Wire Configuration Research Articles

Study of spatial correlations in a crumpled wire trapped in two-dimensional cavities of different topologies

In this paper, it is reported a study of spatial correlations in configurations of a plastic wire trapped in two-dimensional planar cavities of different topologies defined by particular distributions of fixed pins that introduce excluded domains. The configurations examined were obtained from an extensive experimental study that shows that the jammed packing fraction of the wire within the cavities depends heavily on the topology of the cavity. The analysis reveals regions of the configurations dominated by finite-size effects controlled by the drive force of injection, and bulk domains strongly controlled by the density of pins. In the bulk regime a persistence length, as obtained in the Kratky–Porod model of polymers, is found to depend linearly with the number of pins which develops the role of an inverse effective temperature. That is, the temperature for the system in this case depends on the topology of the space. The regions characterized by finite-size effects present two regimes corresponding to different mechanical rigidities.

Influence of wire configuration on resistance to fragment distraction of tension bands placed in a greater trochanteric osteotomy model.

To determine the influence of wiring configurations on initial tension and resistance to tensile loads in tension band constructs without the contributions of Kirschner-wire stabilization. Experimental study. A solid brass femur model manufactured on the basis of computed tomography of a normal right femur of a 30-kg dog modified by transection of the greater trochanter and placement of two pins that did not cross the simulated osteotomy. Four tension band configurations were applied to the metal trochanteric osteotomy model: figure-of-eight with one twist (OT), figure-of-eight with two twists (TT), dual interlocking single loop, and double loop (DL). Configurations were tested under both monotonic loading (n = 8 per configuration) and incremental cyclic loading (n = 8 per configuration). Initial tension after tying, residual tension remaining after each cycle, and failure load at 2 mm of displacement (considered equivalent to clinical failure) were compared between configurations. The initial tension and the load to 2 mm of displacement were lower for OT wires compared with TT wires. The DL was the strongest and most stable configuration, generating 2.3 to 3.5 times greater initial tension, maintaining a greater percentage of residual tension under incremental cyclic loads, and resisting 2.0 to 2.4 times greater load before failure at 2 mm. Failure load was highly correlated with initial tension. Wire configurations reaching greater initial tension, such as the DL, allowed constructs to resist higher tensile loads. Wire configurations allowing higher initial tension may be warranted when tension bands are expected to sustain high tensile loads.

A further analysis of blocking action of the circuit breaker in the relay protection

With the development of the ages and social progress, our country has enormously developed in the field of smart power system. In most of the power systems, the hydraulic actuator, the operating mechanism and the spring energy storage operating mechanism are all the core issues in the current relay protection circuit breaker opening and closing. The effect of its operation will have a direct impact on the power system and circuit breaker performance. In this paper, by classifying the circuit breaker operating and analyzing the relationship between the blocking action and the relay protection, we can further analyze the blocking action of the circuit breaker in the relay protection, so that we can choose the better action position, and analyze and make researches by following the circuit wiring and dual configuration.

A Review of Fundamental Combustion Phenomena in Wire Fires

Electrical wires and cables have been identified as a potential source of fire in residential buildings, nuclear power plants, aircraft, and spacecraft. This work reviews the recent understandings of the fundamental combustion processes in wire fire over the last three decades. Based on experimental studies using ideal laboratory wires, physical-based theories are proposed to describe the unique wire fire phenomena. The review emphasizes the complex role of the metallic core in the ignition, flame spread, burning, and extinction of wire fire. Moreover, the influence of wire configurations and environmental conditions, such as pressure, oxygen level, and gravity, on wire-fire behaviors are discussed in detail. Finally, the challenges and problems in both the fundamental research, using laboratory wires and numerical simulations, and the applied research, using commercial cables and empirical function approaches, are thoroughly discussed to guide future wire fire research and the design of fire-safe wire and cables.

Singularity Expansion Method for thin wires and the Method of Modal Parameters

Abstract. Here, we describe a technique to define the Singularity Expansion Method (SEM) poles for short-circuited thin-wire structures developed using the Method of Modal Parameters (MoMP). The MoMP method consists of in the expansion of the system of mixed-potential integral equations (MPIE) into the Fourier series, including the kernels containing Green's function. Corresponding equations for Fourier modes contain infinite matrices of p.u.l. inductance and capacitance, and the solution for current can be obtained using the infinity matrix of p.u.l. impedance. The SEM poles are given by the zeros of the determinant of this matrix. For the case of the symmetrical circular loop, this equation transforms to one well-know from the literature. Numerical investigation of solutions for the poles of the first layer has shown good agreement with previously obtained analytical and numerical results for different wire configurations.

