The IronArc process is a novel process for a more sustainable production of liquid pig iron using electricity for heating and hydrocarbons for reduction. This thesis aims to facilitate its use by investigating possible refractory solutions and the gas blowing in the process which is done by a plasma generator. The process involves a slag with a high FeO content of 90 wt % and gangue content of approximately 5 wt % SiO2 and 5 wt % CaO. The interaction between such a slag and refractories of MgO, Al2O3, Cr2O3, SiC, ASZ,and C was investigated by high temperature experiments at 1700 K and by thermodynamic calculations in Thermo-calc and FactSage. In the high temperature experiments it was found that all of the studied refractory materials experienced signicant wear after 3 h, but the MgO-Al2O3 spinel refractories were the least affected. The thermodynamic calculations show fair agreement to the experiments, with the exception for the Cr2O3-spinel refractory which performed much worse than predicted by thermodynamic equilibrium calculations. It was concluded that the thermodynamic equilibrium calculations in Thermo-calc and Factsage can be used as an indicator for the stability of a refractory material, but with varying accuracy depending on the quality of the data in the database used. Since industrial refractory materials are not viable as refractory for the IronArc process a freeze-lining approach was evaluated by using CFD in ANSYS Fluent. The flow of a slag was simulated through two different designs of slag runner to investigate how well a freeze-lining protects the walls in a region with rapid flow and the cooling required to form and maintain said freeze-lining. It was found that the enthalpy porosity model in ANSYS Fluent in combination with the RSM turbulence model accurately predicts the thickness of a freeze lining when validated against experiments in the CaCl2-H2O system. For optimal protection of the refractory walls the reactor and runner should be designed to minimize the movement close to the walls as high near-wall turbulence will reduce the thickness and stability of the freeze-lining, leading to greater cooling requirements to maintain afreeze-lining. The IronArc process uses a plasma generator to supply heat to the reactor using electricity. By blowing gas and hydrocarbons through an electric arc, superheated gas is formed which when injected into the reactor provides both stirring and heating for the process. To study the behavior of the injected gas a simulation model was developed in OpenFOAM. The model for simulating gas blowing was tested in both incompressible and compressible simulations in the air-water system which were veried against an experimental study in the air-water system and found good agreement. The simulations of the plasma generator blowing were done in the compressible model to account for the high temperature and pressure present in the IronArc process. It was found that the stability of the gas blowing is dependent on the Froude number where low values cause an unstable and pulsating plume and higher values produce a more stable jet. It was also found that the empirical equation for penetration length is only valid for gas blowing with suciently high Froude numbers to produce a jetting behavior. It was found that the transition from pulsating to steady jetting in the IronArc system occurred around Froude numbers of 300 and higher values further increased the stability of the jet. For gas blowing below the transition region, the penetration length of the unstable and pulsating jet will be severely underpredicted by the empirical equation. This behavior must be considered when designing the gas blowing system for the IronArc process as the gas penetration length will signicantly influence the stirring in the reactor. Additionally, a pulsating and unstable jet produces large bubbles which risk coming in contact with the refractory walls which in previous studies has been shown to be very detrimental to the refractory lifetime. A decrease of the inlet diameter for the gas blowing increases the Froude number and the stability of the jet. By implementing the proposed refractory protection by freeze-lining and the small changes to the plasma generator inlet diameter the IronArc process can be developed into a promising industrial process capable of producing liquid pig iron in a more sustainable way. / Sammanfattning IronArc processen är en nytänkande metod för att producera flytande råjärn på ett mer hållbart sätt genom att använda elektricitet för uppvärmning och kolväten för reduktion. Denna avhandling ämnar att utvärdera möjliga metoder för att skydda infordingen i processen och undersöka gasblåsningen i processesen som görs med en plasma generator.   