V2O5 encapsulated MWCNTs in 2D surface architecture : complete solid-state bendable highly stabilized energy efficient supercapacitor device

A simple and scalable approach has been reported for O encapsulation over interconnected multi-walled carbon nanotubes (MWCNTs) network using chemical bath deposition method. Chemically synthesized O/MWCNTs electrode exhibited excellent charge-discharge capability with extraordinary cycling retention of 93% over 4000 cycles in liquid-electrolyte. Electrochemical investigations have been performed to evaluate the origin of capacitive behavior from dual contribution of surface-controlled and diffusion-controlled charge components. Furthermore, a complete flexible solid-state, flexible symmetric supercapacitor (FSS-SSC) device was assembled with O/MWCNTs electrodes which yield remarkable values of specific power and energy densities along with enhanced cyclic stability over liquid configuration. As a practical demonstration, the constructed device was used to lit the 'VNIT' acronym assembled using 21 LED's

Cohort Profile: Burden of Obstructive Lung Disease (BOLD) study

The Burden of Obstructive Lung Disease (BOLD) study was established to assess the prevalence of chronic airflow obstruction, a key characteristic of chronic obstructive pulmonary disease, and its risk factors in adults (≥40 years) from general populations across the world. The baseline study was conducted between 2003 and 2016, in 41 sites across Africa, Asia, Europe, North America, the Caribbean and Oceania, and collected high-quality pre- and post-bronchodilator spirometry from 28 828 participants. The follow-up study was conducted between 2019 and 2021, in 18 sites across Africa, Asia, Europe and the Caribbean. At baseline, there were in these sites 12 502 participants with high-quality spirometry. A total of 6452 were followed up, with 5936 completing the study core questionnaire. Of these, 4044 also provided high-quality pre- and post-bronchodilator spirometry. On both occasions, the core questionnaire covered information on respiratory symptoms, doctor diagnoses, health care use, medication use and ealth status, as well as potential risk factors. Information on occupation, environmental exposures and diet was also collected

Exploring the impact of sintering additives on the densification and conductivity of BaCe0.3Zr0.55Y0.15O3-δ electrolyte for protonic ceramic fuel cells

Ceramic proton conducting BaCeO3-BaZrO3 materials have received great interest as potential electrolyte candidates for intermediate temperature protonic ceramic fuel cells. In the current work, the impact of sintering additives ZnO, NiO and CuO on densification, microstructure and electrochemical properties of the state-of-the-art electrolyte composition BaCe0.3Zr0.55Y0.15O3-δ (BCZY35) is appraised. Highly dense (> 95%) BCZY35 electrolyte pellets are obtained at the temperature of 1400 °C by use of the sintering additives, whereas only ~86% relative density is achieved for the pristine material at this temperature. The BCZY35 composition is shown to offer high chemical stability against a pure CO2 environment, as confirmed by thermogravimetric analysis. The electrical conductivity of BCZY35 with and without sintering additives is studied as a function of temperature in humid N2, O2 and H2 by A.C. impedance spectroscopy. In general, slightly lowered total conductivities are observed for all sintering additive specimens than the pristine BCZY35 material. The bulk conductivity is shown to be significantly impaired by the addition of sintering additives, in all cases, while specific grain boundary conductivity is either relatively unaffected, NiO, CuO, or improved, ZnO. This interesting feature is analysed further by application of a space-charge model, highlighting the additive containing compositions to offer lower Schottky barrier heights than the base BCZY35 phase and with this factor being most significant for the ZnO-additive. The activation energy for total and bulk conductivities is found to be in the range of 0.4–0.6 eV under humid conditions in the temperature range 400–600 °C, while slightly higher Ea values ~0.72–0.77 eV are observed for the grain boundary conductivity. The total conductivity of BCZY35 reaches the value of ~3.69 × 10-3 S cm−1 at 500 °C in humid nitrogen and hydrogen, where protons are expected to be the majority charge carriers. The results show the BCZY35 electrolyte composition to be promising to use in intermediate temperature protonic ceramic electrochemical cell applications, with the peak sintering additive being that of ZnO

