Quadrupedal animals leverage flexible spines to achieve agile locomotion, yet most robotic counterparts, like the Kemba robot, retain rigid or revolute spinal joints, limiting dynamic performance. While prior studies suggest that prismatic spines enhance acceleration in quadruped robots, these often neglect physical actuator constraints inherent in real-world systems. This study investigates spine morphology—rigid, revolute, and prismatic—on the steady-state bounding of Kemba using a dynamics-driven framework. Planar models for each spine configuration integrate actuator torque, velocity, and piston force constraints, alongside complementarity conditions for ground and valve contact interactions. A second-order Radau contact-implicit direct collocation method optimises trajectories using a bio-inspired contact sequence derived from cheetah and greyhound gaits. Results demonstrate the prismatic spine’s superiority in stride length and velocity over rigid and revolute designs, attributed to enhanced leg extension and ground reaction force alignment. The prismatic spine also exhibits energy storage potential through linear actuation, suggesting efficiency gains. These findings underscore the importance of co-optimising spine morphology and actuator constraints in bio-inspired robots. This work bridges simulation-based biomechanics with practical robotic design, advancing Kemba’s capabilities. Future efforts will experimentally validate these models through the physical integration of a prismatic spine.

The coal preparation industry faces increasing challenges, marked by escalating capital and operational costs since 2019, alongside stricter environmental, social, and governance regulations. To navigate these obstacles, there is a growing emphasis on implementing advanced processing and blending strategies, necessitating the use of data science and analytics. Operations are increasingly investing in dedicated remote operations centres and individual site analytics to optimize short-term and long-term operational efficiency, enhancing profitability across the entire mine site. This evolution includes the development of geometallurgical modelling software designed to maximize returns from coal resources by analysing resource databases and financial models to assess various processing strategies. Enhanced capabilities using R Shiny coding and Power BI visualizations enable swift evaluations of infrastructure investments and production strategies over the mine's lifespan. The tool's application extends to individual equipment strategies, focusing on efficiency metrics to determine optimal feed rates and necessary upgrades. A series of case studies illustrate the practical use of this technology for scheduling capital improvements and optimizing supply chain dynamics for ROM and product stockpiling across multi-seam operations, ensuring resource management aligns with financial and operational goals.

The present study focuses on the correlation between dielectric and tribological behavior of insulating materials, with a particular focus on glass fibre reinforced epoxy composites. This interaction is demonstrated through tribological testing and SEM mirror effect analyses conducted on a neat epoxy and two glass fibre reinforced epoxies that differed solely in their fiber sizing. The interfaces between fibre and matrix function as a diffusion path, trapping electric charges, thereby promoting defect generation. It is also important to note that the transfer of charges across the interfaces helps to stabilise the coefficient of friction and decrease the wear by reducing the accumulation of polarization energy. However, it should be noted that interfacial charge trapping has been identified as a contributor to degradation. The selection of a tailored sizing process enables precise modulation of charge dynamics, thereby optimising the mechanical performance and tribological durability of composites.

Silicon is a cost-effective alloying element added to low carbon steel for improved strength, while maintaining ductility and formability. During hot rolling Si-alloyed steel forms uneven patches of red oxide scale over the surface. These patches are difficult to remove by industrial pickling processes. The influence of slab surface temperature on the descalability of fayalite was investigated. When hydraulic descaling is executed at a slab surface temperature higher than the melting point of fayalite (1177°C), the liquid fayalite is washed away. The red oxide scale coverage of the surface was decreased significantly.

This paper proposes a methodology to convert thin film nanoindentation load-displacement curves into tensile stress-strain curves. An optimization procedure, based on the trust-region reflective algorithm, is established to identify a unique set of three elastoplastic properties: Young’s modulus, yield stress and the strain hardening coefficient of the coating materials. The uniqueness issue of the optimization results is addressed by choosing initial guess parameters closer to the target values. The initial guess parameters are provided by the Jönsson and Hogmark model. The optimal elastoplastic properties of the coatings including, Young’s modulus (E), yield stress (σy) and work hardening exponent (n), are used to generate the true stress-strain curve. The presented methodology is validated on CrAlN monolayer coatings with different aluminum content. The results show good agreement between the simulated and the experimental nanoindentation load-displacement curves and as a result, the true stress-strain curve of the studied monolayer coatings is built successfully. These findings provide valuable insight for evaluating the elastoplastic properties of monolayered systems in order to optimize their structure.

