S��ntese e caracteriza����o de novos materiais comp��sitos org��nicos/inorg��nicos, fotopolimeriz��veis, para uso em restaura����es odontol��gicas

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Comportamento t��rmico, mec��nico e morfol��gico dos comp��sitos de polietileno de alta densidade refor��ados com fibras de celulose do baga��o de cana de a��ucar

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Malha de nylon modificada para reforço estrutural de pr��teses odontol��gicas e processo de obten����o

The invention of a modified nylon mesh for structural reinforcement of dental prostheses is described, said modified nylon mesh comprising polyamide fibres and 0.3%-0.5% v/v silicon dioxide (SiO2), which enables chemical binding between the acrylic resin and the polyamide mesh in order to increase the strength of the resin/polyamide complex in said dental prosthesis.

An��lise te��rica e experimental do comportamento de vigas de alvenaria estrutural armada sujeitas �� flexão simples

P��s-gradua����o em Engenharia Civil - FEIS

Caracteriza����o mec��nica de uma porcelana de aplica����o convencional e uma prensada para recobrimento de infraestruturas de zirc��nia e o efeito do m��todo de resfriamento na resist��ncia �� flexão biaxial do conjunto zirc��nia/porcelana

P��s-gradua����o em Reabilita����o Oral - FOAR

Determina����o da resist��ncia �� flexão de ligas odontol��gicas, utilizadas em pr��tese parcial fixa e pr��tese sobre implante, soldadas por brasagem e a laser

P��s-gradua����o em Odontologia Restauradora - ICT

Processamento e caracteriza����o de comp��sito fibra de sisal/resina ep��xi via RTM

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Produ����o de nanocomp��sito utilizando diferentes fontes de celulose como reforço

P��s-gradua����o em Agronomia (Energia na Agricultura) - FCA

Influ��ncia da adi����o de nanopart��culas na estabilidade de cor, microdureza e resist��ncia �� flexão de resina espec��fica para confec����o de pr��teses oculares

Coordena����o de Aperfei��oamento de Pessoal de N��vel Superior (CAPES)

Estudo do conte��do de part��culas inorg��nicas, da contra����o de polimeriza����o e da resist��ncia �� flexão de materiais restauradores est��ticos diretos indicados para dentes posteriores

Recentemente, foram lan��ados no mercado odontol��gico novos materiais est��ticos para restaura����es diretas em dentes posteriores, aos quais s��o atribu��das propriedades mais adequadas para essa indica����o. Entretanto, as informa����es dispon��veis s��o ainda muito escassas, gerando d��vidas quanto �� sua real efic��cia, sobre quais as diferen��as de suas composi����es e propriedades f��sicas e mec��nicas em rela����o aos materiais at�� ent��o dispon��veis e se, de fato, apresentam melhor performance cl��nica. Em vista do exposto, nos propusemos a estudar contra����o de polimeriza����o, resist��ncia �� flexão e concentra����o de part��culas inorg��nicas, por massa e volume, de sete resinas compostas (Alert, Ariston, Solitaire, Definite, Filtek P60, Z-100 e Tetric Ceram). A contra����o de polimeriza����o foi medida nos materiais inseridos em um anel pl��stico, e o registro das altera����es, durante a polimeriza����o, foi feito por meio de instrumento eletr��nico de medida linear, que registra as altera����es dimensionais, com sensibilidade de 1 mm. A resist��ncia �� flexão foi medida na m��quina de ensaios mec��nicos MTS 810 e a confec����o dos corpos-de-prova e dos dispositivos para o ensaio foi orientada pela norma ISO no 4049:1988. A determina����o do conte��do de part��culas inorg��nicas por massa foi feita atrav��s da pesagem de uma por����o de resina composta polimerizada antes e ap��s a elimina����o da fase org��nica em forno, �� temperatura de 700oC. O porcentual volum��trico de part��culas inorg��nicas foi calculado com base no Princ��pio de Arquimedes. Foi determinado o volume da resina composta polimerizada, antes e ap��s a elimina����o da fase org��nica, pela diferen��a da massa do material pesado ao ar e imerso em ��gua. Os dados de conte��do de part��culas inorg��nicas por massa e por volume, de contra����o de polimeriza����o e resist��ncia �� flexão foram submetidos...(Resumo completo, clicar acesso eletr��nico abaixo)

Utiliza����o de reforço geossint��tico em vias ferrovi��rias

This report analyses the use of geosynthetics in railways for subgrade reinforcement and separation of the track layers. Cases of instrumented test sections were studied. These test sections were located in Australia (with geocomposite applications), Brazil (with geotextile and geodrid applications) and China (with geotextile and geodrid applications). Railway design methods using geosynthetics applications were analyzed as well. Based on a studied case for implementation of geosynthetics in a German railway, a railway track was simulated with and without the use of geosynthetics, respectively on PLAXIS v.8 and FERROVIA 3.0 softwares. The performance benefits of the geosynthetics applications in railways were, therefore, confirmed, based on the simulation results

Estudo comparativo de dois tipos de pain��is de MDP: com adi����o de papel impregnado e l��minas de bambu