Ett av huvudstegen av IronArc processen är tillverkningen av en slagg med upp till 90 vikts % järnoxid samt 5 vikts % kiseldioxid och 5 vikts % kalciumoxid från gångarten. Interaktionen mellan en sådan slagg och olika infodringar baserade på MgO, Al2O3, Cr2O3, SiC, ASZ, och C undersöktes i högtemperaturexperiment vid 1700 K samt med termodynamiska beräknar i Thermo-calc och FactSage. Experimenten visade att alla de undersökta infodringsmaterialen bröts ned under de 3 timmar de var i kontakt med slaggen, men de två MgO-Al2O3 spinel baserade infodringarna visade högst motståndskraft mot slitaget. De termodynamiska beräkningarna överrensstämde bra med de experimentella resultaten för alla infodringsmaterial förutom den kromoxid baserade infodringen som bröts ned fullständigt trots att de termodynamiska beräkningarna påvisade viss stabilitet. Slutsatsen är att inget av de studerade infodringsmaterialen är bra anpassat för IronArc processen men att metoden som användes för de termodynamiska beräkningarna i Thermo-calc och FactSage kan användas för att ge en indikation om stabiliteten för olika infodringsmaterial i kontakt med slagg. Dock så kommer resultaten av de termodynamiska beräkningarna vara beroende av kvalitén av databasen som används för beräkningen.   Eftersom infodringsmaterialen inte kunde motstå slitaget från slaggen undersöktes en dynamisk infodring för slaggrännan i IronArc processen. Detta gjordes genom att simulera flödet och stelningen av slagg i flödesberäkningar i ANSYS Fluent i två olika typer av slaggrännor. Studien visade att enthalpy-porosity modellen för stelning samt RSM modellen för turbulens kunde förutspå stelningsförloppet i slaggrännan samt beskriva hur väl den dynamiska infodringen skyddar väggen och vilken kyleffekt som krävs för att bibehålla den. Denna modell validerades mot experimentella studier i CaCl2-H2O systemet med god överrensstämmelse. För optimalt skydd av väggarna i IronArc processen borde reaktorn och slaggrännan utformas så att flödet nära väggarna minimeras då ett turbulent flöde nära väggen är negativt för stabiliteten och tjockleken hos den dynamiska infodringen.   IronArc proceesen använder sig av en plasmagenerator för att förse processen med värme via elektricitet. Genom att blåsa gas och kolväten genom en ljusbåge värms gasblandningen och trycks in i reaktorn  vilket ger både värme och omrörning till processen. För att undersöka hur den varma gasen beter sig i reaktorn utvecklades en simuleringsmodell i OpenFOAM. Modellen utformades som både inkompressibel och kompressibel för blåsning av luft i vatten och jämfördes med experiment där gas blåstes i vatten. De båda modellerna överrensstämde bra med de experimentella resultaten och kunde därför användas för att studera gasflödet i IronArc processen. För simuleringen av IronArc processen valdes den kompressibla versionen av simuleringen då den tar hänsyn till de höga temperaturer och tryck som uppstår i reaktorn.   Simuleringarna visade att den inblåsta gasen kan ge en stabil gas-jet om Froude-talet för inblåset är tillräckligt högt. Om Froude-talet för gasblåsningen är för lågt så kommer gasen pulsera på ett instablit sätt och skapa stora bubblor som kommer i kontakt med infodringsmaterialet, vilket tidigare har påvisats orsaka ökat slitage på infodringsmaterialet. För IronArc processen krävdes ett Froude tal på ca 300 eller högre för att skapa en stabil jet av gas, där högre värden vidare ökar gas-jettens stabilitet. Studien visade också att den empiriska ekvationen som används för att beräkna penetrationslängden vid gasblåsning endast är korrekt om gasen är en stabil jet. Om ekvationen används för att beräkna penetrationslängden för gasblåsning med mindre än det krävda Froude talet kommer penetrationslängden kraftigt underskattas vilket kan medföra att fel beslut tas när en process utformas. Genom att minska diametern på dysan som används för gasblåsningen ökas Froude-talet och därmed stabiliteten av gasjetten, vilket gör den mer förutsägbar och bättre för processen.   För att vidare utveckla IronArc processen så bör den undersökta dynamiska infodringen samt de föreslagna modifieringarna till gasblåsningen användas. Då kan en lovande industriell process utformas som har möjlighet att producera flytande råjärn på ett mer hållbart sätt.    Keywords: IronArc, infodringsslitage, plasmagenerator, dynamisk infodring

