Caracterização multi-escalar de bandas de deformação nas tectonossequências paleozóica, pré- e sin-rifte da Bacia do Araripe, Nordeste do Brasil

Deformation bands are structures, developed in porous sandstones, that has small offsets and they are not shown on seismic section. The deformation bands of the pre and synrift sandstones of Araripe Basin were studied in outcrop, macroscopic and microscopic scales. The hierarchical, cinematic and spatial-geometric characteristics, and also the deformational mechanisms acting during its structural evolution were established too. In general, the mesoscopic scale observation allowed to discriminate deformation bands as singles or clusters in three main sets: NNE-SSW dextral; NE-SW normal (sometimes with strike-slip offset); and E-W sinistral; further a bed-parallel deformation bands as a local set. The microscopic characterization allowed to recognize the shearing and cataclastic character of such structures. Through the multi-scale study done in this work we verified that deformation bands analyzed were preferentially developed when sandstones under advanced stage of lithification. We also infer that the geometrical-spatial complexity of these bands, together with the presence of cataclastic matrix, can difficult the migration of fluids in reservoir rocks, resulting on their compartmentalization. Therefore, the study of deformation bands can aid researches about the structural evolution of sedimentary basin, as well as collaborate to understand the hydrodynamic behavior of reservoirs compartmented by these deformational structures

Aproveitamento da fibra do epicarpo do coco babaçu em compósito com matriz epóxi: estudo do efeito do tratamento da fibra

Nowadays the environmental issues are increasingly highlighted since the future of humanity is dependent on the actions taken by man. Major efforts are being expended in pursuit of knowledge and alternatives to promote sustainable development without compromising the environment. In recent years there has been a marked growth in the development of reinforced composite fiber plants, as an alternative for economic and ecological effects, especially in the substitution of synthetic materials such as reinforcement material in composites. In this current study the chemical- physical or (thermophysics )characteristics of the babassu coconut fiber, derived from the epicarp of the fruit (Orbignyda Phalerata), which the main constituents of the fiber: Klason lignin, insoluble, cellulose, holocellulose, hemicellulose and the content of ash and moisture will be determined. A study was conducted about the superficial modification of the fibers of the epicarp babassu coconut under the influence of chemical treatment by alkalinization, in an aqueous solution of NaOH to 2.5% (m/v) and to 5.0% to improve the compatibility matrix / reinforcement composite with epoxy matrix. The results of the changes occurred in staple fibers through the use of the techniques of thermogravimetric analyses (TG) and differential scanning calorimetry (DSC). The results found on thermal analysis on samples of fiber without chemical treatment (alkalinities), and on fiber samples treated by alkalinization show that the proposed chemical treatment increases the thermal stability of the fibers and provides a growth of the surface of area fibers, parameters that enhance adhesion fiber / composite. The findings were evaluated and compared with published results from other vegetable fibers, showing that the use of babassu coconut fibers has technical and economic potential for its use as reinforcement in composites

Adição de nanopartículas de Ti em matriz de Fe através da deposição por magnetron sputtering

Microalloyed steels constitute a specific class of steel with low amount of carbon and microalloying elements such as Vanadium (V), Niobium (Nb) and Titanium (Ti). The development and application of microalloyed steels and steels in general are limited to the handling of powders with particles of submicron or nanometer dimensions. Therefore, this work presents an alternative in order to construction of microalloyed steels utilizing the deposition by magnetron sputtering technique as a microalloying element addiction in which Ti nanoparticles are dispersed in an iron matrix. The advantage of that technique in relation to the conventional metallurgical processes is the possibility of uniformly disperse the microalloying elements in the iron matrix. It was carried out deposition of Ti onto Fe powder in high CH4, H2, Ar plasma atmosphere, with two deposition times. After the deposition, the iron powder with nanoparticles of Ti dispersed distributed, were compacted and sintered at 1120 ° C in resistive furnace. Characterization techniques utilized in the samples of powder before and after deposition of Ti were Granulometry, Scanning Electron Microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX) and X-ray diffraction (DRX). In the case of sintered samples, it was carried out characterization by SEM and Vickers Microhardness assays. The results show which the deposition technique by magnetron sputtering is practicable in the dispersion of particles in iron matrix. The EDX microanalysis detected higher percentages of Ti when the deposition were carried out with the inert gas and when the deposition process was carried out with reactive gas. The presence of titanium in iron matrix was also evidenced by the results of X-ray diffraction peaks that showed shifts in the network matrix. Given these results it can be said that the technique of magnetron sputtering deposition is feasible in the dispersion of nanoparticles of iron matrix in Ti.

