Search results for "Self cleaning"
showing 5 items of 5 documents
Recent Development on Self-Cleaning Cementitious Coatings
2013
The recent improvements in nano-technologies applied to building coatings are reported, starting from the historical origins of the research on photocatalysis. The description of the main air pollutants and the chemical mechanism of photocatalysis introduce to self-cleaning surfaces and the super-hydrophilic and hydrophobic attitude. Self-cleaning cementitious surfaces, due to nano-structured photocatalysts, mainly titanium dioxide, show environmental benefit in reduction of air pollutants and many experimental evidences are reported together with several applications on building construction. International standards and main spectroscopic techniques aim to evaluate the benefit in terms of …
Evidence for a surface self-cleaning sputtering mechanism in fast atom bombardment mass spectrometry
1985
Evidence for a surface self-cleaning sputtering mechanism in fast atom bombardment mass spectrometry involving significant sputtering from the bulk of the glycerol matrix has been obtained from (a) the time dependence of sample ion abundances and chemical noise for bioorganic compounds, (b) determinations of the sputtering volume in glycerol solution, and (c) studies of in situ chemical and biochemical reactions. The relevance of these results for optimal sample/matrix preparation in analytical applications is pointed out.
Effectiveness of some protective and self-cleaning treatments: a challenge for the conservation of temple G stone in Selinunte
2021
Abstract The Temple G of the Archaeological Park of Selinunte (Italy), the largest in Europe, is one of the most impressive temples in the Magna Grecia. Today, it is completely destroyed due to a strong earthquake occurred in the Middle Ages. The used stone is a calcarenite coming from the ancient and renowned quarries of Cusa near the acropolis. This work comes from the today’s proposal of Temple G anastylosis. The goal of the work is to provide the results relating the protective effectiveness of three polymer formulations, appropriately selected, on stone samples taken from the “Capitello” quarry, part of “Cusa quarries”. The formulations functionality was deployed by adding TiO2 nanopar…
Highly efficient few-mode spatial beam self-cleaning at 15µm
2020
We experimentally demonstrate that spatial beam self-cleaning can be highly efficient when obtained with a few-mode excitation in graded-index multimode optical fibers. By using 160 ps long, highly chirped (6 nm bandwidth at -3dB) optical pulses at 1562 nm, we demonstrate a one-decade reduction of the power threshold for spatial beam self-cleaning, with respect to previous experiments using pulses with laser wavelengths at 1030-1064 nm. Self-cleaned beams remain spatio-temporally stable for more than a decade of their peak power variation. The impact of input pulse temporal duration is also studied.
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.