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Co-exfoliated GNP/MoS2 was synthesized in one step and used for supercapacitor study.

Being cognizant of modern electronic devices, the scientists are continuing to investigate renewable green-energy resources for a decade. Amid different energy harvesting systems, the triboelectric nanogenerators (TENGs) have been found to be the most promising mechanical harvesting technology and have drawn attention to generate electrical energy. Thanks to its instant output power, choice to opt for wide-ranging materials, low maintenance cost, easy fabrication process and environmentally friendly nature. Due to numerous working modes of TENGs, it is dedicated to desired application at ambient conditions. In this review, an advance correlation of TENGs have been explained based on the variety of nanostructures, including 0D, 1D, 2D, 3D, metal organic frameworks (MOFs), coordination polymers (CPs), covalent organic frameworks (COFs), and perovskite materials. Moreover, an overview of previous and current perspectives of various nanomaterials, synthesis, fabrication and their applications in potential fields have been discussed in detail.

Bimodal NiCo2O4·MnO2 (NCM) nanorods were grown on carbon fiber paper (CFP) using a hydrothermal process. The structural and morphological studies were performed via powder X-ray diffraction and field-emission scanning electron microscopy, respectively. The aspect ratio of the developed electrode significantly improved up to a threshold concentration of manganese in the Ni/Co binary oxide, and thereafter decreased. The capacitive performance and electrochemical parameters of the developed NCM nanorods were analyzed using cyclic voltammetry, galvanostatic charge–discharge, and impedance spectroscopy. The maximum specific capacitance of the developed NCM nanorods was found to be 2575 F g−1 (305 mA h g−1) at a current density of 5 A g−1. Additionally, the excellent cyclic retention of nearly 92.5% was achieved for the NCM nanocomposite even after 5000 cycles. Also, the response time (τo) calculated from the Bode plot was found to be ∼22 s, which validated the fast charging of the developed electrode material. Furthermore, an asymmetric solid-state supercapacitor (ASC) device was successfully assembled utilizing NCM (1 : 2 : 2) nanorods and activated carbon as positive and negative electrodes, respectively. The developed device achieved a capacitance of 130 F g−1 (176.1 mA h g−1) with an energy density and power density of 138 W h kg−1 and 722 W kg−1, respectively, which could illuminate an LED bulb (1.8 V) for 50 min.

Due to environmental crisis and developed numerous portable electronic device and electric vehicles, it is necessary to find commercial alternative energy source to fulfil the future charge storage demand. In the present work, we have addressed the facile sol–gel root for the synthesis of Bismuth ferrite (BFO) along with modified carbon solution. The effect of carbon on structure, morphology and electrical properties on the BFO ceramic were investigated. XRD study reveals the prepared samples were found to be highly amorphous and rhombohedral structure. The morphology analysis demonstrates that the modified BFO nanoparticles size (∼20 nm) is smaller than pure BFO of size (∼30 nm) which helps to reduces the leakage current and improved electrical properties. Influence of carbon solutions on the BFO have been investigated for supercapacitor application. The modified BFO exhibited good electrochemical energy storage performance with a specific capacity of 678 Fg−1 at a scan rate of 5 mVsec−1 and excellent cyclic retention ∼90.5% even after 3000 cycles. In addition, the developed electrode materials are used to fabricate an asymmetric solid-state supercapacitor (ASC) device for demonstrating the practical applicability.

Understanding the concept of light–matter interaction in organic–inorganic nanostructures such as graphene and metal-halide perovskites has been explored to realize photonic and optoelectronic devi...

Lead-free Ba0.85Ca0.15Zr0.1Ti0.9O3 piezoelectric nanofiber was synthesized using the electrospinning technique. The surface of sintered BCZT nanofibers was modified by dopamine via the chemical coating method. Dopamine-modified BCZT nanofibers were used as fillers in polyvinylidenefluoride–hexafluoropropylene (PVDF-HFP) polymer matrix to cast flexible composite films by solution casting method. Nanofibers and composite films were analyzed by XRD and FE-SEM to investigate crystal structure and morphology, respectively. The broadband dielectric spectroscopy was carried out in composite films having 3.4–24.1 vol% BCZT nanofibers. The composite film having 24.1 vol% nanofibers showed a maximum dielectric constant (61 at 1 kHz) compared with other films. A flexible nanogenerator (NG) was fabricated using epoxy as a packing material. The developed NG tested in different tapping modes and exhibited maximum output voltage and power density around 10 V and 2.9 μW/cm3, respectively.

Spherical-shaped multiferroic BiFeO 3 were synthesized successfully by hydrothermal method having diameter of tens of nanometre with good crystallinity. The structural and micro-structural studies were done by X-Ray diffraction, Raman analysis and high-resolution transmission electron microscope. Frequency dependent dielectric measurements were done to study the change in dielectric permittivity of different samples of BFO. It was found out that the value of dielectric permittivity nearly doubles for the poled and the calcined samples as compared to the unpoled and the as-synthesized samples, respectively. Magnetic characterisation showed the temperature dependence & particle size dependence of coercivity. It also revealed the anti-ferromagnetic nature at room temperature and weak ferromagnetic nature at 10 K. The results showed that the poled nanoparticles might be useful in designing the energy storage devices coupled with magnetic functionalities like microcapacitors.

