Avaliação do comportamento tribológico de compósitos poliéster/fibra de vidro utilizando resíduos de poliéster/fibra de vidro e carbonato de cálcio como carga

The use of composite materials and alternative is being increased every day, as it becomes more widespread awareness that the use of renewable and not harmful to the environment is part of a new environmentally friendly model. Since its waste (primarily fiberglass) can not be easily recycled by the difficulty that still exists in this process, since they have two phases mixed, a polymeric matrix thermoset difficult to recycle because it is infusible and phase of fiber reinforcements. Thermoset matrix composites like Polyester + fiberglass pose a threat due to excessive discharge. Aiming to minimize this problem, aimed to reuse the composite Polyester + fiber glass, through the wastes obtained by the grinding of knifes and balls. These residues were incorporated into the new composite Polyester/Fiberglass for hot compression mold and compared tribological to composites with filler CaCO3, generally used as filler, targeting a partial replacement of CaCO3 by such waste. The composites were characterized by thermal analysis (TGA, DSC and DMA), by the surface integrity (roughness determination, contact angle and surface energy), mechanical properties (hardness) and tribological tests (wear and coefficient of dynamic friction) in order to evaluate the effect of loads and characterize these materials for applications that can take, in the tribological point of view since waste Polyester + fiberglass has great potential for replacement of CaCO3

Avaliação físico-química e funcional da algaroba prosopis juliflora proveniente da mesorregião agreste do Rio Grande do Norte

Algaroba (Prosopis juliflora) is a typical legume from arid and semi arid regions, which is composed by sugar-rich pods and high protein seeds. Phenolic compounds are secondary metabolites recognized as potent bioactive compounds, found in several vegetables.Therefore, the objective of this work is to characterize the algaroba flour in terms of its physicalchemical composition, total phenolic content, antioxidant activity by DPPH and ABTS methods, a-amylase and a-glycosidase inhibition, as well as to analyze its organic compounds by high performance liquid chromatography (HPLC). Three experimental groups were investigated (seeds, seeds and pod together and only pod), which were prepared by oven drying and posterior grinding. Water and ethanol extracts (70, 80, 100% v/v) were prepared and used for functional studies. Organic compounds were detected by using HPLC equipment coupled to mass spectrometer. Results show important physical-chemical differences among the experimental groups, seeds, seeds and pod together and only pod. The algarroba seed flour is high in protein (49.49%) and fat (3.10%), while the pod flour is especially rich in sugar (60.3% to 67.9%). Algaroba phenolics are concentrated in pod flour, mainly in water extracts (1.30 mg GAEQ/100g sample). All seed extracts showed high DPPH activity and maximum antioxidant activity was registered for ethanol 80% extracts (19.81 μM Trolox/g sample). The ABTS activity ranged from 9.73 to 12.74 μM Trolox/g sample. Nearly all the extracts were able to inhibit α-amylase activity mildly (30.50% to 48.80%), while the maximum α-glycosidase inhibition was observed for pod water extracts (81.03%). Algaroba water extracts proven to be especially rich in organic compounds, observed by the high number of chromatographic peaks. Results demonstrate that algaroba is a potential candidate for further investigations concerning its possible functional applications

Interação no rádio: a participação do ouvinte no programa debates do povo

The radio is just not seen as conveying information, but a media able to establish ways that generate certain direction. We see an inclusion of the listener in the construction of programs, is exposing their life stories, commenting on facts, answering questions, choosing subjects and participating in some form of radio programming. This insertion of the listener in radio programs is generally thought of as a constituent element of the message. This study aims to analyze the participation of the listener and the forms of interaction in the " Debates of the People" that thirty- past two years is the schedule for CBN Fortaleza. The investigation was conducted through observation in studio, interview, transcription, content analysis and association analysis. This is a qualitative and quantitative research while. We found that the listeners of the program had no acceptance of interactive tools such as the Internet and social networks to make their holdings. In clipping analyzed, we noted that the participation of the listener was selected according to their relationship and proximity to the topic discussed. Also detected that the opinion is superior to the listener questions on the topic. The presenter has the function to put the questions in the listener program. Among the public comments are questions and opinions on the subject and speaks of the debaters. Among the authors, use Barbosa (2009 ), Ferraretto (2007 ), Lopez (2010 ), Ortriwano (2001 ), Peruzzo (2004 ), Prata (2009 ), Primo (2006 ), Thompson (2009 ), among others

Plasticidade induzida por treinamento locomotor na medula espinal intacta em ratos: correlatos morfológicos

The locomotion is one of the most important capabilities developed by the animals, whose improvement is dependent on several neural centers, including the spinal cord. This activity promotes a lot of spinal modifications that enable it to adapt and improve their connections. This study aimed to observe the morphological changes occurring in the spinal cord after locomotor training in intact rats. For that we used male Wistar rats, which were submitted to locomotor training in wheel activity in protocols 1, 3 and 7 days (30min/day), and the results were compared to a control group not subjected to exercise. Coronal sections of 40 μm of the lumbosacral spinal cord were subjected to immunohistochemical techniques anti-Egr1, anti-NMDA and anti-SP, to characterize the spinal plasticity related to these substances. Egr1-immunoreactive cells were increased in all laminas, essentially in those more intensely activated by locomotion, laminas IV-X levels L4-S3. All observed sections expressed NMDA-immunoreactivity. Analysis of SP in the spinal dorsal horn resulted no significant variations of this neuropeptide related to locomotion. The results suggest that locomotor training provides synaptic plasticity similar to LTP in all laminas of the lumbosacral spinal cord, in different intensities. However, the SP appears do not participate of this process in the spinal dorsal horn. This work will contribute for consolidating and characterization of synaptic plasticity in the spinal cord

