Search Results (4,578)

The Weibull distribution is one of the most versatile and widely applied continuous probability distributions in reliability engineering, survival analysis, wind-energy modelling, and extreme-value theory. Classical parameter estimation relies on maximum likelihood estimation or method-of-moments using integer-order moments, both of which may suffer from instability or high variance in small to moderate samples. This paper develops a rigorous framework for estimating Weibull parameters by combining the maximum-entropy principle with fractional-order moment constraints, i.e., constraints of the form $E\left[X^r\right]$ for non-integer $r>0$. A central theme of the paper is symmetry: we show that the maximum-entropy density subject to a finite set of fractional-moment constraints uniquely recovers the Weibull family, and that the underlying moment-matching system, while not symmetric in every sense considered in an earlier draft (see Remark ), possesses a precisely characterised duality under joint rescaling and relabelling of the exponent pair, together with a log-moment map whose local curvature is strictly positive and increasing with exponent spacing rather than symmetric about a fixed midpoint. We derive closed-form expressions relating the Lagrange multipliers to the shape and scale parameters, establish new sound theoretical results on the symmetric behaviour of the moment-ratio function and its sensitivity, and propose a numerically stable algorithm for solving the resulting moment-matching system. Extensive Monte Carlo experiments demonstrate that the proposed maximum-entropy fractional-moment estimator achieves a bias and root-mean-square error that are comparable to, and for small-to-moderate samples somewhat better than, maximum likelihood estimation, with the size of the advantage depending on how closely the chosen exponent pair tracks the true shape parameter. Applications to real wind-speed data and composite-material fatigue life data illustrate the practical utility of the method. The paper contributes both to the information-theoretic foundations of distribution fitting and to applied statistical methodology, with symmetry serving as both a diagnostic tool and a unifying structural principle throughout. Full article

Biochar is no longer considered merely a substitute for conventional fillers in asphalt materials; rather, it represents a multifunctional modifier that aligns with the goals of sustainable road design and urban mobility in smart cities. Its application now extends to the rheological modification of asphalt binders, mitigation of asphalt fume emissions, improvement in aging resistance and interfacial adhesion, and assessment of carbon sequestration potential. Biochar can improve the high-temperature stability, rutting and aging resistance, and asphalt–aggregate adhesion of asphalt materials in a suitable dosage, and at the same time reduce emissions of volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), hydrogen sulfide (H₂S), and other fumes. However, the above effects are highly dependent on the biochar feedstock, production process, physicochemical properties, particle size, dosage and degree of dispersion. An excess amount or uneven distribution will reduce the crack resistance and fatigue life at low temperatures; phase separation may also occur and VOC emissions will increase. Therefore, the main problem in this area has shifted from whether biochar is effective to when it can be applied for particular pavement performance goals, what pollutant control targets are aimed for, and over what life-cycle periods. This review integrates evidence obtained at the binder, mastic, and mixture scales and critically evaluates the influence of biochar on pavement performance, fume emissions, aging, interfacial adhesion, and environmental safety. It also argues that empirical dosage selection should be replaced by coordinated optimization of biochar structure, material performance, emission mitigation, and life-cycle impacts. Verification of the low-carbon benefits and environmental safety of biochar-modified asphalt will ultimately require standardized assessment frameworks and consistently defined system boundaries. Ultimately, this work provides a foundation for integrating biochar-modified asphalt into eco-friendly and resilient road infrastructures, aligning with the goals of smart urban mobility and sustainable transportation. Full article

