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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Visselblåsaren Edward Snowden i olika medieformer / The Portrait of Whistleblower Edward Snowden In Various Media Forms

Persdotter, Fanny January 2020 (has links)
This essay discusses the portrait of the whistleblower Edward Joseph Snowden in different media forms. Edward Snowden, the NSA employee who in June 2103 revealed NSA’s secret global surveillance system in the newspapers The Guardian UK, The Washington Post and The New York times, has been portrayed in various types of media such as news articles, film, documentary and self-biography. With references to the communication theories re-mediation and storytelling, this thesis examines which components are used in these different types of media to portray Snowden and how the perspectives differ. It also focuses on which traits that defines a hero and a traitor. And if the typical whistleblower is a hero or a telltale. The information is very similar. Which we can expect depends on that the information has not been remediated very far from its original source. What sets the portraits apart is the perspective and who and what Edward Snowden is shown in the opposite to. For example, in the news articles, Snowden is always talked about in reference to the government, and how he betrayed the loyalty of the government and his oaths. While in the rest of the media forms, produced by and representing the public, he is presented as the hero who took the integrity of the public and his own beliefs in his own hands and stood up against the government. Both sides can in substance prove their point, it is all about the perspective and whose side the audience and the authors are on.
12

The Right to Privacy In The War On Terror: Constitutional Questions In Eavesdropping By The U.S. Government

Harbin, Christopher 01 January 2007 (has links)
In October 2001 , President George W. Bush issued an executive order authorizing the National Security Agency (NSA) to conduct secret wiretapping of telephone communications between U.S. citizens and terrorist suspects overseas in the wake of the September 11th terrorist attacks. The program, later called the Terrorist Surveillance Program (TSP), remained secret until December 2005, when the New York Times revealed the existence of the TSP. In January 2006, the American Civil Liberties Union (ACLU) filed suit in the United States District Court for the Eastern District of Michigan, claiming that the NSA's surveillance program violated the First and Fourth Amendments of the U.S. Constitution, as well as the separation of powers doctrine. The government argued that the program met constitutional scrutiny under the "special needs" doctrine warrant exception. Additionally, the Bush administration asserted that Congress specifically gave the President permission to authorize the program by its passing the Authorization for Use of Military Force (AUMF). This thesis analyzes the constitutionality of the domestic surveillance program by discussing the constitutional questions that the NSA's program elicits under the Fourth Amendment. Also, this thesis reviews the legality of the TSP under the Foreign Intelligence Surveillance Act (FISA). After an analysis of the Supreme Court's jurisprudence in Fourth Amendment, privacy, and eavesdropping cases, this thesis concludes that the NSA' s warrantless eavesdropping program most likely violates the Fourth Amendment and the separation of powers doctrine. Further, this thesis asserts that the TSP is illegal under the FISA and that the Executive lacks statutory authorization.
13

Estudo computacional de [2.2]ciclofanos / Computational Study of [2.2]cyclophanes

