• Energy Research
• Embargo close
• English close

Obesity is a growing health problem concerning much of the human civilization. Fundamental research into the underlying mechanisms of body weight regulation can open new paths that will lead to a larger array of treatment options. Leptin is a hormone that plays a crucial role in body weight regulation. It is known for reducing food intake and increasing energy expenditure via leptin receptor (LepR) signalling in the brain. Although leptin is known for reducing food intake, this thesis describes the variable effects of leptin on feeding in mice: after leptin injections, some mice decreased feeding, while others increased feeding. Even more, the feeding effect of leptin predicted how much weight a mouse gained on a high caloric diet: mice that increased feeding with leptin, gained more weight and vice versa. This thesis further addresses how LepR-neurons (neurons that are responsive to leptin) of different brain areas influence aspects of body weight regulation: food consumption, motivation to work for food reward, locomotor activity and body temperature. To do so, we used chemogenetics, which is a technique with which we can temporarily activate LepR-neurons of a certain brain area and examine the effect of this activation on behavioural tasks. We found that the four studied LepR-containing brain areas differently affect aspects of body weight regulation. This thesis sheds more light on how leptin and LepR-neurons influence body weight. With this we hope to contribute to exciting new discoveries that will aid in the reduction of the obesity pandemic.

From the British debate on the depletion of coal in 1865 to the First World Power Conference held in London in 1924, scientists, engineers, industrialists, and politicians produced new interpretations of the past, present, and future in terms of the mobilisation of energy resources. This thesis identifies an emerging ‘energy developmentalism’, which called for maximising energy use to maintain or improve a nation’s place in international competition. Energy developmentalism was not a marginal worldview confined to ‘energeticists’, but a coherent set of claims, measurements, and arguments that informed energy governance on an international scale. Rather than focusing on a single resource, energy developmentalism applied a unified schema to all energy sources, including those like solar and tidal energy that were still mostly theoretical. Drawing on sources from across Europe, while staying grounded in political changes in Britain and France, makes it possible to understand how a general formula for transforming raw materials with maximum efficiency was applied differently depending on specific political contexts. This period saw the articulation of problems like the depletion of resources, the difference between renewable and nonrenewable energy, the intermittency of renewables, the overreliance on a single source of energy, and the centrality of energy to modern economies – problems that are often associated with later periods. Scientific measurements of efficiency, horsepower, and kilowatts became operators in political debates centred on questions of national standing and progress. Even as oil became increasingly important in the world economy, the delegates at the First World Power Conference transformed a vision of a renewable energy future into one of a general expansion of energy consumption as the basis of progress. In so doing, they downplayed the continued importance of fossil fuels and equated ‘conservation’ with the fullest possible use of all energy sources, renewable or not.

This study answers a key question: how can the concept of sustainable development contribute to the sustainable realization of the human right to water for vulnerable people, by taking the following approaches. This was answered in the following ways. Firstly, by widening the scope of vulnerability to include environmental factors. Those who do not have access to water, as guaranteed by the human right to water, will be eligible for targeted measures when environmental vulnerability is considered in conjunction with social vulnerability. Secondly, the principles which accompany the concept of sustainable development can be used to inform and further develop the human right to water. In this manner the right will be sustainably realized and states will be able to meet both requirements under international human rights law as well as under environmental law. What does this mean for the human right to water at the international level? The human right to water was authoritatively interpreted in 2002 and politically accepted in 2010. The core requirements of the human right to water have been established and now attention should be given to aligning other provisions within international law relating to water resources. At the national level a sustainable human right to water will allow for context specifications to be taken into account. Those states which are confronted by, for instance, depletion will be able to justify allocation measures by referring to the human right to water. Also, individuals will be able to hold the state accountable for pollution on account of this right. When implementing the right at the national level, states should realize that it often requires harmonization and a better coordination of regulations and practices regarding the whole water sector as the case study of Suriname demonstrates. Suriname, has a great wealth of freshwater resources. Nevertheless, this country has to deal with two major issues. Firstly, providing access to safe water for domestic purposes for all those within its territory. Currently, the highest percentage of the population with access is in the urban areas reaching between 85 – 90 percent, followed by the rural area with 66.6 percent and, lastly, the Interior with just 20 percent. This means that the national percentage of the population with access to safe drinking water is around 72.6 percent and shows that even though there is enough freshwater within the Surinamese territory, not everyone is benefiting from it. The case study clearly demonstrates that the realization of the human right to water requires interventions on multiple levels. Adjusting the legal framework is not sufficient if the overall environment is not supportive of a right to water and water resources are not managed sustainably. The case studies also show that localizing the human right to water requires different measures and strategies in different contexts which happen to be in the same national context. Therefore, applying a nationwide strategy might not be effective or sustainable when states want to meet their obligations.

