1,720,985 research outputs found
Mn-ferrite based solar thermochemical water splitting cycle: A thermodynamic evaluation
No full textBy utilizing the data obtained from the HSC Chemistry software, the thermodynamic equilibrium and efficiency analysis of the Mn-ferrite based water splitting (MFWS) cycle was conducted. All the thermodynamic calculations were performed by varying the partial pressure of O2 (PO2), thermal reduction (TH), and water splitting temperature (TL). The degree of non-stoichiometry (?) allied with the Mn-ferrite was observed to be increased as the PO2 was decreased from 10?1 to 10?5 atm and the TH was upsurged from 1500 to 2100 K. This rise in the ? resulted into a higher amount of H2 production via water splitting (WS) reaction. To achieve upper ?, elevated TH was required and hence the solar energy required to run the MFWS cycle (Q?solar-cycle) was observed to be higher. In contrast, as the TL was increased, due to the drop in the temperature gap between the TH and TL, the Q?solar-cycle was reduced. The solar-to-fuel energy conversion efficiency (?solar-to-fuel) of the MFWS cycle was observed to be maximum when the PO2 and TH were lowest and the TL was the highest. For instance, at PO2 = 10?5 atm, TH = 1500 K, and TL = 1400 K, the uppermost ?solar-to-fuel = 39.8% was attained in case of MFWS cycle which was higher than Ni-ferrite based water splitting (NFWS) cycle by 8.5%. - 2019 Elsevier LtdThis publication was made possible by the NPRP Grant ( NPRP8-370-2-154 ) from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of author(s).Scopu
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
H2 Production via ferrite based H2O splitting cycle: Solar reactor thermodynamic efficiency analysis
No full textThis study reports the thermodynamic equilibrium and efficiency analysis of the Ba-ferrite based thermochemical water splitting cycle. Attempts were made to identify the equilibrium composition associated with the thermal reduction of Ba-ferrite using HSC Chemistry software. In addition, the equations associated to the thermodynamic efficiency analysis were developed. Copyright American Institute of Chemical Engineers.This publication was made possible by the NPRP grant (NPRP8-370-2-154) from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of author(s).Scopu
Variations on the Author
Get PDF“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
Get PDFWe 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
Application of cobalt incorporated Iron oxide catalytic nanoparticles for thermochemical conversion of CO2
No full textThis investigation describes the application of the sol-gel synthesized CoxFe3?xO4 (CF) materials towards the solar thermochemical fuel production. The CF materials were derived by sol-gel method (where x was varied in the range of 0.2 to 1) and the prepared CF materials were further characterized using multiple analytical techniques. The characterization results specify formation of CF nanoparticles with phase pure composition and high SSA. A high temperature thermogravimetric analyzer (TGA) was employed to determine the redox reactivity of the CF materials towards CO2 splitting reaction. The obtained experimental findings showed that the incorporation of CO+2 into iron oxide crystal structure was advantageous to accomplish higher CO production rate via CO2 splitting. The highest amount of CO production was observed in case of CoFe2O4 (145.2 ?mol/g of CO). It was further realized that the CoFe2O4 possess better CO2 splitting ability in comparison to the Fe3O4 and CeO2. - 2019 Elsevier B.V.This publication was made possible by the NPRP grant ( NPRP8-370-2-154 ) from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of author(s).Scopu
Solar thermocatalytic conversion of CO2 using PrxSr(1?x)MnO3?? perovskites
No full textThe prime aim of this study was to examine the thermal reduction (TR) and CO2 splitting (CS) capacity of each PrxSr(1?x)MnO3?? (PSM) perovskite. A solution combustion synthesis (SCS) approach was applied for the synthesis of PSM perovskites wherein glycine was utilized as the fuel. As-synthesized PSM perovskites were first annealed up to 1000 °C in air and the calcined powder obtained was further analyzed using multiple characterization techniques. A high-temperature experimental set-up consisting of a Setaram SETSYS Evolution thermogravimetric analyzer (TGA) was developed and utilized for the examination of the SCS derived PSM perovskites towards thermochemical CO2 splitting reactions. The obtained results indicate that the lower Pr and higher Sr atomic concentrations are beneficial to achieve the maximum amounts of O2 released (nO2) and CO produced (nCO) in each thermochemical cycle. Based on the average nO2 and nCO, the Pr0.18Sr0.80Mn0.99O2.951 (PSM2) and Pr0.39Sr0.63Mn0.98O2.979 (PSM4) were identified as the best choices for the solar thermochemical conversion of CO2. When compared with the CeO2 material (which is considered as a yardstick), the average nO2 and nCO by all the PSM perovskites was considerably higher for each cycle. - 2019 Elsevier LtdThis publication was made possible by the NPRP grant ( NPRP8-370-2-154 ) from the Qatar National Research Fund (a member of Qatar Foundation). The statements made herein are solely the responsibility of author(s).Scopu
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
- …
