Coaxial Wires Research Articles

Initial arch wires used in orthodontic treatment with fixed appliances.

Initial arch wires used in orthodontic treatment with fixed appliances.

Comparison of Shear Bond Strength, Adhesive Remnant and Precision Fit between Conventional Lingual Retainers and Customised CAD/CAM Fabricated Lingual Retainers: An In-vitro Study

Introduction: Fixed lingual bonded retainers offer the comfort of aesthetics and reduced tissue irritation after orthodontic treatment but are wrought with frequent bond failures. Numerous techniques have been used to adapt the retainer to the lingual surface of the lower anterior teeth, but research on customised lower lingual retainers is scarce. Aim: To evaluate and compare the Shear Bond Strength (SBS), Adhesive Remnant Index scores (ARI), and precision fit of a novel Computer-aided Designing-Computer-aided Machining/ Manufacturing (CAD-CAM) fabricated retainer and conventional retainers. Materials and Methods: This invitro study was conducted at the Department of Orthodontics, and Dentofacial Orthopaedics, SRM Dental College, Ramapuram, Chennai-89 from June 2022 to February 2023. It included a total of 360 human mandibular anterior teeth were collected and embedded in acrylic blocks in groups of six to simulate the mandibular anterior arch form. A total of 60 retainers made of braided Stainless Steel (SS) wires, co-axial wires, customised through CAD/CAM technology were evaluated. The retainers were bonded to the lingual aspect of the teeth using composite resin. A universal testing machine was used for testing SBS. Precision fit was observed using Exocad software. Statistical analysis included one-way Analysis of Variance (ANOVA) for SBS, Kruskal-Wallis for ARI score, and Mann-Whitney U test for precision fit. Results: The CAD-CAM retainers had a more precise fit when compared to conventional retainers (p=0.009). SBS was highest for CAD-CAM fabricated retainer and lowest in the co-axial retainer, and this finding was statistically significant (p<0.001). The CAD-CAM retainer had the highest mean rank in ARI scores (33.90) when compared to braided SS and co-axial wire. Conclusion: The CAD-CAM fabricated retainers would be more effective clinically, as higher bond strength due to precise fit would reduce the failure rate, thus preventing relapse and minimising chairside time.

Structural Batteries – the Best or Worst of Two Worlds

The electrification of road transport is continuously progressing, and concomitantly lithium-ion batteries are developing towards higher energy densities. However, the theoretical limitations of this technology are expected to be reached in the coming years [1], leaving more demanding applications, like aeronautic ones, with high challenges regarding fully battery electric propulsion of commercial aircrafts. Structural batteries (or multifunctional energy storage), i.e. batteries which show sufficient mechanical stability to substitute conventional composite materials in load bearing structures, show a promising way to resolve this issue. Due to their multifunctional properties, structural batteries can replace interior and exterior elements of e.g. an airplane, and thus provide at best energy storage without weight increase [2].The idea of structural batteries emerged around 20 years ago, and different cell designs have been proposed including coaxial wires [3] and planar reinforced stacks [4]. Nevertheless, high degrees of multifunctionality could not be realized and the approach was never industrially applied [5]. Recently, the need to electrify the mobility sector and the prospect of massless energy storage has reincited a lot of new research activities around this topic.The main challenge at electrochemistry level for the development of structural batteries is to find an alternative electrolyte for the conventionally used carbonate-based liquid ones which provide only negligible mechanical stability. Apart from high ionic conductivities and safety, the additional requirements for the structural electrolyte include high mechanical capabilities (e.g. high Young’s modulus), good adhesion to all cell components, as well as high thermal stability. The latter is especially important for implementation of the structural batteries in composite structures, which are usually cured at elevated temperatures well beyond the stability range of conventional electrolytes. These demanding specifications render the use of conventional lithium-ion battery components formassless energy storage as futile.In this work, two different approaches for the development of electrolytes for structural batteries are discussed. The first one employs a bi-continuous electrolyte based on thermoset materials, whereas the second one uses a gel electrolyte. For the former two separate phases form percolating networks with different properties throughout the electrolyte membrane. One phase provides high ionic conductivity to achieve high electrochemical performance of the cells, whereas the other one yields high mechanical strength. The second approach uses a mono-phasic electrolyte which provides both, electrochemical as well as mechanical performance. The two approaches are further compared and discussed, focusing on their applicability for structural batteries. Important parameters like processability and feasibility for implementation into a composite structure, which are often neglected, are addressed, enabling a holistic view on this technology.

