In this report, connectivity modeling has been performed using land cover data to find habitat pinch-points for deer along the study area Norrortsleden in Stockholm. Norrortsleden was chosen because there are a high number of deer accidents in the area, and is a priority area for action according to a barrier analysis for deer made by the Swedish Transport Administration. After interviews and research, it was found that a tool named LinkageMapper using CircuitScape theory is one good way to find habitat pinch-points along transport corridors. Firstly, a habitat resistance raster map and zone data are needed. The habitat resistance layer was made using ground cover data and given resistance values specifically for deer. An edge-zone layer was also added on top using built-in ArcGIS tools. Lastly all the road and railway data was transformed into raster and added to the final resistance layer. To find the pinch-points in the natural habitat for deer, different settings for the ArcGIS tool LinkageMapper have been tested and variations of the zone layer have been used. LinkageMapper is an external free to download tool and uses CircuitScape theory to find habitat pinch points. Different settings were tested for a 2-zone version on a 2 km buffer on each side of the road. In addition, two main settings are available, all-to-one mode and pairwise mode in LinkageMapper. Input width must also be entered to limit the number of results. Corridor width was set to 50 m for all of the produced results. After preparation of the raw data, processing zones and resistance layers it was found that usually only one corridor was showing, so a version with 6 zones on each side of the road with a 4 km buffer was made and produced more continuous results. All of the pinch-points found were marked on a map and the ones not already near an existing wildlife passage are located just south of Lake Vallentuna. The research found that the GIS-based approach is effective for Identifying high-priority locations of defragmentation across transport corridors. Using CircuitScape theory can be a great compliment too regular least cost-path.

This study examined the impact intervening environment has on gene flow in the insect pollinated understory tree, Cornus florida L., by combining GIS and landscape genetic techniques (Least Cost Path Analysis, Circuit Theory, and Conditional Genetic Distance). Traditional population genetic analysis indicated pair-wise relatedness was significantly correlated to distance (Pearson; r = -0.312, P < 0.001) suggesting a spatial component to offspring relatedness. Dispersal throughout the study site was non-random, exhibiting a high degree of pollen pool structure due to restricted gene flow (Two-Generation Analysis; Φft = 0.161, P = 0.001). Forest structure was quantified in GIS layers representing coniferous canopies, mixed hardwood canopies, C. florida canopies, open understory (roads), and open understory/canopy due to tree removal. Of these layers, landscape isolation for the roads layer provided the best-fit model for describing genetic differentiation among sampled pollen pools (Mantel; r = 0.542, P = 0.001). These data also suggest that improved biological inferences can be gained by examining a range of landscape isolation models.

Southern Africa contains 58% of the world’s savannah elephant population, yet 72% of their range occurs outside of protected areas. It is, therefore, important to develop management guidelines that satisfy the needs of both elephants and people while maintaining environmental heterogeneity and ecosystem processes. Managing elephants as a metapopulation may provide the solution. The goal of this thesis was then to use a habitat-based approach to identify landscape characteristics which could contribute to the functionality of a metapopulation for elephants. Using resource selection function models, I identified habitat suitability for elephants across southern Africa and used these models to evaluate whether current habitat configurations allow for the assumptions of connectivity and asynchronous population dynamics required by a metapopulation. I found that water, tree cover, slope, and human presence were important predictors of elephant habitat selection. Furthermore, functional responses in habitat selection were present across space and time for water and tree cover, showing the adaptability of this generalist species to resource heterogeneity. Using habitat selection along with circuit theory current flow maps, I then found a high likelihood of connectivity in the central portion of our study area (i.e. between the Chobe, Kafue, Luangwa, and Zambezi cluster). Main factors limiting connectivity were the high human density in the east and a lack of surface water in the west. These factors effectively isolate elephants in the Etosha cluster in Namibia and Niassa clusters in Mozambique from the central region. Models further identified two clusters where elephants might benefit from being managed as part of a conservation network, 1) northern Zambia and Malawi and 2) northern Mozambique. Incorporating information on elephant mortalities in northern Botswana into habitat selection estimations, I found that source habitats for elephants occurred within the central Okavango Delta region and sink habitats were associated with periphery of the study area where human use was highest. Eighty percent of elephant mortalities occurred within 25 km of people. The protected designation of an area had less influence on elephant mortality than did the locations of the area in relation to human development. To exacerbate human-elephant conflicts, people tended to settle in areas of high-quality elephant habitats, creating resource competition between elephants and people. Consequently, elephant mortality near humans increased as a function of habitat suitability, and elephants responded by using less suitable habitats. While humans occupied only 0.7% of the study area, mortality and behavioural effects impacted 43%. Based on the habitat factors examined here, elephants in southern Africa could be managed as a metapopulation if (1) connectivity is maintained and encouraged and (2) spatial heterogeneity in resources and risks serves to stabilize elephant demography. This habitat-based system of management could serve to alleviate unstable elephant populations in southern Africa and create more natural, self-sustaining regulatory mechanisms. / Thesis (PhD)--University of Pretoria, 2013. / Zoology and Entomology / unrestricted

