In corporate networks, idle desktop machines hardly ever sleep, mainly for the reason that turning off the hosts will affect the internet connection. There are number of systems have been proposed, few of them have mutually considered energy consumption and performance. In this article, we consider the case of file downloading, which is one of the most common internet applications. A system cal...

In this letter I compare two measures of energy quality, energy return on energy invested (EROI) and energy intensity ratio (EIR) for the fossil fuel consumption and production of the United States. All other characteristics being equal, a fuel or energy system with a higher EROI or EIR is of better quality because more energy is provided to society. I define and calculate the EIR for oil, natu...