Search Results (2,525)

Long-distance belt conveyors exhibit significant nonlinear dynamic characteristics due to factors such as the viscoelasticity of the conveyor belt, startup curves, and material loading, which lead to substantial variations in component loads and belt tension. This complexity poses challenges for dynamic analysis and the study of dynamic properties. Based on the Kelvin–Voigt viscoelastic constitutive relation, this paper establishes a discrete model of the conveyor belt and further develops a nonlinear dynamic model for long-distance belt conveyors. The model is numerically solved using the fourth-order Runge–Kutta method. On this basis, the influence of key parameters—such as integration step size, startup curve, operating time, and belt speed—on the dynamic behavior of the belt conveyor is investigated. The results indicate that increasing the counterweight mass effectively suppresses oscillation in the tensioning device and enhances system stability. Prolonging the startup duration and optimizing belt speed also mitigate load impacts. Compared with conventional methods, a composite transitional startup strategy is proposed, which significantly reduces transient tension peaks in the conveyor belt. This study provides a theoretical basis for optimizing control strategies and structural design of long-distance belt conveyors, thereby improving operational safety and reliability. Full article

Strong magnetic fields and anisotropic stresses can substantially modify the structure and observable properties of compact stars. In this review, we present a unified treatment of magnetically induced anisotropy across neutron stars, hybrid stars, and white dwarfs, connecting the microphysical equation of state effects to macroscopic structure and multimessenger observables. We demonstrate that magnetic-field geometry plays a decisive role: toroidally oriented (transverse) fields enhance the maximum mass by providing additional perpendicular pressure support, whereas radially oriented fields primarily increase central compression with comparatively small mass gain. In neutron stars, anisotropy and magnetic stresses can shift phase-transition thresholds in hybrid models and enable configurations in the lower mass gap with significantly smaller magnetic energy compared to the gravitational binding energy. We further show that continuous gravitational wave emission from magnetically deformed neutron stars provides a complementary probe of internal field geometry through ellipticity-driven strain evolution. In magnetized white dwarfs, super-Chandrasekhar masses arise from the spatial redistribution of magnetic stresses rather than from globally strong magnetic energy. Taken together, these results highlight that magnetic-field geometry and matter anisotropy are as important as field strength in determining mass–radius relations, tidal deformability, gravitational wave detectability, and the emergence of extreme compact-star configurations. Full article

To address the neglect of real-time mass transfer effects by traditional analysis methods during the side-by-side offloading process of Floating Production Storage and Offloading (FPSO) and shuttle tankers, a numerical model incorporating the variable mass effect is established to enable the simulation of dynamic offloading processes. Using this model, the dynamic response characteristics under different offloading rates and sea conditions are systematically investigated and validated against towing tank tests. Based on the previously optimized benchmark configuration, which includes 16 side-by-side mooring lines, six floating fenders, and an anchor line angle of 60° for the FPSO, the evolution laws of mooring line tension and fender pressure under different offloading rates were systematically investigated under normal and extreme sea conditions. The results show that an increase in offloading rate significantly amplifies the system’s fender load; when the offloading rate reaches approximately 1.4 t/s, the system transitions from the quasi-static response region to a significant nonlinear coupling region, demonstrating obvious sea condition–rate coupling characteristics. Under the combined action of high offloading rates and severe sea conditions, fender pressure rapidly approaches the design limit, becoming the primary safety bottleneck for the system. Model test results indicate that the numerical model can well predict mechanical responses under low and medium offloading rate conditions. The research results can provide a reference for offloading rate control, safety assessment, and operational window determination during FPSO side-by-side dynamic offloading operations. Full article

