The p-i-n carbon nanotube (CNT) devices suffer from low ON/OFF current ratio and small saturation current. In this paper by band bending engineering, we improved the device performance of p-i-n CNT field effect transistors (CNTFET). A triple gate all around structure is proposed to manage the carrier transport along the channel. We called this structure multi-segment gate (MSG) CNTFET. Band to ...

In recent decades, many dams have been built or are under construction. Due to the high demand for water and soil erosion, increasing the need for dam construction in different regions are quite tangible. In 1900 the number of large dams, did not exceed 50. But in the 1950s to 1986 the number of large dams (over 15 meters), more than 39,000 were counted. The 70s dams has been increasing develop...

The modeling of broad crested weirs is expected to facilitate understanding, especially the behavior flow flowing through measuring instrument. under consideration hydraulic behavior, measurement accuracy, and discharge curve. In addition, there a relationship between water level upstream downstream spillway, as well variation loss energy height. From results this study, it was found that upstr...

Recently the stepped spillways have been used as an appropriate solution for energy dissipation. In the present study, Siahbisheh dam spillway is simulated by using Computational Fluid Dynamic (CFD), in which the Mixture method and Reynolds Stresses Model (RSM) turbulence model is used. In the first modeling series the over all steppes slope is constant. The number of the steps is increased to ...

In this research, the numerical method of computational fluid dynamics and dimensionless parameter of Froude number have been applied to determine the flow regime over ogee spillways.Froude number is a dimensionless dynamic parameter calculated using the square root of the ratio of inertia force and gravitational force. Considering that the study of the regimes of flow over hydraulic structures...

Changes in flood loads and reservoir levels, produced by climate change (CC), represent an increasing concern for dam safety managers downstream populations, highlighting the need to define adaptation strategies based on failure risk management framework. Currently, thousands of dams worldwide, varying use, age, maintenance, may a threat cities case structural failure. Several studies relate se...

Diyala Governorate was exposed recently to high flood waves discharged from Hemrin Dam River when the dam reached its full capacity. The recorded discharge capacity of reduced just 750m3/s. This exposes cities and villages along risk discharging waves, which may reach 3000 m3/s. It is important manage, suggest, design escapes away River. escape branches Lake towards Ashweicha Marsh. One dimensi...

Among the many force s to which hydraulic structures are exposed to, the forces induced by cavitation incident are of typical hydrodynamic unknown forces. The aim of this study is to define these forces as coupled fluid-structure interaction under two dynamic effects. The first dynamic effect which incorporates facilities for dealing with cavitation fluid is based on the appearance and bursting...