Sample records for brittle material failure

  1. The effect of inclusions in brittle material

    E-Print Network [OSTI]

    Janeiro, Raymond Pinho

    2009-01-01T23:59:59.000Z

    This thesis experimentally investigates the cracking behavior of brittle heterogeneous materials. Unconfined, uniaxial compression tests are conducted on prismatic gypsum specimens containing either one, or two, inclusions. ...

  2. Fabrication of brittle materials -- current status

    SciTech Connect (OSTI)

    Scattergood, R.O.

    1988-12-01T23:59:59.000Z

    The research initiatives in the area of precision fabrication will be continued in the upcoming year. Three students, T. Bifano (PhD), P. Blake (PhD) and E. Smith (MS), finished their research programs in the last year. Sections 13 and 14 will summarize the essential results from the work of the Materials Engineering students Blake and Smith. Further details will be presented in forthcoming publications that are now in preparation. The results from Bifano`s thesis have been published in adequate detail and need not be summarized further. Three new students, S. Blackley (MS), H. Paul (PhD), and S. Smith (PhD) have joined the program and will continue the research efforts in precision fabrication. The programs for these students will be outlined in Sections 15 and 16. Because of the success of the earlier work in establishing new process models and experimental techniques for the study of diamond turning and diamond grinding, the new programs will, in part, build upon the earlier work. This is especially true for investigations concerned with brittle materials. The basic understanding of material response of nominally brittle materials during machining or grinding operations remains as a challenge. The precision fabrication of brittle materials will continue as an area of emphasis for the Precision Engineering Center.

  3. Brittle Failure Design Criteria for Ductile Cast Iron Spent-Fuel

    Office of Scientific and Technical Information (OSTI)

    for Ductile and Brittle Failure Design Criteria for Ductile Cast Iron Spent-Fuel Shipping Containers This report was prepared as an account of work sponsored by an...

  4. A micromechanical basis for partitioning the evolution of grain bridging in brittle materials

    E-Print Network [OSTI]

    Foulk III, J.W.; Cannon, R.M.; Johnson, G.C.; Klein, P.A.; Ritchie, R.O.

    2008-01-01T23:59:59.000Z

    the strength and fracture of materials. Vol. 3. Perga- monimpact damage in brittle materials. International Journal ofin polycrystalline brittle materials. part II: numerical

  5. Microfracturing, damage, and failure of brittle granites and Ze'ev Reches

    E-Print Network [OSTI]

    Ze'ev, Reches

    Microfracturing, damage, and failure of brittle granites Oded Katz1 and Ze'ev Reches Institute and the eventual brittle failure are experimentally analyzed for Mount Scott granite of Oklahoma. We quantify of the medium-grain-size granite were loaded triaxially at dry conditions, room temperature, and under 41 MPa

  6. NON-DESTRUCTIVE FAILURE PREDICTION FOR BRITTLE SOLIDS

    E-Print Network [OSTI]

    Evans, A.G.

    2013-01-01T23:59:59.000Z

    on the basis of detailed failure analyses conducted on thisprobabilities enter the analysis: the failure probability,failure model, Such techniques involve the detection and analysis

  7. Fracture mechanics applied to the machining of brittle materials

    SciTech Connect (OSTI)

    Hiatt, G.D.; Strenkowski, J.S.

    1988-12-01T23:59:59.000Z

    Research has begun on incorporating fracture mechanics into a model of the orthogonal cutting of brittle materials. Residual stresses are calculated for the machined material by a combination of Eulerian and Lagrangian finite element models and then used in the calculation of stress intensity factors by the Green`s Function Method.

  8. Microscale and mesoscale discrete models for dynamic fracture of structures built of brittle material

    E-Print Network [OSTI]

    Microscale and mesoscale discrete models for dynamic fracture of structures built of brittle are derived either at microscale with random distribution of material properties or at a mesoscale

  9. Simulations of ductile flow in brittle material processing

    SciTech Connect (OSTI)

    Luh, M.H.; Strenkowski, J.S.

    1988-12-01T23:59:59.000Z

    Research is continuing on the effects of thermal properties of the cutting tool and workpiece on the overall temperature distribution. Using an Eulerian finite element model, diamond and steel tools cutting aluminum have been simulated at various, speeds, and depths of cut. The relative magnitude of the thermal conductivity of the tool and the workpiece is believed to be a primary factor in the resulting temperature distribution in the workpiece. This effect is demonstrated in the change of maximum surface temperatures for diamond on aluminum vs. steel on aluminum. As a preliminary step toward the study of ductile flow in brittle materials, the relative thermal conductivities of diamond on polycarbonate is simulated. In this case, the maximum temperature shifts from the rake face of the tool to the surface of the machined workpiece, thus promoting ductile flow in the workpiece surface.

  10. The effect of complex inclusion geometries on fracture and crack coalescence behavior in brittle material

    E-Print Network [OSTI]

    Morgan, Stephen Philip

    2011-01-01T23:59:59.000Z

    This research study investigates the cracking processes in a brittle material associated with inclusions of varying shape, orientation and materials. Specifically, this study summarizes a series of uniaxial compression ...

  11. Clamping of Solid Tungsten Components for the Bulk W Divertor Row in JET – Precautionary Design for a Brittle Material

    E-Print Network [OSTI]

    Clamping of Solid Tungsten Components for the Bulk W Divertor Row in JET – Precautionary Design for a Brittle Material

  12. Fracture process zone : microstructure and nanomechanics in quasi-brittle materials

    E-Print Network [OSTI]

    Brooks, Zenzile (Zenzile Z.)

    2013-01-01T23:59:59.000Z

    Cracks begin (and end) at a crack tip; the "Fracture Process Zone" (FPZ) is a region of damage around the crack tip. The context of this research is the FPZ in quasi-brittle materials, which is characterized by cracking ...

  13. Structural reliability of brittle materials - an analytical method

    E-Print Network [OSTI]

    Shields, Charles Burch

    1967-01-01T23:59:59.000Z

    on observed failure stress can be ex?la!ned. Pre~. ". cl (1) ?resents an example of this effect which illustrates the. mar'ked decrease in fai1ure. 'tran- th &7ith increasing test e1cment size z'hich is ob. . c;rved1. Testing of clem ni. . of varying... and Reliability of- Iic. chanlcal Systcr!s, Especially Ai craft Struct:ur es Aeronautical Syst. ems Div. , Al. SC, USA'& IIPAPB, Ohf o& (July 1961). 34 AI'!-";. I" D I X AN EX!DiPLE PPOBI, r:, &I '3'he comipuLcr programs presentecl in this paper do not...

  14. Large-Scale Atomistic Simulations of Material Failure

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Abraham, Farid [IBM Almaden Research; Duchaineau, Mark [LLNL; Wirth, Brian [LLNL; Heidelberg,; Seager, Mark [LLNL; De La Rubia, Diaz [LLNL

    These simulations from 2000 examine the supersonic propagation of cracks and the formation of complex junction structures in metals. Eight simulations concerning brittle fracture, ductile failure, and shockless compression are available.

  15. Failure Stress and Apparent Elastic Modulus of Diesel Particulate...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    test specimen geometries and test methods for brittle materials are adapted to DPF architecture to evaluate failure initiation stress and apparent elastic modulus of the ceramics....

  16. Effect of Load Path on Mode of Failure at the Brittle-ductile Transition in Well-sorted Aggregates of St. Peter Sand

    E-Print Network [OSTI]

    Dilci, Gokturk Mehmet

    2010-10-12T23:59:59.000Z

    in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 2010 Major Subject: Geology EFFECT OF LOAD PATH ON MODE OF FAILURE AT THE BRITTLE-DUCTILE TRANSITION IN WELL-SORTED AGGREGATES OF ST. PETER SAND... prior isotropic pressurization and successive triaxial compression with decreasing Pc are shown as red, and the load paths that comprise a prior high magnitude isotropic pressurization, a partial isotropic unloading down to the intermediate magnitudes...

  17. A micromechanical basis for partitioning the evolution of grainbridging in brittle materials

    SciTech Connect (OSTI)

    Foulk III, J.W.; Cannon, R.M.; Johnson, G.C.; Klein, P.A.; Ritchie, R.O.

    2006-10-09T23:59:59.000Z

    A micromechanical model is developed for grain bridging inmonolithic ceramics. Specifically, bridge formation of a single,non-equiaxed grain spanning adjacent grains is addressed. A cohesive zoneframework enables crack initiation and propagation along grainboundaries. The evolution of the bridge is investigated through avariance in both grain angle and aspect ratio. We propose that thebridging process can be partitioned into five distinct regimes ofresistance: propagate, kink, arrest, stall, and bridge. Although crackpropagation and kinking are well understood, crack arrest and subsequent"stall" have been largely overlooked. Resistance during the stall regimeexposes large volumes of microstructure to stresses well in excess of thegrain boundary strength. Bridging can occur through continued propagationor reinitiation ahead of the stalled crack tip. The driving forcerequired to reinitiate is substantially greater than the driving forcerequired to kink. In addition, the critical driving force to reinitiateis sensitive to grain aspect ratio but relatively insensitive to grainangle. The marked increase in crack resistance occurs prior to bridgeformation and provides an interpretation for the rapidly risingresistance curves which govern the strength of many brittle materials atrealistically small flaw sizes.

  18. Strengthening, Crack Arrest And Multiple Cracking In Brittle Materials Using Residual Stresses.

    DOE Patents [OSTI]

    Green, David J. (State College, PA); Sglavo, Vincenzo M. (Roncegno, IT); Tandon, Rajan (Fremont, CA)

    2003-02-11T23:59:59.000Z

    Embodiments include a method for forming a glass which displays visible cracking prior to failure when subjected to predetermined stress level that is greater than a predetermined minimum stress level and less than a failure stress level. The method includes determining a critical flaw size in the glass and introducing a residual stress profile to the glass so that a plurality of visible cracks are formed prior to failure when the glass is subjected to a stress that is greater than the minimum stress level and lower than the critical stress. One method for forming the residual stress profile includes performing a first ion exchange so that a first plurality of ions of a first element in the glass are exchanged with a second plurality of ions of a second element that have a larger volume than the first ions. A second ion exchange is also performed so that a plurality of the second ions in the glass are exchanged back to ions of the first element.

  19. FAILURE PREDICTION AND STRESS ANALYSIS OF MICROCUTTING TOOLS

    E-Print Network [OSTI]

    Chittipolu, Sujeev

    2010-07-14T23:59:59.000Z

    -based products are limited because silicon is brittle. Products can be made from other engineering materials and need to be machined in microscale. This research deals with predicting microtool failure by studying spindle runout and tool deflection effects...

  20. 72 Journal of Failure Analysis and PreventionVolume 4(5) October 2004 Analysis of Brittle Fracture of Soda Glass Bottles under Hydrostatic Pressure (continued)

    E-Print Network [OSTI]

    Eagar, Thomas W.

    of Soda Glass Bottles under Hydrostatic Pressure (continued) Analysis of Brittle Fracture of Soda Glass. When soda glass bottles are pressurized to fracture, the crack density in the broken glass to estimate the pressure to which a bottle was subjected by analyzing the glass fragments. The crack patterns

  1. Damage mechanisms in the dynamic fracture of nominally brittle polymers

    E-Print Network [OSTI]

    Davy Dalmas; Claudia Guerra; Julien Scheibert; Daniel Bonamy

    2013-04-23T23:59:59.000Z

    Linear Elastic Fracture Mechanics (LEFM) provides a consistent framework to evaluate quantitatively the energy flux released to the tip of a growing crack. Still, the way in which the crack selects its velocity in response to this energy flux remains far from completely understood. To uncover the underlying mechanisms, we experimentally studied damage and dissipation processes that develop during the dynamic failure of polymethylmethacrylate (PMMA), classically considered as the archetype of brittle amorphous materials. We evidenced a well-defined critical velocity along which failure switches from nominally-brittle to quasi-brittle, where crack propagation goes hand in hand with the nucleation and growth of microcracks. Via post-mortem analysis of the fracture surfaces, we were able to reconstruct the complete spatiotemporal microcracking dynamics with micrometer/nanosecond resolution. We demonstrated that the true local propagation speed of individual crack fronts is limited to a fairly low value, which can be much smaller than the apparent speed measured at the continuum-level scale. By coalescing with the main front, microcracks boost the macroscale velocity through an acceleration factor of geometrical origin. We discuss the key role of damage-related internal variables in the selection of macroscale fracture dynamics.

  2. Correlation of electrical reactor cable failure with materials degradation

    SciTech Connect (OSTI)

    Stuetzer, O.M.

    1986-03-01T23:59:59.000Z

    Complete circuit failure (shortout) of electrical cables typically used in nuclear power plant containments is investigated. Failure modes are correlated with the mechanical deterioration of the elastomeric cable materials. It is found that for normal reactor operation, electrical cables are reliable and safe over very long periods. During high temperature excursions, however, cables pulled across corners under high stress may short out due to conductor creep. Severe cracking will occur in short times during high temperatures (>150/sup 0/C) and in times of the order of years at elevated temperatures (100/sup 0/C to 140/sup 0/C). A theoretical treatment of stress distribution responsible for creep and for cracking by J.E. Reaugh of Science Applications, Inc. is contained in the Appendix. 29 refs., 32 figs.

  3. Ris-R-1736 (EN) Cohesive laws for assessment of materials failure

    E-Print Network [OSTI]

    Risø-R-1736 (EN) Cohesive laws for assessment of materials failure: Theory, experimental methods-opening reaches the critical s decreased to zero, 0 n . The bridging zone is further crack extension, the fracture laws for assessment of materials failure: Theory, experimental methods and application #12;#12;Cohesive

  4. Reactor Materials Program process water piping indirect failure frequency

    SciTech Connect (OSTI)

    Daugherty, W.L.

    1989-10-30T23:59:59.000Z

    Following completion of the probabilistic analyses, the LOCA Definition Project has been subject to various external reviews, and as a result the need for several revisions has arisen. This report updates and summarizes the indirect failure frequency analysis for the process water piping. In this report, a conservatism of the earlier analysis is removed, supporting lower failure frequency estimates. The analysis results are also reinterpreted in light of subsequent review comments.

  5. Experiments for calibration and validation of plasticity and failure material modeling: 304L stainless steel.

    SciTech Connect (OSTI)

    Lee, Kenneth L.; Korellis, John S.; McFadden, Sam X.

    2006-01-01T23:59:59.000Z

    Experimental data for material plasticity and failure model calibration and validation were obtained from 304L stainless steel. Model calibration data were taken from smooth tension, notched tension, and compression tests. Model validation data were provided from experiments using thin-walled tube specimens subjected to path dependent combinations of internal pressure, extension, and torsion.

  6. Failure by fracture and fatigue in 'NANO' and 'BIO'materials

    SciTech Connect (OSTI)

    Ritchie, R.O.; Muhlstein, C.L.; Nalla, R.K.

    2003-12-19T23:59:59.000Z

    The behavior of nanostructured materials/small-volumestructures and biologi-cal/bio-implantable materials, so-called "nano"and "bio" materials, is currently much in vogue in materials science. Oneaspect of this field, which to date has received only limited attention,is their fracture and fatigue properties. In this paper, we examine twotopics in this area, namely the premature fatigue failure ofsilicon-based micron-scale structures for microelectromechanical systems(MEMS), and the fracture properties of mineralized tissue, specificallyhuman bone.

  7. In-Vessel Coil Material Failure Rate Estimates for ITER Design Use

    SciTech Connect (OSTI)

    L. C. Cadwallader

    2013-01-01T23:59:59.000Z

    The ITER international project design teams are working to produce an engineering design for construction of this large tokamak fusion experiment. One of the design issues is ensuring proper control of the fusion plasma. In-vessel magnet coils may be needed for plasma control, especially the control of edge localized modes (ELMs) and plasma vertical stabilization (VS). These coils will be lifetime components that reside inside the ITER vacuum vessel behind the blanket modules. As such, their reliability is an important design issue since access will be time consuming if any type of repair were necessary. The following chapters give the research results and estimates of failure rates for the coil conductor and jacket materials to be used for the in-vessel coils. Copper and CuCrZr conductors, and stainless steel and Inconel jackets are examined.

  8. Amorphous layer coating induced brittle to ductile transition...

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

    layer coating induced brittle to ductile transition in single crystalline SiC nanowires: an atomistic simulation. Amorphous layer coating induced brittle to ductile transition in...

  9. Ductile-to-brittle transition in spallation of metallic glasses

    SciTech Connect (OSTI)

    Huang, X. [State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Institute of Systems Engineering, China Academy of Engineering Physics, Mianyang, Sichuan 621999 (China); Ling, Z. [State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); Dai, L. H., E-mail: lhdai@lnm.imech.ac.cn [State Key Laboratory of Nonlinear Mechanics, Institute of Mechanics, Chinese Academy of Sciences, Beijing 100190 (China); State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 10081 (China)

    2014-10-14T23:59:59.000Z

    In this paper, the spallation behavior of a binary metallic glass Cu{sub 50}Zr{sub 50} is investigated with molecular dynamics simulations. With increasing the impact velocity, micro-voids induced by tensile pulses become smaller and more concentrated. The phenomenon suggests a ductile-to-brittle transition during the spallation process. Further investigation indicates that the transition is controlled by the interaction between void nucleation and growth, which can be regarded as a competition between tension transformation zones (TTZs) and shear transformation zones (STZs) at atomic scale. As impact velocities become higher, the stress amplitude and temperature rise in the spall region increase and micro-structures of the material become more unstable. Therefore, TTZs are prone to activation in metallic glasses, leading to a brittle behavior during the spallation process.

  10. Failure Mode Analysis of a Proposed Manipulator-based Hazardous Material Retrieval System

    E-Print Network [OSTI]

    Cavallaro, Joseph R.

    for manipulators involved in hazardous waste management operations, where failure could be both expensive (supplied by Westinghouse Hanford Company), a design report on the Hose Management Arm (HMA),1 modes of a robot manipulator-based system for tank waste retrieval. The advantages and limitations

  11. Modeling the deformation and failure behavior of FCC and HCP nanocrystalline materials

    E-Print Network [OSTI]

    Wei, Yujie, Ph. D. Massachusetts Institute of Technology

    2006-01-01T23:59:59.000Z

    As foreseen by Richard Feynman in his famous talk titled There's Plenty of Room at the Bottom in 1959, scientists nowadays are miniaturizing structures in materials to achieve better performance as concerned in technical ...

  12. Multiscale modeling and simulation of deformation and failure mechanisms of hierarchical alpha-helical protein materials

    E-Print Network [OSTI]

    Bertaud, Jeremie

    2009-01-01T23:59:59.000Z

    Alpha-helical (AH) protein structures are critical building blocks of life, representing the key constituents of biological materials such as cells, hair, hoof and wool, where they assemble to form hierarchical structures. ...

  13. Analytical model of brittle destruction based on hypothesis of scale similarity

    SciTech Connect (OSTI)

    Arakcheev, A. S., E-mail: asarakcheev@gmail.com; Lotov, K. V. [Russian Academy of Sciences, Budker Institute of Nuclear Physics, Siberian Branch (Russian Federation)

    2012-08-15T23:59:59.000Z

    The size distribution of dust particles in thermonuclear (fusion) devices is closely described by a power law, which may be related to the brittle destruction of materials. The hypothesis of scale similarity leads to the conclusion that the size distribution of particles formed as a result of a brittle destruction is described by a power law with the exponent -{alpha} that can range from -4 to -1. The model of brittle destruction is described in terms of the fractal geometry, and the distribution exponent is expressed via the fractal dimension of packing. Under additional assumptions, it is possible to refine the {alpha} value and, vice versa, to determine the type of destruction using the measured size distribution of particles.

  14. Deformation rate effects on failure modes of open-cell Al foams and textile cellular materials

    E-Print Network [OSTI]

    Barthelat, Francois

    September 2005 Abstract The compressive behavior of open-cell aluminum alloy foam and stainless steel woven: Metallic cellular materials; Dynamic compression; Aluminum foams; Woven textile lattice 0020-7683/$ - see are of attracting interest for a variety of automotive, locomotive, marine, and aerospace applications (Gibson

  15. Surface-Gasification Materials Program. Semiannual progress report for the period ending March 31, 1983

    SciTech Connect (OSTI)

    Bradley, R.A. (comp.)

    1983-05-01T23:59:59.000Z

    Contents of this semiannual report include the following: introduction; (1) plant materials surveillance tests (Illinois Institute of Technology); (2) slagging gasifier refractories - appliction/evaluation (Argonne National Laboratory); (3) protective clothing and claddings - application/evaluation (ANL); (4) ceramic application technology - brittle material design (LANL); (5) advanced pressure vessel materials technology (ORNL); (6) electroslag component casting (ORNL); (7) cost reduction of the electroslag casting manufacturing process (CMU); (8) materials review and component failure analysis in support of coal gasification processes and plants (ANL); (9) process plant materials review, evaluation, and support (ORNL).

  16. Failure of the Shockley-Haynes Mobility Experiment with organic semiconducting materials

    E-Print Network [OSTI]

    Boehme, Hollis Clyde

    1961-01-01T23:59:59.000Z

    requirements for the degree of NASTER OF SCIENCE August 1961 Major Subjectt Physics PAILUHE OP THE SHOCKLEY-HAYNES MO31LITY EXPERIMENT I/ITH ORGANIC SEMICONDUCTING MATERIALS s nl A rA X W R i 0 0 g A Thesis HOLLIS CLYDE BOEHME Approved... s . ~pa '"e iii List of Tables I. Intro4uotion II. Sample Prepare. tion III. Nobility FEeasurement Attempts IV. Contacts. V. Discussion of Results BlblioEErap?y 16 52 LIST Oy r IQURr', S ~pa e l. Experimental arrangement of Shockley and Haynes...

  17. 318 IEEE TRANSACTIONS ON DEVICE AND MATERIALS RELIABILITY, VOL. 14, NO. 1, MARCH 2014 Thermomechanical Failure Analysis of

    E-Print Network [OSTI]

    Huang, Rui

    Thermomechanical Failure Analysis of Through-Silicon Via Interface Using a Shear-Lag Model With Cohesive Zone Suk for dam- age initiation and fracture initiation, respectively. It is found that via extrusion]­[17] as shown in Fig. 1. The via extrusion can cause interfacial failure of a TSV and/or cracking in Si near

  18. Fracture characterization of clays and clay-like materials using flattened Brazilian Test

    E-Print Network [OSTI]

    Agaiby, Shehab Sherif Wissa

    2013-01-01T23:59:59.000Z

    Fracture mechanics has been used for many years to study the mechanical behavior of brittle and quasi-brittle materials like concrete, rock, wood, and ceramics. To date, the application of fracture mechanics to soils has ...

  19. Insulating and sheathing materials of electric and optical cables - Common test methods - Part 5-1: Methods specific to filling compounds - Drop-point - Separation of oil - Lower temperature brittleness - Total acid number - Absence of corrosive components - Permittivity at 23 °C - DC resistivity at 23 °C and 100 °C

    E-Print Network [OSTI]

    International Electrotechnical Commission. Geneva

    2004-01-01T23:59:59.000Z

    Specifies the test methods for filling compounds of electric cables used with telecommunication equipment. Gives the methods for drop-point, separation of oil, lower temperature brittleness, total acid number, absence of corrosive components, permittivity at 23 °C, d.c. resistivity at 23°C and 100°C.

  20. Failing softly: A fracture theory of highly-deformable materials

    E-Print Network [OSTI]

    Tamar Goldman Boué; Roi Harpaz; Jay Fineberg; Eran Bouchbinder

    2015-03-24T23:59:59.000Z

    Highly-deformable materials, from synthetic hydrogels to biological tissues, are becoming increasingly important from both fundamental and practical perspectives. Their mechanical behaviors, in particular the dynamics of crack propagation during failure, are not yet fully understood. Here we propose a theoretical framework for the dynamic fracture of highly-deformable materials, in which the effects of a dynamic crack are treated with respect to the nonlinearly deformed (pre-stressed/strained), non-cracked, state of the material. Within this framework, we derive analytic and semi-analytic solutions for the near-tip deformation fields and energy release rates of dynamic cracks propagating in incompressible neo-Hookean solids under biaxial and uniaxial loading. We show that moderately large pre-stressing has a marked effect on the stress fields surrounding a crack's tip. We verify these predictions by performing extensive experiments on the fracture of soft brittle elastomers over a range of loading levels and propagation velocities, showing that the newly developed framework offers significantly better approximations to the measurements than standard approaches at moderately large levels of external loadings and high propagation velocities. This framework should be relevant to the failure analysis of soft and tough, yet brittle, materials.

  1. Crack-based analysis of concrete with brittle reinforcement

    E-Print Network [OSTI]

    Burgoyne, Chris

    { FaberMaunsell Ltd; University of Cambridge Brittle reinforcement (such as fibre-reinforced plastic to the surround- ing concrete, at a crack surface sL=sR s on the left/right side of a crack u increase in unbonded

  2. Transport and Failure in Li-ion Batteries | Stanford Synchrotron...

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

    is well predicted by the macrohomogeneous model of Newman and co-workers, predicting degradation and failure remains a challenge. It may be that, like most materials, failure...

  3. Brittle Failure Design Criteria for Ductile Cast Iron Spent-Fuel

    Office of Scientific and Technical Information (OSTI)

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItem Not Found Item Not Found The itemAIR SEPARATION

  4. Air-Cooled Stack Freeze Tolerance Freeze Failure Modes and Freeze Tolerance Strategies for GenDriveTM Material Handling Application Systems and Stacks Final Scientific Report

    SciTech Connect (OSTI)

    Hancock, David, W.

    2012-02-14T23:59:59.000Z

    Air-cooled stack technology offers the potential for a simpler system architecture (versus liquid-cooled) for applications below 4 kilowatts. The combined cooling and cathode air allows for a reduction in part count and hence a lower cost solution. However, efficient heat rejection challenges escalate as power and ambient temperature increase. For applications in ambient temperatures below freezing, the air-cooled approach has additional challenges associated with not overcooling the fuel cell stack. The focus of this project was freeze tolerance while maintaining all other stack and system requirements. Through this project, Plug Power advanced the state of the art in technology for air-cooled PEM fuel cell stacks and related GenDrive material handling application fuel cell systems. This was accomplished through a collaborative work plan to improve freeze tolerance and mitigate freeze-thaw effect failure modes within innovative material handling equipment fuel cell systems designed for use in freezer forklift applications. Freeze tolerance remains an area where additional research and understanding can help fuel cells to become commercially viable. This project evaluated both stack level and system level solutions to improve fuel cell stack freeze tolerance. At this time, the most cost effective solutions are at the system level. The freeze mitigation strategies developed over the course of this project could be used to drive fuel cell commercialization. The fuel cell system studied in this project was Plug Power's commercially available GenDrive platform providing battery replacement for equipment in the material handling industry. The fuel cell stacks were Ballard's commercially available FCvelocity 9SSL (9SSL) liquid-cooled PEM fuel cell stack and FCvelocity 1020ACS (Mk1020) air-cooled PEM fuel cell stack.

  5. Hydrodynamic effects of eroded materials on response of plasma-facing component during a tokamak disruption

    SciTech Connect (OSTI)

    Hassanein, A.; Konkashbaev, I.

    1999-10-25T23:59:59.000Z

    Loss of plasma confinement causes surface and structural damage to plasma-facing materials (PFMs) and remains a major obstacle for tokamak reactors. The deposited plasma energy results in surface erosion and structural failure. The surface erosion consists of vaporization, spallation, and liquid splatter of metallic materials, while the structural damage includes large temperature increases in structural materials and at the interfaces between surface coatings and structural members. Comprehensive models (contained in the HEIGHTS computer simulation package) are being used self-consistently to evaluate material damage. Splashing mechanisms occur as a result of volume bubble boiling and liquid hydrodynamic instabilities and brittle destruction mechanisms of nonmelting materials. The effect of macroscopic erosion on total mass losses and lifetime is evaluated. The macroscopic erosion products may further protect PFMs from severe erosion (via the droplet-shielding effect) in a manner similar to that of the vapor shielding concept.

  6. Theory and models of material erosion and lifetime during plasma instabilities in a tokamak environment.

    SciTech Connect (OSTI)

    Hassanein, A.; Konkashbaev, I.

    1999-11-08T23:59:59.000Z

    Surface and structural damage to plasma-facing components (PFCs) due to the frequent loss of plasma confinement remains a serious problem for the tokamak reactor concept. The deposited plasma energy causes significant surface erosion, possible structural failure, and frequent plasma contamination. Surface damage consists of vaporization, spallation, and liquid splatter of metallic materials. Structural damage includes large temperature increases in structural materials and at the interfaces between surface coatings and structural members. To evaluate the lifetimes of plasma-facing materials and nearby components and to predict the various forms of damage that they experience, comprehensive models (contained in the HEIGHTS computer simulation package) are developed, integrated self-consistently, and enhanced. Splashing mechanisms such as bubble boiling and various liquid magnetohydrodynamic instabilities and brittle destruction mechanisms of nonmelting materials are being examined. The design requirements and implications of plasma-facing and nearby components are discussed, along with recommendations to mitigate and reduce the effects of plasma instabilities on reactor components.

  7. Neutron irradiation effects on the ductile-brittle transition of ferritic/martensitic steels

    SciTech Connect (OSTI)

    Klueh, R.L.; Alexander, D.J.

    1997-06-01T23:59:59.000Z

    Ferritic/martensitic steels such as the conventional 9Cr-1MoVNb (Fe-9Cr-1Mo-0.25V-0.06Nb-0.1C) and 12Cr-1MoVW (Fe-12Cr-1Mo-0.25V-0.5W-0.5Ni-0.2C) steels have been considered potential structural materials for future fusion power plants. The major obstacle to their use is embrittlement caused by neutron irradiation. Observations on this irradiation embrittlement will be reviewed. Below 425-450{degrees}C, neutron irradiation hardens the steels. Hardening reduces ductility, but the major effect is an increase in the ductile-brittle transition temperature (DBTT) and a decrease in the upper-shelf energy, as measured by a Charpy impact test. After irradiation, DBTT values can increase to well above room temperature, thus increasing the chances of brittle rather than ductile fracture. In addition to irradiation hardening, neutrons from the fusion reaction will produce large amounts of helium in the steels used to construct fusion power plant components. Tests to simulate the fusion environment indicate that helium can also affect the toughness. Steels are being developed for fusion applications that have a low DBTT prior to irradiation and then show only a small shift after irradiation. A martensitic 9Cr-2WVTa (nominally Fe-9Cr-2W-0.25V-0.07Ta-0.1C) steel had a much lower DBTT than the conventional 9Cr-1MoVNb steel prior to neutron irradiation and showed a much smaller increase in DBTT after irradiation. 27 refs., 5 figs., 1 tab.

  8. Modeling the Ductile Brittle Fracture Transition in Reactor Pressure Vessel Steels using a Cohesive Zone Model based approach

    SciTech Connect (OSTI)

    Pritam Chakraborty; S. Bulent Biner

    2013-10-01T23:59:59.000Z

    Fracture properties of Reactor Pressure Vessel (RPV) steels show large variations with changes in temperature and irradiation levels. Brittle behavior is observed at lower temperatures and/or higher irradiation levels whereas ductile mode of failure is predominant at higher temperatures and/or lower irradiation levels. In addition to such temperature and radiation dependent fracture behavior, significant scatter in fracture toughness has also been observed. As a consequence of such variability in fracture behavior, accurate estimates of fracture properties of RPV steels are of utmost importance for safe and reliable operation of reactor pressure vessels. A cohesive zone based approach is being pursued in the present study where an attempt is made to obtain a unified law capturing both stable crack growth (ductile fracture) and unstable failure (cleavage fracture). The parameters of the constitutive model are dependent on both temperature and failure probability. The effect of irradiation has not been considered in the present study. The use of such a cohesive zone based approach would allow the modeling of explicit crack growth at both stable and unstable regimes of fracture. Also it would provide the possibility to incorporate more physical lower length scale models to predict DBT. Such a multi-scale approach would significantly improve the predictive capabilities of the model, which is still largely empirical.

  9. Scaling of structural failure

    SciTech Connect (OSTI)

    Bazant, Z.P. [Northwestern Univ., Evanston, IL (United States); Chen, Er-Ping [Sandia National Lab., Albuquerque, NM (United States)

    1997-01-01T23:59:59.000Z

    This article attempts to review the progress achieved in the understanding of scaling and size effect in the failure of structures. Particular emphasis is placed on quasibrittle materials for which the size effect is complicated. Attention is focused on three main types of size effects, namely the statistical size effect due to randomness of strength, the energy release size effect, and the possible size effect due to fractality of fracture or microcracks. Definitive conclusions on the applicability of these theories are drawn. Subsequently, the article discusses the application of the known size effect law for the measurement of material fracture properties, and the modeling of the size effect by the cohesive crack model, nonlocal finite element models and discrete element models. Extensions to compression failure and to the rate-dependent material behavior are also outlined. The damage constitutive law needed for describing a microcracked material in the fracture process zone is discussed. Various applications to quasibrittle materials, including concrete, sea ice, fiber composites, rocks and ceramics are presented.

  10. Materials Science and Engineering A, 2011, 528(1-2): p. 7596 7605 High strain rate compressive response ofsyntactic foams: trends in mechanical properties and failure mechanisms

    E-Print Network [OSTI]

    Gupta, Nikhil

    comprising hollow particles dispersed in a matrix material. Available studies on high strain rate compressive with respect to the material composition. Syntactic foams reinforced with micro- and nano-sized fibers are a class of porous materials in which thin-walled hollow particles are dispersed in a matrix material

  11. HYDROGEN EMBRITTLEMENT OF METALS: A PRIMER FOR THE FAILURE ANALYST

    SciTech Connect (OSTI)

    Louthan, M

    2008-01-31T23:59:59.000Z

    Hydrogen reduces the service life of many metallic components. Such reductions may be manifested as blisters, as a decrease in fatigue resistance, as enhanced creep, as the precipitation of a hydride phase and, most commonly, as unexpected, macroscopically brittle failure. This unexpected, brittle fracture is commonly termed hydrogen embrittlement. Frequently, hydrogen embrittlement occurs after the component has been is service for a period of time and much of the resulting fracture surface is distinctly intergranular. Many failures, particularly of high strength steels, are attributed to hydrogen embrittlement simply because the failure analyst sees intergranular fracture in a component that served adequately for a significant period of time. Unfortunately, simply determining that a failure is due to hydrogen embrittlement or some other form of hydrogen induced damage is of no particular help to the customer unless that determination is coupled with recommendations that provide pathways to avoid such damage in future applications. This paper presents qualitative and phenomenological descriptions of the hydrogen damage processes and outlines several metallurgical recommendations that may help reduce the susceptibility of a particular component or system to the various forms of hydrogen damage.

  12. A scalable computational approach for modeling dynamic fracture of brittle solids in three dimensions

    E-Print Network [OSTI]

    Seagraves, Andrew Nathan

    2010-01-01T23:59:59.000Z

    In this thesis a new parallel computational method is proposed for modeling threedimensional dynamic fracture of brittle solids. The method is based on a combination of the discontinuous Galerkin (DG) formulation of the ...

  13. 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

  14. Definition of the Brittle-Ductile Transition in the Coso Geothermal...

    Open Energy Info (EERE)

    Brittle-Ductile Transition in the Coso Geothermal Field East-Central California USA Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Definition...

  15. Stability maps to predict anomalous ductility in B2 materials

    E-Print Network [OSTI]

    Sun, Ruoshi

    While most B2 materials are brittle, a new class of B2 (rare-earth) intermetallic compounds is observed to have large ductility. We analytically derive a necessary condition for ductility (dislocation motion) involving ...

  16. Synthesis and single crystal structure refinement of the one-layer hydrate of sodium brittle mica

    SciTech Connect (OSTI)

    Kalo, Hussein; Milius, Wolfgang [Lehrstuhl fuer Anorganische Chemie I, University of Bayreuth, D-95440 Bayreuth (Germany)] [Lehrstuhl fuer Anorganische Chemie I, University of Bayreuth, D-95440 Bayreuth (Germany); Braeu, Michael [BASF Construction Chemicals GmbH, 83308 Trostberg (Germany)] [BASF Construction Chemicals GmbH, 83308 Trostberg (Germany); Breu, Josef, E-mail: Josef.Breu@uni-bayreuth.de [Lehrstuhl fuer Anorganische Chemie I, University of Bayreuth, D-95440 Bayreuth (Germany)] [Lehrstuhl fuer Anorganische Chemie I, University of Bayreuth, D-95440 Bayreuth (Germany)

    2013-02-15T23:59:59.000Z

    A sodium brittle mica with the ideal composition [Na{sub 4}]{sup inter}[Mg{sub 6}]{sup oct}[Si{sub 4}Al{sub 4}]{sup tet}O{sub 20}F{sub 4} was synthesized via melt synthesis in a gas tight crucible. This mica is unusual inasmuch as the known mica structure holds only room for two interlayer cations per unit cell and inasmuch as it readily hydrates despite the high layer charge while ordinary micas and brittle micas are non-swelling. The crystal structure of one-layer hydrate sodium brittle mica was determined and refined from single crystal X-ray data. Interlayer cations reside at the center of the distorted hexagonal cavities and are coordinated by the three inner basal oxygen atoms. The coordination of the interlayer cation is completed by three interlayer water molecules residing at the center of the interlayer region. The relative position of adjacent 2:1-layers thus is fixed by these octahedrally coordinated interlayer cations. Pseudo-symmetry leads to extensive twinning. In total five twin operations generate the same environment for the interlayer species and are energetically degenerate. - Graphical abstract: The sodium brittle mica has been successfully synthesized by melt synthesis and the crystal structure of the one-layer hydrate of sodium brittle mica was determined from single crystal X-ray diffraction data. Highlights: Black-Right-Pointing-Pointer Melt synthesis yielded coarse grained sodium brittle mica which showed little disorder. Black-Right-Pointing-Pointer Sodium brittle mica hydrated completely to the state of one-layer hydrate. Black-Right-Pointing-Pointer Structure of one-layer hydrate of sodium brittle mica could therefore be determined and refined. Black-Right-Pointing-Pointer Arrangement of upper and lower tetrahedral sheet encompassing interlayer cation were clarified.

  17. Defect induced plasticity and failure mechanism of boron nitride nanotubes under tension

    SciTech Connect (OSTI)

    Anoop Krishnan, N. M., E-mail: anoopnm@civil.iisc.ernet.in; Ghosh, Debraj [Indian Institute of Science, Bangalore 560012 (India)

    2014-07-28T23:59:59.000Z

    The effects of Stone-Wales (SW) and vacancy defects on the failure behavior of boron nitride nanotubes (BNNTs) under tension are investigated using molecular dynamics simulations. The Tersoff-Brenner potential is used to model the atomic interaction and the temperature is maintained close to 300?K. The effect of a SW defect is studied by determining the failure strength and failure mechanism of nanotubes with different radii. In the case of a vacancy defect, the effect of an N-vacancy and a B-vacancy is studied separately. Nanotubes with different chiralities but similar diameter is considered first to evaluate the chirality dependence. The variation of failure strength with the radius is then studied by considering nanotubes of different diameters but same chirality. It is observed that the armchair BNNTs are extremely sensitive to defects, whereas the zigzag configurations are the least sensitive. In the case of pristine BNNTs, both armchair and zigzag nanotubes undergo brittle failure, whereas in the case of defective BNNTs, only the zigzag ones undergo brittle failure. An interesting defect induced plastic behavior is observed in defective armchair BNNTs. For this nanotube, the presence of a defect triggers mechanical relaxation by bond breaking along the closest zigzag helical path, with the defect as the nucleus. This mechanism results in a plastic failure.

  18. Failure Analysis of Ceramic Components

    SciTech Connect (OSTI)

    B.W. Morris

    2000-06-29T23:59:59.000Z

    Ceramics are being considered for a wide range of structural applications due to their low density and their ability to retain strength at high temperatures. The inherent brittleness of monolithic ceramics requires a departure from the deterministic design philosophy utilized to analyze metallic structural components. The design program ''Ceramic Analysis and Reliability Evaluation of Structures Life'' (CARES/LIFE) developed by NASA Lewis Research Center uses a probabilistic approach to predict the reliability of monolithic components under operational loading. The objective of this study was to develop an understanding of the theories used by CARES/LIFE to predict the reliability of ceramic components and to assess the ability of CARES/LIFE to accurately predict the fast fracture behavior of monolithic ceramic components. A finite element analysis was performed to determine the temperature and stress distribution of a silicon carbide O-ring under diametral compression. The results of the finite element analysis were supplied as input into CARES/LIFE to determine the fast fracture reliability of the O-ring. Statistical material strength parameters were calculated from four-point flexure bar test data. The predicted reliability showed excellent correlation with O-ring compression test data indicating that the CARES/LIFE program can be used to predict the reliability of ceramic components subjected to complicated stress states using material properties determined from simple uniaxial tensile tests.

  19. Materials

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

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |IsLove Your Home andDisposition | NationalMaterials

  20. 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.

