Physics - Research Publications

Permanent URI for this collection

http://10.2.3.109/handle/32116/61

Browse

Now showing 1 - 20 of 307

The Curie temperature: a key playmaker in self-regulated temperature hyperthermia
(Royal Society of Chemistry, 2023-11-13T00:00:00) Niraula, Gopal; Wu, Chengwei; Yu, Xiaogang; Malik, Sonia; Verma, Dalip Singh; Yang, Rengpeng; Zhao, Boxiong; Ding, Shuaiwen; Zhang, Wei; Sharma, Surender Kumar
The Curie temperature is an important thermo-characteristic of magnetic materials, which causes a phase transition from ferromagnetic to paramagnetic by changing the spontaneous re-arrangement of their spins (intrinsic magnetic mechanism) due to an increase in temperature. The self-control-temperature (SCT) leads to the conversion of ferro/ferrimagnetic materials to paramagnetic materials, which can extend the temperature-based applications of these materials from industrial nanotechnology to the biomedical field. In this case, magnetic induction hyperthermia (MIH) with self-control-temperature has been proposed as a physical thermo-therapeutic method for killing cancer tumors in a biologically safe environment. Specifically, the thermal source of MIH is magnetic nanoparticles (MNPs), and thus their biocompatibility and Curie temperature are two important properties, where the former is required for their clinical application, while the latter acts as a switch to automatically control the temperature of MIH. In this review, we focus on the Curie temperature of magnetic materials and provide a complete overview beginning with basic magnetism and its inevitable relation with Curie's law, theoretical prediction and experimental measurement of the Curie temperature. Furthermore, we discuss the significance, evolution from different types of alloys to ferrites and impact of the shape, size, and concentration of particles on the Curie temperature considering the proposed SCT-based MIH together with their biocompatibility. Also, we highlight the thermal efficiency of MNPs in destroying tumor cells and the significance of a low Curie temperature. Finally, the challenges, concluding remarks, and future perspectives in promoting self-control-temperature based MIH to clinical application are discussed. � 2023 The Royal Society of Chemistry.
Recent advances in 2D anode materials for Na-ion batteries from a theoretical perspective
(Taylor and Francis Ltd., 2023-11-02T00:00:00) Verma, Nidhi; Jamdagni, Pooja; Kumar, Ashok; Srivastava, Sunita; Tankeshwar, K.
Na-ion batteries (SIBs) are a promising replacement for lithium-ion batteries (LIBs) for low-cost and large-scale energy storage systems in the forthcoming years after additional in-depth examination and investigation. A significant part of the development of innovative anode materials and their in-depth understanding has come through simulations. Ab initio simulations based on density functional theory (DFT) have been proven to be a reliable, efficient, and cost-effective way to design new anode materials for SIBs. As a result of the identification of graphene, researchers and scientists were influenced to create new two-dimensional (2D) materials. On account of their distinctive physical and chemical properties, the broad expanse of surface, innovative electronic features, and charging ability of 2D materials attract much attention. Many of these characteristics are significant prerequisites for using anodes in batteries. Herein, based on recent research progress, we have reviewed the structures and electrochemical properties of 2D materials as anode for Na-ion batteries from a theoretical perspective. The effective methodologies for high-performance anode materials are provided based on the substantial literature and theoretical studies. Added to that, we have also explored the various techniques such as heterostructure, doping, defect- and strain-engineering of 2D materials for the improvement of the performance of these materials as anodes for SIBs. � 2023 Taylor & Francis Group, LLC.
