On axial temperature gradients due to large pressure drops in dense fluid chromatography.

The effect of energy degradation (Degradation is the creation of net entropy resulting from irreversibility.) accompanying pressure drops across chromatographic columns is examined with regard to explaining axial temperature gradients in both high performance liquid chromatography (HPLC) and supercritical fluid chromatography (SFC). The observed effects of warming and cooling can be explained equally well in the language of thermodynamics or fluid dynamics.

Data acquisition in a high-speed rotating frame for New Mexico Institute of Mining and Technology liquid sodium αω dynamo experiment.

New Mexico Institute of Mining and Technology liquid sodium αω-dynamo experiment models the magnetic field generation in the universe as discussed in detail by Colgate, Li, and Pariev [Phys. Plasmas 8, 2425 (2001)]. To obtain a quasi-laminar flow with magnetic Reynolds number R(m) ~ 120, the dynamo experiment consists of two co-axial cylinders of 30.

High magnetic shear gain in a liquid sodium stable Couette flow experiment: a prelude to an α-Ω dynamo.

The Ω phase of the liquid sodium α-Ω dynamo experiment at New Mexico Institute of Mining and Technology in cooperation with Los Alamos National Laboratory has demonstrated a high toroidal field B(ϕ) that is ≃8×B(r), where B(r) is the radial component of an applied poloidal magnetic field. This enhanced toroidal field is produced by the rotational shear in stable Couette flow within liquid sodium at a magnetic Reynolds number Rm≃120. Small turbulence in stable Taylor-Couette flow is caused by Ekman flow at the end walls, which causes an estimated turbulence energy fraction of (δv/v)(2)∼10(-3).

Risk behavior-based model of the cubic growth of acquired immunodeficiency syndrome in the United States.

The cumulative number of cases of acquired immunodeficiency syndrome (AIDS) in the United States has grown as the cube of time rather than exponentially. We explain this by interactions involving partner choice and sexual frequency in a risk-behavior model with biased mixing. This leads to a saturation wave of infection moving from high- to low-risk groups.

The need for national HIV databases.

Researchers and public health officials involved in surveying and forecasting the course of the HIV epidemic require complete and unfiltered information from many sources. Governments should respond by establishing national HIV databases.

SIT vidicon with magnetic intensifier for astronomical use.

We have coupled a magnetic intensifier to an intensified silicon target vidicon. The output and controls are digital and designed to optimize the computer analysis of the astronomical data. A coarse sweep 128 x 128 lines gives a large ( approximately 10:1) pixel to pixel modulation.

Tornadoes: mechanism and control.

If electrical energy is invoked to account for the high velocity of tornadoes, hydrodynamics restricts the possible mechanisms of energy exchange. In particular, the vortex is driven by a line sink of electrically heated air that must extend at least 5 kilometers high. In those rare cases where heroic measures may be justified to protect a city in the path of a major tornado, some possible control measures are discussed in terms of the electrical heating mechanism.