Search Results (227)

The anti-pillow effect of mesh antennas has adverse effects on satellite communication. The curvature isotropy of a negative Poisson’s ratio material is expected to be applied and solved for the anti-pillow effect of mesh deployable antennas. Based on the tension characteristics of mesh antennas, our research group has proposed a novel pre-wound six-ligament chiral material, and provided the analytical solutions of Poisson’s ratio and Young’s modulus under the assumption of a small deformation. Following on from the above work, this paper takes into account the variable curvature deformation of pre-wound ligaments and the bending deformation of straight ligaments. The analytical solutions of Poisson’s ratio and Young’s modulus under large deformations are derived, and verified by finite element simulation combined for both small and large deformations. The results show that theoretical solutions considering large deformation of the ligament are more consistent with the simulation results in the large-strain range of anisotropy in the material plane. The analytical solution of Young’s modulus derived from the energy equivalent principle of elastic deformation with a curved beam and a straight beam is consistent with the simulation results under large tensile strain. It has been verified that the existence of a pre-wound ligament can slow down the deformation of the node and reduce the loss of in-plane isotropy to a certain extent, so it is easier to maintain the negative Poisson’s ratio characteristic and maintain an excellent in-plane isotropic deformation mechanism over a larger strain range under tensile load. This characteristic proves the reliability of the prospects applying the pre-wound six-ligament chiral structure in deployable mesh antennas, which lays a theoretical foundation for the subsequent prototype. Full article

The assessment of the dynamic mechanical performance of fiber-reinforced composites has gained importance in specific high-tech applications like aerospace and automobiles. However, three dimensional (3D) auxetic reinforcements offering viable performance have remained unexplored. Hence, this study investigates the energy absorption capabilities and high strain impact behaviors of 3D woven fabric-reinforced composites. Three different types of 3D woven reinforcements i.e., warp interlock (Wp), weft interlock (Wt), and bidirectional interlock (Bi) were developed from jute yarn, and their corresponding composites were fabricated using polycarbonate (PC) and polyvinyl butyral (PVB). Out-of-plane auxeticity was measured for reinforcements while composites were analyzed under dynamic tests. Wp exhibited the highest auxeticity with a value of −1.29, Bi showed the least auxeticity with a value of −0.31, while Wt entailed an intermediate value of −0.46 owing to variable interlacement patterns. The dynamic mechanical analysis (DMA) results revealed that composite samples developed with PC resin showed a higher storage modulus with the least tan delta values less than 0.2, while PVB-based samples exhibited higher loss modulus with tan delta values of 0.6. Split Hopkinson pressure bar (SHPB) results showed that, under 2 and 4 bar pressure tests, PVB-based composites exhibited the highest maximum load while PC-based composites exhibited the least. Warp interlock-based composites with higher auxeticity showed better energy absorption when compared with the bidirectional interlock reinforcement based (with lower auxeticity) composites that exhibited lower peak load and energy dissipation. Full article

The rapid development of high-end equipment has created stringent requirements for multifunctional integration in materials. However, traditional porous materials have faced a fundamental trade-off between lightweight characteristics and mechanical and acoustic performance. To address this challenge, a design and fabrication method for interpenetrating phase composites (IPCs) based on triply periodic minimal surface (TPMS) structures was proposed. The effects of porosity, unit cell size, and structural type on the performance of porous structures were systematically investigated. TPMS frameworks were fabricated from AlSi7Mg alloy using laser powder bed fusion (LPBF). These frameworks were then combined with thermoplastic polyurethane (TPU) via a foaming infiltration process to create the AlSi7Mg/TPU IPCs. Acoustic and compression tests were performed using an impedance tube and a universal testing machine. The results indicated that, compared to unfilled TPMS structures, the IPCs exhibited a shift in the first peak acoustic absorption coefficient to lower frequencies, an increase (1.59 = fold) in the average acoustic absorption coefficient within the 500–6300 Hz range, and a significant enhancement (35.58 fold) in the average normal incidence transmission loss (TL). Under quasi-static compression, the plateau stage was sustained over 60% strain, and the energy absorption capacity increased by a factor of 3.56. This research provides a technical reference for developing multifunctional materials for aerospace and other acoustic applications. Full article

