Dissertations / Theses: 'Iron air'

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Brown, Robert Alexander. "The combustion of titanium powder in air and iron oxide." Thesis, University of Nottingham, 2000. http://eprints.nottingham.ac.uk/28106/.

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The quest for ever stronger and tougher steels has lead to an interest in the 'Acicular Ferrite' microstructure, its chaotic and disordered morphology imparting a high degree of toughness to the steel. To date, only complex and expensive materials and manufacturing processes have formed acicular ferrite within bulk cast steel. As such, the thrust of this research is to produce a cheap steel addition, an iron - titanium oxide metal-ceramic composite, that will facilitate the formation of acicular ferrite in conventionally manufactured bulk cast steels. The Self-propagating High-temperature Synthesis (SHS) process has been utilised to manufacture the iron - titanium oxide material from compacts pressed from Fe203 + Ti powders. The fundamental reactions that occur as titanium powder and Fe203 + Ti powder compacts are heated in air and argon atmospheres have been investigated. The process’s involved are reported and have been modelled mathematically. A computer simulation of the reaction process has been developed and tested against experimental evidence. The effect of various compact parameters, the starting compact stoichiometry and other processing variables have been examined with respect to the composition of the products and their morphology.

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Donuk, Atilla. "Modeling And Design Of Iron-core Shunt Reactors With Discretely Distributed Air-gaps." Phd thesis, METU, 2012. http://etd.lib.metu.edu.tr/upload/12614923/index.pdf.

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In this research work detailed parallel and series equivalent circuits of a gapped iron-core shunt reactor with discretely distributed gaps are derived. The validity of the recommended equivalent circuits is verified by Finite Element Analysis and laboratory tests. Effects of fringing flux and discretely distributed gaps on inductance parameters and reactor losses are also investigated. Moving Strip Method for discretely distributed gapped shunt reactors is recommended. Two design procedures for shunt reactor with discretely distributed gaps are developed within the scope of this thesis. A simple and practical design approach is also developed which does not need any Finite Element Analysis software. This practical method is very useful for design engineers and researchers. The results of practical design approach are shown to be in good agreement with Finite Element Analysis and experimental work.

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Acquaviva, Alessandro. "Analytical Modeling of Iron Lossesfor a PM Traction Machine." Thesis, KTH, Elektrisk energiomvandling, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-105477.

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Permanent magnet (PM) machines offer several advantages in traction applications such as high efficiencyand high torque per volume ratio. The iron losses in these machines are estimated mostly with empiricallaws taken from other types of machines or with finite element simulations (FEM). In the first part of thisthesis the objective is to define an accurate analytical model for the stator yoke, teeth and rotor of a PMmotor which should work well enough for all operating point (different loads and frequency).This analytical model is found using an iterative process. After building a loss matrix and flux matrix basedon FEM simulations, it is possible to curve fit each of the lines or the rows of the matrix in order to achievethe best fitting for every operating point. This is a very new approach; it was shown that it gives thepossibility, even with a very limited number of FEM simulations, to achieve an accurate estimation of thelosses.The second part of this report focuses on optimizing this analytical method, comparing it with otherpossibilities, analyzing limits and advantages. Special attention is also given to the effects of the losses onthe temperatures in different parts of the machine. In the last part of the thesis, the analytical model isused to test a new control strategy. Its goal is to reduce the total losses of the motor and optimize the ratiobetween torque and total losses for a given driving cycle.

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Ohmori, Hiroko. "A Numerical Study of Solid Oxide Iron-Air Battery:Thermodynamic Analysis and Heat and Mass Transfer Characteristics." 京都大学 (Kyoto University), 2016. http://hdl.handle.net/2433/215529.

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Hailom, Yosef Futsum. "Solidification of iron and nickel base alloys and its relation to hot crack and air gap formation /." Stockholm : Casting of Metals, Royal Institute of Technology, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3856.

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Paul, Michael. "The catalytic effect of vanadium, iron and lead on the air oxidation of pile grade A graphite." Thesis, University of Bristol, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.385529.

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Smith, Kevin Richard. "The Role of Iron and Reactive Oxygen Species in Particulate Air Pollution-Dependent Biochemical and Biological Activities." DigitalCommons@USU, 1999. https://digitalcommons.usu.edu/etd/4342.

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Particulate air pollution is known to exacerbate respiratory diseases, such as asthma and chronic obstructive pulmonary disease, in humans. It has been proposed that transition meta ls from inhaled particles may play a role in this exacerbation by generating radical species leading to damage in the lungs. The aim of this research was to determine the role that iron from particulate air pollution played in the generation of reactive oxygen species and subsequently the induction of inflammatory mediators in cells in culture. The production of reactive oxygen species by particulate air pollution was found to be dependent on the mobilization of iron from the particles by chelators, such as the physiologically relevant citrate. The amount of iron mobilized from the combustion particulate, coal fly ash, was dependent on the type of coal used to generate the fly ash and was greatest in the smallest size fraction collected for three different coal types. In addition, the amount of iron mobilized from coal fly ash by citrate correlated closely with the amount mobilized in human lung epithelial (A549) cells, as indicated by induction of the iron storage protein, ferritin. The amount of the proinflammatory cytokine, interleukin-8, secreted in response to coal fly ash treatment varied with the amount of iron mobilized intracellularly from the particles, with the greatest response to the smaller size fractions which released the largest amounts of iron. There was a direct relationship, above a threshold level of bioavailable iron, between the level of interleukin-8 and bioavailable iron in cells treated with coal fly ash. Tetramethyl thiourea and dimethyl sulfoxide prevented the increased production of interleukin-8 by human lung epithelial cells treated with coal fly ash, suggesting the role of a radical species in the induction of this inflammatory mediator. The mobilization of iron from coal fly ash by citrate or in human lung epihelial cells, as well as the induction of interleukin-8, did not correlate with the total amount of iron in the particles. Instead, preliminary results suggest that these measured values vary directly with the amount of iron contained in the aluminosilicate fraction of the fly ash.

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Omur-Ozbek, Pinar. "Macromolecular Reactions and Sensory Perception at the Air-Water-Human Interface." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/77226.

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During 20th century main concern was to have sanitary water flowing through the tap. In 21st century constant supply of safe drinking water is common at any home in USA. Hence consumers pay attention to aesthetic quality of tap water. Odorous algal metabolites in source water and metals introduced to drinking water due to corrosion of pipes in the distribution system cause taste, odor and color problems, and result in complaints and perception of tap water as unhealthy. Millions of dollars are spent each year by water industry to address and prevent these issues. This research focused on some of the taste-and-odor issues associated with drinking water. First aim was to understand when geosmin, 2-MIB, and nonadienal become detectable, employing two-resistance mass transfer theory to determine the concentration of odorants in bathroom air. Results showed that water temperature and odorant concentration in water play an important role. Next focus was to develop an international odor standard to be used for training of sensory analysis panelists. There are many sensory methods to monitor drinking water to detect the off-flavors however an odor standard has been missing. Hexanal was studied with trained flavor profile analysis panels and was proposed as an ideal odor reference standard to be used for training and sensory assessment of water samples. Main focus was to understand metallic flavor of drinking water caused by iron and copper. It was shown that metallic sensation has taste and retronasal components creating the flavor and humans are very sensitive to it. Occurrence of lipid oxidation in the oral cavity was shown when metals were ingested, that produces carbonyls which are responsible for the metallic flavor. Antioxidants and chelators were investigated to study prevention of lipid oxidation and, chelators were determined to be more effective. Oral epithelial cell cultures were developed as a model for oral cavity to further investigate lipid oxidation and effectiveness of the antioxidants and chelators. This dissertation is a result of inter-disciplinary work and possibly a good example for how problems may be solved by incorporating different methods and point of views from several disciplines. Ph. D.

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Uliana, Alexandro. "A célula pneumática e sua aplicabilidade à flotação reversa do minério de ferro itabirítico." Universidade de São Paulo, 2017. http://www.teses.usp.br/teses/disponiveis/3/3134/tde-03082017-084519/.

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A realização deste estudo teve por objetivo caracterizar o funcionamento de uma célula pneumática de flotação e comparar o seu desempenho às diferentes tecnologias [células mecânicas e colunas de flotação] já instaladas e em operação nos circuitos industriais da Samarco Mineração - no Circuito de Grossos e no Circuito de Finos. Utilizou-se, para a realização dos ensaios e/ou das análises, uma célula mecânica laboratorial [modelo Wemco®], uma célula pneumática piloto [modelo MBE®] e um medidor de tamanho de bolhas e de velocidade superficial do ar [modelo APBS®]. Neste estudo, utilizaram-se amostras coletadas na alimentação dos dois referidos circuitos industriais de flotação - executando-se, posteriormente, etapas complementares de caracterização mineralógica, levantamento de dados e análise estatística dos resultados. Como conclusões, em maior relevância, citam-se: a) Para as células pneumáticas, maiores aplicabilidades industriais foram identificadas para o modelo Pneuflot®, processando carvão e em operações na China. Foram mapeadas células de 4,1 a 5,0 m de diâmetro processando volumes de polpa superiores a 1.000 m3/h; b) Em análise de influência das variáveis, foi identificado que o percentual de sólidos da alimentação e a velocidade da polpa no distribuidor possuem elevada influência sobre as variáveis respostas do processo de flotação; c) Em célula pneumática, em escala piloto e em regime batch, observou-se que: para a flotabilidade de sílica, a constante cinética (k) foi fortemente influenciada pela granulometria, sendo de 0,719 min-1 para a amostra CG e de 0,237 min-1 para a amostra CF; d) Utilizando-se de modelos cinéticos, dimensionaram-se circuitos de células pneumáticas. Conforme especificações atualmente praticadas e sem otimizações, seriam necessárias 8 células para o Circuito de Grossos e 11 células para o Circuito de Finos. e) Em comparativos entre células mecânicas e colunas de flotação [em escala industrial], constataram-se maiores eficiências de circuitos contendo células pneumáticas [dimensionados a partir de resultados em escala piloto]; e f) Em análise de dispersão do ar, realizaram-se medições e/ou identificação das correlações existentes entre as variáveis velocidade superficial do ar (Jg), diâmetro médio de bolhas ou diâmetro de Sauter (d32), hold-up do ar (Eg) e fluxo superficial de área de bolhas (Sb). This study aimed to characterize the operation of pneumatic cells and compare their performance to other different technologies [mechanical cells and columns] already installed and in operation in the industrial circuits of the company Samarco Mineração - Circuit of Coarse materials and Circuit of Fine materials. It was used, for the tests and/or assays, a laboratorial mechanical cell [Wemco® model], a pilot pneumatic cell [MBE® model] and a bubbles size and superficial air velocity measurer [APBS® model]. For these, feed samples of both industrial flotation circuits were taken - followed by complementary steps of mineralogical characterization, data collection and statistical analyzes of results. As conclusions, in higher relevance, have been noted: a) For the pneumatic cells, larger industrial applications were identified for the Pneuflot® model, processing coal and in operation in China. Cells measuring from 4,1 to 5,0 m of diameter were listed processing volumes higher than 1.000 m3/h; b) In an analysis of the influence of variables, it was identified that the percentage of solids in the feed and the velocity of slurry in the distributor have high influence on the process responses of flotation; c) In a pneumatic cell, on a pilot scale and under batch regime, for the floatability of silica, the kinetic constant (k) was strongly influenced by the size of particles, of 0,719 min-1 for the sample CG [from Coarse Circuit] and of 0,237 min-1 for the sample CF [from Fine Circuit]; d) Using kinetic models, circuits of pneumatic cells have been designed. According to the current specifications and without optimizations, 8 cells would be necessary for the Coarse Circuit and 11 cells for the Fine Circuit; e) In comparisons between mechanical cells and columns [on an industrial scale], greater efficiencies were noted for circuits containing pneumatic cells [designed from results on a pilot scale]; and f) In an analysis of the air dispersion, measurements and/or identification of existing correlations between the variables superficial air velocity (Jg), bubble size diameter (d32), air hold-up (Eg) and superficial area bubble flux (Sb) have been done.

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Li, Dazhi. "Synthesis and Applications of Novel Chiral NHC Precursors. Synthesis of Urea Derivatives through Decomposition of Cu-NHC under Air. Iron-mediated Synthesis of Dihydroquinoxalinones." Doctoral thesis, Université Laval, 2019. http://hdl.handle.net/20.500.11794/37234.

