Incorporação da apatita na superfície da liga Ti30ta empregando tratamento alcalino associado à eletrofiação de fibras de PCL

Pós-graduação em Engenharia Mecânica - FEG

Syngonanthus nitens (Bong.) Ruhland: caracterização biológica e prospecção terapêutica do extrato metanólico incorporado ou não em sistema nanoestruturado para aplicação no tratamento da candidíase vulvovaginal

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sistemas precursores de cristais líquidos mucoadesivos para administração bucal de curcumina no tratamento do câncer bucal

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Desenvolvimento de sensores de gás a partir de óxido semicondutor nanoestruturado

The present work aims to study one-dimensional nanomaterials semiconductors grown via by phase systems Grande oxides Technological Interest for applications in gas sensors. The Used material was tin oxide (SnO2) for their functional properties, and the grow method was the Polymeric Precursors. The films grown were the nanomaterials about substrates of alumina, deposited via spin coating technique, followed by heat treatment at 300C for 1 hour and 650C for 2 hours. Later the films of Performance sensors (sensitivity, speed response, selectivity, and stability) will be in avaliated in a hermetic chamber with controlled atmosphere and temperature. The synthesized materials were its structural and morphological properties characterized in atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (not have this result with Me). We sought to investigate one influence of different conditions for obtaining films (Variation Layers number) in structural and microstructural properties of semiconductors oxides. The synthesis method proved very effective, generating films with micro definitely, uniformity of the nanoparticles and hum high level of porosity, what makes the material of a viable final paragraph applicability

Desenvolvimento de sensores de gás a partir de óxido semicondutor nanoestruturado

The present work aims to study one-dimensional nanomaterials semiconductors grown via by phase systems Grande oxides Technological Interest for applications in gas sensors. The Used material was tin oxide (SnO2) for their functional properties, and the grow method was the Polymeric Precursors. The films grown were the nanomaterials about substrates of alumina, deposited via spin coating technique, followed by heat treatment at 300C for 1 hour and 650C for 2 hours. Later the films of Performance sensors (sensitivity, speed response, selectivity, and stability) will be in avaliated in a hermetic chamber with controlled atmosphere and temperature. The synthesized materials were its structural and morphological properties characterized in atomic force microscopy (AFM), scanning electron microscopy (SEM), X-ray diffraction (XRD) and transmission electron microscopy (not have this result with Me). We sought to investigate one influence of different conditions for obtaining films (Variation Layers number) in structural and microstructural properties of semiconductors oxides. The synthesis method proved very effective, generating films with micro definitely, uniformity of the nanoparticles and hum high level of porosity, what makes the material of a viable final paragraph applicability

Functional alkali tantalate 2D structures for microelectronics and related applications

