Search Results (3,121)

Background/Objectives: Adolescent idiopathic scoliosis (AIS) is a three-dimensional deformity of the spine with multifactorial etiology. Its treatment is conservative and/or surgical. The most commonly used conservative method is a full-time brace. However, nighttime braces have recently gained prominence, offering improved tolerance and a positive impact on health-related quality of life. The main objective of this study was to conduct a narrative review of published articles comparing the effectiveness of Providence nighttime versus full-time brace use to determine whether nighttime use is an effective option for improving therapeutic adherence, health-related quality of life, and psychosocial impact. Methods: A scientific literature search was conducted using the Scopus and PubMed databases. We searched for randomized controlled trials (RCTs), meta-analyses, systematic reviews and retrospective comparative studies reported in English from 2019 to 2024. The literature search was conducted from October to April 2024. Different combinations of the terms and MeSH terms “adolescent”, “idiopathic”, “scoliosis”, “Providence”, “full-time” and “brace” connected with various Boolean operators were included. Results: Overall, 70 articles were reviewed from the selected database. After removing duplicated papers and title/abstract screening, 10 studies were included in our review. The results showed that nighttime brace use has similar results in terms of effectiveness to full-time brace use in mild to moderate curves. However, nighttime brace use improves therapeutic adherence, health-related quality of life and psychosocial impact. Nevertheless, the effectiveness of night braces depends on factors such as curve type, magnitude, and bone maturity. So, in patients with moderate-severe curves and high growth velocity, it is important to reconsider the type of brace, as in these cases night braces alone may be ineffective in slowing the progression of the curve. Conclusions: Providence nighttime brace could be an effective treatment and better tolerated alternative to full-time brace in specific cases. This approach could improve therapeutic adherence. Nevertheless, more controlled and homogeneous studies are needed to establish definitive recommendations. Full article

The paper deals with the design of forward-inclined blades, where “forward inclination” is intended as the design-dependent amount of forward sweep to be incorporated in non-free-vortex blades to restore quasi-2D flow behaviour within the rotor passages. The aim of the work is to assess the effectiveness of this design modification in a 0.5 hub-to-tip ratio fan with radially stacked blades that induce a roughly constant swirl velocity at the rotor exit. To this end, the original blade has been modified by incorporation of a forward sweep amount that translates into a forward-inclined design, defined in accordance with a method suggested by the authors. Both the original and forward-inclined design were preliminary assessed by CFD and finally verified by experiments. The forward-inclined design demonstrated experimentally to improve the pressure rise and efficiency of the original fan in the whole operation range with ca. 10% gain at design operation. Full article

This study analyzes a hybrid computational framework that combines peridynamics (PD) and the finite element (FE) method to model wave propagation in a one-dimensional bar, focusing on their integration for enhanced accuracy and efficiency. The analysis investigates PD’s ability to capture non-local interactions in regions near loading points, with computationally efficient coarse discretization in other areas through finite element methods. The dynamic response to symmetric and asymmetric axial loading, including loading and unloading phases, is analyzed through time-dependent external forces, solving displacement, velocity, and acceleration fields at each time step. The effects of PD-specific parameters, such as the horizon size, and the FE–PD node spacing size ratios on the performance of the hybrid model in wave propagation are investigated. Additionally, the study examines the von Neumann stability for PD to ensure stability and reliability, offering a robust framework for integrating PD and FE in dynamic analyses. Full article

Extensive research has addressed concrete deterioration and its countermeasures; however, studies on responsive repair methods and materials remain comparatively limited and less systematic. In this study, six mixtures of repair mortars (RMs) were formulated using aluminate-based binders, specifically calcium sulfoaluminate (CSA) and amorphous calcium aluminate (ACA) cements. The experiment evaluated the mechanical properties and freeze–thaw resistance of these mortars. To accelerate hydration, a controlled amount of anhydrite gypsum was incorporated into each mixture. The fluidity and setting time of fresh RMs were measured, whereas the compressive strength, flexural strength, and ultrasonic pulse velocity (UPV) of hardened RMs were evaluated at 1, 7, and 28 days. In addition, freeze–thaw resistance was assessed as per ASTM C666 by determining the relative dynamic modulus of elasticity. Additionally, the hydration products and microstructural characteristics of paste specimens were qualitatively analyzed. The mechanical performance, including strength and UPV, and freeze–thaw resistance of RMs containing ACA were superior to those of RMs containing CSA. In particular, compared to the CSA-containing specimens exposed to freeze–thaw action were significantly deteriorated, the ACA-containing specimens showed excellent resistance with relatively less cracking and spalling. This may imply that ACA is effective as rapid repair materials for concrete structures in cold regions. Microstructural observations revealed variations in hydration products depending on the aluminate binder employed, which significantly influenced the mechanical and durability properties of the RMs. These results may aid the selection of optimal repair materials for deteriorated concrete structures. Full article

