marine Protected Areas (MPAs). My results provide suggestions for dividing communities based on common use of fishing areas and MPAs. This may help fishers and managers to develop, implement, and enforce boundary rules that will facilitate regional management of small-scale fisheries. My results provided mixed evidence for the role of social structure in impacting positive outcomes for fisher' ability to collaborate and organize. A wide range of factors affect the emergence of institutions for CPR management. Similarly, finding a common network structure that can accurately predict sustainable use of CPRs is unlikely. Knowing how people are connected and the ways in which information about CPR resources moves through (or is hindered from moving through) a network can improve manager's ability to develop more effective strategies and actions. Adding social networks into the CPR management toolbox provides a mechanism by which those working in management and conservation can incorporate social structure into management activities.An understanding of the social networks that connect communities and the potential pathways for information transfer, combined with a system of enforceable rules and policies and effective outreach methods and materials, may help managers and resource users more effectively and sustainably manage CPRs in the long term.

In recent years, a number of high profile accidental fires have occurred in several road and rail tunnels throughout the world. Many of these fires grew rapidly to catastrophic size and claimed many lives. The processes involved in the rapid growth and extremely severe of these fires are not adequately understood as yet. The introduction to this thesis reviews a number of these accidental fires and describes much of the previous experimental research which has brought about the current understanding of tunnel fire behaviour. A detailed review of the relevant parts of elementary fire dynamics is also presented. This thesis addresses two main questions: 1. What is the influence of longitudinal ventilation on fire size in tunnels? and 2. What is the influence of tunnel geometry on fire size? The answers to both these questions are determined using a probabilistic method called Bayes Theorem. This provides a method of answering the above two questions using the handful of experimental data which are available. It is found that the heat release rate (HRR) of a heavy goods vehicle (HGV) fire may be greatly increased in magnitude by longitudinal ventilation, for example by about a factor of 5 with a longitudinal ventilation velocity of 3ms-1. It is also found that longitudinal ventilation may cause a significant increase in the HRR of large pool fires, but may cause a decrease in the HRR of small pool fires and car fires. An equation is derived to predict the influence of tunnel geometry on HRR. It is found that HRR varies principally with the width of the tunnel and the width of the fire object. The HRR of a fire in a tunnel my be increased up to four times due to the geometry of the tunnel.

The research was carried out using a participatory action research approach to develop social accounts with Jesmond Swimming Pool (JSP). The original motivation to carry out this project was to see what social accounts would look like and whether it was possible to develop them in this organisation. The experience of doing social accounts is further examined using Gray, et al., (1997) to explore whether these were either ‘ideal’ or ‘good’ social accounts for the organisation. A communitarian philosophical framework is used in order to examine the conceptualisation of ‘good’ social accounts. The first part of the thesis explores the social and environmental accounting (SEA) and accountability literature, with the second part exploring the experience of reaching initial agreement to do social accounts (SAs). The agreement to do the accounts was then followed by two years of social accounts developed with JSP. This empirical data provides a detailed account from the perspectives of insiders and other sources as to the experience of doing social accounts. This experience is then opened up to interrogation from a wider view point. The third part of the thesis examines the experience of JSP using third sector communitarian philosophy and a voluntary accountability framework in order to demonstrate that JSP could provide an example of a ‘good’ or ‘ideal’ social account. This raises the issue of whether or not ‘good’ or ‘ideal’ social accounts for third sector organisations are only possible within a communitarian paradigm. If it is possible to establish what ‘good’ social accounts entail then it may be appropriate to extend this approach to other contexts, for example, the public sector or the corporate world.

