<p> In this study the experiments were designed to measure the geochemical and surface charge (zeta potential) changes with time for two crushed samples of feldspar (Na-fs and K-fs) over the pH range of most natural waters (5 to 9). These experiments show: </p> <p> (a) the importance of adsorption/desorption phenomena in both short-term and long-term feldspar dissolution, and probably for chemical weathering in general; </p> <p> (b) that the generalized curve which characterizes the geochemical data (an initial rapid rise to a peak followed by a decrease to a lower, either constant or later increasing value) is consistent with a consideration of the adsorption/desorption process (i.e., the formation of the double layer) taking place at the feldspar surface and with the simple dissolution of the mineral; </p> <p> (c) that the cation-silica ratios (Na₂O/SiO₂, K₂O/SiO₂, CaO/SiO₂) of the solution compared to those in the original feldspar indicate an initially incongruent dissolution which tends towards congruency during the latter part of the experiments. </p> <p> From information in the Iiterature and the results of these experiments. it may be concluded that: </p> <p> (a) the most important or master variables in chemical weathering are abrasion, minerologic or crystallographic factors such as twinning, exsolution regions, impurities, fractures and grain size, and solution composition and concentration. pH does not appear to be a master variable in most natural waters, especially for long-term weathering, and the chemical composition of the mineral phase is also not a good criterion for predicting weathering behaviour; and </p> <p> (b) the most extreme chemical weathering should occur in a high energy environment, either for physical reasons (i.e., high abrasion due to extreme relief) or for chemical reasons (i.e., high rainfall). </p> / Thesis / Master of Science (MSc)

<p> This thesis establishes the general Principle of Complementary Potential Energy for the finite deformations of an elastic continuum, in which the Lagrange stress tensor is employed as the stress variable. It is demonstrated that constitutive relations, formulated in terms of the Lagrange stress tensor and the deformation gradient, will admit inversion. Consequently, the present theorem and the theorem proposed by LEVINSON are established as valid principles. The complementary strain energy density of the present theorem, however, is shown to be Independent of rigid displacements, in contrast to that of the LEVINSON formulation. The general Principle is reduced to the form appropriate to finite elastic systems, and it is established that the present theorem reduces to, and therefore contains as a special case, the LIBOVE Theorem.</p> / Thesis / Doctor of Philosophy (PhD)

The importance of Hydrogen (H2) in current global energy systems is undeniable. Moving from the energy systems depending on fossil fuel to energy systems that are carbon-free is a necessity, thus solutions such as hydrogen economy is required. Especially after recent geopolitical challenges in Europe which could make the energy acquisition a crucial problem. Liquid organic hydrogen carriers (LOHC) are applicable pathways for transitioning H2 into energy and to avoid the storage and transportation limitations of gaseous and liquid H2. Formic acid (FA) is an attractive alternative for such purposes due to its minimal level of toxicity and its significant volumetric storage capacity for H2. In this study, a Life cycle assessment (LCA) of the supply chain involving the Trans-Atlantic export of energy from Canada to Germany is conducted using formic acid as a LOHC and OxFA process to convert biomass to formic acid. The environmental impacts of all units and processes involved in this supply chain are examined, and the results are compared against other traditional systems for hydrogen production. A sensitivity analysis was also performed to recognize the crucial contributors and assess the processes and units that impose considerable influence on the overall environmental impact. / Thesis / Master of Applied Science (MASc) / Hydrogen (H2) plays a crucial role in transitioning from fossil fuel-based to carbon-free energy systems, a shift highlighted by recent geopolitical challenges in Europe. Liquid organic hydrogen carriers (LOHC) offer a solution for hydrogen storage and transport issues associated with its gaseous and liquid states. Formic acid (FA) is particularly promising as a LOHC due to its low toxicity and high hydrogen storage capacity. This study conducts a Life Cycle Assessment (LCA) of a supply chain that uses formic acid to export energy from Canada to Germany, involving the OxFA process for converting biomass to formic acid. The environmental impacts of all processes in this supply chain are evaluated and compared with traditional hydrogen production methods. Additionally, a sensitivity analysis identifies key contributors and assesses their impact on the overall environmental footprint.

Denna studies syfte är att undersöka hur döden och livet efter döden skildras i ett antal barnböcker för att kunna föra en didaktisk diskussion om böckernas didaktiska potential för arbete med värdegrundsfrågor kopplat till ämnet döden. Böckerna som undersöks är Allrakäraste Syster, Mio, min Mio, Sunnanäng och Bröderna Lejonhjärta skrivna av Astrid Lindgren.  Tidigare forskning inom området visar att skönlitteratur kan vara ett fruktbart verktyg för att behandla svåra ämnen som döden, och att skönlitteraturens didaktiska potential delvis beror på textens faktiska innehåll men även på vad man gör med texten. Forskningen visar också att det är av stor vikt att ta upp ämnet döden med barn eftersom de, likt vuxna, också tänker, tycker och känner kring detta ämne.   Undersökningen av böckerna gjordes genom en tematisk analys utifrån den teoretiska utgångspunkten närläsning, och resultatet av denna analys diskuteras didaktiskt utifrån de teoretiska utgångspunkterna erfarenhetspedagogik och didaktisk potential. Den tematiska analysen genererade sex olika teman som visar vilka olika aspekter av döden och livet efter döden som skildras i böckerna. Det är dessa teman, och de koder och textstycken som de är uppbyggda av, som ligger till grund för besvarandet av studiens två första frågeställningar. Den tredje frågeställningen besvaras i den didaktiska diskussionen.  En slutsats som kan dras av den genomförda analysen och didaktiska diskussionen är att en varierad bild av döden och livet efter döden skildras i böckerna. Dessa skildringar kan anses ge upphov till en didaktisk potential, men att denna didaktiska potential först realiseras genom ett väl genomtänkt arbete med böckerna.

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