Sample records for mechanical properties ofsteel

  1. Mechanical property scatter in CFCCs

    SciTech Connect (OSTI)

    Steen, M.; Filiou, C.

    2000-01-01T23:59:59.000Z

    The tensile response of continuous fiber reinforced ceramic matrix composites (CFCCs) is not expected to show the large variation in strength properties commonly observed for monolithic ceramics. Results of recent investigations on a number of two-dimensional reinforced CFCCs have nevertheless revealed a considerable scatter in the initial elastic modulus, in the first matrix cracking stress and in the failure stress. One school of thought considers that the observed variability is caused by experimental factors. Elaborate testing programs have been set up to clarify the origins of this scatter by investigation of the effects of control mode, loading rate, specimen shape, etc. Another school explains the scatter by the presence of (axial) residual stresses in the fibers and in the matrix. Although plausible, this hypothesis is difficult to verify because experimental determination of the residual stress state in CFCCs is not straightforward. In addition, with the available methods it is impractical to determine the residual stresses in every test specimen. This approach is indeed required for establishing the relationship between the magnitude of the residual stresses and the experimentally observed scatter. At IAM a method has been developed and validated which allows to quantify the axial residual stress state in individual CFCC specimens by subjecting them to intermittent unloading-reloading cycles. The method as well as the derived relationship between residual stress state and scatter in mechanical response will be presented.

  2. Microstructure and Thermoelectric Properties of Mechanically...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Microstructure and Thermoelectric Properties of Mechanically Robust PbTe-Si Eutectic Composites Home Author: J. R. Sootsman, J. He, V. P. Dravid, S. Ballikaya, D. Vermeulen, C....

  3. Small Specimen Mechanical Property Testing at PNNL

    E-Print Network [OSTI]

    McDonald, Kirk

    Small Specimen Mechanical Property Testing at PNNL Mychailo Toloczko, Dave Senor Pacific Northwest National Laboratory December, 2013 1 #12;Overview of PNNL Capabilities for Small Specimen Testing Long

  4. Enhancement of mechanical properties of 123 superconductors

    DOE Patents [OSTI]

    Balachandran, U.

    1995-04-25T23:59:59.000Z

    A composition and method are disclosed of preparing YBa{sub 2}Cu{sub 3}O{sub 7{minus}x} superconductor. Addition of tin oxide containing compounds to YBCO superconductors results in substantial improvement of fracture toughness and other mechanical properties without affect on T{sub c}. About 5-20% additions give rise to substantially improved mechanical properties.

  5. Enhancement of mechanical properties of 123 superconductors

    DOE Patents [OSTI]

    Balachandran, Uthamalingam (Hinsdale, IL)

    1995-01-01T23:59:59.000Z

    A composition and method of preparing YBa.sub.2 Cu.sub.3 O.sub.7-x superconductor. Addition of tin oxide containing compounds to YBCO superconductors results in substantial improvement of fracture toughness and other mechanical properties without affect on T.sub.c. About 5-20% additions give rise to substantially improved mechanical properties.

  6. Reconstruction of Sedimentary Rock Based on Mechanical Properties

    E-Print Network [OSTI]

    Jin, Guodong; Patzek, Tad W.; Silin, Dmitry B.

    2008-01-01T23:59:59.000Z

    the veri?cation of rock mechanical properties. The dynamicis white. IV. ROCK MECHANICAL PROPERTIES FIG. 9: Cementationextracting meaningful rock transport properties from these

  7. MECHANICAL PROPERTIES AND DEFORMATION MECHANISMS OF A COMMERCIALLY PURE TITANIUM

    E-Print Network [OSTI]

    Nemat-Nasser, Sia

    MECHANICAL PROPERTIES AND DEFORMATION MECHANISMS OF A COMMERCIALLY PURE TITANIUM S. NEMAT titanium (CP-Ti) is systematically investigated in quasi-static (Instron, servohydraulic) and dynamic (UCSD Acta Metallurgica Inc. Published by Elsevier Science Ltd. All rights reserved. Keywords: Titanium

  8. Complex Mechanical Properties of Steel

    E-Print Network [OSTI]

    Dimitriu, Radu

    that in this latter regime, the slope of the hot–strength versus temperature plot is identical to that of creep rupture–strength versus temperature. This significant outcome can help dramatically reduce the requirement for expensive creep testing. Similarly, a model... measured in a tensile test. The rate of this deformation is a function of the material properties, exposure time, temperature and the applied load. Creep naturally becomes important when evaluating components that operate under high stresses...

  9. Mechanical properties of reconstituted Australian black coal

    SciTech Connect (OSTI)

    Jasinge, D.; Ranjith, P.G.; Choi, S.K.; Kodikara, J.; Arthur, M.; Li, H. [Monash University, Clayton, Vic. (Australia). Dept. of Civil Engineering

    2009-07-15T23:59:59.000Z

    Coal is usually highly heterogeneous. Great variation in properties can exist among samples obtained even at close proximity within the same seam or within the same core sample. This makes it difficult to establish a correlation between uniaxial compressive strength (UCS) and point load index for coal. To overcome this problem, a method for making reconstituted samples for laboratory tests was developed. Samples were made by compacting particles of crushed coal mixed with cement and water. These samples were allowed to cure for four days. UCS and point load tests were performed to measure the geomechanical properties of the reconstituted coal. After four days curing, the average UCS was found to be approximately 4 MPa. This technical note outlines some experimental results and correlations that were developed to predict the mechanical properties of the reconstituted black coal samples. By reconstituting the samples from crushed coal, it is hoped that the samples will retain the important mechanical and physicochemical properties of coal, including the swelling, fluid transport, and gas sorption properties of coal. The aim is to be able to produce samples that are homogeneous with properties that are highly reproducible, and the reconstituted coal samples can be used for a number of research areas related to coal, including the long-term safe storage of CO{sub 2} in coal seams.

  10. Mechanical Properties of Aerogels. Final Report

    SciTech Connect (OSTI)

    Parmenter, K.E.; Milstein, F.

    1995-01-01T23:59:59.000Z

    Aerogels are extremely low density solids that are characterized by a high porosity and pore sizes on the order of nanometers. Their low thermal conductivity and sometimes transparent appearance make them desirable for applications such as insulation in cryogenic vessels and between double paned glass in solar architecture. An understanding of the mechanical properties of aerogels is necessary before aerogels can be used in load bearing applications. In the present study, the mechanical behavior of various types of fiber-reinforced silica aerogels was investigated with hardness, compression, tension and shear tests. Particular attention was paid to the effects of processing parameters, testing conditions, storage environment, and age on the aerogels` mechanical response. The results indicate that the addition of fibers to the aerogel matrix generally resulted in softer, weaker materials with smaller elastic moduli. Furthermore, the testing environment significantly affected compression results. Tests in ethanol show an appreciable amount of scatter, and are not consistent with results for tests in air. In fact, the compression specimens appeared to crack and begin to dissolve upon exposure to the ethanol solution. This is consistent with the inherent hydrophobic nature of these aerogels. In addition, the aging process affected the aerogels` mechanical behavior by increasing their compressive strength and elastic moduli while decreasing their strain at fracture. However, desiccation of the specimens did not appreciably affect the mechanical properties, even though it reduced the aerogel density by removing trapped moisture. Finally, tension and shear test results indicate that the shear strength of the aerogels exceeds the tensile strength. This is consistent with the response of brittle materials. Future work should concentrate on mechanical testing at cryogenic temperatures, and should involve more extensive tensile tests.

  11. Mechanical Properties of Nuclear Fuel Surrogates using Picosecond Laser Ultrasonics

    SciTech Connect (OSTI)

    David Hurley; Marat Khafizov; Farhad Farzbod; Eric Burgett

    2013-05-01T23:59:59.000Z

    Detailed understanding between microstructure evolution and mechanical properties is important for designing new high burnup nuclear fuels. In this presentation we discuss the use of picosecond ultrasonics to measure localize changes in mechanical properties of fuel surrogates. We develop measurement techniques that can be applied to investigate heterogeneous elastic properties caused by localize changes in chemistry, grain microstructure caused by recrystallization, and mechanical properties of small samples prepared using focused ion beam sample preparation. Emphasis is placed on understanding the relationship between microstructure and mechanical properties

  12. The normal basilar artery: structural properties and mechanical behavior 

    E-Print Network [OSTI]

    Wicker, Bethany Kay

    2009-05-15T23:59:59.000Z

    is a well established model for vasospasm. However, surprisingly little is known about the mechanical properties of the rabbit basilar artery. Using an in vitro custom organ culture and mechanical testing device, acute and cultured basilar arteries from...

  13. Mechanical and biochemical properties of human cervical tissue

    E-Print Network [OSTI]

    Myers, Kristin M

    2005-01-01T23:59:59.000Z

    The mechanical integrity of cervical tissue is crucial for maintaining a healthy gestation. Altered tissue biochemistry can cause drastic changes in the mechanical properties of the cervix and contribute to premature ...

  14. MICROSTRUCTURE AND MECHANICAL PROPERTIES OF ELECTROPLATED Cu THIN FILMS

    E-Print Network [OSTI]

    Volinsky, Alex A.

    MICROSTRUCTURE AND MECHANICAL PROPERTIES OF ELECTROPLATED Cu THIN FILMS A.A. Volinsky* , J. Vella size, thin film microstructure and mechanical properties have become critical parameters-K dielectric materials and novel interconnects (Cu). For most reliability tests, knowledge of the thin film

  15. Mechanical Properties of Porous-Matrix Ceramic Composites**

    E-Print Network [OSTI]

    Zok, Frank

    REVIEWS Mechanical Properties of Porous- Matrix Ceramic Composites** By Frank W. Zok* and Carlos G/Mechanical Properties of Porous-Matrix Ceramic Composites REVIEWS The porous matrix concept has been developed primarily. Levi 1. Introduction Damage tolerance can be enabled in continuous fiber-rein- forced ceramic

  16. THE MECHANICAL PROPERTIES OF STRIPA GRANITE

    E-Print Network [OSTI]

    Swan, G.

    2011-01-01T23:59:59.000Z

    dependency of Stripa granite . . o Unaxial compressionproperties of Stripa granite are presented as determinedPROPERTIES OF STRIPA GRANITE TWO-WEEK LOAN COpy Graham

  17. Determination of mechanical properties of reservoir rock

    E-Print Network [OSTI]

    Barnett, Ashley

    1993-01-01T23:59:59.000Z

    Apparatus, experimental procedure, and methodology have been developed to determine the mechanical response of reservoir rock. The apparatus is capable of subjecting cylindrical core specimens to triaxial stress states and temperatures...

  18. Mechanical Properties of Bulk Metallic Glasses and Composites

    E-Print Network [OSTI]

    Lee, M.L.

    We have studied the mechanical properties of monolithic bulk metallic glasses and composite in the La based alloys. La???yAl??(Cu, Ni)y (y=24 to 32) alloy systems was used to cast the ...

  19. Engineering the Microstructure of Hydrogels to Achieve Enhanced Mechanical Properties

    E-Print Network [OSTI]

    Suekama, Tiffany

    2014-05-31T23:59:59.000Z

    Hydrogels are three-dimensional, cross-linked, polymeric networks that are typically soft materials that contain more than 90% water. Many technologies require hydrogels with improved mechanical properties (modulus, failure ...

  20. Measurements of electrical and mechanical properties of aluminum composite cryoconductors

    E-Print Network [OSTI]

    Sundby, Paul C.

    1994-01-01T23:59:59.000Z

    The results of annealing on the residual resistance ratio (RRR) of five (5) composite aluminum cryoconductor wires and mechanical properties on fifteen (15) aluminum cryoconductor wires are presented. The independent variables of the study include...

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

    SciTech Connect (OSTI)

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

    1999-01-25T23:59:59.000Z

    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.

  2. GlossaryMechanical Properties of Materials Page 1 of 9

    E-Print Network [OSTI]

    Paxton, Anthony T.

    GlossaryMechanical Properties of Materials Page 1 of 9 Glossary of Technical terms used that they do not exhibit the same physical properties in all directions, e.g. long chain polymers which have to materials used in medical applications. The specific environment of a living body, being acceptable

  3. MECHANICAL PROPERTIES AND MICROSTRUCTURAL EVOLUTIONS AT HIGH STRAIN RATES OF

    E-Print Network [OSTI]

    Gubicza, Jenõ

    characteristics of high purity nickel processed by electrodeposition tested in compression up to a dynamic strainMECHANICAL PROPERTIES AND MICROSTRUCTURAL EVOLUTIONS AT HIGH STRAIN RATES OF ELECTRODEPOSITED NICKEL H. Couque1 , A. Ouarem2 , G. Dirras2 and J. Gubicza3 Summary ­ The mechanical and microstructural

  4. Mechanical Properties of Lithium-Ion Battery Separator Materials

    E-Print Network [OSTI]

    Petta, Jason

    -ion batteries like on the inside Anode Separator Cathode 500 nm 20 um20 um Anode: Graphite SeparatorMechanical Properties of Lithium-Ion Battery Separator Materials Patrick Sinko B.S. Materials and motivation ­ Why study lithium-ion batteries? ­ Lithium-ion battery fundamentals ­ Why study the mechanical

  5. Natural rubber-clay nanocomposites: mechanical and structural properties

    E-Print Network [OSTI]

    Camila A. Rezende; Fabio C. Bragança; Telma R. Doi; Lay-Theng Lee; Fernando Galembeck; François Boué

    2010-06-27T23:59:59.000Z

    The mechanical properties of non-vulcanized natural rubber and dialyzed natural rubber-clay nanocomposites have been studied by uniaxial deformations to evaluate the reinforcement efficiency of the clay. We show that while non-rubber molecules contribute to auto-reinforcement, removal of these molecules improves significantly the performance of clay as reinforcement agent. These mechanical properties are discussed in relation to morphological aspects of the clay characterized by TEM and SANS. The nanocomposites prepared by "latex-mixing" with aqueous dispersions of clay are found to contain completely exfoliated clay lamellae in coexistence with tactoids. Improved mechanical properties of the nanocomposites can be modeled by the high aspect ratio of exfoliated clay platelets coupled with immobilized rubber matrix. Interestingly, presence of tactoids does not appear to compromise the excellent reinforcement properties of the exfoliated platelets. At high deformations, strain-induced alignment of the clay exhibits anisotropic scattering, with anisotropy increasing with clay concentration and stretching.

  6. Lithophysal Rock Mass Mechanical Properties of the Repository Host Horizon

    SciTech Connect (OSTI)

    D. Rigby

    2004-11-10T23:59:59.000Z

    The purpose of this calculation is to develop estimates of key mechanical properties for the lithophysal rock masses of the Topopah Spring Tuff (Tpt) within the repository host horizon, including their uncertainties and spatial variability. The mechanical properties to be characterized include an elastic parameter, Young's modulus, and a strength parameter, uniaxial compressive strength. Since lithophysal porosity is used as a surrogate property to develop the distributions of the mechanical properties, an estimate of the distribution of lithophysal porosity is also developed. The resulting characterizations of rock parameters are important for supporting the subsurface design, developing the preclosure safety analysis, and assessing the postclosure performance of the repository (e.g., drift degradation and modeling of rockfall impacts on engineered barrier system components).

  7. Thermal/MechanicalThermal/Mechanical Properties of WoodProperties of Wood--PVCPVC

    E-Print Network [OSTI]

    .composites. Heat flow, heat capacity, andHeat flow, heat capacity, and enthalpyenthalpy Glass transition/Mechanical Analysis TechniquesThermal/Mechanical Analysis Techniques #12;Rubbery Leathery Viscous liquid Rigid (Semi

  8. Method of predicting mechanical properties of decayed wood

    DOE Patents [OSTI]

    Kelley, Stephen S.

    2003-07-15T23:59:59.000Z

    A method for determining the mechanical properties of decayed wood that has been exposed to wood decay microorganisms, comprising: a) illuminating a surface of decayed wood that has been exposed to wood decay microorganisms with wavelengths from visible and near infrared (VIS-NIR) spectra; b) analyzing the surface of the decayed wood using a spectrometric method, the method generating a first spectral data of wavelengths in VIS-NIR spectra region; and c) using a multivariate analysis to predict mechanical properties of decayed wood by comparing the first spectral data with a calibration model, the calibration model comprising a second spectrometric method of spectral data of wavelengths in VIS-NIR spectra obtained from a reference decay wood, the second spectral data being correlated with a known mechanical property analytical result obtained from the reference decayed wood.

  9. Epoxy Nanocomposites with Highly Exfoliated Clay: Mechanical Properties and Fracture Mechanisms

    E-Print Network [OSTI]

    George, Steven C.

    Epoxy Nanocomposites with Highly Exfoliated Clay: Mechanical Properties and Fracture Mechanisms Ke; Revised Manuscript Received November 9, 2004 ABSTRACT: Epoxy/clay nanocomposites with a better exfoliated and transmission electron microscopy (TEM). It was found that clay was highly exfoliated and uniformly dispersed

  10. Mechanical properties and fabric of the Punchbowl fault zone, California

    E-Print Network [OSTI]

    Chester, Frederick Michael

    1983-01-01T23:59:59.000Z

    MECHANICAL PROPERIIES AND FABRIC OF THE PUiVCHBOlv'L FAULT ZONE, CALIFORNIA A Thesis by FREDERICK MICHAEL CHESTER Subm-', tted to the Graduate College of Texas ABM University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1983 Major Subject: Geology MECHANICAL PROPERTIES AND FABRIC OF THE PUNCHBOWL FAULT ZONE, CALIFORNIA A Thesis by FREDERICK MICHAEL CHESTER Approved as to sty1e and content by: on . . an airman o ommittee) Me1vin edman...

  11. Exploration of mechanisms underlying the strain-rate-dependent mechanical property of single chondrocytes

    SciTech Connect (OSTI)

    Nguyen, Trung Dung; Gu, YuanTong, E-mail: yuantong.gu@qut.edu.au [School of Chemistry, Physics and Mechanical Engineering, Queensland University of Technology, Brisbane, Queensland (Australia)

    2014-05-05T23:59:59.000Z

    Based on the characterization by Atomic Force Microscopy, we report that the mechanical property of single chondrocytes has dependency on the strain-rates. By comparing the mechanical deformation responses and the Young's moduli of living and fixed chondrocytes at four different strain-rates, we explore the deformation mechanisms underlying this dependency property. We found that the strain-rate-dependent mechanical property of living cells is governed by both of the cellular cytoskeleton and the intracellular fluid when the fixed chondrocytes are mainly governed by their intracellular fluid, which is called the consolidation-dependent deformation behavior. Finally, we report that the porohyperelastic constitutive material model which can capture the consolidation-dependent behavior of both living and fixed chondrocytes is a potential candidature to study living cell biomechanics.

  12. MECHANICAL PROPERTY CHARACTERIZATION OF SOL-GEL DERIVED NANOMATERIALS

    E-Print Network [OSTI]

    Brinker, C. Jeffrey

    mechanical behavior of polysilicate aerogels, prepared using the sol-gel process. Two series of materials were prepared, derivatized with silylating agents, processed into coating solutions, and characterized properties of aerogel thin films were characterized. vi #12;Table of Contents Abstract

  13. Effects of elevated temperatures on mechanical properties of concrete containing

    E-Print Network [OSTI]

    North Texas, University of

    Effects of elevated temperatures on mechanical properties of concrete containing haematite and A. Beycioglu5 Concretes containing different proportions of haematite (15, 30, 45 and 60%) were of concretes were determined according to ASTM C39 and ASTM C469. A rule based Mamdani type fuzzy logic model

  14. Technical Note Evaluation of mechanical rock properties using a Schmidt

    E-Print Network [OSTI]

    Ze'ev, Reches

    Technical Note Evaluation of mechanical rock properties using a Schmidt Hammer O. Katza, b, c, *, Z, 91904, Israel b Geological Survey of Israel, 30 Malkhe Yisrael St., Jerusalem, 95501, Israel c Rock of concrete hardness [1], and was later used to estimate rock strength [2,3]. It con- sists of a spring

  15. Investigation of moisture effects on interfacial properties of an epoxy matrix composite by dynamic mechanical analysis 

    E-Print Network [OSTI]

    Wang, Jo-Yu

    1994-01-01T23:59:59.000Z

    properties of glass bead-epoxy composites by measuring mechanical properties obtained through dynamic mechanical testing. The viscoelastic material properties of glass bead-composites, including glassy and rubbery moduli and the loss tangent (tanb) were...

  16. Mechanical and tribological properties of ion beam-processed surfaces

    SciTech Connect (OSTI)

    Kodali, P.

    1998-01-01T23:59:59.000Z

    The intent of this work was to broaden the applications of well-established surface modification techniques and to elucidate the various wear mechanisms that occur in sliding contact of ion-beam processed surfaces. The investigation included characterization and evaluation of coatings and modified surfaces synthesized by three surface engineering methods; namely, beam-line ion implantation, plasma-source ion implantation, and DC magnetron sputtering. Correlation among measured properties such as surface hardness, fracture toughness, and wear behavior was also examined. This dissertation focused on the following areas of research: (1) investigating the mechanical and tribological properties of mixed implantation of carbon and nitrogen into single crystal silicon by beam-line implantation; (2) characterizing the mechanical and tribological properties of diamond-like carbon (DLC) coatings processed by plasma source ion implantation; and (3) developing and evaluating metastable boron-carbon-nitrogen (BCN) compound coatings for mechanical and tribological properties. The surface hardness of a mixed carbon-nitrogen implant sample improved significantly compared to the unimplanted sample. However, the enhancement in the wear factor of this sample was found to be less significant than carbon-implanted samples. The presence of nitrogen might be responsible for the degraded wear behavior since nitrogen-implantation alone resulted in no improvement in the wear factor. DLC coatings have low friction, low wear factor, and high hardness. The fracture toughness of DLC coatings has been estimated for the first time. The wear mechanism in DLC coatings investigated with a ruby slider under a contact stress of 1 GPa was determined to be plastic deformation. The preliminary data on metastable BCN compound coatings indicated high friction, low wear factor, and high hardness.

  17. Temperature dependent mechanical property testing of nitrate thermal storage salts.

    SciTech Connect (OSTI)

    Iverson, Brian DeVon; Broome, Scott Thomas; Siegel, Nathan Phillip

    2010-08-01T23:59:59.000Z

    Three salt compositions for potential use in trough-based solar collectors were tested to determine their mechanical properties as a function of temperature. The mechanical properties determined were unconfined compressive strength, Young's modulus, Poisson's ratio, and indirect tensile strength. Seventeen uniaxial compression and indirect tension tests were completed. It was found that as test temperature increases, unconfined compressive strength and Young's modulus decreased for all salt types. Empirical relationships were developed quantifying the aforementioned behaviors. Poisson's ratio tends to increase with increasing temperature except for one salt type where there is no obvious trend. The variability in measured indirect tensile strength is large, but not atypical for this index test. The average tensile strength for all salt types tested is substantially higher than the upper range of tensile strengths for naturally occurring rock salts.

  18. Mechanical and thermophysical properties of hot-pressed SYNROC B

    SciTech Connect (OSTI)

    Hoenig, C.L.; Newkirk, H.W.; Otto, R.A.; Brady, R.L.; Brown, A.E.; Ulrich, A.R.; Lum, R.C.

    1981-05-06T23:59:59.000Z

    The optimal SYNROC compositons for use with commercial waste are reviewed. Large amounts of powder (about 2.5 kg) were prepared by convention al ceramic operations to test the SYNROC concept on a processing scale. Samples, 15.2 cm in diameter, were hot pressed in graphite, and representative samples were cut for microstructural evaluations. Measured mechanical and thermophysical properties did not vary significantly as a function of sample location and were typical of titanate ceramic materials.

  19. On-Machine Sensors to Measure Paper Mechanical Properties

    E-Print Network [OSTI]

    Hall, M. S.

    and remanufacture would reduce water utilization and provide consequential environmental benefits. The ability to control the process to a mechanical property specification may enable the product to be produced with a lower basis weight and/or lower quality... testing and performance demonstration will be required to gain acceptance by the paper industry. ACKNOWLEDGEMENT This work has been supported by the U.S. Department of Energy (Contract No. DE-AC05 86CE40777) and by the member companies of IPST...

  20. Mechanical properties of thin-wall ductile iron

    SciTech Connect (OSTI)

    Schrems, Karol K.; Dogan, Omer N.; Hawk, Jeffrey A.; Druschitz, A.P. (Intermet Corp., Lynchburg, VA)

    2000-10-01T23:59:59.000Z

    The use of cast iron in automotive applications in this era of increasing fuel efficiency requires the ability to cast very thin sections (2-7 mm). Although thin-wall iron castings have been produced, difficulty arises in predicting the mechanical properties of these castings because mechanical behavior is closely related to thickness, which in turn is a direct consequence of the section cooling rate. Experiments relating casting thickness with ultimate tensile strength, elongation, reduction in area, and hardness were performed. An inverse relationship was found between ultimate tensile strength and thickness. Elongation was found to depend only on the thickness of the sample and approached zero as the thickness of the sample decreased below 1.5 mm. Percent reduction in area was found to depend linearly on thickness. Although average hardness also correlated with the inverse of thickness, it was not found to be a useful measure of ultimate tensile strength. The results of this study show that cooling rate of the thin wall casting very much affects the mechanical properties.

  1. Mechanical property evaluation of natural fiber coir composite

    SciTech Connect (OSTI)

    Harish, S. [Department of Mechanical and Aerospace Engineering, Arizona State University (United States); Michael, D. Peter [Department of Mechanical Engineering, College of Engineering, Guindy (India); Bensely, A. [Department of Mechanical Engineering, College of Engineering, Guindy (India)], E-mail: benzlee5@yahoo.com; Lal, D. Mohan [Department of Mechanical Engineering, College of Engineering, Guindy (India); Rajadurai, A. [Department of Production Engineering, Madras Institute of Technology (India)

    2009-01-15T23:59:59.000Z

    The fiber which serves as a reinforcement in reinforced plastics may be synthetic or natural. Past studies show that only artificial fibers such as glass, carbon etc., have been used in fiber-reinforced plastics. Although glass and other synthetic fiber-reinforced plastics possess high specific strength, their fields of application are very limited because of their inherent higher cost of production. In this connection, an investigation has been carried out to make use of coir, a natural fiber abundantly available in India. Natural fibers are not only strong and lightweight but also relatively very cheap. In the present work, coir composites are developed and their mechanical properties are evaluated. Scanning electron micrographs obtained from fractured surfaces were used for a qualitative evaluation of the interfacial properties of coir/epoxy and compared with glass fiber/epoxy. These results indicate that coir can be used as a potential reinforcing material for making low load bearing thermoplastic composites.

  2. Low-temperature mechanical properties of glass/epoxy laminates

    SciTech Connect (OSTI)

    Reed, R. P. [Cryogenic Materials, Inc., Boulder, CO 80305 (United States); Madhukar, M.; Thaicharoenporn, B. [Magnet Development Laboratory, Knoxville, TN 37996 (United States); Martovetsky, N. N. [US-ITER Project, Oak Ridge National Laboratory, Oak Ridge, TN 37830 (United States)

    2014-01-27T23:59:59.000Z

    Selected mechanical properties of glass/epoxy laminate candidates for use in the electrical turn and ground insulation of the ITER Central solenoid (CS) modules were measured. Short-beam shear and flexural tests have been conducted on various E-glass cloth weaves/epoxy laminates at 295 and 77 K. Types of glass weave include 1581, 7500, 7781, and 38050, which represent both satin and plain weaves. The epoxy, planned for use for vacuum-pressure impregnation of the CS module, consists of an anhydride-cured bisphenol F resin system. Inter-laminar shear strength, flexural elastic modulus, and flexural strength have been measured. The data indicate that these properties are dependent on the volume percent of glass. Short-beam shear strength was measured as a function of the span-to-thickness ratio for all laminates at 77 K. Comprehensive fractography was conducted to obtain the failure mode of each short-beam shear test sample.

  3. Mechanical properties of Devonian shales from the Appalachian Basin

    SciTech Connect (OSTI)

    Blanton, T.L.; Dischler; Patti, N.C.

    1981-09-30T23:59:59.000Z

    A prime objective of the current study has been to establish wherever possible regional or stratigraphic trends in the various properties required by stimulation research. Lithologically Devonian shales tend to fall into two categories: gray shales and organic-rich black shales. Two black/gray pairs, Huron/Hanover and Marcellus/Mahantango, were selected from four localities in Pennsylvania and Ohio for comprehensive testing. Over 130 experiments were run on these zones to determine elasticity, fracture properties, yield and ultimate strength, and ductility. The results of these tests and previous tests run on core from West Virginia and Kentucky provide a basis for the following conclusions about Devonian shale mechanical properties and their applications in stimulation research: elasticity of Devonian shale matrix material showed no strong trends with respect to either lithology, locality, or confining pressure. Gray shales tended to have a slightly higher Young's modulus than black shales, but the difference between the averages was less than the standard deviation of each average. Ultimate strength, yield strength, and ductility all increase with increasing confining pressure, which is typical for most rocks. Ultimate strength and yield strength tend to be higher for gray shales, whereas black shales tend to be more ductile. Tensile strength showed no particular trends either regionally or lithologically, whereas fracture energy seemed to have the most consistent trends of any material property measured. Black shales tended to have a higher fracture energy, and fracture energy for both black and gray shales tended to increase with depth of burial. Two promising topics for continued study are the effect of confining pressure on fracture energy and the effect of deformation rate on material properties. 16 figures, 9 tables.

  4. Mechanical Properties of Gels; Stress from Confined Fluids

    SciTech Connect (OSTI)

    George W. Scherer

    2009-12-01T23:59:59.000Z

    Abstract for Grant DE-FG02-97ER45642 Period: 1997-2002 Mechanical Properties of Gels 2002-2008 Stress from Confined Fluids Principal investigator: Prof. George W. Scherer Dept. Civil & Env. Eng./PRISM Eng. Quad. E-319 Princeton, NJ 08544 USA Recipient organization: Trustees of Princeton University 4 New South Princeton, NJ 08544 USA Abstract: The initial stage of this project, entitled Mechanical Properties of Gels, was dedicated to characterizing and explaining the properties of inorganic gels. Such materials, made by sol-gel processing, are of interest for fabrication of films, fibers, optical devices, advanced insulation and other uses. However, their poor mechanical properties are an impediment in some applications, so understanding the origin of these properties could lead to enhanced performance. Novel experimental methods were developed and applied to measure the stiffness and permeability of gels and aerogels. Numerical simulations were developed to reproduce the growth process of the gels, resulting in structures whose mechanical properties matched the measurements. The models showed that the gels are formed by the growth of relatively robust clusters of molecules that are joined by tenuous links whose compliance compromises the stiffness of the structure. Therefore, synthetic methods that enhance the links could significantly increase the rigidity of such gels. The next stage of the project focused on Stress from Confined Fluids. The first problem of interest was the enhanced thermal expansion coefficient of water that we measured in the nanometric pores of cement paste. This could have a deleterious effect on the resistance of concrete to rapid heating in fires, because the excessive thermal expansion of water in the pores of the concrete could lead to spalling and collapse. A series of experiments demonstrated that the expansion of water increases as the pore size decreases. To explain this behavior, we undertook a collaboration with Prof. Stephen Garofalini (Rutgers), who has developed the best simulations of water ever reported by use of molecular dynamics. Simulated heating of water in small pores provided quantitative agreement with experiments, and showed that the origin of the high expansion is the altered structure of water in the first two molecular layers adjacent to the pore wall. The final focus of the project was to understand the damage done by crystals growing in small pores. For example, the primary cause of damage to ancient monuments in the Mediterranean Basin is growth of salt crystals in the pores of the stone. Salt may enter stone as a result of capillary rise of groundwater, by leaching of mortar joints, deposition of marine spray, or reactions with atmospheric pollutants (such as oxides of nitrogen or sulfur). As the water evaporates, the salt solution becomes supersaturated and crystals precipitate. Stress results, because the salt usually repels the minerals in the pore walls. Our goal was to identify the factors contributing to the repulsion, so that we could develop a chemical treatment to reduce the repulsion and hence the stress. (We have recently demonstrated an effective treatment as part of a separately funded study.) In collaboration with Prof. Garofalini, molecular dynamics simulations have been done that correctly reproduce the structure of water around dissolved ions of sodium and chloride. We simulated the interaction between crystals of sodium chloride and quartz, and found that this particular system exhibits attractive forces, in agreement with experiment. The origin of the attraction is the orientation of dipolar water molecules near the surfaces of the crystals. Similar calculations now must be done in systems, such as potassium chloride and quartz, where the interaction is repulsive. This grant supported the education of two doctoral students, Hang-Shing Ma (Ph.D., 2002) and Melanie Webb (Ph.D. expected 2010), three post-doctoral researchers, Joachim Gross, Gudrun Reichenauer, and Shuangyan (Sonia) Xu, and five undergraduates (for senior theses or independent projects

  5. Energetic Particle Synthesis of Metastable Layers for Superior Mechanical Properties

    SciTech Connect (OSTI)

    Follstaedt, D.M.; Knapp, J.A.; Myers, S.M.; Dugger, M.T.; Friedmann, T.A.; Sullivan, J.P. [Sandia National Labs., Albuquerque, NM (United States); Monteiro, O.R.; Ager, J.W. III; Brown, I.G.; Christenson, T. [Lawrence Berkeley National Lab., CA (United States)

    1998-01-01T23:59:59.000Z

    Energetic particle methods have been used to synthesize two metastable layers with superior mechanical properties: amorphous Ni implanted with overlapping Ti and C, and amorphous diamond-like carbon (DLC) formed by vacuum-arc deposition or pulsed laser deposition. Elastic modulus, yield stress and hardness were reliably determined for both materials by fitting finite-element simulations to the observed layer/substrate responses during nanoindentation. Both materials show exceptional properties, i.e., the yield stress of amorphous Ni(Ti,C) exceeds that of hardened steels and other metallic glasses, and the hardness of DLC (up to 88 GPa) approaches that of crystalline diamond (approx. 100 GPa). Tribological performance of the layers during unlubricated sliding contact appears favorable for treating Ni-based micro-electromechanical systems: stick-slip adhesion to Ni is eliminated, giving a low coefficient of friction (approx. 0.3-0.2) and greatly reduced wear. We discuss how energetic particle synthesis is critical to forming these phases and manipulating their properties for optimum performance.

  6. 3.22 Mechanical Properties of Materials, Spring 2003

    E-Print Network [OSTI]

    Gibson, Lorna J.

    Phenomenology of mechanical behavior of materials at the macroscopic level. Relationship of mechanical behavior to material structure and mechanisms of deformation and failure. Topics include: elasticity, viscoelasticity, ...

  7. Mechanical properties and microstructure of pressureless sintered duophase sialon

    SciTech Connect (OSTI)

    Lee, Ran-Rong; Novich, B.E.; Franks, G.; Quellette, D. (Ceramics Process Systems Corp., Milford, MA (United States)); Ferber, M.K.; Hubbard, C.R.; More, K. (Oak Ridge National Lab., TN (United States))

    1991-01-01T23:59:59.000Z

    Duophase ({alpha}{prime}/{beta}{prime}) sialon is being developed for ceramic engine applications by using the Quickset{trademark} injection molding process, followed by pressureless sintering and a thermal treatment. The sialon had an average four-point flexural strength of 670 MPa at room temperature and 490 MPa at 1370{degree}C. It survived the flexural stress rupture test at 1300{degree}C and 340 MPa for 190 hours. X-ray diffraction (XRD) and transmission electron microscopy (TEM) characterization showed that crystallization of the grain boundary phase improved the high temperature flexural strength of this sialon material. The creep behavior was also found to be affected by the crystallized grain boundary phases. The formation of a yttrium aluminum garnet (YAG) phase and elongated grains yielded better creep resistance. The correlation between mechanical properties and microstructure is discussed. 13 refs., 7 figs.

  8. Mechanical Properties of Particulate Reinforced Aluminium Alloy Matrix Composite

    SciTech Connect (OSTI)

    Sayuti, M. [Faculty of Engineering, Malikussaleh University of Lhokseumawe, 24300 Aceh (Indonesia); Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Sulaiman, S.; Baharudin, B. T. H. T.; Arifin, M. K. A. [Department of Mechanical and Manufacturing Engineering, Faculty of Engineering, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Suraya, S.; Vijayaram, T. R.

    2011-01-17T23:59:59.000Z

    This paper discusses the mechanical properties of Titanium Carbide (TiC) particulate reinforced aluminium-silicon alloy matrix composite. TiC particulate reinforced LM6 alloy matrix composites were fabricated by carbon dioxide sand molding process with different particulate weight fraction. Tensile strength, hardness and microstructure studies were conducted to determine the maximum load, tensile strength, modulus of elasticity and fracture surface analysis have been performed to characterize the morphological aspects of the test samples after tensile testing. Hardness values are measured for the TiC reinforced LM6 alloy composites and it has been found that it gradually increases with increased addition of the reinforcement phase. The tensile strength of the composites increased with the increase percentage of TiC particulate.

  9. Mechanical properties and energy absorption characteristics of a polyurethane foam

    SciTech Connect (OSTI)

    Goods, S.H.; Neuschwanger, C.L.; Henderson, C.; Skala, D.M.

    1997-03-01T23:59:59.000Z

    Tension, compression and impact properties of a polyurethane encapsulant foam have been measured as a function of foam density. Significant differences in the behavior of the foam were observed depending on the mode of testing. Over the range of densities examined, both the modulus and the elastic collapse stress of the foam exhibited power-law dependencies with respect to density. The power-law relationship for the modulus was the same for both tension and compression testing and is explained in terms of the elastic compliance of the cellular structure of the foam using a simple geometric model. Euler buckling is used to rationalize the density dependence of the collapse stress. Neither tension nor compression testing yielded realistic measurements of energy absorption (toughness). In the former case, the energy absorption characteristics of the foam were severely limited due to the inherent lack of tensile ductility. In the latter case, the absence of a failure mechanism led to arbitrary measures of energy absorption that were not indicative of true material properties. Only impact testing revealed an intrinsic limitation in the toughness characteristics of the material with respect to foam density. The results suggest that dynamic testing should be used when assessing the shock mitigating qualities of a foam.

  10. High Temperature Mechanical Properties of Molybdenum Solid Solution Alloys

    SciTech Connect (OSTI)

    Charit, I.; Murty, K.L. [College of Engineering, North Carolina State University, Raleigh, NC 27695, (United States)

    2006-07-01T23:59:59.000Z

    Demanding material requirements for space nuclear power systems have called for the use of refractory alloys. Molybdenum alloys are such candidate materials because of their good mechanical properties at fairly high temperatures, low neutron capture cross-section, and superior resistance to the attack of liquid metals. However, conventional Mo alloys have low ductility at lower temperatures. Hence, there have been several attempts to improve their viability. One of those approaches has been to alloy Mo with various alloying additions in solid solution, most notably with rhenium (Re). In this study the high temperature deformation behavior of various Mo-X (X Re, W, Nb, Hf) alloys is reviewed. High temperature deformation data for these solid solution alloys are analyzed in the light of existing deformation theories. Alloys with both Class-M and -A type behavior are identified and thus, various mechanisms are found to operate. Sometimes data interpretation becomes difficult due to the presence of second phase particles. Results are compared with unalloyed Mo to bring out the importance of solid solution alloying. (authors)

  11. Copyright (to be inserted by Humphrey) Thermal and Dynamic-mechanical Properties of Wood-PVC

    E-Print Network [OSTI]

    Citation & Copyright (to be inserted by Humphrey) Thermal and Dynamic-mechanical Properties of Wood-PVC properties, maleation, thermal analysis, wood veneer, wood-PVC composites ABSTRACT The influence of maleation on thermal and dynamic-mechanical properties of wood-PVC composites was investigated in this study

  12. Changes in the Mechanical and Biochemical Properties of Aortic Tissue due to Cold Storage

    E-Print Network [OSTI]

    Zhang, Katherine Yanhang

    Changes in the Mechanical and Biochemical Properties of Aortic Tissue due to Cold Storage Ming Background. Temporary cold storage is a common procedure for preserving tissues for a short time be- fore; collagen; mechan- ical properties; arteries; cold storage; soft tissue; mechanical testing; vascular

  13. Physical and Mechanical Properties of Niobium for SRF Science and Technology

    SciTech Connect (OSTI)

    Ganapati Rao Myneni

    2006-10-31T23:59:59.000Z

    Optimized mechanical and physical properties of high purity niobium are crucial for obtaining high performance SRF particle beam accelerator structures consistently. This paper summarizes these important material properties for both high purity polycrystalline and single crystal niobium.

  14. Correlation of mechanical viscoelastic properties to microstructure of equine cortical bone tissue 

    E-Print Network [OSTI]

    Ayers, Andrew Kerr

    1995-01-01T23:59:59.000Z

    Dynamic Mechanical Analysis (DMA) has long been used as a method of determining viscoelastic mechanical properties of polymeric materials. More recently, DMA has been used for characterizing the fiber/matrix interface in composite materials...

  15. MECHANICAL PROPERTY CHARACTERIZATIONS AND PERFORMANCE MODELING OF SOFC SEALS

    SciTech Connect (OSTI)

    Koeppel, Brian J.; Vetrano, John S.; Nguyen, Ba Nghiep; Sun, Xin; Khaleel, Mohammad A.

    2008-03-26T23:59:59.000Z

    This study provides modeling tools for the design of reliable seals for SOFC stacks. The work consists of 1) experimental testing to determine fundamental properties of SOFC sealing materials, and 2) numerical modeling of stacks and sealing systems. The material tests capture relevant temperature-dependent physical and mechanical data needed by the analytical models such as thermal expansion, strength, fracture toughness, and relaxation behavior for glass-ceramic seals and other materials. Testing has been performed on both homogenous specimens and multiple material assemblies to investigate the effect of interfacial reactions. A viscoelastic continuum damage model for a glass-ceramic seal was developed to capture the nonlinear behavior of this material at high temperatures. This model was implemented in the MSC MARC finite element code and was used for a detailed analysis of a planar SOFC stack under thermal cycling conditions. Realistic thermal loads for the stack were obtained using PNNL’s in-house multiphysics solver. The accumulated seal damage and component stresses were evaluated for multiple thermal loading cycles, and regions of high seal damage susceptible to cracking were identified. Selected test results, numerical model development, and analysis results will be presented.

  16. Mechanical Properties of Aluminum Tailor Welded Blanks at Superplastic Temperatures

    SciTech Connect (OSTI)

    Davies, Richard W.; Vetrano, John S.; Smith, Mark T.; Pitman, Stan G.

    2002-10-06T23:59:59.000Z

    This paper describes an investigation of the mechanical properties of weld material in aluminum tailor welded blanks (TWB) at superplastic temperatures and discusses the potential application of TWBs in superplastic forming operations. Aluminum TWBs consist of multiple sheet materials of different thickness or alloy that are butt-welded together into a single, variable thickness blank. To evaluate the performance of the weld material in TWBs, a series of tensile tests were conducted at superplastic temperatures with specimens that contained weld material in the gage area. The sheet material used in the study was Sky 5083 aluminum alloy, which was joined to produce the TWBs by gas tungsten arc welding using an AA5356 filler wire. The experimental results show that, in the temperature range of 500?C to 550?C and at strain rates ranging from 10-4 sec-1 to 10-2 sec-1, the weld material has a higher flow stress and lower ductility than the monolithic sheet material. The weld material exhibited elongations of 40% to 60% under these conditions, whereas the monolithic sheet achieved 220% to 360% elongation. At the same temperatures and strain rates, the weld material exhibited flow stresses 1.3 to 4 times greater than the flow stress in the monolithic sheet. However, the weld material did show a substantial increase in the strain rate sensitivity and ductility when compared to the same material formed at room temperature.

  17. Hierarchical and size dependent mechanical properties of silica and silicon nanostructures inspired by diatom algae

    E-Print Network [OSTI]

    García, Andre Phillipé

    2010-01-01T23:59:59.000Z

    Biology implements fundamental principles that allow for attractive mechanical properties, as observed in biomineralized structures. For example, diatom algae contain nanoporous hierarchical silicified shells that provide ...

  18. 3.225 Electronic and Mechanical Properties of Materials, Summer 2002

    E-Print Network [OSTI]

    Gibson, Lorna J.

    2002-01-01T23:59:59.000Z

    Electrical, optical, magnetic, and mechanical properties of metals, semiconductors, ceramics and polymers. Discussion of roles of bonding, structure (crystalline, defect, energy band and microstructure) and composition in ...

  19. Determining the mechanical properties of equine laminar corium tissue 

    E-Print Network [OSTI]

    Hallab, Nadim James

    1991-01-01T23:59:59.000Z

    elastic orthotropic material. BACKGROUND Mechanical Testing of Biological Materials The field of biomechanics has long dealt with the issue of mechanically characterizing soft and hard tissue. Biological tissue has eluded well defined characterization... Toby Selcer for his assistance with the MTS testing system. TABLE OF CONTENTS ABSTRACT ACKNOWLEDGEMENTS, TABLE OF CONTENTS. . LIST OF TABLES. . LIST OF FIGURES. . INTRODUCTION. Motivation. Objectives. BACKGROUND. . Mechanical Testing...

  20. Passive film-induced stress and mechanical properties of a-Ti in methanol solution

    E-Print Network [OSTI]

    Volinsky, Alex A.

    Passive film-induced stress and mechanical properties of a-Ti in methanol solution Zhi Qin and film mechanical properties on a-Ti in methanol solution with varying water content was investigated. Film-induced stress in the methanol solution was measured by the flow stress differential method

  1. Mechanical Properties of Controlled Memory and Superelastic Nickel-Titanium Wires Used in the Manufacture

    E-Print Network [OSTI]

    Zheng, Yufeng

    Mechanical Properties of Controlled Memory and Superelastic Nickel-Titanium Wires Used was to investigate the structure and mechanical properties of newly devel- oped controlled memory (CM) nickel-titanium transformation behavior of both types of wires were examined by x-ray energy dispersive spectroscopy

  2. Mechanical properties of nanocrystalline and epitaxial TiN films on (100) silicon

    E-Print Network [OSTI]

    Wei, Qiuming

    Mechanical properties of nanocrystalline and epitaxial TiN films on (100) silicon H. Wang, A 2001) We investigated mechanical properties of TiN as a function of microstructure varying from nanocrystalline to single crystal TiN films deposited on (100) silicon substrates. By varying the substrate

  3. NUMERICAL MODELLING OF AUTOGENOUS HEALING AND RECOVERY OF MECHANICAL PROPERTIES IN ULTRA-HIGH

    E-Print Network [OSTI]

    Boyer, Edmond

    in the cementitious matrix can react with carbon dioxide dissolved in the water filling the crack. Autogenous healingNUMERICAL MODELLING OF AUTOGENOUS HEALING AND RECOVERY OF MECHANICAL PROPERTIES IN ULTRA into the crack and leads to a partial recovery of mechanical properties (Young's modulus, tensile strength

  4. Estimating cancellous bone properties of the rat from mechanical testing of the femoral neck 

    E-Print Network [OSTI]

    Groves, Jennifer Ann

    1998-01-01T23:59:59.000Z

    ESTIMATING CANCELLOIJS BONE PROPERTIES OF THE RAT FROM MECHANICAL TESTING OF THE FEMORAL NECK A Thesis by JENNIFER ANN GROVES Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 1998 Major Subject: Mechanical Engineering ESTIMATING CANCELLOUS BONE PROPERTIES OF THE RAT FROM MECHANICAL TESTING OF THE FEMORAL NECK A Thesis by JENNIFER ANN GROVES Submitted to Texas Ai8:M University...

  5. Multifunctional composites and structures with integrated mechanical and electromagnetic properties

    E-Print Network [OSTI]

    Amirkhizi, Alireza Vakil

    2006-01-01T23:59:59.000Z

    Mal, A. , 2004. Structural health monitoring. Mechanics 33,field of Structural Health Monitoring, or SHM. Researchersfor structural composites with in-situ health monitoring

  6. anisotropic mechanical properties: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    oxide coatings were deposited on low to investigate the microstructure of chromium oxide coatings. Varying oxygen flux changed the coating Volinsky, Alex A. 124 Mechanical...

  7. FERRITE STRUCTURE AND MECHANICAL PROPERTIES OF LOW ALLOY DUPLEX STEELS

    E-Print Network [OSTI]

    Hoel, R.H.

    2013-01-01T23:59:59.000Z

    nucleated precipitates in the ferrite phase of the base + Nbto Scripta Metal1urgica FERRITE STRUCTURE AND MECHANICALUniversity of Califomia. Ferrite Structure and Mechanical

  8. Optical Fiber Technique for In-Reactor Mechanical Properties Measurement

    SciTech Connect (OSTI)

    Robert S. Schley; Zilong Hua; David H. Hurley; Heng Ban

    2012-07-01T23:59:59.000Z

    In-reactor measurement of material properties is required for a better understanding of radiation effects on materials. We present an optical fiber based technique for measuring changes in elastic properties which involves exciting and measuring flexural vibrations in a thin cantilever beam. By exciting the beam and measuring the natural frequency, changes in the modulus of elasticity can be monitored. The technique is demonstrated by monitoring the elastic property changes of a beam fabricated from copper, as the copper undergoes recrystallization at elevated temperature.

  9. FERRITE STRUCTURE AND MECHANICAL PROPERTIES OF LOW ALLOY DUPLEX STEELS

    E-Print Network [OSTI]

    Hoel, R.H.

    2013-01-01T23:59:59.000Z

    and Properties of Dual-Phase Steels, R. A. Kot and J. W.Formable HSLA and Dual Phase Steels, A. T. Davenport, ed. ,Formable HSLA and Dual Phase Steels, A. T. Davenport, ed. ,

  10. Measuring the mechanical properties of the respiratory system in patients

    E-Print Network [OSTI]

    Hayden, Nancy J.

    the lungs such that their frequency content lies in a range above that encompassed by the regular's lungs. · Only system capable of convenient, ongoing assessment of respiratory mechanical function

  11. Optical method for determining the mechanical properties of a material

    DOE Patents [OSTI]

    Maris, Humphrey J. (Barrington, RI); Stoner, Robert J. (Duxbury, MA)

    1998-01-01T23:59:59.000Z

    Disclosed is a method for characterizing a sample, comprising the steps of: (a) acquiring data from the sample using at least one probe beam wavelength to measure, for times less than a few nanoseconds, a change in the reflectivity of the sample induced by a pump beam; (b) analyzing the data to determine at least one material property by comparing a background signal component of the data with data obtained for a similar delay time range from one or more samples prepared under conditions known to give rise to certain physical and chemical material properties; and (c) analyzing a component of the measured time dependent reflectivity caused by ultrasonic waves generated by the pump beam using the at least one determined material property. The first step of analyzing may include a step of interpolating between reference samples to obtain an intermediate set of material properties. The material properties may include sound velocity, density, and optical constants. In one embodiment, only a correlation is made with the background signal, and at least one of the structural phase, grain orientation, and stoichiometry is determined.

