National Library of Energy BETA

Sample records for von mises stress

  1. Probability distribution of von Mises stress in the presence of pre-load.

    SciTech Connect (OSTI)

    Segalman, Daniel Joseph; Field, Richard V.; Reese, Garth M.

    2013-04-01

    Random vibration under preload is important in multiple endeavors, including those involving launch and re-entry. There are some methods in the literature to begin to address this problem, but there is nothing that accommodates the existence of preloads and the necessity of making probabilistic statements about the stress levels likely to be encountered. An approach to achieve to this goal is presented along with several simple illustrations.

  2. Modeling of stress distributions on the microstructural level in Alloy 600

    SciTech Connect (OSTI)

    Kozaczek, K.J.; Petrovic, B.G.; Ruud, C.O.; Mcllree, A.R.

    1995-04-01

    Stress distribution in a random polycrystalline material (Alloy 600) was studied using a topologically correct microstructural model. Distributions of von Mises and hydrostatic stresses at the grain vertices, which could be important in intergranular stress corrosion cracking, were analyzed as functions of microstructure, grain orientations and loading conditions. Grain size, shape, and orientation had a more pronounced effect on stress distribution than loading conditions. At grain vertices the stress concentration factor was higher for hydrostatic stress (1.7) than for von Mises stress (1.5). The stress/strain distribution in the volume (grain interiors) is a normal distribution and does not depend on the location of the studied material volume i.e., surface vs/bulk. The analysis of stress distribution in the volume showed the von Mises stress concentration of 1.75 and stress concentration of 2.2 for the hydrostatic pressure. The observed stress concentration is high enough to cause localized plastic microdeformation, even when the polycrystalline aggregate is in the macroscopic elastic regime. Modeling of stresses and strains in polycrystalline materials can identify the microstructures (grain size distributions, texture) intrinsically susceptible to stress/strain concentrations and justify the correctness of applied stress state during the stress corrosion cracking tests. Also, it supplies the information necessary to formulate the local failure criteria and interpret of nondestructive stress measurements.

  3. Microsoft Word - Lamellae tungsten tile design thermal and electromagn...

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

    Stress Profile: von Mises; Screw Assy View 1 Temp Profile (281 C) (275 C) (207 C) (440 C) (440 C) (456 C) (484 C) 31 Fig. 3.2.7 - Thermal Stress Profile: von Mises, Screw...

  4. Mise-A-La-Masse At Kilauea East Rift Geothermal Area (Kauahikaua...

    Open Energy Info (EERE)

    likely consist of dike complexes. References James Kauahikaua, Mark Mattice, Dallas Jackson (1980) Mise-A-La-Masse Mapping of the HGP-A Geothermal Reservoir, Hawaii Additional...

  5. TITLE AUTHORS SUBJECT SUBJECT RELATED DESCRIPTION PUBLISHER AVAILABILI...

    Office of Scientific and Technical Information (OSTI)

    MECHANICAL VIBRATIONS TRANSFER FUNCTIONS CALCULATION METHODS FINITE ELEMENT METHOD FOURIER ANALYSIS An efficient method is presented for calculation of RMS von Mises stresses...

  6. vibration environment Segalman, D.J.; Fulcher, C.W.G.; Reese...

    Office of Scientific and Technical Information (OSTI)

    MECHANICAL VIBRATIONS; TRANSFER FUNCTIONS; CALCULATION METHODS; FINITE ELEMENT METHOD; FOURIER ANALYSIS An efficient method is presented for calculation of RMS von Mises stresses...

  7. DC Resistivity Survey (Mise-A-La-Masse) | Open Energy Information

    Open Energy Info (EERE)

    fluid type and phase state of the pore water Thermal: Resistivity influenced by temperature Dictionary.png DC Resistivity Survey (Mise-A-La-Masse): No definition has been...

  8. Stephanie von Numers | Department of Energy

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

    Stephanie von Numers - Communications and Web Coordinator, Education & Workforce Development Stephanie von Numers joined the U.S. Department of Energy's Office of Energy Efficiency ...

  9. Mise-a-la-masse mapping of the HGP-A geothermal reservoir, Hawaii

    SciTech Connect (OSTI)

    Kauahikaua, J.; Mattice, M.; Jackson, D.

    1980-09-01

    The HGP-A well casing was used as an electrode in a mise-a-la-masse experiment to define the boundaries of the geothermal reservoir. Electric potentials were measured to distances of 2 km from the drill hole. Although cased or lined the full 1967 m, only the top 670 m of the HGP-A casing are electrically continuous; the electrode did not extend into the high-temperature part of the reservoir. Nevertheless, the data did define a compartment of dike-impounded freshwater of higher resistivity than the surrounding saltwater-saturated rock. This dike-impounded water is warm and apparently overlies the actual reservoir; however, the lateral boundaries impounding this water probably confine geothermal fluids at depth.

  10. Schweickhard "Schwick" von Goeler, inventor of groundbreaking...

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

    In 1984, von Goeler was awarded the Prize for Excellence in Plasma Physics (now the John Dawson award) by the American Physical Society's Division of Plasma Physics. He was...

  11. Schweickhard "Schwick" von Goeler, inventor of groundbreaking...

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

    the new Wendelstein 7-X stellarator in Germany, the Large Helical Device in Japan, the ... He was killed in 1944 in World War II. Von Goeler grew up during wartime Germany and after ...

  12. Klimov receives Alexander von Humboldt award

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

    Klimov Receives Alexander Von Humboldt Award Klimov receives Alexander von Humboldt award The German government grants the award in recognition of a researcher whose discoveries, theories or insights have had a significant impact on his or her own discipline and who is expected to continue producing cutting-edge achievements in the future. May 16, 2013 Victor Klimov Victor Klimov Klimov is an expert in nanocrystal quantum dots and optical amplification in nanocrystals. Victor Klimov of Physical

  13. Microsoft PowerPoint - 3_FRANK_VON_HIPPEL_NMMSS_2014_screensaver.ppt [Compatibility Mode]

    National Nuclear Security Administration (NNSA)

    Keynote Speaker Professor Frank N. von Hippel Princeton University

  14. Schweickhard "Schwick" von Goeler, inventor of groundbreaking

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

    diagnostics used to analyze fusion experiments worldwide, dies at 84 | Princeton Plasma Physics Lab Schweickhard "Schwick" von Goeler, inventor of groundbreaking diagnostics used to analyze fusion experiments worldwide, dies at 84 By Jeanne Jackson DeVoe December 14, 2015 Tweet Widget Google Plus One Share on Facebook Schweickhard "Schwick" von Goeler Schweickhard "Schwick" von Goeler Schweickhard "Schwick" von Goeler, an award-winning physicist at the

  15. Schweickhard "Schwick" von Goeler, inventor of groundbreaking

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

    diagnostics used to analyze fusion experiments worldwide, dies at 84 | Princeton Plasma Physics Lab Schweickhard "Schwick" von Goeler, inventor of groundbreaking diagnostics used to analyze fusion experiments worldwide, dies at 84 By Jeanne Jackson DeVoe December 14, 2015 Tweet Widget Google Plus One Share on Facebook Schweickhard "Schwick" von Goeler Schweickhard "Schwick" von Goeler Schweickhard "Schwick" von Goeler, an award-winning physicist at the

  16. Von Hippel, at PPPL, calls for international control of nuclear...

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

    ... Difficulties go back to 1953 Iran's difficulties with the United States go back to 1953 when the CIA helped depose Iran's democratically elected government, von Hippel said. ...

  17. Union zur F rderung von Oel und Proteinpflanzen Ufop | Open Energy...

    Open Energy Info (EERE)

    zur F rderung von Oel und Proteinpflanzen Ufop Jump to: navigation, search Name: Union zur Frderung von Oel- und Proteinpflanzen (Ufop) Place: Germany Product: Germany-based...

  18. TBH-0034- In the Matter of Casey von Bargen

    Broader source: Energy.gov [DOE]

    This Initial Agency Decision involves a whistleblower complaint filed by Mr. Casey von Bargen (also referred to as the complainant or the individual) under the Department of Energy (DOE) Contractor...

  19. Von Ardenne Anlagentechnik GmbH | Open Energy Information

    Open Energy Info (EERE)

    1324 Sector: Solar Product: German equipment manufacturer of wafer-based and thin-film solar cells. References: Von Ardenne Anlagentechnik GmbH1 This article is a stub. You...

  20. Interpolatability distinguishes LOCC from separable von Neumann measurements

    SciTech Connect (OSTI)

    Childs, Andrew M.; Leung, Debbie; Man?inska, Laura; Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1 ; Ozols, Maris; Institute for Quantum Computing, University of Waterloo, Waterloo, Ontario N2L 3G1; IBM TJ Watson Research Center, Yorktown Heights, New York 10598

    2013-11-15

    Local operations with classical communication (LOCC) and separable operations are two classes of quantum operations that play key roles in the study of quantum entanglement. Separable operations are strictly more powerful than LOCC, but no simple explanation of this phenomenon is known. We show that, in the case of von Neumann measurements, the ability to interpolate measurements is an operational principle that sets apart LOCC and separable operations.

  1. TBZ-0034 - In the Matter of Casey Von Bargen | Department of Energy

    Office of Environmental Management (EM)

    34 - In the Matter of Casey Von Bargen TBZ-0034 - In the Matter of Casey Von Bargen This Decision concerns a Motion To Dismiss that was filed by Sandia National Laboratories (hereinafter referred to as "SNL" or "the Respondent"). In this Motion, SNL seeks the dismissal of a complaint that was filed by Casey Von Bargen (hereinafter referred to as "Mr. Von Bargen" or "the Complainant") under the Department of Energy's (DOE) Contractor Employee Protection

  2. The von Neumann model of measurement in quantum mechanics

    SciTech Connect (OSTI)

    Mello, Pier A.

    2014-01-08

    We describe how to obtain information on a quantum-mechanical system by coupling it to a probe and detecting some property of the latter, using a model introduced by von Neumann, which describes the interaction of the system proper with the probe in a dynamical way. We first discuss single measurements, where the system proper is coupled to one probe with arbitrary coupling strength. The goal is to obtain information on the system detecting the probe position. We find the reduced density operator of the system, and show how Lders rule emerges as the limiting case of strong coupling. The von Neumann model is then generalized to two probes that interact successively with the system proper. Now we find information on the system by detecting the position-position and momentum-position correlations of the two probes. The so-called 'Wigner's formula' emerges in the strong-coupling limit, while 'Kirkwood's quasi-probability distribution' is found as the weak-coupling limit of the above formalism. We show that successive measurements can be used to develop a state-reconstruction scheme. Finally, we find a generalized transform of the state and the observables based on the notion of successive measurements.

  3. "Title","Creator/Author","Publication Date","OSTI Identifier...

    Office of Scientific and Technical Information (OSTI)

    MECHANICAL VIBRATIONS; TRANSFER FUNCTIONS; CALCULATION METHODS; FINITE ELEMENT METHOD; FOURIER ANALYSIS",,"An efficient method is presented for calculation of RMS von Mises...

  4. Stochastic resonance in a generalized Von Foerster population growth model

    SciTech Connect (OSTI)

    Lumi, N.; Mankin, R.

    2014-11-12

    The stochastic dynamics of a population growth model, similar to the Von Foerster model for human population, is studied. The influence of fluctuating environment on the carrying capacity is modeled as a multiplicative dichotomous noise. It is established that an interplay between nonlinearity and environmental fluctuations can cause single unidirectional discontinuous transitions of the mean population size versus the noise amplitude, i.e., an increase of noise amplitude can induce a jump from a state with a moderate number of individuals to that with a very large number, while by decreasing the noise amplitude an opposite transition cannot be effected. An analytical expression of the mean escape time for such transitions is found. Particularly, it is shown that the mean transition time exhibits a strong minimum at intermediate values of noise correlation time, i.e., the phenomenon of stochastic resonance occurs. Applications of the results in ecology are also discussed.

  5. C.F.von Weizsäcker-Political consequences of science

    ScienceCinema (OSTI)

    None

    2011-04-25

    le DG C.Rubbia remercie le Prof.C.F.von Weizsäcker pour ses trois conférences très intéréssantes

  6. Assessment of an improved multiaxial strength theory based on creep-rupture data for Inconel 600

    SciTech Connect (OSTI)

    Huddleston, R.L.

    1993-06-01

    A new multiaxial strength theory incorporating three independent stress parameters was developed and reported by the author in 1984. It was formally incorporated into ASME Code Case N47-29 in 1990. The new theory provided significantly more accurate stress-rupture life predictions than obtained using the classical theories of von Mises, Tresca, and Rankins (maximum principal stress), for Types 304 and 316 stainless steel tested at 593 and 600{degrees}C respectively under different biaxial stress states. Additional results for Inconel 600 specimens tested at 816{degrees}C under tension-tension and tension-compression stress states are presented in this paper and show a factor of approximately 2.4 reduction in the scatter of predicted versus observed lives as compared to the classical theories of von Mises and Tresca and a factor of about 5 as compared to the Rankins theory. A key feature of the theory, which incorporates the maximum deviatoric stress, the first invariant of the stress tensor, and the second invariant of the deviatoric stress tensor, is its ability to distinguish between life under tensile versus compressive stress states.

  7. John von Neumann, 1956 | U.S. DOE Office of Science (SC)

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

    John von Neumann, 1956 The Enrico Fermi Award Fermi Award Home Nomination & Selection Guidelines Award Laureates 2010's 2000's 1990's 1980's 1970's 1960's 1950's Ceremony The Life of Enrico Fermi Contact Information The Enrico Fermi Award U.S. Department of Energy SC-2/Germantown Building 1000 Independence Ave., SW Washington, DC 20585 P: (301) 903-2411 E: Email Us 1950's John von Neumann, 1956 Print Text Size: A A A FeedbackShare Page Citation For his scientific contribution to the theory

  8. C.F.von Weizsäcker-High Energy Physics

    ScienceCinema (OSTI)

    None

    2011-04-25

    C.F.von Weizsäcker (1912-2007),physicien,philosophe et "chercheur de paix", prit la décision de faire des études de physique sous l'influence de W.Heisenberg qu'il rencontra en 1927.

  9. Stressed state and stress relaxation in rocks

    SciTech Connect (OSTI)

    Lodus, E.V.

    1987-01-01

    This paper continues an experimental investigation of stress relaxation in rocks under various types of stressed states at different deformation phases, including the transcriptional region. The tests were done in the conditions of uniaxial compression, compression under hydrostatic pressures varying up to values at which the rock strength characteristics attained a plateau, and a for bending. All testes with stress relaxation were done in the laboratory on rock samples. The procedures are described. When characterized by the drop of stresses close to the ultimate strengths during the time equal to the first 3 minutes of relaxation, the rocks in tests with uniaxial compression formed the following series according to decreasing relaxation activity: bauxite 57%, brown coal 50%, potassium and rock salt 35%, schist 15% marble 13%, burst-safe sandstone 5%, and apatite 4%. The test data on stress relaxation in rocks make it possible in any mining situation to evaluate the reduction of the released elastic energy due to stress relaxation and, on this basis, determine the potential efficiency of controlling the bed destruction pattern.

  10. Stress Test | Open Energy Information

    Open Energy Info (EERE)

    Stress Test Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Technique: Stress Test Details Activities (1) Areas (1) Regions (0) NEPA(0) Exploration...

  11. Numerical simulation of laminar plasma dynamos in a cylindrical von Karman flow

    SciTech Connect (OSTI)

    Khalzov, I. V.; Brown, B. P.; Schnack, D. D.; Forest, C. B. [University of Wisconsin, 1150 University Avenue, Madison, Wisconsin 53706 (United States); Ebrahimi, F. [University of New Hampshire, 8 College Road, Durham, New Hampshire 03824 (United States)

    2011-03-15

    The results of a numerical study of the magnetic dynamo effect in cylindrical von Karman plasma flow are presented with parameters relevant to the Madison Plasma Couette Experiment. This experiment is designed to investigate a broad class of phenomena in flowing plasmas. In a plasma, the magnetic Prandtl number Pm can be of order unity (i.e., the fluid Reynolds number Re is comparable to the magnetic Reynolds number Rm). This is in contrast to liquid metal experiments, where Pm is small (so, Re>>Rm) and the flows are always turbulent. We explore dynamo action through simulations using the extended magnetohydrodynamic NIMROD code for an isothermal and compressible plasma model. We also study two-fluid effects in simulations by including the Hall term in Ohm's law. We find that the counter-rotating von Karman flow results in sustained dynamo action and the self-generation of magnetic field when the magnetic Reynolds number exceeds a critical value. For the plasma parameters of the experiment, this field saturates at an amplitude corresponding to a new stable equilibrium (a laminar dynamo). We show that compressibility in the plasma results in an increase of the critical magnetic Reynolds number, while inclusion of the Hall term in Ohm's law changes the amplitude of the saturated dynamo field but not the critical value for the onset of dynamo action.

  12. Stress relief of transition zones

    SciTech Connect (OSTI)

    Woodward, J.; van Rooyen, D.

    1984-01-01

    This paper considers the problem of intergranular stress corrosion cracking, initiated on the primary side, in the expansion transition region of roller expanded Alloy 600 tubing. In general it is believed that residual stresses, arising from the expansion process, are the cause of the problem. The work reported here concentrated on the identification of an optimal, in-situ stress relief treatment.

  13. Contact stress sensor

    DOE Patents [OSTI]

    Kotovsky, Jack

    2012-02-07

    A contact stress sensor includes one or more MEMS fabricated sensor elements, where each sensor element of includes a thin non-recessed portion, a recessed portion and a pressure sensitive element adjacent to the recessed portion. An electric circuit is connected to the pressure sensitive element. The circuit includes a thermal compensator and a pressure signal circuit element configured to provide a signal upon movement of the pressure sensitive element.

  14. Contact stress sensor

    DOE Patents [OSTI]

    Kotovsky, Jack

    2014-02-11

    A method for producing a contact stress sensor that includes one or more MEMS fabricated sensor elements, where each sensor element of includes a thin non-recessed portion, a recessed portion and a pressure sensitive element adjacent to the recessed portion. An electric circuit is connected to the pressure sensitive element. The circuit includes a pressure signal circuit element configured to provide a signal upon movement of the pressure sensitive element.

  15. Subterranean stress engineering experiments

    SciTech Connect (OSTI)

    Campbell, J.R.; Colgate, S.A.; Wheat, B.M.

    1980-01-01

    The state of stress in a subterranean rock mass has classically been assumed to be constant at best. In soil with a high clay content, preconsolidation and drainage methods can lead to more stable foundation material, but methods for engineering the stresses in large masses of rock are not well known. This paper shows the results from an experiment designed to alter the in situ rock stress field in an oil shale mine. This was done by hydrofracturing the rock by use of a packed-well injection system and then propping the crack open with a thixotropic gel, which slowly hardened to the consistency of cement. Successive hydrofracture and high-pressure grouting resulted in an overstressed region. Well-head injection pressures, surface tilts, injection rates, and subterranean strains were measured and recorded on floppy disk by a Z-80 microprocessor. The results were then transmitted to the large computer system at the Los Alamos Scientific Laboratory (LASL). To put the data in a more useful form, computer-generated movies of the tilts and strains were made by use of computer graphics developed at LASL. The purpose of this paper is to present results from the Single Large Instrumented Test conducted in the Colony Oil Shale Mine near Rifle, Colorado. 13 figures.

  16. Category:Stress Test | Open Energy Information

    Open Energy Info (EERE)

    Stress Test Jump to: navigation, search Geothermalpower.jpg Looking for the Stress Test page? For detailed information on Stress Test, click here. Category:Stress Test Add.png Add...

  17. A luminescent nanocrystal stress gauge

    SciTech Connect (OSTI)

    Choi, Charina; Koski, Kristie; Olson, Andrew; Alivisatos, Paul

    2010-10-25

    Microscale mechanical forces can determine important outcomes ranging from the site of material fracture to stem cell fate. However, local stresses in a vast majority of systems cannot be measured due to the limitations of current techniques. In this work, we present the design and implementation of the CdSe/CdS core/shell tetrapod nanocrystal, a local stress sensor with bright luminescence readout. We calibrate the tetrapod luminescence response to stress, and use the luminescence signal to report the spatial distribution of local stresses in single polyester fibers under uniaxial strain. The bright stress-dependent emission of the tetrapod, its nanoscale size, and its colloidal nature provide a unique tool that may be incorporated into a variety of micromechanical systems including materials and biological samples to quantify local stresses with high spatial resolution.

  18. HTTF Core Stress Analysis

    SciTech Connect (OSTI)

    Brian D. Hawkes; Richard Schultz

    2012-07-01

    In accordance with the need to determine whether cracking of the ceramic core disks which will be constructed and used in the High Temperature Test Facility (HTTF) for heatup and cooldown experiments, a set of calculation were performed using Abaqus to investigate the thermal stresses levels and likelihood for cracking. The calculations showed that using the material properties provided for the Greencast 94F ceramic, cracking is predicted to occur. However, this modeling does not predict the size or length of the actual cracks. It is quite likely that cracks will be narrow with rough walls which would impede the flow of coolant gases entering the cracks. Based on data recorded at Oregon State University using Greencast 94F samples that were heated and cooled at prescribed rates, it was concluded that the likelihood that the cracks would be detrimental to the experimental objectives is small.

  19. Activated sludge stress testing

    SciTech Connect (OSTI)

    Kurtz, F.H.; Darida, C.J. ); Alam, A.M.Z.; Chien, T. )

    1991-11-01

    In 1989 and 1990, the Middlesex County Utilities Authority (MCUA) conducted a facilities planning study to expand the capacity of the existing 5.2-m{sup 3}/s (120-mgd) treatment plant for treating projected wastewater flows up to the year 2020. As a part of this study, MCUA stress-tested the existing plant facilities - specifically, the UNOX activated sludge reactors and aerobic sludge digesters - to determine the dependable treatment capacity of each unit process. Before establishing expansion needs, it was necessary to determine the real treatment capacities of existing treatment plant facilities and process units as compared to plant design criteria and the effectiveness of the existing treatment systems and their operations, increased plant capacity, and reduced future plant expansion needs and associated construction costs.

  20. Residual stresses and stress corrosion cracking in pipe fittings

    SciTech Connect (OSTI)

    Parrington, R.J.; Scott, J.J.; Torres, F.

    1994-06-01

    Residual stresses can play a key role in the SCC performance of susceptible materials in PWR primary water applications. Residual stresses are stresses stored within the metal that develop during deformation and persist in the absence of external forces or temperature gradients. Sources of residual stresses in pipe fittings include fabrication processes, installation and welding. There are a number of methods to characterize the magnitude and orientation of residual stresses. These include numerical analysis, chemical cracking tests, and measurement (e.g., X-ray diffraction, neutron diffraction, strain gage/hole drilling, strain gage/trepanning, strain gage/section and layer removal, and acoustics). This paper presents 400 C steam SCC test results demonstrating that residual stresses in as-fabricated Alloy 600 pipe fittings are sufficient to induce SCC. Residual stresses present in as-fabricated pipe fittings are characterized by chemical cracking tests (stainless steel fittings tested in boiling magnesium chloride solution) and by the sectioning and layer removal (SLR) technique.

  1. RESIDUAL STRESSES IN 3013 CONTAINERS

    SciTech Connect (OSTI)

    Mickalonis, J.; Dunn, K.

    2009-11-10

    The DOE Complex is packaging plutonium-bearing materials for storage and eventual disposition or disposal. The materials are handled according to the DOE-STD-3013 which outlines general requirements for stabilization, packaging and long-term storage. The storage vessels for the plutonium-bearing materials are termed 3013 containers. Stress corrosion cracking has been identified as a potential container degradation mode and this work determined that the residual stresses in the containers are sufficient to support such cracking. Sections of the 3013 outer, inner, and convenience containers, in both the as-fabricated condition and the closure welded condition, were evaluated per ASTM standard G-36. The standard requires exposure to a boiling magnesium chloride solution, which is an aggressive testing solution. Tests in a less aggressive 40% calcium chloride solution were also conducted. These tests were used to reveal the relative stress corrosion cracking susceptibility of the as fabricated 3013 containers. Significant cracking was observed in all containers in areas near welds and transitions in the container diameter. Stress corrosion cracks developed in both the lid and the body of gas tungsten arc welded and laser closure welded containers. The development of stress corrosion cracks in the as-fabricated and in the closure welded container samples demonstrates that the residual stresses in the 3013 containers are sufficient to support stress corrosion cracking if the environmental conditions inside the containers do not preclude the cracking process.

  2. A non-linear elastic constitutive framework for replicating plastic deformation in solids.

    SciTech Connect (OSTI)

    Roberts, Scott Alan; Schunk, Peter Randall

    2014-02-01

    Ductile metals and other materials typically deform plastically under large applied loads; a behavior most often modeled using plastic deformation constitutive models. However, it is possible to capture some of the key behaviors of plastic deformation using only the framework for nonlinear elastic mechanics. In this paper, we develop a phenomenological, hysteretic, nonlinear elastic constitutive model that captures many of the features expected of a plastic deformation model. This model is based on calculating a secant modulus directly from a material's stress-strain curve. Scalar stress and strain values are obtained in three dimensions by using the von Mises invariants. Hysteresis is incorporated by tracking an additional history variable and assuming an elastic unloading response. This model is demonstrated in both single- and multi-element simulations under varying strain conditions.

  3. Microelectromechanical systems contact stress sensor

    DOE Patents [OSTI]

    Kotovsky, Jack

    2007-12-25

    A microelectromechanical systems stress sensor comprising a microelectromechanical systems silicon body. A recess is formed in the silicon body. A silicon element extends into the recess. The silicon element has limited freedom of movement within the recess. An electrical circuit in the silicon element includes a piezoresistor material that allows for sensing changes in resistance that is proportional to bending of the silicon element.

  4. Status Report: Characterization of Weld Residual Stresses on...

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

    Status Report: Characterization of Weld Residual Stresses on Full Diameter SNF Interim ... and results of initial stress (and stress corrosion cracking, SCC) characterization work. ...

  5. Design method addresses subsea pipeline thermal stresses

    SciTech Connect (OSTI)

    Suman, J.C.; Karpathy, S.A. )

    1993-08-30

    Managing thermal stresses in subsea pipelines carrying heated petroleum requires extensive thermal-stress analysis to predict trouble spots and to ensure a design flexible enough to anticipate stresses and expansions. Explored here are various methods for resolving predicaments posed by thermal loads and resulting deformations by keeping the stresses and deformations in the pipeline system within allowable limits. The problems posed by thermal stresses are not unique; the solutions proposed here are. These methods are based on recent work performed for a major Asian subsea pipeline project currently under construction.

  6. Method for deriving information regarding stress from a stressed ferromagnetic material

    DOE Patents [OSTI]

    Jiles, David C.

    1991-04-30

    A non-destructive evaluation technique for deriving stress in ferromagnetic materials including deriving anhysteretic and hysteresis magnetization curves for the material in both unstressed and stressed states. The anhysteretic curve is expressed as a Langevin function. The stress is expressed as an equivalent magnetic field dependent on stress and change of magnetostriction with magnetization. By measurement of these bulk magnetic properties, stress can be derived.

  7. Method for deriving information regarding stress from a stressed ferromagnetic material

    DOE Patents [OSTI]

    Jiles, D.C.

    1991-04-30

    A nondestructive evaluation technique is disclosed for deriving stress in ferromagnetic materials including deriving anhysteretic and hysteresis magnetization curves for the material in both unstressed and stressed states. The anhysteretic curve is expressed as a Langevin function. The stress is expressed as an equivalent magnetic field dependent on stress and change of magnetostriction with magnetization. By measurement of these bulk magnetic properties, stress can be derived.

  8. Laboratory-based micro-X-ray fluorescence setup using a von Hamos crystal spectrometer and a focused beam X-ray tube

    SciTech Connect (OSTI)

    Kayser, Y.; B?achucki, W.; Dousse, J.-Cl.; Hoszowska, J.; Neff, M.; Romano, V.

    2014-04-15

    The high-resolution von Hamos bent crystal spectrometer of the University of Fribourg was upgraded with a focused X-ray beam source with the aim of performing micro-sized X-ray fluorescence (XRF) measurements in the laboratory. The focused X-ray beam source integrates a collimating optics mounted on a low-power micro-spot X-ray tube and a focusing polycapillary half-lens placed in front of the sample. The performances of the setup were probed in terms of spatial and energy resolution. In particular, the fluorescence intensity and energy resolution of the von Hamos spectrometer equipped with the novel micro-focused X-ray source and a standard high-power water-cooled X-ray tube were compared. The XRF analysis capability of the new setup was assessed by measuring the dopant distribution within the core of Er-doped SiO{sub 2} optical fibers.

  9. Thermoplastic deformation of silicon surfaces induced by ultrashort pulsed lasers in submelting conditions

    SciTech Connect (OSTI)

    Tsibidis, G. D.; Stratakis, E.; Aifantis, K. E.

