1,721,482 research outputs found
Addressing main challenges in the tertiary treatment of urban wastewater: are homogeneous photodriven AOPs the answer?
Full text linkHomogeneous photodriven advanced oxidation processes (HP-AOPs) have been increasingly investigated in past years as a possible alternative solution to conventional tertiary treatment methods of urban wastewater. Despite the encouraging results in successfully addressing some of the main challenges, such as pathogen inactivation, removal of contaminants of emerging concerns (CECs), and antibiotic resistance (AR) control, their full-scale application is still poor. In this review, the main challenges in the tertiary treatment of urban wastewater are identified and the advances of HP-AOPs in addressing such challenges are critically discussed, emphasizing the respective advantages and drawbacks, even compared to consolidated tertiary treatment methods. Differences between solar- and UV-driven HP-AOPs, acidic vs. neutral pH photo-Fenton, as well as between homogeneous and heterogeneous photodriven AOPs are also analyzed and critically discussed. An approach for selecting model pollutants (e.g., CECs, pathogens, and AR indicators) as well as to validate under realistic conditions the results achieved under controlled laboratory conditions is also recommended. The most relevant issues and gaps in the knowledge are identified and discussed. A large number of investigations available in the scientific literature strongly support the capacity of HP-AOPs to effectively address the challenges in the tertiary treatment of urban wastewater, and the time for their full-scale application is almost mature. While the UV/H2O2 process is already applied as a final step in potable water reuse treatment trains, solar photo-Fenton has been quite exhaustively and successfully investigated in the tertiary treatment of urban wastewater so far and it is expected to be implemented at full scale in raceway pond reactors. In conclusion, 10 recommendations to take into account when designing the experimental plan are provided. Hopefully, this manuscript is also useful to water professionals and managers to learn possible effective and sustainable alternatives to conventional processes
Hybrid: achieving deterministic fairness and high throughput in disk scheduling
No full textMany computer applications require moving data from/to disk devices. Since the throughput of disk devices is extremely sensitive to the locality of accesses, the disk schedulers proposed in the literature typically assume the knowledge of the disks' physical parameters (e.g. seek and rotational latency) to meet the different Quality of Service requirements. Unfortunately, the unavoidable discrepancies between the estimated and actual values of such parameters affect the service guarantees, both in terms of response time and disk bandwidth distribution
Flat Tax: European Experiences and Italian Proposals
No full textThe paper discusses the flat tax, intended as a potential comprehensive reform of personal income tax. After a presentation of the broad characteristics of the flat tax model, we extensively describe the applications of this model that have taken place so far in some countries and its impact on financial and economic indicators. The last part of the paper focuses on the Italian case, assessing the possible distributional effects of the application on Italian households' incomes of some recently presented flat tax reform proposals
Pharmaceuticals degradation and pathogens inactivation in municipal wastewater: A comparison among UVC photo-Fenton with chelating agents, UVC/H2O2 and ozonation
No full textIn this work, emerging advanced oxidation processes (AOPs), namely UVC photo-Fenton with two chelating agents at neutral pH, were compared for the first time to consolidated AOPs, namely, UVC/H2O2 and Ozonation (O3) in the degradation of three pharmaceuticals (PhCs) and pathogens inactivation, in real municipal wastewater (RMWW) at pilot scale. Conventional UVC based AOP (UVC/H2O2 at 50 mg/L of H2O2) was faster, being able to degrade 80% of the sum of PhCs in RMWW after 2.5 min, while the same treatment time was required to achieve 60% removal by photo-Fenton. 60% removal of the sum of PhCs in RMWW by O3 was achieved only after 75 min, at the highest dose investigated (0.45 g O3/ L h). The detection limit (1 CFU/100 mL) for pathogens inactivation was achieved after 120 min by O3 for E. coli, while more time was required for Enterococcus (10 CFU/100 mL after 120 min). Faster inactivation was observed for UVC/H2O2 (15 mg/L), the DL being achieved just within 5 and 10 min for E. coli and Enterococcus, respectively. Accordingly, UVC/H2O2 at 15 mg/L would be an effective solution for simultaneous PhCs removal and bacteria inactivation, showing better performance compared to O3 and UVC photo-Fenton like process
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
Fuel Price Subsidies and the control of corruption: a first approach
No full textFuel-price subsidies are pervasive and widespread around the globe. While there is by now a well-established understanding of the efficiency properties of fuel-price subsidies, there is limited empirical work on their determinants and, in particular, on the extent to which their presence (and their magnitude) is associated with countries that suffer significantly from corrupt practices. This chapter aims to explore empirically the link between fuel-price subsidies and a measure of the degree to which public power is exercised for private gain and the state is ‘captured’ by private interests (proxied here by the variable ‘control of corruption’). Using panel data over the period 1991-2008, this paper shows that in countries with relatively low level of corruption (high level of control of corruption), when corruption control increases, fuel subsidies decrease; for high level of corruption (low level of control of
corruption), increasing corruption control does have only a small effect on fuel subsidies. Interestingly, these results hold independently of the level of per capita income of a country. What this suggests is that, from a policy perspective, a prerequisite for a substantial reduction in fuel subsidies is an increase in the control of corruption, when it is already relatively high
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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