The influence of M site substitution in MCr₂O₄ nanoceramics on their properties is examined in this research. This study is an attempt to correlate the structural, morphological, and optical properties of M-site-modified chromites. The MCr₂O₄ nanoceramics-CuCr₂O₄, CoCr₂O₄, and NiCr₂O₄ were synthesized using a wet chemical sol–gel auto-combustion method, and all three samples were annealed for 4 h at 900 °C. X-ray diffraction analysis showed that the XRD patterns of CuCr₂O₄, CoCr₂O₄, and NiCr₂O₄ correspond to single-phase cubic crystal structures with the space group Fd-3m. Using the Scherrer equation, the crystallite sizes were found to be 9.86 nm, 6.73 nm, and 10.73 nm for CuCr₂O₄, CoCr₂O₄, and NiCr₂O₄, respectively. Other parameters, including crystal structure, micro-strain, lattice constant, unit cell volume, X-ray density, packing factor, and the stacking fault of the calcined powder samples, were determined from data acquired from the X-ray diffractometer. Energy dispersive X-ray spectroscopy (EDX) was employed to confirm the appropriate chromite elements in their expected stoichiometric proportions, removed from other impurities. The identification of the functional groups of the samples was performed using Fourier Transform Infrared Spectroscopy (FTIR). The absorption bands characteristic of tetrahedral and octahedral coordination compounds of the spinel structure are found between 450 and 750 cm⁻¹ for all three samples in the spectrum. From the UV-absorption spectra, and using Tauc’s plot, the energy bandgap values for CuCr₂O₄, CoCr₂O₄, and NiCr₂O₄ were measured to be 1.66 eV, 1.82 eV, and 2.01 eV, respectively. The dielectric properties of the chromites were studied using an LCR meter. Frequency-dependent dielectric properties, including Dielectric constant and Tangent loss, were calculated. These findings suggest the feasibility of the use of these synthesized chromites for optical devices and other optoelectronic applications. Full article

Ultrasonic phased arrays have shown promise in generating virtual texture haptics through haptics feedback points. However, factors such as skin vibration speed, amplitude variations, acoustic interference, and energy loss can influence textural haptics. In this study, using Spatiotemporal Modulation (STM), virtual textures are produced through movement of the focal point. The acoustic field of the ultrasonic phased array as well as the stress and strain experienced by the skin during texture perception are simulated by numerical analysis. At the same time, psychophysical experiments are conducted by volunteers to evaluate these textures. The experimental results indicate that as the focal rotation frequency increases, regions closer to the center experience more significant shear wave effects, resulting in longer shear wave propagation, reduced tangential stress amplitude, and a larger affected area. Moreover, as the frequency of the shear wave interference shifts, it results in increasingly complex textural representations. Full article

Active distribution systems (ADS) are increasingly strained by rising energy demand and the widespread deployment of distributed energy resources (DERs) and electric vehicle charging stations (EVCS), which intensify voltage deviations, power losses, and peak demand fluctuations. This study develops a coordinated optimization framework for Mobile Battery Energy Storage Systems (MBESS) and Dynamic Feeder Reconfiguration (DFR) to enhance network performance across technical, economic, and environmental dimensions. A Non-dominated Sorting Genetic Algorithm III (NSGA-III) is employed to minimize six objectives the active and reactive power losses, voltage deviation index (VDI), voltage stability index (FVSI), operating cost, and CO₂ emissions while explicitly modeling the MBESS transportation constraints such as energy consumption and single-trip mobility within coupled IEEE 33-bus and 33-node transport networks, which provide realistic mobility modeling of energy storage operations. The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is applied to select compromise solutions from Pareto fronts. Simulation results across six scenarios show that the coordinated MBESS–DFR operation reduces power losses by 27.8–30.1%, improves the VDI by 40.5–43.2%, and enhances the FVSI by 2.3–2.4%, maintaining all bus voltages within 0.95–1.05 p.u. with minimal cost (0.26–0.27%) and emission variations (0.31–0.71%). The MBESS alone provided limited benefits (5–12%), confirming that coordination is essential for improving efficiency, voltage regulation, and overall system sustainability in renewable-rich distribution networks. Full article

