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Sample records for material properties experiments

  1. Hydrodynamics and Material Properties Experiments Using Pulsed Power Techniques*

    NASA Astrophysics Data System (ADS)

    Reinovsky, Robert; Trainor, R. James

    1999-06-01

    Within the last few years a new approach for exploring dynamic material properties and advanced hydrodynamics at extreme conditions has joined the traditional techniques of high velocity guns,and explosives. The principle tool is the high precision, magnetically imploded, near-solid density liner. The most attractive pulse power system for driving such experiments is an ultra-highcurrent, low impedance, microsecond time-scale source that is economical both the build and operate. Liner specifications vary but in general share requirements for a high degree of symmetry and uniformity after implosion. When imploded in free flight to velocities 10-30 km/sec and kinetic energies of from one to 25 MJ/cm of height, liners are attractive impactors for producing strong (>10 Mbar) shocks in the target. Simple geometries can, in principle, produce multi-shock environments to reach off-hugoniot states. When filled with a compressible material, liners can deliver almost adiabatic compression to the target. When the liner surrounds a (small)nearly incompressible target material, for example a condensed noble gas, a liner can deliver enormous pressure to the target almost isentropically. When the compressible material is a magnetic field, flux compression can results in compressed fields above 1000 tesla in macroscopic volumes for materials studies.In this paper we will review basic scaling argumentsthat set the scale of environments available. We will mention the pulse power technology under development at Los Alamos and provide a summary of results from experiments testing solid metal liners under magnetic drive and a few examples of experiments performed withinterim systems. Other papers in this conference will provide specific proposals for pulse power driven shock-wave experiments.

  2. Simple Experiment for Studying the Properties of a Ferromagnetic Material.

    ERIC Educational Resources Information Center

    Sood, B. R.; And Others

    1980-01-01

    Describes an undergraduate physics experiment for studying Curie temperature and Curie constant of a ferromagnetic material. The exchange field (Weiss field) has been estimated by using these parameters. (HM)

  3. GIGABAR MATERIAL PROPERTIES EXPERIMENTS ON NIF AND OMEGA

    SciTech Connect

    Swift, D C; Hawreliak, J A; Braun, D; Kritcher, A; Glenzer, S; Collins, G W; Rothman, S D; Chapman, D; Rose, S

    2011-08-04

    The unprecedented laser capabilities of the National Ignition Facility (NIF) make it possible for the first time to countenance laboratory-scale experiments in which gigabar pressures can be applied to a reasonable volume of material, and sustained long enough for percent level equation of state measurements to be made. We describe the design for planned experiments at the NIF, using a hohlraum drive to induce a spherically-converging shock in samples of different materials. Convergence effects increase the shock pressure to several gigabars over a radius of over 100 microns. The shock speed and compression will be measured radiographically over a range of pressures using an x-ray streak camera. In some cases, we will use doped layers to allow a radiographic measurement of particle velocity.

  4. 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).

  5. Review of world experience and properties of materials for encapsulation of terrestrial photovoltaic arrays

    NASA Technical Reports Server (NTRS)

    Carmichael, D. C.; Gaines, G. B.; Sliemers, F. A.; Kistler, C. W.; Igou, R. D.

    1976-01-01

    Published and unpublished information relating to encapsulation systems and materials properties was collected by searching the literature and appropriate data bases (over 1,300 documents were selected and reviewed) and by personal contacts including site and company visits. A data tabulation summarizing world experience with terrestrial photovoltaic arrays (50 installations) is presented in the report. Based on criteria of properties, processability, availability, and cost, candidate materials were identified which have potential for use in encapsulation systems for arrays with a lifetime of over 20 years high reliability, an efficiency greater than 10 percent, a total price less than $500/kW, and a production capacity of 500,000 kW/yr. The recommended materials (all commercially available) include, depending upon the device design, various borosilicate and soda-lime glasses and numerous polymerics suitable for specific encapsulation system functions.

  6. Surface electrical properties experiment

    USGS Publications Warehouse

    Simmons, Gene; Strangway, David; Annan, Peter; Baker, Richard G.; Bannister, Lawrence; Brown, Raymon; Cooper, William; Cubley, Dean; deBettencourt, Joseph; England, Anthony W.; Groener, John; Kong, Jin-Au; LaTorraca, Gerald; Meyer, James; Nanda, Ved; Redman, David; Rossiter, James; Tsang, Leung; Urner, Joseph; Watts, Raymond

    1973-01-01

    The surface electrical properties (SEP) experiment was used to explore the subsurface material of the Apollo 17 landing site by means of electromagnetic radiation. The experiment was designed to detect electrical layering, discrete scattering bodies, and the possible presence of water. From the analysis of the data, it was expected that values of the electrical properties (dielectric constant and loss tangent) of lunar material in situ would be obtained.

  7. Using Design of Experiments Methods for Assessing Peak Contact Pressure to Material Properties of Soft Tissue in Human Knee

    PubMed Central

    Jahan, Ali; Arumugam, Manohar; Hassan, Mohd Roshdi

    2013-01-01

    Contact pressure in the knee joint is a key element in the mechanisms of knee pain and osteoarthritis. Assessing the contact pressure in tibiofemoral joint is a challenging mechanical problem due to uncertainty in material properties. In this study, a sensitivity analysis of tibiofemoral peak contact pressure to the material properties of the soft tissue was carried out through fractional factorial and Box-Behnken designs. The cartilage was modeled as linear elastic material, and in addition to its elastic modulus, interaction effects of soft tissue material properties were added compared to previous research. The results indicated that elastic modulus of the cartilage is the most effective factor. Interaction effects of axial/radial modulus with elastic modulus of cartilage, circumferential and axial/radial moduli of meniscus were other influential factors. Furthermore this study showed how design of experiment methods can help designers to reduce the number of finite element analyses and to better interpret the results. PMID:27006925

  8. Scaling of material properties for Yucca Mountain: literature review and numerical experiments on saturated hydraulic conductivity

    SciTech Connect

    McKenna, S.A.; Rautman, C.A.

    1996-08-01

    A review of pertinent literature reveals techniques which may be practical for upscaling saturated hydraulic conductivity at Yucca Mountain: geometric mean, spatial averaging, inverse numerical modeling, renormalization, and a perturbation technique. Isotropic realizations of log hydraulic conductivity exhibiting various spatial correlation lengths are scaled from the point values to five discrete scales through these techniques. For the variances in log{sub 10} saturated hydraulic conductivity examined here, geometric mean, numerical inverse and renormalization adequately reproduce point scale fluxes across the modeled domains. Fastest particle velocities and dispersion measured on the point scale are not reproduced by the upscaled fields. Additional numerical experiments examine the utility of power law averaging on a geostatistical realization of a cross-section similar to the cross-sections that will be used in the 1995 groundwater travel time calculations. A literature review on scaling techniques for thermal and mechanical properties is included. 153 refs., 29 figs., 6 tabs.

  9. Microstructure and Property Evolution in Advanced Cladding and Duct Materials Under Long-Term Irradiation at Elevated Temperature: Critical Experiments

    SciTech Connect

    Was, Gary; Jiao, Zhijie; Allen, Todd; Yang, Yong

    2013-12-20

    The in-service degradation of reactor core materials is related to underlying changes in the irradiated microstructure. During reactor operation, structural components and cladding experience displacement of atoms by collisions with neutrons at temperatures at which the radiation-induced defects are mobile, leading to microstructure evolution under irradiation that can degrade material properties. At the doses and temperatures relevant to fast reactor operation, the microstructure evolves by microchemistry changes due to radiation-induced segregation, dislocation loop formation and growth, radiation induced precipitation, destabilization of the existing precipitate structure, as well as the possibility for void formation and growth. These processes do not occur independently; rather, their evolution is highly interlinked. Radiation-induced segregation of Cr and existing chromium carbide coverage in irradiated alloy T91 track each other closely. The radiation-induced precipitation of Ni-Si precipitates and RIS of Ni and Si in alloys T91 and HCM12A are likely related. Neither the evolution of these processes nor their coupling is understood under the conditions required for materials performance in fast reactors (temperature range 300-600°C and doses to 200 dpa and beyond). Further, predictive modeling is not yet possible, as models for microstructure evolution must be developed along with experiments to characterize these key processes and provide tools for extrapolation. To extend the range of operation of nuclear fuel cladding and structural materials in advanced nuclear energy and transmutation systems to that required for the fast reactor, the irradiation-induced evolution of the microstructure, microchemistry, and the associated mechanical properties at relevant temperatures and doses must be understood. This project builds upon joint work at the proposing institutions, under a NERI-C program that is scheduled to end in September, to understand the effects of

  10. 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.

  11. 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.

  12. Plastic Recycling Experiments in Materials Education

    NASA Technical Reports Server (NTRS)

    Liu, Ping; Waskom, Tommy L.

    1996-01-01

    The objective of this project was to introduce a series of plastic recycling experiments to students in materials-related courses such as materials science, material technology and materials testing. With the plastic recycling experiments, students not only can learn the fundamentals of plastic processing and properties as in conventional materials courses, but also can be exposed to the issue of materials life cycle and the impact on society and environment.

  13. Materials Adherence Experiment: Technology

    SciTech Connect

    Jenkins, P.P.; Landis, G.A.; Oberle, L.G.

    1997-12-31

    NASA`s Mars Pathfinder mission, launched December 4, 1996, reflects a new philosophy of exploiting new technologies to reduce mission cost and accelerate the pace of space exploration. Pathfinder will demonstrate a variety of new technologies aimed at reducing the cost of Mars exploration. Chief among these will be the demonstration of a solar-powered spacecraft on the surface of Mars. The Materials Adherence Experiment on Pathfinder was designed to measure the degradation of solar arrays due to dust settling out of the atmosphere and blocking light to the solar array, lowering the array power output.

  14. Using split-ring resonators to measure the electromagnetic properties of materials: An experiment for senior physics undergraduates

    NASA Astrophysics Data System (ADS)

    Bobowski, J. S.

    2013-12-01

    A spilt-ring resonator experiment suitable for senior physics undergraduates is described and demonstrated in detail. The apparatus consists of a conducting hollow cylinder with a narrow slit along its length and can be accurately modelled as a series LRC circuit. The resonance frequency and quality factor of the split-ring resonator are measured when the apparatus is suspended in air, submerged in water, and submerged in an aqueous solution of various concentrations of NaCl. The experimental results are used to extract the dielectric constant of water and to investigate the dependence of the resonator quality factor on the conductivity of the NaCl solution. The apparatus provides opportunities to experimentally examine radiative losses, complex permittivity, the electromagnetic skin depth, and cutoff frequencies of rf propagation in cylindrical waveguides, which are all concepts introduced in an undergraduate course in electrodynamics. To connect with current research, the use of split-ring resonators as a tool to precisely measure the electromagnetic properties of materials is emphasized.

  15. Material science experiments on the Atlas Facility

    SciTech Connect

    Keinigs, R. K.; Atchison, W. L.; Faehl, R. J.; Lindemuth, I. R.; Anderson, W. E.; Bartsch, R. R.; Flower-Maudlin, E. C.; Hammerberg, J. E.; Holtkamp, D. B.; Jones, M. E.; Kyrala, George A.; Oro, D. M.; Parker, J. V.; Preston, D. L.; Reinovsky, R. E.; Scudder, D. W.; Sheehey, P. T.; Shlacter, J. S.; Stokes, J. L.; Taylor, Antoinette J.,; Tonks, D. L.; Turchi, Peter J.

    2001-01-01

    Three material properties experiments that are to be performed on the Atlas pulsed power facility are described; friction at sliding metal interfaces, spallation and damage in convergent geomety, and plastic flow at high strain and high strain rate. Construction of this facility has been completed and experiments in high energy density hydrodynamics and material dynamics will begin in 2001.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. Element material experiment by EFFU

    NASA Technical Reports Server (NTRS)

    Hashimoto, Yoshihiro; Ichikawa, Masaaki; Takei, Mitsuru; Torii, Yoshihiro; Ota, Kazuo

    1995-01-01

    National Space Development Agency of JAPAN (NASDA) is planning to perform Element Material Exposure Experiment using Exposed Facility Flyer Unit (EFFU). Several materials which will be used on JEM (Japanese Experiment Module for the space station) will be exposed. Space environment monitoring is also planned in this experiment. Several ground based tests are now being performed and getting useful data.

  1. Preliminary experiments about the measure of the magnetic properties of a material by means of TDR probes

    NASA Astrophysics Data System (ADS)

    Persico, Raffaele

    2016-04-01

    In this contribution, the possibility of measuring possible magnetic properties of materials by means of a TDR probe is studied. A transmission line model is adopted and data in time and frequency domain are exploited together. Simulation results are shown, at the moment based on a bifilar line model. Magnetic properties of materials can be of interest for several applications. In particular, the presence of magnetic features in the soil or in any substance, might be associated to some contaminant (presumably containing some metallic element as iron, nickel or chromium [1]). This kind of pollution might occur close to some farms, especially regarding the dying of dresses, the production of some medicines, the tanning of leather issues. Moreover, modern agriculture puts in the soil several fertilizing substances, and there is a debate about the quantity of heavy metals spread in the terrain by these activities [2]. Still, some depuration-mud can be affected by an excessive presence of metallic elements, because of the presence of batteries, skins, varnishes, cosmetics, and so on [2]. Moreover, it is thought that the soil on the planet Mars might show magnetic properties [3]. Finally, in GPR prospecting, possible magnetic characteristics of the soil or of the targets might be of interest too [4], but they cannot be retrieved by means of only GPR data [5]. In the present paper, the results of a preliminary study are exposed with regard to the possibility to measure the magnetic properties of a material by mean of a TDR probe [6-7]. In particular a TDR probe is essentially a transmission line (a bifilar model will be exploited in this work) open at the end, form which most of the impinging energy (ideally the whole of thi energy in a lossless medium) is back reflected. In particular, this allows a customary measure of the propagation velocity in the medium if an impulsive signal is generated. In fact, the return time along a path of known length is measured. The

  2. Preliminary experiments about the measure of the magnetic properties of a material by means of TDR probes

    NASA Astrophysics Data System (ADS)

    Persico, Raffaele

    2016-04-01

    In this contribution, the possibility of measuring possible magnetic properties of materials by means of a TDR probe is studied. A transmission line model is adopted and data in time and frequency domain are exploited together. Simulation results are shown, at the moment based on a bifilar line model. Magnetic properties of materials can be of interest for several applications. In particular, the presence of magnetic features in the soil or in any substance, might be associated to some contaminant (presumably containing some metallic element as iron, nickel or chromium [1]). This kind of pollution might occur close to some farms, especially regarding the dying of dresses, the production of some medicines, the tanning of leather issues. Moreover, modern agriculture puts in the soil several fertilizing substances, and there is a debate about the quantity of heavy metals spread in the terrain by these activities [2]. Still, some depuration-mud can be affected by an excessive presence of metallic elements, because of the presence of batteries, skins, varnishes, cosmetics, and so on [2]. Moreover, it is thought that the soil on the planet Mars might show magnetic properties [3]. Finally, in GPR prospecting, possible magnetic characteristics of the soil or of the targets might be of interest too [4], but they cannot be retrieved by means of only GPR data [5]. In the present paper, the results of a preliminary study are exposed with regard to the possibility to measure the magnetic properties of a material by mean of a TDR probe [6-7]. In particular a TDR probe is essentially a transmission line (a bifilar model will be exploited in this work) open at the end, form which most of the impinging energy (ideally the whole of thi energy in a lossless medium) is back reflected. In particular, this allows a customary measure of the propagation velocity in the medium if an impulsive signal is generated. In fact, the return time along a path of known length is measured. The

  3. 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.

  4. 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.

  5. Property changes induced by the space environment in composite materials on LDEF: Solar array materials passive LDEF experiment A0171 (SAMPLE)

    NASA Technical Reports Server (NTRS)

    1993-01-01

    Surface modifications to composite materials induced by long term exposure in low earth orbit (LEO) were dominated by atomic oxygen erosion and micrometeoroid and space debris impacts. As expected, calculated erosion rates were peculiar to material type and within the predicted order of magnitude. Generally, about one ply of the carbon fiber composites was eroded during the 70 month LDEF experiment. Matrix erosion was greater than fiber erosion and was more evident for a polysulfone matrix than for epoxy matrices. Micrometeoroid and space debris impacts resulted in small (less than 1mm) craters and splattered contaminants on all samples. Surfaces became more diffuse and darker with small increases in emissivity and absorption. Tensile strength decreased roughly with thickness loss, and epoxy matrices apparently became slightly embrittled, probably as a result of continued curing under UV and/or electron bombardment. However, changes in the ultimate yield stress of the carbon reinforced epoxy composites correlate neither with weave direction nor fiber type. Unexpected developments were the discovery of new synergistic effects of the space environment in the interaction of atomic oxygen and copious amounts of contamination and in the induced luminescence of many materials.

  6. Property changes induced by the space environment in composite materials on LDEF: Solar array materials passive LDEF experiment A0171 (SAMPLE)

    SciTech Connect

    Not Available

    1993-04-01

    Surface modifications to composite materials induced by long term exposure in low earth orbit (LEO) were dominated by atomic oxygen erosion and micrometeoroid and space debris impacts. As expected, calculated erosion rates were peculiar to material type and within the predicted order of magnitude. Generally, about one ply of the carbon fiber composites was eroded during the 70 month LDEF experiment. Matrix erosion was greater than fiber erosion and was more evident for a polysulfone matrix than for epoxy matrices. Micrometeoroid and space debris impacts resulted in small (less than 1mm) craters and splattered contaminants on all samples. Surfaces became more diffuse and darker with small increases in emissivity and absorption. Tensile strength decreased roughly with thickness loss, and epoxy matrices apparently became slightly embrittled, probably as a result of continued curing under UV and/or electron bombardment. However, changes in the ultimate yield stress of the carbon reinforced epoxy composites correlate neither with weave direction nor fiber type. Unexpected developments were the discovery of new synergistic effects of the space environment in the interaction of atomic oxygen and copious amounts of contamination and in the induced luminescence of many materials.

  7. Materials science experiments in space

    NASA Technical Reports Server (NTRS)

    Gelles, S. H.; Giessen, B. C.; Glicksman, M. E.; Margrave, J. L.; Markovitz, H.; Nowick, A. S.; Verhoeven, J. D.; Witt, A. F.

    1978-01-01

    The criteria for the selection of the experimental areas and individual experiments were that the experiment or area must make a meaningful contribution to the field of material science and that the space environment was either an absolute requirement for the successful execution of the experiment or that the experiment can be more economically or more conveniently performed in space. A number of experimental areas and individual experiments were recommended for further consideration as space experiments. Areas not considered to be fruitful and others needing additional analysis in order to determine their suitability for conduct in space are also listed. Recommendations were made concerning the manner in which these materials science experiments are carried out and the related studies that should be pursued.

  8. Teenage experiments contaminate suburban property

    SciTech Connect

    Kassel, D.; Sass, W.; Lall, P.C.; Jensen, L.; Mitchell, J.

    1996-06-01

    In August 1994, 18-year-old Brian Cooper (not his real name) was detained by police in Clinton Township Michigan. When the police searched his car, they discovered a locked tool box and other containers that Brian said contained radioactive material resulting from experiments he had conducted with the radioactive material from, primarily, consumer products. From the ages 14 to 18, Brian spent his spare time at his Union Lake, Michigan, home attempting to concentrate, burn, chemically alter, and experiment with the thorium from hundreds of lantern mantles, radium from various luminescent sources and clock dials, smoke detector sources, and radioactive materials from natural ores. In the process, he had contaminated a wooden shed in his backyard and his bedroom, and injured and exposed himself. In 1995, EPA; their emergency response contractor, Ecology and Environment, Inc.; and the Michigan Department of Public Health performed an emergency assessment and removal at the property. The response and removal were conducted cost-effectively and generated approximately 10 cubic yards of radioactive waste.

  9. Microgravity Materials and Biotechnology Experiments

    NASA Technical Reports Server (NTRS)

    Vlasse, Marcus

    1998-01-01

    Presentation will deal with an overview of the Materials Science and Biotechnology/Crystal Growth flight experiments and their requirements for a successful execution. It will also deal with the hardware necessary to perform these experiments as well as the hardware requirements. This information will serve as a basis for the Abstract: workshop participants to review the poss7ibilifies for a low cost unmanned carrier and the simple automation to carry-out experiments in a microgravity environment with little intervention from the ground. The discussion will include what we have now and what will be needed to automate totally the hardware and experiment protocol at relatively low cost.

  10. 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

  11. 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].

  12. Experiments showing dynamics of materials interfaces

    SciTech Connect

    Benjamin, R.F.

    1997-02-01

    The discipline of materials science and engineering often involves understanding and controlling properties of interfaces. The authors address the challenge of educating students about properties of interfaces, particularly dynamic properties and effects of unstable interfaces. A series of simple, inexpensive, hands-on activities about fluid interfaces provides students with a testbed to develop intuition about interface dynamics. The experiments highlight the essential role of initial interfacial perturbations in determining the dynamic response of the interface. The experiments produce dramatic, unexpected effects when initial perturbations are controlled and inhibited. These activities help students to develop insight about unstable interfaces that can be applied to analogous problems in materials science and engineering. The lessons examine ``Rayleigh-Taylor instability,`` an interfacial instability that occurs when a higher-density fluid is above a lower-density fluid.

