1,720,966 research outputs found
Aerodynamic performance evaluation of multi inner blades savonius rotor
No full textSavonius wind turbine is the cheapest and simplest type of vertical axis wind
turbines. This turbine is being utilized in various countries due to the simplistic
design and low construction cost. However, this turbine suffers from low efficiency.
For that, this study aims to increase the performance of the Savonius wind rotor in
order to generate more useful power. In the present study, the aerodynamics
performance of the Savonius wind turbine rotor with inner blades was investigated.
The effect of number of inner blades, angle of inner blades, position of inner blades,
and distance between the inner blades were evaluated under low and normal ranges
of Tip Speed Ratio (TSR) through simulation and experimental work. A numerical
investigation was adopted using ANSYS Fluent 19.1 software in order to determine
the aerodynamic performance such as power coefficient (Cp) and torque coefficient
(Ct). The numerical investigation was performed using two and three-dimensional
simulations based on k-Ɛ/realizable turbulence model. Wind tunnel investigation
was also carried out for the best-performed Savonius rotor configuration under the
various parameters. Both simulation and experimental results were then compared
for verification. In general, the results obtained showed that the performance of the
Savonius rotor could be significantly improved by the addition of inner blades. The
maximum enhancement of Cp was 41% for the case of single inner blade installed at
120o
angle and tested at high TSR. As for the double inner blades, a maximum Cp of
13% was achieved when tested at low TSR (installed at 160o
angle). The results also
indicated that better performance of the Savonius rotor could be obtained when the
spacing of inner blade was set at 0.02 m and 0.005 m for single and double inner
blades, respectively. However, middle position of inner blades marked better
performance for most of the cases. It can conclude that a significant enhancement of
Savonius rotor performance can be achieved without high production cost and
complex design involved. This solution would be very useful for generating high
electricity in rural areas with a low cos
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
Electrokinetic-assisted phytoremediation of heavy metal in riverbank soil
No full textElectrokinetic (EK)-assisted phytoremediation is one of the environmental remediation methods that have a big potential in enhancing the ability of plant heavy metal uptake in soils. This study was conducted to investigate the difference in heavy metal composition concentration of riverbank soil and the change of soil pH between pre and post phytoremediation and EK assisted phytoremediation treatment. The selected phytoremediation plant is Dieffenbachia ‘Tropic Rain”. The phytoremediation plant treatment was fertilized with organic and chemical fertilizer while the EK phytoremediation plant was induced with EK system (a pair of EK electrodes connected
to a direct current (DC) power supply with a magnitude of 6 V/cm-1 electric field) for 4
hours/day. The soil and plant samples from pre and post treatments were analyzed using and X-ray Fluorescence Spectrometer (XRF), Scanning Electron Microscope / Energy Dispersive X-ray Spectroscopy (SEM/EDX) and Inductively Coupled Plasma Mass Spectrometer (ICP-MS). After 12 months of EK assisted phytoremediation treatment, the soil pH near the cathode increase 48.8% from pH 4.32 to pH 6.43 while in anode region the pH decrease 28% from pH 4.32 to pH 3.11. The element concentrations in cathode region for most elements of interest (Ni, Cu, Zn, As and Pb) were higher than anode and middle region with the highest is (47.3 ± 0.6) ppm Pb. The elemental concentration of Ni, Cu, Zn, As and Pb by EK assisted phytoremediation plants were slightly higher than the elements absorbed by the phytoremediation treated plants alone in the “chemical” and “organic” slots with the highest is (7.98 ± 0.68) ppb Zn. This showed that the EK assisted remediation treatment has increased the plant’s absorption during the phytoremediation process
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
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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