Estudo da adesão de pinos endodônticos modificados superficialmente por plasma de oxigênio

The work presents the effect of plasma treatment when applied in fibers or carbon/glass posts in the adhesion fiber/resin and posts/cement. This has for objective the modification of the surface of the fibers, as well as the wettability of the posts, seeking the improvement of the adhesion and of the connection fiber/resin in the processing of polymeric composites reinforced with the same ones. 120 posts (Reforpost) were used and 30 meters of fibers of carbon and of glass (Fibrex), of the company Angelus. The samples were divided in three groups of 40 specimens: GROUP I - 20 posts of glass fiber and 20 of carbon without treatment to it shapes, GROUP II -20 posts of glass fiber and 20 of carbon treated to it shapes in the surface and GROUP III - 20 posts of glass fiber and 20 of carbon make with fibers in natura after plasma treatment. The plasma treatment was accomplished with oxygen and with temperature in the camera fixed at 200°C, for one hour of exhibition. The posts and the fibers were characterized before and after the treatment. The wettability was measure by pendent drop method, and interface fiber/resin and posts/cement were observed by optical and electronic microscopy. It was observed that both wettability and texture were increased with plasma treatment

Avaliação de concretos reforçados por confinamento com manta de fibra de vidro estrutural e pré-impreganada

Due to the occurrence of diseases in the use of structural reinforcements in composites, with presentation of concrete blanket detachment, has been identified the need to evaluate the performance of concrete reinforced with glass fiber. This study aims to evaluate these concretes by means of testing methodologies, using concrete with low resistance with structural reinforcement for confinement by preimpregnated glass fiber and traditional fiberglass blanket. The first stage of work was the development of methodologies for analysis, opting for four types, such as the acoustic survey, strength to compressive, the pull-off and ultrasound. Next, tests were carried out using the four selected methodologies in 30 of proof-of-specimens by 5x10 cm, 15 were reinforced with the traditional fiberglass blanket with 5specimens exposed to test a marine environment of marine coastline of Natal-RN and 15 were reinforced with a pre-impregnated glass fiber blanket, as well as 5specimens exposed to a test environment of the marine coastline of Natal-RN. After conducting the acoustic survey, it has been verified a lack of delaminating and air bubbles in the samples, confirming the absence of gross shortcomings in the implementation of the ribs both the traditional fiberglass blanket and in the preimpregnated fiber glass blanket. After carrying out methods of pull-off and compressive strengthening test it was observed that the reinforced proof-bodies with pre-impregnated glass blanket showed maximum stresses higher than the traditional fiberglass blanket; consequently a greater grip with the formation of a smaller area of . fracture, unlike traditional glass mat, which showed lower maximum stresses, with a greater area of fracture. It was also found that the traditional fiberglass blanket presented detachment of blanket-concrete interface, unlike the pre-impregnated fiberglass blanket, which showed a better grip on the blanket-concrete interface. In the trial of ultrasound there was no presence of cracks in the blanket-concrete interface, yielding to both blankets good compactness of the concrete. At the end of this work, they were developed and proposed two methods of testing for evaluation of reinforced concrete structures with composites, for standardization, the acoustic survey and pull-off

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

Estudo comparativo de pás para aerogeradores de grande porte fabricadas em materiais compósitos reforçadas com fibra de carbono ou fibra de vidro

The research and development of wind turbine blades are essential to keep pace with worldwide growth in the renewable energy sector. Although currently blades are typically produced using glass fiber reinforced composite materials, the tendency for larger size blades, particularly for offshore applications, has increased the interest on carbon fiber reinforced composites because of the potential for increased stiffness and weight reduction. In this study a model of blade designed for large generators (5 MW) was studied on a small scale. A numerical simulation was performed to determine the aerodynamic loading using a Computational Fluid Dynamics (CFD) software. Two blades were then designed and manufactured using epoxy matrix composites: one reinforced with glass fibers and the other with carbon fibers. For the structural calculations, maximum stress failure criterion was adopted. The blades were manufactured by Vacuum Assisted Resin Transfer Molding (VARTM), typical for this type of component. A weight comparison of the two blades was performed and the weight of the carbon fiber blade was approximately 45% of the weight of the fiberglass reinforced blade. Static bending tests were carried out on the blades for various percentages of the design load and deflections measurements were compared with the values obtained from finite element simulations. A good agreement was observed between the measured and calculated deflections. In summary, the results of this study confirm that the low density combined with high mechanical properties of carbon fibers are particularly attractive for the production of large size wind turbine blades

