Publikationer från Uppsala Universitet
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Techno-economical Assessment of Battery Storage Combined with Large-Scale Photovoltaic Power Plants Operating on Energy and Ancillary Service Markets
No full textA significant challenge is to determine the specific services Battery Energy Storage System (BESS) should provide to maximize profits. This study investigates the most profitable markets and sizes of BESS with utility-scale solar Photovoltaics (PV) power plants using techno-economic analysis frameworks. The objective is to maximize profitability in energy and frequency markets, focusing on primary regulation and day-ahead markets for Sweden and Germany. The inputs are historical market prices and frequency data, as well as real measurement PV power data. The results show that adding a BESS to an existing PV park does not result in a lower payback period than if implementing a stand-alone BESS. However, the payback period differs between Sweden and Germany during 2023, i.e., being 1.8 and 6.8 years, respectively. This is explained by the lower frequency market prices for Germany compared to Sweden. The technical results indicate that the BESS energy capacity after 10 years of operation is approximately 83% for Germany, whereas, for Sweden, it is around 87%. Also, combining the operating of BESS on primary regulation and day-ahead markets showed a 6-year payback period with a slight increase in loss of energy capacity (from 83 to 80%) for Germany. Moreover, combining various PV-BESS sizes showed a discrepancy in economic and technical metrics for the BESS in Germany, resulting in a best-case of a 6-year payback period. A sensitivity analysis, which examines a drop in the frequency control prices in the future relative to 2023 (by 20% and 50% for Germany and Sweden, respectively), reveals an increase in the payback period for both countries by approximately 1 year
A fluorinated zirconium-based metal-organic framework as a platform for the capture and removal of perfluorinated pollutants from air and water
No full textA series of zirconium-based MOFs with acclaimed stability was prepared and their ability to adsorb polyfluorinated pollutants was compared. A novel fluorinated UiO-67 analogue, UiO-67-F2, was synthesised alongside three previously reported materials: UiO-67-NH2, UiO-68-(CF3)2 and UiO-67. The structures were established and confirmed by powder X-Ray diffraction. UiO-67-NH2, UiO-68(CF3)2 and UiO-67-F2 were examined as sorbents for the perfluorinated gas, sulphur hexafluoride (SF6) from the gaseous phase. The SF6 uptake of UiO-67-NH2 and UiO-67-F2 at 100 kPa, 293 K, was high (5.54 and 5.24 mmol g -1 respectively). UiO-67-F2 exhibited a remarkable perfluorinated octanoic acid (PFOA) uptake of 928 mgPFOA g -1MOF in an aqueous solution, which far exceeded that of unmodified UiO-67 (872 mgPFOA g -1MOF at 1 000 mgPFOA L -1Water PFOA). This study has identified strengths and potential applications of the novel UiO-67-F2 and the impact of fluorine functionalization. The study also offers insight into the structure-property relations of UiO-based MOFs for their use as low-pressure SF6 storage materials and PFAS sorbents intended for water purification under ambient conditions
Tracing Corruption and Leadership Failure : A Theory-Testing Process-tracing Case Study
No full textRecent research has found a relationship between the triple interaction of Chinese loans, IMF finance and executive corruption, and a higher risk of leadership failure. This paper deepens the knowledge by bridging the gap between statistical relationships and causal explanations, exploring the question to what extent do the mechanisms of exposure of corruption or restriction of corruption explain leadership failure? In an extensive analysis, I test the explanatory power of two causal mechanisms, the Corruption Exposure Mechanism (CEM) and the Corruption Restriction Mechanism (CRM), by constructing a novel framework consisting of hypotheses on three levels within the domestic context. Employing a process-tracing approach, mixed methods are used to test how domestic elites, the political opposition, and the electorate respond to corruption, in the case of the leadership failure of Malawian President Joyce Banda in 2014. The case was selected based on the presence of Chinese debt, an active IMF program, and high levels of executive corruption, presenting a context where the mechanisms are expected to operate. The results show that corruption exposure was the main operating mechanism in the studied case, particularly visible at the electorate level, but also at the oppositional and elite levels. This paper makes a theoretical contribution by presenting a novel framework of testable hypotheses for examining the causal link between corruption and leadership failure. The empirical findings also contribute to the understanding of the domestic dynamics of international finance and highlight important policy implications regarding the impacts of revealing corruption
Close encounters: electronic excitations by keV ions in single crystals
No full textThis thesis focuses on the study of ion-solid interactions, particularly at ion energies of several tens of keV. In this regime, ion beams hold technological potential for high-resolution depth profiling as well as for increased precision in ion implantation, which is paramount for applications in semiconductor manufacturing or quantum computing. The understanding of the exact nature of energy dissipation processes active during ion penetration is crucial for technological advancement but simultaneously presents a fundamental physics problem worth investigating. A widely accepted picture describing keV ion-solid interactions is the one of electronic excitations in an electron gas. Nevertheless, the experimentally accessible observables, such as energy or charge transfer, show unexpectedly clear signs of an atomic signature in the individual interaction. The origin of these processes is currently under investigation both in dedicated experiments and using novel computational approaches. The research employs ion transmission experiments