Climate change has been widely recognised as one of the most urgent and growing threats to natural and cultural heritage in the twenty-first century, and the indelible impact of humanity has led to the definition of a new geological epoch, the Anthropocene. Indigenous peoples are disproportionately affected by natural and human-induced changes to the environment. Their vulnerability is exacerbated by centuries of cultural and territorial disenfranchisement within settler-colonial nations. This dissertation aims at understanding Indigenous perceptions of heritage in the face of climate change and its intersection with the impacts of settler- colonialism. It analyses how these on-the-ground perceptions can, in turn, inform heritage organisations and contribute to safeguarding the many facets of tangible and intangible Indigenous heritage for future generations in the Anthropocene. This is accomplished through a comparative, transnational case study of two communities each from the Dehcho First Nations in the Northwest Territories, Canada, and the Aymara and Quechua peoples in northern Chile. I use a multi-method approach consisting of semi-structured interviews, oral histories and participant observation. The data is complemented by environmental and heritage legislation and grey literature at multiple organisational scales for both case studies. Three lines of enquiry are explored through an applied comparative thematic analysis: i) the perceptions of climate change and associated land loss/change among Indigenous groups and how this impacts each group’s notions of challenges to its cultural identity; ii) the intersection of the effects of post- colonialism, ongoing industrial activities and climate change on the intergenerational transmission of ancestral knowledge and notions of place attachment; and iii) how international, national and regional political and sociocultural rhetoric on environmental and heritage conservation affect local, grassroots considerations for safeguarding heritage. The similarities and contrasts of the Dehcho First Nations, Aymara and Quechua experiences of climate change across the North-South divide are related from the grassroots to arrive at redefining heritage practices in the Anthropocene. The results demonstrate that decolonising heritage is not only necessary, but that this decolonisation depends on building and actively engaging in intercultural empathy through the global threat of climate change. In order to understand how Indigenous practices, places, and items are valorised—attributed value—as heritage in the face of climate change, one must empathise with the cultural loss that exists in the temporal and cognitive spaces between Indigenous individuals’ moments of nostalgic reference and today.

The photovoltaic industry attracts a lot of interest from researchers worldwide due to active integration of the solar cells. The main idea here is to convert solar energy into electricity. One type of solar cell that shows potential in replacing today’s crystalline silicon cells is the thin film solar cell (TFSC). Yet, the sun absorbing semiconductors used in the commercial TFSCs contain scarce elements such as indium, cadmium and tellurium, which may cause problems if the technique is going to grow to a big scale energy producer. Earth abundant sun absorbing materials are therefore of great interest, and several possible replacements are under investigation. In this project two olivine structured ternary metal chalcogenides were investigated: manganese silicon sulfide (Mn2SiS4) and iron silicon sulfide (Fe2SiS4). The goal was to deposit thin films by reactive magnetron sputtering from manganese/iron and silicon targets with mixture of Ar and H2S gas. Afterwards the films were crystallized by a sulfurization process at high temperature. The samples were created with a composition gradient and investigated by SEM, EDS and XRD. Results showed that a single phase of Mn2SiS4 was successfully created in thin film form for the first time. Multiple attempts on manufacturing Fe2SiS4 were performed, but didn't show sufficient progress yet. The analysis showed formation of pyrite (FeS2), pyrrhotite (Fe1-xS, x<0.2) and SiS2 phases instead of the targeted material. In both cases it is important to provide additional studies to determine if the selected compounds could be used as an absorber layer in TFSC structures.

