Search Results (262)

A multibody simulation model for deep-groove ball bearings is presented. The model considers friction in both the raceway and cage contacts, resulting from radial and axial loads. The model is validated against experimental measurements for a 6319 bearing under oil-bath lubrication over a speed range of 500–3000 min⁻¹ and two load ratios ($C/P=10$ and 6.5). Predicted friction torques show good agreement with measurements, with deviations between 5.5% and 22% at moderate speeds. In addition, electrical contact capacitances are calculated for a 6208 bearing and compared with an analytical approach, showing deviations in the range of 10–14%. Beyond friction prediction, the fully dynamic approach enables time-resolved analysis of roller kinematics and the identification of instability limits under axial excitation. The developed tool therefore enables reliable bearing loss prediction, supports efficiency-oriented drivetrain design, and provides a basis for electro-tribological and stability investigations. Full article

Cervical spondylosis is a common cause of spinal cord dysfunction, and anterior cervical discectomy and fusion (ACDF) is widely employed when conservative treatment fails. Conventional implant systems such as the cervical cage with plate (CCP) and zero-profile stand-alone cage (ZPSC) are commonly used to enhance spinal stability and promote fusion, but they are associated with complications including dysphagia and adjacent segment degeneration. To address these limitations, a novel flexible plate cage system (FPCS) has been developed to optimize biomechanical performance while minimizing surgical risk. In this study, a finite element model of the C3–T1 cervical spine was constructed to simulate ACDF at the C5–C6 level using CCP, ZPSC, and FPCS implants. Under standardized loading conditions, von Mises stress was analyzed in the bone, intervertebral disc, endplates, cage, and screws, using the mean of the top 5% stress values to ensure accuracy. All surgical models showed increased stress compared to the intact reference spine. The ZPSC model exhibited the highest stress in the cage and screws, suggesting a more concentrated load path. The CCP model showed a more evenly distributed stress profile, particularly affecting the inferior adjacent segment. The FPCS model demonstrated moderate cage stress, reduced screw stress, and the highest plate stress, indicating a design that effectively redirects mechanical load from the screw-bone interface toward the anterior plate. This may be related to the unique structural configuration of the FPCS, which secures screws horizontally into the anterior vertebral body without penetrating the endplates. These findings suggest that the FPCS may offer a biomechanically favorable alternative to existing ACDF implants. Full article

The drive systems of new energy vehicles, which employ high-speed motors and low-viscosity lubricants, often subject motor bearings to high-temperature and oil-starved conditions. This can lead to the deformation of polymer bearing cages, resulting in abnormal vibration and noise. In this study, polyimide/molybdenum disulfide (PI/MoS₂) composites were prepared, and their thermal stability was characterized using a dynamic mechanical analysis (DMA). High-temperature friction and wear tests against ceramic balls were conducted on a multifunctional tribometer. The wear behavior and surface element distribution were examined by laser confocal microscopy (LCSM), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). Results indicate that the PI-MoS₂ composites effectively mitigate surface contact deformation with rising temperatures, reducing the wear loss by around 30% compared to pure PI. This improvement is attributed to the enhanced heat resistance from MoS₂ and the formation of a lubricating film during friction. The findings provide guidance for selecting and designing composite materials for high-speed bearing cages. Full article

This study investigates the floating wind turbine (FWT)–Net cage integrated platform, where the net cage is rigidly connected to the FWT foundation. The platform is numerically modeled using time-domain simulations in OrcaFlex V11.1, based on representative environmental conditions of the South China Sea. The operational performance of two layouts of the platform is evaluated and compared, considering both power generation efficiency and residual volume ratio as key indicators. The results show that the FWT–Net cage integrated platform exhibits superior hydrodynamic stability, characterized by reduced surge and pitch motions, lower mooring force fluctuations, and a higher residual cage volume. Additionally, the platform achieves better power generation efficiency and a higher residual volume ratio, indicating more effective use of the aquaculture space. Based on these findings, an improved integrated design incorporating additional outer net cages is proposed. This design demonstrates enhanced aquaculture capacity while maintaining power generation. The results provide valuable insights for the design of FWT–Net cage integration, promoting the efficient and sustainable utilization of marine space. Full article

