Flexible Steel Cables Research Articles

Differential triboelectric nanogenerator for transmission line vibration suppression and energy harvesting in the grid

The large vibration of the transmission line caused by wind and ice has brought about significant damage to the grid. The transmission line maintenance has a huge demand on energy supply. Therefore, a differential triboelectric nanogenerator (Di-TENG) for suppressing line vibration and energy harvesting is proposed, designed, analyzed and tested. The Di-TENG mainly consists of two fixed pulleys, two flexible steel cables, two pull springs, one generator unit and two guide rails. A model of the line covered with ice is established and theoretical analysis of the transmission line vibration suppression is implemented. The energy harvesting performance of the Di-TENG is also investigated. An energy harvesting performance testing platform and a transmission line oscillation system were built in the laboratory environment. A practical experiment was conducted on a real transmission line system. The experimental results show that the Di-TENG can decrease the vibration of an ice-covered transmission line by up to 28%. The Di-TENG can generate an open-circuit voltage of 180 V, a short-circuit current of 6.6 μA and a transfer charge of 73 nC, and a peak power of 0.73 mW. This study demonstrates the potential application of the Di-TENG for vibration suppression and energy harvesting in the grid. The Di-TENG provides new ideas for self-powered systems based on transmission lines.

Modeling and Capture Dynamics of Flexible Cables Used in Large-scale Space End-effector

Flexible capture mechanism of large-scale space end-effector based on steel cables is developed with respect to an important space capture principle,namely large-tolerance and flexible capture.Owing to cable's flexibility and the difficulty in fast sequential modeling and control in space environment,a discrete control model of the flexible steel cables is established to solve the modeling problem of steel cables.Via the discrete model,dynamics for the end-effector's flexible steel cable capture mechanism capturing a space free-flying carry cargo is analyzed.Experiments show that the steel cable model is correct and the derivation of the capture dynamics is reasonable.

Development of Chinese large-scale space end-effector

In order to achieve large tolerance capture and high stiffness connection for space payload operations, a Chinese large-scale space end-effector (EER) was developed. Three flexible steel cables were adopted to capture the payload with large capture allowance. Ball screw transmission mechanism and plane shape-constraint four bar linkage mechanism were utilized to connect the payload with high stiffness. The experiments show that capture tolerances in X, Y, Z, Pitch, Yaw, Roll directions are 100 mm, 100 mm, 120 mm, 10.5°, 10.5°, 12°, respectively. The maximum connection stiffness is 4 800 N·m. The end-effector could meet the requirements for space large tolerance capture and high stiffness connection in the future.

A Computer Simulation Of An Alternative Design To Tree Crown Support Systems

Trees with multiple leaders that are susceptible to breaking pose a serious threat to nearby people and structures, and compromise overall tree health and aesthetics. The traditional remedy has been to install flexible steel cables in the crown of the tree in an attempt to limit the displacement of the leaders. This project was conducted to evaluate an alternative three-leader support cable system using computer simulation. The system is centered on a pulley that redirects loads along convergent cables, allowing for more displacement of the cabled leaders while minimizing the amount of materials and time required for installation. Comparisons between the traditional system and the alternative design were simulated using two-dimensional computer modeling to quantify the forces on the cables. The test winds were standardized at 43.45 km (27 mi) per hour for duration of 2 seconds. An interval of 18 seconds was allowed for the system to return to equilibrium for a total trial time of 20 seconds. Each system was standardized for cable diameter, damped springs, and distance between leaders with only the total length of cable varying according to the requirements of each system. Results demonstrated a significant decrease in both overall and shock forces to support cables when utilizing the alternative design. The decrease in force (based on cable configuration and wind direction) ranged from a 3.4:1 to 22.4:1 for the alternative and traditions systems, respectively.

Monte Carlo-aided dosimetry of a new high dose-rate brachytherapy source.

