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Silva, Francisco das Chagas Beserra da. "Estudo da mistura comercial dolomita-quartzo, dopada com Hg(I), Cd(II) e Cr(III), para adsor??o de H2S." Universidade Federal do Rio Grande do Norte, 2013. http://repositorio.ufrn.br:8080/jspui/handle/123456789/17715.
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Previous issue date: 2013-07-30The present work was to carry out a study on the adsorption of hydrogen sulfide (H2S) in arrays synthesized from a commercial clay mineral formed by a mixture of dolomite and quartz. To produce the ion exchange matrix were made using aqueous solutions of salts of cobalt II chloride hexahydrate (CoCl2.6H2O) II cadmium nitrate tetrahydrate (Cd (NO3)2.4H2O) I mercuric chloride (HgCl) nitrate and chromium III pentahydrate (Cr (NO3)3.5H2O). The arrays were subjected to hydrogen sulphide gas passage for one hour. To check the amount of gas adsorbed was used gravimetric process. The best result was in the adsorption matrix doped with cadmium and the solution retained for a longer time than the largest amount of H2S was the cobalt matrix. The matrix unmodified exhibited poor adsorption capacity. The characterization of the matrices were used XRD, XRF and IV. Mother with cadmium showed a high capacity in ion exchange, because the percentage of cadmium increased from 0% to 81.38% by replacing atoms of calcium and silicon which increased from 96.54% to 17.56% and 15, 72% to 0.32%, respectively, but also the best performance in adsorption of H2S adsorbing 11.89507 mg per gram of matrix
O presente trabalho teve como finalidade realizar um estudo sobre a capacidade de adsor??o de g?s sulf?drico(H2S) em matrizes sintetizadas a partir de um argilomineral comercial formado por uma mistura de dolomita e quartzo. Para produzir as matrizes foram feitas trocas i?nicas utilizando as solu??es aquosas dos sais: cloreto de cobalto II hexaidratado(CoCl2.6H2O), nitrato de c?dmio II tetraidratado (Cd(NO3)2.4H2O), cloreto de merc?rio I (HgCl) e nitrato de cromo III pentaidratado(Cr(NO3)3.5H2O). As matrizes foram submetidas a passagem de g?s sulf?drico durante uma hora. Para verificar a quantidade de g?s adsorvido foi utilizado o processo de gravimetria. O melhor resultado na adsor??o foi com a matriz dopada com a solu??o de c?dmio e a que reteve por mais tempo a maior quantidade de H2S, foi a matriz com cobalto. A matriz n?o modificada apresentou uma fraca capacidade de adsor??o. Na caracteriza??o das matrizes foram utilizadas an?lises de DRX, FRX e IV. A matriz com c?dmio apresentou uma alta capacidade na troca i?nica, pois a porcentagem de c?dmio passou de 0% para 81,38%, substituindo ?tomos de c?lcio e de sil?cio que passaram de 96,54% para 17,56% e de 15,72% para 0,32%, respectivamente, como tamb?m, o melhor desempenho na adsor??o, adsorvendo 11,89507mg de H2S por grama de matriz
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Vieira, Rodrigo Silveira. "Remoção e recuperação de ions Hg (II) utilizando quitosana natural e reticulada." [s.n.], 2004. http://repositorio.unicamp.br/jspui/handle/REPOSIP/267672.
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Orientador : Marisa Masumi BeppuDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica
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Resumo: A quitosana vem sendo largamente investigada para remoção e recuperação de íons metálicos a partir de efluentes industriais. Este material, obtido por desacetilação da quitina, possui em sua estrutura grupos amino e hidroxilas, bastante reativos, que o toma um polímero de grande interesse industrial. Este trabalho objetivou estudar a adsorção e dessorção de íons Hg(II) em quito sana, utilizando-se o método estático e dinâmico de adsorção. Uma etapa de reticulação com glutaraldeído ou epic1oridrina, foi proposta, visando maximizar a adsorção e ainda caracterizar quais grupos funcionais estão envolvidos na adsorção. A reação de reticulação com glutaraldeído ou epic1oridrina, toma os grupos amino ou hidroxilas indisponíveis, respectivamente, podendo-se caracterizar a influência destes grupos na etapa de adsorção. O estudo de adsorção estática foi feito utilizando-se membranas de quito sana na forma natural ou reticulada, variando-se o pH da fase fluida e a concentração dos íons de Hg(II). O estudo de dessorção foi feito utilizandose NaCl, CaCl2 e EDTA como eluente, de modo a verificar a natureza da força de adsorção. A adsorção dinâmica foi feita utilizando-se quito sana reticulada com glutaraldeído, variando-se: vazão, tamanho da coluna, concentração do soluto e tamanho da partícula do adsorvente. Observou-se que a quito sana reticulada com glutaraldeído apresentou maior capacidade de adsorção e que a adsorção foi influenciada pelo pH da solução. O estudo de dessorção mostrou que as espécies metálicas podem ser recuperadas, utilizando-se NaCl como eluente e que a força de adsorção é principalmente de natureza eletrostática. A cinética de adsorção mostrou que não houve diferença na taxa para os três tipos de quito sana, indicando um possível efeito de filme sobre a superfície do adsorvente. A capacidade de adsorção para os experimentos em coluna foi em tomo de 75% daquela avaliada sobre condições de equilíbrio (método estático) e as espécies metálicas puderam ser recuperadas utilizando-se um pequeno volume da solução eluente. O comportamento de adsorção e dessorção dos íons Hg(II) a partir de um efluente industrial foi avaliado, e observou-se o potencial deste material, mesmo a baixas concentrações dos íons metálicos
Abstract: Chitosan has been investigated for removal and recovery of heavy metals from industrial effluents. This material, obtained by deacetylation of chitin, contains amino and hydroxyl groups in its structure. These groups, sufficiently reactive, have made this polymer very interesting for many industries applications. The aim of this work was to study the adsorption and desorption of Hg(II) ions in chitosan, using the static and dynamic methods of adsorption. Crosslinking with glutaraldehyde and epichlorohydrin was proposed, aiming to maximize the recovery of metallic species and to understand the adsorption mechanism. These species were chosen in order to verify which groups participate in the adsorption. The study of static adsorption was made using raw and crosslinked membranes of chitosan, as a function of pH and concentration of Hg(II) ions. The desorption was studied using NaCI, CaCl2 and EDTA as eluent, in order to verify the kind of adsorption. The dynamic adsorption was done using glutaraldehyde-crosslinked chitosan, as a function of the particle size, concentration, size of column and flow rate. The capacity of adsorption on glutaraldehyde-crosslinked chitosan was higher than that on raw chitosan and it was found to be pH-dependent. The desorption study showed that metallic species can be easily recovered, using NaCI as eluent, and that the adsorption force is mainly of electrostatic nature. The kinetics of adsorption showed there is no difference in the rate for the three kinds of chitosan, indicating a possible film effect at the surface of adsorbent. For column experiments the adsorption capacity was around 75% of the value found on equilibrium conditions (static method) and could be recovered using a small volume of eluent solution. The behavior of adsorption and desorption of Hg(lI) ions, from an industrial effluent, was evaluated and it was observed the potential of chitosan as adsorbent, even in low concentrations of metallic species
Mestrado
Mestre em Engenharia Química
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Marshall, A. "Spectroscopy of Cr'3'+ ions in some garnet crystals." Thesis, University of Strathclyde, 1988. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382441.
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Renault, Pierre-Olivier. "Etude des défauts d'implantation dans le Hg 0,8 Cd 0,2 Te par diffusion diffuse des RX près des taches de Bragg." Poitiers, 1995. http://www.theses.fr/1995POIT2254.
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Ce travail concerne l'etude des defauts induits par des implantations d'ions al a 320 kev dans le semi-conducteur ii-vi, hg#0#,#8cd#0#,#2te. Les implantations, de 10#1#3 a 10#1#5 al/cm#2, ont ete realisees d'une part a temperature ambiante, d'autre part a la temperature de l'azote liquide. L'etude a ete menee a l'aide de la technique de diffusion diffuse des rayons x pres des taches de bragg. Les implantations realisees a temperature ambiante induisent des amas de defauts ponctuels dont le champ de deplacement a longue distance est anisotrope, comme celui des boucles de dislocation. L'analyse de la diffusion diffuse nous permet de caracteriser la nature, la taille, le type des boucles de dislocation. Apres des implantations a la temperature t90k, les observations in situ des profils des pics de bragg mettent en evidence un epaulement dans la direction 111 perpendiculaire a la surface. Cet epaulement est attribue a un volume comprime dans la direction 111. Ce volume pourrait etre associe a la presence d'une couche deformee enterree, situee a une profondeur voisine du maximum du depot d'energie nucleaire donne par la simulation trim. Un stade de recuit a ete mis en evidence autour de 150k. Apres des recuits isochrones dans le domaine de temperature 200-300k, nous analysons la repartition de la diffusion diffuse pres des taches de bragg de maniere a caracteriser precisement les boucles de dislocation induites par l'implantation
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Leigh, Nathan D. "On the velocities of ions produced at surfaces /." free to MU campus, to others for purchase, 2001. http://wwwlib.umi.com/cr/mo/fullcit?p3012996.
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Abramowitz, Peter Prep. "Forming nitrides with low-energy ions on low-K dielectrics /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
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Mello, Jesse Vincent. "Biarylpyridine fluorescent chemosensors : synthesis, structural studies, and combinatorial discovery of a Hg(II) sensor /." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2004. http://wwwlib.umi.com/cr/ucsd/fullcit?p3129954.
