Twisted Pair Research Articles

The objective of this study is to examine the forming performance of various material liners and improve the structure of shape charges. This paper employs numerical simulations to investigate the shape charge jet (SCJ) characteristics of three materials: TC21, AL-6XN steel, known as high nitrogen steel (HNS), and a Cu liner as a control group. A specific shape charge structure was selected for SCJ forming and penetration tests. Simulations were conducted using the Johnson-Cook model and equations of state for all three materials, which were then compared with those of the copper liner. The morphology of the SCJ for each material was analyzed in detail, focusing on parameters such as head velocity, length, and diameter. To further assess SCJ’s destructive capability, a 3D model was created to simulate two material jets penetrating C35 concrete. Test results were compared with simulation outcomes. Findings revealed that the Cu jet had the lowest velocity, followed by HNS; TC21 exhibited the highest velocity. During forming, TC21 and HNS jets showed poor cohesion leading to radial dispersion. The Cu jet penetrated deeper into concrete while TC21 produced a larger opening diameter. Experimental results aligned well with simulations, validating both methodology and findings.

Twisted wire wick structure in a novel flat heat pipe

The current study aimed to research the bioactivity of Janus-like CuO-Ag nanoparticles (NPs) against clinical isolates of Klebsiella pneumoniae. The synthesis of CuO-Ag NPs was carried out by electric explosion of two twisted wires (EETW) method. The bioactivity of Janus-like CuO-Ag NPs was assessed by the determination of antibiofilm, antiadhesion, antibiotic sensitivity effect, and cytotoxicity on 3T3 cell line. The results indicate that the antibiofilm activity of these Janus-like CuO-Ag particles at subinhibitory concentrations was found to be between 2 and 10 times more potent than that of a mechanical mixture of CuO and Ag, separated Cu and Ag. Furthermore, the effective concentrations necessary for antiadhesion activity against K. pneumoniae were significantly lower for the Janus-like CuO-Ag particles, recorded at 2.0 and 10.0µg/ml, in contrast to the control, which showed values of 7.3 ± 0.2% and 46.7 ± 0.4%, respectively (P < 0.05). Along with this, Janus-like CuO-Ag NPs increased the diameters of the antibiotic inhibition zones K. pneumoniae: for Imipenem from 5.0 ± 0.8 to 10.0 ± 1.0mm, Gentamicin from 15.0 ± 2.0 to 20 ± 2.0mm, and Amikacin from 13.0 ± 2.0 to 21 ± 2.0mm (p < 0.05). We showed that ROS generation and Ag + release made only a small contribution to the bioactivity of CuO-Ag NPs. Notably, the generation of copper ions were increased from 7,5μg/L ± 0.1% to 25 ± 1% μg/L within 24h of exposure NPs (P < 0.05). At the same time, the cytotoxicity test confirmed favorable safety profiles of the synthesized NPs.

This article presents an exploratory study of a new family of parallel mechanisms with multiscale (micro/macro) motion capabilities. These composite serial-in-parallel mechanisms use kinematic redundancy and two sets of macro and micro actuators to achieve multiscale motion. Use of twisted wire actuators (TWAs) is considered as a low-cost alternative for achieving micromotion. A kinematically redundant 3RRPR planar parallel robot is used as a case study for task-based design of these robots with considerations of macro and micromotion workspace, dexterity, minimal motion resolution, and end-effector error considering the use of low-cost TWAs for achieving micromotion. Task-based considerations for the microworkspace are used to illustrate the effect of the TWAs on the micromotion kinematics. An experimental study shows that, because of the use of TWAs, it is possible to achieve motion resolutions on the order of a few micrometers despite using low-cost manufacturing techniques and actuators. The use of TWAs is shown to also significantly alter the kinematic characteristics of the robot at the microscale. The modeling framework of this article can guide designers in key design considerations for parallel robots with multiscale motion capabilities. Results of this article can be used to guide users in the selection of TWAs and in determining the threshold when the robot should switch from macro to micromotion and to facilitate a smooth transition via redundancy resolution.

