Thermo-Mechanical Stress Prediction in Steel IPE Profiles under Asymmetric Thermal Loading: A Finite Element and XGBoost-Based Approach

This study examines CMOS ring oscillators that are used as converters of capacitive sensor parameters. The issue with most analytical models is their assumption of symmetric stage loading, making them inaccurate for the topology where a sensor connection to a single node introduces asymmetry. The lack of a validated model for 45-nm technology complicates the design of sensitivity and energy efficiency. An analytical model for the capacity to frequency converter that accounts for asymmetric loading has been built and verified. The model is based on the physical principle of summing asymmetric stage delays and a linear approximation of inverter delay versus load capacitance. A parametric analysis was performed in LTspice (sensor capacitance Csensor is from 0 to 2.5 pF) to verify the model. It was determined that the oscillation period has a quasi-linear dependence on capacitance; therefore, the frequency dependence is hyperbolic. The proposed model predicts the frequency with a maximum relative error of no more than 1.55% over the entire simulation range (21.17–29.96 MHz) compared to SPICE data. Key metrics have been analyzed: the average sensitivity is 3.52 MHz/pF, while the instantaneous sensitivity is non-linear, decreasing from 5.57 MHz/pF to 2.15 MHz/pF. Power consumption increases slightly (151.3–155.7 µW), as the capacitance growth is compensated by the frequency drop. Energy per cycle (Ecycle), conversely, increases almost linearly (5.05–7.35 pJ) with a slope of 0.92 pJ/pF. This closely matches the theoretical value of VDD2 = 1.0 pJ/pF, confirming the dominance of dynamic power consumption. The proposed model allows engineers to accurately predict and design the capacity-to-frequency characteristics, sensitivity, as well as power consumption of compact integrated sensor interfaces.

This study examined how hand dominance influences lower-limb biomechanics during single-leg landing in bilateral lay-ups. Because the lay-up is a high-frequency basketball skill that imposes substantial impact loading and requires rapid neuromuscular control, side-dependent landing strategies may contribute to asymmetrical joint loading and elevate injury risk, particularly at the knee and ankle. However, empirical evidence clarifying how hand dominance interacts with lay-up side to shape landing biomechanics remains limited. Thirty male collegiate basketball players (15 left-hand dominant, 15 right-hand dominant) performed standardized right-hand lay-ups with left-leg landing and left-hand lay-ups with right-leg landing on force plates under 3D motion capture. Vertical ground reaction force (VGRF) and sagittal-plane knee and ankle kinematics and kinetics were analyzed using 2 × 2 mixed ANOVA and SnPM1D over the normalized stance phase. Left-hand–dominant players exhibited higher VGRF first peaks (p = 0.001), second peaks (p = 0.012) and total impulse (p < 0.001), with pronounced side-to-side asymmetry, whereas right-hand–dominant players showed more symmetrical loading between lay-up directions. At the joint level, significant Handedness and Side interactions were found for sagittal ROM, peak flexion, joint moments and power. Left-hand–dominant athletes relied on greater knee flexion, higher knee extensor moments and larger ankle and knee power on their preferred support leg. SnPM1D revealed time-dependent differences clustered in early–mid stance (impact attenuation) and late stance (push-off).These findings indicate that hand dominance systematically reorganizes proximal–distal coordination and load distribution during lay-up landings, and that monitoring asymmetry, particularly in left-hand–dominant athletes, may be important for targeted training and injury prevention.