    2012-03-01

    A hybrid theoretical model is presented to describe thermoplastic deformation effects on silicon surfaces induced by single and multiple ultrashort pulsed laser irradiation in submelting conditions. An approximation of the Boltzmann transport equation is adopted to describe the laser irradiation process. The evolution of the induced deformation field is described initially by adopting the differential equations of dynamic thermoelasticity while the onset of plastic yielding is described by the von Mises stress. Details of the resulting picometre sized crater, produced by irradiation with a single pulse, are discussed as a function of the imposed conditions and thresholds for the onset of plasticity are computed. Irradiation with multiple pulses leads to ripple formation of nanometre size that originates from the interference of the incident and a surface scattered wave. It is suggested that ultrafast laser induced surface modification in semiconductors is feasible in submelting conditions, and it may act as a precursor of the incubation effects observed at multiple pulse irradiation of materials surfaces.

  10. A Benchmark Study on Casting Residual Stress

    SciTech Connect (OSTI)

    Johnson, Eric M. [John Deere -- Moline Tech Center; Watkins, Thomas R [ORNL; Schmidlin, Joshua E [ORNL; Dutler, S. A. [MAGMA Foundry Technologies, Inc.

    2012-01-01

    Stringent regulatory requirements, such as Tier IV norms, have pushed the cast iron for automotive applications to its limit. The castings need to be designed with closer tolerances by incorporating hitherto unknowns, such as residual stresses arising due to thermal gradients, phase and microstructural changes during solidification phenomenon. Residual stresses were earlier neglected in the casting designs by incorporating large factors of safety. Experimental measurement of residual stress in a casting through neutron or X-ray diffraction, sectioning or hole drilling, magnetic, electric or photoelastic measurements is very difficult and time consuming exercise. A detailed multi-physics model, incorporating thermo-mechanical and phase transformation phenomenon, provides an attractive alternative to assess the residual stresses generated during casting. However, before relying on the simulation methodology, it is important to rigorously validate the prediction capability by comparing it to experimental measurements. In the present work, a benchmark study was undertaken for casting residual stress measurements through neutron diffraction, which was subsequently used to validate the accuracy of simulation prediction. The stress lattice specimen geometry was designed such that subsequent castings would generate adequate residual stresses during solidification and cooling, without any cracks. The residual stresses in the cast specimen were measured using neutron diffraction. Considering the difficulty in accessing the neutron diffraction facility, these measurements can be considered as benchmark for casting simulation validations. Simulations were performed using the identical specimen geometry and casting conditions for predictions of residual stresses. The simulation predictions were found to agree well with the experimentally measured residual stresses. The experimentally validated model can be subsequently used to predict residual stresses in different cast

  11. Stress in shaped glass evacuated collectors

    SciTech Connect (OSTI)

    Garrison, J.D.; Fischer-Cripps, A.

    1997-02-01

    Shaped glass evacuated collectors have the lower vacuum envelope formed with a CPC shape. The internal surface is silvered. This surface concentrates solar radiation onto an internal absorbing tube. The upper part of the vacuum envelope is a window to pass the solar radiation in to the absorbing tube. A computer program using analytical equations is used to design these collectors while keeping the glass tensile stress arising from evacuation below acceptable limits. A finite element computer program is used to test the accuracy of the stress calculated analytically. The calculations agree within about 1 MPa. Wind and thermal stresses in the glass are lower than the stresses caused by evacuation.

  12. Accelerated Stress Testing, Qualification Testing, HAST, Field...

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

    Accelerated Stress Testing, Qualification Testing, HAST, Field Experience This presentation, which was the opening session of the NREL 2013 Photovoltaic Module Reliability Workshop ...

  13. High temperature aqueous stress corrosion testing device

    DOE Patents [OSTI]

    Bornstein, A.N.; Indig, M.E.

    1975-12-01

    A description is given of a device for stressing tensile samples contained within a high temperature, high pressure aqueous environment, thereby permitting determination of stress corrosion susceptibility of materials in a simple way. The stressing device couples an external piston to an internal tensile sample via a pull rod, with stresses being applied to the sample by pressurizing the piston. The device contains a fitting/seal arrangement including Teflon and weld seals which allow sealing of the internal system pressure and the external piston pressure. The fitting/seal arrangement allows free movement of the pull rod and the piston.

  14. electrochemical battery stress-induced degradation mechanisms

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

    electrochemical battery stress-induced degradation mechanisms - Sandia Energy Energy ... Energy Storage Nuclear Power & Engineering Grid Modernization Battery Testing Nuclear Fuel ...

  15. Over Core Stress | Open Energy Information

    Open Energy Info (EERE)

    Analysis- Rock Over Core Stress Paleomagnetic Measurements Petrography Analysis Rock Density X-Ray Diffraction (XRD) X-Ray Fluorescence (XRF) References Page Area Activity Start...

  16. Optical stress generator and detector

    DOE Patents [OSTI]

    Maris, Humphrey J.; Stoner, Robert J

    2001-01-01

    Disclosed is a system for the characterization of thin films and interfaces between thin films through measurements of their mechanical and thermal properties. In the system light is absorbed in a thin film or in a structure made up of several thin films, and the change in optical transmission or reflection is measured and analyzed. The change in reflection or transmission is used to give information about the ultrasonic waves that are produced in the structure. The information that is obtained from the use of the measurement methods and apparatus of this invention can include: (a) a determination of the thickness of thin films with a speed and accuracy that is improved compared to earlier methods; (b) a determination of the thermal, elastic, and optical properties of thin films; (c) a determination of the stress in thin films; and (d) a characterization of the properties of interfaces, including the presence of roughness and defects.

  17. Optical stress generator and detector

    DOE Patents [OSTI]

    Maris, Humphrey J.; Stoner, Robert J.

    1998-01-01

    Disclosed is a system for the characterization of thin films and interfaces between thin films through measurements of their mechanical and thermal properties. In the system light is absorbed in a thin film or in a structure made up of several thin films, and the change in optical transmission or reflection is measured and analyzed. The change in reflection or transmission is used to give information about the ultrasonic waves that are produced in the structure. The information that is obtained from the use of the measurement methods and apparatus of this invention can include: (a) a determination of the thickness of thin films with a speed and accuracy that is improved compared to earlier methods; (b) a determination of the thermal, elastic, and optical properties of thin films; (c) a determination of the stress in thin films; and (d) a characterization of the properties of interfaces, including the presence of roughness and defects.

  18. Optical stress generator and detector

    DOE Patents [OSTI]

    Maris, Humphrey J.; Stoner, Robert J

    2002-01-01

    Disclosed is a system for the characterization of thin films and interfaces between thin films through measurements of their mechanical and thermal properties. In the system light is absorbed in a thin film or in a structure made up of several thin films, and the change in optical transmission or reflection is measured and analyzed. The change in reflection or transmission is used to give information about the ultrasonic waves that are produced in the structure. The information that is obtained from the use of the measurement methods and apparatus of this invention can include: (a) a determination of the thickness of thin films with a speed and accuracy that is improved compared to earlier methods; (b) a determination of the thermal, elastic, and optical properties of thin films; (c) a determination of the stress in thin films; and (d) a characterization of the properties of interfaces, including the presence of roughness and defects.

  19. Optical stress generator and detector

    DOE Patents [OSTI]

    Maris, Humphrey J.; Stoner, Robert J

    1999-01-01

    Disclosed is a system for the characterization of thin films and interfaces between thin films through measurements of their mechanical and thermal properties. In the system light is absorbed in a thin film or in a structure made up of several thin films, and the change in optical transmission or reflection is measured and analyzed. The change in reflection or transmission is used to give information about the ultrasonic waves that are produced in the structure. The information that is obtained from the use of the measurement methods and apparatus of this invention can include: (a) a determination of the thickness of thin films with a speed and accuracy that is improved compared to earlier methods; (b) a determination of the thermal, elastic, and optical properties of thin films; (c) a determination of the stress in thin films; and (d) a characterization of the properties of interfaces, including the presence of roughness and defects.

  20. Optical stress generator and detector

    DOE Patents [OSTI]

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

    1998-05-05

    Disclosed is a system for the characterization of thin films and interfaces between thin films through measurements of their mechanical and thermal properties. In the system light is absorbed in a thin film or in a structure made up of several thin films, and the change in optical transmission or reflection is measured and analyzed. The change in reflection or transmission is used to give information about the ultrasonic waves that are produced in the structure. The information that is obtained from the use of the measurement methods and apparatus of this invention can include: (a) a determination of the thickness of thin films with a speed and accuracy that is improved compared to earlier methods; (b) a determination of the thermal, elastic, and optical properties of thin films; (c) a determination of the stress in thin films; and (d) a characterization of the properties of interfaces, including the presence of roughness and defects. 32 figs.

  1. STRESS CORROSION CRACKING IN TEAR DROP SPECIMENS

    SciTech Connect (OSTI)

    Lam, P; Philip Zapp, P; Jonathan Duffey, J; Kerry Dunn, K

    2009-05-01

    Laboratory tests were conducted to investigate the stress corrosion cracking (SCC) of 304L stainless steel used to construct the containment vessels for the storage of plutonium-bearing materials. The tear drop corrosion specimens each with an autogenous weld in the center were placed in contact with moist plutonium oxide and chloride salt mixtures. Cracking was found in two of the specimens in the heat affected zone (HAZ) at the apex area. Finite element analysis was performed to simulate the specimen fabrication for determining the internal stress which caused SCC to occur. It was found that the tensile stress at the crack initiation site was about 30% lower than the highest stress which had been shifted to the shoulders of the specimen due to the specimen fabrication process. This finding appears to indicate that the SCC initiation took place in favor of the possibly weaker weld/base metal interface at a sufficiently high level of background stress. The base material, even subject to a higher tensile stress, was not cracked. The relieving of tensile stress due to SCC initiation and growth in the HAZ and the weld might have foreclosed the potential for cracking at the specimen shoulders where higher stress was found.

  2. Dynamic response of Cu4Zr54 metallic glass to high strain rate shock loading: plasticity, spall and atomic-level structures

    SciTech Connect (OSTI)

    Luo, Shengnian; Arman, Bedri; Germann, Timothy C; Cagin, Tahir

    2009-01-01

    We investigate dynamic response of Cu{sub 46}Zr{sub 54} metallic glass under adiabatic planar shock wave loading (one-dimensional strain) wjth molecular dynamics simulations, including Hugoniot (shock) states, shock-induced plasticity and spallation. The Hugoniot states are obtained up to 60 CPa along with the von Mises shear flow strengths, and the dynamic spall strength, at different strain rates and temperatures. The spall strengths likely represent the limiting values achievable in experiments such as laser ablation. For the steady shock states, a clear elastic-plastic transition is identified (e.g., in the shock velocity-particle velocity curve), and the shear strength shows strain-softening. However, the elastic-plastic transition across the shock front displays transient stress overshoot (hardening) above the Hugoniot elastic limit followed by a relatively sluggish relaxation to the steady shock state, and the plastic shock front steepens with increasing shock strength. The local von Mises shear strain analysis is used to characterize local deformation, and the Voronoi tessellation analysis, the corresponding short-range structures at various stages of shock, release, tension and spallation. The plasticity in this glass is manifested as localized shear transformation zones and of local structure rather than thermal origin, and void nucleation occurs preferentially at the highly shear-deformed regions. The Voronoi and shear strain analyses show that the atoms with different local structures are of different shear resistances that lead to shear localization (e.g., the atoms indexed with (0,0,12,0) are most shear-resistant, and those with (0,2,8,1) are highly prone to shear flow). The dynamic changes in local structures are consistent with the observed deformation dynamics.

  3. Understanding the Differences in Induced Stresses to Improve...

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

    Understanding the Differences in Induced Stresses to Improve Variation in Light Soak Response Understanding the Differences in Induced Stresses to Improve Variation in Light Soak ...

  4. Fuel Cell Tech Team Accelerated Stress Test and Polarization...

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

    Accelerated stress test and polarization curve protocols developed by the U.S. DRIVE Fuel ... Fuel Cell Tech Team Accelerated Stress Test and Polarization Curve Protocols for PEM ...

  5. Partial Shade Stress Test for Thin-Film Photovoltaic Modules...

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

    Partial Shade Stress Test for Thin-Film Photovoltaic Modules Preprint Timothy J. ... Partial shade stress test for thin-film photovoltaic modules Timothy J Silverman , ...

  6. Benefits of stress: Resolution of the Lifshitz singularity (Journal...

    Office of Scientific and Technical Information (OSTI)

    Benefits of stress: Resolution of the Lifshitz singularity Citation Details In-Document Search Title: Benefits of stress: Resolution of the Lifshitz singularity Authors: Bao, Ning ...

  7. Three dimensional stress vector sensor array and method therefor...

    Office of Scientific and Technical Information (OSTI)

    Three dimensional stress vector sensor array and method therefor Citation Details In-Document Search Title: Three dimensional stress vector sensor array and method therefor A ...

  8. Stress transfer during different deformation stages in anano...

    Office of Scientific and Technical Information (OSTI)

    Stress transfer during different deformation stages in a nano-precipitate-strengthened Ni-Ti shape memory alloy Citation Details In-Document Search Title: Stress transfer during ...

  9. Indentation Based Techniques to Measure Residual Stresses in...

    Office of Scientific and Technical Information (OSTI)

    to Measure Residual Stresses in Engineering Ceramics. Citation Details In-Document Search Title: Indentation Based Techniques to Measure Residual Stresses in Engineering Ceramics. ...

  10. Sandia Energy - BES Highlight: Stress-Induced NanoparticleCrystalliza...

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

    Highlight: Stress-Induced Nanoparticle Crystallization Home Highlights - Energy Research BES Highlight: Stress-Induced Nanoparticle Crystallization Previous Next BES Highlight:...

  11. Enhancing Plant Growth and Stress Tolerance through Use of Fungi...

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

    Enhancing Plant Growth and Stress Tolerance through Use of Fungi and Bacteria that Comprise Plant Microbiomes Enhancing Plant Growth and Stress Tolerance through Use of Fungi and ...

  12. Characterization of welding residual stresses with neutron diffraction

    SciTech Connect (OSTI)

    Wang, X.L.; Spooner, S.; Hubbard, C.R.; Taljat, B.; Feng, Z.

    1998-03-01

    Welding residual stresses are a key concern in the fabrication and use of structural components containing welds. Residual stresses in welds are caused by non-uniform expansion and shrinkage of differently heated zones during the thermal transient of a weld pass. In some alloys, solid state phase transformations occurring during the welding transient contribute additional residual stresses. Manufacturing problems arising from welding residual stresses include cracking and dimensional distortion. During use, tensile stresses in the welded zone limit the fatigue resistance of the component under cyclic loading. In an aggressive environment, tensile welding residual stresses also create a necessary condition for stress-corrosion cracking to take place.

  13. Stress corrosion cracking of Alloy 600. [PWR

    SciTech Connect (OSTI)

    Serra, E.

    1981-11-01

    The stress corrosion cracking of Alloy 600 tubing has affected the performance of several pressurized water reactor steam generators. The purpose of this report is to summarize the research which has followed that reviewed by D. van Rooyen in 1975. Although several papers and reports have been published there still is not a general model that can explain the stress corrosion cracking behavior of Alloy 600 in deaerated or aerated high-temperature pure water or in the environments that might exist in the primary and secondary coolant of a steam generator. Such a model, if it exists, must cover the complex interaction of the environmental, metallurgical, and mechanical variables which control the susceptibility of Alloy 600 to stress corrosion cracking. Each of these classes of variables is discussed in the text.

  14. System and method for measuring residual stress

    DOE Patents [OSTI]

    Prime, Michael B.

    2002-01-01

    The present invention is a method and system for determining the residual stress within an elastic object. In the method, an elastic object is cut along a path having a known configuration. The cut creates a portion of the object having a new free surface. The free surface then deforms to a contour which is different from the path. Next, the contour is measured to determine how much deformation has occurred across the new free surface. Points defining the contour are collected in an empirical data set. The portion of the object is then modeled in a computer simulator. The points in the empirical data set are entered into the computer simulator. The computer simulator then calculates the residual stress along the path which caused the points within the object to move to the positions measured in the empirical data set. The calculated residual stress is then presented in a useful format to an analyst.

  15. Stress- and Chemistry-Mediated Permeability Enhancement/Degradation in Stimulated Critically-Stressed Fractures

    SciTech Connect (OSTI)

    Derek Elsworth; Abraham S. Grader; Chris Marone; Phillip Halleck; Peter Rose; Igor Faoro; Joshua Taron; André Niemeijer; Hideaki Yasuhara

    2009-03-30

    This work has investigated the interactions between stress and chemistry in controlling the evolution of permeability in stimulated fractured reservoirs through an integrated program of experimentation and modeling. Flow-through experiments on natural and artificial fractures in Coso diorite have examined the evolution of permeability under paths of mean and deviatoric stresses, including the role of dissolution and precipitation. Models accommodating these behaviors have examined the importance of incorporating the complex couplings between stress and chemistry in examining the evolution of permeability in EGS reservoirs. This document reports the findings of experiment [1,2] and analysis [3,4], in four sequential chapters.

  16. Role of residual stresses in stress corrosion cracking in alloy 600 tubes. Part 1. Determination of throughwall residual stresses and their modification by transient heat treatment

    SciTech Connect (OSTI)

    Bandy, R.; Zemanian, T.

    1985-01-01

    The effect of transient heat treatment on throughwall residual stress distribution of cold worked Alloy 600 tubes has been investigated, using electrochemical machining coupled with Sachs analyses for residual stress calculations. Heating for 60 to 150 seconds at 775 to 850 C is used. Specimens are made from one highly cold worked and one lightly cold worked tube. In both cases significant reduction of the magnitude of the stress, and modification of the stress distribution are achieved as a result of the heat treatment. The percentage reduction of the magnitude of the stress caused by the same heat treatment is generally greater in the lightly cold worked tube than in the highly cold worked one. The implications of the stress relieving heat treatments to mitigating stress corrosion cracking in a specific case are discussed. 14 references, 17 figures, 1 table.

  17. Acrolein cytotoxicity in hepatocytes involves endoplasmic reticulum stress, mitochondrial dysfunction and oxidative stress

    SciTech Connect (OSTI)

    Mohammad, Mohammad K.; Alcohol Research Center, University of Louisville ; Avila, Diana; Department of Pharmacology and Toxicology, University of Louisville; Alcohol Research Center, University of Louisville ; Zhang, Jingwen; Alcohol Research Center, University of Louisville ; Barve, Shirish; Department of Pharmacology and Toxicology, University of Louisville; Alcohol Research Center, University of Louisville ; Arteel, Gavin; Alcohol Research Center, University of Louisville ; McClain, Craig; Department of Pharmacology and Toxicology, University of Louisville; Alcohol Research Center, University of Louisville; Robley Rex VAMC, Louisville, KY ; Joshi-Barve, Swati; Department of Pharmacology and Toxicology, University of Louisville; Alcohol Research Center, University of Louisville

    2012-11-15

    Acrolein is a common environmental, food and water pollutant and a major component of cigarette smoke. Also, it is produced endogenously via lipid peroxidation and cellular metabolism of certain amino acids and drugs. Acrolein is cytotoxic to many cell types including hepatocytes; however the mechanisms are not fully understood. We examined the molecular mechanisms underlying acrolein hepatotoxicity in primary human hepatocytes and hepatoma cells. Acrolein, at pathophysiological concentrations, caused a dose-dependent loss of viability of hepatocytes. The death was apoptotic at moderate and necrotic at high concentrations of acrolein. Acrolein exposure rapidly and dramatically decreased intracellular glutathione and overall antioxidant capacity, and activated the stress-signaling MAP-kinases JNK, p42/44 and p38. Our data demonstrate for the first time in human hepatocytes, that acrolein triggered endoplasmic reticulum (ER) stress and activated eIF2?, ATF-3 and -4, and Gadd153/CHOP, resulting in cell death. Notably, the protective/adaptive component of ER stress was not activated, and acrolein failed to up-regulate the protective ER-chaperones, GRP78 and GRP94. Additionally, exposure to acrolein disrupted mitochondrial integrity/function, and led to the release of pro-apoptotic proteins and ATP depletion. Acrolein-induced cell death was attenuated by N-acetyl cysteine, phenyl-butyric acid, and caspase and JNK inhibitors. Our data demonstrate that exposure to acrolein induces a variety of stress responses in hepatocytes, including GSH depletion, oxidative stress, mitochondrial dysfunction and ER stress (without ER-protective responses) which together contribute to acrolein toxicity. Our study defines basic mechanisms underlying liver injury caused by reactive aldehyde pollutants such as acrolein. -- Highlights: ? Human primary hepatocytes and cultured cell lines are used. ? Multiple cell death signaling pathways are activated by acrolein. ? Novel finding of acrolein

  18. Local residual stress monitoring of aluminum nitride MEMS using...

    Office of Scientific and Technical Information (OSTI)

    The AlN film stress shifted 400 MPa from regions where AlN was deposited over a bottom metal electrode versus silicon dioxide. Thus, across wafer stress variations were also ...

  19. Membrane and MEA Accelerated Stress Test Protocols | Department of Energy

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

    and MEA Accelerated Stress Test Protocols Membrane and MEA Accelerated Stress Test Protocols This presentation on fuel cell membrane and MEA stress test protocols was given by T. Benjamin at the High Temperature Membrane Working Group Meeting in May 2007. htmwg_benjamin.pdf (395.65 KB) More Documents & Publications HTMWG, May 18, 2009, Welcome! Automotive Perspective on PEM Evaluation Fuel Cell Tech Team Accelerated Stress Test and Polarization Curve Protocols for PEM Fuel Cells

  20. Shear wave transducer for stress measurements in boreholes

    DOE Patents [OSTI]

    Mao, Nai-Hsien

    1987-01-01

    A technique and apparatus for estimating in situ stresses by measuring stress-induced velocity anisotropy around a borehole. Two sets each of radially and tangentially polarized transducers are placed inside the hole with displacement directions either parallel or perpendicular to the principal stress directions. With this configuration, relative travel times are measured by both a pulsed phase-locked loop technique and a cross correlation of digitized waveforms. The biaxial velocity data is used to back-calculate the applied stress.

  1. Method For Characterizing Residual Stress In Metals

    DOE Patents [OSTI]

    Jacobson, Loren A.; Michel, David J.; Wyatt, Jeffrey R.

    2002-12-03

    A method is provided for measuring the residual stress in metals. The method includes the steps of drilling one or more holes in a metal workpiece to a preselected depth and mounting one or more acoustic sensors on the metal workpiece and connecting the sensors to an electronic detecting and recording device. A liquid metal capable of penetrating into the metal workpiece placed at the bottom of the hole or holes. A recording is made over a period of time (typically within about two hours) of the magnitude and number of noise events which occur as the liquid metal penetrates into the metal workpiece. The magnitude and number of noise events are then correlated to the internal stress in the region of the workpiece at the bottom of the hole.

  2. Liquid salt environment stress-rupture testing

    DOE Patents [OSTI]

    Ren, Weiju; Holcomb, David E.; Muralidharan, Govindarajan; Wilson, Dane F.

    2016-03-22

    Disclosed herein are systems, devices and methods for stress-rupture testing selected materials within a high-temperature liquid salt environment. Exemplary testing systems include a load train for holding a test specimen within a heated inert gas vessel. A thermal break included in the load train can thermally insulate a load cell positioned along the load train within the inert gas vessel. The test specimen can include a cylindrical gage portion having an internal void filled with a molten salt during stress-rupture testing. The gage portion can have an inner surface area to volume ratio of greater than 20 to maximize the corrosive effect of the molten salt on the specimen material during testing. Also disclosed are methods of making a salt ingot for placement within the test specimen.

  3. Compressive stress system for a gas turbine engine

    SciTech Connect (OSTI)

    Hogberg, Nicholas Alvin

    2015-03-24

    The present application provides a compressive stress system for a gas turbine engine. The compressive stress system may include a first bucket attached to a rotor, a second bucket attached to the rotor, the first and the second buckets defining a shank pocket therebetween, and a compressive stress spring positioned within the shank pocket.

  4. Tank waste remediation system heat stress control program report, 1995

    SciTech Connect (OSTI)

    Carls, D.R.

    1995-09-28

    Protecting employees from heat stress within tank farms during the summer months is challenging. Work constraints typically experienced in tank farms complicate the measures taken to protect employees from heat stress. TWRS-Industrial Hygiene (IH) has endeavored to control heat stress injuries by anticipating, recognizing, evaluating and controlling the factors which lead or contribute to heat stress in Tank Farms. The TWRS Heat Stress Control Program covers such areas as: employee and PIC training, communication of daily heat stress alerts to tank farm personnel, setting work/rest regimens, and the use of engineering and personal protective controls when applicable. The program has increased worker awareness of heat stress and prevention, established provisions for worker rest periods, increased drinking water availability to help ensure worker hydration, and allowed for the increased use of other protective controls to combat heat stress. The TWRS Heat Stress Control Program is the cornerstone for controlling heat stress among tank farm employees. The program has made great strides since it`s inception during the summer of 1994. Some improvements can still be made to enhance the program for the summer of 1996, such as: (1) procurement and use of personal heat stress monitoring equipment to ensure appropriate application of administrative controls, (2) decrease the need for use of containment tents and anti-contamination clothing, and (3) providing a wider variety of engineering and personal protective controls for heat stress prevention

  5. PNNL Stress/Strain Correlation for Zircaloy

    SciTech Connect (OSTI)

    Geelhood, Kenneth J.; Beyer, Carl E.; Luscher, Walter G.

    2008-07-18

    Pacific Northwest National Laboratory (PNNL) was tasked with incorporating cladding mechanical property data into the Nuclear Regulatory Commission (NRC) fuel codes, FRAPCON-31 and FRAPTRAN2, by the NRC Office of Nuclear Reactor Research. The objective of that task was to create a mechanical model that can calculate true stress, true strain, and the possible failure of the fuel rod cladding based on uniaxial test data.

  6. Stress Tolerant Plants Expressing Mannosylglcerate Enzymes - Energy

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

    Innovation Portal Stress Tolerant Plants Expressing Mannosylglcerate Enzymes Lawrence Berkeley National Laboratory Contact LBL About This Technology Technology Marketing SummaryHenrik Scheller of the Joint BioEnergy Institute (JBEI) and researchers from the University of Copenhagen and Aarhus University have identified genes in eukaryotes encoding mannosylglycerate synthases. Mannosylglycerate, a thermoprotectant compound, had been thought to occur only in archaea and eubacteria.

  7. Method and apparatus for measuring stress

    DOE Patents [OSTI]

    Thompson, R. Bruce

    1985-06-11

    A method and apparatus for determining stress in a material independent of micro-structural variations and anisotropies. The method comprises comparing the velocities of two horizontally polarized and horizontally propagating ultrasonic shear waves with interchanged directions of propagation and polarization. The apparatus for carrying out the method comprises periodic permanent magnet-electromagnetic acoustic transducers for generating and detecting the shear waves and means for determining the wave velocities.

  8. Method and apparatus for measuring stress

    DOE Patents [OSTI]

    Thompson, R.B.

    1983-07-28

    A method and apparatus for determining stress in a material independent of micro-structural variations and anisotropies. The method comprises comparing the velocities of two horizontally polarized and horizontally propagating ultrasonic shear waves with interchanged directions of propagation and polarization. The apparatus for carrying out the method comprises periodic permanent magnet-electromagnetic acoustic transducers for generating and detecting the shear waves and means for determining the wave velocities.

  9. Lamins as mediators of oxidative stress

    SciTech Connect (OSTI)

    Sieprath, Tom; Darwiche, Rabih; De Vos, Winnok H.

    2012-05-18

    Highlights: Black-Right-Pointing-Pointer The nuclear lamina defines structural and functional properties of the cell nucleus. Black-Right-Pointing-Pointer Lamina dysfunction leads to a broad spectrum of laminopathies. Black-Right-Pointing-Pointer Recent data is reviewed connecting laminopathies to oxidative stress. Black-Right-Pointing-Pointer A framework is proposed to explain interactions between lamins and oxidative stress. -- Abstract: The nuclear lamina defines both structural and functional properties of the eukaryotic cell nucleus. Mutations in the LMNA gene, encoding A-type lamins, lead to a broad spectrum of diseases termed laminopathies. While different hypotheses have been postulated to explain disease development, there is still no unified view on the mechanistic basis of laminopathies. Recent observations indicate that laminopathies are often accompanied by altered levels of reactive oxygen species and a higher susceptibility to oxidative stress at the cellular level. In this review, we highlight the role of reactive oxygen species for cell function and disease development in the context of laminopathies and present a framework of non-exclusive mechanisms to explain the reciprocal interactions between a dysfunctional lamina and altered redox homeostasis.

  10. Municipal solid waste effective stress analysis

    SciTech Connect (OSTI)

    Shariatmadari, Nader; Machado, Sandro Lemos; Noorzad, Ali; Karimpour-Fard, Mehran

    2009-12-15

    The mechanical behavior of municipal solid waste (MSW) has attracted the attention of many researchers in the field of geo-environmental engineering in recent years and several aspects of waste mechanical response under loading have been elucidated. However, the mechanical response of MSW materials under undrained conditions has not been described in detail to date. The knowledge of this aspect of the MSW mechanical response is very important in cases involving MSW with high water contents, seismic ground motion and in regions where landfills are built with poor operation conditions. This paper presents the results obtained from 26 large triaxial tests performed both in drained and undrained conditions. The results were analyzed taking into account the waste particles compressibility and the deformation anisotropy of the waste samples. The waste particles compressibility was used to modify the Terzaghi effective stress equation, using the Skempton (1961) proposition. It is shown that the use of the modified effective stress equation led to much more compatible shear strength values when comparing Consolidated-Drained (CD) and Consolidated-Undrained (CU), results, explaining the high shear strength values obtained in CU triaxial tests, even when the pore pressure is almost equal to the confining stress.

