Environmental Impact of Surgical Masks Consumption in Italy Due to COVID-19 Pandemic

The COVID-19 pandemic suddenly changed the lifestyle of billions of people. Face masks became indispensable to protect from the contagion providing a significant environmental impact. The aim of this work is to propose possible solutions to decrease masks’ impact on the environment. For this reason, different masks (surgical and fabric) were considered, and the CO2 emissions associated with the mask materials production were calculated. Carbon Footprint (CF) for each material composing the masks was evaluated through the database Ces Selector 2019. The software Qgis (version 2.18.20) allows us to elaborate the CO2 emissions maps for each Italian region. Finally, for surgical masks, which are often imported from abroad, the CF related to transport was considered. It results that fabric masks are a sustainable solution to prevent contagion. The total CO2 emission associated with the use of fabric masks from the beginning of the pandemic (March 2020) to December 2021 resulted in about 7 kton compared to 350 kton for surgical masks

Assessment of the influence of electric arc furnace slag as a non-conventional filler for Nitrile Butadiene Rubber

Reinforcement of polymers by the addition of particles filler is a complex phenomenon that depends mainly on the hydrodynamic effect and a complex interplay between polymer, filler, and interfacial region. Mineral fillers are usually adopted as low-cost extenders due to their lower cost. In this study, the influence of a waste material such as electric arc furnace steel slag is assessed as filler for Nitrile-Butadiene Rubber following experimental procedures and analytical calculations adopted for traditional fillers. It was found that the slag content affects the static and the dynamic properties by increasing the material's capability to storage and dissipate energy. In addition to an important contribution of the hydrodynamic effect, the presence of an increasing immobilized rubber fraction around the slag particles (quantified by a differential scanning calorimetry analysis) plays a central role. The slag stiffens the NBR composite; the increase of static tensile and dynamic shear storage moduli was found to be consistent with the Halpin-Tsai and Guth-Gold prevision models respectively. Moreover, the non-linear dynamic behavior was found to be well-fitted by the Kraus equation models. The reinforcing ability of the slag particles as filler was confirmed by the negative slope of the Kraus plot on swelling data

Application of benchtop total-reflection X-ray fluorescence spectrometry and chemometrics in classification of origin and type of Croatian wines

The contents of selected metals (K, Ca, Fe, Cu, Zn, Mn, Sr, Rb, Ba, Pb, Ni, Cr and V) in 70 wine samples from Continental and Adriatic part of Croatia and different types of wine (red and white) were determined by TXRF. The aim of this study was to compare the elemental composition of wines from two different regions and to determine the discriminant ability of each variable and to indicate which variables discriminate between the four categories considered. Principal component analysis and cluster analysis showed that K, Mn, Ba and Ni can be considered as the most important characteristics to distinguish between Continental red and white wines, Rb, Ni and Ba for Continental red and Adriatic red wines while Sr is the only metal that completely distinguishes the samples of each category. Finally, linear discriminant analysis showed good recognition (100%) and prediction abilities (96.43%) using these selected elements

waste silica sources as heavy metal stabilizers for municipal solid waste incineration fly ash

Abstract The present work discusses a new method, based on the use of silica fume, for heavy metal stabilization. The inertization procedure is reported and compared with other technologies, involving the employ of amorphous silica as stabilizing agent for municipal solid waste incinerator fly ash treatment (i.e. colloidal silica and rice husk ash). The obtained final materials are characterized in terms of chemical composition and phase analysis. The reported method, realized at room temperature, employs all waste or by-product materials. As a consequence it appears to be economically and environmentally sustainable

Evoluzione della microstruttura e dei microstrain dello strato funzionale di Pd per membrane dense per la separazione dell’idrogeno

In RSE negli ultimi anni sono state sviluppate membrane composite tubolari con strato funzionale di palladiocon spessore di 10-20 ?m, in grado di operare fino a 400°C, utilizzabili per la produzione di H2 e separazionedella CO2 nei processi di Water Gas Shift (WGS) del gas di sintesi e di reforming dell’etanolo, in configurazionedi reattore a membrana [1,2]. In questo lavoro, dopo una breve descrizione delle membrane tubolari conrivestimento funzionale di Pd per la separazione dell’idrogeno, vengono esposti i risultati della caratterizzazioneeffettuata sullo strato funzionale di Pd, mediante microdiffrazione dei raggi X con rivelatore bidimensionale,con microscopia elettronica (SEM-FEG +EDS) e spettroscopia Auger. Con la diffrazione X è stata valutatal’entità dei microstrain prima e dopo il trattamento di distensione e su membrane esercite. La spettroscopiaAuger ha permesso di rivelare la natura della contaminazione che probabilmente ha causato in alcuni casi ilsignificativo degrado delle prestazioni delle membrane. Al termine delle prove in impianto pilota la morfologiadella membrana di Palladio cambia in modo significativo sia in superficie che sulla sezione. Le misure XRD conrivelatore bidimensionale hanno consentito di studiare l’evoluzione della microstruttura delle membrane tubolaridovuta a trattamento termico a 400°C, soprattutto nelle fasi in cui avviene la permeazione dell’idrogeno

Foundry sand alkali activation for sustainable construction

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Thermo-mechanical behavior of surface acoustic waves in ordered arrays of nanodisks studied by near infrared pump-probe diffraction experiments

The ultrafast thermal and mechanical dynamics of a two-dimensional lattice of metallic nano-disks has been studied by near infrared pump-probe diffraction measurements, over a temporal range spanning from 100 fs to several nanoseconds. The experiments demonstrate that, in these systems, a two-dimensional surface acoustic wave (2DSAW), with a wavevector given by the reciprocal periodicity of the array, can be excited by ~120 fs Ti:sapphire laser pulses. In order to clarify the interaction between the nanodisks and the substrate, numerical calculations of the elastic eigenmodes and simulations of the thermodynamics of the system are developed through finite-element analysis. At this light, we unambiguously show that the observed 2DSAW velocity shift originates from the mechanical interaction between the 2DSAWs and the nano-disks, while the correlated 2DSAW damping is due to the energy radiation into the substrate.Comment: 13 pages, 10 figure