Viscosity and Thermal Relaxation for a resonantly interacting Fermi gas

The viscous and thermal relaxation rates of an interacting fermion gas are calculated as functions of temperature and scattering length, using a many-body scattering matrix which incorporates medium effects due to Fermi blocking of intermediate states. These effects are demonstrated to be large close to the transition temperature $T_c$ to the superfluid state. For a homogeneous gas in the unitarity limit, the relaxation rates are increased by nearly an order of magnitude compared to their value obtained in the absence of medium effects due to the Cooper instability at $T_c$. For trapped gases the corresponding ratio is found to be about three due to the averaging over the inhomogeneous density distribution. The effect of superfluidity below $T_c$ is considered to leading order in the ratio between the energy gap and the transition temperature.Comment: 7 pages, 3 figure

Frequency and damping of the Scissors Mode of a Fermi gas

We calculate the frequency and damping of the scissors mode in a classical gas as a function of temperature and coupling strength. Our results show good agreement with the main features observed in recent measurements of the scissors mode in an ultracold gas of $^6$Li atoms. The comparison between theory and experiment involves no fitting parameters and thus allows an identification of non-classical effects at and near the unitarity limit.Comment: 4 pages, 2 figure

Covalent bonding of antibodies of polystyrene latex beads: A concept

Technique facilitates purification of vaccines and production of immunoadsorption columns exhibiting relatively long stability. Information interests biochemists, medical researchers, and pharmaceutical manufacturers

Viscous relaxation and collective oscillations in a trapped Fermi gas near the unitarity limit

The viscous relaxation time of a trapped two-component gas of fermions in its normal phase is calculated as a function of temperature and scattering length, with the collision probability being determined by an energy-dependent s-wave cross section. The result is used for calculating the temperature dependence of the frequency and damping of collective modes studied in recent experiments, starting from the kinetic equation for the fermion distribution function with mean-field effects included in the streaming terms.Comment: 10 pages, 9 figures; proof version, corrected typo in Eq. (23); accepted for publication in PR

Latino Destinations and Environmental Inequality: Estimated Cancer Risk from Air Toxics in Latino Traditional and New Destinations

Since the 1990s, Latino migration patterns have shifted from traditional destinations to new destinations away from the Mexico border. Scholars note disparities between destinations in housing, crime, and health care, yet no study has examined environmental inequalities. In this article we employ theories of spatial assimilation and environmental inequality to evaluate health risks across Latino destinations by asking the question, is there a difference in estimated cancer risk from air toxics among established, new, and nondestination locations? Using county-level data with spatial lag regression analyses, we find that early new destinations (i.e., counties with significant Latino growth from 1990 to 2000) and recent new destinations (i.e., counties with significant Latino growth from 1990 to 2010) have higher estimated cancer risk from air toxics than established destinations (i.e., counties at or greater than the national average of Latinos in 1990) and nondestinations. The effect remains significant when controlling for various economic indicators

Pulse transit time: a new approach to haemodynamic monitoring in obstetric spinal anaesthesia

Part of the Portfolio Thesis by Geoffrey H. Sharwood-Smith: The inferior vena caval compression theory of hypotension in obstetric spinal anaesthesia: studies in normal and preeclamptic pregnancy, a literature review and revision of fundamental concepts, available at http://hdl.handle.net/10023/1815Original abstract presented at the Obstetric Anaesthetisits' Association congress 2002, Nottingham, 9-10 May.Postprin

Molecular oxygen densities from rocket measurements of Lyman-alpha absorption profiles

Molecular oxygen density measurements in upper atmosphere by absorption spectroscopy using solar Lyman alpha radiatio