Early transition metal oxide clusters have been a focus of study for several years. The production of vanadium oxide cluster anions in a pulsed helium flow reactor provides a relatively precise way of introducing defect sites and controlling the oxidation state of the vanadium atoms. The composition of the clusters can be changed from the V2O5 stoichiometry, where the vanadium atom is in a +5 oxidation state, to more reduced stoichiometries yielding a mixture of oxidation states containing atoms in the +2 oxidation state. The subsequent addition of reactant gases such as H2O and SO2 yields very intense adsorption reactions as well as a demonstration of the robustness of particular defect free clusters. For example, the cluster has been identified as a defect free cluster where all vanadium atoms are in the +5 oxidation state and all oxygen atoms are predicted to be in the 2- state. The cluster has been shown to not adsorb SO2- while clusters in a reduced oxidation state, such as and readily adsorb one or more SO2 molecules. The adsorption process has been shown to be size dependent, with the smallest monovanadium oxide anions being the most reactive.

From the Proceedings of the 1973 Meetings of the Arizona Section - American Water Resources Assn. and the Hydrology Section - Arizona Academy of Science - May 4-5, 1973, Tucson, Arizona / Measurements of penetrability and hydraulic conductivity in calcareous soils treated with a dilute sulfuric acid solution showed a severe decrease in conductivity with increasing concentrations over 1000 ppm. A slight decrease in penetrability was observed. Carbon dioxide evolution appeared to be responsible for flow reduction and temporary cessation at 10,000 ppm and 20,000 ppm. In sodic soils penetrability and conductivity increased markedly with sulfuric acid concentrations between 1,000 and 10,000 ppm. For a neutral soil, penetrability decreased with increasing sulfuric acid concentrations, and the stable conductivity for 500 to 5,000 ppm was higher than for water alone. The findings suggest that disposal of sulfuric acid concentrations greater than 1,000 ppm will result in plugging by carbon dioxide. In sodic soils the possibility exists of using sulfuric acid solutions for reclaiming salt and sodium-affected soils.

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Thematic interrelation is an underdeveloped field of inquiry in Lukan studies. The design and elegance of Lukan theology begs for guided investigation into a possible system of organisation that governs history and theology, that is, narrative and theme. Based on the Greimasian Actantial Model, morpho–syntactical structural–critical analysis of Luke and Acts reveals that the covenant concept in its operative aspect of service functions as an organising principle, structuring the narratives and facilitating thematic interrelation. A survey of representative Lukan research consisting of five methodologically determined approaches shows a commonality regarding Lukan purpose. These all share the “plan of God” as a fundamental concept, thus intimating its plausibility as a common organisational principle in the text. This observation encourages further analysis of Lukan narrative and meta–narrative as relevant subject matter. Investigation into the purpose and goals of Ancient Jewish and Ancient Greek literature suggests that the concepts of piety/holiness and justness combined with a notion of divine order and expectation demonstrates organisational capacity. Under the terms and conditions of the Old Covenant three non–exclusive themes/concepts hold organisational functionality and ability to facilitate thematic interrelation: Exodus typology, the covenant concept and the eschaton idea. Exodus typology connects narrative with theme, developing Israel’s story. The covenant idea frames stories using parallelism and gives the meta–story progression. The eschaton idea presents the Day of YHWH as an organisational principle guiding the story of judgment to restoration. It is observed that the covenant concept is the most prevalent of these themes/ideas. Assuming the conceptual unity of Luke and Acts and adopting a morpho–syntactical structuralist approach, it was observed that the covenant concept in its operative aspect of service occurred as Helper at ten places, determining the development and structure of the meta–narrative. According to the Greimasian Actantial Model, Israel failed to fulfil its covenant–based mandate to serve God and shine God’s light of mercy to the nations. Jesus, Israel’s new Helper, becomes the Subject and by his covenant–based ministry, characterised as the greatest service, resolves the problem that prevents Israel from carrying out its divine mandate and sets the stage for its fulfilment. In Jesus Israel is given new leaders, an ethical platform of discipleship and the Holy Spirit. The apostle Paul as the epitomised and exemplary witness and servant of Jesus fulfils what Israel could not. He is vindicated in righteousness and shares in the Isaianic ministry of Jesus, to bear witness to leaders and to shine God’s light to the nations. Paul is unhindered in this ministry. Additionally, in thematic–critical terms, the key placement of the covenant concept in its operative aspect of service at plot–defining junctures features its catalytic dynamic as a “template” concept advancing the re–conceptualising of themes and providing a platform for meaningful relation. The evidence thus suggests that the covenant concept in its operative aspect structures the conjoined narratives of Luke and Acts. It also provides a basis for relation between the divine and humans in the context of the history of God’s salvation, linking history and theology, and makes possible a discernible means to thematic interrelation. The SO2 electrolysis was performed by supplying the anode of the cell with SO2 gas, while the water was fed to the cathode using graphite plates as flow fields. Initial experimental work was done at ambient pressures on the anode (SO2 gas–fed) and cathode (water–fed) after which the water pressure was increased from ambient to 1 bar. Various parameters were evaluated for SO2 electrolysis at ambient conditions, including operating temperature, membrane thickness and catalyst loading. The operating temperature was increased from 50oC to 80oC which resulted in a significant voltage improvement from 0.78V to 0.64V at 300mA/cm2. Operating the cell with thinner membranes (86 vs 170um) also resulted in an improved overall cell performance, while the catalyst loading (1 vs 0.5mgPt/cm2) had a negligible effect on the operating voltage. SEM images and EDX analysis were performed on the best performing MEA (N1135) which showed that no degradation of the MEA had occurred. / Thesis (M.Sc. (Chemistry))--North-West University, Potchefstroom Campus, 2011.

