This work deals with fouling in the recovery boiler at Montes del Plata, Uruguay. Multivariate data analysis has been used to analyze the large amount of data that was available in order to investigate how different parameters affect the fouling problems. Principal Component Analysis (PCA) and Partial Least Square Projection (PLS) have in this work been used. PCA has been used to compare average values between time periods with high and low fouling problems while PLS has been used to study the correlation structures between the variables and consequently give an indication of which parameters that might be changed to improve the availability of the boiler. The results show that this recovery boiler tends to have problems with fouling that might depend on the distribution of air, the black liquor pressure or the dry solid content of the black liquor. The results also show that multivariate data analysis is a powerful tool for analyzing these types of fouling problems. / Detta arbete handlar om inkruster i sodapannan pa Montes del Plata, Uruguay. Multivariat dataanalys har anvands for att analysera den stora datamangd som fanns tillganglig for att undersoka hur olika parametrar paverkar inkrusterproblemen. Principal·· Component Analysis (PCA) och Partial Least Square Projection (PLS) har i detta jobb anvants. PCA har anvants for att jamfora medelvarden mellan tidsperioder med hoga och laga inkrusterproblem medan PLS har anvants for att studera korrelationen mellan variablema och darmed ge en indikation pa vilka parametrar som kan tankas att andras for att forbattra tillgangligheten pa sodapannan. Resultaten visar att sodapannan tenderar att ha problem med inkruster som kan hero pa fdrdelningen av luft, pa svartlutens tryck eller pa torrhalten i svartluten. Resultaten visar ocksa att multivariat dataanalys ar ett anvandbart verktyg for att analysera dessa typer av inkrusterproblem.

Cellulosananofibriller (CNFs) hör till naturens mest fundamentala byggstenar och förser naturliga material, såsom den yttre cellväggen i trä, med en otrolig styrka och styvhet. Genom att imitera träets arkitektur öppnas möjligheter upp för tillverkning av nya, biobaserade och lättviktiga strukturella material med mekaniska egenskaper som överskrider de för glasfiber, metaller och legeringar. Den ingenjörsmässiga utmaningen ligger i att framgångsrikt lyckas överföra de önskade mekaniska egenskaperna hos CNFs till filament som kan användas i material för dagligt bruk. Vid flödesfokuserad spinning av extraherade CNFs påverkar många parametrar den slutgiltiga funktionaliteten och kvaliteten hos de resulterande filamenten. För att optimera dessa processparametrar är mätning av de spunna filamentens dimensioner ett viktigt moment. Av särskilt intresse är filamentbredden, eftersom den är avgörande för de mekaniska egenskaperna. Karakterisering av filamentbredden är i dagsläget en mycket tidskrävande process där varje filament mäts manuellt i optiskt mikroskop. Det huvudsakliga målet med detta projekt är att effektivisera den nuvarande mätprocessen med avseende på både hastighet och noggrannhet med hjälp av laserspridning. I denna rapport visar vi på minst en halvering av nuvarande mättid vid användandet av en 3D-printad laseruppställning istället för ett optiskt mikroskop vid mätning av filamentbredd. Våra resultat indikerar att mätsäkerheten generellt är högre för lasermetoden jämfört med mikroskopin. Genomsnittliga standardavvikelser för mätvärden på tunnaste bredden från mikroskopi samt de två olika kurvanpassningsmetoderna vid lasermätning rapporteras vara 1.62, 0.85 (Curve fit) respektive 1.59 (Minima matching). Standardavvikelserna för tunnaste bredd korrelerar dock inte direkt mot metodernas noggrannhet eftersom de spunna filamenten uppvisar en stor variation i bredd längs med längden. En närmare jämförelse mellan mätvärden för matchade punkter på ideala och defekta filament demonstrerar att icke-uniforma och defekta filament påverkar mätnoggrannheten för laserspridningen negativt. Sammantaget stödjer våra resultat det faktum att ett tunnare filament resulterar i bättre upplösning och mindre mätfel vid mätning med laserspridning. Våra resultat visar på den stora potentialen för laserspridning som en mer effektiv mätmetod vid karakterisering av cellulosafilamentbredd. / Cellulose nanofibrils (CNFs) are one of nature’s most fundamental building blocks, providing incredible strength and stiffness to natural materials, such as the outer cell wall layer in wood. By mimicking the architecture of wood, possibilities opens up for the fabrication of new, biobased, light-weight structural materials with mechanical properties exceeding that of glassfibers, metals and alloys. However, the engineering challenge lies in successfully managing to translate the desirable mechanical properties of the CNFs into filaments that can be used in everyday life materials. Throughout the process of spinning the extracted CNFs into filaments, many factors and parameters affect the ultimate functionality and performance of the resulting filaments. Measuring the dimensions of the spun filaments is a crucial step in further optimizing process parameters. The width of the filament especially, impacts its mechanical performance. The characterization of the cellulose filament width is currently very time-consuming as each filament is manually measured using optical microscopy. The primary goal of this project is to make the current characterization process more effective, with respect to both accuracy and speed of measurement, by using laser scattering. In this report, we demonstrate a reduction by more than a half in measurement time using a 3D-printed laser scattering setup instead of an optical microscope when measuring filament width. Our results indicate that the certainty in measurement is generally higher for lase rscattering compared to optical microscopy. The mean standard deviations (SD) for the smallest widths estimated with optical microscopy and the two curve fitting methods used for the laser measurements are reported to be 1.62, 0.85 (Curve fit) and 1.59 (Minima matching) respectively. However, standard deviations for the thinnest width does not correlate directly to the accuracy of the methods since the spun filaments show a large variation in width along the length. A closer comparison between measurement values for matched points at ideal and non-uniform filaments demonstrate that the accuracy of the laser measurements are dependent on the uniformity of the filaments, with non-uniform filaments negatively impacting the accuracy. Our overall results supports the fact that a thinner filament gives a better resolution and smaller error when measuring with laser. Our results provide evidence for the great potential of laser scattering as a more efficient method for cellulose filament width determination.

