Thin Tape Research Articles

Internal Oxidation of Textured Thin Tapes of Binary Copper-Based Alloys

Transmission electron microscopy was used to perform a structural analysis of a number of binary copper alloys with 3d transition elements after short-term annealing in an oxidative atmosphere (5 and 30 min) at a temperature of 700°C. It has been established that the textured tapes of Cu–Cr and Cu–Fe alloys sustain not only surface oxidation in the process of additional annealing, but also internal oxidation. Electron diffraction analysis has shown that a layer of complex spinel-type CuМ2O4 oxide (М = Cr, Fe) forms on alloying element particles under annealing, while the precipitation of dispersed copper oxides, predominantly, Cu2O with a small admixture of CuO occurs in the copper matrix. Microhardness analysis has demonstrated that internal oxidation in the tapes of the studied binary alloys does not have an adverse effect on their mechanical properties.

Fabrication of hybrid thin ply tapes

Thin ply hybrids are composed of at least three different materials: two or more yarns and one binder to fix the final thin ply tape. This study is divided in the steps required to convert the raw materials (carbon, glass, aramid and polyester) into the hybrid thin ply tapes: unwinding of the yarn; spreading of each individual yarn; hybridization, blending and spreading of all the materials, and finally binding and winding the final thin ply hybrid. All these processes are studied individually to determine the effect of each one on different yarns. The more important steps on this hybrid spreading line are the spreading methods and the blending of different materials. Different processes such as ultrasounds, mechanical vibration, convex rollers, air flow, etc, exist to spread the yarns. The choice of this study is to use mechanical vibrations in the individual yarns whereas the second step is performed with vacuum, paying attention to the control of the tension during the entire process. The developed technique allows for production rates from 5 to 20 m/min of hybrid fiber depending on the characteristics of the raw material, showing that the fabrication process of these materials is suitable for industry.

Laser-Induced Superelasticity in NiTinol Stent Strut

Shape setting is a fundamental step of NiTi components manufacturing. It is undertaken for fixing programmed shapes and for optimizing both the shape memory and the superelastic properties of SMA. Conventional NiTinol shape setting is performed by constraining the material in furnace where it is heat treated completely, and thus local component functionalization is not allowed. Recently, it has been demonstrated the feasibility of fast laser shape setting of straight thin NiTinol wires to induce a superelastic behavior comparable to the commercial wires. This work reports the use of a laser beam for promoting a local superelasticity in a NiTi diamond-like strut. In details, the struts were cut from a cold worked NiTi thin tape, and then a focused laser heating was implemented just on the parts of the element in which the superelasticity is strictly required. Thermo-mechanical testing of the struts, after local laser process conditions, indicates that a laser beam scanning is suitable for provoking local microstructure modifications, which enables the superelastic functioning of the strut-like element. Scanning electron microscopy has shown that residual martensite variants, present in the cold worked material, disappear in the portion of the diamond elements where the laser beam passed.

Thermal Conductivity and Dilatation of Bi-2223/Ag (DI-BSCCO) Superconducting Wire Laminated With Various Thin Alloy Tapes

A Bi-2223/Ag wire laminated with Ni-alloy tapes offered the high critical tensile strength over 400 MPa with a high critical current of about 200 A, which has just started to be equipped in high-field facilities. To design such a practical superconducting apparatus, we must know the heat leakage through the wires and the elasticity among the constitutional materials. In this paper, we report on the thermal conductivity and dilatation of this new Bi-2223/Ag/Ni-alloy tape, compared to those of other Bi-2223/Ag tapes, and discuss the contribution of the lamination alloy to the thermal properties.

S76. Effectiveness of Kinesio tape on wrist extensor muscles in children with obstetric brachial plexus injuries

