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Recently, metal-supported solid oxide fuel cells (MS–SOFCs) have been in the spotlight again for their design, thanks to their inexpensive materials, robustness, resistance to thermal cycling, and benefits of manufacturability. Hydrogen energy electrochemical devices, like MS–SOFCs, have a lot of potential. They are very ideal substitutes for solid oxide fuel cells (SOFCs) that utilize electrolytes or ceramic electrodes as their carrier basis, because of their greater durability, mechanical stability, heat cycle resistance, and rapid startup time. Even though MS–SOFCs have several advantages over conventional ceramic-based SOFCs, researchers are still struggling to perfect them due to issues such as selecting the appropriate metal-based material for the electrodes (anode, electrode) and comprehending how they deteriorate. This limitation might be evaded by optimizing the pore former filling and the diameter of the metallic supports (130–250$\mu$m). Optimization methods, such as particle swarm optimization, as well as penetration cycle numbers (1–15), as well as the impacts of fire temperatures (400–900^∘C), were investigated to aid in optimizing the catalyst infiltration procedure. The enhanced cell outperformed its original performance by a factor of three, reaching an ideal energy density of 0.9W cm${}^{-2}$ at 700^∘C when powered by hydrogen. The improved cells had a 2% degradation rate per 100h at 550^∘C, a 4.5% degradation rate at 600^∘C, and a 5.5% degradation rate at 700^∘C. We used electrochemical impedance spectroscopy and scanning electron microscopy to look at the catalyst’s mass shipping, coarsening, and chromium poisoning.

A new method to fabricate microfluidic channel which has metal electrodes on side wall is presented. Three dimensional electrode patterns were deposited through the shadow mask on highly recessed surfaces of microchannel. Polymer microchannel was fabricated using polymer molding technique. Shadow mask for electrode patterning were fabricated using MEMS process. Electrodes were patterned on side wall of microchannel using shadow effects occurring at angled evaporation through shadow mask. The electrodes on side walls facing each other are expected to provide more sensitivity at bio-analysis devices based on impedance variation.

Using novel numerical techniques, this paper estimates the effect of EHD force on ferrofluid treatment. Iron oxide additives of various nanoscale forms and dimensions are added to the operating fluid. Because the percentage of nanoparticles exceeds 0.06 and the slip velocity is disregarded, the features of the carrier fluid were modified using an empirical model. The left and bottom surfaces of the moving walls had the highest temperatures and voltages. A non-Darcy presumption was that the region was permeable. A combined FVM and FEM method was utilized to solve this issue. Due to the application of an electric force, the nanofluid is able to move more quickly, and two primary vortices combine to form a single, stronger vortex. As voltage increases, Nu increases by approximately 125.52%. Utilizing greater permeable medium results in a stronger wall collision and a 113.29% increase in Nu. Nu increases by approximately 3.69% when a nanoparticle with a greater shape factor than the sphere is utilized.

ZnS nanoparticles (NPs) are prepared by co-precipitation method using ethylene diamine tetra-acetic acid as a stabilizer and capping agent. The structural, morphological and optical properties of as-synthesized NPs are investigated using X-ray diffraction, scanning electron microscope, Fourier transform infrared spectroscopy, ultraviolet-visible (UV-Vis) absorption, and photoluminescence spectroscopy. The X-ray diffraction pattern exhibits a zinc-blended crystal structure at room temperature. The particle size was found to be in the range of 22.22 nm. The ultraviolet absorption spectrum shows the blue shift in the bandgap due to the quantum confinement effect. The photoluminescence spectrum of ZnS NPs shows a blue visible spectrum. The template of the cyclic voltammetry contour demonstrated a strong rate suggesting that the ZnS nanostructure electrode has a reduced polarization effect. The above studies have provided resplendent efficiency and proven that ZnS NPs can be used as a prominent material for supercapacitor applications.

This paper presents a 65nm CMOS low-power, highly linear variable gain amplifier (VGA) suitable for biomedical applications. Typical biological signal amplitudes are in the 0.5–100mV range, and therefore require circuits with a wide dynamic range. Existing VGA architectures mostly exhibit a poor linearity, due to very low local feedback loop-gain. A technique to increase the loop-gain has been explored by adding additional feedback to the tail current source of the input differential pair. Stability analysis of the proposed technique was undertaken with pole-zero analysis. A prototype of Analog Front End (AFE) has been designed to provide 25–50 dB gain, and post-layout simulations showed a 15dB reduction in the harmonic distortion for 20mV pk-pk input signal compared to the conventional architecture. The circuit occupies 3,108$\mu$m² silicon area and consumes 0.43 $\mu$A from a 1.2V power supply.

