Hasil untuk "Plasma engineering. Applied plasma dynamics"

Yuvaraj K, Sanam Narayana Reddy

This paper presents a substrate-dependent performance evaluation of a defected ground structure (DGS)-integrated multiband hexagonal microstrip patch antenna operating in the 22–28 GHz millimetre-wave band for 5G FR2 applications. To examine the influence of dielectric properties on electromagnetic behaviour, the same antenna geometry is implemented on three commonly used substrates—Duroid (relative permittivity εr ≈ 2.2, loss tangent tanδ ≈ 0.0009), Rogers (εr ≈ 2.94, tanδ ≈ 0.0012), and FR4 (εr ≈ 4.4, tanδ ≈ 0.02). A controlled substrate-based comparison is conducted with respect to the reflection coefficient, impedance bandwidth, gain, and radiation efficiency. The results indicate that substrate characteristics significantly affect resonance depth, impedance stability, and radiation performance at millimetre-wave frequencies. The Duroid-based configuration achieves S₁₁ below −32 dB, peak gain of 8–8.5 dBi, and high radiation efficiency due to reduced dielectric loss. The Rogers substrate exhibits stable multiband behaviour with moderate gain, whereas the FR4-based design shows reduced resonance depth and lower gain due to increased dielectric dissipation. By maintaining identical geometry across all substrates, the study isolates the direct impact of dielectric constant and loss tangent on modal excitation and efficiency degradation in the 22–28 GHz band. The presented analysis supports informed substrate selection for compact multiband mmWave antenna designs in next-generation wireless systems.

Chao Dai, Zheng Zhang, Nailong Liu et al.

The accumulation and migration of space charges severely limit the application of polymer insulation in high-voltage direct current systems. This study investigates epoxy resin composites modified with polydopamine-functionalized boron nitride nanosheets (PDA@BNNS), where a two-step process involving plasma hydroxylation and subsequent polydopamine coating was employed to enhance the filler-matrix interface. The composites were characterized using pulsed electro-acoustic measurements, direct current (DC) conductivity tests, surface potential decay, and broadband dielectric spectroscopy. Results show that the 3 wt. % PDA@BNNS composite exhibits optimal performance, suppressing space charge accumulation and reducing the stored charge amount by approximately 36% at 20 kV/mm compared to pure epoxy. The effective charge injection barrier at 20 kV/mm increases from 1.12 eV (pure epoxy) to 1.35 eV (3 wt. % composite), and the conduction activation energy rises to 0.70 eV. The introduction of deep traps not only modifies the trap-limited space charge-limited current but also fundamentally alters the bulk conduction mechanism. To further elucidate this, the temperature-dependent conductivity was analyzed. Charge transport transitions to a three-dimensional variable-range hopping mechanism dominated by deep traps. A multi-mechanism synergistic model is proposed, encompassing barrier enhancement, deep trapping, potential quantum confinement, field homogenization, and relaxation optimization. This interface engineering strategy provides an effective approach for developing high-performance DC insulation materials.

Nesrine Labdouni, Djilali Benyoucef, H. Tebani

The paper presents a comprehensive numerical investigation of dielectric barrier discharges (DBDs) operating in atmospheric pressure air (N₂–O₂–Ar) containing NO concentrations between 2.5% and 10% is presented for plasma assisted NOₓ mitigation. A one-dimensional fluid model is developed to describe the discharge dynamics and plasma chemical interactions under applied voltages of 8–12 kV and excitation frequencies of 2–4 kHz. The influence of voltage amplitude and frequency on electrical characteristics and NOₓ removal efficiency is systematically analyzed. A representative operating condition (10% NO, 10 kV, 3 kHz) is examined in detail to elucidate the temporal evolution of voltage and current and the spatial distributions of electrons, ions, excited species, and neutral particles involved in NO dissociation pathways. The results provide improved insight into the reaction kinetics governing NO degradation in air plasma and offer practical guidance for optimizing DBD-based environmental remediation systems. Copyright © 2026 by Authors, Published by BCREC Publishing Group. This is an open access article under the CC BY-SA License (https://creativecommons.org/licenses/by-sa/4.0).

Mohammed S. Ghayad, H. Ahmed, N. Badra et al.

