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To study the magnetic shielding of buried high‐voltage (HV) cables by adding conductive metal plates on the ground surface above the cables.

The field is calculated with eight rectangular conductive plates above the cables, positioned with their long edge either parallel to the cables or transversal to the cables. Here, the circuit method is used. In this method, the shield is replaced by a grid of straight filaments in which the unknown currents are searched by solving an electrical circuit.

It is observed from the calculation results that it is important to have a perfect electrical connection between adjacent plates. In the area above the shield, an “infinite” contact resistance between neighbouring plates results roughly in double field amplitude compared to the situation with contact resistance zero. The positioning of the rectangular plates (parallel or transversal to the cables) has not much influence on the shielding. The shielding efficiency as a function of the shield size is studied as well. The circuit method is validated by measurements on an experimental setup at reduced scale.

The circuit method is applied to conductive objects and not to ferromagnetic objects.

As the circuit method is rather fast also for 3D geometries with thin plates, the shielding of HV cables can be evaluated in a computationally more efficient way than by using, e.g. finite elements.

The circuit method is already described in the literature. The originality of this paper is the study – by this circuit method – of the effect of several parameters (size of the shield, contact resistance, orientation of the plates) on the shielding efficiency.

Detection of hidden defects of aluminum alloy plate with damping coating is a challenging problem. At present, only a few non-destructive testing methods exist to address this engineering problem. Without the restriction of skin effect, remote field eddy current (RFEC) overcomes the interference caused by the damping coating. The RFEC, which has potential advantages for detecting the hidden defects of aluminum plate with damping coating, can penetrate the metal plate to detect buried depth defects. This study aims to test how thick the RFEC sensor can penetrate the metal plate to detect the buried defects.

The magnetic field distribution characteristics are analyzed, the magnetic field intensity distribution is calculated, and the structure and parameters of the coil, magnetic circuit and shielding damping are determined through the two- and three-dimensional finite element simulation methods. Optimal excitation frequency is obtained, and the distance between the excitation coil and detection coil is determined by analyzing the relationship between excitation frequency and remote field points.

Simulation and experimental results verify the feasibility of applying the RFEC detection technology in detecting the hidden defects of aluminum alloy plate with damping coating.

In this paper, the RFEC testing model of hidden defects in aluminum plate sample with damping coating is established by using the finite element method.

Insoluble and therefore oxygen developing anodes tend to destroy additives in plating baths. With a modified mixed metal oxide coated anode, it is possible to reduce the consumption of additives in copper electrolytes and to reduce the formation of Sn⁴⁺ in acid tin electrolytes. Favourable applications for this new anode type are under discussion.

The purpose of this paper is to develop a capacitance vehicle weighing device. The key part of this device is the capacitance vehicle weighing sensor. This paper discusses the static and dynamic performance test of capacitance vehicle weighing sensor with emphasis, and provides theoretical analysis, in order to provide the tests and theoretical basis for the popularization and application of the vehicle weighing device.

The paper gives an introduction to the weighing sensor in respects of the structure design and measuring principles, with the emphasis on the static and dynamic performance of the testing processes. Then, the paper provides the corresponding testing processes and data with theoretical analysis.

This weighing sensor can be applied to static as well as dynamic tests thus the capacitance vehicle weighing device is practical and worthy of promotion and popularization.

The capacitance vehicle weighing device is characterized by its simple structure, simple measuring circuits, strong reliability in anti‐interference, small size and low cost. The static performance is of little repetitive error, and the use of software may efficiently solve the problems of non‐linearity and hysteresis. In dynamic measurement, the speed, acceleration and vibration of the vehicle produce little effect on the result, which can be neglected, thus being able to overcome the disadvantages of the traditional weighing method which is of low speed and great errors.

In some developing countries, vehicles are often over‐loaded, which causes road accidents and damage to road surfaces. Currently, large measuring facilities are used to measure the vehicle‐loading on highways. A major limitation is that they can measure vehicle‐loading at fixed locations only. This paper seeks to present an on‐vehicle loading measurement system with capacitance and acceleration transducers.

