Membrana de alumina anódica: comportamento da microestrutura e estudo das propriedades ópticas após tratamento térmico

Thin commercial aluminum electrolytic and passed through reactions was obtained with anodic alumina membranes nanopores. These materials have applications in areas recognized electronic, biomedical, chemical and biological weapons, especially in obtaining nanostructures using these membranes as a substrate or template for processing nanowires, nanodots and nanofibers for applications noble. Previous studies showed that the membranes that have undergone heat treatment temperature to 1300° C underwent changes in morphology, crystal structure and optical properties. This aim, this thesis, a study of the heat treatment of porous anodic alumina membranes, in order to obtain and to characterize the behavior changes structures during the crystallization process of the membranes, at temperatures ranging between 300 and 1700° C. It was therefore necessary to mount a system formed by a tubular furnace resistive alumina tube and controlled environment, applying flux with special blend of Ag-87% and 13% N2, in which argon had the role of carrying out the oxygen nitrogen system and induce the closing of the pores during the densification of the membrane. The duration of heat treatment ranged from 60 to 15 minutes, at temperatures from 300 to 1700° C respectively. With the heat treatment occurred: a drastic reduction of porosity, grain growth and increased translucency of the membrane. For the characterization of the membranes were analyzed properties: Physical - thermogravimetric, X-ray diffraction, BET surface area; morphological - SEM, EDS through compositional and, optical absorbance, and transmittance in the UV-VIS, and FTIR. The results using the SEM showed that crystallization has occurred, densification and significant changes in membrane structure, as well as obtaining microtube, the BET analysis showed a decrease in specific surface area of the membranes has to 44.381 m2.g-1 to less than 1.8 m2.g-1 and in the analysis of transmittance and absorbance was found a value of 16.5% in the range of 800 nm, characteristic of the near infrared and FTIR have confirmed the molecular groups of the material. Thus, one can say that the membranes were mixed characteristics and properties which qualify for use in gas filtration system, as well as applications in the range of optical wavelength of the infra-red, and as a substrate of nanomaterials. This requires the continuation and deepening of additional study

Construção de um aparato experimental para monitoramento in situ da deposição de filmes finos de titânio por magnetron sputtering

The technique of surface coating using magnetron sputtering is one of the most widely used in the surface engineering, for its versatility in obtaining different films as well as in the micro / nanometric thickness control. Among the various process parameters, those related to the active species of the plasma are of the most fundamental importance in the mechanism and kinetics of deposition. In order to identify the active species of the plasma, parameters such as gas flow, pressure and density of electric power were varied during titanium coating on glass substrate. By flowing argon gas of 10, 20, 30, 40 and 50 sccm (cubic centimeters per minute) for each gas flow a sequential scan of the electric current of 0.10, 0.20, 0.30, 0.40 , 0.50 A. The maximum value of 0.50 A was chosen based both on literature data and on limitations of the equipment. The monitoring of plasma species present during the deposition was carried out in situ by the technique of optical emission spectroscopy (OES) through the spectrometer Ocean Optics USB2000 Series. For this purpose, an apparatus was developed to adapt the OES inside the plasma reactor to stay positioned closest to the target. The radiations emitted by the species were detected by an optical fiber placed behind the glass substrate and their intensities as a function of wavelength were, displayed on a monitor screen. The acquisition time for each condition of the plain parameters was related to the minima of spectral lines intensities due to the film formed on the substrate. The intensities of different emission lines of argon and titanium were then analyzed as a function of time, to determine the active species and estimate the thickness of the deposited films. After the deposition, the coated glasses thin films were characterized by optical transmittance through an infrared laser. It was found that the thickness and deposition rate determined by in situ analysis were consistent with the results obtained by laser transmittance

Implementação do algoritmo (RTM) para processamento sísmico em arquiteturas não convencionais

