1,720,967 research outputs found
Granular Flow Simulation for the Design and Operation of De-manufacturing Processes and Systems
No full textProducts and material mixtures found in E-waste are highly inhomogeneous and in
continuous evolutions. In spite of this variability, state-of-the-art mechanical recycling
systems are extremely rigid, both in their design and parameter settings. This is mainly
due to the lack of knowledge-based engineering models and tools to support the design
and operation of separation processes able to capture, with an acceptable level of
confidence, all the major phenomena affecting the quality of the output, including
particle-particle interactions and impacts. In this paper, multi-body granular flow
simulation is proposed as a modeling and analysis tool able to capture the physics of
mechanical separation processes and to support process parameter design, operation
and control in industrial settings. The simulation of granular flows in waste material is
complicated by the non-smooth and discontinuous nature of the contact phenomena
between the particles, and between the particles and parts of the processing
equipment. The approach adopted in this paper, based on the recent theory of
Differential Variational Inequalities (DVI), is an alternative to the classical Discrete
Element Method (DEM), and it is suitable to handle up to millions of contacts between
particles, without decreasing integration time steps. The proposed models are validated
by experimental analysis carried out at the “De-manufacturing Pilot Plant” at ITIA-CNR.
Results show that this modeling framework can be used in practical settings to predict
the separation performance as a function of the process parameters
A computer-aided methodology for the optimization of electrostatic separation processes in recycling
Full text linkThe rapid growth of technological products has led to an increasing volume of waste electrical and electronic equipments (WEEE), which could represent a valuable source of critical raw materials. However, current mechanical separation processes for recycling are typically poorly operated, making it impossible to modify the process parameters as a function of the materials under treatment, thus resulting in untapped separation potentials. Corona electrostatic separation (CES) is one of the most popular processes for separating fine metal and nonmetal particles derived from WEEE. In order to optimize the process operating conditions (i.e., variables) for a given multi-material mixture under treatment, several technological and economical criteria should be jointly considered. This translates into a complex optimization problem that can be hardly solved by a purely experimental approach. As a result, practitioners tend to assign process parameters by few experiments based on a small material sample and to keep these parameters fixed during the process life-cycle. The use of computer experiments for parameter optimization is a mostly unexplored area in this field. In this work, a computer-aided approach is proposed to the problem of optimizing the operational parameters in CES processes. Three metamodels, developed starting from a multi-body simulation model of the process physics, are presented and compared by means of a numerical and simulation study. Our approach proves to be an effective framework to optimize the CES process performance. Furthermore, by comparing the predicted response surfaces of the metamodels, additional insight into the process behavior over the operating region is obtained
Saccharomyces cerevisiae as a model for the identification of beneficial molecules for mitochondrial diseases.
No full textMitochondrial disorders (MD) are a group of rare clinically heterogeneous conditions, due to
an impairment in the process of oxidative phosphorylation, responsible for the synthesis of ATP.
MD may manifest at any age and in virtually any organ, although brain, skeletal muscle, liver and
heart are most frequently involved because of their high-energy demand (mitochondrial encephalocardio-myopathies). Actually for these diseases no proven effective therapies exist.
For the current project we have taken advantage of specific models of MD in Saccharomyces
cerevisiae, previously characterized in our laboratory. The human pathological mutations studied
are relative to the genes MPV17, ANT1, POLG, and PANK2. The aim of the project is evaluating
the effects of thousands of chemical substance in these yeast experimental models, to identifiy
molecules with beneficial effects on specific MD or with a general positive influence on
mitochondrial functioning. For this aim we adopted an extensive genetic screening of drugs, called
Drug Drop Test, in yeast models. The identified molecules were further characterized in yeast in
order to better understand their impact on mitochondrial functionality. The confirmation of the
positive preliminary data obtained in this study could lead to new pharmacological approaches for
MD
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
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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