Technologies

19 pages, 1914 KiB

Open AccessArticle

Fracture Behavior Assessment of Rubberized Concrete Using Non-Standard Specimens: Experimental Investigation and Model Optimization

by Shuang Gao, Zhenyu Wang, Jiayi Sun, Juan Wang, Yu Hu and Hongyin Xu

Technologies 2025, 13(7), 307; https://doi.org/10.3390/technologies13070307 - 17 Jul 2025

Abstract

With the advancement of modern engineering structures, traditional cement concrete is increasingly unable to meet the mechanical performance requirements under complex conditions. To overcome the performance limitations of materials, modified concrete has become a focal point of research. By incorporating modifying materials such [...] Read more.

With the advancement of modern engineering structures, traditional cement concrete is increasingly unable to meet the mechanical performance requirements under complex conditions. To overcome the performance limitations of materials, modified concrete has become a focal point of research. By incorporating modifying materials such as fibers, polymers, or mineral admixtures, the properties of concrete can be significantly enhanced. Among these, rubberized concrete has attracted considerable attention due to its unique performance advantages. This study conducted fracture tests on rubberized concrete using non-standard concrete three-point bending beam specimens of varying dimensions to evaluate its fracture performance. Employing conventional concrete fracture theoretical models, the fracture toughness parameters of rubberized concrete were calculated, and a comparative analysis was performed regarding the applicability of various theoretical calculation formulas to rubberized concrete. The results indicated that the fracture performance of rubberized concrete varied significantly with changes in specimen size. The initial toughness exhibited a consistent size-dependent variation across different theoretical models. The fracture toughness corresponding to crack height ratios between 0.05 and 0.25 showed contradictory trends; however, for crack height ratios between 0.3 and 0.5, the fracture toughness became consistent. This study integrated boundary effect theory and employed Guinea’s theory to propose an optimization coefficient γ for the double-K fracture toughness formula, yielding favorable optimization results. Full article

(This article belongs to the Topic Application of Concrete Materials in Coastal Port Engineering)

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49 pages, 3444 KiB

Open AccessArticle

A Design-Based Research Approach to Streamline the Integration of High-Tech Assistive Technologies in Speech and Language Therapy

by Anna Lekova, Paulina Tsvetkova, Anna Andreeva, Georgi Dimitrov, Tanio Tanev, Miglena Simonska, Tsvetelin Stefanov, Vaska Stancheva-Popkostadinova, Gergana Padareva, Katia Rasheva, Adelina Kremenska and Detelina Vitanova

Technologies 2025, 13(7), 306; https://doi.org/10.3390/technologies13070306 - 16 Jul 2025

Abstract

Currently, high-tech assistive technologies (ATs), particularly Socially Assistive Robots (SARs), virtual reality (VR) and conversational AI (ConvAI), are considered very useful in supporting professionals in Speech and Language Therapy (SLT) for children with communication disorders. However, despite a positive public perception, therapists face [...] Read more.

Currently, high-tech assistive technologies (ATs), particularly Socially Assistive Robots (SARs), virtual reality (VR) and conversational AI (ConvAI), are considered very useful in supporting professionals in Speech and Language Therapy (SLT) for children with communication disorders. However, despite a positive public perception, therapists face difficulties when integrating these technologies into practice due to technical challenges and a lack of user-friendly interfaces. To address this gap, a design-based research approach has been employed to streamline the integration of SARs, VR and ConvAI in SLT, and a new software platform called “ATLog” has been developed for designing interactive and playful learning scenarios with ATs. ATLog’s main features include visual-based programming with graphical interface, enabling therapists to intuitively create personalized interactive scenarios without advanced programming skills. The platform follows a subprocess-oriented design, breaking down SAR skills and VR scenarios into microskills represented by pre-programmed graphical blocks, tailored to specific treatment domains, therapy goals, and language skill levels. The ATLog platform was evaluated by 27 SLT experts using the Technology Acceptance Model (TAM) and System Usability Scale (SUS) questionnaires, extended with additional questions specifically focused on ATLog structure and functionalities. According to the SUS results, most of the experts (74%) evaluated ATLog with grades over 70, indicating high acceptance of its usability. Over half (52%) of the experts rated the additional questions focused on ATLog’s structure and functionalities in the A range (90–100), while 26% rated them in the B range (80–89), showing strong acceptance of the platform for creating and running personalized interactive scenarios with ATs. According to the TAM results, experts gave high grades for both perceived usefulness (44% in the A range) and perceived ease of use (63% in the A range). Full article