Abstract The entangled metal wire material based on multi‐strand twisted wire is a novel porous elastomeric material, which has attracted much attention in the sandwich structure core layer material due to its superior performance. In this paper, a novel ceramic/multi‐strand twisted wire‐based entangled materials (MTWEM) sandwich structure is prepared, whose core layer is divided into multi‐strand twisted spiral coil (SC‐MTWEM) and multi‐strand twisted wire mesh (WM‐MTWEM). By scanning electron microscopy (SEM) and energy‐dispersive x‐ray spectroscopy (EDS), the joint surface is revealed to be flawless, and the elemental distribution and compound composition of the joint are analyzed. The interface strength of the sandwich structure is examined by tensile tests, and the forms of damage are investigated under the macroscopic and microscopic aspects. The effects of three factors, namely the MTWEM density, MTWEM thickness, and ceramic panel thickness, on the bending resistance are investigated by a three‐point bending test. The test results indicate that the damage is dominated by the fracture of the ceramic panel and the shear deformation of MTWEM. The evolution of the damage form is verified by simulation analysis. Bending strength and energy absorption are positively correlated with MTWEM density and ceramic thickness, and the fracture of the ceramic panel is delayed. The MTWEM thickness has the opposite effect. The particular cell grid of WM‐MTWEM is interlocked and interwoven with each other. It allows the bending strength and energy absorption to be superior to that of SC‐MTWEM for the same parameters, but the timing of ceramic panel breakage is advanced.

We present the design and error analysis of a non-magnetic electric heating oven for spin-exchange relaxation-free (SERF) magnetometers, where precise thermal control and minimal magnetic disturbance are critical. A compact oven using a double-layer polyimide-constantan heating film was developed and evaluated through finite element simulations and experiments. Temperature simulations showed good agreement with measurements using a convective heat transfer coefficient of . However, a temperature difference of C was observed due to heat loss near the vapor cell stem. Adding a thermal shell in the simulation reduced this gradient to C, indicating improved thermal uniformity. Magnetic field simulations initially showed large discrepancies with experimental results. Including a twisted wire pair improved agreement, but differences remained. To further investigate the remaining discrepancies, Monte Carlo simulations were performed by introducing realistic variations in fabrication tolerances, mounting positions, and wiring configurations. The results revealed that wiring errors had the greatest influence on the measured magnetic field. These findings provide key insights into structural factors affecting magnetic performance and offer practical guidelines for reducing magnetic noise in SERF magnetometer systems.

Slight changes in the local properties of a transmission line, dipped in a liquid, can be used to estimate its level through two different determination techniques, involving the capacitance and electromagnetic wave speed, measured by the time of flight. Indeed, the overall capacitance of a transmission line varies linearly with the liquid level, as well as the time of flight of the electromagnetic wave. Both quantities can be estimated via the measurement of a phase shift at radio frequencies, and the simultaneous measurements can be realized using a compact and low-cost design working at a few megahertz. This paper presents a further improvement in sensitivity to challenge the performance of this kind of level sensor, dealing with liquids with low dielectric constants. To better describe this effect, a study on the overall capacitance of different transmission path segments was conducted in COMSOL Multiphysics. The level measurement was performed experimentally on the realized prototype while considering the measured phase shift as a function of the liquid level, for both an unshielded twisted-pair and magnet wires. As the results showed, with the magnet wires the sensitivity was improved by a factor of about 4, consistently aligning with the simulation results and providing a predictable phase shift response with increasing liquid levels. Consequently, magnet wire is a good choice for precise level measurements through RF phase shifts, especially in the case of low relative permittivity liquids.

