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The Coast to Karoo Transect investigates the abundance and diversity of ants and beetles along an altitudinal gradient in the Cederberg mountains of the Western Cape, South Africa. It is a long term project, initiated in 2002 by Prof. S.L. Chown, Stellenbosch University. Data collection is carried out on a biannual (spring and autumn) basis. To monitor changes in invertebrate assemblages, focusing on ants and beetles. Temperature data are collected with i-buttons and a Hobo data logger.

Cities are progressively heightening their climate aspirations to curtail urban carbon emis- sions and establish a future where economies and communities can flourish within the Earth’s eco- logical limits. Consequently, numerous climate initiatives are being launched to control urban car- bon emissions, targeting various sectors, including transport, residential, agricultural, and energy. However, recent scientific literature underscores the disproportionate distribution of climate poli- cies. While cities in the Global North have witnessed several initiatives to combat climate change, cities in the Global South remain uncovered and highly vulnerable to climate hazards. To address this disparity, we employed the Balanced Iterative Reducing and Clustering using the Hierarchies (BRICH) algorithm to cluster cities from diverse geographical areas that exhibit comparable socio- economic profiles. This clustering strives to foster enhanced cooperation and collaboration among cities globally, with the goal of addressing climate change in a comprehensive manner. In summary, we identified similarities, pa􏰀erns, and clusters among peer cities, enabling mutual and generaliza- ble learning among worldwide peer-cities regarding urban climate policy exchange. This exchange occurs through three approaches: (i) inner-mutual learning, (ii) cross-mutual learning, and (iii) outer-mutual learning. Our findings mark a pivotal stride towards a􏰀aining worldwide climate ob- jectives through a shared responsibility approach. Furthermore, they provide preliminary insights into the implementation of “urban climate policy exchange” among peer cities on a global scale.

Digital Annex for the following thesis: Vila-Viçosa, C. (2023). Natural History, Biogeography and Evolution of the Iberian white oak syngameon (Quercus L. Sect. Quercus). Ph.D. Thesis, Faculdade de Ciências da Universidade do Porto, Portugal Abstract: The genus Quercus L. is one of the most diverse and important group of woody plants, particularly when considering that they are the trees that rule the Northern Hemisphere forests. Oaks have an intricate Biogeography that criss-crosses diverse climatic and edaphic gradients, encompassing a huge ambiguity in terms of species delimitation. Frequently, the taxonomic proposals brought by traditional Linnaean Botany are either insufficient or rather inflate the number of species and nomenclatural assignments, which are further diluted into inconsistent taxonomic ranks, varying from species to subspecies and varieties. The supremacy given to morphological characters that are inherently fragile and plastic, spread across the distribution areas of distinct lineages, may carry ambiguity on the identification and proper species delimitation. From the oaks that are distributed across the Western Palearctic region, the ones that are deciduous or brevi-deciduous present higher levels of ambiguity in terms of species number and their delimitation. This ambiguity is particularly strong in the circummediterranean region and in the transitional areas between the two major biogeographic Regions of the western Palearctic region, the Euro-Siberian and Mediterranean. This degree of uncertainty, which increases towards the Southern European Peninsulas, is amplified by the ease that the different species of oaks tend to hybridize among them. The present work provides a holistic framework that covers multiple areas, from the taxonomic and evolutive study of this genus, to biogeography and molecular characterization. Its major objective was to resolve the species delimitation of the Iberian deciduous and marcescent oaks and putative introgression among them, enhancing the available knowledge about species diversity, which can foster suitable species and forest conservation. A specific objective was to cross-reference the natural history revision and the different taxonomic treatments brought by distinct authors, with personal observations. These data were then incorporated into ecological modelling and molecular characterization, which in the end fed a newly updated taxonomic proposal. In Section A we obtained results from extensive field, herbaria, and literature review, updating the nomenclature of the Portuguese and western Mediterranean oaks. Section B was supported by Section A’s in-depth review and enabled finer species distribution models, nurturing both hindcast (since ca. 20 Kyr) and forecast (2070-2100) exercises of the range dynamics of Mediterranean oaks species. The study of past and future range shifts solved important pending biogeographic questions, especially related to past range-shifts. Such past-range shifts improved our knowledge on species responses to climate dynamics and allowed a better anticipation of future responses of range shifts driven by climate change. Section C encompassed the molecular characterization of Iberian white oak species and their hybrids, whose delimitation is often faltering when one intends to infer about species rank, or hypothesize about the participation of parent taxon in natural hybrid swarms. This work allowed us to solve the phylogenetic backbone of western Palearctic white oaks, suggesting a significant segregation of the Iberian pedunculate oaks and unveiling two subsections inside Section Quercus. These subsections are biogeographically well-segregated and present diverse levels of introgression among species. Results demonstrated the efficiency of RADSeq for rebuilding the reticulate phylogeny of the Eurasian white oaks, showcasing the significance of the Iberian Peninsula as a major hotspot for oak diversity. We implemented a circular approach to these methods, which retro-fed themselves in terms of insight generation, enabling a powerful strategy to solve the evolutionary history of this difficult groups of plants. We estimate that the reticulate historical biogeography of the western Palearctic white oaks deserves further scrutiny by adding vicariant oak populations from northern Africa, the Near East and southern European Peninsulas. Methods should again follow this similar additive and sequential process of adjoining deep Natural History examination, with extensive fieldwork in type populations and genome-wide molecular surveys, in order to solve this group of plants. With the present work, we were able to significantly improve on the depiction of the basic unit of Biodiversity (the Species), in the complex Quercus genus. We provided tools to enable further efforts for the conservation of the Mediterranean oak forests, which overwhelm one of the most important (and one of the most threatened) Biomes for plant conservation at the global scale.

