Zaid Allal, Hassan N. Noura, Flavien Vernier
et al.
Accurate prediction of the Remaining Useful Life (RUL) of fuel cell (FC) systems is essential to ensure operational reliability, optimize maintenance strategies, and extend system lifetime in safety-critical hydrogen applications. As FC degradation is governed by complex, nonlinear, and stochastic mechanisms, machine learning (ML) has emerged as a powerful paradigm for data-driven prognostics. This paper presents a structured and comprehensive review of recent ML-based approaches for FC RUL estimation, encompassing supervised, unsupervised, and hybrid methodologies, including regression techniques, support vector machines, ensemble models, neural networks, and advanced deep learning architectures. Despite notable progress, our analysis reveals persistent limitations in the current literature, particularly the widespread neglect of underlying electrochemical and physical degradation laws, as well as the scarcity and ambiguity of explicit RUL and End-of-Life (EoL) labels in publicly available datasets. These challenges significantly constrain model generalization, interpretability, and real-world applicability. To address these gaps, we conduct a comparative analysis of more than 20 recent state-of-the-art studies and propose a unified and generalizable RUL estimation pipeline. This framework integrates data acquisition, preprocessing, feature engineering, model design, and validation, while explicitly accounting for physical consistency and operational constraints. In addition, the paper formulates practical, multi-level recommendations, including first-order guidelines for data modeling and learning strategies, second-order recommendations targeting validation protocols and real-world deployment, and the systematic integration of uncertainty quantification (UQ) techniques to enhance robustness, interpretability, and trustworthiness. By consolidating methodological insights, emerging paradigms, and deployment-oriented considerations, this review provides a comprehensive reference and a forward-looking roadmap for the development of reliable, physics-consistent, and scalable RUL prognostic frameworks for fuel cell systems.
To solve the problem of lack of science and poor reusability of experience in traditional engineering scheme decision-making, which leads to the increase of time and cost of pre-decision-making, the study first uses case-based reasoning and ontology to construct a solution library for engineering solution decision-making system, and standardizes the cases using methods such as eigenfrequency. In addition, a retrieval mechanism based on residual similarity is designed to achieve effective retrieval of similar cases. The experiment outcomes denoted that the resource utilization rate of the traditional scheme was 75% before implementation, but decreased to 72% after implementation, a decrease of 3%. The resource utilization rate of the decision-making system scheme was 75% before implementation, and increased to 80% after implementation, an increase of 5%. The results indicated that the decision system scheme designed by the research performed better in terms of resource utilization, could more efficiently utilize resources, and reduce waste. The average decision accuracy of integrating CBR and BIM systems was 92%, significantly higher than the 84% of traditional decision systems. The CBR technology improved the scientificity and reliability of decision-making through continuous updating and optimization of the case library.
Various mechanisms have been investigated in the literature for seismic protection of fluid tanks. These structures play a pivotal role in the integrity, reliability, and safety of strategic industries. Any damage to fluid tanks can jeopardise these industries and the environment. In this research, a Smart Vertical Isolation System using magnetorheological dampers for rocking isolation of legged rigid cylindrical fluid tanks under base excitations has been proposed and investigated. First, dynamic equations of motion for the rocking rigid fluid tank are developed. Different semi-active classical and an online data-driven adaptive control technique are then employed to examine the efficacy of the rocking isolation system. Parameters of the data-driven controller are estimated online in real-time using the Recursive Least Squares approach, which offers simplicity, robustness against faults, and small memory requirements. Numerical simulations are compared with experimental investigations to validate the accuracy of the developed dynamic equations and the performance of the MR dampers and control techniques in mitigating the seismic effects on the examined fluid tank. The MR dampers and semi-active control strategies proved substantial reductions in the uplift displacement of the tank as one of the main causes of damage to these structures under earthquakes.
Production of electric energy or power. Powerplants. Central stations
Salim Hussain, Adeniyi Oyebade, Md Riyad Hossain
et al.
The demand for effective, economical, and sustainable anode materials for metal-ion batteries (MIBs) has increased significantly due to the rapid growth of energy storage technologies. Among various candidates, carbon-based materials have emerged as highly promising due to their abundance, structural versatility, and favorable electrochemical properties. This review highlights the current status and future directions of carbon-based anode materials in MIBs, with a particular focus on graphite, hard carbon, carbon nanotubes, heteroatom-doped carbons, carbon-based composites, and other related structures. Various synthesis strategies for these materials are presented, along with discussions on their physicochemical characteristics, including structural features that influence electrochemical performance. Furthermore, we provided an overview on the performance of newly developed carbon-based anode materials in lithium-, sodium-, potassium-, and other emerging metal-ion battery systems to assess the impact of different synthesis approaches. Special attention is given to surface engineering, heteroatom doping, and composite design that can address intrinsic challenges such as limited ion diffusion, low reversible capacity, and poor cycling stability in MIBs. This review does not cover any carbon materials which have been used as an additive. In addition, the review explores emerging opportunities enabled by advanced characterization techniques, computational modeling, and artificial intelligence for optimizing the design of next-generation carbon anode. Finally, this article provides future perspectives and insights into the design principles of novel carbon-based anode materials that can accelerate the development of high-performance, durable, and sustainable MIB technologies.
