Continuous Wire Research Articles

Analog Control of Continuous Copper Wire Annealing Based on Temperature Detecting

The paper acquires the equivalent relation between the velocity of wires and annealing temperature through deduction, based on the measurement of the annealing temperature. A controller characterizing annealing temperature could be inserted before the traditional PI annealing controller, so that annealing temperature could be controlled while the annealing temperature deviation is simulated by the error of the velocity of wires. In the paper, a kind of analog circuit is chosen to achieve the equivalent relation between the velocity of wires and annealing temperature by linear fitting under the condition of preciseness.

Design and Implementation of Sensor for Velocity of Detonation Measurement

Velocity of Detonation (VOD) is the most important property to consider when rating an explosive. It is an established fact that VOD gives a good indication of the strength and hence the performance of the explosive. Detonation Sensor is the most critical part of the VOD measurement system. This paper presents and discusses various practical and field implemental techniques for sensing detonation wave with detailed study of electrical ionization principle using resistance sensor for VOD measurement. In this technique effort is made to overcome the limitation of continuous wire sensor and discrete points sensor under various practical conditions. Step change in resistance is utilised to increase the system reliability, improve noise immunity as well as to reduce the system complexity.

К вопросу определения текущей частоты импульсов при удалении гололеда с проводов линий электропередач электродинамическим способом

In this article a new method of power transmission wire’s deicing is described. The necessity of continuous wire’s free oscillation’s frequency’s determination in the course of wire’s cleaning is shown. Based on the results of the experimental research, it is shown, that wire’s free oscillation’s frequency depends on the mass distribution of ice along the span. The technique of current pulses determination, based on use of the special correction index, is offered. An integral index for identification of functional dependence between correction index value and current ice cover condition is offered. This integral index allows to estimate the degree of mass distribution irregularity along the span. The frequency variation dependence of the integral index, based on the experimental data, described some typical situations on power transmission line, is determined.

Water access points and hydration pathways in CLC H + /Cl − transporters

CLC transporters catalyze transmembrane exchange of chloride for protons. Although a putative pathway for Cl(-) has been established, the pathway of H(+) translocation remains obscure. Through a highly concerted computational and experimental approach, we characterize microscopic details essential to understanding H(+)-translocation. An extended (0.4 µs) equilibrium molecular dynamics simulation of membrane-embedded, dimeric ClC-ec1, a CLC from Escherichia coli, reveals transient but frequent hydration of the central hydrophobic region by water molecules from the intracellular bulk phase via the interface between the two subunits. We characterize a portal region lined by E202, E203, and A404 as the main gateway for hydration. Supporting this mechanism, site-specific mutagenesis experiments show that ClC-ec1 ion transport rates decrease as the size of the portal residue at position 404 is increased. Beyond the portal, water wires form spontaneously and repeatedly to span the 15-Å hydrophobic region between the two known H(+) transport sites [E148 (Glu(ex)) and E203 (Glu(in))]. Our finding that the formation of these water wires requires the presence of Cl(-) explains the previously mystifying fact that Cl(-) occupancy correlates with the ability to transport protons. To further validate the idea that these water wires are central to the H(+) transport mechanism, we identified I109 as the residue that exhibits the greatest conformational coupling to water wire formation and experimentally tested the effects of mutating this residue. The results, by providing a detailed microscopic view of the dynamics of water wire formation and confirming the involvement of specific protein residues, offer a mechanism for the coupled transport of H(+) and Cl(-) ions in CLC transporters.

