Steel Tape Research Articles

Long HTS Coated Conductor Processed via Large-Area PLD/ABAD for High-Field Applications

Progress in the upscaling of multibeam pulsed laser deposition (PLD) is reported. Tapes 220 m long were repeatedly processed using an extended drum in PLD installation employed for the deposition of ceria cap buffer and YBCO layers. A Cr-Ni stainless steel tape preliminary coated with a biaxially textured yttria-stabilized-zirconia buffer layer via alternating-beam-assisted deposition was used as a substrate. In 2014, the upscaling of the PLD technique was performed in three steps. In the first step, a 22-m-long tape with record “in-field” critical current (500 A in a 4-mm-wide tape at 4.2 K, 18 T, B//c) was achieved in February 2014. The second step enabled the deposition of 110-130-m-long tapes with moderate (20%) reduction of critical current and sufficiently small local dropouts of the current. The third step resulted in the upscaling of tape processing to 230 m in length. First tapes of such length were already obtained in December 2014. Further upscale of the tape length toward 600 m and more is in progress so far. The most important feature of the PLD process is that the critical current in the coated conductors demonstrates no reduction in the end of the tape, which was exposed to a single run of translation of the rotating drum with the tape, i.e., from one end to the other end. Moreover, in many cases, a tendency of increase of critical current was observed during deposition run. Pulses of oxygen pressure formed by the deposition system together with the influence of barium zirconate precipitations enabled rather high in-field critical currents in 230-m-long tapes.

Mapping the degree of damage to houses of Paifang village, Anhui, China, caused by underground coal extraction

Subsidence due to underground coal mining caused considerable damage to the houses of Paifang village. In this work, damage levels (A-D according to Chinese National Guidelines) were determined by measuring the magnitude of cracks with a steel tape. Buildings were subdivided by structure, quality and location; differentiated structures included one-storey, one-storey with footing beams, and two-storey with footing beams. Results indicate that the damage levels of houses are closely related to the structures and the location in respect to the extracted area. Poor quality houses were more easily damaged than well-built ones; two-storey houses were more unstable than one-storey; and the houses near the boundary of the extracted area suffered larger distensional strain, and were more heavily damaged. The findings will be useful to house maintenance and to reinforcing newly built houses.

Experimental analysis on AC loss and fault current test of HTS coils co-wound with various inserted materials

A significant number of recent studies have explored the impact of many kinds of winding insulation conditions on high-temperature superconducting (HTS) coils for the application of electric devices. HTS coil co-wound with turn-to-turn inserted materials could be an appropriate alternative to the no-insulation coil because of the poor charge–discharge delay and unexpected quench behavior of the no-insulation coil. In addition, the co-wound HTS coil has good thermal stability and mechanical integrity, making it useful for superconducting applications such as superconducting magnetic energy storage (SMES) and superconducting fault current limiter (SFCL). However, studies of the co-wound HTS coil have explored dc electrical characteristics, but not ac electrical characteristics. Research into ac electrical characteristics is essential because of the operation sequence of the SMES and fault occurrence for the SFCL. In this paper, the ac electrical characteristics of HTS coils co-wound with various inserted materials were experimentally analyzed. Tested coils were co-wound with either Kapton, stainless steel, or copper tape at every turn of the winding, and one no-insulation coil served as a reference. AC loss, fault current, and recovery time were measured at 77 K, self-field.

Stability and quench behaviors of conduction-cooled 2G HTS coil co-wound with SS tape

We fabricated a second-generation (2G) high-temperature superconducting (HTS) model coil cowound by a 2G HTS tape and a stainless steel (SS) tape. The inner diameter of the model coil was 120 mm, and the number of turns was 100. A 2G HTS tape 12 mm in width manufactured by SuNAM Co., Ltd. in South Korea was used. The total length of the coil was 44 m, and the critical current $(I_{{c}})$ of the model coil was about 174 A in liquid nitrogen. The minimum quench energy (MQE) was 19.1–22.6 J, and the normal zone propagation velocity (NZPV) was 2.4–2.7 mm/s at 0.977 $I_{{c}}$ in liquid nitrogen. MQE was 2.85 J at 0.86 $I_{{c}}$ , and NZPV was 2.7 mm/s at 77 K in conduction cooling. A 2G HTS coil cowound with an SS tape was robust in the event of the quench induced by heater and overcurrent flow above critical current.

