Search results for " fiber"
showing 10 items of 1776 documents
Fatigue resistance of fiber post and cement/build-up materials.
2004
Objectives:The purpose of this study was to evaluate the fatigue resistance to cycling loading of teeth restored with fiber post and different build-up systems. Methods: Forty human, sound single-rooted teeth were selected and stored in 0.02% thymol solution. The crowns were removed by cutting the teeth at the cement-enamel junction, thereafter endodontic treatment was performed using the vertical condensation technique. The roots were partially embedded in epoxy resin and randomly assigned to four groups. The specimens were restored with the same type of quartz fiber posts (DT Light Post, RTD, Grenoble, France), but different cements and build-up systems were used: 1)All-Bond2+C&B Cement+B…
Effect of endodontic treatment on fatigue resistance of fiber posts bonding
2003
Objectives: The aim of this study is to evaluate the effect of the endodontic treatment on the fatigue resistance of endodontic post adhesive interfaces. Materials and methods: 50 single-rooted human teeth have been severed at the cement-enamel junction and randomly assigned to 5 groups receiving different endodontic treatments as follows: 1) distilled water + gutta-percha (control); 2) NaOCl 5% + gutta-percha and Pulp Canal Sealer EWT (Kerr); 3) NaOCl 5% + gutta-percha and Top Seal (Dentsply-Maillefer); 4) NaOCl 5% and EDTA 10% (alternatively) + gutta-percha and Pulp Canal Sealer EWT; 5) NaOCl 5% and EDTA 10% (alternatively) + gutta-percha and Top Seal. Subsequently, Light-Post DT #2 quart…
On the mechanical behavior of BFRP to aluminum AA6086 mixed joints
2013
The aim of this work is to analyze the possibility to join aluminum alloy AA6086 and composite laminates reinforced with basalt fibers, an innovative material which use is growing in several applications as an alternative to glass fibers. To this goal, three joining techniques were investigated: mechanical by Self Piercing Riveting (in the next called SPR), adhesive by co-curing technique and mixed in which the joining techniques (i.e. adhesive and mechanical) were combined. Two manufacturing technologies (i.e. hand lay-up and vacuum bagging) were used both to produce composite substrates and to realize co-curing adhesion between the substrates to be joined. Mixed joints were realized by in…
On the response of flax fiber reinforced composites under salt-fog/dry conditions: Reversible and irreversible performances degradation
2022
Abstract Despite their scarce resistance to humid or wet conditions, natural fiber reinforced composites (NFRCs) seem to be able to partially recover their performances under discontinuous exposition to marine environment. To investigate this peculiarity, flax fiber reinforced composite was at first subjected to salt-fog spray condition at 35 °C for 15 and 30 days, respectively, and then stored in ‘‘dry” condition (i.e., 50% R.H. and 22 °C) between 0 and 21 days. The performances evolution was evaluated through flexural tests, water uptake and contact angle measurements. Moreover, the morphology of fractured mechanical samples was examined by using 3D optical microscope and scanning electro…
A taxonomic survey of lactic acid bacteria isolated from wheat (Triticum durum) kernels and non-conventional flours
2007
In order to explore the correspondence between raw material- and mature sourdough-lactic acid bacterial (LAB) communities, 59 Italian wheat (Triticum durum) grain samples, one bran and six non-conventional flour samples were analyzed through a culture-dependent approach. The highest cell count by an agar medium specific for LAB was 2.16 log CFU/g. From about 2300 presumptive LAB (Gram-positive and catalase-negative) colonies collected, a total of 356 isolates were subjected to identification by a genetic polyphasic strategy consisting of RAPD-PCR analysis, partial 16S rRNA gene sequencing, species-specific and multiplex PCRs. The isolates were recognized as 137 strains belonging to Aerococc…
All-Optical Fiber Hanbury Brown & Twiss Interferometer to study 1300 nm single photon emission of a metamorphic InAs Quantum Dot
2016
[EN] New optical fiber based spectroscopic tools open the possibility to develop more robust and efficient characterization experiments. Spectral filtering and light reflection have been used to produce compact and versatile fiber based optical cavities and sensors. Moreover, these technologies would be also suitable to study N-photon correlations, where high collection efficiency and frequency tunability is desirable. We demonstrated single photon emission of a single quantum dot emitting at 1300 nm, using a Fiber Bragg Grating for wavelength filtering and InGaAs Avalanche Photodiodes operated in Geiger mode for single photon detection. As we do not observe any significant fine structure s…
Polarization-domain-wall complexes in fiber lasers
2013
To study the possible build-up of polarization-domain-walls (PDWs) in fiber laser cavities, an erbium-doped fiber ring laser was used and a wide range of vector polarization dynamics that can be selected at a given pump power, by using the degrees of freedom of two intracavity polarization controllers (PC) was investigated. A simple theoretical model that explains polarization switching in fiber ring lasers featuring a normally dispersive cavity with a typical, moderate, level of birefringence is presented. Such polarization dynamics, based on a special class of polarization-domain-wall structures, agrees qualitatively well with experimental observations. The paper stresses on the complex a…
Hamiltonian tools for the analysis of optical polarization control
2011
Import JabRef; International audience; The study of the polarization dynamics of two counterpropagating beams in optical fibers has recently been the subject of a growing renewed interest, from both the theoretical and experimental points of view. This system exhibits a phenomenon of polarization attraction, which can be used to achieve a complete polarization of an initially unpolarized signal beam, almost without any loss of energy. Along the same way, an arbitrary polarization state of the signal beam can be controlled and converted into any other desired state of polarization, by adjusting the polarization state of the counterpropagating pump beam. These properties have been demonstrate…
Condition Monitoring Technologies for Synthetic Fiber Ropes - a Review
2020
This paper presents a review of different condition monitoring technologies for fiber ropes. Specifically, it presents an overview of the articles and patents on the subject, ranging from the early 70’s up until today with the state of the art. Experimental results are also included and discussed in a conditionmonitoring context,where failuremechanisms and changes in physical parameters give improved insight into the degradation process of fiber ropes. From this review, it is found that automatic width measurement has received surprisingly little attention, and might be a future direction for the development of a continuous condition monitoring system for synthetic fiber ropes.
A Strain Sensing Structural Health Monitoring System for Delaminated Composite Structures
2012
Structural Health Monitoring (SHM) for composite materials is becoming a primary task due to their extended use in safety critical applications. Different methods, based on the use of piezoelectric transducers as well as of fiber optics, has been successfully proposed to detect and monitor damage in composite structural components with particular attention focused on delamination cracks.In the present paper a Structural Health Monitoring model, based on the use of piezoelectric sensors, already proposed by the authors for isotropic damaged components, is extended to delaminated composite structures. The dynamic behavior of the host damaged structure and the bonded piezoelectric sensors is m…