Alkali tantalates and niobates, including K(Ta / Nb)O3, Li(Ta / Nb)O3 and Na(Ta / Nb)O3, are a very promising ferroic family of lead-free compounds with perovskite-like structures. Their versatile properties make them potentially interesting for current and future application in microelectronics, photocatalysis, energy and biomedics. Among them potassium tantalate, KTaO3 (KTO), has been raising interest as an alternative for the well-known strontium titanate, SrTiO3 (STO). KTO is a perovskite oxide with a quantum paraelectric behaviour when electrically stimulated and a highly polarizable lattice, giving opportunity to tailor its properties via external or internal stimuli. However problems related with the fabrication of either bulk or 2D nanostructures makes KTO not yet a viable alternative to STO. Within this context and to contribute scientifically to the leverage tantalate based compounds applications, the main goals of this thesis are: i) to produce and characterise thin films of alkali tantalates by chemical solution deposition on rigid Si based substrates, at reduced temperatures to be compatible with Si technology, ii) to fulfil scientific knowledge gaps in these relevant functional materials related to their energetics and ii) to exploit alternative applications for alkali tantalates, as photocatalysis. In what concerns the synthesis attention was given to the understanding of the phase formation in potassium tantalate synthesized via distinct routes, to control the crystallization of desired perovskite structure and to avoid low temperature pyrochlore or K-deficient phases. The phase formation process in alkali tantalates is far from being deeply analysed, as in the case of Pb-containing perovskites, therefore the work was initially focused on the process-phase relationship to identify the driving forces responsible to regulate the synthesis. Comparison of phase formation paths in conventional solid-state reaction and sol-gel method was conducted. The structural analyses revealed that intermediate pyrochlore K2Ta2O6 structure is not formed at any stage of the reaction using conventional solid-state reaction. On the other hand in the solution based processes, as alkoxide-based route, the crystallization of the perovskite occurs through the intermediate pyrochlore phase; at low temperatures pyrochlore is dominant and it is transformed to perovskite at >800 °C. The kinetic analysis carried out by using Johnson-MehlAvrami-Kolmogorow model and quantitative X-ray diffraction (XRD) demonstrated that in sol-gel derived powders the crystallization occurs in two stages: i) at early stage of the reaction dominated by primary nucleation, the mechanism is phase-boundary controlled, and ii) at the second stage the low value of Avrami exponent, n ~ 0.3, does not follow any reported category, thus not permitting an easy identification of the mechanism. Then, in collaboration with Prof. Alexandra Navrotsky group from the University of California at Davis (USA), thermodynamic studies were conducted, using high temperature oxide melt solution calorimetry. The enthalpies of formation of three structures: pyrochlore, perovskite and tetragonal tungsten bronze K6Ta10.8O30 (TTB) were calculated. The enthalpies of formation from corresponding oxides, ∆Hfox, for KTaO3, KTa2.2O6 and K6Ta10.8O30 are -203.63 ± 2.84 kJ/mol, - 358.02 ± 3.74 kJ/mol, and -1252.34 ± 10.10 kJ/mol, respectively, whereas from elements, ∆Hfel, for KTaO3, KTa2.2O6 and K6Ta10.8O30 are -1408.96 ± 3.73 kJ/mol, -2790.82 ± 6.06 kJ/mol, and -13393.04 ± 31.15 kJ/mol, respectively. The possible decomposition reactions of K-deficient KTa2.2O6 pyrochlore to KTaO3 perovskite and Ta2O5 (reaction 1) or to TTB K6Ta10.8O30 and Ta2O5 (reaction 2) were proposed, and the enthalpies were calculated to be 308.79 ± 4.41 kJ/mol and 895.79 ± 8.64 kJ/mol for reaction 1 and reaction 2, respectively. The reactions are strongly endothermic, indicating that these decompositions are energetically unfavourable, since it is unlikely that any entropy term could override such a large positive enthalpy. The energetic studies prove that pyrochlore is energetically more stable phase than perovskite at low temperature. Thus, the local order of the amorphous precipitates drives the crystallization into the most favourable structure that is the pyrochlore one with similar local organization; the distance between nearest neighbours in the amorphous or short-range ordered phase is very close to that in pyrochlore. Taking into account the stoichiometric deviation in KTO system, the selection of the most appropriate fabrication / deposition technique in thin films technology is a key issue, especially concerning complex ferroelectric oxides. Chemical solution deposition has been widely reported as a processing method to growth KTO thin films, but classical alkoxide route allows to crystallize perovskite phase at temperatures >800 °C, while the temperature endurance of platinized Si wafers is ~700 °C. Therefore, alternative diol-based routes, with distinct potassium carboxylate precursors, was developed aiming to stabilize the precursor solution, to avoid using toxic solvents and to decrease the crystallization temperature of the perovskite phase. Studies on powders revealed that in the case of KTOac (solution based on potassium acetate), a mixture of perovskite and pyrochlore phases is detected at temperature as low as 450 °C, and gradual transformation into monophasic perovskite structure occurs as temperature increases up to 750 °C, however the desired monophasic KTaO3 perovskite phase is not achieved. In the case of KTOacac (solution with potassium acetylacetonate), a broad peak is detected at temperatures <650 °C, characteristic of amorphous structures, while at higher temperatures diffraction lines from pyrochlore and perovskite phases are visible and a monophasic perovskite KTaO3 is formed at >700 °C. Infrared analysis indicated that the differences are due to a strong deformation of the carbonate-based structures upon heating. A series of thin films of alkali tantalates were spin-coated onto Si-based substrates using diol-based routes. Interestingly, monophasic perovskite KTaO3 films deposited using KTOacac solution were obtained at temperature as low as 650 °C; films were annealed in rapid thermal furnace in oxygen atmosphere for 5 min with heating rate 30 °C/sec. Other compositions of the tantalum based system as LiTaO3 (LTO) and NaTaO3 (NTO), were successfully derived as well, onto Si substrates at 650 °C as well. The ferroelectric character of LTO at room temperature was proved. Some of dielectric properties of KTO could not be measured in parallel capacitor configuration due to either substrate-film or filmelectrode interfaces. Thus, further studies have to be conducted to overcome this issue. Application-oriented studies have also been conducted; two case studies: i) photocatalytic activity of alkali tantalates and niobates for decomposition of pollutant, and ii) bioactivity of alkali tantalate ferroelectric films as functional coatings for bone regeneration. Much attention has been recently paid to develop new type of photocatalytic materials, and tantalum and niobium oxide based compositions have demonstrated to be active photocatalysts for water splitting due to high potential of the conduction bands. Thus, various powders of alkali tantalates and niobates families were tested as catalysts for methylene blue degradation. Results showed promising activities for some of the tested compounds, and KNbO3 is the most active among them, reaching over 50 % degradation of the dye after 7 h under UVA exposure. However further modifications of powders can improve the performance. In the context of bone regeneration, it is important to have platforms that with appropriate stimuli can support the attachment and direct the growth, proliferation and differentiation of the cells. In lieu of this here we exploited an alternative strategy for bone implants or repairs, based on charged mediating signals for bone regeneration. This strategy includes coating metallic 316L-type stainless steel (316L-SST) substrates with charged, functionalized via electrical charging or UV-light irradiation, ferroelectric LiTaO3 layers. It was demonstrated that the formation of surface calcium phosphates and protein adsorption is considerably enhanced for 316L-SST functionalized ferroelectric coatings. Our approach can be viewed as a set of guidelines for the development of platforms electrically functionalized that can stimulate tissue regeneration promoting direct integration of the implant in the host tissue by bone ingrowth and, hence contributing ultimately to reduce implant failure.

