Wire Displacement Research Articles

Analysis of the efficacy of Endobutton plate combined with high-strength suture Nice knot fixation in the treatment of distal clavicle fractures with coracoclavicular ligament injuries

ObjectiveTo investigate the efficacy of Endobutton plate combined with high-strength suture Nice knot fixation in the treatment of distal clavicular fractures with coracoclavicular ligament injuries.MethodsA retrospective analysis was performed on 43 patients who sustained distal clavicular fractures along with injuries to the coracoclavicular ligament. These patients were treated between January 2017 and December 2023. The fractures were classified according to the fixation method: high-strength Nice knot suture fixation (experimental group, n = 23) and acromioclavicular Kirschner wire fixation (control group, n = 20). The basic information of the two groups of patients, including age, gender, cause of injury, fracture classification, hospitalization duration, fracture healing time and complications, was collected and analyzed. The increase rate of coracoclavicular space on the affected side was collected and analyzed. The pain level of the affected shoulder was assessed using the visual analog scale (VAS). The shoulder joint function was assessed using the American Shoulder and Elbow Surgeons (ASES) scores and Constant-Murley scores before and after surgery.ResultsNo significant differences were observed in the general demographic data, including age, gender, injury etiology, Craig classification, and hospitalization duration between the two groups (p > 0.05). Both groups were followed for a period ranging from 12 to 33 months, with an average follow-up of 20.53 ± 5.16 months. The bone healing time in the experimental group was significantly shorter than in the control group (12.82 ± 1.12 weeks vs. 17.25 ± 1.71 weeks, p < 0.05). At the final follow-up, The increase rate of coracoclavicular space was (9.25 ± 2.53) % in the experimental group and (8.10 ± 2.53) % in the control group, which was not significantly different (p > 0.05). Both groups demonstrated significant improvements in VAS scores, Constant-Murley scores, and ASES scores post-operatively compared to pre-operative values (p < 0.05). One month after surgery, the Constant-Murley and ASES scores were significantly superior in the experimental group compared to the control group (p < 0.05). However, no statistical difference was observed three months post-surgery or during the final follow-up (p > 0.05). The control group reported one case of infection related to the Kirschner wire and one case of Kirschner wire displacement postoperatively. Conversely, no significant complications were reported in the experimental group.ConclusionIn the management of distal clavicle fractures accompanied by coracoclavicular ligament injuries, particularly oblique fractures or those with butterfly-shaped fragments, the application of a high-strength Nice knot suture in conjunction with Endobutton plate fixation can effectively stabilize the fracture site. This approach not only mitigates complications associated with Kirschner wire fixation but also enhances fracture healing, leading to favorable postoperative outcomes.

Performance and behaviour of prebored and precast pile with floating pile tip based on A full-scale field static axial load test

This study investigates the load transfer mechanism of a Prebored and Precast pile (PP pile), constructed installed in accordance with the rules applicable to the Hyper-Straight pile method (HS pile), in clay soils. While the HS pile method, developed in Japan, typically results in high bearing capacity piles in various soil types, its performance in clay soils remains understudied. Our research focuses on a unique configuration where the pile tip “floats” within a soil–cement mixing (SCM) column near the bottom of the borehole, a condition that significantly influences the system’s performance.We conducted a full-scale axial static load test on a 500 mm diameter and 140 mm thickness straight shaft precast prestressed concrete spun pile. The pile was instrumented with vibrating wire strain gauges (VWSG) and displacement measuring devices (tell-tales), embedded 15 m deep in a 750 mm diameter SCM column (15.75 m long). The pile tip was positioned 75 cm above the bottom of the borehole, creating a floating condition within the SCM material. Both the pile and the surrounding SCM were instrumented to provide comprehensive data on the system’s behavior.The test involved two loading–unloading cycles. The 1st Cycle reached a maximum load of 3627 kN, resulting in a 75.52 mm pile head settlement. The 2nd Cycle achieved a maximum load of 4181 kN, leading to a 118.04 mm pile head settlement. In the 1st Cycle, we observed upward movement of the SCM material around the shaft after the pile skin friction reached its maximum capacity. Stress at the pile tip exceeded the unconfined compressive strength of the SCM material, indicating potential local shear failure.Contrary to expectations based on HS pile performance in other soil types, the ultimate bearing capacity of our pile was determined to be 2000 kN, comprising 545 kN from skin friction and 1455 kN from end bearing. This result aligns more closely with the behavior of conventional bored pile rather than the “hyper” capacity typically associated with HS pile. Consequently, we classify our pile as a “prebored and precast pile,” like systems used in China and Korea.Our study concludes that the strength of the SCM material and the pile tip location significantly influence the pile’s bearing capacity in clay soils. These findings highlight the critical impact of soil type on the performance of piles constructed using the HS method. The observed behavior suggests that current design methods for HS pile may overestimate capacity in clay conditions, emphasizing the importance of soil-specific analysis and testing.This research contributes to the understanding of PP pile behavior in clay soils, providing valuable insights for geotechnical engineers. It underscores the need for refined prediction models and design methods specific to these soil conditions, paving the way for more accurate and reliable foundation designs in regions with predominant clay soils.