Analysis of forecasting capabilities of ground surfaces valuation using artificial neural networks

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

Cerâmicas avançadas no processo de retificação cilíndrica externa de mergulho utilizando a técnica da mínima quantidade de lubrificação (MQL) com rebolos diamantados

Nas últimas duas décadas, as cerâmicas avançadas têm sido exaustivamente utilizadas em aplicações na indústria devido às suas propriedades de elevada resistência ao desgaste e dureza. Entretanto, ainda se tem um alto custo agregado ao acabamento da peça. Esse acabamento geralmente é feito pelo processo de retificação, único processo economicamente viável que produz superfícies de elevada qualidade e precisão geométrica. Nesse contexto, as empresas vêm buscando a otimização no processo de retificação como, por exemplo, a redução do fluxo de fluido de corte utilizado, o que também visa atender exigências mundiais de preservação ambiental. Desta forma, este projeto pretendeu explorar a técnica da Mínima Quantidade de Lubrificação (MQL) na retificação cilíndrica externa de mergulho em cerâmicas com rebolos diamantados. Foram utilizados dois métodos de refrigeração: o convencional e o MQL, com três avanços de corte para cada caso. Foram usados um bocal convencional e um bocal para o MQL, tendo este um uniformizador de saída do jato. Foram analisadas como variáveis de saída: a emissão acústica, relação G, aspecto da superfície via microscopia eletrônica de varredura (MEV), rugosidade e circularidade. Assim, embora a refrigeração convencional ainda apresente os melhores resultados em comparação com a refrigeração com MQL, esta última pode atender os requisitos necessários para diversas aplicações, em especial quando utilizadas baixas espessuras equivalentes de corte (h eq). Além disso, a técnica de MQL possui a vantagem de gerar um menor impacto ambiental em comparação com a lubrificação convencional, devido ao uso mínimo de fluido de corte cujo descarte é cada vez mais regulamentado e custoso.

Cerâmicas avançadas no processo de retificação cilíndrica externa de mergulho com rebolos diamantados com a técnica da mímima quantidade de lubrificação e refrigeração otimizada

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

Contribuição ao estudo da retificação abrasiva de materiais cerâmicos

Uma das principais limitações relacionadas ao processo de retificação de cerâmica é a confiabilidade do material devido aos defeitos introduzidos no processamento. A compreensão dos mecanismos envolvidos na remoção de material durante a retificação e a interação com os parâmetros de processo e microestrutura é fundamental para minimizar estes defeitos. A proposta desta revisão é apresentar os modelos de remoção de material e a forma como afetam as propriedades mecânicas da peça final.

Avaliação do desempenho de corte de diferentes grãos adiamantados

Por meio de um trabalho multidisciplinar entre Engenheiros e Dentistas, foram estudados oito diferentes tipos de grãos abrasivos de diamantes para a fabricação de pontas adiamantadas e/ou rebolos de pequeno diâmetro. Verificou-se qual o grão mais adequado para ser empregado nas pontas, as quais são utilizadas em equipamentos que possuem um pequeno torque disponível. Uma metodologia de experimentação para avaliação da capacidade de corte destas ferramentas foi desenvolvida, utilizando-se o vidro como material a ser desgastado. Como resultados, observou-se que a estrutura e a friabilidade do grão de diamante afetam diretamente a capacidade de corte das pontas adiamantadas. Desta forma, o melhor tipo de diamante foi aquele que apresentou, ao mesmo tempo, as melhores condições de remoção de material e o menor preço.

Comparação da influência entre tempos de polimerização em resinas compostas polimerizadas com LED e Luz Incandescente

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

Comparação dos valores de desgaste abrasivo e de microdureza de 13 resinas compostas usadas em odontologia através do método do disco retificado

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

Análise da influência dos diferentes tempos de polimerização por luz incandescente sobre a resistência ao desgaste abrasivo de resinas compostas

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

Quantitative characterization of multi-phase materials by digital image processing

An automatic image processing and analysis technique has been developed for quantitative characterization of multi-phase materials. For the development of this technique is used the Khoros system that offers the basic morphological tools and a flexible, visual programming language. These techniques are implemented in a highly user oriented image processing environment that allows the user to adapt each step of the processing to his special requirements.To illustrate the implementation and performance of this technique, images of two different materials are processed for microstructure characterization. The result is presented through the determination of volume fraction of the different phases or precipitates.

Wear resistance of experimental titanium alloys for dental applications

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

Fatigue Strength of X45CrSi93 stainless steel applied as internal combustion engine valves

Stainless steels are used to intake and exhaust valves production applied as internal combustion engines. In general valves are requested to support cyclic stresses applied due to opening and closing processes during the operation. The objective of this research is to study the influence on the axial fatigue strength of the resulting microstructure after heat treatment at the martensitic X45CrSi93 steel, combined with different surface treatments as hard chrome-plating, nitride and grinding. It was verified a significant increase on the fatigue strength of the martensitic steel after nitriding, compared with results from the chrome-plating specimens. A slight increase in the tensile strength was also noticed on nitrided parts as a consequence of a resistance increase due to nitrogen and carbon solid solution. (C) 2011 Published by Elsevier Ltd. Selection and peer-review under responsibility of ICM11