Revestimentos a base de Ta/Al2O3 produzidos por aspersão térmica sobre substrato metálico

Metal substrates were coated by thermal spraying plasma torch, they were positioned at a distance of 4 and 5 cm from the nozzle exit of the plasma jet. The starting materials were used for deposition of tantalum oxide powder and aluminium. These two materials were mixed and ground into high-energy mill, then immersed in the torch for the production of alumina coating infused with particles of tantalum with nano and micrometric size. The spraying equipment used is a plasma torch arc not transferred, which operating in the range of 250 A and 80 V, was able to produce enough heat to ignite aluminothermic between Ta2O5 and aluminum. Upon reaching the plasma jet, the mixing powders react with the heat of the blaze, which provides sufficient energy for melting aluminum particles. This energy is transferred through mechanisms of self-propagating to the oxide, beginning a reduction reaction, which then hits on the surface of the substrate and forms a coating on which a composite is formed by a junction metal - ceramic (Ta +Al2O3). The phases and quantification of each were obtained respectively by X-ray diffraction and the Rietveld method. Morphology by scanning electron microscopy and chemical analysis by energy dispersive spectroscopy EDS. It was also performed measurements of the substrate roughness, Vickers microhardness measurements in sprays and determination of the electron temperature of the plasma jet by optical emission spectroscopy EEO. The results confirmed the expectation generated around the end product of spraying the mixture Ta2O5 + Al, both in the formation of nano-sized particles and in their final form. The electron excitation temperature was consistent with the purpose of work, in addition, the thermodynamic temperature was efficient for the reduction process of Ta2O5. The electron excitation temperature showed values of 3000, 4500 and 8000 K for flows10, 20 and 30 l / min respectively, these values were taken at the nozzle exit of the plasma jet. The thermodynamic temperature around 1200 ° C, was effective in the reduction process of Ta2O5

Sinterização de matrizes cerâmicas à base de alumina reforçadas por carbetos a partir de precursores poliméricos

