Wire Twisting Research Articles

Biomechanical analysis of tension band wiring (TBW) of transverse fractures of patella

PurposeTension band wiring is commonly used for fixation of simple transverse fractures. The popular configuration is parallel Kirschner wires (K-wires) and a stainless steel wire loop placed in a vertically oriented figure-of-8. MethodsWe used a wooden model of a patella with a midway transverse fracture and compared four different types of fixation. The first construct had a vertical figure-of-8 with one twist of wire. The second contained a vertical figure-of-8 with two twists of wire. The third was a vertical figure-of-8 with two twists of wire placed at adjacent corners while the last one had a horizontal figure-of-8 with two twists of wire placed at adjacent corners. Interfragmentary compression at the point of wire breakage was measured for each construct as well as permanent displacement on cyclic loading. ResultsPlacement of the figure-of-eight in a horizontal orientation with two wire twists at the corner improved interfragmentary compression by 63% (p < 0.05, Tukey post hoc test). On cyclic loading, all the constructs with vertical figure-of-eight but none with a horizontal construct failed (p = 0.01; Fisher's exact test). Permanent fracture displacement after cyclic loading was 67% lower with horizontal figure-of-eight constructs (p < 0.05; t test). ConclusionPlacing wire twists at the corner and a horizontal placement of figure-of-8 improves stability of the construct.

The use of the teleparallelism connection in continuum mechanics

The geometry of parallelizable manifolds – that is, teleparallelism − is summarized in the language of local frame fields. Some problems in continuum mechanics that relate to the couple stresses that are produced in the bending and twisting of prismatic beams and wires are then discussed. It is then shown that by going to a higher dimensional analogue of the geometry that one uses for one-dimensional deformable objects, one is basically using the methods of teleparallelism in the context of the Cosserat approach to deformable bodies.

A wire deflection detection method based on image processing in wire + arc additive manufacturing

In wire and arc additive manufacture (WAAM), the twist of wire during a robot’s movement can result in the sudden changes of the wire-feeding position and thus cause deposition defects and dimensional errors. In the worst case, it may cause wire jamming and damage of the wire-feeding system. Therefore, online monitoring and correction of the wire deflection are very important for WAAM. In this paper, a vision-based measuring method is proposed for detecting the deviations of the wire-feeding position of a plasma welding-based WAAM process. It uses adaptive threshold and Hough transform to extract the wire edges, judges and merges the coincident lines, and applies Radon transform to measure the wire deflection. Software to automatically detect the wire deviation was developed based on the proposed method. The method and the software were verified with experiments.

Tension control of wire rope in winch spooler using magneto rheological brake

While operating conventional spooler system in heavy industries such as winch reel and cranes, wire rope tangling and twisting leads wire aging with short life cycle and entangling occurs catastrophic damage to the whole system. The aim of this work is investigating a tension control system using a magneto rheological brake (MRB) to provide back tension to prevent frequent part changes and fatal malfunction. In order to achieve this aim, a basic MRB is first designed and analyzed using finite element method (FEM) with electromagnetic field and fluid analysis are performed. As second step, a prototype of the an MRB is fabricated with the optimized structural parameters and experimental apparatus is constructed. Moreover, output torque characteristics of the designed MRB with the various input current and rotational speed are evaluated. Consequently, a conventional proportional-integral-derivative (PID) controller is designed for a tension control, and the control results show the feasibility for tension control of winch spooler system.

Quench Protection using CLIQ of a MgB&lt;sub&gt;2&lt;/sub&gt; 0.5 T Persistent Mode Magnet

A protection system using the coupling loss induced quench (CLIQ) method has been simulated for an eight coil 0.5 T MRI main magnet designed with MgB 2 superconducting wire. The temperature rise was modeled in MATLAB using the Douglas-Gunn method to solve the three-dimensional heat equation and Heun's method was used to solve the circuit equations associated with the CLIQ electrical circuit. The wire's twist pitch and the voltage and capacitance of the CLIQ unit can be varied to study their impact on quench protection performance. Simulations of CLIQ protection were performed on the entire 0.5 T eight coil magnet. The peak temperature varied with the wire's twist pitch. The optimal twist pitch was around 3.5 and 5.5 cm assuming the lowest and highest transverse resistivity, respectively. For the entire main magnet using CLIQ protection, the peak temperature reaches 188 K with a 10 mF capacitor at 1.3 kV.

