boron nitride semiconducting zigzag swcnt, $b_{cb}$$n_{cn}$$c_{1-cb-cn}$, as a potential candidate for making nanoelectronic devices was examined. in contrast to the previous dft calculations, wherein just one boron and nitrogen doping configuration have been considered, here for the average over all possible configurations, density of states (dos) was calculated in terms of boron and nitrogen ...

flow in natural river bends is a complex and turbulent phenomenon which affects the scour and sedimentations and causes an irregular bed topography on the bed. for the reason, the flow hydralics and the parameters which affect the flow to be studied and understand. in this study the effect of bed and wall roughness using the software fluent discussed in a sharp 90-degree flume bend with 40.3cm ...

This study was conducted in oak forests of Ilam province in order to evaluate the morphological characteristics of old trees including diameter at breast height, trunk height, whole tree height, minimum and maximum crown diameter, crown health, crown vitality, crown symmetry, health and form of the trunk, Was investigated. Selection of old trees was performed based on the criteria of DBH and wi...

1. to determine whether difference in birth body mass influenced growth performance in pipistrellus kuhlii we studied a total of 12 captive-born neonates. bats were assigned to two body mass groups: light birth body mass (lbw: 0.89 ± 0.05, n=8) and heavy birth body mass (hbw: 1.35 ± 0.08, n=4). heavier body mass at birth was associated with rapid postnatal growth (body mass and forearm length) ...

The current research is based on the existing ecological conditions in the Zagros forests and knowledge of the response of forest trees to these conditions and the purpose of this study is to investigate the effect of topographic factors, tree characteristics on of fine roots biomass of gal oak (Quercus infectoria Oliv.) and also to compare the amount of nitrogen, phosphorus and potassium in th...