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Copper oxide (CuO) nanostructures have gained significance due to their chemical and physical properties that find applications in sensing, electronics and minimizing solar background count in spaceborne plasma instruments. In this work, a wet-chemical route has been utilized to synthesize nanostructured CuO coating on aluminum alloy substrates. The coating was thoroughly characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive x-ray spectroscopy (EDX), Raman spectroscopy, glow-discharge optical emission spectroscopy (GDOES), UV-VIS-NIR spectrophotometer and four probe resistance methods. XRD results showed diffraction peaks corresponding to CuO while SEM micrograph depicted a floral-like nanostructure. Raman spectrum revealed phonon vibrational modes corresponding to CuO. The average solar absorptance of CuO nanostructure was 96% in the wavelength range of 0.25-2.5 μm. A comparison of the UV-induced photoelectron counts between the bare substrate and coated samples showed reduction by a factor of 107 due to the presence of CuO nanostructures. The CuO nanostructures also exhibited excellent electrical conductivity and low-degassing properties. Finally, space worthiness studies of the coating in simulated space environments was carried out and proven to be space qualified. [ABSTRACT FROM AUTHOR]

The present work explores the adaptive behavior of well-known ureolytic bacterial strain namely Sporosarcina pasteurii for microbial-induced calcite precipitation (MICP) under saline environment. MICP activity was observed up to 10% NaCl supplementation and confirmed by several characterization techniques viz. scanning electron microscopy (SEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA). The urease activity did not show appreciable decline till 5% NaCl supplementation but beyond that drastic reduction was observed though MICP process continued. These results indicated a shift in the biological pathway for MICP process at higher salt concentrations. This was confirmed by estimation of ammonium ion concentration which was approximately 4 µg/ml with 10% NaCl supplementation as compared to 8.5 µg/ml at 0% NaCl supplementation. To provide an insight on the nature of protein expressed, combination of liquid chromatography-mass spectrometry (nano-LC-MS) approaches along with an exponentially modified protein abundance index (emPAI) methodology were explored. The findings suggest the presence of significant number of osmoregulatory proteins substantiating halophilic adaptation of S. pasteurii and bicarbonate transport mediated precipitation at higher levels of salinity. Further, co-precipitation of CaCl2 and MgSO4 was also confirmed with SEM and energy dispersive spectroscopy (EDS) mapping under higher saline environment thus substantiating the efficacy of the strain. [ABSTRACT FROM AUTHOR]

Vanadium oxide films, deposited on aluminium (Al), titanium (Ti) and tantalum (Ta) metal substrates by pulsed RF magnetron sputtering at a working pressure of 1.5 x10−2 mbar at room temperature are found to display mixed crystalline vanadium oxide phases viz., VO2, V2O3, V2O5. The films have been characterized by field-emission scanning electron microscopy, X-ray diffraction, differential scanning calorimetry (DSC) and X-ray photoelectron spectroscopy, and their thermo-optical and electrical properties have been investigated. Studies of the deposited films by DSC have revealed a reversible-phase transition found in the temperature range of 45–49 °C. [ABSTRACT FROM AUTHOR]