1,721,034 research outputs found
Il Valore di una Valutazione del Rischio Stress Lavoro-Correlato
No full textIl contributo riassume alcuni casi di valutazione del rischio stress lavoro-correlato svolte in aziende italiane
Mobbing: quali azioni preventive in azienda? Il punto di vista dei professionisti
No full textIl contributo presenta un metodo e un caso di valutazione applicato ad una grande azienda internazionale evidenziando le opportunità delle buone prassi
La valutazione e la prevenzione dei rischi stress e mobbing
No full textIl contributo evidenzia le buone prassi internazionali di prevenzione del rischio psicosociale e fa il punto sulla situazione italiana
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
DTPA-Functionalized silica-based monoliths for the removal of transition and lanthanide ions from aqueous phase
Full text linkTransition and rare-earth metals are essential raw materials used in a wide range of technological applications; moreover, their consumption is often associated with high production of wastes. Therefore, their recycling and recovery from end-of-life products or metal-contaminated aqueous environments is of considerable importance from a circular economy perspective. In our study, synthetic mesoporous silica monoliths, obtained by sol-gel synthesis[1] and functionalized with chelating groups are used for the recovery of metal ions from aqueous matrices (MONO-DTPA). The monoliths were characterized using a multi-technique approach and were tested in the recovery of paramagnetic Gd3+, Cu2+ and Co2+ ions from aqueous solutions, using 1H-NMR relaxometry to evaluate their uptake performance in real time and in simple conditions[2]. Detailed information on the kinetics of the capture process was also extrapolated. Finally, the possibility to regenerate the solid sorbents was evaluated. The modified silica monoliths were able to recover an appreciable amount of both di- and trivalent metal ions. The best results were obtained in the case of Cu2+ after 24 hours of contact, with a recovered amount of 0.29 mmol/g corresponding to 18.48 mg/g (Fig. 1, A).
The capture performance of MONO-DTPA has been shown to be superior to that of natural or synthetic materials commonly used for metal ion removal (Fig 1, B).
[1] V. Miglio, C. Zaccone, C. Vittoni, I. Braschi, E. Buscaroli, G. Golemme, L. Marchese and C. Bisio, Molecules 2021, 26, 1316
[2] S. Marchesi, S. Nascimbene, M. Guidotti, C. Bisio and F. Carniato, Dalton Trans. 2022, 51, 4502–4509
Influence of water on the retention of methyl t-butyl ether (MTBE) by high silica zeolites: A multidisciplinary adsorption study from aqueous solution and water vapour
No full textMethyl tertiary-butyl ether (MTBE) is a gasoline additive to increase octane ratings. MTBE is of particular concern due to its high aqueous solubility/vapour pressure and to its not readily biodegradability and potential human carcinogenicity. As suggested by U.S. EPA, it is of utmost importance the development of water remediation technologies to remove MTBE [Ref].
Zeolites are alumino-silicates of defined porosity, whose properties are related to the framework structural and chemical features. These properties can be modulated to increase their selectivity and sorbent activity. Here, the ability of two high silica zeolite (ZSM-5 and Y) to retain MTBE in the presence of water (i.e. from aqueous and gas phase) was addressed.
MTBE batch adsorption was performed and analyzed by HS-SPME-CG and TG and the exhausted sorbent investigated by XRPD. The Rietveld analysis allowed the identification of the occurrence and the positioning of MTBE-H2O clusters into the zeolite pores (see figure). The formation of clusters were also observed when the adsorption was conducted in gas phase in the presence of water vapour by variable pressure/temperature FTIR spectroscopy, thus highlightening the cooperative effect of H2O in MTBE removal by the zeolites. These findings are of certain interest for scientists working in the depollution of wastewater streams and indoor environments from oxygenated organic pollutants.
[Ref]: Braschi et al., 2012 J. Phys. Chem. C; Sacchetto et al., 2013 PCCP; Arletti et al., 2013 J. Solid State Chem.
Research funded by Research Center for Non-Conventional Energy, Istituto ENI Donegani – Environmental Technologie
The interface between alkylammonium ions and layered aluminophosphates materials: a combined theoretical and experimental study
No full textA combined theoretical and experimental approach to layered alkylamine-aluminophosphates
No full textComunicare ai gruppi durante i momenti di emergenza
No full textIl contributo si focalizza sulla comunicazione nei momenti di panico ed emergenza
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