Thesis (M.S.)--Florida State University, 2005. / Advisor: Dr. Igor Alabugin, Florida State University, College of Arts and Sciences, Dept. of Chemistry and Biochemistry. Title and description from dissertation home page (viewed Sept. 19, 2005). Document formatted into pages; contains xv, 123 pages. Includes bibliographical references.

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O objetivo principal deste estudo foi determinar a origem da inibição do processo foto-Fenton [Fe(II)/Fe(III), H2O2, luz UV] pelo íon cloreto. Um estudo das reações primárias da etapa fotocatalítica do processo foto-Fenton por fotólise por pulso de laser na presença de NaCl mostrou que a inibição reflete: i) fotólise competitiva dos complexos Fe(Cl)2+ e Fe(Cl)2+; ii) captura do radical hidroxila (dependente do pH) pelo íon cloreto. Esses dois processos formam o ânion radical menos reativo Cl2•- em lugar do radical HO•-, provocando uma progressiva inibição da reação de degradação com a diminuição do pH. Modelagem cinética destes resultados previa que a manutenção do pH em 3,0 durante a fotodegradação evitaria a formação do Cl2•-, o que foi confirmada através de experimentos de fotodegradação do fenol e da gasolina em meio aquoso na presença de NaCl. Por outro lado, na degradação do fenol pela reação térmica de Fenton [Fe(II)/Fe(III), H2O2], o radical hidroxila não parece ter um papel muito importante. A degradação térmica não foi inibida pela presença de íon cloreto e a cinética de mineralização do fenol pela reação térmica de Fenton é indistinguível da degradação do fenol pelo processo foto-Fenton inibido por NaCl. Isso sugere que a reação proposta por Hamilton, isto é, a redução de Fe(III) a Fe(II) por catecol (o principal intermediário inicial da oxidação do fenol) na presença de H2O2, é o mecanismo principal de catálise da reação térmica de Fenton no nosso sistema. / The principal objective of the present study was to determine the origin of the inhibition of the photo-Fenton process [Fe(II)/Fe(III), H2O2, UV light] by chloride ion. A laser flash photolysis study of the primary reactions involved in the photocatalytic step of the photo-Fenton process in the presence of NaCl demonstrated that the inhibition reflects: i) competitive photolysis of the complexes Fe(Cl)2+ and Fe(Cl)2+; ii) pH-dependent sequestration of the hydroxyl radical by chloride ion. Both processes form the less reactive radical anion Cl2•- instead of HO•, resulting in a progressive inhibition of the degradation with decreasing reaction pH. Kinetic modeling of these results predicted that maintaining the pH at 3.0 throughout the reaction should prevent the formation of Cl2•-, a prediction confirmed experimentally for the photodegradation of phenol and gasoline. In contrast, in the degradation of phenol via the thermal Fenton reaction [Fe(II)/Fe(III), H2O2], the hydroxyl radical does not appear to play a very important role. Thus, the thermal degradation is not inhibited by chloride ion and the kinetics of mineralization of phenol by the thermal Fenton reaction are indistinguishable from those for degradation of phenol in the photo-Fenton reaction inhibited by NaCl. This suggests that the reaction proposed by Hamilton, i.e., reduction of Fe(III) to Fe(II) by catechol (the major initial intermediate in the oxidation of phenol) in the presence of H2O2, is the principal catalytic mechanism operative in the thermal Fenton reaction in our system.

Thesis (M.S.)--Florida State University, 2005. / Advisor: Dr. Marie E. Krafft, Florida State University, College of Arts and Sciences, Dept. of Chemistry and Biochemistry. Title and description from dissertation home page (viewed Sept. 19, 2005). Document formatted into pages; contains 147 pages. Includes bibliographical references.

