Search Results (333)

Robotic pipe welding represents a key and rapidly evolving technology for the automation of pipe and pipe-joint welding processes with standard, intersecting, and complex geometries. This review analyses 84 studies published over the past three decades, categorising them into four primary research areas: general pipe welding, intersecting pipes, boiler and tube-to-tubesheet welding, and control and modelling. Two separate comparative analyses were conducted: one within intersecting pipe research and another within the control and modelling category. The aggregated findings reveal consistent, complementary patterns: simulation and laboratory experiments clearly dominate validation methods, while industrial-scale evaluations remain scarce. The results further demonstrate that control strategies, sensor integration, and validation levels are strongly interconnected, collectively determining system performance, reliability, and practical applicability. Despite significant progress, challenges remain, including system integration complexity, limited robustness in variable industrial environments, insufficient real-time adaptive control, and inconsistent quantitative performance evaluation. Further research should prioritise the development of digital twins, human–robot collaboration, multi-sensor fusion, reinforcement learning-based adaptive control, and scalable industrial deployment. This review provides an overview of current progress and outlines key directions for developing intelligent and reliable robotic pipe welding systems. Full article

Effective management of acute, complex, and chronic wounds requires constructs that simultaneously support tissue repair and provide sustained infection control. Biologic-derived materials, despite their regenerative potential, are limited by insufficient long-term antibacterial activity and susceptibility to enzymatic degradation. To overcome these limitations, a fully absorbable synthetic matrix composed of electrospun composite fibers functionalized with polyhexamethylene biguanide (PHMB) (hereafter, PHMB Matrix) was developed to mimic extracellular matrix architecture while enabling durable antibacterial performance. Quantitative assessment per AATCC 100 demonstrated robust broad-spectrum efficacy (>99.99% reduction) against six clinically relevant Gram-positive and Gram-negative pathogens, with potency retained after 15 months of real-time aging. The matrix’s interconnected fibrous architecture enables a controlled, biphasic PHMB release coordinated with biodegradation, sustaining antibacterial protection throughout a 28-day healing period. In porcine full-thickness wound models, the PHMB Matrix achieved 63.53% ± 12.0% wound area reduction by Day 22, demonstrating accelerated mid-phase healing compared to an antibacterial collagen control (p < 0.05 on Day 22), with both treatments achieving comparable near-complete closure by Day 28. Pharmacokinetic analysis confirmed localized drug enrichment with negligible systemic exposure. These findings establish the PHMB-functionalized synthetic matrix as a safe, effective, fully absorbable alternative to biologic-derived materials for soft tissue repair, offering sustained antibacterial efficacy and a favorable safety profile. Full article

Maintaining frequency stability in modern multi-area interconnected power systems has become increasingly challenging due to the stochastic nature of wind power and reduced effective system inertia. Under these dynamic conditions, traditional fixed-gain PID controllers frequently fail to provide robust regulation. To address this limitation, this study proposes and evaluates a practical model-free secondary control strategy for multi-area Load Frequency Control (LFC). The proposed hybrid MFAC–PID framework integrates an incremental model-free adaptive control (MFAC) law with a low-gain incremental PID damping term. This combination leverages real-time input–output data to determine primary control actions without relying on an explicit plant model, while the PID component supplies supplementary damping based on recent control errors. Furthermore, the controller utilizes online pseudo-gradient estimation to dynamically adapt to stochastic wind fluctuations and $\pm 5\%$ parametric uncertainty. Simulation results demonstrate that the hybrid design substantially enhances Area Control Error (ACE) regulation. Under wind-disturbed conditions, it reduces the aggregated Integral Absolute Error ($IA{E}_{total}$) from 92.76 to 41.10, representing an improvement of over 50% compared with the fixed-gain PID baseline. Additionally, the controller maintains a low computational overhead of 0.306 milliseconds per control cycle. These findings indicate that the hybrid MFAC–PID structure provides a robust, computationally efficient solution for real-time Automatic Generation Control (AGC) in renewable-integrated multi-area power grids. Full article

