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Results for “nondestructive measurement”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 127 records · Page 7
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Beta Backscatter Measures the Hardness of Rubber

Nondestructive testing method determines hardness, on Shore scale, of room-temperature-vulcanizing silicone rubber. Measures backscattered beta particles; backscattered radiation count directly proportional to Shore hardness. Test set calibrated with specimen, Shore hardness known from mechanical durometer test. Specimen of unknown hardness tested, and radiation count recorded. Count compared with known sample to find Shore hardness of unknown.

Morrissey, E. T.↗
NASA NTRS2024

Future of the Search for Life: Workshop Report

The 2-week, virtual Future of the Search for Life science and engineering workshop brought together more than 100 scientists, engineers, and technologists in March and April 2022 to provide their expert opinion on the interconnections between life-detection science and technology. Participants identified the advances in measurement and sampling technologies they believed to be necessary to perform in situ searches for life elsewhere in our Solar System, 20 years or more in the future. Among suggested measurements for these searches, those pertaining to three potential indicators of life termed “dynamic disequilibrium,” “catalysis,” and “informational polymers” were identified as particularly promising avenues for further exploration. For these three indicators, small breakout groups of participants identified measurement needs and knowledge gaps, along with corresponding constraints on sample handling (acquisition and processing) approaches for a variety of environments on Enceladus, Europa, Mars, and Titan. Despite the diversity of these environments, sample processing approaches all tend to be more complex than those that have been implemented on missions or envisioned for mission concepts to date. The approaches considered by workshop breakout groups progress from nondestructive to destructive measurement techniques, and most involve the need for fluid (especially liquid) sample processing. Sample processing needs were identified as technology gaps. These gaps include technology and associated sampling strategies that allow the preservation of the thermal, mechanical, and chemical integrity of the samples upon acquisition; and to optimize the sample information obtained by operating suites of instruments on common samples. Crucially, the interplay between science-driven life-detection strategies and their technological implementation highlights the need for an unprecedented level of payload integration and extensive collaboration between scientists and engineers, starting from concept formulation through mission deployment of life-detection instruments and sample processing systems.

Marc Neveu↗
NASA NTRS1990

Phase conjugate Twyman-Green interferometer for testing spherical surfaces and lenses and for measuring refractive indices of liquids or solid transparent materials

The present paper describes an application of a phase conjugate Twyman-Green interferometer using barium titanate as a self-pumping mirror for testing optical components like concave and convex spherical mirrors and lenses. The aberrations introduced by the beam splitter while testing concave or convex spherical mirrors of large aperture are automatically eliminated due to self-focussing property of the phase conjugate mirror. There is no necessity for a good spherical surface as a reference surface unlike in classical Twyman-Green interferometer or Williams interferometer. The phase conjugate Twyman Green interferometer with a divergent illumination can be used as a test plate for checking spherical surfaces. A nondestructive technique for measuring the refractive indices of a Fabry Perot etalon by using a phase conjugate interferometer is also suggested. The interferometer is found to be useful for measuring the refractive indices of liquids and solid transparent materials with an accuracy of the order of + or - 0.0004.

Shukla, R. P.↗
DOE OSTI2024

Picosecond Ultrasonics in Magnetic Topological Insulator MnBi 2 Te 4

MnBi 2 Te 4 is a magnetic topological insulator with layered A-type antiferromagnetic order. It exhibits a rich layer- and magnetic-state dependent topological phase diagram; however, much about the coupling between spin, charge, and lattice remains to be explored. Here, in this work, we report that MnBi 2 Te 4 is an excellent acoustic phonon cavity by realizing phonon frequency combs using picosecond ultrasonics. With the generated acoustic phonon wavepackets, we demonstrate that the timing and phase of acoustic echoes can be used to detect the presence of stacking faults between van der Waals layers buried deep within the crystal. Furthermore, by implementing this nondestructive ultrafast optical measurement in conjunction with time-resolved magneto-optical Kerr effect experiments, we uncover that out-of-plane vibrations in MnBi 2 Te 4 do not couple to the magnetic order, i.e. there is no appreciable magnetostriction. Our work points out how a well-developed technique can probe the structural defects and phonon pulse engineering in layered topological insulators.

