Nm Of Torque Research Articles

Torsion is a Dynamic Regulator of DNA Replication Stalling and Reactivation.

The inherent helical structure of DNA dictates that a replisome must rotate relative to DNA during replication, presenting inevitable topological challenges to replication. However, little is known about how the replisome progresses against torsional stress. Here, we developed a label-free, high-resolution, real-time assay to monitor replisome movement under torsion. We visualized the replisome rotation of DNA and determined how the replisome slows down under torsion. We found that while helicase or DNA polymerase (DNAP) individually is a weak torsional motor, the replisome composed of both enzymes is the most powerful DNA torsional motor studied to date. It generates ~ 22 pN·nm of torque before stalling, twice the stall torque of E. coli RNA polymerase. Upon replisome stalling, the specific interaction between helicase and DNAP stabilizes the fork junction; without it, the fork can regress hundreds of base pairs. We also discovered that prolonged torsion-induced stalling inactivates the replisome. Surprisingly, DNAP exchange, mediated by the helicase, is highly effective in facilitating replication restart, but only if excess DNAP is present during stalling. Thus, helicase and DNA polymerase work synergistically as a powerful torsional motor, and their dynamic and fluid interactions are crucial for maintaining fork integrity under torsional stress. This work demonstrates that torsion is a strong regulator of DNA replication stalling and reactivation.

Numerical Study on the Influence of Torque Performance Caused by Deflectors on Darrieus Wind Turbines

This paper investigates the effects on the torque performance caused by deflectors of the Darrieus turbine. Various deflectors were placed in front of the turbine and disrupted the wind flow before it came into contact with the turbine blades. Using numerical method, this study aims to find the deflector’s optimum geometric shape, offset distance, and dimension required for the turbine to produce the highest torque. This study utilizes flow simulation analysis to simulate the deflector effect on Darrieus turbine. The result of this study is the optimum deflector geometry and offset distance for producing highest turbine torque output. From the data gathered it is shown that a deflector with triangular cross-section with the size of turbine diameter placed 400 mm offset to the right of the turbine produces the best result. Turbine with this deflector configuration produces 1.24 Nm of torque, eight times higher than its non-deflector counterpart yields 0.14 Nm.

THE ANALYSIS OF PORTING AND POLISHING RESULTS AGAINST MOTORCYCLE TORQUE 150 cm3

The purpose of this study is to investigate the torque results on standard and modified vehicles, presenting torque comparison graphs for standard and modified motorcycle engines. The experimental study used a 150cm3 motorcycle, analyzing the experimental results directly. The study shows the difference in performance, especially torque, across all engine variations at every 500rpm. The study involved porting and polishing modifications to increase engine torque, resulting in a 4.8% increase in torque over standard. The modifications widened the torque range, providing improved performance across a wide range of speeds. The modified motorcycle exhibited faster acceleration, navigating the terrain and heavy traffic with ease. Improved performance at high speeds, stability and temperature maintenance were observed. The porting and polishing modifications had a positive impact on engine torque throughout 6500 to 9000rpm, with 6500 rpm porting A and polishing B displaying optimal results, achieving 14.4Nm of torque, an increase of 0.8Nm over standard conditions.

Bilateral External Torque CT Reliably Detects Syndesmotic Lesions in an Experimental Cadaveric Study.