**Background:** Prosthetic gait asymmetry is commonly treated as a functional limitation; however, its long-term orthopedic consequences on the intact limb remain under-recognized. This study investigates how chronic asymmetrical loading patterns influence degenerative risk in unilateral lower-limb amputees. **Methods:** Nineteen individuals with unilateral transtibial amputation (16 male, 3 female; age 49.5 ± 11.3 years) participated in a 12-month longitudinal study. Gait analysis was performed at baseline, 6 months, and 12 months using force plates and 3D motion capture. We analyzed temporal symmetry (stance time ratio), force symmetry (vertical ground reaction force [vGRF] ratio), intact limb joint moments, and clinical outcomes (WOMAC pain scores, radiographic Kellgren-Lawrence [KL] osteoarthritis grade). **Results:** Over 12 months, significant deleterious changes were observed despite some participants improving temporal symmetry. Force symmetry significantly worsened (0.701 to 0.663; p < 0.001), while intact limb knee flexion and adduction moments significantly increased by 6.6% and 7.7%, respectively (p < 0.001). WOMAC pain scores increased by 26.4% (p = 0.0001). Baseline force symmetry was significantly correlated with baseline knee flexion moment (r = 0.479, p = 0.038). Notably, subjects with improved inter-limb temporal symmetry but unresolved force asymmetry continued to demonstrate elevated intact-limb tissue stress. **Conclusion:** These findings emphasize that restoring visual or temporal gait symmetry is insufficient without addressing underlying mechanical load distribution. Compensatory strategies—particularly increased intact-side stance time, vertical loading rate, and frontal-plane knee moments—are more predictive of osteoarthritic progression than prosthetic design alone. The study supports biomechanically informed prosthetic tuning and neuromuscular retraining strategies aimed at protecting the intact limb over the lifespan.

ABSTRACTBackgroundRecent advancements in next‐generation bioreactors have substantially improved the simulation of complex, detrimental spinal mechanics in ex vivo intervertebral disc models. This study investigated intervertebral disc responses to combined flexion, torsion, and static compression. A range of loading frequencies, magnitudes, and patterns was applied to identify conditions that contribute to disc degeneration under complex motion.MethodsTwelve bovine coccygeal intervertebral discs (mean age 9 months) were subjected to three distinct loading regimes, with four samples per condition. Static compression of 0.1 MPa was combined with: (1) symmetrical 3° flexion/extension and 2° torsion, (2) symmetrical 6° flexion/extension and 4° torsion, and (3) asymmetrical 6° flexion and 4° torsion. Loading frequencies and durations ranged from 0.2 Hz for 1 h in symmetrical loading to 1 Hz for 2 h in asymmetrical loading over a 14‐day period. Structural integrity, cell viability, tissue composition, and molecular responses were evaluated using histology, biochemical assays, and gene expression analysis.ResultsLower‐cycle symmetrical flexion/extension and torsion, regardless of magnitude, preserved disc structure and maintained a high cell viability (88% ± 14%) across all disc regions. Higher cycle numbers and asymmetrical loading induced significant fissures in the outer annulus fibrosus (AF) on the tensed side (p < 0.01) and delamination on the compressed side. This structural damage occurred in AF regions with high cell viability (81% ± 17%), whereas significantly reduced cell viability was observed in the inner AF (30% ± 33%) and nucleus pulposus (28% ± 35%).ConclusionsUnder conditions of asymmetrical and more frequent loading, complex motion involving flexion, torsion, and compression led to structural damage in the outer disc regions and promoted cell death in inner regions. These region‐specific responses suggest the independent development of distinct failure mechanisms contributing to disc degeneration. They also underscore the importance of developing targeted strategies that address both structural integrity and cellular resilience in degeneration models and therapeutic interventions.

ABSTRACT Context The highest incidences of musculoskeletal (MSK) injuries within the military occur at anatomical regions most impacted by jumping and landing, including the knee. Military personnel assigned to Special Operations Forces (SOF) are at particularly high risk of MSK injury due to occupational demands. Objective To characterize changes in limb loading symmetry during walking gait from 6 to 12 months after ACLR in patients with extensor mechanism autografts using force-sensing insoles, and to compare the change in limb loading metrics between patients with bone-patellar tendon-bone (BPTB) and quadriceps tendon (QT) autograft. Design Cross-Sectional Study Setting Laboratory Patients or Other Participants Two hundred twenty-four uninjured active-duty male SOF personnel (age = 27.7 ± 5.0 years; mass = 83.1 ± 9.1 kg; height = 176.5 ± 5.7 cm) completed biomechanical analyses of two different drop landing tasks (double leg (DLDL) and single leg (SLDL)) and isokinetic strength testing of the quadriceps and hamstrings. Main Outcome Measure(s) Peak hip, knee, and ankle angles; hip, knee, and ankle angles at initial ground contact (@IC); and peak vertical ground reaction (VGRF) forces were identified during landing tasks. Maximum voluntary isokinetic knee extension strength (KES) and knee flexion strength (KFS) were also assessed. Results Participants demonstrated greater KES with their dominant limb by an average of 0.06 Nm/kg (p=0.001, d=0.219) and landed with greater force on the dominant limb during DLDL by an average of 20% bodyweight (p&lt;0.001, d=0.377). No asymmetries involving knee kinematics were identified. During DLDL, both limbs demonstrated similar significant correlations between knee (peak) and ankle (@IC and peak) kinematics and peak VGRF. During nondominant SLDL, knee@IC, peak knee flexion, and peak dorsiflexion significantly correlated to peak VGRF. Peak knee flexion during non-dominant SLDL correlated to non-dominant KES. Conclusions Knee mechanics are important components for shock attenuation, but for this population, factors other than strength likely play a more significant role in controlling the mechanics about the knee during landing tasks.