Effect of residual nanotwin on electromigration in copper lines with bamboo-like structures

Structure and magnetic properties of Fe-Ni-Co alloy nanoparticles synthesized by an electrical explosion of twisted wires in an argon atmosphere

This article covers the subject of making modifications to an existing high-speed data transmission interface meant for using in a dangerous environment of underground mining facilities, namely, the development of a software implementation of a media converter in order to replace it. At the end of the 90-s of the last century, a specialized network interface was developed to provide communication and environmental monitoring in hazardous environments of mining facilities. It was called Siberian Board Network Interface (SBNI) and allowed long-range (up to 9 km) data transmission via single twisted pair, offering higher speeds (up to 2 Mbit/s) than interfaces based on a widely known physical standard RS-485/EIA-485.The current configuration of the interface suggests usage of a media converter which is a device that transforms Ethernet data packets into SBNI datagrams. This media converter includes electronic components that are now obsolete, expensive and unavailable on the local market. Continuous development of embedded electronics now allows replacing the media converter by a software implementation. This article contains algorithms developed for work with remote processing units in order to solve the problem. The result of the work demonstrates a possibility of enabling previously unused remote processing units to implement the logic of a media converter on them, and simplify and optimize the production process without sacrificing reliability or functionality.

Abstract Stranded cables, composed of multiple twisted wires, exhibit high tensile strength and flexibility, making them essential in numerous industrial applications, such as mooring lines for offshore structures, overhead conductors, and cable-stayed bridges. The complex interactions between individual wire strands - primarily fretting-induced frictional contact and fatigue - pose significant challenges for numerical modeling. In this context, point-wise contact interactions between wires of different layers are often critical. This study presents a new beam-to-beam small-sliding point-wise contact element tailored for modeling stranded cables under small relative sliding conditions. Unlike traditional contact formulations, the proposed approach eliminates the need for repetitive, computationally expensive contact searches by assuming small sliding amplitudes between beams, which allows for predefined node pairing. The method, implemented within a large rotation wireframe finite element framework, offers enhanced computational efficiency and maintains robustness through a smooth evolution of the contact normal, thanks to nodal cross-sectional rotations. Numerical examples demonstrate the model’s effectiveness in handling arbitrary small sliding cases.

Abstract In the pursuit of enabling the application of all-superconducting rotating machines in electric aviation, high AC loss in the armature windings where superconductors carry AC currents and exposed to AC/rotating magnetic fields is a critical stumbling block. For lowering AC loss, multifilamentary magnesium diboride (MgB2) wires with fine filaments and tight twist are one promising candidate for aviation applications. In this paper, 3D AC loss simulations of a 54-filament MgB2 wire with a non-magnetic matrix at 20 K are carried out based on the H-formulation. The transport loss carrying AC current without external field, Q t0, of 12-, 30- and 54-filament wires is firstly obtained, where the current amplitudes range from 20% to 90% of its self-field critical current I c0. Then the magnetization loss exposed to field amplitudes up to 2 T without current, Q m0, is presented, where the operational frequency, the twist pitch and resistivity of the matrix are varied to investigate their impacts on Q m0 and its three loss components (hysteresis loss Q h, coupling loss Q c and eddy current loss Q e). Lastly, the total loss, Q total, of the 54-filament wire with various twist pitches and frequencies is compared, where the current amplitudes vary from 30% to 70% of I c0 and the field amplitudes are up to 2 T. All simulations use the measured J c( B , 20 K) and n( B , 20 K) data of the 54-filament wire. Simulation results show that, the use of the 5 mm twist pitch wire can significantly reduce Q m0 due to the decoupling of the filaments, where the simulated Q h matches well with the analytical hysteresis loss for a cylindrical superconductor multiplied by 54 (the number of filaments). With increasing twist pitch, the filaments become coupled, resulting in a greater increase in both Q c and Q h. Surprisingly, the simulated Q total values in the wires with different twist pitches agree well with the sum of Q m0 and Q t0 for all different current levels. This implies that Q total in an MgB2 wire carrying an AC current exposed to an AC magnetic field can be accurately predicted by knowing Q m0 and Q t0 values which are more easily obtained.