Compósitos poliméricos a base de fibras de licuri: efeitos da hibridização e do envelhecimento ambiental acelerado

The gradual replacement of conventional materials by the ones called composite materials is becoming a concern about the response of these composites against adverse environmental conditions, such as ultraviolet radiation, high temperature and moist. Also the search for new composite using natural fibers or a blend of it with synthetic fibers as reinforcement has been studied. In this sense, this research begins with a thorough study of microstructural characterization of licuri fiber, as a proposal of alternative reinforcement to polymeric composites. Thus, a study about the development of two composite laminates was done. The first one, involving only the fiber of licuri and the second comprising a hybrid composite based of fiber glass E and the fiber of licuri, in order to know the performance of the fiber when of fiber across the hybridization process. The laminates were made in the form of plates using the tereftálica ortho-polyester resin as matrix. The composite laminate made only by licuri fiber had two reinforcing fabric layers of unidirectional licuri and the hybrid composite had two reinforcing layers of unidirectional licuri fabric and three layers of fiber short glass-E mat. Finally, both laminates was exposed to aging acceleration in order to study the influence of environmental degradation involving the mechanical properties and fracture characteristics thereof. Regarding the mechanical properties of composites, these were determined through uniaxial tensile tests, uniaxial compression and three bending points for both laminates in original state, and uniaxial tensile tests and three bending points after accelerated aging. As regards the study of structural degradation due to aging of the laminates, it was carried out based on microscopic analysis and microstructure, as well as measuring weight loss. The characteristics of the fracture was performed by macroscopic and microscopic (optical and SEM) analysis. In general, the laminated composites based on fiber licuri showed some advantages in their responses to environmental aging. These advantages are observed in the behavior related to stiffness as well as the microstructural degradation and photo-oxidation processes. However, the structural integrity of this laminate was more affected in case the action of uniaxial tensile loads, where it was noted a lower rate of withholding his last resistance property

Pathogenicity of Metarhizium anisopliae for Ceratitis capitata (Wied.) (Diptera: Tephritidae) in soil with different pesticides

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Placas de aço inoxidável 316L aplicadas no reparo de fratura experimental diafisária do rádio e ulna de cães

O objetivo do presente trabalho foi o de estudar a resistência à corrosão em placas de aço inoxidável 316L, com diferentes tipos de acabamento e tratamento superficial, e a possível interferência dessa reação corrosiva na consolidação óssea. Utilizaram-se placas semi-acabadas, polidas, tratadas com jatos de microesferas de vidro e passivadas, as quais foram aplicadas na epífise distal do rádio de cães. Foram utilizados 12 animais, divididos em dois grupos, nos quais, após osteotomia bilateral do rádio e ulna, foram realizadas osteossínteses do rádio, totalizando 24 procedimentos. Avaliou-se a evolução clínica e radiográfica das regiões que receberam os implantes aos 30, 60, 90, 180, 240 e 360 dias. Os animais do grupo 1 (GI) foram sacrificados aos 180 dias e os do GII aos 360 dias para estudo histológico e de microscopia eletrônica de varredura do local da osteotomia sob a região dos implantes metálicos e para estudo da resistência à corrosão no organismo, pelos implantes metálicos, por meio de análises química e metalográfica (microscopia óptica e eletrônica de varredura e espectroscopia de espalhamento de energia por raios X). Os animais recuperaram a função dos membros operados 24 horas após a cirurgia. Radiograficamente, verificou-se a consolidação óssea em todos os animais. Macro e microscopicamente não foram observados sinais de corrosão nos implantes metálicos, exceto em uma placa passivada, aplicada no rádio esquerdo de um animal, na qual a corrosão foi detectada pela microscopia óptica e eletrônica de varredura. Este estudo permite concluir que as placas de aço inoxidável 316L, independente do acabamento superficial a que foram submetidas, não sofreram corrosão ou reações adversas e foram efetivas no tratamento das fraturas experimentais do rádio e ulna de cães.

