Search Results (5,099)

Ternary hybrid nanofluid have been revealed to possess a wide range of application disciplines reaching from biomedical engineering, detection of cancer, over or photovoltaic panels and cells, nuclear power plant engineering, to the automobile industry, smart cells and and eventually to heat exchange systems. Inspired by the recent developments in nanotechnology and in particular the high potential ability of use of such nanofluids in practical problems, this paper deals with the flow of a three phase nanofluid of MWCNT-Au/Ag nanoparticles dispersed in blood in the presence of a bidirectional stretching sheet. The model derived in this study yields a set of linked nonlinear PDEs, which are first transformed into dimensionless ODEs. From these ODEs we get a dataset with the help of MATHEMATICA environment, then solved using AI-based technique utilizing Levenberg Marquardt Feedforward Algorithm. In this work, flow characteristics under varying physical parameters have been studied and analyzed and the boundary layer phenomena has been investigated. In detail horizontal, vertical velocity profiles as well as temperature distribution are analyzed. The findings reveal that as the stretching ratio of the surface coincide with an increase the vertical velocity as the surface has thinned in this direction minimizing resistance to the fluid flow. Full article

Magnetohydrodynamic (MHD) flow and heat transfer in porous media are central to many engineering applications, including heat exchangers, MHD generators, and polymer processing. This study examines the boundary layer flow and thermal behavior of an electrically conducting viscous fluid over a porous stretching tube. The model accounts for nonlinear thermal radiation, internal heat generation/absorption, and Darcy–Forchheimer drag to capture porous medium resistance. Similarity transformations reduce the governing equations to a system of coupled nonlinear ordinary differential equations, which are solved numerically using the BVP4C technique with Response Surface Methodology (RSM) and sensitivity analysis. The effects of dimensionless parameters magnetic field strength (M), Reynolds number (Re), Darcy–Forchheimer parameter (Df), Brinkman number (Br), Prandtl number (Pr), nonlinear radiation parameter (Rd), wall-to-ambient temperature ratio (rw), and heat source/sink parameter (Q) are investigated. Results show that increasing M, Df, and Q suppresses velocity and enhances temperature due to Lorentz and porous drag effects. Higher Re raises pressure but reduces near-wall velocity, while rw, Rd, and internal heating intensify thermal layers. The entropy generation analysis highlights the competing roles of viscous, magnetic, and thermal irreversibility, while the Bejan number trends distinctly indicate which mechanism dominates under different parameter conditions. The RSM findings highlight that rw and Rd consistently reduce the Nusselt number (Nu), lowering thermal efficiency. These results provide practical guidance for optimizing energy efficiency and thermal management in MHD and porous media-based systems.: Full article

This article conducts intermittent tensile deformation on 304 stainless steel; observes the microstructure, mechanical properties, and corrosion performance evolution of stainless steel under different deformation conditions; and reveals its mechanisms. The results indicate that the performance of 304 stainless steel is significantly affected by the degree of intermittent deformation. Small intermittent deformation can produce a good microstructure with uniform distribution, low martensite content, and weak texture, optimizing comprehensive mechanical properties by improving ductility, yield strength, and tensile strength. On the contrary, excessive intermittent deformation increases martensitic transformation and enhances texture, leading to a transition from ductile fracture to brittle fracture. In addition, small intermittent deformations improve corrosion resistance by promoting the formation of a stable passivation film. The microstructural changes affect the deformation mechanism and surface passivation film of stainless steel, making its mechanical strength and corrosion resistance superior to larger intermittent deformation amounts. Small intermittent deformation can improve the mechanical and corrosion properties of 304 stainless steel. This study provides a reference for the formation and performance control of metal materials and has certain practical value. Full article

