Numerical Analysis of the Influence of Turbulence Intensity on Iced Conductors Gallop Phenomena

Turbulence is expected to play a relevant role in the so-called conductor gallop phenomena,namely,the high-amplitude,low-frequency oscillation of overhead power lines due to the formation of ice structures and the ensu-ing effect that wind can have on these.In this work,the galloping time history of a wire with distorted(fixed in time)shape due to the formation of ice is analyzed numerically in the frame of afluid-solid coupling method for different wind speeds and levels of turbulence.The results show that the turbulence intensity has a moderate effect on the increase of the conductor’s aerodynamic lift and drag coefficients due to ice accretion;nevertheless,the corresponding changes in the torsion coefficient are very significant and complicated.A high turbulence intensity can affect the torsion coefficient in a certain range of attack angles and increase the torsion angle of the conductor.Through comparison of the galloping phenomena for different wind velocities,it is found that the related amplitude grows significantly with an increase of the wind speed.For a relatively large wind speed,the galloping amplitude is more sensitive to the turbulence intensity.Moreover,the larger the turbulence intensity,the larger the conductor’s vertical and horizontal galloping amplitudes after icing.The torsion angle also increases with an increase in the wind speed and turbulence intensity.

Present Status of the Development and Application of Transparent Conductors Oxide Thin Solid Films

Luis Casta&ntildeeda’s article, 'Present Status of the Development and Application of Transparent Conductors Oxide Thin Solid Films ', has been retraced by Ray Boxman because of plagiarism. The scientific community takes a very strong view on this matter and we treat all unethical behavior such as plagiarism seriously. This paper published in Vol.2 No.9 1233-1242, 2011, has been removed from this site.

MODES COMPUTATION AND ANALYSIS FOR LONG MULTI-SPAN BUNDLE CONDUCTORS OF POWER TRANSMISSION LINES WITH GALLOPING CONTROL DEVICES

A new type of element which is suitable for solving the modes of the galloping long multi-spanbundle conductor structures is presented.The element is composed of all sub-conductor segments betweentwo spacers.Based on the linearized governing differential equations of the conductors,the mass matrix andstiffness matrix of the element in consideration of the constrained relations imposed on the conductors byspacers are derived.The dynamic characteristics of the galloping control devices can be directly added to theelement.The modes for an actual power line structure are computed by using the element formula and FEMprocedures,where seven cases of different galloping control device allocations are considered.Comparedwith the measured data,the method is shown to be reliable and effective.Analysis and discussions of thecomputational results are given.Some hints that are helpful to further investigation of galloping are also ob-tained.

Experimental Study on the Influence of Cross-Section Type of Marine Cable Conductors on the Bending Performance

Through the development of marine energy,marine cables are the key equipment for transmission of electrical energy between surface platforms and underwater facilities.Fatigue failure is a critical failure mode of marine cables.The bending performance of the cable conductor has a major influence on both bending and fatigue performances of the overall cable structure.To study the influence of different types of the conductor cross-section on the bending performances of marine cable conductors,three types of copper conductors with the same cross-sectional area,i.e.,noncompressed round,compressed round,and shaped wire conductors,were selected.The experimental results demonstrated that the cross-section type significantly affects the bending performances of copper conductors.In particular,the bending stiffness of the shaped wire conductor is the highest among the three conductor types.Four key evaluation parameters,i.e.,the bending stiffness,maximum bending moment,envelope area,and engineering critical slip point,were selected to compare and analyze the bending hysteresis curves of the three copper conductors.The differences in the key evaluation parameters were analyzed based on the structural dimensional parameters,processing methods,and classical bending stiffness theoretical models of the three copper conductor types.The results provide an important theoretical guidance for the structural design and engineering applications of marine cable conductors.

IONIC CONDUCTION MECHANISM IN Na_(5+x)YA1_xSi_(4-x)O_(12) SUPERIONIC CONDUCTORS

Na5+xYAlxSi4-xO12 superionic conductors arerhombohedral R3c space group.Their structures arecharacterized by(Alx/4Si1-x/4)O4 tetrahedra linked toform puckered(Al3xSi4-x)4O35 rings parallel to thebasal plane of the hexagonal cell.These rings,separated by parts of sodium oxygen polyhedron,arestacked to form large rigid colums parallel to c axis.The columns are linked by[YO6]octahedra to form athree-dimensional Framework with large channels betweenthe rings.Parts of Na ions located in the cores of thecolumns are movable.In terms of the conductionmechanism,the concentration of conducting Na+ ions wascarried out and compared with the experimental results.It was found that the theoretical values accord withthe experimental results.

Externalized conductors and insulation failure in Biotronik defibrillator leads: History repeating or a false alarm?

