1,720,963 research outputs found
Three-dimensional electrodes for the electrochemical combustion of organic pollutants
No full textThe ability of a fixed bed of carbon pellets to work as anode in destroying chlorophenols (ClPhs) was verified. The applied current is able to continuously regenerate the external active sites of the carbon surface on which oxygen and organic are adsorbed. The low organic coverage degree of carbon, which can be maintained during runs, hinders phenol diffusion to the interior of the pellets: only the external pores are involved in the process. Preliminary runs are also presented at dimensional stable anodes (DSA(R)) based on Ru-Ti oxides. The results indicate that if a divided electrochemical cell is used, the behaviour of DSA(R) approaches that of Ti/SnO2 electrode: the reactant can be oxidised without accumulation of cyclic intermediates, thus limiting the toxicity of the resulting solution. (C) 2000 Elsevier Science Ltd. All rights reserved
An analysis of Copper(II) removal from low concentration acidic sulphate solutions using RVC electrodes
No full textCo-disposal of industrial wastes to obtain an inert material for environmental reclamation
No full textThe present work deals with the treatment of red mud from Eurallumina Bayer plant with gypsum, in order to obtain an inert which might be disposed without risk. The proposed process has particular concern in the local contest in which the Bayer plant is located. In fact, some power plants or fluoride production plants, that are present nearby the Eurallumina plant, might be economic sources of gypsum. Moreover, the inert material resulting from the proposed process should be disposed in the old mine sites, also present in the same area, and than re-vegetated, thus effectively contributing to an environmental reclamation of this territory. The present work compares the characteristics of effluents obtained by leaching with water, beds of either red mud coming from the thickening filters of the Bayer plant (RMF) or from the holding ponds (RMP), or their mixtures with gypsum. The results obtained up to now show that the process is able to lower pH at values near 9, which is stable to further leaching runs. Also the physical characteristics of the resulting material are enhanced, in terms of both particle size distribution and hydraulic permeability. The addition of 10% sandy soil is sufficient to give permeability in the order of 10(-4) cm/s, which is typical of sandy soil
Un manuale di procedura per normare la qualità minima degli interventi di manutenzione sull'edilizia storica diffusa
No full textEdizioni Arcadia Ricerche, VENEZIA, 199
On the performance of Ti/SnO2 and Ti/PbO2 anodes in electrochemical degradation of 2-chlorophenol for waste water treatment
No full textElectrochemical oxidation of 2-chlorophenol was studied at Ti/PbO2 and Ti/SnO2 anodes. The performance of the electrodes was evaluated in terms of faradaic yield and fraction of toxic intermediates removed during the electrolysis. Results showed that, although similar average faradaic yields were obtained using Ti/PbO2 or Ti/SnO2 anodes, the latter material is preferred because of its ;better ability to oxidise toxic compounds. An effective electrochemical treatment (eta(F) congruent to 50%) may be accomplished, in which electrolysis at Ti/SnO2 can be stopped when, in spite of a relatively high COD, only a small amount of easily biodegradable oxalic acid is present in the effluent
Performance of different electrode materials for electro-oxidation of organic pollutants in waste waters
No full text
Reticulated vitreous carbon electrode for copper(II) removal from dilute acid solutions: Effect of the dissolved oxygen
No full textReticulated vitreous carbon 45 pores per inch is adopted to deposit copper(II) from dilute solutions of 10-20 ppm to below 1 ppm. Three working potential values are tested: E = -0.4 V and E = -0.5 V, at which metal deposition is under diffusion control, and E = -0.25 V, at which the effect of O-2 reduction is limited, but deposition does not occur at its maximum rate. A theoretical model, which takes into account the reabsorption of O-2 from air, is proposed to interpret the trend of faradic yield as the metal concentration in the solution becomes lower. The behavior of the system is correctly interpreted from the model when electrolyses are performed at E = -0.4 V
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
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