Potencial de alimentação de Chrysoperla externa (Hagen, 1861) (Neuroptera, Chrysopidae) em diferentes densidades de Uroleucon ambrosiae (Thomas, 1878) (Hemiptera, Aphididae)

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

Efeito de diferentes dietas sobre o desenvolvimento pós-embrionário de Chrysoperla defreitasi Brooks (Neuroptera: Chrysopidae)

Avaliou-se o período pós-embrionário do predador Chrysoperla defreitasi Brooks alimentada com ovos de Sitotroga cerealella (Olivier) e Diatraea saccharalis (Fabricius) em condições de laboratório à temperatura de 25±2ºC, UR de 70±10% e fotofase de 14h. Os ovos do crisopídeo foram individualizados em tubos de vidro e, após a eclosão, as larvas foram alimentadas com as respectivas presas e mantidas em sala climatizada, sob condições controladas. O delineamento estatístico utilizado foi inteiramente casualizado com 150 repetições para cada dieta. As durações do 1º, 2º e 3º ínstar e da fase pupal foram, respectivamente, 3,4, 2,7, 3,5 e 11,9 dias para larvas alimentadas com D. saccharalis e 3,6, 2,8, 2,7 e 9,3 dias, quando a dieta oferecida foi ovos de S. cerealella. Larvas de crisopídeos alimentados com ovos de D. saccharalis levaram em média 21,5 dias para completar o desenvolvimento pós-embrionário, com 34,0% de adultos emergidos, enquanto que os alimentados com ovos de S. cerealella levaram 18,4 dias com 55,3% de adultos. Pode-se, pois, constatar que a melhor dieta para o desenvolvimento pós-embrionário de C. defreitasi foram os ovos de S. cerealella, sendo que insetos alimentados com esta dieta apresentaram período mais curto de desenvolvimento, maior viabilidade nos três ínstares larvais e no período pupal, produzindo maior número de adultos.

Efeito de genótipos de sorgo sobre o predador Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) alimentado com Schizaphis graminum (Rondani) (Hemiptera: Aphididae)

O trabalho objetivou avaliar o efeito indireto da resistência de genótipos de sorgo sobre o predador Chrysoperla externa (Hagen) usando o pulgão Schizaphis graminum (Rondani) como presa. Os genótipos usados no estudo foram: GR 11111 e TX 430 x GR 111 (resistentes), GB 3B (moderadamente resistente) e BR 007B (suscetível). Larvas recém-eclodidas foram confinadas individualmente em recipientes de vidro e alimentadas com S. graminum, criados separadamente em cada um dos quatro genótipos. Após a emergência, os adultos obtidos de cada tratamento foram sexados e agrupados aos casais, colocados em gaiolas contendo dieta à base de levedo de cerveja e mel. Os insetos foram observados diariamente da fase jovem até o período de 60 dias após a emergência do adulto. Genótipos com maior grau de resistência proporcionaram maior consumo de pulgões pelo predador, porém menor peso a este. Quando os pulgões foram criados no genótipo resistente GR 11111, o peso das larvas, sobrevivência da pré-pupa e longevidade da fêmea do predador foram inferiores. As associações positivas observadas entre o predador, C. externa, e o genótipo resistente, TX 430 x GR 111, e entre o predador e o genótipo moderadamente resistente GB 3B, evidenciaram a possibilidade de integração entre os dois métodos de controle: resistência de plantas e controle biológico.

Seletividade Fisiológica de Endossulfam e Deltametrina às Operárias de A. chartifex spiriti For. (Hymenoptera: Formicidae) em Agroecossistema Cacaueiro do Sudeste da Bahia

Avaliou-se o efeito dos inseticidas endossulfam e deltametrina sobre a formiga predadora Azteca chartifex spiriti For., em cultivo do cacaueiro no Sudeste da Bahia, conforme padronização da International Organization for Biological and Integrated Control (IOBC), West Palaearctic Regional Section (WPRS), com algumas modificações. Os testes foram: a) contato; b) pulverização direta; c) persistência. Nos testes de contato, operárias foram expostas a um filme fresco e seco dos inseticidas, aplicado sobre cristalizadores. Nos testes de aspersão, as formigas foram diretamente pulverizadas com os agroquímicos às concentrações recomendadas para o controle de tripes e percevejos. Os insetos foram mantidos a 25±2°C, 65±10% UR e fotofase de 12h. A sobrevivência foi avaliada após 24h e a intervalos variáveis de tempo. Nos testes de persistência, as operárias foram confinadas em cristalizadores e expostas ao contato com folhas de cacaueiro tratadas previamente no campo, sob as mesmas condições controladas. Desenvolveram-se experimentos a um, três, seis, 10, 18 e 32 dias após a aplicação (DAA). Deltametrina foi considerado seletivo nos testes de contato e pulverização direta, não sendo necessária a condução dos testes de persistência em folhas para este inseticida. Endossulfam foi altamente tóxico nos testes de contato e pulverização direta, entretanto, apresentou-se levemente persistente no terceiro teste. A análise conjunta dos três tipos de testes sugere que ambos os inseticidas são seletivos para a espécie benéfica, podendo ser recomendadosem Programas de MIP em agroecossistema cacaueiro. A metodologia proposta pela IOBC/WPRS possibilita estabilidade dos resultados, permitindo sua adaptação e utilização para o fim proposto.

