To be in line with the Paris Agreement and mitigate average temperature rise to 1.5°C, and to a maximum of 2°C, greenhouse gas emissions will have to be reduced close to zero before mid-century. If these targets are to be reached, rapid and complete decarbonisation of every sector within the global economy is required. Currently, energy-intensive industrial sectors account for more than 30% of global energy use, and are responsible for approximately 50 % of global greenhouse gas emissions, whereas the iron and steel industries have the largest aggregated greenhouse gas emissions globally. Although the steel industry is at the cusp of major climate neutrality transitions, as recent studies have presented opportunities of producing completely fossil-free steel, decarbonising large-scale production processes is a complex query affected by a multitude of internal and external factors. Höganäs AB, as one of the largest powder metal manufacturers in Sweden, has initiated their work towards net-zero emissions in 2045. With production sites in over 18 countries, the company serves as an example of a company in the midst of turning a “hard-to-abate” industry towards being sustainable.  The aim of this study is thus to assess the effects of climate agendas and frameworks, such as the Paris Agreement and the IPCC Report on initiatives and policies on a global, national and regional level within countries where Höganäs AB has its major production facilities. The aim is further to review the effects of climate strategies and targets on the steel and powder metal industry, as well as to monitor the industry’s inclinations towards climate neutrality. The findings of the performed literature study, as well as the conducted qualitative interviews, resulted in a framework regarding how to identify and assess trends within the steel and powder metal industry based on two theoretical perspectives on corporate climate transitions. Through the results, it could be concluded that despite all countries having ratified the Paris Agreement as of January 2021, no country is currently on the path towards reaching the 1.5°C target that is recommended by the IPCC Report and the Paris Agreement. Still, there is a growing demand for low-carbon technology and renewable energy in every country, something that will partly weigh up for both up-scaled industrial production and countries’ increased GDP. Within the industry, an increased number of initiatives and commitments has been launched during the past few years, indicating that questions of climate change and sustainability are being entrenched in the corporate sector. Going forward, indicators to measure continuous improvements to reach net-zero are associated with emission- and energy data, value chain management and industry investments. As technological advancements towards hydrogen, electrification and digitalisation are being upscaled and increasingly tangible, climate neutrality in the PM and steel industry is achievable through a profound and intended climate focus and an increased sense of urgency.

The need for renewable energy sources is evident. The worlds energy economy need to change rapidly to stopthe climatological changes. The ratio between renewables and fossil fuels, or an energy economy only based onrenewables, is based on political choices. The surface footprint of renewables is significantly larger thantraditional power plants. For a successful implementation social obstacles and sustainable impact need to beevaluated along with sufficient energy in the renewable source and the possibility to deliver the energy tocustomers. Grid stability, self-sufficiency and energy independence are major struggles for small countries withhigh population density, limited renewable sources and limited areas for harvesting the energy in thesesources. The future Dutch energy economy depends on wind and solar energy, along with hydrogen productionfor energy storage and grid stability.The focus of this study is the challenge to implement solar field without compromising other sustainabilitygoals or provoking social obstacles. The potential of integrating solar energy with road areas is explained. Theseareas could become large energy plants and the potential is the motive for this study. It is explained why roadsneed to be implemented in the energy economy as production zones and the reasoning is substantiated withdesk study and calculations.The desk study contains explanation of methods for harvesting energy with roads or roadside areas, followedby the explanation of possible electrolyzing techniques to store the solar energy. Solar calculations are madeand it is explained how the input data for these calculations are obtained, in particular how to calculate diffuseirradiation when this data is not available. The total efficiency of the hydrogen production and storage processis evaluated and insight is given of current energy demand for electrical driven vehicles (EV) and fuel cell drivenvehicles (FCEV).The paper is written with a strategic sustainable development perspective. The future objectives are analysed,current situation and the gap is determined, possible steps are considered and a strategic solution is delivered.The results of this study prove the possibility to create energy neutral roads with solar systems build over theroad and hydrogen generation with PEM electrolysers to store energy. The produced energy, harvested withthe road areas can supply enough energy to meet the energy demand of 50 000 vehicles that use the A6 everyday between Swifterband and Almere (Oostvaarders).

