Torque Values Research Articles

Performance Analysis of a Diesel Generator Using Dexlite Mixed Fuel with Bio-Oil Produced from Coffee Grounds Pyrolysis

Coffee grounds are an abundant biomass rarely used and often thrown away for nothing. On the other hand, pyrolysis is an alternative technology for utilizing biomass such as coffee grounds into biochar, syngas, and bio-oil. The bio-oil resulting from pyrolysis can then be mixed with dexlite in a 1:1 ratio, which is then called B50. This paper aims to analyze the performance of a Diesel generator driven by a motor fueled by Dexlite (a Diesel fuel variant that has a minimum CN of 51 and contains a maximum of 1200 ppm sulfur) and a mixture of bio-oil resulting from the pyrolysis of coffee grounds at a temperature of 500 °C with Dexlite (B50), with variations in load power of 300 Watt, 1100 Watt, and 1300 Watt. Generator set performance analysis includes effective power, torque, specific fuel consumption, generator efficiency, and exhaust emissions. At a load of 1300 W with a rotation of 1600 rpm, the maximum effective power obtained is the same, whether the generator is fueled with dexlite or B50, around 1,440 kW. The maximum torque value for dexlite and B50 fuel is 8.6 Nm. The maximum specific fuel consumption (SFC) for dexlite fuel at a load of 300 W at 1600 rpm is 645.25 g/kWh. The maximum air and fuel ratio (AFR) is on the B50 with a load of 300 W at 2000 rpm, which is 1:47. The maximum thermal efficiency is at the B50 at 1600 rpm, around 66.6%. The maximum generator efficiency is 48% with dexlite fuel and B50. Regarding exhaust gas analysis, the maximum CO exhaust emission level is 475 PPM on dexlite. In contrast, the maximum H2S level is 347 PPM on Dexlite, whereas the maximum O2 concentration is 20.6% when the generator operates on B50. The analysis found that the performance of diesel generator engines with B50 fuel was better than pure Dexlite.

The Influence of the Degree of Dental Implant Insertion Compression on Primary Stability Measured by Resonance Frequency and Progressive Insertion Torque: In Vitro Study

Background: This study aimed to evaluate the primary stability, according to the insertion torque value (ITV) and resonance frequency analysis (RFA), of dental implants placed in standardized blocks of bone quality equivalent to type II-A bone, using three surgical undersized protocols of 0.2 mm, 0.5 mm, and 0.8 mm, considering different dental implant diameters and lengths. Methods: One hundred and twenty dental implants (DIs) of different diameters (3.5, 3.8, 4.5, and 5.0 mm) and lengths (8.5, 10.0, 11.5, 13.0, and 15.0 mm) placed in polyurethane blocks equivalent to type II-A bone, according to the Lekholm and Zarb classification modified by Rosas et al., were examined with three surgical protocols of under-milling of 0.2, 0.5, and 0.8 mm. The ITV and the RFA were the determinants of primary stability, and their respective values were recorded as Ncm and the implant stability quotient (ISQ) immediately after the placement of the DIs. These were evaluated according to each surgical insertion protocol, length, and diameter of the DI under a multivariate analysis model (MANOVA). Statistical significance was set at p < 0.05. Results: It was observed that the average of the ITV was significantly higher when a 0.8 mm under-milling protocol was used (63.2 ± 14.9 Ncm) (p < 0.001). However, the ITV was significantly lower when a 0.2 mm under-milling protocol was used (25.1 ± 8.3 Ncm) (p < 0.001). On the other hand, the ISQ did not present significant differences (p = 0.166) when comparing the 0.2 (67.6 ISQ ± 5.4 ISQ), 0.5 (65.8 ISQ ± 3.4 ISQ), and 0.8 (65.7 ISQ ± 4.0 ISQ) under-milling protocols in the evaluation of the primary stability of the dental implant. The multivariate effect size (ηp2 = 0.639) indicated that the variability detected in the insertion torque and the ISQ, at the same time, was explained by 63.9% (p < 0.001) due only to the compression protocol, while the implant diameter explained this variability by 27.0% (ηp2 = 0.270) (p < 0.001) and the implant length only significantly explained this variability by 12.1% (ηp2 = 0.121) (p = 0.030). Finally, any interaction between the compression protocol, implant diameter, and length did not influence insertion torque variability or the ISQ (p > 0.05). Conclusions: It can be concluded that when the surgical protocol for subpreparation is optimal according to the prepared bone bed, regardless of the diameter or length of the dental implant used, primary stability was assured according to the ITV and the RFA in 63.9%. This finding allows us to recommend carrying out a correct analysis of bone quality in order to subsequently select the most appropriate surgical protocol for the subpreparation of the bone bed to achieve better primary stability of the dental implant.