Understanding the tribological behavior of additively manufactured polymers is essential for their reliable use in sliding components. Tribological tests were performed on a linear reciprocating tribometer pin-on-plate configuration using a polycarbonate sample (PC–PC). To assess the influence of additive-manufacturing-induced anisotropy, three build orientations (0°, 45°, 90°) were examined. Two normal loads of 39.24 N and 58.86 N, and two sliding velocities of 15 and 20 mm/s were selected to represent typical low-load operating conditions of polymeric components. Tests were conducted in dry contact and with two commercial lubricants exhibiting distinct rheological characteristics. Surface topography was characterized before and after testing to evaluate orientation-dependent roughness evolution, while rheological measurements provided effective viscosities at shear rates corresponding to imposed velocities. Frictional behavior was analyzed through the Stribeck parameter, showing that all configurations operated within boundary or early mixed lubrication regimes. Longitudinal specimen layer orientation (90°) was expected to give the lowest friction. In fact, dominant lowest friction in most of the examination regimes gave the 45° build orientation, whereas the 0° orientation hindered lubricant entrainment and produced the highest boundary interaction. Differences in lubricant viscosity influenced Stribeck positioning and the magnitude of friction reduction, demonstrating strong coupling between layer orientation, roughness evolution, and lubrication performance. Full article

This article represents a numerical approach for estimating the helicopter rotor’s blade longitudinal dynamic characteristics considering several operational parameters. A characterization regarding the blade’s longitudinal, flapping, and vertical responses is derived by solving a system of differential equations that fully describe the rotor’s longitudinal dynamics. Dependencies between the lagging (longitudinal) velocity, the flapping velocity, and the vertical velocity over time are illustrated, taking into consideration the varying flapping frequency in a hovering regime. Additionally, the blade’s longitudinal parameters were evaluated in ground effect conditions when hovering at ${\displaystyle \frac{H}{R}}=1$ and ${\displaystyle \frac{H}{R}}=0.5$. The studied time domain variables represent the rotor’s natural reaction capabilities when a disbalancing condition occurs. Eventually, an increase in the blade’s flapping frequency leads to a rise in the required period for reaching a stable condition with regard to the longitudinal and vertical responses. The ground effect zone reduces the blade’s lagging and flapping reactions as well. Full article

Gypsum has been used as a building material for a long time due to its environmental friendliness, exceptional fire performance, and ease of use. However, it is also known to have poor moisture resistance and lower mechanical performance. Construction and demolition wastes, which can cause many environmental issues if not properly managed, are increasingly recycled as reinforcement materials in gypsum mortar. This study aims to assess the effect of incorporating fine glass waste aggregates into gypsum mortars on their physical, mechanical, and adhesive properties. The effect of replacing sand from 0% to 100% by glass waste in gypsum mortar was investigated using various tests and analyses including scanning electron microscopy (SEM), X-ray diffraction (XRD), thermal analysis (DTA and TGA), setting time, flexural and compressive strengths, adhesive, surface hardness, water absorption, thermal conductivity, and ultrasonic pulse velocity. The results obtained emphasize that glass waste can substitute sand in gypsum mortar, even when used at high replacement levels. Replacing all the sand in mortar with glass waste results in a 11% increase in porosity, a 9% decrease in density, and a 53% decrease in thermal conductivity, while still maintaining acceptable mechanical performances. The adhesive strength shows a great dependence on the nature of the substrate. Full article

With the increasing energy density of lithium-ion batteries, the heat dissipation performance of air-cooled battery energy storage cabinets has become a critical determinant of both system performance and service life. This performance depends strongly on the geometry of the airflow channels and their influence on the internal flow distribution. In this study, the internal flow field of a battery energy storage cabinet was analyzed, and the airflow-channel geometry was optimized using the BOBYQA algorithm. The results indicate that the risk of thermal runaway is largely associated with inadequate airflow design, which leads to localized heat accumulation. Geometric optimization of the airflow channels reduced the maximum hotspot temperature from 72.9 °C to 57.6 °C. The hotspots were concentrated at the tops of the battery modules. Modifications to the channel geometry increased the airflow velocity and improved its directionality in these regions, thereby reducing both the hotspot temperature and the extent of the affected area. Moreover, slightly increasing the inlet pressure while reducing the outlet pressure produced a more uniform temperature distribution across the tops of the battery modules. Full article