  12. Optical method for determining the mechanical properties of a material

    DOE Patents [OSTI]

    Maris, H.J.; Stoner, R.J.

    1998-12-01T23:59:59.000Z

    Disclosed is a method for characterizing a sample, comprising the steps of: (a) acquiring data from the sample using at least one probe beam wavelength to measure, for times less than a few nanoseconds, a change in the reflectivity of the sample induced by a pump beam; (b) analyzing the data to determine at least one material property by comparing a background signal component of the data with data obtained for a similar delay time range from one or more samples prepared under conditions known to give rise to certain physical and chemical material properties; and (c) analyzing a component of the measured time dependent reflectivity caused by ultrasonic waves generated by the pump beam using the at least one determined material property. The first step of analyzing may include a step of interpolating between reference samples to obtain an intermediate set of material properties. The material properties may include sound velocity, density, and optical constants. In one embodiment, only a correlation is made with the background signal, and at least one of the structural phase, grain orientation, and stoichiometry is determined. 14 figs.

  13. Compaction Effects on Uniformity, Moisture Diffusion, and Mechanical Properties of Asphalt Pavements

    E-Print Network [OSTI]

    Kassem, Emad Abdel-Rahman Ahmed

    2011-08-08T23:59:59.000Z

    in gyratory specimens were related to the mixture mechanical properties measured using the Overlay and Hamburg tests. The second part of this study focused on studying the relationship between air void distribution and moisture diffusion. A laboratory test...

  14. Effect of high temperature on mechanical and physical properties of lightweight cement

    E-Print Network [OSTI]

    North Texas, University of

    Effect of high temperature on mechanical and physical properties of lightweight cement based are used for fire resistance applications. Concrete with vermiculite can be used as cement based refractory. Keywords: Expanded vermiculite, Lightweight concrete, Cement based refractory Introduction Concrete

  15. Characterization of the viscoelastic properties of thin-film materials using dynamic-mechanical testing techniques 

    E-Print Network [OSTI]

    Biskup, Bruce Allen

    1994-01-01T23:59:59.000Z

    An investigation into the use of dynamic mechanical analysis to characterize the viscoelastic properties of thin film materials is presented. The methodology was investigated using polyethylene films used on high altitude research balloons. Time...

  16. Effects of mechanical properties and surface friction on elasto-plastic sliding contact

    E-Print Network [OSTI]

    Suresh, Subra

    Effects of mechanical properties and surface friction on elasto-plastic sliding contact S and many recent computational studies have established quantitative relationships between elasto-plastic systematically quantified the effect of the plastic deformation characteristics on the frictional sliding

  17. An instrument for high-throughput measurements of fiber mechanical properties

    E-Print Network [OSTI]

    Kristofek, Grant William, 1980-

    2005-01-01T23:59:59.000Z

    In this thesis, an instrument is designed and constructed for the purpose of measuring the mechanical properties of single fibers. The instrument is intended to provide high throughput measurement of single fiber geometric ...

  18. CRYSTALLOGRAPHIC PROPERTIES AND MECHANICAL BEHAVIOR OF TITANIUM HYDRIDE LAYERS GROWN ON TITANIUM IMPLANTS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    CRYSTALLOGRAPHIC PROPERTIES AND MECHANICAL BEHAVIOR OF TITANIUM HYDRIDE LAYERS GROWN ON TITANIUM, Switzerland Keywords: SLA treated titanium - bone-anchored dental implants - transmission and scanning electron microscopy - titanium hydride sub-surface layer - epitaxy Abstract Commercially pure titanium

  19. ON THE USE OF DIGITAL IMAGE CORRELATION TO ANALYZE THE MECHANICAL PROPERTIES OF BRITTLE MATRIX COMPOSITES

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    for a ceramic-based braze that can be used to joint ceramics of ceramic-matrix composites. Different strategiesON THE USE OF DIGITAL IMAGE CORRELATION TO ANALYZE THE MECHANICAL PROPERTIES OF BRITTLE MATRIX

  20. EARLY-AGE CRACKING REVIEW: MECHANISMS, MATERIAL PROPERTIES,

    E-Print Network [OSTI]

    Bentz, Dale P.

    ://cementbarriers.org/ and Savannah River National Laboratory website: http://srnl.doe.gov #12;Early-Age Cracking Review: Mechanisms Commission (NRC), the National Institute of Standards and Technology (NIST), the Savannah River National of work performed in part under that contract. This report was prepared in support of the Savannah River

  1. Mechanical Properties and Radiation Tolerance of Metallic Multilayers

    E-Print Network [OSTI]

    Li, Nan

    2011-08-08T23:59:59.000Z

    and high fluence He ion irradiation conditions. This dissertation focuses on the investigation of mechanical and radiation responses of Al/Nb and Fe/W multilayers. Radiation induced microstructural evolution in Cu and Cu/Mo multilayer films are briefly...

  2. Method of determining elastic and plastic mechanical properties of ceramic materials using spherical indenters

    DOE Patents [OSTI]

    Adler, Thomas A. (Corvallis, OR)

    1996-01-01T23:59:59.000Z

    The invention pertains a method of determining elastic and plastic mechanical properties of ceramics, intermetallics, metals, plastics and other hard, brittle materials which fracture prior to plastically deforming when loads are applied. Elastic and plastic mechanical properties of ceramic materials are determined using spherical indenters. The method is most useful for measuring and calculating the plastic and elastic deformation of hard, brittle materials with low values of elastic modulus to hardness.

  3. Effects of simulated microgravity on vasoconstrictor and mechanical properties of the rat abdominal aorta

    E-Print Network [OSTI]

    Papadopoulos, Anthony

    2002-01-01T23:59:59.000Z

    EFFECTS OF SIMULATED MICROGRAVITY ON VASOCONSTRICTOR AND MECHANICAL PROPERTIES OF THE RAT ABDOMINAL AORTA A Thesis by ANTHONY PAPADOPOULOS Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 2002 Major Subject: Biomedical Engineering EFFECTS OF SIMULATED MICROGRAVITY ON VASOCONSTRICTOR AND MECHANICAL PROPERTIES OF THE RAT ABDOMINAL AORTA A Thesis by ANTHONY PAPADOPOULOS Submitted...

  4. LAKE STATES AS~EN REPORT NO. 7 .. MECHANICAL PROPERTIES. .OF ASPEN

    E-Print Network [OSTI]

    _.j LAKE STATES AS~EN REPORT NO. 7 .·. MECHANICAL PROPERTIES. .OF ASPEN BY R. P. A. JOHNSON been. increasing interest in aspen ,(Populus tremuloides) in the Lak.~ Stat-es,, its availability and supp;Ly, properties and ,uses, and management. Aspen is a tree of primary importance in , 20 million

  5. JOURNAL OF MICROELECTROMECHANICAL SYSTEMS, VOL. 6, NO. 4, DECEMBER 1997 307 Magnetic and Mechanical Properties

    E-Print Network [OSTI]

    Properties of Micromachined Strontium Ferrite/Polyimide Composites Laure K. Lagorce and Mark G. Allen, Member, IEEE Abstract--In this work, strontium ferrite/polyimide composite thin films are fabricated- oxydianiline/metaphenylene diamine polyimide matrix. Magnetic, mechanical, and processability properties

  6. Correlating mechanical properties of cancellous bone in the rat with various density measures 

    E-Print Network [OSTI]

    Ramaswamy, Ramya

    2004-09-30T23:59:59.000Z

    , and to correlate the mechanical properties of the rodent cancellous bone with the various density measures. Analytical studies were made to assess the effect of the size and shape of the platen based on the values from mechanical testing of the cancellous bone...

  7. Microstructure and mechanical properties of Ti-35Nb-6Ta alloy after thermomechanical treatment

    SciTech Connect (OSTI)

    Malek, J., E-mail: jardamalek@seznam.cz [UJP PRAHA a.s., Nad Kaminkou 1345, 156 10 Praha-Zbraslav (Czech Republic); CTU in Prague, Faculty of Mechanical Engineering, Department of Materials Science and Engineering, Karlovo Namesti 13, 121 35 Praha 2 (Czech Republic); Hnilica, F.; Vesely, J. [UJP PRAHA a.s., Nad Kaminkou 1345, 156 10 Praha-Zbraslav (Czech Republic); Smola, B. [Charles University in Prague, Faculty of Mathematics and Physics, Department of Physics of Materials, Ke Karlovu 5, 121 16 Praha 2 (Czech Republic); Bartakova, S.; Vanek, J. [St. Anne's University Hospital Brno, Pekarska 53, 656 91 Brno (Czech Republic)

    2012-04-15T23:59:59.000Z

    The influence of thermo-mechanical treatment on microstructure and mechanical properties of T-35Nb-6Ta has been studied. The thermo-mechanical treatment was chosen to correspond to the production of wire with suitable mechanical properties for dental implants. After casting the alloy was hot forged (700-900 Degree-Sign C), solution treated (850 Degree-Sign C/30 min, water quenched) and cold swaged (reductions up to 91%). The annealing (700 Degree-Sign C/3 h/furnace) or aging (450 Degree-Sign C/8 h/furnace) was used as final heat treatment. The microstructure was studied by using light microscopy, scanning electron microscopy, transmission electron microscopy and XRD analysis. Cold swaging introduces microstructure consisting of highly deformed {beta}-phase grains with dislocation tangles and twins, which ensures high tensile strength about 820 MPa, low Young's modulus ({approx} 50 GPa) and good ductility {approx} 10%. Subsequent aging increases tensile strength (1000 MPa) as well as Young's modulus (75 GPa) without diminishing ductility. Annealing at 700 Degree-Sign C slightly decreases tensile strength (730 MPa) and increases the ductility and Young's modulus (17% and 62 GPa respectively). The mechanical properties attained recommend the thermo-mechanical treatment for production of wires for dental implants. - Highlights: Black-Right-Pointing-Pointer Ti35Nb6Ta alloy prepared via arc melting. Black-Right-Pointing-Pointer Thermo mechanical treatment. Black-Right-Pointing-Pointer Microstructural changes. Black-Right-Pointing-Pointer Mechanical properties.

  8. The Mechanical and Tribological Properties or Ion Implanted Ceramics

    E-Print Network [OSTI]

    Bull, Stephen John

    1988-06-17T23:59:59.000Z

    by Wei et al (1987a. b) has shown that ion beam mixing of some ceramic discs with Ti, Ni or Co can result in reduced coefficients of friction at 800°C in a simulated diesel exhaust environment. 1.1.3 Oxidation and Corrosion Surface films have long... ions and defects below the surface to be determined both qualitatively and quantitatively. This has an important bearing on the other surface property changes produced by ion implantation discussed in the next chapter. 2.1 The Stopping of Ions...

  9. Determining the mechanical properties of equine laminar corium tissue

    E-Print Network [OSTI]

    Hallab, Nadim James

    1991-01-01T23:59:59.000Z

    section through the central hoof but from four distinct proximal to distal locations. The elastic modulus ranges from 0. 36 to 2. 3 x 103 psi and the ultimate strength ranges from 109 to 646 psi, A regional variation in these properties has also been... and the epidermal regions. Ten images of adjacent sides of a single sample were taken and the preliminary results are encouraging. The uniaxial modulus determined from the crosshead load-displacement data for this specimen was 1348 psi, whereas the dermal region...

  10. Machine Learning for Quantum Mechanical Properties of Atoms in Molecules

    E-Print Network [OSTI]

    Rupp, Matthias; von Lilienfeld, O Anatole

    2015-01-01T23:59:59.000Z

    We introduce machine learning models of quantum mechanical observables of atoms in molecules. Instant out-of-sample predictions for proton and carbon nuclear chemical shifts, atomic core level excitations, and forces on atoms reach accuracies on par with density functional theory reference. Locality is exploited within non-linear regression via local atom-centered coordinate systems. The approach is validated on a diverse set of 9k small organic molecules. Linear scaling is demonstrated for saturated polymers with up to sub-mesoscale lengths.

  11. Physical and mechanical properties of bituminous mixtures containing oil shales

    SciTech Connect (OSTI)

    Katamine, N.M.

    2000-04-01T23:59:59.000Z

    Rutting of bituminous surfaces on the Jordanian highways is a recurring problem. Highway authorities are exploring the use of extracted shale oil and oil shale fillers, which are abundant in Jordan. The main objectives of this research are to investigate the rheological properties of shale oil binders (conventional binder with various percentages of shale oil), in comparison with a conventional binder, and to investigate the ability of mixes to resist deformation. The latter is done by considering three wearing course mixes containing three different samples of oil shale fillers--which contained three different oil percentages--together with a standard mixture containing limestone filler. The Marshall design method and the immersion wheel tracking machine were adopted. It was concluded that the shale oil binders displayed inconsistent physical properties and therefore should be treated before being used. The oil shale fillers have provided mixes with higher ability to resist deformation than the standard mix, as measured by the Marshall quotients and the wheel tracking machine. The higher the percentages of oil in the oil shale fillers, the lower the ability of the mixes to resist deformation.

  12. Radiation-induced mechanical property changes in filled rubber

    SciTech Connect (OSTI)

    Maiti, A.; Weisgraber, T. H.; Gee, R. H.; Small, W.; Alviso, C. T.; Chinn, S. C.; Maxwell, R. S. [Lawrence Livermore National Laboratory, Livermore, CA 94550 (United States)

    2011-06-15T23:59:59.000Z

    In a recent paper we exposed a filled elastomer to controlled radiation dosages and explored changes in its cross-link density and molecular weight distribution between network junctions [A. Maiti et al., Phys. Rev. E 83, 031802 (2011)]. Here we report mechanical response measurements when the material is exposed to radiation while being under finite nonzero strain. We observe interesting hysteretic behavior and material softening representative of the Mullins effect, and materials hardening due to radiation. The net magnitude of the elastic modulus depends upon the radiation dosage, strain level, and strain-cycling history of the material. Using the framework of Tobolsky's two-stage independent network theory we develop a model that can quantitatively interpret the observed elastic modulus and its radiation and strain dependence.

  13. Mechanical properties of structural amorphous steels: Intrinsic correlations, conflicts, and optimizing strategies

    SciTech Connect (OSTI)

    Liu, Z. Q., E-mail: liuzq@imr.ac.cn; Zhang, Z. F., E-mail: zhfzhang@imr.ac.cn [Shenyang National Laboratory for Materials Science, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016 (China)

    2013-12-28T23:59:59.000Z

    Amorphous steels have demonstrated superior properties and great potentials for structural applications since their emergence, yet it still remains unclear about how and why their mechanical properties are correlated with other factors and how to achieve intended properties by designing their compositions. Here, the intrinsic interdependences among the mechanical, thermal, and elastic properties of various amorphous steels are systematically elucidated and a general trade-off relation is exposed between the strength and ductility/toughness. Encouragingly, a breakthrough is achievable that the strength and ductility/toughness can be simultaneously improved by tuning the compositions. The composition dependences of the properties and alloying effects are further analyzed thoroughly and interpreted from the fundamental plastic flow and atomic bonding characters. Most importantly, systematic strategies are outlined for optimizing the mechanical properties of the amorphous steels. The study may help establish the intrinsic correlations among the compositions, atomic structures, and properties of the amorphous steels, and provide useful guidance for their alloy design and property optimization. Thus, it is believed to have implications for the development and applications of the structural amorphous steels.

  14. A COMPARISON OF THE MICROSTRUCTURE AND MECHANICAL PROPERTIES OF 300-M STEEL MANUFACTURED BY THE VACUUM ARC REMELT AND THE ELECTROSLAG REMELT PROCESSES

    E-Print Network [OSTI]

    Lechtenberg, Thomas A.

    2011-01-01T23:59:59.000Z

    AND MECHANICAL PROPERTIES OF 300~M STEEL MANUFACTURED BY THEAND MECHANICAL PROPERTIES OF 300~M STEEL MANUFACTURED BY THEArc Remelt (VAR) 300-M steel were measured, These were

  15. Microstructural Characterization of the Chemo-mechanical Behavior of Asphalt in Terms of Aging and Fatigue Performance Properties

    E-Print Network [OSTI]

    Allen, Robert Grover

    2013-03-27T23:59:59.000Z

    The study of asphalt chemo-mechanics requires a basic understanding of the physical properties and chemical composition of asphalt and how these properties are linked to changes in performance induced by chemical modifications. This work uniquely...

  16. Use of Plasmon Spectroscopy to Evaluate the Mechanical Properties of Materials at the Nanoscale

    E-Print Network [OSTI]

    Howe, James M.

    Use of Plasmon Spectroscopy to Evaluate the Mechanical Properties of Materials at the Nanoscale, University of Virginia, Charlottesville, VA 22904-4745, USA Abstract: Relationships between volume plasmon of available data, correlations between the volume plasmon energy, Ep, Young's modulus, Ym, bulk modulus, Bm

  17. Journal of Biomechanics 35 (2002) 483490 Mechanical properties of brain tissue in tension

    E-Print Network [OSTI]

    Frey, Pascal

    tissue mechanical properties may find applications, for example, in a surgical robot control system Institute of Advanced Industrial Science and Technology (AIST), 1­2 Namiki, Tsukuba, Ibaraki, 305 in robotics technol- ogy, especially the emergence of automatic surgical tools and robots (e.g. Brett et al

  18. Mechanical Properties of Al-based Amorphous Alloy Ribbons Chun-Kuo Huang & John J. Lewandowski

    E-Print Network [OSTI]

    Rollins, Andrew M.

    for structural materials. Significant interest has arisen in amorphous aluminum alloys in recent years because MATERIALS FATIGUE DUCTILY TEST Amorphous aluminum alloys Al alloys Ti alloys Mg alloys Steels InhomogeneousMechanical Properties of Al-based Amorphous Alloy Ribbons Chun-Kuo Huang & John J. Lewandowski

  19. Effect of Sensitization on the Microstructure and the Mechanical Properties of 5xxx Aluminum Alloys

    E-Print Network [OSTI]

    Rollins, Andrew M.

    Effect of Sensitization on the Microstructure and the Mechanical Properties of 5xxx Aluminum Alloys) ABSTRACT 5xxx aluminum alloys are typically used for storage tanks, pressure vessels, and marine service conditions. EXPERIMENTAL Materials Commercial 5456 (H116) and 5083 (H116) aluminum alloys Commercial 5456

  20. Mechanical Properties of Sodium and Potassium Activated Metakaolin-Based Geopolymers 

    E-Print Network [OSTI]

    Kim, Hyunsoo

    2011-10-21T23:59:59.000Z

    on their chemical composition. The Na-GPs with ratio 3 have a highest compressive strength and Young‘s modulus of 39 MPa and 7.9 GPa, respectively. The results of mechanical testing are discussed in more detail in this thesis and linked to structural properties...

  1. TRANSMISSION WELDING OF GLASSES BY FEMTOSECOND LASER: STRUCTURAL AND MECHANICAL PROPERTIES

    E-Print Network [OSTI]

    Yao, Y. Lawrence

    TRANSMISSION WELDING OF GLASSES BY FEMTOSECOND LASER: STRUCTURAL AND MECHANICAL PROPERTIES Paper M processing parameters enables transmission welding. The morphology of the weld cross section was studied of the weld seams were studied through spatially resolved nanoindentation, and indentation fracture analysis

  2. Mechanical Properties of 3C-SiC Films for MEMS Applications Jayadeep Deva Reddy1

    E-Print Network [OSTI]

    Volinsky, Alex A.

    . A detailed study of the mechanical properties of single crystal and polycrystalline 3C-SiC films grown on Si substrates was performed by means of nanoindentation using a Berkovich diamond tip. The thickness of both the single and polycrystalline SiC films was around 1-2 µm. Under indentation loads below 500 µN both films

  3. 3C-SiC Films on Si for MEMS Applications: Mechanical Properties , G. Kravchenko2

    E-Print Network [OSTI]

    Volinsky, Alex A.

    diamond tip. These results indicate that polycrystalline SiC thin films are attractive for MEMS. In addition, poly-crystalline 3C- SiC was also grown on (100)Si so that a comparison with monocrystaline 3C-SiC, also grown on (100)Si, could be made. The mechanical properties of single crystal and polycrystalline 3

  4. Atomistic simulations of structures and mechanical properties of polycrystalline diamond: Symmetrical S001< tilt grain boundaries

    E-Print Network [OSTI]

    Brenner, Donald W.

    Atomistic simulations of structures and mechanical properties of polycrystalline diamond for diamond to deposit as a polycrystalline film with a high density of grain boundaries and related defects structures and energies of symmetrical 001 tilt grain boundaries GB's in diamond have been calculated over

  5. Weathering Effects on Mechanical Properties of Recycled HDPE Based Plastic Lumber

    E-Print Network [OSTI]

    Weathering Effects on Mechanical Properties of Recycled HDPE Based Plastic Lumber Jennifer K. Lynch recycled plastic lumber (RPL) decking was exposed to the environment for eleven years. The weathering in the construction of the deck were a commingled recycled plastic material referred to as curbside tailings, NJCT

  6. Mechanical properties and corrosion behavior of materials exposed to an experimental, atmospheric fluidized-bed combustor

    SciTech Connect (OSTI)

    Ganesan, P.; Sagues, A.; Sethi, V.

    1984-06-01T23:59:59.000Z

    A joint materials test program developed by the Institute for Mining and Minerals Research (IMMR) and the Tennessee Valley Authority (TVA) involved the postexposure mechanical properties and corrosion behavior of candidate structural materials in an experimental, atmospheric fluidized-bed combustor (AFBC). This combustor was operated by Accurex Corporation at Research Triangle Park, North Carolina, under the direction of TVA. The materials studied were Type 304, Type 310, and INCOLOY alloy 800 in the form of disc coupons with and without crevice configurations. Type 304 was also used for mechanical property measurements. The alloys were exposed to the combustor environment at about840/sup 0/C for approximately 330 hours. The ranking in terms of decreasing weight loss was: (1) Type 304, (2) Type 310, and (3) INCOLOY alloy 800. The presence of tight crevices did not enhance the corrosion rate. In addition, the corrosion rates, based on the weight loss (typically 1 to 6 mpy), indicated that the alloys performed reasonably well when considering materials wastage. However, optical microscopy observations showed intergranular corrosion penetration in INCOLOY alloy 800 and Type 304. The mechanical properties of Type 304 were inferior to the unexposed alloy. A comparison of the data obtained from the combustor-exposed 304ss tensile samples with data from control samples exposed in vacuum to a similar thermal history indicated that the chemistry of the AFBC environment did not play a major role in the observed degradation of the mechanical properties.

  7. Fabrication and mechanical properties of PLA/HA composites: A study of in vitro degradation

    E-Print Network [OSTI]

    Ritchie, Robert

    Fabrication and mechanical properties of PLA/HA composites: A study of in vitro degradation J perspective, the in vitro degradation behavior of such composites manufactured using a simple hot due to the degradation of the polymer phase. The degradation is more pronounced in samples with larger

  8. Strain-Induced Crystallization and Mechanical Properties of Functionalized Graphene Sheet-Filled Natural Rubber

    E-Print Network [OSTI]

    Aksay, Ilhan A.

    -Filled Natural Rubber Bulent Ozbas,1 * Shigeyuki Toki,2 Benjamin S. Hsiao,2 Benjamin Chu,2 Richard A. Register,1) on the mechanical properties and strain-induced crystallization of natural rubber (NR) are investigated. FGSs­723, 2012 KEYWORDS: composites; crystallization; graphene; rubber; WAXS INTRODUCTION Natural rubber (NR

  9. Mechanical and electrical property improvement in CNT/Nylon composites through drawing and stretching

    E-Print Network [OSTI]

    Zhu, Yuntian T.

    . Carbon nanotubes A. Nanocomposites A. Polymer­matrix composites (PMCs) B. Mechanical properties B the importance of straightening and aligning CNTs in improving the composite strength and electrical conductivity by polymer [8]. The most significant component in these composites is the CNT fiber. Techniques for making

  10. Mechanical Properties of Growing Melanocytic Nevi and the Progression to Melanoma

    E-Print Network [OSTI]

    Sethna, James P.

    Mechanical Properties of Growing Melanocytic Nevi and the Progression to Melanoma Alessandro Taloni, Italy Abstract Melanocytic nevi are benign proliferations that sometimes turn into malignant melanoma that osmotic stress and collagen inhibit growth in primary melanoma cells while the effect is much weaker

  11. Phase Transformation Behavior and Mechanical Properties of Thermomechanically Treated K3XF Nickel-Titanium

    E-Print Network [OSTI]

    Zheng, Yufeng

    Phase Transformation Behavior and Mechanical Properties of Thermomechanically Treated K3XF Nickel-Titanium of thermomechanically treated K3XF (SybronEndo, Orange, CA) nickel-titanium instruments in relation to their phase composition was determined by scan- ning electron microscopy with X-ray energy-dispersive spectrometric

  12. Ultrafast MR Grid-Tagging Sequence for Assessment of Local Mechanical Properties of the Lungs

    E-Print Network [OSTI]

    Napadow, Vitaly

    Ultrafast MR Grid-Tagging Sequence for Assessment of Local Mechanical Properties of the Lungs Qun in MR imaging of lung parenchyma. In this study, a fast MR grid-tagging technique is described deformation of the lung. Quantitative analysis of the data shows that this method is capable of assessing

  13. Effects of Thermal Aging on the Mechanical Properties of a Porous-Matrix Ceramic Composite

    E-Print Network [OSTI]

    Zok, Frank

    Effects of Thermal Aging on the Mechanical Properties of a Porous-Matrix Ceramic Composite Eric A of 1000­1200°C in air. The composite of interest derives its damage tolerance from a highly porous matrix, precluding the need for an interphase at the fiber­matrix boundary. The key issue in- volves the stability

  14. STRUCTURE-MECHANICAL PROPERTY RELATIONSHIPS IN A BIOLOGICAL CERAMIC-POLYMER COMPOSITE: NACRE

    E-Print Network [OSTI]

    Aksay, Ilhan A.

    171 STRUCTURE-MECHANICAL PROPERTY RELATIONSHIPS IN A BIOLOGICAL CERAMIC-POLYMER COMPOSITE: NACRE, a laminated ceramic- polymer biocompositefound in seashell. Four-pointbending strength and three-point bend and ultramicrotomedsections with and without the intactarago- nite platelets. We found that the organic matrix is indeed

  15. Thermal and mechanical properties of EPDM/PP + thermal shock-resistant ceramic composites

    E-Print Network [OSTI]

    North Texas, University of

    the polymer matrix. The brittleness, B, decreases upon surface modification of the ceramic. The highest valueThermal and mechanical properties of EPDM/PP + thermal shock-resistant ceramic composites Witold-scale ceramic powder. To overcome the difficulty of particles dispersion and adhe- sion, the filler was modified

  16. Effects of Creep and Cyclic Loading on the Mechanical Properties and Failure of Human Achilles Tendons

    E-Print Network [OSTI]

    Stanford University

    underwent creep test- ing at constant stresses from 35 to 75 MPa. Another 25 tendons underwent sinusoidal slope of the force versus displacement curve for individual loading cycles.20,21 For the creep testsEffects of Creep and Cyclic Loading on the Mechanical Properties and Failure of Human Achilles

  17. 3.22 Mechanical Properties of Materials Test 2: Viscoelasticity and Plasticity

    E-Print Network [OSTI]

    Goldwasser, Shafi

    are allowed to bring one 8.5" x 11" sheet into the test. 1. The creep behaviour of polyethylene is given3.22 Mechanical Properties of Materials Test 2: Viscoelasticity and Plasticity April 25, 2002 You by the creep compliance data in the table below. Creep compliance of Polyethylene t (hours) J(t) (psi-1) 0 0

  18. Studying some mechanical properties of MgO with used neon bulb glass

    SciTech Connect (OSTI)

    Issa, Tarik Talib [University of Baghdad, College of science physic department , Material Science group (Iraq); Khaleel, Saba Mahdi [Ministry of Industry and Minerals,Commission for Research And Industrial Development ,Chemical and Petrochemical Research Center, Baghdad (Iraq); Abdul Kareem, Noura Ammar [Ministry of Industry and Minerals, Commission for Research And Industrial Development ,Chemical and Petrochemical Research Center, Baghdad (Iraq)

    2013-12-16T23:59:59.000Z

    Ceramic compact of MgO +WT% of UNBG were sintered at different sintering temperature (700, 900, 1100, 1300)°c, under static air for 3 hours. X-ray diffraction and some mechanical properties were conducted. The maximum sintered density, compression; fracture strength and hardness were indicated for the compilation of MgO ?20 WT % UNBG, sintered at 1300 °c.

  19. Characterization of mechanical properties of aluminum 3003, 6061 and 7075 subjected to equal channel angular extrusion

    E-Print Network [OSTI]

    Mirmira, Srinivas Rangarao

    1995-01-01T23:59:59.000Z

    "xl"x6" billets of aluminum alloys 3003, 6061 and 7075 and copper 101, and the effects of processing parameters (number of passes, route. deformation temperature and strain rate) on the mechanical properties (and resistivity for copper 101) has been...

  20. Influence of different processing techniques on the mechanical properties of used tires in embankment construction

    SciTech Connect (OSTI)

    Edincliler, Ayse, E-mail: aedinc@boun.edu.t [Department of Earthquake Engineering, Kandilli Observatory and Earthquake Research Institute, Bogazici University, Cengelkoy, 34684 Istanbul (Turkey); Baykal, Goekhan; Saygili, Altug [Civil Engineering Department, Bogazici University, 34342 Istanbul (Turkey)

    2010-06-15T23:59:59.000Z

    Use of the processed used tires in embankment construction is becoming an accepted way of beneficially recycling scrap tires due to shortages of natural mineral resources and increasing waste disposal costs. Using these used tires in construction requires an awareness of the properties and the limitations associated with their use. The main objective of this paper is to assess the different processing techniques on the mechanical properties of used tires-sand mixtures to improve the engineering properties of the available soil. In the first part, a literature study on the mechanical properties of the processed used tires such as tire shreds, tire chips, tire buffings and their mixtures with sand are summarized. In the second part, large-scale direct shear tests are performed to evaluate shear strength of tire crumb-sand mixtures where information is not readily available in the literature. The test results with tire crumb were compared with the other processed used tire-sand mixtures. Sand-used tire mixtures have higher shear strength than that of the sand alone and the shear strength parameters depend on the processing conditions of used tires. Three factors are found to significantly affect the mechanical properties: normal stress, processing techniques, and the used tire content.

  1. Effects of temperature and strain rate on the mechanical properties of silicene

    SciTech Connect (OSTI)

    Pei, Qing-Xiang, E-mail: peiqx@ihpc.a-star.edu.sg; Zhang, Yong-Wei, E-mail: zhangyw@ihpc.a-star.edu.sg [Institute of High Performance Computing, A-STAR, 1 Fusionopolis Way, Singapore 138632 (Singapore); Sha, Zhen-Dong [International Center for Applied Mechanics, Xi'an Jiaotong University, Xi'an 710049 (China); Zhang, Ying-Yan [School of Computing, Engineering and Mathematics, University of Western Sydney, Penrith, New South Wales 2751 (Australia)

    2014-01-14T23:59:59.000Z

    Silicene, a graphene-like two-dimensional silicon, has attracted great attention due to its fascinating electronic properties similar to graphene and its compatibility with existing semiconducting technology. So far, the effects of temperature and strain rate on its mechanical properties remain unexplored. We investigate the mechanical properties of silicene under uniaxial tensile deformation by using molecular dynamics simulations. We find that the fracture strength and fracture strain of silicene are much higher than those of bulk silicon, though the Young's modulus of silicene is lower than that of bulk silicon. An increase in temperature decreases the fracture strength and fracture strain of silicene significantly, while an increase in strain rate enhances them slightly. The fracture process of silicene is also studied and brittle fracture behavior is observed in the simulations.

  2. The effect of neutron irradiation on the mechanical properties of C/SiC composites

    SciTech Connect (OSTI)

    Shih, Chunghao [ORNL] [ORNL; Katoh, Yutai [ORNL] [ORNL; Snead, Lance Lewis [ORNL] [ORNL; Steinbeck, John [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    The effects of neutron irradiation to 3.5 and 9.5 dpa at 730 C on a 2D plain woven carbon fiber reinforced polymer derived SiC matrix composite are presented. For both fluences, the irradiation caused in-plane contraction and trans-plane expansion. Irradiation also caused substantial reduction in composite flexural strength (54%) and increase in flexural tangent modulus (+85%). The extents of dimensional/ mechanical property changes were greater for the higher fluence irradiated samples. Those changes suggest the instability of the polymer derived SiC matrix following irradiation. The nature of the mechanical property changes suggest increased clamping stress between the fiber and the matrix. The composite property changes are explained in terms of irradiation effects on composite constituents and are compared with carbon fiber reinforced carbon matrix composite as a reference material.

  3. Influence of oriented topological defects on the mechanical properties of carbon nanotube heterojunctions

    SciTech Connect (OSTI)

    Lee, We-Jay [National Center for High-Performance Computing; Chang, Jee-Gong [National Center for High-Performance Computing; Yang, An-Cheng [National Center for High-Performance Computing; Wang, Yeng-Tseng [National Center for High-Performance Computing; Su, Wan-Sheng [National Center for High-Performance Computing; Wang, Cai-Zhuang [Ames Laboratory; Ho, Kai-Ming [Ames Laboratory

    2013-10-10T23:59:59.000Z

    The mechanical properties of finite-length (5,0)/(8,0) single-walled carbon nanotube (SWCNT) heterojunctions with manipulated topological defects are investigated using molecular dynamics simulation calculations. The results show that the mechanical properties and deformation behavior of SWCNT heterojunctions are mainly affected not only by the diameter of the thinner segment of the SWCNT heterojunction but also by the orientation of the heptagon-heptagon (7-7) pair in the junction region. Moreover, the orientation of the 7-7 pair strongly affects those properties in the compression loading than those in tensile loading. Finally, it is found that the location of buckling deformation in the heterojunctions is dependent on the orientation of the 7-7 pair in the compression.

  4. Reasons for superior mechanical and corrosion properties of 2219 aluminum alloy electron beam welds

    SciTech Connect (OSTI)

    Koteswara Rao, S.R. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Madras, Chennai-600 036 (India)]. E-mail: sajjarkr@yahoo.com; Madhusudhan Reddy, G. [Defense Metallurgical Research Laboratory, Hyderabad-500 058 (India); Srinivasa Rao, K. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Madras, Chennai-600 036 (India); Kamaraj, M. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Madras, Chennai-600 036 (India); Prasad Rao, K. [Department of Metallurgical and Materials Engineering, Indian Institute of Technology, Madras, Chennai-600 036 (India)

    2005-11-15T23:59:59.000Z

    Electron beam welds of aluminum alloy 2219 offer much higher strength compared to gas tungsten arc welds of the same alloy and the reasons for this have not been fully explored. In this study both types of welds were made and mechanical properties were evaluated by tensile testing and pitting corrosion resistance by potentio dynamic polarization tests. It is shown that electron beam welds exhibit superior mechanical and corrosion properties. The weld metals have been characterized by scanning electron microscopy; transmission electron microscopy and electron probe micro analysis. Presence of partially disintegrated precipitates in the weld metal, finer micro porosity and uniform distribution of copper in the matrix were found to be the reasons for superior properties of electron beam welds apart from the fine equiaxed grain structure. Transmission electron micrographs of the heat affected zones revealed the precipitate disintegration and over aging in gas tungsten arc welds.

  5. ENGINEERED INTERFACE CHEMISTRY TO IMPROVE THE MECHANICAL PROPERTIES OF CARBON FIBER COMPOSITES CURED BY ELECTRON BEAM

    SciTech Connect (OSTI)

    Vautard, Frederic [ORNL; Grappe, Hippolyte A. [Oak Ridge Institute for Science and Education (ORISE); Ozcan, Soydan [ORNL

    2014-01-01T23:59:59.000Z

    A reactive sizing was designed to achieve high levels of interfacial adhesion and mechanical properties with a carbon fiber-acrylate system cured by electron beam (EB). The sizing was made of a partially cured epoxy sizing with a high density of pendant functional groups (acrylate functionality) able to generate a covalent bonding with the matrix. The interlaminar shear strength was clearly improved from 61 MPa to 81 MPa (+ 33 %) without any post-processing, reaching a similar value to the one obtained with the same system cured by a thermal treatment. Observation of the fracture profiles clearly highlighted a change in the fracture mechanism from a purely adhesive failure to a cohesive failure. Such improvements of the mechanical properties of carbon fiber composites cured by EB, without any post-cure, have not been reported previously to the best of our knowledge. This constitutes a breakthrough for the industrial development of composites EB curing.

  6. A Load-based Micro-indentation Technique for Mechanical Property and NDE Evaluation

    SciTech Connect (OSTI)

    Bruce S. Kang; Chuanyu Feng; Jared M. Tannenbaum; M.A. Alvin

    2009-06-04T23:59:59.000Z

    A load-based micro-indentation technique has been developed for evaluating mechanical properties of materials. Instead of using measured indentation depth or contact area as a necessary parameter, the new technique is based on the indentation load, coupled with a multiple-partial unloading procedure for mechanical property evaluation. The proposed load-based micro-indentation method is capable of determining Young’s modulus of metals, superalloys, and single crystal matrices, and stiffness of coated material systems with flat, tubular, or curved architectures. This micro-indentation technique can be viewed as a viable non-destructive evaluation (NDE) technique for determining as-manufactured and process-exposed metal, superalloy, single crystal, and TBC-coated material properties. Based on this technique, several bond coated substrates were tested at various stages of thermal cycles. The time-series evaluation of test material surface stiffness reveals the status of coating strength without any alternation of the coating surface, making it a true time-series NDE investigation. The microindentation test results show good correlation with post mortem microstructural analyses. This technique also shows promise for the development of a portable instrument for on-line, in-situ NDE and mechanical properties measurement of structural components.

  7. Direct Measurement of the Nanoscale Mechanical Properties of NiTi Shape Memory Gordon A. Shaw1

    E-Print Network [OSTI]

    Crone, Wendy C.

    Direct Measurement of the Nanoscale Mechanical Properties of NiTi Shape Memory Alloy Gordon A. Shaw.S.A. ABSTRACT The mechanical properties of sputter-deposited NiTi shape memory alloy thin films ranging the findings, which suggest that the substrate tends block the shape memory effect as film thickness decreases

  8. "Physio-Mechanical Properties of a New Zinc-Reinforced Glass Ionomer Restorative Material" "Sarah Al-Angari*1

    E-Print Network [OSTI]

    Zhou, Yaoqi

    "Physio-Mechanical Properties of a New Zinc-Reinforced Glass Ionomer Restorative Material" "Sarah proposed as an improved restorative material. The study compared the mechanical properties of a ZRGIC restorative material (ChemFil Rock, (Dentsply)), with three commercially available glass ionomers (GICs); Fuji

  9. Mechanical Properties of Aluminum Fluoride Glass Fibers James Colaizzi, M. John Matthewson, Tariq Iqbal, and Mahmoud R. Shahriari

    E-Print Network [OSTI]

    Matthewson, M. John

    #12;Mechanical Properties of Aluminum Fluoride Glass Fibers James Colaizzi, M. John Matthewson solutions of various pH values on the mechanical properties of polymer coated optical fibers of an aluminum to failure of the fiber. In static fatigue, the time to failure of the aluminum fluoride-based fibers

  10. Process optimization of Hexoloy SX-SiC towards improved mechanical properties

    SciTech Connect (OSTI)

    Srinivasan, G.V.; Lau, S.K.; Storm, R.S. [Carborundum Co., Niagara Falls, NY (United States); Ferber, M.K.; Jenkins, M.G. [Oak Ridge National Lab., TN (United States)

    1993-04-01T23:59:59.000Z

    Results show that SiC materials sintered with additions of Y and Al compounds can achieve the high level of mechanical properties required for use in heat engines. However, the reaction of the second phase with SiC resulting in strength limiting pools, result in increased variability in materials properties. If this variability can be controlled, the relatively low cost of raw materials and processing for Hexoloy SX manufacture would make these materials attractive for low and high temperature engine applications. 9 figs, 3 tabs, 5 refs.

  11. Process optimization of Hexoloy SX-SiC towards improved mechanical properties

    SciTech Connect (OSTI)

    Srinivasan, G.V.; Lau, S.K.; Storm, R.S. (Carborundum Co., Niagara Falls, NY (United States)); Ferber, M.K.; Jenkins, M.G. (Oak Ridge National Lab., TN (United States))

    1993-01-01T23:59:59.000Z

    Results show that SiC materials sintered with additions of Y and Al compounds can achieve the high level of mechanical properties required for use in heat engines. However, the reaction of the second phase with SiC resulting in strength limiting pools, result in increased variability in materials properties. If this variability can be controlled, the relatively low cost of raw materials and processing for Hexoloy SX manufacture would make these materials attractive for low and high temperature engine applications. 9 figs, 3 tabs, 5 refs.

  12. Two-phase chromium-niobium alloys exhibiting improved mechanical properties at high temperatures

    DOE Patents [OSTI]

    Liu, C.T.; Takeyama, Masao.

    1994-02-01T23:59:59.000Z

    The specification discloses chromium-niobium alloys which exhibit improved mechanical properties at high temperatures in the range of 1250 C and improved room temperature ductility. The alloys contain a Cr[sub 2]Nb-rich intermetallic phase and a Cr-rich phase with an overall niobium concentration in the range of from about 5 to about 18 at. %. The high temperature strength is substantially greater than that of state of the art nickel-based superalloys for enhanced high temperature service. Further improvements in the properties of the compositions are obtained by alloying with rhenium and aluminum; and additional rare-earth and other elements. 14 figures.

  13. Two-phase chromium-niobium alloys exhibiting improved mechanical properties at high temperatures

    DOE Patents [OSTI]

    Liu, Chain T. (Oak Ridge, TN); Takeyama, Masao (Tokyo, JP)

    1994-01-01T23:59:59.000Z

    The specification discloses chromium-niobium alloys which exhibit improved mechanical properties at high temperatures in the range of 1250.degree. C. and improved room temperature ductility. The alloys contain a Cr.sub.2 Nb-rich intermetallic phase and a Cr-rich phase with an overall niobium concentration in the range of from about 5 to about 18 at. %. The high temperature strength is substantially greater than that of state of the art nickel-based superalloys for enhanced high temperature service. Further improvements in the properties of the compositions are obtained by alloying with rhenium and aluminum; and additional rare-earth and other elements.

  14. Topography and Mechanical Property Mapping of International Simple Glass Surfaces with Atomic Force Microscopy

    SciTech Connect (OSTI)

    Hopf, Juliane [ORNL; Pierce, Eric M [ORNL

    2014-01-01T23:59:59.000Z

    Quantitative Nanomechanical Peak Force (PF-QNM) TappingModeTM atomic force microscopy measurements are presented for the first time on polished glass surfaces. The PF-QNM technique allows for topography and mechanical property information to be measured simultaneously at each pixel. Results for the international simple glass which represents a simplified version of SON68 glass suggests an average Young s modulus of 78.8 15.1 GPa is within the experimental error of the modulus measured for SON68 glass (83.6 2 GPa) with conventional approaches. Application of the PF-QNM technique will be extended to in situ glass corrosion experiments with the goal of gaining atomic-scale insights into altered layer development by exploiting the mechanical property differences that exist between silica gel (e.g., altered layer) and pristine glass surface.

  15. Composition, morphology and mechanical properties of sputtered TiAlN coating

    SciTech Connect (OSTI)

    Budi, Esmar, E-mail: esmarbudi@unj.ac.id [Department of Physics, Faculty of Science and Mathematics, Universitas Negeri Jakarta, Jl. Pemuda No. 10, Jakarta 13220 (Indonesia); Razali, M. Mohd. [Faculty of Manufacturing Engineering, Universiti Teknikal Malaysia Melaka, Karung Berkunci No. 1752 Pejabat Pos Durian Tunggal 76109 Melaka (Malaysia); Nizam, A. R. Md. [Faculty of Manufacturing Engineering, UniversitiTeknikal Malaysia Melaka, Karung Berkunci No. 1752 Pejabat Pos Durian Tunggal 76109 Melaka (Malaysia)

    2014-03-24T23:59:59.000Z

    TiAlN coating was deposited on the tungsten carbide cutting tool by using DC magnetron sputtering system to study the influence of substrate bias and nitrogen flow rate on the composition, morphology and mechanical properties. The negatively substrate bias and nitrogen flow rate was varied from about ?79 to ?221 V and 30 sccm to 72 sccm, respectively. The coating composition and roughness were characterized by using SEM/EDX and Atomic Force Microscopy (AFM), respectively. The dynamic ultra micro hardness tester was used to measure the mechanical properties. The coating hardness increases to about 10-12 GPa with an increase of the negatively substrate bias up to ? 200 V and it tend to decrease with an increase in nitrogen flow rate up to 70 sccm. The increase of hardness follows the increase of Ti and N content and rms coating roughness.

  16. Method and apparatus for determination of mechanical properties of functionally-graded materials

    DOE Patents [OSTI]

    Giannakopoulos, Antonios E. (Somerville, MA); Suresh, Subra (Wellesley, MA)

    1999-01-01T23:59:59.000Z

    Techniques for the determination of mechanical properties of homogenous or functionally-graded materials from indentation testing are presented. The technique is applicable to indentation on the nano-scale through the macro-scale including the geological scale. The technique involves creating a predictive load/depth relationship for a sample, providing an experimental load/depth relationship, comparing the experimental data to the predictive data, and determining a physical characteristic from the comparison.

  17. A non-destructive method for measuring the mechanical properties of ultrathin films prepared by atomic layer deposition

    SciTech Connect (OSTI)

    Zhang, Qinglin [General Motors Global Research and Development Center, Warren, Michigan 48090 (United States); Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506-0046 (United States); Xiao, Xingcheng, E-mail: xingcheng.xiao@gm.com; Verbrugge, Mark W. [General Motors Global Research and Development Center, Warren, Michigan 48090 (United States); Cheng, Yang-Tse [Department of Chemical and Materials Engineering, University of Kentucky, Lexington, Kentucky 40506-0046 (United States)

    2014-08-11T23:59:59.000Z

    The mechanical properties of ultrathin films synthesized by atomic layer deposition (ALD) are critical for the liability of their coated devices. However, it has been a challenge to reliably measure critical properties of ALD films due to the influence from the substrate. In this work, we use the laser acoustic wave (LAW) technique, a non-destructive method, to measure the elastic properties of ultrathin Al{sub 2}O{sub 3} films by ALD. The measured properties are consistent with previous work using other approaches. The LAW method can be easily applied to measure the mechanical properties of various ALD thin films for multiple applications.

  18. Mechanism-based Representative Volume Elements (RVEs) for Predicting Property Degradations in Multiphase Materials

    SciTech Connect (OSTI)

    Xu, Wei; Sun, Xin; Li, Dongsheng; Ryu, Seun; Khaleel, Mohammad A.

    2013-02-01T23:59:59.000Z

    Quantitative understanding of the evolving thermal-mechanical properties of a multi-phase material hinges upon the availability of quantitative statistically representative microstructure descriptions. Questions then arise as to whether a two-dimensional (2D) or a three-dimensional (3D) representative volume element (RVE) should be considered as the statistically representative microstructure. Although 3D models are more representative than 2D models in general, they are usually computationally expensive and difficult to be reconstructed. In this paper, we evaluate the accuracy of a 2D RVE in predicting the property degradations induced by different degradation mechanisms with the multiphase solid oxide fuel cell (SOFC) anode material as an example. Both 2D and 3D microstructure RVEs of the anodes are adopted to quantify the effects of two different degradation mechanisms: humidity-induced electrochemical degradation and phosphorus poisoning induced structural degradation. The predictions of the 2D model are then compared with the available experimental measurements and the results from the 3D model. It is found that the 2D model, limited by its inability of reproducing the realistic electrical percolation, is unable to accurately predict the degradation of thermo-electrical properties. On the other hand, for the phosphorus poisoning induced structural degradation, both 2D and 3D microstructures yield similar results, indicating that the 2D model is capable of providing computationally efficient yet accurate results for studying the structural degradation within the anodes.

  19. Irradiation imposed degradation of the mechanical and electrical properties of electrical insulation for future accelerator magnets

    SciTech Connect (OSTI)

    Polinski, J.; Chorowski, M.; Bogdan, P.; Strychalski, M. [Wroclaw University of Technology, Wyb. Wyspianskiego 27, 50-370 Wroclaw (Poland); Rijk, G. de [European Organization for Nuclear Research CERN, 1211 Geneva (Switzerland)

    2014-01-27T23:59:59.000Z

    Future accelerators will make extensive use of superconductors made of Nb{sub 3}Sn, which allows higher magnetic fields than NbTi. However, the wind-and-react technology of Nb{sub 3}Sn superconducting magnet production makes polyimide Kapton® non applicable for the coils' electrical insulation. A Nb{sub 3}Sn technology compatible insulation material should be characterized by high radiation resistivity, good thermal conductivity, and excellent mechanical properties. Candidate materials for the electrical insulation of future accelerator's magnet coils have to be radiation certified with respect to potential degradation of their electrical, thermal, and mechanical properties. This contribution presents procedures and results of tests of the electrical and mechanical properties of DGEBA epoxy + D400 hardener, which is one of the candidates for the electrical insulation of future magnets. Two test sample types have been used to determine the material degradation due to irradiation: a untreated one (unirradiated) and irradiated at 77 K with 11 kGy/min intense, 4MeV energy electrons beam to a total dose of 50 MGy.

  20. Development of small punch testing technique and its application to evaluation of mechanical properties degradation

    SciTech Connect (OSTI)

    Kameda, J.

