1,721,161 research outputs found
Rinnovabili, all'Italia serve una visione a lungo termine
No full textLA TRANSIZIONE VERSO LE ENERGIE RINNOVABILI FATICA A TROVARE STIMOLI, MA È GIÀ OGGI
TECNICAMENTE POSSIBILE. L’ITALIA PUÒ ESSERE PROTAGONISTA, MA SERVE LO SVILUPPO
DI UNA POLITICA NAZIONALE DISPOSTA A INVESTIRE E SOSTENERE LA RICERCA. VANNO POI
EVITATI ERRORI GROSSOLANI E INTERPRETAZIONI MALDESTRE SUL COSTO DELL’ENERGI
La fabbrica delle comunità solari. Domani smetto di fumare i combustibili fossili
No full textVuoi finalmente smettere di fumare i combustibili fossili? Allora questo manuale è proprio quello che fa per te: un approccio originale e molto pratico, attraverso un percorso di auto-aiuto per superare la tua dipendenza, entrando nelle comunità energetiche rinnovabili e costruendo città solari. La transizione energetica verso un mondo a energia rinnovabile è molto complessa, non da un punto di vista economico e neppure da quello psicologico, perchè dobbiamo rinunciare allo "sballo energetico" degli ultimi 100 anni. Il libro non parla di cambiamenti climatici, ma di problema energetico o meglio di trappola energetica da cui dobbiamo uscire velocemente per non perdere il controllo e per cogliere l'opportunità che abbiamo di fronte
Effect of methylene blue on electron mediated microbial fuel cell by Saccharomyces cerevisiae
No full textMicrobial fuel cells (MFCs) are bioelectrochemical reactors that directly convert the chemical energy stored in chemical bonds of organic substrates, to electrical energy. Saccharomyces cerevisiae was implemented as biocatalyst in the anaerobic anode compartment of an MFC using glucose as carbon source and methylene blue as electron mediator. Our results showed the effect of methylene blue on the microbial metabolism and the reversibility of the redox reaction of the shuttle mediator in the presence and the absence of a carbon source. The implementation of this reaction in a yeast catalysed MFC suggested that the electron transfer from the cells to the anode was certainly limited by the mediator concentration in the solution. However, a higher influence on the biopower generation of the MFC seemed to be linked to the yeast adsorption on the electrode surface than to the reduced methylene blue concentration in solution
Caratterizzazione dei vini dell’Emilia-Romagna mediante spettrometria di massa ad alta risoluzione e risonanza magnetica nucleare: caso di studio sui Lambruschi commerciali e sui vini di varietà minori di Vitis vinifera L. neoiscritti al Registro Nazionale delle Varietà di Vite
No full textIl progetto è stato svolto con l’obiettivo di trovare nuovi metodi alternativi ed a basso impatto ambientale per la caratterizzazione dei vini, commerciali e minori. Infatti, le analisi eseguite presso il Centro Interdipartimentale Grandi Strumenti (CIGS) di Modena, hanno permesso di analizzare i vini della famiglia dei Lambruschi, diventati ormai tra i vini più consumati ed esportati al mondo; i vini della famiglia delle Malvasie, che sempre più si stanno affermando sul mercato; i vini meno conosciuti dell’Emilia-Romagna, prodotti dal Centro di Ricerca delle Produzioni Vegetali (CRPV) di Cesena, sia rossi che bianchi. In particolare, per quel che riguarda i vini rossi, la metabolomica si è rivelata un approccio efficace, e l’utilizzo di strumenti di avanguardia quale lo spettrometro di massa ad alta risoluzione Orbitrap Q Exactive, ha permesso di individuare oltre 100 molecole di antocianine. Tra esse, oltre a quelle glicosilate, acetil-, coumaroil- e caffeoil-glicosilate, sono state individuate molte altre forme derivate, come ad esempio i di-glucosidi, che sono caratteristici delle viti americane, ma sono presenti in tracce anche nelle varietà di V. vinifera, così come le combinazioni con le catechine e le gallocatechine, a più alto peso molecolare. Infatti, i metodi analitici comuni quali spettrofotometria UV o cromatografia liquida UV, non permettono di vedere le molecole presenti in basse concentrazioni, a causa della minore sensibilità dei rivelatori. Inoltre, gli spettrofotometri UV permettono di individuare le molecole solo in base ai tempi di ritenzione di quest’ultime, che spesso co-eluiscono le une con le altre, nonostante il metodo cromatografico sia stato messo a punto in modo