Reference-driven humanoid motion tracking aims to reproduce a source motion on a target humanoid while preserving physical executability under actuation limits and changing contact conditions. The problem becomes particularly challenging for dynamic motions involving rapid support transitions, landing impacts, mixed hand–foot contacts, and moderate topology-preserving morphology variation. Existing pipelines often rely heavily on morphology-specific world-frame targets or treat balance and contact quality only indirectly during execution, which limits their reliability under dynamic contact variation. This paper presents a task and cost formulation for reference-driven humanoid tracking within the residual-based MuJoCo model predictive control (MPC) framework. The source motion is decomposed into a pelvis-centered canonical local reference, pelvis height and tilt references, and a pelvis-derived horizontal center-of-mass (CoM) velocity intent, and is tracked online with a zero moment point (ZMP)-aware contact-conditioned residual design including slip, penetration, posture, and control regularization. The formulation is compatible with standard MuJoCo MPC planners, and the evaluation is conducted under a shared iterative linear quadratic Gaussian (iLQG) setting on nominal and morphology-varied humanoids against tracking-only and two-stage inverse-kinematics (IK)-based baselines. The proposed formulation improves success rate, support quality, slip reduction, and progression accuracy, with the clearest gains on contact-sensitive motions; for example, success rate increases from 56.7% to 76.7% on Jump–Turn and from 46.7% to 70.0% on Cartwheel relative to the tracking-only MPC baseline. These results support the use of execution-oriented reference representation and contact-conditioned residual design for physically reliable reference-driven humanoid tracking. Full article

The global transition toward carbon-neutral energy solutions has established Solid Oxide Fuel Cells (SOFCs) as a key technology for next-generation power generation. This work presents a comprehensive numerical study and multi-factor statistical analysis of an anode-supported SOFC fueled by synthetic diesel. A three-dimensional computational fluid dynamics model, validated against experimental data, was integrated with a Taguchi L₂₇ orthogonal array to systematically evaluate the influence of six key parameters: temperature, fuel mass flow rate, operating pressure, current load, flow channel configuration, and methane molar fraction. Statistical analysis through the signal-to-noise ratio and analysis of variance identified the operating current as the most significant factor affecting cell voltage, followed by the fuel mass flow rate and temperature. The experiments showed that the highest levels of all factors (except for the current, which had the lowest level) maximize electrochemical performance while maintaining a steam-to-carbon ratio (S/C) within a range of 0.83 to 0.92, calculated based on total carbon content, ensuring sufficient humidification for internal reforming across all tested fuel compositions. Furthermore, a multiple linear regression model was developed as a computationally efficient surrogate, demonstrating exceptional predictive accuracy with an R² of 0.9954 and a mean relative error of 1.76% across independent validation cases. These results provide a robust methodology for rapid design and sensitivity analysis of internal-reforming SOFCs, offering a precise tool for optimizing fuel utilization in high-temperature electrochemical systems. Full article

The transition toward a sustainable agri-food system, aligned with agricultural and environmental policy objectives, has increased interest in aromatic plants as non-synthetic pesticide alternatives. This study focused on evaluating the antifungal potential of five specific aromatic plant species, particularly Lavandula dentata, Origanum vulgare, Thymus vulgaris, Salvia officinalis and Rosmarinus officinalis, against the phytopathogenic soil-borne fungi Fusarium oxysporum f.sp. radicis-lycopersici and Verticillium dahliae. During screening, L. dentata and T. vulgaris extracts exhibited strong in vitro fungicidal activity. Bioactive compounds previously detected in both lavender and thyme were identified in their extracts using a triple quadrupole/linear ion trap mass spectrometer. Assessment of in vitro phytoprotective action of L. dentata extract in solid and liquid growth media demonstrated inhibitory effects against F. oxysporum f.sp. radicis-lycopersici at concentrations above 1% v/v, with inhibitory effects of L. dentata extract being observed at concentrations equal to or above 2% v/v. T. vulgaris extract inhibited V. dahliae growth on solid media at concentrations at 1% v/v or above, while inhibitory effects were observed in broth media containing 2% v/v thyme extract. Seed germination tests of both L. dentata and T. vulgaris revealed a concentration-dependent reduction in their germination index (GI) at concentrations equal or above 2% v/v, apart from the effect of lavender extract on cress, where inhibition occurred at dose application above 5% v/v. In planta experiments demonstrated the complete phytoprotective action of lavender extract against F. oxysporum f.sp. radicis-lycopersici, while a marginal improvement in plant survival was observed during application of T. vulgaris extract. Full article

