Search Results (50)

Today’s economic systems are characterized by overproduction, rapid changes in consumer preferences and the intensive exploitation of natural resources. For this reason, the idea of the circular economy has emerged in recent years as a key strategy for tackling environmental, social and resource problems. At the same time, manufacturers are increasingly trying to fulfill customer requirements, so that products are becoming ever more personalized. This increasing focus on individuality is leading to greater variability in design, while at the same time the complexity of product structures and components is increasing, which poses major challenges for production and assembly processes. Understanding this complexity helps in finding the most effective ways for the disassembly process to enable reuse, repair and high-quality recycling, which are among the key principles of the circular economy. This not only supports environmental and resource sustainability, but also contributes to long-term competitiveness and climate neutrality in manufacturing. This paper outlines how complexity is defined and how this parameter can be used to obtain an optimal solution for minimizing product complexity and maximizing the number of disassembled parts. This problem was modeled using linear programming, where the optimal disassembly sequence was defined taking into account variables and constraints such as the time available within a working day and the complexity of the sub-assemblies. The results showed that the process can be significantly optimized if clear variables and targets are defined. Full article

The Planet Optimization Algorithm (POA) is a meta-heuristic inspired by celestial mechanics, drawing on Newtonian gravitational principles to simulate planetary dynamics in optimization search spaces. While the POA demonstrates a strong performance in continuous domains, we propose an Improved Binary Planet Optimization Algorithm (IBPOA) tailored to the classical 0-1 knapsack problem (0-1 KP). Building upon the POA, the IBPOA introduces a novel improved transfer function (ITF) and a greedy repair operator (GRO). Unlike general binarization methods, the ITF integrates theoretical foundations from branch-and-bound (B&B) and reduction algorithms, reducing the search space while guaranteeing optimal solutions. This improvement is strengthened further through the incorporation of the GRO, which significantly improves the searching capability. Extensive computational experiments on large-scale instances demonstrate the IBPOA’s effectiveness for the 0-1 KP, showing a superior performance in its convergence rate, population diversity, and exploration–exploitation balance. The results from 30 independent runs confirm that the IBPOA consistently obtains the optimal solutions across all 15 benchmark instances, spanning three categories. Wilcoxon’s rank-sum tests against seven state-of-the-art algorithms reveal that the IBPOA significantly outperforms all competitors $(p<0.05)$, though it is occasionally matched in its solution quality by the binary reptile search algorithm (BinRSA). Crucially, the IBPOA achieves solutions 4.16 times faster than the BinRSA on average, establishing an optimal balance between solution quality and computational efficiency. Full article

Repairing veneer defects is the key to ensuring the quality of plywood. In order to improve the maintenance quality and material utilization efficiency during the maintenance process, this paper proposes a bidirectional maintenance method based on gear rack transmission and its related equipment. Based on the working principle, a geometric relationship model was established, which combines the structural parameters of the mold, punch, and gear system. Simultaneously, it solves the problem of motion attitude analysis of conjugate tooth profiles under non-standard meshing conditions, aiming to establish a constraint relationship between stamping motion and structural design parameters. On this basis, a constrained optimization model was developed by integrating multi-objective optimization theory to maximize maintenance efficiency. The NSGA-III algorithm is used to solve the model and obtain the Pareto front solution set. Subsequently, three optimal parameter configurations were selected for simulation analysis and experimental platform construction. The simulation and experimental results indicate that the veneer repair time ranges from 0.6 to 1.8 seconds, depending on the stamping speed. A reduction of 28 mm in die height decreases the repair time by approximately 0.1 seconds, resulting in an efficiency improvement of about 14%. The experimental results confirm the effectiveness of the proposed method in repairing veneer defects. Vibration measurements further verify the system’s stable operation under parametric modeling and optimization design. The main vibration response occurs during the meshing and disengagement phases between the gear and rack. Full article

