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Sample records for material properties test

  1. ESTEC wiring test programme materials related properties

    NASA Technical Reports Server (NTRS)

    Judd, M. D.

    1994-01-01

    Electrical wires are considered as EEE parts and are covered within the ESA SCC specification series (ESA SCC 3901/XXX). This specification defines the principal properties of the wires including insulation/lay-up and electrical properties. Some additional space related materials requirements are also included, requirements such as outgassing and silver plating thickness. If a project has additional materials requirements over and above those covered by the relevant SCC specification, then additional testing is required. This is especially true for crewed spacecraft. The following topics are discussed in this context: additional requirements for manned spacecraft; flammability; arc tracking; thermal decomposition; microbial surface growth; and ageing.

  2. Wiring test program insulation material related properties

    NASA Technical Reports Server (NTRS)

    Reher, Heinz-Josef

    1995-01-01

    This viewgraph presentation provides an overview of activities at DASA-RI concerning the testing of wires for manned spacecraft, including test facilities, arc-tracking tests, flammability tests, microgravity tests, and standardization, and outlines future activities.

  3. Means for ultrasonic testing when material properties vary

    DOEpatents

    Beller, Laurence S.

    1979-01-01

    A device is provided for maintaining constant sensitivity in an ultrasonic testing device, despite varying attenuation due to the properties of the material being tested. The device includes a sensor transducer for transmitting and receiving a test signal and a monitor transducer positioned so as to receive ultrasonic energy transmitted through the material to be tested. The received signal of the monitor transducer is utilized in analyzing data obtained from the sensor transducer.

  4. Cyclic material properties tests supporting elastic-plastic analysis development

    SciTech Connect

    Hodge, S.C.; Minicucci, J.M.

    1996-11-01

    Correlation studies have shown that hardening models currently available in the ABAQUS finite element code (isotropic, kinematic) do not accurately capture the inelastic strain reversals that occur due to structural rebounding from a rapidly applied transient dynamic load. The purpose of the Cyclic Material properties Test program was to obtain response data for the first several cycles of inelastic strain reversal from a cyclic properties test. This data is needed to develop elastic-plastic analysis methods that can accurately predict strains and permanent sets in structures due to rapidly applied transient dynamic loading. Test specimens were cycled at inelastic strain levels typical of rapidly applied transient dynamic analyses (0.5% to 4.0%). In addition to the inelastic response data, cyclic material properties for high yield strength (80 ksi) steel were determined including a cyclic stress-strain curve for a stabilized specimen. Two test methods, the Incremental Step method and the Companion specimen Method, were sued to determine cyclic properties. The incrementally decreasing strain amplitudes in the first loading block of the Incremental Step method test is representative of the response of structures subjected to rapidly applied transient dynamic loads. The inelastic strain history data generated by this test program will be used to support development of a material model that can accurately predict inelastic material behavior including inelastic strain reversals. Additionally, this data can be used to verify material model enhancements to elastic-plastic finite element analysis codes.

  5. Correlation of elastomer material properties from small specimen tests and scale-size bearing tests

    SciTech Connect

    Kulak, R.F.; Hughes, T.H.

    1994-06-01

    Tests were performed on small-size elastomer specimens and scale-size laminated elastomeric bearings to correlate the material properties in shear between the two types of tests. An objective of the tests was to see how well the material properties that were determined from specimen tests could predict the response of scale-size laminated elastomeric bearings. Another objective was to compare the results of specimen test and scale-size bearing test conducted by different testing organizations. A comparison between the test results from different organizations on small specimens showed very good agreement. In contrast, the correlation of scale-size bearing tests showed differences in bearing stiffness.

  6. Laboratory experiments designed to test the remediation properties of materials

    SciTech Connect

    Gilbert, J.S.; Wildeman, T.R.; Ford, K.L.

    1999-07-01

    Passive treatment systems constructed to remediate mine drainage have proven to be very successful for a wide variety of drainage compositions and volumes. The construction of an anaerobic passive treatment system requires a mixture of local materials with the objective of producing a system that allows adequate water flow while supporting the growth of sulfate-reducing bacteria. These bacteria have the effect of reducing the oxidizing potential in the system causing many sulfide-forming metals in solution to precipitate. The focus of these experiments was the study of chemical characteristics of materials, individually and in mixtures, with the purpose of determining which would be best suited for incorporation into a treatment system. The materials of interest were manure (fresh and aged), alfalfa, limestone, and sawdust, which were all collected in close proximity to the construction site of the proposed treatment system. A variety of chemical and physical hypotheses were formulated prior to performing simple chemical characterization and anaerobic treatment tests. The hypotheses relating to the chemical nature of the single materials were carbon to nitrogen ratio, availability of low molecular weight organic acids, number of adsorption sites, and organic carbon content. In addition, hypotheses concerning the performance of mixtures were evaluated by looking at the relative amount of bacterial growth (and metal removal) seen in each mixture over a 4-week period. The results of the laboratory experiments confirmed hypotheses, and demonstrated that in the mixtures, the anaerobic bacteria flourish when alfalfa is present, up to a point. The best mixture that allowed proliferation of bacteria while also removing metals consisted of 50% limestone, 25% aged manure, 15% sawdust, and 10% alfalfa (% by weight).

  7. Cyclic Material Properties Test to Determine Hardening/Softening Characteristics of HY-80 Steel

    SciTech Connect

    S.C. Hodge; J.M. Minicucci; T.F. Trimble

    2003-04-30

    The Cyclic Material Properties Test was structured to obtain and provide experimental data for determining cyclic hardening/softening characteristics of HY-80 steel. The inelastic strain history data generated by this test program and the resulting cyclic stress-strain curve will be used to enhance material models in the finite element codes used to perform nonlinear elastic-plastic analysis.

  8. Research study for materials/properties test results database

    NASA Technical Reports Server (NTRS)

    1988-01-01

    The Lubricants Data Base System was designed and developed for operation on the DEC PDP 11/24 computer. The procedures are written in Datatrieve. In transferring the Lubricants System to the VAX 8600 computer, the Datatrieve had to be 80 percent rewritten. At the end of the contract the Lubricants System is operational on both the PDP 11/24 and VAX 8600 computers. The LOX/GOX, Aluminum/Steel, Toxic, VCM, and Flammability Systems are operational only on the PDP 11/24 computer. The Toxic, VCM, and Flammability Systems do not contain any useable data, only test data. However, the LOX/GOX file does contain test data results supplied by MSFC.

  9. Mechanical property tests on structural materials for ITER magnet system at low temperatures in China

    NASA Astrophysics Data System (ADS)

    Huang, Chuanjun; Huang, Rongjin; Li, Laifeng

    2014-01-01

    High field superconducting magnets need strong non-superconducting components for structural reinforcement. For instance, the ITER magnet system (MS) consists of cable-in-conduit conductor, coil case, magnet support, and insulating materials. Investigation of mechanical properties at magnet operation temperature with specimens machined at the final manufacturing stages of the conductor jacket materials, magnet support material, and insulating materials, even the component of the full-size conductor jacket is necessary to establish sound databases for the products. In China, almost all mechanical property tests of structural materials for the ITER MS, including conductor jacket materials of TF coils, PF coils, CCs, case material of CCs, conductor jacket materials of Main Busbars (MB) and Corrector Busbars (CB), material of magnet supports, and insulating materials of CCs have been carried out at the Technical Institute of Physics and Chemistry (TIPC), Chinese Academy of Sciences (CAS). In this paper, the mechanical property test facilities are briefly demonstrated and the mechanical tests on the structural materials for the ITER MS, highlighting test rigs as well as test methods, are presented.

  10. Indentation testing and optimized property identification for viscoelastic materials using the finite element method

    NASA Astrophysics Data System (ADS)

    Resapu, Rajeswara Reddy

    The most common approaches to determining mechanical material properties of materials are tension and compression tests. However, tension and compression testing cannot be implemented under certain loading conditions (immovable object, not enough space to hold object for testing, etc). Similarly, tensile and compression testing cannot be performed on certain types of materials (delicate, bulk, non-machinable, those that cannot be separated from a larger structure, etc). For such cases, other material testing methods need to be implemented. Indentation testing is one such method; this approach is often non-destructive and can be used to characterize regions that are not compatible with other testing methods. However, indentation testing typically leads to force-displacement data as opposed to the direct stress-strain data normally used for the mechanical characterization of materials; this data needs to be analyzed using a suitable approach to determine the associated material properties. As such, methods to establish material properties from force-displacement indentation data need to be identified. In this work, a finite element approach using parameter optimization is developed to determine the mechanical properties from the experimental indentation data. Polymers and tissues tend to have time-dependent mechanical behavior; this means that their mechanical response under load changes with time. This dissertation seeks to characterize the properties of these materials using indentation testing under the assumption that they are linear viscoelastic. An example of a material of interest is the polymer poly vinyl chloride (PVC) that is used as the insulation of some aircraft wiring. Changes in the mechanical properties of this material over years of service can indicate degradation and a potential hazard to continued use. To investigate the validity of using indentation testing to monitor polymer insulation degradation, PVC film and PVC-insulated aircraft wiring are

  11. Analysis of three-point-bend test for materials with unequal tension and compression properties

    NASA Technical Reports Server (NTRS)

    Chamis, C. C.

    1974-01-01

    An analysis capability is described for the three-point-bend test applicable to materials of linear but unequal tensile and compressive stress-strain relations. The capability consists of numerous equations of simple form and their graphical representation. Procedures are described to examine the local stress concentrations and failure modes initiation. Examples are given to illustrate the usefulness and ease of application of the capability. Comparisons are made with materials which have equal tensile and compressive properties. The results indicate possible underestimates for flexural modulus or strength ranging from 25 to 50 percent greater than values predicted when accounting for unequal properties. The capability can also be used to reduce test data from three-point-bending tests, extract material properties useful in design from these test data, select test specimen dimensions, and size structural members.

  12. Test methods for the dynamic mechanical properties of polymeric materials. Final report

    SciTech Connect

    Baker, G.K.

    1980-06-01

    Various test geometries and procedures for the dynamic mechanical analysis of polymers employing a mechanical spectrometer have been evaluated. The methods and materials included in this work are forced torsional pendulum testing of Kevlar/epoxy laminates and rigid urethane foams, oscillatory parallel plate testing to determine the kinetics of the cure of VCE with Hylene MP, oscillatory compressive testing of B-3223 cellular silicone, and oscillatory tensile testing of Silastic E and single Kevlar filaments. Fundamental dynamic mechanical properties, including the storage and loss moduli and loss tangent of the materials tested, were determined as a function of temperature and sometimes of frequency.

  13. Development of a Cryogenic Mechanical Property Testing Station for Superconducting RF Cavity Material

    NASA Astrophysics Data System (ADS)

    Compton, C.; Chandrasekaran, S. K.; Baars, D.; Bieler, T.; Darbandi, P.; Wright, N.

    2010-04-01

    Recent concerns with pressure vessel codes as they relate to the construction of superconducting linacs have raised questions about mechanical proprieties of materials used in their fabrication at cryogenic temperatures. Pressure vessel engineering codes will require demonstration of a level of safety equivalent to that provided by the various ASME pressure and piping codes, so low temperature mechanical properties of niobium, titanium, and their alloys are needed. Michigan State University (MSU), in collaboration with Fermi National Accelerator Laboratory (FNAL) and Florida State University (FSU), is constructing a materials testing station for tensile tests of materials at room and cryogenic temperatures (300, 77, and 4 K). Once complete, the testing station will allow researchers to relate effects of different microstructures arising from manufacturing pathways, including annealing processes, crystal orientations and microstructure characteristics (e.g. welds) to the resulting mechanical properties at cryogenic temperatures. The paper covers the design, construction, and commissioning of the cryogenic testing station, including initial results.

  14. Remarks on Some Mechanical Small-Scale Tests Applied to Properties of Materials

    NASA Astrophysics Data System (ADS)

    Cardu, Marilena; Seccatore, Jacopo

    2016-06-01

    The paper presents the results of test campaigns on small-scale strength properties (particularly, micro-hardness) performed on two homogeneous materials: calcite, a very common and widespread mineral that is characterized by its relatively low Mohs hardness and its high reactivity with even weak acids; and glass, an amorphous solid characterized by the absence of the long-range order which defines crystalline materials. After a synthetic description of the principles underlying two of the three classical comminution laws, known as Kick's law and Rittinger's law, experimental results are discussed. The results of the tests performed show that both scale effect and size effect contribute to the non-constancy of mechanical properties at small scale for crystalline materials. On the other hand, for amorphous materials, a theoretical law considering size effects gives considerably different results from empirical measurements. Considerations and an extended discussion address these findings.

  15. Analysis of materials properties of niobium tube from the results of a virtual bulge test

    NASA Astrophysics Data System (ADS)

    Kim, H. S.; Sumption, Michael; Lim, H.; Collings, E. W.

    2012-06-01

    Hydroforming has been selected as a technique for the seamless fabrication of multicell superconducting radiofrequency (SRF) cavities. For the successful application of this technique to cavity fabrication, it is essential to understand deformation behavior of tubes under hydroforming conditions. Input to the finite-element modeling (FEM) which generally precedes the actual hydroforming process requires the constitutive properties of the tube material. This information may be obtained from the results of hydraulic bulge testing. The present paper provides an example of this activity. In order to verify the steps to be taken in analyzing future bulge-test data a circular argument recovers the original constitutive properties from the results of an FEM-based "virtual bulge test".

  16. Material properties of human rib cortical bone from dynamic tension coupon testing.

    PubMed

    Kemper, Andrew R; McNally, Craig; Kennedy, Eric A; Manoogian, Sarah J; Rath, Amber L; Ng, Tracy P; Stitzel, Joel D; Smith, Eric P; Duma, Stefan M; Matsuoka, Fumio

    2005-11-01

    The purpose of this study was to develop material properties of human rib cortical bone using dynamic tension coupon testing. This study presents 117 human rib cortical bone coupon tests from six cadavers, three male and three female, ranging in age from 18 to 67 years old. The rib sections were taken from the anterior, lateral, and posterior regions on ribs 1 through 12 of each cadaver's rib cage. The cortical bone was isolated from each rib section with a low speed diamond saw, and milled into dog bone shaped tension coupons using a small computer numerical control machine. A high-rate servo-hydraulic Material Testing System equipped with a custom slack adaptor, to provide constant strain rates, was used to apply tension loads to failure at an average rate of 0.5 strains/sec. The elastic modulus, yield stress, yield strain, ultimate stress, ultimate strain, and strain energy density were determined from the resulting stress versus strain curves. The overall average of all cadaver data gives an elastic modulus of 13.9 GPa, a yield stress of 93.9 MPa, a yield strain of 0.88 %, an ultimate stress of 124.2 MPa, an ultimate strain of 2.7 %, and a strain energy density of 250.1 MPa-microstrain. For all cadavers, the plastic region of the stress versus strain curves was substantial and contributed approximately 60 % to the strain energy and over 80 % in the tests with the 18 year old cadaver. The rib cortical bone becomes more brittle with increasing age, shown by an increase in the modulus (p < 0.01) and a decrease in peak strain (p < 0.01). In contrast to previous three-bending tests on whole rib and rib cortical bone coupons, there were no significant differences in material properties with respect to rib region or rib level. When these results are considered in conjunction with the previous three-point bending tests, there is regional variation in the structural response of the human rib cage, but this variation appears to be primarily a result of changes in the

  17. An Experimental and Analytical Evaluation of a Biaxial Test for Determining Shear Properties of Composite Materials

    NASA Technical Reports Server (NTRS)

    Kennedy, John M.; Barnett, Terry R.

    1988-01-01

    The results of an experimental and analytical investigation of a biaxial tension/compression test for determining shear properties of composite materials are reported. Using finite element models of isotropic and orthotropic laminates, a specimen geometry was optimized. A kinematic fixture was designed to introduce an equal and opposite pair of forces into a specimen with a one inch square test section. Aluminum and several composite laminates with the optimized geometry and a configuration with large stress gradients were tested in the fixture. The specimens were instrumented with strain gages in the center of the test section for shear stiffness measurements. Pure shear strain was measured. The results from the experiments correlated well with finite element results. Failure of the specimens occurred through the center of the test section and appeared to have initiated at the high stress points. The results lead to the conclusion that the optimized specimen is suitable for determining shear modulus for composite materials. Further revisions to the specimen geometry are necessary if the method is to give shear strength data.

  18. Teaching Acoustic Properties of Materials in Secondary School: Testing Sound Insulators

    ERIC Educational Resources Information Center

    Hernandez, M. I.; Couso, D.; Pinto, R.

    2011-01-01

    Teaching the acoustic properties of materials is a good way to teach physics concepts, extending them into the technological arena related to materials science. This article describes an innovative approach for teaching sound and acoustics in combination with sound insulating materials in secondary school (15-16-year-old students). Concerning the…

  19. Human Annulus Fibrosus Material Properties from Biaxial Testing and Constitutive Modeling are Altered with Degeneration

    PubMed Central

    O’Connell, Grace D.; Sen, Sounok; Elliott, Dawn M.

    2012-01-01

    The annulus fibrosus (AF) of the intervertebral disc undergoes large and multidirectional stresses and strains. Uniaxial tensile tests are limited for measuring AF material properties, because freely contracting edges can prevent fiber stretch and are not representative of in situ boundary conditions. The objectives of this study were to measure human AF biaxial tensile mechanics and to apply and validate a constitutive model to determine material properties. Biaxial tensile tests were performed on samples oriented along the circumferential-axial and the radial-axial directions. Data were fit to a structurally-motivated anisotropic hyperelastic model composed of isotropic extrafibrillar matrix, nonlinear fibers, and fiber-matrix interactions (FMI) normal to the fibers. The validated model was used to simulate shear and uniaxial tensile behavior, to investigate AF structure-function, and to quantify the effect of degeneration. The biaxial stress-strain response was described well by the model (R2>0.9). The model showed that the parameters for fiber nonlinearity and the normal FMI correlated with degeneration, resulting in an elongated toe region and lower stiffness with degeneration. The model simulations in shear and uniaxial tension successfully matched previously published circumferential direction Young’s modulus, provided an explanation for the low values in previously published axial direction Young’s modulus, and was able to simulate shear mechanics. The normal FMI were important contributors to stress and changed with degeneration, therefore, their microstructural and compositional source should be investigated. Finally, the biaxial mechanical data and constitutive model can be incorporated into a disc finite element model to provide improved quantification of disc mechanics. PMID:21748426

  20. Investigation of test methods, material properties and processes for solar cell encapsulants

    NASA Technical Reports Server (NTRS)

    Willis, P. B.; Baum, B.

    1977-01-01

    The potentially useful encapsulating materials for Task 3 of the Low-Cost Silicon Solar Array project were studied to identify, evaluate, and recommend encapsulant materials and processes for the production of cost-effective, long-life solar cell modules. Materials for study were chosen on the basis of existing knowledge of generic chemical types having high resistance to environmental weathering. The materials varied from rubbers to thermoplastics and presented a broad range of mechanical properties and processing requirements. Basic physical and optical properties were measured on the polymers and were redetermined after exposure to indoor artificial accelerated aging conditions covering four time periods. Strengths and weaknesses of the various materials were revealed and data was accumulated for the development of predictive methodologies. To date, silicone rubbers, fluorocarbons, and acrylic polymers appear to have the most promising combination of characteristics. The fluorocarbons may be used only as films, however, because of their high cost.

  1. Investigation of test methods, material properties, and processes for solar cell encapsulants

    NASA Technical Reports Server (NTRS)

    Willis, P. B.

    1983-01-01

    A study of potentially useful low cost encapsulation materials for the Flat-Plate Solar Array project is discussed. The goal is to identify, evaluate, test and recommend encapsulant materials and processes for the production of cost-effective, long life solar cell modules. Technical investigations included studies of aging and degradation of candidate encapsulation materials, continued identification of primers for durable bonding of module interfaces, continued evaluation of soil resistant treatments for the sunlit surface of the module and testing of corrosion protective coatings for use low cost mild steel substrates.

  2. Mechanical properties test data for structural materials. Semiannual progress report for period ending July 31, 1980

    SciTech Connect

    Keiser, D.D.

    1980-01-01

    Mechanical property investigations of Alloy 718 given either the 954/sup 0/C conventional or the INEL heat treatment are continuing. Current conventional heat-treat data include tests showing the effects of surface finish, product variability, and thermal exposure on the high-cycle fatigue properties; creep-fatigue tests at 538, 593, 649, and 704/sup 0/C with 0.1 hour hold times at peak strain; and stress-rupture tests of notched and smooth specimens showing the effect of pretest thermal exposure. A few stress-rupture tests of weld and base metals given the INEL heat treatment are also reported. High-cycle fatigue tests of Type 316 stainless steel at 593/sup 0/C are reported and compared with previous data from other sources.

  3. Investigation of test methods, material properties and processes for solar cell encapsulants

    NASA Technical Reports Server (NTRS)

    Willis, P. B.; Baum, B.

    1983-01-01

    Low cost encapsulation materials for the Flat Plate Solar Array Program (FSA) are investigated. The goal of the program is to identify, test, evaluate and recommend encapsulation materials and processes for the fabrication of cost effective and long life solar modules. Accelerated aging techniques for module component lifetime studies, investigation of candidate outer cover films and continued evaluation of soil repellant coatings are also included.

  4. Properties of precipitation hardened steel irradiated at 323 K in the Japan materials testing reactor

    NASA Astrophysics Data System (ADS)

    Niimi, M.; Matsui, Y.; Jitsukawa, S.; Hoshiya, T.; Tsukada, T.; Ohmi, M.; Mimura, H.; Ooka, N.; Hide, K.

    A precipitation hardening type 630 stainless steel was irradiated in the Japan Materials Testing Reactor (JMTR) in contact with the reactor primary coolant. The temperature of the irradiated specimens was about 330 K. The fast neutron ( E > 1 MeV) fluence for the specimens ranged from 10 24 to 10 26 m -2. Tension tests and fracture toughness tests were carried out at room temperature, while Charpy impact tests were done at temperatures of 273-453 K. Tensile strength data showed a peak of 1600 MPa at around 7 × 10 24 m -2, then gradually decreased to about 1500 MPa at 1.2 × 10 26 m -2. The elongation decreased with irradiation from 12% for unirradiated material to 6% at 1.2 × 10 26 m -2. The fractography after the tension test revealed that the fracture was ductile. Fracture toughness decreased to about a half of the value for unirradiated material with irradiation. The cleavage fracture was dominant on the fractured surface. Charpy impact tests showed an increase of ductile-brittle transition temperature (DBTT) by 60 K with irradiation.

  5. Investigation of test methods, material properties and processes for solar cell encapsulants

    NASA Astrophysics Data System (ADS)

    Willis, P.; Baum, B.

    1982-07-01

    The evaluation of potentially useful low cost encapsulation materials is discussed. The goal is to identify, evaluate, test and recommend encapsulant materials and processes for the production of cost effective, long life solar cell modules. Technical investigations concerned the development of advanced cure chemistries for lamination type pottants; the continued evaluation of soil resistant surface treatment, and the results of an accelerated aging test program for the comparison of material stabilities. New compounds were evaluated for efficiency in curing both ethylene/vinyl acetate and ethylene/methyl acrylate pottants intended for vacuum bag lamination of solar cells. Two component aliphatic urethane casting syrups were evaluated for suitability as solar module pottants on the basis of optical, physical and fabrication characteristics.

  6. Investigation of Test Methods, Material Properties and Processes for Solar Cell Encapsulants

    NASA Technical Reports Server (NTRS)

    Willis, P.; Baum, B.

    1982-01-01

    The evaluation of potentially useful low cost encapsulation materials is discussed. The goal is to identify, evaluate, test and recommend encapsulant materials and processes for the production of cost effective, long life solar cell modules. Technical investigations concerned the development of advanced cure chemistries for lamination type pottants; the continued evaluation of soil resistant surface treatment, and the results of an accelerated aging test program for the comparison of material stabilities. New compounds were evaluated for efficiency in curing both ethylene/vinyl acetate and ethylene/methyl acrylate pottants intended for vacuum bag lamination of solar cells. Two component aliphatic urethane casting syrups were evaluated for suitability as solar module pottants on the basis of optical, physical and fabrication characteristics.

  7. Mechanical properties testing of candidate polymer matrix materials for use in high performance composites

    NASA Technical Reports Server (NTRS)

    Zimmerman, R. S.; Adams, D. F.

    1985-01-01

    The mechanical properties of four candidate neat resin systems for use in graphite/epoxy composites are characterized. This includes tensile and shear stiffnesses and strengths, coefficients of thermal and moisture expansion, and fracture toughness. Tests are conducted on specimens in the dry state and moisture-saturated, at temperatures of 23C, 82C and 121C. The neat resins tested are Hexcel HX-1504, Narmco 5245-C, American Cyanamid CYCOM 907, and Union Carbide ERX-4901A (MDA). Results are compared with those obtained for four other epoxy resins tested in a prior program, i.e., Hercules 3502, 2220-1, and 2220-3, and Ciba-Geigy Fibredux 914, as well as with available Hercules 3501-6 data. Scanning electron microscopic examination of fracture surfaces is performed to permit the correlation of observed failure modes with the environmental test conditions. A finite element micromechanics analysis is used to predict unidirectional composite response under various test conditions, using the measured neat resin properties as input data.

  8. Investigation of test methods, material properties, and processes for solar cell encapsulants. Seventh annual report

    SciTech Connect

    Willis, P.B.

    1983-01-01

    The goal of the program is to identify and evaluate encapsulation materials and processes for the protection of silicon solar cells for service in a terrestrial environment. Aging and degradation studies were performed including: thermal aging, sunlamp exposures, aging in controlled environment reactors and outdoor photothermal aging devices, and metal catalyzed degradation. Other tests addressed water absorption, primers and adhesives, soiling experiments, and corrosion protection. (LEW)

  9. Investigation of test methods, material properties, and processes for solar-cell encapsulants. Annual report

    SciTech Connect

    Willis, P. B.; Baum, B.

    1982-07-01

    Potentially useful low cost encapsulation materials are evaluated. The goal of the program is to identify, evaluate, test, and recommend encapsulant materials and processes for the production of cost-effective, long life solar cell modules. Technical investigations have concerned the development of advanced cure chemistries for lamination type pottants, the continued evaluation of soil resistant surface treatments, and the results of an accelerated aging test program for the comparison of material stabilities. Experiments are underway to assess the durability and cost effectiveness of coatings for protection of steel. Investigations are continuing with commercial maintenance coatings based on fluorocarbon and silicone-alkyd chemistries. Experiments were conducted to determine the effectiveness of occlusive coatings for wood products such as hard-board. An experimental program continued to determine the usefulness of soil resistant coatings. Primers were evaluated for effectiveness in bonding candidate pottants to outer covers, glass and substate materials. A program of accelerated aging and life predictive strategies is being conducted and data are reported for sunlamp exposure and thermal aging. Supporting activities are also discussed briefly. (LEW)

  10. Accelerator-based tests of radiation shielding properties of materials used in human space infrastructures.

    PubMed

    Lobascio, C; Briccarello, M; Destefanis, R; Faraud, M; Gialanella, G; Grossi, G; Guarnieri, V; Manti, L; Pugliese, M; Rusek, A; Scampoli, P; Durante, M

    2008-03-01

    Shielding is the only practical countermeasure for the exposure to cosmic radiation during space travel. It is well known that light, hydrogenated materials, such as water and polyethylene, provide the best shielding against space radiation. Kevlar and Nextel are two materials of great interest for spacecraft shielding because of their known ability to protect human space infrastructures from meteoroids and debris. We measured the response to simulated heavy-ion cosmic radiation of these shielding materials and compared it to polyethylene, Lucite (PMMA), and aluminum. As proxy to galactic nuclei we used 1 GeV n iron or titanium ions. Both physics and biology tests were performed. The results show that Kevlar, which is rich in carbon atoms (about 50% in number), is an excellent space radiation shielding material. Physics tests show that its effectiveness is close (80-90%) to that of polyethylene, and biology data suggest that it can reduce the chromosomal damage more efficiently than PMMA. Nextel is less efficient as a radiation shield, and the expected reduction on dose is roughly half that provided by the same mass of polyethylene. Both Kevlar and Nextel are more effective than aluminum in the attenuation of heavy-ion dose. PMID:18301097

  11. Investigation of test methods, material properties and processes for solar cell encapsulants

    NASA Technical Reports Server (NTRS)

    Willis, P. B.

    1985-01-01

    The historical development of ethylene vinyl acetate (EVA) is presented, including the functional requirements, polymer selection, curing, stabilization, production and module processing. The construction and use of a new method for the accelerated aging of polymers is detailed. The method more closely resembles the conditions that may be encountered in actual module field exposure and additionally may permit service life to be predicted accurately. The use of hardboard as a low cost candidate substrate material is studied. The performance of surface antisoiling treatments useful for imparting a self cleaning property to modules is updated.