Background/Objectives: Cancer patients undergoing treatment experience a wide range of physical and psychological symptoms that significantly impact their quality of life. This study aimed to evaluate the occurrence and intensity of symptoms in cancer patients using the Edmonton Symptom Assessment System Revised (ESAS-R) during two distinct phases of treatment. Methods: A prospective cohort study with consecutive recruitment of eligible patients within a convenience sample was conducted in a tertiary public cancer hospital in Athens, Greece. The initial sample included 189 adult cancer patients assessed after the third chemotherapy cycle. Of these, 105 patients completed a second assessment after the final chemotherapy cycle and constituted the longitudinal follow-up sample. Symptom intensity was measured using the 10-item ESAS-R self-report tool. Results: The study population was predominantly female (77.2%), married (71.4%), and diagnosed with breast cancer (59.3%). Statistically significant changes between the two measurements (p < 0.05) were observed in pain, fatigue, and well-being. Total symptom burden scores remained relatively stable, slightly decreasing from 25.09 to 24.19. Age showed a consistent negative correlation with pain (p < 0.001) in the second measurement and nausea across both measurements (p = 0.004 and p = 0.017), indicating that younger patients reported higher symptom intensity. Logistic regression indicated that employment/housework was primarily linked to the total symptom score in Measurement A (p = 0.010), with patients less likely to have high symptom severity (Exp(B) = 0.101). Baseline symptom burden category at Measurement A was identified as a significant predictor of symptom intensity at Measurement B (p = 0.028), with patients presenting mild symptom burden at baseline being less likely to report moderate-to-high symptom burden at the final assessment. Conclusions: While pain, fatigue, and perceived well-being deteriorated from the early to the final chemotherapy cycle, the total symptom burden remained relatively stable. Younger patients appeared to experience higher symptom burden, while lower educational level was associated with higher symptom burden in the univariate analysis at the final assessment, highlighting the need for age-sensitive and educationally tailored nursing interventions to enhance symptom management in oncology settings. Full article

Aluminum alloy is a lightweight, high-strength material based on aluminum matrix with the addition of elements such as copper, magnesium, silicon, zinc, manganese, or lithium. Featuring low density, high specific strength, excellent formability, and outstanding corrosion resistance, it is widely applied in the fields of aerospace, rail transit, automotive lightweighting, and additive manufacturing. In the aerospace sector, fatigue failure constitutes the primary failure mode of load-bearing components. This paper reviews the influence mechanisms of various strengthening technologies, namely shot peening (SP), laser shock processing (LSP), physical vapor deposition (PVD), micro-arc oxidation (MAO), anodic oxidation (ANO), additive manufacturing, casting, extrusion, and heat treatment, on the fatigue properties of aluminum alloys; analyzes the regulatory effects of process principles, coating compositions, and microstructures (grains, phase composition, and interfacial bonding) on crack initiation and propagation; discusses the synergistic effect between plastic deformation strengthening and coating functionality; summarizes the key material and process factors affecting the fatigue life of aluminum alloys; and finally prospects the technical development trends driven by high-reliability service requirements. Full article

Background: Fibromyalgia (FM) is a chronic syndrome characterized by widespread musculoskeletal pain, fatigue, sleep disturbances, and cognitive and affective symptoms. Objectives: This study aimed to examine the acute effects of Resistance Training (RT) and Pilates on pain, functional impact, flexibility, and health-related quality of life in individuals with FM. Methods: In this randomized crossover pilot study, eight adults (7 females, 1 male; mean age: 48.5 ± 8.2 years) with a clinical diagnosis of FM participated. Each participant performed both RT and Pilates sessions in a randomized order. Outcomes were assessed at baseline and 24 h post-intervention using the Fibromyalgia Impact Questionnaire (FIQ), the 36-Item Short Form Health Survey (SF-36), the Visual Analog Scale (VAS) for pain, and the Wells sit-and-reach test (WELLS). Data were analyzed using two-way repeated-measures ANOVA and paired t-tests, with effect sizes (η²p and Cohen’s d) and 95% confidence intervals (95% CI). Statistical significance was set at p < 0.05. No formal sample size calculation was performed. Results: Participants presented a mean body mass index (BMI) of 27.4 ± 4.1 kg/m² and time since diagnosis of 6.2 ± 3.1 years. Within-subject variations were observed following both interventions. FIQ scores decreased at 24 h after both RT and Pilates sessions (RT: 52.21 ± 18.61; Pilates: 45.50 ± 18.63; p = 0.038, η²p = 0.42, 95% CI [−12.5, −1.2]). Conclusions: Both Resistance Training and Pilates acutely reduced overall disease impact in individuals with fibromyalgia, with Pilates promoting superior acute gains in posterior chain flexibility. Full article

