This work reports the study of semiconductor nanocrystals, also known as quantum dots, focusing specifically on zinc sulfide (ZnS). Two different capping agents were used (glutathione and N-acetyl-L-cysteine) for the preparation of ZnS nanocrystals via aqueous route. The study aimed specifically at evaluating the efficacy of the capping agents in the stabilization of semiconductor nanocrystal suspensions towards coalescence as well as in controlling nanocrystal size and optical properties. In addition the effect of doping the ZnS nanocrystals with transition metal ions (Cu2+ and Co2+) on the photoluminescence properties has also been studied. Finally the possibility of energy transfer between the semiconductor nanocrystals and the safranine dye was also evaluated. Spherical-shaped glutathione and N-acetyl-L-cysteine-capped ZnS nanocrystal were obtained with diameters below 5 nm free from coalescence, showing that both iv capping agents were efficient as stabilizers. Both capping agents lead to the formation of ZnS nancrystals with blue fluorescence, typical of the involvement of surface defect states of ZnS. However, samples prepared with glutathione exhibited higher fluorescence intensities than those obtained with N-acetyl-L-cysteine. Upon doping glutathione-capped ZnS nanocrystals with both copper and cobalt the fluorescence intensities decreased gradually following the increase in nominal concentration of dopants, suggesting that cobalt ions played a similar role as copper. Considering both the effect on the intensities and the absence of d-d metal transitions this study suggests that doping reduced the concentration of cation vacancies as well as the involvement of at least one cobalt state in the transition processes. Changes in emission wavelength with different dopant concentrations were not observed probably owing to lack of influence on the nanocrystal size. Finally the preliminary study of fluorescence quenching of semiconductor nanocrystals by safranine dye indicated that significantly low concentrations were able to quench the emissions. Different components of the emission band were distinctly affected. Data analysis by Stern-Volmer plots suggested the occurrence of more than one transfer processes (energy and/or electron transfer). This study will be refined in future works. / No presente trabalho foram estudados nanocristais semicondutores, tambem conhecidos como pontos quanticos ou quantum dots, selecionando-se especificamente o sulfeto de zinco (ZnS). Foram utilizados ois diferentes agentes estabilizantes (glutationa e N-acetil-L-cisteina) na obtencao de nanocristais de ZnS por via aquosa. Buscou-se avaliar, especificamente, a eficiencia dos agentes tiois na estabilizacao das suspensoes de nanocristais frente a agregacao, no controle e distribuicao de tamanhos das particulas, bem como nas propriedades opticas. Estudou-se, alem disto, o efeito da dopagem com ions de metais de transicao (Cu2+ e Co2+) nas propriedades de fluorescencia. Por fim, foi avaliada a possibilidade de transferencia de energia entre os nanocristais semicondutores dopados e o corante safranina. Os nanocristais semicondutores de ZnS estabilizados por glutationa e por N-acetil-L-cisteina foram obtidos com tamanhos abaixo de 5 nm, formas aproximadamente esfericas e livres de agregacao, evidenciando que ambos agentes ii estabilizantes foram eficientes. Ambos agentes estabilizantes levaram a formacao de nanocristais com emissoes na regiao do azul, caracteristicas do envolvimento de estados de defeito de superficie do ZnS. No entanto, as amostras preparadas com glutationa apresentaram maiores intensidades de fluorescencia, quando comparadas com aquelas preparadas com N-acetil-L-cisteina. A dopagem dos nanocristais semicondutores ZnS/Glu com ions cobre e cobalto teve um efeito de diminuir as intensidades de fluorescencia dependente da concentracao nominal dos dopantes em ambos os casos, sugerindo que o cobalto atua de modo analogo ao cobre. Considerando-se tanto o efeito sobre as intensidades de emissao do ZnS quanto a ausencia de transicoes d-d do metal, o estudo sugeriu que a dopagem reduz a concentracao de vacancias de cations, bem como o envolvimento de pelo menos um dos estados eletronicos do cobalto nos processos de transicao. Nao se observou variacoes nos comprimentos de onda para diferentes concentracoes dos dopantes, provavelmente pela ausencia de interferencia no tamanho dos nanocristais semicondutores formados. Por fim, o estudo preliminar da supressao de fluorescencia dos nanocristais semicondutores pelo efeito de diferentes concentracoes do corante safranina mostrou que concentracoes significativamente baixas do corante foram suficientes para diminuir a intensidade de fluorescencia. Diferentes componentes das bandas de emissao dos nanocristais semicondutores foram influenciados de modo distinto. A analise dos dados pelos graficos de Stern-Volmer sugeriu a ocorrencia de mais de um processo de transferencia (energia e/ou eletrons). Este estudo sera aprofundado nos trabalhos futuros.

