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This Thesis treats the growth and characterization of ternary transition metal nitride thin films. The aim is to probe deeper into the Ti-Al-N system and to explore the novel Sc-Al-N system. Thin films were epitaxially grown by reactive magnetron sputtering from elemental targets onto single-crystal substrates covered with a seed layer. Elastic recoil detection analysis and Rutherford backscattering spectroscopy were used for compositional analysis and depth profiling. Different x-ray diffraction techniques were employed, ex situ using Cu radiation and in situ during deposition using synchrotron radiation, to identify phases, to obtain information about texture, and to determine the thickness and roughness evolution of layers during and after growth. Transmission electron microscopy was used for overview and lattice imaging, and to obtain lattice structure information by electron diffraction. Film properties were determined using van der Pauw measurements of the electrical resistivity, and nanoindentation for the materials hardness and elastic modulus. The epitaxial Mn+1AXn phase Ti2AlN was synthesized by solid-state reaction during interdiffusion between sequentially deposited layers of (0001)-oriented AlN and Ti thin films. When annealing the sample, N and Al diffused into the Ti, forming Ti3AlN at 400 ºC and Ti2AlN at 500 ºC. The Ti2AlN formation temperature is 175 ºC lower than earlier reported results. Ti4AlN3 thin films were, however, not possible to synthesize when depositing films with a Ti:Al:N ratios of 4:1:3. Substrate temperatures at 600 ºC yielded an irregularly stacked Tin+1AlNn layered structure because of the low mobility of Al adatoms. An increased temperature led, however, to an Al deficiency due to an out diffusion of Al atoms, and formation of Ti2AlN phase and Ti1-xAlxN cubic solid solution. In the Sc-Al-N system the first ternary phase was discovered, namely the perovskite Sc3AlN, with a unit cell of 4.40 Å. Its existence was supported by ab initio calculations of the enthalpy showing that Sc3AlN is thermodynamically stable with respect to the binaries. Sc3AlN thin films were experimentally found to have a hardness of 14.2 GPa, an elastic modulus of 21 GPa, and a room temperature resistivity of 41.2 μΩcm.

Electronic-grade GaN (0001) epilayers have been grown directly on Al2O3 (0001) substrates by reactive DC-magnetron sputter epitaxy (MSE) from a liquid Ga sputtering target in an Ar/N2 atmosphere. The as-grown GaN epitaxial film exhibit low threading dislocation density on the order of ≤ 1010 cm-2 obtained by transmission electron microscopy and modified Williamson-Hall plot. X-ray rocking curve shows narrow fullwidth at half maximum (FWHM) of 1054 arcsec of the 0002 reflection. A sharp 4 K photoluminescence peak at 3.474 eV with a FWHM of 6.3 meV is attributed to intrinsic GaN band edge emission. The high structural and optical qualities indicate that MSEgrown GaN epilayers can be used for fabricating high-performance devices without the need of any buffer layer. GaN (0001) thin films were grown on Al2O3 substrates by reactive high power impulse magnetron sputtering of liquid Ga targets in a mixed N2/Ar discharge. A combination of x-ray diffraction, electron microscopy, atomic force microscopy, μ-Raman microscopy, photoluminescence, time of flight elastic recoil detection, and cathodoluminescence showed the formation of both relaxed and strained domains in the same films. . While the strained domains form due to ion bombardment during growth. The relaxed domains exhibit superior structural and optical properties comparative to the strained domains, including room temperature luminescence.

ScxAl1-xN and YxAl1-xN thin films were deposited in a ultra high vacuum system using reactive magnetron co-sputtering from elemental Al, Sc and Y targets in Ar/N2. Their mechanical, electrical, optical, and piezoelectrical properties were investigated with the help of transmission electron microscopy, xray diffraction, ellipsometry, I-V and C-V measurements, and two different techniques for piezoelectric characterization: piezoresponse force microscopy and double beam interferometry. Compared to AlN, improved electromechanical coupling and increase in piezoelectric response was found in ScxAl1-xN/TiN/Al2O3 structures with Sc content up to x=0.2. Microstructure of the films had a stronger influence on piezoelectric properties than the crystalline quality, which affected the leakage currents. YxAl1-xN thin films show a formation of solid solution up to x=0.22. Lattice constants obtained experimentally are in good agreement with theoretical predictions obtained through first principle (ab initio) calculations using density-functional formalism. The mixing enthalpy for wurtzite, cubic, and layered hexagonal phases of the YxAl1-xN system was also calculated.