LAUKSAIMNIECĪBAS BERAMKRAVU MATERIĀLU TRANSPORTĒŠANAS GLIEMEŽTRANSPORTIERA JAUDAS PARAMETRU PĒTĪJUMI

The article presents the results of theoretical and experimental laboratory investigations of an improved screw conveyor for bulk agricultural materials that has been created, which, instead of a solid spiral winding, fixed to the drive shaft, uses a spiral winding, formed by separate curvilinear planes (blades), which are also separately fixed to the shaft, yet as a whole form a single spiral. An analytical dependence was obtained for determination of the magnitude of the torque on the drive shaft of this transport working element. The numerical values, obtained as a result of the laboratory experiments, made it possible, when conducting a regression analysis, to derive a new analytical expression in the form of a regression equation. The analysis of the regression equation shows that these factors, which have a significant impact upon the increase in the torque, are the factors: x1 (D) – the diameter of the fixed casing in which the screw is installed and x2 (ψ) – the filling factor of the conveyor with the transported bulk material. Increasing the value of the factor x3(n), i.e., the rotation speed of the vane working body leads to a decrease in the torque value.

Effect of Loading Angles on Abutment Screw Loosening: InVitro Study.

Biomechanical performance is a critical factor in the long-term success of dental implants, with abutment screw loosening being a common clinical issue. This study aimed to examine the impact of abutment screw design and external load loading angles on abutment screw loosening. Abutments and abutment screws with 30°, 60°, 90°, and 180° fitting tapers were fabricated and tested for preload and initial loosening torque. Subsequently, dynamic loosening tests were conducted at loading angles of 15°, 30°, and 45°. Finite element analysis (FEA) was used to calculate the stress and strain distribution of the abutment screws. The findings indicated that large-taper abutment screws exhibit a higher preload, whereas small-taper abutment screws demonstrate greater loosening torque values. Additionally, as the loading angle increases, the loosening torque value decreases, and the stress and strain values of the abutment screw increase. Abutment screws with smaller taper heads exhibited superior resistance to loosening. Moreover, the anti-loosening performance of the abutment screws decreased with higher external load loading angles.

Optimal PI controller parameter setting for torque ripple minimization in SVPWM–DTC based BLDC motor drive using sine cosine algorithm

Abstract This paper focuses on the selection of the most suitable values for the PI controller parameters to minimize the discrepancy between the desired reference values and the actual values of speed and torque in the context of Space Vector Pulse Width Modulation-Direct Torque Control (SVPWM-DTC) of Brushless DC motors (BLDCM). To effectively fine-tune the PI controller, the criteria of Integral of Squared Speed Error (ISSE), Integral of Squared Torque Error (ISTE), and Integral of Squared Flux Error (ISFE) are taken into account as the objective functions across various scenarios. Nevertheless, when it comes to optimizing multiple objective functions, the most optimal approach is to reduce their linear combination. This paper employs JAYA and Sine Cosine algorithms (SCA) for the calibration of the gain parameters of the PI Controller. To assess the effectiveness of the proposed optimal PI controller for SVPWM-DTC of BLDCM, simulations are conducted. According to the findings of the simulations, the Sine Cosine technique yields a remarkable improvement by reducing the torque ripple and controlling the speed peaks overshoot reducing it to 61.6% and 11.9% respectively, and the JAYA algorithm.

Evaluation of Bone Density for Primary Implant Stability Using a Newly Designed Drill: An In Vitro Study on Polyurethane Bone Blocks.