Introduction Obstetric brachial plexus injury (OBPI) is partial or total paralysis of the upper limb due to trauma of brachial plexus during delivery, wrist flexion is a common deformity that develops in children with Erb’s Palsy. Kinesio tape (KT) is thin and elastic tape that can be extended up to 120–140% of its original length, this elasticity result in less constraints. KT allows a partial to full range of motion for the applied muscles and joints with different pulling forces to skin, it can be used for both muscle relaxation and to facilitate muscle contraction depending on its. The purpose of the study was to assess the effect of Kinesio tape in stimulation of the extensor muscle wrist contraction in children with Erb’s palsy. Methods This is a hospital-based controlled study conducted in Al-taher marzouq clinic at Khartoum, Sudan in 2015. Thirty children with Erb’s palsy were involved, their age ranged from one month to three years. They were divided into two matched groups (control and study) 15 children each. They evaluated by Active movement scale and Gilbert-Raimondi classification before and after fifteen successive sessions of the treatment program. Control group received selected physical therapy program included the following: Neuromuscular stimulation, for wrist extension for 20 min. Facilitation of muscle contraction for all weak muscle of upper limb. Exceoreceptor such as brushing, brief ice scratch. Proproceptor such as taping, approximation, quick stretch (Strengthen Exercise). Very gentle stretch for subscapularis, prontator and wrist flexor. Graduated active exercise (active assist, active free, active resist). Facilitate of basic hand skill (reaching, grasping, released, bilateral hand use). Weight bearing exercise from prone on hand, side sitting and quadruped positions. While and study group received Kinesio tape in addition to the program given to control group. Results The results of this study revealed statistically significant improvement in both group while the favor improvement in wrist extensor muscles in children with Erb’s palsy in study group (Active movement scale p = 0.006) (Gilbert Raimondi classification p = 0.02). Conclusion Using the Kinesio tape in addition to selected physical therapy program is beneficial therapeutic technique to improve active wrist extension and functional activities in children with Erb’s palsy.

Joining of SiC monoliths using a thin MAX phase tape and the elimination of joining layer by solid-state diffusion

This paper reports the joining of SiC monoliths using a thin MAX phase tape filler, such as Ti3AlC2 and Ti3SiC2, and the subsequent phenomena leading to the elimination of the joining layer via solid-state diffusion of the MAX phase into the SiC base material, particularly with the decomposition of the Ti3AlC2 filler. The base SiC monolith, showing ≥ 99% density, was fabricated by hot pressing SiC powder after adding 5 wt. % Al2O3-Y2O3 sintering additive. A butt-joint configuration was prepared and joined by hot pressing under a pressure of 3.5 MPa. The effects of the experimental parameters, including the type and thickness of the joining filler, temperature as well as the holding time, were examined carefully in terms of the microstructure, phase evolution and joining strength. The joining interface could be eliminated from the SiC base when the SiC monoliths were joined at 1900 °C using a thin Ti3AlC2 tape, showing a high joining strength ∼300 MPa. Moreover, fracture during the mechanical test occurred mainly at the base material rather than the joining interface, indicating excellent joining properties. These findings highlight the elimination of the joining interlayer, which might be ideal for practical applications because the absence of a joining filler helped preserve the excellent SiC mechanical properties of the joint.

Development of ReBCO-CORC Wires With Current Densities of 400–600 A/mm $^2$ at 10 T and 4.2 K

Thin ReBCO tapes of 2 mm in width and only 30- $\mu$ m substrate thickness allow production of thin CORC wires of 3–4 mm in diameter. These CORC wires feature high bending flexibility and high current densities as required for high field magnets. Two CORC wires, the first with 50 tapes and the second with 29 tapes, were developed and tested in a common effort of CERN, ACT, and the University of Twente. The two CORC wires were tested as small solenoids in transverse magnetic fields of up to 10.5 T and at 4.2 K. Afterwards, single tapes were extracted from the samples and tested individually in self field at 76 K. The first CORC wire had a critical current of 4255 A and an engineering current density of 322 A/mm $^2$ , while the second wire showed 3970 A and 412 A/mm $^2$ , both at 10 T and 4.2 K. The extracted tape analyses showed points of improvement for both wires, and therefore, provide valuable feedback for improving the wire production process and wire handling. CORC wire optimization resulted in no performance degradation of the 29-tape wire during electromagnetic load cycling at high magnetic fields. In this paper, details are presented on the CORC wires and measurement results are summarized.

A Study of the Magnetoelastic Effect of Metal Textured Ni–5 at % W Tapes

In the temperature range of 50–360 K, the effect of the plane mechanical deformations on the magnetic susceptibility χac(T) of metal biaxially textured Ni–5.0 at % W tapes has been investigated. To create the state of plane stress, the temperature cycling of thin tapes cemented to thick substrates of Si, Mo, Ti, and D16T aluminum alloy has been performed. It has been shown that the main features of the magnetic susceptibility behavior can be explained by magnetoorientation transitions and the appearance of internal stresses σ(T) exceeding the yield strength of the tape material.

