Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-02-06T18:21:03Z No. of bitstreams: 2 Dissertação - Bruno Pontes Caixeta - 2014.pdf: 1763848 bytes, checksum: 7462015149307babdc173bd055c436f9 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-02-06T18:21:16Z (GMT) No. of bitstreams: 2 Dissertação - Bruno Pontes Caixeta - 2014.pdf: 1763848 bytes, checksum: 7462015149307babdc173bd055c436f9 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-02-06T18:21:16Z (GMT). No. of bitstreams: 2 Dissertação - Bruno Pontes Caixeta - 2014.pdf: 1763848 bytes, checksum: 7462015149307babdc173bd055c436f9 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-02-07 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / In this study, the synthesis of five carbonylcyanidephenylhydrazone (ccp), with general formula [RC6H4NHNC(CN)2], where R (= -CH3, -H, -COOH, -CN e -NO2), and their coordination complexes with Ag(I) is presented. Subsequently, these compounds were characterized using spectroscopic methods. The analysis of the compound ccp-H by X Ray diffraction reveals that structurally this compound consists of a nearly linear and planar polymeric form. Data from infrared spectroscopy suggest the formation of hydrogen bonds between the units ccp. In the synthesized Ag(I) coordination compounds, the coordination of each Ag(I) occurs with three ccp units, forming a tridentate ligand-metal coordination with the formation of a three-dimensional structure. In the evaluation of the potential of these compounds to present expressive nonlinear optical properties (NLO), with special attention to the first hyperpolarizability (β), methods from Density Functional Theory (DFT) were employed to describe the structural and electronic characteristics of these compounds, and in the calculation of this parameter. The results show that the incorporation of a group with a strong electron acceptor character, along with the introduction of Ag(I), increases significantly the  values. On the other hand, the results suggest that the CAM-B3LYP functional provides more reliable  values, since the calculations based on this functional reproduced well experimental values of  related to compounds used to calibrate the instrumentation used in these measurements. Based on the estimated  values, it is expected that the studied coordination polymers present promising characteristics for use in photonic devices. / Neste estudo, a síntese de cinco carbonilcianetofenilhidrazonas (ccp), com fórmula geral [RC6H4NHNC(CN)2], onde R = -CH3, -H, -COOH, -CN e -NO2, e de seus compostos de coordenação com Ag(I), é apresentada. Esses compostos foram subsequentemente analisados do ponto de vista espectroscópico. A análise por difração de Raios X em monocristal do composto ccp-H revela que o mesmo é uma forma polimérica estruturalmente planar e praticamente linear. Resultados obtidos por espectroscopia no infravermelho sugerem a formação de ligações de hidrogênio entre as unidades ccp. Nos compostos de coordenação sintetizados, a coordenação de cada íon Ag(I) envolve três unidades ccp, resultando em uma coordenação tridentada entre os ligantes e o metal, resultando em uma estrutura tridimensional. Na avaliação do potencial desses compostos de apresentarem propriedades ópticas não lineares (ONL) expressivas, com atenção especial para a primeira hiperpolarizabilidade (β), foram empregados métodos da Teoria do Funcional da Densidade (DFT) na descrição estrutural e eletrônica, e no cálculo de parâmetros ópticos não-lineares. Os resultados mostram que a incorporação de um grupo com um forte caráter aceitador de elétrons e a introdução de Ag(I) aumenta significativamente os valores de . Por outro lado, os resultados sugerem que o funcional CAM-B3LYP deve fornecer os valores mais confiáveis de , já que nos cálculos com este funcional conseguiu-se reproduzir valores experimentais do  de padrões usados para aferir a instrumentação usada nessas medidas. Com base no observado, espera-se que os polímeros de coordenação apresentem características promissoras para aplicação em dispositivos fotônicos.