    1993-10-01T23:59:59.000Z

    The present paper summarizes a small punch (SP) testing technique developed and its application to mechanical properties characterization. It has been clearly shown on ferritic alloys that the SP test was evaluate the intergranular embrittling potency of segregated solute, such as P, Sn and Sb causing temper embrittlement, and the effects of neutron irradiation and post-irradiation annealing, giving rise to changes in the hardness and intergranular solute segregation, on the fracture properties in terms of the ductile-brittle transition temperature (DBTT). A linear relation of the DBTT determined by the SP test to that by Charpy V-notched tests has been theoretically and experimentally established. In Al alloy substrates coated with amorphous and overlaying ceramics, moreover, the global and local fracture properties were well characterized by the SP test together with acoustic emission techniques.

  1. Thermodynamic and mechanical properties of TiC from ab initio calculation

    SciTech Connect (OSTI)

    Dang, D. Y.; Fan, J. L.; Gong, H. R., E-mail: gonghr@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China)

    2014-07-21T23:59:59.000Z

    The temperature-dependent thermodynamic and mechanical properties of TiC are systematically investigated by means of a combination of density-functional theory, quasi-harmonic approximation, and thermal electronic excitation. It is found that the quasi-harmonic Debye model should be pertinent to reflect thermodynamic properties of TiC, and the elastic properties of TiC decease almost linearly with the increase of temperature. Calculations also reveal that TiC possesses a pronounced directional pseudogap across the Fermi level, mainly due to the strong hybridization of Ti 3d and C 2p states. Moreover, the strong covalent bonding of TiC would be enhanced (reduced) with the decrease (increase) of temperature, while the change of volume (temperature) should have negligible effect on density of states at the Fermi level. The calculated results agree well with experimental observations in the literature.

  2. A few nascent methods for measuring mechanical properties of the biological cell.

    SciTech Connect (OSTI)

    Thayer, Gayle Echo; de Boer, Maarten Pieter; Corvalan, Carlos (Purdue University, West Lafayette, IN); Corwin, Alex David; Campanella, Osvaldo H. (Purdue University, West Lafayette, IN); Nivens, David (Purdue University, West Lafayette, IN); Werely, Steven (Purdue University, West Lafayette, IN); Sumali, Anton Hartono; Koch, Steven John

    2006-01-01T23:59:59.000Z

    This report summarizes a survey of several new methods for obtaining mechanical and rheological properties of single biological cells, in particular: (1) The use of laser Doppler vibrometry (LDV) to measure the natural vibrations of certain cells. (2) The development of a novel micro-electro-mechanical system (MEMS) for obtaining high-resolution force-displacement curves. (3) The use of the atomic force microscope (AFM) for cell imaging. (4) The adaptation of a novel squeezing-flow technique to micro-scale measurement. The LDV technique was used to investigate the recent finding reported by others that the membranes of certain biological cells vibrate naturally, and that the vibration can be detected clearly with recent instrumentation. The LDV has been reported to detect motions of certain biological cells indirectly through the motion of a probe. In this project, trials on Saccharomyces cerevisiae tested and rejected the hypothesis that the LDV could measure vibrations of the cell membranes directly. The MEMS investigated in the second technique is a polysilicon surface-micromachined force sensor that is able to measure forces to a few pN in both air and water. The simple device consists of compliant springs with force constants as low as 0.3 milliN/m and Moire patterns for nanometer-scale optical displacement measurement. Fields from an electromagnet created forces on magnetic micro beads glued to the force sensors. These forces were measured and agreed well with finite element prediction. It was demonstrated that the force sensor was fully functional when immersed in aqueous buffer. These results show the force sensors can be useful for calibrating magnetic forces on magnetic beads and also for direct measurement of biophysical forces on-chip. The use of atomic force microscopy (AFM) for profiling the geometry of red blood cells was the third technique investigated here. An important finding was that the method commonly used for attaching the cells to a substrate actually modified the mechanical properties of the cell membrane. Thus, the use of the method for measuring the mechanical properties of the cell may not be completely appropriate without significant modifications. The latest of the studies discussed in this report is intended to overcome the drawback of the AFM as a means of measuring mechanical and rheological properties. The squeezing-flow AFM technique utilizes two parallel plates, one stationary and the other attached to an AFM probe. Instead of using static force-displacement curves, the technique takes advantage of frequency response functions from force to velocity. The technique appears to be quite promising for obtaining dynamic properties. More research is required to develop this technique.

  3. MICROSTRUCTURE AND MECHANICAL PROPERTY PERFORMANCE OF COMMERCIAL GRADE API PIPELINE STEELS IN HIGH PRESSURE GASEOUS HYDROGEN

    SciTech Connect (OSTI)

    Stalheim, Mr. Douglas [DGS Metallurgical Solutions Inc; Boggess, Todd [Secat; San Marchi, Chris [Sandia National Laboratories (SNL); Jansto, Steven [Reference Metals Company; Somerday, Dr. B [Sandia National Laboratories (SNL); Muralidharan, Govindarajan [ORNL; Sofronis, Prof. Petros [University of Illinois

    2010-01-01T23:59:59.000Z

    The continued growth of the world s developing countries has placed an ever increasing demand on traditional fossil fuel energy sources. This development has lead to increasing research and development of alternative energy sources. Hydrogen gas is one of the potential alternative energy sources under development. Currently the most economical method of transporting large quantities of hydrogen gas is through steel pipelines. It is well known that hydrogen embrittlement has the potential to degrade steel s mechanical properties when hydrogen migrates into the steel matrix. Consequently, the current pipeline infrastructure used in hydrogen transport is typically operated in a conservative fashion. This operational practice is not conducive to economical movement of significant volumes of hydrogen gas as an alternative to fossil fuels. The degradation of the mechanical properties of steels in hydrogen service is known to depend on the microstructure of the steel. Understanding the levels of mechanical property degradation of a given microstructure when exposed to hydrogen gas under pressure can be used to evaluate the suitability of the existing pipeline infrastructure for hydrogen service and guide alloy and microstructure design for new hydrogen pipeline infrastructure. To this end, the 2 Copyright 2010 by ASME microstructures of relevant steels and their mechanical properties in relevant gaseous hydrogen environments must be fully characterized to establish suitability for transporting hydrogen. A project to evaluate four commercially available pipeline steels alloy/microstructure performance in the presences of gaseous hydrogen has been funded by the US Department of Energy along with the private sector. The microstructures of four pipeline steels were characterized and then tensile testing was conducted in gaseous hydrogen and helium at pressures of 800, 1600 and 3000 psi. Based on measurements of reduction of area, two of the four steels that performed the best across the pressure range were selected for evaluation of fracture and fatigue performance in gaseous hydrogen at 800 and 3000 psi. This paper will describe the work performed on four commercially available pipeline steels in the presence of gaseous hydrogen at pressures relevant for transport in pipelines. Microstructures and mechanical property performances will be compared. In addition, recommendations for future work related to gaining a better understanding of steel pipeline performance in hydrogen service will be discussed.

  4. Temperature-dependent mechanical property testing of nitrate thermal storage salts.

    SciTech Connect (OSTI)

    Everett, Randy L.; Iverson, Brian D.; Broome, Scott Thomas; Siegel, Nathan Phillip; Bronowski, David R.

    2010-09-01T23:59:59.000Z

    Three salt compositions for potential use in trough-based solar collectors were tested to determine their mechanical properties as a function of temperature. The mechanical properties determined were unconfined compressive strength, Young's modulus, Poisson's ratio, and indirect tensile strength. Seventeen uniaxial compression and indirect tension tests were completed. It was found that as test temperature increases, unconfined compressive strength and Young's modulus decreased for all salt types. Empirical relationships were developed quantifying the aforementioned behaviors. Poisson's ratio tends to increase with increasing temperature except for one salt type where there is no obvious trend. The variability in measured indirect tensile strength is large, but not atypical for this index test. The average tensile strength for all salt types tested is substantially higher than the upper range of tensile strengths for naturally occurring rock salts. Interest in raising the operating temperature of concentrating solar technologies and the incorporation of thermal storage has motivated studies on the implementation of molten salt as the system working fluid. Recently, salt has been considered for use in trough-based solar collectors and has been shown to offer a reduction in levelized cost of energy as well as increasing availability (Kearney et al., 2003). Concerns regarding the use of molten salt are often related to issues with salt solidification and recovery from freeze events. Differences among salts used for convective heat transfer and storage are typically designated by a comparison of thermal properties. However, the potential for a freeze event necessitates an understanding of salt mechanical properties in order to characterize and mitigate possible detrimental effects. This includes stress imparted by the expanding salt. Samples of solar salt, HITEC salt (Coastal Chemical Co.), and a low melting point quaternary salt were cast for characterization tests to determine unconfined compressive strength, indirect tensile strength, coefficient of thermal expansion (CTE), Young's modulus, and Poisson's ratio. Experiments were conducted at multiple temperatures below the melting point to determine temperature dependence.

  5. Composition and grain size effects on the structural and mechanical properties of CuZr nanoglasses

    SciTech Connect (OSTI)

    Adibi, Sara [Institute of High Performance Computing, A*STAR, 138632 Singapore (Singapore); Mechanical Engineering Department, National University of Singapore, 117576 Singapore (Singapore); Branicio, Paulo S., E-mail: branicio@ihpc.a-star.edu.sg; Zhang, Yong-Wei [Institute of High Performance Computing, A*STAR, 138632 Singapore (Singapore); Joshi, Shailendra P., E-mail: Shailendra@nus.edu.sg [Mechanical Engineering Department, National University of Singapore, 117576 Singapore (Singapore)

    2014-07-28T23:59:59.000Z

    Nanoglasses (NGs), metallic glasses (MGs) with a nanoscale grain structure, have the potential to considerably increase the ductility of traditional MGs while retaining their outstanding mechanical properties. We investigated the effects of composition on the structural and mechanical properties of CuZr NG films with grain sizes between 3 to 15?nm using molecular dynamics simulations. Results indicate a transition from localized shear banding to homogeneous superplastic flow with decreasing grain size, although the critical average grain size depends on composition: 5?nm for Cu{sub 36}Zr{sub 64} and 3?nm for Cu{sub 64}Zr{sub 36}. The flow stress of the superplastic NG at different compositions follows the trend of the yield stress of the parent MG, i.e., Cu{sub 36}Zr{sub 64} yield/flow stress: 2.54?GPa/1.29?GPa and Cu{sub 64}Zr{sub 36} yield/flow stress: 3.57?GPa /1.58?GPa. Structural analysis indicates that the differences in mechanical behavior as a function of composition are rooted at the distinct statistics of prominent atomic Voronoi polyhedra. The mechanical behavior of NGs is also affected by the grain boundary thickness and the fraction of atoms at interfaces for a given average grain size. The results suggest that the composition dependence of the mechanical behavior of NGs follows that of their parent MGs, e.g., a stronger MG will generate a stronger NG, while the intrinsic tendency for homogeneous deformation occurring at small grain size is not affected by composition.

  6. Structural, thermodynamic, mechanical, and magnetic properties of FeW system

    SciTech Connect (OSTI)

    Ren, Q. Q.; Fan, J. L.; Han, Y.; Gong, H. R., E-mail: gonghr@csu.edu.cn [State Key Laboratory of Powder Metallurgy, Central South University, Changsha, Hunan 410083 (China)

    2014-09-07T23:59:59.000Z

    The Fe-W system is systematically investigated through a combined use of first-principles calculation, cluster expansion, special quasirandom structures, and experiments. It is revealed that the ferromagnetic state of BCC Fe-W solid solution has lower heat of formation than its nonmagnetic state within the entire composition range, and intermetallic ?-Fe{sub 2}W and ?-Fe{sub 7}W{sub 6} phases are energetically favorable with negative heats of formation. Calculations also show that the Fe-W solid solution has much lower coefficient of thermal expansion than its mechanical mixture, and that the descending sequence of temperature-dependent elastic moduli of each Fe-W solid solution is E?>?G?>?B. Moreover, magnetic state should have an important effect on mechanical properties of Fe-W phases, and electronic structures can provide a deeper understanding of various properties of Fe-W. The derived results agree well with experimental observations, and can clarify two experimental controversies regarding structural stability and magnetic property of Fe-W phases in the literature.

  7. Reactor Materials Program - Baseline Material Property Handbook - Mechanical Properties of 1950's Vintage Stainless Steel Weldment Components, Task Number 89-23-A-1

    SciTech Connect (OSTI)

    Stoner, K.J.

    1999-11-05T23:59:59.000Z

    The Process Water System (primary coolant) piping of the nuclear production reactors constructed in the 1950''s at Savannah River Site is comprised primarily of Type 304 stainless steel with Type 308 stainless steel weld filler. A program to measure the mechanical properties of archival PWS piping and weld materials (having approximately six years of service at temperatures between 25 and 100 degrees C) has been completed. The results from the mechanical testing has been synthesized to provide a mechanical properties database for structural analyses of the SRS piping.

  8. Chemical and mechanical performance properties for various final waste forms -- PSPI scoping study

    SciTech Connect (OSTI)

    Farnsworth, R.K.; Larsen, E.D.; Sears, J.W.; Eddy, T.L.; Anderson, G.L.

    1996-09-01T23:59:59.000Z

    The US DOE is obtaining data on the performance properties of the various final waste forms that may be chosen as primary treatment products for the alpha-contaminated low-level and transuranic waste at the INEL`s Transuranic Storage Area. This report collects and compares selected properties that are key indicators of mechanical and chemical durability for Portland cement concrete, concrete formed under elevated temperature and pressure, sulfur polymer cement, borosilicate glass, and various forms of alumino-silicate glass, including in situ vitrification glass and various compositions of iron-enriched basalt (IEB) and iron-enriched basalt IV (IEB4). Compressive strength and impact resistance properties were used as performance indicators in comparative evaluation of the mechanical durability of each waste form, while various leachability data were used in comparative evaluation of each waste form`s chemical durability. The vitrified waste forms were generally more durable than the non-vitrified waste forms, with the iron-enriched alumino-silicate glasses and glass/ceramics exhibiting the most favorable chemical and mechanical durabilities. It appears that the addition of zirconia and titania to IEB (forming IEB4) increases the leach resistance of the lanthanides. The large compositional ranges for IEB and IEB4 more easily accommodate the compositions of the waste stored at the INEL than does the composition of borosilicate glass. It appears, however, that the large potential variation in IEB and IEB4 compositions resulting from differing waste feed compositions can impact waste form durability. Further work is needed to determine the range of waste stream feed compositions and rates of waste form cooling that will result in acceptable and optimized IEB or IEB4 waste form performance. 43 refs.

  9. Improved mechanical and electrical properties in electrospun polyimide/multiwalled carbon nanotubes nanofibrous composites

    SciTech Connect (OSTI)

    Zha, Jun-Wei; Sun, Fang; Wang, Si-Jiao; Wang, Dongrui; Lin, Xiang; Dang, Zhi-Min, E-mail: dangzm@ustb.edu.cn [Laboratory of Dielectric Polymer Materials and Devices, Department of Polymer Science and Engineering, School of Chemistry and Biological Engineering, University of Science and Technology Beijing, Beijing 100083 (China); Chen, George [School of Electronics and Computer Science, University of Southampton, Southampton SO17 1BJ (United Kingdom)

    2014-10-07T23:59:59.000Z

    Highly aligned polyimide (PI) and PI/multi-walled carbon nanotubes (PI/MWCNTs) nanofibrous composites by incorporating poly(ethylene oxide) as the dispersing medium were fabricated using electrospinning technique. The morphology, mechanical, and electrical properties of the electrospun nanofibrous composites were investigated. Scanning electron microscope showed that the functionalized MWCNTs (f-MWCNTs) were well dispersed and oriented along the nanofiber axis. Analysis of electrical properties indicated a remarkable improvement on the alternating current conductivity by introduction of the aligned f-MWCNTs. Besides, with addition of 3?vol.?% f-MWCNTs, the obvious enhancement of tensile modulus and strength was achieved. Thus, the electrospun PI/MWCNTs nanofibrous composites have great potential applications in multifunctional engineering materials.

  10. A Load-Based Multiple-Partial Unloading Micro-Indentation Technique for Mechanical Property Evaluation

    SciTech Connect (OSTI)

    C. Feng; J.M. Tannenbaum; B.S. Kang; M.A. Alvin

    2009-07-23T23:59:59.000Z

    A load-based multiple-partial unloading microindentation technique has been developed for evaluating mechanical properties of materials. Comparing to the current prevailing nano/micro-indentation methods, which require precise measurements of the indentation depth and load, the proposed technique only measures indentation load and the overall indentation displacement (i.e. including displacement of the loading apparatus). Coupled with a multiple-partial unloading procedure during the indentation process, this technique results in a load-depth sensing indentation system capable of determining Young’s modulus of metallic alloys with flat, tubular, or curved architectures. Test results show consistent and correct elastic modulus values when performing indentation tests on standard alloys such as steel, aluminum, bronze, and single crystal superalloys. The proposed micro-indentation technique has led to the development of a portable loaddepth sensing indentation system capable of on-site, in-situ material property measurement.

  11. Determination of mechanical properties of Ni-Cr-P amorphous alloys

    E-Print Network [OSTI]

    Kondlapudi, Swaroop Kumar R

    1991-01-01T23:59:59.000Z

    . Kondlapudi, B. E. , Qsmania University Co-Chairs of Advisory Committee : Dr. A. wolfenden Dr. R. Griffin A study of the mechanical properties of Ni80 xCrxPgp amorphous alloys (x = 0 to 40 at% in steps of 5. 0) has been undertaken at Texas A&M University... with increase in Chromium content. Microhardness measurements have been made both for the wheel and free sides of the as-cast ribbons. Dynamic Young's modulus measurements were performed using the PUCQT (Piezoelectric Ultrasonic Composite Oscillator...

  12. Mechanical properties and morphology of crystalline polymers and their continuous fiber composites

    SciTech Connect (OSTI)

    Jang, B.; Liu, C.W.; Wang, C.Z.; Shih, W.K.

    1988-07-01T23:59:59.000Z

    Neat-resin and continuous fiber-reinforced versions of the crystalline thermoplastic polypropylene (PP) and its rubber-toughened form are compared with respect to morphology, microstructure, and mechanical properties. The rubber phase's addition to the PP matrix resin results in a uniform dispersion of rubber particles whose sizes increase with increasing rubber weight fraction. The maximum load tolerated by the laminates prior to delamination appears to be controlled by the resin yield strength and the fiber-matrix interfacial adhesion. A much lower degree of stress whitening is noted in the reinforced rubber-modified PP than its unreinforced counterparts. 60 references.

  13. The sensitivity of rock mechanical properties to the method by which the clay volume is determined

    E-Print Network [OSTI]

    Ivey, Henry Alexander

    1986-01-01T23:59:59.000Z

    were studied. At At ~ Rv s o form with Rv by the Voigt average technique'' form n Rv ( V xRv xW form i 1 i i i ~ . (7) or with Rv by the Reuse average technique'' form n 1/Rvf $ V xWi Rvi form . . (8) Shear Wave Travel Time Model Determination...'or the degree of MASTER OF SCIENCE AUGUST 1986 Major Subject: petroleum Engineering THE SENSITIVITY OF ROCK MECHANICAL PROPERTIES TO THE METHOD BY WHICH THE CLAY VOLUME IS DETERMINED A Thesis by HENRY ALEXANDER IVEY Approved as to style and content by...

  14. Aspect Ratio Effect of Functionalized/Non-Functionalized Multiwalled Carbon Nanotubes on the Mechanical Properties of Cementitious Materials

    E-Print Network [OSTI]

    Ashour, Ahmad

    2012-10-19T23:59:59.000Z

    compared to other composite materials, a limited amount of research has been conducted on the CNTs/cement composites. In order to investigate how the aspect ratio of functionalized/non-functionalized MWCNTs affects the mechanical properties...

  15. Status of Initial Assessment of Physical and Mechanical Properties of Graphite Grades for NGNP Appkications

    SciTech Connect (OSTI)

    Strizak, Joe P [ORNL; Burchell, Timothy D [ORNL; Windes, Will [Idaho National Laboratory (INL)

    2011-12-01T23:59:59.000Z

    Current candidate graphite grades for the core structures of NGNP include grades NBG-17, NBG-18, PCEA and IG-430. Both NBG-17 and NBG-18 are manufactured using pitch coke, and are vibrationally molded. These medium grain products are produced by SGL Carbon SAS (France). Tayo Tanso (Japan) produces IG-430 which is a petroleum coke, isostatically molded, nuclear grade graphite. And PCEA is a medium grain, extruded graphite produced by UCAR Carbon Co. (USA) from petroleum coke. An experimental program has been initiated to develop physical and mechanical properties data for these current candidate graphites. The results will be judged against the requirements for nuclear grade graphites set forth in ASTM standard D 7219-05 "Standard Specification for Isotropic and Near-isotropic Nuclear Graphites". Physical properties data including thermal conductivity and coefficient of thermal expansion, and mechanical properties data including tensile, compressive and flexural strengths will be obtained using the established test methods covered in D-7219 and ASTM C 781-02 "Standard Practice for Testing Graphite and Boronated Graphite Components for High-Temperature Gas-Cooled Nuclear Reactors". Various factors known to effect the properties of graphites will be investigated. These include specimen size, spatial location within a graphite billet, specimen orientation (ag and wg) within a billet, and billet-to-billet variations. The current status of the materials characterization program is reported herein. To date billets of the four graphite grades have been procured, and detailed cut up plans for obtaining the various specimens have been prepared. Particular attention has been given to the traceability of each specimen to its spatial location and orientation within a billet.

  16. The effects of unconfined slow uniform heating on the mechanical and transport properties of the westerly and charcoal granites 

    E-Print Network [OSTI]

    Bauer, Stephen Joseph

    1980-01-01T23:59:59.000Z

    THE EFFECTS OF UNCONFINED SLOW UNIFORM HEATING ON THE MECHANICAL AND TRANSPORT PROPERTIES OF THE WESTERLY AND CHARCOAL GRANITES A Thesis L by STEPHEN '-JOSEPH BAUER Submitted to the Graduate College of Texas A&M University in partial... JOSEPH BAUER Approved as to style and content by: (Chairs of Committee) iember) (Member) (Hea f Department) May 1980 111 ABSTRACT The Effects of Unconfined Slow Uniform Heating on the Mechanical and Transport Properties of the Westerly...

  17. The mechanical properties of biological structures and their materials are among the most fundamental of the numerous

    E-Print Network [OSTI]

    Denny, Mark

    The mechanical properties of biological structures and their materials are among the most hydrodynamic forces, which might be expected to place strong constraints on material properties and morphology be the case for a falling rock climber jerked to a halt by a safety rope, where the climber's kinetic energy

  18. Role of different compatibilizing approaches on the microstructure and mechanical properties of polypropylene/talc composites

    SciTech Connect (OSTI)

    Homayounfar, S. Z., E-mail: z.homayounfar@gmail.com, E-mail: rezabagh@sharif.ir; Bagheri, R., E-mail: z.homayounfar@gmail.com, E-mail: rezabagh@sharif.ir [Department of Materials Science and Engineering, Sharif University of Technology, Tehran (Iran, Islamic Republic of)

    2014-05-15T23:59:59.000Z

    Since in a highly filled polymer, a major problem arises from non-uniformity of properties due to the poor dispersion of filler, the application of coupling agents have been directed to overcome this problem and also to enhance the mechanical performance of the composites by improving the adhesion at the interface. In this study, a comparison between two major coupling approaches is conducted: 1) Using PPgMA as a kind of compatibilizer which changes the nature of the matrix, 2) Using titanate coupling agent which takes action at the interface and reacts with hydroxyl groups at the inorganic filler surface, resulting in the formation of monomolecular layer on the inorganic surface to increase compatibility of filler/matrix interface. The comparison is made based on the mechanical properties of the composites by means of elastic modulus, yield stress, impact strength and percentage of strain-to-fracture and evaluation of their effects on both the dispersion and adhesion of talc plates in the matrix through the microscopy. Transmission optical microscopy (TOM) and scanning electron microscopy (SEM) are used to observe the deformation micromechanism and the fracture surface of the composites, respectively.

  19. Effect of multiple repairs in girth welds of pipelines on the mechanical properties

    SciTech Connect (OSTI)

    Vega, O.E.; Hallen, J.M. [Departamento de Ingenieria Metalurgica, ESIQIE-IPN, Laboratorios Pesados de Metalurgia, UPALM, Zacatenco, C.P. 07738, Mexico D.F. (Mexico); Villagomez, A. [Construcciones Maritimas Mexicanas, CMM-PROTEXA, Av. Periferica s/n, Fracc. Lomas de Holche, C.P. 24120, Cd. del Carmen, Campeche (Mexico); Contreras, A. [Instituto Mexicano del Petroleo, Investigacion en Ductos, Corrosion y Materiales, Eje Central Lazaro Cardenas Norte 152 Col. San Bartolo Atepehuacan, C.P. 07730, Mexico D.F. (Mexico)], E-mail: acontrer@imp.mx

    2008-10-15T23:59:59.000Z

    This work presents the results of multiple weld repairs in the same area in seamless API X-52 microalloyed steel pipe. Four conditions of shielded metal arc welding repairs and one as-welded specimen of the girth weld were characterized to determine changes in the microstructure, grain size in the heat affected zone, and to evaluate their effect on the mechanical properties of the weld joints. The mechanical properties by means of tension tests, Charpy-V impact resistance and Vickers hardness of the welds were analyzed. The results indicate that significant changes are not generated in the microstructural constituents of the heat affected zone. Grain growth in the heat affected zone at the specimen mid-thickness with the number of repairs was observed. Tensile strength of the weld joints meets the requirement of the API 1104 standard even after the fourth weld repair. Significant reduction in Charpy-V impact resistance with the number of weld repairs was found when the notch location was in the intersection of the fusion line with the specimen mid-thickness. A significant increase in the Vickers hardness of the heat affected zone occurred after the first repair and a gradual decrease in the Vickers hardness occurred as the number of repairs increases.

  20. Statistical analysis of the mechanical properties of thin walled ductile iron castings

    SciTech Connect (OSTI)

    Schrems, Karol K.; Hawk, Jeffrey A.; Dogan, Omer N.; Druschitz, A.P. (Intermet)

    2003-01-01T23:59:59.000Z

    Ductile iron castings have long been used in the automotive market. Ductile iron is inexpensive to produce and has desirable fracture resistance and mechanical properties. However, the weight of ductile iron is driving an effort to reduce wall thickness in order to increase fuel economy. Traditionally, cast iron has been cast into thick, bulky shapes. Reducing the section size of cast iron can be done, but pushes foundry practice into new areas. A consortium of foundries, foundry suppliers, and automotive manufacturers has been pursuing the use of thin walled ductile cast iron. This paper investigates the mechanical behavior of three experimental heats of thin-wall castings in order to evaluate property trends and limits. Castings as thin as 1.7 mm (0.07 in) have been successfully cast. The study was designed to investigate the effects of thickness and different casting heats on the dependent variables of ultimate tensile strength, yield strength, elongation-to-failure, reduction in area, and hardness. The ultimate tensile strength of the castings is found to increase as the casting thickness decreases. Conversely, the elongation-to-failure is found to decrease as the casting thickness decreases. Heat-to-heat differences were found, but they were usually within the scatter of the data.

  1. A Novel Method for the Evaluation of Mechanical Properties of Cancellous Bone in the Rat Distal Femur 

    E-Print Network [OSTI]

    Lucas, Matthew W.

    2010-01-14T23:59:59.000Z

    .................................................................................................................. 35 3.7.1 Analysis of Mechanical Testing Data .............................................................. 35 3.7.2 Material Properties ........................................................................................... 37 3.7.3 Core....2 Osteoporosis and the Ovariectomized Rat Model .................................................... 5 2.3 Mechanical Testing of Cancellous Bone in Rats ..................................................... 5 2.3.1 Femoral Neck Testing...

  2. ACOUSTICAL IMAGING AND MECHANICAL PROPERTIES OF SOFT ROCK AND MARINE SEDIMENTS

    SciTech Connect (OSTI)

    Thurman E. Scott, Jr., Ph.D.; Younane Abousleiman, Ph.D.; Musharraf Zaman, Ph.D., P.E.

    2001-07-01T23:59:59.000Z

    Mechanically weak formations, such as chalks, high porosity sandstones, and marine sediments, pose significant problems for oil and gas operators. Problems such as compaction, subsidence, and loss of permeability can affect reservoir production operations. For example, the unexpected subsidence of the Ekofisk chalk in the North Sea required over one billion dollars to re-engineer production facilities to account for losses created during that compaction (Sulak 1991). Another problem in weak formations is that of shallow water flows (SWF). Deep water drilling operations sometimes encounter cases where the marine sediments, at shallow depths just below the seafloor, begin to uncontrollably flow up and around the drill pipe. SWF problems created a loss of $150 million for the Ursa development project in the U.S. Gulf Coast SWF (Furlow 1998a,b; 1999a,b). The goal of this project is to provide a database on both the rock mechanical properties and the geophysical properties of weak rocks and sediments. These could be used by oil and gas companies to detect, evaluate, and alleviate potential production and drilling problems. The results will be useful in, for example, pre-drill detection of events such as SWF's by allowing a correlation of seismic data (such as hazard surveys) to rock mechanical properties. The data sets could also be useful for 4-D monitoring of the compaction and subsidence of an existing reservoir and imaging the zones of damage. During the second quarter of the project the research team has: (1) completed acoustic sensor construction, (2) conducted reconnaissance tests to map the deformational behaviors of the various rocks, (3) developed a sample assembly for the measurement of dynamic elastic and poroelastic parameters during triaxial testing, and (4) conducted a detailed review of the scientific literature and compiled a bibliography of that review. During the first quarter of the project the research team acquired several rock types for testing including: (a) Danian chalk, (b) Cordoba Cream limestone, (c) Indiana limestone, (d) Ekofisk chalk, (e) Oil Creek sandstone, (f) unconsolidated Oil Creek sand, and (g) unconsolidated Brazos river sand. During the second quarter experiments were begun on these rock types. A series of reconnaissance experiments have been carried out on all but the Ekofisk (for which there is a preliminary data set already inhouse). A series of triaxial tests have been conducted on the Danian chalk, the Cordoba Cream limestone, the Indiana limestone, and sand samples to make a preliminary determination of the deformational mechanisms present in these samples.

  3. Estradiol influences the mechanical properties of human fetal osteoblasts through cytoskeletal changes

    SciTech Connect (OSTI)

    Muthukumaran, Padmalosini [Department of Bioengineering, National University of Singapore (Singapore)] [Department of Bioengineering, National University of Singapore (Singapore); Lim, Chwee Teck [Department of Bioengineering, National University of Singapore (Singapore) [Department of Bioengineering, National University of Singapore (Singapore); Department of Mechanical Engineering, National University of Singapore (Singapore); Mechanobiology Institute, National University of Singapore (Singapore); Singapore-MIT Alliance for Research and Technology (SMART), National University of Singapore (Singapore); Lee, Taeyong, E-mail: bielt@nus.edu.sg [Department of Bioengineering, National University of Singapore (Singapore)] [Department of Bioengineering, National University of Singapore (Singapore)

    2012-07-06T23:59:59.000Z

    Highlights: Black-Right-Pointing-Pointer Estradiol induced stiffness changes of osteoblasts were quantified using AFM. Black-Right-Pointing-Pointer Estradiol causes significant decrease in the stiffness of osteoblasts. Black-Right-Pointing-Pointer Decreased stiffness was caused by decreased density of f-actin network. Black-Right-Pointing-Pointer Stiffness changes were not associated with mineralized matrix of osteoblasts. Black-Right-Pointing-Pointer Estradiol increases inherent alkaline phosphatase activity of osteoblasts. -- Abstract: Estrogen is known to have a direct effect on bone forming osteoblasts and bone resorbing osteoclasts. The cellular and molecular effects of estrogen on osteoblasts and osteoblasts-like cells have been extensively studied. However, the effect of estrogen on the mechanical property of osteoblasts has not been studied yet. It is important since mechanical property of the mechanosensory osteoblasts could be pivotal to its functionality in bone remodeling. This is the first study aimed to assess the direct effect of estradiol on the apparent elastic modulus (E{sup Asterisk-Operator }) and corresponding cytoskeletal changes of human fetal osteoblasts (hFOB 1.19). The cells were cultured in either medium alone or medium supplemented with {beta}-estradiol and then subjected to Atomic Force Microscopy indentation (AFM) to determine E{sup Asterisk-Operator }. The underlying changes in cytoskeleton were studied by staining the cells with TRITC-Phalloidin. Following estradiol treatment, the cells were also tested for proliferation, alkaline phosphatase activity and mineralization. With estradiol treatment, E{sup Asterisk-Operator} of osteoblasts significantly decreased by 43-46%. The confocal images showed that the changes in f-actin network observed in estradiol treated cells can give rise to the changes in the stiffness of the cells. Estradiol also increases the inherent alkaline phosphatase activity of the cells. Estradiol induced stiffness changes of osteoblasts were not associated with changes in the synthesized mineralized matrix of the cells. Thus, a decrease in osteoblast stiffness with estrogen treatment was demonstrated in this study, with positive links to cytoskeletal changes. The estradiol associated changes in osteoblast mechanical properties could bear implications for bone remodeling and its mechanical integrity.

  4. The mechanical properties of T-111 at low to intermediate temperatures

    SciTech Connect (OSTI)

    McCoy, H.E.; DiStefano, J.R.

    1997-01-01T23:59:59.000Z

    In the design of the 60-W Isotopic Heat Source (IHS), a tantalum alloy (T-111) strength member serves as the primary containment shell for the IHS during operation (He-gas internal environment and inert gas or vacuum external environment). An outer Hastelloy S clad is used to protect the T-111 from oxidation, and both the Hastelloy S clad and the T-111 strength member are sealed by automatic gas tungsten arc (GTA) welding. The expected life of the IHS is 5 years at about 650 C preceded by up to 5 years of storage at approximately 300 C. For this application, one important concern is failure of the T-111 strength member due to capsule pressurization arising from helium generation as a fuel decay product. To provide specific data on the mechanical behavior of base and solid metal T-111 under conditions appropriate to the IHS use conditions, a testing program was formulated and carried out. Three types of mechanical tests were conducted. Tensile properties were measured over the temperature range of 25 to 1100 C on T-111 base metal and samples with either longitudinal or transverse autogenous welds. Creep tests on base metal and samples with transverse welds were run to failure over the temperature range of 1100 to 850 C. Creep tests were also run on several transverse weld samples over the temperature range of 500 to 900 C at stresses where failure did not occur, and the creep rates were measured. Two prototypical capsules of the T-111 strength member were fabricated by EG and G Mound Applied Technologies (Mound Laboratories). To verify the mechanical properties design data developed above, these were tested to failure (leak) in a vacuum chamber with the inside of the capsule pressurized by either argon or helium.

  5. Quantum mechanics based force field for carbon ,,QMFF-Cx... validated to reproduce the mechanical and thermodynamics properties

    E-Print Network [OSTI]

    Goddard III, William A.

    Quantum mechanics based force field for carbon ,,QMFF-Cx... validated to reproduce the mechanical mechanics based force field for carbon QMFF-Cx by fitting to results from density functional theory . A third, eclipsed geometry is calculated to be much higher in energy. The QMFF-Cx force field leads

  6. The corrosion and corrosion mechanical properties evaluation for the LBB concept in VVERs

    SciTech Connect (OSTI)

    Ruscak, M.; Chvatal, P.; Karnik, D.

    1997-04-01T23:59:59.000Z

    One of the conditions required for Leak Before Break application is the verification that the influence of corrosion environment on the material of the component can be neglected. Both the general corrosion and/or the initiation and, growth of corrosion-mechanical cracks must not cause the degradation. The primary piping in the VVER nuclear power plant is made from austenitic steels (VVER 440) and low alloy steels protected with the austenitic cladding (VVER 1000). Inspection of the base metal and heterogeneous weldments from the VVER 440 showed that the crack growth rates are below 10 m/s if a low oxygen level is kept in the primary environment. No intergranular cracking was observed in low and high oxygen water after any type of testing, with constant or periodic loading. In the framework of the LBB assessment of the VVER 1000, the corrosion and corrosion mechanical properties were also evaluated. The corrosion and corrosion mechanical testing was oriented predominantly to three types of tests: stress corrosion cracking tests corrosion fatigue tests evaluation of the resistance against corrosion damage. In this paper, the methods used for these tests are described and the materials are compared from the point of view of response on static and periodic mechanical stress on the low alloyed steel 10GN2WA and weld metal exposed in the primary circuit environment. The slow strain rate tests and static loading of both C-rings and CT specimens were performed in order to assess the stress corrosion cracking characteristics. Cyclic loading of CT specimens was done to evaluate the kinetics of the crack growth under periodical loading. Results are shown to illustrate the approaches used. The data obtained were evaluated also from the point of view of comparison of the influence of different structure on the stress corrosion cracking appearance. The results obtained for the base metal and weld metal of the piping are presented here.

  7. Structural, electronic, mechanical, and dynamical properties of graphene oxides: A first principles study

    SciTech Connect (OSTI)

    Dabhi, Shweta D. [Department of Physics, Maharaja Krishnakumarsinhji Bhavnagar University, Bhavnagar 364001 (India); Gupta, Sanjay D. [V. B. Institute of Science, Department of Physics, C. U. Shah University, Wadhwan City - 363030, Surendranagar (India); Jha, Prafulla K., E-mail: prafullaj@yahoo.com [Department of Physics, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara-390002 (India)

    2014-05-28T23:59:59.000Z

    We report the results of a theoretical study on the structural, electronic, mechanical, and vibrational properties of some graphene oxide models (GDO, a-GMO, z-GMO, ep-GMO and mix-GMO) at ambient pressure. The calculations are based on the ab-initio plane-wave pseudo potential density functional theory, within the generalized gradient approximations for the exchange and correlation functional. The calculated values of lattice parameters, bulk modulus, and its first order pressure derivative are in good agreement with other reports. A linear response approach to the density functional theory is used to derive the phonon frequencies. We discuss the contribution of the phonons in the dynamical stability of graphene oxides and detailed analysis of zone centre phonon modes in all the above mentioned models. Our study demonstrates a wide range of energy gap available in the considered models of graphene oxide and hence the possibility of their use in nanodevices.

  8. Tunable mechanical and thermal properties of ZnS/CdS core/shell nanowires

    E-Print Network [OSTI]

    Mandal, Taraknath; Maiti, Prabal K

    2015-01-01T23:59:59.000Z

    Using all atom molecular dynamics (MD) simulations, we have studied the mechanical properties of ZnS/CdS core/shell nanowires. Our results show that the coating of a few atomic layer CdS shell on the ZnS nanowire leads to a significant change in the stiffness of the core/shell nanowires compared to the stiffness of pure ZnS nanowires. The binding energy between the core and shell region decreases due to the lattice mismatch at the core-shell interface. This reduction in binding energy plays an important role in determining the stiffness of a core/shell nanowire. We have also investigated the effects of the shell on the thermal conductivity and melting behavior of the nanowires.

  9. Mechanical properties of granular materials: A variational approach to grain-scale simulations

    SciTech Connect (OSTI)

    Holtzman, R.; Silin, D.B.; Patzek, T.W.

    2009-01-15T23:59:59.000Z

    The mechanical properties of cohesionless granular materials are evaluated from grain-scale simulations. A three-dimensional pack of spherical grains is loaded by incremental displacements of its boundaries. The deformation is described as a sequence of equilibrium configurations. Each configuration is characterized by a minimum of the total potential energy. This minimum is computed using a modification of the conjugate gradient algorithm. Our simulations capture the nonlinear, path-dependent behavior of granular materials observed in experiments. Micromechanical analysis provides valuable insight into phenomena such as hysteresis, strain hardening and stress-induced anisotropy. Estimates of the effective bulk modulus, obtained with no adjustment of material parameters, are in agreement with published experimental data. The model is applied to evaluate the effects of hydrate dissociation in marine sediments. Weakening of the sediment is quantified as a reduction in the effective elastic moduli.

  10. ALD Functionalized Nanoporous Gold: Thermal Stability, Mechanical Properties, and Catalytic Activity

    SciTech Connect (OSTI)

    Biener, M M; Biener, J; Wichmann, A; Wittstock, A; Baumann, T F; Baeumer, M; Hamza, A V

    2011-03-24T23:59:59.000Z

    Nanoporous metals have many technologically promising applications but their tendency to coarsen limits their long-term stability and excludes high temperature applications. Here, we demonstrate that atomic layer deposition (ALD) can be used to stabilize and functionalize nanoporous metals. Specifically, we studied the effect of nanometer-thick alumina and titania ALD films on thermal stability, mechanical properties, and catalytic activity of nanoporous gold (np-Au). Our results demonstrate that even only one-nm-thick oxide films can stabilize the nanoscale morphology of np-Au up to 1000 C, while simultaneously making the material stronger and stiffer. The catalytic activity of np-Au can be drastically increased by TiO{sub 2} ALD coatings. Our results open the door to high temperature sensor, actuator, and catalysis applications and functionalized electrodes for energy storage and harvesting applications.

  11. Effect of Organoclay on Compatibilization, Thermal and Mechanical Properties of Polycarbonate/Polystyrene Blends

    E-Print Network [OSTI]

    Singh, A K

    2014-01-01T23:59:59.000Z

    Pristine and organoclay modified polycarbonate/polystyrene (PC/PS) blends are prepared using melt-mixing technique. These blends are characterized for their morphology, structural, thermal and mechanical properties. Though our FTIR and XRD results show weak interactions between PC and PS phases, however, DSC and morphological study reveals that pristine PC/PS blends are immiscible. On other hand, introduction of organoclay results compatibilization of two polymer phases which is supported by significant shift in glass transition temperatures of the component phases and a distinct morphology having no phase segregation on sub-micron scale. Intercalation of polymers inside the clay gallery is achieved and is supported by XRD studies. A better thermal stability and higher value of modulus of the compatibilized blends compared to pristine PC/PS blends also support the reinforcement effect of organoclay to the PC/PS blend matrix.

  12. High-pressure mechanical and sonic properties of a Devonian shale from West Virginia

    SciTech Connect (OSTI)

    Heard, H.C.; Lin, W.

    1986-01-01T23:59:59.000Z

    Static mechanical properties and sonic velocities were determined on each of four members of the Devonian shale from Columbia Gas Transmission's well 20403, Huntington, West Virginia. They were: Pressure - volume data to 4.0 GPa; Compressive strength at confining pressures up to 300 MPa, both parallel and perpendicular to bedding. Extensile strength at 100 to 700 MPa confining pressure, both parallel and perpendicular to bedding. Loading and unloading path in uniaxial strain at 20 to 500 MPa confining pressure, both parallel and perpendicular to bedding. Tensile strength at ambient pressure, parallel and perpendicular to bedding. Shear and compressional wave velocities at confining pressures up to 1000 MPa parallel, at 45/sup 0/, and perpendicular to bedding. Results are presented and discussed. 32 refs., 10 figs., 10 tabs.

  13. Thermal-mechanical Properties of Epoxy-impregnated Bi-2212/Ag Composite

    SciTech Connect (OSTI)

    Li, Pei; Wang, Yang; Godeke, Arno; Ye, Liyang; Flanagan, Gene; Shen, Tengming

    2014-11-26T23:59:59.000Z

    Knowledge of the thermal-mechanical properties of epoxy/superconductor/insulation composite is important for designing, fabricating, and operating epoxy impregnated high field superconducting magnets near their ultimate potentials. We report measurements of the modulus of elasticity, Poisson’s ratio, and the coefficient of thermal contraction of epoxy-impregnated composite made from the state-of-the-art powder-in-tube multifilamentary Ag/Bi2Sr2CaCu2Ox round wire at room temperature and cryogenic temperatures. Stress-strain curves of samples made from single-strand and Rutherford cables were tested under both monotonic and cyclic compressive loads, with single strands insulated using a thin TiO2 insulation coating and the Rutherford cable insulated with a braided ceramic sleeve.

  14. Alloying effects on mechanical and metallurgical properties of NiAl

    SciTech Connect (OSTI)

    Liu, C.T.; Horton, J.A.; Lee, E.H.; George, E.P.

    1993-06-01T23:59:59.000Z

    Alloying effects were investigated in near-stoichiometric NiAl for improving its mechanical and metallurgical properties. Ternary additions of 19 elements at levels up to 10 at. % were added to NiAl; among them, molybdenum is found to be most effective in improving the room-temperature ductility and high-temperature strength. Alloying with 1.0 {plus_minus} 0.6% molybdenum almost doubles the room-temperature tensile ductility of NiAl and triples its yield strength at 1000C. The creep properties of molybdenum-modified NiAl alloys can be dramatically improved by alloying with up to 1% of niobium or tantalum. Because of the low solubilities of molybdenum and niobium in NiAl, the beneficial effects mainly come from precipitation hardening. Fine and coarse precipitates are revealed by both transmission electron microscopy (TEM) and electron microprobe analyses. Molybdenum-containing alloys possess excellent oxidation resistance and can be fabricated into rod stock by hot extrusion at 900 to 1050C. This study of alloying effects provides a critical input for the alloy design of ductile and strong NiAl aluminide alloys for high-temperature structural applications.

  15. Tuning Structural and Mechanical Properties of Two-Dimensional Molecular Crystals: The Roles of Carbon Side Chains

    SciTech Connect (OSTI)

    Cun, Huanyao (HY) [Institute of Physics, Chinese Academy of Science; Wang, Yeliang (YL) [Institute of Physics, Chinese Academy of Science; Du, S X [Chinese Academy of Sciences; Zhang, Lei [Institute of Physics, Chinese Academy of Science; Zhang, Lizhi [Institute of Physics, Chinese Academy of Science; Yang, Bing [Institute of Physics, Chinese Academy of Science; He, Xiaobo [Institute of Physics, Chinese Academy of Science; Wang, Yue [Jilin University, Changchun; Zhu, Xueyan [Chinese Academy of Sciences; Yuan, Quanzi [Chinese Academy of Sciences; Zhao, Ya-Pu [Chinese Academy of Sciences; Ouyang, Min [University of Maryland; Hofer, Werner A. [University of Liverpool; Pennycook, Stephen J [ORNL; Gao, Hong-jun [Institute of Physics, Chinese Academy of Science

    2012-01-01T23:59:59.000Z

    A key requirement for the future applicability of molecular electronics devices is a resilience of their properties to mechanical deformation. At present, however, there is no fundamental understanding of the origins of mechanical properties of molecular films. Here we use quinacridone, which possesses flexible carbon side chains, as a model molecular system to address this issue. Eight molecular configurations with different molecular coverage are identified by scanning tunneling microscopy. Theoretical calculations reveal quantitatively the roles of different molecule-molecule and molecule-substrate interactions and predict the observed sequence of configurations. Remarkably, we find that a single Young's modulus applies for all configurations, the magnitude of which is controlled by side chain length, suggesting a versatile avenue for tuning not only the physical and chemical properties of molecular films but also their elastic properties.

  16. INITIAL COMPARISON OF BASELINE PHYSICAL AND MECHANICAL PROPERTIES FOR THE VHTR CANDIDATE GRAPHITE GRADES

    SciTech Connect (OSTI)

    Carroll, Mark C

    2014-09-01T23:59:59.000Z

    High-purity graphite is the core structural material of choice in the Very High Temperature Reactor (VHTR) design, a graphite-moderated, helium-cooled configuration that is capable of producing thermal energy for power generation as well as process heat for industrial applications that require temperatures higher than the outlet temperatures of present nuclear reactors. The Baseline Graphite Characterization Program is endeavoring to minimize the conservative estimates of as-manufactured mechanical and physical properties in nuclear-grade graphites by providing comprehensive data that captures the level of variation in measured values. In addition to providing a thorough comparison between these values in different graphite grades, the program is also carefully tracking individual specimen source, position, and orientation information in order to provide comparisons both in specific properties and in the associated variability between different lots, different billets, and different positions from within a single billet. This report is a preliminary comparison between each of the grades of graphite that are considered “candidate” grades from four major international graphite producers. These particular grades (NBG-18, NBG-17, PCEA, IG-110, and 2114) are the major focus of the evaluations presently underway on irradiated graphite properties through the series of Advanced Graphite Creep (AGC) experiments. NBG-18, a medium-grain pitch coke graphite from SGL from which billets are formed via vibration molding, was the favored structural material in the pebble-bed configuration. NBG-17 graphite from SGL is essentially NBG-18 with the grain size reduced by a factor of two. PCEA, petroleum coke graphite from GrafTech with a similar grain size to NBG-17, is formed via an extrusion process and was initially considered the favored grade for the prismatic layout. IG-110 and 2114, from Toyo Tanso and Mersen (formerly Carbone Lorraine), respectively, are fine-grain grades produced via an isomolding process. An analysis of the comparison between each of these grades will include not only the differences in fundamental and statistically-significant individual strength levels, but also the differences in variability in properties within each of the grades that will ultimately provide the basis for the prediction of in-service performance. The comparative performance of the different types of nuclear-grade graphites will continue to evolve as thousands more specimens are fully characterized from the numerous grades of graphite being evaluated.

  17. Predicting the Operating Behavior of Ceramic Filters from Thermo-Mechanical Ash Properties

    SciTech Connect (OSTI)

    Hemmer, G.; Kasper, G.

    2002-09-19T23:59:59.000Z

    Stable operation, in other words the achievement of a succession of uniform filtration cycles of reasonable length is a key issue in high-temperature gas filtration with ceramic media. Its importance has rather grown in recent years, as these media gain in acceptance due to their excellent particle retention capabilities. Ash properties have been known for some time to affect the maximum operating temperature of filters. However, softening and consequently ''stickiness'' of the ash particles generally depend on composition in a complex way. Simple and accurate prediction of critical temperature ranges from ash analysis--and even more so from coal analysis--is still difficult without practical and costly trials. In general, our understanding of what exactly happens during break-down of filtration stability is still rather crude and general. Early work was based on the concept that ash particles begin to soften and sinter near the melting temperatures of low-melting, often alkaline components. This softening coincides with a fairly abrupt increase of stickiness, that can be detected with powder mechanical methods in a Jenicke shear cell as first shown by Pilz (1996) and recently confirmed by others (Kamiya et al. 2001 and 2002, Kanaoka et al. 2001). However, recording {sigma}-{tau}-diagrams is very time consuming and not the only off-line method of analyzing or predicting changes in thermo-mechanical ash behavior. Pilz found that the increase in ash stickiness near melting was accompanied by shrinkage attributed to sintering. Recent work at the University of Karlsruhe has expanded the use of such thermo-analytical methods for predicting filtration behavior (Hemmer 2001). Demonstrating their effectiveness is one objective of this paper. Finally, our intent is to show that ash softening at near melting temperatures is apparently not the only phenomenon causing problems with filtration, although its impact is certainly the ''final catastrophe''. There are other significant changes in regeneration at intermediate temperatures, which may lead to long-term deterioration.

