Soft robots, composed of compliant polymers and hydrogels, can safely interact with humans and fragile environments but remain vulnerable to cuts, punctures, and tears, which limit their service life. Self-healing polymers and hydrogels have therefore been proposed as sustainable solutions for soft robotics because they can recover their mechanical and functional properties after damage either autonomously or under mild external stimuli. In parallel, electronic skin (e-skin) platforms are required to endow robots with environmental perception; graphene- and graphene oxide (GO) based conductive, stretchable and self-healing materials have emerged as promising candidates for such skins. In this work, graphene- and GO-based self-healing e-skin systems for soft robotics are evaluated and compared. Polyurethane–GO networks can achieve tensile strengths in the range of 30–80 MPa and toughness values of 250–500 MJ m⁻³ while maintaining mechanical self-healing efficiencies of 80–90 % at room temperature. Photothermally triggered GO composites can further provide 88–99 % healing within 20–60 s under infrared irradiation. Graphene/GO-reinforced hydrogel and elastomer e-skins operate over wide strain ranges (300–850 % and above) and exhibit competitive gauge factors, response times and electrical healing efficiencies compared with state-of-the-art ionic and polymeric self-healing e-skins. Overall, the results indicate that graphene- and GO-based self-healing e-skins are strong candidates for endowing soft robots with both sensing and self-protection capabilities.
Adhesive joints are widely used in the automotive, aerospace, and construction industries because they distribute loads uniformly, join dissimilar materials, and reduce structural weight. However, their long-term performance is strongly affected by creep, the time-dependent deformation of the adhesive layer under sustained loading, which can compromise joint integrity. This study presents a systematic numerical investigation of the combined effects of adhesive layer thickness, fillet geometry, and material reinforcement on the creep behavior of adhesively bonded single lap joints. Finite element simulations were performed in Abaqus using the Norton-Bailey power-law constitutive model, with validation against published results showing a maximum deviation below 7.5%. Four adhesive thicknesses (0.25-0.55 mm) were analyzed at both the elastic (t = 0.1 s) and creep-dominant (t = 4 h) stages. The results show that increasing adhesive thickness reduces peak shear stress and creep strain by approximately 15-25% and 20-30%, respectively, by promoting a more uniform load transfer along the overlap. The introduction of fillets at the overlap edges further mitigates stress concentration, yielding an additional 10-20% reduction in peak stress and strain. Carbon-fiber reinforcement of the adhesive produces the most pronounced improvement, decreasing peak creep strain by 44.68% for Epoxy A and 24.37% for Epoxy B. These findings provide design-level insights for enhancing the long-term durability of adhesively bonded joints through combined geometric and material optimization.
Seismic isolation is a highly effective design strategy to enhance earthquake resistance by reducing the transfer of ground motion to the superstructure. It is widely applied in high-seismicity regions, particularly for buildings with critical functional or strategic importance. This study presents a comprehensive numerical investigation of the seismic performance of masonry wall systems subjected to near-fault earthquakes through a two-level modeling framework. At the global structural level, a total of 32 building models were developed, including fixed-base, sliding-base, and base-isolated configurations. The parametric study considered variations in the number of stories, span lengths, and plan configurations to evaluate the influence of seismic isolation on overall structural response. Nonlinear dynamic analyses under near-fault ground motions were performed to assess base shear, interstory drift, and floor acceleration. At the component level, detailed finite element models of masonry walls strengthened with two to five seismic isolators were developed in Abaqus and subjected to nonlinear cyclic loading. The local response was evaluated in terms of lateral load capacity, hysteretic behavior, energy dissipation, and damage distribution. The results indicate that seismic isolation significantly reduces base shear and floor accelerations at the global level, while increasing displacement demands. Bare masonry walls (unstrengthened) exhibited extensive damage and a maximum lateral force of 3,360 N, while walls with isolators reached 4,803–6,221 N, depending on the number of isolators. Walls with two isolators provided substantial improvement, while additional isolators resulted in diminishing returns, except for the five-isolator configuration, which showed the highest energy dissipation and ductility. Strengthened walls also demonstrated symmetric cyclic responses with minimal local crushing, in contrast to the bare wall, which experienced severe damage in nearly 90% of its area. Overall, the findings demonstrate that properly designed seismic isolation systems can substantially enhance both global and local seismic performance of masonry structures. The study provides practical insights into the optimal number and configuration of isolators for improving structural resilience under near-fault ground motions.