  12. Rhenium material properties

    NASA Technical Reports Server (NTRS)

    Biaglow, James A.

    1995-01-01

    Tensile data were obtained from four different types of rhenium at ambient and elevated temperatures. The four types of rhenium included chemical vapor deposition (CVD) and three powder metallurgy (PM) types, i.e., rolled sheet and pressed and sintered bars, with and without hot isostatic pressure (HIP) treatment. Results revealed a wide range of values with ultimate strengths at ambient temperatures varying from 663 MPa for CVD rhenium to 943 MPa for rolled sheet. A similar spread was also obtained for material tested at 1088 K and 1644 K. The wide variance observed with the different materials indicated that the rhenium manufacturing process, material composition and prior handling strongly dictated its properties. In addition to tensile properties, CVD, pressed and sintered material and HIP rhenium successfully completed 100 cycles of low cycle fatigue. Creep data were also obtained showing that CVD and pressed and sintered rhenium could sustain five hours of testing under a tension of 27.5 MPa at 1922 K.

  13. Rhenium material properties

    SciTech Connect

    Biaglow, J.A.

    1995-09-01

    Tensile data were obtained from four different types of rhenium at ambient and elevated temperatures. The four types of rhenium included chemical vapor deposition (CVD) and three powder metallurgy (PM) types, i.e., rolled sheet and pressed and sintered bars, with and without hot isostatic pressure (HIP) treatment. Results revealed a wide range of values with ultimate strengths at ambient temperatures varying from 663 MPa for CVD rhenium to 943 MPa for rolled sheet. A similar spread was also obtained for material tested at 1088 K and 1644 K. The wide variance observed with the different materials indicated that the rhenium manufacturing process, material composition and prior handling strongly dictated its properties. In addition to tensile properties, CVD, pressed and sintered material and HIP rhenium successfully completed 100 cycles of low cycle fatigue. Creep data were also obtained showing that CVD and pressed and sintered rhenium could sustain five hours of testing under a tension of 27.5 MPa at 1922 K.

  14. Materials Test Branch

    NASA Technical Reports Server (NTRS)

    Gordon, Gail

    2012-01-01

    The Materials Test Branch resides at Marshall Space Flight Center's Materials and Processing laboratory and has a long history of supporting NASA programs from Mercury to the recently retired Space Shuttle. The Materials Test Branch supports its customers by supplying materials testing expertise in a wide range of applications. The Materials Test Branch is divided into three Teams, The Chemistry Team, The Tribology Team and the Mechanical Test Team. Our mission and goal is to provide world-class engineering excellence in materials testing with a special emphasis on customer service.

  15. Materials property measurements

    SciTech Connect

    Boyd, D.M.; Green, E.R.; Doctor, S.R.; Good, M.S.

    1990-04-19

    An in-depth review of the measurement techniques that could be used in materials characterization is presented. The measurement techniques to non-destructively determine the in-service or time-related aging of materials considered include ultrasonic velocity and attenuation, eddy current conductivity, neutron scattering and absorption, conventional and tomographic imaging for ultrasonic and radiation imaging, x-ray scattering, thermal impedance, and magnetic hysteresis. The three sections of the report include a review of failure mechanisms in steel and a discussion of nondestructive evaluation techniques and fracture mechanics, a description of a chart on Measurement Techniques versus Material Properties, and recommendations on the techniques and tests to be performed for the experimental investigations and analysis task of the project. 49 refs., 7 figs.

  16. Investigation of test methods, material properties and processes for solar cell encapsulants

    NASA Technical Reports Server (NTRS)

    Willis, P. B.; Baum, B.

    1983-01-01

    The goal of the program is to identify, test, evaluate and recommend encapsulation materials and processes for the fabrication of cost-effective and long life solar modules. Of the $18 (1948 $) per square meter allocated for the encapsulation components approximately 50% of the cost ($9/sq m) may be taken by the load bearing component. Due to the proportionally high cost of this element, lower costing materials were investigated. Wood based products were found to be the lowest costing structural materials for module construction, however, they require protection from rainwater and humidity in order to acquire dimensional stability. The cost of a wood product based substrate must, therefore, include raw material costs plus the cost of additional processing to impart hygroscopic inertness. This protection is provided by a two step, or split process in which a flexible laminate containing the cell string is prepared, first in a vacuum process and then adhesively attached with a back cover film to the hardboard in a subsequent step.

  17. Testing of Replacement Bag Material

    SciTech Connect

    Laurinat, J.E.

    1998-11-03

    Recently, the FB-Line bagout material was changed to simplify the processing of sand, slag, and crucible.The results of the strength tests and the outgassing measurements and calculations demonstrate that the proposed replacement nylon bag materials (HRMP and orange anti-static material) are acceptable substitutes for LDPE and the original nylon with respect to mechanical properties.

  18. Investigation of test methods, material properties, and processes for solar cell encapsulants

    NASA Technical Reports Server (NTRS)

    Willis, P. B.

    1985-01-01

    Progress in solar energy technology is reported in the following areas: aging and life prediction methodology and devices for solar cell encapsulation; the function of adhesion chemistry, primers, and a new diagnostic technique for estimations of bond durability; a study of fire retardant formulations for decreasing the potential flammability of solar modules; initial studies of the electrical insulating properties of encapsulation materials and measurement of the intrinsic dielectric strength; antisoiling compounds for the prevention of soil build-up on the outer surface of the module; and low temperature processing encapsulants that permit module fabrication at temperatures less than 100 C. Another area of study has been added to determine the degree to which formulation and processes affect the module quality and manufacturing yield.

  19. Investigation of test methods, material properties, and processes for solar cell encapsulants. Ninth annual report

    SciTech Connect

    Willis, P.B.

    1985-01-01

    Progress is reported in the areas of: aging and life prediction methodology and devices for solar cell encapsulation; the function of adhesion chemistry, primers, and a new diagnostic technique for estimations of bond durability; a study of fire retardant formulations for decreasing the potential flammability of solar modules; initial studies of the electrical insulating properties of encapsulation materials and measurement of the intrinsic dielectric strength; anti-soiling compounds for the prevention of soil build-up on the outer surface of the module; and low temperature processing encapsulants that permit module fabrication at temperatures less than 100/sup 0/C. Another area of study has been added to determine the degree to which formulation and processes affect the module quality and manufacturing yield.

  20. Thermo-Optical and Mechanical Property Testing of Candidate Solar Sail Materials

    NASA Technical Reports Server (NTRS)

    Hollerman, WIlliam A.; Stanaland, T. L.; Womack, F.; Edwards, David; Hubbs, Whitney; Semmel, Charles

    2003-01-01

    Solar sailing is a unique form of propulsion where a spacecraft gains momentum from incident photons. Since sails are not limited by reaction mass, they provide continual acceleration, reduced only by the lifetime of the lightweight film in the space environment and the distance to the Sun. Practical solar sails can expand the number of possible missions, enabling new concepts that are difficult by conventional means. The National Aeronautics and Space Administration's Marshall Space Flight Center (MSFC) is concentrating research into the utilization of ultra-lightweight materials for spacecraft propulsion. Solar sails are generally composed of a highly reflective metallic front layer, a thin polymeric substrate, and occasionally a highly emissive back surface. The Space Environmental Effects Team at MSFC is actively characterizing candidate sails to evaluate the thermo-optical and mechanical properties after exposure to electrons. This poster will discuss the preliminary results of this research.

  1. Composite Material Mirror Testing

    NASA Technical Reports Server (NTRS)

    2000-01-01

    In this photograph, the composite material mirror is tested in the X-Ray Calibration Facility at the Marshall Space Flight Center for the James Webb Space Telescope (JWST). The mirror test conducted was to check the ability to accurately model and predict the cryogenic performance of complex mirror systems, and the characterization of cryogenic dampening properties of beryllium. The JWST, a next generation successor to the Hubble Space Telescope (HST), was named in honor of James W. Webb, NASA's second administrator, who led NASA in the early days of the fledgling Aerospace Agency. Scheduled for launch in 2010 aboard an expendable launch vehicle, the JWST will be able to look deeper into the universe than the HST because of the increased light-collecting power of its larger mirror and the extraordinary sensitivity of its instrument to infrared light.

  2. Ultrasonic material property determinations

    NASA Technical Reports Server (NTRS)

    Serabian, S.

    1986-01-01

    The use and potential offered by ultrasonic velocity and attenuation measurements to determine and/or monitor material properties is explored. The basis for such unique measurements along with examples of materials from a variety of industries are presented.

  3. Investigation of test methods, material properties, and processes for solar cell encapsulants

    NASA Astrophysics Data System (ADS)

    Willis, P. B.

    1982-04-01

    Technical investigations concerned the development of advanced cure chemistries for lamination type pottants; the continued evaluation of soil resistant surface treatments, and the results of an accelerated aging test program for the comparison of material stabilities. New compounds were evaluated for efficiency in curing both ethylene/vinyl acetate and ethylene/methyl acrylate pottants intended for vacuum bag lamination of solar cells. One compound in particular, designated Lupersol - TBEC (Lucidol Division of Pennwalt Corp.) was found to be unusually effective in promoting the rapid cure of both these materials. Formulation of these resins with TBEC resulted in compositions of very high gel content, lower temperatures of activation, and much lower cure times, even in the ethylene/methyl acrylate polymer that is more difficult to cure. It is expected that TBEC modified pottant formulations may permit the lamination/encapsulation step to be operated at lower temperatures, higher speed, higher throughput and a much wider tolerance for intentional or accidental variations in the cure schedule. An experimental program continued to determine the effectiveness of soil resistant coatings.

  4. Investigation of test methods, material properties, and processes for solar cell encapsulants

    NASA Technical Reports Server (NTRS)

    Willis, P. B.

    1982-01-01

    Technical investigations concerned the development of advanced cure chemistries for lamination type pottants; the continued evaluation of soil resistant surface treatments, and the results of an accelerated aging test program for the comparison of material stabilities. New compounds were evaluated for efficiency in curing both ethylene/vinyl acetate and ethylene/methyl acrylate pottants intended for vacuum bag lamination of solar cells. One compound in particular, designated Lupersol - TBEC (Lucidol Division of Pennwalt Corp.) was found to be unusually effective in promoting the rapid cure of both these materials. Formulation of these resins with TBEC resulted in compositions of very high gel content, lower temperatures of activation, and much lower cure times, even in the ethylene/methyl acrylate polymer that is more difficult to cure. It is expected that TBEC modified pottant formulations may permit the lamination/encapsulation step to be operated at lower temperatures, higher speed, higher throughput and a much wider tolerance for intentional or accidental variations in the cure schedule. An experimental program continued to determine the effectiveness of soil resistant coatings.

  5. Test Method To Quantify The Wicking Properties Of Porous Insulation Materials Designed To Prevent Interstitial Condensation

    NASA Astrophysics Data System (ADS)

    Binder, Andrea; Zirkelbach, Daniel; Künzel, Hartwig

    2010-05-01

    Applying an interior insulation often is the only option for a thermal retrofit, especially when heritage buildings are concerned. In doing so, the original construction becomes colder in winter and interstitial condensation may occur. The common way to avoid harmful condensation beneath the interior insulation of the external wall is the installation of a vapor barrier. Since such a barrier works both ways, it may adversely affect the drying potential of the wall during the warmer seasons. One way to avoid the problems described is the installation of an interior insulation system without a vapor barrier to the inside. Here, the effect of capillary transport in porous hydrophilic media is used to conduct condensing moisture away from the wall/insulation interface back to the surface in contact with the indoor air. Following an increasing demand, several water wicking insulation materials (e.g. Calcium-silicate, Autoclave Aerated Concrete based mineral foam, hydrophilic Glass fiber, Cellulose fiber) have appeared on the market. In the past, different methods have been developed to measure and describe the liquid transport properties of hydrophilic porous media. However, the evaluation of the moisture transport mechanisms and their efficiency in this special field of implementation is very complex because of the interacting vapor- and liquid moisture transfer processes. Therefore, there is no consensus yet on its determination and quantification.

  6. Safer Aviation Materials Tested

    NASA Technical Reports Server (NTRS)

    Palaszewski, Bryan A.

    2001-01-01

    A series of thermally stable polymer samples were tested. These materials are called low heat release materials and are designed for aircraft interior decorative materials. The materials are designed to give off a minimum amount of noxious gases when heated, which increases the possibility that people can escape from a burning aircraft. New cabin materials have suitably low heat release so that fire does not spread, toxic chemicals are not given off, and the fire-emergency escape time for crew and passengers is lengthened. These low heat-release materials have a variety of advantages and applications: interiors for ground-based facilities, interiors of space vehicles, and many commercial fire-protection environments. A microscale combustion calorimeter at the Federal Aviation Administration's (FAA) Technical Center tested NASA Langley Research Center materials samples. The calorimeter is shown. A sharp, quantitative, and reproducible heat-release-rate peak is obtained in the microscale heat-release-rate test. The newly tested NASA materials significantly reduced the heat release capacity and total heat release. The thermal stability and flammability behavior of the samples was very good. The new materials demonstrated a factor of 4 reduction in total heat release over ULTEM (a currently used material). This information is provided in the following barchart. In other tests, the materials showed greater than a factor 9 reduction in heat-release capacity over ULTEM. The newly tested materials were developed for low dielectric constant, low color, and good solubility. A scale up of the material samples is needed to determine the repeatability of the performance in larger samples. Larger panels composed of the best candidate materials will be tested in a larger scale FAA Technical Center fire facility. The NASA Glenn Research Center, Langley (Jeff Hinkley), and the FAA Technical Center (Richard Lyon) cooperatively tested these materials for the Accident Mitigation

  7. Building Materials Property Table

    SciTech Connect

    2010-04-16

    This information sheet describes a table of some of the key technical properties of many of the most common building materials taken from ASHRAE Fundamentals - 2001, Moisture Control in Buildings, CMHC, NRC/IRC, IEA Annex 24, and manufacturer data.

  8. Investigation of Test Methods, Material Properties, and Processes for Solar Cell Encapsulants

    NASA Technical Reports Server (NTRS)

    1979-01-01

    During this quarter the technical activities were directed toward the reformulation of ethylene/vinyl acetate copolymer for use as a compound in solar cell module fabrication. Successful formulations were devised that lowered the temperature required for cure and raised the gel content. A major volatile component was also eliminated (acrylate crosslinking agent) which should aid in the production of bubble free laminates. Adhesive strengths and primers for the bonding of ethylene/vinyl acetate to supersyrate and substrate materials was assessed with encouraging results. The incorporation of silane compounds gave high bond strengths. A survey of scrim materials was also conducted.

  9. Flexible Material Systems Testing

    NASA Technical Reports Server (NTRS)

    Lin, John K.; Shook, Lauren S.; Ware, Joanne S.; Welch, Joseph V.

    2010-01-01

    An experimental program has been undertaken to better characterize the stress-strain characteristics of flexible material systems to support a NASA ground test program for inflatable decelerator material technology. A goal of the current study is to investigate experimental methods for the characterization of coated woven material stiffness. This type of experimental mechanics data would eventually be used to define the material inputs of fluid-structure interaction simulation models. The test methodologies chosen for this stress-strain characterization are presented along with the experimental results.

  10. Investigation of test methods, material properties, and processes for solar cell encapsulants

    NASA Technical Reports Server (NTRS)

    Willis, P. B.

    1981-01-01

    Encapsulant materials and processes for the production of cost-effective, long-life solar cell modules were investigated. The following areas were explored: (1) soil resistant surface treatment; (2) corrosion protecting coatings from mild steel substrates; (3) primers for bonding module interfaces; and (4) RS/4 accelerated aging of candidate encapsulation compounds

  11. Investigation of test methods, material properties, and processes for solar cell encapsulants. Annual report

    SciTech Connect

    Willis, P. B.; Baum, B.; Schnitzer, H. S.

    1980-07-01

    The goal of this program is to identify, evaluate, and recommend encapsulant materials and processes for the production of cost-effective, long-life solar cell modules. Technical activities during the past year have covered a number of topics and have emphasized the development of solar module encapsulation technology that employs ethylene/vinyl acetate, copolymer (EVA) as the pottant. These activities have included: (1) continued production of encapsulation grade EVA in sheet form to meet the needs of the photovoltaic industry; (2) investigations of three non-blocking techniques for EVA sheet; (3) performed an economic analysis of the high volume production of each pottant in order to estimate the large volume selling price (EVA, EPDM, aliphatic urethane, PVC plastisol, and butyl acrylate); (4) initiated an experimental corrosion protection program to determine if metal components could be successfully protected by encapsulation; (5) began an investigation to determine the maximum temperature which can be tolerated by the candidate pottant material in the event of hot spot heating or other temperature override; (6) continuation of surveys of potentially useful outer cover materials; and (7) continued with the accelerated artificial weathering of candidate encapsulation materials. Study results are presented. (WHK)

  12. Material Fatigue Testing System

    NASA Technical Reports Server (NTRS)

    Gilley, P. J. (Inventor)

    1973-01-01

    A system for cyclicly applying a varying load to a material under test is described. It includes a load sensor which senses the magnitude of load being applied to a material, and, upon sensing a selected magnitude of loading, causes the load to be maintained for a predetermined time and then cause the system to resume cyclical loading.

  13. Investigation of Test Methods, Material Properties, and Processes for Solar Cell Encapsulants

    NASA Technical Reports Server (NTRS)

    Willis, P. B.

    1981-01-01

    Encapsulant materials and processes for the production of cost effective, long life solar cell modules are identified, and evaluated. Ethylene vinyl acetate lamination pottant studies are conducted with respect to the time/temperature cure requirements for successful use of this compound. The time needed to produce successful gel contents are redetermined at a variety of temperatures and are related to the peroxide half life temperature curve. Formulation of the butyl acrylate syrup casting pottant is complete. The formulation contains an ultraviolet stabilizer system and is cured with an initiator that presents no shipping or handling hazards. The catalyzed syrup is stable at room temperature and has a pot life of at least an eight hour period of time. The syrup cures to a transparent rubber in 18 minutes at a temperature of 60 C.

  14. Investigation of Test Methods, Material Properties, and Processes for Solar Cell Encapsulents

    NASA Technical Reports Server (NTRS)

    1978-01-01

    The technical activities were directed toward the assessment of encapsulation processes for use with ethylene/vinyl acetate copolymer as the pottant. Potentially successful formulations were prepared by compounding the raw polymer with ultraviolet absorbers and crosslinking agents to give stabilized and curable compositions. The compounded resin was then converted to a more useful form with an extruder to give pottant in sheets that could be more easily used in lamination. After experimenting with various techniques, the vacuum-bag process was found to be an excellent encapsulation method. Miniature single-celled and multi-celled solar modules of both substrate and superstrate designs were prepared by this technique. The resulting modules were of good appearance, were bubble-free, and successfully passed the thermal cycle test.

  15. Material Properties Test to Determine Ultimate Strain and True Stress-True Strain Curves for High Yield Steels

    SciTech Connect

    K.R. Arpin; T.F. Trimble

    2003-04-01

    This testing was undertaken to develop material true stress-true strain curves for elastic-plastic material behavior for use in performing transient analysis. Based on the conclusions of this test, the true stress-true strain curves derived herein are valid for use in elastic-plastic finite element analysis for structures fabricated from these materials. In addition, for the materials tested herein, the ultimate strain values are greater than those values cited as the limits for the elastic-plastic strain acceptance criteria for transient analysis.

  16. Assessment of Technologies for the Space Shuttle External Tank Thermal Protection System and Recommendations for Technology Improvement - Part III: Material Property Characterization, Analysis, and Test Methods

    NASA Technical Reports Server (NTRS)

    Gates, Thomas S.; Johnson, Theodore F.; Whitley, Karen S.

    2005-01-01

    The objective of this report is to contribute to the independent assessment of the Space Shuttle External Tank Foam Material. This report specifically addresses material modeling, characterization testing, data reduction methods, and data pedigree. A brief description of the External Tank foam materials, locations, and standard failure modes is provided to develop suitable background information. A review of mechanics based analysis methods from the open literature is used to provide an assessment of the state-of-the-art in material modeling of closed cell foams. Further, this report assesses the existing material property database and investigates sources of material property variability. The report presents identified deficiencies in testing methods and procedures, recommendations for additional testing as required, identification of near-term improvements that should be pursued, and long-term capabilities or enhancements that should be developed.

  17. Experimental tests of irradiation-anneal-reirradiation effects on mechanical properties of RPV plate and weld materials

    SciTech Connect

    Hawthorne, J.R.

    1996-01-01

    The Charpy-V (C{sub V}) notch ductility and tension test properties of three reactor pressure vessel (RPV) steel materials were determined for the 288{degree}C (550{degree}F) irradiated (I), 288{degree}C (550{degree}F) irradiated + 454{degree}C (850{degree}F)-168 h postirradiation annealed (IA), and 288{degree}C (550{degree}F) reirradiated (IAR) conditions. Total fluences of the I condition and the IAR condition were, respectively, 3.33 {times} 10{sup 19} n/cm{sup 2} and 4.18 {times} 10{sup 19} n/cm{sup 2}, E > 1 MeV. The irradiation portion of the IAR condition represents an incremental fluence increase of 1. 05 {times} 10{sup 19} n/cm{sup 2}, E > 1 MeV, over the I-condition fluence. The materials (specimens) were supplied by the Yankee Atomic Electric Company and represented high and low nickel content plates and a high nickel, high copper content weld deposit prototypical of the Yankee-Rowe reactor vessel. The promise of the IAR method for extending the fluence tolerance of radiation-sensitive steels and welds is clearly shown by the results. The annealing treatment produced full C{sub V} upper shelf recovery and full or nearly full recovery in the C{sub V} 41 J (30 ft-lb) transition temperature. The C{sub V} transition temperature increases produced by the reirradiation exposure were 22% to 43% of the increase produced by the first cycle irradiation exposure. A somewhat greater radiation embrittlement sensitivity and a somewhat greater reirradiation embrittlement sensitivity was exhibited by the low nickel content plate than the high nickel content plate. Its high phosphorus content is believed to be responsible. The IAR-condition properties of the surface vs. interior regions of the low nickel content plate are also compared.

  18. Testing Requirements for Refractory Materials

    NASA Technical Reports Server (NTRS)

    Calle, Luz Marina; Hintze, Paul E.; Parlier, Christopher R.; Curran, Jerome P.; Kolody, Mark R.; Sampson, Jeffrey W,; Montgomery, Eliza M.

    2012-01-01

    Launch Pads 39A and 39B currently use refractory material (Fondu Fyre) in the flame trenches. This material was initially approved for the Saturn program. This material had a lifetime of 10years according to the manufacturer, and it has been used for over 40 years. As a consequence, the Fondu Fyre at Launch Complex 39 requires repair subsequent to almost every launch. A review of the literature indicates that the gunned Fondu Fyre refractory product (WA-1 G) was never tested prior to use. With the recent severe damage to the flame trenches, a new refractory material is sought to replace Fondu Fyre. In order to replace Fondu Fyre, a methodology to test and evaluate refractory products was developed. This paper outlines this methodology and discusses current testing requirements, as well as the laboratory testing that might be required. Furthermore, this report points out the necessity for subscale testing, the locations where this testing can be performed, and the parameters that will be necessary to qualify a product. The goal is to identify a more durable refractory material that has physical, chemical, and thermal properties suitable to withstand the harsh environment of the launch pads at KSC.

  19. Testing Requirements for Refractory Materials

    NASA Technical Reports Server (NTRS)

    Calle, Luz Marina; Hintze, Paul E.; Parlier, Christopher R.; Curran, Jerome P.; Kolody, Mark R.; Sampson, Jeffrey W.; Montgomery, Eliza M.

    2011-01-01

    Launch Pads 39A and 39B currently use refractory material (Fondu Fyre) in the flame trenches. This material was initially approved for the Saturn program. This material had a lifetime of 10 years according to the manufacturer, and it has been used for over 40 years. As a consequence, the Fondu Fyre at Launch Complex 39 requires repair subsequent to almost every launch. A review of the literature indicates that the gunned Fondu Fyre refractory product (WA-1G) was never tested prior to use. With the recent severe damage to the flame trenches, a new refractory material is sought to replace Fondu Fyre. In order to replace Fondu Fyre, a methodology to test and evaluate refractory products was developed. This paper outlines this methodology and discusses current testing requirements, as well as the laboratory testing that might be required. Furthermore, this report points out the necessity for subscale testing, the locations where this testing can be performed, and the parameters that will be necessary to qualify a product. The goal is to identify a more durable refractory material that has physical, chemical, and thermal properties suitable to withstand the harsh environment of the launch pads at KSC.

  20. Testing Requirements for Refractory Materials

    NASA Technical Reports Server (NTRS)

    Calle, Luz Marina; Hintze, Paul E.; Parlier, Christopher R.; Curran, Jerome P.; Kolody, Mark R.; Sampson, Jeffrey W.; Montgomery, Eliza M.

    2010-01-01

    Launch Pads 39A and 39B currently use refractory material (Fondu Fyre) in the flame trenches. This material was initially approved for the Saturn program. This material had a lifetime of 10 years according to the manufacturer, and it has been used for over 40 years. As a consequence, the Fondu Fyre at Launch Complex 39 requires repair subsequent to almost every launch. A review of the literature indicates that the gunned Fondu Fyre refractory product (WA-1G) was never tested prior to use. With the recent severe damage to the flame trenches, a new refractory material is sought to replace Fondu Fyre. In order to replace Fondu Fyre, a methodology to test and evaluate refractory products was developed. This paper outlines this methodology and discusses current testing requirements, as well as the laboratory testing that might be required. Furthermore, this report points out the necessity for subscale testing, the locations where this testing can be performed, and the parameters that will be necessary to qualify a product. The goal is to identify a more durable refractory material that has physical, chemical, and thermal properties suitable to withstand the harsh environment of the launch pads at KSC.

  1. Material Testing Device

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Small Business Innovation Research (SBIR) contracts led to two commercial instruments and a new subsidiary for Physical Sciences, Inc. (PSI). The FAST system, originally developed for testing the effect of space environment on materials, is now sold commercially for use in aging certification of materials intended for orbital operation. The Optical Temperature Monitor was designed for precise measurement of high temperatures on certain materials to be manufactured in space. The original research was extended to the development of a commercial instrument that measures and controls fuel gas temperatures in industrial boilers. PSI created PSI Environmental Instruments to market the system. The company also offers an Aerospace Measurement Service that has evolved from other SBIR contracts.

  2. Celotex Structural Properties Tests

    SciTech Connect

    Smith, A.C.

    2001-01-26

    In the course of regulatory review of the 9975 packaging, the question of the effects environmental conditions on performance of the packaging was raised. The results of previous tests of the Celotex material, used for impact absorption and thermal insulation, indicated that the effect of temperature variation was small. Accordingly, performance under ambient conditions was judged to be representative of performance under temperature extremes. To extend the database to include other effects, and in response to the questions, a series of materials tests were performed on the Celotex brand cellulose fiberboard material.

  3. Reviews of Test Materials.

    ERIC Educational Resources Information Center

    Mullen, Jo-Ann

    1981-01-01

    Reviews four standardized tests geared to helping development educators in placing students in courses and assessing their learning levels: the Davis Reading Test; the Descriptive Tests of Language Skills; the Descriptive Tests of Mathematics Skills; and the Nelson-Denny Reading Test. (CAM)

  4. Material testing of silicon carbide mirrors

    NASA Astrophysics Data System (ADS)

    Witkin, David B.; Palusinski, Iwona A.

    2009-08-01

    The Aerospace Corporation is developing a space qualification method for silicon carbide optical systems that covers material verification through system development. One of the initial efforts has been to establish testing protocols for material properties. Three different tests have been performed to determine mechanical properties of SiC: modulus of rupture, equibiaxial flexural strength and fracture toughness. Testing materials and methods have been in accordance with the respective ASTM standards. Material from four vendors has been tested to date, as part of the MISSE flight program and other programs. Data analysis has focused on the types of issues that are important when building actual components- statistical modeling of test results, understanding batch-to-batch or other source material variations, and relating mechanical properties to microstructures. Mechanical properties are needed as inputs to design trade studies and development and analysis of proof tests, and to confirm or understand the results of non-destructive evaluations of the source materials. Measuring these properties using standardized tests on a statistically valid number of samples is intended to increase confidence for purchasers of SiC spacecraft components that materials and structures will perform as intended at the highest level of reliability.

  5. Materials properties data base computerization

    NASA Technical Reports Server (NTRS)

    Baur, R. G.; Donthnier, M. L.; Moran, M. C.; Mortman, I.; Pinter, R. S.

