Shields

About: Shields is a research topic. Over the lifetime, 1456 publications have been published within this topic receiving 10896 citations.

Minimizing the three-phase unbalance in an electric arc furnace

Abstract: A method is proposed to reduce impedance imbalance in the electrode arms of an arc furnace. Conducting plates or tubes are used to shield the magnetic fields around busbars in order to minimize the mutual inductance. The volume integral equation method is used to calculate bus impedances, current distribution, and eddy current losses. The numerical results indicate a significant improvement in system balance even during bus movement. Two types of shields are investigated. Shielding the center phase by using a large tube reduces the unbalance at the coplanar bus positions, but it has little effect when one bus is offset. Shielding by two conducting plates standing between buses yields good balance and constant reactance for all bus positions. The power loss in the shields is only a small percentage of the bus loss, the shields can be replaced by parallel conducting bars bounded at ends. By combining the new method with a smaller center bus diameter, better results have been achieved. >

Improved meteorological measurements from buoys and ships (IMET) : preliminary comparison of solar radiation air temperature shields

Abstract: Several different types of solar radiation air temperature shields are evaluated for use at sea on ships and buoys. They include three types of static or Thaller shields, two vane oriented shields, and two fan ventilated shields. A preliminary data analysis is presented and

The Efficiency of Radiation Shields

Abstract: The effect of a number of thick radiation shields of infinite thermal conductivity and of a type realizable in practice is analyzed by matrix algebra, and a method for calculating the temperatures of the various shields is also given. For identical thin shields it is found that the ratio of the power required to maintain a radiating surface of emissivity e0 at a given temperature with N shields to the power required to maintain the same temperature without shields is given by [1+e0(f+f2+f3+···fN)(1ek+1el−1)]−1, where ek, el are the emissivities of the two sides of a shield and f is the fraction of the radiation leaving the inside of the nth shield which is incident upon the n−1th shield.

Method and apparatus for inspecting component, and manufacturing apparatus

Abstract: PROBLEM TO BE SOLVED: To achieve a method and apparatus for inspecting a component for managing performance and deterioration degree for each component by detecting unique impedance with high sensitivity and high accuracy, and by quantitatively comparing the difference between components SOLUTION: A component (1) to be measured is closely stuck on a lower electrode (3) and an upper electrode (4) in electromagnetic shields (2, 6) The lower electrode and the shields are grounded, the upper electrode is insulated from the shields by an insulator (5), frequency is swept from a network analyzer (8), and a high-frequency signal is supplied to the upper electrode Accordingly, its impedance is measured COPYRIGHT: (C)2006,JPO&NCIPI