No description available.

Active learning and computer simulations have been shown during the past two decades to be succesful factors for students’ conceptual gain within electromagnetism. Recent research over the last five years has helped solidify the understanding that even the application of simple simulations from the open access platform PhET can result in students understanding concepts more accurately. This study follows that line of research in order to enable a better learning environment in the physics classroom with the help of active learning and the application of computer simulations. The aim of this study is to investigate how one carefully planned laboratory session could have any effect on students’ conceptual gain within electromagnetism, partly for the greater purpose of understanding how single lessons can be used in an efficient way, but also to enrich the Swedish upper secondary physics classroom practice in applications of active learning and simulation inside the physics classroom. The results of the study suggests that the described method could be succesful if the scope of the session is focused on a narrow range of concepts, and that students feel highly motivated by working with computer simulations in particular. / Aktivt lärande och datorsimulering har under de senaste två decennierna visats vara framgångsfaktorer gällande elevers ökade konceptuella förståelse inom elektromagnetism. Forskning från de senaste fem åren har stärkt förståelsen att till och med tillämpning av simpla simuleringar från den öppna plattformen PhET kan resultera i att elever förstår sig på koncept mer ackurat. Denna studie följer den linjen inom forskning för att möjliggöra en bättre lärandemiljö i fysikklassrummet med hjälp av aktivt lärande och tillämpning av datorsimulering. Målet med denna studie är att undersöka huruvida ett noggrant planerat laborationstillfälle kan ha någon effekt på elevers konceptuella förståelse av elektromagnetism, delvis med det större syftet att förstå hur enstaka lektioner kan användas på ett effektivt sätt, men ocks˚a f¨or att berika det gymnasiala fysikklassrummets praktik i till¨ampning av aktivt l¨arande och simulering inuti klassrummet. Studiens resultat föreslår att den beskrivna metoden kan vara framgångsrik om laborationstillfället är fokuserat på ett smalt omfång av koncept, samt att elever känner sig mer motiverade av att arbeta med framför allt datorsimuleringar.

The way in which you decide the price for electricity is on it’s way to change in Sweden and to decrease the amount you pay for electricity you can use something called Peak Shaving. Peak Shaving is a method to reduce the overall power kWh peaks that an average power consumer uses monthly in order to reduce the price of the electricity bill. Furthermore, Peak shaving can be a method to resolve the lack of power in bigger cities. This is done by installing battery packs which store power when the power consumption is low. When power peaks occur, the power in the battery pack is used to help the grid and lower the peaks in the amount of power bought. With this method, you can reduce the power peaks you draw from the grid which leads to a lower monthly fee for the consumers.  In this report we investigated if Peak Shaving was profitable, more specifically for farmers and households with already installed solar panels. A model was designed to determine whether or not it is beneficial for the farmer to install battery packs for Peak Shaving depending on the power peaks they had per month. Data was received from two different farmers in Sweden containing energy bought, sold, produced(solar) and consumed. When comparing this to the price of power peaks per month as well as the price of the battery packs needed to contain the power to Peak Shave, the conclusion was made that Peak Shaving is not profitable with the current prices for batteries and their lifespan. However the price is on it’s way down. This could lead to Peak Shaving becoming a solution to save money for the customer but also to reduce the stress on the grid when Sweden transitions to fully renewable power.