Objectives: The aim of this study was to compare the effects of eight-week hamstring stretching programs, implemented at different times during physical education classes (i.e., warm-up, cool-down, and both periods), on primary schoolchildren’s back-saver sit-and-reach scores. Methods: A total of 275 schoolchildren (141 females and 134 males; age 8.82 ± 1.63 years) were divided into four groups: the WUG performed stretching during warm-up, the CDG during cool-down, and the MXG during both. The NSG followed the standard classes of physical education without any stretching. During physical education classes WUG, CDG, and MXG performed a 4 min stretching program twice a week. Hamstring extensibility was assessed before and after the program using the back-saver sit-and-reach test. Results: The CDG is the one that achieved statistically significant improvements compared with the WUG, MXG, and NSG (p ≤ 0.01; d = 0.50–0.71). Moreover, the CDG statistically increased the percentage of schoolchildren achieving healthy hamstring extensibility from pre-intervention (49%) to post-intervention (66%). Conclusions: This knowledge could guide teachers to design programs that guarantee feasible and effective development of hamstring extensibility in the physical education setting. Full article

Optimal recovery supports health and enhances performance in soccer players, yet the empirical evidence on various recovery strategies in soccer is complex to interpret. This review aimed to summarize the literature on post-exercise recovery modalities in male and female soccer players of all ages and competition levels. Following PRISMA guidelines, PubMed, SPORTDiscuss, and Web of Science were systematically searched until 17 October 2023. Randomized controlled trials or within-subjects crossover design studies that examined the effects of post-exercise recovery interventions on physical, psychological, or performance outcomes in soccer players were included. A single reviewer extracted data and assessed study quality using the Physiotherapy Evidence Database (PEDro) scale. Overall, 41 studies were included in the final review. The recovery strategies represented in these studies were organized into the following categories: active recovery, blood flow restriction, cold water immersion, contrast water therapy, compression garments, active cool-down, cryotherapy, cold garments, sleep and daytime nap, pneumatic cooling, foam rolling, mindfulness interventions, nutritional intervention, and static stretching. The findings demonstrated that cold-water immersion consistently improved jump performance and perceptions of fatigue, soreness, and overall well-being. Other recovery strategies, such as active recovery, compression therapy, sleep interventions, and nutrition supplementation, also positively impacted recovery, albeit with varying levels of effectiveness and evidence. However, the studies exhibited heterogeneity in methods, outcome measures, and recovery intervention protocols, posing challenges for generalizability. This review summarizes recovery strategies for soccer players, emphasizing the need for practitioners, coaches, and athletes to individualize interventions based on athletes’ needs, preferences, and competition level. Full article

This work aims to apply polymeric PBAT/PLA fibers electrospun with TiO₂ in the photodegradation of the dye Red BF-4B in an aqueous solution and the dye’s subsequent reuse. Initially, the influence of the solution pH was evaluated, and the results showed more significant dye degradation at pH values below the pHpcz (7.42). Kinetic studies show that at 15 mg·L⁻¹, the highest percentage of degradation occurs at 600 min of reaction time; however, degradation equal to (or greater than) 65% was observed at all evaluated concentrations, with the kinetic data being well fitted by the pseudo-first-order model. Additional studies demonstrated the reuse of polymeric films for dye removal, with removal efficiencies ranging from 86.60% to 93.07% over six consecutive reuse cycles. Each cycle consisted of a 600 min removal process, simulating repeated practical applications. After the photocatalytic process, the polymeric fibers remained cylindrical, with several fractures. Diameter decreases of 31.61% and 7.95% were observed after the first and sixth cycles, respectively, with possible exposure of TiO₂. The vibrational spectra indicate changes in the bands at 1755 and 1714 cm⁻¹, attributed to C=O (PLA) and C-O (PBAT) stretches, respectively, suggesting a possible conformational change in the polymers. The thermal profiles showed only slight changes after the cycles. X-ray diffractograms indicate that degradation of the polymeric matrix leads to greater exposure of the embedded TiO₂ particles. The combined results from different characterization techniques provide evidence of the degradation of the polymeric material. Full article

