For computing the magnetic shielding in solids, density functional theory as implemented in a plane wave basis has proven to be a reasonably accurate and efficient framework, at least for lighter atoms through the third row of the periodic table. In materials with heavier atoms, terms not usually included in the electronic Hamiltonian can become significant, limiting accuracy. Here we derive and implement the zeroth-order regular approximation (ZORA) relativistic terms in the presence of both external magnetic fields and internal nuclear magnetic dipoles, to derive the ZORA-corrected magnetic shielding in the context of periodic boundary conditions and a plane wave basis.
View Article and Find Full Text PDFGroundwater flow and contaminant migration tracing is a vital method of identifying and characterising pollutant source-pathway-receptor linkages in karst aquifers. Bacteriophages are an attractive alternative tracer to non-reactive fluorescent dye tracers, as high titres (>10 pfu mL) can be safely released into the aquifer, offering improved tracer detectability. However, the interpretation of bacteriophage tracer breakthrough curves is complicated as their fate and transport are impacted by aquifer physicochemical conditions.
View Article and Find Full Text PDFThe developmental activities of 328 elite soccer players aged under-16 years from Brazil, England, France, Ghana, Mexico, Portugal and Sweden were examined using retrospective recall in a cross-sectional research design. The activities were compared to the early diversification, early specialisation, and early engagement pathways. Players started their involvement in soccer at approximately 5 years of age.
View Article and Find Full Text PDFThe fair innings argument maintains that for healthcare resources to be distributed fairly every person should receive sufficient healthcare to provide them with the opportunity to live in good health for a normal span of years. What constitutes a normal span of years is often defined as life expectancy at birth, but this criterion fails to provide adequate grounds for the equal distribution of healthcare across and between generations. A more suitable criterion for the normal life span is the idea that the human life span is biologically limited.
View Article and Find Full Text PDFThis study looks at the chemical composition of traditional eye cosmetics ("kohls") used in Qatar and Yemen. Of especial interest was how many samples in each country contain the toxic element lead. In Qatar 19 observably different kohl samples were obtained, and in Yemen ten such samples obtained.
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