Ceramic composites produced with polymerics precursors have been studied for many years, due to the facility of obtaining a complex shape, at low temperature and reduces cost. The main objective of this work is to study the process of sintering of composites of ceramic base consisting of Al2O3 and silicates, reinforced for NbC, through the technique of processing AFCOP, as well as the influence of the addition of LZSA, ICZ and Al as materials infiltration in the physical and mechanical properties of the ceramic composite. Were produced ceramic matrix composites based SiCxOy e Al2O3 reinforced with NbC, by hidrosilylation reaction between D4Vi and D1107 mixtured with Al2O3 as inert filler, Nb and Al as reactive filler. The specimens produced were pyrolised at 1200, 1250 and 1400°C and infiltred with Al, ICZ and LZSA, respectively. Density, porosity, flexural mechanical strength and fracture surface by scanning electron microscopy were evaluated. The microstructure of the composites was investigated by X-ray diffraction to identify the presence of crystalline phases. The composites presented apparent porosity varying of 31 up to 49% and mechanical flexural strength of 14 up to 34 MPa. The infiltration process improviment of the densification and reduction of the porosity, as well as increased the values of mechanical flexural strength. The obtained phases had been identified as being Al3Nb, NbSi2, Nb5S3, Nb3Si and NbC. The samples that were submitted the infiltration process presented a layer next surface with reduced pores number in relation to the total volume

Prevalencia del carcinoma escamoso ocular y sus precursores en un hato lechero nicaraguense, relacionado con raza, edad y pigmentación

En el presente trabajo se estudió la prevalencia del Carcinoma escamoso ocular bovino y la relación que tiene esta enfermedad con la pigmentación ocular, la raza y la edad en la Empresa Genética “Roberto Alvarado” (Chiltepe). Para esto se estudiaron 4108 animales de los grupos raciales Holstein Friesian (Canadiense), Holstein Friesian (Criollo), Holstein x Pardo, 75% Holstein y Pardo Suizo. Se determinó que la prevalencia total del cáncer en la población analizada es de 2.6%. Además que existe presencia de lesión únicamente cuando existe pigmentación. Se concluyó que hay claras diferencias entre los grupos raciales estudiados siendo el más afectado el Holstein Friesian(Canadiense), y que hay una tendencia a incrementarse la presencia del cáncer a medida la edad.

Un testigo directo de las tensiones religiosas en la Alejandría de los siglos IV y V D.C. : Páladas de Alejandría en la Antología Palatina

Abstract: Although he is the most prolific writer of the Greek Anthology, Palladas’ life is almost unknown. But, in spite of the limited biographical data, his work has fortunately been preserved in the GA. Because of his literary creation, the old times rewarded him with the nickname Μετέωρος, high, since the literary merits of a hundred poems of his authorship was recognized (others are discussed by critics). A dozen of them contains invaluable information about the political, religious and social situation in Alexandria immediately after the victory of the bishop Theophilus, Cyril’s predecessor and uncle, during the conflict between Christians and Gentiles, each sector backed up by an Alexandrian population segment (cfr. 9.528, 10.82, 10.85) . Resigned at times, constantly demanding, Palladas complains about the decline of the belief professed by him due to the increasing penetration of the new faith. Therefore, four epigrams record the conversion of the temple of Tyche into a tavern (9.180-183) and 10.90 seems to attack the doctrine of the Resurrection. When religion and politics go hand-in-hand, when religious conspiracies link up with palace intrigues, consequences are predictable: a man called Doroteo denounced him for his negative response to the new dogma, which caused him the loss of his teacher paid work. His annoyance was even greater with further sufferings, chiefly economic, and he had to sell his books (9.171 and 9.175) among other desperate decisions Forewarned about his radical bitterness against Church, it is just to make clear that he is not fully acquiescent with ancient gods and heroes. Thus, in 5.257 he questions Zeus’ ars amandi, in 9.377 refutes Tantalus’ possibility of thirst and hunger in Hades and 9.773 mischievously points out that Eros has been changed into a pan. The work begins with the selection, personal translation and comprehensive analysis of twenty two epigrams. Through such philological aid, we attempt to verify the frictions and the main perceptible factors in his poetic creation to justify his worldview, according to the pagan sentiment widespread in that time before the twilight already overwhelming of its ailing traditions