The restoration of gold leaf on sandstone sculptures requires structural stability, aesthetic considerations, and compliance with the principles of cultural heritage preservation. A primary issue is achieving visual and material compatibility between newly restored and original areas. Based on the “Diagnosis–Analysis–Selection–Restoration” methodology, the research team developed a targeted restoration approach for gilded stone sculptures, using the Shakyamuni sculpture at Erfo Temple in Chongqing as a case study. Assessment of the current situation revealed that over 70% of the sculpture’s surface exhibited gold leaf delamination. The composition and structure of the gold-sizing lacquer, lacquer plaster filler, ground layers, and pigments were investigated using SEM-EDS, XRD, Raman spectroscopy, and THM-Py-GC/MS techniques. The results confirmed that the sculpture featured a typical multilayer gilding structure with clear evidence of historical restorations. Considering both material performance and interfacial compatibility, an NHL2/SiO₂/SF016 composite emulsion and traditional lacquer plaster were selected as the optimal materials for reattachment and infill, respectively. A scientific restoration protocol was developed, encompassing gentle cleaning, targeted reattachment and reinforcement, and region-specific repair methods. Principal Component Analysis (PCA) was used to evaluate the influence of temperature and humidity on the curing behavior of lacquer layers. Additionally, a non-invasive gold leaf color-matching technique was developed by controlling the surface roughness of the gold-sizing lacquer, effectively avoiding the damage caused by traditional color-matching methods. Full article

Seed germination, a pivotal stage in the plant life cycle, profoundly impacts crop growth and establishment. However, fluctuating environmental conditions like drought, salinity, severe temperatures, and heavy metal toxicity impede seed germination rates and seedling vigor. Seed priming is a pre-sowing seed treatment that involves the controlled hydration of seeds, proven to improve germination rate and stress resilience. It initiates pre-germinative metabolism, including enzyme activity, antioxidant accumulation, hormone modulation, and cellular repair, without radicle emergence. Recent advancements in seed priming, encompassing the application of nanoparticles, phytohormones, and beneficial microbes, have significantly broadened its potential. Despite its proven benefits, challenges such as reduced seed longevity post-priming and variability in species-specific responses remain. This paper revisits the principles and methodologies of seed priming, highlighting its physiological, biochemical, and molecular mechanisms that enhance germination under stress conditions. Additionally, it addresses current challenges and future research directions for optimizing seed priming as a low-cost, eco-friendly approach to improve crop establishment under adverse environments, thereby supporting resilient and sustainable agriculture. Full article

Concrete and other cementitious materials are among the most widely used construction materials worldwide. However, their high embodied carbon emissions and energy-intensive manufacturing processes pose significant environmental challenges. This study assesses the carbon emissions, cost implications, and circularity potential of a novel concrete mix, Tex-crete, which incorporates recycled textile and cardboard fibres as sustainable alternatives to conventional reinforcement and cementitious materials in concrete. The study employs a cradle-to-gate life cycle assessment (LCA) approach to compare carbon emissions and costs across different mix designs, using two case studies: a temporary construction site compound and a footpath. Experimental results indicate that Tex-crete, particularly the KFT mix design (including 2.5% textile fibres with treated kraft fibres), achieves comparable compressive and tensile strength to traditional concrete while demonstrating a net reduction in both carbon emissions (3.38%) and production costs (2.56%). A newly introduced circularity index (CI) further evaluated the reuse, repair, and recycling potential of the novel mix, revealing that KFT exhibits the highest circularity score (0.44). Parametric analysis using Monte Carlo simulations highlighted transportation distance and energy consumption during fibre processing as key factors influencing emissions. The findings provide valuable insights for industry stakeholders seeking sustainable concrete solutions aligned with circular economy principles, offering an optimized balance between environmental performance, structural integrity, and cost-effectiveness. Full article

Data waste presents a growing challenge in the digital era, characterized by redundant, outdated, and underutilized data that contributes to inefficiencies, increased costs, and environmental concerns. This paper explores how circular economy (CE) principles—reduce, reuse, recycle, repair, and rethink—can be adapted to optimize data usage, minimize waste, and ensure responsible data handling throughout its lifecycle. Applying CE concepts to data management can enhance sustainability, improve operational efficiency, and support responsible digital transformation. This study examines key strategies and challenges in implementing circular data management, emphasizing data reuse, lifecycle management, and policy frameworks. Furthermore, real-world examples and case studies demonstrate the impact of CE principles in reducing data waste and improving efficiency. Notably, AI-driven data minimization strategies have led to 30% reductions in storage costs, while centralized data-sharing initiatives have improved operational efficiency by 20%. These findings underscore the necessity of structured data governance in the digital economy. Full article