through thin self-supporting single-crystalline membranes which allow for a confinement of interaction distances and thus processes. Ions experiencing close collisions with target atoms displays energy losses beyond those expected in the electron gas picture. Correlating these observations with the charge state distributions of the transmitted projectiles underscores the role of close collisions facilitating the formation of molecular orbitals. A quantitative analysis reveals this atomistic nature of the interaction being the dominant energy dissipation channel for slow, heavy ions. The Time-of-Flight Medium-Energy Ion Scattering system (ToF-MEIS) at Uppsala University was used as a primary tool for the investigations. The present work further developed this instrumentation as well as established new ion-based analytical techniques in-situ. Control over the surface composition is mandatory to yield reliable empirical data in the investigations presented in this thesis. Elastic recoil detection was shown capable of quantitative analysis of light surface contaminants, both on bulk and transmission samples. Ion-induced surface sputtering and desorption were employed on self-supporting membranes shedding light on the underlying mechanism for the desorption process. Finally, the construction and commissioning of an advanced UHV preparation chamber opened up for in-situ synthesis and modification of materials, which in combination with ToF-MEIS enables precise compositional and structural analysis at a nanometre scale.
Mål och medel : Regeringens styrning av Försvarsmakten 2012–2024
No full textHur har regeringens användning av mål vid styrningen av Försvarsmakten varierat under det senaste dryga decenniet? Vad har orsakat denna variation? I denna studie undersöker jag antalet mål och deras typsammansättning i regeringens offentliga styrdokumentation för Försvarsmakten, och försöker förklara variationen i användning av mål utifrån teorier och tidigare studier inom styrningsforskningen med syftet att utöka kunskaperna om myndighetsstyrning under perioder av förändring. Undersökningen har utförts genom att studera regleringsbrev, instruktion och inriktningsbeslut för Försvarsmakten med avseende på användningen av mål som en del i resultatstyrningen. Målen har kodats och delats in i fyra typer utifrån vad de avser: outcome-, output-, input- respektive processmål. Dessa insamlade data har sedan jämförts med Försvarsmaktens anslag samt hur många gånger myndigheten omnämnts i media, en proxy för politisk uppmärksamhet. Med hjälp av deskriptiva studier och regressionsanalys visar jag att antalet mål fluktuerat kraftigt under perioden, och att en tydligt minskande trend är synlig från och med budgetåret 2021. Jag kommer också fram till att antalet mål, inklusive för utvalda måltyper, inte samvarierar som teoretiskt förväntat med de ekonomiska anslagens storlek eller antal omnämnanden i redaktionella media. Istället genererar jag ett antal hypoteser som kan förklara resultaten. Studien bidrar med ny kunskap om hur regeringens styrning av Försvarsmakten sett ut under den säkerhetspolitiskt viktiga perioden 2012–2024 och bäddar därmed för ytterligare forskning om mekanismerna bakom styrningens utformning
Fishing for Influence : Dynamics of power in the policy making of Baltic Sea fishing opportunities
No full textIn a time where policy makers are under pressure to uncover effective solutions to environmental issues, polycentricity has sparked hope for resolving the multiple challenges of environmental change. However, as polycentric systems are showing struggles with inconsistencies and implementation failures, criticism towards the concept has begun to appear. This study addresses the critique that polycentric research overlooks the role of power by examining the policy making of Baltic Sea fishing opportunities, which is shaped by contradicting power arrangements and insufficiently assessed governance processes. The purpose is to empirically examine how actors exercise different types of power in efforts to influence the policy making process, and it is examined through the lens of a power typology framework especially designed for polycentric governance studies. By limiting its scope to the decision on 2025 fishing opportunities, and conducting a case study on Sweden, I reveal certain power dynamics, contributing to enhanced understanding and transparency in policy making on fishing opportunities. I also uncover multiple methodological challenges associated with polycentric research, questioning the applicability of the polycentric power typology. I conclude by emphasising the need for more polycentric research on power, as it is crucial for achieving effective polycentric environmental governance
Säkerhet kontra integritet : En motivanalys av målkonflikten mellan politiska beslutsfattare och gräsrotsbyråkrater om informationsplikt
No full textThis thesis investigates the trade-offs made by political decision-makers and civil servants in their decision to support the idea or oppose the proposed bill on the duty to provide information on undocumented migrants. The bill has been a controversial issue for the last two years and raises the question of how civil servants should relate to superior decision-makers in implementing decisions that go against their own beliefs. Previous research has shown that actors make a trade-off between integrity and security in conflict of interests that involve disembodied surveillance. However, research has yet to explore if this trade-off prevails in the context of embodied surveillance. Thus, the bill that would imply that civil servants would act as an extended surveillance arm of law enforcement agencies will be examined. To investigate this, a case study with a motive-analytic structure and complementary qualitative interview has been conducted to explore the underlying motives for opposition or support of the proposed bill. The results suggest that street-level bureaucrats tend to prioritize integrity over security, while Swedish political decision-makers are inclined to adapt to public opinion regarding conflict of interest when facing extensive resistance.