Polyethylene naphthalate as an excellent candidate for ripple nanopatterning

The surface of polyethylene naphthalate (PEN) foils was exposed to KrF excimer laser treatment. Due to presence of condensed benzene rings has this polymer better mechanical, chemical and thermal properties in comparison to polyethylene terephthalate, which is widely applicable in electronic devices and also as tissue cell carriers. The influence of laser fluence and number of laser pulses on surface chemistry and morphology was determined. The surface morphology was studied with atomic force microscopy (AFM) in combination with scanning electron microscopy and focused ion beam (FIB-SEM). Surface wettability was characterized by the contact angle measurement. Surface chemistry was evaluated from XPS spectra. The optimal PEN process parameters with the most regular pattern were determined. The foils with optimal ripple pattern were consequently sputtered with gold nanolayers of 100nm thickness. The parameters of ripple pattern after the metallization were introduced. It was found that the gold nanolayer is formed of electrically continuous wires, the ripple pattern was maintained.

FABRICATION AND CHARACTERIZATION OF Ni–Mn–Si–Al–O NTC THERMISTOR AND ITS APPLICATION AS TEMPERATURE WIRE SENSOR

A series of Al 2 O 3 substituted manganese oxide ceramic compounds, Ni 0.6 Si 0.2 Mn 2.2-x Al x O 4(0 ≤ x ≤ 0.6), were prepared by solid-state reaction route. The phase composition, microstructure, and electrical properties of compounds were studied. The results revealed that all the compounds were composed of cubic spinel structure without any other oxides. Besides they exhibited a linear relationship between logarithm of electrical resistivity (ln ρ) and reciprocal of absolute temperature (1/T) over a temperature ranging from room temperature to 300°C, which indicated a negative temperature coefficient (NTC) characteristic. The B25/85 constant was found to increase with the increase of Al 2 O 3 content. The B25/85 values of the NTC Ni 0.6 Si 0.2 Mn 2.2-x Al x O 4 thermistors for x = 0,0.1,0.2,0.3,0.4, and 0.6 were 4581, 4612, 4680, 4875, and 5089 K, respectively. Finally, a new method to produce one meter long continuous fire wire sensors was also proposed.

Lowering plasma frequency by enhancing the effective mass of electrons: A route to deep sub-wavelength metamaterials

Deep sub-wavelength metamaterials are the key to the further development of practical metamaterials with small volumes and broadband properties. We propose to reduce the electrical sizes of metamaterials down to more sub-wavelength scales by lowering the plasma frequencies of metallic wires. The theoretical model is firstly established by analyzing the plasma frequency of continuous thin wires. By introducing more inductance elements, the effective electron mass can be enhanced drastically, leading to significantly lowered plasma frequencies. Based on this theory, we demonstrate that both the electric and the magnetic plasma frequencies of metamaterials can be lowered significantly and thus the electrical sizes of metamaterials can be reduced to more sub-wavelength scales. This provides an efficient route to deep sub-wavelength metamaterials and will give rigorous impetus for the further development of practical metamaterials.

Symmetric metamaterials based on flower-shaped structure

We proposed new models of metamaterials (MMs) based on a flower-shaped structure (FSS), whose “meta-atoms” consist of two flower-shaped metallic parts separated by a dielectric layer. Like the non-symmetric MMs based on cut-wire-pairs or electric ring resonators, the symmetrical FSS demonstrates the negative permeability at GHz frequencies. Employing the results, we designed a symmetric negative-refractive-index MM [a symmetric combined structure (SCS)], which is composed of FSSs and cross continuous wires. The MM properties of the FSS and the SCS are presented numerically and experimentally.

Effect of Nb on the corrosion behavior of continuous bulk metallic glass-coated steel wire composites

(Zr41.2Ti13.8Cu12.5Ni10Be22.5)100−xNbx (at%, x=0 and 8) bulk metallic glasses (BMGs) were coated on the surface of Q195 steel wires by a continuous coating process. The potentiodynamic polarization tests of these BMGs were conducted in 3.5wt% NaCl aqueous solution. It is found that the addition of 8at% Nb into Zr41.2Ti13.8Cu12.5Ni10Be22.5 alloy results in the improvement of corrosion resistance with the pitting potential of −52 mV, the open circuit potential of −446 mV, and the corrosion current density of 9.86×10−6 mA/cm2. This may be attributed to that Nb is beneficial to passivate and stabilize Zr and Ti.

