Hasil untuk "Electric apparatus and materials. Electric circuits. Electric networks"

Zheng Zhang, Mingxiang Liu, M. M. Ibrahim et al.

Andrea Sessa, Sebastiano De Stefano, Ofelia Durante et al.

Abstract 2D semiconductors are attracting considerable interest for neuromorphic electronics for their strong light–matter interaction, defect‐mediated charge dynamics, and suitability for energy‐efficient devices. Among them, tin diselenide (SnSe2) combines Earth abundance, environmental stability, high carrier mobility and persistent photoconductivity that make it a compelling candidate for multifunctional optoelectronic synapses. Here, we investigate multilayer SnSe2 field‐effect transistors and demonstrate gate‐tunable optoelectronic plasticity. Systematic measurements as a function of temperature, illumination power, and gate bias reveal that the device photoresponse is dominated by trap‐assisted photogating. The interplay between fast and slow recombination channels produces a persistent photocurrent (PPC) that can be finely tuned by the gate voltage. Negative gate bias enhances charge separation and prolongs PPC, enabling long‐term potentiation, while positive gate bias accelerates recombination and suppresses persistence, yielding short‐term memory. Furthermore, short gate voltage pulses enable reversible suppression of persistent photocurrent, allowing controlled switching between short‐ and long‐term memory states. Under repetitive optical stimulation, the devices exhibit cumulative learning and memory retention with high reproducibility. These results highlight SnSe2 as a robust platform for optoelectronic neuromorphic devices. By exploiting interfacial trap states and gate control, SnSe2‐based transistors emulate essential synaptic functionalities with excellent stability, offering new opportunities for 2D‐material‐enabled scalable neuromorphic hardware.

Xudong Wang, Guichen Teng, Xiangjian Meng et al.

Abstract Different from traditional ferroelectrics whose polarization stems from ionic displacements mediated by phonons, electronic ferroelectrics exhibit spontaneous polarization originating from polar electronic ordering. Such electronic mechanisms promise devices with ultrafast switching speeds, lower energy consumption, and enhanced resilience to fatigue and depolarization fields inherent in conventional ferroelectrics. While early candidates are restricted to rare oxides and organic charge‐transfer salts, emerging systems—particularly 2D van der Waals moiré heterostructures—have significantly broadened this materials landscape. This review comprehensively examines ferroelectrics governed by electronic mechanisms, categorizing them according to microscopic origins, including spin correlations, charge ordering, orbital interactions, charge‐transfer instabilities, and excitonic phenomena. Representative materials span multiferroics, molecular crystals, and engineered van der Waals architectures. Crucially, we evaluate whether their ferroelectricity qualifies as purely electronic—defined by the absence of ionic displacements during polarization reversal—synthesizing recent theoretical and experimental advances to establish a unified framework for this evolving paradigm.

Mohammed AMRANI, Djamel BENAZZOUZ, Smail ADJERID

This paper introduces a novel approach for real-time diagnosis of a purified water station designed for pharmaceutical applications. The water is produced using the reverse osmosis principle. Taking into account both the physicochemical properties required by international health regulations and the stringent standards of drug manufacturing, a diagnostic model based on artificial neural networks (ANN) is proposed. The developed intelligent monitoring system employs a multilayer ANN with gradient backpropagation (5-15-5). Its primary objective is to detect and localize potential faults within the water production process. The monitoring focuses on the physicochemical parameters of the purified water. Simulation results demonstrate effective fault detection, characterized by high accuracy, fast response time, and reliable performance.

Kiran A. Shila

We present a method for the design of an LNA input matching network using automatic differentiation (AD), a technique made popular by machine learning. The input matching network consists of a non-uniform suspended stripline transformer, directly optimized with AD-provided gradients. Compared to the standard approach of finite-differences, AD provides orders of magnitude faster optimization time for gradient-based solvers. This dramatic speedup reduces the iteration time during design and enables the exploration of more complex geometries. The LNA designed with this approach improves over a previous two-section uniform-line design, achieving an average noise temperature of (11.53 <inline-formula><tex-math notation="LaTeX">$\pm$</tex-math></inline-formula> 0.42) K over the frequency range of 0.7 GHz to 2 GHz at room temperature. We optimized the geometry in under 5 s, <inline-formula><tex-math notation="LaTeX">$40$</tex-math></inline-formula>x faster than optimizing with finite-differences.

