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SPME Method for Chemical Analysis of Heavy Organic Trace Compounds in Synthesis Gas / SPME metod för kemisk analys av tunga organiska spårämnen i syntesgasElemia Freire, Constancia Felise, Edin, Simon, Lee, Chang Ho January 2020 (has links)
There currently exists no commercialized method for rapid sampling and analysis of trace tar ingas streams. Solid phase microextraction (SPME) with a polydimethylsiloxane (PDMS) solidphase has been previously investigated as a possible candidate due to its solvent-free natureand reusability. This project set out to deliver a proof of concept study to test whether SPMEcan be sufficiently tuned to analyse trace tar content in syngas below the concentration of 0.1mg/Nm 3 . Due to complications that arose from the Covid-19 pandemic, it was unfeasible tocarry out the practical elements of the project. Instead a concept design for carrying out such astudy has been successfully developed. This design envisions a two-chamber setup able tosample syngas directly from a gasifier at 60 °C and 125 °C respectively and is illustrated in thetext. It utilizes commercially available solvent tubes to cross-check and verify the SPME results. / I nuläget finns det ingen kommersiell metod för att snabbt extrahera och analysera spår av tjärkomponenteri gasströmmar. Tidigare har solid phase microextraction (SPME) medpolydimetylsiloxan (PDMS) som fast fas undersökts som en möjlig kandidat då den ej kräverlösningsmedel och kan enkelt återanvändas. Detta projekt hade som mål att bevisa att SPMEkan anpassas tillräckligt känsligt för att analysera spår av tjära i syngas med en koncentration påmindre än 0,1 mg/Nm 3 . På grund av komplikationer som uppstod i samband med Covid-19pandemin var det inte möjligt att utföra den praktiska delen av projektet. Istället så har endesign tagits fram för ett koncept som beskriver hur man kan genomföra den praktiska delen.Designen beskriver en två-kammare lösning som kan användas för att ta prover från syngas somkommer direkt från en förgasare. Proverna tas vid temperaturer om 60 °C och 125 °C för attuppnå maximal känslighet. En uppsättning kommersiellt tillgängliga sorbentrör används för attkontrollera resultaten från SPME.
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Standardization and optimization of index for 28 day strength for cement made from standard clinker / Optimering och standardisering av 28-dygns hållfasthetsindex för cement tillverkat av standard klinkerHermansson, Anton January 2020 (has links)
This project regards the prediction of 28 day compressive strengths of cement. Using traditional multivariate analysis in combination with Artificial Neural Networks indexes have been developed which makes these predictions possible. Compressive strength is highly dependent on the cement hydration and clinker reactivity and literature on these topics have been studied followed by statistical analyses in Unscrambler X (Camo AS) and the Neural Networks model developed at Heidelberg Technology Center (HTC). After studying the theory behind compressive strength, some key parameters are identified including the Alite content, particle sizes as well as a variety of other parameters. Following this, a data set has been collected and formatted for the use in the project. Data on cement properties including compressive strength has been compiled by the quality engineer in Slite making the data collection simple. Having the data, the procedure includes a start with traditional multivariate analysis in Unscrambler to identify significant parameters in an effort of reducing the number of variables in the final model. In Unscrambler, Partial Least Squares regression has been used with uncertainty analysis as a selected option for parameter selection. Following the analysis in Unscrambler, the data set for each cement type is inserted into the neural networks models and the significant parameters are selected to act as input data, predicting either 1d or 28d strength. Before insertion into the Neural Networks model, the parameters are manually vetted with support of the literature and the accepted theories on cement hydration as correlations not necessarily mean that there is a causal link. Results are presented using the verification set of these indexes, indicating the prediction capacity of the indexes. Scenarios have also been used to study the underlying correlations between various properties and the compressive strengths. The results have shown good performance of the indexes created, and the procedure has proven to be fast and effective in creating these indexes. This opens up possibilities of using similar approaches to other areas of the plant in the future efforts to improve environmental and financial sustainability. Included in the final section of the report are also a few recommendations that would simplify the future work on this topic.