A description and analysis of the system are presented.

The capacitance transducers sense the variation in distance between electrodes, using the on‐vehicle leaf springs as weighing elastomers. The acceleration transducers deal with the influence of acceleration to vehicle‐loading measurement. The major advantage of this system over the existing systems is that both static and dynamic loading can be measured.

This system is simple and easy to install.

The paper shows that with this system both a driver and an inspector can check vehicle‐loading at any time and any location through radio communication, thus identifying over‐loaded vehicles on highways.

The purpose of this paper is to present a new device (thermoelastic actuator) for accurate control of position whose principle is based on thermal dilatation of its working unit brought about by induction heating.

The device must satisfy the prescribed operation parameters (mainly the above thermal dilatation). The task to find them is a multiply coupled problem (interaction of electromagnetic field, temperature field and field of thermoelastic displacements) that is solved by the finite element method supplemented with a number of other procedures.

The control of position based on the described thermoelastic effect is very accurate and ranges from 1×10⁻⁶ to 1×10⁻³ m.

The device also contains two self‐locking friction clutches of conical shapes whose purpose is to fix the position of the plunger in the prescribed position. Further attention should be paid to their dynamic behaviour during the process of fixing.

The device can be used in various technical domains such as optics and laser or microscope techniques.

The principal part of the device contains no movable element, which is a substantial advantage in comparison to other systems based on mechanical, hydraulic or pneumatic principles working with movable elements or media.

High density packaging mounted VLSI demand highly dense and highly accurate multilayer printed wiring boards. The authors have studied Ultra Thin Copper (UTC) technology of printed wiring boards for application to the packages of high speed and high performance computers for more than 10 years. This paper describes the requirement for fine line and highly dense multilayer printed wiring boards and the study of the development of a suitable process using the UTC. The discussions include the behaviour of pattern etching and effects of plating thickness, the improvement of plating thickness uniformity, the selection of carrier types, the measurement of peel strength between copper foil and substrate, and so on. The UTC application reduces the defects caused by surface contamination of epoxy resin. Degradation of surface resistance is also discussed, which may be caused by surface creeping of alkaline ions arising from residues of plating solution within the plated‐through hole wall. These investigations could establish UTC technology for fine line printed wiring boards.

To analyze effectively magnetic shielding effects by shields with fine structure.

Simplification of the fine structure makes it possible to analyze them efficiently. The authors have introduced a homogenization method to estimate effective permeability of magnetic composite structure for the static field. The homogenization method is applied to the analysis of magnetic shields composed of steel plates and steel rods against DC power lines to test its feasibility.

The properties of the magnetic shielding are analyzed by using the homogenization method. The errors of the magnetic fields increase in case of very few layers.

The simplification of the magnetic shields with fine structure by using the homogenization method makes it possible to analyze efficiently magnetic shielding effects, although the accuracy becomes worse in case of very few layers.

The calculation of magnetic shielding with ferromagnetic material by an effective reluctivity method and a time step method based on the finite element calculation is investigated. The calculation results of both methods are compared with measurement results and with each other in order to check their reliability and accuracy. It turns out that both methods give similar results for the field inside the shielding material, whereas in the surrounding air the effective reluctivity method gives more accurate results than the present time step method.

The Giant MagnetoResistance (GMR) effect, discovered in France in 1988, has already been applied in magnetic sensors and has promise in other applications. The rapid acceptance of this technology is due to GMR’s unique characteristics such as high sensitivity, good temperature stability, and excellent linearity over a wide sensing range. In this article GMR materials are described as are their application in magnetic field sensors. New GMR structures utilizing spin valves and spin dependent tunneling (SDT) will offer even more potential for expanding the horizon of solid state magnetic sensing. Comparisons are made to sensors using conventional technology. Integrated GMR sensors that have signal conditioning and output electronics monolithically integrated with the sensor offer further uses of this new technology. Beyond the sensor itself, other control system functions have the potential for using the same GMR materials to make magnetic isolators and nonvolatile memories.