Some effects of variable excitation on synchronous motor oscillation

In this paper are presented the results of a study of synchronous motor oscillations resulting from sudden application of mechanical load. By means of the Differential Analyzer at the Moore School of Electrical Engineering of the University of Pennsylvania, theoretical synchronous machine equations were solved for conditions of suddenly applied load, and the effect on the resulting oscillations of variations in field excitation was determined for the most practical cases. The analyzer results were checked by a number of experimental observations, and it was found that the magnitude and duration of the oscillations could be greatly decreased by using the proper type of excitation variation.     

The social stratification of theatre,dance and cinema attendance

In current sociological literature the relationship between social inequality and patterns of cultural taste and consumption is the subject of a large and complex debate. In this paper the primary aim is to examine, in the light of empirical results from a research project in which the authors are presently engaged, three main, and rival, positions that have been taken up in this debate, here labelled as the ‘homology’, the ‘individualization’ and the ‘omnivore–univore’ arguments. Elsewhere, we have concentrated on musical consumption in England, and find evidence that is broadly supportive of the omnivore–univore argument. Here we ask whether such findings are confirmed in the case of theatre, dance and cinema attendance. A secondary aim of the paper is to bring to the attention of practitioners in the field of cultural policy and administration the need to address the issues that arise through the use of more powerful methods of data analysis than those often applied in the past. We explain how indicators of theatre, dance and cinema attendance derived from the Arts in England survey of 2001 can be subject to analysis so as to reveal two distinctive patterns of attendance and, in turn, two distinctive types of consumer—who can, it turns out, be regarded as omnivores and univores, even if with some qualification. The former have relatively high rates of attendance at all kinds of the events covered, including musicals and pantomimes as well as plays and ballet, while the latter tend to be cinema-goers only, that is, non-consumers of theatre and dance. A range of measures of social inequality are then introduced into the authors' analyses, including separate measures of social class and social status and also of educational level and income, and it is further shown that, again in conformity with the omnivore–univore argument, these two types of consumer are socially stratified. Omnivores are of generally higher social status than univores and also have usually higher levels of education and higher income than do univores (the latter finding marking the main difference with musical consumption, which was unaffected by income once other stratification variables were controlled). In sum, our results for theatre, dance and cinema attendance lend, overall, further support to the omnivore–univore argument as against its rivals, but also indicate that different aspects of social inequality impact on different forms of cultural consumption in varying degrees and probably through largely separate processes.     

“Fear God; Fear the Bogaze”: The Nile Mouths and the Navigational Landscape of the Medieval Nile Delta,Egypt

By the fourth/tenth century, Egypt's Nile Delta had just two major Delta branches debouching directly into the Mediterranean – the Dumyā? (Damietta) and Rashīd (Rosetta). Navigational conditions at these branches’ mouths were treacherous because of a combination of currents, winds, wave-fields and shifting sandbanks. These conditions were a danger to shipping, and so had a formative effect on the navigational landscape of the Delta. Despite its remoteness from the Nile, Alexandria remained Egypt's chief Mediterranean port, but only because river connections were maintained that avoided the Rashīd mouth. In contrast, the port of Rashīd was relatively insignificant. Similar conditions at the Dumyā? mouth prompted navigators to adopt routes via Lake Tinnīs, modern Lake Manzala, which linked to the sea through its calmer sea mouths. This article brings together material from multiple disciplines to offer a new understanding of the navigational context of Egypt's medieval Mediterranean ports.