Results of magnetospheric barium ion cloud experiment of 1971

The barium ion cloud experiment involved the release of about 2 kg of barium at an altitude of 31 482 km, a latitude of 6.926 N., and a longitude of 74.395 W. Significant erosion of plasma from the main ion core occurred during the initial phase of the ion cloud expansion. From the motion of the outermost striational filaments, the electric field components were determined to be 0.19 mV/m in the westerly direction and 0.68 mV/m in the inward direction. The differences between these components and those measured from balloons flown in the proximity of the extremity of the field line through the release point implied the existence of potential gradients along the magnetic field lines. The deceleration of the main core was greater than theoretically predicted. This was attributed to the formation of a polarization wake, resulting in an increase of the area of interaction and resistive dissipation at ionospheric levels. The actual orientation of the magnetic field line through the release point differed by about 10.5 deg from that predicted by magnetic field models that did not include the effect of ring current

Local Axisymmetric Diffusive Stability of Weakly-Magnetized, Differentially-Rotating, Stratified Fluids

We study the local stability of stratified, differentially-rotating fluids to axisymmetric perturbations in the presence of a weak magnetic field and of finite resistivity, viscosity and heat conductivity. This is a generalization of the Goldreich-Schubert-Fricke (GSF) double-diffusive analysis to the magnetized and resistive, triple-diffusive case. Our fifth-order dispersion relation admits a novel branch which describes a magnetized version of multi-diffusive modes. We derive necessary conditions for axisymmetric stability in the inviscid and perfect-conductor (double-diffusive) limits. In each case, rotation must be constant on cylinders and angular velocity must not decrease with distance from the rotation axis for stability, irrespective of the relative strength of viscous, resistive and heat diffusion. Therefore, in both double-diffusive limits, solid body rotation marginally satisfies our stability criteria. The role of weak magnetic fields is essential to reach these conclusions. The triple-diffusive situation is more complex, and its stability criteria are not easily stated. Numerical analysis of our general dispersion relation confirms our analytic double-diffusive criteria, but also shows that an unstable double-diffusive situation can be significantly stabilized by the addition of a third, ostensibly weaker, diffusion process. We describe a numerical application to the Sun's upper radiative zone and establish that it would be subject to unstable multi-diffusive modes if moderate or strong radial gradients of angular velocity were present.Comment: 29 pages, 1 table, accepted for publication in Ap

Isolated Sub-Dehumidification Strategies in Large Supermarkets and Grocery Stores

The objective of this project was to determine the potential energy savings associated with reducing the relative humidity in the vicinity of refrigerated display cases in supermarkets, as compared to the widely accepted current practice of maintaining a relatively higher and uniform humidity level throughout the entire supermarket. Existing and new strategies for maintaining lower relative humidity levels near the vicinity of refrigerated display cases were analyzed to determine their effectiveness and limits of application

Elliptic aspects of statistical mechanics on spheres

Our earlier results on the temperature inversion properties and the ellipticisation of the finite temperature internal energy on odd spheres are extended to orbifold factors of odd spheres and then to other thermodynamic quantities, in particular to the specific heat. The behaviour under modular transformations is facilitated by the introduction of a modular covariant derivative and it is shown that the specific heat on any odd sphere can be expressed in terms of just three functions. It is also shown that the free energy on the circle can be written elliptically.Comment: 22 pages. JyTe

Energy Consumption and Product Throughput of Glass-Doored and Open Refrigerated Display Cases in Supermarkets [abstract]

Only abstract of poster available.Track III: Energy InfrastructureRefrigerated display cases are utilized by supermarkets to store and display food products in a manner that extends food shelf life and ensures food safety. Supermarkets operate their refrigeration systems continuously to maintain proper food storage conditions. Continual operation of this refrigeration equipment on a nationwide scale accounts for approximately 0.33 quads/yr of electrical energy. Infiltration accounts for over 70% of the refrigeration load in open refrigerated display cases. Clearly, an increase in the energy efficiency of refrigerated display cases will result in significantly reduced energy consumption and cost. Thus, the objective of this project is to compare a typical open refrigerated display case to a typical glass-doored refrigerated display case with the aim of quantifying the following: • The difference in overall energy consumption between the cases. • The normalized difference in food product sales between the cases. Two supermarkets are being used as test sites, which are similarly situated to ensure that climate, weather, time-of-year and economic conditions of the shoppers are comparable. One supermarket will receive an open refrigerated display case and the other will receive a doored refrigerated display case. Each refrigerated display case will be a medium temperature, self-service prepackaged deli or beverage case between 8 and 25 nominal linear feet. The thermal performance and product sales of each refrigerated display case will be monitored. Automated data logging systems will be used to measure quantities such as refrigeration load, voltage, current, temperature, humidity and pressure. Product sales for each refrigerated display case and total store product sales will be tracked using Stock Keeping Units (SKUs) and the supermarkets' computerized Point of Sale (POS) system. The resulting data will be analyzed to determine the difference in energy consumption and product sales between the two refrigerated cases

“From sweet potatoes to God Almighty”: Roy Rappaport on being a hedgehog

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/71618/1/ae.2007.34.3.581.pd