(This article belongs to the Special Issue Assistive Technologies in Care and Rehabilitation: Research, Developments, and International Initiatives)

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27 pages, 2333 KiB

Open AccessArticle

SWOT-AHP Analysis of the Importance and Adoption of Pumped-Storage Hydropower

by Mladen Bošnjaković, Nataša Veljić, Jelena Topić Božič and Simon Muhič

Technologies 2025, 13(7), 305; https://doi.org/10.3390/technologies13070305 - 16 Jul 2025

Abstract

Energy storage technologies are becoming increasingly important when it comes to maintaining the balance between electricity generation and consumption, especially with the increasing share of variable renewable energy sources (VRES). Pumped storage hydropower plants (PSHs) are currently the largest form of energy storage [...] Read more.

Energy storage technologies are becoming increasingly important when it comes to maintaining the balance between electricity generation and consumption, especially with the increasing share of variable renewable energy sources (VRES). Pumped storage hydropower plants (PSHs) are currently the largest form of energy storage at the grid level. The aim of this study is to investigate the importance and prospects of using PSHs as part of the energy transition to decarbonize energy sources. A comparison was made between PSHs and battery energy storage systems (BESSs) in terms of technical, economic, and ecological aspects. To identify the key factors influencing the wider adoption of PSHs, a combined approach using SWOT analysis (which assesses strengths, weaknesses, opportunities, and threats) and the Analytical Hierarchy Process (AHP) as a decision support tool was applied. Regulatory and market uncertainties (13.54%) and financial inequality (12.77%) rank first and belong to the “Threats” group, with energy storage capacity (10.11%) as the most important factor from the “Strengths” group and increased demand for energy storage (9.01%) as the most important factor from the “Opportunities” group. Forecasts up to 2050 show that the capacity of PSHs must be doubled to enable the integration of 80% of VRES into the grids. The study concludes that PSHs play a key role in the energy transition, especially for long-term energy storage and grid stabilization, while BESSs offer complementary benefits for short-term storage and fast frequency regulation. Recommendations to policymakers include the development of clear, accelerated project approval procedures, financial incentives, and support for hybrid PSH systems to accelerate the energy transition and meet decarbonization targets. Full article

(This article belongs to the Special Issue Innovative Power System Technologies)

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19 pages, 1768 KiB

Open AccessArticle

Innovative Investigation of the Influence of a Variable Load on Unbalance Fault Diagnosis Technologies

by Amir R. Askari, Len Gelman, Daryl Hickey, Russell King, Mehdi Behzad and Panchanand Jha

Technologies 2025, 13(7), 304; https://doi.org/10.3390/technologies13070304 - 15 Jul 2025

Abstract

This paper focuses on the influence of torsional loading on the vibration-based unbalance fault diagnosis technology under variable-speed conditions. The coupled flexural–torsional nonstationary governing equations of motion are obtained and solved numerically. Taking the short-time chirp Fourier transform from the acceleration signal, which [...] Read more.

This paper focuses on the influence of torsional loading on the vibration-based unbalance fault diagnosis technology under variable-speed conditions. The coupled flexural–torsional nonstationary governing equations of motion are obtained and solved numerically. Taking the short-time chirp Fourier transform from the acceleration signal, which is determined from the numerical solutions, the influence of variable loading on the magnitude of the fundamental rotational harmonic—a diagnostic feature for conventional unbalance diagnosis technology—as well as its speed-invariant version for novel unbalance diagnosis technology is assessed. Numerical assessment shows that despite the stationary conditions, where the first rotational harmonic magnitude is independent from the torsional load, the conventional unbalance technology depends on the variable torsional load. However, the novel speed-invariant diagnostic technology is independent of the variable torsional load. The dependency of the conventional unbalance fault diagnosis technology on the variable torsional load and the independency of the novel speed-invariant unbalance diagnostic technology on the variable loading are justified by performing thorough experimental investigations on a variable-speed wind turbine with a permissible level of unbalance. Full article

(This article belongs to the Special Issue Digital Data Processing Technologies: Trends and Innovations)

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20 pages, 4949 KiB

Open AccessArticle

Steam Distillation of Citrus Waste Extract for Antimicrobial Metal Nanoparticle Synthesis

by Javier Emanuel Castañeda-Aude, Enrique Díaz Barriga-Castro, Lizbeth Liliana Díaz-Muñoz, Javier Alberto Garza-Cervantes, José Rodríguez-Mirasol, José Rubén Morones-Ramírez, Héctor Javier Amézquita-García, David Alejandro De Haro-Del Río, Angel León-Buitimea, Noe Macias-Segura and Carlos Enrique Escárcega-González

Technologies 2025, 13(7), 303; https://doi.org/10.3390/technologies13070303 - 14 Jul 2025

Abstract

This research presents a novel, sustainable, and eco-friendly method for the rapid green synthesis of nanoparticles with antibacterial properties. This method employs steam distillation to extract reducing and stabilizing agents from orange peel waste, followed by ultrasound-assisted synthesis. To the best of our [...] Read more.