Conductor externalization and insulation failure are frequent complications with the recalled St. Jude Medical Riata implantable cardioverter-defibrillator(ICD) leads. Conductor externalization is a "unique" failure mechanism: Cables externalize through the insulation("inside-out" abrasion) and appear outside the lead body. Recently, single reports described a similar failure also for Biotronik leads. Moreover, some studies reported a high rate of electrical dysfunction(not only insulation failure) with Biotronik Linox leads and a reduced survival rate in comparison with the competitors. In this paper we describe the case of a patient with a Biotronik Kentrox ICD lead presenting with signs of insulation failure and conductor externalization at fluoroscopy. Due to the high risk of extraction we decided to implant a new lead, abandoning the damaged one; lead reimplant was uneventful. Subsequently, we review currently available literature about Biotronik Kentrox and Linox ICD lead failure and in particular externalized conductors. Some single-center studies and a nonprospective registry reported a survival rate between 88% and 91% at 5 years for Linox leads, significantly worse than that of other manufacturers. However, the preliminary results of two ongoing multicenter, prospective registries(GALAXY and CELESTIAL) showed 96% survival rate at 5 years after implant, well within industry standards. Ongoing data collection is needed to confirm longer-term performance of this family of ICD leads.

Algebraic Current-voltage and Voltage Dependent Resistance Expressions for Ballistic Nano Conductors and Their Low Voltage Nonlinearity

In this study, an algebraic current-voltage(I-V) equation suitable for the hand-calculation of ballistic nano conductors is derived from Landauer's formulation. A voltage and temperature dependent resistance expression is also obtained. It is shown that the presented algebraic I-V expression and the original Landauer's formula give the same characteristics as expected. Moreover, the I-V characteristics of ballistic nano conductors are investigated and it is concluded that there is an inescapable nonlinearity originating from the curvature of Fermi-Dirac distribution function in low voltage range. Finally, the total harmonic distortion(THD) of a sample ballistic nano conductor caused from its low voltage nonlinearity is computed via HSPICE simulations.

Analyzing an UWB Bandpass Filter for High Power Applications Using Rectangular Coaxial Cables with Square Inner Conductors

Using the finite element method (FEM) in two dimensions and the CST MICROWAVE STUDIO? (CST MWS) Transient Solver, the electromagnetic (EM) analysis and the design of a novel compact ultra wideband (UWB) bandpass filter using rectangular coaxial cables with square inner conductors, convenient for high power applications, are presented. The design of the UWB BP filter is based on the use of impedance steps and coupled-line sections. The center frequency around 6.85 GHz was selected, the bandwidth is between 3-10 GHz, the insertion-loss amounts to around 0.35 dB and the return loss is found higher than 10 dB in a large frequency range (4-9.5) GHz. The simulated results of stopband performances are better than 15 dB for a frequency range up to 11 GHz. For the selected center frequency and on a substrate with a dielectric constant of 2.03, the rectangular coaxial cables BPF with square inner conductors is only 6.7 × 8.9 × 33.4 mm in size.

Preparation of a Cube-Textured Ni-7at.%W Based Template Used for Coated Conductors

Although Ni-W substrate with high W content (>5at.%) substrates have been developed successfully, the quality of cube texture and grain boundary, as well as extensive applications in coated conductors should be further improved. In the present work, once intermediate annealing treatment (IAT) at 500°C for 2 h has been employed to optimize the deformation and recrystallization textures in Ni-7at.%W (Ni7W) substrates. As a result, competitive high cube texture content (<10°) and low angle grain boundary fraction (<10°) were realized (98.5% and 91.2%, respectively). A Gd2Zr2O7 (GZO) buffer layer with strong cube texture and high-quality surface deposited successfully on the Ni7W substrate using the chemical solution deposition method, demonstrating the advanced GZO/Ni7W template is promising for coated conductors.

Effects of Sc doping on electrical conductivity of BaZrO_3 protonic conductors

BaZr1-xScxO3-0.5x (x=0.07,0.10,0.13,0.16) powders were prepared by solid-state reaction method,and ZnO was used as sintering aid.Samples with different amount of ZnO additive were sintered at 1450·C for 6 h in air.Single cubic perovskite phase proton conductors were obtained.Conductivity was measured by electrochemical workstation.It was shown that Sc doping could increase conductivity through enhancing the carrier concentration in the material,but excessive Sc content might decrease the carrier concentration because of its charge compensation.ZnO had an influence on carrier concentration and mobility and affected the electrical conductivity.2 mol% ZnO and 13 mol% ScO1.5 doped sample showed the highest DC conductivity of 3.6×10-3 S·cm-1 tested at 800·C in wet hydrogen atmosphere.