    1984-01-01

    Material property data plays a key role in the design of jet engine components. Consistency, accuracy and efficient use of material property data is of prime importance to the engineering community. The system conception, development, implementation, and future plans for computer software that captures the Material Properties Handbook into a scientific data base are described. The engineering community is given access to raw data and property curves, display of multiple curves for material evaluation and selection, direct access by design analysis computer programs, display of the material specification, and a historical repository for the material evolution. The impact of this activity includes significant productivity gains and cost reductions; all users have access to the same information nd provides consistent, rapid response to the needs of the engineering community. Future plans include incorporating the materials properties data base into a network environment to access information from other data bases and download information to engineering work stations.

  6. 14 CFR 25.613 - Material strength properties and material design values.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... individual item is tested before use to determine that the actual strength properties of that particular item... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Material strength properties and material... § 25.613 Material strength properties and material design values. (a) Material strength properties...

  7. 14 CFR 25.613 - Material strength properties and material design values.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... individual item is tested before use to determine that the actual strength properties of that particular item... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Material strength properties and material... § 25.613 Material strength properties and material design values. (a) Material strength properties...

  8. 14 CFR 25.613 - Material strength properties and material design values.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... individual item is tested before use to determine that the actual strength properties of that particular item... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Material strength properties and material... § 25.613 Material strength properties and material design values. (a) Material strength properties...

  9. 14 CFR 25.613 - Material strength properties and material design values.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... individual item is tested before use to determine that the actual strength properties of that particular item... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Material strength properties and material... § 25.613 Material strength properties and material design values. (a) Material strength properties...

  10. 14 CFR 25.613 - Material strength properties and material design values.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... individual item is tested before use to determine that the actual strength properties of that particular item... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Material strength properties and material... § 25.613 Material strength properties and material design values. (a) Material strength properties...

  11. Long-Term Materials Test Program: materials exposure test plan

    SciTech Connect

    1981-12-01

    The Long Term Materials Test Program is designed to identify promising corrosion resistant materials for coal-fired gas turbine applications. Resistance of materials to long term accelerated corrosion will be determined through realistic PFB environmental exposure of candidate turbine materials for up to 14,000 hours. Selected materials also will be evaluated for their ability to withstand the combined erosive and corrosive aspects of the PFB effluent. A pressurized fluidized bed combustor facility has been constructed at the General Electric Coal Utilization Research Laboratory at Malta, New York. The 12-inch diameter combustor will burn high sulfur coal with moderate-to-high chlorine and alkali levels and utilize dolomite as the sulfur sorbent. Hot gas cleanup is achieved using three stages of cyclone separators. Downstream of the cylone separators, a low velocity test section (approx. 30 ft/s) capable of housing 180 pin specimens 1/4'' diameter has been installed to assess the corrosion resistance of the various materials at three different temperatures ranging from 1300 to 1600/sup 0/F. Following the low velocity test section is a high velocity test section consisting of four cascades of airfoil shaped specimens, six specimens per cascade. This high velocity test section is being used to evaluate the combined effects of erosion and corrosion on the degradation of gas turbine materials at gas velocities of 800 to 1400 ft/s. This report summarizes the materials selection and materials exposure test plan for the Long Term Materials Test.

  12. Design of test specimens and procedures for generating material properties of Douglas fir/epoxy laminated wood composite material: With the generation of baseline data at two environmental conditions

    NASA Technical Reports Server (NTRS)

    Johnson, Paul E.

    1985-01-01

    In support of the design of wind turbine generator airfoils/blades utilizing Douglas Fir/West System Epoxy laminated composite material, a program was undertaken to define pertinent material properties utilizing small scale test specimens. Task 1 was the development of suitable monotonic tension, compression, short beam shear and full reversed cyclic specimen designs and the companion grips and testing procedures. Task 2 was the generation of the material properties at two environmental conditions utilizing the specimens and procedures developed in Task 1. The monotonic specimens and procedures generated results which compare favorably with other investigators while the cyclic results appear somewhat conservative. Adding moisture and heat or scarf joints degraded the monotonic performance but had a more nebulus effect with cyclic loading.

  13. Methods and instruments for materials testing

    NASA Technical Reports Server (NTRS)

    Hansma, Paul (Inventor); Drake, Barney (Inventor); Rehn, Douglas (Inventor); Adams, Jonathan (Inventor); Lulejian, Jason (Inventor)

    2011-01-01

    Methods and instruments for characterizing a material, such as the properties of bone in a living human subject, using a test probe constructed for insertion into the material and a reference probe aligned with the test probe in a housing. The housing is hand held or placed so that the reference probe contacts the surface of the material under pressure applied either by hand or by the weight of the housing. The test probe is inserted into the material to indent the material while maintaining the reference probe substantially under the hand pressure or weight of the housing allowing evaluation of a property of the material related to indentation of the material by the probe. Force can be generated by a voice coil in a magnet structure to the end of which the test probe is connected and supported in the magnet structure by a flexure, opposing flexures, a linear translation stage, or a linear bearing. Optionally, a measurement unit containing the test probe and reference probe is connected to a base unit with a wireless connection, allowing in the field material testing.

  14. Design of materials with prescribed nonlinear properties

    NASA Astrophysics Data System (ADS)

    Wang, F.; Sigmund, O.; Jensen, J. S.

    2014-09-01

    We systematically design materials using topology optimization to achieve prescribed nonlinear properties under finite deformation. Instead of a formal homogenization procedure, a numerical experiment is proposed to evaluate the material performance in longitudinal and transverse tensile tests under finite deformation, i.e. stress-strain relations and Poissons ratio. By minimizing errors between actual and prescribed properties, materials are tailored to achieve the target. Both two dimensional (2D) truss-based and continuum materials are designed with various prescribed nonlinear properties. The numerical examples illustrate optimized materials with rubber-like behavior and also optimized materials with extreme strain-independent Poissons ratio for axial strain intervals of εi∈[0.00, 0.30].

  15. Analytical Ultrasonics in Materials Research and Testing

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1986-01-01

    Research results in analytical ultrasonics for characterizing structural materials from metals and ceramics to composites are presented. General topics covered by the conference included: status and advances in analytical ultrasonics for characterizing material microstructures and mechanical properties; status and prospects for ultrasonic measurements of microdamage, degradation, and underlying morphological factors; status and problems in precision measurements of frequency-dependent velocity and attenuation for materials analysis; procedures and requirements for automated, digital signal acquisition, processing, analysis, and interpretation; incentives for analytical ultrasonics in materials research and materials processing, testing, and inspection; and examples of progress in ultrasonics for interrelating microstructure, mechanical properites, and dynamic response.

  16. Mechanical properties of nanophase materials

    SciTech Connect

    Siegel, R.W.; Fougere, G.E.

    1993-11-01

    It has become possible in recent years to synthesize new materials under controlled conditions with constituent structures on a nanometer size scale (below 100 nm). These novel nanophase materials have grain-size dependent mechanical properties significantly different than those of their coarser-grained counterparts. For example, nanophase metals are much stronger and apparently less ductile than conventional metals, while nanophase ceramics are more ductile and more easily formed than conventional ceramics. The observed mechanical property changes are related to grain size limitations and/or the large percentage of atoms in grain boundary environments; they can also be affected by such features as flaw populations, strains and impurity levels that can result from differing synthesis and processing methods. An overview of what is presently known about the mechanical properties of nanophase materials, including both metals and ceramics, is presented. Some possible atomic mechanisms responsible for the observed behavior in these materials are considered in light of their unique structures.

  17. European tests on materials outgassing

    NASA Technical Reports Server (NTRS)

    Zwaal, A.

    1977-01-01

    With a view to international coordination of spacecraft materials, a number of European firms and institutes performed outgassing tests on identical materials at 125 C in high vacuum. The outgassing data obtained with the different types of equipment is presented and both the results and the critical parameters are discussed.

  18. Property Status of Lunar Material

    NASA Astrophysics Data System (ADS)

    Pop, V.

    Most of the lunar material in private hands is of meteoric origin, and its property sta- tus does not present many challenges. The intention of Applied Space Resources, Inc, to fly a commercial lunar sample return mission and to subsequently offer lunar ma- terial for sale, raises the issue of the legality of exploitation and private ownership of retrieved lunar material. Lunar samples have been returned in the past by means of the Apollo (US) and Luna (USSR) missions and, while most of the material re- mains government property and is used for scientific means, a small fraction has been transferred abroad and some has entered the private market. Apollo-collected moon- rocks have been offered, symbolically, to heads of States, and some foreign nations have subsequently transferred ownership to private individuals. The same, lunar ma- terial of Soviet provenience has entered the private market, this forming a valuable legal precedent for the lawfulness of sale of lunar material. Recently, plans were made public to award the Apollo astronauts with lunar rocks. While in the US there is a popular misconception that it is illegal to own lunar material, the truth lies elsewhere. As the Apollo samples are the property of the US government and a small fraction was stolen, lost, or misplaced, the US government intends to recover this material, unlawfully owned. In the same time, a significant number of individuals have been prosecuted for offering for sale fake lunar rocks. The present paper will analyse the different categories of lunar material according to its ownership status, and will as- sert that private property of lunar material is lawful, and lunar material that will be returned in the future will be able to enter the market without hindrances.

  19. Composite materials: Testing and design

    NASA Technical Reports Server (NTRS)

    Whitcomb, John D. (Editor)

    1988-01-01

    The present conference discusses topics in the analysis of composite structures, composite materials' impact and compression behavior, composite materials characterization methods, composite failure mechanisms, NDE methods for composites, and filament-wound and woven composite materials' fabrication. Attention is given to the automated design of a composite plate for damage tolerance, the effects of adhesive layers on composite laminate impact damage, instability-related delamination growth in thermoset and thermoplastic composites, a simple shear fatigue test for unidirectional E-glass epoxy, the growth of elliptic delaminations in laminates under cyclic transverse shear, and the mechanical behavior of braided composite materials.

  20. Properties of aircraft tire materials

    NASA Technical Reports Server (NTRS)

    Dodge, Richard N.; Clark, Samuel K.

    1988-01-01

    A summary is presented of measured elastomeric composite response suitable for linear structural and thermoelastic analysis in aircraft tires. Both real and loss properties are presented for a variety of operating conditions including the effects of temperature and frequency. Suitable micro-mechanics models are used for predictions of these properties for other material combinations and the applicability of laminate theory is discussed relative to measured values.

  1. Functional Properties of Nanostructured Materials

    NASA Astrophysics Data System (ADS)

    Kassing, Rainer; Petkov, Plamen; Kulisch, Wilhelm; Popov, Cyril

    This book, based on the lectures and contributions of the NATO ASI on "Functional Properties of Nanostructured Materials", gives a broad overview on this topic, as it combines basic theoretical articles, papers dealing with experimental techniques, and contributions on advanced and up-to-date applications in fields such as microelectronics, optoelectronics, electrochemistry, sensorics, and biotechnology. In addition, it presents an interdisciplinary approach since the authors came from such different fields as physics, chemistry, engineering, materials science and biology.

  2. Accelerators for Fusion Materials Testing

    NASA Astrophysics Data System (ADS)

    Knaster, Juan; Okumura, Yoshikazu

    Fusion materials research is a worldwide endeavor as old as the parallel one working toward the long term stable confinement of ignited plasma. In a fusion reactor, the preservation of the required minimum thermomechanical properties of the in-vessel components exposed to the severe irradiation and heat flux conditions is an indispensable factor for safe operation; it is also an essential goal for the economic viability of fusion. Energy from fusion power will be extracted from the 14 MeV neutron freed as a product of the deuterium-tritium fusion reactions; thus, this kinetic energy must be absorbed and efficiently evacuated and electricity eventually generated by the conventional methods of a thermal power plant. Worldwide technological efforts to understand the degradation of materials exposed to 14 MeV neutron fluxes >1018 m-2s-1, as expected in future fusion power plants, have been intense over the last four decades. Existing neutron sources can reach suitable dpa (“displacement-per-atom”, the figure of merit to assess materials degradation from being exposed to neutron irradiation), but the differences in the neutron spectrum of fission reactors and spallation sources do not allow one to unravel the physics and to anticipate the degradation of materials exposed to fusion neutrons. Fusion irradiation conditions can be achieved through Li (d, xn) nuclear reactions with suitable deuteron beam current and energy, and an adequate flowing lithium screen. This idea triggered in the late 1970s at Los Alamos National Laboratory (LANL) a campaign working toward the feasibility of continuous wave (CW) high current linacs framed by the Fusion Materials Irradiation Test (FMIT) project. These efforts continued with the Low Energy Demonstrating Accelerator (LEDA) (a validating prototype of the canceled Accelerator Production of Tritium (APT) project), which was proposed in 2002 to the fusion community as a 6.7MeV, 100mA CW beam injector for a Li (d, xn) source to bridge

  3. Accelerators for Fusion Materials Testing

    NASA Astrophysics Data System (ADS)

    Knaster, Juan; Okumura, Yoshikazu

    Fusion materials research is a worldwide endeavor as old as the parallel one working toward the long term stable confinement of ignited plasma. In a fusion reactor, the preservation of the required minimum thermomechanical properties of the in-vessel components exposed to the severe irradiation and heat flux conditions is an indispensable factor for safe operation; it is also an essential goal for the economic viability of fusion. Energy from fusion power will be extracted from the 14 MeV neutron freed as a product of the deuterium-tritium fusion reactions; thus, this kinetic energy must be absorbed and efficiently evacuated and electricity eventually generated by the conventional methods of a thermal power plant. Worldwide technological efforts to understand the degradation of materials exposed to 14 MeV neutron fluxes > 1018 m-2s-1, as expected in future fusion power plants, have been intense over the last four decades. Existing neutron sources can reach suitable dpa ("displacement-per-atom", the figure of merit to assess materials degradation from being exposed to neutron irradiation), but the differences in the neutron spectrum of fission reactors and spallation sources do not allow one to unravel the physics and to anticipate the degradation of materials exposed to fusion neutrons. Fusion irradiation conditions can be achieved through Li (d, xn) nuclear reactions with suitable deuteron beam current and energy, and an adequate flowing lithium screen. This idea triggered in the late 1970s at Los Alamos National Laboratory (LANL) a campaign working toward the feasibility of continuous wave (CW) high current linacs framed by the Fusion Materials Irradiation Test (FMIT) project. These efforts continued with the Low Energy Demonstrating Accelerator (LEDA) (a validating prototype of the canceled Accelerator Production of Tritium (APT) project), which was proposed in 2002 to the fusion community as a 6.7MeV, 100mA CW beam injector for a Li (d, xn) source to bridge

  4. Materials Properties Research at MSFC

    NASA Technical Reports Server (NTRS)

    Presson, Joan B.; Burdine, Robert (Technical Monitor)

    2002-01-01

    MSFC is currently planning, organizing and directing test coupon fabrication and subsequent CTE testing for two mirror materials of specific interest to the AMSD and NGST programs, Beryllium 0-30H (Be 0-30H) and Ultra Low Expansion glass (ULE). The ULE test coupons are being fabricated at MSFC from AMSD core residuals provided by Kodak, The Be 0-30H test coupons are being fabricated at Brush Wellman using residuals from the SBMD. Both sets of test coupons will be sent to a test vendor selected through the NASA competitive proposal process with the test results being provided by written report to MSFC by the end of the fiscal year. The test results will become model input data for the AMSD analysts, both MSFC and contractor, providing an enhancement to the historical CTE data currently available.

  5. Satellite material contaminant optical properties

    NASA Technical Reports Server (NTRS)

    Wood, B. E.; Bertrand, W. T.; Seiber, B. L.; Kiech, E. L.; Falco, P. M.; Holt, J. D.

    1990-01-01

    The Air Force Wright Research and Development Center and the Arnold Engineering Development Center are continuing a program for measuring optical effects of satellite material outgassing products on cryo-optic surfaces. Presented here are infrared (4000 to 700 cm(-1)) transmittance data for contaminant films condensed on a 77 K geranium window. From the transmittance data, the contaminant film refractive and absorptive indices (n, k) were derived using an analytical thin-film interference model with a nonlinear least-squares algorithm. To date 19 materials have been studied with the optical contents determined for 13 of those. The materials include adhesives, paints, composites, films, and lubricants. This program is continuing and properties for other materials will be available in the future.

  6. Dynamic properties of ceramic materials

    SciTech Connect

    Grady, D.E.; Wise, J.L.

    1993-09-01

    Controlled impact methods have been employed to obtain dynamic response properties of armor materials. Experimental data have been obtained for high-strength ceramics. Continued analysis of time-resolved velocity interferometer measurements has produced systematic material-property data for Hugoniot and release response, initial and post-yield strength, pressure-induced phase transformation, and dynamic fracture strength. A new technique has been developed to measure hydrodynamic properties of ceramic through shock-wave experiments on metal-ceramic composites and data obtained for silicon carbide. Additional data on several titanium diboride ceramics and high-quality aluminum oxide ceramic have been acquired, and issues regarding the influence of microstructure on dynamic properties have emerged. Comparison of dynamic (Hugoniot elastic limit) strength and indentation hardness data has been performed and important correlations revealed. Innovative impact experiments on confined and unconfined alumina rods using axial and transverse VISAR diagnostics have been demonstrated which permit acquisition of multiaxial dynamic response data. Dynamic failure properties of a high-density aluminosilicate glass, similar in composition to the intergranular glassy phase of some aluminas, have been investigated with regard to yield, spall, and failure-wave propagation.

  7. Electrostatic testing of thin plastic materials

    NASA Technical Reports Server (NTRS)

    Skinner, S. Ballou

    1988-01-01

    Ten thin plastic materials (Velostat, RCAS 1200, Llumalloy, Herculite 80, RCAS 2400, Wrightlon 7000, PVC, Aclar 22A, Mylar, and Polyethylene) were tested for electrostatic properties by four different devices: (1) The static decay meter, (2) the manual triboelectric testing device, (3) the robotic triboelectric testing device, and (4) the resistivity measurement adapter device. The static decay meter measured the electrostatic decay rates in accordance with the Federal Test Method Standard 101B, Method 4046. The manual and the robotic triboelectric devices measured the triboelectric generated peak voltages and the five-second decay voltages in accordance with the criteria for acceptance standards at Kennedy Space Center. The resistivity measurement adapter measured the surface resistivity of each material. An analysis was made to correlate the data among the four testing devices. For the material tested the pass/fail results were compared for the 4046 method and the triboelectric testing devices. For the limited number of materials tested, the relationship between decay rate and surface resistivity was investigated as well as the relationship between triboelectric peak voltage and surface resistivity.

  8. Material properties of oxide superconductors

    SciTech Connect

    Phillips, J.C.

    1996-12-31

    The differences between the old (inter-) metallic superconductors and the new oxide superconductors are not limited to the much higher values of {Tc} attainable in the latter. There are many pervasive differences caused directly by oxide chemistry, quasi-perovskite local coordination configurations, and layered metal-semiconductor-metal{prime}-semiconductor-structures. When these differences are ignored, for instance in theoretical models which make effective medium approximations, many experiments appear to present anomalous results. These anomalies largely disappear when account is taken of the real materials properties of the cuprates and other new oxide superconductors, for instance in theoretical models which treat transport as a partially percolative process. This percolative process directly reflects the fact that the highest values of {Tc}, as well as the most anomalous normal-state transport properties, occur in materials vicinal to a metal-insulator transition. As the metallic and insulating regions alternate even in single-crystal samples, effective medium models, and most effective-medium parameters, lose their significance. Examples of attempts to measure microscopic properties illustrate the importance of filamentary effects on both normal-state and superconductive properties.

  9. Radioactive material packaging performance testing

    SciTech Connect

    Romano, T.

    1992-06-01

    In an effort to provide uniform packaging of hazardous material on an international level, recommendations for the transport of dangerous goods have been developed by the United Nations. These recommendations are performance oriented and contrast with a large number of packaging specifications in the US Department of Transportation's hazard materials regulations. This dual system presents problems when international shipments enter the US Department of Transportation's system. Faced with the question of continuing a dual system or aligning with the international system, the Research and Special Programs Administration of the US Department of Transportation responded with Docket HM-181. This began the transition toward the international transportation system. Following close behind is Docket HM-169A, which addressed low specific activity radioactive material packaging. This paper will discuss the differences between performance-oriented and specification packaging, the transition toward performance-oriented packaging by the US Department of Transportation, and performance-oriented testing of radioactive material packaging by Westinghouse Hanford Company. Dockets HM-181 and HM-169A will be discussed along with Type A (low activity) and Type B (high activity) radioactive material packaging evaluations.

  10. Radioactive material packaging performance testing

    SciTech Connect

    Romano, T.

    1992-06-01

    In an effort to provide uniform packaging of hazardous material on an international level, recommendations for the transport of dangerous goods have been developed by the United Nations. These recommendations are performance oriented and contrast with a large number of packaging specifications in the US Department of Transportation`s hazard materials regulations. This dual system presents problems when international shipments enter the US Department of Transportation`s system. Faced with the question of continuing a dual system or aligning with the international system, the Research and Special Programs Administration of the US Department of Transportation responded with Docket HM-181. This began the transition toward the international transportation system. Following close behind is Docket HM-169A, which addressed low specific activity radioactive material packaging. This paper will discuss the differences between performance-oriented and specification packaging, the transition toward performance-oriented packaging by the US Department of Transportation, and performance-oriented testing of radioactive material packaging by Westinghouse Hanford Company. Dockets HM-181 and HM-169A will be discussed along with Type A (low activity) and Type B (high activity) radioactive material packaging evaluations.

  11. Properties of five toughened matrix composite materials

    NASA Technical Reports Server (NTRS)

    Cano, Roberto J.; Dow, Marvin B.

    1992-01-01

    The use of toughened matrix composite materials offers an attractive solution to the problem of poor damage tolerance associated with advanced composite materials. In this study, the unidirectional laminate strengths and moduli, notched (open-hole) and unnotched tension and compression properties of quasi-isotropic laminates, and compression-after-impact strengths of five carbon fiber/toughened matrix composites, IM7/E7T1-2, IM7/X1845, G40-800X/5255-3, IM7/5255-3, and IM7/5260 have been evaluated. The compression-after-impact (CAI) strengths were determined primarily by impacting quasi-isotropic laminates with the NASA Langley air gun. A few CAI tests were also made with a drop-weight impactor. For a given impact energy, compression after impact strengths were determined to be dependent on impactor velocity. Properties and strengths for the five materials tested are compared with NASA data on other toughened matrix materials (IM7/8551-7, IM6/1808I, IM7/F655, and T800/F3900). This investigation found that all five materials were stronger and more impact damage tolerant than more brittle carbon/epoxy composite materials currently used in aircraft structures.

  12. Thermal Property Parameter Estimation of TPS Materials

    NASA Technical Reports Server (NTRS)

    Maddren, Jesse

    1998-01-01

    Accurate knowledge of the thermophysical properties of TPS (thermal protection system) materials is necessary for pre-flight design and post-flight data analysis. Thermal properties, such as thermal conductivity and the volumetric specific heat, can be estimated from transient temperature measurements using non-linear parameter estimation methods. Property values are derived by minimizing a functional of the differences between measured and calculated temperatures. High temperature thermal response testing of TPS materials is usually done in arc-jet or radiant heating facilities which provide a quasi one-dimensional heating environment. Last year, under the NASA-ASEE-Stanford Fellowship Program, my work focused on developing a radiant heating apparatus. This year, I have worked on increasing the fidelity of the experimental measurements, optimizing the experimental procedures and interpreting the data.

  13. The impact of bone and suture material properties on mandibular function in Alligator mississippiensis: testing theoretical phenotypes with finite element analysis.

    PubMed

    Reed, David A; Porro, Laura B; Iriarte-Diaz, Jose; Lemberg, Justin B; Holliday, Casey M; Anapol, Fred; Ross, Callum F

    2011-01-01

    The functional effects of bone and suture stiffness were considered here using finite element models representing three different theoretical phenotypes of an Alligator mississippiensis mandible. The models were loaded using force estimates derived from muscle architecture in dissected specimens, constrained at the 18th and 19th teeth in the upper jaw and 19th tooth of the lower jaw, as well as at the quadrate-articular joint. Stiffness was varied systematically in each theoretical phenotype. The three theoretical phenotypes included: (i) linear elastic isotropic bone of varying stiffness and no sutures; (ii) linear elastic orthotropic bone of varying stiffness with no sutures; and (iii) linear elastic isotropic bone of a constant stiffness with varying suture stiffness. Variation in the isotropic material properties of bone primarily resulted in changes in the magnitude of principal strain. By comparison, variation in the orthotropic material properties of bone and isotropic material properties of sutures resulted in: a greater number of bricks becoming either more compressive or more tensile, changing between being either dominantly compressive or tensile, and having larger changes in the orientation of maximum principal strain. These data indicate that variation in these model properties resulted in changes to the strain regime of the model, highlighting the importance of using biologically verified material properties when modeling vertebrate bones. When bones were compared within each set, the response of each to changing material properties varied. In two of the 12 bones in the mandible, varied material properties within sutures resulted in a decrease in the magnitude of principal strain in bricks adjacent to the bone/suture interface and decreases in stored elastic energy. The varied response of the mandibular bones to changes in suture stiffness highlights the importance of defining the appropriate functional unit when addressing relationships of

  14. The impact of bone and suture material properties on mandibular function in Alligator mississippiensis: testing theoretical phenotypes with finite element analysis

    PubMed Central

    Reed, David A; Porro, Laura B; Iriarte-Diaz, Jose; Lemberg, Justin B; Holliday, Casey M; Anapol, Fred; Ross, Callum F

    2011-01-01

    Abstract The functional effects of bone and suture stiffness were considered here using finite element models representing three different theoretical phenotypes of an Alligator mississippiensis mandible. The models were loaded using force estimates derived from muscle architecture in dissected specimens, constrained at the 18th and 19th teeth in the upper jaw and 19th tooth of the lower jaw, as well as at the quadrate-articular joint. Stiffness was varied systematically in each theoretical phenotype. The three theoretical phenotypes included: (i) linear elastic isotropic bone of varying stiffness and no sutures; (ii) linear elastic orthotropic bone of varying stiffness with no sutures; and (iii) linear elastic isotropic bone of a constant stiffness with varying suture stiffness. Variation in the isotropic material properties of bone primarily resulted in changes in the magnitude of principal strain. By comparison, variation in the orthotropic material properties of bone and isotropic material properties of sutures resulted in: a greater number of bricks becoming either more compressive or more tensile, changing between being either dominantly compressive or tensile, and having larger changes in the orientation of maximum principal strain. These data indicate that variation in these model properties resulted in changes to the strain regime of the model, highlighting the importance of using biologically verified material properties when modeling vertebrate bones. When bones were compared within each set, the response of each to changing material properties varied. In two of the 12 bones in the mandible, varied material properties within sutures resulted in a decrease in the magnitude of principal strain in bricks adjacent to the bone/suture interface and decreases in stored elastic energy. The varied response of the mandibular bones to changes in suture stiffness highlights the importance of defining the appropriate functional unit when addressing relationships of

  15. Thermal expansion properties of composite materials

    NASA Technical Reports Server (NTRS)

    Johnson, R. R.; Kural, M. H.; Mackey, G. B.

    1981-01-01

    Thermal expansion data for several composite materials, including generic epoxy resins, various graphite, boron, and glass fibers, and unidirectional and woven fabric composites in an epoxy matrix, were compiled. A discussion of the design, material, environmental, and fabrication properties affecting thermal expansion behavior is presented. Test methods and their accuracy are discussed. Analytical approaches to predict laminate coefficients of thermal expansion (CTE) based on lamination theory and micromechanics are also included. A discussion is included of methods of tuning a laminate to obtain a near-zero CTE for space applications.

  16. Mechanical properties of thermal protection system materials.

    SciTech Connect

    Hardy, Robert Douglas; Bronowski, David R.; Lee, Moo Yul; Hofer, John H.

    2005-06-01

    An experimental study was conducted to measure the mechanical properties of the Thermal Protection System (TPS) materials used for the Space Shuttle. Three types of TPS materials (LI-900, LI-2200, and FRCI-12) were tested in 'in-plane' and 'out-of-plane' orientations. Four types of quasi-static mechanical tests (uniaxial tension, uniaxial compression, uniaxial strain, and shear) were performed under low (10{sup -4} to 10{sup -3}/s) and intermediate (1 to 10/s) strain rate conditions. In addition, split Hopkinson pressure bar tests were conducted to obtain the strength of the materials under a relatively higher strain rate ({approx}10{sup 2} to 10{sup 3}/s) condition. In general, TPS materials have higher strength and higher Young's modulus when tested in 'in-plane' than in 'through-the-thickness' orientation under compressive (unconfined and confined) and tensile stress conditions. In both stress conditions, the strength of the material increases as the strain rate increases. The rate of increase in LI-900 is relatively small compared to those for the other two TPS materials tested in this study. But, the Young's modulus appears to be insensitive to the different strain rates applied. The FRCI-12 material, designed to replace the heavier LI-2200, showed higher strengths under tensile and shear stress conditions. But, under a compressive stress condition, LI-2200 showed higher strength than FRCI-12. As far as the modulus is concerned, LI-2200 has higher Young's modulus both in compression and in tension. The shear modulus of FRCI-12 and LI-2200 fell in the same range.