S. Sato, N. Ohnishi

Dielectric barrier discharge (DBD) plasma actuators are devices that actively control the airflow using nonequilibrium atmospheric-pressure plasmas, showing promise for practical applications in the field of aerospace engineering. Numerous studies have revealed the dynamics of surface discharge and the process of generating electrohydrodynamic (EHD) force in detail. The performance of DBD plasma actuators has improved continuously over the past 20 years. However, there is a need for further improvement in EHD force generation to enable the practical applications of DBD plasma actuators. In this review, we provide insights that contribute to the development of a high-performance DBD plasma actuator by reviewing previous studies focused on revealing the surface discharge and EHD force generation processes. The foundations of the discharge process in DBD plasma actuators are briefly described from the perspectives of experiments and numerical simulations. We also reviewed various strategies for improving EHD force generation by optimizing the geometric structure and the applied voltage waveform as well as by controlling the surface charge accumulation. Improving EHD force generation and its efficiency is a fundamental research area to realize the practical applications of a novel active airflow control device that uses nonequilibrium plasmas.

F. Faraji, M. Reza, A. Knoll et al.

Computationally efficient reduced-order plasma models, able to predict plasma behavior reliably and self-consistently, have remained unachievable so far. The need for these models has nonetheless continuously increased over the past decade for both fundamental studies and engineering applications. With the increase in computational power in recent years and the emergence of several approaches that lower the computational burden of generating extensive high-fidelity plasma datasets, data-driven (DD) dynamics discovery methods can play a transformative role toward the realization of predictive, generalizable and interpretable reduced-order models (ROMs) for plasma systems. In this work, we introduce a novel DD algorithm—the ‘Phi Method’—for the discovery of discretized systems of differential equations describing the dynamics. The success and generalizability of Phi Method is rooted in its constrained regression on a library of candidate terms that is informed by numerical discretization schemes. The Phi Method’s performance is first demonstrated for a one-dimensional plasma problem, representative of the discharge evolution along the azimuthal direction of a typical Hall thruster. Next, we assess the Phi Method’s application toward parametric dynamics discovery, i.e. deriving models that embed parametric variations of the dynamics and in turn aim to provide faithful predictions of the systems’ behavior over unseen parameter spaces. In terms of salient results, we observe that the Phi-method-derived ROM provides remarkably accurate predictions of the evolution dynamics of the involved plasma state variables. The parametric Phi Method is further able to well recover the governing parametric partial differential equation for the adopted plasma test case and to provide accurate predictions of the system dynamics over a wide range of test parameters.

M. Shakeel, Abdul Saboor, F. Alshammari et al.

The main purpose of this work is to apply the new extended direct algebraic (nEDA) method to achieve exact traveling wave solutions for the nonlinear time-fractional modified Korteweg–de Vries Kadomtsev Petviashvili (mKdV-KP) equation. The model incorporates a fractional term utilizing the beta derivative, aiming to attain soliton solutions applicable to distinct physical processes such as ion-acoustic waves and plasma physics. The novelty of this research work lies in its application to the time-fractional mKdV-KP equation, along with the analysis of bifurcation, chaos, Lyapunov exponent analysis, sensitivity analysis and multi-stability to study the dynamical behavior of the system. The nEDA method is applied to achieve distinct soliton solutions for the governing model for the first time. These solutions are further examined by utilizing graphical simulations in the form of two-dimensional and three-dimensional surface plots yielded by MATHEMATICA- $11$. The dynamical characteristics and physical structure of the solutions are investigated, presenting their relevance and accuracy. The solutions are applied to real-world systems like biological processes, diffusion, solid-state physics and plasma phenomena. Notably, the analysis of bifurcation, chaos and sensitivity provides key insights into the stability and behavior of the model, emphasizing the novelty of the results. While the investigation presents a theoretical framework, further experimental verification and practical implementation of the soliton solutions are needed to understand their applicability in real-world systems better. Future work could explore more complex fractional models to gain deeper insights into the nonlinear dynamics of various systems. This paper applies an nEDA method for the first time to the time-fractional mKdV-KP equation, providing new exact soliton solutions such as bright-dark, lump-kink and periodic.

Shengke Zhang, Jing Wang, Einly Lim et al.