  13. Telerobotic electronic materials processing experiment

    NASA Technical Reports Server (NTRS)

    Ollendorf, Stanford

    1991-01-01

    The Office of Commercial Programs (OCP), working in conjunction with NASA engineers at the Goddard Space Flight Center, is supporting research efforts in robot technology and microelectronics materials processing that will provide many spinoffs for science and industry. The Telerobotic Materials Processing Experiment (TRMPX) is a Shuttle-launched materials processing test payload using a Get Away Special can. The objectives of the project are to define, develop, and demonstrate an automated materials processing capability under realistic flight conditions. TRMPX will provide the capability to test the production processes that are dependent on microgravity. The processes proposed for testing include the annealing of amorphous silicon to increase grain size for more efficient solar cells, thin film deposition to demonstrate the potential of fabricating solar cells in orbit, and the annealing of radiation damaged solar cells.

  14. Material Science Experiments on Mir

    NASA Technical Reports Server (NTRS)

    Kroes, Roger L.

    1999-01-01

    This paper describes the microgravity materials experiments carried out on the Shuttle/Mir program. There were six experiments, all of which investigated some aspect of diffusivity in liquid melts. The Liquid Metal Diffusion (LMD) experiment investigated the diffusivity of molten Indium samples at 185 C using a radioactive tracer, In-114m. By monitoring two different gamma ray energies (190 keV and 24 keV) emitted by the samples it was possible to measure independently the diffusion rates in the bulk and at the surface of the samples. The Queens University Experiment in Liquid Diffusion (QUELD) was the furnace facility used to process 213 samples for the five other experiments. These experiments investigated the diffusion, ripening, crystal growth, and glass formation in metal, semiconductor, and glass samples. This facility had the capability to process samples in an isothermal or gradient configuration for varying periods of time at temperatures up to 900 C. Both the LMD and the QUELD furnaces were mounted on the Microgravity Isolation Mount (MIM) which provided isolation from g-jitter. All the microgravity experiments were supported by the Space Acceleration Measurement System (SAMS); a three head three axes acceleration monitoring system which measured and recorded the acceleration environment.

  15. 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.

  16. Disk Acceleration Experiment Utilizing Minimal Material (DAXUMM)

    NASA Astrophysics Data System (ADS)

    Biss, Matthew; Lorenz, Thomas; Sutherland, Gerrit

    2015-06-01

    A venture between the US Army Research Laboratory (ARL) and Lawrence Livermore National Laboratory (LLNL) is currently underway in an effort to characterize novel energetic material performance properties using a single, high-precision, gram-range charge. A nearly all-inclusive characterization experiment is proposed by combing LLNL's disk acceleration experiment (DAX) with the ARL explosive evaluation utilizing minimal material (AXEUMM) experiment. Spherical-cap charges fitted with a flat circular metal disk are centrally initiated using an exploding bridgewire detonator while photonic doppler velocimetry is used to probe the metal disk surface velocity and measure its temporal history. The metal disk's jump-off-velocity measurement is combined with conservation equations, material Hugoniots, and select empirical relationships to determine performance properties of the detonation wave (i.e., velocity, pressure, particle velocity, and density). Using the temporal velocity history with the numerical hydrocode CTH, a determination of the energetic material's equation of state and material expansion energy is possible. Initial experimental and computational results for the plastic-bonded energetic formulation PBXN-5 are presented.

  17. Experiments to investigate particulate materials in reduced gravity fields

    NASA Technical Reports Server (NTRS)

    Bowden, M.; Eden, H. F.; Felsenthal, P.; Glaser, P. E.; Wechsler, A. E.

    1967-01-01

    Study investigates agglomeration and macroscopic behavior in reduced gravity fields of particles of known properties by measuring and correlating thermal and acoustical properties of particulate materials. Experiment evaluations provide a basis for a particle behavior theory and measure bulk properties of particulate materials in reduced gravity.

  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. 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.

  20. 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.

  1. 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.

  2. Simulation Experiments with Cometary Analogous Material

    NASA Astrophysics Data System (ADS)

    Kochan, Hermann W.; Huebner, Walter F.; Sears, Derek W. G.

    1998-12-01

    Comet simulation experiments are discussed, in the context of physical models and the results in cometary physics, gathered especially from the GIOTTO space mission to comet P'Halley. The “status of the today knowledge” about comets, the experiments could start from, is briefly reviewed. The setup of the KOSI (German = Kometen Simulation) - experiments and the techniques to produce cometary analogous material, on the basis of that knowledge are described in general, as for the different KOSI experiments. The limitations of the simulation of physical processes at the surface of real comets in an earth-bound laboratory are discussed, and the possibilities to receive common insights in cometary physics are shown. Methods and procedures are described, and the major results reviewed. As with attempting to reproduce any natural phenomenon in the laboratory, there are short-comings to these experiments, but there are possibly major new insights to be gained. Physical laws only have the same consequences under same experimental or environmental conditions. A number of small-scale comet simulation experiments have been performed, since the early 60ties in many laboratories, but the largest and most ambitious series of comet simulation experiments to date were performed between 1987 and 1993 using the German space agency's (DLR) space hardware testing facilities in Cologne. These experiments were triggered by the scientific community after the comet P'Halley's recurrence in 1986 and the many data gathered by the space missions in this year. Simulation experiments have proved valuable in developing methods for making cometary analogues, and for exploring specific properties of such materials in detail. These experiments provided new insights into the morphology and physical behavior of aggregates formed out of silicate- /water-ice -grains likely to exist in comets. The formation of a dust mantle on the surface, and a system of ice layers below the mantle from the

  3. NBS (National Bureau of Standards): Materials measurements. [space processing experiments

    NASA Technical Reports Server (NTRS)

    Manning, J. R.

    1983-01-01

    Work directed toward the measurement of materials properties important to the design and interpretation of space processing experiments and determinations of how the space environment may offer a unique opportunity for performing improved measurements and producing materials with improved properties is reported. Surface tensions and their variations with temperature and impurities; convection during undirectional solidification; and measurement of the high temperature thermophysical properties of tungsten group liquids and solids are discussed and results are summarized.

  4. Thermal Characterization of Functionally Graded Materials: Design of Optimum Experiments

    NASA Technical Reports Server (NTRS)

    Cole, Kevin D.

    2003-01-01

    This paper is a study of optimal experiment design applied to the measure of thermal properties in functionally graded materials. As a first step, a material with linearly-varying thermal properties is analyzed, and several different tran- sient experimental designs are discussed. An optimality criterion, based on sen- sitivity coefficients, is used to identify the best experimental design. Simulated experimental results are analyzed to verify that the identified best experiment design has the smallest errors in the estimated parameters. This procedure is general and can be applied to design of experiments for a variety of materials.

  5. Experiments in materials science from household items

    NASA Technical Reports Server (NTRS)

    Spiegel, F. Xavier

    1993-01-01

    Everyday household items are used to demonstrate some unique properties of materials. A coat hanger, rubber band, balloon, and corn starch have typical properties which we often take for granted but can be truly amazing.

  6. Experiences of Material Hardships among TANF Leavers

    ERIC Educational Resources Information Center

    Hunter, Tamara; Santhiveeran, Janaki

    2005-01-01

    Experiences of food insufficiencies, inadequate access to health care, and housing-related hardships represent how financial strain negatively impacts the entire family. The purpose of this study was to examine experiences of material hardships by TANF leavers and to understand factors that are associated with experiences of material hardship.…

  7. Optical properties monitor: Experiment definition phase

    NASA Technical Reports Server (NTRS)

    Wilkes, Donald R.; Bennett, Jean M.; Hummer, Leigh L.; Chipman, Russell A.; Hadaway, James B.; Pezzaniti, Larry

    1990-01-01

    The stability of materials used in the space environment will continue to be a limiting technology for space missions. The Optical Properties Monitor (OPM) Experiment provides a comprehensive space research program to study the effects of the space environment (both natural and induced) on optical, thermal and space power materials. The OPM Experiment was selected for definition under the NASA/OAST In-Space Technology Experiment Program. The results of the OPM Definition Phase are presented. The OPM experiment will expose selected materials to the space environment and measure the effects with in-space optical measurements. In-space measurements include total hemispherical reflectance total integrated scatter and VUV reflectance/transmittance. The in-space measurements will be augmented with extensive pre- and post-flight sample measurements to determine other optical, mechanical, electrical, chemical or surface effects of space exposure. Environmental monitors will provide the amount and time history of the sample exposure to solar irradiation, atomic oxygen and molecular contamination.

  8. Optical properties monitor: Experiment definition phase

    NASA Technical Reports Server (NTRS)

    Wilkes, Donald R.; Bennett, Jean M.; Hummer, Leigh L.; Chipman, Russell A.; Hadaway, James B.; Pezzaniti, Larry

    1989-01-01

    The stability of materials used in the space environment will continue to be a limiting technology for space missions. The Optical Properties Monitor (OPM) Experiment provides a comprehensive space research program to study the effects of the space environment-both natural and induced-on optical, thermal and space power materials. The OPM Experiment was selected for definition under the NASA/OAST In-Space Technology Experiment Program. The results of the OPM Definition Phase are presented. The OPM Experiment will expose selected materials to the space environment and measure the effects with in-space optical measurements. In-space measurements include total hemispherical reflectance total integrated scatter and VUV reflectance/transmittance. The in-space measurements will be augmented with extensive pre- and post-flight sample measurements to determine other optical, mechanical, electrical, chemical or surface effects of space exposure. Environmental monitors will provide the amount and time history of the sample exposure to solar irradiation, atomic oxygen and molecular contamination.

  9. 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.

  10. MCNP simulations of material exposure experiments (u)

    SciTech Connect

    Temple, Brian A

    2010-12-08

    Simulations of proposed material exposure experiments were performed using MCNP6. The experiments will expose ampules containing different materials of interest with radiation to observe the chemical breakdown of the materials. Simulations were performed to map out dose in materials as a function of distance from the source, dose variation between materials, dose variation due to ampule orientation, and dose variation due to different source energy. This write up is an overview of the simulations and will provide guidance on how to use the data in the spreadsheet.

  11. 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.

  12. 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.

  13. National Educators' Workshop. Update 92: Standard Experiments in Engineering Materials Science and Technology

    NASA Technical Reports Server (NTRS)

    Gardner, James E. (Compiler); Jacobs, James A. (Compiler); Craig, Douglas F. (Compiler)

    1993-01-01

    This document contains a collection of experiments presented and demonstrated at the workshop. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  14. MISSE Thermal Control Materials with Comparison to Previous Flight Experiments

    NASA Technical Reports Server (NTRS)

    Finckenor, Miria; Pippin, H. Gary; Frey, George

    2008-01-01

    Many different passive thermal control materials were flown as part of the Materials on International Space Station Experiment (MISSE), including inorganic coatings, anodized aluminum, and multi-layer insulation materials. These and other material samples were exposed to the low Earth orbital environment of atomic oxygen, ultraviolet radiation, thermal cycling, and hard vacuum, though atomic oxygen exposure was limited for some samples. Materials flown on MISSE-1 and MISSE-2 were exposed to the space environment for nearly four years. Materials flown on MISSE-3, MISSE-4, and MISSE-5 were exposed to the space environment for one year. Solar absorptance, infrared emittance, and mass measurements indicate the durability of these materials to withstand the space environment. Effects of short duration versus long duration exposure on ISS are explored, as well as comparable data from previous flight experiments, such as the Passive Optical Sample Assembly (POSA), Optical Properties Monitor (OPM), and Long Duration Exposure Facility (LDEF).

  15. Mechanical Properties of Cellular Materials

    SciTech Connect

    Solem, J.C.; Dienes, J.K.

    1999-07-09

    The authors calculated the stress-strain relation for elastomeric foam from an ab initio theory, which shows that the plateau and densification regions should be described by a hyperbola. The theory seems to agree reasonably well with experiment.

  16. 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

  17. Skylab materials processing facility experiment developer's report

    NASA Technical Reports Server (NTRS)

    Parks, P. G.

    1975-01-01

    The development of the Skylab M512 Materials Processing Facility is traced from the design of a portable, self-contained electron beam welding system for terrestrial applications to the highly complex experiment system ultimately developed for three Skylab missions. The M512 experiment facility was designed to support six in-space experiments intended to explore the advantages of manufacturing materials in the near-zero-gravity environment of Earth orbit. Detailed descriptions of the M512 facility and related experiment hardware are provided, with discussions of hardware verification and man-machine interfaces included. An analysis of the operation of the facility and experiments during the three Skylab missions is presented, including discussions of the hardware performance, anomalies, and data returned to earth.

  18. Tailoring material properties of sputtered beryllium

    SciTech Connect

    McEachern, R.M.

    1999-03-01

    Doped beryllium is a material of considerable interest to both the ICF and the weapons communities, as well as finding application in specialized industrial settings (e.g., x-ray windows and mirrors). Some of these uses require conformal coating of thin films on (possibly) irregularly-shaped surfaces. Physical vapor deposition (PVD) is often used to accomplish this, and sputtering is often the technique of choice. Among its advantages are that the depositing atoms are relatively energetic, leading to more compact films. Moreover, by simply applying a voltage bias to the substrate, ambient noble gas ions will bombard the growing film, which can cause further densification and other modifications to the microstructure. Sputtering is also well suited to the introduction of dopants, even those that are insoluble. Most applications of these novel materials will require fundamental knowledge of their properties. Because so many can be devised, such information is generally unavailable. The objective of the effort has been to systematically study the properties of films produced under different conditions, with an emphasis on surface finish and permeability. They have made extensive use of atomic force microscopy (AFM) and electron microscopy to determine the microstructure of the films, along with composition probes (mainly x-ray fluorescence) to quantify the chemical structure. The studies can be roughly divided into three categories. First, there are those in which the properties of pure or Cu-doped Be films have been investigated, especially on randomly-agitated spherical capsules. Included are studies of the effects of a constant substrate bias ranging from 0 to 120 v and application of an intermittent bias during deposition. Second, there are experiments in which the structure of the depositing films has been modified via the incorporation of dopants, primarily boron. Finally, there have been numerous attempts to characterize the permeability of Be coatings at

  19. 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.

  20. Lunar surface engineering properties experiment definition

    NASA Technical Reports Server (NTRS)

    Mitchell, J. K.; Goodman, R. E.; Hurlbut, F. C.; Houston, W. N.; Willis, D. R.; Witherspoon, P. A.; Hovland, H. J.

    1971-01-01

    Research on the mechanics of lunar soils and on developing probes to determine the properties of lunar surface materials is summarized. The areas of investigation include the following: soil simulation, soil property determination using an impact penetrometer, soil stabilization using urethane foam or phenolic resin, effects of rolling boulders down lunar slopes, design of borehole jack and its use in determining failure mechanisms and properties of rocks, and development of a permeability probe for measuring fluid flow through porous lunar surface materials.

  1. 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.

  2. 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.

  3. Overview of Materials International Space Station Experiment 7B

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.; Siamidis, John

    2009-01-01

    Materials International Space Station Experiment 7B (MISSE 7B) is the most recent in a series of experiments flown on the exterior of International Space Station for the purpose of determining the durability of materials and components in the space environment. A collaborative effort among the Department of Defense, the National Aeronautics and Space Administration, industry, and academia, MISSE 7B will be flying a number of NASA experiments designed to gain knowledge in the area of space environmental effects to mitigate risk for exploration missions. Consisting of trays called Passive Experiment Containers, the suitcase sized payload opens on hinges and allows active and passive experiments contained within to be exposed to the ram and wake or zenith and nadir directions in low Earth orbit, in essence, providing a test bed for atomic oxygen exposure, ultraviolet radiation exposure, charged particle radiation exposure, and thermal cycling. New for MISSE 7B is the ability to monitor experiments actively, with data sent back to Earth via International Space Station communications. NASA?s active and passive experiments cover a range of interest for the Agency. Materials relevant to the Constellation Program include: solar array materials, seal materials, and thermal protection system materials. Materials relevant to the Exploration Technology Development Program include: fabrics for spacesuits, materials for lunar dust mitigation, and new thermal control coatings. Sensors and components on MISSE 7B include: atomic oxygen fluence monitors, ultraviolet radiation sensors, and electro-optical components. In addition, fundamental space environmental durability science experiments are being flown to gather atomic oxygen erosion data and thin film polymer mechanical and optical property data relevant to lunar lander insulation and the James Web Space Telescope. This paper will present an overview of the NASA experiments to be flown on MISSE 7B, along with a summary of the

  4. Early space experiments in materials processing

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.

    1979-01-01

    A comprehensive survey of the flight experiments conducted in conjunction with the United States Materials Processing in Space Program is presented. Also included are a brief description of the conditions prevailing in an orbiting spacecraft and the research implications provided by this unique environment. What was done and what was learned are summarized in order to serve as a background for future experiments. It is assumed that the reader has some knowledge of the physical sciences but no background in spaceflight experimentation or in the materials science per se.

  5. 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.

  6. 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.

  7. Optimal Experiment Design for Thermal Characterization of Functionally Graded Materials

    NASA Technical Reports Server (NTRS)

    Cole, Kevin D.

    2003-01-01

    The purpose of the project was to investigate methods to accurately verify that designed , materials meet thermal specifications. The project involved heat transfer calculations and optimization studies, and no laboratory experiments were performed. One part of the research involved study of materials in which conduction heat transfer predominates. Results include techniques to choose among several experimental designs, and protocols for determining the optimum experimental conditions for determination of thermal properties. Metal foam materials were also studied in which both conduction and radiation heat transfer are present. Results of this work include procedures to optimize the design of experiments to accurately measure both conductive and radiative thermal properties. Detailed results in the form of three journal papers have been appended to this report.

  8. 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.

  9. Skylab Experiments, Volume 3, Materials Science.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    Basic knowledge about Skylab experiments is presented in this book, one of a series, for the purpose of informing high school teachers about scientific research performed in orbit and enabling the teachers to broaden their basis for material selection. This third volume is concerned with the effect of a weightless environment on melting and…

  10. 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.

  11. 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.

  12. 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.

  13. Stress transfer through fibrous materials in wicking experiments

    NASA Astrophysics Data System (ADS)

    Monaenkova, Daria; Andrukh, Taras; Kornev, Konstantin

    2009-11-01

    Due to the recent progress in preparation of fibers and nanofibers with different properties, the idea of smart textiles attracts much attention. In many situations the probes and sensors are designed for bio fluid detection. The liquid penetration in fibrous materials causes their deformations including stretching, twisting, wrinkling, buckling etc. The most of researches on wicking properties of textiles are focused on determination of media permeability and ignore the specific features of fibrous materials. On the other hand the theoretical works on quantitative analysis of the deformation effects in porous materials filled with liquids are mostly focused on deformation of fully saturated samples. The fundamental understanding of the stress transfer through the fiber network is crucial for sensors development, but to the best of our knowledge, the stress analysis in the fibrous materials absorbing liquids has never been discussed in the literature. This paper sets a physical basis for analysis of absorption processes in nanotubular and nanofibrous materials. We study absorption of droplets by yarns and webs made of fibers, develop a theory which explains the stress distribution in fibrous materials and checked this theory on wicking experiments. The reported theory and experiments propose a new area of research on absorption-induced deformations of fibrous materials.

  14. 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.

  15. Some functional properties of composite material based on scrap tires

    NASA Astrophysics Data System (ADS)

    Plesuma, Renate; Malers, Laimonis

    2013-09-01

    The utilization of scrap tires still obtains a remarkable importance from the aspect of unloading the environment from non-degradable waste [1]. One of the most prospective ways for scrap tires reuse is a production of composite materials [2] This research must be considered as a continuation of previous investigations [3, 4]. It is devoted to the clarification of some functional properties, which are considered important for the view of practical applications, of the composite material. Some functional properties of the material were investigated, for instance, the compressive stress at different extent of deformation of sample (till 67% of initial thickness) (LVS EN 826) [5] and the resistance to UV radiation (modified method based on LVS EN 14836) [6]. Experiments were realized on the purposefully selected samples. The results were evaluated in the correlation with potential changes of Shore C hardness (Shore scale, ISO 7619-1, ISO 868) [7, 8]. The results showed noticeable resistance of the composite material against the mechanical influence and ultraviolet (UV) radiation. The correlation with the composition of the material, activity of binder, definite technological parameters, and the conditions supported during the production, were determined. It was estimated that selected properties and characteristics of the material are strongly dependent from the composition and technological parameters used in production of the composite material, and from the size of rubber crumb. Obtained results show possibility to attain desirable changes in the composite material properties by changing both the composition and technological parameters of examined material.

  16. 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.

  17. Investigation of Structure-Property Relationships in Systematic Series of Novel Polymers. [low frequency thermomechanical spectrometry of polymeric materials - computerized torsional braid experiments

    NASA Technical Reports Server (NTRS)

    Gillham, J. K.

