Uniform Stress Research Articles

3D bioprinted thick hepatic constructs with vascular network as a physiologically relevant in vitro organ model.

3D bioprinted thick hepatic constructs with vascular network as a physiologically relevant in vitro organ model.

Numerical Study on Impact Damage and Damage Evolution of Cemented Backfill

To quantitatively describe the damage degree and failure process of the cemented backfill (CB) under dynamic loading, this paper performed numerical split Hopkinson pressure bar (SHPB) impact experiments on CB samples using the ANSYS/LS-DYNA. The damage pattern and failure process of CB samples with four mix ratios (cement-to-sand (c/s) ratios of 1:4, 1:6, 1:8, and 1:10) at different impact velocities (v) (1.5, 1.7, 1.8, and 2.0 m/s) were numerically investigated using the micro-crack density method to define the damage variable (d). The results revealed that the use of a waveform shaper in the numerical simulation yielded a more ideal rectangular wave to ensue uniform stress distribution across the sample’s plane without stress concentration. Numerical simulations effectively depicted the dynamic failure process of the CB, with the overall failure trend exhibiting edge spalling followed by the propagation and interconnection of internal cracks. When the v increased from 1.7 m/s to 1.8 m/s, the d increased by more than 10%. As the v increased from 1.5 m/s to 2.0 m/s, the d for c/s ratios of 1:4, 1:6, 1:8, and 1:10 ranged from 0.238 to 0.336, 0.274 to 0.413, 0.391 to 0.547, and 0.473 to 0.617, respectively. A significant “leap” phenomenon in damage was observed when the c/s ratio changed from 1:6 to 1:8.

Research on the optimization and application of coal pillar width in gob-side entry driving under hard roof condition

The width of the coal pillar is a key factor in the success of the gob-side entry driving (GED) technique. This paper, based on the 4,317 working face at Chengzhuang Coal Mine, reveals the stability mechanism of roadway surrounding rock during GED with coal pillars of different widths. Firstly, a main roof failure mechanical model was established using the “internal and external stress field” theory, and the range of the internal stress field was calculated to be 13.6–15.2 m, with the optimal coal pillar width being 10 m. Then, a FLAC3D numerical model was developed and calibrated. Through simulation, the stress and plastic zone evolution characteristics of coal pillars with widths of 5 m, 10 m, 15 m, and 20 m were compared. The results show that a 5 m coal pillar has weak bearing capacity, is prone to plastic failure, and the surrounding rock stability is poor. A 10 m coal pillar exhibits a more uniform stress distribution, smaller plastic zone, and maintains a certain elastic region, with good bearing capacity and no significant stress concentration. It is the optimal design width, offering strong economic and safety advantages. In contrast, 15 m and 20 m coal pillars show significant stress concentration, threatening coal pillar stability and causing resource waste. Finally, a combined control technique of “hydraulic fracturing roof cutting + roof anchor cable + rib anchor cable” with specific parameters was proposed and successfully applied in the 4,317 tailgate. Field monitoring results showed that the surrounding rock deformation stabilized after 55 days, with a maximum deformation of 151 mm, indicating good control effectiveness.

Acorus calamus L. Essential Oil Induces Oxidative Stress and DNA Replication Disruptions in Root Meristem Cells of Two Fabaceae and Two Brassicaceae Species.

Environmental concerns regarding synthetic herbicides have sparked interest in plant-derived bioactive compounds as eco-friendly alternatives. This study investigated the cellular targets of sweet flag essential oil (Acorus calamus L., SEO at IC50 concentration) in root meristem cells of Fabaceae (Vicia faba, Lupinus luteus) and Brassicaceae (Brassica napus, Arabidopsis thaliana), focusing on reactive oxygen species (ROS) accumulation (DAB, NBT staining), DNA replication dynamics (EdU labeling), and genome integrity (γ-H2AX immunocytochemistry, TUNEL assay, and DNA electrophoresis). SEO induced oxidative stress (200-250% of control depending on the species) and replication stress, causing DNA double-strand breaks in 50% of proliferating cells, confirmed by γ-H2AX/TUNEL. Consequently, cells were prolonged in the G1 phase, replication activity dropped to 70% of control in Fabaceae and 80% in Brassicaceae, and EdU incorporation intensity decreased to 80% and 70% of control, respectively. An increased proportion of cells replicating heterochromatin indicated slowed S-phase progression. Despite genotoxic effects, SEO did not trigger endoreplication, apoptotic DNA fragmentation, or extensive cell death. All species exhibited a uniform stress response, although sensitivity varied, which previously enabled the establishment of selective SEO doses between Fabaceae and Brassicaceae. These findings suggest that SEO exerts phytotoxicity by disrupting S-phase progression, supporting its potential as a selective bioherbicide.

