High-performance Applications Research Articles

Pt Nanoparticles on Multi-Walled Carbon Nanotubes with High CO Tolerance for Methanol Electrooxidation.

Anode catalysts are important for direct methanol fuel cells (DMFCs) of energy conversion. Herein, we report a novel strategy by ethylene glycol-based deep eutectic solvents (EG-DESs) for the fabrication of a multi-walled carbon nanotubes (MWCNTs)-supported Pt nanoparticles catalyst (referred to as Pt/CNTs-EG-DES). The Pt/CNTs-EG-DES catalyst provides an increased electrochemically active surface area (ECSA) and shows remarkably improved electrocatalytic performance towards methanol oxidation reaction compared to Pt/CNTs-W (fabricated in water) and commercial Pt/C catalysts. The improved performance is attributed to the generation of more Pt-O bonds which change the electronic states of the Pt atoms and the special node structure that obtains more active sites for a high CO resistance. This study suggests an effective synthesis strategy for Pt-based electrocatalysts with high performance for DMFC applications.

Formulating Brown Algae Derived Phloroglucinol-Based Epoxy Resin for High Performance Applications

Formulating Brown Algae Derived Phloroglucinol-Based Epoxy Resin for High Performance Applications

Advanced Venturini control for PMSM with modular multilevel matrix converter

This paper provides a comprehensive analysis of control strategies for modular multilevel matrix converters (MMMC) utilizing advanced second-order sliding mode control (ASOSMC) within the context of permanent magnet synchronous motor (PMSM) applications. The research introduces a novel control framework based on the Venturini method, which, when integrated with ASOSMC, achieves a unity input power factor while generating sinusoidal phase current waveforms with markedly reduced harmonic distortion. These advancements not only enhance overall system performance but also significantly improve power quality, addressing critical requirements in contemporary electrical engineering. Additionally, the study conducts a rigorous comparative analysis between classical Proportional Integral (PI) control and ASOSMC, elucidating the substantial limitations of PI control in nonlinear environments where dynamic adaptability is paramount. In contrast, ASOSMC demonstrates superior capability in managing disturbances and nonlinearities, thereby offering enhanced reliability and efficiency for MMMC systems. The findings illustrate that ASOSMC not only addresses the challenges posed by traditional control techniques but also contributes to the development of more robust control methodologies within power electronics. By establishing a clear superiority of ASOSMC over conventional methods, this research paves the way for future innovations in control strategies specifically tailored for high-performance applications that require resilience under varying operational conditions. Ultimately, this work underscores the necessity of integrating advanced control techniques to optimize the operational capabilities of modular multilevel converters, facilitating the creation of sophisticated solutions that meet the evolving demands of electrical systems and power quality enhancement in diverse applications. The implications of these findings are significant, offering foundational insights for both theoretical exploration and practical implementation in the field.

N, S-Codoped 3D Carbon Protected Nanoporous MnS With Record High Sodium Ion Storage Performance for Potential Industry Applications.

With a high theoretical capacity, the MnS anode, however, exhibits a rather complex sodium diffusion kinetics and poor mechanical stability that hinder its application in sodium-ion batteries (SIBs). In this work, a simple, economical, and scalable strategy is developed to inherently coat nanoporous MnS with a 3D N, S co-doped thin carbon layer by using commercially available MnCO3 as precursors. Specifically, the strategy involves a two-step annealing process, which converts the MnCO3 microparticles into nanoporous Mn2O3 and MnS step by step. The 3D N, S codoped carbon layer is in situ formed during the second annealing process by first coating the nanoporous Mn2O3 with a polyaniline layer. Due to the inherent 3D carbon protection and the strong electronic interaction between N, S dopants and MnS, the N, S codoped carbon protected MnS obtained at 900 °C (NS-C@MnS-900) anode displays a high specific capacity of 845mAhg-1 at 0.1Ag-1, which is higher than all reported MnS-based SIB anodes. It also shows an outstanding cyclability and rate performance, maintaining a stable capacity of ≈493mAhg-1 after 1300 cycles at 10Ag-1, which is also the best according to knowledge. These exceptional electrochemical performances and the scalable/simple/low-cost synthesis make the NS-C@MnS-900 attractive for industry application.