This thesis deals with description of CRC codes, which is a type of polynomial error correction codes, and description of CAN and CAN FD protocols used in automobiles for data transmission between sensors. One of the security elements is usage of the CRC codes with the Hamming distance 6. Unfortunately, both protocols contain a design vulnerability which causes that some received messages with one wrong bit do not have to be detected by the protocol. The aim of the thesis was to describe this vulnerability and found out, if it was possible to eliminate it by using different CRC code. It managed to characterize all messages, which are not during this vulnerability detected by CRC code and based on that it was possible to prove, that the probability of error does not depend on a CRC code choice of a fixed length. 1

<p>Neutron Activation Analysis (NAA) is a non-invasive method for assessing the qualitative and quantitative elemental composition of a sample. One application of this technique is in-vivo quantification of specific elements in the human body. An important element in terms of human exposure assessment is Manganese (Mn). Mn is the fourth most usedindustrial metal and can be an  inhalation  exposure  hazard  specifically  for  welders.  Over  exposure  to  Mn  can  lead  to neurological degeneration issues similar to Parkinson’s disease. It has been found that bone is a good  biomarker  for  Mnas  Mn  is  deposited  in  the  bone  and  remains  for  long  periods  of  time,allowing  for  an  assay  to  reveal  long  term  exposure  information.  The  method  of  using  NAA  to quantify levels of Mn in-vivo using the bones in the human hand is being explored in this work.The  NAA  system  used,  involves  a  deuterium-deuterium  neutron  generator  and  an  N-type  High Purity Germanium Detector. It is critical to have the performance of the entire system characterized using phantoms and cadaver bones before the system can be used for in-vivo measurements. The goal of this work is to determine the neutron yield of the generator system, the neutron and photon dose  received  by  a  sample,  the  detection  limit  of  Mn  with  this  system,  and  to  evaluate  the  Mn detection capability of the systemusing cadaver bones from occupationally exposed Mn miners. The parameters were determined through a combination of simulation with Monte Carlo N-Particle Code  (MCNP),  experiments  using  Mn  doped  bone  phantoms  and  cadaver  bones,  and  various dosimetry  tools such  as  TLDs  and  EPDs.  The  neutron  yieldfor the  D-D  109M  generator  wasestimated to be2.24E+09+/-2.15E+07neutrons per secondfor this work. The Mn detection limit for the system was estimatedto be 0.442 ppm. The equivalent dose received by the sampleduring the standard 10-minute irradiation was estimated to be 8.45 +/-2.05rem. The results found for the human cadaver bones weremixed. It was found that the system was able to successfully detect Mn incadaver bones. Unexpectedly, however, three of the samples showed little to no Ca signal.In addition, significant amounts of soft tissue and bone marrow exist in the samples.Thereforethe Mn concentration in the bones was not able to be accurately estimated. A relative metric of Mn concentration  was  used  instead  and  showed  a  slight  positive  increase  from  the  unexposed  to exposed samples but was not statistically significant.</p>

The paper covers the use of a COMB generator to detect and diagnose RF problems related to cable and shielding problems in data acquisition systems in situ. The setup and method to conduct these tests is discussed in detail. Circuit design for a COMB generator is covered, as well as commercially available units. The use of a spectrum analyzer for the detector is covered and characteristic outputs are examined. Low cost alternatives to the spectrum analyzer are also examined. The COMB generator and the spectrum analyzer used for the test are portable devices and so, lend themselves to field use where access to alternating current sources is problematic.

Many real-time systems are developed and maintained through the use of commercial software products, such as Matlab and MatrixX, that automatically generate source code based on graphical control systems models. Testing these real-time models and the real-time software generated from them presents special problems during maintenance not faced with other forms of software. Very importantly, many of the models and software systems have to be tested through the use of simulations. Huge input and output data sets, the need for testing over a long duration of time (weeks or months), and computationally intensive requirements are just a few of the difficulties. For testing during maintenance in such situations, this paper draws upon field experience to present a set of test types and a strategy for selecting test types used to create series of input values to serve as test cases. Also this paper presents strategies for applying these test types, using the assistance of a free, widely available testing tool that automates test case generation, executes the simulations, and supports the analysis of the test results.

