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Use of chitosan and chitosan-derivatives to remove arsenic from aqueous solutions - a mini review
No full textArsenic removal has become a relevant concern due to the final confirmation of its behaviour as chronic
human carcinogen, corresponding to an ever-increasing contamination of water, soil and crops in many
parts of the world. Developing easily accessible removal strategies is therefore a primary environmental
matter. Chitosan and chitosan derivatives show good adsorption performances against arsenic removal
and are considered low cost products, easily obtainable. This review provides a summary of recent
advances of the application of these compounds in the area of sorption sciences for arsenate and arsenite
removal from water, focusing on equilibrium and kinetic mechanisms
Optimization of the treatment cycle of pressed-off leachate produced in a facility processing the organic fraction of municipal solid waste
No full textThe paper investigates, at a laboratory scale, the applicability of anaerobic digestion for the treatment of pressed-off leachate
produced in a biomechanical treatment plant for municipal solid waste. Batch tests show that the anaerobic process proceeds
smoothly and produces about 10,000 mL of methane per litre of treated leachate. The process is characterized by a lag
phase lasting about 30 days, and is completed in about 2 months. Chemical oxygen demand (COD) and volatile fatty acids
monitoring allows studying process kinetics that are modelled through a triple linear expression. Physical and biological
treatments are also investigated to reduce the residual organic charge of the produced digestate. The best performances are
obtained via aerobic degradation followed by assisted sedimentation. This cycle reduces the residual COD of about 85%,
and allows the correct disposal of the final waste stream
Reforming of olive mill wastewater through a Pd-membrane reactor
No full textThis work investigates the exploitation of olive mill wastewater (OMW) for producing hydrogen in a membrane reformer. Olive mill wastewater was filtered and then concentrated via distillation. The intermediate distillate (about 49 wt%) with 10,600 mg L-1 total organic carbon (TOC) was used to feed a membrane reactor consisting of a dense Pd-Ag permeator tube filled with Pt-based catalyst. The reforming tests were conducted at 450 °C in the pressure range 100-500 kPa by varying the space velocity from 2.78 × 10-3 to 8.33 × 10-3 mol h-1 g cat -1. The Pd-Ag tube selectively separated the produced hydrogen, while the retentate streamdmainly containing non-permeated hydrogen, CO2 and methanedwas collected from the shell side. Gas chromatographic analysis verified the presence of side reactions (hydrogenolysis, cracking, etc.) and the deactivation of the catalyst due to the carbon formation. The hydrogen recovery was positively affected by the pressure; its highest values (over 90%) were attained at 500 kPa, while the maximum hydrogen yield was measured at 300 kPa with a space velocity of 5.56 × 10-3 mol h-1 gcat -1. Up to 2 kg of permeated hydrogen was produced per ton of olive mill wastewate
Documenti ed immagini sull'innesto del vaiuolo vaccino in Bologna al principio del XIX secolo
No full textInnovative Parameters to Control the Efficiency of Anaerobic Digestion Process
Full text linkAnaerobic Digestion (AD) is a complex biological process resulting in the conversion of biodegradable organic
matter into biogas and mineralized material. Recently, treating waste technologies based on the AD process
have gained a great interest in the field of solid waste disposal as a method coupled with aerobic composting
process, aimed at reducing the harmful impact produced on the environment by land-filled untreated organic
waste. Moreover, the application of AD for the treatment of organic waste turns into the following further
benefits: (i) recover a renewable energy vector (i.e. biogas) as well as a solid material rich in nitrogen (i.e.
digestate); (ii) reduce the use of land to dispose waste; (iii) reduce the emissions in the atmosphere of the
gases responsible for the global warming. The present paper deals with the experimental determination of
operating parameters that are able to control the evolution of AD
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
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