  1. Brittleness and Bayesian Inference | SciTech Connect

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

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office511041clothAdvanced Materials Advanced Materials FindAdvanced MaterialsDepartmentBrinkman Addresses

  2. Elastic-Plastic-Brittle Transitions and Avalanches in Disordered Media Sohan Kale and Martin Ostoja-Starzewski*

    E-Print Network [OSTI]

    Ostoja-Starzewski, Martin

    Elastic-Plastic-Brittle Transitions and Avalanches in Disordered Media Sohan Kale and Martin Ostoja to simulate elastic-plastic-brittle transitions in a disordered medium is presented. The model is based, and the fracture surfaces. The model demonstrates a plastic strain avalanche behavior for perfectly plastic as well

  3. Modeling of crack tip high inertia zone in dynamic brittle fracture

    E-Print Network [OSTI]

    Karedla-Ravi, Shankar

    2007-09-17T23:59:59.000Z

    of the domain. It was observed that crack propagated in three phases with a speed of 0.35cR before branching, which are in good agreement with experimental observations. Thus, modeling of high inertia zone is one of the key aspects to understanding brittle...

  4. Use of a nanoindentation fatigue test to characterize the ductile-brittle transition

    E-Print Network [OSTI]

    Boyer, Edmond

    on CaCO3 polycrystalline samples produce cumulative mechanical damage. It is also shown (C), Plasticity (C), Milling (A), Ductile-Brittle transition 1. Introduction Calcium carbonate (CaCO3 agglomerate, as they are more sensitive to attractive forces than bigger ones; 2. CaCO3 grain size

  5. SYNTHETIC SLING FAILURE - EVALUATIONS & RECOMMENDATIONS

    SciTech Connect (OSTI)

    MACKEY TC; HENDERSON CS

    2009-10-26T23:59:59.000Z

    The information and evaluations provided in this report were compiled to address the recurring problem of synthetic sling failure. As safety is the number one priority in all work aspects, a solution must be devised to prevent accidents from occurring. A total of thirteen cases regarding synthetic sling failure were evaluated in order to determine their causes, effects, and preventative measures. From the collected data, it was found that all cases in which the synthetic sling contacted the edge of its load resulted in sling failure. It is required that adequate synthetic sling protection devices be used to protect slings in any lift where the sling comes in direct contact with the edge or corner of its load. However, there are no consensus codes or standards stating the type, material, or purpose of the type of protective device used to protect the sling from being cut. Numerous industry standards and codes provide vague descriptions on how to protect synthetic slings. Without a clear, concise statement of how to protect synthetic slings, it is common for inadequate materials and sling protection devices to be used in an attempt to meet the intent of these requirements. The use of an inadequate sling protection device is the main cause of synthetic sling failure in all researched cases. Commercial sling protection devices come in many shapes and sizes, and have a variety of names, as well as advertised uses. 'Abrasion pads' and 'wear protectors' are two different names for products with the same intended purpose. There is no distinguishable way to determine the extent of sling protection which these devices will provide, or what specific scenarios they are made for. This creates room for error in a field where error is unacceptable. This report provides a recommended action for hoisting and rigging activities which require synthetic slings to contact a load, as well as recommended changes to industry standards which will benefit overall industry safety.

  6. Corrosion failures of austenitic stainless steel piping

    SciTech Connect (OSTI)

    Louthan, M.R. Jr.

    1993-10-01T23:59:59.000Z

    The safe and efficient operation of many chemical/industrial systems requires the continued integrity of the process piping; this is achieved through a complex series of interactions influenced by design, fabrication, construction, operation, inspection and lay-up requirements. Potential material-enviroment interactions are frequently, if evaluated at all, relegated to secondary considerations. This tendency virtually assures corrosion induced degradation of the process piping systems. Pitting, crevice attack, stress cracking, microbiologically influenced corrosion, intergranular attack and corrosion fatigue have caused leaks, cracks, failures and shutdown of numerous process systems. This paper uses the lessons learned from failure analysis to emphasize the importance of an integrated material program to system success. The necessity of continuing evaluation if also emphasized through examples of failures which were associated with materials-environment interactions caused by slight alterations of processes and/or systems.

  7. Research News Structured Porous Materials via Colloidal

    E-Print Network [OSTI]

    Velev, Orlin D.

    to Metals** By Orlin D. Velev* and Eric W. Kaler The formation of nanostructured materials by using applications in optical information processing and storage, advanced coatings, catalysis, and other emerging, dried colloidal crystals are very brittle and may disperse in water. Any practical device thus requires

  8. Numerical Modeling of Hydraulic Fracture Propagation Using Thermo-hydro-mechanical Analysis with Brittle Damage Model by Finite Element Method 

    E-Print Network [OSTI]

    Min, Kyoung

    2013-07-16T23:59:59.000Z

    are studied using a coupled thermo-hydro-mechanical (THM) analysis. The models are used to simulate microscopic and macroscopic fracture behaviors of laboratory-scale uniaxial and triaxial experiments on rock using an elastic/brittle damage model considering...

  9. Single crystal silicon as a macro-world structural material : application to compact, lightweight high pressure vessels

    E-Print Network [OSTI]

    Garza, Tanya Cruz

    2011-01-01T23:59:59.000Z

    Single crystal silicon has promising inherent structural properties which are attractive for weight sensitive applications. Single crystal silicon, however, is a brittle material which makes the usable strength that can ...

  10. Catalysinganenergyrevolution Nuclear Failures

    E-Print Network [OSTI]

    Laughlin, Robert B.

    extraction, fuel manufacture and management of spent fuel and waste. Currently, CEA is a large FrenchCatalysinganenergyrevolution France's Nuclear Failures The great illusion of nuclear energy greenpeace.org #12;Contents 2 Greenpeace International France's Nuclear Failures The French nuclear industry

  11. Novel approaches to multiscale modelling in materials science

    E-Print Network [OSTI]

    Elliott, James

    of nanocrystalline metals and alloys, crack propagation in brittle solids, polymer chain relaxation in nanocomposites, Materials modelling, Molecular dynamics, Monte Carlo, Finite element analysis, Hierarchical/hybrid models in polymer nanocomposites and the control of nucleation in biomimetic materials is also given. Many

  12. Coping with dependent failures in distributed systems

    E-Print Network [OSTI]

    Junqueira, Flavio

    2006-01-01T23:59:59.000Z

    Mosleh. Dependent failure analysis. Reliability engineeringIntrospective failure analysis: Avoiding correlated failuresThe analysis in [Kum91], however, assumes IID failures. The

  13. Fatigue failure in thin-film polysilicon is due to subcriticalcracking within the oxide layer

    SciTech Connect (OSTI)

    Alsem, D.H.; Muhlstein, C.L.; Stach, E.A.; Ritchie, R.O.

    2005-01-11T23:59:59.000Z

    It has been established that microelectromechanical systems (MEMS) created from polycrystalline silicon thin-films are subject to cyclic fatigue. Prior work by the authors has suggested that although bulk silicon is not susceptible to fatigue failure in ambient air, fatigue in micron-scale silicon is a result of a ''reaction-layer'' process, whereby high stresses induce a thickening of the post-release oxide at stress concentrations such as notches, which subsequently undergoes moisture-assisted cracking. However, there exists some controversy regarding the post-release oxide thickness of the samples used in the prior study. In this Letter, we present data from devices from a more recent fabrication run that confirm our prior observations. Additionally, new data from tests in high vacuum show that these devices do not fatigue when oxidation and moisture are suppressed. Each of these observations lends credence to the '''reaction-layer'' mechanism. Recent advances in the design of microelectromechanical systems (MEMS) have increased the demand for more reliable microscale structures. Although silicon is an effective and widely used structural material at the microscale, it is very brittle. Consequently, reliability is a limiting factor for commercial and defense applications. Since the surface to volume ratio of these structural films is very large, classical models for failure modes in bulk materials cannot always be applied. For example, whereas bulk silicon is immune to cyclic fatigue failure thin micron-scale structural films of silicon appear to be highly susceptible. It is clear that at these size scales, surface effects may become dominant in controlling mechanical properties. The main reliability issues for MEMS are stiction, fatigue and wear. Fatigue is important in cases where devices are subjected to a large number of loading cycles with amplitudes below their (single-cycle) fracture stress, which may arise due to vibrations intentionally induced in the structure (i.e. a resonator) or those which arise from the service environment. While the reliability of MEMS has received extensive attention, the physical mechanisms responsible for these failure modes have yet to be conclusively determined. This is particularly true for fatigue, where the mechanisms have been subject to intense debate. Recently we have proposed that the fatigue of micron-scale polysilicon is associated with stress-induced surface oxide thickening and moisture-assisted subcritical cracking in the amorphous SiO{sub 2} oxide layer (''reaction-layer'' fatigue). The mechanism of oxide thickening is as yet unknown, but is likely related to some form of stress-assisted diffusion. Allameh et al. suggest a complementary mechanism involving stress-assisted oxide thickening, caused by dissolution of the surface oxide which forms deep grooves that are sites for crack initiation. Kahn et al. have criticized these mechanisms and proposed that, instead, fatigue is caused by subcritical cracking due to contacting surface asperities in the compressive part of the cycle. To the authors' knowledge, there is no direct experimental observation of such asperity contact. Also, their model cannot explain why micron-scale silicon, and not bulk silicon, is susceptible to fatigue. Moreover, Kahn et al. do not acknowledge the role of stress-induced oxide thickening, which has been observed directly using TEM and indirectly using atomic-force microscope measurements by several investigators, and have questioned whether the materials utilized by Muhlstein et al. and Allameh et al. were representative due to the relatively thick oxide scales. Accordingly, the goal of the present research is to seek a definitive understanding of the physical mechanisms responsible for fatigue in polysilicon structural thin-films. Our approach is to combine on-chip testing methods with electron microscopy by fatiguing thin-film samples and observing them, in an unthinned condition, using high-voltage transmission electron microscopy (HVTEM). Two principal results are found from this work: (1

  14. ACC100 Crash Energy Management

    Broader source: Energy.gov (indexed) [DOE]

    failure mode New projects were initiated to investigate scale effects of brittle composite materials and to develop methods to predict insitu matrix properties of composites...

  15. alpha-mode containment failure: Topics by E-print Network

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

    Summary: of stainless steel container materials is a potential problem for long-term radioactive waste storage-to-failure of relevant stainless steels in the annealed...

  16. Salt diapirism with simultaneous brittle faulting and viscous flow ALEXEI N. B. POLIAKOV1-2,YURIYU. PODLADCHIKOV3, ETHAN CH. DAWSON4 &

    E-Print Network [OSTI]

    Podladchikov, Yuri

    Salt diapirism with simultaneous brittle faulting and viscous flow ALEXEI N. B. POLIAKOV1-2,YURIYU for the fxst time how sedimentaryrocks above a salt diapir can deform in either a brittle or a viscous way depending on the stress state and strain rates. Most existing models for salt tectonics incorporate only one

  17. Brittle Fracture in a 50Mo-50Re alloy in static tensile testing

    SciTech Connect (OSTI)

    Xu, Jianhui [University of Kentucky, Lexington; Kenik, Edward A [ORNL; Zhai, Tongguang [University of Kentucky, Lexington

    2008-01-01T23:59:59.000Z

    Tensile tests were conducted on 50Mo-50Re alloys, in fully-recrystallized and recovery heat-treated conditions respectively, at a very low strain rate of 10-6 s-1 and room temperature in air. It was found that both these alloys exhibited predominantly cleavage fracture with significant intergranular secondary cracking, compared to the predominantly ductile fracture found in the alloys at a higher strain rate. Cracks were often initiated at grain boundary triple junctions at the low strain rate. Electron back scatter diffraction (EBSD) measurements revealed significantly high misorientation gradients at grain boundaries, especially in the vicinity of some grain boundary triple junctions in the deformed alloys. Transmission electron microscopic (TEM) results verified the existence of significant misorientation taking place at grain boundaries in these alloys. Stress-assisted dynamic embrittlement, possibly due to trace interstitials, was the possible cause for the occurrence of brittle fracture in the 50Mo-50Re alloys at the low strain rate.

  18. A Unified Cohesive Zone Approach to Model Ductile Brittle Transition in Reactor Pressure Vessel Steels

    SciTech Connect (OSTI)

    Pritam Chakraborty; S. Bulent Biner

    2014-08-01T23:59:59.000Z

    In this study, a unified cohesive zone model has been proposed to predict, Ductile to Brittle Transition, DBT, in Reactor Pressure Vessel, RPV, steels. A general procedure is described to obtain the Cohesive Zone Model, CZM, parameters for the different temperatures and fracture probabilities. In order to establish the full master-curve, the procedure requires three calibration points with one at the upper-shelf for ductile fracture and two for the fracture probabilities, Pf, of 5% and 95% at the lower-shelf. In the current study, these calibrations were carried out by utilizing the experimental fracture toughness values and flow curves. After the calibration procedure, the simulations of fracture behavior (ranging from completely unstable to stable crack extension behavior) in one inch thick compact tension specimens at different temperatures yielded values that were comparable to the experimental fracture toughness values, indicating the viability of such unified modeling approach.

  19. Clay fabric intensity in natural and artificial fault gouges: Implications for brittle fault zone processes and sedimentary

    E-Print Network [OSTI]

    Clay fabric intensity in natural and artificial fault gouges: Implications for brittle fault zone processes and sedimentary basin clay fabric evolution Samuel H. Haines,1 Ben A. van der Pluijm,1 Matt J intensity measurements using X-ray texture goniometry on 22 natural clay-rich fault gouges from low

  20. A Fast Method for SRAM Failure Estimation

    E-Print Network [OSTI]

    Gao, Min

    2012-01-01T23:59:59.000Z

    thesis, a novel and fast failure analysis for SRAM cells isproposed algorithm for SRAM failure analysis is described inAlgorithm for SRAM Failure Analysis Input: random variables

  1. “Playboy Bunny” Sign of Congestive Heart Failure

    E-Print Network [OSTI]

    Hokama, Akira; Arakaki, Shingo; Shibata, Daisuke; Maeshiro, Tatsuji; Kinjo, Fukunori; Fujita, Jiro

    2011-01-01T23:59:59.000Z

    Bunny’’ Sign of Congestive Heart Failure Akira Hokama, MD*to evaluate congestive heart failure. We highlight ‘‘Playboycaused by congestive heart failure. [West J Emerg Med. 2011;

  2. Combination stem cell therapy for heart failure

    E-Print Network [OSTI]

    2010-01-01T23:59:59.000Z

    to further analyze his heart failure. Com- plete bloodA: Inflammatory markers in stable heart failure and theirof improvement and readmission in heart failure. Eur J Heart

  3. 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, ...

  4. Ris-R-1261(EN) Fatigue Degradation and Failure of

    E-Print Network [OSTI]

    . Such applications are for instance rotor blades in wind turbines, helicopter rotor blades, flywheels for energyRisø-R-1261(EN) Fatigue Degradation and Failure of Rotating Composite Structures ­ Materials Characterisation and Underlying Mechanisms E. Kristofer Gamstedt and Svend Ib Andersen Materials Research

  5. Steam generator tube failures

    SciTech Connect (OSTI)

    MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

    1996-04-01T23:59:59.000Z

    A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

  6. Geometric control of failure behavior in perforated sheets

    E-Print Network [OSTI]

    Michelle M. Driscoll

    2014-11-20T23:59:59.000Z

    Adding perforations to a continuum sheet allows new modes of deformation, and thus modifies its elastic behavior. The failure behavior of such a perforated sheet is explored, using a model experimental system: a material containing a one-dimensional array of rectangular holes. In this model system, a transition in failure mode occurs as the spacing and aspect ratio of the holes are varied: rapid failure via a running crack is completely replaced by quasi-static failure which proceeds via the breaking of struts at random positions in the array of holes. I demonstrate that this transition can be connected to the loss of stress enhancement which occurs as the material geometry is modified.

  7. Early detection of critical material degradation by means of electromagnetic multi-parametric NDE

    SciTech Connect (OSTI)

    Szielasko, Klaus; Tschuncky, Ralf; Rabung, Madalina; Altpeter, Iris; Dobmann, Gerd [Fraunhofer Institute for Nondestructive Testing (IZFP), Campus E3 1, 66123 Saarbrücken (Germany); Seiler, Georg; Herrmann, Hans-Georg; Boller, Christian [Fraunhofer Institute for Nondestructive Testing (IZFP), Campus E3 1, 66123 Saarbrücken, Germany and Saarland University, Chair of NDT and Quality Assurance, Campus E3 1, 66123 Saarbrücken (Germany)

    2014-02-18T23:59:59.000Z

    With an increasing number of power plants operated in excess of their original design service life an early recognition of critical material degradation in components will gain importance. Many years of reactor safety research allowed for the identification and development of electromagnetic NDE methods which detect precursors of imminent damage with high sensitivity, at elevated temperatures and in a radiation environment. Regarding low-alloy heat-resistant steel grade WB 36 (1.6368, 15NiCuMoNb5), effects of thermal and thermo-mechanical aging on mechanical-technological properties and several micromagnetic parameters have been thoroughly studied. In particular knowledge regarding the process of copper precipitation and its acceleration under thermo-mechanical load has been enhanced. Whilst the Cu-rich WB 36 steel is an excellent model material to study and understand aging effects related to neutron radiation without the challenge of handling radioactive specimens in a hot cell, actually neutron-irradiated reactor pressure vessel materials were investigated as well. The neutron fluence experienced and the resulting shift of the ductile-brittle transition temperature were determined electromagnetically, and it was shown that weld and base material can be distinguished from the cladded side of the RPV wall. Low-cycle fatigue of the austenitic stainless steel AISI 347 (1.4550, X6CrNiNb18-10) has been characterized with electromagnetic acoustic transducers (EMATs) at temperatures of up to 300 °C. Time-of-flight and amplitude of the transmitted ultrasound signal were evaluated against the number of load cycles applied and observed as an indication of the imminent material failure significantly earlier than monitoring stresses or strains.

  8. Hybrid sol-gel optical materials

    DOE Patents [OSTI]

    Zeigler, John M. (Albuquerque, NM)

    1993-01-01T23:59:59.000Z

    Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.

  9. Hybrid sol-gel optical materials

    DOE Patents [OSTI]

    Zeigler, J.M.

    1993-04-20T23:59:59.000Z

    Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.

  10. Hybrid sol-gel optical materials

    DOE Patents [OSTI]

    Zeigler, John M. (Albuquerque, NM)

    1992-01-01T23:59:59.000Z

    Hybrid sol-gel materials comprise silicate sols cross-linked with linear polysilane, polygermane, or poly(silane-germane). The sol-gel materials are useful as optical identifiers in tagging and verification applications and, in a different aspect, as stable, visible light transparent non-linear optical materials. Methyl or phenyl silicones, polyaryl sulfides, polyaryl ethers, and rubbery polysilanes may be used in addition to the linear polysilane. The linear polymers cross-link with the sol to form a matrix having high optical transparency, resistance to thermooxidative aging, adherence to a variety of substrates, brittleness, and a resistance to cracking during thermal cycling.

  11. 20`eme Congr`es Francais de Mecanique Besancon, 29 ao^ut au 2 septembre 2011 Extension of Beremin model to bi-modal brittle failure

    E-Print Network [OSTI]

    Boyer, Edmond

    . [8-10] in a large test program led at EDF on CT25 specimens taken from a nozzle shell of a nuclear leads to both abnormally low values of the fracture toughness and large scatter in test results toughness, KJC, and abnormally large scatter in KJC measurements can be met when testing CT specimens taken

  12. Failure Atlas for Rolling Bearings in Wind Turbines

    SciTech Connect (OSTI)

    Tallian, T. E.

    2006-01-01T23:59:59.000Z

    This Atlas is structured as a supplement to the book: T.E. Tallian: Failure Atlas for Hertz Contact Machine Elements, 2nd edition, ASME Press New York, (1999). The content of the atlas comprises plate pages from the book that contain bearing failure images, application data, and descriptions of failure mode, image, and suspected failure causes. Rolling bearings are a critical component of the mainshaft system, gearbox and generator in the rapidly developing technology of power generating wind turbines. The demands for long service life are stringent; the design load, speed and temperature regimes are demanding and the environmental conditions including weather, contamination, impediments to monitoring and maintenance are often unfavorable. As a result, experience has shown that the rolling bearings are prone to a variety of failure modes that may prevent achievement of design lives. Morphological failure diagnosis is extensively used in the failure analysis and improvement of bearing operation. Accumulated experience shows that the failure appearance and mode of failure causation in wind turbine bearings has many distinguishing features. The present Atlas is a first effort to collect an interpreted database of specifically wind turbine related rolling bearing failures and make it widely available. This Atlas is structured as a supplement to the book: T. E. Tallian: Failure Atlas for Hertz Contact Machine Elements, 2d edition, ASME Press New York, (1999). The main body of that book is a comprehensive collection of self-contained pages called Plates, containing failure images, bearing and application data, and three descriptions: failure mode, image and suspected failure causes. The Plates are sorted by main failure mode into chapters. Each chapter is preceded by a general technical discussion of the failure mode, its appearance and causes. The Plates part is supplemented by an introductory part, describing the appearance classification and failure classification systems used, and by several indexes. The present Atlas is intended as a supplement to the book. It has the same structure but contains only Plate pages, arranged in chapters, each with a chapter heading page giving a short definition of the failure mode illustrated. Each Plate page is self contained, with images, bearing and application data, and descriptions of the failure mode, the images and the suspected causes. Images are provided in two resolutions: The text page includes 6 by 9 cm images. In addition, high resolution image files are attached, to be retrieved by clicking on their 'push pin' icon. While the material in the present Atlas is self-contained, it is nonetheless a supplement to the book and the complete interpretation of the terse image descriptions and of the system underlying the failure code presupposes familiarity with the book. Since this Atlas is a supplement to the book, its chapter numbering follows that of the book. Not all failure modes covered in the book have been found among the observed wind turbines. For that reason, and because of the omission of introductory matter, the chapter numbers in this Atlas are not a continuous sequence.

  13. Failure modes at room and elevated temperatures. Technical report

    SciTech Connect (OSTI)

    Braun, L.M.

    1995-04-01T23:59:59.000Z

    Successful development of reliable ceramic composites will depend on an understanding of matrix cracking and damage mechanisms in these materials. Therefore, the objective of the Failure Models subtask is to investigate failure and damage mechanisms in fiber reinforced ceramic composites. Issues such as how fiber coatings, the fiber/matrix interface, residual stresses, and fiber volume fraction affect frictional stresses, fiber debonding, fiber pull-out and failure modes will be examined. The effect of these microstructural parameters on matrix crack initiation, propagation and damage will also be determined. The resulting observations and measurements data will be used to develop theoretical models for damage mechanisms in fiber reinforced composites. This report presents results concerning the effect of temperature on the failure modes of continuous fiber ceramic composites performed during the last quarter of FY 1993 and FY 1994. The Raman stress measurements and calculations were performed during the last quarter of FY 1994 and the first quarter of FY 1995.

  14. FRACTURE FAILURE CRITERIA OF SOFC PEN STRUCTURE

    SciTech Connect (OSTI)

    Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.; Qu, Jianmin

    2007-04-30T23:59:59.000Z

    Thermal stresses and warpage of the PEN are unavoidable due to the temperature changes from the stress-free sintering temperature to room temperature and mismatch of the coefficients of thermal expansion (CTE) of various layers in the PEN structures of solid oxide fuel cells (SOFC) during the PEN manufacturing process. In the meantime, additional mechanical stresses will also be created by mechanical flattening during the stack assembly process. The porous nature of anode and cathode in the PEN structures determines presence of the initial flaws and crack on the interfaces of anode/electrolyte/cathode and in the interior of the materials. The sintering/assembling induced stresses may cause the fracture failure of PEN structure. Therefore, fracture failure criteria for SOFC PEN structures is developed in order to ensure the structural integrity of the cell and stack of SOFC. In this paper, the fracture criteria based on the relationship between the critical energy release rate and critical curvature and maximum displacement of the warped cells caused by the temperature changes as well as mechanical flattening process is established so that possible failure of SOFC PEN structures may be predicted deterministically by the measurement of the curvature and displacement of the warped cells.

  15. Experimental study of the transition from brittle shear fractures to joints

    E-Print Network [OSTI]

    Ramsey, Jonathan Michael

    2003-01-01T23:59:59.000Z

    and Cosgrove, 1990; Engelder, 1999). In 1934, Leon observed that the empirical Coulomb-Mohr failure envelope is parabolic in shape (i. e. concave to the normal stress axis). In geology, many experimental studies (e. g. , Handin and Hager, 1957; Price, 1958... research is to characterize the transition &om Coulomb shear &acturing to tensile jointing through experimental rock deformation. Such a study will answer two fundamental questions: 1. ) Do hybrid &actures exist? 2. ) What is the character...

  16. Modeling brittle fracture, slip weakening, and variable friction in geomaterials with an embedded strong discontinuity finite element.

    SciTech Connect (OSTI)

    Regueiro, Richard A. (University of Colorado, Boulder, CO); Borja, R. I. (Stanford University, Stanford, CA); Foster, C. D. (Stanford University, Stanford, CA)

    2006-10-01T23:59:59.000Z

    Localized shear deformation plays an important role in a number of geotechnical and geological processes. Slope failures, the formation and propagation of faults, cracking in concrete dams, and shear fractures in subsiding hydrocarbon reservoirs are examples of important effects of shear localization. Traditional engineering analyses of these phenomena, such as limit equilibrium techniques, make certain assumptions on the shape of the failure surface as well as other simplifications. While these methods may be adequate for the applications for which they were designed, it is difficult to extrapolate the results to more general scenarios. An alternative approach is to use a numerical modeling technique, such as the finite element method, to predict localization. While standard finite elements can model a wide variety of loading situations and geometries quite well, for numerical reasons they have difficulty capturing the softening and anisotropic damage that accompanies localization. By introducing an enhancement to the element in the form of a fracture surface at an arbitrary position and orientation in the element, we can regularize the solution, model the weakening response, and track the relative motion of the surfaces. To properly model the slip along these surfaces, the traction-displacement response must be properly captured. This report focuses on the development of a constitutive model appropriate to localizing geomaterials, and the embedding of this model into the enhanced finite element framework. This modeling covers two distinct phases. The first, usually brief, phase is the weakening response as the material transitions from intact continuum to a body with a cohesionless fractured surface. Once the cohesion has been eliminated, the response along the surface is completely frictional. We have focused on a rate- and state-dependent frictional model that captures stable and unstable slip along the surface. This model is embedded numerically into the element using a generalized trapezoidal formulation. While the focus is on the constitutive model of interest, the framework is also developed for a general surface response. This report summarizes the major research and development accomplishments for the LDRD project titled 'Cohesive Zone Modeling of Failure in Geomaterials: Formulation and Implementation of a Strong Discontinuity Model Incorporating the Effect of Slip Speed on Frictional Resistance'. This project supported a strategic partnership between Sandia National Laboratories and Stanford University by providing funding for the lead author, Craig Foster, during his doctoral research.

  17. Autonomous thruster failure recovery for underactuated spacecraft

    E-Print Network [OSTI]

    Pong, Christopher Masaru

    2010-01-01T23:59:59.000Z

    Thruster failures historically account for a large percentage of failures that have occurred on orbit. Therefore, autonomous thruster failure detection, isolation, and recovery (FDIR) is an essential component to any robust ...

  18. FAILURE DATA ANALYSIS OF THE SUPERHILAC RADIO FREQUENCY SUBSYSTEM

    E-Print Network [OSTI]

    Chang, Mark K.

    2012-01-01T23:59:59.000Z

    Applications to Failure Data Analysis," in RELIABILITY ANDLBL-8631 FAILURE DATA ANALYSIS OF THE SUPERHILAC RADIOinterest in our failure data analysis. If the failure rate

  19. A simple approach to modeling ductile failure.

    SciTech Connect (OSTI)

    Wellman, Gerald William

    2012-06-01T23:59:59.000Z

    Sandia National Laboratories has the need to predict the behavior of structures after the occurrence of an initial failure. In some cases determining the extent of failure, beyond initiation, is required, while in a few cases the initial failure is a design feature used to tailor the subsequent load paths. In either case, the ability to numerically simulate the initiation and propagation of failures is a highly desired capability. This document describes one approach to the simulation of failure initiation and propagation.

  20. TREE FAILURES AND ACCIDENTS IN

    E-Print Network [OSTI]

    Standiford, Richard B.

    .DEPARTMENT O F AGRICULTURE GENERAL TECHNICAL REPORT PSW- 24 #12;TREE FAILURES AND ACCIDENTS IN RECREATION are major concerns. Injuries, fatalities, and high property losses occur each year as a result of tree losses associated with public occupancy. Hazard reduction can limit such losses to predefined levels

  1. Shock-Induced Structural Phase Transition, Plasticity, and Brittle Cracks in Aluminum Nitride Ceramic

    E-Print Network [OSTI]

    Southern California, University of

    into an elastic wave and a slower SPT wave that transforms the wurtzite structure into the rocksalt phase into the wurtzite phase. Nanovoids coalesce into mode I cracks while dislocations give rise to kink bands and mode. Before impact, the crystal- line structure of the target material is wurtzite. The z axis, parallel

  2. Gradient damage models and their use to approximate brittle fracture Kim Phama,b, Hanen Amorc,, Jean-Jacques Marigod, Corrado Maurinia,b,

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Gradient damage models and their use to approximate brittle fracture Kim Phama,b, Hanen Amorc of gradient damage models. In the present paper, we first formulate the quasi-static evolution problem of damage. These concepts are applied in the particular setting of a one-dimensional traction test

  3. Real-Time Quantitative Imaging of Failure Events in Materials...

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

    Monday, 25 March 2013 00:00 Gathering information on the evolution of small cracks in ceramic matrix composites used in hostile environments such as in gas turbines and...

  4. Porous Materials Porous Materials

    E-Print Network [OSTI]

    Berlin,Technische Universität

    1 Porous Materials x Porous Materials · Physical properties * Characteristic impedance p = p 0 e -jk xa- = vej[ ] p x - j ; Zc= p ve = c ka 0k = c 1-j #12;2 Porous Materials · Specific acoustic impedance Porous Materials · Finite thickness ­ blocked p e + -jk (x-d)a p e - jk (x-d)a d x #12

  5. Optimization Online - Constraint Qualification Failure in Second ...

    E-Print Network [OSTI]

    Hassan L. Hijazi

    2014-07-22T23:59:59.000Z

    Jul 22, 2014 ... ... Qualification Failure in Second-Order Cone Formulations of Unbounded Disjunctions" Technical Report - NICTA, Canberra ACT Australia, ...

  6. Abduction Compared with Negation by Failure

    E-Print Network [OSTI]

    Koehn, Philipp

    Abduction Compared with Negation by Failure K. Eshghi * Hewlett Packard Laboratories programming can be extended to include abduction with integrity constraints. In the resulting extension for negation by failure, which generalises the stable model semantics of negation by failure. The abductive

  7. Failure prognostic by using Dynamic Bayesian Networks

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    to failures and their maintenance ex- pensive. To keep them in good operational conditions, maintenance to the ISO standard (ISO, 13381-1 (2004)), failure prognostic corresponds to the estimation of the operating presents a procedure for failure prognostic by using Dynamic Bayesian Networks (DBNs). The graphical

  8. GROUND PLANE INSULATION FAILURE IN THE FIRST TPC SUPERCONDUCTING COIL

    E-Print Network [OSTI]

    Green, M.A.

    2010-01-01T23:59:59.000Z

    is WIUUTEO GROUND PLANE INSULATION FAILURE IN THE FIRST TPCOn August 27, 1980, an insulation failure occurred dt-ringby a failure uf ground plane insulation. ACKNOWLEDGMENTS The

  9. Global Failure Criteria for SOFC Positive/Electrolyte/Negative (PEN) Structure

    SciTech Connect (OSTI)

    Liu, Wenning N.; Sun, Xin; Khaleel, Mohammad A.; Qu, Jianmin

    2007-04-01T23:59:59.000Z

    Due to the mismatch of thermal expansion coefficients (TEC) of the various layer materials in SOFC, the internal stresses are unavoidable under temperature differential. In order to create the reliable cell and stack of solid oxide fuel cell (SOFC), it is necessary to develop a failure criterion for SOFC PEN structures for the initial failures occurred during cell/stack assembly. In this paper, a global failure criterion is developed for the initial design against mechanical failure of the PEN structure in high temperature SOFCs. The relationship of the critical energy release rate and critical curvature and maximum displacement of the warpage of the cells caused by the temperature differential is established so that the failure reliability of SOFC PEN structures may be determined by the measurement of the curvature and displacement of the warpaged cells.

  10. Solar Thermal Reactor Materials Characterization

    SciTech Connect (OSTI)

    Lichty, P. R.; Scott, A. M.; Perkins, C. M.; Bingham, C.; Weimer, A. W.

    2008-03-01T23:59:59.000Z

    Current research into hydrogen production through high temperature metal oxide water splitting cycles has created a need for robust high temperature materials. Such cycles are further enhanced by the use of concentrated solar energy as a power source. However, samples subjected to concentrated solar radiation exhibited lifetimes much shorter than expected. Characterization of the power and flux distributions representative of the High Flux Solar Furnace(HFSF) at the National Renewable Energy Laboratory(NREL) were compared to ray trace modeling of the facility. In addition, samples of candidate reactor materials were thermally cycled at the HFSF and tensile failure testing was performed to quantify material degradation. Thermal cycling tests have been completed on super alloy Haynes 214 samples and results indicate that maximum temperature plays a significant role in reduction of strength. The number of cycles was too small to establish long term failure trends for this material due to the high ductility of the material.

  11. Contact method to allow benign failure in ceramic capacitor having self-clearing feature

    DOE Patents [OSTI]

    Myers, John D.; Taylor, Ralph S.

    2012-06-26T23:59:59.000Z

    A capacitor exhibiting a benign failure mode has a first electrode layer, a first ceramic dielectric layer deposited on a surface of the first electrode, and a second electrode layer disposed on the ceramic dielectric layer, wherein selected areas of the ceramic dielectric layer have additional dielectric material of sufficient thickness to exhibit a higher dielectric breakdown voltage than the remaining majority of the dielectric layer. The added thickness of the dielectric layer in selected areas allows lead connections to be made at the selected areas of greater dielectric thickness while substantially eliminating a risk of dielectric breakdown and failure at the lead connections, whereby the benign failure mode is preserved.

  12. Clinical Outcomes and Patterns of Failure After Intensity-Modulated Radiotherapy for Nasopharyngeal Carcinoma

    SciTech Connect (OSTI)

    Ng, Wai Tong, E-mail: ngwt1@ha.org.h [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Lee, Michael C.H. [Department of Medical Physics, Pamela Youde Nethersole Eastern Hospital (Hong Kong); Hung, Wai Man; Choi, Cheuk Wai; Lee, Kin Chung; Chan, Oscar S.H.; Lee, Anne W.M. [Department of Clinical Oncology, Pamela Youde Nethersole Eastern Hospital (Hong Kong)

    2011-02-01T23:59:59.000Z

    Purpose: To study and report the clinical outcomes and patterns of failure after intensity-modulated radiotherapy (IMRT) for nasopharyngeal carcinoma (NPC). Methods and Materials: The treatment outcomes of NPC patients treated with IMRT at Pamela Youde Nethersole Eastern Hospital between 2005 and 2007 were reviewed. The location and extent of locoregional failures were transferred to the pretreatment planning computed tomography for dosimetry analysis. Statistical analyses were performed on dose coverage and locoregional failures. Results: A total of 193 NPC patients were analyzed; 93% had Stage III/IV disease. Median follow-up was 30 months. Overall disease failure (at any site) developed in 35 patients. Among these, there were 23 distant metastases, 16 local failures, and 9 regional failures. Four of the locoregional failures were marginal. Dose conformity with IMRT was excellent. Patients with at least 66.5 Gy to their target volumes had significantly less locoregional failure. The 2-year local progression-free, regional progression-free, distant metastasis-free, and overall survival rates were 95%, 96%, 90%, and 92%, respectively. Conclusions: Intensity-modulated radiotherapy provides excellent locoregional control for NPC. Distant metastasis remains the most difficult challenge, and more effective systemic agents should be explored for patients presenting with advanced locoregional diseases.

  13. Modeling Stress Strain Relationships and Predicting Failure Probabilities For Graphite Core Components

    SciTech Connect (OSTI)

    Duffy, Stephen

    2013-09-09T23:59:59.000Z

    This project will implement inelastic constitutive models that will yield the requisite stress-strain information necessary for graphite component design. Accurate knowledge of stress states (both elastic and inelastic) is required to assess how close a nuclear core component is to failure. Strain states are needed to assess deformations in order to ascertain serviceability issues relating to failure, e.g., whether too much shrinkage has taken place for the core to function properly. Failure probabilities, as opposed to safety factors, are required in order to capture the bariability in failure strength in tensile regimes. The current stress state is used to predict the probability of failure. Stochastic failure models will be developed that can accommodate possible material anisotropy. This work will also model material damage (i.e., degradation of mechanical properties) due to radiation exposure. The team will design tools for components fabricated from nuclear graphite. These tools must readily interact with finite element software--in particular, COMSOL, the software algorithm currently being utilized by the Idaho National Laboratory. For the eleastic response of graphite, the team will adopt anisotropic stress-strain relationships available in COMSO. Data from the literature will be utilized to characterize the appropriate elastic material constants.

  14. A review of macroscopic ductile failure criteria.

    SciTech Connect (OSTI)

    Corona, Edmundo; Reedlunn, Benjamin

    2013-09-01T23:59:59.000Z

    The objective of this work was to describe several of the ductile failure criteria com- monly used to solve practical problems. The following failure models were considered: equivalent plastic strain, equivalent plastic strain in tension, maximum shear, Mohr- Coulomb, Wellman's tearing parameter, Johnson-Cook and BCJ MEM. The document presents the main characteristics of each failure model as well as sample failure predic- tions for simple proportional loading stress histories in three dimensions and in plane stress. Plasticity calculations prior to failure were conducted with a simple, linear hardening, J2 plasticity model. The resulting failure envelopes were plotted in prin- cipal stress space and plastic strain space, where the dependence on stress triaxiality and Lode angle are clearly visible. This information may help analysts select a ductile fracture model for a practical problem and help interpret analysis results.

  15. Failure analysis issues in microelectromechanical systems (MEMS).

    SciTech Connect (OSTI)

    Walraven, Jeremy Allen

    2005-07-01T23:59:59.000Z

    Failure analysis and device characterization of MEMS components are critical steps in understanding the root causes of failure and improving device performance. At the wafer and die level these tasks can be performed with little or no sample preparation. Larger challenges occur after fabrication when the device is packaged, capped, sealed, or otherwise obstructed from view. The challenges and issues of MEMS failure analysis lie in identifying the root cause of failure for these packaged, capped, and sealed devices without perturbing the device or its immediate environment. Novel methods of gaining access to the device or preparing the device for analysis are crucial to accurately determining the root cause of failure. This paper will discuss issues identified in performing root cause failure analysis of packaged MEMS devices, as well as the methods employed to analyze them.

  16. Light water reactor lower head failure analysis

    SciTech Connect (OSTI)

    Rempe, J.L.; Chavez, S.A.; Thinnes, G.L. [EG and G Idaho, Inc., Idaho Falls, ID (United States)] [and others

    1993-10-01T23:59:59.000Z

    This document presents the results from a US Nuclear Regulatory Commission-sponsored research program to investigate the mode and timing of vessel lower head failure. Major objectives of the analysis were to identify plausible failure mechanisms and to develop a method for determining which failure mode would occur first in different light water reactor designs and accident conditions. Failure mechanisms, such as tube ejection, tube rupture, global vessel failure, and localized vessel creep rupture, were studied. Newly developed models and existing models were applied to predict which failure mechanism would occur first in various severe accident scenarios. So that a broader range of conditions could be considered simultaneously, calculations relied heavily on models with closed-form or simplified numerical solution techniques. Finite element techniques-were employed for analytical model verification and examining more detailed phenomena. High-temperature creep and tensile data were obtained for predicting vessel and penetration structural response.

  17. An assessment of the state of the art in predicting the failure of ceramics: Final report

    SciTech Connect (OSTI)

    Boulet, J.A.M.

    1988-03-01T23:59:59.000Z

    The greatest weakness in existing design strategies for brittle fracture is in the narrow range of conditions for which the strategies are adequate. The primary reason for this weakness is the use of simplistic mechanical models of fracture processes and unverified statistical models of materials. To improve the design methodology, the models must first be improved. Specifically recommended research goals are: to develop models of cracks with realistic geometry under arbitrary stress states; to identify and model the most important relationships between fracture processes and microstructural features; to assess the technology available for acquiring statistical data on microstructure and flaw populations, and to establish the amount of data required for verification of statistical models; and to establish a computer-based fracture simulation that can incorporate a wide variety of mechanical and statistical models and crack geometries, as well as arbitrary stress states. 204 refs., 2 tabs.

  18. PREDICTION OF PROXIMAL FEMORAL FRACTURE BY USING MECHANICAL QUASI-BRITTLE DAMAGE COUPLED WITH ANISOTROPIC BEHAVIOUR LAW

    E-Print Network [OSTI]

    Boyer, Edmond

    : : denotes the strain at fracture given by: Results The predicted load-displacement curve based on Keyak et, and not on the prediction of failure propagation. The fracture load is determined as the load at which at least one solid and propagation. Until now, direct comparisons of predicted and measured force-displacement curves and complete

  19. Summary of failure analysis activities at Brookhaven National Laboratory

    SciTech Connect (OSTI)

    Cowgill, M.G.; Czajkowski, C.J.; Franz, E.M.

