Incineration is a mainstream strategy for solid waste management in Sweden and all over the world. Improved knowledge and understanding about the distribution of trace elements (in ashes) during incineration, and how trace element partitioning respond to the changes in waste composition, are important in terms of combustion process optimization and plant efficiency. Moreover, determination of chemical association of trace elements in ashes are vital for avoiding environmental concerns and to promote possible reuse. In this study, partitioning of trace elements in ashes during incineration as function of input waste fuel and incineration technology was investigated. Further, chemical association of trace elements in resulting ashes was studied. An evaluation was also performed about feasibility of metal extraction from sulfidic mining waste and flotation tailings. Moreover, green liquor dreg (GLD) was tested with respect to stabilization of metals within the sulfidic mining waste. Findings showed that the total input of trace elements and chlorine affects the partitioning and increasing chlorine in the input waste caused increase in transfer of trace elements to fly ash especially for lead and zinc. Vaporization, condensation on fly ash particles and adsorption mechanisms play an important role for metal distribution. Firing mixed waste, especially biofuel mix, in grate or fluidized (CFB) boilers caused increased transfer into fly ash for almost all trace elements particularly lead and zinc. Possible reasons might be either an increased input concentration of respective element in the waste fuel, or a change in volatilization behavior due to the addition of certain waste fractions. Chemical association study for fly ashes indicated that overall, Cd, Pb, Zn, Cu and Sb are presenting major risk in most of the fly ashes, while in bottom ashes, most of elements are associated with stable fraction. Further, fuel type affects the association of elements in ashes. Chemical leaching of mining waste materials showed that sulfuric acid (under different conditions) is the best reagent to recover zinc and copper from sulfidic mining waste and also copper from flotation tailings. GLD indicates potential for metal stabilization in mining waste by reducing the metal mobility. Extraction methods could be applied to treat mining waste in order to meet the regulatory level at a specific mining site.Similarly stabilization/solidification  methods might be applied after leaching for recovery of metals.