With the growth of energy consumption worldwide, conventional reservoirs, the reservoirs called "easy exploration and production" are not meeting the global energy demand. This has led many researchers to develop projects that will address these needs, companies in the oil sector has invested in techniques that helping in locating and drilling wells. One of the techniques employed in oil exploration process is the reverse time migration (RTM), in English, Reverse Time Migration, which is a method of seismic imaging that produces excellent image of the subsurface. It is algorithm based in calculation on the wave equation. RTM is considered one of the most advanced seismic imaging techniques. The economic value of the oil reserves that require RTM to be localized is very high, this means that the development of these algorithms becomes a competitive differentiator for companies seismic processing. But, it requires great computational power, that it still somehow harms its practical success. The objective of this work is to explore the implementation of this algorithm in unconventional architectures, specifically GPUs using the CUDA by making an analysis of the difficulties in developing the same, as well as the performance of the algorithm in the sequential and parallel version

Controle de qualidade físico-químico e biodisponibilidade relativa em ratos de suspensões orais de naproxeno sódico obtidas de farmácias de manipulação na cidade do Natal RN

Compounded medicines have been reported by the ANVISA due to decreased of the therapeutic response or toxicity of these formulations. The aim of this work was to investigate the physicochemical quality control among naproxen sodium oral suspensions 25 mg/mL obtained from six compounding pharmacies (A, B, C, D, E and F) and the manufactured suspension (R). In the quality control test, the tests of pH, content, homogeneity, volume and physical and organoleptic characteristics were performed according to the Brazilian Pharmacopoeia. The analytical method for determination of naproxen in suspensions was validate. This method showed excellent precision, accuracy, linearity and specificity. In the content test the suspensions B, C and E showed lower value and the F suspension showed a high value of the content. The products C and E were disapproved in the description of the physical and organoleptic characteristics test. In the pH test, three suspensions were outside specifications (C, E and F). Only the products R, A and D showed satisfactory results in these tests and therefore they were approved for relative bioavailability test. The R, A and D suspensions were orally administered to Wistar rats and the blood samples were taken at time intervals of 10, 20, 40, 60 min, 3, 4, 6, 24 and 48 h. The plasma samples were immediately stored at 80 ºC until analysis of HPLC. The bioanalytical method validation showed specificity, linearity (R2 0.9987), precision, accuracy, good recovery and stability. The chromatographic conditions were: flow rate of 1.2 mL.min-1 with a mobile phase of acetonitrile : sodium phosphate buffer pH 4.0 (50:50, v/v) at 280 nm, using a C18 column. The confidence interval of 90% for the Cmax and AUCt ratio was within the range of 80 - 125% proposed by the FDA. Only one suspension, obtained from the compounding pharmacy D, was considered bioequivalent to the rate of absorption under the conditions proposed by this study. Thus, the results indicate the need for strict supervision from the relevant authorities to ensure the patient safety and the quality of compounded drugs by pharmacies

Clinical evaluation of enalapril maleate and furosemide usage in dogs with degenerative myxomatous mitral valve, CHF functional class Ib

A doença degenerativa mixomatosa da válvula mitral (DDMVM) é uma cardiopatia de alta incidência na clínica médica de pequenos animais, acometendo mormente cães idosos e raças de pequeno porte. Desta forma, foi realizada uma investigação científica objetivando avaliar clinicamente a utilização dos fármacos maleato de enalapril e furosemida em cães com a referida enfermidade na classe funcional Ib da ICC, antes e após a terapêutica implantada. Para isso, utilizaram-se 16 cães portadores da valvulopatia supracitada, distribuídos em dois grupos; com o primeiro recebendo furosemida (n=8) e o segundo maleato de enalapril (n=8), durante 56 dias. Os cães foram avaliados em quatro momentos (T0, T14, T28 e T56 dias) quanto aos sinais clínicos e parâmetros hematológicos e bioquímico-séricos, que incluíram concentrações séricas da enzima conversora da angiotensina (ECA) e aldosterona, como também avaliações radiográficas, eletrocardiográficas, ecodopplercardiográficas e da pressão arterial. Os resultados quanto aos parâmetros clínicos, avaliações hematológicas e bioquímicas séricas não revelaram alterações significativas em ambos os grupos, mas reduções significativas nos valores de ECA e aldosterona no grupo que recebeu o maleato de enalapril foram identificadas. Ao exame radiográfico observou-se reduções nos valores de VHS e na variável onda Pms do eletrocardiograma em ambos os grupos, mas sem alterações nos valores da pressão arterial. Por sua vez, o ecodopplercardiograma evidenciou diminuição significativa das variáveis DIVEd/s nos grupos estudados e na FEC% nos cães que receberam somente enalapril. Portanto, a análise dos resultados encontrados indicou que a monoterapia fundamentada no maleato de enalapril apresentou melhor eficiência no controle do quadro clínico em pacientes da classe funcional Ib da ICC.