Synergistic improvement in electrochemical performance of Cr-doped MoS2/CuCo2S4 binary composite for hybrid supercapacitors
(Elsevier Ltd, 2023-10-31T00:00:00) Kour, Pawanpreet; Kour, Simran; Deeksha; Sharma, A.L.; Yadav, Kamlesh
The synergistic effect of transition metal doping and composite formation can be imperative to improve the limited conductivity and inferior cyclic stability of MoS2 for supercapacitors. In this work, firstly, the impact of Cr-doping on the electrochemical activity of MoS2 has been discussed. Afterwards, the optimized Cr-doped MoS2 (CrMS-5) sample has been combined with CuCo2S4 (CCS) to further enhance its charge storage ability and cyclic stability. The CrMS-5/CCS composite delivers tremendous electrochemical activity as an electrode with a specific capacity of approximately 1324.08 C g?1 at 4 A g?1. The outstanding performance of the doped binary composite is on account of the synergism between doping and composite formation that results in increased conductivity and numerous redox active sites for charge storage. Furthermore, a symmetric supercapacitor device (SSC) has been fabricated using a CrMS-5/CCS electrode. It attains a high energy density of 46.63 Wh kg?1 corresponding to 1 kW kg?1 of power and exhibits remarkable cyclic stability of 81% for up to 5,000 cycles. The device illuminates a star-shaped LED panel of 12 red LEDs for 30 min. Thus, the above outcomes demonstrate the superiority of the doped MoS2-based composites for high-energy symmetric supercapacitors. � 2023 Elsevier Ltd
Anisotropic short-range attractions precisely model branched erythrocyte aggregates
(Royal Society of Chemistry, 2023-10-17T00:00:00) Yadav, Megha; Vanshika, None; Singh, Chamkor
Homogeneous suspensions of red blood cells (RBCs or erythrocytes) in blood plasma are unstable in the absence of driving forces and form elongated stacks, called rouleaux. These erythrocyte aggregates are often branched porous networks - a feature that existing red blood cell aggregation models and simulations fail to predict exactly. Here we establish that alignment-dependent attractive forces in a system of dimers can precisely generate branched structures similar to RBC aggregates observed under a microscope. Our simulations consistently predict that the growth rate of typical mean rouleau size remains sub-linear - a hallmark from past studies - which we also confirm by deriving a reaction kernel taking into account appropriate collision cross-section, approach velocities, and an area-dependent sticking probability. The system exhibits unique features such as the existence of percolated and/or single giant cluster states, multiple coexisting mass-size scalings, and transition to a branched phase upon fine-tuning of model parameters. Upon decreasing the depletion thickness we find that the percolation threshold increases but the morphology of the structures opens up towards an increased degree of branching. Remarkably the system self-organizes to produce a universal power-law size distribution scaling irrespective of the model parameters. � 2023 The Royal Society of Chemistry.
Effects of Dy3+-doping on the band-gap widening and formation of mixed cubic and monoclinic phases of Sm2O3 nanoparticles
(Springer Science and Business Media Deutschland GmbH, 2023-10-30T00:00:00) Sain, Rachana; Roy, Ayan; Kumar, Ajay; Anu; Deeksha; Kour, Pawanpreet; Singh, Ravi Pratap; Yadav, Kamlesh
We synthesized Sm2?xDyxO3 (where X = 0.00, 0.03, 0.06, 0.09, and 0.12) nanoparticles using a co-precipitation method and investigated their structural and optical properties. X-ray diffraction (XRD) results reveal that Dy3+-doping in Sm2O3 nanoparticles leads to the formation of a monoclinic polymorphic phase along with the cubic phase of Sm2O3 and its fraction increases with increasing Dy3+-doping concentration. The substitution of Dy3+ at the Sm3+ site converts the cubic Sm2O3 unit cells into distorted monoclinic Sm2?XDyXO3 unit cells. The average crystallite and nanoparticle sizes decrease with increasing Dy3+-doping concentration. Dy3+-ions act as particle size inhibitors, which is attributed to an increase in the segregation of Dy3+-dopant ions at the surface of the nanoparticles with increasing Dy3+-doping content. The peak appearing at 851�cm?1 in the Fourier transform infrared spectroscopy (FTIR) spectra confirms the formation of Sm2O3. Widening of the band gap (Eg) above the band gap of pure cubic Sm2O3 with Dy3+-doping concentration has been observed for X > 0.06, which is due to the Moss-Burstein and quantum size effects. � 2023, The Author(s), under exclusive licence to Springer-Verlag GmbH, DE part of Springer Nature.