Caramori, Giovanni Finoto 01 September 2006 (has links)
Neste trabalho foram estudados computacionalmente os [2.2]ciclofanos ([2.2]paraciclofano (1), anti-[2.2]metaciclofano (2a), sin-[2.2]metaciclofano (2b) e [2.2]metaparaciclofano (3)), que são os [2n]ciclofanos mais simples, contendo dois anéis fenílicos conectados por duas pontes etilênicas. Os ciclofanos têm apresentado inúmeras aplicações importantes, podendo atuar como auxiliares em sínteses assimétricas e como catalisadores que simulam funções enzimáticas, apresentando seletividade em relação aos substratos. Eles são empregados tanto em químicab supramolecular quanto em áreas biomédicas. Estudos que empregam ressonância de spin eletrônico ou que investigam propriedades ópticas não-lineares dos [2.2]ciclofanos indicam que os mesmos apresentam interações transanulares, que ocorrem através de recobrimento direto entre orbitais pertencentes a anéis diferentes, through-space, ou através de recobrimento entre orbitais dos anéis e das pontes, through-bond. As interações transanulares possuem um papel fundamental na química dos ciclofanos, alterando o comportamento reacional destes compostos e as transições espectroscópicas. Apesar dos métodos de preparação de ciclofanos, desde os mais simples aos mais complexos, serem intensamente investigados, estudos computacionais, que busquem compreender as correlações entre tensão e aromaticidade, estrutura eletrônica e o mecanismo de ocorrência das interações transanulares, são raramente encontrados na literatura. Desse modo, o objetivo deste trabalho foi estudar as interações transanulares, bem como correlacionar as diferenças estruturais, a tensão sobre anéis e pontes, cargas atômicas, aromaticidade e os deslocamentos químicos, não apenas para os isômeros dos [2.2]ciclofanos, mas também seus derivados fluorados (perfluoração de um dos anéis dos [2.2]ciclofanos), bem como avaliar os efeitos de diversos substituintes (CN, Cl, C=O, NH2 e NO2) e da protonação na estrutura eletrônica do isômero [2.2]paraciclofano. As otimizações de geometria de 1, realizadas com diferentes métodos e conjuntos de funções de base, mostraram que os modelos MP2/6-31+G(d,p) e B3PW91/6-31+G(d,p) fornecem os melhores resultados em comparação com os dados de raios-x. Buscas conformacionais mostraram que 2a e 2b são confôrmeros com energias diferentes e que 3 possui dois confôrmeros degenerados. As energias relativas e de tensão das pontes, seguiram a mesma ordem, indicando que a tensão sobre as pontes e a repulsão entre as nuvens ? dos anéis aromáticos são determinantes para a estabilidade dos [2.2]ciclofanos. As reações isodésmicas indicaram que os anéis comportam-se como absorvedores de tensão. NICS e HOMA mostraram que apesar das perdas de planaridade dos anéis a aromaticidade é mantida. O método NBO confirmou que todos os [2.2]ciclofanos apresentam interações through-bond, mas apenas 2a e 2b apresentaram interações through-space significantes. A análise AIM mostrou que as interações transanulares observadas são do tipo camada fechada (iônica ou ligação de hidrogênio) e que estabilizam os [2.2]ciclofanos. Para os derivados fluorados as principais alterações geométricas observadas foram para os diedros das pontes. As reações isodésmicas revelaram que as tensões das pontes e as energias relativas são afetadas pela fluoração. Além disso, os anéis dos isômeros fluorados absorvem mais tensão que os anéis dos isômeros não fluorados. NICS e HOMA mostraram que a substituição por flúor aumenta a aromaticidade dos [2.2]ciclofanos. A análise NBO indicou que a perfluoração aumentou o número e a intensidade das interações through-space, mas as mesmas ficaram restritas principalmente aos derivados fluorados de 2a e 2b. A mesma análise evidenciou que há uma conjugação dos pares de elétrons dos átomos de flúor com o sistema ?. Por outro lado, a análise AIM sugeriu que a substituição não aumenta o número de interações through-space, mas confirmou a conjugação dos pares de elétrons dos átomos de flúor. Os demais substituintes empregados afetam os parâmetros geométricos do [2.2]paraciclofano (1) de maneira diferenciada. A análise particionada das reações isodésmicas mostrou que as tensões nos anéis e nas pontes dependem não apenas do substituinte empregado, mas também da posição da substituição. NICS e HOMA indicaram que a aromaticidade no anel não-substituído dos derivados substituídos é maior que em 1. A análise NBO revelou que a substituição e a protonação aumentam a ocorrência de interações transanulares through-space. O método AIM indicou a presença de interações transanulares apenas para o derivado substituído com NH2 e CN e para a espécie protonada. No entanto, tais interações apresentaram características de interações de camada fechada. com pequenas estabilizações. As cargas atômicas e os deslocamentos químicos confirmaram as mudanças na densidade eletrônica, observadas através do método AIM. / In this work, the [2.2]cyclophanes ([2.2]paracyclophane (1), anti-[2.2]metacyclophane (2a), syn-[2.2]metacyclophane (2b) e [2.2]metaparacyclophane (3)), which are the simplest [2n] cyclophanes that contain two phenyl rings connected by two ethanediyl linkages, were studied computationally. Cyclophanes have presented several important applications, such as auxiliary in asymmetric synthesis, catalysts that simulate enzymatic functions, presenting selectivity in relation to the substrates. They are employed either in supramolecular chemistry or in biomedical areas. Studies that apply electron spin resonance or that investigate the non-linear optical properties of [2.2]cyclophanes, indicate that these compounds present transannular interactions, which occur through direct overlap of orbitals lying in different rings, throughspace, or through overlap between orbitals from rings and bridges, through-bond. The transannular interactions have a fundamental role in cyclophane chemistry, changing the reactional behavior of these compounds, and the spectroscopic transitions. Despite the fact that the well known methods of preparation, from the simplest to the most complex cyclophanes, have been studied intensively, computational studies that intent to comprehend the correlations between tension and aromaticity, electronic structure, and the mechanism of the transannular interactions are rarely found in the literature. Therefore, the aim of this work was not only to study the transannular interactions, correlating the structural differences, tension in rings and bridges, atomic charges, aromaticity, and chemical shifts of the [2.2]cyclophanes isomers but also to extent a similar treatment to the fluorinated derivatives. In addition, the effects of substituents such as (CN, Cl, C=O, NH2, and NO2) and the protonation on the electronic structure of [2.2]paracyclophane were also evaluated. The geometry optimizations of 1, carried out by using different methods and basis set, showed that the models MP2/6-31+G(d,p) and B3PW91/6-31+G(d,p) provide the best results in comparison with the x-ray data. Conformational searches showed that 2a and 2b are the conformers that present the same energy and the isomer 3 has two degenerated conformers. The strain energies of the bridges followed the same tendency as the relative energies, indicating that the tension on the bridges and the repulsions between the ? clouds of the aromatic rings are the key factors that determine the [2.2]cyclophane stabilities. The isodesmic reactions indicated that the rings are absorbents of tension. NICS and HOMA showed that the aromaticity of the rings is preserved despite the changes on the planarity. The NBO method confirmed that all [2.2]cyclophanes present through-bond interactions, but only 2a and 2b exhibit noteworthy through-space interactions. The AIM analysis pointed out that the transannular interactions behave as closed shell interactions (ionic or hydrogen bond), stabilizing the [2.2]cyclophanes. The main geometric changes, observed to the fluorinated derivatives, were those related with the dihedral angle of bridges. The isodesmic reactions pointed out that the tensions of bridges and the relative energies are affected by the fluorination. In addition, the fluorinated rings absorb more tension than the non-fluorinated rings. NICS and HOMA showed that the substitution by fluorine increases the aromaticity of the [2.2]cyclophanes. The NBO analysis indicated that the number of through-space interactions increase with the fluorination, but it is restrict to the derivatives of 2a and 2b. In addition, the same analysis pointed out a conjugation of the fluorine lone pairs with the ? system. On the other hand, the AIM analysis suggested that the substitution do not increase the number of through-space interactions, but confirmed the conjugation of the fluorine lone pairs. The other substituents can affect the geometric parameter of 1 noticeably. The partitioned analysis of isodesmic reactions showed that the tensions in bridges and rings not only depend on the substituents employed but also on the position of substitution. NICS and HOMA pointed out that the aromaticity is bigger in the non-substituted rings of [2.2]paracyclophane derivatives than in 1. The NBO analysis showed that the substitution and protonation increase the number of through-space interactions. AIM method indicated the transannular interactions occur only to the derivate substituted by NH2 and CN, and to the protonated specie. However, these interactions presented features of closed shell interactions with small stabilizations. The atomic charges and the chemical shifts confirmed the changes of the electronic density, observed through the AIM method.
14

