| 1. |
- Francisco, Francisco, 1985-
(författare)
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Adapting sonar systems for monitoring ocean energy technologies
- 2018
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- The global energy sector is under profound reforms aiming towards renewable energy sources, clean technologies and expansion of smart grids, all with the additional aim of providing affordable and dependable electricity for everyone. A reduction of carbon dioxide emissions is a priority on the global agenda, and to achieve that, cleaner energy technologies has to be more integrated into the energy mix. This thesis focus on a sustainable implementation of wave, tidal and offshore wind power, wherefore there is a need to investigate more about the prerequisites and consequences ocean energy can have on the marine environment. For that, reliable, cost effective and continuous environmental monitoring framework is necessary in order to support and safeguard ocean energy operations.The main objectives of the research presented in this thesis are to develop a multifunctional environmental monitoring platform based on sonar systems for ocean energy applications, by adapting high resolution multibeam, dual beam and split beam sonar systems and also underwater cameras; Propose data acquisition and processing protocols capable of decipher sonar data in order to provide continuous environmental monitoring and reporting; Conduct qualitative and quantitative observations of fish and marine mammals using the built monitoring platform; And investigate the feasibility of utilizing the Uppsala University wave energy converter technology to generate electricity worldwide. As a result, a multifunctional platform was designed, built and tested. This included the hardware, the data acquisition system, and a data analysis framework comprising new algorithms necessary to process the new acoustic data. The multibeam, dual beam, and split beam sonar systems and underwater cameras produced both qualitative and quantitative data of biomass, occurrence and behavior of fish and marine mammals in the vicinity of ocean energy devices. With this platform, it was also possible to conduct seabed and structural inspections within ocean energy devices, observe cavitating flows, etc. One of the most important results of this research was the possibility of extracting visual signatures of fish and marine mammals through acoustic images. This can be valuable for training algorithms for manual or automatic identification and classification of underwater targets through imaging sonar systems, a technique that can be widely used in the offshore activities. Regarding feasibility studies and wave power resource assessment, this study concluded that mild wave climates can provide enough energy to run reverse osmosis desalination systems as well as produce sufficient electricity to integrate into a national grid.In summary, this thesis concludes that the implementation of ocean energy can be facilitated by creating environmental monitoring, risk and resource assessment frameworks such as the presented research work that contribute to lowering the risks associated with subsea work and thereby costs of ocean energy projects.
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| 2. |
- Håkansson, Jan, Professor, 1959-, et al.
(författare)
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Utmärkt lärare : Forskningen om lärarskicklighet och vägarna dit
- 2023. - 1
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Bok (populärvet., debatt m.m.)abstract
- Vad utmärker skickliga lärare? Går det verkligen att objektivt bedöma frågan utan att hamna i subjektiva värderingar och preferenser? Hur ser vägarna till lärarskicklighet ut och vad kan forskningen bidra med för svar?Då lärarskicklighet är den enskilt mest betydelsefulla faktorn för att nå goda elevresultat är frågan om vad som kännetecknar en utmärkt lärare central. Utmärkt lärare bygger på författarnas genomgång av de senaste tjugo årens svenska och internationella forskning om såväl yrkesutveckling som lärarkompetens och visar vilka kvaliteter som kännetecknar lärarskicklighet.Genom olika perspektiv och exempel utreds även forskningens svar på vad som bör göras för att tillgodose behovet av lärare och skapa förutsättningar för en ständigt pågående yrkesutveckling. De sammantagna resultaten ger forskningsgrundade målbilder och stakar ut vägen för att få fler att utvecklas till skickliga lärare genom lärarutbildning, kollegialt lärande, kompetensutveckling och professionsprogram. Fem slutsatser ger riktningen för framtiden.Utmärkt lärare ingår i den så kallade Utmärktserien och vänder sig till blivande och verksamma lärare, men också till rektorer, skolchefer, skolutvecklare, politiker, beslutsfattare och andra med intresse för att utveckla skolans kvalitet och måluppfyllelse.Tidigare utgivna böcker i serien är: Utmärkt undervisning (2020), Utmärkt skolutveckling (2016), samt Utmärkt ledarskap i skolan (2018).