Micron-scale copper wires printed using femtosecond laser-induced forward transfer with automated donor replenishment

We demonstrate the use of laser-induced forward transfer (LIFT) in combination with a novel donor replenishment scheme to print continuous copper wires. Wires of mm length, a few microns wide and submicron in height have been printed using a 800 nm, 1 kHz repetition rate, 150 fs pulsed laser. A 120 nm thick copper donor was used along with laser pulse energy densities of 0.16-0.21 J cm−2 to print overlapping few-micron sized pads to form the millimeter long wires. The wires have a measured resistivity of 17 ± 4 times that of bulk copper.

Chain Conformation of Poly[2-(methacryloyloxy)ethyltrimethylammonium chloride] in Aqueous Sodium Chloride Solutions

A series of poly[2-(methacryloyloxy)ethyltrimethylammonium chloride] (PMTAC) in aqueous NaCl solutions with a weight-average molecular weight (Mw) of between 6.0 × 103 and 1.5 × 105 were characterized by synchrotron radiation small-angle X-ray scattering (SAXS) and dynamic light scattering (DLS) measurements at 298 K. The hydrodynamic radius (RH) of PMTAC initially decreased with increasing salt concentration (Cs) and then leveled off at Cs = 0.5–1.0 M. The values of z-average root-mean-square radius of gyration (⟨S2⟩z1/2) simply increased with a decrease in Cs for Mw > 2 × 104 g/mol. In contrast, the values of ⟨S2⟩z1/2 for Mw < 2 × 104 g/mol increased with an increase in Cs probably because of a change in local conformation of PMTAC chain. To study local chain conformation of PMTAC, scattering functions and Mw dependences of ⟨S2⟩z1/2 and RH for PMTAC were analyzed in terms of the helical wormlike chain (HW) model which is a simple continuous elastic wire model with bending and torsional energies. The cha...

Metamaterial Tunable Filter Design

This paper presents a new concept to implement a tunable filter metamaterial with dual negative refraction composed of ferrite slabs and metallic resonators, including split-ring resonators (SRR), and short wire pairs. The ferrite slabs under an applied magnetics bias provide one magnetic resonance frequency band and the metallic resonators provide another one. The continuous wires within the metamaterials provide the negative permittivity in a wide frequency band covering the two magnetic resonance bands. This type of metamaterialis analyzed in detail, and tunable stop band filters are successfully designed. The effective electromagnetic parameters obtained from the simulation of the S-parameters indicate that metamaterial exhibit negative refraction bands, which can be shifted by changing the magnetic bias.

Differential uncertainty analysis for evaluating the accuracy of S-parameter retrieval methods for electromagnetic properties of metamaterial slabs

We apply a complete uncertainty analysis, not studied in the literature, to investigate the dependences of retrieved electromagnetic properties of two MM slabs (the first one with only split-ring resonators (SRRs) and the second with SRRs and a continuous wire) with single-band and dual-band resonating properties on the measured/simulated scattering parameters, the slab length, and the operating frequency. Such an analysis is necessary for the selection of a suitable retrieval method together with the correct examination of exotic properties of MM slabs especially in their resonance regions. For this analysis, a differential uncertainty model is developed to monitor minute changes in the dependent variables (electromagnetic properties of MM slabs) in functions of independent variables (scattering (S-) parameters, the slab length, and the operating frequency). Two complementary approaches (the analytical approach and the dispersion model approach) each with different strengths are utilized to retrieve the electromagnetic properties of various MM slabs, which are needed for the application of the uncertainty analysis. We note the following important results from our investigation. First, uncertainties in the retrieved electromagnetic properties of the analyzed MM slabs drastically increase when values of electromagnetic properties shrink to zero or near resonance regions where S-parameters exhibit rapid changes. Second, any low-loss or medium-loss inside the MM slabs due to an imperfect dielectric substrate or a finite conductivity of metals can decrease these uncertainties near resonance regions because these losses hinder abrupt changes in S-parameters. Finally, we note that precise information of especially the slab length and the operating frequency is a prerequisite for accurate analysis of exotic electromagnetic properties of MM slabs (especially multiband MM slabs) near resonance regions.