As ligações de hidrogênio e o efeito do substituinte - Influência na ressonância e aromaticidade de cátions e ácidos orgânicos / Hydrogen bonds and substituent effect - Influence in the resonance and aromaticity of the cations and organic acids

Parreira, Renato Luis Tâme 11 July 2006 (has links)
A natureza das ligações de hidrogênio e a influência destas interações na estrutura eletrônica de complexos neutros, catiônicos, aniônicos e radicalares foi estudada utilizando-se análises geométricas, energéticas, eletrônicas e topológicas. Inicialmente, verificaram-se alterações na aromaticidade do cátion pirílio após a complexação com uma a três moléculas de água. Tais complexos foram ainda estudados em meio reacional com constante dielétrica igual a da água com o emprego do modelo PCM (Polarizable Continuum Model). Adicionalmente, os efeitos da hidroxilação na estrutura eletrônica dos cátions benzopirílio e flavílio foram considerados. Posteriormente, analisaram-se os efeitos das fortes ligações de hidrogênio na ressonância do grupo carboxila em complexos formados entre o radical hidroperoxil e os ácidos fórmico, acético e trifluoroacético. Como extensão desse trabalho, estudos envolvendo complexos obtidos com e sem restrições na otimização de geometria possibilitaram obter informações a respeito da ressonância dos grupos carboxila e carboxilato quando o fluoreto de hidrogênio interage linear ou perpendicularmente com todos os átomos do ácido fórmico e do ânion formiato. O desenvolvimento das atividades supracitadas compreendeu a análise da função de onda pelos métodos NBO (Natural Bond Orbital), NSA (Natural Steric Analysis), NRT (Natural Resonance Theory) e AIM (Atoms in Molecules). As alterações em parâmetros geométricos e nas cargas atômicas foram consideradas. Uma análise energética foi realizada com o emprego do método de decomposição de energia proposto por Xantheas. As freqüências vibracionais e a intensidade das bandas do estiramento do grupo X-H, doador da ligação de hidrogênio, foram analisadas. As densidades de spin para os complexos radicalares também foram obtidas. A influência das ligações de hidrogênio e o efeito do substituinte na aromaticidade dos cátions foram verificados com o emprego dos métodos e índices NICS (Nucleus Independent Chemical Shifts), HOMA (Harmonic Oscillator Model of Aromaticity), HOSE (Harmonic Oscillator Stabilization Energy) e PDI (para-Delocalization Index). Os cálculos foram efetuados com os modelos B3LYP/6-31+G(d,p), B3LYP/6-311++G(3df,3pd) e UB3LYP/6-311++G(3df,3pd). Ocasionalmente, outras funções de base (EPR-III e cc-pVDZ), assim como o método MP2, foram utilizados para testar a confiabilidade dos resultados obtidos. As interações intermoleculares pouco alteraram a estrutura eletrônica e a aromaticidade do cátion pirílio. Analogamente, a substituição de um átomo de hidrogênio por um grupo hidroxila em diversas posições dos cátions benzopirílio e flavílio também não provocou modificações muito significativas na estrutura eletrônica desses cátions, embora tenha se verificado uma dependência da aromaticidade com a posição da hidroxila. Por outro lado, a distorção geométrica associada às ligações de hidrogênio foram responsáveis pelo incremento ou diminuição da ressonância do grupo carboxila nos ácidos fórmico, acético, trifluoroacético e do grupo carboxilato no ânion formiato. Os efeitos dos grupos doador e sacador de elétrons na estabilização dos complexos radicalares foram evidenciados. Adicionalmente, pode-se atribuir um caráter covalente parcial em algumas ligações de hidrogênio. / The nature of hydrogen bonds and their influence on electronic structure of neutral, cationic, anionic, and radical complexes was studied by using geometric, energetic, electronic, and topological analysis. The changes in aromaticity of the pyrylium cation upon complexation with one up to three water molecules were investigated. The PCM (Polarizable Continuum Model) model was employed to study the pyrylium-water complexes in a water reaction medium. In addition, the effects of hydroxylation on electronic structure of the benzopyrylium and flavilium cations were also considered. In addition, the effects of strong hydrogen bonds on carboxyl group resonance in the complexes formed between the hydroperoxyl radical and formic, acetic, and trifluoroacetic acids were analyzed. In extension of this work, studies including complexes, obtained with and without geometric restrictions, provided information about the resonance of the carboxyl and carboxylate groups when the hydrogen fluoride interacts, linear or perpendicularly, with all atoms of formic acid and formate anion. The analysis of the wavefunction by using NBO (Natural Bond Orbital), NSA (Natural Steric Analysis), NRT (Natural Resonance Theory), and AIM (Atoms in Molecules) methods was necessary to the development of the above mentioned activities. The changes in geometric parameters and atomic charges were also considered. An energetic analysis of complexes was done with the energy decomposition method proposed by Xantheas. The vibrational frequencies and the intensity of the X-H (hydrogen bond donor group) stretching bands were studied. The spin densities for the radical complexes were also obtained. The Nucleus Independent Chemical Shifts (NICS), Harmonic Oscillator Model of Aromaticity (HOMA), HOSE (Harmonic Oscillator Stabilization Energy), and PDI (para-Delocalization Index) aromaticity criteria were employed to verify the hydrogen bond influence and the effect of hydroxylation in the aromaticity of the cations. The calculations were carried out by using B3LYP/6-31+G(d,p), B3LYP/6-311++G(3df,3pd), and UB3LYP/6-311++G(3df,3pd) models. Occasionally, other basis set (EPR-III and cc-pVDZ), as well as the MP2 method, were applied to test the accuracy of the results. The intermolecular interactions lead to small alterations in the electronic structure and aromaticity of pyrylium cation. Similarly, the substitution at different positions of the benzopyrylium and flavilium cations by a hydroxyl group does not cause significant changes in the electronic structure of these cations. However, a dependence of the hydroxyl group position on aromaticity was observed. On the other hand, for formic, acetic, trifluoroacetic acids, as well as for the formate anion, the resonance of the carboxyl and carboxylate groups is affected not only by the geometric distortions but also by the hydrogen bonds. The effects of the electron-donating and electron-withdrawing groups in the stabilization of radical complexes were characterized. Furthermore, a partial covalent character can be attributed to some hydrogen bonds.
15

