1,721,030 research outputs found
Aqueous-Based Dye Sensitized Solar Cells: Copper Electrolytes
Get PDFNowadays, dye-sensitized solar cells (DSCs) have been a great alternative to the conventional p-n junction photovoltaic devices that convert solar energy to electrical current, especially for indoor applications. However, a DSC to be used as the power source in any indoor appliance, it should be an eco-friendly device. One of the most important components of DSCs is the electrolyte, since it plays a crucial role in the regulation of electron transfer kinetics. The most currently used electrolyte systems are the I-/I3- couple and copper or cobalt complexes dissolved in an organic solvent. The solvent is usually a nitrile based organic compound, where some of which are either toxic or of very high volatility.
In this study, we report on the use of eco-friendly aqueous electrolyte systems that contain one of three highly-charged pyridyl-based aqueous copper complexes (anionic or cationic) with hydrophilic groups such as –OHs and their use in DSCs with different commercially available organic and metal complex dyes. Additionally, these complexes bear two groups on the 6, 6’ positions for the bipyridine-based or 2, 9 for phenanthroline-based complexes that stabilize the Cu (I) state, achieving DSCs with reduced cost, improved environmental compatibility, and having promising efficiencies.
The Ru-based C106 dye sensitizer showed the best photovoltaic performance with the Cu(dmdcbpy)2]2+/1+ based electrolyte, and was further demonstrated to show a remarkable PCE value at ambient lighting for 100% aqueous-based DSCs. Under illumination from a white LED light (1000 lux) we achieved a PCE value of 6.54%
Distinguishing motor oils at higher concentration range by evaluating total fluorescence quantum yield as a novel sensing tool
No full textReducing Energy Cost for Wastewater Treatment in the Middle East: A Physio-chemical Prospective
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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
Revert spacing, electric effects and multi-component banding in periodic precipitation - by Tony Eugene Karam.
No full textThesis (M.S.)--American University of Beirut, Department of Chemistry, 2011.;"Advisor : Dr. Rabih Sultan, Professor, Department of Chemistry--Members of Committee: Dr. Houssam El-Rassy, Assistant Professor, Department of Chemistry Dr. Digambara Patra, AsIncludes bibliographical references (leaves 81-84)Periodic precipitation yields beautiful patterns that are similar to some natural self-organization structures, notably the process of rock formation in Geochemistry. In this so-called Liesegang phenomenon, an outer electrolyte diffuses through a gel med
Synthesis and investigation of organic materials with potential applications in sensing, electronics, and informatics - by Fadi Mustafa Jradi
No full textThesis (M.S.)--American University of Beirut, Dept. of Chemistry, 2010.;"Advisor : Dr. Bilal Kaafarani, Associate Professor, Chemistry--Member of Committee : Dr. Tarek Ghaddar, Associate Professor, Chemistry--Member of Committee : Dr. Digambara Patra, AssBibliography : leaves 255-264.We report the fabrication of a series of novel pyrene-based organic materials that can be utilized in different aspects of organic electronics including cation sensing, OLEDs, and information processing
Interaction of carbon nanotubes with curcumin: Effect of temperature and pH on simultaneous static and dynamic fluorescence quenching of curcumin using carbon nanotubes
No full textVariations 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
Study of diesel fuel contamination by excitation emission matrix spectral subtraction fluorescence
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