Fabrication of NiO Buffer Layer for YBCO Coated Conductors by Combining Sputtering and SOE Method

In research of YBCO coated conductors, the development of a oxide template for epitaxial growth of YBCO is very important. Matsumoto et al have demonstrated the potential of the surface oxidation epitaxial (SOE) route for formation a cube textured NiO layer on nickel tapes. The epitaxial NiO functions as a buffer layer of chemical reaction between YBCO and nickel, and as a template for the epitaxial growth of YBCO. However, the surface quality of NiO is difficult to control and defects such as crack, spall and deep grooves exist in SOE NiO layer. A new approach combining sputtering and SOE method to obtain crack-free and cube textured NiO layer were reported. Ni tapes prepared by the combination of rolling and recrystallization were used for this work. A coating of Ni was first deposited on the tapes via magnetron sputtering. Then on the coating tapes, continuous and textured NiO layer were achieved by SOE technology.

Two-dimensional equations for thin-films of ionic conductors

A theoretical model is developed for predicting both conduction and diffusion in thin-film ionic conductors or cables. With the linearized Poisson-Nernst-Planck(PNP)theory, the two-dimensional(2D) equations for thin ionic conductor films are obtained from the three-dimensional(3D) equations by power series expansions in the film thickness coordinate, retaining the lower-order equations. The thin-film equations for ionic conductors are combined with similar equations for one thin dielectric film to derive the 2D equations of thin sandwich films composed of a dielectric layer and two ionic conductor layers. A sandwich film in the literature, as an ionic cable, is analyzed as an example of the equations obtained in this paper. The numerical results show the effect of diffusion in addition to the conduction treated in the literature. The obtained theoretical model including both conduction and diffusion phenomena can be used to investigate the performance of ionic-conductor devices with any frequency.

Studies on a New System of Lithium Fast Ion Conductors Based on Kaolinite and LiZr_2(PO_4)_3

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EFFECTS OF DISPERSED SECOND-PHASE PARTICLES ON MIXED CONDUCTORS OF Li_(1+x)V_3O_8(X=0, 1)

The structure and electric properties of the mixed conductors of Li1+xV3O8（x=0.1） containing dispersed second-phase α-Al2O3 particles have been studied in the paper. The total conductivity of the specimen containing 6m/o α-Al2O3 is five or six times as much as that of pure Li1+xV3O8 （x=0.1） at room temperature. By the analyses of NMR and ESR, it is known that at low temperature, the transport activation energy of Li+ ions reduced, the transport frequency of Li+ ions are speeded up and thus ionic conductivity increased in the specimens containing α-Al2O3 particles. At high temperature, diffusion effect of α-Al2O3 on electronic transport becomes great, the enhancement of ionic conductivity caused by α-Al2O3 doesn’t make up the decrease of electronic conductivity caused by the diffusion effect, so that total conductivity of the specimens containing DSPP is lower than that of pure Li1+xV3O8（x=0.1）. As a result, DSPP mainly increases ionic conductivity of the mixed conductors at room temperature.

Epitaxial Bi_(2)Sr_(2)CuO_(y) thin films as p-type transparent conductors

Development of p-type transparent conducting thin films is tireless due to the trade-off issue between optical transparency and conductivity. The rarely concerned low normal state resistance makes Bi-based superconducting cuprates the potential hole-type transparent conductors, which have been realized in Bi_(2)Sr_(2)CaCu_(2)O_(y) thin films. In this study, epitaxial superconducting Bi_(2)Sr_(2)CuO_(y) and Bi_(2)Sr_(1.8)Nd_(0.2)CuO_(y) thin films with superior normal state conductivity are proposed as ptype transparent conductors. It is found that the Bi_(2)Sr_(1.8)Nd_(0.2)CuO_(y) thin film with thickness 15 nm shows an average visible transmittance of 65% and room-temperature sheet resistance of 650 Ω/sq. The results further demonstrate that Bi-based cuprate superconductors can be regarded as potential p-type transparent conductors for future optoelectronic applications.

Vertically aligned nanocomposite films by self-assembled epitaxial nucleation for super-broadband transparent conductors

Designing super-broadband transparent conductors is challenging because of the exclusive nature of conductivity and infrared transmittance.Here,using a one-step process,we created vertically aligned nanocomposite conducting films with high transparency across a super-broad wavelength range.Vertically aligned transparent Ba_(3)V_(2)O_(8)nanocolumns with lateral-100-nm widths enable high transmittance(>50%,even at a 4-μm wavelength)for all incident light and outperform that of Sn-doped In_(2)O_(3),while the conducting SrVO_(3)matrix retains low resistivity(<0.56 mΩcm at room temperature).A combined study of scanning transmission electron microscopy,scattering scanning nearfield infrared microscopy,and X-ray diffraction revealed that spontaneous phase separation of Ba_(3)V_(2)O_(8)nanocolumns in a SrVO_(3)matrix film occurs via self-assembled epitaxial nucleation.Our vertically aligned nanocomposite films provide a fertile platform for next-generation optoelectronics.