    1996-10-01T23:59:59.000Z

    Brookhaven National Laboratory has for many years conducted examinations related to the failures of nuclear materials and components. These examinations included the confirmation of root cause analyses, the determination of the causes of failure, identification of the species that accelerate corrosion, and comparison of the results of nondestructive examinations with those obtained by destructive examination. The results of those examinations, which had previously appeared in various formats (formal and informal reports, journal articles, etc.), have been collected together and summarized in the present report. The report is divided into sections according to the general subject matter (for example, corrosion, fatigue, etc.). Each section presents summaries of the information contained in specific reports and publications, all of which are fully identified as to title, authors, report number or journal reference, date of publication, and FIN number under which the work was performed.

  20. Addressing failures in exascale computing

    SciTech Connect (OSTI)

    Snir, Marc; Wisniewski, Robert W.; Abraham, Jacob A.; Adve, Sarita; Bagchi, Saurabh; Balaji, Pavan; Belak, Jim; Bose, Pradip; Cappello, Franck; Carlson, William; Chien, Andrew A.; Coteus, Paul; Debardeleben, Nathan A.; Diniz, Pedro; Engelmann, Christian; Erez, Mattan; Saverio, Fazzari; Geist, Al; Gupta, Rinku; Johnson, Fred; Krishnamoorthy, Sriram; Leyffer, Sven; Liberty, Dean; Mitra, Subhasish; Munson, Todd; Schreiber, Robert; Stearly, Jon; Van Hensbergen, Eric

    2014-05-01T23:59:59.000Z

    We present here a report produced by a workshop on “Addressing Failures in Exascale Computing” held in Park City, Utah, August 4–11, 2012. The charter of this workshop was to establish a common taxonomy about resilience across all the levels in a computing system; discuss existing knowledge on resilience across the various hardware and software layers of an exascale system; and build on those results, examining potential solutions from both a hardware and software perspective and focusing on a combined approach. The workshop brought together participants with expertise in applications, system software, and hardware; they came from industry, government, and academia; and their interests ranged from theory to implementation. The combination allowed broad and comprehensive discussions and led to this document, which summarizes and builds on those discussions.

  1. Addressing Failures in Exascale Computing

    SciTech Connect (OSTI)

    Snir, Marc [Argonne National Laboratory (ANL)] [Argonne National Laboratory (ANL); Wisniewski, Robert [Intel Corporation] [Intel Corporation; Abraham, Jacob [unknown] [unknown; Adve, Sarita [University of Illinois, Urbana-Champaign] [University of Illinois, Urbana-Champaign; Bagchi, Saurabh [Purdue University] [Purdue University; Balaji, Pavan [Argonne National Laboratory (ANL)] [Argonne National Laboratory (ANL); Belak, J. [Lawrence Livermore National Laboratory (LLNL)] [Lawrence Livermore National Laboratory (LLNL); Bose, Pradip [IBM T. J. Watson Research Center] [IBM T. J. Watson Research Center; Cappello, Franck [Argonne National Laboratory (ANL)] [Argonne National Laboratory (ANL); Carlson, Bill [unknown] [unknown; Chien, Andrew [University of Chicago] [University of Chicago; Coteus, Paul [IBM T. J. Watson Research Center] [IBM T. J. Watson Research Center; DeBardeleben, Nathan [Los Alamos National Laboratory (LANL)] [Los Alamos National Laboratory (LANL); Diniz, Pedro [University of Southern California] [University of Southern California; Engelmann, Christian [ORNL] [ORNL; Erez, Mattan [University of Texas at Austin] [University of Texas at Austin; Fazzari, Saverio [Booz Allen Hamilton] [Booz Allen Hamilton; Geist, Al [ORNL] [ORNL; Gupta, Rinku [Argonne National Laboratory (ANL)] [Argonne National Laboratory (ANL); Johnson, Fred [Science Applications International Corporation (SAIC), Oak Ridge, TN] [Science Applications International Corporation (SAIC), Oak Ridge, TN; Krishnamoorthy, Sriram [Pacific Northwest National Laboratory (PNNL)] [Pacific Northwest National Laboratory (PNNL); Leyffer, Sven [Argonne National Laboratory (ANL)] [Argonne National Laboratory (ANL); Liberty, Dean [AMD] [AMD; Mitra, Subhasish [Stanford University] [Stanford University; Munson, Todd [Argonne National Laboratory (ANL)] [Argonne National Laboratory (ANL); Schreiber, Rob [HP Labs] [HP Labs; Stearley, Jon [Sandia National Laboratories (SNL)] [Sandia National Laboratories (SNL); Van Hensbergen, Eric [ARM] [ARM

    2014-01-01T23:59:59.000Z

    We present here a report produced by a workshop on Addressing failures in exascale computing' held in Park City, Utah, 4-11 August 2012. The charter of this workshop was to establish a common taxonomy about resilience across all the levels in a computing system, discuss existing knowledge on resilience across the various hardware and software layers of an exascale system, and build on those results, examining potential solutions from both a hardware and software perspective and focusing on a combined approach. The workshop brought together participants with expertise in applications, system software, and hardware; they came from industry, government, and academia, and their interests ranged from theory to implementation. The combination allowed broad and comprehensive discussions and led to this document, which summarizes and builds on those discussions.

  2. CLINICAL RESEARCH Heart failure/cardiomyopathy

    E-Print Network [OSTI]

    Duncan, James S.

    RESEARCH Heart failure/cardiomyopathy Preserved left ventricular twist and circumferential deformation, but depressed longitudinal and radial deformation in patients with diastolic heart failure Jianwen Wang, Dirar SBakey Heart Center, The Methodist Hospital, Houston, TX 77030-2717, USA Received 27 September 2007; revised 15

  3. Finite Deformation of Materials with an Ensemble of Defects

    SciTech Connect (OSTI)

    J.K. Dienes

    2003-01-01T23:59:59.000Z

    The theory of large deformations developed here is closely related to continuum mechanics but it differs in several major respects, especially in considering the deformation associated with various types of physical behavior, making it possible to synthesize a general approach to formulating constitutive laws. One goal is to derive general concepts of strain, strain rate, stress, and stress rate that are somewhat more physics-based than in most standard works on continuum mechanics, and to demonstrate some new relations between these quantities. With these concepts it is possible to develop a generalized principle of superposition of strain rates (GSSR) that accounts for damage as well as plastic flow. The traditional superposition of strain rates allows for addition of elastic and plastic strain rates and is commonly thought to be valid only for small strains. The GSSR allows us to compute deformations involving plastic flow and, in addition, brittle failure, fragmentation, high-pressure effects and other types of behavior as necessary, and the theory is valid for arbitrarily large deformations. In fact, GSSR is derived from more basic ideas and has broader application than the standard superposition of strain rates. The physical basis for calculations of complex material response is developed in a separate report. The implementation into the SCRAM computer program is documented separately. The polar decomposition theorem is taken as a starting point for the theory of large deformation, an approach somewhat different from that usually taken in continuum mechanics. Two sets of orthogonal axes are distinguished, space axes that are fixed in ambient space, and polar axes that are related to material deformation. This clarifies several concepts; for example, it is shown that the Signorini and Green-St. Venant strains are actually measures of the same physical entity, one in space axes and the other in polar axes. It follows that they are not competing measures, as is often implied in traditional continuum mechanics. It also follows that Piola stress is a measure in polar axes, while Cauchy stress is a measure in space axes. Another consequence of polar decomposition is a proof that vorticity is not a measure of the rate of material rotation (as is often stated in the hydrodynamics literature) but that they are related. This allows us to develop an exact approach to computing rates of tensor quantities, called polar rates, that account for material rotation in an exact way. This leads to a simple relation between Signorini strain rate and stretching (the symmetric part of the velocity gradient). It also follows that the polar stress rate is the appropriate measure for the rate of change of Cauchy stress, and that the more traditional stress rate of Zaremba, Jaumann, and Noll is only an approximation, valid at small strains. Examples are described for materials undergoing simple shear, vortex motion, and torsion.

  4. MATERIALS CURRICULUM Major: Core Courses : 21 Credits

    E-Print Network [OSTI]

    Srinivasan, N.

    :0 Diffusion in Solids MT 225 3:0 Deformation and Failure Mechanisms at Elevated Temperatures MT 233 3, and nanotechnology. MT 101 3:0 January (4th Semester) Introduction to Materials Science Bonding, types of materials of structural characterization. Thermodynamics of solid solutions, phase diagrams, defects, diffusion

  5. Local Failure in Resected N1 Lung Cancer: Implications for Adjuvant Therapy

    SciTech Connect (OSTI)

    Higgins, Kristin A., E-mail: kristin.higgins@duke.edu [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Chino, Junzo P. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States); Berry, Mark [Department of Surgery, Division of Cardiovascular and Thoracic Surgery, Duke University Medical Center, Durham, NC (United States); Ready, Neal [Department of Medicine, Division of Medical Oncology, Duke University Medical Center, Durham, NC (United States); Boyd, Jessamy [US Oncology, Dallas, TX (United States); Yoo, David S.; Kelsey, Chris R. [Department of Radiation Oncology, Duke University Medical Center, Durham, NC (United States)

    2012-06-01T23:59:59.000Z

    Purpose: To evaluate actuarial rates of local failure in patients with pathologic N1 non-small-cell lung cancer and to identify clinical and pathologic factors associated with an increased risk of local failure after resection. Methods and Materials: All patients who underwent surgery for non-small-cell lung cancer with pathologically confirmed N1 disease at Duke University Medical Center from 1995-2008 were identified. Patients receiving any preoperative therapy or postoperative radiotherapy or with positive surgical margins were excluded. Local failure was defined as disease recurrence within the ipsilateral hilum, mediastinum, or bronchial stump/staple line. Actuarial rates of local failure were calculated with the Kaplan-Meier method. A Cox multivariate analysis was used to identify factors independently associated with a higher risk of local recurrence. Results: Among 1,559 patients who underwent surgery during the time interval, 198 met the inclusion criteria. Of these patients, 50 (25%) received adjuvant chemotherapy. Actuarial (5-year) rates of local failure, distant failure, and overall survival were 40%, 55%, and 33%, respectively. On multivariate analysis, factors associated with an increased risk of local failure included a video-assisted thoracoscopic surgery approach (hazard ratio [HR], 2.5; p = 0.01), visceral pleural invasion (HR, 2.1; p = 0.04), and increasing number of positive N1 lymph nodes (HR, 1.3 per involved lymph node; p = 0.02). Chemotherapy was associated with a trend toward decreased risk of local failure that was not statistically significant (HR, 0.61; p = 0.2). Conclusions: Actuarial rates of local failure in pN1 disease are high. Further investigation of conformal postoperative radiotherapy may be warranted.

  6. Nickel alloy stud bolts failure: A case history

    SciTech Connect (OSTI)

    Toffolo, G.; Fassina, P.; Marangoni, M. [AGIP SpA, Milan (Italy); Msallem, A. [AGIP Oil, Tripoli (Libyan Arab Jamahiriya)

    1996-12-01T23:59:59.000Z

    High strength and corrosion resistance material as Inconel X-750 has been selected for the seal flange bolts in an off-shore field in Libya, due to its properties at high temperature, needed for compliance with Fire Safe requirements. After 4 years from the production start-up, during a routine maintenance of wellheads, some bolts have been found cracked. The paper deals with all the activities done in order to understand the cause of the failure. In particular failure analysis has been carried out through laboratory investigation, and shop tests have been conducted to confirm the field procedure and determine the tension on the bolts during the installation. The main conclusion was that the bolts failed due to the concurrence of stress (over-torque that means stress level higher than yield one) and corrosion (pit/crevice conditions). This environmentally assisted failure is known as Hydrogen Embrittlement (HE). Test carried out using the same X-mas tree mounted on the platform justifies the assumption that in the field, where the conditions are far from the ideal, it is possible that even when a uniform torque is set, the tensile stress applied to the bolts is not uniform, making the situation critical. From the corrosion side, the failed bolts showed some corrosion points near the cracks, as due to environment in the crevice/pitting conditions required to justify the hydrogen presence (the bolts are not cathodically protected). Fatigue has been demonstrated not to be responsible for the failure. Solutions are recommended which can safely be adopted during the installation and the substitution of bolts on an existing wellhead, which is operative under pressure without shutting in the well, and not impairing the safety operating envelope.

  7. Improving service availability during link failure transients through alternate routing

    E-Print Network [OSTI]

    Vellanki, Siridhar

    2003-01-01T23:59:59.000Z

    A link failure in a network results in interruption of service for many end users. Currently, routers observing a link failure, recompute their routing tables to find new routes around the failure. However, the network drops packets in the transient...

  8. Sandia National Laboratories: Failure Mode and Effect Analysis...

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

    ProcessFailure Mode and Effect Analysis (FMEA) Tutorial Failure Mode and Effect Analysis (FMEA) Tutorial Failure Mode and Effect Analysis (FMEA) Tutorial (SAND2012-0602W) Tagged...

  9. Embrittlement and Flow Localization in Reactor Structural Materials

    SciTech Connect (OSTI)

    Xianglin Wu; Xiao Pan; James Stubbins

    2006-10-06T23:59:59.000Z

    Many reactor components and structural members are made from metal alloys due, in large part, to their strength and ability to resist brittle fracture by plastic deformation. However, brittle fracture can occur when structural material cannot undergo extensive, or even limited, plastic deformation due to irradiation exposure. Certain irradiation conditions lead to the development of a damage microstructure where plastic flow is limited to very small volumes or regions of material, as opposed to the general plastic flow in unexposed materials. This process is referred to as flow localization or plastic instability. The true stress at the onset of necking is a constant regardless of the irradiation level. It is called 'critical stress' and this critical stress has strong temperature dependence. Interrupted tensile testes of 316L SS have been performed to investigate the microstructure evolution and competing mechanism between mechanic twinning and planar slip which are believed to be the controlling mechanism for flow localization. Deformation twinning is the major contribution of strain hardening and good ductility for low temperatures, and the activation of twinning system is determined by the critical twinning stress. Phases transform and texture analyses are also discussed in this study. Finite element analysis is carried out to complement the microstructural analysis and for the prediction of materaials performance with and without stress concentration and irradiation.

  10. Impact of Motor Failures on Payback Periods

    E-Print Network [OSTI]

    Cheek, K. F.; Pillay, P.; Dudley, K. J.

    This paper uses MotorMaster and Vaughen's Complete Price Guide to determine payback periods for different motor failure scenarios. Some scenarios considered are rewinds, reconditions, and replacement of bearings. Prices for these repairs...

  11. Autonomous Thruster Failure Recovery for Underactuated Spacecraft

    E-Print Network [OSTI]

    . Miller September 2010 SSL #13­10 #12;2 #12;Autonomous Thruster Failure Recovery for Underactuated Spacecraft Christopher Masaru Pong, David W. Miller September 2010 SSL #12­11 This work is based

  12. NREL Test-to-Failure Protocol (Presentation)

    SciTech Connect (OSTI)

    Hacke, P.

    2012-03-01T23:59:59.000Z

    The presentation describes the test-to-failure protocol that was developed and piloted at NREL, stressing PV modules with multiple applications of damp heat (with bias) and thermal cycling until they fail.

  13. Individual Reactions to Failure in Virtual Teams

    E-Print Network [OSTI]

    Diaz, Ismael

    2012-02-14T23:59:59.000Z

    were more situational than attributions in the distributed condition, which were more dispositional. This finding supports the notion that collaboration configuration is important for understanding reactions to teammate failure....

  14. Universitat Augsburg Failure-Sensitive Specification

    E-Print Network [OSTI]

    Reif, Wolfgang

    techniques like fault tree analysis (FTA) [14], failure modes and effects analysis (FMEA), or preliminary as well. In this context we already formalized techniques like FTA [12][4] or FMEA. This paper presents

  15. Integrating Electricity Subsector Failure Scenarios into a Risk...

    Energy Savers [EERE]

    Integrating Electricity Subsector Failure Scenarios into a Risk Assessment Methodology (December 2013) Integrating Electricity Subsector Failure Scenarios into a Risk Assessment...

  16. DOE Collects Civil Penalties for Failure to Certify Consumer...

    Office of Environmental Management (EM)

    Collects Civil Penalties for Failure to Certify Consumer Refrigeration Products DOE Collects Civil Penalties for Failure to Certify Consumer Refrigeration Products April 22, 2015 -...

  17. Sandia National Laboratories: Sandian Presents on PV Failure...

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

    Modeling & SimulationSandian Presents on PV Failure Analysis at European PV Solar Energy Conference and Exhibition (EU PVSC) Sandian Presents on PV Failure Analysis...

  18. abc heart failure: Topics by E-print Network

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

    symptoms of acute heart failure and consecutive multiorgan failure for further treatment and to evaluate the indication for implantation of a ventricular assist device or...

  19. Processing of superconductive materials and high frequency

    SciTech Connect (OSTI)

    Smith, J.L.

    1987-01-01T23:59:59.000Z

    We do not know yet if superconductivity will become useful without refrigeration. Now, the superconductors are so different from copper that it is difficult to imagine replacing copper with such a brittle material. Superconductors conduct dc with no loss, ac with small losses, and microwaves in co-axial lines with almost no loss and with no dispersion from dc to the highest frequencies. They will probably allow us to close the gap between radio frequency and infrared optical transmission. Clearly your industry should know some things about where superconductivity may lead us and must consider whether the greater risk is to develop them or to let others try it. There are no easy answers yet.

  20. Failure mechanisms of polyimide and perfluoroalkoxy films under high frequency pulses

    E-Print Network [OSTI]

    Southampton, University of

    Failure mechanisms of polyimide and perfluoroalkoxy films under high frequency pulses Weijun Yin1 of polyimide and perfluoroalkoxy high temperature films under unipolar and bipolar repetitive pulses of art high temperature insulation materials, such as polyimide (PI), and perfluoroalkoxy (PFA) films

  1. Yield criteria for quasibrittle and frictional materials

    E-Print Network [OSTI]

    Davide Bigoni; Andrea Piccolroaz

    2010-10-09T23:59:59.000Z

    A new yield/damage function is proposed for modelling the inelastic behaviour of a broad class of pressure-sensitive, frictional, ductile and brittle-cohesive materials. The yield function allows the possibility of describing a transition between the shape of a yield surface typical of a class of materials to that typical of another class of materals. This is a fundamental key to model the behaviour of materials which become cohesive during hardening (so that the shape of the yield surface evolves from that typical of a granular material to that typical of a dense material), or which decrease cohesion due to damage accumulation. The proposed yield function is shown to agree with a variety of experimental data relative to soil, concrete, rock, metallic and composite powders, metallic foams, porous metals, and polymers. The yield function represents a single, convex and smooth surface in stress space approaching as limit situations well-known criteria and the extreme limits of convexity in the deviatoric plane. The yield function is therefore a generalization of several criteria, including von Mises, Drucker-Prager, Tresca, modified Tresca, Coulomb-Mohr, modified Cam-clay, and --concerning the deviatoric section-- Rankine and Ottosen. Convexity of the function is proved by developing two general propositions relating convexity of the yield surface to convexity of the corresponding function. These propositions are general and therefore may be employed to generate other convex yield functions.

  2. Stress and Failure Analysis of Rapidly Rotating Asteroid (29075) 1950 DA

    E-Print Network [OSTI]

    Hirabayashi, Masatoshi

    2014-01-01T23:59:59.000Z

    Rozitis et al. recently reported that near-Earth asteroid (29075) 1950 DA, whose bulk density ranges from 1.0 g/cm3 to 2.4 g/cm3, is a rubble pile and requires a cohesive strength of at least 44 Pa to 74 Pa to keep from failing due to its fast spin period. Since their technique for giving failure conditions required the averaged stress over the whole volume, it discarded information about the asteroid's failure mode and internal stress condition. This paper develops a finite element model and revisits the stress and failure analysis of 1950 DA. For the modeling, we do not consider material-hardening and softening. Under the assumption of an associated flow rule and uniform material distribution, we identify the deformation process of 1950 DA when its constant cohesion reaches the lowest value that keeps its current shape. The results show that to avoid structural failure the internal core requires a cohesive strength of at least 75 Pa - 85 Pa. It suggests that for the failure mode of this body, the internal c...

  3. Modeling of Brittle to Ductile Transition in BCC metals : : Strain Rate and Temperature dependence in [alpha]-Iron and Tantalum Monocrystals

    E-Print Network [OSTI]

    Karandikar, Keyur Kashinath

    2013-01-01T23:59:59.000Z

    knowledge of DBTT of critical materials used would havereach critical intensity value of the material. The materialThe critical distances for different FCC& BCC materials like

  4. A streamlined failure mode and effects analysis

    SciTech Connect (OSTI)

    Ford, Eric C., E-mail: eford@uw.edu; Smith, Koren; Terezakis, Stephanie; Croog, Victoria; Gollamudi, Smitha; Gage, Irene; Keck, Jordie; DeWeese, Theodore; Sibley, Greg [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD 21287 (United States)] [Department of Radiation Oncology and Molecular Radiation Sciences, Johns Hopkins University, Baltimore, MD 21287 (United States)

    2014-06-15T23:59:59.000Z

    Purpose: Explore the feasibility and impact of a streamlined failure mode and effects analysis (FMEA) using a structured process that is designed to minimize staff effort. Methods: FMEA for the external beam process was conducted at an affiliate radiation oncology center that treats approximately 60 patients per day. A structured FMEA process was developed which included clearly defined roles and goals for each phase. A core group of seven people was identified and a facilitator was chosen to lead the effort. Failure modes were identified and scored according to the FMEA formalism. A risk priority number,RPN, was calculated and used to rank failure modes. Failure modes with RPN > 150 received safety improvement interventions. Staff effort was carefully tracked throughout the project. Results: Fifty-two failure modes were identified, 22 collected during meetings, and 30 from take-home worksheets. The four top-ranked failure modes were: delay in film check, missing pacemaker protocol/consent, critical structures not contoured, and pregnant patient simulated without the team's knowledge of the pregnancy. These four failure modes hadRPN > 150 and received safety interventions. The FMEA was completed in one month in four 1-h meetings. A total of 55 staff hours were required and, additionally, 20 h by the facilitator. Conclusions: Streamlined FMEA provides a means of accomplishing a relatively large-scale analysis with modest effort. One potential value of FMEA is that it potentially provides a means of measuring the impact of quality improvement efforts through a reduction in risk scores. Future study of this possibility is needed.

  5. A physically-based abrasive wear model for composite materials

    SciTech Connect (OSTI)

    Lee, Gun Y.; Dharan, C.K.H.; Ritchie, Robert O.

    2001-05-01T23:59:59.000Z

    A simple physically-based model for the abrasive wear of composite materials is presented based on the mechanics and mechanisms associated with sliding wear in soft (ductile) matrix composites containing hard (brittle) reinforcement particles. The model is based on the assumption that any portion of the reinforcement that is removed as wear debris cannot contribute to the wear resistance of the matrix material. The size of this non-contributing portion of the reinforcement is estimated by modeling the three primary wear mechanisms, specifically plowing, interfacial cracking and particle removal. Critical variables describing the role of the reinforcement, such as its relative size and the nature of the matrix/reinforcement interface, are characterized by a single contribution coefficient, C. Predictions are compared with the results of experimental two-body (pin-on drum) abrasive wear tests performed on a model aluminum particulate-reinforced epoxy matrix composite material.

  6. Covetic Materials

    Energy Savers [EERE]

    Can re-melt, dilute, alloy... Fabrication of Covetic Materials - Nanocarbon Infusion 3 4 Technical Approach Unusual Characteristics of Covetic Materials ("covalent" &...

  7. Critical Material Parameters for Modeling Devices Made from an Epoxy-Based Shape Memory Polymer 

    E-Print Network [OSTI]

    Erel, Veysel

    2014-06-17T23:59:59.000Z

    the material. The strain to failure was small, and insufficient for extracting hyperelastic parameters. Using narrower gage width specimens, or perhaps a new specimen design, would benefit modeling and analysis for this material....

  8. Electrical overstress failure in silicon solar cells

    SciTech Connect (OSTI)

    Pease, R.L.; Barnum, J.R.; van Lint, V.A.J.; Vulliet, W.V.; Wrobel, T.F.

    1982-11-01T23:59:59.000Z

    A solar-cell electrical-overstress-failure model and the results of experimental measurements of threshold pulsed failure currents on four types of silicon solar cells are presented. The transient EMP field surrounding a lightning stroke has been identified as a potential threat to a photovoltaic array, yet failure analysis of solar cells in a pulsed environment had not previously been reported. Failure in the low-resistivity concentrator cells at pulse widths between 1 ..mu..s and 1 ms occurred initially in the junction. Finger damage in the form of silver melting occurs at currents only slightly greater than that required for junction damage. The result of reverse-bias transient-overstress tests on high-resistivity (10 ..cap omega..cm) cells demonstrated that the predominant failure mode was due to edge currents. These flat-plate cells failed at currents of only 4 to 20 A, which is one or two orders of magnitude below the model predictions. It thus appears that high-resistivity flat-plate cells are quite vulnerable to electrical overstress which could be produced by a variety of mechanisms.

  9. UTILITIES PROBLEMS AND FAILURES Electrical or plumbing failure/Flooding/Water leak/Natural gas

    E-Print Network [OSTI]

    Fernandez, Eduardo

    UTILITIES PROBLEMS AND FAILURES Electrical or plumbing failure/Flooding/Water leak/Natural gas for electrical shock. NOTIFY University Police. What should I do if I smell natural or propane gas? LEAVE/Repair line, 7-6333, or CALL the Campus University Police or Security at (561) 297-3500 or 911

  10. UTILITIES PROBLEMS AND FAILURES ELECTRICAL OR PLUMBING FAILURE/FLOODING/WATER LEAK

    E-Print Network [OSTI]

    Fernandez, Eduardo

    UTILITIES PROBLEMS AND FAILURES ELECTRICAL OR PLUMBING FAILURE/FLOODING/WATER LEAK NATURAL GAS - F 8a - 5p HBOI@FAU Security (772) 216-1124 Afterhours, Weekends or Holidays What should I do Police 911. · NOTIFY Building Safety personnel when possible. What should I do if I smell natural

  11. UTILITIES PROBLEMS AND FAILURES Electrical or plumbing failure/Flooding/Water leak/Natural gas or

    E-Print Network [OSTI]

    Fernandez, Eduardo

    UTILITIES PROBLEMS AND FAILURES Electrical or plumbing failure/Flooding/Water leak/Natural gas Physical Plant (772) 242-2246 M - F 8a - 5p (954) 762-5040 HBOI@FAU Security (772) 216-1124 Afterhours University Police. NOTIFY Building Safety personnel when possible. What should I do if I smell natural

  12. Materials Scientist

    Broader source: Energy.gov [DOE]

    Alternate Title(s):Materials Research Engineer; Metallurgical/Chemical Engineer; Product Development Manager;

  13. Creep failure of a reactor pressure vessel lower head under severe accident conditions

    SciTech Connect (OSTI)

    Pilch, M.M.; Ludwigsen, J.S.; Chu, T.Y. [Sandia National Labs., Albuquerque, NM (United States); Rashid, Y.R. [Anatech, San Diego, CA (United States)

    1998-08-01T23:59:59.000Z

    A severe accident in a nuclear power plant could result in the relocation of large quantities of molten core material onto the lower head of he reactor pressure vessel (RPV). In the absence of inherent cooling mechanisms, failure of the RPV ultimately becomes possible under the combined effects of system pressure and the thermal heat-up of the lower head. Sandia National Laboratories has performed seven experiments at 1:5th scale simulating creep failure of a RPV lower head. This paper describes a modeling program that complements the experimental program. Analyses have been performed using the general-purpose finite-element code ABAQUS-5.6. In order to make ABAQUS solve the specific problem at hand, a material constitutive model that utilizes temperature dependent properties has been developed and attached to ABAQUS-executable through its UMAT utility. Analyses of the LHF-1 experiment predict instability-type failure. Predicted strains are delayed relative to the observed strain histories. Parametric variations on either the yield stress, creep rate, or both (within the range of material property data) can bring predictions into agreement with experiment. The analysis indicates that it is necessary to conduct material property tests on the actual material used in the experimental program. The constitutive model employed in the present analyses is the subject of a separate publication.

  14. Celiac Node Failure Patterns After Definitive Chemoradiation for Esophageal Cancer in the Modern Era

    SciTech Connect (OSTI)

    Amini, Arya [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); UC Irvine School of Medicine, Irvine, California (United States); Xiao Lianchun [Department of Biostatistics, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Allen, Pamela K. [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Suzuki, Akihiro; Hayashi, Yuki [Department of Gastrointestinal Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Liao, Zhongxing [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Hofstetter, Wayne [Department of Thoracic and Cardiovascular Surgery, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Crane, Christopher; Komaki, Ritsuko [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Bhutani, Manoop S.; Lee, Jeffrey H.; Ajani, Jaffer A. [Department of Gastrointestinal Medical Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States); Welsh, James, E-mail: jwelsh@mdanderson.org [Department of Radiation Oncology, University of Texas MD Anderson Cancer Center, Houston, Texas (United States)

    2012-06-01T23:59:59.000Z

    Purpose: The celiac lymph node axis acts as a gateway for metastatic systemic spread. The need for prophylactic celiac nodal coverage in chemoradiation therapy for esophageal cancer is controversial. Given the improved ability to evaluate lymph node status before treatment via positron emission tomography (PET) and endoscopic ultrasound, we hypothesized that prophylactic celiac node irradiation may not be needed for patients with localized esophageal carcinoma. Methods and Materials: We reviewed the radiation treatment volumes for 131 patients who underwent definitive chemoradiation for esophageal cancer. Patients with celiac lymph node involvement at baseline were excluded. Median radiation dose was 50.4 Gy. The location of all celiac node failures was compared with the radiation treatment plan to determine whether the failures occurred within or outside the radiation treatment field. Results: At a median follow-up time of 52.6 months (95% CI 46.1-56.7 months), 6 of 60 patients (10%) without celiac node coverage had celiac nodal failure; in 5 of these patients, the failures represented the first site of recurrence. Of the 71 patients who had celiac coverage, only 5 patients (7%) had celiac region relapse. In multivariate analyses, having a pretreatment-to-post-treatment change in standardized uptake value on PET >52% (odds ratio [OR] 0.198, p = 0.0327) and having failure in the clinical target volume (OR 10.72, p = 0.001) were associated with risk of celiac region relapse. Of those without celiac coverage, the 6 patients that later developed celiac failure had a worse median overall survival time compared with the other 54 patients who did not fail (median overall survival time: 16.5 months vs. 31.5 months, p = 0.041). Acute and late toxicities were similar in both groups. Conclusions: Although celiac lymph node failures occur in approximately 1 of 10 patients, the lack of effective salvage treatments and subsequent low morbidity may justify prophylactic treatment in distal esophageal cancer patients.

  15. Power Grid Vulnerability to Geographically Correlated Failures

    E-Print Network [OSTI]

    Shepard, Kenneth

    Power Grid Vulnerability to Geographically Correlated Failures ­ Analysis and Control Implications such as telecommunications networks [14]. The power grid is vulnerable to natural disasters, such as earthquakes, hurricanes [17], [34]. Thus, we focus on the vulnerability of the power grid to an outage of several lines

  16. Battelle determines cause of Ashland tank failure

    SciTech Connect (OSTI)

    Mesloh, R.E.; Marschall, C.W.; Buchheit, R.D.; Kiefner, J.F. (Battelle Memorial Institute, Columbus, OH (US))

    1988-09-26T23:59:59.000Z

    An existing flaw, combined with embrittled steel and residual stresses, led to the catastrophic failure of the fuel oil tank at Ashland Petroleum Co., Floreffe, Pa., last January. Here is a look at the tank's background, events surrounding its rupture, and Battelle's methods for investigating the incident.

  17. Commutation failures in HVDC transmission systems

    SciTech Connect (OSTI)

    Thio, C.V.; Davies, J.B.; Kent, K.L. [Manitoba Hydro, Winnipeg, Manitoba (Canada)] [Manitoba Hydro, Winnipeg, Manitoba (Canada)

    1996-04-01T23:59:59.000Z

    This paper provides a formulation for the initiation or onset mechanism of commutation failures in line-commutated thyristor converters, assuming infinite (zero impedance) ac systems. A theoretical development and a parametric analysis is given. Theory validation by simulation and comparison to actual field experience data is also given.

  18. Evaluation of Corrosion Failure in Tractor-Trailer Brake System

    SciTech Connect (OSTI)

    Wilson, DF

    2002-10-22T23:59:59.000Z

    As reported to ORNL, concomitant with the introduction of different deicing and anti-icing compounds, there was an increase in the brake failure rate of tractor-trailer trucks. A forensic evaluation of a failed brake system was performed. Optical and scanning electron microscopic evaluation showed corrosion to be mostly confined to the brake table/lining interface. The corrosion is non-uniform as is to be expected for plain carbon steel in chloride environments. This initial analysis found no evidence for the chlorides of calcium and magnesium, which are the newly introduced deicing and antiicing compounds and are less soluble in water than the identified chlorides of sodium and potassium, in the scale. The result could be as a result of non-exposure of the examined brake table to calcium and magnesium chloride. The mechanisms for the increased failure rate are postulated as being an increased rate of corrosion due to positive shifts in the corrosion potential, and an increased amount of corrosion due to an increased ''time of wetness'' that results from the presence of hygroscopic salts. Laboratory scale evaluation of the corrosion of plain carbon steel in simulated deicing and anti-icing solutions need to be performed to determine corrosion rates and morphological development of corrosion product, to compare laboratory data to in-service data, and to rank economically feasible replacement materials for low carbon steel. In addition, the mechanical behavior of the lining attached to the brake shoe table needs to be assessed. It is opined that an appropriate adjustment of materials could easily allow for a doubling of a brake table/lining lifetime. Suggestions for additional work, to clarify the mechanisms of rust jacking and to develop possible solutions, are described.

  19. On the fracture toughness of advanced materials

    SciTech Connect (OSTI)

    Launey, Maximilien E.; Ritchie, Robert O.

    2008-11-24T23:59:59.000Z

    Few engineering materials are limited by their strength; rather they are limited by their resistance to fracture or fracture toughness. It is not by accident that most critical structures, such as bridges, ships, nuclear pressure vessels and so forth, are manufactured from materials that are comparatively low in strength but high in toughness. Indeed, in many classes of materials, strength and toughness are almost mutually exclusive. In the first instance, such resistance to fracture is a function of bonding and crystal structure (or lack thereof), but can be developed through the design of appropriate nano/microstructures. However, the creation of tough microstructures in structural materials, i.e., metals, polymers, ceramics and their composites, is invariably a compromise between resistance to intrinsic damage mechanisms ahead of the tip of a crack (intrinsic toughening) and the formation of crack-tip shielding mechanisms which principally act behind the tip to reduce the effective 'crack-driving force' (extrinsic toughening). Intrinsic toughening is essentially an inherent property of a specific microstructure; it is the dominant form of toughening in ductile (e.g., metallic) materials. However, for most brittle (e.g., ceramic) solids, and this includes many biological materials, it is largely ineffective and toughening conversely must be developed extrinsically, by such shielding mechanisms as crack bridging. From a fracture mechanics perspective, this results in toughening in the form of rising resistance-curve behavior where the fracture resistance actually increases with crack extension. The implication of this is that in many biological and high-strength advanced materials, toughness is developed primarily during crack growth and not for crack initiation. This is an important realization yet is still rarely reflected in the way that toughness is measured, which is invariably involves the use of single-value (crack-initiation) parameters such as the fracture toughness K{sub Ic}.

  20. Survey on Failure Modes and Failure Mechanisms in Digital Components and Systems

    SciTech Connect (OSTI)

    Cetiner, Mustafa Sacit [ORNL; Korsah, Kofi [ORNL; Muhlheim, Michael David [ORNL

    2009-01-01T23:59:59.000Z

    This paper presents the preliminary results of a survey on the operating experience of a broad range of digital components and systems deployed in various industries. The primary objective of this survey is to identify principal modes and mechanisms of failure in field-deployed digital systems. Earlier works have sought to determine the failure rates of various classes of digital devices with the intent to integrate this information into the risk analysis calculations though still immature for such systems. Failure rates of individual components or systems are not taken into account in this evaluation; only failure modes and their respective probabilistic distribution are considered. Preliminary results from two data sources, SPIDR and FARADIP, are presented.

  1. Continuous fiber ceramic composites-- A new generation of materials for industrial and corrosive applications

    SciTech Connect (OSTI)

    Craig, P.A.

    1999-07-01T23:59:59.000Z

    The market for advanced ceramics is very large and growing rapidly, at a rate of 20% per year. These materials are characterized by their excellent high temperature properties. They are finding use where temperatures exceed the capability of other materials, especially metals. Even so, they are not selected for many applications because of the brittleness of monolithic ceramics. In the search for improvement, material scientists reinforce ceramics with continuous ceramic fibers, such as silicon carbide. Embedded continuous ceramic fibers reinforce the ceramic matrix by deflecting and bridging fractures. These continuous fiber ceramic composite (CFCC) materials offer the advantages of ceramics--resistance to heat, erosion, and corrosion--while adding toughness and thermal shock resistance. CFCC materials are evolving to the advanced product development stage with Department of Energy support in the CFCC program. Designers are evaluating them in corrosive applications in major industries. Various CFCC's are described and several case studies of CVI SiC/SiC application testing are reviewed.

  2. Statistical Modeling of Corrosion Failures in Natural Gas Transmission Pipelines

    E-Print Network [OSTI]

    Cobanoglu, Mustafa Murat

    2014-03-28T23:59:59.000Z

    and deterioration processes in pipeline networks. Therefore, pipeline operators need to rethink their corrosion prevention strategies. These results of corrosion failures are forcing the companies to develop accurate maintenance models based on failure frequency...

  3. Gearbox Typical Failure Modes, Detection, and Mitigation Methods (Presentation)

    SciTech Connect (OSTI)

    Sheng, S.

    2014-01-01T23:59:59.000Z

    This presentation was given at the AWEA Operations & Maintenance and Safety Seminar and focused on what the typical gearbox failure modes are, how to detect them using detection techniques, and strategies that help mitigate these failures.

  4. Examination of the damage and failure response of tantalum and copper under varied shock loading conditions

    SciTech Connect (OSTI)

    Bronkhorst, Curt A [Los Alamos National Laboratory; Dennis - Koller, Darcie [Los Alamos National Laboratory; Cerreta, Ellen K [Los Alamos National Laboratory; Gray Ill, George T [Los Alamos National Laboratory; Bourne, Neil [AWE-ALDERMASTON

    2010-12-16T23:59:59.000Z

    A number of plate impact experiments have been conducted on high purity polycrystalline tantalum and copper samples using graded flyer plate configurations to alter the loading profile. These experiments are designed in a way so that a broad range of damage regimes are probed. The results show that the nucleation of damage primarily occurs at the grain boundaries of the materials. This affords us the opportunity to propose a porosity damage nucleation criterion which begins to account for the length scales of the microstructure (grain size distribution) and the mechanical response of the grain boundary regions (failure stress distribution). This is done in the context of a G-T-N type model for the ductile damage and failure response of both the materials examined. The role of micro-inertial effects on the porosity growth process is also considered.

  5. Modeling of microstructural effects on electromigration failure

    SciTech Connect (OSTI)

    Ceric, H. [Christian Doppler Laboratory for Reliability Issues in Microelectronics at the Institute for Microelectronics, TU Wien (Austria); Orio, R. L. de; Zisser, W.; Selberherr, S. [Institute for Microelectronics, TU Wien, Gußhausstraße 27-29, A-1040 Wien (Austria)

    2014-06-19T23:59:59.000Z

    Current electromigration models used for simulation and analysis of interconnect reliability lack the appropriate description of metal microstructure and consequently have a very limited predictive capability. Therefore, the main objective of our work was obtaining more sophisticated electromigration tools. The problem is addressed through a combination of different levels of atomistic modeling and already available, continuum level macroscopic models. A novel method for an ab initio calculation of the effective valence for electromigration is presented and its application on the analysis of EM behavior is demonstrated. Additionally, a simple analytical model for the early electromigration lifetime is obtained. We have shown that its application provides a reasonable estimate for the early electromigration failures including the effect of microstructure. A simulation study is also applied on electromigration failure in tin solder bumps, where it contributed the understanding of the role of tin crystal anisotropy in the degradation mechanism of solder bumps.

  6. Optimal adaptive control of cascading power grid failures

    E-Print Network [OSTI]

    Daniel Bienstock

    2010-12-17T23:59:59.000Z

    Dec 17, 2010 ... Abstract: We describe experiments with parallel algorithms for computing adaptive controls for attenuating power grid cascading failures.

  7. Export Failure and its Consequences: Theory and Evidence

    E-Print Network [OSTI]

    Mora, Jesse

    2015-01-01T23:59:59.000Z

    for export success . . . . . . . . . . . . . . . VA Model with Export Failure, Marketing Costs, and Financial2 Export Expansions of Products and Destinations I

  8. The Impact of Protection System Failures on Power System Reliability Evaluation 

    E-Print Network [OSTI]

    Jiang, Kai

    2012-11-05T23:59:59.000Z

    Figure 6-11. Reliability modeling of power systems with perfect protections. ............ 145 Figure 6-12. Reliability modeling of power systems with protection failures. ............. 146 Figure 6-13. 24-bus IEEE Reliability Test System (RTS... is reprinted from copyrighted material with permission from IEEE. ?2010 IEEE. Reprinted, with permission, from Kai Jiang and Chanan Singh, ?Reliability modeling of all-digital protection systems including impact of repair?? IEEE Trans. Power Delivery, vol...