<p>The purpose of this dissertation is to contribute to a better understanding of how global seafood trade interacts with the governance of small-scale fisheries (SSFs). As global seafood trade expands, SSFs have the potential to experience significant economic, social, and political benefits from participation in export markets. At the same time, market connections that place increasing pressures on resources pose risks to both the ecological and social integrity of SSFs. This dissertation seeks to explore the factors that mediate between the potential benefits and risks of global seafood markets for SSFs, with the goal of developing hypotheses regarding these relationships. </p><p>The empirical investigation consists of a series of case studies from the Yucatan Peninsula, Mexico. This is a particularly rich context in which to study global market connections with SSFs because the SSFs in this region engage in a variety of market-oriented harvests, most notably for octopus, groupers and snappers, lobster, and sea cucumber. Variation in market forms and the institutional diversity of local-level governance arrangements allows the dissertation to explore a number of examples. </p><p>The analysis is guided primarily by common-pool resource (CPR) theory because of the insights it provides regarding the conditions that facilitate collective action and the factors that promote long-lasting resource governance arrangements. Theory from institutional economics and political ecology contribute to the elaboration of a multi-faceted conceptualization of markets for CPR theory, with the aim of facilitating the identification of mechanisms through which markets and CPR governance actually interact. This dissertation conceptualizes markets as sets of institutions that structure the exchange of property rights over fisheries resources, affect the material incentives to harvest resources, and transmit ideas and values about fisheries resources and governance.</p><p> The case studies explore four different mechanisms through which markets potentially influence resource governance: 1) Markets can contribute to costly resource governance activities by offsetting costs through profits, 2) markets can undermine resource governance by generating incentives for noncompliance and lead to overharvesting resources, 3) markets can increase the costs of resource governance, for example by augmenting monitoring and enforcement burdens, and 4) markets can alter values and norms underpinning resource governance by transmitting ideas between local resource users and a variety of market actors. </p><p>Data collected using participant observation, survey, informal and structured interviews contributed to the elaboration of the following hypotheses relevant to interactions between global seafood trade and SSFs governance. 1) Roll-back neoliberalization of fisheries policies has undermined cooperatives’ ability to achieve financial success through engagement with markets and thus their potential role as key actors in resource governance (chapter two). 2) Different relations of production influence whether local governance institutions will erode or strengthen when faced with market pressures. In particular, relations of production in which fishers own their own means of production and share the collective costs of governance are more likely to strengthen resource governance while relations of production in which a single entrepreneur controls capital and access to the fishery are more likely to contribute to the erosion of resource governance institutions in the face of market pressures (chapter three). 3) By serving as a new discursive framework within which to conceive of and talk about fisheries resources, markets can influence norms and values that shape and constitute governance arrangements.</p><p>In sum, the dissertation demonstrates that global seafood trade manifests in a diversity of local forms and effects. Whether SSFs moderate risks and take advantage of benefits depends on a variety of factors, and resource users themselves have the potential to influence the outcomes of seafood market connections through local forms of collective action.</p> / Dissertation

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Objetivos. a) analisar os fatores associados à criação de relações de sinergia entre poder público e sociedade no âmbito do Consórcio Intermunicipal das Bacias Hidrográficas dos rios Piracicaba, Capivari e Jundiaí, assim como a contribuição desta organização para a gestão dos recursos hídricos na região; e b) contribuir para as discussões sobre novas formas de institucionalidade na gestão de recursos naturais. Metodologia. A metodologia de pesquisa combina três instrumentais complementares: pesquisa documental, um survey aplicado a membros do Consórcio em uma amostra aleatória, e questionários complementares com atoreschave, utilizando como suporte para a análise a ferramenta organizacional IAD (Institutional Analysis and Development). Resultados. Os resultados explicitam que características relacionadas ao contexto físico e político, às formas das relações e articulações estabelecidas entre os atores, e o estabelecimento de relações interinstitucionais e intersetoriais no contexto de gestão dos recursos hídricos possibilitaram a emergência de sinergia no caso estudado. A experiência do Consórcio PCJ na gestão dos recursos hídricos foi pioneira no Estado e mesmo no País, tendo contribuído para avanços significativos não apenas regionalmente, com nos níveis estadual e nacional. Apesar disso, ainda se observam dificuldades na inclusão de maior heterogeneidade