  18. Microstructure, microstructural stability and mechanical properties of sand-cast Mg–4Al–4RE alloy

    SciTech Connect (OSTI)

    Rzycho?, Tomasz, E-mail: tomasz.rzychon@polsl.pl [Silesian University of Technology, Faculty of Materials Science and Metallurgy, Krasi?skiego 8, 40 019 Katowice (Poland); Kie?bus, Andrzej [Silesian University of Technology, Faculty of Materials Science and Metallurgy, Krasi?skiego 8, 40 019 Katowice (Poland); Lity?ska-Dobrzy?ska, Lidia [Polish Academy of Sciences, Institute of Metallurgy and Materials Science, 25 Reymonta Street, 30-059 Kraków (Poland)

    2013-09-15T23:59:59.000Z

    This paper presents a methodology for assessing the phase composition and the results of structural stability tests of the sand-cast Mg–4Al–4RE alloy after annealing it at 175 and 250 °C for 3000 h. The microstructure was analyzed with optical, scanning electron, and transmission electron microscopy. The phase composition was determined with X-ray diffraction. The structure of the Mg–4Al–4RE (AE44) alloy is composed of large grains of ?-Mg solid solution, needle-shaped precipitates of the Al{sub 11}RE{sub 3}phase, polyhedral precipitates of the Al{sub 2}RE phase and Al{sub 10}RE{sub 2}Mn{sub 7} phase. After annealing at 175 °C for 3000 h, no changes in the alloy structure are observed, whereas after annealing at 250 °C the precipitates of the Al{sub 11}RE{sub 3} phase are found to be in the initial stages of spheroidization. The coarse-grained structure and unfavorable morphology of the intermetallic phases in the sand-cast AE44 alloy, which are caused by low solidification rates, result in low creep resistance up to 200 °C and low mechanical properties at ambient temperature and at 175 °C. - Highlights: • Complement the knowledge about the microstructure of Mg-Al-RE alloys. • Clarify the mechanism of formation of Mg17Al12 phase above 180 °C. • Applying a chemical dissolution of the ?-Mg in order to phase identification. • Applying a statistical test to assess the spheroidization of precipitates. • Quantitative description of microstructure of Mg-Al-RE alloys.

  19. Microstructure and mechanical properties of Ti-40 wt pct Ta (Ti-15 at. pct Ta)

    SciTech Connect (OSTI)

    Cotton, J.D.; Bingert, J.F.; Dunn, P.S.; Patterson, R.A. (Los Alamos National Lab., NM (United States))

    1994-03-01T23:59:59.000Z

    Of the [beta]-isomorphous Ti-X alloy systems, Ti-Ta is one of the least studied. In the current work, the microstructure and mechanical properties of Ti-40 wt pct Ta (Ti-15 at. pct Ta) are investigated. Annealing at 810 C produces a two-phase microstructure consisting of Ti-rich [alpha] idiomorphs in a continuous Ta-rich [beta] matrix; this suggest the [beta]-transus temperature is higher than indicated by the most recently published phase diagram. Water quenching from 810 C caused the [beta] phase to partially transform to orthorhombic martensite ([alpha][double prime]), while furnace cooling yields secondary [alpha]. The primary [alpha] formed isothermally remains unchanged in both cases. Subsequent aging causes transformation of the martensite to type 1 [alpha] plus residual [beta], with a corresponding increase in strength and decrease in ductility. The maximum ductility (20 pct elongation) occurs in the water-quenched condition in which metastable [beta] is retained. Analysis of the true stress-true strain data suggests that transformation-induced plasticity may contribute to the enhanced ductility of the water-quenched material.

  20. On the Mechanical Properties and Microstructure of Nitinol forBiomedical Stent Applications

    SciTech Connect (OSTI)

    Robertson, Scott W.

    2006-12-15T23:59:59.000Z

    This dissertation was motivated by the alarming number of biomedical device failures reported in the literature, coupled with the growing trend towards the use of Nitinol for endovascular stents. The research is aimed at addressing two of the primary failure modes in Nitinol endovascular stents: fatigue-crack growth and overload fracture. The small dimensions of stents, coupled with their complex geometries and variability among manufacturers, make it virtually impossible to determine generic material constants associated with specific devices. Instead, the research utilizes a hybrid of standard test techniques (fracture mechanics and x-ray micro-diffraction) and custom-designed testing apparatus for the determination of the fracture properties of specimens that are suitable representations of self-expanding Nitinol stents. Specifically, the role of texture (crystallographic alignment of atoms) and the austenite-to-martensite phase transformation on the propagation of cracks in Nitinol was evaluated under simulated body conditions and over a multitude of stresses and strains. The results determined through this research were then used to create conservative safe operating and inspection criteria to be used by the biomedical community for the determination of specific device vulnerability to failure by fracture and/or fatigue.

  1. Property of Zero-Energy Flows and Creations and Annihilations of Vortices in Quantum Mechanics

    E-Print Network [OSTI]

    Tsunehiro Kobayashi

    2003-01-09T23:59:59.000Z

    Time-dependent processes accompanied by vortex creations and annihilations are investigated in terms of the eigenstates in conjugate spaces of Gel'fand triplets in 2-dimensions. Creations and annihilations of vortices are described by the insertions of unstable eigenstates with complex-energy eigenvalues into stable states written by the superposition of eigenstates with zero-energy eigenvalues. Some concrete examples are presented in terms of the eigenfunctions of the 2-dimensional parabolic potential barrier, i.e., $-m \\gamma^2 (x^2+y^2)/2$. We show that the processes accompanied by vortex creations and annihilations can be analyzed in terms of the eigenfunctions in the conjugate spaces of Gel'fand triplets. Throughout these examinations we point out three interesting properties of the zero-energy flows. (i) Mechanisms using the zero-energy flows are absolutely economical from the viewpoint of energy consumption. (ii) An enormous amount of informations can be discriminated in terms of the infinite variety of the zero-energy flows. (iii) The zero-energy flow patterns are absolutely stable in any disturbance by inserting arbitrary decaying flows with complex-energy eigenvalues.

  2. Materials Science and Engineering A 485 (2008) 681689 Effect of strain rate on the compressive mechanical properties

    E-Print Network [OSTI]

    Meyers, Marc A.

    mechanical properties of aluminum alloy matrix composite filled with discontinuous carbon fibers Jing Caia to investigate the quasi-static and dynamic response of carbon fiber/Al­Mg composites. Two types of carbon fibers rights reserved. Keywords: Carbon fiber reinforced Al matrix composite; High-strain rate deformation 1

  3. The Influences of Fiber Feature and Polymer Melt Index on Mechanical Properties of Sugarcane Fiber/Polymer

    E-Print Network [OSTI]

    The Influences of Fiber Feature and Polymer Melt Index on Mechanical Properties of Sugarcane Fiber/Polymer.interscience.wiley.com). ABSTRACT: The fiber characteristics (i.e., the fiber type, morphology, and dimension) and polymer melt flow sugarcane fiber/polymer composites, the HDPE resins with a low MFI value presented high tensile and impact

  4. 46.1 Shear Viscosity An important mechanical property of fluids is viscosity. Physical systems and applications as diverse as

    E-Print Network [OSTI]

    Kostic, Milivoje M.

    46-1 46.1 Shear Viscosity An important mechanical property of fluids is viscosity. Physical systems involve fluid flow and are controlled to some degree by fluid viscosity. Viscosity is the tendency, viscosity is related to molecular dif- fusion and depends on the interactions between molecules or

  5. Investigation of microstructure and mechanical properties of multi-layer Cr/Cr2O3 coatings

    E-Print Network [OSTI]

    Volinsky, Alex A.

    as a selective solar ray collector and for other applications as a protective coating against wear, corrosionInvestigation of microstructure and mechanical properties of multi-layer Cr/Cr2O3 coatings Xiaolu-layer Microstructure Fracture toughness Adhesion Single and multi-layer Cr/Cr2O3 coatings were deposited by reactive

  6. Microstructure and mechanical properties of thermoelectric nanostructured n-type silicon-germanium alloys synthesized employing spark plasma sintering

    SciTech Connect (OSTI)

    Bathula, Sivaiah [CSIR-Network of Institutes for Solar Energy, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Department of Applied Physics, Delhi Technological University, Delhi (India); Gahtori, Bhasker; Tripathy, S. K.; Tyagi, Kriti; Srivastava, A. K.; Dhar, Ajay, E-mail: adhar@nplindia.org [CSIR-Network of Institutes for Solar Energy, CSIR-National Physical Laboratory, Dr. K. S. Krishnan Marg, New Delhi 110012 (India); Jayasimhadri, M. [Department of Applied Physics, Delhi Technological University, Delhi (India)

    2014-08-11T23:59:59.000Z

    Owing to their high thermoelectric (TE) figure-of-merit, nanostructured Si{sub 80}Ge{sub 20} alloys are evolving as a potential replacement for their bulk counterparts in designing efficient radio-isotope TE generators. However, as the mechanical properties of these alloys are equally important in order to avoid in-service catastrophic failure of their TE modules, we report the strength, hardness, fracture toughness, and thermal shock resistance of nanostructured n-type Si{sub 80}Ge{sub 20} alloys synthesized employing spark plasma sintering of mechanically alloyed nanopowders of its constituent elements. These mechanical properties show a significant enhancement, which has been correlated with the microstructural features at nano-scale, delineated by transmission electron microscopy.

  7. Effect of n-HA content on the isothermal crystallization, morphology and mechanical property of n-HA/PLGA composites

    SciTech Connect (OSTI)

    Liuyun, Jiang, E-mail: jlytxg@163.com [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Chengdong, Xiong [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Lixin, Jiang [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China); Graduated School of Chinese Academy of Sciences, Beijing 100039 (China); Dongliang, Chen; Qing, Li [Chengdu Institute of Organic Chemistry, Chinese Academy of Sciences, Chengdu 610041 (China)

    2013-03-15T23:59:59.000Z

    Graphical abstract: Effect of n-HA content on the isothermal crystallization, morphology and mechanical property of n-HA/PLGA composites was studied in details. The results showed that the addition of higher content of g-n-HA was favorable to promote the crystallization better in g-n-HA/PLGA composites, but it could also cause more agglomeration in PLGA matrix, as a result of worse mechanical properties, and the addition content of 3 wt% g-n-HA to PLGA matrix was an appropriate proportion, which had the highest bending strength among these g-n-HA/PLGA composites, and it might be potential to be used in biomedical fields in future. Highlights: ? The effect of n-HA content on the n-HA/PLGA composites was studied in detail. ? Isothermal crystallization, microstructure and mechanical property were studied. ? The relation between n-HA content and properties of n-HA/PLGA composite was found. ? An appropriate proportion of n-HA in n-HA/PLGA composite was obtained. - Abstract: A serials of g-n-HA/PLGA composites with surface-modified g-n-HA of 1%, 3%, 6%, 10% and 15% in weight were prepared by solution mixing. The isothermal crystallization, morphology and mechanical property of g-n-HA/PLGA composites were investigated by differential scanning calorimeter (DSC), scanning electron microscope (SEM) and electromechanical universal tester. The results showed that Avrami equation was suitable for describing the isothermal crystallization process in this system, and the crystallization rate of g-n-HA/PLGA composites containing more than 3 wt% g-n-HA was basically accord with the relational expression of T{sub 110} {sub °C} > T{sub 105°C} > T{sub 115°C} > T{sub 120°C}. Moreover, at the same Tc, crystallization rate was greatly enhanced with the increasing of g-n-HA acting as nucleate. However, the addition of higher content of g-n-HA would cause more agglomeration in PLGA matrix, so that the mechanical properties of g-n-HA/PLGA composites would gradually decrease. In conclusion, the addition of higher content of g-n-HA was favorable to promote the crystallization better in g-n-HA/PLGA composites, but it could also cause more agglomeration in PLGA matrix, result in worse mechanical properties, and the addition content of 3 wt% g-n-HA to PLGA matrix was an appropriate proportion, which had the highest bending strength among these g-n-HA/PLGA composites, and it might be potential to be used in biomedical fields in future.

  8. Impact of controlled particle size nanofillers on the mechanical properties of segmented polyurethane nanocomposites

    SciTech Connect (OSTI)

    Finnigan, Bradley; Casey, Phil; Cookson, David; Halley, Peter; Jack, Kevin; Truss, Rowan; Martin, Darren (Queensland); (UC)

    2008-04-02T23:59:59.000Z

    The impact of average layered silicate particle size on the mechanical properties of thermoplastic polyurethane (TPU) nanocomposites has been investigated. At fixed addition levels (3 wt% organosilicate), an increase in average particle size resulted in an increase in stiffness. Negligible stiffening was observed for the smallest particles (30 nm) due to reduced long-range intercalation and molecular confinement, as well as ineffective stress transfer from matrix to filler. At low strain ({le}100%), an increase in filler particle size was associated with an increase in the rate of stress relaxation, tensile hysteresis, and permanent set. At high strain (1200%), two coexisting relaxation processes were observed. The rate of the slower (long-term) relaxation process, which is believed to primarily involve the hard segment rich structures, decreased on addition of particles with an average diameter of 200 nm or less. At high strain the tensile hysteresis was less sensitive to particle size, however the addition of particles with an average size of 200 nm or more caused a significant increase in permanent set. This was attributed to slippage of temporary bonds at the polymer-filler interface, and to the formation of voids at the sites of unaligned tactoids. Relative to the host TPU, the addition of particles with an average size of 30 nm caused a reduction in permanent set. This is a significant result because the addition of fillers to elastomers has long been associated with an increase in hysteresis and permanent set. At high strain, well dispersed and aligned layered silicates with relatively small interparticle distances and favourable surface interactions are capable of imparting a resistance to molecular slippage throughout the TPU matrix.

  9. Microstructure and Mechanical Property Studies on Neutron-Irradiated Ferritic Fe-Cr Model Alloys

    SciTech Connect (OSTI)

    Jian Gan; Maria Okuniewski; Wei-Ying Chen; Yinbin Miao; Carolyn A. Tomchik; James F. Stubbins; Y. Q. Wu; Stu A. Maloy

    2014-06-01T23:59:59.000Z

    Model Fe, Fe-10Cr and Fe-14Cr alloys were irradiated in Advanced Test Reactor at 300°C and 450°C to target doses of 0.01, 0.1 and 1 dpa. The microstructure and the mechanical property of irradiated specimens were investigated using TEM, APT and hardness measurements. The irradiation-induced hardening was consistent with the observed microstructures. For lower doses of 0.01 and 0.1 dpa, the formation of dislocation loops was the primarily contributor to the hardening; no a’ precipitates of resolvable sizes were observed. By 1 dpa, additional increase in hardening were attributed to the formation of a high density of 1-2 nm a' precipitates. In Fe, the hardness increased less as a function of irradiation dose compared to Fe-Cr alloys because of the lack of a' precipitation and differences in loop structures. Three single-parameter effects have been studied: the Cr content, the irradiation temperature and the grain size. The addition of Cr reduced the mobility of both ½<111> and <100> dislocation loops, leading to a smaller loop size and higher loop density. Also, the Cr contents were positively correlated to the density of a' precipitates, but were less relevant to the precipitate size. Higher irradiation temperature of 450°C resulted in a preferential production of the immobile <100> loops over the mobile ½<111> loops (ex. a ratio of 8:1 in Fe-10Cr irradiated 450°C to 0.01 dpa). At lower temperature of 300°C, heterogeneous formation of dislocation loops at the vicinity of line dislocations frequently. In Fe, the development of dislocation loops was suppressed (compared to Fe-Cr alloys) due to a combination of smaller grain size, high initial dislocation density and high defect mobility.

  10. Dose dependence of mechanical properties in tantalum and tantalum alloys after low temperature irradiation

    SciTech Connect (OSTI)

    Byun, Thak Sang [ORNL

    2008-01-01T23:59:59.000Z

    The dose dependence of mechanical properties was investigated for tantalum and tantalum alloys after low temperature irradiation. Miniature tensile specimens of three pure tantalum metals, ISIS Ta, Aesar Ta1, Aesar Ta2, and one tantalum alloy, Ta-1W, were irradiated by neutrons in the High Flux Isotope Reactor (HFIR) at ORNL to doses ranging from 0.00004 to 0.14 displacements per atom (dpa) in the temperature range 60 C 100 oC. Also, two tantalum-tungsten alloys, Ta-1W and Ta-10W, were irradiated by protons and spallation neutrons in the LANSCE facility at LANL to doses ranging from 0.7 to 7.5 dpa and from 0.7 to 25.2 dpa, respectively, in the temperature range 50 C 160 oC. Tensile tests were performed at room temperature and at 250oC at nominal strain rates of about 10-3 s-1. All neutron-irradiated materials underwent progressive irradiation hardening and loss of ductility with increasing dose. The ISIS Ta experienced embrittlement at 0.14 dpa, while the other metals retained significant necking ductility. Such a premature embrittlement in ISIS Ta is believed to be because of high initial oxygen concentrations picked up during a pre-irradiation anneal. The Ta-1W and Ta-10W specimens irradiated in spallation condition experienced prompt necking at yield since irradiation doses for those specimens were high ( 0.7 dpa). At the highest dose, 25.2 dpa, the Ta-10W alloy specimen broke with little necking strain. Among the test materials, the Ta-1W alloy displayed the best combination of strength and ductility. The plastic instability stress and true fracture stress were nearly independent of dose. Increasing test temperature decreased strength and delayed the onset of necking at yield.

  11. Mechanical properties of jammed packings of frictionless spheres under applied shear stress

    E-Print Network [OSTI]

    Hao Liu; Hua Tong; Ning Xu

    2015-02-03T23:59:59.000Z

    By minimizing a thermodynamic-like potential, we unbiasedly sample the potential energy landscape of soft and frictionless spheres under constant shear stress. We obtain zero-temperature jammed states under desired shear stresses and investigate their mechanical properties as a function of the shear stress. As a comparison, we also obtain jammed states from the quasistatic-shear sampling in which the shear stress is not well-controlled. Although the yield stresses determined by both samplings show the same power-law scaling with the compression from point $J$, i.e.~the jamming transition point at zero temperature and shear stress, for finite size systems, the quasistatic-shear sampling leads to a lower yield stress and a higher critical volume fraction of point $J$. The shear modulus of jammed solids decreases when increasing the shear stress. However, the shear modulus does not decay to zero at yielding. This discontinuous change of the shear modulus implies the discontinuous nature of the unjamming transition under nonzero shear stress, which is further verified by the observation of a discontinuous jump of the pressure from jammed solids to shear flows. The pressure jump decreases upon decompression and approaches zero at the critical-like point $J$, in analogy with well-known phase transitions under external field. The analysis of force networks in jammed solids reveals that the force distribution is more sensitive to the increase of the shear stress near point $J$. The force network anisotropy increases with the shear stress. Weak particle contacts near the average force and under large shear stresses exhibit asymmetric angle distribution.

  12. Effect of chemical mechanical planarization processing conditions on polyurethane pad properties

    E-Print Network [OSTI]

    Ng, Grace Siu-Yee, 1980-

    2003-01-01T23:59:59.000Z

    Chemical Mechanical Planarization (CMP) is a vital process used in the semiconductor industry to isolate and connect individual transistors on a chip. However, many of the fundamental mechanisms of the process are yet to ...

  13. Mechano-growth factor induces migration of rat mesenchymal stem cells by altering its mechanical properties and activating ERK pathway

    SciTech Connect (OSTI)

    Wu, Jiamin; Wu, Kewen; Lin, Feng; Luo, Qing; Yang, Li; Shi, Yisong [Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044 (China)] [Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044 (China); Song, Guanbin, E-mail: song@cqu.edu.cn [Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044 (China)] [Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044 (China); Sung, Kuo-Li Paul [Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044 (China) [Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing 400044 (China); Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093-0412 (United States)

    2013-11-08T23:59:59.000Z

    Highlights: •MGF induced the migration of rat MSC in a concentration-dependent manner. •MGF enhanced the mechanical properties of rMSC in inducing its migration. •MGF activated the ERK 1/2 signaling pathway of rMSC in inducing its migration. •rMSC mechanics may synergy with ERK 1/2 pathway in MGF-induced rMSC migration. -- Abstract: Mechano-growth factor (MGF) generated by cells in response to mechanical stimulation has been identified as a mechano effector molecule, playing a key role in regulating mesenchymal stem cell (MSC) function, including proliferation and migration. However, the mechanism(s) underlying how MGF-induced MSC migration occurs is still unclear. In the present study, MGF motivated migration of rat MSCs (rMSCs) in a concentration-dependent manner and optimal concentration of MGF at 50 ng/mL (defined as MGF treatment in this paper) was demonstrated. Notably, enhancement of mechanical properties that is pertinent to cell migration, such as cell traction force and cell stiffness were found to respond to MGF treatment. Furthermore, MGF increased phosphorylation of extracellular signal-regulated kinase (ERK), ERK inhibitor (i.e., PD98059) suppressed ERK phosphorylation, and abolished MGF-induced rMSC migration were found, demonstrating that ERK is involved molecule for MGF-induced rMSC migration. These in vitro evidences of MGF-induced rMSC migration and its direct link to altering rMSC mechanics and activating the ERK pathway, uncover the underlying biomechanical and biological mechanisms of MGF-induced rMSC migration, which may help find MGF-based application of MSC in clinical therapeutics.

  14. Microstructure factor and mechanical and electronic properties of hydrogenated amorphous and nanocrystalline silicon thin-films for microelectromechanical systems applications

    SciTech Connect (OSTI)

    Mouro, J.; Gualdino, A.; Chu, V. [Instituto de Engenharia de Sistemas e Computadores – Microsistemas e Nanotecnologias (INESC-MN) and IN – Institute of Nanoscience and Nanotechnology, 1000-029 Lisbon (Portugal); Conde, J. P. [Instituto de Engenharia de Sistemas e Computadores – Microsistemas e Nanotecnologias (INESC-MN) and IN – Institute of Nanoscience and Nanotechnology, 1000-029 Lisbon (Portugal); Department of Bioengineering, Instituto Superior Técnico (IST), 1049-001 Lisbon (Portugal)

    2013-11-14T23:59:59.000Z

    Thin-film silicon allows the fabrication of MEMS devices at low processing temperatures, compatible with monolithic integration in advanced electronic circuits, on large-area, low-cost, and flexible substrates. The most relevant thin-film properties for applications as MEMS structural layers are the deposition rate, electrical conductivity, and mechanical stress. In this work, n{sup +}-type doped hydrogenated amorphous and nanocrystalline silicon thin-films were deposited by RF-PECVD, and the influence of the hydrogen dilution in the reactive mixture, the RF-power coupled to the plasma, the substrate temperature, and the deposition pressure on the structural, electrical, and mechanical properties of the films was studied. Three different types of silicon films were identified, corresponding to three internal structures: (i) porous amorphous silicon, deposited at high rates and presenting tensile mechanical stress and low electrical conductivity, (ii) dense amorphous silicon, deposited at intermediate rates and presenting compressive mechanical stress and higher values of electrical conductivity, and (iii) nanocrystalline silicon, deposited at very low rates and presenting the highest compressive mechanical stress and electrical conductivity. These results show the combinations of electromechanical material properties available in silicon thin-films and thus allow the optimized selection of a thin silicon film for a given MEMS application. Four representative silicon thin-films were chosen to be used as structural material of electrostatically actuated MEMS microresonators fabricated by surface micromachining. The effect of the mechanical stress of the structural layer was observed to have a great impact on the device resonance frequency, quality factor, and actuation force.

  15. Effect of high-temperature loading on mechanical properties of Nicalon fibers and Nicalon fiber/SiC matrix composites

    SciTech Connect (OSTI)

    Singh, D.; Singh, J.P.

    1993-01-01T23:59:59.000Z

    Results of an investigation into the effect of elevated temperature exposure on the strength distribution of Nicalon fibers as well on mechanical properties of Nicalon/SiC composites are reported in this paper. Single-fiber strength distribution of as-fabricated Nicalon fibers was obtained from bundle tests. Strength distributions of fractured fibers in as-fabricated Nicalon/SiC composites and after elevated temperature exposure of composites were assessed from measurements of fracture mirror radii. Variations in the mechanical properties of composites evaluated as a function of test temperatures are compared with those evaluated at room temperature and are correlated to the fiber strength characteristics. Limited tests were also conducted to investigate the effect of long term exposure at elevated temperatures on composite ultimate strength.

  16. Improved mechanical properties and ozone resistance of radiation-cured SBR. Final report, Dec 88-Jun 91. [Styrene Butadiene Rubber

    SciTech Connect (OSTI)

    Basfar, A.A.; Silverman, J.

    1991-08-01T23:59:59.000Z

    This report is a continuation and extension of the work of the earlier Army contract, where the superiority of the electron beam cured styrene butadiene rubber (SBR) tank pads to the sulfur cured pads was demonstrated. The focus of the present study is the investigation of the extraordinary ozone resistance of our radiation cured SBR, and also on possible alternatives for SBR, butadiene rubber (BR) in particular, as a tank pad compound. Base formulations of a fully sulfur cured system were established with 5% reproducibility, and results were confirmed by mechanical properties measurements on identical formulations from Belvoir Research Development and Engineering Center (BRDEC). Constant mechanical properties as a function of exposure to ozone indicate either competitive cross-linking and scissioning reactions or a 'protective' effect caused by higher terminal vinyl concentrations in the radiation cured formulations.

  17. Molecular Dynamic Simulation of Thermo-Mechanical Properties of Ultra-Thin Poly(methyl methacrylate) Films

    E-Print Network [OSTI]

    Silva Hernandez, Carlos Ardenis A.

    2011-08-08T23:59:59.000Z

    MOLECULAR DYNAMIC SIMULATION OF THERMO-MECHANICAL PROPERTIES OF ULTRA-THIN POLY(METHYL METHACRYLATE) FILMS A Dissertation by CARLOS ARDENIS SILVA HERNANDEZ Submitted to the Office of Graduate Studies of Texas A&M University... A Dissertation by CARLOS ARDENIS SILVA HERNANDEZ Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Approved by: Co-Chairs of Committee...

  18. A Novel Method for the Evaluation of Mechanical Properties of Cancellous Bone in the Rat Distal Femur

    E-Print Network [OSTI]

    Lucas, Matthew W.

    2010-01-14T23:59:59.000Z

    Walton Lucas, B.S., Lipscomb University Co-Chairs of Advisory Committee: Dr. Harry Hogan Dr. Susan Bloomfield The mechanical properties of the cancellous bone in the laboratory rat animal model... the cortical shell for 50 slices in a region starting ~0.5 mm below the most proximal portion of the growth plate for each animal. Images were binarized (threshold of 100 on a 0-255 scale) and the following parameters were assessed for the three- dimensional...

  19. Dissimilar Friction Stir Welds in Al5186-Al2024: The Effect of Process Parameters on Microstructures and Mechanical Properties

    SciTech Connect (OSTI)

    Mousavi, S. A. A. Akbari; ShamAbadi, S. H. [School of Metallurgy and Materials Engineering, University College of Engineering, University of Tehran, Tehran (Iran, Islamic Republic of)

    2011-01-17T23:59:59.000Z

    The effect of tool traverse and rotation speeds on the microstructures and mechanical properties are quantified for welds between non-age-hardening Al5083 and age hardening Al2024 and compared to single alloy joints made from each of the two constituents. In this paper, we report the results of microstructural, mechanical property investigations of Al5186-Al2024 friction stir welds produced using various rotations and traveling speeds of the tool to investigate the effects of the welding parameters on the joint strength. Metallographic studies by optical microscopy, electron probe microscopy, and the utilization of the X-ray diffraction technique have been conducted. It was found that the weld properties were dominated by the thermal input rather than the mechanical deformation by the tool. In particular the larger stresses under the weld tool on the AA5186 side compared to the AA2024 side are related to a transient reduction in yield stress due to dissolution of the hardening precipitates during welding prior to natural aging after welding.

  20. Effects of powder pretreatment on the microstructure and mechanical properties of tungsten heavy alloys. (Reannouncement with new availability information)

    SciTech Connect (OSTI)

    Bedhadjhamida, A.; German, R.M.

    1991-12-31T23:59:59.000Z

    Tungsten heavy alloys exhibit unique properties such as high strength, density, ductility and toughness. Alloying additions of molybdenum to the W-Ni-Fe system have drastically decreased the sintered grain size through the limited solubility of tungsten in the solid solution matrix in the presence of molybdenum. This contributes to additional strengthening but a decrease in the ductility. Recent work has shown that the distribution of molybdenum in the tungsten grains is not uniform after sintering. Homogenous coating of Mo on W is desirable to further decrease solution-reprecipitation during liquid phase sintering. In this work, alloying additions of molybdenum in the W-Ni-Fe system through various methods such as electroless-plating, milling, and mixing of elemental powders are investigated. The effects of these techniques on the final microstructure, densification and mechanical properties are examined using electron microscopy, microprobe analysis, and mechanical testing. The ideal distribution of molybdenum in the microstructure is investigated and the optimum alloying addition technique is singled out. This helps to better understand the processes occurring during liquid phase sintering of these alloys and further improve their mechanical properties.

  1. CHAPTER 5: CONCLUSIONS AND FUTURE WORK Theoretical predictions of the mechanical properties of carbon nanotubes, and

    E-Print Network [OSTI]

    Fisher, Frank

    of multifunctional composite materials with controllable electrical and thermal properties, in addition to order to these material systems within the last few years. Initial experimental work on carbon nanotube properties of carbon nanotubes, and in particular their predicted high strengths (on the order of 60 GPa

  2. Data collection on the effect of irradiation on the mechanical properties of austenitic stainless steels and weld metals

    SciTech Connect (OSTI)

    Tavassoli, A.A. [Commissariat a l`Energie Atomique, Gif sur Yvette (France); Picker, C.; Wareing, J. [AEA Technology, Risley (United Kingdom)

    1996-12-31T23:59:59.000Z

    Data on the influence of low dose 400--550 C irradiation on the mechanical properties of structural steels (Types 304, 316, 316L, 316H and 316L(N) and associated weld metals) at temperatures from 20 C to 750 C, have been compiled from published literature and the results of British, Dutch, French and German laboratories. Properties evaluated include tensile, impact, creep, fatigue, and creep-fatigue. The preliminary results, which cover the dose range from 0 to 5 displacements per atom (and/or up to 9 appm helium) are presented as comparisons between irradiated and unirradiated control data, covering a range of strength and cyclic properties. The results show that low dose irradiation can have a significant influence on the properties, i.e.: (1) increases in tensile proof strength; (2) reductions in tensile ductility; (3) decreases in impact energy; (4) reductions in creep-rupture strength and ductility; and (5) reductions in creep-fatigue endurance. By considering the influence of irradiation temperature and dose level, the results are rationalized in terms of irradiation hardening and grain boundary embrittlement mechanisms.

  3. The effect of inhibitors on material and mechanical properties of oxidized carbon-carbon composites

    E-Print Network [OSTI]

    Elliott, Charles Howard

    1995-01-01T23:59:59.000Z

    approach examines the importance of fatigue crack formation due to expansion and contraction. Mass loss and material property degradation is assessed with subsequent exploratory nondestructive testing of rheometry and piezoelectric ultrasonic composite...

  4. MICROSTRUCTURE AND MECHANICAL PROPERTIES OF 0.1C STEEL WITH Nb

    E-Print Network [OSTI]

    Gau, Jing-Sheng

    2014-01-01T23:59:59.000Z

    and Properties of Dual-Phase Steels, R. A. Kot and J. W.and Prooerties of Dual-Phase Steels, R. A. Kot and J. W.Prooerties of Vanadium Dual Phase Steel and Cold Pressing

  5. Longitudinal ultrasound measurement of the equine third metacarpal bone as a predictor of mechanical testing properties 

    E-Print Network [OSTI]

    Dyer, Stephanie Ann

    1999-01-01T23:59:59.000Z

    diagnostic technique to identify the onset of bucked shins. The purpose of this study was to determine if the longitudinal speed of sound as measured by Soundscan 2000[] was an appropriate predictor of bone strength characterized by mechanical testing...

  6. Mechanical Properties and Radiation Tolerance of Ultrafine Grained and Nanocrystalline Metals

    E-Print Network [OSTI]

    Sun, Cheng

    2013-04-26T23:59:59.000Z

    loops. Here we provide experimental evidence that high angle grain boundaries can effectively remove radiation-induced defects. The equal channel angular pressing (ECAP) technique was used to produce ultrafine grained Fe-Cr-Ni alloy. Mechanical...

  7. Natural rubber-clay nanocomposites: mechanical and structural properties Camila A. Rezende1,2

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , University of Campinas, P.O. Box 6154, CEP 13083-970, Campinas- SP, Brazil *Corresponding Author E-mail: Lay in the number of papers and patents on polymer-clay nanocomposites that report outstanding mechanical

  8. Application of quantum theory of electrons to the mechanical and thermal properties of metals 

    E-Print Network [OSTI]

    Peng, Hwan-Wu

    The first successful application of quantum mechanics to the problem of metallic cohesion was made by Wigner and Seitz (1938) They appoximated sodium metal by a number of isolated spheres of equal atomic volume and integrated, ...

  9. Characterization of the effects of x-ray irradiation on the hierarchical structure and mechanical properties of human cortical bone

    SciTech Connect (OSTI)

    Barth, Holly; Zimmermann, Elizabeth; Schaible, Eric; Tang, Simon; Alliston, Tamara; Ritchie, Robert

    2011-08-19T23:59:59.000Z

    Bone comprises a complex structure of primarily collagen, hydroxyapatite and water, where each hierarchical structural level contributes to its strength, ductility and toughness. These properties, however, are degraded by irradiation, arising from medical therapy or bone-allograft sterilization. We provide here a mechanistic framework for how irradiation affects the nature and properties of human cortical bone over a range of characteristic (nano to macro) length-scales, following x-­ray exposures up to 630 kGy. Macroscopically, bone strength, ductility and fracture resistance are seen to be progressively degraded with increasing irradiation levels. At the micron-­scale, fracture properties, evaluated using in-situ scanning electron microscopy and synchrotron x-ray computed micro-tomography, provide mechanistic information on how cracks interact with the bone-matrix structure. At sub-micron scales, strength properties are evaluated with in-situ tensile tests in the synchrotron using small-/wide-angle x-ray scattering/diffraction, where strains are simultaneously measured in the macroscopic tissue, collagen fibrils and mineral. Compared to healthy bone, results show that the fibrillar strain is decreased by ~40% following 70 kGy exposures, consistent with significant stiffening and degradation of the collagen. We attribute the irradiation-­induced deterioration in mechanical properties to mechanisms at multiple length-scales, including changes in crack paths at micron-­scales, loss of plasticity from suppressed fibrillar sliding at sub-­micron scales, and the loss and damage of collagen at the nano-­scales, the latter being assessed using Raman and Fourier-Transform-Infrared spectroscopy and a fluorometric assay.

  10. The Prediction and Simulation for the Mechanical Properties of Ceramic-Based Composites Reinforced with Nano-Micro Particles

    SciTech Connect (OSTI)

    Luo Dongmei; Hu Jinshan; Yang Hong [Environment and Civil Engineering School, Foshan University, Foshan, 528000 (China); Zhou Yinglong [Department of Mechatronics Engineering, Foshan University, Foshan 528000 (China)

    2010-05-21T23:59:59.000Z

    The global-local homogenization method with precise period boundary conditions is applied to predict and simulate the mechanical properties of ceramic composites reinforced by spherical nano-micro particles with enwrapping and nesting arrays. The numerical simulation is performed with different size ratios of nano-micro particles, and different configurations for representative volume element. The results show that the low radius ratios of nano-micro particles produce a larger effective Young's modulus for its more uniform dispersion, and the hexagon RVE with nesting array can make an overestimation for effective elastic modulus of ceramic composites, and the interfacial damage between nano-microscopic particles and matrix degenerates the effective elastic modulus. It shows in this paper that it is significant to improve the mechanical properties of ceramic materials by mixing some nano- and micro-particles into the matrix with good designed array methods from the viewpoints of nano-microscopic crystal structure, and a rational interfacial damage model should be further proposed to investigate the toughening mechanism of ceramic-composites reinforced with nano-micro particles.

  11. Method for predicting dry mechanical properties from wet wood and standing trees

    DOE Patents [OSTI]

    Meglen, Robert R.; Kelley, Stephen S.

    2003-08-12T23:59:59.000Z

    A method for determining the dry mechanical strength for a green wood comprising: illuminating a surface of the wood to be determined with light between 350-2,500 nm, the wood having a green moisture content; analyzing the surface using a spectrometric method, the method generating a first spectral data, and using a multivariate analysis to predict the dry mechanical strength of green wood when dry by comparing the first spectral data with a calibration model, the calibration model comprising a second spectrometric method of spectral data obtained from a reference wood having a green moisture content, the second spectral data correlated with a known mechanical strength analytical result obtained from a reference wood when dried and having a dry moisture content.

  12. Modification of anisotropic mechanical properties in recrystallized oxide dispersion strengthened ferritic alloy

    E-Print Network [OSTI]

    Hong, Soon Hyung

    . Introduction Oxide dispersion strengthened (ODS) ferritic/martens- itic steels have been investigated for high materials for the next generation of nuclear power plants [4­6]. The development of ODS ferritic properties of extruded and recrystallized Fe­20%Cr ferritic ODS alloys have been characterized. Then

  13. Evaluation of the interfacial mechanical properties in fiber-reinforced ceramic composites

    SciTech Connect (OSTI)

    Ferber, M.K.; Wereszczak, A.A.; Riester, L.; Lowden, R.A. [Oak Ridge National Lab., TN (United States); Chawla, K.K. [New Mexico Inst. of Mining and Technology, Socorro, NM (United States)

    1993-06-01T23:59:59.000Z

    The present study examined the application of a micro-indentation technique to the measurement of interfacial properties in fiber reinforced ceramic composites. Specific fiber/matrix systems included SiC/glass, SiC/macro-defect-free (MDF) cement, SiC/SiC, and mullite/glass. The effect of fiber coatings upon the interfacial properties was also investigated. These properties, which included the debond strength, interfacial shear stress, and residual axial fiber stress, were evaluated by measuring the force-displacement curves generated during load-unload cycles. Estimates of these three stress values were obtained by matching the experimental force-displacement curves with data predicted from an existing model. In general the SiC/glass composites exhibited the lowest values of the interfacial shear and debond stresses. The sliding characteristics of the SiC/MDF cement and SiC/SiC composites were strongly influenced by the residual axial stress and the nature of the fiber coating. In the case of the mullite/glass composite, the high values of the interfacial shear and debond stresses reduced the measurement sensitivity, thereby increasing the uncertainty in the estimates of the interfacial properties. 17 refs, 6 figs, 1 tab.

  14. Microstructure and mechanical properties of WWER-440 reactor vessel metal after service life expiration and recovery anneal

    SciTech Connect (OSTI)

    Gorynin, I.V.; Nesterova, E.V.; Nikolaev, V.A.; Rybin, V.V. [Central Research Inst. of Structural Materials Prometey, St. Petersburg (Russian Federation)

    1996-12-31T23:59:59.000Z

    The microstructure of base and weld metals (st. 15kH2MFA) of Novovoronezh Nuclear Power Plant Units 1 and 4 reactor vessels was studied after service life expiration and recovery anneal by means of light metallography and transmission electron microscopy. The qualitative characteristics of flow structure were determined. The estimates were made for the contributions of different flows to the radiation hardening and its total value. The conclusion was made that the marked difference in the mechanical properties of irradiated weld and base metals can be caused either by different original structure conditions or by the difference of alloying and impurity elements content.

  15. The effect of equal channel angular extrusion on the microstructure and mechanical properties of AISI 1552, AISI 4340, and A2 tool steels 

    E-Print Network [OSTI]

    Shadat, Mohammed Anower

    1998-01-01T23:59:59.000Z

    In this investigation, Austenitized AISI 4340 and A2 tool steel were ausformed using ECAE as a sole deformation mechanism. In addition, AISI 1552 steel was deformed by ECAE. The effect of deformation on hardness, tensile properties...

  16. An investigation of the mechanical and physical properties of copper-silver alloys and the use of these alloys in Pre-Columbian America

    E-Print Network [OSTI]

    Taylor, Shannon L., S.B. Massachusetts Institute of Technology

    2013-01-01T23:59:59.000Z

    In both the Andean zone of South America and in Mesoamerica, copper-silver alloys were important in the production of thin, silver-colored sheet metal artifacts. This thesis examines the mechanical and physical properties ...

  17. Mechanical Properties of Bovine Rhodopsin and Bacteriorhodopsin: Possible Roles in Folding and Function

    E-Print Network [OSTI]

    Palczewski, Krzysztof

    in rhodopsin but not in bacteriorhodopsin. This core may reflect differences in mechanisms of protein folding their adaptation to differing functions. Introduction Protein folding is one of the most challenging problems protein folding. For more than a decade, the atomic force microscope (AFM) has permitted the use of single

  18. Mechanical properties of connected carbon nanorings via molecular dynamics simulation Nan Chen and Mark T. Lusk*

    E-Print Network [OSTI]

    Barr, Al

    be constructed from nanotubes. In theory, such rings could be used to fabricate networks that are extremely conditions that idealize the constraints of nanochains and nanomaile. The results indicate nanorings investigated as possible lubricants,13 and carbon nanohooks can be used to make nanovelcro.14 Unique mechanical

  19. Connection between the neutrino seesaw mechanism and properties of the Majorana neutrino mass matrix

    SciTech Connect (OSTI)

    Ma, Ernest [Physics Department, University of California, Riverside, California 92521 (United States)

    2005-06-01T23:59:59.000Z

    If it can be ascertained experimentally that the 3x3 Majorana neutrino mass matrix M{sub {nu}} has vanishing determinants for one or more of its 2x2 submatrices, it may be interpreted as supporting evidence for the theoretically well-known canonical seesaw mechanism. I show how these two things are connected and offer a realistic M{sub {nu}} with two zero subdeterminants as an example.

  20. Mechanical properties and microstructural characterization of SiC-fiber-reinforced cordieritic glass-ceramics

    SciTech Connect (OSTI)

    Chaim, R.; Brandon, D.G.; Baum, L.

    1988-08-01T23:59:59.000Z

    Cordieritic glass-ceramic matrix composites were prepared using Nicalon SiC continuous-fiber reinforcement. Both one- and two-dimensional laminates were investigated. Damage-tolerant behavior was observed in several of the experimental compositions and was associated with fiber-pullout and crack-deflection toughening mechanisms. The complex microstructure of the matrix phase is amenable to heat treatment. The fiber microstructure is apparently unaffected by heat treatment after hot pressing. The structure of the fiber/matrix interface is also complex and sensitive to both the matrix composition and to heat treatment after hot pressing. 10 references.

  1. Composition suitable for use as inert electrode having good electrical conductivity and mechanical properties

    DOE Patents [OSTI]

    Ray, Siba P. (Plum Boro, PA); Rapp, Robert A. (Columbus, OH)

    1984-01-01T23:59:59.000Z

    An improved inert electrode composition is suitable for use as an inert electrode in the production of metals such as aluminum by the electrolytic reduction of metal oxide or metal salt dissolved in a molten salt bath. The composition comprises one or more metals or metal alloys and metal compounds which may include oxides of the metals comprising the alloy. The alloy and metal compounds are interwoven in a network which provides improved electrical conductivity and mechanical strength while preserving the level of chemical inertness necessary for such an electrode to function satisfactorily.

  2. Composition suitable for use as inert electrode having good electrical conductivity and mechanical properties

    DOE Patents [OSTI]

    Ray, S.P.; Rapp, R.A.

    1984-06-12T23:59:59.000Z

    An improved inert electrode composition is suitable for use as an inert electrode in the production of metals such as aluminum by the electrolytic reduction of metal oxide or metal salt dissolved in a molten salt bath. The composition comprises one or more metals or metal alloys and metal compounds which may include oxides of the metals comprising the alloy. The alloy and metal compounds are interwoven in a network which provides improved electrical conductivity and mechanical strength while preserving the level of chemical inertness necessary for such an electrode to function satisfactorily. 8 figs.

  3. Injection-Molded Long-Fiber Thermoplastic Composites: From Process Modeling to Prediction of Mechanical Properties

    SciTech Connect (OSTI)

    Nguyen, Ba Nghiep; Kunc, Vlastimil; Jin, Xiaoshi; Tucker III, Charles L.; Costa, Franco

    2013-12-18T23:59:59.000Z

    This article illustrates the predictive capabilities for long-fiber thermoplastic (LFT) composites that first simulate the injection molding of LFT structures by Autodesk® Simulation Moldflow® Insight (ASMI) to accurately predict fiber orientation and length distributions in these structures. After validating fiber orientation and length predictions against the experimental data, the predicted results are used by ASMI to compute distributions of elastic properties in the molded structures. In addition, local stress-strain responses and damage accumulation under tensile loading are predicted by an elastic-plastic damage model of EMTA-NLA, a nonlinear analysis tool implemented in ABAQUS® via user-subroutines using an incremental Eshelby-Mori-Tanaka approach. Predicted stress-strain responses up to failure and damage accumulations are compared to the experimental results to validate the model.

  4. Comparison of quasistatic to impact mechanical properties of multiwall carbon nanotube/polycarbonate composites

    SciTech Connect (OSTI)

    Brühwiler, Paul A.; Barbezat, Michel; Necola, Adly; Kohls, Doug J.; Bunk, Oliver; Schaefer, Dale W.; Pötschke, Petra (PSI); (EMMPA); (UCIN); (Leibniz)

    2010-10-22T23:59:59.000Z

    We report the quasistatic tensile and impact penetration properties (falling dart test) of injection-molded polycarbonate samples, as a function of multiwall carbon nanotube (MWNT) concentration (0.0-2.5%). The MWNT were incorporated by dilution of a commercial MWNT/polycarbonate masterbatch. The stiffness and quasistatic yield strength of the composites increased approximately linearly with MWNT concentration in all measurements. The energy absorbed in fracture was, however, a negative function of the MWNT concentration, and exhibited different dependencies in quasistatic and impact tests. Small-angle x-ray scattering (SAXS) showed that the dispersion of the MWNT was similar at all concentrations. The negative effects on energy absorption are attributed to agglomerates remaining in the samples, which were observed in optical microscopy and SAXS. Overall, there was a good correspondence between static and dynamic energy absorption.

  5. Apparatus and method for measurement of the mechanical properties and electromigration of thin films

    DOE Patents [OSTI]

    Maris, Humphrey J. (Barrington, RI)

    2000-01-01T23:59:59.000Z

    A method for characterizing a sample comprising the steps of depositing the sample on a substrate, measuring a first change in optical response of the sample, changing the lateral strain of the sample, measuring a second change in optical response of the sample, comparing the second change in optical response of with the first change in optical response and associating a difference between the second change and the first change in optical response with a property of interest in the sample. The measurement of the first change in optical response is made with the sample having an initial lateral strain. The measurement of the second change in optical response is made after the lateral strain in the sample is changed from the initial lateral strain to a different lateral strain. The second change in optical response is compared to the first change in optical response to find the difference between the second change and the first change.

  6. Apparatus and method for measurement of the mechanical properties and electromigration of thin films

    DOE Patents [OSTI]

    Maris, Humphrey J. (Barrington, RI)

    2001-01-01T23:59:59.000Z

    A method for characterizing a sample comprising the steps of depositing the sample on a substrate, measuring a first change in optical response of the sample, changing the lateral strain of the sample, measuring a second change in optical response of the sample, comparing the second change in optical response of with the first change in optical response and associating a difference between the second change and the first change in optical response with a property of interest in the sample. The measurement of the first change in optical response is made with the sample having an initial lateral strain. The measurement of the second change in optical response is made after the lateral strain in the sample is changed from the initial lateral strain to a different lateral strain. The second change in optical response is compared to the first change in optical response to find the difference between the second change and the first change.

  7. Synthesis, formation mechanism and sensing properties of WO{sub 3} hydrate nanowire netted-spheres

    SciTech Connect (OSTI)

    Yan, Aihua [State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)] [State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Xie, Changsheng, E-mail: csxie@mail.hust.edu.cn [State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China) [State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Nanomaterial and Smart Sensor Research Laboratory, Department of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); Zeng, Dawen [State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)] [State Key Laboratory of Material Processing and Die and Mould Technology, Huazhong University of Science and Technology, Wuhan 430074 (China); Cai, Shuizhou; Hu, Mulin [Nanomaterial and Smart Sensor Research Laboratory, Department of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)] [Nanomaterial and Smart Sensor Research Laboratory, Department of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China)

    2010-10-15T23:59:59.000Z

    Tungsten oxide hydrate nanowire netted-spheres were successfully synthesized in the glycol solution using a facile solvothermal approach. The nanowires with uniform diameter of 4-6 nm are actually a kind of tungsten oxide hydrate/surfactant hybrid materials. The influence of surfactant, solvent, time and temperature on tailoring morphology was investigated in detail. The possible formation process of WO{sub 3} hydrate nanowire netted-sphere was proposed. Sensing properties of such WO{sub 3} hydrate sensor show that the desirable sensing characteristics towards 100 ppm ammonia gas at 320 {sup o}C were obtained, such as rapid response (18.3 s), high sensitivity, good reproducibility and stability.

  8. Effect of mechanical boundary conditions on the dynamic and static properties of a strongly anisotropic ferromagnet

    SciTech Connect (OSTI)

    Gorelikov, G. A.; Fridman, Yu. A., E-mail: frid@crimea.edu [Vernadskii Tavria National University (Ukraine)

    2013-07-15T23:59:59.000Z

    The spectra of coupled magnetoelastic waves in a semi-infinite strongly anisotropic easy-plane ferromagnet with a rigidly fixed face are analyzed for two variants of fixation (in the basal plane and perpendicularly to it). The phase states of the system are determined. Differences in the phase diagrams and elementary excitation spectra depending on the choice of the sample fixation plane are considered. When rotational invariance is taken into account, the nonreciprocity effect for the velocities of sound in a crystal appears. It is shown that the velocity of sound in the sample considerably depends on the symmetry of the imposed mechanical boundary conditions. The phase diagrams of the system under investigation are presented.

