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Nuclear power technology is currently experiencing a revolutionary development process and its utilization is researched and debated throughout the world whereas sustainability is one of the most important topics in the material science arena. Some components in a nuclear power plant are subject to an irradiating environment which will cause significant damage to the material over time. Thus, it is of utmost importance that the affected materials are well designed for enduring such conditions because of the extensive lifetime of a nuclear power plant. The highly energetic particles that are inherent with nuclear reactions will generate point defects in the microstructure of the material which will alter its macroscopic behavior. Managing heat is crucial in a nuclear power plant and therefore this thesis is devoted to modeling the degradation effect on the lattice thermal conductivity as a result of the point defects, and to establish the intervening relation. This is achieved by ab initio simulations on supercells where the quantum-mechanical forces are calculated with density functional theory and with the generalized gradient approximation for the exchange-correlation term. The phonon Boltz- mann equation is solved by linearization and by using the relaxation-time ap- proximation which allows the lattice thermal conductivity to be calculated for the model. The phonon band modes and the phonon density of states is examined as well. To date there are no reports currently found in the literature where this topicis approached with similar methods. / Kärnkraftsteknologin genomgår just nu en revolutionerande utvecklingspro- cess och dess användning debatteras över hela världen där hållbarhet är en av de viktigaste ståndpunkterna i materialvetenskapsområdet. Vissa komponenter i ett kärnkraftverk blir utsatta för en bestrålande miljö vilket orsakat stor skada på materialet över tid. Det är därför av högsta vikt att dessa material är desig- nade för att motstå sådana miljöer på grund av kärnkraftverkens långa livstid. De högenergetiska partiklarna som är förekommande vid kärnreaktioner gene- rerar punktdefekter i materialets mikrostruktur vilka ändrar de makroskopiska egenskaperna hos materialet. Värmehantering är kritiskt i ett kärnkraftverk och därför är detta arbete de- dikerat till att modellera effekten av försämring av värmeledningsförmågan i kristallgittret, som resultat av punktdefekterna, och att definiera sambandet. Detta uträttas genom ab initio simuleringar av superceller där de kvantmekaniska krafterna beräknas med täthetsfunktionalsteori med en generaliserad approximation av täthetsgradienten för den tillhörande utbytes- och korrela- tionstermen. Boltzmann ekvationen löses med hjälp av linjärisering och med en approximation av relaxationstiden vilket används för att beräkna värmeledningen i gittret för modellen. Fononernas band-moder och tillståndstäthet undersöks därtill. För närvarande finns det inga rapporter bland litteraturen där detta ämne behandlas med samma metoder.

The aim of this report is to study a proposed air pollution control (APC) system designed to treat flue gases produced during the combustion of waste derived syngas. In order to achieve this objective, a literature study was done to gain insight into the pollution formation during gasification and combustion of syngas, and a model of the APC system was built using the Aspen Plus software. This model was used in four different case studies aimed at optimizing the water and chemical requirements throughout the system. Several different types of wastes were considered; municipal solid waste (MSW) representing that which is normally generated in developed countries, MSW representing that which is normally generated in developing countries, a waste composition representing that of the plastic fraction of MSW, and a waste composition representing that of the biomass fraction of MSW.   Based on the results of the literature study, a few conclusions could be drawn. Sulfur compounds could be expected to be found in the form of H2S in the syngas and SO2 in the flue gases. Chlorine compounds could be expected to be found in the form of HCl and the nitrogen compounds in the form of NH3, HCN and N2 after gasification and NO after combustion. The amount of research done in the area of MSW gasification, and combustion of MSW based syngas, is, however, small, and more research is needed.   Based on the results of the case studies, the amount of NaOH varied greatly depending on flue gas composition and negligibly depending on recirculation setup. The total amount of water required varied notably between the different cases studied and no case stood out clearly as the optimal case for all four waste compositions. The case studies seemed to indicate a trend towards an increased total water requirement with an increase in the amount recirculation. The four best cases where cases 2,3,4 and 10, out of which case three has been recommended as a good initial estimate from which to depart when finding the optimal setup for a specific system under study. In case 3, 40 wt% of the fresh water from the first splitter was sent to the direct contact scrubber, 50 wt% of the remaining fresh water was sent to the absorption tower, 40 wt% of the liquid leaving the absorption tower was recycled back to the direct contact scrubber, and 40 wt% of the remaining water leaving the absorption tower was recycled back to the absorption tower.

