6,223 research outputs found

    Theories and models of supercapacitors with recent advancements: Impact and interpretations

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    Supercapacitors provide remarkable eco-friendly advancement in energy conversion and storage with a huge potential to control the future economy of the entire world. Currently, industries focus on the design and engineering aspects of supercapacitors with high performance (high energy), flexibility (by the use of composite polymer based electrolytes), high voltage (ionic liquid) and low cost. The paper reviews the modelling techniques like Empirical modelling, Dissipation transmission line models, Continuum models, Atomistic models, Quantum models, Simplified analytical models etc. proposed for the theoretical study of Supercapacitors and discusses their limitations in studying all the aspects of Supercapacitors. It also reviews the various software packages available for Supercapacitor(SC) modelling and discusses their advantages and disadvantages. The paper also reviews the Experimental advancements in the field of electric double layer capacitors(EDLCs), pseudo capacitors and hybrid/ asymmetric supercapacitors and discusses the commercial progress of supercapacitors as well

    The Effect of Modifications of Activated Carbon Materials on the Capacitive Performance: Surface, Microstructure, and Wettability

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    In this review, the efforts done by different research groups to enhance the performance of the electric double-layer capacitors (EDLCs), regarding the effect of the modification of activated carbon structures on the electrochemical properties, are summarized. Activated carbon materials with various porous textures, surface chemistry, and microstructure have been synthesized using several different techniques by different researchers. Micro-, meso-, and macroporous textures can be obtained through the activation/carbonization process using various activating agents. The surface chemistry of activated carbon materials can be modified via: (i) the carbonization of heteroatom-enriched compounds, (ii) post-treatment of carbon materials with reactive heteroatom sources, and (iii) activated carbon combined both with metal oxide materials dan conducting polymers to obtain composites. Intending to improve the EDLCs performance, the introduction of heteroatoms into an activated carbon matrix and composited activated carbon with either metal oxide materials or conducting polymers introduced a pseudo-capacitance effect, which is an additional contribution to the dominant double-layer capacitance. Such tricks offer high capacitance due to the presence of both electrical double layer charge storage mechanism and faradic charge transfer. The surface modification by attaching suitable heteroatoms such as phosphorus species increases the cell operating voltage, thereby improving the cell performance. To establish a detailed understanding of how one can modify the activated carbon structure regarding its porous textures, the surface chemistry, the wettability, and microstructure enable to enhance the performance of the EDLCs is discussed here in detail. This review discusses the basic key parameters which are considered to evaluate the performance of EDLCs such as cell capacitance, operating voltage, equivalent series resistance, power density, and energy density, and how these are affected by the modification of the activated carbon framework

    Bibliographics for the 983 eprints in the live archives of E-LIS : trends and status report up to 7th July 2004, based on author-self-archiving metadata

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    The priority for ideas and philosophy related to "Network Theory" have been traced back and documented by Braun(2004),and credit goes to Karinthy(1929).The IT has empowered to realise it, as the most practical phenomena and it is no more a humour. The OAI (Open Archives Initiatives)and ACIS (Academic Contributor Information System)are progressive in the direction ,which may lead to realise the "Collective Genius" at global level. Focus of present study is on Author-Self-Archiving (A-S-A)Metadata of the 983 Eprints in the Live Archives of the E-LIS (EPrints of Library and Information Science),which were approved till 7th July 2004.The A-S-A Metadata was used for librametric analysis. Self-explanatory bibliographics are illustrated.The highlights include: Conference papers (34%); highest approval, June 2004 (28%); published archives (76%);not refereed (52%); not in public domain (60%); highest self-archiving-author (De Robbio, Antonella).The Nos. of EPrints having single JITA domain specifications were: Theoretical and general aspects of libraries and information(27); Information use and sociology of information(80);Users,literacy and reading(13);Libraries as physical collections(30);Publishing and legal issues(57);Management(13);Industry, profession and education(36);Information sources, supports, channels(113) ; Information treatment for information services, Information functions and techniques (101); Technical services libraries, archives and museums(25); Housing technologies(1); Information technology and library technology(92); and Inter-domainery (395) i.e. having specifications of two or more than two JITA classes

    A Unified Shell model for Buoyancy-Driven Turbulence

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    We construct a unified shell model for stably stratified and convective turbulence. Shell model simulation of stably stratified flow in turbulent regime exhibit Bolgiano-Obukhbov (BO) scaling in which the kinetic energy spectrum varies as k11/5k^{-11/5}. However, simulation of convective turbulence shows Kolmogorov's spectrum. These results are consistent with the direct numerical simulations of Kumar {\em et al.} [Phys. Rev. E {\bf 90}, 023016 (2014)]. We also observe a dual scaling (k11/5k^{-11/5} and k5/3k^{-5/3}) for a limited range of parameters in stably stratified flow