The growing demand for urban areas has been a driving force for extensive changes to landscape. Thisrequires more focus on finding a balance between promoting urban development, and conservingbiodiversity in urban areas. The Intergovernmental Science-Policy Platform on Biodiversity andEcosystem Services (“IPBES”) suggests encouraging sustainable urban planning, as well as“maintaining, and designing for, ecological connectivity in urban spaces”. Ecological connectivity canbe modelled based on circuit theory. Landscape can be depicted as a conductive surface and resistancecan be attributed to landscape types according to its permeability to the movement of a species.Frösön is a district in the growing municipality of Östersund, Sweden, where several developmentplans are intended. This study aimed to identify where structural ecological connectivity existed inFrösön. It also aimed to determine where connectivity was disturbed by urban development, andexplore the options available to strengthen connectivity through establishing new ecological corridors.Land cover data was analysed to identify the forest patches that were larger than 50 000m2, andresistance values were attributed per land cover type. Circuitscape was used to model the connectivitybetween the forest patches, revealing the connectivity across Frösön. The development plans wereassessed to determine where the developments overlapped existing corridors with high connectivityvalues between forest patches. New corridors (pathways connecting high connectivity valuesbetween forest patches) that could compensate for the impact by development plans on connectivityas well as strengthen connectivity throughout Frösön were proposed. The findings in this reportconcur with the IPBES that urban development can be sustainable while preserving biodiversity.Additionally, the inclusion of connectivity models in the environmental impact assessment (“EIA”)process for developments, enables proactive decision-making on the design and location ofdevelopments. Moreover, it encourages urban development and the preservation of landscapeconnectivity. This study will be valuable to environmentalists carrying out EIAs and specialists thatopine on environmental policy and/or legislation. / <p>2022-0604</p>