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Monitoring illicit drugs of abuse in wastewater from Umeå, Örebro, Örebro University and Örebro University HospitalSlettvoll, Tove January 2022 (has links)
Illicit drugs constitute a class of contaminants whose emissions to the environment has drawn attention due their potent pharmacological and biological activities. The monitoring of illicit drugs in wastewater and surface waters provides a powerful tool to investigate the presence, trends and to estimate the consumption of these psychoactive substances at the community level. The main aim of this thesis was to develop a solid-phase extraction (SPE) and ultra-high pressure liquid chromatography tandem mass spectrometry method for analysis (UHPLC-MS/MS) of illicit drugs in influent wastewater samples collected from four separate locations at different timepoints in Sweden and to assess differences in concentrations of illicit drugs among the four sites. The analysis of illicit drugs in wastewater is known to be challenging with regard to sample preparation, analyte recovery, ionization efficiency, as well as matrix effects. To overcome these challenges, an SPE UHPLC-MS/MS analytical method for the quantification of more than 30 illicit drugs was developed. Several parameters were optimized in order to improve the extraction, detection, and subsequent quantification of illicit drugs in wastewater samples. The results from the spike-tests show that SPE-UPLC-MS/MS method provided satisfactory recovery (69-133%), selectivity and linearity (R2= 0.997 ± 0.003). Three mobile phases were tested on the spike-tests whereof 5 mM ammonium formate gave the highest response for the majority of analytes and was thus selected. Finally, the method was applied to authentic influent wastewater samples collected at the municipal wastewater treatment plant from Umeå and Örebro as well as from wastewater samples collected from private wells from Örebro University and Örebro University Hospital. In total, 31 illicit drugs and their metabolites were targeted, among these 23 could be detected, out of which 12 could be accurately quantified and compared to other studies that monitored illicit drugs in major European cities. For the remaining 11 analytes, semi-quantitation was performed. Umeå had the most excessive use of amphetamine (386 ± 265 mg/1000p/day), cannabis (32 ± 16 mg/1000p/day) and benzodiazepines. Örebro on the other hand had higher abuse of cocaine (124 ± 60 mg/1000p/day), MDMA (25 ± 14 mg/1000p/day) and methamphetamine (2 ± 0.9 mg/1000p/day). Örebro University Hospital (USÖ) had the highest concentrations of opioids and ketamine, justified by their use as pain killers or anesthetics. Örebro University had detectable quantities of illicit drugs but in lower concentrations in comparison to the other sites. In conclusion, this thesis has successfully developed an analytical method for analysis of >30 illicit drugs in influent wastewater samples from four different sites in Sweden.
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Towards finding model pollutants for predicting CEC adsorption on biochars : The suitability of using dyes as proxies for CEC removal efficiency to enable wastewater reuseAveling, Alexandra January 2022 (has links)
This study evaluated the use of common dyes as model pollutants for adsorption on biochar. Pollutant removal efficiency of five dyes and three CECs on three different biochars (SWP-550, SWP-700, NDG-SW) was evaluated, using both UV-VIS spectrophotometry and LC-MS/MS, to examine similarities and differences in adsorption performance. In a parallel study, the impact of matrix effects on the adsorption of dyes and CECs was investigated by using both ultrapure water and effluent from wastewater treatment plant (WWTP). The analytes used in the study were malachite green (MG), methylene blue (MB), crystal violet, allura red, tartrazine, trimethoprim, diclofenac (DCF), and carbamazepine (CMP). MG, MB, CMP and DCF followed the same relative pattern in removal efficiency of different biochar products. This indicates that the dyes might be useful for comparing the efficiency of removal of CMP and DCF using biochar products.However, MG and MB did not prove useful in the quantification of CMP and DCF removal efficiency. NDG-SW had the highest pollutant removal efficiency. All biochar products were efficient in removing dyes at ng/mL concentrations. The matrix effect of the effluent water was considerable, with effects resulting in both the reduction and promotion of removal efficiency. Further studies, including PCA, would be useful to map out the correlations between specific dye and CEC adsorption to biochar.
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Towards the synthesis of phosphonic acid-based potential metallo-β-lactamase inhibitorsSundén, Erik January 2022 (has links)
No description available.
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Achieving dehalogenase activity with 2-phenylethyl bromide in a Y235C mutant of epoxide hydrolase StEH1Pålsson, Hannes January 2022 (has links)
No description available.
