The interfacial reactions of Sn-Zn and Sn-Zn-Al solder balls with Au/Ni surface finish under aging at 150¢J were investigated. With microstructure evolution, quantitative analysis, elemental distribution by X-ray color mapping from an electron probe microanalyzer (EPMA), the reaction procedure of phase transformation was proposed. During the reflow, Au dissolved into the solder balls and reacted with Zn to form £^-Au3Zn7. As aging time increased, £^-Au3Zn7 transformed to £^3-AuZn4. Finally, Zn precipitated near the Au-Zn intermetallic compound. On the other hand, Zn reacted with the Ni layer and formed Ni5Zn21. But the Al-Au-Zn IMC formed at the interface of Sn-Zn-Al solder balls, the reaction of Ni with Zn was inhibited. Even though the aging time increased to 50 days, no Ni5Zn21 was observed. The Joule effect was more apparent than the electromigration in the biased solder balls. First of all, the new phase (Au, Ni)Zn4 was proposed in the biased condition and in 175¢Jaging. Secondly, the thickness of the Ni5Zn21 IMC were the same between the anode and the cathode. Finally, We directly measure the temperature of the biased solder balls which was up to 173¢J.

Neutrophils are among the first white blood cells recruited to the site of infection once microbial pathogens enter the host organism. At site, they perform a well-orchestrated chain of processes that aims to kill the microbial invader. Most prominent, neutrophils engulf microbes to inactivate them intracellularly, a process called phagocytosis. Alternatively, neutrophils can release neutrophil extracellular traps (NETs). NETs consist of chromatin decorated with antimicrobial effector proteins – a structure that can entangle bacteria and fungi. Neutrophils are crucial during fungal infections. This is reflected in the increased risk of fungal infections resulting of neutropenia. The concept of nutritional immunity describes every infection as a battle for resources. Those are mostly metal trace elements. For a long time, neutrophils were seen as powerful, but “mindless”, killers with a limited set of actions and no transcriptional capacity, but this view is in the flux. In the presented thesis, it was my goal to gain new insights into the interplay of neutrophils and fungi – with special attention to metal-nutritional aspects. We compared human neutrophils lacking the ability to undergo NETosis, due to a non-functional NADPH complex, and neutrophils from the same person that were “cured” by gene therapy. We investigated those NETs and found that their inhibitory activity towards the mold A. nidulans depends on calprotectin, a known zinc-chelator. Considering the high influx of neutrophils, we wanted to unravel the neutrophils’ contribution to the metal milieu at the site of infection and trace element changes resulting from NETosis. By combining synchrotron radiation XRF and ICP-MS, we analyzed the neutrophil metallome and the spatial element distribution in activated neutrophils and NETs. Most strikingly, we found neutrophils to be exceptionally high in Fe and the process of NETosis to be reducing available Zn in the surrounding and the early phagosome, possibly by the formation of Zn-rich vesicles. Using RNA-sequencing, we analyzed the interplay of the C. albicans and neutrophils face-to-face. We dissected their transcriptional profile and revealed a manifold response in neutrophils that include cytokine induction and cellular rearrangement. We further were the firsts to explore the transcriptional response of C. albicans to NETs. Our data indicates a distinct response compared to intact neutrophils or other known stress triggers. Metal homeostasis was affected in Candida in both set-ups. In summary, this thesis provides new insights into the interaction of fungal pathogens with neutrophils and emphasizes the impact of nutritional aspects on this interplay. A deeper understanding of the nutritional immunity during fungal infection might open up new strategies to tackle fungal infections – a growing threat worldwide.