  9. Role of seepage forces on hydraulic fracturing and failure patterns

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Role of seepage forces on hydraulic fracturing and failure patterns Alexander Rozhko Thesis September 2007 #12;ii Role of seepage forces on hydraulic fracturing and failure patterns Abstract. The mechanical role of seepage forces on hydraulic fracturing and failure patterns was studied both

  10. LESSONS LEARNED FROM A LANDFILL SLOPE FAILURE INVOLVING

    E-Print Network [OSTI]

    LESSONS LEARNED FROM A LANDFILL SLOPE FAILURE INVOLVING GEOSYTNTHETICS Virginia L. Wilson: Geosynthetics: Lessons Learned from Failures International Geosynthetics Society editors J.P. Giroud, K.L. Soderman and G.P. Raymond November 12, 1998 #12;LESSONS LEARNED FROM A LANDFILL SLOPE FAILURE INVOLVING

  11. Production-Run Software Failure Diagnosis via Hardware Performance Counters

    E-Print Network [OSTI]

    Sheridan, Jennifer

    Production-Run Software Failure Diagnosis via Hardware Performance Counters Joy Arulraj Po and huge financial loss during production runs. Tools that diagnose production-run failures with low is sometimes over 100%, for concurrency-bug failure diagnosis and hence are not suitable for production

  12. Novel failure prognostics approach with dynamic thresholds for machine degradation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Novel failure prognostics approach with dynamic thresholds for machine degradation Kamran Javed-processing and prognostics modeling. To estimate RUL of a degrading machinery, prognostics modeling phase requires precise knowledge about failure thresh- old (FT) (or failure definition). Practically, degrading machinery can have

  13. Modelling of dependence between critical failure and preventive maintenance

    E-Print Network [OSTI]

    Langseth, Helge

    Modelling of dependence between critical failure and preventive maintenance: The repair alert model, or a preventive maintenance (PM) action, where the latter will prevent the failure. It is reasonable to expect that the failure can be avoided by a possible preventive maintenance (PM) at some random time Z. If Z

  14. NO. ~EV. NO. Failure Modes and Effects Analysis -LRRR

    E-Print Network [OSTI]

    Rathbun, Julie A.

    of the Failure Modes and Effects Analysis (FMEA) is to discover critical failure areas in the LRRR experiment for the critical failure areas. A TM 868 contains the results of a final FMEA for the LRRR experiment. 2. 0 SUMMARY Since an LRRR was successfully deployed on the moon as a part of the Apollo 11 mission, this FMEA

  15. Failure Modes and Effects Analysis 300 Array -LRRR

    E-Print Network [OSTI]

    Rathbun, Julie A.

    of the Failure Modes and Effects Analysis (FMEA) is to discover critical failure areas in a system and to remove failure areas. 1. 2 This memo contains the results of the final FMEA for the 300 Array LRRR experiment was successfully deployed on the moon as a part of the Apollo 11 mission, this FMEA will not dwell in the aspects

  16. Scintillator material

    DOE Patents [OSTI]

    Anderson, David F. (Batavia, IL); Kross, Brian J. (Aurora, IL)

    1994-01-01T23:59:59.000Z

    An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography.

  17. Scintillator material

    DOE Patents [OSTI]

    Anderson, David F. (Batavia, IL); Kross, Brian J. (Aurora, IL)

    1992-01-01T23:59:59.000Z

    An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography.

  18. Scintillator material

    DOE Patents [OSTI]

    Anderson, D.F.; Kross, B.J.

    1992-07-28T23:59:59.000Z

    An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography. 4 figs.

  19. Scintillator material

    DOE Patents [OSTI]

    Anderson, D.F.; Kross, B.J.

    1994-06-07T23:59:59.000Z

    An improved scintillator material comprising cerium fluoride is disclosed. Cerium fluoride has been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to known scintillator materials such as thallium-doped sodium iodide, barium fluoride and bismuth germanate. As a result, cerium fluoride is favorably suited for use as a scintillator material in positron emission tomography. 4 figs.

  20. PDC IC WELD FAILURE EVALUATION AND RESOLUTION

    SciTech Connect (OSTI)

    Korinko, P.; Howard, S.; Maxwell, D.; Fiscus, J.

    2012-04-16T23:59:59.000Z

    During final preparations for start of the PDCF Inner Can (IC) qualification effort, welding was performed on an automated weld system known as the PICN. During the initial weld, using a pedigree canister and plug, a weld defect was observed. The defect resulted in a hole in the sidewall of the canister, and it was observed that the plug sidewall had not been consumed. This was a new type of failure not seen during development and production of legacy Bagless Transfer Cans (FB-Line/Hanford). Therefore, a team was assembled to determine the root cause and to determine if the process could be improved. After several brain storming sessions (MS and T, R and D Engineering, PDC Project), an evaluation matrix was established to direct this effort. The matrix identified numerous activities that could be taken and then prioritized those activities. This effort was limited by both time and resources (the number of canisters and plugs available for testing was limited). A discovery process was initiated to evaluate the Vendor's IC fabrication process relative to legacy processes. There were no significant findings, however, some information regarding forging/anneal processes could not be obtained. Evaluations were conducted to compare mechanical properties of the PDC canisters relative to the legacy canisters. Some differences were identified, but mechanical properties were determined to be consistent with legacy materials. A number of process changes were also evaluated. A heat treatment procedure was established that could reduce the magnetic characteristics to levels similar to the legacy materials. An in-situ arc annealing process was developed that resulted in improved weld characteristics for test articles. Also several tack welds configurations were addressed, it was found that increasing the number of tack welds (and changing the sequence) resulted in decreased can to plug gaps and a more stable weld for test articles. Incorporating all of the process improvements for the actual can welding process, however, did not result in an improved weld geometry. Several possibilities for the lack of positive response exist, some of which are that (1) an insufficient number of test articles were welded under prototypic conditions, (2) the process was not optimized so that significant improvements were observable over the 'noise', and (3) the in-situ arc anneal closed the gap down too much so the can was unable to exhaust pressure ahead of the weld. Several operational and mechanical improvements were identified. The weld clamps were changed to a design consistent with those used in the legacy operations. A helium puff operation was eliminated; it is believed that this operation was the cause of the original weld defect. Also, timing of plug mast movement was found to correspond with weld irregularities. The timing of the movement was changed to occur during weld head travel between tacks. In the end a three sequential tack weld process followed by a pulse weld at the same current and travel speed as was used for the legacy processes was suggested for use during the IC qualification effort. Relative to legacy welds, the PDC IC weld demonstrates greater fluctuation in the region of the weld located between tack welds. However, canister weld response (canister to canister) is consistent and with the aid of the optical mapping system (for targeting the cut position) is considered adequate. DR measurements and METs show the PDC IC welds to have sufficient ligament length to ensure adequate canister pressure/impact capacity and to ensure adequate stub function. The PDC welding process has not been optimized as a result of this effort. Differences remain between the legacy BTC welds and the PDC IC weld, but these differences are not sufficient to prevent resumption of the current PDC IC qualification effort. During the PDC IC qualification effort, a total of 17 cans will be welded and a variety of tests/inspections will be performed. The extensive data collected during that qualification effort should be of a sufficient population to determ

  1. Critical Materials:

    Broader source: Energy.gov (indexed) [DOE]

    lighting. 14 (bottom) Criticality ratings of shortlisted raw 76 materials. 15 77 2. Technology Assessment and Potential 78 This section reviews the major trends within...

  2. Failure Pressure Estimates of Steam Generator Tubes Containing Wear-type Defects

    SciTech Connect (OSTI)

    Yoon-Suk Chang; Jong-Min Kim; Nam-Su Huh; Young-Jin Kim [School of Mechanical Engineering, Sungkyunkwan University (Korea, Republic of); Seong Sik Hwang; Joung-Soo Kim [Korea Atomic Energy Research Institute (Korea, Republic of)

    2006-07-01T23:59:59.000Z

    It is commonly requested that steam generator tubes with defects exceeding 40% of wall thickness in depth should be plugged to sustain all postulated loads with appropriate margin. The critical defect dimensions have been determined based on the concept of plastic instability. This criterion, however, is known to be too conservative for some locations and types of defects. In this context, the accurate failure estimation for steam generator tubes with a defect draws increasing attention. Although several guidelines have been developed and are used for assessing the integrity of defected tubes, most of these guidelines are related to stress corrosion cracking or wall-thinning phenomena. As some of steam generator tubes are also failed due to fretting and so on, alternative failure estimation schemes for relevant defects are required. In this paper, three-dimensional finite element (FE) analyses are carried out under internal pressure condition to simulate the failure behavior of steam generator tubes with different defect configurations; elliptical wastage type, wear scar type and rectangular wastage type defects. Maximum pressures based on material strengths are obtained from more than a hundred FE results to predict the failure of the steam generator tube. After investigating the effect of key parameters such as wastage depth, wastage length and wrap angle, simplified failure estimation equations are proposed in relation to the equivalent stress at the deepest point in wastage region. Comparison of failure pressures predicted according to the proposed estimation scheme with some corresponding burst test data shows good agreement, which provides a confidence in the use of the proposed equations to assess the integrity of steam generator tubes with wear-type defects. (authors)

  3. The effect of squeeze clamping on the performance of polyethylene gas piping materials

    E-Print Network [OSTI]

    Jones, Robert Ernest

    1986-01-01T23:59:59.000Z

    of the crack tip and where loads are less than the yield strength as "brittle" fracture. This is the same type of behavior described by Chan and Williams as slow stable crack growth. 2. 2. ~22 * C~l An extensive literature search which included computer.... @here subsurface damage was found, the resulting crack dimensions were measured from photomicrographs taken in the SEM. ln addition, twelve unclamped c-shaped sections were prepared from the three materials and broken in liquid nitrogen as a control...

  4. Probabilistic Failure Analysis for Wound Composite Ceramic Cladding Assembly

    SciTech Connect (OSTI)

    Hemrick, James Gordon [ORNL] [ORNL; Lara-Curzio, Edgar [ORNL] [ORNL

    2013-01-01T23:59:59.000Z

    Advanced ceramic matrix composites based on silicon carbide (SiC) are being considered as candidate material systems for nuclear fuel cladding in light water reactors. The SiC composite structure is considered due to its assumed exceptional performance under accident scenarios, where its excellent high-temperature strength and slow reaction kinetics with steam and associated mitigated hydrogen production are desirable. The specific structures of interest consist of a monolithic SiC cylinder surrounded by interphase-coated SiC woven fibers in a tubular form and infiltrated with SiC. Additional SiC coatings on the outermost surface of the assembly are also being considered to prevent hydrothermal corrosion of the fibrous structure. The inner monolithic cylinder is expected to provide a hermetic seal to contain fission products under normal conditions. While this approach offers the promise of higher burn-up rates and safer behavior in the case of LOCA events, the reliability of such structures must be demonstrated in advance. Therefore, a probability failure analysis study was performed of such monolithic-composite hybrid structures to determine the feasibility of these design concepts. This analysis will be used to predict the future performance of candidate systems in an effort to determine the feasibility of these design concepts and to make future recommendations regarding materials selection.

  5. NSTX Failure Modes & Effects Analysis / NSTX-FMEA-71-10 / p. 1 of 115 FAILURE MODES AND EFFECTS ANALYSIS

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    NSTX Failure Modes & Effects Analysis / NSTX-FMEA-71-10 / p. 1 of 115 NSTX FAILURE MODES AND EFFECTS ANALYSIS (FMEA) Revision 10 Dated: November 2014 Prepared By: Name/WBS Signature Name: ________________________________________________ Ron Strykowsky, NSTX Upgrade Project Manager #12;NSTX Failure Modes & Effects Analysis / NSTX-FMEA-71

  6. Materials for solid state lighting

    SciTech Connect (OSTI)

    Johnson, S.G.; Simmons, J.A.

    2002-03-26T23:59:59.000Z

    Dramatic improvement in the efficiency of inorganic and organic light emitting diodes (LEDs and OLEDs) within the last decade has made these devices viable future energy efficient replacements for current light sources. However, both technologies must overcome major technical barriers, requiring significant advances in material science, before this goal can be achieved. Attention will be given to each technology associated with the following major areas of material research: (1) material synthesis, (2) process development, (3) device and defect physics, and (4) packaging. The discussion on material synthesis will emphasize the need for further development of component materials, including substrates and electrodes, necessary for improving device performance. The process technology associated with the LEDs and OLEDs is very different, but in both cases it is one factor limiting device performance. Improvements in process control and methodology are expected to lead to additional benefits of higher yield, greater reliability and lower costs. Since reliability and performance are critical to these devices, an understanding of the basic physics of the devices and device failure mechanisms is necessary to effectively improve the product. The discussion will highlight some of the more basic material science problems remaining to be solved. In addition, consideration will be given to packaging technology and the need for the development of novel materials and geometries to increase the efficiencies and reliability of the devices. The discussion will emphasize the performance criteria necessary to meet lighting applications, in order to illustrate the gap between current status and market expectations for future product.

  7. Cermet materials

    DOE Patents [OSTI]

    Kong, Peter C. (Idaho Falls, ID)

    2008-12-23T23:59:59.000Z

    A self-cleaning porous cermet material, filter and system utilizing the same may be used in filtering particulate and gaseous pollutants from internal combustion engines having intermetallic and ceramic phases. The porous cermet filter may be made from a transition metal aluminide phase and an alumina phase. Filler materials may be added to increase the porosity or tailor the catalytic properties of the cermet material. Additionally, the cermet material may be reinforced with fibers or screens. The porous filter may also be electrically conductive so that a current may be passed therethrough to heat the filter during use. Further, a heating element may be incorporated into the porous cermet filter during manufacture. This heating element can be coated with a ceramic material to electrically insulate the heating element. An external heating element may also be provided to heat the cermet filter during use.

  8. Composite material

    DOE Patents [OSTI]

    Hutchens, Stacy A. (Knoxville, TN); Woodward, Jonathan (Solihull, GB); Evans, Barbara R. (Oak Ridge, TN); O'Neill, Hugh M. (Knoxville, TN)

    2012-02-07T23:59:59.000Z

    A composite biocompatible hydrogel material includes a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa. A calcium comprising salt is disposed in at least some of the pores. The porous polymer matrix can comprise cellulose, including bacterial cellulose. The composite can be used as a bone graft material. A method of tissue repair within the body of animals includes the steps of providing a composite biocompatible hydrogel material including a porous polymer matrix, the polymer matrix including a plurality of pores and providing a Young's modulus of at least 10 GPa, and inserting the hydrogel material into cartilage or bone tissue of an animal, wherein the hydrogel material supports cell colonization in vitro for autologous cell seeding.

  9. Deformation-Twin-Induced Grain Boundary Failure

    SciTech Connect (OSTI)

    Yongfeng Zhang; Paul C. MIllett; Michael Tonks; Bulent Biner

    2012-01-01T23:59:59.000Z

    This work presents a mechanism of deformation-twin-induced grain boundary failure, and demonstrates the mechanism using molecular dynamics simulations. Deformation twinning is observed as the dominant mechanism during tensile deformation of columnar nanocrystalline body-centered cubic Mo. As a twin approaches a grain boundary, local stress concentration develops due to the incompatible plastic deformations in the two neighboring grains. The magnitude of the stress concentration increases as the twin widens, leading to grain boundary cracking by nucleation and coalescence of microcracks/voids.

  10. Reduce Steam Trap Failures at Chambers Works

    E-Print Network [OSTI]

    Kouba, C.

    Maintenance Mechanic), Rick Ragsdale (Fluor), Joyce Finkle (PC), Denis P Humphreys (Fluoroproducts), Jack Hemmert, Charlie Brown 10/20/2010 2 Steam trap failures are nothing new Steam trap programs are nothing new WHAT makes this program have such a huge... impact and How is it sustainable HOW we went about finding a solution What do you have learn from this 10/20/2010 3 Six Sigma Methodology was KEY to success Savings: $1MM annualized in only 6 months! 10/20/2010 4Define: Project CTQ?s Customer...

  11. Argonne National Laboratory Investigates Premature Bearing Failures...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of this investigation were recently published in the peer-reviewed journal Wear, titled "Material Wear and Fatigue in Wind Turbine Systems" and presented at the corresponding Wear...

  12. Analysis of HP2 nozzle assembly failure of a gas turbine

    SciTech Connect (OSTI)

    Anto, P.F.; Singh, S.K. [Oil and Natural Gas Corp. Ltd., Maharashtra (India). Inst. of Engineering and Ocean Technology

    1998-12-31T23:59:59.000Z

    The HP2 nozzle assembly of one of the process platform failed by plastic deformation of the vanes after an operating life of 20,000 hours. The vanes were made of alloy 31. The failed vanes were subjected to detailed failure analysis by conducting metallography, hardness testing, energy dispersive spectroscopy, x-ray diffraction and electron probe micro analysis. The phenomenon of sulfidation and catastrophic oxidation was not observed in the material. It was found that the material had undergone high temperature oxidation. The material did not show any signs of creep damage and phase growth preferential attack of carbides was identified. The alloy exhibited loss of hardness at the aerofoil surface which aided material erosion and degradation of alloy strength properties. Various thermal barrier coatings to prevent high temperature oxidation were studied.

  13. Disruption of POF1B binding to nonmuscle actin filaments is associated with premature ovarian failure.

    E-Print Network [OSTI]

    2006-01-01T23:59:59.000Z

    premature ovar- ian failure: analysis of 71 cases. Humanalysis of two candidate genes for premature ovarian failure,

  14. Material Symbols 

    E-Print Network [OSTI]

    Clark, Andy

    2006-01-01T23:59:59.000Z

    What is the relation between the material, conventional symbol structures that we encounter in the spoken and written word, and human thought? A common assumption, that structures a wide variety of otherwise competing ...

  15. Complex Materials

    ScienceCinema (OSTI)

    Cooper, Valentino

    2014-05-23T23:59:59.000Z

    Valentino Cooper uses some of the world's most powerful computing to understand how materials work at subatomic levels, studying breakthroughs such as piezoelectrics, which convert mechanical stress to electrical energy.

  16. Defense against common mode failures in protection system design

    SciTech Connect (OSTI)

    Wyman, R.H.; Johnson, G.L.

    1997-08-27T23:59:59.000Z

    The introduction of digital instrumentation and control into reactor safety systems creates a heightened concern about common-mode failure. This paper discusses the concern and methods to cope with the concern. Common-mode failures have been a ``fact-of-life`` in existing systems. The informal introduction of defense-in-depth and diversity (D-in-D&D)-coupled with the fact that hardware common-mode failures are often distributed in time-has allowed systems to deal with past common-mode failures. However, identical software operating in identical redundant systems presents the potential for simultaneous failure. Consequently, the use of digital systems raises the concern about common-mode failure to a new level. A more methodical approach to mitigating common-mode failure is needed to address these concerns. Purposeful introduction of D-in-D&D has been used as a defense against common-mode failure in reactor protection systems. At least two diverse systems are provided to mitigate any potential initiating event. Additionally, diverse displays and controls are provided to allow the operator to monitor plant status and manually initiate engineered safety features. A special form of conimon-mode failure analysis called ``defense-in-depth and diversity analysis`` has been developed to identify possible conimon-mode failure vulnerabilities in digital systems. An overview of this analysis technique is provided.

  17. Power Grid Defense Against Malicious Cascading Failure

    E-Print Network [OSTI]

    Shakarian, Paulo; Lindelauf, Roy

    2014-01-01T23:59:59.000Z

    An adversary looking to disrupt a power grid may look to target certain substations and sources of power generation to initiate a cascading failure that maximizes the number of customers without electricity. This is particularly an important concern when the enemy has the capability to launch cyber-attacks as practical concerns (i.e. avoiding disruption of service, presence of legacy systems, etc.) may hinder security. Hence, a defender can harden the security posture at certain power stations but may lack the time and resources to do this for the entire power grid. We model a power grid as a graph and introduce the cascading failure game in which both the defender and attacker choose a subset of power stations such as to minimize (maximize) the number of consumers having access to producers of power. We formalize problems for identifying both mixed and deterministic strategies for both players, prove complexity results under a variety of different scenarios, identify tractable cases, and develop algorithms f...

  18. Nuclear fuel elements made from nanophase materials

    DOE Patents [OSTI]

    Heubeck, Norman B. (Schenectady, NY)

    1998-01-01T23:59:59.000Z

    A nuclear reactor core fuel element is composed of nanophase high temperature materials. An array of the fuel elements in rod form are joined in an open geometry fuel cell that preferably also uses such nanophase materials for the cell structures. The particular high temperature nanophase fuel element material must have the appropriate mechanical characteristics to avoid strain related failure even at high temperatures, in the order of about 3000.degree. F. Preferably, the reactor type is a pressurized or boiling water reactor and the nanophase material is a high temperature ceramic or ceramic composite. Nanophase metals, or nanophase metals with nanophase ceramics in a composite mixture, also have desirable characteristics, although their temperature capability is not as great as with all-ceramic nanophase material. Combinations of conventional or nanophase metals and conventional or nanophase ceramics can be employed as long as there is at least one nanophase material in the composite. The nuclear reactor so constructed has a number of high strength fuel particles, a nanophase structural material for supporting a fuel rod at high temperature, a configuration to allow passive cooling in the event of a primary cooling system failure, an ability to retain a coolable geometry even at high temperatures, an ability to resist generation of hydrogen gas, and a configuration having good nuclear, corrosion, and mechanical characteristics.

  19. Nuclear fuel elements made from nanophase materials

    DOE Patents [OSTI]

    Heubeck, N.B.

    1998-09-08T23:59:59.000Z

    A nuclear reactor core fuel element is composed of nanophase high temperature materials. An array of the fuel elements in rod form are joined in an open geometry fuel cell that preferably also uses such nanophase materials for the cell structures. The particular high temperature nanophase fuel element material must have the appropriate mechanical characteristics to avoid strain related failure even at high temperatures, in the order of about 3000 F. Preferably, the reactor type is a pressurized or boiling water reactor and the nanophase material is a high temperature ceramic or ceramic composite. Nanophase metals, or nanophase metals with nanophase ceramics in a composite mixture, also have desirable characteristics, although their temperature capability is not as great as with all-ceramic nanophase material. Combinations of conventional or nanophase metals and conventional or nanophase ceramics can be employed as long as there is at least one nanophase material in the composite. The nuclear reactor so constructed has a number of high strength fuel particles, a nanophase structural material for supporting a fuel rod at high temperature, a configuration to allow passive cooling in the event of a primary cooling system failure, an ability to retain a coolable geometry even at high temperatures, an ability to resist generation of hydrogen gas, and a configuration having good nuclear, corrosion, and mechanical characteristics. 5 figs.

  20. Common-Cause Failure Analysis in Event Assessment

    SciTech Connect (OSTI)

    Dana L. Kelly; Dale M. Rasmuson

    2008-09-01T23:59:59.000Z

    This paper describes the approach taken by the U. S. Nuclear Regulatory Commission to the treatment of common-cause failure in probabilistic risk assessment of operational events. The approach is based upon the Basic Parameter Model for common-cause failure, and examples are illustrated using the alpha-factor parameterization, the approach adopted by the NRC in their Standardized Plant Analysis Risk (SPAR) models. The cases of a failed component (with and without shared common-cause failure potential) and a component being unavailable due to preventive maintenance or testing are addressed. The treatment of two related failure modes (e.g., failure to start and failure to run) is a new feature of this paper. These methods are being applied by the NRC in assessing the risk significance of operational events for the Significance Determination Process (SDP) and the Accident Sequence Precursor (ASP) program.

  1. Failure Predictions for VHTR Core Components using a Probabilistic Contiuum Damage Mechanics Model

    SciTech Connect (OSTI)

    Fok, Alex

    2013-10-30T23:59:59.000Z

    The proposed work addresses the key research need for the development of constitutive models and overall failure models for graphite and high temperature structural materials, with the long-term goal being to maximize the design life of the Next Generation Nuclear Plant (NGNP). To this end, the capability of a Continuum Damage Mechanics (CDM) model, which has been used successfully for modeling fracture of virgin graphite, will be extended as a predictive and design tool for the core components of the very high- temperature reactor (VHTR). Specifically, irradiation and environmental effects pertinent to the VHTR will be incorporated into the model to allow fracture of graphite and ceramic components under in-reactor conditions to be modeled explicitly using the finite element method. The model uses a combined stress-based and fracture mechanics-based failure criterion, so it can simulate both the initiation and propagation of cracks. Modern imaging techniques, such as x-ray computed tomography and digital image correlation, will be used during material testing to help define the baseline material damage parameters. Monte Carlo analysis will be performed to address inherent variations in material properties, the aim being to reduce the arbitrariness and uncertainties associated with the current statistical approach. The results can potentially contribute to the current development of American Society of Mechanical Engineers (ASME) codes for the design and construction of VHTR core components.

  2. Impact of Fuel Failure on Criticality Safety of Used Nuclear Fuel

    SciTech Connect (OSTI)

    Marshall, William BJ J [ORNL] [ORNL; Wagner, John C [ORNL] [ORNL

    2012-01-01T23:59:59.000Z

    Commercial used nuclear fuel (UNF) in the United States is expected to remain in storage for considerably longer periods than originally intended (e.g., <40 years). Extended storage (ES) time and irradiation of nuclear fuel to high-burnup values (>45 GWd/t) may increase the potential for fuel failure during normal and accident conditions involving storage and transportation. Fuel failure, depending on the severity, can result in changes to the geometric configuration of the fuel, which has safety and regulatory implications. The likelihood and extent of fuel reconfiguration and its impact on the safety of the UNF is not well understood. The objective of this work is to assess and quantify the impact of fuel reconfiguration due to fuel failure on criticality safety of UNF in storage and transportation casks. This effort is primarily motivated by concerns related to the potential for fuel degradation during ES periods and transportation following ES. The criticality analyses consider representative UNF designs and cask systems and a range of fuel enrichments, burnups, and cooling times. The various failed-fuel configurations considered are designed to bound the anticipated effects of individual rod and general cladding failure, fuel rod deformation, loss of neutron absorber materials, degradation of canister internals, and gross assembly failure. The results quantify the potential impact on criticality safety associated with fuel reconfiguration and may be used to guide future research, design, and regulatory activities. Although it can be concluded that the criticality safety impacts of fuel reconfiguration during transportation subsequent to ES are manageable, the results indicate that certain configurations can result in a large increase in the effective neutron multiplication factor, k{sub eff}. Future work to inform decision making relative to which configurations are credible, and therefore need to be considered in a safety evaluation, is recommended.

  3. Hardfacing material

    DOE Patents [OSTI]

    Branagan, Daniel J. (Iona, ID)

    2012-01-17T23:59:59.000Z

    A method of producing a hard metallic material by forming a mixture containing at least 55% iron and at least one of boron, carbon, silicon and phosphorus. The mixture is formed into an alloy and cooled to form a metallic material having a hardness of greater than about 9.2 GPa. The invention includes a method of forming a wire by combining a metal strip and a powder. The metal strip and the powder are rolled to form a wire containing at least 55% iron and from two to seven additional elements including at least one of C, Si and B. The invention also includes a method of forming a hardened surface on a substrate by processing a solid mass to form a powder, applying the powder to a surface to form a layer containing metallic glass, and converting the glass to a crystalline material having a nanocrystalline grain size.

  4. Simulations of Failure via Three-Dimensional Cracking in Fuel Cladding for Advanced Nuclear Fuels

    SciTech Connect (OSTI)

    Lu, Hongbing; Bukkapatnam, Satish; Harimkar, Sandip; Singh, Raman; Bardenhagen, Scott

    2014-01-09T23:59:59.000Z

    Enhancing performance of fuel cladding and duct alloys is a key means of increasing fuel burnup. This project will address the failure of fuel cladding via three-dimensional cracking models. Researchers will develop a simulation code for the failure of the fuel cladding and validate the code through experiments. The objective is to develop an algorithm to determine the failure of fuel cladding in the form of three-dimensional cracking due to prolonged exposure under varying conditions of pressure, temperature, chemical environment, and irradiation. This project encompasses the following tasks: 1. Simulate 3D crack initiation and growth under instantaneous and/or fatigue loads using a new variant of the material point method (MPM); 2. Simulate debonding of the materials in the crack path using cohesive elements, considering normal and shear traction separation laws; 3. Determine the crack propagation path, considering damage of the materials incorporated in the cohesive elements to allow the energy release rate to be minimized; 4. Simulate the three-dimensional fatigue crack growth as a function of loading histories; 5. Verify the simulation code by comparing results to theoretical and numerical studies available in the literature; 6. Conduct experiments to observe the crack path and surface profile in unused fuel cladding and validate against simulation results; and 7. Expand the adaptive mesh refinement infrastructure parallel processing environment to allow adaptive mesh refinement at the 3D crack fronts and adaptive mesh merging in the wake of cracks. Fuel cladding is made of materials such as stainless steels and ferritic steels with added alloying elements, which increase stability and durability under irradiation. As fuel cladding is subjected to water, chemicals, fission gas, pressure, high temperatures, and irradiation while in service, understanding performance is essential. In the fast fuel used in advanced burner reactors, simulations of the nuclear fuels are critical to understand the burnup, and thus the fuel efficiency.

  5. Journal of Nuclear Materials 187(1992) 1-31 North-Holland

    E-Print Network [OSTI]

    Raffray, A. René

    1992-01-01T23:59:59.000Z

    tritium inventories 1. Introduction Interest in the use of solid lithium-based materials as tritium/multiplier thermomechanical behavior Corrosion and mass transfer Structural response and failure modes in fusion environment

  6. "Tablet-level Origin of Toughening in Abalone Shells and Translation to Synthetic Nanocomposite Materials"

    E-Print Network [OSTI]

    Ghosh, Somnath

    bio-inspired nanocomposites. In particular, the development of a nacre-like material, fabricated by 3D printing and exhibiting similar failure modes, will be presented. Then, I will discuss the nanomechanics

  7. Size-dependent mechanical properties of beta-structures in protein materials

    E-Print Network [OSTI]

    Keten, Sinan

    2010-01-01T23:59:59.000Z

    Protein materials such as spider silk can be exceptionally strong, and they can stretch tremendously before failure. Notably, silks are made entirely of proteins, which owe their structure and stability to weak molecular ...

  8. A Methodology Supporting the Risk-Informed Management of Materials Degradation

    SciTech Connect (OSTI)

    Unwin, Stephen D.; Lowry, Peter P.; Toyooka, Michael Y.

    2011-07-28T23:59:59.000Z

    This paper describes a methodology for the synthesis of materials degradation data with nuclear power plant service data to estimate the long-term failure rates of passive components.

  9. Log-periodic behavior of a hierarchical failure model with ...

    E-Print Network [OSTI]

    earthquakes are accepted to be a type example of self— organization. ' We ?rst ..... the expected frictional heating on faults is not observed. [35]. The failure ...

  10. Wind Turbine Gearbox Failure Modes - A Brief (Presentation)

    SciTech Connect (OSTI)

    Sheng, S.; McDade, M.; Errichello, R.

    2011-10-01T23:59:59.000Z

    Wind turbine gearboxes are not always meeting 20-year design life. Premature failure of gearboxes increases cost of energy, turbine downtime, unplanned maintenance, gearbox replacement and rebuild, and increased warranty reserves. The problem is widespread, affects most Original Equipment Manufacturers, and is not caused by manufacturing practices. There is a need to improve gearbox reliability and reduce turbine downtime. The topics of this presentation are: GRC (Gearbox Reliability Collaborative) technical approach; Gearbox failure database; Recorded incidents summary; Top failure modes for bearings; Top failure modes for gears; GRC test gearbox; Bearing nomenclature; Test history; Real damage; Gear sets; Bearings; Observations; and Summary. 5 refs.

  11. Poroelastic damage rheology: Dilation, compaction, and failure of rocks

    E-Print Network [OSTI]

    Lyakhovsky, Vladimir

    Poroelastic damage rheology: Dilation, compaction, and failure of rocks Yariv Hamiel Institute December 2004; Published 26 January 2005. Hamiel, Y., V. Lyakhovsky, and A. Agnon (2005), Poroelastic

  12. adhesive failure pattern: Topics by E-print Network

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

    adhesives is a subject of great importance Mahadevan, L. 2 Dynamical failure of Turing patterns Condensed Matter (arXiv) Summary: The emergence of stable disordered patterns...

  13. GROUND PLANE INSULATION FAILURE IN THE FIRST TPC SUPERCONDUCTING COIL

    E-Print Network [OSTI]

    Green, M.A.

    2010-01-01T23:59:59.000Z

    FAILURE IN THE FIRST TPC SUPERCONDUCTING COIL M. A. Green,Time Projection Cnamber) thin superconducting solenoid. Theand breakage of the superconductor. The UPA circuit melted

  14. Fundamental Approach to Electrode Fabrication and Failure Analysis

    Broader source: Energy.gov (indexed) [DOE]

    Fundamental Approach to Electrode Fabrication and Failure Analysis Vince Battaglia LBNL May 11, 2011 This presentation does not contain any proprietary, confidential, or otherwise...

  15. applying failure mode: Topics by E-print Network

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

    diagrams (PFDs), hierarchical task analysis (HTA), failure mode and effects analysis (FMEA), systematic human error reduction (more) Griffin, Melissa Corinne 2010-01-01 3...

  16. Investigations of Bearing Failures Associated with White Etching...

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

    of Bearing Failures Associated with White Etching Areas (irWEAs) in Wind Turbine Gearboxes Presented by Bob Errichello of GEARTECH at the Wind Turbine Tribology...

  17. antihypertensive trial failures: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  18. acute hepatic failure: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  19. arrester failure rate: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  20. antiretroviral therapy failure: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  1. acute liver failure: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  2. antigen psa failure: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  3. arteriovenous fistula failure: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  4. acute renal failure: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  5. antiretroviral drug failure: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  6. adult respiratory failure: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  7. Tribological Analysis of White Etching Crack (WEC) Failures in...

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

    Crack (WEC) Failures in Rolling Element Bearings Presented by Arnaud Ruellan, INSA de Lyon at the Wind Turbine Tribology Seminar 2014. 20141030NREL2014ArgonneRuellancomV...

  8. GROUND PLANE INSULATION FAILURE IN THE FIRST TPC SUPERCONDUCTING COIL

    E-Print Network [OSTI]

    Green, M.A.

    2010-01-01T23:59:59.000Z

    FAILURE IN THE FIRST TPC SUPERCONDUCTING COIL M. A. Green,Time Projection Cnamber) thin superconducting solenoid. Thefailure of the first superconducting coil at the Lawrence

  9. Materials Science

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

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighand Retrievals from a New 183-GHzMARSecurityMaterials Science Materials

  10. Link failure detection in a parallel computer

    DOE Patents [OSTI]

    Archer, Charles J. (Rochester, MN); Blocksome, Michael A. (Rochester, MN); Megerian, Mark G. (Rochester, MN); Smith, Brian E. (Rochester, MN)

    2010-11-09T23:59:59.000Z

    Methods, apparatus, and products are disclosed for link failure detection in a parallel computer including compute nodes connected in a rectangular mesh network, each pair of adjacent compute nodes in the rectangular mesh network connected together using a pair of links, that includes: assigning each compute node to either a first group or a second group such that adjacent compute nodes in the rectangular mesh network are assigned to different groups; sending, by each of the compute nodes assigned to the first group, a first test message to each adjacent compute node assigned to the second group; determining, by each of the compute nodes assigned to the second group, whether the first test message was received from each adjacent compute node assigned to the first group; and notifying a user, by each of the compute nodes assigned to the second group, whether the first test message was received.

  11. CONTAINER MATERIALS, FABRICATION AND ROBUSTNESS

    SciTech Connect (OSTI)

    Dunn, K.; Louthan, M.; Rawls, G.; Sindelar, R.; Zapp, P.; Mcclard, J.

    2009-11-10T23:59:59.000Z

    The multi-barrier 3013 container used to package plutonium-bearing materials is robust and thereby highly resistant to identified degradation modes that might cause failure. The only viable degradation mechanisms identified by a panel of technical experts were pressurization within and corrosion of the containers. Evaluations of the container materials and the fabrication processes and resulting residual stresses suggest that the multi-layered containers will mitigate the potential for degradation of the outer container and prevent the release of the container contents to the environment. Additionally, the ongoing surveillance programs and laboratory studies should detect any incipient degradation of containers in the 3013 storage inventory before an outer container is compromised.

  12. Preventing aneuploidy and the consequences of failure

    E-Print Network [OSTI]

    Prabhu, Vineet R. (Vineet Ranjan)

    2009-01-01T23:59:59.000Z

    The maintenance and transmission of genetic material is critical for the survival of cells and organisms. Sexually reproducing diploid organisms undergo meiosis to produce haploid gametes, so that the resulting progeny are ...

  13. Materials compatibility.

    SciTech Connect (OSTI)

    Somerday, Brian P.

    2010-04-01T23:59:59.000Z

    Objectives are to enable development and implementation of codes and standards for H{sub 2} containment components: (1) Evaluate data on mechanical properties of materials in H{sub 2} gas - Technical Reference on Hydrogen Compatibility of Materials; (2) Generate new benchmark data on high-priority materials - Pressure vessel steels, stainless steels; and (3) Establish procedures for reliable materials testing - Sustained-load cracking, fatigue crack propagation. Summary of this presentation are: (1) Completed measurement of cracking thresholds (K{sub TH}) for Ni-Cr-Mo pressure vessel steels in high-pressure H{sub 2} gas - K{sub TH} measurements required in ASME Article KD-10 (2) Crack arrest test methods appear to yield non-conservative results compared to crack initiation test methods - (a) Proposal to insert crack initiation test methods in Article KD-10 will be presented to ASME Project Team on Hydrogen Tanks, and (b) Crack initiation methods require test apparatus designed for dynamic loading of specimens in H{sub 2} gas; and (3) Demonstrated ability to measure fatigue crack growth of pressure vessel steels in high-pressure H{sub 2} gas - (a) Fatigue crack growth data in H{sub 2} required in ASME Article KD-10, and (b) Test apparatus is one of few in U.S. or abroad for measuring fatigue crack growth in >100 MPa H{sub 2} gas.

  14. Interfacial phenomena on selected cathode materials

    SciTech Connect (OSTI)

    Kostecki, Robert; Matsuo, Yoshiaki; McLarnon, Frank

    2001-06-22T23:59:59.000Z

    We have carried out a series of surface studies of selected cathode materials. Instrumental techniques such as Raman microscopy, surface enhanced Raman spectroscopy (SERS), and atomic force microscopy were used to investigate the cathode surfaces. The goal of this study was to identify detrimental processes which occur at the electrode/electrolyte interface and can lead to electrode degradation and failure during cycling and/or storage at elevated temperatures.

  15. Effect of the porosity on the fracture surface roughness of sintered materials: From anisotropic to isotropic self-affine scaling

    E-Print Network [OSTI]

    Tristan Cambonie; Jonathan Bares; Lamine Hattali; Daniel Bonamy; Véronique Lazarus; Harold Auradou

    2015-01-16T23:59:59.000Z

    To unravel how the microstructure affects the fracture surface roughness in heterogeneous brittle solids like rocks or ceramics, we characterized the roughness statistics of post-mortem fracture surfaces in home-made materials of adjustable microstructure length-scale and porosity, obtained by sintering monodisperse polystyrene beads. Beyond the characteristic size of disorder, the roughness profiles are found to exhibit self-affine scaling features evolving with porosity. Starting from a null value and increasing the porosity, we quantitatively modify the self-affine scaling properties from anisotropic (at low porosity) to isotropic (for porosity larger than 10 %).

  16. Single shell tank sluicing history and failure frequency

    SciTech Connect (OSTI)

    HERTZEL, J.S.

    1998-11-10T23:59:59.000Z

    This document assesses the potential for failure of the single-shell tanks (SSTs) that are presumably sound and helps to establish the retrieval priorities for these and the assumed leakers. Furthermore, this report examines probabilities of SST failure as a function of age and operational history, and provides a simple statistical summary of historical leak volumes, leak rates, and corrosion factor.

  17. Lessons Learned from Failures Involving Geofoam in Roads and Embankments

    E-Print Network [OSTI]

    Horvath, John S.

