AC Loss Calculation of REBCO Cables by the Combination of Electric Circuit Model and 2D Finite Element Method

AbstractThis study investigates the losses in a two conducting-layer REBCO cable fabricated by researchers at Furukawa Electric Co. Ltd. The losses were calculated using a combination of my electric circuit (EC) model with a two-dimensional finite element method (2D FEM). The helical pitches of the tapes in each layer, P1 and P2, were adjusted to equalize the current in both cable layers, although the loss calculation assumed infinite helical pitches and the same current in each layer at first. The results showed that the losses depended on the relative tape-position angle between the layers (θ/θ’), because the vertical field between adjacent tapes in the same layer varied with θ/θ’. When simulating the real cable, the helical pitches were adjusted and the layer currents were calculated by the EC model. These currents were input to the 2D FEM to compute the losses. The losses changed along the cable length because the difference between P1 and P2 altered the θ/θ’ along this direction. The average angle-dependent and position-dependent losses were equal and closely approximated the measured losses. As an example to reduce the loss in this cable, the angle and the helical pitches were fixed at θ/θ’ = 0.5 and P1 = P2 = 100mm (S-direction). The calculation with these conditions indicated that the loss is about one order of magnitude lower than the measurement

The Japanese Problem, Sociology Assignment

https://scholarlycommons.pacific.edu/cook-nisei/1009/thumbnail.jp

Evaluation of the System of Disaster Management Resulting from War Operations and Terrorism in Iraq

Nowadays the science of disaster and crisis management is considered as one of the important sciences all over the world. Therefore, disaster management is considered an important and common subject that requires great efforts. So continuous research is one of the important ways to establish the best methods to evaluate and develop the management of disasters and crises. Such methods are appropriate to deal with the suffering that many countries experience from natural and environmental disasters from time to time. This research aims to show the significance of disaster and crisis management in general. It also explores the current situation related to disaster response management in Iraq. This exploration focuses on the achievement of the basic functions of the management operation (planning, organizing, directing, controlling). In addition, it identifies the weaknesses and the strengths of the current administrative system in all its elements and analyses all the problems and the defects in every element, in order to treat and solve these problems and defects by making recommendations to improve the immediate response system to serve Iraqi disaster management in the future. In order to satisfy this aim, data collection included information obtained from literatures relating to disaster and crisis management. In addition, other information was obtained from a field survey of the directories of the civil defence in Iraq. Furthermore, collective and personal interviews with specialists related to disasters and crisis resulting from the war operations and terrorism were conducted. Analysis of the data results revealed many weak points in the current system and this was confirmed by the field survey. It showed us more clearly the areas where the weak points appear in the management function, especially in the planning and organization functions. One of the most important weak points is the absence of heavy equipment, as well as the shortage of specialist engineering staff and a dependence on assistance from other service departments. This is because of the local roles and the departmental management in the government. Finally, the study reached a set of conclusions and recommendations, including providing the directories of the civil defence with the heavy rescue equipment and providing specialist trained engineering staff to deal with the disasters and crises. Moreover, it sets in place an incentive scheme for the related members of the directories of the civil defence. Such schemes encourage them to continue working to face the unnatural circumstances that Iraq is experiencing and to create an environment similar to that of developed countries in the world. This contributes to overcoming the disasters of all shapes and reduces the damage to lives and property