Thematic interrelation is an underdeveloped field of inquiry in Lukan studies. The design and elegance of Lukan theology begs for guided investigation into a possible system of organisation that governs history and theology, that is, narrative and theme. Based on the Greimasian Actantial Model, morpho–syntactical structural–critical analysis of Luke and Acts reveals that the covenant concept in its operative aspect of service functions as an organising principle, structuring the narratives and facilitating thematic interrelation. A survey of representative Lukan research consisting of five methodologically determined approaches shows a commonality regarding Lukan purpose. These all share the “plan of God” as a fundamental concept, thus intimating its plausibility as a common organisational principle in the text. This observation encourages further analysis of Lukan narrative and meta–narrative as relevant subject matter. Investigation into the purpose and goals of Ancient Jewish and Ancient Greek literature suggests that the concepts of piety/holiness and justness combined with a notion of divine order and expectation demonstrates organisational capacity. Under the terms and conditions of the Old Covenant three non–exclusive themes/concepts hold organisational functionality and ability to facilitate thematic interrelation: Exodus typology, the covenant concept and the eschaton idea. Exodus typology connects narrative with theme, developing Israel’s story. The covenant idea frames stories using parallelism and gives the meta–story progression. The eschaton idea presents the Day of YHWH as an organisational principle guiding the story of judgment to restoration. It is observed that the covenant concept is the most prevalent of these themes/ideas. Assuming the conceptual unity of Luke and Acts and adopting a morpho–syntactical structuralist approach, it was observed that the covenant concept in its operative aspect of service occurred as Helper at ten places, determining the development and structure of the meta–narrative. According to the Greimasian Actantial Model, Israel failed to fulfil its covenant–based mandate to serve God and shine God’s light of mercy to the nations. Jesus, Israel’s new Helper, becomes the Subject and by his covenant–based ministry, characterised as the greatest service, resolves the problem that prevents Israel from carrying out its divine mandate and sets the stage for its fulfilment. In Jesus Israel is given new leaders, an ethical platform of discipleship and the Holy Spirit. The apostle Paul as the epitomised and exemplary witness and servant of Jesus fulfils what Israel could not. He is vindicated in righteousness and shares in the Isaianic ministry of Jesus, to bear witness to leaders and to shine God’s light to the nations. Paul is unhindered in this ministry. Additionally, in thematic–critical terms, the key placement of the covenant concept in its operative aspect of service at plot–defining junctures features its catalytic dynamic as a “template” concept advancing the re–conceptualising of themes and providing a platform for meaningful relation. The evidence thus suggests that the covenant concept in its operative aspect structures the conjoined narratives of Luke and Acts. It also provides a basis for relation between the divine and humans in the context of the history of God’s salvation, linking history and theology, and makes possible a discernible means to thematic interrelation. The SO2 electrolysis was performed by supplying the anode of the cell with SO2 gas, while the water was fed to the cathode using graphite plates as flow fields. Initial experimental work was done at ambient pressures on the anode (SO2 gas–fed) and cathode (water–fed) after which the water pressure was increased from ambient to 1 bar. Various parameters were evaluated for SO2 electrolysis at ambient conditions, including operating temperature, membrane thickness and catalyst loading. The operating temperature was increased from 50oC to 80oC which resulted in a significant voltage improvement from 0.78V to 0.64V at 300mA/cm2. Operating the cell with thinner membranes (86 vs 170um) also resulted in an improved overall cell performance, while the catalyst loading (1 vs 0.5mgPt/cm2) had a negligible effect on the operating voltage. SEM images and EDX analysis were performed on the best performing MEA (N1135) which showed that no degradation of the MEA had occurred. / Thesis (M.Sc. (Chemistry))--North-West University, Potchefstroom Campus, 2011.