This research presents a novel, sustainable, and eco-friendly method for the rapid green synthesis of nanoparticles with antibacterial properties. This method employs steam distillation to extract reducing and stabilizing agents from orange peel waste, followed by ultrasound-assisted synthesis. To the best of our knowledge, this is the first reported integration of these two techniques for nanoparticle production. The extracted materials were then subjected to rigorous characterization through a combination of analytical techniques, including FTIR, HPLC, and TEM. These analytical approaches enabled a comprehensive analysis of the synthesized NPs, revealing their size distribution within the range of 1.5 to 14 nm. Among the synthesized nanomaterials, AgNPs exhibited the most potent antibacterial activity, with statistically significant minimum inhibitory concentrations (MICs) of 16 ppm for E. coli ATCC and 32 ppm for resistant E. coli and E. faecalis strains. This study underscored the promise of valorizing citrus waste for nanomaterial synthesis and introduced a novel, scalable methodology for producing bioactive nanoparticles, promoting a more sustainable technology for this purpose. Notably, this research aligns with United Nations Sustainable Development Goal 12, which promotes responsible consumption and production by transforming organic waste into high-value functional nanomaterials for biomedical and environmental applications. Full article

(This article belongs to the Section Environmental Technology)

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22 pages, 1703 KiB

Open AccessArticle

Developing a Concept for an OPC UA Standard to Improve Interoperability in Battery Cell Production: A Methodological Approach for Standardization in Heterogeneous Production Environments

by Julia Sawodny, Simon Otte, Fabian Böttinger, Fabian Haag, Andreas Schlereth, Tom-Hendrik Hülsmann, Felix Tidde, David Roth, Arno Schmetz, Alexander Puchta, Sebastian Schabel, Thomas Bauernhansl and Jürgen Fleischer

Technologies 2025, 13(7), 302; https://doi.org/10.3390/technologies13070302 - 14 Jul 2025

Abstract

The development of interoperable and reusable information models is a key challenge for digitalization in manufacturing domains with heterogeneous and complex process chains. Ensuring seamless data exchange requires the standardization of both data syntax and semantics, while maintaining compatibility with existing industry standards. [...] Read more.

The development of interoperable and reusable information models is a key challenge for digitalization in manufacturing domains with heterogeneous and complex process chains. Ensuring seamless data exchange requires the standardization of both data syntax and semantics, while maintaining compatibility with existing industry standards. This paper presents a methodology for deriving standardizable and generalizable OPC UA information models tailored to domains with high process variability and interdisciplinary requirements. The methodology integrates system analysis, parameter mapping, and the development of modular submodels, supported by expert input and validation. It emphasizes the reuse and extension of existing OPC UA Companion Specifications to reduce complexity, avoid redundancy, and enable long-term standardization. The approach is exemplified by its application to battery cell production, an emerging manufacturing domain combining process and mechanical engineering with continuous and discrete processes. Its high degree of heterogeneity and lack of domain-specific standards pose significant challenges for model development. Through iterative expert workshops and structured model validation, a dedicated and transferable OPC UA framework is created. The resulting layered model structure combines a cross-industry standard with newly developed, process-aware model elements. This enables both broad applicability and the depth required for complex production environments, while supporting use cases such as traceability, regulatory reporting (e.g., EU Battery Passport), and process optimization. The resulting model improves interoperability, transparency, and data integration, offering a scalable blueprint for other complex manufacturing sectors. Full article

(This article belongs to the Section Information and Communication Technologies)

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19 pages, 13921 KiB

Open AccessArticle

Improving CMTS Physical Properties Through Potassium Doping for Enhanced Rhodamine B Degradation

by Amira Bouali, Olfa Kamoun, Moez Hajji, Ileana Nicoleta Popescu, Ruxandra Vidu and Najoua Turki Kamoun

Technologies 2025, 13(7), 301; https://doi.org/10.3390/technologies13070301 - 12 Jul 2025

Abstract

This study investigated the enhancement of Cu₂MnSnS₄ (CMTS) thin films’ photocatalytic properties through potassium (K) doping for rhodamine B degradation under visible light. K-doped CMTS films synthesized using spray pyrolysis technology achieved a 98% degradation efficiency within 120 min. The [...] Read more.

