177,073 research outputs found
Coagulants removal and recovery from water clarifier sludge
No full textSeveral million tons per year of water clarifier sludge are produced in Europe, with forecasts of the figure doubling by the next decade. End disposal of reference sludge is mainly based on controlled landfilling, after conditioning to minimise the volume of solids. The conditioning operation is carried-out in acidic or alkaline media, thus also allowing for coagulants recovery (AI, Fe species). The quality of the chemicals recovered may not be sufficient to justify their reuse, e.g., to water clarification operations.
With the aim of improving the purity of coagulants recovered, a new ion exchange process for selective removal, separation and recovery of Al(III) and Fe(III) species from the clarifier sludge is presented. The IERAL (Ion Exchange Recovery of Aluminium) process is based on the use of a commercial weak electrolyte carboxylate resin (Purolite C106, from Purolite Co., UK), allowing for the removal of metals from the clarifier sludge acidic leachate (pH 3.5), followed by selective separation and recovery of the aluminium and ferric species during the resin regeneration step.
Together with the performance of a fully automated 50 L/d pilot plant, this paper reports the basic principles of the process
Procedimento per il recupero del principio coagulante dai fanghi di chiarificazione delle acque naturali e reflue
No full textAppropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Selective recovery of coagulants from water clarifier sludge by the use of fibrous ion exchangers
No full textA new technology for removal and recovery of coagulants from water clarifier sludge has been optimized at laboratory scale pilot plant level. The process is based on the use fibrous exchangers showing good kinetic and thermodynamic performance toward coagulant species (Al, Fe) present in the acidic leachate (pH 3.5) from water clarifier sludge. The innovation allows for the solution of the environmental problem related to clarifier sludge disposal (residual solids after metals leaching are safely applied to land), and quantitative recovery of coagulants to the water potabilisation operations.
Process optimisation, by using real clarifier sludge from the Sinni River Water Works (Apulian Water Authority, S.E. Italy), was carried-out and results are illustrated in the paper. A commercial weak cation fibrous exchanger (Fiban K4) with carboxylate functionality, selectively removed aluminium and ferric species in "moving bed" unit operations with the resin re-circulating through the stationary exhaustion and regeneration baths. Resin regeneration was efficiently carried-out by the use of 0.4M NaOH solution for quantitative recovery of almost pure coagulants, ready for reuse. Together with process optimisation, the paper also reports some mechanistic indications on the fibrous resin performance toward polyvalent metal species retention at the resin functional groups
Chronic venous disorders: Correlation between visible signs, symptoms and presence of functional disease [Insuffisance veineuse chronique: Corrélation entre les signes, les symptômes et la présence d'une dysfonction valvulaire]
No full text"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Monitoring and methods to analyse the groundwater quality degradation risk in coastal karstic aquifers (Apulia, Southern Italy)
No full textA multi-methodological approach based on monitoring and spatio-temporal analysis of groundwater quality changes is proposed. The presented tools are simple, quick and cost-effective to give service to all sorts of users. The chief purpose of the monitoring network is the detection of the piezometric or potenziometric level in the aquifer. The spatial and multi-temporal analysis of usual chemical and physical data provides both an assessment of the spatial vulnerability of the aquifer to seawater intrusion, defining a salinity threshold between fresh groundwater and brackish groundwater and of the water quality trend in terms of salinity. The evaluation of the salinity trend or of salinity-correlated parameters highlights the effects of groundwater mismanagement. The multiparameter logging provides a rapid groundwater quality classification for each well. The whole approach allows evaluating the effects of current management criteria and designing more appropriate management targets. The Apulian karstic coastal aquifers have been selected as a case study (Southern Italy). Three types of aquifer zones can be distinguished: (1) areas with low vulnerability to seawater intrusion, (2) areas with high vulnerability and (3) areas with variable vulnerability in which the salt degradation largely depends on the ability to manage the well discharge. The water quality degradation caused by seawater intrusion appears to be a combined effect of an anomalous succession of drought periods observed from about 1980 onwards and increased groundwater pumping, particularly during drought periods. A management criterion based on aquifer zones is proposed.Published299-312JCR Journalope
Criteri di gestione degli acquiferi costieri pugliesi
No full textThe quality of groundwater of Apulian carbonate aquifers is severely affected by salt quality degradation due to seawater intrusion which reduces the availability of high quality groundwater. To reduce these risks, some regional regulations were defined from seventies with the purpose to control the number of wells, the location and the authorised well discharge. The practical effects of these management criteria, the temporal and spatial trend of recharge, groundwater quality and seawater intrusion effects are discussed. Proposals for new management criteria are defined.PublishedaZORESope
Therapeutic Options and Patterns of Prescription in Chronic Venous Disorders: Results of a 3-Year Survey in Italy
No full textAbstractObjectivesTo assess self-management of chronic venous disorders (CVDs) in a selected Italian population and the pattern of prescription by selected Italian phlebologists.DesignCross-sectional study carried out between 2003 and 2005.MaterialsNon-random, transverse sample of men and women recruited by advertising.MethodsAssessment of therapeutic habits of respondents, treatment advice given by phlebologists related to socio-demographic variables and severity of the disease. Multivariate odds ratios for sex, age, class, region, family history and severity of the disease.ResultsWomen undergo CVD therapy more than men (odds ratio (OR): 2.37 for medical treatment; 1.29 for surgical treatment and 5.72 for sclerotherapy). Young people prefer drug treatment to compression stockings. Drug therapy for CVD is 1.5 times more likely in southern Italian respondents, as is compression stockings (OR: 1.91). Surgical therapy is more frequent in Northern Italy (OR for Central Italy: 0.79; Southern Italy and Islands: 0.76). Family history of CVD leads people to early treatment of symptoms.ConclusionsThis study provides insight into self-medication of CVD in Italy and the prescribing patterns of Italian phlebologists in the treatment of CVD. It shows that the population interviewed is able to practise responsible self-medication of their CVD problems
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
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