The Soutpansberg Transect investigates the abundance and diversity of ants and spiders along an altitudinal gradient in the Western Soutpansberg Mountains, South Africa. It has a north-south orientation over the mountain and is a long term project initiated in 2009. Data collection is carried out in intervals that suit the data logger capacity. To study the diversity patterns in ants and other invertebrate groups across the spatial transect over a long-term period and the climate the invertebrates.

Dielectric elastomers are highly promising as functional materials for the rapidly developing field of flexible actuator and generator technology. They offer a unique combination of low densities and large reversible deformations of up to more than 100% in area, and consequently have great potential for many new types of application. However, implementation has been impeded by the lack of specialized materials. The elastomers that have so far been investigated suffer from a number of disadvantages, including the need for very high activation voltages and limited service lifetimes. This thesis describes an investigation of the use of elastomeric composites as dielectric elastomers with the aim of optimizing and improving their performance in actuators. The influence of materials properties on actuation was first analyzed on the basis of a simple physical model and materials properties derived from standard test methods. The implications for the actuation performance of three conventional dielectric elastomers were then considered in detail. A preliminary conclusion was that the actuation performance could be improved if the permittivity of the elastomers were to be increased by modification with ceramic or conductive fillers. However, actuation performance was shown to depend not only on the permittivity, but also on the elastic modulus, the electrical breakdown strength, and strain hardening. Thus, although significant increases in permittivity were achieved by this approach, actuation performance was compromised by an increase in modulus in the case of the ceramic fillers, and a dramatic drop in electrical breakdown strength, in the case of the conducting fillers. A more promising approach was therefore suggested to be the use of an organic conducting filler encapsulated in an insulating matrix. It was demonstrated that it is indeed possible to increase the permittivity of a given elastomer while maintaining a high electrical breakdown strength. Different processing routes were investigated in order to control the dispersion of the filler and tailor performance. The optimum filler concentration, i.e. that providing the best compromise between permittivity and stiffness, was determined to be approximately 16 vol%, resulting in an improvement by a factor of 2 in actuation strain for a given applied voltage over that obtained with the unmodified matrix. Higher filler concentrations were also argued to have considerable potential for use in generators, given that the observed increased permittivity was also associated with high electrical breakdown strengths and increased strains at break. A threefold increase in converted energy per working cycle was predicted for a composite containing 25.5 vol% fillers based on a simplified model for a dielectric elastomer generator. Whilst these results are extremely encouraging, it is concluded that the composite approach has, in general, only limited potential as a means of obtaining further increases in actuation performance. The major difficulty remains that the use of a relatively rigid second phase to increase dielectric performance will inevitably also increase the elastic modulus beyond a certain filler concentration. As argued in the final part of the thesis, the way forward may therefore ultimately depend on the development of new types of synthetic elastomeric matrix materials that combine intrinsic improvements in electrical response with reduced moduli.