The cost of emission rights has increased significantly in recent years and is now almost at the 100-euro mark. By performing a cost analysis of the full Carbon Capture Storage (CCS) cycle and comparing it to the cost of emission rights, is it possible that CCS-technology is economically viable to implement today? This study was conducted in order to evaluate a possible CCS scenario for the Swedish steel industry. Cost comparisons of alternatives in the CCS process chain were made with different methods such as mapping points for capturing CO2 and drawing iso-cost curves for the transportation phase. The transportation itself could be done with trucks, ships or a pipeline system to the location for storing the CO2. Results indicate that the most feasible implementation of a CCS solution for the Swedish steel industry is a hybrid scenario where a pipeline from Oxelösund to Borlänge is used for transport in conjunction with trucks and ships. All the captured CO2 would be transported and converge at Oxelösund before being transported and injected into the storage site outside of Gotland. / Priset för utsläppsrätter har ökat avsevärt under de senaste åren och idag är en värd nästan 100 euro. Genom att utföra en kostnadsanalys av hela Carbon Capture Storage (CCS) och jämföra den med kostnaden för en utsläppsrätt, är det möjligt att CCS-teknologi är ekonomiskt gångbart att implementera idag? Det här arbetet gjordes för att utreda ett gångbart CCS scenario för den svenska stålindustrin. Kostnadsjämförelser för olika alternativ i CCS processkedjan gjordes med olika metoder, såsom kartläggning av utsläppspunkter för CO2 och skissering av iso-kostnadskurvor för transportfasen. Transporten i sig utgjordes av lastbilar, fartyg eller rörledningssystem till slutförvaringen av CO2. Resultaten indikerade att den mest genomförbara implementeringen av en CCS lösning för den svenska stålindustrin är ett hybridscenario där en rörledning dras från Oxelösund till Borlänge och används för transporten av CO2 tillsammans med lastbilar och fartyg. All den transporterade koldioxiden skulle konvergera vid Oxelösund, innan den transporteras och injiceras i slutförvaringen utanför Gotland.

Replacing fossil carbon materials with renewable biocarbon is one way to reduce the net carbon dioxide emissions of the iron and steelmaking industry. Carburization is an important application in the electric arc furnace (EAF), and is mostly achieved by adding fossil-based carbon materials into the melt today. Bio carbon have lower densities and carbon concentrations. It therefore requires densification and blending with higher carbon-containing materials. This project studied the factors influencing the mechanical strength of renewable iron-carbon briquettes designed for carburization. The briquettes were made of coal (a fossil carbon) of higher carbon concentration, hydrochar (a biocarbon), and iron powder. The variable parameters for briquetting include the particle size of coal (<45 μm, 45-63 μm, 63-100 μm, 100-200 μm) and the percentage of hydrochar in the briquettes (4,8,16 wt%), while the particle size of hydrochar, percentage of iron powder in the briquette, and briquetting pressure (50 MPa) were kept constant. The results indicated that all briquettes were destroyed by the fifth drop, and the rate of destruction of all briquettes were similar. The reason could be that the pressure used was not high enough to activate the binding properties of the hydrochar. Another reason could also be because of the hydrochar particles being larger than the coal particles. A variation of drop test procedure was proposed which might give more reliable and reproducible results. / Ett sätt att minska koldioxidutsläppet från stålindustrin är genom att ersätta dem fossila kolkällor som används mot hållbara biobaserade källor. Uppkolning är ett viktigt fenomen inom ljusbågsungar och i dagens industri så utnyttjas fossila kol för att uppnå detta. Biokol har lägre densitet och kolkoncentration än fossila kol. Vilket gör att man måste öka dessa egenskaper genom att blanda biokolet med material som har högre kolkoncentration. Denna rapport undersöker därför faktorer som påverkar mekaniska egenskaper av kol-järn briketter för uppkolning. Briketter som undersöktes var gjorda av en blandning av fossilt-kol, hydrochar (en typ av biokol) och järnpulver. Det fossila kolet används för dess höga kolkoncentration. Rörliga parametrarna var partikelstorlek (<45 μm, 45-63 μm, 63-100 μm, 100-200 μm) och hydrochar viktprocent (4,8,16 wt%), medans briketteringstrycket (50 MPa) samt mängden järnpulver hölls konstant. Enligt resultaten så var samtliga briketter vid det femte droppet, samt att viktförlusten för varje dropp var liknande för alla skapade briketter. Detta skulle kunna bero på att trycket som användes ej var tillräckligt för att aktivera hydrochar:ets bindande egenskaper. Det skulle även kunna bero på att hydrochar:et hade större partiklar än kolet. Diverse förbättringar föreslås när det gäller testningen.