Tratamentos de fibras de carnaúba [copernicia prunífera (miller) h. e. moore] para o desenvolvimento de compósito biodegradável com matriz de polihidroxibutirato

The use of raw materials from renewable sources for production of materials has been the subject of several studies and researches, because of its potential to substitute petrochemical-based materials. The addition of natural fibers to polymers represents an alternative in the partial or total replacement of glass fibers in composites. In this work, carnauba leaf fibers were used in the production of biodegradable composites with polyhydroxybutyrate (PHB) matrix. To improve the interfacial properties fiber / matrix were studied four chemical treatments to the fibers..The effect of the different chemical treatments on the morphological, physical, chemical and mechanical properties of the fibers and composites were investigated by scanning electron microscopy (SEM), infrared spectroscopy, X-ray diffraction, tensile and flexural tests, dynamic mechanical analysis (DMA), thermogravimetry (TGA) and diferential scanning calorimetry (DSC). The results of tensile tests indicated an increase in tensile strength of the composites after the chemical treatment of the fibers, with best results for the hydrogen peroxide treated fibers, even though the tensile strength of fibers was slightly reduced. This suggests a better interaction fiber/matrix which was also observed by SEM fractographs. The glass transition temperature (Tg) was reduced for all composites compared to the pure polymer which can be attributed to the absorption of solvents, moisture and other low molecular weight molecules by the fibers

Comportamento magnético de compósitos de matriz polimérica com adição de ferritas

Polymer matrix composites offer advantages for many applications due their combination of properties, which includes low density, high specific strength and modulus of elasticity and corrosion resistance. However, the application of non-destructive techniques using magnetic sensors for the evaluation these materials is not possible since the materials are non-magnetizable. Ferrites are materials with excellent magnetic properties, chemical stability and corrosion resistance. Due to these properties, these materials are promising for the development of polymer composites with magnetic properties. In this work, glass fiber / epoxy circular plates were produced with 10 wt% of cobalt or barium ferrite particles. The cobalt ferrite was synthesized by the Pechini method. The commercial barium ferrite was subjected to a milling process to study the effect of particle size on the magnetic properties of the material. The characterization of the ferrites was carried out by x-ray diffraction (XRD), field emission gun scanning electron microscopy (FEG-SEM) and vibrating sample magnetometry (VSM). Circular notches of 1, 5 and 10 mm diameter were introduced in the composite plates using a drill bit for the non-destructive evaluation by the technique of magnetic flux leakage (MFL). The results indicated that the magnetic signals measured in plates with barium ferrite without milling and cobalt ferrite showed good correlation with the presence of notches. The milling process for 12 h and 20 h did not contribute to improve the identification of smaller size notches (1 mm). However, the smaller particle size produced smoother magnetic curves, with fewer discontinuities and improved signal-to-noise ratio. In summary, the results suggest that the proposed approach has great potential for the detection of damage in polymer composites structures

Comportamento da adição do carbeto de nióbio (nBC) na matriz metálica do aço ferrítico 15kH2mfa