Screen Elements Made of Perforated Steel Tape and their Application for Shielding Electromagnetic Fields

In the present work the methods for producing flat and three-dimensional shielding screens from the perforated steel tape are proposed. The possible application variants of mentioned screens are offered and analyzed. Main attention is given for producing one-layer and multi-layer screens with cellular structure due to its relatively low weight and technological elasticity – complex three-dimensional structures could be done successfully.Examples of produced shielding screens from the perforated steel tape for protection from electromagnetic fields in different frequency range are offered and tested. The efficiency of a shielding material was determined by measuring the magnetic field before and after applying the shielding material. Distribution of the magnetic field behind the shielding screen was determined by software vector mapping. Shielding efficiency was measured for 1) a three-layer perforated steel screen; 2) an one-layer perforated steel screen - shielding screen was placed in between the magnetic field source and the measurement point forming a two dimensional screen; 3) copper composite sprayed screen. During experimental investigation it was established, that a three-layer perforated steel screen application allowed the 27% reduction in the magnetic field, while one-layer perforated steel screen gave only 12% reduction. Copper composite sprayed screen reduced magnetic field by 15%.Recommendations for producing the multi-layer perforated steel screen accordingly to shielding efficiency are elaborated and laid down. The discussed material carries also ecological significance, since the material is produced by waste products (after stumping etc.). Therefore the production of such materials comes with reduced cost both in light of capital expenditures and ecological footprint.

Educating Students with Land Surveying

This descriptive research focuses on the role of land surveying in the development of an architectural plan starting at the initial architectural sketch through the detailed engineering planning which will leads smoothly to the construction phase. It comprises a leveling network that has been established and all points have been described completely. Parameters such as horizontal distance, horizontal angles and elevation differences between all points were measured through many closed leveling loops using theodolite (Leica Builder 300), tape measure & wheels (steel tape) and stave (leveling rod). The observations were used in a mathematical model and processed by traverse adjustment techniques. It is essential to check the error of closure for interior angles and for both latitude and departure before applying the double meridian distance (DMD) method to obtain the required area of the land. The adjusted unknowns and observations were computed precisely to about a few millimeters accuracy. Technical descriptions of the land such as distance, bearing, boundaries and area are necessary to visualize the shape & exact location of the land.

The method of “double thickness” for studying heat transfer from metal tapes to liquid nitrogen

To study heat transfer from a metal surface, the method of “double thickness” is proposed, in which the heating of the central region of a conductor and its average temperature are measured. As a result, the surface temperature is determined directly under stationary cooling. The method was tested to measure the characteristics of the heat transfer from a stainless steel tape to liquid nitrogen.

Reinforced concrete beams strengthened with SRP/SRG systems: Experimental investigation

Steel reinforced polymer (SRP) and steel reinforced grout (SRG) have emerged as promising and cost-effective technologies for the external strengthening of RC structures.Although the first studies date back to 2004, so far the literature related to the flexural strengthening of RC slabs/beams with steel tapes is rather limited. As a result, the application of such materials on a real structural member may be discouraged and, conversely, the use of carbon/glass FRP alternative systems may be preferred.The study presented in this paper contributes to filling this knowledge gap by presenting the results of 10 four-point bending tests performed on RC slabs strengthened with SRG/SRP systems. Test results have provided valuable information in terms of maximum forces, deformability and failure modes by varying number of layers and density of the steel tape. In particular, it has been shown that, disregarding the nature of the matrix (inorganic or polymeric), the presence of the external strengthening significantly increased the flexural strength of slabs, with percentage increases over the control (unstrengthened) member ranging from a minimum value of 27%, when using a single layer of low density tape, to a maximum of 106% in the case of SRP system with one layer of high density sheet.Preliminary analytical studies were also performed in order to investigate the possibility of extending to the SRP/SRG systems the applicability of formulations currently reported in some national and international guidelines for the flexural strengthening of RC members with FRP sheets.

