1,720,955 research outputs found
Global sensitivity analysis in ASM applications: comparison of the SRC and Extended-FAST method for a UCT-MBR model
No full textIn this study global sensitivity analysis is performed to identify influential as well as non-influential
parameters in a model of a University Cape Town Membrane Bioreactor (UCT-MBR). In
particular, the Standardised Regression Coefficients (SRC) and Extended-FAST sensitivity analysis
methods are applied. The sensitivity of model variables towards parameter variation is analysed for
CODTOT, SNH4, SNO3, SPO, and MLSS along five reactor compartments. Both methods indicate that the
parameters identified as being influential differ from section to section due to the different
processes involved. Moreover, the relevant influence of the membrane filtration parameters is
detected in the first plant section due to the influence of the recycled sludge. It is found that the
computationally less expensive SRC method is applied outside its range of applicability with R2 =
(0.3-0.6) < 0.7. Nevertheless, the ranking obtained with the SRC method for the influential
parameters is very similar to that of the Extended-FAST method, except for MLSS. However, to
obtain reliable quantitative information on variance decomposition and to detect and quantify (in
some cases considerable) interactions present among parameters the use of the computationally
more expensive Extended-FAST is found to be necessary in this case study
Modelling biological nitrogen and phosphorus removal with soluble microbial products (SMP) production-degradation processes
No full textOver the last two decades, Membrane Bioreactors (MBR) are increasingly used for wastewater
treatment. Mathematical modelling of MBR systems has played a key role in order to better explain
the effect of their peculiarities. Indeed, several MBR models have been presented in literature in
order to improve the knowledge on MBR systems: biological models, hybrid models which include
soluble microbial product (SMP) modelling, physical models able to describe the membrane fouling
and integrated models which couple the hybrid models with the physical ones.
However, among the existing MBR models only few integrated models have been developed which
take into account the existing relationship between fouling and the biological processes. Also, with
respect to modelling of biological phosphorus removal in MBR systems, due to the complexity of
the process, practical use of the models is still limited. There is a vast knowledge (and consequently
a vast amount of data) on nutrient removal for conventional activated sludge (CAS) systems but
only limited information on phosphorus removal for MBRs. Moreover, calibration of these complex
integrated models still remains the main bottleneck to their employment.
The paper presents an integrated mathematical model able to simultaneously describe biological
nutrient removal, the SMP formation/degradation and the physical removal of organics. The model
has been calibrated by using data collected in a UCT-MBR pilot plant, built at the Palermo WWTP
and fed with real wastewater, applying an innovative calibration protocol. The calibrated model
provides acceptable correspondence with experimental data
Global sensitivity analysis in wastewater treatment modelling
Get PDFGlobal sensitivity analysis (GSA) is a valuable tool to support the use of
mathematical models. GSA allows the identifcation of the effect of model and
input factor uncertainty on the model response, also considering the effect due to
the interactions among factors.
During recent years, the wastewater modelling feld has embraced the use of
GSA. Wastewater modellers have tried to transfer the knowledge and experience
from other disciplines and other water modelling felds
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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