The driving characteristics of bidirectional SMA wire actuators - Theoretical modeling and experimental testing

Bidirectional shape memory alloy (SMA) wire actuators play a critical role in driving applications thanks to their characteristics in memory shaping and good overall performance. SMA wire actuators were often studied at a single load type, and there is no comprehensive comparison investigation of different SMA wire actuators in the literature. In this paper, the driving characteristics of four available types of SMA wire actuators, namely, dead-load, biased spring, differential type, and biased superelastic SMA wire actuators are modelled mathematically and then tested in laboratory settings. The characteristics of SMA wire actuators are quantitatively measured and then compared under a range of application scenarios. The output displacement and thermal-electric models of NiTi SMA wires are derived based on the Brinson constitutive model with stress effects in consideration. A customized SMA wire actuator test device is developed to evaluate the theocratical models and benchmark testing four types of SMA wires and their driving characteristics, including structure, design, displacement, response and recovery time, energy efficiency and hysteresis properties. The SMA wire phase transformation characteristics of the four actuators are tested under different activation currents, and then quantitatively compared. In conclusion, this paper adds theoretical and experimental significance to the literature on SMA wire actuators. The reference value on the phase transformation characteristics of SMA wires can be used to guide SMA application in industrial designs and enable theoretical studies in complementary research areas.

Analysis of guide wire displacement in robot-assisted spinal pedicle screw implantation

Robot-assisted pedicle screw placement is prone to guide wire migration, and the related influencing factors have not yet been discussed. Therefore, this study aimed to investigate and analyze the causes of robot-assisted spinal pedicle guide wire displacement and summarize the relevant treatment strategies. The surgical outcomes of 82 patients who underwent robotic-assisted pedicle screw spinal placement at our hospital between July 2022 and June 2023 were retrospectively analyzed. A total of 342 screws were placed in 82 patients; 47 guide wires were offset, 47 guide wires were replaced, and 295 guide wires were not significantly offset, with a first guide wire offset rate of 13.7% and a total guide wire offset rate of 12.1%. Univariate analysis showed that Screw placement level, whether respiration was controlled during guide wire placement, Hu value of CT, the position of needle insertion point, and operation time had a significant effect on guide wire deviation (P < 0.05). Multivariate logistic regression analysis showed that the inclusion of screw placement segments, whether breathing was controlled during guide wire placement, and Hu value of CT had a significant effect on guide wire offset (P < 0.05). Whether the guide wire was offset had no significant effect on the accuracy of subsequent pedicle screw implantation (P > 0.05). The level of screw placement, whether breathing was controlled during guide wire placement, and Hu value of CT were independent risk factors for guide wire deviation. When causing an excursion, screw orientation can be adjusted during intraoperative screw placement, and guide wire excursion has no significant impact on the accuracy of subsequent pedicle screw placement.

