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AbstractClimate change effects along with anthropogenic activities present the main factors that threaten the existence of heritage sites across the north Nile Delta of Egypt close to the coastline of the Mediterranean Sea. Observing the changes in the landscape close to the archaeological sites is an important issue for decision‐makers in terms of reducing the negative impact of natural events and human activities. The coastal heritage sites are becoming strongly threatened by the rising sea level phenomena that will happen due to global warming. Focusing on the distribution of the archaeological sites, this study aims to detect the areas at risk of shoreline erosion or accretion in the northern shoreline of the Nile Delta. In this study, the changes in the northern shoreline of the Nile Delta were observed and calculated during the last hundred years based on the integration between the old topographic maps from surveys in 1900, 1925 and 1945, optical satellite images captured by Landsat in 1972, 1986 and 2000; Sentinel2 2021; and the Radar SRTM data. The results of this study showed that the changes were enormous with a great shoreline erosion process over the last 121 years recorded along the shoreline in the periods between 1900–1925, 1925–1945, 1945–1972, 1972–1986, 1986–2000 and 2000–2021. The areas eroded were about 5.3, 4.7, 5.6, 8.9, 2.5 and 5.4 km2, respectively. Such negative movements caused the loss of two heritage sites, and the expected changes will lead to the loss of additional heritage sites in the next 500 years. Furthermore, a model was suggested for protecting the coastal heritage sites threatened by the risk of submergence. This study can help the decision‐makers to detect the coastal archaeological sites at risk and create innovative solutions for protecting these irreplaceable heritage sites.

Artículos en revistas Numerical models of transmission-constrained electricity markets are used to inform regulatory decisions. How robust are their results? Three research groups used the same data set for the northwest Europe power market as input for their models. Under competitive conditions, the results coincide, but in the Cournot case, the predicted prices differed significantly. The Cournot equilibria are highly sensitive to assumptions about market design (whether timing of generation and transmission decisions is sequential or integrated) and expectations of generators regarding how their decisions affect transmission prices and fringe generation. These sensitivities are qualitatively similar to those predicted by a simple two-node model. info:eu-repo/semantics/publishedVersion

This thesis explores Germany’s *Energiewende* (‘energy transition’) and the role of citizen/community energy democracy initiatives at municipal and state levels in shaping developments that underpin this society-wide transformation - examining how grassroots agitation, in particular, has prompted meaningful action and policy change on the part of government at multiple levels. Using Berlin and Hamburg - Germany’s largest urban centers and leading city-states in the country’s federal system - as case studies, the research examines how citizens’ initiatives in both cities have campaigned for the remunicipalization of local energy networks to expedite, democratize, and incorporate social justice goals into each region’s Energiewende. Finally, this study pivots to consider the progress of the transition nationally in recent years, investigating how major events like the Covid-19 pandemic, watershed federal elections in 2021, war in Ukraine, and the resultant energy crisis have affected the evolution and direction of the Energiewende, and the important contributions of citizen/community energy initiatives to the national response here. The analytical framework draws on over 100 interviews conducted with relevant stakeholders and experts involved in the transition, representing different perspectives (e.g. on remunicipalization and the Energiewende itself) and diverse levels of government (e.g. from the district to federal level). This extensive body of original research is complemented by a wide array of other relevant source material that has likewise been consulted to inform this work and further evaluate the impacts of bottom-up energy democracy initiatives on the broader transition in Germany’s regions - and, by extension, nationally - as they continue to affect the pace and trajectory of the now-famous Energiewende. Ultimately, this study contributes an in-depth, ground-level analysis to the literature of key elements that have driven energy system change in Germany, shining a fresh light on the complex and interrelated nexus of sustained grassroots action, policy responses, and shifting sociopolitical realities that form the context in which the Energiewende has been (re)launched, reformed, and reimagined over the decades.

