1,721,149 research outputs found
Metodo per separare e recuperare polietilene e alluminio da un materiale poliaccoppiato
No full textL’invenzione fa riferimento ad una nuova tecnologia a base di switchable hydrophilic solvents (SHS) per la separazione e recupero di polietilene a bassa densità (LDPE) e alluminio da imballaggi alimentari (poliaccoppiato). Il nuovo metodo, interamente sostenibile, consente il recupero di entrambi i materiali in elevate quantità (> 99% per l'alluminio e > 80% per il polietilene) e buona qualità (≥ 86% di alluminio non ossidato). L’invenzione appartiene agli approcci chimici per separare LDPE e alluminio da residui sminuzzati di poliaccoppiat
Effects of ionic liquids on membrane fusion and lipid aggregation of egg-PC liposomes
Full text linkIn this study we have explored the effects of different groups of ionic liquids (ILs) on membrane fusion. The ILs used contain different head groups: N-methylimidazolium, 3-methylpyridinium and N-methylpyrrolidinium; short alkyl or ether functionalized side chains (with one or two ethoxy functionalities), paired with chloride anion. These ILs have been compared with 1-dodecyl-3-methylimidazolium bromide as example of a highly lipophilic IL. The effect of ILs on membrane fusion was investigated through pyrene steady state fluorescence probing, using the IE factor and excimer/monomer ratio (IE/IM) as parameters. The ratio between the vibronic bands of pyrene (I1/I3 ratio) has been used to monitor the effect of ILs on the aggregation properties of egg-PC liposomes. The effect of different ILs’ families was evident; the pyridinium ILs induced a greater extent of fusion than pyrrolidinium and imidazolium ILs having the same side chain. Marginal effect could be attributed to different anions. ILs with short alkyl chains were usually more effective than ether functionalized ones. The aggregation behaviors of ILs having dioxygenated chains have been measured in buffer solution
Surfactants from Itaconic Acid: Physicochemical Properties and Assessment of the Synthetic Strategies
No full textSurfactants are a wide class of compounds used in a broad spectrum of industrial and everyday applications. In this paper, we present the synthesis of a new family of surfactants having C12 and C18 alkyl chains obtained from itaconic acid and fatty amines, molecules industrially obtained from renewable resources. Main physicochemical properties of synthesized surfactants have been measured and their rheological behaviors have been evaluated at the air-water interface using the pendant drop technique. Some of the synthesized surfactants are stimuli responsive compounds, switchable to a polar form in the presence of CO2. The synthetic strategies have been optimized aiming at the sustainability of the process employing a complete set of green metrics and the software EATOS
Multicomponent Cascade Synthesis of Biaryl-Based Chalcones in Pure Water and in an Aqueous Micellar Environment
No full textThe challenging multicomponent cascade synthesis of biaryl-based chalcones was carried out in pure water and in an aqueous micellar system. The first step of the protocol was a simple Pd-catalysed, ligand-free, and aerobic Suzuki–Miyaura reaction in aqueous medium. This proved to be extremely efficient for the coupling of aryl and heteroaryl bromides with different arylboronic acids. Subsequently, the resulting intermediates underwent an in-situ aldol condensation reaction to give biaryl(hetero)chalcones in good to excellent yields. When the protocol was applied to highly lipophilic or less reactive reagents, micellar catalysis was required for good results. To achieve this, we successfully used a new surfactant obtained from renewable resources that we recently designed. Furthermore, using this additive, the catalytic system can be repeatedly recycled without significant loss of activity
Inter- and Intraspecific Variability of Nitrogenated Compounds in Gorgonian Corals via Application of a Fast One-Step Analytical Protocol
No full textGorgonian corals play a structural role in temperate and tropical biogenic reefs, forming animal forests and creating biodiversity hot spots. In the Mediterranean Sea, slow-growing and long-lived gorgonian species are threatened by human disturbances and global environmental changes and concern about their conservation is rising. Alkaloid metabolites have proven to be essential in protecting these species from environmental stressors. Traditional profiling methodologies to detect these metabolites require a large quantity of living tissue. Here, the chemodiversity of gorgonian alkaloids was investigated by applying a fast and effective protocol combining extraction and derivatization using small-scale tissue samples and GC/MS analysis. The method was effective in identifying and quantifying alkaloids and guanine-based compounds. Eight N-heterocyclic compounds were found in six Mediterranean gorgonians differing for types and quantity. The metabolomic profile was conservative in species of the Eunicella genus, with three species sharing the same pattern. Conversely, Paramuricea clavata displayed a noticeable spatial pattern of variation among colonies collected in different locations. The analytical approach presented here proved to be effective, allowing rare, endangered, and small-sized species to be screened rapidly for detection of new compounds in order to explore their biological and ecological functions