This dissertation is the result of research and development of a power conditioning system for Superconductive Magnetic Energy Storage System. The dominant challenge of this research was to develop the power conditioning system that can match slowly varying dc voltage and dc current on the super conductive magnet side with the ac voltages and ac currents on the utility side. At the same time the power conditioning system was required to provide a bi-directional power flow to the superconductive magnet. The focus of this dissertation is a three-level diode clamped dc-ac converter which is a principle part of the power conditioning system. Accordingly, this dissertation deals with the space vector modulation of three-level converters and introduces a computationally very efficient three-level space vector modulation algorithm that is experimentally verified. Furthermore, the proposed space vector modulation algorithm is successfully generalized to allow equally efficient, real time implementation of space vector modulation to dc-ac converters with virtually any number of levels. The most important advantage of the proposed concept is in the fact that the number of instructions required to implement the algorithm is almost independent from the number of levels in a multilevel converter. More on the side of the control of multilevel converters, the particular attention in this dissertation is paid to the problem of charge balance in the split dc-link capacitors of three-level neutral-point-clamped converters. It is a known fact that although the charge balance in the neutral point can be maintained on a line cycle level, a significant third harmonic current flows into the neutral point for certain loading conditions, causing the neutral point voltage ripple. The logical consequence of that ripple is the deteriorated quality of the output voltage waveforms as well as the increased voltage stress on the switching devices. This was the motivation to more carefully explore the loading conditions that cause the unbalance, as well as to study the fundamental limitations of dc-link capacitor charge balancing algorithms. As a part of that work, a new model of the neutral point current in the rotating coordinate frame is developed as a tool in investigation of theoretical limitations and in providing some intuitive insight into the problem. Additionally, the low frequency ripple is quantified and guidelines are offered that can help size the dc-link capacitors. Because the study of the neutral point balance identified the loading conditions, that under some possible system constraints, cause an unavoidable neutral point voltage ripple, a feed forward type of control method is developed next. The proposed feed forward algorithm can effectively prevent the neutral point voltage ripple from creating distortions in the converter output voltage under all loading conditions and without causing additional disturbance in the neutral point voltage. The feed forward method is developed for a sine triangle as well as for the space vector type PWM algorithm. The simulation results that include the full dynamic model of the converter and load system validate the feed forward approach and prove that the feed forward algorithm can effectively compensate the effect of the neutral point voltage ripple. The simulation results are than experimentally verified. / Ph. D.

In this dissertation, we study the effects of emerging biomass markets on land use changes between alternatives of agricultural production, conventional timber production, and forest woody biomass production for energy use. Along with the uncertainty associated with woody biomass prices and rents, transaction costs incurred to land use play an important role in land allocation decisions and make this study distinct from other work. In Chapter 1, we introduce the background and objectives of our study. In Chapter 2, we analyze the behavior of a risk-neutral private landowner and social planner under uncertainty of woody biomass prices, assuming that there is a market emergence at some unknown time point in the future. Market emergence is characterized by a price jump and a certain timing of the price jump. Six different price jumps and five different timings of bioenergy market emergence are adopted to study their collective effects on land use change between agriculture and forestry. Chapter 3 studies this problem for a risk-averse private landowner. Two measures of relative risk aversion are used to examine how a landowner's preference may affect his or her land use decision. In Chapter 2, we find that, for three different quality categories of land, land rents from forestry increase significantly for higher price jumps and decreases in the length of time until bioenergy market emergence. One of the most important results is concerned with the presence of transaction costs. Here, we find that these costs may require unrealistic market emergence scenarios to lead to bioenergy adoption on any large scale. This result is even more likely with nonlinear transaction costs. Land allocation decisions in Chapter 3 are distinctly different from those in Chapter 2, due to the introduction of landowner risk aversion. In certain market emergence cases, some land units retain in agriculture entirely when the landowner is risk averse . The Chapter 4 studies a stochastic optimization problem of land use, assuming that woody biomass rents follow a stochastic diffusion called geometric Brownian motion that is later discretized by a binomial option pricing approach. The problems in Chapters 2 and 3 assume that the landowner must make all decisions at the beginning of his or her time horizon. This assumption is relaxed in Chapter 4. Now, the landowner is allowed to revise his or her land allocation decision among three alternatives over time as information about market emergence is collected. We observe that the different forms of transaction costs are not as significant as in Chapters 2 and 3. However, different values of volatility of forest biomass rents give rise to different land allocation decisions, especially for the land of high quality. / Ph. D.