The 15Kh2MFA steel is a kind of Cr-Mo-V family steels and can be used in turbines for energy generation, pressure vessels, nuclear reactors or applications where the range of temperature that the material works is between 250 to 450°C. To improve the properties of these steels increasing the service temperature and the thermal stability is add a second particle phase. These particles can be oxides, carbides, nitrites or even solid solution of some chemical elements. On this way, this work aim to study the effect of addition of 3wt% of niobium carbide in the metallic matrix of 15Kh2MFA steel. Powder metallurgy was the route employed to produce this metallic matrix composite. Two different milling conditions were performed. Condition 1: milling of pure 15Kh2MFA steel and condition 2: milling of 15Kh2MFA steel with addition of niobium carbide. A high energy milling was carried out during 5 hours. Then, these two powders were sintered in a vacuum furnace (10-4torr) at 1150 and 1250°C during 60 minutes. After sintering the samples were normalized at 950°C per 3 minutes followed by air cooling to obtain a desired microstructure. Results show that the addition of niobium carbide helps to mill faster the particles during the milling when compared with that steel without carbide. At the sintering, the niobium carbide helps to sinter increasing the density of the samples reaching a maximum density of 7.86g/cm³, better than the melted steel as received that was 7,81g/cm³. In spite this good densification, after normalizing, the niobium carbide don t contributed to increase the microhardness. The best microhardness obtained to the steel with niobium carbide was 156HV and to pure 15Kh2MFA steel was 212HV. It happened due when the niobium carbide is added to the steel a pearlitic structure was formed, and the steel without niobium carbide submitted to the same conditions reached a bainitic structure

Estudo da adição de resíduo de scheelita em matriz cerâmica: formulação, propriedades físicas e microestrutura

Extractivism mineral is considered an activity highly degrading, due to the large volume of material that he moves in the form of ore and residues. The vast majority of mining companies do not show any technology or economically viable application that will allow the recycling of mineral residue, these being launched in areas receiving located the "open skies" degrade the environment. In Rio Grande do Norte to the production of ceramic red restricts their activities to the production of products such as: solid bricks, ceramic blocks, tiles, among others. Seeking to unite experiences and technical information that favor sustainable development, with important benefits to the construction sector and civil society in general, the present work studies the incorporation of the residue of scheelite in ceramic matrix kaolinitic, coming from the municipality of Boa Saúde - RN, in percentage of 5 %, 10 %, 20 %, 30% 40% and 50 %, by evaluating its microstructure, physical properties and formulation. The raw materials were characterized through the trials of X ray fluorescence, Diffraction of X rays, Differential Thermal Analysis and Termogravimetric Analysis. The samples were formed and fired at temperatures of 850o, 900o, 1000o, 1050o, 1100o, 1150o and 1200 oC, with isotherm of 1 hour and heating rate of 10 oC/min. Assays were performed technological of loss to fire, Water Absorption, Apparent Porosity, Apparent Density, Mass Loss in Fire and Bending Resistance; in addition to the Scanning Electron Microscopy, analyzing their physical and mechanical properties. The use of residue of scheelite in ceramic mass kaolinitic provided a final product with technological properties that meet the technical standards for the production of bricks and roofing tiles, with the percentage of 20% of waste that showed the best results

Desenvolvimento e caracterização de um compósito matriz metálica (CMM): aço EUROFER97 reforçado com Carbeto de Tântalo - TaC