A ubiquitous, nearby reservoir of electromagnetic energy hidden in the fourth spatial dimension as a consequence of Kelvin’s rule (for constant electric currents) and of the Poynting vector

When applying what is called Kelvin’s principle to the elementary currents of two permanent magnets that attract each other, an apparent energy paradox appears. For Kelvin’s principle says that when constant electric currents are displaced with respect to one another, the mechanical work yielded as a result of the action of magnetic forces is equal in amount to the increase (not decrease) in the energy of the total magnetic field. The energy provided by the power supply in order to keep the currents constant is thus twice as large as the mechanical work yielded during the displacement of the current-carrying wires. But when dealing with permanent magnets and their polarization currents, there is still the yield of mechanical work and also the increase in energy of the total magnetic field, but no such thing as a visible power supply. In this article, things are analyzed by using the Poynting vector as an instrument. As a result, the topological assumption of a hidden reservoir of energy sitting in the direction of a fourth spatial dimension turns out to be indispensable in order to save the principle of local conservation of energy and of action by contact. A recognition of this kind was foreshadowed by Mie 100 years ago, who postulated that, in certain, but nevertheless common situations, energy flowed into ambient space out of the particles themselves both in the gravitational and the electromagnetic case.

Poster 129: Biomechanical Evaluation of the Isometry of Medial Patellofemoral Ligament Reconstruction Grafts Fixed at Non-Anatomic Femoral Insertion Points

Objectives: In MPFL reconstruction surgery, achieving perfect placement of the femoral tunnel intraoperatively is difficult. An understanding of the effects femoral tunnel malpositioning has on graft isometry is crucial to minimizing instability or overconstraint which leads to anterior knee pain, increased patellofemoral contact pressures, or graft failure. The purpose of this study was to identify differences in MPFL reconstruction graft isometry with femoral tunnel malpositioning, specifically evaluating isometry differences as the femoral position is moved anterior, posterior, proximal, and distal relative to the femoral radiographic landmark of the MPFL, Schottle’s point. Methods: A biomechanical study evaluating 11 fresh frozen cadaveric knees was conducted. Non-elastic suture, used as an MPFL graft analogue, was anchored at Schottle’s point with the knee at 30° of flexion, and at 5 mm and 10 mm anterior, posterior, superior, and distal to Schottle’s point. A draw wire displacement sensor was used to evaluate length changes of the MPFL graft analogue through 0-120° of knee flexion. Knee flexion position was continuously measured using a motion tracking system. Pairwise t-tests with Bonferroni corrections were used to compare isometry between Schottle’s point and non- anatomic femoral insertion points. Results: Grafts placed at Schottle’s point demonstrated mild anisometry with tightening in extension and loosening in flexion. Similarly, grafts placed distally and posteriorly also demonstrated tightening in extension and loosening in flexion. Grafts placed anteriorly and proximally demonstrated tightening in flexion. Mean and range of total draw wire excursion over full ROM across specimens is shown in Figure 1. The mean draw wire length was found to be greater with further displacement from Schottle’s point in all directions but posterior. Pairwise comparisons relative to Schottle’s point found grafts placed in the proximal or distal direction demonstrated significant differences in MPFL excursion, while grafts placed in the anterior or posterior direction did not (10 mm proximal: 0.36 (p=0.028), 5 mm distal: 0.14 (p=0.012), 10 mm distal: 0.22 (p&lt;0.001)) (Table 1). Conclusions: In order to minimize the risk of graft tightening during knee flexion, if deviating from Schottle’s point, it is safest to err posterior or distal in femoral tunnel position. Travel away from Schottle’s point in the proximal or distal direction has the greatest effects on graft isometry. The greatest risk of overconstraint and graft tightening in flexion is seen with proximal placement of the femoral insertion point.

Displacement Measurement of Urban Ramp Bridge Model Using Monocular High-Speed Camera

Urban ramp bridge plays an important role in unblocking urban traffic and improving urban road network structure. Aiming at the limitations of traditional contact sensors in global measurement, this paper adopts non-contact, high frame rate, high-precision monocular high-speed video measurement technology to measure the dynamic response of the ramp bridge model loaded on the shaking table. The feasibility of video measurement in structure measurement is verified by comparing with the results of wire displacement meter, and the overall measurement accuracy is better than 0.1mm. The seismic effects of two different isolation bearings are compared and analyzed, and the test shows that the plate rubber bearing has a better damping effect.

