Search results for "fiber"
showing 10 items of 2343 documents
Durabilità, in ambiente fortemente basico, delle fibre di PET provenienti dalla raccolta differenziata
2012
La sperimentazione esposta nella presente pubblicazione tratta dell’impiego di fibre di PET, ricavate dal semplice taglio di contenitori per bevande secondo un procedimento brevettato, nel rinforzo di calcestruzzi destinati anche a impieghi strutturali. Descrive le caratteristiche geometriche delle fibre e ne indaga la durabilità in condizioni severe che potrebbero presentarsi in un’applicazione pratica quale una pavimentazione esterna. A tal fine campioni costituiti da gruppi di fibre sono stati immersi per tredici giorni a 65°C in soluzioni a differente concentrazione di NaOH (0,103 M e 1,75 M). In particolare la soluzione a concentrazione 0,103 M di NaOH (pH=13) simula la basicità della …
Flexural Behavior of Steel Fibrous Reinforced Concrete Deep Beams
2012
Experimental research was carried out regarding the flexural behavior of deep beams cast with plain and fibrous concrete with hooked steel fibers, and subjected to monotonic vertical loads. Four deep fiber-reinforced concrete beams were cast. Two of them were made of plain concrete with main and web steel reinforcements (RC), and two were made of hooked steel fiber-reinforced concrete (SFRC) with main steel reinforcements. The experimental results show the brittle behavior of reinforced deep RC members characterized by crushing of concrete struts and fracture of web steel bars. SFRC deep beams exhibit higher strength and, above all, ductility with respect to RC members due to the bridging a…
Optical quality of hyperopic and myopic phakic intraocular lenses
2013
Aims: To assess and compare the optical quality of the myopic and hyperopic implantable collamer lens (ICL) from its wavefront aberrations for different powers and pupil diameters. Settings and Design: Prospective study. Material and Methods: The wavefront aberrations of two myopic (−3 and −6 diopters (D)) and two hyperopic V4b ICLs (+3 and +6D) were measured in vitro . To assess and compare the optical quality of different powers of ICLs, we analyzed the root mean square (RMS) of total higher order aberrations (HOAs), trefoil, coma, tetrafoil, secondary astigmatism, and spherical aberration at 3- and 4.5-mm pupil. In addition, the point spread functions (PSFs) of each ICL evaluated were ca…
Experimental Investigation on Stiffness and Strength of Single-Lap Z-Pinned Joints in a Laminated CFRP Stress-Ribbon Strip
2016
Carbon fiber-reinforced polymer (carbon-polymer) is an advanced lightweight composite material with high strength and excellent resistance to corrosion and fatigue. Over the past decades, application of fiber-reinforced polymers has been spread from the aerospace to other branches of industry such as automobile and civil engineering. Unidirectional carbon-polymers have a high potential for replacing steel in tensile members. Recently, the first carbonpolymer stress-ribbon bridge has been constructed in Germany. The non-laminated strip-loop carbon-polymer thin strips were used as the load bearing components in this bridge. In comparison with the laminated components, the applied cables are c…
Theoretical and Experimental Study of Polarization Modulation Instability in All-Normal Dispersion Photonic Crystal Fibers
2018
Experimental observation of polarization modulation instability in all-normal dispersion photonic crystal fibers is reported. Stokes and anti-Stokes sidebands with spectral shift of 40 nm were observed when the fiber was pumped at 1064 nm. Experimental results are baked by a vectorial four-wave mixing model.
Génération de similaritons optiques à 1550 nm par amplification Raman dans une fibre NZ-DSF
2004
Nous presentons la premiere observation experimentale de similaritons optiques generes par amplification Raman a 1550 nm dans une fibre a dispersion decalee. Une caracterisation FROG des impulsions indique un profil d'intensite parabolique et un chirp lineaire conformes aux predictions theoriques.
A DFT Study of Linear Gold–Thiolate Superclusters Absorbing in the Therapeutic NIR Window
2015
A series of linear clusters up to an aspect ratio of 1:6, formed as multimers of smaller clusters with an icosahedral Au13(5+) core having an eight-electron superatom configuration, are computationally predicted to have a greatly enhanced size-dependent absorption in the near-infrared (NIR) region extending to the biologically important NIR window. A novel structural model is presented for the previously isolated thiol-stabilized Au54(SR)30 cluster, where the metal core is formed as a heterodimer of the cores of the known Au25(SR)18(-/0) and Au38(SR)24 clusters.
Analisi quantitativa del tessuto tendineo di ratto adulto allenato
2011
Effect of NaOH Treatment on Properties of Phoenix Sp. Fiber
2016
The aim of this paper is to investigate the effect of an alkali treatment on physical, chemical, mechanical, and morphological properties of Phoenix Sp. fibers. The use of natural fibers as reinforcement in polymer composites requires a deep investigation to understand their behavior and which treatment is more appropriate to improve the quality of the untreated material. For this reason, fibers were extracted from the petioles of the Phoenix Sp. plant and they were treated with NaOH solution in different weight concentrations (5%, 10%, and 15%). The mechanical behavior was investigated through tensile test on single fiber at different gauge length (20 mm, 30 mm, 40 mm, 50 mm, and 60 mm). C…