Detta examensarbete är en del av CelluFil-projektet och syftar till att optimera förhållandena för upplösning av cellulosa i vattenlösning av natriumhydroxid följd av regenering i form av ett garn. Tidigare arbeten har visa tatt cellulosa kan lösas i vattenlösning vid -10°C, men sådana förhållanden är inte tillämpliga i industriell skala. Målet med detta projekt är att arbeta vid rumstemperatur.  För detta kommer karboxylgrupper att införas i cellulosakedjorna för att öka cellulosans lighet i ett alkaliskt vattenbaserat medium. Därefter kommer cellulosan att fällas ut igen i en sur lösning. Natriumperjodat gör det möjligt att oxidera alkoholgrupperna i cellulosakedjan på C2- och C3- positionerna genom att öppna glukosenheterna för att skapa två karbonylfunktioner (aldehyde) som sedan lätt kan oxideras till karboxylgrupper med överoxidering med natriumklorit.  Den första delen av rapporten är tillägnad litteraturöversikten om ämnet med focus på natriumperjodat oxidation. Därefter föreslås ett allmänt protokoll från natriumperjodat oxidation till regenering av cellulosa till garn i en svavelsyralösning. Flera förhållanden för natriumperjodat oxidationen testas vid olika temperaturer, med eller utan metallsalter och med olika oxidationsdoser.  Upplösningsutbytet är direkt kopplat till karboxylinnehållet infört i cellulosakedjorna. Periodatoxidationen leder också till minskningen av polymerisationsgraden men cellulosas DPv förblir tillräckligt hög med det riktade COOH-innehållet och för textilapplikationer. Den möjliga produktionen av hydroxylradikaler under natriumperjodat oxidationen har undersökts med EPR/Spin-trapping. Endast försök gjorda med UV-strålning visade OH°. Således förklaras fortfarande inte depolymerisationen av cellulosa under perjodat oxidation framställd under mörka förhållanden. Eftersom, konsumtion av natriumperjodat är låg under oxidationen är dess återvinning en nyckelfråga för en industriell applikation. Det har visat sig att oxidationsfiltraten kan återanvändas flera gånger före total konsumtion av periodat. Kvaliteten på celluloser oxiderade med återvunna filtrat, särskilt deras upplösningsförmåga, bör kontrolleras. / This master thesis is part of the Cellufil Project and aims to optimize the conditions for dissolving cellulose in aqueous sodium hydroxide solution followed by regeneration it in the form of a yarn. Previous works have shown that cellulose could be dissolved in soda at -10°C, but such conditions are not applicable at industrial scale. The objective of the present project is to work at room temperature.  For that, carboxyl groups will be introduced in the cellulose chains in order to increase cellulose solubility in an alkaline aqueous medium, after this it is reprecipitated it in acidic solutions. Periodate makes it possible to oxidize the alcohol groups of cellulose on C2 and C3 positions by opening the glucose units to create two carbonyls functions (aldehyde) which can then be easily oxidized into carboxylic groups with overoxidation using sodium chlorite. A first part of the report is dedicated to the literature review on the subject, focusing on periodate oxidation. Then, a general protocol is proposed from the periodate oxidation to the regeneration of cellulose into yarn in sulfuric acid solutions. Several conditions for the periodate oxidation are tested, at different temperatures, with or without metal salts and with different oxidant dosages.  The dissolution yield is directly linked to the carboxyl content introduced in the cellulose chains. The periodate oxidation also leads to the decrease of the cellulose degree of polymerization but cellulose DPv still remains sufficiently high in the case of the targeted COOH contents and for textile applications. The possible production of hydroxyl radicals during the periodate oxidation has been investigated by EPR/Spin-trapping. Only trials made with UV radiations showed OH°. Thus, cellulose depolymerization during periodate oxidation made in dark conditions is still not explained. Because the periodate consumption is low during the oxidation, its recycling is a key issue for an industrial application. It has been shown that the oxidation filtrates could be reused several times before total oxidant consumption. The quality of celluloses oxidized with recycled filtrates, especially their dissolving ability, should be checked.