Des détériorations importantes sont observées dans les réseaux d’assainissement en béton en raison de la présence d’hydrogène sulfuré (H2S). Différentes études ont montré qu’un environnement riche en hydrogène sulfuré entraîne, au contact de surfaces cimentaires, la sélection de bactéries sulfo-oxydantes (bactéries capables d’oxyder des composés soufrés réduits), menant à la production d’acide sulfurique. Cet acide détériore localement les réseaux par dissolution et recomposition minéralogique de la matrice cimentaire (formation de gypse et d’ettringite). Les réseaux ne collectent alors plus correctement les eaux usées et ce phénomène provoque donc des travaux de rénovation onéreux. Dans ce contexte, des solutions plus performantes que celles mises en place actuellement doivent être étudiées. L’objectif du projet FUI DURANET dans lequel s’inscrit cette thèse vise à proposer un essai accéléré et à développer un modèle.La mise en place d’essais abiotiques a permis de démontrer que cette première étape n’est pas l’étape limitante du phénomène de biodétérioration. En effet, le pH de surface des matériaux cimentaires adapté au développement microbien est rapidement atteint lorsqu’ils sont mis au contact de l’hydrogène sulfuré à une concentration élevée (100 ppm), quel que soit le matériau cimentaire considéré (mortiers à base de ciments CEM I, CEM III, CEM IV, CEM V, CAC et CSS). La modélisation de l’attaque par l’acide sulfurique et la mise en place d’un essai représentatif et accéléré ont ensuite été abordées pour prédire la durabilité des différents matériaux cimentaires de l’étude. Pour l’essai, différentes techniques d’ensemencement des microorganismes à la surface des matériaux cimentaires ont été comparées, afin de déterminer laquelle mène à la meilleure reproduction des conditions d’un réseau d’assainissement et à l’accélération des mécanismes de biodétérioration la plus importante. Ces essais permettent de préconiser l’utilisation de boues activées contenant un consortium de microorganismes, par rapport à l’utilisation de souches de collection, dont l’activité dépend trop fortement de leur adaptabilité aux conditions environnementales. L’ensemble des résultats, obtenus expérimentalement et par modélisation, montre une meilleure résistance des ciments d’aluminate de calcium et une dégradation très importante des ciments Portland face aux mécanismes mis en jeu, en accord avec les essais in-situ / Important deteriorations have been observed in concrete sewers, due to hydrogen sulfide (H2S) presence. H2S is used as nutrients for sulfur-oxidizing bacteria (bacteria able to oxidize the reduced sulfur compounds) and is oxidized into sulfuric acid. This acid attack of concrete leads to cementitious matrix dissolution and expansive products formation (gypsum and ettringite). This phenomenon disturbs the sewer system and conducts to expensive works of rehabilitation. In order to avoid this degradation, a French project named “FUI Duranet” was initiated to propose more efficient solutions. The aim of this thesis is to define a representative and accelerated test as well as a predictive model.Abiotic tests allow stating that this first stage of the biodeterioration mechanisms is not the limiting stage. Indeed, the adapted surface pH of the cementitious materials to bacteria development is quickly reached with a high H2S concentration (100 ppm), whatever the cementitious materials considered (mortars based on CEM I, CEM III, CEM IV, CEM V, CAC, and SSC cements). The chemical-transport modeling of the sulfuric acid attack of cementitious materials and the establishment of a representative and accelerated test have been proposed to predict their service life in these conditions. For the test, different seeding technics have been compared in order to determine which one lead to the better reproduction and acceleration of biodeterioration mechanisms. This test allows recommending the sludge use, which contains a microorganism’s consortium, rather than a collection strain use, whose activity is too dependent on environmental conditions. With the experimental test and the model, the better resistance of the calcium aluminate cement and the important degradation of the Portland cements are quickly confirmed, as highlighted during the field tests