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Depuis sa première isolation, les ligands carbènes N-hétérocycliques (NHC) s’avèrent très utiles pour la coordination avec les métaux de transition ainsi que pour la catalyse. Étant abondant et moins onéreux, le fer en tant que catalyseur a connu un essor considérable au cours de ces dernières décennies. De nombreux Fe-NHCs ont été synthétisés, mais le Fe-NHC chiral utilisé pour la catalyse asymétrique en est encore à ses débuts. En comparaison avec les métaux rares, le cuivre en tant que métal de transition polyvalent et moins coûteux, a également suscité beaucoup d’attention. Cependant, le développement du Cu-NHC chiral en tant que catalyseur efficace reste difficile. Ainsi, plusieurs types de nouveaux précurseurs de ligand NHC chiral ont été synthétisés. Les synthèses de Fe-NHCs et de Cu-NHCs chiraux ont été initiées à partir des précurseurs chiraux. Il a été constaté que les Fe-NHCs et les Cu-NHCs se décomposent au contact de l’air. Les Fe-NHCs et Cu-NHCs chiraux générés in situ sont utilisés dans les réactions d'hydrosilylation, les réactions de Mukaiyama aldol, l'insertion de carbène métallique dans la liaison SiH et les réactions de type Heck. Les Fe- NHCs in situ se sont avérés non utilisables dans la réaction d'hydrosilylation de l'acétophénone. Pour les réactions de Mukaiyama aldol, les conditions d'utilisation de Fe-NHCs in situ ont permis d'obtenir les produits souhaités avec un rendement allant jusqu'à 88%. Cependant, aucune énantiosélectivité n'a été observée, probablement pour des raisons de désactivation du ligand NHC. La réaction d'insertion du métal-carbène dans la liaison SiH catalysée in situ par des Cu-NHCs a donné un rendement pouvant atteindre 84% et 24% ee de produit. En outre, les réactions de type Heck ont été testées avec un catalyseur chiral Pd-NHC, qui a aboutit à un rendement supérieur à 91% sans avoir fournir d’énantiosélectivité. De plus, les décompositions de différents types de Cu-NHCs et Ag-NHCs dans des solutions sous air humide ont été étudiées. L’hydrolyse et l’oxydation de Cu- NHCs ont généré, sous air, des imidazoliums et des dérivés d'urée. Les Ag-NHCs ont été hydrolysés pour donner des formamides ou des imidazoliums en solution sous air humide. Par la suite, une nouvelle méthode de synthèse du dérivé d'urée utilisant du cuivre et de l'air en tant qu'oxydant a été developpée. Elle a permis d'obtenir des rendements modérés voire même très bons pour des substrats sans encombrement stérique. Les conditions d'oxydation douces conviennent à la synthèse de dérivés d'urée possédant des groupes alkyle, benzyle, aryle, hydroxy primaire, un groupe tertbutyloxycarbonyle sensible aux acides et des groupes amine tertiaire. Dans le dernier projet, une synthèse générale et efficace des dihydroquinoxalinones énantiopures a été développée. La cyclisation réductrice de N-(o-nitroaryl)amino esters a été réalisée en utilisant du fer et du zinc métallique dans des conditions douces pour donner des dihydroquinoxalinones avec des rendements modérés à élevés et une pureté énantiomérique élevée. Since its first isolation, N-heterocyclic carbenes (NHC) have been found very useful to coordinate with metals and serve as ligand in catalysis. With the advantages of environmental friendliness, abundance and being less expensive, iron as a metal catalyst has received growing attention in recent decades. Despite that many Fe-NHCs have been synthesized, chiral Fe-NHC for asymmetric catalysis is still in its infancy. In comparison to precious metals, copper as a versatile and less expensive transition metal also has recieved much attention. However, the development of chiral Cu-NHC as efficient catalyst is still challenging. Thus, several types of novel chiral NHC ligand precursors have been synthesized. The synthesis of chiral Fe-NHCs and Cu-NHCs were attempted using those chiral precursors. It was found that the Fe-NHCs and Cu-NHCs would decompose under air. On the other hand, the applications of in situ generated generated chiral Fe-NHCs and Cu-NHCs were carried out for hydrosilylation reactions, Mukaiyama aldol reactions, insertion of metal-carbene into SiH bond and Heck-type reactions. The in situ generated Fe-NHCs were found not applicable in the hydrosilylation of acetophenone. For the Mukaiyama aldol reactions, the conditions using in situ generated Fe-NHCs led to the desired products in up to 88% yield. However, no enantioselectivity was observed for all attempts, probably due to the deactivation of NHC ligand. The insertion reaction of metal-carbene into SiH bond catalyzed by in situ generated Cu-NHCs afforded up to 84% yield and 24% ee of product. Besides, the Heck-type reactions were tested using a chiral Pd-NHC as catalyst. The reactions afforded up to 91% yield, but no enantioselectivity was observed. Furthermore, the decompositions of different types of Cu-NHCs and Ag-NHCs in solutions under humid air were studied. The Cu-NHCs underwent hydrolysis and oxidation to generate imidazoliums and urea derivatives under air. The Ag-NHCs were hydrolyzed to yield formamides or imidazoliums in solution under humid air. Subsequently, a new synthetic method of urea derivative using copper and air as oxidant was developed, which provided moderate to very good yields for sterically unhindered substrates. The mild oxidation conditions are suitable for the synthesis of urea derivatives possessing alkyl, benzyl, aryl, primary hydroxy, acid-sensitive tertbutyloxycarbonyl group, and tertiary amine groups. In the last project, a general and efficient synthesis of enantiopure dihydroquinoxalinones has been developed. The reductive cyclization of N-(o-nitroaryl)amino esters was performed by using iron and zinc metal under mild conditions to afford dihydroquinoxalinones in moderate to high yields and high enantiomeric purity.

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Zhang, Xingxing. "STRANDED CORE TRANSFORMER LOSS ANALYSIS." UKnowledge, 2008. http://uknowledge.uky.edu/gradschool_theses/533.

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We will present the approaches used to investigating the power loss for the stranded core transformers. One advantage of using stranded core is to reduce power loss or enhance transformer efficiency. One difficulty in the modeling of this type of transformer is that the core is not solid (there are small gaps between core wires due to circular cross section). A two dimensional finite element method with nodal basis function for magnetostatic field was developed to study the effects of the small gaps between core wires. The magnetic flux densities are compared for the uniform (solid) cores and the stranded cores for various permeability values. The effects of different air gap dimensions in stranded core to the magnitude of magnetic flux density were also discussed. The results of the two dimensional study were applied to modify the B-H curves in a 3D simulation with an equivalent simplified uniformed core transformer model via Ansoft Maxwell 3D. This is achieved by output the magnitude of magnetic flux density at fixed points of mesh center. The total core loss of a transformer was predicted by integration of the losses of all elements.

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Tavares, Fernanda Vasconcelos Fonseca. "Compostos Ferruginosos no material particulado atmosférico da região metropolitana de Belo Horizonte." CNEN - Centro de Desenvolvimento da Tecnologia Nuclear, Belo Horizonte, 2015. http://www.bdtd.cdtn.br//tde_busca/arquivo.php?codArquivo=348.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior Amostras de solos, minério de ferro e material particulado atmosférico foram analisadas com o objetivo de se investigar as diferentes propriedades físico-químicas de seus compostos ferruginosos e, dessa forma, identificar se as fontes de emissão do material particulado atmosférico da Região Metropolitana de Belo Horizonte são de origem natural, como por exemplo, da ressuspensão de partículas de solo, ou de origem antrópica, proveniente dos processos de mineração e/ou beneficiamento do minério de ferro. O modelo numérico denominado Industrial Source Complex - Short Term Version 3 foi utilizado para simular os processos de dispersão atmosférica do material particulado emitido em decorrência das atividades de mineração de ferro de empreendimentos localizados no Quadrilátero Ferrífero de Minas Gerais. Os resultados dessas simulações numéricas auxiliaram na escolha da localização dos pontos de amostragem de material particulado, uma vez que indicaram os pontos de maiores concentrações desse poluente na atmosfera da área em estudo. As amostras de material particulado foram coletadas com um amostrador de ar de grande volume (Hi-Vol). Todas as amostras foram caracterizadas por fluorescência de raios-X, difração de raios-X, magnetometria e espectroscopia Mössbauer do 57Fe. Os resultados dessas análises composicionais e estruturais mostraram que as amostras de solo analisadas possuem altas concentrações de silício, alumínio, material orgânico e baixos teores de ferro na forma de óxidos de ferro com baixa cristalinidade. Por outro lado, as amostras de minério de ferro apresentaram altos teores de ferro, predominantemente na fase de hematita com elevado grau de pureza e cristalização. As amostras de material particulado atmosférico apresentaram ferro, na forma predominante de hematita, silício, alumínio e cálcio em sua composição principal. Por meio da espectroscopia Mössbauer foi possível identificar características distintas entre a estrutura hiperfina do 57Fe da hematita presente nas amostras de minério de ferro e da hematita presente nas amostras de solo, contribuindo, portanto, para a identificação e quantificação das espécies químicas do minério nas amostras de material particulado atmosférico. Os resultados finais evidenciaram que nas amostras de particulados atmosféricos das regiões localizadas mais próximas aos empreendimentos de mineração, os teores de hematita provenientes do minério de ferro são maiores, se comparados aos teores obtidos naquelas amostras de particulados de locais mais distantes desses empreendimentos. Constatou-se também que mesmo as regiões mais distantes dos empreendimentos minerários não estão isentas desses impactos atmosféricos causados pela emissão de material particulado, demonstrando, portanto, a necessidade do controle efetivo das emissões de material particulado das atividades relacionadas à mineração de ferro no estado de Minas Gerais. Samples of soil, iron ore and airborne atmospheric particulate matter were analysed with the main goal of investigating the different physicochemical properties of their ferruginous compounds and thereby identifying whether the sources of the particulate matter in the Metropolitan Area of Belo Horizonte are of natural origin, such as, resuspension of particles from soil, or due to anthropogenic origin arising from mining and processing of iron ore. The Industrial Source Complex - Short Term model (ISCST3) was used to simulate the atmospheric dispersion processes of particulate matter emitted as a result of iron mining activities in the Iron Quadrangle of Minas Gerais. The results of these numerical simulations aided in determining the location with highest concentration of particulate matter in the study area. Airborne particulate matter was then collected in each place using high volume air samplers (Hi-Vol). All samples were characterized by X-ray fluorescence, powder X-ray diffraction, magnetometry and 57Fe-Mössbauer spectroscopy. The results of compositional and structural analyzes showed that soil samples are rich in quartz, aluminum, organic material and have low contents of iron, mainly iron oxide with low crystallinity. The samples of iron ore, in turn, have high concentration of iron, predominantly in the hematite phase with high purity and crystallization. The samples of atmospheric particulate matter have iron, predominantly hematite, as well as quartz, aluminum and calcium. Mössbauer spectroscopy permitted the quantification of different characteristics based on the hyperfine structure of 57Fe of the hematite in iron ore samples and of the hematite in soil samples. These results contributed to the identification and quantification of the different hematite phases in the particulate material samples. The final results showed that the hematite content from iron ore present in the particulate matter from samples collected in regions located close to mining enterprises are higher those present in samples from more distant places, so that the direct influence of the extraction of iron ore upon the composition of the atmospheric particulate matter could be clearly proved. It could be also demonstrated that even regions more distant from the mining activities are not exempt from these atmospheric impacts indicating the need for effective control of particulate matter emissions from activities related to iron mining in the State of Minas Gerais.

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McCarthy, Julian Daniel. "U.S.S. Vincennes (CG 49) shootdown of Iran Air Flight." Monterey, California. Naval Postgraduate School, 1991. http://hdl.handle.net/10945/26327.

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Kerr, Robert A. "Connection limit states design teaching aid." Master's thesis, This resource online, 1994. http://scholar.lib.vt.edu/theses/available/etd-10242009-020036/.

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Beghoura, Houda. "Modélisation de l'impact du Fer particulaire d'origine sédimentaire sur les cycles biogéochimiques marins Air‐sea turbulent fluxes from a wave‐following platform during six experiments at sea, in JGR Oceans 124 (6), June 2019 Impact of inorganic particles of sedimentary origin on global dissolved iron and phytoplankton distribution, in JGR Oceans 124 (12), December 2019." Thesis, Brest, 2020. http://www.theses.fr/2020BRES0001.

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Il existe encore des incertitudes importantes concernant le cycle biogéochimique du fer, sa nature et la quantification de ses sources. Ce fer dissous (dFe) est considéré comme étant la forme la plus biodisponible ce qui a induit la sous-évaluation du rôle du fer particulaire (pFe) comme une source potentielle de dFe. Pourtant, la remise en suspension des sédiments libère davantage de pFe que de dFe. Dans ce contexte, ma thèse remet en question la vision traditionnelle du rôle du fer particulaire inorganique sédimentaire (pFeinorg) et propose la première modélisation de ce dernier comme source externe de dFe. Le modèle numérique PISCES a donc été adapté pour tenir compte d’un flux supplémentaire de fer en s’appuyant sur une climatologie de la dynamique à partir de la configuration NEMOPISCES globale à 2 degrés de résolution. Les simulations mettent en exergue la sensibilité de la biomasse phytoplanctonique à la forme de fer provenant des sédiments ; les limitations en macronutriments et celles en fer sont considérablement modifiées, ainsi que les gradients côte–large de chlorophylle. Le transport plus efficace du fer en tant que pFeinorg permet d’atteindre des régions éloignées de sa source. Son accumulation et sa dissolution dans les zones de convergences induisent via downwelling l’enrichissement de la surbsurface ; à ceci s’ajoute le processus de chute de la particule. Cependant, ces processus demeurent peu étudiés. Les tests de sensibilité ont montré que le gain (absence de chute) ou la perte (chute rapide) en fer dans l’océan, ou encore la prépondérance du pFe sur le dFe seraient modulés par le taux de dissolution. En revanche, la distribution de la chlorophylle est mieux représentée dans la mesure où les processus qui régissent la distribution du PFeinorg et du dFe qui en dérive sont, de concert, pris en compte. Une manière de mieux représenter les répercussions du fer sur les cycles biogéochimiques marins, serait de mieux contraindre les processus liés au PFeinorg There are still substantial uncertainties in the iron biogeochemical cycle, including those related to the nature and magnitude of its external sources.Dissolved iron (dFe) is considered to be the most bioavailable form, which led to the underestimation of the role of particulate iron (pFe) as a potential source of dFe. Yet sediment resuspension releases more pFe than dFe. In this context, my thesis challenge the traditional view of the role of sedimentary inorganic particulate iron (pFeinorg) and proposes the first modeling of pFeinorg as a new external source of dFe. For this purpose, the PISCES numerical model has been adapted to take into account an additional iron flux based on a climatology of dynamics from the global NEMO-PISCES configuration at 2 degrees of resolution. Simulations highlight the sensitivity of phytoplankton biomass to the sedimentderived form of iron ; macronutrient limitations and iron limitations are considerably modified, as are coastal – open ocean chlorophyll gradients.The iron is more efficiently transported as a pFeinorg, allowing it to reach regions far from its source. Its accumulation and dissolution in the zones convergence zones would allow via downwelling to enrich the subsurface; in addition to this, the process of particle sinking. However, few studies have been conducted on these processes. Sensitivity tests have shown that the gain (no sinking velocity) or loss (relatively fast sinking velocity) of iron in the ocean or the preponderance of particulate iron over dissolved iron would be modulated by the dissolution rate. However the distribution of chlorophyll is better represented to the extent that the processes governing the distribution of pFeinorg and the dFe derived from it are jointly taken into account. One way to better represent the impact of iron on marine biogeochemical cycles would be to better constrain the processes associated with pFeinorg

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16

Zat, Michely. "Remoção de compostos odoríferos de águas de abastecimento através de processos de aeração, dessorção gasosa e nanofiltração." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2009. http://hdl.handle.net/10183/18930.