Durability deterioration and interlayer bonding failure of ultra-thin overlays remain critical challenges under coupled environmental and mechanical actions. Although environmental damage to asphalt mixtures has been widely investigated, the relationship between pore-structure evolution and interlayer fatigue deterioration in polymer-composite-modified ultra-thin overlays incorporating styrene–butadiene–styrene (SBS) and micro carbon fiber (MCF) remains insufficiently understood. This study therefore extends existing research by clarifying this relationship under freeze–thaw cycling and water immersion. Three-point bending and direct shear fatigue tests were conducted to evaluate bending and interlayer shear fatigue performance, respectively, while nanoindentation and X-ray computed tomography (CT) were used to characterize micromechanical properties and three-dimensional pore-structure evolution. The results showed that five freeze–thaw cycles reduced the bending fatigue life by 75.3% and the interlayer shear fatigue life by 49.6%, while six days of water immersion reduced the interlayer shear fatigue life by 55.1%. Freeze–thaw cycling promoted open-pore and pore-throat development and increased total porosity by 23.9%, contributing to aggregate displacement and redistribution of the internal skeleton. In contrast, immersion increased the proportion of small and closed pores, while isolated pores concentrated near the interlayer weakened interlayer shear resistance. Although immersion caused greater reductions in hardness and modulus, freeze–thaw-induced pore development was associated with greater deterioration in bending fatigue performance. Furthermore, an adaptive-network-based fuzzy inference system (ANFIS) was developed to predict pore tortuosity from equivalent diameter, shape factor, and porosity, with testing errors ranging from 0.102 to 0.129 for untreated, freeze–thaw, and immersed specimens. An exponential relationship was further identified between tortuosity and the pore comprehensive effect index (PCEI), providing a quantitative approach for characterizing pore connectivity and evaluating environmental deterioration in polymer-composite-modified asphalt concrete. Full article

Background: Post-surgical breast cancer (BC) survivors frequently experience clusters of persistent post-treatment physical and psychological symptoms, which can negatively affect their quality of life (QoL). Mind–body interventions such as Qigong may offer potential benefit, but evidence in oncology remains limited. Methods: We conducted a single-arm pilot feasibility study at the AMICO clinic (IRCCS-CROB, Southern Italy) to evaluate the feasibility, acceptability, safety, and exploratory pre–post symptoms associated with an 8-week Qigong programme in post-surgical BC patients. Fourteen women (aged 42–73 years; stage I–III) who reported symptom burden and emotional sensitivity attended weekly one-hour classes and were encouraged to practise at home. Feasibility outcomes included adherence, completion of post-intervention assessment, adverse events, and participant acceptability. Symptom severity was assessed at baseline and post-intervention using a 0–5 study-specific symptom questionnaire score. For the secondary descriptive prevalence analysis, scores ≥ 3 were classified as indicating moderate-to-severe symptom burden. Results: All 14 participants completed the post-intervention assessment, overall intervention adherence was 92%, and no adverse events were reported. In the secondary descriptive analysis, the prevalence of moderate-to-severe pain and mood changes decreased from 64.3% to 35.7%, fatigue from 57.1% to 28.6%, anxiety from 85.7% to 42.9%, and sleep disturbances from 35.7% to 14.3%. Hot flushes decreased from 64.3% to 42.9%. Despite the heterogeneity of individual symptom trajectories, most participants reported meaningful improvements in overall well-being. Conclusions: The 8-week programme was feasible, well tolerated, and acceptable in this small real-world cohort. Symptom burden decreased during the intervention period; however, because of the uncontrolled study design and small sample size, these changes cannot be attributed specifically to Qigong. Larger controlled studies are required to estimate treatment effects and identify potential moderators of response. Full article