A local integrated pulp and paper Kraft mill had come under pressure from the local communities and mill personnel to reduce the odours that were perceived to be generated at the Farm Dams and irrigation farm situated adjacent to the mill. The typical odours associated with Kraft mills are due to the generation of four reduced sulphur compounds such as hydrogen sulphide (H2S), methyl-mercaptan (CH3SH), dimethyl-sulphide (CH3)2S and dimethyl-disulphide (CH3)2S2. These compounds are collectively referred to as Total Reduced Sulphur (TRS) components which are generated as a direct result of the Kraft pulping and chemical recovery process. These components can either be in the gaseous or aqueous phase depending on the characteristics of the effluent. Gaseous and aqueous TRS profiling of the mill indicated that hydrogen sulphide (H2S) was the main odour component generated and emitted from the Clarifiers and the Treated Effluent Transfer Sump (TETS) at the effluent treatment plant. The hydrogen sulphide (H2S) emission levels were affected by process upsets, sludge removal frequencies, chemical composition of the effluent, Sulphate Reducing Bacteria (SRB) activity, pH and temperature fluctuations. Treatment options such as pH control using slaked lime, dosing of biocides, addition of biomodifiers and/or a sulphate reduction inhibitor were investigated. The use of slaked lime, Ca(OH) 2, for pH control was not practical due to continuous pH fluctuations, increasing the pH would increase the scaling tendencies of the effluent and would also affect the soil cation-anion exchange properties of the irrigated farm land. The use of non-oxidising biocides was effective in reducing SRB activity between 99.2% and 99.8% at dosages between 4 mg/l and 25 mg/l. However, the use of biocides was not considered as a long term treatment option due to the various disadvantages such as the stability of the biocides at fluctuating pH and temperatures, half-life, environmental accumulation, toxicity and costs. The aqueous H2S level was reduced by 79% using different combinations of biomodifiers (nitrates, nitrites, molybdenum). Increasing the dosages of the biomodifiers (> 500mg/l) would be required to increase the reduction of H2S levels by more than 79%. The increased dosages would significantly increase the cost of the treatment programme. The accumulation of nitrates, nitrites and molybdenum could affect the soil texture, cation-anion exchange capacity, permeability, Sodium Absorption Ratio (SAR) and nutrient availability. A more environmentally friendly and cost effective treatment was found using sodium nitrate (biomodifier) together with AQ (sulphate reduction inhibitor). The continuous dosing of 50 mg/l sodium nitrate together with 4 mg/l AQ would be effective in reducing the average aqueous H2S levels (40 mg/l) by at least 92%. This treatment would also be compatible with aeration or oxidation procedures to further increase the removal of H2S to achieve an aqueous H2S level of <1 mg/l. Aeration or oxidation would also increase the dissolved oxygen and COD levels, increase the inhibition of SRB activity and oxidise any reduced sulphur. The dosing of sodium nitrate and AQ to control the generation of H2S is not patented in South Africa. It can, therefore, be used to treat the Kraft mill effluent without violating any intellectual property rights in South Africa. / Dissertation (MSc(Applied Science))--University of Pretoria, 2008. / Chemical Engineering / unrestricted

Ce travail de doctorat concerne le stockage des déchets radioactifs à vie longue et haute activité en site géologique profond. Dans le concept actuellement retenu par l’Andra (Agence nationale pour la gestion des déchets radioactifs), c’est une enveloppe en acier non allié, appelée « surconteneur », qui sera au contact de l’environnement. Dans les conditions anoxiques où se retrouvera l’acier après une période initiale relativement courte, des vitesses de corrosion très faibles sont attendues, ce qui garantirait l’intégrité du surconteneur pour des millénaires. Cependant, il n’est pas exclu que des bactéries sulfurogènes puissent se développer à proximité ou au contact du surconteneur et modifier localement la cinétique de la corrosion via les espèces sulfures produites par leur métabolisme. L’objectif de cette thèse consistait à améliorer notre compréhension du système de corrosion constitué de l’acier, de sa couche de rouille essentiellement composée de sidérite FeCO3 et d’un électrolyte sulfuré.Pour ce faire, il a été nécessaire dans un premier temps de caractériser par microspectroscopie Raman les sulfures de fer impliqués dans les processus de corrosion et d’étudier les mécanismes de leur formation et de leur transformation dans différentes conditions de concentration en Fe(II) et S(-II), de pH, de température et d’oxygénation. Il a pu être démontré que le spectre Raman de la mackinawite FeS, composé qui précipite à partir de Fe(II) et S(-II) dissous dans toutes les conditions considérées ici, évoluait avec la cristallinité et l’oxydation du composé. Par ailleurs, les mécanismes de l’oxydation à 80°C en milieu acide anoxique de la mackinawite en greigite Fe3S4 ont pu être décrits. Cette étude a permis de démontrer que les sulfures de fer souvent présents sur les objets archéologiques ferreuxissus de milieux anoxiques sont soit de la mackinawite, soit étroitement apparentés à la mackinawite.Dans un deuxième temps, nous avons étudié la formation de produits de corrosion carbonatés par polarisation anodique d’électrodes d’acier à température ambiante dans des électrolytes désaérés à base