Water toilets was introduced in Sweden in the early twentieth century. The waterenvironment was clearly affected as early as the 1960s. Swedish municipalities werecharged with the responsibility to deal with the rising environmental problem andthe given choice was sewage treatment plants. Municipalities need to provide drinkable water to their inhabitants and treat theirsewage water provided the region is densely populated enough that they wouldotherwise affect the local environment negatively. Los in Ljusdal municipally is oneof those places and the municipal’s sewage treatment plant has been determined byan external assessment to affect the local environment negatively (eutrophication). Multi criteria decision analysis has been chosen to compare different technologicalsolutions of which could solve the eutrophication issue in Los. The method issuitable to handle comparisons between different alternatives and every step of theprocess needs to be documented which in turn is very positive in the official sector,giving an additional layer of transparency. Decision makers have a great freedom ofdeciding criteria’s which will measure the performance of the different solutions.The different technical solutions in question are: renovating the sewage treatmentplant, replacing the old plant a new Swedish traditional sewage treatment plant orreplacing the old plant with a new SBR-treatment plant (sequenced batch reactor). This study was not able to find enough relevant material about the differenttechnological solutions to make qualified assessment due to the uniqueness of eachsolution. As an alternative result, each decision maker was asked to grade eachsolution based on their own experience and background. This doesn’t provide anunambiguous result based on the solutions given in this study but it does provide ahypothetical result. Multi criteria decision analysis indicated that the SBR-treatment plant had thehighest approval rating from the different decision makers. / I Sverige har vi haft WC i strax över hundra år. Redan 1960 fanns det tydligpåverkan på vattenmiljön från våra avlopp. Svenska kommuner fick ansvaret atthantera detta miljöbekymmer och detta genom kommunala avloppsreningsverk.Idag har kommunen ansvar för att tillgodose deras invånare med dricksvatten ochhantera deras avloppsvatten förutsatt att området är tillräckligt befolkat. Los är enby i Ljusdals kommun där invånarna har tillgång till detta. Det kommunalaavloppsreningsverket har i en extern utredning bedömts göra stor påverkan pånärliggande miljön i avseende på övergödning och har därför prioriterats attåtgärdas.Multikriterieanalys (MKA) valdes som metod för examensarbetet. Metoden är vällämpad för att jämföra flera alternativ på ett strukturerat vis och tillåter tydligdokumentering. Referensgruppen får välja vad som ska bedömas men även hurviktig varje bedömning är. Alternativen som ska jämföras är att renovera Losavloppsreningsverk, ersätta det med ett ordinarie avloppsreningsverk eller ersättadet med en SBR-anläggning (satsvis avloppsrening).Studien fann inte tillräckligt med material för att göra en god jämförelse mellan deolika alternativen. Istället för att basera MKA:n på material om de olika alternativenförlitade författaren sig på att varje enskild deltagare i referensgruppen hade relevanterfarenhet och bakgrund för att göra en kvalificerad gissning så ett hypotetisktresultat erhölls.SBR-anläggningen bedömdes vara det mest önskade alternativet baserat på resultatetfrån MKA:n. Alternativet hade högst prestanda i tre av fyra kategorier och teknikenanvänds redan av det kommunala VA-bolaget på andra platser inom kommunen.

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Syfte: Syftet med denna litteraturstudie var att undersöka huruvida synskärpa och kontrastkänslighet skiljer sig åt mellan en monofokal intraokulär lins (IOL) och en multifokal IOL. Mätningarna som denna litteraturstudie baseras på gjordes enbart på kataraktpatienter som var över 40 år gamla. Metod: Genom databasen Pubmed hittades olika studier som filtrerades där enbart studier som innehöll monofokala och multifokala IOL kopplat till kontrastkänslighet samt synskärpa inkluderades. Sex studier som alla var publicerade mellan 2013 och 2022 användes för att jämföra och analysera skillnad i synskärpa och kontrastkänslighet mellan en grupp med en monofokal IOL och grupp med en multifokal IOL.Resultat: Synskärpan vid olika avstånd varierade mellan monofokala och multifokala IOL. Multifokala IOL hade bäst okorrigerad synskärpa på nära håll. Ingen signifikant skillnad mellan IOL:erna visades på synskärpan på långt håll vare sig okorrigerad eller med korrigering för avstånd. Kontrastkänsligheten var bättre med de monofokala IOL:erna i alla studier förutom en. Slutsats: Multifokala IOL bör vara förstahandsvalet ifall man önskar en bättre okorrigerad synskärpa på nära håll. Det är visat genom studierna att den multifokala IOL:en inte försämrar synskärpan på långt håll, däremot försämras kontrastkänsligheten.