  17. Mast material test program (MAMATEP)

    NASA Technical Reports Server (NTRS)

    Ciancone, Michael L.; Rutledge, Sharon K.

    1988-01-01

    The Mast Material Test Program (MAMATEP) at NASA Lewis is discussed. Objectives include verifying the need for, and evaluating the performance of, various protection techniques for the Solar Array Assembly mast of the Space Station Photovoltaic Power Module. Mast material samples were evaluated in terms of mass and bending modulus, measured before and after environmental exposure. Test environments included atomic oxygen exposure (RF plasma asher), thermal cycling, and mechanical flexing. Protective coatings included CV-1144 silicon, a Ni/Au/InSn eutectic, and an open weave, Al braid. Results indicate that unprotected samples degrade in an atomic oxygen environment at a steady rate. Open weave, Al braid offers little protection for the fiberglass-epoxy sample in an asher environment. Ni/Au/InSn eutectic offers excellent protection in an asher environment prior to thermal cycling and mechanical flexing. Long duration asher results from unprotected samples indicate that, even though the fiberglass-epoxy degrades, a protection technique may not be necessary to ensure structural integrity. However, a protection technique may be desirable to limit or contain the amount of debris generated by the degradation of the fiberglass-epoxy.

  18. Handbook of photothermal test data on encapsulant materials

    NASA Technical Reports Server (NTRS)

    Liang, R. H.; Oda, K. L.; Chung, S. Y.; Smith, M. V.; Gupta, A.

    1983-01-01

    Laboratory tests performed to characterize candidate encapsulation materials with respect to changes in their physical and chemical properties caused by photothermal aging are described. Several key material properties relating directly to material degradation and deterioration of performance were identified and were monitored as functions of aging conditions and time. A status report on accelerated testing activities is provided and experimental data are presented. It will be updated periodically as more data become available.

  19. MATERIAL PROPERTIES OF COMMON SUTURE MATERIALS IN ORTHOPAEDIC SURGERY

    PubMed Central

    Najibi, S; Banglmeier, R; Matta, JM; Tannast, M

    2010-01-01

    Suture materials in orthopaedic surgery are used for closure of wounds, repair of fascia, muscles, tendons, ligaments, joint capsules, and cerclage or tension band of certain fractures. The purpose of this study was to compare the biomechanical properties of eleven commonly used sutures in orthopaedic surgery. Three types of braided non-absorbable and one type of braided absorbable suture material with different calibers (n=77) underwent biomechanical testing for maximum load to failure, strain, and stiffness. All samples were tied by one surgeon with a single SMC (Seoul Medical Center) knot and three square knots. The maximum load to failure and strain were highest for #5 FiberWire and lowest for #0 Ethibond Excel (p<0.001). The stiffness was highest for #5 FiberWire and lowest for #2-0 Vicryl (p<0.001). In all samples, the failure of the suture material occurred at the knot There was no slippage of the knot in any of the samples tested. This data will assist the orthopaedic surgeon in selection and application of appropriate suture materials and calibers to specific tasks. PMID:21045977

  20. Unmanned Vehicle Material Flammability Test

    NASA Technical Reports Server (NTRS)

    Urban, David; Ruff, Gary A.; Fernandez-Pello, A. Carlos; T’ien, James S.; Torero, Jose L.; Cowlard, Adam; Rouvreau, Sebastian; Minster, Olivier; Toth, Balazs; Legros, Guillaume; Eigenbrod, Christian; Smirnov, Nickolay; Fujita, Osamu; Jomaas, Grande

    2013-01-01

    Microgravity combustion phenomena have been an active area of research for the past 3 decades however, there have been very few experiments directly studying spacecraft fire safety under low-gravity conditions. Furthermore, none of these experiments have studied sample and environment sizes typical of those expected in a spacecraft fire. All previous experiments have been limited to samples of the order of 10 cm in length and width or smaller. Terrestrial fire safety standards for all other habitable volumes on earth, e.g. mines, buildings, airplanes, ships, etc., are based upon testing conducted with full-scale fires. Given the large differences between fire behavior in normal and reduced gravity, this lack of an experimental data base at relevant length scales forces spacecraft designers to base their designs using 1-g understanding. To address this question a large scale spacecraft fire experiment has been proposed by an international team of investigators. This poster presents the objectives, status and concept of this collaborative international project to examine spacecraft material flammability at realistic scales. The concept behind this project is to utilize an unmanned spacecraft such as Orbital Cygnus vehicle after it has completed its delivery of cargo to the ISS and it has begun its return journey to earth. This experiment will consist of a flame spread test involving a meter scale sample ignited in the pressurized volume of the spacecraft and allowed to burn to completion while measurements are made. A computer modeling effort will complement the experimental effort. Although the experiment will need to meet rigorous safety requirements to ensure the carrier vehicle does not sustain damage, the absence of a crew removes the need for strict containment of combustion products. This will facilitate the examination of fire behavior on a scale that is relevant to spacecraft fire safety and will provide unique data for fire model validation. This will be

  1. Thermal Systems and Materials Testing

    NASA Technical Reports Server (NTRS)

    Aguirre, Nathan

    2010-01-01

    During my internship, I was involved in Boeing Thermal System/M&P, which handles maintenance and repairs of shuttle tiles, blankets, gap fillers, etc. One project I took part in was the revision of TPS-227, a repair process to tiles that entailed drilling out tile damage and using a cylindrical insert to fill the hole. The previous specification used minimal adhesive for application and when the adhesive cured, there would be several voids in the adhered material, causing an unsatisfactory bond. The testing compared several new methods and I analyzed the number of voids produced by each method to determine which one was most effective at eliminating void space. We revised the original process to apply a light adhesive coat to the top 25% of the borehole and a heavy coat to 100% of the insert. I was also responsible for maintaining the subnominal bond database, which records all unsatisfactory SIP (Strain Isolator Pad) bonds. I then archived each SIP physically for future referral data and statistics. In addition, I performed post-flight tile inspections for damages and wrote dispositions to have these tiles repaired. This also included writing a post-flight damage report for a section of Atlantis and creating summarized repair process guidelines for orbiter technicians.

  2. Ceramic materials testing and modeling

    SciTech Connect

    Wilfinger, K. R., LLNL

    1998-04-30

    Certain refractory ceramics (notably oxides) have desirable properties suitable for the construction of ceramic waste containers for long term use in nuclear waste disposal applications. In particular, they are far less prone to environmental corrosion than metals under realistic repository conditions. The aqueous corrosion rates of oxides such as magnesium aluminate spinel (MgAl{sub 2}0{sub 4}) and alumina (Al{sub 2}0{sub 4}) fall in the range of a few millimeters per million years. Oxide ceramics are also not likely to be subject to microbiologically influenced corrosion, which apparently can attack most, if not all, of the available engineering metals. Ceramics have a reputation for poor mechanical performance and large, impermeable objects are not easily fabricated by most current fabrication methods. As a result, the most promising approach for incorporating ceramics in large waste packages appears to be to apply a high density ceramic coating to a supporting metallic structure. Ceramic coatings 2048 applied by a thermal spray technique can be made effectively seamless and provide a method for final closure of the waste package while maintaining low average temperatures for the entire assembly. The corrosion resistance of the ceramic should prevent or delay water penetration to the underlying metal, which will in turn provide most of the mechanical strength and toughness required by the application. In this way, the major concerns regarding the ceramic coating become ensuring it is impervious to moisture, its adherence and its resistance to mechanical stresses during handling or resulting from rock fall in the repository. Without water, electrochemical corrosion and microbiologically influenced corrosion processes are considered impossible, so a complete coating should protect the metal vessels for far longer than the current design requirements. Even an imperfect coating should extend the life of the package, delaying the onset and reducing the severity of

  3. Integration of test methodology, material database, and material selection/deselection strategies for a chemical-material compatibility database system

    SciTech Connect

    Shuely, W.J.

    1995-12-31

    The effect of chemical exposure on the degradation of material properties is important to material evaluation and selection for both commercial and military products. Described here are a set of enhancements to a traditional chemical-material compatibility database that were required to support the early selection of chemically resistant materials in a concurrent engineering environment. This initial phase in the development of an integrated chemical-material compatibility system included: organization of tests into a comprehensive scheme, test selection for the initial screening tests in the scheme, the increased standardization of test procedures and reports required to support database queries, and the control of data set flow from the test laboratory directly to the database. Emphasized here is the design of modular database files based on material, chemical, and test specification descriptors that are indexed to the resulting test properties database module. ASTM Committee E49 formats were employed where available. The polymeric material documentation has been implemented by development of a menu-driven laboratory database version of ASTM Guide for the Identification of Polymers (Excludes Thermoset Elastomers) in Computerized Material Property Databases (E 1308-92). Examples are provided from the screening test found in the initial section of the test method scheme. One is able to execute a rapid paperless transfer of predictive and experimental screening results to the chemical-material compatibility database, query the results to eliminate a substantial fraction of materials and rank a more limited set of candidate materials to provide a useful ``deselection`` capability.

  4. MEASUREMENT OF MATERIAL PROPERTIES OF DAMAGED ENERGETIC MATERIALS

    SciTech Connect

    Hsu, P C; Hust, G; Dehaven, M; Chidester, S; Glascoe, L; Hoffman, M; Maienschein, J L

    2010-03-10

    We recently conducted damaged experiments on three explosives (mechanical damage on LX-04 and thermal experiments on HPP and PBXN-9) and characterized the effect of damage on some material properties. The MTS equipment was used to apply compressive cycling to LX-04 pressed parts and the results showed that older LX-04 parts became mechanically weaker than newer parts. After repeated compressive cycling for over 20,000 times, older LX-04 parts failed but newer LX-04 parts survived. Thermal insults were applied to PBXN-9 and HPP at 180 C and 200 C, respectively in unconfined conditions for several hours. The thermally-damaged HPP sample suffered 12.0% weight losses and a volume expansion of 20% was observed. Porosity of the damaged HPP increased to 25% after thermal exposure, which led to higher gas permeability. Burn rates of damaged PBXN-9 were 2 orders of magnitude higher than those of pristine samples but burn rates of damaged HPP were only slightly higher than those of pristine HPP. Small-scale safety tests (impact, friction, and spark) showed no significant sensitization when the damaged samples were tested at room temperature. Gas permeation measurements showed that gas permeability in damaged materials was several orders of magnitude higher than that in pristine materials. In-situ measurements of gas permeability at high temperatures were made on HPP samples and the results showed that the gas permeability increased by 3 to 4 orders of magnitude.

  5. Machining as a mechanical property test revisited

    NASA Astrophysics Data System (ADS)

    Smith, David L.

    There is much need for data on mechanical behavior of metals at high strains and strain rates. This need is dictated by modeling of processes like forming and machining, wherein the material in the deformation zone is subjected to severe deformation conditions atypical of conventional material property tests such as tension and torsion. Accurate flow stress data is an essential input for robust prediction of process outputs. Similar requirements arise from applications in high speed ballistic penetration and design of materials for armor. Since the deformation zone in cutting of metals is characterized by unique and extreme combinations of strain, strain rate and temperature, an opportunity exists for using plane-strain cutting as a mechanical property test for measuring flow properties of metals. The feasibility of using plane-strain cutting to measure flow properties of metals is revisited in the light of recent data showing controllability of the deformation conditions in chip formation by systematic variation of process input parameters. A method is outlined as to how the deformation conditions can be varied by changing the process parameters. The method is applied to cutting of commercially pure copper (FCC), iron (BCC) and zinc (HCP). Forces and chip geometries are measured, in conjunction with particle image velocimetry characterization of the deformation using high speed image sequences. The flow stresses are estimated from these measurements. The measured flow stress and its dependence on strain are shown to agree well with prior measurements of these parameters using conventional tests, and flow stress inferred from hardness characterization. The method is also demonstrated to be able to measure properties of metals that recrystallize at room temperature (zinc), wherein quasi-static tests predict much lower strength. Sources of variability and uncertainty in the application of this measurement technique are discussed. Future work in the context of further

  6. NIST Materials Properties Databases for Advanced Ceramics

    PubMed Central

    Munro, R. G.

    2001-01-01

    The NIST Ceramics Division maintains two databases on the physical, mechanical, thermal, and other properties of high temperature superconductors and structural ceramics. Crystallographic data are featured prominently among the physical property data and serve several important functions in the classification and evaluation of the property values. The scope of materials, properties, and data evaluation protocols are discussed for the two databases.

  7. Property Data Summaries for Advanced Materials

    National Institute of Standards and Technology Data Gateway

    SRD 150 NIST Property Data Summaries for Advanced Materials (Web, free access)   Property Data Summaries are topical collections of property values derived from surveys of published data. Thermal, mechanical, structural, and chemical properties are included in the collections.

  8. Physical Properties of Synthetic Resin Materials

    NASA Technical Reports Server (NTRS)

    Fishbein, Meyer

    1939-01-01

    A study was made to determine the physical properties of synthetic resins having paper, canvas, and linen reinforcements, and of laminated wood impregnated with a resin varnish. The results show that commercial resins have moduli of elasticity that are too low for structural considerations. Nevertheless, there do exist plastics that have favorable mechanical properties and, with further development, it should be possible to produce resin products that compare favorably with the light-metal alloys. The results obtained from tests on Compound 1840, resin-impregnated wood, show that this material can stand on its own merit by virtue of a compressive strength four times that of the natural wood. This increase in compressive strength was accomplished with an increase of density to a value slightly below three times the normal value and corrected one of the most serious defects of the natural product.

  9. Large scale Hugoniot material properties for Danby Marble

    SciTech Connect

    Rinehart, E.J.

    1993-11-01

    This paper presents the results of simulation experiments of nuclear underground testing carried out using the HYDROPLUS methodology for yield verifications of non-standard tests. The objective of this test series was to demonstrate the accuracy of stress and velocity measurements in hard, low porosity rock, to obtain comparisons of large-scale material properties with those obtained from laboratory testing of the same material, and to address the problems posed by a material having a clear precursor wave preceding the main shock wave. The test series consisted of three individual experimental tests. The first established material properties of the Danby marble selected for use in the experiments. The second and third tests looked at stress and velocity gage errors obtained when gages were placed in boreholes and grouted into place.

  10. Electrical Arc Ignition Testing of Spacesuit Materials

    NASA Technical Reports Server (NTRS)

    Smith, Sarah; Gallus, Tim; Tapia, Susana; Ball, Elizabeth; Beeson, Harold

    2006-01-01

    A viewgraph presentation on electrical arc ignition testing of spacesuit materials is shown. The topics include: 1) Background; 2) Test Objectives; 3) Test Sample Materials; 4) Test Methods; 5) Scratch Test Objectives; 6) Cotton Scratch Test Video; 7) Scratch Test Results; 8) Entire Date Plot; 9) Closeup Data Plot; 10) Scratch Test Problems; 11) Poke Test Objectives; 12) Poke Test Results; 13) Poke Test Problems; 14) Wire-break Test Objectives; 15) Cotton Wire-Break Test Video; 16) High Speed Cotton Wire-break Test Video; 17) Typical Data Plot; 18) Closeup Data Plot; 19) Wire-break Test Results; 20) Wire-break Tests vs. Scratch Tests; 21) Urethane-coated Nylon; and 22) Moleskin.

  11. TESTS OF FABRIC FILTRATION MATERIALS

    EPA Science Inventory

    The report describes laboratory and pilot scale testing of filter fabrics. Tests were made on flat specimens and on bags. Fifteen styles of fabrics (made from cotton, polyester, aramid, or glass) were tested, using cement, coal, or talc dusts. Collection efficiencies and pressure...

  12. Spacecraft dielectric material properties and spacecraft charging

    NASA Technical Reports Server (NTRS)

    Frederickson, A. R.; Wall, J. A.; Cotts, D. B.; Bouquet, F. L.

    1986-01-01

    The physics of spacecraft charging is reviewed, and criteria for selecting and testing semiinsulating polymers (SIPs) to avoid charging are discussed and illustrated. Chapters are devoted to the required properties of dielectric materials, the charging process, discharge-pulse phenomena, design for minimum pulse size, design to prevent pulses, conduction in polymers, evaluation of SIPs that might prevent spacecraft charging, and the general response of dielectrics to space radiation. SIPs characterized include polyimides, fluorocarbons, thermoplastic polyesters, poly(alkanes), vinyl polymers and acrylates, polymers containing phthalocyanine, polyacene quinones, coordination polymers containing metal ions, conjugated-backbone polymers, and 'metallic' conducting polymers. Tables summarizing the results of SIP radiation tests (such as those performed for the NASA Galileo Project) are included.

  13. 46 CFR 154.430 - Material test.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 5 2013-10-01 2013-10-01 false Material test. 154.430 Section 154.430 Shipping COAST... § 154.430 Material test. (a) The membrane and the membrane supporting insulation must be made of materials that withstand the combined strains calculated under § 154.429(c). (b) Analyzed data of a...

  14. 46 CFR 154.430 - Material test.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Material test. 154.430 Section 154.430 Shipping COAST... § 154.430 Material test. (a) The membrane and the membrane supporting insulation must be made of materials that withstand the combined strains calculated under § 154.429(c). (b) Analyzed data of a...

  15. Nondestructive ultrasonic testing of materials

    DOEpatents

    Hildebrand, B.P.

    1994-08-02

    Reflection wave forms obtained from aged and unaged material samples can be compared in order to indicate trends toward age-related flaws. Statistical comparison of a large number of data points from such wave forms can indicate changes in the microstructure of the material due to aging. The process is useful for predicting when flaws may occur in structural elements of high risk structures such as nuclear power plants, airplanes, and bridges. 4 figs.

  16. Nondestructive ultrasonic testing of materials

    DOEpatents

    Hildebrand, Bernard P.

    1994-01-01

    Reflection wave forms obtained from aged and unaged material samples can be compared in order to indicate trends toward age-related flaws. Statistical comparison of a large number of data points from such wave forms can indicate changes in the microstructure of the material due to aging. The process is useful for predicting when flaws may occur in structural elements of high risk structures such as nuclear power plants, airplanes, and bridges.

  17. SNLL materials testing compression facility

    SciTech Connect

    Kawahara, W.A.; Brandon, S.L.; Korellis, J.S.

    1986-04-01

    This report explains software enhancements and fixture modifications which expand the capabilities of a servo-hydraulic test system to include static computer-controlled ''constant true strain rate'' compression testing on cylindrical specimens. True strains in excess of -1.0 are accessible. Special software features include schemes to correct for system compliance and the ability to perform strain-rate changes; all software for test control and data acquisition/reduction is documented.

  18. Acoustic emission monitoring of tensile testing of corroded and un-corroded clad aluminum 2024-T3 and characterization of effects of corrosion on AE source events and material tensile properties

    NASA Astrophysics Data System (ADS)

    Okafor, A. Chukwujekwu; Natarajan, Shridhar

    2014-02-01

    Corrosion damage affects structural integrity and deteriorates material properties of aluminum alloys in aircraft structures. Acoustic Emission (AE) is an effective nondestructive evaluation (NDE) technique for monitoring such damages and predicting failure in large structures of an aircraft. For successful interpretation of data from AE monitoring, sources of AE and factors affecting it need to be identified. This paper presents results of AE monitoring of tensile testing of corroded and un-corroded clad Aluminum 2024-T3 test specimens, and characterization of the effects of strain-rate and corrosion damage on material tensile properties and AE source events. Effect of corrosion was studied by inducing corrosion in the test specimens by accelerated corrosion testing in a Q-Fog accelerated corrosion chamber for 12 weeks. Eight (8) masked dog-bone shaped specimens were placed in the accelerated corrosion chamber at the beginning of the test. Two (2) dog-bone shaped specimens were removed from the corrosion chamber after exposure time of 3, 6, 9, and 12 weeks respectively, and subjected to tension testing till specimen failure along with AE monitoring, as well as two (2) reference samples not exposed to corrosion. Material tensile properties (yield strength, ultimate tensile strength, toughness, and elongation) obtained from tension test and AE parameters obtained from AE monitoring were analyzed and characterized. AE parameters increase with increase in exposure period of the specimens in the corrosive environment. Aluminum 2024-T3 is an acoustically silent material during tensile deformation without any damage. Acoustic emission events increase with increase of corrosion damage and with increase in strain rate above a certain value. Thus AE is suitable for structural health monitoring of corrosion damage. Ultimate tensile strength, toughness and elongation values decrease with increase of exposure period in corrosion chamber.

  19. TEST OF FABRIC FILTRATION MATERIALS

    EPA Science Inventory

    The report describes pilot scale and laboratory tests of U.S. and Polish woven baghouse fabrics. Cotton, polyester, aramid, and glass fabrics were tested using cement, flyash, coal, and talc dusts at loadings of about 10 g/cu m, filtration velocities of 60 and 80 cu m/sq m, and a...

  20. 46 CFR 154.430 - Material test.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 5 2012-10-01 2012-10-01 false Material test. 154.430 Section 154.430 Shipping COAST... § 154.430 Material test. (a) The membrane and the membrane supporting insulation must be made of... test for the membrane and the membrane supporting insulation must be submitted to the Commandant...

  1. Investigation of test methods, material properties, and processes for solar cell encapsulants. Eighteenth quarterly progress report, August 12-November 12, 1980

    SciTech Connect

    Willis, P. B.; Baum, B.; Davis, M.

    1980-12-01

    The goal of this program is to identify, evaluate, and recommend encapsulant materials and processes for the production of cost-effective, long-life solar cell modules. A survey was made of elastomers for use as gaskets for the photovoltaic module. Of the wide variety of materials examined EPDM offered the optimum combination of low compression set and low cost. The preference for EPDM is borne out by its long history of use as an automobile gasket. The commercial availability of materials that would be useful for sealants between the edge of the module and the gasket was investigated. Butyl sealants have the best combination of physical properties, low cost and a well-documented history of performance. A preferred composition has not yet been identified. One laminating type pottant ethylene/methyl acrylate copolymer (EMA), and two casting polymers, polybutyl acrylate and polyurethane, have been under investigation this past quarter. An EMA formulation has been developed which is easily extrudable and cures to a high gel content. So far only one commercial US source (Quinn) of aliphatic polyurethane has been located. Work is continuing to improve reaction rate as well as to eliminate source(s) of bubble formation during module fabrication. Considerable effort was spent in developing an improved polybutyl acrylate casting formulation providing high gel. Many viable curing systems are now available: however, the best formulation considering physical properties, freedom from bubbles as well as cure time utilizes Lupersol II (aliphatic peroxide) initiator. This initiator gives the desired gel after 20 minute cure at 45/sup 0/C or 12 minute cure at 55/sup 0/C.

  2. Database for the Tribological Properties of Self-Lubricating Materials

    NASA Technical Reports Server (NTRS)

    Jett, T. R.; Thom, R. L.

    1998-01-01

    A test program to determine the tribological properties of several self-lubricating composites was performed. Testing was done using an LFW-1 Friction and Wear machine. Each material was tested at four load levels (66 N, 133 N, 266 N, and 400 N) under ambient conditions. The coefficient of friction and wear rate was determined for each material, and a relative ranking of the composites was made.

  3. Solid oxide materials research accelerated electrochemical testing

    SciTech Connect

    Windisch, C.; Arey, B.

    1995-08-01

    The objectives of this work were to develop methods for accelerated testing of cathode materials for solid oxide fuel cells under selected operating conditions. The methods would be used to evaluate the performance of LSM cathode material.

  4. Thermal testing of solid neutron shielding materials

    SciTech Connect

    Boonstra, R.H. )

    1990-03-01

    The GA-4 and GA-9 spent fuel shipping casks employ a solid neutron shielding material. During a hypothetical thermal accident, any combustion of the neutron shield must not compromise the ability of the cask to contain the radioactive contents. A two-phase thermal testing program was carried out to assist in selecting satisfactory shielding materials. In the first phase, small-scale screening tests were performed on nine candidate materials using ASTM procedures. From these initial results, three of the nine candidates were chosen for inclusion in the second phase of testing, These materials were Bisco Products NS-4-FR, Reactor Experiments 201-1, and Reactor Experiments 207. In the second phase, each selected material was fabricated into a test article which simulated a full-scale of neutron shield from the cask. The test article was heated in an environmental prescribed by NRC regulations. Results of this second testing phase showed that all three materials are thermally acceptable.

  5. Acoustical properties of double porosity granular materials.

    PubMed

    Venegas, Rodolfo; Umnova, Olga

    2011-11-01

    Granular materials have been conventionally used for acoustic treatment due to their sound absorptive and sound insulating properties. An emerging field is the study of the acoustical properties of multiscale porous materials. An example of these is a granular material in which the particles are porous. In this paper, analytical and hybrid analytical-numerical models describing the acoustical properties of these materials are introduced. Image processing techniques have been employed to estimate characteristic dimensions of the materials. The model predictions are compared with measurements on expanded perlite and activated carbon showing satisfactory agreement. It is concluded that a double porosity granular material exhibits greater low-frequency sound absorption at reduced weight compared to a solid-grain granular material with similar mesoscopic characteristics. PMID:22087905

  6. Materials Compatibility Testing in Concentrated Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Boxwell, R.; Bromley, G.; Mason, D.; Crockett, D.; Martinez, L.; McNeal, C.; Lyles, G. (Technical Monitor)

    2000-01-01

    Materials test methods from the 1960's have been used as a starting point in evaluating materials for today's space launch vehicles. These established test methods have been modified to incorporate today's analytical laboratory equipment. The Orbital test objective was to test a wide range of materials to incorporate the revolution in polymer and composite materials that has occurred since the 1960's. Testing is accomplished in 3 stages from rough screening to detailed analytical tests. Several interesting test observations have been made during this testing and are included in the paper. A summary of the set-up, test and evaluation of long-term storage sub-scale tanks is also included. This sub-scale tank test lasted for a 7-month duration prior to being stopped due to a polar boss material breakdown. Chemical evaluations of the hydrogen peroxide and residue left on the polar boss surface identify the material breakdown quite clearly. The paper concludes with recommendations for future testing and a specific effort underway within the industry to standardize the test methods used in evaluating materials.

  7. Unmanned Vehicle Material Flammability Test

    NASA Technical Reports Server (NTRS)

    Urban, David L.; Ruff, Gary A.; Minster, Olivier; Toth, Balazs; Fernandez-Pello, A. Carlos; Tien, James S.; Torero, Jose L.; Cowlard, Adam J.; Legros, Guillaume; Eigenbrod, Christian; Smirnov, Nickolay; Fujita, Osamu; Rouvreau, Sebastien; Jomaas, Grunde

    2012-01-01

    Microgravity fire behaviour remains poorly understood and a significant risk for spaceflight An experiment is under development that will provide the first real opportunity to examine this issue focussing on two objectives: a) Flame Spread. b) Material Flammability. This experiment has been shown to be feasible on both ESA's ATV and Orbital Science's Cygnus vehicles with the Cygnus as the current base-line carrier. An international topical team has been formed to develop concepts for that experiment and support its implementation: a) Pressure Rise prediction. b) Sample Material Selection. This experiment would be a landmark for spacecraft fire safety with the data and subsequent analysis providing much needed verification of spacecraft fire safety protocols for the crews of future exploration vehicles and habitats.

  8. Exploring the influence of loading geometry on the plastic flow properties of geological materials: Results from combined torsion + axial compression tests on calcite rocks

    NASA Astrophysics Data System (ADS)

    Covey-Crump, S. J.; Xiao, W. F.; Mecklenburgh, J.; Rutter, E. H.; May, S. E.