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Nonstoichiometric Multicomponent Nitride Thin FilmsShu, Rui January 2020 (has links)
High entropy ceramics have rapidly developed as a class of materials based on high entropy alloys; the latter being materials that contain five or more elements in near-equal proportions. Their unconventional compositions and chemical structures hold promise for achieving unprecedented combinations of mechanical, electrical and chemical properties. In this thesis, high entropy ceramic films, (TiNbZrTa)Nx were deposited using reactive magnetron sputtering with segmented targets. The stoichiometry x was tuned with two deposition parameters, i.e., substrate temperature and nitrogen flow ratio fN, their effect on microstructure and mechanical, electric, and electrochemical properties were investigated. Understoichiometric MeNx (Me = TiNbZrTa, 0.25 ≤ x ≤ 0.59) films were synthesized at a constant fN when substrate temperature was varied from room temperature (RT) to 700 °C. For low-temperature deposition, the coatings exhibited fcc solid-solution polycrystalline structures. A NaCl-type structure with (001) preferred orientation was observed in MeN0.46 coating deposited at 400 ºC, while an hcp structure was found for the coatings deposited above 500 ºC. The maximum hardness value of 26 GPa as well as the highest <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Ctiny%7BH/E_r%7D" /> and <img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Ctiny%7BH%5E3%7D%0A%0A" /><img src="http://www.diva-portal.org/cgi-bin/mimetex.cgi?%5Ctiny%7B/E_r%5E2%7D%20" /> values (0.12 and 0.34 GPa) were obtained for the MeN0.46 coating. These films exhibited low RT electrical resistivities. In 0.1 M H2SO4 aqueous solution, the most corrosion resistant film was MeN0.46 featured dense structure and low roughness. The MeNx films (x=0, 0.57 < x ≤ 0.83) were deposited with different fN. The maximum hardness was achieved at 22.1 GPa for MeN0.83 film. Their resistivities increased from 95 to 424 μΩcm with increasing nitrogen content. The corrosion resistance is related to the amount of nitrogen in the films. The corrosion current density was around 10-8 A/cm2, while the films with lower nitrogen contents (x < 0.60) exhibited a nearly stable current plateau up to 4.0 V, similar to the metallic films, while the films with a higher nitrogen content only featured a plateau up to 2.0 V, above which a higher nitrogen content resulted in higher currents. The reason was that the oxidation of these films at potentials above about 2.0 V vs. Ag/AgCl resulted in the formation of porous oxide layers as significant fraction of the generated N2 was lost to the electrolyte. Hence, these observed effects of deposition temperature and nitrogen content on the overall properties of nonstoichiometric MeNx films provide insights regarding protective multicomponent nitride films, e.g. as corrosion resistant coatings on metallic bipolar plates in fuel cells or batteries.
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Ortho-directed substitution of 2,1,3-benzothiadiazole derivativesEngman, Amanda January 2021 (has links)
No description available.
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Film morphology for organic solar cells : Effect of Solubility and Gravity ConditionsJalan, Ishita January 2021 (has links)
Organic photovoltaics is a promising environmentally friendly technology, due to their printability, light-weight nature and mechanical flexibility, and the possibility to use off-grid. Research and development in this field has resulted in power conversion efficiencies of over 15%. To further improve the efficiency, it is important to understand the connection between the morphology of the active layer and the performance of the device. This thesis focuses on understanding on a molecular level of the morphology formation in a thin coated film of a polymer bend, using two different approaches. One approach will focus on the thermodynamics of conjugated polymers in relation to the morphology, by using the Hansen solubility Parameters (HSP) and solution chemistry. The second approach focuses on understanding phase separation between the two polymers in the active layer. To be able to study phase separation, films were fabricated under microgravity conditions, as previous studies show that in these conditions phase separation mechanism is slowed down. Atomic force microscopy is used to characterize the resulting morphology of the thin films. Preliminary studies in this thesis showed that using HSP is a good tool, to understanding solvent-solute and solute-solute interactions in solution and to guide the final film morphology in relation to solubility. Furthermore, HSP is a good tool for the preliminary screening of alternative solvents and solvent blends for environmentally friendly processing solvents for upscaling. It was also found that dip coating of films under microgravity conditions provides a tool to study the early stages of the phase separation, as well as facilitate the study of the dependence of the morphology on the thicknesses of the coating. More work is needed to be able to separate the complex effect of hypergravity and to eliminate uncertainty concerning if the deposited wet film is completely dried under the microgravity phase.
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Determination of Diclofenac in Wastewater Using UHPLC-MSKritsotakis Wallin, Elektra January 2022 (has links)
No description available.
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