In modern cyber–physical vehicle networks, the security of component-level Electronic Control Units (ECUs) is essential for overall system reliability. While Controller Area Network(CAN) security is well-studied, the Local Interconnect Network (LIN) has received less attention despite its growing role in critical functions and diagnostic services (UDS). The inherent constraints of the LIN protocol, specifically its low bandwidth and master–slave architecture, make traditional fuzz testing impractical due to extremely long execution times. This paper proposes Batch-based Binary-search Fuzzing and Accelerated Security Testing (BB-FAST), an optimized framework for faster vulnerability detection in LIN-based systems. By integrating batch processing and binary search techniques, BB-FAST overcomes communication bottlenecks and enables efficient error localization. Empirical evaluations on a physical automotive ECU demonstrate that BB-FAST achieves a significant reduction in testing time—up to 97.7% compared to traditional sequential methods. Notably, in scenarios involving critical controller failures, BB-FAST outperformed optimized batch-based approaches by 64.2% through its logarithmic error localization logic. By mitigating these physical limitations through algorithmic optimization, this work enables thorough security verification for LIN-based diagnostic interfaces that was previously constrained by protocol latency, thereby enhancing the integrity of cyber–physical automotive networks. Full article

Maintaining frequency regulation in interconnected power systems becomes increasingly difficult in the presence of nonlinear operating conditions. To address this issue, this study develops a hybrid load frequency control scheme in which a fuzzy fractional-order FOPI–FOPD controller is incorporated within a PIDF framework for a two-area LFC system. The controller parameters are optimized using the Dwarf Mongoose Optimization Algorithm (DMOA) and the Catch Fish Optimization Algorithm (CFOA), while the Integral of Time-Weighted Absolute Error (ITAE) is adopted as the performance criterion. The proposed strategy is examined under both linear and nonlinear scenarios, including the effects of Governor Dead Band (GDB) and Generation Rate Constraints (GRC). In the linear case, the DMOA-based design achieves an ITAE of 0.02939 with a tie-line settling time of 13.5478 s, whereas the CFOA-based design produces a bounded and convergent response with an ITAE of 0.03937 and a settling time of 14.4947 s. When GDB nonlinearity is introduced, the DMOA-tuned controller exhibits performance deterioration, yielding an ITAE of 0.1098 and a settling time of 19.0416 s, while the CFOA-tuned design shows more favorable time-domain performance with a lower ITAE of 0.05845 and a bounded settling time of 16.3595 s. These findings indicate that the CFOA-optimized PIDF–Fuzzy FOPI–FOPD controller provides an effective LFC solution under the examined nonlinear operating conditions. Full article

An improved Sinh Cosh optimizer (ISCHO) is proposed to resolve load frequency control (LFC) tasks. The original Sinh Cosh optimizer (SCHO) employs a fixed iteration-based switching function to balance exploration and exploitation, which lacks awareness of search dynamics and leads to inefficient optimization. Therefore, this paper proposes a “first grabbing then washing” strategy to dynamically balance exploration and development. The proposed ISCHO technique is tested on 13 benchmark functions and compared with Particle Swarm Optimization, Sine Cosine Algorithm, and Grey Wolf Optimizer, demonstrating superior optimization performance. Furthermore, a new controller based on the two-degree-of freedom PID controller (2DOF-PID), the two-degree-of freedom with double integral feedback PID controller (2DOF-PIDF-II), is proposed. A two-area multi-source interconnected power system, incorporating thermal, hydraulic, wind, and solar generation units with nonlinearities (GRC and GDB), uncertainties, and load fluctuations, is employed to validate the proposed approach. Quantitative results under step load perturbation demonstrate that the ISCHO-optimized 2DOF-PIDF-II controller significantly outperforms other methods. For area 1 frequency deviation, ISCHO reduces the maximum overshoot by 38.37%, 19.09%, and 21.48% compared to PSO, SCA, and SCHO. For tie-line power deviation, maximum overshoot is reduced by 53.00% compared to PSO. These results confirm that the proposed ISCHO-tuned 2DOF-PIDF-II controller substantially enhances system frequency stability under various operating conditions. Full article

