Search Results (91)

Originally introduced in the 1960s by DISA Elektronik as a calibration tunnel for hot-wire anemometers, the Type 55D41 has now been reengineered into a versatile and modern aerodynamic test platform. While retaining key legacy components, such as the converging nozzle and the 55D42 power unit, the upgraded system features a redesigned modular test section with optical-grade quartz windows. This enhancement enables compatibility with advanced flow diagnostics and visualization methods, including PTV, DIC, and schlieren imaging. The modernized facility maintains the precision and flow stability that made the original design widely respected, while expanding its functionality to meet the demands of contemporary experimental research. Its architecture supports the aerodynamic characterization of micro-scale static pressure probes used in aerospace, propulsion, and micro gas turbine applications. Special attention is given to assessing the influence of probe tip geometry (e.g., conical, ogive), port positioning, and stem interference on measurement accuracy. Full article

The paper presents the CNC manufacturing technology of the ”Double fixing fork” part as a module with educational purpose, being designed as a training support for students and other parties, facilitating the practical learning of CNC processing technology. Its technological manufacturing process involved a careful analysis of the geometry, material, tolerances, as well as functional requirements to ensure precision and reliability in operation. The material from which the part was made is a polymer material (PEHD 1000) selected both for its mechanical characteristics and for its compatibility with processing technologies. The results demonstrated high precision and adaptability, reduced execution times and the possibility of achieving complex geometries in a relatively short time. The developed module supports skill development in CNC programming and operation and is suitable for replication in other academic environments. Programming allowed for more precise control of the cutting tool trajectory and processing parameters. The paper represents an important contribution to the training of future specialists, paying special attention to the growing interdisciplinarity in manufacturing technology and the development of technical skills necessary for future engineers in the numerically controlled machinery sector. Full article

This paper introduces an automated calibration system for color filters used in quantitative schlieren imaging, developed in response to prior findings highlighting the need for automation to reduce calibration time, minimize human error, and improve data accuracy and repeatability. Drawing from the authors’ experimental experience and practical application, the system demonstrates a significant enhancement in calibration efficiency—reducing the process from 2–5 h manually to just 15–30 min, representing time savings of up to 90%. Positioning accuracy improves from ±50–100 μm in manual setups to ±1–10 μm through precision-controlled automation, substantially lowering variability and increasing the reliability of pixel calibration curves. While calibration accuracy remains dependent on flow characteristics and post-processing capabilities, the system’s use of larger color filters—validated analytically and experimentally—further increases contrast sensitivity by 10–20%, enhancing the extraction of physical parameters such as velocity, temperature, and pressure fields. The setup features a modular, scalable architecture with a user-friendly interface, making it adaptable to diverse experimental environments and suitable for users at varying levels of expertise. Its iterative optimization and high-throughput capabilities position this system as a robust, flexible solution for advancing schlieren imaging techniques and enabling next-generation optical diagnostics in fluid dynamics research. Full article

This article presents a series of innovative systems developed through student laboratory projects, comprising two autonomous vehicles, a quadrupedal walking robot, an active ankle-foot orthosis, a ball-on-beam balancing mechanism, a ball-on-plate system, and a manipulator arm, all actuated by pneumatic artificial muscles (PAMs). Due to their flexibility, low weight, and compliance, fluidic muscles demonstrate substantial potential for integration into various mechatronic systems, robotic platforms, and manipulators. Their capacity to generate smooth and adaptive motion is particularly advantageous in applications requiring natural and human-like movements, such as rehabilitation technologies and assistive devices. Despite the inherent challenges associated with nonlinear behavior in PAM-actuated control systems, their biologically inspired design remains promising for a wide range of future applications. Potential domains include industrial automation, the automotive and aerospace sectors, as well as sports equipment, medical assistive devices, entertainment systems, and animatronics. The integration of self-constructed laboratory systems powered by PAMs into control systems education provides a comprehensive pedagogical framework that merges theoretical instruction with practical implementation. This methodology enhances the skillset of future engineers by deepening their understanding of core technical principles and equipping them to address emerging challenges in engineering practice. Full article