de NaHCO3. Les conditions expérimentales permettant d’obtenir la sidérite ont été re précisées et utilisées pour synthétiser des couches modèles de FeCO3 sur acier. Par ailleurs, il a été observé que la rouille verte carbonatée était le principal produit se formant aux faibles concentrations en espèces carbonates (0,003 et 0,1 mol L-1 par exemple),la sidérite se formant aux fortes concentrations (0,5 et 1 mol L-1). Les conditions permettant la formation de la chukanovite, l’hydroxycarbonate de Fe(II) de formule Fe2(OH)2CO3, n’ont pas pu être explicitées, même si cette phase a été obtenue dans un électrolyte contenant à la fois des ions SO42- et HCO3- à la concentration de 0,03 mol L-1.Enfin, les interactions entre sulfures et produits de corrosion ont été étudiées. La sidérite, la lépidocrocite et la goethite sont toutes réactives vis-à-vis des sulfures. Ainsi, il apparaît clairement que les espèces sulfures produites par les BSR devraient interagir avec la couche de produits de corrosion avant d’interagir avec le métal sous-jacent. Les tests effectués sur des analogues archéologiques du 16ème siècle, immergés deux mois dans des solutions sulfurées en conditions anoxiques ont permis de le démontrer. Le principal effet de cette immersion a été la formation de sulfures de fer à l’interface entre la couche dense de produits de corrosion, essentiellement constituée de sidérite, et le milieu transformé, zone où s’entremêlent les minéraux propres au sol et ceux produits par la corrosion du fer. Les espèces sulfures n’ont pas été détectées au voisinage immédiat de la surface du métal. / This PhD work deals with the nuclear waste disposal. In France, it is envisaged byAndra (French national radioactive waste management agency) that high-level radioactivewastes will be confined in a glass matrix, stored in a stainless steel canister, it self placed in a carbon steel overpack. The wastes will then be stored at a depth of ~500 m in a deep geological repositery, drilled in a very stiff (indurated) clay (argillite) formation. The kineticsof corrosion expected for the overpack in this disposal concept are low and will stay low if the somehow protective rust layer that will develop initially on the steel surface remains undamaged. Local changes of the physico-chemical conditions may however degrade this layer and induce accelerated kinetics of corrosion. In particular, the growth of sulphate reducing bacteria (SRB) close to the steel overpack cannot be excluded and the sulphid especies these micro-organisms produce may modify the corrosion process. The aim of this work was then to achieve a better understanding of the corrosion system constituted with steel, its rust layer mainly made of siderite FeCO3, and a sulphide-containing electrolyte.First, it proved necessary to characterise the iron sulphides involved in the corrosion processes by Raman micro-spectroscopy so as to study their formation and transformation mechanisms in various conditions of Fe(II) and S(-II) concentration, pH, temperature andaeration. It could be demonstrated that the Raman spectrum of mackinawite FeS, thecompound that precipitated in any case from dissolved Fe(II) and S(-II) species with the experimental conditions considered here, depended on the crystallinity and oxidation state.Moreover, the mechanisms of the oxidation of mackinawite into greigite Fe3S4 in acidicanoxic solutions at 80°C could be described. Finally, iron sulphides, often present on archaeological artefacts, could be identified using Raman micro-spectroscopy. The compounds present were mainly mackinawite and greigite.Secondly, to investigate the nature and properties of carbonated rust layers, carbonsteel electrodes were polarised anodically in NaHCO3 electrolytes continuously de-aerated byan argon flow. The experiments were performed at room temperature. The carbonated greenrust was observed to form at 0.003 and 0.1 mol L-1 NaHCO3 whereas FeCO3 was obtained atthe largest concentrations (0.5 and 1 mol L-1). Additional experiments were performed similarly in solutions of NaHCO3 and Na2SO4. Chukanovite, the Fe(II) hydroxycarbonate with formula Fe2(OH)2CO3, could be obtained in solutions containing 0.03 mol L-1 of eachsalt.Finally, interactions between sulphide species and corrosion products were studied.Siderite, goethite and lepidocrocite proved to be reactive towards sulphide. So, it seems clear that sulphide species produced by SRB should interact with the rust layer before to reach the metal underneath. Tests were performed with ferrous archaeological artefacts immersed 2months in anoxic sulphide-containing electrolytes to demonstrate it. The main effect of theimmersion was the formation of iron sulphide at the interface between the dense corrosion products layer, mainly constitute of siderite, and the transformed medium, where minerals ofthe soil are mixed with corrosion products. Sulphide species were not detected at the vicinityof the iron surface.