There are multiple applications for polymers: our bodies are built of them, plastic bags and boxes used for storage are composed of them, as are the shells for electronics, TVs, computers, clothes etc. Many polymers are cheap, and easy to manufacture and process which make them suitable for disposable systems. The choice of polymer to construct an object will therefore highly influence the properties of the object itself. The focus of this thesis is the application of commonly used polymers to solve some challenges regarding integration of electrodes in electrokinetic devices and 3D printing. The first part of this thesis regards electrokinetic systems and the electrodes’ impact on the system. Electrokinetic systems require Faradaic (electrochemical) reactions at the electrodes to maintain an electric field in an electrolyte. The electrochemical reactions at the electrodes allow electron-to-ion transduction at the electrode-electrolyte interface, necessary to drive a current at the applied potential through the system, which thereby either cause flow (electroosmosis) or separation (electrophoresis). These electrochemical reactions at the electrodes, such as water electrolysis, are usually problematic in analytical systems and systems applied in biology. One solution to reduce the impact of water electrolysis is by replacing metal electrodes with electrochemically active polymers, e.g. poly(3,4-ethylenedioxythiophene) (PEDOT). Paper 1 demonstrates that PEDOT electrodes can replace platinum electrodes in a gel electrophoretic setup. Paper 2 reports an all-plastic, planar, flexible electroosmotic pump which continuously transports water from one side to the other using potentials as low as 0.3 V. This electroosmotic pump was further developed in paper 3, where it was made into a compact and modular setup, compatible with commercial microfluidic devices. We demonstrated that the pump could maintain an alternating flow for at least 96 h, with a sufficient flow of cell medium to keep cells alive for the same period of time. The second part of the thesis describes the use of 3D printers for manufacturing prototypes and the material requirements for 3D printing. Protruding and over-hanging structures are more challenging to print using a 3D printer and usually require supporting material during the printing process. In paper 4, we showed that polyethylene glycol (PEG), in combination with a carbonate-based plasticizer, functions well as a 3D printable sacrificial template material. PEG2000 with between 20 and 30 wt% dimethyl carbonate or propylene carbonate have good shear-thinning rheology, mechanical and chemical stability, and water solubility, which are advantageous for a supporting material used in 3D printing. The advances presented in this thesis have solved some of the challenges regarding electrokinetic systems and prototype manufacturing. Hopefully this will contribute to the development of robust, disposable, low-cost, and autonomous electrokinetic devices. / Polymera material finns överallt omkring oss; våra kroppar är uppbyggda av dem,plastpåsarna och burkarna vi förvarar vår mat av består av dem, våra kläder och andra tingsom finns i vår vardag är uppbyggda av olika typer av polymerer. En polymer är uppbyggd aven repetitiv sekvens av identiska grupper, de kan liknas vid en mönsterrapport vilken är denminsta del som man behöver repetera för att få mönstret. Beroende på hur rapporten ser ut såförändras utseendet av mönstret. Hos en polymer påverkar sammansättningen av denrepetitiva gruppen (rapporten) egenskaperna av materialet och polymerer kan vara allt frånhårda och robusta, till flexibla och elektriskt ledande. Arbetet som presenteras i den häravhandlingen berör hur funktionen av olika system påverkas av att man använder sig avpolymerer istället för konventionella material. Första delen av avhandlingen handlar om integrering av elektronik i system som innehållervätska. När vätskor, laddade partiklar, molekyler och joner rör på sig på grund av ett yttreelektriskt fält, så kallas detta för elektrokinetik. Detta kan användas för att pumpa vätska ikanaler som är mindre än 0.2 mm, genom så kallad elektroosmos, samtidigt kommermolekyler med olika laddning att börja separera, så kallad elektrofores. Elektroosmos användsinom t.ex. analytisk kemi för injektion och transport av vätskor. Elektrofores används inombl.a. rättsvetenskap och molekylärbiologi för att separera makromolekyler, så som DNA ochproteiner, med avseende på deras storlek och laddning. I dessa system använder man sig oftastav metallelektroder. När en spänning läggs till ett par metallelektroder som är i kontakt med vatten kommer denhuvudsakliga reaktionen att vara spjälkning av vatten, så kallad vattenelektrolys. Spjälkningav vatten innebär att det bildas vät-och syrgas samt att pH börjar ändras. Gaserna som bildaskan bryta kopplingen mellan elektroderna och därmed stoppar strömmen, så som sker när mandrar ut sladden för t.ex. en elvisp. Förändringar i pH kan t.ex. påverka biologiska provernegativt, så som proteiners funktion och kan leda till celldöd, men kan också minska flödenaen elektroosmotisk pump kan generera. Det finns flera olika sätt hur man kan hanteravattenelektrolys i system med metallelektroder, så som användning av en pH-buffer. Arbetet iden här avhandlingen visar vad som händer om man ersätter metallelektroder med elektrisktledande plastelektroder. I detta fall har metallelektroderna ersatts av den elektriskt ledandepolymeren PEDOT vilket resulterar i att , där man istället för generera gas och pHviförändringar, så förflyttar man joner mellan elektroden och omgivande lösning. Ledandepolymerer är billiga och enkla att tillverka vilket gör dem lämpliga för engångssystem. förändringar, så förflyttar man joner mellan elektroden och omgivande lösning. Ledandepolymerer är billiga och enkla att tillverka vilket gör dem lämpliga för engångssystem.I den här avhandlingen visas följande exempel där metallelektroder ersatts av ledandeplastelektroder: Gelelektrofores (separation av proteiner i en gel), (se papper 1), tyg som kanpumpa vatten (plan elektroosmotisk pump, se papper 2) och en kompakt pump som inte ärstörre än ett kaffemått, som enkelt kan kopplas till befintliga sprutkopplingar och som kananvändas för att kontrollera flödet över t.ex. celler (se papper 3). Andra delen av avhandlingen handlar om 3D skrivare och hur materialval påverkarutskriften och designen. 3D skrivare är ett bra alternativ för att snabbt och billigt kunnaproducera prototyper och funktionella individanpassade objekt i varierande storlekar.3D skrivare kan beskrivas som en avancerad spritsmaskin där material läggs lager på lager föratt bygga upp det slutgiltiga objektet utifrån en datorgenererade 3D model. Detta förändrarhelt hur man designar objekt och vilka möjliga strukturer och material man kan använda sigav jämfört än då man till exempel använder sig av svarv eller fräs för tillverkning. Det finnsflera olika typer av 3D skrivare, t.ex. smältplastskrivare (den typ som man kan se i flertaletaffärer idag) och den variant som använts i den här avhandlingen, en sprutbaserad. Ensprutbaserad 3D skrivare kan hantera många olika typer av material så länge dessa kan fyllas ien spruta och tryckas ut genom en nål. Det färdiga resultat kan därmed bli mycket olikaberoende på vilka material som använts. Överhängande och utstickande strukturer kan vara komplicerade att skriva ut med en3D skrivare. Utskrift av dessa strukturer kan underlättas genom att man skriver ut en temporärstruktur i ett annat material, ett offermaterial. Offermaterialet fungerar som en mall eller stödtill det slutgiltiga objektet och tas bort (offras) när övriga delar av objektet är klara. I den häravhandlingen beskrivs hur ett offermaterial baserat på polyetylen glykol (PEG, vanligtförekommande i t.ex. schampo och läkemedel) och en mjukgörare kan anpassas för attfungera tillsammans med en sprutbaserad 3D skrivare (se papper 4) för att skriva ut strukturerfrån 0,2 mm och uppåt. Arbetet i den här avhandlingen visar användningen av den ledande polymeren PEDOT i ettelektroforessystem och en elektroosmotisk pump. Detta kan förhoppningsvis underlättautvecklingen av dessa system till att bli mindre, smidigare, snabbare och billigare. Den andradelen presenterar ett vattenlösligt, PEG-baserat material som kan användas som stöd till andramaterial i sprutbaserade 3D utskrifter för att underlätta tillverkningen av 3D utskrivna objekt.