The dielectric properties of Ba_0.6Sr_0.4TiO₃ (BST) thin films deposited using SrRuO₃ (SRO) materials as bottom electrode were compared with those of the films grown using La_0.5Sr_0.5CoO₃ (LSCO) materials as bottom electrode. X-ray diffraction scanning revealed that the two kinds of films could be epitaxially grown in pure single-oriented perovskite phases and atomic force microscopy showed that the root mean square roughness of BST/SRO films were similar to BST/LSCO films. The dielectric properties of the BST/SRO and BST/LSCO thin films were measured at 10 kHz and 300 K with a parallel-plate capacitor configuration. Compared with BST/LSCO, the dielectric tunability for BST/SRO films slightly decreased, while the loss decreased synchronously. The figure of merit factor value increases from 25.67 for BST/LSCO films to 48.76 for BST/SRO films under an applied voltage of 6 V. The leakage current density of the thin films at a positive voltage of 2 V decreases from 2.41 × 10^-7A/cm² for BST/LSCO to 8.41 × 10^-8A/cm² for BST/SRO. This phenomenon is ascribed to the smaller strain induced in BST/SRO materials.

Heavy metal pollution endangers seawater and there is urgent need for the development of effective detectors that can provide warning of heavy metal pollution. Anodic stripping voltammetry is applicable for the detection of heavy metal pollution in sea water, but it suffers from two problems that are associated with the mercury electrode used: one is insufficient sensitivity and the other is secondary pollution caused by toxic mercury. In this work, we employed boron-doped diamond electrode as an alternative to mercury electrode for the detection of heavy metals. The BDD electrode was fabricated and its electrochemical properties were ascertained. The results of this work showed that: (1) the electrode prepared has a wide electrochemical window (4.2 V) and low background current ($3\pm 2\mu$A). (2) multiple heavy metals (Pb${}^{2+}$, Cd${}^{2+}$, Zn${}^{2+}$ and Cu${}^{2+}$) in seawater samples are detected simultaneously with the optimized electrode, with high sensitivity and good repeatability. (3) the repeatability of the detection meets the values stipulated in the national standard. The detection period is less than 15min, and in situ monitoring of heavy metals in seawater can be achieved by automatic sampling and wireless data transmission.

Pure copper, copper-based alloys, brass, graphite and steel are the most common tool materials for the electrical discharge machining (EDM) process. The electrode material, which exhibits good conductivity to heat and electricity and possesses better mechanical and thermal properties, is preferred for EDM applications. The major problem with conventional electrodes like copper and graphite is their low wear resistance capacity. This study is on the fabrication of Cu–SiC composites as an electrode of EDM with improved wear characteristics for machining of hardened D2 steel which is widely used in die formation. Powder metallurgy route was used to fabricate the samples which was further followed by three-step sintering process. Copper metal was used as a matrix element which was reinforced with SiC in volume fractions of 10%, 15% and 20%. Based on the desirable properties for the EDM tool, the best composition of Cu–SiC composite tool tip was suggested and was further used for machining of D2 steel. The performance of newly developed Cu–SiC composite electrode in terms of surface roughness (SR), material removal rate (MRR) and tool wear rate (TWR) was explored, and it was compared with the pure copper electrode. Pulse on-time, pulse off-time and the input current were selected as the input process parameters. Result reveals that the TWR and SR were decreased by 12–18% and 10–12%, whereas the MRR was increased by 9–28% for Cu–SiC composite tool as compared to the pure Cu electrode. Adequacy of the results was checked by statistical analysis. The surface texture of tool and machined surface was analyzed using scanning electron microscopy (SEM). SEM micrograph revealed that surface cracks on composite tool tip were lesser than pure Cu tool tip, whereas the work surface was rough while machining with the copper tool surface. Therefore, the result indicates that the newly developed Cu–SiC composite tool can be used for machining of hard materials with EDM.

Incessant streak of unsuccessful attempts to synthesize low cost graphene with larger flake size and purity is frequently reported. Any reported methods that result in few layers of graphene with minimal contamination are definitive to exist. In this work, graphene was prepared economically from source of “paper” and detailed investigation was done on the effect of synthesizing parameters like paper source, temperature and amount of urea in the formation of graphene. This is a cost effective method, in which the paper that we use in our daily life was carbonized with the help of urea at a temperature of 850${}^{\circ }$C under N₂ atmosphere. The paper source was varied, shape of the paper was altered and the graphene paper with large surface area was synthesized without smudging and the prepared graphene paper was analyzed by X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) for its structural, morphological investigation. To test the supercapacitance performance, electrochemical behavior was investigated in 6M KOH electrolyte. The specific capacitance of 1122F/g was obtained at 5mV/s scan rate. Chronopotentiometry curves showed an excellent cyclic stability with higher charge/discharge duration and hence could be used for electrochemical supercapacitor applications.