    Author Index

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    Author Inde

    Triethanolamine–ethoxylate (TEA-EO) assisted hydrothermal synthesis of hierarchical β-MnO2nanorods: Effect of surface morphology on capacitive performance

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    Here in present paper, we are reporting a facile tri-ethanolamine-ethoxylate assisted hydrothermal synthesis of MnO2 nanorods. Structural (X-ray diffraction, Rietveld refinement), functional (Fourier Transform Infrared spectroscopy and X-ray Photoelectron Spectroscopy) and morphological (Field emission scanning electron microscope, Transmission electron microscopy) characterization conform the β-MnO2 nanostructure with a rod-like morphology and uniform thickness. The morphological variations of the nanorod thickness can be easily controlled by simply monitoring the reaction temperature. Comparative investigations of β-MnO2 samples synthesized at two different reaction temperatures (viz. 100°C and 120 °C) as a supercapacitive electrode material have been performed with the aid of different electrochemical techniques, such as cyclic voltammetry, galvanostatic charge discharge and impedance spectroscopy in different electrolytes (Li2SO4 and Na2SO4). Interestingly, the low temperature synthesized β-MnO2 nanorods sample exhibit superior electrochemical performance in 1 mol L-1 Li2SO4 electrolyte in terms of high specific capacitance (462 Fg-1 at10 mVs-1), energy density (9.72 WhKg-1), and outstanding cyclic stability (90.26 % over 2000 cycles)

    Story of the Story-Teller: A Conversation with Ramendra Kumar

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    Ramendra Kumar (Ramen) is an award-winning writer, storyteller and inspirational speaker with 42 books to his name.  Ramen’s writings have been published by many of the leading publishers in the county and translated into 30 languages. They have found a place in several textbooks and anthologies. He has written across all genres ranging from picture books to adult fiction, satire, poetry, travelogues, biographies and on issues related to parenting and relationships. He has been invited to literary festivals held in Denmark, Greece, Sharjah, Sri Lanka as well Indian events including the prestigious Jaipur Litfest to conduct storytelling sessions and creative writing workshops. He has also been empanelled by Pearson India Education Services as well as several schools to conduct workshops. He was nominated as a Jury Member for the Best Children’s Author Category of The Times of India’s ‘Women AutHer’ Awards 2020. Many of his stories have been showcased by popular audio streaming, apps both within and outside the country, such as Spotify, Gaatha, Talking Stories Radio – London et al. An Engineer & an MBA, Ramen was serving as the General Manager (Corporate Communications), SAIL, Rourkela Steel Plant, when he took Voluntary Retirement to pursue his passion, in August 2020. To know more about the writer, you can visit his website www.ramendra.in & his page on Wikipedia.  Dr. Sagar Kumar Sharma interviews the author and unfolds the pages of his life. &nbsp

    NOTICE!!! This person (known as Ashwin Kumar) plagiarized the text titled: "Using phenomenological research methods in qualitative health research"

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    EDITORIAL NOTICE: 1. This publication has been removed due to detected plagiarism by the editorial. 2. If you have cited, you MUST UPDATE your reference with the following original article: Wojnar, Danuta, and Kristen Swanson. “Phenomenology An Exploration”. Journal of holistic nursing : official journal of the American Holistic Nurses’ Association 25 (01 October 2007): 172-80; discussion 181. https://doi.org/10.1177/0898010106295172.     _________________________________________  3. Submitter's Profile Record (the thief, the plagiariser): Name: Ashwin KumarURL: http://www.freewebs.com/ak2146Affiliation: University of Western Sydney, Australia.Country: AustraliaBio Statement:Dr. Ashwin Kumar,PO Box 571,Toongabbie,Sydney,Australia, NSW, 2146.Homepage: http://www.freewebs.com/ak2146Email: [email protected] [email protected]: 0432-622-147Skype Internet Phone ID: ak2146 Dr. Ashwin Kumar (BA, MA (Distinction), PhD) is an academic researcher whose research interests and areas of expertise include: Complementary and alternative medicine (CAM), ageing and social gerontology, sociology, social anthropology, sociology of care, public health, health promotion, Indigenous health, migrant and refugee health, disability and chronic illness. Ashwin is the author of 8 books and numerous academic journal articles in the field of public health, health sociology and anthropology of health and illness. His books: The Lived Experience of Caring; The Lived Experience of Ageing; The Lived Experience of Using Complementary and Alternative Medicine; Doing Sociology; The Basics of Sociology; Plain English Writing; Research and Writing Skills and Writing Effective Essays are available at:  http://www.amazon.com/s/ref=ntt_athr_dp_sr_1?_encoding=UTF8&sort=relevancerank&search-alias=books&field-author=PhD.%20Ashwin%20Kumar  My homepage: http://www.freewebs.com/ak2146  ________________________________________