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As atividades humanas em bacias hidrográficas introduzem nos cursos de água nutrientes que aceleram o processo natural de eutrofização, favorecendo a ocorrência de florações de algas e cianobactérias. Estas florações se caracterizam por um crescimento explosivo destes microrganismos. Entre os diversos impactos negativos trazidos pelas florações está a emissão potencial dos compostos 2-metilisoborneol (MIB) e geosmina (GEO), os quais conferem gosto e odor de mofo e terra a água. Estes compostos não são totalmente removidos pelos processos convencionais de tratamento de água – clarificação química, filtração em meio granular e desinfecção com cloro, e permanecem na água até seu consumo, ocasionando alto índice de rejeição do produto por parte da população consumidora. Desta forma, a pesquisa foi planejada para avaliar alternativas de processos de tratamento visando à remoção de compostos odoríferos na água. Além de MIB e geosmina, foram feitas investigações relativas a remoção de ferro (Fe+2), manganês (Mn+2) e enxofre (H2S), nos processos estudados. Estas formas são normalmente encontradas em ambientes redutores, como águas subterrâneas e no hipolímnio de lagos e reservatórios, podendo contribuir para a deterioração das características organolépticas da água, ocasionando gosto e odores desagradáveis na água potável. Os processos estudados na pesquisa foram aeração em cascata, dessorção gasosa e nanofiltração. Os mecanismos do primeiro e segundo processos são: a oxidação de formas reduzidas e a dessorção de compostos voláteis e gases da água para o ar. O sistema de nanofiltração remove contaminantes da água através de retenção física imposta pelo tamanho dos poros da membrana. Human activities in watersheds introduce nutrients to water bodies, accelerating the natural process of eutrophication and favoring the occurrence of algae and cyanobacterial blooms. The blooms are characterized by explosives growths of those microorganisms. Among the several negative impacts brought by the blooms is the potential emission of the compounds 2-methylisoborneol (MIB) and geosmin (GEO), which confer earthy and moldy taste and odor to drinking water. MIB and GEO are not completely removed by the conventional water treatment processes – chemical clarification, granular filtration and chorine disinfection, causing consumer’s rejection of the distributed drinking water This research was planned to evaluate the capability of alternative treatment processes to remove odorous compounds from water. Besides MIB and geosmin, the research encompassed tests with iron (Fe+²), manganese (Mn+²) and hydrogen sulfide (H2S). These species are usually found in reduced environments such as lake and reservoir hypolimnion and groundwater. They can cause problems associated with color, taste and odor in drinking water. Processes studied in the research were cascade aeration, air stripping and nanofiltration. Prevailing mechanisms in the first two processes are oxidation of the reduced forms by air oxygen and stripping of volatile compounds and gases dissolved in water to air. Nanofiltration systems remove contaminants dissolved in water by physical retention imposed by the membrane pore size.

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17

Poorkhabbaz, Alireza. "The influence of air pollution on plane (Platanus orientalis L.) /." Göttingen : Cuvillier, 2007. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015695899&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.

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18

CASIRAGHI, FABIO MARCO. "THE INTERPLAY BETWEEN PHOTORESPIRATION AND IRON DEFICIENCY." Doctoral thesis, Università degli Studi di Milano, 2016. http://hdl.handle.net/2434/347430.

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ABSTRACT Iron (Fe) is an essential micronutrient for plants as it takes part in major metabolic pathways such as photosynthesis and respiration and is linked to many enzymes that accomplish many other cellular functions (DNA synthesis, nitrogen fixation, hormone production). Fe deficiency reduces crop yields worldwide but particularly in plants grown on calcareous soils, which represent almost the 30% of the earth land surface. In the near future to cope with the increasing demand of food caused by a strong increase in world’s population (FAO estimates in 9 billion people by 2050), agriculture must be extended to marginal areas, many of which include calcareous soils. The most evident effect of Fe deficiency in plant leaves is a marked chlorosis caused by a decrease in chlorophyll biosynthesis, which may result in a reduction in CO2 assimilation rate. In these conditions leaves have low photo-synthetic activity but they absorb more light energy per chlorophyll mol¬ecule than required for photosynthesis, especially under high radiation. This results in a high risk for photoinhibitory and photooxidative dam¬ages in Fe-deficient leaves. The photorespiratory cycle can be considered in these circumstances as an energy dissipating cycle, operating between chloroplasts, peroxisomes, mitochondria and cytosol, which helps to protect chloroplasts from photoinhibition and plants from excessive accumulation of reactive oxygen species. We suggest that Fe deficiency leads to a strong impairment of the photosynthetic apparatus at different levels: an increase in the rate of CO2 assimilation in many biological repetition (+29%) was observed, suggesting a possible induction of photorespiratory metabolism. However, the variation was not significative and so further analysis must be required in order to reduce the variability among the repetition to get more reliable results. In addition, the reduction of CO2 assimilation can be also attributable to a reduced stomatal conductance or to a mesophyll-reduced utilization of CO2. Iron deficiency affects also amminoacid (aa) metabolism since the concentration of Ser and Gly, two aa involved in the photorespiratory metabolism, increased in leaves (+94% and +160%, respectively). Resupply of iron to Fe-deficient plants led to an increase in the concentration of some divalent cations other than Fe like Ca and Mn, whilst Na, Mg, Cu, Zn decrease as Fe sufficient condition are restored. On the other hand, as Fe deficiency proceeds during time, we observed a significant increase in Na, Mg, Zn, Mn content. This alterations suggest that Fe deficiency induces a metabolic imbalance in which other divalent cations are absorbed by unspecific transporter, due to their similar characteristics to Fe. Under our experimental conditions, ROS accumulation detected in cucumber plants grown in the absence of Fe could be attributable to an increase in the activity of enzymes involved in their formation or to a reduced detoxification. We observed a slight induction in the activity of Cu/Zn-SOD isoform whereas a reduction in Fe- and also in Mn-SOD isoforms activity was also recorded. At the same time, the concentration of H2O2 in the leaves of Fe-deficient plants was significantly higher (+40%). This overproduction could lead to an onset of oxidative stress which can lead to further cell damage at different levels also with the involvement of the photosynthetic apparatus. Fe deficiency also induces alterations in peroxisomes at different levels indicating modifications in the photorespiratory metabolism. The complete lack of Fe results in a strong inhibition of catalase activity (-35%). Nevertheless, we detect higher levels of catalase in Fe-deficient plants compared to the control condition. In Fesufficient condition the total activity of hydroxypyruvate reductase was fully attributable to the peroxisomal isoform (HPR1), while we recorded an equal distribution of the activity between the two isoforms, peroxisomal and cytosolic (HPR2) in plants grown under conditions of Fe deficiency. Moreover, the characterization of rice mutant plants defective in mitochondrial Fe importer allow us to investigate the involvement of this organelle in the photorespiratory metabolism during Fe deficiency. The partial loss of function of MIT (mit-2) affects the mitochondrial functionality by decreasing the respiratory chain activity. Furthermore, the transcriptome and the metabolome strongly change in rice mutant plants, in a different way in roots and shoot. Biochemical characterization of purified mitochondria from rice roots showed alteration in the respiratory chain of mit-2 compared to wild type plants. In particular, proteins belonging to the type II alternative NAD(P)H dehydrogenases strongly accumulated in mit-2 plants, indicating that mit-2 mitochondria activate alternative pathways to keep the respiratory chain working. The data obtained and exposed in this doctorate thesis, in agreement with what widely previously reported in literature, allow us to state that the absence or the low Fe bioavailability during the growth of the plants results in several alterations more or less reversible at different levels of the overall metabolic plant system.

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Avazpour, Abdoul Rasool. "The organisation and optimisation of domestic air transport services within Iran." Thesis, Loughborough University, 2001. https://dspace.lboro.ac.uk/2134/35239.

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Air transport is an important part of any major domestic transport system. Consequently significant insight, analysis and methodological effort is necessary to devise an analytical model of a domestic air transport network with a view to the optimisation. Since the advent of airline deregulation in the US in 1978, most domestic airlines have adopted a routing and scheduling strategy known as hub and spoke. The adoption of this system presents a major change to network planning and operations for most airlines. The hub and spoke system proposed in this dissertation is for developing countries and based on the domestic Iranian air transport network. The aim of the research is to devise a practical domestic air transport network system, capable of dealing with strategic aspects of network planning and evaluation.

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20

Covarrubias, Peña José Ignacio <1981&gt. "Physiological and Biochemical Aspects of Iron Nutrition in Grapevine." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4480/1/Covarrubias_Jos%C3%A9_tesi.pdf.

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The objective of this thesis was to study the response mechanisms of grapevine to Fe-deficiency and to potential Fe chlorosis prevention strategies. The results show that the presence of bicarbonate in the nutrient solution shifted the activity of PEPC and TCA cycle enzymes and the accumulation/translocation of organic acids in roots of Fe-deprived plants. The rootstock 140 Ruggeri displayed a typical behavior of calcicole plants under bicarbonate stress. The Fe chlorosis susceptible rootstock 101-14 reacted to a prolonged Fe-deficiency reducing the root activity of PEPC and MDH. Noteworthy, it accumulates high levels of citric acid in roots, indicating a low capacity to utilizing, transporting and/or exudating organic acids into the rhizosfere. In contrast, 110 Richter rootstock is capable to maintain an active metabolism of organic acids in roots, accumulating them to a lesser extent than 101-14. Similarly to 101-14, SO4 genotype displays a strong decrease of mechanisms associated to Fe chlorosis tolerance (PEPC and MDH enzymes). Nevertheless it is able to avoid excessive accumulation of citric acid in roots, similar as 110 Richter rootstock. Intercropping with Festuca rubra increased leaf chlorophyll content and net photosynthesis. In addition, intercropping reduces the activity of PEPC in roots, similary to Fe-chelate supply. Applications of NH4+ with nitrification inhibitor prevents efficiently Fe-deficiency, increases chlorophyll content, and induces similar root biochemical responses as Fe-EDDHA. Without the addition of nitrification inhibitors, the effectiveness of NH4+ supply on Fe chlorosis prevention resulted significantly lower. The aspects intertwined in this investigation highlight the complexity of Fe physiology and the fine metabolic tuning of grapevine genotypes to Fe availability and soil-related environmental factors. The experimental evidences reveal the need to carry out future researches on Fe nutrition maintaining a continous flow of knowledge between theoretical and agronomical perspectives for fully supporting the efforts devoted to convert science into practice.

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21

Covarrubias, Peña José Ignacio <1981&gt. "Physiological and Biochemical Aspects of Iron Nutrition in Grapevine." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2012. http://amsdottorato.unibo.it/4480/.

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The objective of this thesis was to study the response mechanisms of grapevine to Fe-deficiency and to potential Fe chlorosis prevention strategies. The results show that the presence of bicarbonate in the nutrient solution shifted the activity of PEPC and TCA cycle enzymes and the accumulation/translocation of organic acids in roots of Fe-deprived plants. The rootstock 140 Ruggeri displayed a typical behavior of calcicole plants under bicarbonate stress. The Fe chlorosis susceptible rootstock 101-14 reacted to a prolonged Fe-deficiency reducing the root activity of PEPC and MDH. Noteworthy, it accumulates high levels of citric acid in roots, indicating a low capacity to utilizing, transporting and/or exudating organic acids into the rhizosfere. In contrast, 110 Richter rootstock is capable to maintain an active metabolism of organic acids in roots, accumulating them to a lesser extent than 101-14. Similarly to 101-14, SO4 genotype displays a strong decrease of mechanisms associated to Fe chlorosis tolerance (PEPC and MDH enzymes). Nevertheless it is able to avoid excessive accumulation of citric acid in roots, similar as 110 Richter rootstock. Intercropping with Festuca rubra increased leaf chlorophyll content and net photosynthesis. In addition, intercropping reduces the activity of PEPC in roots, similary to Fe-chelate supply. Applications of NH4+ with nitrification inhibitor prevents efficiently Fe-deficiency, increases chlorophyll content, and induces similar root biochemical responses as Fe-EDDHA. Without the addition of nitrification inhibitors, the effectiveness of NH4+ supply on Fe chlorosis prevention resulted significantly lower. The aspects intertwined in this investigation highlight the complexity of Fe physiology and the fine metabolic tuning of grapevine genotypes to Fe availability and soil-related environmental factors. The experimental evidences reveal the need to carry out future researches on Fe nutrition maintaining a continous flow of knowledge between theoretical and agronomical perspectives for fully supporting the efforts devoted to convert science into practice.

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Alaei, Seyed Fatemeh, and Anette Andersson. "Privatization: What we learn from failure : A case study of Iran Air." Thesis, Högskolan Väst, Avd för företagsekonomi, 2014. http://urn.kb.se/resolve?urn=urn:nbn:se:hv:diva-6452.

