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Abstract Mn3O4 nanograins incorporated into reduced graphene oxide as a nanocomposite electrocatalyst have been synthesized via one-step, facile, and single-pot microwave-assisted hydrothermal technique. The nanocomposites were employed as cathode material of fuel cells for oxygen reduction reaction (ORR). The synthesized product was thoroughly studied by using important characterization, such as XRD for the structure analysis and FESEM and TEM analyses to assess the morphological structures of the material. Raman spectra were employed to study the GO, rGO bands and formation of Mn3O4@rGO nanocomposite. FTIR and UV–Vis spectroscopic analysis were used to verify the effective synthesis of the desired electrocatalyst. The Mn3O4@rGO-10% nanocomposite with 10 wt% of graphene oxide was used to alter the shiny surface of the working electrode and applied for ORR in O2 purged 0.5 M KOH electrolyte solution. The Mn3O4@rGO-10% nanocomposite electrocatalyst exhibited outstanding performance with an improved current of − 0.738 mA/cm2 and shifted overpotential values of − 0.345 V when compared to other controlled electrodes, including the conventionally used Pt/C catalyst generally used for ORR activity. The tolerance of Mn3O4@rGO-10% nanocomposite was tested by injecting a higher concentration of methanol, i.e., 0.5 M, and found unsusceptible by methanol crossover. The stability test of the synthesized electrocatalyst after 3000 s was also considered, and it demonstrated excellent current retention of 98% compared to commercially available Pt/C electrocatalyst. The synthesized nanocomposite material could be regarded as an effective and Pt-free electrocatalyst for practical ORR that meets the requirement of low cost, facile fabrication, and adequate stability.

DFT studies are performed to investigate the crystal structure and geometry, electronic and magnetic properties of brownmillerite-type strontium-based oxygen-deficient perovskites SrTMO2.5 (TM = Mn, Fe, Co and Cu) in orthorhombic phase. The comparison of the calculated lattice parameters shows consistency with the experiments, and all these perovskites are thermodynamically stable as revealed by cohesive energy. The spin-dependent calculations of the electronic band profiles demonstrate the metallic behavior of all these deficient perovskites. The increase in electrical resistivity and electronic thermal conductivities with temperature also confirms the metallic behavior of these compounds. The optimized ground state energies in different magnetic phases and post-DFT treatment confirm that SrMnO2.5 and SrCoO2.5 are stable in C-type AFM, SrFeO2.5 is in G-type AFM and SrCuO2.5 in A-type AFM phase, respectively. The high specific heat of these deficient perovskites makes them good candidates for high-temperature technology. Based on the above physical properties, it is expected that these deficient perovskites are potential candidates for spintronics and magnetic storage devices. [ABSTRACT FROM AUTHOR]

Simple Summary: This research examined how light exposure during incubation affects broiler chickens after hatch. Incubating eggs were exposed to different light durations during incubation (from none to all the time). After hatching, chicks' growth, stress levels, health, and immune response were checked. Results show that light during incubation did not affect most of these measures; however, chicks exposed to 20 h of light had heavier hearts. Overall, light during incubation does not seem to have a big impact on post-hatch performance. This study evaluated the subsequent effect of photoperiods during incubation on post-hatch growth and stress response of commercial broiler chickens. A total of 875 Ross 308 broiler breeder (48 weeks of age) eggs were hatched using different durations (0, 4, 8, 12, 16, 20, and 24 h a day) of dichromatic light [green and red (495 to 750 nm); 2700 K; 250 lux; SUNJIE; China] throughout the whole period of incubation. A total of 50 0-day-old hatched straight run broiler chicks from each photoperiod during incubation were used to evaluate subsequent growth performance (feed intake, body weight, and feed conversion ratio); stress parameters (physical asymmetry, tonic immobility, and vocalization,); welfare traits (feather score and gait score); carcass traits (live weight, dressed weight, carcass yield, liver weight, gizzard weight, heart weight, abdominal fat weight, breast weight, and leg weight); and serum chemistry (globulin, total protein, cholesterol, glucose, and uric acid). There were no influences of photoperiod during incubation on post-hatch growth, stress parameters, welfare, and carcass traits. Heart yield was higher in birds incubated under 20 h light than in those from the 16 h light group. Incubation under different lighting durations also altered blood biochemical profile but did not influence serum globulin and cholesterol levels. It was concluded that under experimental conditions, incubation of broiler eggs under different lighting durations did not impact subsequent post-hatch performance (21–35 d). [ABSTRACT FROM AUTHOR]