Determination of a Real Strain-stress State of the Steel-wire Rope Elements

Today steel-wire ropes are used as a pre-stressed reinforcement for the large-span reinforced concrete structures that are considered as solid isotropic bars. Meanwhile, it's not taken into account that the rope represents a composite structure with the axial spiral anisotropy of properties, where a combined strain-stress state (SSS) occurs. On the basis of Kirchhoff differential equations for thin curved bars, the author develops a generic mathematical model of the steel twisted rope with a linear contact of wires. This model enables one to determine a combined strain-stress state of the rope elements taking into consideration its geometrical characteristics (wire size, twist angle of a twisted rope) and mechanical characteristics of steel (elasticity and shear moduli). The paper presents calculation of irregularity of stress distribution between a core and wires of the steel rope К-7 (1+6) in case of different rates of wire twisting. Knowing the real strain-stress state in the steel rope elements, one can specify an effective pre-stressing of the rope.

Tight Placement of Erich Arch Bar While Avoiding Wire Fatigue Failure

To determine the number of wire twists needed to acquire ideal Erich arch bar tightness before wire fatigue failure (fracture) in relation to different distances and angles at which different gauge wires are grasped to provide information to improve the efficiency of arch bar application. This study mimicked surgical placement of arch bars with 24- and 26-gauge wires. The number of twists to tightness and failure was evaluated when the wire distance between the arch bar and wire holder tip changed (5 vs 10 mm) and when the degree at which the wire was held relative to the tooth axis was changed (45° vs 90°). A wire shearing test also was used to investigate the fatigability of wires tightened under these same conditions. Wires twisted to tightness, past tightness, and after shearing test movements were visualized with electron microscopy. For 24-gauge wire held at 5 mm, 2.6 to 2.8 twists were needed for wire tightness, with failure after 1.7 to 1.9 twists past tightness; for 24-gauge wire held at 10 mm, 4.4 to 4.9 twists produced tightness, with failure after 2.3 to 2.9 twists past tightness. For 26-gauge wire held at 5 mm, 3.3 to 3.5 twists provided tightness, with 1.6 to 1.8 twists past tightness causing failure; for 26-gauge wire held at 10 mm, 5.1 to 5.5 twists produced tightness, with 3.1 to 3.7 twists past tightness causing failure. At a 45° angle, the wire tightened with fewer twists and showed more resistance to failure with twists past tightness compared with 90° using 24- and 26-gauge wires. In contrast, 24-gauge wire held at a 5-mm distance showed the opposite result, with decreased resistance to failure at the 45° angle. However, the differences were not statistically meaningful. Scanning election microscopy showed no wire fatigue for either angle for 26-gauge wire held at a 5-mm distance and twisted to tightness. After overtightening and oscillation, the 90° angle trials showed fatigue, whereas the 45° angle trials did not. Holding a 24-gauge wire at 45° to the tooth axis is recommended owing to fewer twists to tightness and more resistance to failure. A 5-mm grasping distance is recommended for experienced surgeons owing to fewer twists to tightness, whereas a 10-mm grasping distance is recommended for novice surgeons owing to a greater tolerance for over-twisting before failure.

Quench Detection Method for HTS Coils Using Electromagnetically Coupled Coils

Generally, in order to detect the quench of the superconducting field coil for the superconducting rotating machine, signal wires for voltage taps are indispensably needed. However, the problem of the conventional method is wire twisting as the superconducting field coil rotates. Therefore, in this paper, authors suggest a new method to detect the quench of the superconducting field coil using electromagnetically coupled coils. The suggested method consists of two superconducting pancake and copper solenoid coils. Two superconducting pancake coils play roles of a field coil and external (alternating) field generation for the rotating machine. In addition, two copper solenoid coils are used to transmit the voltage wirelessly and receive the transmitted voltage using electromagnetic induction. In order to verify the feasibility of this method, experiments are performed according to the transporting current flowing through two superconducting pancake coils and separation distance between two copper solenoid coils. The result shows that it is expected to apply this method to the superconducting rotating machines for the detection of quench without direct connection of voltage taps.

Calculation of Torsional Stiffness of Conductor and its Influence on the Stability of Motion

In galloping, reverse split wire plays an important role in. Through the study of split change sub conductor length of wire twisting motion estimation, the wire tension change caused by the torsion of sub conductors; besides considering some of the split wire torsion stiffness of the external factors, but also the influence of torsion wire tension change, caused by the conductor sag, line height worse, we deduced the general formula to calculate the new conductor spacer system torsional stiffness.

A Wireless Control System for 3D Microscope

This paper proposes a wireless control system for a 3D Microscope which is designed to move in two directions - polar and azimuth angle. Both angles are controlled with electric motors based on the users joystick command and the pechan prism motor is controlled to compensate image rotation whiling moving in polar angle. Since 3D microscope can be used for arbitrary rotation in azimuth angle, wireless control system is proposed to avoid twisting of power and signal wires. The validity of our system is shown through experimental works.

