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In this work, we present the validation of the chemical method for total reflection X-ray fluorescence (TXRF) analysis of water, proposed as a standard to the International Standard Organization. The complete experimental procedure to define the linear calibration range, elements sensitivities, limits of detection and quantification, precision and accuracy is presented for a commercial TXRF spectrometer equipped with Mo X-ray tube. Least squares linear regression, including all statistical tests is performed separately for each element of interest to extract sensitivities. Relative sensitivities with respect to Ga, as internal standard, are calculated. Accuracy and precision of the quantification procedure using Ga as internal standard is evaluated with reference water samples. A detailed discussion on the calibration procedure and the limitation of the use of this method for quantitative analysis of water is presented.
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http://dx.doi.org/10.1016/j.talanta.2017.12.087 | DOI Listing |
Water Res
September 2025
College of Hydrology and Water Resources, Hohai University, Nanjing 210098, China. Electronic address:
Groundwater overextraction presents persistent challenges due to strategic interdependence among decentralized users. While game-theoretic models have advanced the analysis of individual incentives and collective outcomes, most frameworks assume fully rational agents and neglect the role of cognitive and social factors. This study proposes a coupled model that integrates opinion dynamics with a differential game of groundwater extraction, capturing the interaction between institutional authority and evolving stakeholder preferences.
View Article and Find Full Text PDFACS Appl Mater Interfaces
September 2025
The Steve Sanghi College of Engineering, Mechanical Engineering, Northern Arizona University, Flagstaff, Arizona 86011, United States.
This study investigates the HO and CO sorption behavior of two chemically distinct polystyrene-divinylbenzene-based ion exchange sorbents: a primary amine and a permanently charged strong base quaternary ammonium (QA) group with (bi)carbonate counter anions. We compare their distinct interactions with HO and CO through simultaneous thermal gravimetric, calorimetric, gas analysis, and molecular modeling approaches to evaluate their performance for dilute CO separations like direct air capture. Thermal and hybrid (heat + low-temperature hydration) desorption experiments demonstrate that the QA-based sorbent binds both water and CO more strongly than the amine counterparts but undergoes degradation at moderate temperatures, limiting its compatibility with thermal swing regeneration.
View Article and Find Full Text PDFJ Phys Chem A
September 2025
Dipartimento di Scienze Fisiche e Chimiche, Università degli Studi dell'Aquila, Coppito, L'Aquila 67100, Italy.
In recent years Quantum Computing prominently entered in the field of Computational Chemistry, importing and transforming computational methods and ideas originally developed within other disciplines, such as Physics, Mathematics and Computer Science into algorithms able to estimate quantum properties of atoms and molecules on present and future quantum devices. An important role in this contamination process is attributed to Quantum Information techniques, having the 2-fold role of contributing to the analysis of electron correlation and entanglements and guiding the construction of wave function variational ansatzes for the Variational Quantum Eigensolver technique. This paper introduces the tool SparQ (Sparse Quantum state analysis), designed to efficiently compute fundamental quantum information theory observables on post-Hartree-Fock wave functions sparse in their definition space.
View Article and Find Full Text PDFPLoS Negl Trop Dis
September 2025
Department of Clinical Science, Liverpool School of Tropical Medicine, Liverpool, United Kingdom.
Background: Salmonella enterica encompasses over 2,600 serovars, including several commonly associated with severe infection in humans. Salmonella is a major cause of sepsis in Africa; however, diagnosis requires clinical microbiology facilities. Environmental surveillance has the potential to play a role in Salmonella surveillance.
View Article and Find Full Text PDFPLoS One
September 2025
Department of Social Science, Malawi Liverpool Wellcome Clinical Programme, Blantyre, Malawi.
Diarrhoea due to rotavirus remains a significant cause of child mortality in developing regions. Caregivers' perspectives on the social determinants of gastroenteritis and childhood vaccination, including the rotavirus vaccine, were explored through focus group discussions in Ethiopia (n = 6), Kenya (n = 14), and Malawi (n = 10), using a combination of thematic and framework analysis approaches. The results show that diarrhoea was perceived to be a burden in all three countries, particularly among infants, due to challenges in WASH (water, sanitation, and hygiene) infrastructures and poverty.
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