Background: Interbody spinal fusion is a common surgical treatment for degenerative, traumatic, and deformity-related spinal pathologies. Despite advances in cage geometry and fixation strategies that improve alignment and early stability, reliable fusion remains limited by the mechanical and biological constraints of conventional interbody implant materials. Traditional titanium and polymer-based cages often fail to optimally balance load sharing, osteointegration, and biological activity within the mechanically demanding interbody environment. This narrative review examines the development and translational potential of 3D-printed interbody fusion devices, with emphasis on how additive manufacturing enables the integration of mechanical performance with biologically active scaffold design. Methods: A thorough literature review was performed to evaluate the evolution, design principles, material properties, and translational outcomes of three-dimensional (3D)-printed interbody fusion devices. Results: Additive manufacturing enables precise control over implant architecture, allowing for the fabrication of porous, lattice-based cages with tunable stiffness, optimized load sharing, and enhanced bone–implant integration. Preclinical and early clinical studies suggest that 3D-printed porous titanium cages may reduce subsidence, promote osteointegration, and improve fusion-related outcomes compared with conventional designs. Emerging evidence indicates that scaffold porosity, surface microtopography, and bioactive coatings influence macrophage polarization, angiogenesis, and osteogenic signaling. Polymeric and composite constructs, particularly hybrid designs incorporating surface functionalization, represent promising adjuncts, though clinical evidence remains limited. Conclusions: Three-dimensional printing represents a paradigm shift in interbody fusion device design. Continued translational research and longer-term clinical follow-up are required to validate efficacy and guide widespread clinical adoption. Full article

Polyether ether ketone (PEEK) is a high-performance thermoplastic with potential applications in aerospace, automotive, and biomedical components, owing to its exceptional specific strength, thermal stability, and biocompatibility. However, its moderate hardness and limited wear resistance in dry sliding severely constrain its use in highly loaded tribological contacts. In this study, PEEK-based reinforced hybrid composites were produced utilizing a powder metallurgy technique, with reinforcement fractions of 10 wt.% graphite (Gr), boron (B), hydroxyapatite (HAp), and zirconium (Zr). The processing sequence included homogeneous wet-mixing, uniaxial cold compaction at pressures of 10–30 MPa, and sintering at 250–300 °C. The composition and microstructures were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX). Mechanical and tribological performances were assessed by Vickers microhardness, uniaxial compression and dry sliding wear tests. The best-performing Gr-B hybrid composite increased hardness by 240% and compressive strength by 175% compared with unreinforced PEEK. Tribologically, boron-containing PEEK demonstrated up to a 34.7% reduction in the coefficient of friction and approximately a 90% drop in wear-induced mass loss compared with unreinforced PEEK. The resulting Gr-B-reinforced PEEK hybrids are excellent choices for demanding load-bearing and tribological components like aerospace bushings, automotive sliding elements, spinal cages, and orthopedic fixation devices in biomedical applications because of their balanced combination of high hardness, superior wear resistance, and high compressive strength. Full article