Effects of AC Disturbance on Cowinding HTS Coils According to the Inserted Materials

Alternating field causes energy loss due to induced back electromotive force (EMF) to high-temperature superconducting (HTS) coils in the superconducting electric machines. Therefore, a method of reducing the effects of the alternating fields on the HTS coils in superconducting machines according to the winding insulation conditions has been investigated. In addition, the HTS coils cowound with turn-to-turn inserted materials to control the time constant has been proposed. The charge-discharge delay can be determined with the time constant, also the time constant is related to the radial directional resistance of the no-insulation coil. The variation of the radial resistance would affect the reduction effect of ac disturbance on the no-insulation coil. Therefore, trade-off between the reduction effect of the alternating disturbance and charge-discharge delay could be considered. In this paper, we evaluated the effects of alternating magnetic fields on the HTS coils according to the varying radial resistance caused by cowinding method with metal tapes in liquid nitrogen. Four types of the HTS coils are: 1) no-insulation coil, 2) cowound coil with copper tape, 3) cowound coil with stainless steel tape and 4) insulation coil which have different radial resistance respectively. The experimental result shows that the co-winding method can be applicable in the superconducting electric machines.

Non-Destructive Examination of Jacket Sections for ITER Central Solenoid Conductors

The Japan Atomic Energy Agency is responsible for procuring all amounts of central solenoid (CS) conductors for International Thermonuclear Experimental Reactor, including CS jacket sections. The conductor is cable-in-conduit conductor with a central spiral. A total of 576 Nb 3 Sn strands and 288 copper strands are cabled around the central spiral and then wrapped with stainless steel tape whose thickness is 0.08 mm. The maximum operating current is 40 kA at magnetic field of 13 T. CS jacket section is circular in square type tube made of JK2LB, which is high manganese stainless steel with boron added. Unit length of jacket sections is 7 m, and 6400 sections will be manufactured and inspected. Outer/inner dimension and weight are 51.3/35.3 mm and around 100 kg, respectively. Since the CS conductor suffers 60000 cycles of high electromagnetic force in the lifetime, severe requirements were specified for jacket sections in terms of not only high mechanical performance at 4 K but also of the size of initial defects in the jacket section. The minimum allowable defect size is estimated to be 2 mm2 × 0.2 mm by linear elastic fracture mechanics. Eddy current test (ECT) and phased array ultrasonic test (PAUT) were developed for non-destructive examination. The defects on inner and outer surfaces can be detected by ECT. The defects inside the jacket section can be detected by PAUT. These technologies and the inspected results of more than 700 jacket sections are reported in this paper.

Microstructure characterization and tensile properties of Mg/Al dissimilar joints manufactured by thermo-compensated resistance spot welding with Zn interlayer

Abstract Thermo-compensated resistance spot welding (RSW) with a Zn interlayer was designed to join AA5052-H12 (Al) aluminum alloy to AZ31B (Mg) magnesium alloy. A stainless steel tape placed between the upper electrode and the Al sheet acts as a heat barrier to prevent heat loss from the spot nugget on the Al side. During welding, more Al was melted to increase the percentage of Al in the liquid nugget. In the resultant Mg/Zn/Al joints produced by thermo-compensated RSW, the formation of Mg–Al brittle intermetallic compounds is restricted. The tensile–shear properties of the weld joint were improved significantly. The failure load of the Mg/Al joints was up to 2199 N, compared with the 833 N and 727 N that is produced by traditional Mg/Al RSW and Mg/Al RSW with Zn interlayer, respectively.

Instrumental Assistance to the Restorative Dentistry Treatments

In dental care is necessary to isolate the tooth the oral environment (saliva, tongue, cheek, etc) with some type of retractor. This work aimed to propose a new model of instrumental low cost that assists in dental treatment. The instrumental was virtually designed and tested with the characteristics of the materials used in its manufacture: Solid stainless steel wires of 7 mm, acrylic resin and steel tape. To simulate its functionality was modeled a mouth with the actual measurements via the free software Blender 2.49b. To evaluate the simulation results of the test type black box, where you can observe the operation of the simulator were used. After testing various virtual instruments with the same measurements to assess its performance were made clinically. It was concluded in the simulation and clinical tests that the instrument is stable and performs the removal of anatomical structures adjacent to the tooth, even in cases of patients with positive macroglossia can be used for different types and sizes of arches, in the absence of any tooth can be fixed in any tooth, getting the desired position by professional optimizing the same time.

