1,720,985 research outputs found
Studi e Procedure per la Compatibilità Ambientale
No full textQuesto volume si pone l’obiettivo di descrivere le principali procedure tecnico-amministrative finalizzate alla regolamentazione delle diverse attività al fine di garantire la protezione ambientale e lo sviluppo sostenibile. La struttura del volume è pensata in modo date da dedicare un ampio spazio alla descrizione sia delle procedure, considerando gli adempimenti, le tempistiche, gli attori coinvolti, ecc., che della documentazione tecnica a supporto. Ad esempio, con riferimento alla procedura di Valutazione di Impatto Ambientale, alla descrizione dell’iter tecnico-amministrativo viene affiancata la definizione della struttura e dei contenuti e dello Studio di Impatto Ambientale, ovvero del principale documento tecnico a supporto della procedura stessa
Biopolymer production through Purple Phototropic Bacteria (PPB) and Activated Sludge (AS) by different engineering processing
Full text linkThe issue of treatment and disposal of sludge produced by wastewater treatment plants (WWTPs), has become relevant worldwide due to the high amounts of residual sludge to be managed, the stringent requirements for agricultural use of sludge, and the cost and disposal constraints associated to landfilling. In Europe, where the availability of fossil fuels is limited, combined treatment of sewage sludge and biowaste, aimed at recovering material and energy, appears to be promising. The present work investigates the feasibility of applying the so-called bio-refinery approach to bio-sludge from WWTP and organic waste, through the analysis of a combined process for converting organic waste (agro-industrial wastes and sewage sludge) into biofuels (bio-H2) and biomaterials (biopolymers).
The management of excess sludge from WWTPs is a critical issue due to the high costs and environmental implications. The conversion of a conventional WWTP into a biorefinery may contribute, while producing a high-quality effluent, to attaining the recovery of valuable elements, materials as well as energy. In particular, a suitable combination of treatment technologies may be directed to producing bio-H2 from mixtures of sewage sludge and agroindustrial biowaste in a first fermentative process stage, and bio-CH4 (under anaerobic conditions) or biopolymers (under aerobic/anaerobic conditions) in a subsequent treatment stage. Among the biopolymers, polyhydroxyalkanoates (PHAs), polyesters synthesized by numerous bacteria, appear to be the most attractive due to their thermoplastic properties similar to that of polypropylene (PP) (Carlozzi et al., 2018). So far, the application of mixed microbial cultures (MMCs) using complex residues for PHA production, through the application of transient carbon availability conditions (the so-called Feast and Famine (FF) strategy), has been widely investigated. However, PHA production with MMCs has been mainly restricted to the utilization of aerobic organisms. In recent years, different studies have proposed the utilization of phototrophic mixed cultures (PMCs). Phototrophic organisms can draw energy from sunlight and by not requiring oxygen to produce ATP, aeration is nonessential, and the high costs associated with system’s aeration can be eliminated. (Fradinho et al., 2013a). However, the research on the application of mixed microbial cultures (aerobic and anaerobic) for PHA production, have not yet achieved satisfactory results and needs further investigations applying waste complex feedstock in the process. The experimental campaign of this research project was developed in order to acquire the information necessary to derive the kinetics that describe the production processes of biopolymers, not only to evaluate the yields but also in qualitative terms, by different engineering processing. The specific targets of the research activities were the identification of the effect of different operating conditions on biopolymer production yields and kinetics and identification of the technical and environmental properties of the produced biopolymers. A first set of experiments, carried out at La Sapienza University of Rome with the participation of ACEA SpA, was designed to evaluate the optimal operating
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conditions to enrich the PHA-accumulating biomass from the aerobic biological sludge collected at a full-scale WWTP located in Rome. To achieve these targets a synthetic substrate, mimicking the composition of a VFAs-rich effluent from the dark fermentation of mixtures of pre-treated sludge and cheese whey (Akhlaghi et al., 2017), was used as the substrate of an aerobic process for biopolymer accumulation. This study aims to explore the capabilities of the mixed microbial communities (MMCs) to produce PHAs from artificial substrate and complex substrates such as organic waste in a SBR reactor. Five different cycles of SBR were run and 5 different OLR were tested: SBR 1/ SBR 2 (OLR 33 mmolC/ld), SBR 3 (OLR 100 mmolC/ld) SBR 4 (OLR 300 mmolC/ld) and SBR 5 (OLR 150 mmolC/ld). Considering the elements compared, it can be concluded that the operating conditions adopted with SBR3, with an organic load set at 100 mmolC / l d, were those that led to the best performance of the biomass selection and PHA production process, both in terms of productivity and polymer storage yields. PHA was reflected by a maximum accumulation percentage from 1 % up to 5 % (w/w) in 8 hours and a complete removal of C and N from the reactor. A second set of experiments was carried out at in collaboration with the Advanced Water Management Centre (AWMC) and the School of Chemical Engineering of the University of Queensland. This study was aimed to evaluate the PHA accumulation capacity by the use of another promising mixed culture: The Purple Phototrophic Bacteria (PPB). A continuous 2-L bench scale photo-anaerobic membrane reactor (PAnMBR), was used to test the ability to enrich PHA accumulating microorganisms from sewage sludge, using a synthetic substrate as in the previous experimental set of tests. The operative condition studied in this research had shown a potential capacity of PPB in the PHA accumulation process, reaching more than 15 % (W/W) content of PHA in the microbial cells and 61 % of COD removal and a complete N removal in each cycle. A third series of tests was carried out to investigate an alternative of the conventional biopolymer production setup, trying to minimize the cost of the oxygen supply and the use of expensive substrate. The Study of PHA accumulating capacity of PPBs growing under the natural light/dark cycle evaluating the effect of using molasses as sole carbon source were tested in an out-door 60 l flat plate photobioreactor. This study was carried in collaboration with the School of Chemical Engineering and Advanced Wastewater Management Centre (AWMC) of the University of Queensland (Australia). The operative condition studied in this research had shown a potential capacity of PPB in the PHA accumulation process from fermented molasses, reaching more than 13 % (W/W) content of PHA in the microbial cells and 61 % of COD removal. The results of the batch tests have confirmed the same accumulation capacity of the lab-selected culture so that strengthening the application of this experimental setup could help reaching more than 28 % of PHA content. The outcome of this study identified the PPB as one of the main interesting research challenges for industrial application of biopolymer production from waste
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
Variations on the Author
Full text link“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
Full text linkWe 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
Full text linkWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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