Made available in DSpace on 2014-06-11T19:35:06Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-09-16Bitstream added on 2014-06-13T20:45:58Z : No. of bitstreams: 1 zocolo_gj_dr_araiq.pdf: 4563540 bytes, checksum: bdaeef284bfff8ba5474160810c775a9 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Esta tese apresenta o desenvolvimento e a validação de um procedimento analítico, que permite a quantificação simultânea de sete fitoestrógenos (alteradores endócrinos - AEs) em água de rio e água sub-superficial em uma área rural com grande produção de soja. Os compostos selecionados para este estudo foram (genistina - GENIS, daidzina - DAID, equol - EQ, daidzeína - DAI, a genisteína - GEN, formononetina - FOR e biochanina - A - BIO). Este método consiste na préconcentração de amostras de água (1 L) em cartuchos Strata X de 200 mg, seguido por análise de todos as AEs por cromatografia líquida de alta eficiência com detecção por ultra - violeta (CLAE-UV). Do ponto de vista analítico, estabeleceu-se um método simples e de confiabilidade conhecida (exatidão, precisão, seletividade e robustez) para análise de sete fitoestrógenos de soja em água de rio e subsuperficial. Os limites de detecção e quantificação do método validado foram de 3,5 ng L-1 e 10 ng L-1 respectivamente para todas as moléculas estudadas e em ambas as matrizes. O método foi aplicado a amostras de água da região de Dourados (MS). Foram coletadas 92 amostras de água de rio e 16 de água subsuperficial, em quatro campanhas de amostragem ao longo de 1 ano. GENIS e DAID não foram detectadas em nenhuma das amostras. GEN e FOR foram os fitoestrógenos mais detectados, estando presentes em 50 e 34% das amostras, respectivamente. As concentrações individuais de fitoestrógenos situaram-se entre 12 e 1957 ng L-1, sendo que as maiores concentrações foram obtidas para o EQ e GEN para amostras coletadas em meses chuvosos na região de estudo. Amostras de água do rio Dourados e de água sub-superficial foram testadas para o efeito de alteração endócrina com o ensaio de levedura recombinante (RYA). O ponto de coleta de água sub-superficial (afloramento do lençol freático) apresentou... / This thesis presents the development and validation of an analytical procedure that allows the simultaneous measurement of seven phytoestrogens (endocrine disrupters - EDs) in river water and water sub-surface in a rural area with large soybean production. The compounds selected for this study were (genistin - GENIS, daidzin - DAID, equol - EQ, daidzein - DAI, genistein - GEN, formononetin - FOR and biochanin - A - BIO). This method consists of preconcentration of water samples (1 L) on Strata X cartridges of 200 mg, followed by analysis of all EDs by high performance liquid chromatography with detection by ultra - violet (HPLC-UV). From the analytical point of view, it was established a simple and known for reliability (accuracy, precision, selectivity and robustness) for consideration of seven phytoestrogens in soy and river water sub-surface. The limits of detection and quantification of the validated method were 3.5 ng L-1 and 10 ng L-1 respectively for all the molecules studied on both matrices. The method was applied to water samples from the region of Dourados (MS). We collected 92 samples of river water and 16 sub-surface water in four sampling campaigns over 1 year. GENIS and DAID were not detected in any sample. The phytoestrogens FOR and GEN were detected in most cases, present in 50 and 34% of samples respectively. Individual concentrations of phytoestrogens were between 12 and 1957 ng L-1, and the highest concentrations were obtained EQ and GEN for samples collected in the rainy months in the study area. Samples of river water Dourados and sub-surface water were tested for the presence of endocrine changes with recombinant yeast assay (RYA). The point of collecting subsurface water (groundwater upwelling) showed high estrogenicity values of 0.35 and 0.50 ng L-1 equivalent of estradiol in the months of April and August 2009 respectively. Chemometric methods of analysis... (Complete abstract click electronic access below)

