Search results for "Mici"
showing 10 items of 1671 documents
Dosimetria a risonanza di spin elettronico (ESR) tramite composti organici (alanina e tartrato di ammonio) per campi misti neutroni-gamma
2014
Tuning The Selectivity To Aldehyde Via Ph Regulation In The Photocatalytic Oxidation Of 4-Methoxybenzyl Alcohol And Vanillyl Alcohol By Tio2 Catalysts
2021
Abstract The influence of pH on the photocatalytic partial oxidation of 4-methoxybenzyl alcohol (MBA) and vanillyl alcohol (VA) to their corresponding aldehydes in aqueous suspension under UVA irradiation was investigated by using poorly crystalline home-prepared and crystalline commercial TiO2 (BDH, Merck and Degussa P25) photocatalysts. The results clearly show as tuning pH can strongly impart selectivity and activity to photocatalytic processes which are often quite unselective in aqueous suspensions. It was found that pH effect on reaction rate and product selectivity strongly depended on TiO2 crystallinity and substrate type. In the case of MBA oxidation, photoreactivity and selectivit…
Osservazioni su contratti algoritmici e tutela del consumatore nell’economia di piattaforma
2020
Il saggio prende in esame alcune delle tutele predisposte dalla direttiva 2019/2161 del Parlamento e del Consiglio in favore del consumatore, nell’ipotesi in cui quest’ultimo sia assistito, nell’incontro con il professionista, dall’uso di tecnologie computazionali: con una espressione di sintesi, l’Autore si riferisce a questa evenienza con la locuzione “contratti algoritmici”. Tre sono gli aspetti cui si dirige l’attenzione: 1) la specificità dell’economia di piattaforma, luogo privilegiato in cui gli algoritmi orientano le scelte di consumo; 2) gli algoritmi che sono adoperati nell’atto di consumo; 3) l’ottimizzazione dei prezzi tramite profilazione automatizzata, quale caso paradigmatico…
Improved (photo)catalytic propene hydration in a gas/solid system by using heteropolyacid/oxide composites: Electron paramagnetic resonance, acidity,…
2017
Binary materials composed of the oxides SiO2, TiO2 and N-doped TiO2 and the Keggin heteropolyacid (PW12) were prepared and physicochemically characterized. They were used as catalysts and photocatalysts for the hydration of propene to 2-propanol. The characterization of the samples, particularly the electron paramagnetic resonance (EPR) spectroscopy results and the acidity properties, were useful to explain the key role played by the PW12 in the composite materials in the thermal and photoassisted catalytic processes. The simultaneous pres-ence of heat and UV light improved the activity of PW12 in the thermal process, and the binary materials showed better (photo)catalytic activities than t…
MODELLISTICA MATEMATICA E PIATTAFORME INFORMATICHE A SUPPORTO DELLA RICERCA AMBIENTALE
2021
La modellizzazione matematica è diventata ormai uno strumento essenziale nell’avanzamento delle conoscenze in qualsiasi campo della scienza, dall’econometria alla psicologia, dalla chimica all’epidemiologia, come vissuto di recente nella pandemia da SARS-coV-2. Anche quelle che erano una volta discipline “soft” come la biomedicina o l’ecologia possono ora usufruire di tecniche di rappresentazione ed esplicazione dei processi estremamente utili alla comprensione delle dinamiche in gioco. Questa evoluzione, dovuta in non piccola parte all’attuale disponibilità di abbondante potenza di calcolo elettronico a costi ridotti, non è però opera ed appannaggio soltanto della nostra generazione. Lo st…
Amicizia come pratica del riconoscimento in Nietzsche
2005
Analisi quantitativa dell'area del Golfo di Castellammare
2008
Analisi demografica, del mercato del lavoro, delle specializzazioni produttive e del dinamismo economico dell'area territoriale del Golgo di Castellammare.
Influence of fluorine on the synthesis of anatase TiO2for photocatalytic partial oxidation: Are exposed facets the main actors?
2018
Anatase TiO2 samples were synthesized in the presence of different amounts of HF acid with the aim of understanding the effect of the presence of fluorine on the photocatalytic activity. It is well known that the presence of fluoride ions influences the photocatalytic performance by adsorption on the surface of TiO2 and that they are capping agents in the control of specific exposed facets. The samples were characterized by X-ray diffraction (XRD), Raman spectroscopy, nitrogen adsorption–desorption measurements, scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV-vis spectrophotometry, and X-ray photoelectron spectroscopy (XPS). The photocatalytic activity was eva…
PHOTOCATALYTIC ACTIVITY OF TIO2 IN ITS POLYMORPHIC FORMS ANATASE, BROOKITE AND RUTILE
2012
Determination of the crystallinity of TiO2 photocatalysts
2018
Abstract This study reports a new simple method to determine the crystallinity of anatase and rutile TiO2 photocatalysts. The crystallinity degree of various anatase and rutile samples was estimated by XRD analysis from the ratio among the full width at half maximum intensities of the main diffraction peaks of anatase or rutile and the (111) peak of CaF2 as internal standard. The photocatalytic activity of selected powders was tested employing the photodegradation of 4-nitrophenol in aqueous solution as probe reaction. The results showed that the photoactivity of the investigated samples increased with increasing crystallinity and crystallite size.