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Guggilla, Srinivas. "Synthesis and characterization of Perovskite-related ionic and mixed ionic-electronic conductors /." Digital version accessible at:, 1998. http://wwwlib.umi.com/cr/utexas/main.
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Daignère, Arnold. "Cristallogenèse et propriétés supraconductrices de l'oxyde (Hg,M)Ba2CuO4+delta (M=Cu,Mo,W,Cr)." Caen, 2001. http://www.theses.fr/2001CAEN2034.
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La synthèse de cristaux supraconducteurs de Hg-1201 (Tc max-97K) en utilisant différents cations stabilisateurs de la couche mercure associée ou non à des recuits post-synthèse a permis d'obtenir des taux de dopage allant du régime sous-dopé à surdopé. L'influence de ce dopage et de l'anisotropie sur les lignes d'irréversibilité (LI) et de second pic dans le plan (champ-température) a été discutée par mesures d'aimantation et de transport. Des mesures de relaxation magnétique ont été effectuées au voisinage du second pic. Cette relaxation s'est avérée être de type plastique quel que soit l'état de dopage de notre phase, et ce, que les cristaux présentent ou non le phénomène du second pic. Ce dernier n'a pu être relié à une transition de phase du réseau de vortex entre les phases de Bragg glass et de vortex glass. Un saut d'aimantation dans la partie réversible des cycles d'aimantation isothermes et isochamps a été observé, saut que nous avons associé à une fusion ou à une sublimation du réseau de vortex. Par analyse des fluctuations critiques, les composés sous-dopés présentent un comportement bidimensionnel, alors que les ajustements 2D et 3D donnent des résultats équivalents pour le composé optimisé (étude magnétique). Pour un état de dopage donné (légèrement sous-dopé), un crossover dimensionnel a été mis en évidence, 3D près de la transition supraconductrice et 2D à plus haute température (étude de transport). Ces résultats sont discutés en considérant la paraconductivité et le pseudogap.
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Shen, Jim Xiangxin. "Evaluation of metal ion complexation in a quadrupole ion trap mass spectrometer /." Digital version accessible at:, 1999. http://wwwlib.umi.com/cr/utexas/main.
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Blair, Sheryl McCutcheon. "Evaluation of metal complexation in molecular recognition using quadrupole ion trap mass spectrometry /." Digital version accessible at:, 2000. http://wwwlib.umi.com/cr/utexas/main.
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Chen, Grace Shiahuy. "An experimental and theoretical study of dinitrogen related chemistry : electronic structures of aliphatic diazonium ions, symmetrical and asymmetrical azines, and group VIA trisubstituted carbenium ions /." free to MU campus, to others for purchase, 1996. http://wwwlib.umi.com/cr/mo/fullcit?p9737904.
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Reyzer, Michelle Lee. "Evaluation of metal binding interactions in host-guest chemistry using quadrupole ion trap mass spectrometry /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004364.
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Rashatasakhon, Paitoon. "Vinyloxocarbenium ions and cyclopentenyl oxyallyl, zwitterions in 4+3 cyloadddition reactions /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3052211.
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Kelmer, Gislayne Aparecida Rodrigues. "Propostas de métodos para determinações de As, Cd, Cr(III), Cr(VI), Hg, Ni, Pb e Se em fertilizantes minerais por AAS e ICP OES." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/46/46136/tde-11042017-090632/.
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O objetivo deste trabalho foi o desenvolvimento de métodos visando às determinações de As, Cd, Cr(III), Cr(VI), Hg, Ni, Pb e Se em fertilizantes minerais por espectrometria de absorção atômica com atomização em forno de grafite (GF AAS) e espectrometria de emissão óptica com plasma indutivamente acoplado (ICP OES). Foi empregado Material de Referência Certificado de fertilizante inorgânico (SRM® 695, NIST) e amostra de candidato a Material de Referência Rastreado (MRR), mix-micro, cedida pelo LANAGRO de Goiânia. A análise da amostra MRR, obtida por fluorescência de Raios-X (XRF), mostrou a complexidade dessa matriz devido, principalmente à presença de elevados teores de Al, Si, Fe, Ti, Mn e Ca. Foram feitas otimizações do ICP OES visando condições robustas para determinações de As, Cd, Cr, Ni e Pb em soluções com nebulização direta e As, Hg e Se com nebulização combinada com geração de vapor. Foi verificado que os métodos de preparo de amostras, 3051 e 3052 recomendados pela USEPA (Agência de Proteção Ambiental dos Estados Unidos), podem ser aplicados apenas para determinação de As, Cd e Pb. Elementos fortemente ligados a matriz, como Cr e Ni, não foram quantitativamente extraídos. A digestão pelo método 3052 na presença de H3BO3 alterou o erro relativo de -36% para -15% para o Cr e a concentração de Ni também foi maior nesse caso. Para a determinação simultânea de As, Hg e Se no ICP OES por geração de vapor (VG-ICP OES), foi utilizado um procedimento de pré-redução para Se(VI), envolvendo aquecimento a 90°C das soluções em meio de HCl 6 mol L-1. A etapa adicional para redução de Se não prejudicou as determinações de As e Hg. A geração de vapor para a determinação simultânea dos elementos ocorreu com a separação gás-líquido dentro da câmara ciclônica. A extração usando banho e sonda ultrassônica, na presença de ácidos diluídos (HCl, HNO3, H3PO4), não influenciou consideravelmente as determinações de As, Cd, Cr, Ni e Pb por ICP OES e Se por GF AAS. O borbulhamento de ar atmosférico foi suficiente para uma eficiência de extração comparável aos dispositivos ultrassônicos. A utilização de pequenos volumes de ácidos concentrados mostrou ser adequada para melhorar a eficiência de extração, principalmente para o Ni. O HCl concentrado foi a condição mais adequada para a extração. Com relação à determinação de Cr(VI), foram estudadas diferentes soluções extratoras alcalinas e, além do uso do banho termostático, foi avaliada a extração utilizando ultrassom. Devido à complexidade das amostras de fertilizantes, estratégias foram adotadas para adequar o método da difenilcarbazida a essa matriz. Além da espectrofotometria de absorção molecular na região do visível, a determinação do teor de Cr(VI) nos extratos foi feita por GF AAS e as concentrações de Cr(VI) estavam abaixo do limite de detecção do método.The aim of this work was the development of methods for the determination of As, Cd, Cr(III) Cr(VI), Hg, Ni, Pb and Se in mineral fertilizers by graphite furnace atomic absorption spectrometry (GF AAS) and inductively coupled plasma optical emission spectrometry (ICP OES). It was employed a Certified Reference Material (SRM® 695 - Trace elements in multi-nutrient fertilizer) from the National Institute of Standards and Technology (NIST) and an in-lab candidate of Reference Material (MR), mix-micro sample (raw material used in formulation of mineral fertilizers to improve micronutrient content) provided by LANAGRO (Laboratório Nacional Agropecuário, Goiania, Brazil). The analysis of MR sample by X-ray fluorescence (XRF) showed the matrix complexity, mainly due to the presence of high levels of Al, Si, Fe, Ti, Mn and Ca. The ICP OES optimization was carried out aiming rubust conditions for As, Cd, Cr, Ni and Pb determination by direct nebulization solutions, and As, Hg and Se with nebulization combined with vapor generation. It was found that the methods of sample preparation, USEPA 3051 and 3052 (US Environmental Protection Agency), can be applied only for the determination of As, Cd and Pb. Elements that are strongly bound to the matrix, such as Cr and Ni were not quantitatively extracted. Digestion by method USEPA 3052 in the presence of H3BO3 alter the relative error from -36% to -15% for Cr and Ni concentration was also higher in this case. For the simultaneous determination of As, Hg and Se by ICP OES vapor generation (VG-ICP OES), a pre-reduction procedure for Se (VI) was necessary, involving heating at 90 °C of the solutions in HCl 6 mol L-1. The additional step for Se reduction did not impair Hg and As determination. The vapor generation for simultaneous elements determination with the gas-liquid separation occurring within the cyclonic spray chamber. The extraction using bath and ultrasonic probe in the presence of dilute acids (HCl, HNO3, H3PO4) did not influence considerably the determination of As, Cd, Cr, Ni and Pb by ICP OES and Se by GF AAS. Only atmospheric air bubbling was enough for an efficient extraction providing results comparable to ultrasonic devices. The use of small volumes of concentrated acids proved to be suitable for improving extraction efficiency, particularly for Ni. Concentrated HCl was the most suitable condition for extraction. For Cr(VI) determination, various solutions and alkaline extractant was studied, and the use of the thermostatic bath and ultrasound bath was evaluated. Due to the complexity of fertilizer samples, strategies were adopted to adapt diphenylcarbazide method to this matrix. Besides Cr(VI) determination in extracts by molecular absorption spectrophotometry in the visible region, it was also performed by GF AAS and Cr(VI) concentration was below limit of detection of the method.
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Shivitz, Robert William. "Techniques in laser cooling and trapping of atomic Ytterbium /." view abstract or download file of text, 2003. http://wwwlib.umi.com/cr/uoregon/fullcit?p3095274.
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Thesis (Ph. D.)--University of Oregon, 2003.Typescript. Includes vita and abstract. Includes bibliographical references (leaves 235-246). Also available for download via the World Wide Web; free to University of Oregon users.
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Furquim, Tatiana Valéria. "Estudo de métodos para determinações de As, Cd, Cr, Hg e Pb em fertilizantes minerais por MIP OES." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/46/46137/tde-31102018-145925/.