    Chitosan in electrochemical (bio)sensors: nanostructuring and methods of synthesis

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    Chitosan (Chit) is one of the most available natural biopolymer that have been extensively studied for wide range of applications such as biomedical, drug delivery, energy, environmental remediation and food industry. In this review, we have collected and discussed research literature of recent years dealing with modification/functionalization of Chit at the nanoscale and techniques of synthesis of Chit-based materials for application in electrochemical (bio)sensors. Chit-based nanomaterials functionalization strategies and the state-of-art of their incorporation to advance electrochemical (bio)sensors in various fields of applications have been thoroughly discussed together with the most effective methods of Chit deposition (molecular imprinting, layer-by-layer, and electrodeposition) and the role of Chit in biosensing promotion

    Multivariate Quantitative Representativeness and Constituency Analysis of Ecological Observation Networks

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    Cite this code as: Kumar, J. (2023). Multivariate Quantitative Representativeness and Constituency Analysis of Ecological Observation Networks (Version 1.0) [Computer software]. https://doi.org/10.5281/zenodo.8048530 Multivariate Quantitative Representativeness and Constituency Analysis of Ecological Observation Networks Author: Jitendra (Jitu) Kumar ([email protected]), Oak Ridge National Laboratory Regional and global ecological research networks, representing coordinated and standardized as well as adhoc networks of observation sites, provide valuable observations necessary for ecological modeling and synthesis studies. Studies conducted across observational networks strive to scale up their results to larger areas, trying to reach conclusions that are valid throughout regional, continental, and even global scales. Network representativeness and constituency can show how well conditions at those locations represent conditions elsewhere within a larger area containing the network and can be used to help scale-up results over larger regions. Representativeness: Euclidean distance between two sites plotted in multivariate environmental space can be used as an inverse measure of multivariate similarity to quantify representativeness. Close sites in environmental space have a similar combination of environmental factors, and therefore are highly representative of each other. Constituency: For any site in the network, its Constituency represent all locations that are best represented by the multivariate environmental drivers at that site. Code Compilation: make Edit the ```makefile``` as needed for your platform. CC=gcc CFLAGS= -O3 hpea: network_representativeness.o\ utility.o (CC)(CC) (CFLAGS) *.o -lm -o network_representativeness .o: (CC)(CC) (CFLAGS) -c $< clean: \rm *.o network_representativeness Running the representativeness analysis: Usage: network_representativeness -infile input data file [ASCII] -coordsfile coordinate file name -clustfile coordinate file name [OPTIONAL -- must be used with -siteclustfile] -sitefile site data file name -siteclustfile site data file name [OPTIONAL -- must be used with -clustfile] -nsites No. of sites -minmaxfile minmax file name -outfile output file name -nrows No. of rows in input data -ncols No. of variables -details [OPTIONAL -- turn on output representativeness for each site, default is to write network representativeness and constituency only.] -help program usage help. Publications using ```network_reprentativeness``` code: Kumar, J., Coffin, A. W., Baffaut, C., Ponce-Campos, G., Witthaus, L., and Hargrove, W. W. (2023) "Quantitative Representativeness and Constituency of the Long-Term Agroecosystem Research Network, and Analysis of Complementarity with Other Existing Ecological Networks", Environmental Management (in press) M. M. T. A. Pallandt, J. Kumar, M. Mauritz, E. A. G. Schuur, A.-M. Virkkala, G. Celis, F. M. Hoffman, and M. Göckede. Representativeness assessment of the pan-arctic eddy covariance site network and optimized future enhancements. Biogeosciences, 19(3):559--583, 2022. https://doi.org/10.5194/bg-19-559-2022 J. Kumar, F. M. Hoffman, W. W. Hargrove, and N. Collier. Understanding the representativeness of FLUXNET for upscaling carbon flux from eddy covariance measurements. Earth System Science Data Discussion, 2016:1--25, August 2016. https://doi.org/10.5194/essd-2016-36.If you use this software, please cite it as below. Kumar, J. (2023). Multivariate Quantitative Representativeness and Constituency Analysis of Ecological Observation Networks (Version 1.0) [Computer software]. https://doi.org/10.5281/zenodo.804853
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