Using of electrical explosion of two twisted wires to obtain TiO2(rutile)/TiO2(anatase)-Ag nanoparticles with high visible-light photochemical activity

The proliferation of sophisticated infotainment and driver assistance systems within modern vehicles necessitates robust highbandwidth in-vehicle networking (IVN) solutions. MOST (Media Oriented Systems Transport) emerged as a dedicated serial communication standard, specifically optimized by the automotive industry to handle the demanding requirements of multimedia data streams. This paper provides a comprehensive analysis of the MOST protocol, detailing its architecture, protocol stack, network topologies (primarily ring and daisy-chain), and physical layer options, including Plastic Optical Fiber (POF) and electrical conductors (Unshielded Twisted Pair - UTP). It examines the evolution of the standard through its key generations: MOST25, MOST50, and MOST150, highlighting the progressive increases in bandwidth and functionality, including the integration of an Ethernet channel in MOST150. The paper discusses MOST's synchronous, time-division multiplexing approach for transporting audio, video, voice, and packet data, contrasting it with other automotive networking protocols like CAN, LIN, FlexRay, and the increasingly prevalent Automotive Ethernet. The role of the MOST Cooperation in standardization and the protocol's widespread adoption by major automotive manufacturers are also addressed. While MOST significantly advanced automotive multimedia networking, its future role is considered in light of emerging technologies like Automotive Ethernet.

Abstract This paper computationally investigates partial discharges (PDs) in the form of self-sustained gas discharges. It presents two methods for predictive modeling: (1) a new low-fidelity algorithm for the PD inception voltage is introduced. The method is volume-resolved and describes both the strength of the self-sustained Townsend mechanism as well as the conventional streamer (or bulk) mechanism. It also intrinsically computes the inception region, i.e. the region where a first electron also leads to a discharge. (2) We apply a high-fidelity plasma model based on kinetic Monte Carlo, which self-consistently resolves the plasma dynamics during the PD process. The two models are complementary in the sense that the low-fidelity model provides the when and where the PD occurs, while the high-fidelity model resolves the PD process itself, starting from the first electron. Prediction and quantification of the PD processes is provided for four application cases: (1) protrusion-plane gaps, (2) spherical voids, (3) twisted wire pairs, and (4) triple junctions. Validation of the low-fidelity method is done through comparison with published experiments (where available), as well as virtual verification through comparison with the high-fidelity plasma model.

This paper presents the issues related to aging studies of electrical insulation in winding wires, which are widely used in electrical machines. Insulating materials in electrical machines are subjected to various stress factors, particularly electrical stress. The proper design of such insulation systems requires an understanding of the behavior of individual system components under specific operating conditions. This knowledge enables the optimization of insulation design, which can contribute to extending the operational lifespan of electrical machines. In this study, the results of experimental investigations on twisted-pair winding wires with different geometric dimensions, subjected to electrical stress (a square voltage waveform in the kilohertz frequency range) under different pressure conditions, are presented. The experimental research is supplemented by simulation-based calculations of the electric field intensity in the examined twisted-pair winding wire samples.

With an increase in users and devices, fast data rates are turning increasingly desirable in wired and wireless transmission. Moving towards higher frequency bands, especially in the multi-GHz region, is one potential solution to fulfil the user demands for a high data rate. Recently, it was demonstrated that using a waveguide technique and the higher order guide modes in the already established twisted pair cable, a data rate of terabits per second could be attained. The air-dielectric space inside the cable can be used to transmit the terahertz waves wirelessly. However, the idea is novel and there are quite challenges in the realization of this idea practically such as the bending effect and high attenuation due to the narrow gap. The copper wires and metallic foils inside the cable create an air space similar to the circular waveguide. Therefore, to investigate the feasibility of this cable for next-generation D band communication, a circular waveguide of similar dimensions is simulated, and the effect of bending on the propagation characteristics is studied. It is found that even a small bend in the waveguide structure has a significant effect on the performance of the waveguide. If this cable is properly excited, can be the revolutionary beginning of the high-speed internet and 6G.