Nonwoven fabric composite formulating polycarbonate (PC) and CuPc was fabricated using electrospun (CuPc: 0 to 10 wt%). Spatial presence of CuPc in composites was ascertained by virtue of F...

Phase pure BiFeO3 (BFO) and Bi0.98Ba0.02Fe1-xCrxO3 (x = 0.01, 0.02, 0.03, 0.04) nanoparticles were synthesized by a facile sol-gel route. X-ray diffraction data confirms rhombohedral R3c phase of BFO and Ba, Cr co-doped BFO nanoparticles with a slight distortion at higher dopant concentration. TEM images verified the higher crystallinity of the samples with a significant reduction in particle size (∼40 nm) with increasing Cr concentration. The band gap of pristine BFO nanoparticles was found to be 1.8 eV which increases remarkably to a maximum of 2.32 eV for Ba, Cr co-doped BFO nanoparticles. 57Fe Mossbauer spectroscopy confirmed that no mixed valance state of Fe was present in the Ba, Cr co-doped BFO nanoparticles. Hysteresis loops of all the samples revealed the weak ferromagnetic nature of the co-doped BFO nanoparticles. It was observed that the saturation magnetization increased by more than 3 times when Cr content was increased from 1% to 4%.

In present study, we have synthesized intrinsically conductive poly(1,6-heptadiynes) via cyclopolymerization technique, and further it is composited with the NiFe2O4 to fabricate pellet for electrical and electronic applications. The synthesized polymer I–V characteristics were obtained by two-probe measurement technique. The results suggest that the high current density of the synthesized polymer was in the range of 1.2 × 10–5–3.1 × 10–5 S/cm, which attributes to the potentially induced hoping charge-carrier mechanism within the conjugated poly(1,6-heptadiynes). NiFe2O4 and NiFe2O4/poly(1,6-heptadiynes) composite pellets were fabricated by utilizing hydraulic pelletizer. The sample’s electrical measurements were performed via broad-band dielectric impedance spectroscopy, wherein the composite permittivity was about ε = 45 (100 Hz to 10 kHz), which attributes to the NiFe2O4 and poly(1,6-heptadiynes) phases; further, this describes the capacitance, which improved from 0.3 to 0.1 pf at 1 kHz. Also, these results suggest the reduced equivalent series resistance (72.1–1 MHz), which attributes to the incorporated intrinsically conducting poly(1,6-heptadiynes). Thus, the reduced dissipation factor (DF = 0.0032) was observed from impedance characteristics of a nanocomposite. Moreover, the improved Q-factor was observed, which was about 8.1–310 at 1 kHz. The resistance and capacitance time constant was also computed to be about 0.29 μs at 1 kHz for NiFe2O4/poly(1,6-heptadiynes) nanocomposite. Furthermore, the nanocomposite-enabled capacitor gravimetric energy density and power densities were calculated to be about 0.00575 mJ/g and 9.91 W/g, respectively. Additionally, thermal threatening, that is, heat generated within the capacitor, Ploss is also estimated for the nanocomposite capacitor, which improved from 0.0006 to 8.9 × 10–6, and these results suggest improved nanocomposite thermal stability. Further, the delineated quantities were compared to the commercially available configurations of tantalum hybrid capacitors and Al and Ta electrolytic capacitors, including carbon electrochemical capacitors, which suggest that the reported nanocomposites could be a suitable candidate for electrical and electronic applications.

The successive ionic layer adsorption and reaction (SILAR) experimental process has been used to develop a high-efficiency electrode of MFe

Binary metal sulfides have synthesized at ambient temperature as a positive electrode using ethanol-water as a solvent in the co-precipitation process. The incorporation of sulfur (S) into transition metals could have controlled by changing the solvents, including ethanol and water. The average particle size was measured around 15 nm using electron microscope. The specific surface area calculated around 145 m2 g-1 through NMR based relaxation method. Moreover, it has been found that the particular composition of CNS 1:1:0.15 has drawn immense electrochemical properties based on their discrete morphology. The binary sulfide electrode exhibits excellent pseudocapacitance performance, and delivered specific capacitance (SC) of 2910 F g-1 at 1 A g-1, and simultaneously depicted adequate cyclic retention ~91.5 % up to 10,000 cycles. The energy density (ED), and power density (PD) were evaluated for active electrode about ~123 Whkg−1 and ~285 W kg-1 respectively. Meanwhile, the influence of cation species (Na+, K+& Li+) in electrolyte concentrations illustrates the outstanding supercapacitive performance by decreasing internal resistance. An asymmetric solid-state (ASC) supercapacitor device was assembled which brighten the ~1.8 V of commercial LED for the validation of electrode.