Octa(3,3,3-trifluoropropyl) polyhedral oligomeric silsesquioxane (8F-POSS) was synthesized via a vertex-capping method and incorporated into natural rubber (NR) and deproteinized natural rubber (DPNR) to fabricate inorganic–organic vulcanizates. Curing characteristics, crosslink density, and the filler–rubber interaction parameter (α) were evaluated. We found that 8F-POSS retarded vulcanization kinetics but eventually enhanced network integrity. Two-dimensional infrared (2D-IR) spectroscopy indicated a hydrogen-bond shielding effect between siloxane cages and protein hydroxyl groups in NR. This interaction governed morphology development: proteins in NR acted as compatibilizers to improve initial POSS dispersion, though at high loadings they compromised reinforcement efficiency (α fell from 18.12 to 9.04). In contrast, DPNR vulcanizates showed stronger direct filler–rubber interactions, with higher α values (25.66–35.58) and a more constrained physical network. Despite a denser physical network, the 8F-POSS cages increased fractional free volume and promoted interfacial frictional slippage, leading to a synergistic “reinforcement–dissipation” effect. As a consequence, 8F-POSS/DPNR vulcanizates exhibited an enhanced damping performance (e.g., a loss factor of 1.26) alongside a depressed Tg, reduced equilibrium swelling in oil from 324% to 147%, high hydrophobicity (water contact angle above 120°), and distinctive multi-stage thermal stability. These findings demonstrate a strategy to manipulate the protein network in NR using nanoscale hybrid fillers for the design of high-performance vulcanizates. Full article

Allyl isothiocyanate (AITC) is a potent natural antimicrobial agent; however, its practical application is severely hindered by its extreme volatility and pungent, irritating odor. In this study, AITC inclusion complexes (AITC@β-CD) were successfully fabricated via a co-precipitation strategy using β-cyclodextrin (β-CD) as the host matrix. Physicochemical characterizations, including FTIR, SEM, and XRD, confirmed the successful integration of AITC into the β-CD framework, inducing a crystalline phase transition from a cage-type to a channel-type structure. TGA demonstrated a substantial enhancement in thermal stability, with the maximum decomposition temperature shifting to 330 °C. This indicates that the spatial confinement within the channel-type lattice acts as a robust molecular shield that minimizes premature volatilization. Notably, water contact angle measurements revealed that the complexes attained a modulated surface wettability (89.0°), attributed to the structural rearrangement of surface hydroxyl groups. This modification ensures that the material remains compatible with aqueous food matrices while notably masking the unpleasant sensory attributes of pure AITC. Antibacterial assays against the standard indicator strain Escherichia coli (E. coli) confirmed that the encapsulation process preserved the intrinsic bioactivity of the guest, exhibiting comparable inhibitory zones to free AITC. Furthermore, the complexes maintained high inhibitory efficacy against indigenous microbial populations from spoiled fruits. These findings suggest that β-CD encapsulation effectively stabilizes AITC through guest-induced co-crystallization and enhances its consumer acceptability, providing a versatile and efficient strategy for sustainable food preservation. Full article

Lumbar interbody fusion is widely performed for degenerative, deformity-related, and instability-associated spinal conditions. Yet, reported outcomes remain variable across grafting strategies and surgical techniques. While advances in instrumentation and cage design improve immediate construct stability, successful arthrodesis depends on early graft behavior within the interbody environment. This includes positional stability, interface contact, and load transfer prior to mature bone formation. Synthetic bone graft substitutes are commonly used to supplement or replace autograft. However, the clinical literature describing these materials is heterogeneous with respect to composition, structural presentation, surgical context, and outcome reporting. This narrative review synthesizes clinical, translational, and biomechanical studies published between 2019 and 2025 that evaluate synthetic bone graft substitutes used in adult lumbar interbody fusion. Rather than comparing individual products or reported fusion rates, grafts are organized by material class and examined through early mechanical events such as graft migration, loss of graft–endplate contact, and cage subsidence. Across recent studies, variability in fusion definitions, imaging modalities, postoperative timepoints, and documentation of early mechanical events limits direct comparison and quantitative synthesis. These findings highlight the need for improved reporting consistency and greater emphasis on engineering-relevant variables in future investigations. Full article