Modulating Sub-THz Radiation with Current in Superconducting Metamaterial

We show that subterahertz transmission of the superconducting metamaterial, an interlinked two-dimensional network of subwavelength resonators connected by a continuous superconducting wire loop, can be dynamically modulated by passing electrical current through it. We have identified the main mechanisms of modulation that correspond to the suppression of the superconductivity in the network by magnetic field and heat dissipation. Using the metamaterial fabricated from thin niobium film, we were able to demonstrate a transmission modulation depth of up to 45% and a bandwidth of at least 100 kHz. The demonstrated approach may be implemented with other superconducting materials at frequencies below the superconducting gap in the THz and subterahertz bands.

Dual-band left-handed metamaterials fabricated by using tree-shaped fractal

A method of fabricating dual-band left-handed metematerials (LHMs) is investigated numerically and experimentally by single-sided tree-like fractals. The resulting structure features multiband magnetic resonances and two electric resonances. By appropriately adjusting the dimensions, two left-handed (LH) bands with simultaneous negative permittivity and permeability are engineered and are validated by full-wave eigenmode analysis and measurement as well in the microwave frequency range. To study the multi-resonant mechanism in depth, the LHM is analysed from three different perspectives of field distribution analysis, circuit model analysis, and geometrical parameters evaluation. The derived formulae are consistent with all simulated results and resulting electromagnetic phenomena, indicating the effectiveness of the established theory. The method provides an alternative to the design of multi-band LHM and has the advantage of not requiring two individual resonant particles and electrically continuous wires, which in turn facilitates planar design and considerably simplifies the fabrication.

Optimization of process parameters for developing FeCoSiB amorphous microwires through in-rotating-water quenching technique

The effects of process parameters for the in-rotating-water quenching technique have been investigated with respect to structural, magnetic and giant magneto-impedance (GMI) properties of FeCoSiB alloy microwires. Continuous and ductile amorphous wires have been found with the optimization of process parameters. The structural, magnetic and GMI behaviors have been evaluated as a function of wire diameter. The crystallinity of the wires increases with wire diameter, affecting soft magnetic and GMI properties. Consequently, it is found that the wire of 110 μm diameter shows superior soft magnetic and GMI properties.