Biomechanical evaluation of oblique lateral interbody fusion with various fixation methods for degenerative lumbar scoliosis: a finite element analysis considering different bone densities

BackgroundFew studies have been conducted on the biomechanical stability of oblique lumbar interbody fusion (OLIF) in conjunction with different fixation methods in patients with degenerative lumbar scoliosis (DLS) at varying bone densities. This study uses finite element analysis to assess the biomechanical stability of OLIF with various fixation techniques for treating DLS under differing bone densities.MethodsA three-dimensional finite element model of the lumbar spine (L1-S1) was created using CT scans from a Lenke-Silva IV DLS patient. The control group consisted of a posterior lumbar interbody fusion (PLIF) model. The experimental groups included OLIF Stand Alone (OLIF-SA), OLIF combined with unilateral pedicle screw fixation (UPSF), and OLIF combined with bilateral pedicle screw fixation (BPSF) models. Three bone density conditions—normal bone mass (NBM), osteopenia, and osteoporosis—were used to evaluate these models. The range of motion (ROM) of the surgical segment, the stress distribution of the Cage, endplate, and internal fixation, as well as the peak Von Mises stress, were evaluated by applying a vertical downward load of 400N and a torque of 7.5N·m in different directions.ResultsUnder different bone densities, compared to the PLIF model, the ROM of the surgical segment in the OLIF-SA model was significantly increased, whereas the ROM in the OLIF-UPSF and OLIF-BPSF models was similar to or lower than that of the PLIF. Under NBM and osteopenia, both OLIF-UPSF and OLIF-BPSF effectively reduced the peak Von Mises stress on the endplate and maintained surgical segment stability. However, under osteoporosis, the peak Von Mises stress on the endplate in the OLIF-UPSF model approached or exceeded the maximum yield stress of the endplate (60 MPa) in certain motion states, while OLIF-BPSF demonstrated superior biomechanical stability. Additionally, variations in bone density significantly affected the stress distribution of internal fixation devices, with more uniform stress observed in the OLIF-BPSF model under osteoporosis conditions.ConclusionOLIF-BPSF may provide the best biomechanical stability for patients with DLS, especially osteoporosis patients. However, in patients with NBM and osteopenia, OLIF-UPSF remains an effective treatment option, which can ensure good biomechanical stability while obtaining significant minimally invasive advantages.

Preliminary exploration of finite element biomechanical preoperative planning for complex tibial plateau fractures