Phil Thiel, Tobias Steinwedel, Philipp Raithel et al.

Regulatory authorities require product control for market release, especially for medical products due to legal regulations. Thus, end product control is conducted before drug market release. For real-time release in terms of Process Analytical Technology (PAT), product quality must be designed into the process. Process sensors are needed to monitor critical process parameters (CPP) for immediate control. Conventional sensors lack interfaces for disposable bioreactors, but new flow cell systems enable spectroscopic bioprocess monitoring via a bypass system. The flow cell is gamma-sterilized and clamped into a reusable holder, allowing spectroscopic techniques like turbidity, UV/VIS spectroscopy, and fluorescence.The cell setup and biocompatibility are presented, with in-vitro toxicity of various 3D printable materials evaluated per ISO 10993 to find suitable materials. Polyamide (PA), Acrylonitrile Butadiene Styrene (ABS) and Polymethyl Methacrylate (PMMA) were used for manufacturing flow cells and tested for in vitro biocompatibility. Results confirm the suitability of these materials and processes, with UV–VIS spectroscopy providing key insights. Selectivity and sensitivity for three different important bioprocess variables were evaluated and enables precise sensor system characterization across various analytes, advancing flow cell and sensor technology in biosensing and analytical chemistry.

Małgorzata Skorupa, Ethan Cao, Adrian Barylski et al.

Abstract In the pursuit of energy storage devices offering high power density, rapid charge and discharge rates, a layer‐by‐layer deposition approach is shown to improve the capacitive properties of conducting polymer‐based devices. This work describes the synthesis and characterization of a composite material based on poly(3,4‐ethylenedioxythiophene) (PEDOT) and poly(3,4‐ethylenedioxypyrrole) (PEDOP) for supercapacitor applications. PEDOT and PEDOP are sequentially electropolymerized using cyclic voltammetry to form bilayer structures, overcoming challenges associated with copolymerization. The evaluation of electrochemical performance of the PEDOT/PEDOP composite reveals superior areal capacitance (42.2 ± 2.8 mF cm−2 at the scan rate of 5 mV s−1) outperforming both homopolymers by up to 30%. Microscopic and spectroscopic surface analysis confirm the uniform coating of PEDOT/PEDOP and enhanced surface roughness resulting from the formation of 3D nanostructures, contributing to improved electrochemical performance. Further electrochemical impedance spectroscopic analysis demonstrates low charge transfer resistance (25 ± 8 Ω) and high energy density with respect to the area of the electrode (3.53 ± 0.3 µWh cm−2 at 55 µW cm−2), making PEDOT/PEDOP composite a promising material for high‐performance supercapacitors.

Djamila TALAH, Mohammed TSEBIA, Hamid BENTARZI et al.

The advanced technologies in the combined cycle power plants offer more effectiveness and lower environmental effects compared to the conventional systems. Fuzzy logic control, one of the frequently advanced controllers, may well improve the performance of the control system in the power plant. This study focuses on improving a governing control system by using a fuzzy logic controller. Thus, a combined cycle gas turbine plant has been modeled and simulated on MATLAB/Simulink, and a fuzzy logic controller was implemented. The simulation results are compared with those of a conventional PID controller tuned by the Ziegler-Nichols method.  

Siwei Wang, Xuemeng Hu, Baifan Qian et al.