NiO and magnetic CuFe2O4-based composite electrocatalyst for enhanced oxygen evolution reaction
(Springer Science and Business Media Deutschland GmbH, 2023-09-13T00:00:00) BaQais, Amal; Shariq, Mohammad; Almutib, Eman; Al-Qasmi, Noha; Azooz, R.E.; Ali, Syed Kashif; Hassan, K.F.; Iqbal, Muzahir
The biggest concerns confronting the modern world are the depletion of nonrenewable energy sources and rising global temperatures. The use of O2 as an alternative energy source offers a potential answer to these problems. Low-cost electrocatalysts are growing approach for electrocatalytic water splitting, such as oxygen evolution reaction (OER). Oxygen evolution reactions are tremendously well-catalyzed by inexpensive transition metal oxide-based nanostructures. Here, we present a new composite NiO/CuFe2O4 nanostructure and further investigate its potential for electrocatalytic OER applications. Microscopic and spectroscopic methods such as FE-SEM, XRD, XPS, and FTIR were utilized to explore the morphology and structural characteristics of the electrocatalyst. The composite NiO/CuFe2O4 catalyst demonstrates excellent electrochemical OER accomplishment with the overpotential of 297�mV for an alkaline medium to acquire the current density of 10�mA/cm2 and a low Tafel slope of 63�mV/dec?1 to confirm the faster reaction of the composite catalyst. The synergism between the metal ions Ni, Cu, and Fe makes the composite catalyst more efficient in its catalytic activity so; the as-prepared structure demonstrates higher electrocatalytic OER execution with cyclic stability and durability than its pristine constituents. The results show that the NiO/CuFe2O4 composite has the potential to act as an electrocatalyst for the splitting of water. � 2023, The Author(s), under exclusive licence to Societ� Italiana di Fisica and Springer-Verlag GmbH Germany, part of Springer Nature.
Electrochemical performance investigation of different shaped transition metal diselenide materials based symmetric supercapacitor with theoretical investigation
(Elsevier B.V., 2023-10-11T00:00:00) Tanwar, Shweta; Singh, Nirbhay; Vijayan, Ariya K.; Sharma, A.L.
Transition metal diselenide-based electrodes for hybrid symmetric supercapacitors appear as trending materials. Thereby in this paper, we report the preparation of different-shaped transition metal diselenides using a single-step hydrothermal route. The impact of the different morphology of the prepared transition metal diselenide material has been studied on their electrochemical performance. The nanoflower-shaped MoSe2 material was observed to deliver the highest electrochemical result than nanoneedles and nanospheres shape of CoSe2 and NiSe2 material respectively. The highest specific capacitance delivered by the MoSe2 material-based symmetric supercapacitor was 154 F g?1 at 10 mV s?1. It also exhibits a maximum energy density of 17 Wh kg?1 with 1267 W kg?1 power density. Further, the MoSe2-based symmetric supercapacitor has been utilized to burn different colors of light-emitting diodes along with a panel of 26 LEDs of red color. To make the working of the symmetric supercapacitor (MoSe2-based) easier to understand for the readers we have proposed a mechanism of charge storage associated with it. Additionally, the experimental finding has been supported by investigating the structural and electronic properties of MoSe2, CoSe2, and NiSe2 via density functional theory calculation. � 2023
Preparation and Energy Storage Assessment of Ti3C2 2d MXene and Its Possible Thinning Mechanism
(Springer Nature, 2023-09-07T00:00:00) Singh, Diya; Rani, Pinki; Biswas, Sayani; Alegaonkar, Prashant S.