  11. Triaxial Stress Distributions in Cu / low-k Interconnect Features

    SciTech Connect (OSTI)

    C Murray; P Besser; E Ryan; J Jordan-Sweet

    2011-12-31

    The distribution of triaxial stresses within single damascene Cu/organosilicate interconnect structures as a function of linewidth, ranging from 45 to 250 nm, was measured using x-ray diffraction. Least-squares minimization techniques were employed to determine the volume-averaged stress tensors of the Cu features. Longitudinal Cu stress values increased for linewidths below 100 nm, while transverse stresses decreased with decreasing linewidth below 100 nm due to the interplay between the Cu microstructure and the feature geometry. Large tensile out-of-plane stresses were observed in all of the lines demonstrating the constraint imposed by the barrier layers that encapsulate the Cu.

  12. Integrity assessment of the ferritic / austenitic dissimilar weld joint between intermediate heat exchanger and steam generator in fast reactor

    SciTech Connect (OSTI)

    Jayakumar, T.; Laha, K.; Chandravathi, K. S.; Parameswaran, P.; Goyal, S.; Kumar, J. G.; Mathew, M. D.

    2012-07-01

    Integrity of the modified 9Cr-1Mo / alloy 800 dissimilar joint welded with Inconel 182 electrodes has been assessed under creep condition based on the detailed analysis of microstructure and stress distribution across the joint by finite element analysis. A hardness peak at the ferritic / austenitic weld interface and a hardness trough at the inter-critical heat affected zone (HAZ) in ferritic base metal developed. Un-tempered martensite was found at the ferritic / austenitic weld interface to impart high hardness in it; whereas annealing of martensitic structure of modified 9Cr-1Mo steel by inter-critical heating during welding thermal cycle resulted in hardness tough in the inter-critical HAZ. Creep tests were carried out on the joint and ferritic steel base metal at 823 K over a stress range of 160-320 MPa. The joint possessed lower creep rupture strength than its ferritic steel base metal. Failure of the joint at relatively lower stresses occurred at the ferritic / austenitic weld interface; whereas it occurred at inter-critical region of HAZ at moderate stresses. Cavity nucleation associated with the weld interface particles led to premature failure of the joint. Finite element analysis of stress distribution across the weld joint considering the micro-mechanical strength inhomogeneity across it revealed higher von-Mises and principal stresses at the weld interface. These stresses induced preferential creep cavitation at the weld interface. Role of precipitate in enhancing creep cavitation at the weld interface has been elucidated based on the FE analysis of stress distribution across it. (authors)

  13. Anisotropic stress correlations in two-dimensional liquids

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wu, Bin; Iwashita, Takuya; Egami, Takeshi

    2015-03-01

    In this paper we demonstrate the presence of anisotropic stress correlations in the simulated 2D liquids. Whereas the temporal correlation of macroscopic shear stress is known to contribute to viscosity via the Green-Kubo formula, the general question regarding angular dependence of the spatial correlation among atomic level stresses in liquids without external shear has not been explored. Besides the apparent anisotropicity with well-defined symmetry, we found that the characteristic length of shear stress correlation depends on temperature and follows the power law, suggesting divergence around the glass transition temperature. The anisotropy of the stress correlations can be explained in termsmore » of the inclusion model by Eshelby, based upon which we suggest that the mismatch between the atom and its nearest neighbor cage produces the atomic level stress as well as the long-range stress fields.« less

  14. Anisotropic stress correlations in two-dimensional liquids

    SciTech Connect (OSTI)

    Wu, Bin; Iwashita, Takuya; Egami, Takeshi

    2015-03-01

    In this paper we demonstrate the presence of anisotropic stress correlations in the simulated 2D liquids. Whereas the temporal correlation of macroscopic shear stress is known to contribute to viscosity via the Green-Kubo formula, the general question regarding angular dependence of the spatial correlation among atomic level stresses in liquids without external shear has not been explored. Besides the apparent anisotropicity with well-defined symmetry, we found that the characteristic length of shear stress correlation depends on temperature and follows the power law, suggesting divergence around the glass transition temperature. The anisotropy of the stress correlations can be explained in terms of the inclusion model by Eshelby, based upon which we suggest that the mismatch between the atom and its nearest neighbor cage produces the atomic level stress as well as the long-range stress fields.

  15. Impact produced stress waves in composites

    SciTech Connect (OSTI)

    Clements, B.; Johnson, J.; Addessio, F.; Hixson, R.

    1997-05-01

    The Nonhomogenized Dynamic Method of Cells (NHDMOC) is used to study the propagation of stress waves through laminates. The accuracy of the theory is tested by applying it to a plate-impact experiment and checking its ability to resolve a propagation shock wave front. The theory is then compared to Lagrangian hydrodynamic calculations, where it is found that the NHDMOC consistently requires less fine spatial and temporal grids, and less artificial viscosity to control numerical noise. The theory is then used to treat the impact of an epoxy-graphite bilaminate. When the viscoelastic properties of the epoxy are accounted for, the theory agrees well with the experiment.

  16. FEA stress analysis for SAFKEG 2863B

    SciTech Connect (OSTI)

    Puckett, A.

    1997-07-15

    This report covers the evaluation of the structural design of the two stainless steel containment vessels in CROFT SAFKEG Model Number 2863B, for conformance to the design criteria of the NRC Regulatory Guide 7.6, NRC Regulatory Guide 7.8, and the applicable requirements of the ASME Boiler and Pressure Vessel Code, Section 3, and Section 8. The two containment vessels are designated Cans 2870 and 2871. Each of these containment vessels was analyzed for the loadings specified in chapter 2, Section 2.1.2 of the SARP. Structural assessment of Cans 2870 and 2871 due to loading considerations beyond the evaluation of pressure and temperature are presented. This report is organized as follows: (1) overview of the design of each containment vessel and pressure boundary; (2) brief description of both containment vessels; (3) discussion of normal and accident conditions; (4) analysis assumptions; (5) detailed structural evaluation of each component of each containment vessel; (6) demonstration of compliance to Regulatory Guide 7.6 stress evaluations; (7) demonstration of compliance to Regulatory Guide 7.8 loading combinations; and (8) summary of the calculated stresses, comparison with design allowables, estimates of margins of safety and a summary of results and conclusions.

  17. Stress-Assisted Corrosion in Boiler Tubes

    SciTech Connect (OSTI)

    Preet M Singh; Steven J Pawel

    2006-05-27

    A number of industrial boilers, including in the pulp and paper industry, needed to replace their lower furnace tubes or decommission many recovery boilers due to stress-assisted corrosion (SAC) on the waterside of boiler tubes. More than half of the power and recovery boilers that have been inspected reveal SAC damage, which portends significant energy and economic impacts. The goal of this project was to clarify the mechanism of stress-assisted corrosion (SAC) of boiler tubes for the purpose of determining key parameters in its mitigation and control. To accomplish this in-situ strain measurements on boiler tubes were made. Boiler water environment was simulated in the laboratory and effects of water chemistry on SAC initiation and growth were evaluated in terms of industrial operations. Results from this project have shown that the dissolved oxygen is single most important factor in SAC initiation on carbon steel samples. Control of dissolved oxygen can be used to mitigate SAC in industrial boilers. Results have also shown that sharp corrosion fatigue and bulbous SAC cracks have similar mechanism but the morphology is different due to availability of oxygen during boiler shutdown conditions. Results are described in the final technical report.

  18. Spherical nanoindentation stressstrain curves

    SciTech Connect (OSTI)

    Pathak, Siddhartha; Kalidindi, Surya R.

    2015-03-24

    Although indentation experiments have long been used to measure the hardness and Young's modulus, the utility of this technique in analyzing the complete elasticplastic response of materials under contact loading has only been realized in the past few years mostly due to recent advances in testing equipment and analysis protocols. This paper provides a timely review of the recent progress made in this respect in extracting meaningful indentation stressstrain curves from the raw datasets measured in instrumented spherical nanoindentation experiments. These indentation stressstrain curves have produced highly reliable estimates of the indentation modulus and the indentation yield strength in the sample, as well as certain aspects of their post-yield behavior, and have been critically validated through numerical simulations using finite element models as well as direct in situ scanning electron microscopy (SEM) measurements on micro-pillars. Much of this recent progress was made possible through the introduction of a new measure of indentation strain and the development of new protocols to locate the effective zero-point of initial contact between the indenter and the sample in the measured datasets. As a result, this has led to an important key advance in this field where it is now possible to reliably identify and analyze the initial loading segment in the indentation experiments.

  19. Stress enhanced diffusion of krypton ions in polycrystalline titanium

    SciTech Connect (OSTI)

    Nsengiyumva, S.; Raji, A. T.; Rivière, J. P.; Britton, D. T.; Härting, M.

    2014-07-14

    An experimental investigation on the mutual influence of pre-existing residual stress and point defect following ion implantation is presented. The study has been carried out using polycrystalline titanium samples energetically implanted with krypton ions at different fluences. Ion beam analysis was used to determine the concentration profile of the injected krypton ions, while synchrotron X-ray diffraction has been used for stress determination. Ion beam analysis and synchrotron X-ray diffraction stress profile measurements of the implanted titanium samples show a clear evidence of stress-enhanced diffusion of krypton ions in titanium. It is further observed that for the titanium samples implanted at low fluence, ion implantation modifies the pre-existing residual stress through the introduction of point and open volume defects. The stress fields resulting from the ion implantation act to drift the krypton inclusions towards the surface of titanium.

  20. Assessment of the Mechanical Stress Improvement Process for Mitigating Primary Water Stress Corrosion Cracking in Nickel Alloy Butt Welds in Piping Systems Approved for Leak-Before-Break

    SciTech Connect (OSTI)

    Sullivan, Edmund J.; Anderson, Michael T.

    2013-01-01

    This report provides an assessment of the use of Mechanical Stress Improvement Process to reduce, or decrease, stress-driven degradation, i.e., primary water stress corrosion cracking.

  1. Sulfide stress cracking resistance of nitrogen-strengthened stainless steel

    SciTech Connect (OSTI)

    Gaugh, R.R.

    1981-01-01

    The paper describes sulfide stress cracking tests performed on a number of these alloys. Most were found to be somewhat susceptible to cracking, depending on the stress level. It was determined that this was due to their high manganese content. The mechanism responsible for cracking was not firmly established. One commercial nitrogen-strengthened stainless steel, XM19, was highly resistant to sulfide stress cracking despite a manganese content of 5%. This difference is attributed to the superior corrosion resistance of the alloy.

  2. Secretary Chu Stresses Global Cooperation on Energy, Economic and Climate

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

    Challenges in Talks with World Energy Ministers | Department of Energy Stresses Global Cooperation on Energy, Economic and Climate Challenges in Talks with World Energy Ministers Secretary Chu Stresses Global Cooperation on Energy, Economic and Climate Challenges in Talks with World Energy Ministers March 13, 2009 - 12:00am Addthis Washington, DC - In recent discussions with a broad range of world energy ministers, U.S. Energy Secretary Steven Chu has stressed the need for global cooperation

  3. 2014 JASON Report: State of Stress in Engineered Subsurface Systems |

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

    Department of Energy 4 JASON Report: State of Stress in Engineered Subsurface Systems 2014 JASON Report: State of Stress in Engineered Subsurface Systems September 26, 2014 - 12:04pm Addthis JASON study members stand on a basaltic dike exposure below the La Jolla cliffs while professor Yuri Fialko of the Scripps Institution of Oceanography (back left) describes how its orientation is controlled by the stress field at the time of emplacement. Credit: Benjamin Phillips JASON study members

  4. Understanding the Differences in Induced Stresses to Improve Variation in

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

    Light Soak Response | Department of Energy Understanding the Differences in Induced Stresses to Improve Variation in Light Soak Response Understanding the Differences in Induced Stresses to Improve Variation in Light Soak Response Presented at the PV Module Reliability Workshop, February 26 - 27 2013, Golden, Colorado pvmrw13_ps1_firstsolar_sorensen.pdf (1.34 MB) More Documents & Publications 2011 TEPP Annual Report Understanding the Differences in Induced Stresses to Improve Variation

  5. Sources of stress gradients in electrodeposited Ni MEMS. (Conference...

    Office of Scientific and Technical Information (OSTI)

    Title: Sources of stress gradients in electrodeposited Ni MEMS. The ability of future integrated metal-semiconductor micro-systems such as RF MEMS to perform highly complex ...

  6. Stress-dependent permeability of fractured rock masses: A numerical...

    Office of Scientific and Technical Information (OSTI)

    permeability of fractured rock masses: A numerical study Citation Details In-Document Search Title: Stress-dependent permeability of fractured rock masses: A numerical study We ...

  7. Fractured rock stress-permeability relationships from in situ...

    Office of Scientific and Technical Information (OSTI)

    Fractured rock stress-permeability relationships from in situ data and effects of temperature and chemical-mechanical couplings Citation Details In-Document Search Title: Fractured...

  8. Tensile-stressed microelectromechanical apparatus and micromirrors formed therefrom

    DOE Patents [OSTI]

    Fleming, James G. (Albuquerque, NM)

    2006-05-16

    A microelectromechanical (MEM) apparatus is disclosed which includes one or more tensile-stressed actuators that are coupled through flexures to a stage on a substrate. The tensile-stressed actuators, which can be formed from tensile-stressed tungsten or silicon nitride, initially raise the stage above the substrate without any applied electrical voltage, and can then be used to control the height or tilt angle of the stage. An electrostatic actuator can also be used in combination with each tensile-stressed actuator. The MEM apparatus has applications for forming piston micromirrors or tiltable micromirrors and independently addressable arrays of such devices.

  9. Measuring depth profiles of residual stress with Raman spectroscopy

    SciTech Connect (OSTI)

    Enloe, W.S.; Sparks, R.G.; Paesler, M.A.

    1988-12-01

    Knowledge of the variation of residual stress is a very important factor in understanding the properties of machined surfaces. The nature of the residual stress can determine a part`s susceptibility to wear deformation, and cracking. Raman spectroscopy is known to be a very useful technique for measuring residual stress in many materials. These measurements are routinely made with a lateral resolution of 1{mu}m and an accuracy of 0.1 kbar. The variation of stress with depth; however, has not received much attention in the past. A novel technique has been developed that allows quantitative measurement of the variation of the residual stress with depth with an accuracy of 10nm in the z direction. Qualitative techniques for determining whether the stress is varying with depth are presented. It is also demonstrated that when the stress is changing over the volume sampled, errors can be introduced if the variation of the stress with depth is ignored. Computer aided data analysis is used to determine the depth dependence of the residual stress.

  10. Accelerated Stress Test and Polarization Curve Protocols for...

    Office of Environmental Management (EM)

    Team Cell Component Accelerated Stress Test and Polarization Curve Protocols for PEM ... This document describes test protocols to assess the performance and durability of fuel ...

  11. Simulation of Distortion and Residual Stress Development During...

    Office of Scientific and Technical Information (OSTI)

    Simulation of Distortion and Residual Stress Development During Heat Treatment of Steel ... Available experimental steel casting heat treatment data was determined to be of ...

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

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

    Three established mechanical test specimen geometries and test methods for brittle materials are adapted to DPF architecture to evaluate failure initiation stress and apparent ...

  13. Systems biology analysis of Zymomonas mobilis ZM4 ethanol stress...

    Office of Scientific and Technical Information (OSTI)

    Systems biology analysis of Zymomonas mobilis ZM4 ethanol stress responses Citation Details In-Document Search Title: Systems biology analysis of Zymomonas mobilis ZM4 ethanol ...

  14. Thin Silicon MEMS Contact-Stress Sensor Kotovksy, J; Tooker,...

    Office of Scientific and Technical Information (OSTI)

    A; Horsley, D 42 ENGINEERING; 42 ENGINEERING; ACCURACY; ACTUATORS; SILICON This thin, MEMS contact-stress sensor continuously and accurately measures time-varying, solid...

  15. Thin Silicon MEMS Contact-Stress Sensor Kotovsky, J; Tooker,...

    Office of Scientific and Technical Information (OSTI)

    ACCURACY; ACTUATORS; CALIBRATION; DIAPHRAGM; SILICON; STABILITY; THICKNESS This thin, MEMS contact-stress (CS) sensor continuously and accurately measures time-varying, solid...

  16. Thin Silicon MEMS Contact-Stress Sensor Kotovsky, J; Tooker,...

    Office of Scientific and Technical Information (OSTI)

    LIFETIME; PACKAGING; PERFORMANCE; SILICON; THICKNESS This work offers the first, thin, MEMS contact-stress (CS) sensor capable of accurate in situ measruement of time-varying,...

  17. Deduction and Analysis of the Interacting Stress Response Pathways...

    Office of Scientific and Technical Information (OSTI)

    Deduction and Analysis of the Interacting Stress Response Pathways of MetalRadionuclide-reducing Bacteria Citation Details In-Document Search Title: Deduction and Analysis of the ...

  18. Thermal Stress and Reliability for Advanced Power Electronics...

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

    Thermal Performance and Reliability of Bonded Interfaces Physics of Failure of Electrical Interconnects Thermal Stress and Reliability for Advanced Power Electronics and Electric ...

  19. A luminescent nanocrystal stress gauge (Journal Article) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Details In-Document Search Title: A luminescent nanocrystal stress gauge Microscale mechanical forces can determine important outcomes ranging from the site of material...

  20. Experimental measurement of stress at a four-domain junction...

    Office of Scientific and Technical Information (OSTI)

    patterns in the transmission electron microscope. ... Analysis of the data showed that large stresses were ... TRANSMISSION ELECTRON MICROSCOPY Word Cloud More Like ...

  1. Stress Test At Coso Geothermal Area (2004) | Open Energy Information

    Open Energy Info (EERE)

    Test At Coso Geothermal Area (2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Stress Test At Coso Geothermal Area (2004) Exploration...

  2. Stress analysis and evaluation of a rectangular pressure vessel...

    Office of Scientific and Technical Information (OSTI)

    States)) 42 ENGINEERING; 12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES; PRESSURE VESSELS; STRESS ANALYSIS; RADIOACTIVE WASTE STORAGE;...

  3. Evaluation of crystallinity and film stress in yttria-stabilized...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Evaluation of crystallinity and film stress in yttria-stabilized zirconia thin films Citation Details In-Document Search Title: Evaluation of crystallinity and ...

  4. Microseismicity, stress, and fracture in the Coso geothermal...

    Open Energy Info (EERE)

    Microseismicity, stress, and fracture in the Coso geothermal field, California Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Microseismicity,...

  5. Overcoming residual stresses and machining distortion in the...

    Office of Scientific and Technical Information (OSTI)

    in the production of aluminum alloy satellite boxes. Citation Details In-Document Search Title: Overcoming residual stresses and machining distortion in the production of ...

  6. RESIDUAL STRESSES IN ADDITIVELY MANUFACTURED INCONEL 718 ENGINE...

    Office of Scientific and Technical Information (OSTI)

    Title: RESIDUAL STRESSES IN ADDITIVELY MANUFACTURED INCONEL 718 ENGINE MOUNT Authors: Watkins, Thomas R 1 ; Cornwell, Paris A 1 ; Dehoff, Ryan R 1 ; Nangia, Vinod 2 ; ...

  7. Stress evolution during growth in direct-current-sputtered zinc...

    Office of Scientific and Technical Information (OSTI)

    Country of Publication: United States Language: English Subject: 36 MATERIALS SCIENCE; CRYSTAL GROWTH; DIRECT CURRENT; FLOW STRESS; OXYGEN; OXYGEN IONS; RADIOWAVE RADIATION; ...

  8. Three dimensional stress vector sensor array and method therefor

    DOE Patents [OSTI]

    Pfeifer, Kent Bryant; Rudnick, Thomas Jeffery

    2005-07-05

    A sensor array is configured based upon capacitive sensor techniques to measure stresses at various positions in a sheet simultaneously and allow a stress map to be obtained in near real-time. The device consists of single capacitive elements applied in a one or two dimensional array to measure the distribution of stresses across a mat surface in real-time as a function of position for manufacturing and test applications. In-plane and normal stresses in rolling bodies such as tires may thus be monitored.

  9. Residual Stresses for Structural Analysis and Fatigue Life Prediction...

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

    Life Prediction in Vehicle Components: Success stories from the High Temperature Materials Laboratory (HTML) User Program Residual Stresses for Structural Analysis and Fatigue Life ...

  10. Thermal Stress and Reliability for Advanced Power Electronics...

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

    Thermal Stress and Reliability for Advanced Power Electronics and Electric Machines Power Electronic Thermal System Performance and Integration Thermal Performance and Reliability ...

  11. The origins of growth stresses in amorphous semiconductor thin...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: The origins of growth stresses in amorphous semiconductor thin films. Citation Details In-Document ... Publication Date: 2003-03-01 OSTI Identifier: 917484 Report ...

  12. P wave anisotropy, stress, and crack distribution at Coso geothermal...

    Open Energy Info (EERE)

    scalar. The resulting anisotropy distribution is used to estimate variations in crack density, stress distribution and permeability within the producing geothermal field. A...

  13. Coupled thermal stress simulations of ductile tearing

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Neilsen, Michael K.; Dion, Kristin

    2016-03-01

    Predictions for ductile tearing of a geometrically complex Ti-6Al-4V plate were generated using a Unified Creep Plasticity Damage model in fully coupled thermal stress simulations. Uniaxial tension and butterfly shear tests performed at displacement rates of 0.0254 and 25.4 mm/s were also simulated. Results from these simulations revealed that the material temperature increase due to plastic work can have a dramatic effect on material ductility predictions in materials that exhibit little strain hardening. Furthermore, this occurs because the temperature increase causes the apparent hardening of the material to decrease which leads to the initiation of deformation localization and subsequent ductilemore » tearing earlier in the loading process.« less

  14. Adjustable shear stress erosion and transport flume

    DOE Patents [OSTI]

    Roberts, Jesse D.; Jepsen, Richard A.

    2002-01-01

    A method and apparatus for measuring the total erosion rate and downstream transport of suspended and bedload sediments using an adjustable shear stress erosion and transport (ASSET) flume with a variable-depth sediment core sample. Water is forced past a variable-depth sediment core sample in a closed channel, eroding sediments, and introducing suspended and bedload sediments into the flow stream. The core sample is continuously pushed into the flow stream, while keeping the surface level with the bottom of the channel. Eroded bedload sediments are transported downstream and then gravitationally separated from the flow stream into one or more quiescent traps. The captured bedload sediments (particles and aggregates) are weighed and compared to the total mass of sediment eroded, and also to the concentration of sediments suspended in the flow stream.

  15. Plastic cap evolution law derived from induced transverse isotropy in dilatational triaxial compression.

    SciTech Connect (OSTI)

    Macon, David James; Brannon, Rebecca Moss; Strack, Otto Eric

    2014-02-01

    Mechanical testing of porous materials generates physical data that contain contributions from more than one underlying physical phenomenon. All that is measurable is the (3z(Bensemble(3y (Bhardening modulus. This thesis is concerned with the phenomenon of dilatation in triaxial compression of porous media, which has been modeled very accurately in the literature for monotonic loading using models that predict dilatation under triaxial compression (TXC) by presuming that dilatation causes the cap to move outwards. These existing models, however, predict a counter-intuitive (and never validated) increase in hydrostatic compression strength. This work explores an alternative approach for modeling TXC dilatation based on allowing induced elastic anisotropy (which makes the material both less stiff and less strong in the lateral direction) with no increase in hydrostatic strength. Induced elastic anisotropy is introduced through the use of a distortion operator. This operator is a fourth-order tensor consisting of a combination of the undeformed stiffness and deformed compliance and has the same eigenprojectors as the elastic compliance. In the undeformed state, the distortion operator is equal to the fourth-order identity. Through the use of the distortion operator, an evolved stress tensor is introduced. When the evolved stress tensor is substituted into an isotropic yield function, a new anisotropic yield function results. In the case of the von Mises isotropic yield function (which contains only deviatoric components), it is shown that the distortion operator introduces a dilatational contribution without requiring an increase in hydrostatic strength. In the thesis, an introduction and literature review of the cap function is given. A transversely isotropic compliance is presented, based on a linear combination of natural bases constructed about a transverse-symmetry axis. Using a probabilistic distribution of cracks constructed for the case of transverse isotropy

  16. Thermoplastic Response in Anisotr Rock

    Energy Science and Technology Software Center (OSTI)

    1998-10-14

    UTAH-2 is a two-dimensional, thermomechanical finite element program designed to analyze elastic, elastic-plastic, and elastic brittle response in anisotropic geologic media. Both constant strain triangles and quadrilateral elements composed of four constant strain trangles are used. The yield function for either elastic-plastic or elastic-brittle response is an extended von Mises criteria for the yield function considers the effects of confining pressure. UTAH-2 is able to consider temperature dependence of material properties. The elastic and plasticmore » moduli as well as the thermal expansion coefficients can vary with temperature based on a polynomial fit of experimental data. UTAH-2 is intended for use in analyzing stress and displacement fields associated with repository excavation, canister emplacement, salt over short time periods and in other geological media for any time scale; for evaluating room stability and generating boundary conditions (stress fields) used in canister sleeve studies; for analyzing bedded sedimentary regions; and for sensitivity and stability studies where temperature dependence of material properties may be a factor.« less

  17. Characterization of Optical Fiber Strength Under Applied Tensile Stress and Bending Stress

    SciTech Connect (OSTI)

    P.E. Klingsporn

    2011-08-01

    Various types of tensile testing and bend radius tests were conducted on silica core/silica cladding optical fiber of different diameters with different protective buffer coatings, fabricated by different fiber manufacturers. The tensile tests were conducted to determine not only the average fiber strengths at failure, but also the distribution in fracture strengths, as well as the influence of buffer coating on fracture strength. The times-to-failure of fiber subjected to constant applied bending stresses of various magnitudes were measured to provide a database from which failure times of 20 years or more, and the corresponding minimum bend radius, could be extrapolated in a statistically meaningful way. The overall study was done to provide an understanding of optical fiber strength in tensile loading and in applied bending stress as related to applications of optical fiber in various potential coizfgurations for weapons and enhanced surveillance campaigns.

  18. Materials for coal gasification. Effect of environment on stress rupture

    SciTech Connect (OSTI)

    Horton, R.M.

    1980-01-01

    The biaxial stress rupture behavior for two of the alloys, Type 310 stainless steel and Haynes 188, is shown in figures. The other two alloys show similar behavior. The rupture parameter, P, is an empirical quantity which reflects the simultaneous effects of both temperature and duration of applied stress on stress rupture. Based on these results, several trends are apparent: (1) the biaxial stress rupture tests show the same trends and approximately the same stress rupture values as uniaxial data obtained from the literature for each alloy tested; (2) only for the Haynes 188 may the stress rupture strength/life in CGA have been significantly less than in air. But further testing has indicated there is probably no reduction of biaxial stress rupture strength/life in CGA even for this alloy; (3) the biaxial strain at rupture was small, typically only a few percent. It is appropriate to mention that in the uniaxial stress rupture testing at SwRI, exposure to CGA generally resulted in a shorter rupture life than with testing in air. No explanation is yet available for the observed difference in behavior between SwRI and INEL test specimens.

  19. Stress-enhanced swelling of metal during irradiation

    SciTech Connect (OSTI)

    Garner, F.A.; Gilbert, E.R.; Porter, D.L.

    1980-04-01

    Data are available which show that stress plays a major role in the development of radiation-induced void growth in AISI 316 and many other alloys. Earlier experiments came to the opposite conclusion and are shown to have investigated stress levels which inadvertantly cold-worked the material. Stress-affected swelling spans the entire temperature range in fast reactor irradiations and accelerates with increasing irradiatin temperature. It also appears to operate in all alloy starting conditions investigated. Two major microstructural mechanisms appear to be causing the enhancement of swelling, which for tensile stresses is manifested primarily as a decrease in the incubation period. These mechanisms are stress-induced changes in the interstitial capture efficiency of voids and stress-induced changes in the vacancy emission rate of various microstructural components. There also appears to be an enhancement of intermetallic phase formation with applied stress and this is shown to increase swelling by accelerating the microchemical evolution that precedes void growth at high temperature. This latter consideration complicates the extrapolation of these data to compressive stress states.

  20. Researchers Devise New Stress Test for Irradiated Materials

    Broader source: Energy.gov [DOE]

    How do you tell if materials are stressed-out? Conventional stress tests for irradiated materials require a significant amount of material, but a new nano-size technique can test the strength of materials using an infinitesimal amount. Learn more.