In recent decades, many societal changes have unfolded, including population ageing, reconfigurations of household structures, labour market transformation, and a secular deceleration of economic growth. These shifts pose considerable challenges to preexisting welfare states, particularly to the efficacy of countries’ pension systems. This dissertation examines the context and trajectory of pension reforms in Mexico, the United Kingdom, and the United States. Its contribution is to ascertain the viability and political feasibility of reforms that enhance the financial sustainability of their pension systems, while maintaining adequate income and coverage levels. The dissertation builds on political economy approaches and on the institutionalist literature, which highlight how the role of interest groups and structure of institutions and political systems shape policy outcomes. The frameworks of blame avoidance and credit-claiming are also considered, to provide a comprehensive analysis of the complex dynamics surrounding pension systems and reform efforts. This dissertation uses a mixed-methods approach – including public opinion surveys of 3,000+ individuals, semi-structured elite interviews, historical document analyses, and specialized fiscal and actuarial projections of selected pension reforms in the three selected countries. It addresses three core research questions: 1) What is the current context for pension reform in Mexico, the United Kingdom, and the United States given their histories? 2) Is the necessary (for achieving specific minimum levels of sustainability, adequacy, and coverage) pension reform politically feasible? 3) How do the characteristics of each reform affect its political feasibility? Corollary: The modification of which channel (benefits, contributions, retirement age) is perceived as more politically feasible for diverse stakeholders? The methodology chosen provides a timely picture of the context surrounding potential pension reforms in the three case studies. In Mexico, credit-claiming and the interests of private stakeholders explain the success of recent pension reforms, and partisan politics are the key determinants for future fiscal changes. For the United Kingdom, the institutionalist literature helps explain the reasons for the relatively easier reform avenues; the most politically feasible reforms are those in the private sector, while the housing market is of key importance for pensions. In the United States, the institutionalist literature and the framework of blame avoidance also help explain the current legislative gridlock and the reasons why no major reform has been enacted for decades. For Mexico and the United Kingdom there exist politically feasible reforms, notably a modification of the retirement age channel, that can increase the system’s sustainability while maintaining income adequacy and coverage; whereas based on the current context of extreme polarisation and legislative gridlock, there do not seem to exist politically feasible pension reforms that preserve the structure of Social Security in the United States. The dissertation brings the lens of political feasibility to bear on a previously technical literature on the structure of the pension systems in the three countries, and thus on the feasibility of reform to deliver financial sustainability, adequacy of retirement incomes, and adequate coverage of the old age population. It identifies the feasible routes for reform in Mexico and the United Kingdom, but concludes that the political economy context the United States has reached rules out feasible reforms of its current pension structures.

Combined conduction–convection–radiation heat transfer is investigated numerically in a micro-channel filled with a saturated cellular porous medium, with the channel walls held at a constant heat flux. Invoking the velocity slip and temperature jump, the thermal behaviour of the porous–fluid system are studied by considering hydrodynamically fully developed flow and applying the Darcy–Brinkman flow model. One energy equation model based on the local thermal equilibrium condition is adopted to evaluate the temperature field within the porous medium. Combined conduction and radiation heat transfer is treated as an effective conduction process with a temperature-dependent effective thermal conductivity. Results are reported in terms of the average Nusselt number and dimensionless temperature distribution, as a function of velocity slip coefficient, temperature jump coefficient, porous medium shape parameter and radiation parameters. Results show that increasing the radiation parameter $$(T_{r})$$ and the temperature jump coefficient flattens the dimensionless temperature profile. The Nusselt numbers are more sensitive to the variation in the temperature jump coefficient rather than to the velocity slip coefficient. Such that for high porous medium shape parameter, the Nusselt number is found to be independent of velocity slip. Furthermore, it is found that as the temperature jump coefficient increases, the Nusselt number decrease. In addition, for high temperature jump coefficients, the Nusselt number is found to be insensitive to the radiation parameters and porous medium shape parameter. It is also concluded that compared with the conventional macro-channels, wherein using a porous material enhances the rate of heat transfer (up to about 40 % compared to the clear channel), insertion of a porous material inside a micro-channel in slip regime does not effectively enhance the rate of heat transfer that is about 2 %.