A plasma device for increasing the hydrophilicity of paper products

The treatment of various materials using low-temperature gas–discharge plasma to clean their surface or change their structure is rather promising because of the generation of particles that react with molecules of impurities or base material. In addition, the molecules of the surface layer of material are exposed to the influence of ultraviolet and soft X-ray radiation generated in the cathode layer of the discharge. Only the volumetric gas–discharge can guarantee a high degree of uniformity of the material surface treatment. To increase the intensity of the plasma-chemical reactions, it is effective to increase the frequency of the supplied voltage of a discharge reactor or to use the pulse–periodic power-supply mode. The pulse frequency should be coordinated with the typical frequency of the plasma chemical reactions. Experimental installations that have a discharge reactor as their main element showed successful performance for the modification of the volumetric structure of a thin paper tape to increase its hydrophilicity.

Effects of Steel Tapes on Internal Pressure in Mass Impregnated HVDC Cables

Thin steel tapes providing radial mechanical support is a vital component in mass impregnated non-draining (MIND) HVDC cables. When the insulation volume increases with temperature during operation, the tapes work against the expansion and make sure that the cable is not permanently deformed by repeated heat cycles. It is belived that the application of steel tapes also compresses the insulation, increasing the internal pressure building up when the cable is loaded. The oil impregnant has a much higher thermal expansion coefficient than the paper, which can cause both radial flow of oil when heating and cavity formation - and thereby the risk of dielectric breakdown - when cooling. Steel tapes are important in this regard, as they may enhance there effects by reducing the insulation volume. Through measurements of internal pressure and thermal expansion as function of temperature, this work confirms that there is a significant difference in pressure behaviour in cables with the steel tapes in place and when they are removed. Measured pressures ange from some 0.3 bar belom atmospheric at 20 °C, to approximately 8 bar at 46 °C. The experimental results are compared to available literature, and a new mathematical model that calculates the pressure at the insulation/sheat interface.

Contact Mechanics of a Thin, Tensioned, Translating Tape With a Grooved Roller

Traction between a thin tensioned tape and a grooved roller could be significantly affected by lubrication effects that stem from the air entrainment into the tape–roller interface. An experimental and theoretical investigation was carried out to investigate the tape contact with a grooved roller. The tape-to-roller spacing was measured in a modified tape drive at various operational speed and tension values. The experiments showed that increasing tape tension and tape speed causes the tape-to-land spacing to increase. This unusual result is shown to be due to the tape bending laterally into the grooves. The effects of air entrainment on tape deflection and contact with a land is modeled by using shell theory, air lubrication, and contact mechanics. A relatively wide range of design parameters (groove width, land width) and device parameters (velocity and tension) were simulated to characterize the traction of a thin tape over a grooved roller. It was shown that air lubrication effects reduce the contact force; however, the underlying effects of tape mechanics are not entirely eliminated. This work shows that in order to characterize the mechanics of thin tape over grooved rollers, the tape deflection in the lateral direction should be included in the analysis.

Non-uniform ramping losses and thermal optimization with turn-to-turn resistivity grading in a (RE)Ba2Cu3Ox magnet consisting of multiple no-insulation pancake coils

This paper presents a study on the ramping losses of a high temperature superconductor (HTS) magnet consisting of multiple no-insulation (NI) (RE)Ba2Cu3Ox coils. The (RE)Ba2Cu3Ox (REBCO) conductor is the second generation HTS thin tape, where RE stands for rare-earth. During a ramping operation of the NI HTS magnet, losses are generated both across turn-to-turn resistances and inside superconducting layers. The former comes with radial current, which is called “turn-to-turn loss;” the latter one is induced by flux creep and jump, called “magnetization loss.” The modeling and experimental studies on the ramping losses have been reported on single NI pancake coils in the previous part. In a HTS magnet consisting of multiple NI coils, the electromagnetic coupling between coils has a considerable influence on the distribution of ramping losses. Here, the experimentally validated model is used to investigate a HTS magnet consisting of 14 single pancake REBCO coils. The results show that both the turn-to-turn loss and the magnetization loss present a significant non-uniform distribution among the coils. The highest turn-to-turn loss occurs on the middle coils of the magnet, while the highest magnetization loss happens on the end coils. The non-uniform distribution of ramping losses can result in a considerable temperature difference among coils in the NI HTS magnet. It leads to an additional quench risk on the magnet and requires more attention in design. The distribution of the turn-to-to-turn loss can be optimized by adjusting the turn-to-turn resistivity. A much more uniform turn-to-turn loss distribution among coils is achieved by applying a graded turn-to-turn resistivity on the multiple coils.