  1. Predicting Thermal Stress in Diesel Particulate Filters | Department of

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

    Energy Thermal Stress in Diesel Particulate Filters Predicting Thermal Stress in Diesel Particulate Filters 2004 Diesel Engine Emissions Reduction (DEER) Conference Presentation: Corning Incorporated 2004_deer_wilcox.pdf (224.39 KB) More Documents & Publications Diesel Emission Control Review Substrate Studies of an Electrically-Assisted Diesel Particulate Filter Electrically-Assisted Diesel Particulate Filter Regeneration

  2. Thermoacoustic method for relaxation of residual stresses in welded joints

    SciTech Connect (OSTI)

    Koshovyi, V.V.; Pakhn`o, M.I.; Tsykhan, O.I.

    1995-01-01

    We propose a thermoacoustic method for the relaxation of residual stresses in welded joints, present a block diagram of a generator of local thermoacoustic pulses designed for implementation of this method, and describe our experiment aimed at relaxation of residual tensile stresses.

  3. Oxidative stress-induced autophagy: Role in pulmonary toxicity

    SciTech Connect (OSTI)

    Malaviya, Rama; Laskin, Jeffrey D.; Laskin, Debra L.

    2014-03-01

    Autophagy is an evolutionarily conserved catabolic process important in regulating the turnover of essential proteins and in elimination of damaged organelles and protein aggregates. Autophagy is observed in the lung in response to oxidative stress generated as a consequence of exposure to environmental toxicants. Whether autophagy plays role in promoting cell survival or cytotoxicity is unclear. In this article recent findings on oxidative stress-induced autophagy in the lung are reviewed; potential mechanisms initiating autophagy are also discussed. A better understanding of autophagy and its role in pulmonary toxicity may lead to the development of new strategies to treat lung injury associated with oxidative stress. - Highlights: • Exposure to pulmonary toxicants is associated with oxidative stress. • Oxidative stress is known to induce autophagy. • Autophagy is upregulated in the lung following exposure to pulmonary toxicants. • Autophagy may be protective or pathogenic.

  4. Residual stress within nanoscale metallic multilayer systems during thermal cycling

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Economy, David Ross; Cordill, Megan Jo; Payzant, E. Andrew; Kennedy, Marian S.

    2015-09-21

    Projected applications for nanoscale metallic multilayers will include wide temperature ranges. Since film residual stress has been known to alter system reliability, stress development within new film structures with high interfacial densities should be characterized to identify potential long-term performance barriers. To understand factors contributing to thermal stress evolution within nanoscale metallic multilayers, stress in Cu/Nb systems adhered to Si substrates was calculated from curvature measurements collected during cycling between 25 °C and 400 °C. Additionally, stress within each type of component layers was calculated from shifts in the primary peak position from in-situ heated X-ray diffraction. The effects ofmore » both film architecture (layer thickness) and layer order in metallic multilayers were tracked and compared with monolithic Cu and Nb films. Analysis indicated that the thermoelastic slope of nanoscale metallic multilayer films depends on thermal expansion mismatch, elastic modulus of the components, and also interfacial density. The layer thickness (i.e. interfacial density) affected thermoelastic slope magnitude while layer order had minimal impact on stress responses after the initial thermal cycle. When comparing stress responses of monolithic Cu and Nb films to those of the Cu/Nb systems, the nanoscale metallic multilayers show a similar increase in stress above 200 °C to the Nb monolithic films, indicating that Nb components play a larger role in stress development than Cu. Local stress calculations from X-ray diffraction peak shifts collected during heating reveal that the component layers within a multilayer film respond similarly to their monolithic counterparts.« less

  5. Residual stress within nanoscale metallic multilayer systems during thermal cycling

    SciTech Connect (OSTI)

    Economy, David Ross; Cordill, Megan Jo; Payzant, E. Andrew; Kennedy, Marian S.

    2015-09-21

    Projected applications for nanoscale metallic multilayers will include wide temperature ranges. Since film residual stress has been known to alter system reliability, stress development within new film structures with high interfacial densities should be characterized to identify potential long-term performance barriers. To understand factors contributing to thermal stress evolution within nanoscale metallic multilayers, stress in Cu/Nb systems adhered to Si substrates was calculated from curvature measurements collected during cycling between 25 °C and 400 °C. Additionally, stress within each type of component layers was calculated from shifts in the primary peak position from in-situ heated X-ray diffraction. The effects of both film architecture (layer thickness) and layer order in metallic multilayers were tracked and compared with monolithic Cu and Nb films. Analysis indicated that the thermoelastic slope of nanoscale metallic multilayer films depends on thermal expansion mismatch, elastic modulus of the components, and also interfacial density. The layer thickness (i.e. interfacial density) affected thermoelastic slope magnitude while layer order had minimal impact on stress responses after the initial thermal cycle. When comparing stress responses of monolithic Cu and Nb films to those of the Cu/Nb systems, the nanoscale metallic multilayers show a similar increase in stress above 200 °C to the Nb monolithic films, indicating that Nb components play a larger role in stress development than Cu. Local stress calculations from X-ray diffraction peak shifts collected during heating reveal that the component layers within a multilayer film respond similarly to their monolithic counterparts.

  6. Method to adjust multilayer film stress induced deformation of optics

    DOE Patents [OSTI]

    Spiller, Eberhard A.; Mirkarimi, Paul B.; Montcalm, Claude; Bajt, Sasa; Folta, James A.

    2000-01-01

    Stress compensating systems that reduces/compensates stress in a multilayer without loss in reflectivity, while reducing total film thickness compared to the earlier buffer-layer approach. The stress free multilayer systems contain multilayer systems with two different material combinations of opposite stress, where both systems give good reflectivity at the design wavelengths. The main advantage of the multilayer system design is that stress reduction does not require the deposition of any additional layers, as in the buffer layer approach. If the optical performance of the two systems at the design wavelength differ, the system with the poorer performance is deposited first, and then the system with better performance last, thus forming the top of the multilayer system. The components for the stress reducing layer are chosen among materials that have opposite stress to that of the preferred multilayer reflecting stack and simultaneously have optical constants that allow one to get good reflectivity at the design wavelength. For a wavelength of 13.4 nm, the wavelength presently used for extreme ultraviolet (EUV) lithography, Si and Be have practically the same optical constants, but the Mo/Si multilayer has opposite stress than the Mo/Be multilayer. Multilayer systems of these materials have practically identical reflectivity curves. For example, stress free multilayers can be formed on a substrate using Mo/Be multilayers in the bottom of the stack and Mo/Si multilayers at the top of the stack, with the switch-over point selected to obtain zero stress. In this multilayer system, the switch-over point is at about the half point of the total thickness of the stack, and for the Mo/Be--Mo/Si system, there may be 25 deposition periods Mo/Be to 20 deposition periods Mo/Si.

  7. Lipocalin 2 regulation by thermal stresses: Protective role of Lcn2/NGAL against cold and heat stresses

    SciTech Connect (OSTI)

    Roudkenar, Mehryar Habibi, E-mail: roudkenar@ibto.ir [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Halabian, Raheleh [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of)] [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Roushandeh, Amaneh Mohammadi [Department of Anatomy, Faculty of Medicine, Medical University of Tabriz, Tabriz (Iran, Islamic Republic of)] [Department of Anatomy, Faculty of Medicine, Medical University of Tabriz, Tabriz (Iran, Islamic Republic of); Nourani, Mohammad Reza [Chemical Injury Research Center, Baqiyatallah Medical Science University, Tehran (Iran, Islamic Republic of)] [Chemical Injury Research Center, Baqiyatallah Medical Science University, Tehran (Iran, Islamic Republic of); Masroori, Nasser [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of)] [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Ebrahimi, Majid [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of) [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Chemical Injury Research Center, Baqiyatallah Medical Science University, Tehran (Iran, Islamic Republic of); Nikogoftar, Mahin; Rouhbakhsh, Mehdi; Bahmani, Parisa [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of)] [Research Center, Iranian Blood Transfusion Organization, Tehran (Iran, Islamic Republic of); Najafabadi, Ali Jahanian [Department of Molecular Biology, Pasteur Institute of Iran, Tehran (Iran, Islamic Republic of)] [Department of Molecular Biology, Pasteur Institute of Iran, Tehran (Iran, Islamic Republic of); Shokrgozar, Mohammad Ali [National Cell Bank of Iran, Pasteur institute of Iran, Tehran (Iran, Islamic Republic of)] [National Cell Bank of Iran, Pasteur institute of Iran, Tehran (Iran, Islamic Republic of)

    2009-11-01

    Environmental temperature variations are the most common stresses experienced by a wide range of organisms. Lipocalin 2 (Lcn2/NGAL) is expressed in various normal and pathologic conditions. However, its precise functions have not been fully determined. Here we report the induction of Lcn2 by thermal stresses in vivo, and its role following exposure to cold and heat stresses in vitro. Induction of Lcn2 in liver, heart and kidney was detected by RT-PCR, Western blot and immunohistochemistry following exposure of mice to heat and cold stresses. When CHO and HEK293T cells overexpressing NGAL were exposed to cold stress, cell proliferation was higher compared to controls. Down-regulatrion of NGAL by siRNA in A549 cells resulted in less proliferation when exposed to cold stress compared to control cells. The number of apoptotic cells and expression of pro-apoptotic proteins were lower in the NGAL overexpressing CHO and HEK293T cells, but were higher in the siRNA-transfected A549 cells compared to controls, indicating that NGAL protects cells against cold stress. Following exposure of the cells to heat stress, ectopic expression of NGAL protected cells while addition of exogenous recombinant NGAL to the cell culture medium exacerbated the toxicity of heat stress specially when there was low or no endogenous expression of NGAL. It had a dual effect on apoptosis following heat stress. NGAL also increased the expression of HO-1. Lcn2/NGAL may have the potential to improve cell proliferation and preservation particularly to prevent cold ischemia injury of transplanted organs or for treatment of some cancers by hyperthermia.

  8. Critical stress criteria for interfacial cavitation in MMCs

    SciTech Connect (OSTI)

    Whitehouse, A.F.; Clyne, T.W.

    1995-05-01

    Density measurements and microstructural examinations have been used to follow the formation, growth and coalescence of cavities during tensile loading of metal matrix composites (MMCs). Finite element modeling has been used to predict the stress states around reinforcements of various shapes. The positions of peak hydrostatic and normal stress components at the interface have been compared with the microstructural sites where voids were found to form experimentally in aluminum reinforced with alumina particles or fibers. It is concluded that cavities form when a critical hydrostatic stress is reached.

  9. Tensile-stressed microelectromechanical apparatus and tiltable micromirrors formed therefrom

    DOE Patents [OSTI]

    Fleming, James G.

    2007-01-09

    A microelectromechanical (MEM) apparatus is disclosed which includes a pair of tensile-stressed actuators suspending a platform above a substrate to tilt the platform relative to the substrate. A tensile stress built into the actuators initially tilts the platform when a sacrificial material used in fabrication of the MEM apparatus is removed. Further tilting of the platform can occur with a change in the ambient temperature about the MEM apparatus, or by applying a voltage to one or both of the tensile-stressed actuators. The MEM apparatus can be used to form a tiltable micromirror or an array of such devices, and also has applications for thermal management within satellites.

  10. Manipulating Stress in Cu/low-k Dielectric Nanocomposites

    SciTech Connect (OSTI)

    C Murray; P Besser; E Ryan; J Jordan-Sweet

    2011-12-31

    The interaction of x-rays with organic dielectric materials, which alters their mechanical properties, affects values of stress generated within encapsulated Cu structures. In particular, the evolution of stress within submicron Cu interconnect structures encapsulated by an organosilicate glass can be investigated in situ using synchrotron-based x-ray diffraction. The overall geometry of the composite, along with the amount of irradiation, dictates the change in stress of the Cu features. A quantitative comparison of these findings to mechanical modeling results reveals two modes of modification within the dielectric film: a densification that changes the effective eigenstrain followed by an increase in elastic modulus.

  11. Over Core Stress At Gabbs Valley Area (DOE GTP) | Open Energy...

    Open Energy Info (EERE)

    Stress At Gabbs Valley Area (DOE GTP) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Over Core Stress At Gabbs Valley Area (DOE GTP) Exploration...

  12. Thermal-stress modeling of an optical microphone at high temperature...

    Office of Scientific and Technical Information (OSTI)

    Thermal-stress modeling of an optical microphone at high temperature. Citation Details In-Document Search Title: Thermal-stress modeling of an optical microphone at high ...

  13. Structure, tectonics and stress field of the Coso Range, Inyo...

    Open Energy Info (EERE)

    tectonics and stress field of the Coso Range, Inyo County, California Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Structure, tectonics and...

  14. STRESS AND FAULTING IN THE COSO GEOTHERMAL FIELD: UPDATE AND...

    Open Energy Info (EERE)

    STRESS AND FAULTING IN THE COSO GEOTHERMAL FIELD: UPDATE AND RECENT RESULTS FROM THE EAST FLANK AND COSO WASH Jump to: navigation, search OpenEI Reference LibraryAdd to library...

  15. Residual stresses and plastic deformation in GTA-welded steel

    SciTech Connect (OSTI)

    Brand, P.C. ); Keijser, T.H. de; Ouden, G. den )

    1993-03-01

    Residual stresses and plastic deformation in single pass GTA welded low-carbon steel were studied by means of x-ray diffraction in combination with optical microscopy and hardness measurements. The residual stresses and the amount of plastic deformation (microstrain) were obtained from x-ray diffraction line positions and line broading. Since the plates were polished before welding, it was possible to observe in the optical microscope two types of Lueders bands. During heating curved Lueders bands and during cooling straight Lueders bands perpendicular to the weld are formed. The curved Lueders bands extend over a larger distance from the weld than the straight Lueders bands. The amount of plastic deformation as obtained from the x-ray diffraction analysis is in agreement with these observations. An explanation is offered for the stresses measured in combination with plastic deformations observed. It is concluded that in the present experiments plastic deformation is the main cause of the residual stresses.

  16. Seismicity and seismic stress in the Coso Range, Coso geothermal...

    Open Energy Info (EERE)

    and seismic stress in the Coso Range, Coso geothermal field, and Indian Wells Valley region, Southeast-Central California Jump to: navigation, search OpenEI Reference LibraryAdd to...

  17. Telemetric heat stress monitor (THSM) spin-offs

    SciTech Connect (OSTI)

    Berkbigler, L.; Bradley, O.; Lopez, R.; Martinez, D.; Stampfer, J.

    1996-07-01

    This is the final report of a one-year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). This project sought to investigate spin-offs of the telemetric heat stress monitoring system (THSM) developed at LANL. Hazardous-materials workers and firefighters wear clothing that protects them from external hazards, but the sealed environment of a protective suit makes its wearer susceptible to heat stress. Heat stress occurs when the body`s natural cooling mechanisms fail: it can cause collapse and death. The THSM warns both workers and remote monitoring personnel of incipient heat stress by monitoring and responding to elevations of workers` skin temperatures and heart rates. The technology won a 1994 R & D 100 award.

  18. Predicting stress-induced velocity anisotropy in rocks

    SciTech Connect (OSTI)

    Mavko, G.; Mukerji, T.; Godfrey, N.

    1995-07-01

    A simple transformation, using measured isotropic V{sub P} and V{sub S} versus hydrostatic pressure, is presented for predicting stress-induced seismic velocity anisotropy in rocks. The compliant, crack-like portions of the pore space are characterized by generalized compressional and shear compliances that are estimated form the isotropic V{sub P} and V{sub S}. The physical assumption that the compliant porosity is crack-like means that the pressure dependence of the generalized compliances is governed primarily by normal tractions resolved across cracks and defects. This allows the measured pressure dependence to be mapped form the hydrostatic stress state to any applied nonhydrostatic stress. Predicted P- and S-wave velocities agree reasonably well with uniaxial stress data for Barre Granite and Massillon Sandstone. While it is mechanically similar to methods based on idealized ellipsoidal cracks, the approach is relatively independent of any assumed crack geometry and is not limited to small crack densities.

  19. OSS 19.8 Heat Stress 4/3/95

    Broader source: Energy.gov [DOE]

    The objective of this surveillance is to evaluate the effectiveness of actions taken by the contractor to protect workers from the effects of heat stress.  The Facility Representative will observe...

  20. Petascale Simulations of Stress Corrosion Cracking | Argonne Leadership

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

    Computing Facility 240 Million Year: 2013 Research Domain: Materials Science Corrosion is a complex technological and economic problem with an annual cost of about 3% of the nation's gross domestic product. The performance and lifetime of materials widely used in energy and nuclear technologies are often limited by corrosion under stress loads. Simulations performed at the Argonne Leadership Computing Facility are revealing the atomistic mechanisms that control stress-induced corrosion

  1. Method for residual stress relief and retained austenite destabilization

    DOE Patents [OSTI]

    Ludtka, Gerard M.

    2004-08-10

    A method using of a magnetic field to affect residual stress relief or phase transformations in a metallic material is disclosed. In a first aspect of the method, residual stress relief of a material is achieved at ambient temperatures by placing the material in a magnetic field. In a second aspect of the method, retained austenite stabilization is reversed in a ferrous alloy by applying a magnetic field to the alloy at ambient temperatures.

  2. Residual stresses in weld overlay tubes: A finite element study

    SciTech Connect (OSTI)

    Taljat, B.; Zacharia, T.; Wang, X.L.; Keiser, J.R.; Feng, Z.; Jirinec, M.J.

    1997-01-03

    Residual stresses and strains in a tube with circumferential weld overlay were analyzed by the finite element (FE) method. The objective of this work was to develop and verify a FE model, to determine the magnitude and distribution of residual stresses in the weld overlay tube, and to evaluate the significance of two contributing factors to residual stress: (1) difference in material properties between tube and weld material, and (2) thermal gradients in the weld. An axisymmetric FE model was developed to simulate the circumferential two-layer welding process of alloy 625 overlay on SA210 tube. The first layer was modeled as a gas metal arc welding process with filler metal, whereas the autogenous gas tungsten arc welding process was modeled for the second layer. Neutron diffraction technique was used to experimentally determine residual elastic strains in the weld overlay tube. Comparison with the FE results shows overall good agreement. Both the experimental and FE results show high compressive stresses at the inside tube surface and high tensile stresses in the weld overlay. This suggests that weld overlay may be used to relieve tensile or produce compressive stresses at the inside tube surface, which is significant for applications where crack initiation is found at the root pass of the joining weld.

  3. Method to adjust multilayer film stress induced deformation of optics

    DOE Patents [OSTI]

    Mirkarimi, Paul B.; Montcalm, Claude

    2000-01-01

    A buffer-layer located between a substrate and a multilayer for counteracting stress in the multilayer. Depositing a buffer-layer having a stress of sufficient magnitude and opposite in sign reduces or cancels out deformation in the substrate due to the stress in the multilayer. By providing a buffer-layer between the substrate and the multilayer, a tunable, near-zero net stress results, and hence results in little or no deformation of the substrate, such as an optic for an extreme ultraviolet (EUV) lithography tool. Buffer-layers have been deposited, for example, between Mo/Si and Mo/Be multilayer films and their associated substrate reducing significantly the stress, wherein the magnitude of the stress is less than 100 MPa and respectively near-normal incidence (5.degree.) reflectance of over 60% is obtained at 13.4 nm and 11.4 nm. The present invention is applicable to crystalline and non-crystalline materials, and can be used at ambient temperatures.

  4. Mise-A-La-Masse Mapping of the HGP-A Geothermal Reservoir, Hawaii...

    Open Energy Info (EERE)

    confine geothermal fluids at depth. Authors James Kauahikaua, Mark Mattice and Dallas Jackson Conference GRC Annual Meeting; unknown; 19800901 Published Geothermal Resources...

  5. DC Resistivity Survey (Mise-A-La-Masse) At Roosevelt Hot Springs...

    Open Energy Info (EERE)

    Area. References S. H. Ward, W. T. Parry, W. P. Nash, W. R. Sill, K. L. Cook, R. B. Smith, D. S. Chapman, F. H. Brown, J. A. Whelan, J. R. Bowman (1978) A Summary of the...

  6. Extensile cracking in porous rock under differential compressive stress

    SciTech Connect (OSTI)

    Myer, L.R.; Kemeny, J.M.; Zheng, Z.

    1992-08-01

    Under differential compressive stress rocks exhibit nonlinear deformation that includes initial compaction, near-linear elastic behavior, and strain-hardening followed by strain-softening and dilation (or compaction in clastic rocks) and localization. This behavior derives largely from changes in the microstructure of the rocks. Much of it has been attributed to the growth of extensile microcracks. The stress-induced microstructural changes brought about by successively more complicated states of stress produced by uniaxial and triaxial compression of circular cylinders, axisymmetric stresses in hollow cylinders, and indentation by hemispheres in Indiana limestone and Berea sandstone have been preserved using Wood`s metal porosimetry. In this technique molten Wood`s metal at about 100{degrees}C is used as a pore fluid at a pressure of about 10 MPa, and the experiments are conducted using the concepts of effective stress. At the deformation state of interest, the temperature is lowered to solidify the metal, thereby preserving the microstructure as it exists under load and facilitating subsequent preparation of the specimen for microscopic study. Mode I microcrack growth is observed to occur by a variety of mechanisms such as bending, point loading and sliding cracks. The effects of this are analyzed using an elastic continuum within which Mode II displacement across microcracks and Mode I microcrack growth results from heterogeneous stress concentrations that produce local tensile stresses. While the continuum model replicates many of the observations, it fails to account for localization by en echelon arrays of extensile microcracks that precede macroscopic shear faulting. Using a {open_quotes}zero order{close_quotes} continuum approximation, the spatially stochastic distribution of grains in clastic rocks is shown to be important in the formation of the en echelon arrays of microcracks that form shear bands. 63 refs., 26 figs., 1 tab.

  7. Influence of target structure on film stress in WTi sputtering

    SciTech Connect (OSTI)

    Lo, C.F.; Wang, H.; Gilman, P.

    1998-12-31

    In this report, the effect of sputtering target microstructure on the deposited film stress was investigated. By controlling the metallurgical process, two types of W-10wt%Ti target constituents, namely single-phase and multiple-phase WTi, were prepared. The former one was composed of W-rich ({beta}Ti,W) phase only, the latter one was with W, W-rich ({beta}Ti,W) and Ti-rich ({beta}Ti,W) phases. The stress of the films deposited on 12.7 cm diameter silicon oxide wafers from the single-phase target tends to be more compressive than that from the multiple-phase target. By increasing wafer temperature, the compressive stress was linearly decreased. In addition, the level of film stress was also affected by the film thickness and other sputtering parameters. To understand the causes for the differences in film stress between the multiple-phase and single-phase derived films, an evaluation of the film structure using a field-emission scanning electron microscope (FE-SEM) and mechanical testing using a nano-indentation instrument were performed. Finer domains with denser laminar structure were observed on the films deposited from the single-phase target. However, no significant difference in mechanical properties was found between these two from the nano-indentation measurements. It is envisioned that the more uniform solid solution between the W and Ti in the films obtained by sputtering the single-phase targets generates a higher compressive stress when deposited on the silicon oxide wafers resulting in a higher compressive stress.

  8. Salt Stress in Desulfovibrio vulgaris Hildenborough: An integratedgenomics approach

    SciTech Connect (OSTI)

    Mukhopadhyay, Aindrila; He, Zhili; Alm, Eric J.; Arkin, Adam P.; Baidoo, Edward E.; Borglin, Sharon C.; Chen, Wenqiong; Hazen, Terry C.; He, Qiang; Holman, Hoi-Ying; Huang, Katherine; Huang, Rick; Hoyner,Dominique C.; Katz, Natalie; Keller, Martin; Oeller, Paul; Redding,Alyssa; Sun, Jun; Wall, Judy; Wei, Jing; Yang, Zamin; Yen, Huei-Che; Zhou, Jizhong; Keasling Jay D.

    2005-12-08

    The ability of Desulfovibrio vulgaris Hildenborough to reduce, and therefore contain, toxic and radioactive metal waste has made all factors that affect the physiology of this organism of great interest. Increased salinity is an important and frequent fluctuation faced by D. vulgaris in its natural habitat. In liquid culture, exposure to excess salt resulted in striking elongation of D. vulgaris cells. Using data from transcriptomics, proteomics, metabolite assays, phospholipid fatty acid profiling, and electron microscopy, we used a systems approach to explore the effects of excess NaCl on D. vulgaris. In this study we demonstrated that import of osmoprotectants, such as glycine betaine and ectoine, is the primary mechanism used by D. vulgaris to counter hyperionic stress. Several efflux systems were also highly up-regulated, as was the ATP synthesis pathway. Increases in the levels of both RNA and DNA helicases suggested that salt stress affected the stability of nucleic acid base pairing. An overall increase in the level of branched fatty acids indicated that there were changes in cell wall fluidity. The immediate response to salt stress included up-regulation of chemotaxis genes, although flagellar biosynthesis was down-regulated. Other down-regulated systems included lactate uptake permeases and ABC transport systems. The results of an extensive NaCl stress analysis were compared with microarray data from a KCl stress analysis, and unlike many other bacteria, D. vulgaris responded similarly to the two stresses. Integration of data from multiple methods allowed us to develop a conceptual model for the salt stress response in D. vulgaris that can be compared to those in other microorganisms.

  9. Defining coiled tubing limits -- A new approach

    SciTech Connect (OSTI)

    Newman, K.R.; Sathuvalli, U.B.; Stone, L.R.; Wolhart, S.

    1996-12-31

    The burst, collapse and axial load operating limits for Coiled Tubing (CT) are currently established using the Von Mises incipient yield criterion. This criterion has historically been used to calculate the limits for oil country tubular goods (OCTG). The limits according to this criterion are based on the point at which the pipe material reaches a load state in which it begins to yield. Because of the bending that occurs when the CT is spooled on and off the reel, and when it is bent over the guide arch, the CT is already far beyond the yield point before it enters a well. Thus, this criterion does not really apply to CT. This paper describes a research project currently in progress. The purpose of this project is to define a new set of CT limits based on criteria other than incipient yield. This new approach to setting CT operating limits takes into account the internal residual stresses in the CT which are a consequence of repeated bending cycles and the accompanying change in material properties.

  10. Tensile residual stress fields produced in austenitic alloy weldments

    SciTech Connect (OSTI)

    Hornbach, D.J.; Prevey, P.S.

    1997-07-01

    Residual stresses developed by prior machining and welding may either accelerate or retard stress corrosion cracking (SCC), austenitic alloys, depending upon their magnitude and sign. A combined x-ray diffraction (XRD) and mechanical technique was used to determine the axial and hoop residual stress and yield strength distributions into the inside diameter surface of a simulated Alloy 600 penetration J-welded into a reactor pressure vessel. The degree of cold working and the resulting yield strength increase caused by prior machining and weld shrinkage was calculated from the line broadening distributions. Tension as high as +700 MPa was observed in both the axial and hoop directions at the inside diameter adjacent to the weld heat affected zone (HAZ). Stresses exceeding the bulk yield strength develop due to the combined effects of cold working of the surface layers during initial machining, and subsequent weld shrinkage. Cold working produced by prior machining was found to influence the final residual stress state developed by welding.

  11. Static-stress analysis of dual-axis confinement vessel

    SciTech Connect (OSTI)

    Bultman, D.H.

    1992-11-01

    This study evaluates the static-pressure containment capability of a 6-ft-diameter, spherical vessel, made of HSLA-100 steel, to be used for high-explosive (HE) containment. The confinement vessel is designed for use with the Dual-Axis Radiographic Hydrotest Facility (DARHT) being developed at Los Alamos National Laboratory. Two sets of openings in the vessel are covered with x-ray transparent covers to allow radiographic imaging of an explosion as it occurs inside the vessel. The confinement vessel is analyzed as a pressure vessel based on the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, and the Welding Research Council Bulletin, WRC-107. Combined stresses resulting from internal pressure and external loads on nozzles are calculated and compared with the allowable stresses for HSLA-100 steel. Results confirm that the shell and nozzles of the confinement vessel are adequately designed to safely contain the maximum residual pressure of 1675 psi that would result from an HE charge of 24.2 kg detonated in a vacuum. Shell stresses at the shell-to-nozzle interface, produced from external loads on the nozzles, were less than 400 psi. The maximum combined stress resulting from the internal pressure plus external loads was 16,070 psi, which is less than half the allowable stress of 42,375 psi for HSLA-100 steel.

  12. Static-stress analysis of dual-axis safety vessel

    SciTech Connect (OSTI)

    Bultman, D.H.

    1992-11-01

    An 8-ft-diameter safety vessel, made of HSLA-100 steel, is evaluated to determine its ability to contain the quasi-static residual pressure from a high-explosive (HE) blast. The safety vessel is designed for use with the Dual-Axis Radiographic Hydrotest (DARHT) facility being developed at Los Alamos National Laboratory. A smaller confinement vessel fits inside the safety vessel and contains the actual explosion, and the safety vessel functions as a second layer of containment in the unlikely case of a confinement vessel leak. The safety vessel is analyzed as a pressure vessel based on the ASME Boiler and Pressure Vessel Code, Section VIII, Division 1, and the Welding Research Council Bulletin, WRC107. Combined stresses that result from internal pressure and external loads on nozzles are calculated and compared to the allowable stresses for HSLA-100 steel. Results confirm that the shell and nozzle components are adequately designed for a static pressure of 830 psi, plus the maximum expected external loads. Shell stresses at the shellto-nozzle interface, produced from external loads on the nozzles, were less than 700 psi. The maximum combined stress resulting from the internal pressure plus external loads was 17,384 psi, which is significantly less than the allowable stress of 42,375 psi for HSLA-100 steel.

