Search results for "Cleaning"
showing 10 items of 77 documents
Spatio-Temporal Beam Mapping for Studying Nonlinear Dynamics in Graded Index Multimode Fiber
2020
We experimentally demonstrate high-resolution mapping of the spatio-temporal dynamics of the beam cleaning process in graded index multimode fibers. This high-resolution characterization reveals the time-dependent nature of the beam self-cleaning process.
Kerr Beam Self-Cleaning in Multimode Fibers
2018
We overview recent experimental results of beam self-cleaning observed in various types of multimode fibers. We analyze the output spatial beam shapes and their connection with the refractive index profile of the fibers.
Nanoclays for Conservation
2019
Within the conservation of artworks materials, this chapter describes innovative strategies based on clay nanoparticles that are promising for protective coating, surface cleaning, and consolidation. We present the preparation of polymer/montmorillonite nanocomposites, which are revealed as efficient protective coatings for highly porous stones, marbles, and bread-made artifacts. Anticorrosive films for metal substrates have been obtained by polymer filling with laponite and halloysite nanotubes (HNTs) containing corrosion inhibitors into their lumen. The dispersion of hydrophobically modified HNTs into chitosan matrix drives to fabricate biofilms with surface cleaning capacity. Rust stains…
Nonlinear beam self-cleaning in a coupled cavity composite laser based on multimode fiber
2017
International audience; We study a coupled cavity laser configuration where a passively Q-switched Nd:YAG microchip laser is combined with an extended cavity, including a doped multimode fiber. For appropriate coupling levels with the extended cavity, we observed that beam self-cleaning was induced in the multimode fiber thanks to nonlinear modal coupling, leading to a quasi-single mode laser output. In the regime of beam self-cleaning, laser pulse duration was reduced from 525 to 225 ps. We also observed a Q-switched mode-locked operation, where spatial self-cleaning was accompanied by far-detuned nonlinear frequency conversion in the active multimode fiber.
Spectrophotometric investigations at the museum: monitoring of colour changes during differentiated cleaning of the marble statues
2011
The spectrophotometric investigations carried out during the cleaning treatments on the marble surface provide an useful support for choosing the best method to employ by monitoring, before and after the tests, both the chromatic coordinates and the spectral reflectance. Moreover, the colorimetric measurements allow us to evaluate the goodness of the chromatic level and the uniformity of the cleaned areas. The Laboratory of Physics and Indoor Environment of the Regional Center for Planning and Restoration has carried out the spectrophotometric investigations on the marble statues belonging to the Renaissance statuary collection of the Regional Gallery of Sicily Palazzo Abatellis in Palermo …
Agatha, Apollonia, Magdalene and Rosalia. The Restoration of four Paintings of the Mother Church in Partinico and Their enhancement
2019
The conservative intervention on four paintings preserved in the mother church of Partinico, in the province of Palermo, has allowed the recovery and enhancement of an important pictorial patrimony. The intervention, restoring the optimal conditions of the artifacts, has made possible the stylistic interpretation of the paintings, today referred to the environment of Neapolitan naturalism close to the classicist ways of Andrea Vaccaro.
Laser assisted particle removal from Silicon wafers
2023
We have studied the removal of submicrometer particles from silicon wafers by the steam laser cleaning (SLC) and dry laser cleaning (DLC) processes. These processes are currently being investigated as new promising cleaning technologies for complementing traditional methods in industrial applications. For SLC a thin liquid layer (e.g. a water-alcohol mixture) is condensed onto the substrate, and is subsequently evaporated by irradiating the surface with a short laser pulse. The DLC process, on the other hand, relies only on the laser pulse, without application of a vapor jet. Using well-characterized monodisperse polystyrene and silica particles as well as irregularly shaped alumina particl…
The role of oxidation treatments before and after CVD synthesis of graphene on copper catalytic surface
2021
Graphene is a sheet of honeycomb bonded carbon, that is only one atom thick. Aside from its remarkable strength, graphene has great conducting and photochemical prop erties. Due to its unique properties, it can be used as viable option for rare metals in circuits and in new type of measuring components. To express these properties at their best, graphene should be single crystal and as clean as possible. In this bachelor thesis, different treatment options for catalytic metal surface for graphene synthesis are studied in chemical vapor deposition growth. Different options to treat the catalytic metal layer were studied, such as changes in gas compositions in annealing process, electropolish…
Media-fill simulation tests in manual and robotic aseptic preparation of injection solutions in syringes
2014
Objective The purpose of this study was to evaluate the contamination rate of media-fill products either prepared automated with a robotic system (APOTECAchemo™) or prepared manually at cytotoxic workbenches in the same cleanroom environment and by experienced operators. Media fills were completed by microbiological environmental control in the critical zones and used to validate the cleaning and disinfection procedures of the robotic system. Methods The aseptic preparation of patient individual ready-to-use injection solutions was simulated by using double concentrated tryptic soy broth as growth medium, water for injection and plastic syringes as primary packaging materials. Media fills w…
L’effetto della mitilicoltura posta a valle di allevamenti di specie ittiche riduce il carico organico
2007
L’utilizzo del mussel cleaning che sfrutta le caratteristiche fisiologiche dei molluschi filtratori per la mitigazione degli impatti derivanti da reflui particellati di origine antropica, ed in particolare delle attività di piscicoltura, è stato introdotto di recente in diversi paesi europei. Tale procedura si basa sull’ipotesi che la filtrazione operata da elevate biomasse di molluschi eduli posti nei pressi degli impianti di pescicoltura possa ridurre il carico organico in eccesso proveniente dal surplus di mangime fornito ai pesci allevati e che in certa parte inutilizzato tende a sedimentare al di sotto delle gabbie di allevamento. In questo studio abbiamo analizzato in due periodi diff…