Test & Measurement

Measurement of O-phthalaldehyde (OPA)

This analytical process uses high-pressure liquid chromatography (HPLC) with post-column derivatization.

O-phthalaldehyde (OPA) is a high-level disinfectant commonly used, for example, for sterilization of heat-sensitive medical instruments; it demonstrates effective microbicidal activity against a wide range of microorganisms (including mycobacteria, gramnegative bacteria, and spores). On the International Space Station (ISS), to achieve thermal control and maintain components at acceptable temperatures, systems that produce waste heat need to have that heat transferred from the ISS to space. To accomplish this, the ISS has an Internal Active Thermal Control System (IATCS) — a water-based system that works in conjunction with the EATCS (External ATCS), an ammoniabased system — to facilitate this heat transfer process.

Posted in: Briefs, Test & Measurement, Thermal management, Thermal management, Chemicals, Waste materials, Coolants, Spacecraft

Improved Combustion Products Monitor for the ISS

Applications include fire and environmental analyzers in aircraft, submarines, and industrial plants.

Fire safety in space vehicles is of utmost importance, especially for manned flight. On the International Space Station (ISS), events that may lead to fires, especially smoldering, must be detected quickly and their location found. The analyzer used on the ISS must be automated, portable, and sensitive to the gases that are most likely to indicate the presence of a fire or pre-ignition event. In addition, after any fire event, the monitor must be useful to indicate that toxic gas levels have subsided for safe reentry of the crew to the affected area. Gases of interest may originate from the smoldering of Teflon wires, polyurethane foams, Delrin, and other plastics and furnishings in the ISS.

Posted in: Briefs, TSP, Test & Measurement, Fire detection, Protective equipment, Spacecraft

Decomposition Technique for Remaining Useful Life Prediction

This invention has applications in electronic systems, mining, medical equipment, power generation, smart buildings, transportation vehicles, and industrial machinery.

Technology has been developed that provides a way to compute the remaining useful life (RUL) of a component or system. The estimation of the RUL of a degraded or faulty component is at the center of condition-based maintenance, and prognostics and health management. It gives operators a potent tool in decision-making by quantifying how much time is left until functionality is lost. This is especially important for aerospace systems, where unanticipated subsystem or component failure may lead to failure of the system as a whole, which in turn may adversely affect the safety of operation.

Posted in: Briefs, Test & Measurement, Failure modes and effects analysis, Life cycle analysis, Prognostics

Strain Gage for Highly Elastic, Low-Modulus Materials

This gage surpasses conventional foil technology, measuring elastic strain range greater than 100 percent while reducing measurement error.

Researchers at NASA’s Armstrong Flight Research Center have developed and tested a new strain gage that makes significant strides in the state of the art, particularly salient given the requirements of new structural components on aerospace vehicles. Conventional foil technology presents a significant shortcoming for these vehicles, since it is limited to less than 20 percent strains while newer vehicles include highly elastic, low-Young’s-modulus materials that require higher strain measurements. For example, fabric-reinforced rubbers and elastomers have a nonlinear stressstrain relationship with extreme rupture strains — some greater than 500 percent.

Posted in: Briefs, Test & Measurement, Elastomers, Materials properties

Improved Detection of Kidney Stones Using S-mode Ultrasound

Steps were developed to improve kidney stone detection relative to surrounding tissue.

Ultrasound has been a useful tool in the detection of kidney stones. It is a low-cost solution that does not require ionizing radiation that would be harmful to vulnerable populations such as children and recurrent stone formers. However, it suffers from a broad range of sensitivity (78 to 96%) and specificity (31 to 100%) in the detection of stones.

Posted in: Briefs, Test & Measurement, Imaging, Imaging and visualization, Imaging, Imaging and visualization, Children, Diagnosis, Diseases, Medical equipment and supplies

Vector Network Analyzer Calibration for Quasi-Optical Dual Ports

It is desirable to measure the electromagnetic properties of devices and materials in the millimeter part of the spectrum. For guided wave-based devices and materials (waveguides, coaxial devices), a vector network analyzer (VNA) is an excellent tool for this purpose since it provides full reflection and transmission characterization at high precision.

Posted in: Briefs, TSP, Test & Measurement, Calibration, Electromagnetic compatibility, Waveguides, Electromagnetic compatibility, Waveguides, Materials properties, Test equipment and instrumentation

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

A new apparatus uses pressurized liquid nitrogen to measure deformation.

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.

Posted in: Briefs, Test & Measurement, Measurements, Materials properties, Polymers, Test procedures

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

Applications include diesel fuel production, renewable energy, biofuels, and pharmaceuticals.

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.

Posted in: Briefs, Test & Measurement, Measurements, Biomaterials, Materials properties, Test procedures, Marine vehicles and equipment

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

Advanced isotope tracer techniques are explored.

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.

Posted in: Briefs, Test & Measurement, Measurements, Biological sciences, Diseases, Medical equipment and supplies, Calcium

Optically Modulated Miniature Magnetometer

This instrument may replace two separate instruments that are often needed together to study magnetic fields.

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, Test & Measurement, Optics, Optics, Magnetic materials, Test equipment and instrumentation

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