Faculty of Science
Recent Submissions
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(2024)This thesis investigates the integration of open-source retrieval-augmented generation (RAG) with large language models (LLMs) on the Databricks platform. The aim is to provide advanced insights in the fields of business, market, and responsibility intelligence. The research explores combining RAG and LLMs to improve business intelligence by leveraging internal and external data sources. The integrated system uses unstructured data such as market reports and customer feedback to offer deeper insights into market trends, consumer behavior, and corporate responsibilities and aid in company employees everyday work. Methodologically, the thesis focuses on system architecture, data source selection, and technical implementation within the Databricks environment. Use-cases such as expert assistance, market analysis, and customer feedback answering, demonstrating the practical benefits of these models for business operations are outlined. The research discusses technical challenges, evaluation strategies, and ethical considerations. The results emphasize how this integration aim to enhance data analysis and decision-making and to improve the ability to generate insights. The system’s applications at Metsä Tissue highlight the strategic and operational advantages of implementing RAG with LLMs. The thesis provides a roadmap for using advanced AI techniques to improve business intelligence in various domains while considering ethical implications and future research pathways. In the development of this master’s thesis, the advanced capabilities of ChatGPT-4 and ChatGPT 4o have been utilized to assist in various stages of the writing process. These language models aided in planning the structure contents of the thesis, rephrasing text to enhance clarity and coherence, and checking the grammar to ensure the quality of academic writing.
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(2024)As the demand for sustainable energy sources is continuously growing, green hydrogen produced by water splitting is considered one of the key energy sources of the future. In this thesis, catalysts with low noble metal content for the acidic Oxygen Evolution Reaction (OER) have been synthesized, and their electrochemical performance have been investigated. OER is one of the half-cell reactions in water-splitting, the other being the Hydrogen Evolution Reaction (HER). The OER is the more energy demanding and harder to optimize half-cell reaction, because of its more complex kinetics. The currently well-studied catalysts for the acidic OER, namely IrO2 and RuO2, are expensive, scarce and not feasible to use on a large scale. For these reasons, in this thesis, catalysts mainly consisting of WOx with low content of Ru and Ir have been developed. Five different catalysts of the general form RuxIryW1-x-yOz have been synthesized starting from RuCl3, IrCl3, WCl6 and EtOH in a three-step synthesis. These catalysts were characterized by UV-Vis spectroscopy, XRD, Raman spectroscopy, SEM and TEM, and their electrocatalytic performance was evaluated using Linear Sweep Voltammetry (LSV), Electrochemical Impedance Spectroscopy (EIS) and Cyclic Voltammetry (CV). SEM and TEM showed that the catalysts had a sphere-like morphology with some crystalline features, while Raman and XRD confirmed that the catalysts contained RuO2, IrO2 and WOx. The key findings of the electrochemical analysis were that the catalysts with increased Ir content compared to Ru and W performed better than commercial IrO2 in terms of current density and overpotential, while increased Ru content compared to Ir and W showed negligible improvement of the catalyst performance. The catalysts with increased Ru content also performed worse than commercial IrO2. The best performing catalyst, Ru0.1Ir0.3W0.6Ox, was also stability tested. The stability test showed that the catalyst was only stable for around 15 minutes. In addition to the poor stability, the electrochemical performance in terms of current density and overpotential of the catalysts are worse than the best performing materials already reported in literature.
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(2024)This master’s thesis reviews the relatively rare class of organic compounds known as mixed geminal dihalides, in which a single carbon atom is bonded to two different halogen atoms. Synthesizing this functional group is a challenging chemical transformation, for which the methodology is still scarce. Chapter four outlines fifteen distinct approaches, condensing key information from a comprehensive literature review. Together these methods provide a relatively large scope for producing compounds with the desired mixed geminal dihalide functionality. Often, but not always, utilizing the electronic properties and reactivity of adjacent carbonyl groups. Several applications for these versatile synthons are presented in chapter three, most of which rely on differences in the leaving group tendencies among halogen atoms. Utilizing this property, these compounds are often employed in the formation of new carbon-carbon bonds. Another important class of applications involves the generation of carbon radicals. For example, in our laboratory, geminal bromoiodo alkanes were exposed to laser irradiation at a specific wavelength to produce the desired iodine-containing radicals for further reactions. The experimental section focuses primarily on the synthesis of vinyl bromides as starting materials and their iodination under acidic conditions. The scope of the literature review is much broader, encompassing all four halogens in all possible combinations. However, the experimental findings highlight an important property of mixed geminal dihalides: their separation is often challenging. Less sophisticated synthetic routes tend to yield mixtures of dihalogenated products that may be even impossible to separate using standard methods. This practical issue stems from the electronic configuration, which causes different halogens to exhibit relatively similar physicochemical properties, with fluorine being a notable exception.
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(2024)In the first part of this thesis, the usage of sodium dodecyl sulfate (SDS) as a micelle in micellar electrokinetic chromatography (MEKC) combined with ultra-violet (UV) detection is explored. This section provides a literature overview of 66 studies from 2011 to 2023, highlighting the versatility of the method with applications in diverse matrices, including beverages, food products, pharmaceuticals, and cosmetics. Despite the method’s advantages—such as cost-effectiveness and minimal reagent consumption—limitations, including low sensitivity with UV detection, are also addressed. Future directions for improving MEKC, such as incorporating alternative surfactants or detectors, are discussed. The experimental part investigates interactions between liposome membranes and derivatives of butenafine, an antifungal agent, using capillary electrochromatography (CEC). Originally intended to employ liposome electrokinetic capillary chromatography (LEKC), practical limitations led to the adoption of open-tubular CEC (OT-CEC) method, which employs liposomes as a coating, that acts as an stationary phase. This study successfully determined the distribution coefficients (log K) for two butenafine derivatives and demonstrated the influence of structural modifications on drug-membrane interactions. The results of this study contribute to the understanding of current state of SDS-MEKC methodologies and provide a basis for future advancements in drug-liposome interaction studies, with potential implications for pharmaceutical drug development.
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(2024)The theme of the thesis was the role of ionic liquids in liquid chromatography. Ionic liquids have several different types of functionalities, which means that they are prone to have multiple simultaneous interactions with the stationary and mobile phases of liquid chromatography. Ionic liquids have been used as analytes, mobile phase additives and column stationary phase modifiers. All these applications exploit the diversity of interactions with the different phases in liquid chromatography. Common roles of ionic liquids as mobile phase additives have been to reduce unwanted silanol effects with the column stationary phase, to act ion pair reagents to separate polar compounds with reversed phase chromatography and to act as UV absorption reagents to detect compounds that do not absorb UV light. The aim of the experimental work was to develop a liquid chromatography method to separate and quantitate a superbase ionic liquid and its hydrolysis products. Another task was to get familiar with the interactions with different column stationary and mobile phases. Columns with different stationary phase types were tested for this application and one column type was used for the quantitation of the superbase and its hydrolysis products. Preliminary experiments were also done to get an understanding on how to separate a difficult sample mixture containing compounds with both hydrophilic and hydrophobic compounds.