  13. ZPPR FUEL ELEMENT THERMAL STRESS-STRAIN ANALYSIS

    SciTech Connect (OSTI)

    Charles W. Solbrig; Jason Andrus; Chad Pope

    2014-04-01

    The design temperature of high plutonium concentration ZPPR fuel assemblies is 600 degrees C. Cladding integrity of the 304L stainless steel cladding is a significant concern with this fuel since even small holes can lead to substantial fuel degradation. Since the fuel has a higher coefficient of thermal expansion than the cladding, an investigation of the stress induced in the cladding due to the differential thermal expansion of fuel and cladding up to the design temperature was conducted. Small holes in the cladding envelope would be expected to lead to the fuel hydriding and oxidizing into a powder over a long period of time. This is the same type of chemical reaction chain that exists in the degradion of the high uranium concentration ZPPR fuel. Unfortunately, the uranium fuel was designed with vents which allowed this degradation to occur. The Pu cladding is sealed so only fuel with damaged cladding would be subject to this damage. The thermal stresses that can be developed in the fuel cladding have been calculated in in this paper and compared to the ultimate tensile stress of the cladding. The conclusion is drawn that thermal stresses cannot induce holes in the cladding even for the highest storage temperatures predicted in calculations (292C). In fact, thermal stress can not cause cladding failure as long as the fuel temperatures are below the design limit of 600 degrees C (1,112 degrees F).

  14. Effects of bending stresses and tube curvature on remote field eddy current signals

    SciTech Connect (OSTI)

    Sutherland, J.; Atherton, D.L.

    1997-01-01

    The effects of bending stresses and tube curvature on remote field eddy current signals were investigated. This technique is a recognized method for the nondestructive evaluation of ferromagnetic tubing, as used in heat exchangers and boiler systems. Different stress states were examined (elastic stress, plastic deformation, and residual stress) and found to give distinctive behavior. Elastic and residual stresses can appear as wall loss, depending on the operating frequency and baseline used for inspection and interpretation.

  15. Tensile-stressed microelectromechanical apparatus and microelectromechanical relay formed therefrom

    DOE Patents [OSTI]

    Fleming, James G.

    2008-03-04

    A microelectromechanical (MEM) apparatus is disclosed which includes a shuttle suspended above a substrate by two or more sets of tensile-stressed beams which are operatively connected to the shuttle and which can comprise tungsten or a silicon nitride/polysilicon composite structure. Initially, the tensile stress in each set of beams is balanced. However, the tensile stress can be unbalanced by heating one or more of the sets of beams; and this can be used to move the shuttle over a distance of up to several tens of microns. The MEM apparatus can be used to form a MEM relay having relatively high contact and opening forces, and with or without a latching capability.

  16. Stress analysis and evaluation of a rectangular pressure vessel

    SciTech Connect (OSTI)

    Rezvani, M.A.; Ziada, H.H.; Shurrab, M.S.

    1992-10-01

    This study addresses structural analysis and evaluation of an abnormal rectangular pressure vessel, designed to house equipment for drilling and collecting samples from Hanford radioactive waste storage tanks. It had to be qualified according to ASME boiler and pressure vessel code, Section VIII; however, it had the cover plate bolted along the long face, a configuration not addressed by the code. Finite element method was used to calculate stresses resulting from internal pressure; these stresses were then used to evaluate and qualify the vessel. Fatigue is not a concern; thus, it can be built according to Section VIII, Division I instead of Division 2. Stress analysis was checked against the code. A stayed plate was added to stiffen the long side of the vessel.

  17. Thermophysical property and pore structure evolution in stressed and non-stressed neutron irradiated IG-110 nuclear graphite

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Snead, Lance L.; Contescu, C. I.; Byun, T. S.; Porter, W.

    2016-04-23

    The nuclear graphite, IG-110, was irradiated with and without a compressive load of 5 MPa at ~400 C up to 9.3x1025 n/m2 (E>0.1 MeV.) Following irradiation physical properties were studied to compare the effect of graphite irradiation on microstructure developed under compression and in stress-free condition. Properties included: dimensional change, thermal conductivity, dynamic modulus, and CTE. The effect of stress on open internal porosity was determined through nitrogen adsorption. The IG-110 graphite experienced irradiation-induced creep that is differentiated from irradiation-induced swelling. Irradiation under stress resulted in somewhat greater thermal conductivity and coefficient of thermal expansion. While a significant increase inmore » dynamic modulus occurs, no differentiation between materials irradiated with and without compressive stress was observed. Nitrogen adsorption analysis suggests a difference in pore evolution in the 0.3-40 nm range for graphite irradiated with and without stress, but this evolution is seen to be a small contributor to the overall dimensional change.« less

  18. Modeling of residual stresses by HY-100 weldments

    SciTech Connect (OSTI)

    Zacharia, T.; Taljat, B.; Radhakrishnan, B.

    1997-02-01

    Residual stress distribution in a HY-100 steel disk, induced by GTA spot welding, was analyzed by finite element (FE) formulations and measured by neutron diffraction (ND). Computations used temperature- dependent thermophysical and mechanical properties. FE model predictions are in good agreement with ND data in far heat affected zone (HAZ) and in base metal. Predicted residual stresses in fusion zone and near HAZ were higher than those measured by ND. This discrepancy was attributed to microstructural changes and associated material properties in the HAZ and fusion zone due to phase transformations during the weld thermal cycle.

  19. Accelerated Stress Testing, Qualification Testing, HAST, Field Experience

    Broader source: Energy.gov [DOE]

    This presentation, which was the opening session of the NREL 2013 Photovoltaic Module Reliability Workshop held on February 26, 2013 in Golden, CO, was presented by John Wohlgemuth. Entitled "Accelerated Stress Testing, Qualification Testing, HAST, Field Experience -- What Do They All Mean?" the presentation details efforts to develop accelerated stress tests beyond the qualification test levels, which are necessary to predict PV module wear-out. The commercial success of PVs is ultimately based on the long-term reliability and safety of the deployed PV modules.

  20. Triple-material stress-strain resistivity gage

    DOE Patents [OSTI]

    Stout, R.B.

    1987-05-19

    A triple material piezoresistive gage provides multi-component elastic stress or strain measurements. Thin foils of three piezoresistive materials, e.g., ytterbium, manganin, and constantan, are configured in a nested serpentine rectilinear grind or other grind arrangement and embedded in a medium, preferably normal to the direction of shock wave propagation. The output of the gage is a resistivity change history for each material of gage. Each resistivity change is independent of the others so that three diagonal components of the elastic stress or strain tensor can be calculated form the resistivity measurements. 4 figs.

  1. Triple-material stress-strain resistivity gage

    DOE Patents [OSTI]

    Stout, R.B.

    1988-05-17

    A triple material piezoresistive gage provides multi-component elastic stress measurements is disclosed. Thin foils of three piezoresistive materials, e.g. ytterbium, manganin, and constantan, are configured in a nested serpentine rectilinear grid or other grid arrangement and embedded in a medium, preferably normal to the direction of shock wave propagation. The output of the gage is a resistivity change history for each material of the gage. Each resistivity change is independent of the others so that three diagonal components of the elastic stress or strain tensor can be calculated from the resistivity measurements. 4 figs.

  2. Triple-material stress-strain resistivity gage

    DOE Patents [OSTI]

    Stout, Ray B.

    1988-01-01

    A triple material piezoresistive gage provides multi-component elastic stress or measurements. Thin foils of three piezoresistive materials, e.g. ytterbium, manganin, and constantan, are configured in a nested serpentine rectilinear grid or other grid arrangement and embedded in a medium, preferably normal to the direction of shock wave propagation. The output of the gage is a resistivity change history for each material of the gage. Each resistivity change is independent of the others so that three diagonal components of the elastic stress or strain tensor can be calculated from the resistivity measurements.

  3. Alloy 400 tube failures by stress corrosion cracking

    SciTech Connect (OSTI)

    Amar, A.S.

    1995-12-01

    A feedwater heater with SB163 Alloy 400 (cold drawn - stress relieved) tubing experienced numerous tube failures and was replaced after of 4.5 years. Failures were attributed to Inter Granular Stress Corrosion Cracking (IGSCC) in the roll transition area. An eddy current test method was developed with EPRI NDE Center technical support to detect the cracks in the tubesheet region. Three tubes were pulled for metallurgical examination. Short axial cracks were found on tube inner surface. Measured crack depths were correlated with the eddy current indications. A large number of tubes were plugged. However, the heater continued to deteriorate rapidly. Potential contributors to IGSCC are discussed.

  4. High voltage bushing having weathershed and surrounding stress relief collar

    DOE Patents [OSTI]

    Cookson, Alan H.

    1981-01-01

    A high voltage electric bushing comprises a hollow elongated dielectric weathershed which encloses a high voltage conductor. A collar formed of high voltage dielectric material is positioned over the weathershed and is bonded thereto by an interface material which precludes moisture-like contaminants from entering between the bonded portions. The collar is substantially thicker than the adjacent weathershed which it surrounds, providing relief of the electric stresses which would otherwise appear on the outer surface of the weathershed. The collar may include a conductive ring or capacitive foil to further relieve electric stresses experienced by the bushing.

  5. Tn-seq of Caulobacter crescentus under uranium stress reveals genes essential for detoxification and stress tolerance

    SciTech Connect (OSTI)

    Yung, Mimi C.; Park, Dan M.; Overton, K. Wesley; Blow, Matthew J.; Hoover, Cindi A.; Smit, John R.; Murray, Sean R.; Ricci, Dante P.; Christen, Beat; Bowman, Grant R.; Jiao, Yongqin

    2015-07-20

    Ubiquitous aquatic bacterium Caulobacter crescentus is highly resistant to uranium (U) and facilitates U biomineralization and thus holds promise as an agent of U bioremediation. In order to gain an understanding of how C. crescentus tolerates U, we employed transposon (Tn) mutagenesis paired with deep sequencing (Tn-seq) in a global screen for genomic elements required for U resistance. Of the 3,879 annotated genes in the C. crescentus genome, 37 were found to be specifically associated with fitness under U stress, 15 of which were subsequently tested through mutational analysis. Systematic deletion analysis revealed that mutants lacking outer membrane transporters (rsaFa and rsaFb), a stress-responsive transcription factor (cztR), or a ppGpp synthetase/hydrolase (spoT) exhibited a significantly lower survival rate under U stress. RsaFa and RsaFb, which are homologues of TolC in Escherichia coli, have previously been shown to mediate S-layer export. Transcriptional analysis revealed upregulation of rsaFa and rsaFb by 4- and 10-fold, respectively, in the presence of U. We additionally show that rsaFa mutants accumulated higher levels of U than the wild type, with no significant increase in oxidative stress levels. These results suggest a function for RsaFa and RsaFb in U efflux and/or maintenance of membrane integrity during U stress. In addition, we present data implicating CztR and SpoT in resistance to U stress. Together, our findings reveal novel gene targets that are key to understanding the molecular mechanisms of U resistance in C. crescentus.

  6. Tn-seq of Caulobacter crescentus under uranium stress reveals genes essential for detoxification and stress tolerance

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yung, Mimi C.; Park, Dan M.; Overton, K. Wesley; Blow, Matthew J.; Hoover, Cindi A.; Smit, John R.; Murray, Sean R.; Ricci, Dante P.; Christen, Beat; Bowman, Grant R.; et al

    2015-07-20

    Ubiquitous aquatic bacterium Caulobacter crescentus is highly resistant to uranium (U) and facilitates U biomineralization and thus holds promise as an agent of U bioremediation. In order to gain an understanding of how C. crescentus tolerates U, we employed transposon (Tn) mutagenesis paired with deep sequencing (Tn-seq) in a global screen for genomic elements required for U resistance. Of the 3,879 annotated genes in the C. crescentus genome, 37 were found to be specifically associated with fitness under U stress, 15 of which were subsequently tested through mutational analysis. Systematic deletion analysis revealed that mutants lacking outer membrane transporters (rsaFamore » and rsaFb), a stress-responsive transcription factor (cztR), or a ppGpp synthetase/hydrolase (spoT) exhibited a significantly lower survival rate under U stress. RsaFa and RsaFb, which are homologues of TolC in Escherichia coli, have previously been shown to mediate S-layer export. Transcriptional analysis revealed upregulation of rsaFa and rsaFb by 4- and 10-fold, respectively, in the presence of U. We additionally show that rsaFa mutants accumulated higher levels of U than the wild type, with no significant increase in oxidative stress levels. These results suggest a function for RsaFa and RsaFb in U efflux and/or maintenance of membrane integrity during U stress. In addition, we present data implicating CztR and SpoT in resistance to U stress. Together, our findings reveal novel gene targets that are key to understanding the molecular mechanisms of U resistance in C. crescentus.« less

  7. Laboratory investigation on the effect of in situ stresses on hydraulic fracture containment

    SciTech Connect (OSTI)

    Warpinski, N. R.; Clark, J. A.; Schmidt, R. A.; Huddle, C. W.

    1981-01-01

    Laboratory experiments have been conducted to determine the effect of in situ stress variations on hydraulic fracture containment. Fractures were initiated in layered rock samples with prescribed stress variations, and fracture growth characteristics were determined as a function of stress levels. Stress contrasts of 2-3 MPa were found to be sufficient to restrict fracture growth in laboratory samples of Nevada tuff and Tennessee and Nugget sandstones. The required stress level was found not to depend on mechanical rock properties. However, permeability and the resultant pore pressure effects were found to be important. Tests conducted at bimaterial interfaces between Nugget and Tennessee sandstone show that the resultant stresses set up near the interface due to the applied overburden stress affect the fracture behavior in the same way as the applied confining stresses. These results provide a guideline for determining the in situ stress contrast necessary to contain a fracture in a field treatment.

  8. Laminated metal composite formed from low flow stress layers and high flow stress layers using flow constraining elements and making same

    DOE Patents [OSTI]

    Syn, C.K.; Lesuer, D.R.

    1995-07-04

    A laminated metal composite of low flow stress layers and high flow stress layers is described which is formed using flow constraining elements, preferably in the shape of rings, individually placed around each of the low flow stress layers while pressure is applied to the stack to bond the layers of the composite together, to thereby restrain the flow of the low flow stress layers from the stack during the bonding. The laminated metal composite of the invention is made by the steps of forming a stack of alternate layers of low flow stress layers and high flow stress layers with each layer of low flow stress material surrounded by an individual flow constraining element, such as a ring, and then applying pressure to the top and bottom surfaces of the resulting stack to bond the dissimilar layers together, for example, by compression rolling the stack. In a preferred embodiment, the individual flow constraining elements surrounding the layers of low flow stress material are formed of a material which may either be the same material as the material comprising the high flow stress layers, or have similar flow stress characteristics to the material comprising the high flow stress layers. Additional sacrificial layers may be added to the top and bottom of the stack to avoid damage to the stack during the bonding step; and these additional layers may then be removed after the bonding step. 5 figs.

  9. Laminated metal composite formed from low flow stress layers and high flow stress layers using flow constraining elements and making same

    DOE Patents [OSTI]

    Syn, Chol K.; Lesuer, Donald R.

    1995-01-01

    A laminated metal composite of low flow stress layers and high flow stress layers is described which is formed using flow constraining elements, preferably in the shape of rings, individually placed around each of the low flow stress layers while pressure is applied to the stack to bond the layers of the composite together, to thereby restrain the flow of the low flow stress layers from the stack during the bonding. The laminated metal composite of the invention is made by the steps of forming a stack of alternate layers of low flow stress layers and high flow stress layers with each layer of low flow stress material surrounded by an individual flow constraining element, such as a ring, and then applying pressure to the top and bottom surfaces of the resulting stack to bond the dissimilar layers together, for example, by compression rolling the stack. In a preferred embodiment, the individual flow constraining elements surrounding the layers of low flow stress material are formed of a material which may either be the same material as the material comprising the high flow stress layers, or have similar flow stress characteristics to the material comprising the high flow stress layers. Additional sacrificial layers may be added to the top and bottom of the stack to avoid damage to the stack during the bonding step; and these additional layers may then be removed after the bonding step.

  10. Accelerated stress rupture lifetime assessment for fiber composites

    SciTech Connect (OSTI)

    Groves, S.E.; DeTeresa, S.J.; Sanchez, R.J.; Zocher, M.A.; Christensen, R.M.

    1997-02-01

    Objective was to develop a theoretical and experimental framework for predicting stress rupture lifetime for fiber polymer composites based on short-term accelerated testing. Originally a 3-year project, it was terminated after the first year, which included stress rupture experiments and viscoelastic material characterization. In principle, higher temperature, stress, and saturated environmental conditions are used to accelerate stress rupture. Two types of specimens were to be subjected to long-term and accelerated static tensile loading at various temperatures, loads in order to quantify both fiber and matrix dominated failures. Also, we were to apply state-of-the-art analytical and experimental characterization techniques developed under a previous DOE/DP CRADA for capturing and tracking incipient degradation mechanisms associated with mechanical performance. Focus was increase our confidence to design, analyze, and build long-term composite structures such as flywheels and hydrogen gas storage vessels; other applications include advanced conventional weapons, infrastructures, marine and offshore systems, and stockpile stewardship and surveillance. Capabilities developed under this project, though not completed or verified, are being applied to NIF, AVLIS, and SSMP programs.

  11. Electrochemical aspects of stress-corrosion crack growth

    SciTech Connect (OSTI)

    Newman, R.C.; Sieradzki, K.

    1982-06-01

    Some contributions of electrochemical methods to the understanding of stress-corrosion cracking are described, with examples drawn from studies of stainless steels, nickel alloys and brasses. Considerations related to the local alloy composition, solution composition and electrode potential within a crack are classified and illustrated. The relationship between electrochemical and acoustic noise is discussed.

  12. Primary side stress corrosion cracking and remedial measures

    SciTech Connect (OSTI)

    Theus, G.J.

    1986-01-01

    Primary side stress corrosion cracking (SCC) of Alloy 600 stream generator tubing in some recirculating pressurized water reactor steam generators has usually occurred in two locations: at the roll transition and expansion locations within the tube-sheets and at the apex and tangent areas of the tight radius U bends. Occasionally, other highly stressed areas have also suffered primary side SCC: at support plate tube intersections where secondary side denting has occurred and at the steam generator tube transition areas of explosively installed mini-sleeves. Laboratory data and operating performances of Alloy 600 tubing indicate that the factors affecting the susceptibility to this type of SSC, in decreasing order of importance, are high stresses, material microstructures, and operating temperatures. Remedial measures to correct these problems in newer plants include changing design and fabrication procedures, thus avoiding highly stressed areas of tubing, and changing tube manufacturing heat treating requirements, thus improving the microstructures. Alternate tube materials, such as Alloy 800, Monel 400, or austenitic stainless steels, have not suffered this type of failure.

  13. Stress corrosion crack tip microstructure in nickel-based alloys

    SciTech Connect (OSTI)

    Shei, S.A.; Yang, W.J.

    1994-04-01

    Stress corrosion cracking behavior of several nickel-base alloys in high temperature caustic environments has been evaluated. The crack tip and fracture surfaces were examined using Auger/ESCA and Analytical Electron Microscopy (AEM) to determine the near crack tip microstructure and microchemistry. Results showed formation of chromium-rich oxides at or near the crack tip and nickel-rich de-alloying layers away from the crack tip. The stress corrosion resistance of different nickel-base alloys in caustic may be explained by the preferential oxidation and dissolution of different alloying elements at the crack tip. Alloy 600 (UNS N06600) shows good general corrosion and intergranular attack resistance in caustic because of its high nickel content. Thermally treated Alloy 690 (UNS N06690) and Alloy 600 provide good stress corrosion cracking resistance because of high chromium contents along grain boundaries. Alloy 625 (UNS N06625) does not show as good stress corrosion cracking resistance as Alloy 690 or Alloy 600 because of its high molybdenum content.

  14. Progress Report on Alloy 617 Isochronous Stress-Strain Curves

    SciTech Connect (OSTI)

    Jill K. Wright; Richard N. Wright; Nancy J. Lybeck

    2014-03-01

    Isochronous stress-strain curves for Alloy 617 up to a temperature of 1000°C will be required to qualify the material for elevated temperature design in Section III, Division 1, Subsection NH of the ASME Boiler and Pressure Vessel Code. Several potential methods for developing these curves are reviewed in this report. It is shown that in general power-law creep is the rate controlling deformation mechanism for a wide range of alloy heats, test temperatures and stresses. Measurement of the strain rate sensitivity of Alloy 617 indicates that the material is highly strain rate sensitive in the tensile deformation range above about 750°C. This suggests that the concept of a hot tensile curve as a bounding case on the isochronous stress-strain diagrams is problematic. The impact of strain rate on the hot tensile curves is examined and it is concluded that incorporating such a curve is only meaningful if a single tensile strain rate (typically the ASTM standard rate of 0.5%/min) is arbitrarily defined. Current experimentally determined creep data are compared to isochronous stress-strain curves proposed previously by the German programs in the 1980s and by the 1990 draft ASME Code Case. Variability in how well the experimental data are represented by the proposed design curves that suggests further analysis is necessary prior to completing a new draft Code Case.

  15. Zymomonas with improved xylose utilization in stress conditions

    DOE Patents [OSTI]

    Caimi, Perry G; Emptage, Mark; Li, Xu; Viitanen, Paul V; Chou, Yat-Chen; Franden, Mary Ann; Zhang, Min

    2013-06-18

    Strains of xylose utilizing Zymomonas with improved xylose utilization and ethanol production during fermentation in stress conditions were obtained using an adaptation method. The adaptation involved continuously growing xylose utilizing Zymomonas in media containing high sugars, acetic acid, ammonia, and ethanol.

  16. Method to reduce dislocation density in silicon using stress

    DOE Patents [OSTI]

    Buonassisi, Anthony; Bertoni, Mariana; Argon, Ali; Castellanos, Sergio; Fecych, Alexandria; Powell, Douglas; Vogl, Michelle

    2013-03-05

    A crystalline material structure with reduced dislocation density and method of producing same is provided. The crystalline material structure is annealed at temperatures above the brittle-to-ductile transition temperature of the crystalline material structure. One or more stress elements are formed on the crystalline material structure so as to annihilate dislocations or to move them into less harmful locations.

  17. Finite element analyses of tool stresses in metal cutting processes

    SciTech Connect (OSTI)

    Kistler, B.L.

    1997-01-01

    In this report, we analytically predict and examine stresses in tool tips used in high speed orthogonal machining operations. Specifically, one analysis was compared to an existing experimental measurement of stresses in a sapphire tool tip cutting 1020 steel at slow speeds. In addition, two analyses were done of a carbide tool tip in a machining process at higher cutting speeds, in order to compare to experimental results produced as part of this study. The metal being cut was simulated using a Sandia developed damage plasticity material model, which allowed the cutting to occur analytically without prespecifying the line of cutting/failure. The latter analyses incorporated temperature effects on the tool tip. Calculated tool forces and peak stresses matched experimental data to within 20%. Stress contours generally agreed between analysis and experiment. This work could be extended to investigate/predict failures in the tool tip, which would be of great interest to machining shops in understanding how to optimize cost/retooling time.

  18. Internal stress distribution for generating closure domains in laser-irradiated Fe3%Si(110) steels

    SciTech Connect (OSTI)

    Iwata, Keiji; Imafuku, Muneyuki; Orihara, Hideto; Sakai, Yusuke; Ohya, Shin-Ichi; Suzuki, Tamaki; Shobu, Takahisa; Akita, Koichi; Ishiyama, Kazushi

    2015-05-07

    Internal stress distribution for generating closure domains occurring in laser-irradiated Fe3%Si(110) steels was investigated using high-energy X-ray analysis and domain theory based on the variational principle. The measured triaxial stresses inside the specimen were compressive and the stress in the rolling direction became more dominant than stresses in the other directions. The calculations based on the variational principle of magnetic energy for closure domains showed that the measured triaxial stresses made the closure domains more stable than the basic domain without closure domains. The experimental and calculation results reveal that the laser-introduced internal stresses result in the occurrence of the closure domains.

  19. DEVELOPMENT OF PLASTICITY MODEL USING NON ASSOCIATED FLOW RULE FOR HCP MATERIALS INCLUDING ZIRCONIUM FOR NUCLEAR APPLICATIONS

    SciTech Connect (OSTI)

    Michael V. Glazoff; Jeong-Whan Yoon

    2013-08-01

    In this report (prepared in collaboration with Prof. Jeong Whan Yoon, Deakin University, Melbourne, Australia) a research effort was made to develop a non associated flow rule for zirconium. Since Zr is a hexagonally close packed (hcp) material, it is impossible to describe its plastic response under arbitrary loading conditions with any associated flow rule (e.g. von Mises). As a result of strong tension compression asymmetry of the yield stress and anisotropy, zirconium displays plastic behavior that requires a more sophisticated approach. Consequently, a new general asymmetric yield function has been developed which accommodates mathematically the four directional anisotropies along 0 degrees, 45 degrees, 90 degrees, and biaxial, under tension and compression. Stress anisotropy has been completely decoupled from the r value by using non associated flow plasticity, where yield function and plastic potential have been treated separately to take care of stress and r value directionalities, respectively. This theoretical development has been verified using Zr alloys at room temperature as an example as these materials have very strong SD (Strength Differential) effect. The proposed yield function reasonably well models the evolution of yield surfaces for a zirconium clock rolled plate during in plane and through thickness compression. It has been found that this function can predict both tension and compression asymmetry mathematically without any numerical tolerance and shows the significant improvement compared to any reported functions. Finally, in the end of the report, a program of further research is outlined aimed at constructing tensorial relationships for the temperature and fluence dependent creep surfaces for Zr, Zircaloy 2, and Zircaloy 4.

  20. Thin Silicon MEMS Contact-Stress Sensor (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    sensor capable of accurate in situ measruement of time-varying, contact-stress between two solid interfaces (e.g. in vivo cartilage contact-stress and body armor dynamic loading). ...

  1. A Model For Stress-Controlled Pipe Growth | Open Energy Information

    Open Energy Info (EERE)

    Stress-Controlled Pipe Growth Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A Model For Stress-Controlled Pipe Growth Abstract The rock...

  2. Stress induced anisotropy in CoFeMn soft magnetic nanocomposites...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Stress induced anisotropy in CoFeMn soft magnetic nanocomposites Citation Details In-Document Search Title: Stress induced anisotropy in CoFeMn soft magnetic ...

  3. Thin Silicon MEMS Contact-Stress Sensor (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    ...ontact-stress sensor continuously and accurately measures time-varying, solid interface loads over tens of thousands of load cycles. The contact-stress sensor is extremely thin ...

  4. Thin Silicon MEMS Contact-Stress Sensor (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    work offers the first, thin, MEMS contact-stress (CS) sensor capable of accurate in situ measruement of time-varying, contact-stress between two solid interfaces (e.g. in vivo ...

  5. Phase-field Model for Stress-dependent Ginsburg-Landau Kinetics...

    Office of Scientific and Technical Information (OSTI)

    Model for Stress-dependent Ginsburg-Landau Kinetics for Large Deformation of Silicon Anodes Citation Details In-Document Search Title: Phase-field Model for Stress-dependent ...

  6. A model for residual stress evolution in air-plasma-sprayed zirconia thermal barrier coatings

    SciTech Connect (OSTI)

    Nair, B. G.; Singh, J. P.; Grimsditch, M.

    2000-02-28

    Ruby fluorescence spectroscopy indicates that residual stress in air-plasma-sprayed zirconia thermal barrier coatings is a function of the local interface geometry. The stress profile of a simulated rough interface characterized by ``peaks'' and ``valleys'' was modeled with a finite-element approach that accounted for thermal mismatch, oxide scale growth, and top coat sintering. Dependence of the stress profile on interface geometry and microstructure was investigated, and the results were compared with measured stresses.

  7. Filling and solidification with coupled heat transfer and stress analysis

    SciTech Connect (OSTI)

    Ruiz, D.J.; Khandhia, Y.

    1995-12-31

    A full filling and solidification simulation of the MCWASP 7 casting has been carried out using the commercial finite element (FE) analysis codes LS-DYNA3D and FIDAP. The two codes were used to carry out back-to-back analysis of the mould filling. Both codes track the free surface and predict filling times. LS-DYNA3D has been used both for the filling simulation and to carry out a coupled thermal and stress analysis of the casting during solidification, predicting cooling rates, residual stresses and as-cast shape. The methodology used and details of the FE models are summarized. Results are presented for comparison with the casting trial data (x-rays of filling and thermocouple data).

  8. Thick, low-stress films, and coated substrates formed therefrom

    DOE Patents [OSTI]

    Henager, Jr., Charles H.; Knoll, Robert W.

