A travessia do trágico no romance d A Pedra do Reino de Ariano Suassuna

The present work seeks to investigate and discuss about the Greek Tragedy s elements at Ariano Suassuna s romance called τ Romance d A Pedra do Reino e o Principe do Sangue do Vai e Volta, connecting it directly to mythic, epic, poetic, and romances aspects at his work. The romance has as the protagonist the backcountry Pedro Dinis Quaderna. Quaderna is a character which is simultaneously popular, elitist, enigmatic, naive, and an intellectual man that has a great erudition. Quaderna is a character that seeks, by using the Literature, to reestablish a Brazilian backcountry kingdom which he s supposedly the king, always trying to empathizes the Brazilian northeast region like if it was a nation apart. By impressing a national personality to the Brazilian northeast , Quaderna tries to become an epic poet just like Homer, denoting a strong influence of the Epopee. Quaderna, just like many characters of Greek Tragedy, has at his family past time a lot of tragic circumstances. These facts that ocurred to his relativos like the your uncle Pedro Sebastião Garcia Barreto s death, the disappearement of his cousin Sinésio, and the contest between the brothers Arésio and Sinésio, and others aspects, remind us remarkable influences, beyond the Epopee, of the Greek Tragedy. By reading the romance we may notice many similarities between Quaderna s trajectory and Greek Tragedy heroes. To make an analysis about the tragic aspects at Suassuna s work, we need to dialogue with many theoreticals that have written about the tragic and comparate with many parts of Suassuna s with classics character s texts of Greek Tragedy. At the following chapters we seek to provide romance s elementaries notions, as well as tragic notions, the dialogue with mythics aspects and the tragic and epic aplicability at Suassuna s work

Investigação da estabilidade térmica e das propriedades elétricas do TiO2 em função da dopagem com Ce(SO4)2

The metalic oxides have been studies due to differents applications as materials semiconductor in solar cells, catalysts, full cells and, resistors. Titanium dioxide (TiO2) has a high electric conductivity due to oxygen vacancies. The Ce(SO4)2.2H2O doped samples TiO2 and TiO2 pure was obtained sol-gel process, and characterized by X-ray diffractometry,thermal analysis, and impedance spectroscopy. The X-ray diffraction patterns for TiO2 pure samples shows at 700°C anatase phase is absent, and only the diffraction peaks of rutile phase are observed. However, the cerium doped samples only at 900°C rutile in the phase present with peaks of cerium dioxide (CeO2). The thermal analysis of the TiO2 pure and small concentration cerium doped samples show two steps weight loss corresponding to water of hydration and chemisorbed. To larger concentration cerium doped samples were observed two steps weight loss in the transformation of the doped cerium possible intermediate species and SO3. Finally, two steps weight loss the end products CeO2 and SO3 are formed. Analyse electric properties at different temperatures and concentration cerium doped samples have been investigated by impedance spectroscopy. It was observed that titanium, can be substituted by cerium, changing its electric properties, and increased thermal stability of TiO2 anatase structure

Obtenção e Caracterização Físico-Química do Sistema Compósito PEG-TiO2

Hybrid systems formed from polymers and transition metals have now their physical and chemical properties extensively investigated for use in electronic devices. In this work, Titanium Dioxide (TiO2) from the precursor of titanium tetrabutoxide and the composite system Poly(Ethylene Glycol)-Titanium Dioxide (TiO2-PEG) were synthesized by sol-gel method. The PEG as acquired and TiO2 and composites powders were analyzed by X-Ray Diffraction (XRD), Spectroscopy in the Infrared region with Fourier transform (IRFT), Thermogravimetric Analysis (TGA), Scanning Electron Microscopy (SEM) and Electrochemical Impedance Spectroscopy (EIS). In the XRD analysis were observed in the TiO2 crystal faces of one of its polymorphs - anatase phase, crystal planes in Poly (Ethylene Glycol) with considerable intensity and in the composite systems the mixture of crystal faces of their precursors isolated and reduction of crystallinity. The TG / DTG suggested increasing the thermal instability of PEG in the composite powders as TiO2 is incorporated into the system. Spectral analysis presented in the infrared overlapping bands for the polymer and metal oxide, reducing the intensity of symmetric stretching of ligand groups in the main chain polymer and angular deformations; were observed using SEM micrographs of the morphological changes suffered by composite systems with the variation of the oxide concentration. Analyses by impedance spectroscopy indicated that the increased conductivity in composite occurs in line with the addition of the metal oxide concentration in the composite system