To enhance the utilization of industrial coal gangue, response surface methodology was used to optimize the concrete mix proportions based on three key factors: the mass ratio of fly ash (FA) to metakaolin (MK) (A), the combined dosage of FA and MK (B), and the water-to-binder ratio (C). A quadratic regression model was established, and the optimal mixture was characterized using FT-IR, XRD, and SEM. The model exhibited high statistical significance (p < 0.001) and an excellent fit (R² > 0.95), confirming its predictive reliability. Single-factor analysis revealed that the order of influence on 28 d compressive strength was C > A > B, indicating that the water-to-binder ratio had the most significant effect on later-age strength. The optimal mix proportions were determined as follows: fly ash-to-MK ratio of 0.65, admixture dosage of 20% by mass of total binder, and C of 0.475. Under these conditions, the measured 28 d compressive strength reached 35.9 MPa, which was within 5% of the model-predicted value, thereby validating the model’s accuracy. Microstructural analysis demonstrated that the appropriate incorporation of FA and MK promoted the formation of C-S-H gel, refined the pore structure, and improved the quality of the interfacial transition zone, which collectively enhanced the mechanical performance. A systematic understanding of the strength and microstructural mechanisms of concrete incorporating coal gangue, fly ash, and metakaolin is currently lacking, which hinders the design of more robust and durable structures. This study addresses this gap by systematically clarifying the individual and combined effects of the key variables on the strength of coal gangue concrete. The findings reveal the underlying mechanisms, providing a scientific basis for the sustainable, large-scale application of coal gangue concrete in construction. Full article

Background/Objectives: Malnutrition in cancer adversely affects treatment outcomes and survival. Early intervention through oral nutritional supplements (ONSs) and dietary counseling can improve outcomes. This study evaluated the evolution of nutritional and morphofunctional parameters over three months in malnourished patients with cancer undergoing a comprehensive nutritional support program comprising dietary counseling, physical activity, and a novel concentrated high-protein, high-calorie ONS (cHPHC-ONS) with a high intrinsic leucine content. Methods: A prospective, observational, multicenter cohort study was conducted across 18 public hospitals in Spain. Two hundred thirty malnourished patients with cancer were enrolled: 147 naïve (no ONS treatment in the last three months) and 83 non-naïve (who transitioned to cHPHC-ONS after inadequate response to initial ONSs). Nutritional status was assessed using Global Leadership Initiative on Malnutrition (GLIM) criteria and morphofunctional parameters via bioelectrical impedance analysis, nutritional ultrasound, handgrip strength, the Timed Up and Go (TUG) test, and analysis of biochemical parameters. Results: After three months, 23.8% achieved normal GLIM nutritional status (p < 0.0001), with a greater improvement seen in non-naïve patients (28.4%, p < 0.0001). Weight loss ceased in 42.6% (p < 0.0001). and inflammation resolved for 10.3% (p = 0.0015). Non-naïve patients experienced a significant increase in fat-free mass index (p = 0.0159), appendicular skeletal muscle index (p = 0.0248), and rectus femoris cross-sectional area (p = 0.0016). Muscle strength increased significantly by +1.7 kg (p = 0.0025), and TUG test time decreased by 1.13 s (p = 0.0003) overall. Conclusions: The comprehensive nutritional support program—including a novel cHPHC-ONS, along with dietary and physical activity guidance—significantly improved the nutritional and morphofunctional status of malnourished patients with cancer, with benefits particularly evident in non-naïve individuals. Limitations: Observational design, no control group, short follow-up, and unadjusted non-multivariable comparisons, limiting causal inference. Full article

An investigation was conducted to explore the freeze–thaw resistance of 60–90 MPa high-strength concrete blended with multiple industrial byproducts (limestone powder, fly ash, etc.) and mixed sand (machine-made/tailings sand), aiming to clarify freeze–thaw degradation mechanisms and build reliable damage prediction models. Three water-binder (w/b) ratios (0.30, 0.25, 0.20) and 15 mix proportions were designed, with 30–45% cement replaced by mineral admixtures and 90–100% natural sand by mixed sand. Results show lower w/b ratios improve resistance: the 0.20 ratio yields merely 0.06% mass loss and 96% relative dynamic elastic modulus retention after 400 cycles. Optimized silica fume and limestone powder refine pore structures; fly ash-slag synergy boosts durability via secondary hydration under specific dosage ratios. A 7:3 machine-made/tailings sand mix shows better frost resistance due to improved particle packing and interfacial transition zones. Three damage models were established, with Model III demonstrating high accuracy. This work’s novelty lies in multi-byproduct synergy and multi-factor models, supporting green concrete use in cold regions. Full article

