Search Results (2,047)

The purpose of this paper is to investigate a class of novel symmetric coupled fuzzy fractional partial differential equation system involving the Caputo–Katugampola (C-K) generalized Hukuhara (gH) derivative. Within the framework of C-K gH differentiability, two types of gH weak solutions are defined, and their existence is rigorously established through explicit constructions via employing Schauder fixed point theorem, overcoming the limitations of traditional Lipschitz conditions and thereby extending applicability to non-smooth and nonlinear systems commonly encountered in practice. A typical numerical example with potential applications is proposed to verify the existence results of the solutions for the symmetric coupled system. Furthermore, we introduce Ulam–Hyers stability (U-HS) theory into the analysis of such symmetric coupled systems and establish explicit stability criteria. U-HS ensures the existence of approximate solutions close to the exact solution under small perturbations, and thereby guarantees the reliability and robustness of the systems, while it prevents significant deviations in system dynamics caused by minor disturbances. We not only enrich the theoretical framework of fuzzy fractional calculus by extending the class of solvable systems and supplementing stability analysis, but also provide a practical mathematical tool for investigating complex interconnected systems characterized by uncertainty, memory effects, and spatial dynamics. Full article

Basin insulator is a critical component of gas-insulated transmission line (GIL) systems. Air gap defects and surface crack defects may form in basin insulators due to casting, installation, or transport processes. This phenomenon poses a significant threat to long-term safety and stability and may even lead to partial discharges. This study establishes a simulation model of a GIL system-incorporating insulator to systematically analyze the influence patterns of various defects on the insulation characteristics of the basin insulator. Meanwhile, an equation predicting the relationship between defect size and maximum electric field strength is derived. The research revealed the following: For short air gap defects near the conductor, increasing length reduces their impact on the surrounding electric field, with the radius having minimal effect; for long air gap defects near the conductor, increasing length amplifies their influence. Smooth air gap defects distant from the conductor show negligible variation in maximum electric field strength with increasing length, while unsmooth air gap defects exhibit more pronounced effects at shorter lengths. Under identical conditions, unsmooth air gap defects demonstrate greater influence on the electric field than smooth ones. For elliptical surface defects, variations in radius show the strongest distortion. The degree of influence from surface crack defects correlates directly with their proximity to the conductor. These findings provide critical diagnostic criteria for assessing the insulation performance of basin insulator under damaged conditions. Full article

Background: Carbon-fiber-reinforced polyetheretherketone (CFR-PEEK) vertebral-body replacements (VBRs) aim to mitigate subsidence, minimize imaging artifacts, and facilitate radiation planning while preserving fusion potential. We assessed the safety and efficacy of a novel modular, titanium-coated CFR-PEEK VBR (Kong^®) for anterior column reconstruction (ACR) in the thoracolumbar spine. Primary question: Does the implant safely and effectively achieve and maintain kyphosis correction after ACR for trauma and neoplasms? Methods: A single-center retrospective case series was performed on 28 patients who underwent thoracolumbar ACR with the Kong^® VBR for fractures or tumors (2020–2021). The primary outcome was the bi-segmental kyphotic angle (BKA). Secondary outcomes were screw loosening, cage height loss, fusion rate, subsidence, and tilting. Clinical status was recorded with Odom criteria, Karnofsky Performance Status (KPS), and AOSpine PROST. Results: Twenty-eight patients (mean age, 61 yr; 33% female; mean follow-up, 17.7 mts) were studied. Mean postoperative BKA correction was 16.5° (p = 0.006) and remained 14.5° at final follow-up (p = 0.008); loss of correction was 2.0° (p = 0.568). Subsidence, cage height, and sagittal tilt were unchanged. Fusion (Bridwell grade I/II) was observed in 95% on CT. One deep surgical-site infection occurred. At final follow-up, 91% of patients were graded “excellent” or “good” by Odom. KPS improved by 20 points (p = 0.031), and mean AOSpine PROST was 56.9. Conclusions: Single-center early results indicate that the modular titanium-coated CFR-PEEK VBR is a safe, effective adjunct for thoracolumbar ACR in trauma and neoplasm, providing durable kyphosis correction, mechanical stability and high fusion rates and grants for improved follow-up imaging quality. Full article

