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In this work, DC & RF magnetron sputtering and COMSOL multiphysics were used to simulate and deposit WO3 and WO3/Ag films, respectively. In the simulation cyclic voltammetry (CV) analysis was examined. The current density for the WO3/Ag films in comparison to the WO3 film was displayed higher. Based on the simulation findings, the experiment was done using DC & RF magnetron sputtering to deposit WO3 and WO3/Ag films. Scanning electron microscopy (SEM), X-ray diffraction (XRD), UV–vis spectrometer, and electrochemical analyzer were used to examine the structural, morphological, EC, and optical characteristics of the deposited films. The SEM study revealed a smooth surface for WO3 films and WO3/Ag shows the grain of silver film. The XRD analysis of WO3 films shows the amorphous nature and in WO3/Ag films silver peaks were shown. The bandgap values were found to be 3.14 eV and 3.02 eV for WO3 and WO3/Ag films, respectively. Comparing the WO3/Ag film to the WO3 film, the cyclic voltammograms showed that the WO3/Ag film had the maximum current. In comparison to the WO3 film (30 cm2C−1), higher coloring efficiency values were noted for the WO3/Ag film (48 cm2C−1). For the WO3/Ag film, less time is needed for the coloring (tc = 2.2) and belching (tb = 1.8 s). It was clear that compared to a single-component WO3 film, the Ag-embedded WO3 composite system performed noticeably better electroactively and electrochemically. [ABSTRACT FROM AUTHOR]

The sol–gel auto-combustion method was used to prepared 5Zn0.4Cd0.1Fe2-xSmxO4 (x = 0.0, 0.02, 0.04, 0.06, and 0.08) doped with rare earth Sm3+. To adjust the structural, DC electrical resistivity, and magnetic characteristics of the spinel ferrites, rare earth Sm3+ was doped. As a result, using X-ray diffraction (XRD), field effect scanning electron microscopy (FESEM), Fourier transformation infrared spectroscopy (FTIR), two-probe technique, and vibrating sample magnetometer (VSM), respectively, researchers investigated the systematic impact of Sm3+ on the structural, morphological, DC resistivity, and magnetic studies. The synthesized materials' ability to form a single-phase nanostructure was confirmed by XRD investigation. Images captured by field effect scanning electron microscopy show that all samples exhibit spherical nanocrystalline activity. Spinel formation was verified using Fourier transform infrared spectroscopy (FTIR). NiZnCd ferrite's magnetic properties are examined to Sm3+ doping using vivid sample magnetometry spectra. Coercivity values and saturation magnetization decrease due to the increased Sm3+ doping. Data on saturation magnetization, coercivity, and remanence magnetization were obtained from the Sm3+ doping of NiZnCd micro ferrites. These results suggest that the device may find use in magnetic recording and memory applications. A two-probe approach is used to measure the DC electrical resistivity, which reveals the semiconducting nature. The carrier concentration and activation energy were found using data on DC electrical resistivity and were subsequently linked to Sm3+ replacement. The DC electrical resistivity testing of the prepared ferrite samples was conducted using a standard two-probe method. [ABSTRACT FROM AUTHOR]

In this study, Co–Cu–Zn–Cr nano ferrites with a composition of Co0.5Cu0.25Zn0.25Fe2-xCrxO4 (x = 0.0, 0.05, 0.1, 0.15, 0.2, and 0.25) are prepared by sol–gel auto combustion method. These doped nanocrystalline ferrites’ characteristics were examined using X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), field emission scanning electron microscopy (FESEM), and vibratory sample magnetometer (VSM). Such analytical characterizations were done for the structural and magnetic investigations. The crystallographic structure was identified using X-ray diffraction, which showed that a single-phase cubic spinel structure has been formed. According to the Debye–Scherrer equation, the synthesized samples’ average crystallite diameters ranged from 55.32 to 33.41 nm. Field emission scanning electron microscopy (FE-SEM) was used to study the surface morphology of the particles, revealing aggregated grains with a sponge-like structure. Functional groups were detected using Fourier transform infrared (FTIR) spectroscopy; peaks at about 393.21–582.71 cm−1 and 392.74–381.50 cm−1 indicated specific chemical properties. Magnetic characteristics at room temperature were investigated using a vibrating sample magnetometer (VSM), revealing some magnetic parameters. Hysteresis curves demonstrate reduced coercivity (263.98 to 126.62 Oe) and saturation magnetization (43.72 to 63.29 emu/g) upon metal ion replacement in the Co–Cu–Zn nano ferrites. [ABSTRACT FROM AUTHOR]