In this article we introduce a new high-intensity 192Ir source design for use in a recently reengineered microSelectron-HDR remote afterloading device for high dose-rate (HDR) brachytherapy. The maximum rigid length and outer diameter of the new source are reduced to 4.95 and 0.90 mm, respectively, compared to 5.50 and 1.10 mm for the previous source design introduced in 1991. In addition, a smaller diameter and more flexible steel cable are used, allowing the source cable to negotiate smaller diameter catheters or more tortuously curved catheters. Using Monte Carlo photon transport simulation, the complete two-dimensional (2-D) dose-rate distribution is calculated over the 0.1-7 cm distance range and are presented both as conventional 2-D Cartesian lookup tables and in the formalism recommended by the American Association of Physicists in Medicine Task Group 43 (TG-43) Report. The dose distribution of this source is very similar to that of its predecessor, except near the source tip and in the shadow of the cable assembly, where differences of 5%-8% are apparent. The accuracy of various methods for extrapolating beyond the tubulated anisotropy functions to short distances is evaluated. It is demonstrated that linear extrapolation from the anisotropy functions defined by TG-43 accurately (+/- 2%) estimates dose rate at short and long distances lying outside the radial distance range of the original measured data from which the anisotropy and radial dose functions were derived. In contrast, the algorithm used on the vendor's planning system results in large calculation errors at distances less than 5 mm.

Dinamometriade implementos montados: uma solução simplificada

Desenvolveu-se e testou-se um conjunto torre-braços articulados para engate ao sistema de levante hidráulico de implementos montados com apoio sobre rodas, mais especificamente unidades semeadoras-adubadoras de linhas múltiplas, para a determinação de suas exigências de tração. Como elemento sensor, usou-se um anel simples para tração/compressão, instruments do a extensômetros elétricos em ponte completa, conectado por cabos de aço flexíveis entre a barra do implemento e a base da torre intermediária. Projetado para trabalhos na faixa de 0-6.000N, submetido a testes de calibração estática, mostrou alta linearidade de resposta com R = 0,9997, um excelente retorno ao zero e resolução em torno de 70N. O conjunto, levado a testes com uma unidade semeadora-adubadora de sete linhas, em terreno firme, plano e inclinado, acusou esforços altamente consistentes com valores resultantes de cálculos simples; isso, aliado à simplicidade de sua concepção, confere-lhe um caráter de alta confiabilidade. O uso do conjunto altera a geometria trator-implemento, o que não constitui problema maior quando se está interessado em esforços de fração apenas, em se tratando desse tipo de implemento. Valores obtidos em trabalhos em terreno plano e preparado para plantio, bastante discrepantes dos encontrados em literatura, mostram a conveniência da execução de trabalhos sistemáticos para o conhecimento das reais necessidades de tração desses implementos em nossas condições.

Endoscopy

Gastroscopy Instruments Six years ago Kenamore described a biopsy forceps for the flexible gastroscope. In a study of gastric lesions by means of biopsy specimens removed endoscopically, Kenamore, Scheff and Womack46 presented 4 cases illustrating the value of the instrument as a positive method of differentiating benign and malignant gastric lesions. The instrument, which in trained hands is regarded as safe and as offering a method of more exact study of gastric diseases, is a flexible steel cable of fine caliber that can be attached externally to the gastroscope, whose diameter is thereby increased by only 3 mm. There is . . .

Tensile Tests on Flexible Steel Cable and Cable Ends

The following table is the result of a series of tests carried out at East London College (University of London) on various methods of mounting flexible steel cables, in cable ends.The specimens were kindly supplied by Messrs. T. W. K. Clarke and Co.Cables Nos. 1 and 3 were fixed in the following manner. The ends were knotted and tinned, then inserted in sockets or cable ends, and solder run in.

Tensile Tests on Steel Tape, Wires, and Flexible Steel Cable

The following tables are compiled from tests carried out at East London College on various materials of aeroplane construction, kindly supplied by Messrs. W. N. Brunton and Son, T. W. K. Clarke and Co., F. Handley Page, and H. EoUet and Co. Figure 1 shows the method of fixing the steel tapes during test. Table I. gives the results of these tests.

THE GYROMELE IN THE DIAGNOSIS OF STOMACH AND INTESTINAL DISEASES.

The gyromele (revolving sound) is a flexible steel cable, terminating in a more flexible steel spiral end. This spiral end is provided with a metallic pellet, and covered by a sponge, lamb's wool or cotton. The sound is fastened in a revolving apparatus—not unlike a surgeon's drill. After introduction into an accessible cavity of the body, if the revolving apparatus is put in motion, the rotations of the cable cause vibrations of varying degree which, being transmitted through the tissues, are perceived externally by means of auscultation and palpation. 1 Cables of different caliber and length have been devised in order to obtain cables of different degrees of flexibility and elasticity, which considerably broadens the scope of usefulness of the gyromele, especially for diagnostic purposes. 4 But it is not only the extraordinary adaptability, flexibility and elasticity which enable the instrument to enter cavities hitherto inaccessible, but the rotary motion