1,721,379 research outputs found
Solar hydrogen from North Africa to Europe through greenstream: A simulation-based analysis of blending scenarios and production plant sizing
Full text linkBlending green hydrogen within the gas infrastructure is seen as the first move towards Europe's climate neutrality by 2050. Especially, Europe and North African have privileged role in energy cooperation sharing a woven and complex set of natural resources, knowledge, infrastructure, clear goals towards sustainable development. Developing common projects about hydrogen can mutually help both Europe and North Africa to achieve more sustainable, reliable and modern energy systems. This paper simulates the Greenstream gas corridor (connecting Libya to Italy) under increasing hydrogen blending scenarios using a transient and multi-component fluid-dynamic model of the gas transmission system. The additional compression energy required and the compressors’ operating hours are evaluated under the hypothesis that the energy content of the transported gas is maintained. The hydrogen profiles needed to generate the blends are obtained and used to optimally size a photovoltaic-powered electrolysis system, minimizing the compressed hydrogen storage. The results indicate that the additional energy costs of transporting hydrogen blends are up to 32.5% higher than natural gas transport, while negligibly impacting the overall efficiency of energy transport. The mismatch between solar hydrogen production and pipeline receiving potential highlights a challenge to be tackled to boost intersectoral integration
Servoattuatore lineare pneumatico e relativo circuito idraulico di controllo per movimentazioni controllate in posizione, velocità e accelerazione
No full textBiogas blending into the gas grid of a small municipality for the decarbonization of the heating sector
No full textThepracticeofblendingbiogasintothegasnetwork,especiallyatthedistributionlevel,offerstheopportunityto usebiogasasasubstituteoffossilgas.The‘greening’ofthegasnetworkthroughbiogasblendingwouldindeed takeadvantageoftherobustnessandextensivenessofanalreadyexistingenergyinfrastructure.Asteadystate and multi-component thermal-fluid-dynamic model of the gas network is applied to a portion of the Italian distributionnetwork.Thereceivingpotentialcapacityoftheexistinginfrastructureisassessedwithrespectto biogasinjection.Fluid-dynamicaspectsofthispracticeareconsideredandcommented.Themaximumallowable percentage ofinjectable biogas(purifiedfrom sulphurcompounds,O2 andsiloxanesbut notupgradedto biomethanebyremovingCO2)iscalculatedonanodalbasis,referringtotheactualgasnetworkconfiguration,and in agreement with the quality constraints set by the current regulation (UNI/TR 11537:2016). A major hypothesishasbeenassumedinthiswork:gasqualityrequirementsareenforcedonthenetworkasawhole(i.e., after blending the injected gas into grid) rather than at the injection point, which is instead the current prescriptionofmostoftheEUcountries.Byexploitingthequality-trackingfeatureofthemodel,theconstrainton the quality assessment at the injection point is thus relaxed and its effect on the grid gas quality has been quantified.Resultsfromthecasestudyshowshowbiogasblendingintothegasgridmayleadtoareductionon thefossilnaturalgasdependenceofupto4.7%
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
Blockade of D-1 receptors by SCH 23390 antagonizes morphine- and amphetamine-induced place preference conditioning.
No full textMorphine (0.5 mg/kg s.c.) and amphetamine (1 mg/kg s.c.) used in a two-compartment place preference test induced strong place preference when paired to the non-preferred environments. They did not modify preference under basal conditions but completely reversed morphine- and amphetamine-induced place preference. Pairing of haloperidol (0.2 mg/kg s.c.) to both environments also abolished the morphine-induced place preference
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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