Metallic glasses exhibit many attractive attributes such as outstanding mechanical, magnetic, and chemical properties. Due to the absence of crystal defects, metallic glasses display remarkable mechanical properties including higher specific strength than crystalline alloys, high hardness and larger fracture resistance than ceramics. The technological breakthrough of metallic glasses, however, has been greatly hindered by the limited plastic strain to failure. Thus, several strategies have been employed to improve the intrinsic and extrinsic effects on the flow behavior of metallic glasses with respect to their fracture toughness and overall plastic strain. One of the suggested strategies is the production of a composite consisting of the brittle metallic glass along with a ductile second phase that either acts as an active carrier of plastic strain or passively enhances the multiplication of shear bands via shear-band splitting . Another approach for increasing plastic deformation consists of introducing pores as a gaseous second phase into the material. The pores are similarly effective in delaying catastrophic failure resulting from shear band localization. In metallic glasses with high porosity, propagation of shear bands can even become stable, enabling macroscopic compressive strains of more than 80 % without fracture. In this thesis, Ni59Zr20Ti16Si2Sn3 glass and its composites have been fabricated using mechanical milling and consolidation by hot pressing followed by extrusion of Ni59Zr20Ti16Si2Sn3 metallic glass powder or Ni59Zr20Ti16Si2Sn3 metallic glass powder reinforced with 40 vol.% of brass particles to obtained bulk composite materials with high strength and enhanced compressive plasticity and to generate porous structure in Ni59Zr20Ti16Si2Sn3 metallic glass using selective dissolution. The brass–glass powder mixtures to be consolidated were prepared using two different approaches: manual blending and ball milling to properly vary size and morphology of the second phase in the composites. Powder consolidation was carried out at temperatures within the supercooled Liquid (SCL) region, where the glassy phase displays a strong decrease of viscosity, with using the sintering parameters which were chosen after analysis of the crystallization behavior of the glassy phase to avoid its crystallization during consolidation. Ball milling has a significant effect on the microstructure of the powder mixtures: a refined layered structure consisting of alternating layer of glass and brass is formed as a result of the mechanical deformation. However, ball milling reduces the amorphous content of the composite powders due to mechanically induced crystallization and reaction of the glass and brass phases during heating. In addition, the milling of the composite powders and the following consolidation step reduces the amorphous content by about 50 %. The bulk amorphous Ni59Zr20Ti16Si2Sn3 alloy synthesized by hot pressing exhibits higher strength (2.28 GPa) than that of the as-cast bulk amorphous Ni59Zr20Ti16Si2Sn3 alloy (2.2 GPa). The mechanical behavior of the glass-brass composites is significantly affected by the control of the microstructure between the reinforcement and the nano-grained matrix phase through the different methods used for the preparation of the powder mixtures. The strength of the composites increases from 500 MPa for pure brass to 740 and 925 MPa for the composites with 40 and 60 vol.% glass reinforcement prepared by manual blending. The strength further increases to 1240 and 1640 MPa for the corresponding composites produced by ball milling caused by the remarkable effect of the matrix ligament size on the strengthening of the composites. The porous metallic glass was obtained by the selective dissolution in a HNO3 solution of the fugitive brass phase in the Ni59Zr20Ti16Si2Sn3 composite. The microstructure of the porous samples consists of highly elongated layered pore structures and/or irregularly shaped pores. The average size of the pores depends on the processing parameters and can be varied in the range of 0.4–15 µm. Additional