  9. Effects of coal slag corrosion on the mechanical properties of sintered {alpha}-silicon carbide

    SciTech Connect (OSTI)

    Hannel, S.E. [Ecole Centrale, Lyon (France); Breder, K.; Joslin, D.L. [Oak Ridge National Lab., TN (United States)

    1997-03-01T23:59:59.000Z

    Tubes of sintered SiC were exposed for 500 h in a laboratory furnace to three different coal slags at three temperatures. No corrosive attack or strength reduction was observed after exposure at 1090{degrees}C. At 1260{degrees}C the least viscous slag caused formation of corrosion pits and loss of strength. At 1430{degrees}C formation of iron silicides at the interface between the slag and the base material caused severe loss of strength for slags with the highest and the lowest viscosity, while the specimens exposed to the slag with medium viscosity and medium iron content survived quite well. The results show that mechanical strength can be retained for certain coal slag - temperature combinations.

  10. Effect of CNTs dispersion on the thermal and mechanical properties of Cu/CNTs nanocomposites

    SciTech Connect (OSTI)

    Muhsan, Ali Samer, E-mail: alisameer2007@gmail.com, E-mail: faizahmad@petronas.com.my; Ahmad, Faiz, E-mail: alisameer2007@gmail.com, E-mail: faizahmad@petronas.com.my; Yusoff, Puteri Sri Melor Megat Bt, E-mail: puteris@petronas.com.my [Department of Mechanical Engineering, Universiti Teknologi PETRONAS (UTP) (Malaysia); Mohamed, Norani M., E-mail: noranimuti-mohamed@petronas.com.my [Centre of Innovative Nanostructures and Nanodevices (COINN), UTP (Malaysia); Raza, M. Rafi, E-mail: rafirazamalik@gmail.com [Universiti Kebangsaan Malaysia, 43600, Bangi, Selangor (Malaysia)

    2014-10-24T23:59:59.000Z

    Modified technique of metal injection molding (MIM) was used to fabricate multiwalled carbon nanotube (CNT) reinforced Cu nanocomposites. The effect of adding different amount of CNTs (0-10 vol.%) on the thermal and mechanical behaviour of the fabricated nanocomposites is presented. Scanning electron microscope analysis revealed homogenous dispersion of CNTs in Cu matrices at different CNTs contents. The experimentally measured thermal conductivities of Cu/CNTs nanocomposites showed extraordinary increase (76% higher than pure sintered Cu) with addition of 10 vol.% CNTs. As compared to the pure sintered Cu, increase in modulus of elasticity (Young's modulus) of Cu/CNTs nanocomposites sintered at 1050°C for 2.5 h was measured to be 48%. However, in case of 7.5 vol.% CNTs, Young's modulus was increased significantly about 51% compared to that of pure sintered Cu.

  11. Effects of in situ fiber strength characteristics on mechanical properties of SiC(f)/SiC composites

    SciTech Connect (OSTI)

    Singh, D.; Singh, J.P.; Wheeler, M.J.

    1994-06-01T23:59:59.000Z

    Nicalon-fiber-reinforced silicon carbide (SiC) matrix composites were tested in flexure at room and elevated temperatures. The measured strength of composites decreased slightly from a room temperature value of 400 MPa to 380 MPa at 1200{degrees}C. However, at 1300{degrees}C strength decreased significantly to 290 Mpa. The rapid decrease in strength over 1300{degrees}C is believed to be due to degradation in strength of the reinforcing fibers. In situ fiber strength and fiber pullout distribution in fractured composites were estimated by fractographic techniques. Correlations were made between the measured strengths of composites to the in situ fiber strength characteristics to explain the mechanical properties of composites at room and elevated temperatures.

  12. Electrical transport and mechanical properties of alkylsilane self-assembled monolayers on silicon surfaces probed by atomic force microscopy

    SciTech Connect (OSTI)

    Park, Jeong Young; Qi, Yabing; Ashby, Paul D.; Hendriksen, Bas L.M.; Salmeron, Miquel

    2009-02-06T23:59:59.000Z

    The correlation between molecular conductivity and mechanical properties (molecular deformation and frictional responses) of hexadecylsilane self-assembled monolayers was studied with conductive probe atomic force microscopy/friction force microscopy in ultrahigh vacuum. Current and friction were measured as a function of applied pressure, simultaneously, while imaging the topography of self-assembled monolayer molecule islands and silicon surfaces covered with a thin oxide layer. Friction images reveal lower friction over the molecules forming islands than over the bare silicon surface, indicating the lubricating functionality of alkylsilane molecules. By measuring the tunneling current change due to changing of the height of the molecular islands by tilting the molecules under pressure from the tip, we obtained an effective conductance decay constant ({beta}) of 0.52/{angstrom}.

  13. Mechanical and charge transport properties of alkanethiol self-assembled monolayers on Au (111) surface: The Role of Molecular Tilt

    SciTech Connect (OSTI)

    Mulleregan, Alice; Qi, Yabing; Ratera, Imma; Park, Jeong Y.; Ashby, Paul D.; Quek, Su Ying; Neaton, J. B.; Salmeron, Miquel

    2007-11-12T23:59:59.000Z

    The relationship between charge transport and mechanical properties of alkanethiol self-assembled monolayers (SAM) on Au(111) films has been investigated using an atomic force microscope with a conductive tip. Molecular tilts induced by the pressure applied by the tip cause stepwise increases in film conductivity. A decay constant {beta} = 0.57 {+-} 0.03 {angstrom}{sup -1} was found for the current passing through the film as a function of tip-substrate separation due to this molecular tilt. This is significantly smaller than the value of {approx} 1 {angstrom}{sup -1} found when the separation is changed by changing the length of the alkanethiol molecules. Calculations indicate that for isolated dithiol molecules S-bonded to hollow sites, the junction conductance does not vary significantly as a function of molecular tilt. The impact of S-Au bonding on SAM conductance is discussed.

  14. The effect of fusion-relevant helium levels on the mechanical properties of isotopically tailored ferritic alloys

    SciTech Connect (OSTI)

    Hankin, G.L. [Loughborough Univ. (United Kingdom); Hamilton, M.L.; Gelles, D.S. [Pacific Northwest National Lab., Richland, WA (United States)] [and others

    1997-04-01T23:59:59.000Z

    The yield and maximum strengths of an irradiated series of isotopically tailored ferritic alloys were evaluated using the shear punch test. The composition of three of the alloys was Fe-12Cr-1.5Ni. Different balances of nickel isotopes were used in each alloy in order to produce different helium levels. A fourth alloy, which contained no nickel, was also irradiated. The addition of nickel at any isotopic balance to the Fe-12Cr base alloy significantly increased the shear yield and maximum strengths of the alloys, and as expected, the strength of the alloys decreased with increasing irradiation temperature. Helium itself, up to 75 appm over 7 dpa appears to have little effect on the mechanical properties of the alloys.

  15. Effect of heat treatment on the mechanical properties of modified 9Cr-1Mo steel

    SciTech Connect (OSTI)

    Sultan F. Alsagabi; Triratna Shrestha; Indrajit Charit; Gabriel P. Potirniche; Michael V. Glazoff

    2014-09-01T23:59:59.000Z

    The modified 9Cr-1Mo steel (Grade 91) is a material of choice in fossil-fuel-fired power plants with increased efficiency, service life, and reduction in emission of greenhouse gases. It is also considered a prospective material for the Next Generation Nuclear Power Plant for application in reactor pressure vessels at temperatures up to 650°C. In this paper, heat treatment of the modified 9Cr-1Mo steel was studied by normalizing and tempering the steel at various temperatures and times, with the ultimate goal of improving its creep resistance and optimizing material hardness. The microstructural evolution of the heat treated steels was correlated with the differential scanning calorimetric results. Optical microscopy, scanning and transmission electron microscopy in conjunction with microhardness profiles and calorimetric plots were used to understand the evolution of microstructure including precipitate structures in modified 9Cr-1Mo steel and relate it to the mechanical behavior of the steel. Thermo- CalcTM calculations were used to support experimental work and provide guidance in terms of the precipitate stability and microstructural evolution. Furthermore, the carbon isopleth and temperature dependencies of the volume fraction of different precipitates were constructed. The predicted and experimentally observed results were found to be in good agreement.

  16. Thermal and mechanical denaturation properties of a DNA model with three sites per nucleotide

    E-Print Network [OSTI]

    Florescu, Ana-Maria; 10.1063/1.3626870

    2011-01-01T23:59:59.000Z

    In this paper, we show that the coarse grain model for DNA, which has been proposed recently by Knotts, Rathore, Schwartz and de Pablo (J. Chem. Phys. 126, 084901 (2007)), can be adapted to describe the thermal and mechanical denaturation of long DNA sequences by adjusting slightly the base pairing contribution. The adjusted model leads to (i) critical temperatures for long homogeneous sequences that are in good agreement with both experimental ones and those obtained from statistical models, (ii) a realistic step-like denaturation behaviour for long inhomogeneous sequences, and (iii) critical forces at ambient temperature of the order of 10 pN, close to measured values. The adjusted model furthermore supports the conclusion that the thermal denaturation of long homogeneous sequences corresponds to a first-order phase transition and yields a critical exponent for the critical force equal to sigma=0.70. This model is both geometrically and energetically realistic, in the sense that the helical structure and th...

  17. Comparative study of the mechanical properties of nanostructured thin films on stretchable substrates

    SciTech Connect (OSTI)

    Djaziri, S. [Max-Planck-Institut für Eisenforschung GmbH, Max-Planck-Straße 1, 40237 Düsseldorf (Germany); Institut P' (UPR 3346 CNRS), Université de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Renault, P.-O.; Le Bourhis, E.; Goudeau, Ph., E-mail: Philippe.goudeau@univ-poitiers.fr [Institut P' (UPR 3346 CNRS), Université de Poitiers, ENSMA, Bd Pierre et Marie Curie, 86962 Futuroscope Cedex (France); Faurie, D. [LSPM, (UPR 3407 CNRS), Université Paris 13, Institut Galilée, 99 avenue Jean-Baptiste Clément, 93430 Villetaneuse (France); Geandier, G. [Institut Jean Lamour (UMR 3079 CNRS), Université de Lorraine, Parc de Saurupt, CS 50840, 54011 NANCY Cedex (France); Mocuta, C.; Thiaudière, D. [Synchrotron SOLEIL, L'Orme des Merisiers, Saint-Aubin, BP 48, 91192 Gif-sur-Yvette Cedex (France)

    2014-09-07T23:59:59.000Z

    Comparative studies of the mechanical behavior between copper, tungsten, and W/Cu nanocomposite based on copper dispersoïd thin films were performed under in-situ controlled tensile equi-biaxial loadings using both synchrotron X-ray diffraction and digital image correlation techniques. The films first deform elastically with the lattice strain equal to the true strain given by digital image correlation measurements. The Cu single thin film intrinsic elastic limit of 0.27% is determined below the apparent elastic limit of W and W/Cu nanocomposite thin films, 0.30% and 0.49%, respectively. This difference is found to be driven by the existence of as-deposited residual stresses. Above the elastic limit on the lattice strain-true strain curves, we discriminate two different behaviors presumably footprints of plasticity and fracture. The Cu thin film shows a large transition domain (0.60% true strain range) to a plateau with a smooth evolution of the curve which is associated to peak broadening. In contrast, W and W/Cu nanocomposite thin films show a less smooth and reduced transition domain (0.30% true strain range) to a plateau with no peak broadening. These observations indicate that copper thin film shows some ductility while tungsten/copper nanocomposites thin films are brittle. Fracture resistance of W/Cu nanocomposite thin film is improved thanks to the high compressive residual stress and the elimination of the metastable ?-W phase.

  18. Critical issues in measuring the mechanical properties of hard films on soft substrates by nanoindentation techniques

    SciTech Connect (OSTI)

    Hay, J.C. [Oak Ridge National Lab., TN (United States); Pharr, G.M. [Rice Univ., Houston, TX (United States). Dept. of Materials Science

    1997-12-31T23:59:59.000Z

    This study explores the difficulties encountered when using conventional nanoindentation techniques to measure the Young`s modulus and hardness of hard films on soft substrates. In general, the indentation measurement of film/substrate systems is affected by four material properties: the Young`s modulus and hardness of the film, and the Young`s modulus and hardness of the substrate. For the particular case of a hard film on a soft substrate, there is a tendency for the material around the hardness impression to sink-in which results from the large difference in yielding of the two materials. In this study, a model system consisting of NiP on annealed Cu was used to explore the behavior. This system is interesting because the film and substrate have similar Young`s moduli, minimizing the elastic behavior as a variable. In contrast, the hardness of NiP is approximately 7--8 GPa, and that of the annealed copper is less than 1 GPa, providing a factor of 10 difference in the plastic flow characteristics. Experimental results indicate that standard analytical methods for determining the contact depth, hardness and Young`s modulus do not work well for the case of a hard film on a soft substrate. At shallow contact depths, the measured indentation modulus is close to that of the film, but at larger depths sink-in phenomena result in an overestimation of the contact area, and an indentation modulus which is less than the Young`s modulus of both the film and substrate. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) provide critical details of the physical processes involved, and illustrate how the standard data analyses overestimate the true contact area.

  19. Effects of rhenium alloying on the microstructures and mechanical properties of directionally solidified NiAl-Mo eutectic alloy

    SciTech Connect (OSTI)

    Misra, A.; Wu, Z.L.; Gibala, R. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Materials Science and Engineering

    1997-12-31T23:59:59.000Z

    Low ductility of the reinforcing bcc metal phase at room temperature and weak interfaces can limit the intrinsic toughness and ductility of NiAl-bcc metal eutectic composites. The potential of rhenium (Re) addition, which is known to solid solution soften and lower the ductile-to-brittle transition temperature of various bcc metals, to enhance the ductility and toughness of a directionally solidified NiAl-9 at.% Mo eutectic alloy was investigated. Re partitioned to the bcc metal phase and formed a substitutional solid solution. The interface morphology was changed from a faceted to a non-faceted one. Re alloying caused softening of the Mo fibers, and as a result NiAl-Mo(Re) alloys were softer in compression and flexure and had {approximately}20% higher fracture toughness values as compared to the transverse orientation toughness of NiAl-9Mo alloy. The toughness of the NiAl-Mo(Re) alloys was lower than the longitudinal orientation toughness of the NiAl-9Mo alloy due to the poor alignment of the Mo(Re) phase with the growth direction. The toughening mechanisms have been evaluated and schemes for processing NiAl-Mo(Re) alloys for higher toughness in the longitudinal orientation are suggested. The role of the residual interstitial impurities and partitioning of Ni and Al to Mo fibers on the mechanical properties are highlighted.

  20. Length-scale dependent mechanical properties of Al-Cu eutectic alloy: Molecular dynamics based model and its experimental verification

    SciTech Connect (OSTI)

    Tiwary, C. S., E-mail: cst.iisc@gmail.com; Chattopadhyay, K. [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India); Chakraborty, S.; Mahapatra, D. R. [Department of Aerospace Engineering, Indian Institute of Science, Bangalore 560012 (India)

    2014-05-28T23:59:59.000Z

    This paper attempts to gain an understanding of the effect of lamellar length scale on the mechanical properties of two-phase metal-intermetallic eutectic structure. We first develop a molecular dynamics model for the in-situ grown eutectic interface followed by a model of deformation of Al-Al{sub 2}Cu lamellar eutectic. Leveraging the insights obtained from the simulation on the behaviour of dislocations at different length scales of the eutectic, we present and explain the experimental results on Al-Al{sub 2}Cu eutectic with various different lamellar spacing. The physics behind the mechanism is further quantified with help of atomic level energy model for different length scale as well as different strain. An atomic level energy partitioning of the lamellae and the interface regions reveals that the energy of the lamellae core are accumulated more due to dislocations irrespective of the length-scale. Whereas the energy of the interface is accumulated more due to dislocations when the length-scale is smaller, but the trend is reversed when the length-scale is large beyond a critical size of about 80?nm.

  1. Facile synthesis, spectral properties and formation mechanism of sulfur nanorods in PEG-200

    SciTech Connect (OSTI)

    Xie, Xin-yuan; Li, Li-yun; Zheng, Pu-sheng [Department of Chemistry, Jinan University, Guangzhou 510632 (China)] [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Zheng, Wen-jie, E-mail: tzhwj@jnu.edu.cn [Department of Chemistry, Jinan University, Guangzhou 510632 (China)] [Department of Chemistry, Jinan University, Guangzhou 510632 (China); Bai, Yan; Cheng, Tian-feng; Liu, Jie [Department of Chemistry, Jinan University, Guangzhou 510632 (China)] [Department of Chemistry, Jinan University, Guangzhou 510632 (China)

    2012-11-15T23:59:59.000Z

    Graphical abstract: Homogeneous rod-like structure of sulfur with a typical diameter of about 80 nm and an average aspect ratio of about 6–8 was obtained. The sulfur nanoparticles could self-assemble from spherical particles to nanorods in PEG-200. During the self-assembling process, the absorption band showed a red shift which was due to the production of nanorods. Highlights: ? A novel, facile and greener method to synthesize sulfur nanorods by the solubilizing and templating effect of PEG-200 was reported. ? S{sup 0} nanoparticles could self assemble in PEG-200 and finally form monodisperse and homogeneous rod-like structure with an average diameter of about 80 nm, the length ca. 600 nm. ? The absorption band showed a red shift and the RRS intensity enhanced continuously during the self-assembling process. ? PEG-200 induced the oriented attachment of sulfur nanoparticles by the terminal hydroxyl groups. -- Abstract: The synthesis of nano-sulfur sol by dissolving sublimed sulfur in a green solvent-PEG-200 was studied. Homogeneous rod-like structure of sulfur with a typical diameter of about 80 nm and an average aspect ratio of 6–8 was obtained. The structure, morphology, size, and stability of the products were investigated by transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR) and dynamic light scattering (DLS) measurements. The spectral properties of the products were investigated by ultraviolet-visible (UV–vis) absorption and resonance Rayleigh scattering spectroscopy (RRS). The results showed that the spherical sulfur nanoparticles could self-assemble into nanorods in PEG-200. During the self-assembling process, the absorption band showed a red shift and the RRS intensity enhanced continuously. There was physical cross-linking between PEG and sulfur nanoparticles. PEG-200 induced the oriented attachment of sulfur nanoparticles by the terminal hydroxyl groups. This research provides a greener and more environment-friendly synthetic method for the production of sulfur nanorods.

  2. Effects of filament-matrix interfaces on the mechanical properties of SiC-reinforced Si sub 3 N sub 4: A Review

    SciTech Connect (OSTI)

    Schilling, C.H.

    1989-09-01T23:59:59.000Z

    This report summarizes the results of a literature review of the effects of filament-matrix interfaces on the mechanical properties of ceramic composites composed of SiC-filament-reinforced Si{sub 3}N{sub 4}. A general review of the processing and mechanical properties of SiC-filament-reinforced Si{sub 3}N{sub 4} is presented with special emphasis on research pertaining to processing-related effects on filament-matrix interfaces and the resulting effects of these interfaces on fracture behavior. A review of coating techniques for ceramic filaments is also presented, and recommendations are made for future directions in processing SiC-filament-reinforced Si{sub 3}N{sub 4} with mechanical properties that are enhanced by the microstructure of the filament-matrix interface. 148 refs., 1 tab.

  3. ACOUSTICAL IMAGING AND MECHANICAL PROPERTIES OF SOFT ROCK AND MARINE SEDIMENTS

    SciTech Connect (OSTI)

    Thurman E. Scott, Jr., Ph.D.; Younane Abousleiman, Ph.D.; Musharraf Zaman, Ph.D., P.E.

    2002-11-18T23:59:59.000Z

    During the sixth quarter of this research project the research team developed a method and the experimental procedures for acquiring the data needed for ultrasonic tomography of rock core samples under triaxial stress conditions as outlined in Task 10. Traditional triaxial compression experiments, where compressional and shear wave velocities are measured, provide little or no information about the internal spatial distribution of mechanical damage within the sample. The velocities measured between platen-to-platen or sensor-to-sensor reflects an averaging of all the velocities occurring along that particular raypath across the boundaries of the rock. The research team is attempting to develop and refine a laboratory equivalent of seismic tomography for use on rock samples deformed under triaxial stress conditions. Seismic tomography, utilized for example in crosswell tomography, allows an imaging of the velocities within a discrete zone within the rock. Ultrasonic or acoustic tomography is essentially the extension of that field technology applied to rock samples deforming in the laboratory at high pressures. This report outlines the technical steps and procedures for developing this technology for use on weak, soft chalk samples. Laboratory tests indicate that the chalk samples exhibit major changes in compressional and shear wave velocities during compaction. Since chalk is the rock type responsible for the severe subsidence and compaction in the North Sea it was selected for the first efforts at tomographic imaging of soft rocks. Field evidence from the North Sea suggests that compaction, which has resulted in over 30 feet of subsidence to date, is heterogeneously distributed within the reservoir. The research team will attempt to image this very process in chalk samples. The initial tomographic studies (Scott et al., 1994a,b; 1998) were accomplished on well cemented, competent rocks such as Berea sandstone. The extension of the technology to weaker samples is more difficult but potentially much more rewarding. The chalk, since it is a weak material, also attenuates wave propagation more than other rock types. Three different types of sensors were considered (and tested) for the tomographic imaging project: 600 KHz PZT, 1 MHz PZT, and PVDF film sensors. 600 KHz PZT crystals were selected because they generated a sufficiently high amplitude pulse to propagate across the damaged chalk. A number of different configurations were considered for placement of the acoustic arrays. It was decided after preliminary testing that the most optimum arrangement of the acoustic sensors was to place three arrays of sensors, with each array containing twenty sensors, around the sample. There would be two horizontal arrays to tomographically image two circular cross-sectional planes through the rock core sample. A third array would be vertically oriented to provide a vertical cross-sectional view of the sample. A total of 260 acoustic raypaths would be shot and acquired in the horizontal acoustic array to create each horizontal tomographic image. The sensors can be used as both acoustic sources or as acoustic each of the 10 pulsers to the 10 receivers.

  4. Evaluation of thermal stresses in planar solid oxide fuel cells as a function of thermo-mechanical properties of component materials

    E-Print Network [OSTI]

    Manisha,

    2008-10-10T23:59:59.000Z

    EVALUATION OF THERMAL STRESSES IN PLANAR SOLID OXIDE FUEL CELLS AS A FUNCTION OF THERMO-MECHANICAL PROPERTIES OF COMPONENT MATERIALS A Thesis by MANISHA Submitted to the Office of Graduate Studies of Texas A&M University... in partial fulfillment of the requirements for the degree of MASTERS OF SCIENCE August 2008 Major Subject: Mechanical Engineering EVALUATION OF THERMAL STRESSES IN PLANAR SOLID OXIDE FUEL CELLS AS A FUNCTION OF THERMO...

  5. Mechanical deformation of neutrophil into pulmonary capillaries induces cytoskeletal remodeling, pseudopod projection and changes in biomechanical properties

    E-Print Network [OSTI]

    Yap, Belinda

    2005-01-01T23:59:59.000Z

    Neutrophils traversing the pulmonary microcirculation are subjected to mechanical stimulation during their deformation into narrow capillaries. To better understand the time- dependant changes caused by this mechanical ...

  6. Influence of fiber lay-up sequence on mechanical properties of SiC(f)/SiC composites

    SciTech Connect (OSTI)

    Singh, D.; Singh, J.P.; Sutaria, M.

    1996-03-01T23:59:59.000Z

    Mechanical properties of Nicalon-fiber-reinforced silicon carbide matrix composites with two different fiber lay-up sequences (0{degree}/40{degree}/60{degree} and 0{degree}/45{degree}) were evaluated at various temperatures ranging from ambient to 1300{degree}C. Composites with 0{degree}/40{degree}/60{degree} fiber lay-up sequence showed a higher average first matrix cracking stress than that of 0{degree}/45{degree} composites. The measured room-temperature ultimate strength of the 0{degree}/40{degree}/60{degree} composites was 300 MPa compared to 180 MPa for the 0{degree}/45{degree} composites. These measured ultimate strengths were correlated to the predictions made with an analytical model and to in-situ fiber strength characteristics. The large difference in room-temperature ultimate strengths between the two sets of composites is attributed to the relative contributions of the off-axis fibers to the load-bearing capacity of each composite. Up to 1200{degree}C, ultimate strength and work-of-fracture in each set of composites increased, but then declined above 1300{degree}C. The decreases were correlated to in-situ Nicalon fiber strength and fiber/matrix interface degradation.

  7. Report No. 1: Effect of carbon migration in Cr-Mo weldments on metallurgical structure and mechanical properties

    SciTech Connect (OSTI)

    Lundin, C.D.; Khan, K.K.; Yang, D. [Univ. of Tennessee, Knoxville, TN (United States). Dept. of Materials Science and Engineering

    1995-12-01T23:59:59.000Z

    The occurrence and behavior of a carbon denuded ``soft`` zone in Cr-Mo weldments was studied to determine its influence on mechanical properties and in-service behavior. Room temperature tensile tests, creep rupture tests and Moire interferometry evaluations were performed in order to characterize the behavior of this unique zone in Cr-Mo weldments. The zone is brought about by chromium level differentials between the weld metal and base metal. Extensive metallography was accomplished using OLM, SEM and STEM techniques. The results show that the occurrence of the carbon denuded ``soft`` zone is due to carbon migration, which is driven by elemental differences (especially in chromium) between the weld metal and base metal. The extent of carbon migration depends on the PWHT schedule. Higher strain accumulation and work hardening and/or a constraint effect has been observed in the ``soft`` zone during room temperature testing. However, the work hardening/constraint effect is minimal at elevated temperatures (in the creep regime), hence the ``soft`` zone is a potential failure location in elevated temperature service.

  8. Experimental and numerical investigations on tailored tempering process of a U-channel component with tailored mechanical properties

    SciTech Connect (OSTI)

    Tang, B. T., E-mail: tbtsh@hotmail.com [Shandong Jianzhu University, Fengming Rd., Jinan, 250101 (China); Bruschi, S.; Ghiotti, A.; Bariani, P. F. [University of Padova, Via Venezia 1, Padova, 35131 (Italy)

    2013-12-16T23:59:59.000Z

    Hot stamping of quenchenable ultra high strength steels currently represents a promising forming technology for the manufacturing of safety and crash relevant parts. For some applications, such as B-pillars and other structural components that may undergo impact loading, it may be desirable to create regions of the part with tailored mechanical properties. In the paper, a laboratory-scale hot stamped U-channel was manufactured by using a segmented die, which was heated by cartridge heaters and cooled by water channels independently. Local hardness values as low as 289 HV can be achieved using a heated die temperature of 400°C while maintaining a hardness level of 490 HV in the fully cooled region. If the die temperature was increased to 450°C, the Vickers hardness of elements in the heated region was 227 HV, with a reduction in hardness of more than 50%. Optical microscopy was used to verify the microstructure of the as-quenched phases with respect to the heated die temperatures. The FE model of the lab-scale process was developed to capture the overall hardness trends that were observed in the experiments.

  9. Mechanical properties and microstructures of a magnesium alloy gas tungsten arc welded with a cadmium chloride flux

    SciTech Connect (OSTI)

    Zhang, Z.D. [State Key Laboratory of Material Surface Modification by Laser, Ion, and Beams, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China); Liu, L.M. [State Key Laboratory of Material Surface Modification by Laser, Ion, and Beams, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)], E-mail: liulm@dlut.edu.cn; Shen, Y.; Wang, L. [State Key Laboratory of Material Surface Modification by Laser, Ion, and Beams, School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024 (China)

    2008-01-15T23:59:59.000Z

    Gas tungsten arc (GTA) welds were prepared on 5-mm thick plates of wrought magnesium AZ31B alloy, using an activated flux. The microstructural characteristics of the weld joint were investigated using optical and scanning microscopy, and the fusion zone microstructure was compared with that of the base metal. The elemental distribution was also investigated by electron probe microanalysis (EPMA). Mechanical properties were determined by standard tensile tests on small-scale specimens. The as-welded fusion zone prepared using a CdCl{sub 2} flux exhibited a larger grain size than that prepared without flux; the microstructure consisted of matrix {alpha}-Mg, eutectic {alpha}-Mg and {beta}-Al{sub 12}Mg{sub 17}. The HAZ was observed to be slightly wider for the weld prepared with a CdCl{sub 2} flux compared to that prepared without flux; thus the tensile strength was lower for the flux-prepared weld. The fact that neither Cd nor Cl was detected in the weld seam by EPMA indicates that the CdCl{sub 2} flux has a small effect on convection in the weld pool.

  10. Mechanical and Transport Properties of the Poly(ethylene oxide)-Poly(acrylic acid) Double Network Hydrogel from Molecular Dynamic Simulations

    E-Print Network [OSTI]

    Goddard III, William A.

    . 1. Introduction A hydrogel is a three-dimensionally cross-linked hydrophilic polymer network. In this situation, the formation of interpenetrating but independently cross-linked double network (DN) hydrogelsMechanical and Transport Properties of the Poly(ethylene oxide)-Poly(acrylic acid) Double Network

  11. The influence of laser welding parameters on the microstructure and mechanical property of the as-jointed NiTi alloy wires

    E-Print Network [OSTI]

    Zheng, Yufeng

    The influence of laser welding parameters on the microstructure and mechanical property of the as September 2007; accepted 27 November 2007 Available online 4 December 2007 Abstract The Nd:YAG laser welding.%Ni) which had the same diameter of 1 mm. The wires were welded with different parameters, including impulse

  12. Estimating changes in the mechanical properties of the femur in the adult and aged rat due to adult-onset alcohol consumption

    E-Print Network [OSTI]

    Nguyen, Lyndon Phuoc

    2001-01-01T23:59:59.000Z

    Numerous studies have shown that alcohol has a disturbing effect on the mechanical properties of the skeleton. To determine whether alcohol has a deleterious effect on the adult skeleton, fifty-four, nine-month old, female Sprague-Dawley rats were...

  13. Mechanical Properties of End-Linked PEG/PDMS Hydrogels Jun Cui, Melissa A. Lackey, Gregory N. Tew,* and Alfred J. Crosby*

    E-Print Network [OSTI]

    Tew, Gregory N.

    deformability compared to metals and ceramics, and environmentally benign components.7,8 However, most synthetic focused on improving the mechanical properties of synthetic hydrogels by manipulating the network of filled rubber systems,15 several research groups have introduced a novel class of hydrogels with simple

  14. The effect of equal channel angular extrusion on the microstructure and mechanical properties of AISI 1552, AISI 4340, and A2 tool steels

    E-Print Network [OSTI]

    Shadat, Mohammed Anower

    1998-01-01T23:59:59.000Z

    that was imparted by ECAE may be associated with the increase in mechanical properties of 1552, 4340, and A2 tool steels. To my wonderful parents and brothers, Zainuddin, Salma, Saker, and Faruk Ahamed. To my most favorite teacher, Dr. M. I. . Smith...

  15. Prediction of convective heat transfer coefficients and their effects on distortion and mechanical properties of cylinder steel bodies quenched by gas cooling

    SciTech Connect (OSTI)

    Thuvander, A.; Melander, A.; Lind, M.; Lior, N.; Bark, F.H.

    1999-07-01T23:59:59.000Z

    The primary objectives of this study are to model the nature of the complex high-turbulence quenching cooling-gas flow, and to examine its effects on the resulting distortions and mechanical properties of the quenched piece, here bearing steel tubes and solid cylinders. A {kappa}-{epsilon} turbulent flow and heat transfer model adopted was found to predict the convective heat transfer coefficient (h) distribution reasonably well for Reynolds number up to about (0.3)10{sup 6}. At higher Reynolds number (to 10{sup 6}) it still predicts the nature of the flow well, but overpredicts h by up to 100% in the transition zone. The distributions of h around the body surface were used as the boundary condition for computing the temperature distribution history, phase transformations, distortions and mechanical properties of the quenched bodies. Increasing variation in h was found to increase the probability of large out-of-roundness, and nonuniformity in the properties.

  16. Impact of defects on the electrical transport, optical properties and failure mechanisms of GaN nanowires.

    SciTech Connect (OSTI)

    Armstrong, Andrew M.; Aubry, Sylvie; Shaner, Eric Arthur; Siegal, Michael P.; Li, Qiming; Jones, Reese E.; Westover, Tyler; Wang, George T.; Zhou, Xiao Wang; Talin, Albert Alec; Bogart, Katherine Huderle Andersen; Harris, C. Thomas; Huang, Jian Yu

    2010-09-01T23:59:59.000Z

    We present the results of a three year LDRD project that focused on understanding the impact of defects on the electrical, optical and thermal properties of GaN-based nanowires (NWs). We describe the development and application of a host of experimental techniques to quantify and understand the physics of defects and thermal transport in GaN NWs. We also present the development of analytical models and computational studies of thermal conductivity in GaN NWs. Finally, we present an atomistic model for GaN NW electrical breakdown supported with experimental evidence. GaN-based nanowires are attractive for applications requiring compact, high-current density devices such as ultraviolet laser arrays. Understanding GaN nanowire failure at high-current density is crucial to developing nanowire (NW) devices. Nanowire device failure is likely more complex than thin film due to the prominence of surface effects and enhanced interaction among point defects. Understanding the impact of surfaces and point defects on nanowire thermal and electrical transport is the first step toward rational control and mitigation of device failure mechanisms. However, investigating defects in GaN NWs is extremely challenging because conventional defect spectroscopy techniques are unsuitable for wide-bandgap nanostructures. To understand NW breakdown, the influence of pre-existing and emergent defects during high current stress on NW properties will be investigated. Acute sensitivity of NW thermal conductivity to point-defect density is expected due to the lack of threading dislocation (TD) gettering sites, and enhanced phonon-surface scattering further inhibits thermal transport. Excess defect creation during Joule heating could further degrade thermal conductivity, producing a viscous cycle culminating in catastrophic breakdown. To investigate these issues, a unique combination of electron microscopy, scanning luminescence and photoconductivity implemented at the nanoscale will be used in concert with sophisticated molecular-dynamics calculations of surface and defect-mediated NW thermal transport. This proposal seeks to elucidate long standing material science questions for GaN while addressing issues critical to realizing reliable GaN NW devices.

  17. Contribution of ankyrin-band 3 complexes to the organization and mechanical properties of the membrane skeleton of human erythrocyte

    SciTech Connect (OSTI)

    Shen, B.W. [Argonne National Lab., IL (United States). Biological and Medical Research Div.

    1995-02-01T23:59:59.000Z

    To understand the role of ankyrin-band 3 complexes in the organization of the spectrin-based membrane skeleton and its contribution to the mechanical properties of human erythrocytes, intact skeletons and single-layered skeleton leaflets were prepared from intact and physically sheared membrane ghosts, expanded in low salt buffer, and examined by transmission electron microscopy. While the structures of intact skeletons and single-layered skeleton leaflets shared many common features, including rigid junctional complexes of spectrin, actin, and band 4.1; short stretches ({approximately}50 {angstrom}) of flexible spectrin filaments; and globular masses of ankyrin-band 3 complexes situated close to the middle of the spectrin filaments, the definition of structural units in the intact skeleton is obscured by the superposition of the two layers. However, the spatial disposition of structural elements can be clearly defined in the images of the single-layered skeleton leaflets. Partially expanded skeletal leaflets contain conglomerates of ankyrin-band 3 complexes arranged in a circular or clove-leaf configuration that straddles multiple strands of thick spectrin cables, presumably reflecting the association of ankyrin-band 3 complexes on neighboring spectrin tetramers as well as the lateral association of the spectrin filaments. Hyperexpansion of the skeleton leaflets led to dissociation of the conglomerates of ankyrin-band 3 complexes, full-extension of the spectrin tetramers, and separation of the individual strands of spectrin tetramers. Clearly defined stands of spectrin tetramers in the hyperexpanded single-layered skeletal leaflets often contained two sets of globular protein masses that divided the spectrin tetramers into three segments of approximately equal length.

  18. Comparison of high temperature mechanical properties of two monolithic SiC ceramics and an Al{sub 2}O{sub 3}/SiC composite

    SciTech Connect (OSTI)

    Breder, K.

    1995-07-01T23:59:59.000Z

    Fast fracture strength, slow crack growth, and creep properties have been evaluated for three ceramics in air at room temperature and two elevated temperatures. The ceramics are candidate materials for heat exchangers in fossil energy systems, therefore, retained strength after coal ash exposure was also measured. At 1100{degrees}C the ceramics had acceptable mechanical properties, but two of them exhibited strength loss due to coal ash corrosion. At 1400{degrees}C creep and slow crack growth were observed in two of the materials, and the material which exhibited best resistance to coal ash showed unacceptably high creep rates.

  19. Estimating changes in the mechanical properties of the femur in the adult and aged rat due to adult-onset alcohol consumption 

    E-Print Network [OSTI]

    Nguyen, Lyndon Phuoc

    2001-01-01T23:59:59.000Z

    in animals 15 and 19 months of age, which is comparable to the young adult and aged human. 2. 6 Relevant Research on the Mechanical Properties of Rat Bone Emphasis on safety in automotive, aircraft and aerospace engineering has lead to a growing interest... the second set (eight- week alcohol plus six-week cessation) only consisted of an alcohol and a pair-fed group. At eight weeks and again at fourteen weeks, the rats were sacrificed and the femurs were removed for mechanical testing. This is summarized...

  20. International Journal of Crashworthiness, 2012, 17(3): p. 327-336 Mechanical Properties and Failure Mechanisms of Closed-Cell PVC Foams

    E-Print Network [OSTI]

    Gupta, Nikhil

    and Failure Mechanisms of Closed-Cell PVC Foams Michele Colloca, Gleb Dorogokupets, Nikhil Gupta1 , Maurizio chloride (PVC) foams with varying densities is conducted under tension, compression, and impact loading. Experimental results on four classes of high performance PVC foams show that the elastic modulus, strength

  1. Structural, magnetic, and mechanical properties of 5 {mu}m thick SmCo films suitable for use in microelectromechanical systems

    SciTech Connect (OSTI)

    Walther, A. [Institut Neel, CNRS-UJF, 25 rue des Martyrs, 38042 Grenoble (France); CEA Leti-MINATEC, 17 rue des Martyrs, 38054 Grenoble (France); Givord, D.; Dempsey, N. M. [Institut Neel, CNRS-UJF, 25 rue des Martyrs, 38042 Grenoble (France); Khlopkov, K.; Gutfleisch, O. [IFW Dresden, Institute of Metallic Materials, Helmholtzstr. 20, 01069 Dresden (Germany)

    2008-02-15T23:59:59.000Z

    5 {mu}m thick SmCo films were deposited onto Si substrates using triode sputtering. A study of the influence of deposition temperature (T{sub dep}{<=}600 deg. C) on the structural, magnetic, and mechanical properties has shown that optimum properties [highest degree of in-plane texture, maximum in-plane coercivity and remanence (1.3 and 0.8 T, respectively), and no film peel-off] are achieved for films deposited at the relatively low temperature of 350 deg. C. This temperature is compatible with film integration into microelectromechanical systems. The deposition rate was increased from 3.6 to 18 {mu}m/h by increasing the surface area of the target from 7 to 81 cm{sup 2} while keeping the target potential fixed. Mechanically intact films could be prepared by deposition onto prepatterned films or deposition through a mask.

  2. The Role of Friction Stir Welding on the Microstructure and Mechanical Properties of AZ31B-H24 Mg alloy

    SciTech Connect (OSTI)

    Darzi, Kh.; Saeid, T. [Advanced Materials Research Center - Faculty of Materials Engineering, Sahand University of Technology - Tabriz (Iran, Islamic Republic of)

    2011-12-26T23:59:59.000Z

    In this study, an attempt was made to join AZ31B magnesium alloy by friction stir welding (FSW) process. A single tool with cylindrical screw threaded pin was used to investigate the effect of welding parameters on microstructure and mechanical properties of stir zone (SZ). Several welds were made at different rotational ({omega}) and traverse ({upsilon}) speeds, while the {omega}/{upsilon} ratios were kept constant. The optical and scanning electron microscopy were used to study the variation of microstructure across the welds. Moreover, micro-hardness and tensile tests were carried out to evaluate the mechanical properties of joints. It was found that {omega} plays more significant role on the resulted grain structure than {upsilon}, and at a constant {omega}/{upsilon} ratio, decreasing rotational speed decreased the size of grains, and hence, improved the hardness value and the tensile strength of the SZ.

  3. The effect of aging at 343{degree}C on the mechanical properties and microstructure of type 308 stainless steel weldments

    SciTech Connect (OSTI)

    Alexander, D.J.; Alexander, K.B.; Miller, M.K.; Nanstad, R.K.

    1992-12-31T23:59:59.000Z

    The effect of long-term aging at intermediate temperatures on the mechanical properties of stainless steel welds has been studied. Three type 308 multipass shielded metal-arc welds with ferrite levels of 4, 8, and 12% were aged up to 20,000 h at 343C. Tensile tests showed little effect of aging on either the yield or ultimate tensile strengths, but the impact toughness was significantly degraded. The extent of the degradation increased with increasing ferrite content and increasing aging time. Examination of the microstructure with transmission electron microscopy and atom probe field-ion microscopy revealed that the ferrite phase had undergone spinodal decomposition as a result of aging. In addition, G-phase particles were observed at dislocations, and finer G-phase particles were homogeneously distributed throughout the ferrite phase. The changes in the mechanical properties and the fractography are discussed in light of the observed changes in the microstructure.

  4. Mechanical and thermal properties of h-MX{sub 2} (M?=?Cr, Mo, W; X?=?O, S, Se, Te) monolayers: A comparative study

    SciTech Connect (OSTI)

    Çak?r, Deniz, E-mail: deniz.cakir@uantwerpen.be; Peeters, François M., E-mail: francois.peeters@uantwerpen.be [Department of Physics, University of Antwerp, 2610 Antwerpen (Belgium); Sevik, Cem, E-mail: csevik@anadolu.edu.tr [Department of Mechanical Engineering, Faculty of Engineering, Anadolu University, Eskisehir TR 26555 (Turkey)

    2014-05-19T23:59:59.000Z

    Using density functional theory, we obtain the mechanical and thermal properties of MX{sub 2} monolayers (where M?=?Cr, Mo, W and X?=?O, S, Se, Te). The ?-centered phonon frequencies (i.e., A{sub 1}, A{sub 2}{sup ?}, E?, and E?), relative frequency values of A{sub 1}, and E? modes, and mechanical properties (i.e., elastic constants, Young modulus, and Poisson's ratio) display a strong dependence on the type of metal and chalcogenide atoms. In each chalcogenide (metal) group, transition-metal dichalcogenides (TMDCs) with W (O) atom are found to be much stiffer. Consistent with their stability, the thermal expansion of lattice constants for TMDCs with O (Te) is much slower (faster). Furthermore, in a heterostructure of these materials, the difference of the thermal expansion of lattice constants between the individual components becomes quite tiny over the whole temperature range. The calculated mechanical and thermal properties show that TMDCs are promising materials for heterostructures.

  5. Influence of germanium and the melting method on the mechanical properties of NM23KhYu alloy at high temperatures

    SciTech Connect (OSTI)

    Lebedev, D.V.; Rozonova, V.M.

    1986-05-01T23:59:59.000Z

    The purpose of the investigation was to increase the plasticity and ductility of NM233KhYu alloy without a detrimental effect on its service properties, selection of methods evaluation of placticity and ductility at increased temperatures, and establishment on the basis of the results obtained of the optimum temperature range for hot working by pressure. To evaluate the mechanical properties at increased temperature tension, impact strength and torsion tests were made. Alloying with germanium of NM23KhYu alloy leads to a two-to-three-time increase in its impact strength. Electron beam remelting of NM23KhYu alloy with germanium increases the impact strength, and the characteristics of plasticity by 1.5-2 times in comparison with the similar properties of this alloy produced by vacuum induction melting.

  6. Bulk and mechanical properties of the Paintbrush tuff recovered from borehole USW NRG-7/7A: Data report. Yucca Mountain Site Characterization Project

    SciTech Connect (OSTI)

    Martin, R.J.; Boyd, P.J.; Noel, J.S. [New England Research, Inc. White River Junction, VT (United States); Price, R.H. [Sandia National Labs., Albuquerque, NM (United States)

    1995-05-01T23:59:59.000Z

    An integral part of the licensing procedure for the potential nuclear waste repository at Yucca Mountain, Nevada, involves prediction of the in situ rheology for the design and construction of the facility and the emplacement of canisters containing radioactive waste. The data used to model the thermal and mechanical behavior of the repository and surrounding lithologies include dry and saturated bulk densities, average grain density, porosity, compressional and shear wave velocities, elastic moduli, and compressional and tensional fracture strengths. In this study, a suite of experiments was performed on cores recovered from the USW NRG-717A borehole drilled in support of the Exploratory Studies Facility (ESF) at Yucca Mountain. USW NRG-7/7A was drilled to a depth of 1,513.4 feet through five thermal/mechanical units of Paintbrush tuff and terminating in the tuffaceous beds of the Calico IEUS. The thermal/mechanical stratigraphy was defined by Orfiz et al. to group rock horizons of similar properties for the purpose of simplifying modeling efforts. The relationship between the geologic stratigraphy and the thermal/mechanical stratigraphy is presented. The tuff samples in this study have a wide range of welding characteristics, and a smaller range of mineralogy and petrology characteristics. Generally, the samples are silicic, ash-fall tuffs that exhibit large variability in their elastic and strength properties.

  7. Mechanical and Transport Properties of Layer-by-Layer Electrospun Composite Proton Exchange Membranes for Fuel Cell Applications

    E-Print Network [OSTI]

    Mannarino, Matthew M.

    Composite membranes composed of highly conductive and selective layer-by-layer (LbL) films and electrospun fiber mats were fabricated and characterized for mechanical strength and electrochemical selectivity. The LbL ...

  8. Energy Dissipation Properties of Cementitious Materials: Applications in Mechanical Damping and Characterization of Permeability and Moisture State 

    E-Print Network [OSTI]

    Leung, Chin

    2012-10-19T23:59:59.000Z

    The study of mechanical energy and electrical energy dissipation in cementitious materials can lead to development of high damping concrete for structural applications, and new non-destructive testing techniques for use ...

  9. Effect of composite microstructure on electrical and mechanical properties of poly(vinyl acetate) composites with carbon black and clay.

    E-Print Network [OSTI]

    Miriyala, Sethu M.

    2009-05-15T23:59:59.000Z

    The electrical and mechanical behavior of carbon black filled poly(vinyl acetate) latex-based and solution-based polymer composites was examined. A set of experiments were performed to distinguish composites with a segregated network (emulsion...

  10. Aspect Ratio Effect of Functionalized/Non-Functionalized Multiwalled Carbon Nanotubes on the Mechanical Properties of Cementitious Materials 

    E-Print Network [OSTI]

    Ashour, Ahmad

    2012-10-19T23:59:59.000Z

    ), modulus of elasticity, and modulus of toughness. The results for the different nanocomposite batches were compared with the plain cement (reference) batch. The mechanical testing results showed that at 28 days almost all of the MWCNTs composites...

  11. Influence of thermal history on the mechanical properties of carbon fiber-acrylate composites cured by electron beam and thermal processes

    SciTech Connect (OSTI)

    Vautard, Frederic [ORNL] [ORNL; Ozcan, Soydan [ORNL] [ORNL; Poland, Laura E [ORNL] [ORNL; Meyer III, Harry M [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    The mechanical properties of an acrylate resin and its carbon fiber composite, as well as the adhesion strength between them, were characterized in the case of thermal and electron beam curing. The thermal history during the cure was also recorded. It was shown that the properties of the matrix were similar but that the thermal history during the curing had a direct influence on the type of interactions that were generated at the interface, leading to different level of adhesion strength and level of performance for the associated composites. In the case of a thermal cure, the thermal profile allowed the generation of covalent bonding at the interface, leading to a high level of adhesion strength, which was not the case for electron beam curing. The thermal history during the cure appeared to be a determining parameter for the level of performance of composites cured by electron beam.

  12. Magnetic and electric bulge-test instrument for the determination of coupling mechanical properties of functional free-standing films and flexible electronics

    SciTech Connect (OSTI)

    Yu, Zejun; Li, Faxin; Pei, Yongmao, E-mail: peiym@pku.edu.cn, E-mail: fangdn@pku.edu.cn; Fang, Daining, E-mail: peiym@pku.edu.cn, E-mail: fangdn@pku.edu.cn [State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871 (China); Mao, Weiguo [Faculty of Materials and Optoelectronics Physics, Xiangtan University, Hunan 411105 (China); Feng, Xue [Department of Engineering Mechanics, Tsinghua University, Beijing 100084 (China)

    2014-06-15T23:59:59.000Z

    For the first time a novel multi-field bulge-test instrument which enables measurements of the biaxial mechanical properties and electro-magnetic-mechanical coupling effect of free-standing films in external magnetic/electric fields was proposed. The oil pressure was designed with two ranges, 0–1 MPa for elastic small deformation and 0–7 MPa for plastic/damage large deformation. A magnetic field that was horizontal and uniform in the film plane was supplied by a hollow cylindrical magnet. The magnitude could be changed from 0 to 10?000 Oe by adjusting the position of the testing film. Meanwhile, an electric field applied on the film was provided by a voltage source (Maximum voltage: 1000 V; Maximum current: 1 A). Various signals related to deformation, mechanical loading, magnetic field, and electric field could be measured simultaneously without mutual interference, which was confirmed by the coincidence of the measured P-H curves for titanium (Ti)/nickel (Ni) specimens with/without external fields. A hardening phenomenon under magnetic/electric fields was observed for Ni and lead zirconate titanate specimens. The multi-field bulge-test instrument will provide a powerful research tool to study the deformation mechanism of functional films and flexible electronics in the coupling field.

