Showing 2 results for D-T
M. Sheikhan and M. E. Kalantari,
Volume 27, Issue 1 (7-2008)
Abstract
This paper tries to estimate the capital investment required for the fixed-telephony network switching equipment as demanded by the fourth national development plan. As a first step, the Cobb-Douglas model is used as a successful demand forecasting model to estimate the demand over the target years. Then, an architectural plan is developed for the fixed-telephony switching network that takes into account the expansion of the existing exchanges as well as the addition of new ones. The number of the required ports in local exchanges, the intercity traffic (including cell phone subscribers), and the required trunks in transit exchanges are then estimated. Two scenarios are used to estimate the investment needed: expanding legacy network (circuit-based), and NGN adoption (a combination of circuit and packet-based networks). Finally, conventional pricelists from different local and foreign suppliers are used to arrive at two total investment estimates: 6,013 billion Rials and 6330 billion Rials for the two mentioned scenarios, respectively.
A. Parvazian and S. R. Hoseini Dalasm,
Volume 27, Issue 1 (7-2008)
Abstract
In recent years, many different plans have been considered to use the nuclear energy gained from inertial confinement fusion (ICF) as attempts to obtain high energy efficiencies. In conventional ICF methods, a small amount (about mg) of the deuterium–tritium compound is confined in a small spherical chamber of a few millimeters in radius and compressed by laser or heavy ion beams with powers in the order of W. The consequent plasma froming at the center of the chamber is an essential issue for fusion. The hydrodynamical instabilities during the fuel compression process arising in the conventional ICF technique leads to a decline in energy efficiency. The new plans for reducing instabilities involve compression of the fuel chamber in two stages using laser or ion beams. In the first stage, fuel is preheated by laser or ion and in the second phase, relativistic electrons are constructed by -W laser phases in the fuel. This heating method has come to be known as a fast “ignition method”. More recently, cylindrical rather than spherical fuel chambers with magnetic control in the plasma domain have been also considered. In this work, fast ignition method in cylindrical fuel chambers will be investigated and transportation of the relativistic electrons will be calculated using MCNP code and the Fokker–Planck program. Furthermore, the transfer rate of relativistic electron energy to the fuel will be calculated. Our calculations show that the fast ignition method and cylindrical chambers guarantee a higher energy efficiency than the one-step ignition and that it can be considered an appropriate substitute for the current ICF techniques.