The aggravating global problems of energy crisis, rising atmospheric greenhouse gas concentrations and accumulation of persistent waste have attracted the attention of scientists, policy-makers and global organisations to come up with effective and expeditious solutions to address these challenges. In this context, the development of sustainable technologies driven by renewable energy sources for the production of clean fuels and commodity chemicals from diverse waste feedstocks is an appealing approach towards creating a circular economy. Over the years, semiconductor photocatalysts based on TiO₂, CdS, carbon-nitrides (CNx) and carbon dots (CDs) have been widely used for the photocatalytic reforming (PC reforming) of pre-treated waste substrates to organic products, accompanied with clean hydrogen (H₂) generation. However, these conventional solar-driven processes suffer from major drawbacks such as low production rates, poor product selectivity, CO₂ release, challenging process and catalyst optimisation, and harsh waste pre-treatment conditions, which limit their commercial applicability. These challenges are tackled in this thesis with the introduction of new and efficient photoelectrochemical (PEC) and chemoenzymatic processes for reforming a diverse range of waste feedstocks to sustainable fuels. Solar-driven PEC reforming based on halide perovskite light-absorber is first developed as an attractive alternative to PC reforming. The PEC systems consist of a perovskite|Pt photocathode for clean H₂ production and a Cu-Pd alloy anode for reforming diverse waste streams, including pre-treated cellulosic biomass, polyethylene terephthalate (PET) plastics, and industrial by-product glycerol into industrially-relevant, value-added chemicals (gluconic acid, glycolic acid and glyceric acid) without any externally applied bias or voltage. Additionally, the single light-absorber PEC systems can also convert the airborne waste stream and greenhouse gas CO₂ to diverse products with the simultaneous reforming of PET plastics with no applied voltage. The perovskite-based photocathode enables the integration of different CO₂ reduction catalysts such as a molecular cobalt porphyrin, a Cu-In alloy and formate dehydrogenase enzyme, which produce CO, syngas and formate, respectively. The versatile PEC systems, which can be assembled in either a ‘two-compartment’ or standalone ‘artificial leaf’ configurations achieve 60‒90% oxidation product selectivity (with no over-oxidation) and >100 µmol cm‾² h‾¹ product formation rates, corresponding to 10²‒10⁴ times higher activity than conventional PC reforming systems. In addition to developing PEC platforms, this thesis also explores avenues for circumventing the harsh alkaline pre-treatment strategies (pH >13, 60‒80 ºC) adopted for photoreforming waste substrates. For this purpose, a chemoenzymatic pathway is introduced whereby PET and polycaprolactone plastics were deconstructed using functional enzymes under benign conditions (pH 6‒8, 37‒65 ºC), followed by PC reforming using Pt loaded TiO₂ (TiO₂|Pt) or Ni₂P loaded carbon-nitride (CNx|Ni₂P) photocatalysts. The chemoenzymatic reforming process demonstrates versatility in upcycling polyester films and nanoplastics for H₂ production at high yields reaching ∼10³‒10⁴ µmol gsub‾¹ and activities at >500 µmol gcat‾¹ h‾¹. The utilisation of enzyme pre-treated plastics also allowed the coupling of plastic reforming with photocatalytic CO₂-to-syngas conversion using a phosphonated cobalt bis(terpyridine) co-catalyst immobilised on TiO₂ (TiO₂|CotpyP). Finally, moving beyond solar-driven systems, a bio-electrocatalytic flow process is demonstrated for the conversion of microbe pre-treated food waste to ethylene (an important feedstock in the chemical industry) on graphitic carbon electrodes via succinic acid as the central intermediate. In conclusion, with its focus on improving efficiencies, achieving selective product formation, building versatile platforms, diversifying substrate and product scope, and reducing carbon footprint and economic strain, this thesis aims to bring sustainable waste-to-fuel technologies a step closer to commercial implementation.