    1991-01-01

    Stress-induced deformation, and the damage resulting therefrom, increases with film thickness. The overcoming of excessive stress by the use of the film material of the present invention, permits the formation of thick films that are necessary for certain of the above described applications. The most likely use for the subject film materials, other than their specialized views as an optical film, is for microelectronic packaging of components on silicon substrates. In general, the subject Si-Al-O-N films have excellent adherence to the underlying substrate, a high degree of hardness and durability, and are excellent insulators. Prior art elevated temperature deposition processes cannot meet the microelectronic packaging temperature formation constraints. The process of the present invention is conducted under non-elevated temperature conditions, typically 500# C. or less.

  9. A residual stress study in similar and dissimilar welds

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Eisazadeh, Hamid; Goldak, John A.; Aidun, Daryush K.; Coules, Harry E.; Bunn, Jeffrey R; Achuthan, A.

    2016-04-01

    Residual strain distributions in similar and dissimilar welds were measured using neutron diffraction (ND) method. Then, using three strain components, three-dimensional stress states were calculated. The results were used to determine the effect of the martensitic phase transformation and material properties on residual stress (RS) distribution. It was observed that smaller longitudinal RS was induced in the low carbon steel side of dissimilar weld when compared to its similar weld. Also, it was found that the transverse RS near and within the weld zone (WZ) in dissimilar weld exhibited a distinctive trend, with tensile mode reaching the yield strength ofmore » the base metal (BM). In order to characterize the WZ in dissimilar weld, we deployed optical microscopy, hardness, and energy dispersive X-ray spectroscopy (EDAX). This study not only provides further insight into the RS state in similar and dissimilar welds; it also delivers important consequences of phase transformation in the latter case.« less

  10. Stress corrosion cracking of zirconium used in the reprocessing plant

    SciTech Connect (OSTI)

    Kato, Chiaki; Motooka, Takafumi; Yamamoto, Masahiro

    2007-07-01

    We investigated stress corrosion cracking (SCC) of zirconium by constant load test and the small-scale mock-up test simulated the fuel dissolve. These tests operated in the simulated solution, which substituted non-radioactive elements, i.e. V with radioactive elements such as Pu and Np. From the results of constant load test, the cracks were not observed on 150 MPa after 908 hours in approximately 3 % strain. However a lot of cracks caused by SCC were observed over 20 % strain under high tensile stress in the simulated solution and the heat-transfer condition having more corrosive circumstance and noble potential accelerated the susceptibility of SCC. The cracking behavior would be caused by the creep phenomena. The small-scale mock-up test had been operated for about 50000 hours during 7 year. From the results, zirconium showed excellent corrosion resistance and no SCC was observed during these long-term operations. (authors)

  11. Protein structure and hydration probed by SANS and osmotic stress

    SciTech Connect (OSTI)

    Rau, Dr. Donald [National Institutes of Health

    2008-01-01

    Interactions governing protein folding, stability, recognition, and activity are mediated by hydration. Here, we use small-angle neutron scattering coupled with osmotic stress to investigate the hydration of two proteins, lysozyme and guanylate kinase (GK), in the presence of solutes. By taking advantage of the neutron contrast variation that occurs upon addition of these solutes, the number of protein-associated (solute-excluded) water molecules can be estimated from changes in both the zero-angle scattering intensity and the radius of gyration. Poly(ethylene glycol) exclusion varies with molecular weight. This sensitivity can be exploited to probe structural features such as the large internal GK cavity. For GK, small-angle neutron scattering is complemented by isothermal titration calorimetry with osmoticstress to also measure hydration changes accompanying ligand binding. These results provide a framework for studying other biomolecular systems and assemblies using neutron scattering together with osmotic stress.

  12. Stress analysis of closure bolts for shipping casks

    SciTech Connect (OSTI)

    Mok, G.C.; Fischer, L.E. ); Hsu, S.T. )

    1993-01-01

    This report specifies the requirements and criteria for stress analysis of closure bolts for shipping casks containing nuclear spent fuels or high level radioactive materials. The specification is based on existing information conceming the structural behavior, analysis, and design of bolted joints. The approach taken was to extend the ASME Boiler and Pressure Vessel Code requirements and criteria for bolting analysis of nuclear piping and pressure vessels to include the appropriate design and load characteristics of the shipping cask. The characteristics considered are large, flat, closure lids with metal-to-metal contact within the bolted joint; significant temperature and impact loads; and possible prying and bending effects. Specific formulas and procedures developed apply to the bolt stress analysis of a circular, flat, bolted closure. The report also includes critical load cases and desirable design practices for the bolted closure, an in-depth review of the structural behavior of bolted joints, and a comprehensive bibliography of current information on bolted joints.

  13. Thermal mechanical stress modeling of GCtM seals

    SciTech Connect (OSTI)

    Dai, Steve Xunhu; Chambers, Robert

    2015-09-01

    Finite-element thermal stress modeling at the glass-ceramic to metal (GCtM) interface was conducted assuming heterogeneous glass-ceramic microstructure. The glass-ceramics were treated as composites consisting of high expansion silica crystalline phases dispersed in a uniform residual glass. Interfacial stresses were examined for two types of glass-ceramics. One was designated as SL16 glass -ceramic, owing to its step-like thermal strain curve with an overall coefficient of thermal expansion (CTE) at 16 ppm/C. Clustered Cristobalite is the dominant silica phase in SL16 glass-ceramic. The other, designated as NL16 glass-ceramic, exhibited clusters of mixed Cristobalite and Quartz and showed a near-linear thermal strain curve with a same CTE value.

  14. Using Uncertainty Analysis to Guide the Development of Accelerated Stress Tests (Presentation)

    SciTech Connect (OSTI)

    Kempe, M.

    2014-03-01

    Extrapolation of accelerated testing to the long-term results expected in the field has uncertainty associated with the acceleration factors and the range of possible stresses in the field. When multiple stresses (such as temperature and humidity) can be used to increase the acceleration, the uncertainty may be reduced according to which stress factors are used to accelerate the degradation.

  15. 2010 MICROBIAL STRESS RESPONSE GORDON RESEARCH CONFERENCE, JULY 18-23, 2010

    SciTech Connect (OSTI)

    Sarah Ades

    2011-07-23

    The 2010 Gordon Research Conference on Microbial Stress Responses provides an open and exciting forum for the exchange of scientific discoveries on the remarkable mechanisms used by microbes to survive in nearly every niche on the planet. Understanding these stress responses is critical for our ability to control microbial survival, whether in the context of biotechnology, ecology, or pathogenesis. From its inception in 1994, this conference has traditionally employed a very broad definition of stress in microbial systems. Sessions will cover the major steps of stress responses from signal sensing to transcriptional regulation to the effectors that mediate responses. A wide range of stresses will be represented. Some examples include (but are not limited to) oxidative stress, protein quality control, antibiotic-induced stress and survival, envelope stress, DNA damage, and nutritional stress. The 2010 meeting will also focus on the role of stress responses in microbial communities, applied and environmental microbiology, and microbial development. This conference brings together researchers from both the biological and physical sciences investigating stress responses in medically- and environmentally relevant microbes, as well as model organisms, using cutting-edge techniques. Computational, systems-level, and biophysical approaches to exploring stress responsive circuits will be integrated throughout the sessions alongside the more traditional molecular, physiological, and genetic approaches. The broad range of excellent speakers and topics, together with the intimate and pleasant setting at Mount Holyoke College, provide a fertile ground for the exchange of new ideas and approaches.

  16. Petascale Simulations of Stress Corrosion Cracking | Argonne Leadership

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

    Computing Facility 45,000,000 Year: 2012 Research Domain: Materials Science The performance and lifetime of materials widely used in energy and nuclear technologies are often severely limited by corrosion under stress loads. Particularly important for the DOE are environmental degradations of nickel-based alloys in advanced nuclear reactors and in glass containers of nuclear waste. This team performs petascale reactive molecular dynamics (MD) and quantum mechanical (QM) simulations to

  17. Thermal Stress and Reliability for Advanced Power Electronics and Electric

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

    Machines | Department of Energy 2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting, May 18-22, 2009 -- Washington D.C. ape_14_okeefe.pdf (969.92 KB) More Documents & Publications Thermal Stress and Reliability for Advanced Power Electronics and Electric Machines Power Electronic Thermal System Performance and Integration Thermal Performance and Reliability of Bonded Interfaces

  18. Software for a Multi-beam Optical Stress Sensor

    Energy Science and Technology Software Center (OSTI)

    2000-04-19

    This software program tracks multiple laser beam spots reflected from a substrate which is changing its shape in response to changes in environment or changes in its physical state. The geometry of the laser, substrate, camera, and substrate parameters result in a final measurement of the stress-thickness product that would bend the substrate to its final curvature. A typical example is thin film growth.

  19. Microorganisms having enhanced tolerance to inhibitors and stress

    DOE Patents [OSTI]

    Brown, Steven D.; Yang, Shihui

    2014-07-29

    The present invention provides genetically modified strains of microorganisms that display enhanced tolerance to stress and/or inhibitors such as sodium acetate and vanillin. The enhanced tolerance can be achieved by increasing the expression of a protein of the Sm-like superfamily such as a bacterial Hfq protein and a fungal Sm or Lsm protein. Further, the present invention provides methods of producing alcohol from biomass materials by using the genetically modified microorganisms of the present invention.

  20. Toxicological and pharmacological concerns on oxidative stress and related diseases

    SciTech Connect (OSTI)

    Saeidnia, Soodabeh; Abdollahi, Mohammad

    2013-12-15

    Although reactive oxygen species (ROS) such as superoxide, hydrogen peroxide and hydroxyl radical are generated as the natural byproduct of normal oxygen metabolism, they can create oxidative damage via interaction with bio-molecules. The role of oxidative stress as a remarkable upstream part is frequently reported in the signaling cascade of inflammation as well as chemo attractant production. Even though hydrogen peroxide can control cell signaling and stimulate cell proliferation at low levels, in higher concentrations it can initiate apoptosis and in very high levels may create necrosis. So far, the role of ROS in cellular damage and death is well documented with implicating in a broad range of degenerative alterations e.g. carcinogenesis, aging and other oxidative stress related diseases (OSRDs). Reversely, it is cleared that antioxidants are potentially able to suppress (at least in part) the immune system and to enhance the normal cellular protective responses to tissue damage. In this review, we aimed to provide insights on diverse OSRDs, which are correlated with the concept of oxidative stress as well as its cellular effects that can be inhibited by antioxidants. Resveratrol, angiotensin converting enzyme inhibitors, angiotensin receptor blockers, statins, nebivolol and carvedilol, pentaerythritol tetranitrate, mitochondria-targeted antioxidants, and plant-derived drugs (alone or combined) are the potential medicines that can be used to control OSRD.

  1. Stress corrosion cracking of welded Alloy 600 penetration mockups

    SciTech Connect (OSTI)

    Sarver, J.M.; Pathania, R.S.; Stuckey, K.; Fyfitch, S.; Gelpi, A.; Foucault, M.; Hunt, E.S.

    1995-12-31

    The primary water stress corrosion cracking (PWSCC) of Alloy 600 in components other than steam generators is a problem of increasing concern for nuclear power plants. Of greatest concern at the present time is the PWSCC of Alloy 600 vessel head penetrations. The common elements of these components are threefold: (1) the Alloy 600 material has a susceptible microstructure, (2) the Alloy 600 material is either a thick-walled tube or a bar which has been machined into a thick-walled tube, and (3) the Alloy 600 material has been welded into a structure such that high residual welding stresses exist in the postwelded Alloy 600 material. The objectives of the present program were to evaluate the PWSCC behavior of various configurations of welded Alloy 600 penetrations, and possible remedial measures which would prevent or retard PWSCC in these components. Mockups were instrumented to permit instantaneous remote sensing of through-wall cracking and were autoclave tested along with control C-rings in a doped steam environment. Following the test exposures, the mockups were split and examined to characterize the cracking morphology and the material microstructure. A Weibull distribution was used to analyze the time-to-failure results, and the observed cracking locations were compared to residual stress levels predicted by an elastic-plastic finite element analysis of the mockups.

  2. Residual Stress Evaluation within a Crimped Splice Connector Assembly

    SciTech Connect (OSTI)

    Wang, Jy-An John; An, Ke; Lara-Curzio, Edgar; Hubbard, Camden R; King Jr, Thomas J; Graziano, Joe; Chan, John

    2006-01-01

    In power transmission, connectors play an important role in the efficiency and reliability of the system. Due to the increase of power demand and lack of new infrastructure, existing overhead power transmission lines often need to operate at temperatures higher than the original design criteria. However, this had led to the accelerated aging and degradation of splice connectors, which has been manifested by the formation of hot-spots that have been revealed by infrared imaging during inspection of transmission lines operating at elevated temperatures. The implications of connector aging is two-fold: (1) significant increase in resistivity of the splice connector (i.e., less efficient transmission of electricity) and (2) significant reduction in the connector clamping strength, which ultimately results in separation of the power transmission line at the joint. Therefore, the splice connector has become the weakest link in the electric power transmission infrastructure. The compressive residual stresses induced by the crimping process within the splice provide the clamping forces to secure the conductor and therefore, the determination of the state of residual stresses in splice connectors is a necessary requirement to provide an accurate estimate of their service lifetime. This paper presents a protocol of utilizing finite-element analysis and neutron scattering experiments for evaluating the residual stress fields within a crimped single-stage splice connector assembly.

  3. MULTI-PHASE FRACTURE-MATRIX INTERACTIONS UNDER STRESS CHANGES

    SciTech Connect (OSTI)

    A.S. Grader; D. Elsworth; P.M. Halleck; F. Alvarado; A. Alajmi; Z. Karpyn; N. Mohammed; S. Al-Enezi

    2005-06-15

    The main objectives of this project are to quantify the changes in fracture porosity and multiphase transport properties as a function of confining stress. These changes will be integrated into conceptual and numerical models that will improve our ability to predict and optimize fluid transport in fractured system. This report details our progress on: (a) developing the direct experimental measurements of fracture aperture and topology and fluid occupancy using high-resolution x-ray micro-tomography, (b) quantifying the effect of confining stress on the distribution of fracture aperture, and (c) characterization of shear fractures and their impact on multi-phase flow. The three-dimensional surface that describes the large-scale structure of the fracture in the porous medium can be determined using x-ray micro-tomography with significant accuracy. Several fractures have been scanned and the fracture aperture maps have been extracted. The success of the mapping of fracture aperture was followed by measuring the occupancy of the fracture by two immiscible phases, water and decane, and water and kerosene. The distribution of fracture aperture depends on the effective confining stress on the nature of the rock and the type and distribution of the asperities that keep the fracture open. Fracture apertures at different confining stresses were obtained by micro-tomography covering a range of about two thousand psig. Initial analysis of the data shows a significant aperture closure with increase in effective confining stress. Visual descriptions of the process are shown in the report while detailed analysis of the behavior of the distribution of fracture aperture is in progress. Both extensional and shear fractures are being considered. The initial multi-phase flow tests were done in extensional fractures. Several rock samples with induced shear fracture are being studied, and some of the new results are presented in this report. These samples are being scanned in order to

  4. The Correlation of Stress-State and Nano-Mechanical Properties in Au

    SciTech Connect (OSTI)

    HOUSTON,JACK E.; JARAUSCH,K.F.; KIELY,J.D.; RUSSELL,P.E.

    1999-10-07

    A dependence of elastic response on the stress-state of a thin film has been demonstrated using the interfacial force microscope (IFM). Indentation response was measured as a function of the applied biaxial stress-state for 100 nm thick Au films. An increase in measured elastic modulus with applied compressive stress, and a decrease with applied tensile stress was observed. Measurements of elastic modulus before and after applying stress were identical indicating that the observed change in response is not due to a permanent change in film properties.

  5. Influence of reservoir stress path on deformation and permeability of weakly cemented sandstone reservoirs

    SciTech Connect (OSTI)

    Ruistuen, H.; Teufel, L.W.; Rhett, D.

    1996-12-31

    The influence of production-induced changes in reservoir stress state on compressibility and permeability of weakly cemented sandstones has been analyzed. Laboratory experiments simulating reservoir depletion have been conducted for the full range of stress paths that a reservoir may follow. Samples were loaded by reducing the pore pressure and controlling the confining pressure according to the desired stress path from initial reservoir conditions. The results show that compressibility of weakly cemented sandstones are stress path dependent. Compressibilities measured under uniaxial strain conditions, or a stress path with a K value lower than the one associated with uniaxial strain, are more than twice the corresponding value found under hydrostatic loading conditions. In contrast, matrix permeability measured in the maximum stress direction show no significant stress path dependence. Independently of stress path, the observed permeability reductions fall within the general trend expected for a sedimentary rock of relatively high initial permeability. A significant permeability decrease was only observed as the shear stress exceeded the yield limit of the rock, probably due to both mobilization of fine arains and an increase in tortuosity due to collapse of pore space. Results of this study suggest that stress path dependent properties of weakly cemented sandstones is a consequence of the heterogeneous nature of the sedimentary rock. Material properties are affected by grain-scale inelastic deformation processes and the pattern of these deformation processes is primarily controlled by reservoir stress path.

  6. Stress-tuned conductor-polymer composite for use in sensors

    DOE Patents [OSTI]

    Martin, James E; Read, Douglas H

    2013-10-22

    A method for making a composite polymeric material with electrical conductivity determined by stress-tuning of the conductor-polymer composite, and sensors made with the stress-tuned conductor-polymer composite made by this method. Stress tuning is achieved by mixing a miscible liquid into the polymer precursor solution or by absorbing into the precursor solution a soluble compound from vapor in contact with the polymer precursor solution. The conductor may or may not be ordered by application of a magnetic field. The composite is formed by polymerization with the stress-tuning agent in the polymer matrix. The stress-tuning agent is removed following polymerization to produce a conductor-polymer composite with a stress field that depends on the amount of stress-tuning agent employed.

  7. On computing stress in polymer systems involving multi-body potentials from molecular dynamics simulation

    SciTech Connect (OSTI)

    Fu, Yao E-mail: jhsong@cec.sc.edu; Song, Jeong-Hoon E-mail: jhsong@cec.sc.edu

    2014-08-07

    Hardy stress definition has been restricted to pair potentials and embedded-atom method potentials due to the basic assumptions in the derivation of a symmetric microscopic stress tensor. Force decomposition required in the Hardy stress expression becomes obscure for multi-body potentials. In this work, we demonstrate the invariance of the Hardy stress expression for a polymer system modeled with multi-body interatomic potentials including up to four atoms interaction, by applying central force decomposition of the atomic force. The balance of momentum has been demonstrated to be valid theoretically and tested under various numerical simulation conditions. The validity of momentum conservation justifies the extension of Hardy stress expression to multi-body potential systems. Computed Hardy stress has been observed to converge to the virial stress of the system with increasing spatial averaging volume. This work provides a feasible and reliable linkage between the atomistic and continuum scales for multi-body potential systems.

  8. Anisotropy of stress correlation in two-dimensional liquids and a pseudospin model

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wu, Bin; Iwashita, Takuya; Egami, Takeshi

    2015-11-04

    Liquids are condensed matter in which atoms are strongly correlated in position and momentum. The atomic pair density function (PDF) is used often in describing such correlation. However, elucidation of many properties requires higher degrees of correlation than the pair correlation. For instance, viscosity depends upon the stress correlations in space and time. We examine the cross correlation between the stress correlation at the atomic level and the PDF for two-dimensional liquids. We introduce the concept of the stress-resolved pair distribution function (SRPDF) that uses the sign of atomic-level stress as a selection rule to include particles from density correlations.more » The connection between SRPDFs and stress correlation function is explained through an approximation in which the shear stress is replaced by a pseudospin. Lastly, we further assess the possibility of interpreting the long-range stress correlation as a consequence of short-range Ising-like pseudospin interactions.« less

  9. Anisotropy of stress correlation in two-dimensional liquids and a pseudospin model

    SciTech Connect (OSTI)

    Wu, Bin; Iwashita, Takuya; Egami, Takeshi

    2015-11-04

    Liquids are condensed matter in which atoms are strongly correlated in position and momentum. The atomic pair density function (PDF) is used often in describing such correlation. However, elucidation of many properties requires higher degrees of correlation than the pair correlation. For instance, viscosity depends upon the stress correlations in space and time. We examine the cross correlation between the stress correlation at the atomic level and the PDF for two-dimensional liquids. We introduce the concept of the stress-resolved pair distribution function (SRPDF) that uses the sign of atomic-level stress as a selection rule to include particles from density correlations. The connection between SRPDFs and stress correlation function is explained through an approximation in which the shear stress is replaced by a pseudospin. Lastly, we further assess the possibility of interpreting the long-range stress correlation as a consequence of short-range Ising-like pseudospin interactions.

  10. Viscuous Mech Behavior of Rock Mass Under Therm Stress

    Energy Science and Technology Software Center (OSTI)

    1998-10-14

    VISCOT is a nonlinear, transient , thermal-stress, finite-element program designed to determine the viscoelastic, viscoplastic, or elastoplastic deformation of a rock mass due to mechanical and thermal loading. A major application of VISCOT in conjunction with a SCEPTER heat transfer code, e.g. DOT-BPMD, is the thermomechanical analysis of a rock mass such as salt in which significant time-dependent, nonlinear deformations are expected to occur. Such problems include room and canister scale studies during the excavation,more » operation, and long term, post closure stages in a salt repository.« less

  11. Design of an Aluminum Proton Beam Window for the Spallation Neutron Source

    SciTech Connect (OSTI)

    Janney, Jim G; McClintock, David A

    2012-01-01

    An aluminum proton beam window design is being considered at the Spallation Neutron Source primarily to increase the lifetime of the window, with secondary advantages of higher beam transport efficiency and lower activation. The window separates the core vessel, the location of the mercury target, from the vacuum of the accelerator, while withstanding the pass through of a proton beam of up to 2 MW with 1.0 GeV proton energy. The current aluminum alloy being investigated for the window material is 6061-T651 due to its combination of high strength, high thermal conductivity, and good resistance to aqueous corrosion, as well as demonstrated dependability in previous high-radiation environments. The window design will feature a thin plate with closely spaced cross drilled cooling holes. An analytical approach was used to optimize the dimensions of the window before finite element analysis was used to simulate temperature profiles and stress fields resulting from thermal and static pressure loading. The resulting maximum temperature of 60 C and Von Mises stress of 71 MPa are very low compared to allowables for Al 6061-T651. A significant challenge in designing an aluminum proton beam window for SNS is integrating the window with the current 316L SS shield blocks. Explosion bonding was chosen as a joining technique because of the large bonding area required. A test program has commenced to prove explosion bonding can produce a robust vacuum joint. Pending successful explosion bond testing, the aluminum proton beam window design will be proven acceptable for service in the Spallation Neutron Source.

  12. Influence of pore pressure and production-induced changes in pore pressure on in situ stress

    SciTech Connect (OSTI)

    Teufel, L.W.

    1996-02-01

    Knowledge of in situ stress and how stress changes with reservoir depletion and pore pressure drawdown is important in a multi-disciplinary approach to reservoir characterization, reservoir management, and improved oil recovery projects. This report summarizes a compilation of in situ stress data from six fields showing the effects of pore pressure and production-induced changes in pore pressure on the minimum horizontal stress. The in situ stress data and corresponding pore pressure data were obtained from field records of the operating companies and published reports. Horizontal stress was determined from closure pressure data of hydraulic fractures and leak-off tests. The stress measurements clearly demonstrate that the total minimum-horizontal stress is dependent on pore pressure. A decrease in pore pressure either by geologic processes or production of a reservoir will result in a decrease in the total minimum-horizontal stress. The magnitude of changes in stress state with net changes in pore pressure is dependent on local field conditions and cannot be accurately predicted by the uniaxial strain model that is commonly used by the petroleum industry.

  13. Knoop Hardness - Apparent Yield Stress Relationship in Ceramics

    SciTech Connect (OSTI)

    Swab, Jeffrey J; LaSalvia, Jerry; Wereszczak, Andrew A; Strong, Kevin T; Danna, Dominic; Ragan, Meredith E; Ritt, Patrick J

    2012-01-01

    In Tabor's classical studies of the deformation of metals, the yield stress (Y) and hardness (H) were shown to be related according to H/Y {approx} 3 for complete or fully plastic deformation. Since then it has been anecdotally shown for ceramics that this ratio is <3. Interest exists to explore this further so Hertzian indentation was used to measure the apparent yield stress of numerous ceramics and metals and their results were compared with each material's load-dependent Knoop hardness. The evaluated ceramics included standard reference materials for hardness (silicon nitride and tungsten carbide), silicon carbide, alumina, and glass. Several steel compositions were also tested for comparison. Knoop hardness measurements at 19.6 N (i.e., toward 'complete or fully plastic deformation'), showed that 2 < H/Y < 3 for the metals and 0.8 < H/Y < 1.8 for the glasses and ceramics. Being that H/Y {ne} 3 for the ceramics indicates that Tabor's analysis is either not applicable to ceramics or that full plastic deformation is not achieved with a Knoop indentation or both.

  14. Estimation of uncertainty for contour method residual stress measurements

    SciTech Connect (OSTI)

    Olson, Mitchell D.; DeWald, Adrian T.; Prime, Michael B.; Hill, Michael R.

    2014-12-03

    This paper describes a methodology for the estimation of measurement uncertainty for the contour method, where the contour method is an experimental technique for measuring a two-dimensional map of residual stress over a plane. Random error sources including the error arising from noise in displacement measurements and the smoothing of the displacement surfaces are accounted for in the uncertainty analysis. The output is a two-dimensional, spatially varying uncertainty estimate such that every point on the cross-section where residual stress is determined has a corresponding uncertainty value. Both numerical and physical experiments are reported, which are used to support the usefulness of the proposed uncertainty estimator. The uncertainty estimator shows the contour method to have larger uncertainty near the perimeter of the measurement plane. For the experiments, which were performed on a quenched aluminum bar with a cross section of 51 76 mm, the estimated uncertainty was approximately 5 MPa (?/E = 7 10??) over the majority of the cross-section, with localized areas of higher uncertainty, up to 10 MPa (?/E = 14 10??).

  15. Monitoring pipe line stress due to ground displacement

    SciTech Connect (OSTI)

    Greenwood, J.H. Jr.

    1986-04-01

    Northwest Pipeline Corp. has a large-diameter natural gas pipe line system from Ignacio, Colo., to Sumas, Wash. At Douglas Pass in Colorado, large landslides required several sections of the line to be relocated outside the slide areas: 4,400 ft of new line in April 1962 and 3,200 ft in March 1963. No serious disruptions occurred for the next 16 years. Then in July 1979, some 1,200 ft had to be relocated. From 1980 to date, many landslides in the Douglas Pass area have caused new deformations, with the springs of 1983 and 1984 being the worst years. In 1980, Northwest Pipeline began engineering and geotechnical studies of the landslide problems. These led to instrumentation and pipe monitoring which indicated that pipe failure can be predicted and prevented if important slope deformations or increases in pipe stresses are detected early enough to implement some mitigating measures. Excavation of the pipe to relieve the stresses was used in most cases. The method was so successful that no pipe failure occurred in 1984 within instrumented sections, in spite of the exceptionally bad climatic conditions experienced.

  16. Analysis of Alloy 600 and X-750 stress corrosion cracks

    SciTech Connect (OSTI)

    Thompson, C.D.; Lewis, N.; Krasodomski, H.

    1993-06-01

    A few months ago, KAPL evidence supported the view that Primary or Pure Water Stress Corrosion Cracking (PWSCC) of Alloy 600 results from a hydrogen mechanism. Figure 1 shows an Analytical Electron Microscope (AEM) analysis of a stress corrosion crack (SCC) crack in an A600 split tube U-bend specimen exposed to primary water at 338{degree}C (640{degrees}F) for 462 days. The features which appear to confirm a hydrogen mechanism are: (1) A very narrow (< 200 {angstrom}) crack with a sharp tip, nearly free of deposits. (2) No evidence of severe plastic deformation in the region immediately ahead of the crack tip. (3) A line of small voids preceding the main crack tip, of which the largest is about 5 x 10{sup {minus}6} cm in length. Shen and Shewmon proposed that PWSCC of Alloy 600 occurs due to small microvoids ahead of a main crack tip. The hypothesis is that such voids result from pockets of methane gas formed by the reaction of atomic hydrogen with carbon in the base metal. The voids are about 10 x 10{sup {minus}6} cm diameter, approximately a factor of 2 larger than the largest voids.

  17. Estimation of uncertainty for contour method residual stress measurements

    SciTech Connect (OSTI)

    Olson, Mitchell D.; DeWald, Adrian T.; Prime, Michael B.; Hill, Michael R.

    2014-12-03

    This paper describes a methodology for the estimation of measurement uncertainty for the contour method, where the contour method is an experimental technique for measuring a two-dimensional map of residual stress over a plane. Random error sources including the error arising from noise in displacement measurements and the smoothing of the displacement surfaces are accounted for in the uncertainty analysis. The output is a two-dimensional, spatially varying uncertainty estimate such that every point on the cross-section where residual stress is determined has a corresponding uncertainty value. Both numerical and physical experiments are reported, which are used to support the usefulness of the proposed uncertainty estimator. The uncertainty estimator shows the contour method to have larger uncertainty near the perimeter of the measurement plane. For the experiments, which were performed on a quenched aluminum bar with a cross section of 51 × 76 mm, the estimated uncertainty was approximately 5 MPa (σ/E = 7 · 10⁻⁵) over the majority of the cross-section, with localized areas of higher uncertainty, up to 10 MPa (σ/E = 14 · 10⁻⁵).