adeguato. Analizzando i dati tramite la Principal Component Analysis (PCA), l’Ancellotta è stata confermata, sia in termini di quantità sia come stabilità produttiva, come la varietà più interessante per la produzione di vino da taglio. Anche i Lambruschi Salamino, Grasparossa e Reggiano, sono facilmente distinguibili ed hanno dimostrato anch’essi un’ottima resa, in termini di colore. Dal punto di vista tecnologico, è stato possibile distinguere l’Ancellotta vinificata in rosso da quella vinificata in bianco. Infatti, quella vinificata in rosso, soprattutto nell’annata 2019, si distingue non solo per gli alti contenuti di antocianine glicosilate, che sono tipicamente le più ricercate dagli enologi, ma anche per la grande quantità di antocianine derivate citate precedentemente. Tra i vitigni minori, il Festasio si è rivelato il vino con delle caratteristiche molto simili a quelle dei vini già presenti in commercio, sia in termini qualitativi che quantitativi. Anche il Lambrusco di Fiorano (o Lambrusco del Pellegrino), tipico del Modenese, seppur con una colorazione meno abbondante, ha mostrato caratteristiche interessanti per la vinificazione del Lambrusco. Per quanto riguarda lo studio dei vini bianchi, è stata condotta un’analisi mediante Risonanza Magnetica Nucleare monodimensionale (1H-NMR), approccio tipico delle analisi “untargeted” delle matrici. Questo tipo di analisi, nonostante sia un’analisi più approssimativa rispetto alla spettrometria di massa, ha consentito di caratterizzare efficacemente i vini rossi minori descritti in precedenza, oltre ai vini bianchi minori di Caveccia, Vernaccia del Viandante, Bertinora e Vernaccina, un tempo diffuse soprattutto nelle province rivierasche del Mar Adriatico, e la Melara, originaria della provincia di Piacenza. In particolare, è stato possibile distinguere i vini minori dai vini già presenti in commercio, quali ad esempio i Lambruschi ed il Pignoletto. Di quest’ultimo, è stato inoltre possibile distinguere il prodotto commerciale, e quindi già rifermentato in bottiglia, dal prodotto non ancora rifermentato, con un contenuto alto di zuccheri residui, ed ancora di basso grado alcolico.The project was carried out with the aim of finding new alternative and low environmental impact methods for the characterization of commercial and minor wines. In fact, the analyzes carried out at the Centro Interdipartimentale Grandi Strumenti (CIGS) in Modena permitted to analyze the wines of the Lambrusco family, which have now become among the most consumed and exported wines in the world; the wines of the Malvasia family, which are increasingly establishing on the market; the lesser known wines of Emilia-Romagna, produced by the Centro di Ricerca delle Produzioni Vegetali (CRPV) of Cesena, both red and white. Regarding to the red wines, metabolomics proved to be an effective approach, and the use of cutting-edge tools such as the high-resolution mass spectrometer Orbitrap Q Exactive, permitted to identify over 100 anthocyanin molecules. Among them, in addition to the most known forms such as glycosylated, acetyl-, coumaroyl- and caffeoyl-glycosylated, many other derivative forms were identified, such as di-glucosides, which are typical of American vines, but are present in traces also in the varieties of V. vinifera, as well as the combinations with catechins and gallocatechins, with higher molecular weight. In fact, with common analytical methods such as UV spectrophotometry or UV liquid chromatography, it is not possible to see the molecules present in low concentrations, due to the lower sensitivity of the detectors. In addition, UV spectrophotometers allow the identification of molecules only based on the retention times, which often co-elute with each other, even though the chromatographic method has been properly developed. By analyzing the data through the Principal Component Analysis (PCA), the Ancellotta was confirmed, both in terms of quantity and production stability, as the most interesting variety to produce blended wine. Even the Lambrusco Salamino, Grasparossa and Reggiano, are easily distinguishable and have also shown an excellent yield, in terms of color. From a technological point of view, it was possible to distinguish the Ancellotta vinified in red from that vinified in white. In fact, the