The main characteristics of attention deficit hyperactivity disorder (ADHD) are associated with inattention, impulsivity, and/or hyperactivity. Those diagnosed with this neurodevelopmental disorder present with executive function and motor difficulties, which have repercussions in educational, occupational, or social areas. On the other hand, it has been evidenced that the regular practice of physical activity or exercise or sport could produce improvements in areas with difficulties. It is for this reason that the objective of the present review was to describe and analyze the effects of the practice of physical activity, exercise, or sport on executive functions in adults diagnosed with ADHD through the scientific literature (registry: INPLASY202530105). The articles indexed in PubMed (1145), Scopus (43), and WoS (2910) were searched using the following keywords: “Adult” OR “Adults” AND “Attention-Deficit/Hyperactivity Disorder” OR “Attention-Deficit with Hyperactivity Disorder” AND “Physical activity” OR “Exercise” OR “Sports” OR “Sport” AND “Executive Function”. In addition, four articles were identified using other search engines. A total of 10 articles met the selection criteria. TESTEX was used to assess the quality of the articles, and TIDierR was used to report the results. Of the ten included studies, nine mention an improvement in inhibitory control, six in selective attention, three in cognitive flexibility, and one in working memory (all p < 0.05). It was concluded that the practice of physical activity, exercise, or sport has a positive and significant effect on the executive functions of adults with ADHD, specifically on selective attention, inhibitory control, and cognitive flexibility. Furthermore, benefits were observed in depression, brain activation, and stability. Among the limitations is the lack of a meta-analysis, which makes it difficult to quantify and recommend which intervention is most effective for this population. Furthermore, the various types and degrees of ADHD were not considered. Full article

This paper presents the results of seakeeping tests conducted on the Tritor, a remotely controlled autonomous unmanned surface vehicle (USV) featuring a trimaran hull design known as the Three Slender Cylinders Hull (3SCH) and equipped with electric propulsion. Previous research focused on the vehicle’s design, prototype development, and initial functional testing. Tritor is characterised by its simple design and construction, reliable propulsion system, and excellent stability and manoeuvrability. Its control and navigation systems have demonstrated effective performance in both remote-controlled and fully autonomous modes. In the present study, seakeeping tests were carried out in a towing tank, with repeated trials conducted at various speeds and wavelengths. The selected wavelengths were close to the vehicle’s length, where the most significant responses were expected. Test speeds ranged from 1.0 to 2.5 m per second, based on prior operational experience with the vehicle. Due to the constraints of the towing tank, all wave directions were limited to head seas. Measurements included heave and pitch motions. Vertical accelerations at the vehicle’s centre of gravity were derived from the heave data and used as a key indicator of seakeeping performance. The results were evaluated against established seakeeping criteria related to vessel operability and structural safety. Full article

Nickel-based alloys, including Inconel 718 and alloy 625, are indispensable in industries such as aerospace, marine, and nuclear energy due to their exceptional mechanical strength, high-temperature performance, and corrosion resistance. However, these very properties pose severe machining challenges, such as accelerated tool wear, poor surface finish, and high cutting forces. Although several studies have investigated coatings, lubrication strategies, and process optimization, a comprehensive and up-to-date integration of these advancements is still lacking. To address this gap, a systematic review was conducted using Web of Science and Scopus databases. The inclusion criteria focused on peer-reviewed journal and conference articles published in the last eleven years (2014–2025), written in English, and directly addressing machining of nickel-based alloys, with particular emphasis on tool coatings, lubrication/cooling technologies, and machinability optimization. Exclusion criteria included duplicate records, non-English documents, papers lacking experimental or modeling results, and studies unrelated to tool life or coating performance. Following this screening process, 101 high-quality articles were selected for detailed analysis. The novelty of this work lies in synthesizing comparative insights across TiAlN, TiSiN, and CrAlSiN coatings, alongside advanced lubrication methods such as HPC, MQL, nano-MQL, and cryogenic cooling. Results highlight that CrAlSiN coatings retain hardness up to 36 ± 2 GPa after exposure to 700 °C and extend tool life by 4.2× compared to TiAlN, while optimized cooling strategies reduce flank wear by over 30% and improve tool longevity by up to 133%. The integration of coating performance, thermal stability, and lubrication effects into a unified framework provides actionable guidelines for machining optimization. The study concludes by proposing future research directions, including hybrid coatings, real-time process monitoring, and sustainable lubrication technologies, to bridge the remaining gaps in machinability and promote industrial adoption. This integrative approach establishes a robust foundation for advancing machining strategies of nickel-based superalloys, ensuring improved productivity, reduced costs, and enhanced component reliability. Full article