The present study aims to derive an approximate solution for the viscous flow of a fluid past an oblate, continuously and nonlinearly stretched surface. The research provides a mathematical framework for understanding fluid flows and their associated heat transfer characteristics. The novelty of this study lies in its formulation and solution because of the incorporation of nonlinear exponentially stretched oblate surfaces, with thermal-dependent viscosity and conductivity for a more realistic model. By employing a similarity transformation of variables and boundary layer approximation, the governing equations are reduced to a set of highly coupled ordinary differential equations (HODEs) and solved analytically using the regular approximation method. The chosen method offers a computationally efficient alternative for solving such highly nonlinear problems (HNPs). The numerical solutions were obtained via the MATHEMATICA package. It was found that velocity and temperature distributions depend significantly on the transverse magnetic strength and the ratio of fluid kinetic energy to thermal energy. Also, the wall heat flux increases as the Prandtl number rises. Moreover, as the local thermal Grashof and Eckert numbers increase, the momentum and thermal boundary layer thicknesses expand. Thus, this investigation aims to provide insights into optimizing industrial processes involving continuous surfaces, such as extrusion and coating.
Perforated microbeams are widely employed in micro- and nano-electromechanical systems due to their lightweight structures and tunable mechanical properties. At small scales, however, classical elasticity fails to capture size effects and porosity-induced stiffness variations. This study develops a comprehensive framework for the static, dynamic, and electrostatic behavior of perforated Timoshenko microbeams with graded porosity, based on the Chebyshev collocation method. The model integrates nonlocal elasticity to account for size effects, graded porosity distributions to represent realistic microstructural variations, and electrostatic actuation to analyze pull-in instability. Validation against published results confirms the accuracy and efficiency of the proposed approach. Parametric investigations reveal that porosity distribution strongly affects stiffness and deflection responses, while size-dependent effects enhance rigidity and increase natural frequencies. Electrostatic pull-in voltage is found to increase with both porosity ratio and length scale parameter, indicating improved stability for micro- and nano-electromechanical systems devices. The findings demonstrate that the Chebyshev collocation method framework provides a robust and efficient tool for the design and optimization of next-generation perforated microstructures.
The increasing number of construction projects has led to a growing demand for deep-supported excavations. Identifying the key parameters affecting cost is essential. Deep excavation design is influenced by multiple factors, including soil conditions, excavation depth, and support system characteristics. Additionally, ensuring excavation safety requires adherence to specific criteria related to displacement and stress limits. This study presents a parametric investigation focusing on the influence of pile diameter on excavation costs. Numerical analyses were conducted using PLAXIS, integrated with Python through the PLAXIS API, to automate simulations. Various soil types and excavation depths were considered. The design, construction, and performance of deep excavations involve competing mechanisms, where improved displacement control through larger pile diameters is achieved at the expense of increased internal forces and cost.
Multi-motor drive systems are widely used in modern applications that require precise synchronization of speed or torque, particularly when motors are mechanically coupled to a common load. A lack of proper coordination leads to unbalanced torques, mechanical stress, and vibrations, which ultimately reduce system efficiency. Maintaining reliable synchronization remains challenging due to system asymmetries and the limitations of conventional centralized or master–follower approaches. This study introduces a control strategy for three Permanent Magnet Synchronous Motors (PMSMs) rigidly coupled to a single shaft. In the experimental setup, three synchronization methods were implemented: Parallel, Torque-Follower, and the proposed Multilateral control. Each motor is driven by an independent controller and driver unit. Depending on the selected topology; these units perform either torque control or integrated velocity and torque control. Comparative results show that the proposed Multilateral control improves torque and velocity synchronization. It reduces mean squared errors compared to Torque-Follower method and provides more balanced torque distribution than Parallel under both no-load and loaded conditions. These findings show its potential as a scalable solution for advanced multi-motor applications.