red vinified one, especially in the 2019 vintage, stands out not only for the high contents of glycosylated anthocyanins, which are typically the most appreciated by winemakers, but also for the large amount of derived anthocyanins mentioned above. Among the minor vines, Festasio proved to be the wine with characteristics very similar to those of the wines already on the market, both in qualitative and quantitative terms, and it can be used as blended wine. Lambrusco di Fiorano (or Lambrusco del Pellegrino), typical of the Modena province, even if with a less abundant color, also showed interesting characteristics for the vinification of Lambrusco. As for the analysis of white wines, an analysis was conducted using mono-dimensional Nuclear Magnetic Resonance (1H-NMR), a typical approach of "untargeted" analysis. This type of analysis, despite being a more approximated analysis than mass spectrometry, allowed the characterization of the minor red wines described above, as well as the minor white wines of Caveccia, Vernaccia del Viandante, Bertinora and Vernaccina, once widespread especially in the coastal provinces of the Adriatic Sea, and the Melara, originally from the province of Piacenza. Moreover, it was possible to discriminate minor wines from wines already on the market, such as Lambrusco and Pignoletto. Of the latter, it was also possible to distinguish the commercial product, and therefore already refermented in the bottle, from the product not yet refermented, and thus with a higher content of residual sugars, and still low in alcohol
La transizione energetica. Una piccola guida per capire come affrontare il cambiamento epocale del settore energetico
No full textLa transizione energetica: di che cosa si tratta?
È una domanda a cui molti non sanno dare una risposta precisa, perché
non hanno gli elementi per rispondere ad alcune questioni chiave: “Quali
sono le risorse energetiche necessarie per alimentare il nostro Paese? Chi
consuma? Dove prendiamo le risorse e per quanto tempo ne avremo? ”.
A questi interrogativi si aggiungono considerazioni più tecniche, legate
a come si può far funzionare un’auto o scaldare una casa con l’energia
rinnovabile oppure a come utilizzare in maniera efficace le fonti
energetiche rinnovabili che richiede la necessità di cambiare il sistema
energetico attraverso strade complementari
Questa piccola guida nasce per aiutare a orientarsi in questo quadro
complesso e in rapida evoluzione: un testo rigoroso, ma scritto in modo
semplice e accessibile a tutti, per capire come la transizione energetica
sta già cambiando la nostra quotidianità
Characterization of electron mediated microbial fuel cell by saccharomyces cerevisiae
Full text linkMicrobial Fuel Cells (MFCs) is an innovative technology able to both clean organic waste of domestic or industrial origin and produce renewable energy converting directly chemical energy stored in chemical bonds to electrical energy. Our findings showed that the rate of substrate consumption (such as glucose) by Saccharomyces Cerevisiae (a common baker’s yeast) in the anaerobic compartment of a dual chambered MFC presented a great potential to generate electrons in a microbial fuel cell. Methylene blue was used as the electronophore in the anode compartment, while oxygen and hydrogen peroxide were tested as electron acceptors in the cathode compartment. The experiment was performed in closed circuit configurations under different loads ranging for evaluating the performance of the MFC with different concentration of methylene blue and electron acceptor. The fuel cell mediated by methylene blue carried out a maximum power generation of 110 mWm-2 and generated a maximum open circuit voltage of 479 mV with a short circuit current of 1.17 Am-2 with hydrogen peroxide as electron acceptor. The different contribute on the cell output of the mediator and electron acceptor concentration in anode and cathode compartment have been studied
Characterization of electron transfer mechanism in mediated microbial fuel cell by entrapped electron mediator in saccharomyces cerevisiae