Submitted by PPG Ci?ncias Sociais (csociais-pg@pucrs.br) on 2018-08-06T14:38:12Z No. of bitstreams: 1 Alexandre.pdf: 2065974 bytes, checksum: 8926dae8aa2e14f74a71ece061946c2c (MD5) / Approved for entry into archive by Sheila Dias (sheila.dias@pucrs.br) on 2018-08-08T11:31:03Z (GMT) No. of bitstreams: 1 Alexandre.pdf: 2065974 bytes, checksum: 8926dae8aa2e14f74a71ece061946c2c (MD5) / Made available in DSpace on 2018-08-08T11:47:42Z (GMT). No. of bitstreams: 1 Alexandre.pdf: 2065974 bytes, checksum: 8926dae8aa2e14f74a71ece061946c2c (MD5) Previous issue date: 2018-05-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Based on an ethnography, carried out over three years, this work seeks to problematize the contours of the contemporary production of desire through the processes of subjectivation that emerge in the encounter of a young person with a set of public policies of social reinsertion, education, and health. These policies were triggered in order to affirm citizenship, constituting new life possibilities after the violent incident that would deeply mark this young man?s trajectory. The possibility of accompanying this resistance in his meetings with the margins of the state, characterized by an intense institutional movement, allowed mapping their assemblages in the composition of existential territories related to the different ways in which the public policies are put before ways of life. Thus, this ?Toxic State? produces poisoned relationships, that when the guarantees of citizenship are broken, subjects are positioned as victims of the government, creating the social and subjective conditions for the formation of the territory of the crime. / Como resultado de uma etnografia realizada ao longo de tr?s anos a presente disserta??o procura problematizar os contornos da produ??o desejante no contempor?neo por meio dos processos de subjetiva??o que emergem no encontro de um jovem com um conjunto de pol?ticas p?blicas de reinser??o social, educa??o e sa?de. As referidas pol?ticas foram acionadas de modo a afirmar sua cidadania constituindo novas possibilidades de vida depois do incidente violento que marcaria profundamente esta trajet?ria. A possibilidade de acompanhar a resist?ncia deste jovem em seus encontros com as margens do Estado, caracterizada por uma intensa circula??o institucional, permitiu cartografar seus agenciamentos na composi??o de territ?rios existenciais relacionados ?s diferentes maneiras com que as pol?ticas p?blicas se colocaram frente ao seu modo de vida. Desta rela??o destaca-se a presen?a de um Estado T?xico produtor de rela??es envenenadas que, ao romper com as garantias cidad?s, posiciona os sujeitos como v?timas do governo, criando as condi??es sociais e subjetivas para a forma??o do territ?rio do crime.

Tese de mestrado integrado. Engenharia Química. Faculdade de Engenharia. Universidade do Porto. 2010

The Coeur d'Alene district in northern Idaho is a world class Pb-Ag mesothermal vein system that has produced about 360 million ounces of silver, lead, and zinc since the 1880s. Despite the long history of exploration and production, the district does not have a predictive model for exploration based on a sound understanding of structural controls on the silver ore deposits; this is certainly the case for the Sunshine Mine and surrounding area. Fault kinematic history in the district shows a regional scale fault system reactivated over time with dextral, sinistral, and dip-slip displacement. The fault system is superimposed on regional deformation fabrics that were examined for this study in the Sunshine Mine area. Cleavage sets observed in the Sunshine mine area, distinguished by orientation and superposition relationships, are consistent with the findings of Smith (2004) which defined cleavage sets referred to as S1, S2, and S3. Two additional deformation fabrics that appear spatially tied to fault zones formed between development of cleavages S2 and S3. The multiple cleavages, fault zones, and their intersections are interpreted to act as pathways for hydrothermal fluids associated with vein formation and silver ore deposition. Thin section kinematic analysis of vein and shear zone samples defined a dip-slip sense of shear associated with the Sterling vein. Electron Backscatter Diffraction (EBSD) analysis of vein and shear zone samples failed to define a lattice preferred crystallographic orientation that defined shear sense. Similarly, cathodoluminescence (CL) analysis of thin section textures failed to define a dominant shear sense and fault kinematics. Nevertheless, additional study using these techniques is warranted. Both field observation and thin section analysis demonstrate a direct relationship between shear zones, veins, and mineralization potential, clarifying the need for detailed fault maps for the Sunshine Mine area and Coeur d'Alene district.

The photocatalytic oxidation of trichloroethylene (TCE), ethylene. ethane and toluene on TiO2, Pt/TiO2 and Ag/TiO2 were investigated in a dedicated reactor set-up operated at room temperature and ambient pressure condition. The gas phase experiments were carried out for both single and binary mixtures of these chemicals to identify the role of Pt and Ag metallisation in the photocatalytic oxidation of different contaminants. In a single contaminant system, the presence of Pt enhanced the oxidation of ethylene, ethane and toluene but detrimental to the oxidation of TCE. In the oxidation of ethylene, Pt enhanced the oxidation by acting as catalyst and as electron sink. However, in ethane oxidation, the enhancement was solely associated to the ability of Pt to act as electron sink. The detrimental effect observed in TCE oxidation was attributed to Pt and Cl interaction, which formed a persistent inorganic chlorine species decreasing the overall Pt/TiO2 photocatalyst performance. Interestingly, Ag did not show any significant effect to the oxidation of any single system degradation. In binary system degradation, where TCE and another organic compound either ethylene, ethane or toluene were degraded simultaneously, Pt always caused a detrimental effect due to its strong interaction with Cl. However, the presence of Ag and Cl gives a more synergetic effect. Ag was found to provide sites to temporarily trap chlorine radicals as AgCl. Under illumination, electrons transferred from Cl to Ag forming chlorine radicals that could react with the surface contaminant enhancing its breakdown and mineralization.