Multicentre collaborative cohort study of the use of Kirschner wires for the management of supracondylar fractures in children

PurposeSupracondylar fractures of the humerus cause significant morbidity in children. Nerve damage and loss of fracture reduction are common recognised complications in patients with this injury. Uncertainty surrounds the optimal Kirschner wire configuration and diameter for closed reduction and pinning of these fractures. This study describes current practice and examined the association between wire configuration or diameter and outcomes (clinical and radiological) in the operative management of paediatric supracondylar fractures. MethodsChildren presenting with Gartland II or III supracondylar fractures at five hospitals in south-west England were eligible for inclusion. Collaborators scrutinised paper and electronic case notes. Outcome measures were maintenance of reduction and iatrogenic nerve injury. ResultsAltogether 209 patients were eligible for inclusion: 15.7% had a documented neurological deficit at presentation; 3.9% who were neurologically intact at presentation sustained a new deficit caused by treatment and 13.4% experienced a clinically significant loss of reduction following fixation. Maintenance of reduction was significantly better in patients treated specifically with crossed ×3 Kirschner wire configuration compared to all other configurations. The incidence of iatrogenic nerve injury was not significantly different between groups treated with different wire configurations. ConclusionWe present a large multicentre cohort study showing that crossed ×3 Kirschner wires are associated with better maintenance of reduction than crossed ×2 or lateral entry wires. Greater numbers would be required to properly investigate nerve injury relating to operative management of supracondylar fractures. We found significant variations in practice and compliance with the British Orthopaedic Association Standard for Trauma (BOAST) 11 guidelines.

Sodium-ion concentration flow cell stacks for salinity gradient energy recovery: Power generation of series and parallel configurations

Salinity gradient (SG) energy is a renewable and clean energy resource that exists worldwide from the change in Gibbs free energy when two solutions with different salinities are mixed. More recently, concentration flow cells (CFCs) have been introduced as a new technology for SG energy recovery with the highest reported power density output to date as a result of the utilization of both the electrode potential and Donnan potential. In this study, multiple CFCs are connected to form a consecutive number of stacks, and systematic analysis is conducted to investigate the influence of both parallel and series electrical wire connections on the overall performance. For both wire connections, an effective increase in the overall power output with an increase in stack size is observed. The power densities normalized to the membrane area are however lower (3.7 W m−2 in series and 5.8 W m−2 in parallel, for 5-stacks) than that of the individual cell unit (8.9 W m−2) because the back of the stack experiences cumulative mixing. Additionally, as a result of an ionic cross-conduction causing a parasitic current in the series cell, the parallel wire configuration is demonstrated to be more successful in the CFC stack than the series.

Numerical estimation of AC losses in Bi2212/Ag wire and coil

The multi-filamentary Bi2Sr2CaCu2O8-x (Bi2212) round wire is the candidate for high field magnets, which is macroscopically isotropic and has large critical current in high field. AC losses generated in coils by ac transport current and magnetic field will lead to the rise of local temperature and consumption of liquid helium. However, the simulations of AC losses in coils are limited by the complicated geometry. This paper presents a homogenization model for computing the current density distributions, field distributions and AC losses in coils wound by multifilament Bi2212/Ag round wire. Based on two-dimensional axisymmetric H-formulation (H is the magnetic filed), the field dependent critical current density and the nonlinear relation between the electric filed E and the current density J are used to describe the macroscopic behavior of the superconductor. To validate the homogenization model, the AC loss is compared with the result of origin model which has the actual filament configuration of round wire. The homogenization model is powerful to estimate the AC losses of cables and coils made by Bi2212/Ag round wire.

The effect of thermal magnonic excitations on the electronic conductance of a magnetic nanowire

Abstract In this paper, we study the effect of thermal magnonic excitations on the electronic conductance of an anti-ferromagnetic nanowire which is coupled to two electrodes in the framework of equilibrium statistical mechanics. The electron-magnon scattering is assumed to be present only in the center part, not in the electrodes. For each magnonic mode of the chain, we calculate a Green’s function and the corresponding mode-dependent transmission coefficient via the linear response theory. Then, the total electronic transmission through the system is obtained by the summation of the mode-dependent ones. We examine the influence of magnonic waves on three different configurations for the center wire including uniform, alternative on-site (AB) and polyacetylene like (PA-like) chain. Two types of nonmagnetic and ferromagnetic structures are chosen for the left and right leads. The results show that the effect of magnonic excitations on the electronic conductance of the considered systems is important at high temperatures. Especially, the electron tunneling conductance is improved in the presence of magnonic excitations in the PA-like and AB nanowires in contrast to the uniform one. While for all configurations, the conductance decreases in the resonance region by increasing the magnonic effects. Finally, we discuss the spin polarization and we show that the effect of thermal magnonic excitations is more observable in AB with respect to PA-like and in PA-like with respect to the uniform configuration of the center wire.