Abstract While it is generally accepted that our fossil fuel-dominated energy systems must undergo a sustainable transition, researchers have often neglected the potential impacts of this on water and land systems. However, if unintended environmental impacts from this process are to be avoided, understanding its implications for land use and water demand is of crucial importance. Moreover, developed countries may induce environmental stress beyond their own borders, for instance through extensive imports of bioenergy. In this paper, Germany serves as an example of a developed country with ambitious energy transformation targets. Results show that in particular, the politically-driven aspiration for more organic farming in Germany results in a higher import quota of biomass, especially biofuels. These imports translate into land demand, which will exceed the area available in Germany for bioenergy by a factor of 3–6.5 by 2050. As this will likely bring about land stress in the respective exporting countries, this effect of the German energy transformation ought to be limited as much as possible. In contrast, domestic water demand for the German energy system is expected to decrease by over 80% through 2050 due to declining numbers of fossil-fuelled power plants. However, possible future irrigation needs for bioenergy may reduce or even counterbalance this decreasing effect. In addition, energy policy targets specific to the transport sector show a high sensitivity to biomass imports. In particular, the sector-specific target for greenhouse gas reductions will seemingly promote biomass imports, leading to the above-described challenges in the pursuit of sustainability.

Ammonia has been responsible for feeding population growth in the 20th century through synthetic fertilizer, and is poised to become the preferred energy storage medium for a society powered by renewable electricity in the 21st century. However, conventional brown ammonia production through the Haber-Bosch process is optimized for utilization of centralized and steady energy supply from fossil-fuels. When shifting to distributed and intermittent energy supply through wind and solar energy, a re-optimization is required for a low-capital and flexible green ammonia production processes. This thesis re-designs and Haber-Bosch process by targeting the integration of reaction and separation in a single process vessel at low pressures, thereby achieving the simplification and down-scaling of the high pressure recycle loop of the Haber-Bosch process. Materials are developed for this purpose, the feasibility of integration is demonstrated, and mathematical modeling is utilized for assessing the application of the single-vessel process to a range of renewable energy sources in comparison to competing ammonia production processes. Herein, a catalyst with low-temperature (< 350°C) and high-conversion (i.e. near equilibrium) activity is developed using ruthenium nanoparticles as the active metal supported on ceria and promoted with cesium to mitigate hydrogen and ammonia inhibition, respectively. This catalyst is compared to commercial iron-based catalyst from the perspective of the final application. Concurrently, a high-temperature (> 300°C) manganese chloride absorbent is developed that resists decomposition and is stable when supported on silica. These catalyst and absorbent are integrated in a layered reactor configuration to demonstrate the feasibility of the integrated process by exceeding single-pass reaction equilibrium. Mathematical modelling of ammonia production processes illustrates that at small-scales (< 1 t day-1) the single-vessel process is optimal compared to the Haber-Bosch process due to its modular design. In addition, it can achieve simpler ramping because the Haber-Bosch process is constrained by heat-integration in the recycle loop and the potential for runaway reaction. For final application, the pairing of ammonia production processes with examples of intermittent solar and wind sources demonstrates that the flexibility of the production process is essential when considering non-ideal sources of energy with a long-term (e.g. seasonal) oscillations. Flexible ammonia production also expands the economic usage of ammonia as an energy storage vector from the seasonal to the weekly time-scale, with advantage compared to batteries or hydrogen. The work of this thesis provides a framework for advancing the electrification of the chemical industry given the novel constrains of intermittent and distributed renewable energy. A systems level approach is applied from the ground up, starting from material design and progressing to optimized process design and application.

Digitalization trends in building management increasingly emphasize the creation of Digital Twins (DTs) for building management but often neglect how occupants interact with these technologies. This paper aims to explore the functionalities of building management systems based on occupant interactions with DTs. To achieve this, occupant preferences are investigated through a questionnaire survey conducted with 106 respondents from two case studies. The survey investigated participants’ interest in using DTs for various building management tasks, their familiarity with DTs and their demographic factors. Analysis results revealed that occupant’s interest in DTs is not significantly influenced by their prior knowledge or gender. Instead, providing access to DTs increased their interest in areas beyond their job roles, particularly in aspects related to comfort and environmental management. Younger participants showed a heightened interest in using DTs for environmental and energy management issues. The study also suggests that promoting occupant interaction with DTs can enhance productivity and satisfaction. This paper underscores the need for additional research to integrate smart technologies into building management with a focus on occupant involvement. It highlights the potential of DTs to improve real-time monitoring and support sustainability initiatives and thus, offers a more inclusive and effective alternative to traditional management tools. This work was supported by the Association Nationale de la Recherche et de la Technologie (ANRT) under the Grant CIFRE 2017/1782. Peer Reviewed