Rheumatoid arthritis (RA) is a chronic autoimmune disease in which fatigue and sleep disturbances, in addition to articular symptoms, are of significant importance. These symptoms are among the most common and burdensome complaints reported by patients; they affect their daily functioning and quality of life, and can also exacerbate one another. Currently, the treatment of RA focuses not only on reducing inflammatory activity and preventing structural damage, but also on improving outcomes that matter most to patients. In modern RA treatment, Janus kinase inhibitors (JAKis) are becoming increasingly important; by inhibiting the JAK/STAT pathway, they limit the activity of cytokines involved in the inflammatory response. This review aimed to analyse the effect of selected JAKis on fatigue and sleep quality in patients with RA. An analysis of available study results showed that baricitinib, filgotinib, tofacitinib and upadacitinib reduce fatigue severity. In many cases, improvement was observed as early as the initial stages of treatment and persisted at later follow-up points. At the same time, the extent of this improvement was not uniform and depended on the drug used, the dose, the patient population, and the assessment method adopted. Some analyses also suggested that this effect may have been partly due to reduced pain and improved disease activity. The data on sleep quality are less extensive, but the results suggest that tofacitinib and upadacitinib may also have a beneficial effect in this regard. With tofacitinib, improvements in sleep quality were observed early, affected multiple sleep domains, and, in some studies, persisted over the long term. For upadacitinib, an improvement in sleep quality appeared to be associated with disease control and remission. The smaller number of studies on sleep quality than on fatigue highlights the need to consider this parameter more thoroughly when assessing the efficacy of JAKi treatment and emphasises the importance of a more holistic approach in clinical practice. Full article

Machine learning (ML) provides new opportunities to model the nonlinear relationships among composition, processing, microstructure, defects, properties, and in-service degradation of structural steels. This structured critical review examines ML applications to materials and process design, microstructural characterization, mechanical-property prediction, corrosion, fire and elevated-temperature performance, fatigue, fracture, and remaining-life assessment. Literature published up to 31 July 2026 was searched primarily through the Web of Science Core Collection and Scopus. A total of 110 publications were retained based on their relevance to structural steels, transparency of data and modeling procedures, and availability of information on validation or engineering applicability. The reviewed studies show that model suitability depends strongly on data modality, sample independence, feature representation, and validation strategy rather than on algorithm family alone. ML has progressed from property prediction toward process optimization, inverse materials design, environmental degradation assessment, and fatigue- and crack-related prognostics. However, independent cross-manufacturer, cross-laboratory, production-scale, and field validation remains limited, while uncertainty quantification and applicability-domain assessment are still inconsistently reported. These limitations are particularly important for corrosion, fire, fatigue, and remaining-life applications, where internally validated models should not be interpreted as substitutes for established physical models or design provisions. Future research should prioritize standardized multimodal data, physics-informed and uncertainty-aware modeling, prospective validation, and rigorously evaluated closed-loop monitoring and digital-twin frameworks for structural-steel life-cycle management. Full article

Blood transfusion near the end of life for patients with cancer may relieve symptoms attributed to anaemia or control bleeding, but its palliative value depends on whether benefit occurs within the patient’s expected survival and outweighs the clinical and practical burden of treatment. This structured narrative review examines evidence concerning red-cell and platelet transfusion, transfusion-sparing patient blood management, hospice access and alternative delivery models in adults receiving palliative or end-of-life care. Structured searches of MEDLINE, Embase, Scopus and the Cochrane Library identified original studies, audits, qualitative research and relevant evidence syntheses. The evidence was predominantly observational and methodologically heterogeneous. Reported symptomatic response rates after red-cell transfusion ranged from 31% to 70%, most commonly involving short-term improvement in fatigue, dyspnoea or general well-being. Benefit often diminished within 14 days, while 23–35% of participants in historical cohorts died within two weeks, limiting the opportunity to experience benefit. Response was not reliably predicted by haemoglobin concentration. Red-cell transfusions were frequently guided by laboratory values, administered late in the disease course and not followed by systematic reassessment. Evidence concerning platelet transfusion remains largely descriptive and does not establish a prophylactic threshold for end-of-life care. Intravenous iron and haemostatic radiotherapy may reduce transfusion requirements in selected patients, although their applicability depends on clinical stability, the source of bleeding and sufficient time to benefit. In haematological malignancies, transfusion dependence has been associated with lower hospice enrolment and shorter hospice stays, whereas home- and hospice-based transfusion may reduce travel and waiting burdens for appropriately selected patients. Transfusion near the end of life should therefore be considered a goal-concordant, time-limited trial. A patient-valued outcome should be defined beforehand, the fewest units likely to achieve that outcome should be administered, and benefit should be reassessed using the same measure. Further transfusion should be offered only when documented symptomatic or functional benefit outweighs adverse effects and treatment burden for the individual patient. Full article