Bipolar direct current (DC) microgrids have emerged as a promising alternative for efficiently integrating of renewable energy sources. However, these systems are susceptible to voltage imbalance between the positive and negative poles, especially with asymmetric loads. This paper presents the modeling and control of a non-isolated DC–DC Boost converter with a symmetric bipolar output suitable for photovoltaic applications. The proposed topology eliminates issues related to voltage imbalance and leakage currents while providing continuous low-ripple input current, a reduced number of components, simplified operation, and common grounding with the output neutral point. The operating principle, modeling, and control strategy of the converter are discussed, and its performance is validated through simulations and experimental results from a 1500 W prototype. The results demonstrate stable operation under both balanced and unbalanced conditions.

Introduction: Knee Osteoarthritis (KOA) plays a substantial role in the global burden of musculoskeletal disorders. Biomechanical factors such as leg dominance are hypothesised to contribute to the onset and progression of KOA; however, the relationship between dominant limb use and symptom development remains unclear. Aim: To investigate the association between leg dominance and the onset and side of symptoms in KOA, utilising both a validated questionnaire and standardised functional task assessments. Materials and Methods: A cross-sectional study was conducted at the Department of Sports Physiotherapy, KLE Institute of Physiotherapy, Belagavi, Karnataka, India, over 11 months, from May 2024 to March 2025. It involved 131 individuals aged between 45 and 70 years with radiologically confirmed Grade I or II KOA. Leg dominance was assessed through a standardised questionnaire and six motor tasks. The data collected were compiled in Microsoft Excel and analysed using IBM Statistical Package for the Social Sciences (SPSS) Statistics version 29.0. Chi-square tests and t-tests were used to analyse associations. Results: A total of 131 participants (55 males and 76 females) were included in the final analysis. Right leg dominance was identified in 124 (94.7%) of the participants across all motor tasks, with a high concordance noted in the ball-kicking task between self-report and observation. Right knee pain was more common, reported by 111 (84.7%) participants, and the majority noted a gradual onset of symptoms, with 110 (84%) indicating this pattern. All left-leg dominant individuals were female and exhibited left-sided KOA (p-value &lt;0.001). Sudden onset of symptoms was significantly associated with left-leg dominance, observed in 5 (71.4%) participants (p-value=0.001). Conclusion: The study identified a significant association between leg dominance and both the side and onset of KOA symptoms. Dominant limb mechanics may play a role in asymmetric joint loading and early symptom manifestation. Assessing leg dominance through both self-report and task observation may aid in the early identification of at-risk individuals and support targeted rehabilitation planning.

A Thermo–Hydro–Mechanical (T–H–M) coupled analytical solution for an open-hole under 3D asymmetric loads