In einer Zeit von steigenden Studierendenzahlen und zunehmender Nachfrage nach individuellen Übungsmöglichkeiten, sehen sich Lehrende mit der Herausforderung konfrontiert, mit wenig Ressourcen möglichst viele Lernmöglichkeiten bereitzustellen. Computergestützte Übungen können hierfür eine ressourcenschonende Möglichkeit darstellen, und die direkte Interaktion zwischen Lehrenden und Lernenden um eine flexible und digitale Komponente ergänzen. Für eine Variation in den Single-Choice-Aufgaben kann ein Generator verwendet werden. Diese Arbeit untersucht den aktuellen Stand der Generierung von Multiple -Choice-Aufgaben und stellt einige Softwarelösungen vor. Im Anschluss wird die Implementierung eines angepassten Generators exemplarisch erläutert, anhand eines Prototyps in der Programmiersprache Python. Der Prototyp übernimmt eine Aufgabenschablone, die mehrere Antworten und Parameter enthalten kann. Daraus können viele unterschiedliche Aufgaben generiert werden.

There has been an increasing demand for describing, predicting, and drawing inferences for various environmental processes, such as air pollution and precipitation. Environmental statistics plays an important role in many related applications, such as weather-related risk assessment for urban design and crop growth. However, modeling the spatio-temporal dynamics of environmental data is challenging due to their inherent high variability and nonstationarity. This dissertation is composed of four signi cant contributions to the modeling, simulation, and prediction of spatiotemporal processes using statistical techniques and machine learning algorithms. This dissertation rstly focuses on the Gaussian process emulators of the numerical climate models over a large spatial region, where the spatial process exhibits nonstationarity. The proposed method allows for estimating a rich class of nonstationary Mat ern covariance functions with spatially varying parameters. The e cient estimation is achieved by local-polynomial tting of the covariance parameters. To extend the applicability of this method to large-scale computations, the proposed method is implemented by developing software with high-performance computing architectures for nonstationary Gaussian process estimation and simulation. The developed software outperforms existing ones in both computational time and accuracy by a large margin. The method and software are applied to the statistical emulation of high-resolution climate models. The second focus of this dissertation is the development of spatio-temporal stochastic weather generators for non-Gaussian and nonstationary processes. The proposed multi-site generator uses a left-censored non-Gaussian vector autoregression model, where the random error follows a skew-symmetric distribution. It not only drives the occurrence and intensity simultaneously but also possesses nice interpretations both physically and statistically. The generator is applied to 30-second precipitation data collected at the University of Lausanne. Finally, this dissertation investigates the spatial prediction with scalable deep learning algorithms to overcome the limitations of the classical Kriging predictor in geostatistics. A novel neural network structure is proposed for spatial prediction by adding an embedding layer of spatial coordinates with basis functions. The proposed method, called DeepKriging, has multiple advantages over Kriging and classical neural networks with spatial coordinates as features. The method is applied to the prediction of ne particulate matter (PM2:5) concentrations in the United States.

It becomes more common with hybrid and electric vehicles around the world and in Sweden. These cars are becoming more and more effective with new sources of regenerative power such as the engine break. This prolongs the cars range which is making electric vehicles more and more competitive. So what is the next step when it comes to reusage of already used electricity? Is there more electric energy that we can reuse to help power the car? Each car has four dampers that absorbs momentum and converts it to thermal energy so that they can dampen its spring. If instead this movement would be turned into elektricenergy it could be stored to the battery or used by the car directly, just like the electric energy generated from the engine brake. The cars would be even more effective and get an even longer range. “Den generativa dämparen” will take advantage of this energy so it won’t go to waste. “Den generative dämparen” will dampen the springs momentum with induction charging. If this implementation succeeds in hybrid and electric cars big savings can be made. It’s estimated that Sweden, with this damper, can save 170 GWh each year in 2030. / Det blir allt vanligare med hybrid och elbilar på vägarna runt om i världen, även i Sverige. Dessa bilar är effektiva och får längre räckvidd tack vare att de har en motorbroms som kan bromsa bilen och alstra ström till batteriet samtidigt. Finns det mer energi som kan alstras till batteriet från bilen? Varje bil har fyra stötdämpare som tar upp rörelseenergi och gör om detta till värmeenergi för att kunna dämpa varsin fjäder. Om denna energi istället kan omvandlas till elektriskenergi och sedan lagras i batteriet, precis som den elektriska energin motorbromsen alstrar, kan framtidens elbilar bli ännu mer effektiva och på så sätt få en ännu längre räckvidd. Det är denna energi som Den generativa dämparen ska ta tillvara på så att den inte går till spillo. Via induktion kommer Den generativa dämparen dämpa fjäderns pendelrörelse och gör om denna rörelse till elektrisk energi som sedan ladda fordonets batteri. Om detta implementeras i hybrid och elbilar kan stora besparingar göras. 2030 är det beräknat att Sverige själva kan spara in på ca 170 GWh per år med Den generativa Dämparen. Målet är att förlänga räckvidden för varje bil med upp till 4%.

