The field of crystallography has recently been expanded to include the science of quasicrystals, crystalline structures lacking unit cells and conventional periodicity. This resulted in a paradigm shift in the field, opening up for a whole new branch on the subject of structural chemistry. Despite this, not much is known about the abilities of quasicrystalline and approximant materials. Quasicrystalline approximants in the RE-Au-SM system have previously shown promising results regarding magnetic properties. To explore and discover properties like this is key to further improve the understanding of quasicrystalline materials.   The scope of the project was to explore the Gd-Au-Si system with compositions theoretically calculated to yield possible quasicrystals. In three batches with varying composition ratios, crystals were synthesised, using an arc-melting self-flux method. These were then analysed with powder X-ray diffraction, single crystal X-ray diffraction and electron dispersive spectroscopy (EDS) to characterise the synthesised compounds using diffraction data and composition data respectively. The resulting crystals were determined to be of a ternary composition close to what was theoretically calculated. The phase synthesised is yet to be found in any previous work or database, possibly marking it out as a new phase, albeit the structure not being quasicrystalline in nature. Thus, the exploratory study yielded a so for unobserved composition in the Gd-Au-Si system.

The aim of this project was to study and characterize the metabolitesof LGD-4033 in equine urine, with the final aim of using the results indoping controls in equestrian sports. Urine samples had been taken atdifferent points in time from three horses that had received thesubstance intravenously. The samples were both directly analysed usinga so called dilute-and-shoot approach and were also prepared with amixed mode anion exchange solid phase extraction. All analysis weredone with UHPLC-ESI-MS(/MS) in negative mode. A total of eightmetabolites were found, which were all combinations of phase Ihydroxylation and/or phase II glucuronidation. Of these a total of four(one that is both monohydroxylated and glucuronidated, one that isdihydroxylated, as well as two glucuronidated metabolites) would besuitable for doping control.

This thesis investigates how well the Alexandria (WBK) force-field can predict themelting point for multi-cation chloride salts with molecular dynamic (MD) simulationsin Gromacs 4.6.7. Researched is the eutectic ternary salt LiCl-NaCl-KCl(53.5-8.6-37.9 mol%) and its binary eutectic constituents(NaCl-LiCl: 22.5-77.5, KCl-NaCl: 50-50, LiCl-KCl: 58.5-41.5 mol%). The choosen salt mixtures are all promising candidates for use as electrolyte in liquidmetal batteries, a potential future power grid storage system. Simulation of the ternary salt's bulk at 298 K over 100 simulations with its ionsdifferently arranged within the crystal lattice for each simulation all resulted in stablecrystalline structures. This indicates that the WBK force-field properly andconsistently can produce stable crystalline structures not just for pure salts, but alsowithin multi-component ones. The melting point for the ternary and first binary combination was determined to550 K (12.9 % lower than experimental) and 950 K (12.6 % higher than experimental). No melting point could be determined for the last two binary combinations, as theymelted in their entire simulated temperature intervals. The ternary salt showcased acrystalline/amorphous mixture at solid phase temperatures when simulating with thesolid/liquid coexistence method. These simulation anomalies show that modeling ofmulti-cation chloride salts may not be as straight forward as it is with pure salts,despite using a force-field parameterized specifically for alkali halides.

The aim with this master thesis was to investigate the potential of using non-wood fibers to enhance the paper strength. Abaca, sisal and banana fibers were added to conventional bleached chemical softwood pulp. The effect of refining was investigated, both as co-refining and as separate refining. The fiber properties were determined with a Fiber Tester and the drainage resistance was determined with Schopper-Riegler. Density, tensile index, tear index and burst index were determined on paper sheets made in a Rapid-Köthen sheet former. The results showed that abaca had longer fiber length than softwood, while sisal had slightly shorter fiber length compared with softwood. Sheet density was lowered with addition of all three fiber types, while the drainage resistance was increased for the same. It was also observed that the tensile index increased with additions of abaca, while additions of sisal and banana fibers gave lower tensile indexes. The same trend was observed for the tear index and burst index. Refining gave higher values of the drainage resistance, density, tensile index and burst index. However, the tear index was affected differently depending on the fiber type and fiber blend. For sisal and banana fibers, the tear index was first increased at lower refining degrees and were thereafter decreased with further refining. When studying abaca and softwood, a declining trend was observed over the entire refining interval. The conclusion was that addition of abaca fibers increased all investigated strength properties. Sisal and banana fibers gave higher values of the tear strength, when exposed to mild refining.