This thesis presents an investigation into the factors affecting the morphology of hybrid inorganic/organic photoactive layers used in photovoltaic cells. Although optimisation of the organic (polymer) phase has received substantial attention, research into the morphology of the inorganic phase (semiconducting nanocrystals) remains limited. It is believed that there is a strong link between the morphology of the final photoactive film and the quality of the initial nanocrystal dispersion. To this end, two nanocrystal systems were investigated; zinc oxide (ZnO) and lead sulphide (PbS). ZnO nanocrystals were synthesised and found to possess reproducible characteristics. It was determined that colloid stability was initially dependent upon the presence of acetate groups bound to the surface, which in turn required a small quantity of methanol to be present in the organic dispersant. It was also discovered that while methanol evaporated readily from the surface of the nanocrystals, another molecule, 1-propylamine (1-PA), did not. Further investigations showed that while methanol only weakly physisorbed to the surface of ZnO nanocrystals, 1-PA formed strong, dative covalent bonds with Zn2+, preventing evaporation despite a low boiling point. Subsequent investigations into the effects of different ligands upon colloid stability found that amine-based groups typically possessed superior stabilising capabilities compared to alcohol-based analogues. The characteristics of nanocrystal / polymer blends were also investigated. It was determined that the nanocrystal dispersion became unstable at higher concentrations of polymer due to depletion aggregation. Films of nanocrystal / polymer blends were cast from dispersions containing either alcohol or amine-based ligands, and it was observed that dispersions stabilised with 1-PA possessed smooth morphologies on the micrometer scale. Investigations at the nanometer scale, however, revealed aggregates large enough to favour recombination.The latter half of this thesis regards the characterisation of PbS nanocrystals and investigations into triggered aggregation. It was determined that while PbS nanocrystals possessed reproducible characteristics, the stabilising molecule, oleic acid (OA) was insulating. The effects of exchanging the OA groups for a shorter ligand, butylamine (BA) were investigated.Finally, PbS nanocrystals were treated with a bidentate ligand, 1,2-ethanedithiol (EDT) to induce triggered aggregation. It was observed that the system was highly sensitive to the concentration of EDT in dispersion, forming small, relatively dispersed aggregates at low [EDT], and micrometer-sized crystalline structures at high [EDT]. The characterisation and entrapment of these nanocrystal structures within semi-conducting polymer films is also discussed.

Caesalpinia pyramidalis, is an endemic plant from the North east of Brazil which present scientifically proven anti-inflamatory, antinociceptive, and gastroprotective activities. This work aimed at evaluating the gastroprotective effect of the extract of Caesalpinia pyramidalis (EECp) bark in acute gastric ulcers induced by ethanol in Wistar rats. The ulcered animals were treated with a dose of 100mg/kg of EECp and L-NAME (nitric acid blocker) and Propargylglycine (hydrogen sulfide blocker). It was evaluated, in all treatments, the role of the gas mediators such as nitric oxide (NO) and hydrogen sulfide (H2S) and also the participation of mast cells and molecules involved in the anti-inflamatory process as iNOS and citocin IL-4. It was observed in the NO evaluation that the treatment with L-NAME was not able to revert the inhibitory effect of EECp on the ulcers induced by ethanol, showing that the EECp does not operate via NO. However, the H2S can operate in the gastro protection of the EECp as its block hindered the gastroprotective effect on the ulcers induced by ethanol. In order to evaluate the mast cells, histological cuts were made with toluidine blue/alcian blue/safranine where different mast cells phenotypes were observed. In all treatments a prevalence of mucous mast cells was observed. The techniques of immunofluorescence and flow cytometry were used to evaluate IL-4 and iNOS. The ulcered animals treated with EECp presented high expression of IL-4 and low expression of iNOS, suggesting an anti-inflammatory activity of EECp. In conclusion, the gastroprotective effect of EECp and its