Food waste-derived activated carbon for supercapacitors

This research investigates the utilization of activated carbon synthesized from food waste biomass, specifically, peels of orange, apple, cucumber, and onion, as electrode materials for high-performance supercapacitor applications. The peels were first pre-carbonized at 600 °C and then activated at 700 °C with KOH. The research involved developing a supercapacitor using the synthesized activated carbon as the electrode material and 6 M KOH as the electrolyte. The results indicated that electrodes made from orange peel, apple peel, cucumber peel, and onion peel exhibited specific capacitances of 238.5 F/g, 201.2 F/g, 236.9 F/g, and 118.9 F/g, respectively, at a current density of 1 A/g. When the current density was increased to 2 A/g, the elec-trodes maintained up to 90% of their capacitance.

Construction of Co/Mn-ZIF@Ti3C2Tx composite via in-situ substitution on ZIF-67 for quasi-solid-state supercapacitor with high specific capacitance

Metal-organic frameworks (MOFs) with high specific surface areas, porous structures, and the ability to exchange coordinating ligands have demonstrated exceptional electrochemical performance in supercapacitors. Nevertheless, their conductivity requires further enhancement. Ti3C2Tx, with hydroxyl or terminal oxygen groups on its surface and exhibiting metallic conductivity, can provide additional pathways for ion movement, thereby significantly improving ion transport rates. Based on these concepts, we utilized manganese-doped ZIF-67 MOF as a template and incorporated Ti3C2Tx at an optimal ratio to synthesize the Co/Mn-ZIF@Ti3C2Tx composite for supercapacitors. The Co/Mn-ZIF@Ti3C2Tx electrode exhibits a significantly higher specific capacitance of 1003.3 F·g−1 at 0.5 A·g−1 compared to the original Co/Mn-ZIF electrode and retains 69.3 % of its initial capacitance after 1200 charge–discharge cycles. The assembled Co/Mn-ZIF@Ti3C2Tx//activated carbon asymmetric quasi-solid-state supercapacitor achieves an energy density of 20.85 Wh·kg−1 at a power density of 600.48 W·kg−1. These results surpass those of previously reported supercapacitors, underscoring the potential of the Co/Mn-ZIF@Ti3C2Tx composite for high-performance energy storage applications.

Process-structure–property study of 3D-printed continuous fiber reinforced composites

3D-printed fiber-reinforced composites hold many advantages compared to conventional composites in terms of individualization, mass customization, design freedom, and tailoring the composite geometry to load-bearing specifications. Among candidate continuous fibers for reinforcement, basalt fibers (BFs) serve as an eco-friendly alternative with excellent physical and thermal properties. However, the applicability of continuous BFs to be used for 3D-printed polymer composites was rarely addressed in existing literature. Especially, the effects of impregnation density during manufacturing and the influence of local fiber distribution on the fracture behavior of BF-reinforced composites remain unclear. In this study, a solution coating process was employed as a fiber pre-treatment to improve the packing density of BF in a polylactide (PLA) matrix. The effects of the resulting fiber volume fraction (8–31 %) and the local fiber distribution on the tensile fracture mechanisms of 3D printed BF/PLA samples are thoroughly analyzed using three-dimensional X-ray tomography. It was found that at a concentration of 3 wt%, the coating solution uniformly dispersed optimally between the fibers, resulting in improved impregnation densities of the BF in the PLA matrix. Thus, the resulting composite exhibited a tensile strength of 175 MPa and a Young’s modulus of 6.2 GPa, respectively. A standard linear solid (SLS) model is used for property prediction within a composite design framework to be applied to 3D-printed BF/PLA structures. The model is validated with experimental data from tensile tests. The obtained results demonstrate the applicability of eco-friendly BF/PLA composites for 3D printing of industrial high-performance applications with an individualized property profile.

