Test & Measurement

Measurement of the Mechanical Properties of Thin Film Polymers at Cryogenic Temperatures

A new apparatus uses pressurized liquid nitrogen to measure deformation. John F. Kennedy Space Center, Florida The measurement of structural properties of materials at cryogenic temperatures is a daunting task. The measurement of thin films at low temperatures is even harder. Current practices of immersing the material in a cryogenic fluid and then removing and testing it does not work due to the rapid warming of the low-mass thin film. Similarly, exposing it to a cold vapor environment, unless well controlled procedurally, does not yield data at a known temperature (the temperature of the material is unknown). Thus, gathering basic material properties of thin film materials at low temperature requires a new approach.

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Estimation of Algae Growth Stage, Growth Rate, and Lipid Content

Applications include diesel fuel production, renewable energy, biofuels, and pharmaceuticals. Ames Research Center, Moffett Field, California This invention provides a method using light of different wavelengths to estimate freshwater and marine algae growth stage and algae growth rates as well as lipid content in standard media. Light absorption by the algae is measured for a specified light intensity in each of two or more narrow wavelength ranges, correcting for absorption in the medium without algae. The net light absorption is compared with a reference set of absorption values for the algae at different growth stages.

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Isotopic Biomarkers for Rapid Assessment of Bone Mineral Balance in Biomedical Applications

Advanced isotope tracer techniques are explored. Lyndon B. Johnson Space Center, Houston, Texas Development of new treatments for metabolic bone disease, and evaluation of the effectiveness of existing therapies in individual patients, are severely hampered by the lack of any reliable tool for quickly measuring changes in bone mineral balance in response to treatment. A new tracerless calcium isotope biomarker of bone mineral balance fills this need. When properly applied, the calcium isotope biomarker reveals changes in bone mineral balance with unprecedented speed and detail, and has the potential to dramatically improve the treatment for diseases such as osteoporosis. A complementary strontium isotope biomarker provides, with equal rapidity, information on the speed of exchange of calcium between soft tissue and mineralized compartments.

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Optically Modulated Miniature Magnetometer

This instrument may replace two separate instruments that are often needed together to study magnetic fields. Goddard Space Flight Center, Greenbelt, Maryland The optically modulated miniature magnetometer (OMMM) is intended to replace two separate instruments (each with their respective mass and power allotments) that are commonly needed together for scientific studies of magnetic fields — a triaxial fluxgate vector magnetometer and an optically pumped alkali vapor scalar magnetometer. For all vector instruments, the scalar data is necessary for calibrating the vector data.

Posted in: Briefs, TSP

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Quantitative Analysis of Failure Mode in Adhesively Bonded Test Specimens

A fluorescence visualization technique is used. Langley Research Center, Hampton, Virginia After adhesively bonded mechanical test specimens have been tested to failure, the failure mode must be interpreted and quantified. Areas of the adherent that are bare (no residual adhesive remains) have undergone adhesive failure. The remainder of the surface has undergone cohesive failure. The ability to distinguish and accurately quantify the relative amounts of cohesive and adhesive failure on a failed bonding surface is of tremendous importance in the field of mechanical testing, and for the development of bonded assemblies. Some adhesives (and adherents) are fluorescent, meaning they re-emit light at a different wavelength after being irradiated by some lighting source. This property allows for quantitative analysis of the adhesive failure mode (adhesive and cohesive). A digital image of the fluorescing adhesive or adherent can be analyzed and quantified using publicly available software to determine the relative areas of exposed and covered adherent surface.

Posted in: Briefs, TSP

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Energy-Based Acoustic Measurement System for Rocket Noise

Marshall Space Flight Center, Alabama Development of the next generation of spaceflight vehicles has prompted a renewed focus on sound source characterization and near-field propagation modeling. Without advancements in these areas, large uncertainties in vibro-acoustic loading estimates on space vehicles and payloads may result in structural designs that are either insufficient or excessive.

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Mass Gauging Demonstrator for Any Gravitational Conditions

Marshall Space Flight Center, Alabama This concept uses an optical interferometric method to determine the density and/or pressure of the gas state contained with tank ullage. The system is similar to compression tank volume methods. By using an optical interferometric technique to determine gas density and/or pressure, a much smaller compression volume or higher-fidelity measurement is possible.

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