1,720,989 research outputs found
Development of a web application for monitoring solar activity and cosmic radiation
No full textThe flux of cosmic rays (CRs) in the heliosphere is subjected to remarkable time variations caused by the 11-year cycle of solar activity. To help the study of this effect, we have developed a web application (Heliophysics Virtual Observatory) that collects real-time data on solar activity, interplanetary plasma, and charged radiation from several space missions or observatories. As we will show, our application can be used to visualize, manipulate, and download updated data on sunspots, heliospheric magnetic fields, solar wind, and neutron monitors counting rates. Data and calculations are automatically updated on daily basis. A nowcasting for the energy spectrum of CR protons near-Earth is also provided using calculations and real-time neutron monitor data as input
Assessment of additional aging on electric vehicles batteries in the framework of vehicle to building services
No full textThe energy transition implies a progressive loss in grids inertia. Energy storage systems can contribute to enhance the flexibility of electric systems, even if their penetration in the grid at the European level currently amounts to only a few percentage points of the overall generation capacity. In this framework, the use of electric vehicles (EVs) as multiple decentralized mobile energy storage when interconnected to a bidirectional charging column for performing Vehicle-to-X services is widely proposed. In this work, as pioneering approach, the additional aging of 50-kWh BEVs and 10-kWh PHEV batteries performing Vehicle-to-Building (V2B) operation is experimentally assessed in reference to a grid-connected renewable Micro-Grid (MG). A MG dynamic model including suitable stochastic real-time power management is developed to minimize i) the instantaneous grid power exchange and, ii) the PHEV power fluctuations. Simulations outcomes provide batteries State of Charge evolutions, subsequently implemented in the design of experiment to perform accelerated aging tests. Four 18,650 NMC Li-ion cells are tested over 9 equivalent years of operation. This allows to quantify the V2B additional degradation for the investigated case study. As results, State of Health (SoH) value achieves 84.8 % for the PHEV battery (compared to 95.8 % when V2B is not performed), while it stands at 92.9 % for the BEV (slightly lower than 95 % SoH for V2B absence). These outcomes could contribute to pave the way in the awareness of V2B impact on renewable-based Micro-Grids, while reducing stressful conditions on PHEV batteries that could yield to faster degradation
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
Assessment Analysis of BEV/PHEV Recharge in a Residential Micro-Grid Based on Renewable Generation
No full textTo limit the climate change, a strong evolution on stationary renewable power production and transport sector is needed. More than 34 million of Battery Electric Vehicles (BEVs) and 13 million of Plug-in Electric Vehicles (PHEV) are expected to circulate in Europe by 2030. This negatively affects distribution lines during BEV/PHEV charge, especially in densely populated areas. A possible solution to enhance BEV/PHEV penetration without impact on grid stability is represented by Micro-Grids (MGs), including renewable production, local loads, and energy storage. In this work, a residential MG composed by a Photovoltaic (PV) power generation system, a local load including BEV/PHEV charge, and a Li-ion battery energy storage system is implemented to assess and compare the impact on grid energy independence introducing BEV and PHEV charging load. Four different scenarios are simulated, considering either BEV or PHEV charge, varying the installed PV power (i.e., 3 kWp and 6 kWp) and Li-ion battery nominal capacity (10–20 kWh). The results demonstrate that, in a MG integrating 6 kWp PV and 20 kWh battery, BEV and PHEV can be daily charged by PV energy for 23% and 68% respectively. Hence, enhancing PV installed power and energy storage capacity in the future residential MGs will be needed to avoid stability issues on distribution feeders, in the view of massive BEV penetration for pursuing the limit to global warming
Energy Storage Integration into Fast Charging Stations Installed on e-Highways
No full textWith the development of electric mobility, today's population is preparing to face numerous changes in the way they move around, use vehicles and live in cities. The need to electrify transport stems from an ever-increasing need for energy efficiency and, simultaneously with the development of Renewable Energy Sources (RESs), smart distribution networks and a sustainable development model. The purpose of the work is to evaluate different energy storage alternatives for integration into Fast Charging Stations (FCS) installed on highways aiming to exploit renewable overgeneration
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