    Lessons Learned from Failures Involving Geofoam in Roads and Embankments Manhattan College Research July 1999) #12;Lessons Learned from Failures Involving Geofoam in Roads and Embankments Manhattan College Research Report No. CE/GE-99-1 ii This page intentionally left blank. #12;Lessons Learned from

  18. Benefits of Multiple TX Powers Robustness to Beacon Node Failure

    E-Print Network [OSTI]

    Chen, Yiling

    the partial failure of the infrastructure. Our system, called MoteTrack, is based on low-power radios coupledAccuracy Benefits of Multiple TX Powers Robustness to Beacon Node Failure Introduction to a wide range of applications. For some, the location tracking system must continue to operate despite

  19. THERMO-MECHANICAL SIMULATIONS OF DUCTILE FAILURE BY MESHFREE METHOD

    E-Print Network [OSTI]

    Ponce, V. Miguel

    THERMO-MECHANICAL SIMULATIONS OF DUCTILE FAILURE BY MESHFREE METHOD Dr. Akhilesh Jha Lead Engineer (ASB), spall fracture, and crack. Since this type of thermo-mechanical phenomena involves large spall strength in simulating ductile failure have been reviewed. A thermo- mechanical coupling algorithm

  20. A UNIFIED FAILURE/DAMAGE APPROACH TO BATTLE DAMAGE REGENERATION

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A UNIFIED FAILURE/DAMAGE APPROACH TO BATTLE DAMAGE REGENERATION : APPLICATION TO GROUND MILITARY-availability. Military weapon systems availability can be affected by system failures or by damage to the system damage into account in their more general dependability studies. This paper takes a look at the issues

  1. Glacier: Highly durable, decentralized storage despite massive correlated failures

    E-Print Network [OSTI]

    Pennsylvania, University of

    Glacier: Highly durable, decentralized storage despite massive correlated failures Andreas be considered when attempting to provide highly durable storage. In this paper, we describe Glacier failures. Glacier is designed to aggressively minimize the cost of this redun- dancy in space and time

  2. Modelling of dependence between critical failure and preventive maintenance

    E-Print Network [OSTI]

    Langseth, Helge

    Modelling of dependence between critical failure and preventive maintenance: The repair alert model, or a preventive maintenance (PM) action, where the latter will prevent the failure. It is reasonable to expect be avoided by a possible preventive maintenance (PM) at some random time Z. If Z

  3. Degradation and Failure Characteristics of NPP Containment Protective Coating Systems

    SciTech Connect (OSTI)

    Sindelar, R.L.

    2000-12-01T23:59:59.000Z

    A research program to investigate the performance and potential for failure of Service Level I coating systems used in nuclear power plant containment is in progress. The research activities are aligned to address phenomena important to cause failure as identified by the industry coatings expert panel.

  4. Mission Failure Probability Calculations for Critical Function Mechanizations

    E-Print Network [OSTI]

    Koopman, Philip

    conditions. Related to the reliability of a component is the rate at which such devices fail. The failure shown that the failure rate of electronic components follow the characteristics of a bathtub curve Institute Technical Report CMU-RI-TR-97-44 December 16, 1997 #12;1 Abstract Reliability analysis

  5. Component criticality in failure cascade processes of network systems

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    considered. KEYWORDS: Complex Infrastructures Vulnerability, Cascade Failures, Criticality Indicators of the cascade. For example, in electrical power transmission networks a cascade of events leading to blackout failures are a major threat to distributed, interconnected systems such as power transmission networks(1

  6. Modeling Stochastic Correlated Failures and their Effects on Network Reliability

    E-Print Network [OSTI]

    Hayat, Majeed M.

    --The physical infrastructure of communication net- works is vulnerable to spatially correlated failures arising geographically. In general, physical infrastructure of communication networks is vulnerable to failures-Naeini, Jorge E. Pezoa, Ghady Azar, Nasir Ghani, and Majeed M. Hayat Department of Electrical and Computer

  7. FAILURE MODES AND EFFECTS ANALYSIS Dated: May 27, 2010

    E-Print Network [OSTI]

    Princeton Plasma Physics Laboratory

    1 NSTX FAILURE MODES AND EFFECTS ANALYSIS (FMEA) Revision 7 Dated: May 27, 2010 Prepared By: Name.07.13 09:11:02 -04'00' #12;NSTX Failure Modes & Effects Analysis / NSTX-FMEA-71-7 / p. 2 of 120 2 Table

  8. Energy Materials & Processes | EMSL

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

    Energy Materials & Processes Overview Atmospheric Aerosol Systems Biosystem Dynamics & Design Energy Materials & Processes Terrestrial & Subsurface Ecosystems Energy Materials &...

  9. Energy Efficiency and Renewables: Market and Behavioral Failures

    ScienceCinema (OSTI)

    James Sweeney

    2010-09-01T23:59:59.000Z

    Thursday, January 28, 2010: Policies to promote renewable energy and energy efficiency have been gaining momentum throughout the world, often justified by environmental and energy security concerns. This presentation first talks about energy efficiency options, then delves into the economic motivation for energy efficiency and renewable energy policies by articulating the classes of relevant behavioral failures and market failures. Such behavioral and market failures may vary intertemporally or atemporally; the temporal structure and the extent of the failures are the critical considerations in the development of energy policies. The talk discusses key policy instruments and assess the extent to which they are well-suited to correct for failures with different structures. http://eetd.lbl.gov/dls/lecture-01-28...

  10. Avoid stainless steel failures in FGD systems

    SciTech Connect (OSTI)

    Mills, J.P.; Schillmoller, C.M.

    1995-11-01T23:59:59.000Z

    Preventing pitting and localized corrosion is the key to success where low maintenance and high reliability are rime considerations in flue-gas desulfurization (FGD) designs. Knowing when to use a stainless steel, and when not to, is crucial. Operating parameters and environmental factors greatly affect alloy performance, especially pH, temperature, and chloride and oxygen levels. Failures of stainless steels can be avoided by understanding their limits in light of these variables. This article will focus on the capabilities of Types 316L, 317L, 317LM, 317LMN, 904L, and 6% Mo stainless steels and their applications, as well as provide details on unique combination of mechanical properties and corrosion resistance of the 22% Cr duplex and 25% Cr super-duplex stainless steels in acid chloride systems. Guidelines will be presented on methods to prevent intergranular corrosion, stress corrosion cracking, and pitting and crevice corrosion, and what process steps can be taken to assure reasonable performance of marginal alloy selections. Emphasis will be on the lime/limestone wet scrubbing process and the quencher/absorber.

  11. Proceedings: International Conference on Boiler Tube Failures and Heat Recovery Steam Generator (HRSG) Tube Failures and Inspections

    SciTech Connect (OSTI)

    None

    2002-10-01T23:59:59.000Z

    Tube failures remain the leading cause of availability loss in conventional fossil plants and combined cycle/heat recovery steam generator (HRSG) plants. These conference proceedings address state-of-the-art practices and techniques worldwide for understanding and reducing tube failures.

  12. Recovery systems must save state before a failure occurs to enable the system to recover from the failure. However,

    E-Print Network [OSTI]

    Chen, Peter M.

    Abstract Recovery systems must save state before a failure occurs to enable the system to recover from the failure. However, recovery will fail if the recovery system saves any state corrupted by the fault. The frequency and comprehensive- ness of how a recovery system saves state has a major effect

  13. Failure Assessment Robyn Lutz, Jet Propulsion Laboratory/Caltech and Iowa State University

    E-Print Network [OSTI]

    Lutz, Robyn R.

    for failure assessment across the system lifecycle with an emphasis on the role of software. For each and characterization both of potential failure mechanisms in systems under development and of actual failure failure mechanisms in systems under development and of actual failure occurrences in operational systems

  14. Alloy materials

    DOE Patents [OSTI]

    Hans Thieme, Cornelis Leo (Westborough, MA); Thompson, Elliott D. (Coventry, RI); Fritzemeier, Leslie G. (Acton, MA); Cameron, Robert D. (Franklin, MA); Siegal, Edward J. (Malden, MA)

    2002-01-01T23:59:59.000Z

    An alloy that contains at least two metals and can be used as a substrate for a superconductor is disclosed. The alloy can contain an oxide former. The alloy can have a biaxial or cube texture. The substrate can be used in a multilayer superconductor, which can further include one or more buffer layers disposed between the substrate and the superconductor material. The alloys can be made a by process that involves first rolling the alloy then annealing the alloy. A relatively large volume percentage of the alloy can be formed of grains having a biaxial or cube texture.

  15. Construction material

    DOE Patents [OSTI]

    Wagh, Arun S. (Orland Park, IL); Antink, Allison L. (Bolingbrook, IL)

    2008-07-22T23:59:59.000Z

    A structural material of a polystyrene base and the reaction product of the polystyrene base and a solid phosphate ceramic is applied as a slurry which includes one or more of a metal oxide or a metal hydroxide with a source of phosphate to produce a phosphate ceramic and a poly (acrylic acid or acrylate) or combinations or salts thereof and polystyrene or MgO applied to the polystyrene base and allowed to cure so that the dried aqueous slurry chemically bonds to the polystyrene base. A method is also disclosed of applying the slurry to the polystyrene base.

  16. Materials Science

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

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645 3,625 1,006 492 742EnergyOnItemResearch > The EnergyCenter (LMI-EFRC) -PublicationsMaterials Science

  17. Material Misfits

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

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Science (SC)Integrated Codes |IsLove Your Home andDisposition | National NuclearMaterial Misfits

  18. Emergence of cooperativity in plasticity of soft glassy materials

    E-Print Network [OSTI]

    Le Bouil Antoine; Amon Axelle; McNamara Sean; Crassous Jérôme

    2014-05-19T23:59:59.000Z

    The elastic coupling between plastic events is generally invoked to interpret plastic properties and failure of amorphous soft glassy materials. We report an experiment where the emergence of a self-organized plastic flow is observed well before the failure. For this we impose an homogeneous stress on a granular material, and measure local deformations for very small strain increments using a light scattering setup. We observe a non-homogeneous strain that appears as transient bands of mesoscopic size and well defined orientation, different from the angle of the macroscopic frictional shear band that appears at failure. The presence and the orientation of those micro-bands may be understood by considering how localized plastic reorganizations redistribute stresses in a surrounding continuous elastic medium. We characterize the lengthscale and persistence of the structure. The presence of plastic events and the mesostructure of the plastic flow are compared to numerical simulations.

  19. GRAIN-SCALE FAILURE IN THERMAL SPALLATION DRILLING

    SciTech Connect (OSTI)

    Walsh, S C; Lomov, I; Roberts, J J

    2012-01-19T23:59:59.000Z

    Geothermal power promises clean, renewable, reliable and potentially widely-available energy, but is limited by high initial capital costs. New drilling technologies are required to make geothermal power financially competitive with other energy sources. One potential solution is offered by Thermal Spallation Drilling (TSD) - a novel drilling technique in which small particles (spalls) are released from the rock surface by rapid heating. While TSD has the potential to improve drilling rates of brittle granitic rocks, the coupled thermomechanical processes involved in TSD are poorly described, making system control and optimization difficult for this drilling technology. In this paper, we discuss results from a new modeling effort investigating thermal spallation drilling. In particular, we describe an explicit model that simulates the grain-scale mechanics of thermal spallation and use this model to examine existing theories concerning spalling mechanisms. We will report how borehole conditions influence spall production, and discuss implications for macro-scale models of drilling systems.

  20. Photovoltaic Materials

    SciTech Connect (OSTI)

    Duty, C.; Angelini, J.; Armstrong, B.; Bennett, C.; Evans, B.; Jellison, G. E.; Joshi, P.; List, F.; Paranthaman, P.; Parish, C.; Wereszczak, A.

    2012-10-15T23:59:59.000Z

    The goal of the current project was to help make the US solar industry a world leader in the manufacture of thin film photovoltaics. The overall approach was to leverage ORNL’s unique characterization and processing technologies to gain a better understanding of the fundamental challenges for solar cell processing and apply that knowledge to targeted projects with industry members. ORNL has the capabilities in place and the expertise required to understand how basic material properties including defects, impurities, and grain boundaries affect the solar cell performance. ORNL also has unique processing capabilities to optimize the manufacturing process for fabrication of high efficiency and low cost solar cells. ORNL recently established the Center for Advanced Thin-film Systems (CATS), which contains a suite of optical and electrical characterization equipment specifically focused on solar cell research. Under this project, ORNL made these facilities available to industrial partners who were interested in pursuing collaborative research toward the improvement of their product or manufacturing process. Four specific projects were pursued with industrial partners: Global Solar Energy is a solar industry leader in full scale production manufacturing highly-efficient Copper Indium Gallium diSelenide (CIGS) thin film solar material, cells and products. ORNL worked with GSE to develop a scalable, non-vacuum, solution technique to deposit amorphous or nanocrystalline conducting barrier layers on untextured stainless steel substrates for fabricating high efficiency flexible CIGS PV. Ferro Corporation’s Electronic, Color and Glass Materials (“ECGM”) business unit is currently the world’s largest supplier of metallic contact materials in the crystalline solar cell marketplace. Ferro’s ECGM business unit has been the world's leading supplier of thick film metal pastes to the crystalline silicon PV industry for more than 30 years, and has had operational cells and modules in the field for 25 years. Under this project, Ferro leveraged world leading analytical capabilities at ORNL to characterize the paste-to-silicon interface microstructure and develop high efficiency next generation contact pastes. Ampulse Corporation is developing a revolutionary crystalline-silicon (c-Si) thin-film solar photovoltaic (PV) technology. Utilizing uniquely-textured substrates and buffer materials from the Oak Ridge National Laboratory (ORNL), and breakthroughs in Hot-Wire Chemical Vapor Deposition (HW-CVD) techniques in epitaxial silicon developed at the National Renewable Energy Laboratory (NREL), Ampulse is creating a solar technology that is tunable in silicon thickness, and hence in efficiency and economics, to meet the specific requirements of multiple solar PV applications. This project focused on the development of a high rate deposition process to deposit Si, Ge, and Si1-xGex films as an alternate to hot-wire CVD. Mossey Creek Solar is a start-up company with great expertise in the solar field. The primary interest is to create and preserve jobs in the solar sector by developing high-yield, low-cost, high-efficiency solar cells using MSC-patented and -proprietary technologies. The specific goal of this project was to produce large grain formation in thin, net-shape-thickness mc-Si wafers processed with high-purity silicon powder and ORNL's plasma arc lamp melting without introducing impurities that compromise absorption coefficient and carrier lifetime. As part of this project, ORNL also added specific pieces of equipment to enhance our ability to provide unique insight for the solar industry. These capabilities include a moisture barrier measurement system, a combined physical vapor deposition and sputtering system dedicated to cadmium-containing deposits, adeep level transient spectroscopy system useful for identifying defects, an integrating sphere photoluminescence system, and a high-speed ink jet printing system. These tools were combined with others to study the effect of defects on the performance of crystalline silicon and

  1. Helium pressures in RHIC vacuum cryostats and relief valve requirements from magnet cooling line failure

    SciTech Connect (OSTI)

    Liaw, C.J.; Than, Y.; Tuozzolo, J.

    2011-03-28T23:59:59.000Z

    A catastrophic failure of the RHIC magnet cooling lines, similar to the LHC superconducting bus failure incident, would pressurize the insulating vacuum in the magnet and transfer line cryostats. Insufficient relief valves on the cryostats could cause a structural failure. A SINDA/FLUINT{reg_sign} model, which simulated the 4.5K/4 atm helium flowing through the magnet cooling system distribution lines, then through a line break into the vacuum cryostat and discharging via the reliefs into the RHIC tunnel, had been developed to calculate the helium pressure inside the cryostat. Arc flash energy deposition and heat load from the ambient temperature cryostat surfaces were included in the simulations. Three typical areas: the sextant arc, the Triplet/DX/D0 magnets, and the injection area, had been analyzed. Existing relief valve sizes were reviewed to make sure that the maximum stresses, caused by the calculated maximum pressures inside the cryostats, did not exceed the allowable stresses, based on the ASME Code B31.3 and ANSYS results. The conclusions are as follows: (1) The S/F simulation results show that the highest internal pressure in the cryostats, due to the magnet line failure, is {approx}37 psig (255115 Pa); (2) Based on the simulation, the temperature on the cryostat chamber, INJ Q8-Q9, could drop to 228 K, which is lower than the material minimum design temperature allowed by the Code; (3) Based on the ASME Code and ANSYS results, the reliefs on all the cryostats inside the RHIC tunnel are adequate to protect the vacuum chambers when the magnet cooling lines fail; and (4) In addition to the pressure loading, the thermal deformations, due to the temperature decrease on the cryostat chambers, could also cause a high stress on the chamber, if not properly supported.

  2. Vulnerability Assessment for Cascading Failures in Electric Power Systems

    SciTech Connect (OSTI)

    Baldick, R.; Chowdhury, Badrul; Dobson, Ian; Dong, Zhao Yang; Gou, Bei; Hawkins, David L.; Huang, Zhenyu; Joung, Manho; Kim, Janghoon; Kirschen, Daniel; Lee, Stephen; Li, Fangxing; Li, Juan; Li, Zuyi; Liu, Chen-Ching; Luo, Xiaochuan; Mili, Lamine; Miller, Stephen; Nakayama, Marvin; Papic, Milorad; Podmore, Robin; Rossmaier, John; Schneider, Kevin P.; Sun, Hongbin; Sun, Kai; Wang, David; Wu, Zhigang; Yao, Liangzhong; Zhang, Pei; Zhang, Wenjie; Zhang, Xiaoping

    2008-09-10T23:59:59.000Z

    Cascading failures present severe threats to power grid security, and thus vulnerability assessment of power grids is of significant importance. Focusing on analytic methods, this paper reviews the state of the art of vulnerability assessment methods in the context of cascading failures in three categories: steady-state modeling based analysis; dynamic modeling analysis; and non-traditional modeling approaches. The impact of emerging technologies including phasor technology, high-performance computing techniques, and visualization techniques on the vulnerability assessment of cascading failures is then addressed, and future research directions are presented.

  3. Cascade Failure in a Phase Model of Power Grids

    E-Print Network [OSTI]

    Sakaguchi, Hidetsugu

    2012-01-01T23:59:59.000Z

    We propose a phase model to study cascade failure in power grids composed of generators and loads. If the power demand is below a critical value, the model system of power grids maintains the standard frequency by feedback control. On the other hand, if the power demand exceeds the critical value, an electric failure occurs via step out (loss of synchronization) or voltage collapse. The two failures are incorporated as two removal rules of generator nodes and load nodes. We perform direct numerical simulation of the phase model on a scale-free network and compare the results with a mean-field approximation.

  4. A simple microscopic model for the dynamics of adhesive failure

    E-Print Network [OSTI]

    Dominic Vella; L. Mahadevan

    2005-12-27T23:59:59.000Z

    We consider a microscopic model for the failure of soft adhesives in tension based on ideas of bond rupture under dynamic loading. Focusing on adhesive failure under loading at constant velocity, we demonstrate that bi-modal curves of stress against strain may occur due to effects of finite polymer chain or bond length and characterise the loading conditions under which such bi-modal behaviour is observed. The results of this analysis are in qualitative agreement with experiments performed on unconfined adhesives in which failure does not occur by cavitation.

  5. Cascading dynamics and mitigation assessment in power system disturbances via a hidden failure model

    E-Print Network [OSTI]

    Dobson, Ian

    system reliability; Protective relaying hidden failures; Blackout mitigation 1. Introduction, which is often referred to as a hidden failure [7]. Hidden failures in protective relays disturbances involved relaying systems, not necessarily as the initiating event, but contributing

  6. Tackling nanoscale IC failures through noise-aware testing and silicon debugging

    E-Print Network [OSTI]

    Chen, Mingjing; Chen, Mingjing

    2012-01-01T23:59:59.000Z

    architecture failure analysis . . . . . . 2.3.1 Scan chainon Testing and Failure Analysis, pages [93] G. Strang.Electronic Device Failure Analysis, 7(1):16–24, 2005. [24

  7. Materials Characterization | Advanced Materials | ORNL

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

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOEThe Bonneville PowerCherries 82981-1cnHighand Retrievals from a New 183-GHzMAR Os2010Material Safety Electron

  8. Graduate Students Associated with the Materials and Process Mechanics Laboratory

    E-Print Network [OSTI]

    Graduate Students Associated with the Materials and Process Mechanics Laboratory Date Degree Coatings 1996 M.Eng. J. van de Vegte Automated Adhesive Bonding of Stator Magnets 1996 M.A.Sc. J. Wylde Characterization of Aluminum Alloys in a Vibratory Finishing Process 2002 M.A.Sc. S. Sareskani Adhesive Failure

  9. Congestive heart failure: treat the disease, not the symptom: return to normalcy/Part II--the experimental approach.

    E-Print Network [OSTI]

    Buckberg, Gerald D

    2007-01-01T23:59:59.000Z

    Number: Title: Congestive heart failure: treat the diseaseinvited) TITLE: Congestive heart failure: treat the diseasetreatment of congestive heart failure due to post-infarction

  10. Critical Materials Institute

    SciTech Connect (OSTI)

    Alex King

    2013-01-09T23:59:59.000Z

    Ames Laboratory Director Alex King talks about the goals of the Critical Materials Institute in diversifying the supply of critical materials, developing substitute materials, developing tools and techniques for recycling critical materials, and forecasting materials needs to avoid future shortages.

  11. Critical Materials Institute

    ScienceCinema (OSTI)

    Alex King

    2013-06-05T23:59:59.000Z

    Ames Laboratory Director Alex King talks about the goals of the Critical Materials Institute in diversifying the supply of critical materials, developing substitute materials, developing tools and techniques for recycling critical materials, and forecasting materials needs to avoid future shortages.

  12. HAZARDOUS MATERIALS INCIDENTS What are hazardous materials?

    E-Print Network [OSTI]

    Fernandez, Eduardo

    HAZARDOUS MATERIALS INCIDENTS What are hazardous materials? Hazardous materials are chemicals, accidentally spilled, or released. In addition to laboratory chemicals, hazardous materials may include common not involve highly toxic or noxious hazardous materials, a fire, or an injury requiring medical attention

  13. HAZARDOUS MATERIALS INCIDENTS What are hazardous materials?

    E-Print Network [OSTI]

    Fernandez, Eduardo

    HAZARDOUS MATERIALS INCIDENTS What are hazardous materials? Hazardous materials are chemicals I do if there is a small spill in the area and personnel trained in Hazardous Material clean up, or there is a small spill where personnel trained in Hazardous Material clean up or an appropriate spill kit

  14. HAZARDOUS MATERIALS INCIDENTS What are hazardous materials?

    E-Print Network [OSTI]

    Fernandez, Eduardo

    HAZARDOUS MATERIALS INCIDENTS What are hazardous materials? Hazardous materials are chemicals I do if there is a small spill in the area and personnel trained in Hazardous Material clean up spill where personnel trained in Hazardous Material clean up or an appropriate spill kit

  15. HAZARDOUS MATERIALS INCIDENTS What are hazardous materials?

    E-Print Network [OSTI]

    Fernandez, Eduardo

    HAZARDOUS MATERIALS INCIDENTS What are hazardous materials? Hazardous materials are chemicals I do if there is a small spill in the area and personnel trained in Hazardous Material clean up personnel trained in Hazardous Material clean up or an appropriate spill kit is not available? Call 561

  16. DYNAMIC FAILURE OF METALLIC CELLULAR MATERIALS S. LEE and H.D. ESPINOSA

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    interest in the protection design in automotive, locomotive, naval structures, and aerospace. Metallic not observe any rate dependency for the crashing stress of aluminum foams. These discrepancies from different within the specimen at very high strain rates. A model for shock waves in closed cell aluminum foams

  17. Failure of the Shockley-Haynes Mobility Experiment with organic semiconducting materials 

    E-Print Network [OSTI]

    Boehme, Hollis Clyde

    1961-01-01T23:59:59.000Z

    of the teflon cylinder was 0. 20$ cm + 0. 00$ cm whioh was slight- ly smaller than the graphite rods used, This arrapgement provided an airtight seal to prevent the sublimation of iodine from the samples after pressing Small holes were drilled through...-iodine was lower than that reported, The upper limit of 3000 lb/i. n for the pressure used to 2 oompress the samples was dictated by the graphite rods used and the wall thickness of the teflon oylinders. Pressures above $000 lb/in oaused either the ends...

  18. Dynamic failure of metallic pyramidal truss core materials Experiments and modeling

    E-Print Network [OSTI]

    Barthelat, Francois

    ) buckling induced lateral motion. These findings are con- sistent with prior theoretical and computational and buckling of truss struts played a significant role. This effect appears to dominate the early truss core plastic wave propagation and column buckling. Journal of Applied Mechanics 72 (1), 1­8]. At larger

  19. Real-Time Quantitative Imaging of Failure Events in Materials Under Load at

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

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  20. Title Slide "Avoiding expensive IT project and product failures

    E-Print Network [OSTI]

    Hatton, Les

    Title Slide "Avoiding expensive IT project and product failures In 21st century healthcare and potential recall of 1 million of its best-selling Camry and Lexus ES300 sedans because of reports

  1. Considerations in Dealing with the Risk of a Compressor Failure

    E-Print Network [OSTI]

    Beals, C. E.

    2007-01-01T23:59:59.000Z

    Many plants do not have sufficient backup compressor capacity and risk having production outages due to compressor failures. Today, system designs are available that can eliminate this risk; however, there is a cost associated with doing so...

  2. Performance of wireless sensor networks under random node failures

    SciTech Connect (OSTI)

    Bradonjic, Milan [Los Alamos National Laboratory; Hagberg, Aric [Los Alamos National Laboratory; Feng, Pan [Los Alamos National Laboratory

    2011-01-28T23:59:59.000Z

    Networks are essential to the function of a modern society and the consequence of damages to a network can be large. Assessing network performance of a damaged network is an important step in network recovery and network design. Connectivity, distance between nodes, and alternative routes are some of the key indicators to network performance. In this paper, random geometric graph (RGG) is used with two types of node failure, uniform failure and localized failure. Since the network performance are multi-facet and assessment can be time constrained, we introduce four measures, which can be computed in polynomial time, to estimate performance of damaged RGG. Simulation experiments are conducted to investigate the deterioration of networks through a period of time. With the empirical results, the performance measures are analyzed and compared to provide understanding of different failure scenarios in a RGG.

  3. Statistical Modeling of Corrosion Failures in Natural Gas Transmission Pipelines 

    E-Print Network [OSTI]

    Cobanoglu, Mustafa Murat

    2014-03-28T23:59:59.000Z

    Natural gas pipelines are a critical component of the U.S. energy infrastructure. The safety of these pipelines plays a key role for the gas industry. Therefore, the understanding of failure characteristics and their consequences are very important...

  4. Quality of Service of Crash-Recovery Failure Detectors 

    E-Print Network [OSTI]

    Ma, Tiejun

    2007-11-07T23:59:59.000Z

    problem when the monitored target is resilient and recovers after failure. To the best of our knowledge, this is the first work to provide an analysis of crash-recovery failure detection from the QoS perspective....We develop a probabilistic model of the behavior of a crash-recovery target, i.e. one which has the ability to recover from the crash state. We show that the fail-free run and the crash-stop run are special cases of the crash-recovery run with mean time to failure (MTTF) approaching to infinity and mean time to recovery (MTTR) approaching to infinity, respectively. We extend the previously published QoS metrics to allow the measurement of the recovery speed, and the definition of the completeness property of a failure detector. Then, the impact of the dependability of the crash-recovery target on the QoS bounds for such a crash-recovery failure detector is analyzed using general dependability metrics, such as MTTF and MTTR, based on an approximate probabilistic model of the two-process failure detection system. Then according to our approximate model, we show how to estimate the failure detector’s parameters to achieve a required QoS, based on Chen et al.’s NFD-S algorithm analytically, and how to execute the configuration procedure of this crash-recovery failure detector....In order to make the failure detector adaptive to the target’s crash-recovery behavior and enable the autonomy of the monitoring procedure, we propose two types of recovery detection protocols. One is a reliable recovery detection protocol, which can guarantee to detect each occurring failure and recovery by adopting persistent storage. The other is a lightweight recovery detection protocol, which does not guarantee to detect every failure and recovery but which reduces the system overhead. Both of these recovery detection protocols improve the completeness without reducing the other QoS aspects of a failure detector. In addition, we also demonstrate how to estimate the inputs, such as the dependability metrics, using the failure detector itself....In order to evaluate our analytical work, we simulate the following failure detection algorithms: the simple heartbeat timeout algorithm, the NFD-S algorithm and the NFDS algorithm with the lightweight recovery detection protocol, for various values of MTTF and MTTR. The simulation results show that the dependability of a recoverable monitored target could have significant impact on the QoS of such a failure detector. This conforms well to our models and analysis. We show that in the case of reasonable long MTTF, the NFD-S algorithm with the lightweight recovery detection protocol exhibits better QoS than the NFD-S algorithm for the completeness of a crash-recovery failure detector, and similarly for other QoS metrics....

  5. Making Sense of the Social Aspects of Business Failure 

    E-Print Network [OSTI]

    Heinze, Ilka

    2011-11-23T23:59:59.000Z

    by interpretative phenomenological analysis (IPA). Emergent themes were the entrepreneurs’ self incorporating values and motivations, their grief and suffering in the aftermath of failure, feelings of betrayal and frustration, financial worries, learning...

  6. Terrestrial Photovoltaic Module Accelerated Test-To-Failure Protocol

    SciTech Connect (OSTI)

    Osterwald, C. R.

    2008-03-01T23:59:59.000Z

    This technical report documents a test-to-failure protocol that may be used to obtain quantitative information about the reliability of photovoltaic modules using accelerated testing in environmental temperature-humidity chambers.

  7. Failure Mode and Sensitivity Analysis of Gas Lift Valves

    E-Print Network [OSTI]

    Gilbertson, Eric W.

    Gas-lifted oil wells are susceptible to failure through malfunction of gas lift valves. This is a growing concern as offshore wells are drilled thousands of meters below the ocean floor in extreme temperature and pressure ...

  8. Mechanistic fracture criteria for the failure of human cortical bone

    SciTech Connect (OSTI)

    Nalla, Ravi K.; Kinney, John H.; Ritchie, Robert O.

    2002-12-13T23:59:59.000Z

    A mechanistic understanding of fracture in human bone is critical to predicting fracture risk associated with age and disease. Despite extensive work, a mechanistic framework for describing how the underlying microstructure affects the failure mode in bone is lacking.

  9. Technology platform development for targeted plasma metabolites in human heart failure

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    statement from the American Heart Association. CirculationHospitalizations after heart failure diagnosis a communityof and survival with heart failure. N Eng J Med 2002, 347:

  10. Localization and activation of CaMKII delta isoforms and their involvement in heart failure

    E-Print Network [OSTI]

    Mishra, Shikha

    2010-01-01T23:59:59.000Z

    hypertrophy and heart failure ..CaMKII mediated hypertrophy and heart failure .. I.F.II.C. Preparation of heart tissue extract and cell lysate

  11. Compression-induced failure of electro-active polymeric thin films

    E-Print Network [OSTI]

    Domenico De Tommasi; Giuseppe Puglisi; Giuseppe Zurlo

    2010-12-07T23:59:59.000Z

    The insurgence of compression induces wrinkling in actuation devices based on EAPs thin films leading to a sudden decrease of performances up to failure. Based on the classical tension field theory for thin elastic membranes, we provide a general framework for the analysis of the insurgence of in-plane compression in membranes of electroactive polymers (EAPs). Our main result is the deduction of a (voltage-dependent) domain in the stretch space which represents tensile configurations. Under the assumption of Mooney-Rivlin materials, we obtain that for growing values of the applied voltage the domain contracts, vanishing at a critical voltage above which the polymer is wrinkled for any stretch configuration. Our approach can be easily implemented in numerical simulations for more complex material behaviors and provides a tool for the analysis of compression instability as a function of the elastic moduli.

  12. Three essays on business failure: causality and prediction

    E-Print Network [OSTI]

    Zhang, Jin

    2009-05-15T23:59:59.000Z

    such factor (Altman and Izan (1984), Izan (1984), Platt and Platt (1990, 1991), Chava and Jarrow (2004)). Macroeconomic environment represents another factor external to firm. Economic intuitions tend to suggest that the occurrence of business failures... on the shutting down condition in neoclassic microeconomic theory, Platt and Platt (1994) assumed aggregate corporate failure as a function of general cost and economic conditions (revenue benchmark). Across all the differing frameworks, the empirical...

  13. Prioritizing Water Pipe Replacement and Rehabilitation by Evaluating Failure Risk

    E-Print Network [OSTI]

    Lee, Sang Hyun

    2012-02-14T23:59:59.000Z

    PRIORITIZING WATER PIPE REPLACEMENT AND REHABILITATION BY EVALUATING FAILURE RISK A Thesis by SANG HYUN LEE Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... 2011 Sang Hyun Lee PRIORITIZING WATER PIPE REPLACEMENT AND REHABILITATION BY EVALUATING FAILURE RISK A Thesis by SANG HYUN LEE Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment...

  14. MATERIALS MANAGEMENT MATERIALS MANAGEMENT -INVENTORY CONTROL

    E-Print Network [OSTI]

    Oliver, Douglas L.

    MATERIALS MANAGEMENT MATERIALS MANAGEMENT - INVENTORY CONTROL Record of Property Transferred from ______ ___________________________________ 2. DEAN (If Applies) ______ ___________________________________ 5. UNIVERSITY DIRECTOR OF MATERIALS MANAGEMENT ______ ___________________________________ 3. HOSPITAL DIRECTOR (If Applies) ______ IF YOU NEED

  15. Gas storage materials, including hydrogen storage materials

    DOE Patents [OSTI]

    Mohtadi, Rana F; Wicks, George G; Heung, Leung K; Nakamura, Kenji

    2014-11-25T23:59:59.000Z

    A material for the storage and release of gases comprises a plurality of hollow elements, each hollow element comprising a porous wall enclosing an interior cavity, the interior cavity including structures of a solid-state storage material. In particular examples, the storage material is a hydrogen storage material, such as a solid state hydride. An improved method for forming such materials includes the solution diffusion of a storage material solution through a porous wall of a hollow element into an interior cavity.

  16. Gas storage materials, including hydrogen storage materials

    DOE Patents [OSTI]

    Mohtadi, Rana F; Wicks, George G; Heung, Leung K; Nakamura, Kenji

    2013-02-19T23:59:59.000Z

    A material for the storage and release of gases comprises a plurality of hollow elements, each hollow element comprising a porous wall enclosing an interior cavity, the interior cavity including structures of a solid-state storage material. In particular examples, the storage material is a hydrogen storage material such as a solid state hydride. An improved method for forming such materials includes the solution diffusion of a storage material solution through a porous wall of a hollow element into an interior cavity.

  17. Functional Materials for Energy | Advanced Materials | ORNL

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

    Energy Storage Fuel Cells Thermoelectrics Separations Materials Catalysis Sensor Materials Polymers and Composites Carbon Fiber Related Research Chemistry and Physics at...

  18. An Attempt to Calibrate and Validate a Simple Ductile Failure Model Against Axial-Torsion Experiments on Al 6061-T651.

    SciTech Connect (OSTI)

    Reedlunn, Benjamin; Lu, Wei-Yang [Sandia National Laboratories, Livermore, CA

    2015-01-01T23:59:59.000Z

    This report details a work in progress. We have attempted to calibrate and validate a Von Mises plasticity model with the Johnson-Cook failure criterion ( Johnson & Cook , 1985 ) against a set of experiments on various specimens of Al 6061-T651. As will be shown, the effort was not successful, despite considerable attention to detail. When the model was com- pared against axial-torsion experiments on tubes, it over predicted failure by 3 x in tension, and never predicted failure in torsion, even when the tube was twisted by 4 x further than the experiment. While this result is unfortunate, it is not surprising. Ductile failure is not well understood. In future work, we will explore whether more sophisticated material mod- els of plasticity and failure will improve the predictions. Selecting the appropriate advanced material model and interpreting the results of said model are not trivial exercises, so it is worthwhile to fully investigate the behavior of a simple plasticity model before moving on to an anisotropic yield surface or a similarly complicated model.

  19. Materials Project: A Materials Genome Approach

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Ceder, Gerbrand (MIT); Persson, Kristin (LBNL)

    Technological innovation - faster computers, more efficient solar cells, more compact energy storage - is often enabled by materials advances. Yet, it takes an average of 18 years to move new materials discoveries from lab to market. This is largely because materials designers operate with very little information and must painstakingly tweak new materials in the lab. Computational materials science is now powerful enough that it can predict many properties of materials before those materials are ever synthesized in the lab. By scaling materials computations over supercomputing clusters, this project has computed some properties of over 80,000 materials and screened 25,000 of these for Li-ion batteries. The computations predicted several new battery materials which were made and tested in the lab and are now being patented. By computing properties of all known materials, the Materials Project aims to remove guesswork from materials design in a variety of applications. Experimental research can be targeted to the most promising compounds from computational data sets. Researchers will be able to data-mine scientific trends in materials properties. By providing materials researchers with the information they need to design better, the Materials Project aims to accelerate innovation in materials research.[copied from http://materialsproject.org/about] You will be asked to register to be granted free, full access.

  20. JOURNAL OF MECHANICS OF MATERIALS AND STRUCTURES Vol. 3, No. 7, 2008

    E-Print Network [OSTI]

    Wadley, Haydn

    materials, composites, microbuckling, honeycomb, carbon fiber, carbon fibre. 1315 #12;1316 BENJAMIN P. WADLEY Carbon fibre epoxy matrix composite honeycombs have been fabricated by slotting, assembling modes were elastic buckling or shear failure of the composite sheet material. Analytical models

  1. MATERIALS MANAGEMENT MATERIALS MANAGEMENT -INVENTORY CONTROL

    E-Print Network [OSTI]

    Oliver, Douglas L.

    MATERIALS MANAGEMENT MATERIALS MANAGEMENT - INVENTORY CONTROL NOTICE OF DESIGNATED DEPARTMENTAL OF MATERIALS MANAGEMENT ______ FURTHER INSTRUCTIONS 1. Include a copy of any relevant documents. 2. Item MATERIALS COORDINATOR ­ IC-8 Mail, Fax or PDF the entire package to: MC 2010 Fax: 679-4240 REFERENCE # DMC

  2. DREDGED MATERIAL EVALUATION AND

    E-Print Network [OSTI]

    DREDGED MATERIAL EVALUATION AND DISPOSAL PROCEDURES (USERS' MANUAL) Dredged Material Management 2009) Prepared by: Dredged Material Management Office US Army Corps of Engineers Seattle District #12........................................................................................2-1 2.2 The Dredged Material Evaluation Process

  3. Analysis of Dam Failure in the Saluda River February 8, 2005

    E-Print Network [OSTI]

    Morrow, James A.

    Analysis of Dam Failure in the Saluda River Valley February 8, 2005 Abstract We identify and model two possible failure modes for the Saluda Dam: gradual failure due to an enlarging breach and sudden catas- trophic failure due to liqui#12;cation of the dam. For the #12;rst case we de- scribe the breach

  4. Failure Modes of Vacuum Plasma Spray Tungsten Coating Created on Carbon Fibre Composites under Thermal Loads

    E-Print Network [OSTI]

    Failure Modes of Vacuum Plasma Spray Tungsten Coating Created on Carbon Fibre Composites under Thermal Loads

  5. Testing branching process estimators of cascading failure with data from a

    E-Print Network [OSTI]

    Dobson, Ian

    the propagation of cascading transmission line failures in large blackouts of electric power systems. We use power transmission system, infrastructure I. INTRODUCTION Cascading failure is a sequence of dependent failures that successively weaken a system. In electric power transmission systems, cascading failure

  6. Development of chemical vapor composites, CVC materials. Final report

    SciTech Connect (OSTI)

    NONE

    1998-10-05T23:59:59.000Z

    Industry has a critical need for high-temperature operable ceramic composites that are strong, non-brittle, light weight, and corrosion resistant. Improvements in energy efficiency, reduced emissions and increased productivity can be achieved in many industrial processes with ceramic composites if the reaction temperature and pressure are increased. Ceramic composites offer the potential to meet these material requirements in a variety of industrial applications. However, their use is often restricted by high cost. The Chemical Vapor composite, CVC, process can reduce the high costs and multiple fabrication steps presently required for ceramic fabrication. CVC deposition has the potential to eliminate many difficult processing problems and greatly increase fabrication rates for composites. With CVC, the manufacturing process can control the composites` density, microstructure and composition during growth. The CVC process: can grow or deposit material 100 times faster than conventional techniques; does not require an expensive woven preform to infiltrate; can use high modulus fibers that cannot be woven into a preform; can deposit composites to tolerances of less than 0.025 mm on one surface without further machining.

  7. Method for forming materials

    DOE Patents [OSTI]

    Tolle, Charles R. (Idaho Falls, ID); Clark, Denis E. (Idaho Falls, ID); Smartt, Herschel B. (Idaho Falls, ID); Miller, Karen S. (Idaho Falls, ID)

    2009-10-06T23:59:59.000Z

    A material-forming tool and a method for forming a material are described including a shank portion; a shoulder portion that releasably engages the shank portion; a pin that releasably engages the shoulder portion, wherein the pin defines a passageway; and a source of a material coupled in material flowing relation relative to the pin and wherein the material-forming tool is utilized in methodology that includes providing a first material; providing a second material, and placing the second material into contact with the first material; and locally plastically deforming the first material with the material-forming tool so as mix the first material and second material together to form a resulting material having characteristics different from the respective first and second materials.

  8. Statistical analysis of cascading failures in power grids

    SciTech Connect (OSTI)

    Chertkov, Michael [Los Alamos National Laboratory; Pfitzner, Rene [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory

    2010-12-01T23:59:59.000Z

    We introduce a new microscopic model of cascading failures in transmission power grids. This model accounts for automatic response of the grid to load fluctuations that take place on the scale of minutes, when optimum power flow adjustments and load shedding controls are unavailable. We describe extreme events, caused by load fluctuations, which cause cascading failures of loads, generators and lines. Our model is quasi-static in the causal, discrete time and sequential resolution of individual failures. The model, in its simplest realization based on the Directed Current description of the power flow problem, is tested on three standard IEEE systems consisting of 30, 39 and 118 buses. Our statistical analysis suggests a straightforward classification of cascading and islanding phases in terms of the ratios between average number of removed loads, generators and links. The analysis also demonstrates sensitivity to variations in line capacities. Future research challenges in modeling and control of cascading outages over real-world power networks are discussed.

