Search Results (375)

To investigate the rheological properties and compositional changes in SBS-modified bitumen under different aging conditions in the unique environmental conditions of the Xinjiang region, this study selected a local 70# base bitumen from Xinjiang and prepared modified bitumen by adding 4.0%, 4.5%, and 5.0% SBS modifier, respectively. RTFOT and PAV were used to simulate the short-term thermal-oxidative aging and long-term oxidative pressure aging processes of the bitumen samples, respectively. The three key indicators and dynamic rheological properties of the bitumen were tested for the original sample, as well as before and after short-term thermal-oxidative aging and long-term oxidative pressure aging. Thin-layer chromatography/flame ionization detection (TLC/FID) was used to analyze the migration patterns of the samples’ chemical components, and a random forest model was employed to establish a quantitative mapping between the four components of the modified bitumen and the rutting factor over a wide temperature range. The results indicate that aging weakens the improvement effect of SBS on the high-temperature performance of bitumen. However, 4.5% SBS-modified bitumen subjected to long-term oxidative pressure aging still maintains the best high- and low-temperature performance, elastic recovery capacity, and fatigue resistance compared to other dosage levels. It also has the highest bitumen content, which verifies the high-temperature performance of this dosage at the component level. Therefore, the optimal SBS dosage is recommended to be 4.5%. Notably, as the SBS content increases, it significantly regulates the increase in heavy fraction content during the aging process, while the decrease in light fraction content is not significantly affected by the content. Based on the random forest algorithm, a mapping relationship between fractions and properties under fully aged conditions was established. This study provides a theoretical basis for research on the modification and aging mechanisms of Xinjiang bitumen. Full article

The degradation of styrene-butadiene-styrene (SBS) modified asphalt under thermal-oxidative aging can reduce pavement service life. Lignin is a renewable material with active phenolic hydroxyl groups. Incorporating lignin into SBS modified asphalt may provide a potential bio-based auxiliary modification route. To investigate the antioxidative effect and rheological properties of SBS modified asphalt after adding lignin, a molecular dynamics test and experimental tests were employed. The molecular simulation results suggested that lignin preferentially associated with asphaltene and resin molecules and changed the molecular mobility of asphalt components in a component-dependent manner. The SBS/lignin composite modified asphalt was evaluated by temperature sweep (TS), Multiple Stress Creep and Recovery (MSCR), Linear Amplitude Sweep (LAS) and Fourier transform infrared spectroscopy (FTIR). Rheological tests showed that lignin increased the complex shear modulus and rutting factor. LAS results showed that lignin reduced the fatigue life of SBS-modified asphalt in the unaged state due to increased stiffness and embrittlement. However, after long-term aging, the lignin-containing binders retained higher fatigue resistance than the SBS-only control, which may be related to the slower evolution of oxidation-related functional groups and SBS-related spectral indices. FTIR analysis provided semi-quantitative evidence that lignin addition reduced the growth of sulfoxide-related bands and helped maintain the polybutadiene-related index during aging. Overall, lignin may serve as a potential auxiliary antioxidant modifier for SBS modified asphalt, while its exact source-specific molecular mechanism requires further verification. Full article

Background: Velocity loss (VL) is widely used in velocity-based training (VBT) to index mechanical fatigue, yet attentional focus cues may alter velocity profiles and their relationship with internal load. This study tested whether internal focus, external focus, or control modifies repetition-level velocity, lactate kinetics, and lactate–VL% coupling during bench press (BP) at 60% one-repetition maximum (1RM). Methods: Thirty-six trained men were randomized into three groups. Thirty-four participants completed the study and were included in the final analyses according to outcome-specific data availability. Participants completed two counterbalanced sessions on a Smith machine BP: (i) a single set to technical failure, and (ii) a conventional 3 sets × 10 repetitions at 60% 1RM. Concentric velocity was recorded via a linear position transducer and analyzed at the repetition level using linear mixed-effects models. Lactate was analyzed via Gaussian generalized estimating equations (GEEs). Results: Repetitions to failure and terminal velocity at failure did not differ between groups (Welch p = 0.328; ω² = 0.045). During 3 sets × 10 repetitions, velocity decreased across sets and repetitions (both p < 0.001); adding group terms improved fit (LR χ²(12) = 42.26, p < 0.001), with additional improvement for group-dependent fatigue patterns (LR χ²(6) = 14.90, p = 0.021). Lactate increased over time (Wald χ²(4) = 244.56, p < 0.001) with convergence by post-lactate set 3 and post-lactate 30 s. Lactate–VL% coupling was strongly moderated by group (post-lactate × group: χ²(2) = 80.42, p < 0.001), with slopes (ΔVL% per 1 mmol·L⁻¹) of 5.27 (internal focus), 13.60 (external focus), and 0.04 (control). After Holm correction across prespecified primary outcomes, only the post-session rating of perceived exertion differed (pHolm = 0.004; ω² = 0.045), with higher values in the external focus group. Pairwise effects were calculated as comparator minus external focus; therefore, negative g values indicate a higher rate of perceived exertion (RPE) in the external focus group (gHedges ≈ −1.50 vs. control; −1.37 vs. internal focus). Conclusions: Attentional cueing did not consistently alter averaged VL% outcomes after multiplicity correction, but it was associated with differences in early lactate kinetics and modified the observed association between post-set lactate and VL% in the interaction-based coupling model. Cueing scripts should therefore be reported verbatim and standardized in VBT studies, particularly when VL-derived indices are interpreted alongside internal load markers. Full article

