Using macroscopic thermodynamics, the general law for adiabatic processes carried out by an ideal gas was studied. It was shown that the process reversibility is characterized by the adiabatic reversibility coefficient r, in the range 0 [less than or equal] r [less than or equal] 1 for expansions and r [greater than or equal] 1 for compressions.…

In this paper we analyse the behaviour of a small-scale model of a magnetic levitation system based on the Inductrack concept. Drag and lift forces acting on our prototype, moving above a continuous copper track, are studied analytically following a simple low-speed approach. The experimental results are in good agreement with the theoretical…

Dialogue and illustrations trace the history of the first peoples of South, Central, and North America and encourage students to look at past and present patterns of colonialism and to view colonialism from the perspective of the colonized. Chapter 1 critiques Columbus 500 years after founding the first colony in the Americas. Chapter 2 presents…