EFFECTS OF FLUORIDE PROPHYLACTIC AGENTS ON THE MECHANICAL PROPERTIES OF ORTHODONTIC ARCH WIRES- AN INVITRO STUDY

Background And Objectives: There are the rising demand for esthetic orthodontic appliances and wires such as braided and co-axial wires. The effect of prophylactic agents on these relatively newly introduced arch wires are scarcely reported. Hence this study was undertaken to assess the effects of prophylactic uoride agents (1.Acidulated uoride agent (Phos-ur gel), 2. Neutral uoride agent (Prevident 5000)on the mechanical properties of non-coated Nickel-Titanium orthodontic wires and compare it with coated esthetic Ni-Ti wires and braided Ni-Ti wire. Materials And Methods: Total of 270 specimens of rectangular orthodontic nickel titanium arch wires were selected for this study and divided into three groups. All the three groups of wires (30 each) were immersed in 5 ml of articial saliva in plastic vials for 2 months (control). No uoride agents were used in sub-group a. Sub-group b and sub-group c samples were subjected to application of Phos-ur gel and Prevident 5000 respectively, one minute daily for 2 months. All the wires were tested for mechanical properties. Results: The results of the study showed that the mechanical properties of all the three groups of wires were affected by both acidulated uoride agent (Phos-ur gel) and neutral uoride agent (Prevident 5000). Conclusion: The study results proved that uoride prophylactic agents (mouthwash or gels) reduce the arch wire properties during orthodontic treatment.

A Wirebonding Instrument for Insulated and Coaxial Wires

A tool has been developed that supports a novel microelectronic integration paradigm whereby interconnects between components are directly established by means of microcoax wire bonding. A near-term use case of the tool is to facilitate rapid prototyping of high-bandwidth systems. When further matured, it will be able to rapidly integrate complex systems with hundreds or thousands of interconnects with minimal design time. Automatic stripping and bonding of coax wires having overall diameters between 50 and 100 μm present an array of process challenges that pose interesting demands on the material system of the wire and the bonding tool. This study reviewed a microcoax bonding system that is currently in development at Draper which is able to strip, feed, and bond microcoax wire. The system utilizes a combination of electric flame-off and thermal reflow to strip outer metal shielding and polymer dielectric layers, respectively. It leverages a rotary wire feed mechanism to precisely control wire position so that predetermined wire lengths can be established. Progress in the design of the wires, tooling, and software control architecture is reviewed.

Alignment of buccally placed canine with modified transpalatal arch

Alignment of malposed teeth is generally treated using coaxial wires, NiTi wires, or HANT wires. However, when canines which are ectopically erupted are tried to be aligned with NiTi wires, due to their bulky root structure, there is a risk of round tripping of adjacent teeth. This unnecessary round tipping creates load on the anchorage (leading to anchor loss) and prolongs the treatment duration. In this case, a unique approach to align buccally placed canine using a modified transpalatal arch (TPA) has been discussed. This case report describes a 20-year-old female, with a buccally placed left maxillary canine, being placed totally out of the arch. The first premolar was extracted to make space for the canine in the arch. The canine was brought into alignment using a palatal traction with the help of a modified TPA and an E-chain initially and later a closed coil spring attached to a palatal button on the canine.

Optical spectrum of monolayer and coaxial quantum wires: Impact of spin-orbit interaction

Simultaneous effects of spin-orbit interaction, external electric and magnetic fields and quantum confinement on the optical absorption coefficient and refractive index of a mono-layer and coaxial quantum wires are investigated in this paper. Finite element method and numerical calculations are established to find energy eigenvalues, energy eigenfunctions and transition dipole moments to obtain desired optical parameters. Results show that spin-orbit interaction exhibits different effects at various field strengths and dimensions. Due to the anti-crossing of energy states and tunneling effect new results are observed in comparison with usual nanostructures.

A Wirebonding Instrument for Insulated and Coaxial Wires

Abstract A tool has been developed that supports a novel microelectronic integration paradigm whereby interconnects between components are directly established by way of micro-coax wirebonds. A near term use-case of the tool is to facilitate rapid prototyping of high-bandwidth systems. When further matured, it will lead to the ability to rapidly integrate complex systems with hundreds or thousands of interconnects with minimal design time. Automatic stripping and bonding of coax wires having overall diameters between 50 to 150μm presents an array of process challenges that pose interesting demands on the material system of the wire and the bonding tool. This paper will review a micro-coax bonding system that is currently in development at Draper which is able to strip, feed and bond micro coax wire. The system utilizes a combination of electric-flame-off (EFO) and thermal reflow to strip outer metal shielding and polymer dielectric layers respectively. It leverages a rotary wire feed mechanism to precisely control wire position so that pre-determined wire-lengths can be established. Progress in design of the wires, tooling and software control architecture are reviewed.

