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Measuring the Radiative Lifetimes of the Vibrational Levels in the 6 sSg State of Sodium Dimers Using Time-Resolved SpectroscopySaaranen, Michael W. 03 May 2019 (has links)
No description available.
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Estudo dos principais fatores que influenciam na solubiliza??o dos hpas em ?guasSilva, Patr?cia Maria Freire da 23 February 2010 (has links)
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Previous issue date: 2010-02-23 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Polycyclic aromatic hydrocarbons (PAHs) constitute a family of compounds characterized by having two or more condensed aromatic rings and for being a class of substances that are widely distributed in the environment as a complex mixture, being very persistent in the environment due to its low solubility in water. The application of chemometric methods to analytical chemistry has provided excellent results in studying the solubility of PAHs in aqueous media in order to understand the mechanisms involved in environmental contamination. The method consists in analyzing the solubilization of PAHs from diesel oil in water varying parameters such as stirring time, volume of oil added and pH, using a full factorial design of two levels and three factors. PAHs were extracted with n-hexane and analyzed by fluorescence spectroscopy because they have molecular characteristics fluorescent due to the large number of condensed rings and links, and gas chromatography coupled to a mass spectrometer (GC-MS). The results of fluorescence analysis showed that only the stirring time and pH influenced the solubility of PAHs in diesel fuel. How is a non-selective technique for the study of fluorescence was performed on form and semi-quantitative. And for the chromatographic analysis the results showed that the solubility of the different PAHs is influenced differently so that you can classify them into groups by the results of the effects / Os hidrocarbonetos polic?clicos arom?ticos (HPAs) constituem uma fam?lia de compostos caracterizada por possu?rem dois ou mais an?is arom?ticos condensados e por ser uma classe de subst?ncias que est?o amplamente distribu?das no ambiente como uma mistura complexa, sendo bastante persistentes no ambiente devido a sua baixa solubilidade em ?gua. A aplica??o de m?todos quimiom?tricos ? qu?mica anal?tica vem proporcionando excelentes resultados no estudo da solubilidade de HPAs em meio aquoso, no sentido de entender os mecanismos envolvidos na contamina??o do ambiente. O m?todo consiste na an?lise da solubiliza??o dos HPAs de ?leo diesel em ?gua variando par?metros como tempo de agita??o, volume de ?leo adicionado e pH, atrav?s de um planejamento fatorial completo de dois n?veis e tr?s fatores. Os HPAs foram extra?dos com n-hexano e analisados atrav?s da espectroscopia de fluoresc?ncia molecular por possu?rem caracter?sticas fluorescentes devido ao grande n?mero de an?is condensados e liga??es conjugadas e cromatografia gasosa acoplada a um espectr?metro de massa (CG-EM). Os resultados da an?lise por fluoresc?ncia mostraram que, apenas o tempo de agita??o e o pH influenciaram no processo de solubiliza??o dos HPAs presentes no ?leo diesel. Como ? uma t?cnica n?o seletiva o estudo por fluoresc?ncia foi realizado de forma relativa e semi-quantitativa. E para a an?lise cromatogr?fica os resultados mostraram que a solubilidade dos diferentes HPAs ? influenciada de forma diferenciada de modo que ? poss?vel classific?-los em grupos atrav?s dos resultados dos efeitos
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Élaboration de nouveaux fluoroionophores et de supports chélatants en vue de l'amélioration de la caractérisation du fer dans les particules atmosphériques / Elaboration of new fluoroionophores and chelating supports in order to ameliorate the characterization of iron in atmospheric particlesDanjou, Pierre-Édouard 26 November 2012 (has links)
L'objet de ce travail est de fournir de nouveaux outils moléculaires pour la caractérisation physico-chimique des particules atmosphériques afin d'établir des liens entre leurs propriétés et leur toxicité pulmonaire. Nous nous sommes plus particulièrement intéressés à la détection, la quantification et le traçage du fer, élément majeur dans les particules industrielles du bassin dunkerquois. Pour ce faire, nous avons mis au point dans un premier temps, la synthèse rapide de nouvelles sondes fluorescentes par micro-ondes et ultrasons. L'étude des propriétés spectroscopiesde ces nouvelles sondes a été menée et a permis de mettre en avant un composé sélectif des ions ferriques en solution aqueuse non temponnée en présence d'autres ions métalliques. Dans un second temps, nous avons réalisé des supports solides contenant des entités chélatantes supramoléculaires ou bio-inspirées afin de séparer les traces de fer ferrique de matrices aqueuses complexes. / The aim of this work is to provide new molecular tools for the physico-chemical characterization of atmospheric particles in order to establish a link between their properties and their pulmonary toxicity. We particularly investigate the detection and quantification of iron, a major element in industrial particle of Dunkirk city, France. So, in a first hand, we have developed the efficient synthesis of new fluorescents chemosensors by ultrasounds and microwave irradiation. Then the study of these compounds was undertaken and has revealed a highly selective sensor of ferric iron in non-buffered aqueous solution in presence of other metallic cation. In the other hand, we have synthesized new solid supports which beard supramolecular chelatant or bio-inspired entities in order to separate iron traces from complex aqueous matrix.