  18. Estimation of uncertainty for contour method residual stress measurements

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Olson, Mitchell D.; DeWald, Adrian T.; Prime, Michael B.; Hill, Michael R.

    2014-12-03

    This paper describes a methodology for the estimation of measurement uncertainty for the contour method, where the contour method is an experimental technique for measuring a two-dimensional map of residual stress over a plane. Random error sources including the error arising from noise in displacement measurements and the smoothing of the displacement surfaces are accounted for in the uncertainty analysis. The output is a two-dimensional, spatially varying uncertainty estimate such that every point on the cross-section where residual stress is determined has a corresponding uncertainty value. Both numerical and physical experiments are reported, which are used to support the usefulnessmore » of the proposed uncertainty estimator. The uncertainty estimator shows the contour method to have larger uncertainty near the perimeter of the measurement plane. For the experiments, which were performed on a quenched aluminum bar with a cross section of 51 × 76 mm, the estimated uncertainty was approximately 5 MPa (σ/E = 7 · 10⁻⁵) over the majority of the cross-section, with localized areas of higher uncertainty, up to 10 MPa (σ/E = 14 · 10⁻⁵).« less

  19. Stress dependent oxidation of sputtered niobium and effects on superconductivity

    SciTech Connect (OSTI)

    David Henry, M. Wolfley, Steve; Monson, Todd; Clark, Blythe G.; Shaner, Eric; Jarecki, Robert

    2014-02-28

    We report on the suppression of room temperature oxidation of DC sputtered niobium films and the effects upon the superconductive transition temperature, T{sub c}. Niobium was sputter-deposited on silicon dioxide coated 150?mm wafers and permitted to oxidize at room temperature and pressure for up to two years. Resistivity and stress measurements indicate that tensile films greater than 400?MPa resist bulk oxidation with measurements using transmission electron microscope, electron dispersive X-ray spectroscopy, x-ray photoelectric spectroscopy, and secondary ion mass spectrometry confirming this result. Although a surface oxide, Nb{sub 2}O{sub 5}, consumed the top 610?nm, we measure less than 1 at.% oxygen and nitrogen in the bulk of the films after the oxidation period. T{sub c} measurements using a SQUID magnetometer indicate that the tensile films maintained a T{sub c} approaching the dirty superconductive limit of 8.4?K after two years of oxidation while maintaining room temperature sheet resistance. This work demonstrates that control over niobium film stress during deposition can prevent bulk oxidation by limiting the vertical grain boundaries ability to oxidize, prolonging the superconductive properties of sputtered niobium when exposed to atmosphere.

  20. Optical method for the determination of stress in thin films

    DOE Patents [OSTI]

    Maris, H.J.

    1999-01-26

    A method and optical system is disclosed for measuring an amount of stress in a film layer disposed over a substrate. The method includes steps of: (A) applying a sequence of optical pump pulses to the film layer, individual ones of said optical pump pulses inducing a propagating strain pulse in the film layer, and for each of the optical pump pulses, applying at least one optical probe pulse, the optical probe pulses being applied with different time delays after the application of the corresponding optical probe pulses; (B) detecting variations in an intensity of a reflection of portions of the optical probe pulses, the variations being due at least in part to the propagation of the strain pulse in the film layer; (C) determining, from the detected intensity variations, a sound velocity in the film layer; and (D) calculating, using the determined sound velocity, the amount of stress in the film layer. In one embodiment of this invention the step of detecting measures a period of an oscillation in the intensity of the reflection of portions of the optical probe pulses, while in another embodiment the step of detecting measures a change in intensity of the reflection of portions of the optical probe pulses and determines a time at which the propagating strain pulse reflects from a boundary of the film layer. 16 figs.

  1. Graphite having improved thermal stress resistance and method of preparation

    DOE Patents [OSTI]

    Kennedy, Charles R.

    1980-01-01

    An improved method for fabricating a graphite article comprises the steps of impregnating a coke article by first heating the coke article in contact with a thermoplastic pitch at a temperature within the range of 250.degree.-300.degree. C. at a pressure within the range of 200-2000 psig for at least 4-10 hours and then heating said article at a temperature within the range of 450.degree.-485.degree. C. at a pressure of 200-2000 psig for about 16-24 hours to provide an impregnated article; heating the impregnated article for sufficient time to carbonize the impregnant to provide a second coke article, and graphitizing the second coke article. A graphite having improved thermal stress resistance results when the coke to be impregnated contains 1-3 wt.% sulfur and no added puffing inhibitors. An additional improvement in thermal stress resistance is achieved when the second coke article is heated above about 1400.degree. C. at a rate of at least 10.degree. C./minute to a temperature above the puffing temperature.

  2. Optical method for the determination of stress in thin films

    DOE Patents [OSTI]

    Maris, Humphrey J.

    1999-01-01

    A method and optical system is disclosed for measuring an amount of stress in a film layer disposed over a substrate. The method includes steps of: (A) applying a sequence of optical pump pulses to the film layer, individual ones of said optical pump pulses inducing a propagating strain pulse in the film layer, and for each of the optical pump pulses, applying at least one optical probe pulse, the optical probe pulses being applied with different time delays after the application of the corresponding optical probe pulses; (B) detecting variations in an intensity of a reflection of portions of the optical probe pulses, the variations being due at least in part to the propagation of the strain pulse in the film layer; (C) determining, from the detected intensity variations, a sound velocity in the film layer; and (D) calculating, using the determined sound velocity, the amount of stress in the film layer. In one embodiment of this invention the step of detecting measures a period of an oscillation in the intensity of the reflection of portions of the optical probe pulses, while in another embodiment the step of detecting measures a change in intensity of the reflection of portions of the optical probe pulses and determines a time at which the propagating strain pulse reflects from a boundary of the film layer.

  3. Finite element residual stress analysis of induction heating bended ferritic steel piping

    SciTech Connect (OSTI)

    Kima, Jong Sung; Kim, Kyoung-Soo; Oh, Young-Jin; Chang, Hyung-Young; Park, Heung-Bae

    2014-10-06

    Recently, there is a trend to apply the piping bended by induction heating process to nuclear power plants. Residual stress can be generated due to thermo-mechanical mechanism during the induction heating bending process. It is well-known that the residual stress has important effect on crack initiation and growth. The previous studies have focused on the thickness variation. In part, some studies were performed for residual stress evaluation of the austenitic stainless steel piping bended by induction heating. It is difficult to find the residual stresses of the ferritic steel piping bended by the induction heating. The study assessed the residual stresses of induction heating bended ferriticsteel piping via finite element analysis. As a result, it was identified that high residual stresses are generated on local outersurface region of the induction heating bended ferritic piping.

  4. Osmotic stress-induced putrescine accumulation as a mechanism of ammonia detoxification in oat leaves

    SciTech Connect (OSTI)

    Slocum, R.D. ); Weinstein, L.H. )

    1990-05-01

    In osmotically-stressed oat leaves, putrescine (Put) accumulates to very high levels within several hours of the onset of stress. It has previously been shown that increased Put levels result from induction of the arginine decarboxylase (ADC) pathway. In non-stressed leaves, this response can be mimicked to varying degrees by exogenous NH{sub 3}, glutamate or ornithine. The activities of GS/GOGAT, ornithine transcarbamylase (OTC) and ADC, and levels of NH{sub 3} and Put all increase in response to stress. Incorporation of (U-{sup 14}C)-glutamate into Put is greatly increased in stressed leaves and is blocked by difluoromethylarginine, a specific, irreversible inhibitor of ADC. These findings suggest that stress-induced Put accumulation results from (1) the assimilation of NH{sub 3} nitrogen to glutamate via GS/GOGAT, (2) glutamate utilization in de novo ornithine and arginine biosynthesis and (3) incorporation of arginine into Put via the ADC pathway.

  5. Residual and applied stress analysis of an alloy 600 row 1 U-bend: Final report

    SciTech Connect (OSTI)

    Ruud, C.O.

    1987-09-01

    Residual stresses in Inconel alloy 600, row 1, U-bend tubes, used in heat exchanges in nuclear reactors, were studied using an advanced x-ray diffraction instrument. Both axial and circumferential (hoop) stresses on the extrados, intrados, and flanks on the O.D. surface of several U-bends were mapped. The I.D. surface residual stresses at the extrados of the U-bend were mapped on one tube and subsurface stress measurements were made on the I.D. and O.D. surfaces of that tube. Service loads were simulated on one tube to ascertain combined effect of residual and applied stresses. Data from wall thickness and profilometry measurements were also correlated with residual stress measurements. 21 refs., 42 figs.

  6. Virtual Institute of Microbial Stress and Survival: Deduction of Stress Response Pathways in Metal and Radionuclide Reducing Microorganisms

    SciTech Connect (OSTI)

    2004-04-17

    The projects application goals are to: (1) To understand bacterial stress-response to the unique stressors in metal/radionuclide contamination sites; (2) To turn this understanding into a quantitative, data-driven model for exploring policies for natural and biostimulatory bioremediation; (3) To implement proposed policies in the field and compare results to model predictions; and (4) Close the experimental/computation cycle by using discrepancies between models and predictions to drive new measurements and construction of new models. The projects science goals are to: (1) Compare physiological and molecular response of three target microorganisms to environmental perturbation; (2) Deduce the underlying regulatory pathways that control these responses through analysis of phenotype, functional genomic, and molecular interaction data; (3) Use differences in the cellular responses among the target organisms to understand niche specific adaptations of the stress and metal reduction pathways; (4) From this analysis derive an understanding of the mechanisms of pathway evolution in the environment; and (5) Ultimately, derive dynamical models for the control of these pathways to predict how natural stimulation can optimize growth and metal reduction efficiency at field sites.

  7. Determination of nonuniform residual stress using the ring-core method

    SciTech Connect (OSTI)

    Ajovalasit, A.; Petrucci, G.; Zuccarello, B.

    1996-04-01

    This paper considers residual stress analysis using the ring-core method. In particular, the so-called integral equation method is applied to evaluate nonuniform residual stress fields. The proposed method overcomes typical drawbacks of the incremental strain method which lead to incorrect results for strongly varying stress fields. The experimental results obtained with a specimen subjected to a bending load confirm the theoretical predictions.

  8. As OPEC Ministers Meet, Secretary Chu Stresses the Importance of Energy

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

    Independence | Department of Energy As OPEC Ministers Meet, Secretary Chu Stresses the Importance of Energy Independence As OPEC Ministers Meet, Secretary Chu Stresses the Importance of Energy Independence March 15, 2009 - 12:00am Addthis Washington, DC - As OPEC ministers held a meeting in Vienna Sunday, U.S. Energy Secretary Steven Chu again stressed the need for energy independence and called for global cooperation on energy, economic and climate challenges. "While OPEC's actions are

  9. Relationship between Structural and Stress Relaxation in a Block-Copolymer Melt

    SciTech Connect (OSTI)

    Patel, Amish J.; Narayanan, Suresh; Sandy, Alec; Mochrie, Simon G. J.; Garetz, Bruce A.; Watanabe, Hiroshi; Balsara, Nitash P.

    2006-06-30

    The relationship between structural relaxation on molecular length scales and macroscopic stress relaxation was explored in a disordered block-copolymer melt. Experiments show that the structural relaxation time, measured by x-ray photon correlation spectroscopy is larger than the terminal stress relaxation time, measured by rheology, by factors as large as 100. We demonstrate that the structural relaxation data are dominated by the diffusion of intact micelles while the stress relaxation data are dominated by contributions due to disordered concentration fluctuations.

  10. Thin Silicon MEMS Contact-Stress Sensor (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Conference: Thin Silicon MEMS Contact-Stress Sensor Citation Details In-Document Search Title: Thin Silicon MEMS Contact-Stress Sensor This thin, MEMS contact-stress (CS) sensor continuously and accurately measures time-varying, solid interface loads in embedded systems over tens of thousands of load cycles. Unlike all other interface load sensors, the CS sensor is extremely thin (< 150 {micro}m), provides accurate, high-speed measurements, and exhibits good stability over time with no loss

  11. The influence of quench sensitivity on residual stresses in the aluminium alloys 7010 and 7075

    SciTech Connect (OSTI)

    Robinson, J.S.; Tanner, D.A.; Truman, C.E.; Paradowska, A.M.; Wimpory, R.C.

    2012-03-15

    The most critical stage in the heat treatment of high strength aluminium alloys is the rapid cooling necessary to form a supersaturated solid solution. A disadvantage of quenching is that the thermal gradients can be sufficient to cause inhomogeneous plastic deformation which in turn leads to the development of large residual stresses. Two 215 mm thick rectilinear forgings have been made from 7000 series alloys with widely different quench sensitivity to determine if solute loss in the form of precipitation during quenching can significantly affect residual stress magnitudes. The forgings were heat treated and immersion quenched using cold water to produce large magnitude residual stresses. The through thickness residual stresses were measured by neutron diffraction and incremental deep hole drilling. The distribution of residual stresses was found to be similar for both alloys varying from highly triaxial and tensile in the interior, to a state of biaxial compression in the surface. The 7010 forging exhibited larger tensile stresses in the interior. The microstructural variation from surface to centre for both forgings was determined using optical and transmission electron microscopy. These observations were used to confirm the origin of the hardness variation measured through the forging thickness. When the microstructural changes were accounted for in the through thickness lattice parameter, the residual stresses in the two forgings were found to be very similar. Solute loss in the 7075 forging appeared to have no significant effect on the residual stress magnitudes when compared to 7010. - Highlights: Black-Right-Pointing-Pointer Through thickness residual stress measurements made on large Al alloy forgings. Black-Right-Pointing-Pointer Residual stress characterised using neutron diffraction and deep hole drilling. Black-Right-Pointing-Pointer Biaxial compressive surface and triaxial subsurface residual stresses. Black-Right-Pointing-Pointer Quench sensitivity

  12. Achieving reversibility of ultra-high mechanical stress by hydrogen loading of thin films

    SciTech Connect (OSTI)

    Hamm, M.; Burlaka, V.; Wagner, S.; Pundt, A.

    2015-06-15

    Nano-materials are commonly stabilized by supports to maintain their desired shape and size. When these nano-materials take up interstitial atoms, this attachment to the support induces mechanical stresses. These stresses can be high when the support is rigid. High stress in the nano-material is typically released by delamination from the support or by the generation of defects, e.g., dislocations. As high mechanical stress can be beneficial for tuning the nano-materials properties, it is of general interest to deduce how real high mechanical stress can be gained. Here, we show that below a threshold nano-material size, dislocation formation can be completely suppressed and, when delamination is inhibited, even the ultrahigh stress values of the linear elastic limit can be reached. Specifically, for hydrogen solved in epitaxial niobium films on sapphire substrate supports a threshold film thickness of 6 nm was found and mechanical stress of up to (−10 ± 1) GPa was reached. This finding is of basic interest for hydrogen energy applications, as the hydride stability in metals itself is affected by mechanical stress. Thus, tuning of the mechanical stress-state in nano-materials may lead to improved storage properties of nano-sized materials.

  13. In-situ stress relief of expanded Alloy 600 steam generator tubing

    SciTech Connect (OSTI)

    Woodward, J.; van Rooyen, D.; McIlree, A.R.

    1984-01-01

    Stress corrosion cracking is the most common cause of defects in steam generator tubing. Methods of averting tubing damage are constantly under review. This paper concentrates on the problem of intergranular stress corrosion cracking, initiated on the primary side, in the expansion transition region of roller expanded Alloy 600 tubing. In general it is believed that residual stresses, arising from the expansion process, are the cause of the problem. The work reported here discusses the identification and implementation of an optimal, in-situ stress relief treatment.

  14. Thin Silicon MEMS Contact-Stress Sensor (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    thin, MEMS contact-stress (CS) sensor continuously and accurately measures time-varying, ... and exhibits good stability over time with no loss of calibration with load cycling. ...

  15. Thin Silicon MEMS Contact-Stress Sensor (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    Conference: Thin Silicon MEMS Contact-Stress Sensor Citation Details In-Document Search ... and exhibits good stability over time with no loss of calibration with load cycling. ...

  16. Effects of weld residual stresses on crack-opening area analysis of pipes for LBB applications

    SciTech Connect (OSTI)

    Dong, P.; Rahman, S.; Wilkowski, G.

    1997-04-01

    This paper summarizes four different studies undertaken to evaluate the effects of weld residual stresses on the crack-opening behavior of a circumferential through-wall crack in the center of a girth weld. The effect of weld residual stress on the crack-opening-area and leak-rate analyses of a pipe is not well understood. There are no simple analyses to account for these effects, and, therefore, they are frequently neglected. The four studies involved the following efforts: (1) Full-field thermoplastic finite element residual stress analyses of a crack in the center of a girth weld, (2) A comparison of the crack-opening displacements from a full-field thermoplastic residual stress analysis with a crack-face pressure elastic stress analysis to determine the residual stress effects on the crack-opening displacement, (3) The effects of hydrostatic testing on the residual stresses and the resulting crack-opening displacement, and (4) The effect of residual stresses on crack-opening displacement with different normal operating stresses.

  17. Structural transformations in Mn{sub 2}NiGa due to residual stress

    SciTech Connect (OSTI)

    Singh, Sanjay; Maniraj, M.; D'Souza, S. W.; Barman, S. R.; Ranjan, R.

    2010-02-22

    Powder x-ray diffraction study of Mn{sub 2}NiGa ferromagnetic shape memory alloy shows the existence of a 7M monoclinic modulated structure at room temperature (RT). The structure of Mn{sub 2}NiGa is found to be highly dependent on residual stress. For higher stress, the structure is tetragonal at RT, and for intermediate stress it is 7M monoclinic. However, only when the stress is considerably relaxed, the structure is cubic, as is expected at RT since the martensitic transition temperature is 230 K.

  18. Thin Silicon MEMS Contact-Stress Sensor (Conference) | SciTech...

    Office of Scientific and Technical Information (OSTI)

    sensor continuously and accurately measures time-varying, solid interface loads over tens of thousands of load cycles. The contact-stress sensor is extremely thin (150 mum) ...

  19. Thermal Stress and Reliability for Advanced Power Electronics and Electric Machines (Presentation)

    SciTech Connect (OSTI)

    O'Keefe, M. P.

    2009-05-01

    This presentation gives an overview of NREL's Thermal Stress and Reliability Project work from October 2007 to March 2009 with an emphasis on activity during 2008/2009.

  20. Stress and Sealing Performance Analysis of Containment Vessel

    SciTech Connect (OSTI)

    WU, TSU-TE

    2005-05-24

    This paper presents a numerical technique for analyzing the containment vessel subjected to the combined loading of closure-bolt torque and internal pressure. The detailed stress distributions in the O-rings generated by both the torque load and the internal pressure can be evaluated by using this method. Consequently, the sealing performance of the O-rings can be determined. The material of the O-rings can be represented by any available constitutive equation for hyperelastic material. In the numerical calculation of this paper, the form of the Mooney-Rivlin strain energy potential is used. The technique treats both the preloading process of bolt tightening and the application of internal pressure as slow dynamic loads. Consequently, the problem can be evaluated using explicit numerical integration scheme.

  1. Cold stress on Russian territory during last global warming

    SciTech Connect (OSTI)

    Vinogradov, V.V.

    1996-12-31

    A great part of Russian territory is characterized by climate discomfort of life. In winter cold stress covers nearly all territory. The purpose of this work is to learn how the climatic discomfort of life is affected by climate change. The effect of global warming for the period 1981--1990 on geographical distribution of bioclimatic indexes by seasons (compared with average figures) is analyzed. Indexes of enthalpy, dry cooling, wind chill, wet cooling, effective temperature, physiological deficit index for monthly average figures were calculated and the data bank for the period 1981--1990 was made up. The indexes of enthalpy, wet cooling, and dry cooling according to Bodman were chosen as the most informative and independent. Maps of the climatic indexes taking into account temperature, humidity and wind speed were made up on the basis of the calculated figures.

  2. Primary Water Stress Corrosion Crack Morphology and Nondestructive Evaluation Reliability

    SciTech Connect (OSTI)

    Doctor, Steven R.; Schuster, George J.; Anderson, Michael T.

    2004-12-01

    A research program on primary stress corrosion crack (PWSCC) is being conducted by Pacific Northwest National Laboratory (PNNL). In this program, the material degradation problem in Alloys 600, 182, and 82 is being investigated with objectives that include compling a knowledge base on all cracking in nickel based materials at all degradation sites in nuclear power plants, assessing NDE methods using mockups to quantify the detection, sizing, and using mockups to quantify the detection sizing and characterization of tight cracks, and determining the role of welding processes in degradation. In this paper, the resuts of the initial literature searchs are presented. The relevant data on crack properties such as shape and orientation are presented and their impace on nondestructive evaluation (NDE) reliability is discussed.

  3. Stress Corrosion Cracking Issues in Light Metals for Automotive Applications

    SciTech Connect (OSTI)

    Jones, Russell H.; Danielson, Michael J.; Baer, Donald R.; Windisch, Charles F.; Vetrano, John S.; Edwards, Daniel J.

    2000-12-31

    The Partnership for New Generation Vehicle has the goal of producing lightweight automobiles that achieve 80 mpg. To accomplish this will require liberal use of Al and Mg alloys such as AA5083 and AZ91D. The corrosion and stress corrosion of alloy AA5083 is controlled by the precipitation of the b-phase (Al3Mg2) at grain boundaries and by the precipitation of the g-phase (Mg17Al12) in AZ91D. The b-phase is anodic to the Al matrix while the g-phase is cathodic to the Mg matrix. The effects of crack propagation along grain boundaries with electrochemically active particles is a key factor in the SCC performance of these materials.

  4. Relationships between stress corrosion cracking tests and utility operating experience

    SciTech Connect (OSTI)

    Baum, Allen

    1999-10-22

    Several utility steam generator and stress corrosion cracking databases are synthesized with the view of identifying the crevice chemistry that is most consistent with the plant cracking data. Superheated steam and neutral solution environments are found to be inconsistent with the large variations in the observed SCC between different plants, different support plates within a plant, and different crevice locations. While the eddy current response of laboratory tests performed with caustic chemistries approximates the response of the most extensively affected steam generator tubes, the crack propagation kinetics in these tests differ horn plant experience. The observations suggest that there is a gradual conversion of the environment responsible for most steam generator ODSCC from a concentrated, alkaline-forming solution to a progressively more steam-enriched environment.

  5. Mechanical Properties of Gels; Stress from Confined Fluids

    SciTech Connect (OSTI)

    George W. Scherer

    2009-12-01

    Abstract for Grant DE-FG02-97ER45642 Period: 1997-2002 Mechanical Properties of Gels 2002-2008 Stress from Confined Fluids Principal investigator: Prof. George W. Scherer Dept. Civil & Env. Eng./PRISM Eng. Quad. E-319 Princeton, NJ 08544 USA Recipient organization: Trustees of Princeton University 4 New South Princeton, NJ 08544 USA Abstract: The initial stage of this project, entitled Mechanical Properties of Gels, was dedicated to characterizing and explaining the properties of inorganic gels. Such materials, made by sol-gel processing, are of interest for fabrication of films, fibers, optical devices, advanced insulation and other uses. However, their poor mechanical properties are an impediment in some applications, so understanding the origin of these properties could lead to enhanced performance. Novel experimental methods were developed and applied to measure the stiffness and permeability of gels and aerogels. Numerical simulations were developed to reproduce the growth process of the gels, resulting in structures whose mechanical properties matched the measurements. The models showed that the gels are formed by the growth of relatively robust clusters of molecules that are joined by tenuous links whose compliance compromises the stiffness of the structure. Therefore, synthetic methods that enhance the links could significantly increase the rigidity of such gels. The next stage of the project focused on Stress from Confined Fluids. The first problem of interest was the enhanced thermal expansion coefficient of water that we measured in the nanometric pores of cement paste. This could have a deleterious effect on the resistance of concrete to rapid heating in fires, because the excessive thermal expansion of water in the pores of the concrete could lead to spalling and collapse. A series of experiments demonstrated that the expansion of water increases as the pore size decreases. To explain this behavior, we undertook a collaboration with Prof. Stephen

  6. Alkaline intergranular corrosion and stress corrosion cracking of Alloy 600

    SciTech Connect (OSTI)

    Nagano, N.

    1996-12-31

    Intergranular corrosion (IGC), often termed IGA, and intergranular stress corrosion cracking (IGSCC) have continued to occur on mill-annealed (MA) Alloy 600 tubing in the secondary side of steam generators, which are still serious corrosion instances in operating pressurized water reactors. The IGC and IGSCC phenomena have occurred on MA Alloy 600 at the crevice between the tube and tube support plate, in which a high concentration of caustic solution is formed under dry and wet conditions at high temperature. A review of technical articles has been performed concerning environmental and metallurgical factors affecting the IGC and IGSCC, and their mechanistic aspects. A combination of IGC and IGSCC, one of the most common modes of corrosion on the secondary side of steam generators, occurs in a specific potential region, at the active-passive transition potential, in a concentrated caustic solution at elevated temperature. The anodic dissolution of Alloy 600 increases as the temperature of caustic solutions is increased. The corrosion rate for each constituent of Alloy 600 such as nickel, chromium, iron or chromium carbide is influenced differently by temperature, resulting in various effects on the characteristics of corrosion protective surface films. Increase in chromium content and thermal treatment at 700 C are beneficial for IGC and IGSCC resistance. IGC is intergranular corrosion, and IGSCC is initiated above a critical applied stress. Grain boundary chromium carbides such as Cr{sub 7}C{sub 3} and Cr{sub 23}C{sub 6} have been formed to increase resistance to IGC and IGSCC. Several theories have been proposed concerning the roles of chromium carbides at grain boundaries. Some specific theories are focused on in this paper with supporting data.

  7. BAG3 affects the nucleocytoplasmic shuttling of HSF1 upon heat stress

    SciTech Connect (OSTI)

    Jin, Young-Hee; Ahn, Sang-Gun; Kim, Soo-A.

    2015-08-21

    Bcl2-associated athoanogene (BAG) 3 is a member of the co-chaperone BAG family. It is induced by stressful stimuli such as heat shock and heavy metals, and it regulates cellular adaptive responses against stressful conditions. In this study, we identified a novel role for BAG3 in regulating the nuclear shuttling of HSF1 during heat stress. The expression level of BAG3 was induced by heat stress in HeLa cells. Interestingly, BAG3 rapidly translocalized to the nucleus upon heat stress. Immunoprecipitation assay showed that BAG3 interacts with HSF1 under normal and stressed conditions and co-translocalizes to the nucleus upon heat stress. We also demonstrated that BAG3 interacts with HSF1 via its BAG domain. Over-expression of BAG3 down-regulates the level of nuclear HSF1 by exporting it to the cytoplasm during the recovery period. Depletion of BAG3 using siRNA results in reduced nuclear HSF1 and decreased Hsp70 promoter activity. BAG3 in MEF(hsf1{sup −/−}) cells actively translocalizes to the nucleus upon heat stress suggesting that BAG3 plays a key role in the processing of the nucleocytoplasmic shuttling of HSF1 upon heat stress. - Highlights: • The expression level of BAG3 is induced by heat stress. • BAG3 translocates to the nucleus upon heat stress. • BAG3 interacts with HSF1 and co-localizes to the nucleus. • BAG3 is a key regulator for HSF1 nuclear shuttling.

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

    DOE Patents [OSTI]

    Green, David J.; Sglavo, Vincenzo M.; Tandon, Rajan

    2003-02-11

    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.

  9. Final Report. Geothermal Dual Acoustic Tool for Measurement of Rock Stress

    SciTech Connect (OSTI)

    Normann, Randy A

    2014-12-01

    This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

  10. Overexpression of Late Embryogenesis Abundant 14 enhances Arabidopsis salt stress tolerance

    SciTech Connect (OSTI)

    Jia, Fengjuan Qi, Shengdong Li, Hui Liu, Pu Li, Pengcheng Wu, Changai Zheng, Chengchao Huang, Jinguang

    2014-11-28

    Highlights: It is the first time to investigate the biological function of AtLEA14 in salt stress response. AtLEA14 enhances the salt stress tolerance both in Arabidopsis and yeast. AtLEA14 responses to salt stress by stabilizing AtPP2-B11, an E3 ligase, under normal or salt stress conditions. - Abstract: Late embryogenesis abundant (LEA) proteins are implicated in various abiotic stresses in higher plants. In this study, we identified a LEA protein from Arabidopsis thaliana, AtLEA14, which was ubiquitously expressed in different tissues and remarkably induced with increased duration of salt treatment. Subcellular distribution analysis demonstrated that AtLEA14 was mainly localized in the cytoplasm. Transgenic Arabidopsis and yeast overexpressing AtLEA14 all exhibited enhanced tolerance to high salinity. The transcripts of salt stress-responsive marker genes (COR15a, KIN1, RD29B and ERD10) were overactivated in AtLEA14 overexpressing lines compared with those in wild type plants under normal or salt stress conditions. In vivo and in vitro analysis showed that AtLEA14 could effectively stabilize AtPP2-B11, an important E3 ligase. These results suggested that AtLEA14 had important protective functions under salt stress conditions in Arabidopsis.