36 MATERIALS SCIENCE↗
DOE OSTI2025

High-Intensity UV Exposure for the Rapid Screening of Silicon Photovoltaic Architectures

Advanced Si photovoltaic architectures incorporate different materials and processing pathways that influence degradation modes. Ultraviolet-induced degradation (UVID) is an understudied degradation mode for advanced cell architectures and is of increasing concern to industry due to growing adoption of UV-transparent encapsulation and bifacial technologies. In order to adopt new and evolving technologies confidently, novel component materials and processing techniques must be evaluated and designed for long-term stability, in addition to the conventional design focus on efficiency. In this work, a study protocol framework is presented for the rapid screening of unencapsulated devices against UVID. Unencapsulated passivated emitter rear contact (PERC) and tunnel oxide passivated contact (TOPCon) devices were aged under different UV irradiance intensities and measured via conventional nondestructive electrical characterization methods to assess performance degradation. Based on the results, protocol efficacy and recommendations for further study are discussed. As a result, this work is part of a broader effort to develop rapid screening processes that cut across architectures and exposure conditions to aid module manufacturers in vetting new materials choices for long-term stability.

Accelerated exposure↗
DOE OSTI2026

Surface Stress Characterization and Trends in Thermally Strengthened Photovoltaic Module Glass

Simultaneous changes in photovoltaic (PV) module architecture-such as increased area, replacing the polymeric backsheet with a glass backsheet, and reducing glass thickness from 3.2 to 2.0 mm-have resulted in a novel failure called spontaneous glass breakage. Spontaneous glass breakage results in front and/or rear glass failure without any obvious cause. The resulting low-energy fracture patterns have raised concerns about the thermal strengthening in 2.0-mm glass. We present validation of a nondestructive method for measuring the glass surface stress in PV modules. We use a scattered light polariscope to examine the glass properties of 11 modules from 6 solar fields, with and without spontaneous glass breakage. Based on a Mann-Whitney test p-value of 1.4 x 10-6, we conclude that there is a correlation between lower surface stress and susceptibility to spontaneous breakage. A Kendall's Tau test p-value of 2.0 x 10-4 indicates a correlation between increased module area and lower surface stress. We find that 2.0-mm glass can be, and often is, fully tempered (surface stress ≥69 MPa), but inspecting the fracture pattern is not a reliable way to assess the amount of thermal strengthening. A combination of factors, not just surface stress, influences glass breakage.

14 SOLAR ENERGY↗
NASA NTRS1968

Dc pin-to-pin testing of integrated circuits

External pin-to-pin nondestructive testing procedure measures the electrical characteristics of each element in an integrated circuit. The procedure involves choosing specific pairs of pins and applying appropriate test voltages to them.

Thomas, E. F.↗
NASA NTRS1979

High temperature dynamic modulus and damping of aluminum and titanium matrix composites

Dynamic modulus and damping capacity property data were measured from 20 to over 500 C for unidirectional B/Al (1100), B/Al (6061), B/SiC/Al (6061), Al2O3/Al, SiC/Ti-6Al-4V, and SiC/Ti composites. The measurements were made under vacuum by the forced vibration of composite bars at free-free flexural resonance near 2000 Hz and at strain application below 0.000001. The damping of B/Al composites was found at all temperatures to be significantly greater than the damping of the Al2O3/Al and SiC/Ti composites, with little variation observed in the dynamic moduli of specimens having almost the same fiber content. It is concluded that on the practical level, the finding of a damping-strength correlation supports the use of composite damping measurements for the nondestructive evaluation of boron fiber strength in as-fabricated and heat-treated B/Al (6061) composites.

Dicarlo, J. A.↗
NASA NTRS1986

Effects of surface chemistry on hot corrosion life

Burner rig tests were conducted under the following conditions: 900 C, hourly thermal cycling, 0.5 ppm sodium as NaCl in the gas stream, and Mach 0.3 velocity. The alloys tested were Udimet 700 (U700) and Rene 80, uncoated and with RT21, Codep, or NiCoCrAlY coatings. The tests, up to 1000 hours, included specimens in the as-processed condition and after aging at 1100 C in oxidizing or inert environments for up to 600 hours. Coil-inductance changes were measured for periodic nondestructive inspection of speciments and found useful in the following course of corrosion. Typical sulfidation observed in all cases was similar to that observed in service-run turbine components. Aging at 1100 C caused severe decrease in the hot corrosion life of RT21 and Codep coatings and a significant but lesser decrease in the life of NiCoCrAlY coatings. The extent of these decreases was much greater for all three coatings on U700 than on Rene substrates. A coating hot corrosion life-predicitin model was proposed. The model requires time/temperature information for a turbine component at takeoff conditions as well as environmental contaminant information.

Fryxell, R. E.↗
NASA NTRS1989

Ultrasonic Detection Of Transply Cracks In Composites

Nondestructive testing technique measures densities of transply cracks and used to monitor propagation of such damage in advanced polymer-matrix composite materials. Acousto-ultrasonic measuring apparatus, used to measure stress-wave factors (SWF's) of undamaged specimens and specimens that contained various numbers of transply cracks. Acousto-ultrasonic technique of value in examining damage to material from one surface only.