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This thesis was conducted to assess how the privatization of Iran Air process managed in last efforts and how should it be in right way. It increases the knowledge about privatization in Iran and the need for it. Iran air as our case study is a flag-carrier airline company that is protected by government regulations and subsidies. We try to find the reasons for failure of privatization in Iran Air and their attempt on privatization. The method used to collect data was a qualitative methodology, consisting of semi-structured interviews with relevant managers, and knowledgeable professors and the official sites and press. In conclusion, we find that privatization is an important need for Iran Air Company and the main problems that are against Iran Air can be categorized to political, financial, and social. The effects of political connections are most pronounced in countries with high levels of corruption. Iran’s level of corruption and law enforcement environment are lower than those are in developed countries. The root of financial problems of government and the company is the deficiency of liquidity to compensate the debts, but the share did not sell. The social problem arises from the uncertainty of the future of employees of going private company. Decreasing the level of corruption and increasing law enforcement in country are general solution for political problem. Preparing transparent financial statements and fair evaluation of share base price are our suggestion to Iran Air. The staff must be sure of their future. Social Security Organization and employment laws of country or any other response organization must protect them

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23

Malakooti, Hossein. "Meteorology and air-quality in a mega-city : application to Tehran, Iran." Marne-la-Vallée, ENPC, 2010. http://www.theses.fr/2010ENPC1001.

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The influence of a mega-city on the atmospheric boundary layer and surface conditions was examined in the complex-terrain, semi-arid Tehran region using the Pennsylvania State University/National Center for Atmospheric Research fifth-generation Mesoscale Model (MM5) during a high pollution period. In addition, model sensitivity studies were conducted to evaluate the performance of the urban canopy and urban soil model "SM2-U (3D)" parameterization on the meteorological fields and ground level air pollutant concentrations in this area. The topographic flows and urban effects were found to play important roles in modulating the wind and temperature fields, and the urbanized areas exerted important local effects on the boundary layer meteorology. An emission inventory of air pollutants and an inventory of heat generation were developed and updated for 2005 in this work. Emissions from on-road motor vehicles constitute a major portion of the emission inventory and play the most important role in terms of contributions of air pollutants to the atmosphere in Tehran. By using a detailed methodology, we calculated spatial and temporal distributions of the anthropogenic heat flux (Qf) for Tehran during 2005. Wintertime Qf is larger than summertime Qf, which reflects the importance of heating emissions from buildings and traffic during cold and warm period respectively. Different urban parameterizations were used as a tool to investigate the modifications induced by the presence of an urban area in the area of interest. It was found that, for local meteorological simulations, the drag-force approach coupled with an urban soil model (DA-SM2-U) is preferable to the roughness approach (RA-SLAB). The comparisons indicated that the most important features of the wind, temperature and turbulent fields in urban areas are well reproduced by the DA-SM2-U configuration with the anthropogenic heat flux being taken into account (i. E. , "DA-SM2-U Qf: On" option). This modeling option showed that the suburban part of the city is dominated by topographic flows whereas the center and south of Tehran are more affected by urban heat island (UHI) forcing especially during the night. The chemical transport modeling, including a model sensitivity study, was used to investigate the impact of the different urban parameterization on the dispersion and formation of pollutants over the Tehran region. Results show that applying DA approaches leads to significant improvements in the simulated spatial and temporal distribution of air pollutant concentrations in the city area and affects significantly the size of the urban plumes.

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Jabarivasal, Naghi. "Indoor atmospheric radon in Hamadan, Iran : atmospheric radon indoors and around Hamadan city in Iran." Thesis, University of Bradford, 2010. http://hdl.handle.net/10454/5452.

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Radon gas may be a major air quality hazard issue inside the home. Radon (222Rn) comes from the natural breakdown of radioactive uranium (238U) via radium (226Ra) in soil, rocks, and water. Radon and its progeny contribute more than 50% of the total radiation dose to the human population due to inhalation; it can result in severe and fatal lung disease. This investigation has determined the radon concentrations in seventy-seven domestic houses in a mountainous area of Hamadan in Iran which were monitored using track-etch detectors of type CR-39 exposed for three month periods. The arithmetic mean radon concentration in Hamadan buildings was determined to be 80 Bqm-3 and also an average indoor annual effective dose equivalent for the Hamadan city population was calculated as 1.5 mSv. Maximum radon concentrations were noted during the winter and spring season. In addition to this, 28 water wells were monitored by utilizing a Sarad Doseman detector at hourly intervals over extended periods. Radon measurements were also carried out in the nearby Alisadr show cave, using Solid State Nuclear Track etch Detectors (SSNTDs) during the winter and the spring periods. In the cave, the average annual effective geometric and arithmetic mean dose for guides was 28.1 and 34.2 mSv respectively. The dose received by visitors was very low. Hamadan city is built on alluvial fan deposits which are the source of the local water supply. The data from the wells shows that the groundwater in these alluvial deposits influences the flux of radon. The atmospheric radon concentration measurement in wells above the water surface ranged from 1,000 Bqm-3 to 36,600 Bqm-3. There is evidence that radon-rich ground waters play a significant role in the transport of radon through the alluvial fan system. There is evidence that the radon concentrations in homes in Hamadan are greatly influenced by the porous nature of the underlying geology and the movement of groundwater within the alluvial fan.

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Jamshidi, Fatemeh. "Étude techno-typologique des assemblages lithiques du Pléistocène de deux sites paléolithiques en plein air : Band-e Pey (Basse-Caspienne) et Kouhrang (contreforts du Zagros)." Electronic Thesis or Diss., Toulouse 2, 2022. http://www.theses.fr/2022TOU20093.

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Les récentes recherches archéologiques en Iran ont abouti à la découverte de nouveaux sites paléolithiques en plein air sur le plateau iranien. Deux des découvertes récentes de ce type ont été choisies pour être étudiées ici. L'un des sites en plein air concerné s'appelle Band-e Pey et il est situé dans les forêts de la côte sud de la mer Caspienne et l'autre, nommé Kouhrang, se trouve dans les hautes terres des contreforts du Zagros. Les deux contiennent des centaines d'artefacts lithiques dispersés sur une vaste zone. Ces deux sites ont été étudiés en utilisant une approche techno-typologique lithique, puis en donnant un sens de datation comparative aux deux assemblages. En plus d'essayer de donner une idée de l'attribution chrono-culturelle, la structure de l'assemblage lithique des deux sites est comparée aux données climato-environnementales pour vérifier si l'on pouvait trouver une corrélation entre les deux variables de la technologie et de l'environnement et, par conséquent, pour étudier les stratégies d'adaptation. Le principal inconvénient ici est le contexte des découvertes et l'absence de tout dépôt daté de manière sûre. Pour pallier cette difficulté, les résultats de l'étude techno-typologique sont comparés aux données d'un large échantillon d'autres sites connus du Paléolithique moyen et supérieur d'Iran et d'Asie du Sud-Ouest à l'aide de statistiques multivariées. L'autre problème concerne la rareté des recherches paléoclimatiques en Iran qui rend difficile la reconstitution des conditions environnementales. L'analyse a toutefois pu indiquer que les deux sites en plein air étaient très probablement des camps de base avec une large variété d'activités. Compte tenu du fait que la principale séquence de réduction dans les deux sites est l'enlèvement d'éclats et que la fabrication d'outils à base d'éclats comme le fait que les outils dans les deux assemblages sont dominés par les types attribuables au Paléolithique moyen avec la présence de la technique Levallois, l'occupation principale des sites remonte à cette période. En plus de ce qui a été mentionné, l'assemblage de Band-e Pey semble expédiant, impliquant peut-être l'impact de l'environnement forestier tempéré sur la structure de l'assemblage, contrairement à Kouhrang, avec une meilleure conservation. Enfin, le résultat de la démarche comparative suggère que le modèle d'utilisation des territoires était plus de nature saisonnière à Kouhrang, alors que l'on pourrait envisager une durée d'occupation annuelle plus longue à Band-e Pey The recent Aarchaeological research in Iran has resulted in the discovery of some open-air Paleolithic sites across the Iranian Plateau which are seemingly found everywhere across the plateau. Two of the recent finds of this type have been chosen for study here. One of the open-air sites is named Band-e Pey, which is located within the forests of the Southern Caspian Sea shore and the other, named Kouhrang is in the highlands of the Zagros foothills. Both are containing hundreds of lithic artifacts dispersed across a vast area. It is intended here to study the two sites using lithic techno-typological approach and then, giving some sense of comparative dating to both assemblages. In addition to trying to give a sense of timeframe, the lithic assemblage structure of the two sites would be compared against climatic-environmental data to check whether one could find any correlation between the two variables of technology and environment and hence, to study adaptive strategies. The main drawback here is the surface nature of the findings and the lack of any securely dated deposit. To ameliorate this difficulty, the results of techno-typological study would be compared to the data from some other known Iranian and southwest Asian Middle and Upper Paleolithic sites with the help of multivariate statistics. Apart from the lack of any dated deposit, the other problem concerns the paucity of paleoclimatic research in Iran which makes it difficult to reconstruct the environmental conditions. As a result of lab and library research, the analysis indicated that both open-air sites were most probablybase camps with a variety of activities. Giving the fact that the main reduction sequence in both sites is the removal of flakes and the making of flake-based tools and the fact that tool category in both assemblages are dominated by the known Middle Paleolithic retouched varieties with the presence of Levallois technique, the main occupation of the sites was in Middle Paleolithic Period. In addition to what has been mentioned, Band-e Pey assemblage looks more expeditious, maybeimplying the impact of temperate forest environment on the assemblage structure, contrary to Kouhrang, with more significant conserved nature. Finally, the result of library research suggests that land use pattern was more of a seasonal nature in Kouhrang, while one could envisage longer yearly duration of occupation in Band- e Pey

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Kendirci, Recep. "Iron Age Aeolic Style Capitals in the Israel and Palestine area." Thesis, Uppsala universitet, Institutionen för arkeologi och antik historia, 2012. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-175941.

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This thesis contains descriptions and definitions of the Iron Age Proto-Aeolic capitals from Israel - Palestine area. The modern area, which my materials cover is Israel and Jordan. The time period of the capitals is between the 9th century BC and the late 8th or the beginning of the 7th century BC. Attention has been put on issues of typological characteristics, usage and time periods of the capitals and how this, through the new examples, described here for the first time, created a new typology and usage for the Proto-Aeolic capitals.

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27

Agudelo, Castañeda Dayana Milena. "Remoção de sulfeto de hidrogênio, ferro e manganês de águas de abastecimento através dos processos de dessorção gasosa, nanofiltração e oxidação com permanganato de potássio." reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2010. http://hdl.handle.net/10183/31781.

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Inúmeras regiões brasileiras apresentam problemas qualitativos em seus mananciais de abastecimento, originando dificuldades para a potabilização da água distribuída nas cidades. Geralmente, os consumidores julgam a segurança da água potável que bebem através de seus sentidos organolépticos. Os processos convencionais utilizados nas estações de tratamento de água não são efetivos na remoção de muitos compostos que causam cor, gosto e odor na água. Devido a isto, é comum que as companhias de saneamento recebam reclamações por parte dos consumidores sobre a qualidade da água distribuída. Dentre os compostos que causam gosto, odor e cor na água encontram-se o sulfeto de hidrogênio, o ferro e o manganês. O sulfeto gera um odor de “ovo podre”, perceptível a concentrações que variam entre 0,05 e 0,1 mg·L-1. Manganês e ferro estão associados principalmente a produção de cor e precipitados na água. Desta forma, o objetivo da pesquisa proposta foi estudar técnicas de tratamento alternativas as convencionais para controlar gosto, cor e odor na água potável pela presença de sulfeto de hidrogênio, ferro e manganês. Os processos investigados foram aeração em torre de dessorção, nanofiltração em membrana e oxidação com permanganato de potássio. Os testes foram realizados com água bruta oriunda do reservatório da Lomba do Sabão, em Porto Alegre. Os ensaios de oxidação anteriormente à clarificação físico-química constaram de 4 etapas. Na primeira, foram testados o cloreto férrico e o sulfato de alumínio, possibilitando a elaboração de diagramas de coagulação. Na segunda etapa, foi calculada a eficiência da coagulação na remoção de Fe(II), Mn(II) e H2S. Na terceira etapa, foi calculada a demanda do oxidante na água. Finalmente, na quarta etapa realizaram-se ensaios de oxidação do permanganato associado à clarificação físico-química. Os resultados mostraram que o processo de coagulação conseguiu remover o ferro satisfatoriamente, mas não o manganês. Nos ensaios usando permanganato os resultados mostraram que as remoções de ferro, manganês e sulfeto de hidrogênio foram de 92%; 59% e 94% (pH 7), e 93%; 74% e 100% (pH 8,0), respectivamente. No caso da relação estequiométrica, as reduções foram maiores quando foi usada a relação estequiométrica de 1,0 e pH 8,0 (89% para Mn e 95% para Fe). O protótipo de torre de dessorção, localizado na ETA Lomba do Sabão, foi operado com razões ar:água de 8 e 12 m3:m3. As remoções de ferro variaram entre 14% a 31%; para manganês, não houve redução aparente. As concentrações efluentes de sulfeto de hidrogênio foram inferiores ao limite de detecção do método analítico, mostrando que houve volatilização do gás neste processo. O protótipo do sistema de membranas de nanofiltração foi também instalado na ETA Lomba do Sabão. Foram realizados ensaios com vazões de 2 e 4 L∙min-1, correspondentes a taxas de aplicação de 14 e 28 L∙h-1∙m-2 a 25°C. As rejeições da membrana para a taxa de 14 L∙h-1∙m-2 foram de 91%, 96% e 100% (<LD) para ferro, manganês e sulfeto de hidrogênio, respectivamente; para a taxa de 28 L∙h-1∙m-2 as reduções foram de 89%, 92% e 100%. Os três processos mostraram ser efetivos para remover sulfeto de hidrogênio. A dessorção foi particularmente ineficiente na redução de Mn(II), ao contrário da oxidação com permanganato, onde a remoção atingiu cerca de 75% ao pH 8,0. A nanofiltração, nos ensaios realizados, atingiu os maiores valores de redução dos compostos estudados. Many regions in Brazil have problems associated with the water quality of their supplies, which bring problems to the production of safe drinking water that is distributed in communities. Generally, consumers judge the drinking water safety through the use of their organoleptic senses. The conventional processes used in water treatment are not effective to remove many compounds that cause color, taste and odor in water. For this reason water utilities frequently receive complaints by angry consumers unsatisfied with the quality of drinking water. Among the compounds that cause taste, odor and color in drinking water are hydrogen sulfide, iron and manganese. Sulfide generates a "rotten egg" smell, perceptible at concentrations between 0.05 and 0.1 mg·L-1. Manganese and iron are mainly associated with the formation of color and precipitates in water. The objective of this research was to study alternative treatment technologies to remove hydrogen sulfide, iron and manganese from drinking water. The investigated processes were air-stripping, nanofiltration and oxidation with potassium permanganate. Air stripping and nanofiltration pilot plants were supplied with water from Lomba do Sabão reservoir, located in Porto Alegre. Potassium permanganate oxidation was studied in laboratory using Jar tests systems and water from Lomba do Sabão. Oxidation tests associated with chemical clarification were performed in four different phases. In the first, the coagulants ferric chloride and aluminum sulfate were tested, with preparation of coagulation diagrams. In the second phase, it was measured the removal of Fe(II), Mn(II) and H2S during chemical clarification. The water oxidation demand was tested in the third experimental phase. Finally, the fourth phase encompassed tests using potassium permanganate associated with chemical clarification for the removal of Fe(II), Mn(II) and H2S. The results demonstrated that coagulation removed iron efficiently, but not manganese. Using permanganate, reductions in iron, manganese and sulfide increased to 92%, 59% and 94% (pH 7,0), and 93%, 74% and 100% (pH 8,0), respectively. Higher removals were achieved at pH 8,0 and one time the compounds stoichiometric oxidation relation. The air-stripping tower prototype was located at the Lomba do Sabão Water Treatment Plant. It operated with air to water ratios between of 8 and 12 m3:m3. Iron removal rates varied from 14% to 31%, while there were no removal for manganese. Hydrogen sulfide concentrations in plant’s effluents were below the detection level, showing full volatilization of the gas during stripping. The nanofiltration system prototype was also installed at Lomba do Sabão Water Treatment Plant. Tests were performed using flowrates of 2 and 4 L·min-1, corresponding to hydraulic application rates of 14 e 28 L∙h-1∙m-2 a 25°C. The rejections for the 14 L∙h-1∙m-2 tests were 91%, 96% and 100% (<LD) for iron, manganese and sulfide, respectively; for 28 L∙h-1∙m-2, the reductions achieved 89%, 92%, and 100%. The tested treatment processes were effective for hydrogen sulfide removal. Air-stripping was particularly inefficient for Mn(II) removal; on the contrary, permanganate oxidation reached 75% at pH 8,0. Tests with nanofiltration reached the highest removal rates for the studied compounds.