O objetivo principal deste estudo foi determinar a origem da inibição do processo foto-Fenton [Fe(II)/Fe(III), H2O2, luz UV] pelo íon cloreto. Um estudo das reações primárias da etapa fotocatalítica do processo foto-Fenton por fotólise por pulso de laser na presença de NaCl mostrou que a inibição reflete: i) fotólise competitiva dos complexos Fe(Cl)2+ e Fe(Cl)2+; ii) captura do radical hidroxila (dependente do pH) pelo íon cloreto. Esses dois processos formam o ânion radical menos reativo Cl2•- em lugar do radical HO•-, provocando uma progressiva inibição da reação de degradação com a diminuição do pH. Modelagem cinética destes resultados previa que a manutenção do pH em 3,0 durante a fotodegradação evitaria a formação do Cl2•-, o que foi confirmada através de experimentos de fotodegradação do fenol e da gasolina em meio aquoso na presença de NaCl. Por outro lado, na degradação do fenol pela reação térmica de Fenton [Fe(II)/Fe(III), H2O2], o radical hidroxila não parece ter um papel muito importante. A degradação térmica não foi inibida pela presença de íon cloreto e a cinética de mineralização do fenol pela reação térmica de Fenton é indistinguível da degradação do fenol pelo processo foto-Fenton inibido por NaCl. Isso sugere que a reação proposta por Hamilton, isto é, a redução de Fe(III) a Fe(II) por catecol (o principal intermediário inicial da oxidação do fenol) na presença de H2O2, é o mecanismo principal de catálise da reação térmica de Fenton no nosso sistema. / The principal objective of the present study was to determine the origin of the inhibition of the photo-Fenton process [Fe(II)/Fe(III), H2O2, UV light] by chloride ion. A laser flash photolysis study of the primary reactions involved in the photocatalytic step of the photo-Fenton process in the presence of NaCl demonstrated that the inhibition reflects: i) competitive photolysis of the complexes Fe(Cl)2+ and Fe(Cl)2+; ii) pH-dependent sequestration of the hydroxyl radical by chloride ion. Both processes form the less reactive radical anion Cl2•- instead of HO•, resulting in a progressive inhibition of the degradation with decreasing reaction pH. Kinetic modeling of these results predicted that maintaining the pH at 3.0 throughout the reaction should prevent the formation of Cl2•-, a prediction confirmed experimentally for the photodegradation of phenol and gasoline. In contrast, in the degradation of phenol via the thermal Fenton reaction [Fe(II)/Fe(III), H2O2], the hydroxyl radical does not appear to play a very important role. Thus, the thermal degradation is not inhibited by chloride ion and the kinetics of mineralization of phenol by the thermal Fenton reaction are indistinguishable from those for degradation of phenol in the photo-Fenton reaction inhibited by NaCl. This suggests that the reaction proposed by Hamilton, i.e., reduction of Fe(III) to Fe(II) by catechol (the major initial intermediate in the oxidation of phenol) in the presence of H2O2, is the principal catalytic mechanism operative in the thermal Fenton reaction in our system.

Made available in DSpace on 2014-06-11T19:23:07Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-02Bitstream added on 2014-06-13T20:29:55Z : No. of bitstreams: 1 cremonini_ccr_me_botfm.pdf: 1144679 bytes, checksum: bf9c1e1e39c197477cae8519b0e360ce (MD5) / Fundação Pio Xii - Barretos / Avaliar a ocorrência e a gravidade das reações adversas agudas (RAA) com o uso do meio de contraste iodado iônico e não-iônico nos pacientes submetidos ao exame de tomografia computadorizada (TC) em hospital nacional terciário oncológico e avaliar neoplasia como possível risco para RAA. Secundariamente, avaliar o impacto do uso seletivo do meio de contraste iodado nos custos. Pacientes submetidos à TC com contraste iodado entre outubro de 2007 e agosto de 2008 foram avaliados quanto à ocorrência e à gravidade das reações adversas agudas aos meios de contrastes iônicos e nãoiônicos. As reações foram categorizadas em leve, moderada ou grave de acordo com o tipo dos sinais e sintomas e classificadas como agudas pelo tempo de ocorrência, desde o momento da injeção até 30 minutos após. Os testes do quiquadrado e exato de Fisher foram utilizados para análise estatística da ocorrência de RAA em relação às variáveis de gênero e idade. O estudo foi aprovado pelo Comitê de Ética local e o Termo de Consentimento Livre Esclarecido foi obtido. Houve 78 RAA ao contraste iodado iônico e 11 ao não-iônico, com uma ocorrência global de 3,3% (78/2.339) e 0,5% (11/2.216), respectivamente. A maioria das reações foi classificada como leve em ambos os grupos, representando 91% (71) no grupo iônico e 81,8% (9) no grupo não-iônico. As demais reações foram do tipo moderada não havendo nenhuma reação grave. Em relação ao início das RAA, 71% e 73% (iônico e não-iônico) ocorreram nos primeiros 5 minutos. A freqüência de RAA no grupo em que recebeu contraste iônico foi maior no sexo feminino (p < 0,001). No grupo não-iônico não houve diferença estatisticamente significativa entre os sexos (p = 1,0). Não houve associação entre a presença de reação aguda e as