Optimization of P& PI controller parameters for variable speed drive systems using a flower pollination algorithm.

In this study, a novel flower pollination algorithm (FPA) has been suggested for optimal tuning of P and PI controllers included in a variable speed drive VSD system control circuit. In addition to the manual tuning of controllers' parameters, several optimization algorithms like GA, PSO, GWO have been used for controllers optimal tuning in different studies. In this study, the errors caused by grid side current harmonic distortion in the VSD system have been used depending on SPWM technique to generate switching signals for a four-quadrant chopper circuit that acts like a filter and compensates the harmonic content in the grid current and smooth ripples in both DC-link current and voltage.

Carbofuran-induced endocrine disruption in adult male rats.

The objective of this investigation was to determine the acute toxic effects of the carbamate insecticide carbofuran on the levels of endocrine hormones in the serum of male Sprague-Dawley rats. Using chemiluminescent immunoassay, the hormones determined were progesterone, cortisol, estradiol, testosterone, triidothyronine (T3), total thyroxine (total T4), and non-protein-bound thyroxine (free T4). Rats exposed to an acute dose of carbofuran (1.

Cadmium uptake by radishes from soil contaminated with nickel-cadmium batteries: toxicity and safety considerations.

The objective of this investigation was twofold: (1) to determine the contamination of soil by cadmium (Cd) from commonly used nickel-cadmium (Ni-Cd) batteries utilized in electronic devices and (2) to determine the uptake of Cd in common garden radishes. Under normal controlled conditions, the study utilized depleted batteries; new, undamaged batteries; and new, damaged batteries. The data revealed that the contamination of the soil by Cd was significantly greater in the presence of new, damaged batteries than in the presence of the new, undamaged batteries or depleted batteries.