porous samples were prepared from different extruded composite precursors of blended and milled powder mixtures. This leads to customized hybrid porous structures consisting of a combination of large and small pores. The specific surface area of the porous Ni-based metallic glass powder measured by the BET method is 16 m2/g, while the as-atomized Ni59Zr20Ti16Si2Sn3 powder has a specific surface area of 0.29 m2/g. This indicates a mechanical milling induced enhancement in surface area by refinement of the fugitive brass phase. However the specific surface area of the porous Ni-based metallic glass obtained from as-extruded precursors is 10 m2/g caused by a breakdown of the porous structure during selective dissolution of the nano-scale fugitive phase. Although milling of the present composite powders and the following consolidation step reduces the amorphous content by about 50 %, through the use of glassy phases with improved stability against mechanically induced crystallization along with reduced affinity with the fugitive phase to avoid unwanted reactions during processing, this approach using powder metallurgical offers the possibility to produce highly active porous bulk materials for functional applications, such as catalysis, which require the fast transport of reactants and products provided by the large pores along with high catalytic activity ensured by the large surface area characterizing the small pores. Accordingly, gas absorption ability tests of porous Ni-based metallic glass powders have been performed in order to evaluate the possibility of replacement of conventional support materials. From these first tests it can be conclude that additional opportunities should exist for nano-porous MGs with designed architecture of porous structures that are tailored to specific functional applications. / Metallische Gläser weisen viele attraktive mechanische, magnetische und chemische Eigenschaften auf. Aufgrund der fehlenden Kristallstruktur zeigen metallische Gläser bemerkenswerte mechanische Eigenschaften, einschließlich höherer spezifischer Festigkeit, höherer Härte und größerer Bruchfestigkeit als Keramik. Der technologischen Durchbruch metallischer Gläser wird jedoch bis heute stark von ihremspröden Bruchverhalten behindert. Deshalb wurden verschiedene Herstellungsverfahren entwirkt, um sowohl die plastische Verformung der metallischer Massivgläser zu erhöhen, als auch um die mechanischen Eigenschaften generell zu verbessern. Eine mögliche Methode, zur Erhöhung der Plastizität und zur Beeinflussung der mechanischen Eigenschaften der metallischen Gläser ist der Einbau zweiter Phasen, wie z.B. durch Fremdpartikel Verstärkung oder Poren in Kompositen. Die Scherband bewegung wird durch die Wechselwirkung mit zweiten Phasen behindert, und gleichzeitig werden durch die in den Grenzflächen entstehenden Spannungsspitzen zwischen der zweiten Phase und der Matrix neue Scherbänder initiert. Dies führt zur Bildung einer Vielzahl von Scherbändern, was eine höhere plastische Dehnung zur Folge hat, da die Deformationsenergie auf ein größeres Volumen verteilt wird. In der vorliegenden Arbeit wurden Ni59Zr20Ti16Si2Sn3 Massivglas und mit Messing- verstärkte Komposite durch Kugelmahlen und Heißpressen mit anschließender Extrusion von Ni59Zr20Ti16Si2Sn3 Pulver oder Ni59Zr20Ti16Si2Sn3 Pulver mit 40 vol.% Messing Partikeln hergestellt. Neben der Herstellung der Ni59Zr20Ti16Si2Sn3 Komposite mit Messing Partikeln, wurden auch Ni59Zr20Ti16Si2Sn3 Komposite mit definierter Porösität durch die selektive Auflösung der zweiten Phase erzeugt. Die verwendete Mischung von Messing und metallischem Glaspulver wurde über zwei verschiedene Ansätzen hergestellt: die Pulver wurden manuell gemischt oder gemahlen, um die optimale Größe und Morphologie der zweiten Phase in den Komositen zu erzeugen. Das Sintern der Pulver erfolgte bei Temperaturen im Bereich der unterkühlten Schmelze, wobei die Legierung eine starke Abnahme der Viskosität zeigte, mit Hilfe optimierter Sinterparameter, die nach der Analyse des Kristallisationsverhaltens der gläsernen Phase ausgewählt