The escalating demands of industrial applications, particularly those involving severe wear, temperature, and corrosive environments, present significant challenges for the long-term strength of critical components, often fabricated from high-value materials such as super duplex stainless steel alloys. Super duplex can withstand the corrosive environment (in particular, crevice corrosion and pitting damage) and maintain mechanical integrity sufficient for high-pressure pumping applications such as seawater injection and crude oil. Conventional repair methodologies frequently result in component rejection due to process-induced distortions or detrimental phase transformations, contributing to substantial material waste and hindering the adoption of circular economy principles. This research addresses this issue by developing and validating a novel repair process utilizing laser metal deposition (LMD) additive manufacturing. The research focuses on establishing optimized process parameters to ensure the salvaging and restoration of damaged super duplex components while preserving their requisite mechanical integrity and corrosion resistance, in accordance with industry standards. Comprehensive characterization, including microstructural analysis, chemical composition verification, hardness profiling, and mechanical fatigue testing, confirms the efficacy of the LMD repair process. This work demonstrates the potential for extending the service life of critical components, thereby promoting resource efficiency and contributing to a more sustainable and resilient industrial paradigm. Full article

Periodization is a concept of systematic progression in training and rehabilitation. The rehabilitation literature, however, is scarce, with information about optimally designing resistance training programs based on periodization principles for injured athletes. This periodization model—reverse linear neuro periodization—is a model proposed for the long-term rehabilitation needed after an arthroscopic rotator cuff repair. With recent evidence supporting neural contributions to shoulder injuries and the rate of recovery, rehabilitation protocols may benefit from incorporating approaches that target the sensorimotor system. Integrating motor learning principles (external focus and differential learning) and new technologies (virtual reality, laser pointers, stroboscopic glasses) may bolster current shoulder rehabilitation protocols and improve patient recovery times and outcomes. Such an understanding allows well-informed sport rehabilitation specialists to better bridge the gap between the preparation for competition widely used by coaches and the treatment of injuries that may occur. Full article

The gradual deterioration of underground water infrastructure requires constant condition monitoring to prevent catastrophic failures, reduce leaks, and avoid costly unexpected repairs. However, given the large scale and tight budgets of water utilities, it is essential to implement strategies for optimal selection and deployment of monitoring technologies. This article introduces a unified framework and methods for optimally selecting condition monitoring technologies while locating their deployment at the most vulnerable pipe segments. The approach is underpinned by an R-E-R-A-V (Redundant, Established, Reliable, Accurate, and Viable) principle and asset management concepts. The proposed method is supported by a thorough review of assessment and monitoring technologies, as well as common sensor placement approaches. The approach selects optimal technology using a combination of technology readiness levels and SFAHP (Spherical Fuzzy Analytic Hierarchy Process). Optimal placement is achieved with a k-Nearest Neighbors (kNN) model tuned with minimal topological and physical pipeline system features. Feature engineering is performed with OPTICS (Ordering Points to Identify the Clustering Structure) by evaluating the pipe segment vulnerability to failure-prone areas. Both the optimal technology selection and placement methods are integrated through a proposed algorithm. The optimal placement of monitoring technology is demonstrated through a modified benchmark network (Net3). The results reveal an accurate model with robust performance and a harmonic mean of precision and recall of approximately 65%. The model effectively identifies pipe segments requiring monitoring to prevent failures over a period of 11 years. The benefits and areas of future exploratory research are explained to encourage improvements and additional applications. Full article

The swift global proliferation of solar photovoltaic (PV) technology has significantly contributed to the acceleration of the transition to renewable energy. Projections indicate a significant rise in installed capacity by 2050, suggesting that the extensive implementation of solar panels is transforming energy systems while simultaneously highlighting important issues regarding end-of-life waste management and long-term sustainability. The environmental advantages of photovoltaic (PV) systems are overshadowed by the prevalent reliance on landfilling and inadequate recycling practices, revealing a substantial deficiency in sustainable waste management, especially in areas with underdeveloped policy frameworks. This research study examines the solar panel supply chain, highlighting critical stages, sources of waste generation, existing management practices, and potential areas for enhancement. Waste is classified into four categories, solid, hazardous, electronic (WEEE), and environmental, each necessitating specific management strategies. Regions such as Europe exhibit comprehensive legal frameworks and advanced recycling technologies, whereas others, including Latin America and certain areas of Asia, continue to encounter deficits in policy and infrastructure. The research highlights the implementation of the 6R principles—Recycle, Recover, Reduce, Reuse, Repair, and Refine—within a circular economy framework to improve sustainability, optimize resource utilization, and reduce environmental impact. The findings highlight the necessity for coordinated policies, technological innovation, and international collaboration to ensure a sustainable future for solar energy. This study offers important insights for policymakers, industry stakeholders, and researchers focused on enhancing circularity and sustainability within the photovoltaic sector. Full article