This study investigated the enhancement of Cu₂MnSnS₄ (CMTS) thin films’ photocatalytic properties through potassium (K) doping for rhodamine B degradation under visible light. K-doped CMTS films synthesized using spray pyrolysis technology achieved a 98% degradation efficiency within 120 min. The physical property improvements were quantitatively validated through X-ray diffraction (XRD) analysis, which confirmed enhanced crystallinity. Scanning electron microscopy (SEM) revealed significant modifications in surface morphology as a function of potassium content, highlighting its influence on film growth dynamics. Optical characterization demonstrated a pronounced reduction in transmittance, approaching negligible values at 7.5% potassium doping, and a narrowed optical band gap of 1.41 eV, suggesting superior light absorption capabilities. Photocatalytic performance was significantly enhanced, achieving a Rhodamine B degradation efficiency of up to 98% at 7.5% doping. These enhancements collectively improved the material’s light-harvesting capabilities and charge separation efficiency, positioning K-doped CMTS as a highly effective photocatalyst compared to other ternary and quaternary materials. Full article

(This article belongs to the Special Issue Sustainable Water and Environmental Technologies of Global Relevance)

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27 pages, 1889 KiB

Open AccessArticle

Advancing Smart City Sustainability Through Artificial Intelligence, Digital Twin and Blockchain Solutions

by Ivica Lukić, Mirko Köhler, Zdravko Krpić and Miljenko Švarcmajer

Technologies 2025, 13(7), 300; https://doi.org/10.3390/technologies13070300 - 11 Jul 2025

Abstract

This paper presents an integrated Smart City platform that combines digital twin technology, advanced machine learning, and a private blockchain network to enhance data-driven decision making and operational efficiency in both public enterprises and small and medium-sized enterprises (SMEs). The proposed cloud-based business [...] Read more.

This paper presents an integrated Smart City platform that combines digital twin technology, advanced machine learning, and a private blockchain network to enhance data-driven decision making and operational efficiency in both public enterprises and small and medium-sized enterprises (SMEs). The proposed cloud-based business intelligence model automates Extract, Transform, Load (ETL) processes, enables real-time analytics, and secures data integrity and transparency through blockchain-enabled audit trails. By implementing the proposed solution, Smart City and public service providers can significantly improve operational efficiency, including a 15% reduction in costs and a 12% decrease in fuel consumption for waste management, as well as increased citizen engagement and transparency in Smart City governance. The digital twin component facilitated scenario simulations and proactive resource management, while the participatory governance module empowered citizens through transparent, immutable records of proposals and voting. This study also discusses technical, organizational, and regulatory challenges, such as data integration, scalability, and privacy compliance. The results indicate that the proposed approach offers a scalable and sustainable model for Smart City transformation, fostering citizen trust, regulatory compliance, and measurable environmental and social benefits. Full article

(This article belongs to the Section Information and Communication Technologies)

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29 pages, 1341 KiB

Open AccessArticle

GaN Power Amplifier with DPD for Enhanced Spectral Integrity in 2.3–2.5 GHz Wireless Systems

by Mfonobong Uko

Technologies 2025, 13(7), 299; https://doi.org/10.3390/technologies13070299 - 11 Jul 2025

Abstract

The increasing need for high-data-rate wireless applications in 5G and IoT networks requires sophisticated power amplifier (PA) designs in the sub-6 GHz spectrum. This work introduces a high-efficiency Gallium Nitride (GaN)-based power amplifier optimized for the 2.3–2.5 GHz frequency band, using digital pre-distortion [...] Read more.

The increasing need for high-data-rate wireless applications in 5G and IoT networks requires sophisticated power amplifier (PA) designs in the sub-6 GHz spectrum. This work introduces a high-efficiency Gallium Nitride (GaN)-based power amplifier optimized for the 2.3–2.5 GHz frequency band, using digital pre-distortion (DPD) to improve spectral fidelity and reduce distortion. The design employs load modulation and dynamic biasing to optimize power-added efficiency (PAE) and linearity. Simulation findings indicate a gain of 13 dB, a 3 dB compression point at 29.7 dBm input power, and 40 dBm output power, with a power-added efficiency of 60% and a drain efficiency of 65%. The power amplifier achieves a return loss of more than 15 dB throughout the frequency spectrum, ensuring robust impedance matching and consistent performance. Electromagnetic co-simulations confirm its stability under high-frequency settings, rendering it appropriate for next-generation high-efficiency wireless communication systems. Full article