If tibiofibular syndesmotic injury is undetected, chronic instability may lead to persistent pain and osteoarthritis. So far, no reliable diagnostic method has been available. The primary objectives of this study were to determine whether defined lesions of the syndesmosis can be correlated with specific tibiofibular joint displacements caused by external rotational torque and to compare the performance of bilateral external torque computed tomography (BET-CT) and arthroscopy. Secondary objectives included an evaluation of the reliability of CT measurements and the suitability of the healthy contralateral ankle as a reference. Seven pairs of healthy, cadaveric lower legs were tested and assigned to 2 groups: (1) supination-external rotation (SER) and (2) pronation-external rotation (PER). In the intact state and after each surgical step, an ankle arthroscopy and 3 CT scans were performed. During the scans, the specimens were placed in an external torque device with 2.5, 5.0, and 7.5 Nm of torque applied. The arthroscopic and CT parameters showed significant correlations in all pairwise comparisons. The receiver operating characteristic (ROC) curve analyses yielded the best prediction of syndesmotic instability with the anterior tibiofibular distance on CT, with a sensitivity of 84.1% and a specificity of 95.2% (area under the curve [AUC], 94.8%; 95% confidence interval [CI], 0.916 to 0.979; p < 0.0001) and with the middle tibiofibular distance on arthroscopy, with a sensitivity of 76.2% and specificity of 92.3% (AUC, 91.2%; 95% CI, 0.837 to 0.987; p < 0.0001). Higher torque amounts increased the rate of true-positive results. BET-CT reliably detects experimental syndesmotic rotational instability, compared with the healthy side, with greater sensitivity and similar specificity compared with the arthroscopic lateral hook test. Translation of these experimental findings to clinical practice remains to be established. Diagnostic Level III . See Instructions for Authors for a complete description of levels of evidence.

Selection of Propulsion System for Electric Amphibious Bus to Alleviate Traffic Congestion in the Jabodetabek Area

High vehicle growth in Jakarta is not balanced with traffic growth, the level of congestion in Jakarta continues to increase every year. To overcome this congestion, innovation is needed to utilize the river as a means of public transportation. The amphibious bus is an alternative public transportation option in the Jabodetabek area to break congestion. The amphibious bus design must be supported by a propulsion system that can operate on land and water. The amphibious bus propulsion system is a must, according to river conditions and operational requirements. The selection of the drive system is carried out by means of analysis The driving criteria factors needed according to the specifications of the amphibious bus are power, efficiency, size, cost, and maneuverability. These criteria become indicators in determining the type of mover. This study aims to select the prime mover system based on criteria and specification requirements. The selection uses the process hierarchy analysis (AHP) method by giving weight to the criteria for each driver, and type of mover in the water, namely waterjets, azimuth-podded, Paddle Wheels, Cycloidal Propellers and propulsion on land diesel engines, gasoline engines, and electric engines. The results showed that the order of the propulsion selection criteria was propulsion power being the top priority, followed by maneuverability, energy efficiency, cost, operational and investment, and propulsion size and weight. The results of the AHP show that the main options are propulsion systems in water, namely waterjets and diesel engine propulsion systems on land. System Water Jet has a propulsion power of 1000 kW, has high maneuverability, energy efficiency of 85%, and a maximum speed of 60 Km/hour so it can meet the specifications of an amphibious bus drive. For operations on land, the main choice of propulsion system for amphibious buses is a diesel engine with a power of 250 HP and 800 Nm of torque providing strong torque and a wide cruising range. This system has a range of up to 800 km, a maximum speed of 120 km/h, and exhaust emissions of Euro 5.

Pengaruh Dampak Variasi Piston Diameter 58 ML Dan 52 ML Terhadap Kinerja Motor Matic 4 Tak 110

This research was conducted to determine the effect or impact of variations in the size of a standard piston diameter (52 ML) with a piston with a diameter of 58 ML on a Yamaha Mio motorbike using a dyno test. The results we got from the dyno test, the power or horsepower (HP) produced from a motorbike with a standard 52 ML piston size is 7.44 HP at Rpm 7000 and a torque of 8.72 Nm. Meanwhile, the modified motor with a 58 ML piston produces 11.37 HP at 7000 Rpm and 11.10 Nm of torque. And it can be concluded that motors with factory original standard pistons measuring 52 ML have much lower torque and power than modified pistons measuring 58 ML and the fuel consumption of motors with modified pistons will be more or more wasteful.