Since after its discovery, MXene has captivated the focus of many researchers. In this work, we report on the low-temperature synthesis of Ti3AlC2 MAX phase at 800�? and its further etching to obtain Ti3C2 MXene. Initially, titanium (Ti), aluminium (Al), and graphite (C) precursors were taken in an appropriate volume proportion and add-mixed and grounded well via molten salt technique (Galvin et al. in J Eur Ceram Soc 38, 2018 [1]). The characterizations performed on powder such as FTIR, XRD, UV�Visible, SEM, and EDS confirmed Ti3AlC2 MAX phase. The MAX phase was subjected to the acid treatment (HF, concentration 40%) for ~ 80�h. The synthesized MXene was separated and investigated using FTIR, XRD, UV�Visible, SEM, and EDS techniques. The MXene was further employed to microwave treatment over the temperature 300�420�K at a discharge of power 120 W for 1�h. Analysis revealed that thickness of Ti3C2 layers is observed to be decreased with microwave treatment which can be a possible mechanism to obtain MXene quantum dots. In electrochemical analysis, specific capacitance for two electrode MXene@300�K and @400�K is reported to be 15 and 10�F/g, respectively, showing resistive nature of capacitance coupling for MXene. Analysis of electrochemical impedance spectroscopy together with bode showed the surface passivation effect of MXene layers to achieve different charge dynamics in both the systems. � 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.
Thermophysical Assessments on Self-Assembled Tellurium Nanostructures
(American Chemical Society, 2023-09-01T00:00:00) Sudheer, Manjima; Rani, Pinki; Patole, Shashikant P.; Alegaonkar, Prashant S.
Thermal properties of self-assembled nanostructures are of great importance to explain the structural phase transformation phenomenon. We report on the thermophysical assessments on tellurium nanostructures (TeN) that have been prepared using a facile wet-chemical technique by admixing precursor sodium telluride (Na2TeO3) and sodium molybdate (Na2MoO4) catalysts in hydrazine hydrate solution and heated at 120 �C, over 5-7 h. The extracted products (interval: 0.5 h) were subjected to a number of spectro-microscopic techniques including thermal measurements. Under identical growth conditions, the morphology of TeN was found to be transformed from Te nanotube (TT) to Te nanoflake (TF) at 6 h. Analysis revealed that Mo participated actively during 6 h of growth time, thereby making bonds with oxygen and the Te host lattice. At the vicinity of the phase transformation, Mo acquired an interstitial position in the hexagonal motif due to enhancement in catalytic efficiency that led to the formation of MoO2- moieties, which transiently reacted with host lattices resulting in surface charging of the tubes. This, in turn, created the coalescing effect with neighboring colloidal tubes through the van der Waals interaction. Thermal properties such as thermal conductivity, effusivity, diffusivity, and specific heat studied for TeN showed prominent surface effects. The increased surface area and enhanced amount of polycrystallinity resulted in unprecedently low thermal properties of TF due to severe phonon confinement. � 2023 American Chemical Society.
All-redox hybrid supercapacitors based on carbon modified stacked zinc cobaltite nanosheets
(Royal Society of Chemistry, 2023-09-12T00:00:00) Kour, Simran; Kour, Pawanpreet; Sharma, A.L.
The role of energy in the present century has increased with the fast advancement of the global economy. In this regard, hybrid supercapacitors (HSCs) as energy storage systems have become an extensive research focus worldwide. This study reports the synthesis of carbon-loaded ZnCo2O4 stacked nanosheets via an in situ hydrothermal process followed by annealing. The electrochemical response was tested in a 2-electrode system. The optimized composite exhibited a capacitance of ?527.6 F g?1 at 5 mV s?1. The symmetric SC (SSC) possessed an energy density (Ed) of ?17.3 W h kg?1 corresponding to a power density (Pd) of 2.25 kW kg?1. Two asymmetric all-redox HSCs have also been fabricated using an optimized composite material as the positive electrode. The previously synthesized MnCo2O4/AC (HSC1) and MnO2/AC (HSC2) were taken as negative electrodes. HSC1 exhibited an Ed of ?24.4 W h kg?1 corresponding to a Pd of ?0.8 kW kg?1. On the other hand, HSC2 exhibited the highest Ed of ?30.8 W h kg?1 at 2.4 kW kg?1. The real-time application of the composite is tested with the fabricated HSCs. HSC1 exhibited a capacitive retention of ?72.2% after 10 000 cycles. On the other hand, HSC2 exhibited a capacitive retention of ?73.4% after 10 000 cycles. The SSC, HSC1, and HSC2 illuminated a 39 red LED panel for ?3 min, 7 min, and 13 min, respectively. The results suggested the promising performance of all-redox HSCs. The overall results present a sustainable approach for creating hierarchical energy materials for the construction of future energy-storage systems. � 2023 The Royal Society of Chemistry.
