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Cobalt Oxide (Co 3 O 4 ) nanoparticles were synthesized with an aid of urea by sol–gel method. The results of X-ray diffraction revealed that the formation of face-centered cubic (Fd3m) structure and the average crystallite size of the product were found to be 13.76 nm. The formation of cobalt oxide is confirmed by FT-IR analysis. The results of HR-TEM images reveal that Co 3 O 4 nanoparticles were found to have within the range of 13–15 nm. At 3 M KOH, electrochemical analyses were investigated with impedance spectroscopy and an intrinsic pseudo capacitance and the results were reported. The results of Galvanostatic charge-discharge (GCD) tests revealed the capacitive properties of Co 3 O 4 with the highest specific capacitance of 761.25 F g −1 . Highlights The specific capacitance of Co 3 O 4 nanoparticles was found to be 761.25 F g −1 at 11 mA/cm 2 current density. The Co 3 O 4 nanoparticles were synthesized by a simple sol–gel method. The crystallite size of Co 3 O 4 nanoparticles was found to be 13.76 nm.

Ammonia gas sensors that work at room temperature are of immediate requirement to monitor the environmental safety of human beings and other living organisms. In the present study, we report the room temperature ammonia-sensing performances of Co 3 O 4 and NiCo 2 O 4 nanoparticles. The hydrothermally prepared samples were characterized using various sophisticated techniques in order to investigate the crystal structure, phase purity, morphology, elemental and chemical composition. The as prepared samples displayed selectivity against the ammonia gas and the NiCo 2 O 4 nanorod-like sample exhibited superior sensing performances at room temperature.

This research work emphasizes on the development of a unique high-gain BOCUK DC-DC converter for Switched Mode Power Supply (SMPS) applications. The high-gain BOOST-CUK (BOCUK) DC-DC converter combines the benefits of both Boost and Cuk converters for attaining instantaneous line current shaping and load regulation. The proposed BOCUK converter provides a non-inverted output and improves the voltage gain and efficiency. The modes of operation of the high-gain BOCUK DC-DC Converter in a Continuous Conduction Mode (CCM) with parasitic elements in the circuit are examined and a state-space model is constructed. The second-order model is derived using the Modified Hankel Matrix Method (HMM) to make the controller design easier. Dual-loop Control employing an inner Linear Quadratic Regulator (LQR) current Controller and an outer Atom Search Optimization (ASO)-tuned Proportional Integral (PI) controller is used to analyze the performance indices of the high-gain converter and fluctuations in line, load and setpoint are investigated. Simulation results prove that the LQR controller is robust in tracking the load voltage and provides excellent line current shaping with low % Total Harmonic Distortion (THD) and nearly Unity Power Factor (UPF). The hardware model for 200W is built and implemented using the TMS320F28027F microcontroller to verify the simulation results.

SrTiO 3 /Ag nanocomposites were synthesized using a facile wet impregnation method, employing rigorous experimental techniques for comprehensive characterization. XRD, FTIR, UV, PL, FESEM, and HRTEM were meticulously utilized to elucidate their structural, functional, morphological, and optical properties. The electrochemical performance of the SrTiO 3 /Ag nanocomposite was rigorously assessed, revealing an impressive specific capacitance of 850 F/g at a current density of 1 A. Furthermore, the photocatalytic activity of the SrTiO 3 /Ag nanocomposite was rigorously examined using methylene blue (MB) dye, and the results were outstanding. After 120 min of UV irradiation, the nanocomposite exhibited an exceptional MB dye degradation efficiency exceeding 88%. The SrTiO 3 /Ag nanocomposite represents an exemplary catalyst in terms of efficiency, cost-effectiveness, environmental compatibility, and reusability. The electron and superoxide radicals play a chief role in the MB dye degradation process. The inclusion of Ag within the SrTiO 3 matrix facilitated the formation of a conductive nano-network, ultimately resulting in superior capacitive and photocatalytic performance.

A simple sol–gel combustion process was employed for the creation of MFe 2 O 4 (M=Ni, Co) nanoparticles. The synthesized nanoparticles, acting as both photocatalysts and gas sensors, were analyzed using various analytical techniques. MFe 2 O 4 (M=Ni, Co) material improved the degradation of methylene blue (MB) under UV-light irradiation, serving as an enhanced electron transport medium. UV–vis studies demonstrated that NiFe 2 O 4 achieved a 60% degradation, while CoFe 2 O 4 nanostructure exhibited a 76% degradation efficacy in the MB dye removal process. Furthermore, MFe 2 O 4 (M=Ni, Co) demonstrated chemosensitive-type sensor capabilities at ambient temperature. The sensor response and recovery times for CoFe 2 O 4 at a concentration of 100 ppm were 15 and 20, respectively. Overall, the synthesis of MFe 2 O 4 (M=Ni, Co) holds the potential to significantly improve the photocatalytic and gas sensing properties, particularly enhancing the performance of CoFe 2 O 4 . The observed enhancements make honey MFe 2 O 4 (M=Ni, Co) a preferable choice for environmental remediation applications.