The use of bioethanol as a biofuel make it possible to reduce the dependence on fossil fuel and the greenhouse emissions. The advantage of bioethanol is that is obtained by fermentation of renewable resources that capture carbon dioxide during its growing providing a null net balance of carbon dioxide emissions. Applying the concept of green engineering led to total or partial substitution of fossil fuel. The main drawback is that fermentation is produced in diluted aqueous media and the recovery of ethanol is an energy intensive operation and in Europe, the maximum ethanol content in fuel allowed by legislation is 10% wt (Directive 2009/10/EC). The objective of this project is to provide a process scheme that led to dehydrate bioethanol and blend directly with gasoline and gasoline additive, tert-amyl-methyl ether (TAME). This process must to be viable in terms of energy, economics and environmental aspects. A bibliographic search is presented to determine how much energy is necessary to produce one kilogram of bioethanol. The results of the bibliographic search shown that for a diluted feed stream of ethanol, the best process scheme consist on two distillation columns and one decanter. Hence, five process schemes are presented: (1-3) with the conventional configuration (two distillation column and one decanter) and (4-5) with a novel configuration (one distillation column, with a lateral extraction, and one decanter). The residue curve maps and liquid-liquid equilibrium (RCM-LLE) with their topologies are presented. The RCM-LLE allows to illustrate the thermodynamic behavior of the entrainers used and verify the feasibility. The software used to carry out the rigorous simulations is ASPEN Plus ® v10 using the thermodynamically model NRTL. The annual production established is 18kt/year of a mixture ethanol-gasoline-TAME. The converged results of the simulations allow to compare all the process schemes in terms of energy, sizing and economic aspects, such as raw materials cost, utilities cost, equipment cost and income statement. Beyond this, WAR® is used to compare the environmental impact of each process scheme using coal, oil and natural gas as an energy source Treballs Finals de Màster d'Enginyeria Química, Facultat de Química, Universitat de Barcelona, Curs: 2018-2019, Tutors: Alexandra Bonet Ruiz, Manuel Vicente Buil

Achievement of sustainable development in light of ongoing climate change and biodiversity pressures benefits from the deployment of innovations that foster engagement and uptake across all levels, mobilises finance flows commencement to the scale of the challenge, and enables the dissemination of transition solutions that support the low carbon economy. This research investigates the relationship between the legal architecture of market mechanisms under international law and the role of private actors, and how this contributes to sustainable development. Through an exploration of how market mechanisms under the climate change and biodiversity regimes have achieved environmentally sound outcomes, been advanced in sectoral approaches, and facilitated via bilateral and multilateral trade and investment relationships, important insights are identified regarding the composition of effective law and governance architectural approaches. Leveraging experiences derived from treaty practice viewed through an interactional account of international law, this assessment elucidates the important role played by alignment of legal regimes, robust transparency measures, and complementary schemes such as stakeholder-endorsed certifications in buttressing the established measures to ensure sustainable development outcomes and contributes to understanding the role of private actors in the operationalisation of environmental agreements. Research findings suggest it is the interaction of norms across the international legal architecture, informed by relationships within and across relevant treaty systems and the general corpus of international law, and actualised through engagement with private actors as a component of market mechanisms that provides the opportunity for congruence of practice, forging of shared understandings, and normative internalisation and ownership among communities of practice that stimulates both innovative solutions and ambitious action.