The Photoexcited carrier lifetime (τ) and peak to valley transmission difference (ΔTp-v) in direct and indirect band gap crystals has been investigated by the use of single beam open and closed aperture z-scan technique using frequency doubled Nd:YAG laser. The peak to valley transmission difference (ΔTp-v) is found to be of the order of 10-2 in case of direct band gap crystals and of the order...

the use of temporary runoff and underground dried-up water courses has been implemented by managers in recentyears to compensate for water shortages in arid and semi-arid regions. one way to use this water is to set up anunderground sandy dam in front of such water courses; selecting a suitable water course is the most important issue ofsuch a purpose. in the present research, this matter was i...

We have developed a compact microbeam radiation therapy device using carbon nanotube cathodes to create a linear array of narrow focal line segments on a tungsten anode and a custom collimator assembly to select a slice of the resulting wedge-shaped radiation pattern. Effective focal line width was measured to be 131 μm, resulting in a microbeam width of ∼300 μm. The instantaneous dose rate was...

Landscapes have been shown to exhibit numerous scaling laws from Horton's laws to more sophisticated scaling in topography heights, river network topology and power laws in several geomorphic attributes. In this paper, we propose a different way of examining landscape organization by introducing the “river corridor width” (lateral distance from the centerline of the river to the left and right ...

introduction the fanuj titaniferous placer deposits are located 35 km northwest of the fanuj, sistan and baluchestan province (1) . the studied area comprises a (2) small part of the late cretaceous fanuj-maskutan (rameshk) ophiolite complex (arshadi and mahdavi, 1987). reconnaissance and comprehensive exploration programs in the fanuj district (east of the 1:100000 fanuj quadrangle map,yazdi, ...

Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. The MIT Faculty has made this article openly available. Please share how this access benefits you. Your story matters. [1] After completing a 9-month field experiment studying air pollution and meteorology in the Kathmandu Valley, Nep...

The non-classical distribution function formalism is used for studying the electron transport in a nanosystem. We calculated the current–voltage characteristics of a triple barrier one-dimensional nanostructure which is connected to three-dimensional (highly doped semiconductor) reservoirs by the ohmic contacts. We also estimated the peak-to-valley ratio for the considered nanostructure and dis...