Pressure field in a tube with a general and arbitrary time- and position-dependent gas source

In this article we present analytical and numerical results for a pressure profile along the axis of a tube with a general and arbitrary time- and position-dependent gas source. The model is able to determine the pressure values along the tube, once the pumping speed at each extremity and the gas sources are specified. The time evolution of the pressure along a tube is presented for situations commonly found in high-vacuum applications, such as particle accelerators, colliders, storage rings, and synchrotron light sources. (C) 2004 American Vacuum Society.

Morphometric study of the small intestinal mucosa in young, adult, and old rats submitted to protein deficiency and rehabilitation

Linear and stereological morphometric methods were applied to the jejunal and ileal mucosa of young, adult, and old male Wistar rats submitted to protein deficiency and rehabilitation. The animals were fed ad libitum a 2% casein diet during 42 days and then received a 20% casein diet for 30 days. Food intake, body weights, and plasma protein concentrations were recorded. In the young protein deficient rats values of mucosal height, surface area, and volume of the lamina propria were significantly lower than those of their age controls in both jejunum and ileum. In adults the differences were less marked and in the old rats all parameters were found to be unaltered by the protein deficient diet. The surface-to-volume ratio showed no significant differences between control and protein deficient in all three age groups, meaning that villus pattern did not change with protein deficiency. On rehabilitation, a striking difference between jejunum and ileum was observed in the young rats; all parameters returned to control levels in the jejunum, while they remained lower than those of their controls in the ileum.

Crisis and contagion: some new and old ideas

Includes bibliography

Central America - European Union Association Agreement: an assessment using general and partial equilibrium

Includes bibliography.

América Latina y la Conferencia Mundial de Población = Latin America and the World Population Conference

Incluye Bibliografía

Criticisms and suggestions on the cross-conditionality of the IMF and the World Bank

Includes bibliography

First World and Third World after the cold war

Includes bibliography

Latin American development problems and the world economic crisis

Includes bibliography

Services: a disquieting link between Latin America and the world economy

Includes bibliography

Latin American supply and major world market demand for the principal metals, 1970-1990: aluminium, copper, iron, nickel, lead, zinc, tin

Includes bibliography

Los problemas del desarrollo latinoamericano y la crisis de la economía mundial = Latin American development problems and the world economic crisis

Incluye Bibliografía

El desarrollo del transporte público urbano en América Latina y el mundo = The development of urban public transport in Latin America and the world

Incluye Bibliografía