Submitted by Everaldo Pereira (pereira.evera@gmail.com) on 2017-04-20T12:22:10Z No. of bitstreams: 1 Adriana_Gomes.pdf: 7159313 bytes, checksum: 1dd9c1bfa97bc7eb1dc75461fcbcc6b0 (MD5) / Made available in DSpace on 2017-04-20T12:22:10Z (GMT). No. of bitstreams: 1 Adriana_Gomes.pdf: 7159313 bytes, checksum: 1dd9c1bfa97bc7eb1dc75461fcbcc6b0 (MD5) / O Cráton do São Francisco abriga diversos pequenos depósitos de chumbo e zinco, associados aos Grupos Una e Bambuí, pertencentes ao Supergrupo homônimo. Posicionados neste contexto encontram-se os depósitos de Irecê (BA), Serra do Ramalho (BA) e Montalvânia (MG), todos encaixados em sedimentos carbonáticos neoproterozóicos. Diversas características, são comuns a esses depósitos. As rochas hospedeiras das mineralizações são dolarenitos, normalmente silicificados, posicionadas numa seqüência regressiva em fácies evaporíticas de águas rasas, caracterizando a presença de um controle litológico do minério. O minério sulfetado é constituído predominantemente por galena, esfalerita e pirita, com quantidades variáveis entre os depósitos, ocorrendo principalmente de forma disseminada, em bolsões e veios, cujos minerais de ganga são essencialmente dolomita, calcita, quartzo e barita, caracterizados como tipo stratabound, tardi-diagenética a epigenética, e também sin-sedimentar em Irecê. O controle estrutural, decorrente da reativação de antigas falhas e fraturas NW-SE do embasamento durante e após a sedimentação da bacia (evento Brasiliano/Panafricano) foi responsável pela circulação dos fluidos hidrotermais através de um extenso sistema hidrodinâmico em diferentes tempos durante o soterramento das unidades permeáveis, gerando dolomitização, silicificação, dissolução/colapso e mineralização nas rochas encaixantes. Todas as áreas estudadas apresentam temperaturas moderadas e mesma composição dos fluidos (sistema NaClCaCl2-H2O) com salinidades baixas a moderadas, indicando que os fluidos mineralizantes possuiam capacidades similares de lixiviação e transporte dos metais, sendo portanto a fonte dos metais e a tectônica da bacia os fatores diferenciais na formação do minério em cada depósito. As assinaturas isotópicas de chumbo determinadas em cada área são muito distintas, porém homogêneas, indicando uma consistência com a origem em uma única fonte para cada depósito ou com múltiplas fontes bem homogeneizadas, com exceção de Irecê (IL) que possui baixa homogeneidade, associada provavelmente a uma mistura de fontes. O elevado caráter radiogênico das razões isotópicas de Pb nos depósitos estudados fornecem idades futuras para as mineralizações e idades Arqueana/Paleoproterozóica para fonte em Serra do Ramalho e Irecê respectivamente, obtidas através de isócronas secundárias. Em Montalvânia, apesar de detectados valores menos radiogênicos do chumbo não foi possível a obtenção de espalhamento suficiente para gerar uma isócrona, o que pode refletir (i) uma fonte em rochas do embasamento menos radiogênica, inclusive com contribuição de chumbo ligado mais fortemente à estrutura do mineral hospedeiro, lixiviado devido a um maior tempo de interação fluido-rocha, ou (ii) uma mistura com chumbo menos radiogênico proveniente de sedimentos sobrejacentes às rochas do embasamento. A distribuição geográfica das razões isotópicas de Pb obtidas nas áreas estudadas dentro das Bacias São Francisco (MontalvâniaÎSerra do Ramalho / MZÎCAÎLBX) e Irecê (MGÎIL), mostra uma tendência de enriquecimento radiogênico no sentido de sul para norte. Essa distribuição corrobora a indicação de diferentes rochasfonte ou mistura de fontes, assim como a presença de rochas-fonte mais antigas ao sul das bacias. Entretanto, a linearidade das razões de 206/207Pb sugere uma mistura de fontes para os depósitos estudados. Quando se correlacionam as assinaturas isotópicas de enxofre, com as razões isotópicas de Pb obtidas nas galenas de cada depósito estudado, nota-se uma relação inversa, caracterizada por duas tendências em que: (1) razões isotópicas de chumbo geralmente mais altas são mais variáveis que as de enxofre, que possuem assinaturas mais pesadas, e (2) razões isotópicas de chumbo menos radiogênicas possuem um menor espalhamento e relaciona-se com razões isotópicas de enxofre mais leves e relativamente mais dispersas. Esses trends exibem ainda uma diferença entre os valores máximos e mínimos das razões isotópicas de enxofre iguais e da ordem de 13‰ CDT, sugerindo uma relação comum entre suas fontes e entre as condições químicas de formação dos sulfetos. Além disso, o trend que possui menor variação de Pb que enxofre vincula-se a depósitos com valores modais de salinidades e temperaturas mais elevados, os quais possuem condição mais efetiva para lixiviação e transporte de metais, inclusive em minerais com razões mais baixas de Pb. A relação inversa entre S e Pb nos diferentes depósitos sugere que uma pequena parte do enxofre foi transportada junto com os metais, e a influência de um evento mineralizador de grande escala regulado pelo efeito da tectônica global atuante nas bacias, guardando as particularidades inerentes a cada ambiente de deposição. As assinaturas isotópicas de enxofre de sulfetos e sulfatos em Serra do Ramalho-Montalvânia mostram-se homogêneas e altamente positivas indicando a água do mar em ambiente restrito como fonte do enxofre. As temperaturas moderadas encontradas indicam a redução termoquímica como processo de redução do sulfato. A determinação da causa do movimento dos fluidos mineralizantes, embora exija ainda mais estudos é sugerida nesse trabalho