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Fiorentino, Nicole Marie. "Assessment of iron bioavailability and protein quality of new fortified blended foods in broiler chickens." Thesis, Kansas State University, 2017. http://hdl.handle.net/2097/35497.

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Master of Science Department of Food, Nutrition, Dietetics, and Health Brian L. Lindshield Fortified-blended foods (FBFs), grain-legume porridges (most commonly corn and soy), are frequently used for food aid purposes. Sorghum and cowpea have been suggested as alternative FBF commodities because they are drought-tolerant, grown locally in food aid receiving countries, and are not genetically modified. The objective of this thesis was to determine the protein quality and iron bioavailability of newly formulated, extruded FBFs in broiler chickens, which have been suggested as a good model for assessing iron bioavailability. Five FBFs were formulated to contain whey or soy protein to compare protein quality, sugar, oil, and an improved micronutrient premix. These included three white sorghum-cowpea FBFs; two were extruded with either whey protein concentrate (WSC) or soy protein isolate (WSC+SPI) added, one was non-extruded (N-WSC). Two others were white sorghum-soy (WSS) and corn-soy (CSB14) FBFs. Two additional white-sorghum cowpea FBFs were reformulated and “over-processed” to contain no sugar, less whey (O-WSC) or soy protein (O-WSC+SPI), and less oil, thus producing a less expensive FBF. Two studies were performed using prepared (Prep) or dry (Dry) FBFs, along with the United States Agency for International Development (USAID) corn and soy blend FBF, CSB+, fed to chickens for 3 and 2 weeks, respectively; food intake, body weights, hemoglobin, and hepatic iron were assessed. In the Prep study, new FBFs significantly increased caloric and protein efficiency compared to CSB+, despite similar food intake and body weight gain. In the Dry study, CSB+ significantly decreased food intake and caloric efficiency, with the exception of O-WSC+SPI, and nonsignificantly reduced body weight gain and protein efficiency compared to new FBFs. CSB+ significantly reduced hepatic iron content compared to all FBFs in the Dry study, and was nonsignificantly decreased compared to new FBFs in the Prep study. In conclusion, sorghum and cowpea FBFs performed similarly to corn and soy FBFs, suggesting these commodities are suitable replacements for corn and soy. Soy protein isolate (WSC+SPI) was an effective alternative to whey protein concentrate (WSC), suggesting SPI can be a less expensive protein supplement in FBFs. Surprisingly, non-extruded sorghum and cowpea (N-WSC) was equally efficacious to extruded WSC. However, N-WSC did not meet viscosity requirements and is not precooked, which limits its viability as an FBF. O-WSC+SPI resulted in poorer outcomes compared to other FBFs, which suggests the protein quality of cowpea may be inferior and the inclusion of whey protein is needed in this formulation, as O-WSC with whey performed similarly to other FBFs. Overall, new FBFs, with the exception of O-WSC+SPI, resulted in improved food efficiency and hepatic iron outcomes compared to CSB+, suggesting they are of higher nutritional quality. However, further research is needed to refine and identify the best FBF formulations.

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Doorsian, Mona. "The Effect of Iron Status during Pregnancy on Hearing Functions in the Newborn." Thesis, Université d'Ottawa / University of Ottawa, 2017. http://hdl.handle.net/10393/36486.

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Background: Iron deficiency, anemia, and iron excess have been associated with altered hearing functions in children and adults. Animal studies suggest that iron deficiency during pregnancy negatively affect fetal auditory development. The relationship between maternal iron status and auditory functions in healthy term newborns has not been clearly elucidated among humans. The goal of this pilot study was to determine the relationship between markers of iron status during pregnancy and brainstem auditory function in healthy neonates. Methods: Pregnant women who gave birth at the Montfort Hospital were recruited to take part in this study (n=6). Within two weeks after birth, their newborn’s hearing function was assessed by wave amplitude, latency and inter-latency from the Auditory Brainstem Response (ABR) test. Markers of iron status, namely hemoglobin (Hb) and mean corpuscular volume (MCV), were collected retrospectively for the first and second trimester from the women’s medical chart. Results: Overall, no significant relationship was observed between maternal Hb and MCV concentrations and newborns auditory function. Although two significant Spearman correlations were observed (MCV and inter-latency I-V; r=0.87; p=0.005 and Hb and amplitude V; r=0.89; p=0.04), these findings may be due to chance because of multiple testing and the small sample size. Conclusion: Although iron is a key nutrient involved in the brain and auditory system development, we were not able to demonstrate a relationship between iron status during pregnancy and newborn hearing function. Prospective or intervention studies with a larger sample size and with more specific iron markers (ex. ferritin) are required to confirm these findings.

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Delimont, Nicole Marie. "Factors affecting food aid: evaluating new fortified-blended foods and the clinical impact of tannin and phytic acid consumption on iron bioavailability." Diss., Kansas State University, 2017. http://hdl.handle.net/2097/35374.

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Doctor of Philosophy Department of Food, Nutrition, Dietetics, and Health Brian L. Lindshield Iron, vitamin A, and protein inadequacies are common in food-aid receiving countries, and maximizing nutrient intake and bioavailability are essential treatments. Fortified-blended foods (FBFs), are food-aid micronutrient-fortified legume-grain porridges distributed worldwide. FBFs have not consistently, effectively treated undernutrition, and it has been suggested that formulation and processing changes could improve their nutritional quality. Sorghum is a well suited FBF commodity, but high concentrations of ‘antinutritional’ tannin and phytic acid have limited its adoption. Iron bioavailability adaptation may be possible after long-term antinutritional factor consumption, but adaptive mechanisms are not well understood. In rats, salivary proline-rich proteins (PRPs) have been found to chelate tannins to improve iron bioavailability, this could be true for people as well. Several research design methods were employed to summarize FBF quality outcomes and the effect of tannin and phytic acid consumption on iron bioavailability. Extruded sorghum and corn FBFs were developed; protein quality, iron, and vitamin A outcomes were compared with a non-extruded corn-soy blend (CSB+) in rats. A narrative literature review and meta-analysis were conducted to determine tannin’s antinutritional effects on iron bioavailability, and the potential for adaptation through salivary PRPs. Two clinical trials examined the effect of long-term tannin or phytic acid consumption on iron bioavailability, salivary protein production, and correlations between PRPs and iron bioavailability. There were no differences between iron (hepatic iron 207-300 µmol/g *100), vitamin A (hepatic retinol 423-585.5 ng/mg), or protein quality (caloric efficiency: 101.3-113.3 g/kcal*100) between extruded FBFs regardless of commodity in rats. Compared to extruded FBFs, CSB+ caloric efficiency (49.0 ± 2.2 g/kcal*100) and growth (96.3 ± 3.4g vs. 208.6-236.6) were significantly reduced. A literature review suggested that there were differences in acute meal and long-term iron bioavailability with tannin consumption; tannic acid inhibited iron availability, while food-tannins did not. Meta-analysis suggested that tannin-PRP binding could protect iron bioavailability, that long-term tannin consumption did not significantly affect hepatic iron or non-heme iron absorption respectively in rats (d = -0.64-1.84; -2.7-0.13), and that PRP expression in rats during tannin consumption was correlated with improved iron bioavailability. There were no reductions in iron bioavailability or status based on long-term tannin (ps > 0.126) or phytic acid (ps > 0.08) consumption clinically, but basic PRP and cystatin subtypes were significantly correlated with improved iron bioavailability during tannin (ps < 0.03) and phytic acid (ps < 0.02) consumption. In vitro, it phytic acid-PRP binding did not occur, but phytic acid did specifically bind with cystatin SN, a non-enzymatic salivary protein. In conclusion, FBF formulation changes may improve protein quality, and provide needed macronutrients to food-aid receiving areas. Despite this, this research did not suggest that antinutritional factors affected iron bioavailability. In support of this finding, literature, and clinical studies presented here suggest that salivary proteins, including PRPs and cystatin, may serve as adaptive protective mechanisms against phytic acid and tannin consumption, and that further research may be warranted before further recommendations for their removal from food-aid are made.

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Neitzke, Thaís Luft da Silva. "Agrupamento de rizobactérias nativas da região oeste do Paraná por estudo de congruência genética e bioquímica." Universidade Estadual do Oeste do Paraná, 2018. http://tede.unioeste.br/handle/tede/3877.

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Submitted by Rosangela Silva (rosangela.silva3@unioeste.br) on 2018-08-21T18:43:09Z No. of bitstreams: 2 Thaís Luft da Silva Neitzke.pdf: 946176 bytes, checksum: 7f73bad9b6143ec1effc7bfee257ab65 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Made available in DSpace on 2018-08-21T18:43:09Z (GMT). No. of bitstreams: 2 Thaís Luft da Silva Neitzke.pdf: 946176 bytes, checksum: 7f73bad9b6143ec1effc7bfee257ab65 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-04-20 Fundação Araucária de Apoio ao Desenvolvimento Científico e Tecnológico do Estado do Paraná (FA) In the search for agronomic alternatives that are less aggressive to the environment, the substitution of mineral fertilizers by biofertilizers based on plant-beneficial micro-organisms was initiated, among them plant growth promoting bacteria. The objective of this work was to characterize rhizobacteria isolated from soils with different crop managements, grouping the samples based on their genetic characteristics (16S rDNA sequencing, amplification of the ITS 16–23S rDNA region, feoB, entC and entF genes) and biochemical (indole-acetic acid (IAA) production, acetoin production and phosphate solubilization), and verify their diversity within groups. Based on the results, the presence of the genes feoB, entF and entC was verified in 81.5%, 48.1% and 81.5% of the samples, respectively. Most of the strains (96.3%) had the capacity to produce IAA, 59.2% were able to produce acetoin and 81.5% of them to solubilize phosphate. By the analysis of congruence and grouping, there was similarity of genetic or biochemical patterns between the groups; however, there was great diversity among the isolates within each group. In general, it was observed that the conservationist managements presented the best performances. The study revealed that strains 130, 219, 302 and 326 presented biotechnological potential for at least two of the characteristics evaluated. Na busca por alternativas agronômicas que sejam menos agressivas ao meio ambiente, iniciou-se a substituição do fertilizante mineral por biofertilizante a base de microrganismos benéficos às plantas, entre estes as bactérias promotoras do crescimento vegetal. O objetivo deste trabalho foi caracterizar rizobactérias isoladas de solos com diferentes manejos de cultivo, agrupando as amostras com base em suas características genéticas (sequenciamento 16S rDNA, amplificação da região ITS 16-23S rDNA, genes feoB, entC e entF) e bioquímicas (produção de ácido-indol-acético (AIA), produção de acetoína e solubilização de fosfato), e verificar a sua diversidade dentro dos grupos. Baseado nos resultados, foi verificada a presença do gene feoB, entC e entF em 81,5%,48,1% e 81,5% das amostras, respectivamente. A maioria (96,3%) das estirpes apresentou a capacidade de produzir AIA, 59,2% foi capaz de produzir acetoína e 81,5% delas à solubilizar fosfato. Pela análise de congruência e agrupamento, verificou-se semelhança de padrões genéticos ou bioquímicos entre os grupos, no entanto, apresentaram grande diversidade entre os isolados dentro de cada grupo. De forma geral, observou-se que os manejos conservacionistas apresentaram os melhores desempenhos. O estudo revelou que as estirpes 130, 219, 302 e 326 apresentaram potencial biotecnológico para pelo menos duas das características avaliadas.