Antioxidant biopolymeric films (ABFs) have emerged as promising bio-based and biodegradable polymer materials for sustainable food packaging, combining environmental sustainability with functional performance. This study identifies convergent design principles governing ABFs through a systematic mapping of research published between 2015 and 2025, organized into thematic discussions covering global trends, material strategies, processing technologies, and structure–property relationships. The analysis reveals a clear transition from biodegradable substitution materials toward performance-driven polymer systems engineered to modulate mass transport phenomena. Polysaccharide- and protein-based matrices dominate current developments due to their chemical functionality and compatibility with natural bioactive compounds; however, their inherent hydrophilicity introduces trade-offs between barrier resistance and controlled release. Recent advances increasingly employ blends, composites, and multilayer architectures to decouple mechanical stability from antioxidant migration. Processing technologies, including casting, extrusion, and multilayer assembly, are shown to play a decisive role in defining diffusion pathways and release kinetics. The findings demonstrate that the effectiveness of ABFs depends primarily on polymer–bioactive interactions and structure–property relationships rather than additive concentration alone. Future progress toward industrial implementation requires scalable fabrication strategies and predictive processing–structure–performance frameworks aligned with circular economy principles. This perspective positions ABFs as functional bio-based polymer systems capable of synchronizing antioxidant release with food oxidation kinetics, contributing to sustainable food packaging solutions. Full article

During deepwater oil and gas production and shut-in operations, the high-pressure and low-temperature environment readily induces hydrate formation of CO₂-rich associated gas in oil–water systems, thereby posing serious flow assurance risks. This study systematically investigated the nucleation, growth, and morphological evolution of hydrates in oil–water systems under different gas-phase states using fully visualized high-pressure apparatus, along with the effects of temperature, pressure, CO₂ concentration, and inhibitors on hydrate formation behavior. The results showed that gas phase transition significantly altered the hydrate induction time, gas consumption, and growth time. However, once the gas was liquefied, mass transfer became hindered, and the growth process exhibited pronounced dynamic fluctuations. Phase transitions caused by variations in CO₂ concentration also exerted a significant influence on hydrate growth, among which the terminal subcooling had the most pronounced effect on the integrated growth index. Compared with monoethylene glycol (MEG), methanol lowered the peak value during the rapid hydrate formation stage, markedly reduced the hydrate growth rate, and led to a prolonged period during which the pressure remained above its initial value. These findings revealed the hydrate formation characteristics in oil–water systems and mechanism of thermodynamic inhibitors, providing a theoretical basis for ensuring flow safety in CO₂-rich oil and gas wellbores and pipelines. Full article

The Research and Observation in Medium Earth Orbit (ROMEO) mission, developed at the University of Stuttgart‘s Institute of Space Systems, seeks to demonstrate a cost-effective exploitation of the medium Earth orbit (MEO) for sustainable access to space. It uses a green propulsion system with water as propellant to reach up to 2500 km altitude starting from a 450 km sun-synchronous orbit (SSO). This paper presents the design and intended use of the ROMEO satellite as well as its two in-house developed camera systems, the public relations (PR) and the near-infrared (NIR) camera system. The PR camera system features two silicon sensors with a Bayer color pattern in a compact, lightweight package and in a cold redundant setup to reduce the impact of radiation-related degradation. Their wide field of view (128 × 96°) allows imaging of the complete visible Earth in the mission‘s final orbit and supports calibration of the Earthshine telescope, which is the primary payload. The NIR camera system uses a commercial InGaAs sensor with a high quantum efficiency up to 1700 nm, coupled to a 100 mm focal length optics assembly that yields a ground sampling distance of 45 m in the initial orbit. Its scientific objectives include monitoring gas flares and wildfires, which are relevant to climate change research, and demonstrating an exoplanet transit detection—an unprecedented capability for a small satellite using a commercial off-the-shelf InGaAs sensor in the NIR spectrum. This paper demonstrates that ROMEO’s compact, low-mass camera systems meet mission constraints while enabling a broad spectrum of scientific and outreach activities. Full article