Effect of a liquid bridge on the dynamic behavior of diamond wires during slicing

Diamond wire sawing with narrower kerf losses and thinner as-cut wafers is a critical technology to further reduce wafering costs in the semiconductor industry. Nevertheless, as the scale of the wire web decreases, the effect of the liquid bridge formed by the capillary condensation of the cutting fluid between the diamond wires becomes significant. Moreover, the transverse wire vibration reduces the wire web gap at certain moments, which makes it easier for the wires to adhere to each other after wetting, thus hindering the slicing process. Therefore, a dynamical model for a double-wire system with liquid bridge action was developed in this study based on the transverse vibration theory of a diamond wire under support excitations to reveal the action mechanism of the liquid bridge between diamond wires. The dynamic adhesion process between the diamond wires moving with the supports is discussed. The effects of the guide wheel manufacturing error and the sawing parameters on the critical gap for spontaneous adhesion between the diamond wires are analyzed. The results show that the static double-wire system does not generate spontaneous adhesion when the surface gap of the wires is between the critical gap for spontaneous adhesion and the maximum adhesion gap. The support excitation causes the transverse wire displacement, which increases the critical gap for spontaneous adhesion to increase the risk of wires adhesion. The critical gap for spontaneous adhesion increases with increases in the guide wheel manufacturing error and the wire span as well as the wire speed and decreases with increases in the wire groove diameter and the wire tension. When the manufacturing error is doubled, the critical gap for spontaneous adhesion will increase more than twice this error increment. Strict control of the guide wheel manufacturing error is the most effective way of reducing the risk of wires adhesion during processing. Increases in the guide wheel diameter and decreases in the wire span and the wire speed within a reasonable range, or enhancing the mechanical properties of the wire to improve its breaking force, also help to reduce the critical gap for spontaneous adhesion.

Assessment of pantograph-catenary interaction in a railway overlap section via a novel optical-based method

• Pantograph-catenary interactions at an existing overlap span are investigated. • A novel optical-based method is proposed and implemented at the overlap span. • Single- and double-pantograph train passages are obtained and studied. • Dynamic effects rendering high contact forces, contact loss and arcing are studied. • Peak contact force, transition distance and train speed show a strong correlation. Smooth pantograph-catenary contact is essential for regular train operation. However, catenary section overlaps are locations where peak contact forces occur, which significantly affects current collection quality. This work studies pantograph-catenary interaction and transition at an existing overlap span by using a novel optical-based measuring method. Image sequences of eleven single- and two double-pantograph train passages were processed to obtain wire displacement responses. The unsynchronised vibration of two contact wires was found, and the first contact wire exhibits different modal responses. The spatial motion paths of contact wires were obtained to estimate the pantograph-catenary interaction. Dynamic effects rendering high contact forces, contact loss and arcing were investigated. The results show that pantographs with a long transition distance and a high intersection gradient cause a serve impulse with the second contact wire, resulting in contact loss and arcing. Finally, this study successfully estimated the transition distance and found it has a strong positive correlation with peak contact forces and train speeds. The transition distance exhibits an increasing tendency with increasing train speed. The longer transition distance results in a higher peak contact force.

Transverse forced vibration of a diamond wire under support excitations

Diamond wire sawing is a key technology for wafer processing in the semiconductor industry. Transverse wire vibration decreases the wire web gap to below the critical adhesion spacing between the wires, which is an important factor that limits the development of diamond wire slicing technology toward narrower kerf losses and thinner as-cut wafers. In fact, the external excitation source that causes the diamond wire vibration comes primarily from the supports at both ends of the wire. Therefore, an analytic model for transverse forced vibration of a diamond wire under support excitations was developed in this study based on the transverse vibration theory of an axially-moving string fixed at both ends. This partial differential equation with non-homogeneous boundary conditions was solved using the superposition principle and the finite element method. To verify the theoretical model, experimental equipment to text the transverse vibration of a diamond wire with support excitations was developed. The support excitation signal and the wire vibration response were obtained using accelerometer measurements and machine vision detection, respectively. The theoretical results agree well with the experimental results, indicating the correctness of this proposed model. The effects of the vibration source and the installation parameters on the transverse vibration displacement of a diamond wire are discussed. The results show that hysteresis in the movement of the center of the wire causes a certain additional high-frequency vibration, which can make this maximum transverse displacement to be greater than the excitation amplitude, thus making the wire transverse vibration change non-linearly with some parameters. The maximum transverse vibration displacement at the center of the diamond wire increases with increases in the guide wheel machining error amplitude and the wire diameter as well as the wire span, while it decreases with increases in the wire groove diameter and the wire tension. This maximum transverse vibration displacement decreases by approximately 100.22 % and 6.17 % when the guide wheel manufacturing error amplitude and the wire groove diameter are reduced by half and doubled, respectively. Improving the manufacturing accuracy of the guide wheel is still the most effective way of reducing the transverse vibration displacement of the wire. In addition, appropriate increases in the groove diameter and the wire tension and decreases in the wire span are also beneficial for suppressing the wire vibration.

