Search results for "durability."
showing 10 items of 105 documents
Impact of Asphalt Mixture Specification Limits: A Theoretical Analysis
2020
AbstractSpecifications limits and tolerances are crucial in the relationships among contractor, road agency, and citizens because they influence profits, acceptance procedures, and pavement durabil...
Experimental Study on the Performance of Timber Frame Wall Panels in Mediterranean Construction
2018
Only recently, the use of wooden buildings is spreading in the central and southern parts of the Italy due to national and EU policies on eco-sustainability and energy saving. Knowledge of the durability of the building envelope elements, generally made with dry assembled stratified systems, is still insufficient. The paper presents the first results of a durability evaluation of multilayer timber panel applied to Platform Frame System buildings, focusing on the variation of energy performance over time. The case study describes the construction of two single-family houses in the municipality of San Cataldo (Sicily, Italy). The used timber multilayer panel presents a stratigraphy suitable f…
Effect of Chlorhexidine on durability of two self-etch adhesive systems
2020
Background Despite of the rapid development in the field of dental adhesives, the issue of reduction in dentin bond durability has still not been resolved. The activity of dentinal endogenous enzymes such as MMPs is one of the most important causes of failure in resin composite restorations. The aim of this study was to investigate the influence of Chlorhexidine on micro-tensile bond strength of two types of commercially available self-etch adhesives. Material and Methods Twenty four sound and freshly extracted molars were selected. Four standardized flat mid-coronal dentinal disks were prepared from each tooth. The specimens were randomly assigned to 6 groups (n=16). Groups A(control group…
Effect of silver diamine fluoride on the bond durability of normal and carious dentin
2019
Background Silver diamine fluoride (SDF) has attracted attention because of its clinical success in arresting dentin caries. It has been shown that it can inhibit matrix metalloproteinases and cysteine cathepsins. These two properties might be beneficial in bonding to caries-affected dentin (CAD). Therefore, the present study aimed to investigate the effect of SDF on the durability and bond strength to the CAD. Material and Methods Forty-eight third molars with occlusal caries were used. The roots were cut, and the occlusal enamel was removed. The CAD area surrounded by the normal dentin (ND) was exposed. All the specimens were bonded with an etch-and-rinse adhesive, but half of them were t…
Effect of chlorhexidine on the durability of a new universal adhesive system
2018
Background The effect of chlorhexidine on bond durability of universal adhesives is not clear. The aim of this study was to evaluate the effect of chlorhexidine on 6-month water storage bond strength of adhesive systems. Material and Methods 72 freshly sound human extracted molars were selected. In each tooth both buccal and lingual sides were prepared by bur to reach superficial dentin and randomly divided into 6 groups and 12 sub-groups and bonded with Scotchbond Universal (SBU) or Scotchbond Multi-purpose (SBMP) with/without chlorhexidine (CHX) usage. Group 1: SBU, group2: SBU+CHX, group3: Etch+SBU, group4: Etch+CHX+SBU, group5: Etch+SBMP, group6: Etch+CHX+SBMP. After composite curing, w…
Durability of solvent-free one-step self-etch adhesive under simulated intrapulpal pressure
2015
Background: There are different solvents presented in simplified adhesives. Bond-1 SF has been developed, which contains neither water nor organic solvents, in order to eliminate technical issues in terms of evaporation of solvents and concerns for the durability of resin-dentin bond. Thus this study was conducted to evaluate the microtensile bond strength (μTBS) of solvent-free and ethanol-based one-step self-etch adhesives to dentin under simulated intrapulpal pressure (IPP). Material and Methods: Occlusal surfaces of human molars were prepared to expose mid-dentin depth. Bond-1SF Solvent-Free SE [SF] and Adper TM easy one [AE] adhesives were applied on dentin specimens. Resin composite b…
Taking advantage of the functional synergism between carbon nanotubes and graphene nanoplatelets to obtain polypropylene-based nanocomposites with en…
2020
Carbon Nanotubes (CNT) and Graphene Nanoplatelets (GNP) were incorporated in Polypropylene (PP) as single filler (CNT=1, 2 and 4 %wt. and GNP=2, 4, and 6 %wt.) and in hybrid form (CNT:GNP weight ratio 2:2, 2:4 and 4:2) using a prototype miniature Twin Screw Extruder (TSE) coupled with a double slit rheological die, in order to assess in-line the extent of nanofiller dispersion and to deliver PP-based nanocomposites with enhanced thermo-oxidative stability. The morphological, electrical and mechanical properties, as well as the resistance to thermal and photo degradation of the composites containing single nanofillers (PP/CNT and PP/GNP) were compared with those of hybrid PP based nanocompos…
La territorialisation comme condition de durabilité des organisations
2019
Insertion in territories allows an organization to cope with environmental and cultural changes, because territorial insertion allows face-to-face. This face-to-face depends on actors’ personal commitments but it can be facilitated or hindered by existing structures and institutions. A fossilized organization becomes incapable of adapting to environmental changes or to distinct institutional contexts. As the organization focuses on abstract issues, the concrete satisfaction of stakeholders is ignored for the benefit of a statistical representation which focuses on past realities. Reconstructing the face-to-face transforms the figured representation because the face-to-face brings additional…
Effect of external basalt layers on durability behaviour of flax reinforced composites
2016
Abstract Aim of this work is to evaluate the influence of external layers of basalt-mat on the durability behaviour of flax reinforced epoxy composites. To this scope, long-term ageing tests were performed on two different laminates in critical environmental conditions. The first laminate, named Flax, was constituted by stacking ten layers of bidirectional flax fabrics. The second one, named Flax–Basalt, was produced by replacing two external flax layers with two layers of basalt mat for each side of the laminate. Both laminates were exposed to salt-fog environmental conditions, according to ASTM B 117 standard, for 60 days. Five samples per laminate were removed from salt-fog spray chamber…
Durability of Basalt/Hemp Hybrid Thermoplastic Composites
2019
The Achilles heel of thermoplastic natural fibre composites is their limited durability. The environmental degradation of the mechanical properties of hemp and hemp/basalt hybrid-reinforced high-density polyethylene (HDPE) composites has been investigated with a special focus on the effects of water ageing and accelerated ageing, including hygrothermal and UV radiation. Modification of the matrix was carried out using a maleic anhydride high-density polyethylene copolymer (MAPE) as a compatibilizer. Hybridization of hemp fibres with basalt fibres and the incorporation of MAPE were found to significantly decrease the water uptake (up to 75%) and increase the retention of mechanical propertie…