Nanoferrites with chemical formulae of CuFe 2 O 4 (CFO), Mn 0.5 Cu 0.5 Fe 2 O 4 (MCFO), and Mn 0.5 Cu 0.5 Sm x Fe 2− x O 4 (SMCFO) were synthesized by the sonochemical method as substrate material for microstrip patch antennas. The structural, oxidation, and vibrational characteristics of the nanoferrite substrate were analyzed through X-ray diffraction, X-ray photoelectron, and infrared spectroscopy. The lattice constant of the CFO nanoferrite is 8.413 Å, whereas that of MCFO is 8.429 Å, which is smaller than that of SMCFO nanoferrite. The spherical morphology of the nanoferrite substrate was observed through field-emission scanning electron microscopy images. The magnetic properties of the pristine and Sm 3+ -doped Mn 0.5 Cu 0.5 Fe 2 O 4 nanoferrites were studied using a vibrating sample magnetometer. The dielectric permittivity ( ε r ) and dielectric loss tangent (tan δ e ) of the prepared nanoferrites were used as substrate to design the microstrip patch antenna by simulation using a high-frequency structure simulator. The R L value of the simulated microstrip patch antennas was in the range of − 17.80 to − 46.28 dB at a frequency of 25 GHz. The voltage standing wave ratio values of the simulated microstrip patch antenna were between 0.08 and 2.41. Thus, it was concluded that the prepared materials can play an important role in developing flexible substrates for antennas in 5G mobile application.

This paper has proposed a hybrid seven-level inverter topology with a boosting capability three times that of conventional seven-level inverter topologies. It contains ten number of active switches and an internal flying capacitor unit that develops a composition like the combination of T-type and neutral point clamped (NPC) inverter topologies. The proposed inverter topology increases dc link voltage utilization and reduces the total standing voltages across the power switches. In addition, self-voltage balancing of the floating capacitor is achieved through a simple level shifted PWM modulation technique. The dc link requirement of the proposed inverter topology is reduced by 66% when compared to the conventional seven-level inverters, and it can be more useful in industrial applications, including grid-tied renewable generation units. The working methodology and steady state analysis of the topology are presented, and its operation is validated through the simulation results performed in both Matlab/Simulink and PSIM platforms. In addition, experimental results verify the proposed inverter topology.

Social grooming is conspicuous in group-living mammals. Bats are gregarious and may groom each other, but the motivation for such social behaviour remains unclear. Here, we describe patterns and infer function of social grooming in tent-making Indian short-nosed fruit bats. Combining field and captivity observations, we found that males and their harem of females mutually groom and apply bodily secretions to one another in tight clusters. Mutual grooming is more commonly initiated by females, before emergence flight at dusk, and during the non-mating season. The within-harem association pattern suggests males may recognize female reproductive status via social grooming. Chemical analysis of the secretions applied during grooming revealed volatile organic compounds that may be involved in chemosensory-mediated communication and/or mate choice. These fruit bat harems were previously seen as simple aggregations, with limited interactions among individuals. Our findings suggest social grooming is multi-functional, with potential implications for the bats' social lives.

A simple solvothermal method for the selective synthesis of β-HgS (meta cinnabar) nanoparticles in aqueous solutions is reported with bis(dibenzyldithiocarbamato)mercury(II) as the precursor. Crystal structure, size, morphology and composition of the products are characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX) analysis, high-resolution transmission electron microscopy (HRTEM), SAED and X-ray photoelectron spectroscopy (XPS). PXRD shows (111), (220), (200), (311), (222), (400), (331), (420) reflections characteristic of β-HgS. SEM micrographs display the spherical nature of the nano-β-HgS. EDX analysis showed the presence of Hg and S. HRTEM images indicate the spherical nature of the nanoparticles with their size in the range of 10–15 nm and the FFT pattern shows the crystalline nature of the spherical particles. The results are in agreement with those estimated from the XRD pattern. XPS signals observed at 162.6 and 162.8 eV are due to S2 p 3/2 and S2 p 1/2 electrons and the S2 s was observed at 222.3 eV. The band gap of nano-β-HgS has been found to be 3.6 eV from the UV–visible spectral measurement. The blue-shifted band gap compared to the bulk HgS is a consequence of “size quantization” effect. A comprehensive characterization of the precursor by IR and single crystal X-ray crystallography shows the presence of HgS 4 coordination environment, with a distinct Hg–S bond asymmetry.