(This article belongs to the Section Information and Communication Technologies)

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22 pages, 6525 KiB

Open AccessArticle

A Low-Cost Approach to Maze Solving with Image-Based Mapping

by Mihai-Sebastian Mănase and Eva-H. Dulf

Technologies 2025, 13(7), 298; https://doi.org/10.3390/technologies13070298 - 11 Jul 2025

Abstract

This paper proposes a method for solving mazes, with a special focus on navigation using image processing. The objective of this study is to demonstrate that a robot can successfully navigate a maze using only two-wheel encoders, enabled by appropriate control strategies. This [...] Read more.

This paper proposes a method for solving mazes, with a special focus on navigation using image processing. The objective of this study is to demonstrate that a robot can successfully navigate a maze using only two-wheel encoders, enabled by appropriate control strategies. This method significantly simplifies the structure of mobile robots, which typically suffer from increased energy consumption due to the need to carry onboard sensors and power supplies. Through experimental analysis, it was observed that although the encoder-only solution requires more advanced control knowledge, it can be more efficient than the alternative approach that combines encoders with a gyroscope. In order to develop an efficient maze-solving system, control theory techniques were integrated with image processing and neural networks in order to analyze images in which various obstacles were transformed into maze walls. This approach led to the training of a neural network designed to detect key points within the maze. Full article

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13 pages, 1574 KiB

Open AccessArticle

SnapStick: Merging AI and Accessibility to Enhance Navigation for Blind Users

by Shehzaib Shafique, Gian Luca Bailo, Silvia Zanchi, Mattia Barbieri, Walter Setti, Giulio Sciortino, Carlos Beltran, Alice De Luca, Alessio Del Bue and Monica Gori

Technologies 2025, 13(7), 297; https://doi.org/10.3390/technologies13070297 - 11 Jul 2025

Abstract

Navigational aids play a vital role in enhancing the mobility and independence of blind and visually impaired (VI) individuals. However, existing solutions often present challenges related to discomfort, complexity, and limited ability to provide detailed environmental awareness. To address these limitations, we introduce [...] Read more.

Navigational aids play a vital role in enhancing the mobility and independence of blind and visually impaired (VI) individuals. However, existing solutions often present challenges related to discomfort, complexity, and limited ability to provide detailed environmental awareness. To address these limitations, we introduce SnapStick, an innovative assistive technology designed to improve spatial perception and navigation. SnapStick integrates a Bluetooth-enabled smart cane, bone-conduction headphones, and a smartphone application powered by the Florence-2 Vision Language Model (VLM) to deliver real-time object recognition, text reading, bus route detection, and detailed scene descriptions. To assess the system’s effectiveness and user experience, eleven blind participants evaluated SnapStick, and usability was measured using the System Usability Scale (SUS). In addition to the 94% accuracy, the device received an SUS score of 84.7%, indicating high user satisfaction, ease of use, and comfort. Participants reported that SnapStick significantly improved their ability to navigate, recognize objects, identify text, and detect landmarks with greater confidence. The system’s ability to provide accurate and accessible auditory feedback proved essential for real-world applications, making it a practical and user-friendly solution. These findings highlight SnapStick’s potential to serve as an effective assistive device for blind individuals, enhancing autonomy, safety, and navigation capabilities in daily life. Future work will explore further refinements to optimize user experience and adaptability across different environments. Full article

(This article belongs to the Section Assistive Technologies)

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22 pages, 2221 KiB

Open AccessArticle

Enhanced Pedestrian Navigation with Wearable IMU: Forward–Backward Navigation and RTS Smoothing Techniques

by Yilei Shen, Yiqing Yao, Chenxi Yang and Xiang Xu

Technologies 2025, 13(7), 296; https://doi.org/10.3390/technologies13070296 - 9 Jul 2025

Abstract

Accurate and reliable pedestrian positioning service is essential for providing Indoor Location-Based Services (ILBSs). Zero-Velocity Update (ZUPT)-aided Strapdown Inertial Navigation System (SINS) based on foot-mounted wearable Inertial Measurement Units (IMUs) has shown great performance in pedestrian navigation systems. Though the velocity errors will [...] Read more.

