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An Al-Fe alloy which was produced by hot extrusion of rapidly solidified powder is a possible solution to substitute copper-based electrical conductor material due to its high strength and high electrical conductivity. However, the stress relaxation characteristic—an essential parameter as a conductor material—and the effect of the material structure have not been reported, which was the aim of the present paper. An Al-5%Fe alloy was selected as the test material. The material structures were controlled by hot extrusion practice, annealing, and cold rolling. The Al-Fe intermetallic compound particles controlled the residual stress after the stress relaxation test via the Orowan mechanism. Decreasing the mean inter-particle distance reduces the electrical conductivity. The increase in the number of dislocations by the cold rolling increased strength at room temperature without changing electrical conductivity; however, it did not have a positive effect on the stress relaxation characteristics. The stress relaxation characteristics and the electrical conductivity of the Al-Fe alloy were superior to conventional C52100 H04 phosphor bronze when compared with the case of the same mass. [ABSTRACT FROM AUTHOR]

Rapidly solidified Al-Fe alloys produced by hot extrusion are a promising replacement for copper-based electrical conductors because of their light weight. However, the effects of the extrusion temperature conditions on the mechanical and electrical properties of extruded materials are unknown. The present work investigated the effects of billet preheating temperature, in situ temperature during extrusion, and additional heat treatment after extrusion on hardness and electrical conductivity. An air-jet atomized Al-2.3%Fe alloy powder was pre-sintered into cylindrical billets and then hot-extruded. The hardness of the extrudates decreased as the in situ temperature during extrusion increased above 650 K. The billet preheating temperature affected the in situ temperature during extrusion. Additional annealing after extrusion decreased the hardness. The cause of the decrease in hardness was coarsening of the grain of the aluminum matrix. The electrical conductivity increased with higher billet preheating temperatures before extrusion or additional annealing after extrusion; however, an in situ temperature rise for a few seconds during extrusion did not affect the conductivity. The increase in electrical conductivity was considered to be caused by a decrease in the amount of solute iron, which requires holding the material at a high temperature for longer than several minutes. [ABSTRACT FROM AUTHOR]

Square planar transition metal bis(dithiolene) complexes are of upsurge interest throughout the last few decades due to their varied interesting physical as well as physicochemical properties. Random studies on design and synthesis of semiconducting materials based on metal dithiolene complexes are going on. Moreover, shift at intense Near Infrared (NIR) region, high electrical conductivity, non-linear optical activity, electrochemical behaviours etc. are some of its interesting activities. It is important to note that a minute tailoring in its ligand backbone (which results change in its electron delocalization) results in appreciable amount of variation in its physicochemical behaviour. In this present endeavour, research works on synthesis, solid-state electrical conductivity and NIR absorption studies of square planar transition metal dithiolene complexes from near past to present days have been discussed with survey of recent work and its futuristic applications so far. [ABSTRACT FROM AUTHOR]

This work presents macroscopic fibers of aligned double-walled carbon nanotubes (DWCNTs) intercalated with long-range ordered bromine, with a stoichiometry close to C 17 Br. Tribromide ions lie inside interstitial sites between hexagonally-packed DWCNTs and extend parallel to their axis as ordered supramolecular "wires". First-principles simulations confirm this structure and a transfer of 0.13 electrons per Br atom. The structure of nested bundles of CNTs with a homogeneous distribution of bromine species in the interstitial sites of the superlattice is directly imaged by cross-sectional HRTEM, showing full intercalation of highly dense and aligned fibers. The presence of Br 2 and B r 3 – is confirmed by Raman spectroscopy, and their supramolecular organization is resolved by 2D wide-angle X-ray scattering. Intercalation increases room-temperature longitudinal electrical conductivity by a factor of 8.4. Through low-temperature transport measurements in the longitudinal and transverse directions, we show that the intercalate reduces the tunneling-dominated resistance associated with transport between adjacent CNTs, rather than exclusively acting as a dopant that increases conductance of individual CNTs. By preserving the separation between CNTs, the exceptional mechanical properties of the CNT fiber host are retained. The combined tensile strength above 2.46 GPa and conductivity of 10.68 MS/m makes intercalated CNT fibers attractive lightweight conductors with combined properties superior to metals and graphite intercalation compounds. [Display omitted] [ABSTRACT FROM AUTHOR]

