1,720,957 research outputs found
A review of carbon-based hybrid materials for supercapacitors
No full textSupercapacitors are gaining popularity due to their high cycling stability, power density, and fast charge and discharge rates. Researchers are exploring electrode materials, electrolytes, and separators for cost-effective energy storage systems. Advances in materials science have led to the development of hybrid nanomaterials, such as combining filamentous carbon forms with inorganic nanoparticles, to create new charge and energy transfer processes. Notable materials for electrochemical energy-storage applications include MXenes, 2D transition metal carbides, and nitrides, carbon black, carbon aerogels, activated carbon, carbon nanotubes, conducting polymers, carbon fibers, and nanofibers, and graphene, because of their thermal, electrical, and mechanical properties. Carbon materials mixed with conducting polymers, ceramics, metal oxides, transition metal oxides, metal hydroxides, transition metal sulfides, transition metal dichalcogenide, metal sulfides, carbides, nitrides, and biomass materials have received widespread attention due to their remarkable performance, eco-friendliness, cost-effectiveness, and renewability. This article explores the development of carbon-based hybrid materials for future supercapacitors, including electric double-layer capacitors, pseudocapacitors, and hybrid supercapacitors. It investigates the difficulties that influence structural design, manufacturing (electrospinning, hydrothermal/solvothermal, template-assisted synthesis, electrodeposition, electrospray, 3D printing) techniques and the latest carbon-based hybrid materials research offer practical solutions for producing high-performance, next-generation supercapacitors
Development of an Automatic PV-Battery Powered Water Irrigation System with Arduino Software for Agricultural Activities
No full textIrrigation is the artificial application of water to soil through tubes, pumps, and sprays, used when natural sources and rain are insufficient, irregular, dry, or drought-prone areas. This study proposes a drip irrigation-based solar-powered system for home grown plants and greenhouse gardens, utilizing solar energy for electricity consumption. The system is highly efficient for providing water and nutrients to crops, ensuring optimal growth, and conserving resources like water, fertilizers, energy, and crop protection products. A water tank uses an Arduino ATmega328 microprocessor to detect plant moisture levels and supply water to plants through a water motor and sensor. The system employs drip irrigation to pump water through pipes using a DC motor. The automated irrigation system utilizes a boost DC-DC switching converter, to step up input voltage and increase the output voltage, enabling remote monitoring of humidity, water, and energy consumption in flowerpots. The converter achieves significant step-up voltage gain with a suitable duty ratio and minimal voltage stress on the power switches. It is an off-grid automatic control system that operates independently of human intervention. The system utilizes a boost converter to indirectly optimize the power of two series-connected PV cells, increasing overall efficiency.©2024 Author(s). Published by Aydın Karapınar. This is an open access article under the CC-BY license.fi=vertaisarvioitu|en=peerReviewed
Development and Characterization of a New Solid Polymer Electrolyte for Supercapacitor Device
Full text linkIn this study, solid polymer electrolytes (SPEs) are based on methylcellulose (MC) used as a polymer host and sodium iodide (NaI) as a dopant. The SPE films are developed using different contents of ethyl carbonate (EC) as a plasticizer to enhance their properties via a solution casting method. The surface morphology of SPE films is shown using polarized optical microscopy (POM), which indicates the existence of amorphous patches due to the plasticizing effect of EC. The creation of a complex between MC, NaI, and EC was confirmed by Fourier transform infrared (FTIR) spectra. A tiny amount of EC applied to the MC-NaI polymer salt matrix increases the number of charge carriers and improves ionic conductivity. The ionic conductivity of the generated polymer electrolytes is examined using electrochemical impedance spectroscopy (EIS). The high-ion conducting PE of 5.06 × 10−3 S·cm−1 was found with the mixture MC + 50 wt% NaI + 10 wt% EC (room temperature). The linear speed voltammetry (LSV) test shows that the optimized polymer electrolyte can withstand decomposition up to 2.5 V. The optimized sample transmission numbers were calculated using a TNM (transference number measurement) approach, and the results show that 99% of the ions contribute to the conductivity, compared to only 1% of the electrons. A solid-state electrical double-layer capacitor (EDLC) was fabricated using the highest ion-conductive polymer electrolyte and graphene oxide (GO)-based electrodes. The galvanostatic charge-discharge (GCD) technique was performed, and the GCD graph shows the behavior of an ideal capacitor with a less Faradic process and a low ESR value. The GO-based cell’s columbic efficiency is 100%, and the system delivers the charge for a long duration. The EDLC cell demonstrates outstanding cyclability. The specific capacitance of the EDLC cell incorporated with MC + 50 wt. % NaI + 10 wt. % EC was found to be 154.66 F/g
Advances in battery technologies for next-generation energy storage systems
No full textAdvancements in energy storage systems (ESS) are important to attaining a sustainable and resilient energy future. Despite significant advancements in battery technologies, including lithium-ion, sodium-ion, and redox flow batteries, numerous problems remain. These include low energy density, thermal instability, resource scarcity, high lifecycle costs, and ineffective recycling methods. Furthermore, the complexity of connecting battery systems to the grid while maintaining operational safety creates further impediments to implementation. Recent advancements, such as hybrid energy storage systems (HESS), better battery chemistries, and intelligent modeling tools based on MATLAB/Simulink R2025b, have shown promise in terms of performance, cost reduction, and more effective energy management. However, the scalability, recyclability, and real-world applicability of these systems require further exploration. The goal here is to provide a comprehensive overview of current and emerging battery technologies, focusing on technical performance, environmental sustainability, lifecycle cost modeling, and grid compatibility. This comprises a techno-economic study that employs process-based cost modeling (PBCM) and leveled cost of storage (LCOS), a thorough examination of green battery chemistries, and system-level modeling of battery and hybrid configurations. The study seeks to provide academics and stakeholders with a comprehensive framework that considers both the innovations and limitations of current ESS technologies in the context of global decarbonization targets
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
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