1,720,967 research outputs found
Enhancing Efficiency of TCO-less Tandem Dye Sensitized Solar Cells by Architecture Optimization
No full text1:Introduction||2:Experimental section for optical and photovoltaic property||3:Fabrication and characterization of TCO-less Tandem DSSCs||4:TCO-less back contact Tandem DSSCs having extended wavelength photon harvesting||5:Conclusions and future prospectsExtensive use of fossil fuels to circumvent our current energy needs and their limited availability along with climate change due to greenhouse effect lead to the serious thinking about the logical implementation of renewable energy resources. Photovoltaic technologies enables us the direct utilization of solar energy in the form of electrical energy. The clean energy generation using renewable energy resource must be accomplished considering the cost effectiveness with existing power generating technologies. Dye sensitized solar cells (DSSCs), kind of excitonic solar cells have attained the rampant popularity among the existing solar cells due to its ease of fabrication and cost effective nature. DSSCs have achieved comparable photoconversion efficiency as that of amorphous Si solar cell and are on the verge of commercialization. Apart from focus being directed to achieve the cost effectiveness and stability, further enhancement in the power conversion efficiency is inevitable to compete with traditional silicon based solar cells. In order to enhance photoconversion efficiency, tandem DSSCs has been approached where the two different cells having complementary absorption spectra are mechanically stacked. This thesis work is directed to avoid and alter the precious transparent conductive oxide (TCO) glass being commonly used in the conventional tandem device architectures aiming towards the fabrication of photon flux efficient novel tandem DSSCs architectures in combination with near infra-red (NIR) photon harvesting novel sensitizers. To begin with this compilation, focus has been centralized on the energy thrust promoted existing and current research status for solar cells in general and next generation solar cells in particular. The trend has followed the first ever demonstrated practical solar cell from bell lab to mature Si solar cell technology. The technology enhancement pave the way for thin film solar cell research. Diverse application of solar cell for indoor and outdoor applications have necessitated the flexible solar cell research. Dye sensitized solar cells (DSSCs) possess these properties and have drawn attention due to its environmental friendly properties. Limitation to achieve high performance for DSSCs are outlined along with the discussion about the need for extending the photon harvesting window. The photoconversion efficiency of DSSCs can be increased beyond the limit of a single cell by stacking multiple DSSCs with the complementary light absorption followed by photon harvesting. Conventional series connected and mechanically stacked tandem DSSCs bearing four TCO glass plates fabricated and its functioning was verified with external power conversion efficiency of 6.28% under simulated solar irradiation. Aiming towards reduction of fabrication cost, a novel tandem device architecture was proposed by stacking top cell TCO-DSSC and TCO-less back contact bottom cell DSSCs. This TCO-less bottom-cell DSSC was consisted of flexible and protected SUS metal mesh coated with dye adsorbed nanoporous TiO2 functioning as photoanode. The model sensitizing dyes D131 and N719 were utilized as photosensitizers for top cell and bottom cell respectively. The fabricated tandem device architecture have shown the practicality in terms of increased optical transmission (around 20%) at bottom cell by avoiding the intermediate TCO glass. To enable the flexible processing and more economical tandem device architecture, bottom cell counter electrode was also replaced with flexible titanium (Ti) foil leading to the enhanced photoconversion efficiency of 7.10 % which is not only better than individual cell but the conventional mechanically stacked four TCO base tandem DSSCs also. After the demonstration of proof-of concept using model dyes for TCO-less tandem DSSCs having capability of photon harvesting mainly in the visible region of solar spectrum, effort as directed to enhance the photon harvesting window by utilizing NIR light harvesting axially ligated Si-phthalocyanine dye in the TCO-less bottom cell. Efficient photoconversion was demonstrated having photon harvesting up to 900 nm. Conventional tandem DSSCs using four TCO glass was first fabricated using this NIR dye for the bottom cell in combination with N719 for the top cell with the efficiency of 6.58%. In order to provide the flexibility to the tandem DSSCs, ITO-PET film having similar resistivity and enhanced transparency compared to ITO glass was utilized for the top cell. This flexible film has been incorporated to mechanically stack this top cell DSSC with TCO-less back contact bottom DSSCs using Ti foil as counter electrode aiming towards the flexible TCO-less tandem DSSCs architecture. This resulting flexible tandem TCO-less DSSCs exhibited enhanced optical transmission (around 30%) and external power conversion efficiency of 7.19%.九州工業大学博士学位論文 学位記番号:生工博甲第253号 学位授与年月日:平成28年3月25日平成27年
Enhancing Efficiency of TCO-less Tandem Dye Sensitized Solar Cells by Architecture Optimization
No full text九州工業大学博士学位論文（要旨）学位記番号：生工博甲第253号 学位授与年月日平成28年3月25
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
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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