This study’s objective is to prepare and characterize a ZnO-rGO composite for use in supercapacitors. The hydrothermal method was used to successfully prepare ZnO and ZnO-rGO. Characterization of the prepared materials was carried out using X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), and ultraviolet-visible (UV–Vis) spectrometers. The electrochemical properties of the ZnO and ZnO-rGO electrodes were examined using cyclic voltammetry (CV) and impedance spectroscopy. The specific capacitance of the ZnO-rGO composite electrode in 1M NaOH as an electrolyte was 293.37F/g at the scan rate of 5mV/s. As a result of the low equivalent series resistance and improved ion diffusion produced by ZnO and rGO working together, the ZnO-rGO nanoparticles electrode has a higher super capacitance. The result achieved a higher energy density of 39.93Wh/kg and a power density of 54.45kW/kg. These findings demonstrated the significance of rGO-based composites in the development of high-performance energy storage systems as well as their enormous potential for improvement.

Alkali metal-ion batteries (Li/Na/K) are important energy storage systems due to their ample elemental reserves and suitable working voltage. Many electrode materials had been developed and utilized to seek higher capacity and cycle stability. Single atom materials (SAMs) have high active atom dispersion and are very promising. The active metal sites can promote the diffusion kinetics and adsorption of lithium, sodium and potassium ions, which plays a key role in improving the capacity and cycling-stability. However, the experimental investigation of SAMs in Li/Na/K is still in its infancy stage. In this mini review, the structural design and electrochemical performance of single atom electrode materials in Li/Na/K are systematically summarized. The current challenges and potential research directions of designing SAMs for high-performance electrodes are also discussed.

A graphene and carbon nanotube (CNT) array composite was synthesized by chemical vapor deposition (CVD) and chemically treated after synthesis, yielding a novel corrugated structure, visually similar to a mushroom gill. This binder-free hybrid material was used to make an electrode that may find application in energy storage devices, such as supercapacitors. The electrode performance of the corrugated graphene/CNT array composite (CGCC) was compared to that of commercial glassy carbon. The results of the comparison are presented here, along with suggestions for further development of the CGCC electrode.

To produce the free-standing electrodes, a binder-free direct growth method was employed for electrode fabrication. A NiCo₂O₄@Ni-MOF (metal–organic framework) composite was synthesized using a one-pot hydrothermal method. Initially, a NiCo₂O₄ nanowire array was cultivated on Ni foam, serving as a connecting bridge to ensure robust adherence of the Ni-MOF to the substrate. The structures of NiCo₂O₄ nanowire arrays exhibit the capacity for numerous redox reactions. Hybridizing MOF with transition metal oxide (TMO) nanoarchitectures can significantly alleviate the small specific surface area and aggregation tendency of TMOs. The highest energy storage capacity was obtained when the ratio of nickel to terephthalic acid (TPA) was 4:1. NiCo₂O₄@Ni-MOF (Ni:$\mathrm{\text{TPA}}=4$:1) exhibited a high storage capacitance of 1700F/g. The integration of MOF with TMO nanoarchitectonics as materials for supercapacitor electrodes can enhance porous structure and facilitate diffusion during both charging and discharging processes.

In the analysis of a surface acoustic wave resonator for modeling and design, wave velocity considering the influence of complications of the structure is a very important parameter. Currently, solutions of surface acoustic wave velocity are mainly obtained from the simplified semi-infinite model. In this study, we analyze surface acoustic waves in a finite isotropic substrate with periodic electrodes by using the two-dimensional theory for finite elastic solids. Numerical examples, which use isotropic materials as substrates, show that surface acoustic waves will have a lower velocity with the increase of electrode thickness. When the thickness of electrode is zero, surface acoustic wave will have the same velocity with the corresponding semi-infinite substrate case.

The analyses of surface acoustic waves propagating in finite elastic solids are mainly done with the simplified semi-infinite model. In this study, we analyze the characteristics of surface acoustic waves in finite anisotropic substrates with periodic electrodes by using the two-dimensional theory for finite elastic solids. Through the solutions of surface acoustic wave velocities, we find that surface acoustic waves will have a lower velocity with the increase of periodic electrode thickness. When the thickness of periodic electrode is zero, surface acoustic wave will have the same velocity with the corresponding semi-infinite substrate case. The analytical model we use is closer to the actual surface acoustic wave resonators, and at the same time the finite sizes of structures and the effect of electrodes for their layout, size, and material properties are considered. The method and results from this study will have important practical applications in the analysis of surface acoustic wave resonator for modeling and design.