This work explores the hydrothermal synthesis of LaFeO3 (LFO) nanorods with a high aspect ratio. Synthesis of rod shaped LFO is a stepping stone to the synthesis of strontium doped LFO (LSF) nanorods with high aspect ratio. These LSF rods can be used to structure and increase the area of dense LSF oxygen permeable membranes, which can be applied in the partial oxidation of methane for the production of synthesis gas. Obtaining a larger surface area can increase the oxygen transport through the membrane when the transport is limited by surface exchange reactions. Increasing the oxygen transport is the objective of the work. LFO was attempted synthesised by a direct and a two-step synthesis. Product morphology and phase composition have been explored by the use of SEM and XRD. In the direct synthesis the effect of potassium hydroxide concentration, molar ratio of iron to lanthanum and synthesis duration were varied to investigate the effect of these parameters. LFO was not produced in the direct synthesis; the products consisted of La(OH)3 and Fe2O3. Since LFO was not obtained, a calculation exploring the temperature where LFO become more stable than La(OH)3 and Fe2O3 was performed. The calculations show that the transition temperature where LFO is thermodynamically favoured is close to the operating synthesis temperature. The small driving force for formation of LFO at a temperature close to the transition temperature is the reason why LFO have not formed in the direct syntheses.The two-step method consists of hydrothermal synthesis of La(OH)3 nanorods, which were covered by iron nitrate solution and attempted converted into LFO by a topochemical reaction. In the study performed, the rod structure is lost when the product is calcined at 400 ºC. LFO is not observed formed at this temperature, and LFO nanorods were therefore not obtained in the two-step synthesis.

A study of the effect of various amounts of manganese in solid solution on the recovery and recrystallization behavior of an AlMn-alloy, for different annealing conditions after different degrees of deformation (cold rolling) has been carried out. The alloy studied was a 3xxx-type model alloy with 0.5 wt% Fe, 0.15 wt% Si and 1.0 wt% Mn. The studies were a contribution to the MOREAL-project, where the main objective is to quantify and characterize the softening behavior of recyclable aluminium alloys, with small amounts of manganese, iron and silicon, as a basis to validate and further develop the ALSOFT-model. 5 variants of the AlMn-alloy, with respect to strain and homogenization, were prepared and further investigated.Based on electrical conductivity measurements the different amounts of Mn in solid solution, after the different homogenization (hom.) treatments, were estimated to be approximately 0.85 wt% (as cast), 0.55 wt% (hom. nr. 2) and 0.49 wt% (hom. nr. 3). The reductions of Mn in solid solution by hom. nr. 2 and hom. nr. 3 resulted in less concurrent precipitation and consequently a larger effective driving force for recovery and recrystallization. The high amount of Mn in solid solution for the as cast variants resulted in much concurrent precipitation. Concurrent precipitation was found to delay and suppress the recovery and recrystallization processes. At high annealing temperatures, with no (or little) concurrent precipitation occurring, the recrystallised grain structures were found to be homogeneous, fine grained and consisting of equiaxed grains. In these cases the recrystallised textures were found to be approximately random after a strain of 0.7, while they showed cube textures of weak and medium strength after a strain of 3.0. At low annealing temperatures, with concurrent precipitation occurring, the recrystallised grain structures were found to be inhomogeneous and coarse grained, with grains elongated in the rolling direction. In these cases the recrystallised textures were found to consist of P-textures and ND-rotated cube textures of medium and high strength.A high degree of deformation was found to increase the rate and degree of the recovery and recrystallization processes during the isothermal annealing procedures, and to result in fine recrystallised grain structures, consistent with the increased effective driving force for recovery and recrystallization. A high degree of deformation was also found to increase the rate and magnitude of precipitation during the isothermal annealing procedures.Non-isothermal annealing experiments were carried out to investigate if they could result in significantly different grain structures and textures compared to the isothermal annealing experiments. No significantly different results were achieved, only results directly comparable to the results from the isothermal annealing experiments.