Full text linkAttributed to exponentially growing global energy demand in current scenario, microbial fuel cells (MFCs) are an attempt aimed towards achieving electric energy sustainability, using renewable resources such as the organic substrates in domestic or industrial wastewater. In our findings growing cells of common baker's yeast such as Saccharomyces cerevisiae was immobilized by inclusion techniques in cellulose acetate membrane on the surface of a graphite electrode. Immobilized cells were grown using nutrient broth while the substrate, like electron donor in MFC, was glucose. The rate of substrate consumption of the anode electrode indicated that Saccharomyces cerevisiae, also immobilised, had a huge potential to generate electrons. Our results showed that the current and voltage output of a Saccharomyces cerevisiae based MFC are directly correlated to the cells on the micro-environment of the electrode and to the presence of an electron mediator such as methylene blue (MB). Our findings suggested that reduced methylene blue was entrapped into the cells, enhancing the electron transfer on the graphite electrode as an internal mediator of the cellular metabolism, probably linked to the oxidative electron cascade
Energy from waste biomass: an LCA study on a biofuel cell at early design stage
No full textDiversifying energy sources and managing waste biomass are two pressing contemporary issues. The new technology proposed in this study aims to address both by converting waste biomass into energy and fertilizer through the use of a biofuel cell (BFC). The purpose of this study is to assess the environmental impacts associated with this innovative technology through a Life Cycle Assessment (LCA). To achieve the goal, the production and use of the cell were modelled, considering both laboratory-scale operations and industrial-scale approximations. The study explored alternative scenarios, such as sensitivity analyses involving different acids and bases, renewable energy sources, and heat recovery. Comparisons with conventional biomass waste treatments (anaerobic digestion and composting) demonstrated that the BFC technology remains competitive. To further improve the BFC’s environmental footprint, efforts should focus on reducing energy requirements and enhancing nutrient recovery during scale-up. These insights are crucial for advancing sustainable waste treatment technologies and maximizing the potential of discarded biomass in an environmentally friendly manner
Agro-food wastes for the release of phyto-chemicals and the production of enzymes by solid state fermentation using pleurotus ostreatus
Full text linkThe agro-food wastes represent a very important resource to recover chemical compounds with high added value that can be used in several industrial sectors and to the energetic production by biomass. This is a good method to value the agro-food wastes that are often undervalued. The hydrolitic demolition by lignocellulosic enzymes is one of the most studied approach for recovering phyto-chemicals from the cell wall of plants. Enzymes are perfect to this role, because they can be used in blind conditions resulting cheap and profitable. In this study, the concentration of reducing sugar (glucose) and total polyphenols (catechin), released in solution after the hydrolysis with lignocellulosic enzymes, were determined. The enzymes (extract enzymes) used are previously obtained, by growing the fungus Pleurotus ostreatus in solid state fermentations in presence of four separated agro-food wastes: grape stalks, grape seed, wheat straw and wheat bran. For the hydrolysis, the same biomass was used as substrates doing different combinations of substrate and enzymes extract (from different sources). The enzyme extracts from grapes stalks and wheat bran promoted the release of reducing sugars that were naturally rich in cellulase, pectinase xylanase activities. The wheat bran was the only matrix able to be hydrolyzed by all the enzyme extracts, probably due to the fact that its arabinoxylan structures are hydrolysable from the xylanase activities found in all the enzyme extracts. The increases on the polyphenols concentration during the hydrolytic reaction in oenological wastes were observed in the matrices rich in polyphenols such as grape seed and grape straw, even if the enzyme from the wheat bran was able to increase the content of polyphenols of 84 % compared to the initial one
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