Metal casting foundries present hazardous working conditions, making traditional training methods costly, time-consuming, and potentially unsafe. To address these challenges, this study presents a Virtual Reality (VR) training framework developed for the Tennessee Tech University (TTU) Foundry. The objective is to enhance introductory training and safety education by providing an immersive, interactive, and risk-free environment where trainees can familiarize themselves with safety protocols, equipment handling, process workflows, and machine arrangements before engaging with real-world operations. The VR foundry environment is designed using Unreal Engine, a freely available software tool, to create a high-fidelity, interactive simulation of metal casting processes. This system enables real-time user interaction, scenario-based training, and procedural guidance, ensuring an engaging and effective learning experience. Preliminary findings and prior research indicate that VR-based training enhances learning retention, improves hazard recognition, and reduces training time compared to traditional methods. While challenges such as haptic feedback limitations and initial setup costs exist, VR’s potential in engineering education and industrial training is substantial. This work-in-progress study highlights the transformative role of VR in foundry training, contributing to the development of a safer, more efficient, and scalable workforce in the metal casting industry. Full article

In this paper, a specific parametric and open-source algorithm for the direct and inverse kinematics of the UR5e Cobot is formulated by using the (n, o, a, p) transformation matrix, along with the inverse matrices, and then implemented in Matlab for numerical validation purposes. Thus, a specific robotized cell that includes novel mechatronic devices has been designed and built at LARM (Lab. of Robotics and Mechatronics) in Cassino in order to experimentally validate the proposed algorithm. In particular, many experimental points to carry out the whole automatic cycle have been detected by using the corresponding teach-pendant tool and joint positions for different UR5e Cobot poses. In addition, this consistent experimental campaign has allowed to evaluate the percentage accuracy of the robot, which can be useful for the practical applications. Therefore, the proposed kinematic model, along with the parametric and open-source algorithm, of the UR5e Cobot can be useful to simulate different applications in several robotized cells with a good reliability with respect to the real program of the robot. Full article

In this study, a conceptual turbine blade model with internal cooling channels was designed and fabricated using the selective laser melting (SLM) process. The optimal manufacturing orientation was evaluated through simulations, and the results indicated that vertical orientation yielded the best outcomes, minimizing support material usage and distortion despite increased manufacturing time. Two configurations were produced, namely, an entire-turbine blade model and a cross-sectional model. Non-destructive analyses, including 3D laser scanning for dimensional accuracy, surface roughness measurements, and liquid penetrant testing, were conducted. Visual inspection revealed manufacturing limitations, particularly in the cooling channels at the leading and trailing edges. The trailing edge was too thin to accommodate the 0.5 mm channel diameter, and the channels in the leading edge were undersized and potentially clogged with unmelted powder. The dimensional deviations were within the acceptable limits for the SLM-fabricated metal parts. The surface roughness measurements were aligned with the literature values for metal additive manufacturing. Liquid penetrant testing confirmed the absence of cracks, pores, and lack-of-fusion defects. The SLM is a viable manufacturing process for turbine blades with internal cooling channels; however, significant attention should be paid to the design of additive manufacturing conditions to obtain the best results after manufacturing. Full article

This study developed inventive and repurposable children’s furniture to improve functionality and extend product lifespan. Unlike typical cribs which serve a single purpose, the proposed design supports multiple functions: crib, cushioned chair, highchair, walker, toilet attachment, pull-up bar, and bed safety rail. Specific dimensions were established, and the correct material selections were made for the selected concept. This was finalised using Autodesk Inventor 2019 that was used for stress analysis, and material optimisation. Usability tests were conducted to compare the proposed invention with single-function products. These tests were discussed in terms of task completion time, space-saving ability, survey feedback, and a REBA of musculoskeletal risk. It was found that the proposed design could be repurposed in a shorter time and save more space. A majority of the survey participants agreed that it performed well in terms of repurposability, design, space-saving ability, usability, comfort, sustainability, and safety. Additionally, the proposed design is cheaper compared to single-function products. Thus, creating inventive and repurposable children’s furniture can contribute to reducing waste and extending the lifespan of children’s furniture through innovative, cost-effective design solutions. Full article

