109 research outputs found
Ambient Intelligence: una soluzione per anticipare i bisogni imparando dall'esperienza
Lo scopo della tesi è quello di proporre una soluzione praticabile per l'apprendimento di comportamenti ed abitudini degli utenti di un sistema domotico, con l'obiettivo di anticipare le loro esigenze; tale soluzione consiste nella realizzazione di un'applicazione che, integrando le tecnologie domotiche presenti sul mercato con i principi dell'apprendimento automatico, offra maggior comfort e sicurezza agli occupanti di un ambiente arricchito con dispositivi intelligenti, ponendosi come un primo passo verso la nascente disciplina dell'Ambient Intelligence
Development of methods for the determination of phytohormones in plant samples by HPLC-DAD/FD
Plant hormones are a group of naturally occurring, organic substances which influence physiological processes at low concentrations. The processes influenced consist mainly of growth, differentiation and development, though other processes, such as stomatal movement, may also be affected.
In this work phytohormones determination was performed by HPLC-DAD/FD. The method was applied to several plant samples, previously treated with a new polymeric phase synthetized in our lab
Synthesis, thermal, and mechanical characterisation of metakaolin-based geopolymers coloured with grape marc extract
Over the years, several materials have been used for restoration purposes, with different types of dyes and colour hues. Recently, some researchers have proposed geopolymers (GPs) or amorphous aluminosilicate polymers for these purposes. In this work, an alcohol-based grape marc extract (GME, obtained via dark maceration assisted with ultrasound) was used as a natural dyeing agent for metakaolin-based GPs. The geopolymerisation occurrence was assessed by Fourier-transform infrared (FT-IR) spectroscopy and X-ray diffraction analysis, while the colour of the resulting material was determined through
the colorimetric analysis in the L*a*b* colour space. Additionally, the thermal stability of GME and GPs was investigated by thermogravimetry coupled with FT-IR spectroscopy. The microstructure, the reticulation stability, and the antimicrobial activity of GPs were examined through the scanning electron microscopy, the pH and ionic conductivity measurements,
integrity, and mass loss tests. Overall, a coloured geopolymer with suitable thermal, antimicrobial, and mechanical properties was obtained, justifying its potential use in restoration or, more generally, in the construction field
Guidelines for a correct evaluation of deep eutectic solvents thermal stability
Deep eutectic solvents (DESs) are a class of versatile and green emerging materials. Despite the huge amounts of applications proposed in the last years, studies on their thermal stability are often missing. In this short review, we propose a guide for a correct evaluation of DES thermal stability, conducted mainly by dynamical thermogravimetry (TGA). We collected all the data reported in the literature on choline chloride (ChCl)-based DESs, as proof of concept to show the potentialities of the technique, highlighting all the parameters that need to be considered for a correct analysis, with particular attention to the possible sources of misleading interpretations (e.g. the adsorbed water, or the formation of undesired products during DES preparation). In many cases, the additional use of isothermal TGA, or TGA coupled with online techniques such as Fourier Infra-Red Spectroscopy or Mass Spectrometry, may help for the data interpretation. Besides, we summarize in a graph the degradation temperatures of many DESs and their precursors, intended as an operative guide to choosing the correct DES for different applications. The findings reported to date, highlight the potentialities of thermal analysis on DESs, as a powerful tool to obtain essential information on their applicability, and to implement the knowledge of their nanostructure from a molecular point of view
20 years of microwave technology developments using a coaxial antenna: From human health to green chemistry applications
The global interest on microwave assisted chemistry (MAC) is due to the important benefits for the sustainable
growth of green chemical industries and environmentally friendly progress of society. MAC has been firstly
developed using oven-type microwaves (MWs) assisted reactors, which requires difficult and expensive industrial
scale-up. In 2002, the development of coaxial dipole antenna allowed a direct application of MWs in situ in the
reaction media, opening a crucial, novel versatile technological solution, making MW-assisted processes feasible
in any configuration at any industrial level. Here, we present an overview of the technological development of 20
years research using a coaxial MW antenna for green chemistry and human health applications. The major MW
technology breakthroughs described in these short-review are: i) MW-induced thermoablation machine, ii) in situ
MW heating in open glassware chemical reactors, iii) electrodeless MW/ultraviolet (UV) lamps and photoreactors,
iv) MW-high pressure reactor and v) solventless/simultaneous MW/UV/ultrasound (US) configurations. Applications
for the synthesis of nanocatalysts, nanoparticles and polymers, advanced oxidative decomposition
photochemical processes, solvothermal extraction of valuable products and biomass processing are discussed.
