Low-cost, compact, cooled photomultiplier assembly for use in magnetic fields up to 1400 Gauss

Use of vortex tube for cooling and concentric shielding have produced smaller and more compact unit than was previously available. Future uses of device could include installation in gas chromatographs and mass spectrometers. Additional uses would include measurements and controls in magnetohydrodynamic power generators and fusion reactors

Liturgy at Ground Level

(Excerpt) On the back yard of our parish lot is a patch of ground I drive by every day. It is the place where we have a bonfire of trees and greens on the Twelfth Night of Christmas. Each Ash Wednesday, if it is not covered by snow, it is a blackened smudge on the face of the lawn. By Easter, however, that patch seems the most alive. For there the green blade rises, unhindered by dead overgrowth, looking even greener against the charred earth

On the road to recovery, soft patches turn up often

Business cycles ; Economic conditions

A pentagonal surface patch for computer-aided geometric design

A vector valued interpolation scheme for a pentagon is described which is compatible with surface patches which have a rectangular domain of definition. Such a scheme could be useful in computer- aided geometric design problems, where a pentagonal patch occurs within a rectangular patch framework

Seasonal dependency of polar cap patches in the high-latitude nightside ionosphere

Observations and a computer simulation were used to investigate the seasonal dependency of the occurrence of polar cap patches in the high-latitude nightside ionosphere together with the relative importance of the driving processes. Measurements were conducted above northern Scandinavia around solar maximum (1999-2001) under conditions predicted to be favourable for observing patches with the EISCAT Svalbard Radar (ESR). The requirements were that the ESR was poleward of the convection reversal boundary, in antisunward cross polar cap flow and that IMF Bz was predominantly negative. The high latitude convection pattern was inferred from the Super Dual Auroral Radar Network (SuperDARN) and the IMF was taken from the Advanced Composition Explorer (ACE) spacecraft. In each study the patch-to-background ratio was calculated and, in most of the winter cases, this ratio was greater than two consistent with a polar cap patch. In summer clear electron density enhancements were seen in the nightside ionosphere, but the patch-to-background ratio was less than two. While these enhancements could not formally be called patches, it was clear that the high-latitude convection pattern was responsible for electron density enhancements. Using a computer simulation the relative importance of the physical processes driving the variation in the patch-to-background ratio was investigated. The dominant factor was changes in the thermospheric composition influencing plasma production and recombination rates

Miniature Wideband stacked microstrip patch antenna based on the sierpinski fractal geometry

The main interest in the design of a miniature microstrip patch antenna (MPA) is its small size in conjunction with the well-known advantages of a MPA (cost, profile, weight). However there is a big constraint on the bandwidth limitation either in a miniature antenna or in a MPA. The proposed solution to overcome such problem is to couple a miniature parasitic resonator to the miniature active patch forming a wideband small stacked microstrip patch antenna.Peer ReviewedPostprint (published version

A Dual Band Belt Antenna

This paper presents an antenna structure design using a standard belt for wearable applications. The antenna arouse from a body of research work on wearable metallic structures functioning as antennas for wireless on-body networks