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Polyurethane composites synthesized by interaction of fly ash filler with polyether polyol, cross-linking agent, and curing agent in a certain ratio. The study's findings show that the mechanical properties of polyurethane composite are lowered by the hydroxyl moieties of surface-functionalized fly ash that are chemically or physically linked. The study also reveals that prior subjecting the samples of surface-functionalized fly ash–reinforced polyurethane composite material for destructive analysis by UTM for evaluating mechanical properties. The in-depth study of the IR spectroscopy data of the composites is done focusing onto the stretching frequency of carbonyl group of carbamate links the trend in mechanical behavior of the samples, the number of fly ash–carbamate links, and proximity of HS–SS (hard segment–soft segment) of fly ash–reinforced polyurethane composites can be foretold. By a detailed analysis of the patterns of carbonyl stretching frequencies of carbamate links, one can gain insight into the microphasic level of the separation and proximity of hard and soft segments in composites, which govern their mechanical properties. The relationships between carbamate carbonyl stretching frequencies and mechanical characteristics of composites have been found to be inversely correlated. In order to offset the excess hydroxyl group contribution due to OH-loaded fly ash, as indicated by the isocyanate (NCO) peak intensity (2,240–2,280 cm−1) in the composite's infrared spectra, the studies were conducted at a higher index ratio (1.64). [ABSTRACT FROM AUTHOR]

Although extensive work has already been done on bulk La1−xSr1+xCoO4 layered oxides, there is very limited studies on their nano-crystalline nature, particularly for those with a higher Sr level (x ≥ 0.4), which may exhibit interesting magnetic properties and in particular photocatalytic properties because of their enhanced surface area. Moreover, the phases with higher Sr doping levels can be formed only at higher temperatures, which otherwise contain significant amounts of impurities. In order to synthesize them in a nanocrystalline form in the pure state at the lowest possible temperature, we applied a glycine nitrate combustion method using excess fuels for the synthesis of nanocrystalline La1−xSr1+xCoO4 (x = 0.0, 0.2, 0.4 and 0.6) layered perovskite oxides. Efforts were also made to synthesize phases with x > 0.6 but remained unsuccessful. The prepared nanophases were thoroughly characterized using PXRD, XPS, SEM, SQUID VSM and UV-DRS to examine the structural, morphological, optical, magnetic and photocatalytic properties. All the phases exhibit mixed valence states of +3 and +4 of Co, as confirmed by XPS analysis, which has a remarkable effect on various physical properties, especially magnetic and photocatalytic properties. An abrupt transition in magnetic behaviour from antiferromagnetic for x = 0 and 0.2 phases to ferromagnetic in case of x = 0.4 and 0.6 was observed. The optical band gap values (Eg) of all the synthesized nanophases obtained from DRS are in the visible range (1.57 to 1.47 eV), which make them suitable and reliable photocatalysts for dye degradation. Moreover, the synthesized nanophases were assessed for their photocatalytic activity by employing rhodamine B (RhB) dye as a model contaminant. The results revealed that the La0.4Sr1.6CoO4 photocatalyst efficiently and swiftly degraded RhB within 60 min. Considering the performance of the La0.4Sr1.6CoO4 photocatalyst, the study was expanded to include the degradation of other organic dye pollutants, namely, methyl orange (MO), methylene blue (MB) and a ternary combination of these contaminants (RhB + MB + MO). [ABSTRACT FROM AUTHOR]

Hydraulic fracturing is one of the industrial processes behind the surging natural gas output in the United States. This technology inadvertently creates an engineered microbial ecosystem thousands of meters below Earth's surface. Here, we used laboratory reactors to perform manipulations of persisting shale microbial communities that are currently not feasible in field scenarios. Metaproteomic and metabolite findings from the laboratory were then corroborated using regression-based modeling performed on metagenomic and metabolite data from more than 40 produced fluids from five hydraulically fractured shale wells. Collectively, our findings show that Halanaerobium, Geotoga, and Methanohalophilus strain abundances predict a significant fraction of nitrogen and carbon metabolites in the field. Our laboratory findings also exposed cryptic predatory, cooperative, and competitive interactions that impact microorganisms across fractured shales. Scaling these results from the laboratory to the field identified mechanisms underpinning biogeochemical reactions, yielding knowledge that can be harnessed to potentially increase energy yields and inform management practices in hydraulically fractured shales.