Calibration of a numerical prediction methodology for fretting-fatigue crack initiation in overhead power lines

A methodology is developed for the prediction of fretting fatigue phenomenon that results in crack initiation in strands of overhead power line conductors. A numerical approach based on finite element analysis is used to obtain the local stress and strain fields for application of crack initiation criteria in the high cycle fatigue regime. Solutions for the stress field in the stabilised state, where further loading cycles no longer introduce changes to the plastic deformation, are obtained using the stationary incremental method. Cases where convergence does not occur due to significant ratcheting are disregarded as low cycle fatigue. Post-treatment analysis that includes localised averaging is used to implement a fatigue criteria that estimates the crack initiation risk. Validation of this approach is made by comparing with results obtained from experimental measurements made on a simplified clamp wire configuration. Analyses of a simplified three-dimensional configuration with fretting is presented for a range of loading parameters and qualitative trends are established, which will prove invaluable for lifespan assessment of overhead power lines.

Comparison of cross pinning versus lateral three pins in type three supracondylar fracture of distal humerus in children.

Background:
 Supracondylar fracture of distal humerus is the most common paediatric fracture. Type III supracondylar fractures should be treated with anatomical reduction and stable Kirschner wire (K- wire, pin) fixation to prevent the cosmetic deformity. The configuration of wires is debatable. Although two crossed K-wires are bio-mechanically stable, there is a risk of iatrogenic ulnar nerve injury. Lateral 3 K-wires is a good alternative. This study was done to compare the outcome of cross K- wire and lateral 3 K-wires in terms of stability.
 Materials and Methods:
 This is a prospective study done in Manipal Teaching Hospital. All the Gartland type 3 supracondylar fractures of the distal humerus were treated with closed reduction and stabilized with K wires. In Group I, fractures were stabilized with cross K wire fixation and in group II they were stabilized with 3 lateral K-wires. The patients were followed up at 4-5 weeks for wire removal and at 3 months and 6 months after surgery. Baumann's angle, a functional outcome as per Flynn's criteria, and range of motion were recorded in each visit. Outcomes were compared in term of displacement of fracture.
 Result:
 Seventeen children in each group were taken up for the study. There were no significant differences in term of patients and fracture character. No patients had significant loss of reduction at final follow up. There is no statistically significant difference seen in mean changes of Bauman's angle. According to Flynn's criteria good result was seen in more than 95% of cases in both groups.
 Conclusion:
 Both cross K-wires and Lateral 3 K-wires provide good stability. Fixation of supracondylar fracture from lateral side had an advantage of no risk of iatrogenic Ulnar nerve injury. Addition of third K-wire from lateral side provides good stability as that of cross K- wire fixation.

Use of synchrotron-based radiography to diagnose pulsed power driven wire explosion experiments.

We describe the first use of synchrotron radiation to probe pulsed power driven high energy density physics experiments. Multi-frame x-ray radiography with interframe spacing of 704 ns and temporal resolution of <100 ps was used to diagnose the electrical explosion of different wire configurations in water including single copper and tungsten wires, parallel copper wire pairs, and copper x-pinches. Such experiments are of great interest to a variety of areas including equation of state studies and high pressure materials research, but the optical diagnostics that are usually employed in these experiments are unable to probe the areas behind the shock wave generated in the water, as well as the internal structure of the exploding material. The x-ray radiography presented here, performed at beamline ID19 at European Synchrotron Radiation Facility (ESRF), was able to image both sides of the shock to a resolution of up to 8 μm, and phase contrast imaging allowed fine details of the wire structure during the current driven explosion and the shock waves to be clearly observed. These results demonstrate the feasibility of pulsed power operated in conjunction with synchrotron facilities, as well as an effective technique in the study of shock waves and wire explosion dynamics.