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O objetivo deste trabalho foi o desenvolvimento de métodos para determinações simultâneas de As e Hg por geração de hidreto e vapor frio e determinações simultâneas de Cd, Cr e Pb por nebulização direta da solução de digeridos dos fertilizantes minerais por espectrometria de emissão óptica com plasma induzido por micro-ondas (MIP OES). Durante o desenvolvimento dos métodos foram empregadas amostras de fertilizantes minerais de programas interlaboratoriais e também Material de Referência Certificado de fertilizante inorgânico (SRM® 695 do NIST). Foram realizadas otimizações nas condições de operação do MIP OES para se obter as melhores condições para determinações dos analitos de interesse. O método por geração química de vapor de As e Hg foi desenvolvido sem a etapa de pré-redução do arsênio, sendo possível a determinação simultânea do As e Hg. A não necessidade da etapa de pré-redução foi constatada em estudos com soluçõespadrão de 20 mg L-1 As(III), 20 mg L-1 As(V) e mistura das duas espécies nas mesmas concentrações 10 mg L-1 As(III) + 10 mg L-1 As(V), na ausência e presença de diferentes concentrações de iodeto de potássio (0 a 1% m v-1). Os resultados obtidos demonstraram que não houve influência significativa com o uso do iodeto de potássio, podendo ser eliminada a etapa de pré-redução sem comprometer os resultados. Também foram avaliadas as respostas analíticas obtidas em diferentes concentrações da solução redutora (NaBH4) para que fosse escolhida a melhor condição de formação de hidreto de arsênio e vapor de mercúrio. Os resultados mostraram que a concentração de 0,5% (m v-1) de NaBH4 em meio de 0,25% (m v-1) de NaOH foi a que apresentou melhor exatidão. Foram também avaliados os efeitos de matriz na geração química de vapor, com amostra de fertilizante mineral contendo Zn a 10% (m v-1), Cu a 5% (m v-1) e Mn a 9,8% (m v-1), e os resultados obtidos demonstraram que nas condições adotadas, os elementos presentes na amostra não causaram interferências. Com a mesma amostra de fertilizante, também foram realizados testes de efeito de matriz para aplicação do método de determinações de Cd, Cr e Pb, e para estes analitos também foram observados resultados livres de interferências significativas devido à presença de elevada concentração de outros elementos. Os métodos desenvolvidos foram validados de acordo com o Manual de Garantia da Qualidade (MAPA), apresentando boa linearidade para a faixa de trabalho empregada, apresentando r>0,99 e o gráfico de resíduos mostrou um padrão bastante aleatório, ou seja, o modelo linear fornece um ajuste decente aos dados, boa seletividade, não sofrendo interferência da matriz, boa repetibilidade e precisão intermediária, apresentando CV(%) menor que o desvio padrão relativo calculado pela equação de Horwitz e obedecendo aos testes de hipóteses (ANOVA), boa exatidão, com erros relativos entre -1 e -12%, ou seja, menor que 20%, que é o critério de aceitabilidade estabelecido. Os métodos desenvolvidos são comparáveis aos oficiaisThe objective of this work was the development of methods for simultaneous determinations of As and Hg by hydride and vapor generation and simultaneous determinations of Cd, Cr and Pb by direct nebulization of the solution in mineral fertilizers by microwave induced plasma - OES. During development mineral fertilizers samples from the interlaboratory program and also reference material of inorganic fertilizer (SRM® 695 - NIST) were used. Optimizations were made in the operation conditions of the MIP OES to obtain better conditions of the interest analytes determination. The method by chemical vapor generation was also optimized, and the arsenic pre-reduction step was taken, so that simultaneous determination of As and Hg was possible, the test evaluated the observed result in standard solutions of As(III), As(V) and a standard solution containing the two species in the same concentration, in the presence of different concentrations of potassium iodide and also in its absence. The results showed that there wasnt significant influence with the usage of potassium iodide, and the pre-reduction stage could be eliminated without impairing the results. The analytical responses obtained at different concentrations of the reducing solution (NaBH4) were also evaluated in order to obtain the best hydride and vapor formation conditions. The chosen concentration was 0.5% (m v-1) of NaBH4 in 0.25% (m v-1) NaOH. A matrix effect test with mineral fertilizer sample containing 10% Zn (m v-1), Cu at 5% (m v-1) and Mn at 9.8% (m v-1) was carried out to evaluate the effect of these elements on the reaction of chemical vapor generation, and the results showed that in the adopted conditions, the elements present in the sample didnt cause significant interferences. Matrix effect tests were also performed for the Cd, Cr and Pb determinations, and for these analytes, significant interferences werent observed due to the presence of high concentrations of Mn, Zn and Cu. The methods developed were validated according to the Manual of Quality Assurance (MAPA), presenting good linearity for the working range employed, presenting r> 0.99 and the residual plot showed a fairly random pattern, the linear model provides a decent fit to the data, good repeatability and intermediate precision, presenting lower RSD than the RSD calculated by the Horwitz equation and obeying the hypothesis tests (ANOVA), good accuracy, with relative errors between -1 and - 12%, that is, less than 20%, according to the acceptability established criterion. The methods developed are comparable to the official ones.
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Bogatko, Stuart A. "Ab initio study of the structure and dynamics of solvated highly charged metal ions." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p3336643.
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Thesis (Ph. D.)--University of California, San Diego, 2008.Title from first page of PDF file (viewed January 9, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.
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Sathiosatham, Muhunthan. "The synthesis and noncovalent electron-transfer studies of anthracene and dimethylaniline substituted nucleic acid bases and G-quartet formation in the absence of templating metal ions." Digital version:, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p9992906.
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Comet, Maxime. "Excitation du 201 Hg dans les plasmas produits par laser." Thesis, Bordeaux, 2014. http://www.theses.fr/2014BORD0458/document.
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L'utilisation des lasers de puissance permet l'étude des propriétés de la matière dans des conditions extrêmes de température et de densité. En effet, l'interaction d'un laser de puissance sur une cible créée un plasma dont la température est suffisamment grande pour atteindre des degrés d'ionisation élevés. Ces conditions peuvent permettre, via divers processus, d'exciter le noyau dans un état nucléaire et notamment dans un état isomère. Un noyau d'intérêt pour étudier ces phénomènes est le 201 Hg. Ce travail de thèse s'inscrit dans le cadre du dimensionnement d'une expérience visant la mise en évidence de l'excitation du 201 Hg dans un plasma laser.La première partie de ce manuscrit présente la détermination des taux d'excitation nucléaire dans les plasmas. Depuis une dizaine d'années les taux d'excitation sont déterminés en utilisant le modèle de l'atome moyen. Afin de valider ce modèle, un code, appelé ADAM (Au-Delà de l'Atome Moyen), a été développé afin de calculer le taux d'excitation nucléaire en DCA (Detailed Conguration Accounting). Il nous permettra d'en déduire un domaine thermodynamique en température et densité où les taux d'excitation déterminés avec le modèle de l'atome moyen sont pertinents.La deuxième partie présente le couplage des taux d'excitation nucléaire avec un code hydrodynamique afin d'en déduire, pour différentes intensités laser, le nombre de noyaux qu'il serait possible d'exciter par tir laser. Enfin, dans une dernière partie,les premières approches expérimentales qui serviront au dimensionnement d'une expérience sur une installation laser sont présentées. Ces approches sont basées sur la détection et la détermination de la quantité d'ions multichargés obtenue loin de la cible (~80 cm). Pour cela, un déviateur électrostatique a été utiliséThe use of high power lasers allows the study of the properties of matter in extremeconditions of temperature and density. Indeed, the interaction of a power laser and atarget creates a plasma in which the temperature is high enough to reach important degrees of ionization. These conditions can allow the excitation of the nucleus. Anucleus of interest to study the processes of nuclear excitation is the 201 Hg. Thiswork aims to design an experiment where the 201 Hg excitation will be observed in aplasma produced by a high power laser. The first part of this manuscript presents the calculation of the expected nuclear excitation rates in the plasma. For about ten years, nuclear excitation rates have been calculated using the average atom model. To validate this model a code named ADAM (french acronym for Beyond The Average Atom Model) was developed to calculate the nuclear excitation rates under the DCA (Detailed Configuration Accounting) hypothesis. ADAM allows us to deduce the thermo dynamical domain where the nuclear excitation rates determined with the average atom model are relevant. The second part of this manuscript presents the coupling of the excitation rate calculation with a hydrodynamic code to calculate the number of excited nuclei produced in one laser shot for different laser intensity. Finally, in the last part, first experimental approaches which will be used to design an experiment on a laser installation are presented. These approaches are based on the detection and determination of the amount of multicharged ions obtained far from the target (~80 cm). For this purpose, an electrostatic analyzer was used
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Unal, Ridvan. "Energy and charge state dependences of transfer ionization to single capture ratio for fast multiply charged ions on Helium /." Search for this dissertation online, 2001. http://wwwlib.umi.com/cr/ksu/main.
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MORTIER, MICHEL. "Luminescence des ions ni#2#+ et cr#3#+ dans balif#3, kmgf#3 et rbcaf#3." Paris 6, 1994. http://www.theses.fr/1994PA066656.