This study presents a computational investigation of an ingenious Twain co-flow jet (CFJ) airfoil system featuring independently controlled micro-compressors for active flow control. Unlike conventional single-point or synchronously controlled CFJ configurations, the proposed system enables independent tuning of jet momentum coefficients at multiple locations along the airfoil surface. Reynolds-averaged Navier–Stokes (RANS) simulations are employed to analyze the impact of this independent control strategy on boundary layer behavior, lift enhancement, stall delay, and aerodynamic efficiency. The objective of this work is to establish a quantitative relationship between jet momentum distribution and aerodynamic performance, while also evaluating the associated energy consumption characteristics of the system. This technology works incredibly well at low speeds, significantly increasing stall angles and lift coefficients; at higher speeds, it uses less energy and improves the lift-to-drag ratio. Twain configuration offers more accurate control over pressure gradients, enabling adaptive performance during all flight phases. In this work, a Twain-compressor-integrated CFJ system is presented, in which jet momentum coefficients (Cμ = 0.05 and 0.1) are dynamically controlled by two independently controlled micro-compressors across various flight conditions (11.34 m/s, 138 m/s, 208 m/s). By optimizing injection at the leading edge and mid-chord—paired with synchronized suction at strategic withdrawal points—the system achieves precise boundary layer control with near-zero net mass flux. Modulating Cμ improves aerodynamic efficiency while limiting the total propulsion energy expenditure, allowing a smooth transition from high-lift takeoff to low-drag cruise, according to computational fluid dynamics (CFD) analysis. Due to these developments, Twain-compressor CFJ systems are now a scalable option for aircraft that need to be extremely aerodynamically versatile without sacrificing efficiency. Full article

Here, we report a highly efficient and stable catalytic system based on monometallic oxides supported on HY zeolites for the catalytic oxidation of chlorobenzene (CB). Among the transition and rare-earth metal oxides screened, the 30Cu/HY catalyst demonstrates exceptional performance, achieving near 100% CB conversion at 300 °C (500 ppm CB, 10,000 h⁻¹) alongside outstanding 24 h continuous stability without deactivation. Quantitative Py-IR analysis reveals that this superior activity is fundamentally driven by extensive solid-state ion exchange, forming robust Lewis acid centers (Cu-Y structures) that synergize with zeolitic Brønsted acid sites to efficiently polarize and cleave C-Cl bonds. Through an integrated approach combining in situ DRIFTS, real-time mass spectrometry, TGA, and NLDFT pore size analysis, we elucidate that the exceptional deep-oxidation capability of Cu/HY continuously mineralizes carbonaceous intermediates. This property minimizes coke deposition (2.91 wt%) and preserves the hierarchical pore architecture, preventing the coverage of active sites and severe pore blockage by partially oxidized intermediates (such as phenolic, aldehydic, and quinonic species) and stable carbonate species responsible for the deactivation of other metal oxides. These insights provide a mechanistic framework for the rational design of robust, chlorine-resistant catalysts for the sustainable abatement of persistent organic pollutants. Full article

Background: Albania has undergone a rapid demographic transition characterized by pronounced population aging. Comprehensive geriatric assessment—functional performance, validated nutritional screening tools, and systematic evaluation of morbidities—is essential for accurately characterizing frailty and identifying the risk of malnutrition in its early stages. The objective of the present study was to improve the assessment of the health status of Albanian older adults, both community-dwelling and residing in long-term care facilities, by addressing both functional and nutritional components. Methods: This observational study included Albanian older adults aged ≥ 65 years, both institutionalized and community-dwelling. Frailty and nutritional status were assessed using validated questionnaires (Grauer Geriatric Functional Evaluation and Mini Nutritional Assessment—MNA), alongside body composition analysis performed by bioelectrical impedance analysis (BIA). Results: Data for 123 older adults were analyzed (56.9% female; mean age 71.3 ± 7.4 years; 54.5% institutionalized vs. 45.5% community-dwelling). A high prevalence of frailty and multimorbidity was observed, particularly among institutionalized older adults. With regard to nutritional status, marked age-related differences were identified among females, with a pronounced deterioration in those aged over 75 years. Body-composition-derived parameters identified a substantially higher proportion of individuals at risk of malnutrition compared with other conventional anthropometric measures. Low body cell mass index (BCMI) and institutionalization were the factors with the strongest independent associations with frailty (AOR 5.02, 95% CI 1.69–14.87, p = 0.004, and AOR 5.71, 95% CI 1.76–18.54, p = 0.004, respectively), while low BCMI was the only variable associated with an increased risk of malnutrition (AOR 4.88, 95% CI 1.78–13.40, p = 0.002). Conclusions: These exploratory findings suggest that incorporating body composition parameters into geriatric assessment may provide complementary information alongside traditional screening tools to support the development of targeted preventive and therapeutic strategies. Full article