Orientador: Denise Bevilaqua / Coorientador: Luiz Henrique Ferreira / Banca: Dulcimeire Aparecida Volante Zanon / Banca: Salete Linhares Queiroz / Banca: Márlon Herbert Flora Barbosa Soares / Banca: Maria José Pereira Monteiro de Almeida / Resumo: Que a leitura é essencial em qualquer setor da sociedade, isso é inconteste, mas quais mecanismos regulam esse processo e como professores e pesquisadores podem (ou devem) agir para suplantar problemas associados a essa competência? Qual o papel do leitor durante a leitura e quais procedimentos o tornam mais proficiente? Quais são as contribuições das pesquisas em educação em ciências para questões atinentes à leitura? Quais estratégias de leitura contribuem para a formação de um leitor crítico e de qual forma? Foi essencialmente o anseio de debater tais questionamentos que moveu a presente pesquisa, dividida basicamente em quatro etapas de investigação. A primeira delas consistiu de um levantamento acerca da produção científica relacionada à leitura nos periódicos brasileiros de educação em ciências. Esse levantamento revelou um crescimento das pesquisas nos últimos anos, assim como o uso de estratégias de leitura utilizadas variadas, envolvendo diferentes e criativas propostas de produção de textos conjuntamente à leitura. No entanto, aspectos cognitivos e metacognitivos da leitura não são explorados, o que poderia atuar positivamente para a melhoria do processo. As outras três etapas do trabalho consistiram no planejamento, execução e avaliação de unidades de leitura. Tais unidades de leitura são compostas basicamente por três passos: i) a produção inicial e individual de sentidos; ii) a socialização desses sentidos em grupo; e iii) a transformação dos sentidos a partir da escrita de um novo texto. Na primeira dessas unidades de leitura, é apresentada uma atividade que buscou o desenvolvimento de aspectos relacionados ao funcionamento da ciência, sobretudo a importância dos modelos. Após a leitura do texto, realizada individualmente e em silêncio, foi conduzida uma atividade... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: That reading is essential in modern society is undeniable, but it is not clear which mechanisms adjust this process and how teachers and researches can (or should) proceed to supplant problems associated with this competence. What is the role of readers during the reading process and what procedures make them more proficient? Which reading strategies can help developing the critical reading and how do they work? From these questions, the aim of this study is contribute to this discussion. The present research was divided into four parts. The first of them is the study of papers concerning reading in science education published in brazilian journals of this field. This study revealed an improvement of research related to reading in Brazil in the last years, as well as different and creative proposes that involved writing together with reading. However, cognitive and metacognitive aspects were not explored, which could help to improve this process. The other three parts consisted on the organization, execution and evaluation of reading units. These reading units involve three steps: i) an initial sense production; ii) the socialization of these senses in group; and iii) the transformation of these ideas through writing of a new text. As the first reading unit a classroom activity developed with medium level students from a pre-vestibular course in Araraquara-SP is examined. The aim of this activity was to develop aspects concerned to science function, mainly about the models‟ role in science. After reading, conducted individually and in silence, writing activities were developed. Among others, these activities demanded the formulation of questions, commentaries and question answer pairs about the text. In the second proposal conducted in classroom, a reading activity developed with 17 chemistry students from Federal University of Rondonia... (Complete abstract click electronic access below) / Doutor

This study utilizes steady state fluorescence measurements, flash-induced P680+ absorption transients, and DCIP reduction kinetics to study the inhibitory effects of linolenic acid (LA) upon Photosystem II (PSII) in whole spinach chloroplasts and insideout wheat thylakoids. It confirms the presence within PSII of LA-induced inhibition of energy trapping and/or primary charge separation (i.e., primary inhibition), in addition to donor side inhibition. The latter is diminished in the presence of 1,5-Diphenylcarbohydrazide (DPC) and probably takes place at the oxygen evolving complex. Primary inhibition, which is more controversial, probably occurs between Ph and QA, with a likely contribution at the level of PSII energy trapping. In addition, the ability of Mg2+ to delay a drop in steady state fluorescence intensity normally associated with thylakoid exposure to LA is explained by the ability of this cation to confer resistance to LA-induced destacking of thylakoid membranes. Steady state fluorescence results in the presence of DCMU, dithionite and LA also support the presence of an additional acceptor between Ph and QA. This acceptor, designated here as "R." is proposed not to be a sequential member of the transport chain, but may be accessible to it via QA when the chain blocked, such as with DCMU.R- is proposed to exert a coulombic effect upon Ph, thereby affecting the degree of primary charge recombination. It may be related to one of the several acceptors already proposed by others and the need for more study is stressed in order to confirm or refute its existence.