    1974-01-01

    The results are discussed of the on-line interface of the Torsional Braid Analysis experiment to an Hierarchical Computer System for data acquisition, data reduction and control of experimental variables. Some experimental results are demonstrated and the data reduction procedures are outlined. Several modes of presentation of the final computer-reduced data are discussed in an attempt to elucidate possible interrelations between the thermal variation of the rigidity and loss parameters.

  18. Mechanical properties of low dimensional materials

    NASA Astrophysics Data System (ADS)

    Saini, Deepika

    properties directly on a single strand of fiber, the technique was automated to allow hysteresis, creep and fatigue studies. Zinc oxide (ZnO) semiconducting nanostructures are well known for their piezoelectric properties and are being integrated into several nanoelectro-mechanical (NEMS) devices. In spite of numerous studies on the mechanical response of ZnO nanostructures, there is not a consensus in its measured bending modulus (E). In this dissertation, by employing an all-electrical Harmonic Detection of Resonance (HDR) technique on ZnO nanowhisker (NW) resonators, the underlying origin for electrically-induced mechanical oscillations in a ZnO NW was elucidated. Based on visual detection and electrical measurement of mechanical resonances under a scanning electron microscope (SEM), it was shown that the use of an electron beam as a resonance detection tool alters the intrinsic electrical character of the ZnO NW, and makes it difficult to identify the source of the charge necessary for the electrostatic actuation. A systematic study of the amplitude of electrically actuated as-grown and gold-coated ZnO NWs in the presence (absence) of an electron beam using an SEM (dark-field optical microscope) suggests that the oscillations seen in our ZnO NWs are due to intrinsic static charges. In experiments involving mechanical resonances of micro and nanostructured resonators, HDR is a tool for detecting transverse resonances and E of the cantilever material. To add to this HDR capability, a novel method of measuring the G using HDR is presented. We used a helically coiled carbon nanowire (HCNW) in singly-clamped cantilever configuration, and analyzed the complex (transverse and longitudinal) resonance behavior of the nonlinear geometry. Accordingly, a synergistic protocol was developed which (i) integrated analytical, numerical (i.e., finite element using COMSOL RTM) and experimental (HDR) methods to obtain an empirically validated closed form expression for the G and resonance

  19. 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.

  20. 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.

  1. Theory and Experiment of Chalcogenide Materials

    NASA Astrophysics Data System (ADS)

    Prasai, Binay K.

    In this dissertation, we present the experimental and theoretical investigation of extensive properties of chalcogenide materials and their potential application in solid electrolytes and phase change memory materials. Extended X-ray absorption fine structure (EXAFS) spectroscopy was employed to study the structural properties and the results were validated from the computer simulated models through ab-initio molecular dynamic (AIMD) simulations. EXAFS analysis on Ge-Sb-Te (GST) alloys, synthesized using electrodeposition and radio frequency sputtering methods confirmed the structural similarities in Ge-Te and Sb-Te bond pairs suggesting the possibility of utilizing the electrodeposition method to grow GST alloys in nanoporous materials and thus enabling miniaturizing the phase change memory devices. The analyses of structural, electronic and optical properties of computer generated amorphous and crystalline TiO 2 confirmed the structural similarities of amorphous TiO2 with the anatase phase of crystalline TiO2 and hence recommending the possibilities of replacing the crystalline TiO2 by less processed thus cheaper form of amorphous TiO2. Moreover, the AIMD simulations of the ionic conductivity of transitions metals like Ag and Cu in Ge-Se glasses confirmed the superiority of Ag over Cu in terms of conductivity. Ag was found to be easily hopping around while Cu was often trapped. In addition, an experimental and computational investigation on Ag-doped Ge-Sb-Te alloys predicted an enhanced crystallization of Ge-Sb-Te alloys. The enhanced crystallization was related to the reduction of fraction of tetrahedral Ge relative to octahedral Ge as also reflected as the increased Ge-Te bond lengths on adding Ag. Finally, further investigation of dopant-induced modification of GST alloys with transition metals (Cu, Ag and Au) demonstrated the superiority of Ag over Cu and Au regarding crystalline speed while at ˜2% dopant level no significant structural modification was

  2. High-toughness graphite/epoxy composite material experiment

    NASA Technical Reports Server (NTRS)

    Felbeck, David K.

    1993-01-01

    This experiment was designed to measure the effect of near-earth space exposure on three mechanical properties of specially toughened 5208/T300 graphite/epoxy composite materials. The properties measured are elastic modulus, strength, and fracture toughness. Six toughness specimens and nine tensile specimens were mounted on an external frame during the 5.8-year orbit of the Long Duration Exposure Facility (LDEF). Three identical sets of specimens were manufactured at the outset: the flight set, a zero-time non-flight set, and a total-time non-flight set.

  3. 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.

  4. The Sakharov Experiment Revisited for Granular Materials

    NASA Astrophysics Data System (ADS)

    Vogler, Tracy

    2013-06-01

    Sakharov and co-workers in 1965 proposed an experiment in which a sinusoidal perturbation in a planar wave evolves as it travels through a material. More recent, Liu and co-workers utilized gas gun techniques rather than explosives to drive the shock wave, resulting in a better defined input. The technique has been applied to liquids such as water and mercury as well as solids such as aluminum. All analyses of the experiments conducted to date have utilized a viscous fluid approach, even for the solids. Here, the concept of the decay of a perturbation in a shock wave is revisited and applied to granular materials. Simulations utilizing continuum models for the granular materials as well as mesoscale models in which individual particles are resolved are utilized. It is found that the perturbation decay is influenced by the strength (deviatoric behavior) used in the continuum model. In the mesocale calculations, the simulation parameters as well as the computational approach influence the results. Finally, initial experimental results for the technique using granular tungsten carbide are presented. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  5. 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.

  6. 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.

  7. 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.

  8. Analysis of materials from MSFC LDEF experiments

    NASA Technical Reports Server (NTRS)

    Johnson, R. Barry

    1991-01-01

    In preparation for the arrival of the Long Duration Exposure Facility (LDEF) samples, a material testing and handling approach was developed for the evaluation of the materials. A configured lab was made ready for the de-integration of the LDEF experiments. The lab was prepared to clean room specifications and arranged with the appropriate clean benches, tables, lab benches, clean room tools, particulate counter, and calibrated and characterized analytical instrumentation. Clean room procedures were followed. Clean room attire and shoe cleaning equipment were selected and installed for those entering. Upon arrival of the shipping crates they were taken to the lab, logged in, and opened for examination. The sample trays were then opened for inspection and test measurements. The control sample measurements were made prior to placement into handling and transport containers for the flight sample measurements and analysis. Both LDEF flight samples and LDEF type materials were analyzed and tested for future flight candidate material evaluation. Both existing and newly purchased equipment was used for the testing and evaluation. Existing Space Simulation Systems had to be upgraded to incorporate revised test objectives and approaches. Fixtures such as special configured sample holders, water, power and LN2 feed-throughs, temperature measurement and control, front surface mirrors for reflectance and deposition, and UV grade windows had to be designed, fabricated, and installed into systems to achieve the revised requirements. New equipment purchased for LDEF analysis was incorporated into and/or used with existing components and systems. A partial list of this equipment includes a portable monochromator, enhanced UV System, portable helium leak detector for porosity and leak measurements, new turbo pumping system, vacuum coaster assembly, cryopumps, and analytical and data acquisition equipment. A list of materials tested, equipment designed, fabricated and installed

  9. 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.

  10. Element Material Exposure Experiment by EFFU

    NASA Technical Reports Server (NTRS)

    Hashimoto, Yoshihiro; Ito, Masaaki; Ishii, Masahiro

    1992-01-01

    The National Space Development Agency of Japan (NASDA) is planning to perform an 'Element Material Exposure Experiment' using the Exposed Facility Flyer Unit (EFFU). This paper presents an initial design of experiments proposed for this project by our company. The EFFU is installed on the Space Flyer Unit (SFU) as a partial model of the Space Station JEM exposed facility. The SFU is scheduled to be launched by H-2 rocket in January or February of 1994, then various tests will be performed for three months, on orbit of 500 km altitude, and it will be retrieved by the U.S. Space Shuttle and returned to the ground. The mission sequence is shown.

  11. The design and modeling of periodic materials with novel properties

    NASA Astrophysics Data System (ADS)

    Berger, Jonathan Bernard

    Cellular materials are ubiquitous in our world being found in natural and engineered systems as structural materials, sound and energy absorbers, heat insulators and more. Stochastic foams made of polymers, metals and even ceramics find wide use due to their novel properties when compared to monolithic materials. Properties of these so called hybrid materials, those that combine materials or materials and space, are derived from the localization of thermomechanical stresses and strains on the mesoscale as a function of cell topology. The effects of localization can only be generalized in stochastic materials arising from their inherent potential complexity, possessing variations in local chemistry, microstructural inhomogeneity and topological variations. Ordered cellular materials on the other hand, such as lattices and honeycombs, make for much easier study, often requiring analysis of only a single unit-cell. Theoretical bounds predict that hybrid materials have the potential to push design envelopes offering lighter stiffer and stronger materials. Hybrid materials can achieve very low and even negative coefficients of thermal expansion (CTE) while retaining a relatively high stiffness -- properties completely unmatched by monolithic materials. In the first chapter of this thesis a two-dimensional lattice is detailed that possess near maximum stiffness, relative to the tightest theoretical bound, and low, zero and even appreciably negative thermal expansion. Its CTE and stiffness are given in closed form as a function of geometric parameters and the material properties. This result is confirmed with finite elements (FE) and experiment. In the second chapter the compressive stiffness of three-dimensional ordered foams, both closed and open cell, are predicted with FE and the results placed in property space in terms of stiffness and density. A novel structure is identified that effectively achieves theoretical bounds for Young's, shear and bulk modulus

  12. 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.

  13. Summaries of early materials processing in space experiments

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.; Mason, D.

    1979-01-01

    Objectives, methods, and results of low-gravity materials processing experiments are summarized, and a bibliography of published results for each experiment is provided. Included are drop tower experiments, the Apollo demonstration experiments, the skylab experiments and demonstration experiments, and the Apollo-Soyuz experiments and demonstrations. The findings of these experiments in the fields of crystal growth, metallurgy, and fluid behavior are summarized.

  14. 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.

  15. Stratospheric experiments on curing of composite materials

    NASA Astrophysics Data System (ADS)

    Chudinov, Viacheslav; Kondyurin, Alexey; Svistkov, Alexander L.; Efremov, Denis; Demin, Anton; Terpugov, Viktor; Rusakov, Sergey

    2016-07-01

    Future space exploration requires a large light-weight structure for habitats, greenhouses, space bases, space factories and other constructions. A new approach enabling large-size constructions in space relies on the use of the technology of polymerization of fiber-filled composites with a curable polymer matrix applied in the free space environment on Erath orbit. In orbit, the material is exposed to high vacuum, dramatic temperature changes, plasma of free space due to cosmic rays, sun irradiation and atomic oxygen (in low Earth orbit), micrometeorite fluence, electric charging and microgravitation. The development of appropriate polymer matrix composites requires an understanding of the chemical processes of polymer matrix curing under the specific free space conditions to be encountered. The goal of the stratospheric flight experiment is an investigation of the effect of the stratospheric conditions on the uncured polymer matrix of the composite material. The unique combination of low residual pressure, high intensity UV radiation including short-wave UV component, cosmic rays and other aspects associated with solar irradiation strongly influences the chemical processes in polymeric materials. We have done the stratospheric flight experiments with uncured composites (prepreg). A balloon with payload equipped with heater, temperature/pressure/irradiation sensors, microprocessor, carrying the samples of uncured prepreg has been launched to stratosphere of 25-30 km altitude. After the flight, the samples have been tested with FTIR, gel-fraction, tensile test and DMA. The effect of cosmic radiation has been observed. The composite was successfully cured during the stratospheric flight. The study was supported by RFBR grants 12-08-00970 and 14-08-96011.

  16. Pressure-shear experiments on granular materials.

    SciTech Connect

    Reinhart, William Dodd; Thornhill, Tom Finley, III; Vogler, Tracy John; Alexander, C. Scott

    2011-10-01

    Pressure-shear experiments were performed on granular tungsten carbide and sand using a newly-refurbished slotted barrel gun. The sample is a thin layer of the granular material sandwiched between driver and anvil plates that remain elastic. Because of the obliquity, impact generates both a longitudinal wave, which compresses the sample, and a shear wave that probes the strength of the sample. Laser velocity interferometry is employed to measure the velocity history of the free surface of the anvil. Since the driver and anvil remain elastic, analysis of the results is, in principal, straightforward. Experiments were performed at pressures up to nearly 2 GPa using titanium plates and at higher pressure using zirconium plates. Those done with the titanium plates produced values of shear stress of 0.1-0.2 GPa, with the value increasing with pressure. On the other hand, those experiments conducted with zirconia anvils display results that may be related to slipping at an interface and shear stresses mostly at 0.1 GPa or less. Recovered samples display much greater particle fracture than is observed in planar loading, suggesting that shearing is a very effective mechanism for comminution of the grains.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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...

  2. 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...

  3. 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...

  4. 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...

  5. 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...

  6. Specimens Prepared for Materials International Space Station Experiment

    NASA Technical Reports Server (NTRS)

    Banks, Bruce A.; deGroh, Kim K.; Dever, Joyce A.; Jaworske, Donald A.; Miller, Sharon K.; Snyder, Aaron; Sechkar, Edward A.

    2001-01-01

    The Materials International Space Station Experiment (MISSE) is a materials flight experiment sponsored by the Materials and Manufacturing Directorate of the Air Force Research Laboratory at Wright-Patterson Air Force Base and the NASA Space Environmental Effects Program at the NASA Marshall Space Flight Center. MISSE is a cooperative effort among the Air Force, several NASA field centers, and industry. The experiment package will be placed on the exterior of the International Space Station in the summer of 2001. Approximately half of the specimens will be exposed to the space environment for 1 year, and the other half will be exposed for 3 years. The Electro-Physics Branch at the NASA Glenn Research Center has prepared and delivered over 150 specimens to be included in MISSE. Specimens include: 1) Double-coated polyimide Kapton to compare mass loss from in-space atomic oxygen undercutting erosion to ground-laboratory atomic oxygen undercutting erosion for predicting in-space durability; 2) Silicones to study changes in surface hardness and optical properties after combined atomic oxygen--ultraviolet radiation exposure for predicting in-space durability; 3) Forty-one different polymers to accurately measure their atomic oxygen erosion yields; 4) Scattering chambers to study atomic oxygen scattering characteristics that are relevant to the degradation found in spacecraft with exterior openings; 5) Thin polymer film disks and tensile specimens to study the effects of radiation on their optical properties and mechanical properties; 6) Lightweight intercalated graphite epoxy composites to study electromagnetic interference shielding performance; and 7) Polymer-based materials utilizing new atomic oxygen protection concepts to study their durability.

  7. 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.

  8. 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.

  9. Determining significant material properties: A discovery approach

    NASA Technical Reports Server (NTRS)

    Karplus, Alan K.

    1992-01-01

    The following is a laboratory experiment designed to further understanding of materials science. The experiment itself can be informative for persons of any age past elementary school, and even for some in elementary school. The preparation of the plastic samples is readily accomplished by persons with resonable dexterity in the cutting of paper designs. The completion of the statistical Design of Experiments, which uses Yates' Method, requires basic math (addition and subtraction). Interpretive work requires plotting of data and making observations. Knowledge of statistical methods would be helpful. The purpose of this experiment is to acquaint students with the seven classes of recyclable plastics, and provide hands-on learning about the response of these plastics to mechanical tensile loading.

  10. 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

  11. Experiments investigating advanced materials under thermomechanical loading

    NASA Technical Reports Server (NTRS)

    Bartolotta, Paul A.

    1988-01-01

    Many high temperature aircraft and rocket engine components experience large mechanical loads as well as severe thermal gradients and transients. These nonisothermal conditions are often large enough to cause inelastic deformations, which are the ultimate cause for failure in those parts. A way to alleviate this problem is through improved engine designs based on better predictions of thermomechanical material behavior. To address this concern, an experimental effort was recently initiated within the Hot Section Technology (HOST) program at Lewis. As part of this effort, two new test systems were added to the Fatigue and Structures Lab., which allowed thermomechanical tests to be conducted under closely controlled conditions. These systems are now being used for thermomechanical testing for the Space Station Receiver program, and will be used to support development of metal matrix composites.

  12. 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.

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. Computing estimates of material properties from transmission eigenvalues

    NASA Astrophysics Data System (ADS)

    Giorgi, Giovanni; Haddar, Houssem

    2012-05-01

    This work is motivated by inverse scattering problems, those problems where one is interested in reconstructing the shape and the material properties of an inclusion from electromagnetic farfield measurements. More precisely, we are interested in complementing the so-called sampling methods by providing an estimate of the material properties of the sought inclusion. We use for this purpose a measure of the first transmission eigenvalue. Our method is then based on computing the desired estimate by reformulating the so-called interior transmission eigenvalue problem as an eigenvalue problem for the material coefficients. We will restrict ourselves to the two-dimensional setting of the problem and treat the cases of both transverse electric and transverse magnetic polarizations. We present a number of numerical experiments that validate our methodology for homogeneous and inhomogeneous inclusions and backgrounds. We also treat the case of a background with absorption and the case of scatterers with multiple connected components of different refractive indices.

  18. Optical techniques for determining dynamic material properties

    SciTech Connect

    Paisley, D.L.; Stahl, D.B.

    1996-12-31

    Miniature plates are laser-launched with a 10-Joule Nd:YAG for one-dimensional (1-D) impacts on to target materials much like gas gun experiments and explosive plane wave plate launch. By making the experiments small, flyer plates (3 mm diameter x 50 micron thick) and targets (10 mm diameter x 200 micron thick), 1-D impact experiments can be performed in a standard laser-optical laboratory with minimum confinement and collateral damage. The laser-launched plates do not require the traditional sabot on gas guns nor the explosives needed for explosive planewave lenses, and as a result are much more amenable to a wide variety of materials and applications. Because of the small size very high pressure gradients can be generated with relative ease. The high pressure gradients result in very high strains and strain rates that are not easily generated by other experimental methods. The small size and short shock duration (1 - 20 ns) are ideal for dynamically measuring bond strengths of micron-thick coatings. Experimental techniques, equipment, and dynamic material results are reported.

  19. 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

  20. National Educators' Workshop: Update 1991. Standard Experiments in Engineering Materials Science and Technology

    NASA Technical Reports Server (NTRS)

    Gardner, James E. (Compiler); Jacobs, James A. (Compiler); Stiegler, James O. (Compiler)

    1992-01-01

    Given here is a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 91, held at the Oak Ridge National Laboratory on November 12-14, 1991. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  1. National Educators' Workshop: Update 95. Standard Experiments in Engineering Materials Science and Technology

    NASA Technical Reports Server (NTRS)

    Gardner, James E. (Compiler); Jacobs, James A.; Karnitz, Michael A.

    1996-01-01

    This document contains a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 95. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  2. National Educators' Workshop: Update 1997. Standard Experiments in Engineering Materials, Science, and Technology

    NASA Technical Reports Server (NTRS)

    Gardner, James E. (Compiler); Freeman, Ginger L. (Compiler); Jacobs, James A. (Compiler); Miller, Alan G. (Compiler); Smith, Brian W. (Compiler)

    1998-01-01

    This document contains a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 97, held at Boeing Commercial Airplane Group, Seattle, Washington, on November 2-5, 1997. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  3. National Educators' Workshop: Update 1994. Standard experiments in engineering materials science and technology

    NASA Technical Reports Server (NTRS)

    Gardner, James E. (Compiler); Jacobs, James A. (Compiler); Fraker, Anna C. (Compiler)

    1995-01-01

    This document contains a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 94. The experiments relate to the nature and properties of engineering materials and provide information to assist in teaching about materials in the education community.

  4. National Educators' Workshop: Update 1989 Standard Experiments in Engineering Materials Science and Technology

    NASA Technical Reports Server (NTRS)

    Gardner, James E. (Compiler); Jacobs, James A. (Compiler)

    1990-01-01

    Presented here is a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 89, held October 17 to 19, 1989 at the National Aeronautics and Space Administration, Hampton, Virginia. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  5. National Educators' Workshop: Update 1988. Standard Experiments in Engineering Materials Science and Technology

    NASA Technical Reports Server (NTRS)

    Gardner, James E. (Compiler); Jacobs, James A. (Compiler)

    1990-01-01

    Presented here is a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 88, held May 10 to 12, 1988 at the National Institute of Standards and Technology (NIST), Gaithersberg, Maryland. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  6. National Educators' Workshop: Update 1993. Standard Experiments in Engineering Materials Science and Technology

    NASA Technical Reports Server (NTRS)

    Gardner, James E. (Compiler); Jacobs, James A. (Compiler)

    1994-01-01

    This document contains a collection of experiments presented and demonstrated at the National Educators' Workshop: Update 93 held at the NASA Langley Research Center in Hampton, Virginia, on November 3-5, 1993. The experiments related to the nature and properties of engineering materials and provided information to assist in teaching about materials in the education community.