Geosynthetics made from synthetic polymers are widely used in geotechnical engineering for soil reinforcement, separation, erosion prevention, and drainage. These materials have applications in landfills, foundations, retaining walls, and dams. The interaction between geosynthetics and the surfaces they meet needs to be investigated to ensure that geosynthetics are efficient in their function. The present study examined the interface shear behaviour between granular soil and a High-Density Polyethylene (HDPE) geomembrane. A cylindrical direct shear test based on the discrete element method (DEM) was conducted on HDPE geomembranes with thicknesses of 1.5 mm and 3.0 mm. Preliminary experiments were performed solely on granular soil, after which a concrete block was placed in the lower jaw of the shear box with the geomembrane positioned on top, while the soil in the upper jaw formed the soil–geomembrane interface. Various normal stresses and shear rates were applied to analyse geomembrane behaviour. According to the DEM results, the interface friction angle for the 1.5 mm HDPE–soil configuration was reduced by approximately 51–59% compared to granular soil. For the 3.0 mm HDPE–soil interface, the reduction ranged from 42% to 48%, depending on the shear rate. These reductions, representing decreases in internal friction angle from roughly one-third to two-thirds, were found to be consistent with ASTM standards.
There are difficulties in determining the properties of nano-sized materials such as bending, buckling and vibration with classical elasticity theories. For this reason, researchers have developed many theories that include the size effects of micro- and nano-sized structures. In this study, the bending equations of a boron nitride nanotube cantilever nanobeam under different loadings are obtained according to the modified couple stress theory and Euler-Bernoulli beam theory and the results are compared.
Climate change and sustainable development hold critical significance for all communities. A major driver of climate change is the rise in carbon emissions, which is fueled by factors like population growth, economic development, technological advancements, migration, and national governance strategies. This trend underscores that industrialized nations play a substantial role in contributing to global carbon emissions. The effects of climate change are evident in increasing temperatures, decreased rainfall, changes in water resource potential, and variations in streamflow patterns. These consequences, especially in developing nations, result in population movements, migration waves, changes in agricultural and commercial production, and profound socio-cultural shifts within societies. In Turkey, the most significant effect of climate change is evident in the potential of its water resources. Despite this, the public largely fails to acknowledge the issue, and there is a common misconception that Turkey will not experience water shortages. However, recent droughts and climate-related changes highlight the seriousness of this threat. This research examines the variations in yearly average temperatures in the Aksu Basin, in Antalya Province, as affected by climate change. Historical temperature records from the area were analyzed using MATLAB's Curve Fitter Toolbox, and various polynomial regression models were employed. The regression analysis was used to predict future temperature values for the region. Among the models tested, the linear (first-degree polynomial) model yielded the most accurate results. This model suggests that the annual average temperature in the area could rise by about 0.003°C
This paper provides a thorough analysis of the axial vibration behavior of nanoring rods based on nonlocal elasticity theory, highlighting its relevance to nanoscale systems. The equation governing the axial vibration of nanoscale rods under nonlocal effects is formulated. By applying appropriate transformations to this equation, the frequency equation is derived. Additionally, a nonlocal finite element formulation for the rod is developed using the weighted residual method.