This study aimed to evaluate the impact of an 8-week reverse Nordic exercise training (RNET) program on physical fitness in male youth soccer players. A total of 35 players participated in the study and were divided into two groups: the RNET group (n = 19, age 16.39 ± 0.46 years) and the active control group (CG: n = 16, age 16.53 ± 0.48 years). To assess fitness changes, participants were tested on linear sprint speed (5, 10, and 20 m sprints), change-of-direction (CiD) speed (505-CiD), vertical jump (countermovement jump [CMJ]), horizontal jump (standing long jump [SLJ]), drop jump (20 cm drop jump [DJ-20]), and repeated sprint ability (RSA). Significant group-by-time interactions were observed (effect size, [ES] = 0.70 to 1.37), with substantial improvements in the RNET group across linear sprint, CiD, and jumping performances (ES = 0.61 to 1.47), while no significant changes were noted in the CG. However, no significant group-by-time interactions were observed for RSA parameters. Individual response analysis revealed that 63–89% of RNET group exhibited improvements exceeding the smallest worthwhile change (SWC_0.2) threshold. These results suggest that the RNET program is both effective and safe for enhancing physical fitness in male youth soccer players. Full article

Biodegradable polymers offer a promising solution to the growing issue of global microplastic pollution. To effectively replace conventional plastics, it is essential to develop strategies for tuning the properties of biodegradable polymers without relying on additives. Biaxial stretching promotes anisotropic crystallization in polymer domains, thereby altering the mechanical performance of polymer blends. In this study, we employed a design of experiment (DoE) approach to investigate the effects of biaxial stretching at three drawing temperatures (T_ds) and draw ratios (λs) on a biodegradable blend of poly(lactic acid) (PLA) and poly(butylene adipate-co-terephthalate) (PBAT), aiming to optimize both the strength and ductility. The DoE analysis revealed that the composition, the λ, the interaction between the λ and composition, and the interaction between the T_d and composition significantly affect the elongation at break (ε_Break). For the stress at break (σ_Break), the most influential factors were the interaction between the λ and PLA concentration; a three-way interaction among the λ, PLA, and T_d; the T_d; the λ; and finally the PLA concentration alone. The optimal ε_Break and σ_Break were achieved at a λ = 5 × 5 and T_d = 110 °C, with a composition of 10% PLA and 90% PBAT. The stretched samples exhibited higher crystallinity compared to the pressed samples across all compositions. This work demonstrates that in addition to the composition, the processing parameters, such as the λ and T_d, critically influence the mechanical properties, enabling performance enhancements without the need for compatibilizers or toxic additives. Full article

Polyvinyl chloride (PVC)-dibutyl adipate (DBA) gels are a fascinating dielectric elastomer actuator showing promise in soft robotics. When actuated with high voltages, the gel deforms towards the anode. A recent application of PVC gels in electrohydraulic actuators motivates elastic and hyperelastic constitutive relationships for tensile loading modes. PVC gels with plasticizer-to-polymer weight ratios of 2:1, 4:1, 6:1, and 8:1 w/w were evaluated. PVC gels exhibit a linear elastic region up to 25% strain. The elastic modulus decreased with increasing plasticizer content from 288.8 kPa, 56.1 kPa, 24.7 kPa, to 11 kPa. Poisson’s ratio also decreased with increasing plasticizer content from 0.42, 0.43, 0.39, to 0.35. We suggest that the decrease in polymer concentration facilitates a weakly interconnected polymer network susceptible to chain slippage that hinders the network response, thus lowering Poisson’s ratio. Our work suggests that PVC gels can be treated as isotropic and incompressible for large strains and hyperelastic modeling; however, highly plasticized gels tend to act less incompressible at small strains. The power scaling law between the elastic modulus and plasticizer weight ratio showed high agreement, making the elastic modulus deterministic for any plasticizer content. The Neo–Hookean, Mooney–Rivlin, Yeoh, Gent, Ogden, and extended tube hyperelastic constitutive models are investigated. The Yeoh model shows the highest feasibility when evaluated up to 3.5 stretch, showing a maximum normalized root-mean-square-error of 6.85%. Together, these findings establish a constitutive basis for PVC-DBA gels, incorporating small strain elasticity, large strain non-linear behavior, and network analysis while providing suggestive insight into the network structure required for accurately modeling the EPIC. Full article