Theoretical investigation of quantum capacitance of Co-doped ?-MnO2 for supercapacitor applications using density functional theory
(Royal Society of Chemistry, 2023-09-07T00:00:00) Vijayan, Ariya K.; Sreehari, M.S.; Kour, Simran; Dastider, Saptarshi Ghosh; Mondal, Krishnakanta; Sharma, A.L.
The rapid depletion of fossil fuels and ever-growing energy demand have led to a search for renewable clean energy sources. The storage of renewable energy calls for immediate attention to the fabrication of efficient energy storage devices like supercapacitors (SCs). As an electrode material for SCs, MnO2 has gained wide research interest because of its high theoretical capacitance, variable oxidation state, vast abundance, and low cost. However, the low electric conductivity of MnO2 limits its practical application. The conductivity of MnO2 can be enhanced by tuning the electronic states through substitution doping with cobalt. In the present work, first principles analysis based on density functional theory (DFT) has been used to examine the quantum capacitance (CQC) and surface charge (Q) of Co-doped MnO2. Doping enhanced the structural stability, electrical conductivity, potential window, and quantum capacitance of ?-MnO2. The shortened band gap and localized states near the Fermi level improve the CQC of ?-MnO2. For the narrow potential range (?0.4 to 0.4 V), the CQC is observed to increase with doping concentration. The highest CQC value at +0.4 V is observed to be 2412.59 ?F cm?2 for Mn6Co2O16 (25% doping), five times higher than that of pristine MnO2 (471.18 ?F cm?2). Mn6Co2O16 also exhibits better CQC and �Q� at higher positive bias. Hence, it can be used as an anode material for asymmetric supercapacitors. All these results suggest better capacitive performance of Co-doped ?-MnO2 for aqueous SCs and as an anode material for asymmetric supercapacitors. � 2023 The Royal Society of Chemistry.
Observation of magnetic vortex configuration in non-stoichiometric Fe3O4 nanospheres
(Royal Society of Chemistry, 2023-08-31T00:00:00) Niraula, Gopal; Toneto, Denilson; Goya, Gerardo F.; Zoppellaro, Giorgio; Coaquira, Jose A. H.; Muraca, Diego; Denardin, Juliano C.; Almeida, Trevor P.; Knobel, Marcelo; Ayesh, Ahmad I.; Sharma, Surender K.
Theoretical and micromagnetic simulation studies of magnetic nanospheres with vortex configurations suggest that such nanostructured materials have technological advantages over conventional nanosystems for applications based on high-power-rate absorption and subsequent emission. However, full experimental evidence of magnetic vortex configurations in spheres of submicrometer size is still lacking. Here, we report the microwave irradiation fabrication of Fe3O4 nanospheres and establish their magnetic vortex configuration based on experimental results, theoretical analysis, and micromagnetic simulations. Detailed magnetic and electrical measurements, together with M�ssbauer spectroscopy data, provide evidence of a loss of stoichiometry in vortex nanospheres owing to the presence of a surface oxide layer, defects, and a higher concentration of cation vacancies. The results indicate that the magnetic vortex spin configuration can be established in bulk spherical magnetite materials. This study provides crucial information that can aid the synthesis of magnetic nanospheres with magnetically tailored properties; consequently, they may be promising candidates for future technological applications based on three-dimensional magnetic vortex structures. � 2023 RSC.