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| 3. |
- Waters, Rafael, 1978-
(författare)
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Energy from Ocean Waves : Full Scale Experimental Verification of a Wave Energy Converter
- 2008
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- A wave energy converter has been constructed and its function and operational characteristics have been thoroughly investigated and published. The wave energy converter was installed in March of 2006 approximately two kilometers off the Swedish west coast in the proximity of the town Lysekil. Since then the converter has been submerged at the research site for over two and a half years and in operation during three time periods for a total of 12 months, the latest being during five months of 2008. Throughout this time the generated electricity has been transmitted to shore and operational data has been recorded. The wave energy converter and its connected electrical system has been continually upgraded and each of the three operational periods have investigated more advanced stages in the progression toward grid connection. The wave energy system has faced the challenges of the ocean and initial results and insights have been reached, most important being that the overall wave energy concept has been verified. Experiments have shown that slowly varying power generation from ocean waves is possible.Apart from the wave energy converter, three shorter studies have been performed. A sensor was designed for measuring the air gap width of the linear generator used in the wave energy converter. The sensor consists of an etched coil, a search coil, that functions passively through induction. Theory and experiment showed good agreement.The Swedish west coast wave climate has been studied in detail. The study used eight years of wave data from 13 sites in the Skagerrak and Kattegatt, and data from a wave measurement buoy located at the wave energy research site. The study resulted in scatter diagrams, hundred year extreme wave estimations, and a mapping of the energy flux in the area. The average energy flux was found to be approximately 5.2 kW/m in the offshore Skagerrak, 2.8 kW/m in the near shore Skagerrak, and 2.4 kW/m in the Kattegat.A method for evaluating renewable energy technologies in terms of economy and engineering solutions has been investigated. The match between the technologies and the fundamental physics of renewable energy sources can be given in terms of the technology’s utilization. It is argued that engineers should strive for a high utilization if competitive technologies are to be developed.
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| 4. |
- Wåhlin Larsson, Britta, 1959-
(författare)
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Skeletal muscle in Restless legs syndrome (RLS) and Obstructive sleep apnoea syndrome (OSAS)
- 2009
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Restless legs syndrome (RLS) and Obstructive sleep apnoea syndrome (OSAS) are two sleep disorders that affect daily life with symptoms such as sleepiness and fatigue. It was therefore hypothesised that the skeletal muscle could be affected as symptoms from skeletal muscle are common. The overall aim of the thesis was to investigate aerobic capacity and structure of skeletal muscle in patients with OSAS and RLS and an age matched control group to provide information regarding the underlying mechanisms. The specific aims were to investigate muscle fibre composition, capillary network, capillary proliferation and sings of local inflammation in musculus tibialis anterior of RLS and OSAS.OSAS and RLS patients had a significantly lower predicted VO2 max expressed in ml/min/kg compared with the control group and in the OSAS group apnoes-hyponea index (AHI) was inversely correlated to maximal oxygen uptake Fibre type composition and muscle fibre cross sectional area in the tibialis anterior muscle was equal in all groups with a predominant proportion of slow type I fibres and a smaller fibre area in slow type I fibres compared to fast type II fibres. The distribution of fast fibres (I/IIA, IIA) did not differ except for the group IIX and IIA/IIX where OSAS and RLS had a significantly higher percentage. OSAS patients had a significantly higher number of capillaries per fibre (CAF) for slow type I fibres and CAF per fibre area (CAFA) for fast type II fibres. CFPE- index (capillary to fibre perimeter exchange) and LC/PF-index (length of capillary/perimeter of fibre) were higher in both patient groups. Vascular endothelial growth factor (VEGF) and proliferating endothelial cells were analysed by double-immunofluorescence staining and were presented to a greater extent in the patient groups compared with the healthy controls. Based on normal amounts of T-cells and macrophages in the histological picture it was also demonstrated that local inflammation was not present in the tibialis anterior muscle of RLS and OSAS whish was also supported by the absence of expression of major histocompatibility complex class I molecules (MHC class I) on the surface of the tibialis anterior muscle fibres.In conclusion, the low predicted VO2 max together with higher percentage of type IIX and IIA/IIX muscle fibres indicates a low central capacity in the patient groups. The increased capillary network and the absence of inflammation indicate the occurrence of local hypoxia in tibialis anterior muscle in patients OSAS and RLS.
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| 5. |
- Bender, Anke, et al.