Explanations for the two-component spectral energy distributions of gravitationally lensed stars at high redshifts
No full textObservations of gravitationally lensed, high-mass stars at redshifts ≳1 occasionally reveal spectral energy distributions that contain two components with different effective temperatures. Given that two separate stars are involved, this suggests that both stars have simultaneously reached very high magnification, as expected for two stars in a binary system close to the caustic curve of the foreground galaxy-cluster lens. The inferred effective temperatures and luminosities of these stars are, however, difficult to reconcile with known binaries, or even with isolated stars of the same age. Here, we explore three alternative explanations for these cases: circumstellar dust around the cooler of the two stars, age differences of a few million years among stars in the same star cluster, and a scenario in which the stars originate in two separate star clusters of different age along the lensing caustic. While all of these scenarios are deemed plausible in principle, dust solutions would require more circumstellar extinction than seen in local observations of the relevant supergiant and hypergiant stars. Hence, we argue that age differences between the two stars are the most likely scenario, given the current data
Retouched Reality: Beauty, K-pop and filters in Korean Social Media : A qualitative interview study, enriched with ethnographic insights, exploring social media's role in shaping and reinforcing beauty ideals in South Korea.
No full textThis study investigates the interplay between social media and beauty ideals in South Korea, focusing on the experiences of young women. South Korea has the highest number of plastic surgeries per capita, highlighting its extreme beauty culture. The country has also been recognised for its prominence in popular culture, with K-pop idols being poster girls for the nation's beauty ideals. To explore how social media and K-pop idols influence beauty ideals and self-perception, the theoretical frameworks of mediatisation and feminist media theory are applied. Ethnographic descriptions based on our six weeks in Seoul have been included as a part of the data collection method. Furthermore, semi-structured interviews with seven South Korean women aged 18 to 30 were conducted to collect material. Their responses were analysed through thematic analysis. Nine key themes have been identified based on the following research areas: the digital constructions of beauty ideals, the impact of K-pop on beauty, managing beauty through filters and women's interpretations of beauty ideals. The findings show that beauty ideals in South Korea are heavily influenced by social media and K-pop idols. On social media platforms such as YouTube and Instagram, unattainable standards of beauty are promoted, leading to societal pressure and appearance dissatisfaction. The study highlights the need for a critical examination of the media, emphasising the importance of creating more inclusive and realistic norms to counteract the harmful effects of beauty ideals
Functionalized gold nanoflowers on carbon screen-printed electrodes : an electrochemical platform for biosensing hemagglutinin protein of influenza A H1N1 virus
No full textAn electrochemical biosensor based on modified carbon screen-printed electrodes was developed for the detection of hemagglutinin of influenza A H1N1 virus (H1). Gold nanoflowers were electrodeposited on the electrode to increase conductivity and surface area. The electrochemical signal was amplified by functionalization of the gold nanoflowers with 4-aminothiophenol, which resulted in a 100-fold decrease of the charge transfer resistance due to a tunneling effect. Subsequently, monoclonal antibodies against H1 were immobilized on the surface via covalent amide bond formation, followed by blocking with bovine serum albumin to minimize nonspecific hydrophobic binding. The electrodes were characterized by cyclic voltammetry and electrochemical impedance spectroscopy experiments in the presence of [Fe(CN)6]3-/4-. Differential pulse voltammetry was used to measure the change in current across the electrode as a function of H1 concentration. This was performed on a series of samples of artificial saliva containing H1 protein in a clinically relevant concentration range. In these experiments, the biosensor showed a limit of detection of 19 pg/mL. Finally, the biosensor platform was coupled to an automated microfluidics system, and no significant decrease of the electrochemical signal was observed