Investigation of Cr3+ doped Zn-Co nanoferrites as potential candidate for self-regulated magnetic hyperthermia applications
(Institute of Physics, 2023-07-27T00:00:00) Valente-Rodrigues, C.L.; Caraballo-Vivas, Richard J; Santos, Evelyn C S; Sharma, Surender K; Garcia, Fl�vio
Controlling the Curie temperature (TC) in the range from 42 �C-46 �C in magnetic hyperthermia (MH) therapy is an essential research topic because overheating can cause irreversible damage to healthy tissue. When TC is in the above temperature range, the magnetic nanoparticles reach a paramagnetic state, effectively turning off the MH treatment. In this work, we synthesized Zn-Co nanoparticles of representative composition Zn0.54Co0.46CrxFe2-xO4, where the Fe3+ cations are carefully replaced by Cr3+ ions, which allow a precise tuning of TC and hence the self-regulation of MH. The x-ray diffraction analysis of the prepared nanoparticles confirms the formation of a single-phase cubic spinel structure. The average crystallite of the nanoparticles increases with Cr3+ doping, while the Tc and saturation magnetization decrease considerably from 78 �C (x = 0.1) to 27 �C (x = 0.6) and 46.6 emu g?1 (x = 0.1) to 15.3 emu g?1 (x = 0.6), respectively. Besides MH potential of the investigated samples as revealed from specific absorption rate (SAR) assays and the maximum temperature reach (Tmax), vary from 7 W g?1 and 37.3 �C, for x = 0.6, to 38 W g?1 and 62.9 �C, for x = 0.1, we found that the composition Zn0.54Co0.46Cr0.4Fe1.6O4 is more promising with SAR of 22 W g?1 and Tmax = 42.3 �C, which is precisely lies in the safe temperature range to automatically activate the self-regulation during the magnetic hyperthermia treatment. The results reveal an excellent combination between size distribution and Cr3+ content in Zn-Co-based ferrite, which has a great potential for self-regulated magnetic hyperthermia applications. � 2023 IOP Publishing Ltd
Design and Manufacturing of a Hexapattern Frequency Selective Surface Absorber for Aerospace Stealth Application
(American Chemical Society, 2023-07-21T00:00:00) Priyanka, None; Mohanty, Subrat; Alegaonkar, Prashant S.; Baskey, Himangshu B.
Integrated frequency selective surface (IFSS) absorbers with larger bandwidth, effective reflection loss, polarization-insensitive characteristics, angular stability with compact/thin design, and ease of fabrication have captivated significant importance in stealth technology. Herein, we report on an IFSS absorber that has been designed, simulated, and implemented for manufacturing to achieve effective stealth properties. Initially, frequency selective surface (FSS) layers have been designed that comprise a closed centroid honeycomb structure surrounded with four annular hexagonal rings, splitted, alternatively, and enveloped with four L-shaped elements. The simulated pattern has been optimized on glass fabric for reflection loss (RC, dB) at a thickness of ?0.1 mm by choosing sheet resistance of pattern 110 ?/?. A FSS layer combined with interlayer lossy dielectric laminates (1.8 mm) and a carbon-fabric-reinforced-plastic ground has been simulated as an IFSS absorber. The performance of RC, in normal and angular configuration (0-60�), under transvers an electric/magnetic mode of polarization, including analysis of the displacement current, volume power loss distribution, and complex admittance has been carried on IFSS. Subsequently, the proposed absorber has been fabricated using customized carbon-based resistive ink imprinted on glass fabric by mask lithography compounded with laminates (a carbon black powder/epoxy composite) and ground. Their manufacturing details, including free space and anechoic chamber RC measurements, have been presented. The simulated and experimental RC performances of the absorber are found to be in good agreement, possessing minimal 10 dB reflection loss (90% absorption) with a sample thickness of 1.9 mm (0.05?L, where ?L corresponds to a lower operating frequency), covering 76% fractional bandwidth in X and Ku bands. The proposed design architecture of the IFSS is ideally suitable for aerospace stealth platforms. � 2023 American Chemical Society.