Tight Placement of Erich Arch Bar While Avoiding Wire Fatigue Failure

The Erich arch bar is an important surgical device to secure occlusion for jawbone fracture treatment including open and closed reduction, prior to temporomandibular joint and maxillofacial reconstructive surgery, and occasionally skeletofacial deformity correction. The main concern for placement of the Erich arch bar is time consumption during surgery due to a trial and error approach to wire tightening. The objective of this research was to determine the number of wire twists needed to acquire ideal Erich arch bar tightness before wire fracture (fatigue failure) in relationship to the different distance and angle at which the surgeon grasps the wire with the wire holder. Using this multi-variable clinical experiment, these data were used to present oral and maxillofacial surgeons with a primary clinical guide to aid in the application of Erich arch bars.

Three-dimensional deformation comparison of self-ligating brackets

Archwire rotation is used in orthodontic treatment to alter the labiolingual orientation of a tooth. Measurement of the 3-dimensional (3D) motion of the orthodontic brackets requires a new configuration of the orthodontic torque simulator. The orthodontic torque simulator was coupled with a stereo microscope and 2 cameras to allow for the 3D bracket motion to be determined during wire twisting. The stereo camera images were processed with a 3D digital image correlation technique to determine the 3D deformation of the orthodontic brackets. Three self-ligating brackets (Damon Q, Ormco, Orange, Calif; In-Ovation R, GAC, Bohemia, NY; and Speed, Strite Industries, Cambridge, Ontario, Canada) were compared by using the 3D digital image correlation method to demonstrate the difference in 3D motion of self-ligating brackets components. Contour plots of the 3 brackets demonstrate the 3D motion of the bracket tie-wings and the archwire retentive component. The 3D motion of the bracket tie-wings and archwire retentive component were quantified. The displacement values of the archwire retentive component measured with the 3D orthodontic torque simulator were found to be 2.0 and 3.5 times less for the In-Ovation and Damon Q brackets than the values in previous studies that examined the compliance of the archwire retentive component. The 3D digital image correlation method used to quantify bracket deformation showed the 3D motion of the bracket tie-wings and the motion of the archwire retentive component. The use of a 3D optical measurement system is useful to understand the motion of the archwire retentive component but is not necessary to quantify bracket tie-wing motion. This measurement technique can be used to evaluate brackets of varying designs.

The Lyme Disease Debate Host Biodiversity and Human Disease Risk

In the mid-1970s, several children in the town of Lyme, Connecticut, began to suffer from painful, swollen joints. They were diagnosed with juvenile rheumatoid arthritis, a rare condition. Clinicians at Yale School of Medicine suspected the cluster of cases was caused by an infectious agent.1 The illness, dubbed Lyme disease, was soon recorded in an increasing number of patients in the northeastern United States. Symptoms included rashes, fevers, joint and muscle pain, and heart and neurological problems. National Institutes of Health researcher Willy Burgdorfer identified the culprit in 1982: a spirochete bacterium that, in electron micrograph images, resembles a broken twist of barbed wire.2 The spirochete, named Borrelia burgdorferi (Bb), was first isolated from the gut of ticks collected in woodlands on Shelter Island, New York, where Lyme disease had become endemic. The deer tick (Ixodes scapularis) transmits the bacterium Borrelia burgdorfi (Bb) to humans in the course of one of three blood meals it will take in its lifetime. Thirty years after its discovery, Lyme disease has become by far the most common vectorborne infection in North America.3 Today the ecology of Bb is the subject of both intense study and intense scientific debate. Some researchers think that protecting large tracts of forest habitat—a strategy that increases the diversity of vertebrate hosts for both Bb and its tick vectors—will ultimately reduce the risk of human infection. Others argue that there is no predictable relationship between host biodiversity and human disease risk.

Synthesis of intermetallic NiAl compound nanoparticles by pulsed wire discharge of twisted Ni and Al wires

Pulsed wire discharge using twisted Ni and Al wires has been tried to synthesize intermetallic NiAl compound nanoparticles. The effects of wire twisting and gas atmosphere conditions on the constituent phases of the synthesized particles were investigated. Ni and Al wires corresponding to the molar composition ratio of 1:1 were hand-twisted to form twined wires with various twisting number per 25 mm which is the nominal span length between the electrodes. Pulsed large current was applied to the twisted wires set between the electrodes in N2 or Ar atmosphere. The results were discussed based on the deposited energy in the wires which can be evaluated from the voltage and current at the wires. Nanoparticles consisting of almost single-phase NiAl compound were synthesized at limited conditions of the N2 atmosphere and the twisting number range of 5–15 turn per 25 mm. At these conditions, the deposited energy in the wires was higher than the vaporization energy of the wires. At the other experimental conditions, other phases such as Ni2Al3 compound phase and metallic Al phase were detected as well as the NiAl phase. Major experimental results in this study can be explained based on the deposited energy in the wires.