Accurate and reliable pedestrian positioning service is essential for providing Indoor Location-Based Services (ILBSs). Zero-Velocity Update (ZUPT)-aided Strapdown Inertial Navigation System (SINS) based on foot-mounted wearable Inertial Measurement Units (IMUs) has shown great performance in pedestrian navigation systems. Though the velocity errors will be corrected once zero-velocity measurement is available, the navigation system errors accumulated during measurement outages are yet to be further optimized by utilizing historical data during both stance and swing phases of pedestrian gait. Thus, in this paper, a novel Forward–Backward navigation and Rauch–Tung–Striebel smoothing (FB-RTS) navigation scheme is proposed. First, to efficiently re-estimate past system state and reduce accumulated navigation error once zero-velocity measurement is available, both the forward and backward integration method and the corresponding error equations are constructed. Second, to further improve navigation accuracy and reliability by exploiting historical observation information, both backward and forward RTS algorithms are established, where the system model and observation model are built under the output correction mode. Finally, both navigation results are combined to achieve the final estimation of attitude and velocity, where the position is recalculated by the optimized data. Through simulation experiments and two sets of field tests, the FB-RTS algorithm demonstrated superior performance in reducing navigation errors and smoothing pedestrian trajectories compared to traditional ZUPT method and both the FB and the RTS method, whose advantage becomes more pronounced over longer navigation periods than the traditional methods, offering a robust solution for positioning applications in smart buildings, indoor wayfinding, and emergency response operations. Full article

(This article belongs to the Special Issue Wearable Vital Signs and Activities Detection: Systems and Applications)

24 pages, 7102 KiB

Open AccessArticle

Comparing a New Passive Lining Method for Jet Noise Reduction Using 3M™ Nextel™ Ceramic Fabrics Against Ejector Nozzles

by Alina Bogoi, Grigore Cican, Laurențiu Cristea, Daniel-Eugeniu Crunțeanu, Constantin Levențiu and Andrei-George Totu

Technologies 2025, 13(7), 295; https://doi.org/10.3390/technologies13070295 - 9 Jul 2025

Abstract

This study investigates the complementary noise control capabilities of two passive jet noise mitigation strategies: a traditional ejector nozzle and a novel application of 3M™ Nextel™ 312 ceramic fabric as a thermal–acoustic liner on the central cone of a micro turbojet nozzle. Three [...] Read more.

This study investigates the complementary noise control capabilities of two passive jet noise mitigation strategies: a traditional ejector nozzle and a novel application of 3M™ Nextel™ 312 ceramic fabric as a thermal–acoustic liner on the central cone of a micro turbojet nozzle. Three nozzle configurations, baseline, ejector, and Nextel-treated, were evaluated under realistic operating conditions using traditional and advanced acoustic diagnostics applied to data from a five-microphone circular array. The results show that while the ejector provides superior directional suppression and low-frequency redistribution, making it ideal for far-field noise control, it maintains high total energy levels and requires structural modifications. In contrast, the Nextel lining achieves comparable reductions in overall noise, especially in high-frequency ranges, while minimizing structural impact and promoting spatial energy dissipation. Analyses in both the time-frequency and spatial–spectral domains demonstrate that the Nextel configuration not only lowers acoustic energy but also disrupts coherent noise patterns, making it particularly effective for near-field protection in compact propulsion systems. A POD analysis further shows that NEXTEL more evenly distributes energy across mid-order modes, indicating its role in smoothing spatial variations and dampening localized acoustic concentrations. According to these results, ceramic fabric linings offer a lightweight, cost-effective solution for reducing the high noise levels typically associated with drones and UAVs powered by small turbojets. When combined with ejectors, they could enhance acoustic suppression in compact propulsion systems where space and weight are critical. Full article

(This article belongs to the Special Issue Aviation Science and Technology Applications)

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15 pages, 795 KiB

Open AccessArticle

Optimal Dispatch of Power Grids Considering Carbon Trading and Green Certificate Trading

by Xin Shen, Xuncheng Zhu, Yuan Yuan, Zhao Luo, Xiaoshun Zhang and Yuqin Liu

Technologies 2025, 13(7), 294; https://doi.org/10.3390/technologies13070294 - 9 Jul 2025

Abstract

In the context of the intensifying global climate crisis, the power industry, as a significant carbon emitter, urgently needs to promote low-carbon transformation using market mechanisms. In this paper, a multi-objective stochastic optimization scheduling framework for regional power grids integrating carbon trading (CET) [...] Read more.

