Farming organic vegetable and crops have grown as a market desiring commodity. Weed control in farms has been costly and laborous and it has always been hard to achieve a proper weeding. A few chemicals are commonly applied in organic farming. Thermal weeding with flame burners seems a good solution; however, it has its own drawbacks, such as; damaging the main crops, low performance, being inf...

Steady state natural convection is numerically investigated in an enclosure using variable thermal conductivity, viscosity and thermal expansion coefficient of Al2O3–water nanofluid. This study has been conducted for a wide range of Rayleigh numbers (103≤ Ra ≤ 106), concentrations of nanoparticles (0% ≤ Φ ≤ 7%), enclosure aspect ratios (0.5 ≤ AR ≤ 2) and temperature differences between the cold...

This paper introduces a simple variable gain amplifier (VGA) structure that shows an inherently dB-linear gain control property. Requiring no additional components for dB-linear control, the structure is compact and power efficient. The designed two-stage VGA shows a gain control range of 60dB with the gain error in the range of ±0.4 dB. The power consumption including the output buffer is 20.4...