ENGINEERING

Materials for Extending Endurance and Productivity of Underwater Divers in Cold Waters
DMI 9461179
06/01/95; (DMI) $10,000; 14 months
Triangle Research and Development Corporation
Research Triangle Park, NC 27709-2696
Yvonne G. Bryant

This Small Business Innovation Research (SBIR) Phase I project will investigate using microencapsulated phase change materials (microPCMs) in a fabric layer as a thermal barrier to extend the endurance and productivity of underwater divers in cold water. MicroPCM-enhanced fabrics could be used alone (passively), or in conjunction with an auxiliary heating device (actively). For Phase I research purposes, the emphasis will be on studying the effectiveness of a microPCM fabric as a thermal barrier in a diver's dry suit. However, the concepts developed here also will apply to wet suits. Phase I objectives will be to: select, encapsulate and evaluate thermal properties of appropriate PCMs; acquire coated microPCM fabric samples and controls and evaluate their thermal properties; design laboratory tests to evaluate thermal performance of test fabrics; and evaluate thermal performance of test fabrics with and without auxiliary heating. The potential use of microPCM material to keep divers comfortable and extend their work period will be thoroughly examined and recommendations will be made to the NSF for a follow-on Phase II effort.

A Subsurface Volume Imaging Radar for Polar Region Ice Studies
DMI 9560637
03/01/96; (DMI) $74,910; 6 months
Quadrant Engineering
Amherst, MA 01002
Philip M. Langlois

This (SBIR) Phase I project describes remote sensing of the physical properties of Earth's surface and subsurface with radar systems. It is of generic interest to the geophysical sciences community and is important to a wide range of military and commercial applications. Recently, an experimental radar was used by researchers from the University of Kansas to map the thickness of the Jacobshavn glacier in Greenland. This radar produced high-range resolution measurements of ice thickness, but suffered from very coarse cross-track resolution. This proposal describes a novel nadir-looking imaging radar system that can provide three-dimension volume images of the structure and depth of glaciers and icebergs to depths of several kilometers. Utilizing a conformal array of many antenna elements mounted on the underside of an aircraft wing, we can use digital beamforming techniques to generate up to 40 beams in the cross-track direction, each with a narrow 1.4­3 degree beamwidth. Along-track resolution will be achieved by unfocused Synthetic Aperture Radar (SAR) processing. The resultant volume images generated by this radar will have spatial resolution on the order of 30 m x 30 m x 30 m at ranges from 1 to 2 km, sampled from the top surface down to ground level several kilometers below the surface. Potential commercial applications include surveying ice in polar regions, as well as subsurface imaging of metallic objects, hazardous waste, tunnels, and detection of hard targets through foliage.

Development of a Frazil Ice Meter
DMI 9561330
04/01/96; (DMI) $74,922; 6 months
WET Labs, Inc.
Philomath, OR 97370-0518
Casey C. Moore

This (SBIR) Phase I project is to develop a differential absorption meter optimized for frazil ice detection. Small crystals known as frazil ice form when heat is removed from a turbulent water body that is at, or below, the freezing point. This process proves a major factor in ice formation of northern lakes and exposed polar oceanic bodies, and plays an important role in numerous physical and biological processes. In addition, frazil ice formation can severely impact various cold-climate industrial water use processes. Yet the mechanism, it's prevalence, and the associated dynamics remain poorly understood, largely for lack of effective instrumentation. Researchers recently successfully tested a measurement technique in which the differential absorption of water and ice were determined to yield ice crystal concentration. This technique shows great promise in becoming an accepted method if an instrument can be developed to effectively exploit it. Phase I effort will focus upon the development and testing of a proof of principal prototype. Commercial uses of this meter range from research applications to environmental and process monitoring. Potential customers include scientists, government agencies, hydroelectric power authorities, municipal water authorities, shipping companies and other industrial concerns.

Dynamics of Ice Surfaces
DMR 9623590
05/01/96; (DMR) $100,000; 12 months
University of Washington
Seattle, WA 98195
Samuel C. Fain

Fain Ice is important in a number of environments on the Earth, in the atmosphere, on other planets, and in space. The objective of this project is to understand the interaction between ice surfaces and other solids in a controlled environment at temperatures near the triple point. Dynamical measurements of the normal and lateral forces exerted on scanning mechanical probes by the surface of ice will be made as a function of temperature, atmosphere above the ice surface and electric potential between the probe and the ice. The probe could be a very sharp point or a very small diameter sphere; forces exerted on the probe as it comes into contact with the surface will be measured by deflecting a laser beam from a microscopic lever. The fundamental information obtained by such microscopic scale measurements will aid in understanding macroscopic mechanical interactions between ice surfaces and other solids such as occur in the adhesion of ice to objects in a cold environment.