The aim of this study was to compare the clinical outcomes, biomechanical performance, and cost-effectiveness of finite element planning (FEP) with those of traditional (Trad) methods in the treatment of complex tibial plateau fractures in middle-aged and elderly patients to ultimately optimize treatment protocols, improve surgical efficiency, and reduce the economic burden on patients. Sixteen patients with complex tibial plateau fractures were randomly divided into FEP and Trad groups, with eight patients in each group. The FEP group underwent preoperative finite element analysis for personalized surgical planning and dual-plate fixation; the Trad group participated in traditional preoperative discussions and underwent a multi-plate fixation. Perioperative and postoperative indicators were collected from both groups, and the stress distribution and displacement under different internal fixation modes were evaluated using finite element analysis. Additionally, a cost-effectiveness analysis was conducted to compare the total costs of internal fixation and hospitalization. The surgical times were significantly shorter in the FEP group than in the Trad group (170.00 ± 59.52 vs. 240.00 ± 59.04 min, p = 0.033), and patients in the Trad group had shorter times to ambulation (12.88 ± 0.99 vs. 14.25 ± 1.49 days, p = 0.047). There were no significant differences between the groups in terms of postoperative orthopaedic scores, mobility indices, fracture healing times, or radiological indicators. Biomechanical analysis revealed that the multiplate fixation mode provided a more uniform stress distribution, but this difference was not statistically significant. In the FEP group, the total costs of internal fixation (4772.25 ± 217.31 vs. 8991.88 ± 2811.25 yuan, p = 0.004) and hospitalization (34796.75 ± 9749.19 vs. 65405.14 ± 28684.80 yuan, p = 0.013) were significantly lower. While ensuring clinical effectiveness, FEP demonstrated greater cost-effectiveness by shortening the surgery time and reducing internal fixation costs. Although the multiplate fixation mode was biomechanically superior to the dual-plate mode, it did not result in significant clinical advantages and was more costly. FEP improves the economic efficiency of treatment for complex tibial plateau fractures in middle-aged and elderly patients and is recommended. This study has certain limitations, such as a small sample size and a short follow-up period. Thus, larger-scale studies with longer-term follow-up data are needed to further validate these findings and explore whether all patient populations can benefit from these practices or if the benefits are limited to specific groups, such as elderly patients or those with certain types of fractures.

Research on Impact Resistance of Double-Decker Ball Bearing Based on Bionic Loofah Structure

Compared to single-decker ball bearings, double-decker ball bearings offer advantages such as higher speed limits, greater load capacity, and better impact performance. However, the inclusion of an additional bearing and adapter ring structure increases its overall mass, limiting its applications. This study addresses the challenges of achieving lightweight design and impact resistance in double-decker ball bearings. Using bionic principles, this study analyzes the internal spatial structure and fiber distribution of loofah to guide the bionic design of the adapter ring in the double-decker ball bearing. A new bearing structure inspired by loofah characteristics is proposed, and a finite element model for its mechanical analysis is developed. The structural response of both the new and traditional double-decker ball bearings is analyzed under varying speeds and impact excitation conditions. The results indicate that the mass of the new adapter ring is reduced by 25.26%, with smaller stress variation and more uniform stress distribution in the bionic design. The overall performance of the new double-decker ball bearing outperforms the traditional design in terms of deformation, equivalent stress, equivalent strain, and contact stress. The proposed bionic loofah-inspired double-decker ball bearing meets both lightweight and impact resistance requirements. The findings provide a theoretical foundation for applying double-decker ball bearings in high-impact and lightweight applications.

Research on the Self-Drilling Anchor Pull-Out Test Model and the Stability of an Anchored Slope

We systematically investigated the anchorage performance of self-drilling anchor bolts in strongly weathered dolomite through integrated field pull-out tests and FLAC3D numerical modeling. The study incorporates symmetry principles in both experimental design and numerical simulations to ensure balanced force distribution and model simplification. Experimental data collected from a slope reinforcement project demonstrated that grouting parameters of 0.8 MPa pressure and 0.8 water–cement ratio achieved an interfacial bond strength of 0.147 MPa, surpassing the recommended value by 22.5%. A modified FLAC3D pile element, calibrated against RS6-01 anchor bolt test data, exhibited improved alignment with load–displacement curves, converging to 272 kN ultimate capacity at 26.1 mm displacement. Symmetrical anchor configurations in the numerical model reduced computational complexity while maintaining accuracy in stress distribution analysis. Through orthogonal experimental design, symmetry-driven parameter optimization identified a 7 m bolt length, 30° installation angle, and 2 m spacing as the most effective configuration. This solution increased the slope safety factor by 19.98% while reducing displacements by 46–62%. The symmetry in anchor spacing and angular alignment contributed to uniform stress redistribution, enhancing slope stability. The findings highlight the synergy between symmetry principles and geotechnical reinforcement strategies.