Combinations of tunneling and spin-orbit interaction effects on the thermodynamics and entropy of coaxial quantum wires

Thermodynamical properties of a typical coaxial quantum wire under the simultaneous effects of external electric and magnetic fields with great attention to the spin-orbit interaction and tunneling effects are investigated. To this aim the Schrodinger equation is solved to find the energy eigenvalues and eigenfunctions of the system and the Tsallis formalism is used to find thermodynamical parameters such as entropy, internal energy, and specific heat. Results show the considerable effect of the spin-orbit interaction and external fields on the electronic and thermodynamics of the presented complex system. It is shown that the tunneling phenomenon has considerable and interesting effects on the energies and entropy in comparison with mono-layer quantum wires without tunneling effects.

Arch Expansion Efficiency of Coaxial Tubular Superelastic Nickel-Titanium in Comparison to Single-Stranded Superelastic Nickel-Titanium While Relieving Mandibular Anterior Crowding: A Randomized Controlled Study.

Aim:The aim of the study is to compare the efficiency of six-stranded coaxial tubular superelastic nickel–titanium (NiTi) archwire and a single-stranded wire in relieving anterior mandibular crowding.Materials and Methods:This double-blind randomized study included 40 patients, categorized into two groups: Sentalloy round group and Speed tubular supercable group (20 each). After taking alginate impressions, the allocated archwire was engaged. With a digital caliper, intercanine, interpremolar, and intermolar width were recorded on the study models, immediately and at 4, 8, and 12 weeks stages. The Statistical Package for the Social Sciences (SPSS) version 20 was used for analysis.Results:The measured parameters were increased in both the groups, with the difference being insignificant statistically.Conclusion:Superelastic coaxial NiTi wires show better efficiency in relieving anterior crowding than single-stranded NiTi wire.

Making Coaxial Wires Out of Janus Dendrimers for Efficient Charge Transport.

Highly conductive coaxial supramolecular wires are prepared by using a new family of Janus dendrimers that combines two rigid aromatic parts and two flexible aliphatic parts. The two external regions consist of a promesogenic block based on a third generation Percec-type dendron with four terminal dodecyloxy alkyl chains, whereas the two internal regions are formed by one, two, or three carbazole units bearing flexible spacers. These functional Janus dendrimers self-organize in columnar liquid crystal phases with a strong coaxial segregation within each column. Interestingly, the charge mobility studies revealed that these Janus dendrimers display semiconductor properties with hole mobility values up to 0.5 cm2 V-1 s-1, depending on the packing within the columns which can be tuned by the number of carbazole functional units. The high hole mobility values measured in these materials are among the highest values reported for columnar liquid crystals.

Initial arch wires used in orthodontic treatment with fixed appliances.

Initial arch wires used in orthodontic treatment with fixed appliances.

Coaxial wires coax energy from water

Inexpensive, earth-abundant photoabsorbers for solar water splitting have, so far, not demonstrated notable performance. Now, voltage gained from a coaxial heterojunction coupled with nanostructure-enhanced photocurrent results in Cu2O photocathodes demonstrating benchmark water-splitting performance.

P 100 A 64-channel dry multipin-electrode cap for EEG

Multichannel Electroencephalography (EEG) is widely used in clinical neurology and neuroscientific research. EEG caps with 64 wet Silver/Silver-Chloride (Ag/AgCl) electrodes represent an often-used standard in the field. Reproducible electrode-skin contact for these electrodes is ensured by electrolyte gel or paste. Thus, these electrodes require specific mechanisms to apply and hold the gel at the electrode positions in the caps and require skilled personnel to apply the EEG cap. Dry electrodes allow more degrees of freedom in the design and fabrication of EEG caps and can be self-applied without preparation. We present a novel 64-channel EEG cap with dry electrodes. The base material of the EEG cap is a light-weight and flexible fabric, which contains small holes (perforation) making it breathable. Polyurethane (PU) based multipin electrodes serve as dry contact electrodes. A coating provides electrical conductivity of these polymer based electrodes. The use of silver coating opens the way for dry AgCl electrodes and thus, signal quality similar to wet Ag/AgCl electrodes. Thin coaxial wires are soldered to the bottom of the electrodes enabling active shielding. A second layer of fabrics protects the electrodes and the wires. Our results demonstrate that resting state EEG, eye movements, alpha activity, and pattern reversal VEP can be recorded with the novel dry 64-channel EEG cap with short preparation time and without significant differences between the novel EEG cap and a conventional cap based on wet Ag/AgCl electrodes. In conclusion, the proposed novel 64-channel EEG cap with dry electrodes can potentially replace conventional wet 64-channel EEG caps and thus enable new fields of application like brain-computer-interfaces and mobile EEG acquisition.