The successive ionic layer adsorption and reaction (SILAR) experimental process has been used to develop a high-efficiency electrode of MFe2O4 (M = Ni, Co and Mn) on substrates at ambient temperature. Structural, morphological and electrochemical properties have been investigated using x-ray diffraction (XRD), a scanning electron microscope (SEM) and an electrochemical test station, respectively. A morphology resembling the Hydrangea macrophylla flower has been observed and tuned with varying Fe concentration. The formation of MFe2O4 demonstrates the efficient electrochemical behavior and the specific capacitance has been evaluated as ∼1380, ∼972 and ∼815 Fg-1 for CoFe2O4 (CF), NiFe2O4 (NF) and MnFe2O4 (MF), respectively, at a current density of 1 Ag-1. Also, the developed electrodes maintain excellent cyclic retention of ∼92%, ∼89% and ∼86% for CF, NF, and MF, respectively, up to 5000 cycles. Further, asymmetric solid-state supercapacitor (ASC) devices have been fabricated using the best compositions of MFe2O4 as a positive electrode and carbon black (CB) as a negative electrode, and successfully illuminate a 1.8 V commercial LED.

Liver is the most common organ involved in echinococcosis. Organs affected by E granulosus are the liver (63%), lungs (25%) and muscles (5%). Rest of the organs are rarely affected. Adrenal cysts are uncommon. Their size may range widely and the origin of large adrenal cysts is often difficult to distinguish from other organs, including the kidney, pancreas, spleen, and liver. A large right-sided adrenal cystic mass can rarely be mistaken for a hepatic cyst by imaging. In this report, authors have described an adrenal cyst in a 28 year old lady, who was diagnosed preoperatively to have a hepatic hydatid cyst but intraoperatively it was found to be of adrenal origin. The size of the adrenal cyst can vary from a few millimetres up to 50 cm in diameter. Majority of the adrenal cysts are unilateral, while 8-10% of those cysts have been noted to be present bilaterally. The majority of cases are diagnosed between the 3rd and 6th decades. Although uncommon, Adrenal cyst should be considered as one of the differential diagnosis of upper abdominal cysts. Surgical excision is advisable when the cysts are symptomatic, greater than 5 cm in diameter and in the case of suspecting malignancy.

BiFeO3 (BFO), 1% and 3% Cr doped Bi0.98Ba0.02FeO3 (BBFCO1 and BBFCO3) nanoparticles were synthesized by facile sol-gel route. All the samples were characterized using XRD, FESEM and Impedance Analyzer. XRD revealed the phase pure formation of samples and the crystallite sizes were well below the periodic order of spiral spin structure of BFO. The particle size decreased with increase in doping concentration of Cr. It was also observed that the permittivity of BBFCO1 and BBFCO3 increased compared to pure BFO at room temperature and dielectric loss decreased for 1% Cr doped and again increased for 3% Cr doped BiFeO3.

We demonstrate a green, facile and rapid microwave-mediated process for fabricating carbon black (CB) incorporated Ni/Co hydroxide porous nanocomposites and study the effect of various mass loading of CB on supercapacitor performance. The structure and interactions between CB and Ni/Co hydroxide are characterized by using x-ray diffraction, Fourier-transform infrared spectroscopy and x-ray photoelectron spectroscopy, which suggest the miniaturization of the single-phase Ni/Co hydroxide formation time. A morphology study reveals that the addition of CB into Ni/Co hydroxide develops a loose network structure with well-defined architectural pores. In addition, the nanocomposites demonstrate noticeable improvements in porosity and atomic ratio of Ni/Co with an increasing percentage of carbon, which results in a higher diffusion of electrolytes, and hence electrical conduction. The developed electrode materials exhibit a maximum specific capacitance value of 1526 Fg-1 at current density 1 Ag-1 with excellent cyclic stability (92% retention at 5000 cycles), energy density (76 Wh Kg-1), power density (250 W Kg-1) and rate capability. A solid state asymmetric supercapacitor device is fabricated and utilized to brighten a commercial LED effectively for validating real usage.

Conventional building materials and by-products from coal power plants which are being used or have the potential for use in buildings in India were analysed for natural radioactivity due to the presence of 226Ra, 232Th and 40K using gamma-ray spectroscopy. The materials examined in this work showed the radioactivity levels below the limit estimated from radium equivalent activity the criterion formula for gamma-activity suggested for acceptable radiation doses attributable to building materials in OECD countries.

CARIM-India: Developing a knowledge base for policymaking on India-EU migration The present paper titled “Irregular Migration from India to EU: Evidence from Punjab” is a part of India-EU project “Developing Knowledge Base for Policymaking on India- EU Migration”. Author of the paper is serving as an Indian Police Service officer in the State of unjab, India and has utilised his first-hand experience of dealing with the problem as Nodal Officer of the State Government to analyse the perspective of law enforcement agency in a source country. CARIM-India is co-financed by the European University Institute and the European Union