The Delhi Seismic Zone (DSZ) is a seismically highly active intraplate region that keeps experiencing recurrent seismicity of minor to moderate nature. The seismic activity in the DSZ in recent times has evoked concerns about the vulnerability of the region due to potential earthquakes. Although the spatial distribution of recorded earthquakes gives a fairly good idea about the zone of the seismicity, the information about the underlying crustal structure and seismogenic faults is largely missing. In the present work, we have revisited the MT data acquired at various locations across Haryana to understand whether there are any anomalous features in the crust that might correlate with the seismicity in the western part of the DSZ. The MT data recorded at six groups of sites yielded good impedance tensors in the period range of 0.001–1000 s. A significant result obtained by 2-D inversion of distortion corrected impedance tensors is the presence of a northward dipping electrical conductor (<10 Ωm) from the surface down to about 20–25 km depth. The surface location of this conductor is in the proximity of the northern edge of the inferred Delhi–Sargodha Ridge. The DSZ earthquakes, when projected onto the MT profile, coincide with the north dipping conductor. We infer that the conductor is possibly extending into the DSZ and has an important role in the occurrence of the seismicity, at least in the western part of the region and that the increased electrical conductivity is possibly due to the presence of crustal fluids. [ABSTRACT FROM AUTHOR]

The development of a six-axis load head based on the Stewart platform concept is described in this paper. The intended application of the device is in quantifying terminal forces and moments in flexible conductors interconnecting equipment in electrical substations. Such quantification is important is assessing seismic demand both at the terminal connections and in the equipment. In particular, nonlinear effects have been observed in the dynamics of such interconnected systems, and the load head is designed to capture such effects. For this purpose, it has a large range, thus being able to record force spikes, as well as high sensitivity needed to measure low-level fluctuations that influence equipment base moments. Performance of the load head is assessed through static and dynamic tests, and implications of design modifications on performance are explored. An example application of the load head to a dynamic test is presented, where a conductor is fixed at one end and excited at the other. Results demonstrate the ability of the load head to capture nonlinear dynamic effects. Specifically, force and moment characteristics as nonlinear effects develop in the form of period-doubling are reported. A physical understanding of these phenomena is invaluable in interpreting characteristics observed in flexibly interconnected equipment. [ABSTRACT FROM AUTHOR]

The present review will introduce the basic concepts of silk-based electronics/optoelectronics including the latest technological advances on the use of silk fibroin in combination with other functional components, with an emphasis on improving the performance of next-generation silk-based materials. It also highlights the patterning of silk fibroin to produce micro/nano-scale features, as well as the functionalization of silk fibroin to impart antimicrobial (i.e. antibacterial) properties. Silk-based bioelectronics have great potential for advanced or futuristic bio-applications including e-skins, e-bandages, biosensors, wearable displays, implantable devices, artificial muscles, etc. Notably, silk-based organic field-effect transistors have highly promising applications in e-skins and biosensors; silk-based electrodes/antennas are used for in vivo bioanalysis or sensing purpose (e.g., measurement of neurotransmitter such as dopamine) in addition to their use as food sensors; silk-based diodes can be applied as light sources for wound healing or tissue engineering, e.g., in cutaneous wound closure or induction of photothrombosis of corneal neovascularization; silk-based actuators have promising applications as artificial muscles; whereas silk-based memristors have exciting applications as logic or synaptic network for realizing e-skins or bionic brains. [ABSTRACT FROM AUTHOR]

This paper is on nonlinear dynamics of flexible conductors that interconnect equipment in high-voltage substations. Such nonlinear dynamics play a role in the response of substation equipment to earthquake excitation, and characterizing them is important when considering seismic safety of substation equipment in codes of practice. The focus of this paper is on nonlinear dynamic effects in individual conductors; implications for interconnected system response are a topic of our current work. Four conductor types are considered at different levels of slack, and subject to uniaxial harmonic excitation of multiple frequency–amplitude combinations. It is observed from experiments that a large variety of nonlinear dynamic behaviors occur, depending on slack level, excitation frequency and amplitude, resulting in significant out-of-plane motion and large conductor terminal forces. To explain some of these nonlinear effects, a simplified mathematical model is described, and 2:1 resonance is demonstrated using perturbation and continuation methods. Equipped with this understanding of individual conductor nonlinear dynamics, interconnected system dynamics can be better characterized towards adapting recommended practices for seismic design of substation equipment. • Short-span flexible bus conductors exhibit a large variety of nonlinear dynamics. • Conductor nonlinear dynamics affect seismic responses of interconnected equipment. • Large conductor terminal forces occur at the stability transition boundary. • The nonlinear dynamics vary as a function of slack, input frequency and amplitude. • The 2:1 resonance is demonstrated using perturbation and continuation methods. [ABSTRACT FROM AUTHOR]

