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Experimental studies and thermodynamic modeling of metal-slag-refractory interactions in non-ferrous pyrometallurgical processes
No full textIn the non-ferrous pyrometallurgical processes, such as Cu/Ni making processes, the liquid phases, such as Ni alloys, matte, and slag phases exhibit complex behavior. Moreover, refractory lining materials generally react with the liquid phases, such as slag phases under extreme conditions at high temperatures in the Cu/Ni smelting and converting furnaces. Therefore, various solid and liquid solutions can be formed, and the fayalite FeOx-SiO2 slags including CaO, MgO, ZnO, and impurities can penetrate and corrode the lining refractory materials of the furnace, such as MgO-Cr2O3, MgO-Al2O3, and/or MgO-C.
In order to increase efficiency of Cu/Ni processes and save costs, it is needed to understand and predict the complex behavior of liquid phases and the corrosion behavior of refractory materials against liquid slags. Thermodynamic modeling can be used to understand the behavior of liquid phases and refractory corrosion against slag phases using thermochemical software, such as FactSage. The thermodynamic modeling is used to calculate phase equilibria based on Gibbs free energy minimization methodology. The Gibbs free energy of non-ideal solution phases can be expressed mathematically by several thermodynamic models, such as Bragg-Williams random mixing model and Modified Quasichemical Model. The parameters of models can be optimized using the Calphad methodology in order to fit calculated phase equilibria and thermodynamic properties with experimentally determined data. The thermodynamic calculations based on the optimized parameters can be used to interpret and predict the behavior of liquid phases and slag-refractory reactions.
In this doctoral thesis, the parameters of the ternary Ni-Co-C, CaO-MgO-ZnO, and MgO-ZnO-SiO2 systems were optimized using FactSage based on own experimental phase equilibria studies, as well as data from the scientific literature. The Bragg-Williams model was used for solid solutions, while the modified quasi-chemical model was used for the liquid solutions. All the optimized systems agreed well with the phase equilibria studies within the error limits of the experimental data. Moreover, the corrosion behavior of refractory materials against liquid slag was studied and interpreted using FactSage. Interfacial reactions between MgO-Cr2O3, MgO-Al2O3, and MgO-C refractories and CaO-FeOx-SiO2 slags were studied with experimental work, such as sessile drop and immersion tests. The experimental results also showed good agreement with thermodynamic calculations using FactSage.
With the new thermodynamic databases developed in this work, pyrometallurgical processes can be optimized further in the future, taking into account metal-slag-refractory interactions
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
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
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
준결정에서의 초공간 기하학과 이색적인 양자 현상
No full text학위논문(박사) - 한국과학기술원 : 물리학과, 2025.2,[xxii, 182 p. :]Quasicrystals exhibit unique physical properties distinct from conventional crystals and amorphous materials due to their aperiodic long-range atomic order. The study of these properties has required novel theoretical approaches, as traditional band-based methods rooted in periodicity cannot be applied. This dissertation introduces the concept of "hyperspace geometry," closely tied to the tiling patterns of quasicrystals, aiming to theoretically elucidate the exotic quantum phenomena that arise in various quasicrystal structures, while exploring their experimental applicability and controllability. Specifically, this dissertation addresses anomalous quantum transport, strong correlation effects over mesoscopic distances, the presence of multipolar magnetism, and pattern-dependent superconductivity, all grounded in the high-order symmetry and geometrical features of hyperspace. In addition, the existence and nature of the critical states that are driving these unique quantum phenomena are clarified, proposing methods to experimentally manipulate them. Through this, it deepens the theoretical understanding of properties of quasicrystals and presents the potential for experimental applications of quasicrystalline materials based on hyperspace geometry.한국과학기술원 :물리학과
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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