Resin-based composite reinforced sealant

Purpose: To describe and picture a technique for using a resin-bonded sealant reinforced by inclusion of resin-based composite, before polymerization. Method: Using an extracted mandibular molar, embedded in plaster and isolated with a rubber dam, a step-by-step depiction of the technique is shown. Results: A picture of a six-year-old sealant in a first permanent molar, still in perfect condition, is shown. Conclusion: This technique offers a reliable method for treating pits and fissures.

An ultra stable glass system for optical fiber devices

In this paper a modified chalcogenide glass was studied by X-ray powder diffraction, differential thermal analysis, infrared and Raman scattering spectroscopies. The study of this new matrix opens new perspectives to fabricate Pr3+-doped fibers to operate as an optical amplifier in the 1.3 mum telecommunications window. The Pr3+-doped 70Ga(2)S(3)-30La(2)S(3) glass was modified through the substitution of La2S3 by La2O3, which improves the thermal stability of these glasses without any modification of phonon energy. The possibility to pull a fiber from this glass system without any devitrification is easily achieved.

Non-linear boundary element analysis of floor slabs reinforced with rectangular beams

In this work, a numerical model to perform non-linear analysis of building floor structures is proposed. The presented model is derived from the Kirchhoff-s plate bending formulation of the boundary element method (BENI) for zoned domains, in which the plate stiffness is modified by the presence of membrane effects. In this model, no approximation of the generalized forces along the interface is required and the compatibility and equilibrium conditions along interfaces are imposed at the integral equation level. In order to reduce the number of degrees of freedom, the Navier Bernoulli hypothesis is assumed to simplify the strain field for the thin sub-regions (rectangular beams). The non-linear formulation is obtained from the linear formulation by incorporating initial internal force fields, which are approximated by using the well-known cell sub-division. Then, the non-linear solution of algebraic equations is obtained by using the concept of the consistent tangent operator. The Von Mises criterion is adopted to govern the elasto-plastic material behaviour checked at points along the plate thickness and along the rectangular beam element axes. The numerical representations are accurately obtained by either computing analytically the element integrals or performing the numerical integration accurately using an appropriate sub-elementation scheme. (C) 2007 Elsevier Ltd. All rights reserved.

Food and dietary fiber intake by children with or without constipation. Assessment according to the food guide pyramid and the American Health Foundation (AHF)

We studied the ingestion of 54 children with functional constipation (CC) and 41 without (Control), according to the Food Pyramid. A food frequency questionnaire was used, analyzing fruits with or without peel/bagasse, grains whole or refined, and beans separately. Total subjects and 2-6y CC ingested less DF (g/day) than Control (p < 0.05). The majority had high n degrees of dairy and of the meat group servings, but most groups/subgroups did not meet recommendation for fruit and vegetable. A greater proportion of fruit with peel/bagasse in Control than in CC was almost the only difference for 6-12y. There was a discrepancy between the high percentage of children with DF above AHF recommendation and the high percentage of children who did not meet Pyramid recommendations.

Influence of Environmental Conditioning on the Shear Behavior of Poly(phenylene sulfide)/Glass Fiber Composites

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Hygrothermal Aging Effect on Fatigue Behavior of GLARE

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

Employing 2D Projections for Fast Visual Exploration of Large Fiber Tracking Data

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

An In Vitro Comparison of Different Cementation Strategies on the Pull-out Strength of a Glass Fiber Post

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Processing and mechanical characterization of titanium-graphite hybrid laminates

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

A disposable chitosan-modified carbon fiber electrode for dengue virus envelope protein detection

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Effect of surface treatment on fatigue behavior of metal/carbon fiber laminates

The tension-tension fatigue behavior of metal/fiber laminates (MFLs) has been investigated. These MFLs were produced with carbon fiber and by treating the aluminum foil to promote adhesion bonding by two methods: sulfuric-boric-oxalic acid anodization (SBOA) and chromic acid anodization (CAA). The surface treatments were evaluated by scanning electron microscopy (SEM) techniques and roughness measurements. It was observed that MFL specimens produced with SBOA treatments presents comparable mechanical results when compared with MFLs produced with CAA treatment. Microstructural observations of the fracture surfaces by SEM show hackle formation is the predominant damage mechanism.

Alternatives Panels from Waste Plastics Reinforced With Fibers of Pupunha Palm for Use in Civil Construction and Furniture Industry

In order to cooperate in minimizing the problems of the current and growing volume of waste, this work aims at the production of panels made from industrial waste -thermoplastic (Polypropylene - PP; Polyethylene - PE and Acrylonitrile Butadiene Styrene - ABS) reinforced with agro-industrial waste - pupunha palm waste (shells and sheaths). The properties of the panels were evaluated: density, thickness swelling, water absorption and moisture content. It was used the ASTM D1037; EN 317; and ANSI A208.1 standards regarding particle boards. The best results in physical tests were treatments 1 (100% waste plastic), 6 (60% plastic waste and 40% waste of pupunha) and 7 (70% waste plastic and 30% waste of pupunha). The best results in the mechanical tests were treatments 3 (30% de residuos plasticos e 70% de residuos da pupunha), 4 (40% de residuos plasticos c 60% de residuos da pupunha) and 5 (50% de residuos plasticos e 50% de residuos da pupunha). For mechanical tests it was concluded that the results of modulus of rupture and of modulus of elasticity the best treatments were those with more fibers. In the tensile tests perpendicular to the surface, it is clear that using more waste plastics leads to the best results. It was concluded that the waste can be used as raw material for the production of alternative materials mainly in civil construction and furniture industries, and it can be employed in urban or rural environment, given the concept of eco-efficient products.