regarding the role and importance of subsurface drainage in water table control, many studies have been made throughout the world to find out new techniques and more economical solutions, especially as related to different pipe envelope material and their installations. this research was conducted to investigate the use of rice husk, as drain envelope material, in drainage installations. in add...

due to the important role of subsurface drainage in managing the ground water level, there are many researches focused on finding a new and more economic way to develop subsurface drainage technologies. lack of proper drainage system in northern iran has caused huge implantation of rice and it is impossible to have second implantation in this region. one reason of insufficiency of current drain...

in this research, the appropriateness of drainmod-n model was evaluated for the simulation of nitrate transport with subsurface drainage in paddy fields. during a canola growing season from november 2011 to april 2012, the nitrate concentration of drainage water and soil saturation extracts of two depths of 30 and 60 cm was measured in consolidated paddy fields of sari agricultural sciences and...

abstract a previous study on agricultural drains in khuzestan province of iran has indicated that carbonate calcium is the main component of the deposited salts in drainage envelops. to investigate the process of precipitation of carbonate calcium under different conditions including chemical, bio-chemical, aerobic and an-aerobic, a through laboratory investigation on geotextile drain envelop w...

Subsurface drainage is an important agriculture measure. It primary to select suitable drain pipes and envelopes for efficient subsurface drainage. And now, corrugated drains geotextile are widely used. However, the effects of perforations on not well understood. This study conducted a series sand tank experiments steady-state flow with or without different perforation patterns. The profile hea...

In this paper, we propose a new heterostructure dual material gate junctionless field-effect transistor (H-DMG-JLFET), with negative differential resistance (NDR) characteristic. The drain and channel material are silicon and source material is germanium. The gate electrode near the source is larger. A dual gate material technique is used to achieve upward band bending in order to access n-i-p-...

This paper revisits usual passive bias networks for microwave power amplifiers (PA), considering not only their effects on PA stability, but also its suitability to be used in drain modulated amplifiers. Some technical limitations and challenges regarding the design of PA in structures based on envelope tracking techniques, such as Polar Transmitters or Envelope Elimination and Restoration (EER...

Static X-parameter (XP) models for RF power amplifiers (PAs), derived from both simulations and nonlinear vector network analyzer (NVNA) measurements, are investigated for the prediction of PA performance under dynamic signal conditions such as in envelope tracking (ET). The instantaneous AM-AM, AM-PM and PAE predictions of XP models extracted from simulation are compared under ET dynamic signa...

The class-E amplifier [1]-[11] is remarked as the next candidate of digital wireless power transmitters. Non-switching power amplifiers suffer from low power-conversion efficiency due to their inherent power loss in high back off area. Hence, switching power amplifiers such as class-D and E are remarked as a remedy for improving power-conversion efficiency and prolonging battery lifetime of por...