Steel is an alloy EUROFER promising for use in nuclear reactors, or in applications where the material is subjected to temperatures up to 550 ° C due to their lower creep resistance under. One way to increase this property, so that the steel work at higher temperatures it is necessary to prevent sliding of its grain boundaries. Factors that influence this slip contours are the morphology of the grains, the angle and speed of the grain boundaries. This speed can be decreased in the presence of a dispersed phase in the material, provided it is fine and homogeneously distributed. In this context, this paper presents the development of a new material metal matrix composite (MMC) which has as starting materials as stainless steel EUROFER 97, and two different kinds of tantalum carbide - TaC, one with average crystallite sizes 13.78 nm synthesized in UFRN and another with 40.66 nm supplied by Aldrich. In order to improve the mechanical properties of metal matrix was added by powder metallurgy, nano-sized particles of the two types of TaC. This paper discusses the effect of dispersion of carbides in the microstructure of sintered parts. Pure steel powders with the addition of 3% TaC UFRN and 3% TaC commercial respectively, were ground in grinding times following: a) 5 hours in the planetary mill for all post b) 8 hours of grinding in the mill Planetary only for steel TaC powders of commercial and c) 24 hours in the conventional ball mill mixing the pure steel milled for 5 hours in the planetary mill with 3% TaC commercial. Each of the resulting particulate samples were cold compacted under a uniaxial pressure of 600MPa, on a cylindrical matrix of 5 mm diameter. Subsequently, the compressed were sintered in a vacuum furnace at temperatures of 1150 to 1250 ° C with an increment of 20 ° C and 10 ° C per minute and maintained at these isotherms for 30, 60 and 120 minutes and cooled to room temperature. The distribution, size and dispersion of steel and composite particles were determined by x-ray diffraction, scanning electron microscopy followed by chemical analysis (EDS). The structures of the sintered bodies were observed by optical microscopy and scanning electron accompanied by EDS beyond the x-ray diffraction. Initial studies sintering the obtained steel EUROFER 97 a positive reply in relation to improvement of the mechanical properties independent of the processing, because it is obtained with sintered microhardness values close to and even greater than 100% of the value obtained for the HV 333.2 pure steel as received in the form of a bar

Efeito da adição de grafite expandido por microondas nas propriedades térmicas, elétricas e mecânicas de nanocompósitos de matriz epóxi

Epoxy based nanocomposites with 1 wt % and 3 wt % of nanographite were processed by high shear mixing. The nanographite was obtained by chemical (acid intercalation), thermal (microwave expansion) and mechanical (ultrasonic exfoliation) treatments. The mechanical, electrical and thermal behavior of the nanocomposites was determined and evaluated as a function of the percentage of reinforcement. According to the experimental results, the electrical conductivity of epoxy was not altered by the addition of nanographite in the contents evaluated. However, based on the mechanical tests, nanocomposites with addition of 1 wt.% and 3 wt.% of nanographite showed increase in tensile strength of 16,62 % and 3,20 %, respectively, compared to the neat polymer. The smaller increase in mechanical strength of the nanocomposite with 3 wt.% of nanographite was related to the formation of agglomerates. The addition of 1 wt.% and 3 wt.% of nanographite also resulted in a decrease of 6,25 % and 17,60 %, respectively, in the relative density of the material. Thus, the specific strength of the nanocomposites was approximately 33,33 % greater when compared to the neat polymer. The addition of 1 wt.% and 3 wt.% of nanographite in the material increased the mean values of thermal conductivity in 28,33 % and 132,62 %, respectively, combined with a reduction of 26,11 % and 49,80 % in volumetric thermal capacity, respectively. In summary, it has been determined that an addition of nanographite of the order of 1 wt.% and 3 wt.% produced notable elevations in specific strength and thermal conductivity of epoxy

Compósitos de matriz metálica à base níquel com adição de TaC e NbC produzidos via metalurgia do pó

Carbide reinforced metallic alloys potentially improve some important mechanical properties required for the overall use of important engineering materials such as steel and nickel. Nevertheless, improved performance is achieved not only by composition enhancement but also by adequate processing techniques, such as novel sintering methods in the case of powder metallurgy. The method minimizes energy losses in addition to providing uniform heating during sintering. Thus, the general objective of this study was to evaluate the density, hardness, flexural strength, dilatometric behavior and to analyze the microstructure of metal matrix composites based nickel with addition of carbides of tantalum and / or niobium when sintered in a conventional furnace and Plasma assisted debinding and sintering (PADS). Initially, were defineds best parameters of granulation, screening and mixing procedure. After, mixtures of carbonyl Ni and 5%, 10% and 15 wt.% NbC and TaC were prepared in a Y-type mixer under wet conditions during 60 minutes. The mixtures were then dried and granulated using 1.5 wt. % paraffin diluted in hexane. Granulates were cold pressed under 600 MPa. Paraffin was then removed from the pressed pellets during a pre-sintering process carried out in a tubular furnace at 500 °C during 30 min. The heating rate was 3 ºC/min. The pellets were then sintered using either a plasma assisted reactor or a conventional resistive tubular furnace. For both methods, the heating rate was set to 8 ºC/min up to 1150 °C. The holding time was 60 minutes. The microstructure of the sintered samples was evaluated by SEM. Brinell hardness tests were also carried out. The results revealed that higher density and higher hardness values were observed in the plasma-assisted sintered samples. Hardness increased with the concentration of carbides in the Ni-matrix. The flexural strength also increased by adding the carbides. The decline was larger for the sample with addition of 5% 5% TaC and NbC. In general, compositions containing added carbide 10% showed less porous and more uniform distribution of carbides in the nickel matrix microstructural appearance. Thus, both added carbide and plasma sintering improved density, hardness, flexural strength and microstructural appearance of the composites