In the context of the intensifying global climate crisis, the power industry, as a significant carbon emitter, urgently needs to promote low-carbon transformation using market mechanisms. In this paper, a multi-objective stochastic optimization scheduling framework for regional power grids integrating carbon trading (CET) and green certificate trading (GCT) is proposed to coordinate the conflict between economic benefits and environmental objectives. By building a deterministic optimization model, the goal of maximizing power generation profit and minimizing carbon emissions is combined in a weighted form, and the power balance, carbon quota constraint, and the proportion of renewable energy are introduced. To deal with the uncertainty of power demand, carbon baseline, and the green certificate ratio, Monte Carlo simulation was further used to generate random parameter scenarios, and the CPLEX solver was used to optimize scheduling schemes iteratively. The simulation results show that when the proportion of green certificates increases from 0.35 to 0.45, the proportion of renewable energy generation increases by 4%, the output of coal power decreases by 12–15%, and the carbon emission decreases by 3–4.5%. At the same time, the tightening of carbon quotas (coefficient increased from 0.78 to 0.84) promoted the output of gas units to increase by 70 MWh, verifying the synergistic emission reduction effect of the “total control + market incentive” policy. Economic–environmental tradeoff analysis shows that high-cost inputs are positively correlated with the proportion of renewable energy, and carbon emissions are significantly negatively correlated with the proportion of green certificates (correlation coefficient −0.79). This study emphasizes that dynamic adjustments of carbon quota and green certificate targets can avoid diminishing marginal emission reduction efficiency, while the independent carbon price mechanism needs to enhance its linkage with economic targets through policy design. This framework provides theoretical support and a practical path for decision-makers to design a flexible market mechanism and build a multi-energy complementary system of “coal power base load protection, gas peak regulation, and renewable energy supplement”. Full article

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23 pages, 16714 KiB

Open AccessArticle

A Dual-Stream Dental Panoramic X-Ray Image Segmentation Method Based on Transformer Heterogeneous Feature Complementation

by Tian Ma, Jiahui Li, Zhenrui Dang, Yawen Li and Yuancheng Li

Technologies 2025, 13(7), 293; https://doi.org/10.3390/technologies13070293 - 8 Jul 2025

Abstract

To address the widespread challenges of significant multi-category dental morphological variations and interference from overlapping anatomical structures in panoramic dental X-ray images, this paper proposes a dual-stream dental segmentation model based on Transformer heterogeneous feature complementarity. Firstly, we construct a parallel architecture comprising [...] Read more.

To address the widespread challenges of significant multi-category dental morphological variations and interference from overlapping anatomical structures in panoramic dental X-ray images, this paper proposes a dual-stream dental segmentation model based on Transformer heterogeneous feature complementarity. Firstly, we construct a parallel architecture comprising a Transformer semantic parsing branch and a Convolutional Neural Network (CNN) detail capturing pathway, achieving collaborative optimization of global context modeling and local feature extraction. Furthermore, a Pooling-Cooperative Convolutional Module was designed, which enhances the model’s capability in detail extraction and boundary localization through weighted centroid features of dental structures and a latent edge extraction module. Finally, a Semantic Transformation Module and Interactive Fusion Module are constructed. The Semantic Transformation Module converts geometric detail features extracted from the CNN branch into high-order semantic representations compatible with Transformer sequential processing paradigms, while the Interactive Fusion Module applies attention mechanisms to progressively fuse dual-stream features, thereby enhancing the model’s capability in holistic dental feature extraction. Experimental results demonstrate that the proposed method achieves an IoU of 91.49% and a Dice coefficient of 94.54%, outperforming current segmentation methods across multiple evaluation metrics. Full article

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30 pages, 7353 KiB

Open AccessReview

A Review of Assistive Devices in Synovial Joints: Records, Trends, and Classifications

by Filiberto Cruz-Flores, Ana L. Sánchez-Brito, Rafael Campos Amezcua, Agustín Barrera Sánchez, Héctor R. Azcaray Rivera, Arturo J. Martínez Mata and Andrés Blanco Ortega

Technologies 2025, 13(7), 292; https://doi.org/10.3390/technologies13070292 - 8 Jul 2025

Abstract

This article presents a comprehensive review of assistive devices for synovial joints, addressing their definitions, classifications, and technological advancements. The historical evolution of artificial exoskeletons, orthoses, prostheses, and splints is analyzed, emphasizing their impact on rehabilitation and the enhancement of human mobility. Through [...] Read more.