High and very high cycle fatigue behavior of an additive manufactured hot-work tool steel

In the present study, the fatigue response of an additive manufactured H13 type hot-work tool steel is investigated across the High Cycle Fatigue (HCF) and Very High Cycle (VHCF) regimes. The primary focus encompasses the interpretation of fatigue strength models, the defect type analysis along with a detailed examination of crack initiation and growth mechanisms. Despite the tremendous development in AM technology, experimental data regarding advanced mechanical properties, and particularly fatigue behavior, are still limited. Here, microstructural analysis of a modified AMed H13 hot-work tool steel, a combination of HCF and VHCF testing methodologies implemented for the characterization of the fatigue behavior, as well as a thorough fractographic analysis of the fractured surfaces were performed. Results are compared with historical data of a conventionally ingot cast and forged grade to assess the influence of the AM process on the fatigue response of H13 hot-work tool steels. It proves to be comparable to the conventionally manufactured grade, showcasing the potential utilization of AM in the production of components used in high-demanding applications, and in hot work tooling applications. However, the type of critical defects identified in the AM grade was found to be process-induced, emphasizing the need to optimize process parameters to reduce both the number and size of defects and also to ensure component reliability and high performance in various industrial applications.

Bio-Templated Aerogel Fibers: Heterogeneous Spinodal Architecting and In Situ Fibrillation of Thermoplastic Polyurethane-Silica on Nanostructured Cellulose Nanofiber Scaffold for Enhanced Thermomechanical Performance.

This study addresses the inherent fragility and fractal limitations of traditional silica aerogels by developing a bio-templated aerogel fiber. Integrating cellulose nanofibers (CNFs), thermoplastic polyurethane (TPU), and silica aerogel (SA) in a dimethyl sulfoxide (DMSO) dispersion, a gel-spinning technique was employed to create aerogel fibers with superior thermomechanical performance. CNF also provided excellent rheological modification for successful spinnability, fast gelation, and fiber formation. The unique hierarchical structure of these fibers, formed through hot-stretching and surface modification, combined the superior mechanical strength and flexibility of TPU with the exceptional insulation properties of CNF and SA. The CNF network, encapsulated within the SA particles, formed a core-shell structure, axially aligned, that significantly enhances the thermal stability and mechanical performance of the fibers while maintaining a lightweight and porous architecture. Comprehensive morphological, thermal, and mechanical analyses were conducted to evaluate the properties of the developed aerogel fibers. Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR) spectroscopy verified the successful surface modification and grafting reactions on CNF, contributing to improved hydrophobicity and thermal insulation. Adjusting the CNF content allowed for tailoring of the thermomechanical characteristics, with a notable 294% increase in tensile strength from 5.3 to 15.6 MPa and an enhanced crystallization temperature from 106 to 119.97 °C. Furthermore, cyclic tensile and compression tests validated the durability and shape recovery capabilities of the aerogel fibers, making them promising candidates for high-performance applications in extreme environments. The thermal conductivity validated by experimental data further highlights the potential of CNF-based aerogel fibers as sustainable and multifunctional materials for advanced thermal insulation, mechanical reinforcement, and flexible structural applications.

Innovative D-process MIG welding for enhanced performance of thick sections of MDN 250 in aerospace applications

Maraging steel, known for its exceptional strength, toughness and ductility, is widely used in aerospace and hypersonic missile manufacturing. The present study investigates the feasibility of joining 12 mm thick sections of maraging steel using advanced D-Process MIG welding technology. The D-Process integrates different welding modes such as MIG, Single Pulse-MIG and Double Pulse-MIG to optimize welding parameters, minimizing heat input. Additionally, the research investigates the influence of various post-weld heat treatments (PWHTs) on the performance of welded joints. The PWHTs included in the study are Ageing Treatment (AT), Solution Treatment + Ageing Treatment (SAT) and Homogenizing Treatment + Solution Treatment + Ageing Treatment (HSAT). Metallographic and mechanical tests were conducted on as-welded (AW) and PWHT conditions. Results showed the HSAT condition yielded superior properties with an average UTS of 1771 MPa, YS of 1734 MPa, and an average fracture toughness (FT) of 88 MPa√m. This underscores the efficacy of D-Process welding in meeting stringent requirements for maraging steel in aerospace and high-performance applications.