The aim of this study was to investigate the utility of direct analysis in real time quadrupole time-of-flight mass spectrometry and gas chromatography quadrupole time-of-flight mass spectrometry in the analysis of 162 different synthetic cannabinoids. Direct analysis in real time quadrupole time-of-flight mass spectrometry is shown to be a rapid and accurate analytical method for synthetic cannabinoids. Spectra can be generated with less than 1.5 ng of the drug in under a minute and be successfully searched against previously generated ESI-QTOF libraries in most cases (118/130 drugs tested) as well as can also be applied to the identification of synthetic cannabinoids in a mixture. Gas chromatography quadrupole time-of-flight mass spectrometry, while requiring a much longer analysis time, is shown to accurately distinguish all but 19 compounds (140/159). These two instruments have proven to be viable alternatives in synthetic cannabinoid analysis and will greatly benefit forensic laboratories.

Mangos (Mangifera indica L.) are tropical/subtropical fruits belonging to the plant family Anacardiaceae. Anthracnose is the most deleterious disease of mango both in the field and during postharvest handling. It is most commonly caused by the Colletotrichum gloeosporioides complex. Mangiferin, a xanthanoid compound found in at least twelve plant families worldwide (Luo et al., 2012), is present in large amounts of the leaves and edible mangos. Even though this compound plays a pivotal role in the plant’s defense against biotic and abiotic stressors, no correlations been made between the compound and mango anthracnose resistance. Mangos were collected, grouped according to their countries of origin, and evaluated for their mangiferin concentrations at four different stages of development. Extracts of interest were then tested against different strains of C. gloeosporioides. The results demonstrated that mangiferin concentrations are significantly different at different stages in fruit development. The antifungal assays were inconclusive.