Enhancing Structural Integrity With Stress‐Resilient Carbon for Stable Potassium‐Ion Storage

AbstractWhile graphite anodes hold promise for potassium‐ion batteries (PIBs), their practical implementation faces critical challenges stemming from mechanical degradation and interfacial compatibility in carbonate ester electrolytes. Herein, a hierarchical porous carbon architecture derived from renewable biomass precursors with stress‐resilient characteristics are developed to enhance structural integrity and cyclability in PIBs. The synergistic combination of homogeneous shell and structural frameworks enables the anode to form an integrated solid electrolyte interphase with uniform stress distribution in carbonate ester‐based electrolyte. The optimized anode delivers a high reversible capacity of 170.3 mAh g−1 at 200 mA g−1, with a capacity retention of 84.0% after 600 cycles. Remarkably, full cells integrating Mn‐based layered oxides and Prussian blue analogue cathodes demonstrate 70.1% and 70.8% capacity retention after 200 cycles. This work establishes a biomass‐to‐device engineering paradigm for sustainable energy storage systems, offering fundamental insights into interface‐structure‐property relationships for alkali‐metal ion batteries.

Investigation of the mechanical anisotropy of the hot isostatic pressing Mar-M247 produced via laser powder bed fusion (LPBF): a perspective on grain characteristics

Abstract The anisotropy in mechanical properties of additively manufactured (AM) superalloys, closely related to grain morphology, grain boundaries, and precipitated phases, impedes their aerospace applications. In this study, the influence of grain characteristics on the mechanical anisotropy of HIP (hot isostatic pressing)/HT(heat treatment) LPBF (laser powder bed fusion) Mar-M247 superalloy was investigated via experimental and finite element (FE) simulation methods. The results indicate that the mechanical properties along the build direction (XZ plane) are superior to those perpendicular to it (XY plane) at multiple temperatures. Particularly, the elongation along the build direction is nearly twice that perpendicular to it. HIP treatment effectively eliminates cracks in the alloy. Grain characteristics reveal columnar grains along the build direction and equiaxed grains perpendicular to it. The Representative Volume Element (RVE) results and the fracture analysis results show that columnar grains exhibit uniform stress distribution, resulting in higher elongation and crack initiation within grains, whereas equiaxed grains show stress concentration at triple junction boundaries, leading to crack initiation and alloy fracture.

Assessing the possibilities of CNT and EFB fiber reinforcement in rammed earth nanocomposites for structural stability enhancement

The object of the study is the rammed earth nanocomposites. Rammed earth nanocomposites reinforced with carbon nanotubes (CNT) and oil palm empty bunch (EFB) fibers provide nanoscale cohesion, and EFB fibers offer macroscale crack bridging, this research aims to significantly improve the material’s mechanical performance. This study pioneers a nanocomposite approach by integrating 1-2 % CNT and EFB fibers into rammed earth, achieving a 539 % increase in compressive strength (from 1.43 MPa to 9.13 MPa) and 34.671 kN buckling resistance to improve structural performance especially for the stability for sustainable construction applications. Standard rammed earth had a compressive strength of 1.43 MPa and buckling resistance, limiting its use; however, when 1 % CNT was added, increased compressive strength to 6.43 MPa (cube) and 6.58 MPa (cylinder), while 2 % CNT further enhanced it to 8.56 MPa and 9.13 MPa, respectively. Flexural strength also improved from 0.98 MPa to 3.60 MPa (beam). Cylindrical specimens showed optimal performance due to uniform stress distribution (34.671 kN buckling resistance). Microstructural analysis reveals CNT enhance nano-scale cohesion while EFB fibers provide macro-scale crack bridging. Compared to conventional concrete, the composite reduces embodied carbon by 62 % (per ISO 14040 LCA standards) and material density by 26 % (1.48 vs 2.0 g/cm3). These findings establish a new paradigm for sustainable seismic-resistant construction in developing tropical regions where both laterite soil and palm oil waste are abundant. The synergy of CNT (nanoscale cohesion) and EFB (load distribution) addresses key limitations. This material is suitable for eco-friendly construction, seismic-resistant structures, and lightweight partitions, offering a sustainable alternative to concrete/steel. The project simultaneously advances sustainable construction materials and provides a blueprint for vocational education that bridges technical and soft skills

Meniscus‐Inspired Segmented Network Intercalation Strategy: Stiffened yet Toughened Toward Healable Antifouling Materials