Exploiting Net Connectivity in Legalization and Detailed Placement Scenarios

Standard-cell placement is the fundamental step in a typical VLSI/ASIC design flow. Its result, paired with the outcome of the routing procedure can be the decisive factor in rendering a design manufacturable. Global placement generates an optimized instance of the design targeting a set of metrics, while ignoring rules pertaining its feasibility. Legalization and detailed placement rectify this situation, attempting to attain minimum quality loss by often disregarding the connectivity between cells and making runtime the focal point of these steps. In this article, we present a set of variations on a connectivity-based legalization scheme that can either be applied as a legalizer or a detailed placer. The variations can be applied in the entirety of the chip area or in the confinement of a user-specified bin while they are guided by various optimization goals, e.g., total wire length, displacement and density. We analytically describe our variations and evaluate them through extensive simulations on commonly used benchmarks.

Effectiveness analysis of Endobutton plate combined with high-strength suture Nice knot fixation in the treatment of distal clavicle fractures

To investigate the effectiveness of Endobutton plate coracoclavicular fixation combined with fracture site high-strength suture Nice knot cerclage fixation in the treatment of distal clavicle fracture with coracoclavicular ligament injury. The clinical data of 33 cases of distal clavicular fracture with coracoclavicular ligament injury treated by Endobutton coracoclavicular plate fixation between January 2017 and December 2020 were analyzed retrospectively. According to the fixation methods of fracture site, they were divided into two groups: the high-strength suture Nice knot fixation group (study group, 16 cases) and the transacromial Kirschner wire fixation group (control group, 17 cases). There was no significant difference between the two groups in common data such as age, gender, injury side, cause of injury, Craig type, combined injury, time from injury to operation, and preoperative visual analogue scale (VAS) score and Constant-Murley score ( P>0.05). Postoperative fracture healing and complications were observed, and the increase rate of coracoclavicular space on the affected side was calculated at last follow-up. VAS score was used to evaluate shoulder pain before operation, at 1 week, 1 month, 3 months after operation, and at last follow-up. The shoulder function was evaluated according to Constant-Murley shoulder score before operation, at 1 month, 3 months after operation, and at last follow-up. The operations were successfully completed in both groups without severe complications such as vascular nerve injury and coracoid fracture. In the control group, 1 case (5.9%) had slight pin tract infection and 1 case (5.9%) had Kirschner wire displacement; there was no obvious complication in the study group. The patients in both groups were followed up 9-36 months (mean, 22.9 months). The fracture healing time of the study group and the control group were (12.56±0.73) weeks and (13.59±0.87) weeks, respectively, and the difference was significant ( t=-3.661, P=0.001). At last follow-up, the increase rates of coracoclavicular space on the affected side of the study group and the control group were 8.88%±1.19% and 8.55%±1.07%, respectively, showing no significant difference ( t=0.837, P=0.409). The postoperative VAS score and Constant-Murley score of the two groups significantly improved when compared with those before operation, and the two scores gradually improved with the extension of time after operation ( P<0.05). Except that the VAS score at 1 week and 1 month after operation and the Constant-Murley score at 1 month after operation in the study group were significantly better than those in the control group ( P<0.05), there was no significant difference between the two groups at other time points after operation ( P>0.05). For oblique fracture or combined with butterfly fracture in the distal clavicle fracture with coracoclavicular ligament injury, the fracture site high-strength suture Nice knot fixation is a good supplement to the Endobutton plate coracoclavicular fixation. It can stabilize the fracture end, reduce the complications of Kirschner wire fixation, and is more conducive to fracture healing. The effectiveness is satisfactory.