Abstract Because of the limitations of the von Neumann structure and transistor size scaling, it is important to find new materials to build ultra‐thin artificial synapse devices. Doped In2O3 has attracted a lot of research due to its excellent on/off ratio, high mobility, and large on‐state current. In this paper, an ultrathin Sn‐doped In2O3 (ITO) is used as a semiconductor channel, and ferroelectric material HZO is used as a gate stack to fabricate synaptic transistors. The device has a great on/off ratio ≈108 with a memory window of 1.73 V. The device successfully simulates the characteristics of the human brain. Besides, a conductance modulation by ferroelectric polarization illustrates linear potentiation and depression characteristics. The devices achieve good linearity of 0.45 for potential and 0.73 for depression and low asymmetry of 0.89. Based on the MNIST and sign language MNIST database, ITO FeFETs successfully recognize numbers and sign languages. This work demonstrates the potential of ITO in building high‐performance artificial synaptic devices.

Naim Shandi, Jason M. Merlo, Jeffrey A. Nanzer

We demonstrate distributed beamforming and beamsteering from a six-node distributed phased array using fully wireless coordination with decentralized time synchronization. In wireless applications such as distributed beamforming, high-accuracy time synchronization across the array is crucial for high coherent gain. The decentralized time synchronization method employed is based on the average consensus algorithm and the two-way time transfer method presented in our previous work, which achieved picosecond-level time synchronization with a cabled frequency reference. The system presented in this paper utilizes a centralized wireless frequency transfer method to achieve wireless frequency syntonization in a fully wireless coordination and a distributed computing system architecture. We experimentally evaluate system performance through beamforming and beamsteering to a receiver 16.3 m away from the six-node non-uniformly distributed antenna array, achieving an average coherent gain of 98&#x0025; of the ideal gain at a carrier frequency of 1.05 GHz. The average time synchronization accuracy achieved was less than 36 ps.

Tobias Verheugen Hvidsten, Maximilian Roithner, Fred Espen Benth et al.

Electric vehicle batteries have a proven flexibility potential which could serve as an alternative to conventional electricity storage solutions. EV batteries could support the balancing of supply and demand and the integration of variable renewable energy into the electricity system. The flexibility potential from electric vehicles, in distinction to conventional battery storage, depends on the vehicle user's willingness and opportunity to make their vehicle available for flexibility. This rate of participation is often not considered in studies, despite the impact electric vehicle flexibility could have on the electricity system. This work presents a modelling study of the Norwegian electricity system, demonstrating how a future net-zero electricity system can benefit from electric vehicles in terms of integrating renewables and balancing supply and demand, while considering the rate of participation. Our findings show electric vehicles' potential to eliminate the need for stationary battery storage with just 50% participation in vehicle-to-grid. We find that the flexibility of electric vehicles contributes to relative reductions in the total cost of the electricity system by almost 4% and 15% assuming 100% participation in flexible charging and vehicle-to-grid, respectively.

Mohammad Hassan Bahmani, Mostafa Esmaeili Shayan, Davide Fioriti

N. Kamboj, Ayan Dey, Sunita Birara et al.

The sustainable chemical energy of H2O2 as a fuel and an oxidant in an advantageous single-compartment fuel cell design can be converted into electric energy, which requires molecular engineering to design suitable cathodes for lowering the high overpotential associated with H2O2 reduction. The present work covers the synthesis and structural characterization of a novel cathode material, [FeIII2(hnmh-PLY)3] complex, 1, designed from a PLY-derived Schiff base ligand (E)-9-(2-((2-hydroxynaphthalen-1-yl)methylene)hydrazineyl)-1H-phenalen-1-one, hnmh-PLYH2. Complex 1, when coated on the surface of a glassy carbon electrode (GC-1) significantly catalyzed the reduction of H2O2 in an acidic medium. Therefore, a complex 1 modified glassy carbon electrode was employed in a one-compartment H2O2 fuel cell operated in 0.1 M HCl with Ni foam as the corresponding anode to produce a high open circuit potential (OCP) of 0.65 V and a peak power density (PPD) of 2.84 mW cm-2. CV studies of complex 1 revealed the crucial participation of two Fe(III) centers for initiating H2O2 reduction, and the role of coordinated redox-active PLY units is also highlighted. In the solid state, the π-conjugated network of coordinating (hnmh-PLY) ligands in complex 1 has manifested interesting face-to-face π-π stacking interactions, which have helped the reduction of the complex and facilitated the overall catalytic performance.