Pollution poses serious threats to both the environmental and the organisms that depend on their environment for survival. Due to the toxicity of most contaminants, there is a dire need for remediation of polluted sites. Remediation studies were conducted on two high priority pollutants: 2,4,6-trinitrotoluene (TNT) and crude oil. TNT was the most common explosive used in the 20th century. Continuous contamination has resulted in an urgent need for remediation. Fenton reagent provides an advanced oxidation process that is capable of remediating recalcitrant explosives, such as TNT. One drawback of Fenton chemistry is that the reaction requires acidic pH to prevent precipitation of iron. Our studies have investigated Fenton degradation of TNT at near neutral pH with several modifiers present: β-cyclodextrin, carboxymethyl-β-cyclodextrin, alcohols, and polyethylene glycol (PEG, MW 200, 400, or 600 g/mol). Fenton degradation was also carried out on other nitroaromatics to better understand the reaction mechanism with PEG 400. Further mechanistic studies investigated the production of nitrate and ammonium with and without PEG 400. The Deepwater Horizon oil spill devastated the Gulf of Mexico and the surrounding wetlands. There are several mechanisms for degradation of oil released into aquatic environments. Bioremediation is one of the most important remediation methods; however degradation becomes stagnant in low nutrient waters. Furthermore, larger molecular weight alkanes and polycyclic aromatic hydrocarbons (PAHs) are not readily available for biodegradation. Transformation of these molecules often requires initial photodegradation. We have investigated the photochemical transformation of oil films with and without photocatalysts present. To better understand the photochemical transformations that occur to the Deepwater Horizon oil, we have conducted additional studies with dispersants present.

Sulfonyl fluoride systems and their derivatives, RS02F, where R represents hydrocarbon/fluorocarbon moieties continue to be of considerable interest. The incorporation of the sulfonyl fluoride group (S02F) into molecular systems can lead to compounds that are useful as ion-exchange resins, surface active agents, fuel cell electrolytes, and strong sulfonic acids/salts. Interest in preparing SF5 containing sulfonyl fluorides led to the synthesis of the ᵝ-sultone, SF5CHCF20S02, and its rearranged product. Hydrolysis of the sultone gave SF5CH2S02F which led to the sulfonic acid and salt, SF5CH2S03H•H20 and (SF5CH2S03)2Ca. Esters of the sultone were prepared by reaction of the sultone with fluorinated alcohols in the presence of NaF to give SF5CH(S02F)C(O)OR where R = CH2CF3 and CH(CF3)2. Polymeric SF5/S02F containing esters were prepared by reaction of allyl esters, RCX(S02F)C(O)OCH2CH=CH2, in ultraviolet light where R = CF3 or SF5 and X= H or F. Fluorinated silver carboxylate salts have been useful in preparing fluoroesters from alkyl iodides. Therefore, a new silver salt, FS02CF2C(0)0Ag was prepared and characterized; its reaction with (CH3)3SiI, HOCH2CH2I and alkyl bromides and iodides are reported. In addition, new SF5 containing fluoropolymers were synthesized via reaction of fluorinated olefins with SF5Br. Reactions of SF5 containing olefins with CF30Cl, C1F and Cl2 provide reagents that may be of potential use as precursors to sulfonyl fluoride containing systems. All new compounds were characterized by their respective infrared, nmr and mass spectra.