Dynamic pressure measurements are introduced as a powerful tool to detected filter failures at early stage. Filter failures such as leakages and blockages can be detected during back pressure recleaning pulses. High frequency sensors enable the recording of the recleaning pressure pulse. Patchy cleaning and depth filtration can be detected much faster with dynamic pressure measurements than with differential pressure measurements. Parameters derived from dynamic pressure data can be observed over time and compared with reference data. The method complements conventional pressure difference measurements and is applied at a hot gas filter that implements coupled pressure pulse (CPP) technology. Proceedings of the 20th European Biomass Conference and Exhibition, 18-22 June 2012, Milan, Italy, pp. 837-843

The Coast to Karoo Transect investigates the abundance and diversity of ants and beetles along an altitudinal gradient in the Cederberg mountains of the Western Cape, South Africa. It is a long term project, initiated in 2002 by Prof. S.L. Chown, Stellenbosch University. Data collection is carried out on a biannual (spring and autumn) basis. To monitor changes in invertebrate assemblages, focusing on ants and beetles.

A new concept of a system for Combined Heat and Power generation is presented. The concept is based on hybrid use of two renewable energy sources, direct solar (thermodynamic solar) and biomass (indirect solar energy). Biomass combustion is conducted using a fluidized bed combustor. A second source of energy, given by the direct irradiation of the bed with a concentrated solar radiation, is integrated in the same system, using the fluidized bed as solar receiver. A Stirling engine converts heat into mechanical power. A Scheffler type mirror is adopted to allow irradiation of the system in a fixed focal point. Advantages of the proposed solution are illustrated and some preliminary results on the performance of the system, obtained with a simple model, are presented. The principal improvements with respect to existing systems of similar size and primary energy source are illustrated. The most important are the enhanced heat transfer processes that are realized with the help of the fluidized bed, and the possibility of continuous cogeneration during the day. Different working conditions are considered to estimate the contribution given by the burning of fuel, in presence as well as in absence of sun irradiation (as during the night). The distribution of energy shares among the different flux contributes is reported versus the amount of biomass burned per unit time. The results clearly demonstrate the advantage of coupling, in the same system, two sources for heat generation, thus maintaining the option of producing electricity without the supply of biomass fuel.

Distributed power generation and cogeneration of heat and power is an attractive way toward a more rational conversion of fossil and bio fuels. Solid oxide fuel cell (SOFC) – gas turbine (GT) hybrid systems are emerging as the most promising candidates enabling the achievement of a cleaner and more efficient conversion of a large variety of resources across a broad power range covering from small to medium scale applications. This thesis introduces an innovative concept of SOFC-GT hybrid system that allows reaching efficiencies higher than the state of the art while enabling the carbon dioxide separation and avoiding fuel cell pressurisation technical issues. Several hybrid system design alternatives based on this concept are analysed through a thermodynamic optimisation approach combining process modelling, advanced process integration techniques and multi-objective optimisation. A number of optimal hybrid system configurations are determined for different design targets. The results consistently demonstrate the higher energy conversion performance and flexibility enabled with respect to the state of the art. The innovative concept analysis is extended to two applications for which SOFC-GT hybrid cycles are expected to provide the most significant impact toward sustainability: the small scale distributed generation and the conversion of renewable resources. A simplified version of the new hybrid system layout is especially developed for small scale distributed generation, typical of residential building applications (5-10 kWel). Experimental data are used to prove the technical feasibility of the system and to assess the performance potentially achievable with currently feasible technologies. The results of the analysis underline that energy conversion efficiencies higher than traditional centralised power generation can be achieved even at such a small scale. A systematic process integration and optimisation approach is used to assess the energy conversion performance of the original SOFC-GT hybrid cycle fuelled with hydrothermally gasified wet waste biomass. The analysis highlights the considerable potential of the integrated system that allows for converting wet waste biomass into electricity with First Law efficiency higher than 60% while simultaneously enabling the separation of the biogenic carbon dioxide.