The predator–prey model is a fundamental mathematical tool in ecology used to understand the dynamic relationship between predator and prey populations. This study develops a fractional-order delayed dynamical model for a four-species food web, which includes an intermediate predator feeding on two prey species and a top predator preying on all three species. The boundedness of the system’s solutions is first rigorously established using the Laplace transform method. Next, a nonlinear dynamical analysis is performed to determine the existence conditions and local stability of both the trivial and positive equilibrium points. In particular, by treating the time delay as a bifurcation control parameter, explicit criteria for the onset of Hopf bifurcation are derived. Theoretically, when the delay magnitude exceeds a critical threshold, the system loses stability and exhibits sustained oscillatory behavior. Finally, systematic numerical simulations are performed under specific parameter settings. The effects of varying fractional orders and delay magnitudes on the system’s dynamics are quantitatively explored, and the results show strong agreement with the theoretical predictions. Full article

This study focuses on improving the control system of vehicle suspension, which is critical for optimizing driving dynamics and enhancing passenger comfort. Traditional passive suspension systems are limited in their ability to effectively mitigate road-induced vibrations, often resulting in compromised ride quality and vehicle handling. To overcome these limitations, this work explores the application of active suspension control strategies aimed at improving both comfort and performance. Type-I and Type-II Fuzzy Logic Control (FLC) methods were designed and implemented to enhance vehicle stability and ride quality. The Harris Hawks Optimization (HHO) algorithm was employed to optimize the membership function parameters of both fuzzy control types. The system was tested under two distinct road disturbance inputs to evaluate performance. The designed control methods were evaluated in simulations where results demonstrated that the proposed active control approaches significantly outperformed the passive suspension system in terms of vibration reduction. Specifically, the Type-II FLC achieved a 54.7% reduction in vehicle body displacement and a 76.8% reduction in acceleration for the first road input, while improvements of 75.2% and 72.8% were recorded, respectively, for the second input. Performance was assessed using percentage-based metrics and Root Mean Square Error (RMSE) criteria. Numerical and graphical analyses of suspension deflection and tire deformation further confirm that the proposed control strategies substantially enhance both ride comfort and vehicle handling. Full article

Selecting an appropriate Multi-Criteria Decision-Making (MCDM) algorithm for optimizing marine diesel engine operation presents a complex challenge due to the diversity in mathematical formulations, normalization schemes, and trade-off resolutions across methods. This study systematically evaluates fourteen MCDM algorithms, which are grouped into five primary methodological categories: Scoring-Based, Distance-Based, Pairwise Comparison, Outranking, and Hybrid/Intelligent System-Based methods. The goal is to identify the most suitable algorithm for real-time performance optimization of two stroke marine diesel engines. Using Diesel-RK software, calibrated for marine diesel applications, simulations were performed on a variant of the MAN-B&W-S60-MC-C8-8 engine. A refined five-dimensional parameter space was constructed by systematically varying five key control variables: Start of Injection (SOI), Dwell Time, Fuel Mass Fraction, Fuel Rail Pressure, and Exhaust Valve Timing. A subset of 4454 high-potential alternatives was systematically evaluated according to three equally important criteria: Specific Fuel Consumption (SFC), Nitrogen Oxides (NO_x), and Particulate Matter (PM). The MCDM algorithms were evaluated based on ranking consistency and stability. Among them, Proximity Indexed Value (PIV), Integrated Simple Weighted Sum Product (WISP), and TriMetric Fusion (TMF) emerged as the most stable and consistently aligned with the overall consensus. These methods reliably identified optimal engine control strategies with minimal sensitivity to normalization, making them the most suitable candidates for integration into automated marine engine decision-support systems. The results underscore the importance of algorithm selection and provide a rigorous basis for establishing MCDM in emission-constrained maritime environments. This study is the first comprehensive, simulation-based evaluation of fourteen MCDM algorithms applied specifically to the optimization of two stroke marine diesel engines using Diesel-RK software. Full article