  13. Effect of oxidation on the mechanical properties of Nextel{trademark}312/BN/Blackglas{trademark} composites

    SciTech Connect (OSTI)

    Vaidyanathan, K.R.; Cannon, W.G.; Danforth, S.C. [Rutgers, The State Univ. of New Jersey, Piscataway, NJ (United States). Center for Ceramic Research; Tobin, A.G. [Grumman Aerospace and Electronics, Bethpage, NY (United States); Holmes, J.W. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Mechanical Engineering

    1995-10-01T23:59:59.000Z

    Preceramic polymers are attractive precursor materials for the production of low cost continuous fiber reinforced ceramic composites (CFCC) into near net shape components. Currently, CFCC components based upon a Blackglas{trademark} matrix reinforced with Nextel{trademark}312 fibers with a BN rich surface layer are being investigated for gas turbine engine applications. The effects of oxidation on tensile and bend properties were investigated after exposure to flowing air at 600 C for 20--1,000h. A significant reduction in the tensile properties accompanied by increases in fiber pull-out was observed after oxidation for 96 hours. After 500 hours oxidation, strength decreased by 50% relative to as-prepared composites. These results indicate that oxidation beyond 200 hours may be embrittling the composite.

  14. Determination of Interfacial Mechanical Properties of Ceramic Composites by the Compression of Micro-pillar Test Specimens

    SciTech Connect (OSTI)

    Shih, Chunghao [ORNL; Katoh, Yutai [ORNL; Leonard, Keith J [ORNL; Bei, Hongbin [ORNL; Lara-Curzio, Edgar [ORNL

    2013-01-01T23:59:59.000Z

    A novel method to determine the fiber-matrix interfacial properties of ceramic matrix composites is proposed and evaluated; where micro- pillar samples containing inclined fiber/matrix interfaces were prepared from a SiC fiber reinforced SiC matrix composites then compression-tested using the nano-indentation technique. This new test method employs a simple geometry and mitigates the uncertainties associated with complex stress state in the conventional single filament push-out method for the determination of interfacial properties. Based on the test results using samples with different interface orientations , the interfacial debond shear strength and the internal friction coefficient are explicitly determined and compared with values obtained by other test methods.

  15. Improvement in the Mechanical Properties of B-Staged Carbon Nanotube/Epoxy Based Thin Film Systems

    E-Print Network [OSTI]

    White, Kevin

    2011-01-11T23:59:59.000Z

    in the amount of composite materials used in aircraft. However, the growth has been significantly slower than expected due to the development of lightweight alloys, advanced joining _______________ This thesis follows the style of Carbon. 2 techniques... materials using carbon nanotubes as a reinforcing agent within a polymer matrix. Multifunctional composite materials promise to simultaneously decrease weight, increase strength, and allow for improved performance over a range of mechanical, thermal...

  16. Influence of the interface structure on the thermo-mechanical properties of Cu-X (X = Cr or B)/carbon fiber composites

    SciTech Connect (OSTI)

    Veillere, A., E-mail: veillere@icmcb-bordeaux.cnrs.fr [CNRS, Universite de Bordeaux, ICMCB, 87 Avenue du Docteur Albert Schweitzer, 33608 Pessac (France); Heintz, J.-M. [CNRS, Universite de Bordeaux, ICMCB, 87 Avenue du Docteur Albert Schweitzer, 33608 Pessac (France)] [CNRS, Universite de Bordeaux, ICMCB, 87 Avenue du Docteur Albert Schweitzer, 33608 Pessac (France); Chandra, N. [Engineering Mechanics, University of Nebraska-Lincoln, Lincoln, NE 68588-0642 (United States)] [Engineering Mechanics, University of Nebraska-Lincoln, Lincoln, NE 68588-0642 (United States); Douin, J. [CNRS, CEMES, 29 Rue Jeanne Marvig, F-31055 Toulouse (France)] [CNRS, CEMES, 29 Rue Jeanne Marvig, F-31055 Toulouse (France); Lahaye, M.; Lalet, G.; Vincent, C.; Silvain, J.-F. [CNRS, Universite de Bordeaux, ICMCB, 87 Avenue du Docteur Albert Schweitzer, 33608 Pessac (France)] [CNRS, Universite de Bordeaux, ICMCB, 87 Avenue du Docteur Albert Schweitzer, 33608 Pessac (France)

    2012-02-15T23:59:59.000Z

    Highlights: Black-Right-Pointing-Pointer Two copper alloys/carbon fibers composites have been produced. Black-Right-Pointing-Pointer Correlation of the thermo-mechanical properties with the microstructure and the chemistry. Black-Right-Pointing-Pointer A composite with CTE 25% lower than a classic Cu/CF composite has been obtained. -- Abstract: This study focuses on the fabrication, for power electronics applications, of adaptive heat sink material using copper alloys/carbon fibers (CF) composites. In order to obtain composite material with good thermal conductivity and a coefficient of thermal expansion close to the ceramic substrate, it is necessary to have a strong matrix/reinforcement bond. Since there is no reaction between copper and carbon, a carbide element (chromium or boron) is added to the copper matrix to create a strong chemical bond. Composite materials (Cu-B/CF and Cu-Cr/CF) have been produced by a powder metallurgy process followed by an annealing treatment in order to create the carbide at the interphase. Chemical (Electron Probe Micro-Analysis, Auger Electron Spectroscopy) and microstructural (Scanning and Transmission Electron Microscopies) techniques were used to study the location of the alloying element and the carbide formation before and after diffusion. Finally, the thermo-mechanical properties have been measured and a promising composite material with a coefficient of thermal expansion 25% lower than a classic copper/carbon heat sink has been obtained.

  17. Production Mechanism, Number Concentration, Size Distribution, Chemical Composition, and Optical Properties of Sea Spray Aerosols Workshop, Summer 2012

    SciTech Connect (OSTI)

    Meskhidze, Nicholas [NCSU] [NCSU

    2013-10-21T23:59:59.000Z

    The objective of this workshop was to address the most urgent open science questions for improved quantification of sea spray aerosol-radiation-climate interactions. Sea spray emission and its influence on global climate remains one of the most uncertain components of the aerosol-radiation-climate problem, but has received less attention than other aerosol processes (e.g. production of terrestrial secondary organic aerosols). Thus, the special emphasis was placed on the production flux of sea spray aerosol particles, their number concentration and chemical composition and properties.

  18. Bulk, thermal, and mechanical properties of the Topopah Spring Member of the Paintbrush Tuff, Yucca Mountain, Nevada

    SciTech Connect (OSTI)

    Nimick, F.B.; Schwartz, B.M.

    1987-09-01T23:59:59.000Z

    Experimental data on matrix porosity, grain density, thermal expansion, compressive strength, Young`s modulus, Poisson`s ratio, and axial strain at failure for samples from the Topopah Spring Member of the Paintbrush Tuff are compiled. Heat capacity and emissivity also are discussed. Data have been analyzed for spatial variability; slight variability is observed for matrix porosity, grain density, and thermal expansion coefficient. Estimates of in situ values for some properties, such as bulk density and heat capacity, are presented. Vertical in situ stress as a function of horizontal and vertical location has been calculated. 96 refs., 37 figs., 27 tabs.

  19. Mechanical property changes and microstructures of dispersion-strengthened copper alloys after neutron irradiation at 411, 414, and 529 degree C

    SciTech Connect (OSTI)

    Anderson, K.R.; Stubbins, J.F. (Illinois Univ., Urbana, IL (USA)); Garner, F.A.; Hamilton, M.L. (Pacific Northwest Lab., Richland, WA (USA))

    1990-06-01T23:59:59.000Z

    Dispersion strengthened copper alloys have shown promise for certain high heat flux applications in both near term and long term fusion devices. This study examines mechanical properties changes and microstructural evolution in several oxide dispersion strengthened alloys which were subjected to high levels of irradiation-induced displacement damage. Irradiations were carried out in FFTF to 34 and 50 dpa at 411--414{degree}C and 32 dpa at 529{degree}C. The alloys include several oxide dispersion-strengthened alloys based on the Cu-Al system, as well as ones based on the Cu-Cr and Cu-Hf systems. Of this group, certain of the Cu-Al alloys, those produced by an internal oxidation technique to contain alumina weight fractions of 0.15 to 0.25% outperformed the other alloys in all respects. These alloys, designated CuAl15, CuAl20, and CuAl25, were found to be resistant to void swelling up to 50 dpa at 414{degree}C, and to retain their superior mechanical and physical properties after extended irradiation. The major factor which controls the stability during irradiation was found to be the dispersoid volume fraction and distribution. The other alloys examined were less resistant to radiation-induced properties changes for a variety of reasons. Some of these include dispersoid redistribution by ballistic resolution, effects of retained dissolved oxygen, and non-uniformity of dispersion distribution. The effect of laser welding was also examined. This joining technique was found to be unacceptable since it destroys the dispersoid distribution and thereby the resistance of the alloys to radiation-induced damage.

  20. Method of making composition suitable for use as inert electrode having good electrical conductivity and mechanical properties

    DOE Patents [OSTI]

    Ray, Siba P. (Pittsburgh, PA); Rapp, Robert A. (Columbus, OH)

    1986-01-01T23:59:59.000Z

    An improved inert electrode composition is suitable for use as an inert electrode in the production of metals such as aluminum by the electrolytic reduction of metal oxide or metal salt dissolved in a molten salt bath. The composition comprises one or more metals or metal alloys and metal compounds which may include oxides of the metals comprising the alloy. The alloy and metal compounds are interwoven in a network which provides improved electrical conductivity and mechanical strength while preserving the level of chemical inertness necessary for such an electrode to function satisfactorily.

  1. The structural and mechanical properties of a Cu??Zr??(at. %) alloy processed by High-Velocity-Injection (HVI)

    E-Print Network [OSTI]

    Hays, Charles C.

    1986-01-01T23:59:59.000Z

    /vacuum coupled pressure gradient. The molten jet rapidly solidifies, as it is in good thermal contact wi th the cir- cular walls of the copper channel. This process (melting and injection) is carried out in inert protective atmospheres (helium). The samples... produced are in the form of cylindrical rods with large length to diameter ratios (40:1). The samples exhibit a good sur- face finish and are of high density. The structural and mechanical characterization of the Cu6 Zr 0(at. %%u) samples produced...

  2. Method of making composition suitable for use as inert electrode having good electrical conductivity and mechanical properties

    DOE Patents [OSTI]

    Ray, S.P.; Rapp, R.A.

    1986-04-22T23:59:59.000Z

    An improved inert electrode composition is suitable for use as an inert electrode in the production of metals such as aluminum by the electrolytic reduction of metal oxide or metal salt dissolved in a molten salt bath. The composition comprises one or more metals or metal alloys and metal compounds which may include oxides of the metals comprising the alloy. The alloy and metal compounds are interwoven in a network which provides improved electrical conductivity and mechanical strength while preserving the level of chemical inertness necessary for such an electrode to function satisfactorily. 8 figs.

  3. Mechanical properties of near-{gamma} titanium aluminides reinforced with high volume percentages of TiB{sub 2}

    SciTech Connect (OSTI)

    VanMeter, M.L. [Naval Air Warfare center, Patuxent River, MD (United States). Aircraft Div.] [Naval Air Warfare center, Patuxent River, MD (United States). Aircraft Div.; Kampe, S.L. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States)] [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States); Christodoulou, L. [Imperial Coll. of Science, Technology, and Medicine, London (United Kingdom)] [Imperial Coll. of Science, Technology, and Medicine, London (United Kingdom)

    1996-04-15T23:59:59.000Z

    Near-{gamma} ({alpha}{sub 2}-Ti{sub 3}Al + {gamma}-TiAl) titanium aluminide intermetallic compounds are presently undergoing extensive development as potential lower-density substitutes for conventional high temperature metallic alloys. In this article the authors describe the mechanical behavior of a series of binary near-{gamma} titanium aluminides (i.e., Ti-xAl, where x {approx} 43--48 atomic percent) reinforced with 40--50 volume percent (v%) of a discontinuous dispersion of titanium diboride (TiB{sub 2}) particulate. The composites were synthesized via XD{reg_sign} processing, and subsequently consolidated into bulk form using conventional powder metallurgy (P/M) techniques. For composites comprised of such large volume percentages of ceramic, it is suggested and will be shown that it is most appropriate to evaluate and offer a perspective of their evolved mechanical behavior through their comparison to traditional structural ceramics, e.g., silicon carbide (SiC) and alumina (Al{sub 2}O{sub 3}).

  4. Characterization of the molecular structure and mechanical properties of polymer surfaces and protein/polymer interfaces by sum frequency generation vibrational spectroscopy and atomic force microscopy

    SciTech Connect (OSTI)

    Koffas, Telly Stelianos

    2004-05-15T23:59:59.000Z

    Sum frequency generation (SFG) vibrational spectroscopy, atomic force microscopy (AFM), and other complementary surface-sensitive techniques have been used to study the surface molecular structure and surface mechanical behavior of biologically-relevant polymer systems. SFG and AFM have emerged as powerful analytical tools to deduce structure/property relationships, in situ, for polymers at air, liquid and solid interfaces. The experiments described in this dissertation have been performed to understand how polymer surface properties are linked to polymer bulk composition, substrate hydrophobicity, changes in the ambient environment (e.g., humidity and temperature), or the adsorption of macromolecules. The correlation of spectroscopic and mechanical data by SFG and AFM can become a powerful methodology to study and engineer materials with tailored surface properties. The overarching theme of this research is the interrogation of systems of increasing structural complexity, which allows us to extend conclusions made on simpler model systems. We begin by systematically describing the surface molecular composition and mechanical properties of polymers, copolymers, and blends having simple linear architectures. Subsequent chapters focus on networked hydrogel materials used as soft contact lenses and the adsorption of protein and surfactant at the polymer/liquid interface. The power of SFG is immediately demonstrated in experiments which identify the chemical parameters that influence the molecular composition and ordering of a polymer chain's side groups at the polymer/air and polymer/liquid interfaces. In general, side groups with increasingly greater hydrophobic character will be more surface active in air. Larger side groups impose steric restrictions, thus they will tend to be more randomly ordered than smaller hydrophobic groups. If exposed to a hydrophilic environment, such as water, the polymer chain will attempt to orient more of its hydrophilic groups to the surface in order to minimize the total surface energy. With an understanding of the structural and environmental parameters which govern polymer surface structure, SFG is then used to explore the effects of surface hydrophobicity and solvent polarity on the orientation and ordering of amphiphilic neutral polymers adsorbed at the solid/liquid interface. SFG spectra show that poly(propylene glycol) (PPG) and poly(ethylene glycol) (PEG) adsorb with their hydrophobic moieties preferentially oriented toward hydrophobic polystyrene surfaces. These same moieties, however, disorder when adsorbed onto a hydrophilic silica/water interface. Water is identified as a critical factor for mediating the orientation and ordering of hydrophobic moieties in polymers adsorbed at hydrophobic interfaces. The role of bulk water content and water vapor, as they influence hydrogel surface structure and mechanics, continues to be explored in the next series of experiments. A method was developed to probe the surface viscoelastic properties of hydroxylethyl methacrylate (HEMA) based contact lens materials by analyzing AFM force-distance curves. AFM analysis indicates that the interfacial region is dehydrated, relative to the bulk. Experiments performed on poly(HEMA+MA) (MA = methacrylic acid), a more hydrophilic copolymer with greater bulk water content, show even greater water depletion at the surface. SFG spectra, as well as surface energy arguments, suggest that the more hydrophilic polymer component (such as MA) is not favored at the air interface; this may explain anomalies in water retention at the hydrogel surface. Adsorption of lysozyme onto poly(HEMA+MA) was found to further reduce near-surface viscous behavior, suggesting lower surface water content. Lastly, protein adsorption is studied using a model polymer system of polystyrene covalently bound with a monolayer of bovine serum albumin. SFG results indicate that some amino acid residues in proteins adopt preferred orientations. SFG spectra also show that the phenyl rings of the bare polystyrene substrate in contact with air or

  5. Effects of Surface Treatments on Mechanical Properties and Water Resistance of Kenaf Fiber-Reinforced Unsaturated Polyester Composites

    SciTech Connect (OSTI)

    Ren, Xiaofeng; Qui, Renhui; Fifield, Leonard S.; Simmons, Kevin L.; li, Kaichang

    2012-05-17T23:59:59.000Z

    Effects of surface treatments on the strength and water resistance of kenaf fiber-reinforced unsaturated polyester (UPE) composites were investigated. A new coupling agent that consists of 1,6-diisocyanato-hexane (DIH) and 2-hydroxylethyl acrylate (HEA) was investigated for surface treatments of kenaf fibers. The surface treatments were found to significantly enhance the tensile strength, modulus of rupture, modulus of elasticity, and water resistance of the resulting kenaf UPE composites. Fourier transform infrared spectroscopy (FTIR) confirmed that DIH-HEA was covalently bonded onto kenaf fibers. Scanning electron microscopy (SEM) images of the composites revealed that chemical treatment of kenaf fibers with a combination of DIH and HEA improved the interfacial adhesion between kenaf fibers and UPE resin in the DIHHEA-treated kenafUPE composites. The mechanisms by which the chemical treatment of kenaf fiber surfaces improved strength and water resistance of the resulting kenaf UPE composites were discussed.

  6. Specification of CuCrZr Alloy Properties after Various Thermo-Mechanical Treatments and Design Allowables including Neutron Irradiation Effects

    SciTech Connect (OSTI)

    Barabash, Vladimir [ITER Organization, Saint Paul Lez Durance, France] [ITER Organization, Saint Paul Lez Durance, France; Kalinin, G. M. [RDIPE, P.O. Box 788, 101000 Moscow, Russia] [RDIPE, P.O. Box 788, 101000 Moscow, Russia; Fabritsiev, Sergei A. [D.V. Efremov Scientific Research Institute, St. Petersburg, Russia] [D.V. Efremov Scientific Research Institute, St. Petersburg, Russia; Zinkle, Steven J [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    Precipitation hardened CuCrZr alloy is a promising heat sink and functional material for various applica- tions in ITER, for example the first wall, blanket electrical attachment, divertor, and heating systems. Three types of thermo-mechanical treatment were identified as most promising for the various applica- tions in ITER: solution annealing, cold working and ageing; solution annealing and ageing; solution annealing and ageing at non-optimal condition due to specific manufacturing processes for engineer- ing-scale components. The available data for these three types of treatments were assessed and mini- mum tensile properties were determined based on recommendation of Structural Design Criteria for the ITER In-vessel Components. The available data for these heat treatments were analyzed for assess- ment of neutron irradiation effect. Using the definitions of the ITER Structural Design Criteria the design allowable stress intensity values are proposed for CuCrZr alloy after various heat treatments.

  7. Ag-catalyzed synthesis of europium borate Eu(BO{sub 2}){sub 3} nanowires, growth mechanism and luminescent properties

    SciTech Connect (OSTI)

    Yang, Lan, E-mail: yanglan1116@126.com [Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules and College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062 (China)] [Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules and College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062 (China); Zhou, Liqun, E-mail: zlq@hubu.edu.cn [Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules and College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062 (China)] [Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules and College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062 (China); Huang, Ying; Tang, Ziwei [Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules and College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062 (China)] [Ministry of Education Key Laboratory for the Synthesis and Application of Organic Functional Molecules and College of Chemistry and Chemical Engineering, Hubei University, Wuhan 430062 (China)

    2011-02-15T23:59:59.000Z

    Eu(BO{sub 2}){sub 3} nanowires with diameters of 10-20 nm were fabricated through direct sintering Eu(NO{sub 3}){sub 3}.6H{sub 2}O and H{sub 3}BO{sub 3} with Ag as catalyst. The result of X-ray diffraction (XRD) indicated that the nanowire was single-crystalline with body-centered monoclinic structure. Based on the fact that Ag nanoparticles attached to the tips and middles of nanowires, a vapor-liquid-solid (VLS) growth mechanism of the Eu(BO{sub 2}){sub 3} nanowires is proposed. Three well-defined stages have been clearly identified during the process: Ag-Eu-B-O cluster process, crystal nucleation, and axial growth. The photoluminescence characteristics under UV excitation were investigated. The dominated Eu{sup 3+} orange-red emission corresponding to the magnetic dipole transition {sup 5}D{sub 0} {yields} {sup 7}F{sub 1} is centered at 591 nm, indicating that Eu{sup 3+} is located at high symmetry crystal field with inversion center.

  8. Thermoelectric properties of p-type (Bi{sub 1{minus}x}Sb{sub x}){sub 2}Te{sub 3} fabricated by mechanical alloying process

    SciTech Connect (OSTI)

    Jung, B.Y.; Choi, J.S.; Oh, T.S.; Hyun, D.B.

    1997-07-01T23:59:59.000Z

    Thermoelectric properties of polycrystalline (Bi{sub 1{minus}x}Sb{sub x}){sub 2}Te{sub 3} (0.75 {le} x {le} 0.85), fabricated by mechanical alloying and hot pressing methods, have been investigated. Formation of (Bi{sub 0.25}Sb{sub 0.75}){sub 2}Te{sub 3} alloy powder was completed by mechanical alloying for 5 hours at ball-to-material ratio of 5:1, and processing time for (Bi{sub 1{minus}sub x}Sb{sub x}){sub 2}Te{sub 3} formation increased with Sb{sub 2}Te{sub 3} content x. When (Bi{sub 0.25}Sb{sub 0.75}){sub 2}Te{sub 3} was hot pressed at temperatures ranging from 300 C to 550 C for 30 minutes, figure-of-merit increased with hot pressing temperature and maximum value of 2.8 x 10{sup {minus}3}/K could be obtained by hot pressing at 550 C. When hot pressed at 550 C, (Bi{sub 0.2}Sb{sub 0.8}){sub 2}Te{sub 3} exhibited figure-of-merit of 2.92 x 10{sup {minus}3}/K, which could be improved to 2.97 x 10{sup {minus}3}/K with addition of 1 wt% Sb as acceptor dopant.

  9. Mechanical properties of ZrB2- and HfB2-based ultra-high temperature ceramics fabricated by spark plasma sintering

    SciTech Connect (OSTI)

    Zapata-Solvas, E. [Imperial College, London; Jayaseelan, D. [Imperial College, London; Lin, Hua-Tay [ORNL; Brown, P. [DSTL, Porton Down, Salisbury, Wiltshire, UK; Lee, W.E. [Imperial College, London

    2013-01-01T23:59:59.000Z

    Flexural strengths at room temperature, at 1400 C in air and at room temperature after 1 h oxidation at 1400 C were determined for ZrB2- and HfB2-based ultra-high temperature ceramics (UHTCs). Defects caused by electrical discharge machining (EDM) lowered measured strengths significantly and were used to calculate fracture toughness via a fracture mechanics approach. ZrB2 with 20 vol.% SiC had room temperature strength of 700 90 MPa, fracture toughness of 6.4 0.6 MPa, Vickers hardness at 9.8 N load of 21.1 0.6 GPa, 1400 C strength of 400 30 MPa and room temperature strength after 1 h oxidation at 1400 C of 678 15 MPa with an oxide layer thickness of 45 5 m. HfB2 with 20 vol.% SiC showed room temperature strength of 620 50 MPa, fracture toughness of 5.0 0.4 MPa, Vickers hardness at 9.8 N load of 27.0 0.6 GPa, 1400 C strength of 590 150 MPa and room temperature strength after 1 h oxidation at 1400 C of 660 25 MPa with an oxide layer thickness of 12 1 m. 2 wt.% La2O3 addition to UHTCs slightly reduced mechanical performance while increasing tolerance to property degradation after oxidation and effectively aided internal stress relaxation during spark plasma sintering (SPS) cooling, as quantified by X-ray diffraction (XRD). Slow crack growth was suggested as the failure mechanism at high temperatures as a consequence of sharp cracks formation during oxidation.

  10. Determining the Mechanical Constitutive Properties of Metals as Function of Strain Rate and temperature: A Combined Experimental and Modeling Approach

    SciTech Connect (OSTI)

    Ian Robertson

    2007-04-28T23:59:59.000Z

    Development and validation of constitutive models for polycrystalline materials subjected to high strain-rate loading over a range of temperatures are needed to predict the response of engineering materials to in-service type conditions. To account accurately for the complex effects that can occur during extreme and variable loading conditions, requires significant and detailed computational and modeling efforts. These efforts must be integrated fully with precise and targeted experimental measurements that not only verify the predictions of the models, but also provide input about the fundamental processes responsible for the macroscopic response. Achieving this coupling between modeling and experiment is the guiding principle of this program. Specifically, this program seeks to bridge the length scale between discrete dislocation interactions with grain boundaries and continuum models for polycrystalline plasticity. Achieving this goal requires incorporating these complex dislocation-interface interactions into the well-defined behavior of single crystals. Despite the widespread study of metal plasticity, this aspect is not well understood for simple loading conditions, let alone extreme ones. Our experimental approach includes determining the high-strain rate response as a function of strain and temperature with post-mortem characterization of the microstructure, quasi-static testing of pre-deformed material, and direct observation of the dislocation behavior during reloading by using the in situ transmission electron microscope deformation technique. These experiments will provide the basis for development and validation of physically-based constitutive models. One aspect of the program involves the direct observation of specific mechanisms of micro-plasticity, as these indicate the boundary value problem that should be addressed. This focus on the pre-yield region in the quasi-static effort (the elasto-plastic transition) is also a tractable one from an experimental and modeling viewpoint. In addition, our approach will minimize the need to fit model parameters to experimental data to obtain convergence. These are critical steps to reach the primary objective of simulating and modeling material performance under extreme loading conditions. During this project, the following achievements have been obtained: 1. Twins have been observed to act as barriers to dislocation propagation and as sources of and sinks to dislocations. 2. Nucleation of deformation twins in nitrogen strengthened steel is observed to be closely associated with planar slip bands. The appearance of long twins through heavily dislocated microstructures occurs by short twins nucleating at one slip band, propagating through the dislocation-free region, and terminating at the next slip band. This process is repeated throughout the entire grain. 3. A tamped-laser ablation loading technique has been developed to introduce high strain rate, high stress and low strains. 4. Both dislocation slip and twinning are present in high strain-rate deformed zirconium, with the relative contribution of each mode to the deformation depending on the initial texture. 5. In situ IR thermal measurements have been used to show that the majority of plastic work is dissipated as heat even under conditions in which twinning is the dominant deformation mode.

  11. Synchrotron X-ray diffraction studies of phase transitions and mechanical properties of nanocrystalline materials at high pressure

    SciTech Connect (OSTI)

    Prilliman, Gerald Stephen

    2003-09-01T23:59:59.000Z

    The behavior of nanocrystals under extreme pressure was investigated using synchrotron x-ray diffraction. A major part of this investigation was the testing of a prototype synchrotron endstation on a bend magnet beamline at the Advanced Light Source for high pressure work using a diamond anvil cell. The experiments conducted and documented here helped to determine issues of efficiency and accuracy that had to be resolved before the construction of a dedicated ''super-bend'' beamline and endstation. The major conclusions were the need for a cryo-cooled monochromator and a fully remote-controllable pressurization system which would decrease the time to change pressure and greatly reduce the error created by the re-placement of the diamond anvil cell after each pressure change. Two very different types of nanocrystal systems were studied, colloidal iron oxide (Fe{sub 2}O{sub 3}) and thin film TiN/BN. Iron oxide nanocrystals were found to have a transition from the {gamma} to the {alpha} structure at a pressure strongly dependent on the size of the nanocrystals, ranging from 26 GPa for 7.2 nm nanocrystals to 37 GPa for 3.6 nm nanocrystals. All nanocrystals were found to remain in the {alpha} structure even after release of pressure. The transition pressure was also found, for a constant size (5.7 nm) to be strongly dependent on the degree of aggregation of the nanocrystals, increasing from 30 GPa for completely dissolved nanocrystals to 45 GPa for strongly aggregated nanocrystals. Furthermore, the x-ray diffraction pattern of the pressure induced {alpha} phase demonstrated a decrease in intensity for certain select peaks. Together, these observations were used to make a complete picture of the phase transition in nanocrystalline systems. The size dependence of the transition was interpreted as resulting from the extremely high surface energy of the {alpha} phase which would increase the thermodynamic offset and thereby increase the kinetic barrier to transition that must be overridden with pressure. The anomalous intensities in the x-ray diffraction patterns were interpreted as being the result of stacking faults, indicating that the mechanism of transition proceeds by the sliding of {gamma}(111) planes to form {alpha}(001) planes. The increasing transition pressure for more aggregated samples may be due to a positive activation volume, retarding the transition for nanocrystals with less excess (organic) volume available to them. The lack of a reverse transition upon decompression makes this interpretation more difficult because of the lack of an observable hysteresis, and it is therefore difficult to ascertain kinetic effects for certain. In the case TiN/BN nanocomposite systems, it was found that the bulk modulus (B{sub 0}) of the TiN nanoparticles was not correlated to the observed hardness or Young's modulus of the macroscopic thin film. This indicates that the origin of the observed super-hard nature of these materials is not due to any change in the Ti-N interatomic potential. Rather, the enhanced hardness must be due to nano-structural effects. It was also found that during pressurization the TiN nanoparticles developed a great deal of strain. This strain can be related to defects induced in individual nanoparticles which generates strain in adjacent particles due to the highly coupled nature of the system.

  12. Mechanical engineering Department Seminar

    E-Print Network [OSTI]

    Lin, Xi

    Mechanical engineering Department Seminar Ju Li Professor MIT Electrochemical-mechanical actions computational and experimental research on mechanical properties of materials, and energy storage and conversion Refreshments served at 10:45 AM The creation of a nanoscale electrochemical and mechanical testing platform

  13. Physical process Mechanical mechanisms

    E-Print Network [OSTI]

    Berlin,Technische Universität

    1 Physical process Generation · Mechanical mechanisms F = m·a · Electric/Magnetic mechanisms F = B·i·l · Fluid dynamic/Hydraulic mechanisms q, p, ij · Thermal/Optical #12;2 Source unit

  14. COMPLEX MECHANICAL PROPERTIES OF STEEL

    E-Print Network [OSTI]

    Cambridge, University of

    and Metallurgy University of Cambridge Churchill College A dissertation submitted for the degree of Doctor. Bhadeshia in the Department of Materials Science and Metallurgy, University of Cam- bridge, between October from the Department of Materials Sci- ence and Metallurgy, University of Cambridge, especially Mathew

  15. Re Effects on Phase Stability and Mechanical Properties of MoSS+Mo3Si+Mo5SiB2 alloys

    SciTech Connect (OSTI)

    Yang, Ying [ORNL; Bei, Hongbin [ORNL; George, Easo P [ORNL; Tiley, Jaimie [Air Force Research Laboratory, Wright-Patterson AFB, OH

    2013-01-01T23:59:59.000Z

    Because of their high melting points and good oxidation resistance Mo-Si-B alloys are of interest as potential ultrahigh-temperature structural materials. But their major drawbacks are poor ductility and fracture toughness at room temperature. Since alloying with Re has been suggested as a possible solution, we investigate here the effects of Re additions on the microstructure and mechanical properties of a ternary alloy with the composition Mo-12.5Si-8.5B (at.%). This alloy has a three-phase microstructure consisting of Mo solid-solution (MoSS), Mo3Si, and Mo5SiB2 and our results show that up to 8.4 at.% Re can be added to it without changing its microstructure or forming any brittle phase at 1600 C. Three-point bend tests using chevron-notched specimens showed that Re did not improve fracture toughness of the three-phase alloy. Nanoindentation performed on the MoSS phase in the three-phase alloy showed that Re increases Young s modulus, but does not lower hardness as in some Mo solid solution alloys. Based on our thermodynamic calculations and microstructural analyses, the lack of a Re softening effect is attributed to the increased Si levels in the Re-containing MoSS phase since Si is known to increase its hardness. This lack of softening is possibly why there is no Re-induced improvement in fracture toughness.

  16. Improved life of die casting dies of H13 steel by attaining improved mechanical properties and distortion control during heat treatment. Year 1 report, October 1994--September 1995

    SciTech Connect (OSTI)

    Wallace, J.F.; Schwam, D. [Case Western Reserve Univ., Cleveland, OH (United States)

    1995-03-01T23:59:59.000Z

    Optimum heat treatment of dies (quenching) is critical in ensuring satisfactory service performance: rapid cooling rates increase the thermal fatigue/heat checking resistance of the steel, although very fast cooling rates can also lead to distortion and lower fracture toughness, increasing the danger of catastrophic fracture. Goal of this project is to increase die life by using fast enough quenching rates (> 30 F/min ave cooling rate from 1750 to 550 F, 1/2 in. below working surfaces) to obtain good toughness and fatigue resistance in Premium grade H-13 steel dies. An iterative approach of computer modeling validated by experiment was taken. Cooling curves during gas quenching of H-13 blocks and die shapes were measured under 2, 5, and 7.5 bar N2 and 4 bar Ar. Resulting dimensional changes and residual stresses were determined. To facilitate the computer modeling work, a database of H-13 mechanical and physical properties was compiled. Finite element analysis of the heat treated shapes was conducted. Good fit of modeled vs measured quenched rates was demonstrated for simple die shapes. The models predict well the phase transformation products from the quench. There is good fit between predicted and measured distortion contours; however magnitude of predicted distortion and residual stresses does not match well the measured values. Further fine tuning of the model is required.

  17. Effects of thermal annealing on the structural, mechanical, and tribological properties of hard fluorinated carbon films deposited by plasma enhanced chemical vapor deposition

    SciTech Connect (OSTI)

    Maia da Costa, M.E.H.; Baumvol, I.J.R.; Radke, C.; Jacobsohn, L.G.; Zamora, R.R.M.; Freire, F.L. Jr. [Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, Cx. Postal 3807, Rio de Janeiro, RJ, 22453-970 (Brazil); Instituto de Fisica, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, 91540-000 (Brazil); Los Alamos National Laboratory, Materials Science and Technology Division, P. O. Box 1663, Los Alamos, New Mexico 87545 (United States); Departamento de Fisica, Pontificia Universidade Catolica do Rio de Janeiro, Cx. Postal 3807, Rio de Janeiro, RJ, 22453-970 (Brazil)

    2004-11-01T23:59:59.000Z

    Hard amorphous fluorinated carbon films (a-C:F) deposited by plasma enhanced chemical vapor deposition were annealed in vacuum for 30 min in the temperature range of 200-600 deg. C. The structural and compositional modifications were followed by several analytical techniques: Rutherford backscattering spectrometry (RBS), elastic recoil detection analysis (ERDA), x-ray photoelectron spectroscopy (XPS) and Raman spectroscopy. Nanoidentation measurements and lateral force microscopy experiments were carried out in order to provide the film hardness and the friction coefficient, respectively. The internal stress and contact angle were also measured. RBS, ERDA, and XPS results indicate that both fluorine and hydrogen losses occur for annealing temperatures higher than 300 deg. C. Raman spectroscopy shows a progressive graphitization upon annealing, while the surface became slightly more hydrophobic as revealed by the increase of the contact angle. Following the surface wettability reduction, a decrease of the friction coefficient was observed. These results highlight the influence of the capillary condensation on the nanoscale friction. The film hardness and the internal stress are constant up to 300 deg. C and decrease for higher annealing temperatures, showing a direct correlation with the atomic density of the films. Since the thickness variation is negligible, the mass loss upon thermal treatment results in amorphous structures with a lower degree of cross-linking, explaining the deterioration of the mechanical properties of the a-C:F films.

  18. Effect of heat input on the microstructure and mechanical properties of tungsten inert gas arc butt-welded AZ61 magnesium alloy plates

    SciTech Connect (OSTI)

    Min Dong [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Shen Jun, E-mail: shenjun2626@163.com [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China); Lai Shiqiang; Chen Jie [College of Material Science and Engineering, Chongqing University, Chongqing 400044 (China)

    2009-12-15T23:59:59.000Z

    In this paper, the effects of heat input on the microstructures and mechanical properties of tungsten inert gas arc butt-welded AZ61 magnesium alloy plates were investigated by microstructural observations, microhardness tests and tensile tests. The results show that with an increase of the heat input, the grains both in the fusion zone and the heat-affected zone coarsen and the width of the heat-affected zone increased. Moreover, an increase of the heat input resulted in a decrease of the continuous {beta}-Mg{sub 17}Al{sub 12} phase and an increase of the granular {beta}-Mg{sub 17}Al{sub 12} phase in both the fusion zone and the heat-affected zone. The ultimate tensile strength of the welded joint increased with an increase of the heat input, while, too high a heat input resulted in a decrease of the ultimate tensile strength of the welded joint. In addition, the average microhardness of the heat-affected zone and fusion zone decreased sharply with an increase of the heat input and then decreased slowly at a relatively high heat input.

  19. THE INFLUENCE OF RETAINED AUSTENITE ON THE THICK SECTION MECHANICAL PROPERTIES OF A COMMERCIAL LOW ALLOY ULTRA-HIGH STRENGTH STEEL

    E-Print Network [OSTI]

    Horn, R.M.

    2010-01-01T23:59:59.000Z

    of Fracture of High Strength Steels, Final Tech. Report,Arsenal Lab. , K. J. Irvine, Steel Strengthening Mechanisms,Diagrams, United States Steel, Pittsburgh, PA, 1963. E. G.

  20. Ultralight, ultrastiff mechanical metamaterials

    E-Print Network [OSTI]

    Zheng, Xiaoyu

    The mechanical properties of ordinary materials degrade substantially with reduced density because their structural elements bend under applied load. We report a class of microarchitected materials that maintain a nearly ...

  1. Method and apparatus for the evaluation of a depth profile of thermo-mechanical properties of layered and graded materials and coatings

    DOE Patents [OSTI]

    Finot, Marc (Somerville, MA); Kesler, Olivera (Cambridge, MA); Suresh, Subra (Wellesley, MA)

    1998-01-01T23:59:59.000Z

    A technique for determining properties such as Young's modulus, coefficient of thermal expansion, and residual stress of individual layers within a multi-layered sample is presented. The technique involves preparation of a series of samples, each including one additional layer relative to the preceding sample. By comparison of each sample to a preceding sample, properties of the topmost layer can be determined, and residual stress at any depth in each sample, resulting from deposition of the top layer, can be determined.

  2. Influence of material property variability on the mechanical behaviour of carotid atherosclerotic plaques: A 3D fluid-structure interaction analysis

    E-Print Network [OSTI]

    Yuan, Jianmin; Teng, Zhongzhao; Feng, Jiaxuan; Zhang, Yongxue; Brown, Adam J.; Gillard, Jonathan H.; Jing, Zaiping; Lu, Qingsheng

    2015-05-28T23:59:59.000Z

    . Testing of small connective tissue specimens for the determination of the mechanical behaviour of atherosclerotic plaques. Journal of Biomedical Engineering 1993; 15:27–33. 46. Holzapfel GA, Sommer G, Gasser CT, Regitnig P. Determination of layer...

  3. Representation of State Property Systems

    E-Print Network [OSTI]

    Diederik Aerts; Sylvia Pulmannova

    2008-11-15T23:59:59.000Z

    A 'state property system' is the mathematical structure which models an arbitrary physical system by means of its set of states, its set of properties, and a relation of 'actuality of a certain property for a certain state'. We work out a new axiomatization for standard quantum mechanics, starting with the basic notion of state property system, and making use of a generalization of the standard quantum mechanical notion of 'superposition' for state property systems.

  4. Effects of fabrication practices and techniques on the corrosion and mechanical properties of Ni-Cr-Mo nickel based alloys UNS N10276, N06022, N06686, and N06625

    SciTech Connect (OSTI)

    Hinshaw, E.B.; Crum, J.R. [Inco Alloys International, Inc., Huntington, WV (United States)

    1996-11-01T23:59:59.000Z

    Ni-Cr-Mo alloys have excellent resistance to both oxidizing and reducing type environments; however, heat treating, surface condition, welding, and type of welding consumable can have a significant affect on the corrosion resistance and mechanical properties of these alloys. It is also important when performing standard ASTM intergranular corrosion tests on welded test coupons to make an accurate comparison of alloys being tested. A standard weld procedure and consistent post-weld sample conditioning method should be incorporated into the comparison test program. An evaluation of the effect of various fabrication practices on the corrosion resistance of the alloy was performed using accelerated corrosion tests ASTM G28B. The fabrication conditions examined were as-welded, welded-pickled, welded-annealed-pickled, welded annealed ground, welded-ground, using over matching filler metals, and various levels of heat input. In addition to fabrication techniques, the effect of ASTM G28B test duration on corrosion rates of UNS N10276, N06022, N06686, and N06625 was evaluated. ASTM G28A intergranular corrosion and mechanical testing using welded coupons of UNS N06625 were also performed to determine the affect of post-weld annealing and aging heat treatments on the corrosion resistance and mechanical properties of UNS N06625.

  5. periodica polytechnica Mechanical Engineering

    E-Print Network [OSTI]

    Gubicza, Jenõ

    structure. Keywords aluminium alloys · nanostructured materials · mechanical characterization · X-thickness texture gradient produced by the different routes of DSR have been studied in Al 1050 aluminium alloy [15 routes on the microstructure and mechanical properties of Al 7075 aluminium alloy. Microstructure

  6. Method and apparatus for the evaluation of a depth profile of thermo-mechanical properties of layered and graded materials and coatings

    DOE Patents [OSTI]

    Finot, M.; Kesler, O.; Suresh, S.

    1998-12-08T23:59:59.000Z

    A technique for determining properties such as Young`s modulus, coefficient of thermal expansion, and residual stress of individual layers within a multi-layered sample is presented. The technique involves preparation of a series of samples, each including one additional layer relative to the preceding sample. By comparison of each sample to a preceding sample, properties of the topmost layer can be determined, and residual stress at any depth in each sample, resulting from deposition of the top layer, can be determined. 11 figs.

  7. Use of a region of the visible and near infrared spectrum to predict mechanical properties of wet wood and standing trees

    DOE Patents [OSTI]

    Meglen, Robert R. (Boulder, CO); Kelley, Stephen S. (Evergreen, CO)

    2003-01-01T23:59:59.000Z

    In a method for determining the dry mechanical strength for a green wood, the improvement comprising: (a) illuminating a surface of the wood to be determined with a reduced range of wavelengths in the VIS-NIR spectra 400 to 1150 nm, said wood having a green moisture content; (b) analyzing the surface of the wood using a spectrometric method, the method generating a first spectral data of a reduced range of wavelengths in VIS-NIR spectra; and (c) using a multivariate analysis technique to predict the mechanical strength of green wood when dry by comparing the first spectral data with a calibration model, the calibration model comprising a second spectrometric method of spectral data of a reduced range of wavelengths in VIS-NIR spectra obtained from a reference wood having a green moisture content, the second spectral being correlated with a known mechanical strength analytical result obtained from the reference wood when dried and a having a dry moisture content.

  8. CHARACTERIZATION OF MICRO-MECHANICAL PROPERTIES OF GRANULAR MATERIALS BASED ON THE USE OF 3D-T IMAGERY AND DISCRETE ELEMENT MODELING 

    E-Print Network [OSTI]

    Duong, Tam

    2012-05-07T23:59:59.000Z

    conditions by the use of distinct elements using PFC-3D. This allows for a direct comparison to achieving a better understanding on the assessment of micro properties of granular materials. The outcomes of this study also permit to conduct uncertainty...

  9. Study of the growth mechanisms of GaN/(Al, Ga)N quantum dots: Correlation between structural and optical properties

    SciTech Connect (OSTI)

    Sergent, S. [CRHEA-CNRS, Rue Bernard Gregory, Sophia Antipolis, 06560 Valbonne (France); Universite de Nice Sophia Antipolis, Parc Valrose, F-06102 Nice Cedex 2 (France); Damilano, B.; Huault, T.; Brault, J.; Tottereau, O.; Vennegues, P.; Leroux, M.; Semond, F.; Massies, J. [CRHEA-CNRS, Rue Bernard Gregory, Sophia Antipolis, 06560 Valbonne (France); Korytov, M.

    2011-03-01T23:59:59.000Z

    The ammonia-based molecular beam epitaxy of GaN/(Al, Ga)N quantum dots is investigated using reflection high-energy electron diffraction, atomic force microscopy, transmission electron microscopy and photoluminescence. The main steps of the formation kinetics are identified and the influence of diffusion and evaporation processes on both the quantum dot and the wetting layer morphology is addressed. The correlation between the optical and structural properties of such structures finally allows for the analysis of matter exchanges between the quantum dots and the wetting layer during capping.

  10. Mechanical and transparent conductive properties of ZnO and Ga-doped ZnO films sputtered using electron-cyclotron-resonance plasma on polyethylene naphtalate substrates

    SciTech Connect (OSTI)

    Akazawa, Housei, E-mail: akazawa.housei@lab.ntt.co.jp [NTT Microsystem Integration Laboratories 3-1 Morinosato Wakamiya, Atsugi, Kanagawa 243-0198 (Japan)

    2014-03-15T23:59:59.000Z

    Transparent conductive ZnO and Ga-doped ZnO (GZO) films were deposited on polyethylene naphtalate (PEN) sheet substrates using electron cyclotron resonance plasma sputtering. Both ZnO and GZO films were highly adhesive to the PEN substrates without inserting an intermediate layer in the interface. When compared at the same thickness, the transparent conductive properties of GZO films on PEN substrates were only slightly inferior to those on glass substrates. However, the carrier concentration of ZnO films on PEN substrates was 1.5?times that of those on glass substrates, whereas their Hall mobility was only 60% at a thickness of 300?nm. The depth profile of elements measured by secondary ion mass spectroscopy revealed the diffusion of hydrocarbons out of the PEN substrate into the ZnO film. Hence, doped carbons may act as donors to enhance carrier concentration, and the intermixing of elements at the interface may deteriorate the crystallinity, resulting in the lower Hall mobility. When the ZnO films were thicker than 400?nm, cracks became prevalent because of the lattice mismatch strain between the film and the substrate, whereas GZO films were free of cracks. The authors investigated how rolling the films around a cylindrical pipe surface affected their conductive properties. Degraded conductivity occurred at a threshold pipe radius of 10?mm when tensile stress was applied to the film, but it occurred at a pipe radius of 5?mm when compressive stress was applied. These values are guidelines for bending actual devices fabricated on PEN substrates.

  11. Spatially resolved energy dispersive x-ray spectroscopic method for in-situ evaluation of mechanical properties during the growth of a C - Pt composite nanowire

    SciTech Connect (OSTI)

    Banerjee, Amit; Banerjee, S. S., E-mail: satyajit@iitk.ac.in [Department of Physics, Indian Institute of Technology Kanpur, Kanpur, 208016 (India)

    2014-05-15T23:59:59.000Z

    A core-shell type C-Pt composite nanowire is fabricated using focused ion and electron beam induced chemical vapor deposition techniques. Using information from spatially resolved energy dispersive x-ray spectra, we detect the resonance vibration in the C-Pt composite nanowire. We use this method to measure the Young's moduli of the constituents (C, Pt) of the composite nanowire and also estimate the density of the FEB CVD grown Pt shell surrounding the C core. By measuring the resonance characteristics of the composite nanowire we estimate a Pt shell growth rate of ?0.9 nms{sup ?1}. The study is analyzed to suggest that the Pt shell growth mechanism is primarily governed by the sticking coefficient of the organometallic vapor on the C nanowire core.

  12. Influence of boron on the microstructural and mechanical properties of Ni{sub 53.5}Mn{sub 26.0}Ga{sub 20.5} shape memory alloy

    SciTech Connect (OSTI)

    Ramudu, M., E-mail: macrams2@gmail.com; Kumar, A. Satish, E-mail: macrams2@gmail.com; Seshubai, V., E-mail: macrams2@gmail.com [School of Physics, University of Hyderabad, Central University P. O., Hyderabad - 500 046 (India); Rajasekharan, T. [Department of Physics, Rajiv Gandhi University of Knowledge Technologies, IIIT-Campus, Gachibowli, Hyderabad - 500 032 (India)

    2014-04-24T23:59:59.000Z

    Boron addition to Ni{sub 53.5}Mn{sub 26.0}Ga{sub 20.5} alloy is found to modify the microstructure and mechanical properties substantially. Studies on (Ni{sub 53.5}Mn{sub 26.0}Ga{sub 20.5})B{sub x} alloys reveal that boron addition causes grain refinement which led to an increase in compressive strength in x=0.5 alloy which also retained multimode twinning. Substantial second phase segregation rich in Ni was seen at grain boundaries, the extent of which increased with boron content. This led to a compositional shift in the matrix phase which resulted in a reduction in the martensitic transformation temperature and which in turn caused an easy deformation at low stresses and suppression of multimode twinning in x=1.0 alloy.

  13. Determining the mechanical constitutive properties of metals as a function of strain rate and temperature: A combined experimental and modeling approach; Progress Report for 2004

    SciTech Connect (OSTI)

    I. Robertson; A. Beaudoin; J. Lambros

    2005-01-31T23:59:59.000Z

    Development and validation of constitutive models for polycrystalline materials subjected to high strain rate loading over a range of temperatures are needed to predict the response of engineering materials to in-service type conditions (foreign object damage, high-strain rate forging, high-speed sheet forming, deformation behavior during forming, response to extreme conditions, etc.). To account accurately for the complex effects that can occur during extreme and variable loading conditions, requires significant and detailed computational and modeling efforts. These efforts must be closely coupled with precise and targeted experimental measurements that not only verify the predictions of the models, but also provide input about the fundamental processes responsible for the macroscopic response. Achieving this coupling between modeling and experimentation is the guiding principle of this program. Specifically, this program seeks to bridge the length scale between discrete dislocation interactions with grain boundaries and continuum models for polycrystalline plasticity. Achieving this goal requires incorporating these complex dislocation-interface interactions into the well-defined behavior of single crystals. Despite the widespread study of metal plasticity, this aspect is not well understood for simple loading conditions, let alone extreme ones. Our experimental approach includes determining the high-strain rate response as a function of strain and temperature with post-mortem characterization of the microstructure, quasi-static testing of pre-deformed material, and direct observation of the dislocation behavior during reloading by using the in situ transmission electron microscope deformation technique. These experiments will provide the basis for development and validation of physically-based constitutive models, which will include dislocation-grain boundary interactions for polycrystalline systems. One aspect of the program will involve the direct observation of specific mechanisms of micro-plasticity, as these will indicate the boundary value problem that should be addressed. This focus on the pre-yield region in the quasi-static effort (the elasto-plastic transition) is also a tractable one from an experimental and modeling viewpoint. In addition, our approach will minimize the need to fit model parameters to experimental data to obtain convergence. These are critical steps to reach the primary objective of simulating and modeling material performance under extreme loading conditions. To achieve these goals required assembling a multidisciplinary team, see Table 1, with key collaborators at the National Laboratories. One of the major issues for the team members was to learn about the expertise available and how to communicate across disciplines. The communication issue is a challenging one and is being addressed in part with weekly meetings in which the graduate students present lectures on the fundamentals of their respective areas to the entire group. Breakthroughs in science are presented but these, by necessity, assume a tutorial nature; examples of student led meetings can be found at our website http://hrdg.mse.uiuc.edu/. For example, interpreting electron micrographs and understanding what can be achieved by using electron microscopy is challenging for the modeling expert as is comprehending the input and limitations of crystal plasticity codes for an electron microscopist. Significant progress has been made at dissolving these barriers and the students are able to work across the disciplines.