As floating offshore wind turbines (FOWTs) scale towards 10 MW+ capacities, suppressing wave-induced rotational resonance becomes critical for system survivability. This study introduces an optimized, highly symmetrical four-float semi-submersible platform, explicitly tailored to support the DTU 10 MW wind turbine and paired with an orthogonal four-point mooring system. Using three-dimensional linear potential flow theory via ANSYS AQWA, comprehensive frequency- and time-domain hydrodynamic evaluations were conducted. To address the inherent limitations of inviscid potential flow assumptions, an empirical added-damping method was implemented. Quantitative results demonstrate a drastic reduction in motion responses: the peak Response Amplitude Operator (RAO) for heave decreased by 68.6% (from 1.945 m/m to 0.610 m/m). Most notably, the peak RAOs for the critical rotational degrees of freedom—pitch and roll—were reduced by over 92% (from 2.080 °/m and 2.216 °/m to ~0.168 °/m, respectively). Ultimately, compared to traditional asymmetric three-float concepts, this novel symmetric omnidirectional layout provides a more uniform restoring stiffness. The resulting suppression of pitch and roll resonance results in a profound reduction in tower-base bending moments and gyroscopic loads, thereby significantly enhancing the dynamic stability, safety margins, and fatigue life of the 10 MW FOWT under extreme survival sea states. Full article

Background and Objectives: Poor sleep is common in community and primary-care settings, yet very brief sleep measures suitable for routine use remain limited. We developed and evaluated the five-item Promoting Evaluation and Awareness of Comfort in Sleep (PEACE) scale and examined its associations with well-being and fatigue. Materials and Methods: In a cross-sectional, clinician-mediated online survey, 312 community-dwelling adults in Italy who were not receiving active treatment for major diseases completed PEACE, the World Health Organization-Five Well-Being Index (WHO-5), and a short fatigue questionnaire. The sample was stratified and split into exploratory and confirmatory subsamples for factor analyses. Results: Factor analyses supported the use of a single total score and showed acceptable reliability. Results were broadly similar in women and men, with no evidence of item-level bias, although some model-comparison indices were mixed. Higher PEACE scores were associated with better well-being and lower fatigue. Adding PEACE to a model predicting well-being from body mass index and sex increased explained variance from 4.0% to 11.5%. Conclusions: PEACE is a brief sleep-quality measure with promising initial psychometric properties. In this sample, it was associated with well-being and fatigue and may add information beyond body mass index and sex in community and primary-care settings. Full article

Waste sweet potato vine fiber (WSVF) effectively extends asphalt service life by enhancing cracking resistance in gel-like base asphalt matrices, yet its crack-resistant mechanism lacks mechanical characterization. This study proposes an analytical method for evaluating WSVF-modified asphalt’s crack-resistant behavior based on the principle of mechanical energy balance. First, alkali-treated WSVF with a mass fraction of 1% was added into 70# gel-like base asphalt to prepare WSVF-modified asphalt. Lignin fiber (LF)-modified asphalt and 70# gel-like base asphalt were selected as control groups, and three types of time sweep and scanning electron microscopy tests were conducted. Then, the three-dimensional cracking volume model and damage kinetics model were established for analyzing the cracking response behavior, defining the asphalt damage variable and determining the cracking damage activation energy (E_acd). Finally, the E_acd was used to quantify the difficulty of the cracking damage process for the WSVF-modified asphalt. The reinforcement and cracking resistance mechanisms of WSVF in asphalt were analyzed by the E_acd and asphalt microstructure. The results show that the cracking volume response of WSVF-modified asphalt under cyclic loading presents three-stage nonlinear behaviors. The established fatigue damage kinetics model can accurately describe the fatigue damage evolution process of alkali-treated WSVF-modified asphalt. The E_acd values of WSVF-modified asphalt, LF-modified asphalt, and 70# gel-like base asphalt are 10.60 kJ·mol⁻¹, 21.83 kJ·mol⁻¹, and 29.74 kJ·mol⁻¹, respectively. After alkali treatment, the WSVF surface exhibits grooves, demonstrating superior adsorption and storage capacity for asphalt. The WSVF can cross link through the bonding effect of asphalt and form a three-dimensional network framework structure, which can significantly increase the E_acd and provide strengthening and toughening effects on gel-like base asphalt. In summary, E_acd values are used as a mechanical indicator to quantitatively evaluate the fatigue cracking resistance of WSVF-modified asphalt. Full article