An electron momentum spectrometer at the Australian National University has been used to study various aspects of different solid state systems. EMS is a transmission mode technique and involves the collision of the incident electron with a bound electron, after which both electrons are ejected and measured in coincidence. Through well defined reaction kinematics the complete valence spectral momentum density A(ɛ,q) can be measured. The spectrometer has been used to measure the spectral momentum densities (spectral functions) of single crystal targets, as well as targets in disordered states. A new spin polarised electron source was constructed and implemented in the ANU spectrometer, which was used to measure spin dependent features of ferromagnetic samples.¶ This thesis is divided into seven chapters, the first chapter is an introduction into the field of electron momentum spectroscopy, highlighting what has been measured before and how the technique has progressed to its present state. Some comparisons to other experimental techniques will be made.¶ The second chapter describes the ANU EMS spectrometer in detail. The technique requires some technical and advanced equipment that is often used in novel ways. The production of thin (20 nm) free standing targets will be detailed, along with the experimental chamber and electronics used to run the apparatus and collect data. The determination of the energy and momentum resolution of the experiment is also described.¶ The third chapter will detail the design and construction of the new spin polarised electron source. The results of commissioning and characterizing the new source will be presented.¶ Chapters four through six will present the measured results. The fourth chapter will detail the single crystalline measurements for the group eleven noble metals (Cu, Ag and Au). Each sample was measured along three high symmetry directions and compared to a DFT calculation using the LDA and a FP-LMTO basis. The fifth chapter will include the results from samples that were in disordered states, a measurement which is unique to the EMS technique. The polycrystalline and amorphous states of the Si and Ge semiconductors are presented and conclusions are made to the degree of difference in the results and to which theoretical approach to the unique amorphous state of the semiconductors best matches the EMS results. The sixth chapter includes results of ferromagnetic iron, measured using the spin polarised electron source. The spectrometer was used to measure spin-polarised electron-energy-loss-spectroscopy (SPEELS) and magnetic electron-Compton profiles. A theoretical investigation is also presented in chapter six which details the advancements required in the spin polarised electron gun to measure an accurate spin-polarised EMS spectra of a ferromagnetic Fe sample.¶ Chapter 7 includes the summary of all the results presented and conclusions reached from the comparison of the measured EMS spectra and various theoretical calculations. A discussion is presented about the future directions and possibilities of the EMS technique.

Zugl.: Köln, Universiẗat, Diss., 2007.

La synthèse dans un verre d'agrégats métalliques ou semiconducteurs permet l'étude de leurs<br />propriétés intrinsèques et la réalisation de dispositifs pour l'optoélectronique. L'implantation ionique per-<br />met en principe de s'affranchir des limites de solubilité, mais permet-elle un contrôle de la densité, la taille<br />moyenne et de la distribution de tailles des agrégats réalisés ? Nous avons étudié les effets de l'implantation :<br />écart à l'équilibre thermodynamique, et dépôt d'énergie générateur de porteurs (électrons et trous) chargés.<br />Nous montrons l'importance de l'oxydoréduction due au passage et à l'arrêt des ions, et faisons varier la<br />densité d'énergie déposée pour induire des conditions réductrices favorables à la précipitation d'agrégats<br />métalliques. Le mécanisme d'agrégation de Ag dans le verre est analogue à celui de la photographie. Nous<br />avons ensuite étudié la croissance d'agrégats de semiconducteurs composés - les chalcogénures de plomb<br />(PbS, PbSe, PbTe), aux propriétés optiques intéressantes. Nous mettons en évidence les effets complexes de<br />la chimie redox des chalcogènes, et leur lien avec la perte de contrôle de la croissance d'agrégats synthétisés<br />après implantation séquentielle de Pb et S. Nous développons une nouvelle synthèse contrôlée d'agrégats de<br />PbS consistant, avant recuit, à implanter du soufre dans des verres au Pb. Le choix de la composition du<br />verre permet de contrôler la croissance, et l'implantation de S permet d'atteindre des fractions volumiques<br />importantes. Les propriétés d'émission optique de ces agrégats dans l'infrarouge (vers 1,5 µm) font appa-<br />raître une section efficace d'excitation très importante et l'existence d'un niveau d'"exciton noir".