Kinesio taping does not alter muscle torque, muscle activity or jumping performance in professional soccer players: A randomized, placebo-controlled, blind, clinical trial.

Kinesio taping consists of the attachment of a thin elastic tape over specific muscles, the thickness of which is similar to that of the epidermis. The aim of the present study was to compare the effect of Kinesio taping and placebo taping on muscle torque, muscle activity and jumping performance soccer players. Thirty athletes were randomly allocated to two groups (Group A: Kinesio taping and Group B: placebo taping). The participants were instructed to perform the Hop test's and were submitted to an isokinetic evaluation of the knee extensors as well as an electromyographic evaluation of the retus femoris muscle of the dominant lower limb. Next, Kinesio taping was performed for the activation of the rectus femoris muscle in Group A and placebo taping was performed in Group B. The participants were reevaluated 30 minutes after taping and 24 hours after the first evaluation using the same tests. Intra-group and inter-group comparisons were made considering the three evaluation times. No statistically significant differences were found between groups at any evaluation time regarding the Hop test's, root mean square of the electromyographic signal or peak torque of the knee extensors of the dominant lower limb (p>0.05). Kinesio taping for the activation of the rectus femoris muscle has no effect on peak muscle torque, muscle activity or jumping performance among soccer players.

Novel hybrid composite discharge electrode for electrostatic precipitator

ABSTRACTOver the last few decades, electrostatic precipitators (ESPs) have emerged as effective air pollution control devices for treating coal-fired power plant exhausts. Among the components of the ESP, the discharge electrodes are extremely important in determining the collection efficiency of the ESP. Typically, in wet ESPs, the discharge electrodes used must be made of corrosion-resistant alloys, which makes them extremely expensive and heavy. Hybrid composite discharge electrodes have the potential to be lightweight and corrosion-resistant substitute for traditional metal alloy electrodes used in wet ESPs. In this experimental study, a novel hybrid composite electrode (recently patented at Ohio University) is presented as a substitute for traditional metal electrodes in wet ESPs. The samples of hybrid electrodes were fabricated by using carbon fiber composites, combined with metal mesh, in the shape of a long and thin tape. The electrode’s electrical response was evaluated in open atmospheric conditions, while connected to a transformer-rectifier unit to generate a corona current at voltages exceeding 50 kV. Results of these hybrid electrodes were compared with traditional metal electrodes. The hybrid composite discharge electrode produced a uniform corona at comparable power levels to that of metal electrodes, with additional advantages of being compact, lightweight, and highly corrosion resistant. In addition, hybrid composite electrodes exhibited lower corona onset voltage as compared with metal electrodes. The preliminary experimental data are encouraging and show significant potential for this new inexpensive hybrid electrode to replace metal electrodes in wet ESPs, providing comparable (and in some cases exceeding) collection efficiencies with lower ozone generation.Implications: The newly invented hybrid composite electrode (HCE) performance was evaluated through experimentation with conventional metal electrodes. The HCE performance was comparable to the metal electrodes. The HCE also exhibited uniform corona fields and steady power while maintaining similar and in some cases superior electrical performance as compared with metal electrodes and thus shows a significant potential to substitute metal electrodes in wet ESP systems.

On Obtaining sharp cubic texture in thin tapes made of binary alloys of copper with yttrium and titanium

This article is devoted to the study of texturizing in tapes of binary alloys Cu–1 wt % Y and Cu–1.27 wt % Ti upon cold deformation by rolling with the degree of ~99% and subsequent recrystallization annealing. The possibility of achievement of perfect cubic texture in thin tape of binary alloy on the basis of copper with addition of yttrium is demonstrated in principle; this enables their usage as substrates for epitaxial application of functional layers, including production of high temperature ribbon cables of the second generation. Optimum annealing modes are determined that enable achievement of perfect biaxial texture with the content of cubic grains {001} 〈100〉 ± 10° more than 95% on the texturized tape surface in Cu–1 wt % Y alloy. Alloying of copper with titanium leads to significant variation of component composition of cold rolling texture. Transition from texture deformation of copper type to texture deformation of α brass type makes it impossible to achieve recrystallization cubic texture in Cu–1.27 wt % Ti upon subsequent annealing.