Bone density is an important factor for long-term implant success. Peri-implant bone density evaluation before implant placement can be useful for treatment planning, such as the selection of proper implant size or drilling protocol in each case. In this study, we aimed to establish an objective intraoperative bone density evaluation method by measuring the drilling torque value using a newly designed density measurement drill. Drilling torque value measurement was performed intraoperatively using three types of drills; two previously reported drills and a newly designed drill as a density measurement drill. Polyurethane bone blocks of different densities (D1-D4) were used in this experiment. After the measurement, implants were inserted based on the scheduled plan, and insertion torque (IT) and implant stability quotient (ISQ) were measured to assess primary implant stability. The drilling torque value increased with the bone blocks' density, and there were significant differences among different densities in all groups (p < 0.05). The drilling torque value showed a positive correlation with IT in all groups (p < 0.05). In addition, the drilling torque value increased with the increase in ISQ in all groups. Within the limitations of this study, a newly designed density measurement drill was able to classify D1-D4 in polyurethane bone blocks despite its narrow diameter, and an objective intraoperative bone evaluation can be achieved. An intraoperative assessment of the drilling torque value can predict primary implant stability and provide valuable information for intraoperative treatment planning, such as undersized drilling protocol and implant size change.

Biomechanical evaluation of percutaneous compression plate and femoral neck system in Pauwels type III femoral neck fractures

BackgroundThe optimal treatment for Pauwels type III femoral neck fractures remains contentious. We aim to compare the biomechanical properties of three inverted cannulated compression screw (ICCS), femoral neck system (FNS), and percutaneous compression plate (PCCP) to determine which offers superior stability for unstable femoral neck fractures.Materials and methodsFinite element analysis and artificial bone models were used to establish Pauwels III femoral neck fracture models. They were divided into ICCS, FNS, and PCCP groups based on respective internal fixation assemblies. The models were subjected to vertical axial loads (2100 N) and torsional forces (10 N × mm) along the femoral neck axis in the finite element analysis. The primary outcomes such as the Z axis fragmentary displacements, as well as displacements and the von Mises stress (VMS) distributions of internal fixations, were analyzed. Additionally, the artificial bones were subjected to progressively increasing vertical axial pressures and torsional moments at angles of 2°, 4°, and 6°, respectively. The vertical displacements of femoral heads and the required torque values were recorded.ResultsFinite element analysis revealed that under single-leg stance loading, the maximum Z-axis fragmentary displacements were 5.060 mm for ICCS, 4.028 mm for FNS, and 2.796 mm for PCCP. The maximum displacements of internal fixations were 4.545 mm for ICCS, 3.047 mm for FNS, and 2.559 mm for PCCP. Peak VMS values were 512.21 MPa for ICCS, 242.86 MPa for FNS, and 413.85 MPa for PCCP. Under increasing vertical loads applied to the artificial bones, the average vertical axial stiffness for the ICCS, FNS, and PCCP groups were 244.86 ± 2.84 N/mm, 415.03 ± 27.10 N/mm, and 529.98 ± 23.08 N/mm. For the torsional moment tests, the PCCP group demonstrated significantly higher torque values at 2°, 4°, and 6° compared with FNS and ICCS, with no significant difference between FNS and ICCS (P > 0.05).ConclusionsFinite element analysis and artificial bone models indicated that PCCP offers the best compressive and rotational stability for fixing Pauwels type III femoral neck fractures, followed by FNS and then ICCS. No significant difference in rotational resistance was observed between FNS and ICCS in synthetic bones.Level of Evidence Level 5.

ЕЛЕКТРОМЕХАНІЧНІ ХАРАКТЕРИСТИКИ БЕЗКОНТАКТНОГО ДВИГУНА З ПОСТІЙНИМИ МАГНІТАМИ ПРИ ШИРОТНО-ІМПУЛЬСНОМУ ЖИВЛЕННІ

The paper is devoted to the study of the characteristics and operating modes of a brushless permanent magnet motor in the structure of an electric drive with a two-wire external power supply from a voltage source with pulse-width regulation. The dependences of the motor rotation frequency, the stator current effective value and the average value of the current in the DC link of the voltage inverter, as well as the dependences of the torque coefficient on the average value of the motor torque are given. The influence of the frequency of the pulse supply voltage on the operating modes of the motor is studied. The current and torque limitation modes of the motor in a system with a single-position relay controller and a fixed transistor shutdown interval former are studied. Ref. 12, fig. 16.

Development and invitro testing of an orthodontic miniscrew for use in the mandible.