Master thesis examines comics that reflect the break-up of Yugoslavia. The theoretical part describes the main discourses that aim to explain the dissolution of Yugoslavia as well as the essential theoretical background of comics studies. The analytical part examines the ways in which comics mediate the break-up of Yugoslavia and, in particular the trauma associated with it. Authors of the comics most often work with a discourse that argues ethnic hatred, but they view it critically and point out its falsity. The analysis further revealed that comics provide a vast space for empathizing with victims of war trauma. Getting to know the survivors of traumatic events closely, as well as the concept of false memories that develop during reading of comics, facilitates empathetic reading. All the authors refuse to glorify war, focusing instead on the fatal effects that war has on the lives of ordinary people.

A green synthesis method for the synthesis of hydrotalcite has been previously developed but this process has not yet been optimised. The main focus of this dissertation was on aluminium-based LDHs. The purpose of this investigation were; to determine optimum synthesis conditions for the formation of hydrotalcite using the dissolution-precipitation method and to determine the possibility of partial substituting the divalent metal species in hydrotalcite and hydrocalumite with other metal species. During the optimisation process for the formation of hydrotalcite using the dissolution precipitation method, the formation of hydromagnesite was proved to be dominant reaction at lower reaction temperatures. With the increase in reaction time and temperature the decomposition of hydromagnesite occurred to form magnesite. At low temperatures the formation of Mg-Al-CO3 LDH is limited due to the low solubility of gibbsite. Mg-Al-CO3 LDH formation of 80 % was achieved at 140 oC after 2 hours reaction time, but crystallinity was low. To achieve an Mg-Al-CO3 LDH conversion higher than 96 % a reaction temperature of 160 oC for a minimum of 4 hours is required, but is achieved within 1 hour at 180 oC. A 99.37 % conversion was achieved at 180 oC for 5 hours with a high crystallinity and homogeneity. The surface area for Mg-Al-CO3 LDH at 180 oC after 5 hours reaction time proved to be 9.19 m2/g. The average particle size obtained for a high crystalline LDH was in the range of approx. 3 μm and 6.8 μm at temperatures of 160 oC and above for a minimum of 3 hours reaction time. The following are recommended for future work:  Determine the effect of mixing speed on the shape of the platelets.  Determine the difference between freshly precipitated metal oxides/hydroxides as reagents compared to aged metal oxides/hydroxides. The presence of Mg(OH)2 and Ca(OH)2 in solution (respectively) did increase the pH enough for the dissolution of gibbsite and most of the Mx+ metal species. A reaction time and temperature of 5 hours at 180 oC in a carbonate environment proved to be close to the ideal conditions for the formation of Mg/Mo-Al-CO3 LDH and Mg/Zn-Al-CO3 LDH. The results for the formation of Mg/Ti-Al-CO3 LDH were inconclusive. Isolation of the possible Mg/Ti-Al-CO3 LDH is recommended to determine the degree of substitution. The conditions for the dissolution of the metal species for the following experiments were proven to be successful:  Ca/Mn(lV)-Al  Ca/Mo-Al  Ca/Ni-Al  Ca/Ti-Al The following recommendations are made for the improvement on the formation of an Mx+-impregnated LDH/precursor:  Determine the effect of different reaction time and temperature.  Determine the effect of adding the carbonate source at temperatures above 100 oC under pressure.  Determine the effect of synthesising at different pH conditions. Cobalt and tin showed no/negligible amount of possible solubility. / Dissertation (MSc)--University of Pretoria, 2014. / Chemical Engineering / MSc / Unrestricted

