Polytechnic University of Turin

About: Polytechnic University of Turin is a education organization based out in Turin, Piemonte, Italy. It is known for research contribution in the topics: Finite element method & Nonlinear system. The organization has 11553 authors who have published 41395 publications receiving 789320 citations. The organization is also known as: POLITO & Politecnico di Torino.

Angle of arrival fluctuations for free space laser beam propagation through non kolmogorov turbulence

Abstract: Atmospheric turbulence induces significant variation on the angle-of-arrival of laser beams used in free space laser communication. Angle-of-arrival fluctuations of an optical wave in the plane of the receiver aperture can be described in terms of the phase structure function that already has been calculated by Kolmogorov's power spectral density model. Unfortunately several experiments showed that Kolmogorov theory is sometimes incomplete to describe atmospheric statistics properly. In this paper, for horizontal path and weak turbulence, we carry out analysis of angle-of-arrival fluctuations using a non Kolmogorov power spectrum which uses a generalized exponent factor instead of constant standard exponent value 11/3 and a generalized amplitude factor instead of constant value 0.033. Also our non Kolmogorov spectrum includes both inner scale and outer scale effects.

Design and scale‐up of chemical reactors for nanoparticle precipitation

Abstract: In recent years there has been a growing interest in production on an industrial scale of particles with size in the sub-micron range (40-200 nm). This can be done by controlling particle formation in order to nucleate very small particles and by tailoring the particle surface in order to avoid particle aggregation and produce stable suspensions. In this work we focus on the role of turbulent mixing on particle formation in confined impinging jet reactors. In particular, we show how computational fluid dynamics and simple precipitation models could be used to derive scale-up criteria for the production of nanoparticles. © 2006 American Institute of Chemical Engineers AIChE J, 2006

Methane combustion on Mg-doped LaMnO3 perovskite catalysts

Abstract: LaMn1−xMgxO3 perovskite catalysts (x=0–0.5) were synthesised by the so-called “citrates method”, characterised (chemical analysis, TEM, BET, XRD, temperature-programmed desorption of oxygen) and tested for their activity towards the catalytic combustion of methane. The role of MgO as a textural promoter, which hinders the sintering of the catalyst crystals by geometrical interposition, has also been assessed. Finally, a kinetics study was performed on the most promising catalysts prepared (LaMnO3 and LaMn0.8Mg0.2O3). The major results obtained are: (i) Mg substitution in the basic LaMnO3 perovskite has a positive effect on the catalytic activity only at low x values (x≤0.2); (ii) as opposed to the results of previous studies on the LaCr1−xMgxO3 system, the role of MgO as a textural promoter is not always significant and depends strongly on the calcination temperature of the samples (800–1200°C) and on the value of x; (iii) an Eley–Rideal mechanism could satisfactorily fit the experimental kinetics results for both catalysts, even though, as opposed to LaMnO3, the catalytic combustion over LaMn0.8Mg0.2O3 seems to involve two different types of adsorbed oxygen species, depending on the operating temperature.

Virucidal effect against Coronavirus SARS-CoV-2 of a silver nanocluster/silica composite sputtered coating

Abstract: During the current pandemic of COVID-19 caused by the new Coronavirus SARS-CoV-2, the confinement measures slowed down the contagion, but did not completely avoid the disease diffusion for health workers, patients and the remaining population. The individual protection equipment (e.g. facial masks), filters for air conditioning systems and for medical respiratory devices do not possess an intrinsic antimicrobial/virucidal action and they are susceptible to microbial/viral colonization. An efficient antimicrobial/virucidal technology on air filtering media is crucial for maintaining a safe air environment and protecting people, in particular when lockdown is eased. This short communication reports about the virucidal effect, preliminary verified towards Coronavirus SARS-CoV-2, of a silver nanocluster/silica composite sputtered coating, directly applicated on a FFP3 mask.