Biomedical subjects

Robert A Jackson

Publications and source records attributed to Robert A Jackson.

3 recordsLinked to original sources

PubMed2005

Who's not afraid of Proposal B? An analysis of exit-poll data from Michigan's vote on physician-assisted suicide.

In November 1998, Michigan voters rejected Proposal B, a citizen initiative that would have legalized physician-assisted suicide (PAS). Although polls had long indicated overwhelming support for PAS, support for Proposal B declined before the election. We analyzed exit-poll data to characterize opponents, supporters, and cross-over voters. We then compared our results with those from earlier research that examined attitudinal and socio-demographic influences. We found that many presumptive PAS supporters did not vote for Proposal B. These data may call into question prospects for similar initiatives.

Data Collection↗

PubMed2004

Lanthanide transport in stabilized zirconias: interrelation between ionic radius and diffusion coefficient.

The diffusion of all stable lanthanides was measured both in calcia stabilized zirconia (CSZ) and in yttria stabilized zirconia (YSZ) in the temperature range between 1,286 and 1,600 degrees C. The lanthanide diffusion coefficients obtained increase with increasing ionic radius. The experimental activation enthalpy of diffusion is near 6 eV for CSZ and between 4 and 5 eV for YSZ and is not strongly affected by the type of lanthanide. The results were correlated with defect energy calculations of the lanthanide diffusion enthalpy using the Mott-Littleton approach. An association enthalpy of cation vacancies with oxygen vacancies of about 1 eV (96 kJ/mol) was deduced in the case of CSZ, while there is no association in the case of YSZ. Furthermore, the change in diffusion coefficients can be correlated to the interaction parameter for the interaction between the lanthanide oxide with zirconia: The higher the interaction parameter, the higher the lanthanide diffusion coefficient.

Journal Article↗

PubMed2004

Computer modelling of mixed metal fluorides for optical applications.

This paper describes a new computational method for predicting the optical behaviour of doped inorganic materials. There is considerable interest in using inorganic materials in photonic devices, and in many cases, the optical properties of these materials depend on doping by ions such as those from the rare earth series. Among the inorganic materials of interest are the mixed metal fluorides (e.g. BaLiF(3), BaY(2)F(8), YLiF(4), LiCaAlF(6), LiSrAlF(6)), doped with trivalent rare earth ions. The paper describes the use of Mott-Littleton calculations to determine the optimum location for dopant ions, followed by crystal field calculations which make direct use of the output of the Mott-Littleton calculations to calculate the optical properties of the dopant ion taking into account its symmetry and the positions of the surrounding ions, including any vacancies or interstitial ions present by virtue of charge compensation. It is then possible to predict whether a given dopant ion at a particular site in a material will have favourable optical properties.

Journal Article↗