(författare)
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Colonisation of wave power foundations by mobile mega- and macrofauna - a 12 year study
- 2020
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Ingår i: Marine Environmental Research. - : Elsevier BV. - 0141-1136 .- 1879-0291. ; 161
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Tidskriftsartikel (refereegranskat)abstract
- Environmental impacts from wave energy generators on the local mobile mega- and macrofauna community have been investigated in the Lysekil project by Uppsala University. Offshore renewable energy installations provide hard, artificial substrates, and as such, they could act as artificial reefs. Foundations with manufactured holes served as complex habitats and foundations without served as non-complex. In this long-term study, SCUBA surveys of mobile fauna in the years 2007, 2008 and 2016-2019 were analyzed. The results show a distinct reef effect on the foundations with significant greater species richness, total number of individuals, greater values of the Shannon-Wiener biodiversity index, and greater abundance of specific reef fauna. Complex foundations accommodated a greater abundance of brown crabs than non-complex foundations, other taxa did not show differences between the two foundation types. A successional increase of species richness, numbers of individuals and Shannon-Wiener biodiversity could be revealed from the first to the second survey period. Inter-annual variation was visible throughout all taxa and years.
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| 6. |
- Bender, Anke, et al.
(författare)
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Effects of a Wave Power Park with No-Take Zone on Decapod Abundance and Size
- 2021
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Ingår i: Journal of Marine Science and Engineering. - : MDPI. - 2077-1312. ; 9:8, s. 864-
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Tidskriftsartikel (refereegranskat)abstract
- Past studies have revealed higher levels of biodiversity, total abundance, and size ofindividuals around offshore installations of renewable energy. This study investigated the effectsof Lysekil wave power park (area 0.5 km2) on the abundance and carapace size of decapods at theSwedish west coast. For that purpose, decapods were caught with cages during four consecutivesummers. Two types of cages were applied to catch a wide range of decapod species and sizes. Theabundance and size of decapods were not significantly different within the wave power park and upto a distance of 360 m outside of it. The catch rate, i.e., number of decapods caught in 24 h, was notsignificantly different among sampling locations but revealed inter-annual variation for both cagetypes. The results suggest a limited role of the incidental no-take zone of the small Lysekil wavepower park on the abundance and size of local decapods. However, neither were negative impacts,such as decreasing abundances or smaller carapace sizes, discovered. As an increase in the numberof marine renewable energy production sites is foreseen, a scaled-up and larger study addressingMPA networks and other environmental interactions should be considered.
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| 7. |
- Bender, Anke
(författare)
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Environmental Effects from Wave Power : Artificial Reefs and Incidental No-take Zones
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Marine renewable technologies have rapidly been developing over the past decade. Wave power is one of the renewable sources and has the potential securing the renewable electricity production. However, all renewable energy extraction affects the environment in some way and for a true sustainable energy generation, environmental effects need to be investigated. Beside uncertain effects from the technologies to habitats or organisms e.g., collision risks, electromagnetic fields, noise, past studies have also shown benefits on diversity, size and abundance of species around marine renewable technologies as a result of habitat creation by the devices and fishery exclusion in designated offshore park areas.This thesis deals with environmental effects from heaving point-absorber wave energy converters developed at Uppsala University and deployed on the Swedish west coast at the Lysekil research site and the Sotenäs Project wave power park over a period of four years. The scope was the investigation of artificial reef effects from wave power foundations on local mobile, mega and macrofauna during visual inspections using scuba diving on the first hand. On the second hand, the effects from the incidental no-take zone on decapods and two sea pen species were investigated applying cage fishing and ROV seabed surveys. A third focus was on environmental monitoring around MRE sites and monitoring of MRE installations, both in an experimental and theoretical approach.In the Lysekil research site, the results highlight that abundance and diversity can be enhanced locally around wave power foundations compared to control areas. The abundance and size of decapods were not significantly different within the wave power park and up to a distance of 360 m outside of it. In the Sotenäs Project wave power park a positive effect on Nephrops norvegicus size and burrow density but not on abundance was found on a scale of up to 1230 m. Sea pen abundance was enhanced inside the wave power park. However, interannual variation was strong.In conclusion, wave power foundations can influence abundance and diversity of marine organisms around foundations on a very local scale (meters). With the methods in this study, the investigations did not reveal strong effects on the abundance and size of decapods on a larger scale up to 1230 m away from foundations as a result of the no-take zone. However, a focus should be put on a further development of environmental monitoring routines around MRE sites and their evaluation.
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| 8. |
- Bender, Anke, et al.
(författare)
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Imaging-sonar observations of salmonid interactions with a vertical axis instream turbine
- 2023
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Ingår i: Rivers Research and Applications. - : John Wiley & Sons. - 1535-1459 .- 1535-1467.