Physical activation of oil-sands fluid coke, a dense carbonaceous material, using sulfur dioxide (SO2) was investigated as a means of utilizing a plentiful and inexpensive waste for elemental mercury (Hg) removal. A new model was developed to elucidate physical activation of dense carbonaceous materials. Experiments and model simulations revealed that, during activation with SO2, a sulfur-rich porous layer is formed around the periphery of the coke particles; this porous layer reaches a maximum thickness as a result of diffusion limitations; the maximum porous layer thickness is controlled by activation conditions and determines the maximum achievable specific surface area (SSA). Pre-oxidation in air prior to activation, acid washing after activation and smaller coke particle size all result in higher SSA. The highest SSA achieved was 530 m2/g, the highest yet found for oil-sands fluid coke with physical activation. If present, oxygen out-competed SO2 for carbon during activation. SO2 activation and porous layer formation did not occur until oxygen was depleted. Sulfur added to coke through SO2 activation is mainly in reduced forms which are more thermally stable than elemental sulfur in commercial sulfur-impregnated activated carbons (SIACs). TGA and elemental analyses revealed that only 17% of sulfur was removed at 800°C from SO2-activated coke under inert conditions, compared with 100% from a commercial SIAC. The role of sulfuric acid (H2SO4) in vapor Hg capture by activated carbon (AC) was studied due to conflicting findings in the recent literature. In the absence of other oxidizing species, it was found that Hg could be oxidized by oxygen which enhanced vapor Hg adsorption by AC and Hg absorption in H2SO4 solution at room and elevated temperatures. At 200°C, AC treated with 20% H2SO4 reached a Hg loading of more than 500 mg/g, which is among the highest Hg capacities yet reported. When oxygen was not present, S6+ in H2SO4 was found to act as an oxidizer of Hg, thus enabling Hg uptake by H2SO4-treated AC at 200°C. Treating the AC with SO2 at 700°C improved the initial rate of Hg uptake, with and without subsequent H2SO4 treatment.

Physical activation of oil-sands fluid coke, a dense carbonaceous material, using sulfur dioxide (SO2) was investigated as a means of utilizing a plentiful and inexpensive waste for elemental mercury (Hg) removal. A new model was developed to elucidate physical activation of dense carbonaceous materials. Experiments and model simulations revealed that, during activation with SO2, a sulfur-rich porous layer is formed around the periphery of the coke particles; this porous layer reaches a maximum thickness as a result of diffusion limitations; the maximum porous layer thickness is controlled by activation conditions and determines the maximum achievable specific surface area (SSA). Pre-oxidation in air prior to activation, acid washing after activation and smaller coke particle size all result in higher SSA. The highest SSA achieved was 530 m2/g, the highest yet found for oil-sands fluid coke with physical activation. If present, oxygen out-competed SO2 for carbon during activation. SO2 activation and porous layer formation did not occur until oxygen was depleted. Sulfur added to coke through SO2 activation is mainly in reduced forms which are more thermally stable than elemental sulfur in commercial sulfur-impregnated activated carbons (SIACs). TGA and elemental analyses revealed that only 17% of sulfur was removed at 800°C from SO2-activated coke under inert conditions, compared with 100% from a commercial SIAC. The role of sulfuric acid (H2SO4) in vapor Hg capture by activated carbon (AC) was studied due to conflicting findings in the recent literature. In the absence of other oxidizing species, it was found that Hg could be oxidized by oxygen which enhanced vapor Hg adsorption by AC and Hg absorption in H2SO4 solution at room and elevated temperatures. At 200°C, AC treated with 20% H2SO4 reached a Hg loading of more than 500 mg/g, which is among the highest Hg capacities yet reported. When oxygen was not present, S6+ in H2SO4 was found to act as an oxidizer of Hg, thus enabling Hg uptake by H2SO4-treated AC at 200°C. Treating the AC with SO2 at 700°C improved the initial rate of Hg uptake, with and without subsequent H2SO4 treatment.