Accurate body-weight monitoring is essential for assessing welfare in cage-free poultry. However, commercial farms continue to rely on manual weighing because of concerns regarding the accuracy and reliability of automated methods. This study developed and evaluated an Internet of things (IoT)-enabled weighing platform integrating load cells, an microcontroller, a Raspberry Pi 5, and Node-RED for data acquisition, processing, and visualization. The system recorded weight measurements at 1 Hz, detected individual weighing sessions, and applied a rolling-median filter to produce stable weight estimates. Validation was performed against a reference scale during two weighing sessions one week apart using 75 cage-free hens randomly selected from a flock of 750 Hy-Line W80 birds. Bland–Altman analysis and a linear mixed-effects model indicated a small overestimation of approximately 6–9 g, with most measurements falling within the 95% limits of agreement, while overall mean absolute percentage error remained below 3%. Improved accuracy during the second session suggests that platform stability influenced performance. Overall, the system demonstrates strong potential for continuous low-stress weight monitoring in poultry farms. Future improvements should focus on refining calibration methods, enhancing mechanical stability, and integrating bird identification and presence-detection mechanisms to further support flock management and welfare monitoring. Full article

This first part of a two-part review examines how Computed Tomography(CT)-based, additively manufactured (AM) porous implants are used to reconstruct large segmental defects of the femur and tibia. We focus on lightweight patient-specific lattice implants, architected cages, and modular porous constructs that incorporate engineered porosity into the load-bearing structure and are deployed with plate-, nail-, or external-fixator-based stabilization. We show how defects are described and classified by size, morphology, and anatomical subsegment; how these descriptors influence fixation choice and the resulting mechanical environment; and where along the femur and tibia porous implants have been applied in clinical and preclinical settings. Across the literature, outcomes appear to depend most strongly on defect morphology and local biology, while fixation feasibility and construct behavior vary by subregional anatomy. Most reported constructs use Ti6Al4V porous architectures intended to share load with fixation, reduce stress shielding, and provide a regenerative space for graft and tissue ingrowth. Finite element analyses (FEA) and bench-top studies consistently indicate that lattice architecture, relative density (RD), and fixation concept jointly control stiffness, micromotion, and fatigue-sensitive regions, whereas early animal and human reports describe promising incorporation and functional recovery in selected cases. However, defect descriptors, fixation reporting, boundary conditions, and outcome metrics remain diverse, and explicit quantitative validation of simulations against mechanical or in vivo measurements is uncommon. Most published work relies on simulation and bench testing, with limited reporting of biological endpoints, leaving a validation gap that prevents direct translation. We emphasize the need for standardized defect and fixation descriptors, harmonized mechanical and modeling protocols, and defect-centered datasets that integrate anatomy, mechanics, and longitudinal outcomes. Across the 27 included studies (may be counted in more than one group), simulation and mechanical testing are reported in 19/27 (70%) and 15/27 (56%), respectively, while in vivo studies (preclinical or clinical) account for 9/27 (33%), highlighting a validation gap that limits translation. Part 2 (under review); of these two series review paper; Patient-Specific Lattice Implants for Segmental Femoral and Tibial Reconstruction (Part 2): CT-Based Personalization, Design Workflows, and Validation-A Review; extends this work by detailing CT-to-implant workflows, lattice design strategies, and methodological validation. Full article

Evaluation of gas hydrate stability in marine sediments is commonly conducted assuming pure methane systems, although increasing drilling and logging evidence indicates that natural gas hydrates frequently contain minor amounts of heavier hydrocarbons. In the northern South China Sea, the presence of ethane has been widely reported, yet its influence on hydrate phase equilibrium and the distribution of the gas hydrate stability zone (GHSZ) remains insufficiently quantified. The results show that ethane is preferentially incorporated into large cages and promotes structure II hydrate stability, leading to lower dissociation pressures and higher stability temperatures compared with pure methane hydrates. Incorporation of as little as 1 mol% ethane systematically deepens the predicted base of the GHSZ and enlarges the hydrate-free gas coexistence interval beneath the bottom-simulating reflector (BSR). These effects indicate that conventional pure CH₄ models underestimate both the thickness of the hydrate stability zone and the potential extent of hydrate occurrence. At the regional scale, composition-dependent stability provides a coherent explanation for discrepancies between seismic BSR depths and hydrate predictions. This study establishes a composition-sensitive framework for regional GHSZ evaluation, demonstrating that even trace hydrocarbons must be considered to reliably assess hydrate occurrence, resource potential, and associated geohazards in continental margin settings. Full article