Lereis, o Tántale en “Diálogos de los muertos” 7.2, análisis y traducción

Resumen: En Diálogos de los muertos 7 Menipo de Gádara intenta convencer a Tántalo de que su castigo, el tener sed en el Hades y no poder beber, es una mera ficción. Esta postura del gadarense se manifiesta claramente mediante el empleo del verbo ληρέω para describir el comportamiento de Tántalo (Dmort. 7.2). Lo que intentamos elucidar en el presente trabajo es si, desde la perspectiva de Menipo, dicha ficción se debe a una mentira intencional de Tántalo o a una enfermedad psíquica. De la interpretación que hagamos a este respecto dependerá la traducción del verbo ληρeω como ‘’decir tonterías’’ o ‘’delirar’’.

Paraiso dos contemplativos, opusculo devotissimo, e utilissimo para as almas que aspirão a perfeição espiritual, e vida contemplativa : composto pelo V. Padre Fr. Batholomeu de Salucio, religioso da Serafica Familia dos Observantes Reformados : traduzido de italiano, e ilustrado com anotações pelo Padre Manoel Bernardes, da Congregação do Oratorio da cidade de Lisboa : offerecido a V. Santissima senhora nossa, concebida nos resplendores da Divina Graça sem sombra de culpa original

Bartholomeu de Salucio nasceu na Itália em 1558, não se sabe exatamente onde. Viveu em Roma, onde morreu em 1617. Frei franciscano foi orador e místico. Escreveu muitas obras espirituais tais como, As Sete Trombetas, As Invenções do Amor Divino, e O Namorado de Jesus, que foram traduzidas para o francês pelo Padre Carlos Jouya e impressas em Rouen, no ano de 1623. O Paraiso dos Contemplativos... é um dialogo entre um filho espiritual e o seu Diretor, com perguntas e respostas, orações e exclamações. É como uma história de peregrinação do espírito em busca da perfeição. As doutrinas são mostradas nas figuras do diálogo. O tradutor Manuel Bernardes fez anotações para ilustrar as metáforas que pudessem parecer obscuras e para confirmar' as doutrinas que pudessem parecer novas. Segundo Inocêncio, "parece que o coletor do pseudo-catálogo da Academia ignorou a existência da edição de 1739, aliás, não deixaria de citá-la de preferência à de 1761, que é a indicada no catálogo.

Tratado dos descobrimentos antigos, e modernos : feitos ate a era de 1550 com os nomes particulares das pessoas que os fizerão : e em que tempos, e as suas alturas, e dos desvairados caminhos por onde a pimenta, e especiaria veyo da india as nossas partes, obra certo muy notavel, e copiosa : composto pelo Famoso Antonio Galvão ; offerecido ao excellentissimo senhor Dom Luiz de Menezes

Antônio Galvão, filho de Duarte Galvão, excedeu em fama e imaginação a se pai e a seu avô, Rui Galvão. Nasceu na Índia Oriental, em 1490, e morreu em 1557.

Vestigios da lingua arabica em portugal, ou, lexicon ethimologico das palavras, e nomes portuguezes, que tem origem arabica : composto por ordem da academia real das sciencias de Lisboa

Esta obra é uma das mais importantes do autor. Esta primeira edição apresenta, em ordem alfabética, os termos em três grafias : português, em caracteres arábicos e na forma portuguesa da palavra árabe; em seguida, fornece a origem e os diferentes signifcados da palavra. Os termos são marcados com asterisco quando antigos e menos usados. Existe uma segunda edição, em 1830, que, segundo, Inocêncio, é superior a esta.

Pequeno cathecismo historico :contendo em compendio a historia sagrada, doutrina cristã /composto em francez pelo Abbade Fleury ; e traduzido em portuguez de ordem do Governo Imperial por Joaquim José da Silveira

Referência: Diccionario Bibliographico Brazileiro / Augusto Victorino Alves Sacramento Blake, 1899. v. 4, p. 179.