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Dans ce travail, nous presentons une etude comparee de la luminescence des ions ni#2#+ et cr#3#+ dans une perovskite classique stable (kmgf#3), une perovskite instable presentant des transitions de phase structurales (rbcaf#3) et enfin la perovskite inversee balif#3. Compte tenu de la petite taille des ions li#+, balif#3 possede la structure perovskite inversee avec l'ion monovalent li#+ au centre de l'octaedre f#6 et l'ion divalent ba#2#+ dans le site de coordinence 12. Cette situation unique dans la famille des composes amf#3 confere un interet particulier a l'etude des ions de transitions dans balif#3. Du fait de sa structure inversee, le champ cristallin au centre de l'octaedre est de 10% plus fort que dans une perovskite classique de meme parametre de maille. Les sites des ions luminescents sont identifies par r. P. E. ; une estimation de la covalence est egalement proposee. Les parametres spectroscopiques usuels sont evalues d'apres les donnees d'emission et d'excitation. Les effets de la transition de phase quadratique orthorhombique sont mis en evidence sur les spectres optiques de rbcaf#3:ni#2#+. Le couplage electron-phonon est etudie a travers la reconstruction des bandes d'emission vibroniques prenant en compte la densite d'etats de phonons de la matrice dans un modele de pryce. La linearite du couplage electron-phonon est verifiee dans ces composes. Les premiers travaux concernant une application potentielle comme laser infrarouge a temperature ambiante de balif#3:ni#2#+ sont egalement presentes. L'influence de la concentration sur la duree de vie est mesuree ainsi que la section efficace laser
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Tichy, Robin Sarah. "Mechanisms and stability of oxide-ion transport in homogenous and heterogeneous ceramic membranes /." Full text (PDF) from UMI/Dissertation Abstracts International, 2001. http://wwwlib.umi.com/cr/utexas/fullcit?p3008457.
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Jemmali, Fadil. "Contribution à l'étude de l'oxydation des spinelles ferreux finement divisés : cas des magnétites mixtes substituées par des ions divalents Zn**(2+), Co**(2+), des ions trivalents Al**(3+), Cr**(3+), des ions tétravalents Ti**(4+)." Dijon, 1985. http://www.theses.fr/1985DIJOS061.
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Travaux effectués en vue d'étudier la réactivité en présence d'oxygène des composés du titre. Plusieurs techniques ont été employées : par thermogravimétrie et conductivité électrique, on a montré dans les magnétites substituées par Cr ou Al, une différence de réactivité de Fe**(2+) suivant qu'ils sont en site octaédrique ou tétraédrique; la cinétique d'oxydation en microbalance et en conductivité a permis de préciser le mécanisme de l'oxydation Fe**(2+) -> Fe**(3+). Dans les systèmes entre Fe::(3)O::(4) et ZnFe::(2)O::(4), CoFe::(2)O::(4), FeAl::(2)O::(4), FeCr::(2)O::(4) et Fe::(2)TiO::(4) et dans le système FeCr::(2)O::(4)-FeAl::(2)O::(4); la spectrométrie IR a permis d'étudier les phases lacunaires susceptibles de donner un ordre de lacunes et de cations sur les sites octaédriques; enfin la diffraction RX, la spectrométrie IR et la conductivité électrique ont permis d'examiner la stabilité thermique de ces phases
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Ostrander, Chad Michael. "Development and evaluation of the central trapping electrode trapped-ion cell for Fourier transform mass spectrometry /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004351.
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Goolsby, Brian James. "Techniques for improved mass spectrometric analysis of biologically relevant molecules produced by MALDI and ESI in the quadrupole ion trap /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004273.
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Halitim, Foudil. "Etude des propriétés mécaniques et analyses physicochimiques de l'alumine polycristalline implantée par différents ions métalliques (Ti,Cr,Ni)." Lyon, INSA, 1994. http://www.theses.fr/1994ISAL0005.
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L'implantation ionique est l'une des techniques les plus récentes de traitement de surface utilisées pour améliorer les propriétés mécaniques de matériaux céramiques. L'étude que nous avons effectuée sur l'implantation ionique du titane, chrome et du nickel dans l'alumine polycristalline a été entreprise suivant deux objectifs principaux. Premièrement, l'étude des propriétés mécaniques telles que la dureté et la ténacité faite par la méthode d'indentation Vickers, montre l'évolution de ces propriétés en fonction des différents paramètres utilisés ( dose, température des recuits ). Deuxièmement une étude physico-chimique utilisant la microscopie électronique à balayage, pour les observations directes en surface des composés chimiques formés, et les rayons X rasants permettant leur identification et enfin la spectrométrie de masse des ions secondaires qui permet de montrer les profils des éléments implantés et leur évolution. L'ensemble de ces analyses permet d'expliquer les variations des paramètres mécaniques étudiésIon implantation is among the most recent technics for surface treatment used to improve mechanical properties of ceramics materials. The study of ion implantation in polycristalline alumina with titanium, chromium and nickel, has been undertaken for two principal objectives : The first one, the study of the mechanical properties such as the hardness and the toughness by Vickers indentation method, show the improve of these properties in relation with the different parameters used ( fluence, temperature of heat treatment ). The second one, a physico-chemical study of the treated surface using SEM and XRD techniques to explain the evolution of the mechanical properties of ion implanted surface and correlate them with the hardness and toughness parameters obtained from Vickers indentation of the sample
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Wycoff, Donald E. "Catalysis of interfacial transfer of photo-generated electrons : a study of four molybdenum-sulfur complex ions mediating electron transfer across a colloidal semiconductor-liquid interface /." free to MU campus, to others for purchase, 2004. http://wwwlib.umi.com/cr/mo/fullcit?p3164554.
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Gaul, Erhard Werner. "Fully ionized helium waveguides for laser wakefield acceleration /." Full text (PDF) from UMI/Dissertation Abstracts International, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p3004269.
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Vosnidou, Nancy Carol Hoffman. "Computational analysis of cadherins : sequence analysis of dimerization properties and quantum caculations of calcium coordination characteristics /." free to MU campus, to others for purchase, 2002. http://wwwlib.umi.com/cr/mo/fullcit?p3060154.
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Nashiem, Rodney Emil. "The photochemistry and photophysics of cis- and trans-[Cr(cyclam)(NCS)¦2]§+ ions in aqueous and nonaqueous solvents." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0019/NQ37900.pdf.
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Arkin, C. Richard. "Theoretical treatment of ion motion in an open trapped-ion cell for use in Fourier transform ion cyclotron resonance mass spectrometry." Digital version:, 2000. http://wwwlib.umi.com/cr/utexas/fullcit?p9992745.
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Cai, Laizhong. "Evidence for molecular activated recombination of He single ions from particle balance measurements in helium and hydrogen mixture plasmas in PISCES A." Diss., Connect to a 24 p. preview or request complete full text in PDF format. Access restricted to UC campuses, 2008. http://wwwlib.umi.com/cr/ucsd/fullcit?p3320080.
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Thesis (Ph. D.)--University of California, San Diego, 2008.Title from first page of PDF file (viewed September 11, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 138-143).
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Onaga, Helena. "Metodos de pre-concentração para determinação simultanea de Cr, Mn, Fe, Co, Ni, Cu, Zn, Hg e Pb por fluorescencia de raios-X." [s.n.], 1996. http://repositorio.unicamp.br/jspui/handle/REPOSIP/248799.
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Orientador: Maria Izabel Maretti Silveira BuenoDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Quimica
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Oudich, Fayssal. "Contribution à l’étude thermodynamique du système Pb-Bi-(Hg)-Fe-(Al,Cr)-O : étude des systèmes Bi2O3–PbO–Al2O3 et Bi2O3–PbO–Fe2O3." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0273/document.
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Le présent travail de recherche s’inscrit dans un projet global, dont le but est de comprendre et résoudre un problème de corrosion d’un acier dit T91 par un mélange métallique liquide de plomb et bismuth. Il présente un intérêt pour la communauté nucléaire qui envisage de développer une nouvelle génération de réacteurs dits ADS. Ce travail est une contribution à l’étude thermodynamique d’un système plus complexe composé de plusieurs éléments : Al, Bi, Pb, Fe, Cr et l’oxygène. Plus précisément, il a été focalisé sur les systèmes à base de mélanges d’oxydes Bi2O3 + PbO + Al2O3 et Bi2O3 + PbO + Fe2O3. Un travail expérimental a été accompli, au cours duquel ces mélanges à différentes proportions ont été recuits à une température supérieure à 600 °C pendant plusieurs jours, suivi de l’analyse des échantillons par des techniques de pointe. Il a permis de découvrir les différents produits formés dans les différentes conditions de température, de compositions et atmosphères. Les résultats ont permis de faire aussi une modélisation à l’aide d’un outil informatique. Tout cela aide à mieux comprendre et anticiper la formation des produits de corrosion de l’acier par le mélange métallique liquideThis research work takes part in a global project whose aim is to understand and solve a corrosion problem of a steel called T91 caused by a liquid mixture of lead-bismuth. It presents a great interest for the nuclear community who aims to develop a new generation of reactors called ADS. This study is a contribution to the thermodynamic study of a complex system involving several elements such as Al, Bi, Pb, Fe, Cr and oxygen. More precisely, it was focused on mixtures of the following oxides Bi2O3 + PbO + Al2O3 and Bi2O3 + PbO + Fe2O3. A long experimental work had been accomplished, in which mixtures of different proportions of these oxides were prepared and heated above 600 °C for several days, followed by samples analyses by use of accurate and advanced techniques. It allowed discovering the different products formed within the different experimental conditions. The results have been modeled using a computer tool. All this allowed a better understanding and anticipating the corrosion products formation of the T91 steel by the metallic liquid
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Meis, Constantin. "Etude de l'effet Doppler du 2e ordre sur la transition hyperfine microonde à 40.5 GHz du niveau fondamental ²S¹/ des ions¹⁹⁹ Hg⁺ piégés dans une trappe radiofréquence." Grenoble 2 : ANRT, 1988. http://catalogue.bnf.fr/ark:/12148/cb37616605d.