Temporary anchorage devices (TADs) have been successfully used in the maxilla. However, in the mandible, lower success rates present achallenge in everyday clinical practice. Anew TAD design will be presented that is intended to demonstrate optimization of the coupling structure as well as in the thread area for use in the mandible. Three TADs were examined: (A)Aarhus® system (68.99.33 A, Medicon, Tuttlingen, Germany), (B)BENEfit® orthodontic screw (ST-33-54209; PSM Medical, Gunningen, Germany) and(C) anew design with atwo-part screw thread. The TADs were inserted into artificial bone blocks after predrilling to test primary stability. To test the fracture stability, the TADs were embedded in Technovit® 4004 (Heraeus Kulzer, Wehrheim, Germany) and torsional loaded at an angle of 90° until fracture. The threshold torque values occurring were recorded digitally. The statistical evaluation was carried out using the Kruskal-Wallis test with aposthoc test according to Bonferroni (p < 0.05). The following values were measured for the insertion torque: A: 33.7 ± 3.3 Ncm; B: 57.1 ± 8.4 Ncm; C: 34.2 ± 1.4 Ncm. There were significant differences between A-B andB-C. The measured values for the fracture strength were as follows: A: 46.7 ± 3.5 Ncm; B: 64.2 ± 5.1 Ncm; C: 55.4 ± 5.1 Ncm. Significant differences were found between all groups. The adapted screw design has no negative influence on primary and fracture stability. Whether the design has apositive effect on the success rates in the mandible must be clarified in further clinical studies.

Adoption of Multiphase and Variable Flux Motors in Automotive Applications

This paper investigates the incorporation of multiphase (MP) and variable flux (VF) permanent magnet motors to electric vehicles (EVs). A literature review is carried out first, which covers the characteristics, benefits and challenges of both motor configurations. MP motors, with their increased phase number, offer enhanced fault tolerance, reduced torque ripple, and improved efficiency, among other benefits. VF technology allows for dynamic adjustment of the magnetic field, optimising motor performance across various operating conditions. By integrating these technologies, this study aims to harness the benefits of both MP configurations and VF capabilities. For this reason, the Finite Element Method (FEM) is used with three-phase, MP, VF, and VF-MP motors. The main contribution is that both technologies have been implemented in a single motor to evaluate and quantify their impact together, obtaining higher torque and constant power values, lower torque ripples, and higher efficiencies in the whole working range.

The correlation analysis between the pedicle screw placement palpation and torque

BackgroundThis study endeavored to investigate the influencing factors of pedicle screw torque measured during surgery and the correlation between manual palpation scores and screw torque. MethodsThis investigation was a prospective study designed to gather data from patients who underwent spinal internal fixation performed by the same surgical team at the Department of Orthopedics, affiliated with the First Hospital of Guangzhou University of Chinese Medicine, spanning from January 2020 to September 2023. The sample comprised 51 individuals (18 males and 33 females; mean age: 60.78±11.48 years). All participants underwent bone mineral density (BMD) and comprehensive radiological testing to evaluate the affected spinal segments. Intraoperatively, parameters such as the surgeon's tactile perception, a visual analogue scale for manual palpation, and peak screw torque values were documented. Patients were subsequently stratified into three categories based on the resistance encountered during screw placement. Demographic variables (age, height, weight) and BMD measurements of patients within each category were compared. Factors exhibiting significant differences were subjected to multivariate logistic regression analysis (MLRA). Concurrently, the relationship between manual palpation scores and torque values was examined. ResultsThe results of the univariate analysis indicated that age (P=0.042), height (P=0.047), BMD of the lumbar (P<0.01), BMD of the femoral neck (P=0.02), BMD of the hip (P=0.02), and P1NP (P=0.044) were statistically significant. The results of MLRA revealed that BMD of the lumbar was an independent influencing factor for torque (P=0.000<0.05). Additionally, the manual palpation score and torque value of group A were significantly lower than those of the other two groups (P<0.001). There was a significant positive correlation between the intraoperative screw placement palpation and torque. ConclusionsThe BMD of the lumbar is an independent factor that influences the measured torque applied to pedicle screws during surgery. A significant and robust positive correlation exists between the intraoperative screw placement tactile sensation and the torque experienced. It is advisable to reinforce the screw channel with bone cement when the tactile score is ≤2.5 and the torque is ≤ 1.3 N.m.

Ex Vivo Biomechanical Comparison of Four Techniques to Tibiotarsus Osteosynthesis in Adult Laying Hens (Gallus gallus domesticus).

