1,721,096 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
Synthesis and Characterisation of Carbon Nanotubes Prepared Using Pulsed Laser Ablation Deposition Technique
Full text linkCarbon nanotubes (CNTs) has been the focus of a virtual storm research, both to better understand its unique properties and to harness its potential in commercial applications such as hydrogen storage, atomic force microscopy probe, microelectronic transistor, electrical field emitter of flat panel display. There are two main premises in this research project; the first premise was to synthesis the CNTs via Pulsed Laser Ablation Deposition (PLAD) technique, and the second premise was to study the effect of Fe2O3 as catalyst on the magnetic properties of the deposited materials.
This work reports the formation of carbon web-like nano structure synthesized in a T-shape stainless steel chamber. ND:YAG laser with 532nm wavelength and 10.24 W power was used to ablate the target of graphite and catalyst. Fe2O3 and NiO were mixed separately as the catalyst with graphite (carbon) to form the target. The vacuum level was kept at 5 mtorr with argon gas flowing from bottom of the chamber. The soot that was deposited on the glass substrate was then characterized using X-Ray Diffraction (XRD), Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM), EDX and Vibrating Sample Magnetometer (VSM).
The SEM images confirm a web-like structure formed after the ablation. The graphite target that was ablated with laser does not form web-like structure. However, when NiO or Fe2O3 were introduced as the oxide catalysts, the web-like structure was formed successfully. The TEM pictures proved the web-like structure is the carbon nanotubes. Magnetic characterization via VSM was conducted after the CNTs structure was confirmed. From the magnetic characterization, we found that CNTs behaves as non-magnetic material due to the absence of the hysteresis curve. When it was filled with Fe2O3, the magnetic properties enhanced tremendously. It was also concluded that these Fe2O3 nano particles magnetic materials were trapped in the tubes. The CNTs acted as nano-wires and were able to induce the magnetization of the magnetic particles
Parallel evolving morphology, magnetic properties and their relationships in Ni₀.₅Zn₀.₅Fe₂O4
Full text linkFor more than seven past decades, the ferrite research literature has only very superficially dealt with the question of how the evolving microstructure of a ferrite material relates to its accompanying, resultant magnetic properties. The literature has only covered in great detail the answers for the case of ferrite materials obtained from final sintering. Thus, this work was a fresh attempt to critically track the evolution of magnetic properties parallel to the microstructural changes in bulk Ni0.5Zn0.5Fe2O4 samples and to relate the properties to the changes wherever possible. The study was divided into five parts. The first part involved two variables (milling time and ball to powder weight ratio (BPR)) of a mechanical alloying process where they were varied in order to study their effect on the magnetic properties of the material. The alloyed powders were used as starting powders for the rest of the research work. In the second part, parallel sintering of a number of samples was carried out with sintering temperatures of 500 to 1400oC, subjecting one sample to only one particular sintering temperature. This was a multi-sample sintering process with 100oC increments. The third part dealt with higher-precision multi-sample sintering of several samples with sintering temperatures of 800 to 1000oC with much smaller increments of 25oC. The fourth part involved studies of the effect of soaking time on microstructural evolution and its influence on the magnetic properties. The last part carried out was similar to the second part (multi-sample), but it was run more carefully and critically with only one sample (single-sample) being subjected to various ascending sintering temperatures from 500 to 1400oC.
The results from first-part on the mechanical alloying parameters variation showed that there were no significant trends to relate the milling time and BPR with the permeability and losses of the material studied. After the samples were sintered at 1150oC, all the effects of the alloying process seemed to diminish. The results from the multi-sample sintering with the nanosized starting powders subjected to various sintering temperatures showed a clear development trend of the phase, morphology and magnetic properties of the samples. It is very interesting that the results revealed a critical region of sintering temperature for the development of magnetic properties which was observed at 800oC and 900oC with the sigmoid B-H curve shape taken to indicate a strong magnetic order. For the first time, this work has reported the evolution of the B-H hysteresis loops associated with the changes of magnetic states from paramagnetism to moderate ferromagnetism to strong ferromagnetism with microstructural changes. The results of the higher precision third part on the relationship between ordered magnetism and the microstructure of the samples revealed a very startlingly systematic trend: a highly refined evolution trend covering a critical region of ordered magnetism which emerged and developed in step with morphological changes. Further work on the soaking time parameter was to study another possible way for the microstructure to influence the magnetic properties. The results showed a slow grain growth rate indicating a slow diffusion of atoms during the sintering process: it is believed that there was an increase in number of grain growth spots and these were the regions of mixed superparamagnetic and paramagnetic mass with ferromagnetic mass starting to dominate the samples. The last part of this work, carried out using single-sample sintering, also produced very gratifying results from the research point of view: the fascinating results from the single-sample sintering showed very systematically the evolution of microstructure-magnetic property relationships with a clarity superior to that shown by the multi-sample sintering.
Finally, after analysing the results and the observations of the work mentioned above, it is strongly believed that there are three factors found to sensitively influence the samples content of ordered magnetism –their ferrite-phase crystallinity degree, the number of grains above the critical grain size and large enough grains for domain wall accomodation. This research work has shed new light on the microstructure-magnetic properties evolution in ferrites
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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