no processo de participação na gestão desses recursos. Considerações. No caso do Consórcio PCJ, falta ainda ampliar o acesso ao diálogo com uma parcela mais abrangente da população, contribuindo de forma mais efetiva para a formação de processos educativos que ampliem a quantidade e qualidade da participação social nos processos de gestão dos recursos hídricos. Abordando as possibilidades de uma nova institucionalidade na gestão de recursos naturais, o estudo indica a importância da formulação de políticas públicas que apóiem e fomentem: a) o envolvimento de instituições já consolidadas na catalização de processos de articulação entre outras instituições em torno de objetivos comuns; b) o diálogo entre poder público, iniciativa privada e sociedade civil organizada; c) o diálogo entre diferentes escalas na esfera institucional; e d) a constituição de processos pedagógicos que qualifiquem e ampliem a participação da sociedade nos mesmos. / Objectives. a) to analyze the factors related to the creation of state-society relations in the \"Consórcio Intermunicipal das Bacias Hidrográficas dos rios Piracicaba, Capivari e Jundiaí\", as well as the contribution of this organization to the management of water resources in that region; b) to contribute to the proposal of new models of institutionality on natural resources management. Methodology. The research methodology combines three complementary instruments: documental research, a random sampling survey of members of the \"Consórcio\", and complementary surveys with key-actors, using as a support to the analysis the IAD (Institutional Analysis and Development) organizational tool. Results. Analysis of the data collected shows that characteristics related to the physical and political context, to the peculiarity of the relationships and articulations settled among the actors involved, and the settlement of interinstitutional and intersectorial relationships in the context of water resources management in that region, made the emergency of synergy in the case studied possible. The experience of \"Consórcio PCJ\" in the water resources management was pioneer in the State of São Paulo and even in Brazil, having contributed to significant advances not just regionally, but also at state and national levels. In spite of that, the difficulty of including a broader heterogeneity in the participation process for the management of these resources still remains. Considerations. In the case of \"Consórcio PCJ\", it is mandatory to develop means to expand the dialogue with a broader part of the society, contributing in a more effective way to building up the educational processes that could increase the quantity and quality of social participation in the management of water resources. With regard to the possibility of a new institutionality concerning natural resources management, this study points out the importance of the building of public policies that support and encourage: a) the involvement of already consolidated institutions in catalyzing processes of articulation among other institutions aiming at common goals; b) the dialogue between Public Administration, private initiative and the organized sectors of civil society; c) the dialogue among different scales in the institutional context; and d) the constitution of educational processes that qualify and broaden the participation of the society in them.

<div>Nucleate boiling is an efficient heat transfer mechanism that enables the dissipation of high heat fluxes at low temperature differences. Heat transfer phenomena during nucleate boiling are closely linked to the two-phase flow morphology that evolves in time and based on the operating conditions. In particular, the critical heat flux, which is the upper limit for the nucleate boiling regime, can be triggered by hydrodynamic mechanisms resulting from interactions between the liquid and vapor phases. The aim of this thesis is to characterize the two-phase flow morphology evolution during nucleate boiling at high heat fluxes in two configurations: pool boiling, and confined and submerged two-phase jet impingement. The characterization is performed via non-invasive, high-speed optical based diagnostic tools. </div><div>Experimental characterization of liquid-vapor interfaces during boiling is often challenging because the rapidly evolving vapor structures are sensitive to invasive probes and multiple interfaces can occlude one another along a line of sight. In this thesis, a liquid-vapor interface reconstruction technique based on high-speed stereo imaging is developed. Images are filtered for feature enhancement and template matching is used for determining the correspondence of local features of the liquid-vapor interfaces between the two camera views. A sampling grid is overlaid on the reference image and windows centered at each sampled pixel are compared with windows centered along the epipolar line in the target image to obtain a correlation signal. To enhance the signatures of true matches, the correlation signals for each sampled pixel are averaged over a short time ensemble correlation. The three-dimensional coordinates of each matched pixel are determined via triangulation, which yields a set of points in the physical world representing the liquid-vapor interface. The developed liquid-vapor interface reconstruction technique is a high-speed, flexible and non-invasive alternative to the various existing methods for phase-distribution mapping. This technique also has the potential to be combined with other optical-based diagnostic tools, such as tomographic particle image velocimetry, to further understand the phase interactions.