Ultra-Small Diameter Round REBCO Wire With Robust Mechanical Properties

The compressive bend diameter (REBa 2 Cu 3 O x (REBCO) layer facing inward in all cases) dependence of critical current (Ic) of commercial (stabilizer free, 50-μm substrate) and thin (22-μm substrate) REBCO tapes has been compared after copper electroplating only on REBCO side and on both sides of the tape. We have experimented with different substrate and stabilizer thickness of the REBCO tape to maximize high I c retention while the tape is bent into smaller diameter forms. Single-layer round wires made by winding the most robust REBCO tapes on 0.81-mm copper former have been tested for its critical current at different twist pitches under combined torsion and compressive strains. Using the best tape, the critical current of a multilayer round wire of 1.6-mm overall diameter (0.81-mm core) has been tested under bending over a range of diameters from 12 to 3 cm. These studies confirm the superior retention of critical current under combined effect of high torsion and compressive bend strain of our ultra-small diameter REBCO wires.

Experimental Investigation of Complex Bending-Effect on Superconducting Characteristic of YBCO Tape Applied to Force-Balanced-Coil for Superconducting Magnetic Energy Storage Device

In order to minimize the weight of support structures for superconducting magnetic energy storage with relatively large storage capacity, the coil for the storage device is designed based on the virial limit, in which the hoop stress is well optimized but flatwise (FW) and edgewise (EW) bending strains would be applied when we use YBCO thin tape to construct the coil. The complex bending strains supposed to be applied to the tape are experimentally investigated by using newly developed complex bending testing device and sets of strain gauges. Even in the range of the presumed bending radius and tensile stress for the coil winding, several combinations of FW, EW bending, and tensile stress cause specific deterioration of superconducting characteristics. The Rosette analysis by using tri-axial strain gauge revealed that the extremely high shear strain would be in relation to the deterioration. This work will help developing a winding technique without any degradation of superconducting characteristics such as critical current and n value of the fragile material.

Porous Cu/YSZ anodes processed by aqueous tape casting for IT-SOFC

Porous copper/yttria-stabilized zirconia (Cu/YSZ) thin tapes were produced to be used as anodes in intermediate temperature solid oxide fuel cells (IT-SOFC). The use of copper in these cermets promises a better chemical resistance and a lower operating temperature for SOFC. Graphite and cassava starch were used as pore forming agents, which led to porosity values between 30 and 40%. Tapes were obtained by aqueous tape casting with controlled thickness (300–2000μm). Before casting, CuO/YSZ aqueous suspensions were formulated based on rheological characterization. Sintering was carried out at 1150°C during 1h. Cu/YSZ tapes were obtained after redox reaction, performed at 400, 600 and 800°C.

Scaling law for voltage–current curve of a superconductor tape with a power-law dependence of electric field on a magnetic-field-dependent sheet current density

Systematic theoretical study on the voltage (V) vs. current (I) curves of high-Tc superconductor (HTS) thin tapes has not been done till now, although their measurements are frequently used for determining critical current Ic at electric field E≡V/lv=Ec=10−4 V/m, lv being the voltage tap distance. On the other hand, it is well recognized that such tapes obey a power-law dependence of local electric field on local sheet current density with a Kim-model critical sheet current density, from which the V vs. I curve may be calculated as a function of current ramp rate R. Such calculations are carried out in the present work with a scaling law deduced, which states that if E/Ec vs. I/Ic is a solution at given apparent power-law exponent na and R/Ec, then this R/Ec multiplied by a constant C leads to another solution with E/Ec and I/Ic multiplied by C and C1/na, respectively. In the help of the scaling law, condition-dependent V vs. I may be studied systematically and completely based on a limited amount of numerical computations and V−I curve measurements may be performed under properly controlled conditions to become a more powerful tool for HTS research.

Hydrodynamics and heat and mass transfer during formation of thin metal glass tape

The mathematical model of hydrodynamic and heat transfer processes in a system, which rotates a disk, a metal tape, an environment, is developed. The adequacy of both the mathematical model and the computing algorithm is confirmed by comparison the computing results with the laboratory experiment. It has been shown that increase of the disc’s rotational speed reduces the thickness of the amorphous metal tape.