Ces travaux de thèse préparés au laboratoire SATIE, s’inscrivent dans la promotion de l’énergie solaire photovoltaïque (PV). Dans ces travaux, nous nous intéressons particulièrement au dimensionnement et au contrôle-commande du système PV connecté au réseau dans un contexte d’utilisation au Tchad où l’on doit tenir compte des problématiques du coût, du rendement, de fiabilité du système et de la qualité de l’énergie. Le réseau considéré est un réseau basse tension BT (220 V) avec une fréquence égale à 50 Hz mais susceptible de varier, auquel on injecte une puissance de 5,2 kW. Une méthode de dimensionnement des éléments passifs du filtre, a été préposée en premier lieu. Dans le but de réduire le coût de fabrication et le volume du filtre passif, une technique de fragmentation en plusieurs petites inductances en série a été adoptée. Cette technique optimise le volume et le coût du système PV classique. Ensuite, nous avons proposé une nouvelle architecture du système PV connecté au réseau utilisant un onduleur multi-niveaux. L’adaptation de cet onduleur à structure innovante a permis de réduire le coût de fabrication du filtre passif d’environ 40 % par rapport au système classique optimisé, tout en augmentant le rendement. Enfin, une commande PQ découplée, utilisant une boucle à verrouillage de phase PLL pour synchronisation, a été conçue et appliquée aux deux systèmes PV. Elle est bien adaptée au système avec onduleur multi-niveaux. / This PhD work, prepared at SATIE laboratory, is part of the promotion of solar photovoltaic (PV) energy. In this work, we are particularly interested in design and control of the grid-connected PV system in a context of use in Chad where cost, reliability, efficiency, and energy quality issues of the system should be taken into account. The considered grid is a low voltage grid (220 V) with a frequency equal to fifty hertz (50 Hz) but likely to vary, in which a power of five point two ( 5.2 kW) is injected. A design method of the filter passive to reduce the filter elements is proposed firstly. In order to reduce manufacturing cost and volume of the passive filter, we apply a technique consisting of dividing each inductance value and making it in several small inductances in series. This technique optimizes the conventional PV system. Then, we proposed a new grid-connected PV system architecture using a multi-level inverter. The adaptation of this innovative structure has reduced the manufacturing cost of passive filter by nearly 40 % compared to the classical optimized system. Finally, a decoupled PQ control, using a phase locked loop for sysnchronization, has been designed and applied for both systems. It is well adapted to the system with multilevel inverter.

Following the trends to diminish the fossil fuel energy production new technologies known for their renewable sources have become a signficant option for helping combat climate change and handle the current oil prices. These new technologies base their power production on already established physical principles that convert mechanical power to electrical power. Generators are the fundamental piece of machinery for electricity production. Among the various types of generators that exist, permanent magnet synchronous generators (PMSGs) are commonly used for renewable electricity production. At present, the most used magnets for PMSGs are alloys of neodymium, iron, and boron which form a tetragonal crystalline structure known as Neodymium magnets (NdFeB). These types of magnets contain rare-earth materials, which makes them highly non-sustainable materials. Research to find new magnet compositions to substitute rare earth magnets or to reduce the weight and increase the efficiency of PMSGs is currently being studied. One option is to use Alnico magnets. This thesis project explores this option. With the help of a finite element analysis (FEA) software (COMSOL Multiphysics), three types of Alnico grades 5, 8 and 9 were implemented in the rotor of a spoke type generator to study the load limits of the rotor magnets, and together with this observe the demagnetization and impact that it has on the power production of the generator, in two different scenarios: 1) When the generator is connected to a nominal load under normal conditions and 2) when the generator is connected to a nominal load after a short circuit (SC). The simulations provided an insight into the load limitations that the generator has by each type of Alnico studied. Alnico 9 showed to be the best candidate magnet from the three magnets implemented with less demagnetization and higher electrical power output, followed by Alnico 8, which presented a good electrical power output at the nominal load scenario. Regardless of the higher demagnetization of Alnico 5, it proved to be a better candidate than Alnico 8 at the SC scenario.