Efficient MIMO Antenna Design Using Metamaterials for Compact and High-Performance Communication Applications

Efficient MIMO Antenna Design Using Metamaterials for Compact and High-Performance Communication Applications

Fabrication of Green Composite Materials Using the Weight Sum Method (WSM) Method

The quest for sustainable materials the investigation into natural fibers for composite materials has been prompted by this development., aiming to reduce the environmental impact of traditional synthetic composites. In this study, we investigate the potential of flax, hemp, jute, kenaf, and ramie fibers as reinforcements in green composites fabricated using the Water Soaking Method (WSM). The evaluation parameters considered include density (g/cm3), fiber diameter (μm), tensile strength (MPa), Young’s modulus (GPa), and elongation at break (%). Through meticulous experimentation and analysis, it is revealed that jute emerges as the frontrunner among the alternatives, exhibiting superior performance across multiple evaluation parameters. Jute-based green composites demonstrate commendable strength and stiffness properties, coupled with a moderate density, making them promising candidates for various structural applications. Conversely, kenaf fiber-based composites exhibit the lowest performance in terms of evaluated parameters, indicating potential limitations in its suitability for high-performance applications. The comparative assessment underscores the significance of material selection in composite fabrication, emphasizing the diverse mechanical properties exhibited by different natural fibers. Furthermore, the utilization of the WSM method showcases its effectiveness in producing green composites with desirable characteristics, signifying its potential as a viable manufacturing technique for sustainable materials. eco-friendly composites, highlighting the importance of considering multiple factors such as fiber type and fabrication method in achieving optimal performance and environmental sustainability in composite materials. Further research may delve into refining fabrication techniques and exploring novel fiber combinations applications.

Review of Wear and Mechanical Characteristics of Al-Si Alloy Matrix Composites Reinforced with Natural Minerals

Al-Si alloys are vital in the aerospace and automotive industries due to their high strength-to-weight ratio, excellent ductility, and superior corrosion resistance. These properties, along with good thermal conductivity, low thermal expansion, and enhanced wear resistance due to silicon, make them ideal for lightweight, high-performance components like engine parts exposed to harsh conditions and thermal cycling. In recent years, the development of aluminium metal matrix composites using Al-Si alloys as the base material has gathered significant attention. These composites are engineered by integrating various reinforcing particles into the aluminium matrix, which results in remarkable improvements in the wear resistance, hardness, and overall mechanical performance of the material. The stir casting process, a well-established and cost-effective method, is frequently employed to ensure a uniform distribution of these reinforcing particles within the matrix. This review delves into the influence of different types of reinforcing particles on the properties of Al-Si alloy-based AMCs. The incorporation of these reinforcements has been shown to significantly enhance wear resistance, reduce friction, and improve the overall strength and toughness of the composites, making them ideal candidates for high-performance applications in the automotive and aerospace sectors. Moreover, this review highlights the challenges associated with the fabrication of these composites, such as achieving a homogeneous particle distribution and minimizing porosity. It also discusses the latest advancements in processing techniques aimed at overcoming these challenges. Additionally, this review addresses the potential environmental and economic benefits of using natural reinforcements, which not only reduce material costs but also contribute to sustainable manufacturing practices.

Insight into the Coordination Environment of Ru Single-Atom for Dry Reforming of Methane.

Dry reforming of methane (DRM), a pivotal process for converting greenhouse gases into syngas is demanding rationally designed catalysts with high stability and ideal catalytic performance for industrial applications due to its stability of reactant molecules and characteristic of carbon deposition. However, the mechanistic understanding of how the coordination environment of the metal in a single-atom catalytic system may influence the catalytic performance remains limited. In this work, high- and low-coordinating Ru-based (RuHC and RuLC) catalysts with distinct Ru-O coordination numbers are prepared using one-pot and two-step methods. The difference in the stability (12.3% and negligible deactivation during 20 h test for RuLC and RuHC catalysts respectively) and selectivity (0.57 and 0.37 of H2/CO ratio) brought by the coordination environment signified the structure-function relationship of single-atom catalysts in DRM. The impact of the structure on the properties is systematically investigated by thorough structural and operando characterization as well as density functional theory (DFT) calculation. The findings contribute to the optimal design of single-atom catalysts for DRM, offering a theoretical basis for industrial catalyst development and the potential to improve the process's environmental impact.