A professional closet with highly efficient disinfection for reusing protective clothing is required to reduce supply and demand and protect the environment. A self-developed ultraviolet-C (UVC) light-emitting diode (LED) package that can emit uniform radiance in a certain distance was developed; and a series of disinfection modules with UVC LED packages were installed in a closet for disinfection. A disinfection module can achieve an over 99.9% disinfection rate of H1N1; E. coli; S. aureus; Pseudomonas aeruginosa; and an over 99% disinfection rate of EV71 within a minute. A 1-min disinfection closet was developed to reuse protective clothing. The closet was well-designed; as well as a series of burn-in tests were performed after the assembly of the closet. The optical and thermal properties of the closet were stable within one minute of a working period during the burn-in test. After disinfection; bacterial filtration efficiency (BFE) and viral filtration efficiency (VFE) were examined on the disposable protective clothing. The disposable protective clothing did not show any degradation after being exposed to UVC for sixty minutes; which means the defensive capability of medical protective clothing can be reused sixty times in light of the self-developed disinfection closet. The disinfection closet provides an efficient method for reusing protective clothing. Full article

In the modern conditions of the growing consumer market for environmentally friendly industries, the issue of optimizing resource-intensive and energy-intensive technological chains is acute. One of the most expensive stages is the storage of grain—raw materials for the production of biodiesel. This is due to there being no unified temperature control system. In this paper, the authors have developed a mathematical model and a hardware–software complex that allows for the measurement of the temperature field in grain storage areas. To address this challenge, the authors employed methodologies derived from spatial distributed systems to construct a mathematical model. The development of a technical device and the implementation of a software module for processing the measured data in C++ Builder were then undertaken. Full article

Background: More effective and automated techniques for disinfecting elevator push-buttons currently need to be developed, especially given that they are frequently touched by hundreds of individuals. Methods: An automatic elevator push-button disinfection device equipped with four 265 nm ultraviolet-C (UVC) light-emitting diode (LED) packages has been developed for disinfection after each touch to reduce the risk of infection. In this paper, the UVC leakage test, UVC LED package reliability test, and bacteria disinfection efficiency test were performed. Results: The disinfection efficiency for Staphylococcus aureus and Escherichia coli can reach over 90% in 10 s, and end users can set multiple disinfection periods in light of their circumstances. The disinfection device is safe for the human body if the distance exceeds 120 mm. The accelerated aging test result demonstrates that the disinfection device is reliable under normal operation and end-users can increase the disinfection time by compensating for the irradiance drop. Conclusions: The automatic elevator push-button disinfection device provides a safe, highly efficient, and stable disinfection solution for elevator push-buttons. Full article

Hearing loss resulting from prolonged exposure to loud noise is known as noise-induced hearing loss (NIHL), and it often affects professionals exposed to occupational sources of high sound levels. Among the professionals chronically exposed to noise, dentists use instrumentation that produces high-frequency noise. In this occupational category, NIHL is estimated to reach a 5% to 20% prevalence of workers. However, dentists and healthcare personnel have no suitable personal protection equipment designed for their needs. The study aims to develop a new individual hearing protection device called the “dynamic earplug”, which protects from high-frequency noise and amplifies speech frequencies. Testing with the Fonix 7000 Hearing Aid Test System showed effective filtering of high frequencies (above 4000 Hz) from dental instruments and a speech frequency amplification of up to 13 dB (500 Hz–1000 Hz). In a trial involving 20 subjects during an 8 h work shift, most participants positively evaluated the device’s esthetics, ease of insertion, comfort, stability, and noise attenuation while still being able to hear patients’ and colleagues’ voices. The dynamic earplug shows promise as an efficient and comfortable hearing protection solution for professionals exposed to high-frequency noise. Full article