Production of electric energy or power. Powerplants. Central stations, Industrial electrochemistry
سید مصطفی نصرت آبادی, علی پیوند, مرتضی جدیدالاسلام
امروزه با توجه به نگرانی آلودگی و گازهای گلخانه ای، تولید یک انرژی پاک و استفاده از انرژیهای تجدیدپذیر به بهترین نحو (با بازدهی بالا) مسئله بسیار مهمیاست. اگر چه همیشه اهداف اقتصادی از اهداف زیست محیطی بیشتر مورد توجه قرار گرفته است، اما در این مقاله، در برنامهریزی بهینه پیشنهادی سیستم در شبکه میکروانرژی ملاحظات بیشتری به منظور در نظرگیری مسئله زیست محیطی صورت گرفته است. این سیستم بهینه، سیستم هاب انرژی را که بخش اصلی شبکه میکروانرژی است، به صورت شبکه مبتنی بر CCHP که با انرژیهای تجدیدپذیر ترکیب شده است، مورد مطالعه قرار میدهد. این سیستم از سه هاب انرژی و دستگاههای ذخیره ساز و مبدل انرژی استفاده میکند. از این رو در این مقاله، یک چارچوب برنامهریزی چندمرحلهای برای سیستم هاب انرژی و برای بهینه کردن عملکرد آن شامل کاهش آلودگی و هزینه عملیاتی پیشنهاد شده است. در این مدل برای توان تولیدی توسط منابع انرژی تجدیدپذیر حدود بالا و پایین در نظر گرفته شده است تا بیانگر احتمال انقطاع توان به دلیل نوسانات آنها باشد. همچنین، با در نظر گرفتن چندین تابع هدف میتوان شرایط تصمیم گیری بهینه را برای اپراتور تصمیم گیرنده تضمین کرد. برای حل مسئله چند هدفه در این مقاله از روش اپسیلون پیشرفته استفاده شده است. علاوه برآن در این مقاله دو روش تصمیم گیری بهینه پیشنهاد و با یکدیگر مقایسه شده اند. نتایج بدست آمده پس از اجرای مدل پیشنهادی نشان دهنده کارایی مدل در کاهش هزینه و آلودگی زیست محیطی می باشد.
The emergence of millimeter-wave-based 5G/Beyond 5G and 6G communication technologies has led to advancements in high data rates and low latency. However, there is a massive challenge in implementing the hardware platform including the millimeter-wave antenna. Over-the-air (OTA) testing is crucial for evaluating these antennas, often requiring large facilities to obtain far-field (FF) characteristics. In addition, the measurement accuracy is often limited mainly due to the path loss of the millimeter waves in the far field. Therefore, it is necessary to test the antenna in the near-field (NF) region. In this paper, we present a practical method for obtaining an FF pattern of the antenna-under-test by using an NF-to-FF transformation method with a probe correction technique. The feasibility of the process is validated by the OTA measurement results with a dedicated NF scanning system, which accurately reconstructs the FF patterns from the NF measurement results. A key contribution of this paper is the successful demonstration of a planar multi-patch antenna as an effective multi-probe for NF measurements, enabling a significant reduction in measurement time while maintaining high reconstruction accuracy. Its compact and planar form factor facilitates easy integration into space-constrained measurement setups, making it particularly suitable for automatic test equipment (ATE) and scalable testing systems.
The aim of this study was to determine the frequency of body shapes of the studied group of women using different body shape classification methods. The objective was to investigate the fit of clothing for the average body shapes identified. Forty female participants from Slovenia, aged 20–30, were included in the analysis. Body shapes were classified using three methods: Visual assessment of body shape (VABS), female figure identification technique (FFIT), and body shape classification method (BSCM). For each classification method, ANOVA tests were performed to determine whether there were statistically significant differences in body measurements across the identified body shapes. A comparison of body shapes was carried out and also visualised by simulating 3D body shapes. The fit of clothing to body shapes was analysed with the help of virtual 3D prototyping. Four characteristic body shapes have been identified, namely triangle (pear, spoon), hourglass, rectangle and inverted triangle. The VABS method differs slightly from the other two (FFIT, BSCM), which give very similar results. When applying the FFIT and BSCM, the triangle body shape is the most representative, followed by the hourglass shape, the rectangle and the inverted triangle shape. Simulating the fit of the basic dress pattern design on 3D body shapes using the best match of dress size shows that the dress fits the hourglass shape best, while the fit for the other three shapes is inadequate. The latter indicates the need to make most of the garments for the triangle body shape and a corresponding number of garments for the hourglass and rectangle body shapes to ensure the correct fit of the garments.