  7. 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.

  8. 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.

  9. Pulsed power accelerator for material physics experiments

    NASA Astrophysics Data System (ADS)

    Reisman, D. B.; Stoltzfus, B. S.; Stygar, W. A.; Austin, K. N.; Waisman, E. M.; Hickman, R. J.; Davis, J.-P.; Haill, T. A.; Knudson, M. D.; Seagle, C. T.; Brown, J. L.; Goerz, D. A.; Spielman, R. B.; Goldlust, J. A.; Cravey, W. R.

    2015-09-01

    We have developed the design of Thor: a pulsed power accelerator that delivers a precisely shaped current pulse with a peak value as high as 7 MA to a strip-line load. The peak magnetic pressure achieved within a 1-cm-wide load is as high as 100 GPa. Thor is powered by as many as 288 decoupled and transit-time isolated bricks. Each brick consists of a single switch and two capacitors connected electrically in series. The bricks can be individually triggered to achieve a high degree of current pulse tailoring. Because the accelerator is impedance matched throughout, capacitor energy is delivered to the strip-line load with an efficiency as high as 50%. We used an iterative finite element method (FEM), circuit, and magnetohydrodynamic simulations to develop an optimized accelerator design. When powered by 96 bricks, Thor delivers as much as 4.1 MA to a load, and achieves peak magnetic pressures as high as 65 GPa. When powered by 288 bricks, Thor delivers as much as 6.9 MA to a load, and achieves magnetic pressures as high as 170 GPa. We have developed an algebraic calculational procedure that uses the single brick basis function to determine the brick-triggering sequence necessary to generate a highly tailored current pulse time history for shockless loading of samples. Thor will drive a wide variety of magnetically driven shockless ramp compression, shockless flyer plate, shock-ramp, equation of state, material strength, phase transition, and other advanced material physics experiments.

  10. 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.

  11. Machine-learning-assisted materials discovery using failed experiments.

    PubMed

    Raccuglia, Paul; Elbert, Katherine C; Adler, Philip D F; Falk, Casey; Wenny, Malia B; Mollo, Aurelio; Zeller, Matthias; Friedler, Sorelle A; Schrier, Joshua; Norquist, Alexander J

    2016-05-01

    Inorganic-organic hybrid materials such as organically templated metal oxides, metal-organic frameworks (MOFs) and organohalide perovskites have been studied for decades, and hydrothermal and (non-aqueous) solvothermal syntheses have produced thousands of new materials that collectively contain nearly all the metals in the periodic table. Nevertheless, the formation of these compounds is not fully understood, and development of new compounds relies primarily on exploratory syntheses. Simulation- and data-driven approaches (promoted by efforts such as the Materials Genome Initiative) provide an alternative to experimental trial-and-error. Three major strategies are: simulation-based predictions of physical properties (for example, charge mobility, photovoltaic properties, gas adsorption capacity or lithium-ion intercalation) to identify promising target candidates for synthetic efforts; determination of the structure-property relationship from large bodies of experimental data, enabled by integration with high-throughput synthesis and measurement tools; and clustering on the basis of similar crystallographic structure (for example, zeolite structure classification or gas adsorption properties). Here we demonstrate an alternative approach that uses machine-learning algorithms trained on reaction data to predict reaction outcomes for the crystallization of templated vanadium selenites. We used information on 'dark' reactions--failed or unsuccessful hydrothermal syntheses--collected from archived laboratory notebooks from our laboratory, and added physicochemical property descriptions to the raw notebook information using cheminformatics techniques. We used the resulting data to train a machine-learning model to predict reaction success. When carrying out hydrothermal synthesis experiments using previously untested, commercially available organic building blocks, our machine-learning model outperformed traditional human strategies, and successfully predicted conditions

  12. Machine-learning-assisted materials discovery using failed experiments

    NASA Astrophysics Data System (ADS)

    Raccuglia, Paul; Elbert, Katherine C.; Adler, Philip D. F.; Falk, Casey; Wenny, Malia B.; Mollo, Aurelio; Zeller, Matthias; Friedler, Sorelle A.; Schrier, Joshua; Norquist, Alexander J.

    2016-05-01

    Inorganic–organic hybrid materials such as organically templated metal oxides, metal–organic frameworks (MOFs) and organohalide perovskites have been studied for decades, and hydrothermal and (non-aqueous) solvothermal syntheses have produced thousands of new materials that collectively contain nearly all the metals in the periodic table. Nevertheless, the formation of these compounds is not fully understood, and development of new compounds relies primarily on exploratory syntheses. Simulation- and data-driven approaches (promoted by efforts such as the Materials Genome Initiative) provide an alternative to experimental trial-and-error. Three major strategies are: simulation-based predictions of physical properties (for example, charge mobility, photovoltaic properties, gas adsorption capacity or lithium-ion intercalation) to identify promising target candidates for synthetic efforts; determination of the structure–property relationship from large bodies of experimental data, enabled by integration with high-throughput synthesis and measurement tools; and clustering on the basis of similar crystallographic structure (for example, zeolite structure classification or gas adsorption properties). Here we demonstrate an alternative approach that uses machine-learning algorithms trained on reaction data to predict reaction outcomes for the crystallization of templated vanadium selenites. We used information on ‘dark’ reactions—failed or unsuccessful hydrothermal syntheses—collected from archived laboratory notebooks from our laboratory, and added physicochemical property descriptions to the raw notebook information using cheminformatics techniques. We used the resulting data to train a machine-learning model to predict reaction success. When carrying out hydrothermal synthesis experiments using previously untested, commercially available organic building blocks, our machine-learning model outperformed traditional human strategies, and successfully

  13. Science Data Report for the Optical Properties Monitor (OPM) Experiment

    NASA Technical Reports Server (NTRS)

    Wilkes, D. R.; Zwiener, J. M.; Carruth, Ralph (Technical Monitor)

    2001-01-01

    This science data report describes the Optical Properties Monitor (OPM) experiment and the data gathered during its 9-mo exposure on the Mir space station. Three independent optical instruments made up OPM: an integrating sphere spectral reflectometer, vacuum ultraviolet spectrometer, and a total integrated scatter instrument. Selected materials were exposed to the low-Earth orbit, and their performance monitored in situ by the OPM instruments. Coinvestigators from four NASA Centers, five International Space Station contractors, one university, two Department of Defense organizations, and the Russian space company, Energia, contributed samples to this experiment. These materials included a number of thermal control coatings, optical materials, polymeric films, nanocomposites, and other state-of-the-art materials. Degradation of some materials, including aluminum conversion coatings and Beta cloth, was greater than expected. The OPM experiment was launched aboard the Space Shuttle on mission STS-81 in January 1997 and transferred to the Mir space station. An extravehicular activity (EVA) was performed in April 1997 to attach the OPM experiment to the outside of the Mir/Shuttle Docking Module for space environment exposure. OPM was retrieved during an EVA in January 1998 and was returned to Earth on board the Space Shuttle on mission STS-89.

  14. 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.

  15. 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.

  16. Five experiments in materials science for less than $10.00

    NASA Technical Reports Server (NTRS)

    Spiegel, F. Xavier

    1992-01-01

    Diffusion, twinning, fatigue, acoustic emission, and aging can be studied using readily available materials and the household oven. Each experiment can be expanded to a more extensive investigation of the properties of the material investigated, as well as other materials, and offers an opportunity for the student to learn about the relationship between engineering, science, society, and politics.

  17. 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.

  18. Characterization of the electromechanical properties of EAP materials

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Yoseph; Sherrita, Stewart; Bhattachary, Kaushik; Lih, Shyh-Shiuh

    2001-01-01

    Electroactive polymers (EAP) are an emerging class of actuation materials. Their large electrically induced strains (longitudinal or bending), low density, mechanical flexibility, and ease of processing offer advantages over traditional electroactive materials. However, before the capability of these materials can be exploited, their electrical and mechanical behavior must be properly quantified. Two general types of EAP can be identified. The first type is ionic EAP, which requires relatively low voltages (<10V) to achieve large bending deflections. This class usually needs to be hydrated and electrochemical reactions may occur. The second type is Electronic-EAP and it involves electrostrictive and/or Maxwell stresses. This type of materials requires large electric fields (>100MV/m) to achieve longitudinal deformations at the range from 4 - 360%. Some of the difficulties in characterizing EAP include: nonlinear properties, large compliance (large mismatch with metal electrodes), nonhomogeneity resulting from processing, etc. To support the need for reliable data, the authors are developing characterization techniques to quantify the electroactive responses and material properties of EAP materials. The emphasis of the current study is on addressing electromechanical issues related to the ion-exchange type EAP also known as IPMC. The analysis, experiments and test results are discussed in this paper.

  19. Interdisciplinary research on the nature and properties of ceramic materials

    NASA Technical Reports Server (NTRS)

    1980-01-01

    Several investigations concerning the properties and processing of brittle ceramic materials as related to design considerations are briefly described. Surface characterization techniques, fractography, high purity materials, creep properties, impact and thermal shock resistance, and reaction bonding are discussed.

  20. Materials Science Experiments on the International Space Station

    NASA Technical Reports Server (NTRS)

    Gillies, Donald C.

    1999-01-01

    The Performance Goal for NASA's Microgravity Materials Science Program reads "Use microgravity to establish and improve quantitative and predictive relationships between the structure, processing and properties of materials." The advent of the International Space Station will open up a new era in Materials Science Research including the ability to perform long term and frequent experiments in microgravity. As indicated the objective is to gain a greater understanding of issues of materials science in an environment in which the force of gravity can be effectively switched off. Thus gravity related issues of convection, buoyancy and hydrostatic forces can be reduced and the science behind the structure/processing/properties relationship can more easily be understood. The specific areas of research covered within the program are (1) the study of Nucleation and Metastable States, (2) Prediction and Control of Microstructure (including pattern formation and morphological stability), (3) Phase Separation and Interfacial Stability, (4) Transport Phenomena (including process modeling and thermophysical properties measurement), and (5) Crystal Growth, and Defect Generation and Control. All classes of materials, including metals and alloys, glasses and ceramics, polymers, electronic materials (including organic and inorganic single crystals), aerogels and nanostructures, are included in these areas. The principal experimental equipment available to the materials scientist on the International Space Station (ISS) will be the Materials Science Research Facility (MSRF). Each of these systems will be accommodated in a single ISS rack, which can operate autonomously, will accommodate telescience operations, and will provide real time data to the ground. Eventual plans call for three MSRF racks, the first of which will be shared with the European Space Agency (ESA). Under international agreements, ESA and other partners will provide some of the equipment, while NASA covers launch

  1. New Technique for Evaluating Adhesion Properties between Soft Materials

    NASA Astrophysics Data System (ADS)

    Sato, Takaya; Goto, Motoaki; Nakano, Ken; Suzuki, Atsushi

    2005-11-01

    A new, simple apparatus for measuring the surface adhesion properties of soft materials was designed, where the adhesion force of a point contact between soft materials and the total energy required to separate the contact can be measured using the springs of phosphor-bronze thin plates with strain gauges. The adhesion between swollen hydrogels was studied here by this simple technique in air at room temperature. The gels used in the present preliminary experiments were poly(sodium acrylate) hydrogels physically cross-linked by aluminum ions. The adhesion force and the separation energy showed a power-law increase with separation velocity. The apparatus was applied to evaluate the adhesion properties of seven anti-inflammatory analgesic cataplasms on the market. It was found that the easiness to separate (rank of adhesion force and the separation energy) was consistent with the results of those obtained by organoleptic evaluations.

  2. Exposure of Polymer Film Thermal Control Materials on the Materials International Space Station Experiment (MISSE)

    NASA Technical Reports Server (NTRS)

    Dever, Joyce; Miller, Sharon; Messer, Russell; Sechkar, Edward; Tollis, Greg

    2002-01-01

    Seventy-nine samples of polymer film thermal control (PFTC) materials have been provided by the National Aeronautics and Space Administration (NASA) Glenn Research Center (GRC) for exposure to the low Earth orbit environment on the exterior of the International Space Station (ISS) as part of the Materials International Space Station Experiment (MISSE). MISSE is a materials flight experiment sponsored by the Air Force Research Lab/Materials Lab and NASA. This paper will describe background, objectives, and configurations for the GRC PFTC samples for MISSE. These samples include polyimides, fluorinated polyimides, and Teflon fluorinated ethylene propylene (FEP) with and without second-surface metallizing layers and/or surface coatings. Also included are polyphenylene benzobisoxazole (PBO) and a polyarylene ether benzimidazole (TOR-LM). On August 16, 2001, astronauts installed passive experiment carriers (PECs) on the exterior of the ISS in which were located twenty-eight of the GRC PFTC samples for 1-year space exposure. MISSE PECs for 3-year exposure, which will contain fifty-one GRC PFTC samples, will be installed on the ISS at a later date. Once returned from the ISS, MISSE GRC PFTC samples will be examined for changes in optical and mechanical properties and atomic oxygen (AO) erosion. Additional sapphire witness samples located on the AO exposed trays will be examined for deposition of contaminants.

  3. Role of defects in frictional properties of 2-D materials

    NASA Astrophysics Data System (ADS)

    Kavalur, Aditya; Kim, Woo Kyun

    Graphene and other 2-D materials have provided a promising prospect to improve the tribological properties of small length scale devices such as MEMS/NEMS due to their low friction coefficient and excellent wear resistance. Several recent research efforts have been devoted to unveiling the physical origin of the superior tribological properties of these 2-D materials from both experimental and theoretical standpoints, however, many of them still remain far from clearly understood. Recently, it was shown that lamellar materials do not conform to the predictions of the Prandtl-Tomlinson model due to additional friction mechanisms of delamination and visco-elastic ploughing. These mechanisms are critical as they explain the low and negative coefficients of friction observed in recent AFM experiments. However, thus far, most simulation and theoretical studies about these novel friction mechanisms have focused on only pristine graphene whereas real graphene sheets prepared by CVD and other conventional techniques possess various forms of defects such as vacancies and non-hexagonal rings. In this study we examine the role of these defects in frictional properties of 2-D materials in relation to delamination and visco-elastic ploughing.

  4. Science Data Report for the Optical Properties Monitor (OPM) Experiment

    NASA Technical Reports Server (NTRS)

    Wilkes, Donald R.; Zwiener, James M.

    1999-01-01

    Long term stability of spacecraft materials when exposed to the space environment continues to be a major area of investigation. The natural and induced environment surrounding a spacecraft can decrease material performance and limit useful lifetimes. The Optical Properties Monitor (OPM) experiment provided the capability to perform the important flight testing of materials and was flown on the Russian Mir Station to study the long term effects of the natural and induced space environment on materials. The core of the OPM in-flight analysis was three independent optical instruments. These instruments included an integrating sphere spectral reflectometer, a vacuum ultraviolet spectrometer, and a Total Integrated Scatter instrument. The OPM also monitored selected components of the environment including molecular contamination. The OPM was exposed on the exterior of the Mir Docking Module for approximately 8-1/2 months. This report describes the OPM experiment, a brief background of its development, program organization, experiment description, mission overview including space environment definition, performance overview, materials data including flight and ground data, in-depth post flight analysis including ground analysis measurements and a summary discussion of the findings and results.

  5. Auditory perception of geometry-invariant material properties.

    PubMed

    Ren, Zhimin; Yeh, Hengchin; Klatzky, Roberta; Lin, Ming C

    2013-04-01

    Accurately modeling the intrinsic material-dependent damping property for interactive sound rendering is a challenging problem. The Rayleigh damping model is commonly regarded as an adequate engineering model for interactive sound synthesis in virtual environment applications, but this assumption has never been rigorously analyzed. In this paper, we conduct a formal evaluation of this model. Our goal is to determine if auditory perception of material under Rayleigh damping assumption is 'geometry-invariant', i.e. if this approximation model is transferable across different shapes and sizes. First, audio recordings of same-material objects in various shapes and sizes are analyzed to determine if they can be approximated by the Rayleigh damping model with a single set of parameters. Next, we design and conduct a series of psychoacoustic experiments, in subjects evaluate if audio clips synthesized using the Rayleigh damping model are from the same material, when we alter the material, shape, and size parameters. Through both quantitative and qualitative evaluation, we show that the acoustic properties of the Rayleigh damping model for a single material is generally preserved across different geometries of objects consisting of homogeneous materials and is therefore a suitable, geometry-invariant sound model. Our study results also show that consistent with prior crossmodal expectations, visual perception of geometry can affect the auditory perception of materials. These findings facilitate the wide adoption of Rayleigh damping for interactive auditory systems and enable reuse of material parameters under this approximation model across different shapes and sizes, without laborious per-object parameter tuning. PMID:23428439

  6. Viking magnetic properties experiment - Extended mission results

    NASA Technical Reports Server (NTRS)

    Hargraves, R. B.; Collinson, D. W.; Arvidson, R. E.; Cates, P. M.

    1979-01-01

    The backhoe magnets on Viking Lander (VL) 2 were successfully cleaned, followed by a test involving successive insertions of the cleaned backhoe into the surface. Rapid saturation of the magnets confirmed evidence from primary mission results that the magnetic mineral in the Martian surface is widely distributed, most probably in the form of composite particles of magnetic and nonmagnetic minerals. An image of the VL 2 backhoe taken via the X4 magnifying mirror demonstrates the fine-grained nature of the attracted magnetic material. The presence of maghemite and its occurrence as a pigment in, or a thin coating on, all mineral particles or as discrete, finely divided and widely distributed crystallites, are consistent with data from the inorganic analysis experiments and with laboratory simulations of results of the biology experiments on Mars.

  7. 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.

  8. Corrosion and tribological properties of basalt fiber reinforced composite materials

    NASA Astrophysics Data System (ADS)

    Ha, Jin Cheol; Kim, Yun-Hae; Lee, Myeong-Hoon; Moon, Kyung-Man; Park, Se-Ho

    2015-03-01

    This experiment has examined the corrosion and tribological properties of basalt fiber reinforced composite materials. There were slight changes of weight after the occurring of corrosion based on time and H2SO4 concentration, but in general, the weight increased. It is assumed that this happens due to the basalt fiber precipitate. Prior to the corrosion, friction-wear behavior showed irregular patterns compared to metallic materials, and when it was compared with the behavior after the corrosion, the coefficient of friction was 2 to 3 times greater. The coefficient of friction of all test specimen ranged from 0.1 to 0.2. Such a result has proven that the basalt fiber, similar to the resin rubber, shows regular patterns regardless of time and H2SO4 concentration because of the space made between resins and reinforced materials.

  9. Materials processing in space: Early experiments

    NASA Technical Reports Server (NTRS)

    Naumann, R. J.; Herring, H. W.

    1980-01-01

    The characteristics of the space environment were reviewed. Potential applications of space processing are discussed and include metallurgical processing, and processing of semiconductor materials. The behavior of fluid in low gravity is described. The evolution of apparatus for materials processing in space was reviewed.

  10. Interdisciplinary research on the nature and properties of ceramic materials

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The advancement of material performance and design methodology as related to brittle materials was investigated. The processing and properties of ceramic materials as related to design requirements was also studied.

  11. Material properties of concentrated pectin networks.

    PubMed

    Zsivanovits, Gabor; MacDougall, Alistair J; Smith, Andrew C; Ring, Stephen G

    2004-05-17

    We have examined the mechanical behaviour of different types of pectin at high concentrations (> 30% w/w), relevant to the behaviour of pectin in the plant cell wall, and as a film-forming agent. Mechanical properties were examined as a function of counterion type (K(+), Ca(2+), Mg(2+)), concentration and extent of hydration. Hydration was controlled in an osmotic stress experiment where pectin films were exposed to concentrated polyethylene glycol [PEG] solutions of known osmotic pressure. We investigated the mechanical behaviour under simple extension. The results show that the swelling and stiffness of the films are strongly dependent on pectin source and ionic environment. At a fixed osmotic stress, both Ca(2+) or Mg(2+) counterions reduce swelling and increase the stiffness of the film. PMID:15113669

  12. Viscoelastic properties and compaction behaviour of pharmaceutical particulate materials

    NASA Astrophysics Data System (ADS)

    Tsardaka, Ekaterini D.