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Aplica??o da parafina e do ?leo de linha?a como hidrofobizantes da vermiculita, para remo??o de derivados de ?leo diesel resentes em ?gua produzida sint?ticaSantos, Aline da Silva 29 October 2010 (has links)
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Previous issue date: 2010-10-29 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Produced water has lately aroused interest due to their high degree of salinity,
suspended oil particles, chemicals added in various manufacturing processes, heavy
metals and radioactivity sometimes. Along with oil and due to its high volume
production, water production is one of the pollutants of most concern in the process
of oil extraction. PAHs due to their ubiquity and their characteristics carcinogenic or
mutagenic and teratogenic even have attracted the attention of every scientific
society. Formed from the incomplete combustion of organic matter may be natural or
anthropogenic. Some materials have been researched with the goal of cleaning up
environmental matrices that may be contaminated by hydrocarbons. Among these
materials researched various clays have been employed, of which highlights the
vermiculite. The family of phyllosilicates, vermiculite for its potential and its high
hydrophobic surface area has been a tool widely used in the decontamination of
water in processes of oil spills. However, when it loses its capacity expanded
hydrophobic having the necessity of using a hidrofobizante to make it organophilic.
Among the numerous hidrofobizantes researched and used the linseed oil was the
pioneer. In this study sought to evaluate the capacity of removal of PAHs using the
vermiculite hydrofobized with linseed oil and wax also, for it was made use of the 24
full factorial design as the main tool for the experiments. We also evaluated the clay
grain size (-20 +48 and -48 +80 #), the percentage of hidrofobizante applied (5 and
10%) and salinity of the water produced synthesized in our laboratory (35,000 and
55,000 ppm). The molecular fluorescence spectroscopy due to its sensitivity and
speed was used to verify the adsorption capacity of clay, as well as gas
chromatography served as an auxiliary technique to identify and quantify the PAHs in
solution. In order to characterize the vermiculite was made use of X-ray fluorescence
and X-ray diffraction. The infrared and thermogravimetry were essential to note
hydrophobization and the amount of coating of clay. According to the fluorescence
analysis showed that the test 12 was the best result in about 98% adsorption of
fluorescent compounds, however the high salinity, the smallest particle size, the
highest percentage of hidrofobizante and the use of linseed oil showed greater
efficiency in the removal capacity of these hydrocarbons, in accordance with the
trend followed by the analysis of the major factors of the factorial design. To verify the
adsorption capacity of clay using a fixed volume of water produced synthetically,
used as the test base 12, at their respective levels and factors. Thus, it was observed
that after adding about 1 ? liters of water solution produced synthetically, about 300
times its volume in mass, the vermiculite was able to adsorb 80% of fluorescent
species present in solution / A ?gua produzida vem ultimamente despertando interesse devido ao seu
elevado grau de salinidade, part?culas de ?leo em suspens?o, produtos qu?micos
adicionados nos diversos processos de produ??o, metais pesados e algumas vezes
radioatividade. Juntamente com o petr?leo e devido ao seu elevado volume de
produ??o, a ?gua de produ??o ? um dos poluentes que mais preocupam no
processo de extra??o do ?leo. Os HPAs devido a sua ubiq?idade e suas
caracter?sticas carcinog?nicas/mutag?nicas e at? mesmo teratog?nicas v?m
chamando a aten??o de toda sociedade cient?fica. Formados a partir da combust?o
incompleta da mat?ria org?nica podem ser de origem natural ou antropog?nica.
Alguns materiais v?m sendo pesquisados com o objetivo de despoluir matrizes
ambientais que venham ser contaminadas por estes hidrocarbonetos. Dentre estes
materiais pesquisados v?rias argilas t?m sido empregadas, das quais se destaca a
vermiculita. Da fam?lia dos filossilicatos, a vermiculita por seu potencial hidrof?bico e
sua elevada ?rea superficial tem sido um utens?lio bastante utilizado na
descontamina??o de ?guas em processos de derramamento de ?leo. Contudo,
quando expandida esta perde sua capacidade hidrof?bica havendo a necessidade
do uso de um hidrofobizante para torn?-la organof?lica. Dentre os in?meros
hidrofobizantes pesquisados e utilizados o ?leo de linha?a foi o pioneiro. Neste
trabalho procurou-se avaliar a capacidade de remo??o de HPAs utilizando a
vermiculita hidrofobizada com ?leo de linha?a e tamb?m a parafina, para isto fez-se
uso do planejamento fatorial completo 24 como ferramenta principal para realiza??o
dos experimentos. Avaliou-se tamb?m a granulometria da argila (-20+48 e -48+80 #),
o percentual de hidrofobizante aplicado (5 e 10 %) e a salinidade da ?gua produzida
sintetizada em laborat?rio (35.000 e 55.000 ppm). A espectroscopia de fluoresc?ncia
molecular devido a sua sensibilidade e rapidez foi utilizada para verificar a
capacidade de adsor??o da argila, bem como a cromatografia gasosa serviu como
t?cnica auxiliar a fim de quantificar e identificar os HPAs presentes em solu??o. A fim
de caracterizar a vermiculita fez-se uso da fluoresc?ncia de raios X e difra??o de
raios X. O infravermelho e a termogravimetria foram essenciais para constatar a
hidrofobiza??o e a quantidade de recobrimento do argilomineral. De acordo com as
an?lises de fluoresc?ncia verificou-se que o ensaio 12 obteve o melhor resultado em
torno de 98 % de adsor??o dos compostos fluorescentes, contudo a elevada
salinidade, a menor granulometria, o maior percentual de hidrofobizante e o uso do
?leo de linha?a apresentaram maior efici?ncia na capacidade de remo??o destes
hidrocarbonetos, de acordo com a tend?ncia seguida pela an?lise dos fatores
principais do planejamento fatorial. Para verificar a capacidade de adsor??o da argila
utilizando um volume fixo de ?gua produzida sint?tica, usou-se como base o ensaio
12, nos seus respectivos n?veis e fatores. Deste modo, observou-se que ap?s a
adi??o de aproximadamente 1 ? litro de solu??o de ?gua produzida sint?tica, cerca
de 300 vezes o seu volume em massa, a vermiculita foi capaz de adsorver 80 % das
esp?cies fluorescentes presentes em solu??o
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