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Sammanfattning/Abstract Olsson Nina ( 2005) Svensk-norska unionsupplösningen i läroböckerna. The Swedish - Norwegian union in textbooks. Gymnasielärarutbildningen, Historievetenskap och lärande. Lärarutbildningen, Malmö högskola. Syfte Syftet med detta arbete är att undersöka och jämföra hur den svensk- norska unionsupplösningen har behandlas i norska och svenska läroböcker i historia. Samt identifiera skillnader och likheter och försöka förklara dem. Metod Christer Karlegärds har ett antal punkter för att analysera läroböcker i historia. Det är utifrån dessa punkter jag har valt att analysera texterna om unionsupplösningen. Jag jämför läroböckerna med varandra för att se skillnader och likheter. I min analys redogör jag för rimliga hypoteser som syftar till att förklara de skillnader och likheter jag har identifierat. Resultat Undersökningen visar att det finns en hel del skillnader och likheter. Den största skillnaden är texternas omfattning. De orsaker som kan förklara skillnaderna är att unionsupplösningen har olika betydelser i de båda länderna och detta i sin tur har påverkat läroböckernas utformning. Likheterna i texterna kan förklaras med likartade kursplaner och läroboksförfattarnas vilja att framställa så neutral historia som möjligt. Nyckelord: Unionsupplösningen 1905, läroboksanalys, norska historieböcker, svenska historieböcker. / Purpose The purpose of this work is to examine and compare how the dissolution of The Swedish – Norwegian union, is handled in textbooks. The purpose is also to identify similarities and differences and attempt to explain them. Methods Christer Karlegärd has a number of points to analyze text books in history. I have based my study on these points. In my final analysis I describe reasonable hypothesis, in order to explain the similarities and differences I have found. Result In my work I found a number of similarities and differences. The biggest difference is the variation of length. The Norwegian texts are longer than the Swedish. I found that the reason to why the Norwegian texts are longer than the Swedish is because the view of the dissolution of the union is differently. And that is shown in the text books. The similarities can be explained by the writers will to describe history as neutral as possible. Keywords: The dissolution of The Swedish – Norwegian union. Textbook analysis Norwegian history books, Swedish history books.

<p> An assemblage of coral skeletons of the species Desmophyllum cristagalli were obtained from the top of Orphan Knoll, 550 km northeast of Newfoundland, from depths of approximately 1600 and 1800 m. The corals were observed for their macro- and micro-boring assemblages, and the boring morphologies documented, using binocular and scanning electron microscopy. Samples of coral were embedded with resin and etched for examination of the micro-boring assemblages.</p> <p> The largest volumetric amount of skeletal material removed was by sponges forming Entobia. This further corroborates the assumption that various species of boring sponges are distributed ubiquitously throughout a wide bathymetric range.</p> <p> Four distinct fungal forms were found, two tubular forms interpreted to be hyphal filaments and two bulbous forms interpreted to be sporangia. These forms were described on the basis of their shape, size, mode of branching, association with other structures and texture. They were then compared to other micro-boring assemblages found in previous studies from various bathymetric ranges. Some forms described in this study were found to be similar to forms described in other studies. Other forms in this study were not found to be documented. It is suggested, therefore, that certain forms, as well as low ichnodiversity, may indicate deeper water environments.</p> <p> Destructive micritization structures were also found in resin casts as well as in thin section. The extent of micritization may indicate the intensity of the parameters at the substrate that affect carbonate dissolution, such as CaCO3 and CO2 concentrations, pH, temperature, and salinity. It would therefore indicate the ambient water conditions at the substrate. If a sufficiently large database could be obtained, as well as distinct separation of the parameters responsible for carbonate dissolution, micritization may be used in a mapping of the carbonate compensation depth through time and depth ranges.</p> / Thesis / Bachelor of Science (BSc)

The increasing energy demand requires a transition from fossil fuels to renewable resources. Lithium-ion batteries (LIBs) offer a promising solution as efficient energy storage devices. However, the aluminum current collector (CC) in LIBs is susceptible to anodic dissolution above 3 V vs. Li+/Li in commercial carbonate liquid electrolytes, compromising the battery performance. In this study, various approaches were explored to mitigate anodic dissolution in LiFSI EC:DEC at high voltages of the aluminum CC in LIBs, employing cyclic voltammetry (CV) and scanning electron microscopy (SEM). It was found that boiling the Al foil in water in an air atmosphere to increase the thickness of the surface Al2O3 layer improved the anodic stability and offered enhanced protection against proton attack (due to the oxidation of the carbonate solvent at high voltage). However, increasing the LiFSI electrolyte concentration to 2 M did not increase the anodic stability due to the absence of a passivating AlF3 layer. Notably, in 4 M LiFSI, impurity-induced high F- concentration facilitated the formation of a passivating AlF3 layer, resulting in improved anodic stability. Moreover, specific volume ratios of LiFSI EC:DEC and 1 M LiPF6 EC:DEC (1:1) (LP40) yielded the F- concentration necessary for forming a passivating AlF3 layer and significantly enhanced the anodic stability. On the other hand, carbon-coating the Al foil did not show significant improvements regarding the anodic stability. It was found that the corrosion was time-dependent at a low scan rate, a drastic anodic dissolution of the aluminum was seen at higher temperatures, and the corrosion also became more pronounced. At room temperature, carbon-coated Al foils exhibited increased stability.