Adaptive position control of DC motor for brush-based Adaptive position control of DC motor for brush-based

In this paper, we have developed an automatic brush-based PV cleaning system to control and synchronize the 3 motors together with a smooth periodic of cleaning while moving it horizontally over the PV surface. The mechanical design involved installing linear guides at the top and bottom of the rail to support the aluminium plate that holds the carrier motors and rotating brush. Two different movements of translational and rotational motion of the motors are managed by an algorithm programmed in Arduino Mega. In investigating the performance of motor parameters and dust removal rate, we conducted an experiment by spreading dry sand over the PV surface. Results showed that the torque of the cleaning brush motor increases with the increase in load. The obtained torque of the carrier motor was found to be 9.167 Nm ( stall torque, 9.8 Nm) with a full load of 18 brushes. The torque is inversely proportional to the speed but directly proportional to power. The required power to move the 2.93 kg of cleaning system was 19.20 W with 3.015 Nm of torque. The system achieved 86.8% of the dust removal rate from the four cycles of cleaning operations.

A Comparison Study of Hydro-Compact Generators with Horizontal Spiral Turbines (HSTs) and a Three-Blade Turbine Used in Irrigation Canals

This study aimed to present the experimental results of two types of turbines and attachments used in a hydro-compact generator. Two Horizontal Spiral Turbines (HSTs) with blade angles of eighteen and twenty-one degrees, respectively, and a three-blade turbine were tested and experimented in a laboratory at five levels of water flow rate ranging from 1–2 m/s. After the efficiency and torque values of each turbine were identified, they were installed in two 200 W power generator systems: (1) with a “diffuser” attachment; and (2) with an “in-line+diffuser+nozzle chamber” attachment, and tested in a local irrigation canal with 1.2 m/s. The results from the laboratory indicated that the HST with a twenty-one degree blade angle had 38.10% efficiency at the water flow rate of 2 m/s. It could reach 120.0 rpm and produced 212 Nm of torque. The results from the field experiment revealed that the combination of the power generator with the twenty-one degree blade angle HST and the in-line + diffuser + nozzle chamber attachment was the most efficient, with 284 Nm of torque at 108 rpm and could generate 67.63 W of electrical power. When the water flow rate of the irrigation canal reached 1.5 m/s, it could reach 114 rpm and generate 129.2 W. This hydro-compact generator set is suitable for irrigation canals with a water flow rate ranging from 1–1.5 m/s.

Application of electrolaminates for the development of biomimetic morphing unmanned aerial vehicles

Morphing aircraft offer the promise of performance that can be optimized for a range of flight profiles. But such capability places challenging demands on the morphing system that cannot easily be met with conventional actuators or smart materials. Electrolaminates use electrostatic forces controlled by the application of a voltage (typically high-voltage but extremely low-current) to controllably bond or unbond layers of a laminated composite structure together. Such on-demand bonding can be used to effectively change the stiffness of the structure or control elongation or twist of the structure. This technology has multiple benefits compared to other smart material or conventional actuator-driven approaches; it is thin and light, has very low energy requirements, and offers rapid response capabilities controlled by simple electronics. These capabilities can enable bio-inspired morphing with large numbers of degrees of freedom and high spatial resolution. We designed, fabricated, and tested a fully functional morphing-wing unmanned aerial vehicle (UAV) with telescoping wings and a splaying, bird-like tail enabled by electrolaminates. Key features of the current UAV configuration include: a variable wingspan of 1.2–2.4 m with a corresponding change in the wing area of nearly a factor of four; no vertical tail; and a horizontal tail area variable by a factor of three. The ability to asymmetrically control the tail area allows for independent pitch and body circulation control. The tail area is changed by a separate electrolaminate clamping mechanism. The variable-area tail uses ‘feathers’ that can be overlapped or splayed as needed. The practical shape-changing is enabled by electrolaminate materials that can rapidly lock the orientation of the feathers. The electrolaminate clutches support more than 5 nm of torque and are sufficient to resist expected flight loads. We also designed, fabricated, and tested other morphing-wing designs enabled by electrolaminate technology to create a wing with smoothly sliding skin that is capable of changing chord and camber with a single linear actuator. Our results suggest that electrolaminates can practically enable bio-inspired, small (Group 1 and 2) morphing UAVs.