Ce manuscrit se concentre sur l'analyse du GISAXS d'îlots sur un substrat. Les données GISAXS doivent être analysées de façon quantitative afin d'obtenir des paramètres morphologiques précis (courbes de croissance, forme d'équilibre de l'îlot et énergie interfaciale) pour le processus d'élaboration. L'accent est mis sur le facteur de forme de l'îlot, c'est-à-dire la transformée de Fourier de la forme de l'îlot. On montre que la forme de l'îlot et la taille peuvent être obtenues à partir de la symétrie de l'îlot, la présence de facettes de l''îlot, le comportement asymptotique loin dans l'espace réciproque pour une grande polydispersité et les zéros ou les minima de l'intensité pour une faible polydispersité. Une comparaison approfondie entre l'approximation de Born et l'approximation plus précise de l'onde distordue (DWBA) met en évidence la spécificité apportée par la géométrie en incidence rasante. L'analyse quantitative est illustrée pour des images GISAXS acquises in situ pendant l'épitaxie par jet moléculaire de nano-îlots Ag ou Pd sur MgO(001) pour différentes épaisseurs et températures. Les paramètres morphologiques obtenus sont en très bon accord avec des résultats de microscopie électronique à transmission. Finalement, la diffusion incohérente a été mise en évidence en GISAXS et a pour origine des corrélations entre les îlots.

<p>In this Thesis the magnetic and structural properties of thin epitaxial Fe, Co, and Ni films are discussed. Some of the in-situ prepared samples were used to characterize the degree of circular polarization of the newly installed beamline D1011 at MAX-lab. By means of x-ray magnetic circular dichroism (XMCD) and utilizing the associated magneto optic sum rules, the orbital (<i>m</i><i>l</i>) and spin (<i>m</i><i>s</i>) moments are determined directly in <i>m</i><i>B</i>/atom with elemental specificity. The extended x-ray absorption fine structure (EXAFS) measurements yield site specific information on the local crystallographic structure.</p><p>These measurements were performed using the circular x-rays of several beamlines. The influence of the degree of spatial source coherence <i>l</i><i>spat</i> of the x-rays was characterized by means of Fresnel diffractometry. A correlation between enhanced XAS white line intensities and higher values of <i>l</i><i>spat</i> was established for 20 ML Fe, Co, and Ni films on Cu(100).</p><p>The degree of circularly polarized x-rays (<i>P</i><i>c</i>) at beamline D1011 at MAX-lab was characterized by studying Fe films on Cu(100) by means of XMCD. The maximum value of <i>P</i><i>c</i> is experimentally determined to <i>P</i><i>c</i> =0.85.</p><p>The Au/Co/Au trilayer system was studied as a function of Co thickness, temperature, and Au cap thickness. A 10 mono-layer (ML) Co film, with an Au cap of 20 Å, shows a spin reorientation transition (SRT) from an in-plane to an out-of-plane easy direction as the temperature is lowered from 300 K to 200 K. The magnetic properities of these Co films are very different to what is found for bulk samples due to, in particular, the broken symmetry at the interfaces.</p><p>The thickness dependent spin reorientation transition in the Fe/Ag(100) system was characterized by means of XMCD and EXAFS measurements. 3 ML Fe films show an out-of-plane easy direction with an 125% enhanced orbital moment as compared to the 25 ML Fe in-plane film. Simulations of the Fe <i>L</i>-edge EXAFS indicate the bulk Fe bcc structure for film thicknesses of 6-25 ML Fe. For 3 ML Fe strong deviations from this bcc phase is observed.</p><p>Ultrathin Co films deposited on flat and vicinal Cu(111) in the thickness region 1-25 ML were studied by means of XMCD and scanning tunneling microscopy (STM). The vicinal Cu(111) Co deposition leads to the formation of elongated islands preferentially oriented along the step edges. In connection to this particular Co growth mode we observe an increase of both the orbital and the spin moment on the vicinal Cu(111) of about 25% relative to what was observed for Co on flat Cu(111).</p>