Background: Anterior shoulder dislocations are common in athletes, particularly in contact sports. Surgical stabilization reduces recurrence, but the optimal timing—early versus delayed—remains uncertain, especially for in-season athletes. Methods: A systematic search of PubMed, Embase, and Cochrane (2013–2023) yielded 945 articles; 15 met the inclusion criteria. Data were charted on procedure type, outcomes, follow-up, patient group, and timing of surgery. Search terms, e.g., ‘shoulder’, ‘athlete’, ‘anterior’ and ‘shoulder dislocation’, were used in a broad search protocol casting a wide net to maximize the likelihood of capturing all available data. Results: Surgery was superior to conservative care in lowering recurrence and enabling return-to-play, with arthroscopic and combined procedures most effective in high-contact sports. Conservative management carried higher instability risk. Evidence directly comparing early versus delayed surgery was scarce, and therefore inconclusive. Conclusions: Surgical stabilization remains the treatment with better outcomes compared to conservative treatment for young athletes. Still, athletes opt to delay surgery until postseason, with the impact of delaying surgery being unclear. Further research is needed to evaluate early versus delayed surgery regarding recurrence, joint damage, and return to sport. Full article

This review consolidates recent advancements in microbial biotechnology for sustainable food systems. It focuses on the fermentation processes used in this sector, emphasizing precision fermentation as a source of innovation for alternative proteins, fermented foods, and applications of microorganisms and microbial bioproducts in the food industry. Additionally, it explores food preservation strategies and methods for controlling microbial contamination. These biotechnological approaches are increasingly replacing synthetic additives, contributing to enhanced food safety, nutritional functionality, and product shelf stability. Examples include bacteriocins from lactic acid bacteria, biodegradable microbial pigments, and exopolysaccharide-based biopolymers, such as pullulan and xanthan gum, which are used in edible coatings and films. A comprehensive literature search was conducted across Scopus, PubMed, ScienceDirect, and Google Scholar, covering publications from 2014 to 2025. A structured Boolean search strategy was applied, targeting core concepts in microbial fermentation, bio-based food additives, and contamination control. The initial search retrieved 5677 articles, from which 370 studies were ultimately selected after applying criteria such as duplication removal, relevance to food systems, full-text accessibility, and scientific quality. This review highlights microbial biotransformation as a route to minimize reliance on synthetic inputs, valorize agri-food byproducts, and support circular bioeconomy principles. It also discusses emerging antimicrobial delivery systems and regulatory challenges. Overall, microbial innovations offer viable and scalable pathways for enhancing food system resilience, functionality, and environmental stewardship. Full article

Hybrid marine energy platforms that integrate wave energy converters (WECs) and hydrokinetic turbines (HKTs) offer potential to improve energy yield and system stability in marine environments. This study identifies a compatible WEC–HKT integrated system concept through a structured concept selection framework based on multi-criteria decision analysis (MCDA). The framework follows a two-stage process: individual technology assessment using eight criteria (efficiency, TRL, self-starting capability, structural simplicity, integration feasibility, environmental adaptability, installation complexity, and indicative cost) and pairing evaluation using five integration-focused criteria (structural compatibility, PTO feasibility, mooring synergy, co-location feasibility, and control compatibility). Criterion weights were assigned through a four-level importance framework based on expert judgment from 11 specialists, with unequal weights for the individual evaluation and equal weights for the integration stage. Four WEC types (oscillating water column, point absorber, overtopping wave energy converter, and oscillating wave surge converter) and four HKT types (Darrieus, Gorlov, Savonius, and hybrid Savonius–Darrieus rotor) are assessed using literature-derived scoring and weighted ranking. The results show that the oscillating water column achieved the highest weighted score among the WECs with 4.05, slightly ahead of the point absorber, which scored 3.85. For the HKTs, the Savonius rotor led with a score of 4.05, surpassing the hybrid Savonius–Darrieus rotor, which obtained 3.50, by 0.55 points. In the pairing stage, the OWC–Savonius configuration achieved the highest integration score of 4.2, surpassing the PA–Savonius combination, which scored 3.4, by 0.8 points. This combination demonstrates favorable structural layout, PTO independence, and mooring simplicity, making it the most promising option for early-stage hybrid platform development. Full article