Interconnected fractures induced by coal mining, known as water-conducting fracture zones (WCFZs), form a fractured zone where water from overlying aquifers flows into the goaf. Substantial findings have been established on the development height of WCFZs; however, these analyses have been based on intact structures or rock masses. Research on how primary fissures or other water-conducting structures influence the development of WCFZs remains limited. The mining seam of the Gaojiapu Coal Mine in the Ordos Basin, China, is overlaid by a gigantic and highly confined Cretaceous aquifer. Additionally, the primary fissures of the overlying strata are highly developed. Geophysical inversion of the primary fissures and vertical and horizontal drilling were undertaken in order to systematically investigate the characteristics of WCFZ development in the overlying strata. The results show that a dense network of primary fissures is connected with the middle and lower Cretaceous aquifer developed in Mining Zone 1. These fissures are prone to connecting with mining-induced fractures to form the highly developed WCFZs observed and verified in this study. A grouting engineering approach was adopted at the Gaojiapu Coal Mine to block the primary fissures in advance, as this can effectively control the abnormal development of the WCFZs and decrease the discharge of mine water, ultimately protecting the water resources of the Cretaceous aquifer. Our research clarifies the significant role of primary fissures in the development of water-conducting fracture zones, and provides important theoretical guidance for the accurate prediction and prevention of mine roof water hazards in areas with similar mining conditions. Full article

This study employs a difference-in-differences (DID) design to evaluate the impact of China’s Environmental Vertical Management Reform (EVMR) on urban concentrations of six major air pollutants. The findings reveal a pronounced efficacy hierarchy: the EVMR significantly reduces PM_2.5, PM₁₀, and SO₂, but its effects on the remaining pollutants are heterogeneous. We find no statistically significant impact on NO₂ or O₃, while CO exhibits a counterintuitive pattern—remaining unaffected in the immediate term but showing a significant lagged increase in the second and third years post-reform. In the year of implementation, the reform reduced PM_2.5, PM₁₀, and SO₂ concentrations by 15.4%, 15.5%, and 9.7%, respectively. While reductions for particulate matter persisted over the following two years, the effect on SO₂ was largely confined to the implementation year. Treatment effects exhibit selective heterogeneity: the SO₂ reduction was significantly stronger in less developed cities, while a far more pronounced amplification emerged for cities located in key national air pollution governance areas. Mediation analysis confirms that strengthened environmental enforcement—measured by increased imposition of penalties—operates as a significant channel for pollution reduction, with the indirect effect notably strongest for SO₂ in the reform year. In conclusion, this study provides comprehensive evidence on the differential impacts of EVMR. Our findings validate the efficacy of this centralized governance model in curbing particulate and sulfur pollution, but also highlight its limitations in addressing secondary pollutants like O₃. More alarmingly, the unintended lagged increase in CO reveals a critical pollution-shifting effect: the very measures that achieve deep SO₂ reduction may inadvertently elevate CO through interconnected engineering pathways. These insights are crucial for designing more targeted, multi-pollutant control policies in China and other transitioning economies. Full article

Seabed response and local scouring around pile groups under combined wave–current loading pose critical threats to the stability and long-term performance of offshore structures, particularly those supporting offshore renewable energy infrastructures. In this study, we present a systematic experimental investigation on the pore-water pressure and local scour around pile groups subjected to regular waves, combined regular wave–current conditions, and irregular waves generated using the JONSWAP spectrum under wave-only conditions. Pore-water pressures and seabed morphology were analyzed for different hydrodynamic conditions, pile spacings, and pile arrangements. The experimental results demonstrate that the presence and magnitude of current are the dominant factors controlling scour development. Increasing the current velocity from 0 to 0.25 m/s leads to a three (3) to five (5) times increase in maximum scour depth, whereas comparable variations in wave height and wave period produce relatively small effects. The direction of a current affects the location of maximum scour, with the wave–forward current condition promoting the development of an interconnected scour area within the pile array and wave–opposing current condition, shifting local scour toward downstream piles. Small-spaced piles ($G/D$ = 1) intensify hydrodynamic interactions and increase scour depth by approximately 30–40% compared with wider spacing. Irregular waves generate more spatially distributed but shallower scour than regular waves of comparable wave characteristics. These findings provide insights into the mechanisms governing seabed instability around pile group foundations and contribute to more sustainable design and operation of offshore infrastructure, such as offshore wind turbine foundations. Full article