  9. Intensity-Modulated Radiotherapy for Tumors of the Nasal Cavity and Paranasal Sinuses: Clinical Outcomes and Patterns of Failure

    SciTech Connect (OSTI)

    Wiegner, Ellen A.; Daly, Megan E.; Murphy, James D.; Abelson, Jonathan; Chapman, Chris H.; Chung, Melody; Yu, Yao; Colevas, A. Dimitrios; Kaplan, Michael J.; Fischbein, Nancy; Le, Quynh-Thu [Department of Radiation Oncology, Stanford University, Stanford, CA (United States); Chang, Daniel T., E-mail: dtchang@stanford.edu [Department of Radiation Oncology, Stanford University, Stanford, CA (United States)

    2012-05-01T23:59:59.000Z

    Purpose: To report outcomes in patients treated with intensity-modulated radiotherapy (IMRT) for tumors of the paranasal sinuses and nasal cavity (PNS/NC). Methods/Materials: Between June 2000 and December 2009, 52 patients with tumors of the PNS/NC underwent postoperative or definitive radiation with IMRT. Twenty-eight (54%) patients had squamous cell carcinoma (SCC). Twenty-nine patients (56%) received chemotherapy. The median follow-up was 26.6 months (range, 2.9-118.4) for all patients and 30.9 months for living patients. Results: Eighteen patients (35%) developed local-regional failure (LRF) at median time of 7.2 months. Thirteen local failures (25%) were observed, 12 in-field and 1 marginal. Six regional failures were observed, two in-field and four out-of-field. No patients treated with elective nodal radiation had nodal regional failure. Two-year local-regional control (LRC), in-field LRC, freedom from distant metastasis (FFDM), and overall survival (OS) were 64%, 74%, 71%, and 66% among all patients, respectively, and 43%, 61%, 61%, and 53% among patients with SCC, respectively. On multivariate analysis, SCC and >1 subsite involved had worse LRC (p = 0.0004 and p = 0.046, respectively) and OS (p = 0.003 and p = 0.046, respectively). Cribriform plate invasion (p = 0.005) and residual disease (p = 0.047) also had worse LRC. Acute toxicities included Grade {>=}3 mucositis in 19 patients (37%), and Grade 3 dermatitis in 8 patients (15%). Six patients had Grade {>=}3 late toxicity including one optic toxicity. Conclusions: IMRT for patients with PNS/NC tumors has good outcomes compared with historical series and is well tolerated. Patients with SCC have worse LRC and OS. LRF is the predominant pattern of failure.

  10. Failure of linear control in noisy coupled map lattices

    E-Print Network [OSTI]

    David A. Egolf; Joshua E. S. Socolar

    1997-12-21T23:59:59.000Z

    We study a 1D ring of diffusively coupled logistic maps in the vicinity of an unstable, spatially homogeneous fixed point. The failure of linear controllers due to additive noise is discussed with the aim of clarifying the failure mechanism. A criterion is suggested for estimating the noise level that can be tolerated by the given controller. The criterion implies the loss of control for surprisingly low noise levels in certain cases of interest, and accurately accounts for the results of numerical experiments over a broad range of parameter values. Previous results of Grigoriev, et al (Phys. Rev. Lett., 79, 2795) are reviewed and compared with our numerical and analytical results.

  11. A Précis of Some Recent Developments in Computational Failure Mechanics

    E-Print Network [OSTI]

    De Borst, R; Askes, Harm; Gutiérrez, Miguel A; Remmers, Joris J C; Wells, G N

    2002-01-01T23:59:59.000Z

    WCCM V Fifth World Congress on Computational Mechanics July 7-12, 2002, Vienna, Austria Eds.: H.A. Mang, F.G. Rammerstorfer, J. Eberhardsteiner A Pre´cis of Some Recent Developments in Computational Failure Mechanics Rene´ de Borst*, Harm Askes... transition from a (higher-order) continuum description to a genuine discontinuum in a numerical context. This is ex- tremely powerful, since now the entire failure process, from small-scale yielding or the initiation of voids and micro-cracks up...

  12. Failure of sheathed thermocouples due to thermal cycling

    SciTech Connect (OSTI)

    Anderson, R.L.; Ludwig, R.L.

    1982-03-01T23:59:59.000Z

    Open circuit failures (up to 100%) in small-diameter thermocouples used in electrically heated nuclear fuel rod simulator prototypes during thermal cycling tests were investigated to determine the cause(s) of the failures. The experiments conducted to determine the relative effects of differential thermal expansion, wire size, grain size, and manufacturing technology are described. It was concluded that the large grain size and embrittlement which result from certain common manufacturing annealing and drawing procedures were a major contributing factor in the breakage of the thermocouple wires.

  13. Ground control failures. A pictorial view of case studies

    SciTech Connect (OSTI)

    Peng, S.S.

    2007-07-01T23:59:59.000Z

    The book shows, in pictorial views, many forms and/or stages of types of failures in mines, for instance, cutter, roof falls, and cribs. In each case, the year of occurrence is stated in the beginning so that the environment or technological background under which it occurred are reflected. The narrative than begins with the mining and geological conditions, followed by a description of the ground control problems and recommended solutions and results, if any. The sections cover failure of pillars, roof falls, longwall, roof bolting, multiple-seam mining, floor heave, longwall, flooding and weathering of coal, old workings, and shortwall and thin-seam plow longwall.

  14. Updated Results and Patterns of Failure in a Randomized Hypofractionation Trial for High-risk Prostate Cancer

    SciTech Connect (OSTI)

    Arcangeli, Stefano [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy)] [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy); Strigari, Lidia [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome (Italy)] [Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome (Italy); Gomellini, Sara; Saracino, Biancamaria; Petrongari, Maria Grazia; Pinnaro, Paola; Pinzi, Valentina [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy)] [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy); Arcangeli, Giorgio, E-mail: arcangeli.gio@tiscali.it [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy)] [Department of Radiation Oncology, Regina Elena National Cancer Institute, Rome (Italy)

    2012-12-01T23:59:59.000Z

    Purpose: To report long-term results and patterns of failure after conventional and hypofractionated radiation therapy in high-risk prostate cancer. Methods and Materials: This randomized phase III trial compared conventional fractionation (80 Gy at 2 Gy per fraction in 8 weeks) vs hypofractionation (62 Gy at 3.1 Gy per fraction in 5 weeks) in combination with 9-month androgen deprivation therapy in 168 patients with high-risk prostate cancer. Freedom from biochemical failure (FFBF), freedom from local failure (FFLF), and freedom from distant failure (FFDF) were analyzed. Results: In a median follow-up of 70 months, biochemical failure (BF) occurred in 35 of the 168 patients (21%) in the study. Among these 35 patients, local failure (LF) only was detected in 11 (31%), distant failure (DF) only in 16 (46%), and both LF and DF in 6 (17%). In 2 patients (6%) BF has not yet been clinically detected. The risk reduction by hypofractionation was significant in BF (10.3%) but not in LF and DF. We found that hypofractionation, with respect to conventional fractionation, determined only an insignificant increase in the actuarial FFBF but no difference in FFLF and FFDF, when considering the entire group of patients. However, an increase in the 5-year rates in all 3 endpoints-FFBF, FFLF, and FFDF-was observed in the subgroup of patients with a pretreatment prostate-specific antigen (iPSA) level of 20 ng/mL or less. On multivariate analysis, the type of fractionation, iPSA level, Gleason score of 4+3 or higher, and T stage of 2c or higher have been confirmed as independent prognostic factors for BF. High iPSA levels and Gleason score of 4+3 or higher were also significantly associated with an increased risk of DF, whereas T stage of 2c or higher was the only independent variable for LF. Conclusion: Our results confirm the isoeffectiveness of the 2 fractionation schedules used in this study, although a benefit in favor of hypofractionation cannot be excluded in the subgroup of patients with an iPSA level of 20 ng/mL or less. The {alpha}/{beta} ratio might be more appropriately evaluated by FFLF than FFBF results, at least in high-risk disease.

  15. Method for recycling tires and similarly compounded materials to recover usable constituents

    SciTech Connect (OSTI)

    Letsch, W.

    1980-12-23T23:59:59.000Z

    A processing plant and method are described for processing scrap tires and similar materials containing a mixture of technical rubber, scrap metal and tire cord in which the plant is essentially vehicular and thus eliminates the necessity of hauling accumulated tires long distances with the accompanying costs. The plant includes means for directing mixed tire sizes to a cyrogenic section where the technical rubber is reduced to a sufficient temperature making it brittle so that initial separation of reusable technical rubber is accomplished; the plant is operated essentially on the reusable by-products of pyrolytic reduction of the tires so that hydrocarbons and heated gas are utilized and additional commercial by-products such as commercial soots, metal and tire beads are obtained.

  16. On-Line Thermal Barrier Coating Monitoring for Real-Time Failure Protection and Life Maximization

    SciTech Connect (OSTI)

    Dennis H. LeMieux

    2005-04-01T23:59:59.000Z

    Under the sponsorship of the U. S. Department of Energy's National Energy Laboratory, Siemens Westinghouse Power Corporation proposes a four year program titled, ''On-Line Thermal Barrier Coating (TBC) Monitor for Real-Time Failure Protection and Life Maximization'', to develop, build and install the first generation of an on-line TBC monitoring system for use on land-based advanced gas turbines (AGT). Federal deregulation in electric power generation has accelerated power plant owner's demand for improved reliability availability maintainability (RAM) of the land-based advanced gas turbines. As a result, firing temperatures have been increased substantially in the advanced turbine engines, and the TBCs have been developed for maximum protection and life of all critical engine components operating at these higher temperatures. Losing TBC protection can therefore accelerate the degradation of substrate components materials and eventually lead to a premature failure of critical component and costly unscheduled power outages. This program seeks to substantially improve the operating life of high cost gas turbine components using TBC; thereby, lowering the cost of maintenance leading to lower cost of electricity. Siemens Westinghouse Power Corporation has teamed with Indigo Systems, a supplier of state-of-the-art infrared camera systems, and Wayne State University, a leading research organization in the field of infrared non-destructive examination (NDE), to complete the program.

  17. Development and deployment of constitutive softening routines in Eulerian hydrocodes.

    SciTech Connect (OSTI)

    Fuller, Timothy Jesse; Dewers, Thomas A.; Swan, Matthew Scot

    2013-03-01T23:59:59.000Z

    The state of the art in failure modeling enables assessment of crack nucleation, propagation, and progression to fragmentation due to high velocity impact. Vulnerability assessments suggest a need to track material behavior through failure, to the point of fragmentation and beyond. This eld of research is particularly challenging for structures made of porous quasi-brittle materials, such as ceramics used in modern armor systems, due to the complex material response when loading exceeds the quasi-brittle material's elastic limit. Further complications arise when incorporating the quasi-brittle material response in multi-material Eulerian hydrocode simulations. In this report, recent e orts in coupling a ceramic materials response in the post-failure regime with an Eulerian hydro code are described. Material behavior is modeled by the Kayenta material model [2]and Alegra as the host nite element code [14]. Kayenta, a three invariant phenomenological plasticity model originally developed for modeling the stress response of geologic materials, has in recent years been used with some success in the modeling of ceramic and other quasi-brittle materials to high velocity impact. Due to the granular nature of ceramic materials, Kayenta allows for signi cant pressures to develop due to dilatant plastic ow, even in shear dominated loading where traditional equations of state predict little or no pressure response. When a material's ability to carry further load is compromised, Kayenta allows the material's strength and sti ness to progressively degrade through the evolution of damage to the point of material failure. As material dilatation and damage progress, accommodations are made within Alegra to treat in a consistent manner the evolving state.

  18. Gradient effects on the fracture of inhomogeneous materials

    SciTech Connect (OSTI)

    Becker, T.L.

    2000-05-01T23:59:59.000Z

    Functionally Graded Materials (FGMs) have a spatial variation in physical properties that can be tailored to meet the needs of a specific application and/or to minimize internal stresses arising from thermal and elastic mismatch. Modeling these materials as inhomogeneous continua allows assessment of the role of the gradient without requiring detailed knowledge of the microstructure. Motivated by the relative difficulty of obtaining analytical solutions to boundary value problems for FGMs, an accurate finite-element code is developed for obtaining numerical planar and axisymmetric linear thermoelastic solutions. In addition an approximate analytical technique for mapping homogeneous-modulus solutions to those for FGMs is assessed and classes of problems to which it applies accurately are identified. The fracture mechanics analysis of FGMs can be characterized by the classic stress intensities, KI and KII, but there has been scarce progress in understanding the role of the modulus gradient in determining fracture initiation and propagation. To address this question, a statistical fracture model is used to correlate near-tip stresses with brittle fracture initiation behavior. This describes the behavior of a material experiencing fracture initiation away from the crack tip. Widely dispersed zones of fracture initiation sites are expected. Finite-length kinks are analyzed to describe the crack path for continuous crack growth. For kink lengths much shorter than the gradient dimension, a parallel stress term describes the deviation of the kinking angle from that for homogeneous materials. For longer kinks there is a divergence of the kink angle predicted by the maximum energy release rate and the pure opening mode criteria.

  19. Transporting particulate material

    DOE Patents [OSTI]

    Aldred, Derek Leslie (North Hollywood, CA); Rader, Jeffrey A. (North Hollywood, CA); Saunders, Timothy W. (North Hollywood, CA)

    2011-08-30T23:59:59.000Z

    A material transporting system comprises a material transporting apparatus (100) including a material transporting apparatus hopper structure (200, 202), which comprises at least one rotary transporting apparatus; a stationary hub structure (900) constraining and assisting the at least one rotary transporting apparatus; an outlet duct configuration (700) configured to permit material to exit therefrom and comprising at least one diverging portion (702, 702'); an outlet abutment configuration (800) configured to direct material to the outlet duct configuration; an outlet valve assembly from the material transporting system venting the material transporting system; and a moving wall configuration in the material transporting apparatus capable of assisting the material transporting apparatus in transporting material in the material transporting system. Material can be moved from the material transporting apparatus hopper structure to the outlet duct configuration through the at least one rotary transporting apparatus, the outlet abutment configuration, and the outlet valve assembly.

  20. Metallurgy, thermal stability, and failure mode of the commercial Bi-Te-based thermoelectric modules.

    SciTech Connect (OSTI)

    Yang, Nancy Y. C.; Morales, Alfredo Martin

    2009-02-01T23:59:59.000Z

    Bi-Te-based thermoelectric (TE) alloys are excellent candidates for power generation modules. We are interested in reliable TE modules for long-term use at or below 200 C. It is known that the metallurgical characteristics of TE materials and of interconnect components affect the performance of TE modules. Thus, we have conducted an extensive scientific investigation of several commercial TE modules to determine whether they meet our technical requirements. Our main focus is on the metallurgy and thermal stability of (Bi,Sb){sup 2}(Te,Se){sup 3} TE compounds and of other materials used in TE modules in the temperature range between 25 C and 200 C. Our study confirms the material suite used in the construction of TE modules. The module consists of three major components: AlN cover plates; electrical interconnects; and the TE legs, P-doped (Bi{sub 8}Sb{sub 32})(Te{sub 60}) and N-doped (Bi{sub 37}Sb{sub 3})(Te{sub 56}Se{sub 4}). The interconnect assembly contains Sn (Sb {approx} 1wt%) solder, sandwiched between Cu conductor with Ni diffusion barriers on the outside. Potential failure modes of the TE modules in this temperature range were discovered and analyzed. The results show that the metallurgical characteristics of the alloys used in the P and N legs are stable up to 200 C. However, whole TE modules are thermally unstable at temperatures above 160 C, lower than the nominal melting point of the solder suggested by the manufacture. Two failure modes were observed when they were heated above 160 C: solder melting and flowing out of the interconnect assembly; and solder reacting with the TE leg, causing dimensional swelling of the TE legs. The reaction of the solder with the TE leg occurs as the lack of a nickel diffusion barrier on the side of the TE leg where the displaced solder and/or the preexisting solder beads is directly contact the TE material. This study concludes that the present TE modules are not suitable for long-term use at temperatures above 160 C due to the reactivity between the Sn-solder and the (Bi,Sb){sup 2}(Te,Se){sup 3} TE alloys. In order to deploy a reliable TE power generator for use at or below 200 C, alternate interconnect materials must be used and/or a modified module fabrication technique must be developed.

  1. Materials Science & Engineering

    E-Print Network [OSTI]

    Reisslein, Martin

    Materials Science & Engineering The development of new high-performance materials for energy Research in Niskayuna, NY. He received his BS and PhD in Materials Science and Engineering at MIT. For 22 and composition of materials at higher spatial resolution, with greater efficiency, and on real materials

  2. Correlation of Local Failure With Measures of Dose Insufficiency in the High-Dose Single-Fraction Treatment of Bony Metastases

    SciTech Connect (OSTI)

    Lovelock, D. Michael, E-mail: lovelocm@mskcc.or [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Zhang Zhigang [Department of Epidemiology-Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Jackson, Andrew [Department of Medical Physics, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Keam, Jennifer [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Bekelman, Justin [Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA (United States); Bilsky, Mark [Department of Neurosurgery, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Lis, Eric [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States); Yamada, Yoshiya [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, NY (United States)

    2010-07-15T23:59:59.000Z

    Purpose: In the setting of high-dose single-fraction image-guided radiotherapy of spine metastases, the delivered dose is hypothesized to be a significant factor in local control. We investigated the dependence of local control on measures of dose insufficiency. Methods and Materials: The minimum doses received by the hottest 100%, 98%, and 95% (D{sub min}, D{sub 98}, and D{sub 95}) of the gross target volume (GTV) were computed for 91 consecutively treated lesions observed in 79 patients. Prescribed doses of 18-24 Gy were delivered in a single fraction. The spinal cord and cauda equina were constrained to a maximum dose of 12-14 Gy and 16 Gy, respectively. A rank-sum test was used to assess the differences between radiographic local failure and local control. Results: With a median follow-up of 18 months, seven local failures have occurred. The distributions of GTV D{sub min}, D{sub 98}, and D{sub 95} for treatments resulting in local failure were found to be statistically different from the corresponding distributions of the patient group as a whole. Taking no account of histology, p values calculated for D{sub min}, D{sub 98}, and D{sub 95} were 0.004, 0.012, and 0.031, respectively. No correlations between local failure and target volume or between local failure and anatomic location were found. Conclusions: The results indicate that D{sub min}, D{sub 98}, and D{sub 95} may be important risk factors for local failure. No local failures in any histology were observed when D{sub min} was >15 Gy, suggesting that this metric may be an important predictor of local control.

  3. Micromechanical simulation of the failure of ber reinforced composites

    E-Print Network [OSTI]

    Micromechanical simulation of the failure of ®ber reinforced composites Chad M. Landisa, *, Irene J Abstract The strength of unidirectionally reinforced ®ber composites is simulated using the three lag model for broken ®bers in composites. J. Comp. Mat. 33, 667±680) and Weibull ®ber statistics

  4. Predicting Electricity Distribution Feeder Failures Using Machine Learning Susceptibility Analysis

    E-Print Network [OSTI]

    Tomkins, Andrew

    ) from the generating station to substations closer to the customers 3.Primary Distribution: electricity into the city from upstate New York, New Jersey and Long Island, as well as from in-city generation facilitiesPredicting Electricity Distribution Feeder Failures Using Machine Learning Susceptibility Analysis

  5. Abduction with Negation as Failure for Active Databases and Agents

    E-Print Network [OSTI]

    Toni, Francesca

    Abduction with Negation as Failure for Active Databases and Agents Fariba Sadri and Francesca Toni suggested abductive logic programming as a suitable formalism to represent active databases and intelligent agents. In particular, abducibles and integrity constaints in abductive logic pro- grams can be used

  6. Abduction with Negation as Failure for Active and Reactive Rules

    E-Print Network [OSTI]

    Toni, Francesca

    Abduction with Negation as Failure for Active and Reactive Rules Fariba Sadri and Francesca Toni suggested abductive logic programming as a suitable formalism to represent active databases and intelligent agents. In particular, abducibles in abductive logic programs can be used to repre- sent actions

  7. Formal Verification of Unreliable Failure Detectors in Partially Synchronous Systems

    E-Print Network [OSTI]

    Mousavi, Mohammad

    Formal Verification of Unreliable Failure Detectors in Partially Synchronous Systems M. Atif TU/Eindhoven Dept. of Computer Science P.O. Box 513, 5600 MB Eindhoven, The Netherlands m.atif@tue.nl M.R. Mousavi TU/Eindhoven Dept. of Computer Science P.O. Box 513, 5600 MB Eindhoven, The Netherlands m

  8. Joint Traffic Blocking and Routing under Network Failures and Maintenances

    E-Print Network [OSTI]

    Liu, Yong

    Joint Traffic Blocking and Routing under Network Failures and Maintenances Chao Liang ECE Dept paths. Therefore, it is important to design ingress traffic blocking and routing jointly to achieve a good balance between the two factors. Working towards this goal, we formulate a joint ingress blocking

  9. Energy-Efficient Neuronal Computation via Quantal Synaptic Failures

    E-Print Network [OSTI]

    Levy, William B.

    Energy-Efficient Neuronal Computation via Quantal Synaptic Failures William B Levy1 and Robert A, and many of these com- promises can be expressed in terms of energy efficiency. For example, a compromise; efficiency; energy; entropy; infor- mation theory; mutual information; optimization; quantal fail- ures

  10. COPYRIGHT NOTICE: James Bessen & Michael J. Meurer: Patent Failure

    E-Print Network [OSTI]

    Landweber, Laura

    COPYRIGHT NOTICE: James Bessen & Michael J. Meurer: Patent Failure is published by Princeton is the United States; the property is U.S. Patent No. 4,528,643, granted in 1985; the owner who initiated ure of patent-related institutions and patent law generally to get the details right.This widespread

  11. Fin Failure Compensation for an Unmanned Underwater Vehicle \\Lambda

    E-Print Network [OSTI]

    Leonard, Naomi

    Fin Failure Compensation for an Unmanned Underwater Vehicle \\Lambda Albert S.­F. Cheng and Naomi on a torpedo­shaped unmanned underwater vehicle (UUV) and design control laws to compensate for a fin that gets Island, is an unmanned underwater vehicle (UUV) representative of a class of UUV designed to have

  12. Performance of Wireless Sensor Networks Under Random Node Failures

    E-Print Network [OSTI]

    Hagberg, Aric

    Performance of Wireless Sensor Networks Under Random Node Failures Milan Bradonji´c Bell range wireless sensor network applications with sensors distributed in the field using decentralized distribution. RGGs have been a standard tool to model and study wireless ad-hoc and wireless sensor networks [4

  13. A MAINTENANCE MODEL FOR COMPONENTS EXPOSED TO SEVERAL FAILURE MECHANISMS

    E-Print Network [OSTI]

    Langseth, Helge

    . The preventive maintenance (PM) is performed periodically with some fixed period , but PM can also be performed describe the "goodness" of the maintenance crew; their ability to prevent failures by performing thorough is assumed to undergo preventive maintenance (PM), usually at fixed time periods > 0. In addition

  14. Backup strategy for robots' failures in an automotive assembly system

    E-Print Network [OSTI]

    Ben-Gal, Irad E.

    history: Received 23 October 2006 Accepted 16 September 2007 Keywords: Automotive industry Assembly lines in the automotive industry High-volume body-shop systems in the automotive industry often consist of a seriesBackup strategy for robots' failures in an automotive assembly system Tomer Kahan a , Yossi Bukchin

  15. Composting Successes and Failures Extending the Growing Season Workshop

    E-Print Network [OSTI]

    Amin, S. Massoud

    3/18/2014 1 Composting Successes and Failures Extending the Growing Season Workshop LaMoine Nickel University of MN SWROC March 12, 2014 Beginning of compost process 9/6/2013 Finished compost product 11/19/2013 What is Composting Composting is a biological process in which microorganisms convert organic

  16. MEMS Reliability: Infrastructure, Test Structures, Experiments, and Failure Modes

    SciTech Connect (OSTI)

    TANNER,DANELLE M.; SMITH,NORMAN F.; IRWIN,LLOYD W.; EATON,WILLIAM P.; HELGESEN,KAREN SUE; CLEMENT,J. JOSEPH; MILLER,WILLIAM M.; MILLER,SAMUEL L.; DUGGER,MICHAEL T.; WALRAVEN,JEREMY A.; PETERSON,KENNETH A.

    2000-01-01T23:59:59.000Z

    The burgeoning new technology of Micro-Electro-Mechanical Systems (MEMS) shows great promise in the weapons arena. We can now conceive of micro-gyros, micro-surety systems, and micro-navigators that are extremely small and inexpensive. Do we want to use this new technology in critical applications such as nuclear weapons? This question drove us to understand the reliability and failure mechanisms of silicon surface-micromachined MEMS. Development of a testing infrastructure was a crucial step to perform reliability experiments on MEMS devices and will be reported here. In addition, reliability test structures have been designed and characterized. Many experiments were performed to investigate failure modes and specifically those in different environments (humidity, temperature, shock, vibration, and storage). A predictive reliability model for wear of rubbing surfaces in microengines was developed. The root causes of failure for operating and non-operating MEMS are discussed. The major failure mechanism for operating MEMS was wear of the polysilicon rubbing surfaces. Reliability design rules for future MEMS devices are established.

  17. Distributed Average Consensus in Sensor Networks with Random Link Failures

    E-Print Network [OSTI]

    Moura, José

    Distributed Average Consensus in Sensor Networks with Random Link Failures Soummya Kar Department: soummyakgandrew.cmu.edu Abstract We study the impact of the topology of a sensor network on distributed average in terms of a moment of the distribution of the norm of a function of the network graph Laplacian matrix L

  18. LESSONS LEARNED FROM AN IMPOUNDMENT SLOPE FAILURE INVOLVING GEOSYNTHETICS

    E-Print Network [OSTI]

    failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment. KEYWORDS: Geosynthetic clay liners, Interface Shear Strength, Waste containment, Strength, Stability to illustrate the importance of (i) properly storing geosynthetic clay liners (GCLs) to reduce the amount

  19. Coding Hazardous Tree Failures for a Data Management System

    E-Print Network [OSTI]

    Standiford, Richard B.

    management; computer programs; coding. The Author Lee A. Paine is a forest pathologist, stationed in Berkeley in the manual on the indicated pages. Page 7, just above H. Property or Person Directly Affected, insert: CityCoding Hazardous Tree Failures for a Data Management System Lee A. Paine PACIFIC SOUTHWEST

  20. Failure Modes and Effects Analysis -LRRR PAGE ~1 Ofll 8

    E-Print Network [OSTI]

    Rathbun, Julie A.

    Analysis (FMEA) is to discover critical failure areas in a system and to remove susceptibility. This memo contains the results of a preliminary FMEA for the LRRR experiment. This analysis will be revised deployed on the moon as a part of the Apollo 11 mission, this FMEA will not dwell on the aspects

  1. Developing an Innovative Field Expedient Fracture Toughness Testing Protocol for Concrete Materials

    SciTech Connect (OSTI)

    Wang, Jy-An John [ORNL; Liu, Ken C [ORNL; Naus, Dan J [ORNL

    2008-09-01T23:59:59.000Z

    The Spiral Notch Torsion Fracture Toughness Test (SNTT) was developed recently to determine the intrinsic fracture toughness (KIC) of structural materials. The SNTT system operates by applying pure torsion to uniform cylindrical specimens with a notch line that spirals around the specimen at a 45? pitch. KIC values are obtained with the aid of a three-dimensional finite-element computer code, TOR3D-KIC. The SNTT method is uniquely suitable for testing a wide variety of materials used extensively in pressure vessel and piping structural components and weldments. Application of the method to metallic, ceramic, and graphite materials has been demonstrated. One important characteristic of SNTT is that neither a fatigue precrack or a deep notch are required for the evaluation of brittle materials, which significantly reduces the sample size requirement. In this paper we report results for a Portland cement-based mortar to demonstrate applicability of the SNTT method to cementitious materials. The estimated KIC of the tested mortar samples with compressive strength of 34.45 MPa was found to be 0.19 MPa m.

  2. Department of Materials Science &

    E-Print Network [OSTI]

    Acton, Scott

    Developing Leaders of Innovation Department of Materials Science & Engineering #12;At the University of Virginia, students in materials science, engineering physics and engineering science choose to tackle compelling issues in materials science and engineering or engineering science

  3. Nanostructured magnetic materials

    E-Print Network [OSTI]

    Chan, Keith T.

    2011-01-01T23:59:59.000Z

    Magnetism and Magnetic Materials Conference, Atlanta, GA (Nanostructured Magnetic Materials by Keith T. Chan Doctor ofinduced by a Si-based material occurs at a Si/Ni interface

  4. Failure as a Service (FaaS): A Cloud Service for Large-Scale, Online Failure Drills

    E-Print Network [OSTI]

    California at Irvine, University of

    . Gunawi Thanh Do Joseph M. Hellerstein Ion Stoica Dhruba Borthakur Jesse Robbins Electrical Engineering of Wisconsin, Madison Facebook Opscode Abstract Cloud computing is pervasive, but cloud service outages still." One main reason why ma- jor outages still occur is that there are many un- known large-scale failure

  5. MATERIALS TRANSFER AGREEMENT

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

    MTAXX-XXX 1 MATERIAL TRANSFER AGREEMENT for Manufacturing Demonstration Facility and Carbon Fiber Technology Facility In order for the RECIPIENT to obtain materials, the RECIPIENT...

  6. Materials at the Mesoscale

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

    Materials at the Mesoscale 1663 Los Alamos science and technology magazine Latest Issue:January 2015 All Issues submit Materials at the Mesoscale Los Alamos's bold proposal to...

  7. UNCLASSIFIED Institute for Materials ...

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

    Institute for Materials Science Lecture Series Dr Roger D Doherty M.A. D. Phil., Fellow TMS Emeritus Professor of Materials Science and Engineering, Drexel University,...

  8. Transporting Hazardous Materials

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

    Transporting Hazardous Materials The procedures given below apply to all materials that are considered to be hazardous by the U.S. Department of Transportation (DOT). Consult your...

  9. battery materials | EMSL

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

    battery materials battery materials Leads No leads are available at this time. Modeling Interfacial Glass-Water Reactions: Recent Advances and Current Limitations. Abstract: The...

  10. EMSL - Energy Materials & Processes

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

    energy Energy Materials and Processes focuses on the dynamic transformation mechanisms and physical and chemical properties at critical interfaces in catalysts and energy materials...

  11. Propulsion Materials Research Update

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    * Materials for Electric and Hybrid Drive Systems - Address materials issues impacting power electronics, motors, and other hybrid drive system components * Combustion System...

  12. Materials Technical Team Roadmap

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    of these as mixed- material systems. Additionally, materials such as titanium, polycarbonate, acrylics, and metal matrix composites, and approaches to their use must be...

  13. Effects of Fusion Zone Size and Failure Mode on Peak Load and Energy Absorption of Advanced High Strength Steel Spot Welds

    SciTech Connect (OSTI)

    Sun, Xin; Stephens, Elizabeth V.; Khaleel, Mohammad A.

    2007-01-01T23:59:59.000Z

    This paper examines the effects of fusion zone size on failure modes, static strength and energy absorption of resistance spot welds (RSW) of advanced high strength steels (AHSS). DP800 and TRIP800 spot welds are considered. The main failure modes for spot welds are nugget pullout and interfacial fracture. Partial interfacial fracture is also observed. The critical fusion zone sizes to ensure nugget pull-out failure mode are developed for both DP800 and TRIP800 using limit load based analytical model and micro-hardness measurements of the weld cross sections. Static weld strength tests using cross tension samples were performed on the joint populations with controlled fusion zone sizes. The resulted peak load and energy absorption levels associated with each failure mode were studied for all the weld populations using statistical data analysis tools. The results in this study show that AHSS spot welds with fusion zone size of can not produce nugget pullout mode for both the DP800 and TRIP800 materials examined. The critical fusion zone size for nugget pullout shall be derived for individual materials based on different base metal properties as well as different heat affected zone (HAZ) and weld properties resulted from different welding parameters.

  14. Nuclear Materials: Reconsidering Wastes and Assets - 13193

    SciTech Connect (OSTI)

    Michalske, T.A. [Savannah River National Laboratory (United States)] [Savannah River National Laboratory (United States)

    2013-07-01T23:59:59.000Z

    The nuclear industry, both in the commercial and the government sectors, has generated large quantities of material that span the spectrum of usefulness, from highly valuable ('assets') to worthless ('wastes'). In many cases, the decision parameters are clear. Transuranic waste and high level waste, for example, have no value, and is either in a final disposition path today, or - in the case of high level waste - awaiting a policy decision about final disposition. Other materials, though discardable, have intrinsic scientific or market value that may be hidden by the complexity, hazard, or cost of recovery. An informed decision process should acknowledge the asset value, or lack of value, of the complete inventory of materials, and the structure necessary to implement the range of possible options. It is important that informed decisions are made about the asset value for the variety of nuclear materials available. For example, there is a significant quantity of spent fuel available for recycle (an estimated $4 billion value in the Savannah River Site's (SRS) L area alone); in fact, SRS has already blended down more than 300 metric tons of uranium for commercial reactor use. Over 34 metric tons of surplus plutonium is also on a path to be used as commercial fuel. There are other radiological materials that are routinely handled at the site in large quantities that should be viewed as strategically important and / or commercially viable. In some cases, these materials are irreplaceable domestically, and failure to consider their recovery could jeopardize our technological leadership or national defense. The inventories of nuclear materials at SRS that have been characterized as 'waste' include isotopes of plutonium, uranium, americium, and helium. Although planning has been performed to establish the technical and regulatory bases for their discard and disposal, recovery of these materials is both economically attractive and in the national interest. (authors)

  15. Delamination Failures in Long-Term Field Aged PV Modules from...

    Office of Environmental Management (EM)

    Delamination Failures in Long-Term Field Aged PV Modules from Point of View of Encapsulant Delamination Failures in Long-Term Field Aged PV Modules from Point of View of...

  16. Failure of man-made cavities in salt and surface subsidence due to sulfur mining

    SciTech Connect (OSTI)

    Coates, G.K.; Lee, C.A.; McClain, W.C.; Senseny, P.E.

    1981-01-01T23:59:59.000Z

    An engineering data base relevant to subsidence due to sulfur mining and to structural failure of cavities in salt is established, evaluated and documented. Nineteen failure events are discussed. Based on these documented failure events, capabilities of and inputs to a mathematical model of cavity failure are determined. Two failure events are adequately documented for use in model verification studies. A conclusion of this study that is pertinent to the Strategic Petroleum Reserve is that cavity failures in dome salt are fairly rare, but that as the number of large cavities (especially those having large roof spans) increases, failures will probably be more common unless stability and failure mechanisms of cavities are better understood.

  17. Failure record discounting in Bayesian analysis in Probabilistic Risk Assessment (PRA) : a space system application

    E-Print Network [OSTI]

    Lekkakos, Spyridon-Damianos

    2006-01-01T23:59:59.000Z

    In estimating a system-specific binomial probability of failure on demand in Probabilistic Risk Assessment (PRA), the corresponding number of observed failures may be not directly applicable due to design or procedure ...

  18. New Functional Imaging Technology to Differentiate between Chronic Obstructive Pulmonary Disease and Heart Failure

    E-Print Network [OSTI]

    Pollack, Charles V.; Slattery, David E

    2011-01-01T23:59:59.000Z

    improvement of congestive heart failure: a pilot study. BMCtesting and the accuracy of heart failure diagnosis in theemergency department. Circ Heart Fail. 2010 Jan;3(1):104-10.

  19. Relaxin: Review of Biology and Potential Role in Treating Heart Failure

    E-Print Network [OSTI]

    Teichman, Sam L.; Unemori, Elaine; Teerlink, John R.; Cotter, Gad; Metra, Marco

    2010-01-01T23:59:59.000Z

    Curr Heart Fail Rep (2010) 7:75–82 DOI 10.1007/s11897-010-Potential Role in Treating Heart Failure Sam L. Teichman &of patients with acute heart failure. Preliminary results

  20. A Path Planning Strategy for Kinematically Redundant Manipulators Anticipating Joint Failures in the Presence of Obstacles

    E-Print Network [OSTI]

    Maciejewski, Anthony A.

    's reliability. However, robot failures are not uncommon. It has been estimated that 28.7% of industrial robots that over 60% of industrial robots had a mean-time-between-failure of less than 500 hours [7]. A number

  1. Corporate bankruptcy : assessment, analysis and prediction of financial distress, insolvency, and failure

    E-Print Network [OSTI]

    Danilov, Konstantin A

    2014-01-01T23:59:59.000Z

    This paper is divided into three sections that address the various elements of understanding, predicting and analyzing corporate failure and bankruptcy. Part I covers the definitions of corporate failure, explains the ...

  2. Statistical Analysis of LifeData with Masked CauseofFailure

    E-Print Network [OSTI]

    Basu, Sanjib

    , a detailed Failure Mode Effect Analysis (FMEA) can be carried out in a routine manner. In reliability been pursued under the general heading of Failure Mode Effect Analysis (FMEA) when the exact causes

  3. Materials Science & Engineering

    E-Print Network [OSTI]

    Materials Science & Engineering In this presentation the role of materials in power generation and the person responsible for the integration of science and resources in the Materials Science & Technology University in Mexico City and a Ph.D. in Materials Engineering from Rensselaer Polytechnic Institute, Troy NY

  4. Coated ceramic breeder materials

    DOE Patents [OSTI]

    Tam, Shiu-Wing (Downers Grove, IL); Johnson, Carl E. (Elk Grove, IL)

    1987-01-01T23:59:59.000Z

    A breeder material for use in a breeder blanket of a nuclear reactor is disclosed. The breeder material comprises a core material of lithium containing ceramic particles which has been coated with a neutron multiplier such as Be or BeO, which coating has a higher thermal conductivity than the core material.

  5. HAZARDOUS MATERIALS EMERGENCY RESPONSE

    E-Print Network [OSTI]

    ANNEX Q HAZARDOUS MATERIALS EMERGENCY RESPONSE #12;ANNEX Q - HAZARDOUS MATERIALS EMERGENCY RESPONSE 03/10/2014 v.2.0 Page Q-1 PROMULGATION STATEMENT Annex Q: Hazardous Materials Emergency Response, and contents within, is a guide to how the University conducts a response specific to a hazardous materials

  6. UNDERGRADUATE Materials Science & Engineering

    E-Print Network [OSTI]

    Tipple, Brett

    UNDERGRADUATE HANDBOOK Materials Science & Engineering 2013 2014 #12;STUDYING FOR A MATERIALS SCIENCE AND ENGINEERING DEGREE Materials Science and Engineering inter-twines numerous disciplines that still gives the students the opportunity to study science while earning an engineering degree. Materials

  7. Materials Science & Engineering

    E-Print Network [OSTI]

    Simons, Jack

    Materials Science & Engineering The University of Utah 2014-15 Undergraduate Handbook #12;STUDYING FOR A MATERIALS SCIENCE AND ENGINEERING DEGREE Materials Science and Engineering inter-twines numerous disciplines that still gives the students the opportunity to study science while earning an engineering degree. Materials

  8. A Materials Facilities Initiative -

    E-Print Network [OSTI]

    A Materials Facilities Initiative - FMITS & MPEX D.L. Hillis and ORNL Team Fusion & Materials for Nuclear Systems Division July 10, 2014 #12;2 Materials Facilities Initiative JET ITER FNSF Fusion Reactor Challenges for materials: fluxes and fluence, temperatures 50 x divertor ion fluxes up to 100 x neutron

  9. University Materials Institute INTRODUCTION

    E-Print Network [OSTI]

    Escolano, Francisco

    University Materials Institute INTRODUCTION The University Materials Science Institute of Alicante the needed multidisciplinary character of the materials area. It is important to highlight the fact participate in the Materials Science PhD program which is imparted at the UA. Scientific research

  10. Dental Materials BIOMATERIALS

    E-Print Network [OSTI]

    Dental Materials BIOMATERIALS Our goal is to provide reference materials and clinically relevant measurement methods to facilitate a rational approach to dental materials design, thus enabling improvements in the clinical performance of dental materials. In particular, methods for determining long-term performance

  11. CRAD, Packaging and Transfer of Hazardous Materials and Materials...

    Office of Environmental Management (EM)

    CRAD, Packaging and Transfer of Hazardous Materials and Materials of National Security Interest Assessment Plan CRAD, Packaging and Transfer of Hazardous Materials and Materials of...