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32

Tato, L. M. "INTEGRATED RESPONSES OF A WILD SPECIES PARIETARIA JUDAICA (L. 1753) TO DIRECT AND INDUCED IRON DEFICIENCY GROWTH CONDITIONS." Doctoral thesis, Università degli Studi di Milano, 2013. http://hdl.handle.net/2434/218168.

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Iron (Fe) is an essential micronutrient in plants as it takes part in major metabolic pathways such as photosynthesis and respiration and is linked to many enzymes that accomplish many other cellular functions (DNA synthesis, nitrogen fixation, hormone production). Fe deficiency, a major abiotic stress, reduces crop yields, especially in calcareous soils in which the solubility of Fe is extremely low because of the high soil pH. Parietaria judaica is a wild sinantropic Strategy I plant that implements many integrated mechanisms allowing to successfully complete the life cycle in highly calcareous environments. In this work the main mechanisms by which P. judaica overcomes the low bioavailability of Fe have been identified. P. judaica was subject to direct and induced Fe deficiency growth conditions in hydroponic systems. Strategy I biochemical mechanisms of FeII-reduction and rhizosphere acidification were studied, as well as low organic acids and phenolics in root exudates. It was suggested that the accumulation and exudation of phenolic compounds plays a central role in the adaptive strategy of P. judaica to cope with Fe deficiency conditions. Key enzymes of primary and secondary metabolism were assayed in order to identify the metabolic rearrangement that occurs under Fe deficiency conditions. The data analysed confirm that under Fe deficiency the metabolic rearrangement takes place by modifying allocation of carbon skeletons between primary and secondary metabolism. It was observed that secondary metabolism constitutes the main concern under this stress condition as P. judaica sustains the supply of substrates using non oxidative ways. Phenolic composition was characterized by HPLC analyses in P. judaica focusing on phenolic composition changes due to low Fe availability. Phenolic compounds found in P. judaica belong mainly to the mono- and di- caffeoylchinic acids group. The chlorogenic acid was resulted the most sensible component under Fe deficiency stress. Morphological and architectural modifications of root system were also analysed. P. judaica changes its root system according to the experimental treatment imposed. The differences found in direct and induced Fe-Deficiency conditions were oriented to increase the root contact surface with the medium. In particular, the root architecture reflected the plant nutritional status. Comparing the data obtained from high bicarbonate and highly alkaline buffer conditions it was observed that P. judaica has no problems to acquire Fe in highly alkaline environments, suggesting that in a highly chalky environment the availability of bicarbonate itself constitutes the real factor of stress.

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33

Maleki, Heidar, Armin Sorooshian, Gholamreza Goudarzi, Amirhossein Nikfal, and Mohammad Mehdi Baneshi. "Temporal profile of PM10 and associated health effects in one of the most polluted cities of the world (Ahvaz, Iran) between 2009 and 2014." ELSEVIER SCI LTD, 2016. http://hdl.handle.net/10150/621554.

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Ahvaz, Iran ranks as the most polluted city of the world in terms of PM10 concentrations that lead to deleterious effects on its inhabitants. This study examines diurnal, weekly, monthly and annual fluctuations of PM10 between 2009 and 2014 in Ahvaz. Health effects of PM10 levels are also assessed using the World Health Organization AirQ software. Over the study period, the mean PM10 level in Ahvaz was 249.5 mu g m(-3), with maximum and minimum values in July (420.5 mu g m(-3)) and January (154.6 mu g m(-3)), respectively. The cumulative diurnal PM10 profile exhibits a dominant peak between 08:00-11:00 (local time) with the lowest levels in the afternoon hours. While weekend PM10 levels are not significantly reduced as compared to weekdays, an anthropogenic signature is instead observed diurnally on weekdays, which exhibit higher PM10 levels between 07:00-17:00 by an average amount of 14.2 mu g m(-3) as compared to weekend days. PMio has shown a steady mean-annual decline between 2009 (315.2 mu g m(-3)) and 2014 (143.5 mu g m(-3)). The AirQ model predicts that mortality was a health outcome for a total of 3777 individuals between 2009 and 2014 (i.e., 630 per year). The results of this study motivate more aggressive strategies in Ahvaz and similarly polluted desert cities to reduce the health effects of the enormous ambient aerosol concentrations. (C) 2016 Elsevier B.V. All rights reserved.

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34

Spahic, Edna. "Three-dimensional modelling of the Källfallsgruvan iron oxide deposit, Riddarhyttan ore field, Bergslagen, Sweden: Integrating existing and new data to aid understanding of structural controls and mineral exploration." Thesis, Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-86083.

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The Bergslagen ore province, located in the Fennoscandian shield in the south-central part of Sweden hosts several metallic mineral deposits, one of them being the Källfallsgruvan iron-oxide deposit in the Riddarhyttan ore field, situated in a high-strain shear belt denoted as the West Bergslagen Boundary Zone (WBBZ). An accurate 3D geological model of the Källfallsgruvan iron-oxide deposit has been generated to aid understanding of the ore body geometries and calculating volume and tonnage. The methodology of this study consisted of assessing existing data in the form of legacy mine maps and to integrate new data from field work, drill core logging and 3D geological modelling. The work has resulted in structural interpretations that are put in the context of the regional structural framework in Bergslagen consisting of three deformation events (D1, D2 and D3) and two metamorphic events (M1 and M2). The field work resulted in six rock units being defined used to construct a geological map, in addition the structural measurements resulted in a hypothetical semi-regional fold and evidence of ductile strike-slip/dip-slip shearing. Logging of drill cores resulted in three rock units being defined, two of them related to the mineralization and one characterizing the host rock (± local variations), correlating to the observed host rock from the field work. The rock units discovered from both the field work and drill core logging are all interpreted to be the metamorphic products of volcanic rocks subjected to alteration of varying degree. Based upon geological field observations with subsurface data and 3D geological modelling it is concluded that, 1) The deposit comprises multiple ore bodies that jointly resemble an S-shaped synform that is steeply inclined-upright, moderately-steeply plunging towards the southwest with an axial plane striking northeast-southwest. The deposit is interpreted to be geometrically controlled by an F2 fold, possibly displaying an interference pattern of type 1, favouring progressive shearing and deformation solely related to D2, 2) Evidence of at least one generation of transpressional tectonic regime exists, interpreted to be D2, 3) The estimated tonnage of 4 938 610 tons of the massive magnetite and semi-massive mineralization revealed that a deposit of such tonnage is presently not economically viable. However, if the Källfallsgruvan iron-oxide deposit or similar is determined to have a significant REE content, such deposit may then be of economic interest and, 4) Possible mineral exploration indicators around Källfalls-like deposits are intensely altered rocks related to magnesium alteration, consisting dominantly of quartz, biotite (increasing towards mineralization), muscovite, chlorite, anthophyllite and cordierite, affected by parasitic folding. Bergslagen malmprovins, belägen i den Fennoskandiska skölden i sydcentrala delen av Sverige innehåller flera metall mineralfyndigheter, varav en av dem är Källfallsgruvan järnoxidfyndighet i Riddarhyttan malmfält, belägen i en skjuvzon kallat för ”West Bergslagen Boundary Zone (WBBZ)”. En representativ 3D geologisk model av Källfallsgruvan järnoxidfyndighet har genererats för att öka förståelsen av malmkroppens geometrier samt beräkna volym och tonnage. Metodiken bestod av att bedöma existerande data så som gruvkartor och integrera nya data genom fältarbete, borrkärnekartering och 3D geologisk modellering. Arbetet resulterade i strukturella tolkningar som sattes i kontexten av den regionala strukturella bilden i Bergslagen bestående av tre deformations event (D1, D2 och D3) och två metamorfa event (M1 och M2). Fältarbetet resulterade i att sex bergartsenheter definierades som användes för att konstruera en geologisk karta samt så har de strukturella mätningarna resulterat i ett hypotetiskt semi-regionalt veck och bevis för duktil strike-slip-/normal-skjuvning. Borrkärnekarteringen resulterade i att tre bergartsenheter definierades, varav två var relaterade till mineraliseringen och en kännetecknade värdbergarten (± lokala variationer) som korrelerar med den observerade värdbergarten från fältarbetet. Bergartsenheterna som upptäcktes från både fältarbetet och borrkärnekarteringen har tolkats vara metamorfa produkter av vulkaniska bergarter som omvandlats i varierande grad. Baserat på de geologiska fältobservationerna med underjordsdata och 3D geologisk modellering dras följande slutsatser, 1) Fyndigheten består av multipla malmkroppar som gemensamt liknar en S-formad synform som är brant lutande-upprätt, måttligt-brant stupande mot sydväst med ett axialplan som stryker nordost-sydväst. Fyndigheten tolkas vara geometriskt kontrollerat av ett F2 veck, som möjligtvis påvisar ett interferensmönster av typ 1 bildat genom progressiv skjuvning och deformation endast relaterat till D2, 2) Bevis för minst en generation av transpressionstektonisk miljö existerar vilket tolkats vara D2, 3) Det estimerade tonnaget på 4 938 610 ton för den massiva magnetit och semi-massiva mineraliseringen visade att en fyndighet av sådant tonnage är för nuvarande inte ekonomiskt hållbart. Om Källfallsgruvan järnoxidfyndighet eller liknande fyndighet bestäms att ha ett betydande REE innehåll så skulle en sådan fyndighet vara av ekonomiskt intresse och, 4) Möjliga prospekteringsindikatorer runt Källfalls-liknande fyndigheter är intensivt omvandlade bergarter relaterad till magnesiumomvandling främst bestående av kvarts, biotit (ökar mot mineraliseringen), muskovit, klorit, antofyllit och kordierit, påverkad av parasitisk veckning.

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Garlitz, Richard P. "Academic Ambassadors in the Middle East: The University Contract Program in Turkey and Iran, 1950-1970." Ohio : Ohio University, 2008. http://www.ohiolink.edu/etd/view.cgi?ohiou1224727953.

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Deladerriere, Loup. "De la gouvernance de l'air aux transformations socio-urbaines à Téhéran et à Mexico." Electronic Thesis or Diss., Paris, EHESS, 2024. http://www.theses.fr/2024EHES0018.

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Cette thèse propose d’interroger l’évolution de la gouvernance de l’environnement et des sociétés à partir de l’étude des politiques de lutte contre la pollution atmosphérique à Téhéran et à Mexico. Si la pollution de l’air représente un problème de santé publique majeur (4,2 millions de décès prématurés en 2019 selon l’OMS), son exposition et ses conséquences sont inégalement réparties. Au Mexique comme en Iran, l’institutionnalisation de ce problème sanitaire, environnemental, social et politique soulève de nombreux problèmes de gouvernance qui renouvellent les inégalités spatiales et socio-environnementales entre les centres et les périphéries. La mise en place de lois, normes, outils et restrictions transforment également l’urbain et questionnent l’évolution du Droit à la ville. Les enjeux environnementaux offrent enfin de nouveaux arguments aux autorités pour intervenir sur l’urbain et en reprendre le contrôle - ce qui soulève des résistances protéiformes. Les problématiques environnementales interrogent non seulement les questions d’égalité et de justice mais aussi de démocratie et de liberté This thesis examines the evolution of environmental and social governance through the study of air pollution control policies in Tehran and Mexico City. While air pollution represents a major public health problem (4.2 million premature deaths in 2019 according to the WHO), its exposure and consequences are unevenly distributed. In Mexico, as in Iran, the institutionalization of this health, environmental, social and political problem raises numerous governance issues that renew spatial and socio-environmental inequalities between centers and peripheries. The implementation of laws, standards, tools and restrictions is also transforming the urban environment, and calling into question the evolution of the Right to the City. Finally, environmental issues offer new arguments for authorities to intervene in the urban environment and regain control of it - a move that raises protean resistance. It's not just a question of equality and justice, but also of democracy and freedom, that environmental issues seem to raise

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Safavizadeh, Nazanin. "L'imaginaire des quatre éléments dans la littérature contemporaine : analyse comparée à travers Goli Taraghi et Jean Marie Gustave Le Clézio." Thesis, Lyon 2, 2014. http://www.theses.fr/2014LYO20050.