Bacteria play an important role in addressing challenges in rice production by promoting plant growth and enhancing stress tolerance through multiple mechanisms. Different types of soil bacteria affect rice growth by improving nutrient absorption, managing stress, and enhancing root structure. The relationship between rice plants and bacteria is intricate, as these bacteria can help reduce problems like salt stress, heavy metal toxicity, and infections. This review summarises studies published up to 2025 on how bacteria influence rice roots, including aspects like root length, density, biomass, and volume. Bibliometric analysis shows an increase of over 900% in research interest after 2020, with most studies conducted under controlled conditions and limited field validation. In addition to identifying key bacterial groups such as Bacillus, Pseudomonas, Burkholderia, and Azospirillum, this review identifies research gaps related to context dependency, strain specificity, and scalability. We have also emphasised the need for multi-strain inoculation strategies, field-scale experiments, and integration of microbial selection with rice breeding. The synthesis has highlighted that bacterial strains do not simply stimulate root growth but actively reprogram rice root architecture, modulating elongation, branching, density, and surface area as a response to environmental constraints. These effects are mediated by interconnected mechanisms that include phytohormone production, nutrient solubilisation, deaminase activity, stress-related gene regulation, and microbiome-driven feedback involving root exudation. Overall, viewing bacteria as regulators of root developmental dynamics rather than simple biofertilisers provides new insights for designing climate-adapted and sustainable rice production systems. Full article

p-Nitrophenol (PNP), a highly toxic and recalcitrant organic pollutant prevalent in industrial wastewater, poses severe challenges to traditional Fenton treatment technologies. In this study, a novel nanoporous catalyst is synthesized via a combined annealing–dealloying strategy. Annealing at 550 °C and 600 °C induces partial crystallization, generating α-Fe and Fe₂B phases that serve as preferential corrosion sites during chemical dealloying. This process results in a three-dimensionally interconnected nanoporous structure, which significantly increases the specific surface area of the catalyst to 2.642 m²/g. The optimized nanoporous catalyst exhibits excellent degradation performance, achieving complete removal of PNP within 30 min under room temperature reaction conditions. Notably, kinetic analysis reveals a degradation mechanism involving adsorption and Fenton-like catalysis. The high specific surface area provides abundant active sites for PNP adsorption, while the enhanced Fe²⁺ dissolution synergistically accelerates the degradation. The adsorption kinetic follows a pseudo-second-order model, and the degradation kinetic conforms to a first-order model, with activation energy analysis further confirming a surface-reaction-controlled process. This work provides a feasible approach and technical reference for designing efficient porous catalysts based on amorphous alloys for advanced treatment of refractory organic wastewater. Full article

Microplastics (MPs) represent pervasive contaminants in aquatic ecosystems, acting as carriers for persistent organic pollutants like polycyclic aromatic hydrocarbons (PAHs). This study systematically investigated the occurrence, composition, and ecological risks of MPs and adsorbed polycyclic aromatic hydrocarbons in urban drainage sediments from three Yangtze River cities: Chongqing (Yongchuan), Changzhou (Jintan), and Shanghai (Tongji University campus). The key findings revealed MPs’ abundances ranging from 130 to 564 items/100 g (mean: 346 items/100 g), with peak concentrations in campus commercial areas (498.4 items/100 g) and academic zones (420 items/100 g). Predominant polymers included polypropylene (PP, 15.29%), polyethylene terephthalate (PET, 15.88%), and chlorinated polyethylene (CPE, 14.98%). Granular MPs (75–300 μm) dominated particle size (50.09%), while colored MPs (66.54%)—particularly red (32.84%) and black (27.92%)—were most prevalent. Polycyclic aromatic hydrocarbons adsorbed on MPs ranged from 0.88 to 120.59 ng/g (mean: 5.76–67.66 ng/g), dominated by four-ring compounds (44.59%). Sediment-associated polycyclic aromatic hydrocarbons ranged from 0.63 to 60.09 ng/g (mean: 2.12–36.96 ng/g), with 5–6-ring polycyclic aromatic hydrocarbons (42%) as primary constituents. Significant correlations emerged between four-ring polycyclic aromatic hydrocarbons and fibrous MPs (r = 0.33, p = 0.021) and black MPs (r = 0.23, p = 0.04). This study underscores urban drainage sediments as critical reservoirs and transport pathways for MPs and polycyclic aromatic hydrocarbons, which is crucial for sustainable management for urban drainage systems. We advocate for implementing targeted management strategies that prioritize three interconnected approaches: enhanced monitoring of high-risk zones (particularly commercial areas), focused control of small-sized MPs (<300 μm) due to their elevated ecological threats, and systematic mitigation of PAH-MP co-contamination in densely populated catchments to disrupt pollutant transmission pathways. Full article