The economical feasibility of commercial, single-junction solar cells is limited by high costs and limited efficiencies. New solar cell concepts and materials are sought to decrease the production costs and increase the efficiency. Intermediate band solar cells (IBSCs) show a promising concept for increased efficiency up to 46.77% as they employ three band gaps that can be matched to the solar spectrum to minimize fundamental losses. Doping of copper gallium disulphide (CuGaS2) with transition metals like Fe and Ni to high concentrations can theoretically form an intermediate band (IB), which for Fe doping gives nearly optimal band gaps for IBSC applications. Copper gallium disulphide is synthesized in an environmentally friendly, inexpensive and simple hydrothermal synthesis which may contribute to decreased costs of solar cell production.The hydrothermal synthesis is developed to produce copper gallium disulphide from copper(I) chloride (CuCl), gallium(III) chloride (GaCl3) and excess thiourea (Tu) (SC(NH2)2) in deionized water. The influence of varying synthesis parameters on product purity, yield and morphology has been investigated through X-ray diffraction (XRD) and scanning electron microscopy (SEM). Energy dispersive X-ray spectroscopy (EDS) is used to investigate doping of copper gallium disulphide and identify particle morphologies formed by different phases. Formation of copper gallium disulphide proceeds through slow decomposition of Tu, driven by an equilibrium shift due to hydrogen disulphide (H2S) evolution and precipitation of sulphides like the intermediate phase digenite (Cu2-δS) into which Ga3+ ions are incorporated. An additional impurity of copper(II) sulphide (CuS) is commonly formed, and gallium(III) hydroxyoxide (GaO(OH)) forms at pH > 0.5. Products of high purity and yield are obtained at 250 °C with concentrations above 0.060 M copper(I) chloride and gallium(III) chloride with the complexing agent 1-pentanethiol, and 0.319 M without 1-pentanethiol. Introducing nickel(II) chloride (NiCl2) or iron(III) chloride (FeCl3) in the hydrothermal synthesis forms vaesite (NiS2) or iron pyrite (FeS2) impurities, respectively, and copper gallium disulphide is not doped to a desirable concentration for IB formation.Color variations in the products reveal off-stoichiometries which contribute to a wide range of particle and crystallite morphologies within each product. Yellow, stoichiometric copper gallium disulphide particles have been deposited on a Si(100) substrate and growth of a red, Ga-rich film was achieved with 1-pentanethiol. These products were subject to photoluminescence spectroscopy (PL) along with off-stoichiometric powders of doped and undoped products, but no luminescence was obtained, possibly due to high defect densities and non-radiative recombination. Dispersions of powders were also subject to absorption spectroscopy which indicate extensive scattering due to wide ranges of particle sizes. The morphology of powder products shows particularly large variations within and between the products. Nanoplate and pyramidal crystallites are produced through nucleation and growth to form network structures and polycrystalline spheres, rods and rose-like particles, which along with the crystallites have varying irregularities and sizes.

The aim of this thesis was to create an understanding between the electrochemical performance of a porous Ni-CGO anode used in SOFC, and its microstructural parameters when subjected to redox-cycling. The anode samples were produced consisting of two different layers, and subjected to different number of redox-cycling. Their electrical resistance was measured using electrochemical impedance spectroscopy (EIS), and their parameters were obtained by analyzing cross-section images from the samples obtained by the focused ion beam (FIB) or from simulated 3D-models. A large increase of Ohmic resistance was observed after 3-4 redox-cycles, while there was only a slight increase of the polarization resistance. The high increase of the Ohmic resistance is believed to be due to the observed Ni-coarsening and the net increase of the anode volume due to oxidation of Ni to NiO and subsequently reduced back to Ni. Both the Ni-coarsening and the net volume expansion decrease the Ni connectivity which increases the Ohmic resistance. More electrons are also forced to go through the lower-conducting CGO phase, which increases the Ohmic resistance, though preventing a higher increase since it is connecting the isolated Ni grains together. The low increase of polarization resistance is believed to be due to the large pore-CGO interfacial area, which compensates for the decrease in triple-phase boundaries (TPB). The resolution of synthetic microstructures is not enough to capture constrictivity and tortuosity effects realistically. The dimensions of most of the bottle necks are below 100 nm and hence the size classes must be in the range of 10 nm, which is similar as the resolution of FIB-tomography.