    2016-07-01

    For technical reasons, virtually all plastic deformation experiments on geological materials have been performed in either pure shear or simple shear. These special case loading geometries are rather restrictive for those seeking insight into how microstructure evolves under the more general loading geometries that occur during natural deformation. Moreover, they are insufficient to establish how plastic flow properties might vary with the 3rd invariant of the deviatoric stress tensor (J3) which describes the stress configuration, and so applications that use those flow properties (e.g. glaciological and geodynamical modelling) may be correspondingly compromised. We describe an inexpensive and relatively straightforward modification to the widely used Paterson rock deformation apparatus that allows torsion experiments to be performed under simultaneously applied axial loads. We illustrate the performance of this modification with the results of combined stress experiments performed on Carrara marble and Solnhofen limestone at 500°-600 °C and confining pressures of 300 MPa. The flow stresses are best described by the Drucker yield function which includes J3-dependence. However, that J3-dependence is small. Hence for these initially approximately isotropic calcite rocks, flow stresses are adequately described by the J3-independent von Mises yield criterion that is widely used in deformation modelling. Loading geometry does, however, have a profound influence on the type and rate of development of crystallographic preferred orientation, and hence of mechanical anisotropy. The apparatus modification extends the range of loading geometries that can be used to investigate microstructural evolution, as well as providing greater scope for determining the shape of the yield surface in plastically anisotropic materials.

  9. Synthesis and properties of nanophase materials

    SciTech Connect

    Siegel, R.W.

    1993-03-01

    Nanophase materials, with their grain sizes or phase dimensions in the nanometer size regime, are now being produced by a wide variety of synthesis and processing methods. The interest in these new ultrafine-grained materials results primarily from the special nature of their various physical, chemical, and mechanical properties and the possibilities to control these properties during the synthesis and subsequent processing procedures. Since it is now becoming increasingly apparent that their properties can be engineered effectively during synthesis and processing, and that they can also be produced in quantity, nanophase materials should have considerable potential for technological development in a variety of applications. Some of the recent research on nanophase materials related to their synthesis and properties is briefly reviewed and the future potential of these new materials is considered.

  10. Investigations of test methods, material properties, and processes, for solar-cell encapsulants. Twenty-second quarterly progress report for period ending November 12, 1982

    SciTech Connect

    Not Available

    1982-01-01

    Investigations were continued into pottants, soil resistant coatings and low cost substrate materials. Two component aliphatic urethane casting syrups for use as solar module pottants were evaluated for suitability on the basis of optical, physical and fabrication characteristics. One formulation was selected as being acceptable for industrial evaluation. This urethane is characterized by high transparency, low mix viscosity, fast cure time and surprising lack of moisture sensitivity that has given trouble with previous urethane compositions. This material is produced with an ultraviolet stabilizer system already blended in. An experimental program was continued to determine the effectiveness of soil resistant coatings. These treatments have been applied to Sunadex glass, Tedlar and oriented acrylic film. The treatments are based on silicone, acrylic and fluorosilane chemistries. Test specimens are being exposed to outdoor soiling conditions with subsequent testing for short circuit-current loss using a standard cell device. After nine months of outdoor exposure, the most effective treatment appears to be a silane modified adduct of perfluorodecanoic acid. The degree of soiling also appears to correlate to the amount of rainfall that results in a natural cleaning of the surface. Wood products, such as hardboard, are potentially the lowest cost candidate substrates identified to date. The difficulty with the use of these materials lies in the very high hygroscopic expansion coefficients. Periods of dryout followed by subsequent moisture regain results in large expansions and contractions that result in cell fracture. Experiments were conducted to determine the effectiveness of occlusive coatings to prevent this effect. Both metal foils and organic films bonded to the hardboard with appropriate adhesives were found to dramatically decrease the hygroscopic response and lower the expansion coefficient by four orders of magnitude.

  11. Investigation of test methods, material properties, and processes for solar-cell encapsulants. Twenty-third quarterly progress report for period ending February 12, 1982

    SciTech Connect

    Willis, P.B.; Baum, B.

    1982-04-01

    During the past quarter technical investigations concerned the development of advanced cure chemistries for lamination type pottants, the continued evaluation of soil resistant surface treatments, and the results of an accelerated aging test program for the comparison of material stabilities. New compounds were evaluated for efficiency in curing both ethylene/vinyl acetate and ethylene/methyl acrylate pottants. One compound in particular, designated Lupersol - TBEC was found to be unusually effective in promoting the rapid cure of both these materials. Formulation of these resins with TBEC resulted in compositions of very high gel content, lower temperatures of activation, and much lower cure times, even in the ethylene/methyl acrylate polymer that is more difficult to cure. An experimental program continued to determine the effectiveness of soil resistant coatings. These treatments have been applied to Sunadex glass, Tedlar and oriented acrylic film. The treatments are based on silicone, acrylic, and fluorosilane chemistries. After one year of outdoor exposure, the most effective treatment of Sunadex glass appears to be a fluorosilane designated L-1668, and for both the organic films a silane modified adduct of perfluoric acid gave the best results. After one year of time there is evidence that the treatments are slowly being lost and consequently a maintenance schedule may be required to maintain effectiveness over long periods of time. An accelerated aging test program is underway for the dual purpose of generating practical and empirical data relating to the service life of candidate encapsulation materials, and to provide data that may be useful in a predictive type of analysis.

  12. Material properties of novel polymeric films

    NASA Astrophysics Data System (ADS)

    Kim, Gene

    This dissertation will study the material properties of two types of novel polymer films (polyelectrolyte multilayer films and photolithographic polymer films). The formation of polylelectrolyte multilayer films onto functionalized aluminum oxide surfaces and functionalized poly(ethylene terephthaltate) (PET) were studied. Functionalization of the aluminum oxide surfaces was achieved via silane coupling. Functionalization of PET surfaces was achieved via hydrolysis and amidation. Surface characterization techniques such as X-ray photoelectron spectroscopy (XPS) and dynamic contact angle measurements were used to monitor the polyelectrolyte multilayer formation. Mechanical properties of the aluminum oxide supported polyelectrolyte multilayer films were tested using a simplified peel test. XPS was used to analyze the surfaces before and after peel. Single lap shear joint specimens were constructed to test the adhesive shear strength of the PET-supported polyelectrolyte multilayer film samples with the aid of a cyanoacrylate adhesive. The adhesive shear strength and its relation with the type of functionalization, number of polyelectrolyte layers, and the effect of polyelectrolyte conformation using added salt were explored. Also, characterization on the single lap joints after adhesive failure was carried out to determine the locus of failure within the multilayers by using XPS and SEM. Two types of photolithographic polymers were formulated and tested. These two polymers (photocrosslinkable polyacrylate (PUA), and a photocrosslinkable polyimide (HRP)) were used to investigate factors that would affect the structural integrity of these particular polymers under environmental variables such as processing (time, UV cure, pressure, and temperature) and ink exposure. Thermomechanical characterization was carried out to see the behavior of these two polymers under these environmental variables. Microscopic techniques were employed to study the morphological behavior of

  13. Elevated Temperature Testing and Modeling of Advanced Toughened Ceramic Materials

    NASA Technical Reports Server (NTRS)

    Keith, Theo G.

    2005-01-01

    The purpose of this report is to provide a final report for the period of 12/1/03 through 11/30/04 for NASA Cooperative Agreement NCC3-776, entitled "Elevated Temperature Testing and Modeling of Advanced Toughened Ceramic Materials." During this final period, major efforts were focused on both the determination of mechanical properties of advanced ceramic materials and the development of mechanical test methodologies under several different programs of the NASA-Glenn. The important research activities made during this period are: 1. Mechanical properties evaluation of two gas-turbine grade silicon nitrides. 2) Mechanical testing for fuel-cell seal materials. 3) Mechanical properties evaluation of thermal barrier coatings and CFCCs and 4) Foreign object damage (FOD) testing.

  14. Material Properties for Fiber-Reinforced Silica Aerogels

    NASA Technical Reports Server (NTRS)

    White, Susan; Rouanet, Stephane; Moses, John; Arnold, James O. (Technical Monitor)

    1994-01-01

    Ceramic fiber-reinforced silica aerogels are novel materials for high performance insulation, including thermal protection materials. Experimental data are presented for the thermal and mechanical properties, showing the trends exhibited over a range of fiber loadings and silica aerogel densities. Test results are compared to that of unreinforced bulk aerogels.

  15. Dynamic properties of ceramic materials

    SciTech Connect

    Grady, D.E.

    1995-02-01

    The present study offers new data and analysis on the transient shock strength and equation-of-state properties of ceramics. Various dynamic data on nine high strength ceramics are provided with wave profile measurements, through velocity interferometry techniques, the principal observable. Compressive failure in the shock wave front, with emphasis on brittle versus ductile mechanisms of deformation, is examined in some detail. Extensive spall strength data are provided and related to the theoretical spall strength, and to energy-based theories of the spall process. Failure waves, as a mechanism of deformation in the transient shock process, are examined. Strength and equation-of-state analysis of shock data on silicon carbide, boron carbide, tungsten carbide, silicon dioxide and aluminum nitride is presented with particular emphasis on phase transition properties for the latter two. Wave profile measurements on selected ceramics are investigated for evidence of rate sensitive elastic precursor decay in the shock front failure process.

  16. Learning targeted materials properties from data

    NASA Astrophysics Data System (ADS)

    Lookman, Turab; Balachandran, Prasanna V.; Dezhen, Xue; Theiler, James; Hogden, John

    We compare several strategies using a data set of 223 M2AX family of compounds for which the elastic properties [bulk (B), shear (G), and Young's (E) modulus] have been computed using density functional theory. The strategy is decomposed into two steps: a regressor is trained to predict elastic properties in terms of elementary orbital radii of the individual components of the materials; and a selector uses these predictions to choose the next material to investigate. The ultimate goal is to obtain a material with desired elastic properties. We examine how the choice of data set size, regressor and selector impact the results.

  17. Thermal Properties of Structural Materials Used in LWR Vessels

    SciTech Connect

    J. E. Daw; J. L. Rempe; D. L. Knudson

    2011-01-01

    High temperature material property data for structural materials used in existing Light Water Reactors (LWRs) are limited. Often, extrapolated values recommended in the literature differ significantly. To reduce uncertainties in predictions relying upon extrapolated data for LWR vessel and penetration materials, high temperature tests were completed on SA533 Grade B, Class 1 (SA533B1) low alloy steel, Stainless Steel 304 (SS304), and Inconel 600 using material property measurement systems available in the High Temperature Test Laboratory (HTTL) at the Idaho National Laboratory (INL). Properties measured include thermal expansion, specific heat capacity, and thermal diffusivity for temperatures up to 1200 °C. From these results, thermal conductivity and density were calculated. Results show that, in some cases, previously recommended values for these materials differ significantly from measured values at high temperatures.

  18. Investigation of test methods material properties, and processes for solar cell encapsulants. Fifteenth quarterly progress report, November 12, 1979-February 12, 1980

    SciTech Connect

    Willis, P. B.; Baum, B.

    1980-03-01

    The goal of this program is to identify, evaluate, and recommend encapsulant materials and processes for the production of cost-effective, long-life solar cell modules. Work performed during this quarter included the development of anti-blocking treatments for EVA sheet intended for use as a lamination pottant. Initial evaluation studies were begun on a new pottant compound, polybutyl acrylate, to assess its preparation and handling characteristics. Corrosion studies using a standard salt spray test wre conducted to determine the degree of protection afforded to a number of metals when encapsulated in candidate pottant compounds. Pottants and outer cover candidates were exposed to intervals of accelerated uv stress aging using the RS/4 fluorescent sunlamp. Results are discussed. (WHK)

  19. Quarantine testing and biocharacterization of lunar materials

    NASA Technical Reports Server (NTRS)

    Taylor, G. R.; Mieszkuc, B. J.; Simmonds, R. C.; Walkinshaw, C. H.

    1975-01-01

    Quarantine testing was conducted to ensure the safety of all life on earth. The plants and animals which were exposed to lunar material were carefully observed for prolonged periods to determine if any mutation or changes in growing characteristics and behavior occurred. The quarantine testing was terminated after the Apollo 14 flight when it became apparent that previously returned lunar material contained no potentially harmful agents. Further biological experimentation with the lunar material was conducted to determine its chemical, physical, and nutritional qualities.

  20. Thermal testing of solid neutron shielding materials

    SciTech Connect

    Boonstra, R.H.

    1992-09-01

    Two legal-weight truck casks the GA-4 and GA-9, will carry four PWR and nine BWR spent fuel assemblies, respectively. Each cask has a solid neutron shielding material separating the steel body and the outer steel skin. In the thermal accident specified by NRC regulations in 10CFR Part 71, the cask is subjected to an 800[degree]C environment for 30 minutes. The neutron shield need not perform any shielding function during or after the thermal accident, but its behavior must not compromise the ability of the cask to contain the radioactive contents. In May-June 1989 the first series of full-scale thermal tests was performed on three shielding materials: Bisco Products NS-4-FR, and Reactor Experiments RX-201 and RX-207. The tests are described in Thermal Testing of Solid Neutron Shielding Materials, GA-AL 9897, R. H. Boonstra, General Atomics (1990), and demonstrated the acceptability of these materials in a thermal accident. Subsequent design changes to the cask rendered these materials unattractive in terms of weight or adequate service temperature margin. For the second test series, a material specification was developed for a polypropylene based neutron shield with a softening point of at least 280[degree]F. The neutron shield materials tested were boronated (0.8--4.5%) polymers (polypropylene, HDPE, NS-4). The Envirotech and Bisco materials are not polypropylene, but were tested as potential backup materials in the event that a satisfactory polypropylene could not be found.

  1. Thermal testing of solid neutron shielding materials

    SciTech Connect

    Boonstra, R.H.

    1992-09-01

    Two legal-weight truck casks the GA-4 and GA-9, will carry four PWR and nine BWR spent fuel assemblies, respectively. Each cask has a solid neutron shielding material separating the steel body and the outer steel skin. In the thermal accident specified by NRC regulations in 10CFR Part 71, the cask is subjected to an 800{degree}C environment for 30 minutes. The neutron shield need not perform any shielding function during or after the thermal accident, but its behavior must not compromise the ability of the cask to contain the radioactive contents. In May-June 1989 the first series of full-scale thermal tests was performed on three shielding materials: Bisco Products NS-4-FR, and Reactor Experiments RX-201 and RX-207. The tests are described in Thermal Testing of Solid Neutron Shielding Materials, GA-AL 9897, R. H. Boonstra, General Atomics (1990), and demonstrated the acceptability of these materials in a thermal accident. Subsequent design changes to the cask rendered these materials unattractive in terms of weight or adequate service temperature margin. For the second test series, a material specification was developed for a polypropylene based neutron shield with a softening point of at least 280{degree}F. The neutron shield materials tested were boronated (0.8--4.5%) polymers (polypropylene, HDPE, NS-4). The Envirotech and Bisco materials are not polypropylene, but were tested as potential backup materials in the event that a satisfactory polypropylene could not be found.

  2. Synthesis, properties, and applications of nanophase materials

    SciTech Connect

    Siegel, R.W. |

    1995-04-01

    Work on the synthesis, properties, and applications of nanophase materials has developed rapidly during the past decade. A wide variety of methods now exist for their production, including several plasma-based processes. The possibilities for engineering new materials with unique or improved properties for a number of applications is now evident from the extant research results. A brief review is presented here along with some examples of useful application areas and some thoughts for the future of this field.

  3. Recommended Best Practices for the Characterization of Storage Properties of Hydrogen Storage Materials

    SciTech Connect

    2010-03-01

    This is a reference guide to common methodologies and protocols for measuring critical performance properties of advanced hydrogen storage materials. It helps users to communicate clearly the relevant performance properties of new materials as they are discovered and tested.

  4. Spacecraft Charging Sensitivity to Material Properties

    NASA Technical Reports Server (NTRS)

    Minow, Joseph I.; Edwards, David L.

    2015-01-01

    Evaluating spacecraft charging behavior of a vehicle in the space environment requires knowledge of the material properties relevant to the charging process. Implementing surface and internal charging models requires a user to specify a number of material electrical properties including electrical resistivity parameters (dark and radiation induced), dielectric constant, secondary electron yields, photoemission yields, and breakdown strength in order to correctly evaluate the electric discharge threat posed by the increasing electric fields generated by the accumulating charge density. In addition, bulk material mass density and/or chemical composition must be known in order to analyze radiation shielding properties when evaluating internal charging. We will first describe the physics of spacecraft charging and show how uncertainties in material properties propagate through spacecraft charging algorithms to impact the results obtained from charging models. We then provide examples using spacecraft charging codes to demonstrate their sensitivity to material properties. The goal of this presentation is to emphasize the importance in having good information on relevant material properties in order to best characterize on orbit charging threats.

  5. Frictional Ignition Testing of Composite Materials

    NASA Technical Reports Server (NTRS)

    Peralta, Steve; Rosales, Keisa; Robinson, Michael J.; Stoltzfus, Joel

    2006-01-01

    The space flight community has been investigating lightweight composite materials for use in propellant tanks for both liquid and gaseous oxygen for space flight vehicles. The use of these materials presents some risks pertaining to ignition and burning hazards in the presence of oxygen. Through hazard analysis process, some ignition mechanisms have been identified as being potentially credible. One of the ignition mechanisms was reciprocal friction; however, test data do not exist that could be used to clear or fail these types of materials as "oxygen compatible" for the reciprocal friction ignition mechanism. Therefore, testing was performed at White Sands Test Facility (WSTF) to provide data to evaluate this ignition mechanism. This paper presents the test system, approach, data results, and findings of the reciprocal friction testing performed on composite sample materials being considered for propellant tanks.

  6. Nonlinear optical properties of composite materials

    NASA Technical Reports Server (NTRS)

    Haus, Joseph W.; Inguva, Ramarao

    1991-01-01

    The optical properties of a new class of composite nonlinear materials composed of coated grains, such as cadmium sulfide with a silver coating, are examined. These materials exhibit intrinsic optical bistability and resonantly enhanced conjugate reflectivity. The threshold for intrinsic optical bistability is low enough for practical applications in optical communications and optical computing. Some problems associated with the fabrication of these materials are addressed. Based on preliminary results, switching times are expected to be in the subpicosecond range.

  7. Salt materials testing for a spacecraft adiabatic demagnetization refrigerator

    NASA Technical Reports Server (NTRS)

    Savage, M. L.; Kittel, P.; Roellig, T.

    1990-01-01

    As part of a technology development effort to qualify adiabatic demagnetization refrigerators for use in a NASA spacecraft, such as the Space Infrared Telescope Facility, a study of low temperature characteristics, heat capacity and resistance to dehydration was conducted for different salt materials. This report includes results of testing with cerrous metaphosphate, several synthetic rubies, and chromic potassium alum (CPA). Preliminary results show that CPA may be suitable for long-term spacecraft use, provided that the salt is property encapsulated. Methods of salt pill construction and testing for all materials are discussed, as well as reliability tests. Also, the temperature regulation scheme and the test cryostat design are briefly discussed.

  8. Software For Uniaxial Mechanical Testing Of Materials

    NASA Technical Reports Server (NTRS)

    Mcgaw, M. A.; Pech, D. K.

    1995-01-01

    Materials Testing Software system designed to simplify and automate both routine and not-so-routine materials-testing tasks encountered in laboratory. Supports plan/test/analyze cycle through collection of programs, each optimized to specific task. Gives precise control over nature of command waveforms and acquisition of data, including dynamically variable waveform types, sets of data-acquisition channels, and data rates. Differing command and data-acquisition rates required for exploring creep and fatigue material behavior easily accommodated. Written in Modula-2.

  9. Repair material properties for effective structural application

    SciTech Connect

    Mangat, P.S.; Limbachiya, M.C.

    1997-04-01

    Strength and engineering properties of three generic repair materials which are likely to influence long-term performance of repaired concrete structures were studied. Measured properties include strength, stiffness, shrinkage and creep deformations, together with the complete compressive stress-strain characteristics including post-cracking behavior. The repair materials considered in this investigation are commercially available and widely used. These included a high performance non-shrinkable concrete, a mineral based cementitious material with no additives or coarse aggregate size particles, and a cementitious mortar containing styrene acrylic copolymer with fiber additives. Performance comparisons are also made between these materials and plain concrete mixes of similar strength and stiffness, suitable for repair applications. The results show that shrinkage of the repair materials was significantly greater than the shrinkage of normal concrete. Moreover, the shrinkage of those modified with a polymer admixture was found to be very sensitive to the relative humidity of the exposure compared to normal concrete. The post-peak strain capacity of the material modified with a polymer admixture was markedly improved leading to a more pronounced falling branch of stress-strain curve. The ultimate stress level (at a maximum load) of specially formulated repair materials varies significantly, the lowest ultimate stress being recorded for the porous mineral-based material. The inclusion of aggregates improves the mechanical properties and dimensional stability of repair materials.

  10. From Microstructures to Predict Properties of Materials

    NASA Astrophysics Data System (ADS)

    Wang, Ke-Gang

    2010-03-01

    Understanding the precise and fundamental manner in which materials structures (nanostructures or microstructures) and their evolution influences properties and service lifetimes of advanced materials profoundly impacts material design and today materials design plays an increasingly important rôle in many engineering applications. Linking structures to properties and predicting properties of materials is fundamental step for materials design. First, a framework of applications of multiscale modeling to property prediction of advanced materials will be briefly presented. As an example, a methodology will be shown to link micro-scale to the continuum scale, integrating microstructure modeling with the large Thermo-Calc^ database. This paradigm was successfully applied to the case of Fe-12Ni-6Mn maraging steel. Next, methodology for integrating first-principle calculation into simulations of microstructure evolution will be reviewed. Our methods are sufficiently reliable to permit control and fabrication of quantum-dots structures, nanocrystals, and particle-reinforced nanocomposites, as well as assist in the predictive behavior of macro-scale colloids, aerosols, and other soft matter systems.

  11. Room temperature mechanical properties of shuttle thermal protection system materials

    NASA Technical Reports Server (NTRS)

    Sawyer, J. W.; Rummler, D. R.

    1980-01-01

    Tests were conducted at room temperature to determine the mechanical properties and behavior of materials used for the thermal protection system of the space shuttle. The materials investigated include the LI-900 RSI tiles, the RTV-560 adhesive and the .41 cm (.16 thick) strain isolator pad (SIP). Tensile and compression cyclic loading tests were conducted on the SIP material and stress-strain curves obtained for various proof loads and load cyclic conditioning. Ultimate tensile and shear tests were conducted on the RSI, RTV, and SIP materials. The SIP material exhibits highly nonlinear stress-strain behavior, increased tangent modulus and ultimate tensile strength with increased loading rate, and large short time load relaxation and moderate creep behavior. Proof and cyclic load conditioning of the SIP results in permanent deformation of the material, hysteresis effects, and much higher tensile tangent modulus values at large strains.

  12. Compression Testing of Textile Composite Materials

    NASA Technical Reports Server (NTRS)

    Masters, John E.

    1996-01-01

    The applicability of existing test methods, which were developed primarily for laminates made of unidirectional prepreg tape, to textile composites is an area of concern. The issue is whether the values measured for the 2-D and 3-D braided, woven, stitched, and knit materials are accurate representations of the true material response. This report provides a review of efforts to establish a compression test method for textile reinforced composite materials. Experimental data have been gathered from several sources and evaluated to assess the effectiveness of a variety of test methods. The effectiveness of the individual test methods to measure the material's modulus and strength is determined. Data are presented for 2-D triaxial braided, 3-D woven, and stitched graphite/epoxy material. However, the determination of a recommended test method and specimen dimensions is based, primarily, on experimental results obtained by the Boeing Defense and Space Group for 2-D triaxially braided materials. They evaluated seven test methods: NASA Short Block, Modified IITRI, Boeing Open Hole Compression, Zabora Compression, Boeing Compression after Impact, NASA ST-4, and a Sandwich Column Test.

  13. Explosive materials equivalency, test methods and evaluation

    NASA Technical Reports Server (NTRS)

    Koger, D. M.; Mcintyre, F. L.

    1980-01-01

    Attention is given to concepts of explosive equivalency of energetic materials based on specific airblast parameters. A description is provided of a wide bandwidth high accuracy instrumentation system which has been used extensively in obtaining pressure time profiles of energetic materials. The object of the considered test method is to determine the maximum output from the detonation of explosive materials in terms of airblast overpressure and positive impulse. The measured pressure and impulse values are compared with known characteristics of hemispherical TNT data to determine the equivalency of the test material in relation to TNT. An investigation shows that meaningful comparisons between various explosives and a standard reference material such as TNT should be based upon the same parameters. The tests should be conducted under the same conditions.

  14. Tactual perception of liquid material properties.

    PubMed

    Bergmann Tiest, Wouter M

    2015-04-01

    In this paper, studies into the tactual perception of two liquid material properties, viscosity and wetness, are reviewed. These properties are very relevant in the context of interaction with liquids, both real, such as cosmetics or food products, and simulated, as in virtual reality or teleoperation. Both properties have been the subject of psychophysical characterisation in terms of magnitude estimation experiments and discrimination experiments, which are discussed. For viscosity, both oral and manual perception is discussed, as well as the perception of the viscosity of a mechanical system. For wetness, the relevant cues are identified and factors affecting perception are discussed. Finally, some conclusions are drawn pertaining to both properties. PMID:25128819

  15. Material Property Characterization of AS4/VRM-34 Textile Laminates

    NASA Technical Reports Server (NTRS)

    Grenoble, Ray W.; Johnston, William M

    2013-01-01

    Several material properties (modulus, strengths, and fracture toughness) of a textile composite have been evaluated to provide input data to analytical models of Pultruded Rod Stiffened Efficient Unitized Structure (PRSEUS). The material system is based on warp-knitted preforms of AS4 carbon fibers and VRM-34 epoxy resin, which have been processed via resin infusion and oven curing. Tensile, compressive, shear, and fracture toughness properties have been measured at ambient and elevated temperatures. All specimens were tested in as-fabricated (dry) condition. Specimens were tested with and without through-thickness stitching.

  16. Ares I-X USS Material Testing

    NASA Technical Reports Server (NTRS)

    Dawicke, David S.; Smith, Stephen W.; Raju, Ivatury S.

    2008-01-01

    An independent assessment was conducted to determine the critical initial flaw size (CIFS) for the flange-to-skin weld in the Ares I-X Upper Stage Simulator (USS). Material characterization tests were conducted to quantify the material behavior for use in the CIFS analyses. Fatigue crack growth rate, Charpy impact, and fracture tests were conducted on the parent and welded A516 Grade 70 steel. The crack growth rate tests confirmed that the material behaved in agreement with literature data and that a salt water environment would not significantly degrade the fatigue resistance. The Charpy impact tests confirmed that the fracture resistance of the material did not have a significant reduction for the expected operational temperatures of the vehicle.

  17. Thermal protection materials: Thermophysical property data

    NASA Technical Reports Server (NTRS)

    Williams, S. D.; Curry, Donald M.

    1992-01-01

    This publication presents a thermophysical property survey on materials that could potentially be used for future spacecraft thermal protection systems (TPS). This includes data that was reported in the 1960's as well as more current information reported through the 1980's. An attempt was made to cite the manufacturers as well as the data source in the bibliography. This volume represents an attempt to provide in a single source a complete set of thermophysical data on a large variety of materials used in spacecraft TPS analysis. The property data is divided into two categories: ablative and reusable. The ablative materials have been compiled into twelve categories that are descriptive of the material composition. An attempt was made to define the Arrhenius equation for each material although this data may not be available for some materials. In a similar manner, char data may not be available for some of the ablative materials. The reusable materials have been divided into three basic categories: thermal protection materials (such as insulators), adhesives, and structural materials.

  18. Materials Compatibility in High Test Hydrogen Peroxide

    NASA Technical Reports Server (NTRS)

    Gostowski, Rudy

    1999-01-01

    Previous ratings of the compatibility of high test hydrogen peroxide (HTP) with materials are not adequate for current needs. The goal of this work was to develop a new scheme of evaluation of compatibility of HTP with various materials. Procedures were developed to enrich commercially available hydrogen peroxide to 90% concentration and to assay the product. Reactivity testing, accelerated aging of materials and calorimetry studies were done on HTP with representative metallic and non-metallic materials. It was found that accelerated aging followed by concentration determination using refractive index effectively discriminated between different Class 2 metallic materials. Preliminary experiments using Differential Scanning Calorimetry (DSC) suggest that a calorimetry experiment is the most sensitive means to assay the compatibility of HTP with materials.

  19. Material properties study of the MJ-2 grout

    SciTech Connect

    Larson, D.B.

    1988-08-01

    Material properties experimental tests using the high pressure testing equipment at LLNL have been performed on the grout used in the Mini Jade-2 event (MJ-2) as part of a high pressure equation of state study sponsored by the Defense Nuclear Agency in support of the Misty Echo experiment at the Nevada Test Site. The material properties tests performed at LLNL and included in this report are (1) pressure-volume compression studies to 3.6 GPa, (2) pressure-volume compression and unloading studies to /approximately/1 GPa, and (3) material strength versus confining pressure to /approximately/1 GPa. These data are compared with dynamic results and with other static data using this grout. 4 refs., 5 figs., 4 tabs.