Polycyclic Aromatic Hydrocarbons (PAH) are an organic compound group consisting of cyclic molecules of two or more condensed benzene rings. All PAH are toxic to living organisms and their toxicity increases with increasing molecular weight. PAH are classified as environmental toxins but are currently not prohibited from emitting. The absence of a ban is based on the fact that the emission sources are difficult to eliminate. The present emissions mainly stem from wood burning, where heating is the primary purpose. Historically, PAH have also been released from various industrial activities. PAH are formed by incomplete combustion of organic matter at temperatures around 600°C. Thousands of tonnes are released annually and deposite over time in soils. The larger compounds become relatively immobile due to their unpolar properties. The longer the deposition takes place, the harder the PAH bind to the organic matter in the soil and cause that the decontamination work becomes more difficult over time. The remediation work is costly and because emissions are ongoing, this means that land that has been cleaned up in the long term will be re-contaminated.   The original purpose of this study has been to investigate the PAH contamination rate in a specific soil area. Originally, the purpose was also to investigate which factors affect the development of the contamination rate and potentially make the calculation work more difficult. Hypothetically, an average contamination rate could be obtained by combining measured concentrations of the PAH-16 standard from previous measurements at the same location with a current concentration from the same area plotted against time. However, measured values ​​from repeated measurements are missing. Thus, the recontamination rate at present cannot be calculated, at least not by this method. As part of future studies, it would be advisable to start taking soil samples, analyzing the PAH-16 and storing the values ​​in an existing environmental database in order to be able to monitor concentrations in soils over time. Part of the problem with this is that it is difficult to take a test at exactly the same location twice and concentrations can differ markedly even in small areas. A method for the precise selection of sampling site would therefore be appropriate to develop. The study describes the problems that are found in connection with extraction and analysis of PAH. In the extraction and analysis work itself, the most critical elements have been shown to be to extract all PAH substance from the soil sample and subsequently to avoid laboratory-related losses and to detect all compounds in the analysis. The study also reports on a number of factors that make it difficult to calculate the recontamination rate in the absence of measurement series missing.

The Diesel Oxidation Catalyst (DOC) is subjected to harsh conditions, causing its performance to diminish over time as the result of different aging mechanisms, which either decreases or lowers the accessibility to the catalyst’s active sites. Previous work using chemisorption to quantify aging progression has resulted in a reproducibility of 17%. In this study it has been attempted to lower this, while also performing performance evaluations to see if correlations exist between dispersion and Light-Off Temperature (LOT). Two catalysts have been investigated, LLC (Low Loading Catalyst) and HLC (High Loading Catalyst). These were hydrothermally aged at 600 C, 700 C and 800 C. In addition to these, two HLC engine cell samples were also investigated. To ensure sample homogeneity, different sample preparation methods were investigated. Catalyst samples were crushed, or had their washcoat layer removed, or were milled and then sieved. A total of 5 runs were done using fresh catalysts of LLC and HLC to calculate the standard deviation. Evaluation of performance was done on all samples using Synthetic Catalyst Activity Testing (SCAT). It was deemed that the only viable sample preparation method was to mill and sieve as other methods would be hard to reproduce. The results showed that the reproducibility for LLC was %STD = 4% and for HLC %STD = 2%. For LLC, a correlation between catalytic activity and dispersion was found. The activity dropped with respect to the dispersion in a close to linear fashion without a large effect on BET surface area. For HLC the dispersion decreased largely upon hydrothermal aging, however no correlation was found with the activity; only when aged at 800 C a significant change in LOT was noted. The BET surface area measurements were inconsistent. Lower dispersion sometimes resulted in higher surface area. Engine cell samples exhibited notable decrease in dispersion, but not in surface area, and did not correlate to the hydrothermally aged catalysts, which might be due to other effects inhibiting CO chemisorption during measurements. / Dieseloxidationskatalysatorn (DOC) utsätts för tuffa förhållanden, vilket medför att dess prestanda minskar med tiden på grund av olika åldringsmekanismer, vilka antingen minskar dess aktiva säten eller minskar tillgängligheten till dessa. Tidigare studier då kemisorption använts för att kvantifiera vilken utsträckning katalysatorn har blivit deaktiverad har resulterat i en reproducerbarhet på 17%. Denna studie har syftat till att minska detta, men även till att utföra prestandamätningar för att se om det existerar korrelationer mellan dispersion och tändtemperatur (LOT). Två katalysatorer undersöktes, LLC (lågladdad katalysator) och HLC (högladdad katalysator), både som färska, men även som hydrotermiskt åldrade i 600 C, 700 C and 800 C. Dessutom undersöktes två motorcellsprover av HLC. För att säkerställa provhomogenitet undersöktes olika provprepareringsmetoder. Katalysatorprover krossades, eller fick washcoat avlägsnat eller maldes samt siktades. Totalt fem körningar gjordes på färska katalysatorer (LLC och HLC). Prestandamätningar gjordes på samtliga prov i Synthetic Catalyst Activity Testing (SCAT). Det bedömdes att den enda gångbara provprepareringsmetoden var att mala samt sikta katalysatorn då de andra metoderna skulle bli svåra att upprepa på ett reproducerbart sätt. Resultaten visade att reproducerbarheten för LLC var %STD = 4% och för HLC %STD = 2%. LLC visade på korrelation mellan katalytisk aktivitet och dispersion. Aktiviteten minskade linjärt utan större förluster i BETytarea. För HLC minskade dispersionen i hög grad med ökad åldringstemperatur, däremot kunde ingen korrelation med katalytisk aktivitet påvisas; enbart då katalysatorn åldrades vid 800 C ändrades LOT signifikant. Förändringarna i BET-ytarean var inte beroende av åldringstemperatur då lägre dispersion ibland resulterade i högre ytarea. För motorcellsproverna uppmättes en märkbart låg dispersion, medan ytarean var relativt oförändrad. Dessa resultat kunde inte korreleras till de hydrotermiskt åldrade proverna, vilket kan bero på att andra effekter inhiberat CO kemisorptionen.

The aim of this work was to manufacture and test non noble metal catalysts for CO oxidation and soot combustion. The feeding gases consist in the products of the combustion diesel in a Reformtech heater. These gases contain CO, CO2, H2O as well as small amounts of NOx and hydrocarbons. Two different catalysts were prepared for CO oxidation, based on cobalt oxide supported on ceria. 12Co/CeO2 with 12% weight of cobalt and 15CoOx/CeO2 with 15%. The first one was prepared by impregnation of cobalt nitrates in cerium oxide support; the second one was prepared by co-precipitation of cobalt and cerium nitrates. Another catalyst called 12Co4.5K/CeO2, with 12% cobalt and 4.5% potassium, was made for the simultaneous combustion of soot and oxidation of CO. The base also consisted in cobalt oxide supported on ceria, but with the addition of potassium which could stabilize the cobalt oxide particles. Both co-precipitation and impregnation methods gave the desired catalyst structure in the CO oxidation catalysts and both catalysts (12Co/CeO2 and 15CoOx/CeO2) showed activity. Nevertheless, the activity was lower than desired due to low surface area and mass transfer limitations. The catalysts also deactivated in less than three hours on stream, probably due to poisoning. The co-precipitation method for the 12Co4.5K/CeO2 catalyst gave the desired cobalt and cerium oxides, but no conclusion can be drawn regarding potassium since it was not shown in the XRD tests. The catalyst for both CO oxidation and soot combustion (12Co4.5K/CeO2) showed no activity for any of the reactions. Nevertheless, the tests performed to test the soot combustion ability were not conclusive and should be improved in future studies.

Biodiesel is an attractive alternative fuel for diesel engines.The feedstock for biodiesel production is usually vegetable oil, pure oil or waste cooking oil, or animal fats The most common way today to produce biodiesel is by transesterification of the oils with an alcohol in the presence of an alkaline catalyst. It is a low temperature and low-pressure reaction. It yields high conversion (96%-98%) with minimal side reactions and short reaction time. It is a direct conversion to biodiesel with no intermediate compounds. This work provides an overview concerning biodiesel production. Likewise, this work focuses on the commercial production of biodiesel. The Valdescorriel Biodiesel plant, located in Zamora (Spain), is taken like model of reference to study the profitability and economics of a biodiesel plant. The Valdescorriel Biodiesel plant has a nominal production capacity of 20000 biodiesel tons per year. The initial investment for the biodiesel plant construction is the 4.5 millions €. The benefits are 2 million €/year. The investment is possible to recuperate in less than 3 years. The biodiesel yield can up to 98% with catalyst in excess. The energy used for the biodiesel production is 30% less than the obtained energy from the produced biodiesel. Replacing petro diesel by the biodiesel produced in the plant, the CO2 reduction can reach the 48%. It means that 55 000 tons CO2 per year can be reduced The production of biodiesel from sunflower oil and ethanol using sodium hydroxide as catalyst was performed in the laboratory and the results are discussed. The results are analyzed using the statistic method of Total Quality. The effect of the ethanol/oil ratio and the amount of used catalyst on the yield as well on the properties of the produced biodiesel is studied. The measured properties of the biodiesel are density, viscosity and refraction. The ethanol/oil ratio influences on the biodiesel production. The yield of biodiesel increases with the ethanol/oil ratio.  Regarding the influence of the amount of catalyst on biodiesel production in the studied condition is not possible to achieve a definitive conclusion. But a tendency showing an increasing of the biodiesel yield with the amount of catalyst can be appreciated. The study of the evolution of the transesterification during time shows that a reaction time of one hour is sufficient enough in order to reach the highest yield of biodiesel.

The kraft process is a complex system with many variables, and though the process is fairly well understood, there is still much we do not know.      This thesis examines some aspects of the kraft process that could prove to be of interest for the pulp and paper industry, specifically, the impact of wood chip impregnation and of the chemical structure of xylan on spruce kraft pulp. The intent is to suggest modifications to the kraft process as it is used today.      The effect of wood chip impregnation varies with the prevalent conditions, and increases the effect of the subsequent kraft cook. Longer impregnation at a lower temperature was found to increase screened pulp yield, reduce shives content, make it possible to reach a certain kappa number at a lower H-factor, and make it possible to reach a certain kappa number at a lower total alkali consumption.      Xylan has previously been found to have a strength-enhancing effect on pulp, and the chemical structure of the xylan in question was found to be the main strength-enhancing factor. For spruce xylan, the structure that provides the largest increase in strength is not the same as the structure that increases the yield the most. Removing xylan was determined to have a negative impact on pulp strength.      Xylan extracted from agro waste can be used as an additive to increase pulp strength. This could be viable, especially when combined with the production of green plastics from hemicelluloses extracted from the agro waste.      A suggested configuration of a future pulp mill is presented, incorporating the following modifications to the now standard kraft cooking system: impregnation at a lower temperature for a longer time; extracting xylan-enriched black liquor at an early stage of the impregnation or cook, and adding this liquor at a late stage of the cook; terminating the cook at a higher kappa number; increasing oxygen delignification to compensate for the increased kappa number at the end of the cook, keeping the kappa number constant going into the bleaching plant; and adding agro-waste xylan during oxygen delignification. / <p>QC 20150525</p>

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