Predominated capacitive behavior of Ag-doped magnesium vanadate as a novel electrode material for supercapacitors
(Elsevier Ltd, 2023-06-11T00:00:00) Umair, Muhammad; Shad, Naveed Akhtar; Hussain, S.; Jilani, Asim; Sajid, Muhammad Munir; Arshad, Muhammad Imran; Hasnain Rana, Hafiz Talha; Sharma, Surender Kumar; Mishra, Yogendra Kumar; Javed, Yasir
Transition metal vanadate nanostructures are getting significant importance as an efficient electrode material for modern energy storage applications. In this work, a simple hydrothermal method is employed for the synthesis of magnesium vanadate (MgV2O5) and Ag-doped magnesium vanadate (Ag doped MgV3O8) nanomaterials. The X-ray diffraction (XRD) analysis reveals the formation of an orthorhombic structure for magnesium vanadate, whereas the Ag-doped magnesium vanadate results in a monoclinic structure. Interestingly, the optical bandgap is observed to increase from 2.85 eV to 3.92 eV with the increase in Ag-doping as revealed from Tauc's plot of the UV-visible absorption spectrum. The electrochemical performance of magnesium vanadate electrodes is thoroughly investigated by cyclic voltammetry (CV), Galvanostatic charge-discharge (GCD), and electrochemical impedance spectroscopy. The Ag-doped magnesium vanadate shows higher specific capacitance (Cs = 706 Fg?1) in comparison to undoped (325 Fg?1) at a current density J = 5 Ag?1. The theoretical investigations through Dunn's model demonstrate a major contribution arises from surface-controlled processes, which increase as high as 91% at scan rate of 60 mVsec?1. Our findings indicate that Ag-doping significantly improves the overall electrochemical response of magnesium vanadate as an efficient electrode material for supercapacitor applications. � 2023 Hydrogen Energy Publications LLC
Investigation of dielectric and ferroelectric properties of pvdf/0.5ba (Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 composite
(Apple Academic Press, 2023-06-02T00:00:00) Muduli, Sakti Prasanna; Parida, S.; Rout, S.K.; Mahapatra, S.K.
(1-x)PVDF-(x)[0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3] composite films with x = 0.1, 0.2, 0.3, 0.4, 0.5 were synthesized and the comparative dielectric properties and ferroelectric properties were studied. 0.5Ba(Zr0.2Ti0.8)O3-0.5(Ba0.7Ca0.3)TiO3 (BZT-BCT) ceramic was synthesized by conventional solid-state reaction method. After phase confirmation of calcined powder, it was added to poly(vinylidene fluoride) (PVDF) solution with different weight percentages, and composite films were prepared by solvent casting followed by hot pressing method. � 2023 Apple Academic Press, Inc.
Strain-mediated magnetoelectricity probed by Raman spectroscopy in h-ErMn O3
(American Physical Society, 2023-07-05T00:00:00) Correa, A.; Barbosa, D.A.B.; De Menezes, A.S.; Valente-Rodrigues, C.L.; Sharma, Surender Kumar; Santos, C.C.
We show the role of strain in magnetoelectric effect through coupling between order parameters and their interplay using infrared/Raman-active optical phonons in hexagonal manganite (h-ErMnO3). The magnetoelectric coupling is arbitrated through strain from infrared-active phonons, which by symmetry are also Raman active. The identification of the primitive order parameters by spin-phonon coupling opens a promising avenue to realize the strategy based on coupling of spins, optical phonons, and strain to create magnetoelectrics with strain-mediated interaction through spin-lattice coupling in bulk inducing a ferromagnetic-ferroelectric state in an antiferromagnetic-paraelectric phase. � 2023 American Physical Society.