Hemodynamic support during high-risk PCI: a single-center comparison of in-hospital events between intraaortic balloon pump, Tandem Heart and Impella device

with any other technique of stenting. Guidewire twisting was the most frequent technical problem (24% of SzT). No major complications occurred during the procedure. Conclusion: The Szabo technique is highly successful in stenting ostial and bifurcated stenosis when performed by skilled operators. The incidences of failure are mainly related to wire twisting. Use of 6-Fr GC or higher is strongly recommended.

The catheterization laboratory and interventional vascular suite of the future: Anticipating innovations in design and function

The catheterization laboratory and interventional vascular suite of the future: Anticipating innovations in design and function

Measurement of Orthodontic Bracket Tie Wing Elastic and Plastic Deformation by Arch Wire Torque Expression Utilizing an Optical Image Correlation Technique

Orthodontic lingual root movement (torque) is an important aspect of treatment biomechanics and is typically achieved by torsion of a rectangular wire within the orthodontic bracket slot which introduces a force couple. The magnitude of the force moment achieved by wire torsion may be influenced by deformation of the orthodontic bracket. A device utilizing an optical image correlation technique has been developed to accurately quantify bracket slot dimensional changes during application of wire torsion. Simultaneous torque moment magnitude, degrees of wire twist, and bracket slot dimension data can be gathered. Bracket tie wing elastic deformation when loaded was demonstrated and plastic deformation was also observed with a single rotation of the wire.

Electromechanical Behavior of IBAD/MOCVD YBCO Coated Conductors Subjected to Torsion and Tension Loading

Combined twist and tensile loading states are expected in many applications of YBCO coated conductors. Wire twist is introduced due to winding on complex shapes or for AC loss reduction, while tensile loading originates from sources such as differential thermal expansion and inertial forces. In this study, we analyse the electromechanical behavior of an IBAD/MOCVD YBCO coated conductor configuration with the superconducting layer deposited on hastelloy substrate and encapsulated by copper. The effect of pre-applied twist on degradation of current carrying capability as a function of tensile stress was studied via experimental measurements on tapes with 1 micron thick YBCO layer and 50 micron thick hastelloy substrate at 77 K. In addition, the stress states under pure torsion are modeled using continuum mechanics. Both numerical and approximate analytical solutions are presented, and the stress and strain distributions as a function of applied twist angle are analysed.

Clinical Feasibility and Usefulness of CT Fluoroscopy-Guided Percutaneous Transhepatic Biliary Drainage in Emergency Patients with Acute Obstructive Cholangitis

ObjectiveTo evaluate the feasibility of CT fluoroscopy (CTF)-guided percutaneous transhepatic biliary drainage (PTBD) in emergency patients with acute obstructive cholangitis.Materials and MethodsThe study included 28 patients admitted to the emergency center due to obstructive jaundice and found to require urgent biliary drainage, as well as judged to have a suitable peripheral bile duct for a CTF-guided puncture (at least 4 mm in width). Prior to the CTF-guided puncture, a CT scan was performed to evaluate bile duct dilatation and the underlying causes of biliary obstruction. If the patient was judged to be a suitable candidate, a CTF-guided PTBD was performed in the same CT unit without additional fluoroscopic guidance. Technical feasibility of the procedure was investigated with the evaluation of overall success rate and causes of failure.ResultsA hepatic puncture was attempted at the left lobe in 23 patients and right lobe in five patients. The procedure was successful in 24 of 28 patients (86%) Successful biliary puncture was achieved on the first attempt in 16 patients, the second attempt in five patients, and the third attempt in three patients. The causes of failure included guide wire twisting in one patient, biliary puncture failure in two patients, and poor visualization of the guide wire in one patient. There were no significant procedure-related complication.ConclusionThe CTF-guided PTBD is technically feasible and highly successful in patients judged to have a suitable indication. Moreover, although the procedure is unfamiliar and inconvenient to interventionalists, it has economical advantages in that it saves time and manpower. We believe this method can be used in the emergency patients requiring urgent biliary drainage as an alternative for the fluoroscopy-guided PTBD.

Analysis of twisting of search coil leads as a method reducing the influence of stray fields on accuracy of magnetic measurements

The twisting of a pair of leads connecting to a search coil used for detection of magnetic field or flux density reduces errors due to stray magnetic fields. Although this method is commonly used, the influence of stray fields is often underestimated. This could lead to degradation of the accuracy of measurements. This paper presents an analysis of the influence of the quality of wire twisting and its possible influence on the signal-to-noise ratio. Twisted wires are approximated as a two-dimensional configuration, for which typical results of calculations are presented. The paper also reports the results from measurements using manually and machine-twisted pairs of wires. The analysis shows that the stray field influence can be reduced by up to 60% by proper twisting of a pair of wires connecting a sensor to measuring equipment.