Offshore aquaculture requires net cages that remain stable under strong currents and during submersion and emergence operations. In this study, we proposed a submersible net cage structure equipped with vertical buoyancy columns as an alternative to the conventional horizontal floating-frame cage and evaluated its stability using a net geometry and load analysis system (NaLA system). Model-scale cages were tested in a recirculating flume tank at two current velocities, and the three-dimensional cage geometry was reconstructed using the multicamera through direct linear transformation method to validate the simulated cage inclination. The NaLA system accurately reproduced the measured geometry and time-varying inclination. After validation, stability was compared over a range of current velocities by tracking the cage inclination during the emergence phase. When mooring lines were attached to the top of the cage, the conventional floating-frame cage exhibited a smaller inclination than the buoyancy-column cage. However, relocating the mooring attachment point on the columns significantly improved the stability; attaching the moorings near the bottom of the columns generated the smallest final inclination and yielded a higher stability than the conventional cage. The buoyancy columns can outperform those of conventional designs when paired with an appropriate mooring configuration, thus offering a promising structure for applications under harsh offshore conditions. Full article

The aim of this study was to evaluate the effects of graded replacement of soybean meal (SBM) with black soldier fly larvae meal (BSFLM) on growth performance, growth dynamics, carcass characteristics, and economic efficiency in Japanese quails (Coturnix japonica). A total of 300 one-day-old quail chicks were randomly allocated to five dietary treatments in which SBM was replaced with BSFLM at 0, 25, 50, 75, or 100% using isocaloric and isonitrogenous diets. Body weight was recorded weekly, feed intake was measured per cage, and growth dynamics were assessed using the Gompertz growth model. At 42 d of age, 150 quails were slaughtered to determine carcass yield and major carcass components, and economic evaluation was performed using scenario-based analyses to compare feed cost efficiency under contrasting ingredient price conditions. Dietary inclusion of BSFLM had no significant effects on body weight at any measured age, mortality rate, or carcass yield and composition. Feed intake and feed conversion ratio were significantly improved at the 50% BSFLM inclusion level, indicating improved feed efficiency at moderate replacement. Gompertz growth parameters, including mature weight, growth rate, and inflection point traits, were not affected by dietary treatment, confirming that intrinsic growth patterns were maintained. Economic analyses showed that partial replacement of SBM with BSFLM was associated with improved or stabilized feed cost efficiency depending on relative ingredient prices, whereas higher inclusion levels were more sensitive to unfavorable price conditions. In conclusion, BSFLM can be incorporated into Japanese quail diets without detrimental effects on growth performance or carcass traits, with moderate inclusion levels providing the most consistent balance between biological efficiency and economic robustness, thereby supporting risk-aware and sustainable poultry feeding strategies under variable market conditions. Full article

The rapid expansion of aquaculture necessitates the development of advanced technologies to enhance the stability and survivability of deep-sea aquaculture platforms. This study investigates the hydrodynamic performance of a trussed semi-submersible aquaculture cage (TSAC) through comprehensive wave tank experiments. A 1:32 scaled-down prototype was manufactured and used to evaluate key hydrodynamic characteristics, including the natural frequency, radiation damping, horizontal mooring stiffness, Response Amplitude Operator (RAO), and mooring force, under regular wave excitation. Experimental results indicate that the pitch RAO can reach a value of up to $32.8$$7^{°}/\mathrm{m}$ under high-wave conditions, and the windward-side mooring forces exhibit periodic fluctuations while others remain almost stable. The results provide critical data for the development of high-fidelity numerical models and offer practical insights for the optimal design and deployment of large-scale deep-sea aquaculture platforms, contributing to the advancement of sustainable marine aquaculture technologies. Full article