High-power, high-efficiency multibeam klystrons (MBKs) serve as essential RF power sources for large-scale accelerator facilities, where high-efficiency energy extraction from multiple beams without reflected electrons is critical for achieving stable and efficient operation. However, in practical MBK designs, the electric field distribution within the output cavity gap often becomes nonuniform due to the asymmetrical loading introduced by the coupling port. This field distortion leads to differentiated beamlet deceleration, resulting in reflected electrons in certain beamlets and degraded RF conversion efficiency. Based on the design of a 3-MW S-band high-efficiency MBK, this work proposes a method to improve electric field uniformity by shifting the ferrule region toward the coupling-port side and by introducing tuning rods on both the coupling-port side and the opposite side, arranged parallel to the beam tunnels. This hybrid design improves the field uniformity in the output gap from 53.8% to 92.1%, thereby enabling optimal beam–wave interactions. 3-D CST/PIC simulations demonstrate that the proposed method increases efficiency from 45.1% to 62.7% compared with a conventional reentrant output cavity. Furthermore, the fabricated new cylindrical reentrant output cavity structure was experimentally evaluated using the perturbation (Slater’s) method, confirming the improved field uniformity and validating the effectiveness of the proposed technique.

Asymmetric loading effects and reinforcement strategies for double-arch tunnels in probabilistic jointed rock masses

Background and objective While sarcopenia is a recognized risk factor for hip fracture, the role of side-to-side lower-limb muscle mass asymmetry in determining fracture laterality remains unclear. This study aimed to investigate whether dual-energy X-ray absorptiometry (DXA)-derived lower-limb muscle mass asymmetry is associated with hip fracture laterality in elderly women. Methods We retrospectively analyzed a cohort of 147 women aged ≥65 years with unilateral hip fractures who underwent DXA. Patients were categorized according to fracture side: left (n = 71) or right (n = 76). Lean mass (L), lean mass plus bone mineral content (LB), fat mass, and muscle indices, including the appendicular skeletal muscle index (ASMI) and skeletal muscle index (SMI), were compared between groups. Inter-limb asymmetry was assessed using left-right differences in lower-limb DXA-derived parameters. Results The left-fracture group demonstrated significantly higher left-leg lean mass plus bone mineral content compared with the right-fracture group (4928.0 ± 1223.3 g vs. 4539.8 ± 873.8 g, p = 0.030). Analysis of inter-limb differences revealed a significant association between fracture laterality and lower-limb lean mass plus bone mineral content asymmetry (p = 0.004). Overall, 62.6% (92/147) of fractures occurred on the side with greater lower-limb lean mass plus bone mineral content. Conclusions In elderly women, hip fractures are more likely to occur on the side with relatively greater lower-limb lean mass plus bone mineral content. These findings suggest that inter-limb muscle mass asymmetry, rather than absolute muscle deficiency alone, may contribute to hip fracture risk, potentially through asymmetric load transmission during falls.

Cervical disc replacement aims to preserve cervical spine motion and reduce the risk of adjacent segment disease. The Rhine cervical disc is a non-articulating, viscoelastic implant designed to replicate the natural biomechanics of the cervical spine. To date, no explant analyses of this device have been published. This study presents the explant analysis of two Rhine cervical discs retrieved from a 41-year-old female patient who had undergone two-level cervical total disc replacement, C4-C5 and C6-C7, for myeloradiculopathy. The implants were removed approximately one year after the surgery due to increasing neck discomfort, recurrent neurological symptoms, and radiographic evidence of osteolysis. Explant analysis was performed on both implants to assess their physical condition and any associated tissue reactions. Both explants were intact, however, notable findings included plastic deformation of the viscoelastic cores, particularly in the upper disc. The direction of shear deformation differed between the explants, anterior in the upper disc and posterior in the lower disc, suggesting asymmetric loading conditions. In addition, osteolysis was observed predominantly at the posterior aspect of the lower disc one year after implantation. These observations highlight deformation of the viscoelastic core in Rhine cervical discs. Whether this finding relates to surgical factors such as implant sizing and positioning, or to implant design itself, improper sizing and malpositioning may contribute to excessive shear forces, core deformation, and poor clinical outcomes. These factors are all important in implant survival and should be carefully considered. The deformation observed in the cores of the explants is consistent with viscoelastic polymer limitations reported in the literature for other viscoelastic cervical discs.

