1,720,954 research outputs found
High-Throughput Screening of Promising Redox-Active Molecules with MolGAT
Full text linkRedox flow batteries (RFBs) have emerged as a promisingoptionfor large-scale energy storage, owing to their high energy density,low cost, and environmental benefits. However, the identificationof organic compounds with high redox activity, aqueous solubility,stability, and fast redox kinetics is a crucial and challenging stepin developing an RFB technology. Density functional theory-based computationalmaterials prediction and screening is a time-consuming and computationallyexpensive technique, yet it has a high success rate. To speed up thediscovery of new materials with desired properties, machine-learning-basedmodels can be trained on large data sets. Graph neural networks (GNNs)are particularly well-suited for non-Euclidean data and can modelcomplex relationships, making them ideal for accelerating the discoveryof novel materials. In this study, a GNN-based model called MolGATwas developed to predict the redox potential of organic moleculesusing molecular structures, atomic properties, and bond attributes.The model was trained on a data set of over 15,000 compounds withredox potentials ranging from -4.11 to 2.56. MolGAT outperformedother GNN variants, such as the Graph Attention Network, Graph ConvolutionNetwork, and AttentiveFP models. The trained model was used to screena vast chemical data set comprising 581,014 molecules, namely OMDB,QM9, ZINC, CHEMBL, and DELANEY, and identified 23,467 potential redox-activecompounds for use in redox flow batteries. Of those, 20,716 moleculeswere identified as potential catholytes with predicted redox potentialsup to 2.87 V, while 2,751 molecules were deemed potential anolyteswith predicted redox potentials as low as -2.88 V. This workdemonstrates the capabilities of graph neural networks in condensedmatter physics and materials science to screen promising redox-activespecies for further electronic structure calculations and experimentaltesting
Study of Photoinduced Ferromagnetism in Diluted Magnetic Semiconductor (Ga,Mn)As
No full textEffects of photo-excitation and spin wave scattering on magnetism of the diluted
magnetic semiconductor (DMS) (Ga,Mn)As is theoretically studied. The exchange
coupling energy between Mn+2 spins local moments is computed starting with the
zeeman energy. Its equivalence with the Rudermann-Kittel-Kasuya-Yosida (RKKY)
exchange energy which is known to have an oscillatory characteristics and contributing to an indirect exchange, expressed based on the Zener model is described. This
energy is shown to rise to maximum near/at resonance. Green function formalism
is used to find expression for ferromagnetic transition temperature TC, magnetization and magnetic specific heat Cmag starting with a model Hamiltonian consisting
of magnons, photons and an interaction of magnons with photons. TC is indicated
for zero impurity concentration, x = 0. Unusual upturn in magnetization and negative magnon specific heat are observed at very low temperature values for larger
magnon-photon coupling constant fi, in which an increase in this coupling is found
to decrease C
mag, and enhance the magnetization and the ferromagnetic ordering.
There is no observed effect of spin wave scattering on Cmag at lower temperatures
which, however, is found to rise faster exceeding scattering absence as temperature
increases. Exchange coupling energy Jnm, magnetization M(T)=M(0), ferromagnetic
transition temperature TC and magnon specific heat capacity Cmag are plotted and
compared with available experimental observations
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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