There currently exists no reliable, non-destructive method for measuring stress in railroads and other similar structures without the need for a calibration measurement. Major limitations which have hindered previous techniques include sensitivity to boundary conditions, insensitivity to stress, and intolerance for material and geometry uncertainty. In this work, a technique is developed which seeks to solve these challenges by extracting the spectrum relation, or dispersion curve, of a waveguide from dispersive wave propagation meaasurements. The technique is based on spectral analysis of waves in structures modeled as beams, and as such is based on relatively low frequency vibrations, as opposed to other techniques which use nonlinear elastic modeling of structures at ultrasonic frequencies. The major contribution of this work is the development of a frequency-domain based signal processing technique which is capable of compensating for the dispersive, long wavelength reflections which have limited the ability of previous techniques to go low enough in frequency to achieve high stress sensitivity. By compensating for reflections, the present work is able to automate the process of analyzing wave propagation signals such that the entire dispersion curve can be extracted, enabling the identification of various parameters including stress, stiffness, density, and other material and geometry properties. This in turn enables measuring stress, performing model-updating for material and geometry uncertainty, and being indifferent to boundary conditions. The theory and algorithmic implementation is presented, along with simulations and experimental validation on a rectangular beam. / Master of Science / The ability to detect damage or the potential for damage in structures is highly desirable, especially in industries such as civil infrastructure in which failure can be incredibly costly and dangerous. In particular, non-destructive techniques which can predict failure without interfering with the operations of a structure are particularly sought after. In this work, a technique for non-intrusively and non-destructively measuring stress is developed, with the primary application being for measuring stress in railroads. The technique seeks to advance the state-of-the-art in wave-propagation-based techniques by adding the capability to automatically identify reflected waves. With this new capability, the method is able to quickly and efficiently analyze a large set of vibration measurements to extract information about the structure's material, geometry, and loading characteristics which enables solving for stress even when the structures material, geometry, and boundary conditions are not precisely known. The technique is demonstrated on both simulated and experimental data, in which a rectangular beam is tensioned and the stress is then identified.

Slurs are offensive words used about people on account of them belonging to certain groups,for example based on gender, sexual orientation or ethnicity. The topic of slurs has interestedphilosophers of language recently, and there are several theories trying to explain them. Mostassume that slurs have Neutral Counterparts, non-offensive words that can be used more or lesssynonymously with certain slurs. In this thesis I attempt to construct a theory of slurs withoutneutral counterparts. First, I give a background where I explain extension, content and neutralcounterparts. Then I describe popular theories about how slurs offend. After that I summarizeAlice Damirjian’s critique against neutral counterparts in her article “Rethinking slurs”. Againstthis background I explain my theory of slurs; slurs lack neutral counterparts, and they refer toentirely different classes than so called “neutral counterparts” do. Instead, slurs refer nonphysical sociocultural constructions, while “Neutral counterparts” refer to physical people.While the relation between slurs and “neutral counterparts” is non-semantic, it is pragmatic;there is a widespread misconception that slurs and “neutral counterparts” are more or lesssynonymous. Slurs offend since their sociocultural constructions are associated withstereotypes that are attributed to the people that their so called “neutral counterparts” refer to.After I explain my theory I respond to counterarguments, and the thesis is concluded with asummary.