Control of the friction process in stretch-forming conditions, when creating sheet metal, is essential for obtaining components of the quality required. This paper presents an approach to modelling the friction phenomenon at the rounded edges of stamping dies. The aim of the study is to compare the coefficient of friction (CoF) determined from numerous analytical models available in the literature. Experimental studies were conducted using self-developed bending under tension friction testing apparatus. The test material was low-carbon DC01 steel sheeting. Tests were conducted under lubricated conditions, using industrial oil intended for deep drawing operations. The surfaces of countersamples made of 145Cr6 substrate were modified using the ion implantation of Pb (IOPb) and electron beam melting processes. Variation in the CoF in BUT tests was related to continuous deformation-induced changes in surface topography and changes in the mechanical properties of sheet metal due to the work-hardening phenomenon. Under friction testing with a stationary countersample, the largest increase in average roughness (by 19%) was found for the DC01/IOPb friction pair. The friction process caused a significant decrease in kurtosis values. The results show that the difference between the highest and lowest CoF values, determined for the analytical models considered, was approximately 40%. Full article

Triggering Receptor Expressed on Myeloid Cells 2 (TREM2) is a receptor found in microglia within the central nervous system (CNS) as well as in several other cell types throughout the body. TREM2 has been highlighted as a “double-edged sword” due to its contribution to anti- or pro-inflammatory signaling responses in a spatial, temporal, and disease-specific fashion. Many of the functions of TREM2 in relation to neurological disease have been elucidated in a variety of CNS pathologies, including neurodegenerative, traumatic, and vascular injuries, as well as autoimmune diseases. Less is known about the function of TREM2 in motoneurons and sensory neurons, whose cell bodies and axons span both the CNS and peripheral nervous system (PNS) and are exposed to a variety of TREM2-expressing cells and mechanisms. In this review, we provide a brief overview of TREM2 and then highlight the literature detailing the involvement of TREM2 along the spinal cord, peripheral nerves and muscles, and sensory, motor, and autonomic functions in health, aging, disease, and injury. We further discuss the current feasibility of TREM2 as a potential therapeutic target to ameliorate damage in the sensorimotor circuits of the spinal cord. Full article

The crushing of used drip irrigation tape is a crucial step in the recycling and reuse of drip irrigation tapes. Incomplete crushing and low efficiency are among the main factors restricting its reprocessing. Investigating the fracture characteristics and the mechanism of fracture during the crushing process is key to solving this problem. Therefore, this study constructs a stretching fracture platform to investigate the influence of stretching speed on the fracture characteristics and reveals the fracture mechanism by analyzing fracture morphology, force-displacement curves, fracture energy, and microstructure. The results show that as the speed increases, the limit strain decreased from 117.7% to 38.7%, and the fracture location always occurs at the junction between the necked and non-necked area, the fracture mode transitions from ductile fracture to brittle fracture, the deformation mode shifts from being dominated by elastoplastic deformation to being dominated by elastic deformation, and the mechanical response curve changes from five stages to three stages. When the stretching speed increases from 60 mm/s to 70 mm/s, a jump phenomenon is observed in macroscopic and microscopic. As the speed increases, the total energy absorbed by the drip irrigation tape decreases from 1.29 × 10⁻² J/mm³ to 0.39 × 10⁻² J/mm³. Brittle fracture primarily absorbs energy for the disintegration and fracture of lamellae in the spherulites at the fracture surface. Ductile fracture primarily absorbs energy for the extension of the fibrous structure, and the mechanical properties of the necked area are strengthened, which leads to the fracture location always occurring at the junction between the necked and non-necked area. Full article

With the rapid development of additive manufacturing technology, selective laser melting (SLM) of austenitic stainless steel has been widely used. SLM stainless steel will inevitably deform during service, so it is necessary to study the microstructure and macro properties of post-plastic deformed SLM stainless steel. In this paper, the changes in the microstructure, mechanical properties, and corrosion resistance of SLM304 stainless steel after stretch deformation were studied, and the evolution rules were revealed. The results show that, with an increasing plastic deformation amount, SLM304 stainless steel exhibits grain fragmentation, disordered orientation, and subgrain formation, along with changes in the shape and size of the cellular structure. Additionally, the α’ martensite content inside SLM304 stainless steel rises significantly, while the thickness of the surface passivation film slightly decreases. The analysis shows that the combined effect of the complex microstructure makes the nanohardness of SLM304 stainless steel increase with the increase in the stretch deformation amount while its corrosion resistance deteriorates. Therefore, moderate post-plastic deformation can enable SLM stainless steel to balance excellent mechanical and corrosion properties. This study can not only provide a theoretical reference for the performance optimization of additive manufacturing steel but also provide value for the engineering application of additive manufacturing technology. Full article