Life Cycle Assessment of a novel process of polyhydroxyalkanoates production with waste and by-products from wine industry value chain
No full textEU wine production accounts for some 60 percent of worldwide output, with France and Italy being the largest wine producer countries in the world (Gaeta and Corsinovi, 2014). The wine industry influences the environment with the use of soil, water, energy, fertilizers and pesticides. In addition it produces liquid and solid organic waste that has to be managed in the proper manner in order to minimize environmental impacts. In recent years, some innovative technologies have been proposed for the valorization of winery waste and by-products (i.e. grape marcs, grape seeds, vinification lees, etc.) (Devesa-Rey et al., 2011). VALSOVIT is a research project funded by Emilia Romagna Region (Italy) which aims to valorize wine industry by-products. Its focus is the development of an integrated strategy for the transformation of waste from the whole oenological supply chain into high added-value products such as polymers, base chemicals, and molecules for the nutraceutical, cosmetic and agrochemical industries. In this framework, a novel experimental process for the valorization of wine lees and sewage sludge is carried out. These winery residues are subject to anaerobic acidogenic fermentation in order to produce volatile fatty acids (VFAs), which in turn are used to feed a mixed microbial community (MMC) able to accumulate polyhydroxyalkanoates (PHAs) granules as carbon and energy intracellular reserve. The last step consists of PHAs extraction using dimethyl carbonate (DMC). Life cycle assessment is applied to calculate and compare the environmental impacts related to the production of one kg of PHAs to those of an analogous amount of a fossil-based plastic (polypropylene, PP), and two bio-based plastics (bio-polypropylene, bio-PP, and polylactic acid, PLA). PHAs produced from wine industry residues show mixed results. Four different scenarios which vary in terms of feedstock used and pre-treatment process are analyzed. Results show that system setup including pyrolysis pre-treatment allows to reduce both energy demand and GHG emissions more efficiently than the setup without pyrolysis. The latter, on the other hand, is technologically simpler and therefore less effort and cost consuming than the one including pyrolysis. No significant differences between the two feedstock used are found in the results. Gaeta and Corsinovi, 2014. Economics, Governance, and Politics in the Wine Market. Palgrave Macmillan, US. Devesa-Rey et al., 2011. Waste Management. 31:2327-233
Source Attribution of Water-Soluble Organic Aerosol by Nuclear Magnetic Resonance Spectroscopy
No full textFunctional group compns. of atm. aerosol water-sol. org. compds. were obtained using proton NMR (1H NMR) spectroscopy in recent expts. worldwide characterized by different aerosol sources and pollution levels. The feasibility of using 1H NMR functional group distributions to identify aerosol sources in different areas is discussed. Despite limited variability of functional group compns. of atm. aerosols, characteristic 1H NMR fingerprints were derived for 3 major aerosol sources: biomass burning, secondary formation from anthropogenic and biogenic volatile org. compds., and oceanic emissions. Functional group patterns obtained in areas characterized by one of the above dominant source processes were compared to identify the dominant sources for mixed source samples. This anal. showed that 1H NMR spectroscopy can be used as a valuable tool for aerosol source identification. Also, compared to other existing methods, it could relate source fingerprints to integral chem. properties of org. mixts., which det. their reactivity, physicochem. properties, and ultimately the atm. fate of org. particles
Extraction of polyhydroxyalkanoates from mixed microbial cultures: Impact on polymer quality and recovery
Full text linkPolyhydroxyalkanoates (PHAs) can be extracted from mixed microbial cultures (MMCs) by means of dimethyl carbonate (DMC) or combination of DMC and sodium hypochlorite (NaClO). The protocol based on DMC, a green solvent never used before for the extraction of PHAs from MMC, allows an overall polymer recovery of 63%; also the purity and the molecular weight of the recovered polymers are good (98% and 1.2 MDa, respectively). The use of NaClO pretreatment before DMC extraction increases the overall PHA recovery (82%) but lowers the mean molecular weight to 0.6–0.2 MDa. A double extraction with DMC results to be the method of choice for the recovery of high quality PHAs from attractive but challenging MMCs
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
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