A fairly new technology used to produce metallic components is powder metallurgy (PM). Among the advantages with this technique are decreased cost of production for complex-shaped parts, new alloys are made possible, reduced end processing, less material loss, and vibrational damping effects. The downside is the number of pores created which can alter the tribological properties of the material. The focus of this report is to investigate how lean PM steel behaves under tribological contacts.  Friction and wear will be investigated using a pin-on-disc setup to mimic the sliding part of a gear tooth mesh. Previous studies show that the amount of wear, and if the wear increases or decreases with increased density is dependent on the degree of porosity and the pore size. This means that the wear might be minimized by optimizing the number of pores in the material and their shape and size. The result of this study shows that the friction coefficient decreases with increasing density. The wear coefficient show signs of the same correlations but further tests are needed. The main wear comes from adhesive wear, with signs of abrasive wear. The amount of abrasive wear seems to increase with an increase in density, supporting previous studies claiming that pores can trap wear debris and decrease the number of abrasive particles in the contact.

Alzheimer's disease (AD) was first described more than 100 years ago and is today the most common cause of dementia. It is one of the progressive neurodegenerative diseases that affect 47 million people around the world between the ages of 60 and 90. One of the contributing factors to AD is extracellular amyloid – β (Aβ) plaques that form as a result of protein aggregation. These Aβ proteins are neurotoxic, leading to degeneration of brain neurons and loss of cognitive abilities. Because AD largely affects society, researchers are constantly working to find a cure, which currently does not exist. The purpose of this study was to use Drosophila melanogaster as a living organism model for the expression of two types of Aβ proteins related to AD, Arctic (Glu22Gly) and TandemAβ, and to study the survival of these AD flies when Bovine serum albumin (BSA) was added to the fly food. The hypothesis was that BSA would be effective in slowing down and/or preventing formation of toxic Aβ-aggregates. The focus was therefore to investigate whether the AD flies would live longer if they were allowed to eat Bovine serum albumin and whether the soluble/insoluble Aβ levels in these flies would decrease in comparison to the control AD flies that were not allowed to eat BSA. The effect of BSA on toxicity was evaluated using survival assay on male flies and the levels of soluble/insoluble Aβ were evaluated using Meso Scale Discovery (MSD) on female flies. In both experiments, the following six groups of flies were examined: myow1118 ± BSA; myoArctic ± BSA; myoTandemAβ ± BSA. Conclusions from the studies are that the survival of AD flies could not be extended by adding 0.61 mM BSA to the food, rather the data showed a weak but significant toxic effect in the presence of BSA in the AD flies. However, MSD data showed a reduction of insoluble Aβ aggregates and an equilibrium shift from insoluble Aβ aggregates to soluble Aβ aggregates in the presence of BSA in the AD flies. Equilibrium shifts were particularly detectable in Myo-TandemAβ flies fed with BSA. In Myo-Arctic flies fed with BSA only reduction of insoluble Aβ could be detected. This shows that it is not the amount of Aβ aggregates that is decisive for toxicity, but rather the presence of specific aggregates that have toxic properties. If BSA shows good results in further studies, it could be used in the future to improve AD symptoms in patients.