In response to the critical demand for innovative solutions to tackle plastic pollution, this research presents a low-cost, fully automated plastic injection molding system designed to convert waste into sustainable products. Constructed entirely from repurposed materials, the apparatus focuses on processing high-density polyethylene (HDPE) efficiently without hydraulic components, thereby enhancing eco-friendliness and accessibility. Performance evaluations identified an optimal molding temperature of 200 °C, yielding consistent products with a minimal weight deviation of 4.17%. The key operational parameters included a motor speed of 525 RPM, a gear ratio of 1:30, and an inverter frequency of 105 Hz. Further tests showed that processing temperatures of 210 °C and 220 °C, with injection times of 15 to 35 s, yielded optimal surface finish and complete filling. The surface finish, assessed through image intensity variation, had a low coefficient of variation (≤5%), while computer vision evaluation confirmed the full filling of all specimens in this range. A laser-based overflow detection system has minimized material waste, proving effective in small-scale, community recycling. This study underscores the potential of low-cost automated systems to advance the practices of circular economies and enhance localized plastic waste management. Future research will focus on automation, temperature precision, material adaptability, and emissions management. Full article

Date palm tree (DPT) and pine tree (PT) needles in forests form a combustible mat, posing fire risks during summer in Pakistan that damage vegetation, wildlife habitats, and biodiversity and impact local livelihoods. In this article, sintered ceramic specimens were prepared at different weight concentrations (DPT5, DPT10, DPT20, and DPT 30 and PT5, PT10, PT20, and PT30) of date palm tree leaf ash and pine tree needle ash as secondary additives in ceramic manufacturing along with primary material kaolinite (China clay). Raw materials composition was analyzed using X-ray diffraction (XRD), taking loss on ignition, water absorption, bulk density, saturated surface dry density (SSD), weight per unit area, and thermal cycling as measurement indexes. The result indicates that loss on ignition increases while increasing the quantity of secondary additives and the maximum increase for DPT30 was 19.6% and for PT30, it was 22.1%. As the secondary additives increase, the water absorption rate also increases and the maximum increase for DPT30 and PT30 is 4.5%. Meanwhile, with the increase in secondary additives, the density decreased; for DPT 30, it was 1457.7 kg/m³ and for PT30, it was 1829.8 kg/m³. Thermal performance was investigated by heating and cooling cycles. It was observed that thermal performances increase with the increase in secondary additives. The results reveal this novel approach has the potential to form a ceramic and good properties can be achieved. The prepared specimens have the potential to be used in the fields of electronics, aerospace, construction, and building engineering, alleviating environmental strain, curbing the exhaustion of China clay reserves, and most importantly, lowering the risk of forest fires in Pakistan. Full article

Emerging solid-state additive manufacturing (AM) technologies have recently garnered significant interest because they can prevent the defects that other metal AM processes may have due to sintering or melting. Additive friction stir deposition (AFSD), also known as MELD, is a solid-state AM technology that utilises bar feedstocks as the input material and frictional–deformational heat as the energy source. AFSD offers high deposition rates and is a promising technique for achieving defect-free material properties like wrought aluminium, magnesium, steel, and titanium alloys. While it offers benefits in terms of productivity and material properties, its low technology readiness level prevents widespread adoption. Academics and engineers are conducting research across various subfields to better understand the process parameters, material properties, process monitoring, and modelling of the AFSD technology. Yet, it is also crucial to compile and compare the research findings from past studies on this new technology to gain a comprehensive understanding and pinpoint future research paths. This paper aims to present a comprehensive review of AFSD focusing on process parameters, material properties, monitoring, and modelling. In addition to examining data from existing studies, this paper identifies areas where research is lacking and suggests paths for future research efforts. Full article