Impact of Covid-19 outbreak on stress and depression among Indian football players; [Impacto del brote de Covid-19 en el estr�s y la depresi�n de futbolistas indios]
(Universidad de Murcia, 2023-06-13T00:00:00) Cherappurath, Nafih; Ahmed, Md. Dilsad; L�pez S�nchez, Guillermo F.; Begum, Shaheen; Sreelekha, N.; Elayaraja, M.; Rathnayaka, Anoma; Kabeer, Dilshith Azeezul
The Coronavirus-19 (COVID-19) pandemic restricted our normal life activities for the past several months, continuing its impact. Its repercussions led many countries to remain locked down and closed institutions and workplaces. The closure severely impacted the sporting industry and hindered performing its normal activities. Sports and exercise are generally considered the best facilitator for embedding a healthy and active lifestyle and were not adequately advocated during the pandemic. This study aimed to examine the level of stress and depression among football players during the peak time of the Covid-19 outbreak. Furthermore, it measured whether the socio-demographic information, such as gender, region, and level of participation influenced participants' stress and depression during that time. A total of 204 football players recruited from different parts of India participated in this study. Participants� responses to stress and depression were measured through the Perceived Stress Scale (PSS) and the Patient Health Questionnaire (PHQ-9). Stress and depression showed a significant correlation among the footballers. Socio-demographic variables (except region, level of participation, and age), did not present any significant relationship. Footballers who experienced stress and depression during the Covid-19 pandemic showed positive correlations between the two constructs. Athletes from India's Southern region perceived higher stress levels than those from the Western part of India. The level of participation and age had no significant effect on the participants' perceived stress and depression. � Copyright 2023: Publication Service of the University of Murcia, Murcia, Spain.
Insight into use of biopolymer in hybrid electrode materials for supercapacitor applications�A critical review
(American Institute of Physics Inc., 2023-05-12T00:00:00) Tanwar, Shweta; Sharma, A.L.
The shortage of natural resources due to the progression of the human population and environmental pollution has become crucial concern topics to resolve. One of the best ways to resolve this is to develop renewable energy-based storage systems. Supercapacitors are emerging as promising storage systems via providing rapid charging/discharging and high power delivery, but there is a need to explore low-cost, environment-friendly, non-toxic, abundant, and biodegradable electrode materials for supercapacitors. In this regard, biopolymers are observed to be popular for storage applications as they are of high porosity, cost-effective, easily available, low-weight, and environment friendly and have biodegradability properties. The biopolymer-based electrode has a desirable morphology and high surface area and exhibits admirable electrochemical properties. The focus of this report is to highlight (i) the inclusive details of supercapacitors and their types along with strategies to improve their electrochemical performance, (ii) biopolymers and their types used for supercapacitor applications, (iii) various synthesis routes that could be adopted for designing electrode materials based on biopolymers for supercapacitors, and (iv) challenges and future scope of biopolymers as the electrode material in supercapacitor applications. The detailed study here in this report is found to be a topic of interest for the scientific community to fabricate and prepare low-cost, eco-friendly, high electrochemical performance exhibiting electrode materials for supercapacitor applications. � 2023 Author(s).
Investigation of Structural and Electrochemical Properties for Orange Peel Derived Carbon
(Springer Science and Business Media Deutschland GmbH, 2023-05-21T00:00:00) Simple; Kushwaha, K.K.; Tanwar, Shweta; Sharma, A.L.
From this study, we get to know about the concentration effect of activating agent which is phosphoric acid (H3PO4) on the structural, and electrochemical behaviour of carbon produced from orange peel. We have taken various concentrations of H3PO4 (0.5�M, 1�M, 1.5�M) and activated the orange peel-derived carbon (OPC) followed by sintering in the furnace. The structural and chemical nature is analyzed by performing powder x-ray diffraction (XRD) and Fourier-transform infrared (FTIR) tools. The electrochemical measurements are also done via cyclic voltammetry (CV), galvanostatic charge�discharge (GCD), and electrochemical impedance spectroscopy (EIS) techniques. At scan rate of 20�mV�s?1we discovered that sample named 1�M possess the greatest specific capacitance value of 5.55 F g?1. At the current density of 1 A g?1 specific energy is 0.189 Wh Kg?1 and specific power is 486.8 W Kg?1. As a result, raising the concentration of the solution from 0.5 to 1�M, there is a rise in electrochemical behavior but as we go from 1 to 1.5�M fall in the behavior is seen. The reason behind this is that in higher concentrations the specific area of the electrode for the ions to get accommodated decreases due to an increase in micropores. So, 1�M of 85% (w/v) H3PO4 will be a promising candidate for activating the orange peel-derived carbon (OPC) to obtain enhanced electrochemical performance for energy storage applications. � 2023, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

Browse

Recent Submissions