Greatly reduced leakage current and defect mechanism in atmosphere sintered BiFeO3–BaTiO3 high temperature piezoceramics

In current work, the effect of sintering atmospheres (N₂, air and O₂) on the structure, electrical properties, and defect mechanism of 0.8BiFeO₃–0.2BaTiO₃ lead-free piezoelectric ceramics has been investigated. X-ray diffractometer results indicated all the samples crystallized into the rhombohedrally distorted perovskite structure which was independent on the sintering atmospheres. Bi-containing impurity phases were observed in N₂ sintered samples while not appearing in other atmospheres. X-ray photoelectron spectrum analysis indicated more Fe²⁺ ions, which can result in high leakage current, were involved in N₂ sintered ceramics than that in O₂- and air sintered compositions. However, greatly reduced leakage currents were obtained in N₂ sintered ceramics which should be ascribed to the formation of secondary phases. The largest polarization and lowest leakage current were obtained in the sample sintered in N₂ (2 h), which owned the optimal ferroelectric, piezoelectric, and electromechanical properties with piezoelectric constant d ₃₃ = 98 pC/N, planar electromechanical coupling factors k _p = 26.1 %, remnant polarization P _r = 25.7 µC/cm², coercive field E _c = 74.6 kV/cm, and a high Curie temperature T _c = 632 °C, respectively.     

Miniaturized modified circular patch monopole antenna on ceramic-polytetrafluroethylene composite material substrate

A 0.22λ×0.29λ×0.03λ miniaturized modified circular patch monopole antenna on high permittivity ceramic-Polytetrafluoroethylene (PTFE) composite material substrate is presented. The proposed antenna is designed and investigated using 3D full wave high frequency electromagnetic simulator and fabricated using printed circuit board (PCB) prototyping machine. Impedance bandwidths (Reflection coefficient <?10 dB) of 26.76 % (5.0–6.3 GHz), 5.3 % (9.1–9.6 GHz) and 3.6 % (10.7–11 GHz) have measured. Average gains of 0.9 dBi, 3.68 dBi and 3.63 dBi measured at first, second and third band correspondingly. 87.3 %, 88.5 % and 93.1 % radiation efficiencies have achieved at three resonant frequencies 5.6 GHz, 9.5 GHz and 10.9 GHz respectively. The measured symmetric and nearly consistent radiation pattern makes the proposed antenna suitable for C band and X band applications. In this letter, the effects of dielectric properties of substrate material and design parameters have studied.     

Facile Synthesis of Fe3O4−SiO2 Nanocomposites for Wastewater Treatment

Water constitutes ≈70–90% of the organism's body by mass and is highly important for its survival. Water contains a variety of chemical contaminants introduced by various sectors, resulting in contamination that has a direct impact on the ecosystem. Various approaches are in practice to tackle these issues. Among these, semiconductor photocatalysis appears to be the cutting-edge technology for the degradation of wastewater contaminants. Herein, the fabrication of Fe₃O₄−SiO₂ nanocomposite via facile co-precipitation and Stober methods are reported. Various characterization techniques are employed for the structural elucidation, morphology, crystallinity, and stability of the as-prepared composite. The nanocomposite is employed in catalytic and photocatalytic applications toward the removal of methylene blue (MB) and methyl orange (MO) dyes from a comparative perspective. It is observed that the composite can remove about 93% of MB and 51% of MO within 7 and 6 h, respectively. These findings indicate that the nanocomposite has a higher MB removal effectiveness than the MO. This trend can be accredited to the difference in the chemical structure of both dyes. The nanocomposite is also evaluated for antioxidant and antileishmanial activity, and it is shown to be quite effective even at very low concentrations.     

Cobalt–Iron nanoparticles encapsulated in mesoporous carbon nanosheets: A one-pot synthesis of highly stable electrocatalysts for overall water splitting

Advancement of cost-effective, highly efficient and non-noble metal-based bifunctional electrocatalysts is considered an attractive approach to overcome the energy defect and environmental pollution challenges. Herein, this study presents a simple one-pot approach to synthesize cobalt-Iron nanoparticles encapsulated in mesoporous carbon nanosheets (Co₃Fe₇@CNSs) by the pyrolysis method. The Co₃Fe₇@CNSs-750/4h electrocatalyst exhibits a notable performance, low overpotential of 181 and 301 mV at a current density of 10 mA cm^?2 and small Tafel slope of 124.8 and 38.59 mV dec^?1, large active surface area 18.20 and 21.18 mF cm^?2, and low charge transfer resistance 4.92 and 9.42 Ω for hydrogen and oxygen evolution reactions, respectively, in 1.0 M KOH. Overall water splitting, with the set-up of two-electrode cells acquires the 10 mA cm^?2 of current density at 1.610 V in 1.0 M KOH. The combined structure of cobalt-iron nanoparticles encapsulated in carbon nanosheets; it could enhance the surface area and, provide more active sites that improve the overall catalytic activity. Not only this but also the synergistic effect due to different temperature treatments which significantly influenced the structural formation. However, the major involvement of this study is concerned with the production of economical non-noble metal-based electrocatalysts at an industrial scale for renewable energy to sustainability.     

Learning-detailed 3D face reconstruction based on convolutional neural networks from a single image

Neural Computing and Applications - The efficiency of convolutional neural networks (CNNs) facilitates 3D face reconstruction, which takes a single image as an input and demonstrates significant...     

GPU-based embedded edge server configuration and offloading for a neural network service

The Journal of Supercomputing - Recently, emerging edge computing technology has been proposed as a new paradigm that compensates for the disadvantages of the current cloud computing. In...     

An end-to-end deep learning model for human activity recognition from highly sparse body sensor data in Internet of Medical Things environment

The Journal of Supercomputing - Recognizing human activity from highly sparse body sensor data is becoming an important problem in Internet of Medical Things (IoMT) industry. As IoMT currently uses...     

Effects of Maillard reaction on physicochemical and functional properties of walnut protein isolate

Food Science and Biotechnology - In this study, the Maillard reaction (MR) of glucose was applied to improve the physicochemical and functional properties of walnut protein isolate (WNPI). The MR...