The development of efficient and durable oxygen evolution reaction (OER) catalysts from earth-abundant materials is essential for advancing alkaline water electrolysis. Herein, nanograss-like CoMn₂O₄ electrode films are directly grown on stainless-steel substrates via a temperature-controlled hydrothermal approach, and their OER performance is systematically investigated. The CoMn₂O₄ obtained at 120 °C (CMO-120) delivers the best catalytic activity in 1.0 M KOH, requiring an overpotential of 292 mV at 10 mA cm⁻², which is lower than those synthesized at 150 (CMO-150) and 90 °C (CMO-90). Notably, activity of CMO-120 becomes even more pronounced at elevated current densities, achieving the low overpotential of 434 mV even at 300 mA cm⁻², substantially outperforming both CMO-90 and CMO-150 electrodes. The enhanced activity is attributed to an interconnected nanograss architecture with mixed Co²⁺/Co³⁺ and Mn²⁺/Mn³⁺ redox couples and abundant defect-related oxygen species, which result in increased electrochemically active surface area and improved charge transportation throughout the nanograss architecture that facilitate OH⁻ adsorption and OER intermediate transformation. Furthermore, CMO-120 demonstrates excellent durability (100 h) after electro-oxidation-induced surface activation. These findings highlight precise temperature regulation as an effective strategy for optimizing Mn-Co spinel for efficient alkaline OER applications. Full article

Parallel laying of high-voltage cables will generate a zero-sequence current, due to spatial electromagnetic induction, which reduces the cable’s current-carrying capacity, causing heating and corrosion of the grounding points and deteriorating grounding performance. Currently, there is a lack of effective control measures. This article establishes a calculation model for the cable sheath current under the condition of double circuit cable cross interconnection grounding, analyzes the causes of a zero-sequence grounding current in a double circuit cable sheath, and proposes an optimal phase sequence selection method, considering load changes with the goal of maximizing the probability of the cable sheath current, not exceeding the standard. The results show that when the double circuit cable is evenly distributed in the cross interconnection section, the zero-sequence grounding current will be generated on the metal sheath of the cable, causing an excessive total grounding current. By applying the proposed probability-based phase-sequence optimization, the likelihood that both circuits simultaneously satisfy the sheath-current criterion can be significantly improved; for example, under representative layouts and load distributions, the “both-within-limit” probability can reach 53.3% (horizontal layout), 76.2% (horizontal equilateral triangle layout), 90.5% (vertical layout), and 81.6% (vertical equilateral triangle layout). For different working conditions, selecting the optimal load phase sequence combination by maximizing the probability of the sheath current and not exceeding the standard within the current carrying area can help to reduce the cable sheath current. Full article

Traditional flexible polyurethane (PU) foams frequently exhibit limited mechanical support and suboptimal moisture–heat regulation, which can compromise the microenvironmental comfort required for high-quality sleep. In this study, natural luffa fibers (LF) were incorporated as a microstructural modifier to simultaneously enhance the mechanical and moisture–heat regulation performance of PU foams. PU/LF composite foams with varying LF loadings were prepared via in situ polymerization, and their foaming kinetics, cellular morphology evolution, and physicochemical characteristics were systematically investigated. The results indicate that LF functions both as a reinforcing skeleton and as a heterogeneous nucleation site, thereby promoting more uniform bubble formation and controlled open-cell development. At an optimal loading of 4 wt%, the composite foam developed a highly interconnected porous architecture, leading to a 7.9% increase in tensile strength and improvements of 19.4% and 22.6% in moisture absorption and moisture dissipation rates, respectively, effectively alleviating the heat–moisture accumulation typically observed in unmodified PU foams. Ergonomic pillow prototypes fabricated from the optimized composite further exhibited enhanced pressure-relief performance, as evidenced by reduced peak cervical pressure and improved uniformity of contact-area distribution in human–pillow pressure mapping, together with an increased SAG factor, indicating improved load-bearing adaptability under physiological sleep postures. Collectively, these findings elucidate the microstructural regulatory role of biomass-derived luffa fibers within porous polymer matrices and provide a robust material basis for developing high-performance, sustainable, and ergonomically optimized sleep products. Full article