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

Arranjo de antenas de microfita com substrato anisotrópico com patch supercondutor e aplicações em nanotecnologia

The main objective in this work is the analysis of resonance frequency microstrip structures with glass fiber and electromagnetic band gap (EBG/PBG) substrate and analysis of microstrip antennas with rectangular patch of superconductor of high critical temperature (HTS). In this work was used the superconductors YBCO (critical temperature of 90K), SnBaCaCuOy (critical temperature of 160K), and Sn5InCa2Ba4Cu10Oy (critical temperature of 212K) with results in Gigahertz and Terahertz. Was used microstrip antennas arrays planar and linear phase and linear phase planar with patch with superconductor. It presents a study of the major theories that explain superconductivity. In phase arrays were obtained the factors arrays for such configurations, and the criteria of phase and spacing between the elements compound in the array, which were examined in order to get a main lobe with high directivity and high gain. In the analysis we used the method of Transverse Transmission Line (TTL) used in domain of the Fourier Transform (FTD). The LTT is a full wave method, which obtains the electromagnetic field in terms of the components transverse of the structure. The addition of superconductive patch is made using the boundary condition resistive complex. Results are obtained resonance frequency as a function of the parameters of the antenna, radiation patterns of the E and H Planes, for the phase antenna arrays in linear and planar configurations, for different values of the phase and the spacing between elements

Compósitos híbridos: desenvolvimento de configuração e efeitos de umidificação

The advantage in using vegetable fibres in place of synthetic fibres such as glass fibre, for reinforcements in composites are: biodegradability, low cost, low density, good tenacity, good thermal properties, low energy content and reduced use of instruments for its treatment or processing. Even though, problems related to low mechanical performance of some of the natural fibres, has caused difficulty in their direct application in structural elements. The use of alternative materials like hybrid composites has been encouraged, thus trying to better the structural performance of the composites with natural fibres. This work presents a comparative study of the strength and stiffness of hybrid composites with orthopthalic polyester matrix reinforced with E-fibre glass, jute and curauá. The experimental part includes uniaxial tension and three point bending tests to determine the mechanical properties of the final product. The hybrid composite was manufactured in a local industry and was in the form of laminates. All the samples were projected to withstand the possible structural applications as reservoirs and pipes. CH (laminated hybrid composite with glass and curauá fibres). The results obtained show clearly the influence of the hybridization in all the types tested and indicate a good mechanical performance of the composite with glass/curauá fibres in relation to the composite with glass fibres. Aspects in relation to the interfaces glass/curauá composites besides the fracture characteristics for all loading types were also analysed

Efeitos do envelhecimento ambiental acelerado em compósitos poliméricos

The advantages of the use of vegetable fibers on the synthetic fibers, such as glass fibers, in the reinforcements in composites are: low cost, low density, good tenacity, good thermal properties and reduced use of instruments for their treatment or processing. However, problems related to poor performance of some mechanical natural fibers, have hindered its direct use in structural elements. In this sense, the emergence of alternative materials such as hybrids composites, involving natural and synthetic fibers, has been encouraged by seeking to improve the performance of structural composites based only on natural fibers. The differences between the physical, chemical and mechanical properties of these fibers, especially facing the adverse environmental conditions such as the presence of moisture and ultraviolet radiation, is also becoming a concern in the final response of these composites. This piece of research presents a comparative study of the strength and stiffness between two composite, both of ortoftalic polyester matrix, one reinforced with fibers of glass-E (CV) and other hybrid reinforced with natural fibers of curauá and fiberglass-E (CH). All the comparative study is based on the influence of exposure to UV rays and steam heated water in composites, simulating the aging environment. The conditions for the tests are accelerated through the use of the aging chamber. The composites will be evaluated through tests of uniaxial static mechanical traction and bending on three points. The composite of glass fiber and hybrid manufacturing industry are using the rolling manual (hand lay-up) and have been developed in the form of composites. All were designed to meet possible structural applications such as tanks and pipes. The reinforcements used in composites were in the forms of short fiber glass-E quilts (450g/m2 - 5cm) of continuous wires and fuses (whose title was of 0.9 dtex) for the curauá fibers. The results clearly show the influence of aging on the environmental mechanical performance of the composite CV and CH. The issues concerning the final characteristics of the fracture for all types of cargoes studied were also analyzed