Despite the growing body of research on nanofluids, a systematic bibliometric analysis focusing specifically on the application of response surface methodology (RSM) in predicting their thermal conductivity is notably absent. This study addresses this gap by presenting the first comprehensive bibliometric and statistical review of 321 relevant publications retrieved from Scopus (2013–2024). The novelty of this work lies in its dedicated focus on RSM as a core methodological theme, providing a quantitative and visual mapping of the field’s evolution, key contributors, and research hotspots. Major findings include: (1) a marked surge in annual publications after 2021, underscoring the method’s rising adoption; (2) the identification of India, Iran, and Saudi Arabia as the leading contributing countries, with detailed visualization of international collaboration networks; (3) the determination of core journals, most influential authors, and highly cited articles that have shaped the field; and (4) the extraction of predominant research themes such as optimization, hybrid nanofluids, and sensitivity analysis through keyword analysis. This synthesis offers a foundational reference for researchers, clearly delineates the current research landscape, and identifies emergent trends to guide future studies in the thermal conductivity analysis of nanofluids using RSM.
While well-tested at solar system scales, Newtonian gravity exhibits anomalies at larger scales and accelerations below 10^-9 m/s^2 . Although Yukawa-like modifications can reconcile these anomalies with general relativity up to solar system scales, they face challenges at galactic scales. Notably, gravitational anomalies at accelerations ≤ 10^-9 m/s^2 for separations down to 50 μ m remain undetected experimentally. This paper presents a mathematical framework for Yukawa modification of Newtonian gravity in weak acceleration regimes (≤ 10^-9 m/s^2) and small separations ( ≤ 30 μ m) using an extended space model with an extra dimension. This model suggests a vacuum-sourced inertia effect from peculiar photons, with implications for the Mach principle. These photons’ entanglement scale ( ≤ 30 μ m) hints at the possibility of longer-range photon entanglement via analytic continuation, opening new avenues for research in quantum gravity and cosmology.
Impact loading represents a critical condition affecting the damage tolerance and residual strength of adhesive-bonded composite joints in advanced engineering structures. However, developing a prediction core capable of estimating damage distribution and severity after impact is essential for future condition monitoring of bonded joints. This study investigates the post-impact behavior of glass fiber-reinforced polymer (GFRP) to 2024 aluminum alloy single-lap joints subjected to transverse impacts using drop-weight tests. Specimens were categorized into non-impacted and impacted groups at energy levels of 1 J, 1.5 J, 2 J, and 2.5 J, and subsequently tested under quasi-static lap shear loading to assess residual strength. The originality of this work lies in: (i) developing a coupled numerical framework that integrates an extended three-dimensional Hashin (3D) criterion with a cohesive zone model (CZM) within a user-defined VUMAT to simultaneously capture intralaminar composite damage and adhesive failure under both impact and post-impact conditions, and (ii) establishing a quantitative correlation between impact energy, through-thickness damage modes, and residual joint strength in a hybrid GFRP-aluminum configuration, which has not been previously reported. Results indicate that impact energies between 1 J and 2.5 J lead to strength reductions ranging from 6.5% to 45%, with a transition from cohesive to mixed adhesive/cohesive failure accompanied by fiber breakage. Fiber tension and matrix compression were identified as the dominant damage mechanisms, extending from the impacted surface to the composite-adhesive interface. At the highest impact energy (2.5 J), combined fiber tension damage in the composite and the formation of a circular-shaped damage zone in the adhesive layer caused the maximum strength reduction. Damage within the composite-adhesive interface and adhesive layer was confirmed through failure mode analysis and thermal imaging. To quantify the predictive capability of the proposed numerical framework, the integrated 3D Hashin-CZM model achieved an average prediction error of 3.2% in estimating the post-impact residual lap shear strength across impacted specimens. This represents an average improvement of approximately 4.6% compared with a conventional model employing a 2D Hashin failure formulation, demonstrating the enhanced accuracy and reliability of the adopted multi-site damage modeling approach.
This work explores the geometry and observational signatures of a Schwarzschild black hole immersed in a background composed of a string cloud and a quintessential scalar field, within the broader context of Finsler geometry. The string cloud component introduces anisotropic radial pressure through a dimensionless parameter 𝔞 , while the quintessence field, characterized by ω _𝔮 = -2/3 as the equation of state parameter, modifies the space-time in a way consistent with late-time cosmic acceleration. We further extend this configuration by embedding it in a Finslerian framework via the anisotropy parameter ϵ , taking into account potential violations of Lorentz invariance and incorporating directional dependence in the space-time structure. Our approach centers on understanding the path of photons around the black hole by analyzing null geodesics, the photon sphere, and the effective potential landscape. We derive the shadow radius and impact parameter as functions of 𝔞 , γ , and ϵ , and investigate how each modifies the shadow structure. Constraining these parameters using Event Horizon Telescope observations of M87* and Sagittarius A*, we identify viable bounds consistent with observed shadow diameters. The results indicate that Finslerian corrections influence the bending of light and the deformation of the black hole shadow, suggesting a more general and flexible framework for probing deviations from general relativity in strong-field regimes.
Background Developmental coordination disorder (DCD) is a common neurodevelopmental condition in children, characterized by deficits in both actual motor competence (AMC) and perceived motor competence (PMC). Objective This study aimed to investigate the effects of linear and non-linear perceptual-motor intervention, with or without transcranial direct current stimulation (tDCS), on AMC and PMC in children aged 7-9 years with DCD. Methods A quasi-experimental pre-test-post-test design with four groups was used: (i) Linear pedagogy (LP) perceptual-motor intervention, (ii) non-linear pedagogy (NLP) perceptual-motor intervention, (iii) tDCS combined with perceptual-motor intervention using the LP, and (iv) tDCS combined with perceptual-motor intervention using the NLP. A total of 40 children diagnosed with DCD based on the Movement Assessment Battery for Children-2 were randomly assigned to the groups. Perceptual-motor interventions were delivered over 10 sessions, and tDCS was applied to the right primary motor cortex for 20 min before each training session. Results Results showed that the group receiving NLP combined with tDCS exhibited the greatest improvements in both AMC and PMC compared to all other groups (p<0.001), whereas NLP alone also outperformed LP (p<0.001). Conclusion These findings suggest that combining brain stimulation with NLP can significantly enhance both AMC and PMC in children with DCD. Overall, the study highlights the importance of designing enriched, exploratory, and neuro-enhanced learning environments for the rehabilitation of children with motor coordination difficulties.