Efeito da adição de fibras da palma do licuri (syagrus coronata) no comportamento físico e mecânico de compósitos de matriz cimentícia

This research was motivated by the requirement of asbestos s replacement in building systems and the need to generate jobs and income in the country side of the state of Bahia, Brazil. The project aimed at using fibers from licuri leaves (syagrus coronata), an abundant palm in the region, to produce composites appropriate for the sustainable production of cement fibre reinforced products in small plants. The composites were produced in laboratory using Portland cement CP-II-F32, sand, water, licuri palm fiber contents of 1.0, 1.5 and 2.0% by weight of binder (two different fiber length) and metakaolin. The latter was chosen as an additional binder for its efficiency to reduce the alkalinity of cementitious matrixes therefore preventing the degradation of vegetable fibers. The characterization of the composite components was carried out by sieving and laser particle size analyses, thermal analysis, fluorescence and X-ray diffraction. The composites performance was evaluated by 3- point-bending tests, compressive strength, ultrasound module of elasticity, free and restrained shrinkage, water capillarity absorption and apparent specific gravity. It has been found that the addition of fibers increased the time to onset of cracking over 200.00% and a 25% reduction in cracks opening in the restrained shrinkage test. The capillary absorption reduced about 25% when compared to fiber-free composites. It was also observed with regard to flexural strength, compressive strength and specific gravity, that the addiction of fibers did not affect the composite performance presenting similar results for compounds with and without fibers. In general it can be stated that the reinforced composite fibers of palm licuri presents physical and mechanical characteristics which enable them to be used in the intended proposals of this research

Bandas de música, escolas de vida

The focus of this dissertation is to understand the child and youth musical learning trajectory by using two philharmonic orchestras from Seridó, an area in the interior of Rio Grande do Norte. One is called the Hermann Gmeiner Philharmonic Orchestra of Aldeias Infantis SOS Project from Caicó, and the other is the 24 de Outubro Philharmonic Orchestra from Cruzeta. It emphasizes the singular relationship between the band s master and his students, based on a permanent interaction with tradition, creativity and change, resulting from a shared educational process. The idea that unites the work of these two communities is the gamble about the individual's formation as a complex human being, which it is not just concerned with the learning of a musical instrument, but is, more importantly, an educational process capable of facilitating the discovery of the self, others and society. The history and the course of the musical education of these two experiences were facilitated using a base of semi-structured interviews of the bands masters, students and people from two municipal districts. Their history is understood through analysis of the band s pictures and the theoretical-social approach is governed by the complexity idea expressed by Edgar Morin. For the author, complex means to `weave together`; therefore it is multidimensional, and it creates a dialogue about several domains and aspects that occur on the same phenomenon. The complex always supposes creativity and the relationship between the subject s reason and affectivity