To assess the biomechanical parameters of intact tibiotarsi (INT) and tibiotarsi with a 5-mm segmental diaphyseal defect repaired using four osteosynthesis techniques: a locking plate (LP), a plate-rod combination, an external skeletal fixator (one end-threaded positive-profile pin per fragment) with an intramedullary pin tie-in (TIF 1), and an external skeletal fixator (two end-threaded positive-profile pins per fragment) with an intramedullary pin tie-in (TIF 2). Sixty tibiotarsi from 30 adult laying hens were allocated into five groups for nondestructive dynamic torsion and four-point bending tests, followed by failure tests. Nondestructive dynamic tests evaluated stiffness over time in torsion and bending. Torsion destructive tests provided maximum torque and rotation values, whereas the four-point bending tests provided the yield load, maximum bending load, and maximum displacement. The INT group showed higher torsional stiffness and maximum torque but similar bending stiffness, torsional strength, and bending strength in one or more groups. LP and TIF 2 exhibited the highest similarity frequencies among the treatment groups, whereas the TIF 1 group displayed lower stiffness and strength for most of the evaluated parameters. Similar results for LP and TIF-2 groups suggest the biomechanical equivalence of these methods for tibiotarsal osteosynthesis in adult hens.

Prior Musculoskeletal Injury and Components of Physical Fitness in Military Personnel: A Systematic Review with Meta-analysis.

Military personnel confront heightened risks of musculoskeletal injuries (MSIs) because of the demanding nature of their duties, contributing to restricted active duty and financial burdens. Although preventable factors like training and physical fitness influence some injuries, understanding the enduring effects of previous MSIs on physical fitness in military personnel remains a critical gap. This study aimed to systematically review and meta-analyze this impact. In accordance with PRISMA guidelines, a systematic review with meta-analysis was conducted, focusing on military personnel with and without a history of MSIs. Physical fitness components were assessed via observational studies, with isokinetic peak torque values as primary metrics. Quality assessments utilized the NIH Quality Assessment Tool and GRADE framework. Out of 36 papers, 6 met inclusion criteria, with 4 included in the meta-analysis. Across 1,267 participants, individuals with prior MSIs exhibited a significant reduction in the pooled effect size for isokinetic peak muscle force, with d+ = -0.25 (95% CI: -0.36 to -0.13), notably affecting knee and shoulder regions. These findings underscore the pervasive impact of MSIs on military personnel's physical performance, necessitating targeted interventions. Military personnel with prior MSIs exhibit enduring deficits in isokinetic peak muscle force, particularly in knee and shoulder regions. However, evidence on the impact of previous injuries on other physical fitness components remains limited. Further research is crucial to understanding the multifaceted impact of MSIs on diverse aspects of physical performance, informing comprehensive injury prevention strategies and optimizing performance outcomes among military personnel.

Analysis of torque variation in bolt fastening on coated steel surfaces

As the number of parts ever increases, the push for automation in assembly processes is intensifying in advanced manufacturing industries. The drive to improve productivity through manufacturing automation is relentless, and minimizing torque variation in automated bolt fastening is crucial for achieving successful assembly. Therefore, a precise understanding of the mechanisms of interfacial friction between bolts and coated steel plates, along with a torque analysis based on the interactions of various involved parameters, is essential. This study examines the interactions between surface topography and mechanical properties of bolts and coated steel plates. We explain three primary friction modes (plowing, sliding, and penetrating) within the defined contact areas and propose a prediction model based on contact mechanics to estimate the frictional torque under the bolt head on coated surfaces. Additionally, we quantitatively evaluate how the proportions of these friction modes change under various axial loads and coating conditions, and how these variations affect torque values. We also assess how variations in key parameters influence changes in friction modes, providing insights into the critical factors that should be monitored for effective control of fastening torque. This study presents methods for analyzing and calculating friction torque, offering guidelines for monitoring bearing surfaces to address bolt topography deviations and solving key industrial challenges in automated assembly.