wurden, um deren Kristallisation während der Konsolidierung zu vermeiden. Kugelmahlen hat einen signifikanten Einfluss auf die Mikrostruktur der gemahlenen Pulver: Eine verfeinerte Lamellare Struktur, teils bestehend aus Glas und teils aus Messing, wird durch mechanische Verformung gebildet. Kugelmahlen reduziert jedoch den amorphen Anteil der Komposite durch mechanische induzierte Kristallisation und die Reaktion der Glas- und Messing- Phasen durch Erwärmung. Das Kugelmahlen der Komposite (Pulver) und das darauf folgende Sintern führte zur eine Absenkung der freien Enthalpie der amorphen Phase um ca. 50%. Ni59Zr20Ti16Si2Sn3 metallische Massivgläser, welche durch Heißpressen hergestellt werden, weisen eine höhere Streckgrenze von 2.28 GPa als das gegossene Ni59Zr20Ti16Si2Sn3 Massivglas (2.2 GPa) auf. Die mechanischen Eigenschaften der mit Messing Ni59Zr20 Ti16Si2Sn3 verstärkten Komposite sind abhängig von der Kontrolle der Mikrostruktur zwischen den zweiten Phasen und der Matrixphase durch die verschiedenen Verfahren zur Herstellung von Pulvermischungen. Die Festigkeiten der Komposite, welche durch Handmischen und Heißpressen mit nachfolgender Extrusion hergestellt wurden, erhöhten sich von 500 MPa für reines Messing bis auf 740 und 925 MPa für die Komposite mit 40 und 60 Vol. % Glaspartikel- Verstärkung durch Handmischen. Die Festigkeiten erhöhten sich nochmals auf 1240 und 1640 MPa für die Komposite mit 40 und 60 Vol. % an Glaspartikel-Verstärkung mit lamellare Stuktur, die durch Kugelmahlen hergestellt würden. Die Ursache hier für liegt in der Wirkung der Ligamentabmessungen zwischen den Matrixbestandteilen hinsichtlich der Verfestigung der Komposite. Die Porösität im metallischen Glas wurde durch die selektive Auflösung der flüchtigen Messingphasen in den Kompositen mit Salpetersäure-Lösung erhalten. Die Mikrostuktur der porösen metallischen Gläser besteht aus stark elongiert geschichteten Porenstrukturen und/oder unregelmäßig geformten Poren. Die durchschnittliche Größe einer Pore hängt von den behandelnden Parametern ab und kann von 0.4–15 µm variieren. Weitere poröse Proben wurden ausgehend von verschiedenen extrudierten Komposit-Precursoren aus handgemischten und kugelgemahlenen Pulvermixturen erzeugt. Dies führte zu angepassten hybrid-porösen Strukturen bestehend aus einer Kombination von großen und kleinen Poren. Die spezifische Oberfläche des porösen Glaspulvers gemessen mit Hilfe der BET- Methode, beträgt 16m2/g, wohingegen das atomisierte Ni59Zr20Ti16Si2Sn3 MG Ausgangspulver eine spezifische Oberfläche von 0.29 m2/g besitzt. Dies weist darauf hin, dass das Mahlen eine Vergrößerung der Oberfläche durch die Verfeinerung der flüchtigen Messingphase induziert. Die spezifische Oberfläche der porösen-metallischen Gläser beträgt 10 m2/g und entsteht durch die Zerstörung der porösen Struktur während der selektiven Auflösung der nanoskaligen flüchtigen Phase. Obwohl das Kugelmahlen der Komposite (Pulver) und die darauf folgende Konsolidierung zwar den amorphen Anteil um etwa 50% reduziert, bietet die Pulvermetallurgische Herstellung durch die Verwendung von gläsernen Phasen mit verbesserter Stabilität gegenüber mechanisch induzierter Kristallisation, sowie einer reduzierten Affinität mit der flüchtigen Messingphase zur Vermeidung von unerwünschten Reaktionen während des Prozesses eine Möglichkeit, hochaktive poröse metallische Gläser für funktionelle Anwendungen, wie z.B. Katalyse, zu entwickeln. Hier ist eine schnelle Transport von Reaktanten und Produkten, welcher von den großen Poren, sowie eine hohe katalytische Aktivität, die von kleinen Poren und einer großen Oberfläche sichergestellt wird wesentlich. Daher wurden Untersuchungen zur Gasabsorptionsfähigkeit von porösem metallischen Glaspulver durchgeführt, um die Möglichkeit der Ersetzung von konventionellen Trägermaterialen bewerten zu können. Diese ersten Versuche zeigen die grundsäLzliche Eignung nano poröse metallischer Gläser zur Herstellung von porösen Strukturen mit einstellbarer Porenarchitektur auf die Langfristig für spezifische funktionelle Anwendungen von Interesse sein könnten.

