We report high-resolution (0.05 cm(-1)) FTIR spectra of the fundamental and first overtone of the amide I mode of trans-N-methylacetamide (NMA) trapped in solid molecular hydrogen (SMH) at cryogenic temperatures with low (0.03%) and high (55%) ortho-hydrogen (oH(2)) concentrations. NMA-doped SMH samples with high oH(2) concentrations are nearly free from inhomogeneous broadening, permitting the measured amide I homogeneous line width of 1.268(8) cm(-1) to be used to place a lower limit on the vibrational lifetime of 4.19(3) ps. Direct observation of the amide I overtone allows the harmonic vibrational frequency ω(e) = 1726.6(5) cm(-1) and the anharmonicity constant ω(e)x(e) = 8.5(2) cm(-1) to be determined for NMA isolated in SMH samples with low oH(2) concentrations.
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Vadose Zone J
May 2024
Groundwater Characterization and Remediation Division, US Environmental Protection Agency, Ada, Oklahoma, USA.
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December 2024
Hebei Key Laboratory of Water Quality Engineering and Comprehensive Utilization of Water Resources, Hebei University of Architecture, Zhangjiakou 075000, China.
Qingshui River is a vital source for human life and industrial production in Zhangjiakou City. Determination of the formation mechanism of the main hydrochemical ions is important for the sustainable development and utilization of surface water resources in the Qingshui River. In view of this, 20 surface water samples were collected from the agricultural and urban reaches of the Qingshui River in July 2022.
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November 2024
Key Laboratory of Aquatic Botany and Watershed Ecology, Wuhan Botanical Garden, Chinese Academy of Sciences, Wuhan, 430074, China.
The high levels of nitrate (NO) in the surface water have contributed to eutrophication and other eco-environmental damages worldwide. Although the excessive NO concentrations in rivers were often attributed to anthropogenic activities, some undisturbed or slightly disturbed rivers also had high NO levels. This study utilized multi-pronged approaches (i.
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Department of Chemical and Biochemical Engineering, National Technological Institute of Mexico (TecNM)-Durango Institute of Technology (ITD), Blvd. Felipe Pescador 1830, Nueva Vizcaya, Durango 34080, Mexico.
Molecular dynamics (MD) techniques offer significant potential for optimizing mineral extraction processes by simulating economically or physically restrictive conditions at the laboratory level. Lithium, a crucial metal in the electromobility era, exemplifies the need for ongoing re-evaluation of extraction techniques. This research aims to simulate the crystal structures of mineral species present in a polylithionite mineral concentrate [KLiAl(SiO)(F,OH)] using crystallographic data obtained from X-ray diffraction analysis.
View Article and Find Full Text PDFSci Rep
November 2024
Department of Endodontics, Faculty of Dentistry, Suez Canal University, Ismailia, Egypt.
Different Streptococcal species including Streptococcus mutans, Streptococcus sobrinus and Enterococcus faecalis are commonly isolated in root canal infections including refractory, recurrent, and persistent cases. Calcium hydroxide (Ca (OH)) has been widely used in endodontics as an intracanal medicament. However, using new antimicrobial herbal alternatives offers promising potentials which can be additionally enhanced by using nanoparticles (NPs).
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