Addressing the challenge of efficient gas control in high-gas coal mines with ultra-long panels, this study focuses on the No. 8 coal seam in the Baode Mine. A multi-parameter integrated methodology was developed to establish a hierarchical classification system of Gas Geological Units (GGUs), aiming to identify regions suitable for large-scale gas extraction. The results indicate that the overall structure of the No. 8 coal seam is a simple monocline. Both gas content (ranging from 2.0 to 7.0 m³/t) and gas pressure (ranging from 0.2 to 0.65 MPa) generally increase with burial depth. However, local anomalies in these parameters, caused by geological structures and hydrogeological conditions, significantly limit the effectiveness of large-scale drainage using ultra-long boreholes. Based on key criteria, the seam was classified into three Grade I and ten Grade II GGUs, distinguishing anomalous zones from homogeneous units. Among the Grade II units, eight (II-i to II-viii) were identified as anomalous zones with distinct geological constraints, while two (II-ix and II-x) exhibited homogeneous gas geological parameters. Practical implementation of large-scale gas extraction strategies—including underground ultra-long boreholes and a U-shaped surface well—within the homogeneous Unit II-x demonstrated significantly improved gas drainage performance, characterized by higher methane concentration, greater flow rate, enhanced temporal stability, and more favorable decay characteristics compared to conventional boreholes. These findings confirm the critical role of GGU delineation in guiding efficient regional gas control and ensuring safe production in similar high-gas coal mines. Full article

Background: Total hip arthroplasty (THA) is a common procedure, yet instability and dislocation remain leading causes of revision. Dual mobility (DM) acetabular constructs improve stability, but comparative data across modular DM systems are limited. This study compared the safety and efficacy of three modular DM implants in primary THA, focusing on acetabular revision and functional recovery. Methods: We retrospectively reviewed 963 primary THAs performed from 2016–2024 using three modular DM systems. Patients with revision or bilateral THA, age < 18, or <2 years of follow-up were excluded. Outcomes included acetabular revision, 90-day readmission, and Hip Disability and Osteoarthritis Outcome Score for Joint Replacement (HOOS, JR). Kaplan–Meier analysis estimated 3-year implant survivorship for each implant, and non-inferiority of Implant A was tested against a combined “Dual Mobility Control” cohort (Implants B + C) using a prespecified −10% margin. Results: A total of 297 patients met inclusion criteria (142 Implant A, 110 Implant B, 45 Implant C). Revision rates were 4.9% for Implant A, 6.4% for Implant B, and 8.9% for Implant C. HOOS, JR scores improved significantly in all cohorts with comparable 2-year outcomes. Kaplan–Meier analysis showed 3-year survivorship of 98.3% for Implant A, 98.4% for Implant B, and 96.9% for Implant C (log-rank p = 0.053). The Dual Mobility Control cohort survivorship was 98.0%, and the difference between Implant A and controls (95% CI: −2.19% to 2.69%) met the non-inferiority margin (log-rank p = 0.796). Conclusions: Implant A demonstrated non-inferior 3-year survivorship and comparable short-term patient-reported outcomes relative to two other modular DM implants. Larger, multicenter studies with longer follow-up are warranted to confirm these findings. Full article

Background: C3 glomerulopathies (C3G), including dense deposit disease (DDD) and C3 glomerulonephritis (C3GN), are rare kidney disorders driven by dysregulation of the alternative complement pathway. Eculizumab, a terminal complement inhibitor targeting C5, has emerged as a potential therapeutic option in these conditions. This systematic review evaluated the efficacy and safety of eculizumab in patients with C3G or DDD. Methods: Literature searches in PubMed and Cochrane databases identified case reports and case series reporting eculizumab use. Results: Only eight studies involving ten patients met the inclusion criteria. Eculizumab stabilized renal function and reduced proteinuria in most cases, especially when C5b-9 deposition was present. Histopathological improvements were variable, and recurrence after discontinuation occurred in some patients. Responses were limited in cases with alternative mechanisms of C5 activation. Conclusions: Eculizumab offers clinical benefit in select C3G and DDD patients but does not address the underlying cause of complement dysregulation. The need for long-term therapy, incomplete histologic resolution, and risk of relapse underscore the necessity of larger trials and the development of personalized treatment strategies. Full article