1,721,050 research outputs found
Smart grids for power quality improvement
Full text linkIn the context of an increasing penetration of Distributed Generators, Distribution System Operators of any size are facing the transition to the Smart Grid, investigating how its role will change in the future. This work will present a comprehensive analysis of how a DSO would face the Power Quality issue in the future thanks to the technologies of the smart grids.
The activities have been carried out in collaboration with the DSO of the city of Terni, namely ASM Terni S.p.A. (ASM) and its productivity unit Terni Distribuzione Elettrica (TDE) which owns and manages the distribution network in the municipality. During the work lifespan, there has been the opportunity to evaluate smart technologies and carry out grid analysis in a real environment, notably, the Medium Voltage distribution network of TDE and the living laboratory at ASM headquarters. Some activities have been totally developed within this work whilst others have been carried out in the context of some European projects that have been founded or cofounded by the Innovation and Research & Innovation actions for Energy sector established by the European Commission and involve ASM as consortiums’ partner. The consortiums of these projects have designed, produced and installed in the ASM facilities cutting-edge devices and software solutions for the distribution network and the electrical customers; this work has evaluated their contribution on the power quality.
Considering Smart Grid definition, it is important to understand what is currently Power Quality for a DSO; in this respect, the main objective of a DSO is to reduce the interruptions, secondly abnormal voltages are also an issue as well as the reduction of technical losses (i.e., increasing the energy efficiency). However, DSOs are focused on outages since it means the lack of its main services to the users, namely, electrical energy, which also dramatically affects other crucial services such as Telecommunication, heating, cooling, water, industrial processes.
Moreover, the Italian DSOs, which have been studied in this work, receive monetary incentives or have to pay penalties if the outages, recorded in a year, are less than defined objectives or more than these. Investigating on reduction of outages implies an increase of resilience of the distribution network, as the ability of a DSO to promptly react when a foreseen event and rapidly restore the network to the normal status.
The reduction of outages are investigated in this work considering contributions on the network development plans and on real time operations. Therefore, in a first stage, the analysis of a component widely installed in the Italian distribution networks has been carried out; notably thermal analysis of MV cable and joint is performed in order to investigate on the anomalous number of faults on this component that have been recorded in summer during last years.
Moreover, the distribution network of TDE has been analyzed with a Resilience assessment software and its related procedures for improving and validating the development plan of the distribution network. The homemade software, developed during this work lifespan, can be used for any networks and the resilience can be assessed for any type of treats.
The last stage consists of theoretical evaluations and demonstration activities of innovative solutions that could help the DSO to reduce congestions in the network during real time operation (i.e., to prevent and foreseen outages). The enabling tools that have been used are Real time Smart Meters installed in the networks and proper management software. In this respect, main concern of this work has been the interaction between DSO and Aggregator who manages a pool of users in the Demand Response campaigns. The evaluated mechanisms allow DSO to increase hosting capacity of the network in respect of Photovoltaic plants (PV) and Electrical Vehicles (EV). Moreover, this work presents assessment on cooperation mechanism between DSO and a rural microgrid by means of a proper ICT infrastructure.
In the context of power quality improvement thanks to the Smart Grids, further technologies have been evaluated in this work. With respect to the energy efficiency and voltage control, the support from storage systems have been studied by means of tests on the field, as well as it has been assessed the support from EV charging stations coordinate with the implementation of smart contracts leveraging on blockchain technology
Differential fertility associated with common apolipoprotein E alleles in postreproductive aged subjects.
No full textObjective: To investigate the possible impact of apolipoprotein E (APOE) polymorphisin on reproductive efficiency. Design: Population study. Setting: University Departments and a Laboratory of National Research Council. Patient(s): One hundred sixty healthy unrelated subjects of postreproductive age. Intervention(s): Peripheral blood collection and questionnaire administration. Main Outcome Measure(s): Apolipoprotem E genotypes were detected after PCR amplification and CfoI digestion; plasma total cholesterol was assayed. Result(s): The mean number of children of e *2 allele carriers (2.4) was lower than that of e *3/e *3 and e *4/e *3 subjects (3.9). The trend was similar (2.8 vs. 4.8) when the number of pregnancies was considered. Moreover, there was a clear inverse relationship between number of children and e*2-carrying genotype proportions (chi(2) for trend = 6.3). Conversely, the e*3/e*3 genotype was associated with the highest number of children and pregnancies (3.9 and 4.9, respectively), and the e*4/e*3 genotype, with intermediate values (3.7 and 4.4). Carriers of e*2 allele also showed the lowest levels of total cholesterol. Conclusion(s): The e*2 allele seems to be associated with the lowest reproductive efficiency and the e*3 allele, with the highest. The different total cholesterol levels associated with APOE genotypes could have an effect on steroidogenesis and determine as a consequence the observed differential fertility
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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