Application of Hard Metal Weld Deposit in the Area of Mixing Organic Materials

Any machine part is subject to degradation processes. Intensive wear occurs either when two bearing surfaces come into contact or when loose particles rub the function surface of a machine part. Soil processing machines are a good example. A similar process of abrasive wear occurs also in mixing machines or lines for material transport, such as worm-conveyors. The experiment part of this paper analyses hard metal weld deposit dedicated for renovation of abrasive stressed surfaces. In order to prolong the service life of a blade disc in a mixing machine Kreis-Biogas-Dissolver, the technology of hard surfacing by an electric arc was used. Tested hard metal electrodes were applied on a steel tape class 11 373. To eliminate mixing with the base material, weld beads were applied in two layers. Firstly, the weld bead was visually analyzed on a binocular microscope. Further, weld bead as well as the base material was analyzed from the metallographic point of view, whose aim was to identify the structure of weld metal and the origin of microcracks in weld bead. Moreover, there was also measured microhardness of weld metal. Abrasive resistance was tested according to the norm ČSN 01 5084, which is an abrasive cloth test. As in the mixing process also erosion wear occurs, there was also processed a test on a Bond device simulating stress of test samples by loose abrasive particles. The abrading agents were formed by broken stones of 8–16 mm in size. Based on the results of the individual tests, the recommendation of usage hard metal electrodes for prolonging service life of machine parts will be made.

Anthropometric estimation of body height after surgical correction of scoliosis.

To estimate the height loss in 28 patients who had undergone surgery for scoliosis before skeletal maturity. 28 women patients aged 11 to 18 (mean, 15) years underwent Harrington instrumentation, segmental sublaminar wiring, and posterior spinal fusion for idiopathic scoliosis. The patients' mean age at menarche was 13 (range, 10-16) years. Pre- and post-operative radiographs of the spine were taken to determine curve types, the Cobb angle, and the degree of correction. The standing and sitting heights were measured using a flexible steel tape, and the expected standing and sitting heights were derived using formulae. At the final follow up, the mean patient age was 20 (16-32) years. The mean standing height was 155.2 cm and the mean sitting height was 77.4 cm. Using the formulae, the mean expected standing height was 158.4 cm, indicating height loss of 3.2 cm (t=4.6, p=0.0001), and the mean expected sitting height was 79.9 cm, indicating height loss of 2.6 cm (t=3.84, p=0.001). The curve types of the 28 patients were sub-divided as thoracic (n=7), thoracolumbar (n=18), and double major (n=3). Patients with thoracolumbar curves achieved better correction and less loss of standing and sitting heights. Percentage loss of standing and sitting heights were not correlated with the apex of the curve or the degree of correction. Height loss after surgery was acceptable in comparison with height loss associated with progression of scoliosis without surgery.

English

Aim: The purpose of this study is to determine the accuracy of arm span as a measure of height among the Urhobos in Delta State of Nigeria. Methods: The nature and scope of this study encompassed 401 adults (199 males and 202 females) aged 22 to 65 years from the Urhobo ethnic group in Delta State of Nigeria. Data was collected with subjects in the anatomical position. Height and arm span were measured with a stadiometer and calibrated steel tape respectively. Data analysis was carried out using Statistical Package for Social Sciences (SPSS), version 10.0. Means and standard deviations (SD) were obtained for both anthropometric variables. Results: The results revealed that the mean of the arm span for males and females were 184.56cm and 173.61cm respectively. The mean of the height was 173.0cm for male and 164.6cm for female. Conclusion: The arm span is a valid measure of height among adult Urhobos. Key words: Arm span, Height, Urhobo, Nigeria.

THE FRICTION MECHANISM BETWEEN SURFACES WITH REGULAR MICRO GROOVES UNDER BOUNDARY LUBRICATION

The results of research related to the influence of partially regular microrelief parameters on the adhesion component of the friction factor under boundary lubrication are presented. It has been shown that micro grooves are effective under boundary friction on precision surfaces with low roughness when lack of film and probability of seizure appear. The deformation component of the friction force of surfaces with micro grooves has been studied. The time of micro running-in was the key factor while assessing the dependence of the deformation component on friction when taking into account the depth of micro grooves and their relative area. The research was conducted using a tribometer according to the friction model entitled “shaft & flexible steel tape”.