Mohammed Saleh Alshaikh

The performance of Organic Solar Cells (OSCs) is intrinsically linked to the molecular, electronic, and structural properties of donor and acceptor materials. This study employs various machine learning techniques, namely the Generalized Regression Neural Network (GRNN), Support Vector Machine (SVM), and Tree Boost, to predict key performance metrics of OSCs, including power conversion efficiency (PCE), short-circuit current density (JSC), open-circuit voltage (VOC), and fill factor (FF). The models are trained and evaluated using an experimentally reported dataset compiled by Sahu et al. Correlation analysis demonstrates that material characteristics such as polarizability, bandgap, dipole moment, and charge transfer are statistically associated with OSC performance. The predictive performance of the GRNN model is compared with that of the SVM and Tree Boost models, showing consistently lower prediction errors within the considered dataset. In addition, sensitivity analysis is performed to assess the relative importance of the predictor variables and to examine the influence of kernel functions on GRNN performance. The results indicate that machine learning models, particularly GRNN, can serve as effective data-driven tools for predicting the performance of organic solar cells and for supporting computational screening studies.

Suman Lata Yadav

The concept of life skills is related to the way of life that emphasises the mutual exchange of knowledge, attitudes, and interpersonal skills in education. Its objective is to develop diverse skills among students and prepare them to face life’s challenges with determination. The World Health Organization has defined life skills as “the positive behaviours and tendencies that enable a person to adapt in day-to-day life.” Life skills are the abilities that enable a person to adapt and exhibit positive behaviour, allowing them to deal effectively with the problems and challenges of daily life. Life is a unique gift. Therefore, by equipping life with various skills, happiness, peace, and prosperity are created. In this research, with the objectives of the study in mind, an analytical examination of life skills among secondary-level students has been conducted. This research study examines the effects of living conditions, gender, and social class on students’ life skills and presents the findings. Future researchers can build upon this, and other factors affecting the research can also be explored.

Destiny F. Williams, Shohreh Hemmati

Silver nanowires (AgNWs) have garnered significant attention in nanotechnology due to their unique mechanical and electrical properties and versatile applications. This review explores the synthesis of AgNWs, with a specific focus on the utilization of millifluidic flow reactors (MFRs) as a promising platform for controlled and efficient production. It begins by elucidating the exceptional characteristics and relevance of AgNWs in various technological domains and then delves into the principles and advantages of MFRs by showcasing their pivotal role in enhancing the precision and scalability of nanowire synthesis. Within this review, an overview of the diverse synthetic methods employed for AgNW production using MFRs is provided. Special attention is given to the intricate parameters and factors influencing synthesis and how MFRs offer superior control over these critical variables. Recent advances in this field are highlighted, revealing innovative strategies and promising developments that have emerged. As with any burgeoning field, challenges are expected, so future directions are explored, offering insights into the current limitations and opportunities for further exploration. In conclusion, this review consolidates the state-of-the-art knowledge in AgNW synthesis and emphasizes the critical role of MFRs in shaping the future of nanomaterial production and nanomanufacturing.

Kumar Aditendra Nath Shah Deo, Anu Priya

The 5th Industrial Revolution (5IR) is reshaping the global business landscape by integrating artificial intelligence, robotics, and the Internet of Things with a renewed focus on human-centered innovation. Talent management (TM), traditionally regarded as a human resources function, must re-envision itself within this paradigm. This paper develops a conceptual framework that applies systems thinking and design thinking to talent management in the context of the 5IR, enabling organizations to remain agile, innovative, and resilient. Systems thinking offers a holistic perspective on understanding the interconnections within the talent ecosystem, while design thinking promotes creative, empathetic, and human-centered solutions. Drawing on recent research on coopetition in SMEs, project-based talent development, global talent practices, and digital readiness in the public sector, the framework highlights the importance of upskilling, leadership support, and the responsible adoption of AI. The outcomes suggest that organizations should adopt holistic and adaptive talent management practices to address skills gaps, foster innovation, and maintain a competitive advantage in the rapidly evolving global environment.

Julia K. Hoskins, Patrick M. Pysz, Julie A. Stenken et al.