como sendo resultante possivelmente, do soterramento de rochas permeáveis afetadas por uma tectônica extensional em um período onde o grau geotérmico da Terra era mais elevado (~50°C/km), sendo capaz de propiciar a movimentação de um extensivo sistema hidrodinâmico, no qual a migração dos fluidos (aquecidos e salinizados) em larga escala foram fundamentais nos processos de dolomitização, silicificação, dissolução hidrotermal e mineralização. / ABSTRACT The São Francisco Craton contains many small zinc and lead deposits, related to Una and Bambuí Groups belonging to the Bambuí Supergroup. In this context occur the neoproterozoic carbonate-hosted Irecê (BA), Serra do Ramalho (BA) and Montalvânia (MG) deposits, which share many characteristics. The host rocks are silicified dolarenite, placed in a shallow marine regressive sequence in the evaporitic facies, typifying a lithologic control of the ore. The sulfide mineralization is predominantly formed by galena, sphalerite and pyrite, with variable amounts among the deposits. They occur mainly in disseminated and veins form, within gangue minerals formed by dolomite, calcite, quartz and barite, characterized as stratabound late-diagenetic to epigenetic type. In Irecê, they are synsedimentary. The structural control is due to reactivated basement NW-SE ancient faults and fractures, during and after basin sedimentation (Pan African-Brasiliano Tectonic Cycle). It is responsible for circulation of hydrothermal fluids through a huge hydrodynamic system in different times during the burial of the permeable units, developing the dolomitization, silicification, dissolution/collapse and mineralization processes of the host rocks. In all the studied areas, moderate temperatures and similar fluid compositions (NaCl-CaCl2-H2O system) with low to moderate salinities were recorded, suggesting that the mineralized fluids of each studied area show similar potential of leaching and transportation of metals reflecting the metal source and the basin tectonics as differential factors in ore formation for each deposit. The lead isotopic data collected are very different in individual studied area, but in general they are homogeneous, suggesting a single source for individual deposit or multiple homogeneous sources, except Irecê (IL), which has low homogeneity, possibly associated with a source mixture. The high radiogenic character of the Pb isotopic ratios in the studies deposits provide future ages for the mineralization and Archean/Paleoproterozoic age for source in Serra do Ramalho and Irecê deposits, obtained by secondary isochrons. The lower Pb radiogenic values in Montalvânia were not sufficient to obtain dispersion for producing isochrons. This can be caused by (i) less radiogenic basement rocks with lead contribution from the mineral host structure, leached due to the long time of fluid-rock interaction, or (ii) mixture with less radiogenic lead derived from the overlaying sediments. The geographic distribution of Pb isotopic ratios obtained in the studied areas within São Francisco Basin (Montalvânia Î Serra do Ramalho / Zezinho Mine Î Campo Alegre Î Lajeado de Baixo) and Irecê ( MG Î IL) display a enrichment of light isotopes (32S) from south to north characterizing a trend. This distribution agrees with the different source-rocks or source-mixture, as well as old source-rock situated at the south of the basins. However, the linearity of the 206/207Pb ratios suggests a source of mixture from the studied deposits. When one correlates the sulfur isotopic signatures, with the Pb isotopic ratios obtained in galenas of individual deposits it is observed an inverse relationship, characterized by two trends: (1) lead isotopic ratios, general higher and more variable than the sulfur isotopic ratios, which have heavier signatures (2) lead isotopic ratios less radiogenic show a minor spreading and are related with sulfur isotopic ratios lighter and relatively more dispersed. These trends also display a coincident difference between the maximum and minimum of sulfur values in the order of 13‰ CDT, suggesting a common relationship among their sources and the chemical conditions of sulfide formation. Moreover, the trend that shows less lead variation than sulfur is related to deposits with high salinities and temperatures, which would have elevated capability to leach and transport, including minerals with lower Pb ratios. The inverse relationship between S and Pb in the different deposits suggests that a small part of the sulfur was transported together with metals, and the influence for the mineralization event of large scale controlled by global tectonic effect in the basins, preserving the particularities of each deposition environment. The sulfur isotopic signatures of sulfides and sulfates in Serra do Ramalho-Montalvânia areas are homogeneous and highly positive indicating sea water in restricted environments for sulfur source. The moderate temperatures suggest a thermochemical reduction as the formation process of sulfate. The driving-force of the hydrothermal fluids involved in mineralization has been yet subject of considerable debate. However, the collect data of this study suggests that the burial of permeable sequences affected by extensional tectonic during a period of higher geothermal gradient (~50°C/km), was able to put in movement a large hydrodynamic system, where a warm and saline fluid migration in a huge scale were very important in the dolomitization, silicification, hydrothermal dissolution and mineralization processes.