Studi Eksperimental Pengaruh Variasi Sudut Kemiringan Poros Terhadap Kinerja Turbin Ulir Archimedes

This study aims to design and conduct an experimental study of axle tilt angles variation on the performance of the Archimedes screw turbine (AST). The AST was constructed based on Rorres (2000) [3] formulation to achieve the optimum design of AST. This design was obtained with the followings parameters: 1.7m turbine axle length, 0.069m and 0.128m of internal and external turbine radius, 0.260m pitch length, 6.5 pitches number, 59° and 72° of external and internal blade angel, and 2 number of blades. The screw turbine performance was experimentally carried out by varying the angle of the turbine axle in the range of 25°, 30°, 35°, 40°, and 45°. The test was utilized the natural river flow with an average discharge of 0.011 m3/s. The result was yielded that the optimum angle of the turbine was at a turbine tilt axle of 35° while the rotational speed was 265.5 rpm, whereby the turbine generated 48.81W power and 4.09Nm of torque. This study is hopefully beneficial for the turbine design reference as well as its experimental evaluation.

ELECTROPLATING DRYING TIME MINIMIZATION THROUGH BOLT DRYER MACHINE

One of the steps after the electroplating/coating process on the product is the drying process. In Micro, Small and Medium Enterprises, the drying process on CIV KG 0741 bolts with a diameter of 10 mm and a length of 20 mm requires a drying time of 6 hours. Drying simply and naturally has limitations, requiring a large drying area depending on the weather, time and temperature, which cannot be controlled. A simple automatic dryer is needed using a single-phase electric power source and simple and ergonomic maintenance methods to obtain a quality product with a measurable drying duration. Design and analysis of drying on the dryer. The dryer with dimensions of 680 x 480 x 967.12 mm3 has a mass of 21.94 kg with a drum capacity of 20 kg. The motor propulsion used is 1 HP, 5.08 Nm of torque and capable of rotating at 1500 rpm with an effort of 39296.66 Joules. The dryer can dry as much as 20 kg of bolts in 5 minutes faster than solar energy, with a drying time of 15 minutes to 1 hour.

Design of a Wearable Mechanism With Shape Memory Alloy (SMA)-Based Artificial Muscle for Assisting With Shoulder Abduction

This letter proposes a new mechanism, a four-bar linkage-based support hinge mechanism, for assisting with shoulder abduction with artificial muscle based on a shape memory alloy (SMA). An artificial muscle using the SMA coils is designed to lighten the entire system and support the wearer's movement both actively and passively. It can generate up to 273 N and 180 N with and without energy input, respectively, while weighing only 0.04 kg. Furthermore, to consider the rotation axis shifts of the arm during shoulder abduction, the trajectory of the arm along the shoulder abduction is modeled using the scapulohumeral rhythm, a combined movement of the scapula and humerus. The mechanism is designed to follow the modeled arm trajectory and achieve the required torque to perform shoulder abduction based on a four-bar linkage mechanism. It can generate up to 10.1 Nm and 6.3 Nm of torque with and without energy input, respectively. To verify the assistive effect of the proposed mechanism, electromyography is measured while performing the same exercise requiring shoulder abduction with and without the support of the mechanism. The results show that the proposed mechanism reduces not only muscle load but also fatigue while performing the shoulder abduction.

Investigation on parallel hybrid electric bicycle along with issuer management system for mountainous region

The performance of electric bicycles for the mountainous region depends on a simulation model and experimental study covers dynamic characteristics, power requirement to propel the electric cycle, and different operating conditions such as slope gradient, a mass of the user, wind speed, wheel diameter, and length of the crankshaft. The study highlights the mathematical model of the electric bicycle with dynamic characteristics and calculates the power required to propel the cycle in the mountainous region under a parallel hybrid mode. The application is supported with an android operating system, which keeps track of the cycle issued to potential users. The system has a mechanism in place, which issues the cycle to only those users who unblock it through the application by scanning the correct quick response code. The Simulink is used for mathematical model development and analyzing dynamic characteristics of the electric bicycle. The dSPACE development board framework is used for the experimental validation as a solver to capture multiple input-output parameters. The results show that an electric bicycle motor generates 23.87 Nm of torque at 8 km/h and requires 240 W of power to propel the electric cycle at 34 km/h. The electric bicycle consumes an average current of 8.2 A at a zero slope gradient. It also shows that required power changes to 260 W at 2.9o slope gradient, 310 W at 4.8o slope gradient and 350 W at 7.1o slope gradient.