As ligações de hidrogênio e o efeito do substituinte - Influência na ressonância e aromaticidade de cátions e ácidos orgânicos / Hydrogen bonds and substituent effect - Influence in the resonance and aromaticity of the cations and organic acids

Renato Luis Tâme Parreira 11 July 2006 (has links)
A natureza das ligações de hidrogênio e a influência destas interações na estrutura eletrônica de complexos neutros, catiônicos, aniônicos e radicalares foi estudada utilizando-se análises geométricas, energéticas, eletrônicas e topológicas. Inicialmente, verificaram-se alterações na aromaticidade do cátion pirílio após a complexação com uma a três moléculas de água. Tais complexos foram ainda estudados em meio reacional com constante dielétrica igual a da água com o emprego do modelo PCM (Polarizable Continuum Model). Adicionalmente, os efeitos da hidroxilação na estrutura eletrônica dos cátions benzopirílio e flavílio foram considerados. Posteriormente, analisaram-se os efeitos das fortes ligações de hidrogênio na ressonância do grupo carboxila em complexos formados entre o radical hidroperoxil e os ácidos fórmico, acético e trifluoroacético. Como extensão desse trabalho, estudos envolvendo complexos obtidos com e sem restrições na otimização de geometria possibilitaram obter informações a respeito da ressonância dos grupos carboxila e carboxilato quando o fluoreto de hidrogênio interage linear ou perpendicularmente com todos os átomos do ácido fórmico e do ânion formiato. O desenvolvimento das atividades supracitadas compreendeu a análise da função de onda pelos métodos NBO (Natural Bond Orbital), NSA (Natural Steric Analysis), NRT (Natural Resonance Theory) e AIM (Atoms in Molecules). As alterações em parâmetros geométricos e nas cargas atômicas foram consideradas. Uma análise energética foi realizada com o emprego do método de decomposição de energia proposto por Xantheas. As freqüências vibracionais e a intensidade das bandas do estiramento do grupo X-H, doador da ligação de hidrogênio, foram analisadas. As densidades de spin para os complexos radicalares também foram obtidas. A influência das ligações de hidrogênio e o efeito do substituinte na aromaticidade dos cátions foram verificados com o emprego dos métodos e índices NICS (Nucleus Independent Chemical Shifts), HOMA (Harmonic Oscillator Model of Aromaticity), HOSE (Harmonic Oscillator Stabilization Energy) e PDI (para-Delocalization Index). Os cálculos foram efetuados com os modelos B3LYP/6-31+G(d,p), B3LYP/6-311++G(3df,3pd) e UB3LYP/6-311++G(3df,3pd). Ocasionalmente, outras funções de base (EPR-III e cc-pVDZ), assim como o método MP2, foram utilizados para testar a confiabilidade dos resultados obtidos. As interações intermoleculares pouco alteraram a estrutura eletrônica e a aromaticidade do cátion pirílio. Analogamente, a substituição de um átomo de hidrogênio por um grupo hidroxila em diversas posições dos cátions benzopirílio e flavílio também não provocou modificações muito significativas na estrutura eletrônica desses cátions, embora tenha se verificado uma dependência da aromaticidade com a posição da hidroxila. Por outro lado, a distorção geométrica associada às ligações de hidrogênio foram responsáveis pelo incremento ou diminuição da ressonância do grupo carboxila nos ácidos fórmico, acético, trifluoroacético e do grupo carboxilato no ânion formiato. Os efeitos dos grupos doador e sacador de elétrons na estabilização dos complexos radicalares foram evidenciados. Adicionalmente, pode-se atribuir um caráter covalente parcial em algumas ligações de hidrogênio. / The nature of hydrogen bonds and their influence on electronic structure of neutral, cationic, anionic, and radical complexes was studied by using geometric, energetic, electronic, and topological analysis. The changes in aromaticity of the pyrylium cation upon complexation with one up to three water molecules were investigated. The PCM (Polarizable Continuum Model) model was employed to study the pyrylium-water complexes in a water reaction medium. In addition, the effects of hydroxylation on electronic structure of the benzopyrylium and flavilium cations were also considered. In addition, the effects of strong hydrogen bonds on carboxyl group resonance in the complexes formed between the hydroperoxyl radical and formic, acetic, and trifluoroacetic acids were analyzed. In extension of this work, studies including complexes, obtained with and without geometric restrictions, provided information about the resonance of the carboxyl and carboxylate groups when the hydrogen fluoride interacts, linear or perpendicularly, with all atoms of formic acid and formate anion. The analysis of the wavefunction by using NBO (Natural Bond Orbital), NSA (Natural Steric Analysis), NRT (Natural Resonance Theory), and AIM (Atoms in Molecules) methods was necessary to the development of the above mentioned activities. The changes in geometric parameters and atomic charges were also considered. An energetic analysis of complexes was done with the energy decomposition method proposed by Xantheas. The vibrational frequencies and the intensity of the X-H (hydrogen bond donor group) stretching bands were studied. The spin densities for the radical complexes were also obtained. The Nucleus Independent Chemical Shifts (NICS), Harmonic Oscillator Model of Aromaticity (HOMA), HOSE (Harmonic Oscillator Stabilization Energy), and PDI (para-Delocalization Index) aromaticity criteria were employed to verify the hydrogen bond influence and the effect of hydroxylation in the aromaticity of the cations. The calculations were carried out by using B3LYP/6-31+G(d,p), B3LYP/6-311++G(3df,3pd), and UB3LYP/6-311++G(3df,3pd) models. Occasionally, other basis set (EPR-III and cc-pVDZ), as well as the MP2 method, were applied to test the accuracy of the results. The intermolecular interactions lead to small alterations in the electronic structure and aromaticity of pyrylium cation. Similarly, the substitution at different positions of the benzopyrylium and flavilium cations by a hydroxyl group does not cause significant changes in the electronic structure of these cations. However, a dependence of the hydroxyl group position on aromaticity was observed. On the other hand, for formic, acetic, trifluoroacetic acids, as well as for the formate anion, the resonance of the carboxyl and carboxylate groups is affected not only by the geometric distortions but also by the hydrogen bonds. The effects of the electron-donating and electron-withdrawing groups in the stabilization of radical complexes were characterized. Furthermore, a partial covalent character can be attributed to some hydrogen bonds.
16