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Tchebotareva, Anna. "Propriétés optiques et structurales des nanocristaux de InAs fabriqués dans le substrat de Si(100) par implantation séquentielle des ions As+ et In+." [Montréal] : Université de Montréal, 2002. http://wwwlib.umi.com/cr/umontreal/fullcit?pNQ82763.
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Thèse (Ph. D.)--Université de Montréal, 2003."NQ-82763." "Thèse présentée à la faculté des études supérieures en vue de l'obtention du grade de philosophiae doctor (Ph. D.) en physique." Version électronique également disponible sur Internet.
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Meis, Constantin. "Étude de l'effet doppler du 2e ordre sur la transition hyperfine micro-onde à 40,5 Ghz du niveau fondamental ²S½ des ions ¹⁹⁹ Hg⁺ piégés dans une trappe radiofréquence." Paris 11, 1988. http://www.theses.fr/1988PA112313.
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On a étudié les propriétés énergétiques des ions ¹⁹⁹Hg⁺ piégés dans une trappe radiofréquence cylindrique afin d'évoluer le décalage dû à l'effet Doppler du second ordre sur la raie de résonance à 40,5 Ghz de la transition hyperfine du niveau fondamental ²s ₁/₂. Cette étude, théorique et expérimentale, a été menée pour améliorer la précision de l'étalon de fréquence atomique à ion mercure 199. On a voulu, par ailleurs, donner un caractère général aux résultats déduits afin qu'ils puissent être applicables à n'importe quel type d'ions possédant une structure hyperfine, confiné dans une trappe radiofréquence quadrupolaire ou cylindrique. On a créé pour cela un formalisme analytique mettant en jeu des paramètres physiques pouvant être mesurés expérimentalement afin d'évaluer l'énergie cinétique moyenne des ions confinés, ce qui permet de connaitre l’effet Doppler du second ordre proportionnel à cette quantité. L'énergie cinétique moyenne calculée tient compte aussi bien de la contribution du macro-mouvement lent, qu'on a supposé thermalisé, que de celle du micromouvement rapide dû au champ de confinement. On a considéré un modèle thermalisé de la distribution des charges à l’intérieur d'un pseudo potentiel de confinement, tout en tenant compte du potentiel d'interaction électrique entre les tons piégés (charge d'espace). Ce formalisme permet, en outre, d'estimer la densité centrale du nuage ionique formé, ainsi que le potentiel de la charge d'espace. Les résultats ont été comparés à des calculs numériques de simulation, pour différentes conditions de confinement, montrant un très bon accord. Une étude numérique a permis d'étudier les propriétés de confinement du pseudo potentiel créé à l'intérieur d'une trappe radiofréquence cylindrique, afin d'adapter ce formalisme à nos conditions expérimentales. On a démontré que le potentiel efficace de cette trappe est très différent de celui d'une trappe hyperboloïde (quadrupolaire) radiofréquence. Les conditions de sphéricité et d'harmonicité du pseudo potentiel ont été définies, ainsi que la valeur de la fréquence théorique séculaire résultante. On a aussi déduit que des densités plus élevées (environ 25 %) peuvent être atteintes dans une trappe cylindrique pour les mêmes tensions de confinement. Le modèle a été appliqué à différentes conditions expérimentales en mesurant, à chaque fois, les paramètres physiques intervenant dans le formalisme, qui sont le nombre d'ions total et la fréquence du macro mouvement séculaire déplacée par la charge d'espace. On en a déduit que la température d'un nuage de 2 millions d’ions ¹⁹⁹Hg⁺, piégés dans un pseudo potentiel de fréquence séculaire théorique 40 khz, est typiquement de 3300 ± 100 K dans un vide résiduel de 10 ⁻⁸ Torr. Le déplacement du â l'effet Doppler du second ordre dans ce cas est : Δ f ÷ f = -(5,44 ± 0,16) 10⁻¹² En utilisant l'hélium comme gaz tampon, on a étudié le refroidissement collisionnel de ce nuage d'ions dans les mêmes conditions de confinement. La plus basse température mesurée est de 700 K pour une pression d'hélium de 3. 10 ⁻⁵ Torr. Le déplacement dû à l'effet Doppler du second ordre est, dans ce cas: Δ f ÷ f = - (1. 76 ± 0. 11 à 10⁻¹²). Finalement, on a mis en évidence la faible distorsion du pseudo potentiel due aux asymétries de la trappe cylindrique. Les irrégularités sont partiellement compensées par la forme particulière du potentiel efficaceWe have studied the energy properties of 199Hg⁺ stored in an R. F. Cylindrical trap in order to evaluate the 2nd order Doppler effect on the resonance line at 40. 5 Ghz of the hyperfine transition of the fundamental level ²s ₁/₂. The purpose of this study, both experimental and theoretical, is to improve the precision of 199 mercury ions atomic frequency standard. Besides, we wanted to give a general caracter to the issued results so as they could be applied to all kinds of tons, with an hyperfine structure, stored in an R. F. Trap, quadrupole or cylindrical. We have established an analytical formalism, using physical parameters that can be measured experimentally, in order to estimate the mean kinetic energy of the stored ions, the 2nd order Doppler effect being directly proportional to this quantity. The mean kinetic energy calculated by this way takes into account the contribution of slow macromotion, supposed thermalized and that of rapid micromotion due to the confining field. We have assumed a thermalized charge density distribution in a confining pseudo potential taking also into account space charge affects. The above formalism also permits to evaluate the ion cloud central density as well as space charge potential. The results have been compared to those of numerical simulation methods for differents trapping conditions showing a very good agreement. We have then carried out a numerical study of the confinement properties of an R. F. Cylindritcal trop pseudo potential so as to adjust this formalism to our experimental conditions. We have thus demonstrated that the effective potentiel of such a trap is quite different to that of a quadrupole one. We have also defined the condition of an approximate sphericity and harmonicity of the pseudo potential as well as the value of the corresponding theoretical secular frequency. We have deduced that higher density (about 25 %) can be achieved in an R. F. Cylindrical trap than in a quadrupolar one for the same trapping parameters. The model has been applied to different experimental conditions measuring each time the necessary physical parameters which are the total ion number and the macromotion secular frequency shifted by space charge. We have concluded that the temperature of an ion cloud of 2. 10⁶ 199Hg+ ions trapped in a spherical pseudo potential of 40 khz is 3300 ± 100 k in a residual vacuum of 10⁻⁸ Torr. The 2nd order Doppler effect shift in this case is : Δ f ÷ f = -(5,44 ± 0,16) 10⁻¹². We have also studied the collisional cooling of an ion cloud for the same trapping conditions using helium buffer gas. At helium pressure of 3. 10⁻⁵ Torr we have measured a lower temperature of 700 ± 60 K. The corresponding 2nd order Doppler shift is: Δ f ÷ f = - (1. 76 ± 0. 11 à 10⁻¹²). Finally, we have put in evidence the weak distortion of the pseudo potential well of an R. F. Cylindrical trap due to the irregularities
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Brunold, Thomas C. "Synthesis, optical spectroscopy and laser potential of crystals doped with tetrahedrally oxo coordinated "d"[hoch]1 ions (V[hoch4 plus], Cr[hoch 5plus] and Mn[hoch6 plus] and "d"[hoch2] ions (Cr[hoch4 plus], Mn[hoch5 plus]. Fe[hoch 6 plus] and Ru[hoch6 plus) /." Bern : [s.n.], 1996. http://www.ub.unibe.ch/content/bibliotheken_sammlungen/sondersammlungen/dissen_bestellformular/index_ger.html.
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Kuksenko, Viacheslav. "Etude expérimentale d'alliages modèles Fe-Cr irradiés." Phd thesis, Université de Rouen, 2011. http://tel.archives-ouvertes.fr/tel-00664570.
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Afin d'améliorer la compréhension de l'évolution microstructurale des alliages Fe-Cr irradiés, alliages modèles des aciers ferrito-martensitiques (F-M) à haut Cr candidats comme matériaux de structure des réacteurs de génération IV, l'évolution de la microstructure a été étudiée à l'échelle nanométrique en fonction de la teneur en Cr et de la température d'irradiation. Deux séries d'expériences ont été réalisées: ● Des alliages modèles Fe-5%Cr, Fe-9%Cr et Fe-12%Cr irradiés aux neutrons à 300°C (température minimale de service pour les aciers F-M) jusqu'à 0.6dpa ont été analysés par sonde atomique 3D (3DAP). Ces analyses ont montré que les impuretés sont également impliquées dans l'évolution microstructurale de ces alliages sous irradiation. Deux familles indépendantes de clusters ont été observées : des clusters de NiSiPCr observés dans tous les alliages et des clusters riches en Cr correspondant à la phase α ' mais observés uniquement dans les alliages sursaturés en Cr (Fe-9%Cr et Fe-12%Cr). Ce travail a montré que l'apparition des clusters de NiSiPCr est induite par l'irradiation alors que celle des clusters riches en Cr est issue d'un processus accéléré par l'irradiation. Des enrichissements en Si, P et Cr ont été observés sur les lignes de dislocations ainsi que dans des joints de grain de faible et forte désorientation dans tous les alliages. ● Des alliages Fe-9%Cr et Fe-12%Cr ont été irradiés aux ions Fe + de 150 keV à 500°C (température maximale de service pour les aciers F-M). Des expériences de MET in situ entreprises jusqu'à une dose de 1.5 dpa, ont montré que le dommage apparaissait sous la forme de boucles de dislocations distribuées de façon homogène dans les grains. Dans les deux alliages modèles les boucles sont principalement du type <100>. L'analyse par 3DAP des mêmes alliages irradiés dans les mêmes conditions mais sous forme de pointes ne révèle aucune redistribution des espèces chimiques après irradiation.