Human scent has been the focal point of diverse scientific interests and research initiatives for the past several years. The knowledge gained about its composition has favored the advancement of multiple disciplines, and promoted the development of a wide variety of applications. Among these applications is the use of human scent as a resource for Forensic investigations, where scent profiles are often used as evidence to associate individuals to the scene of a crime. The characteristic nature of individual human scent has enabled this type of evidence to be used as a biometric tool for the differentiation of subjects. Nevertheless, the present study discusses a new perspective towards human scent's role and application in Forensic investigations. The foundation of this new perspective consists of employing human scent’s biometric quality to classify individuals using common traits. In this research study, underarm and hand odor samples were collected from Caucasian, Hispanic and East Asian individuals, of both genders. Subjects were also organized into 3 different age groups: 18-30, 35-50 and 55+ years. Headspace Solid Phase Micro-extraction Gas Chromatography Mass Spectrometry (HS-SPME-GC-MS) was used to create individual scent profiles for the evaluation of subject classification by age, gender and race/ethnicity. Individual classification was assessed through the identification of qualitative and quantitative patterns in the volatile organic compound (VOC) constituents that characterize human scent. Principal Component and Linear Discriminant analyses of the collected scent profiles, led to the identification and validation of characteristic VOC marker combinations for age, gender and race/ethnicity. Statistical analysis facilitated group classification and differentiation on the basis of these traits. Moreover, this study also evaluated the use of solvent extraction as a complementary technique to HS-SPME for human scent analysis. Findings from this assessment revealed that the simultaneous consideration of data from both extraction techniques favors an enhancement of the classification of subjects by means of human scent. The discoveries achieved in this study represent a significant step for human scent as a forensic tool. The outcome of this research has cleared a new path for further human scent investigation, and highlighted its further relevance to forensic applications.

The goal of this project was to develop a rapid separation and detection method for analyzing organic compounds in smokeless powders and then test its applicability on gunshot residue (GSR) samples. In this project, a total of 20 common smokeless powder additives and their decomposition products were separated by ultra performance liquid chromatography (UPLC) and confirmed by tandem mass spectrometry (MS/MS) using multiple reaction monitoring mode (MRM). Some of the targeted compounds included diphenylamines, centralites, nitrotoluenes, nitroglycerin, and various phthalates. The compounds were ionized in the MS source using simultaneous positive and negative electrospray ionization (ESI) with negative atmospheric pressure chemical ionization (APCI) in order to detect all compounds in a single analysis. The developed UPLC/MS/MS method was applied to commercially available smokeless powders and gunshot residue samples recovered from the hands of shooters, spent cartridges, and smokeless powder retrieved from unfired cartridges. Distinct compositions were identified for smokeless powders from different manufacturers and from separate manufacturing lots. The procedure also produced specific chemical profiles when tested on gunshot residues from different manufacturers. Overall, this thesis represents the development of a rapid and reproducible procedure capable of simultaneously detecting the widest possible range of components present in organic gunshot residue.

While the spin trapping properties of thiols have been investigated through EPR analysis and kinetics studies, few groups have studied these properties using strictly computational methods. In particular, α-lipoic acid (ALA) and its reduced form, dihydrolipoic acid (DHLA), one of the strongest endogenously produced antioxidants, show potential for being effective, naturally occurring spin traps for the trapping of reactive oxygen species. This research covers electronic structure calculations of ALA, DHLA, and their corresponding hydroxyl radical spin adducts, performed at the cc-pVDZ/B3LYP/DFT level of theory. The effects on DHLA introduced by other radicals such as ·OOH, ·OCH3, and ·OOCH3 are reported. Explicit solvation was carried out using open-source molecular packing software and was studied using MOPAC PM6 semi-empirical geometry optimizations. Complete Basis Set (CBS) limit extrapolations were performed using cc-pVXZ (X = D, T, Q) Dunning basis sets under the DFT/B3LYP level of theory, and results are compared to the literature.

Plastic pollution is one of if not the biggest threat against earth’s ecosystems. Almost 400 million tons of plastic is produced every year and most of it is discarded outside of the recycling systems. Marine ecosystems are extra exposed due to microplastics which are plastic smaller than 5 mm. The most common type of plastic is PET. Plastic in general is very chemically stable and hard to degrade but scientists have found a bacterium named I.sakaiensis that can degrade PET with a two-enzyme system called PETase and MHETase. Due to being exo-enzymes, they have to be secreted to function, the thermostability of these enzymes are very low so most research has been focused on increasing the thermal stability with its enzyme activity. This report focuses on what structures are important for the PET degrading ability of MHETas and PETas and how they can be applied to cleaning marine ecosystems. A key to solving environmental issues is creating environmentally aware students through the education system. Studies about Context based education have indicated that it sparks motivation and interest in students and the lessons seem more relevant. This report is also about how context-based education can be used to create an environmental perspective in secondary education.

