1,720,970 research outputs found
Fully Conjugated Benzyne?derived 3D Porous Organic Polymers for CO2 Capture and Separation
No full textPorous organic polymers (POPs) have gained tremendous attention owing to their chemical tunability, stability, and high surface areas. Whereas there are several examples of fully conjugated two?dimensional (2D) POPs, three?dimensional (3D) ones are rather challenging to realize in the absence of structural templates. Herein, we report the base?catalyzed direct synthesis of fully conjugated 3D POPs, named benzyne?derived polymers (BDPs), containing biphenylene and tetraphenylene moieties starting from a simple bis-benzyne precursor, which undergoes [2+2] and [2+2+2+2] cycloaddition reactions to form BDPs primarily composed of biphenylene and tetraphenylene moieties. The resulting polymers exhibited ultramicroporous structures with surface areas up to 544 m2 g?1 and very high CO2/N2 selectivities
Kullanılmış kayganlaştırıcı yağların manyetik nanoparçacıklar ve kostik soda kullanılarak geri kazanılması
No full textCataloged from PDF version of article.Includes bibliographical references (leaves 1-8).Oils are one of the mostly used lubricants in industry. Chemical oxidation, however, causes depletion of additive materials i.e. antioxidants in lubricants and their usage life time shortens. This causes varnish and sludge problems and leaves behind tons of used oil that loses its functionality. It is reported that more than 600 tons of lubricating oil can be reclaimed from 1000 tons of used oil. One of the reclamation methods is caustic extraction, and has been known for more than 3 decades. Although caustic extraction has a very high potential because of its economic considerations, this method is not fully understood due to lack of research. We have revealed that opposite to the common belief, oxidized oils (used oils) have ester groups in contrary to carboxylic acids. Magnetic nanoparticles (Fe3O4) can be used as a catalyst for hydrolysis of various esters. We have investigated the effect and mechanism of caustic extraction in combination with magnetic iron oxide nanoparticles. Using sodium hydroxide, breaks ester bonds by forming carboxylate salts and alcohols. These carboxylate salts are transferred into water and can be removed by water. Formed alcohol groups can be trapped by drying agents like MgSO4. Further purification of reclaimed oils can be achieved using hexane or similar low molecular weight and inexpensive solvents. According to our results, properties of recovered base oils mostly compete with petroleum based and ester-based synthetic base oil properties.by Timur Ashirov
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
Carbon Dioxide Capture: Current Status and Future Prospects
Full text linkThe surge in greenhouse gas emissions, predominantly in the form of carbon dioxide (CO2) spurred by the Industrial Revolution, has surpassed the critical threshold of 400 ppm, fueling global warming, ocean acidification, and climate change. To mitigate the adverse effects of these emissions and limit the global temperature rise to below 2 °C, the ambitious target of achieving net zero emissions by 2050 was established in the Paris Agreement. Current state-of-the-art technologies, such as amine scrubbing, remain problematic owing to their high energy requirements, susceptibility to corrosion, and other operational challenges. Owing to the lack of suitable technologies coupled with escalating energy demand, there is still a significant amount of carbon dioxide being released into the atmosphere. Accordingly, there is an urgent need for the development of alternative technologies that offer high efficiency, low energy consumption, cost-effective installation, and operation. In this review, we delve into the emerging technologies poised to address these challenges, evaluating their maturity levels in comparison to existing commercially available solutions. Furthermore, we provide a brief overview of ongoing efforts aimed at commercializing these innovative technologies
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
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