action mechanism are related to H2S in diminishing the oxidative stress, the induced NO synthase, and the positive immunomodulatory effect for IL-4, with the diminution of mucous mast cells during the inflammatory process. / A Caesalpinia pyramidalis, planta endêmica da região do Nordeste é utilizada popularmente para tratamento de diversos distúrbios patológicos e possui ação anti-inflamatória, anti-nociceptiva e gastroprotetora. O objetivo desse trabalho foi avaliar o efeito gastroprotetor do extrato da entrecasca da Caesalpinia pyramidalis (EECp) em modelos de úlcera aguda induzidas por etanol em ratos Wistar. Os animais ulcerados foram tratados com EECp na dose de 100 mg/kg, com L-NAME (bloqueador de óxido nítrico) e Propargilglicina (bloqueador de sulfeto de hidrogênio). Para todos os tratamentos foi avaliado o papel de mediadores gasosos como óxido nítrico (NO) e sulfeto de hidrogênio H2S, e também a participação de mastócitos e de moléculas envolvidas no processo inflamatório como a iNOS e a citocina IL-4. Na avaliação dos de NO observamos que o tratamento com L-NAME não foi capaz de reverter o efeito inibitório da EECp sobre as úlceras induzidas por etanol, demonstrando que o EECp não age pela via do NO. Contudo o H2S pode estar atuando na gastroproteção do EECp pois o seu bloqueio impediu o efeito gastroprotetor sobre as úlceras induzidas por etanol. Para avaliação de mastócitos cortes histológicos foram corados com azul de toluidina/ alcian blue/ safranina onde observamos diferentes fenótipos de mastócitos. Observamos um predomínio de mastócitos mucosos em todos os tratamentos. Para a avaliação de IL-4 e de iNOS foram utilizadas as técnicas de imunofluorescência e citometria de fluxo. Observamos que os animais ulcerados tratados com EECp apresentaram alta expressão de IL-4 e baixa expressão de iNOS, sugerindo uma atividade anti-inflamatória da EECp. Pode-se concluir que o efeito gastroprotetor do EECp e o possível mecanismo de ação, está relacionado ao H2S na diminuição do estresse oxidativo, diminuição do NO sintase induzível e com o efeito imunomodulatório positivo para IL-4, como a diminuição de mastócitos mucosos durante o processo inflamatório.

Věra Mansfeldová: Time-resolved potentiometry on liquid-liquid interface (Dissertation thesis) Abstract The aim of this work is to explore the method of temporal resolution in potentiometry as a new prospective electrochemical analytical technique. In connection with interface of two immiscible electrolyte solutions (ITIES) it may find utilization in analytical chemistry. This technique up to my knowledge has not been published yet. Potential response of analyte on liquid/liquid interface includes both distribution processes, their temporal resolution and redox processes, which specificity can modified by changing the composition of individual phases. Unlike "classic" potentiometric techniques, limited just to potential determination, this method, which I have given the working name "time resolved potentiometry at liquid-liquid interface" utilizes time development of potential response, which was found to be an analyte-specific function. The time resolved potentiometry presented in this work includes time course of potential response to analytical parameters specific for particular analyte. It brings series of data characterizing the analyte in given environment in a similar manner as spectra and may allow creating analyte-specific data package - fingerprint. Combination with ITIES allows, unlike...

I detta examensarbete har en geoteknisk utredning utförts för att bedöma ifall grundläggning aven bro över Fyrisån i Uppsala kan utföras på enklaste sätt, genom plattgrundläggning. Arbetethar grundats på att undersöka hur grundläggningen styrs av den postglaciala lerans tekniskaegenskaper. Problemformuleringen har varit, att undersöka hur den geotekniska projekteringenav bron, dels skulle kunna genomföras, dels ska genomföras utifrån beaktande och värderingav tekniska och i viss mån ekonomiska aspekter. De frågeställningar som behandlas är: Vilkautmaningar finns det med att bygga bron på den aktuella platsen? Vilka svårigheter finns detmed att bygga bron enligt enklaste sätt, Vilka ytterligare grundläggningsmetoder kan användasför att grundlägga bron samt hur ska dessa tillämpas? Arbetet har utförts med en inledandelitteraturstudie via Malmö Universitetsbibliotek, sökmotorn Libsearch och SGI:s bibliotek. Enfallstudie har