Li Yun-Heng, Yu Ke, Zhu Tian-Yu et al.

Optical bistable states exhibit great potentials in applications in photonic integrated circuit and photonic neural network. However, the traditional optical bistable state will be influenced by the system disorders, which are not suitable for application. In this paper, we investigate the topological bistable states in a layered structure with center inversion symmetry consisting of alternating layers of high index material TiO2 and low index material SiO2. In topological mode, the electric field is highly localized in the inversion center of the layered structure (also known as the interface) and exponentially decays into the bulk. Thus, when the nonlinear permittivity is strategically introduced in those layers, nonlinear phenomena such as the bistable state appears. Finite element numerical simulations reveal the optimal bistable state appears when the layer period is 5 with a threshold power around 1.2 W/m. Benefiting from the topological feature, such bistable state persists when the random perturbations are introduced in the layer thickness and refractive index. Finally, we apply the bistable states into a photonic neural network. The bistable function shows similar prediction accuracy over a variety of learning tasks with the classic activation function Relu and sigmoid. These results suggest a novel avenue towards the insertion of the highly robust optical bistable states from topological layered structure into photonic neural network.

Nourhan Elsayed, Saeedeh Makhsuci, Mihai Sanduleanu

Using the stacking technique in CMOS technology for Power Amplifiers (PAs), allows the use of a higher supply voltage. This facilitates achieving a higher voltage swing, and delivering more output power while maintaining a high efficiency. This work presents an improved 2-stacked cascode class-E PA at 28 GHz. Unlike existing topologies, a switching input signal is not only applied at the input transistor, but also at the cascode transistor with an added delay. The design was fabricated in 22 nm FDSOI CMOS technology by GlobalFoundries that offers high performance especially at mm-wave frequencies. Measurement results of the cascode Class-E Power Amplifier achieves a peak PAE of 28&#x0025;, and 41&#x0025; DE. The switched-cascode topology showed an improved peak PAE of 35&#x0025; and DE of 45&#x0025;. Measured power gain was 8.5 dB with saturated output power (P_sat) of 13 dBm. This work reports the best Drain Efficiency (DE) and FoM for a fully integrated PA at 28 GHz in 22 nm FDSOI.

A. Sreekanth Reddy, G. Nageswara Reddy

In this paper, two linear modeling techniques are presented for regulating the liquid height in two tank - two variable system (TT-TVS). Initially, the nonlinear dynamics of TT-TVS are linearized using the Taylor series linearization technique. However, this method reveals that some parameters of TT-TVS are inexact, necessitating the adoption of system identification techniques or mathematical approaches to accurately identify the linear dynamics. To address this, two new approaches are proposed: (i) a mathematical approach utilizing real-time input-output data, and (ii) a Linear Variable Parameter Transfer Function (LVPTF) model identification approach, which employs real-time data and MATLAB curve fitting tool. A comparative analysis between the proposed identification techniques and existing methods from the literature is also presented. The results indicate that the LVPTF modeling technique offers superior accuracy in identifying the linear dynamics of TT-TVS.

R. Karpagam, J. Lydia, R. Murugan et al.

The magnetic field distribution in the rails is a crucial factor in comprehending railgun behaviour. The projectile's rapid movement has a significant impact on the magnetic field. If the dispersion of the magnetic field conclusions regarding the conductors are known suitable methods can be used to sketch the magnetic field distribution. The railgun operates on the premise that a high current flow through the rails and armature will create a strong magnetic field. As a result, before designing magnetic shielding, it is necessary to study the features of the magnetic field distribution. The shape of rail and armature cross section is very essential in rail gun design as it determines the magnetic field distribution over rail and armature. The rail gun geometries with rectangular, convex and concave rail cross-sections are compared and simulated using finite element method (FEM). This method is used to determine the magnetic field distribution over rail and armature by sweeping armature position for different rail cross sections. It is observed that for the different rail/armature shapes like rectangular, convex and concave shapes, the C shaped convex armature possesses strong magnetic fields with minimum current density concentration at the throat and trailing end of the armature. From simulation, it can be shown that the magnetic flux density is a descending function of the central angle. The electromagnetic (EM) rail gun launching mechanism was therefore proven to be compatible with the circular concave armature.