Les récupérateurs d'énergie vibratoire électrostatiques (REV) sont des systèmes convertissant une partie de l'énergie cinétique de leur environnement en énergie électrique, afin d'alimenter de petits systèmes électroniques. Les REV inertiels sont constituées d'un sous-système mécanique bâti autour d'une masse mobile, ainsi que d'une interface électrique. Ces deux blocs sont couplés par un transducteur électrostatique. Cette thèse étudie l'amélioration des performances des REV par la conception optimisée de leur interface électrique. La première partie de cette thèse étudie une famille d'interfaces électriques appelées pompes de charge (PC). On commence par la construction d'une théorie formelle des PC. Des interfaces rapportées dans la littérature sont identifiées comme membres de cette famille. Cette dernière est ensuite complétée par une nouvelle topologie de PC. Une comparaison des différents PC est alors faite dans le domaine électrique, puis un outil semi-analytique est présenté pour la comparaison des PC en prenant en compte le couplage électromécanique. L'étude des PC se termine par la présentation d'une nouvelle méthode de mesure du potentiel d'électret des REV. La deuxième partie de la thèse présente une approche de conception radicalement différente de ce qui est présenté dans les travaux actuels sur les REV. Elle préconise une synthèse active de la dynamique de la masse des REV à travers leur interface électrique. Nous montrons d'abord que cela permet la conversion d'énergie en quantités proches des limites physiques, et ce à partir de vibrations d'entrée de forme arbitraire. Enfin, une architecture pour un tel REV est proposée et testée en simulation. / Electrostatic vibration energy harvesters (e-VEHs) are systems that convert part of their surroundings' kinetic energy into electrical energy, in order to supply small-scale electronic systems. Inertial E-VEHs are comprised of a mechanical subsystem that revolves around a mobile mass, and of an electrical interface. The mechanical and electrical parts are coupled by an electrostatic transducer. This thesis is focused on improving the performances of e-VEHs by the design of their electrical interface. The first part of this thesis consists in the study of a family of electrical interfaces called charge-pumps conditioning circuits (CPCC). It starts by building a formal theory of CPCCs. State-of-the-art reported conditioning circuits are shown to belong to this family. This family is then completed by a new CPCC topology. An electrical domain comparison of different CPCCs is then reported. Next, a semi-analytical tool allowing for the comparison of CPCC-based e-VEHs accounting for electromechanical effects is reported. The first part of the thesis ends by presenting a novel method for the measurement of e-VEHs' built-in electret potential. The second part of the thesis presents a radically different design approach than what is followed in most of state-of-the-art works on e-VEHs. It advocates for e-VEHs that actively synthesize the dynamics of their mobile mass through their electrical interface. We first show that this enables to convert energy in amounts approaching the physical limits, and from arbitrary types of input vibrations. Then, a complete architecture such an e-VEH is proposed and tested in simulations submitted to human body vibrations.

[pt] Com a implantação do novo modelo econômico nos sistemas de potência, a justa remuneração das empresas provedoras de serviços ancilares tem se tornado um assunto grande importância. O suporte de potência reativa, por se tratar também de um serviço ancilar, está inserido neste contexto. Desta forma, a factível identificação dos agentes beneficiários pelo suporte, bem como as proporções deste beneficiamento podem implicar em um mecanismo viável de remuneração para os custos de cada fonte provedora. Este trabalho apresenta um método de alocação de custos pelo suporte de potência reativa baseado nos princípios fundamentais da teoria de circuitos elétricos, buscando determinar a contribuição de potência reativa de cada fonte para cada barra de carga. Para isto, é sugerida uma modelagem de fontes de tensão, que permite levar em conta a natureza local da relação Q-V, proporcionando uma abordagem simples e clara do problema. Complementarmente é apresentado um método de alocação das perdas reativas em cada ramo de transmissão entre as fontes provedoras de potência reativa. Para validar o método proposto, são realizados testes em sistemas de potência de pequeno e médio porte, apresentado as parcelas de contribuição de cada fonte de potência reativa para cada carga, e adicionalmente para as perdas reativas em cada ramo de transmissão. Comparações são estabelecidas com um método existente, onde é constatado que o método proposto apresenta maior coerência com as propriedades elétricas dos sistemas de potência, destacando-se a verificação clara da natureza local do consumo de potência reativa. Em relação aos resultados da alocação de perdas reativas, verifica-se que o método serve como indicativo sobre o uso da rede de transmissão por parte de cada fonte de potência reativa. / [en] After implantation of power systems` new economic model, a fair remuneration strategy of ancillary services suppliers had became an important issue. Reactive power support is also an ancillary service, thus, it belongs to this context. Then, identification of service beneficiaries as well as the benefit proportions may take a feasible remuneration mechanism for each source. This work presents a reactive power support cost allocation method based on fundamental principles of circuit theory, where reactive power contribution from each source to each load is calculated. This method suggests a modeling of voltage sources, which takes into account the Q-V relationship, providing a simple and clear treatment of the problem. Additionally, a reactive loss allocation method to each branch is presented. To validate the proposed method, tests with small and medium size systems are realized. So, there are presented results of reactive power demand and transmission losses allocation into systems` sources. Comparisons with an existent method are established, when we can verify that the proposed method brings more coherence with the electrical properties of power systems and the local nature of reactive power consumption. In the other hand, results of reactive losses allocation can indicate the transmission network usage by each reactive power source.