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Cette thèse porte sur l'imaginaire des quatre éléments à travers la littérature comparée contemporaine, entre un auteur français, Jean-Marie Gustave Le Clézio et une auteure iranienne, Goli Taraghi. La méthodologie engagée révèle à partir des qualités sensibles propres à chaque élément, des caractères symboliques. La littérature comparée exige d'autre part, d'appréhender notre sujet avec une vision élargie aux faits culturels et sociétaux car chaque auteur porte dans son imaginaire de la nature, une mémoire à la fois personnelle et collective. Cette mémoire est en effet traversée par des événements historiques particuliers qui ont une influence certaine sur la psychologie individuelle et le rapport au monde. La part du souvenir et l'interprétation du souvenir sont par conséquent attentivement observées et nous suivons ainsi le cours que l'auteur a aménagé à chaque élément, dans l'écriture de son monde. L’étude se compose de trois parties : les première et deuxième parties concernent les domaines sensible et symbolique. La troisième partie confronte les résultats obtenus en mettant en évidence des réseaux thématiques d'images et de symboles. Enfin, la conclusion nous amène à souligner l'importance de la psychologie de chaque auteur qui délimite ainsi un territoire d'exercice pour chaque élément, ébauchant une cosmogonie dont les quatre éléments ne présentent qu'un aspect. Ce qui fait l'intérêt de l'analyse dans la littérature comparée se révèle ici riche de sens en permettant l'émergence des différences et des éléments d'universalité par-delà l'érosion que produit la mondialisation de la post-modernité. L'écrivain montre une certaine indépendance par la persistance d'attitudes singulières animées par la vigueur de l'enracinement culturel This thesis focuses upon the imagination of the four elements through contemporary comperative literature, between French writer Jean-Marie Gustave Le Clezio and Iranian writer Goli Taraqi. The methodology used here reveals symbolic characters from the sensitive qualities of each element. On the other hand, compared literature requires that we understand our subject with a more expanded vision based on cultural and societal facts because each writer carries in his/her own imagination of the nature at times a personal and collective memory. This memory is in fact crossed by particular historic events which have a specific influence on individual psychology and relation with the world. The share of memories and the interpretation of memories are attentively observed and we follow the way the writer has designed for each element in writing his world. This study is comprised of three parts: The first and the second parts are about sensitive and symbolic areas and the third part compares the results obtained from exposing the thematic networks of images and symbols. Finally, the conclusion brings us to underscore the importance of psychology of each writer, which determines a territory of action for each element by outlining a cosmogony whose four elements represent only a single aspect. The advantage with analysis in the compared literature here is that the latter is rich in meaning, allowing the emergence of differences and elements of universality beyond erosion resulting from the globalization of post-modernity. The writer shows a sort of independence through persistence of specific lively attitudes through the vigor of cultural roots

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PROIETTI, ILARIA. "Impatto di processi alimentari tradizionali sulle attività biologiche di tannini e acido fitico nel porridge di sorgo: approccio integrato in vitro e analitico." Doctoral thesis, Università Cattolica del Sacro Cuore, 2013. http://hdl.handle.net/10280/1746.

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Cinque varietà di sorgo (Sorghum bicolor (L.) Moench) provenienti da Nigeria, Senegal, Burkina Faso e due dall’Italia, sono state caratterizzate per il loro profilo nutrizionale, analizzando la modulazione di due marcatori cellulari (contenuto in proteine totali e attività della GPx), il contenuto di fattori chelanti (tannini e fitati), l’attività fitasica e il contenuto, la bioaccessibilità e la biodisponibilità di ferro e zinco e analizzando l’impatto di due importanti processi alimentari, quali fermentazione e cottura. I risultati mostrano che sia la varietà sia il processo influenzano la maggior parte dei parametri. Tannini e fitati, elementi in traccia, contenuto proteico totale e il processo (soprattutto la fermentazione) sono modulati dalla varietà. La fermentazione riduce il contenuto di fattori chelanti e aumenta l’attività fitasica, incrementando, così, la biodisponibilità degli elementi in traccia; mentre la cottura non ha un impatto significativo. D’altra parte, la fermentazione ha un impatto negativo su entrambi i marcatori cellulari, mentre la cottura solo sul contenuto proteico totale. Le varietà africane, soprattutto quella dal Senegal, hanno mostrato il migliore profilo nutrizionale, mentre, globalmente, le italiane il peggiore. I risultati indicano che la selezione di varietà e di adeguati processi alimentari può avere un impatto significativo sul valore nutrizionale del sorgo. Five sorghum cultivars (Sorghum bicolor (L.) Moench) from Nigeria, Senegal, Burkina Faso and Italy (two), were characterized for their nutritional values by analysing the modulation of cellular functional markers (total protein content and GPx activity), chelating factors (iron-binding phenolic groups and phytates) content and phytase activity, as well as iron and zinc content, bioaccessibility and bioavailability, also considering the impact of food processing methods as fermentation and cooking. The results revealed that both variety and food processing affect most of the tested parameters. Chelating factors, trace elements, cellular total protein content, as well as the effect of processing (mainly fermentation) were modulated by variety. Fermentation decreased chelating factors content, as well as increased phytase activity, leading to enhancement of iron and zinc estimated bioavailability, whereas cooking had no substantial impact. On the other hand, fermentation process had a negative impact on both cellular functional markers while cooking only on the cellular total protein content. The African varieties, particularly the Senegal one, showed the most promising nutritional profile, whereas the two Italian varieties overall showed a poor one. The results indicate that selection of traditional varieties and processing methods can have a significant impact on parameters relevant to sorghum nutritional value.

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39

PROIETTI, ILARIA. "Impatto di processi alimentari tradizionali sulle attività biologiche di tannini e acido fitico nel porridge di sorgo: approccio integrato in vitro e analitico." Doctoral thesis, Università Cattolica del Sacro Cuore, 2013. http://hdl.handle.net/10280/1746.

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Cinque varietà di sorgo (Sorghum bicolor (L.) Moench) provenienti da Nigeria, Senegal, Burkina Faso e due dall’Italia, sono state caratterizzate per il loro profilo nutrizionale, analizzando la modulazione di due marcatori cellulari (contenuto in proteine totali e attività della GPx), il contenuto di fattori chelanti (tannini e fitati), l’attività fitasica e il contenuto, la bioaccessibilità e la biodisponibilità di ferro e zinco e analizzando l’impatto di due importanti processi alimentari, quali fermentazione e cottura. I risultati mostrano che sia la varietà sia il processo influenzano la maggior parte dei parametri. Tannini e fitati, elementi in traccia, contenuto proteico totale e il processo (soprattutto la fermentazione) sono modulati dalla varietà. La fermentazione riduce il contenuto di fattori chelanti e aumenta l’attività fitasica, incrementando, così, la biodisponibilità degli elementi in traccia; mentre la cottura non ha un impatto significativo. D’altra parte, la fermentazione ha un impatto negativo su entrambi i marcatori cellulari, mentre la cottura solo sul contenuto proteico totale. Le varietà africane, soprattutto quella dal Senegal, hanno mostrato il migliore profilo nutrizionale, mentre, globalmente, le italiane il peggiore. I risultati indicano che la selezione di varietà e di adeguati processi alimentari può avere un impatto significativo sul valore nutrizionale del sorgo. Five sorghum cultivars (Sorghum bicolor (L.) Moench) from Nigeria, Senegal, Burkina Faso and Italy (two), were characterized for their nutritional values by analysing the modulation of cellular functional markers (total protein content and GPx activity), chelating factors (iron-binding phenolic groups and phytates) content and phytase activity, as well as iron and zinc content, bioaccessibility and bioavailability, also considering the impact of food processing methods as fermentation and cooking. The results revealed that both variety and food processing affect most of the tested parameters. Chelating factors, trace elements, cellular total protein content, as well as the effect of processing (mainly fermentation) were modulated by variety. Fermentation decreased chelating factors content, as well as increased phytase activity, leading to enhancement of iron and zinc estimated bioavailability, whereas cooking had no substantial impact. On the other hand, fermentation process had a negative impact on both cellular functional markers while cooking only on the cellular total protein content. The African varieties, particularly the Senegal one, showed the most promising nutritional profile, whereas the two Italian varieties overall showed a poor one. The results indicate that selection of traditional varieties and processing methods can have a significant impact on parameters relevant to sorghum nutritional value.

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BENMANSOUR-BEKHTI, FATIMA. "Interfacage d'un potentiostat avec un micro-ordinateur en vue de la mesure des impedances electrochimiques." Université Louis Pasteur (Strasbourg) (1971-2008), 1989. http://www.theses.fr/1989STR13076.

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XIE, JIA-FENG, and 謝嘉峰. "Iron-57 M ssbauer studies of environmental materials-soils and air born particulates." Thesis, 1986. http://ndltd.ncl.edu.tw/handle/25515166395738170727.

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42

Ramalope, Deborah. "Air pollution control measures implemented by the South African iron and steel industries." Thesis, 2014. http://hdl.handle.net/10210/9967.

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M.Sc. (Environmental Management) With the rapid expansion of the industries in South Africa, environmental problems including air pollution have been increasing. Among industries that cause air pollution is the iron and steel industry. Air pollution impacts negatively on the environment and therefore the measures implemented to improve air quality by this industry were investigated. The purpose of this thesis was to critically analyse the air pollution control measures implemented by the iron and steel industry in South Africa and to find out what they are doing to address the problem of air pollution, as well as their processes in involving and encouraging community involvement with regard to environmental issues. The key findings from this study were that the South African iron and steel companies are doing their best in trying to control the problem of air pollution. Some of them do not only rely on the South African legislation, they also do self-regulation by monitoring and controlling the air pollution problems even if not strictly required to by legislation. The iron and steel industry does also involve communities, through participation in public environmental forums. Air pollution has always been an issue in South Africa, but due to a lack of enabling legislation in the country, many people were not aware of their environmental rights. Now that the South African Constitution highlights the rights of people to an environment that is not harmful to their health or wellbeing, people are becoming more aware and have started taking the issue of air pollution in a very serious light. With the new environmental legislation including the National Environmental Management Act 108 of 1009 and the National Environmental Management: Air Quality Bill (Draft 1, April 2003), most of the issues relating to air pollution will be dealt with in a better and more enforceable way.

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Jagathlal, Sham. "Assessing the PM10 footprint of an iron and steel plant on ambient air quality : modelling PM10 emissions from the ArcelorMittal Vanderbijlpark Works iron and steel plant." Thesis, 2014.

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Iron and steel plants in general are significant sources of PM10 pollution. Many studies have concluded that PM10 is harmful to human health and well being. ArcelorMittal Vanderbijlpark Works falls within the jurisdiction of the Vaal Triangle Airshed Priority Area (VTAPA) and has been given PM10 reduction targets in the Air Quality Management Plan. The aim of this study is to use dispersion modelling to determine the impact of the Vanderbijlpark Works steel plant on ambient PM10 and to assess the effectiveness of the reduction strategies with respect to PM10 The AERMOD dispersion model was chosen for the exercise because of its reliability when modelling near field dispersions on relatively flat terrain. Meteorological data was obtained from on-site stations. Emissions data was obtained from an already existing emissions inventory on site. The study modelled the PM10 baseline for 2010 and then modelled the predicted concentrations after implementation of the strategies as outlined in the VTAPA. The modeling scenarios were compared to the measured PM10 data from the fence line monitors. The following findings were made: Point sources were not significant contributors to PM10 emission. Modeling of area sources and other fugitive dust sources were found to be high and when compared to measured concentrations were found to be over predicted. It is concluded that the fugitive sources have been found to be the major source of PM10 emissions and that reduction of fugitives should feature prominently in emission reduction plans going forward. In addition, the fugitive emissions inventory needs to be refined to enhance the accuracy of the predictions.

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Tsai, Yi-Ying, and 蔡宜穎. "Nickel iron layered double hydroxide derived bifunctional oxygen electrode catalyst for rechargeable zinc/air batteries." Thesis, 2018. http://ndltd.ncl.edu.tw/handle/qwd872.

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碩士 國立臺灣科技大學 化學工程系 106 In recent years, rechargeable zinc-air batteries have attracted much attention owing to its high energy density, promising safety, and economic viability. In air electrode, bi-functional electrocatalysts are desirable since the dual functionality of the oxygen evolution reaction (OER) and oxygen oxygen reduction reaction (ORR) are required on the same electrode under charging and discharging processes, respectively. Unfortunately, both ORR catalyst Pt/C and OER catalyst IrO2 don’t have bifunctional property. The high cost of precious Pt/C and IrO2 catalysts also limit their wide spread application. In the light of this, this work provides a promising bi-functional electrocatalyst with earth-abundant elements to enable the oxygen conversion reaction efficiently. Carbon supported NiFe layered double hydroxide (NiFe LDH/C) can be synthesized by a facile hydrothermal method which can precisely control the catalyst’s composition. Then, the optimal NiFe LDH/C was used as precursor and further reduced to bi-functional catalyst by hydrogen reduction and thermal ammonolysis. The results show that NiFe/NiFeN/NC nanocomposites, characterized by duel electroactive sites for OER and ORR, can be simultaneously derived by thermal ammonolysis process. According to the electrochemical measurements by linear sweep voltammetry (LSV), NiFe/NiFeN/NC nanocomposite calcined in ammonia at 500 oC demonstrates excellent activities for oxygen conversion reaction, when compared to NiFe LDH and NiFe/C. Its overpotential △E between the ORR current density of 3 mA cm−2 and OER current density of 10 mA cm−2 is 0.91 (V). In the stability test, a chronoamperometry method was used in 0.1 M KOH. After 6 hours, NiFe/NiFeN/NC catalyst calcined at 500 oC showed high stability with a decline of current of 8.9% and 14.1% in OER and ORR, comparable to 29.1% for IrO2 and 7.7% for Pt/C, respectively. In addition, the ORR stability test in 1 M KOH showed that the activity decayed 18.4% for NiFe/NiFeN/NC, whereas 23.1% for Pt/C. This indicates that the composite catalyst is more suitable for operations under harsh environments. This study further attempts to establish a rechargeable zinc-air battery test platform and analyze material performance. NiFe/NiFeN/NC shows good stability and its performance is comparable to that of Pt/C+IrO2, confirming its bi-functional property. Considering the cost and mass production, NiFe/NiFeN/NC offers more advantages than the combination of noble materials with Pt/C and IrO2. Keywords:Alkaline, Bifunctional electrocatalyst, Layered double hydroxide, N-doped carbon, Rechargeable zinc-air battery.

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Wang, Ming-Hsiang, and 王銘詳. "Enhancement of Coagulation of Nonylphenol ethoxylate by Zero-Valent Iron with Oxidants (ZVI/H2O2, O2, Air)." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/7vzu55.