Historically, disenfranchised students in the American education system have been promised opportunity through successful participation in the school system. These promises are voiced in legislation like the Elementary and Secondary Education Act of 1965 and by executive actions like President Obama’s Race to the Top Initiative. Evidenced by the continuing education gap, the promises of success through education continue to evade many American children across the nation, especially students who are most in need of the support promised in these quixotic visions of opportunity. This is a qualitative interview study that aimed to gather the voices of educators involved in the implementation of the English Language Arts Common Core State Standards (ELA CCSS) to investigate the potential benefit of an information loop during the time period Bridges (2009) labeled the Neutral Zone, a period when change agents can reflect on and possibly enhance the implementation of an initiative. The study aimed to answer the following research question: What are the experiences of teachers, school principals, and district-level administrators during the transition to the ELA CCSS in three public school districts in the greater Los Angeles area? The narratives constructed throughout the interview process with the study’s participants point to the value of establishing an information loop during the Neutral Zone as an untapped vein of knowledge in the change process. This information can potentially be used to take inventory of the trajectory an implementation process has taken.

As wide-bandgap devices continue to experience deeper penetration in commercial applications, there are still a number of factors which make the adoption of such technologies difficult. One of the most notable issues with the application of wide-bandgap technologies is meeting existing noise requirements and regulations. Due to the faster dv/dt and di/dt of SiC devices, more noise is generated in comparison to Si IGBTs. Therefore, in order to fully experience the benefits offered by this new technology, the noise must either be filtered or mitigated by other means. A survey of various DC/DC topologies was conducted in order to find a candidate for a battery interface in a UPS system. A three-level NPC topology was explored for its potential benefit in terms of noise, efficiency, and additional features. This converter topology was modeled, simulated, and a hardware prototype constructed for evaluation within a UPS system, although its uses are not limited to such applications. A UPS system is a good example of an application with strict noise requirements which must be fulfilled according to IEC standards. Based on a newly devised mode of operation, this converter was verified to produce no common-mode voltage under ideal conditions, and was able to provide a 6 dB reduction in common-mode voltage emissions in the UPS prototype. This was done while achieving a peak efficiency in excess of 99% with the ability to provide bidirectional power flow between the UPS and battery backup. The converter was verified to operate at the rated UPS conditions of 20 kW while converting between a total DC bus voltage of 800 V and a nominal battery voltage of 540 V. / Master of Science / As material advancements allow for the creation of devices with superior electrical characteristics compared to their predecessors, there are still a number of factors which cause these devices to see limited usage in commercial applications. These devices, typically referred to as wide-bandgap devices, include silicon carbide (SiC) transistors. These SiC devices allow for much faster switching speeds, greater efficiencies, and lower system volume compared to their silicon counterparts. However, due to the faster switching of these devices, there is more electromagnetic noise generated. In many applications, this noise must be filtered or otherwise mitigated in order to meet international standards for commercial use. Consequently, new converter topologies and configurations are necessary to provide the most benefit of the new wide-bandgap devices while still meeting the strict noise requirements. A survey of topologies was conducted and the modeling, design, and testing of one topology was performed for use in an uninterruptible power supply (UPS). This converter was able to provide a noticeable reduction in noise compared to standard topologies while still achieving very high efficiency at rated conditions. This converter was also verified to provide power bidirectionally—both when the UPS is charging the battery backup, and when the battery is supplying power to the load.

No description available.

No / Based on a reduced-form model of credit risk, we explore statistical arbitrage opportunities in the CDS spreads of North American companies. Specifically, we develop a trading strategy using the model to trade market-neutral portfolios while controlling for realistic transaction costs. Empirical results show that our arbitrage strategy is of significant economic value, and also cast doubt on the efficiency of the CDS market. The aggregate returns of the trading strategy are positively related to the square of market-wide credit and liquidity risks, indicating that the market is less efficient when it is more volatile.