Transmissão de Radiação Ultravioleta Através do Pelame e da Epiderme de Bovinos

A transmissão de radiação ultravioleta de comprimentos de onda entre 250 e 360 nm através do pelame e da epiderme de bovinos foi determinada em laboratório, usando-se amostras de couro de animais recém-abatidos. A quantidade de radiação transmitida através do pelame depende da coloração e também das características estruturais do pelame (espessura da capa; comprimento, diâmetro, número e inclinação dos pêlos), pelas quais é definido o trajeto médio de um fóton pela massa de pêlos (L). A maior transmissão é proporcionada por pelames brancos com altos valores de L, ao passo que pelames negros em geral apresentam transmissão nula ou muito baixa. Quanto menos pigmentada a epiderme, maior a transmissão de radiação através da sua superfície. A melhor proteção é proporcionada por pelames negros com baixo valor de L sobre epiderme igualmente negra, mas em vista do aquecimento causado pela absorção de radiação térmica (em vacas Holandesas a temperatura das malhas negras atinge 44,1ºC ao mesmo tempo em que a das malhas brancas é 37,7ºC), a combinação ideal para ambientes tropicais é um pelame branco com baixo valor de L sobre epiderme negra, uma combinação dificilmente encontrada em animais de raças européias. Uma alternativa seria um pelame negro com um baixo valor de L. Animais vermelhos apresentam alta transmissão de radiação UV através da epiderme e do pelame, sendo desaconselhados para ambientes tropicais. Entretanto, foi observada uma vaca Holandesa com áreas isoladas de epiderme negra coberta com pelame branco, o que pode trazer perspectivas para uma seleção para combinações mais adequadas de epiderme e pelame em bovinos de raças européias.

Eletrocardiografia computadorizada em cães da raça Beagle

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

Mestres e aprendiz: perambulando por ilhas de resistência

Monoculture of mind This idea, presented by Vandana Shiva, reflects the phase that we have experienced in the world: a notion of civilization that, since many decades, characterized by a technocratic big trend, has been shown as dominant and hegemonic. Based on a thinking and acting, felling and whishing standardization, this wave ends implying in what can be called of humanity‟s crisis at civilizational process. Destruction of simpler and more harmonious lifestyles with nature, human relations increasingly distant, values embrittlement, as respect, goodness and love, are some consequences of that behavioral homogenization. In the other hand, appears an archipelago of cultural and cognitive resistance against this devastating wave. Edgar Morin and Ceiça Almeida refer to this archipelago as a South Thought , what is not just a geographic question. Report, therefore, to some places, peoples, island that keep ancient costumes and knowledge, orally transmitted, for instance, from elders to younger, or vice versa, in an almost constant flow. Particular ways of experiencing the world around themselves, the men, animals, plants, rocks, or even not alive beings, masters or enchanted, spiritual guides. Next to a logic of sensitive, as Claude Levi-Strauss proposes, this reading, which is a more attentive, observer and wiser posture of surroundings, is based on touching, smelling, eating, seeing, and, I would add, felling. In light of this, I try to expatiate about certain experiences that I had the pleasure of living in some of these islands of resistance. Talks, perceptions, observations, sensations Stories, prose, poetries, music, photos, graphics Whatever could serve to portray even a bit of the reflections and forms to understand (ourselves) and produce knowledge, such as from a formation/Education to life, was well used at this ethnographic work. Space to the subjectivity and emotions I had, have, and will have a lot Everything for the dear reader may fell traveling around the world of tradition, resistance

