1,720,966 research outputs found
Water decontamination from organic micropollutants via photocatalytic solar systems based on WO3 photoanodes
No full textThe development of new materials and processes with a sustainable approach to allow an efficient removal from water sources of emergent contaminants, such as drugs and antibiotics, currently represents the next challenging task in water decontamination field. Photocatalysis and photoelectrocatalysis processes triggered via sunlight are among the most efficient Advanced Oxidation Processes for water decontamination. These methods are based on the interaction in water of natural light with oxide semiconductors, which generate high-reactive chemical species able to oxidize the organic micropollutants.
Here, the realization of two solar devices is presented, namely a parabolic concentrator and a modular stand-alone reactor. Their working principle is based on the photocatalysis and photoelectrocatalysis processes. As active material integrated within the solar devices, nanostructured tungsten trioxide was investigated via several realization techniques (solvothermal, electrochemical oxidation, and sol-gel) on glass and metal substrates. WO3-based electrodes attained photocurrents in the range of 1-5 mA/cm2, consistent with literature, and an activation in the visible part of the solar spectrum, up to 470 nm. Photodegradation tests, carried out on several specific drugs, showed outstanding results with an almost complete abatement in case of some pollutants, and a COD (Chemical Oxygen Demand) decrease of more than 60% in 1 h.
Both the solar devices could be scaled up in the next future for industrial scopes within the tertiary water treatment. Most importantly, they use a sustainable process, without additional energy costs, and with a possible hydrogen production as added value to the decontamination process.Nell'ambito del trattamento delle acque è emersa la necessità di sviluppare nuovi materiali e processi al fine di consentire un'efficiente rimozione di contaminanti emergenti, quali droghe e antibiotici, attualmente presenti nei bacini idrici, sfruttando un approccio sostenibile. I metodi di fotocatalisi e di fotoelettrocatalisi innescati da luce solare sono tra i processi di ossidazione avanzata più efficaci per la decontaminazione delle acque. Tali metodi sono basati sull'interazione in acqua di luce solare con ossidi semiconduttori; questa interazione genera specie chimiche altamente reattive, capaci di ossidare i microinquinanti organici, quindi purificando l'acqua.
In questo lavoro sono presentati due dispositivi solari, ossia un concentratore solare e un reattore autonomo modulare, il cui principio di funzionamento si basa sui processi di fotocatalisi e fotoelettrocatalisi. Come materiale attivo integrato all'interno dei dispositivi solari è stato studiato il triossido di tungsteno nanostrutturato. In particolare, diverse tecniche di realizzazione (solvotermale, anodizzazione elettrochimica, e sol-gel) sono state caratterizzate sfruttando substrati in vetro e metallo. Gli elettrodi basati su WO3 hanno raggiunto fotocorrenti di 1-5 mA/cm2, consistenti con quelle riportate in letteratura, e un'attivazione nella parte visibile dello spettro solare fino a 470 nm. I test di fotodegradazione, effettuati su alcuni specifici medicinali, hanno mostrato notevoli risultati, con un abbattimento pressoché totale di alcuni inquinanti, e una diminuzione di oltre il 60% del COD (Domanda Chimica di Ossigeno) in 1 ora.
Entrambi i dispositivi solari possono essere ampliati in un prossimo futuro a scopi industriali per il trattamento terziario delle acque, sfruttando un processo sostenibile, senza costi energetici aggiuntivi e con una possibile produzione di idrogeno come valore aggiunto al processo di decontaminazione
ANGELS (ANodi in GErmanio nanoporoso per batterie al Litio per applicazioni aeroSpaziali)
No full textIl progetto ANGELS (ANodi in GErmanio nanoporoso per batterie al Litio per applicazioni aeroSpaziali) vede come proponente l’Università di Ferrara nella veste del gruppo coordinato dal prof. Vincenzi insieme alla Fondazione Bruno Kessler di Trento, l’Istituto Italiano di Tecnologia di Genova e l’Università di Cagliari.
Questo progetto proseguirà una collaborazione già in atto da un paio d’anni tra questi enti, oggetto del lavoro di un dottorando la cui borsa è cofinanziata da Unife e FBK. Questa collaborazione ha permesso di sviluppare un anodo innovativo per batterie al litio in grado di fornire prestazioni fino a tre volte superiori rispetto agli attuali anodi in commercio, che usano come materiale attivo la grafite, invece del germanio utilizzato in questo progetto. Il livello tecnologico attuale corrisponde a un TRL3 mentre l’obiettivo del bando ASI sarà quello di arrivare ad un livello TRL4, avendo come settore di riferimento quello degli accumulatori per applicazioni aerospaziali.
Dato il potenziale interesse industriale dell’invenzione, è stata anche iniziata la procedura per il deposito di un brevetto italiano, sempre coordinato dall’Università di Ferrara, attraverso l’Ufficio di trasferimento Tecnologico.
Il budget del progetto e la suddivisione dei fondi tra i partner è riportato nella tabella seguente, in cui viene indicato il cofinanziamento a carico dei vari partner e il finanziamento a carico di ASI, che risulta essere il 65% del valore totale del progetto, come indicato espressamente nel bando. Il cofinanziamento dell’Università di Ferrara avverrà esclusivamente attraverso ore uomo mentre il finanziamento erogato da ASI per il suddetto progetto corrisponde al 100% di quanto chiesto nella sottomissione del progetto
Optical Characterization of a Red Dye Luminescent Solar Concentrator
No full textThe Luminescent Solar Concentrators (LSC) are innovative devices whose main application is the realization of transparent photovoltaic systems that are particularly interesting in the field of building integrated photovoltaics. Despite the great potentialities of LSC photovoltaic systems, up to now only a few real world applications exist and most of the scientific work about LSCs concerns only luminescent dyes and small size devices (generally 5×5 cm2). The purpose of this work is to investigate the optical behavior of a large (50x50 cm2) LSC slab that can closely represent the devices used in building integrated applications like roofs or windows. The output spectrum of the emitted light is measured while the LSC is illuminated in different positions with a round spot. With this setup it is possible to collect information about the contribution of radiative and non-radiative absorption to the performance of the system
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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