The Higdon deposit is located on the east flank of the St. Francois Mountains, approximately 11.5 km NE of Fredericktown, MO in the Mine LaMotte-Fredericktown district of the world renown Southeast Missouri (SEMO) region of Mississippi Valley-type (MVT) deposits. It was discovered in the 1950s and an attempt to mine the deposit was made in the 1960s. In the 2000s the importance of the Higdon deposit increased after extensive exploration by The Doe Run Mining Co. revealed a larger deposit, greater Ni-Co content than initially estimated and the presence of a low grade Unconformity-type Uranium deposit, similar to those of the Athabasca Basin in Canada. The overall paragenetic sequence, stratigraphy and stratigraphic controls of the Higdon deposit resembles those present in other SEMO MVT deposits located at the east flank of the St. Francois Mountains. The stratigraphy includes the Cambrian formations: Eminence, Potosi, Derby-Doe Run, Davis, Bonneterre and Lamotte which unconformably overlies Precambrian granitic intrusions. A common feature is the presence of collapse breccias especially at the base of the Bonneterre Formation and a relatively thin Lamotte Formation. Fine-grained, disseminated sulfides of Fe, Pb, Zn, Co and Ni are hosted in the lower one third of the Bonneterre Formation and upper two thirds of the Lamotte Formation, in a series of grainstone beds, open spaces in collapse breccias, near pinch outs of the Lamotte Formation against basement highs. Disseminations and nodules of pitchblende (uraninite) occur through the entire Lamotte Formation. The Higdon deposit differs in several important ways from the deposits of the Viburnum Trend on the west flank of the St. Francois Mountains. These differences include a distinctly lower stratigraphic interval of collapse breccias and mineralization, greater abundance of Co-Ni minerals, presence of pitchblende, and a significant fault control of mineralization. Several regionally extensive high angle faults aligned parallel to the NW-striking Simms Mountain and Mine LaMotte fault systems bound the deposit, especially the high Ni-Co-U portion. Petrographic and microprobe studies at Higdon revealed a mineral paragenetic sequence of uraninite (pitchblende, within a carbon matrix), pyrite, marcasite, chalcopyrite, bravoite, siegenite, gerdorsffite, sphalerite and galena. These minerals were deposited in four different stages: (1) a U dominated stage that precipitated the pitchblende during Early Ordovician to Permian time; (2) a Fe sulfide dominated sulfide characterized by pyrite, marcasite and bravoite; (3) a Cu-Co-Ni stage dominated by chalcopyrite and siegenite, and (4) a Zn-Pb stage characterized by the precipitation of sphalerite and galena. Precambrian uraniferous granitic intrusions in the vicinity of the Higdon deposit supplied the U for the pitchblende mineralization. At Higdon the U mineralization represents an overlapping deposit in an otherwise MVT system. This required leaching by fluids migrating through the basement along high angle faults and U precipitation in a reducing environment as the fluids encountered the Lamotte Formation. The Ni and Co were possibly leached from mafic and ultramafic intrusions along the Reelfoot Rift or from the Precambrian basement and transported to the Higdon area by fluids migrating along the regional NW-trending faults. Mixing with connate Pb-Zn brines moving laterally through the Lamotte Sandstone and other permeable units may have triggered the sulfide precipitation. Finally, the Higdon deposit is anomalous in the tonnage and grade of its Ni-Co resource (0.17 % Ni, 0.14 % Co) with significant values contained in siegenite (30.9 % Ni, 23.9 % Co), bravoite (0.04 % Ni, 6.3 % Co), gerdorsffite (26.1 % Ni, 8.0 % Co) and marcasite-pyrite (0.3 % Ni, 0.2 % Co).