The Lake Velence watershed faces increasing challenges driven by local and global factors, including the impacts of climate change, energy resource limitations, and greenhouse gas emissions. These issues, particularly acute in water management, are exacerbated by prolonged droughts, growing population pressures, and shifting land use patterns. Such dynamics strain the region’s scarce water resources, negatively affecting the environment, tourism, recreation, agriculture, and economic prospects. Nadap, a hilly settlement within the watershed, experiences frequent flooding and poor water retention, yet it also boasts the highest solar panel capacity per property in Hungary. This research addresses these interconnected challenges by designing a solar-hydrodynamic network comprising four multi-purpose water reservoirs. By leveraging the settlement’s solar capacity and geographical features, the reservoirs provide numerous benefits to local stakeholders and extend their impact far beyond their borders. These include stormwater management with flash flood mitigation, seasonal green energy storage, water security for agriculture and irrigation, wildlife conservation, recreational opportunities, carbon-smart winery developments, and the creation of sustainable blue-green settlements. Reservoir locations and dimensions were determined by analyzing geographical characteristics, stormwater volume, energy demand, solar panel performance, and rainfall data. The hydrodynamic system, modeled in Matlab, was optimized to ensure efficient water usage for irrigation, animal hydration, and other needs while minimizing evaporation losses and carbon emissions. This research presents a design framework for low-carbon and cost-effective solutions that address water management and energy storage, promoting environmental, social, and economic sustainability. The multi-purpose use of retained rainwater solves various existing problems/challenges, strengthens a community’s self-sustainability, and fosters regional growth. This integrated approach can serve as a model for other municipalities and for developing cost-effective inter-settlement and cross-catchment solutions, with a short payback period, facing similar challenges. Full article

Traditional single-layer water-lubricated rubber or plastic bearings suffer from water film rupture, excessive frictional losses, and insufficient load-carrying capacity, which limit performance and service life in marine propulsion and ocean engineering. To address these issues, this study introduces an innovative laminated bearing consisting of a rubber composite layer and an ultra-high-molecular-weight polyethylene (UHMWPE) layer. A three-dimensional dynamic model based on fluid–structure interaction theory is developed to evaluate the effects of eccentricity, rotational speed, and liner thickness on lubrication pressure, load capacity, deformation, stress–strain behavior, and frictional power consumption. The model also reveals how thickness matching governs load transfer and energy dissipation. Results indicate that eccentricity, speed, and thickness are key determinants of lubrication and structural response. Hydrodynamic pressure and load capacity rise with eccentricity above 0.8 or higher speeds, but frictional losses also intensify. The rubber layer performs optimally at a thickness of 5 mm, while excessive or insufficient thickness leads to stress concentration or reduced buffering. The UHMWPE layer exhibits optimal performance at 5–7 mm, with greater deviations resulting in increased stress and deformation. Proper thickness matching improves pressure distribution, reduces local stresses, and enhances energy dissipation, thereby strengthening bearing stability and durability. Full article

The paradigm shift from FinFET to gate-all-around nanosheet (GAA-NS) transistor architectures necessitates fundamental innovations in channel material engineering. This work addresses the critical challenge of pFET performance degradation in GAA-NS technologies through the development of an advanced selective etching process for strain-engineered SiGe channel formation. We present a systematic investigation of Si selective etching using CF₄/O₂/N₂ gas mixture in a remote plasma source reactor. It is demonstrated that the addition of N₂ to CF₄/O₂ plasmas significantly improves the selectivity of Si to SiGe (up to 58), by promoting NO* radical-induced passivation layer disruption on Si surfaces. Furthermore, an increase in the F:O ratio has been shown to mitigate stress-induced lateral micro-trenching (“Si-tip”), achieving near-zero tip length at high CF₄ flow (500 sccm) while retaining selectivity (>40). Transmission electron microscopy and energy-dispersive X-ray spectroscopy confirm the complete removal of the Si sacrificial layer with minimal SiGe channel loss, validating the process for high-performance SiGe GAA-NS FET integration. These findings provide critical insights into strain-engineered SiGe channel fabrication, enabling balanced NFET/PFET performance in next-generation semiconductor technologies. Full article

