Role of Mn impurity in the deterioration of ZnS:Cu,Br electroluminescent phosphors

ZnS:Cu, Br powder EL phosphors showed 6-line EPR signal at 25°C whose intensity increases with Cu content and on annealing in Zn-vapour. The signal arises from native Mn impurity. The starting material does not show any EPR signal since Mn²⁺ acts as an affinity potential well for a hole in ZnS, forming Mn³⁺ - a chemically uncommon situation in sulfides. In doped ZnS, holes are trapped at Cu such that Mn²⁺ persists. Deterioration of EL brightness is accompanied by the decrease in EPR signal intensity due to field assisted hole transference to Mn²⁺. Intentional addition of Mn in ZnS:Cu, Br decreases the brightness and shortens life time. Stable phosphors require ZnS with Mn content less than 10¹⁴ cm^?3.     

Improved performance on seizure detection in an automated electroencephalogram signal under evolution by extracting entropy feature

Multimedia Tools and Applications - In recent years, enormous people in all age category were affected with epilepsy throughout the world. To detect and evaluate the epilepsy seizure, the...     

Robust HI and dysarthric speaker recognition – perceptual features and models

Multimedia Tools and Applications - This paper explores the necessity of having hearing impaired (HI) and dysarthric speakers be part of the person authentication system and it is considered to be...     

Structural,Dielectric,and Magnetic Studies on Electrospun Magnesium Ferrite-Polyvinylidene Fluoride Core–Shell Composite Fibers

The sub-micron(of the order of 150 nm) thick core–shell composite fibers of magnesium ferrite-polyvinylidene fluoride are prepared by electrospinning.The loading of magnesium ferrite is varied from 1 to 10 wt%.The study results by X-ray diffraction,scanning electron microscope,and infra-red spectroscopy indicate the formation of core–shell structure and an enhancement in the amount of b-phase compared to a-phase in the polyvinylidene fluoride.The particle size of the magnesium ferrite in the fiber is evaluated to be 30 nm.The low frequency dielectric studies indicate that the addition of the magnesium ferrite increases the polarization resulting in the increase in the dielectric constant but decreases the dielectric loss.The magnetization measurements indicate an increased value of coercivity compared to bulk due to the nano-size of the magnesium ferrite.The microwave absorption at the ferromagnetic resonance increases with the increase in the concentration of magnesium ferrite.The resonance field is found to vary with the loading of MFO.     

Application of Solid Me3SiZnI for the Synthesis of Aryl and Alkyl Trimethylsilanes

Silylzinc reagents are desirable for the synthesis of organosilanes due to their compatibility with functional groups; however, the use of pyrophoric silyllithium and dissolved lithium salts in their production hinders their development. Our solid Me₃SiZnI circumvents these limitations, and herein, we demonstrate its significance in the synthesis of aryl and alkyl trimethylsilanes via cross-coupling of aryl and alkyl bromides. The milder reaction condition tolerates functional groups such as MOM, Boc, Bpin, and aldehydes.     

Evaluation of structural,optical properties and photocatalytic activity of Ag2O coated ZnO nanoparticles

Journal of Materials Science: Materials in Electronics - The presence of composite in the nanofluid resultant is essential to provide a significant methylene blue (MB) removal property in...     

Synthesis of alkali and acid-mediated rGO–metakaolin nano composites for supercapacitor application

Journal of Materials Science: Materials in Electronics - Two different samples of metakaolin one hardened by acid (10 M phosphoric acid) (MP) and another by alkali (Na2SiO3 of silica...     

Neural Tissue Degeneration in Rosenthal’s Canal and Its Impact on Electrical Stimulation of the Auditory Nerve by Cochlear Implants: An Image-Based Modeling Study

Sensorineural deafness is caused by the loss of peripheral neural input to the auditory nerve, which may result from peripheral neural degeneration and/or a loss of inner hair cells. Provided spiral ganglion cells and their central processes are patent, cochlear implants can be used to electrically stimulate the auditory nerve to facilitate hearing in the deaf or severely hard-of-hearing. Neural degeneration is a crucial impediment to the functional success of a cochlear implant. The present, first-of-its-kind two-dimensional finite-element model investigates how the depletion of neural tissues might alter the electrically induced transmembrane potential of spiral ganglion neurons. The study suggests that even as little as 10% of neural tissue degeneration could lead to a disproportionate change in the stimulation profile of the auditory nerve. This result implies that apart from encapsulation layer formation around the cochlear implant electrode, tissue degeneration could also be an essential reason for the apparent inconsistencies in the functionality of cochlear implants.     

Clad-modified fiber-optic magnetic field sensing characteristics of anion-doped bismuth manganite nanopowders

Journal of Materials Science: Materials in Electronics - It has been reported that magnetoelectric multiferroics are beneficial to magnetic field sensor applications and optoelectronic devices. The...     

PVD grown SnS thin films onto different substrate surfaces

Recent interests focus on tin mono sulphide as a potential candidate for an absorber layer in heterojunction solar cells. In the present investigation, SnS thin films have been deposited onto different substrates such as glass, ITO and Mo-coated glass substrate by thermal evaporation method. The compositional, microstructural and photoelectrochemical properties of the SnS films were analyzed depending upon the chemical nature of the substrates used. The SnS layers were polycrystalline with Herzbergite orthorhombic structure on all three substrates and had nearly stoichiometric elemental composition with a Sn/S ratio of ~1.01. The films grown on ITO and Mo-coated glass substrates exhibit (040) as preferred orientation whereas the films deposited on glass showed (111) plane as predominant. The layers were densely packed and well adherent to the substrate surface. The Raman spectra showed bands at 64, 163, 189 and 219 cm^?1, which corresponds to the single phase (SnS) composition of films. p-type conductivity of all the deposited films were determined by the photoresponse studies. The highest photoresponse for the films on the ITO substrate indicates their appropriateness for the solar cell application.