Capsular Mechanics After Periacetabular Osteotomy for Hip Dysplasia.

Hip dysplasia is characterized by insufficient acetabular coverage around the femoral head, which leads to instability, pain, and injury. Periacetabular osteotomy (PAO) aims to restore acetabular coverage and function, but its effects on capsular mechanics and joint stability are still unclear. The purpose of this study was to examine the effects of PAO on capsular mechanics and joint range of motion in dysplastic hips. Twelve cadaveric dysplastic hips (denuded to bone and capsule) were mounted onto a robotic tester and tested in multiple positions: (1) full extension, (2) neutral 0°, (3) flexion of 30°, (4) flexion of 60°, and (5) flexion of 90°. In each position, the hips underwent internal and external rotation, abduction, and adduction using 5 Nm of torque. Each hip then underwent PAO to reorient the acetabular fragment, preserving the capsular ligaments, and was retested. The PAO reduced internal rotation in flexion of 90° (∆IR = -5°; p = 0.003), and increased external rotation in flexion of 60° (∆ER = +7°; p = 0.001) and flexion of 90° (∆ER = +11°; p = 0.001). The PAO also reduced abduction in extension (∆ABD = -10°; p = 0.002), neutral 0° (∆ABD = -7°; p = 0.001), and flexion of 30° (∆ABD = -8°; p = 0.001), but increased adduction in neutral 0° (∆ADD = +9°; p = 0.001), flexion of 30° (∆ADD = +11°; p = 0.002), and flexion of 60° (∆ADD = +11°; p = 0.003). PAO caused reductions in hip abduction and internal rotation but greater increases in hip adduction and external rotation. The osseous acetabular structure and capsule both play a role in the balance between joint mobility and stability after PAO.

Use of portable ultrasonography for the diagnosis of lateral ankle instability.

Portable ultrasonography is increasingly used to evaluate ankle stability at the point of care. This study aims to determine the correlation of portable-ultrasonographic and fluoroscopic measurements of ankle laxity in a cadaveric ligament transection model of ankle ligament injury. We hypothesize that there is an association between portable-ultrasonographic and fluoroscopic measurements when performing stress evaluation of lateral ankle instability. Eight fresh-frozen below-knee amputated cadaveric specimens with intact proximal fibula underwent ultrasound and fluoroscopic evaluation of the ankle during anterior drawer and talar tilt testing. The assessment was first performed with all lateral ankle ligaments intact and thereafter with sequential transection of the anterior talofibular ligament, calcaneofibular ligament, and posterior talofibular ligament. The anterior drawer test was performed with both 50N and 80N of force, and talar tilt test was performed with 1.7 Nm of torque. Correlations between (1) portable-ultrasonographic and fluoroscopic measurements and (2) sequential transection of lateral ankle ligaments were evaluated using Spearman's rank correlations. The same statistical test was used to investigate the correlation between the ultrasonographic and the fluoroscopic measurements. The inter- and intra-observer agreement was assessed using the intraclass correlation coefficient through a two-way mixed-effects model with absolute agreement. Portable-ultrasonographic and fluoroscopic measurements increased as additional ligaments of the lateral ankle were transected (Spearman's rank correlation ranged from 0.74 to 0.81, 0.74 to 0.81, p-values < 0.001). Strong positive correlations between ultrasonographic and fluoroscopic measurements were found during the lateral ankle stability evaluation using anterior drawer and talar tilt testing (Spearman's rank correlation ranged from 0.81 to 0.85, 0.81 to 0.85, p-values < 0.001). Inter-rater (0.99, 95% CI: 0.98-0.99) and intra-rater reliability (0.97, 95% CI: 0.95-0.99) for the ultrasonographic measurements were substantial. In conclusion, there was a strong correlation found between ultrasonographic and fluoroscopic values measured during simulated anterior drawer and talar tilt test in a cadaveric ligament transection model. In this model, the portable-ultrasonographic measurement was found to be reliable for repeated measurements of the talar translation and the lateral clear space distance. Based on these data, ultrasonography is likely to become a valuable point of care diagnostic tool due to its ability to readily and dynamically evaluate suspected lateral ankle instability. Clinical Significance: The use of dynamic stress ultrasound to assess the anterior translation of the talus and the lateral clear space distance appears to be a reliable and repeatable technique to evaluate lateral ankle stability with a radiation-free, noninvasive, and low-cost manner.