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Khaoulani, Sohayb. "Traitement d'eaux usées par adsorption sur des polymères de cyclodextrine et développement de capteurs chimiques à base de membranes de verres de chalcogénures destinées à la détection des ions Hg²⁺." Thesis, Littoral, 2015. http://www.theses.fr/2015DUNK0386/document.
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L'objectif de ce travail a consisté à identifier des polluants émergents dans des eaux usées issues de stations d'épuration ainsi que dans le milieu naturel et à proposer une méthode de remédiation et un suivi de ces polluants. Dans un premier temps, nous avons identifié les polluants organiques contenus dans les échantillons d'eaux usées et issues du milieu naturel par chromatographie en phase liquide ou gazeuse couplée à une spectrométrie de masse, chromatographie en phase gazeuse par espace de tête statique et par spectrométrie par torche à plasma couplée à une spectrométrie de masse. Différents polluants ont été trouvés tels que les phtalates, des substances médicamenteuses, le cholestérol et des éléments de traces métalliques. Dans le but de piéger ces polluants, différents polymères de cyclodextrine (CD) solubles et insolubles dans l'eau ont été synthétisés et leurs capacités d'adsorption ont été évaluées. Après adsorption sur les polymères de CD, nous avons observé une diminution de la teneur en carbone organique total (COT) de l'effluent. Ces polymères se sont révélés être des adsorbants efficaces. Dans un second temps, des verres du système pseudo-ternaire Agl-HgS-As₂S₃ ont été synthétisés en ajoutant le composé le composé Agl dans le système pseudo-binaire HgS-As₂S₃. Ces verres de chalcogénures sont des membranes ionosélectives permettant de détecter les ions Hg²⁺ dans les effluents. Tout d'abord, nous avons défini le domaine vitreux des verres à l'aide de la diffraction des rayons X, ensuite les propriétés macroscopiques des verres ont été déterminées. Ainsi, les propriétés de transport ont été étudiées à l'aide de la spectroscopie d'impédance complexe montrant que l'ajout d'Agl dans le verre pseudo-binaire HgS-As₂S₃ provoque une augmentation de la conductivité ionique. Afin de comprendre ce phénomène, diverses études structurales ont été déployées par spectroscopie Raman, diffraction de neutrons et de rayon X haute énergie. Ces techniques ont montré que l'évolution de la conductivité ionique est dépendante de la structure du verre qui forme des chemins préférentiels de conduction. Enfin, différents capteurs avec différentes compositions sont testés afin de définir la sensibilité, la limite de détection et les coefficients de sélectivité en présence d'ions interférentsThe aim of this work was to identify the emerging pollutants in the effluents of wastewater treatment plants as well as in the natural environment, and to propose a method of remediation and monitoring of these pollutants. In the first part of the thesis, we have identified the organic pollutants contained in the wastewater samples using (i) gas and/or liquid chromatography coupled with a mass spectrometry, (ii) static-headspace gas chromatography, and (iii) inductively coupled plasma atomic emission spectroscopy. Different pollutants were found such as phthalates, drugs, cholesterol, and heavy metal traces. In order to trap these pollutants, various water soluble/insoluble cyclodextrin β-CD polymers have been synthesized and their adsorption capacities were evaluated. After the analysis of the effluent samples, we observed a decrease of the Total Organic Carbon (TOC). This decrease was attributed to the adsorption of pollutant by CD polymers which have proven to be effective adsorbents. The second part of the thesis included two main sub-parts : (i) a synthesis and characterization part and (ii) an application part. In the first sub-part, chalcogenide glasses in the pseudo-ternary Agl-HgS-As₂S₃ system have been synthesized by adding silver iodide "Agl" to the quasi-binary HgS-As₂S₃ system. The vitreous domain and the macroscopic properties of glass samples were determined. Electrical conductivity of glasses was studied using both the complex impedance spectroscopy and resistivity measurements ; it was found that adding Agl to the quasi-binary HgS-As₂S₃ alloy causes an increase in the ionic conductivity. Structural studies, using various techniques as Raman spectroscopy, neutron scattering and high-energy X-ray diffraction, have been performed in order to decipher the relation between both structural and transport properties in these glasses. In the second sub-part, the obtained glasses in the ternary system were used as membranes in chemical sensors dedicated to mercury detection in aqueous solution. As a result, various sensors with different compositions were tested to determine their corresponding sensitivity, detection limit and selectivity coefficients in the presence of interfering ions
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Zambetta, Paula Munhoz Antunes. "Espécies químicas inorgânicas (Al, As, Cd, Cr, Cu, Fe, Hg, Mn, Ni, Pb e Sn) no sedimento e nos sólidos em suspensão do rio Corumbataí, SP." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/91/91131/tde-11122006-142152/.
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Os teores totais e trocáveis de alumínio, arsênio, cádmio, cobre, ferro, manganês, mercúrio, níquel, chumbo e estrôncio, foram determinados em amostras de sedimento do rio Corumbataí. As leituras para quantificação dos elementos foram feitas por espectrometria de emissão atômica com plasma acoplado indutivamente (ICP-AES), análise por ativação neutrônica (AAN) e espectrometria de fluorescência atômica (AFS). As amostras para determinação dos teores totais de metais, quantificados por ICP-AES e AFS foram digeridas em bombas de Teflon em meio de água régia. Para quantificação de metais trocáveis utilizou-se extração a frio com HCl 1,0 M. O As foi quantificado por AFS através de geração de hidretos. Para comparação de resultados, Fe, Cr e As foram também analisados por AAN, método em que a amostra foi irradiada com fluxo de nêutrons térmicos de 1012n cm-2 s-1 e a determinação do elemento feita em espectrômetro de raios gama por meio das radiações emitidas pelos radionuclídeos formados. As amostras de sedimento foram coletadas em sete pontos ao longo do Rio Corumbataí, em março, agosto e novembro de 2004 e fevereiro de 2005. Coletas de águas superficiais para a determinação de variáveis físicas, químicas e biológicas, as quais compõem o Índice de Qualidade de Água (IQA), preconizado pela CETESB, foram realizadas concomitantemente. No período de cheia, ou seja, novembro de 2004 e fevereiro de 2005 foram obtidas amostras de sólidos em suspensão, que passaram pelos mesmos procedimentos descritos para sedimento. As amostras foram caracterizadas quanto à granulometria e conteúdo de C e N, evidenciando os baixos níveis de carbono nas partículas e a classificação arenosa dos sedimentos, cuja granulometria mostrou-se relevante na dinâmica dos metais no ecossistema aquático. Não houveram indícios de que o sedimento do rio estivesse contaminado por elementos metálicos. As partículas finas (<63 µm) dos sólidos em suspensão, com maiores teores de carbono, foram responsáveis pelo transporte desses elementos até o rio Piracicaba. A qualidade da água, medida através do IQA, foi considerada Boa, à exceção dos pontos de coleta 6 e 7 que sofrem maior impacto devido ao despejo de efluentes do município de Rio Claro e do bairro Santa Teresinha, e foram classificados com qualidade Aceitável em três épocas de coleta.Total and exchangeable levels of aluminum, arsenic, cadmium, cupper, iron, manganese, mercury, nickel, plumb and strontium, were determined in sediment samples from Corumbataí river. The measurements for the elements quantification were made by atomic emission spectrometry with inductively coupled plasma (ICP-AES), neutron activation analyses (NAA) and atomic fluorescence spectrometry (AFS). The samples for total metals load determination, quantified by ICP-AES and AFS were extracted in Teflon bombs with aqua regia. Cold extraction with HCl 1,0 M was used for the quantification of exchangeable metals. As were quantified by AFS through hydride generation technique. For results comparison, Fe, Cr and As were also analyzed by NAA, method that the sample was irradiated with 1012n cm-2 s-1 thermal neutrons flux and the element determination is made by gamma ray spectrometry through the radionucleotideos radiation emission. The sediment samples were collected in seven sites in the Corumbataí River, in March, August and November 2004 and February 2005. Superficial water sampling for the determination of physics, chemical and biological variables which set up the Water Quality Index IQA, commended by CETESB, were made concomitantly. In the rainy period, corresponded to November 2004 and February 2005, were collected suspended solids that went through the same procedures described for sediment. The sample were grain size, C and N percentage characterized becoming evident the low levels of carbon and the sediment classification as sandy, in which the grain size show up relevant in the metals dynamics in that aquatic environment. There were no indications of metallic elements contamination in the Corumbataí River. The suspended matter clay particles (<63 µm), with higher carbon levels in which are adsorbed greater quantities of metals are responsible for these elements transport for the Piracicaba river. The water quality, measured through IQA is Good, exception made to the 6 and 7 sites that received greater impact due to the effluents discharge from counties of Rio Claro, Santa Gertrudes and the district of Santa Teresinha, and were classified as Acceptable in three sampling times.
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Stenger, Jean-François. "Étude par résonance paramagnétique électronique des ions fe#3#+, cr#3#+ et des défauts dans les cristaux de ktiopo#4 et isotypes." Nancy 1, 1992. http://www.theses.fr/1992NAN10373.