This study presents a microfluidic chip platform designed using a multiscale 3D printing strategy for fabricating microfluidic chips with integrated, high-resolution, and customizable membrane structures. By combining two-photon polymerization (2PP) for submicron membrane fabrication with liquid crystal display printing for rapid production of larger components, this approach addresses key challenges in membrane integration, including sealing reliability and the use of transparent materials. Compared to fully 2PP-based fabrication, the multiscale method achieved a 56-fold reduction in production time, reducing total fabrication time to approximately 7.2 h per chip and offering a highly efficient solution for integrating complex structures into fluidic chips. The fabricated chips demonstrated excellent mechanical integrity. Burst pressure testing showed that all samples withstood internal pressures averaging 1.27 ± 0.099 MPa, with some reaching up to 1.4 MPa. Flow testing from ~35 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>L/min to ~345 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>L/min confirmed stable operation in 75 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>m square channels, with no leakage and minimal flow resistance up to ~175 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>L/min without deviation from the predicted behavior in the 75 <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi mathvariant="sans-serif">μ</mi></semantics></math></inline-formula>m. Membrane-integrated chips exhibited outlet flow asymmetries greater than 10%, indicating active fluid transfer across the membrane and highlighting flow-dependent permeability. Overall, this multiscale 3D printing approach offers a scalable and versatile solution for microfluidic device manufacturing. The method’s ability to integrate precise membrane structures enable advanced functionalities such as diffusion-driven particle sorting and molecular filtration, supporting a wide range of biomedical, environmental, and industrial lab-on-a-chip applications.

Camilla Willim, Thales Silva, Luís Oliveira Silva et al.

We present a novel mechanism in which plasma electrons and ions optically acquire angular momentum during local pump depletion of an azimuthally polarized laser, despite the laser carrying none. Using theoretical considerations and multi-dimensional particle-in-cell simulations, we find that this process is enabled by a strong frequency downshift at the gradually eroding laser pulse front. We further show that the angular momentum gained by the plasma electrons is compensated by the ions and by the combined electromagnetic fields of the laser and nonlinear plasma wave. By varying key laser parameters such as phase, frequency, and polarization, we demonstrate that the transverse momentum of high-energy electrons can be effectively controlled.

Luca Barbieri, Simone Landi, Lapo Casetti et al.

We present an extended investigation of a recently introduced model of gravitationally confined, collisionless plasma (Barbieri et al. 2024a), which showed that rapid temperature fluctuations at the base of the plasma, occurring on timescales much shorter than the electron crossing time, can drive the system into a non-thermal state characterized by anti-correlated temperature and density profiles, commonly referred to as temperature inversion. To describe this phenomenon, a temporal coarse-graining formalism was developed (Barbieri et al. 2024b). In this work, we generalize that approach to cover regimes where the timescales of temperature fluctuations are comparable to or exceed the electron crossing time. We derive a set of kinetic equations that incorporate an additional term arising from the coarse-graining procedure, which was not present in the earlier formulation. Through numerical simulations, we analyze the plasma dynamics under these broader conditions, showing that the electric field influences the system when fluctuation timescales approach the electron crossing time. However, for timescales much larger than the proton crossing time, the electric field becomes negligible. The observed behaviours are interpreted within the framework of the extended temporal coarse-graining theory, and we identify the regimes and conditions in which temperature inversion persists.

Jorge Ahumada Lazo, Petr Lelikov, Md Sohaib Bin Sarwar et al.

Here, we experimentally investigate the dynamic behavior of single supercooled droplets falling through a volume of DBD plasma. To achieve a supercooled state, droplets of deionized water are freely suspended by means of an acoustic levitator in a low temperature enclosure. The levitator is placed over a DBD plasma reactor. The reactor is comprised of two electrode disks which planar faces are parallel to each other. One of the electrodes is supplied with a high-voltage AC sinusoidal signal (25 kVpp and f = 10 kHz) while the other one is grounded. A quartz disk is affixed to each of the electrodes to create the dielectric barrier. When the voltage is applied, a volume of plasma is generated within the spacing between the two quartz plates. Once the droplet in the levitator achieves a supercooled state, it is released to fall through the region of plasma. The droplet trajectory and shape oscillations during its interactions with the plasma are monitored using high-speed imagery. The finding suggest that the shape oscillations are suppressed in the supercool state when falling through no plasma and high intensity plasma discharges (lower electric field). At low plasma intensity (higher electric field) oscillations exist in the supercooled state, but droplet relaxation in the oblate mode is suppressed. The reported data suggested that room temperature droplets oscillate near their natural frequency at all plasma intensities, whereas supercooled droplets (at low plasma intensity) oscillated at nearly half of their natural frequency.