  20. Electronic materials testing in commercial aircraft engines

    NASA Astrophysics Data System (ADS)

    Brand, Dieter

    A device for the electronic testing of materials used in commercial aircraft engines is described. The instrument can be used for ferromagnetic, ferrimagnetic, and nonferromagnetic metallic materials, and it functions either optically or acoustically. The design of the device is described and technical data are given. The device operates under the principle of controlled self-inductivity. Its mode of operation is described.

  1. Advanced Materials Laboratory User Test Planning Guide

    NASA Technical Reports Server (NTRS)

    Orndoff, Evelyne

    2012-01-01

    Test process, milestones and inputs are unknowns to first-time users of the Advanced Materials Laboratory. The User Test Planning Guide aids in establishing expectations for both NASA and non-NASA facility customers. The potential audience for this guide includes both internal and commercial spaceflight hardware/software developers. It is intended to assist their test engineering personnel in test planning and execution. Material covered includes a roadmap of the test process, roles and responsibilities of facility and user, major milestones, facility capabilities, and inputs required by the facility. Samples of deliverables, test article interfaces, and inputs necessary to define test scope, cost, and schedule are included as an appendix to the guide.

  2. Understanding and Tailoring the Mechanical Properties of LIGA Fabricated Materials

    SciTech Connect

    Buchheit, T.E.; Christenson, T.R.; Lavan, D.A.; Schmale, D.T.

    1999-01-25

    LIGA fabricated materials and components exhibit several processing issues affecting their metallurgical and mechanical properties, potentially limiting their usefulness for MEMS applications. For example, LIGA processing by metal electrodeposition is very sensitive to deposition conditions which causes significant processing lot variations of mechanical and metallurgical properties. Furthermore, the process produces a material with a highly textured lenticular rnicrostructural morphology suggesting an anisotropic material response. Understanding and controlling out-of-plane anisotropy is desirable for LIGA components designed for out-of-plane flexures. Previous work by the current authors focused on results from a miniature servo-hydraulic mechanical test frame constructed for characterizing LIGA materials. Those results demonstrated microstructural and mechanical properties dependencies with plating bath current density in LIGA fabricated nickel (LIGA Ni). This presentation builds on that work and fosters a methodology for controlling the properties of LIGA fabricated materials through processing. New results include measurement of mechanical properties of LIGA fabricated copper (LIGA Cu), out-of-plane and localized mechanical property measurements using compression testing and nanoindentation of LIGA Ni and LIGA Cu.

  3. Oxygen Compatibility Testing of Composite Materials

    NASA Technical Reports Server (NTRS)

    Engel, Carl D.; Watkins, Casey N.

    2006-01-01

    Composite materials offer significant weight-saving potential for aerospace applications in propellant and oxidizer tanks. This application for oxygen tanks presents the challenge of being oxygen compatible in addition to complying with the other required material characteristics. This effort reports on the testing procedures and data obtained in examining and selecting potential composite materials for oxygen tank usage. Impact testing of composites has shown that most of these materials initiate a combustion event when impacted at 72 ft-lbf in the presence of liquid oxygen, though testing has also shown substantial variability in reaction sensitivities to impact. Data for screening of 14 potential composites using the Bruceton method is given herein and shows that the 50-percent reaction frequencies range from 17 to 67 ft-lbf. The pressure and temperature rises for several composite materials were recorded to compare the energy releases as functions of the combustion reactions with their respective reaction probabilities. The test data presented are primarily for a test pressure of 300 psia in liquid oxygen. The impact screening process is compared with oxygen index and autogenous ignition test data for both the composite and the basic resin. The usefulness of these supplemental tests in helping select the most oxygen compatible materials is explored. The propensity for mechanical impact ignition of the composite compared with the resin alone is also examined. Since an ignition-free composite material at the peak impact energy of 72 ft-lbf has not been identified, composite reactivity must be characterized over the impact energy level and operating pressure ranges to provide data for hazard analyses in selecting the best potential material for liquid tank usage.

  4. Cytocompatibility and antibacterial properties of capping materials.

    PubMed

    Poggio, Claudio; Arciola, Carla Renata; Beltrami, Riccardo; Monaco, Annachiara; Dagna, Alberto; Lombardini, Marco; Visai, Livia

    2014-01-01

    The aim of this study was to evaluate and compare the antimicrobial activity and cytocompatibility of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), and Biodentine (Septodont). To evaluate antimicrobial activity, materials were challenged in vitro with Streptococcus mutans, Streptococcus salivarius, and Streptococcus sanguis in the agar disc diffusion test. Cytocompatibility of the assayed materials towards rat MDPC-23 cells was evaluated at different times by both MTT and apoptosis assays. Results significantly differed among the different materials tested. Both bacterial growth inhibition halos and cytocompatibility performances were significantly different among materials with different composition. MTA-based products showed lower cytotoxicity and valuable antibacterial activity, different from calcium hydroxide-based materials, which exhibited not only higher antibacterial activity but also higher cytotoxicity. PMID:24959601

  5. Cytocompatibility and Antibacterial Properties of Capping Materials

    PubMed Central

    Arciola, Carla Renata; Monaco, Annachiara; Lombardini, Marco

    2014-01-01

    The aim of this study was to evaluate and compare the antimicrobial activity and cytocompatibility of six different pulp-capping materials: Dycal (Dentsply), Calcicur (Voco), Calcimol LC (Voco), TheraCal LC (Bisco), MTA Angelus (Angelus), and Biodentine (Septodont). To evaluate antimicrobial activity, materials were challenged in vitro with Streptococcus mutans, Streptococcus salivarius, and Streptococcus sanguis in the agar disc diffusion test. Cytocompatibility of the assayed materials towards rat MDPC-23 cells was evaluated at different times by both MTT and apoptosis assays. Results significantly differed among the different materials tested. Both bacterial growth inhibition halos and cytocompatibility performances were significantly different among materials with different composition. MTA-based products showed lower cytotoxicity and valuable antibacterial activity, different from calcium hydroxide-based materials, which exhibited not only higher antibacterial activity but also higher cytotoxicity. PMID:24959601

  6. CANMET Gasifier Liner Coupon Material Test Report

    SciTech Connect

    Mark Fitzsimmons; Dave Grimmett; Bryan McEnerney

    2007-01-31

    This report provides detailed test results consisting of test data and post-test inspections from Task 1 ''Cooled Liner Coupon Development and Test'' of the project titled ''Development of Technologies and Capabilities for Coal Energy Resources--Advanced Gasification Systems Development (AGSD)''. The primary objective of this development and test program is to verify that ceramic matrix composite (CMC) liner materials planned for use in an advanced gasifier pilot plant will successfully withstand the environments in a commercial gasifier. Pratt & Whitney Rocketdyne (PWR) designed and fabricated the cooled liner test assembly article that was tested in a slagging gasifier at CANMET Energy Technology Center (CETC-O) in Ottawa, Ontario, Canada. The test program conducted in 2006 met the objective of operating the cooled liner test article at slagging conditions in a small scale coal gasifier at CETC-O for over the planned 100 hours. The test hardware was exposed to at least 30 high temperature excursions (including start-up and shut-down cycles) during the test program. The results of the testing has provided valuable information on gasifier startup and required cooling controls in steady state operation of future advanced gasifiers using similar liners. The test program also provided a significant amount of information in the areas of CMC materials and processing for improved capability in a gasifier environment and insight into CMC liner fabrication that will be essential for near-term advanced gasifier projects.

  7. Test Report: Direct and Indirect Lightning Effects on Composite Materials

    NASA Technical Reports Server (NTRS)

    Evans, R. W.

    1997-01-01

    Lightning tests were performed on composite materials as a part of an investigation of electromagnetic effects on the materials. Samples were subjected to direct and remote simulated lightning strikes. Samples included various thicknesses of graphite filament reinforced plastic (GFRP), material enhanced by expanded aluminum foil layers, and material with an aluminum honeycomb core. Shielding properties of the material and damage to the sample surfaces and joints were investigated. Adding expanded aluminum foil layers and increasing the thickness of GFRP improves the shielding effectiveness against lightning induced fields and the ability to withstand lightning strikes. A report describing the lightning strike tests performed by the U.S. Army Redstone Technical Test Center, Redstone Arsenal, AL, STERT-TE-E-EM, is included as an appendix.

  8. 46 CFR 154.430 - Material test.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... SELF-PROPELLED VESSELS CARRYING BULK LIQUEFIED GASES Design, Construction and Equipment Membrane Tanks § 154.430 Material test. (a) The membrane and the membrane supporting insulation must be made of... test for the membrane and the membrane supporting insulation must be submitted to the Commandant...

  9. IHE material qualification tests description and criteria

    SciTech Connect

    Slape, R J

    1984-06-01

    This report describes the qualification tests presently being used at Pantex Plant, Lawrence Livermore National Laboratory, and Los Alamos National Laboratory that are required by the Department of Energy prior to the approval for an explosive as an Insensitive High Explosive (IHE) material. The acceptance criteria of each test for IHE qualification is also discussed. 5 references, 10 figures.

  10. Small crack test program for helicopter materials

    NASA Technical Reports Server (NTRS)

    Annigeri, Bal; Schneider, George

    1994-01-01

    Crack propagation tests were conducted to determine crack growth behavior in five helicopter materials for surface cracks between 0.005 to 0.020 inches in depth. Constant amplitude tests were conducted at stress ratios R equals 0.1 and 0.5, and emphasis was placed on near threshold data (i.e., 10-8 to 10-6 inches/cycle). Spectrum tests were conducted using a helicopter spectrum. The test specimen was an unnotched tension specimen, and cracks were initiated from a small EDM notch. An optical/video system was used to monitor crack growth. The material for the test specimens was obtained from helicopter part forgings. Testing was conducted at stresses below yield to reflect actual stresses in helicopter parts.

  11. CANMET Gasifier Liner Coupon Material Test Plan

    SciTech Connect

    Mark Fitzsimmons; Alan Darby; Fred Widman

    2005-10-30

    The test plan detailed in this topical report supports Task 1 of the project titled ''Development of Technologies and Capabilities for Coal Energy Resources - Advanced Gasification Systems Development (AGSD)''. The purpose of these tests is to verify that materials planned for use in an advanced gasifier pilot plant will withstand the environments in a commercial gasifier. Pratt & Whitney Rocketdyne (PWR) has developed and designed the cooled liner test assembly article that will be tested at CANMET Energy Technology Centre (CETC-O) in Ottawa, Ontario, Canada (CETC-O). The Test Plan TP-00364 is duplicated in its entirety, with formatting changes to comply with the format required for this Topical Report. The table of contents has been modified to include the additional material required by this topical report. Test Request example and drawings of non-proprietary nature are also included as appendices.

  12. Multilayer Pressure Vessel Materials Testing and Analysis Phase 2

    NASA Technical Reports Server (NTRS)

    Popelar, Carl F.; Cardinal, Joseph W.

    2014-01-01

    To provide NASA with a suite of materials strength, fracture toughness and crack growth rate test results for use in remaining life calculations for the vessels described above, Southwest Research Institute® (SwRI®) was contracted in two phases to obtain relevant material property data from a representative vessel. An initial characterization of the strength, fracture and fatigue crack growth properties was performed in Phase 1. Based on the results and recommendations of Phase 1, a more extensive material property characterization effort was developed in this Phase 2 effort. This Phase 2 characterization included additional strength, fracture and fatigue crack growth of the multilayer vessel and head materials. In addition, some more limited characterization of the welds and heat affected zones (HAZs) were performed. This report

  13. Upgrades to the TPSX Material Properties Database

    NASA Technical Reports Server (NTRS)

    Squire, T. H.; Milos, F. S.; Partridge, Harry (Technical Monitor)

    2001-01-01

    The TPSX Material Properties Database is a web-based tool that serves as a database for properties of advanced thermal protection materials. TPSX provides an easy user interface for retrieving material property information in a variety of forms, both graphical and text. The primary purpose and advantage of TPSX is to maintain a high quality source of often used thermal protection material properties in a convenient, easily accessible form, for distribution to government and aerospace industry communities. Last year a major upgrade to the TPSX web site was completed. This year, through the efforts of researchers at several NASA centers, the Office of the Chief Engineer awarded funds to update and expand the databases in TPSX. The FY01 effort focuses on updating correcting the Ames and Johnson thermal protection materials databases. In this session we will summarize the improvements made to the web site last year, report on the status of the on-going database updates, describe the planned upgrades for FY02 and FY03, and provide a demonstration of TPSX.

  14. Coal Ash Corrosion Resistant Materials Testing

    SciTech Connect

    D. K. McDonald; P. L. Daniel; D. J. DeVault

    2003-08-31

    In April 1999, three identical superheater test sections were installed into the Niles Unit No.1 for the purpose of testing and ranking the coal ash corrosion resistance of candidate superheater alloys. The Niles boiler burns high sulfur coal (3% to 3.5%) that has a reasonably high alkali content, thus the constituents necessary for coal ash corrosion are present in the ash. The test sections were controlled to operate with an average surface metal temperature from approximately 1060 F to 1210 F which was well within the temperature range over which coal ash corrosion occurs. Thus, this combination of aggressive environment and high temperature was appropriate for testing the performance of candidate corrosion-resistant tube materials. Analyses of the deposit and scale confirmed that the aggressive alkali-iron-trisulfate constituent was present at the metal surface and active in tube metal wastage. The test sections were constructed so that the response of twelve different candidate tube and/or coating materials could be studied. The plan was to remove and evaluate one of the three test sections at time intervals of 1 year, 3 years, and 5 years. This would permit an assessment of performance of the candidate materials as a function of time. This report provides the results of the evaluation of Test Section C, including the samples that remained in the Test Section for the full exposure period as well as those that were removed early. The analysis of Test Section C followed much the same protocol that was employed in the assessment of Test Section A. Again, the focus was on determining and documenting the relative corrosion rates of the candidate materials. The detailed results of the investigation are included in this report as a series of twelve appendices. Each appendix is devoted to the performance of one of the candidate alloys. The table below summarizes metal loss rate for the worst case sample of each of the candidate materials for both Test Sections A and C

  15. Investigation of test methods, material properties, and processes for solar cell encapsulants. Encapsulation task of the low-cost silicon solar array project

    NASA Technical Reports Server (NTRS)

    1977-01-01

    During this quarter, flat-plate solar collector systems were considered and six basic construction elements were identified: outer coatings, superstrates, pottants, substrates, undercoats, and adhesives. Materials surveys were then initiated to discover either generic classes or/and specific products to function as each construction element. Cost data included in the surveys permit ready evaluation of each material. Silicones, fluorocarbons, glass, and acrylic polymers have the highest inherent weatherability of materials studied to date. Only acrylics, however, combine low costs, environmental resistance, and potential processability. This class will receive particular emphasis.

  16. 14 CFR 23.613 - Material strength properties and design values.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... item is tested before use to determine that the actual strength properties of that particular item will... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Material strength properties and design... Design and Construction § 23.613 Material strength properties and design values. (a) Material...

  17. 14 CFR 23.613 - Material strength properties and design values.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... item is tested before use to determine that the actual strength properties of that particular item will... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Material strength properties and design... Design and Construction § 23.613 Material strength properties and design values. (a) Material...

  18. 14 CFR 23.613 - Material strength properties and design values.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... item is tested before use to determine that the actual strength properties of that particular item will... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Material strength properties and design... Design and Construction § 23.613 Material strength properties and design values. (a) Material...

  19. 14 CFR 23.613 - Material strength properties and design values.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... item is tested before use to determine that the actual strength properties of that particular item will... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Material strength properties and design... Design and Construction § 23.613 Material strength properties and design values. (a) Material...

  20. 14 CFR 23.613 - Material strength properties and design values.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... item is tested before use to determine that the actual strength properties of that particular item will... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Material strength properties and design... Design and Construction § 23.613 Material strength properties and design values. (a) Material...

  1. Oxygen Compatibility Testing of Composite Materials

    NASA Technical Reports Server (NTRS)

    Graf, Neil A.; Hudgins, Richard J.; McBain, Michael

    2000-01-01

    The development of polymer composite liquid oxygen LO2 tanks is a critical step in creating the next generation of launch vehicles. Future launch vehicles need to minimize the gross liftoff weight (GLOW), which is possible due to the 25%-40% reduction in weight that composite materials could provide over current aluminum technology. Although a composite LO2 tank makes these weight savings feasible, composite materials have not historically been viewed as "LO2 compatible." To be considered LO2 compatible, materials must be selected that will resist any type of detrimental, combustible reaction when exposed to usage environments. This is traditionally evaluated using a standard set of tests. However, materials that do not pass the standard tests can be shown to be safe for a particular application. This paper documents the approach and results of a joint NASA/Lockheed Martin program to select and verify LO2 compatible composite materials for liquid oxygen fuel tanks. The test approach developed included tests such as mechanical impact, particle impact, puncture, electrostatic discharge, friction, and pyrotechnic shock. These tests showed that composite liquid oxygen tanks are indeed feasible for future launch vehicles.

  2. Intellectual property analysis of holographic materials business

    NASA Astrophysics Data System (ADS)

    Reingand, Nadya; Hunt, David

    2006-02-01

    The paper presents an overview of intellectual property in the field of holographic photosensitive materials and highlights the possibilities offered by patent searching and analysis. Thousands of patent documents relevant to holographic materials have been uncovered by the study. The search was performed in the following databases: U.S. Patent Office, European Patent Office, and Japanese Patent Office for the time frame of 1971 through November 2005. The patent analysis has unveiled trends in patent temporal distribution, leading IP portfolios, companies competition within the holographic materials market and other interesting insights.

  3. Electromagnetic properties of material coated surfaces

    NASA Technical Reports Server (NTRS)

    Beard, L.; Berrie, J.; Burkholder, R.; Dominek, A.; Walton, E.; Wang, N.

    1989-01-01

    The electromagnetic properties of material coated conducting surfaces were investigated. The coating geometries consist of uniform layers over a planar surface, irregularly shaped formations near edges and randomly positioned, electrically small, irregularly shaped formations over a surface. Techniques to measure the scattered field and constitutive parameters from these geometries were studied. The significance of the scattered field from these geometries warrants further study.

  4. Systems and methods for predicting materials properties

    DOEpatents

    Ceder, Gerbrand; Fischer, Chris; Tibbetts, Kevin; Morgan, Dane; Curtarolo, Stefano

    2007-11-06

    Systems and methods for predicting features of materials of interest. Reference data are analyzed to deduce relationships between the input data sets and output data sets. Reference data includes measured values and/or computed values. The deduced relationships can be specified as equations, correspondences, and/or algorithmic processes that produce appropriate output data when suitable input data is used. In some instances, the output data set is a subset of the input data set, and computational results may be refined by optionally iterating the computational procedure. To deduce features of a new material of interest, a computed or measured input property of the material is provided to an equation, correspondence, or algorithmic procedure previously deduced, and an output is obtained. In some instances, the output is iteratively refined. In some instances, new features deduced for the material of interest are added to a database of input and output data for known materials.

  5. Erosion testing of hard materials and coatings

    SciTech Connect

    Hawk, Jeffrey A.

    2005-04-29

    Erosion is the process by which unconstrained particles, usually hard, impact a surface, creating damage that leads to material removal and component failure. These particles are usually very small and entrained in fluid of some type, typically air. The damage that occurs as a result of erosion depends on the size of the particles, their physical characteristics, the velocity of the particle/fluid stream, and their angle of impact on the surface of interest. This talk will discuss the basics of jet erosion testing of hard materials, composites and coatings. The standard test methods will be discussed as well as alternative approaches to determining the erosion rate of materials. The damage that occurs will be characterized in genera1 terms, and examples will be presented for the erosion behavior of hard materials and coatings (both thick and thin).

  6. SCREENING TESTS FOR IMPROVED METHANE CRACKING MATERIALS

    SciTech Connect

    Klein, J; Jeffrey Holder, J

    2007-07-16

    Bench scale (1 to 6 gram) methane cracking tests have been performed on a variety of pure elements, some alloys, and SAES{reg_sign} commercial getters St 101, St 198, St 707, St 737, and St 909 to determine methane cracking performance (MCP) of 5% methane in a helium carrier at 700 C, 101.3 kPa (760 torr) with a 10 sccm feed. The MCP was almost absent from some materials tested while others showed varying degrees of MCP. Re, Cr, V, Gd, and Mo powders had good MCP, but limited capacities. Nickel supported on kieselguhr (Ni/k), a Zr-Ni alloy, and the SAES{reg_sign} getters had good MCP in a helium carrier. The MCP of these same materials was suppressed in a hydrogen carrier stream and the MCP of the Zr-based materials was reduced by nitride formation when tested with a nitrogen carrier gas.

  7. Estimation of uncertain material parameters using modal test data

    SciTech Connect

    Veers, P.S.; Laird, D.L.; Carne, T.G.; Sagartz, M.J.

    1997-11-01

    Analytical models of wind turbine blades have many uncertainties, particularly with composite construction where material properties and cross-sectional dimension may not be known or precisely controllable. In this paper the authors demonstrate how modal testing can be used to estimate important material parameters and to update and improve a finite-element (FE) model of a prototype wind turbine blade. An example of prototype blade is used here to demonstrate how model parameters can be identified. The starting point is an FE model of the blade, using best estimates for the material constants. Frequencies of the lowest fourteen modes are used as the basis for comparisons between model predictions and test data. Natural frequencies and mode shapes calculated with the FE model are used in an optimal test design code to select instrumentation (accelerometer) and excitation locations that capture all the desired mode shapes. The FE model is also used to calculate sensitivities of the modal frequencies to each of the uncertain material parameters. These parameters are estimated, or updated, using a weighted least-squares technique to minimize the difference between test frequencies and predicted results. Updated material properties are determined for axial, transverse, and shear moduli in two separate regions of the blade cross section: in the central box, and in the leading and trailing panels. Static FE analyses are then conducted with the updated material parameters to determine changes in effective beam stiffness and buckling loads.

  8. Characterization of the physical properties for solid granular materials

    SciTech Connect

    Tucker, Jonathan R.; Shadle, Lawrence J.; Guenther, Chris; Benyahia, Sofiane; Mei, Joseph S.; Banta, Larry

    2012-01-01

    Accurate prediction of the behavior of a system is strongly governed by the components within that system. For multiphase systems incorporating solid powder-like particles, there are many different physical properties which need to be known to some level of accuracy for proper design, modeling, or data analysis. In the past, the material properties were determined initially as a secondary part of the study or design. In an attempt to provide results with the least level of uncertainty, a procedure was developed and implemented to provide consistent analysis of several different types of materials. The properties that were characterized included particle sizing and size distributions, shape analysis, density (particle, skeletal and bulk), minimum fluidization velocities, void fractions, particle porosity, and assignment within the Geldart Classification. In the methods used for this experiment, a novel form of the Ergun equation was used to determine the bulk void fractions and particle density. Materials of known properties were initially characterized to validate the accuracy and methodology, prior to testing materials of unknown properties. The procedures used yielded valid and accurate results, with a high level of repeatability. A database of these materials has been developed to assist in model validation efforts and future designs. It is also anticipated that further development of these procedures wil be expanded increasing the properties included in the database.

  9. Application for managing model-based material properties for simulation-based engineering

    DOEpatents

    Hoffman, Edward L.

    2009-03-03

    An application for generating a property set associated with a constitutive model of a material includes a first program module adapted to receive test data associated with the material and to extract loading conditions from the test data. A material model driver is adapted to receive the loading conditions and a property set and operable in response to the loading conditions and the property set to generate a model response for the material. A numerical optimization module is adapted to receive the test data and the model response and operable in response to the test data and the model response to generate the property set.

  10. Principles for supplying virus-tested material.

    PubMed

    Varveri, Christina; Maliogka, Varvara I; Kapari-Isaia, Theodora

    2015-01-01

    Production of virus-tested material of vegetatively propagated crops through national certification schemes has been implemented in many developed countries for more than 60 years and its importance for being the best virus control means is well acknowledged by growers worldwide. The two most important elements of certification schemes are the use of sensitive, reliable, and rapid detection techniques to check the health status of the material produced and effective and simple sanitation procedures for the elimination of viruses if present in candidate material before it enters the scheme. New technologies such as next-generation sequencing platforms are expected to further enhance the efficiency of certification and production of virus-tested material, through the clarification of the unknown etiology of several graft-transmissible diseases. The successful production of virus-tested material is a demanding procedure relying on the close collaboration of researchers, official services, and the private sector. Moreover, considerable efforts have been made by regional plant protection organizations such as the European and Mediterranean Plant Protection Organization (EPPO), the North American Plant Protection Organization (NAPPO), and the European Union and the USA to harmonize procedures, methodologies, and techniques in order to assure the quality, safety, and movement of the vegetatively propagated material produced around the world. PMID:25591875

  11. Offgassing test methodology for composite materials

    NASA Technical Reports Server (NTRS)

    Scheer, Dale A.

    1994-01-01

    A significant increase in the use of composite materials has occurred during the past 20 years. Associated with this increased use is the potential for employees to be exposed to offgassing components from composite systems. Various components in composite systems, particularly residual solvents, offgas under various conditions. The potential for offgassing to occur increases as a composite material is heated either during cure or during lay-up operations. Various techniques can be employed to evaluate the offgassing characteristics of a composite system. A joint effort between AIA and SACMA resulted in the drafting of a proposed test method for evaluating the offgassing potential of composite materials. The purpose of testing composite materials for offgassing is to provide the industrial hygienist with information which can be used to assess the safety of the workplace. This paper outlines the proposed test method and presents round robin testing data associated with the test method. Also in this presentation is a discussion of classes of compounds which require specialized sampling techniques.

  12. Using Virtual Testing for Characterization of Composite Materials

    NASA Astrophysics Data System (ADS)

    Harrington, Joseph

    Composite materials are finally providing uses hitherto reserved for metals in structural systems applications -- airframes and engine containment systems, wraps for repair and rehabilitation, and ballistic/blast mitigation systems. They have high strength-to-weight ratios, are durable and resistant to environmental effects, have high impact strength, and can be manufactured in a variety of shapes. Generalized constitutive models are being developed to accurately model composite systems so they can be used in implicit and explicit finite element analysis. These models require extensive characterization of the composite material as input. The particular constitutive model of interest for this research is a three-dimensional orthotropic elasto-plastic composite material model that requires a total of 12 experimental stress-strain curves, yield stresses, and Young's Modulus and Poisson's ratio in the material directions as input. Sometimes it is not possible to carry out reliable experimental tests needed to characterize the composite material. One solution is using virtual testing to fill the gaps in available experimental data. A Virtual Testing Software System (VTSS) has been developed to address the need for a less restrictive method to characterize a three-dimensional orthotropic composite material. The system takes in the material properties of the constituents and completes all 12 of the necessary characterization tests using finite element (FE) models. Verification and validation test cases demonstrate the capabilities of the VTSS.

  13. Durability Testing of Commercial Ceramic Materials

    NASA Technical Reports Server (NTRS)

    Schienle, J. L.

    1996-01-01

    Technical efforts by AlliedSignal Engines in DOE/NASA-funded project from February, 1978 through December, 1995 are reported in the fields ceramic materials for gas turbine engines and cyclic thermal durability testing. A total of 29 materials were evaluated in 40 cyclic oxidation exposure durability tests. Ceramic test bars were cyclically thermally exposed to a hot combustion environment at temperatures up to 1371 C (2500 F) for periods of up to 3500 hours, simulating conditions typically encountered by hot flowpath components in an automotive gas turbine engine. Before and after exposure, quarter-point flexure strength tests were performed on the specimens, and fractography examinations including scanning electron microscopy (SEM) were performed to determine failure origins.

  14. Characterization of Viscoelastic Properties of Polymeric Materials Through Nanoindentation

    NASA Technical Reports Server (NTRS)

    Odegard, G. M.; Bandorawalla, T.; Herring, H. M.; Gates, T. S.

    2003-01-01

    Nanoindentation is used to determine the dynamic viscoelastic properties of six polymer materials. It is shown that varying the harmonic frequency of the nanoindentation does not have any significant effect on the measured storage and loss moduli of the polymers. Agreement is found between these results and data from DMA testing of the same materials. Varying the harmonic amplitude of the nanoindentation does not have a significant effect on the measured properties of the high performance resins, however, the storage modulus of the polyethylene decreases as the harmonic amplitude increases. Measured storage and loss moduli are also shown to depend on the density of the polyethylene.

  15. Impact testing of textile composite materials

    NASA Technical Reports Server (NTRS)

    Portanova, Marc

    1995-01-01

    The objectives of this report were to evaluate the impact damage resistance and damage tolerance of a variety of textile composite materials. Static indentation and impact tests were performed on the stitched and unstitched uniweave composites constructed from AS4/3501-6 Carbon/Epoxy with a fiberglass yarn woven in to hold the fibers together while being stitched. Compression and tension were measured after the tests to determine the damage resistance, residual strength and the damage tolerance of the specimens.