European cybersecurity is rapidly evolving to address complex and emerging threats fueled by advancements in technology. AI-powered threat analysis has become a cornerstone, enabling faster detection of anomalies, predictive threat modeling, and real-time incident response. As Europe enters the quantum age, cybersecurity strategies are increasingly focused on quantum-resistant encryption to protect critical infrastructure and sensitive data from future quantum attacks. Simultaneously, the rise of blockchain technologies and cryptocurrencies introduces new vulnerabilities, such as smart contract exploits and decentralized finance (DeFi) fraud, requiring targeted regulatory oversight. In response, the EU is strengthening its regulatory frameworks, such as the NIS2 Directive and the Digital Operational Resilience Act (DORA), to ensure a harmonized, proactive approach to cybersecurity governance, resilience, and accountability across sectors. This multifaceted strategy reflects Europe’s commitment to safeguarding digital sovereignty and fostering trust in its digital ecosystem. The study deals with the transformation of the European cyber security ecosystem within the framework of artificial intelligence (AI) supported threat analysis. The paper discusses the security risks that arise in the quantum and post-quantum era, the possibility of blockchain/crypto systems being broken by quantum computers, the limitations of the existing data set, and the need for human-like thinking skills. In addition, the European Union's (EU) cybersecurity policies, data privacy principles, ethical standards, transparency, accountability, and human-centered AI design approaches are examined within the scope of the EU's global norm-setting role. This article also aims to shed light on the strategic steps that will shape the future of AI-powered cyber defense. Study shows that Europe should develop artificial intelligence (AI)-powered cybersecurity solutions in its preparations for the post-quantum era, it also should invest in AI models that transcend current data set limits and have humanoid thinking capacities.
This paper deals with the investigation of the vibrational behavior of aluminum cantilever beams for various slenderness ratios. Analytical solutions based on the Bernoulli-Euler beam theory are compared with the results from SOLIDWORKS. The first three natural frequencies are analyzed, highlighting the influence of beam length and mode number. The results demonstrate that the Bernoulli-Euler beam theory provides accurate results for high slenderness ratios and lower modes, while SOLIDWORKS offers reliable results for practical applications. The findings contribute valuable insights into the design and analysis of structural elements, particularly for nanomechanics studies. This study presents a rare and comprehensive dataset, systematically comparing analytical theory with finite element method simulations performed on beams with varying slenderness ratios.
The present research was focused on modeling the sloshing of a liquid in a rectangular tank with varying heights of kerosene-air and water-air mixtures using the Volume of Fluid (VoF) model. The study's goal was to analyze the influence of the fluid type and fill level on dynamic pressure and turbulence kinetic energy in the tank. Two different fill levels (50% and 75%) were used and the outcomes for kerosene-air and water-air mixtures were compared. The results showed that models with kerosene generated larger dynamic pressure and higher turbulence kinetic energies as compared to water-filled ones. In the 75% case of kerosene, the highest dynamic pressure was about 2.3 kPa, whilst the pressure in the water-filled model was lower. A similar pattern was evident for turbulence kinetic energy, as the levels in models with kerosene were much bigger. This difference is attributed to the higher viscosity of kerosene, which creates greater resistance during sloshing. Overall, the study demonstrates that fluid type, viscosity, and fill level are the key factors in sloshing dynamics and must be prioritized in tank design.
This paper presents a comprehensive analysis of the torsional vibration of circular rods using nonlocal elasticity theory, emphasizing its applicability in nanoscale systems. The equation of motion for nonlocal torsional vibration of nanoscale rods is first derived. After applying some transformations to the obtained equation of motion, the frequency equation is formulated. In addition, a nonlocal finite element model (NL-FEM) for the rod is developed using the weighted residual method.
In this research article, a free vibration analysis study of nanorings using nonlocal elasticity has been attempted. Nanorings are involved in many areas of our lives. It is seen that nanorings are frequently used, especially in technological tools. In this study, firstly the studies carried out by scientists on nanorings are discussed comprehensively. In particular, these studies are related to the theory of nonlocal elasticity and the vibration of nanorings. In this context, after a literature review, an attempt was made to express the theory of nonlocal elasticity. By using the simplest equations of the nonlocal elasticity theory, the main equation of this theory was obtained. While obtaining the main equation, a number of mathematical functions are used from the simplest equations. It has been seen that the main equation obtained in the nonlocal elasticity theory for nanorings has been used in many studies. After the theory of nonlocal elasticity, the free vibration of nanorings is discussed. Here, mathematical equations are used in the environment embedded in elastic soil. In addition, new mathematical equations are crated by taking the ''"k" _"m" '' value to zero in order to get rid of the elastic embedded environment, that is, the ground effect. Here, the free vibration dimensionless frequency equation of nanorings is obtained. As a result, mathematical equations regarding the theory of nonlocal elasticity and the free vibration of nanorings are derived.
