No abstract

DC–DC converters have wide applications in industries, motor drive circuits, electric vehicles, and power supplies. In traditional converters hard switching occurs due to switching losses. This imposes constraints on the converter’s efficiency which results in heat dissipation and reduction in the converter’s life. The proposed converter aims to encounter the hard switching problem with the provision of soft switching features. The presented topology is efficient with respect to the features of cost, compact size and durable lifetime of converter topology with the provision of low switching stresses. This research work proposes a novel stepdown converter with zero voltage switching characteristics. With the use of half bridge inverter switches and series resonant components in the auxiliary circuit, the target of zero voltage switching and reduction in switching stresses has been achieved. The proposed 500 W converter is designed to operate at frequency of 100 KHz with 300 V source input voltage. Output voltage of the converter is 150 V.

Herbicides are widely used to kill weeds and increase crop production all over the world. Nevertheless, some weeds show certain structural modifications in response to herbicide application that impart mostly partial or sometimes complete tolerance to these noxious plants. The present study was focused on morpho-anatomical modifications in the root, stem, and leaves of Dactyloctenium aegyptium (L.) Willd. treated with different herbicides and to examine whether it possesses tolerance against herbicides. Two pre- and four post-emergence herbicides were applied to D. aegyptium at the recommended dose in a randomized complete block design (RCBD). Pre-emergence herbicide Bromoxynil enhanced root growth (30%), leaves per plant (3%), and leaf fresh weight (17.2%). Increased stem epidermal thickness (100%) was the most notable feature among anatomical attributes. Post-emergence herbicides generally increased stem epidermal thickness 33–56%), leaf sheath thickness (5%), and root area in roots. Other modifications included increased sclerenchymatous thickness in the stem (133–255%), and epidermal thickness (100–200%) in the leaf blade. These characters assisted D. aegyptium to cope with herbicide toxicity. Collectively, pre-emergence herbicides more effectively controlled D. aegyptium compared with post-emergence herbicides.