    1990-01-01

    The viscoelastic behaviour of particulate solids is of major relevance in powder compaction. When designing a pharmaceutical tablet formulation, it is highly undesirable for the tablet properties to be markedly affected by changes in compaction rate on different tablet presses, if problems are to be avoided during scale-up and manufacture. In order to be able to predict and minimise the time-dependent deformation of pharmaceutical powders, a full understanding of such behaviour is needed. For comparative purposes, a range of materials with differing compaction properties were studied. Heckel plots were extended in order to study the consolidation behaviour of materials during compression, decompression and after ejection. A number of derived parameters were proposed as a useful means of assessing the viscoelastic characteristics of materials. The mechanical properties of the tablets produced were assessed by means of both a diametral loading test and a direct tension test, in order to study the homogeneity of tablets with respect to strength and toughness. Fitting stress relaxation data to a hyperbolic equation enabled the asymptotic value of relaxed stress and the rate of stress relaxation at short times to be determined. Creep analysis was found to be a most useful method in quantifying the viscoelastic properties of materials. Creep experiments were used to separately quantify the ability of a material to undergo elastic, viscoelastic and plastic deformation at constant stress. Analysis of the viscoelastic compliance provided a time constant and an equilibrium value. Spectral analysis of the creep data was an alternative method of studying viscoelastic behaviour, since analysis in the frequency domain revealed hidden periodicities of mechanisms possibly related to viscoelastic behaviour. A detailed study of several forms of modified starch addressed factors which may influence its viscoelastic behaviour, including manufacturing process variables such as particle

  13. Organic/inorganic nanocomposite materials by electrospinning and their properties

    NASA Astrophysics Data System (ADS)

    Wang, Guan

    One-dimensional (1D) nanostructures, such as nanowires, nanobelts, nanofibers and nanotubes, have been the focus of intensive research due to their peculiar structures and resultant fascinating properties. However, the applications of 1D nanostructures have been hindered by the slow progress of the synthesis and characterization methods for these nanoscaled materials. Well controlled dimensionality, tailorable morphology and assembly, high phase purity and controllable crystallinity are major concerns when generating these nanostructures. In this work, a relatively simple technique---electrospinning---has been introduced for the preparation of 1D organic/inorganic nanocomposite materials. Materials under investigation include polymer/metal oxide (WO 3, MoO3) composite nanofibers and polymer/MWNT composite nanofibers. Notably, peculiar nanostructures, such as polycrystalline nanowires, nanoplatelets and nanobelts, can also be obtained after post-calcination processing on the nanocomposite materials. Spectroscopy techniques, such as XRD, SEM, TEM, AFM and Raman have been carried out to obtain structural and morphological information from the electrospun composite nanofibers. Meanwhile, some advanced characterization methods and measurements have been developed and designed to investigate the nanofibers from a basic science view point as to their properties. Specific designs of experiment include: synchrotron-based in situ XRD for phase transition monitoring; gas flow control bench for sensitivity measurement; three-point-bending by AFM for mechanical property measurement. In summary, the electrospinning technique provides a versatile method for synthesizing and assembling 1D nanocomposite structures. The electrospun composite nanofibers showed promising electrical and mechanical properties, which may find applications for gas sensors, reinforced fibrous materials and nano-electrical devices.

  14. Helium retention properties of plasma facing materials

    NASA Astrophysics Data System (ADS)

    Yanagihara, H.; Yamauchi, Y.; Hino, T.; Hirohata, Y.; Yamashina, T.

    1997-02-01

    In a fusion reactor, the continuous removal of helium from the core plasma is needed in order to sustain the ignition condition. For this purpose, it has been proposed to place helium selective pumping metals, which can trap more helium than hydrogen, in the vicinity of the divertor. In this study, the helium and hydrogen trapping properties of nickel, tungsten, molybdenum, SS 304 and Inconel 625 were examined. Namely, the dependencies of irradiation temperature on the amount of trapped helium and hydrogen were obtained by thermal desorption spectroscopy (TDS), after helium or hydrogen plasma irradiation. In those metals, nickel showed the most suitable selective pumping capability. Nickel had the helium selective pumping property above 100°C. The maximum amount of trapped helium was (2-3) × 10 16He/ cm2 at an irradiation temperature of 200°C and 600°C. The optimum temperature becomes about 600°C when nickel is used for a selective pumping material.

  15. Strain weakening and localisation: material properties or boundary effects?

    NASA Astrophysics Data System (ADS)

    Ritter, Malte C.; Leever, Karen; Rosenau, Matthias; Oncken, Onno

    2015-04-01

    Strain weakening is commonly seen as one of the major causes of localisation of deformation into shear zones in brittle media. Several studies, both numerical and physical experiments, investigate its influence. Typically, these studies choose a certain model configuration and test various material properties and their influence on localisation in that particular configuration. This approach, however, does not take into account the fundamental importance of boundary conditions on the processes of localisation, weakening and overall shear zone evolution. To address this issue, we perform physical experiments in granular materials. We create shear fractures within a sample of granular material (sand) using different experimental apparatuses that apply different boundary conditions. Among them are standard machines such as a Ring-Shear Tester and the classical Riedel set up, as well as a newly designed set up. Boundary conditions can be varied from purely kinematic to more dynamically controlled and from laterally confined to unconfined. Nevertheless, the final result of deformation is an approximately straight strike-slip shear zone in all cases. We monitor boundary force (i. e. material strength) and, where experimentally accessible, strain, at high temporal resolution during deformation. With our different set ups we are able to produce very different patterns of deformation and weakening in the same material under the same constant rate of shearing and with the same final result. Observed patterns span from nearly instantaneous formation of one single through-going shear zone to slow, step-wise growth of a complex network of interacting cracks. Weakening in all cases matches well the structural evolution. Variations of weakening for a given material in different set ups are larger than for different materials in a given set up. Our results show that for a given material the style and rate of localisation can change drastically, depending on only slight changes of

  16. Quantum Dots: An Experiment for Physical or Materials Chemistry

    ERIC Educational Resources Information Center

    Winkler, L. D.; Arceo, J. F.; Hughes, W. C.; DeGraff, B. A.; Augustine, B. H.

    2005-01-01

    An experiment is conducted for obtaining quantum dots for physical or materials chemistry. This experiment serves to both reinforce the basic concept of quantum confinement and providing a useful bridge between the molecular and solid-state world.

  17. Distributional properties of stochastic shortest paths for smuggled nuclear material

    SciTech Connect

    Cuellar, Leticia; Pan, Feng; Roach, Fred; Saeger, Kevin J

    2011-01-05

    The shortest path problem on a network with fixed weights is a well studied problem with applications to many diverse areas such as transportation and telecommunications. We are particularly interested in the scenario where a nuclear material smuggler tries to succesfully reach herlhis target by identifying the most likely path to the target. The identification of the path relies on reliabilities (weights) associated with each link and node in a multi-modal transportation network. In order to account for the adversary's uncertainty and to perform sensitivity analysis we introduce random reliabilities. We perform some controlled experiments on the grid and present the distributional properties of the resulting stochastic shortest paths.

  18. Mechanics of Granular Materials (MGM) Microgravity Experiment

    NASA Technical Reports Server (NTRS)

    Alshibli, Khalid A.; Sture, Stein

    1998-01-01

    The second series of MGM experiment was conducted during the STS-89 mission in January 1998. The experiment was previously flow on Atlantis's STS-79 mission in September 1996. Six displacement-controlled, drained triaxial compression experiments were performed at very low effective confining stresses. The confining stresses were in the ranges 0.05, 0.52 and 1.30 kPa. Three experiments were subjected to monotonic loading and unloading cycles while the other three experiments were subjected to cyclic loading. The results show very high peak strength friction angles in the range of 47.6 to 70.0 degrees, which are mainly due to overconsolidation and grain interlocking effects. It was observed that the residual strength levels in the monotonic loading experiments were in the same range as that observed at higher confining stress levels. The dilatancy angles were unusually high in the range of 30 to 31 degrees. All specimens display substantial initial stiffnesses and elastic moduli during unloading and reloading events, which are nearly an order of magnitude higher than conventional theories predict. A periodic instability phenomenon which appears to result from buckling of multiple internal arches and columnar systems, augmented by stick-slips was observed in the experiments. Computed Tomography (CT) measurements revealed valuable data about the internal fabric and the specimens deformation patterns. Uniform diffuse bifurcation with multiple radial shear bands was observed in the specimens tested in a microgravity environment. In the axial direction, two major conical surfaces were developed. Spatial nonsymmetrical deformations were observed in specimens tested in terrestrial laboratory.

  19. 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

  20. Temporal properties of material categorization and material rating: visual vs non-visual material features.

    PubMed

    Nagai, Takehiro; Matsushima, Toshiki; Koida, Kowa; Tani, Yusuke; Kitazaki, Michiteru; Nakauchi, Shigeki

    2015-10-01

    Humans can visually recognize material categories of objects, such as glass, stone, and plastic, easily. However, little is known about the kinds of surface quality features that contribute to such material class recognition. In this paper, we examine the relationship between perceptual surface features and material category discrimination performance for pictures of materials, focusing on temporal aspects, including reaction time and effects of stimulus duration. The stimuli were pictures of objects with an identical shape but made of different materials that could be categorized into seven classes (glass, plastic, metal, stone, wood, leather, and fabric). In a pre-experiment, observers rated the pictures on nine surface features, including visual (e.g., glossiness and transparency) and non-visual features (e.g., heaviness and warmness), on a 7-point scale. In the main experiments, observers judged whether two simultaneously presented pictures were classified as the same or different material category. Reaction times and effects of stimulus duration were measured. The results showed that visual feature ratings were correlated with material discrimination performance for short reaction times or short stimulus durations, while non-visual feature ratings were correlated only with performance for long reaction times or long stimulus durations. These results suggest that the mechanisms underlying visual and non-visual feature processing may differ in terms of processing time, although the cause is unclear. Visual surface features may mainly contribute to material recognition in daily life, while non-visual features may contribute only weakly, if at all. PMID:25536464

  1. Asteroid Regolith Mechanical Properties: Laboratory Experiments With Cohesive Powders

    NASA Astrophysics Data System (ADS)

    Durda, Daniel D.; Scheeres, D. J.; Roark, S. E.; Dissly, R.; Sanchez, P.

    2012-10-01

    Despite clear evidence that small asteroids undergo drastic physical evolution, the geophysics and mechanics of many of the processes governing that evolution remain a mystery due to a lack of scientific data, both on the sub-surface and global geophysics of these small bodies and on the mechanical properties of regoliths in the unique micro-gravity regime they inhabit. We are beginning a three-year effort to study regolith properties and processes on low-gravity, small asteroids by conducting analog experiments with cohesive powders in a 1-g laboratory environment. Based on a rigorous comparison of forces it can be shown that van der Waals cohesive forces between millimeter to centimeter-sized grains on asteroids ranging in size from Eros to Itokawa, respectively, may exceed their ambient weight several-fold. This observation implies that regoliths composed of impact debris of those sizes should behave on the microgravity surfaces of small asteroids like flour or other cohesive powders do in the 1-g environment here on Earth. Our goal is to develop an improved understanding of the role of cohesion in affecting regolith processes and surface morphology of small Solar System bodies, some the targets of ongoing and proposed NASA New Frontiers and Discovery missions, and to quantify the range of expected mechanical properties of such regoliths. Our experiments will be conducted in ambient and vacuum conditions within an environmental test chamber at Ball Aerospace & Technologies Corporation (BATC) in Boulder, CO. To aid in validating our experiment chamber and support equipment performance, and before proceeding with experiments on geologic regolith simulant materials, we will perform a series of comparative, ‘calibration’ experiments with micro glass spheres; all primary experiments will be performed with at least one non-idealized regolith simulant, like JSC-1, that more realistically simulates the angular particle shapes expected in actual geologic fragments

  2. Properties of materials using acoustic waves

    NASA Astrophysics Data System (ADS)

    Apfel, R. E.

    1984-10-01

    Our goal of characterizing materials using acoustic waves was forwarded through a number of projects: (1) We have refined our modulated radiation pressure technique for characterizing the interfaces between liquids so that we can automatically track changes in interfacial tension over time due to contaminants, surfactants, etc. (2) We have improved and simplified our acoustic scattering apparatus for measuring distributions of the properties of microparticle samples, which will allow us to distinguish particulates in liquids by size, compressibility, and density. (3) We are continuing work on theoretical approaches to nonlinear acoustics which should permit us to cast problems with geometric and other complexities into a manageable form. (4) Our studies of cavitation have enabled us to derive an analytic expression which predicts the acoustic pressure threshold for cavitation at the micrometer scale - where surface tension effects are important. This work has relevance to the consideration of possible bioeffects from diagnostic ultrasound. (5) Other projects include the calibration of hydrophones using acoustically levitated samples, and the investigation of solitary waves of the sort discovered by Wu, Keolian and Rudnick.

  3. Factors Influencing the Dielectric Properties of Agricultural and Food Materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dielectric properties of materials are defined, and the major factors that influence these properties of agricultural and food materials, namely, frequency of the applied radio-frequency or microwave electric fields, and water content, temperature, and density of the materials, are discussed on the ...

  4. Materials experience in methanol reforming units

    SciTech Connect

    Baumert, K.L.; Hoffman, J.J.

    1997-09-01

    Metallurgical evaluations were performed on samples of Type 310 and aluminized 304 SS after long-term, high temperature exposure in methanol reforming service. The secondary phases were identified and the effectiveness of aluminizing at inhibiting metal dusting was examined. Secondary phases adversely affect the materials service life and repairability. Aluminizing effectively inhibits metal dusting for at least 13--14 years. Metal dusting is most severe in crevices on bare metal.

  5. Structures and properties of materials recovered from high shock pressures

    SciTech Connect

    Nellis, W.J.

    1994-03-01

    Shock compression produces high dynamic pressures, densities, temperatures, and their quench rates. Because of these extreme conditions, shock compression produces materials with novel crystal structures, microstructures, and physical properties. Using a 6.5-m-long two-stage gun, we perform experiments with specimens up to 10 mm in diameter and 0.001--1 mm thick. For example, oriented disks of melt-textured superconducting YBa{sub 2}Cu{sub 3}O{sub 7} were shocked to 7 GPa without macroscopic fracture. Lattice defects are deposited in the crystal, which improve magnetic hysteresis at {approximately}1 kOe. A computer code has been developed to simulate shock compaction of 100 powder particles. Computations will be compared with experiments with 15--20 {mu}m Cu powders. The method is applicable to other powders and dynamic conditions.

  6. Process modelling for materials preparation experiments

    NASA Technical Reports Server (NTRS)

    Rosenberger, Franz; Alexander, J. Iwan D.

    1993-01-01

    The main goals of the research under this grant consist of the development of mathematical tools and measurement of transport properties necessary for high fidelity modeling of crystal growth from the melt and solution, in particular, for the Bridgman-Stockbarger growth of mercury cadmium telluride (MCT) and the solution growth of triglycine sulphate (TGS). Of the tasks described in detail in the original proposal, two remain to be worked on: (1) development of a spectral code for moving boundary problems; and (2) diffusivity measurements on concentrated and supersaturated TGS solutions. Progress made during this seventh half-year period is reported.

  7. Process modelling for materials preparation experiments

    NASA Technical Reports Server (NTRS)

    Rosenberger, Franz; Alexander, J. Iwan D.

    1993-01-01

    The main goals of the research consist of the development of mathematical tools and measurement of transport properties necessary for high fidelity modeling of crystal growth from the melt and solution, in particular for the Bridgman-Stockbarger growth of mercury cadmium telluride (MCT) and the solution growth of triglycine sulphate (TGS). Of the tasks described in detail in the original proposal, two remain to be worked on: development of a spectral code for moving boundary problems, and diffusivity measurements on concentrated and supersaturated TGS solutions. During this eighth half-year period, good progress was made on these tasks.

  8. Process modelling for materials preparation experiments

    NASA Technical Reports Server (NTRS)

    Rosenberger, Franz; Alexander, J. Iwan D.

    1992-01-01

    The development is examined of mathematical tools and measurement of transport properties necessary for high fidelity modeling of crystal growth from the melt and solution, in particular for the Bridgman-Stockbarger growth of mercury cadmium telluride (MCT) and the solution growth of triglycine sulphate (TGS). The tasks include development of a spectral code for moving boundary problems, kinematic viscosity measurements on liquid MCT at temperatures close to the melting point, and diffusivity measurements on concentrated and supersaturated TGS solutions. A detailed description is given of the work performed for these tasks, together with a summary of the resulting publications and presentations.

  9. The Magnetic Properties Experiments on Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Knudsen, J. M.; Gunnlaugsson, H. P.; Hviid, S. F.; Madsen, M. B.

    1996-09-01

    A remarkable result from the Viking missions was the discovery that the Martian soil is highly magnetic, in the sense that the soil is attracted by permanent magnets. Both the strong and weak magnets on the Viking landers were saturated with dust throughout the mission. Appropriate limits for the spontaneous magnetization sigma_S were advanced: 1 Am(2) (kg soil)(-1) < sigma_S < 7 Am(2) (kg soil)(-1) . The essential difference between the Magnet Arrays for Mars Pathfinder and the Viking Magnetic Properties Experiment is that Magnet Arrays on Pathfinder will include magnets of lower strengths that the weakest Viking magnet. The five magnets consist of small ring magnets concentric with oppositely polarized cylindrical magnets. The outer diameter of the ring magnets is 18 mm. Discrete (single phase) particles of strongly magnetic minerals (gamma -Fe2O3 or Fe3O4) will stick to all five magnets, while composite (multiphase) particles will stick preferentially to the strongest magnets. Two Magnet Arrays are placed on the Pathfinder lander, with a distance of 1180 and 1450 mm, respectively, from the Imager for Mars Pathfinder (IMP). The magnets will attract airborne dust, and the dust on the magnets will be periodically viewed by the IMP. The images transmitted to Earth are the data on which conclusions on the magnetic properties of the dust will be based. Besides the Magnet Arrays the Pathfinder lander carries two other types of magnets. The Tip Plate Magnet is placed at a distance of 10 cm from the IMP, and thus allows a rather high resolution imaging of the dust clinging to the magnet. The Ramp Magnets are placed near the end of the ramps by which the micro-rover will descend to the surface. The dust on the Ramp Magnets will be studied by the APX-spectrometer of the micro-rover.

  10. Mechanical properties of irradiated multi-phase polycrystalline BCC materials

    NASA Astrophysics Data System (ADS)

    Song, Dingkun; Xiao, Xiazi; Xue, Jianming; Chu, Haijian; Duan, Huiling

    2015-04-01

    Structure materials under severe irradiations in nuclear environments are known to degrade because of irradiation hardening and loss of ductility, resulting from irradiation-induced defects such as vacancies, interstitials and dislocation loops, etc. In this paper, we develop an elastic-viscoplastic model for irradiated multi-phase polycrystalline BCC materials in which the mechanical behaviors of individual grains and polycrystalline aggregates are both explored. At the microscopic grain scale, we use the internal variable model and propose a new tensorial damage descriptor to represent the geometry character of the defect loop, which facilitates the analysis of the defect loop evolutions and dislocation-defect interactions. At the macroscopic polycrystal scale, the self-consistent scheme is extended to consider the multiphase problem and used to bridge the individual grain behavior to polycrystal properties. Based on the proposed model, we found that the work-hardening coefficient decreases with the increase of irradiation-induced defect loops, and the orientation/loading dependence of mechanical properties is mainly attributed to the different Schmid factors. At the polycrystalline scale, numerical results for pure Fe match well with the irradiation experiment data. The model is further extended to predict the hardening effect of dispersoids in oxide-dispersed strengthened steels by the considering the Orowan bowing. The influences of grain size and irradiation are found to compete to dominate the strengthening behaviors of materials.

  11. Learning to apply models of materials while explaining their properties

    NASA Astrophysics Data System (ADS)

    Karpin, Tiia; Juuti, Kalle; Lavonen, Jari

    2014-09-01

    Background:Applying structural models is important to chemistry education at the upper secondary level, but it is considered one of the most difficult topics to learn. Purpose:This study analyses to what extent in designed lessons students learned to apply structural models in explaining the properties and behaviours of various materials. Sample:An experimental group is 27 Finnish upper secondary school students and control group included 18 students from the same school. Design and methods:In quasi-experimental setting, students were guided through predict, observe, explain activities in four practical work situations. It was intended that the structural models would encourage students to learn how to identify and apply appropriate models when predicting and explaining situations. The lessons, organised over a one-week period, began with a teacher's demonstration and continued with student experiments in which they described the properties and behaviours of six household products representing three different materials. Results:Most students in the experimental group learned to apply the models correctly, as demonstrated by post-test scores that were significantly higher than pre-test scores. The control group showed no significant difference between pre- and post-test scores. Conclusions:The findings indicate that the intervention where students engage in predict, observe, explain activities while several materials and models are confronted at the same time, had a positive effect on learning outcomes.

  12. Determination of Thermal Properties of Composting Bulking Materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermal properties of compost bulking materials affect temperature and biodegradation during the composting process. Well determined thermal properties of compost feedstocks will therefore contribute to practical thermodynamic approaches. Thermal conductivity, thermal diffusivity, and volumetric hea...

  13. Determination of Thermal Properties of Composting Bulking Materials

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermal properties of compost bulking materials affect temperature and biodegradation during the composting process. Well-determined thermal properties of compost feedstocks will therefore contribute to practical thermodynamic approaches. Thermal conductivity, thermal diffusivity, and volumetric hea...

  14. Process modelling for materials preparation experiments

    NASA Technical Reports Server (NTRS)

    Rosenberger, Franz; Alexander, J. Iwan D.