This study presents a method for enriching oil-suspended particles within a rectangular microfluidic channel using acoustic standing waves. A modified Helmholtz equation is solved to establish the acoustic field model, and the equilibrium between acoustic radiation forces and viscous drag is described by combining Gor’kov potential theory with the Stokes drag model. Based on this force balance, the particle motion equation is derived, enabling the determination of the critical particle size necessary for efficient enrichment in oil-filled microchannels. A two-dimensional standing-wave microchannel model is subsequently developed, and the influences of acoustic, fluidic, and particle parameters on particle migration and aggregation are systematically investigated through theoretical analysis and numerical simulations. The results indicate that when the channel dimension and acoustic wavelength satisfy the half-wavelength resonance condition, a stable standing-wave field forms, effectively focusing suspended particles at the acoustic pressure nodes. Enrichment efficiency is found to be strongly dependent on inlet flow velocity, particle diameter, acoustic frequency, temperature, and particle density. Lower flow velocities and larger particle sizes result in higher enrichment efficiencies, with the most uniform and stable pressure distribution achieved when the acoustic frequency matches the resonant channel width. Increases in temperature and particle density enhance the acoustic radiation force, thereby accelerating the aggregation of particles. These findings offer theoretical foundations and practical insights for acoustically assisted online monitoring of wear particles in lubricating oils, contributing to advanced condition assessment and fault diagnosis in mechanical systems. Full article

Ecological flow management is important for maintaining ecosystem stability and promoting sustainable development. Dynamic ecological flow regulation depends on precise real-time monitoring of water levels and flow velocities. To address challenges in ecological flow monitoring, including maintenance difficulties and insufficient accuracy, an improved DSC-YOLOv8n-seg model is proposed for dynamic multi-parameter sensing, achieving more efficient object detection and semantic segmentation. Compared with traditional affine transformation-edge detection, this approach enables joint recognition of water level lines and staff gauge characters, achieving an average recognition error of ±1.2 cm, with a model accuracy of 93.1%, recall rate of 94.5%, and mAP50:95 of 93.9%. A deep learning-based spectral principal direction recognition method was also employed to calculate the surface water flow velocity, which demonstrated stable and efficient performance, achieving a relative error of 0.005 m/s for the surface velocity. Experimental results confirm that it can effectively address issues such as environmental interference, exhibiting enhanced robustness in low-light and nighttime scenarios. The proposed method provides efficient and accurate identification for dynamic water level monitoring and for real-time detection of river surface flow velocities to improve ecological flow management. Full article

With the rapid advancement of integrated thermal management systems (ITMS) for new energy vehicles (NEVs), flow losses and hydrodynamic characteristics within multi-way valves have become critical determinants of system performance. In this study, a three-dimensional computational fluid dynamics model is established for a multi-way valve used in a representative NEV ITMS, where PAG46 coolant is employed as the working fluid. The steady-state pressure-loss characteristics under three typical operating modes—cooling, heating, and waste heat recovery—are investigated, together with the transient hydrodynamic response during mode switching. The steady-state results indicate that pressure losses are primarily concentrated in regions with abrupt changes in flow direction and sudden variations in cross-sectional area, and that the cooling mode generally exhibits the highest overall pressure loss due to the involvement of all flow channels and stronger flow curvature. Furthermore, a parametric analysis of the valve body corner chamfers and valve spool fillets reveals a non-monotonic dependence of pressure drop on chamfer radius, highlighting a trade-off between streamline smoothness and the effective flow cross-sectional area. Transient analysis, exemplified by the transition from heating to waste heat recovery mode, demonstrates that dynamic changes in channel opening induce a significant reconstruction of the internal velocity and pressure fields. Local high-velocity zones, transient pressure peaks, and pronounced fluctuations of hydraulic torque on the valve spool emerge during the switching process, imposing higher requirements on the torque output and motion stability of the actuator mechanism. Consequently, this study provides a theoretical basis and engineering guidance for the structural optimization and actuator matching of multi-way valves in NEV thermal management systems. Full article

