1,720,959 research outputs found
Modelling and Simulation of Hybrid Transformer Less Grid-tied Inverters for Dye Sensitized Photovoltaic System
No full textAbstractDye-sensitized solar cells affords a technically and economically trustworthy alternative for p –n junction photovoltaic devices which made by silicon. In divergence to the conventional photovoltaic device the task of light absorption and charge carrier transport separately functioned. Photons absorbed by a sensitizer, which is moored to the surface of a wide band semiconductor. Charge separation occurs at the interface via photo-induced electron injection from the dye into the conduction band of the solid. Charge collector collects the carriers are from the conduction band of the semiconductor. Because of broad absorption band of sensitizers it permits to yield a large fraction of sunlight. The conversion of incident photons into electric current is attained over a large spectral range from the UV region to the near IR region. Power electronics, the technology of efficiently processing electric power, plays an essential part in the integration of the dispersed generation units for good efficiency and high performance of the power system. Due to the characteristics of low cost and high efficiency, the transformer less photo voltaic grid- connected inverters have been popularized in the application of solar electric generation system in the residential market. Unfortunately, the leakage currents through the stray capacitors between the PV array and the ground are harmful. This paper presents modelling and simulation of dye sensitized solar system with hybrid transformer less inverter topologies and proved that H6 topology by using neutral point clamped (NPC)method for suppressing of leakage currents and to obtain excellent common mode voltages are the best compared to other topologies
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
Modeling and Performance Investigations of Partially Shaded Solar PV Arrays with Cell Partition Technique based Modules
Get PDFSolar photovoltaic (PV) modules consist of solar cells connected in series to provide the required output power. The solar PV system is experiencing major challenges, which are mainly due to the partial shadows on the photovoltaic modules leading to mismatching power loss and hot spot problems. Hotspots have become a major cause of PV module failure. The Cell Partition Technique (CPT) is proposed to reduce hotspots and minimize mismatch losses caused by partial shadings. Specifically, each solar PV cell (Full cell) in a solar PV module is divided or partitioned into two half cells (known as Half-Cut Cells or HC) and three equal cells (known as Tri-Cut Cells or TC) in accordance with the proposed technique. The HC and TC types of cells are connected in a strings of series-parallel connection, and bypass diode is placed in middle of the solar PV module to ensure proper operation. The primary aim of this research is to model, evaluate, and investigate the performance of solar PV arrays using new PV modules are developed based on Cell Partition Technique (PVM-CPT), such as half-cut cell modules (HCM), and tri-cut cell modules (TCM) and compared with full-sized cell modules (FCM). These PVM-CPT are connected in Series–Parallel (SP), Total-Cross-Tied (TCT), and proposed static shade dispersion based TCT reconfiguration (SD-TCTR) for the array sizes of 3x4, 4x3 and 4x4, respectively. The purpose is to select the most appropriate solar PV array configurations in terms of the highest global maximum power and thus the lowest mismatch power losses under short and narrow, short and wide, long and narrow, long and wide type of cell level partial shadings. The Matlab/Simulink software is used to simulate and analyze all of the shading cases. The results show that, when compared to conventional module configurations under different shading conditions, the proposed static SD-TCTR arrangement with TC modules (SDTCTR-TCM) exhibits the lowest mismatch power losses and the greatest improvement in array power. Corrigendum to "Modeling and Performance Investigations of Partially Shaded Solar PV Arrays with Cell Partition Technique based Modules" is published on 01/12/2022. Citation: BALARAJU, V., and Chengaiah, C. (2022). Modeling and Performance Investigations of Partially Shaded Solar PV Arrays with Cell Partition Technique based Modules. Trends in Renewable Energy, 8, 1-26. DOI: 10.17737/tre.2022.8.1.0013
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
Eradicating Poverty in India by Sun using Dye Sensitized Photovoltaic Technology
No full textAlmost all 1.6 billion people in developing countries have no access to electricity; approximately 85% of the people live in rural areas. Poor people and people in marginal areas, presently depend on natural resources such as wood, charcoal, dung etc. to provide energy for cooking and heating. By 2030, in this category is expected to rise from 2.4 to 2.6 billion people. The result will be greater local competition for traditional energy. So, the rural development can be achieved by promoting locally available renewable energy to meet the basic electricity needs. Decentralised production units are appropriate wherever locally renewable sources of energy are available. Efficient use of traditional and commercial fuels. The main focus of this paper is to present the energy management techniques and different applications of solar energy utilization for the rural people in India to eradicate the poverty in addition to this the role of youth, educationalists, researchers, scientists, politicians and bureaucrats etc. to eradicating poverty in the nation
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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