The use of solution-processable electrically conducting films is imperative for realizing next-generation flexible and wearable devices in a large-scale and economically viable way. However, the conventional approach of simply complexing metallic nanoparticles with a polymeric medium leads to a tradeoff between electrical conductivity and material properties. To address this issue, in this study, a novel strategy is presented for fabricating all-solution-processable conducting films by means of metal/polyelectrolyte complexation to achieve controlled electrical percolation; this simultaneously imparts superior electrical conductivity and good mechanical properties. A polymeric matrix comprised of polyelectrolyte multilayers is first formed using layer-by-layer assembly, and then Ag nanoparticles are gradually synthesized and gradationally distributed inside the polymeric matrix by means of a subsequent procedure of repeated cationic exchange and reduction. During this process, electrical percolation between Ag nanoparticles and networking of electrical pathways is facilitated in the surface region of the complexed film, providing outstanding electrical conductivity only one order of magnitude less than that of metallic Ag. At the same time, the polymer-rich underlying region imparts strong, yet compliant, binding characteristics to the upper Ag-containing conducting region while allowing highly flexible mechanical deformations of bending and folding, which consequently makes the system outperform existing materials. [ABSTRACT FROM AUTHOR]

In this study, we prepared high-performance printable, stretchable electrical conductor from waterborne polyurethane and micro-silver flakes. The solidification and thermal degradation were investigated using differential scanning calorimetry and thermogravimetric analysis methods. The electrical conductor achieved solidification by volatilizing and removing the free water. The thermal degradation mainly happened in the range of 250-450 °C caused by the pyrolysis of the polymeric matrix of polyurethane. The pyrolysis kinetic equations were obtained using the kinetic methods, e.g., d α/d t = e(1 − α) αe for the polyurethane, d α/d t = e(1 − α) αe, d α/d t = e(1 − α) αe, and d α/d t = e(1 − α) αe for the electrical conductor containing 80, 85, and 90 % mass percentage of micro-silver flakes, where α was the fractional extent conversion at a given time t (or a given temperature T). Their overall order of reaction was 0.91, 0.95, 0.83, and 0.87, respectively, less than 1, demonstrating the thermal degradation was a single, simple reaction. [ABSTRACT FROM AUTHOR]

Real‐time thermal ratings (RTTRs) is an emerging technique used to calculate the rating of electrical conductors based on local, real‐time weather conditions; this leads to an increased rating with respect to conventional approaches the majority of the time, and can be used to increase the energy yield of distributed generators, support the network during outages and defer network reinforcement. Unfortunately it is not presently recognised in network planning, design and security of supply standards. This represents a barrier to utilising RTTRs in power networks, and must be addressed. This study presents a new, probabilistic method for accounting for the variable ratings during network planning. This is coupled with an analysis of the risk of being unable to supply customers in a network adopting variable ratings, compared with the risk in the same network using conventional ratings; hence the method proposed in this study allows additional load to be connected to the network at a quantified level of risk. Finally, this method could be applied to other emerging network technologies and techniques such as demand side management or energy storage. [ABSTRACT FROM AUTHOR]

Electrochemical oxidation of [CoIII(Pc)X2]− yields highly conducting partially oxidized salt crystals. Their crystal structures and dimensionality of the π–π interaction (electronic system) vary by the cationic species in the salts; one-dimensional for TPP (tetraphenylphosphonium) or PTMA (phenyltrimethylammonium) cations, and ladder and two-dimensional for the PXX (peri-xanthenoxanthene) radical cation. Substitution of the axial group (X) or extension of the π-conjugated macrocycle (Pc) has been found to influence the magnitude of the π–π stacking interactions. Their electrical properties characterized by the conductivity and thermoelectric power measurements are found to be dependent on the dimensionality and the magnitude of π–π stacking interactions. [Copyright &y& Elsevier]

Recent progress in the metallic conducting Langmuir–Blodgett (LB) films built from TTF derivative and fatty acids is reported. A simple LB method of transferring the mixed Langmuir (L) film of BEDO-TTF (BO) and stearic acid (SA) onto substrates provided metallic conducting LB films. A homogeneous L film formation on the water surface observed by Brewster angle microscope (BAM) is an essential factor for the well-ordered LB films. In the L film, the carboxylate group of fatty acid forms anion layer bringing about a spontaneous formation of mixed valence state (MVS) of BO layer. Similar spontaneous formation was also found in the molecular combination of nonoxygen-substituted donor of EDT-TTF and octadecanesulfonic acid (OS). This type of reaction would be useful for obtaining conducting LB films. For the LB films of BEDO-TTF and stearic acid, we found a negative transverse magnetoresistance at low temperature that was interpreted in the weak localization of a two-dimensional (2D) electronic system based on the well-defined conducting layer. [Copyright &y& Elsevier]