The steel industry emits large amounts of carbon dioxide, the main emissions are produced inthe process of heating up steel in industrial furnaces of electric arc furnaces (EAF). The purposeof this project was to propose and evaluate a process of reforming biogas to hydrogen to use asfuel for industrial furnaces and result in carbon neutral or carbon negative emissions. This hasbeen done through a literature study reviewing current methods of reforming biogas to hydrogengas, computer simulations in a program called Aspen Plus, thermodynamic calculations and acomparison with the combustion of pure methane. The study resulted in a process theoreticallypossible which would produce negative carbon emissions as a result of carbon capture andstorage techniques. The proposed process is not as efficient as the process of burning puremethane, however, because it can offer carbon negative emissions it is still a more beneficialoption environmentally. / Stålindustrin släpper ut stora mängder koldioxid. Industrins huvudsakliga utsläpp produceras iprocessen där stål värms upp i industriella ugnar, exempelvis ljusbågsugnar (EAF). Syftet meddetta projekt var att utvärdera och föreslå en process för att reformera biogas till vätgas. Dettaför att kunna användas som bränsle för industriella ugnar och resultera i koldioxidneutrala ellernegativa koldioxidutsläpp. Projektet har utförts genom en litteraturstudie som granskatnuvarande metoder för reformering av biogas till vätgas, datorsimuleringar i Aspen Plus därtermodynamiska beräkningar och en jämförelse med förbränning av ren metan utfördes. Studienresulterade i en process som är teoretiskt möjlig, och som skulle ge negativa koldioxidutsläpp tillföljd av tekniker för avskiljning och lagring av koldioxid. Däremot är den föreslagna processen ärinte lika effektiv som processen att bränna ren metan, men eftersom det kan ge negativakoldioxid utsläpp är det fortfarande ett fördelaktigt alternativ med hänsyn till miljöaspekter.

This project investigates the σ-phase formation energy at 1000 Kelvin using Exact Muffin TIn Orbital (EMTO) method and considers the disordered local moment approach to handle the paramagnetism in a self-consistent manner. The sigma phase is detrimental and causes embrittlement when it occurs primarily in stainless steel and superalloys with Iron (Fe) and Chromium (Cr), which is why it is necessary to understand it better and therefore avoid it. The lattice of σ contains 5 nonequivalent sites which will be modeled through a 5 sub lattice model for the intermetallic phase. The method is based on Density Functional Theory and generates the formation energy for different configurations with different compositions of Iron, Chromium and Nickel(Ni) in the 5 sub lattice model with different Wigner Seitz radii. That made it possible to calculate properties as energy related to other phases and bulk modulus which can be used to calculate other properties. Comparing the results to values of other metals and experimental values of the sigma phase, the results were reasonable but need to consider what simplifications were made. With continued efforts with the results it is a possibility to use it for Calphad modeling which was not possible due to time. The results did not achieve the goal which was to use it for Calphad modeling, however showed that the results were reasonable and that EMTO can be used in the future for simulations of the sigma phase. Other things such as site occupancy and the vibrational contribution to the free energy is reserved for future work. / Detta projekt undersöker σ-fas bildnings energin vid 1000 Kelvin med hjälp av Exact Muffin TIn Orbital (EMTO)-metoden och överväger det oordnade lokala momentet för att hantera paramagnetismen på ett själv konsekvent sätt. Sigma fasen är förödande och orsakar sprödhet, den förekommer främst i rostfritt stål och superlegeringar med Järn(Fe) och Krom(Cr), genom att förstå fasen bättre för att kunna undvika den. Gittret för σ innehåller 5 icke-ekvivalenta platser som kommer att modelleras genom en 5 sub-gitter modell för den intermetalliska fasen. Metoden är baserad på   täthet funktionell teori och genererar bindningsenergin för olika konfigurationer av Järn, krom och Nickel i 5 sub-gitter modellen med olika wigner seitz-radier. Det möjliggjorde att beräkna egenskaper som energi relaterad till andra faser och bulkmodul som kan användas för att beräkna andra egenskaper. Jämfört med värden för andra metaller och experimentella värden för sigma fasen var resultaten rimliga men måste överväga vilka förenklingar som gjordes. Med fortsatt arbete med resultaten är det möjligt att använda det för Calphad modellering vilket inte var möjligt på grund av tid. Resultaten uppnådde inte målet som var att använda det för Calphad modellering, men visade att resultaten var rimliga och att EMTO kan användas i framtida beräkningar för sigma fasen. Andra saker som förekomst av elementet på de olika platserna i gittret och vibrations bidraget till energin reserveras för framtida arbete.

