A thermal lattice Boltzmann model for micro/nano-flows

The dynamic behavior of charged micro and nanofluids plays a crucial role in a large variety of industrial and biological processes. Such dynamic behavior is characterized by the simultaneous occurrence of several competing mechanisms, such as electrostatic interactions, viscous dissipation and hydrodynamic effects, often taking place in complex geometries. This paper focuses on a thermal lattice Boltzmann model for micro/nano-flows

Health Plan Quality: Factors Influencing Hospital Participation in Health Plans

The professional and popular literatures are full of reports of surveys and studies purporting to rate health plans. Health maintenance organizations and other organizations are surveying member satisfaction. Accreditation of health plans is receiving increased attention. Interest is growing in plans\u27 performance in the areas measured by the Health Plan Employers\u27 Data and Information Set (HEDIS). The factors measured in current ratings and accreditation systems are not important to hospitals for evaluating health plan participation. There are factors in a health plan\u27s performance that are important to and either beneficial or detrimental to hospitals. This paper proposes factors upon which health care plans should be evaluated and rated to measure their business partner quality from the hospital perspective

Fish as Pollutants: Limitations of and Crosscurrents in Law, Science, Management, and Policy

When we think of pollutants, we either consciously or unconsciously draw a bright line between pollutants and what might be called natural. That which is natural cannot be a pollutant; that which is a pollutant cannot be natural. It seems odd to speak of live fish as pollutants, as odd as it would be to speak of dioxins as natural. Nevertheless, the traditional definition of fish as natural may be fading as our awareness of the adverse environmental effects of accidental or poorly planned fish introductions increases. Along these lines, a federal court recently found that non-native Atlantic salmon that escape from their pens are pollutants within the meaning of the Clean Water Act. Because wild Atlantic salmon is listed as an Endangered Species, Salmon mariculture provides a particularly stark example of when society might aptly consider fish to be pollutants. The biological, philosophical, and legal underpinning of our argument, however, transcends aquaculture into the realm of fisheries management, where we advocate that managers focus on improving water quality to the point where the native fish that historically were dominant in the habitat are once again abundant, rather than on managing aquatic ecosystems for stocked species of fish that are relatively unaffected by degraded water quality

Effects of rarefaction on cavity flow in the slip regime

The Navier-Stokes-Fourier equations, with boundary conditions that account for the effects of velocity-slip and temperature-jump, are compared to the direct simulation Monte Carlo method for the case of a lid-driven micro-cavity. Results are presented for Knudsen numbers within the slip-flow regime where the onset of nonequilibrium effects are usually observed. Good agreement is found in predicting the general features of the velocity field and the recirculating flow. However, although the steady-state pressure distributions along the walls of the driven cavity are generally in good agreement with the Monte Carlo data, there is some indication that the results are starting to show noticeable differences, particularly at the separation and reattachment points. The modified Navier-Stokes-Fourier equations consistently overpredict the maximum and minimum pressure values throughout the slip regime. This highlights the need for alternative boundary formulations or modeling techniques that can provide accurate and computationally economic solutions over a wider range of Knudsen numbers

Micro-scale cavities in the slip - and transition - flow regimes

Differences between Navier-Stokes-Fourier (NSF) slip/jump solutions and direct simulation Monte-Carlo (DSMC) computations are highlighted for a micro lid-driven cavity problem. The results indicate a need for better modelling techniques which at the same time retain low computational cost of NSF models. We also highlight the fact thatmany micro-flows that have been considered are simple planar flows and typical classification systems are defined on such flows. We show that for complex flows, such as thedriven cavity, non-equilibrium effects are more appreciable and their onset occurs at lower Knudsen numbers than expected

Low-field magnetoresistance in granular Pb films near the insulator-superconductor transition

We have studied the insulator-superconductor transition in quench-condensed granular Pb films from 0.1 to 10 K. Resistance measurements were made in zero magnetic field and low noise conditions. Magnetoresistance measurements were also performed for low magnetic fields (less than 100 G). The magnetoresistance results on the superconducting side of the transition suggest that we are directly probing the finite length scales associated with the range of phase coherence in these granular materials