Adhesive hydrogels with tunable mechanical properties and strong adhesion to wet, dynamic tissues have emerged as promising materials for tissue repair, with potential applications in wound closure, hemorrhage control, and surgical adhesives. This review highlights the key design principles, material classifications, and recent advances in adhesive hydrogels designed for vascular repair. The limitations of existing adhesive hydrogels, including insufficient mechanical durability, suboptimal biocompatibility, and challenges in targeted delivery, are critically evaluated. Furthermore, innovative strategies—such as incorporating self-healing capabilities, developing stimuli-responsive systems, integrating functional nanocomposites, and employing advanced fabrication techniques like 3D bioprinting—are discussed to enhance adhesion, mechanical stability, and vascular tissue regeneration. While significant progress has been made, further research and optimization are necessary to advance these materials toward clinical translation, offering a versatile and minimally invasive alternative to traditional vascular repair techniques. Full article

This study evaluates the integration of reused PV modules within an agrivoltaic system designed for sustainable horticultural production, focusing on energy performance and agricultural outcomes. The experimental setup included both new and partially repaired PV modules, installed over tomato crops under real operating conditions. The results demonstrate that reused PV modules exhibit a strong and consistent energy performance, achieving correlations between irradiance and energy output comparable to new panels. Despite slightly lower performance ratios, reused modules maintained stable efficiency and operational viability, emphasizing their potential for sustainable applications. On the agricultural side, shading provided by PV panels protects the crop yield. This study highlights the environmental and economic advantages of incorporating reused PV modules into agrivoltaic systems, including reductions in raw material extraction, electronic waste generation, and overall environmental impact. By leveraging the circular economy principles, agrivoltaics with reused PV modules provide a sustainable pathway to balance energy production and food security while optimizing land use efficiency. These findings establish the potential of agrivoltaics as a key technology in advancing the sustainable energy transition. Full article

Fetal surgery has made significant strides over the past 40 years, facilitated by advances in technology and imaging modalities enabling the diagnosis and treatment of congenital anomalies in utero. The Management of Myelomeningocele Study (MOMS), a multicenter randomized controlled trial, established open fetal myelomeningocele (MMC) repair as the gold standard for improving neurological outcomes compared to postnatal repair. However, this approach is associated with increased maternal complications and preterm birth due to hysterotomy, prompting the exploration of minimally invasive alternatives. Due to the lack of an existing randomized control trial with fetoscopic MMC repair and variations in technique (percutaneous versus laparotomy/transuterine access, different trocar configurations, closure methods, and patch applications) among different fetal centers, more studies are needed to optimize this approach as an alternative to the standard of care. This paper proposes to assess the basics tenets of open fetal MMC repair and to establish guiding principles for a fetoscopic approach that could prove to be equivalent or superior to open fetal MMC repair in maternal and fetal outcomes and lead to clinical implementation. Full article

The application of light-responsive nanomaterials (LRNs) in bone tissue engineering shows broad prospects, especially in promoting bone healing and regeneration. With a deeper understanding of the mechanisms of bone defects and healing disorders, LRNs are receiving increasing attention due to their non-invasive, controllable, and efficient properties. These materials can regulate cellular biological reactions and promote bone cell adhesion, proliferation, and differentiation by absorbing specific wavelengths of light and converting them into physical and chemical signals. In addition, the unique surface morphology and biocompatibility of LRNs enable them to effectively load drugs in bone tissue engineering, achieve precise release, and optimize the bone regeneration process. Through photothermal and photodynamic therapy, these materials also possess antibacterial properties and can play an important role in the repair of infectious bone defects. Although LRNs have shown significant advantages in bone tissue regeneration, a series of challenges still need to be overcome to achieve their widespread and effective clinical applications. This article summarizes the basic principles, classification, and potential applications of LRNs in bone tissue regeneration, aiming to provide reference for future research and clinical applications. Full article