O corpo como matriz pedagógica

The contemporary conjuncture based on the capitalistic knowledge converges to the corporal consciousness that makes us see, feel, taste and hear, be in/to pieces. Disembodied reason legitimate and legislate ways of being and living socially and its development is the dehumanization of human relations causing pain and suffering. The objective of this work is to discuss the body as pedagogical matrix through imagistic/artistic elements: music, painting and literature. Metaphors lead to self knowledge of human subjectivity and approach us to the kaleidoscope of sensitive knowledge and enables learning to learn with the infinite combinations of images, knowledge, feelings and worldviews. The song Memória da Pele comes in the voice of Maria Betânia speak of the memories that are not mine, but are tattooed in me in the memory of skin, singing the memories of a love lived by who tries to forget rationally, but the body insists on remembering. It is password to think about what we are. The short story by Clarice Lispector, entitled Miss Algarve, narrates the life story of an unmarried and virgin woman, and her encounter with an alien called Ixtlan. Until then, she who lived as if every day were a Monday, found herself seduced by the pleasure of having a body in contact with another body, which also allowed her to give visibility to the bodies of others. She had repudiation by the immorality that her body and the other s perspired. The discovery of the body brings important lessons for nursing, involving our body and the others'. The painting the flying bed or Henry Ford Hospital, by Frida Kahlo, is our final metaphor. The traumatic experience of abortion is shown in this painting trough the picture of the artist naked in a hospital bed. This painting invites us to reflect on our work process. We need to think in multiple dimensions of the being and accept the invitation of art, so that the lightness confronts us with the weight imposed by the hegemonic ideology. I believe it is not a single view, but the many views that should justify the knowledge and practices of nursing; what matters is that they are woven into the dialogue, democracy, provided that protagonism of those individuals involved in this process, in the wandering and uncertainty, in the rewiring, solidarity, plurality. To this end, the body must be the great pedagogue that is able to be viewed not as a tapestry seen by the right view, as the logical knowledge sees, but seen by the opposite side in its singular, irregular, discontinuous weavings

Análise do balanço energético e da matriz de emissões de poluentes no Estado do Rio Grande do Norte

This thesis intends to show the level of pollutant emissions in the State of Rio Grande do Norte, generated by the final consumption of energy in the many different sectors of the economy. This information was obtained from the energetic matrix and from the pollutant emissions of the State and the data was taken from the Balanço Energético Estadual and from the Sistema de Informações Energéticas da Olade. The result will permit to identify the energy and most polluting economic sectors in Rio Grande do Norte, contributing to energy planning, giving direction to the public policy development that aim at the change of the energy matrix of the State. Also with the objective of reducing pollutant emissions through rationalization, efficiency and energy substitution, which the main objective is to promote the economic development based on energy consumption of less harmful impact on the environment, contributing to establishment of sustainable development

Compressão auto-adaptativa de imagens coloridas

Image compress consists in represent by small amount of data, without loss a visual quality. Data compression is important when large images are used, for example satellite image. Full color digital images typically use 24 bits to specify the color of each pixel of the Images with 8 bits for each of the primary components, red, green and blue (RGB). Compress an image with three or more bands (multispectral) is fundamental to reduce the transmission time, process time and record time. Because many applications need images, that compression image data is important: medical image, satellite image, sensor etc. In this work a new compression color images method is proposed. This method is based in measure of information of each band. This technique is called by Self-Adaptive Compression (S.A.C.) and each band of image is compressed with a different threshold, for preserve information with better result. SAC do a large compression in large redundancy bands, that is, lower information and soft compression to bands with bigger amount of information. Two image transforms are used in this technique: Discrete Cosine Transform (DCT) and Principal Component Analysis (PCA). Primary step is convert data to new bands without relationship, with PCA. Later Apply DCT in each band. Data Loss is doing when a threshold discarding any coefficients. This threshold is calculated with two elements: PCA result and a parameter user. Parameters user define a compression tax. The system produce three different thresholds, one to each band of image, that is proportional of amount information. For image reconstruction is realized DCT and PCA inverse. SAC was compared with JPEG (Joint Photographic Experts Group) standard and YIQ compression and better results are obtain, in MSE (Mean Square Root). Tests shown that SAC has better quality in hard compressions. With two advantages: (a) like is adaptive is sensible to image type, that is, presents good results to divers images kinds (synthetic, landscapes, people etc., and, (b) it need only one parameters user, that is, just letter human intervention is required