Polyhalite is an abundant distributed mineral in rock salt formations, and considered to respond as a natural heavy metal sink because the Mg2+ ion can be substituted by other bivalent metal ions like Mn2+, Co2+, Ni2+, Cu2+ and Zn2+. One of the quantities needed to predict mineral solubilities in multi-electrolyte solutions is the solubility constant Ksol. Since polyhalite forms slowly over months or years at 298 K, the solid-liquid phase equilibria experiments were accomplished at 313 K. Enthalpies of dissolution were measured and used to extrapolate lnKsol from 313 K to 298 K. Pitzer’s equations have been applied to describe activities of solute and water, with Pitzer parameters estimated from experimental data. The solubility constants for the polyhalites were applied to calculate the solubility equilibria in the quaternary systems K+, M2+, Ca2+ / SO42- // H2O (M = Mg, Mn, Co, Cu, Zn) at 298 K and 313 K, and in case of Mg-polyhalite also in the hexary system Na+, K+, Mg2+, Ca2+ / Cl-, SO42- // H2O.

Jan Wallentin. Vägar till samadhi : en granskning av Robert K. C. Formans begrepp ”Pure Consciousness Event” (Roads to Samadhi : An Examination of Robert K. C. Forman’s Concept of ”Pure Consciousness Event”). Umeå University: Department of Historical, Philosophical and Religious studies. Bachelor thesis. June 2021.Is Robert K. C. Forman’s concept of ”pure consciousness event” an example of a universal,mystical core experience? Is it possible to establish the neural correlates of this proposedexperience, and to induce it experimentally? These are the main questions of this study,which is a literature review drawing on recent scientific research from three fields: religious studies, philosophy of consciousness and neuroscience.The major findings are:The concept of ”pure consciousness event” (PCE) does seem like a tenable way ofgetting around the constructivist critique regarding universal, mystical core experiences.However, Forman’s original definition of PCE seems too strict. Forman defines PCE as ”a wakeful though contentless (non-intentional) consciousness”, but in the conventional wisdom of contemporary philosophy it is deemed impossible to be conscious without beingconscious about something. A conceivable solution would be to replace the term ”PCE” withThomas Metzinger’s less strict term ”Minimal Phenomenal Experience” (MPE), whichallows for some, though minimal, mental content during these kind of experiences.Regarding neural correlates, several recent studies suggest that a high level of activityin the brain’s default mode network (DMN) is correlated with a heightened sense of self-awareness. A low level of activity in the DMN is, vice versa, correlated with a sense of self-forgetting, as in the flow-experience. However, the activity-level of the DMN does not seem to fully explain the proposed existence of pure consciousness events, even in a less strict definition of this term.Methods used to induce experiences reminiscent of PCE include the white dreams ofTibetan dream yoga (yoga nidrā), states of deep meditation, and the intake of psychoactive substances, like psilocybin, DMT and LSD.Keyterms: Robert K. C. Forman, pure consciousness event, mysticism, samadhi, philosophy of consciousness,Thomas Metzinger, minimal phenomenal experience, drug induced ego dissolution.

The thesis compares two different modes of state disintegration of post-communist federations. Yugoslavia is an example of a violent breakup, Czechoslovakia stands for a peaceful way, how to split a state. Using the Level of Analysis concept the study looks for differences at five levels focusing mainly on the change caused by the process of democratic transition in both states that removed the old regime and brought a competitive atmosphere among the old and new elites representing various ethnic groups. The outcome of the analysis is that the role of the army, the length of the liberalization process and the different historical experience are factors that matter most.