Electric-shovel top sheave bearings with sensor-embedded slots operate under harsh service loads, making them prone to fatigue crack initiation and propagation. Accurate predictions of crack growth within the bearing body are therefore essential for intelligent bearing design and reliability assessments because the bearing integrity directly affects shovel service life and safety. This paper presents a sub-modeling-based method that embeds initial cracks while preserving actual roller-ring boundary conditions and ensuring computational efficiency via adaptive mesh refinement. A global model first identifies critical crack-prone zones, after which the sub-model systematically examines the effects of the initial crack angle and sensor-embedded slot depth on the propagation behavior. The results indicate that both factors significantly increased the stress intensity factor (SIF). Among the evaluated designs, the 15 mm -deep slot produced the highest SIFs and the shortest predicted crack-propagation life, indicating that slot depth was a key design parameter under the investigated conditions. The findings provide theoretical support for the structural design and fatigue evaluation of intelligent electric-shovel top sheave bearings. Full article

This study investigates the effect of Arundodonax L.-derived lignin on the rheological behaviour, mechanical performance and oxidative ageing resistance of bitumen. Arundo donax is a fast-growing invasive grass with high lignin content, representing a promising sustainable biomass source for bitumen modification. Lignin was extracted via the Acid Detergent Lignin method, yielding a fine powder (50–300 μm). The incorporation of 6 wt% lignin into a 35/50 paving-grade bitumen induced significant changes in binder behaviour. Infrared spectroscopy (FTIR) confirmed the polyaromatic and oxygenated nature of lignin and indicated that its interaction with bitumen is primarily physical, involving polar intermolecular interactions rather than chemical bonding. Lignin modification significantly increased stiffness, elasticity, and rutting resistance, as evidenced by higher softening point, complex modulus, and recovery after creep loading. Furthermore, FTIR analysis confirmed a reduced susceptibility to oxidative ageing, demonstrated by lower increases in carbonyl and sulfoxide indexes after ageing. This suggests distinct antioxidant activity associated with the phenolic structures of lignin. Despite these benefits, severe long-term ageing led to a marked reduction in fatigue life, ductility, low-temperature cracking resistance, and adhesive properties. Overall, these results demonstrate that Arundo donax-derived lignin is a promising sustainable modifier for bitumen, though optimisation of the dosage and blending conditions is necessary to balance durability against long-term fracture performance. Full article

