1,721,014 research outputs found
Asphaltenes precipitation from Saskatchewan crude oils: Inter-relationships between oil-asphaltenes characteristics, precipitation behavior, and inhibitor effectiveness.
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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
A commercial pathway for evaluating the performance of a novel amine solvent blend in a mini-pilot plant for carbon capture
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Applied Science in Process Systems Engineering, University of Regina. xvi, 142 p.This study investigates the performance of a novel solvent bi-blend, 4M (2:2) AMP:1-(2HE) PRLD, for CO2 capture through absorption and desorption, providing a potential alternative to the conventional 5M Monoethanolamine (MEA). The pathway utilized to assess the performance of the amine bi-blend for commercial application involved conducting carbon capture experiments in a laboratory bench-scale mini-pilot plant. This approach aimed to validate the solvent's performance under conditions that mimic a full-scale commercial industrial CO2 capture plant. The research also addresses the urgent need for more efficient and cost-effective carbon capture solutions to combat increasing greenhouse gas emissions and global warming.
Experiments were conducted with varying feed gas compositions, with CO2 concentrations ranging from 4.5% to 30%, to simulate different industrial emission scenarios. Key performance metrics, including CO2 absorption efficiency, cyclic capacity, mass transfer rates, and energy consumption for solvent regeneration, were meticulously evaluated. For a CO2 partial pressure of 4.5%, the novel solvent blend demonstrated significant performance enhancements compared to 5M MEA. Specifically, the 4M (2:2) AMP:1-(2HE) PRLD blend exhibited an enhancement in absorption efficiency by up to 25% at a reboiler temperature of 110 °C, 41% at 100 °C, and over 700% at 90 °C. Additionally, there was a reduction in regeneration energy requirements by approximately 30% at 110 °C, 43% at 100 °C, and 84% at 90 °C. The novel blend showed robust performance across a wide range of these parameters, indicating its versatility and suitability for diverse industrial applications.
The study also revealed an average increase of 150% in the overall gas phase volumetric mass transfer coefficient (KGav) and 110% for the overall liquid-phase volumetric mass transfer coefficient (KLav). These significant improvements emphasize the novel blend's superior mass transfer performance, which is crucial for maximizing CO2 capture efficiency and column design. Parametric studies were conducted to understand the influence of various operational parameters on mass transfer performance. It was observed that the absorption efficiency and mass transfer rates were significantly influenced by CO2 loading, gas flow rate, desorption temperature and pressure. Results from this exercise showed that there is a strong positive correlation between the reboiler temperature and the efficiency as well as the overall mass transfer coefficient. It was also noted that the mass transfer was mainly controlled by the liquid phase while increasing the desorber pressure had an inverse effect on the lean amine loading which was attributed to the higher gas solubility at the higher pressure. The effect of CO2 partial pressure was also studied and a negative correlation was observed between CO2 partial pressure and the absorber efficiency, overall gas phase mass transfer coefficient.
Heat duty analysis revealed that the novel solvent blend required less energy for regeneration, thus offering a more energy-efficient solution. The specific energy consumption for the AMP-PRLD blend was found to be significantly lower than that for 5M MEA, highlighting its potential to reduce operational costs and environmental impacts. The study concludes that the novel solvent blend not only provides a more efficient CO2 capture solution but also aligns with the goals of reducing greenhouse gas emissions and achieving net-zero emissions from the indirect co-combustion of natural gas and biomass for energy generation even at relatively lower desorption temperature (100-110 °C) thus significantly contributing to energy savings.Studentye
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
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
Beyond net-zero carbon emissions in industrial processes through catalyst-aided amine solvents for the indirect co-combustion of natural gas and biomass
No full textA Thesis Submitted to the Faculty of Graduate Studies and Research In Partial Fulfillment of the Requirements for the Degree of Master of Applied Science in Process Systems Engineering, University of Regina. xv, 196 p.This thesis investigates the application of absorber catalysts developed and optimized for effective CO₂ capture in a power production process involving the indirect co-combustion of biomass and natural gas, addressing a crucial case study challenge of carbon emissions from large. By employing a novel bi-blend amine solvent system, improved by heterogeneous solid base catalysts, the study explores the synthesis of various super basic catalysts in a bid to optimize CO₂ absorption rates, solvent loading, and overall process efficiency
A series of heterogeneous catalysts which include PEI modified catalysts, K/MgO, K/MgO-CaO, and activated carbon blends, were synthesized and tested using a semi-batch apparatus. The initial CO₂ absorption rates of these catalysts were thoroughly analyzed against a non-catalytic baseline (control experiment). The results obtained revealed that catalysts such as AC Hydrothermal and K/MgO-CaO (5-35-60) significantly increased CO₂ absorption rates by up to 46% and 21%, respectively, over the baseline.
Contrarily, despite characterized by high basic strength, some PEI-modified catalysts, exhibited lower performance due to reduced surface area and electron transfer limitations. However, further analysis was conducted on the K/MgO-CaO (5-35-60) catalyst over the activated carbon catalyst considering its superior chemical, thermal and mechanical stability, as well as the ease of preparation and reduced waste. The screening of the catalysts was carried out at a gas composition of 4.5% CO2 (balance N2, an absorption temperature of 40℃ ± 2, and a gas flow rate of 200± 5 ml/min).
Additionally, extensive catalyst characterization test, including Powder X-ray Diffraction (XRD), CO₂ Temperature Programmed Desorption (TPD), and BET surface analysis, were conducted to understand how catalyst properties such as basic site strength, surface area, and pore structure influence CO₂ capture rates observed.
The environmental impact and potential cost savings of catalyst-aided carbon capture were then evaluated in a simulated power generation process, where an LCA, life cycle assessment, model was applied based on the ReCiPe methodology. From comparing traditional MEA benchmark solvent, the novel AMP-PRLD amine bi-blend, and the AMP-PRLD solvent enhanced with a K/MgO-CaO catalyst, the results demonstrated that the catalyst-enhanced system achieved superior carbon dioxide reductions across various gas compositions, underscoring its potential for net-zero emissions. Conclusively, this catalyst-solvent system provides a promising pathway for the power and energy sectors to significantly reduce emissions while enhancing cost-effectiveness and sustainability.Studentye
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