<br></div><div>The liquid-vapor interface reconstruction technique is used to characterize liquid-vapor interfaces above the heated surface during nucleate pool boiling, where the textured interface resulting from the boiling phenomena and flow interactions near the heated surface is particularly suited for reconstruction. Application of the reconstruction technique to pool boiling at high heat fluxes produces a unique quantitative characterization of the liquid-vapor interface morphology near heated surface. Analysis of temporal signals extracted from reconstructions indicate a clear transition in the nature of the vapor flow dynamics from a plume-like vapor flow to a release mode dominated by vapor burst events. Further investigation of the vapor burst events allows identification of a characteristic morphology of the vapor structures that form above the surface that is associated to the square shape of the heat source. Vapor flow morphology characterization during pool boiling at high heat fluxes can be used to inform vapor removal strategies that delay the occurrence of the critical heat flux during pool boiling.</div><div>As compared to pool boiling, nucleate boiling can be sustained up to significantly higher heat fluxes during two-phase jet impingement. The increases in critical heat flux are explained via hydrodynamic mechanisms that have been debated in the literature. The connection between two-phase flow morphology and the extension of nucleate boiling regime is investigated for a single subcooled jet of water that impinges on a circular heat source via high-speed visualization from two synchronized top and side views of the confinement gap. When boiling occurs under subcooled exit flow conditions and at moderate heat fluxes, the regular formation and collapse of vapor structures that bridge the heated surface and the orifice plate is observed, which causes significant oscillations in the pressure drop across. Under saturated exit flow conditions, the vapor agglomerates in the confinement gap into a bowl-like vapor structure that recurrently shrinks, due to vapor break-off at the edge of the orifice plate, and replenishes due to vapor generation. The optical visualizations from the top of the confinement gap provide a unique perspective and indicate that the liquid jet flows downwards through the vapor structure, impinges on the heated surface, and then flows underneath the vapor structure, as a fluid wall jet the keeps the heated surface wetted such that discrete bubbles continue to nucleate. At high heat fluxes, intense vapor generation causes the fluid wall jet to transition from a bubbly to a churn-like regime, and some liquid droplets are sheared off into the vapor structure. The origin of critical heat flux appears to result from a significant portion of the liquid in the wall jet being deflected off the surface, and the remaining liquid film on the surface drying out before reaching the edge of the heater.</div><div>The flow morphology characterizations presented in this dissertation further the understanding of flow and heat transfer phenomena during nucleate boiling. In the pool boiling configuration, the vapor release process was quantitatively described; during two-phase jet impingement, a possible mechanism for critical heat flux was identified. Opportunities for future work include the utilization of image processing techniques to extract quantitative measurements from two-phase jet impingement visualizations. Also, the developed liquid-vapor interface reconstruction technique can be applied to a boiling situation with a simpler liquid-vapor interface geometry, such as film boiling, to generate benchmark data for validation and development of numerical models.</div><div><br></div>

In this study, I used restriction fragment length polymorphism (RFLP) analysis (DNA fingerprinting) to study the genetic population structure of wood frogs, Rana sylvatica, collected as egg masses from vernal pools within the Massachusetts Audubon Society Lincoln Woods Wildlife Sanctuary in Leominster, MA. The average genetic relatedness of sibling individuals, non-sibling individuals from within the same pool, and individuals from pools of close (5 m), far (200 m) and distant (40 km) spatial separations was calculated. The goal was to use genetic relatedness to estimate the breeding patterns of R. sylvatica and use that information to make general management recommendations that could be applied to other vernal pools breeders. I detected relative differences in genetic similarity between individuals from pools only 5 meters apart, however over a larger distance of 200 meters no significant genetic differences were present. This suggests that although wood frogs are known to be highly philopatric, they may use information other than simply proximity to their natal pool when choosing breeding sites. Factors such as species composition, water chemistry and heterogeneity of the landscape between pools may influence breeding site choice. Also, contrary to the findings of recent studies, the distance between vernal pools may not be the best indicator of the genetic similarity of the individuals they host. Pools in close proximity to one another may host genetically distinct populations, and therefore management decisions should be made on a pool-by-pool basis. Consequently, when managing populations of R. sylvatica, and possibly other vernal pool breeders, taking into account parameters other than simply the spatial separation of pools within an array may avoid decisions that could result in the loss of genetic diversity.