  16. Coal Ash Corrosion Resistant Materials Testing Program

    SciTech Connect

    McDonald, D K

    2003-04-22

    The "Coal Ash Corrosion Resistant Materials Testing Program" is being conducted by The Babcock & Wilcox Company (B&W), the U.S. Department of Energy (DOE) and the Ohio Coal Development Office (OCDO) at Reliant Energy's Niles plant in Niles, Ohio to provide full-scale, in-situ testing of recently developed boiler superheater materials. Fireside corrosion is a key issue for improving efficiency of new coal fired power plants and improving service life in existing plants. In November 1998, B&W began development of a system to permit testing of advanced tube materials at metal temperatures typical of advanced supercritical steam temperatures (1100°F and higher) in a boiler exhibiting coal ash corrosive conditions. Several materials producers including Oak Ridge National Laboratory (ORNL) contributed advanced materials to the project. In the spring of 1999 a system consisting of three identical sections, each containing multiple segments of twelve different materials, was installed. The sections are cooled by reheat steam, and are located just above the furnace entrance in Niles' Unit #1, a 110 MWe unit firing high sulfur Ohio coal. In November 2001 the first section was removed for thorough metallurgical evaluation after 33 months of operation. The second and third sections remain in service and the second is expected to be removed in the fall of 2003; the last is tentatively planned for the fall of 2004. This paper describes the program; its importance; the design, fabrication, installation and operation of the test system; materials utilized; experience to date; and results of the evaluation of the first section.

  17. Multilayer Pressure Vessel Materials Testing and Analysis. Phase 1

    NASA Technical Reports Server (NTRS)

    Cardinal, Joseph W.; Popelar, Carl F.; Page, Richard A.

    2014-01-01

    To provide NASA a comprehensive suite of materials strength, fracture toughness and crack growth rate test results for use in remaining life calculations for aging multilayer pressure vessels, Southwest Research Institute (R) (SwRI) was contracted in two phases to obtain relevant material property data from a representative vessel. This report describes Phase 1 of this effort which includes a preliminary material property assessment as well as a fractographic, fracture mechanics and fatigue crack growth analyses of an induced flaw in the outer shell of a representative multilayer vessel that was subjected to cyclic pressure test. SwRI performed this Phase 1 effort under contract to the Digital Wave Corporation in support of their contract to Jacobs ATOM for the NASA Ames Research Center.

  18. Tailoring of materials properties under extreme conditions

    NASA Astrophysics Data System (ADS)

    Schenkel, Thomas

    Materials can be driven far from equilibrium e. g. with intense pules of lasers and ions, in mostly destructive processes. When combined with micro- and nano-structuring, the ability to rapidly excite and then quench local excitations opens up. Now opportunities emerge to form and stabilize novel materials phases and to tailor materials properties for applications. Examples are color centers in diamond and silicon carbide for sensing and qubit applications and proposed ordered dopant structures in cuprate superconductors. Results from studies of materials processing under transient extreme conditions, far from equilibrium will be presented. This work was supported by the Director, Office of Science, Office of Fusion Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

  19. Moisture effect on mechanical properties of polymeric composite materials

    NASA Astrophysics Data System (ADS)

    Airale, A. G.; Carello, M.; Ferraris, A.; Sisca, L.

    2016-05-01

    The influence of moisture on the mechanical properties of fibre-reinforced polymer matrix composites (PMCs) was investigated. Four materials had been take into account considering: both 2×2-Twill woven carbon fibre or glass fibre, thermosetting matrix (Epoxy Resin) or thermoplastic matrix (Polyphenylene Sulfide). The specimens were submitted for 1800 hours to a hygrothermic test to evaluate moisture absorption on the basis of the Fick's law and finally tested to verify the mechanical properties (ultimate tensile strength). The results showed that the absorbed moisture decreases those properties of composites which were dominated by the matrix or the interface, while was not detectable the influence of water on the considered fibre. An important result is that the diffusion coefficient is highest for glass/PPS and lowest for carbon/epoxy composite material. The results give useful suggestions for the design of vehicle components that are exposed to environmental conditions (rain, snow and humidity).

  20. Materials property definition and generation for carbon-carbon and carbon phenolic materials

    NASA Technical Reports Server (NTRS)

    Canfield, A. R.; Mathis, J. R.; Starrett, H. S.; Koenig, J. R.

    1987-01-01

    A data base program to generate statistically significant material-property data for carbon-carbon and carbon phenolic materials to be used in designs of Space Shuttle is described. The program, which will provide data necessary for thermal and stress modeling of Shuttle nozzle and exit cone structures, includes evaluation of tension, compression, shear strength, shear modulus, thermal expansion, thermal conductivity, permeability, and emittance for both materials; the testing of carbon phenolic materials also includes CTE, off-gassing, pyrolysis, and RTG. Materials to be tested will be excised from Space Shuttle inlet, throat, and exit cone billets and modified involute carbon-carbon exit cones; coprocessed blocks, panels, and cylinders will also be tested.

  1. Molecular properties of polymeric materials for space applications

    NASA Technical Reports Server (NTRS)

    Harries, Wynford L.; Kern, Kristen T.; Stancil, Phillip C.

    1992-01-01

    This cooperative agreement was intended to investigate the effects of a space environment on the properties of polymeric materials. In addition, efforts have been made to understand and investigate environment simulation techniques and test methodology. The results identified the changes in the properties of six aerospace structural adhesives, three neat high polymers, and two fiber-reinforced polymers, as caused by exposure to four simulated space environmental conditions. Significant property changes occurred for several of the systems as a result of one or more of the exposures. A summary of the research follows a list of related publications and presentations.

  2. Recent developments in dynamic testing of materials

    NASA Astrophysics Data System (ADS)

    Gilat, Amos; Seidt, Jeremy D.

    2015-09-01

    New techniques for dynamic characterization of materials that have been developed in the last three years (since the last DYMAT conference in 2012), and results from recent dynamic testing of Inconel 718 are presented. The first development is a dynamic punch test in which three dimensional Digital Image Correlation (DIC) is used to measure the deformation of the rear surface of a specimen as it being penetrated. The second experimental technique that is under development is a dynamic tension experiment in which full-field strain measurement with DIC and full-field temperature measurement are done simultaneously during the test.

  3. Thermoelastic analysis of solar cell arrays and their material properties

    NASA Technical Reports Server (NTRS)

    Salama, M. A.; Rowe, W. M.; Yasui, R. K.

    1974-01-01

    Description of a thermoelastic stress analysis procedure for predicting the thermally induced stresses and failures in silicon solar cell arrays. A prerequisite for the analysis is the characterization of the temperature-dependent thermal and mechanical properties of the solar cell materials. Extensive material property testing was carried out in the temperature range from -200 to +200 C for the filter glass, P- and N-type silicon, interconnector metals, solder, and several candidate silicone rubber adhesives. The analysis procedure is applied to several solar cell array design configurations, which were tested in the Space Molecular Sink. Results of the analysis indicate the optimum design configuration with respect to materials and geometry, effect of the solder coating, and effect of the interconnector geometry.

  4. Thermoelastic analysis of solar cell arrays and their material properties

    NASA Technical Reports Server (NTRS)

    Salama, M. A.; Rowe, W. M.; Yasui, R. K.

    1973-01-01

    A thermoelastic stress analysis procedure is reported for predicting the thermally induced stresses and failures in silicon solar cell arrays. A prerequisite for the analysis is the characterization of the temperature-dependent thermal and mechanical properties of the solar cell materials. Extensive material property testing was carried out in the temperature range -200 to +200 C for the filter glass, P- and N-type silicon, interconnector metals, solder, and several candidate silicone rubber adhesives. The analysis procedure is applied to several solar cell array design configurations. Results of the analysis indicate the optimum design configuration, with respect to compatible materials, effect of the solder coating, and effect of the interconnector geometry. Good agreement was found between results of the analysis and the test program.

  5. Automation software for a materials testing laboratory

    NASA Technical Reports Server (NTRS)

    Mcgaw, Michael A.; Bonacuse, Peter J.

    1990-01-01

    The software environment in use at the NASA-Lewis Research Center's High Temperature Fatigue and Structures Laboratory is reviewed. This software environment is aimed at supporting the tasks involved in performing materials behavior research. The features and capabilities of the approach to specifying a materials test include static and dynamic control mode switching, enabling multimode test control; dynamic alteration of the control waveform based upon events occurring in the response variables; precise control over the nature of both command waveform generation and data acquisition; and the nesting of waveform/data acquisition strategies so that material history dependencies may be explored. To eliminate repetitive tasks in the coventional research process, a communications network software system is established which provides file interchange and remote console capabilities.

  6. Double Retort System for Materials Compatibility Testing

    SciTech Connect

    V. Munne; EV Carelli

    2006-02-23

    With Naval Reactors (NR) approval of the Naval Reactors Prime Contractor Team (NRPCT) recommendation to develop a gas cooled reactor directly coupled to a Brayton power conversion system as the Space Nuclear Power Plant (SNPP) for Project Prometheus (References a and b) there was a need to investigate compatibility between the various materials to be used throughout the SNPP. Of particular interest was the transport of interstitial impurities from the nickel-base superalloys, which were leading candidates for most of the piping and turbine components to the refractory metal alloys planned for use in the reactor core. This kind of contamination has the potential to affect the lifetime of the core materials. This letter provides technical information regarding the assembly and operation of a double retort materials compatibility testing system and initial experimental results. The use of a double retort system to test materials compatibility through the transfer of impurities from a source to a sink material is described here. The system has independent temperature control for both materials and is far less complex than closed loops. The system is described in detail and the results of three experiments are presented.

  7. Testing of SRS and RFETS Nylon Bag Material

    SciTech Connect

    Laurinat, J.E.

    1998-11-03

    This report compares the effects of radiation and heating on nylon bagout materials used at the Savannah River Site (SRS) and the Rocky Flats Environmental Technology Site (RFETS). Recently, to simplify the processing of sand, slag, and crucible (SS and C), FB-Line has replaced the low-density polyethylene (LDPE) and polyvinyl chloride (PVC) bags normally used to package cans of plutonium-bearing material with nylon bags. LDPE and PVC are not soluble in the nitric acid dissolver solution used in F-Canyon, so cans bagged using these materials had to be repackaged before they were added to the dissolver. Because nylon dissolves in nitric acid, cans bagged in nylon can be charged to the F-Canyon dissolvers without repackaging, thereby reducing handling requirements and personnel exposure. As part of a program to process RFETS SS and C at SRS, RFETS has also begun to use a nylon bagout material. The RFETS bag materials is made from a copolymer of nylon 6 and nylon 6.9, while the SRS material is made from a nylon 6 monomer. In addition, the SRS nylon has an anti-static agent added. The RFETS nylon is slightly softer than the SRS nylon, but does not appear to be as resistant to flex cracks initiated by contact with sharp corners of the inner can containing the SS and C.2 FB-Line Operations has asked for measurement of the effects of radiation and heating on these materials. Specifically, they have requested a comparison of the material properties of the plastics before and after irradiation, a measurement of the amount of outgassing when the plastics are heated, and a calculation of the amount of radiolytic gas generation. Testing was performed on samples taken from material that is currently used in FB-Line (color coded orange) and at RFETS. The requested tests are the same tests previously performed on the original and replacement nylon and LDPE bag materials.3,4,5. To evaluate the effect of irradiation on material properties, tensile stresses and elongations to break

  8. Temperature dependent phonon properties of thermoelectric materials

    NASA Astrophysics Data System (ADS)

    Hellman, Olle; Broido, David; Fultz, Brent

    2015-03-01

    We present recent developments using the temperature dependent effective potential technique (TDEP) to model thermoelectric materials. We use ab initio molecular dynamics to generate an effective Hamiltonian that reproduce neutron scattering spectra, thermal conductivity, phonon self energies, and heat capacities. Results are presented for (among others) SnSe, Bi2Te3, and Cu2Se proving the necessity of careful modelling of finite temperature properties for strongly anharmonic materials. Supported by the Swedish Research Council (VR) Project Number 637-2013-7296.

  9. First principles simulation of materials properties

    SciTech Connect

    Shelton, W.A.; Stocks, G.M.; Pinski, F.J.; Jordan, R.G.; Liu, Y.; Qui, L.L.; Staunton, J.B.; Johnson, D.D.; Ginatempo, B.

    1994-06-01

    We have developed a hybrid, parallel computer code for calculating the electronic structure of both ordered and substitutionally disordered materials. By using PVM3.3, we can integrate into our local computer environment multiple parallel and vector superconductors as well as high performance workstations. Without this approach, calculations of materials properties of large systems would be otherwise untenable due to a lack of computer resources. For example, we have determined the short-range order intensity and its electronic origin for the Ag-Mg alloy system, including an estimate of the order-disorder (spinodal) temperature.

  10. First principles simulation of materials properties

    SciTech Connect

    Shelton, W.A.; Stocks, G.M.; Jordan, R.G.; Liu, Y.; Qui, L.; Johnson, D.D.; Pinski, F.J.; Staunton, J.B.; Ginatempo, B.

    1994-08-01

    We have developed a hybrid, parallel computer code for calculating the electronic structure of both ordered and substitutionally disordered materials. By using PVM3.3, we can integrate into our local computer environment multiple parallel and vector supercomputers as well as high performance workstations. Without this approach, calculations of materials properties of large systems would be otherwise untenable due to a lack of computer resources. For example, we have determined the short-range order intensity and its electronic origin for the Ag-Mg alloy system, including an estimate of the order-disorder (spinodal) temperature.

  11. Nuclear waste package materials testing report: basaltic and tuffaceous environments

    SciTech Connect

    Bradley, D.J.; Coles, D.G.; Hodges, F.N.; McVay, G.L.; Westerman, R.E.

    1983-03-01

    The disposal of high-level nuclear wastes in underground repositories in the continental United States requires the development of a waste package that will contain radionuclides for a time period commensurate with performance criteria, which may be up to 1000 years. This report addresses materials testing in support of a waste package for a basalt (Hanford, Washington) or a tuff (Nevada Test Site) repository. The materials investigated in this testing effort were: sodium and calcium bentonites and mixtures with sand or basalt as a backfill; iron and titanium-based alloys as structural barriers; and borosilicate waste glass PNL 76-68 as a waste form. The testing also incorporated site-specific rock media and ground waters: Reference Umtanum Entablature-1 basalt and reference basalt ground water, Bullfrog tuff and NTS J-13 well water. The results of the testing are discussed in four major categories: Backfill Materials: emphasizing water migration, radionuclide migration, physical property and long-term stability studies. Structural Barriers: emphasizing uniform corrosion, irradiation-corrosion, and environmental-mechanical testing. Waste Form Release Characteristics: emphasizing ground water, sample surface area/solution volume ratio, and gamma radiolysis effects. Component Compatibility: emphasizing solution/rock, glass/rock, glass/structural barrier, and glass/backfill interaction tests. This area also includes sensitivity testing to determine primary parameters to be studied, and the results of systems tests where more than two waste package components were combined during a single test.

  12. Encapsulation task of the low-cost silicon solar array project. Investigation of test methods, material properties, and processes for solar cell encapsulants

    NASA Technical Reports Server (NTRS)

    Willis, P. B.; Baum, B.; White, R. A.

    1978-01-01

    The results of an investigation of solar module encapsulation systems applicable to the Low-Cost Solar Array Project 1986 cost and performance goals are presented. Six basic construction elements were identified and their specific uses in module construction defined. A uniform coating basis was established for each element. The survey results were also useful in revealing price ranges for classes of materials and estimating the cost allocation for each element within the encapsulating cost goal. The six construction elements were considered to be substrates, superstrates, pottants, adhesives, outer covers and back covers.

  13. MISSE 6-Testing Materials in Space

    NASA Technical Reports Server (NTRS)

    Prasad, Narasimha S; Kinard, William H.

    2008-01-01

    The objective of the Materials International Space Station Experiment (MISSE) is to study the performance of novel materials when subjected to the synergistic effects of the harsh space environment by placing them in space environment for several months. In this paper, a few materials and components from NASA Langley Research Center (LaRC) that have been flown on MISSE 6 mission will be discussed. These include laser and optical elements for photonic devices. The pre-characterized MISSE 6 materials were packed inside a ruggedized Passive Experiment Container (PEC) that resembles a suitcase. The PEC was tested for survivability due to launch conditions. Subsequently, the MISSE 6 PEC was transported by the STS-123 mission to International Space Station (ISS) on March 11, 2008. The astronauts successfully attached the PEC to external handrails and opened the PEC for long term exposure to the space environment.

  14. Cyclic cryopreservation affects the nanoscale material properties of trabecular bone.

    PubMed

    Landauer, Alexander K; Mondal, Sumona; Yuya, Philip A; Kuxhaus, Laurel

    2014-11-01

    Tissues such as bone are often stored via freezing, or cryopreservation. During an experimental protocol, bone may be frozen and thawed a number of times. For whole bone, the mechanical properties (strength and modulus) do not significantly change throughout five freeze-thaw cycles. Material properties at the trabecular and lamellar scales are distinct from whole bone properties, thus the impact of freeze-thaw cycling at this scale is unknown. To address this, the effect of repeated freezing on viscoelastic material properties of trabecular bone was quantified via dynamic nanoindentation. Vertebrae from five cervine spines (1.5-year-old, male) were semi-randomly assigned, three-to-a-cycle, to 0-10 freeze-thaw cycles. After freeze-thaw cycling, the vertebrae were dissected, prepared and tested. ANOVA (factors cycle, frequency, and donor) on storage modulus, loss modulus, and loss tangent, were conducted. Results revealed significant changes between cycles for all material properties for most cycles, no significant difference across most of the dynamic range, and significant differences between some donors. Regression analysis showed a moderate positive correlation between cycles and material property for loss modulus and loss tangent, and weak negative correlation for storage modulus, all correlations were significant. These results indicate that not only is elasticity unpredictably altered, but also that damping and viscoelasticity tend to increase with additional freeze-thaw cycling. PMID:25278046

  15. The Evaluation of Flammability Properties Regarding Testing Methods

    NASA Astrophysics Data System (ADS)

    Osvaldová, Linda Makovická; Gašpercová, Stanislava

    2015-12-01

    In this paper, we address the historical comparison methods with current methods for the assessment of flammability characteristics for materials an especially for wood, wood components and wooden buildings. Nowadays in European Union brings harmonization in evaluated of standards into each European country and try to make one concept of evaluated the flammability properties. In each European country to the one standard level which will be used by evaluation of materials regarding flammability. In our article we focused mainly on improving the evaluation methods in terms of flammability characteristics of using materials at building industry. In the article we present examples of different assessment methods at their own test methods in terms of fire prevention. On the base of old compared of materials by STN, BS and DIN methods for testing materials on fire and new methods of evaluating the flammability properties regarding EU standards before and after starting the flash over.

  16. Elastic therapeutic tape: do they have the same material properties?

    PubMed

    Boonkerd, Chuanpis; Limroongreungrat, Weerawat

    2016-04-01

    [Purpose] Elastic therapeutic tape has been widely used for rehabilitation and treatment of sports injuries. Tapes with different elastic properties serve different treatment purposes with inappropriate tension reducing tape effectiveness. Many tapes are available in the market, but studies on tape properties are limited. The aim of this study was to examine the material properties of elastic therapeutic tape. [Subjects and Methods] Brands of elastic therapeutic tape included KinesioTex(®), ATex, Mueller, 3M, and ThaiTape. The Material Testing System Insight(®) 1 Electromechanical Testing Systems was used to apply a tensile force on elastic therapeutic tape. Ten specimens of each brand were tested. Stress, load, and Young's modulus at 25%, 50%, 75%, 100%, and maximum point were collected. One-way analysis of variance with post hoc testing was used to analyze tape parameters. [Results] Maximum elongation and Young's modulus at all percentages were significantly different between brands. There were no differences in maximum load and maximum stress. [Conclusion] Mechanical properties are different for commercial elastic therapeutic tapes. Physiotherapists and other clinicians should be aware of mechanical tape properties to correctly apply kinesio tape. PMID:27190472

  17. Elastic therapeutic tape: do they have the same material properties?

    PubMed Central

    Boonkerd, Chuanpis; Limroongreungrat, Weerawat

    2016-01-01

    [Purpose] Elastic therapeutic tape has been widely used for rehabilitation and treatment of sports injuries. Tapes with different elastic properties serve different treatment purposes with inappropriate tension reducing tape effectiveness. Many tapes are available in the market, but studies on tape properties are limited. The aim of this study was to examine the material properties of elastic therapeutic tape. [Subjects and Methods] Brands of elastic therapeutic tape included KinesioTex®, ATex, Mueller, 3M, and ThaiTape. The Material Testing System Insight® 1 Electromechanical Testing Systems was used to apply a tensile force on elastic therapeutic tape. Ten specimens of each brand were tested. Stress, load, and Young’s modulus at 25%, 50%, 75%, 100%, and maximum point were collected. One-way analysis of variance with post hoc testing was used to analyze tape parameters. [Results] Maximum elongation and Young’s modulus at all percentages were significantly different between brands. There were no differences in maximum load and maximum stress. [Conclusion] Mechanical properties are different for commercial elastic therapeutic tapes. Physiotherapists and other clinicians should be aware of mechanical tape properties to correctly apply kinesio tape. PMID:27190472

  18. Using Mathematical Methods to Compensate for Problems Resulting from Differences in Material Properties for Remote-Field Eddy Current Testing in Tubes

    NASA Astrophysics Data System (ADS)

    Jeng, Jin-Jhy

    2005-06-01

    Remote-field eddy current (RFEC) testing is a nondestructive testing method. It has been comprehensively applied to detect wall loss in ferromagnetic tubes. According to our experience, the problem of variations in a material’s electromagnetic characteristics often occurred in practice in carbon steel tubes. Therefore, if we fail to compensate for changes in electromagnetic characteristics during inspection, an error of evaluation will be generated. This study applied the skin-depth theory of RFEC and geometric relationships on the voltage plane to derive a compensatory model using a mathematical methodology. The new evaluation curve established on the basis of this mathematical methodology compensates for the error contributed by changing electromagnetic characteristics in the tube. The method offered by this study has proved to be reasonable, feasible and acceptable in terms of its mathematical derivation and in comparison with experimental result.

  19. DIELECTRIC PROPERTIES OF VARIOUS NANOCOMPOSITE MATERIALS

    SciTech Connect

    Tuncer, E.; Polizos, G.; James, D. R.; Sauers, I.; Ellis, A. R.; More, K. L.

    2010-01-01

    Composite materials based on polymers are used in various engineering applications due to their ability to be tailored for a specific application. As a result a composite could be selected or designed for a high performance part such as field grading applications in high voltage technology. Presently, there exists no commercially available material for electric field control. For this reason in this study we characterize a polymeric system composed of a thermoplast polymer filled with nanometer size ceramic particles. Since it is hard to tailor or to predict properties of composites theoretically, an Edisonian approach is employed. Composites with different filler weight concentrations are prepared and their dielectric performance are characterized. Impedance spectroscopy technique at a constant frequency is used to determine the dielectric properties of the composites at low temperatures. Measurement results and potential applications of the composite systems are presented.

  20. Dielectric properties of various nanocomposite materials

    SciTech Connect

    Tuncer, Enis; Polyzos, Georgios; James, David Randy; Sauers, Isidor; Ellis, Alvin R; More, Karren Leslie

    2010-01-01

    Composite materials based on polymers are used in various engineering applications due to their ability to be tailored for a specific application. As a result a composite could be selected or designed for a high performance part such as field grading applications in high voltage technology. Presently, there exists no commercially available material for electric field control. For this reason in this study we characterize a polymeric system composed of a thermoplast polymer filled with nanometer size ceramic particles. Since it is hard to tailor or to predict properties of composites theoretically, an Edisonian approach is employed. Composites with different filler weight concentrations are prepared and their dielectric performance are characterized. Impedance spectroscopy technique at a constant frequency is used to determine the dielectric properties of the composites at low temperatures. Measurement results and potential applications of the composite systems are presented.

  1. Investigation of test methods, material properties, and processes for solar cell encapsulants. Seventeenth quarterly progress report, May 12-August 12, 1980

    SciTech Connect

    Willis, P. B.; Baum, B.

    1980-09-01

    The goal of this program is to identify, evaluate, and recommend encapsulant materials and processes for the production of cost-effective, long-life solar cell modules. Development efforts have emphasized the reformulation of polybutyl acrylate, a liquid pottant used in the casting encapsulation process. This material has been modified to yield a composition with much faster cure at lower temperatures. Minimodules have been successfully prepared from this low cost compound and are currently being evaluated by thermal/humidity cycling. Differential thermal analysis (DTA) was used for the examination of thermal stability in some of the pottant compounds of current interest. This method was useful in determining the temperatures at which oxidative or pyrolysis reactions resulted in degradation of the polymers. All the candidate pottants showed degradation onsets of over 200/sup 0/C. The effectiveness of a new primer was determined during this period. This formulation was similar to the silane coupling agent used in past experimentation but was modified with a peroxide to enhance the activity. Excellent bound strengths were obtained to glass, and mild steel that were resistant to immersion in boiling water. EVA to low iron glass gave an average bond strength of 35 lbs per inch of width. This new primer was also evaluated for the corrosion protection that could be provided to metal surfaces when primed and encapsulated in EVA. (WHK)

  2. Fabrication, properties, and tritium recovery from solid breeder materials

    SciTech Connect

    Johnson, C.E. ); Kondo, T. ); Roux, N. ); Tanaka, S. ); Vollath, D. )

    1991-01-01

    The breeding blanket is a key component of the fusion reactor because it directly involves tritium breeding and energy extraction, both of which are critical to development of fusion power. The lithium ceramics continue to show promise as candidate breeder materials. This promise was recognized by the International Thermonuclear Experimental Reactor (ITER) design team in its selection of ceramics as the first option for the ITER breeder material. Blanket design studies have indicated properties in the candidate materials data base that need further investigation. Current studies are focusing on tritium release behavior at high burnup, changes in thermophysical properties with burnup, compatibility between the ceramic breeder and beryllium multiplier, and phase changes with burnup. Laboratory and in-reactor tests, some as part of an international collaboration for development of ceramic breeder materials, are underway. 133 refs., 1 fig.

  3. Optical properties of photochromic and thermochromic materials

    NASA Astrophysics Data System (ADS)

    Mo, Yeon-Gon

    The optical properties of some thin film materials can be altered by an external stimulus. Photochromic and thermochromic materials, including inorganic and organic substances, have optical properties that can be changed in a reversible manner by irradiation and temperature respectively. These materials can be used in applications such as radiation or thermal sensors, information storage devices and smart window applications in buildings and cars. In this work, major effort was concentrated on passive thermal control coatings based on photochromic and thermochromic materials. The inorganic photochromic materials were based on tungsten and molybdenum oxide films and the organic photochromic materials included spiropyrans and spirooxazines. In addition, photochromic composite organic-inorganic films and thermochromic vanadium oxide films were prepared. The samples were synthesized using sputtering, sol-gel process, and thermal oxidation. The optical properties were investigated for the first time by ultraviolet/visible/infrared (UV/VIS/IR) spectroscopic ellipsometry, attenuated total reflection (ATR) infrared ellipsometry, spectrophotometry, and X-ray diffraction (XRD). For amorphous oxide films, the oxygen deficiency was important in determining the photochromic properties of the films. In the mid-infrared region, no photochromism was observed for the films. The optical properties of organic-inorganic composite films changed in the VIS/NIR wavelength region markedly in a reversible process, with UV irradiation. The composite films containing tungsten heteropolyoxometalate (HPOM) showed faster coloration and bleaching than pure tungsten oxide films. The composite films with molybdenum HPOM showed faster coloration and much slower bleaching than tungsten HPOM. The spiropyran and spirooxazine doped polymeric films were investigated for the first time using infrared and ATR ellipsometry. The infrared optical functions obtained by ATR measurements were a little smaller

  4. Coal Ash Corrosion Resistant Materials Testing

    SciTech Connect

    D. K. McDonald; P. L. Daniel; D. J. DeVault

    2007-12-31

    In April 1999, three identical superheater test sections were installed into the Niles Unit No.1 for the purpose of testing and ranking the coal ash corrosion resistance of candidate superheater alloys. The Niles boiler burns high sulfur coal (3% to 3.5%) that has a moderate alkali content (0.2% sodium equivalents), thus the constituents necessary for coal ash corrosion are present in the ash. The test sections were controlled to operate with an average surface metal temperature from approximately 1060 F to 1210 F which was within the temperature range over which coal ash corrosion occurs. Thus, this combination of aggressive environment and high temperature was appropriate for testing the performance of candidate corrosion-resistant tube materials. Analyses of the deposit and scale confirmed that aggressive alkali sulfate constituents were present at the metal surface and active in tube metal wastage. The test sections were constructed so that the response of twelve different candidate tube and/or coating materials could be studied. The plan was to remove and evaluate one of the three test sections at time intervals of 1 year, 3 years, and 5 years. This would permit an assessment of performance of the candidate materials as a function of time. Test Section A was removed in November 2001 after about 24 months of service at the desired steam temperature set point, with about 15.5 months of exposure at full temperature. A progress report, issued in October 2002, was written to document the performance of the candidate alloys in that test section. The evaluation described the condition of each tube sample after exposure. It involved a determination of the rate of wall thickness loss for these samples. In cases where there was more than one sample of a candidate material in the test section, an assessment was made of the performance of the alloy as a function of temperature. Test Sections B and C were examined during the November 2001 outage, and it was decided that

  5. Magnetic properties of Martian surface material

    NASA Astrophysics Data System (ADS)

    Hargraves, R. B.