Simulation of Wire EDM Combined with Measurements of Discharge Locations and Wire Displacement

This paper describes a development of a wire electrical discharge machining simulation combined with the measurements of the wire displacement and discharge locations. The wire displacement was measured using an optical sensor to obtain the discharge reaction force and damping coefficient of the wire vibration which are variable during machining. The discharge locations were measured to obtain the points where the discharge reaction force is applied. Considering the discharge reaction force and electrostatic force acting on the wire electrode, the wire deflection and vibration were calculated to obtain the machined workpiece geometry to be compared with the experimental results. Most significant advantage of the simulation newly developed is that those parameters can be updated in real time during machining. With the help of the sensor fusion, the parameters were found to change with increasing the depth of cut and the cut geometries could be simulated with higher accuracy.

Penetrating Injury of the Lingual Nerve Following Orthodontic Wire Displacement

A 39 year old female attended hospital with a 5 day history of trismus, anaesthesia of the left side of the tongue and pain associated with the lower left mandibular region. Having undertaken a thorough assessment, it became evident that the lower orthodontic stainless steel wire, had become displaced posteriorly, penetrating the retromolar soft tissue space and lingual nerve. Removal of the wire provided improvement in the patients’ symptoms and resolution of the trismus.

The cross-sectional effects of ribbon arch wires on Class II malocclusion intermaxillary traction: a three-dimensional finite element analysis

BackgroundThe application of intermaxillary traction is often accompanied by the unexpected movement of dentition, especially anchorage teeth. The aim of this study was to comprehensively compare the influence of cross-sectional shape of ribbon arch wires with edgewise and round wires on intermaxillary traction in Class II malocclusion treatment using FEA simulation.MethodsThe dentofacial structure was simulated in finite element software. A retraction force of 1.5 N was applied to different cross-sectional orthodontic arch wires: a ribbon wire (0.025 × 0.017-in. and 0.025 × 0.019-in.), a rectangular wire (0.017 × 0.025-in. and 0.019 × 0.025-in.) and a round wire (Φ 0.018-in. and Φ 0.020-in.).ResultsAmong the three groups, ribbon wire (0.025 × 0.017-in. and 0.025 × 0.019-in.) exhibited the lowest displacement in the X-axis (12.61 μm and 12.77 μm, respectively) and Z-axis (8.99 μm and 9.06 μm, respectively). However, the 0.025 × 0.017-in. ribbon wire showed the highest Y-axis displacement. In the round wire group, Φ 0.020-in. wire displayed less rotation than Φ 0.018-in. wire, where the sagittal, frontal and occlusal rotation of Φ 0.020-in. wire was almost half of that of Φ 0.018-in. wire. The movement of the first molar region was intermediate between the ribbon arch group and the round wire group. Notably, the values of the 0.025 × 0.017-in. arch wire displacement, which were higher than those of any other group, peaked at 0.019 mm in the central incisor region with a spike-like shape. The deformation range of the Φ 0.018-in. wire group was the largest in this study.ConclusionsThe cross-section of the arch wire influenced force delivery in Class II intermaxillary traction. With the same shape, a larger cross-sectional area led to less mandibular dentition movement. For the rectangular arch wire and ribbon arch wire groups, since the height and width were inverted, the vertical displacement of anchorage teeth in the ribbon wire group was reduced, but the possibility of buccal tipping in mandibular anterior teeth also increased.

A new torsion tester based on an electronic autocollimator for characterizing the torsional behaviors of microfibers.

Torsional properties of single fibers have considerable effects on the performance of fabrics. A new torsion tester with high resolution is developed based on the torsion-balance method and the autocollimation principle for measuring the torsional properties of single fibers. The tester can measure the torque accurately using the torsion wire of known torsional rigidity. The angular displacement of the torsion wire is measured by a non-contact electronic autocollimator. The calibration results show that the maximum torque capability is around 6 × 10-6 N m with a theoretical resolution of about 8 × 10-11 N m. The instrument's validity is verified by comparing the measurement result with that obtained by a torsion pendulum. Torsion tests on four industrially microfibers, including glass fiber, polyimide fiber, carbon fiber, and gold wire, are performed with the tester, which gives shear moduli 71.0 ± 0.4, 5.6 ± 0.1, 22.6 ± 3.1, and 34.3 ± 0.5GPa, respectively. Young's moduli of these fibers are also provided. It is demonstrated that these fibers have a high anisotropy in mechanical properties.