Coastal communities and marine ecosystems face increasing risks due to changing ocean conditions, yet effective wave monitoring remains limited in many low-resource regions. This study investigates the use of seismic data to predict significant wave height (SWH), offering a low-cost and scalable solution to support coastal conservation and safety. We developed a baseline machine learning (ML) model and improved it using a longest-stretch algorithm for seismic data selection and station-specific hyperparameter tuning. Models were trained and tested on consumer-grade hardware to ensure accessibility and availability. Applied to the Sicily–Malta region, the enhanced models achieved up to a 0.133 increase in R² and a 0.026 m reduction in mean absolute error compared to existing baselines. These results demonstrate that seismic signals, typically collected for geophysical purposes, can be repurposed to support ocean monitoring using accessible artificial intelligence (AI) tools. The approach may be integrated into conservation planning efforts such as early warning systems and ecosystem monitoring frameworks. Future work may focus on improving robustness in data-sparse areas through augmentation techniques and exploring broader applications of this method in marine and coastal sustainability contexts. Full article

This study reports on green-synthesized zinc oxide nanoparticles (ZnONPs), focusing on their physicochemical characterization, photocatalytic properties, and agricultural applications. Dynamic light scattering (DLS) analysis revealed a mean hydrodynamic diameter of 337.3 nm and a polydispersity index (PDI) of 0.400, indicating moderate polydispersity and nanoparticle aggregation, typical of biologically synthesized systems. High-resolution transmission electron microscopy (HR-TEM) showed predominantly spherical particles with an average diameter of ~28 nm, exhibiting slight agglomeration. Energy-dispersive X-ray spectroscopy (EDX) confirmed the elemental composition of zinc and oxygen, while X-ray diffraction (XRD) analysis identified a hexagonal wurtzite crystal structure with a dominant (002) plane and an average crystallite size of ~29 nm. Photoluminescence (PL) spectroscopy displayed a distinct near-band-edge emission at ~462 nm and a broad blue–green emission band (430–600 nm) with relatively low intensity. The ultraviolet–visible spectroscopy (UV–Vis) absorption spectrum of the synthesized ZnONPs exhibited a strong absorption peak at 372 nm, and the optical band gap was calculated as 2.67 eV using the Tauc method. Fourier-transform infrared spectroscopy (FTIR) analysis revealed both similarities and distinct differences to the pigeon extract, confirming the successful formation of nanoparticles. A prominent absorption band observed at 455 cm⁻¹ was assigned to Zn–O stretching vibrations. X-ray photoelectron spectroscopy (XPS) analysis showed that raw pigeon droppings contained no Zn signals, while their extract provided organic biomolecules for reduction and stabilization, and it confirmed Zn²⁺ species and Zn–O bonding in the synthesized ZnONPs. Photocatalytic degradation assays demonstrated the efficient removal of pollutants from sewage water, leading to significant reductions in total dissolved solids (TDS), chemical oxygen demand (COD), and total suspended solids (TSS). These results are consistent with reported values for ZnO-based photocatalytic systems, which achieve biochemical oxygen demand (BOD) levels below 2 mg/L and COD values around 11.8 mg/L. Subsequent reuse of treated water for irrigation yielded promising agronomic outcomes. Wheat and barley seeds exhibited 100% germination rates with ZnO NP-treated water, which were markedly higher than those obtained using chlorine-treated effluent (65–68%) and even the control (89–91%). After 21 days, root and shoot lengths under ZnO NP irrigation exceeded those of the control group by 30–50%, indicating enhanced seedling vigor. These findings demonstrate that biosynthesized ZnONPs represent a sustainable and multifunctional solution for wastewater remediation and agricultural enhancement, positioning them as a promising candidate for integration into green technologies that support sustainable urban development. Full article