The relationship between the stomatognathic system and postural control, including gait, is a growing area of interdisciplinary research. While some studies suggest a connection between malocclusion and postural imbalances, the effect of occlusal correction on plantar pressure remains underexplored. This study investigates the changes in static and dynamic plantar pressure distribution following the correction of Class II malocclusion. A clinical study was conducted on 100 participants (50 women and 50 men, mean age 24.5 ± 3.2 years) with diagnosed anteroposterior malocclusion (Angle Class II ). Plantar pressure distribution was assessed using a baropodometric platform under static conditions (bipedal stance) and dynamic conditions (gait) both before and after achieving Angle Class I occlusion. Parameters analyzed included the centre of pressure (CoP) path, forefoot/hindfoot weight distribution (%), and pressure symmetry. Following malocclusion correction, a statistically significant improvement in plantar pressure balance was observed. The CoP path length and sway area decreased significantly during static posturography (p &lt; 0.01). The forefoot/hindfoot load distribution became more symmetrical, approaching a physiologically optimal ratio. During gait, pressure analysis revealed a more harmonious and symmetrical pressure distribution across both feet, with a reduction in asymmetrical loading patterns that were present pre-treatment. The correction of Class II malocclusion has a significant positive effect on normalizing both static and dynamic plantar pressure distribution. These findings underscore the existence of a stomatognathic-podal relationship and highlight the importance of a multidisciplinary approach involving dentists and physiotherapists for the comprehensive management of patients with malocclusion.

Abstract Belt conveyors are widely used in bulk material handling, yet system-level observability remains limited. Existing monitoring solutions are typically localized and component-specific, while comprehensive monitoring of distributed components is often impractical. This article presents a belt-integrated monitoring concept that measures tensile loads during operation by instrumenting a belt section with multiple strain-based sensing elements across the belt width. The resulting measurements aim to detect asymmetric load states and load peaks associated with, for example, eccentric bulk material loading, belt mis-tracking, or localized increases in idler rolling resistance. The concept includes an in-belt measurement chain with signal conditioning, data acquisition, and wireless transmission to an external base station for processing and evaluation. Splice-compatible integration using a hot-vulcanized step splice in a fabric conveyor belt was investigated; representative vulcanization temperature and pressure profiles were recorded during splicing of an 11 mm thick belt segment, and the strain-based sensing elements remained functional after curing. Operational validation on an in-house test stand is ongoing.

The increased demand for clean renewable energy requires innovative technology designs. A dual-rotor wind turbine system is presented and modelled using Blade Element Momentum Theory. Four different rotor configurations were analysed in both structural loading and vibrational impact. A key advantage of the dual-rotor approach is its ability to maintain partial operation even if one rotor fails, a feature that could significantly increase wind farm reliability. The study explores contra-rotation as a strategy to mitigate asymmetric lateral loads, thereby reducing torsional and rolling stresses at the tower and beam locations – a critical factor for structural longevity. This investigation analysed the impact of rotor phasing, an area previously unaddressed in the literature, by focussing on system dynamics in both frequency and time domains. Our findings reveal that operating the rotors out of phase can reduce fore-aft vibrations in the connecting beam by up to 86%, without increasing overall structural loads.

Abstract Fatigue and asymmetrical loading can alter gait mechanics, yet their combined effects on knee kinematics during walking remain under-investigated. This single-subject pilot examined how squat-induced fatigue interacts with one-hand load carriage to influence knee flexion, abduction, and internal rotation. Three-dimensional kinematics were collected using a Vicon system, and clinical knee angles were computed with a modified Grood–Suntay joint coordinate system (JCS). The protocol included normal walking (NW), asymmetrical load carriage (farmer's carry, left hand), and postfatigue trials following 25, 50, 75, and 100 body-weight squats. Fatigue was associated with increased flexion variability and greater flexion at heel strike and early stance. Abduction and internal rotation waveforms remained generally consistent across fatigue levels; however, frontal-plane variability was greatest during asymmetrical loading prior to fatigue. Stride-length variability increased markedly in the 100-squat condition, suggesting a faster but less stable gait strategy under maximal fatigue. Together, the results demonstrate joint-specific and phase-dependent adaptations to fatigue and asymmetrical loading. Increased variability, particularly in flexion, likely reflects compensatory mechanisms that redistribute mechanical demand across the lower limb. While preliminary, these findings motivate larger, bilateral studies incorporating kinetics and electromyography (EMG) to refine rehabilitation and ergonomic recommendations for loaded walking.

