Search results for "Durability."
showing 10 items of 105 documents
Effect of thermocycling and surface treatment on repair bond strength of composite.
2017
BACKGROUND Repair of composite restorations is a conservative method that can increase the longevity and durability of restorations while preserving the tooth structure. Achieving a suitable bond between the old and new composite is difficult. To overcome this problem, some methods have been recommended to increase the repair bond strength of composite.This study aimed to assess the effect of aging by thermocycling (5,000 and 10,000 cycles) and mechanical surface treatments (Er,Cr:YSGG laser and bur) on repair shear bond strength of composite resin. MATERIAL AND METHODS Totally, 120 composite blocks measuring 6x4x4 mm were fabricated of Filtek Z250 composite and were randomly divided into t…
Closed-loop recycling. A case study of films for greenhouses
2010
Abstract The degradation undergone by plastic films used for greenhouse coverage is the main cause of the worsening of the processability, of the mechanical properties and of the durability of secondary materials obtained by their recycling. This means that this secondary material cannot be processed to produce films for the same applications (closed-loop recycling). In this work different strategies are proposed to improve the processability, some mechanical properties and the resistance to photo-oxidation of these secondary materials. In particular, homopolymer blends or multilayer films where the secondary material is used in combination with virgin polymer give the best results.
A Systematic Review of the Hydrological, Environmental and Durability Performance of Permeable Pavement Systems
2021
Due to urbanization, large portions of vegetated territory have been replaced by waterproof surfaces. The consequences are greater outflows, lower infiltration, and lower evapotranspiration. Pavement systems made with permeable surfaces allow the infiltration of water, ensuring reduction of runoff volume. In this paper, the methods of analysis of the hydrological and environmental performance of the pavement systems are reviewed in the context of urban drainage and regarding their durability. The purpose is to present an overview of the studies published during the last decade in the field. The Pubmed and Web Science Core Collection electronic databases were used to conduct the scientific l…
On the physico-chemical evolution of low-pH and CEM I cement pastes interacting with Callovo-Oxfordian pore water under its in situ CO2 partial press…
2014
International audience; Abstract Within the framework of geological repositories for radioactive waste, structural concretes must be adapted to the underground chemical conditions. CEM I cement-based materials are characterised by high pH that may produce an alkaline plume in the near-field of the repository. In order to avoid this problem, low-pH cements have been designed. This study compares the physico-chemical behaviour of a low-pH material with a CEM I cement paste, both being subjected to leaching by an aqueous solution. An original experimental setup was designed to reproduce the underground conditions using a specific CO2 regulation device. Under these conditions, the low-pH materi…
The Durability of Composite Wood-Steel Systems
2010
Nell’ambito della valutazione e del controllo della qualità tecnologica in edilizia, la conoscenza del comportamento nel tempo dei prodotti e componenti complessi per l’edilizia, risulta aspetto fondamentale, in particolare per quei prodotti tecnologicamente “innovativi” per i quali la normativa non prevede ancora prove specifiche per valutarne la durabilità. In particolare, oggi risulta sempre più diffuso l’impiego di sistemi assemblati o con connessioni tra materiali di diversa natura, tra cui i sistemi legno-acciaio, ottenuti rinforzando le travi in legno lamellare con piastre in acciaio forate, incollati mediante una resina epossidica bicomponente. Tali sistemi, che sono stati già ogget…
Durability of advanced nanocomposites based on polyethylene oxide and nanodiamonds
2016
Nanodiamonds nanoparticles (NDs) are amongst the most promising materials for multifunctional nanocomposites for various applications
Preparation and characterization of continuous fly ash derived glass fibers with improved tensile strength
2018
Abstract The coal-based energy production in China generates more than 600 million tons of coal fly ash (CFA) each year, which drives us searching for new methods for recycling CFA. In this work, continuous glass fibers with a range of CFA (25–45%) were successfully prepared without showing any sign of fiber crystallization. The measured fiber tensile strength was found to increase with CFA proportionally. The fiber derived from 45% CFA exhibited the best tensile strength (higher than the E glass fiber prepared/tested under the same conditions) and good chemical stability (98% mass retention in the acid corrosion test). Our study shows a feasibility of making continuous CFA derived glass fi…
Effectiveness and Safety of Ustekinumab in Ulcerative Colitis: Real-world Evidence from the ENEIDA Registry
2021
Abstract Background and Aims The development programm UNIFI has shown promising results of ustekinumab in ulcerative colitis [UC] treatment which should be confirmed in clinical practice. We aimed to evaluate the durability, effectiveness, and safety of ustekinumab in UC in real life. Methods Patients included in the prospectively maintained ENEIDA registry, who received at least one intravenous dose of ustekinumab due to active UC [Partial Mayo Score [PMS]>2], were included. Clinical activity and effectiveness were defined based on PMS. Short-term response was assessed at Week 16. Results A total of 95 patients were included. At Week 16, 53% of patients had response [including 35% o…
Durability of flax-basalt hybrid composites for marine applications
2015
The aim of the present work is to evaluate the influence of external layers of mat basalt on the durability behaviour and performances of flax/epoxy laminates. To this scope, long-term aging tests were performed to evaluate the durability of the two different laminates in critical environmental conditions. In particular, Flax composites were constituted by ten layers of bidirectional flax fabric whereas hybrid laminates (i.e. Flax-Basalt) were produced by replacing four external layers of bidirectional flax with four layers of basalt mat. Both laminates had a total average thickness equal to 3 mm. The samples were exposed to critical environmental conditions following the ASTM B 117 standar…
Comportement en fatigue thermomécanique à haute température d’un système barrière thermique texturé par laser
2020
In service life of Thermal Barrier Coating (TBC) systems for blade applications can be limited by the top-coat (TC) spallation under thermo-mechanical fatigue (TMF) loadings. To improve its TMF life, laser texturing at the bond-coat/top coat interface in the CMSX-4 Plus / γ-γ’ BC/ EB-PVD TC system has been investigated.Thanks to the study of the laser-matter interaction, it seems that the different Ni-based single crystal superalloys have similar laser ablation behaviors and they present almost no sub-surface damage after ablation. Nevertheless, the formation of melted matter near created cavities, possibly recrystallized, is often observed.Different patterns (holes, lines, grids) have been…