EComment. The number of sternal wires influences sternal wound outcome

I read with great interest the report of Kamiya and associates [1], looking into the impact of the number of simple sternal wires on the incidence of deep sternal wound infection (DSWI). The authors showed that the number of wires used has an association to DSWI, only in high-risk patients. Shaikhrezai [2] and colleagues reached the same conclusion, applied however, to every patient without identification of high-risk groups. In our practice, from February 2000 to October 2007, 120 out of 3896 cardiac surgical patients (3.02%; prospective data collection, sternal closure with 6 simple wires) developed sternal wound infections. Fifty-two patients (1.34%) developed DSWI. The incremental risk factors for development of DMWI were: insulin-dependent diabetes (OR= 3.62, CI= 1.2-10.98), preoperative Creatinine> µmol/L or 2.27 mg/dL (OR= 3.33, CI= 1.14-9.7) and prolonged ventilation (OR= 4.16, CI= 1.73-9.98). Overall mortality for the DMWI was high at 9.3% (11 patients). Wound microbiology revealed Staphylococcus aureus (32%), coagulase-negative Staphylococcus (29.6%), methicillin-resistant S. aureus (MRSA) (2.3%), Vancomycin-resistant Enterococcus (VRE) (3.8%), Gram negative bacteria (17.5%) and other [14.8% (Anaerobes 1.2%, Fungal 4%)]. We believe that a major factor for the development of DSWI is bony instability, which is directly related to surgical technique. Therefore, over the last 3 years, I have changed my practice by routinely using at least 8 simple wires for sternal closure. Out of 375 cases that received 8 or more sternal wires the incidence of DSWI was 0.8% (3 patients). Moreover, out of this cohort, 13 patients returned to intensive care unit with the sternum open due to haemodynamic instability and underwent delayed closure after 3 ± 4 days. Only one patient in this group developed DSWI and was treated successfully with a vacuum-assisted therapy (VAC) pump. Therefore, in conclusion, I fully agree with the above authors. I would also like to add the following technical points of great importance (together with optimal perioperative glycaemic control) in order to eliminate DSWI: Routine use of 8 simple wires or more: Loop wires may have a role in patients above 90 kg or a body mass index >38 kg/m2 and a non-osteoporotic sternum. If the bone is split in a paramedian oesteotomy, then I would suggest reinforcement of the thinner side with a Robicsek loop or the use of a modified technique by placing a line of continuous wire sutures on either side of the sternum and tying both lines cranially and caudally to avoid strangulation of the blood supply with the closed loop. Avoid fracturing or damaging the bone with sternal retractor: If the bone is friable and oesteoporotic, we use retractors with wider blades. We routinely repair fractures with simple wires prior to sternal wiring. We routinely “wash out” the high-risk cases with a Vancomycin-rifambicin solution. Finally, post-cardiac surgery sternal wound complications remain challenging. Efforts should focus on preventing sternal instability by taking into account all the aforementioned measures. Conflict of Interest: None declared

{Demonstrate the Double Negative Behavior of Metamaterial Using the Effective Medium Theory

We fabricated the electric and magnetic metamaterial, and measured their transmission spectra. The electromagnetic response of the combined structure, which consists of cut-wire pair and continuous wire, are experimentally and numerically studied in the microwave frequency regime. The simulations are performed in a qualitative agreement with experiment utilizing the transfer-matrix method. The double negative behavior of combined structure is observed and demonstrated using the effective medium theory.

Multi-band left-handed metamaterial inspired by tree-shaped fractal geometry

We report an alternative method of designing a new metamaterial with left handed (LH) characteristics over multi-band (MB) frequencies at microwave frequency regime. The resultant LH metamaterial (LHM) consisting of a single-sided tree-shaped fractal structure features triple magnetic resonances and one electric resonance apart from the lower metal plasma response, which is responsible for the three bands of negative refraction. The multi-resonant mechanism has been systematically studied to account for all electromagnetic behaviors, and capacitor–inductor circuit models are put forward for quantitative analysis. The LHM is balanced in the fundamental passband when only one layer is utilized, whereas the balanced condition is slightly broken when a collection of sub-wavelength cells are cascaded. The negative-zero-positive refraction of the fundamental LH band and the negative refraction of the higher LH band have been numerically validated by a prism-like LHM. For demonstration, a three-layer LHM slab sample is fabricated and measured. Consistent numerical and experimental results are observed. The method not requiring individual resonant particles and electrically continuous wires paves the way for a new route to compact MB LHM design.

Multi-Functional Antennas Based on Meta-Surfaces

The design of a multi-functional antenna based on meta-surfaces is investigated. The proposed structure consists of a wideband dipole antenna located between two meta-surfaces working in different frequency bands. The result is an antenna with enhanced gain that radiates in a different half-space at each frequency band. A prototype composed of an elliptical dipole and two meta-surfaces formed by grids of cut and continuous wires demonstrates that the proposed antenna discriminates the radiation in different half-spaces, as well as increases the gain of a nearly omnidirectional dipole to values 8.9 dBi and 7.7 dBi for the top and bottom half-spaces, respectively. Moreover, the antenna remains planar with total thickness of 0.13λ at the lowest resonant frequency.