    1994-01-01

    The main goals of the research under this grant consist of the development of mathematical tools and measurement techniques for transport properties necessary for high fidelity modelling of crystal growth from the melt and solution. Of the tasks described in detail in the original proposal, two remain to be worked on: development of a spectral code for moving boundary problems, and development of an expedient diffusivity measurement technique for concentrated and supersaturated solutions. We have focused on developing a code to solve for interface shape, heat and species transport during directional solidification. The work involved the computation of heat, mass and momentum transfer during Bridgman-Stockbarger solidification of compound semiconductors. Domain decomposition techniques and preconditioning methods were used in conjunction with Chebyshev spectral methods to accelerate convergence while retaining the high-order spectral accuracy. During the report period we have further improved our experimental setup. These improvements include: temperature control of the measurement cell to 0.1 C between 10 and 60 C; enclosure of the optical measurement path outside the ZYGO interferometer in a metal housing that is temperature controlled to the same temperature setting as the measurement cell; simultaneous dispensing and partial removal of the lower concentration (lighter) solution above the higher concentration (heavier) solution through independently motor-driven syringes; three-fold increase in data resolution by orientation of the interferometer with respect to diffusion direction; and increase of the optical path length in the solution cell to 12 mm.

  15. Shocked materials at the intersection of experiment and simulation

    SciTech Connect

    Lorenzana, H. E.; Belak, J. F.; Bradley, K. S.; Bringa, E. M.; Budil, K. S.; Cazamias, J. U.; El-Dasher, B.; Hawreliak, J. A.; Hessler, J.; Kadau, K.; Kalantar, D. H.; McNaney, J. M.; Milathianaki, D.; Rosolankova, K.; Swift, D. C.; Taravillo, M.; Van Buuren, T. W.; Wark, J. S.; de la Rubia, T. Diaz

    2008-04-01

    Understanding the dynamic lattice response of solids under the extreme conditions of pressure, temperature and strain rate is a scientific quest that spans nearly a century. Critical to developing this understanding is the ability to probe and model the spatial and temporal evolution of the material microstructure and properties at the scale of the relevant physical phenomena-nanometers to micrometers and picoseconds to nanoseconds. While experimental investigations over this range of spatial and temporal scales were unimaginable just a decade ago, new technologies and facilities currently under development and on the horizon have brought these goals within reach for the first time. The equivalent advancements in simulation capabilities now mean that we can conduct simulations and experiments at overlapping temporal and spatial scales. In this article, we describe some of our studies which exploit existing and new generation ultrabright, ultrafast x-ray sources and large scale molecular dynamics simulations to investigate the real-time physical phenomena that control the dynamic response of shocked materials.

  16. Shocked materials at the intersection of experiment and simulation

    SciTech Connect

    Kadau, Kai

    2008-01-01

    Understanding the dynamic lattice response of solids under the extreme conditions of pressure, temperature and strain rate is a scientific quest that spans nearly a century. Critical to developing this understanding is the ability to probe and model the spatial and temporal evolution of the material microstructure and properties at the scale of the relevant physical phenomena -- nanometers to micrometers and picoseconds to nanoseconds. While experimental investigations over this range of spatial and temporal scales were unimaginable just a decade ago, new technologies and facilities currently under development and on the horizon have brought these goals within reach for the first time. The equivalent advancements in simulation capabilities now mean that we can conduct simulations and experiments at overlapping temporal and spatial scales. In this article, we describe some of our studies which exploit existing and new generation ultrabright, ultrafast x-ray sources and large scale molecular dynamics simulations to investigate the real-time physical phenomena that control the dynamic response of shocked materials.

  17. Graphite as a plasma-facing material in fusion experiments

    SciTech Connect

    Langley, R.A. )

    1989-01-01

    Graphite is now used extensively in most of the major fusion experiments in the world and will be used more extensively in future devices. In addition to its excellent tolerance of high heat fluxes, graphite has many unusual characteristics that pertain to its use as a plasma-facing material; these are its propensity for releasing gases when heated and when exposed to ion fluxes, its ability to absorb copious quantities of hydrogen during hydrogen bombardment, and its ability to pump hydrogen after noble gas bombardment. The graphite used in existing machines and considered for use in future machines is isotropic on a macroscopic scale and anisotropic on a microscopic scale; it has a large open porosity, up to 20%. This leads to enormous internal surface areas for adsorption and desorption of gases. Most early hydrogen-graphite interaction experiments were incorrectly analyzed because of this property. In addition, interaction of energetic hydrogen ions with graphite can lead to erosion, with concomitant deposition of carbon films with high hydrogen content on chamber surfaces. These effects are observed experimentally and have been modeled with some success. This paper presents experimental data dealing with these topics and their influences on present-day plasma operations and on graphite use in future machines. 34 refs., 8 figs., 1 tab.

  18. Materials Adherence Experiment on Mars Pathfinder: Early results

    SciTech Connect

    Landis, G.A.; Jenkins, P.P.; Hunter, G.

    1997-12-31

    The Materials Adherence Experiment (MAE) on the Pathfinder Sojourner rover will measure the dust deposition rate. By August, the Sojourner Rover on Mars Pathfinder will have completed its primary mission, and the experiment will have data on dust deposition during the first three weeks of operation on Mars. This paper will present the initial data from the experiment. This will be the first presentation of the results from the Pathfinder MAE experiment.

  19. 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

  20. 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

  1. 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

  2. Absorption properties of waste matrix materials

    SciTech Connect

    Briggs, J.B.

    1997-06-01

    This paper very briefly discusses the need for studies of the limiting critical concentration of radioactive waste matrix materials. Calculated limiting critical concentration values for some common waste materials are listed. However, for systems containing large quantities of waste materials, differences up to 10% in calculated k{sub eff} values are obtained by changing cross section data sets. Therefore, experimental results are needed to compare with calculation results for resolving these differences and establishing realistic biases.

  3. Studies of molecular properties of polymeric materials

    NASA Technical Reports Server (NTRS)

    Harries, W. L.; Long, Sheila Ann T.; Long, Edward R., Jr.

    1990-01-01

    Aerospace environment effects (high energy electrons, thermal cycling, atomic oxygen, and aircraft fluids) on polymeric and composite materials considered for structural use in spacecraft and advanced aircraft are examined. These materials include Mylar, Ultem, and Kapton. In addition to providing information on the behavior of the materials, attempts are made to relate the measurements to the molecular processes occurring in the material. A summary and overview of the technical aspects are given along with a list of the papers that resulted from the studies. The actual papers are included in the appendices and a glossary of technical terms and definitions is included in the front matter.

  4. Metallurgy and properties of plasma spray formed materials

    NASA Technical Reports Server (NTRS)

    Mckechnie, T. N.; Liaw, Y. K.; Zimmerman, F. R.; Poorman, R. M.

    1992-01-01

    Understanding the fundamental metallurgy of vacuum plasma spray formed materials is the key to enhancing and developing full material properties. Investigations have shown that the microstructure of plasma sprayed materials must evolve from a powder splat morphology to a recrystallized grain structure to assure high strength and ductility. A fully, or near fully, dense material that exhibits a powder splat morphology will perform as a brittle material compared to a recrystallized grain structure for the same amount of porosity. Metallurgy and material properties of nickel, iron, and copper base alloys will be presented and correlated to microstructure.

  5. Skylab experiment performance evaluation manual. Appendix E: Experiment M512 Materials processing facility (MSFC)

    NASA Technical Reports Server (NTRS)

    Thomas, O. H., Jr.

    1973-01-01

    Analyses for Experiment M512, Materials Processing Facility (MSFC), to be used for evaluating the performance of the Skylab corollary experiments under preflight, inflight, and post-flight conditions are presented. Experiment contingency plan workaround procedure and malfunction analyses are presented in order to assist in making the experiment operationally successful.

  6. Dielectric properties of agricultural materials and their application

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This book is prepared as a comprehensive source of information on dielectric properties of agricultural materials for scientific researchers and engineers involved in practical application of radio-frequency and microwave energy for potential problem solutions. Dielectric properties of materials det...

  7. NDE Elastic Properties of Fiber-Reinforced Composite Materials

    NASA Technical Reports Server (NTRS)

    Bar-Cohen, Y.

    1995-01-01

    Fiber-reinforced composites are increasingly replacing metallic alloys as structural materials for primary components of fracture-critical structures. This trend is a result of the growing understanding of material behavior and recognition of the desirable properties of composites. A research program was conducted on NDE methods for determining the elastic properties of composites.

  8. Analysis of Photothermal Characterization of Layered Materials: Design of Optimal Experiments

    NASA Technical Reports Server (NTRS)

    Cole, Kevin D.

    2003-01-01

    In this paper numerical calculations are presented for the steady-periodic temperature in layered materials and functionally-graded materials to simulate photothermal methods for the measurement of thermal properties. No laboratory experiments were performed. The temperature is found from a new Green s function formulation which is particularly well-suited to machine calculation. The simulation method is verified by comparison with literature data for a layered material. The method is applied to a class of two-component functionally-graded materials and results for temperature and sensitivity coefficients are presented. An optimality criterion, based on the sensitivity coefficients, is used for choosing what experimental conditions will be needed for photothermal measurements to determine the spatial distribution of thermal properties. This method for optimal experiment design is completely general and may be applied to any photothermal technique and to any functionally-graded material.

  9. Dynamic material properties of refractory materials: Tantalum and tantalum/tungsten alloys

    SciTech Connect

    Furnish, M.D.; Chhabildas, L.C.; Lassila, D.H.; Steinberg, D.J.

    1995-08-01

    We have made a careful set of impact wave-profile measurements (16 profiles) on tantalum and tantalum-tungsten alloys at relatively low stresses (to 15 GPa). Alloys used were Ta{sub 97.5}W{sub 2.5} and Ta{sub 90}W{sub 10} (wt. %) with oxygen contents of 30--70 ppM. Information available from these experiments includes Hugoniot, elastic limits, loading fates, spall strength, unloading paths, reshock structure and specimen thickness effects. Hugoniot and spall properties are illustrated, and are consistent with expectations from earlier work. Modeling the tests with the Steinberg-Lund rate-dependent material model provides for an excellent match of the shape of the plastic wave, although the release wave is not well modeled. There is also a discrepancy between experiments and calculations regarding the relative timing of the elastic and plastic waves that may be due to texture effects.

  10. Photoacoustic characterization of the mechanical properties of thin film materials

    NASA Astrophysics Data System (ADS)

    Zhang, Feifei; Krishnaswamy, Sridhar; Fei, Dong; Rebinsky, Douglas A.

    2005-05-01

    Two high frequency photoacoustic techniques were applied to investigate the mechanical properties of two sets of thin film materials in this work. Broadband photoacoustic guided-wave method was used to measure the guided-wave phase velocity dispersion curves of nano-structured diamond-like carbon hard coatings. The experimental velocity spectra were analyzed by a nonlinear optimization approach in conjunction with a multi-layer wave-propagation model. The derived Young"s moduli using the broadband photoacoustic technique were compared with line-focus acoustic microscopy and nano-indentation tests and good quantitative agreement is found. In a second set of experiments, ultra-thin two-layer aluminum and silicon nitride thin film materials were tested using the femtosecond transient pump-probe method using high frequency bulk waves generated by the ultra-fast laser pulses. The measured moduli of silicon nitride thin layers are in the range of 270 - 340 GPa. Photoacoustic methods are shown to be suitable for in-situ and non-destructive evaluation of the mechanical properties of thin films.

  11. Structure and Thermal Properties of Porous Geological Materials

    NASA Astrophysics Data System (ADS)

    Kirk, Simon; Williamson, David

    2011-06-01

    Understanding the behaviour of porous geological materials is important for developing models of the explosive loading of rock in mining applications. To this end it is essential to first characterise its complex internal structure. Knowing the structure shows how the properties of the component materials relate to the overall properties of rock. The structure and mineralogy of Gosford sandstone was investigated and this information was used to predict its thermal properties. The thermal properties of the material were measured experimentally and compared against these predictions.

  12. Exposure effects on the optical properties of building materials

    NASA Astrophysics Data System (ADS)

    Lane, Sarah; Cathcart, J. Michael; Harrell, J. Timothy

    2008-04-01

    Georgia Tech recently initiated a weathering effects measurement program to monitor the optical properties of several common building materials. A set of common building materials were placed outdoors and optical property measurements made over a series of weeks to assess the impact of exposure on these properties. Both reflectivity and emissivity measurements were made. Materials in this program included aluminum flashing, plastic sheets, bricks, roof shingles, and tarps. This paper will discuss the measurement approach, experimental setup, and present preliminary results from the optical property measurements.

  13. Neutron irradiation experiments for fusion reactor materials through JUPITER program

    NASA Astrophysics Data System (ADS)

    Abe, K.; Kohyama, A.; Namba, C.; Wiffen, F. W.; Jones, R. H.

    1998-10-01

    A Japan-USA Program of irradiation experiments for fusion research, "JUPITER", has been established as a 6 year program from 1995 to 2000. The goal is to study "the dynamic behavior of fusion reactor materials and their response to variable and complex irradiation environment". This is phase-three of the collaborative program, which follows RTNS-II Program (Phase-1: 1982-1986) and FFTF/MOTA Program (Phase-2: 1987-1994). This program is to provide a scientific basis for application of materials performance data, generated by fission reactor experiments, to anticipated fusion environments. Following the systematic study on cumulative irradiation effects, done through FFTF/MOTA Program, JUPITER is emphasizing the importance of dynamic irradiation effects on materials performance in fusion systems. The irradiation experiments in this program include low activation structural materials, functional ceramics and other innovative materials. The experimental data are analyzed by theoretical modeling and computer simulation to integrate the above effects.

  14. Calculation of material properties and ray tracing in transformation media.

    PubMed

    Schurig, D; Pendry, J B; Smith, D R

    2006-10-16

    Complex and interesting electromagnetic behavior can be found in spaces with non-flat topology. When considering the properties of an electromagnetic medium under an arbitrary coordinate transformation an alternative interpretation presents itself. The transformed material property tensors may be interpreted as a different set of material properties in a flat, Cartesian space. We describe the calculation of these material properties for coordinate transformations that describe spaces with spherical or cylindrical holes in them. The resulting material properties can then implement invisibility cloaks in flat space. We also describe a method for performing geometric ray tracing in these materials which are both inhomogeneous and anisotropic in their electric permittivity and magnetic permeability. PMID:19529371

  15. "TPSX: Thermal Protection System Expert and Material Property Database"

    NASA Technical Reports Server (NTRS)

    Squire, Thomas H.; Milos, Frank S.; Rasky, Daniel J. (Technical Monitor)

    1997-01-01

    The Thermal Protection Branch at NASA Ames Research Center has developed a computer program for storing, organizing, and accessing information about thermal protection materials. The program, called Thermal Protection Systems Expert and Material Property Database, or TPSX, is available for the Microsoft Windows operating system. An "on-line" version is also accessible on the World Wide Web. TPSX is designed to be a high-quality source for TPS material properties presented in a convenient, easily accessible form for use by engineers and researchers in the field of high-speed vehicle design. Data can be displayed and printed in several formats. An information window displays a brief description of the material with properties at standard pressure and temperature. A spread sheet window displays complete, detailed property information. Properties which are a function of temperature and/or pressure can be displayed as graphs. In any display the data can be converted from English to SI units with the click of a button. Two material databases included with TPSX are: 1) materials used and/or developed by the Thermal Protection Branch at NASA Ames Research Center, and 2) a database compiled by NASA Johnson Space Center 9JSC). The Ames database contains over 60 advanced TPS materials including flexible blankets, rigid ceramic tiles, and ultra-high temperature ceramics. The JSC database contains over 130 insulative and structural materials. The Ames database is periodically updated and expanded as required to include newly developed materials and material property refinements.

  16. An Experiment to Tame the Plasma Material Interface

    SciTech Connect

    Goldston, R J; Menard, J E; Allain, J P; Brooks, J N; Canik, J M; Doerner, R; Fu, G; Gates, D A; Gentile, C A; Harris, J H; Hassanein, A; Gorelenkov, N N; Kaita, R; Kaye, S M; Kotschenreuther, M; Kramer, G J; Kugel, H W; Maingi, R; Mahajan, S M; Majeski, R; Neumeyer, C L; Nygren, R E; Ono, M; Owen, L W; Ramakrishnan, S; Rognlien, T D; Ruzic, D N; Ryutov, D D; Sabbagh, S A; Skinner, C H; Soukhanovskii, V A; Stevenson, T N; Ulrickson, M A; Valanju, P M; Woolley, R D

    2009-01-08

    The plasma material interface in Demo will be more challenging than that in ITER, due to requirements for approximately four times higher heat flux from the plasma and approximately five times higher average duty factor. The scientific and technological solutions employed in ITER may not extrapolate to Demo. The key questions to be resolved for Demo and the resulting key requirements for an experiment to 'tame the plasma material interface' are analyzed. A possible design point for such an experiment is outlined.

  17. Interfacial properties and design of functional energy materials.

    PubMed

    Sumpter, Bobby G; Liang, Liangbo; Nicolaï, Adrien; Meunier, Vincent

    2014-11-18

    CONSPECTUS: The vital importance of energy to society continues to demand a relentless pursuit of energy responsive materials that can bridge fundamental chemical structures at the molecular level and achieve improved functionality and performance. This demand can potentially be realized by harnessing the power of self-assembly, a spontaneous process where molecules or much larger entities form ordered aggregates as a consequence of predominately noncovalent (weak) interactions. Self-assembly is the key to bottom-up design of molecular devices, because the nearly atomic-level control is very difficult to realize in a top-down, for example, lithographic, approach. However, while function in simple systems such as single crystals can often be evaluated a priori, predicting the function of the great variety of self-assembled molecular architectures is complicated by the lack of understanding and control over nanoscale interactions, mesoscale architectures, and macroscale order. To establish a foundation toward delivering practical solutions, it is critical to develop an understanding of the chemical and physical mechanisms responsible for the self-assembly of molecular and hybrid materials on various support substrates. Typical molecular self-assembly involves noncovalent intermolecular and substrate-molecule interactions. These interactions remain poorly understood, due to the combination of many-body interactions compounded by local or collective influences from the substrate atomic lattice and electronic structure. Progress toward unraveling the underlying physicochemical processes that control the structure and macroscopic physical, chemical, mechanical, electrical, and transport properties of materials increasingly requires tight integration of theory, modeling, and simulation with precision synthesis, advanced experimental characterization, and device measurements. Theory, modeling, and simulation can accelerate the process of materials understanding and design

  18. Electronic correlation and transport properties of nuclear fuel materials

    SciTech Connect

    Yin Quan; Kutepov, Andrey; Haule, Kristjan; Kotliar, Gabriel; Savrasov, Sergey Y.; Pickett, Warren E.

    2011-11-15

    The electronic structures and transport properties of a series of actinide monocarbides, mononitrides, and dioxides are studied systematically using a combination of density-functional theory and dynamical mean-field theory. The studied materials present different electronic correlation strength and degree of localization of 5f electrons, where a metal-insulator boundary naturally lies within. In the spectral function of Mott-insulating uranium oxide, a resonance peak is observed in both theory and experiment and may be understood as a generalized Zhang-Rice state. We also investigate the interplay between electron-electron and electron-phonon interactions, both of which are responsible for the transport in the metallic compounds. Our findings allow us to gain insight in the roles played by different scattering mechanisms, and suggest how to improve their thermal conductivities.

  19. Determination of the properties of viscoelastic materials using spherical nanoindentation

    NASA Astrophysics Data System (ADS)

    Martynova, Elena

    2016-02-01

    The article is devoted to determining the properties of linearly viscoelastic isotropic materials from the experiment on the introduction of a spherical indenter at a constant-rate displacement in a viscoelastic sample. The results are based on the Lee-Radok (J. Appl. Mech. 27:438-444, 1960) solution of the viscoelastic contact problem. An exact formula is obtained for calculation of the relaxation function using indentation load-displacement data. To illustrate the application of this formula, it is used to find the relaxation function of polymethyl methacrylate (PMMA). The relaxation function found in the article is compared with data measured in a conventional test to evaluate the suitability of the proposed method.

  20. Electronic correlation and transport properties of nuclear fuel materials

    NASA Astrophysics Data System (ADS)

    Yin, Quan; Kutepov, Andrey; Haule, Kristjan; Kotliar, Gabriel; Savrasov, Sergey Y.; Pickett, Warren E.

    2011-11-01

    The electronic structures and transport properties of a series of actinide monocarbides, mononitrides, and dioxides are studied systematically using a combination of density-functional theory and dynamical mean-field theory. The studied materials present different electronic correlation strength and degree of localization of 5f electrons, where a metal-insulator boundary naturally lies within. In the spectral function of Mott-insulating uranium oxide, a resonance peak is observed in both theory and experiment and may be understood as a generalized Zhang-Rice state. We also investigate the interplay between electron-electron and electron-phonon interactions, both of which are responsible for the transport in the metallic compounds. Our findings allow us to gain insight in the roles played by different scattering mechanisms, and suggest how to improve their thermal conductivities.