Abstract We measured the frequency-dependent magnetization losses of twisted multifilament MgB2 wires subjected to ac transverse magnetic fields with a small amplitude, under which coupling loss dominates magnetization loss, and then, we determined their coupling time constants as well as their geometry factors of coupling losses at various temperatures. We also measured the hysteresis loops of their magnetizations using a vibrating sample magnetometer, and then, we calculated the hysteresis losses at various magnetic field amplitudes and at various temperatures. Note that such calculated values represent the hysteresis losses in completely decoupled filaments in a twisted multifilament MgB2 wire. Using these values obtained experimentally, we calculated the magnetization losses of twisted multifilament MgB2 wires under practical operating conditions, i.e. at various magnetic field amplitudes, at various magnetic field frequencies, and at various temperatures, considering the saturation of the filamentary region in the wire, which occurs at magnetic fields with high frequencies and large amplitudes.

Millimeter-wave and terahertz (THz) frequency bands are being explored in wired and wireless communication systems due to ongoing demands for increased data rates. Recently, it has been proposed that twisted-pair cables, already part of existing infrastructure, could be utilized for terabit-per-second data transmission by exploiting wireless THz radiation between the copper wires. THz radiation can be wirelessly transferred through the dielectric gap and the air gap in between the copper wires. The air gap and the dielectric material between the copper wires in a CAT6 (Category 6) cable can be considered a circular hollow-core waveguide, providing a suitable medium for the propagation of THz waves. Therefore, this work aims to estimate the data rate per distance by experimentally analyzing the copper circular waveguide. Furthermore, the impact of a waveguide radius is also examined. Waveguide propagation characteristics were experimentally analyzed using THz time-domain spectroscopy as well as on a simulation basis using CST (Computer Simulation Technology) Microwave Studio 2022. It was found that the radius of the waveguide has a significant effect on the transmission characteristics of the waveguide and the channel capacity for a longer range. The proposed waveguides achieved a maximum data rate in Tbps (terabits per second) for a few meters depending upon the diameter of the waveguide. This study investigates the propagation of THz waves through narrower spaces and explores the initial steps toward realizing the concept of a TDSL (Terabit Digital Subscriber Line) and future high-frequency communication systems.

Abstract In this work, a self‐healing elastomer involving reversible imine bonds was synthesized by Schiff base reaction between the amino groups in amino‐modified polydimethylsiloxane (APDMS) and the aldehyde groups in 1,4‐diformylbenzene (DFB). The incorporation of amino‐modified multi‐walled carbon nanotube (AMWCNT) allowed for good dispersion of AMWCNT with few aggregates and effectively balanced the mechanical properties and self‐healing performance, achieving a mechanical strength of 132.3 kPa and a self‐healing efficiency (HE) of 99.87% at room temperature after 24 h. The reversible imine bond based on the Schiff base linkage promotes quick self‐healing upon damage without any external stimulus at room temperature. Through electroless deposition, copper and nickel patterns were formed on the surface of the elastomer, establishing conductive pathways. The average resistivity of the copper trace was 5.40 × 10−8 Ω·m (3.63 × 10−7 Ω·m for nickel trace), which is 3.18 times that of regular copper wire (5.19 times for regular nickel wire). Upon cleavage and self‐healing of the elastomer with copper lines, with the resistivity increment by 14.43% in average (11.01% for nickel wire). This work offers an alternative pathway to the development of self‐healable silicone elastomers for future flexible electronics.Highlights Elastomer with balanced mechanical properties and self‐healing performance. Recyclable elastomer through hot‐press treatment. Copper patterns were electroless‐deposited on the elastomer. Damaged pattern restored conductivity within 24 h at room temperature.