Research on maintenance tools of wire clamps for live working on Ultra High Voltage transmission lines

Aiming at the problem that the suspension clamp is difficult to be quickly replaced due to the heavy load of the suspension clamp when replacing the transmission line wire suspension clamp in the UHV live operation, this paper develops an auxiliary device for realizing the rapid replacement of the conductor suspension clamp. Through the design of fixtures suitable for the installation of UHV wires and connecting plates, the load transfer of the suspension clamp can be quickly realized, and the suspension clamp can be separated and replaced under the condition of no force. The device is flexible and light, and effectively improves the live working personnel work efficiency.

Improving the Female Silhouette and Gluteal Projection: An Anatomy-Based, Safe, and Harmonious Approach Through Liposuction, Suspension Loops, and Moderate Lipofilling

Background Liposuction is the main technique to improve body contour, emphasize appealing curves, and highlight one’s muscular definition. The number of procedures in which the harvested fat is utilized for gluteal augmentation has greatly increased. Objectives The authors aim to demonstrate their technique in order to obtain a sculpted harmonious body through a safe procedure, as well as review their 101 consecutive cases between 2014 and 2018. Methods Anatomical guidelines and preoperative markings were provided to guide the 3-step procedure: zones of maximal and mild liposuction, barbed wire suspension, and moderate fat grafting. Novel concepts are introduced as the anterior body diagonal, posterior body diagonal as well as other specific axes the pubic unit, and a vertical ratio for the buttock, which are the basic foundations for sculpting the female body into a pleasing hourglass shape with a well projected buttock. Recommendations for location of sacral diamond, sacral dimples, and the maximally projected point of the buttock are given. The authors explain their philosophy through 4 principles: knowledge of anatomy, the relationship between specific body areas and surrounding zones, a balanced gluteal augmentation is not achieved through large volume fat grafting alone, and grafting in the subcutaneous layer. Results A total of 101 patients were treated following the described technique and examples are shown. The complication rate was low. No serious adverse effects were recorded apart from 1 ruptured suspension loop. Conclusions The described anatomy-based approach, including liposuction, suspension loops, and fat grafting, is a novel and safe technique leading to a desirable, long-lasting outcome. Level of Evidence: 4

Mechanical Calculation of Flexible Wires Loaded with Concentrated Loads

Calculating of wires sag and tension under various modes is the task of mechanical calculation. The article derived formulas for the curve of the wire sag under the action of one or several concentrated forces and with various tensioning insulators strings in the span. Formulas for estimating the distance to the maximum sag have been obtained. Based on the length of the system of “first tension insulators string – conductors – second tension insulators string” that depends on the supporting beam reactions and beam lateral forces in the corresponding sections, the system load factor was determined taking into account structural elements for different climatic loads. The formulas to calculate the load factor for solving the equation of state in the case of different insulators strings in span loaded with one or several concentrated forces have been obtained. The resulting expressions can also be applied in case of horizontal wind loads; in this case the equation of state should take this component into account when calculating the resulting reduced load on the wire in an inclined plane. The reliability of the formulas was proved by the coincidence of the results for the particular case of the arrangement of the insulators strings. An algorithm for calculating sag under the combined action of vertical and horizontal loads, as well as in the case of the location of wire suspension points at different heights, is given. A formula has been proposed for estimating the sag increase factor due to the presence of concentrated forces uniformly distributed along the span and various insulator strings in the span. The dependence of the coefficient of increase of the sag on the distance to the concentrated force in the presence of one and two forces in the span is drawn.

Automated Inspection of Railway Tunnels’ Power Line Using LiDAR Point Clouds

Transport networks need periodic inspections to increase their safety and improve their management. In the last few years, LiDAR (light detection and ranging) technology has become a tool for helping to create a precise database of almost any type of infrastructure. Mobile laser scanning (MLS) systems use a laser beam to collect dense three dimensional (3D) point clouds, which include geometric and radiometric data of the environment in which they are placed. In the context of this paper, a methodology for automatically inspecting the clearance gauge and the deflection of the aerial contact line in railway tunnels is presented. The main objective is to compare results and verify their compliance with the Spanish norm. The 3D data are provided by a LYNX Mobile Mapper System (MMS). First, the area is surveyed and then the obtained (3D) point cloud is classified into contact wire, suspension wire, and remaining points. Finally, the inspection of the railway’s power line is performed. The validation of the proposed methodology has been carried out in three different tunnel point clouds, obtaining both qualitative and quantitative results for points’ classification, together with the results of the measures performed.

The Number of Power Line Spans Accounting in Determining the Induced Voltage

The article considers inductive interference components. A description of the induced voltage electromagnetic component is described in detail. The technique of the calculated wire suspension height determining based on the actual magnetic field distribution is presented. The technique for the number of power line spans determining is provided. Dependences of the magnetic field induction vector on the distance along one power line’s span are obtained. Relationships of the magnetic field induction determining error depending on the number of adjacent spans are obtained. Recommendations for the number of spans determining, which must be taken into account when evaluating the magnetic component of the power line electromagnetic field are given