1,720,957 research outputs found
Screening of 18 species for digestate phytodepuration.
No full textThis experiment assesses the aptitude of 18 species
in treating the digestate liquid fraction (DLF) in a floating
wetland treatment system. The pilot system was created in NE
Italy in 2010 and consists of a surface-flow system with 180
floating elements (Tech-IA®) vegetated with ten halophytes
and eight other wetland species. The species were transplanted
in July 2011 in basins filled with different proportions of DLF/
water (DLF/w); periodic increasing of the DLF/w ratio was
imposed after transplanting, reaching the worst conditions for
plants in summer 2012 (highest EC value 7.3 mS cm/L and
NH4-N content 225 mg/L). It emerged that only Cynodon
dactylon, Typha latifolia, Elytrigia atherica, Halimione
portulacoides, Salicornia fruticosa, Artemisia caerulescens,
Spartina maritima and Puccinellia palustris were able to
survive under the system conditions. Halophytes showed
higher dry matter production than other plants. The best root
development (up to 40-cm depth) was recorded for
Calamagrostis epigejos, Phragmites australis, T. latifolia
and Juncus maritimus. The highest nitrogen (10–15 g/m2)
and phosphorus (1–4 g/m2 ) uptakes were obtained with
P. palustris, Iris pseudacorus and Aster tripolium. In conclusion,
two halophytes, P. palustris and E. atherica, present the
highest potential to be used to treat DLF in floating wetlands
Temperature influence on nitrogen removal in a hybrid constructed wetland system in Northern Italy.
No full textThe objective of this research was to investigate the efficiency and seasonal performance of a full-scale
hybrid constructed wetland system (HCW) in reducing total nitrogen (TN), ammonia nitrogen (NH4-N)
and nitrate nitrogen (NO3-N). HCW with a total area of about 130 m2 and hydraulic load of 2 m3/day was
composed of three subsurface
flow vertical systems (VF), working in parallel and one horizontal (HF)
connected in series. The system was loaded daily with synthetic wastewater having an average
concentration of TN of 250 mg/L (about 125 mg/L of NH4-N and 125 mg/L of NO3-N). Water samples were
collected and analyzed from May to July 2011 and from January 2012 to July 2012. Variations were
observed in nutrient removal performance related to temperature.
During the whole monitoring period median reduction efficiency (RE) in the HCW was TN 95%, NH4-N
95% and NO3-N 93%, although three sub-periods characterized by different performances have been
observed. During the
first period (from May to July 2011) the RE was positive for the three nitrogen forms
considered, whereas from January to the end of March 2012 the RE was lower, particularly for TN and
NO3-N. From April 2012, when the temperature rose above 14.8 C, there was an increase in the
performance that reached the 2011 values.
Internal production of NO3-N was observed, mainly in the VF systems between January and March
2012. The median removals of mass pollutants per m2 of HCW per day were TN 3.1 g/m2/d, NH4-N 1.5 g/
m2/d, NO3-N 1.5 g/m2/d. Segmented regression analysis identified a breakpoint at 14.2 C for wastewater
temperature that caused variations in TN and NO3-N concentration reduction performances. According to
this approach the abatement was always positively correlated with temperature, but different regression
slopes were obtained below and above the breakpoint. In particular, with lower temperature the
abatement of NO3-N and TN increased by 1.7 and 2.0% per C of temperature increase; with temperature
higher than 14.2 C the increase in abatement due to increased temperature was sharper, especially for
NO3-N
Assessment of reed beds yield for biomass energy production in the “Valli del Mincio” Natural Reserve.
No full text
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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