Pilot fatigue, driven by irregular schedules and long duty hours, remains a major aviation concern. This study aims to minimize pilot fatigue and optimize crew scheduling through a mixed integer linear programming model, considering flight duration, rest periods, fatigue thresholds, and regulations. The optimized 7-day schedule minimized pilot fatigue, reflecting effective management and workload balance. Scenario analysis results showed that reducing rest hours was infeasible, while adding flights required more pilots. The results confirmed the model’s effectiveness in enhancing safety and ensuring balanced workloads, highlighting the need for adequate pilot resources under increasing operational demands. Full article

The safety-critical nature of aircraft landing gear has led to interest in Structural Health Monitoring (SHM) and Remaining Useful Life (RUL) methodologies for the fatigue substantiation of landing gear assemblies. Due to the engineering effort that can be required to implement such approaches, it is prudent to target SHM and RUL activities at specific aircraft fleets. This paper employs air traffic data in the form of Automatic Dependent Surveillance-Broadcast (ADS-B) data to characterise the occurrence and severity of ground turns performed across fleets of differing aircraft type, location and operator characteristics. From the evaluation of 3250 flights, it was observed at the fleet level that ground turn characteristics show limited sensitivity to the aircraft’s geographical location and operator characteristics, excluding cargo aircraft and those operated by Ultra-Low-Cost Carriers. However, assessment of individual aircraft highlighted that the occurrence rate of fatigue-critical pivot turns can exceed twice that of the remaining aircraft fleet, suggesting that SHM and RUL activities should be focused on aircraft that deviate significantly from the expected fleet-wide behaviour. Finally, this paper presents an initial investigation into inferring the Nose Wheel Steering angle provided from Quick Access Recorder flight data directly from ADS-B trajectories. Full article

The reuse of milled pavement material, known as RAP (Reclaimed Asphalt Pavement), represents one of the major current challenges in highway engineering worldwide. There is no doubt that the most valuable application of this residue is its use in the production of new hot asphalt mixtures, incorporating the highest possible RAP content, a process that requires adaptations in residue processing at asphalt plants. In Brazil, the RAP content added to these mixtures is limited to a maximum of 25%. Consequently, alternative applications have gained prominence in the country to increase RAP utilization in pavement engineering, such as its use in cold premixed asphalt mixtures. This study aimed to evaluate the performance of cold asphalt mixtures containing different RAP contents through mechanistic-empirical analyses of a reference pavement structure, using the modelling framework adopted in the Brazilian Asphalt Pavement Design Method (MeDiNa). After Marshall mix design and volumetric and mechanical characterization of mixtures containing 0%, 10%, 20%, 30%, and 40% RAP, stiffness and fatigue parameters were used to estimate the evolution of cracked area in the reference pavement, with each mixture applied as the surface layer under different traffic levels. The results demonstrated that pavement performance improved for all RAP contents evaluated compared to the mixture without RAP, with the mixture containing 30% RAP showing the best overall performance. Full article

