1,720,958 research outputs found
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
Mechanical and Tribological Behaviour of Natural Fiber (Eulaliopsis Binata) Reinforced Polymer Composite
Get PDFEnvironmental awareness today motivates the researchers, worldwide on the studies of natural fiber reinforced polymer composite and cost effective option to synthetic fiber reinforced composites. The availability of natural fibers and ease of manufacturing have tempted researchers to try locally available inexpensive fibers and to study their feasibility of reinforcement purposes and to what extent they satisfy the required specifications of good reinforced polymer composite for different applications. With low cost and high specific mechanical properties, natural fiber represents a good renewable and biodegradable alternative to the most common synthetic reinforcement, i.e. glass fiber. Despite the interest and environmental appeal of natural fibers, there use is limited to non-bearing applications, due to their lower strength compared with synthetic fiber reinforced polymer composite. The stiffness and strength shortcomings of bio composites can be overcomed by structural configurations and better arrangement in a sense of placing the fibers in specific locations for highest strength performance. Accordingly, extensive studies on preparation and properties of polymer matrix composite (PMC) replacing the synthetic fiber with natural fiber like Jute, Sisal, Pineapple, Bamboo, Kenaf and Bagasse were carried out. These plant fibers have many advantages over glass fiber or carbon fiber like renewable, environmental friendly, low cost, lightweight and high specific mechanical performance. There are many potential natural resources, which India has in abundance. Most of it comes from agriculture or forest. Eulaliopsis Binata (EB) fiber (locally known as “sabai fiber”) is one of such fiber whose potential as a reinforcement material in the PMCs has not been studied to an extent that comparable to jute, banana, bamboo, sugarcane etc. This fiber plant belongs to “poacceae” family of plant kingdom, which is known for its good fiber quality. These plants are grown in the eastern part of India along with some Asian countries such as China, Nepal, Pakistan, Myanmar, Thailand, Philippines, and Malaysia etc. The eulaliopsis binata (EB) fiber plant is generally grown on waste lands and also contributes to the soil conservation of the inclined and waste lands. The fiber quality of this plant could be recognized by its existing applications of the fibers as rope, mats, carpets, sofa sets, wall hangings and other sophisticated, fashionable articles, which have proved its worth as a structural material with reasonably good mechanical properties. A fiber to be used as reinforcement material must possess cellulose, hemicellulose and lignin along with other constituents like carbon, which makes it lighter. This fiber structure consists of 52% cellulose, 27% hemicellulose and 17% lignin along with other constituents such as ash and moisture etc. The constituents of the fiber material conform the requirements to be used as a reinforcement material in polymer based composites for structural and other applications. In India, the EB plants are cultivated in various parts of India such as Odisha, Uttar Pradesh, Bihar, West Bengal, Punjab, Haryana and Himachal Pradesh. The availability of EB fiber in India is about 3, 50,000 tons out of which only 82,000 tons are used in paper industry. The EB fiber is provides 25% of total fiber raw material requirement of India for various applications. These plants once grown, provide yield for 10-15 years and the cost of cultivation per acre decreases with progressing years from 47.89 dollar from the 1st year to 5.44 dollar in the 12th year due to lower maintenance requirements. From the economic point of view, EB plantation is very economical with an average net return 323 dollars per annum from the degraded lands whose opportunity cost is almost zero. The cost of EB long fibers per kilogram varies between 5-8 Indian rupees. The EB plants are considered to be the “money plants” due to cheap and profitable cultivation throughout the year. Against this background, the present research work has been undertaken with an objective to explore the use of natural fiber Eulaliopsis Binata as a reinforcement material in epoxy base. The work presented in this dissertation involves investigation of three distinct problems of natural fiber composites: i. A study of favorable mechanical properties of Eulaliopsis Binata fiber in thermosetting matrix composite. ii. Investigation of weathering behavior of Eulaliopsis Binata fiber composites and its influence on the mechanical performance iii. An experimental investigation of tribological properties (abrasive and erosive) of Eulaliopsis Binata reinforced epoxy composite. To study the mechanical properties of the composite, different weight fractions of fiber have been taken. Usual hand-lay-up technique has been adopted for manufacturing the composite. To have a good compatibility between the fiber and matrix, chemical modification of fibers such as acetone,
alkali, and benzoyl-chloride and treatments has been carried out. It was found that benzoyl-chloride treated fiber composite exhibits favorable strength and stiffness in comparison to other treatments. Moisture absorption behavior of both treated and untreated fiber composite was also carried out. The moisture absorption kinetics of the composite has also been studied. The study confirms that the Fickian’s diffusion can be used to adequately describe the moisture absorption in the composite. The EB fiber epoxy composites exhibited better abrasive wear resistance properties as compared to neat epoxy. However, it is limited to twenty weight percent in comparison to thirty weight percent for strength and modulus under all tested conditions. The formation of fibrils and debonding between fiber and matrix material due to low load transfer is the main cause of reduction in fiber content for wear analysis. To study the tribo-potential of Eulaliopsis Binata fiber, solid particle erosion behavior by air jet erosion test rig have been carried out. All these tests have been carried out as per ASTM standard. The solid particle erosion test clearly indicates that the composite behavior is semi-ductile in nature. There are other fabrication techniques available like injection moulding, compression moulding and extrusion, where the volume fraction of reinforcement can be increased. In addition, there are other chemical methods by which the fiber surface modification could be carried out. This work can be further extended to those techniques. However, the results reported here can act as a starting point for both industrial designer and researchers to design and develop polymer matrix composite components using Eulaliopsis Binata fiber as reinforcement. The whole dissertation has been divided in to seven chapters to put the analysis independent of each other as far as possible. Major works on mechanical characterization, moisture absorption characteristics, abrasive and erosive wear characteristics of EB-epoxy composite is given in chapter 3, 4, 5, and 6 respectively
Moisture Absorption Behavior and its Effect on Mechanical Properties of Orange Peel Reinforced Polymer Composites
No full textIn recent years the natural fiber reinforced composites have attracted substantial importance as a potential material for numerous purposes. The attractive features of natural fibers like jute, sisal, coir and banana have been their low cost, light weights, high specific modulus, renewability and biodegradability. Natural fillers are lignocellulosic in nature. These composites are of much importance because of their non-carcinogenic and bio-degradable nature. The natural fiber composites can be very effective materials for building and construction industry and many more. However in many cases residues from traditional crops such as rice husk or sugarcane natural fibre or from the usual processing operations of timber industries do not meet the requisites of being long fibers. Hence these can be used in other forms such as particulate and short fiber reinforcements in composites. Natural fibers also attractive reinforcements for composites as these contain about 40% cellulose, 30% hemicellulose, and 15% lignin.
Keeping this in view the present work has been undertaken to develop a polymer matrix composite (epoxy resin) using orange filler particulate as reinforcement and to study its mechanical properties and environmental effects on the mechanical properties of the composites . The composites are prepared with different weight fraction of orange filler particulate. Experiments have been conducted under laboratory conditions to assess the effect of different environment such as steam, saline and natural conditions on the mechanical properties of the composites. The change in weight, volume and dimensions are studied for different environments. Shear strength of the composites was also evaluated by three point bend test as per ASTM D2245-85. Micro structural analysis was carried out to have a clear understanding of the effect of exposure to different environments on the mechanical properties of the composite samples.
Keeping this in view the present work has been under taken to develop a polymer matrix composite (epoxy resin) using orange peel particulate as reinforcement and to study its moisture absorption behavior and its effect on mechanical properties. The composites are prepared with different volume fraction (weight percent) of orange peel in particulate form
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
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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