  1. Concepts and techniques for ultrasonic evaluation of material mechanical properties

    NASA Technical Reports Server (NTRS)

    Vary, A.

    1980-01-01

    The ultrasonic nondestructive evaluation techniques discussed in the present paper indicate potentials for material characterization and property prediction. Stress wave interaction and material transfer function concepts are examined as a basis for explaining correlations between material mechanical behavior and ultrasonically measured quantities. It is observed that the effect and criticality of any discrete flaw, such as crack, inclusion, or any other stress raiser, is definable only in terms of its material microstructural environment. This underscores the importance of ultrasonic techniques capable of characterizing the stress wave energy transfer properties of a material.

  2. 46 CFR 164.013-3 - Material properties and workmanship.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ..., AND MATERIALS: SPECIFICATIONS AND APPROVAL MATERIALS Foam, Unicellular Polyethylene (Buoyant, Slab, Slitted Trigonal Pattern) § 164.013-3 Material properties and workmanship. (a) General. The unicellular.... Unicellular polyethylene foam must comply with the requirements of UL 1191, sections 24, 25, and 26 and...

  3. 46 CFR 164.013-3 - Material properties and workmanship.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ..., AND MATERIALS: SPECIFICATIONS AND APPROVAL MATERIALS Foam, Unicellular Polyethylene (Buoyant, Slab, Slitted Trigonal Pattern) § 164.013-3 Material properties and workmanship. (a) General. The unicellular.... Unicellular polyethylene foam must comply with the requirements of UL 1191, sections 24, 25, and 26 and...

  4. 46 CFR 164.013-3 - Material properties and workmanship.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ..., AND MATERIALS: SPECIFICATIONS AND APPROVAL MATERIALS Foam, Unicellular Polyethylene (Buoyant, Slab, Slitted Trigonal Pattern) § 164.013-3 Material properties and workmanship. (a) General. The unicellular.... Unicellular polyethylene foam must comply with the requirements of UL 1191, sections 24, 25, and 26 and...

  5. 46 CFR 164.013-3 - Material properties and workmanship.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ..., AND MATERIALS: SPECIFICATIONS AND APPROVAL MATERIALS Foam, Unicellular Polyethylene (Buoyant, Slab, Slitted Trigonal Pattern) § 164.013-3 Material properties and workmanship. (a) General. The unicellular.... Unicellular polyethylene foam must comply with the requirements of UL 1191, sections 24, 25, and 26 and...

  6. 46 CFR 164.013-3 - Material properties and workmanship.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ..., AND MATERIALS: SPECIFICATIONS AND APPROVAL MATERIALS Foam, Unicellular Polyethylene (Buoyant, Slab, Slitted Trigonal Pattern) § 164.013-3 Material properties and workmanship. (a) General. The unicellular.... Unicellular polyethylene foam must comply with the requirements of UL 1191, sections 24, 25, and 26 and...

  7. Optimal experimental designs for the estimation of thermal properties of composite materials

    NASA Technical Reports Server (NTRS)

    Scott, Elaine P.; Moncman, Deborah A.

    1994-01-01

    Reliable estimation of thermal properties is extremely important in the utilization of new advanced materials, such as composite materials. The accuracy of these estimates can be increased if the experiments are designed carefully. The objectives of this study are to design optimal experiments to be used in the prediction of these thermal properties and to then utilize these designs in the development of an estimation procedure to determine the effective thermal properties (thermal conductivity and volumetric heat capacity). The experiments were optimized by choosing experimental parameters that maximize the temperature derivatives with respect to all of the unknown thermal properties. This procedure has the effect of minimizing the confidence intervals of the resulting thermal property estimates. Both one-dimensional and two-dimensional experimental designs were optimized. A heat flux boundary condition is required in both analyses for the simultaneous estimation of the thermal properties. For the one-dimensional experiment, the parameters optimized were the heating time of the applied heat flux, the temperature sensor location, and the experimental time. In addition to these parameters, the optimal location of the heat flux was also determined for the two-dimensional experiments. Utilizing the optimal one-dimensional experiment, the effective thermal conductivity perpendicular to the fibers and the effective volumetric heat capacity were then estimated for an IM7-Bismaleimide composite material. The estimation procedure used is based on the minimization of a least squares function which incorporates both calculated and measured temperatures and allows for the parameters to be estimated simultaneously.

  8. Fish gelatin: Material properties and applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The main difference between fish gelatin and mammalian gelatin is fish gelatin’s lower gelation temperature. This property limits the use of fish gelatin in applications that currently utilize mammalian gelatin. However, fish gelatin remains an attractive alterative to mammalian gelatin due to relig...

  9. Effects of tritium on material properties

    SciTech Connect

    Caskey, G.R. Jr.

    1985-01-01

    The effecs of tritium on deformation and fracture of metals are reviewed with emphasis on similarities and differences between tritium and the other hydrogen isotopes. Helium generated by radioactive decay of tritium introduces time dependent property changes not observed with protium or deuterium. On-going studies and topics for further investigations are identified. 17 refs., 6 figs., 9 tabs.

  10. Organic materials with nonlinear optical properties

    DOEpatents

    Stupp, S.I.; Son, S.; Lin, H.C.

    1995-05-02

    The present invention is directed to organic materials that have the ability to double or triple the frequency of light that is directed through the materials. Particularly, the present invention is directed to the compound 4-[4-(2R)-2-cyano-7-(4{prime}-pentyloxy-4-biphenylcarbonyloxy)phenylheptylidenephenylcarbonyloxy]benzaldehyde, which can double the frequency of light that is directed through the compound. The invention is also directed to the compound (12-hydroxy-5,7-dodecadiynyl)-4{prime}-[(4{prime}-pentyloxy-4-biphenyl)carbonyloxy]-4-biphenylcarboxylate, and its polymeric form. The polymeric form can triple the frequency of light directed through it. 4 figs.

  11. Tuning Surface Properties of Low Dimensional Materials via Strain Engineering.

    PubMed

    Yang, Shengchun; Liu, Fuzhu; Wu, Chao; Yang, Sen

    2016-08-01

    The promising and versatile applications of low dimensional materials are largely due to their surface properties, which along with their underlying electronic structures have been well studied. However, these materials may not be directly useful for applications requiring properties other than their natal ones. In recent years, strain has been shown to be an additionally useful handle to tune the physical and chemical properties of materials by changing their geometric and electronic structures. The strategies for producing strain are summarized. Then, the electronic structure of quasi-two dimensional layered non-metallic materials (e.g., graphene, MX2, BP, Ge nanosheets) under strain are discussed. Later, the strain effects on catalytic properties of metal-catalyst loaded with strain are focused on. Both experimental and computational perspectives for dealing with strained systems are covered. Finally, an outlook on engineering surface properties utilizing strain is provided. PMID:27376498

  12. BMDO materials testing in the EOIM-3 experiment

    NASA Technical Reports Server (NTRS)

    Chung, Shirley Y.; Brinza, David E.; Minton, Timothy K.; Liang, Ranty H.

    1995-01-01

    The NASA Evaluation of Oxygen Interactions with Materials-3 (EOIM-3) experiment served as a testbed for a variety of materials that are candidates for Ballistic Missile Defense Organization (BMDO) space assets. The materials evaluated on this flight experiment were provided by BMDO contractors and technology laboratories. A parallel ground-based exposure evaluation was conducted using the Fast Atom Sample Tester (FAST) atomic-oxygen simulation facility at Physical Sciences, Inc. The EOIM-3 flight materials were exposed to an atomic oxygen fluence of approximately 2.3 x 10(exp 20) atoms/sq cm. The ground-based exposure fluence of 2.0 - 2.5 x 10(exp 20) atoms/sq cm permits direct comparison with that of the flight-exposed specimens. The results from the flight test conducted aboard STS-46 and the correlative ground-based exposure are summarized here. A more detailed correlation study is presented in the JPL Publication 93-31 entitled 'Flight-and Ground-Test Correlation Study of BMDO SDS Materials: Phase 1 Report'. In general, the majority of the materials survived the AO environment with their performance tolerances maintained for the duration of the exposure. Optical materials, baffles, and coatings performed extremely well as did most of the thermal coatings and tribological materials. A few of the candidate radiator, threat shielding, and structural materials showed significant degradation. Many of the coatings designed to protect against AO erosion of sensitive materials performed this function well.

  13. IMAP: Interferometry for Material Property Measurement in MEMS

    SciTech Connect

    Jensen, B.D.; Miller, S.L.; de Boer, M.P.

    1999-03-10

    An interferometric technique has been developed for non-destructive, high-confidence, in-situ determination of material properties in MEMS. By using interferometry to measure the full deflection curves of beams pulled toward the substrate under electrostatic loads, the actual behavior of the beams has been modeled. No other method for determining material properties allows such detailed knowledge of device behavior to be gathered. Values for material properties and non-idealities (such as support post compliance) have then been extracted which minimize the error between the measured and modeled deflections. High accuracy and resolution have been demonstrated, allowing the measurements to be used to enhance process control.

  14. Data base for crack growth properties of materials

    NASA Technical Reports Server (NTRS)

    Forman, Royce G.; Lawrence, Victor B.; Nguy, Henry L.

    1988-01-01

    A computerized data base of crack growth properties of materials was developed for use in fracture control analysis of rocket engine components and other NASA space hardware. The software system has files of basic crack growth rate data, other fracture mechanics material properties such as fracture toughness and environmental crack growth threshold values, and plotting and fitting routines for deriving material properties for use in fracture control analysis. An extensive amount of data was collected and entered, and work is continuing on compiling additional data. The data base and software codes are useful both for fracture control analysis and for evaluation or development of improved crack growth theories.

  15. Properties of materials using acoustic waves

    NASA Astrophysics Data System (ADS)

    Apfel, R. E.

    1985-10-01

    Our goal of characterizing materials using acoustic waves was forwarded through a number of projects: (1) We have derived a theory, and tested it on tissues, for predicting the composition of composite materials using mixture rules, such as the one we derived for the nonlinear parameter two years ago; (2) We have published one article and another is in review on our use of modulated acoustic radiation pressure on levitated drops to characterize interfaces with and without surfactants. We have begun to study in a systematic way the nonlinear dynamics of drops, including drop fission: (3) we have improved apparatus for 30 MHz ultrasonic scattering from microparticles (approx. micron size), which should allow us to discriminate between different microparticles in a liquid; (4) We have begun to study the nonlinear mechanics of hydrodynamic solitons in cylindrical (2-d) geometry; and (5) We have been studying the use of acoustic levitation for transducer calibration.

  16. Properties of cathode materials in alkaline cells

    NASA Astrophysics Data System (ADS)

    Salkind, A. J.; McBreen, J.; Freeman, R.; Parkhurst, W. A.

    1984-04-01

    Conventional and new cathode materials in primary and secondary alkaline cells were investigated for stability, structure, electrochemical reversibility and efficiency. Included were various forms of AgO for reserve type silver zinc batteries, a new material - AgNiO2 and several nickel electrodes for nickel cadmium and nickel hydrogen cells for aerospace applications. A comparative study was made of the stability of electroformed and chemically prepared AgO. Stability was correlated with impurities. After the first discharge AgNiO2 can be recharged to the monovalent level. The discharge product is predominantly silver. Plastic bonded nickel electrodes display a second plateau on discharge. Additions of Co(OH)2 largely eliminate this.

  17. System Report for the Optical Properties Monitor (OPM) Experiment

    NASA Technical Reports Server (NTRS)

    Hummer, L.

    2001-01-01

    This systems report describes how the Optical Properties Monitor (OPM) experiment was developed. Pertinent design parameters are discussed, along with mission information and system requirements to successfully complete the mission. Environmental testing was performed on the OPM to certify it for spaceflight. This testing included vibration, thermal vacuum, electromagnetic interference and conductance, and toxicity tests. Instrument and monitor subsystem performances, including the reflectometer, vacuum ultraviolet, total integrated scatter, atomic oxygen monitor, irradiance monitor, and molecular contamination monitor during the mission are discussed. The OPM experiment was launched aboard the Space Shuttle on mission STS-81 in January 1997 and transferred to the Mir space station. An extravehicular activity (EVA) was performed in April 1997 to attach the OPM experiment to the outside of the Mir/Shuttle Docking Module for space environment exposure. The OPM conducted in situ measurements of a number of material samples. These data may be found in the OPM Science Report. OPM was retrieved during an EVA in January 1998 and was returned to Earth on board the Space Shuttle on mission STS-89.

  18. Mapping the fracture properties of engineering materials

    NASA Astrophysics Data System (ADS)

    Ashby, Mike

    2013-09-01

    Among Alan Cottrell's many extraordinary talents was that of an inspirational teacher. He had a masterful ability to explain the underlying physics of the Science of Materials and at the same time to simplify and to present the big picture. His teaching-texts live on, still among the clearest and most insightful expositions of the subject. This paper surveys part of one of the fields to which he contributed so much - Fracture - with education and the big picture in mind.

  19. Materials properties: heterogeneity and appropriate sampling modes.

    PubMed

    Esbensen, Kim H

    2015-01-01

    The target audience for this Special Section comprises parties related to the food and feed sectors, e.g., field samplers, academic and industrial scientists, laboratory personnel, companies, organizations, regulatory bodies, and agencies who are responsible for sampling, as well as project leaders, project managers, quality managers, supervisors, and directors. All these entities face heterogeneous materials, and the characteristics of heterogeneous materials needs to be competently understood by all of them. Before delivering analytical results for decision-making, one form or other of primary sampling is always necessary, which must counteract the effects of the sampling target heterogeneity. Up to five types of sampling error may arise as a specific sampling process interacts with a heterogeneous material; two sampling errors arise because of the heterogeneity of the sampling target, and three additional sampling errors are produced by the sampling process itself-if not properly understood, reduced, and/or eliminated, which is the role of Theory of Sampling. This paper discusses the phenomenon and concepts involved in understanding, describing, and managing the adverse effects of heterogeneity in sampling. PMID:25807041

  20. Temperature dependent terahertz properties of energetic materials

    NASA Astrophysics Data System (ADS)

    Azad, Abul K.; Whitley, Von H.; Brown, Kathryn E.; Ahmed, Towfiq; Sorensen, Christian J.; Moore, David S.

    2016-04-01

    Reliable detection of energetic materials is still a formidable challenge which requires further investigation. The remote standoff detection of explosives using molecular fingerprints in the terahertz spectral range has been an evolving research area for the past two decades. Despite many efforts, identification of a particular explosive remains difficult as the spectral fingerprints often shift due to the working conditions of the sample such as temperature, crystal orientation, presence of binders, etc. In this work, we investigate the vibrational spectrum of energetic materials including RDX, PETN, AN, and 1,3-DNB diluted in a low loss PTFE host medium using terahertz time domain spectroscopy (THz-TDS) at cryogenic temperatures. The measured absorptions of these materials show spectral shifts of their characteristic peaks while changing their operating temperature from 300 to 7.5 K. We have developed a theoretical model based on first principles methods, which is able to predict most of the measured modes in 1, 3-DNB between 0.3 to 2.50 THz. These findings may further improve the security screening of explosives.

  1. Emergent properties in experiments with active microparticles

    NASA Astrophysics Data System (ADS)

    Palacci, Jeremie

    Self-propelled micro-particles are intrinsically out-of-equilibrium. This renders their physics far richer than passive colloids and give rise to the emergence of complex phenomena e.g. collective behavior, swarming... I will present experimental demonstration of emergent properties beyond equilibrium.

  2. Challenges and Opportunities in Interdisciplinary Materials Research Experiences for Undergraduates

    NASA Astrophysics Data System (ADS)

    Vohra, Yogesh; Nordlund, Thomas

    2009-03-01

    The University of Alabama at Birmingham (UAB) offer a broad range of interdisciplinary materials research experiences to undergraduate students with diverse backgrounds in physics, chemistry, applied mathematics, and engineering. The research projects offered cover a broad range of topics including high pressure physics, microelectronic materials, nano-materials, laser materials, bioceramics and biopolymers, cell-biomaterials interactions, planetary materials, and computer simulation of materials. The students welcome the opportunity to work with an interdisciplinary team of basic science, engineering, and biomedical faculty but the challenge is in learning the key vocabulary for interdisciplinary collaborations, experimental tools, and working in an independent capacity. The career development workshops dealing with the graduate school application process and the entrepreneurial business activities were found to be most effective. The interdisciplinary university wide poster session helped student broaden their horizons in research careers. The synergy of the REU program with other concurrently running high school summer programs on UAB campus will also be discussed.

  3. Analysis of nonlinear optical properties in donor–acceptor materials

    SciTech Connect

    Day, Paul N.; Pachter, Ruth; Nguyen, Kiet A.

    2014-05-14

    Time-dependent density functional theory has been used to calculate nonlinear optical (NLO) properties, including the first and second hyperpolarizabilities as well as the two-photon absorption cross-section, for the donor-acceptor molecules p-nitroaniline and dimethylamino nitrostilbene, and for respective materials attached to a gold dimer. The CAMB3LYP, B3LYP, PBE0, and PBE exchange-correlation functionals all had fair but variable performance when compared to higher-level theory and to experiment. The CAMB3LYP functional had the best performance on these compounds of the functionals tested. However, our comprehensive analysis has shown that quantitative prediction of hyperpolarizabilities is still a challenge, hampered by inadequate functionals, basis sets, and solvation models, requiring further experimental characterization. Attachment of the Au{sub 2}S group to molecules already known for their relatively large NLO properties was found to further enhance the response. While our calculations show a modest enhancement for the first hyperpolarizability, the enhancement of the second hyperpolarizability is predicted to be more than an order of magnitude.

  4. Interdisciplinary research concerning the nature and properties of ceramic materials

    NASA Technical Reports Server (NTRS)

    1975-01-01

    The nature and properties of ceramic materials as they relate to solid state physics and metallurgy are studied. Special attention was given to the applications of ceramics to NASA programs and national needs.

  5. Novel thermal properties of nanostructured materials.

    SciTech Connect

    Eastman, J. A.

    1999-01-13

    A new class of heat transfer fluids, termed nanofluids, has been developed by suspending nanocrystalline particles in liquids. Due to the orders-of-magnitude larger thermal conductivities of solids compared to those of liquids such as water, significantly enhanced thermal properties are obtained with nanofluids. For example, an approximately 20% improvement in effective thermal conductivity is observed when 5 vol.% CuO nanoparticles are added to water. Even more importantly, the heat transfer coefficient of water under dynamic flow conditions is increased more than 15% with the addition of less than 1 vol.% CuO particles. The use of nanofluids could impact many industrial sectors, including transportation, energy supply and production, electronics, textiles, and paper production by, for example, decreasing pumping power needs or reducing heat exchanger sizes. In contrast to the enhancement in effective thermal transport rates that is obtained when nanoparticles are suspended in fluids, nanocrystalline coatings are expected to exhibit reduced thermal conductivities compared to coarse-grained coatings. Reduced thermal conductivities are predicted to arise because of a reduction in the mean free path of phonons due to presence of grain boundaries. This behavior, combined with improved mechanical properties, makes nanostructured zirconia coatings excellent candidates for future applications as thermal barriers. Yttria-stabilized zirconia (YSZ) thin films are being produced by metal-organic chemical vapor deposition techniques. Preliminary results have indicated that the thermal conductivity is reduced by approximately a factor-of-two at room temperature in 10 nm grain-sized YSZ compared to coarse-grained or single crystal YSZ.

  6. Accelerated search for materials with targeted properties by adaptive design.

    PubMed

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

    2016-01-01

    Finding new materials with targeted properties has traditionally been guided by intuition, and trial and error. With increasing chemical complexity, the combinatorial possibilities are too large for an Edisonian approach to be practical. Here we show how an adaptive design strategy, tightly coupled with experiments, can accelerate the discovery process by sequentially identifying the next experiments or calculations, to effectively navigate the complex search space. Our strategy uses inference and global optimization to balance the trade-off between exploitation and exploration of the search space. We demonstrate this by finding very low thermal hysteresis (ΔT) NiTi-based shape memory alloys, with Ti50.0Ni46.7Cu0.8Fe2.3Pd0.2 possessing the smallest ΔT (1.84 K). We synthesize and characterize 36 predicted compositions (9 feedback loops) from a potential space of ∼800,000 compositions. Of these, 14 had smaller ΔT than any of the 22 in the original data set. PMID:27079901

  7. Accelerated search for materials with targeted properties by adaptive design

    NASA Astrophysics Data System (ADS)

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

    2016-04-01

    Finding new materials with targeted properties has traditionally been guided by intuition, and trial and error. With increasing chemical complexity, the combinatorial possibilities are too large for an Edisonian approach to be practical. Here we show how an adaptive design strategy, tightly coupled with experiments, can accelerate the discovery process by sequentially identifying the next experiments or calculations, to effectively navigate the complex search space. Our strategy uses inference and global optimization to balance the trade-off between exploitation and exploration of the search space. We demonstrate this by finding very low thermal hysteresis (ΔT) NiTi-based shape memory alloys, with Ti50.0Ni46.7Cu0.8Fe2.3Pd0.2 possessing the smallest ΔT (1.84 K). We synthesize and characterize 36 predicted compositions (9 feedback loops) from a potential space of ~800,000 compositions. Of these, 14 had smaller ΔT than any of the 22 in the original data set.