This article presents a comprehensive review of assistive devices for synovial joints, addressing their definitions, classifications, and technological advancements. The historical evolution of artificial exoskeletons, orthoses, prostheses, and splints is analyzed, emphasizing their impact on rehabilitation and the enhancement of human mobility. Through a systematic compilation of scientific literature, patents, and medical regulations, the study clarifies terminology and classifications that have often been imprecisely used in scientific discourse. The review examines the biomechanical principles of the musculoskeletal system and the kinematics of synovial joints, providing a reference framework for the optimization and design of these devices. Furthermore, it explores the various types of artificial exoskeletons, and their classification based on structure, mobility, power source, and control system, as well as their applications in medical, industrial, and military domains. Finally, this study highlights the necessity of a systematic approach in the design and categorization of these technologies to facilitate their development, comparison, and effective implementation, ultimately improving users’ quality of life. Full article

(This article belongs to the Special Issue Assistive Technologies in Care and Rehabilitation: Research, Developments, and International Initiatives)

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26 pages, 1976 KiB

Open AccessReview

Challenges in the Development of Exoskeletons for People with Disabilities

by Omar Flor-Unda, Rafael Arcos-Reina, Carlos Toapanta, Freddy Villao, Angélica Bustos-Estrella, Carlos Suntaxi and Héctor Palacios-Cabrera

Technologies 2025, 13(7), 291; https://doi.org/10.3390/technologies13070291 - 8 Jul 2025

Abstract

The development of exoskeletons aimed at enhancing the mobility and autonomy of people with disabilities marks a significant advance toward social and occupational inclusion, fostering greater independence and improved quality of life. However, their implementation poses multidisciplinary challenges, including technical issues, usability, cost, [...] Read more.

The development of exoskeletons aimed at enhancing the mobility and autonomy of people with disabilities marks a significant advance toward social and occupational inclusion, fostering greater independence and improved quality of life. However, their implementation poses multidisciplinary challenges, including technical issues, usability, cost, and user acceptance. This article synthesizes the main challenges, recent advancements, and future perspectives identified in scientific literature through a systematic review conducted under the PRISMA^® methodology. Forty-three high-impact publications indexed in SCOPUS, Web of Science, ScienceDirect, Taylor & Francis, IEEE Xplore, and PubMed were analyzed, showing an almost perfect inter-rater agreement (Cohen’s Kappa = 0.8390). The findings underscore the need to optimize control systems, reduce costs, and improve device adaptability. Artificial intelligence emerges as a key enabler to overcome these limitations, offering more efficient, affordable, and personalized solutions. This work provides an up-to-date overview of the field and outlines future directions for exoskeleton research and development, highlighting their transformative potential in the lives of people with disabilities. Full article

(This article belongs to the Section Assistive Technologies)

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2 pages, 140 KiB

Open AccessEditorial

Technologies—Aims and Scope Update

by Manoj Gupta

Technologies 2025, 13(7), 290; https://doi.org/10.3390/technologies13070290 - 8 Jul 2025

Abstract

The journal Technologies (ISSN 2227-7080) was launched in 2013 [...] Full article

20 pages, 2198 KiB

Open AccessArticle

Ellipsoidal-Set Design of Robust and Secure Control Against Denial-of-Service Cyber Attacks in Electric-Vehicle Induction Motor Drives

by Ehab H. E. Bayoumi, Hisham M. Soliman and Sangkeum Lee

Technologies 2025, 13(7), 289; https://doi.org/10.3390/technologies13070289 - 7 Jul 2025

Abstract

Electric vehicles face increasing cybersecurity threats that can compromise the integrity of their electric drive systems, especially under Denial-of-Service (DoS) attacks. To precisely regulate torque and speed in electric vehicles, vector-controlled induction motor drives rely on continuous communication between controllers and sensors. This [...] Read more.

Electric vehicles face increasing cybersecurity threats that can compromise the integrity of their electric drive systems, especially under Denial-of-Service (DoS) attacks. To precisely regulate torque and speed in electric vehicles, vector-controlled induction motor drives rely on continuous communication between controllers and sensors. This flow could be broken by a DoS attack, which could result in unstable motor operation or complete drive system failure. To address this, we propose a novel ellipsoidal-set-based state feedback controller with integral action, formulated via linear matrix inequalities (LMIs). This controller improves disturbance rejection, maintains system stability under DoS-induced input disruptions, and enhances security by constraining the system response within a bounded invariant set. The proposed tracker has a faster dynamic reaction and better disturbance attenuation capabilities than the traditional H_ꚙ control method. The effectiveness of the proposed controller is validated through a series of diverse testing scenarios. Full article

(This article belongs to the Special Issue Smart Transportation and Driving)

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