Sweden is undergoing energy transition to become a zero-carbon economy with electricity production aims at 100% from renewable resources by 2040. Sweden also has a national goal to have fossil-free vehicle fleet by 2030. The increasing share of intermittent renewable resources creates growth in mismatches between electricity supply and demand. Demand flexibility provides solution to imbalances in power system where the prosumers can regulate their energy consumption. Demand response (DR) mechanism could be beneficial to power gird stability. Electric heat pumps serve as a pool of flexible load meanwhile the thermal inertia of the residential buildings serves as thermal energy storage. In this thesis, a techno-economic analysis of demand flexibility from heat pumps for residential buildings located in central Örebro is carried out with assistance of building energy simulations. This thesis aims to improve the intelligence of this existing buildings by comprehending the size of thermal inertia availability according to different heat demand, building envelope materials, ventilation systems, weather conditions and user behaviors. Two multi-family residential buildings, Klockarängsvägen and Pärllöken, are selected for case study and compared in terms of thermal inertia and avoided peak power fees in avoided peak power fee from flexible heat pump loads. Both buildings use heat pumps for space heating and domestic hot water supply. Electricity billings are subscribed to power tariff scheme, which makes peak power shifting more profitable. On the coldest day scenario when the ambient temperature is -20°C, Pärllöken’s indoor temperature drops from 21°C to 19.1°C if heat pump is turned off for an hour. Klockarängsvägen’s indoor temperature drops from 21°C to 16.6°C if heat pump is turned off for an hour. At the lowest indoor temperature setpoint of 18°C, Pärllöken demonstrates a maximum power-shift capacity of 25 kW and heatshift capacity of 75 kWh on the coldest day. That of Klockarängsvägen is a maximum power-shift capacity of 20 kW and heat-shift capacity of 20 kWh. With larger building thermal inertia and more power-shift capacity, Pärllöken is undoubtedly the winner thanks to concrete wall materials, heavier building thermal mass, balanced ventilation, heat recovery system, and higher window class. In economic analysis, based on the proposed energy models, two control strategy options in Pärllöken are considered. Economic analysis focuses on winter season from October to March. Option 1 operates heat pump in variable capacity control mode at part load capacity. Option 2 operates in fixed capacity on/off -4- control. In winter season, Pärllöken saves 1 646 SEK in Option 1 and 2 273 SEK in Option 2. Klockarängsvägen only considers Option 1 for economic analysis, which results in 20 948 SEK avoided peak power fee. Option 2 for Klockarängsvägen exceeds indoor temperature setpoint very quickly mainly due to poorer building envelope insulation in which conserves lower thermal inertia. / Sverige genomgår en energitransformation för att bli en fossilfri ekonomi som siktar på att ha en elproduktion från 100% förnybara resurser år 2040. Sverige har också ett nationellt mål att ha en fossilfri fordonsflotta till 2030. Den ökande andelen av intermittenta förnybara resurser bidrar till ökning av obalans mellan produktion och efterfråga av elektricitet. Efterfrågeflexibilitet ger en lösning på problemet med obalanser i energisystemet där prosumenter kan reglera sin energiförbrukning. Efterfrågeflexibilitet kan vara fördelaktigt för kraft- och nätstabilitet. Elektriska värmepumpar kan agera som en stor flexibel last samtidigt som fastighetens termiska tröghet fungerar som värmeenergilagring. I denna avhandling utförs en teknisk-ekonomisk analys av efterfrågeflexibilitet från värmepumpar för två bostadshus beläget i centrala Örebro med hjälp av energisimuleringar av fastigheten. Genom denna avhandling syftar författaren på att höja intelligensen av de befintliga fastigheterna genom att undersöka storleken av den termiska trögheten som finns tillgänglig med avseende på olika värmescenario, byggnadsmaterial, ventilationssystem, väderförhållanden och användarbeteenden. Två flerfamiljshus, Klockarängsvägen och Pärllöken, väljs för jämförelse med avseende på den termisk tröghet som bidrar mest till efterfrågeflexibiliteten. De två utvalda fastigheterna använder värmepumpar för värme och varmvatten. Båda fastigheterna faktureras enligt effektabonnemang, vilket gör effektutjämning mer lönsamt. I det kallaste scenariot, när omgivningstemperaturen är -20°C, faller Pärllökens inomhustemperatur från 21°C till 19,1°C och Klockarängsvägens inomhustemperatur sjunker till 16,6°C om värmetillförseln stängs av i en timme. Under det lägsta börvärdet för inomhustemperatur på 18°C visar Pärllöken en maximal effektförskjutningskapacitet på 25 kW och för Klockarängsvägen-byggnader 20 kW. Med hänsyn till fastighetens termiska tröghet är Pärllöken utan tvekan vinnaren på grund av betong som väggsmaterial, högre termisk massa, balanserad ventilation, värmeåtervinningssystem och högre energiklass på fönsterglasen. Ovanstående skäl gör att Pärllökens termiska tidskonstant är minst tre gånger längre innan temperaturen når det lägsta börvärdet på 18°C, jämfört med Klockarängsvägen. Detta ger att Pärllöken har en högre förskjutningskapacitet av värme på 75 kWh jämfört med Klockarängsvägens maximala förskjutningskapacitet på 20 kWh. I en ekonomisk analys, baserat på författarens framtagna energimodeller, beaktas två styrstrategier i Pärllöken. Den ekonomiska analysen fokuserar på vintersäsongen från oktober till mars. Alternativ 1 driver värmepumpen med partiell kapacitet enligt reglerbar effekt. Alternativ 2 stänger av värmepumpen helt. Under vintersäsongen sparar Pärllöken 1 646 SEK med Alternativ 1 och 2 273 SEK med Alternativ 2. Klockarängsvägen använder sig endast av Alternativ 1 för en ekonomisk analys, vilket resulterar i en kostnadsbesparing på 20 948 SEK. En förstudie med värmepump i kombination med andra förnybara tekniker så som solceller på Klockarängsvägen genomförs för att undersöka potentialen av energibesparing. Kombinationen ger dock inte en positiv effekt på grund av den låga solinstrålningen under vintertid.