1,721,058 research outputs found
Living Plant-Hybrid Generators for Multidirectional Wind Energy Conversion
Get PDFThe largest existing biological interface, the surface of living plants, as it stands is capable of converting mechanical energy into electricity based on a combination of contact electrification and electrostatic induction on the plant surface and its inner tissue. Herein, the first design strategies are reported for living plant-based wind energy harvesting systems that use this effect and that are capable of harvesting simultaneously from multiple leaves of a single plant to upscale the energy output. This is the first study under outdoor-relevant conditions in a controlled test environment that relates plant-based energy conversion to wind speed and wind direction as well as parameters such as the environmental humidity. Increasing the wind speed not only leads to higher power but also low winds of 2 m s(-1) and less can be converted into storable electricity. The plant-hybrid generators are moreover capable of converting wind from multiple directions by exploiting the naturally multiplex leaf orientations and the plants can directly power light-emitting diodes (LEDs) and a digital thermometer. The results draw attention to the opportunity to obtain living plant-hybrid generators, e.g., for applications in constituting environmental sensor networks
Biohybrid generators based on living plants and artificial leaves: influence of leaf motion and real wind outdoor energy harvesting
Get PDFPlants translate wind energy into leaf fluttering and branch motion by reversible tissue deformation. Simultaneously, the outermost structure of the plant, i.e. the dielectric cuticula, and the inner ion-conductive tissue can be used to convert mechanical vibration energy, such as that produced during fluttering in the wind, into electricity by surface contact electrification and electrostatic induction. Constraining a tailored artificial leaf to a plant leaf can enhance oscillations and transient mechanical contacts and thereby increase the electricity outcome. We have studied the effects of wind-induced mechanical interactions between the leaf of a plant (Rhododendron) and a flexible silicone elastomer-based artificial leaf fixed at the petiole on power output and whether performance can be further tuned by altering the vibrational behavior of the artificial leaf. The latter is achieved by modifying a concentrated mass at the tip of the artificial leaf and observing plant-generated current and voltage signals under air flow. In this configuration, the plant-hybrid wind-energy converters can directly power light-emitting diodes and a temperature sensor. Detailed output analysis has revealed that, under all conditions, an increase in wind speed leads to nearly linearly increased voltages and currents. Accordingly, the cumulative sum energy reaches its highest values at the highest wind speed and resulting oscillations of the plant-artificial leaf system. The mass at the tip can, in most cases, be used to increase the voltage amplitude and frequency. Nevertheless, this behavior was found to depend on the individual configuration of the system, such as the leaf morphology. Analysis of these factors under controlled conditions is crucial for optimizing systems meant to operate in unstructured outdoor scenarios. We have established, in a first approach, that the artificial leaf-plant hybrid generator is capable of autonomously generating electricity outdoors under real outdoor wind conditions, even at a low average wind speed of only 1.9 m s(-1)
Biohybrid Wind Energy Generators Based on Living Plants
No full textBiohybrid approaches harnessing living systems and biological tissue to accumulate electrical energy have potential to contribute green and autonomous power sources. We recently discovered that the cuticle-cellular tissue bilayer in higher plant leaves functions as an integrated triboelectric generator that is capable of converting mechanical stimuli into electricity. In this manner, living plants can be used to transducemechanical energy such as wind energy into electricity. Here, we report on two essential components of the plant-biohybrid energy harvesting prototypes studied in Ficus microcarpa and Rhododendron yakushimanum, which are 1) the electrodes at the plant tissue that are used to harvest the electrical signals and 2) the wind-induced mechanical interactions between plants and an artificial leaf based on a silicone rubber/indium tin oxide/polyethylene terephthalate multilayer that is installed at the plant’s leaf to enhance the power output. We show moreover that in the same manner a Nerium oleander plant can directly power 50 LEDs and a digital thermometer under wind excitation. The results reveal design strategies for biohybrid energy harvesters on the basis of living plants that could become autonomous energy sources for sensor networks and environmental monitoring
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
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
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