In this study, the free vibration behavior of functionally graded Timoshenko beams is analyzed. The equations of motion are derived using Hamilton’s principle, resulting in fourth-order differential equations. By solving these equations, displacement and rotation functions are obtained. Applying appropriate boundary conditions yields a system of four linear equations, which constitute the coefficient matrix for various support scenarios. The fundamental frequencies are determined by identifying the points where the determinant of this matrix equals zero. To efficiently locate these points, a novel iterative method is proposed. The results are validated through comparisons with existing studies in the literature and are illustrated with comprehensive tables and figures.
This article provides a detailed examination of the historical development and areas of use of aviation materials. By investigating the fundamental properties of materials used in aircraft and aerospace vehicle design, such as durability, lightness, heat resistance, and corrosion resistance, the study aims to offer an important perspective from both engineering and industrial viewpoints. Additionally, the role of material selection in factors like flight safety, efficiency, and environmental impact is discussed. The field of aviation materials is a fundamental element of aerospace engineering, encompassing many areas such as aircraft technology design, aerodynamics, flight control systems, avionics, propulsion systems, fuselage structures, and other critical disciplines. Launching a vehicle, whether an aircraft or a spacecraft, requires significant thrust and energy to initiate and sustain flight. Reducing engine weight to improve performance, while maintaining thrust capabilities, is of critical importance. Achieving these advancements requires the use of new materials that offer higher melting points, enhanced durability, and longer lifespans. As a result, materials such as polymer composites and magnesium alloys are in demand. With the advancement of superalloy technology, faster and more powerful aircraft for passenger, cargo, and other aviation applications are expected. This article aims to explore the historical development and applications of aviation materials.
This study investigates the bending response of perforated nanobeams resting on Winkler-Pasternak elastic foundation (WPEF), using Eringen's theory of nonlocal elasticity (ENET). The analysis examines how various parameters affect the mechanical response of the nanobeam, including the nonlocal parameter, foundation parameters, filling ratio, and number of holes. Results indicate that an increase in the nonlocal parameter produces larger transverse displacements compared to classical beam theory, while the stiffness decreases due to nanoscale effects. The elastic foundation parameters significantly influence beam behavior, with the Pasternak model proving more effective than the Winkler model (WEF) in reducing displacement. Analysis of hole properties reveals that higher filling ratios increase beam stiffness, while an increase in the number of holes decreases nanobeam stiffness. These findings are crucial for optimizing the design of nanoelectromechanical systems and other nanostructured devices where bending behavior affects performance.
Afghanistan faces significant challenges in meeting its growing energy demands, with the building sector consuming a substantial portion of its energy supply. The country increasingly turns to solar energy as a clean and sustainable alternative to address these challenges. While previous studies have explored solar energy potential in Afghanistan, there is a lack of comprehensive research focusing on building sector applications and the interplay of climatic and geometrical factors. This study aims to assess the potential of solar energy for the building sector in Afghanistan by examining the influence of climatic and geometrical factors. A systematic literature review was conducted to identify existing research and data on solar energy resources, building characteristics, and energy consumption patterns. The findings reveal that Afghanistan possesses substantial solar energy potential, particularly in the southwest and west regions. Building orientation, insulation, and shading are identified as crucial factors influencing solar energy performance. By exploring the suitability of various solar technologies, including solar photovoltaic, solar thermal, and solar lighting systems, this research contributes to the knowledge base on solar energy in Afghanistan. It provides insights for policymakers and practitioners seeking to promote sustainable building practices.