Remarks on the scaling up of the extraction processes and frontier applications addressed to the treatment of
current and future outbreak pandemic emergences are also shown
Thermal and morphological investigations of alkali activated materials based on Sicilian volcanic precursors (Italy)
Insights on thermal behavior and microstructures of AAMs based on Sicilian volcanic precursors (i.e.,
volcanic ash, "ghiara" and pumice) have been performed. A multidisciplinary approach by means of
thermogravimetric analysis coupled to Fourier Transform Infrared Spectroscopy and X-ray Computed
Microtomography has been used with the aim to define the influence of reactants involved in the process.
The obtained results show: i) the increase of metakaolin shifts the gas emission toward lower
temperatures; ii) the positive relation between mass loss and liquid/solid ratio; iii) the influence of particle
size of precursors on the pore development
Valorization of not soluble byproducts deriving from green keratin extraction from poultry feathers as filler for biocomposites
The valorization of poultry feathers wastes is very important to reduce the environmental pollution deriving from their disposal. In this frame, we present the production process of completely natural, biodegradable, biocompatible, and eco-friendly composites made by not soluble keratin (NSK) and poly(lactic acid) (PLA). NSK has been obtained as a byproduct of a microwave-assisted keratin extraction from poultry feathers and it has been added to PLA pellets without adding any additional compatibilizers or plasticizers, unlike from the other works reported in the literature until now. The mixture has been used to obtain homogeneous NSK-based PLA filaments by means of hot-melt extrusion technology. The filaments have been subsequently 3D printed to explore applications in the additive manufacturing field. All the samples have unaltered thermal stability, but reduced toughness with respect to neat PLA. Other tested parameters (water adsorption, glass transition, and crystallinity) are dependent on NSK content and fabrication technology. Besides, Fourier Transform Infrared Spectroscopy highlights the differences in the structure of the NSK-based PLA filaments and 3D printed samples
One-pot process: Microwave-assisted keratin extraction and direct electrospinning to obtain keratin-based bioplastic
Poultry feathers are among the most abundant and polluting keratin-rich waste bio-masses. In this work, we developed a one-pot microwave-assisted process for eco-friendly keratin extraction from poultry feathers followed by a direct electrospinning (ES) of the raw extract, without further purification, to obtain keratin-based bioplastics. This microwave-assisted keratin extraction (MAE) was conducted in acetic acid 70% v/v. The effects of extraction time, solvent/feathers ratio, and heating mode (MAE vs conventional heating) on the extraction yield were investigated. The highest keratin yield (26 ± 1% w/w with respect to initial feathers) was obtained after 5 h of MAE. Waste-derived keratin were blended with gelatin to fabricate keratin-based biodegradable and bio-compatible bioplastics via ES, using 3-(Glycidyloxypropyl)trimethoxysilane (GPTMS) as a cross-linking agent. A full characterization of their thermal, mechanical, and barrier properties was performed by differential scanning calorimetry, thermogravimetric analysis, uniaxial tensile tests, and water permeability measurements. Their morphology and protein structure were investigated using scanning electron microscopy and attenuated total reflection-infrared spectroscopy. All these characterizations highlighted that the properties of the keratin-based bioplastics can be modulated by changing keratin and GPTMS concentrations. These bioplastics could be applied in areas such as bio-packaging and filtration/purification membranes
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