Exact semi-relativistic model for ionization of atomic hydrogen by electron impact

We present a semi-relativistic model for the description of the ionization process of atomic hydrogen by electron impact in the first Born approximation by using the Darwin wave function to describe the bound state of atomic hydrogen and the Sommerfeld-Maue wave function to describe the ejected electron. This model, accurate to first order in $Z/c$ in the relativistic correction, shows that, even at low kinetic energies of the incident electron, spin effects are small but not negligible. These effects become noticeable with increasing incident electron energies. All analytical calculations are exact and our semi-relativistic results are compared with the results obtained in the non relativistic Coulomb Born Approximation both for the coplanar asymmetric and the binary coplanar geometries.Comment: 8 pages, 6 figures, Revte

The Forensic Characterization of Bacterial and Fungal Organisms in Traditional Chinese Medicine

There has been an increase in use of Traditional Chinese Medicine (TCM) in the United States because they are less expensive and believed to be more effective with less adverse effects in comparison to traditional pharmaceutics. Therefore, sales have increased in the US, despite articles and case studies demonstrating the dangers, such as injury and death, related to TCM, stemming from improper labelling, toxic contaminants, and, in some cases, the presence of pathogenic bacteria. The aim of this study was to perform a survival experiment to demonstrate the importance of proper herbal brewing technique and to conduct a molecular and biochemical survey of microorganisms present on eleven Chinese herbal samples. The survival study compared Chinese brewing preparation and American brewing preparation by fortifying the herbal mixture with known bacteria and assessing its survival after brewing. The American brewed herbal tea was calculated to contain upwards of 3000 CFU (colony forming units)/mL, where the Chinese brewed herbal tea contained roughly 50 CFU/mL. FAME (Fatty Acid Methyl Ester) analysis was performed on the herbs to characterize any microorganisms present on the plant material already, following purchase. Strains within the Bacillus genus were identified in nearly all eleven of the herbal samples. These included B. subtilis and B. megaterium. Organisms belonging to the Bacillus ACT group (anthracis, cereus, thuringiensis) were identified in five out of eleven herb cultures as evidenced by the large ratio of 15:0 iso to 15:0 anteiso fatty acid biomarkers. Nine out of eleven herbal specimens also exhibited fungal biomarkers such as polyunsaturated 20:4 ω6,9,12,15c, and 18:3 ω6c (6,9,12).https://scholarscompass.vcu.edu/uresposters/1291/thumbnail.jp