Low energy muonic hydrogen reactions with heavy atoms

Average s-wave cross-sections appropriate for liquid hydrogen temperatures are calculated with the aid of an in-coming wave boundary condition for the muon transfer process μ^-p + Z → (μ^-Z)¹ + p on heavy atoms. The surface-correlated nature of the heavy atom X-rays is emphasized.     

Erratum to: Determination of metal ion content of beverages and estimation of target hazard quotients: a comparative study

This is a correction to the following paper: Hague T, Petroczi A, Andrews PR, Barker J, Naughton DP: Determination of metal ion content of beverages and estimation of target hazard quotients: a comparative study. Chem Central J 2008, 2:13.     

Sputtering by fast electrons

Calculations are presented of collision cascade and knockon contributions to sputtering induced by fast electrons. The sputtering yield for MeV electrons bombarding carbon and iron is found to be ≈10^?7 to 10^?6. Important erosion effects on astrophysical grains are possible.     

On the simplified pair-copula construction — Simply useful or too simplistic?

Due to their high flexibility, yet simple structure, pair-copula constructions (PCCs) are becoming increasingly popular for constructing continuous multivariate distributions. However, inference requires the simplifying assumption that all the pair-copulae depend on the conditioning variables merely through the two conditional distribution functions that constitute their arguments, and not directly. In terms of standard measures of dependence, we express conditions under which a specific pair-copula decomposition of a multivariate distribution is of this simplified form. Moreover, we show that the simplified PCC in fact is a rather good approximation, even when the simplifying assumption is far from being fulfilled by the actual model.     

Determination of metal ion content of beverages and estimation of target hazard quotients: a comparative study

Background  

Considerable research has been directed towards the roles of metal ions in nutrition with metal ion toxicity attracting particular attention. The aim of this study is to measure the levels of metal ions found in selected beverages (red wine, stout and apple juice) and to determine their potential detrimental effects via calculation of the Target Hazard Quotients (THQ) for 250 mL daily consumption.     

Negative muon capture in very light atoms

The transition rates for unbound muons to be captured into atomic bound states are calculated as functions of (1) incident muon center-of-mass energy, (2) muon principal quantum number n, and (3) muon (final) angular momentum l, for the hydrogen, helium, and lithium atoms. These rates reflect differences in electron binding energies. At muon energies of several hundred electron volts, lithium K-shell electrons are more likely to be ejected than the L-shell electron, while this behavior is reversed for energies ? 10 eV. However, in each case when the capture rate is folded with a muon stopping power function, the result is that more than half of the unbound muons are absorbed above 75 eV. Implications for experiments which look at muon transfer processes are noted.