This thesis is focused on development of models and modelling of a wave energy converter in operation. Through the thesis linear potential wave theory has been used to describe the wave-buoy interaction. The differences lie in the generator models, in the simplest model the generator is a mechanical damper characterized by a damping factor. In the most advanced generator model the magnetic fields is calculated the by a FE-method, which gives detailed description of the electric properties and the effect it has on the buoy dynamics. Moreover, an equivalent circuit description of the generator has been tested. It has the same accuracy as the field based model but with a strongly enhanced CPU time. All models are verified against full scale experiments. The models are intended to be used for design of the next generation wave energy converters. Further, the developed models have also been used to study what effect buoy geometry and generator damping have on the ability to energy absorption. In the spring 2006 a full scale wave energy converter was installed at the west coast of Sweden. It was in operation and collected data during three months. During that period the load resistance was varied in order to study the effect on the energy absorption. These collected data was then used in the verification of the developed models. In the year 2002 a wave energy project started at Uppsala University; this work is a part of that larger project which intendeds to develop a viable wave energy conversion concept.

This thesis examines the impact of Social Credit in North America during the Great Depression as a social philosophy and approach to government. By placing Social Credit in the context of interwar social movements for monetary reform, the events in Alberta from 1932 to 1938 are examined from the historical geographic iteration of what I call the Keynesian frontier of monetary macro-economic thought. This thesis shifts attention on this episode of Canadian history towards the lens of monetary neutrality. I argue that the Keynesian frontier was the intellectual environment for a worldwide English- speaking progressive underground which sought to find in macro-economic theory a vision of utopian society where money had no effect on material choices and interpersonal relations. During the 1930s, movements such as Social Credit transformed this underground into a collective effort to integrate the institutional channels of circulation with the mechanics of the modern monetary and fiscal state.

This thesis examines the impact of Social Credit in North America during the Great Depression as a social philosophy and approach to government. By placing Social Credit in the context of interwar social movements for monetary reform, the events in Alberta from 1932 to 1938 are examined from the historical geographic iteration of what I call the Keynesian frontier of monetary macro-economic thought. This thesis shifts attention on this episode of Canadian history towards the lens of monetary neutrality. I argue that the Keynesian frontier was the intellectual environment for a worldwide English- speaking progressive underground which sought to find in macro-economic theory a vision of utopian society where money had no effect on material choices and interpersonal relations. During the 1930s, movements such as Social Credit transformed this underground into a collective effort to integrate the institutional channels of circulation with the mechanics of the modern monetary and fiscal state.

This thesis examines the impact of Social Credit in North America during the Great Depression as a social philosophy and approach to government. By placing Social Credit in the context of interwar social movements for monetary reform, the events in Alberta from 1932 to 1938 are examined from the historical geographic iteration of what I call the Keynesian frontier of monetary macro-economic thought. This thesis shifts attention on this episode of Canadian history towards the lens of monetary neutrality. I argue that the Keynesian frontier was the intellectual environment for a worldwide English- speaking progressive underground which sought to find in macro-economic theory a vision of utopian society where money had no effect on material choices and interpersonal relations. During the 1930s, movements such as Social Credit transformed this underground into a collective effort to integrate the institutional channels of circulation with the mechanics of the modern monetary and fiscal state.