A Comparative Evaluation of Effect of Reinforced Autopolymerizing Resin on the Flexural Strength of Repaired Heat-polymerized Denture Base Resin before and after Thermocycling.

Aims and Objective:Denture fractures are a common problem in clinical practice. Despite the use of different reinforcement materials (metal wires, metal plates, and various types of fibers) for denture repairs, recurrent fractures are still common. The purpose of this study was to compare the maximum flexural loads of the heat-polymerized denture base resin when repaired with autopolymerizing resin reinforced with relatively smaller diameter metal wires and glass fibers, before and after thermocycling.Materials and Methods:Heat polymerized rectangular specimens were fabricated and repaired with autopolymerized resin and different reinforcement materials. Stainless steel wires, coaxial wires, beta-titanium wires, and glass fibers were used as reinforcement materials. Metal wires were sandblasted before placing in the center of the specimen along with autopolymerizing resin. Control specimens were repaired without any reinforcements. Intact heat- and self-cure specimens were also prepared for comparison. Half of the specimens of each group were subjected to thermocycle stressing (5°C and 55°C, 30 s dwell time) for 2000 cycles. All the specimens, nonthermocycled as well as thermocycled, were then tested for flexural strength by using 3 point flexural test in Lloyd's Universal testing machine at 5 mm/min crosshead speed. The maximum flexural loads (N) for each specimen were recorded. The readings, thus obtained, were subjected to statistical analysis using two-way ANOVA and Tukey's multiple comparison test.Results:The metal wire reinforcements increased the flexural strength of repaired specimens, whereas, glass fiber reinforcement produced slightly lower flexural strength when compared to those of control specimens, i.e., repair without any reinforcement. The highest flexural strength was demonstrated by specimens repaired with coaxial wire reinforcements (50.01 and 43.77 N before and after thermocycling, respectively). The increase in flexural strength with the use of stainless steel wire (45.12 and 41.56 N) and beta-titanium wire reinforcements (45.54 and 42.61N) was insignificant.Conclusions:Coaxial wire reinforcement produced significantly higher flexural loads than control. Increase in strength with stainless steel wire and beta-titanium wire was insignificant, whereas glass fiber reinforcement reduced the strength.

Forces in initial archwires during leveling and aligning: An in-vitro study.

Aim:This in-vitro study measured the force deflection behavior of selected initial alignment archwires by conducting three-point bending tests under controlled tests. The study tested three wire designs, namely, co-axial multistranded stainless steel wires, nickel–titanium, and copper–nickel–titanium archwires.Materials and Methods:The archwires were ligated to a specially designed metal jig, simulating the arch. A testing machine (Instron) recorded activation and deactivation forces of different deflections at 37°C. Forces on activation and deactivation were compared by one-way analysis of variance (ANOVA).Results:Significant differences (P < 0.05) in activation and deactivation forces were observed among the tested wires. The co-axial multistranded wire had the lowest mean activation and deactivation forces, whereas conventional nickel–titanium wires had more mean activation and deactivation forces at different deflections.Conclusion:The activation and deactivation forces were higher for nickel–titanium followed by copper–nickel titanium and co-axial wires. The amount of percentage force loss was more for co-axial wire, indicating that these wires are not ideal for initial leveling and aligning.