  8. Accelerated search for materials with targeted properties by adaptive design

    PubMed Central

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

    2016-01-01

    Finding new materials with targeted properties has traditionally been guided by intuition, and trial and error. With increasing chemical complexity, the combinatorial possibilities are too large for an Edisonian approach to be practical. Here we show how an adaptive design strategy, tightly coupled with experiments, can accelerate the discovery process by sequentially identifying the next experiments or calculations, to effectively navigate the complex search space. Our strategy uses inference and global optimization to balance the trade-off between exploitation and exploration of the search space. We demonstrate this by finding very low thermal hysteresis (ΔT) NiTi-based shape memory alloys, with Ti50.0Ni46.7Cu0.8Fe2.3Pd0.2 possessing the smallest ΔT (1.84 K). We synthesize and characterize 36 predicted compositions (9 feedback loops) from a potential space of ∼800,000 compositions. Of these, 14 had smaller ΔT than any of the 22 in the original data set. PMID:27079901

  9. 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.

  10. Electrical properties of commercial sheet insulation materials for cryogenic applications

    SciTech Connect

    Tuncer, Enis; Sauers, Isidor; James, David Randy; Ellis, Alvin R; Pace, Marshall O

    2008-01-01

    Dielectric properties of electrical insulation materials are needed for low-temperature power applications. Performance of materials and their compatibility determine the size of the electrical insulation in power equipment. In this work we report the dielectric properties of some commercially available materials in sheet form. The selected materials are polypropylene laminated paper from Sumitomo Electric U.S.A., Inc., porous polyethylene (Tyvek\\texttrademark) from Dupont, and polyamide paper (Nomex\\texttrademark) from Dupont. The dielectric properties are characterized with an electrical impedance analyzer in the frequency domain. The impedances are recorded in a cryocooler in the temperature range from 50 to 300 K. The dielectric breakdown characteristics of the materials are measured in a liquid nitrogen bath at atmospheric pressure.

  11. Chemical hydrogen storage material property guidelines for automotive applications

    NASA Astrophysics Data System (ADS)

    Semelsberger, Troy A.; Brooks, Kriston P.

    2015-04-01

    Chemical hydrogen storage is the sought after hydrogen storage media for automotive applications because of the expected low pressure operation (<20 atm), moderate temperature operation (<200 °C), system gravimetric capacities (>0.05 kg H2/kgsystem), and system volumetric capacities (>0.05 kg H2/Lsystem). Currently, the primary shortcomings of chemical hydrogen storage are regeneration efficiency, fuel cost and fuel phase (i.e., solid or slurry phase). Understanding the required material properties to meet the DOE Technical Targets for Onboard Hydrogen Storage Systems is a critical knowledge gap in the hydrogen storage research community. This study presents a set of fluid-phase chemical hydrogen storage material property guidelines for automotive applications meeting the 2017 DOE technical targets. Viable material properties were determined using a boiler-plate automotive system design. The fluid-phase chemical hydrogen storage media considered in this study were neat liquids, solutions, and non-settling homogeneous slurries. Material properties examined include kinetics, heats of reaction, fuel-cell impurities, gravimetric and volumetric hydrogen storage capacities, and regeneration efficiency. The material properties, although not exhaustive, are an essential first step in identifying viable chemical hydrogen storage material properties-and most important, their implications on system mass, system volume and system performance.

  12. Analytic Thermoelectric Couple Modeling: Variable Material Properties and Transient Operation

    NASA Technical Reports Server (NTRS)

    Mackey, Jonathan A.; Sehirlioglu, Alp; Dynys, Fred

    2015-01-01

    To gain a deeper understanding of the operation of a thermoelectric couple a set of analytic solutions have been derived for a variable material property couple and a transient couple. Using an analytic approach, as opposed to commonly used numerical techniques, results in a set of useful design guidelines. These guidelines can serve as useful starting conditions for further numerical studies, or can serve as design rules for lab built couples. The analytic modeling considers two cases and accounts for 1) material properties which vary with temperature and 2) transient operation of a couple. The variable material property case was handled by means of an asymptotic expansion, which allows for insight into the influence of temperature dependence on different material properties. The variable property work demonstrated the important fact that materials with identical average Figure of Merits can lead to different conversion efficiencies due to temperature dependence of the properties. The transient couple was investigated through a Greens function approach; several transient boundary conditions were investigated. The transient work introduces several new design considerations which are not captured by the classic steady state analysis. The work helps to assist in designing couples for optimal performance, and also helps assist in material selection.

  13. MIDAS (Material Implementation, Database, and Analysis Source): A comprehensive resource of material properties

    SciTech Connect

    Tang, M; Norquist, P; Barton, N; Durrenberger, K; Florando, J; Attia, A

    2010-12-13

    MIDAS is aimed to be an easy-to-use and comprehensive common source for material properties including both experimental data and models and their parameters. At LLNL, we will develop MIDAS to be the central repository for material strength related data and models with the long-term goal to encompass other material properties. MIDAS will allow the users to upload experimental data and updated models, to view and read materials data and references, to manipulate models and their parameters, and to serve as the central location for the application codes to access the continuously growing model source codes. MIDAS contains a suite of interoperable tools and utilizes components already existing at LLNL: MSD (material strength database), MatProp (database of materials properties files), and MSlib (library of material model source codes). MIDAS requires significant development of the computer science framework for the interfaces between different components. We present the current status of MIDAS and its future development in this paper.

  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. Use of material dielectric properties for agricultural applications

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The use of dielectric properties of materials for applications in agriculture are reviewed, and research findings on use of dielectric heating of materials and on sensing of product moisture content and other quality factors are discussed. Dielectric heating applications, include treatment of seed...

  16. Heat Transmission Properties of Insulating and Building Materials

    National Institute of Standards and Technology Data Gateway

    SRD 81 NIST Heat Transmission Properties of Insulating and Building Materials (Web, free access)   NIST has accumulated a valuable and comprehensive collection of thermal conductivity data. Version 1.0 of the database includes data for over 2000 measurements, covering several categories of materials including concrete, fiberboard, plastics, thermal insulation, and rubber.

  17. Perspective: Interactive material property databases through aggregation of literature data

    NASA Astrophysics Data System (ADS)

    Seshadri, Ram; Sparks, Taylor D.

    2016-05-01

    Searchable, interactive, databases of material properties, particularly those relating to functional materials (magnetics, thermoelectrics, photovoltaics, etc.) are curiously missing from discussions of machine-learning and other data-driven methods for advancing new materials discovery. Here we discuss the manual aggregation of experimental data from the published literature for the creation of interactive databases that allow the original experimental data as well additional metadata to be visualized in an interactive manner. The databases described involve materials for thermoelectric energy conversion, and for the electrodes of Li-ion batteries. The data can be subject to machine-learning, accelerating the discovery of new materials.

  18. Compact rock material gas permeability properties

    NASA Astrophysics Data System (ADS)

    Wang, Huanling; Xu, Weiya; Zuo, Jing

    2014-09-01

    Natural compact rocks, such as sandstone, granite, and rock salt, are the main materials and geological environment for storing underground oil, gas, CO2, shale gas, and radioactive waste because they have extremely low permeabilities and high mechanical strengths. Using the inert gas argon as the fluid medium, the stress-dependent permeability and porosity of monzonitic granite and granite gneiss from an underground oil storage depot were measured using a permeability and porosity measurement system. Based on the test results, models for describing the relationships among the permeability, porosity, and confining pressure of rock specimens were analyzed and are discussed. A power law is suggested to describe the relationship between the stress-dependent porosity and permeability; for the monzonitic granite and granite gneiss (for monzonitic granite (A-2), the initial porosity is approximately 4.05%, and the permeability is approximately 10-19 m2; for the granite gneiss (B-2), the initial porosity is approximately 7.09%, the permeability is approximately 10-17 m2; and the porosity-sensitivity exponents that link porosity and permeability are 0.98 and 3.11, respectively). Compared with moderate-porosity and high-porosity rocks, for which φ > 15%, low-porosity rock permeability has a relatively lower sensitivity to stress, but the porosity is more sensitive to stress, and different types of rocks show similar trends. From the test results, it can be inferred that the test rock specimens' permeability evolution is related to the relative particle movements and microcrack closure.

  19. Thermophysical Properties of Polymer Materials with High Thermal Conductivity

    NASA Astrophysics Data System (ADS)

    Lebedev, S. M.; Gefle, O. S.; Dneprovskii, S. N.; Amitov, E. T.

    2015-06-01

    Results of studies on the main thermophysical properties of new thermally conductive polymer materials are presented. It is shown that modification of polymer dielectrics by micron-sized fillers allows thermally conductive materials with thermal conductivity not less than 2 W/(m K) to be produced, which makes it possible to use such materials as cooling elements of various electrical engineering and semiconductor equipment and devices.

  20. MISSE 6, 7 and 8 Materials Sample Experiments from the International Space Station Materials and Processes Team

    NASA Technical Reports Server (NTRS)

    Kravchenko, Michael; ORourke, Mary Jane; Golden, Johnny; Finckenor, Miria; Leatherwood, Michael; Alred, John

    2010-01-01

    The International Space Station Materials and Processes (ISS M&P) team has multiple material samples on MISSE 6, 7 and 8 to observe Low Earth Orbit (LEO) environmental effects on Space Station materials. Optical properties, thickness/mass loss, surface elemental analysis, visual and microscopic analysis for surface change are some of the techniques employed in this investigation. The ISS M&P team has participated in previous MISSE activities in order to better characterize the LEO effects on Space Station materials. This investigation will further this effort. Results for the following MISSE 6 samples materials will be presented: a comparison of anodize and chemical conversion coatings on various aluminum alloys, electroless nickel; AZ93 white ceramic thermal control coating with and without Teflon; Hyzod(TM) polycarbonate used to temporarily protect ISS windows; Russian quartz window material; reformulated Teflon (TM) coated Beta Cloth (Teflon TM without perfluorooctanoic acid (PFOA)) and a Dutch version of beta cloth. Discussion for current and future MISSE materials experiments will be presented. MISSE 7 samples are: deionized water sealed anodized aluminum Photofoil(TM); indium tin oxide (ITO)- coated Kapton(TM) used as thermo-optical surfaces; mechanically scribed tin-plated beryllium-copper samples for "tin pest" growth ( alpha/Beta transformation); Crew Exploration Vehicle (CEV) parachute soft goods. MISSE 8 sample: exposed "scrim cloth" (fiberglass weave) from the ISS solar array wing material, Davlyn fiberglass sleeve material, Permacel and Intertape protective tapes, and ITO-coated Kapton.

  1. Material Analysis/Characterization for Ultra-Low Background Experiments

    NASA Astrophysics Data System (ADS)

    Jasinski, Ben

    For the discovery of rare event physics processes related to new physics beyond the Standard Model, the next generation of physics experiments requires to be built underground. For instance, the Large Underground Xenon experiment and MAJORANA DEMONSTRATOR, both located underground at the Sanford Underground Research Facility (SURF), require an ultra-low background rate for their respective discovery of Dark Matter and the Majorana particle. The next generation of detectors designated for these ultra-low background experiments require a complete understanding of the materials used in the experiment to achieve the detection sensitivity below the current limits. Experimental limits can be seen in ton scale detector designs where ultrapure materials are needed for detector performance, suppression of background radiation, and electronic noise. This thesis studies the three main aspects of ultra-low background experiments. First, an investigation of the mechanical design constraints for SURF underground physics experiments is performed. Second, a study into each detector's characterization and performance is described for the SURF experiments. Lastly, an optimization of data analysis algorithm for rare event physics is discussed. We describe the techniques used for the above three investigations in detail. First, the test of the mechanical design constraints is investigated using an adaptive sample holder capable of testing sample materials of gas, liquid or solid state. Second, the characterization of materials is studied with a design of a Capacitance-Voltage Measurement system. Lastly, the optimization of data analysis algorithm for small signals is performed by a detailed data analysis to verify isotopic enrichment obtained from a novel isotope separation method of molecules of CO2.

  2. Structural, magnetic, and transport properties of Permalloy for spintronic experiments

    SciTech Connect

    Nahrwold, Gesche; Scholtyssek, Jan M.; Motl-Ziegler, Sandra; Albrecht, Ole; Merkt, Ulrich; Meier, Guido

    2010-07-15

    Permalloy (Ni{sub 80}Fe{sub 20}) is broadly used to prepare magnetic nanostructures for high-frequency experiments where the magnetization is either excited by electrical currents or magnetic fields. Detailed knowledge of the material properties is mandatory for thorough understanding its magnetization dynamics. In this work, thin Permalloy films are grown by dc-magnetron sputtering on heated substrates and by thermal evaporation with subsequent annealing. The specific resistance is determined by van der Pauw methods. Point-contact Andreev reflection is employed to determine the spin polarization of the films. The topography is imaged by atomic-force microscopy, and the magnetic microstructure by magnetic-force microscopy. Transmission-electron microscopy and transmission-electron diffraction are performed to determine atomic composition, crystal structure, and morphology. From ferromagnetic resonance absorption spectra the saturation magnetization, the anisotropy, and the Gilbert damping parameter are determined. Coercive fields and anisotropy are measured by magneto-optical Kerr magnetometry. The sum of the findings enables optimization of Permalloy for spintronic experiments.

  3. Optimization of low gravity materials processing experiments using expert systems

    NASA Technical Reports Server (NTRS)

    Workman, Gary L.; Choudry, Amar

    1988-01-01

    The use of an expert system for the control of materials processing experiments in a facility such as the Space Station provides a number of attractive features for insuring that certain critical process parameters can be used to optimize the productivity of the materials processing experiments. The proposed approach to implementation of an expert system utilizes a knowledge base of desired process characteristics which will provide the desired results. The knowledge base for each experiment will be created in conjunction with the scientific investigator in charge of the experiment. Improvements to the knowledge base will be expanded to include self learning sessions in ground based experiments in order to teach the expert system how to respond to perturbations in the process and update the knowledge base on what process change should be implemented in order to reach the desired end product. Design considerations using an on-line real time expert system such as PICON is studied. The types of experiments evaluated include several types of solidification experiments which will be performed on the Space Station.

  4. 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.

  5. Chemical hydrogen storage material property guidelines for automotive applications

    SciTech Connect

    Semelsberger, Troy; Brooks, Kriston P.

    2015-04-01

    Chemical hydrogen storage is the sought after hydrogen storage media for automotive applications because of the expected low pressure operation (<20 atm), moderate temperature operation (<200 C), system gravimetric capacities (>0.05 kg H2/kg system), and system volumetric capacities (>0.05 kg H2/L system). Currently, the primary shortcomings of chemical hydrogen storage are regeneration efficiency, fuel cost and fuel phase (i.e., solid or slurry phase). Understanding the required material properties to meet the DOE Technical Targets for Onboard Hydrogen Storage Systems is a critical knowledge gap in the hydrogen storage research community. This study presents a set of fluid-phase chemical hydrogen storage material property guidelines for automotive applications meeting the 2017 DOE technical targets. Viable material properties were determined using a boiler-plate automotive system design. The fluid phase chemical hydrogen storage media considered in this study were neat liquids, solutions, and non-settling homogeneous slurries. Material properties examined include kinetics, heats of reaction, fuel-cell impurities, gravimetric and volumetric hydrogen storage capacities, and regeneration efficiency. The material properties, although not exhaustive, are an essential first step in identifying viable chemical hydrogen storage material propertiesdand most important, their implications on system mass, system volume and system performance.

  6. Models for predicting temperature dependence of material properties of aluminum

    NASA Astrophysics Data System (ADS)

    Marla, Deepak; Bhandarkar, Upendra V.; Joshi, Suhas S.

    2014-03-01

    A number of processes such as laser ablation, laser welding, electric discharge machining, etc involve high temperatures. Most of the processes involve temperatures much higher than the target melting and normal boiling point. Such large variation in target temperature causes a significant variation in its material properties. Due to the unavailability of experimental data on material properties at elevated temperatures, usually the data at lower temperatures is often erroneously extrapolated during modelling of these processes. Therefore, this paper attempts to evaluate the variation in material properties with temperature using some general and empirical theories, along with the available experimental data for aluminum. The evaluated properties of Al using the proposed models show a significant variation with temperature. Between room temperature and near-critical temperature (0.9Tc), surface reflectivity of Al varies from more than 90% to less than 50%, absorption coefficient decreases by a factor of 7, thermal conductivity decreases by a factor of 5, density decreases by a factor of 4, specific heat and latent heat of vapourization vary by a factor between 1.5 and 2. Applying these temperature-dependent material properties for modelling laser ablation suggest that optical properties have a greater influence on the process than thermophysical properties. The numerical predictions of the phase explosion threshold in laser ablation are within 5% of the experimental values.

  7. Surface electrical properties experiment, part 1. [flown on Apollo 17

    NASA Technical Reports Server (NTRS)

    Strangway, D. W.; Annan, A. P.; Redman, J. D.; Rossiter, J. R.; Rylaarsdam, J. A.; Watts, R. D.

    1974-01-01

    The work is reported which was performed on the Surface Electrical Properties Experiment Data Acquisition System. Areas discussed include: data handling and processing, installation and external signal application, operation of the equipment, and digital output. Detailed circuit descriptions are included.

  8. The magnetic properties experiments on Mars Pathfinder

    NASA Astrophysics Data System (ADS)

    Madsen, M. B.; Hviid, S. F.; Gunnlaugsson, H. P.; Knudsen, J. M.; Goetz, W.; Pedersen, C. T.; Dinesen, A. R.; Mogensen, C. T.; Olsen, M.; Hargraves, R. B.

    1999-04-01

    The Mars Pathfinder lander carried two magnet arrays, each containing five small permanent magnets of varying strength. The magnet arrays were passively exposed to the wind borne dust on Mars. By the end of the Mars Pathfinder mission a bull's-eye pattern was visible on the four strongest magnets of the arrays showing the presence of magnetic dust particles. From the images we conclude that the dust suspended in the atmosphere is not solely single phase particles of hematite (α-Fe2O3) and that single phase particles of the ferrimagnetic minerals maghemite (γ-Fe2O3) or magnetite (Fe3O4) are not present as free particles in any appreciable amount. The material on the strongest magnets seems to be indistinguishable from the bright surface material around the lander. From X-ray fluorescence it is known that the soil consists mainly of silicates. The element iron constitutes about 13% of the soil. The particles in the airborne dust seem to be composite, containing a few percent of a strongly magnetic component. We conclude that the magnetic phase present in the airborne dust particles is most likely maghemite. The particles thus appear to consist of silicate aggregates stained or cemented by ferric oxides, some of the stain and cement being maghemite. These results imply that Fe2+ ions were leached from the bedrock, and after passing through a state as free Fe2+ ions in liquid water, the Fe2+ was oxidized to Fe3+ and then precipitated. It cannot, however, be ruled out that the magnetic particles are titanomagnetite (or titanomaghemite) occurring in palagonite, having been inherited directly from the bedrock.

  9. Single particle measurements of material line stretching in turbulence: Experiments

    NASA Astrophysics Data System (ADS)

    Kramel, Stefan; Tympel, Saskia; Toschi, Federico; Voth, Greg

    2015-11-01

    We find that particles in the shape of chiral dipoles display a preferential rotation direction in three dimensional isotropic turbulence. The particles consist of two helical ends with opposite chirality that are connected by a straight rod. They are fabricated using 3D printing and have an aspect ratio of 10 and a length in the inertial range of our flow between oscillating grids. Due to their high aspect ratio, they move like material lines. Because material lines align with the extentional eigenvectors of the velocity gradient tensor they experience a mean stretching in turbulence. The stretching of a chiral dipole produces a rotation about the dipole axis and so chiral dipoles experience a non-zero mean spinning rate in turbulence. These results provide a first direct experimental measurement of the rate of material line stretching in turbulence.

  10. Changes in the Optical Properties of Materials Are Observed After 18 Months in Low Earth Orbit

    NASA Technical Reports Server (NTRS)

    Jaworske, Donald A.

    1999-01-01

    Materials located on the exterior of spacecraft in low Earth orbit are subjected to a number of environmental threats, including atomic oxygen, ultraviolet radiation, thermal cycling, and micrometeroid and debris impact. Atomic oxygen attacks materials vulnerable to oxidation. Ultraviolet radiation can break chemical bonds and cause undesirable changes in optical properties. Thermal cycling can cause cracking, and micrometeroid and debris impacts can damage protective coatings. Another threat is contamination. The outgassing of volatile chemicals can contaminate nearby surfaces, changing their thermal control properties. Contaminated surfaces may undergo further change as a result of atomic oxygen and ultraviolet radiation exposure. The Passive Optical Sample Assembly (POSA) experiment was designed as a risk mitigation experiment for the International Space Station. Samples were characterized before launch, exposed for 18 months on the exterior of Mir, and characterized upon their return. Lessons learned from POSA about the durability of material properties can be applied to the space station and other long-duration missions.