Qualidade em obras públicas: um estudo comparativo entre as metodologias Seis Sigma, ISO 9000 e PBQP-H no RN

In Brazil the theme quality in public construction has been widely discussed in the early 1990s, with the creation of the Brazilian Program of Quality and Productivity for the Habitat (PBQP-H) which is strongly influenced by the wave of studies on issues of quality in the world, such as the ISO 9000. Over the years, other approaches have emerged and been consolidated, evolving from market and customer´s needs. An example is the Six Sigma methodology. This study aims to examine the Six Sigma, ISO 9000 and PBQP-H methodologies, noting the common elements, differences, gaps and how the methods are complementary, so that with the ongoing work, proposed initiatives can be developed to improve the quality that enables its application in public construction. Still aiming to optimize the deployment of the proposed initiatives, it was performed an analysis of ISO 9001 and PBPQ-H certifications in Brazil and in the state of Rio Grande do Norte, with respect to the construction industry and a case study to identify the factors that influence the adoption of initiatives to improve quality, and check if the selected construction company is prepared to implement the proposed initiatives. This research is characterized as exploratory and applied, with literature review and a case study. The data collection instrument was a questionnaire and the statistical analysis used a multidimensional scaling method. The conclusion is that the methodologies are compatible and complementary, and their integration could potentialize the goals set. It was identified that the state of Rio Grande do Norte has a few number of certifications in construction. Nine initiatives are proposed for implementation at construction companies. In the case study it was found that the studied company would be able to implement the suggestions proposed and the requirement for certification by clients and funding institutions influence the adoption of quality improvement initiatives. This result confirms the literature which states that top management support is crucial for the successful implementation of quality methodologies

Análise e otimização de superfícies seletivas de Frequência utilizando redes neurais artificiais e algoritmos de otimização natural

The bidimensional periodic structures called frequency selective surfaces have been well investigated because of their filtering properties. Similar to the filters that work at the traditional radiofrequency band, such structures can behave as band-stop or pass-band filters, depending on the elements of the array (patch or aperture, respectively) and can be used for a variety of applications, such as: radomes, dichroic reflectors, waveguide filters, artificial magnetic conductors, microwave absorbers etc. To provide high-performance filtering properties at microwave bands, electromagnetic engineers have investigated various types of periodic structures: reconfigurable frequency selective screens, multilayered selective filters, as well as periodic arrays printed on anisotropic dielectric substrates and composed by fractal elements. In general, there is no closed form solution directly from a given desired frequency response to a corresponding device; thus, the analysis of its scattering characteristics requires the application of rigorous full-wave techniques. Besides that, due to the computational complexity of using a full-wave simulator to evaluate the frequency selective surface scattering variables, many electromagnetic engineers still use trial-and-error process until to achieve a given design criterion. As this procedure is very laborious and human dependent, optimization techniques are required to design practical periodic structures with desired filter specifications. Some authors have been employed neural networks and natural optimization algorithms, such as the genetic algorithms and the particle swarm optimization for the frequency selective surface design and optimization. This work has as objective the accomplishment of a rigorous study about the electromagnetic behavior of the periodic structures, enabling the design of efficient devices applied to microwave band. For this, artificial neural networks are used together with natural optimization techniques, allowing the accurate and efficient investigation of various types of frequency selective surfaces, in a simple and fast manner, becoming a powerful tool for the design and optimization of such structures

Desenvolvimento de antenas de microfita com Patch em anel utilizando materiais ferrimagnéticos e metamateriais