Estudo computacional de [2.2]ciclofanos / Computational Study of [2.2]cyclophanes

Giovanni Finoto Caramori 01 September 2006 (has links)
Neste trabalho foram estudados computacionalmente os [2.2]ciclofanos ([2.2]paraciclofano (1), anti-[2.2]metaciclofano (2a), sin-[2.2]metaciclofano (2b) e [2.2]metaparaciclofano (3)), que são os [2n]ciclofanos mais simples, contendo dois anéis fenílicos conectados por duas pontes etilênicas. Os ciclofanos têm apresentado inúmeras aplicações importantes, podendo atuar como auxiliares em sínteses assimétricas e como catalisadores que simulam funções enzimáticas, apresentando seletividade em relação aos substratos. Eles são empregados tanto em químicab supramolecular quanto em áreas biomédicas. Estudos que empregam ressonância de spin eletrônico ou que investigam propriedades ópticas não-lineares dos [2.2]ciclofanos indicam que os mesmos apresentam interações transanulares, que ocorrem através de recobrimento direto entre orbitais pertencentes a anéis diferentes, through-space, ou através de recobrimento entre orbitais dos anéis e das pontes, through-bond. As interações transanulares possuem um papel fundamental na química dos ciclofanos, alterando o comportamento reacional destes compostos e as transições espectroscópicas. Apesar dos métodos de preparação de ciclofanos, desde os mais simples aos mais complexos, serem intensamente investigados, estudos computacionais, que busquem compreender as correlações entre tensão e aromaticidade, estrutura eletrônica e o mecanismo de ocorrência das interações transanulares, são raramente encontrados na literatura. Desse modo, o objetivo deste trabalho foi estudar as interações transanulares, bem como correlacionar as diferenças estruturais, a tensão sobre anéis e pontes, cargas atômicas, aromaticidade e os deslocamentos químicos, não apenas para os isômeros dos [2.2]ciclofanos, mas também seus derivados fluorados (perfluoração de um dos anéis dos [2.2]ciclofanos), bem como avaliar os efeitos de diversos substituintes (CN, Cl, C=O, NH2 e NO2) e da protonação na estrutura eletrônica do isômero [2.2]paraciclofano. As otimizações de geometria de 1, realizadas com diferentes métodos e conjuntos de funções de base, mostraram que os modelos MP2/6-31+G(d,p) e B3PW91/6-31+G(d,p) fornecem os melhores resultados em comparação com os dados de raios-x. Buscas conformacionais mostraram que 2a e 2b são confôrmeros com energias diferentes e que 3 possui dois confôrmeros degenerados. As energias relativas e de tensão das pontes, seguiram a mesma ordem, indicando que a tensão sobre as pontes e a repulsão entre as nuvens ? dos anéis aromáticos são determinantes para a estabilidade dos [2.2]ciclofanos. As reações isodésmicas indicaram que os anéis comportam-se como absorvedores de tensão. NICS e HOMA mostraram que apesar das perdas de planaridade dos anéis a aromaticidade é mantida. O método NBO confirmou que todos os [2.2]ciclofanos apresentam interações through-bond, mas apenas 2a e 2b apresentaram interações through-space significantes. A análise AIM mostrou que as interações transanulares observadas são do tipo camada fechada (iônica ou ligação de hidrogênio) e que estabilizam os [2.2]ciclofanos. Para os derivados fluorados as principais alterações geométricas observadas foram para os diedros das pontes. As reações isodésmicas revelaram que as tensões das pontes e as energias relativas são afetadas pela fluoração. Além disso, os anéis dos isômeros fluorados absorvem mais tensão que os anéis dos isômeros não fluorados. NICS e HOMA mostraram que a substituição por flúor aumenta a aromaticidade dos [2.2]ciclofanos. A análise NBO indicou que a perfluoração aumentou o número e a intensidade das interações through-space, mas as mesmas ficaram restritas principalmente aos derivados fluorados de 2a e 2b. A mesma análise evidenciou que há uma conjugação dos pares de elétrons dos átomos de flúor com o sistema ?. Por outro lado, a análise AIM sugeriu que a substituição não aumenta o número de interações through-space, mas confirmou a conjugação dos pares de elétrons dos átomos de flúor. Os demais substituintes empregados afetam os parâmetros geométricos do [2.2]paraciclofano (1) de maneira diferenciada. A análise particionada das reações isodésmicas mostrou que as tensões nos anéis e nas pontes dependem não apenas do substituinte empregado, mas também da posição da substituição. NICS e HOMA indicaram que a aromaticidade no anel não-substituído dos derivados substituídos é maior que em 1. A análise NBO revelou que a substituição e a protonação aumentam a ocorrência de interações transanulares through-space. O método AIM indicou a presença de interações transanulares apenas para o derivado substituído com NH2 e CN e para a espécie protonada. No entanto, tais interações apresentaram características de interações de camada fechada. com pequenas estabilizações. As cargas atômicas e os deslocamentos químicos confirmaram as mudanças na densidade eletrônica, observadas através do método AIM. / In this work, the [2.2]cyclophanes ([2.2]paracyclophane (1), anti-[2.2]metacyclophane (2a), syn-[2.2]metacyclophane (2b) e [2.2]metaparacyclophane (3)), which are the simplest [2n] cyclophanes that contain two phenyl rings connected by two ethanediyl linkages, were studied computationally. Cyclophanes have presented several important applications, such as auxiliary in asymmetric synthesis, catalysts that simulate enzymatic functions, presenting selectivity in relation to the substrates. They are employed either in supramolecular chemistry or in biomedical areas. Studies that apply electron spin resonance or that investigate the non-linear optical properties of [2.2]cyclophanes, indicate that these compounds present transannular interactions, which occur through direct overlap of orbitals lying in different rings, throughspace, or through overlap between orbitals from rings and bridges, through-bond. The transannular interactions have a fundamental role in cyclophane chemistry, changing the reactional behavior of these compounds, and the spectroscopic transitions. Despite the fact that the well known methods of preparation, from the simplest to the most complex cyclophanes, have been studied intensively, computational studies that intent to comprehend the correlations between tension and aromaticity, electronic structure, and the mechanism of the transannular interactions are rarely found in the literature. Therefore, the aim of this work was not only to study the transannular interactions, correlating the structural differences, tension in rings and bridges, atomic charges, aromaticity, and chemical shifts of the [2.2]cyclophanes isomers but also to extent a similar treatment to the fluorinated derivatives. In addition, the effects of substituents such as (CN, Cl, C=O, NH2, and NO2) and the protonation on the electronic structure of [2.2]paracyclophane were also evaluated. The geometry optimizations of 1, carried out by using different methods and basis set, showed that the models MP2/6-31+G(d,p) and B3PW91/6-31+G(d,p) provide the best results in comparison with the x-ray data. Conformational searches showed that 2a and 2b are the conformers that present the same energy and the isomer 3 has two degenerated conformers. The strain energies of the bridges followed the same tendency as the relative energies, indicating that the tension on the bridges and the repulsions between the ? clouds of the aromatic rings are the key factors that determine the [2.2]cyclophane stabilities. The isodesmic reactions indicated that the rings are absorbents of tension. NICS and HOMA showed that the aromaticity of the rings is preserved despite the changes on the planarity. The NBO method confirmed that all [2.2]cyclophanes present through-bond interactions, but only 2a and 2b exhibit noteworthy through-space interactions. The AIM analysis pointed out that the transannular interactions behave as closed shell interactions (ionic or hydrogen bond), stabilizing the [2.2]cyclophanes. The main geometric changes, observed to the fluorinated derivatives, were those related with the dihedral angle of bridges. The isodesmic reactions pointed out that the tensions of bridges and the relative energies are affected by the fluorination. In addition, the fluorinated rings absorb more tension than the non-fluorinated rings. NICS and HOMA showed that the substitution by fluorine increases the aromaticity of the [2.2]cyclophanes. The NBO analysis indicated that the number of through-space interactions increase with the fluorination, but it is restrict to the derivatives of 2a and 2b. In addition, the same analysis pointed out a conjugation of the fluorine lone pairs with the ? system. On the other hand, the AIM analysis suggested that the substitution do not increase the number of through-space interactions, but confirmed the conjugation of the fluorine lone pairs. The other substituents can affect the geometric parameter of 1 noticeably. The partitioned analysis of isodesmic reactions showed that the tensions in bridges and rings not only depend on the substituents employed but also on the position of substitution. NICS and HOMA pointed out that the aromaticity is bigger in the non-substituted rings of [2.2]paracyclophane derivatives than in 1. The NBO analysis showed that the substitution and protonation increase the number of through-space interactions. AIM method indicated the transannular interactions occur only to the derivate substituted by NH2 and CN, and to the protonated specie. However, these interactions presented features of closed shell interactions with small stabilizations. The atomic charges and the chemical shifts confirmed the changes of the electronic density, observed through the AIM method.
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Signalspaning i Sverige och USA : En komparativ studie av skyddet för den personliga integriteten vid signalspaning i försvarsunderrättelseverksamhet / Signals intelligence in Sweden and the United States : A comparative analysis of the protection of personal integrity in the collection of electronic communications for foreign intelligence purposes