Due to their unique bistable characteristics, deployable self-locking structures are suitable for many engineering fields. Without changing the geometrical composition, such structures can be unfolded and locked solely by the elastic deformation of materials. However, their further applications are hampered by the lack of simple and systematic geometric design methodologies that consider arbitrary structural curvature profiles. This paper proposes such a methodology for double-layer semicylindrical grid structures to simplify their cumbersome geometric design. The proposed methodology takes joint sizes into account to ensure that the design results can be applied to actual projects without further adjustments. By introducing symmetry into the structural units (SUs) and selecting reasonable geometric parameters that describe the structural side elevation profile, a concise set of simultaneous nonlinear geometric constraint equations is established, the solution of which provides the geometric parameter values of the grid shape. On this basis, the remaining geometric parameter values, i.e., the geometric parameter values of the inner scissor-like elements (SLEs) of each SU, can be achieved from the equations derived from general SLEs. Design examples and the assembled physical grid structure indicate the feasibility and wide applicability of the proposed geometric design methodology.
Sex determination in chickens at an early embryonic stage has been a longstanding challenge in poultry production due to the unique ZZ:ZW sex chromosome system and various influencing factors. This review has summarized the genes related to the sex differentiation of chicken early embryos (mainly Dmrt1, Sox9, Amh, Cyp19a1, Foxl2, Tle4z1, Jun, Hintw, Ube2i, Spin1z, Hmgcs1, Foxd1, Tox3, Ddx4, cHemgn and Serpinb11 in this article), and has found that these contributions enhance our understanding of the genetic basis of sex determination in chickens, while identifying potential gene targets for future research. This knowledge may inform and guide the development of sex screening technologies for hatching eggs and support advancements in gene-editing approaches for chicken embryos. Moreover, these insights offer hope for enhancing animal welfare and promoting conservation efforts in poultry production.
The agile earth observation satellite scheduling problem (AEOSSP) is a combinatorial optimization problem with time-dependent constraints. Recently, many construction heuristics and meta-heuristics have been proposed; however, existing methods cannot balance the requirements of efficiency and timeliness. In this paper, we propose a graph attention network-based decision neural network (GDNN) to solve the AEOSSP. Specifically, we first represent the task and time-dependent attitude transition constraints by a graph. We then describe the problem as a Markov decision process and perform feature engineering. On this basis, we design a GDNN to guide the construction of the solution sequence and train it with proximal policy optimization (PPO). Experimental results show that the proposed method outperforms construction heuristics at scheduling profit by at least 45%. The proposed method can also calculate the approximate profits of the state-of-the-art method with an error of less than 7% and reduce scheduling time markedly. Finally, we demonstrate the scalability of the proposed method.
In order to compare and investigate the sulfuric acid corrosion resistance of concrete for PHC pipe piles and two kinds of concrete commonly used in engineering, acid accelerated corrosion tests were conducted on specimens with three different strength grades of C30, C50, and C80 in a sulfuric acid solution with pH ≈ 0.85. The appearance of the specimens was observed, and the changes in mass loss percentage, corrosion depth, and stress–stain curves under uniaxial compressive loading were calculated and obtained with the corrosion time. From the comparison of corrosion depth and mass loss percentage of the concrete specimens with three different strength grades of C30, C50, and C80, it was found that the higher the strength grade of the concrete, the more severe the corrosion degree. The shapes of the stress–strain curves of three different strength grades of concrete specimens were basically the same. As the corrosion time was prolonged, the peak stress and the elastic modulus of concrete decreased. From the perspective of long-term corrosion, C80 specimens had a relatively smaller percentage of peak stress loss and a stronger resistance to peak stress loss. The research results provide references for the durability design of concrete structures and the prediction of concrete’s service life in a sulfuric acid environment.
Kumar Kaushal, Dixit Saurav, Haq Md. Zia ul
et al.
