1,720,964 research outputs found
Treatment and management of the effluents generated by hydrometallurgical processes applied to End-of-Life Photovoltaic Panels
No full textPhotovoltaic (PV) technology is a low-carbon and efficient option to produce electricity with an expected growing market. In the next years, end-of-life PV panels (EoL PV) will generate a new type of waste whose management implies environmental concerns but also opportunities to recover secondary raw materials. As part of a European project, a 1,500 panels/year capacity pilot plant to recover valuable resources from EoL PV panels using hydrometallurgical processes was operated in real environment. It represents the first time that a hydrometallurgical treatment was applied, at industrial scale, to EoL PV panels. This study focuses on the specific topic of treating the wastewater generated by the end of the hydrometallurgical process. Different chemical and physical tests were tried in laboratory on such streams loaded with metal species. The experimental results indicated that induced precipitation by adding strong acid or alkaline solutions allows obtaining high metal removal rates (greater than 95%). The optimal pH was around neutrality. Results suggested testing whether mixing the two wastewater at different rates could result in similar decontamination effects. pH neutrality was again the optimal condition. A further test at industrial scale was carried out by using a treatment plant specially assembled for the purpose. The study showed as the approach allowed to: 1) achieve a final supernatant to be reused within the recycling panel process; 2) avoid the use of lab-made high-grade solutions to modify pH; 3) minimize the production of waste (less than 60%) avoiding costs for the final out-side treatment and disposal
PEO coating containing copper: A promising anticorrosive and antifouling coating for seawater application of AA 7075
No full textMetal products in seawater have to face two important phenomena: corrosion and fouling. Corrosion representsa serious issue that can eventually compromise the integrity of the product. Biofouling, defined as the coloni-zation by organisms (bacteria, algae, plants, and animals) on wetted surfaces, is problematic because it increasesweight and consequently fuel consumption in boats. Moreover, the two phenomena are mutually sharpening.PEO is a quite new surface treatment, which increases corrosion and wear resistance of light alloys much morethan traditional anodizing, and allows the introduction of particles into the coating. In this work, the corrosionand antifouling properties in seawater of copper containing PEO coating, produced on AA 7075, were studied.PEO coatings were produced working at high current densities and in short treatment times, and the particleswere incorporated into the coatings by simple addition to the electrolyte. PEO coatings were also used as pos-sible substrate for commercial painting and untreated samples were tested as comparison. The obtained coatingswere characterized by SEM-EDS, XRD, and potentiodynamic tests. Corrosion and antifouling properties wereevaluatedin situthrough immersion of several samples in seawater for 4 weeks, intermediate collections andanalyses each week with stereomicroscope and SEM observations. The results showed that the PEO coatedsamples containing copper powder exhibited antifouling effect. The use of PEO coating as substrate for paintingcan improve performance both against corrosion and fouling, in presence of defects or damages in the paint
Microstructural and corrosion properties of particles-containing PEO coatings
No full textThe Plasma Electrolytic Oxidation treatment (PEO, sometimes also called MAO, Micro Arc Oxidation) has recently attracted great attention due to its capability to create a thick and adherent coating with excellent corrosion and wear resistance. Some of the main characteristics of PEO coatings are the high porosity of the outer layer and the possibility to incorporate directly into the coating particles that are dispersed into the electrolyte. This work will describe the results obtained by inserting metallic and non-metallic particles in PEO coatings produced on magnesium and aluminum alloys. In particular, nano-particles of graphite have been inserted in order to improve the wear resistance and metal particles (copper or silver) in order to give to the samples bactericidal, fungicidal or antifouling properties
Microstructural and corrosion properties of particles-containing PEO coatings
No full textThe Plasma Electrolytic Oxidation treatment (PEO, sometimes also called MAO, Micro Arc Oxidation) has recently attracted great attention due to its capability to create a thick and adherent coating with excellent corrosion and wear resistance. Some of the main characteristics of PEO coatings are the high porosity of the outer layer and the possibility to incorporate directly into the coating particles that are dispersed into the electrolyte. This work will describe the results obtained by inserting metallic and non-metallic particles in PEO coatings produced on magnesium and aluminum alloys. In particular, nano-particles of graphite have been inserted in order to improve the wear resistance and metal particles (copper or silver) in order to give to the samples bactericidal, fungicidal or antifouling propertie
Pearl formation associated with gymnophallid metacercariae in Mytilus galloprovincialis from the Northwestern Adriatic coast: Preliminary observations
No full textGymnophallids of the genus Parvatrema are small trematodes infecting waterbirds in their adult stage. Several species of clams and mussels have been found to act as first and second intermediate hosts, in which the trematode larval stages induce the formation of pearls. In this study, a wild population of Mytilus galloprovincialis was sampled along the Northwestern coast of the Adriatic Sea to evaluate the origin and extent of visible pearls. Parasitological investigations, including morphological and molecular analyses, and histopathology were carried out on a representative sample of mussels (n = 158) from June to September 2021. The overall prevalence of infection reached 75.3 %, and the intensity of infection ranged from a few trematodes to thousands per mussel, mostly occurring in the mantle and surrounded by variable numbers of conchiolin layers. Morphological studies allowed classification of the metacercariae as belonging to the genus Parvatrema, and the pairwise comparison of the obtained sequences, encompassing the internal transcribed spacer (ITS) region, revealed a genetic similarity (96.8 %) to Parvatrema duboisi. However, the phylogenetic analysis demonstrated the independent clustering of the obtained ITS sequences compared to other available Parvatrema species. For the relevant commercial impact that pearl formation may have on farmed mussels, ecological and epidemiological aspects of this infection would deserve further investigation in the area
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
Parvatrema sp. (Digenea: Gymnophallidae) in natural populations of Mytilus galloprovincialis from North Western Adriatic Coast.
No full textIntroduction: Parvatrema (Gymnophallidae) is a trematode infecting waterfowl at their adult stage and several species of clams and mussels in larval stages. Mytilus galloprovincialis is a widespread bivalve in the Adriatic Sea, both in natural and farmed populations. Recently, Parvatrema sp. was detected in M. galloprovincialis in a lagoon of Croatia and its presence was associated with the decline of the host population.
Methods: After the presence of visible pearls was reported in a natural population of M. galloprovincialis along the Northwestern coast of the Adriatic Sea, samples were collected in seven localities between June 2020-September 2021 to evaluate the etiology of the finding. Parasitological investigations, including morphological and molecular analyses, and histopathology were carried out on infected mussels.
Results: Metacercariae of the genus Parvatrema were morphologically identified in 75.3% of the examined specimens (119/158) with an interval of prevalence 0-100% among localities. The intensity of infection ranged from 1 to 3700 parasites/mussel and involved mostly the mantle, with parasites surrounded by a variable numbers of conchiolin layers. The pairwise comparison of the sequenced ITS region, revealed a 96.8% identity of our isolate with Parvatrema duboisi. The phylogenetic analysis demonstrated the independent clustering of the obtained sequences compared to other available Parvatrema species.
Conclusions: In addition to be a disease affecting mussels health, the presence of pearls implies a loss in the commercial value of the infected mussels. Several issues, such as identification of the involved parasite species, ecological and epidemiological aspects still need to be further investigated
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
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