Investigation of cutting forces of glass sphere reinforced polymer composites

AbstractIn this study, the effects of reinforcement ratio, drill bit material, and drilling process parameters on the cutting forces generated during the drilling of glass sphere‐reinforced polypropylene composites were investigated experimentally. Test specimens were produced by conventional injection‐moulding of glass sphere reinforced polypropylene composite materials at 5 %, 10 % and 20 % wt. ratios. High speed steel, titanium‐coated high‐speed steel, and carbide drill bits with 4 mm diameter were preferred for drilling. In addition, the drilling process was carried out on a 3‐axis computer numeric control milling machine. Three different feed rates of 0.05 mm/rev, 0.10 mm/rev, and 0.15 mm/rev and cutting speeds of 12 m⋅min−1, 16 m⋅min−1, and 20 m⋅min−1 were determined for the drilling process. In addition, Taguchi experimental optimization method, analysis of variance and scanning electron microscopy were used to investigate the morphology of the drilled surface and the wear mechanisms occurring on the drill bit due to the drilling process. The test findings showed that the maximum torque value was 54.64 N⋅mm and the maximum thrust force was 100.43 N. The optimum test parameter for cutting forces was observed as C1D3FR1CS3. Drill parameter had an effect of 40.96 % on thrust force and 36.11 % on torque.

Robust Health Condition Prediction of Helicopter Turboshaft Engines Using Ensemble Machine Learning Models

This paper presents a novel ensemble approach that combines multiple machine-learning algorithms to deliver robust predictions of helicopter turboshaft engine health status (nominal or faulty) using operational data. Engine health is evaluated through the torque margin, defined as the percentage difference between the measured and target torque values. A Gaussian process model is used to estimate the torque margin as a probability distribution function (PDF), and these predictions are incorporated as features into various machine-learning models. These models are then employed to perform binary classification, determining the engine's health state. To enhance performance, a reference set is defined for each unseen data point, allowing a comparison of the relative performances of the models, with the best performer selected for the final prediction. Our ensemble method achieves high accuracy in health classification while providing precise torque margin estimates. The results demonstrate that ensemble models offer superior generalization and reliability compared to individual machine-learning algorithms, especially when applied to complex, multivariate datasets like those from helicopter turboshaft engines.

Influence of halloysite nanotubes on processing, structural and thermal properties of poly(vinyl chloride)/high-density polyethylene composites with wood flour

ABSTRACT The aim of this work was to investigate the effect of halloysite nanotubes (HNT) on the processing, structural and thermal properties of poly(vinyl chloride) (PVC), high-density polyethylene (HDPE), and PVC–HDPE composites with various proportions of both polymer components containing 30 wt% wood flour (WF) and 5 wt% halloysite processed in the Brabender measuring mixer. The HNT content in the composites leads to a slight increase in the maximum torque and a reduction in the gelation time for PVC and PVC–HDPE matrix composites with the 90:10 component ratio. In addition, microscopic images of these materials showed a homogeneous distribution of HNT in the polymer matrix. The addition of mineral filler to the matrix, regardless of the polymer type, resulted in a slight increase in the torque values at the kneading endpoint. The PVC–HDPE–wood flour composites are characterized by higher thermal stability at processing temperature when HNT is loaded. The introduction of 5 wt% HNT into the PVC–HDPE 90:10 30 wt% WF blend resulted in an increase of the 2% weight loss temperature by 16°C. The simultaneous use of wood flour and halloysite as fillers for PVC–HDPE blends could be an eco-efficient solution for the new composite material sector.

Integrating machine learning for predicting biomechanical properties of layered manufactured bone implants

AbstractThe layered manufacturing (LM) based locking bone plates (LBPs) are highly favored for biomedical applications due to its implant customization flexibility, control over porosity, and functional parameters. Design of experiments mainly relies on predefined experimental run orders; however, machine learning (ML) can handle complex and nonlinear relationships for predicting output responses. This research investigates the application of various ML models for predicting the impact strength, torque values, and punch shear strength of poly lactic acid (PLA) based LBPs. A dataset of 100 data points for each response variable was developed, analyzing the influence of printing parameters, like infill density (ID), layer height (LH), wall thickness (WT), and print speed (PS). The ID, LH, WT, and PS were varied within the ranges of 20%–100%, 0.1–0.5 mm, 0.4–1.2 mm, and 20–100 mm/s, respectively. Among the ML models evaluated, XGBoost and Adaboost exhibited strong alignment of the predicted values with actual values. The decision tree regression, showed the lowest predictive accuracy due to its tendency to overfit and lack of iterative refinement. The findings suggest that ML models can effectively predict the mechanical properties of PLA‐based LBPs, offering valuable insights for optimizing printing parameters to enhance the performance of orthopedic implants. The findings can guide biomedical engineers in making data‐driven decisions to enhance the strength of LBPs, thereby improving patient outcomes in orthopedic treatments.Highlights Predicted impact strength, torque, and shear strength of biomedical specimens. Evaluated 100 data points per variable to assess printing parameters' influence. XGBoost and Adaboost showed superior accuracy, with R2 consistently above 0.9. Decision Tree regression exhibited the lowest accuracy due to overfitting issues. Aims to guide biomedical engineers in data‐driven decisions for better patient outcomes.