Pneumatic separation can exhibit unstable performance when the feed composition fluctuates while operating parameters remain fixed. This work investigates a perception-informed airflow regulation approach, demonstrated on a representative fibrous–granular mixture case study. We propose LGDNet, a lightweight visual ratio estimation network (0.08 M parameters) built with Ghost-based operations and learned grouped channel convolution (LGCC), to estimate mixture composition from dense images. A dedicated 21-class dataset (0–100% in 5% increments) containing approximately 21,000 augmented images was constructed for training and evaluation. LGDNet achieves a Top-1 accuracy of 66.86%, an interval accuracy of 74.10% within a $\pm 5\%$ tolerance, and an MAE of 4.85, with an average inference latency of 28.25 ms per image under the unified benchmark settings. To assess the regulation mechanism, a coupled CFD–DEM simulation model of a zigzag air classifier was built and used to compare a regime-dependent airflow policy with a fixed-velocity baseline under representative prescribed inlet ratios. Under high impurity loading ($r=70\%$), the dynamic policy improves product purity by approximately 1.5 percentage points in simulation. Together, the real-image perception evaluation and the mechanism-level simulation study suggest the feasibility of using visual ratio estimation to inform airflow adjustment; broader generalization and further on-site validation on real equipment will be pursued in future work. Full article

Neuropathic pain (NPP) remains therapeutically challenging, with oxidative/nitrosative stress and neuroinflammation—amplified by nitric oxide (NO)—as key drivers. This study investigated geraniin (GRN), a naturally occurring hydrolyzable ellagitannin widely distributed in various plant species, including Phyllanthus spp. and Nephelium lappaceum (rambutan), in a rat model of sciatic nerve chronic constriction injury (CCI), focusing on NO-pathway involvement. Male Wistar rats (n = 8/group) received intraperitoneal GRN (3, 10, 30, or 100 mg/kg) or vehicle (1% DMSO in saline) daily for 21 days. Behavioral (thermal hyperalgesia, mechanical allodynia, sciatic functional index), electrophysiological (nerve conduction velocity), and biochemical markers—oxidative/nitrosative stress (nitrite, MDA), antioxidant defenses (GSH, SOD, CAT), inflammation (TNF-α, IL-1β, IL-6, MPO), and apoptosis (caspase-3)—were quantified. L-arginine or L-NAME was co-administered to probe NO signaling. GRN at 30 and 100 mg/kg produced significant antinociceptive and neuroprotective effects; 30 mg/kg was selected for detailed analysis. By day 21, GRN improved pain thresholds and nerve conduction, enhanced antioxidant capacity, suppressed inflammatory mediators, and reduced caspase-3 activity. L-arginine reversed, whereas L-NAME potentiated these effects, confirming NO-dependent modulation. Collectively, GRN mitigates CCI-induced NPP via coordinated antioxidant, anti-inflammatory, and anti-apoptotic actions, supporting its potential as a multi-target candidate for pharmacokinetic and translational development. Full article

We investigate momentum transport in ferromagnetic–plasmon heterostructures using Keldysh field theory and energy–momentum tensor formalism. A three-layer model reveals that plasmon frequency shifts generate a non-zero expectation value for the $xz$-component of the energy–momentum tensor $⟨T_{xz}⟩$ through magnon–plasmon coupling. The momentum transport exhibits linear velocity dependence, with temperature behavior transitioning from exponential suppression at low temperatures to linear growth at high temperatures, governed by the magnon energy gap. Spatial oscillations follow $sin(2n\pi z/h)$ patterns within the ferromagnetic layer. This framework provides fundamental insights into quantum momentum transport mechanisms in magnetic systems. Full article

Cardiovascular disease (CVD) remains the leading cause of death worldwide, accounting for nearly one-third of global mortality. Arterial stiffening, particularly in the central elastic arteries, impairs the Windkessel (cushioning and pumping) function and contributes to cardiovascular risk beyond traditional factors. Carotid–femoral pulse wave velocity (cfPWV) is established as the gold standard for assessing aortic stiffness and predicting cardiovascular and all-cause mortality; however, its technical complexity and requirement for trained personnel limit its use in routine clinical and community settings. These challenges have driven the development of simplified techniques for population screening, such as brachial–ankle PWV (baPWV). More recently, single-cuff oscillometric devices have emerged as practical alternatives. These methods are simple enough to be implemented in daily healthcare at home, thereby greatly enhancing accessibility, although their accuracy depends on model assumptions and calibration. In this perspective article, we highlight the pathophysiological significance of preserving the central arterial Windkessel function and emphasize the need for its practical assessment. Recent innovations mark a paradigm shift from complex laboratory-based measurements toward simplified, data-driven, and socially feasible screening tools for the early detection and prevention of CVD. Full article