Background: Restricted ankle dorsiflexion is common in basketball athletes and has been associated with altered lower-limb mechanics and reduced athletic performance. Although ankle joint mobilization is widely used to improve mobility, its effects on athletic performance remain unclear. The aim of this study was to examine whether adding posterior ankle joint mobilization to a structured exercise-based program incorporating eccentric strengthening and stretching improves ankle mobility and athletic performance in basketball athletes with restricted dorsiflexion. Primary outcomes were dorsiflexion range of motion (DF-ROM) and the Weight-Bearing Lunge Test (WBLT); secondary outcomes included jump performance, hop tests, Reactive Strength Index, Fatigue Index, and maximal isometric strength. Methods: In this randomized controlled trial, 38 basketball athletes (mean age 21.26 ± 2.52 years) with unilateral restricted ankle dorsiflexion were randomly allocated to an exercise-only group (n = 19) or to an exercise plus talocrural mobilization group (n = 19). The intervention lasted 5 weeks, with assessments performed at baseline, post-intervention, and at a 3-month follow-up. Results: Both groups improved ankle dorsiflexion; however, greater gains were observed in the intervention group for both dorsiflexion range of motion (DF-ROM; interaction p < 0.001; mean difference [MD] = 3.52° post-intervention and MD = 5.17° at follow-up) and the Weight-Bearing Lunge Test (WBLT; interaction p < 0.001; MD = 1.39 cm and MD = 1.34 cm, respectively). The intervention group showed superior improvements in countermovement jump and Triple Hop Test performance (both p < 0.001), as well as a small but statistically significant advantage in the Single Hop Test (p = 0.015). No between-group differences were found for the 6 m timed hop test, Reactive Strength Index, Fatigue Index, or maximal isometric strength (p > 0.05). Conclusions: Adding ankle joint mobilization to an eccentric strengthening and stretching program produced greater improvements in dorsiflexion and jump performance than exercise alone, without affecting speed, reactive ability, or maximal strength. Ankle mobilization may be a useful adjunct for improving functional mobility and selected performance outcomes in basketball athletes. Full article

Parkinson disease (PD) and mood disorders represent two substantial global health burdens that increasingly co-occur as both conditions rise in prevalence worldwide. Diagnosing Parkinson disease in patients with pre-existing mood disorders is clinically challenging due to overlapping symptoms, medication effects, and shared neurobiological mechanisms. Apathy, psychomotor slowing, and fatigue may mimic depressive symptoms, leading to delayed recognition of early parkinsonism. Development of an underlying neurodegenerative disorder could account for some treatment-resistant symptoms or treatment failures if not recognized. Therefore, the identification of PD will change the treatment and management plan significantly. Accurate diagnosis of PD requires a detailed neurologic examination focusing on bradykinesia, rigidity, and resting tremor, supported when appropriate by dopamine transporter imaging (DaT scan) or other emerging biomarkers. Understanding the temporal relationship between psychiatric and motor features helps differentiate prodromal PD from primary mood disorders. Management of patients with both mood disorders and PD integrates dopaminergic replacement therapy for motor symptoms with individualized treatment of psychiatric comorbidities. Levodopa remains the cornerstone for motor control, while dopamine agonists, MAO-B inhibitors, and COMT inhibitors can be added as needed. For depression and anxiety, SSRIs and SNRIs are first-line choices; quetiapine or clozapine are preferred when treatment for psychosis is necessary. Intentional, thoughtful polypharmacy is frequently required. Non-pharmacologic interventions—including cognitive behavioral therapy, structured exercise, and patient–caregiver education—enhance mood, function, and quality of life. Multidisciplinary collaboration between neurology, psychiatry, and allied health professionals is essential for optimal outcomes. This review offers guidance to healthcare providers as well as other interested parties involved in patients with mood disorders who may also be developing or have PD, especially to those who may have limited access to neurologic resources. Full article

Background: Flexible surgical instruments for Robot-Assisted Minimally Invasive Surgery (RAMIS) face a critical limitation: the inability to rotate the distal head while the instrument is in a bent configuration, which restricts the maneuverability in narrow surgical workspaces. Methods: This paper presents a novel 4-degree-of-freedom (DOF) flexible laparoscopic instrument with a 10 mm diameter, incorporating a 3D-printed flexible element. The design enables independent bending (0–90°), continuous distal head rotation (360°), gripper actuation (0–60°), and rod rotation (180°). A constant-curvature kinematic model was developed. The instrument was manufactured using PolyJet 3D printing technology and integrated with the ATHENA parallel robot for proof-of-concept experimental validation. Results: Experimental tests demonstrated successful independent 360° distal head rotation across the full bending range (0–90°), validated through simulated surgical procedures including stomach retraction. Quantitative characterization using optical motion capture revealed a maximum angular deflection of 79.85° at 670 g applied load, with tip displacements of 74.95 mm (X) and 91.18 mm (Y). The measured grasping force was approximately 2 N, tip position repeatability was ±2.86 mm, and fatigue testing demonstrated no degradation after 500 bending cycles, confirmed by digital microscope inspection. The instrument performed multiple manipulation tasks, including elastic band transfer, wire path navigation, spring manipulation, and tissue grasping. Conclusions: The proposed instrument addresses a significant white spot in surgical robotics by adding an additional functional capability enabling grasper reorientation without repositioning the entire instrument. Full article