An original device for train bogie energy harvesting: a real application scenario

Today, as railways increase their capacity and speeds, it is more important than ever to be completely aware of the state of vehicles fleet‟s condition to ensure the highest quality and safety standards, as well as being able to maintain the costs as low as possible. Operation of a modern, dynamic and efficient railway demands a real time, accurate and reliable evaluation of the infrastructure assets, including signal networks and diagnostic systems able to acquire functional parameters. In the conventional system, measurement data are reliably collected using coaxial wires for communication between sensors and the repository. As sensors grow in size, the cost of the monitoring system can grow. Recently, auto-powered wireless sensor has been considered as an alternative tool for economical and accurate realization of structural health monitoring system, being provided by the following essential features: on-board micro-processor, sensing capability, wireless communication, auto-powered battery, and low cost. In this work, an original harvester device is designed to supply wireless sensor system battery using train bogie energy. Piezoelectric materials have in here considered due to their established ability to directly convert applied strain energy into usable electric energy and their relatively simple modelling into an integrated system. The mechanical and electrical properties of the system are studied according to the project specifications. The numerical formulation is implemented with in-house code using commercial software tool and then experimentally validated through a proof of concept setup using an excitation signal by a real application scenario.

A comparative evaluation of mandibular incisor decrowding with coaxial and optiflex arch wires and their load-deflection rates.

Aim:The aim of this study is to determine and compare the load-deflection rate of optiflex arch wire with that of coaxial arch wire and to determine and compare the decrowding efficiency of optiflex arch wire with coaxial arch wire within a period of 45 days.Materials and Methods:Load-deflection rates of optiflex and coaxial wires were found using the INSTRON (4300) machine. A steady load was given to the wire to make it deflect, and the load required to deflect the wire for every 1 mm up to 5 mm, were noted and tabulated. A total of 10 patients, 10-25 years of age (seven males and three females) were selected. All patients had angles Class I malocclusion with a crowding discrepancy of 3-9 mm (according to little's index). All patients required first premolar extraction. Pre (0 day) and post (45th day) treatment study models and lateral cephalograms were taken for all patients and evaluated.Results:Optiflex had a low load-deflection when compared to coaxial wire. Clinically, optiflex and coaxial wire had similar decrowding efficiency. In both, study model and cephalometric analysis, there was no statistically significant value when comparing their mean variables.Conclusion:Optiflex is an appropriate wire for patients seeking esthetics during fixed appliance therapy as it combines esthetics and efficiency by delivering light continuous forces.

Comparison of three different orthodontic wires for bonded lingual retainer fabrication

ObjectiveWe evaluated the detachment force, amount of deformation, fracture mode, and pull-out force of 3 different wires used for bonded lingual retainer fabrication.MethodsWe tested 0.0215-inch five-stranded wire (PentaOne, Masel; group I), 0.016 × 0.022-inch dead-soft eight-braided wire (Bond-A-Braid, Reliance; group II), and 0.0195-inch dead-soft coaxial wire (Respond, Ormco; group III). To test detachment force, deformation, and fracture mode, we embedded 94 lower incisor teeth in acrylic blocks in pairs. Retainer wires were bonded to the teeth and vertically directed force was applied to the wire. To test pull-out force, wires were embedded in composite that was placed in a hole at the center of an acrylic block. Tensile force was applied along the long axis of the wire.ResultsDetachment force and mode of fracture were not different between groups. Deformation was significantly higher in groups II and III than in group I (p < 0.001). Mean pull-out force was significantly higher for group I compared to groups II and III (p < 0.001).ConclusionsDetachment force and fracture mode were similar for all wires, but greater deformations were seen in dead-soft wires. Wire pull-out force was significantly higher for five-stranded coaxial wire than for the other wires tested. Five-stranded coaxial wires are suggested for use in bonded lingual retainers.

Time-delayed decentralized H2/LQG controller for cable-stayed bridge under seismic loading

SUMMARY Consistency of real-time data transmission is an important factor in active and semi-active control of structures. Recent advances in wireless sensors and their reliable data communication have attracted many attentions in structural control engineering. Wireless sensors have been also preferred to wire-base types because of problems associated with installing extensive length of coaxial wires. In addition, embedded computing technologies in wireless sensors as local controller reduce size of transferring data and provide stable transmission. However, there are some issues in implementation of wireless connection like communication range and latency. This study presents the feasibility of developing a decentralized controller by using H2/LQG as robust-optimum algorithm in cable-stayed bridge. Because of large scale of structure, the order of model is reduced by using two different reduction methods in finite time and frequency. The controller is developed in centralized and decentralized solutions. The decentralized controller through developing a gradient-based method is designed to efficiently solve system of closed-loop H2 optimization problem. The structural responses in centralized and decentralized solutions are compared with each other under three different earthquake records considering time delay in data transmission. Results indicate that for large-scale bridges with time-delayed data communication issue, H2/LQG controller in decentralized solution gives maximum reduction of response indices in comparison with other strategies. Copyright © 2011 John Wiley & Sons, Ltd.