Lateralization has minimal biomechanical impact on tuberosity fixation with the use of a stem-based repair and a 135o humeral implant in reverse shoulder arthroplasty for four-part proximal humerus fracture

IntroductionLateralization in reverse shoulder arthroplasty (RSA) has many proven and potential benefits. Concern over the increase in tension on the tuberosities imparted by glenoid lateralization and the subsequent effect on tuberosity healing may limit its use in the setting of RSA performed for fracture. This study evaluated whether glenoid lateralization increased tuberosity fracture gapping in a biomechanical model of a 4-part proximal humerus fracture with a stem-based tuberosity repair. We hypothesized that increased lateralization would increase fracture gapping. Materials and MethodsEight cadaveric shoulders (mean age, 62 +/- 2.4 years; range 52-70 years) were tested with a custom testing system that permits loading of rotator cuff muscles and humerothoracic muscles. A four-part proximal humerus fracture was simulated and then repaired with a stem-based tuberosity repair. The repaired tuberosities were cycled in internal and external rotation with 1.1Nm torque at 2 mm and 6 mm of glenoid lateralization. For the 6mm lateralization RSA, the torque was then increased to reach the range of motion values achieved with the 2mm lateralized RSA and cycled 10 times, followed by doubling the torque values for 10 cycles. Range of motion, muscle length and fracture gapping were assessed at 2 mm and 6 mm of glenoid lateralization. ResultsInternal rotation and total ROM demonstrated a significant decrease in the 6 mm RSA when compared to the 2 mm RSA (p < 0.05). The 6 mm lateralized RSA significantly increased rotator cuff muscle lengths when compared to the 2 mm lateralized RSA condition except for infraspinatus by an average of 2.7 ± 1.9mm (p < 0.05). There was no significant gapping of the proximal fracture for any condition. There was a significant increase in the gapping of the distal fracture gap in the 6 mm lateralized component condition only after 10 cycles of doubled rotational torque, which measured 1.9 ± 1.5mm (p = .031). DiscussionWe hypothesized that lateralization would increase fracture gapping. Fracture gapping did not occur proximally and only occurred at a slight amount distally after 10 cycles of doubled rotational torque. This may have implications on the choice of glenoid components when performing a RSA for fracture.

Aerodynamic Performance and Numerical Validation Study of a Scaled-Down and Full-Scale Wind Turbine Models

Understanding the aerodynamic performance of scaled-down models is vital for providing crucial insights into wind energy optimization. In this study, the aerodynamic performance of a scaled-down model (12%) was investigated. This validates the findings of the unsteady aerodynamic experiment (UAE) test sequence H. UAE tests provide information on the configuration and conditions of wind tunnel testing to measure the pressure coefficient distribution on the blade surface and the aerodynamic performance of the wind turbine. The computational simulations used shear stress transport and kinetic energy (SST K-Omega) and transitional shear stress transport (SST) turbulence models, with wind speeds ranging from 5 m/s to 25 m/s for the National Renewable Energy Laboratory (NREL) Phase VI and 4 m/s to 14 m/s for the 12% scaled-down model. The aerodynamic performance of both cases was assessed at representative wind speeds of 7 m/s for low, 10 m/s for medium, and 20 m/s for high flow speeds for NREL Phase VI and 7 m/s for low, 9 m/s medium, and 12 m/s for the scaled-down model. The results of the SST K-Omega and transitional SST models were aligned with experimental test measurement data at low wind speeds. However, the SST K-Omega torque values exhibited a slight deviation. The transitional SST and SST K-Omega models yielded aerodynamic properties that were comparable to those of the 12% scaled-down model. The torque values obtained from the simulation for the full-scale NREL Phase VI and the scaled-down model were 1686.5 Nm and 0.8349 Nm, respectively. Both turbulence models reliably predicted torque and pressure coefficient values that were consistent with the experimental data, considering specific flow regimes. The pressure coefficient was maximum at the leading edge of the wind turbine blade on the windward side and minimum on the leeward side. For the 12% scaled-down model, the flow simulation results bordering the low-pressure region of the blade varied slightly.