Made available in DSpace on 2018-08-01T21:58:48Z (GMT). No. of bitstreams: 1 tese_10764_Dissertação final 26_06_17_Renan.pdf: 2290715 bytes, checksum: 01081df9fabe571c47da4d0246edb5f8 (MD5) Previous issue date: 2017-03-28 / No presente estudo, foram sintetizadas ferritas sem dopagem (Fe2O3/Fe3O4) e ferritas dopadas com manganês (MnFe2O4(R)) a partir de reagentes comerciais, bem como (MnFe2O4(B)) a partir de manganês recuperado de pilhas de Zn-MnO2 exauridas. O cátodo de pilhas Zn-MnO2 utilizado é constituído principalmente por MnO2 e Mn3O4, de acordo com análises de difratometria de raios-X (DRX). Análise por espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES) detecta a presença de zinco advindo do ânodo das pilhas. O manganês do cátodo foi lixiviado com ácido nítrico 0.5 molL-1 e utilizado como dopante na síntese de ferritas MnFe2O4(B). Os materiais sintetizados apresentaram características de MnFe2O4, de acordo com a difratometria de raios-X (DRX). As ferritas foram caracterizadas por microscopia eletrônica de varredura (MEV) e microscopia eletrônica de transmissão (MET). Nas micrografias verificou-se que os materiais apresentaram partículas e aglomerados em escala nanométrica com geometria variada e irregular. Pela análise de espectrometria de energia dispersiva de raios-X (EDS) acoplada ao MEV pôde-se observar a composição das partículas da ferritas sintetizadas. Obteve os picos de Fe e O na amostra de Fe2O3/Fe3O4 e de Fe, Mn e O nas mostras de MnFe2O4(R) e MnFe2O4(B). A composição química das ferritas foi determinada por dicromatometria para ferro e espectrometria de absorção atômica de chama (F AAS) para manganês, sendo de 66,6 % de Fe para a Fe2O3/Fe3O4, 56,6 % de Fe e 11,5 % de Mn para MnFe2O4(R) e 61,5 % de Fe e 4,5 % de Mn para MnFe2O4(B). As ferritas foram avaliadas cataliticamente na descoloração do corante azul de metileno através do processo foto Fenton heterogêneo, obtendo-se 15,6 %, 98 % e 92 % de descoloração do corante usando Fe2O3/Fe3O4, MnFe2O4(R) e MnFe2O4(B) respectivamente, em 120 minutos de reação.

No description available.

DEVELOPMENT AND CHARACTERIZATION OF PHOSPHOLIPID ENCAPSULATED QUANTUM DOT CONSTRUCTS FOR BIOLOGIC APPLICATIONS The American Cancer Society predicts that 577,190 cancer-related deaths and 1,638,910 newly diagnosed cases of cancer will occur in 2012. As these statistics show, cancer is a prevalent and devastating health issue; determined by the Mayo Clinic to be the second leading cause of death in the United States. Skin cancer is the most common form of cancer in the United States. In 2012 more than 68,000 Americans will be diagnosed with melanoma, 48,000 will be diagnosed with an early form of the disease that has not yet reached the lower levels of the epidermis, and more than 2 million people will be treated for basal cell or squamous cell skin cancer. Early and accurate detection is the most reliable way to ensure a positive outcome and the ultimate survival of the patient. As the most aggressive form of skin cancer, survival of melanoma is especially connected to early detection. Current methods for the initial detection of potential cancerous masses and lesions rely on visual examination, palpitation, and biopsy. Accurate determination of the presence of cancerous cells in a biopsy is especially difficult at the early stages when only a small percentage of cells in the biopsied mass show the morphological traits associated with being cancerous. This circumstance often results in a false negative (FN), delaying the necessary treatment until the cancer has reached a more developed stage. Developing more accurate methods for the detection of cancerous cells within a biopsy would aid in alleviating this problem. An improvement to the conventional method of visually examining biopsied tissues for the presence of cells with abnormal morphologies can be offered by utilizing the model of functionalized quantum dot (QD) constructs. Quantum dots are nano-particles composed of semi-conducting materials that fluoresce at discrete wavelengths when irradiated by a high energy UV source. QD constructs are cadmium-selenium/zinc-sulfide (CdSe/ZnS) quantum dots encapsulated within a bovine derived milk phospholipid micelle. QD constructs provide a potential mechanism for the identification of cancerous cells within a biopsy. Appreciating the scope of the clinical problem and understanding the potential of QDs, the objective of this thesis is to develop a primary model for the solubilization, encapsulation, and primary phospholipid functionalization of two distinct sizes of CdSe/ZnS QDs. The first stage of this thesis optimized the currently utilized protocol for synthesizing cadmium-selenium (CdSe) quantum dots to develop a set of parameters for consistently producing white fluorescing CdSe cores (WFCs) and CdSe/ZnS QDs of 505nm and 555nm (+/- 10nm). The application of synthesis times, temperatures, and quenching methods were employed to achieve this. The second stage developed a phospholipid encapsulation method for the initial functionalization and suspension of the hydrophobic QDs in aqueous media via encapsulation within phospholipid micelles. The final stage of this thesis focused on the successful introduction of the QD constructs into keratinocyte cells. Calcein and Ethidium homodimer-1 stains were applied to determine cell viability, Histochoice was applied as a fixative, and Hoechst staining was employed for cell nuclei identification. Analysis using confocal microscopy suggests successful attachment of QD constructs, in 0.1% w/v keratinocyte media, to the exterior of keratinocyte cell membranes with a 30% average cell survival rate at 24 hours after sample introduction. Future research investigating the interaction of QD constructs with biologic mediums of greater physiological complexity, as well as application of a secondary functionalization, are the next steps on the path toward achieving a viable mechanism for targeting and identifying cancerous cells within a biopsy.