faixas... / To evaluate the occurrence and severity of acute adverse reactions (AAR) to iodinated ionic and non-ionic contrast media in patients undergoing computerized tomography (CT) at a national tertiary cancer hospital and to evaluate neoplasm as a possible risk for AAR. Secondly, to assess the impact of selective use of iodinated contrast agent costs. Patients who underwent contrast-enhanced CT between October 2007 and August 2008 were evaluated for the presence and severity of acute adverse reactions to ionic and non-ionic contrast media. The reactions were categorized as mild, moderate or severe according to the type of signs and symptoms and classified as acute by the time of occurrence, from the time of the injection up to 30 minutes afterwards. The chi-square and Fisher’s exact were used for statistical analysis of the occurrence of AAR for the variables of gender and age. The study was approved by the local Ethics Committee and informed consent was obtained. There were 78 AAR to ionic iodinated contrast and 11 to non-ionic, with an overall occurrence of 3.3% (78/2339) and 0.5% (11/2216), respectively. Most reactions were classified as mild in both groups, representing 91% (71) in the ionic group and 81.8% (9) in the non-ionic group. All other reactions were moderate and there were no severe reactions. Regarding onset of AAR, 71% and 73% (ionic and non-ionic group) occurred in the first five minutes. The occurrence of AAR in the group who received ionic contrast was higher in females (p <0.001). As for the non-ionic group, there was no significant statistical difference between genders (p = 1.0). There was no association between the presence of acute reaction and the age groups of the population in the ionic contrast group. For the non-ionic group, no statistical analysis was performed as the sample was deemed reduced. Among... (Complete abstract click electronic access below)

Orientador: Euclides Timótio da Rocha / Banca: Fabiano Rubião Lucchesi / Banca: Jorge Elias Junior / Resumo: Avaliar a ocorrência e a gravidade das reações adversas agudas (RAA) com o uso do meio de contraste iodado iônico e não-iônico nos pacientes submetidos ao exame de tomografia computadorizada (TC) em hospital nacional terciário oncológico e avaliar neoplasia como possível risco para RAA. Secundariamente, avaliar o impacto do uso seletivo do meio de contraste iodado nos custos. Pacientes submetidos à TC com contraste iodado entre outubro de 2007 e agosto de 2008 foram avaliados quanto à ocorrência e à gravidade das reações adversas agudas aos meios de contrastes iônicos e nãoiônicos. As reações foram categorizadas em leve, moderada ou grave de acordo com o tipo dos sinais e sintomas e classificadas como agudas pelo tempo de ocorrência, desde o momento da injeção até 30 minutos após. Os testes do quiquadrado e exato de Fisher foram utilizados para análise estatística da ocorrência de RAA em relação às variáveis de gênero e idade. O estudo foi aprovado pelo Comitê de Ética local e o Termo de Consentimento Livre Esclarecido foi obtido. Houve 78 RAA ao contraste iodado iônico e 11 ao não-iônico, com uma ocorrência global de 3,3% (78/2.339) e 0,5% (11/2.216), respectivamente. A maioria das reações foi classificada como leve em ambos os grupos, representando 91% (71) no grupo iônico e 81,8% (9) no grupo não-iônico. As demais reações foram do tipo moderada não havendo nenhuma reação grave. Em relação ao início das RAA, 71% e 73% (iônico e não-iônico) ocorreram nos primeiros 5 minutos. A freqüência de RAA no grupo em que recebeu contraste iônico foi maior no sexo feminino (p < 0,001). No grupo não-iônico não houve diferença estatisticamente significativa entre os sexos (p = 1,0). Não houve associação entre a presença de reação aguda e as faixas... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: To evaluate the occurrence and severity of acute adverse reactions (AAR) to iodinated ionic and non-ionic contrast media in patients undergoing computerized tomography (CT) at a national tertiary cancer hospital and to evaluate neoplasm as a possible risk for AAR. Secondly, to assess the impact of selective use of iodinated contrast agent costs. Patients who underwent contrast-enhanced CT between October 2007 and August 2008 were evaluated for the presence and severity of acute adverse reactions to ionic and non-ionic contrast media. The reactions were categorized as mild, moderate or severe according to the type of signs and symptoms and classified as acute by the time of occurrence, from the time of the injection up to 30 minutes afterwards. The chi-square and Fisher's exact were used for statistical analysis of the occurrence of AAR for the variables of gender and age. The study was approved by the local Ethics Committee and informed consent was obtained. There were 78 AAR to ionic iodinated contrast and 11 to non-ionic, with an overall occurrence of 3.3% (78/2339) and 0.5% (11/2216), respectively. Most reactions were classified as mild in both groups, representing 91% (71) in the ionic group and 81.8% (9) in the non-ionic group. All other reactions were moderate and there were no severe reactions. Regarding onset of AAR, 71% and 73% (ionic and non-ionic group) occurred in the first five minutes. The occurrence of AAR in the group who received ionic contrast was higher in females (p <0.001). As for the non-ionic group, there was no significant statistical difference between genders (p = 1.0). There was no association between the presence of acute reaction and the age groups of the population in the ionic contrast group. For the non-ionic group, no statistical analysis was performed as the sample was deemed reduced. Among... (Complete abstract click electronic access below) / Mestre