  14. Deformation of shale: mechanical properties and indicators of mechanisms

    E-Print Network [OSTI]

    Ibanez, William Dayan

    1993-01-01T23:59:59.000Z

    Basins, shales of Devonian age are commonly considered reservoir rocks I' or natural gas [Woodward, 1958; Lockett, 1968; Long, 1979; Gonzales and Johnson, 1985], Economic gas production from the Devonian shales of these basins is associated...] and slates [Donath, 1961], may be expected to be weak. Finally, Microstructural studies of deformed shales have been restricted by optical resolution, and the role of crystal plasticity in clays may have been overlooked. Results for the brittle and semi...

  15. Thermoelectric properties of n-type Bi{sub 2}(Te{sub 1{minus}x}Se{sub x}){sub 3} fabricated by mechanical alloying and hot pressing

    SciTech Connect (OSTI)

    Kim, H.J.; Choi, J.S.; Oh, T.S.; Hyun, D.B.

    1997-07-01T23:59:59.000Z

    Thermoelectric properties of polycrystalline Bi{sub 2}(Te{sub 1{minus}x}Se{sub x}){sub 3} (0.05 {le} x {le} 0.25), fabricated by mechanical alloying and hot pressing, have been investigated. Formation of n-type Bi{sub 2}(Te{sub 0.9}Se{sub 0.1}){sub 3} alloy powders was completed by mechanical alloying for 3 hours at ball-to-material ratio of 5:1, and processing time for Bi{sub 2}(Te{sub 1{minus}x}Se{sub x}){sub 3} formation increased with Bi{sub 2}Se{sub 3} content x. Figure-of-merit of Bi{sub 2}(Te{sub 0.9}Se{sub 0.1}) was markedly increased by hot pressing at temperatures above 450 C, and maximum value of 1.9 x 10{sup {minus}3}/K was obtained by hot pressing at 550 C. With addition of 0.015 wt% Bi as acceptor dopant, figure-of-merit of Bi{sub 2}(Te{sub 0.9}Se{sub 0.1}){sub 3} was hot pressed at 550 C, could be improved to 2.1 x 10{sup {minus}3}/K. When Bi{sub 2}(Te{sub 1{minus}x}Se{sub x}){sub 3} was hot pressed at 550 C, figure-of-merit increased from 1.14 x 10{sup {minus}3}/K to 1.92 x 10{sup {minus}3}/K with increasing Bi{sub 2}Se{sub 3} content x from 0.05 to 0.15, and then decreased to 1.30 x 10{sup {minus}3}/K for x = 0.25 composition.

  16. & Mechanical Engineering

    E-Print Network [OSTI]

    Zhou, Chongwu

    , robotics, and the development of new tools for integrated approaches to concurrent engineeringAME Aerospace & Mechanical Engineering #12;Aerospace and Mechanical Engineers design complex Engineering (AME) students conduct basic and applied research within and across the usual disciplinary

  17. Mechanical properties of radial truck tires

    E-Print Network [OSTI]

    Wasti, Mansoor-ul-Hassan

    1992-01-01T23:59:59.000Z

    (right) 12 13 15 Figure 7: Sidewall bulge measurement 16 Figure 8: Load vs. deflection; 385/65R22. 5 wide base tire tested at 90 psi inflation pressure 20 Figure 9: Load vs. deflection; 385/65R22. 5 wide base tire tested at 100 psi inflation... pressure 21 Figure 10: Load vs. deflection; 385/65R22. 5 wide base tire tested at 110 Psl Figure 11: Load vs, deflection; 385/65R22. 5 wide base tire tested at 120 psi inflation pressure Figure 12: Stiffness vs. load; 385/65R22. 5 wide base tire 22...

  18. Mechanical property measurement by indentation techniques

    E-Print Network [OSTI]

    Janakiraman, Balasubramanian

    2006-04-12T23:59:59.000Z

    optic sensing technique is developed. An incident light beam from a semiconductor laser is coupled back into an optical fiber upon reflection from the metal surface. By measuring the diffused light power reflected from the metal surface, the diameter...

  19. Mechanical Evaluation of Electronic Properties of Materials

    E-Print Network [OSTI]

    Nudo, Nicholas

    2011-05-02T23:59:59.000Z

    Wang, Dr. Subrata Kundu, Dr. Feng Gao, Dr. Gang Liang, Rodrigo Cooper, David Huitink, Michael Chiu, Brady Barkley, and Sukbae Joo. viii NOMENCLATURE Au Gold C Carbon Pd Palladium PVDF Polyvinylidene fluoride XPS X-ray photoelectron...

  20. Electrical and Mechanical Properties of Graphene

    E-Print Network [OSTI]

    Bao, Wenzhong

    2011-01-01T23:59:59.000Z

    another method to exfoliate relative large graphene flakes,graphene devices, we exfoliate graphene sheets on standardfabrication process. We first exfoliate graphene sheets on

  1. Mechanical properties of insulators for Accelerator Magnets

    E-Print Network [OSTI]

    McDonald, Kirk

    ­ ~Mylar, glass fibre, epoxy resin ­ ~2mm thick · NbTi Superconducting Magnets ­ ~Kapton & epoxy ­ ~40µm thick · Nb3Sn Superconducting Magnets ­ ~S-glass fibre, epoxy resin, cyanate ester ­ ~400µm thick 3 #12 with epoxy resin 4 Useful to recap glass fibre/polymer composites #12;Glass fibre/epoxy composites 5 ·A

  2. Electrical and Mechanical Properties of Graphene

    E-Print Network [OSTI]

    Bao, Wenzhong

    2011-01-01T23:59:59.000Z

    Transport in a Suspended Graphene Sheet, Phys. Rev. Lett. ,Novoselov, The rise of graphene, Nat. Mater. , 6 (2007) [24]mobility in suspended graphene, Sol. State Commun. , 146 (

  3. MECHANICAL PROPERTIES OF POROUS PNZT POLYCRYSTALLINE CERAMICS

    E-Print Network [OSTI]

    Biswas, D.R.

    2010-01-01T23:59:59.000Z

    in Two-Phase Brittle-Matrix Ceramic Composites," Ibid. , R.ceramic. Spherical pores (110-150ym diameter) were introduced by using The matrix

  4. Master thesis Model for Mechanical Properties

    E-Print Network [OSTI]

    Cambridge, University of

    of Ferrous Technology (Computational Metallurgy) Graduate Institute of Ferrous Technology Pohang University-Rolled Steels By Ryu, Joo Hyun Department of Ferrous Technology (Computational Metallurgy) Graduate Institute of Science in the Graduate Institute of Ferrous Technology (Computational Metallurgy) Pohang, Korea December

  5. Mechanical property measurement by indentation techniques 

    E-Print Network [OSTI]

    Janakiraman, Balasubramanian

    2006-04-12T23:59:59.000Z

    optic sensing technique is developed. An incident light beam from a semiconductor laser is coupled back into an optical fiber upon reflection from the metal surface. By measuring the diffused light power reflected from the metal surface, the diameter...

  6. Mechanical Properties of Materials for Fusion Power

    E-Print Network [OSTI]

    Cambridge, University of

    by a cooling system. Their kinetic energy is transformed into heat and electricity via steam turbines other university. This dissertation does not exceed 60,000 words in length. Some of the work described

  7. Fundamental Properties and Processes of Energetic Materials

    E-Print Network [OSTI]

    Ojeda Mota, Oscar Ulises

    2012-10-19T23:59:59.000Z

    frequencies, conformational rearrangement and mechanical properties can be calculated within the density functional theory and molecular dynamics at finite temperatures. We have found marked differences in the calculated properties in systems with ranging...

  8. Property Tax Exemption for Wind Generators

    Broader source: Energy.gov [DOE]

    Manufacturing facilities (broadly defined as “facilities engaged in the mechanical or chemical transformation of materials or substances into new products”) are eligible for the property tax exem...

  9. Biomineralized structural materials with functional optical properties

    E-Print Network [OSTI]

    Li, Ling, Ph. D. Massachusetts Institute of Technology

    2014-01-01T23:59:59.000Z

    Many biological structural materials exhibit "mechanical property amplification" through their intricate hierarchical composite designs. In the past several decades, significant progress has been achieved in elucidating ...

  10. Alcohol CVD growth of single-walled carbon nanotubes and their optical properties Shigeo Maruyama, maruyama@photon.t.u-tokyo.ac.jp, Department of Mechanical Engineering, The University of Tokyo, 7-3-1 Hongo,

    E-Print Network [OSTI]

    Maruyama, Shigeo

    of single-walled carbon nanotubes and their optical properties 2007/02/24http://oasys2.confex.com/acs/232nm

  11. Computational mechanics

    SciTech Connect (OSTI)

    Goudreau, G.L.

    1993-03-01T23:59:59.000Z

    The Computational Mechanics thrust area sponsors research into the underlying solid, structural and fluid mechanics and heat transfer necessary for the development of state-of-the-art general purpose computational software. The scale of computational capability spans office workstations, departmental computer servers, and Cray-class supercomputers. The DYNA, NIKE, and TOPAZ codes have achieved world fame through our broad collaborators program, in addition to their strong support of on-going Lawrence Livermore National Laboratory (LLNL) programs. Several technology transfer initiatives have been based on these established codes, teaming LLNL analysts and researchers with counterparts in industry, extending code capability to specific industrial interests of casting, metalforming, and automobile crash dynamics. The next-generation solid/structural mechanics code, ParaDyn, is targeted toward massively parallel computers, which will extend performance from gigaflop to teraflop power. Our work for FY-92 is described in the following eight articles: (1) Solution Strategies: New Approaches for Strongly Nonlinear Quasistatic Problems Using DYNA3D; (2) Enhanced Enforcement of Mechanical Contact: The Method of Augmented Lagrangians; (3) ParaDyn: New Generation Solid/Structural Mechanics Codes for Massively Parallel Processors; (4) Composite Damage Modeling; (5) HYDRA: A Parallel/Vector Flow Solver for Three-Dimensional, Transient, Incompressible Viscous How; (6) Development and Testing of the TRIM3D Radiation Heat Transfer Code; (7) A Methodology for Calculating the Seismic Response of Critical Structures; and (8) Reinforced Concrete Damage Modeling.

  12. Computational mechanics

    SciTech Connect (OSTI)

    Raboin, P J

    1998-01-01T23:59:59.000Z

    The Computational Mechanics thrust area is a vital and growing facet of the Mechanical Engineering Department at Lawrence Livermore National Laboratory (LLNL). This work supports the development of computational analysis tools in the areas of structural mechanics and heat transfer. Over 75 analysts depend on thrust area-supported software running on a variety of computing platforms to meet the demands of LLNL programs. Interactions with the Department of Defense (DOD) High Performance Computing and Modernization Program and the Defense Special Weapons Agency are of special importance as they support our ParaDyn project in its development of new parallel capabilities for DYNA3D. Working with DOD customers has been invaluable to driving this technology in directions mutually beneficial to the Department of Energy. Other projects associated with the Computational Mechanics thrust area include work with the Partnership for a New Generation Vehicle (PNGV) for ''Springback Predictability'' and with the Federal Aviation Administration (FAA) for the ''Development of Methodologies for Evaluating Containment and Mitigation of Uncontained Engine Debris.'' In this report for FY-97, there are five articles detailing three code development activities and two projects that synthesized new code capabilities with new analytic research in damage/failure and biomechanics. The article this year are: (1) Energy- and Momentum-Conserving Rigid-Body Contact for NIKE3D and DYNA3D; (2) Computational Modeling of Prosthetics: A New Approach to Implant Design; (3) Characterization of Laser-Induced Mechanical Failure Damage of Optical Components; (4) Parallel Algorithm Research for Solid Mechanics Applications Using Finite Element Analysis; and (5) An Accurate One-Step Elasto-Plasticity Algorithm for Shell Elements in DYNA3D.

  13. J. Sulem, P. Lazar, I. Vardoulakis (2007): Thermo-Poro-Mechanical Properties of Clayey Gouge and Application to Rapid Fault Shearing, Int. J. Numer. Anal. Meth. Geomech., 2007; 31:523540.

    E-Print Network [OSTI]

    Boyer, Edmond

    and temperature increase leading to pore fluid vaporization. Published in: Int. J. Numer. Anal. Meth. Geomech circulating fluids and fault mechanics with particular focus on the hydro-thermo-mechanical couplings has been renewed in the geophysics community during the recent years. Active fault drilling operations

  14. Qualitative insights on fundamental mechanics

    E-Print Network [OSTI]

    G. N. Mardari

    2006-11-10T23:59:59.000Z

    The gap between classical mechanics and quantum mechanics has an important interpretive implication: the Universe must have an irreducible fundamental level, which determines the properties of matter at higher levels of organization. We show that the main parameters of any fundamental model must be theory-independent. They cannot be predicted, because they cannot have internal causes. However, it is possible to describe them in the language of classical mechanics. We invoke philosophical reasons in favor of a specific model, which treats particles as sources of real waves. Experimental considerations for gravitational, electromagnetic, and quantum phenomena are outlined.

  15. Evolution of Frictional Behavior of Punchbowl Fault Gouges Sheared at Seismic Slip Rates and Mechanical and Hydraulic Properties of Nankai Trough Accretionary Prism Sediments Deformed at Different Loading Paths 

    E-Print Network [OSTI]

    Kitajima, Hiroko

    2012-02-14T23:59:59.000Z

    Frictional measurements were made on natural fault gouge at seismic slip rates using a high-speed rotary-shear apparatus to study effects of slip velocity, acceleration, displacement, normal stress, and water content. Thermal-, mechanical...

  16. Evolution of Frictional Behavior of Punchbowl Fault Gouges Sheared at Seismic Slip Rates and Mechanical and Hydraulic Properties of Nankai Trough Accretionary Prism Sediments Deformed at Different Loading Paths

    E-Print Network [OSTI]

    Kitajima, Hiroko

    2012-02-14T23:59:59.000Z

    of frictional heating, mechanical behavior, and microstructure evolution? by Hiroko Kitajima, Judith S. Chester, Frederick M. Chester, and Toshihiko Shimamoto, 2010. Journal of Geophysical Research, 115, B08408, doi:10.1029/2009JB0 07038, Copyright 2010...

  17. Aspects of the mechanics of metallic glasses

    E-Print Network [OSTI]

    Henann, David Lee

    2011-01-01T23:59:59.000Z

    Metallic glasses are amorphous materials that possess unique mechanical properties, such as high tensile strengths and good fracture toughnesses. Also, since they are amorphous, metallic glasses exhibit a glass transition, ...

  18. PRELIMINARY REPORT ON GEOPHYSICAL AND MECHANICAL BOREHOLE MEASUREMENTS AT STRIPA

    E-Print Network [OSTI]

    Nelson, P.

    2011-01-01T23:59:59.000Z

    mechanical properties of granite, Stripa, Sweden. TR 77-92.Measurements in the Stripa Granite. Berkeley Laboratoryof Groundwaters in the Stripa Granite: Lawrence Berkeley

  19. Key Physical Mechanisms in Nanostructured Solar Cells

    SciTech Connect (OSTI)

    Dr Stephan Bremner

    2010-07-21T23:59:59.000Z

    The objective of the project was to study both theoretically and experimentally the excitation, recombination and transport properties required for nanostructured solar cells to deliver energy conversion efficiencies well in excess of conventional limits. These objectives were met by concentrating on three key areas, namely, investigation of physical mechanisms present in nanostructured solar cells, characterization of loss mechanisms in nanostructured solar cells and determining the properties required of nanostructured solar cells in order to achieve high efficiency and the design implications.

  20. Hydrogen Properties

    Broader source: Energy.gov [DOE]

    The atomic structure, physical and chemical properties, flammability and safety, fundamental gas laws, how pressure, temperature and mass flow are measured

  1. Personal Property

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2014-10-16T23:59:59.000Z

    This Guide provides non-regulatory guidance and information to assist DOE organizations and contractors in implementing the DOE-wide and site-specific personal property management programs. It supplements the policy, requirements, and responsibilities information contained in the DOE Order cited above and clarifies the regulatory requirements contained in the Federal Property Management Regulation (FMR) and specific contracts.

  2. 8.333 Statistical Mechanics I: Statistical Mechanics of Particles, Fall 2007

    E-Print Network [OSTI]

    Kardar, Mehran

    Statistical Mechanics is a probabilistic approach to equilibrium properties of large numbers of degrees of freedom. In this two-semester course, basic principles are examined. Topics include: thermodynamics, probability ...

  3. 8.333 Statistical Mechanics I: Statistical Mechanics of Particles, Fall 2005

    E-Print Network [OSTI]

    Kardar, Mehran

    Statistical Mechanics is a probabilistic approach to equilibrium properties of large numbers of degrees of freedom. In this two-semester course, basic principles are examined. Topics include: thermodynamics, probability ...

  4. Nanocrystalline alloys : enhanced strengthening mechanisms and mechanically-driven structural evolution

    E-Print Network [OSTI]

    Rupert, Timothy J. (Timothy John)

    2011-01-01T23:59:59.000Z

    Nanocrystalline materials have experienced a great deal of attention in recent years, largely due to their impressive array of physical properties. In particular, nanocrystalline mechanical behavior has been of interest, ...

  5. Model to predict the mechanical behaviour of oriented rigid PVC

    E-Print Network [OSTI]

    Miroshnychenko, Dmitri

    Model to predict the mechanical behaviour of oriented rigid PVC D. J. Hitt*1 and D. Miroshnychenko2 The mechanical properties of PVC sheets can be modified substantially by both uniaxial and biaxial stretching pattern in the relationship between tensile properties of oriented PVC products and imposed strains

  6. abrasive wear properties: Topics by E-print Network

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    and Dissertations Summary: ??The mechanical properties and wear behaviour of B(SiC) fibre-reinforced metal matrix composites (MMCs) and aluminium alloy (2014) produced by...

  7. Mechanics of Isolated Horizons

    E-Print Network [OSTI]

    Abhay Ashtekar; Christopher Beetle; Stephen Fairhurst

    1999-11-04T23:59:59.000Z

    A set of boundary conditions defining an undistorted, non-rotating isolated horizon are specified in general relativity. A space-time representing a black hole which is itself in equilibrium but whose exterior contains radiation admits such a horizon. However, the definition is applicable in a more general context, such as cosmological horizons. Physically motivated, (quasi-)local definitions of the mass and surface gravity of an isolated horizon are introduced and their properties analyzed. Although their definitions do not refer to infinity, these quantities assume their standard values in the static black hole solutions. Finally, using these definitions, the zeroth and first laws of black hole mechanics are established for isolated horizons.

  8. Interfacial Properties of Electron Beam Cured Composites

    SciTech Connect (OSTI)

    Eberle, C.C.

    1999-12-30T23:59:59.000Z

    The objectives of the CRADA are to: Confirm that fiber-resin adhesion is responsible for the observed poor shear properties; Determine the mechanism(s) responsible for poor adhesion between carbon fibers and epoxy resins after e-beam curing; Develop and evaluate resin systems and fiber treatments to improve the properties of e-beam cured, carbon-fiber-reinforced composites; and Develop refined methods for processing e-beam cured, carbon-fiber-reinforced composites.

  9. Characterizing motion contour detection mechanisms and equivalent mechanisms in the luminance domain

    E-Print Network [OSTI]

    Zanker, Johannes M.

    Characterizing motion contour detection mechanisms and equivalent mechanisms in the luminance with sparsely defined luminance Gabor patterns and found similar results, but only at low sampling densities. The nature of the information and the strength of the signal influence the properties of luminance contour

  10. Mechanical instability at finite temperature

    E-Print Network [OSTI]

    Xiaoming Mao; Anton Souslov; Carlos I. Mendoza; T. C. Lubensky

    2014-07-08T23:59:59.000Z

    Many physical systems including lattices near structural phase transitions, glasses, jammed solids, and bio-polymer gels have coordination numbers that place them at the edge of mechanical instability. Their properties are determined by an interplay between soft mechanical modes and thermal fluctuations. In this paper we investigate a simple square-lattice model with a $\\phi^4$ potential between next-nearest-neighbor sites whose quadratic coefficient $\\kappa$ can be tuned from positive negative. We show that its zero-temperature ground state for $\\kappa power-law behavior of the shear modulus as a function of temperature. We expect our study to provide a general framework for the study of finite-temperature mechanical and phase behavior of other systems with a large number of floppy modes.

  11. The application of high-resolution 3D seismic data to model the distribution of mechanical and hydrogeological properties of a potential host rock for the deep storage of radioactive waste in France

    E-Print Network [OSTI]

    Mari, Jean-Luc

    2014-01-01T23:59:59.000Z

    In the context of a deep geological repository of high-level radioactive wastes, the French National Radioactive Waste Management Agency (Andra) has conducted an extensive characterization of the Callovo-Oxfordian argillaceous rock and surrounding formations in the Eastern Paris Basin. As part of this project, an accurate 3D seismic derived geological model is needed. The paper shows the procedure used for building the 3D seismic constrained geological model in depth by combining time-to-depth conversion of seismic horizons, consistent seismic velocity model and elastic impedance in time. It also shows how the 3D model is used for mechanical and hydrogeological studies. The 3D seismic field data example illustrates the potential of the proposed depth conversion procedure for estimating density and velocity distributions, which are consistent with the depth conversion of seismic horizons using the Bayesian Kriging method. The geological model shows good agreement with well log data obtained from a reference we...

  12. Heavy Mobile Equipment Mechanic (One Mechanic Shop)

    Broader source: Energy.gov [DOE]

    The position is a Heavy Mobile Equipment Mechanic (One Mechanic Shop) located in Kent, Washington, and will be responsible for the safe and efficient operation of a field garage performing...

  13. PROPERTY MANUAL Berkeley Laboratory Property Management

    E-Print Network [OSTI]

    Knowles, David William

    of Energy (DOE). The Property Management charter ensures the efficient and effective protection and controlPROPERTY MANUAL Issued by Berkeley Laboratory Property Management Lawrence Berkeley National of Property Management Policies · I. Parties and Organizations Responsible for Property · II. Acquiring

  14. Mechanical & Industrial Engineering

    E-Print Network [OSTI]

    Mountziaris, T. J.

    Mechanical & Industrial Engineering 1 Welcome MIE Industrial Advisory Board October 15, 2010 #12;Mechanical & Industrial Engineering 2 MIE Dorothy Adams Undergraduate/Graduate Secretary David Schmidt Associate Professor & Graduate Program Director #12;Mechanical & Industrial Engineering 3 MIE James Rinderle

  15. Mechanical Engineering & Thermal Group

    E-Print Network [OSTI]

    Mojzsis, Stephen J.

    Mechanical Engineering & Thermal Group The Mechanical Engineering (ME) & Thermal Group at LASP has · STOP (Structural, Thermal, and Optical Performance) analyses of optical systems Thermal engineers lead evolved with the complexity of instrument design demands, LASP mechanical engineers develop advanced

  16. Mechanical engineering Department Seminar

    E-Print Network [OSTI]

    and the Department of Mechanical Engineering Tufts University Retooling Our Energy Ecosystem: challengesMechanical engineering Department Seminar Robert J. Hannemann The Gordon Institute and Chair of the Tufts Department of Mechanical Engineering. His technical and academic interests

  17. Theoretical Modeling of Mechanical-Electrical Coupling of Carbon Nanotubes

    SciTech Connect (OSTI)

    Lu, Jun-Qiang [ORNL; Jiang, Hanqiang [Arizona State University

    2008-01-01T23:59:59.000Z

    Carbon nanotubes have been studied extensively due to their unique properties, ranging from electrical, mechanical, optical, to thermal properties. The coupling between the electrical and mechanical properties of carbon nanotubes has emerged as a new field, which raises both interesting fundamental problems and huge application potentials. In this article, we will review our recently work on the theoretical modeling on mechanical-electrical coupling of carbon nanotubes subject to various loading conditions, including tension/compression, torsion, and squashing. Some related work by other groups will be also mentioned.

  18. Mechanical & Aerospace Engineering

    E-Print Network [OSTI]

    Mechanical & Aerospace Engineering It is a new beginning for innovative fundamental and applied and consolidation of bulk nanocrystalline materials using mechanical alloying, the alloy development and synthesis

  19. Combined Quantum Mechanical and Molecular Mechanics Studies of...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mechanical and Molecular Mechanics Studies of the Electron-Transfer Reactions Involving Carbon Tetrachloride in Combined Quantum Mechanical and Molecular Mechanics Studies of the...

  20. Mechanically Robust and Bioadhesive Collagen and Photocrosslinkable Hyaluronic Acid Semi-Interpenetrating Networks

    E-Print Network [OSTI]

    Brigham, Mark D.

    In this work, we present a class of hydrogels that leverage the favorable properties of the photo-cross-linkable hyaluronic acid (HA) and semi-interpenetrating collagen components. The mechanical properties of the ...

  1. Mechanics of Atherosclerosis, Hypertension Induced Growth, and Arterial Remodeling

    E-Print Network [OSTI]

    Hayenga, Heather Naomi

    2012-07-16T23:59:59.000Z

    In order to create informed predictive models that capture artery dependent responses during atherosclerosis progression and the long term response to hypertension, one needs to know the structural, biochemical and mechanical properties as a...

  2. The structure and mechanics of nanofibrillar cellulose foams

    E-Print Network [OSTI]

    Ali, Zubaidah Mohammed

    Crystalline nanofibrillar cellulose has remarkable mechanical properties: a Young's modulus of about 130 GPa and a tensile strength in the range of 750–1000 MPa. Recently, there has been increasing interest in exploiting ...

  3. Mechanics of Atherosclerosis, Hypertension Induced Growth, and Arterial Remodeling 

    E-Print Network [OSTI]

    Hayenga, Heather Naomi

    2012-07-16T23:59:59.000Z

    In order to create informed predictive models that capture artery dependent responses during atherosclerosis progression and the long term response to hypertension, one needs to know the structural, biochemical and mechanical properties as a...

  4. Continuum models of deformation mechanisms in nanocrystalline metals

    E-Print Network [OSTI]

    Jérusalem, Antoine, 1979-

    2007-01-01T23:59:59.000Z

    Nanocrystalline metals are polycrystalline metals with grain sizes in the nanometer range. They have attracted significant interest in recent years due to their unique mechanical and electrical properties. The main objective ...

  5. Nanocomposite Thin Films for both Mechanical and Functional Applications

    E-Print Network [OSTI]

    Zhang, Sam

    The design methodology and realization of nanocomposite films aiming for mechanical (superhardness, toughness) and functional (optical, microelectronic) properties were discussed in this paper. Superhard TiCrCN and ...

  6. Mechanics of Notched Izod impact testing of polycarbonate

    E-Print Network [OSTI]

    Silberstein, Meredith N

    2005-01-01T23:59:59.000Z

    Polycarbonate is widely used as a transparent protective material because of its low density and excellent mechanical properties. However, when defects such as cracks or notches are introduced, it is subject to catastrophic ...

  7. In Situ Small Scale Mechanical Characterization of Materials Under Environmental 

    E-Print Network [OSTI]

    Sanders, Matthew Wayne

    2011-10-21T23:59:59.000Z

    , aluminum and titanium alloys were examined using those two techniques. Analysis of their behavior in comparison with their published mechanical properties made it possible to establish connections between test parameters and conventional uniaxial tensile...

  8. Mechanics of deformation of carbon nanotube-polymer nanocomposites

    E-Print Network [OSTI]

    Akiskalos, Theodoros, 1978-

    2004-01-01T23:59:59.000Z

    The goal is to develop finite element techniques to evaluate the mechanical behavior of carbon nanotube enabled composites and gain a thorough understanding of the parameters that affect the properties of the composite, ...

  9. Toward the assessment of mechanical robustness of ceramic multilayer capacitors (MLCs)

    SciTech Connect (OSTI)

    Wereszczak, A.A.; Breder, K.; Riester, L.; Kirkland, T.P.; Bridge, R.J.

    2000-02-01T23:59:59.000Z

    The present study consisted of two efforts: the measurement of several mechanical properties of dielectric ceramics in MLCs and the consideration of what effects other parameters have on MLC mechanical reliability or robustness.

  10. Building robust chemical reaction mechanisms : next generation of automatic model construction software

    E-Print Network [OSTI]

    Song, Jing, 1972-

    2004-01-01T23:59:59.000Z

    Building proper reaction mechanisms is crucial to model the system dynamic properties for many industrial processes with complex chemical reaction phenomena. Because of the complexity of a reaction mechanism, computer-aided ...

  11. Mechanical behavior of tissue simulants and soft tissues under extreme loading conditions

    E-Print Network [OSTI]

    Kalcioglu, Zeynep Ilke

    2013-01-01T23:59:59.000Z

    Recent developments in computer-integrated surgery and in tissue-engineered constructs necessitate advances in experimental and analytical techniques in characterizing properties of mechanically compliant materials such ...

  12. Internal pipe attachment mechanism

    DOE Patents [OSTI]

    Bast, R.M.; Chesnut, D.A.; Henning, C.D.; Lennon, J.P.; Pastrnak, J.W.; Smith, J.A.

    1994-12-13T23:59:59.000Z

    An attachment mechanism is described for repairing or extending fluid carrying pipes, casings, conduits, etc. utilizing one-way motion of spring tempered fingers to provide a mechanical connection between the attachment mechanism and the pipe. The spring tempered fingers flex to permit insertion into a pipe to a desired insertion depth. The mechanical connection is accomplished by reversing the insertion motion and the mechanical leverage in the fingers forces them outwardly against the inner wall of the pipe. A seal is generated by crushing a sealing assembly by the action of setting the mechanical connection. 6 figures.

  13. Mechanical properties of two canine iliac fracture fixation systems 

    E-Print Network [OSTI]

    VanGundy, Thomas Eugene

    1988-01-01T23:59:59.000Z

    Group-Un- paired specimens tested as intact bones Intact T-Torsion E, -Axial E, -Axial and moderate bending E~-Axial and maximum bending 3 In all implant specimens a standardized oblique iliac fracture was simulated by osteotomy with a... the neutral longitudinal axis of the specimen at the rate of 15 degrees per minute. Axial loading was performed along the neutral longitudinal axis (E, position in Fig. 5). Axial loading with a concurrent bending moment (modes E~ and E~ in Fig. 5...

  14. Microstructural and Mechanical Property Changes in Ion Irradiated Tunsgten

    E-Print Network [OSTI]

    General, Michael

    2013-04-08T23:59:59.000Z

    Sustainable fusion power is within reach; however, more research is needed in the field of material science and engineering. One critical component of a fusion reactor is the plasma facing material. Very little literature exists...

  15. Mechanical Property and Hydrogen Sorption in Mg Based Nanolayers 

    E-Print Network [OSTI]

    Ham, Byoungsoo

    2013-11-18T23:59:59.000Z

    Wang for their guidance and support throughout the course of this research. I also thank Dr. Wang for the use of her laboratory facilities. I wish to thank my collaborators from Anchalee Junkeaw from Dr. Arroyave’s group, Dr. Yang Ren from Argonne... and Dr. Mohammad A. Omary from University of North Texas for the experimental help. I want to thank former Zhang research group members, Drs. Osman Anderoglu, Engang Fu, and Nan Li for their guidance as I began my graduate school career. I also want...

  16. Mechanical Properties of Ultrananocrystalline Diamond Thin Films for MEMS Applications

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    such as microturbines have already been produced. These preliminary exercises are promising steps toward full

  17. Mechanical properties of normotensive and hypertensive female rat carotid arteries

    E-Print Network [OSTI]

    Smith, Katherine Elizabeth

    2002-01-01T23:59:59.000Z

    drawing of the layers of the arterial wall (IM, an A denote iniima, media, and adventitia, respectively); B. Cross-sectional muscular artery histology (The Elebrew University of Jerusalem, 1997) Tortuous inner layer is the internal elastic lamina, which... divides the intima and the media. The darker middle layer with circumferentially oriented smooth muscle cells is the media, and lighter outer layer is the adventitia. d This thesis follows the style and format of Journal of Biomechanics. constantly...

  18. Modelling of Mechanical Properties of Ferritic Weld Metals

    E-Print Network [OSTI]

    Lalam, Sree Harsha

    2000-12-05T23:59:59.000Z

    #6;K\\H^]_Q`LWN#19;BZKaHZKMb`L#19;KMKcQ`]edcQgfhN#6;Q`LiQ`]kjWBIDGlGQTF#6;Q`mEBon#4;OPNpN#19;BZKcqaSIDRr`KMLJFJDRNsn Q`]#17;tiO`[#17;YILJDGHIb`K`u#15;ACBZKvL#19;K\\F#6;K\\OPLJfwB#8;HIK\\F#19;fhLJDRYxK\\HyBZKMLJK\\DGSyziO`F{fhQTSIHIXIfhN#6;K\\H#8;XISIHZKML... |N#19;BZKvFJXZmxKML#19;r}DVF#19;DRQTS~Q`] j#21;LJQ`]K\\F#19;F#19;Q`LC?uI?^uId#4;uI?#17;uI?iBIO`HZK\\F#19;BIDVO#4;DVS|N#19;BIK?dcKMm OPL#19;N#19;[^K\\SoNCQ`]#23;?vOPN#6;KMLJDGO`lGFa?gfMDRK\\SIfhK3O`SIH&?=KMN#19;O`lGlGXZLJb`n`? qaSIDRr`KMLJF#19;DGNsn?Q`]?ti...

  19. Influence of defects on thermal and mechanical properties of metals

    E-Print Network [OSTI]

    Kamani, Sandeep Kumar

    2009-05-15T23:59:59.000Z

    SDen ..................................... 33 13 Copper with 8 interstitials at 1600K ....................................................... 34 14 Temperature Vs time for copper without defects at 1360K .................... 39 15 Potential energy Vs time for copper without defects... at 1360K .............. 40 16 Total energy Vs time for copper without defects at 1360K .................... 40 17 Average volume Vs temperature for pure copper without defects .......... 41 18 Total energy Vs temperature for copper without defects...

  20. Mechanical properties of collagen-based scaffolds for tissue regeneration

    E-Print Network [OSTI]

    Kanungo, Biraja Prasad, 1980-

    2009-01-01T23:59:59.000Z

    Collagen-glycosaminoglycan (CG) scaffolds for the regeneration of skin and nerve have previously been fabricated by freeze-drying a slurry containing a co-precipitate of collagen and glycosaminoglycan. Recently, mineralized ...

  1. Mechanical and Electrical Properties of Modified Graphene Devices

    E-Print Network [OSTI]

    ZHANG, HANG

    2012-01-01T23:59:59.000Z

    in detail sample (graphene) preparation, localization and20 3.1 Sample (graphene) preparation, localization and3.2. 3.1 Sample (graphene) preparation, localization and

  2. Investigation into mechanical properties of bone and its main constituents

    E-Print Network [OSTI]

    Evdokimenko, Ekaterina

    2012-01-01T23:59:59.000Z

    A review,” Materials Science and Engineering C, 30, 331-temperatures,” Materials Science and Engineering C, 31, 523-materials,” Materials Science and Engineering C, 31 (4),

  3. An evaluation of the critical mechanical properties of filled elastomers

    E-Print Network [OSTI]

    Gibson, Patrick Arthur

    1966-01-01T23:59:59.000Z

    Failure Data ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ i ~ ~ ~ 31 DISCUSSION OP NESDLTS 5. 1 General ~ ~ ~ t ~ ~ ~ ~ e 5. 2 Initial Modulus and Strain 5 ~ 3 Fiona s ~ ~ ~ ~ ~ ~ ~ ~ 5. 4 Failure Criteria ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ Energy...

  4. Predicting Wear From Mechanical Properties of Thermoplastic Polymers

    E-Print Network [OSTI]

    North Texas, University of

    : poly(methylmethacrylate) (PMMA, RTP Company), polyphenylsulfone (Solvay Advanced Poly- mers, L.L.C.), and polyvinylidene fluoride (PVDF, Solvay Solexis, Inc.). Other polymers were polystyrene (PS, Aldrich Chemicals

  5. Mechanical properties and fabric of the Punchbowl fault zone, California 

    E-Print Network [OSTI]

    Chester, Frederick Michael

    1983-01-01T23:59:59.000Z

    faults (DP10C) used in the Compression Tests. 88 22 Specimen configuration for Compression Tests. . 89 23 Specimen configuration for Shear Tests, . 92 LIST OF FIGURES (continued) FIGURE PAGE 24 Differential stress versus axial strai n... the motivation for establishing a program of earthquake-risk evaluation and prediction. One approach to earthquake-prediction (mechanistic approach of Higgs, 1 981 ) involves developing a sound understandi ng of the physical processes operative within...

  6. Mechanical properties of two canine iliac fracture fixation systems

    E-Print Network [OSTI]

    VanGundy, Thomas Eugene

    1988-01-01T23:59:59.000Z

    and mediolateral dimensions of the iliac shaft of each specimen were measured with calipers and the cross-sectional area approximated as the height times the width. Group mean cross sectional area was compared using the nonpaired t-test for control versus... Group-Un- paired specimens tested as intact bones Intact T-Torsion E, -Axial E, -Axial and moderate bending E~-Axial and maximum bending 3 In all implant specimens a standardized oblique iliac fracture was simulated by osteotomy with a...

  7. Nanoscale Structures Relating to the Mechanical Properties of Abalone Shell

    E-Print Network [OSTI]

    Petta, Jason

    of Nacre 1. The nacreous layer of sea-shells is composed of 95 vol.% CaCO3, and 5% organic matrix (proteins of magnitude higher than monolithic CaCO3. The fracture toughness is comparable to that of modern ceramics. #12 Orthorhombic form of CaCO3 #12;Cross-section view of Abalone Shell Figures 1a and 1b: SEM Images of cross

  8. Microfluidic devices for analysis of red blood cell mechanical properties

    E-Print Network [OSTI]

    Bow, Hansen Chang

    2010-01-01T23:59:59.000Z

    Decreased deformability of human red blood cells (RBCs) is both a cause of disease and biomarker for disease (1). To traverse blood capillaries, the biconcave disk-shaped RBC must deform dramatically, since the diameter ...

  9. Mechanical Properties of a Metal Powder-Loaded Polyurethane Foam

    SciTech Connect (OSTI)

    C. L. Neuschwanger; L. L. Whinnery; S. H. Goods

    1999-04-01T23:59:59.000Z

    Quasi-static compression tests have been performed on polyurethane foam specimens. The modulus of the foam exhibited a power-law dependence with respect to density of the form: E* {proportional_to} {rho}*{sup n}, where n = 1.7. The modulus data is well described by a simple geometric model (attributed to the work of Gibson and Ashby) for closed-cell foam in which the stiffness of the foam is governed by the flexure of the cell struts and cell walls. The compressive strength of the foam is also found to follow a power-law behavior with respect to foam density. In this instance, Euler buckling is used to rationalize the density dependence. The modulus of the polyurethane foam was modified by addition of a gas atomized, spherical aluminum powder. Additions of 30 and 50 weight percent of the powder significantly increased the foam modulus. However, there were only slight increases in modulus with 5 and 10 weight percent additions of the metal powder. Strength was also slightly increased at high loading fractions of powder. This increase in modulus and strength could be predicted by combining the above geometric model with a well-known model describing the effect on modulus of a rigid dispersoid in a compliant matrix.

  10. Mechanical properties of an extruded pyramidal lattice truss sandwich structure

    E-Print Network [OSTI]

    Wadley, Haydn

    rows. Conventional joining methods such as brazing or laser welding are then used to bond the core methods such as adhesive bonding, brazing, diffusion bonding and welding. Recently, lattice truss

  11. Mechanical Property and Hydrogen Sorption in Mg Based Nanolayers

    E-Print Network [OSTI]

    Ham, Byoungsoo

    2013-11-18T23:59:59.000Z

    ), nanocrystalline MgH2 +5 at.%V composite (b), and backscattered electron image of nanocrystalline MgH2 +5 at.%V composite (c) where the white marks represent vanadium particles... COMPOSITES. ............... 53 III.1 Overview .......................................................................................................... 53 III.2 Introduction...

  12. Mechanical Properties of Alkali Resistant Glass Fabric Composites

    E-Print Network [OSTI]

    Mobasher, Barzin

    of research experience in civil engineering materials. He is a member of American Concrete Institute University. She is an independent consultant for Stealth Management Group, LLC focusing on construction, planning and development of hotels and other commercial projects. Corina-Maria Aldea is senior materials

  13. Mechanical Properties of Ferrofluid Applications: Centering Effect and Capacity

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    of ironless loudspeakers [8]-[12]. Electromagnetic pumps are designed and studied for the processing industry made out of permanent magnets 2 hal-00392784,version1-9Jun2009 #12;(the stator) or non magnetic

  14. Investigation into mechanical properties of bone and its main constituents

    E-Print Network [OSTI]

    Evdokimenko, Ekaterina

    2012-01-01T23:59:59.000Z

    during the progression of osteoporosis will help to clarifyfor prevention and cure of osteoporosis in the future.D, Rosen, CJ. (Eds. ), Osteoporosis, 3rd ed. Elsevier, Inc,

  15. MECHANICAL PROPERTY-MICROSTRUCTURAL RELATIONSHIPS IN ABALONE SHELL*

    E-Print Network [OSTI]

    Aksay, Ilhan A.

    of component phases (e.g., metal and ceramic matrix composites); and (iii) tape casting and infiltration (e MPa-m"1 2 ; these values are comparablewith or better than most "high technology" ceramic materials such as cermet (ceramic-metal) and cerpoly (ceramic-polymer) composites. INTRODUCTION In the quest to develop

  16. Reconstruction of Sedimentary Rock Based on Mechanical Properties

    E-Print Network [OSTI]

    Jin, Guodong; Patzek, Tad W.; Silin, Dmitry B.

    2008-01-01T23:59:59.000Z

    Journal of Sedimentary Petrology 47, 3 (1977). [48] ITASCA,E. G. Ehlers and H. Blatt, Petrology: igneous, sedimen- taryT. Maurice, Sedimentary Petrology - an introduction to the

  17. Mechanical properties of materials for fusion power plants

    E-Print Network [OSTI]

    Forsik, Stéphane Alexis Jacques

    encouragements et sa patience en toute circonstance. iii Abstract Fusion power is the production of electricity from a hot plasma of deuterium and tritium, reacting to produce ? particles and 14 MeV neutrons, which are collected by a cooling system. Their kinetic... –induced plasticity wppm Weight parts–per–million vii Nomenclature Chapter 2 at% Atomic percentage D Deuterieum eV Electron–volt Z AM Metallic atom with a mass number Z and an atomic number A n Neutron T Tritium wt% Weight percentage ? Alpha particle (helium ion...

  18. RIS-M-2230 THERMAL AND MECHANICAL PROPERTIES OF NITROGEN

    E-Print Network [OSTI]

    viscosity Liquid enthalpy density heat capacity - conductivity dynamic viscosity Surface tension Conven Temperature Pressure Latent heat of evaporation Gas enthalpy density - heat capacity conductivity - dynamic of nitrogen liquid and gas (1 to 6 bar) are presented. The approximations are polynomials worked out

  19. Mechanical Properties of Structural Steels in Hydrogen | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels DataDepartment of Energy Your Density Isn't YourTransport(FactDepartment3311, 3312), October 20122Technologies |MeasurementsEnergy

  20. 1. Department, Course Number, Title ORE 607 Water Wave Mechanics

    E-Print Network [OSTI]

    Frandsen, Jannette B.

    kinematics, dynamics, propagation, transformation, and statistical properties of water waves. 3. Ability1. Department, Course Number, Title ORE 607 Water Wave Mechanics 2. Designation as a Required://chl.erdc.usace.army.mil). 2. Water Wave Mechanics for Engineers and Scientists, by R.G. Dean and R.A. Dalrymple, World

  1. Graduate School Engineering Mechanics

    E-Print Network [OSTI]

    Franssen, Michael

    Mechanics c/o Eindhoven University of Technology PO Box 513, building W-hoog 2.113 5600 MB Eindhoven NL Tel on Engineering Mechanics, a joint initiative of the Eindhoven and Delft Universities of Technology Mechanics c/o Eindhoven University of Technology PO Box 513, building W-hoog 2.113 5600 MB Eindhoven NL

  2. Mechanical & Industrial Engineering

    E-Print Network [OSTI]

    Mountziaris, T. J.

    Mechanical & Industrial Engineering Mario A. Rotea Professor and Department Head #12;2Mechanical & Industrial Engineering Outline · Undergraduate Degree Programs · Graduate Degree Programs · The Faculty · The Research · Summary #12;3Mechanical & Industrial Engineering Undergraduate Programs ­ BSME & BSIE 0 20 40 60

  3. UNSATURATED SOIL MECHANICS IMPLEMENTATION

    E-Print Network [OSTI]

    Minnesota, University of

    UNSATURATED SOIL MECHANICS IMPLEMENTATION DURING PAVEMENT CONSTRUCTION QUALITY ASSURANCE Mn !! Performance Based Construction QA !! Unsaturated Soil Mechanics !! What We've Learned !! Next Steps #12.6-6.0 5 - 7 19 0.8 5 7 - 9 24 1.1 4 9 - 11 28 1.2 4 #12;Unsaturated Soil Mechanics #12;Fundamentals

  4. Mechanical & Aerospace Engineering

    E-Print Network [OSTI]

    Mechanical & Aerospace Engineering An experimental methodology is presented for mechanism Yang is a second graduate student in the department of mechanical engineering of ASU. He received his Jian Yang School for Engineering of Matter, Transport and Energy Arizona State University October 5

  5. Mechanical engineering Department Seminar

    E-Print Network [OSTI]

    efficient energy systems. Evelyn N. Wang is an Associate Professor in the Mechanical Engineering DepartmentMechanical engineering Department Seminar Evelyn Wang Depaprtment of Mechanical Engineering MIT Nanoengineered Surfaces: Transport Phenomena and Energy Applications 11:00 AM Friday, 5 April 2013 Room 245, 110

  6. Mechanical engineering Department Seminar

    E-Print Network [OSTI]

    Mechanical engineering Department Seminar Domitilla Del Vecchio Department of Mechanical. A near future is envisioned in which re- engineered bacteria will turn waste into energy and kill cancer, she joined the Department of Mechanical Engineering and the Laboratory for Information and Decision

  7. Mechanical & Aerospace Engineering

    E-Print Network [OSTI]

    in Mechanical Engineering at the School for Engineering of Matter, Transport and Energy, working in Dr. MarcusMechanical & Aerospace Engineering The atomization of a liquid jet by a high speed cross.S.E. degree in mechanical engineering from Amirkabir University of Technology in 2006 and M.S. degree

  8. Hydro-mechanical modelling of geological CO2 storage and the study of possible caprock fracture mechanisms

    E-Print Network [OSTI]

    element modelling of a hypothetical underground carbon dioxide (CO2) storage operation. The hydro-mechanical properties of the materials modelled are chosen to be representative of a potential injection site. For high on the injection process, and on site and rock properties. Rutqvist et al. (2008) showed through a coupled

  9. DNA Twist Elasticity: Mechanics and Thermal Fluctuations

    E-Print Network [OSTI]

    Supurna Sinha; Joseph Samuel

    2010-11-30T23:59:59.000Z

    The elastic properties of semiflexible polymers are of great importance in biology. There are experiments on biopolymers like double stranded DNA, which twist and stretch single molecules to probe their elastic properties. It is known that thermal fluctuations play an important role in determining molecular elastic properties, but a full theoretical treatment of the problem of twist elasticity of fluctuating ribbons using the simplest worm like chain model (WLC) remains elusive. In this paper, we approach this problem by taking first a mechanical approach and then incorporating thermal effects in a quadratic approximation applying the Gelfand-Yaglom (GY) method for computing fluctuation determinants. Our study interpolates between mechanics and statistical mechanics in a controlled way and shows how profoundly thermal fluctuations affect the elasticity of semiflexible polymers. The new results contained here are: 1) a detailed study of the minimum energy configurations with explicit expressions for their energy and writhe and plots of the extension versus Link for these configurations. 2) a study of fluctuations around the local minima of energy and approximate analytical formulae for the free energy of stretched twisted polymers derived by the Gelfand Yaglom method. We use insights derived from our mechanical approach to suggest calculational schemes that lead to an improved treatment of thermal fluctuations. From the derived formulae, predictions of the WLC model for molecular elasticity can be worked out for comparison against numerical simulations and experiments.

  10. Mechanical seal assembly

    DOE Patents [OSTI]

    Kotlyar, Oleg M. (Salt Lake City, UT)

    2001-01-01T23:59:59.000Z

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transferring it to the mechanical diode.

  11. Mechanical seal assembly

    DOE Patents [OSTI]

    Kotlyar, Oleg M. (Salt Lake City, UT)

    2002-01-01T23:59:59.000Z

    An improved mechanical seal assembly is provided for sealing rotating shafts with respect to their shaft housings, wherein the rotating shafts are subject to substantial axial vibrations. The mechanical seal assembly generally includes a rotating sealing ring fixed to the shaft, a non-rotating sealing ring adjacent to and in close contact with the rotating sealing ring for forming an annular seal about the shaft, and a mechanical diode element that applies a biasing force to the non-rotating sealing ring by means of hemispherical joint. The alignment of the mechanical diode with respect to the sealing rings is maintained by a series of linear bearings positioned axially along a desired length of the mechanical diode. Alternative embodiments include mechanical or hydraulic amplification components for amplifying axial displacement of the non-rotating sealing ring and transfering it to the mechanical diode.