utförts av jordlagerförhållandena vid Fyrisån, där utvärderingen baseras påanalyser av data från tillgängliga fältundersökningar i området. Handberäkningar hargenomförts för att överslagsmässigt kontrollera de geotekniska förutsättningarna i brott- ochbruksgränstillståndet. Handberäkningarna har jämförts med datorberäkningar från Plaxis 2D.Teorin som ligger till grund för beräkningarna baseras på etablerade standarder somkontrolleras mot flertalet källor. Undersökningarna visar att djupet till berg är ca 55 m underbefintlig markyta. Jordlagerföljden består generellt av fyllning på siltig torrskorpelera påsulfidlera på lera/silt på friktionsjord. Utmaningen med grundläggningen av bron kansammanfattas till den potentiellt miljöfarliga sulfidhaltiga leran som leder till svårigheter ibruksgränstillståndet, eftersom den har en benägenhet att ge stora sättningar vid belastning,kombinerat med det stora djupet till berg.Handberäkningar visar att bron inte kan grundläggas på platta på mark eftersom jorden går ibrott när den belastas av fundamentet för odränerade förhållanden, dvs. korttidstillståndet. Ävenberäkningar med Plaxis 2D indikerar att jorden går i brott. Handberäkningar ochplaxisberäkningar har också genomförts för att undersöka de sättningar som kan utbildas vidgrundläggning på platta på mark. Det tillåtna värdet för sättningar är 0,050 m medanhandberäkningarna ger en sättning på 0,52 m och Plaxis 2D 0,41 m. För att bron ska kunnagrundläggas på den postglaciala leran används istället pålar med en geoteknisk bärförmåga på725 kN. Pålarnas knäcklast har beräknats till 5254 kN. Totalt krävs 18 pålar för att grundläggabrofundamentet. Pålning används då det råder osäkerhet hur användningen av övrigagrundläggningsmetoder interagerar med sulfidhaltig lera, bland annat hur reaktionen mellankalk/cement och sulfidjorden fungerar, om t ex kalk-cement-pelare skulle ha använts istället förpålar, samt resultaten av en eventuell försurning av omkringliggande miljö. Sulfidhaltig lerasänker pH-värdet i jord vid exponering för syre.Handberäkningarna och datorberäkningarna visar liknande resultat, vilket tyder på att deterhållna resultatet är rimligt. Förutsättningarna som används för beräkningarna är baserade påempiriska samband, som vid jämförelse med resultat från genomförda sonderingar visar på engod överensstämmelse. Avvikelser i sonderingarna bedöms vara ett resultat bl. a av deskalrester som finns i jorden, vilket beaktas vid värdering av resultatet. Resultatet från denutförda studien visar, att grundläggning av platta på mark inte är möjlig, främst på grund av destora sättningar som kan förväntas utbildas. Grundläggning med pålning väljs utifrånmiljömässiga och tekniska krav. / In this thesis, a geotechnical investigation has been performed to assess if the foundation of abridge over Fyrisån, Uppsala, can be founded by plate foundation. The work has been based oninvestigating how the postglacial clay affects the construction based on the current groundconditions. Questions being answered are: what challenges there are in building the bridge atthe current location, what difficulties there are in building the bridge according to conventionalmethods and what foundation methods can be used to construct the bridge and how these shouldbe applied. The work has been carried out through a literature study. A case study has beenperformed of the soil conditions in Fyrisån which shows that the soil consists in general offilling on silty dry clay crust on sulfide clay on clay/silt on friction soil. The depth to rock is 55meters.The main challenge with this specific soil are the large compression, which is a result of largedepth and the fact that the soil consists of sulfide clay. The calculations by hand correspond thecalculation done in Plaxis 2D where the results show that the soil breaks in the undrained stateand the compression is 0,41m, 0,52 m by hand, compared to the maximum requirement of 50mm. The choice of foundation is piling due to the uncertainty of reaction betweenlimestone/cement and sulfide and the risk of acidification.The condition on which the calculations are based on is compared to completed probes whichshows a good correspondence. Any abnormalities are concluded to be a result of the soil’scontent of residual of shell. In conclusion the study shows that the foundation cannot be donewith a plate foundation and the soil has to be reinforced due to the large compression of thesoil.