  12. A network approach for power grid robustness against cascading failures

    E-Print Network [OSTI]

    Wang, Xiangrong; Kooij, Robert E; Van Mieghem, Piet

    2015-01-01T23:59:59.000Z

    Cascading failures are one of the main reasons for blackouts in electrical power grids. Stable power supply requires a robust design of the power grid topology. Currently, the impact of the grid structure on the grid robustness is mainly assessed by purely topological metrics, that fail to capture the fundamental properties of the electrical power grids such as power flow allocation according to Kirchhoff's laws. This paper deploys the effective graph resistance as a metric to relate the topology of a grid to its robustness against cascading failures. Specifically, the effective graph resistance is deployed as a metric for network expansions (by means of transmission line additions) of an existing power grid. Four strategies based on network properties are investigated to optimize the effective graph resistance, accordingly to improve the robustness, of a given power grid at a low computational complexity. Experimental results suggest the existence of Braess's paradox in power grids: bringing an additional li...

  13. Dynamic Modeling of Cascading Failure in Power Systems

    E-Print Network [OSTI]

    Song, Jiajia; Ghanavati, Goodarz; Hines, Paul D H

    2014-01-01T23:59:59.000Z

    The modeling of cascading failure in power systems is difficult because of the many different mechanisms involved; no single model captures all of these mechanisms. Understanding the relative importance of these different mechanisms is an important step in choosing which mechanisms need to be modeled for particular types of cascading failure analysis. This work presents a dynamic simulation model of both power networks and protection systems, which can simulate a wider variety of cascading outage mechanisms, relative to existing quasi-steady state (QSS) models. The model allows one to test the impact of different load models and protections on cascading outage sizes. This paper describes each module of the developed dynamic model and demonstrates how different mechanisms interact. In order to test the model we simulated a batch of randomly selected $N-2$ contingencies for several different static load configurations, and found that the distribution of blackout sizes and event lengths from the proposed dynamic...

  14. Failure Rate Data Analysis for High Technology Components

    SciTech Connect (OSTI)

    L. C. Cadwallader

    2007-07-01T23:59:59.000Z

    Understanding component reliability helps designers create more robust future designs and supports efficient and cost-effective operations of existing machines. The accelerator community can leverage the commonality of its high-vacuum and high-power systems with those of the magnetic fusion community to gain access to a larger database of reliability data. Reliability studies performed under the auspices of the International Energy Agency are the result of an international working group, which has generated a component failure rate database for fusion experiment components. The initial database work harvested published data and now analyzes operating experience data. This paper discusses the usefulness of reliability data, describes the failure rate data collection and analysis effort, discusses reliability for components with scarce data, and points out some of the intersections between magnetic fusion experiments and accelerators.

  15. Degradation and failure characteristics of NPP containment protective coating systems

    SciTech Connect (OSTI)

    Sindelar, R.L.

    2000-03-30T23:59:59.000Z

    A research program to investigate the performance and potential for failure of Service Level 1 coating systems used in nuclear power plant containment is in progress. The research activities are aligned to address phenomena important to cause failure as identified by the industry coatings expert panel. The period of interest for performance covers the time from application of the coating through 40 years of service, followed by a medium-to-large break loss-of-coolant accident scenario, which is a design basis accident (DBA) scenario. The interactive program elements are discussed in this report and the application of these elements to the System 5 coating system (polyamide epoxy primer, carbon steel substrate) is used to evaluate performance.

  16. Bayesian failure probability model sensitivity study. Final report

    SciTech Connect (OSTI)

    Not Available

    1986-05-30T23:59:59.000Z

    The Office of the Manager, National Communications System (OMNCS) has developed a system-level approach for estimating the effects of High-Altitude Electromagnetic Pulse (HEMP) on the connectivity of telecommunications networks. This approach incorporates a Bayesian statistical model which estimates the HEMP-induced failure probabilities of telecommunications switches and transmission facilities. The purpose of this analysis is to address the sensitivity of the Bayesian model. This is done by systematically varying two model input parameters--the number of observations, and the equipment failure rates. Throughout the study, a non-informative prior distribution is used. The sensitivity of the Bayesian model to the noninformative prior distribution is investigated from a theoretical mathematical perspective.

  17. Accelerated Testing and On-Sun Failure of CPV Die-Attach (Presentation)

    SciTech Connect (OSTI)

    Bosco, N.; Kurtz, S.; Stokes, A.

    2010-10-01T23:59:59.000Z

    Accelerated Testing and On-Sun Failure of CPV Die-attach. Presentation on CPV accelerated reliability testing.

  18. Patient-specific modeling of cardiac electromechanics in dyssynchronous heart failure

    E-Print Network [OSTI]

    Shin, Jun Seob

    2009-01-01T23:59:59.000Z

    1.3 Congestive Heart1.1: Longitudinal cross-section of the heart . . . . . . .Classification of heart failure . . . . . . . . . . . .

  19. Defining Human Failure Events for Petroleum Risk Analysis

    SciTech Connect (OSTI)

    Ronald L. Boring; Knut Øien

    2014-06-01T23:59:59.000Z

    In this paper, an identification and description of barriers and human failure events (HFEs) for human reliability analysis (HRA) is performed. The barriers, called target systems, are identified from risk significant accident scenarios represented as defined situations of hazard and accident (DSHAs). This report serves as the foundation for further work to develop petroleum HFEs compatible with the SPAR-H method and intended for reuse in future HRAs.

  20. Patterns of Failure After Concurrent Bevacizumab and Hypofractionated Stereotactic Radiation Therapy for Recurrent High-Grade Glioma

    SciTech Connect (OSTI)

    Shapiro, Lauren Q. [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Beal, Kathryn, E-mail: bealk@mskcc.org [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Goenka, Anuj [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Karimi, Sasan [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Iwamoto, Fabio M. [Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Yamada, Yoshiya [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Radiation Oncology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Zhang, Zhigang [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Epidemiology and Biostatistics, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Lassman, Andrew B.; Abrey, Lauren E. [Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Neurology, Memorial Sloan-Kettering Cancer Center, New York, New York (United States); Gutin, Philip H. [Department of Neurosurgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)] [Department of Neurosurgery, Memorial Sloan-Kettering Cancer Center, New York, New York (United States)

    2013-03-01T23:59:59.000Z

    Purpose: Concurrent bevacizumab with hypofractionated stereotactic radiation therapy (HSRT) is safe and effective for the treatment of recurrent high-grade gliomas (HGG). The objective of this study was to characterize the patterns of failure after this treatment regimen. Methods and Materials: Twenty-four patients with recurrent enhancing HGG were previously treated on an institutional review board-approved protocol of concurrent bevacizumab and reirradiation. Patients received 30 Gy in 5 fractions to the recurrent tumor with HSRT. Brain magnetic resonance imaging (MRI) was performed every 2 cycles, and bevacizumab was continued until clinical or radiographic tumor progression according to the criteria of Macdonald et al. MRI at the time of progression was fused to the HSRT treatment plan, and the location of recurrence was classified on the basis of volume within the 95% isodose line. Outcomes based on patient characteristics, tumor grade, recurrence pattern, and best response to treatment were analyzed by the Kaplan-Meier method. Results: Twenty-two patients experienced either clinical or radiographic progression. Recurrent tumor was enhancing in 15 (71.4%) and nonenhancing in 6 (28.6%) patients. Eleven patients (52.4%) had recurrence within the radiation field, 5 patients (23.8%) had marginal recurrence, and 5 patients had recurrence outside the radiation field. Pattern of enhancement and location of failure did not correlate with overall survival or progression-free survival. Radiographic response was the only variable to significantly correlate with progression-free survival. Conclusions: Despite the promising initial response seen with the addition of HSRT to bevacizumab as salvage treatment for recurrent HGG, approximately half of patients ultimately still experience failure within the radiation field. The rate of local failure with the addition of HSRT seems to be lower than that seen with bevacizumab alone in the salvage setting. Our data underscore the radioresistance of HGG and the need for better salvage treatments.

  1. Puncture detecting barrier materials

    DOE Patents [OSTI]

    Hermes, Robert E. (Los Alamos, NM); Ramsey, David R. (Bothel, WA); Stampfer, Joseph F. (Santa Fe, NM); Macdonald, John M. (Santa Fe, NM)

    1998-01-01T23:59:59.000Z

    A method and apparatus for continuous real-time monitoring of the integrity of protective barrier materials, particularly protective barriers against toxic, radioactive and biologically hazardous materials has been developed. Conductivity, resistivity or capacitance between conductive layers in the multilayer protective materials is measured by using leads connected to electrically conductive layers in the protective barrier material. The measured conductivity, resistivity or capacitance significantly changes upon a physical breach of the protective barrier material.

  2. Evaluations of Structural Failure Probabilities and Candidate Inservice Inspection Programs

    SciTech Connect (OSTI)

    Khaleel, Mohammad A.; Simonen, Fredric A.

    2009-05-01T23:59:59.000Z

    The work described in this report applies probabilistic structural mechanics models to predict the reliability of nuclear pressure boundary components. These same models are then applied to evaluate the effectiveness of alternative programs for inservice inspection to reduce these failure probabilities. Results of the calculations support the development and implementation of risk-informed inservice inspection of piping and vessels. Studies have specifically addressed the potential benefits of ultrasonic inspections to reduce failure probabilities associated with fatigue crack growth and stress-corrosion cracking. Parametric calculations were performed with the computer code pc-PRAISE to generate an extensive set of plots to cover a wide range of pipe wall thicknesses, cyclic operating stresses, and inspection strategies. The studies have also addressed critical inputs to fracture mechanics calculations such as the parameters that characterize the number and sizes of fabrication flaws in piping welds. Other calculations quantify uncertainties associated with the inputs calculations, the uncertainties in the fracture mechanics models, and the uncertainties in the resulting calculated failure probabilities. A final set of calculations address the effects of flaw sizing errors on the effectiveness of inservice inspection programs.

  3. Supporting Online Material Materials and Methods

    E-Print Network [OSTI]

    Wolfe, Cecily J.

    1 Supporting Online Material Materials and Methods (15) For all possible earthquake pairs. The parameters chosen for window length, filter bandpass, negative sidelobe identification, and cross-correlation threshold are appropriate for high-frequency earthquakes. In order to remove false positives or poor data

  4. SUPPORTING ONLINE MATERIAL Materials and Methods

    E-Print Network [OSTI]

    Newsome, William

    SUPPORTING ONLINE MATERIAL Materials and Methods Two adult male rhesus monkeys (Macaca mulatta with a head-holding device (S1), scleral search coil for monitoring eye position (S2) and a recording chamber monkeys remain actively engaged in experiments, so precise histological identification of recording sites

  5. Identifying the Failure-Tolerant Workspace Boundaries of a Kinematically Redundant Manipulator

    E-Print Network [OSTI]

    Maciejewski, Anthony A.

    }@colostate.edu) tolerance of a manipulator operating in an m-dimensional workspace, m + 2 joints are required if the joint tolerant to locked-joint failures than non- redundant manipulators. However, a joint failure can still task completion is guaranteed in the event of a locked-joint failure. The existence of such a region

  6. Failure-Tolerant Path Planning for the PA-10 Robot Operating Amongst Obstacles

    E-Print Network [OSTI]

    Maciejewski, Anthony A.

    Failure-Tolerant Path Planning for the PA-10 Robot Operating Amongst Obstacles Rodrigo S. Jamisola/or orientation in the workspace despite any single locked-joint failure at any time. An algorithm is presented relative to its task, only a single locked-joint failure occurs at any given time, the robot is capable

  7. Efficient Failure Detection for Mobile Robots Using Mixed-Abstraction Particle Filters

    E-Print Network [OSTI]

    Stachniss, Cyrill

    Efficient Failure Detection for Mobile Robots Using Mixed-Abstraction Particle Filters Christian the problem of online failure detection and isolation for mobile robots. The goal is to enable a mobile robot failures of mobile robots. It uses a hierarchy of process models to actively validate the model assumptions

  8. FailureTolerant Robots for Industrial Applications \\Lambda K. N. Groom, A. A. Maciejewski, V. Balakrishnan

    E-Print Network [OSTI]

    Balakrishnan, Venkataramanan "Ragu"

    Failure­Tolerant Robots for Industrial Applications \\Lambda K. N. Groom, A. A. Maciejewski, V robots vary, depending on the application environment and the quality of maintenance. However, a mean March 1997 Abstract Industrial robot failures occur frequently. The consequences of these failures

  9. Condition Data Aggregation with Application to Failure Rate Calculation of Power Transformers

    E-Print Network [OSTI]

    Condition Data Aggregation with Application to Failure Rate Calculation of Power Transformers for condition monitoring and failure rate prediction of power transformers. Specif- ically, the system uses to the substation, to develop Hidden Markov Models (HMMs) which transform the condition data into failure

  10. Results -Sunny Day Failure Case -4 -3 -2 -1 0 1 2

    E-Print Network [OSTI]

    Bowles, David S.

    Time(hr) %ofPar %Warned %Mobilized %Loss of Life %Warned %Mobilized %Loss of Life Dam failure time Solid Decisiontonotify Detection Failure Notification TimelineforDam Par A1elevation range Decisiontowarn Dam Emergency dam failure or natural floods for use in dam safety risk assessment and emergency planning. Sponsors

  11. Signature of Rhine Valley sturzstrom dam failures in Holocene sediments of Lake Constance, Germany

    E-Print Network [OSTI]

    Gilli, Adrian

    Signature of Rhine Valley sturzstrom dam failures in Holocene sediments of Lake Constance, Germany that the hyperpycnite deposits are directly related to the failure of two sturzstrom dams and the draining of the dammed and Schuster, 1988). Landslide-dammed lake failures constitute a major hazard to downstream areas (Eis- bacher

  12. Dynamic model failure tests of dam structures Dalian University of Technology, Dalian 116024, China

    E-Print Network [OSTI]

    Spencer Jr., B.F.

    Dynamic model failure tests of dam structures Gao Lin Dalian University of Technology, Dalian failure tests of a number of concrete gravity dams, concrete arch dams and embankment dams have been index for the safety assessment of concrete dams and is predicted through dynamic model failure tests

  13. The geomorphic influences of beaver dams and failures of beaver dams

    E-Print Network [OSTI]

    The geomorphic influences of beaver dams and failures of beaver dams David R. Butlera,T, George P millions to low billions of cubic meters range. Failure of beaver dams is a more common phenomenon than often assumed in the literature. During the past 20 years, numerous cases of dam failure have been

  14. Late Pleistocene earthquake-triggered moraine dam failure and outburst of Lake Zurich, Switzerland

    E-Print Network [OSTI]

    Gilli, Adrian

    Late Pleistocene earthquake-triggered moraine dam failure and outburst of Lake Zurich, Switzerland of $20,600 m3 sÀ1 . We also discuss long-term causes and short-term trigger mechanisms of the dam failure of Lake Zurich was initiated as a consequence of the moraine dam failure that either was triggered

  15. University of Virginia School of Medicine Emergency Conditions and Systems Failures FACULTY/STAFF REFERENCE GUIDE

    E-Print Network [OSTI]

    Acton, Scott

    instructions from institutional leaders/police. Report on the incident to responders. Computer or network integrity such as lost data. Electrical power failure (no emergency power) Total failure of all electrical. Electrical power failure (emergency generators work) Many lights out. Only red electrical outlets function

  16. Edinburgh Research Explorer Global association of air pollution and heart failure

    E-Print Network [OSTI]

    Edinburgh, University of

    Edinburgh Research Explorer Global association of air pollution and heart failure Citation & Mills, NL 2013, 'Global association of air pollution and heart failure: a systematic review and meta-6736(13)60898-3 1 Global association of air pollution and heart failure: a systematic review and meta-analysis Anoop

  17. Critical points and transitions in an electric power transmission model for cascading failure blackouts

    E-Print Network [OSTI]

    Dobson, Ian

    Critical points and transitions in an electric power transmission model for cascading failure September 2002 Cascading failures in large-scale electric power transmission systems are an important cause, we examine cascading failure in a simplified transmission system model as load power demand

  18. Decreased T-Cell Responses to Influenza Vaccination in Patients with Heart Failure

    E-Print Network [OSTI]

    Wisconsin at Madison, University of

    Decreased T-Cell Responses to Influenza Vaccination in Patients with Heart Failure Orly Vardeny vaccination in patients with chronic heart failure (CHF) are less vigorous than the responses of healthy strategies for influenza vaccination. Key Words: chronic heart failure, CHF, influenza vaccination, immune

  19. FAILURE DETECTION ROUTINE FOR GRID CONNECTED PV SYSTEMS AS PART OF THE PVSAT-2 PROJECT

    E-Print Network [OSTI]

    Heinemann, Detlev

    Dept. Of Electrical Engineering, University of Applied Science (FH) Magdeburg-Stendal. D-39114 failures, e.g. shading, string or module failure, part time outages, snow cover, soiling and wrong inverter, the maintenance effort of PV systems is reduced und system outage time is minimised. The Failure Detection Routine

  20. Appl Physiol Nutr Metab. Author manuscript Exercise training, energy metabolism, and heart failure

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    , and heart failure Ventura-Clapier Ren eé * Signalisation et physiopathologie cardiaque INSERM : U769, IFR141 in many pathophysiological processes among which heart failure. Because endurance training improves recognized as a beneficial practice for heart failure patients. The mechanisms involved in the beneficial

  1. Soluble Epoxide Hydrolase Inhibitors and Heart Failure Jun-Yan Liu,3

    E-Print Network [OSTI]

    Hammock, Bruce D.

    REVIEW Soluble Epoxide Hydrolase Inhibitors and Heart Failure Hong Qiu,1 Ning Li,1 Jun-Yan Liu,3; Epoxyeicosatrienoic acids (EETs); Heart failure; Soluble epoxide hydrolase inhibitors. Correspondence Nipavan of death in the West- ern societies. Heart failure (HF) is due primarily to progressive myocardial dys

  2. IEEE TRANSACTIONS ON POWER SYSTEMS Stochastic Analysis of Cascading-Failure Dynamics

    E-Print Network [OSTI]

    Hayat, Majeed M.

    IEEE TRANSACTIONS ON POWER SYSTEMS Stochastic Analysis of Cascading-Failure Dynamics in Power Grids of the system. Cas- cading failures in power grids can be described as successive changes of power-grid states system state during cascading failures may not be feasible. This is mainly due the large space of power

  3. Wind Turbine Bearing Failure Detection Using Generator Stator Current Homopolar Component

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Wind Turbine Bearing Failure Detection Using Generator Stator Current Homopolar Component Ensemble Empirical Mode Decomposition (EEMD) as a tool for failure detection in wind turbine generators for stationary and non stationary cases. Index Terms-Wind turbine, induction generator, bearing failure, ensemble

  4. Quantifying uncertainty from material inhomogeneity.

    SciTech Connect (OSTI)

    Battaile, Corbett Chandler; Emery, John M.; Brewer, Luke N.; Boyce, Brad Lee

    2009-09-01T23:59:59.000Z

    Most engineering materials are inherently inhomogeneous in their processing, internal structure, properties, and performance. Their properties are therefore statistical rather than deterministic. These inhomogeneities manifest across multiple length and time scales, leading to variabilities, i.e. statistical distributions, that are necessary to accurately describe each stage in the process-structure-properties hierarchy, and are ultimately the primary source of uncertainty in performance of the material and component. When localized events are responsible for component failure, or when component dimensions are on the order of microstructural features, this uncertainty is particularly important. For ultra-high reliability applications, the uncertainty is compounded by a lack of data describing the extremely rare events. Hands-on testing alone cannot supply sufficient data for this purpose. To date, there is no robust or coherent method to quantify this uncertainty so that it can be used in a predictive manner at the component length scale. The research presented in this report begins to address this lack of capability through a systematic study of the effects of microstructure on the strain concentration at a hole. To achieve the strain concentration, small circular holes (approximately 100 {micro}m in diameter) were machined into brass tensile specimens using a femto-second laser. The brass was annealed at 450 C, 600 C, and 800 C to produce three hole-to-grain size ratios of approximately 7, 1, and 1/7. Electron backscatter diffraction experiments were used to guide the construction of digital microstructures for finite element simulations of uniaxial tension. Digital image correlation experiments were used to qualitatively validate the numerical simulations. The simulations were performed iteratively to generate statistics describing the distribution of plastic strain at the hole in varying microstructural environments. In both the experiments and simulations, the deformation behavior was found to depend strongly on the character of the nearby microstructure.

  5. Congestive heart failure: treat the disease, not the symptom: return to normalcy/Part II--the experimental approach.

    E-Print Network [OSTI]

    Buckberg, Gerald D

    2007-01-01T23:59:59.000Z

    Title: Congestive heart failure: treat the disease not theTITLE: Congestive heart failure: treat the disease not theGD. Congestive heart failure: treat the disease, not the

  6. Application of elastic-plastic fracture mechanics to marine structures 

    E-Print Network [OSTI]

    Pathi, Amarkumar

    1991-01-01T23:59:59.000Z

    , be able to support the loads that are applied during its operating lifetime. The structural integrity of components can be assured by knowledge of the material used in their construction. The fracture behavior of a given structure or material depends... or fatigue cracks. Ship structures operate in or near the ductile-brittle transition region, where the failure mechanism is unstable cleavage. Consequently materials are characterized by a transition temperature region above which they may be safely used...

  7. Causal Inference and Prediction in Health Studies: Environmental Exposures and Schistosomiasis, HIV-1 Genotypic Susceptibility Scores and Virologic Suppression, and Risk of Hospital Readmission for Heart Failure Patients

    E-Print Network [OSTI]

    Sudat, Sylvia

    2012-01-01T23:59:59.000Z

    hospitalization for congestive heart failure among Medicarepredictors of readmission for heart failure: a systematicof hospital readmission for heart failure: development of a

  8. Coupled reservoir-geomechanical analysis of the potential for tensile and shear failure associated with CO2 injection in multilayered reservoir-caprock systems

    E-Print Network [OSTI]

    Rutqvist, J.; Birkholzer, J.T.; Tsang, C.-F.

    2008-01-01T23:59:59.000Z

    geological system. This failure analysis aimed to studyshear and tensile failure analysis is essential for thestress field, and (2) a failure analysis using the stress

  9. Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems (Poster)

    SciTech Connect (OSTI)

    Miller, D. C.; Kempe, M. D.; Araki, K.; Kennedy, C. E.; Kurtz, S. R.

    2011-02-01T23:59:59.000Z

    Polymeric encapsulation materials are typically used in concentrating photovoltaic (CPV) modules to protect the cell from the field environment. Because it is physically located adjacent to the cell, the encapsulation is exposed to a high optical flux, often including light in the ultraviolet (UV) and infrared (IR) wavelengths. The durability of encapsulants used in CPV modules is critical to the technology, but is presently not well understood. This work seeks to identify the appropriate material types, field-induced failure mechanisms, and factors of influence (if possible) of polymeric encapsulation. These results will ultimately be weighed against those of future qualification and accelerated life test procedures.

  10. Durability of Polymeric Encapsulation Materials for Concentrating Photovoltaic Systems (Presentation)

    SciTech Connect (OSTI)

    Miller, D. C.; Muller, M.; Kempe, M. D.; Araki, K.; Kennedy, C. E.; Kurtz, S. R.

    2011-04-01T23:59:59.000Z

    Presented at the 7th International Conference on Concentrating Photovoltaic Systems (CPV-7), 4-6 April 2011, Las Vegas, Nevada. Many concentrating photovoltaic (CPV) systems use a polymeric encapsulant to couple an optical component and/or coverglass to the cell. In that location, the encapsulation improves the transmission of concentrated optical flux through interfaces(s) while protecting the cell from the environment. The durability of encapsulation materials, however, is not well established relative to the desired service life of 30 years. Therefore, we have initiated a screen test to identify the field-induced failure modes for a variety of popular PV encapsulation materials.

  11. Sensors & Materials | Argonne National Laboratory

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

    Sensors and Materials Argonne uses its materials and engineering expertise to develop, test, and deploy sensors and materials to detect nuclear and radiological materials, chemical...

  12. Lightweighting Materials | Clean Energy | ORNL

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

    ORNL conducts lightweight materials research in several areas: materials development, properties and manufacturing, computational materials science, and multi-material enabling...

  13. Joining of dissimilar materials

    DOE Patents [OSTI]

    Tucker, Michael C; Lau, Grace Y; Jacobson, Craig P

    2012-10-16T23:59:59.000Z

    A method of joining dissimilar materials having different ductility, involves two principal steps: Decoration of the more ductile material's surface with particles of a less ductile material to produce a composite; and, sinter-bonding the composite produced to a joining member of a less ductile material. The joining method is suitable for joining dissimilar materials that are chemically inert towards each other (e.g., metal and ceramic), while resulting in a strong bond with a sharp interface between the two materials. The joining materials may differ greatly in form or particle size. The method is applicable to various types of materials including ceramic, metal, glass, glass-ceramic, polymer, cermet, semiconductor, etc., and the materials can be in various geometrical forms, such as powders, fibers, or bulk bodies (foil, wire, plate, etc.). Composites and devices with a decorated/sintered interface are also provided.

  14. Pretreatment Apparent Diffusion Coefficient of the Primary Lesion Correlates With Local Failure in Head-and-Neck Cancer Treated With Chemoradiotherapy or Radiotherapy

    SciTech Connect (OSTI)

    Hatakenaka, Masamitsu, E-mail: mhatake@radiol.med.kyushu-u.ac.jp [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka City (Japan); Nakamura, Katsumasa; Yabuuchi, Hidetake; Shioyama, Yoshiyuki; Matsuo, Yoshio; Ohnishi, Kayoko; Sunami, Shunya; Kamitani, Takeshi; Setoguchi, Taro; Yoshiura, Takashi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka City (Japan); Nakashima, Torahiko [Department of Otorhinolaryngology, Graduate School of Medical Sciences, Kyushu University, Fukuoka City (Japan); Nishikawa, Kei [Radiology Center, Kyushu University Hospital, Kyushu University, Fukuoka City (Japan); Honda, Hiroshi [Department of Clinical Radiology, Graduate School of Medical Sciences, Kyushu University, Fukuoka City (Japan)

    2011-10-01T23:59:59.000Z

    Purpose: This study was performed to evaluate whether the apparent diffusion coefficient (ADC) of a primary lesion correlates with local failure in primary head-and-neck squamous cell carcinoma (HNSCC) treated with chemoradiotherapy or radiotherapy. Methods and Materials: We retrospectively studied 38 patients with primary HNSCC (12 oropharynx, 20 hypopharynx, 4 larynx, 2 oral cavity) treated with chemoradiotherapy or radiotherapy with radiation dose to gross tumor volume equal to or over 60 Gy and who underwent pretreatment magnetic resonance imaging, including diffusion-weighted imaging. Ten patients developed local failure during follow-up periods of 2.0 to 9.3 months, and the remaining 28 showed local control during follow-up periods of 10.5 to 31.7 months. The variables that could affect local failure (age, tumor volume, ADC, T stage, N stage, dose, treatment method, tumor location, and overall treatment time) were analyzed using logistic regression analyses for all 38 patients and for 17 patients with Stage T3 or T4 disease. Results: In univariate logistic analysis for all 38 cases, tumor volume, ADC, T stage, and treatment method showed significant (p < 0.05) associations with local failure. In multivariate analysis, ADC and T stage revealed significance (p < 0.01). In univariate logistic analysis for the 17 patients with Stage T3 or T4 disease, ADC and dose showed significant (p < 0.01) associations with local failure. In multivariate analysis, ADC alone showed significance (p < 0.05). Conclusions: The results suggest that pretreatment ADC, along with T stage, is a potential indicator of local failure in HNSCC treated with chemoradiotherapy or radiotherapy.

  15. Corrosion of barrier materials in seawater environments

    SciTech Connect (OSTI)

    Heiser, J.H.; Soo, P.

    1995-07-01T23:59:59.000Z

    A brief review has been carried out on the performance of barrier materials for low-level radioactive wastes in seawater environments. The environments include those for shallower coastal waters as well as the deep ocean (down to 3800 m). The review is mainly focused on metallic materials since they are the most common for seawater service and they have the largest data base. Information from the literature is usually pertinent to shallower coastal locations, but there is a valuable source of corrosion data obtained from several studies of metallic specimens exposed to ocean-bed conditions. In addition, the corrosion of carbon steel barriers has been evaluated for actual waste containers that were retrieved from previously-used disposal sites in the Atlantic and Pacific Oceans. Of the metallic materials studied, carbon steel showed the least corrosion resistance. Failure by non-uniform attack in a typical waste container could occur in as little as 25 y in some ocean environments ` Penetration by local attack, such as pitting and crevice corrosion resistance was also observed for more expensive materials such as low-alloy steels, stainless steels, titanium alloys, zirconium alloys, copper alloys, nickel alloys, aluminum alloys, and lead alloys.

  16. A stochastic flow rule for granular materials

    E-Print Network [OSTI]

    Ken Kamrin; Martin Z. Bazant

    2006-09-19T23:59:59.000Z

    There have been many attempts to derive continuum models for dense granular flow, but a general theory is still lacking. Here, we start with Mohr-Coulomb plasticity for quasi-2D granular materials to calculate (average) stresses and slip planes, but we propose a "stochastic flow rule" (SFR) to replace the principle of coaxiality in classical plasticity. The SFR takes into account two crucial features of granular materials - discreteness and randomness - via diffusing "spots" of local fluidization, which act as carriers of plasticity. We postulate that spots perform random walks biased along slip-lines with a drift direction determined by the stress imbalance upon a local switch from static to dynamic friction. In the continuum limit (based on a Fokker-Planck equation for the spot concentration), this simple model is able to predict a variety of granular flow profiles in flat-bottom silos, annular Couette cells, flowing heaps, and plate-dragging experiments -- with essentially no fitting parameters -- although it is only expected to function where material is at incipient failure and slip-lines are inadmissible. For special cases of admissible slip-lines, such as plate dragging under a heavy load or flow down an inclined plane, we postulate a transition to rate-dependent Bagnold rheology, where flow occurs by sliding shear planes. With different yield criteria, the SFR provides a general framework for multiscale modeling of plasticity in amorphous materials, cycling between continuum limit-state stress calculations, meso-scale spot random walks, and microscopic particle relaxation.

  17. Materials for breeding blankets

    SciTech Connect (OSTI)

    Mattas, R.F.; Billone, M.C.

    1995-09-01T23:59:59.000Z

    There are several candidate concepts for tritium breeding blankets that make use of a number of special materials. These materials can be classified as Primary Blanket Materials, which have the greatest influence in determining the overall design and performance, and Secondary Blanket Materials, which have key functions in the operation of the blanket but are less important in establishing the overall design and performance. The issues associated with the blanket materials are specified and several examples of materials performance are given. Critical data needs are identified.

  18. Nondestructive material characterization

    DOE Patents [OSTI]

    Deason, Vance A. (Idaho Falls, ID); Johnson, John A. (Idaho Falls, ID); Telschow, Kenneth L. (Idaho Falls, ID)

    1991-01-01T23:59:59.000Z

    A method and apparatus for nondestructive material characterization, such as identification of material flaws or defects, material thickness or uniformity and material properties such as acoustic velocity. The apparatus comprises a pulsed laser used to excite a piezoelectric (PZ) transducer, which sends acoustic waves through an acoustic coupling medium to the test material. The acoustic wave is absorbed and thereafter reflected by the test material, whereupon it impinges on the PZ transducer. The PZ transducer converts the acoustic wave to electrical impulses, which are conveyed to a monitor.

  19. EC Transmission Line Materials

    SciTech Connect (OSTI)

    Bigelow, Tim S [ORNL

    2012-05-01T23:59:59.000Z

    The purpose of this document is to identify materials acceptable for use in the US ITER Project Office (USIPO)-supplied components for the ITER Electron cyclotron Heating and Current Drive (ECH&CD) transmission lines (TL), PBS-52. The source of material property information for design analysis shall be either the applicable structural code or the ITER Material Properties Handbook. In the case of conflict, the ITER Material Properties Handbook shall take precedence. Materials selection, and use, shall follow the guidelines established in the Materials Assessment Report (MAR). Materials exposed to vacuum shall conform to the ITER Vacuum Handbook. [Ref. 2] Commercial materials shall conform to the applicable standard (e.g., ASTM, JIS, DIN) for the definition of their grade, physical, chemical and electrical properties and related testing. All materials for which a suitable certification from the supplier is not available shall be tested to determine the relevant properties, as part of the procurement. A complete traceability of all the materials including welding materials shall be provided. Halogenated materials (example: insulating materials) shall be forbidden in areas served by the detritiation systems. Exceptions must be approved by the Tritium System and Safety Section Responsible Officers.

  20. INTERDISCIPLINARY MATERIALS SCIENCE GRADUATE PROGRAM IN MATERIALS SCIENCE

    E-Print Network [OSTI]

    Simaan, Nabil

    .m.satterwhite@vanderbilt.edu Interdisciplinary Graduate Program in Materials Science Vanderbilt University School of Engineering PMB 350106INTERDISCIPLINARY MATERIALS SCIENCE GRADUATE PROGRAM IN MATERIALS SCIENCE Materials advancements, faculty members from chemistry, physics, materials engineering, chemical engineering, electrical

  1. Composite Materials for Hazard Mitigation of Reactive Metal Hydrides.

    SciTech Connect (OSTI)

    Pratt, Joseph William; Cordaro, Joseph Gabriel; Sartor, George B.; Dedrick, Daniel E.; Reeder, Craig L.

    2012-02-01T23:59:59.000Z

    In an attempt to mitigate the hazards associated with storing large quantities of reactive metal hydrides, polymer composite materials were synthesized and tested under simulated usage and accident conditions. The composites were made by polymerizing vinyl monomers using free-radical polymerization chemistry, in the presence of the metal hydride. Composites with vinyl-containing siloxane oligomers were also polymerized with and without added styrene and divinyl benzene. Hydrogen capacity measurements revealed that addition of the polymer to the metal hydride reduced the inherent hydrogen storage capacity of the material. The composites were found to be initially effective at reducing the amount of heat released during oxidation. However, upon cycling the composites, the mitigating behavior was lost. While the polymer composites we investigated have mitigating potential and are physically robust, they undergo a chemical change upon cycling that makes them subsequently ineffective at mitigating heat release upon oxidation of the metal hydride. Acknowledgements The authors would like to thank the following people who participated in this project: Ned Stetson (U.S. Department of Energy) for sponsorship and support of the project. Ken Stewart (Sandia) for building the flow-through calorimeter and cycling test stations. Isidro Ruvalcaba, Jr. (Sandia) for qualitative experiments on the interaction of sodium alanate with water. Terry Johnson (Sandia) for sharing his expertise and knowledge of metal hydrides, and sodium alanate in particular. Marcina Moreno (Sandia) for programmatic assistance. John Khalil (United Technologies Research Corp) for insight into the hazards of reactive metal hydrides and real-world accident scenario experiments. Summary In an attempt to mitigate and/or manage hazards associated with storing bulk quantities of reactive metal hydrides, polymer composite materials (a mixture of a mitigating polymer and a metal hydride) were synthesized and tested under simulated usage and accident conditions. Mitigating the hazards associated with reactive metal hydrides during an accident while finding a way to keep the original capability of the active material intact during normal use has been the focus of this work. These composites were made by polymerizing vinyl monomers using free-radical polymerization chemistry, in the presence of the metal hydride, in this case a prepared sodium alanate (chosen as a representative reactive metal hydride). It was found that the polymerization of styrene and divinyl benzene could be initiated using AIBN in toluene at 70 degC. The resulting composite materials can be either hard or brittle solids depending on the cross-linking density. Thermal decomposition of these styrene-based composite materials is lower than neat polystyrene indicating that the chemical nature of the polymer is affected by the formation of the composite. The char-forming nature of cross-linked polystyrene is low and therefore, not an ideal polymer for hazard mitigation. To obtain composite materials containing a polymer with higher char-forming potential, siloxane-based monomers were investigated. Four vinyl-containing siloxane oligomers were polymerized with and without added styrene and divinyl benzene. Like the styrene materials, these composite materials exhibited thermal decomposition behavior significantly different than the neat polymers. Specifically, the thermal decomposition temperature was shifted approximately 100 degC lower than the neat polymer signifying a major chemical change to the polymer network. Thermal analysis of the cycled samples was performed on the siloxane-based composite materials. It was found that after 30 cycles the siloxane-containing polymer composite material has similar TGA/DSC-MS traces as the virgin composite material indicating that the polymer is physically intact upon cycling. Hydrogen capacity measurements revealed that addition of the polymer to the metal hydride in the form of a composite material reduced the inherent hydrogen storage capacity of the material. This

  2. Materials and Design 50 (2013) 38-43 Regeneration Technique for Welding Nanostructured Bainite

    E-Print Network [OSTI]

    Cambridge, University of

    2013-01-01T23:59:59.000Z

    by spark wire cutting. Bead-on-plate welds with autogenous gas tungsten arc welding were perform by the heat input during welding, from transforming into brittle martensite. The microstructures of the fusion to the formation of brittle, untempered martensite. Hong et al. [6] attempted a rapid post-weld heat treatment

  3. Materials Science & Engineering

    E-Print Network [OSTI]

    and Forensics team in the Polymers and Coatings Group, MST-7. He graduated from the University of Toledo, aerogels, carbon fiber composites, damaged materials, and low density materials examining defects

  4. Institute for Materials Science

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

    Institute for Material Science Who we are and what we do 2:23 Institute for Materials Science: Alexander V. Balatsky IMS is an interdisciplinary research and educational center...

  5. Electronic digital materials

    E-Print Network [OSTI]

    Langford, William Kai

    2014-01-01T23:59:59.000Z

    Digital materials are constructions assembled from a small number of types of discrete building blocks; they represent a new way of building functional, multi-material, three-dimensional structures. In this thesis, I focus ...

  6. Geopolymer Sealing Materials

    Broader source: Energy.gov [DOE]

    DOE Geothermal Peer Review 2010 - Presentation. Project objectives: Develop and characterize field-applicable geopolymer temporary sealing materials in the laboratory and to transfer this developed material technology to geothermal drilling service companies as collaborators for field validation tests.

  7. Nanocomposites as thermoelectric materials

    E-Print Network [OSTI]

    Hao, Qing

    2010-01-01T23:59:59.000Z

    Thermoelectric materials have attractive applications in electric power generation and solid-state cooling. The performance of a thermoelectric device depends on the dimensionless figure of merit (ZT) of the material, ...

  8. Factors of material consumption

    E-Print Network [OSTI]

    Silva Díaz, Pamela Cristina

    2012-01-01T23:59:59.000Z

    Historic consumption trends for materials have been studied by many researchers, and, in order to identify the main drivers of consumption, special attention has been given to material intensity, which is the consumption ...

  9. Nanostructured composite reinforced material

    DOE Patents [OSTI]

    Seals, Roland D. (Oak Ridge, TN); Ripley, Edward B. (Knoxville, TN); Ludtka, Gerard M. (Oak Ridge, TN)

    2012-07-31T23:59:59.000Z

    A family of materials wherein nanostructures and/or nanotubes are incorporated into a multi-component material arrangement, such as a metallic or ceramic alloy or composite/aggregate, producing a new material or metallic/ceramic alloy. The new material has significantly increased strength, up to several thousands of times normal and perhaps substantially more, as well as significantly decreased weight. The new materials may be manufactured into a component where the nanostructure or nanostructure reinforcement is incorporated into the bulk and/or matrix material, or as a coating where the nanostructure or nanostructure reinforcement is incorporated into the coating or surface of a "normal" substrate material. The nanostructures are incorporated into the material structure either randomly or aligned, within grains, or along or across grain boundaries.

  10. VHTR Materials Overview

    SciTech Connect (OSTI)

    Wright, Richard [Idaho National Lab. (INL), Idaho Falls, ID (United States)

    2013-07-30T23:59:59.000Z

    The PowerPoint presentation was given at the DOE-NE Materials Crosscut Coordination Meeting, Tuesday, 30 July 2013.

  11. Effect of component failures on economics of distributed photovoltaic systems

    SciTech Connect (OSTI)

    Lubin, B

    2012-02-02T23:59:59.000Z

    This report describes an applied research program to assess the realistic costs of grid connected photovoltaic (PV) installations. A Board of Advisors was assembled that included management from the regional electric power utilities, as well as other participants from companies that work in the electric power industry. Although the program started with the intention of addressing effective load carrying capacity (ELCC) for utility-owned photovoltaic installations, results from the literature study and recommendations from the Board of Advisors led investigators to the conclusion that obtaining effective data for this analysis would be difficult, if not impossible. The effort was then re-focused on assessing the realistic costs and economic valuations of grid-connected PV installations. The 17 kW PV installation on the University of Hartford's Lincoln Theater was used as one source of actual data. The change in objective required a more technically oriented group. The re-organized working group (changes made due to the need for more technically oriented participants) made site visits to medium-sized PV installations in Connecticut with the objective of developing sources of operating histories. An extensive literature review helped to focus efforts in several technical and economic subjects. The objective of determining the consequences of component failures on both generation and economic returns required three analyses. The first was a Monte-Carlo-based simulation model for failure occurrences and the resulting downtime. Published failure data, though limited, was used to verify the results. A second model was developed to predict the reduction in or loss of electrical generation related to the downtime due to these failures. Finally, a comprehensive economic analysis, including these failures, was developed to determine realistic net present values of installed PV arrays. Two types of societal benefits were explored, with quantitative valuations developed for both. Some societal benefits associated with financial benefits to the utility of having a distributed generation capacity that is not fossil-fuel based have been included into the economic models. Also included and quantified in the models are several benefits to society more generally: job creation and some estimates of benefits from avoiding greenhouse emissions. PV system failures result in a lowering of the economic values of a grid-connected system, but this turned out to be a surprisingly small effect on the overall economics. The most significant benefit noted resulted from including the societal benefits accrued to the utility. This provided a marked increase in the valuations of the array and made the overall value proposition a financially attractive one, in that net present values exceeded installation costs. These results indicate that the Department of Energy and state regulatory bodies should consider focusing on societal benefits that create economic value for the utility, confirm these quantitative values, and work to have them accepted by the utilities and reflected in the rate structures for power obtained from grid-connected arrays. Understanding and applying the economic benefits evident in this work can significantly improve the business case for grid-connected PV installations. This work also indicates that the societal benefits to the population are real and defensible, but not nearly as easy to justify in a business case as are the benefits that accrue directly to the utility.