Stability Evaluation of Different Oblique Lumbar Interbody Fusion Constructs in Normal and Osteoporotic Condition - A Finite Element Based Study.

Introduction: In developed countries, the age structure of the population is currently undergoing an upward shift, resulting a decrease in general bone quality and surgical durability. Over the past decade, oblique lumbar interbody fusion (OLIF) has been globally accepted as a minimally invasive surgical technique. There are several stabilization options available for OLIF cage fixation such as self-anchored stand-alone (SSA), lateral plate-screw (LPS), and bilateral pedicle screw (BPS) systems. The constructs’ stability are crucial for the immediate and long-term success of the surgery. The aim of this study is to investigate the biomechanical effect of the aforementioned constructs, using finite element analysis with different bone qualities (osteoporotic and normal). Method: A bi-segmental (L2–L4) finite element (FE) model was created, using a CT scan of a 24-year-old healthy male. After the FE model validation, CAD geometries of the implants were inserted into the L3–L4 motion segment during a virtual surgery. For the simulations, a 150 N follower load was applied on the models, then 10 Nm of torque was used in six general directions (flexion, extension, right/left bending, and right/left rotation), with different bone material properties. Results: The smallest segmental (L3–L4) ROM (range of motion) was observed in the BPS system, except for right bending. Osteoporosis increased ROMs in all constructs, especially in the LPS system (right bending increase: 140.26%). Osteoporosis also increased the caudal displacement of the implanted cage in all models (healthy bone: 0.06 ± 0.03 mm, osteoporosis: 0.106 ± 0.07 mm), particularly with right bending, where the displacement doubled in SSA and LPS constructs. The displacement of the screws inside the L4 vertebra increased by 59% on average (59.33 ± 21.53%) due to osteoporosis (100% in LPS, rotation). BPS-L4 screw displacements were the least affected by osteoporosis. Conclusions: The investigated constructs provide different levels of stability to the spine depending on the quality of the bone, which can affect the outcome of the surgery. In our model, the BPS system was found to be the most stable construct in osteoporosis. The presented model, after further development, has the potential to help the surgeon in planning a particular spinal surgery by adjusting the stabilization type to the patient’s bone quality.

RANCANG BANGUN MESIN PEMBERSIH GULMA SEMI OTOMATIS

Farmers in Indonesia currently still use traditional tools to cut weeds because they are cheaper. However, it has many drawbacks, including taking a long time and a lot of manpower. Therefore this research is to create a weed cleaning machine with a cheaper and more efficient cost. In the research, the design of the semi-automatic weed cleaning machine was carried out and after that the performance testing of the tool was carried out. From the test, it was concluded that in this study, a semi-automatic weed cleaning machine has been successfully built with an engine power of 401.9 W or 0.538 HP, 6.4 Nm of torque and gasoline. Semi Automatic weed cutting machine capable of cutting weeds for an area of 1 hectare takes an average of 34.7 hours with a manufacturing cost of Rp.2.225.000.

Reducing Metabolic Cost During Planetary Ambulation Using Robotic Actuation.