Wiklund, Marlene January 2020 (has links)
The need to collect electronic communications for foreign intelligence purposes has increased in the past two decades, primarily due to the increase of international threats such as terrorism and proliferation of weapons of mass destruction. Meanwhile, digitalization and technical innovation have given rise to new possibilities for government surveillance and expanded the scope of the types of communications that may be collected. This gives rise to issues concerning the balance between effective foreign intelligence activities and the protection of personal integrity. This thesis performs a comparative analysis of the protection of personal integrity in signals intelligence in Sweden and the United States, by examining the protection of personal integrity under the Swedish Instrument of Government and Article 8 of the European Convention of Human Rights (European Convention) compared to the Fourth Amendment to the United States Constitution, and the requirements for signals intelligence under the Swedish Act (2008:717) on Signals Intelligence in Defense Intelligence Operations (the Surveillance Act) and § 702 of the Foreign Intelligence Surveillance Act (FISA, as amended). The analysis further includes a review of the safeguards adopted in each legal system to limit the collection of communications and to ensure that personal integrity is considered in signals intelligence operations. In regard to the protection of personal integrity, the analysis concludes that Swedish law, combined with the European Convention, offers a wider and more extensive protection for individuals when compared to the United States’ framework. However, all provisions include a requirement of proportionality or reasonableness intended to balance the need for effective law enforcement with the protection of personal integrity. The analysis further concludes that the Fourth Amendment has limited impact on signals intelligence carried out under § 702 FISA due to its limitations to the people of the United States, and that individuals' ability to exercise their rights is greater under the European Convention. The European Convention further offers protection beyond Sweden's borders, resulting in some protection for non-Swedish persons. As for the signals intelligence conducted under the Surveillance Act and § 702 FISA, several similarities and differences are identified. Both regulations limit the signals intelligence to be carried out for certain purposes. However, a notable difference is that, while signals intelligence under both the Surveillance Act and § 702 FISA are limited to foreign conditions, Swedish signals intelligence may be conducted on communications that cross Sweden’s borders. Meanwhile, collection under § 702 FISA may only target non-US persons outside of the United States. Despite this difference, signals intelligence under both regulations result in the collection of communications of the country’s own citizens. To limit the collection, both the Swedish National Defense Radio Establishment (Sw. Försvarets Radioanstalt, FRA) and the United States National Security Agency (NSA) apply certain safeguards. These include the use of search terms in Swedish signals intelligence and selectors in American signals intelligence. While they are both used to make relevant selections in the collection of communications, there are some notable difference between the two. For example, selectors consist of, inter alia, an email address or phone number, while search terms should not, as a general rule, target a specific individual. Further, there is no warrant requirement for collections under § 702 FISA compared to the Surveillance Act, which requires court approval. Lastly, in regard to the control and review of Swedish and American signals intelligence, the analysis concludes that such activities are conducted in different manners in both legal systems. This includes both internal and external controls. However, the Swedish control units appear to have greater opportunities to intervene by, for example, controlling the FRA's access to signal carriers and interrupting an ongoing collection if needed.
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A vigil?ncia na internet: a circula??o midi?tica brasileira do vazamento de dados da NSA por Edward Snowden

Spaniol, Bruna Paiani Nasser 22 September 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-07-11T17:45:40Z No. of bitstreams: 1 BrunaPaianiNasserSpaniol_DISSERT.pdf: 1897318 bytes, checksum: 8fb2478fd40353226077e18215e09ed9 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-07-18T20:03:37Z (GMT) No. of bitstreams: 1 BrunaPaianiNasserSpaniol_DISSERT.pdf: 1897318 bytes, checksum: 8fb2478fd40353226077e18215e09ed9 (MD5) / Made available in DSpace on 2016-07-18T20:03:38Z (GMT). No. of bitstreams: 1 BrunaPaianiNasserSpaniol_DISSERT.pdf: 1897318 bytes, checksum: 8fb2478fd40353226077e18215e09ed9 (MD5) Previous issue date: 2015-09-22 / Esta pesquisa busca compreender como o problema da seguran?a da informa??o no Brasil ? tratado pela tematiza??o p?blica e de que maneira poder? afetar os aspectos pol?ticos e econ?micos do governo e das empresas brasileiras utilizando como estudo de caso o acontecimento do vazamento de documentos daNational Security Agency por Snowden. Para isso, foi realizado o estudo de caso da cobertura da m?dia online sob a perspectiva do paradigma indici?rio, dos estudos sobre circula??o e de acontecimento. Interessa-nos examinar como o tema seguran?a da informa??o ? tratado pela m?dia e qual seu impacto nas rela??es pol?ticas nacionais e internacionais. O caso analisado foi o maior vazamento de dados da hist?ria da NSA, a qual se configura como a ag?ncia de intelig?ncia de mais express?o mundial. Esse vazamento provocou grandes repercuss?es no Brasil, pois foi revelado que o pa?s foi o mais vigiado pelos Estados Unidos, atr?s apenas do pais americano. As consequ?ncias foram um grande tensionamento entre o Brasil e os EUA e a discuss?o p?blica sobre a privacidade e liberdade na internet. A pesquisa analisou 256 publica??es divulgadas por ve?culos de comunica??o brasileiros nos meios digitais, no per?odo entre junho e julho de 2013. / This research seeks to understand how the problem of information security is treated in Brazil by the public thematization and also how it can affect the political and economic aspects of both Brazilian companies and government by using a study case based on the document leak event of the National Security Agency by Snowden. For this, the study case of sites, blogs and news portal coverage was carried out from the perspective of evidential paradigm, studies of movement and event concept. We are interested in examining how the media handles the information security topic and what its impact on national and international political relations. The subject matter was considered the largest data leakage in history of the NSA, which ranks as the world's largest agency of expression intelligence. This leak caused great repercussions in Brazil since it was revealed that the country was the most watched by the United States of America, behind only USA itself. The consequences were: a big tension between Brazil and the US and a public discussion about privacy and freedom on Internet. The research analyzed 256 publications released by Brazilian media outlets in digital media, in the period between June and July 2013.
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Intelligence Oversight Mechanism Used by Congress Study¡ÐCompare with U.S. Congress and Taiwan's Legislative Yuan