Bowles, Kenneth J.↗
NASA NTRS1988

Monitoring cure of composite resins using frequency dependent electromagnetic sensing techniques

A nondestructive in situ measurement technique has been developed for monitoring and measuring the cure processing properties of composite resins. Frequency dependent electromagnetic sensors (FDEMS) were used to directly measure resin viscosity during cure. The effects of the cure cycle and resin aging on the viscosity during cure were investigated using the sensor. Viscosity measurements obtained using the sensor are compared with the viscosities calculated by the Loos-Springer cure process model. Good overall agreement was obtained except for the aged resin samples.

Kranbuehl, D. E.↗
NASA NTRS1990

Determination of refractive index of a simple negative, positive, or zero power lens using wedged plated interferometer

A nondestructive technique for measuring the refractive index of a negative lens using a wedged plate interferometer is described. The method can be also used for measuring the refractive index of convex or zero power lenses. Schematic diagrams are presented for the use of a wedged plate interferometer for measuring the refractive index of a concave lens and of a convex lens.

Shukla, R. P.↗
NASA NTRS1991

Regulated bioluminescence as a tool for bioremediation process monitoring and control of bacterial cultures

An effective on-line monitoring technique for toxic waste bioremediation using bioluminescent microorganisms has shown great potential for the description and optimization of biological processes. The lux genes of the bacterium Vibrio fischeri are used by this species to produce visible light. The lux genes can be genetically fused to the control region of a catabolic gene, with the result that bioluminescence is produced whenever the catabolic gene is induced. Thus the detection of light from a sample indicates that genetic expression from a specific gene is occurring. This technique was used to monitor biodegradation of specific contaminants from waste sites. For these studies, fusions between the lux genes and the operons for naphthalene and toluene/xylene degradation were constructed. Strains carrying one of these fusions respond sensitively and specifically to target substrates. Bioluminescence from these cultures can be rapidly measured in a nondestructive and noninvasive manner. The potential for this technique in this and other biological systems is discussed.

Burlage, Robert S.↗
NASA NTRS1993

Enhanced NDE systems

The goal of this contractual effort was to evaluate the Langley narrow-band ultrasonic debond detection method for a factory use configuration. Successful accomplishment requires establishing the robustness of the method, and enhancing it if necessary. It is also desirable to strive for simplicity of implementation, such as attachment to in-place scanning devices planned for nondestructive evaluation (NDE) measurements. The contract was established with three phases for the ultrasonic work: (1) establish the method and robustness of the ultrasonic method; (2) follow up on any questions which arise with respect to the method or its implementation and produce a Phase A design; and (3) fabricate and test the Phase A design. This is a report on Phase 1.

Source record↗
DOE OSTI2023

Statistical Approaches for Pebble Bed Reactor Operations and Safeguards

The design of pebble bed reactors (PBRs) and their method of operation align more closely with statistical approaches used in manufacturing and process control than traditional safeguards statistical approaches. The reason is PBRs will employ a nondestructive assay (NDA) measurement (burnup measurement system [BUMS]) that is part of the fuel handling system supporting discharge decisions in addition to the reactor code which monitor performance. The integration of these two approaches provides the opportunity to monitor reactor performance statistically for both operations and safeguards in ways not achievable using other reactor designs. For light water reactors (LWRs), knowledge about reactor code performance in predicting irradiated special nuclear material (SNM) content historically was only achieved from special measurement campaigns or from fuel reprocessing. Conversely, through statistical comparison of the BUMS with the reactor code-predicted values, PBRs can achieve this in real time. The resulting SNM distribution is an indicator of reactor performance because factors such as transit time and path of the pebble fuel through the reactor determine the plutonium production and uranium depletion. By analyzing the predicted and measured values, opportunities exist to adjust operating parameters, fuel design, and other characteristics to optimize performance and fuel utilization. From a safeguards perspective, this approach also provides the information necessary to validate declared values and evaluate whether the reactor is being operated as expected. This paper outlines statistical approaches for PBRs that can be used to support both operations and safeguards.

Ball, Cory↗
NASA NTRS1985

Measuring Rind Thickness on Polyurethane Foam

Nondestructive test determines rind thickness of polyurethane foam. Surface harness of foam measured by Shore durometer method: hardness on Shore D scale correlates well with rind thickness. Shore D hardness of 20, for example, indicates rind thickness of 0.04 inch (1 millimeter). New hardness test makes it easy to determine rind thickness of sample nondestructively and to adjust fabrication variables accordingly.

Johnson, C.↗