Comparative analysis of thermoelectric properties in bulk 2H and monolayer MoS2: a first-principles study at high temperatures

The pursuit of high-efficiency heat-to-electricity conversion is one of the indispensable driving forces toward future renewable energy production. The two-dimensional (2D) transition metal dichalcogenide, such as molybdenum disulfide (MoS2), is at the forefront of research due to its outstanding heat propagation features and potential applications as a thermoelectric material. Using the first-principles density functional theory coupled with the semi-classical Boltzmann transport equation within the constant relaxation time approximation, we present the thermoelectric and energy transport in the bulk 2H and monolayer MoS2 material system. In order to advance the underlying physics, we calculate several crucial transport parameters such as electrical conductivity, electronic thermal conductivity, Seebeck coefficient, and power factor as a function of the reduced chemical potential for different doping types and temperatures, in addition to the electron energy dispersion relation of the material system. Our comprehensive study employs the Shankland interpolation algorithm and the rigid band approximation to attain a high degree of accuracy. This thorough investigation reveals the high Seebeck coefficient of 1534 and 1550 μ V/K at 500 K for the bulk 2H and monolayer MoS2, respectively. Furthermore, the ultrahigh power factor values of 9.21 × 1011 and 3.69 × 1011 Wm −1 K −2 s −1 are shown at 800 K in the bulk 2H and monolayer MoS2, respectively. Based on the power factor results, our in-depth analysis demonstrates that the bulk 2H MoS2, when compared to monolayer MoS2, exhibits great potential as a promising semiconducting thermoelectric material for advanced high-performance energy device applications.

Enhancing Optoelectronic Performance of All-Inorganic Double Perovskites via Halogen Doping: Synergistic Screening Strategies and Multiscale Simulations.

Designing all-inorganic double perovskites through element mixing is a promising strategy to enhance their optoelectronic performance and structural stability. The complex interplay between multilevel structures and optoelectronic properties in element-mixed double perovskites necessitates further in-depth theoretical exploration. In this study, we employ screening strategies and multiscale simulations combining first-principles methods and device-scale continuum models to identify two novel element-mixed compounds, Rb2AgInCl3I3 and Cs2AgInCl3I3, as promising candidates for photovoltaic applications. These compounds exhibit favorable structural factors and suitable direct band gaps. Theoretical investigations using first-principles methods with the HSE06 functional reveal direct band gaps of 0.98 and 1.26 eV for Rb2AgInCl3I3 and Cs2AgInCl3I3, respectively, with corresponding optical absorption coefficients exceeding 105 cm-1 in the visible light range. Cs2AgInCl3I3 features high charge mobilities of approximately 20 cm2·V-1·s-1 and a notable single-junction spectroscopic limited maximum efficiency (SLME) of 25.54%. Further analysis using the device-scale continuum model simulated the nonradiative recombination effects on power conversion efficiency, integrating quantum-mechanically calculated optoelectronic properties. These theoretical investigations, which bridge composition engineering with multiscale simulations, provide valuable insights into screening novel, lead-free, halogen-mixed double metal perovskite optoelectronic devices, highlighting their potential for high-performance solar energy applications.

KCaAs and KCaP: promising half-Heusler compounds for UV protection and thermoelectric applications

This study investigates the structural, electrical, optical, and thermoelectric properties of the half-Heusler compounds KCaAs and KCaP using the Full-Potential Linearized Augmented Plane Wave (FP-LAPW) method within the framework of density functional theory. Our analysis reveals that both compounds exhibit favourable characteristics for high-performance applications. Specifically, KCaAs and KCaP show high static refractive indices and significant reflectivity in the ultraviolet (UV) range, making them ideal for UV protection and optical devices. Thermoelectric analysis indicates that both materials are p-type semiconductors with high Seebeck coefficients at low temperatures, high electrical conductivity, and relatively low thermal conductivity. The temperature-dependent figure of merit ( ZT ) reveals robust thermoelectric performance across a wide temperature range, with maximum ZT values of approximately 0.77 for both compounds. These results suggest that KCaAs and KCaP are promising candidates for thermoelectric applications, offering significant potential for energy conversion and sustainable energy solutions.