AbstractHealable antifouling materials contribute a paradigm shift for extending marine infrastructure lifespan by forming continuable biofouling barriers. However, achieving sustainable performance in extreme marine mechanical stresses remains challenging due to the difficulty of integrating stiffness, toughness, and healing performance with antifouling efficacy. Inspired by the meniscus, which facilitates efficient load absorption and distribution ability through the remarkable resilience and accurate intercalation between thigh and calf bones, the structural‐bioinspired segmented network intercalation strategy is proposed. This approach integrates a secondary network with meniscus‐inspired bisphenol segments into the primary, reorganizing rigid phases and optimizing crosslinking in the primary to ensure uniform stress dissipation and augment molecular dynamism. This design yields 212.32% increase in Young’ s modulus (362.42 MPa), 55.62% improvement in toughness (169.52 MJ m−3), and an enhancement in self‐healing efficiency from 72.81% to 98.75%. This strategy establishes a new design principle for durable healable antifouling materials, combining enhanced mechanical properties with resistance against marine biofouling.

Pattern formation in E . coli through negative chemotaxis: Instability, condensation, and merging

Motile bacteria can migrate along chemical gradients in a process known as chemotaxis. When exposed to uniform environmental stress, cells coordinate their chemotactic responses to form millimeter-sized condensates containing hundreds of thousands of motile cells. In this study, we combined experiments with mathematical modeling based on modified Keller-Segel equations to investigate the dynamics of this collective behavior across three distinct timescales: the shortest timescale, where spatial instability emerges; an intermediate timescale, where quasistationary bacterial condensates form; and finally, a longer timescale, during which neighboring bacterial accumulations coalesce. The model closely agrees with experimental results, quantitatively capturing the observed instability, the shape of mature condensates, and their coalescence dynamics. Specifically, we found that the force between neighboring bacterial accumulations decays exponentially with distance due to screening effects. We suggest that the model presented here could describe more broadly the dynamics of stress-induced condensation mediated by bacterial chemotaxis. Published by the American Physical Society 2025

A three-dimensional finite element analysis study on the impact of different prosthetic designs and materials for short-crowned molars with distal subgingival defects.

To evaluate stress distribution in short-crowned molars with distal subgingival defects with various restorations and materials. Residual crowns were restored using a post-and-core crown (model A), a full crown (model B), a fissure-post endocrown (model C), an endocrown (model D), an onlay (model E), and an overlay (model F). The ceramic materials used were IPS e.max (EM), Vita Enamic (VE), and Lava Ultimate (LU). Subsequently, finite element analysis was performed by applying 600 N vertical load (0° to the long axis) and 200 N oblique load (45° to the long axis) to simulate chewing loads. As the elastic modulus of the material increased, the stress on the restorations also increased, particularly under an oblique loading condition. Under vertical and oblique loading conditions, the peak maximum principal stress (MPS) in the dentin was lowest in Group A-EM (17.28 MPa and 5.61 MPa, respectively), following the trend A < B, C < D, F < E. The MPS within the cement was lowest in Group A-EM (2.74 MPa and 2.58 MPa under vertical and oblique loading conditions, respectively). The MPS within the cement in Group H (4.11 MPa) was reduced to approximately one-third of that in Group G (12.35 MPa). EM exhibited a more uniform stress distribution than other materials and is a promising material for short-crowned molars. A fissure-post endocrown design is a potentially favorable restorative option for short-crowned molars. Fiber posts should be used with full crown restorations.

First metacarpal extension-abduction osteotomy effect on joint remodeling and articular cartilage repair in thumb carpometacarpal osteoarthritis