The case study is about the repair of a bridge column in the Baltic Sea which had been constructed with low concrete cover in some areas and also exhibited signs of ASR. Therefore, a repair mortar had been chosen which is designed for use both on structures suffering ASR and a marine environment. During a test repair on one of the damage-/breakout areas the possibility of incipient anode formation had to be in mind, because the original concrete had a generally increased chloride content. Initial potential surveys on and around the repair spot ca. 3 weeks after the concrete placement/ spraying showed no changes in the original concrete close to the repair area, and the potential values in the repair area were about 200 mV more positive. Enhanced corrosion measurements resulted in a sound passive behaviour of the rebar in the original concrete. Very unexpectedly, the reinforcement embedded in the repair mortar was in an active state at low polarisation and electrolyte resistances – despite the more positive potentials, which dropped by ca. 100 mV after a minute of wetting the surface. Dust samples of the repair mortar were analysed for pH value, which were about 12.3 and possibly not sufficiently basic to establish passivity on the reinforcement which had a slight, covering layer of corrosion products from the recent air exposure over the whole area. It was agreed to thoroughly clean the rebar in other repair spots before spraying the repair mortar there and to watch for the corrosion behaviour on all repair spots. Apparently, the passivation of the reinforcement in the repaired areas is retarded at the observed low pH values and can take several week or months. This seems to be beneficial for avoiding the formation of incipient anodes around the repair area. At the time of writing the manuscript final measurements to prove this are scheduled.

Retrieving marine drifter buoys is often resource-intensive, requiring vessels and personnel to locate and recover floating sensors manually. This paper presents a fully autonomous quadrotor drone system designed to retrieve marine buoys using computer vision and a custom lightweight gripper. An ArUco marker affixed to the buoy enables visual pose estimation from a downward-facing camera. A gripper that doubles as landing gear minimises the payload weight. The control architecture integrates a Pixhawk flight controller for low-level stability and a Raspberry Pi running ROS for vision processing and mission logic. In indoor trials, the system achieved an 80% success rate in marker detection and 95% manual grasping success. Precision descent resulted in a 53 mm average error. Integration of the gripper into the landing structure increased flight time from 8.7 to 12.5 minutes. This research demonstrates the feasibility of autonomous aerial retrieval and identifies enhancements required for open-water deployment.

The bipolar plate is a core component of a fuel cell and makes a decisive contribution to both system weight and cost. To reduce costs, metallic foils have been formed for several years to replace the conventional milled compound plates. The main challenge in forming is that the channel geometries must be produced with the highest accuracy requirements. Tolerances of a few micrometers should be maintained. The combination of high accuracy requirements with target production speed of less than one second and the complex geometric designs of flow fields pushes conventional forming technologies to their process limits. To meet this challenge, a procedure for feature-based forming has been developed (IDDRG2024) that enables multi-stage and hybrid forming. This allows bipolar plates to be manufactured independently of design but in a feature-specific production process. This previously developed theoretical process model will be physically validated and tested for effectiveness in investigations to be presented. For this purpose, a hybrid tool consisting of conventional stamping and rubber pad forming is set up, which is combined using precision workpiece transport. Using this tool, hybrid forming tests can be carried out based on previous numerical analysis to validate the procedure and derive an optimized process chain.

The Moroccan medina is characterized by clay-brick masonry edifices, which can be structurally vulnerable because of their limited seismic resistance. Therefore, some kind of intervention is sought to improve the structural performance of these traditional buildings. This paper presents a numerical investigation of the behavior of masonry walls under gravitational, compressive, and cyclic lateral loads, using an explicit finite element model following the simplified micro-approach. The numerical results prove that the shear response can be impacted by stress redistribution despite the lateral loading being primarily in the vertical di-rection. Thus, this study is foundational for future studies on seismic vulnerability and retrofitting of masonry construction.

The aim of work is to present experimental results for the evolution of surface roughness and waviness parameters with plastic strains in uniaxial and biaxial stretching tests of Interstitial Free-IF steel thin-sheet. Additionally, investigate the correlation between experimental FLC and Forming Limit Waviness curves of Wt*, FLW, by displaying them on the same Map of Principal Surface Limit Strains, MPLS. Material plasticity parameters and strain hardening law were obtained by tensile tests at 0°, 45° and 90° to RD. Nakazima formability tests were performed using the Marciniak's flat head punch for in-plane stretching. Surface roughness and waviness profile parameters such as the maximum distance peak-valley roughness Rt, arithmetic average waviness Wa, total height peak-valley waviness Wt, maximum valley depth Pv were measured during uniaxial and biaxial tests. Nakazima uniaxial and biaxial samples were deformed in incremental steps to determine the negative and positive quadrants of the MPLS of IF steel. From these data, comparison of experimental and predicted local necking curve, FLC-N, by the strain gradient model, using Barlat's Yld 2000-2d yield function, and experimental FLW were plotted. Parameter Wt* is nearly constant between 2.2 and 3.0 µm. Also, curves of roughness and waviness parameters versus equivalent strains were displayed.