Finite Element Analysis of Magnetic Field Single-Turn Systems
Modelling of pulsed magnetic systems has extensive application in the optimisation of electromagnetic metal forming as well as in pulsed ultrahigh field generation systems. This paper presents a detailed three-dimensional finite element analysis model to be used in such power systems and compares simulated solutions with accurate experimental data.
A fast and compact θ-pinch electromagnetic flux-compression generator
Ultrahigh magnetic fields up to 300 T (3 MG) have been generated by electromagnetic flux compression using only 63 kJ from a fast capacitor bank to implode aluminium liners, with 14.7 kJ from a slow capacitor bank needed to provide an initial magnetic field. With no initial field present, pulses of magnetic flux density having a time rate-of-change exceeding 3 × 108 T s−1 have been produced and measured, opening the way for a range of dynamic transformer applications. The outcome of the work suggests that, when using fast multi-MA banks, flux compression can be viewed as an alternative to the single-turn coil technique that will move the boundary of the magnetic fields well beyond 300 T without the need for significant additional investments.
The Inca Occupation of the South Coast of Peru
like the others, however; it forks into several nearly parallel ravines of which the largest are Huayuri, Rio Grande-Palpa, Ingenio (called Collao in ancient times), Nasca proper (the ancient Caxamarca), Taruga, and Poroma. Due to peculiarities of the local topography, the irrigated areas in Ica and the ravines of Nasca are located inland, at the foot of the mountains, rather than at the mouths of the rivers as is more usual in Peruvian coastal valleys. No sharp natural or cultural boundary separates the valley of Chincha from the valleys of Cafiete (ancient Huarco and Runahuana), Asia, and Mala, the next valleys going up the coast to the northwest. At the other end of the area we are considering, however, there is a sharp break; beyond Yauca the Andean foothills reach out to the sea, natural conditions are quite different, and there are important differences in the archaeological picture as well. The historical sources which mention the south coast are not particularly helpful, except in so far as they provide us with a few dates. To begin with, no chronicler gives an explicit account of the political organization of the south coast at the time it came into contact with the Incas. It can, perhaps, be inferred from Cabello Balboa's statements about common policy toward the Inca invaders that there was some sort of political connection between the valleys of Mala, Cafiete, and Chincha, but the connection need have been no more than a temporary military alliance. Cabello makes no mention at all of Pisco. The valleys of Ica, Nasca, and 125