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Nondestructive Evaluation of RC Structures Strengthened with FRP Laminates Containing Near-Surface Defects in the form of Delaminations

Congress and Seminars

A Variational Formulation and Analysis of Polar Orthotropic Circular Plates Using an Energy Principle, Part I: Thin Plates

The Effect of Varying the In-plane Loads and Stacking Sequence on the Vibration Analysis of Composite Stiffened Plates

Antimicrobial Polymeric Materials; Cellulose and m- Aramid Composite Fibers

Cellulose and m-aramid were dissolved in an ionic liquid, and dry-jet wet spinning was employed to prepare composite fibers which could be rendered antimicrobial through exposure to chlorine bleach. The small domains of the m-aramid allowed a much higher accessibility and degree of chlorination than has been reported…

Editorial

Conductive diamond electrodes for water purification

Nowadays, synthetic diamond has been studied for its application in wastewater treatment, electroanalysis, organic synthesis and sensor areas; however, its use in the water disinfection/purification is its most relevant application. The new electrochemistry applications of diamond electrodes open new perspectives for…

Improving the prediction of strength and rigidity of structural timber by combining ultrasound techniques with visual grading parameters

The present study explores the possibility of using longitudinal ultrasound transmission to evaluate the bending strength and modulus of elasticity in structural timber made from the two species most commonly found in Spanish construction and rehabilitation works: Scots pine (Pinus sylvestris L.) and Laricio pine (Pin…

Optimization of compressive strength in admixture-reinforced cement-based grouts

The Taguchi method was used in this study to optimize the unconfined (7-, 14- and 28-day) compressive strength of cement-based grouts with bentonite, fly ash and silica fume admixtures. The experiments were designed using an L16 orthogonal array in which the three factors considered were bentonite (0%, 0.5%, 1.0% and…

Numerical Methods for Non-Newtonian Flows – XVth IWNMNNF 2007

Error Introduced by a Popular Method of Processing Parallel-Disk Viscometry Data

The assumptions implicit in the simplified expressions used to convert the torque-rotational speed data of parallel-disk viscometry into rim shear rate and rim shear stress are identified. The rim shear stress generated by the simplified expression is compared against the actual rim shear stress. The error involved is…

Genetic Programming Approach for Flow of Steady State Fluid Between Two Eccentric Spheres

Genetic Programming (GP) is used to estimate the functions that describe the torque and the force acting on the external sphere due to steady state motion of viscoelastic fluid between two eccentric spheres. The GP has been running based on experimental data of the torque at different eccentricities to produce torque…

Modified method for obtaining the critical cooling rate for vitrification of polymers

Due to the relevance of the critical cooling rate, Rc, for glasses, Barandiarán and Colmenero (BC) developed a method for calculating Rc as a function of the crystallization temperature on cooling obtained from thermal analysis. The critical cooling rate is obtained by the extrapolation method to conditions of infinit…

Effects of State Change of Liquid Crystalline Polymer on Dynamic Visco-Elasticity of its Blends with Polyethylene-Terephthalate

The dynamic viscoelastic properties of liquid crystalline polymer (LCP) and polyethylene terephthalate (PET) blends were studied at two different temperatures: 265°C at which LCP was in solid state and 285°C at which LCP was in molten state. The PET was in molten state at both the temperatures. The storage modulus, G’…

Passivation of duplex stainless steel in solutions simulating chloride-contaminated concrete

Most studies published to date on the corrosion behaviour of stainless reinforcing steel are based on austenitic steel. The market presence of corrugated duplex steel is growing, however. The present study compared passivity in 2205 type duplex and 304 type austenitic stainless steel. Polarization tests in chloride-co…

Alteration of granite stone used in building construction

The article contains a synthesis of the different factors involved in the alteration of granite ashlars or cladding used in building construction. Emphasis is placed on the – primarily fissure-like – anisotropies often present in granite, which are usually related to the structural conditions of the quarry where it is…

Polyaniline synthesized with functionalized sulfonic acids for blends manufacture

Polyaniline (PAni), an electronic conductive polymer, has poor mechanical properties, such as low tensile, compressive and flexural strength that render PAni a non-ideal material to be processed for practical applications. Desired properties of polyaniline can be enhanced by mixing it with a polymer that has good mech…

Comparative investigation of the adhesion of Ce conversion layers and silane layers to a AA 2024-T3 substrate through mechanical and electrochemical tests

Cerium conversion layers and silane films are among the potential substitutes for the carcinogenic chromate conversion layers used to protect high-strength Al alloys. In the present work the adhesion of a cerium conversion layer and of a silane film to an aluminium alloy (AA) 2024-T3 substrate was investigated using m…

PtRu/C electrocatalysts prepared using electron beam irradiation

PtRu/C electrocatalysts (carbon-supported PtRu nanoparticles) were prepared submitting water/ethylene glycol mixtures containing Pt(IV) and Ru(III) ions and the carbon support to electron beam irradiation. The electrocatalysts were characterized by energy dispersive X ray analysis (EDX), X ray diffraction (XRD) and cy…

Low-cost processing technology for the synthesis of calcium phosphates/collagen biocomposites for potential bone tissue engineering applications

In the present study two novel composites of Calcium phosphates (CaP) and Collagen (COL) were synthesized, hydroxyapatite/Collagen (HA/COL) and hydroxyapatite-btricalcium phosphate/COL (HAbTCP/COL). Collagen was extracted from bovine pericardium submitted to enzymatic digestion and purification by ion-exchange chromat…