A survey of environmental gamma radiation levels is attempted in the geographical site under construction to establish a petrochemical industry. The knowledge of natural background radiation is one of the significant steps in establishing the chemical industry. Some chemical operations such as chemical refinement may sometimes influence the natural radiation levels. The attempt of measurement of natural background gamma levels in the present paper is to establish the baseline data, which on further measurements will be useful to analyse the changes in natural background radiation levels at the time of operation of a chemical plant. The present investigation shows the activity levels of gamma radiation in the site under construction at 65 locations. The gamma levels are found to vary from 1459 µGyy-1 to 2765 µGyy-1 with the average of 2141±304 µGyy-1. It is to be noted from the study that the average gamma radiation levels at two sample locations, cement mixing point (2307 µGyy-1) and stone crushing point (2529 µGyy-1) have been elevated. The elevated radiation levels at the two sample locations can be attributed to the radioactive dust emitted in the process of crushing stones and cement mixing. [ABSTRACT FROM AUTHOR]

It is well known that cobalt exhibits polymorphism, i.e., the co-existence of both the hcp and fcc phases. In particular, the method of synthesis and other thermodynamic conditions is known to play a crucial role in determining the particular phase of cobalt. In this work, we have compared the phase composition of the cobalt nanoparticles synthesized using two different solvents (water) and ethanol (Co@C). XRD measurements confirm the existence of fcc phase in commercial cobalt nanoparticles (Co@A), co-existence of fcc and hcp phases in Co@B, while the existence of the hcp phase in Co@C. We have studied these cobalt nanoparticles using 59Co internal field nuclear magnetic resonance (IFNMR) for verification of phase composition. Our studies reveal that the Co@A has fcc as a major phase with minor quantity hcp phase. Co@B exhibits approximately equal amount of fcc and hcp phase while Co@C exhibits hcp as a major phase with minor fcc phase. Our SEM micrograph studies confirm that the cobalt particles have spherical shape in the fcc phase. The cobalt particles exhibit both spherical and dendrite morphology confirming the co-existence of fcc and hcp phases, while the sample with pure hcp phase exhibits the dendrite morphology. Our studies also throw light on understanding the effect of solvent in the phase formation of the cobalt nanoparticles. [ABSTRACT FROM AUTHOR]

The effect of A-site substitution of Ce3+ in tungsten bronze structured PBN ceramics with the general formula, Pb( x − 3 y/2)Ce y Ba(1 − x)Nb2O6 and the stoichiometric chemical formula, Pb(0.65 − 3 y/2)Ce y Ba0.35Nb2O6, where y = 0, 2, 4, 6, 8 and 10 mol% ceramic compositions synthesized through solid state reaction method are reported. The X-ray diffraction studies exhibited the presence of an orthorhombic phase, and its intensity increased with the increasing Ce3+ content up to y = 6 mol% or A3 composition. The lattice parameters, unit cell volume and density as a function of Ce3+ concentration are discussed. It is observed that increasing Ce3+ content in A-site influenced the dielectric properties. The optimum dielectric properties of room temperature dielectric constant (εRT) and dielectric maximum ( $$ \varepsilon {T} _{{\text{c}}} $$ ) are observed in y = 6 mol% or A3 composition while Curie temperature ( T c) and dielectric loss (tan δ) constantly decreased from undoped to y = 10 mol%, and thus A3 composition or 6 mol% Ce modified tungsten bronze structured-PBN could be suitable for capacitor applications. [ABSTRACT FROM AUTHOR]

Background & objectives: COVID-19 has been a global pandemic since early 2020. It has diverse clinical manifestations, but consistent immunological and metabolic correlates of disease severity and protection are not clear. This study was undertaken to compare seropositivity rate, antibody levels against nucleocapsid and spike proteins, virus neutralization and metabolites between adult and child COVID-19 patients. Methods: Plasma samples from naïve control (n=14) and reverse transcription (RT)-PCR positive COVID-19 participants (n=132) were tested for reactivity with nucleocapsid and spike proteins by ELISA, neutralization of SARS-CoV-2 infectivity in Vero cells and metabolites by 1H nuclear magnetic resonance (NMR) spectroscopy. Results: An ELISA platform was developed using nucleocapsid and spike proteins for COVID-19 serosurvey. The participants showed greater seropositivity for nucleocapsid (72%) than spike (55.3%), and males showed higher seropositivity than females for both the proteins. Antibody levels to both the proteins were higher in intensive care unit (ICU) than ward patients. Children showed lower seropositivity and antibody levels than adults. In contrast to ICU adults (81.3%), ICU children (33.3%) showed lower seropositivity for spike. Notably, the neutralization efficiency correlated with levels of antinucleocapsid antibodies. The levels of plasma metabolites were perturbed differentially in COVID-19 patients as compared with the naive controls. Interpretation & conclusions: Our results reflect the complexity of human immune response and metabolome to SARS-CoV-2 infection. While innate and cellular immune responses are likely to be a major determinant of disease severity and protection, antibodies to multiple viral proteins likely affect COVID-19 pathogenesis. In children, not adults, lower seropositivity rate for spike was associated with disease severity. [ABSTRACT FROM AUTHOR]