Submitted by Marco Antonio Oliveira da Silva (maosilva@ipen.br) on 2017-05-25T13:07:01Z No. of bitstreams: 0 / Made available in DSpace on 2017-05-25T13:07:01Z (GMT). No. of bitstreams: 0 / Durante a exploração de uma mina, vários impactos são causados no meio ambiente, entre eles a geração da drenagem ácida de minas (DAM), que consiste da exposição de minerais sulfetados ao ar, água e microorganismos do tipo ferroxidantes, apresentando reações de oxidação e formação de ácido sulfúrico solubilizando metais ali presentes contaminando o solo e as águas. O objetivo deste trabalho de pesquisa foi estudar uma solução tecnológica fazendo uso da oxidação avançada com ozônio de metais pesados presentes em efluentes contaminados, em mina de urânio, com especial foco na remoção do manganês. A mina de urânio das Indústrias Nucleares do Brasil INB, em Caldas, Minas Gerais, local de aplicação deste estudo, enfrenta o problema da DAM e tem como principais contaminantes de suas águas superficiais os elementos, alumínio (Al), manganês (Mn), zinco (Zn), ferro (Fe), sulfatos (SO4+2), fluoretos (F-), metais de terras raras, alem do urânio (U) e do tório (Th). Os testes com ozônio realizados em laboratório com os efluentes da INB e in situ, mostraram uma grande eficiência para remoção do ferro, manganês e cério em até 99%. A concentração total de manganês ficou abaixo dos limites estabelecidos pela resolução 430 e 357 do CONAMA. Elementos como neodímio (Nd), lantânio (La) e zinco (Zn) pouco se oxidam com O3. O Al se mantém praticamente inalterado, enquanto que o tório e o urânio decaem, mas com o passar do tempo de ozonização voltam a se concentrar, porém com um valor inferior ao inicial. O precipitado obtido após a ozonização consiste de até 85% de oxido de manganês. A fim de descartar, após a ozonização, o efluente líquido para o ambiente é necessário uma correção do pH, de modo a atender os parâmetros da legislação CONAMA, sendo utilizado 50 a 86% menos reagente (CaOH2), do que as quantidades utilizadas no processo adotado pela INB. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

Submitted by Pedro Silva Filho (pfsilva@ipen.br) on 2017-10-09T14:21:34Z No. of bitstreams: 0 / Made available in DSpace on 2017-10-09T14:21:34Z (GMT). No. of bitstreams: 0 / Durante a exploração de uma mina, vários impactos são causados no meio ambiente, entre eles a geração da drenagem ácida de minas (DAM), que consiste da exposição de minerais sulfetados ao ar, água e microorganismos do tipo ferroxidantes, apresentando reações de oxidação e formação de ácido sulfúrico solubilizando metais ali presentes contaminando o solo e as águas. O objetivo deste trabalho de pesquisa foi estudar uma solução tecnológica fazendo uso da oxidação avançada com ozônio de metais pesados presentes em efluentes contaminados, em mina de urânio, com especial foco na remoção do manganês. A mina de urânio das Indústrias Nucleares do Brasil INB, em Caldas, Minas Gerais, local de aplicação deste estudo, enfrenta o problema da DAM e tem como principais contaminantes de suas águas superficiais os elementos, alumínio (Al), manganês (Mn), zinco (Zn), ferro (Fe), sulfatos (SO4+2), fluoretos (F-), metais de terras raras, alem do urânio (U) e do tório (Th). Os testes com ozônio realizados em laboratório com os efluentes da INB e in situ, mostraram uma grande eficiência para remoção do ferro, manganês e cério em até 99%. A concentração total de manganês ficou abaixo dos limites estabelecidos pela resolução 430 e 357 do CONAMA. Elementos como neodímio (Nd), lantânio (La) e zinco (Zn) pouco se oxidam com O3. O Al se mantém praticamente inalterado, enquanto que o tório e o urânio decaem, mas com o passar do tempo de ozonização voltam a se concentrar, porém com um valor inferior ao inicial. O precipitado obtido após a ozonização consiste de até 85% de oxido de manganês. A fim de descartar, após a ozonização, o efluente líquido para o ambiente é necessário uma correção do pH, de modo a atender os parâmetros da legislação CONAMA, sendo utilizado 50 a 86% menos reagente (CaOH2), do que as quantidades utilizadas no processo adotado pela INB. / Dissertação (Mestrado em Tecnologia Nuclear) / IPEN/D / Instituto de Pesquisas Energéticas e Nucleares - IPEN-CNEN/SP

This thesis examines and tests acids and conditions, which make the production of nanoporous ceramic at the thin aluminium layer the most effective and provide the highest quality. This paper describes the production of nanoporous structures with pore size 15-400 nm, depending on the electrolyte. Creating a regular hexagonal structure by electrochemical oxidation is dependent on many parameters that affect the regularity of structure and parameters of the ceramics produced. They were investigated primarily by changes in temperature and input voltage. All results were examined by SEM analysis.