Ensiling forage under low-temperature conditions often leads to poor fermentation and nutrient losses. This study evaluated the effects of a cold-tolerant Pediococcus pentosaceus OL77 strain on oat silage. Silages were prepared with or without Pediococcus pentosaceus inoculation (1 × 10⁵ cfu/g FM). After 90 days, OL77-treated silage showed markedly higher lactic acid (45.83 vs. 30.51 g/kg DM), lower pH (3.88 vs. 4.443), and better preservation of WSC (64.68 vs. 47.60 g/kg DM) and crude protein (89.26 vs. 65.52 g/kg DM) than the control. Microbial analysis revealed accelerated colonization by Pediococcus, reduced bacterial diversity, and faster stabilization of the fermentation process. Functional predictions indicated enhanced carbohydrate and energy metabolism. These findings demonstrate that OL77 can effectively improve fermentation quality and nutrient preservation of oat silage under low-temperature conditions, offering a practical inoculant option for cold regions. Full article

To address the challenge of balancing the damping performance with mechanical strength in conventional polyurea materials for blast mitigation, this study develops a constrained layer damping coating structure using Q413t viscoelastic polyurea (Q413t) as the damping layer and FPU-1 flexible polyurea (FPU-1) as the constraining layer. The mechanical behaviors of both types of polyurea were characterized through tensile testing at varying loading speeds, while dynamic thermomechanical analysis was utilized to evaluate their damping properties. A 75 g TNT contact explosion test and finite element simulation were employed to explore the protective mechanism. The results show that Q413t demonstrates significant strain-rate sensitivity under intermediate-strain-rate conditions, whereas FPU-1 exhibits minimal variation in mechanical strength. Q413t demonstrates a superior damping performance over a frequency range of 0–10⁴ Hz. FPU-1 achieved a loss factor of 0.3 when the loading frequency reached 10⁴–10⁵ Hz. Under the 75 g TNT contact explosion load, the configuration with a 1 mm damping layer and a 3 mm constraint layer achieved a maximum displacement reduction of 35.26%. In the constrained layer damping coating, the damping layer contributes to blast protection through energy dissipation and load distribution, while the constraining layer reduces structural deformation by limiting displacement. Relative motion between the layers further enhances the overall damping performance. The constrained layer damping coating provides optimal blast protection when the damping-to-constraining layer thickness ratio is 1:3. The constrained layer damping coating enables the synergistic optimization of mechanical strength and energy dissipation, effectively mitigating structural deformation induced by blast loading and demonstrating promising engineering application potential. Full article

Neurodegenerative diseases, including Alzheimer’s disease (AD), Parkinson’s disease (PD), and amyotrophic lateral sclerosis (ALS), represent significant global health challenges, affecting millions and straining healthcare systems. These disorders involve progressive neuronal loss and cognitive decline, with incompletely elucidated underlying mechanisms. Chronic neuroinflammation is increasingly recognized as a critical contributor to disease progression. The brain’s resident immune cells, microglia, are central to this inflammatory response. When overactivated, microglia and other immune cells, such as peripheral macrophages, can exacerbate inflammation and accelerate disease development. Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) is a transmembrane receptor of the immunoglobulin superfamily that demonstrates high expression on microglia in the central nervous system. TREM2 serves a vital role in regulating phagocytosis, synaptic pruning, and energy metabolism. This review examines the functions of TREM2 in neurodegenerative diseases and its potential as a therapeutic target, aiming to inform future treatment strategies. Full article