In general, the materials used as substrates in the project of microstrip antennas are: isotropic, anisotropic dielectrics and ferrimagnetic materials (magnetic anisotropy). The use of ferrimagnetic materials as substrates in microstrip patch antennas has been concentrated on the analysis of antennas with circular and rectangular patches. However, a new class of materials, called metamaterials, has been currently the focus of a great deal of interest. These materials exhibit bianisotropic characteristics, with permittivity and permeability tensors. The main objective of this work is to develop a theoretical and numerical analysis for the radiation characteristics of annular ring microstrip antennas, using ferrites and metamaterials as substrates. The full wave analysis is performed in the Hankel transform domain through the application of the Hertz vector potentials. Considering the definition of the Hertz potentials and imposing the boundary conditions, the dyadic Green s function components are obtained relating the surface current density components at the plane of the patch to the electric field tangential components. Then, Galerkin s method is used to obtain a system of matrix equations, whose solution gives the antenna resonant frequency. From this modeling, it is possible to obtain numerical results for the resonant frequency, radiation pattern, return loss, and antenna bandwidth as a function of the annular ring physical parameters, for different configurations and substrates. The theoretical analysis was developed for annular ring microstrip antennas on a double ferrimagnetic/isotropic dielectric substrate or metamaterial/isotropic dielectric substrate. Also, the analysis for annular ring microstrip antennas on a single ferrimagnetic or metamaterial layer and for suspended antennas can be performed as particular cases

Análise dos Modos Ressonantes em Antenas de Microfita sobre Substratos Iso/Anisotrópicos por Técnicas da Ressonância Transversa

Neste trabalho, são utilizadas a Técnica da Ressonância Transversa (TRT) e a Técnica da Ressonância Transversa Modificada (MTRT), para a determinação das freqüências dos modos ressonantes de antenas de microfita com patch quadrado, retangular e circular e com substratos isotrópicos e anisotrópicos. Para isso, é proposto um modelo da cavidade equivalente, onde a antena tipo patch retangular é representada como sendo a superposição de duas linhas infinitas em microfita, uma de largura W, representando a dimensão que expressa a largura do patch, e a outra com largura L, representando a dimensão que expressa o comprimento do patch. A avaliação da eficiência e aplicabilidade dos métodos citados é realizada comparando-se com resultados experimentais e obtidos através de outras técnicas. Três situações serão verificadas: estruturas com substrato infinito, estrutura com substrato tipo pedestal e estruturas com substrato truncado além dos limites da fita metálica. Os resultados obtidos demonstram que as técnicas de análise de onda completa utilizadas neste trabalho, por um formalismo matemático mais rigoroso, são eficientes e precisas tanto na aplicação em estruturas com substrato isotrópico como nas que possuem substrato anisotrópico. Inicialmente são consideradas apenas as estruturas com substratos isotrópicos, com diferentes constantes dielétricas, e é avaliada a influência da largura do substrato sobre as freqüências dos modos ressonantes das antenas. Posteriormente, a análise do truncamento do dielétrico é realizada para estruturas com substrato anisotrópico. Em todos os casos, os resultados experimentais, obtidos a partir da construção de protótipos, são confrontados com os obtidos a partir de simulação, utilizando as técnicas TRT e MTRT. No final, as técnicas descritas são utilizadas para antenas tipo patch circular, sendo utilizada uma técnica de equivalência para transformar a antena circular em outra quadrada ou retangular equivalente, dependendo do modo que se queira encontrar. Os resultados obtidos são então analisados, observando-se uma boa concordância e indicando a viabilidade do método. Após isso, são apresentadas as conclusões e sugeridos alguns temas para a continuidade deste trabalho

Dispositivos planares integrados utilizando método dinâmico com metamateriais e PBG

This work presents a theoretical, numerical and computation analysis of parameters of a rectangular microstrip antenna with metamaterial substrate, fin line as a coupler and also integrated devices like integrated filter antenna. It is applied theory to full-wave of Transverse Transmission Line - TTL method, to characterize the magnitude of the substrate and obtain the general equations of the electromagnetic fields. About the metamaterial, they are characterized by permittivity and permeability tensor, reaching to the general equations for the electromagnetic fields of the antenna. It is presented a study about main representation of PBG(Photonic Band Gap) material and its applied for a specific configuration. A few parameters are simulated some structures in order to reduce the physical dimensions and increase the bandwidth. The results are presented through graphs. The theoretical and computational analysis of this work have shown accurate and relatively concise. Conclusions are drawn and suggestions for future work