Metal-organic frameworks (MOFs) are a class of hybrid organic/inorganic materials with permanent porous structure. Whilst there are virtually endless possible selection of metal ions and organic ligands to build up a MOF structure, intrinsically conductive MOFs are rare, relatively new, and our knowledge on their conductivity and charge transport mechanisms is limited. Crystalline porous structure with intrinsic electrical conductivity gives new dimension for applications of MOFs. Therefore, it is very important to improve our understanding of conductivity principles, charge transport mechanisms and measurement methods to be able to compare different MOFs in electrical properties.We measured conductivity of a completely new bismuth-based MOF synthesized at Uppsala university (UU-200) to investigate the possibility of utilizing this material for chemiresisitive applications since it has selective adsorption for CO2 and SF6. We used Cu3(HHTP)2 as our reference MOF to establish the conductivity measurement method and compare our results with previous studies.Four-point probe conductivity measurements on pressed pellets of Cu3(HHTP)2 MOF showed that our method is chosen and performed correctly. The measured conductivity values for Cu3(HHTP)2 increased from 0.0022 S cm-1 to 0.0187 S cm-1 with decrease in porosity of the synthesized MOFs. We used identical parameters and condition for conductivity measurements of UU-200 samples which resulted in conductivity values of 2.37 x 10-6 S cm-1 and 5.78 x 10-6 S cm-1. These results show that firstly, considering UU-200 for chemiresistive applications cannot be ruled out; and secondly, the large difference in conductivity values of two similar materials can be related to anisotropic characteristics of UU-200’s 3D structure.

This degree project, conducted at Prevas AB, investigates if there is potential reduced production costs due to a change of material of the casing of a Digital Breathalyzer, with retained product characteristics. Considering the using of the product, 5 materials are presented and compared with respect to mechanical and thermal properties. A material analysis containing a merit value table is made and a new casing made of ABS/PC biocompatible plastic is chosen and redesigned with lowered production costs as a result. Return on Investment (ROI) in years and number of produced pieces is calculated with respect to necessary investments and potential reduced costs. With a production rate of 1000 and 4000 pieces per year the ROI is 11,2 and 2,76 years respectively, and ROI regarding production volume is 11 204 and 11 049 pieces respectively. / Detta examensarbete, utfört på Prevas AB, undersöker om det går att minska produktionskostnaden genom att byta material av höljet på en digital alkoholmätare, med bibehållna produktegenskaper. Med produktens användande i åtanke presenteras och jämförs 5 alternativa material med avseende på mekaniska och termiska egenskaper. En materialanalys innehållande en meritvärdesanalys genomförs och ett nytt hölje av materialet ABS/PC biokompatibel väljs och designas om med en lägre produktionskostnad som resultat. Avkastningen mätt i år och antal producerade produkter kalkyleras med avseende på nödvändiga investeringar för projektet och potentiella minskade kostnader. Med en produktionsvolym på 1000 och 4000 per år blir avkastningen 11,2 och 2,76 år.Avkastningen i antal producerade produkter är 11 204 och 11 049.

A project to construct a high-speed road deflection tester was initiated in the 1991. A mid-sized truck was used as a carrier for the first prototype. The results were promising and it was decided to build a full-size truck system. The new vehicle, based on a Scania R143 ML, was completed in 1997. The Road Deflection Tester (RDT) is equipped with two arrays of twenty noncontact laser sensors that collects transversal surface profiles at normal traffic speeds. One profile, placed between the wheel axles, constitutes an unloaded case. The other profile, just behind the rear axle of the vehicle, constitutes the loaded case. By subtracting the front cross profile from the corresponding rear one, the "deflection profile" is assessed. The deflection is assumed to vary with the stiffness of the road. In order to produce a large load on the rear wheels the engine was mounted in the back of the vehicle, slightly behind the rear axle. In testing mode the rear axle force is approximately 112 kN, and the front axle force is about 30 kN. An incremental wheel pulse transducer, two force transducers and two accelerometers, an optical speedometer and a gyroscope are also mounted on the RDT. The first test programme was carried out in 1998. Due to the careful choice of test sections, data from these sections still produce the best results. A smaller test programme was carried out in 2001, and a larger one in 2002 when the RDT was taken to England and France for demonstration. Promising results, both on an aggregated scale and for individual test sections, have been obtained. The RDT compares favourably with the Falling Weight Deflectometer. Short histories of road construction and road research give some historical and cultural background to the more recent developments. A more comprehensive history of rolling deflectographs presents all devices found in the literature from the start in the mid-fifties when the California Traveling Deflectograph and Lacroix Deflectograph were constructed, to the latest laser based High-Speed Deflectograph. Many references are given for further reading. The data acquisition hardware on the RDT system consist of sensors, signal converters, signal processing cards, an industrial computer for data communication, and an ordinary PC for operating the equipment and data storage. The software used to evaluate the data is written entirely in Matlab. Many levels of pre-processing make evaluation relatively fast, and the modularised design makes it easy to implement new evaluation algorithms in a clean and efficient way. A literature survey on the deformations of solids under static and moving load is presented in Appendix A. The static case started with Boussinesq in 1885, was much developed in the sixties, but since the eighties only a very limited amount of new results have been published. The moving load case, on the other hand, is still an field of active research and development. / QC 20101108