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Le travail présenté dans ce mémoire porte sur l'étude des défauts ponctuels dans les cristaux de la famille (k,rb)tiopo#4 doués de propriétés optiques non linéaires. Ces dernières sont attribuées au niveau des groupements titanyls. Toute substitution du titane par un autre élément est un facteur potentiel d'altération de la propriété de doublage de fréquence. L'étude a été faite par résonance paramagnétique électronique (RPE) sur deux monocristaux dont l'un est dopé au fer. Quatre centres fe#3#+ sont observés pour lesquels tous les paramètres de l'hamiltonien de spin sont déterminés. Les cristaux appartiennent au groupe pna2#1. Les sites titane sont en position générale. La localisation des centres a été faite en comparant les pseudosymetries des constantes du quatrième ordre de structure fine avec telles du quatrième ordre du champ cristallin des deux octaèdres (tio#6). Chaque type d'octaèdre peut être occupé par deux types de centres paramagnétiques fe#3#+ associés à des mécanismes de compensation de charge différente. L'absence d'une forte déviation axiale par rapport à une symétrie cubique montre que la compensation de charge n'est pas à courte distance. Par ailleurs deux centres cr#3#+ sont observés. L'analyse sur poudre de la solution solide (k,rb)tiopo#4 met en évidence l'influence des ions alcalins sur le champ cristallin agissant sur fe#3#+, en particulier l'effet d'ordre désordre k/rb. L'irradiation provoque la création de centres ti#3#+ présentant en RPE une structure superhyperfine due au couplage du spin électronique de ti#3#+ avec les spins nucléaires de deux phosphores et d'un potassium
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RANDRIANOHAVY, JEAN VICTOR. "Etude de transitions de phase structurales du compose kgaf#4 dope avec des ions cr#3#+ et fe#3#+ par resonance paramagnetique electronique." Le Mans, 1991. http://www.theses.fr/1991LEMA1010.
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Les cristaux dopes avec des ions cr#3#+ et fe#3#+ sont synthetises suivant une methode de flux en bain de chlorure et se presentent sous forme de fines plaquettes normales a l'axe (001). Le groupe d'espace pnma de kgaf#4 a basse temperature est determine par la diffraction des rayons x. L'etude structurale de la phase haute temperature n'est pas actuellement realisee, mais le groupe d'espace amma est choisi en s'appuyant sur les donnees relatives a un compose isotype a temperature ambiante: kfef#4. Dans ce travail, nous avons analyse a temperature ambiante les spectres rpe et determine les principaux parametres de l'hamiltonien de spin des ions cr#3#+ et fe#3#+. L'application du principe de superposition de newman aux parametres b#2#m ne donne globalement des resultats satisfaisants que si les deux conditions suivantes sont prises en compte: 1) les contributions des liaisons axiales et des liaisons equatoriales sont considerees separement; 2) les valeurs angulaires #i et #i deduites de l'etude radiocristallographique sont legerement modifiees. Les etudes effectuees sur kgaf#4 a haute temperature par resonance paramagnetique electronique et par spectroscopie raman permettent de montrer un phenomene transitionnel tres complexe et qu'il existe en realite deux transitions de phase structurales separees par une phase intermediaire dont nous sommes incapables de preciser actuellement la nature
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Bamba, Gaoussou. "Influence du silicium sur l'oxydation thermique des aciers inoxydables ferritiques Fe-Cr sous oxygène ou dans la vapeur d'eau." Grenoble INPG, 2006. http://www.theses.fr/2006INPG0035.
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Pour assurer leur protection à long terme contre la corrosion sèche à haute température sous atmosphère oxydante, les aciers inoxydables doivent établir une couche d'oxyde de chrome dense, continue, et adhérente dont la croissance doit être relativement lente. L'addition du silicium dans l'acier permet d'améliorer la résistance à l'oxydation grâce à l'établissement d'une couche de silice localisée à l'interface entre le métal et l'oxyde. Nous avons confirmé cet effet bénéfique en suivant les cinétiques d'oxydation d'alliages Fe-15Cr, Fe-15Cr-0,5Si et Fe-15Cr-ISi en atmosphère d'oxygène ou de vapeur d'eau. La caractérisation de la silice a été réalisée par microscopie électronique à transmission. Ce travail a permis également d'indiquer les mécanismes de croissance de l'oxyde dans les deux atmosphères oxydantes O2 et H2O. Pour la première fois, une série d'expériences d'oxydation alternée 18O2/1 O2 et H218O/ H216O suivies d'une détermination du sens de croissance par SIMS à montrer clairement les différences de mécanisme d'oxydation, cationique sous O2 et anionique sous H2O. L'utilisation de la Microscopie Photoélectrochimie (Mpec) a permis de discriminer à une échelle très fine les nodules d'oxydes générés par « oxydation catastrophique» à différents stades d'avancement. La détermination de l'énergie d'adhérence des couches de chromine Cr2O3 sur leurs substrats métalliques par traction sous MEB a montré l'effet bénéfique de H20 lié au transpon anionique. Au contraire, le silicium détériore notablement l'adhérence des couchesTo improve their corrosion resistance at high temperatures under oxidising atmospheres, stainless steels must establish a dense oxide film which must be continuous, uniform and adherent to the substrate. Lt is also known that relatively small additions of silicon have a beneficial effect on oxidation resistance due to the formation of a layer of silica adjacent to the metal. This film can act as a diffùsion barrier inhibiting outward cationic transport. This effect was confirnled by kinetics measurement during oxidation of Fe-15Cr, Fe-15Cr-0,5Si, Fe-15Cr-1 Si alloys in oxygen or water vapour. Silica was detected by TEM analysis. By means of oxygen labelling in two stage oxidations, H216O followed by H218O, the growth direction within the oxide scale was determined with secondary ion mass spectrometry (SIMS). Simitar experiments were made in oxygen with the isotopes 18O2 /16O2. An increased metal transport was observed when the samples were oxidised in O2 while in H2O the transport was essentially anionic. The use of photoelectrochemical microscropy analysis permitted us to discriminate the formation of nodular oxides at differents stages of their evolution and understand the breakaway phenomenon. The adhesion energies of chromia scales were dctermined by in situ tensile test. The beneficial effect of H2O was confirmed, due to anionic transport. On the contrary, silicon strongly decreased scale adhesion energies
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Andrade, Mauricio Gomes de [UNESP]. "Elementos-traço As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se e Zn em latossolos e plantas de milho após treze aplicações anuais de lodo de esgoto." Universidade Estadual Paulista (UNESP), 2011. http://hdl.handle.net/11449/100841.
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andrade_mg_dr_jabo.pdf: 575183 bytes, checksum: c078d7148dcec00acf084e11bfb365c2 (MD5)O uso do lodo de esgoto (LE) com finalidade agronômica e/ou condicionador é uma das alternativas ambientalmente e economicamente atraente, quando comparadas a outros destinos (incineração, aterro sanitário, etc.). As substâncias inorgânicas potencialmente tóxicas contidas no LE são uma das maiores preocupações ao meio ambiente e à cadeia trófica. O objetivo deste trabalho foi avaliar os teores e o efeito cumulativo dos elementos As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se e Zn, em dois latossolos vermelhos (um eutroférrico – LVef, e um distrófico – LVd) e plantas de milho (Zea mays L.) cultivadas nos mesmos após a aplicação de LE por treze anos ininterruptos. Em condições de campo e delineamento experimental de blocos ao acaso, cada solo recebeu quatro tratamentos (0; 5; 10 e 20 t de LE ha1) com cinco repetições. Amostras dos insumos agrícolas aplicados na cultura do milho, LE, solos, materiais vegetais e materiais de referência certificados foram digeridas em forno de micro-ondas (método 3051A), e os analitos foram quantificados por ICP-OES. Após 13 aplicações anuais sucessivas de LE no LVef e LVd, os maiores teores dos ETs foram encontrados no LVef e ainda não atingiram o valor de investigação (VI) agrícola (mais restritivo) da resolução 420 do CONAMA. Persistindo a atual taxa de aplicação de LE e teores médios de ET incorporados aos solos, é de se esperar que o Ba, Cd, Cr, Cu, Ni e Zn serão os primeiros elementos a atingir o VI no LVef. Para o LVd, o primeiro elemento a atingir o VI é o Cr somente. Os teores de ET encontrados nos insumos agrícolas não devem causar impacto ambiental imediato. Os ETs não proporcionaram fitotoxidade ou contaminação nas partes aéreas, folhas para diagnose e grãos das plantas de milho
The use of sewage sludge (SS) as agronomic and/or soil conditioner purposes presents a correct environmental and economically attractive alternative when compared to other disposal methods as incineration and landfills. The potentially toxic inorganic substances contained in SS is a major concern for the environment and food chain. This work aimed evaluate the content and the cumulative effect of the Trace Elements (TE) As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se, and Zn in two different soils: an Eutroferric Clayed Red Latosol (Typic Eutrorthox – “E”) and a Dystrophic Red Latosol (Typic Haplorthox – “H”) and with maize plants (Zea mays L.) growth after fertilize the soil with SS for thirteen years continuously. Under field conditions and under a randomized blocks experimental design each soil received four treatments (0, 5, 10, and 20 t of SS ha-1) with five replications. Fertilizers, SS, soils, vegetal materials, and the reference material were digested in microwave oven (method 3051A) and the analytes were quantified by ICP-OES. After thirteen years fertilizing the soil with SS in the soils “E” and “H”, the higher amounts were found in the “E” and these amounts did not reach the agricultural investigation value (more restrictive) yet. Persisting the actual fertilization rate of SS and an average amount of TE incorporated in the soil, Ba, Cd, Cr, Cu, Ni, and Zn will be probably the firsts elements to reach the agricultural investigation value in the “E”. To “H”, the first element to reach this value will be probably Cr. The TE found in the fertilizers should not cause immediate environmental impact. The TE did not provide neither phytotoxicity nor contamination in the maize aerial part, diagnose leaf, and grains
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Barbosa, Patricia de Souza Medeiros. "Desenvolvimento de métodos analíticos para determinação de As, Cd, Cr, Hg e Pb em embalagens celulósicas para alimentos por espectrometria de absorção atômica e amostragem direta de sólidos." Universidade de São Paulo, 2009. http://www.teses.usp.br/teses/disponiveis/46/46133/tde-05102009-103704/.