Análise e síntese de antenas e superfícies seletivas de frequência utilizando computação evolucionária e inteligência de enxames

The frequency selective surfaces, or FSS (Frequency Selective Surfaces), are structures consisting of periodic arrays of conductive elements, called patches, which are usually very thin and they are printed on dielectric layers, or by openings perforated on very thin metallic surfaces, for applications in bands of microwave and millimeter waves. These structures are often used in aircraft, missiles, satellites, radomes, antennae reflector, high gain antennas and microwave ovens, for example. The use of these structures has as main objective filter frequency bands that can be broadcast or rejection, depending on the specificity of the required application. In turn, the modern communication systems such as GSM (Global System for Mobile Communications), RFID (Radio Frequency Identification), Bluetooth, Wi-Fi and WiMAX, whose services are highly demanded by society, have required the development of antennas having, as its main features, and low cost profile, and reduced dimensions and weight. In this context, the microstrip antenna is presented as an excellent choice for communications systems today, because (in addition to meeting the requirements mentioned intrinsically) planar structures are easy to manufacture and integration with other components in microwave circuits. Consequently, the analysis and synthesis of these devices mainly, due to the high possibility of shapes, size and frequency of its elements has been carried out by full-wave models, such as the finite element method, the method of moments and finite difference time domain. However, these methods require an accurate despite great computational effort. In this context, computational intelligence (CI) has been used successfully in the design and optimization of microwave planar structures, as an auxiliary tool and very appropriate, given the complexity of the geometry of the antennas and the FSS considered. The computational intelligence is inspired by natural phenomena such as learning, perception and decision, using techniques such as artificial neural networks, fuzzy logic, fractal geometry and evolutionary computation. This work makes a study of application of computational intelligence using meta-heuristics such as genetic algorithms and swarm intelligence optimization of antennas and frequency selective surfaces. Genetic algorithms are computational search methods based on the theory of natural selection proposed by Darwin and genetics used to solve complex problems, eg, problems where the search space grows with the size of the problem. The particle swarm optimization characteristics including the use of intelligence collectively being applied to optimization problems in many areas of research. The main objective of this work is the use of computational intelligence, the analysis and synthesis of antennas and FSS. We considered the structures of a microstrip planar monopole, ring type, and a cross-dipole FSS. We developed algorithms and optimization results obtained for optimized geometries of antennas and FSS considered. To validate results were designed, constructed and measured several prototypes. The measured results showed excellent agreement with the simulated. Moreover, the results obtained in this study were compared to those simulated using a commercial software has been also observed an excellent agreement. Specifically, the efficiency of techniques used were CI evidenced by simulated and measured, aiming at optimizing the bandwidth of an antenna for wideband operation or UWB (Ultra Wideband), using a genetic algorithm and optimizing the bandwidth, by specifying the length of the air gap between two frequency selective surfaces, using an optimization algorithm particle swarm

Bianisotropia uniaxial em estruturas irradiantes com multicamadas e supercondutores

This work presents a theoretical and numerical analysis of parameters of a rectangular microstrip antenna with bianisotropic substrate, and including simultaneously the superconducting patch. The full-wave Transverse Transmission Line - TTL method, is used to characterize these antennas. The bianisotropic substrate is characterized by the permittivity and permeability tensors, and the TTL gives the general equations of the electromagnetic fields of the antennas. The BCS theory and the two fluids model are applied to superconductors in these antennas with bianisotropic for first time. The inclusion of superconducting patch is made using the complex resistive boundary condition. The resonance complex frequency is then obtained. Are simulated some parameters of antennas in order to reduce the physical size, and increase the its bandwidth. The numerical results are presented through of graphs. The theoretical and computational analysis these works are precise and concise. Conclusions and suggestions for future works are presented