Search results for "Adhesive"
showing 10 items of 299 documents
Comparison of thermal expansion of wood and epoxy adhesives
2002
Epoxy-based adhesives are used both in the consolidation of decayed timbers and for new structural joints. Investigating the compatibility of wood and epoxy adhesives provides a better knowledge of the long-term behaviour of wood-epoxy joints. Besides mechanical compatibility, also temperature-related parameters are relevant in this context. The values of the thermal expansion coefficients (TEC) of two wood species (Spruce, Picea abies and Iroko, Clorophora excelsa) and four different epoxy resins have been compared using a modified test method that allows for nearly iso-hygric conditions of the wood specimens. Minor differences in TEC have been observed between wood in the transversal-to-t…
Comparison between FSW and bonded lap joints - A preliminary investigation
2017
Difficult to weld aluminium alloys can be effectively joined by different alternative processes. Friction Stir Welding (FSW), among the solid-state processes and adhesive bonding represent two very attractive techniques. They allow the production of highly resistant joints avoiding the formation of the typical fusion weld defects. The aim of this work is to identify, analyse and compare the mechanical properties of AA6016 aluminium alloy joints made out of 1 mm thick sheets. FSW lap joints were and epoxy bonded joints were produced. Using the FSW results as benchmark, the overlap required in the bonded joint was identified to ensure the same static strength. Once the geometric configuration…
Fibrin Sealants in Dura Sealing: A Systematic Literature Review.
2016
BACKGROUND:Fibrin sealants are widely used in neurosurgery to seal the suture line, provide watertight closure, and prevent cerebrospinal fluid leaks. The aim of this systematic review is to summarize the current efficacy and safety literature of fibrin sealants in dura sealing and the prevention/treatment of cerebrospinal fluid leaks. METHODS:A comprehensive electronic literature search was run in the following databases: Cochrane Database of Systematic Reviews, Cochrane Central Resister of Controlled Trials, clinicaltrials.gov, MEDLINE/PubMed, and EMBASE. Titles and abstracts of potential articles of interest were reviewed independently by 3 of the authors. RESULTS:A total of 1006 databas…
An in vitro comparison of different adhesive strategies on the micro push-out bond strength of a glass fiber post
2010
Objectives: To evaluate in vitro the push-out bond strengths of a glass fiber post adhesively luted with self-etching resin based and self-adhesive luting cements, as well as modified application procedure of self-adhesive luting cements in combination with single step self-etch adhesives. Materials and methods: Fifty single-rooted human maxillary central incisor teeth were endodontically treated and divided into five groups (n=10). Glass fiber posts (RelyX Fiber Post) were cemented with the following materials: group 1: ED Primer II/Panavia F 2.0 (PAN); group 2: RelyX Unicem (RU); group 3: Maxcem (MC); group 4: Adper Prompt L-Pop (PLP)/RelyX Unicem; group 5: Optibond all-in-one (OB)/Maxcem…
Enhanced one-component spray polyurethane foams via sol-gel microspheres doped with aqueous glycerol
2013
The sol-gel microencapsulation of aqueous glycerol in silica-based microspheres affords functional materials that can be used to cure one-component polyurethane foams (OCF) formulations affording better and greener foam formation. These findings are important and may open the route to more sustainable materials, such as foams, coatings, adhesives, and sealants that are widely utilized in many industrial sectors. © 2013 American Chemical Society.
The effect of glass ionomer and adhesive cements on substance P expression in human dental pul
2013
Objectives: The purpose of this study was to quantify the effect of glass ionomer and adhesive cements on SP expression in healthy human dental pulp. Study Design: Forty pulp samples were obtained from healthy premolars where extraction was indicated for orthodontic reasons. In thirty of these premolars a Class V cavity preparation was performed and teeth were equally divided in three groups: Experimental Group I: Glass Ionomer cement was placed in the cavity. Experimental Group II: Adhesive Cement was placed in the cavity. Positive control group: Class V cavities only. The remaining ten healthy premolars where extracted without treatment and served as a negative control group. All pulp sam…
Adhesive root hairs facilitate Posidonia oceanica seedling settlement on rocky substrates
2015
Posidonia oceanica, the dominant Mediterranean seagrass, has been historically described as a species typically growing on mobile substrates whose development requires precursor communities. During more than 10 years of direct observations, we noticed that P. oceanica seedlings were often firmly anchored to rocky reefs, even at exposed sites. Thus, we analysed the ultrastructural features of seedling root systems to identify specific traits that may represent adaptations for early seedling anchorage on rocky bottoms. Subapical sections of adventitious roots were obtained from 2-3 months old specimens collected in the field and were observed at SEM revealing an extensive coverage of adhesive…
Effect of hemostatic agent on marginal gaps of class V giomer restorations
2017
Background Contamination of dentin with hemostatic agents might exert a deleterious effect on adhesive procedures on dentin. The present study was undertaken to investigate the effect of aluminum chloride hemostatic agent on marginal gaps in Cl V giomer restorations. Material and Methods Fifty sound bovine permanent incisors were selected for the purpose of this in vitro study and Cl V cavities were prepared on their buccal surfaces; the gingival margins of the cavities were placed in dentin. The tooth samples were randomly assigned to two groups (n=25). The samples in groups 1 and 2 underwent a restorative procedure without and with the application of aluminum chloride hemostatic agent in …
Studio delle prestazioni di giunzioni incollate ibride
2011
Le giunzioni ibride sono giunzioni in cui coesistono due differenti tipologie di giunzione, di cui una è l’incollaggio. L’articolo mostra i risultati di una campagna sperimentale volta a caratterizzare le prestazioni di giunti incollati ibridi in confronto ad alcune tipologie di giunzioni tradizionali. Si sono prese in considerazioni come tecnologie di giunzione tradizionali la saldatura a resistenza, la rivettatura a strappo, la clinciatura e la rivettatura auto perforante. In particolare si sono studiate le prestazioni di giunti a semplice sovrapposizione per differenti condizioni geometriche del giunto (spessore aderendi, passo tra i punti di fissaggio meccanico) e condizioni ambientali …