    1984-06-01

    The hypothesis that the magnetic properties of the Martian surface material are due to the production of a magnetic phase in the clay mineral nontronite by transient shock heating is examined. In the course of the investigation a magnetic material is produced with rather unusual properties. Heating from 900 C to 1000 C, of natural samples of nontronite leads first to the production of what appears to be Si doped maghemite gamma (-Fe2O3). Although apparently metastable, the growth of gamma -Fe2O3 at these temprtures is unexpected, and its relative persistence of several hours at 1000 C is most surprising. Continued annealing of this material for longer periods promote the crystallization of alpha Fe2O3 and cristobalite (high temperature polymorph of SiO2). All available data correlate this new magnetic material with the cristobalite hence our naming it magnetic ferri cristobalite. Formation of this magnetic cristobalite, however, may require topotactic growth from a smectite precursor.

  6. Magnetic properties of Martian surface material

    NASA Technical Reports Server (NTRS)

    Hargraves, R. B.

    1984-01-01

    The hypothesis that the magnetic properties of the Martian surface material are due to the production of a magnetic phase in the clay mineral nontronite by transient shock heating is examined. In the course of the investigation a magnetic material is produced with rather unusual properties. Heating from 900 C to 1000 C, of natural samples of nontronite leads first to the production of what appears to be Si doped maghemite gamma (-Fe2O3). Although apparently metastable, the growth of gamma -Fe2O3 at these temprtures is unexpected, and its relative persistence of several hours at 1000 C is most surprising. Continued annealing of this material for longer periods promote the crystallization of alpha Fe2O3 and cristobalite (high temperature polymorph of SiO2). All available data correlate this new magnetic material with the cristobalite hence our naming it magnetic ferri cristobalite. Formation of this magnetic cristobalite, however, may require topotactic growth from a smectite precursor.

  7. Fiber twist test: A new test technique to measure composite interface properties

    SciTech Connect

    Chepolis, W.M.; Ertuerk, T.

    1995-10-01

    This paper discusses the work accomplished, thus far, in the development of the Fiber Twist Test (FTT) as an alternative and improved technique for testing the interface properties of continuous fiber composite materials. The unique features of the fiber twist test include the absence of Poisson effects during testing. This eliminates the nonlinear variation, with changing embedded fiber lengths, of fracture modes and accompanying debond energy, and of friction along the interface. Since the fiber is not removed from its surrounding matrix during testing, the interface area remains constant. This facilitates a more accurate measurement of friction properties at the interface.

  8. Neural networks as tools for predicting materials properties

    SciTech Connect

    Sumpter, B.G.; Noid, D.W.

    1995-12-31

    Materials science is of fundamental significance to science and technology because our industrial base and society depend upon our ability to develop advanced materials. Materials and materials processing cuts across almost every sector of industry. The key in all of these areas is the ability to rapidly screen possible designs which will have significant impact. However up to now materials design and processing have been to a large extent empirical sciences. In addition we are still unable to design new alloys and polymers to meet application specific requirements. Being able to do so quickly and at minimum cost would provide an incredible advantage. Obviously, the ability to predict physical, chemical, or mechanical properties of compounds prior to their synthesis is of great technological value in optimizing their design, processing, or recycling. In addition, in order to realize the ultimate goal of materials by computational design, the reverse problem, prediction of chemical structure based on desired properties, has to be resolved. Research at ORNL has lead to the development of a novel computational paradigm (coupling computational neural networks with graph theory, genetic algorithms, wavelet theory, fuzzy logic, molecular dynamics, and quantum chemistry) capable of performing accurate computational synthesis (both predictions of properties or the design of compounds that have specified performance criteria). The computational paradigm represents a hybrid of a number of emerging technologies and has proven to work very well for test compounds ranging from small organic molecules to polymeric materials. Fundamental to the method is the neural network-based formulation of the correlations between structure and properties. The advantages of this method is in its ease of use, speed, accuracy, and that it can be used to predict both properties from structure, and also structure from properties.

  9. Acoustical properties of highly porous fibrous materials

    NASA Technical Reports Server (NTRS)

    Lambert, R. F.

    1979-01-01

    Highly porous, fibrous bulk sound absorbing materials are studied with a view toward understanding their acoustical properties and performance in a wide variety of applications including liners of flow ducts. The basis and criteria for decoupling of acoustic waves in the pores of the frame and compressional waves in the frame structure are established. The equations of motion are recast in a form that elucidates the coupling mechanisms. The normal incidence surface impedance and absorption coefficient of two types of Kevlar 29 and an open celled foam material are studied. Experimental values and theoretical results are brought into agreement when the structure factor is selected to provide a fit to the experimental data. A parametric procedure for achieving that fit is established. Both a bulk material quality factor and a high frequency impedance level are required to characterize the real and imaginary part of the surface impedance and absorption coefficient. A derivation of the concepts of equivalent density and dynamic resistance is presented.

  10. ESP – Data from Restarted Life Tests of Various Silicon Materials

    SciTech Connect

    Schneider, Jim

    2010-10-06

    Current funding has allowed the restart of testing of various silicone materials placed in Life Tests or Aging Studies from past efforts. Some of these materials have been in test since 1982, with no testing for approximately 10 years, until funding allowed the restart in FY97. Charts for the various materials at different thickness, compression, and temperature combinations illustrate trends for the load-bearing properties of the materials.

  11. Optimization of pyrolysis properties using TGA and cone calorimeter test

    NASA Astrophysics Data System (ADS)

    Park, Won-Hee; Yoon, Kyung-Beom

    2013-04-01

    The present paper describes an optimization work to obtain the properties related to a pyrolysis process in the solid material such as density, specific heat, conductivity of virgin and char, heat of pyrolysis and kinetic parameters used for deciding pyrolysis rate. A repulsive particle swarm optimization algorithm is used to obtain the pyrolysis-related properties. In the previous study all properties obtained only using a cone calorimeter but in this paper both the cone calorimeter and thermo gravimetric analysis (TGA) are used for precisely optimizing the pyrolysis properties. In the TGA test a very small mass is heated up and conduction and heat capacity in the specimen is negligible so kinetic parameters can first be optimized. Other pyrolysis-related properties such as virgin/char specific heat and conductivity and char density are also optimized in the cone calorimeter test with the already decided parameters in the TGA test.

  12. Ground Deployment Demonstration and Material Testing for Solar Sail

    NASA Astrophysics Data System (ADS)

    Huang, Xiaoqi; Cheng, Zhengai; Liu, Yufei; Wang, Li

    2016-07-01

    Solar Sail is a kind of spacecraft that can achieve extremely high velocity by light pressure instead of chemical fuel. The great accelerate rely on its high area-to-mass ratio. So solar sail is always designed in huge size and it use ultra thin and light weight materials. For 100-meter class solar sail, two key points must be considered in the design process. They are fold-deployment method, and material property change in space environment. To test and verify the fold-deployment technology, a 8*8m principle prototype was developed. Sail membrane folding in method of IKAROS, Nanosail-D , and new proposed L-shape folding pattern were tested on this prototype. Their deployment properties were investigated in detail, and comparisons were made between them. Also, the space environment suitability of ultra thin polyimide films as candidate solar sail material was analyzed. The preliminary test results showed that membrane by all the folding method could deploy well. Moreover, sail membrane folding by L-shape pattern deployed more rapidly and more organized among the three folding pattern tested. The mechanical properties of the polyimide had no significant change after electron irradiation. As the preliminary research on the key technology of solar sail spacecraft, in this paper, the results of the study would provide important basis on large-scale solar sail membrane select and fold-deploying method design.

  13. Magnetic properties of frictional volcanic materials

    NASA Astrophysics Data System (ADS)

    Kendrick, Jackie E.; Lavallée, Yan; Biggin, Andrew; Ferk, Annika; Leonhardt, Roman

    2015-04-01

    During dome-building volcanic eruptions, highly viscous magma extends through the upper conduit in a solid-like state. The outer margins of the magma column accommodate the majority of the strain, while the bulk of the magma is able to extrude, largely undeformed, to produce magma spines. Spine extrusion is often characterised by the emission of repetitive seismicity, produced in the upper <1 km by magma failure and slip at the conduit margins. The rheology of the magma controls the depth at which fracture can occur, while the frictional properties of the magma are important in controlling subsequent marginal slip processes. Upon extrusion, spines are coated by a carapace of volcanic fault rocks which provide insights into the deeper conduit processes. Frictional samples from magma spines at Mount St. Helens (USA), Soufriere Hills (Montserrat) and Mount Unzen (Japan) have been examined using structural, thermal and magnetic analyses to reveal a history of comminution, frictional heating, melting and cooling to form volcanic pseudotachylyte. Pseudotachylyte has rarely been noted in volcanic materials, and the recent observation of its syn-eruptive formation in dome-building volcanoes was unprecedented. The uniquely high thermal conditions of volcanic environments means that frictional melt remains at elevated temperatures for longer than usual, causing slow crystallisation, preventing the development of some signature "quench" characteristics. As such, rock-magnetic tests have proven to be some of the most useful tools in distinguishing pseudotachylytes from their andesite/ dacite hosts. In volcanic pseudotachylyte the mass normalised natural remanent magnetisation (NRM) when further normalised with the concentration dependent saturation remanence (Mrs) was found to be higher than the host rock. Remanence carriers are defined as low coercive materials across all samples, and while the remanence of the host rock displays similarities to an anhysteretic remanent

  14. Arc jet tests of metallic TPS materials.

    NASA Technical Reports Server (NTRS)

    Centolanzi, F. J.; Zimmerman, N. B.; Probst, H. B.; Lowell, C. E.

    1971-01-01

    Seven thoria dispersed nickel base alloys and one cobalt base alloy, candidates for the Metallic Thermal Protection System for the Space Shuttle Vehicle, were tested simultaneously in an arc jet at a nominal test temperature of 1366 deg K (2000 deg F) and pressure of 0.01 atmospheres. The degradation of the materials after 50 one half-hour cycles in the arc jet simulating Space Shuttle entry conditions was determined utilizing techniques including X-ray diffraction, metallography, and electron beam microprobe.

  15. Mechanical properties testing and results for thermal barrier coatings

    NASA Astrophysics Data System (ADS)

    Cruse, T. A.; Johnsen, B. P.; Nagy, A.

    1997-03-01

    Mechanical test data for thermal barrier coatings, including modulus, static strength, and fatigue strength data, are reviewed in support of the development of durability models for heat engine applica-tions. The materials include 7 and 8 wt % yttria partially stabilized zirconia (PSZ) as well as a cermet ma-terial (PSZ +10 wt % NiCoCrAlY). Both air plasma sprayed and electron beam physical vapor deposited coatings were tested. The data indicate the basic trends in the mechanical properties of the coatings over a wide range of isothermal conditions. Some of the trends are correlated with material density.

  16. Comparative study of the physical properties of core materials.

    PubMed

    Saygili, Gülbin; Mahmali, Sevil M

    2002-08-01

    This study was undertaken to measure physical properties of materials used for direct core buildups, including high-copper amalgam, visible light-cured resin composite, autocured titanium-containing composite, polyacid-modified composite, resin-modified glass-ionomer, and silver cermet cement. Compressive strength, diametral tensile strength, and flexural strength of six core materials of various material classes were measured for each material as a function of time up to 3 months at different storage conditions, using a standard specification test designed for the materials. Three different storage conditions (dry, humid, wet) at 37 degrees C were chosen. Materials were manipulated according to manufacturers' instructions for use as cores. Mean compressive, diametral tensile, and flexural strengths with associated standard deviations were calculated for each material. Multiple comparison and Newman-Keuls tests discerned many differences among materials. All materials were found to meet the minimum specification requirements, except in terms of flexural strength for amalgam after 1 hour and the silver cermet at all time intervals. PMID:12212682

  17. Apparatus Tests Peeling Of Bonded Rubbery Material

    NASA Technical Reports Server (NTRS)

    Crook, Russell A.; Graham, Robert

    1996-01-01

    Instrumented hydraulic constrained blister-peel apparatus obtains data on degree of bonding between specimen of rubbery material and rigid plate. Growth of blister tracked by video camera, digital clock, pressure transducer, and piston-displacement sensor. Cylinder pressure controlled by hydraulic actuator system. Linear variable-differential transformer (LVDT) and float provide second, independent measure of change in blister volume used as more precise volume feedback in low-growth-rate test.

  18. Test System for Thermoelectric Modules and Materials

    NASA Astrophysics Data System (ADS)

    Hejtmánek, J.; Knížek, K.; Švejda, V.; Horna, P.; Sikora, M.

    2014-10-01

    We present a design for a complex measuring device that enables its user to assess the parameters of power-generating thermoelectric modules (TEMs) (or bulk thermoelectric materials) under a wide range of temperatures ( T cold = 25°C to 90°C, T hot < 450°C) and mechanical loading ( P = 0 N to 104 N). The proposed instrument is able to monitor the temperature and electrical output of the TEM, the actual heat flow through the module, and its mechanical load, which can be varied during the measurement. Key components of our testing setup are (i) a measuring chamber where the TEM/material is compressed between thermally shielded heating blocks equipped with a mechanical loading system and water-cooled copper-based cooler, (ii) an electrical load system, (iii) a type K thermocouple array connected to a data acquisition computer, and (iv) a thermostatic water-based cooling system with electronically controlled flow rate and temperature of cooling water. Our testing setup represents a useful tool able to assess, e.g., the thermoelectric parameters of newly developed TEMs and materials or to evaluate the thermoelectric parameters of commercially available modules and materials for comparison with values declared by the manufacturer.

  19. Irradiation Environment of the Materials Test Station

    SciTech Connect

    Pitcher, Eric John

    2012-06-21

    Conceptual design of the proposed Materials Test Station (MTS) at the Los Alamos Neutron Science Center (LANSCE) is now complete. The principal mission is the irradiation testing of advanced fuels and materials for fast-spectrum nuclear reactor applications. The neutron spectrum in the fuel irradiation region of MTS is sufficiently close to that of fast reactor that MTS can match the fast reactor fuel centerline temperature and temperature profile across a fuel pellet. This is an important characteristic since temperature and temperature gradients drive many phenomena related to fuel performance, such as phase stability, stoichiometry, and fission product transport. The MTS irradiation environment is also suitable in many respects for fusion materials testing. In particular, the rate of helium production relative to atomic displacements at the peak flux position in MTS matches well that of fusion reactor first wall. Nuclear transmutation of the elemental composition of the fusion alloy EUROFER97 in MTS is similar to that expected in the first wall of a fusion reactor.

  20. Mechanics of Granular Materials (MGM) Test Cell

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A test cell for Mechanics of Granular Materials (MGM) experiment is tested for long-term storage with water in the system as plarned for STS-107. This view shows the compressed sand column with the protective water jacket removed. Sand and soil grains have faces that can cause friction as they roll and slide against each other, or even cause sticking and form small voids between grains. This complex behavior can cause soil to behave like a liquid under certain conditions such as earthquakes or when powders are handled in industrial processes. Mechanics of Granular Materials (MGM) experiments aboard the Space Shuttle use the microgravity of space to simulate this behavior under conditons that cannot be achieved in laboratory tests on Earth. MGM is shedding light on the behavior of fine-grain materials under low effective stresses. Applications include earthquake engineering, granular flow technologies (such as powder feed systems for pharmaceuticals and fertilizers), and terrestrial and planetary geology. Nine MGM specimens have flown on two Space Shuttle flights. Another three are scheduled to fly on STS-107. The principal investigator is Stein Sture of the University of Colorado at Boulder. Credit: University of Colorado at Boulder

  1. Mechanics of Granular Materials (MGM) Test Cell

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A test cell for Mechanics of Granular Materials (MGM) experiment is tested for long-term storage with water in the system as plarned for STS-107. This view shows the top of the sand column with the metal platten removed. Sand and soil grains have faces that can cause friction as they roll and slide against each other, or even cause sticking and form small voids between grains. This complex behavior can cause soil to behave like a liquid under certain conditions such as earthquakes or when powders are handled in industrial processes. Mechanics of Granular Materials (MGM) experiments aboard the Space Shuttle use the microgravity of space to simulate this behavior under conditons that cannot be achieved in laboratory tests on Earth. MGM is shedding light on the behavior of fine-grain materials under low effective stresses. Applications include earthquake engineering, granular flow technologies (such as powder feed systems for pharmaceuticals and fertilizers), and terrestrial and planetary geology. Nine MGM specimens have flown on two Space Shuttle flights. Another three are scheduled to fly on STS-107. The principal investigator is Stein Sture of the University of Colorado at Boulder. Credit: University of Colorado at Boulder

  2. The role of material properties in adhesion

    NASA Technical Reports Server (NTRS)

    Buckley, D. H.

    1984-01-01

    When two solid surfaces are brought into contact strong adhesive bond forces can develop between the materials. The magnitude of the forces will depend upon the state of the surfaces, cleanliness and the fundamental properties of the two solids, both surface and bulk. Adhesion between solids is addressed from a theoretical consideration of the electronic nature of the surfaces and experimentally relating bond forces to the nature of the interface resulting from solid state contact. Surface properties correlated with adhesion include, atomic or molecular orientation, reconstruction and segregation as well as the chemistry of the surface specie. Where dissimilar solids are in contact the contribution of each is considered as is the role of their interactive chemistry on bond strength. Bulk properties examined include elastic and plastic behavior in the surficial regions, cohesive binding energies, crystal structure, crystallographic orientation and state. Materials examined with respect to interfacial adhesive interactions include metals, alloys, ceramics, polymers and diamond. They are reviewed both in single and polycrystalline form. The surfaces of the contacting solids are studied both in the atomic or molecularly clean state and in the presence of selected surface contaminants.

  3. Can the material properties of regenerate bone be predicted with non-invasive methods of assessment? Exploring the correlation between dual X-ray absorptiometry and compression testing to failure in an animal model of distraction osteogenesis.

    PubMed

    Monsell, Fergal; Hughes, Andrew William; Turner, James; Bellemore, Michael C; Bilston, Lynne

    2014-04-01

    Evaluation of the material properties of regenerate bone is of fundamental importance to a successful outcome following distraction osteogenesis using an external fixator. Plain radiographs are in widespread use for assessment of alignment and the distraction gap but are unable to detect bone formation in the early stages of distraction osteogenesis and do not quantify accurately the structural properties of the regenerate. Dual X-ray absorptiometry (DXA) is a widely available non-invasive imaging modality that, unlike X-ray, can be used to measure bone mineral content (BMC) and density quantitatively. In order to be useful as a clinical investigation; however, the structural two-dimensional geometry and density distributions assessed by DXA should reflect material properties such as modulus and also predict the structural mechanical properties of the regenerate bone formed. We explored the hypothesis that there is a relationship between DXA assessment of regenerate bone and structural mechanical properties in an animal model of distraction osteogenesis. Distraction osteogenesis was carried out on the tibial diaphysis of 41 male, 12 week old, New Zealand white rabbits as part of a larger study. Distraction started after a latent period of 24 h at a rate of 0.375 mm every 12 h and continued for 10-days, achieving average lengthening of 7.1 mm. Following an 18-day period of consolidation, the regenerate bone was subject to bone density measurements using a total body dual-energy X-ray densitometer. This produced measurement of BMC, bone mineral density (BMD) and volumetric bone mineral density (vBMD). The tibiae were then disarticulated and cleaned of soft tissue before loading in compression to failure using an Instron mechanical testing machine (Instron Corporation, Massachusetts USA). Using Spearman rank correlation and linear regression, there was a significant correlation between vBMD and the Modulus of Elasticity, Yield Stress and Failure Stress of the

  4. Physical Properties of Thin Film Semiconducting Materials

    NASA Astrophysics Data System (ADS)

    Bouras, N.; Djebbouri, M.; Outemzabet, R.; Sali, S.; Zerrouki, H.; Zouaoui, A.; Kesri, N.

    2005-10-01

    The physics and chemistry of semiconducting materials is a continuous question of debate. We can find a large stock of well-known properties but at the same time, many things are not understood. In recent years, porous silicon (PS-Si), diselenide of copper and indium (CuInSe2 or CIS) and metal oxide semiconductors like tin oxide (SnO2) and zinc oxide (ZnO) have been subjected to extensive studies because of the rising interest their potential applications in fields such as electronic components, solar panels, catalysis, gas sensors, in biocompatible materials, in Li-based batteries, in new generation of MOSFETS. Bulk structure and surface and interface properties play important roles in all of these applications. A deeper understanding of these fundamental properties would impact largely on technological application performances. In our laboratory, thin films of undoped and antimony-doped films of tin oxide have been deposited by chemical vapor deposition. Spray pyrolysis was used for ZnO. CIS was prepared by flash evaporation or close-space vapor transport. Some of the deposition parameters have been varied, such as substrate temperature, time of deposition (or anodization), and molar concentration of bath preparation. For some samples, thermal annealing was carried out under oxygen (or air), under nitrogen gas and under vacuum. Deposition and post-deposition parameters are known to strongly influence film structure and electrical resistivity. We investigated the influence of film thickness and thermal annealing on structural optical and electrical properties of the films. Examination of SnO2 by x-ray diffraction showed that the main films are polycrystalline with rutile structure. The x-ray spectra of ZnO indicated a hexagonal wurtzite structure. Characterizations of CIS films with compositional analysis, x-ray diffraction, scanning microscopy, spectrophotometry, and photoluminescence were carried out.

  5. New Monolayered Materials Exhibiting Unusual Electronic Properties

    NASA Astrophysics Data System (ADS)

    Lopez-Bezanilla, Alejandro; Martin, Ivar; Littlewood, Peter B.

    Computationally based approaches are allowing to progress in the discovery and design of nano-scaled materials. Here we propose a series of new mono-layered compounds with exotic properties. By means of density functional theory calculations we demonstrate that the pentagonal arrangement of SiC2 yields an inverted distribution of the p-bands which leads to an unusual electronic behaviour of the material under strain [J. Phys. Chem. C, 2015, 119 (33), pp 19469]. A different pentagonal arrangement of C atoms enables the formation of Dirac cones which, unlike graphene, exhibit a strain-mediated tunable band gap. This work is supported by DOE-BES under Contract No. DE-AC02-06CH11357.

  6. Millimeter wave and terahertz dielectric properties of biological materials

    NASA Astrophysics Data System (ADS)

    Khan, Usman Ansar

    Broadband dielectric properties of materials can be employed to identify, detect, and characterize materials through their unique spectral signatures. In this study, millimeter wave, submillimeter wave, and terahertz dielectric properties of biological substances inclusive of liquids, solids, and powders were obtained using Dispersive Fourier Transform Spectroscopy (DFTS). Two broadband polarizing interferometers were constructed to test materials from 60 GHz to 1.2 THz. This is an extremely difficult portion of the frequency spectrum to obtain a material's dielectric properties since neither optical nor microwave-based techniques provide accurate data. The dielectric characteristics of liquids such as cyclohexane, chlorobenzene, benzene, ethanol, methanol, 1,4 dioxane, and 10% formalin were obtained using the liquid interferometer. Subsequently the solid interferometer was utilized to determine the dielectric properties of human breast tissues, which are fixed and preserved in 10% formalin. This joint collaboration with the Tufts New England Medical Center demonstrated a significant difference between the dielectric response of tumorous and non-tumorous breast tissues across the spectrum. Powders such as anthrax, flour, talc, corn starch, dry milk, and baking soda have been involved in a number of security threats and false alarms around the globe in the last decade. To be able to differentiate hoax attacks and serious security threats, the dielectric properties of common household powders were also examined using the solid interferometer to identify the powders' unique resonance peaks. A new sample preparation kit was designed to test the powder specimens. It was anticipated that millimeter wave and terahertz dielectric characterization will enable one to clearly distinguish one powder from the other; however most of the powders had relatively close dielectric responses and only Talc had a resonance signature recorded at 1.135 THz. Furthermore, due to

  7. Clinical Biospecimens: Reference Materials, Certified for Nominal Properties?

    PubMed Central

    2014-01-01

    This report makes the case for clinical biospecimens to be certified for nominal properties, in particular the diagnosis, and to attain the level of Reference Materials. Clinical certified biospecimens that are collected, processed, characterized, stored, and distributed by biobanks are urgently needed to facilitate diagnostic test development, evaluation, and quality assurance. Four examples are provided to illustrate this purpose and the certification approaches that could be applied are proposed. PMID:24749878

  8. Orbit transfer rocket engine technology program: Oxygen materials compatibility testing

    NASA Technical Reports Server (NTRS)

    Schoenman, Leonard

    1989-01-01

    Particle impact and frictional heating tests of metals in high pressure oxygen, are conducted in support of the design of an advanced rocket engine oxygen turbopump. Materials having a wide range of thermodynamic properties including heat of combustion and thermal diffusivity were compared in their resistance to ignition and sustained burning. Copper, nickel and their alloys were found superior to iron based and stainless steel alloys. Some materials became more difficult to ignite as oxygen pressure was increased from 7 to 21 MPa (1000 to 3000 psia).

  9. Molybdenum silicide based materials and their properties

    SciTech Connect

    Yao, Z.; Stiglich, J.; Sudarshan, T.S.

    1999-06-01

    Molybdenum disilicide (MoSi{sub 2}) is a promising candidate material for high temperature structural applications. It is a high melting point (2030 C) material with excellent oxidation resistance and a moderate density (6.24 g/cm{sup 3}). However, low toughness at low temperatures and high creep rates at elevated temperatures have hindered its commercialization in structural applications. Much effort has been invested in MoSi{sub 2} composites as alternatives to pure molybdenum disilicide for oxidizing and aggressive environments. Molybdenum disilicide-based heating elements have been used extensively in high-temperature furnaces. The low electrical resistance of silicides in combination with high thermal stability, electron-migration resistance, and excellent diffusion-barrier characteristics is important for microelectronic applications. Projected applications of MoSi{sub 2}-based materials include turbine airfoils, combustion chamber components in oxidizing environments, missile nozzles, molten metal lances, industrial gas burners, diesel engine glow plugs, and materials for glass processing. On this paper, synthesis, fabrication, and properties of the monolithic and composite molybdenum silicides are reviewed.

  10. Material Properties Analysis of Structural Members in Pumpkin Balloons

    NASA Technical Reports Server (NTRS)

    Sterling, W. J.

    2003-01-01

    The efficient design, service-life qualification, and reliability predictions for lightweight aerospace structures require careful mechanical properties analysis of candidate structural materials. The demand for high-quality laboratory data is particularly acute when the candidate material or the structural design has little history. The pumpkin-shaped super-pressure balloon presents both challenges. Its design utilizes load members (tendons) extending from apex to base around the gas envelope to achieve a lightweight structure. The candidate tendon material is highly weight-efficient braided HM cord. Previous mechanical properties studies of Zylon have focused on fiber and yarn, and industrial use of the material in tensile applications is limited. For high-performance polymers, a carefully plamed and executed properties analysis scheme is required to ensure the data are relevant to the desired application. Because no directly-applicable testing standard was available, a protocol was developed based on guidelines fiom professional and industry organizations. Due to the liquid-crystalline nature of the polymer, the cord is very stiff, creeps very little, and does not yield. Therefore, the key material property for this application is the breaking strength. The pretension load and gauge length were found to have negligible effect on the measured breaking strength over the ranges investigated. Strain rate was found to have no effect on breaking strength, within the range of rates suggested by the standards organizations. However, at the lower rate more similar to ULDB operations, the strength was reduced. The breaking strength increased when the experiment temperature was decreased from ambient to 183K which is the lowest temperature ULDB is expected to experience. The measured strength under all test conditions was well below that resulting from direct scale-up of fiber strength based on the manufacturers data. This expected result is due to the effects of the