Search results for "Composite"

STRONTIUM CONCENTRATION DEPENDENCE OF SELECTED STRUCTURAL AND MECHANICAL PROPERTIES OF POLYCRYSTALLINE Ba1−XSrXTiO3

2009

ABSTRACT Microstructure and material constants such as Young modulus E, shear modulus G, Poisson ratioν of polycrystalline ferroelectric materials Ba1-xSrxTiO3 for 0≤x≤0.4 were investigated to determine their dependence on strontium concentration. The performed investigations showed that the material is chemically homogeneous. It was found that the strontium concentration had no significant influence on the grain size. The highest value of Young's modulus is observed for Ba0.6Sr0.4TiO3 sample. The performed investigations of mechanical properties made it possible to evaluate the usability of this material for manufacturing transducers and sensors which could work under load.

Erratum to “Cerium effect on the phase structure, phase stability and redox properties of Ce-doped strontium ferrates”

2008

Systematic comparison of Artificial Neural Networks for a SHM procedure applied to Composite Structure

2014

The problems related to damage detection represents a primary concern, particularly in the framework of composite structure. In fact, for this kind of structures barely visible damage can occur. Moreover, one of the major in-service damage of composite aircraft strcutures is represented by disbonds between the stiffeners and the skin undergoing dynamic or post-buckling loads. The effective implementation of a SHM system relies on the synthesis of non-destructive technique (NDT), fracture mechanics, sensors technology, data manipulation and signal processing, and it can receive a great improvement through the use of an Artificial Neural Networks. Different architectures of Artificial Neural …

Optimization of laminated composites plates using glowworm algorithm

2010

Dielectric and Elastic Parameters of LixNa1-xTa0.1Nb0.9O3 Ferroelectric Solid Solution Ceramics

2011

Results of the studies of electric and elastic parameters as functions of concentration in ferroelectric LiхNa1-хTa0.1Nb0.9O3 (x = 0–0.16) solid solutions and comparative studies of the elastic properties by acoustic and contact probe techniques are reported. The electric and elastic properties of LiхNa1-хTa0.1Nb0.9O3 solid solutions are shown to be rather sensitive to structural distortion at concentration-induced structural phase transitions. The values of elastic modules obtained from acoustic measurements are found to be in good agreement with those obtained by contact probe techniques.

Materials Communicating with the BIM: Aims and First Results of the McBIM Project

2019

This paper introduces McBIM, a French national research project working on on-line monitoring on concrete structure. This project gathers 3 french laboratories (the CRAN, LAAS and LIB) associated with one company (360SmartConnect/FINAO SAS) that are working together from 2018 to 2021. It proposes 1) to design a “communicating concrete”, made of concrete equipped with embedded low-energy wireless microsensor network, able to manage and exchange data using BIM standards, and 2) to demonstrate the usefulness of this approach across several building lifecycle phases, namely the manufacturing, construction and exploitation phases for structural health monitoring. The paper will first start by in…

Effect of proanthocyanidin mediated immediate and delayed dentin sealing on the strength of premolars restored with composite resin inlay.

2019

Background Immediate dentin sealing (IDS) with proanthocyanidin (PA) could be used before cementation with a self-adhesive (SA) cement. The aim of this study was to assess the effect of PA treatment on acid-etched dentin before adhesive application, in IDS and delayed dentin sealing (DDS), on the strengthening property of SA-cemented composite resin inlay in premolars. Material and Methods Eighty-four maxillary premolars were divided into 7 groups (n=12): 1) (Intact) Sound teeth served as controls; groups 2-7) After cavity preparation and fabrication of composite resin inlay, temporary inlays were made and cemented. After one week, the inlays were removed and composite inlays were luted wit…

Effect of composite/amalgam thickness on fracture resistance of maxillary premolar teeth, restored with combined amalgam-composite restorations

2016

Background: Combined amalgam-composite restorations have been used through many years to benefit from the advantages of both dental amalgam and composite resin. Two variations have been mentioned for this technique, this study investigated the fracture resistance of maxillary premolar teeth with extended mesio-occluso-distal (MOD) cavities, restored with the two variations of combined amalgam-composite restorations. Material and Methods: Sixty intact extracted premolar teeth were randomly divided into 6 groups (G1-G6) of 10 teeth. G1; consisted of intact teeth and G2; consisted of teeth with MOD preparations were assigned as the positive and negative control groups respectively. Other exper…

Reparability of giomer using different mechanical surface treatments

2016

Background In the repair process achieving high bond strength between the new and old resin based materials is necessary for clinical longevity. This study compared the effect of three different mechanical surface treatments (air abrasion, Nd:YAG laser and diamond bur) on the repair bond strength of giomer. Material and Methods In this in vitrostudy, 125 cylindrical giomer samples were used. The giomer samples were randomly assigned to 5 groups (n=25). In group 1, the samples did not undergo any surface treatment. In groups 2 to 4, the samples underwent surface treatments with air abrasion, Nd:YAG laser and a diamond bur. The samples in group 5 were prepared to measure giomer cohesive stren…

Sulphate-reducing bacteria in paper machine waters and in suction roll perforations

1978

To define some aspects of the biological corrosion sulphate-reducing bacteria were studied in paper machine waters and in plugged perforations of a suction roll. The desulphuricants were most active on passive fiber recipients. Most bacteria found in fiber plugs taken from the perforations of suction rolls belonged to the genus Desulfovibrio. Desulphuricants were found mainly at the outer ends of plugged perforations, where corrosion of the roll metal is most evident.