Effects of wire diameter, yarns size and wire configuration to wire cloth electrode produced from textile technology for dielectrophoresis application

Dielectrophoresis (DEP) is one of an alternative way for cell separation. It has mainly been limited to processing small volumes due to constrain in fabrication of microelectrode over large surface areas. This work focuses on optimizing the wire cloth electrode fabricated from the use of textile technology. The plain-weave wire cloth consists of stainless steel wires as the microelectrode arrays and polyester yarn as the insulator. The study involved producing wire cloth electrode with variations of wire diameters, yarn sizes and wire configuration (single or double twisted). Simulation using FEMLAB software was conducted to study the electric field generated from the wire cloth. The performance of the finished wire cloth electrode was then tested by conducting a small-scale separation experiment. It was found that larger diameter wire electrode and smaller yarn size resulted to higher electric field strength. In regards to wire configuration, double twisted wire led to higher electric field intensity and better nonuniformity with 1.25% and 9.29% higher cell separation yield recorded than single wire for 100μm and 71 μm, respectively.

Integrated all-optical wavelength and polarization conversion of orbital angular momentum carrying modes.

Wavelength division multiplexing (WDM) using higher-order spatial modes such as orbital angular momentum (OAM) through a channelized bandwidth provides enhanced capacity communication systems. An all-optical wavelength converter is a key function in implemented WDM networks to overcome the wavelength contentions. In addition, a polarization converter provides efficient control on the state of polarization for encoded data channels in the optical networks. This paper proposes a novel versatile-designed integrated optical device with Ycut ridge lithium niobate photonic wire configuration that acts as a wavelength or polarization converter for data modulated on OAM. It is schemed in such a way that generates decomposed guided modes with a new wavelength and polarization via cascaded second harmonic generation/difference frequency generation (cSHG/DFG) and type-II DFG nonlinear interactions, respectively, where their desired relative phase is achieved by a linear electro-optical effect in the successive phase shifter part. The low loss ≤0.09 dB/cm, high purity (≥94%), and low voltage (≤4 V) of the high-speed proposed modulator enable its compatible operation in commercial wireless and fiber-based polarization-multiplexed WDM communication systems.

Outcome Analysis of Lateral Pinning for Displaced Supracondylar Fractures in Children Using Three Kirschner Wires in Parallel and Divergent Configuration.

Background:Supracondylar humerus fracture is the most common fracture around elbow in children. Closed reduction and percutaneous Kirschner wire (pin) fixation is the standard method of managing displaced extension type (Gartland Type II and Type III) supracondylar humerus fractures. The configuration of wires is debatable. Although two crossed K-wires are mechanically stable, there is an inherent risk of ulnar nerve injury. Lateral K-wires – parallel or divergent – are good alternative. This study was aimed at identifying the best configuration for the lateral wires.Materials and Methods:Patients with Gartland type 3 supracondylar humerus fractures were randomized by envelope method to receive closed reduction and K-wire fixation in either a parallel or divergent fashion. The patients were followed up at 3 weeks for wire removal and at 6 weeks and 3 months after surgery. Baumann's angle, functional outcome as per Flynn's criteria, and range of motion were recorded in each visit. Effect of delay in surgery was also evaluated as a secondary outcome.Results:Nineteen patients received fixation with parallel wires and 11 patients had divergent fixation. No loss of reduction was seen in any patient at 3 months. No statistically significant difference was seen in the Baumann's angles and outcome according to Flynn's criteria irrespective of the wire configuration (divergent or parallel). Furthermore, the delay in surgery was also found not to have a significant effect on the functional outcome.Conclusions:Both parallel and divergent K-wire configurations provide satisfactory stability when accurate reduction and adequate fixation of the fracture has been done. Based on the limited number of patients in this study, one configuration cannot be judged to be superior to the other.

Paediatric humeral supracondylar fractures

The supracondylar humeral fracture is the most common elbow fracture in children accounting for just under one-fifth of all paediatric fractures and 60% of paediatric elbow fractures. Modifications of the Gartland classification have been made over the years. The mainstay treatment option is that of closed reduction and percutaneous wiring. However, there remains no gold standard in the management of this injury. Outcomes from other treatment options, including traction and external fixator application have been described and report good results. There remains controversy in the wiring configuration used, and there is no consensus on the approach to be used when faced with an irreducible fracture. This article aims to provide an up-to-date overview of the current practices in the management of this common injury, including the ‘pink pulseless’ hand, ‘poorly perfused white’ hand, surgical techniques, and the associated complications that can ensue.

