Special Coverage

Home

Technology Business Briefs

Printable Biosensor for On-Site, Online Measurements -- Bioactive Hybrid Materials for Photonic Microsystems It allows samples to be analyzed on site within a few minutes by integrating biotechnology, information technology, electronics, physics, and chemistry to realize small and cost-effective bio-photonic microsystems. Click here for more info.

Posted in: Blog

Read More >>

NASA News

The Subregional Bone Assessment, a NASA study of the long-term effects of microgravity on the bones of International Space Station crewmembers, showed that the astronauts lost roughly 11% of their total hipbone mass over the course of their mission, more than an elderly woman in a year. While bone mass was regained after a year on Earth, bone structure and density had not recovered. The research focused on weight bearing bones including the hip, which experiences the highest amount of bone loss during a space mission and is the site of the most fractures in the elderly.

Posted in: Blog

Read More >>

Fiber-Optic Ammonia Sensors

Reversible, colorimetric fiber-optic sensors are undergoing development for use in measuring concentrations of ammonia in air at levels relevant to human health [0 to 50 parts per million (ppm)]. A sensor of this type includes an optical fiber that has been modified by replacing a portion of its cladding with a polymer coat that contains a dye that reacts reversibly with ammonia and changes color when it does so. The change in color is measured as a change in the amount of light transmitted from one end of the fiber to the other. Responses are reversible and proportional to the concentration of ammonia over the range from 9 to 175 ppm and in some cases the range of reversibility extends up to 270 ppm. The characteristic time for the response of a sensor to rise from 10 to 90 percent of full scale is about 25 seconds. These sensors are fully operational in pure carbon dioxide and are not adversely affected by humidity.

Posted in: Briefs

Read More >>

Silicon Membrane Mirrors With Electrostatic Shape Actuators

Precise shapes could be maintained over a wide temperature range. Efforts are under way to develop deformable mirrors equipped with microscopic electrostatic actuators that would be used to maintain their reflective surfaces in precise shapes required for their intended applications. Unlike actuators that depend on properties of materials (e.g., piezoelectric and electrostrictive actuators), electrostatic actuators are effective over a wide temperature range. A mirror of the present type would be denoted a MEMS-DM (for microelectromechanical system deformable mirror). The reflective surface of such a mirror would be formed on a single-crystal silicon membrane that would be attached by posts to a silicon actuator membrane that would, in turn, be attached by posts to a rigid silicon base (see figure).

Posted in: Briefs, TSP

Read More >>

Nanoscale Hot-Wire Probes for Boundary-Layer Flows

Flow parameters near walls would be measured with unprecedented resolution. Hot-wire probes having dimensions of the order of nanometers have been proposed for measuring temperatures (and possibly velocities) in boundary-layer flows at spatial resolutions much finer and distances from walls much smaller than have been possible heretofore. The achievable resolutions and minimum distances are expected to be of the order of tens of nanometers — much less than a typical mean free path of a molecule and much less than the thickness of a typical flow boundary layer in air at standard temperature and pressure. An additional benefit of the small scale of these probes is that they would perturb the measured flows less than do larger probes.

Posted in: Briefs, TSP

Read More >>

Evaluation of Charge Storage and Decay in Spacecraft Insulators

Two reports discuss methods for evaluating the magnitude of electrostatic charging that occurs in spacecraft dielectric materials (in particular, polyimides) during prolonged exposure to radiation in outer space. The reports describe experiments on the electrical resistivities and charge-storage properties of polyimide specimens in a dark, evacuated environment, both before and after 5-megarad exposures to Υ rays from cobalt-60. The experiments were designed to measure these properties not under standard conditions prescribed for testing dielectrics in air but, rather, under conditions approximating those in the intended spacecraft applications. The results of the experiments showed that the electrical resistivities of the insulations as determined under these conditions are greater, by a factor of roughly a thousand, than those determined under the standard conditions and that the g irradiation reduced resistivities marginally.

Posted in: Briefs, TSP

Read More >>

Instrument for Measuring Temperature of Water

An infrared radiometer is able to view water as an almost pure blackbody source. A pseudo-Brewster- angle infrared radiometer has been proposed for use in noncontact measurement of the surface temperature of a large body of water (e.g., a lake or ocean). This radiometer could be situated on a waterborne, airborne, or spaceborne platform.

Posted in: Briefs

Read More >>

White Papers

High-Speed, Real-Time Recording Systems Handbook
Sponsored by Pentek
Building a Test System for High-Speed Data Streaming Applications
Sponsored by ADLINK Technology
The Truth about Parylene Coating & Medical Devices
Sponsored by diamond-mt
Step on It! Walking for Power
Sponsored by HP
White Papers: Using FPGAs to Improve Embedded Designs
Sponsored by Sealevel
What is Wiring Synthesis?
Sponsored by mentor graphics

White Papers Sponsored By: