Comparative catching efficiency of traditional prawn fishing gears in Pulicat lake of Tamil Nadu, India

303-310Prawn fishery in Pulicat Lake has a significant role in livelihood of the fishers, which is being harvested through different fishing gears. Here, we investigated the prawn-fishing gear and their catch composition. The information on various aspect about the gears was collected from the 48 respondents each month through pre-designed interview schedule by adopting random sampling. Results revealed that the quantity of prawn were higher in stake net (209.83 kg), followed by barriers (118.58 kg), drive-in-net (55.58 kg) tangle net (18.25 kg) and was statically significant at 5 %. It was estimated that more than half (52.16 %) of the total prawn catch in Pulicat Lake was obtained through stake net than the barriers (29.48 %), drive-in-net (13.82 %) and tangle net (4.54 %). The maximum quantity of prawn was obtained during the November and December in all the prawn-fishing gear (p < 0.05). This study concludes that non-selective fishing gears resulted in the abundant catch of juvenile fishes and crabs, need to be regulated mesh size, to support the conservation and sustainable harvest of the fishery resources in Pulicat Lake

Synthesis of porous CuCo2O4 nanorods/reduced graphene oxide composites via a facile microwave hydrothermal method for high-performance hybrid supercapacitor applications

Supercapacitors are considered to be promising energy storage devices because of their long cycle stability, fast charge-discharge, and high power density. However, energy storage performance predominantly depends on the morphology and nanostructure of electrode materials. The material with porous nanostructures has attracted great interest because of more active sites for the faradaic reactions which facilitate the utilization of the full capacity of the active materials. Herein, porous CuCo2O4 (CCO) nanorods dispersed on reduced graphene oxide (rGO) nanosheets (CCO/rGO) has been prepared in a short duration via a facile single-step microwave hydrothermal method. The porous feature of the CCO nanorod provides more reactive sites for faradaic reaction and facilitates the electrolyte penetration into the inner region of the electrode. Also, the incorporation of rGO provides a more conductive network that facilitates the collection and transportation of electrons during cycling. Electrochemical performance of the CCO/rGO composite exhibits a specific capacity of 677 C g(-1) at a current density of 1 A g(-1) and retained excellent cycling stability of 97.4% after 2000 cycles at a high current density of 10 A g(-1). This work demonstrated a simple, effective, and cost-cut method to prepare porous CuCo2O4 on rGO electrodes in a short time duration with the enhanced electrochemical performance for hybrid supercapacitor applications. (C) 2021 Elsevier Ltd. All rights reserved

Heterostructure CuO/Co₃O₄ Nanocomposite: An Efficient Electrode for Supercapacitor and Electrocatalyst for Oxygen Evolution Reaction Applications

Earth-abundant transition metal oxides (TMOs) are promising electroactive materials for electrochemical energy conversion and storage applications due to their high theoretical specific capacity, enhanced electrocatalytic activity, and mechanical durability. However, the limited cycle stability and low conductivity of TMOs remain challenging for practical application. Herein, we developed a TMO-based nanocomposite of CuO/Co3O4 via precipitation followed by the microwave hydrothermal method and used as a bifunctional electroactive material for supercapacitor and oxygen evolution reaction (OER) applications. The CuO/Co3O4 nanocomposite electrode exhibits a high specific capacity of 586 C g–1 and an excellent cyclic reversibility of 113.6% under a high current density of 20 A g–1 after 5000 cycles. Apart from the high redox properties, the strong synergistic interaction between CuO and Co3O4 significantly enhances the electrocatalytic property of the material. On continuous electrolysis in 1 M KOH solution, the OER electrode fabricated with CuO/Co3O4 nanocomposite demonstrated a moderate overpotential (ηO2) of 270 mV at j = 10 mA cm–2, a slight Tafel slope of 54 mV dec–1, and significant OER stability. These results highlight the fabrication of high-performance TMOs-based CuO/Co3O4 nanocomposite and their utilization in electrochemical energy storage and conversion devices for attaining maximum efficiency