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Tidskriftsartikel (refereegranskat)abstract
- Anthropogenic activities and their influences on aquatic systems is an important topic, especially considering the growing interest in using the earth's resources in a sustainable way. One of those anthropogenic activities is the introduction of renewable technologies into the aquatic environment such as instream turbines. Environmental studies around those technologies are often still ongoing due to their novelty. During the spring of 2018, juvenile individuals of two salmonid species, Atlantic salmon and brown trout were released upstream a vertical axis instream turbine in the river Dal (Dalälven) in eastern Sweden. The aim of this study was to investigate the swimming behavior of the salmonids around a small-scale prototype vertical axis instream turbine. The swimming pattern and the possible response of avoiding the vertical axis instream turbine were documented with a multi beam sonar. A control area, next to the turbine, was used as reference. No consistent results were shown for trout as they were passing the control area with a statistically high variation, and specimens were rarely observed in proximity of the turbine, neither if the turbine was operating nor at stand still. Salmon clearly avoided the operating turbine, but did not avoid the turbine when it was at stand still, and was often observed swimming straight through the turbine area. These findings indicate that operating this type of instream turbine in a river affects the swimming behavior of Atlantic salmon but is unlikely to affect its migration paths. For brown trout, the statistical results are inconclusive, although data indicate a response of avoiding the turbine. The species are in little risk to suffer physical harm as no fish entered the rotating turbine, despite very turbid water conditions.
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| 9. |
- Bolin, Niklas, 1977-
(författare)
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Målsättning riksdagen : Ett aktörsperspektiv på nya partiers inträde i det nationella parlamentet
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- During much of the 20th century, the national party systems of Western Europe remained largely unchanged. However, beginning in the 1970s, these frozen party systems slowly started to melt. As the number of parties has increased, the question of what explains new party entrance has also attracted more scholarly interest. Despite this increased attention, the study of new political parties still suffers from a structuralist bias. The implication is that the fates of new parties are decided almost exclusively by external factors. Some scholars focus on the institutional environment; others emphasize sociological explanations, such as the formation of new cleavages in society. Yet such non-actor-centred perspectives risk being excessively deterministic. They also struggle to explain why some parties succeed in gaining entrance to legislatures while others, seemingly under the same external circumstances, fail. In this thesis, therefore, a new way to study parties and their path to parliament is proposed. Starting with the notion that external conditions alone cannot explain new party entrance, the thesis takes an agency-based perspective. Three sets of strategies are identified as being important means for a party to influence its chances of getting into parliament. They concern the party's resources, its political project and its external relations. In what ways can supply and management of resources, policies and relations with other parties affect the potential for becoming a parliamentary party? Through four in-depth case studies of new entrants into the Swedish national parliament, the Riksdag, the thesis concludes that there are some important commonalities in their paths to parliament. Especially with regard to their resources and their political project, the empirical evidence supports the initial premise: new party entrance is unthinkable without successful strategic behaviour.
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| 10. |
- Forslund, Johan, 1985-
(författare)
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Experimental Results of a Load-Controlled Vertical Axis Marine Current Energy Converter
- 2015
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis investigates the load control of a marine current energy converter using a vertical axis turbine mounted on a permanent magnet synchronous generator. The purpose of this thesis is to show the work done in the so far relatively uncharted territory of control systems for hydro kinetic energy conversion. The work is in its early stage and is meant to serve as a guide forfuture development of the control system.An experimental power station has been deployed and the first results are presented.A comparison between three load control methods has been made; a fixedAC load, a fixed pulse width modulated DC load and a DC bus voltage control of a DC load. Experimental results show that the DC bus voltage control reduces the variation of rotational speed with a factor of 3.5. For all three cases, the tip speed ratio of the turbine can be kept close to the expected optimal tip speed ratio. However, for all three cases the average extracted power was significantly lower than the average power available in the turbine times the estimated maximum power coefficient. A maximum power point tracking system, with or without water velocity measurement, should increase the average extracted power.A simulation model has been validated using experimental data. The simulated system consists of the electrical system and a hydrodynamic vortex model for the turbine. Experiments of no load operation were conducted to calibrate the drag losses of the turbine. Simulations were able to predict the behaviour in a step response for a change in tip speed ratio when the turbine was operated close to optimal tip speed ratio. The start position of the turbine was varied in the simulation to view the influence on the step response from a changed turbine position relative to the direction of the water flow.
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