Estudo de titanatos nanoestruturados obtidos por tratamento hidrotérmico de óxido de titânio em meio alcalino

TiTanate NanoTubes (TTNT) were synthesized by hydrothermal alkali treatment of TiO2 anatase followed by repeated washings with distinct degrees of proton exchange. TTNT samples with different sodium contents were characterized, as synthesized and after heattreatment (200-800ºC), by X-ray diffraction, scanning and transmission electron microscopy, electron diffraction, thermal analysis, nitrogen adsorption and spectroscopic techniques like FTIR and UV-Vis diffuse reflectance. It was demonstrated that TTNTs consist of trititanate structure with general formula NaxH2−xTi3O7·nH2O, retaining interlayer water in its multiwalled structure. The removal of sodium reduces the amount of water and contracts the interlayer space leading, combined with other factors, to increased specific surface area and mesopore volume. TTNTs are mesoporous materials with two main contributions: pores smaller than 10 nm due to the inner volume of nanotubes and larger pores within 5-60 nm attributed to the interparticles space. Chemical composition and crystal structure of TTNTs do not depend on the average crystal size of the precursor TiO2-anatase, but this parameter affects significantly the morphology and textural properties of the nanostructured product. Such dependence has been rationalized using a dissolution-recrystallization mechanism, which takes into account the dissolution rate of the starting anatase and its influence on the relative rates of growth and curving of intermediate nanosheets. The thermal stability of TTNT is defined by the sodium content and in a lower extent by the crystallinity of the starting anatase. It has been demonstrated that after losing interlayer water within the range 100-200ºC, TTNT transforms, at least partially, into an intermediate hexatitanate NaxH2−xTi6O13 still retaining the nanotubular morphology. Further thermal transformation of the nanostructured tri- and hexatitanates occurs at higher or lower temperature and follows different routes depending on the sodium content in the structure. At high sodium load (water washed samples) they sinter and grow towards bigger crystals of Na2Ti3O7 and Na2Ti6O13 in the form of rods and ribbons. In contrast, protonated TTNTs evolve to nanotubes of TiO2(B), which easily convert to anatase nanorods above 400ºC. Besides hydroxyls and Lewis acidity typical of titanium oxides, TTNTs show a small contribution of protonic acidity capable of coordinating with pyridine at 150ºC, which is lost after calcination and conversion into anatase. The isoeletric point of TTNTs was measured within the range 2.5-4.0, indicating behavior of a weak acid. Despite displaying semiconductor characteristics exhibiting typical absorption in the UV-Vis spectrum with estimated bandgap energy slightly higher than that of its TiO2 precursor, TTNTs showed very low performance in the photocatalytic degradation of cationic and anionic dyes. It was concluded that the basic reason resides in its layered titanate structure, which in comparison with the TiO2 form would be more prone to the so undesired electron-hole pair recombination, thus inhibiting the photooxidation reactions. After calcination of the protonated TTNT into anatase nanorods, the photocatalytic activity improved but not to the same level as that exhibited by its precursor anatase

Obtenção e caracterização do sistema compósito alginato de sódio-dióxido de titânio em formas de pó e de membrana

The alginates are copolymers of 1→4-linked β-D-mannuronic acid (M) and α-Lguluronic acid (G) residues that are arranjed in a block structure along a linear chain. Titanium dioxide, TiO2, is a ceramic material and can exist in three distinct crystallography forms: anatase, brookite and rutile. composites of organic and inorganic materials have better properties than the components alone. Thus, this study aims to synthesize, characterize and analyze the composite NaAlg-TiO2 in the form of powder and film. The synthesis of composite powders was performed using the sol-gel process and obtain the composite film was performed using the slow evaporation process, then the composites were analyzed by infrared spectroscopy, fluorescence x ray, thermal analysis, attenuated total reflection (ATR), x ray diffraction and impedance spectroscopy. The X ray diffraction patterns of composite powders show that with increasing calcination temperature, there were no complete transition of rutile-anatase crystalline phase, since at all temperatures studied (300, 500, 700, 900 and 1100ºC) were observed peaks of anatase phase. Thermal analysis shows that at 400°C caused the decomposition of sodium alginate in sodium carbonate and above 600°C, we observe an exothermic peak related to the decomposition of sodium carbonate and in the presence of titanium dioxide becomes sodium titanate. The XRD results confirm the formation of sodium carbonate at 700ºC and the formation sodium titanate in the temperature range 900-1100ºC. The sodium titanate influenced the electrical properties of the material, because with increasing temperature there was a decrease in conductivity, probably due to the creation of Ti vacancies, since the sodium can induce the reduction of surface Ti4+ ions into Ti3+ species. The infrared spectra of the composites in the form of powder and film showed a small shift in the bands compared to the spectrum of pure alginate, indicating that these shifts, even small ones, have evidence of miscibility between the polymer and ceramic material