Steel is the worlds most used metal and 2016 the produced amount of steel was measured to a total1630 MT where the Blast Furnace (BF) - Basic Oxygen Steelmaking (BOS) process, which is the mostcommon steel process, stands for 75% of the world’s current crude steel production.The BOS process works by blowing oxygen at high velocity through a hot metal bath consisting of hotmetal from the blast furnace mixed with fluxing agents as slag formers and up to 30 weights% scrap.Due to the high focus on environmental aspects throughout the world, the importance of utilizing andrecycling scrap and by-products such as slag and dust has increased. But when byproducts are recycled,the risk of impurities in the refined hot metal increases. To be able to control the impurities and reducethe risk of getting off-specification end product, it is important to understand when and where theimpurities end up.Zinc and chromium are two of these impurities that may cause issues to the process. To prevent thisfrom happening BlueScope Steel, a steel plant based in Wollongong, Australia, with a productioncapacity of 3 million tons of crude steel, wants to find out where these elements come from and howthey partition. For zinc, it is observed that most of it will end up in the offgas, while for chromium it isnoted that the majority exits with the steel and slag. It is assumed for both elements that the missingamount enters with the shredded steel scrap (shred) to meet the required mass balance using industrialdata. Results showed that the shred needs to contain between 0.312% and 0.515% zinc in order tosatisfy the zinc balance for year 2014 to 2019. For chromium, the range is from 0.315% to 0.371%.Data analyses carried out using SIMCA UMETRICS, which is a multivariate program used to performPrincipal Component Analysis (PCA) and Partial Least Squares (PLS) regression, and normal regressionsdone in Excel showed that zinc in the crude steel cannot be used to calculate or predict the partitioningfactors for zinc between slag, melt and off gases, due to a R2 (Goodness of fit) of 0.144, where the highera R2 value is the better the fit to the model. Slag showed better results with an R2 of 0.473 This regressionwas only done for heats with Zn contents above the detection limit, so it will most likely only beapplicable to heats where relatively high amounts of zinc are expected to end up in the slag. The amountof zinc that ends up in the offgas was above 95% for all the heats modelled.For chromium, results for predicting the partitioning between slag and melt showed greater promise,an R2 of 0.663 was obtained for regression of chromium in crude steel, and an R2 of 0.566 was obtainedfor regression of chromia in the slag. Both values are considered acceptable when analyzing plant data.When comparing the two, using the regression from chromium in the crude steel gives a slightly moreaccurate result, with a partitioning difference of only +/- 0.03 and a 97-99% accuracy, compared to +/-0.05 for chromia in the slag with a 95-98% accuracy.The model is used to compare how different amounts of shred will impact the partitioning of the twoelements analyzed. It also looks at how newer generations of filter cake, containing higher amounts ofzinc will impact the partitioning of zinc between the phases, especially the concentration of zinc thatreports to the dust.

<P> The equilibrium behavior of the boundaries separating the a and y crystalline phases in the copper zinc alloy system is investigated by measuring the magnitude, the relative anisotropy and the temperature dependence of the interfacial energies. A model, consistent with the interfacial energetics, is proposed and supported by observations of misfit dislocations at the boundary. The migration kinetics of the y/β interface are determined for both dendritic and polyhedral morphologies and the atomic mechanisms of growth are inferred from the. internally faulted ordered y precipitates. </p> / Thesis / Doctor of Philosophy (PhD)

No description available.