Bioinspired Strategies for Stretchable Conductors

Stretchable conductors are indispensable components of stretchable electronic devices,such as stretchable sensors,transistors,light-emitting diode arrays,solar cells,and so on.However,most of the conductive materials are stiff with very low stretchability.Nature has evolved various strategies to realize stretchability,which give a lot of inspirations to the design and fabrication of stretchable conductors.We herein summarized the nature’s strategies to realize stretchability and revealed the underlying mechanisms.After that,the applications of these strategies in fabricating stretchable conductors are exemplified and the effects of some important parameters on the performances are discussed.Then,possible applications of these stretchable conductors are summarized.Finally,critical issues in the stretchable conductors are discussed and several prospective exploration directions are provided.

An end-to-end artificial intelligence platform enables real-time assessment of superionic conductors

Superionic conductors(SCs)exhibiting low ion migration activation energy(Ea)are critical to the performance of electrochemical energy storage devices such as solid-state batteries and fuel cells.However,it is challenging to obtain Ea experimentally and theoretically,and the artificial intelligence(AI)method is expected to bring a breakthrough in predicting Ea.Here,we proposed an AI platform(named AI-IMAE)to predict the Ea of cation and anion conductors,including Li^(+),Na^(+),Ag^(+),Al^(3+),Mg^(2+),Zn^(2+),Cu^((2)+),F^(−),and O^(2−),which is~105 times faster than traditional methods.The proposed AI-IMAE is based on crystal graph neural network models and achieves a holistic average absolute error of 0.19 eV,a median absolute error of 0.09 eV,and a Pearson coefficient of 0.92.Using AI-IMAE,we rapidly discovered 316 promising SCs as solid-state electrolytes and 129 SCs as cathode materials from 144,595 inorganic compounds.AI-IMAE is expected to completely solve the challenge of time-consuming Ea prediction and blaze a new trail for large-scale studies of SCs with excellent performance.As more experimental and high-precision theoretical data become available,AI-IMAE can train custom models and transfer the existing models to new models through transfer learning to constantly meet more demands.

Electrifying Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ) for focalized heating in oxygen transport membranes

Industry decarbonization requires the development of highly efficient and flexible technologies relying on renewable energy resources,especially biomass and solar/wind electricity.In the case of pure oxygen production,oxygen transport membranes(OTMs)appear as an alternative technology for the cryogenic distillation of air,the industrially-established process of producing oxygen.Moreover,OTMs could provide oxygen from different sources(air,water,CO_(2),etc.),and they are more flexible in adapting to current processes,producing oxygen at 700^(-1)000℃.Furthermore,OTMs can be integrated into catalytic membrane reactors,providing new pathways for different processes.The first part of this study was focused on electrification on a traditional OTM material(Ba_(0.5)Sr_(0.5)Co_(0.8)Fe_(0.2)O_(3-δ)),imposing different electric currents/voltages along a capillary membrane.Thanks to the emerging Joule effect,the membrane-surface temperature and the associated O_(2) permeation flux could be adjusted.Here,the OTM is electrically and locally heated and reaches 900℃on the surface,whereas the surrounding of the membrane was maintained at 650℃.The O_(2)permeation flux reached for the electrified membranes was~3.7 NmL min^(-1)cm^(-2),corresponding to the flux obtained with an OTM non-electrified at 900℃.The influence of depositing a porous Ce_(0.8)Tb_(0.2)O_(2-δ) catalytic/protective layer on the outer membrane surface revealed that lower surface temperatures(830℃)were detected at the same imposed electric power.Finally,the electrification concept was demonstrated in a catalytic membrane reactor(CMR)where the oxidative dehydrogenation of ethane(ODHE)was carried out.ODHE reaction is very sensitive to temperature,and here,we demonstrate an improvement of the ethylene yield by reaching moderate temperatures in the reaction chamber while the O_(2) injection into the reaction can be easily fine-tuned.

Preparation of YBCO Coated Conductors on RABiTS Substrate with Advanced TFA-MOD Method

YBCO high temperature coated conductors are the most promising candidate for large scale superconducting transmission cables and fault current limiters. A modified TFA-MOD method was applied to prepare YBCO layer on Rolling Assisted Biaxially Textured Substrate (RABiTS) with textured Y 2 O 3 /YSZ/CeO 2 buffer layers, resulting in reduced time and cost of fabrication. By using Cu naphthenate instead of Cu(TFA) 2 , the pyrolysis time of the YBCO precursors was reduced significantly. YBCO films with thickness of 2 μm were fabricated with multiple-coating and annealed at high temperature for 2 h. X-ray diffraction analysis revealed that the films were c-axis oriented. The preliminary results of YBCO films yielded 0.2 MA/cm 2 at 77 K and self field. It is believed current carrying ability of YBCO films could be further improved by reducing the reaction rate at the interface between the buffer layer and superconducting layer.