Search results for "Fondamenti"
showing 10 items of 542 documents
Le interrelazioni tra algebra e geometria nella nascita delle strutture algebriche
2015
Lo studio dei fondamenti della geometria dopo la pubblicazione dei Grundlagen der Geometrie di Hilbert (1899), si è concentrato sull’analisi delle relazioni tra pro- prietà geometriche e proprietà algebriche. Questo filone di ricerche, si è inserito in quello già esistente dello studio dei sistemi di numeri ipercomplessi. Oggetto di questa comunicazione è analizzare il contributo di questi studi alla nascita delle strutture algebriche. In particolare, si prenderanno in considerazione i lavori di O. Veblen e J. H. Wedderburn e il programma proposto da M. Dehn e sviluppato da una sua studentessa R. Moufang e le ricadute di essi nella teoria e nella classificazione delle algebre.
A sustainable replacement for TiO2 in photocatalyst construction materials: Hydroxyapatite-based photocatalytic additives, made from the valorisation…
2018
The use of waste materials and by-products in building materials is of increasing importance to improve sustainability in construction, as is the incorporation of photocatalytic materials to both combat atmospheric pollution and protect the structures and façades. This work reports the innovative use of photocatalytic hydroxyapatite (HAp) based powders, derived from Atlantic codfish bone wastes, as an additive to natural hydraulic lime mortars. HAp is the main component of bone, and hence is non-toxic and biocompatible. This is the first time that such a calcium phosphate-based photocatalyst, or indeed any fish/marine derived wastes, have been added to building materials. A key factor is th…
Cobalt in strontium titanate based perovskites: preparation, characterization and role in the photocatalytic propene partial oxidation
2016
Strontium titanate perovskite (SrTiO3) and analogous materials in which Y partially substitutes Sr have been prepared as basis to integrate Co in the structure. The Co inserrtion has been performed by wet impregnation or coprecipitation methods. The obtained powders have been physico-chemically characterized and tested as photocatalysts in the propene partial oxidation by using a solar simulating reactor. Correlation between photocatalytic performance and physicochemical characteristics of the different catalysts allows to assess a key role of local nanostructuring of CoOx sites on the selectivity and distribution of products.
Role of the support on the activity of H3PW12O40 supported on SiO2 or TiO2 in Catalytic and Photocatalytic propene hydration: An EPR Study
2016
Catalytic and catalytic photo-assisted hydration of propene to 2-propanol in gas-solid regime at atmospheric pressure and 85°C were carried out by using the Keggin heteropolyacid (HPA) H3PW12O40 (PW12) supported on home prepared SiO2, WO3, TiO2 or N-doped TiO2. The HPA played the key role both in catalytic and photocatalytic reactions; however, the support strongly influenced the binary material performance. The contemporary presence of heat and UV light improved the activity of the (photo)catalysts. EPR (Electron Paramagnetic Resonance) has been used to understand the intimate mechanism underlying the photoactivity of the supported heteropolyacid and the role played by the support.
Moringa oleifera Leaf Powder as Functional Additive in Cookies to Protect SH-SY5Y Cells
2021
The aim of this work is the evaluation of the addition of Moringa leaf powder (MLP) in cookies in terms of antioxidant properties, dough processability and sensorial properties of the cookies. The total content of biophenols and flavonoids in MLP was detected and the identification of the bioactive molecules was performed by HPLC-ESI-TOF-MS measurements, before and after oven treatment at 180 ◦C for 20 min. After a preliminary evaluation of the MLP water soluble fraction (MLPsf) cytotoxicity, its protective effect against an oxidative injury induced in the SH-SY5Y cells was assessed. Data evidence that the bioactive molecules present in MLPsf are effective in preventing ROS production and i…
Alla base del processo: scientificità del progetto e attualità dei fondamenti teorici
2020
Di fronte a kaos e kosmos, ordine e disordine, teorizzazione generale e pensiero “debole”, modernità, postmodernità, surmodernità… l'uomo oggi non è in grado di formarsi un'opinione assoluta su nulla. Fare una scelta può creare problemi, forse anche disperazione, essere costretti a optare per più scelte conseguenti, come accade nel processo progettuale, può diventare davvero un dramma insolubile. Considerati questi aspetti, riteniamo sia necessario soffermarsi per fare alcune considerazioni (anche se relative e parziali) sulla disciplina, sui suoi fondamenti scientifici e sulla loro effettiva concretizzazione nel progetto architettonico. Possibili considerazioni sui fondamenti dell'architet…
Preface
2019
Preface of the book "Heterogeneous Photocatalysis Relationships with Heterogeneous Catalysis and Perspectives"
Influence of crystallinity and OH surface density on the photocatalytic activity of TiO2 powders
2014
Abstract The aim of the work was to study the influence of crystallinity and OH surface density on the photocatalytic activity of two commercial and two home-prepared TiO 2 powders. The samples were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TG) and electron paramagnetic resonance (EPR) measurements. The photoactivity of the powders was tested employing the photodegradation of 4-nitrophenol (4-NP) and the selective oxidation of 4-methoxybenzyl alcohol (4-MBA) to 4-methoxybenzaldehyde ( p -anisaldehyde) under UV irradiation. An anti-correlation between oxidant power and selectivity of the various samples was found. A higher rate of 4-NP degradation was exhibited by…
TiO2 Photocatalytic glucose conversion to H2 and high value chemicals
2015
In this work it is reported the conversion of glucose in aqueous dispersion of various TiO2 based photocatalysts. Aerobic and anaerobic conditions were used to study the distribution of the products both in the liquid (arabinose, gluconic acid, fructose and formic acid) and gas (H2 and CO2) phases. Commercial and home prepared bare and Pt-supported TiO2 samples were used as the photocatalysts.