Contact point lateral speed effects on contact strip wear in pantograph – catenary interaction for railway operations under 15 kV 16.67 Hz AC systems

The design of a railway catenary is subject to multiple decisions regarding the geometry of the system. In particular, the horizontal geometry of the contact wire determines the evolution of the wear of the contact wire and contact strip over time. The horizontal geometry is obtained through the stagger, a lateral displacement of the contact wire at the supports. The value of the stagger, length of the span, curvature of the track, and train speed within the span determine the speed at which the contact point between the wire and the pantograph moves over the contact strip from side to side. A wider stagger corresponds to a larger area of the wear distribution over the contact strip. However, the speed at which the contact point moves over the strip is also important to the wear due to the sliding contact. Thus, the catenary design affects the contact strip wear through the lateral speed of the contact point. In this paper, a study of the lateral speed effects on contact strip wear is presented. The findings include a model of the lateral speed effect on the wear and a recommendation for a lower limit value for the lateral speed of 330 mm/s.

Implementation of Implantation-Stagger Measuring Unit using Image Processing

The electrical traction system of railways is a combination of physical upright structures and OCL(Overhead Contact Lines). The horizontal distance from the center of the track to the OHE mast called implantation, horizontal displacement of overhead contact wire with respect to the center of the railway track called stagger, and the perpendicular height of overhead contact wire from the ground are periodically checked by a lineman in order to ensure a safe distance from the railway track. In this paper, we have put forth an idea of building a distance measuring device to measure the implantation and stagger without touching the objects using Open CV on raspberry pi with a camera module which will be placed at the center of the track. The system will be having two features. To measure the distance of the nearest poles, the camera has to be placed facing the mast perpendicular to a circle of diameter appropriate which is placed on the pole for measurement purposes. And to measure the stagger, the camera has to be placed facing the overhead wire from the center of the track.

Measurement of temperature and displacement with NiTi actuators under certain electrical conditions

In this study, various mechanical behaviors of a shape memory alloy, depending on different thermal and electrical conditions to be used in areas such as biomedical, aerospace and aeronautics. Temperature changes and length change rates under different electrical current values of a shape memory alloy named “nickel titanium”, or “nitinol” (NiTi) has been observed. It has been seen that a 0.3 mm diameter wire can generate a force of 25 N while the material extends its linear measurement with a rate of 3.7 mm/s. It is observed that, under diverse constant electrical current values, the displacement and temperature relations of the nickel titanium wire is varying. It has empirically been seen that the nickel titanium alloy actuators are advantageous than their alternatives in terms of the generated strength to weight ratio and shape memory alloy materials can be used as actuators in industrial and biomedical applications.

Identification of a localization wire tip in an occult breast lesion using a handheld magnetometer.

The Sentimag hand-held probe detects the magnetic response from iron oxide particles trapped in a sentinel node. To investigate if an electromagnetic probe can be helpful in the identification of a hook wire tip located in an occult breast lesion. Forty-two patients undergoing lumpectomy without axillary procedure were enrolled. In all cases, suspicious non-palpable microcalcifications without mass were found, and a vacuum-assisted stereotactic biopsy was performed. On the day of surgery, a traditional localization wire (LW) was placed under imaging guidance. The Sentimag magnetometer was used to precisely detect the wire tip through the skin. Then, the skin incision was made and Sentimag was used again to guide the surgeon to the lumpectomy bed. The accuracy of excision was assessed with intra-operative specimen 3D tomosynthesis. Median lesion size was 16 mm (range: 4-38 mm) and median depth was 33 mm (range: 14-78 mm). In all cases, the wire tip was successfully identified. Neither wire displacement nor transection occurred. Intraoperative radiography demonstrated doubtful margin requiring selective cavity shaving in 6 patients (14%). The need for cavity shaving was significantly influenced by the lesion size and histology: median size 30 mm (range: 24-38 mm) compared to 15 mm (range: 4-28 mm) and histology of ductal carcinoma in situ (DCIS) compared to atypical ductal hyperplasia (ADH) and lobular neoplasia (LN). Tumors requiring cavity shaving tended to be deeper - they had a median depth of 43 mm (range: 17-78 mm) compared to 32 mm (range: 14-76 mm) in patients who did not need cavity shaving, but this parameter was statistically significant. Intraoperative identification of the wire tip using Sentimag is a simple technique facilitating targeted excision without excessive removal of breast tissue. Since it is not associated with additional costs, it may be worth considering, particularly in developing countries.