Abstract Applying cold plates to primary heat sources of high-performance compute (HPC) servers and pumping refrigerant through them is known as pumped two-phase (P2P) liquid cooling. Refrigerant to air (RA) and refrigerant to liquid (RL) versions of P2P direct to chip liquid cooling of HPC IT equipment have been developed, and their performance was evaluated at commercial scale. Matching silicon power map to the cold plate is in the IT manufacturer's domain, necessitating collaboration between thermal capture and transport system designers to optimize P2P. The transport system includes working fluid conveyance from coolant distribution unit (CDU) pump to an array of two-phase cold plates (2PCPs), return to CDU condenser, and back to CDU pump. The condenser transfers heat from the refrigerant to primary fluid, either whitespace air in an air-cooled data center or facility cooling system (FCS) of an economized chiller. Important performance parameters include flow regulation of refrigerant flow to each 2PCP array; stability of CDU operation over zero to 100% IT load and during transient and asymmetric IT loading; and CDU stable operation at startup as server population varies from zero to full population and while hot-swapping servers from racks. Demonstration of safe operation during abnormal conditions including pump switchover and loss of heat rejection is discussed. Lessons learned are included from commissioning P2P CDU and flow conveyance including charging, flushing, and startup. Advantages of P2P in achieving sustainability goals and insights into a Total Cost of Operation (TCO) analysis of RA and refrigerant to water comparing 1P to 2P liquid cooling are discussed.

Pile foundations are critical load-bearing components in bridge structures, particularly in soft, high-moisture soils susceptible to external disturbances. This study investigated the impact of large-scale soil excavation on the stability of adjacent pile foundations through comprehensive field monitoring of a newly constructed bridge during both the bridge construction and channel excavation phases. The close proximity of the excavation site to the pile caps facilitated a detailed assessment of soil–structure interaction. The results indicate that the pile axial force peaked at the pile head and decreased progressively with depth, consistent with the load transfer mechanism of friction piles. Notably, a distinct variation in axial force was observed at the bedrock interface, attributed to reduced relative displacement between the pile and the surrounding soil. Furthermore, channel water filling raised the local groundwater table, which increased the buoyancy and reduced negative skin friction, thereby decreasing the pile axial force. The study also highlighted the sensitivity of pile deformation in soft soil to unbalanced earth pressure. Asymmetric excavation and surface surcharge loading were identified as critical factors compromising pile stability and overall structural safety. These findings provide valuable insights for construction practices and offer effective strategies to mitigate adverse excavation effects, ensuring long-term structural stability.

Netball presents a high incidence of anterior cruciate ligament (ACL) injuries, with evidence suggesting that catching a ball overhead, and lowering it below the pelvis, may exacerbate injury risk. This study investigated the biomechanical effects of ball position on landing mechanics during a 180° rotational countermovement jump. Sixteen female participants (mean age: 17 ± 1 years; height: 167 ± 5.87 cm; weight: 74 ± 17.57 kg) performed jump-landing tasks while holding a ball in four conditions: Down towards the leading limb (Down Leading), trailing limb (Down Trailing), chest-height, and centrally low. Portable VALD force plates and dual-plane video captured landing kinetics and kinematics. Variables included rate of force development (RFD) (N/s/cm), impulse (N.s/cm), and peak vertical ground reaction force (PvGRF) (N/cm), normalised to jump height. Repeated-measures ANOVAs with post hoc tests and Greenhouse-Geisser/Bonferroni corrections determined significance. The Trail limb exhibited consistently higher RFD (1158.17 N/s/cm) and PvGRF (97.55 N/cm) compared to leading (1012.84 N/s/cm, 90.49 N/cm), possibly due to participants braking with their trailing limb when rotating clockwise. Impulse did not differ significantly across conditions. Video analysis suggested low ball positions may have increased valgus knee collapse, trunk rotation, wider landing stance, and temporary loss of balance that required saving actions. A high incidence of failed jumps in moderately experienced (∼8yrs of exposure) players indicates potential need for further training of controlled jump rotation actions. Similarly, the findings highlight the importance of bilateral turning training to mitigate asymmetrical loading and indicates avoiding excessively low-ball positions, which may affect trunk control and balance.