Nitrogenase consists of two metalloproteins, the MoFe protein and the Fe protein. The MoFe protein is an α2β2 heterotetramer and the Fe protein is an α2 homodimer. The catalytic cycle of nitrogenase involves binding of the Fe protein to each αβ catalytic half of the MoFe protein, electron transfer followed by ATP hydrolysis, Pi release and eventually dissociation of the two proteins. This cycle has to be repeated eight consecutive times to reduce one molecule of N2. The two catalytic halves of the MoFe protein had been considered to be independent of each other. The research presented here showed that there is negative cooperativity associated between the two catalytic halves of the MoFe protein. The results suggested that only one half of the MoFe protein is operative during the first turnover of the enzyme. In order to understand the substrate reduction mechanism of nitrogenase, the study focused on two important enzymes of the biogeochemical nitrogen cycle: nitrite (NO2 -) and nitrate (NO3 -). Two intermediates of NO2 - reduction were trapped by a remodeled nitrogenase (α-70Ala/α-195Gln MoFe protein) and characterized by advanced spectroscopic studies. These intermediates were found to be identical to the intermediates trapped during reduction of diazene (N2H2) and hydrazine (N2H4). The pathway for reduction NO2 - to ammonia (NH3) was also proposed. NO3 - was established as a new substrate of nitrogenase. The advanced spectroscopic studies confirmed that the same two intermediates were trapped by the remodeled nitrogenase. Kinetic studies showed that two competing pathways lead to NO3 - reduction by nitrogenase, a primary 2 e- reduction pathway to form nitrite and a secondary 8 e- reduction pathway to form NH3. The pathways for reduction of NO3 - to NO2 - and NH3 were proposed.

<p>In the next few years the pollutants loading at the Slottshagen wastewater treatment plant in Norrköping is going to increase due to the reason that one of the waste water treatment plant in the district will be shut down.A survey of how these different pollutants are divided in the treatment process is therefore necessary for mapping out both the loading and treatment efficiency.This can be achieved by studying mass balances.Mass balances were carried out for the water treatment process for the mechanical/chemical,biological and the chemical stage.The mass balance studies show that the treatment efficiency was very good. However in order for the mass balances to be quite consistent and to ensure complete coverage of results and conclusions i.e. more reliable results, sludge samples should be collected and taken at different times per day and the influent rate should be investigated.In this work mass balance has been set up in order to illustrate and identify the factors that should be considered and taken care of for further estimation using mass balances in the future. Furthermore this survey results in a calculating model for the mass balances at thisplant.This calculating model is used as a tool to facilitate future calculations for mass balances for the water treatment process at Slottshagens wastewater treatment plant.Moreover it provides a basis for carrying out further estimation of the treatment process in the near future.In this project the importance of some operating parameters was also taken in consideration.This calculating model can be modified so that calculations of such operating parameters i.e. sludge loading and sludge age can be easily performed.Such information can be used further to evaluate different operation alternative in order to ensure an optimal use of the treatment process with in the plant.</p> / The model developed by this work is found in the attachment below.

In the next few years the pollutants loading at the Slottshagen wastewater treatment plant in Norrköping is going to increase due to the reason that one of the waste water treatment plant in the district will be shut down.A survey of how these different pollutants are divided in the treatment process is therefore necessary for mapping out both the loading and treatment efficiency.This can be achieved by studying mass balances.Mass balances were carried out for the water treatment process for the mechanical/chemical,biological and the chemical stage.The mass balance studies show that the treatment efficiency was very good. However in order for the mass balances to be quite consistent and to ensure complete coverage of results and conclusions i.e. more reliable results, sludge samples should be collected and taken at different times per day and the influent rate should be investigated.In this work mass balance has been set up in order to illustrate and identify the factors that should be considered and taken care of for further estimation using mass balances in the future. Furthermore this survey results in a calculating model for the mass balances at thisplant.This calculating model is used as a tool to facilitate future calculations for mass balances for the water treatment process at Slottshagens wastewater treatment plant.Moreover it provides a basis for carrying out further estimation of the treatment process in the near future.In this project the importance of some operating parameters was also taken in consideration.This calculating model can be modified so that calculations of such operating parameters i.e. sludge loading and sludge age can be easily performed.Such information can be used further to evaluate different operation alternative in order to ensure an optimal use of the treatment process with in the plant. / The model developed by this work is found in the attachment below.

Thesis (Ph. D.)--University of Missouri-Columbia, 1999. / Typescript. Vita. Includes bibliographical references (leaves 92-107). Also available on the Internet.

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