BackgroundThe first metacarpal osteotomy is a joint-preserving surgery for thumb carpometacarpal (CMC) osteoarthritis that improves pain and function. However, its effects on joint remodeling and articular cartilage repair under physiological conditions remain unclear. This study aimed to clarify these aspects using computed tomography (CT)-based subchondral bone density analysis and arthroscopic evaluation.MethodsFifteen hands of 14 patients who underwent a first metacarpal extension-abduction osteotomy for thumb CMC osteoarthritis were included. CT scans were performed preoperatively and one year postoperatively to assess changes in subchondral bone density (measured in Hounsfield units [HU]) across nine regions of the first metacarpal and trapezium articular surfaces. Arthroscopic evaluation of the articular cartilage was performed at the time of osteotomy and at implant removal one year postoperatively using the International Cartilage Repair Society (ICRS) grading scale.ResultsPreoperatively, higher HU values (median [interquartile range]) were observed in the palmar regions of the first metacarpal (758 [643–803] HU) and the central regions of the trapezium (898 [867–960] HU). One year after osteotomy, these values decreased significantly in these initially high-stress regions (first metacarpal palmar regions: 433 [307–475] HU, p <.001; trapezium central regions: 571 [508–649] HU, p <.001; Wilcoxon matched-pairs signed rank test), indicating a more uniform stress distribution. Arthroscopic evaluation revealed improvements in ICRS grade in five out of nine cases on the metacarpal side and four out of nine cases on the trapezium side.ConclusionsThe first metacarpal extension-abduction osteotomy alters the abnormal stress distribution patterns in thumb CMC osteoarthritis, leading to a more uniform stress distribution across the joint. Arthroscopic findings suggest that articular cartilage repair may occur following osteotomy. These results provide new insights into the mechanisms underlying the clinical benefits of this procedure and support its use as a joint-preserving surgery for thumb CMC osteoarthritis.

The Behavior of Reinforced Concrete Slabs Strengthened by Different Patterns and Percentages of Carbon Fiber-Reinforced Polymer (CFRP) Plate

The use of fiber-reinforced polymer (FRP) composites in retrofitting and strengthening reinforced concrete (RC) slabs has gained substantial attention due to their durability, high strength-to-weight ratio, and ease of application. The objective of this study was to theoretically investigate the flexural behavior of RC slabs strengthened with carbon fiber-reinforced polymer (CFRP) plates applied in different percentages and patterns using finite element methods (FEMs) in comparison with the experiment outcomes available in the literature using the ABAQUS software (version 2020). This study focused on understanding the influence of the CFRP configuration on the structural behavior, including the load-carrying capacity, flexural performance, crack patterns, and failure modes, under static loading on seventeen RC slabs of 1800 × 1800 mm and 150 mm thickness. A comprehensive program was adopted, where RC slabs were strengthened using CFRP plates with different coverage percentages (0.044, 0.088, 0.133, 0.178, and 0.223) and arrangements (unidirectional, cross-hatched, and grid patterns) to evaluate the slabs’ performance under realistic service conditions. After comparison, the results validate that the percentage and pattern of CFRP plates influence the performance of RC slabs. Higher CFRP plate percentages yielded greater strength enhancement, while optimized patterns guaranteed a uniform stress distribution and delayed crack initiation. This study hypothesizes that the flexural strength, stiffness, and failure behavior of RC slabs are significantly affected by the percentage and arrangement of CFRP strengthening, with certain configurations providing superior structural performance. The use of CFRP cross-hatched plates improved the load–deflection behavior, increasing the ultimate loads by 35% (452 kN) while reducing ultimate deflection, with the cross-hatched CFRP specimen showing the highest deflection among all the CFRP specimens. This study provides engineers and practitioners with valuable information on choosing appropriate strengthening plans for RC slabs using CFRP plates, leading to more cost-effective and ecologically friendly structural rehabilitation methods.

Influence of Print Speed on the Mechanical Performance of 3D-Printed Bio-Polymer Polylactic Acid.

This study investigates the effect of 3D printing speed on the mechanical strength of parts produced with high-speed PLA. Samples were tested according to the ISO 527-1 standard, focusing on tensile strength. The results reveal that increasing the print speed from 30 mm/s to 500 mm/s reduces the mechanical strength of the samples, although the difference is minimal and does not affect the surface quality when the material is appropriately selected. Additionally, the orientation of the samples on the build plate had a significant impact on their strength, with samples printed along the Y-axis exhibiting better tensile performance. Ironing, which smooths the surface at the end of the print, improved the fracture surface consistency and tensile strength, regardless of the print speed. The improvement in tensile strength observed in ironed specimens can be attributed to improved bonding of the layers, reduced porosity, and a reduction in stress concentration points, which ultimately contributed to more uniform stress distribution and less risk of premature failure. Thermal camera images indicated no significant deviations in heat distribution, excluding this factor as a cause for inconsistent fracture points. This study concludes that higher printing speeds offer time and energy savings with minimal impact on mechanical properties, making them suitable for prototyping and decorative elements, although the effects of print speed and orientation should be considered for applications requiring higher strength.