This article examines the potential role of the Antonine Plague (165–180 CE) and climate change in the mid-2nd-century collapse of the Afro-Eurasian world-system. Following the model proposed by Gills and Frank, the world-system cycles between phases of integration (A) and disintegration (B). Integrative phases are marked by increasingly complex exchanges of goods, services, information, and populations, which enhance connectivity and intensify the circulation of matter and energy. Yet, this very complexity, while driving growth and expansion, also generates systemic vulnerabilities. The plague and climate change are examined here as critical shocks that triggered the shift from an A phase to a B phase, destabilizing interconnected regions such as the Roman Empire in the West and the Han Dynasty in China. The demographic losses and logistical strains of the pandemic eroded the integrative structures underpinning Afro-Eurasian connectivity, creating conditions for prolonged disintegration. These developments are further situated within the broader history of the Silk Roads, whose role in fostering transcontinental connections had reached a peak in the centuries preceding the crisis. The analysis underscores how pandemics like the Antonine Plague, together with episodes of abrupt climate change, can act as decisive agents in the disintegration phases of world-systems, reshaping the trajectories of complex societies and accelerating the collapse of established networks. Full article

In the simulation of 3C-SiC strain gauges in dynamic environment—particularly those involving vibrations and wave propagation—the accurate representation of energy dissipation is essential for reliable predictive modeling. This paper discusses the implementation of both isotropic and anisotropic damping models within COMSOL Multiphysics. In particular, it focuses on the use of an anisotropic loss factor, represented either as a scalar (η_S) for isotropic cases or as a symmetric 6 × 6 loss factor matrix (${\mathsf{\eta }}_{\mathrm{D}}$) for anisotropic dissipation. This formulation enables the directional dependence of damping behavior to be captured, which is particularly important in composite materials, layered media, and metamaterials where energy dissipation mechanisms vary with orientation. The paper also explores the numerical implications of using anisotropic damping, such as its influence on eigenfrequency solutions, frequency response functions, and transient dynamic simulations. Furthermore, it highlights how the inclusion of directional damping can improve the correlation between simulated and experimental results in scenarios where standard isotropic models fail to capture key physical behaviors. Full article

The genus Microbulbifer comprises a group of marine, gram-negative bacteria known for their remarkable ability to adapt to a variety of environments. Therefore, this study aimed to investigate the genetic diversity and metabolic characteristics of M. spongiae MI-G^T and three Microbulbifer reference strains by genomic and comparative genomic analysis. Compared to free-living reference strains, the lower GC content, higher number of strain-specific genes, pseudogenes, unique paralogs, dispensable genes, and mobile gene elements (MGEs) such as genomic islands (GIs) and insertion sequence (IS) elements, while the least number of CAZymes, indicates that M. spongiae MI-G^T may be a facultative sponge-symbiont. Comparative genomic analysis indicates that M. spongiae MI-G^T possesses a plasmid and a higher number of strain-specific genes than Microbulbifer reference strains, showing that M. spongiae MI-G^T may have acquired unique genes to adapt sponge-host environment. Moreover, there are differences in the functional distribution of genes belonging to different COG-classes in four Microbulbifer strains. COG-functional analysis reveals a lower number of strain-specific genes associated with metabolism, energy production, and motility in M. spongiae MI-G^T compared to Microbulbifer reference strains, suggesting that sponge-associated lifestyle may force this bacterium to acquire nutrients from the sponge host and loss motility genes. Finally, we found that several proteins associated with oxidative stress response (sodC, katA, catA, bcp, trmH, cspA), osmotic stress response (dsbG, ampG, amiD_2, czcA, czcB, and corA), and tolerance to biotoxic metal proteins (dsbG, ampG, amiD_2, czcA, czcB, and corA) are absent in M. spongiae MI-G^T but present in Microbulbifer reference strains, indicating that M. spongiae MI-G^T live in a stable and less stress environment provided by the sponge host than free-living Microbulbifer strains. Our results suggest M. spongiae MI-G^T exhibits gene characteristics related to its adaptation to the sponge host habitat, meanwhile reflecting its evolution towards a sponge-associated lifestyle. Full article