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Congresos, Seminarios y Cursos

Mechanical behavior of silver alloys used as cast post and core in maxillary incisors

This experimental "in vitro" investigation is mainly concerned with the mechanical behavior of twenty plastic analogous simulating endodonticaly treated maxillary central incisor roots, divided in two groups, which were restored with: (i) silver (10 specimens, Ag - 80%); and (ii) silver - palladium (10 specimens, Ag -…

Rheological Measurement of Building Materials

Microstructure of a cement matrix composite reinforced with polypropylene fibers

The present investigation deals with the microstructural characterization of a composite material, which is comprised of polypropylene fibers in an cement matrix, by means of environmental scanning electron microscopy (ESEM) and field emission scanning electron microscopy (FESEM). The microstructure of the different p…

International Seminar on Paste and Thickened Tailings

Editorial

Evaluation of the adhesion strength of diamond films brazed on K-10 type hard metal

The coating of cutting tools with diamond films considerably increases the tool performance due to the combination of the unique tribological properties of diamond with the bulk properties of the substrate (toughness). The tool performance, however, is strongly related to the adhesion strength between the film and the…

Calcium phosphate formation on alkali-treated titanium alloy and stainless steel

Alternatives to the plasma spraying method have been developed to obtain calcium phosphate coatings, like the biomimetic method. This process is a physicochemical method in which a substrate is soaked in a solution that simulates the physiological conditions, for a period of time enough to form a desirable layer of th…

Characterization of the Linear Viscoelastic Region in Suspensions of Zirconium Oxide: Cohesive Energy Obtained From the Critical Parameters

Abstract The linear viscoelastic regions (L.V.R.) of suspensions of zirconium oxide particles were determined and characterized through the so-called "critical parameters". These are the values of shear-stress and strain at the crossover between the linear and the non-linear viscoelastic responses. From these magnitud…

Demineralization around restorations with different restorative materials containing fluoride

The aim of this study was to evaluate in vitro the demineralization on tooth/restoration interface of eight restorative materials after demineralization/remineralization cycling. Eighty class V cavities were prepared with margins at enamel and dentin/cementum, and were restored with Fuji II LC, Fuji IX, Ketac-fil, Ket…

Comparison of the compressive strength of impregnated and nonimpregnated eucalyptus subjected to two different pressures and impregnation times

The durability of wood is affected by several factors. For this reason, much research has been done on a variety of chemical compounds for impregnating wood, aimed at preserving it while simultaneously improving its properties. Recent studies of the properties of impregnated wood have demonstrated the possibility of s…

Dynamic Rheological Properties of Concentrated Chitosan Soltions

Abstract A detailed analysis of the dynamic flow properties of chitosan in solution at different temperatures (25 - 45°C), chitosan concentration (0.5% - 2.0%), solvent type (acetic, lactic, and hydrochloric acid), and ionic strength (0 and 0.2M NaCl) has been undertaken. The storage modulus, G’, loss modulus, G’’ and…

Viscosity

Evaluation of the biocompatibility of a new biomembrane

Biocompatibility has been considered one of the most important items to validate a biomaterial for its application in human organisms. The present work evaluates the biocompatibility of a new biomembrane using in vivo assay in different animal species. The experiments to evaluate the cellular reaction were carried out…

Editorial

Mathematical modeling and experimental analysis of the hardened zone in laser treatment of a 1045 AISI steel

The aim of this work is to develop a mathematical model to predict the depth of laser treated zone in the LTH process. The Fourier equation of heat conduction is solved by using the Finite Difference Method in cylindrical coordinates in order to study the temperature distribution produced in a workpiece and hence to o…

Synthesis, characterization and determination of the metal ions adsorption capacity of cellulose modified with p-aminobenzoic groups

This paper describes the synthesis and characterization of p-aminobenzoic modified cellulose (Cell-PAB), as well as the separation and preconcentration of Cd(II), Cu(II), Ni(II), Pb(II) and Zn(II) ions from an aqueous medium using a Cell-PAB bath and the column technique. The quantity of p-aminobenzoic groups attached…

Synthesis and Characterization of Electrochromic Polyamides with Well‐Defined Molecular Structures and Redox Properties

Abstract In this paper we report the synthesis and characterization of a series of electrochromic polyamides (alternating copolymers). The synthesis proceeds via the condensation polymerization between amine‐capped oligoaniline and acyl chlorides such as isophthaloyl dichloride, terephthaloyl chloride, azelaoyl chlori…

Effect of porosity on the tensile properties of low ductility aluminum alloys

The literature contains reports of several studies correlating the porosity and mechanical properties of aluminum alloys. Most of these studies determine this correlation based on the parameter of global volumetric porosity. These reports, however, fail to separate the effects of microstructural features and porosity…

High Curie temperatures in ferromagnetic Cr-doped AlN thin films

Al 1−x Cr x N thin films with 0.02⩽x⩽0.1 were deposited by reactive co-sputtering onto c-plane (001) sapphire. Room-temperature ferromagnetism with a coercive field of 85 Oe was observed in samples with chromium contents as low as x=0.027 (2.7%). With increasing Cr content the mean magnetic moment is strongly suppress…