  12. Research Councils UK materials

    E-Print Network [OSTI]

    Berzins, M.

    as completely new materials such as super-strong graphene, or developments of traditional materials such as graphene is still being realised, with the Research Councils investing in both the further exploitation to UK growth. For example, the 2004 `discovery' of wonder-material graphene sparked a host of global

  13. MATERIALS SCIENCE ENGINEERING

    E-Print Network [OSTI]

    California at Irvine, University of

    MATERIALS SCIENCE AND ENGINEERING GRADUATE MANUAL COLLEGE OF ENGINEERING UNIVERSITY OF CALIFORNIA AT BERKELEY October 23, 2013 #12;Materials Science and Engineering University of California at Berkeley Page 2 Subject Matter · Outcome of the Preliminary Exam #12;Materials Science and Engineering University

  14. MATERIALS SCIENCE AND ENGINEERING

    E-Print Network [OSTI]

    Knobloch,Jürgen

    MATERIALS SCIENCE AND ENGINEERING BACHELOR OF SCIENCE MASTER OF SCIENCE Get your own impression. Materials Science and Engineering in Ilmenau stands for: + a broad and practical university education Catòlica del Peru (PUCP) in Lima/Peru and to receive a double degree in Materials Science and Engineering

  15. Radioactive Materials License Commitments

    E-Print Network [OSTI]

    Radioactive Materials License Commitments for The University of Texas at Austin May 2009 July 2009 in the use of radioactive materials. In July 1963, the State of Texas granted The University of Texas at Austin a broad radioactive materials license for research, development and instruction. While this means

  16. Advanced neutron absorber materials

    DOE Patents [OSTI]

    Branagan, Daniel J. (Idaho Falls, ID); Smolik, Galen R. (Idaho Falls, ID)

    2000-01-01T23:59:59.000Z

    A neutron absorbing material and method utilizing rare earth elements such as gadolinium, europium and samarium to form metallic glasses and/or noble base nano/microcrystalline materials, the neutron absorbing material having a combination of superior neutron capture cross sections coupled with enhanced resistance to corrosion, oxidation and leaching.

  17. Polymer Filler Aging and Failure Studied by Lateral Force Microscopy

    SciTech Connect (OSTI)

    Ratto, T; Saab, A P

    2009-05-27T23:59:59.000Z

    In the present work, we study, via force microscopy, the basic physical interactions of a single bead of silica filler with a PDMS matrix both before and after exposure to gamma radiation. Our goal was to confirm our results from last year, and to explore force microscopy as a means of obtaining particle-scale polymer/filler interactions suitable for use as empirical inputs to a computational model consisting of an ensemble of silica beads embedded in a PDMS matrix. Through careful calibration of a conventional atomic force microscope, we obtained both normal and lateral force data that was fitted to yield adhesion, surface shear modulus, and friction of a 1 {micro}m silica bead in contact with PDMS layers of various thickness. Comparison of these terms before and after gamma exposure indicated that initially, radiation exposure lead to softening of the PDMS, but eventually resulted in stiffening. Simultaneously, adhesion between the polymer and silica decreased. This could indicate a serious failure path for filled PDMS exposed to radiation, whereby stiffening of the bulk polymer leads to loss of compressive elastic behavior, while a decrease in polymer filler adhesion results in an increased likelihood of stress failure under load. In addition to further testing of radiation damaged polymers, we also performed FEA modeling of silica beads in a silicone matrix using the shear modulus and adhesion values isolated from the force microscopy experiments as model inputs. The resulting simulation indicated that as a polymer stiffens due to impinging radiation, it also undergoes weakening of adhesion to the filler. The implication is that radiation induces a compound failure mode in filled polymer systems.

  18. INTERFACE CRACK PROPAGATION IN POROUS AND TIME-DEPENDENT MATERIALS ANALYZED WITH

    E-Print Network [OSTI]

    Boyer, Edmond

    INTERFACE CRACK PROPAGATION IN POROUS AND TIME-DEPENDENT MATERIALS ANALYZED WITH DISCRETE MODELS and the FPZ. From the point of view of design of structures, e.g. reinforced concrete structures, this size size, size effects, creep, ageing, fracture, viscoelastic- ity, time effect, concrete failure, discrete

  19. Monomer-Capped Tin Metal Nanoparticles for Anode Materials in Lithium Secondary Batteries

    E-Print Network [OSTI]

    Cho, Jaephil

    Monomer-Capped Tin Metal Nanoparticles for Anode Materials in Lithium Secondary Batteries Mijung Graphite can store 372 mAh/g corresponding to LiC6, and tin can store 970 mAh/g corresponding to Li4.4Sn close to graphite. The reason for failure is believed to be the inhomogeneous volume expansion

  20. Validity and failure of some entropy inequalities for CAR systems

    E-Print Network [OSTI]

    Hajime Moriya

    2005-01-26T23:59:59.000Z

    Basic properties of von Neumann entropy such as the triangle inequality and what we call MONO-SSA are studied for CAR systems. We show that both inequalities hold for any even state. We construct a certain class of noneven states giving counter examples of those inequalities. It is not always possible to extend a set of prepared states on disjoint regions to some joint state on the whole region for CAR systems. However, for every even state, we have its `symmetric purification' by which the validity of those inequalities is shown. Some (realized) noneven states have peculiar state correlations among subsystems and induce the failure of those inequalities.

  1. Acute Liver Failure After a Late TIPSS Revision

    SciTech Connect (OSTI)

    Radeleff, Boris, E-mail: Boris_radeleff@med.uni-heidelberg.de; Sommer, Christof-Matthias; Schawo, Simone; Lopez-Benitez, Ruben [University of Heidelberg, Department of Diagnostic Radiology (Germany); Sauer, Peter [University of Heidelberg, Departments of Internal Medicine IV, Gastroenterology, Hepatology, Infectious Diseases, Intoxications (Germany); Schemmer, Peter [University of Heidelberg, Department of Surgery (Germany); Kauffmann, Guenter W.; Richter, Goetz M. [University of Heidelberg, Department of Diagnostic Radiology (Germany)

    2008-01-15T23:59:59.000Z

    We report a rare case of late transjugular intrahepatic portosystemic stent shunt (TIPSS) occlusion due to progressive stent protrusion into the periportal liver parenchyma, which was a result of delayed liver shrinkage 2 years after TIPSS. The initial TIPSS procedure had been carried out in a 52-year-old man as a bridge for liver transplantation because of post-alcoholic liver cirrhosis. We describe the applied TIPSS recanalization and revision technique. Immediately after TIPSS revision acute liver failure developed, which required emergency liver transplantation.

  2. Election in complete asynchronous networks with intermittent link failures 

    E-Print Network [OSTI]

    Lokre, Jahnavi V.

    1991-01-01T23:59:59.000Z

    . Initially, no node knows the identifier of any other node. Each node u knows the number of nodes n in the distributed system, the maximum number f of faulty links incident on u, and that the network is complete. A distributed algorithm on a network is a.... The algorithm uses O(n + nf ) messages. We assume that there are at most f faulty links incident on each node, where f & [ "s J. Let I be a link between nodes u and v. By the definition of link failure, link I is considered faulty if I loses at least one...

  3. Weld monitor and failure detector for nuclear reactor system

    DOE Patents [OSTI]

    Sutton, Jr., Harry G. (Mt. Lebanon, PA)

    1987-01-01T23:59:59.000Z

    Critical but inaccessible welds in a nuclear reactor system are monitored throughout the life of the reactor by providing small aperture means projecting completely through the reactor vessel wall and also through the weld or welds to be monitored. The aperture means is normally sealed from the atmosphere within the reactor. Any incipient failure or cracking of the weld will cause the environment contained within the reactor to pass into the aperture means and thence to the outer surface of the reactor vessel where its presence is readily detected.

  4. Failure of microcausality in quantum field theory on noncommutative spacetime

    SciTech Connect (OSTI)

    Greenberg, O.W. [High Energy Physics Division, Department of Physical Sciences, University of Helsinki, FIN-00014, Helsinki (Finland)

    2006-02-15T23:59:59.000Z

    The commutator of ratio {phi}(x)*{phi}(x) ratio with {partial_derivative}{sub {mu}}{sup y} ratio {phi}(y)*{phi}(y) ratio fails to vanish at equal times and thus also fails to obey microcausality at spacelike separation even for the case in which {theta}{sup 0i}=0. The failure to obey microcausality for these sample observables implies that this form of noncommutative field theory fails to obey microcausality in general. This result holds generally when there are time derivatives in the observables. We discuss possible responses to this problem.

  5. Component failures at pressurized water reactors. Final report

    SciTech Connect (OSTI)

    Reisinger, M.F.

    1980-10-01T23:59:59.000Z

    Objectives of this study were to identify those systems having major impact on safety and availability (i.e. to identify those systems and components whose failures have historically caused the greatest number of challenges to the reactor protective systems and which have resulted in greatest loss of electric generation time). These problems were identified for engineering solutions and recommendations made for areas and programs where research and development should be concentrated. The program was conducted in three major phases: Data Analysis, Engineering Evaluation, Cost Benefit Analysis.

  6. Sandia Energy - Failure Mode and Effect Analysis (FMEA) Tutorial

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

    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: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level: National5Sales for4,645U.S. DOE Office of Scienceand RequirementsCoatingsUltra-High-Voltage SiliconEnergyFailure Mode and Effect Analysis

  7. The Impact of Preradiation Residual Disease Volume on Time to Locoregional Failure in Cutaneous Merkel Cell Carcinoma—A TROG Substudy

    SciTech Connect (OSTI)

    Finnigan, Renee [Division of Cancer Services, Princess Alexandra Hospital, University of Queensland, Brisbane (Australia)] [Division of Cancer Services, Princess Alexandra Hospital, University of Queensland, Brisbane (Australia); Hruby, George [Department of Radiation Oncology, Sydney Cancer Centre, University of Sydney, Sydney (Australia)] [Department of Radiation Oncology, Sydney Cancer Centre, University of Sydney, Sydney (Australia); Wratten, Chris [Calvary Mater Newcastle Hospital, Newcastle (Australia)] [Calvary Mater Newcastle Hospital, Newcastle (Australia); Keller, Jacqui; Tripcony, Lee; Dickie, Graeme [Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane (Australia)] [Cancer Care Services, Royal Brisbane and Women's Hospital, Brisbane (Australia); Rischin, Danny [Department of Medical Oncology, Peter MacCallum Cancer Centre, University of Melbourne, Melbourne (Australia)] [Department of Medical Oncology, Peter MacCallum Cancer Centre, University of Melbourne, Melbourne (Australia); Poulsen, Michael, E-mail: michael_poulsen@health.qld.gov.au [Division of Cancer Services, Princess Alexandra Hospital, University of Queensland, Brisbane (Australia)] [Division of Cancer Services, Princess Alexandra Hospital, University of Queensland, Brisbane (Australia)

    2013-05-01T23:59:59.000Z

    Purpose: This study evaluated the impact of margin status and gross residual disease in patients treated with chemoradiation therapy for high-risk stage I and II Merkel cell cancer (MCC). Methods and Materials: Data were pooled from 3 prospective trials in which patients were treated with 50 Gy in 25 fractions to the primary lesion and draining lymph nodes and 2 schedules of carboplatin based chemotherapy. Time to locoregional failure was analyzed according to the burden of disease at the time of radiation therapy, comparing patients with negative margins, involved margins, or macroscopic disease. Results: Analysis was performed on 88 patients, of whom 9 had microscopically positive resection margins and 26 had macroscopic residual disease. The majority of gross disease was confined to nodal regions. The 5-year time to locoregional failure, time to distant failure, time to progression, and disease-specific survival rates for the whole group were 73%, 69%, 62%, and 66% respectively. The hazard ratio for macroscopic disease at the primary site or the nodes was 1.25 (95% confidence interval 0.57-2.77), P=.58. Conclusions: No statistically significant differences in time to locoregional failure were identified between patients with negative margins and those with microscopic or gross residual disease. These results must, however, be interpreted with caution because of the limited sample size.

  8. Fundamental Approach to Electrode Fabrication and Failure Analysis...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    and Vehicle Technologies Program Annual Merit Review and Peer Evaluation es081battaglia2011o.pdf More Documents & Publications Scale-up and Testing of Advanced Materials...

  9. Photomultiplier tube failure under hydrostatic pressure in future neutrino detectors

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chambliss, K.; Diwan, M.; Simos, N.; Sundaram, S. K.

    2014-10-01T23:59:59.000Z

    Failure of photomultiplier tubes (PMTs) under hydrostatic pressure is a concern in neutrino detection, specifically, in the proposed Long-Baseline Neutrino Experiment project. Controlled hydrostatic implosion tests were performed on prototypic PMT bulbs of 10-inch diameter and recorded using high speed filming techniques to capture failures in detail. These high-speed videos were analyzed frame-by-frame in order to identify the origin of a crack, measure the progression of individual crack along the surface of the bulb as it propagates through the glass, and estimate crack velocity. Crack velocity was calculated for each individual crack, and an average velocity was determined for allmore »measurable cracks on each bulb. Overall, 32 cracks were measured in 9 different bulbs tested. Finite element modeling (FEM) of crack formation and growth in prototypic PMT shows stress concentration near the middle section of the PMT bulbs that correlates well with our crack velocity measurements in that section. The FEM model predicts a crack velocity value that is close to the terminal crack velocity reported. Our measurements also reveal significantly reduced crack velocities compared to terminal crack velocities measured in glasses using fracture mechanics testing and reported in literature.« less

  10. Photomultiplier tube failure under hydrostatic pressure in future neutrino detectors

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Chambliss, K. [Alfred Univ., Alfred, NY (United States). Multifunctional Materials Lab, Kazuo Inamori School of Engineering; Diwan, M. [Alfred Univ., Alfred, NY (United States). Multifunctional Materials Lab, Kazuo Inamori School of Engineering; Simos, N. [Brookhaven National Laboratory (BNL), Upton, NY (United States); Sundaram, S. K. [Alfred Univ., Alfred, NY (United States). Brookhaven National Laboratory (BNL), Upton, NY (United States)

    2014-10-01T23:59:59.000Z

    Failure of photomultiplier tubes (PMTs) under hydrostatic pressure is a concern in neutrino detection, specifically, in the proposed Long-Baseline Neutrino Experiment project. Controlled hydrostatic implosion tests were performed on prototypic PMT bulbs of 10-inch diameter and recorded using high speed filming techniques to capture failures in detail. These high-speed videos were analyzed frame-by-frame in order to identify the origin of a crack, measure the progression of individual crack along the surface of the bulb as it propagates through the glass, and estimate crack velocity. Crack velocity was calculated for each individual crack, and an average velocity was determined for all measurable cracks on each bulb. Overall, 32 cracks were measured in 9 different bulbs tested. Finite element modeling (FEM) of crack formation and growth in prototypic PMT shows stress concentration near the middle section of the PMT bulbs that correlates well with our crack velocity measurements in that section. The FEM model predicts a crack velocity value that is close to the terminal crack velocity reported. Our measurements also reveal significantly reduced crack velocities compared to terminal crack velocities measured in glasses using fracture mechanics testing and reported in literature.

  11. RECONFIGURING POWER SYSTEMS TO MINIMIZE CASCADING FAILURES: MODELS AND ALGORITHMS

    SciTech Connect (OSTI)

    Bienstock, Daniel

    2014-04-11T23:59:59.000Z

    the main goal of this project was to develop new scientific tools, based on optimization techniques, with the purpose of controlling and modeling cascading failures of electrical power transmission systems. We have developed a high-quality tool for simulating cascading failures. The problem of how to control a cascade was addressed, with the aim of stopping the cascade with a minimum of load lost. Yet another aspect of cascade is the investigation of which events would trigger a cascade, or more appropriately the computation of the most harmful initiating event given some constraint on the severity of the event. One common feature of the cascade models described (indeed, of several of the cascade models found in the literature) is that we study thermally-induced line tripping. We have produced a study that accounts for exogenous randomness (e.g. wind and ambient temperature) that could affect the thermal behavior of a line, with a focus on controlling the power flow of the line while maintaining safe probability of line overload. This was done by means of a rigorous analysis of a stochastic version of the heat equation. we incorporated a model of randomness in the behavior of wind power output; again modeling an OPF-like problem that uses chance-constraints to maintain low probability of line overloads; this work has been continued so as to account for generator dynamics as well.

  12. Test-to-Failure of Crystalline Silicon Modules: Preprint

    SciTech Connect (OSTI)

    Hacke, P.; Terwilliger, K.; Glick, S.; Trudell, D.; Bosco, N.; Johnston, S.; Kurtz, S. R.

    2010-10-01T23:59:59.000Z

    Accelerated lifetime testing of five crystalline silicon module designs was carried out according to the Terrestrial Photovoltaic Module Accelerated Test-to-Failure Protocol. This protocol compares the reliability of various module constructions on a quantitative basis. The modules under test are subdivided into three accelerated lifetime testing paths: 85..deg..C/85% relative humidity with system bias, thermal cycling between ?40..deg..C and 85..deg..C, and a path that alternates between damp heat and thermal cycling. The most severe stressor is damp heat with system bias applied to simulate the voltages that modules experience when connected in an array. Positive 600 V applied to the active layer with respect to the grounded module frame accelerates corrosion of the silver grid fingers and degrades the silicon nitride antireflective coating on the cells. Dark I-V curve fitting indicates increased series resistance and saturation current around the maximum power point; however, an improvement in junction recombination characteristics is obtained. Shunt paths and cell-metallization interface failures are seen developing in the silicon cells as determined by electroluminescence, thermal imaging, and I-V curves in the case of negative 600 V bias applied to the active layer. Ability to withstand electrolytic corrosion, moisture ingress, and ion drift under system voltage bias are differentiated.

  13. ISSUES ASSOCIATED WITH PROBABILISTIC FAILURE MODELING OF DIGITAL SYSTEMS

    SciTech Connect (OSTI)

    CHU,T.L.; MARTINEZ-GURIDI,G.; LEHNER,J.; OVERLAND,D.

    2004-09-19T23:59:59.000Z

    The current U.S. Nuclear Regulatory Commission (NRC) licensing process of instrumentation and control (I&C) systems is based on deterministic requirements, e.g., single failure criteria, and defense in depth and diversity. Probabilistic considerations can be used as supplements to the deterministic process. The National Research Council has recommended development of methods for estimating failure probabilities of digital systems, including commercial off-the-shelf (COTS) equipment, for use in probabilistic risk assessment (PRA). NRC staff has developed informal qualitative and quantitative requirements for PRA modeling of digital systems. Brookhaven National Laboratory (BNL) has performed a review of the-state-of-the-art of the methods and tools that can potentially be used to model digital systems. The objectives of this paper are to summarize the review, discuss the issues associated with probabilistic modeling of digital systems, and identify potential areas of research that would enhance the state of the art toward a satisfactory modeling method that could be integrated with a typical probabilistic risk assessment.

  14. Parallel algorithms with processor failures and delays. Technical report

    SciTech Connect (OSTI)

    Buss, J.F.; Kanellakis, P.C.; Radge, P.L.; Shvartsman, A.A.

    1991-08-01T23:59:59.000Z

    The authors study efficient deterministic parallel algorithms on two models: restartable fail-stop CRCW PRAMs and strongly asynchronous PRAMs. In the first model, synchronous processors are subject to arbitrary stop failures and restarts determined by an on-line adversary and involving loss of private but not shared memory; the complexity measures are completed work (where processors are charged for completed fixed-size update cycles) and overhead ratio (completed work amortized over necessary work and failure). In the second model, the result of the computation is a serialization of the actions of the processors determined by an on-line adversary; the complexity measure is total work (number of steps taken by all processors). Despite their differences the two models share key algorithmic techniques. They present new algorithms for the Write-All problem (in which P processors write ones into an array of size N) for these two models. These algorithms can be used to implement a simulation strategy for any N processor PRAM on a restartable fail-stop P processor CRCW PRAM such that it guarantees a terminating execution of each simulated N processor step, with O(log sq N) overhead ratio.

  15. Material review of Li ion battery separators

    SciTech Connect (OSTI)

    Weber, Christoph J., E-mail: Christoph.Weber@freudenberg-nw.com; Geiger, Sigrid, E-mail: Christoph.Weber@freudenberg-nw.com [Freudenberg Vliesstoffe SE and Co KG, 69465 Weinheim (Germany); Falusi, Sandra; Roth, Michael [Freudenberg Forschungsdienste SE and Co KG, 69465 Weinheim (Germany)

    2014-06-16T23:59:59.000Z

    Separators for Li Ion batteries have a strong impact on cell production, cell performance, life, as well as reliability and safety. The separator market volume is about 500 million m{sup 2} mainly based on consumer applications. It is expected to grow strongly over the next decade for mobile and stationary applications using large cells. At present, the market is essentially served by polyolefine membranes. Such membranes have some technological limitations, such as wettability, porosity, penetration resistance, shrinkage and meltdown. The development of a cell failure due to internal short circuit is potentially closely related to separator material properties. Consequently, advanced separators became an intense area of worldwide research and development activity in academia and industry. New separator technologies are being developed especially to address safety and reliability related property improvements.

  16. Failure mechanisms in composite panels subjected to underwater impulsive loads

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    Accepted 15 April 2011 Available online 21 April 2011 Keywords: Composite materials Fluid reinforced plastic (GRP) composite materials are of current interest in naval hull construction (Mouritz et of Solids 59 (2011) 1623­1646 #12;designers interested in fast and stealth marine structures. Two different

  17. RISK-BASED EVALUATION OF OPERATING RESTRICTIONS TO REDUCE THE RISK OF EARTHQUAKE-INDUCED DAM FAILURE

    E-Print Network [OSTI]

    Bowles, David S.

    and consequences of an Earthquake-induced dam failure. The potential for both a sudden overtopping failure-induced dam failure, and the estimated residual risk and degree of risk-based justification for the Existing into the relationship between pool elevation and dam failure risk, provided important inputs for the decision

  18. Materials Science and Materials Chemistry for Large Scale Electrochemi...

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

    Science and Materials Chemistry for Large Scale Electrochemical Energy Storage: From Transportation to Electrical Grid Materials Science and Materials Chemistry for Large Scale...

  19. FY 2009 Progress Report for Lightweighting Materials - 12. Materials...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    for Lightweighting Materials - 12. Materials Crosscutting Research and Development The primary Lightweight Materials activity goal is to validate a cost-effective weight reduction...

  20. ADVANCED MATERIALS Curriculum Biomaterials Materials Science I 5 CP Materials Science II 5 CP Lab Materials Science II 5 CP

    E-Print Network [OSTI]

    Pfeifer, Holger

    ADVANCED MATERIALS Curriculum Biomaterials Materials Science I 5 CP Materials Science II 5 CP Lab Materials Science II 5 CP Computational Methods in Materials Science 4 CP Lab Materials Science I 5 CP Physical Chemistry 4 CP General Chemistry 2 CP Synthesis of Org. & Inorg. Materials 4 CP Introductory Solid

  1. Absolute nuclear material assay

    DOE Patents [OSTI]

    Prasad, Manoj K. (Pleasanton, CA); Snyderman, Neal J. (Berkeley, CA); Rowland, Mark S. (Alamo, CA)

    2012-05-15T23:59:59.000Z

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  2. Absolute nuclear material assay

    DOE Patents [OSTI]

    Prasad, Manoj K. (Pleasanton, CA); Snyderman, Neal J. (Berkeley, CA); Rowland, Mark S. (Alamo, CA)

    2010-07-13T23:59:59.000Z

    A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises utilizing a random sampling of analytically computed fission chain distributions to generate a continuous time-evolving sequence of event-counts by spreading the fission chain distribution in time.

  3. Vibrational Damping of Composite Materials

    E-Print Network [OSTI]

    Biggerstaff, Janet M.

    2006-01-01T23:59:59.000Z

    Smart Structures and Materials, 3989:531- 538. Biggerstaff,2002. “Electroviscoelastic Materials As Active Dampers”,Smart Structures and Materials, 4695:345-350. Biggerstaff,

  4. Deformation Mechanisms in Nanocrystalline Materials

    E-Print Network [OSTI]

    Mohamed, Farghalli A.; Yang, Heather

    2010-01-01T23:59:59.000Z

    2010 METALLURGICAL AND MATERIALS TRANSACTIONS A 47. F.A.12. METALLURGICAL AND MATERIALS TRANSACTIONS A VOLUME 41A,of Slip: Progress in Materials Science, Pergamon Press,

  5. Advanced Materials | More Science | ORNL

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

    Advanced Materials SHARE Advanced Materials ORNL has the nation's most comprehensive materials research program and is a world leader in research that supports the development of...

  6. Wide Bandgap Materials

    Broader source: Energy.gov (indexed) [DOE]

    Materials Madhu Chinthavali Oak Ridge National Laboratory May 15, 2012 Project ID: APE007 This presentation does not contain any proprietary, confidential, or otherwise restricted...

  7. Critical Materials Strategy Summary

    Broader source: Energy.gov (indexed) [DOE]

    in magnets, batteries, photovoltaic films and phosphors; environmentally sound mining and materials processing; and recycling. The eight programs and policies address...

  8. Radioactive Material Transportation Practices

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

    2002-09-23T23:59:59.000Z

    Establishes standard transportation practices for Departmental programs to use in planning and executing offsite shipments of radioactive materials including radioactive waste. Does not cancel other directives.

  9. Management of Nuclear Materials

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

    2009-08-17T23:59:59.000Z

    To establish requirements for the lifecycle management of DOE owned and/or managed accountable nuclear materials. Cancels DOE O 5660.1B.

  10. UESC Workshop Materials

    Broader source: Energy.gov (indexed) [DOE]

    Policy Act (NEPA) Detailed disposal requirements statement for hazardous materials related to the project are essential It is in the FAR Subpart 23.3. Acquisition...

  11. Geopolymer Sealing Materials

    Broader source: Energy.gov (indexed) [DOE]

    Geopolymer Sealing Materials PI : Dr. Tomas Butcher Presenter: Dr. Toshi Sugama Brookhaven National Laboratory May 18, 2010 This presentation does not contain any proprietary...

  12. Materials for MA 182.

    E-Print Network [OSTI]

    Materials for MA 182. INSTRUCTOR: Richard Penney. Office: MATH 822: Telephone: 494-1968: e-mail: rcp@math.purdue.edu: Office Hours: Mon, Tu, Fri,

  13. Layered Cathode Materials

    Broader source: Energy.gov (indexed) [DOE]

    Layered Cathode Materials presented by Michael Thackeray Chemical Sciences and Engineering Division, Argonne Annual Merit Review DOE Vehicle Technologies Program Washington, D.C....

  14. EMSL - battery materials

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

    battery-materials en Modeling Interfacial Glass-Water Reactions: Recent Advances and Current Limitations. http:www.emsl.pnl.govemslwebpublicationsmodeling-interfacial-glass-wa...

  15. Thermoelectric materials having porosity

    DOE Patents [OSTI]

    Heremans, Joseph P.; Jaworski, Christopher M.; Jovovic, Vladimir; Harris, Fred

    2014-08-05T23:59:59.000Z

    A thermoelectric material and a method of making a thermoelectric material are provided. In certain embodiments, the thermoelectric material comprises at least 10 volume percent porosity. In some embodiments, the thermoelectric material has a zT greater than about 1.2 at a temperature of about 375 K. In some embodiments, the thermoelectric material comprises a topological thermoelectric material. In some embodiments, the thermoelectric material comprises a general composition of (Bi.sub.1-xSb.sub.x).sub.u(Te.sub.1-ySe.sub.y).sub.w, wherein 0.ltoreq.x.ltoreq.1, 0.ltoreq.y.ltoreq.1, 1.8.ltoreq.u.ltoreq.2.2, 2.8.ltoreq.w.ltoreq.3.2. In further embodiments, the thermoelectric material includes a compound having at least one group IV element and at least one group VI element. In certain embodiments, the method includes providing a powder comprising a thermoelectric composition, pressing the powder, and sintering the powder to form the thermoelectric material.

  16. Composite of refractory material

    DOE Patents [OSTI]

    Holcombe, Cressie E. (Knoxville, TN); Morrow, Marvin S. (Kingston, TN)

    1994-01-01T23:59:59.000Z

    A composite refractory material composition comprises a boron carbide matrix and minor constituents of yttrium-boron-oxygen-carbon phases uniformly distributed throughout the boron carbide matrix.

  17. LANSCE | Materials Test Station

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

    Research Facility Training Office Contact Administrative nav background Materials Test Station dotline Testing New Reactor Fuels that Reduce Radioactive Waste Mission Used...

  18. Fluorinated elastomeric materials

    DOE Patents [OSTI]

    Lagow, Richard J. (6204 Shadow Mountain, Austin, TX 78731); Dumitru, Earl T. (10116 Aspen St., Austin, TX 78758)

    1986-11-04T23:59:59.000Z

    This invention relates to a method of making perfluorinated elastomeric materials, and to materials made by such methods. In the full synthetic scheme, a partially fluorinated polymeric compound, with moieties to prevent crystallization, is created. It is then crosslinked to a desired degree, then perfluorinated. Various intermediate materials, such as partially fluorinated crosslinked polymers, have useful properties, and are or may become commercially available. One embodiment of this invention therefore relates to perfluorination of a selected partially fluorinated, crosslinked material, which is one step of the full synthetic scheme.

  19. Fluorinated elastomeric materials

    DOE Patents [OSTI]

    Lagow, Richard J. (6204 Shadow Mountain, Austin, TX 78731); Dumitru, Earl T. (10116 Aspen St., Austin, TX 78758)

    1990-02-13T23:59:59.000Z

    This invention relates to a method of making perfluorinated elastomeric materials, and to materials made by such methods. In the full synthetic scheme, a partially fluorinated polymeric compound, with moieties to prevent crystallization, is created. It is then crosslinked to a desired degree, then perfluorinated. Various intermediate materials, such as partially fluorinated crosslinked polymers, have useful properties, and are or may become commercially available. One embodiment of this invention therefore relates to perfluorination of a selected partially fluorinated, crosslinked material, which is one step of the full synthetic scheme.

  20. Composite of refractory material

    DOE Patents [OSTI]

    Holcombe, C.E.; Morrow, M.S.

    1994-07-19T23:59:59.000Z

    A composite refractory material composition comprises a boron carbide matrix and minor constituents of yttrium-boron-oxygen-carbon phases uniformly distributed throughout the boron carbide matrix.

  1. Radiation Safety Training Materials

    Broader source: Energy.gov [DOE]

    The following Handbooks and Standard provide recommended hazard specific training material for radiological workers at DOE facilities and for various activities.

  2. DOE Automotive Lightweighting Materials

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    materials for fiber reinforced composites. Until now, they have only been used in the automotive industry with thermoplastics and not as a matrix for fiber reinforced...

  3. Webinar: Materials Genome Initative

    Broader source: Energy.gov [DOE]

    Audio recording and text version of the Fuel Cell Technologies Office webinar titled "Materials Genome Initiative," originally presented on December 2, 2014.

  4. Hazardous Material Security (Maryland)

    Broader source: Energy.gov [DOE]

    All facilities processing, storing, managing, or transporting hazardous materials must be evaluated every five years for security issues. A report must be submitted to the Department of the...

  5. Preliminary Failure Modes and Effects Analysis of the US Massive Gas Injection Disruption Mitigation System Design

    SciTech Connect (OSTI)

    Lee C. Cadwallader

    2013-10-01T23:59:59.000Z

    This report presents the results of a preliminary failure modes and effects analysis (FMEA) of a candidate design for the ITER Disruption Mitigation System. This candidate is the Massive Gas Injection System that provides machine protection in a plasma disruption event. The FMEA was quantified with “generic” component failure rate data as well as some data calculated from operating facilities, and the failure events were ranked for their criticality to system operation.

  6. Preliminary Failure Modes and Effects Analysis of the US DCLL Test Blanket Module

    SciTech Connect (OSTI)

    Lee C. Cadwallader

    2010-06-01T23:59:59.000Z

    This report presents the results of a preliminary failure modes and effects analysis (FMEA) of a small tritium-breeding test blanket module design for the International Thermonuclear Experimental Reactor. The FMEA was quantified with “generic” component failure rate data, and the failure events are binned into postulated initiating event families and frequency categories for safety assessment. An appendix to this report contains repair time data to support an occupational radiation exposure assessment for test blanket module maintenance.

  7. Materials and Metallurgy Materials Science and Metallurgical Engineering

    E-Print Network [OSTI]

    Provancher, William

    Materials and Metallurgy Materials Science and Metallurgical Engineering Objective Students "Rocks and Materials Science" Presentation. Review uses of rocks. Explain that engineers extract Engineers to efficiently and safely extract ore, Metallurgical Engineers to refine the copper, and Materials

  8. Probability of loss of assured safety in systems with multiple time-dependent failure modes.

    SciTech Connect (OSTI)

    Helton, Jon Craig; Pilch, Martin M.; Sallaberry, Cedric M.

    2012-09-01T23:59:59.000Z

    Weak link (WL)/strong link (SL) systems are important parts of the overall operational design of high-consequence systems. In such designs, the SL system is very robust and is intended to permit operation of the entire system under, and only under, intended conditions. In contrast, the WL system is intended to fail in a predictable and irreversible manner under accident conditions and render the entire system inoperable before an accidental operation of the SL system. The likelihood that the WL system will fail to deactivate the entire system before the SL system fails (i.e., degrades into a configuration that could allow an accidental operation of the entire system) is referred to as probability of loss of assured safety (PLOAS). Representations for PLOAS for situations in which both link physical properties and link failure properties are time-dependent are derived and numerically evaluated for a variety of WL/SL configurations, including PLOAS defined by (i) failure of all SLs before failure of any WL, (ii) failure of any SL before failure of any WL, (iii) failure of all SLs before failure of all WLs, and (iv) failure of any SL before failure of all WLs. The effects of aleatory uncertainty and epistemic uncertainty in the definition and numerical evaluation of PLOAS are considered.

  9. APC mutations lead to cytokinetic failures in vitro and tetraploid genotypes in Min mice

    E-Print Network [OSTI]

    Caldwell, Christine M; Green, Rebecca A; Kaplan, Kenneth B

    2007-01-01T23:59:59.000Z

    JCB: ARTICLE APC mutations lead to cytokinetic failures inpre- cise mechanisms that lead to the chromosomal defects inanaphase begins. APC MUTANTS LEAD TO TETRAPLOID CELLS IN

  10. A coupled biventricular finite element and lumped-parameter circulatory system model of heart failure

    E-Print Network [OSTI]

    2013-01-01T23:59:59.000Z

    Circulatory System Model of Heart Failure Jonathan F. Wenk,contracting regions of the heart. These single ventricledilation and help remodel the heart towards a normal state.

  11. adenine-induced renal failure: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  12. acetaminophen-induced liver failure: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  13. acute-on-chronic liver failure: Topics by E-print Network

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

    GEOSYNTHETICS Engineering Websites Summary: failure involving a reinforced geosynthetic clay liner in a sedimentation pond at a waste containment liners to hydrate during on-site...

  14. Failure and Degradation Modes of PV Modules in a Hot Dry Climate...

    Office of Environmental Management (EM)

    Report Delamination Failures in Long-Term Field Aged PV Modules from Point of View of Encapsulant Accelerated Stress Testing, Qualification Testing, HAST, Field Experience...

  15. Selected Component Failure Rate Values from Fusion Safety Assessment Tasks

    SciTech Connect (OSTI)

    Cadwallader, Lee Charles

    1998-09-01T23:59:59.000Z

    This report is a compilation of component failure rate and repair rate values that can be used in magnetic fusion safety assessment tasks. Several safety systems are examined, such as gas cleanup systems and plasma shutdown systems. Vacuum system component reliability values, including large vacuum chambers, have been reviewed. Values for water cooling system components have also been reported here. The report concludes with the examination of some equipment important to personnel safety, atmospheres, combustible gases, and airborne releases of radioactivity. These data should be useful to system designers to calculate scoping values for the availability and repair intervals for their systems, and for probabilistic safety or risk analysts to assess fusion systems for safety of the public and the workers.

  16. Cascade Failures from Distributed Generation in Power Grids

    E-Print Network [OSTI]

    Scala, Antonio; Scoglio, Caterina

    2012-01-01T23:59:59.000Z

    Power grids are nowadays experiencing a transformation due to the introduction of Distributed Generation based on Renewable Sources. At difference with classical Distributed Generation, where local power sources mitigate anomalous user consumption peaks, Renewable Sources introduce in the grid intrinsically erratic power inputs. By introducing a simple schematic (but realistic) model for power grids with stochastic distributed generation, we study the effects of erratic sources on the robustness of several IEEE power grid test networks with up to 2000 buses. We find that increasing the penetration of erratic sources causes the grid to fail with a sharp transition. We compare such results with the case of failures caused by the natural increasing power demand.

  17. Module Design, Materials, and Packaging Research Team: Activities and Capabilities

    SciTech Connect (OSTI)

    McMahon, T. J.; del Cueto, J.; Glick, S.; Jorgensen, G.; Kempe, M.; Kennedy, C.; Pern, J.; Terwilliger, K

    2005-01-01T23:59:59.000Z

    Our team activities are directed at improving PV module reliability by incorporating new, more effective, and less expensive packaging materials and techniques. New and existing materials or designs are evaluated before and during accelerated environmental exposure for the following properties: (1) Adhesion and cohesion: peel strength and lap shear. (2) Electrical conductivity: surface, bulk, interface and transients. (3) Water vapor transmission: solubility and diffusivity. (4) Accelerated weathering: ultraviolet, temperature, and damp heat tests. (5) Module and cell failure diagnostics: infrared imaging, individual cell shunt characterization, coring. (6) Fabrication improvements: SiOxNy barrier coatings and enhanced wet adhesion. (7) Numerical modeling: Moisture ingress/egress, module and cell performance, and cell-to-frame leakage current. (8) Rheological properties of polymer encapsulant and sheeting materials. Specific examples will be described.

  18. Consolidation and shear failure leading to subsidence and settlement. Part I

    SciTech Connect (OSTI)

    Abeele, W.V.

    1985-11-01T23:59:59.000Z

    Subsidence and settlement are phenomena that are much more destructive than generally thought. In shallow land burials they may lead to cracking of the overburden and eventual exposure and escape of waste material. The primary causes are consolidation and cave-ins. Laboratory studies performed at Los Alamos permit us to predict settlement caused by consolidation or natural compaction of the crushed tuff overburden. We have also investigated the shear failure characteristics of crushed tuff that may lead to subsidence. Examples of expected settlement and subsidence are calculated based on the known geotechnical characteristics of crushed tuff. The same thing is done for bontonite/tuff mixes because some field experiments were performed using this additive (bentonite) to reduce the hydraulic conductivity of the crushed tuff. Remedial actions, i.e., means to limit the amount of settlement, are discussed. Finally, we briefly comment on our current field experiment, which studies the influence of subsidence on layered systems in general and on biombarriers in particular.

  19. Consolidation and shear failure leading to subsidence and settlement. Final report

    SciTech Connect (OSTI)

    Abeele, W.; Nyhan, J.W.; Hakonson, T.E.; Drennon, B.J.; Lopez, E.A.; Herrera, W.J.; Langhorst, G.J.; Martinez, J.L.; Trujillo, G.

    1986-02-01T23:59:59.000Z

    Subsidence and settlement are phenomena that are much more destructive than generally thought. In shallow land burials they may lead to cracking of the overburden and eventual exposure and escape of waste material. The primary causes are consolidation and cave-ins. Laboratory studies performed at Los Alamos permit us to predict settlement caused by consolidation or natural compaction of the crushed tuff overburden. We have also investigated the shear failure characteristics of crushed tuff that may lead to subsidence. Examples of expected settlement and subsidence are calculated based on the known geotechnical characteristics of crushed tuff. The same thing is done for bentonite/tuff mixes because some field experiments were performed using this additive (bentonite) to reduce the hydraulic conductivity of the crushed tuff. Remedial actions, i.e., means to limit the amount of settlement, are discussed. We finally discuss our field experiment, which studies the influence of subsidence on layered systems in general and on biobarriers in particular. The share of the produced cavities is compared with cavities produced by idealized voids in an idealized environment. Study of root penetration at subsidence sites gives us an indication of the remaining degree of integrity. 30 refs., 24 figs., 19 tabs.

  20. From Smart Materials to Cognitive Materials Requirements and Challenges

    E-Print Network [OSTI]

    Bremen, Universität

    From Smart Materials to Cognitive Materials ­ Requirements and Challenges Lutz Frommberger (lutz materials are materials that are either capa- ble of changing some of their properties according to external within the material itself. The latter is also called sensorial material (Lawo et. al., 2009). Recently