Ceria (cerium oxide) nanomaterials, or nanoceria, have commercial catalysis and energy storage applications. The cerium atoms on the surface of nanoceria can store or release oxygen, cycling between Ce3+ and Ce4+, and can therefore act as a therapeutic to relieve oxidative stress within living systems. Nanoceria dissolution is present in acidic environments in vivo. In order to accurately define the fate of nanoceria in vivo, nanoceria dissolution or stabilization is observed in vitro using acidic aqueous environments. Nanoceria stabilization is a known problem even during its synthesis; in fact, a carboxylic acid, citric acid, is used in many synthesis protocols. Citric acid adsorbs onto nanoceria surfaces, capping particle formation and creating stable dispersions with extended shelf lives. Nanoceria was shown to agglomerate in the presence of some carboxylic acids over a time scale of up to 30 weeks, and degraded in others, at pH 4.5 (representing that of phagolysosomes). Sixteen carboxylic acids were tested: citric, glutaric, tricarballylic, α-hydroxybutyric, β-hydroxybutyric, adipic, malic, acetic, pimelic, succinic, lactic, tartronic, isocitric, tartaric, dihydroxymalonic, and glyceric acid. Each acid was introduced as 0.11 M, into pH 4.5 iso-osmotic solutions. Controls such as ammonium nitrate, sodium nitrate, and water were also tested to assess their effects on nanoceria dissolution and stabilization. To further test stability, nanoceria suspensions were subject to light and dark milieu, simulating plant environments and biological systems, respectively. Light induced nanoceria agglomeration in some, but not all ligands, and is likely to be a result of UV irradiation. Light initiates free radicals generated from the ceria nanoparticles. Some of the ligands completely dissolved the nanoceria when exposed to light. Citric and malic acids form coordination complexes with cerium on the surface of the ceria nanoparticle that can inhibit agglomeration. This approach identifies key functional groups required to prevent nanoceria agglomeration. The impact of each ligand on nanoceria was analyzed and will ultimately describe the fate of nanoceria in vivo. In addition, simulated biological fluid (SBF) exposure can change nanoceria’s surface properties and biological activity. The citrate-coated nanoceria physicochemical properties such as size, morphology, crystallinity, surface elemental composition, and charge were determined before and after exposure to simulated lung, gastric, and intestinal fluids. SBF exposure resulted in either loss or overcoating of nanoceria’s surface citrate by some of the SBF components, greater nanoceria agglomeration, and small changes in the zeta potential. Nanocomposites are comprised of a polymer matrix embedded with nanoparticles. These nanoparticles can alter material and optical properties of the polymer. SR-399 (dipentaerythritol pentaacrylate) is a fast cure, low skin irritant monomer that contains five carbon-carbon double bonds (C=C). It is a hard, flexible polymer, and also resistant to abrasion. It can be used as a sealant, binder, coating, and as a paint additive. In this case, metal oxide nanoparticles were added to the monomer prior to polymerization. Titania nanoparticles are known to absorb UV light due to their photocatalytic nature. Titania nanoparticles were chosen due to their high stability, non-toxicity, and are relatively quick, easy, and inexpensive to manufacture. Channels in thin monomer films were created using a ferrofluid manipulated by magnetic fields. The mechanical properties of a microfluidic device by rapid photopolymerization is dependent on the crosslinking gradient observed throughout the depth of the film. Quantitative information regarding the degree of polymerization of thin film polymers polymerized by free radical polymerization through the application of UV light is crucial to estimate material properties. In general, less cure leads to more flexibility, and more cure leads to brittleness. The objective was to quantify the degree of polymerization to approximate the C=C concentration and directly relate it to the mechanical properties of the polymer. Polymerization of C=C groups was conducted using a photoinitiator and an UV light source from one surface of a thin film of a multifunctional monomer. The C=C fraction in the film was found to vary with film depth and UV light intensity. The extents of conversion and crosslinking estimates were compared to local mechanical moduli and optical properties. A mathematical model linking the mechanical properties to the degree of polymerization, C=C composition, as a function of film depth and light intensity was then developed. For a given amount of light energy, one can predict the hardness and modulus of elasticity. The correlation between the photopolymerization and the mechanical properties can be used to optimize the mechanical properties of thin films within the manufacturing and energy constraints, and should be scalable to other multifunctional monomer systems.