  12. General coarse-grained red blood cell models: I. Mechanics

    E-Print Network [OSTI]

    Fedosov, Dmitry A; Karniadakis, George E

    2009-01-01T23:59:59.000Z

    We present a rigorous procedure to derive coarse-grained red blood cell (RBC) models, which lead to accurate mechanical properties of realistic RBCs. Based on a semi-analytic theory linear and non-linear elastic properties of the RBC membrane can be matched with those obtained in optical tweezers stretching experiments. In addition, we develop a nearly stress-free model which avoids a number of pitfalls of existing RBC models, such as non-biconcave equilibrium shape and dependence of RBC mechanical properties on the triangulation quality. The proposed RBC model is suitable for use in many existing numerical methods, such as Lattice Boltzmann, Multiparticle Collision Dynamics, Immersed Boundary, etc.

  13. General coarse-grained red blood cell models: I. Mechanics

    E-Print Network [OSTI]

    Dmitry A. Fedosov; Bruce Caswell; George E. Karniadakis

    2009-05-01T23:59:59.000Z

    We present a rigorous procedure to derive coarse-grained red blood cell (RBC) models, which lead to accurate mechanical properties of realistic RBCs. Based on a semi-analytic theory linear and non-linear elastic properties of the RBC membrane can be matched with those obtained in optical tweezers stretching experiments. In addition, we develop a nearly stress-free model which avoids a number of pitfalls of existing RBC models, such as non-biconcave equilibrium shape and dependence of RBC mechanical properties on the triangulation quality. The proposed RBC model is suitable for use in many existing numerical methods, such as Lattice Boltzmann, Multiparticle Collision Dynamics, Immersed Boundary, etc.

  14. ROCK PROPERTIES AND THEIR EFFECT ON THERMALLY-INDUCED DISPLACEMENTS AND STRESSES

    E-Print Network [OSTI]

    Chan, T.

    2010-01-01T23:59:59.000Z

    Mechanical Properties of Granite, Stripa, Sweden," Terra TekHeating Experiments in Granite," presented at 1979 Fallthe CSM Cell in Swedish Granite," Proc. 20th U. S. Symp.

  15. Development of Electrospun Tissue Engineering Scaffolds with Tunable Properties

    E-Print Network [OSTI]

    Nezarati, Roya M

    2014-07-12T23:59:59.000Z

    have developed methods to tune scaffold mechanical properties and bioactivity through modulation of electrospun mesh microarchitecture and in situ gelatin crosslinking. First, we developed methods to improve mesh reproducibility by investigating...

  16. Accelerated Characterization of Polymer Properties

    SciTech Connect (OSTI)

    R. Wroczynski; l. Brewer; D. Buckley; M. Burrell; R. Potyrailo

    2003-07-30T23:59:59.000Z

    This report describes the efforts to develop a suite of microanalysis techniques that can rapidly measure a variety of polymer properties of industrial importance, including thermal, photo-oxidative, and color stability; as well as ductility, viscosity, and mechanical and antistatic properties. Additional goals of the project were to direct the development of these techniques toward simultaneous measurements of multiple polymer samples of small size in real time using non-destructive and/or parallel or rapid sequential measurements, to develop microcompounding techniques for preparing polymers with additives, and to demonstrate that samples prepared in the microcompounder could be analyzed directly or used in rapid off-line measurements. These enabling technologies are the crucial precursors to the development of high-throughput screening (HTS) methodologies for the polymer additives industry whereby the rate of development of new additives and polymer formulations can be greatly accelerated.

  17. Mechanical engineering Department Seminar

    E-Print Network [OSTI]

    Lin, Xi

    operating in microfluidic environment, which can dynamically diverge, collimate and focus surface plasmons in 2012, with a joint appointment in the Department of Mechanical & Industrial Engineering

  18. Mechanical engineering Department Seminar

    E-Print Network [OSTI]

    Research Center. Currently he is an Assistant Prof. in the Aerospace and Ocean Engineering DepartmentMechanical engineering Department Seminar Cornel Sultan Virginia Tech Design for Control

  19. Fundamental mechanisms in flue-gas conditioning

    SciTech Connect (OSTI)

    Dahlin, R.S.; Vann Bush, P.; Snyder, T.R.

    1992-01-09T23:59:59.000Z

    The overall goal of this research project is to formulate a mathematical model of flue gas conditioning. This model will be based on an understanding of why ash properties, such as cohesivity and resistivity, are changed by conditioning. Such a model could serve as a component of the performance models of particulate control devices where flue gas conditioning is used. There are two specific objectives of this research project, which divide the planned research into two main parts. One part of the project is designed to determine how ash particles are modified by interactions with sorbent injection processes and to describe the mechanisms by which these interactions affect fine particle collection. The objective of the other part of the project is to identify the mechanisms by which conditioning agents, including chemically active compounds, modify the key properties of fine fly ash particles.

  20. Mechanical engineering Department Seminar

    E-Print Network [OSTI]

    properties of NPs and those of nanocar- bon, but also additional novel properties due to the electronic interaction between the NP and the nanocarbon. Such hybrid nanostructures are promising for various technological applications, such as sensors, photovoltaic cells, lithium-ion batteries, supercapacitors, fuel

  1. ME 354 MECHANICS OF MATERIALS LABORATORY MECHANICAL PROPERTIES AND PERFORMANCE OF MATERIALS

    E-Print Network [OSTI]

    Sniadecki, Nathan J.

    of acrylic and polycarbonate measured during a previous lab. Based on the single-edge notch tests conducted (KIc) of polycarbonate and acrylic using the single edge-notch specimen geometry for long and short. a. Acrylic (Short Crack): 3-5 mm b. Acrylic (Long Crack): 7-10 mm c. Polycarbonate (Short Crack): 3

  2. ME 354 MECHANICS OF MATERIALS LABORATORY MECHANICAL PROPERTIES AND PERFORMANCE OF MATERIALS

    E-Print Network [OSTI]

    Sniadecki, Nathan J.

    to conduct tests in the order shown after exposure to the preconditions to give the approximate test is also dependent on the rate at which the force is applied. For example, a polycarbonate tensile specimen

  3. Mechanical Properties, Thermal Stability and Radiation Damage of Ferritic Steels Processed by Thermal Mechanical Treatments

    E-Print Network [OSTI]

    Song, Miao

    2014-08-04T23:59:59.000Z

    Loss Spectroscopy FIM Field Ion Microscopy fcc or FCC Face Centered Cubic viii FFTF Fast Flux Test Facility FIB Focused Ion Beam F/M Ferritic/Martensitic GB Grain Boundary GFR Gas Fast Reactors GNB Geometry Necessary...

  4. Mechanical Properties, Thermal Stability and Radiation Damage of Ferritic Steels Processed by Thermal Mechanical Treatments 

    E-Print Network [OSTI]

    Song, Miao

    2014-08-04T23:59:59.000Z

    friendly choice by the reactors operating today for half century. Lessons have been learned during the operation of generation I-III reactors. To avoid an unanticipated failure, high performance structural materials still represent a crucial component...

  5. Centre for Computational Structural and Materials Mechanics Overall mechanical properties of polysilicon films

    E-Print Network [OSTI]

    -induced failure of polysilicon MEMS: a multi-scale approach. Sensors, 9, pp. 556-567, 2009. 5. S. Mariani, R

  6. ME 354 MECHANICS OF MATERIALS LABORATORY MECHANICAL PROPERTIES AND PERFORMANCE OF MATERIALS

    E-Print Network [OSTI]

    Sniadecki, Nathan J.

    (KIc) of polycarbonate and acrylic using the single edge-notch specimen geometry for long and short. a. Acrylic (Short Crack): 3-5 mm b. Acrylic (Long Crack): 7-10 mm c. Polycarbonate (Short Crack): 3-5 mm d. Polycarbonate (Long Crack): 7-10 mm (b) Measure the gage width w, gage thickness t, and notch

  7. Mechanical Properties of Zeolitic Metal-Organic Frameworks: Mechanically Flexible Topologies and Stabilization against Structural Collapse

    E-Print Network [OSTI]

    Bennett, T.D.; Sotelo, J.; Tan, J.C.; Moggach, S.A.

    2014-11-14T23:59:59.000Z

    , Phys. Rev. Lett., 2012, 108, 095502. 13. T. D. Bennett, J. C. Tan, S. A. Moggach, R. Galvelis, C. Mellot- Draznieks, B. A. Reisner, A. Thirumurugan, D. R. Allan and A. K. Cheetham, Chem.-Eur. J., 2010, 16, 10684-10690. 14. F. X. Coudert, Phys Chem... . J. T. Hughes, T. D. Bennett, A. K. Cheetham and A. Nayrotsky, J. Am. Chem. Soc., 2013, 135, 598-601. 29. Y. H. Hu and L. Zhang, Phys. Rev. B., 2010, 81. 30. A. J. Graham, D. R. Allan, A. Muszkiewicz, C. A. Morrison and S. A. Moggach, Angew. Chem...

  8. Assessing the mechanical microstructure of shale by nanoindentation : the link between mineral composition and mechanical properties

    E-Print Network [OSTI]

    Bobko, Christopher Philip, 1981-

    2008-01-01T23:59:59.000Z

    Shale is a multi-phase, multi-scale sedimentary rock that makes up 75% of the earth's sedimentary basins and is especially critical in petroleum engineering applications. At macroscopic scales, shales possess a diverse set ...

  9. Molecular Mechanism of Biological Proton Transport

    SciTech Connect (OSTI)

    Pomes, R.

    1998-09-01T23:59:59.000Z

    Proton transport across lipid membranes is a fundamental aspect of biological energy transduction (metabolism). This function is mediated by a Grotthuss mechanism involving proton hopping along hydrogen-bonded networks embedded in membrane-spanning proteins. Using molecular simulations, the authors have explored the structural, dynamic, and thermodynamic properties giving rise to long-range proton translocation in hydrogen-bonded networks involving water molecules, or water wires, which are emerging as ubiquitous H{sup +}-transport devices in biological systems.

  10. MECHANICAL ENGINEERING Program of Study

    E-Print Network [OSTI]

    Thomas, Andrew

    offers graduate programs in the fields of thermal science and engineering mechanics. Current areasMECHANICAL ENGINEERING Program of Study Correspondence The Department of Mechanical Engineering of research activity include Biomedical Engineering, Biomimetics, Composite Materials, Computational Mechanics

  11. Yale University Mechanical Engineering

    E-Print Network [OSTI]

    Dollar, Aaron M.

    ) ­ #92474A029 (4x) #12;OpenHand Yale University Mechanical Engineering 3D Printer Requirements · Current · Majority of parts are designed to not require support material · Authors do not know how well alternate 3D printers will produce adequate components #12;OpenHand Yale University Mechanical Engineering Finger

  12. Respiratory Mechanisms of Support

    E-Print Network [OSTI]

    Kay, Mark A.

    Respiratory Mechanisms of Support Nasal Cannula Hi Flow Nasal Cannula CPAP Continuous positive the respiratory system is working to compensate for a metabolic issue so as to normalize the blood pH. HCO3 - 22 uses PIP Mechanical Ventilation: Volume vs. Pressure: Volume Control Pressure Control Cycle Volume Time

  13. Department of Mechanical Engineering

    E-Print Network [OSTI]

    Srivastava, Kumar Vaibhav

    Explore and understand applicable science Create new materials #12;Indian Railways #12;Wheel Impact Load automated system for On-Line estimation of Wheel Impact Loads and detection of Wheel Flats of running trains Detection System (WILD) #12;Derailment Mechanism Laboratory Tests Lab Brake Mechanism Placement of Sensors

  14. Mechanical engineering Department Seminar

    E-Print Network [OSTI]

    Lin, Xi

    Mechanical engineering Department Seminar Junjie Niu Postdoctoral Associate MIT Engineering Nano nanomaterials in applications of energy storage, biomedicine and chemo-mechanics. In 2007, Dr.Niu received young-structured Materials for Energy Storage 11:00 AM Friday, 14 February 2014 Room 245, 110 Cummington Mall Refreshments

  15. Mechanical and Aerospace Engineering

    E-Print Network [OSTI]

    Mechanical and Aerospace Engineering Abstract Solid materials used in energy conversion and storage Department of Civil & Environmental Engineering, Department of Mechanical Engineering, Northwestern University April 6, 2012 at 2:00pm in SCOB 252 School for Engineering of Matter, Transport & Energy #12;

  16. Mechanical & Aerospace Engineering

    E-Print Network [OSTI]

    Mechanical & Aerospace Engineering The development of high-energy storage devices has been one energy capacity over 500 cycles. Teng Ma received his BS degree in Thermal and Power Engineering from Xi and Technology of China in 2009. He is currently a Ph.D. candidate in Mechanical Engineering at School

  17. Mechanical code comparator

    DOE Patents [OSTI]

    Peter, Frank J. (Albuquerque, NM); Dalton, Larry J. (Bernalillo, NM); Plummer, David W. (Albuquerque, NM)

    2002-01-01T23:59:59.000Z

    A new class of mechanical code comparators is described which have broad potential for application in safety, surety, and security applications. These devices can be implemented as micro-scale electromechanical systems that isolate a secure or otherwise controlled device until an access code is entered. This access code is converted into a series of mechanical inputs to the mechanical code comparator, which compares the access code to a pre-input combination, entered previously into the mechanical code comparator by an operator at the system security control point. These devices provide extremely high levels of robust security. Being totally mechanical in operation, an access control system properly based on such devices cannot be circumvented by software attack alone.

  18. BEE 3650. Properties of Biological Materials Spring Semester 2009

    E-Print Network [OSTI]

    Walter, M.Todd

    ", in setting up the team lab project experiment and the associated specialized materials testing associatedBEE 3650. Properties of Biological Materials Spring Semester 2009 J A Bartsch, PE, 05/22/2009 Credit: 3 hours Catalogue description: Mechanics and structural properties of biological materials

  19. BEE 365. Properties of Biological Materials Spring Semester 2007

    E-Print Network [OSTI]

    Walter, M.Todd

    ", in setting up the team lab project experiment and the associated specialized materials testing associatedBEE 365. Properties of Biological Materials Spring Semester 2007 J A Bartsch, PE, 06/28/2007 Credit: 3 hours Catalogue description: Mechanics and structural properties of biological materials

  20. Dynamic Behavior and Microstructural Properties of Cancellous Bone.

    E-Print Network [OSTI]

    Boyer, Edmond

    A total of 15 distal parts of bovine femoral bones were used for this study (72 hours post mortemDynamic Behavior and Microstructural Properties of Cancellous Bone. S. Laporte1 , F. David1 , V of the cancellous bone and to identify the link between this mechanical behavior and the microstructural properties

  1. Intrinsic elastic properties of Calcium Silicate Hydrates by nanoindentation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Understanding the mechanical properties of concrete is one of the main purpose of the science of cement [1,2]. This is not a straightforward question as concrete is a complex heterogeneous material and its properties depend on its measurements on porous samples? Only Surface Force Microscopy is able to carry out indentation at a nanoscopic

  2. 07SCHOOL OF MECHANICAL ENGINEERING

    E-Print Network [OSTI]

    Dimitrova, Vania

    07SCHOOL OF MECHANICAL ENGINEERING UNDERGRADUATE DEGREES School of Mechanical Engineering FACULTY OF ENGINEERING Undergraduate Degrees 2015 #12;www.engineering.leeds.ac.uk/mechanical UNDERGRADUATE DEGREES SCHOOL OF MECHANICAL ENGINEERING The School of Mechanical Engineering offers both a broad mechanical engineering degree

  3. Probing the Intrinsic Properties of Exfoliated Graphene: Raman

    E-Print Network [OSTI]

    Heinz, Tony F.

    Probing the Intrinsic Properties of Exfoliated Graphene: Raman Spectroscopy of Free-standing graphene monolayers prepared by mechanical exfoliation of graphite are investigated. The graphene,7 or to solubilize macroscopic quantities of graphene,8 mechanical exfoliation of graphite9 currently remains

  4. Mechanical enhancement of woven composites with radially aligned carbon nanotubes (CNTs) : investigation of Mode I fracture toughness

    E-Print Network [OSTI]

    Wicks, Sunny S

    2010-01-01T23:59:59.000Z

    Composites have seen an increasing role in aerospace structures that demand lightweight, strong, and stiff materials. Composites are attractive structural materials with outstanding mechanical and physical properties, as ...

  5. Catalytic properties, densification and mechanical properties of nanocrystalline yttria-zirconia-based materials

    E-Print Network [OSTI]

    Cui, Jianyi

    2007-01-01T23:59:59.000Z

    Alumina, titania, ceria and manganese oxide were either coated onto or doped in cubic 7 mol% Y203-ZrO2 (7YZ) nanocrystals to form nanocomposites for methane combustion. These novel catalysts were very active and thermally ...

  6. Thermo-mechanical structure beneath the young orogenic belt of Taiwan

    E-Print Network [OSTI]

    Ma, Kuo-Fong

    Thermo-mechanical structure beneath the young orogenic belt of Taiwan Kuo-Fong Ma*, Teh-Ru Alex Abstract We investigate the thermo-mechanical properties beneath the young orogenic belt of Taiwan.V. All rights reserved. Keywords: Thermo-mechanical; Rheology; Seismicity; Strength profile; Composition

  7. Accepted Manuscript Numerical Characterization of Thermo-mechanical Performance of Breeder

    E-Print Network [OSTI]

    Abdou, Mohamed

    -mechanical properties, mathematical and computational method. #12;ACCEPTED MANUSCRIPT 3 1. Introduction Ceramic breeder Mechanical & Aerospace Engineering Department, UCLA, Los Angeles, CA 90095-1597 Tel: (310) 794-4452 Fax: (310, and Mohamed Abdou Mechanical and Aerospace Engineering Dept., UCLA, Los Angeles, CA 90095-1597, USA an

  8. Mechanics of graded wrinkling

    E-Print Network [OSTI]

    Raayai Ardakani, Shabnam

    2013-01-01T23:59:59.000Z

    The properties of a surface depend on the inherent material and the surface topography. Nature uses surface texture as a means to impact different surface behavior such as cleanliness, adhesion control, drag reduction, ...

  9. Mechanizing Exploratory Game Design

    E-Print Network [OSTI]

    Smith, Adam Marshall

    2012-01-01T23:59:59.000Z

    318 17.1 Multiple, linked grid maps generated from a onlyto the edge of an n-by-n grid map must be covered in water (properties of the large grid map (an n-by-m network) could

  10. Electronic door locking mechanism

    DOE Patents [OSTI]

    Williams, G.L.; Kirby, P.G.

    1997-10-21T23:59:59.000Z

    The invention is a motorized linkage for engaging a thumb piece in a door mechanism. The device has an exterior lock assembly with a small battery cell and combination lock. Proper entry by a user of a security code allows the battery to operate a small motor within the exterior lock assembly. The small motor manipulates a cam-plunger which moves an actuator pin into a thumb piece. The user applies a force on to the thumb piece. This force is transmitted by the thumb piece to a latch engagement mechanism by the actuator pin. The latch engagement mechanism operates the door latch. 6 figs.

  11. Mechanism of Gravity Impulse

    E-Print Network [OSTI]

    Ning Wu

    2005-10-01T23:59:59.000Z

    It is well-known that energy-momentum is the source of gravitational field. For a long time, it is generally believed that only stars with huge masses can generate strong gravitational field. Based on the unified theory of gravitational interactions and electromagnetic interactions, a new mechanism of the generation of gravitational field is studied. According to this mechanism, in some special conditions, electromagnetic energy can be directly converted into gravitational energy, and strong gravitational field can be generated without massive stars. Gravity impulse found in experiments is generated by this mechanism.

  12. Rotary mechanical latch

    DOE Patents [OSTI]

    Spletzer, Barry L.; Martinez, Michael A.; Marron, Lisa C.

    2012-11-13T23:59:59.000Z

    A rotary mechanical latch for positive latching and unlatching of a rotary device with a latchable rotating assembly having a latching gear that can be driven to latched and unlatched states by a drive mechanism such as an electric motor. A cam arm affixed to the latching gear interfaces with leading and trailing latch cams affixed to a flange within the drive mechanism. The interaction of the cam arm with leading and trailing latch cams prevents rotation of the rotating assembly by external forces such as those due to vibration or tampering.

  13. Mechanical Compression Heat Pumps 

    E-Print Network [OSTI]

    Apaloo, T. L.; Kawamura, K.; Matsuda, J.

    1986-01-01T23:59:59.000Z

    to develop, design and test compressors built to meet the needs of the mechanically demanding industrial heat pump applications which often require high compression ratios and temperatures in excess of 200 degrees F. This paper will review the theoretical...

  14. Renewable Auction Mechanism (RAM)

    Broader source: Energy.gov [DOE]

    The Renewable Auction Mechanism (RAM), approved by the California Public Utilities Commission (CPUC) in December 2010, is expected to result in 1,299 megawatts (MW) of new distributed generation ...

  15. Property Custodians: Don't Throw Excessed JLab Property into...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    before these items may be disposed of. Remember: Only Property Management staff may recycle or dispose of excessed property. All unused, unneeded, or unserviceable property,...

  16. Accountable Property Representatives List and Property Pass Signer...

    Broader source: Energy.gov (indexed) [DOE]

    Accountable Property RepresentativesProperty Pass Authorization 1202015 Employee Authorized Organization Phone APR Primary Property Pass Signer PETEET, LISA J. ALL ORGS (202)...

  17. J. Numer. Anal. Meth. Geomech., 25, (2001), 1285-1303 DETERMINATION OF ROCK MASS STRENGTH PROPERTIES BY

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    2001-01-01T23:59:59.000Z

    - France SUMMARY A method for determining fractured rock mass properties is presented here on the basis rock mass depends on the properties of the intact rock and the fractures. The properties of the intact provide empirical estimations for mechanical properties of fractured rock masses (Barton et al.2

  18. Jar mechanism accelerator

    SciTech Connect (OSTI)

    Anderson, E.A.; Webb, D.D.

    1989-07-11T23:59:59.000Z

    This patent describes an accelerator for use with a jar mechanism in a well pipe string to enhance the jarring impact delivered to a stuck object wherein the jar mechanism includes inner and outer members for connection, respectively, between the well pipe string the stuck object. The jar mechanism members are constructed to (1) restrict relative longitudinal movement therebetween to build up energy in the well pipe string and accelerator and then (2) to release the jar mechanism members for unrestrained, free relative longitudinal movement therebetween to engage jarring surfaces on the jar mechanism members for delivering a jarring impact to the stuck object. The accelerator includes: inner and outer telescopically connected members relatively movable longitudinally to accumulate energy in the accelerator; the inner and outer accelerator members each having means for connecting the accelerator in the well pipe string; means associated with the inner and outer members for initially accomodating a predetermined minimum length of unrestrained, free relative longitudinal movement between the inner and outer accelerator members.

  19. Multi-scale electrical and thermal properties of aligned multi-walled carbon nanotubes and their composites

    E-Print Network [OSTI]

    Yamamoto, Namiko

    2011-01-01T23:59:59.000Z

    Carbon nanotubes (CNTs) are a potential new component to be incorporated into existing aerospace structural composites for multi-functional (mechanical, electrical, thermal, etc.) property enhancement and tailoring. ...

  20. Program Transformation Mechanics A Classification of Mechanisms for Program Transformation

    E-Print Network [OSTI]

    Utrecht, Universiteit

    Program Transformation Mechanics A Classification of Mechanisms for Program Transformation with a Survey of Existing Transformation Systems Jonne van Wijngaarden Eelco Visser UU-CS-2003-048 Institute Transformation Mechanics A Classification of Mechanisms for Program Transformation with a Survey of Existing

  1. Mechanical & Industrial Engineering

    E-Print Network [OSTI]

    Mountziaris, T. J.

    on the PI's current research on energy harvesting nanowires, Li-ion batteries, and PEM fuel cells. In energy nanowires from both modeling and in-situ quantitative microscopy perspectives. In Li-ion battery work, we-ion intercalation into nanowires. The last, electro-mechanical characterization of degraded and fresh electrode

  2. Mechanical engineering Department Seminar

    E-Print Network [OSTI]

    Mechanical engineering Department Seminar Wynter J. Duncanson Department of Aerospace and Ocean Engineering Virginia Tech Smart' Bubbles for Acoustic Contrast in Oil Reservoirs 11:00 AM Friday, 19 April engineering from Boston University. Her doctoral research was devoted to designing surface architectures

  3. Mechanical engineering Department Seminar

    E-Print Network [OSTI]

    Lin, Xi

    -electronics, soft robotics, and bio-integrated systems. Host: Basu #12;, Urbana-Champaign Mechanical Design and Fabrication Techniques for Bio-Electronic Systems 11:00 AM Friday, 7 February 2014 Room 245, 110 Cummington Mall Refreshments served at 10:45 AM Biological systems

  4. Mechanical & Biomedical Engineering

    E-Print Network [OSTI]

    Barrash, Warren

    * Engineering Statistics or Probability and Statistics* 3 ME 380 Kinematics & Machine Dynamics 4 ME, CE, or ENGRMechanical & Biomedical Engineering Department BACHELOR OF SCIENCE IN MECHANICAL ENGINEERING COURSE Differential Equations and Matrix Theory 4 ENGR 245 Introduction to Materials Science & Engineering 3 ENGR 210

  5. Imaging the Antikythera Mechanism

    SciTech Connect (OSTI)

    Malzbender, Tom (Hewlett Packard Laboratories) [Hewlett Packard Laboratories

    2011-01-12T23:59:59.000Z

    In 1900, a party of sponge divers chanced on the wreck of a Roman merchant vessel between Crete and mainland Greece. It was found to contain numerous ancient Greek treasures, among them a mysterious lump of clay that split open to reveal 'mathematical gears' as it dried out. This object is now known as the Antikythera Mechanism, one of the most enlightening artifacts in terms of revealing the advanced nature of ancient Greek science and technology. In 2005 we travelled to the National Archeological Museum in Athens to apply our Reflectance Imaging methods to the mechanism in the hopes of revealing ancient writing on the device. We were successful, and along with the results of Microfocus CT imaging, we are able to decipher 3000 characters compared with the original 800 known. This lead to an understanding that the device was a mechanical, astronomical computer from 150 B.C.E. capable of predicting solar and lunar eclipses along with other celestial events. This talk will overview both the imaging methods as well as what they reveal about the Antikythera Mechanism.

  6. STUDENT HANDBOOK MECHANICAL ENGINEERING

    E-Print Network [OSTI]

    Krstic, Miroslav

    accredited programs) Aerospace and Mechanical Engineering: · An ability to apply knowledge of mathematics-long learning. · A knowledge of contemporary issues. · An ability to use modern engineering techniques, skills, and computing tools necessary for engineering practice. Additionally: Aerospace Engineering · Knowledge of key

  7. Mechanical & Aerospace Engineering

    E-Print Network [OSTI]

    implementation of predictive methods in commercial, numerical codes. Finally, opportunities for students University in 2007. During this time, he has been elected to several leadership positions within the ASME, including as the secretary of the ASME Research Committee on the Mechanics of Jointed Structures, he has

  8. ################### g VM Production Mechanisms

    E-Print Network [OSTI]

    Kai­C. Voss, Bonn University 1 Vector meson production at HERA ############################### ################# ############### ############ #################################### ######################################### ############################ #12; Kai­C. Voss, Bonn University 2 Vector meson production at HERA # ################################################## ############################## ## ####################################### # # ## # ######## ### #### # # #12; Kai­C. Voss, Bonn University 3 Vector meson production at HERA VM Production Mechanisms soft

  9. Department of Mechanical Engineering

    E-Print Network [OSTI]

    Li, Teng

    Department of Mechanical Engineering 2014 Fast Facts Faculty Based on 2013 statistics from Master's Degrees Awarded 45 Doctorate Degrees Awarded Funding Fiscal Year 2013 $20M Total Research for Energetic Concepts Development Center for Environmental Energy Engineering Center for Risk and Reliability

  10. MECHANICAL TEST LAB CAPABILITIES

    E-Print Network [OSTI]

    MECHANICAL TEST LAB CAPABILITIES · Static and cyclic testing (ASTM and non-standard) · Impact drop testing · Slow-cycle fatigue testing · High temperature testing to 2500°F · ASTM/ Boeing/ SACMA standard testing · Ability to design and fabricate non-standard test fixtures and perform non-standard tests

  11. Mechanical & Aerospace Engineering

    E-Print Network [OSTI]

    Reisslein, Martin

    conductivity. Coupled with its low thermal conductivity, polymer thermoelectric composites are attractive and thermoelectric applications. I will show that the thermal conductivity of ultra-thin polymer films can both conductivity and phonon transport mechanisms over the past 2 decades, owing much to the challenging needs

  12. Mechanical and Aerospace Engineering

    E-Print Network [OSTI]

    Integration Specialist in the Smart Grid Technologies and Strategy Division of the California IndependentMechanical and Aerospace Engineering seminar The Challenges of Renewable Energy Integration into the CAISO Grid Abstract I will be presenting who the CAISO is and what we do. We will also discuss where we

  13. Residential Mechanical Precooling

    SciTech Connect (OSTI)

    German, A.; Hoeschele, M.

    2014-12-01T23:59:59.000Z

    This research conducted by the Alliance for Residential Building Innovation team evaluated mechanical air conditioner pre-cooling strategies in homes throughout the United States. EnergyPlus modeling evaluated two homes with different performance characteristics in seven climates. Results are applicable to new construction homes and most existing homes built in the last 10 years, as well as fairly efficient retrofitted homes.

  14. Mechanical Characterization of Rigid Polyurethane Foams.

    SciTech Connect (OSTI)

    Lu, Wei-Yang

    2014-12-01T23:59:59.000Z

    Foam materials are used to protect sensitive components from impact loading. In order to predict and simulate the foam performance under various loading conditions, a validated foam model is needed and the mechanical properties of foams need to be characterized. Uniaxial compression and tension tests were conducted for different densities of foams under various temperatures and loading rates. Crush stress, tensile strength, and elastic modulus were obtained. A newly developed confined compression experiment provided data for investigating the foam flow direction. A biaxial tension experiment was also developed to explore the damage surface of a rigid polyurethane foam.

  15. Non-representative quantum mechanical weak values

    E-Print Network [OSTI]

    B. E. Y. Svensson

    2015-03-06T23:59:59.000Z

    The operational definition of a weak value for a quantum mechanical system involves the limit of the weak measurement strength tending to zero. I study how this limit compares to the situation for the undisturbed (no weak measurement) system. Under certain conditions, which I investigate, this limit is discontinuous in the sense that it does not merge smoothly to the Hilbert space description of the undisturbed system. Hence, in these discontinuous cases, the weak value does not represent the undisturbed system. As a result, conclusions drawn from such weak values regarding the properties of the studied system cannot be upheld. Examples are given.

  16. Experimental Mechanics manuscript No. (will be inserted by the editor)

    E-Print Network [OSTI]

    Composite materials, because of their remarkable compromise between weight and mechanical properties become-to-layer interlock woven composite deve- loped by SNECMA (SAFRAN group) made out of carbon fiber tows and an epoxy-of-plane shear modulus of a 3D woven composite R. Gras · H. Leclerc · S. Roux · S. Otin · J. Schneider · J.-N. P

  17. Mechanical Harvesting of Corn.

    E-Print Network [OSTI]

    Sorenson, J. W. (Jerome Wallace); Smith, H. P. (Harris Pearson)

    1948-01-01T23:59:59.000Z

    - - TEXAS AGRICULTURAL EXPERIMENT STATION R. D. LEWIS, Director ' College Station, Texas BULLETIN 706 OCTOBER 1948 Mechanical Harvesting of Corn H. P. SMITH and J. W. SORENSON, JR. Department of Agricultural Engineering LlBRARY Atricaltr... of corn, from which they harvest about 77 million bushels valued at about 584 million. Most of the corn produced in Texas is harvested by hand. There were approximately 800 corn-picking machines of all types used in Texas in 1947. Texas farmers grow...

  18. WINTERTemplate Geochemical mechanisms of

    E-Print Network [OSTI]

    Borissova, Daniela

    WINTERTemplate 01 Geochemical mechanisms of carbonate equilibria in the system CO2 -H2O-CaCO3 #12 dissolved in soil · Dissolution of CaCO3 · Precipitation of CaCO3 · Physicochemical precipitation (prevention of the CO2 outgassing) #12;07Dissolution of CaCO3 H2CO3 HCO3 - CO3 2- H+ CO3 2- + H+ HCO3 - HCO3

  19. Mechanics of collective unfolding

    E-Print Network [OSTI]

    M Caruel; J. -M Allain; L Truskinovsky

    2015-01-07T23:59:59.000Z

    Mechanically induced unfolding of passive crosslinkers is a fundamental biological phenomenon encountered across the scales from individual macro-molecules to cytoskeletal actin networks. In this paper we study a conceptual model of athermal load-induced unfolding and use a minimalistic setting allowing one to emphasize the role of long-range interactions while maintaining full analytical transparency. Our model can be viewed as a description of a parallel bundle of N bistable units confined between two shared rigid backbones that are loaded through a series spring. We show that the ground states in this model correspond to synchronized, single phase configurations where all individual units are either folded or unfolded. We then study the fine structure of the wiggly energy landscape along the reaction coordinate linking the two coherent states and describing the optimal mechanism of cooperative unfolding. Quite remarkably, our study shows the fundamental difference in the size and structure of the folding-unfolding energy barriers in the hard (fixed displacements) and soft (fixed forces) loading devices which persists in the continuum limit. We argue that both, the synchronization and the non-equivalence of the mechanical responses in hard and soft devices, have their origin in the dominance of long-range interactions. We then apply our minimal model to skeletal muscles where the power-stroke in acto-myosin crossbridges can be interpreted as passive folding. A quantitative analysis of the muscle model shows that the relative rigidity of myosin backbone provides the long-range interaction mechanism allowing the system to effectively synchronize the power-stroke in individual crossbridges even in the presence of thermal fluctuations. In view of the prototypical nature of the proposed model, our general conclusions pertain to a variety of other biological systems where elastic interactions are mediated by effective backbones.

  20. Mechanical behavior of closed-cell and hollow-sphere metallic foams

    E-Print Network [OSTI]

    Sanders, Wynn Steven, 1974-

    2002-01-01T23:59:59.000Z

    (cont.) The elastic anisotropy and yield surfaces are fully characterized, and numerical equations are developed to allow the simple evaluation of the effect of geometric and material properties on the mechanical behavior ...

  1. Analytical and experimental procedures in nonlinear viscoelastic parameter characterization using dynamic mechanical techniques 

    E-Print Network [OSTI]

    Golden, Peter Joseph

    1996-01-01T23:59:59.000Z

    Traditional methods of viscoelastic material characterization lack the ability to rapidly characterize nonlinear viscoelastic materials. A method of rapidly identifying linear viscoelastic material properties is Dynamic Mechanical Analysis (DMA...

  2. Development of cell-laden hydrogels with high mechanical strength for tissue engineering applications

    E-Print Network [OSTI]

    Shin, Hyeongho

    2014-01-01T23:59:59.000Z

    The development of materials with biomimetic mechanical and biological properties is of great interest for regenerative medicine applications. Hydrogels are a promising class of biomaterials due to several advantages, ...

  3. Fundamental mechanisms of micromachine reliability

    SciTech Connect (OSTI)

    DE BOER,MAARTEN P.; SNIEGOWSKI,JEFFRY J.; KNAPP,JAMES A.; REDMOND,JAMES M.; MICHALSKE,TERRY A.; MAYER,THOMAS K.

    2000-01-01T23:59:59.000Z

    Due to extreme surface to volume ratios, adhesion and friction are critical properties for reliability of Microelectromechanical Systems (MEMS), but are not well understood. In this LDRD the authors established test structures, metrology and numerical modeling to conduct studies on adhesion and friction in MEMS. They then concentrated on measuring the effect of environment on MEMS adhesion. Polycrystalline silicon (polysilicon) is the primary material of interest in MEMS because of its integrated circuit process compatibility, low stress, high strength and conformal deposition nature. A plethora of useful micromachined device concepts have been demonstrated using Sandia National Laboratories' sophisticated in-house capabilities. One drawback to polysilicon is that in air the surface oxidizes, is high energy and is hydrophilic (i.e., it wets easily). This can lead to catastrophic failure because surface forces can cause MEMS parts that are brought into contact to adhere rather than perform their intended function. A fundamental concern is how environmental constituents such as water will affect adhesion energies in MEMS. The authors first demonstrated an accurate method to measure adhesion as reported in Chapter 1. In Chapter 2 through 5, they then studied the effect of water on adhesion depending on the surface condition (hydrophilic or hydrophobic). As described in Chapter 2, they find that adhesion energy of hydrophilic MEMS surfaces is high and increases exponentially with relative humidity (RH). Surface roughness is the controlling mechanism for this relationship. Adhesion can be reduced by several orders of magnitude by silane coupling agents applied via solution processing. They decrease the surface energy and render the surface hydrophobic (i.e. does not wet easily). However, only a molecular monolayer coats the surface. In Chapters 3-5 the authors map out the extent to which the monolayer reduces adhesion versus RH. They find that adhesion is independent of RH up to a threshold value, depending on the coating chemistry. The mechanism for the adhesion increase beyond this threshold value is that the coupling agent reconfigures from a surface to a bulk phase (Chapter 3). To investigate the details of how the adhesion increase occurs, the authors developed the mechanics for adhesion hysteresis measurements. These revealed that near-crack tip compression is the underlying cause of the adhesion increase (Chapter 4). A vacuum deposition chamber for silane coupling agent deposition was constructed. Results indicate that vapor deposited coatings are less susceptible to degradation at high RH (Chapter 5). To address issues relating to surfaces in relative motion, a new test structure to measure friction was developed. In contrast to other surface micromachined friction test structures, uniform apparent pressure is applied in the frictional contact zone (Chapter 6). The test structure will enable friction studies over a large pressure and dynamic range. In this LDRD project, the authors established an infrastructure for MEMS adhesion and friction metrology. They then characterized in detail the performance of hydrophilic and hydrophobic films under humid conditions, and determined mechanisms which limit this performance. These studies contribute to a fundamental understanding for MEMS reliability design rules. They also provide valuable data for MEMS packaging requirements.

  4. Sensitivity analysis of GSI based mechanical characterization of rock mass

    E-Print Network [OSTI]

    Ván, P

    2012-01-01T23:59:59.000Z

    Recently, the rock mechanical and rock engineering designs and calculations are frequently based on Geological Strength Index (GSI) method, because it is the only system that provides a complete set of mechanical properties for design purpose. Both the failure criteria and the deformation moduli of the rock mass can be calculated with GSI based equations, which consists of the disturbance factor, as well. The aim of this paper is the sensitivity analysis of GSI and disturbance factor dependent equations that characterize the mechanical properties of rock masses. The survey of the GSI system is not our purpose. The results show that the rock mass strength calculated by the Hoek-Brown failure criteria and both the Hoek-Diederichs and modified Hoek-Diederichs deformation moduli are highly sensitive to changes of both the GSI and the D factor, hence their exact determination is important for the rock engineering design.

  5. Defect-related internal dissipation in mechanical resonators and the study of coupled mechanical systems.

    SciTech Connect (OSTI)

    Friedmann, Thomas Aquinas; Czaplewski, David A.; Sullivan, John Patrick; Modine, Normand Arthur; Wendt, Joel Robert; Aslam, Dean (Michigan State University, Lansing, MI); Sepulveda-Alancastro, Nelson (University of Puerto Rico, Mayaguez, PR)

    2007-01-01T23:59:59.000Z

    Understanding internal dissipation in resonant mechanical systems at the micro- and nanoscale is of great technological and fundamental interest. Resonant mechanical systems are central to many sensor technologies, and microscale resonators form the basis of a variety of scanning probe microscopies. Furthermore, coupled resonant mechanical systems are of great utility for the study of complex dynamics in systems ranging from biology to electronics to photonics. In this work, we report the detailed experimental study of internal dissipation in micro- and nanomechanical oscillators fabricated from amorphous and crystalline diamond materials, atomistic modeling of dissipation in amorphous, defect-free, and defect-containing crystalline silicon, and experimental work on the properties of one-dimensional and two-dimensional coupled mechanical oscillator arrays. We have identified that internal dissipation in most micro- and nanoscale oscillators is limited by defect relaxation processes, with large differences in the nature of the defects as the local order of the material ranges from amorphous to crystalline. Atomistic simulations also showed a dominant role of defect relaxation processes in controlling internal dissipation. Our studies of one-dimensional and two-dimensional coupled oscillator arrays revealed that it is possible to create mechanical systems that should be ideal for the study of non-linear dynamics and localization.

  6. ENGINEERING MECHANICS SEMINARSENGINEERING MECHANICS SEMINARS BIO COMPOSITES FOR AVIATION

    E-Print Network [OSTI]

    Ponce, V. Miguel

    carbon composite general aviation aircraft); and Manager of Materials and Structures Research at Sikorsky temperature and bio material composite programs. In bio composite material programs Ron frequently worksENGINEERING MECHANICS SEMINARSENGINEERING MECHANICS SEMINARS BIO COMPOSITES FOR AVIATION Ron

  7. MECHANICAL ENGINEERING Both faculty and students in mechanical engineering at

    E-Print Network [OSTI]

    Gelfond, Michael

    MECHANICAL ENGINEERING RESEARCH Both faculty and students in mechanical engineering at Texas Tech work on a variety of research projects including heat transfer, combustion, and energetic materials analysis; human- centric design research; control science and engineering; computational fluid dynamics

  8. PROPERTIES OF DEFECTS AND IMPLANTS IN Mg+ IMPLANTED SILICON CARBIDE

    SciTech Connect (OSTI)

    Jiang, Weilin; Zhu, Zihua; Varga, Tamas; Bowden, Mark E.; Manandhar, Sandeep; Roosendaal, Timothy J.; Hu, Shenyang Y.; Henager, Charles H.; Kurtz, Richard J.; Wang, Yongqiang

    2013-09-25T23:59:59.000Z

    As a candidate material for fusion reactor designs, silicon carbide (SiC) under high-energy neutron irradiation undergoes atomic displacement damage and transmutation reactions that create magnesium as one of the major metallic products. The presence of Mg and lattice disorder in SiC is expected to affect structural stability and degrade thermo-mechanical properties that could limit SiC lifetime for service. We have initiated a combined experimental and computational study that uses Mg+ ion implantation and multiscale modeling to investigate the structural and chemical effects in Mg implanted SiC and explore possible property degradation mechanisms.

  9. HEAVY AND THERMAL OIL RECOVERY PRODUCTION MECHANISMS

    SciTech Connect (OSTI)

    Anthony R. Kovscek; Louis M. Castanier

    2002-09-30T23:59:59.000Z

    The Stanford University Petroleum Research Institute (SUPRI-A) conducts a broad spectrum of research intended to help improve the recovery efficiency from difficult to produce reservoirs including heavy oil and fractured low permeability systems. Our scope of work is relevant across near-, mid-, and long-term time frames. The primary functions of the group are to conduct direction-setting research, transfer research results to industry, and educate and train students for careers in industry. Presently, research in SUPRI-A is divided into 5 main project areas. These projects and their goals include: (1) Multiphase flow and rock properties--to develop better understanding of the physics of displacement in porous media through experiment and theory. This category includes work on imbibition, flow in fractured media, and the effect of temperature on relative permeability and capillary pressure. (2) Hot fluid injection--to improve the application of nonconventional wells for enhanced oil recovery and elucidate the mechanisms of steamdrive in low permeability, fractured porous media. (3) Mechanisms of primary heavy oil recovery--to develop a mechanistic understanding of so-called ''foamy oil'' and its associated physical chemistry. (4) In-situ combustion--to evaluate the effect of different reservoir parameters on the insitu combustion process. (5) Reservoir definition--to develop and improve techniques for evaluating formation properties from production information. What follows is a report on activities for the past year. Significant progress was made in all areas.

  10. Quantum mechanical Carnot engine

    E-Print Network [OSTI]

    Bender, C M; Meister, B K

    2000-01-01T23:59:59.000Z

    A cyclic thermodynamic heat engine runs most efficiently if it is reversible. Carnot constructed such a reversible heat engine by combining adiabatic and isothermal processes for a system containing an ideal gas. Here, we present an example of a cyclic engine based on a single quantum-mechanical particle confined to a potential well. The efficiency of this engine is shown to equal the Carnot efficiency because quantum dynamics is reversible. The quantum heat engine has a cycle consisting of adiabatic and isothermal quantum processes that are close analogues of the corresponding classical processes.

  11. Quantum mechanical Carnot engine

    E-Print Network [OSTI]

    C. M. Bender; D. C. Brody; B. K. Meister

    2000-07-03T23:59:59.000Z

    A cyclic thermodynamic heat engine runs most efficiently if it is reversible. Carnot constructed such a reversible heat engine by combining adiabatic and isothermal processes for a system containing an ideal gas. Here, we present an example of a cyclic engine based on a single quantum-mechanical particle confined to a potential well. The efficiency of this engine is shown to equal the Carnot efficiency because quantum dynamics is reversible. The quantum heat engine has a cycle consisting of adiabatic and isothermal quantum processes that are close analogues of the corresponding classical processes.

  12. Efficiency of stripping mechanisms

    E-Print Network [OSTI]

    F. Combes

    2003-08-18T23:59:59.000Z

    There are several physical processes to remove gas from galaxies in clusters, with subsequent starvation and star formation quenching: tidal interactions between galaxies, or tidal stripping from the cluster potential itself, interactions with the hot intra-cluster medium (ICM) through ram pressure, turbulent or viscous stripping, or also outflows from star formation of nuclear activity, We review the observational evidence for all processes, and numerical simulations of galaxies in clusters which support the respective mechanisms. This allows to compare their relative efficiencies, all along cluster formation.

  13. Mechanical engineering Mechanical engineering is about solving problems, designing processes,

    E-Print Network [OSTI]

    Waikato, University of

    the basic engineering sciences of thermal fluid science, separation processes, chemical reactions, unitMechanical engineering Mechanical engineering is about solving problems, designing processes, and making products to improve the quality of human life and shape the economy. Mechanical engineers apply

  14. CARBON NANOTUBES: PROPERTIES AND APPLICATIONS

    SciTech Connect (OSTI)

    Fischer, John, E.

    2009-07-24T23:59:59.000Z

    Carbon nanotubes were discovered in 1991 as a minority byproduct of fullerene synthesis. Remarkable progress has been made in the ensuing years, including the discovery of two basic types of nanotubes (single-wall and multi-wall), great strides in synthesis and purification, elucidation of many fundamental physical properties, and important steps towards practical applications. Both the underlying science and technological potential of SWNT can profitably be studied at the scale of individual tubes and on macroscopic assemblies such as fibers. Experiments on single tubes directly reveal many of the predicted quantum confinement and mechanical properties. Semiconductor nanowires have many features in common with nanotubes, and many of the same fundamental and practical issues are in play – quantum confinement and its effect on properties; possible device structures and circuit architectures; thermal management; optimal synthesis, defect morphology and control, etc. In 2000 we began a small effort in this direction, conducted entirely by undergraduates with minimal consumables support from this grant. With DOE-BES approval, this grew into a project in parallel with the carbon nanotube work, in which we studied of inorganic semiconductor nanowire growth, characterization and novel strategies for electronic and electromechanical device fabrication. From the beginnings of research on carbon nanotubes, one of the major applications envisioned was hydrogen storage for fuel-cell powered cars and trucks. Subsequent theoretical models gave mixed results, the most pessimistic indicating that the fundamental H2-SWNT interaction was similar to flat graphite (physisorption) with only modest binding energies implying cryogenic operation at best. New material families with encouraging measured properties have emerged, and materials modeling has gained enormously in predictive power, sophistication, and the ability to treat a realistically representative number of atoms. One of the new materials, highly porous carbide-derived carbons (CDC), is the subject of an add-on to this grant awarded to myself and Taner Yildirim (NIST). Results from the add-on led eventually to a new 3-year award DE-FG02-08ER46522 “From Fundamental Understanding to Predicting New Nanomaterials for High Capacity Hydrogen Storage”, $1000K, (05/31/2008 - 05/01/2011) with Taner Yildirim and myself as co-PI’s.

  15. The mechanics of active fin-shape control in ray-finned fishes

    E-Print Network [OSTI]

    Lauder, George V.

    allows fishes to change fin area during locomotion, and this architecture provides a balance between forces and displacements as a function of the fin-ray geometry and material properties? In particular describe the experimental techniques used to study these mechanical properties. We then derive an equation

  16. Top Quark Properties

    E-Print Network [OSTI]

    Tony M. Liss

    2012-12-03T23:59:59.000Z

    I review the latest results on properties of the top quark from the Tevatron and the LHC, including results measured in $t\\bar{t}$ and single-top events on the mass, width, couplings, and spin correlations.

  17. Petroleum property valuation

    E-Print Network [OSTI]

    Smith, James L.

    2003-01-01T23:59:59.000Z

    This paper provides an overview of the principal economic methods employed to assess the value of petroleum properties. The difference between wellhead and in situ resource values is examined, as well as drawbacks inherent ...

  18. Headquarters Personal Property Management

    Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

    2004-10-25T23:59:59.000Z

    To establish procedures for managing Government personal property owned or leased by the Department of Energy and in the custody of DOE Headquarters employees, including those in the National Nuclear Security Administration. Cancels DOE HQ O 580.1A

  19. Solar Property Tax Exemption

    Broader source: Energy.gov [DOE]

    In Missouri, solar energy systems not held for resale are exempt from state, local, and county property taxes. As enacted in July 2013, the law does not define solar energy systems.

  20. The Mechanical Harvesting of Cotton.

    E-Print Network [OSTI]

    Smith, H. P.; Killough, D. T.; Byrom, M. H.; Scoates, D.; Jones, D. L.

    1932-01-01T23:59:59.000Z

    Stripping Rolls 45 Efficiency of the Texas Station Cotton Harvester --_-_.__---.__--___-.------- 47 --loping Varieties of Cotton to Meet the Needs of Mechanical Har- ~esting 54 owledgments 58 nary 58 List of Patents on Cotton Harvesters ' 60 ,ing ant... patent on a mechanical cotton picker, was apparently taken out in the year 1850. The development of a successful mechanical cotton harvester has been slow, due not only to the mechanical problems en- countered in handling the fiber, but also...