INTRODUCTION: Current spacesuits are cumbersome and metabolically expensive. The use of robotic actuators could improve extravehicular activity performance. We propose a novel method to quantify the benefit of robotic actuators during planetary ambulation.METHODS: Using the OpenSim framework, we completed a biomechanical analysis of three walking conditions: unsuited, suited with the extravehicular mobility unit (EMU) spacesuit (represented as external joint torques applied to human joints), and suited with the EMU and assisted by robotic actuators capable of producing up to 10 Nm of torque. For each scenario, we calculated the inverse kinematics and inverse dynamics of the lower body joints (hip, knee, and ankle). We also determined the activation of muscles and robotic actuators (when present). Finally, from inverse dynamics and muscle activation results, the metabolic cost of one gait cycle was calculated in all three conditions.RESULTS: The moments of lower body joints increased due to the increased resistance to movement from the spacesuit. The additional torque increased the overall metabolic cost by 85 compared to the unsuited condition. The assistive robotic actuators were able to reduce the metabolic cost induced by EMU resistance by 15.DISCUSSION: Our model indicates that the majority of metabolic cost reduction can be attributed to the actuators located at the hip. The robotic actuators reduced metabolic cost similar to that of modern-day actuators used to improve walking. During a Mars mission, the actuators could save one crewmember up to 100,000 kilocal on one 539-d planetary expedition.Kluis L, Keller N, Bai H, Iyengar N, Shepherd R, Diaz-Artiles A. Reducing metabolic cost during planetary ambulation using robotic actuation. Aerosp Med Hum Perform. 2021; 92(7):570578.

The Effect of Forearm Shortening on Forearm Range of Motion

Osseous shortening of the forearm is performed during forearm replantation; however, no large clinical reviews have discussed its effects on patient outcomes. A recent cadaver study demonstrated the progressive loss of forearm pronation/supination ranges of motion with increased shortening lengths using external fixation. Our study aimed to quantify the effects of shortening on passive forearm motion using internal fixation after 2, 4, and 6 cm of mid-forearm shortening. A volar Henry approach and direct approach to the ulna were used on 8 cadaveric specimens. The forearms were sequentially shortened by 2, 4, and 6 cm. Fixation was performed on the volar surfaces of the radius and ulna. Pronation and supination of the forearms were tested by applying 1 Nm of torque at baseline and after the fixation of both the radius and ulna using osteotomy. Radiographs and measurements were obtained at each phase to determine the maximum radial bow and radioulnar gap. Data were analyzed using a linear mixed-effects model. Greater shortening of the radius and ulna led to progressively greater reductions in both pronation and supination range of motion. Larger differences were seen in supination at 2-4 cm of shortening and in pronation at 4-6 cm of shortening. Changes in supination were found to be associated with the radial bow and radioulnar gap; changes in pronation were found to be associated with the radial bow and radial bow's location. This study demonstrates that quantifiable effects on passive forearm motion occur after osseous shortening of the forearm. This information may improve surgeons' and patients' understanding of the changes in forearm motion expected after shortening in the setting of replantation or tumor resection or in the setting of limb salvage of a mangled extremity.

Parametric FEM modeling of multilayer castellated canted cosine theta (CCT) magnets

Canted cosine theta (CCT) magnets have received increased attention in the recent years due to their inherent characteristics of high field quality and low conductor stresses, as each turn is supported by the metallic former. CCT geometry is suitable for complex magnets—such as nested dipoles, which allow full 360° control of the magnetic field direction. Modeling and design of such magnets is the subject of this work. A parametric 3D modeling framework for multilayer CCT magnets has been developed and optimized allowing efficient model generation without a need for both: CAD software and time consuming meshing. The model has been created using the APDL scripting language and solved using the Ansys software. By direct generation of nodes and elements the time to generate a model with one million elements was of the order of 10 min. A framework for script generation was developed, as well as the relations between the mesh parameters and the total number of nodes and elements. Detailed mesh dependence study was carried-out with in-depth analysis of solver performance (solution time, amount of written data, RAM requirements). Global and local convergence criteria were introduced to find the optimal mesh size. The case of a four layer 2.5 Tm nested dipole was analyzed in details including the worst-case scenario with full debonding between the CCT layers. Thanks to the castellations the nested-dipole is safe to support 144 000 Nm of torque due to Lorentz forces even with full de-bonding between the layers.