Haiyan Kuang, Xiang He, V'yunov Oleg et al.

Abstract In this work, a new type of ternary lead‐free ferroelectric ceramics (1−x)[0.94(Bi0.5Na0.5)TiO3‐0.06BaTiO3]‐xCa(Mg1/3Nb2/3)O3 is synthesized by traditional solid‐state reaction method (x = 0.02, 0.04, 0.06, 0.07, 0.08, 0.10, and 0.15). No phase transition is detected and all ceramics exhibited the perovskite structure consisting of the rhombohedral (R3c) and tetragonal (P4bm) phases. By increasing the Ca(Mg1/3Nb2/3)O3(CMN) content, the average grain size shows a slight change. More specifically, the grain size is 1.00 µm when x < 0.10 and then increases to 1.20 µm in x = 0.10 and 0.15. When x = 0.07, an optimum energy storage performance with recoverable energy density (Wrec) of 4.13 J cm−3 is achieved under an electric field of 340 kV cm−1. At the same time, it exhibits excellent pulse performance at 25 °C, with an effective discharging time (t0.9) of 3.2 ns and a discharge energy density (WD) of 0.61 J cm−3, suggesting a fast charging–discharging rate. In addition, the current density (CD) and power density (PD) are 92.31 A cm−2 and 6.46 MW cm−3, respectively. Overall, the 0.93[0.94(Bi0.5Na0.5)TiO3‐0.06BaTiO3]‐0.07Ca(Mg1/3Nb2/3)O3 ceramics is considered a competitive candidate for the development of high‐energy storage capacitors and pulse‐power devices.

Hanwei Wang, Yang Zhao

Enantioselective interactions of chiral molecules include distinct absorptions to opposite-handed circularly polarized light, known as chiral absorption. Traditionally, chiral absorption has been primarily attributed to electric dipole and magnetic dipole interaction with molecular chirality. However, this approach falls short for large molecules that support high-order multipolar components, such as electric quadrupole moment. Here, we introduce a theoretical model to study the chiral absorption of large molecules in the presence of plasmonic nanostructures. This model considers both electric dipole-magnetic dipole interaction and electric dipole-electric quadrupole interaction enhanced by a resonant structure. We numerically study such interactions of the chiral molecular solution in the vicinity of a nonchiral plasmonic nano-resonator. Our results show the distinct spectral information of the chiral media on- and off-resonance of the resonator.

D. Quang To, Federico Garcia-Gaitan, Yafei Ren et al.

Magnons offer a promising path toward energy-efficient information transmission and the development of next-generation classical and quantum computing technologies. However, methods to efficiently excite, manipulate, and detect magnons remain a critical need. Here, we show that magnons, despite their charge-neutrality, can induce electric polarization as a result of both their spin and orbital moments. We demonstrate this by calculating the electric polarization induced by magnons in two-dimensional (2D) honeycomb antiferromagnets. The electric polarization becomes finite when the Dzyaloshinskii-Moriya Interaction (DMI) is present and its magnitude can be increased by symmetries of the system. We illustrate this by computing and comparing the electric polarizations induced by the magnon Nernst effects in 2D materials with Néel and Zigzag ordering. Our findings show that in the Zigzag order, where the effect is dominated by the magnon orbital moment, the induced electric polarization is approximately three orders of magnitude greater than in the Néel phase. These findings reveal that electric fields could enable both detection and manipulation of magnons under certain conditions by leveraging their spin and orbital angular moment. They also suggest that the discovery or engineering of materials with substantial magnon orbital moments could lead to more practical use of magnons for future computing and information transmission device applications.