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No presente trabalho foram desenvolvidos métodos analíticos para a determinação de As, Cd, Cr, Hg e Pb em embalagens celulósicas para alimentos por espectrometria de absorção atômica com atomização em forno de grafite e amostragem direta de sólidos (SS-GF AAS). Para a determinação direta de Hg, a solução de KMnO4 e a mistura oxidante (HNO3 + H2SO4) com a plataforma e parede interna do tubo modificadas com Pd apresentaram os melhores resultados. A mistura oxidante promoveu o pré-tratamento térmico in situ do papel, reduzindo o sinal de fundo. Foi investigada a viabilidade de empregar papéis de filtro, impregnados com concentrações conhecidas dos analitos e moídos por moagem criogênica, como padrões sólidos para calibração do equipamento. Os padrões sólidos produzidos apresentaram boa homogeneidade para As, Cd, Hg e Pb, adequada para microanálises e submicroanálises. Não foi desenvolvido método para determinação direta de Cr devido à contaminação durante a etapa de moagem. Foram construídas curvas analíticas de calibração utilizando-se massas crescentes de um único padrão sólido e massas similares dos padrões contendo diferentes concentrações dos analitos. As curvas obtidas foram concordantes em termos de coeficientes angulares, com razões de aproximadamente 1, indicando que ambos procedimentos de calibração podem ser empregados para SS-GF AAS. Materiais de referência certificados de matriz vegetal foram analisados para avaliar a exatidão dos métodos propostos empregando-se as curvas obtidas. Os resultados para As, Cd e Pb apresentaram boa exatidão e precisão. Os limites de detecção encontrados para a análise direta de sólidos foram: 0,36 µg g-1 para As, 4,0 ng g-1 para Cd, 0,46 µg g-1 para Hg e 0,036 µg g-1 para Pb. O emprego dos métodos desenvolvidos na determinação direta de As, Cd, Hg e Pb em amostras de embalagens celulósicas para alimentos indicou que estes podem ser utilizados no controle de qualidade dessas embalagens, apresentando boa sensibilidade, precisão e exatidão. As concentrações de Cd e Pb nas embalagens analisadas variaram, respectivamente, de 0,015 a 0,099 µg g-1 e de 0,05 a 6,70 µg g-1. As concentrações de As e Hg nas embalagens ficaram abaixo dos limites de detecção. Foi possível a determinação de Cr nos digeridos de pedaços das embalagens, obtendo-se concentrações de 1,8 a 4,1 µg g-1.In the present work analytical methods for determination of As, Cd, Cr, Hg and Pb in paper and board food packaging materials by solid sampling graphite furnace atomic absorption spectrometry (SS-GF AAS) were developed. For direct determination of Hg, the best results were achieved using KMnO4 solution and an oxidant mixture (HNO3 + H2SO4) in combination with the graphite platform and inner wall of graphite tube modified with palladium as permanent modifier. The oxidant mixture allowed the \"in situ\" thermal pretreatment, reducing the background signals. The feasibility of using cryogenic ground spiked filter papers with different concentrations of the analyte as synthetic calibrating standards was investigated. The calibrating standards showed good homogeneity for As, Cd, Hg and Pb being suitable for both microanalysis and submicroanalysis. The method for the direct determination of Cr was not developed due to the contamination during the grinding step. The analytical calibration curves were made by increasing masses of one calibrating standard and similar masses of the calibrating standards containing different concentrations of the analyte. The ratio between slopes of analytical curves were approximately 1 for As, Cd, Hg e Pb, indicating the adequacy of using both calibrating procedures for SS-GF AAS. Vegetable certified reference materials were analyzed to evaluate the accuracy of the proposed methods. The results for As, Cd e Pb presented good accuracy and precision. The detection limits for the solid sample analysis were: 0,36 µg g-1 for As, 4,0 ng g-1 for Cd, 0,46 µg g-1 for Hg and 0,036 µg g-1 for Pb. The direct determination of As, Cd, Hg and Pb in paper and board food packaging material samples were successfully done indicating that the developed methods can be employed in the quality control of these samples with good sensibility, precision and accuracy. The concentration of Cd and Pb in analyzed packaging materials ranged from 0,015 to 0,099 µg g-1 and from 0,05 to 6,70 µg g-1, respectively. The concentration of As and Hg in packaging materials were below to the detection limits. It was possible the determination of Cr in solution after pieces of packaging materials digestion. The concentrations of Cr ranged from 1,8 to 4,1 µg g-1.
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Andrade, Mauricio Gomes de. "Elementos-traço As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se e Zn em latossolos e plantas de milho após treze aplicações anuais de lodo de esgoto /." Jaboticabal : [s.n.], 2011. http://hdl.handle.net/11449/100841.
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Orientador: Wanderley José de MeloBanca: Ademir Sérgio Ferreira de Araújo
Banca: Beatriz Monte Serrat
Banca: Marcos Omir Marques
Banca: Otávio Antônio de Camargo
Resumo: O uso do lodo de esgoto (LE) com finalidade agronômica e/ou condicionador é uma das alternativas ambientalmente e economicamente atraente, quando comparadas a outros destinos (incineração, aterro sanitário, etc.). As substâncias inorgânicas potencialmente tóxicas contidas no LE são uma das maiores preocupações ao meio ambiente e à cadeia trófica. O objetivo deste trabalho foi avaliar os teores e o efeito cumulativo dos elementos As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se e Zn, em dois latossolos vermelhos (um eutroférrico - LVef, e um distrófico - LVd) e plantas de milho (Zea mays L.) cultivadas nos mesmos após a aplicação de LE por treze anos ininterruptos. Em condições de campo e delineamento experimental de blocos ao acaso, cada solo recebeu quatro tratamentos (0; 5; 10 e 20 t de LE ha1) com cinco repetições. Amostras dos insumos agrícolas aplicados na cultura do milho, LE, solos, materiais vegetais e materiais de referência certificados foram digeridas em forno de micro-ondas (método 3051A), e os analitos foram quantificados por ICP-OES. Após 13 aplicações anuais sucessivas de LE no LVef e LVd, os maiores teores dos ETs foram encontrados no LVef e ainda não atingiram o valor de investigação (VI) agrícola (mais restritivo) da resolução 420 do CONAMA. Persistindo a atual taxa de aplicação de LE e teores médios de ET incorporados aos solos, é de se esperar que o Ba, Cd, Cr, Cu, Ni e Zn serão os primeiros elementos a atingir o VI no LVef. Para o LVd, o primeiro elemento a atingir o VI é o Cr somente. Os teores de ET encontrados nos insumos agrícolas não devem causar impacto ambiental imediato. Os ETs não proporcionaram fitotoxidade ou contaminação nas partes aéreas, folhas para diagnose e grãos das plantas de milho
Abstract: The use of sewage sludge (SS) as agronomic and/or soil conditioner purposes presents a correct environmental and economically attractive alternative when compared to other disposal methods as incineration and landfills. The potentially toxic inorganic substances contained in SS is a major concern for the environment and food chain. This work aimed evaluate the content and the cumulative effect of the Trace Elements (TE) As, Ba, Cd, Cr, Cu, Hg, Mo, Ni, Pb, Se, and Zn in two different soils: an Eutroferric Clayed Red Latosol (Typic Eutrorthox - "E") and a Dystrophic Red Latosol (Typic Haplorthox - "H") and with maize plants (Zea mays L.) growth after fertilize the soil with SS for thirteen years continuously. Under field conditions and under a randomized blocks experimental design each soil received four treatments (0, 5, 10, and 20 t of SS ha-1) with five replications. Fertilizers, SS, soils, vegetal materials, and the reference material were digested in microwave oven (method 3051A) and the analytes were quantified by ICP-OES. After thirteen years fertilizing the soil with SS in the soils "E" and "H", the higher amounts were found in the "E" and these amounts did not reach the agricultural investigation value (more restrictive) yet. Persisting the actual fertilization rate of SS and an average amount of TE incorporated in the soil, Ba, Cd, Cr, Cu, Ni, and Zn will be probably the firsts elements to reach the agricultural investigation value in the "E". To "H", the first element to reach this value will be probably Cr. The TE found in the fertilizers should not cause immediate environmental impact. The TE did not provide neither phytotoxicity nor contamination in the maize aerial part, diagnose leaf, and grains
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Caballero, Segura Bárbara, and Díaz Carlos E. Barrera. "Estudio de la Calidad Analítica en las determinaciones de Cr, Fe, Mn, Zn, Pb y Hg a través de técnicas analíticas nucleares y convencionales en Musgos de la ZMVT." Tesis de Licenciatura, Medicina-Quimica, 2013. http://ri.uaemex.mx/handle/20.500.11799/13912.
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Jousseaume, Cécile. "Li2MSiO4 : Cr (M = Mg, Zn) : localisation du chrome dans la structure, caractérisation de ses états d'oxydation et propriétés optiques." Paris 6, 2002. http://www.theses.fr/2002PA066194.
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