Síntese hidrotérmica e caracterização estrutural de titanatos nanotubulares para aplicação na captura do dióxido de carbono

Nanostructured materials have been spreading successfully over past years due its size and unusual properties, resulting in an exponential growth of research activities devoted to nanoscience and nanotechnology, which has stimulated the search for different methods to control main properties of nanomaterials and make them suitable for applications with high added value. In the late 90 s an alternative and low cost method was proposed from alkaline hydrothermal synthesis of nanotubes. Based on this context, the objective of this work was to prepare different materials based on TiO2 anatase using hydrothermal synthesis method proposed by Kasuga and submit them to an acid wash treatment, in order to check the structural behavior of final samples. They were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), adsorption/desorption of N2, thermal analysis (TG/DTA) and various spectroscopic methods such as absorption spectroscopy in the infrared (FT-IR), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). All the information of characterizations confirmed the complete conversion of anatase TiO2 in nanotubes titanates (TTNT). Observing the influence of acid washing treatment in titanates structure, it was concluded that the nanotubes are formed during heat treatment, the sample which was not subjected to this process also achieved a complete phase transformation, as showed in crystallography and morphology results, however the surface area of them practically doubled after the acid washing. By spectroscopy was performed a discussion about chemical composition of these titanates, obtaining relevant results. Finally, it was observed that the products obtained in this work are potential materials for various applications in adsorption, catalysis and photocatalysis, showing great promise in CO2 capture

Guimarães Rosa: travessia

This study develops a reading of five tales of Guimarães Rosa: “A hora e vez de Augusto Matraga”, “Campo Geral”, “A Benfazeja”, “Esses Lopes” and “Meu tio o Iauaretê”, included, respectively, in Sagarana, Corpo de Baile, Primeiras Estórias, Tutaméia and Estas Estórias. Then, undertakes a brief course in order to observe in the creative genesis of the author a manichean theme, whose view of the world, with poetic intensity, opposes the good and the evil. This research thus has drawn upon the Mythical Symbolism, in Literary Criticism and aspects of Metaphisics, in addition to analyzing classic literary essays in approaching of histories masterpiece structure. It has also demonstrate that in the rosiano hinterland the contradictory contributes to the speculation about the human man, in the continuous learning of his passing

A travessia do trágico no romance d A Pedra do Reino de Ariano Suassuna

The present work seeks to investigate and discuss about the Greek Tragedy s elements at Ariano Suassuna s romance called τ Romance d A Pedra do Reino e o Principe do Sangue do Vai e Volta, connecting it directly to mythic, epic, poetic, and romances aspects at his work. The romance has as the protagonist the backcountry Pedro Dinis Quaderna. Quaderna is a character which is simultaneously popular, elitist, enigmatic, naive, and an intellectual man that has a great erudition. Quaderna is a character that seeks, by using the Literature, to reestablish a Brazilian backcountry kingdom which he s supposedly the king, always trying to empathizes the Brazilian northeast region like if it was a nation apart. By impressing a national personality to the Brazilian northeast , Quaderna tries to become an epic poet just like Homer, denoting a strong influence of the Epopee. Quaderna, just like many characters of Greek Tragedy, has at his family past time a lot of tragic circumstances. These facts that ocurred to his relativos like the your uncle Pedro Sebastião Garcia Barreto s death, the disappearement of his cousin Sinésio, and the contest between the brothers Arésio and Sinésio, and others aspects, remind us remarkable influences, beyond the Epopee, of the Greek Tragedy. By reading the romance we may notice many similarities between Quaderna s trajectory and Greek Tragedy heroes. To make an analysis about the tragic aspects at Suassuna s work, we need to dialogue with many theoreticals that have written about the tragic and comparate with many parts of Suassuna s with classics character s texts of Greek Tragedy. At the following chapters we seek to provide romance s elementaries notions, as well as tragic notions, the dialogue with mythics aspects and the tragic and epic aplicability at Suassuna s work