Natural fibers have attracted increasing attention as eco-friendly and sustainable additives for improving the durability and mechanical performance of asphalt mixes. This paper presents a critical state-of-the-art review of the use of six kinds of natural fibers in asphalt mixes. This paper reviews the impact of six natural fibers such as lignin fiber, bamboo fiber, bagasse fiber, corn stalk fiber, basalt fiber, and wool fiber on the properties of bitumen binders and mixes. It examines the influence of these fibers on the physical properties, rheological properties, and fatigue performance of bitumen binders. In addition, the influence of fibers on the moisture stability, anti-cracking, and high- and low-temperature performance of asphalt concrete was analyzed. The review demonstrated that the recommended lengths of natural fibers in asphalt mixes are as follows: lignin fiber 0.8–1.2 mm, bamboo fiber 4–20 mm, sugarcane bagasse fiber 5–12 mm, corn stalk fiber 3 mm, and basalt fiber 6–30 mm. Adding lignin fiber and corn stalk fiber enhanced the high-temperature characteristic of bitumen. The high- and low-temperature properties of the binder were improved by adding bamboo fiber. The addition of basalt fiber and bamboo fiber can increase rutting resistance and fatigue life. Additionally, incorporating the bamboo fiber, bagasse fiber, basalt fiber and wool fiber improved the low-temperature cracking and fatigue resistance of the bitumen mixture. The high-temperature properties of the bitumen mixes were enhanced by using basalt fibers, lignin fibers, bamboo fibers and bagasse fibers. The moisture resistance of bitumen mixes were reinforced by the incorporation of basalt fibers, lignin fibers and bamboo fibers. In general, incorporating natural fibers provided a technical method for improving the performance of asphalt concrete in road applications. Full article

To explore the potential of phosphogypsum for resource utilization in asphalt pavements, this study evaluated its feasibility as a warm-mix asphalt (WMA) additive and investigated its influence on the rheological properties of asphalt binder. Phosphogypsum warm-mix asphalt was prepared by incorporating varying dosages of phosphogypsum warm-mix additive (PGWA) into both base asphalt and styrene–butadiene–styrene (SBS)-modified asphalt. The high-, medium-, and low-temperature performance of phosphogypsum warm-mix asphalt was evaluated using rheological tests. The results revealed that the complex modulus of PGWA-added base asphalt was higher than that of the base asphalt, with only minor changes in phase angle. The incorporation of the SBS modifier significantly enhanced the stiffness and elasticity of the asphalt binder. Compared with the control asphalt, PGWA-added asphalt exhibited lower creep strain and accumulated strain, higher creep recovery rates, and smaller non-recoverable compliance under the same stress level, indicating an improved resistance to high-temperature permanent deformation. PGWA increased the cumulative damage capacity and extended the fatigue life of the asphalt binder. Although the PGWA slightly reduced the low-temperature performance, the SBS modifier effectively compensated for this drawback. The Burgers model accurately captured the low-temperature rheological behavior of PGWA-added asphalt. Overall, PGWA-added asphalt demonstrated excellent rheological performance and high application potential, offering a promising pathway for the resource utilization of phosphogypsum and the development of sustainable, eco-friendly pavement materials. Full article

Cordyceps militaris is an important medicinal and edible fungus that contains a wide range of bioactive ingredients, including cordycepin, polysaccharides, ergosterol, mannitol, proteins, and carotenoids, which collectively confer tonic, anti-fatigue, immunopotentiating, antioxidant, anti-inflammatory, and metabolic-regulating properties. Notably, the culture residue of C. militaris, which remains rich in bioactive compounds, is mostly discarded during production, resulting in resource waste and potential environmental pollution. In this study, C. militaris culture residue extract (CME) was prepared by ultrasonic extraction, and its antiviral activity was evaluated using Nicotiana benthamiana via foliar spraying. The results showed that CME treatment significantly upregulated the expression of defense-related genes PR1, PR2, and ICS1, with PR1 showing the most pronounced induction (13.20-fold before and 11.89-fold after TMV inoculation), thereby conferring strong antiviral activity. In addition, root irrigation with 10 mg/mL CME significantly increased plant height, stem diameter, dry weight, fresh weight, chlorophyll content, and carotenoid content in tomato plants. Taken together, these findings indicate that CME functions as a plant immune inducer capable of effectively suppressing tobacco viral diseases while promoting plant growth. This study not only provides a new strategy for the value-added reutilization of C. militaris culture residues but also offers a scientific basis for the green control of tobacco mosaic disease. Full article