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碩士 國立臺北科技大學 環境工程與管理研究所 99 Metal surface treatment industry employs coagulation to treat wastewater, but in wastewater NP9EO of hydrophilic property made that removal efficiency limited. In order to increase the efficiency of chemical coagulation, it is necessary to increase the NP9EO hydrophobic property. This study used ZVI / H2O2, Air and O2 as a pretreatment before chemical coagulation, and used hydroxyl radical to destroy NP9EO hydrophilic group structures. This study included two stages of experiment. First of all, the ZVI / H2O2, Air or O2 process was used to pretreat NP9EO. Second, the pretreatment sample combined with coagulation by using pretreatment residual iron ionic. In the ZVI / H2O2 pretreatment with different pH, NP9EO could get better removal efficiency when pH was 2（NP9EO 1000 mg / L, ZVI 5 g / L, H2O2 125 mg / L）, NP9EO and TOC removal efficiency were 58.4 % and 25.2 % , respectively. Besides, the ZVI / H2O2 pretreatment result could be using surfer software to get the optimum ZVI / H2O2 dosage which was ZVI 3 g / L – H2O2 125 mg / L. 42.6 % NP9EO and 28 % TOC were removed by using ZVI /Air, nevertheless 47.6 % NP9EO and 34.7 % TOC were removed by ZVI / O2. In addition, through the XAD-8 resin analysis confirmed that pretreatment could increase the hydrophobic nature of NP9EO by destroying NP9EO structural. NP9EO used the Fe2+ that pretreatment residual to apply the process of chemical coagulation after the pretreatment, and the pretreatment optimization was found under ZVI 2.5 g / L – H2O2 125 mg / L ,after total removal efficiency was simulated by the surfer software. Using pretreatment of ZVI / Air, O2 in the process of chemical coagulation, the total NP9EO and TOC removal efficiency were about 47.7% and 28% under aeration of oxygen.

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Jiang, Meng-Yu, and 江孟育. "Growth of nano and micro structures of iron oxides by CO2 laser-heating under air atmosphere." Thesis, 2016. http://ndltd.ncl.edu.tw/handle/39sx67.

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碩士 國立臺灣海洋大學 光電科學研究所 104 In this study, nano and micro structures of iron oxides were successfully grown by CO2 laser-heating under atmosphere, and we analyze their surface morphology through a scanning electron microscope (SEM). We also do elemental analysis for the growth of structure through the energy dispersive spectroscopy (EDS), and then confirm the structure as pure iron oxide. Besides, high-resolution transmission electron microscopy (TEM), Raman spectroscopy, and X-ray diffraction analyzer (XRD) were used to analysis their crystal structures. Nano and micro structures of iron oxides were grown under different laser power and heating time, and the method of heating the bulk iron oxide were divided into two categories. One is heating the bulk surface by laser scanning, and the other is heating the bulk surface by laser pointing heating. Under the method of heating the bulk iron oxide by laser scanning, the heating time is 10 to 20 seconds, and the laser power is 7 to 13 W. After morphology analysis by SEM we found that the main structures are nanoflakes and micro particles. Under the method of heating the bulk iron oxide by laser pointing heating, the heating time is 10 to 15 seconds, and the laser power is 4 to 7 W. After morphology analysis by SEM we found that the main structures are micro column and octahedral structures, and column length is about 11 to 24 microns, column diameter is about 6 to 10 microns. Above nano and micro structures of iron oxides mainly consists of a mixture composed of a-Fe2O3 and Fe3O4. a-Fe2O3 energy gap is 2.1eV, and is an n-type semiconductor material. This material has a magnetic, nontoxic, and anticorrosion properties. Iron oxides have a great advantage in terms of band gap, and applications in lithium battery electrodes, gas sensors, field effect transistors, field emission and so on. Fe3O4 has a cubic inverse spinel structure, it has been widely used as a magnetic fluid and magnetic recording materials, due to their unique electrical and magnetic properties, making it an important magnetite material. Fe3O4 has been used in magnetic ink, electronics and bio-sensitive materials, high-density magnetic recording medium field of medicine and biology. Because their size, shape and the magnetic properties are good compatible with the organism, therefore, the preparation and researching the properties of nano and micro structures of iron oxides are very active in recent years.

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Wong, Zong-Sian, and 翁宗憲. "A Study on High Temperature Oxidation of High Silicon Ductile Iron and High Silicon Cast Steel in Air." Thesis, 2010. http://ndltd.ncl.edu.tw/handle/66364418429437733952.

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碩士 國立臺灣科技大學 機械工程系 98 In this research it is aimed to investigate the high temperature oxidation behavior of high silicon ductile iron and high silicon cast steel in air. The relationship between morphology of oxide layers and internal oxidation of silicon element is studied. Oxidation tests were carried in a furnace at 500, 600, 700, and 800 ℃, respectively; the extent of oxidation was measured by the change of weight of specimen or by the thickness of oxide layers; the microstructure of oxide layers and internal oxidation were examined by OM, SEM, and EDS. The results show that: for high silicon cast steels, the oxidation weight gains decrease with Si content increased, this conforms that the addition of Si will improve the oxidation resistance of steel; the oxidation modes different for high silicon ductile iron to high silicon cast steels, the oxidation behavior of high silicon ductile iron is linear, and high silicon cast steels is toward parabolic; oxidation at 500℃, high silicon ductile iron with 4.71 wt. % has the best oxidation resistance; oxidation at 600 and 700℃, high silicon ductile iron also showed a better resistance in the early stage, but a inferior resistance in the late oxidation. The internal oxidation of Si was not occurred in 500℃, but occurred in temperatures higher than 600 ℃; high silicon cast steels was not observed the internal oxidation of Si at 800℃. As time increasing, the shape of internal oxidation changes from dense to loose, and as temperature increasing, the particles gets thicker. In addition, the internal oxidation layer of high silicon cast steels is more dense and smaller than high silicon ductile iron.

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Kim, Baejung. "Non-Precious Cathode Electrocatalytic Materials for Zinc-Air Battery." Thesis, 2013. http://hdl.handle.net/10012/8102.

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In the past decade, rechargeable batteries attracted the attention from the researchers in search for renewable and sustainable energy sources. Up to date, lithium-ion battery is the most commercialized and has been supplying power to electronic devices and hybrid and electric vehicles. Lithium-ion battery, however, does not satisfy the expectations of ever-increasing energy and power density, which of their limits owes to its intercalation chemistry and the safety.1-2 Therefore, metal-air battery drew much attention as an alternative for its high energy density and a simple cell configuration.1 There are several different types of metal-air batteries that convey different viable reaction mechanisms depending on the anode metals; such as Li, Al, Ca, Cd, and Zn. Redox reactions take place in a metal-air cell regardless of the anode metal; oxidation reaction at the anode and reduction reaction at the air electrode. Between the two reaction, the oxygen reduction reaction (ORR) at the air electrode is the relatively the limiting factor within the overall cell reactions. The sluggish ORR kinetics greatly affects the performance of the battery system in terms of power output, efficiency, and durability. Therefore, researchers have put tremendous efforts in developing highly efficient metal air batteries and fuel cells, especially for high capacity applications such as electric vehicles. Currently, the catalyst with platinum nanoparticles supported on carbon material (Pt-C) is considered to exhibit the best ORR activities. Despite of the admirable electrocatalytic performance, Pt-C suffers from its lack of practicality in commercialization due to their prohibitively high cost and scarcity as of being a precious metal. Thus, there is increasing demand for replacing Pt with more abundant metals due economic feasibility and sustainability of this noble metal.3-5 Two different attitudes are taken for solution. The first approach is by optimizing the platinum loading in the formulation, or the alternatively the platinum can be replaced with non-precious materials. The purpose of this work is to discover and synthesize alternative catalysts for metal-air battery applications through optimized method without addition of precious metals. Different non-precious metals are investigated as the replacement of the precious metal including transition metal alloys, transition metal or mixed metal oxides, and chalcogenides. These types of metals, alone, still exhibits unsatisfying, yet worse, kinetics in comparison to the precious metals. Nitrogen-doped carbon material is a recently well studied carbon based material that exhibits great potential towards the cathodic reaction.6 Nitrogen-doped carbon materials are found to exhibit higher catalytic activity compared to the mentioned types of metals for its improved conductivity. Benefits of the carbon based materials are in its abundance and minimal environmental footprints. However, the degradation of these materials has demonstrated loss of catalytic activity through destruction of active sites containing the transition metal centre, ultimately causing infeasible stability. To compensate for these drawbacks and other limits of the nitrogen-doped carbon based catalysts, nitrogen-doped carbon nanotubes (NCNT) are also investigated in the series of study. The first investigation focuses on a development of a simple method to thermally synthesize a non-precious metal based nitrogen-doped graphene (NG) electrocatalyst using exfoliated graphene (Ex-G) and urea with varying amounts of iron (Fe) precursor. The morphology and structural features of the synthesized electrocatalyst (Fe-NG) were characterized by SEM and TEM, revealing the existence of graphitic nanoshells that potentially contribute to the ORR activity by providing a higher degree of edge plane exposure. The surface elemental composition of the catalyst was analyzed through XPS, which showed high content of a total N species (~8 at.%) indicative of the effective N-doping, present mostly in the form of pyridinic nitrogen groups. The oxygen reduction reaction (ORR) performance of the catalyst was evaluated by rotating disk electrode voltammetry in alkaline electrolyte and in a zinc-air battery cell. Fe-NG demonstrated high onset and half-wave potentials of -0.023 V (vs. SCE) and -0.110 V (vs. SCE), respectively. This excellent ORR activity is translated into practical zinc-air battery performance capabilities approaching that of commercial platinum based catalyst. Another approach was made in the carbon materials to further improve the cost of the electrode. Popular carbon allotropes, CNT and graphene, are combined as a composite (GC) and heteroatoms, nitrogen and sulfur, are introduced in order to improve the charge distribution of the graphitic network. Dopants were doped through two step processes; nitrogen dopant was introduced into the graphitic framework followed by the sulfur dopant. The coexistence of the two heteroatoms as dopants demonstrated outstanding ORR performance to those of reported as metal free catalysts. Furthermore, effects of temperature were investigated through comparing ORR performances of the catalysts synthesized in two different temperatures (500 ??? and 900 ???) during the N-doping process (consistent temperature was used for S-doping). Through XPS analysis of the surface chemistry of catalysts produced with high temperature during the N-doping step showed absence of N-species after the subsequent S-doping process (GC-NHS). Thus, the synergetic effects of the two heteroatoms were not revealed during the half-cell testing. Meanwhile, the two heteroatoms were verified in the catalyst synthesized though using low temperature during the N-doping process followed by the S-doping step (GC-NLS). Consequently, ORR activity of the resulting material demonstrated promising onset and half-wave potentials of -0.117 V (vs. SCE) and -0.193 V (vs. SCE). In combination of these investigations, this document introduces thorough study of novel materials and their performance in its application as ORR catalyst in metal air batteries. Moreover, this report provides detailed fundamental insights of carbon allotropes, and their properties as potential elecrocatalysts and essential concepts in electrochemistry that lies behind zinc-air batteries. The outstanding performances of carbon based electrocatalyst are reviewed and used as the guides for further direction in the development of metal-air batteries as a promising sustainable energy resource in the future.

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CHEN, YU-WEI, and 陳昱維. "Applications of Magnetic Carbon Encapsulated Iron Nanoparticle for Matrix-Assisted Laser Desorption Mass Spectrometry Analysis of Polycyclic Aromatic Hydrocarbons in Air Particulate Matter." Thesis, 2019. http://ndltd.ncl.edu.tw/handle/5v87d2.

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碩士 國立暨南國際大學 應用化學系 107 Polycyclic aromatic hydrocarbons ( PAHs ) are notorious environmental pollutants generated primarily during the incomplete combustion of organic materials. Due to the relatively low volatility of PAHs, they are adsorbed on suspended particulates ( e.g. PM2.5 ) and gradually aggregate in the air. Many PAHs have toxic, mutagenic and/or carcinogenic properties. Matrix-Assisted Laser Desorption/Ionization Time of Flight Mass Spectrometry ( MALDI-TOF MS ) has the advantages of good sensitivity, high accuracy, wide detection quality, and easy analysis. It is used to quickly analyze molecular information contained in environmental or biological samples. However, organic compound-based substrates conventionally used are not suitable for analyzing low molecular weight small molecules such as polycyclic aromatic hydrocarbon molecules. In recent years, many research efforts have proposed the use of new carbon-based materials for small molecule detection such as carbon nanotubes, nanocarbon dots, colloidal graphite, graphene, etc., because these materials have good laser energy absorption characteristics. At the same time, there is almost no matrix background interference when detecting small molecular weight samples. In this work, we use a simple and rapid method by using magnetic carbon encapsulated iron nanoparticle ( Fe@C ) as both MALDI matrix and PAH adsorbents for Matrix-Assisted Laser Desorption/ Ionization Time of Flight Mass Spectrometry ( MALDI-TOF MS ) analysis of PAHs such as Benzo[a]pyrene ( BaP ), Benzo[g]perylene( BgP ), and Pyrene. The experimental results show that using Fe@C as MALDI matrix can effectively improve the intensity of PAHs and be successfully applied to detect polycyclic aromatic hydrocarbons on suspended particles. This method expands the application of Fe@C and provides a new matrix material selection for the detection of polycyclic aromatic hydrocarbons in air pollutants.

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O'Donovan-Zavada, Robert Anthony. "Hierarchical three-dimensional Fe-Ni hydroxide nanosheet arrays on carbon fiber electrodes for oxygen evolution reaction." Thesis, 2014. http://hdl.handle.net/2152/26199.

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As demands for alternative sources of energy increase over the coming decades, water electrolysis will play a larger role in meeting our needs. The oxygen evolution reaction (OER) component of water electrolysis suffers from slow kinetics. An efficient, inexpensive, alternative electrocatalyst is needed. We present here high-activity, low onset potential, stable catalyst materials for OER based on a hierarchical network architecture consisting of Fe and Ni coated on carbon fiber paper (CFP). Several compositions of Fe-Ni electrodes were grown on CFP using a hydrothermal method, which produced an interconnected nanosheet network morphology. The materials were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD). Electrochemical performance of the catalyst was examined by cyclic voltammetry (CV) and linear sweep voltammetry (LSV). The best electrodes showed favorable activity (23 mA/cm², 60 mA/mg), onset potential (1.42 V vs. RHE), and cyclability. text

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