1,720,954 research outputs found
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
ADVANCED ‘GREEN’ COMPOSITES BASED ON AGRICUTURAL BY-PRODUCTS
No full text97 pagesConcerns regarding environmental deterioration as well as issues regarding the sustainability of fast depleting petroleum resources used to make conventional plastics have forced the scientific community to focus on developing and manufacturing new and novel ‘green’ materials that are fully biodegradable and derived from renewable, plant-based resources. In the present study a non-edible starch, extracted from avocado (Persea americana) seed starch (AVS), a waste product of avocado processing, was developed for fabricating ‘green’ composites. AVS was crosslinked using a green crosslinker, 1,2,3,4-butane tetracarboxylic acid (BTCA), and a catalyst, sodium hypophosphite (SHP), to prepare a rigid thermoset resin with improved water resistance. Two cellulose based reinforcements, micro-fibrillated cellulose (MFC) with average diameter of 50 nm and velvet leaf (a common weed) stem derived microfibers (VLF) with average diameters of 12 μm were used to fabricate green composites. Properties of these green composites were fully characterized and compared with different compositions. In addition, advanced ‘green’ composites with excellent mechanical properties were fabricated by combining liquid crystalline cellulose (LCC) fibers with MFC blended AVS (MFC/AVS) resin. LCC fibers were modified using a combination of alkali and heat treatments to further improve their tensile strength from 1.5 GPa to over 1.9 GPa. The advanced green composites prepared by simple hand layup showed average tensile strength of 380 MPa and Young’s modulus of 25 GPa with only 40% of LCC fibers by volume. This study clearly demonstrates the potential of AVS based green composites for industrial applications such as automotive, packaging, construction and others
Optimizing dental adhesives using monomers with multiple hydrogen-bonding sites
No full textThesis (Ph.D.)--Michigan State University. Materials Science and Engineering - Doctor of Philosophy, 2025Adhesive dentistry, which entails bonding between bulk composites and dental tissues, has advanced in recent decades to improve the bonding performance of composite-based restorations. Despite these advancements, the resin-dentin interface remains vulnerable and susceptible to collagen degradation and methacrylate hydrolysis. Most recurrent caries and restoration failure occur at the adhesive interface, where poor and non-durable adhesion leads to gap formation and bond degradation due to bacterial activity, enzymatic breakdown, and hydrolysis by oral fluids. One contributing factor to this failure is the phase separation of the adhesive layer, facilitated by the presence of water or residual solvents, creating poorly polymerized hydrophilic domains. These domains increase water sorption, accelerating hydrolytic and enzymatic degradation.To understand spatial heterogeneity and phase separation in dental adhesives, we examined how adhesive composition influences phase structure; using analytical techniques such as Fourier transform infrared spectroscopy (FTIR), dynamic mechanical analysis (DMA), small-angle x-ray scattering (SAXS), and atomic force microscope (AFM) imaging. For adhesive formulations with increased 2-hydroxyethyl methacrylate (HEMA) fraction, the lower initial viscosity attributed to this co-monomer delays the onset of diffusion limitations within the reacting network, and thus allows for extensive phase separation. While HEMA has been considered a thermodynamic compatibilizer in previous studies, our work highlights the importance of kinetic (diffusion constraints) in predicting ultimate phase structure. This knowledge can inform future material design, particularly when addressing the need for robust, uniform adhesives.To address challenges associated with dental adhesive performance and heterogeneity, incorporating strong hydrogen bonding sites into the adhesive network, such as 2-ureido-4[1H]-pyrimidinone (UPy), can enhance bonding with collagen fibrils and hydroxyapatite, while improving bulk mechanical performance in the oral environment. To this end, UPy-methacrylamide monomers were synthesized using three oligomer glycol chains (Jeffamine D-230, D-400 and EDR-148) as spacers to enhance miscibility of UPy-based monomers with the other components in adhesive resins. These UPy monomers (UPy-OPG230-MMA, UPy-OPG400-MMA, UPy-OEG148-MMA) were employed as partial replacements for HEMA in experimental adhesives. Results shows that incorporating UPy-methacrylamide monomers enhances kinetics, biocompatibility, and bulk mechanical performance, with the length and chemistry of glycol chains influencing hydrogen bonding strength, particularly in wet oral conditions. Specifically, the adhesive formulation containing UPy-OPG230-MMA exhibited the strongest hydrogen bonding in aqueous condition, making it optimal for dental adhesive design. Replacing 50 wt% HEMA with UPy-OPG230-MMA significantly improved composite-dentin bonding strength in the self-etch mode, supported by scanning electron microscopy (SEM) analysis of fracture surfaces and interfacial cross-sections. These results demonstrate the potential of UPy-based monomers to strengthen the bonding interface through robust multi-dentate hydrogen bonding.Another functional unit, the catechol, has been widely studied for its strong underwater adhesive properties, including dental adhesion applications. However, catechols act as radical scavengers in free-radical photopolymerizations, slowing polymerization rates, reducing network conversion, and potentially causing cytotoxicity via leaching out of unreacted monomers. Optimizing photoinitiator systems is a straightforward strategy to counteract these effects. In this dissertation, a catechol-based monomer, catechol methacrylamide (CMA), was incorporated into a methacrylate-based adhesive resin at loading levels of 0 to 5 wt%, and multiple photoinitiating systems were explored. In addition to the conventional two-component type II photoinitiator system camphorquinone (CQ)/ethyl-4-(dimethylamino) benzoate (EDAB), a three-component type II system CQ/EDAB/diphenyliodonium hexafluorophosphate (DPIHP) and two type I photoinitiators, diphenyl(2,4,6-trimethylbenzoyl) phosphine oxide (TPO) and (2,4,6-trimethylbenzoyl) bis(4-methylphenyl)phosphine oxide (TMO), were investigated. The novel photoinitiator systems significantly enhanced reaction rates and final conversion, counteracting inhibitory effects associated with the catechol, thereby improving the biocompatibility and bonding strength. Overall, the inhibitory effects of catechol can be addressed by modifying the photoinitiator system and enhancing free radical generation, to highlight the strong potential of catechol for dental bonding applications.Description based on online resource. Title from PDF t.p. (Michigan State University Fedora Repository, viewed ).Includes bibliographical references
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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