Su, Lung-Chi 10 August 2004 (has links)
Abstract This thesis focuses on the oversight mechanism used by congress to supervise the intelligence department, mainly through examining the historical development of the oversight mechanism that the U.S. Congress uses over the Central Intelligence Agency, CIA, as well as evaluating the mechanism¡¦s successes and failures, in order to find a suitable direction for establishing an oversight mechanism for our country¡¦s Legislative Yuan over the National Security Agency, NSA. First of all, the inceptive backgrounds and historical developments of the CIA and the NSA are introduced. After establishing an understanding of the special backgrounds and developments of the two agencies, the writer, using the Institutional Process Theory, analyzes and discusses how the U.S. Congress¡¦ oversight mechanism over the CIA has progressed, thereby determining the key to the successes and failures of the U.S. Congress¡¦ intelligence oversight mechanism. Having analyzed the intelligence oversight mechanism of the U.S. Congress, the writer brings up suggestions as to how our country¡¦s Legislative Yuan can develop an oversight mechanism over the NSA in the future. Lastly, from these discussions, the writer addresses the contributions, propositions, and limitations of this research and hopes that these research and discussions can assist the Legislative Yuan in institutionalizing a comprehensive intelligence oversight mechanism over the NSA.
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Massövervakningens påverkan på intresset för öppen källkod / Mass surveillance impact on interest for open source

Nilsson, Anton January 2014 (has links)
Under 2013 skedde det hittills största läckaget av hemliga dokument. Dessa avslöjanden detaljerar den hemliga övervakning som genomförs av bl.a. amerikanska underrättelsetjänsten NSA (National Security Agency). Offentliggörandet att stora IT-företag är delaktiga i denna övervakningen via samarbete med NSA har även framkommit. Förespråkare av särskilt öppen källkod ser massövervakningen som en inkräktan på den enskildes integritet. Därför är det intressant att ur en studiesynpunkt ta reda på om intresset för öppen källkod har ändrats eller är på väg att ändras på grund av de avslöjanden som skett i samband med avslöjandet av massövervakningen. Öppen källkod kan vara ett alternativ för företag som vill utforska lösningar utöver de traditionella och proprietära leverantörerna. Syftet med studien är att ta reda på om svenska företag anser att massövervakningen påverkar dem samt att undersöka om företag idag använder sig av öppen källkod eller om de nu överväger detta efter vad som offentliggjorts. Finns det en eventuell koppling mellan massövervakningen och intresset för öppen källkod. Frågeställningar är som följer: * Hur stor del av företagen i Sverige använder öppen källkod idag och hur stor del överväger att använda sig mer av öppen källkod? * Finns det en koppling mellan avslöjanden kring massövervakning och intresset för öppen källkod bland svenska företag? En empirisk kvalitativ studie har genomförts för att besvara dessa frågeställningar utifrån företags- och organisationers svar och åsikter från genomförda intervjuer med slumpmässigt utvalda respondenter. En intervjuguide med utvärderande frågor skrevs med ansatsen att ge respondenterna en öppenhet i deras svar. Resultatet påvisar att svenska företag generellt inte tillämpat större förändringar inom sina system efter offentliggörandet av massövervakningen utan fokus har istället legat på att förändra sina IT-säkerhetspolicys samt ett förändrat synsätt på hantering av hur dokument sparas och skickas. Svenska företag använder generellt öppen källkod i större skala då det numera ses som ett mer accepterat alternativ samt en bra grund att bygga applikationer på. Företag som sedan tidigare innehar en utpräglad Microsoft-strategi är inte särskilt villiga att titta på alternativa lösningar utan förklarar att de har tillit till sina leverantörer samt att implementering resulterar i kostnadsfrågor. Sensmoralen är att det kan finnas ett samband mellan massövervakningen och intresset för öppen källkod inom IT-branschen men att detta ännu är något tidigt att uttala sig om då större märkbara förändringar tar tid att genomföra. / The year 2013 presented the largest disclosure of clandestine documents to date. These documents entailed information regarding global surveillance programs and their operation by intelligence-agencies such as the U.S NSA (National Security Agency) and locally in Sweden by NSAs counterpart the FRA (National Defense Radio Establishment). Furthermore, intelligence-disclosures revealed that large IT-companies participated in these surveillance-actions and actively shared user-data with the NSA. As a result of the disclosures there was an especially noticeable outcry from supporters of open source software who spoke out against these surveillance-programs as a gross violation of civil liberties. As a result of this a study felt appropriate to reveal if an interest towards open source has changed or become more representable within Swedish businesses. The aim of this study is to evaluate if companies within the IT-sector consider global surveillance as affecting their business, as well to ascertain if open source is being used within the business-model, or if it has become a more representable option since global surveillance was disclosed. An empirical study was conducted to answer these questions from a business and organizational standpoint by the use of interviews by randomly selected respondents. An evaluating questioners-guide was designed to promote candidness in the respondents’ answers and opinions as well as to encourage discussions. The result indicates that Swedish companies and businesses in general haven’t implemented any major changes to their system architecture. They have instead opted to focus on revising their IT-security policies as well as adopting a new approach towards how management of sensitive files are to be stored and shared in a safe manner. The adoption of open source within businesses has grown in scale, and it is now considered a more acceptable alternative as well as a god basis to build applications and softwareupon. Companies with a very distinctive Microsoft-strategy however have shown some resistance in the adoption of open source, mainly because of high deployment costs, while maintain and asserting confidence towards their IT-suppliers. The essence of it all dictates that there may be a connection between global surveillance and an interest towards open source within the IT-sector, but that this is still somewhat premature to comment on as major changes in infrastructure take time to implement and that companies don’t yet know how global surveillance will affect them in the future.

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