1,720,957 research outputs found
The Fusion to Hydrogen Option in a Carbon Free Energy System
Full text linkTo address climate change and keep the global temperature increase within 1.5 degrees C above pre-industrial levels in the long term, ambitious climate policies are required. Decarbonizing all sectors of the economy requires a shift towards electrification. As a consequence, in order to generate a high amount of carbon free electricity, the share of electricity generated by solar and wind power will considerably increase in the years to come. However, the inherent intermittency and variability of both solar and wind power require actions in order to increase the resilience and the flexibility of the power systems and assure the security of supply. To this scope, dispatchable capacity and energy storage systems acting on both short and long terms, will play a pivotal role. The paper discusses various scenarios developed with the COMESE code to investigate the affordability and viability of future possible carbon-free Italian power system configurations, based on both existing and under development energy technologies. The 100% renewable generation option is compared to "nuclear scenarios" where a relevant base-load generation is provided by nuclear fusion power plants. Also, besides the conventional storage systems based on electrochemical devices and pumped hydroelectricity, the deployment of long term storage systems based on hydrogen production, storage and utilization (power-to-hydrogen-to-power, P2H2P) is also investigated. Specifically, excess generation from renewables is used to power electrolysers for hydrogen production. The affordability of this option is evaluated in contrast to the "fusion to hydrogen" strategy, where a continuous hydrogen production for long term storage is provided by fusion electricity. The study proves that the average system cost of electricity for any least-cost 100% renewable power system configuration exceeds that of the corresponding alternative scenario with base-load generation from nuclear power plants. If available, P2H2P works along with batteries as short/medium term storage with benefits on the total system costs, that slightly lowers. Neither converting the whole excess energy into hydrogen in order to avoid curtailment nor operating fusion power plants for a continuous hydrogen production are cost-effective strategies. Indeed, the high costs of the large tank system required for storing hydrogen and the low overall efficiency of the P2H2P process are the primary challenge
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
How fusion power can contribute to a fully decarbonized European power mix after 2050
No full textIn the second half of this century, the European energy mix will be very likely completely decarbonized. Two main options are available to generate carbon free electricity: either to rely on renewable energy sources only, or to integrate renewables with a new generation of nuclear power plant, e.g. fusion power plant. In the former case a large storage capacity and/or dispatchable generation are required to compensate for the variable electricity generation. The size of the necessary storage systems and dispatchable power plants can be reduced if a base-load carbon free power technology is available, such as fusion. These options are analysed in this paper with the CO.ME.S.E. (COsto MEdio del Sistema Elettrico – Electric System Average Cost) code that assesses the hourly balance between load and generation, through a simplified dispatch model and the system costs, through a stochastic economic analysis. Two sets of power generation scenarios are considered in typical North and South-Europe cases. The study gives key indications to make fusion a cost-effective ingredient of a future European decarbonized power mix
What is the risk of developing medication-related osteonecrosis in patients with extraction sockets left to heal by secondary intention? A retrospective case series study
No full textPurpose: Tooth and root extractions represent trigger factors for medication-related osteonecrosis of the jaw (MRONJ). The best healing modality for postextraction sockets is still debated. The aim of the study was to estimate the incidence of MRONJ after extractions whose sockets were left to heal by secondary intention. Methods: A retrospective case series study was performed at the Department of Odontostomatological and Maxillofacial Sciences, Sapienza University of Rome. Only patients who underwent nonsurgical extractions, healed by secondary intention, were included in the study. The following parameters were considered: age, sex, pathologies for which bisphosphonates or other drugs related to MRONJ were prescribed, any local or systemic risk factors, type of drug used, route of administration, number of extractions performed, and number of sessions required to complete the extraction program. The main outcome variable was the occurrence of MRONJ. Statistical analysis was performed with SPSS statistical software. Results: Two hundred twenty-one patients were treated from 2007 to 2020 with 639 tooth/root extractions. All patients were treated under antibiotic prophylaxis and with anesthesia without vasoconstrictors. No cases of MRONJ occurred. The mean age of patients was 68.02 ± 11.17. Most of the study sample was represented by women (201 = 90.95%) undergoing treatment for osteometabolic pathologies, most frequently postmenopausal osteoporosis. Alendronate was the most frequently prescribed drug, taken mainly orally. Most patients had local and/or systemic risk factors. Each patient had from 1 to 17 tooth/root extractions (mean = 2.87 ± 2.59) during 1 to 4 sessions (mean = 1.41 ± 0.64). Extractions mainly involved single-rooted teeth/roots, equally distributed between the maxilla and mandible. Conclusions: Secondary intention healing after nonsurgical tooth extraction does not seem to predispose to MRONJ. It can be advisable to perform extractions under antibiotic prophylaxis using anesthetics without vasoconstrictors and chlorhexidine mouth rinses in the 7 following days
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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