Quantum confinement of Bi2S3 in glass with magnetic behavior

The novel Bi2S3 quantum dots (QDs) glass nanosystems with unique magnetic properties have been investigated. The monodispersed QDs of size in the range of 3 to 15 nm were grown in the glass matrix. The optical study of these nanosystems clearly demonstrated the size quantization effect resulting in a pronounced band gap variation with QD size. The magnetic properties of the pristine glass and the Bi2S3 QD glass nanosystems were investigated by VSM and SQUID magnetometer. The pristine glass did not show any ferromagnetism while the Bi2S3 glass nanosystems showed significant and reproducible ferromagnetism. We also investigated the effect of the size of Bi2S3 QDs on the magnetic properties. The saturation magnetization for the 15 nm QD glass-nanosystem (124 memu/g) was observed to be higher as compared to the 3nm QD glass nanosystem (58.2 memu/g). The SQUID measurement gave the excellent hysteresis up to 300K. Surprisingly, the bulk Bi2S3 powder is diamagnetic in nature but Bi2S3 quantum dots glass nanosystem showed the ferromagnetic behavior for the first time. The investigated novel QD glass-nanosystem may have a potential application in spintronic devices and most importantly, this nanosystem can be fabricated in any usable shape as per the device requirement

V2O5 encapsulated MWCNTs in 2D surface architecture : complete solid-state bendable highly stabilized energy efficient supercapacitor device

A simple and scalable approach has been reported for O encapsulation over interconnected multi-walled carbon nanotubes (MWCNTs) network using chemical bath deposition method. Chemically synthesized O/MWCNTs electrode exhibited excellent charge-discharge capability with extraordinary cycling retention of 93% over 4000 cycles in liquid-electrolyte. Electrochemical investigations have been performed to evaluate the origin of capacitive behavior from dual contribution of surface-controlled and diffusion-controlled charge components. Furthermore, a complete flexible solid-state, flexible symmetric supercapacitor (FSS-SSC) device was assembled with O/MWCNTs electrodes which yield remarkable values of specific power and energy densities along with enhanced cyclic stability over liquid configuration. As a practical demonstration, the constructed device was used to lit the 'VNIT' acronym assembled using 21 LED's

V2O5 encapsulated MWCNTs in 2D surface architecture: Complete solid-state bendable highly stabilized energy efficient supercapacitor device

A simple and scalable approach has been reported for V2O5 encapsulation over interconnected multi-walled carbon nanotubes (MWCNTs) network using chemical bath deposition method. Chemically synthesized V2O5/MWCNTs electrode exhibited excellent charge-discharge capability with extraordinary cycling retention of 93% over 4000 cycles in liquid-electrolyte. Electrochemical investigations have been performed to evaluate the origin of capacitive behavior from dual contribution of surface-controlled and diffusion-controlled charge components. Furthermore, a complete flexible solid-state, flexible symmetric supercapacitor (FSS-SSC) device was assembled with V2O5/MWCNTs electrodes which yield remarkable values of specific power and energy densities along with enhanced cyclic stability over liquid configuration. As a practical demonstration, the constructed device was used to lit the VNIT acronym assembled using 21 LEDs.BP gratefully acknowledges to VNIT for providing institute fellowship. BRS acknowledges to the DST/TMD/MES/2k16/09 project, Govt. of India. DPD and PGR acknowledge AGAUR (Gen Cat) (for Project NESTOR 2014_SGR_1505) and MINECO (for Grant MAT2015-68394-R, MINECO/FEDER). ICN2 acknowledges support of the Spanish MINECO through the Severo Ochoa Centers of Excellence Program under Grant SEV-2013-0295

The effect of nickel doping on the microstructure and conductivity of Ca(Ti,Al)O3-delta for solid oxide fuel cells

The ABO(3) type perovskite oxide-based ceramic membranes are one of the most important classes of materials for high-temperature solid oxide fuel cell applications. The acceptor-doped calcium titanate (CaTiO3) perovskite has attracted considerable attention as an oxide ion-conducting membrane due to its potentially high ionic conductivity and excellent stability. Nonetheless, the ionic conductivity of the material must still be improved. Following the strategy of the substitution of dopants on the B-site, the current work is focused on exploring the effect of Al and Ni additions on electrical properties, by studying the nominal compositions CaTi0.7Al0.3-xNixO3-delta (x = 0, 0.1, 0.2 and 0.3). The materials were synthesized by the sol-gel method and studied as a function of phase composition, microstructure, and electrical properties. The results demonstrate an increase of both total and specific grain boundary conductivity with increasing Ni content, while predominant p-type behavior is shown under oxygen-rich atmosphere