Analysis of Double Meridian Distance for a Closed Traverse Area towards Developing a Contour Map and Land Title

This research aimed to analyze double meridian distance for a closed traverse area in developing a land title for a propose gymnasium in Qassim University. Theodolite, leveling rod and steel tape plays an important role in measuring elevations, bearings and distances of the boundaries of a lot. Contour map is necessary to determine the traces of level surfaces of successive elevation. This will enable to identify the type of contour map and type of contour lines necessary for this project. Corel draw software is used to draw contour map and guide to interpret the significance of the variables. It is essential to check the error of closure for interior angles and for both latitude and departure before applying the Double Meridian Distance (DMD) method to obtain the total area of the lot. Technical descriptions of the land such as distance, bearing, boundaries and area are necessary to visualize the shape & exact location of the land. Developing a land title will be obtained using the technical descriptions of the lot in preparation for the type of gymnasium necessary for Qassim University.

The effects of co-wound Kapton, stainless steel and copper, in comparison with no insulation, on the time constant and stability of GdBCO pancake coils

Recently, studies of partially insulated, high-temperature superconducting (HTS) coils have shown application in the design and construction of compact, stable and self-protecting HTS coils. This article presents the electrical characteristics of HTS coils based on the turn-to-turn inserted materials and conditions. Three partially co-wound pancake coils were fabricated and tested. Each coil was partially co-wound with Kapton, stainless steel and copper tape at every fourth turn of the winding. Tested coils were co-wound on every turn with Kapton, stainless steel and copper tape, and coils without turn-to-turn insulation were the control group. Charge–discharge, sudden-discharge and over-current tests were performed to evaluate the performance of the fabricated coils. The experimental results show that the properties of materials inserted into the coil can control the time constant (τ). Therefore, HTS coils can be designed for specific purposes according to the time constant control. The experimental results of the study could be useful in designing HTS coil applications.

Biomimetic deposition of hydroxyapatite on the surface of silica thin film covered steel tape

The biomimetic deposition of hydroxyapatite (HA) on the surface of SiO2 thin film coated metal substrates was developed and investigated.The structural investigations of HA were made by XRD and FTIR-ATR, while morphological and chemical changes during HA biomimetic deposition on the surfaces of silica thin films were investigated by SEM with EDS.The HA film thicknesses were estimated from the mass changes of samples including the corresponding correction of the pore volume inside of them, which was calculated by the Lecloux and Pirard method based on the Dollimore–Heal method.

A motorized 5 m tape comparator for traceable measurements of tapes and rules

A motorized 5m tape comparator was constructed in TUBITAK UME for calibration of tapes and rules up to 5m length in one set-up and further lengths in multiple set-ups. The system is a practical development and provides a cost effective solution for calibration of tapes in which the highest grade’s accuracy requirement in OIML R35-1 e.g. is 600μm for 5m length and 1100μm for 10m length. It is mainly composed of 6m rail system, mechanical parts, optical units and an integrated 6m incremental linear encoder as a reference measurement axis for traceable measurements. The rails are kinematically located on a heavy marble construction and a motorized carriage, which employs a camera for probing of the scales on the tapes, is moved along the rails during the measurement. The image of the scale taken by the camera is viewed on the monitor screen together with the running software. The operator can perform the probing process by simply moving the carriage over the measured scales (tapes or rules) using a joystick. The carriage movement is measured by the incremental linear encoder previously calibrated by a laser interferometer and the software automatically takes the measurement results from the incremental linear encoder, applies correction values previously defined and determines the length of the tapes and rules as well as deviations from nominal lengths. The estimated expanded uncertainty of the steel tape measurement is U = 54μm in one set-up (for 5m length) and U = 77μm in two set-ups (for 10m length) at the confidence level of approximately 95%. Uncertainty budget for calibration of the device itself and for calibration of the test tapes are explained in detail. The results of extensive experimental work and analysis are provided by demonstrating application of science and technology of measurement and instrumentation. Investigations for long term stability of the system are given with the reported test results for the years of 2003-2011 and participated intercomparison results to validate the device scientifically are illustrated.