Nous ne sommes pas réalistes si on affirme qu’un locuteur peut parler ou maitriser une langue parfaitement. Il est vrai qu’un locuteur peut maitriser honorablement les règles linguistiques, pourtant cognitivement parlant, cela ne signifie pas trop. Les relations cognitives qu’on entretient avec les langues du monde dépassent la dimension linguistique amplement analysée aux manuels scolaires. Parler une langue veut dire être capable d’exister dans cette langue, en ce sens que son être y est inscrit. On est dirigé par son intuition linguistique pour s’exprimer spontanément et conformément au génie de cette langue. Toutefois, toutes les relations cognitives qu’on entretient avec les langues du monde, sont assujettis au temps et aux circonstances de vie; elles peuvent soit évoluer, détériorer mais toujours se modifier. En ce sens, le locuteur est un locuteur inachevé, un être inachevé, perfectible à l’infini. Ceci est une des principes du cadre théorique que nous adoptons à cette thèse; la théorie de la néoténie linguistique. Il s’agit d’une étude scientifique des langues et de leur appropriation par les locuteurs, dans laquelle la dichotomie, faits de langue/faits d’appropriation y sont traités comme une entité.Dans cette étude nous utilisons le cade théorique de la néoténie linguistique et en adoptant ses termes et notions, nous examinons le cas intéressent du locuteur chypriote-grec. Un locuteur dont le paysage linguistique est au moins compliqué. La première (chronologiquement) langue de ce locuteur est le dialecte chypriote-grec, mais puis pendant sa scolarisation on doit s’exprimer et écrire en grec moderne. Certains locuteurs affirment que dans leur vie quotidienne ils parlent le grec moderne, des autres le chypriote-grec et en même temps les chercheurs semblent être indécis sur ce sujet. À cela s’ajoute la présence de facto du moins trois encore langues; l’anglais, le français et le turc. Avec la théorie de la néoténie linguistique, nous essayons de fournir d’attribuer nous aussi à la divergence du parler local du grec moderne et d’examiner les relations cognitives de ses locuteurs avec les langues trouvées dans leur environnement linguistique. / It is not realistic to claim that a speaker can use a language perfectly or that he /she has an excellent knowledge of whichever language, like many speakers like to claim when asked. It is true that a speaker may have some excellent linguistic skills, however cognitively speaking, this doesn’t say much. The cognitive relations that we maintain with the world’s languages are far beyond the linguistic dimension, excessively found in textbooks. Speaking a language means being able to exist in that language, in the sense that our being is there registered. We are led by our linguistic intuition to express ourselves and we do it spontaneously with respect to each language’s boundaries. However, all cognitive and linguistic relations we maintain with the world’s languages are subject to be modified in time; either evolve, deteriorate but they always change, that depends on the life’s circumstances. In that sense the speaker is considered an uncompleted being that is perfectible ad infinitum. This is one of the principles that advocates the theoretical framework that we adopt in this study. The theory of linguistic neoteny is a scientific study of the languages and their appropriation by the speakers, where the dichotomy linguistic events / appropriation facts is not considered as two entities but as one.In this study, using the theoretical framework of linguistic neoteny and adopting some new terms and concepts, we examine the interesting case of the Greek Cypriot speaker. A speaker, whose linguistic landscape, is at least complicated. These speakers’ first (chronologically) language is the Greek Cypriot dialect, but then with the school enrollment they have to speak and write in Modern Greek. Some speakers claim that in their everyday life, they speak Greek, some others that they speak Cypriot, while researchers also seem to be undecided. To this is added the de facto presence of at least another three languages in this speaker’s linguistic environment; English, French and Turkish. Using the theory of linguistic neoteny we seek to provide some evidence concerning the divergence of the dialect from the Modern Greek language and examine the cognitive relations the Greek Cypriot speakers maintain with all the languages found in their linguistic environment.