High-frequency induction hardening enhances the surface wear resistance and contact fatigue life of high-speed linear guides, but simultaneously produces an inhomogeneous, layered cross-sectional structure comprising a high-strength, low-ductility outer hardened layer and a low-strength, high-ductility inner core. This structural heterogeneity renders conventional straightening stroke prediction models—predicated on homogeneous material assumptions—fundamentally inadequate. Moreover, the iterative trial-bending operations ubiquitous in industrial practice progressively accumulate plastic strain, causing guide rails to exhibit erratic positive-to-negative deflection reversal during sequential straightening passes. To address these critical challenges, this study proposes a novel two-stage hybrid straightening strategy based on inverse finite element analysis (FEA) and closed-loop experimental feedback. An equivalent hardened layer depth (HD₀) is introduced as a parametric descriptor to construct a layered elastoplastic finite element model, and an inverse simulation strategy is developed to generate a comprehensive three-dimensional stroke–residual deflection prediction dataset encompassing both vertical and lateral straightening conditions across multiple support spans. Displacement-controlled three-point bending experiments validate the layered model and elucidate the mechanism by which cumulative plasticity progressively amplifies cross-sectional plastic sensitivity under repeated loading. Grounded in this physical insight, a hybrid straightening algorithm is formulated, combining dataset-driven initial stroke prediction for rapid large-deformation elimination with an upper-bound constraint and a measurement-feedback-driven sequential reduction compensation scheme for fine-tuning. Comparative experiments demonstrate that the proposed strategy effectively suppresses the oscillatory over-straightening characteristic of conventional empirical trial-and-error approaches, consistently reducing residual deflection below 0.05 mm within two to three loading cycles. This work bridges the gap between theoretical simulation and the complex physical state of actual machining, substantially improving both the efficiency and precision of straightening for guide rails with induction-hardened layers. Full article

In recent years, premature fatigue issues in heavy-duty steel crane girders have occurred frequently, underscoring an urgent need to establish targeted life extension methods. Compared with post-crack repair after macroscopic fatigue cracks have appeared, it is more practical to delay or even prevent the formation of such cracks in fatigue-sensitive zones of the crane girder. Extensive research has demonstrated that bonding Carbon Fiber-Reinforced Polymer (CFRP) plates can significantly enhance the fatigue life of defective components. However, most existing studies focus on thin plates with pre-existing macroscopic cracks, with limited attention given to scenarios involving thick plates or intervention before crack initiation. Therefore, this study focuses on the fatigue problem around bolt holes in the lower flange of heavy-duty steel crane girders. It investigates the life extension method of bonding CFRP plates prior to macroscopic crack formation. Through finite element analysis and comparative fatigue tests, the fatigue life enhancement mechanism was preliminarily interpreted. The effectiveness of this method is validated, and a practical CFRP bonding strategy is proposed to significantly improve the fatigue life of the lower flange in heavy-duty steel crane girders. Full article

The application of two-dimensional molybdenum disulfide (MoS₂) in asphalt binder modification is limited by its inherent chemical inertness and severe agglomeration. In this study, four surface-functionalization strategies, including (3-aminopropyl)triethoxysilane (APTES) silanization, polydopamine (PDA) coating, tannic acid (TA)–APTES co-deposition, and PDA–APTES hybrid modification, were used to improve the dispersion and compatibility of MoS₂ nanosheets in styrene–butadiene–styrene (SBS)-modified asphalt binders. Scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffraction (XRD) results indicated that surface functionalization introduced organic functional groups, reduced nanosheet restacking, and preserved the intrinsic 2H-MoS₂ crystal structure. Binder-level rheological tests and thermogravimetry–differential scanning calorimetry (TG–DSC) analysis showed that surface-functionalized MoS₂ improved the high-temperature deformation resistance, creep recovery, fatigue resistance, low-temperature relaxation capacity, and thermal stability of SBS-modified asphalt. Among the investigated binders, PDA–APTES-functionalized MoS₂/SBS-modified asphalt exhibited the most balanced performance. At 3.2 kPa, its recovery rate reached 79.5%, while its non-recoverable creep compliance decreased to 0.105 kPa⁻¹. Its fatigue life at 15% strain increased by 76.8% compared with SBS-modified asphalt, and its creep stiffness at −24 °C decreased to 222 MPa. Mechanistic interpretation suggests that the PDA–APTES hybrid layer may act as an organic–inorganic interfacial transition region, improving MoS₂ dispersion and compatibility with the SBS–asphalt phase and facilitating more effective integration of the nanosheets into the composite structure. These results indicate that PDA–APTES-functionalized MoS₂ nanosheets are promising interfacial modifiers for improving the rheological and thermal performance of SBS-modified asphalt binders. Full article