Polymer elastic bump formation through photodefinable thermal reflow process for system in foil package

In this study, hemispherical polymer elastic bumps with 200 μm diameter were formed using a highly heat-resistant photodefinable polymer to realize a system in foil package. Because polymers have a more temperature-dependent modulus than a metal, a dynamic mechanical analysis (DMA) test was performed to analyze the modulus of the polymer. The results showed that the storage modulus of the cured photodefinable polymer used for producing the polymer elastic bumps was ~3.5 GPa at room temperature, and the glass transition temperature (Tg) was 210 °C–220 °C. A single polymer elastic bump package was modeled by using the modulus values obtained from the DMA test, and the deformation under loads was analyzed using the finite element method and compared with the results for conventional copper bumps. The results showed that the bump coplanarity can be corrected easily in hemispherical polymer elastic bumps because they show large z-axis deformation under loads. The test also showed that the stress on an ultrathin chip (thickness: 20 μm) is less than half that on copper bumps. In addition, the deformation behavior depending on the metal wiring configuration on the polymer elastic bumps was analyzed under different temperature and load conditions by using a microtribometer. The analysis of the contact resistance on a single polymer elastic bump verified that the polymer can be used as a material for bumps.

Generation of mutually unbiased bases for 4D-QKD with structured photons via LNOI photonic wire

A combination of orbital angular momentum (OAM) and spin angular momentum (SAM) degrees of freedom for a single photon leads to enhanced transmission rates and security in high-dimensional quantum key distribution (QKD) systems. Therefore, the actual commercial QKD sources require accurate and fast generation of encoded states. This paper proposes a schemed and numerically verified integrated high-speed and low-loss electro-optical modulator for the manipulation of modes encoded in OAM-SAM states. The modulator is designed as an electro-optically active lithium niobate on insulator photonic wire configuration. The obtained results indicate the high purity (>92%) and low quantum bit error rate (∼8%) generation of encoded states for 4D-QKD with structured photons via low applied voltage values not more than 9 volts.

Microstructural Characteristics and Residual Stresses in Arc-Sprayed Cermet Coatings Using Different Carbide Grain Size Fractions

Different studies have emphasized the technological relevance of residual stresses in engineered surfaces, such as thermally sprayed coatings, and their effect on the fracture and fatigue behavior. In arc-sprayed coatings, the microstructural characteristics and resulting residual stresses are determined primarily by the inherent process characteristics and feedstock material. With the scope of this work, a study on the residual stress field in coatings formed by an arc spraying process for different electric parameter settings has been carried out using different wire configurations. Thus, iron-based cored wires with different grain-sized tungsten carbides as filler material were used as feedstock. The coatings are mainly composed of eutectic carbides, and eta carbides such as M6C, M12C, or M23C and some iron-rich oxide phases, as well as characterized by an inhomogeneous, lamellar microstructure. The results demonstrated that the magnitude of the residual stresses in the coating depends on the carbide grain size fraction used as filling for cored wires. A smaller carbide grain size leads to a more pronounced dissolution of eutectic carbides, resulting in the formation of eta carbides, which in turn is accompanied by decreased tensile residual stresses across the coating. With respect to the spray parameter settings, reduced tensile residual stresses are observed when an increased voltage is applied, which can be attributed to phase evolution phenomena during spraying and thermal effects on the substrate-coating system.

Development of anti-icing airfield pavement using surface-embedded heat wire

ABSTRACTSnow and ice pose a significant risk for aircraft ground operation safety. Ploughing and chemical treatment are used for snow removal, but yield long-term detrimental impacts to the airfield infrastructure and environment. A proof-of-concept airfield heated pavement system (AHPS) prototype using near-surface embedded heat wire for pavement anti-icing is presented in this paper. Surface-embedded wires were used to study heat performance and energy warranted to maintain above-freezing slab surface temperatures. This approach concentrated heat energy to the pavement surface. Testing this AHPS prototype contained the following objectives: (1) optimise surface-embedded heat wire configuration, (2) investigate surface temperature distribution and (3) summarise system heating performance in outdoor winter conditions. Preliminary laboratory testing used a 150 mm wire spacing in a serpentine configuration. At this spacing, an energy flux of 142 W/m2 produced a 6°C temperature rise in 6 h in a −14°C freezer chest. Sufficient surface temperature rise was attained in preliminary field-testing during the 2015–2016 winter season using a 213.1–697.5-W/m2 energy range. Using the presented AHPS prototype, a 25-mm layer of crushed ice melted within 1 h during an experimental ice test.