This work is the production of two types of particle boards reconstructed MDP (Medium Density Particleboard), the first with the addition, in the inner layer of particles of impregnated paper, the ratios of 0%, 1%, 5% and 20 %. In the second type of panel MDP was inserted with blades of bamboo species Dendrocalumus giganteus as coatings and structural reinforcement. The MDP panel, used as a basis for both cases has the composition of three layers, two external particles with smaller particle size and an inner layer composed of particles of larger particle sizes. Assays were performed based on physical and mechanical NBR 14.810/2006 for the determination of the board density, thickness swelling, water absorption, moisture content, bending, tension parallel and perpendicular, and testing of particle sizes of the particles did not exists in standard references. The results were analyzed and compared the results of the commercial boards made from 100% eucalyptus, based on the limits specified by the ABNT NBR 14.810/2006. The values of the tests showed similar results indicating normative specifications in a positive way, the possibility of production of MDP with the use of waste paper impregnated. As for the panel with bamboo blades, the tests showed a mechanical performance far superior to MDP market, explaining the study and possible implementation of the bamboo for use where the MDP will suffer greater mechanical stress, such as doors, tops and benches tables

Processamento do comp��sito de fibra de capim-sap�� / ep��xi e avalia����o da resist��ncia �� flexão ���t��� de Student

In recent years a great worldwide interest has arisen for the development of new technologies that enable the use of products with less environmental impact. The replacement of synthetic fiber plants is a possibility very important because this fiber is renewable, biodegradable and few cost and cause less environmental impact. Given the above, this work proposes to develop polymeric composites of epoxy resin and study the behavior of these materials. Both, the epoxy resin used as matrix in the manufacture of sapegrass fiber composite, as tree composites formed by: epoxy/unidirectional sapegrass long fiber, 75% epoxy/25% short fiber, by volume, and 80% epoxy/20% short fiber, by volume, were characterized by bending, and the composites produced with short fibers random were inspected by Optical Microscopy and Acoustics Inspection (C-Scan). For the analysis of the sapegrass fiber morphology, composites 75% epoxy/25% short fiber (sheet chopped) and 80% epoxy/20% short fiber images were obtained by optical microscope and the adhesion between polymer/fiber was visualized. As results, the flexural strength of composites epoxy/unidirectional long fibers, 75% epoxy/25% short fiber and 80% epoxy/20% short fiber were 70.36 MPa, 21.26 MPa, 25.07 MPa, respectively. Being that composite showed that the best results was made up of long fibers, because it had a value of higher flexural strength than other composites analyzed

Reciclagem de poliestireno expandido: comp��sito com fibras de sisal para confec����o de placas de circuito impresso

In this work polystyrene composites reinforced with recycled sisal fibers were processed, in order to apply in the manufacture of printed circuit boards. A thermoplastic matrix of recycled polystyrene was used, this material came from waste expanded polystyrene (EPS) used in appliance's packages. Composites were prepared with 15% and 25% of sisal fibers. To obtain the composites, wasted EPS and natural sisal fibers were chosen, to encourage recycling and reuse of household waste and also the use of renewable resources. The composites were analyzed by standard tensile and flexural test, in order to verify the mechanical properties of the material. The characterization of the composite was done by scanning electron microscopy (SEM) , thermogravimetry (TGA / DTG) , differential scanning calorimetry (DSC) and dielectric analysis . The analysis of the results showed that the percentage of fibers in the composite influences directly the thermal and mechanical properties. Plates with a lower percentage of fibers showed superior properties at a higher percentage. The composite material obtained is easy to process and it's use is feasible for the confection of printed circuit boards, considering it's mechanical, thermal and insulative properties

Prepara����o e caracteriza����o da casca de banana prata particulada para aplica����o com reforço em comp��sito de matriz de PEAD

The waste, exaggerated and incorrect disposal of biomass are common practices in modern times where everything is disposable. However the growing concern with the nature and the environment compel man to give nobler destinations for these products through sustainability and recycling of waste. Banana peel is a residual biomass, which is not consumed. It generates tons of waste per week in S��o Paulo city. This trash is disposed in dumps and landfills, which could be reduced by using it as reinforcement in natural composites. The high density polyethylene (HDPE) is a polymer derived from the ethylene polymerization and is easily recycled. Which makes it a sustainable material. In the present work characteristics of the natural composite composed with banana peel and high-density polyethylene were studied. It was noted that removing the lignin present in the banana peel, the fiber introduces a significant improvement in thermal resistance. The preparation of composite was made with a ratio of 5% and 10% of reinforcement in comparison with polymeric matrix mass. Composites were thermally, mechanically and microscopically characterized. The addition of fiber in the polymer increased the mechanical strength of the composite. The fiber surface treatment with distilled water removed the amorphous material present in the fibers, improving significantly thermal stability and increasing crystallinity of the celullose. The addition of 5% fiber in mass to the polymer increased significantly the tensile strength and elasticity modulus for the composite. With 10% of fiber addiction there were also an improvement when compared with pure HDPE, but when compared with 5% composite the mechanical properties are slightly lower. This may be due to the fiber particle size, which are small and eventually become a hub of tension ... (Complete abstract click electronic access below)