Search results for "010406 physical chemistry"
showing 10 items of 12 documents
Portability in analytical chemistry: a green and democratic way for sustainability
2019
International audience; Recent advances in portability of analytical equipment have been considered to enlighten the advantages offered by portable instrumentation on greening the analytical methods. Their use drastically reduces sampling, sample stockage, and transport, thus avoiding environmental side effects and risks, also improving decision-making. The fact that portable instrumentation is, in general, less expensive than bench instruments and apparatuses makes also available the analytical tools for extended sectors of the population, thus making accessible the advantages derived from analytical methods. The role of sensor technology and portable miniaturized systems has been consider…
First results of iButton® loggers and infrared camera application inside a greenhouse
2017
Greenhouse microclimate management (temperature, relative humidity) plays a very important role in order to optimize the production process improving pest and disease control, irrigation and energy efficiency. The systems mostly used in Sicily (south Italy) to record the ambient parameters are made up of fixed measuring stations able to give useful information about the climate inside the greenhouse limited to some pre-fixed points. In this study we texted a novel system made up of humidity and temperature data loggers (iButton®) placed inside a greenhouse. The iButton® temperature/humidity logger (DS1923) is a rugged, self-sufficient system that measures temperature and/or humidity and r…
Microwave heating of water in a rectangular waveguide: Validating EOF-Library against COMSOL multiphysics and existing numerical studies
2019
The purpose of this work is two-fold: first, we successfully validate our open-source tool EOF-Library, which efficiently couples Elmer FEM and OpenFOAM, against COMSOL Multiphysics, a commercial simulation package; second, we inform about significant discrepancies between our results and the experimental and simulation data found in a series of research papers. We reproduce the previously published numerical simulations wherein microwaves are supplied to a water domain through a rectangular waveguide, inducing convective flow. This is a conjugate problem with weakly coupled electromagnetics, heat transfer and fluid dynamics. It involves effects such as permittivity dependence on temperatur…
Polymeric micelles as a new generation of anti-oxidant carriers
2017
A promising strategy to immobilize a natural stabilizer in polymeric films is presented. Par-Ticularly, nevadensin (N, a natural basil flavonoid) molecules have been encapsulated in Pluronic F-127 micelles [F127, a triblock copolymer poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)] and the obtained nanoparticles have been introduced in poly(ethylene glycol), PEG [otherwise known as poly(ethylene oxide), PEO]. In order to verify the effectiveness of the micelles as anti-oxidant carriers, PEG-based films have been subjected to artificial weathering. The encapsulation of anti-oxidant molecules allows the enhancement of N solubility in PEG, leading to advanced materials with enh…
Thermal behavior of ethylene copolymers with di- and tri-alkenylsilsesquioxane comonomers synthesized by post-metallocene catalysts
2020
AbstractThis paper reported thermal properties of ethylene copolymers with di- and tri-alkenylsilsesquioxanes (POSS) synthesized by bis(phenoxy-imine) Ti, Zr, V, and V salen-type complexes. Ethylene copolymers with multi-alkenyl POSS obtained by such complexes contain multi-alkenyl POSS incorporated into the polymer chain as a side group. They were characterized by different thermal behavior depending on the kind of multi-alkenyl POSS comonomer, and type of the catalyst used, as well as polymerization conditions and thus the structure of the copolymer chain. Ethylene/POSS copolymers differed in incorporation of POSS into the polymer chain, content of specific unsaturation groups, and molecu…
Interface thermodynamic model for low pressure evaporation
1979
Analysis of microplastics and nanoplastics: How green are the methodologies used?
2021
Microplastic (MP) and nanoplastic (NP) pollution is among the global environmental concerns of the 21st century owing to its transboundary distribution and persistence. The number of studies focused on the determination of MPs in air, water, sediment, soil, and biota of an important number of ecosystems has increased exponentially. However, the impact that the methodologies used to isolate and determine MPs and NPs have on the environment owing to the consumption of reagents and energy and the generation of waste is not yet studied. This review presents a critical overview of the analytical methodologies applied to determination of MPs and NPs assessing their greenness using the National En…
Adsorption isotherms and thermal behavior of hybrids based on quercetin and inorganic fillers
2019
We investigated the adsorption process of quercetin onto several inorganic fillers, such as kaolinite, calcium carbonate and alumina. Firstly, we performed equilibrium adsorption studies in order to determine the quercetin/filler adsorption isotherms, which were successfully fitted through the Langmuir model. Based on the adsorption data analysis, we estimated the maximum adsorption capacity of each filler as well as the Langmuir constant, which is related to the affinity between quercetin and the surfaces of the inorganic particles. Then, we prepared hybrids formed by fillers saturated with quercetin. The obtained composites were characterized by thermogravimetric analysis with the aim of …
Non-isothermal thermogravimetry as an accelerated tool for the shelf-life prediction of paracetamol formulations
2021
Abstract In this work, non-isothermal thermogravimetric studies have been carried out on several paracetamol formulations with the aim to predict their shelf-lives under variable storage conditions. Specifically, paracetamol tablets of different brands have been investigated allowing to estimate their pharmaceutical quality by considering the specific drug stability. The proposed protocol is based on the kinetic study of thermogravimetric data by the combination of isoconversional procedures (Friedman and Kissinger-Akahira-Sunose (KAS) methods) and “Master plot” analysis. Accordingly, the kinetics of the paracetamol degradation is totally explored in terms of activation energy, pre-exponent…
Greening the wastes
2019
Problems associated with analytical waste toxicity and waste treatment are reviewed in the frame of the water treatment, being collected a series of models, from the big-scale treatment of waste waters and adapted to the effluents generated during sample analysis. In fact to move from wastes to clean or no-contaminant wastes is a way from greening those methods in which any sample treatment and the use of reagents and solvents cannot be avoided. The last contributions in the field have been taken into account in this study and future trends have been proposed.