Paper and pulp industry and steel industry are two major industries in Sweden, both of which are facing big challenges to treat their waste products properly. In this thesis work, initial evaluation of mechanical properties of briquettes made of waste products was performed. Three different CaO-containing waste products (Mesa, Kalk, Fly Ash) from Stora Enso and SCA were pressed with one kind of binding material (AOD slag) from Outokumpu. Drop tests were carried out to test the impact strength of the lab-made briquettes. Three different parameters were investigated of their influence on the impact strength of the briquettes: 1) Composition of briquettes 2) Heat treatment procedure 3) Exposure time to open air. A total of 97 briquettes were pressed. Drop test results show that for different material based briquettes, heat-treatment and exposure to open air had different influence on the final impact strength. In order to get best impact strength, MB briquettes (90% Mesa +10% AOD slag) heat treated at 850℃, KB briquettes (90% Kalk +10% AOD slag) heat treated at 850℃ and FC briquettes (80% Fly Ash + 20% AOD slag) exposed to open air for 20 days are recommended. Melting experiment was carried out to investigate the sulphur removal ability of the briquettes in metallurgical processes. Thermodynamic calculation of sulphide capacity was done. / Pappers-, massa och stålindustrin är två stora industrier i Sverige, vilka båda står inför stora utmaningar för att hantera sina avfallsprodukter på rätt sätt. I denna avhandling utfördes en första utvärdering av mekaniska egenskaper hos briketter av avfallsprodukter. Tre olika CaO- innehållande avfallsprodukter (Mesa, Kalk, Fly Ash) från Stora Enso och SCA pressades med ett   bindande   material   (AOD   slagg)   från   Outokumpu.   Dropptest   utfördes   för   att   testa slaghållfastheten hos de laboratoriegjorda briketterna. Tre  olika  parametrar  undersöktes  av  deras  påverkan  på  briketternas  slaghållfasthet:  1) Brikets sammansättning 2) Värmebehandlingsförfarande 3) Exponeringstid för friluft. Totalt 97 briketter pressades. Dropptestresultat visar att för olika materialbaserade briketter hade värmebehandling   och   exponering   för   utomhusluft   ett   annat   inflytande   på   den   slutliga slagstyrkan.  För  att  få  bästa  slaghållfasthet,  värmebehandlades  MB-briketter  (90%  Mesa  + 10% AOD-slagg) värmebehandlad vid 850 ° C, KB-briketter (90% Kalk + 10% AOD-slagg) vid 850  °  C  och  FC-briketter  (80%  Fly  Ask  +  20%  AOD  slagg)  utsatt  för  öppen  luft  i  20  dagar rekommenderas. Smältningsexperiment utfördes för att undersöka svavelfjernningsförmågan hos briketterna imetallurgiska processer. Termodynamisk beräkning av sulfidkapacitet gjordes.

Emissions of hydrogen sulfide (H2S) from construction and demolition (C & D) landfills can result in odors that are a significant nuisance to nearby neighborhoods and businesses. As Florida’s population continues to grow and create development pressures, housing is built closer to existing landfills. Additionally, new landfills will be created in the future. This research project was undertaken to develop a detailed modeling methodology for use by counties and other landfill owners to provide them with an objective and scientifically defensible means to establish odor buffer zones around C & D landfills. A technique for estimating methane (and odorous gas) emissions from municipal solid waste (MSW) landfills was recently developed by researchers at the University of Central Florida. This technique was based on measuring hundreds of ambient methane concentrations near the surface of the landfill, and combining that data with matrix inversion mathematics to back-solve the dispersion equations. The technique was fully documented in two peer-reviewed journal articles. This project extends that methodology. In this work the author measured ambient H2S concentrations at various locations in a C & D landfill, and applied those same matrix inversion techniques to determine the H2S emission rates from the landfill. The emission rates were then input into the AERMOD dispersion model to determine H2S odor buffer distances around the landfill. Three sampling trips to one C & D landfill were undertaken, data were taken, and the modeling techniques were applied. One problem encountered was that H2S emissions from C & D landfills are typically about 1000 times smaller than methane emissions (from MSW landfills). Thus, H2S iv ambient concentrations often are near the detection limits of the instruments, and the data may not be as reliable. However, this approach could be used for any particular C & D landfill if the appropriate amount of data were available to characterize its emissions with some certainty. The graphical tool developed in this work shows isopleths of "H2S" concentrations at various distances, and color codes the isopleths into a "green-yellow-red" scheme (analogous to a traffic signal) that depicts zones where private landowners likely will not detect odors, where they may experience some odors, or where they likely will experience odors. The "likelihood" can be quantified by selecting the Nth highest hourly concentrations in one year to form the plot. In this study, N was conservatively selected as 8. Requiring that concentrations be at or below the 8 th highest concentration in a year corresponds to a 99.9% probability of not exceeding that concentration at that distance in any future year. The graphical tool can be applied to any C & D landfill but each landfill is different. So this technique depends on having a fairly good estimate of the rate of emissions of H2S from the landfill in question, and at least one year’s worth of hourly meteorological data (wind speed, direction, and stability class) that is representative of the landfill location. The meteorological data can be obtained with relative ease for most locations in Florida; however, the emission data must be obtained from on-site measurements for any given landfill.