The state-of-the-art tools for machining metals are primarily based on a metal-ceramic composite(WC-Co) coated with different combinations of carbide, nitride and oxide coatings. Combinations of these coating materials are optimized to withstand specific wear conditions. Oxide coatings are especially desired because of their possible high hot hardness, chemical inertness with respect to the workpiece, and their low friction. This thesis deals with process and coating characterization of new oxide coatings deposited by physical vapor deposition (PVD) techniques, focusing on the Cr-Zr-O and Al-Cr-Si-O systems. The thermal stability of α-Cr0.28Zr0.10O0.61 deposited by reactive radio frequency (RF)-magnetron sputtering at 500 °C was investigated after annealing up to 870 °C. The annealed samples showed transformation of α-(Cr,Zr)2O3 and amorphous ZrOx-rich areas into tetragonal ZrO2 and bcc Cr. The instability of the α-(Cr,Zr)2O3 is surprising and possibly related to the annealing being done under vacuum, facilitating the loss of oxygen. The stabilization of the room temperature metastable tetragonal ZrO2 phase, due to surface energy effects, may prove to be useful for metal cutting applications. The observed phase segregation of α-(Cr,Zr)2O3 and formation of tetragonal ZrO2 with corresponding increase in hardness for this pseudo-binary oxide system also opens up design routes for pseudo-binary oxides with tunable microstructural and mechanical properties. The inherent difficulties of depositing insulating oxide films with PVD, demanding a closed circuit, makes the investigation of process stability an important part of this research. In this context, we investigated the influence of adding small amount of Si in Al-Cr cathode on plasma characteristics ,process parameters, and coating properties. Si was chosen here due to a previous study showing improved erosion behavior of Al-Cr-Si over pure Al-Cr cathode without Si incorporation in the coating. This work shows small improvements in cathode erosion and process stability (lower pressure and cathode voltage) when introducing 5 at % Si in the Al70Cr30-cathode. This also led to fewer droplets at low cathode current and intermediate O2 flow. A larger positive effect on cathode erosion was observed with respect to cleaning the cathode from oxide contamination by increasing cathode current with 50%. However, higher cathode current also resulted in increased amount of droplets in the coating which is undesirable. Through plasma analysis the presence of volatile SiO species could be confirmed but the loss of Si through volatile SiO species was negligible, since the coating composition matched the cathode composition. The positive effect of added Si on the process stability at the cathode surface should be weighed against Si incorporation in the coating. This incorporation may or may not be beneficial for the final application since literature states that Si promotes the metastable γ-phase over the thermodynamically stable α-phase of pure Al2O3, contrary to the effect of Cr, which stabilizes the α-phase.

Modeling of the nitrogen cycling in the sediments of the Baltic Sea is the major objective of thepresent study. A model of the nitrogen cycling in the sediment of the Western Gotland Basinwas developed. The model simulates the sedimentary biogeochemical processes such asdecomposition of the organic detritus and transformation of nitrogen species in the sediment.The development of the model is based on the methods and approaches implemented in themodel of the freshwater Haringvliet Lake, Netherland. The sediments of Haringvliet and the Baltic Sea were examined in terms of the interactions andcontrols of biogeochemistry. Both systems are eutrophied. This results in a high sedimentationrate of organic matter and creates the same chemical and physical conditions to theirsediments. However, the sedimentation rate and decomposition of organic detritus is higherand nitrification and denitrification is lower in Haringvliet lake system compared to the BalticSea. The results of the model tests show that profiles of the chemical compounds and rates of theprocesses are in good agreement with the observations made in different areas of the BalticSea. The model can be used for simulation of the sediment processes when there is a constantinput of organic matter. The model can also reproduce the behavior of the sediment whensome of the process parameters and conditions are changed. A comparison of the rates of the biogeochemical processes predicted by model and thosemeasured in the different basins of the Baltic Sea was performed. The rates of decompositionof organic detritus, denitrification and nitrification were in agreement with the field data. Basedon the results of the model the nitrogen removal in the sediment was calculated and it wasfound that 26-32% of total nitrogen entering the sediment is removed by denitrification. / <p>www.ima.kth.se</p>