The research investigates Functionally Graded Materials (FGMs) and their transformational potential in modern engineering. FGMs, which exhibit progressive property fluctuations, call into question traditional material consistency. This study analyses the growth of FGMs and their importance in solving complex engineering difficulties through historical analysis and real-world case studies. The research dives into the design concepts, material selection, manufacturing procedures, and sophisticated characterisation methodologies that underpin FGM development from a methodological standpoint. Mechanical, thermal, and electrical characteristics, in combination with microstructural progression, offer a thorough knowledge of FGM behaviour. The implications for future engineering advances are highlighted, with a focus on the ability to rethink material design and multifunctional performance. Among the many attractive possibilities, issues in scalability, characterisation, and multidisciplinary cooperation need additional investigation. FGMs represent a paradigm shift from homogeneity to targeted heterogeneity, echoing wider shifts in engineering philosophy and influencing technological development.
Shalok Bharti, Sudhir Kumar, Inderjeet Singh
et al.
Friction stir welding (FSW) has been recognized as a revolutionary welding process for marine applications, effectively tackling the distinctive problems posed by maritime settings. This review paper offers a comprehensive examination of the current advancements in FSW design, specifically within the marine industry. This paper provides an overview of the essential principles of FSW and its design, emphasizing its comparative advantages when compared with conventional welding techniques. The literature review reveals successful implementations in the field of shipbuilding and offshore constructions, highlighting design factors as notable enhancements in joint strength, resistance to corrosion, and fatigue performance. This study examines the progress made in the field of FSW equipment and procedures, with a specific focus on their application in naval construction. Additionally, it investigates the factors to be considered when selecting materials and ensuring their compatibility in this context. The analysis of microstructural and mechanical features of FSW joints is conducted, with a particular focus on examining the impact of welding settings. The study additionally explores techniques for mitigating corrosion and safeguarding surfaces in marine environments. The study also provides a forward-looking perspective by proposing potential areas of future research and highlighting the issues that may arise in the field of FSW for maritime engineering. The significance of incorporating environmental and economic considerations in the implementation of FSW for extensive marine projects is emphasized.
Matthias T. Agne, Thorben Böger, Tim Bernges
et al.
Battery technologies have evolved rapidly over the past decade, including the advent of solid-state batteries. In this time, it has become apparent that thermal management is paramount for device operation and lifetime. However, the fundamental importance of the thermal properties of materials, such as thermal conductivity, in engineering design and mitigating the risk of catastrophic failure is yet to be fully understood. This Perspective aims to provide motivation for the fields of thermal transport and ionic transport to join forces to understand heat transport for better battery design, especially in light of solid-state batteries. From the basic characterization of thermal conductivity in bulk materials to considering the full complexity of battery composites during electrochemical cycling, there are many potential directions for fundamental and applied investigations. We anticipate that studying heat transport in battery materials has the added benefit of extending the design space to other functional devices. The difficulty in controlling heat transport in solid-state energy devices, including microelectronics, batteries, and thermoelectrics, is often a limiting factor in improving device performance. Especially in batteries, not only can excessive heat cause degradation that leads to a loss of charge capacity over time, but thermal runaway can occur when the battery overheats to catastrophic failure. Thus, understanding heat evolution and thermal transport in batteries is an important step to improve lifetime and safety. It is from this perspective that we provide the motivation for the importance of bringing together the fields of thermal transport and battery research, particularly to study solid-state batteries, which epitomize the overall complexity of battery systems and require a state-of-the-art understanding of thermal transport mechanisms. Here, we identify the basic and applied scientific directions that may prove fruitful for the next generation of battery thermal management.
Production of electric energy or power. Powerplants. Central stations, Renewable energy sources
Goal of this research was to develop and manufacture planetary gearbox prototype using rapid prototyping technology (additive manufacturing). Developed prototype was used to visually analyse the design of the planetary gearbox. Also, it was used to improve and innovate education of students on several courses at Mechanical Design study program at Faculty of Mechanical Engineering. It is shown that low cost rapid prototyping technology can be used to manufacture prototypes of complex machines and machine elements. Prototypes manufactured using this technology have same functionality like the real one. Main limitation is the fact that they cannot sustain real world loads and stresses. This paper shows opportunities which low cost rapid prototyping technology is offering in improvement and innovation of education process at engineering schools and faculties. All complex and heavy machines can be manufactured using this type of technology and on that way more precisely presented to the students.
Teunis van Manen, Shahram Janbaz, Kaspar M. B. Jansen
et al.
Shape-shifting structures are important building blocks in the design of reconfigurable materials and devices with advanced functionalities. Here, versatile metamaterials with 3D-to-3D shape-shifting behavior upon thermal activation are fabricated by adapting a 3D printer to print on curved surfaces.
Materials of engineering and construction. Mechanics of materials