Enhanced UV photodetector using Mg-doped ZnO sub-micro tube films synthesized through laser-assisted chemical bath growth

This study presents the fabrication of MgxZn(100-X)O thin films (TFs) with Mg concentration levels (x) of 0.5 at%, 1.0 at%, 1.5 at%, and 2.0 at% on glass substrates using the novel laser-assisted chemical bath growth (LACBG) method, aimed at investigating their photo-response for potential UV photodetector applications. Utilizing a continuous wave semiconductor laser with a 444.5 nm wavelength, 1 W power, and 6 min of irradiation, the LACBG method successfully produced high-quality Mg-doped ZnO TFs. These films were deposited on glass substrates coated with silver (Ag) to serve as electrode contacts for constructing a metal-semiconductor-metal (MSM) UV photodetector. The structural, optical, and electrical properties of the TFs were thoroughly analyzed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) were employed to examine the crystal microstructures and surface morphologies, revealing vertically aligned hexagonal symmetrical sub-micro tubes. In contrast, energy dispersive X-ray (EDX) analysis confirmed successful Mg incorporation into the ZnO lattice. UV–visible absorbance spectra indicated a blue shift in the absorption edge and increased band gap energy from 3.24 eV to 3.67 eV with rising Mg content. The UV photodetectors, particularly those with 2.0 at% Mg-doped ZnO TFs, demonstrated significantly enhanced UV responsiveness attributed to optical confinement, high surface-to-volume ratio, and superior structural quality. Performance metrics for the 2.0 at% Mg-doped ZnO TFs included a responsivity of 10.60 A/W, external quantum efficiency of 34.10, specific detectivity of 2.25 × 107 Jones, noise equivalent power of 5.34 × 10−11 W, rise time of 86.9 ms, and decay time of 324.4 ms. These findings underscore the potential of Mg-doped ZnO TFs for high-performance UV photodetection applications. The novelty of this study lies in utilizing LACBG to achieve high-quality Mg-doped ZnO TFs, offering a cost-effective, low-temperature method that enhances UV photodetector performance.

Reverse characterization prediction of diamond Schottky barrier power devices using machine learning: Predicting breakdown voltage and Baliga figure of merit

Diamond power devices showed great potential for high-performance and low-loss applications at high frequencies. Schottky power diodes on the diamond have markedly higher threshold reverse operation limits than other power devices, yet they are still far from the ideal limit. Therefore, utilizing the device capabilities across optimizing device parameters is severely time- and resource-intensive considering traditional trial-and-error experimental methodology. On the other hand, data-driven techniques can accelerate device optimization and reduce resource consumption. This work demonstrates machine learning models that predict breakdown voltage in addition to Baliga's power figure of merit (BFOM) for the first time. An experimentally driven dataset is constructed because of its reliability, precision, and potential for generalization. This dataset contains current-voltage characteristics raw data for more than 400 devices fabricated on heteroepitaxial diamond. Four machine learning algorithms are explored and evaluated based on 5-fold cross-validation to prevent overfitting. The extra-tree model shows the highest performance that accurately predicts the breakdown voltage, and the BFOM with R2 equal to 0.924 and 0.911, respectively. Additionally, it showed robust prediction accuracy on unseen data with an 8 % average relative error of 16 devices. Achieving this high accuracy indicates the potential of these models for generalization on various datasets.

Capacity augmentation strategy in α-Fe2O3 nanoparticles through multifaceted structural and electrochemical analyses

Hematite (α-Fe₂O₃) has garnered significant research interest for supercapacitor applications, but capacity fading and limited cyclic life remain serious challenges. In this context, the present research provides a comprehensive study of the factors that significantly impact charge kinetics within the electrode and at the solid/electrolyte interface. By integrating structural and electrochemical analyses, this study offers an effective strategy to enhance the capacity of α-Fe₂O₃ nanoparticles through rigorous scientific analysis and identification of various qualitative and quantitative factors that influence charge storage capacity. A simple one-step co-precipitation method was adopted to synthesize porous α-Fe₂O₃ nanoparticles. The quantitative analysis of charge kinetics demonstrated the domination of diffusion-controlled charge storage as the main contributor to the total charge storage. The α-Fe₂O₃ nanoparticles-based electrode delivered a high energy density of 24.6 Wh kg⁻1 at an impressive power density of 478.7 W kg⁻1. Additionally, it displayed a capacity retention of 79 % over 10,000 cycle operations. The choice of electrode material and the superior porous nanoarchitecture have proven to be advantageous for high-performance supercapacitor applications, offering fast electron/ion transport.