Shireen Mahala Tagore, Syed Muzammil Tahamul, Shaik Aathif et al.

Often regarded as the fourth state of matter, the term ‘plasma’ is important for sophisticated technologies including space propulsion and industrial cutting. During the course of the project, we created a simple plasma gun prototype to exhibit how plasma may be produced and manipulated via the laws of physics. The design includes two electrodes with an inert gas like argon flowing in between them and is connected to a high-voltage power supply. An electric arc creates ionization in the gas which gives out a stream of plasma while its exit is controlled by magnetic coils which demonstrate an electromagnetic effect on the plasma as charged particles. This setup is based on core principles like electric discharge, Joule heating, Lorentz force, and basic fluid dynamics. While quite simple, our model attempts to demonstrate the core principles of electric discharge, Joule heating, and the Lorentz force. It allows capturing first-hand experience with effects that tend to be relegated to textbooks or labs. Other versions of the system are in use for an array of applications such as plasma cutters, ion thrusters, and even as sterilizers. The target for this project is to lower the barriers for students and educators while encouraging innovation around plasma technology for future projects.

Kosuke Yamamoto, Hisashi Q. Higuchi, Y. Kawano et al.

Microscopic structural changes on Ti surfaces under low-energy (≤30 eV) and perpendicular hydrogen ion (H+, H2+) irradiation were investigated using molecular dynamics simulations and topological data analysis. Under H2+ irradiation, H retention peaked at 5–7 eV, while H+ irradiation decreased monotonically with increasing energy. Detailed analysis for H2+ irradiation revealed that the retention ratio of two hydrogen atoms composing the H2 molecule followed a similar trend. Persistence diagrams showed additional ring structures formed by H incorporation, leaving the original Ti ring framework intact. Most new rings comprised one H atom and two Ti atoms, with H-Ti distances contracting at lower irradiation energies. The centers of these rings shifted to shallower regions of the Ti surface with decreasing irradiation energy. These findings underscore the potential of low-energy hydrogen ion irradiation for controlled H incorporation into Ti surfaces, suggesting the atomic-level control of plasma-assisted surface engineering.

Ilia Yusefi- Dehlaghi

Plasma actuators function as quick, lightweight solutions for aerofoil airflow control through non-moving parts. The majority of Dielectric Barrier Discharge (DBD) actuator research relies on Computational Fluid Dynamics (CFD), but this paper demonstrates an analytical solution through MATLAB-based modelling. The use of a Gaussian plasma body force distribution relies on the voltage, frequency, and shape of the actuator to predict its effects on airflow using thin-aerofoil theory. The model shows that lift coefficient changes based on actuator placement and strength can produce lift increases of up to 15% during stall conditions. The analytical results match experimental data from published research regarding lift improvement and the best actuator placement positions. The research demonstrates that analytical methods provide fast guidance for designing plasma actuators, particularly when used during initial development stages or limited-resource research settings.

N. Abdullayeva

Wound healing in animals is a highly complex and dynamic biological process that involves coordinated cellular, molecular, and tissue-level responses aimed at restoring structural and functional integrity after injury. This study examines the biological regulation of wound healing in animals, with particular emphasis on the sequential phases of hemostasis, inflammation, proliferation, and remodeling. Clinical and experimental observations were conducted on farm animals with traumatic, surgical, purulent, and necrotic wounds to evaluate healing dynamics under different treatment approaches. The application of bioactive collagen-based dressings and platelet-rich plasma (PRP) therapy significantly reduced microbial contamination, enhanced fibroblast activity, promoted angiogenesis, and accelerated epithelialization compared with conventional antiseptic treatments. Histological and microbiological findings confirmed improved tissue organization and faster wound closure in the experimental group. The results highlight the importance of understanding wound healing biology for optimizing therapeutic strategies and demonstrate the potential of innovative bioactive treatments in improving clinical outcomes in veterinary practice.