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Koldioxidutsläpp (CO2) från energiproduktionsindustrin och transportsektorn globalt påverkar miljön negativt. Länder har enats om att minska utsläppen för att nå målet om en genomsnittlig temperaturökning på 1,5 °C till 2030. Trots detta förväntas de globala utsläppen av CO2 från fossila bränslen och industriella processer vara cirka 40 Gton per år fram till 2100. För att dra nytta av CO2-utsläppen och skapa värdefulla produkter med negativa utsläpp är mineralkarbonatisering en önskvärd process. Denna process innebär att CO2 och mineraler löses upp i en alkalisk lösning och bildar stabila produkter. Faktorer som partikelstorlek hos mineralerna och CO2-lösningshastigheten påverkar mineralkarbonatiseringens hastighet. Experiment utfördes med en batchreaktor från Paebbl AB och en matematisk modell utvecklades i Matlab. Resultaten jämfördes för olika partikelstorlekar i tre motståndsfall. Större partikelstorlek hos olivin visade sig öka tiden för total konvertering, oavsett motståndstyp. De modellerade motstånden beskrev inte tillräckligt processen och indikerade att alla tre motstånd har en samtidig och enhetlig effekt på olivinmineralisering, utöver eventuella begränsningar som föroreningar och biprodukter. Mineraliseringsexperiment med 20 μm partiklar under en timme gav 34,4% omvandling, medan 10 μm partiklar under två timmar gav 46,7% omvandling. En inledande undersökning av massöverföringsbegränsningar visade att CO2-lösningshastigheten inte är den begränsande faktorn, utan lägre omrörningshastigheter och beteendet hos (CO2 + olivin)-systemet behöver ytterligare studeras. Framtida forskning bör fokusera på att lösa dessa begränsningar. / Carbon dioxide (CO2) emissions from the energy production industry and the transportation sector globally negatively affect the environment. A prominent example is the interconnection of carbon with the greenhouse effect. Countries have agreed to mitigate their emissions and try to fulfill the target of 1.5 oC average temperature increase by 2030, but in order to do so the global emissions of CO2 from fossil fuels and industrial processes will still lead up to the astonishing amount of 40 Gtons of CO2 each year until 2100.  It is apparent that processes that try to take advantage of the emitted CO2 creating valuable products with negative emissions are highly desired. One of these is mineral carbonation, where CO2 and minerals dissolve in an alkaline solution and form stable products. Many factors affect the rate at which mineral carbonation happens. The effect of the particle size of the mineral in the process will be investigated, along the CO2 dissolution rate through the overall gas-liquid mass transfer coefficient (kLa), in order to get a better understanding of the process. Experiments were conducted with a batch reactor provided by Paebbl AB and a mathematical model was developed in Matlab. The experimental and numerical results, in regards to the particle size, were then compared for the cases of three resistances. This model can be developed further for use in a continuous mineralization process. The results revealed that increasing the particle size of olivine leads to a significant increase in the time required for total conversion, irrespective of the resistance type. The modelled resistances were found to inadequately describe the process, suggesting a simultaneous and uniform effect of all three resistances on olivine mineralization, in addition to the effect of other possible limitations such as impurities and by-products. Mineralization experiments with 20μm particles and a duration of 1 hour led to 34.4% conversion, whereas experiments with 10μm particles and a duration of 2 hours resulted in 46.7% conversion. Finally, the initial investigation of the mass transfer limitations in a system of CO2 and water led to an average kLa coefficient of 191 h-1, suggesting that the CO2 dissolution rate is not the limiting factor. However, the impact of lower stirring rates remains unexplored due to the absence of appropriate instrumentation and the behaviour of the (CO2 + olivine) system should also be studied. Future research should aim to address these limitations.