Tooth Movement Patterns Based on Traction Methods for Mandibular Canine Retraction Using Skeletal Anchorage: A Finite Element Analysis

Objective: This study compared the tooth movement patterns of a power arm and a lever jig during mandibular canine retraction into a premolar extraction space using skeletal anchorage. Methods: A finite element model was developed based on anatomical structures. A mini-implant was placed between the mandibular second premolar and first molar, and canine retraction was simulated using a power arm and a lever jig. The lever jig’s vertical arm lengths were 6 mm, 8 mm, and 10 mm, corresponding to force application distances of 4.5 mm, 6.4 mm, and 8.2 mm from the archwire, matching the power arm. Finite element analysis was performed using linear mechanical properties and an explicit method. Results: With the power arm, increasing vertical length led to greater extrusion, while the posterior force remained unchanged. The lever jig also showed increased extrusion with length but to a lesser extent. Posterior force increased proportionally with the lever jig length. Initial displacement analysis showed greater extrusion and distal tipping with the power arm, while the lever jig suppressed extrusion and facilitated controlled tipping. Stress analysis revealed a more uniform periodontal ligament stress distribution with the lever jig. Conclusion: The lever jig minimizes extrusion and enhances force concentration posteriorly, promoting efficient distal movement.

Influence of Obliquely Spiral Jet Impingement on Flow and Heat Transfer Characteristics of Flat Surface

The comprehensive flow and heat transfer behaviors of obliquely spiral jet impingement on the flat surface were numerically explored. This study involved three-dimensional simulations of obliquely spiral impinging jets for the jet-to-target spacing of 2, using the finite-volume solver ANSYS Fluent to explore near-wall fluid dynamics. The simulations varied jet angles from 45° to 90° and Reynolds numbers from 5000 to 30000. The results showed that the spiral pipe consistently demonstrated better flow uniformity, heat transfer, and wall shear stress distribution than the conventional round pipe, particularly at high jet angles. The swirling flow effect in the spiral pipe enhanced the heat transfer rate, especially in the uphill regions, leading to higher Nusselt number values, with up to 43.9% improvement over the conventional round pipe. The overall heat transfer efficiency increased with both jet angle and Reynolds number.

Engineering High‐Rate Anode Materials via Montmorillonite‐Derived Silicon Nanosheets

Abstract2D Silicon (Si) based materials are promising high‐rate anode candidates due to the short Li+ diffusion pathways and uniform stress distribution during lithiation. However, the complex preparation process, high cost, and side reactions triggered by the large specific surface area limit its application. Herein, a one‐step method is developed to synthesize 2D Si nanosheets from the abundant layered silicate mineral montmorillonite (MMT), via a salt‐assisted magnesiothermic reduction. Then, through spray granulation and high‐temperature pyrolysis, a high‐sphericity Si/C composite (C‐SiNS) is finally prepared. The internal structure of C‐SiNS consists of stacked Si nanosheets with a carbon shell formed by PVP on the surface. The customized structure promotes a high Li+ diffusion rate, effectively alleviates volume expansion, and minimizes side reactions. Benefiting from the robust structural design, C‐SiNS demonstrates excellent rate performance (509.78 mAh·g−1 at a rate of 20 A·g−1) and outstanding long‐term cycling stability (606.80 mAh·g−1 after 500 cycles at 2 A·g−1). The feasibility of its practical application is validated through lithium‐ion full batteries assembled with commercial LiFePO4 cathodes (106 mAh·g−1 after 250 cycles at 0.2 C). The work presents an efficient synthesis strategy for high‐rate anode materials and also provides high‐value utilization potential options of MMT.