  11. Final Report: Geothermal Dual Acoustic Tool for Measurement of Rock Stress

    SciTech Connect (OSTI)

    Normann, Randy A.

    2014-12-01

    This paper outlines the technology need for a rock formation stress measurement in future EGS wells. This paper reports on the results of work undertaken under a Phase I, DOE/SBIR on the feasibility to build an acoustic well logging tool for measuring rock formation stress.

  12. Laser Peening of Alloy 600 to Improve Intergranular Stress Corrosion Cracking Resistance in Power Plants

    SciTech Connect (OSTI)

    Chen, H; Rankin, J; Hackel, L; Frederick, G; Hickling, J; Findlan, S

    2004-04-20

    Laser peening is an emerging modern process that impresses a compressive stress into the surface of metals or alloys. This treatment can reduce the rate of intergranular stress corrosion cracking and fatigue cracking in structural metals or Alloy 600 needed for nuclear power plants.

  13. Validation Specimen for Contour Method Extension to Multiple Residual Stress Components

    SciTech Connect (OSTI)

    Pagliaro, Pierluigi; Prime, Michael B; Zuccarello, B; Clausen, Bjorn; Watkins, Thomas R

    2007-01-01

    A new theoretical development of the contour method, that allow the user to measure the three normal residual stress components on cross sections of a generic mechanical part, is presented. To validate such a theoretical development, a residual stress test specimen was properly designed, fabricated and then tested with different experimental techniques.

  14. Waterflood improvement in the Permian Basin: Impact of in-situ-stress evaluations

    SciTech Connect (OSTI)

    Nolen-Hoeksema, R.C.; Avasthi, J.M. ); Pape, W.C. ); El Rabaa, A.W. )

    1994-11-01

    The authors evaluated in-situ-stress magnitudes and directions to support waterflood improvement programs in McElroy field and North Westbrook Unit. In-situ-stress and hydraulic-fracture directions coincided with directional floodwater effects. This information contributed to successful waterflood realignment programs.

  15. Stress-dependent recovery of point defects in deformed aluminum: An acoustic-damping study

    SciTech Connect (OSTI)

    Ogi, H.; Tsujimoto, A.; Hirao, M.; Ledbetter, H.

    1999-10-26

    The stress dependence of point-defect diffusion to dislocations in a 99.99% polycrystalline aluminum was studied using shear-wave attenuation and phase velocity. By holding the stress after deformation, attenuation and velocity approach their nonstressed values. The holding stress was varied between 0 and 12 MPa, after applying a 15 MPa compressive stress. Time-independent attenuation and stress-induced velocity change were introduced into the Granato-Hikata-Luecke theory, which first established the change of attenuation and velocity caused by the point-defect diffusion to dislocations. Good agreement was found between measurements and the modified theory. The stress dependence of the recovery rate was interpreted as a reduction of the migration energy of point defects diffusing to dislocations, and the activation volume was calculated for uniaxial stress. Electromagnetic acoustic resonance (EMAR) was used for the measurements. Being noncontact and highly sensitive, EMAR permitted detailed measurement of the attenuation and velocity evolutions during the unloading-holding stress sequence.

  16. Study of the effect of the stress on CdTe nuclear detectors

    SciTech Connect (OSTI)

    Ayoub, M.; Radley, I.; Mullins, J. T.; Hage-Ali, M.

    2013-09-14

    CdTe detectors are commonly used for X and ? ray applications. The performance of these detectors is strongly affected by different types of mechanical stress; such as that caused by differential expansion between the semiconductor and its intimate metallic contacts and that caused by applied pressure during the bonding process. The aim of this work was to study the effects of stress on the performance of CdTe detectors. A difference in expansion coefficients induces transverse stress under the metallic contact, while contact pressure induces longitudinal stress. These stresses have been simulated by applying known static pressures. For the longitudinal case, the pressure was applied directly to the metallic contact; while in the transverse case, it was applied to the side. We have studied the effect of longitudinal and transverse stresses on the electrical characteristics including leakage current measurements and ?-ray detection performance. We have also investigated induced defects, their nature, activation energies, cross sections, and concentrations under the applied stress by using photo-induced current transient spectroscopy and thermoelectric effect spectroscopy techniques. The operational stress limit is also given.

  17. Clostridium thermocellum Transcriptomic Profiles after Exposure to Furfural or Heat Stress

    SciTech Connect (OSTI)

    Wilson, Charlotte M; Yang, Shihui; Rodriguez, Jr., Miguel; Ma, Qin; Johnson, Courtney M; Dice, Lezlee T; Xu, Ying; Brown, Steven D

    2013-01-01

    Background The thermophilic anaerobe Clostridium thermocellum is a candidate consolidated bioprocessing (CBP)biocatalyst for cellulosic ethanol production. It is capable of both cellulose solubilization and its fermentation to produce lignocellulosic ethanol. Intolerance to stresses routinely encountered during industrial fermentations may hinder the commercial development of this organism. A previous C. thermocellum ethanol stress study showed that largest transcriptomic response was in genes and proteins related to nitrogen uptake and metabolism. Results In this study, C. thermocellum was grown to mid-exponential phase and treated with furfural or heat to a final concentration of 3 g.L-1 or 68 C respectively to investigate general and specific physiological and regulatory stress responses. Samples were taken at 10, 30, 60 and 120 min post-shock, and from untreated control fermentations, for transcriptomic analyses and fermentation product determinations and compared to a published dataset from an ethanol stress study. Urea uptake genes were induced following furfural stress, but not to the same extent as ethanol stress and transcription from these genes was largely unaffected by heat stress. The largest transcriptomic response to furfural stress was genes for sulfate transporter subunits and enzymes in the sulfate assimilatory pathway, although these genes were also affected late in the heat and ethanol stress responses. Lactate production was higher in furfural treated culture, although the lactate dehydrogenase gene was not differentially expressed under this condition. Other redox related genes such as a copy of the rex gene, a bifunctional acetaldehyde-CoA/alcohol dehydrogenase and adjacent genes did show lower expression after furfural stress compared to the control, heat and ethanol fermentation profiles. Heat stress induced expression from chaperone related genes and overlap was observed with the responses to the other stresses. This study suggests the

  18. Local residual stress monitoring of aluminum nitride MEMS using UV micro-Raman spectroscopy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Choi, Sukwon; Griffin, Benjamin A.

    2016-01-06

    Localized stress variation in aluminum nitride (AlN) sputtered on patterned metallization has been monitored through the use of UV micro-Raman spectroscopy. This technique utilizing 325 nm laser excitation allows detection of the AlN E2(high) phonon mode in the presence of metal electrodes beneath the AlN layer with a high spatial resolution of less than 400 nm. The AlN film stress shifted 400 MPa from regions where AlN was deposited over a bottom metal electrode versus silicon dioxide. Thus, across wafer stress variations were also investigated showing that wafer level stress metrology, for example using wafer curvature measurements, introduces large uncertaintiesmore » for predicting the impact of AlN residual stress on the device performance.« less

  19. Decipher the Molecular Response of Plant Single Cell Types to Environmental Stresses

    SciTech Connect (OSTI)

    Nourbakhsh-Rey, Mehrnoush; Libault, Marc

    2016-01-01

    The analysis of the molecular response of entire plants or organs to environmental stresses suffers from the cellular complexity of the samples used. Specifically, this cellular complexity masks cell-specific responses to environmental stresses and logically leads to the dilution of the molecular changes occurring in each cell type composing the tissue/organ/plant in response to the stress. Therefore, to generate a more accurate picture of these responses, scientists are focusing on plant single cell type approaches. Several cell types are now considered as models such as the pollen, the trichomes, the cotton fiber, various root cell types including the root hair cell, and the guard cell of stomata. Among them, several have been used to characterize plant response to abiotic and biotic stresses. Lastly, in this review, we are describing the various -omic studies performed on these different plant single cell type models to better understand plant cell response to biotic and abiotic stresses.

  20. Neutron diffraction measurements of residual stresses in friction stir welding: a review

    SciTech Connect (OSTI)

    Woo, Wan Chuck [ORNL; Feng, Zhili [ORNL; Wang, Xun-Li [ORNL; David, Stan A [ORNL

    2011-01-01

    Significant amounts of residual stresses are often generated during welding and result in critical degradation of the structural integrity and performance of components. Neutron diffraction has become a well established technique for the determination of residual stresses in welds because of the unique deep penetration, three-dimensional mapping capability, and volume averaged bulk measurements characteristic of the scattering neutron beam. Friction stir welding has gained prominence in recent years. The authors reviewed a number of neutron diffraction measurements of residual stresses in friction stir welds and highlighted examples addressing how the microstructures and residual stresses are correlated with each other. An example of in situ neutron diffraction measurement result shows the evolution of the residual stresses during welding.

  1. INTERFACE RESIDUAL STRESSES IN DENTAL ZIRCONIA USING LAUE MICRO-DIFFRACTION

    SciTech Connect (OSTI)

    Bale, H. A.; Tamura, N.; Coelho, P.G.; Hanan, J. C.

    2009-01-01

    Due to their aesthetic value and high compressive strength, dentists have recently employed ceramics for restoration materials. Among the ceramic materials, zirconia provides high toughness and crack resistant characteristics. Residual stresses develop in processing due to factors including grain anisotropy and thermal coefficient mismatch. In the present study, polychromatic X-ray (Laue) micro-diffraction provided grain orientation and residual stresses on a clinically relevant zirconia model ceramic disk. A 0.5 mm x 0.024 mm region on zirconia was examined on a 500 nm scale for residual stresses using a focused poly-chromatic synchrotron X-ray beam. Large stresses ranging from - to + 1GPa were observed at some grains. On average, the method suggests a relatively small compressive stress at the surface between 47 and 75 MPa depending on direction.

  2. Assessing Cumulative Thermal Stress in Fish During Chronic Exposure to High Temperature

    SciTech Connect (OSTI)

    Bevelhimer, M.S.; Bennett, W.R.

    1999-11-14

    As environmental laws become increasingly protective, and with possible future changes in global climate, thermal effects on aquatic resources are likely to receive increasing attention. Lethal temperatures for a variety of species have been determined for situations where temperatures rise rapidly resulting in lethal effects. However, less is known about the effects of chronic exposure to high (but not immediately lethal) temperatures and even less about stress accumulation during periods of fluctuating temperatures. In this paper we present a modeling framework for assessing cumulative thermal stress in fish. The model assumes that stress accumulation occurs above a threshold temperature at a rate depending on the degree to which the threshold is exceeded. The model also includes stress recovery (or alleviation) when temperatures drop below the threshold temperature as in systems with large daily variation. In addition to non-specific physiological stress, the model also simulates thermal effects on growth.

  3. Orbital fluid shear stress promotes osteoblast metabolism, proliferation and alkaline phosphates activity in vitro

    SciTech Connect (OSTI)

    Aisha, M.D.; Nor-Ashikin, M.N.K.; Sharaniza, A.B.R.; Nawawi, H.; Froemming, G.R.A.

    2015-09-10

    Prolonged disuse of the musculoskeletal system is associated with reduced mechanical loading and lack of anabolic stimulus. As a form of mechanical signal, the multidirectional orbital fluid shear stress transmits anabolic signal to bone forming cells in promoting cell differentiation, metabolism and proliferation. Signals are channeled through the cytoskeleton framework, directly modifying gene and protein expression. For that reason, we aimed to study the organization of Normal Human Osteoblast (NHOst) cytoskeleton with regards to orbital fluid shear (OFS) stress. Of special interest were the consequences of cytoskeletal reorganization on NHOst metabolism, proliferation, and osteogenic functional markers. Cells stimulated at 250 RPM in a shaking incubator resulted in the rearrangement of actin and tubulin fibers after 72 h. Orbital shear stress increased NHOst mitochondrial metabolism and proliferation, simultaneously preventing apoptosis. The ratio of RANKL/OPG was reduced, suggesting that orbital shear stress has the potential to inhibit osteoclastogenesis and osteoclast activity. Increase in ALP activity and OCN protein production suggests that stimulation retained osteoblast function. Shear stress possibly generated through actin seemed to hold an anabolic response as osteoblast metabolism and functional markers were enhanced. We hypothesize that by applying orbital shear stress with suitable magnitude and duration as a non-drug anabolic treatment can help improve bone regeneration in prolonged disuse cases. - Highlights: • OFS stress transmits anabolic signals to osteoblasts. • Actin and tubulin fibers are rearranged under OFS stress. • OFS stress increases mitochondrial metabolism and proliferation. • Reduced RANKL/OPG ratio in response to OFS inhibits osteoclastogenesis. • OFS stress prevents apoptosis and stimulates ALP and OCN.

  4. Fatigue stress concentration and notch sensitivity in nanocrystalline metals

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Furnish, Timothy A.; Boyce, Brad L.; Sharon, John A.; O’Brien, Christopher J.; Clark, Blythe G.; Arrington, Christian L.; Pillars, Jamin R.

    2016-03-11

    Recent studies have shown the potential for nanocrystalline metals to possess excellent fatigue resistance compared to their coarse-grained counterparts. Although the mechanical properties of nanocrystalline metals are believed to be particularly susceptible to material defects, a systematic study of the effects of geometric discontinuities on their fatigue performance has not yet been performed. In the present work, nanocrystalline Ni–40 wt%Fe containing both intrinsic and extrinsic defects were tested in tension–tension fatigue. The defects were found to dramatically reduce the fatigue resistance, which was attributed to the relatively high notch sensitivity in the nanocrystalline material. Microstructural analysis within the crack-initiation zonesmore » underneath the defects revealed cyclically-induced abnormal grain growth (AGG) as a predominant deformation and crack initiation mechanism during high-cycle fatigue. Furthermore, the onset of AGG and the ensuing fracture is likely accelerated by the stress concentrations, resulting in the reduced fatigue resistance compared to the relatively defect-free counterparts.« less

  5. Step-Stress Accelerated Degradation Testing for Solar Reflectors: Preprint

    SciTech Connect (OSTI)

    Jones, W.; Elmore, R.; Lee, J.; Kennedy, C.

    2011-09-01

    To meet the challenge to reduce the cost of electricity generated with concentrating solar power (CSP) new low-cost reflector materials are being developed including metalized polymer reflectors and must be tested and validated against appropriate failure mechanisms. We explore the application of testing methods and statistical inference techniques for quantifying estimates and improving lifetimes of concentrating solar power (CSP) reflectors associated with failure mechanisms initiated by exposure to the ultraviolet (UV) part of the solar spectrum. In general, a suite of durability and reliability tests are available for testing a variety of failure mechanisms where the results of a set are required to understand overall lifetime of a CSP reflector. We will focus on the use of the Ultra-Accelerated Weathering System (UAWS) as a testing device for assessing various degradation patterns attributable to accelerated UV exposure. Depending on number of samples, test conditions, degradation and failure patterns, test results may be used to derive insight into failure mechanisms, associated physical parameters, lifetimes and uncertainties. In the most complicated case warranting advanced planning and statistical inference, step-stress accelerated degradation (SSADT) methods may be applied.

  6. Cerium migration during PEM fuel cell accelerated stress testing

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Baker, Andrew M.; Mukundan, Rangachary; Borup, Rodney L.; Spernjak, Dusan; Judge, Elizabeth J.; Advani, Suresh G.; Prasad, Ajay K.

    2016-01-01

    Cerium is a radical scavenger which improves polymer electrolyte membrane (PEM) fuel cell durability. During operation, however, cerium rapidly migrates in the PEM and into the catalyst layers (CLs). In this work, membrane electrode assemblies (MEAs) were subjected to accelerated stress tests (ASTs) under different humidity conditions. Cerium migration was characterized in the MEAs after ASTs using X-ray fluorescence. During fully humidified operation, water flux from cell inlet to outlet generated in-plane cerium gradients. Conversely, cerium profiles were flat during low humidity operation, where in-plane water flux was negligible, however, migration from the PEM into the CLs was enhanced. Humiditymore » cycling resulted in both in-plane cerium gradients due to water flux during the hydration component of the cycle, and significant migration into the CLs. Fluoride and cerium emissions into effluent cell waters were measured during ASTs and correlated, which signifies that ionomer degradation products serve as possible counter-ions for cerium emissions. Fluoride emission rates were also correlated to final PEM cerium contents, which indicates that PEM degradation and cerium migration are coupled. Lastly, it is proposed that cerium migrates from the PEM due to humidification conditions and degradation, and is subsequently stabilized in the CLs by carbon catalyst supports.« less

  7. Cerium migration during PEM fuel cell accelerated stress testing

    SciTech Connect (OSTI)

    Baker, Andrew M.; Mukundan, Rangachary; Borup, Rodney L.; Spernjak, Dusan; Judge, Elizabeth J.; Advani, Suresh G.; Prasad, Ajay K.

    2016-01-01

    Cerium is a radical scavenger which improves polymer electrolyte membrane (PEM) fuel cell durability. During operation, however, cerium rapidly migrates in the PEM and into the catalyst layers (CLs). In this work, membrane electrode assemblies (MEAs) were subjected to accelerated stress tests (ASTs) under different humidity conditions. Cerium migration was characterized in the MEAs after ASTs using X-ray fluorescence. During fully humidified operation, water flux from cell inlet to outlet generated in-plane cerium gradients. Conversely, cerium profiles were flat during low humidity operation, where in-plane water flux was negligible, however, migration from the PEM into the CLs was enhanced. Humidity cycling resulted in both in-plane cerium gradients due to water flux during the hydration component of the cycle, and significant migration into the CLs. Fluoride and cerium emissions into effluent cell waters were measured during ASTs and correlated, which signifies that ionomer degradation products serve as possible counter-ions for cerium emissions. Fluoride emission rates were also correlated to final PEM cerium contents, which indicates that PEM degradation and cerium migration are coupled. Lastly, it is proposed that cerium migrates from the PEM due to humidification conditions and degradation, and is subsequently stabilized in the CLs by carbon catalyst supports.

  8. Sulfide stress cracking resistance of low-alloy nickel steels

    SciTech Connect (OSTI)

    Yoshino, Y.; Minozaki, Y.

    1986-04-01

    The sulfide stress cracking (SSC) resistance of Ni-containing low-alloy steels was studied using laboratory and commercial heats over the range of 600 to 800 MPa yield strength (700 to 900 MPa tensile strength). The results were interpreted with regard to observations by metallurgical and electrochemical analyses. In steel containing 1% Cr and 0.5% Mo, the SSC resistance is not affected by up to 2% Ni. A commercial steel with 3.7% Ni-1.8% Cr-0.4% Mo exhibits the same K/sub ISSC/ and Ni-free steels. The cracking resistance begins to deteriorate when fresh martensite exceeds 5 vol%. The lattice diffusion of hydrogen is decreased by the additional Ni, whereas the subsurface hydrogen concentration remains constant in 5% NaCl solution and decreases in NACE TM-01-77 solution up to 5% Ni. Thus, nickel has no harmful effect in terms of hydrogen absorption and diffusion. However, nickel enhances the formation of surface trenches in acidified solutions. This is intensified in the anodically polarized slow extension rate test, which results in loss in elongation. Consequently, nickel per se has no effect on the propagation of SSC unless its addition results in the formation of fresh martensite. However, it may or may not enhance crack initiation, depending on a specific combination of solution and steel, by forming surface trenches that subsequently trigger hydrogen cracking from their bottom.

  9. Stress corrosion cracking of Alloy 600 in high temperature water

    SciTech Connect (OSTI)

    Congleton, J.; Parkins, R.N.; Hemsworth, B.

    1987-01-01

    Slow strain rate stress corrosion tests have been performed on specimens cut from four separate heats of alloy 600 steam generator tubing. Material was tested in the mill annealed and thermally stabilized conditions and after various low temperature aging treatments. Only limited cracking was observed, even for tests at 340/sup 0/C, but the initiation of intergranular cracking was easier on the inner than on the outer surfaces of the tubing. Polarization data has been obtained in high temperature water and in saturated boric acid and saturated lithium hydroxide at the atmospheric boiling points, and slow strain tests were performed at controlled potentials in these environments. Again, only very short cracks formed during the slow strain rate tests which were performed at a strain rate of about 10/sup -6/ s/sup -1/. The data is discussed in terms of the probable crack tip strain rates that would exist in these tests and at other strain rates. It is argued that if cracking occurs, the main role of very low strain rate tests is to provide time for initiation and crack growth, so that cyclic loading or intermittent loading long tests are likely to be more successful in sustaining crack growth in this alloy.

  10. Code System to Calculate Stress-Strains from Transient Pressures.

    Energy Science and Technology Software Center (OSTI)

    2000-04-28

    Version 00 The SPIRT (Stress-strains from Pressures Instigated by Reactor Transients) program was developed to predict the pressure generated by the rapid dispersal of molten UO2 from power-reactor-type fuel rods into the coolant water. This rapid dispersal of molten fuel results from very high-power excursions initiated by the rapid insertion of reactivity. SPIRT was used in the safety analyses of the ATR and ETR. The program can analyze the response of one-dimensional plane, cylindrical, andmore » spherical geometric configurations to pressure-generating heat sources with free-surface or fixed-surface boundary conditions. SPIRT can calculate the response of systems to the dispersal of hot fuel particles as a function of the following variables: enthalpy of fuel at time of dispersal, rate at which fuel is dispersed, size of dispersed fuel droplets, dispersal density of fuel (grams of fuel dispersed per cc of water), quality of water at time of fuel dispersal, enthalpy of water at time of fuel dispersal, system pressure at time of fuel dispersal, and the size and constituency of the medium enveloping the dispersed fuel. By holding all but one of the listed variables constant, and varying that one, the program computes the relative effect of that variable upon the response of systems to the dispersal of hot fuel. SPIRT exists as two releases one, written for UO2 fuel is called SPIRTU; the second, for uranium-aluminide fuel is identified as SPIRTA.« less

  11. Improved Accelerated Stress Tests Based on Fuel Cell Vehicle Data

    SciTech Connect (OSTI)

    Patterson, Timothy; Motupally, Sathya

    2012-06-01

    UTC will led a top-tier team of industry and national laboratory participants to update and improve DOE’s Accelerated Stress Tests (AST’s) for hydrogen fuel cells. This in-depth investigation will focused on critical fuel cell components (e.g. membrane electrode assemblies - MEA) whose durability represented barriers for widespread commercialization of hydrogen fuel cell technology. UTC had access to MEA materials that had accrued significant load time under real-world conditions in PureMotion® 120 power plant used in transit buses. These materials are referred to as end-of-life (EOL) components in the rest of this document. Advanced characterization techniques were used to evaluate degradation mode progress using these critical cell components extracted from both bus power plants and corresponding materials tested using the DOE AST’s. These techniques were applied to samples at beginning-of-life (BOL) to serve as a baseline. These comparisons advised the progress of the various failure modes that these critical components were subjected to, such as membrane degradation, catalyst support corrosion, platinum group metal dissolution, and others. Gaps in the existing ASTs predicted the degradation observed in the field in terms of these modes were outlined. Using the gaps, new AST’s were recommended and tested to better reflect the degradation modes seen in field operation. Also, BOL components were degraded in a test vehicle at UTC designed to accelerate the bus field operation.

  12. Advanced Stress, Strain And Geometrical Analysis In Semiconductor Devices

    SciTech Connect (OSTI)

    Neels, Antonia; Dommann, Alex; Niedermann, Philippe; Farub, Claudiu; Kaenel, Hans von

    2010-11-24

    High stresses and defect densities increases the risk of semiconductor device failure. Reliability studies on potential failure sources have an impact on design and are essential to assure the long term functioning of the device. Related to the dramatically smaller volume of semiconductor devices and new bonding techniques on such devices, new methods in testing and qualification are needed. Reliability studies on potential failure sources have an impact on design and are essential to assure the long term functioning of the device. In this paper, the applications of advanced High Resolution X-ray Diffraction (HRXRD) methods in strain, defect and deformation analysis on semiconductor devices are discussed. HRXRD with Rocking Curves (RC's) and Reciprocal Space Maps (RSM's) is used as accurate, non-destructive experimental method to evaluate the crystalline quality, and more precisely for the given samples, the in-situ strain, defects and geometrical parameters such as tilt and bending of device. The combination with advanced FEM simulations gives the possibility to support efficiently semiconductor devices design.

  13. Shallow Flaws Under Biaxial Loading Conditions, Part II: Application of a Weibull Stress Analysis of the Cruciform Bend Specimen Using a Hydrostatic Stress Criterion

    SciTech Connect (OSTI)

    Bass, B.R.; McAfee, W.J.; Williams, P.T.

    1999-08-01

    Cruciform beam fracture mechanics specimensl have been developed in the Heavy Section Steel Technology (HSST) Program at Oak Ridge National Laboratory (ORNL) to introduce a prototypic, far- field, out-of-plane biaxird bending stress component in the test section that approximates the nonlinear biaxial stresses resulting from pressurized-thernxd-shock or pressure-temperature loading of a nuclear reactor pressure vessel (RPV). Matrices of cruciform beam tests were developed to investigate and quantify the effects of temperature, biaxial loading, and specimen size on fracture initiation toughness of two-dimensional (constant depth), shtdlow, surface flaws. Tests were conducted under biaxial load ratios ranging from uniaxial to equibiaxial. These tests demonstrated that biaxial loading can have a pronounced effect on shallow-flaw fracture toughness in the lower transition temperature region for RPV materials. Two and three- parameter Weibull models have been calibrated using a new scheme (developed at the University of Illinois) that maps toughness data from test specimens with distinctly different levels of crack-tip constraint to a small scale yielding (SSY) Weibull stress space. These models, using the new hydrostatic stress criterion in place of the more commonly used maximum principal stress in the kernel of the OW integral definition, have been shown to correlate the experimentally observed biaxiaI effect in cruciform specimens, thereby providing a scaling mechanism between uniaxial and biaxial loading states.

  14. Characteristic on the thermal stresses near apex in dissimilar materials (Relation between the intensity of stress field and the bonded wedge angle)

    SciTech Connect (OSTI)

    Inoue, T.; Koguchi, H.

    1995-11-01

    The characteristic of thermal stresses near the apex in dissimilar materials under a uniform temperature change is theoretically and numerically investigated. The materials are composed of two isotropic homogeneous wedges with arbitrary angles. The dominant factor of thermal stresses near the apex is represented by Kr{sup p{minus}1}, where p{minus}1 is the order of the stress singularity and K indicates the intensity of the stress field. For the bonded structures of Cu/Si{sub 3}N{sub 4}, the relationship between the wedge angle {var_phi}{sub 1} of material 1 and the total angle {var_phi}{sub 1} + {var_phi}{sub 2} of the bonded wedge, in which K becomes zero, is clarified theoretically. Also, it is shown that the distribution of the intensity K for each root p is divided into two forms. Finally, a relation between the distribution of the thermal stresses near apex and characteristic length of the bonded structure is examined by FEM.

  15. Influence of stress intensity and loading mode on intergranular stress corrosion cracking of Alloy 600 in primary waters of pressurized water reactors

    SciTech Connect (OSTI)

    Rebak, R.B.; Szklarska-Smialowska, Z. . Fontana Corrosion Center)

    1994-05-01

    The steam generator in a pressurized water reactor (PWR) of a nuclear power plant consists mainly of a shell made of carbon (C) steel and tubes made of alloy 600 (UNS N06600). However, alloy 600 suffers environmentally induced cracking with exposure to high-temperature primary water. The susceptibility of alloy 600 to integranular stress corrosion cracking (IGSCC) was investigated as a function of the level of applied stresses and mode of loading. Constant load tests were conducted with specimens prepared from thin wall tubes, and constant deformation tests were conducted using specimens prepared from plates. With tubes exposed to primary water at 330 C, the crack propagation rate (CPR) was found to increase from 1 [times] 10[sup [minus]11] m/s at a stress intensity (K[sub i]) of 10 MPa[radical]m to 1 [times] 10[sup [minus]9] at K[sub i] = 60 MPa[radical]m. CPR obtained using compact specimens prepared from plates were 1 order of magnitude lower than values measured in tubes at the same temperature and in the same solution at each stress intensity. The corollary was that values of crack propagation and threshold stress intensities obtained using compact specimens could not be extrapolated to the behavior of thin wall tubes.

  16. Stress relief to prevent stress corrosion in the transition region of expanded Alloy 600 steam-generator tubing. Final report. [PWR

    SciTech Connect (OSTI)

    Woodward, J.; van Rooyen, D.

    1983-05-01

    The feasibility of preventing primary side roll transition cracking has been investigated, using induction heating to attain stress relief of expanded Ni-Cr-Fe Alloy 600 steam generator tubing. Work on rolled tubing and U-bends has shown that temperatures with which stress relief can be obtained range from 700 to 850/sup 0/C, with lower temperatures in this range requiring longer times at temperature to provide the requisite reduction in residual stresses. No work has yet been done outside this range. Preliminary tests, using induction heating, have been carried out on a mock tube sheet assembly, designed to the dimensions of a typical steam generator, and have identified the type of heating/cooling cycle that would occur in the tube sheet during a stress relief operation. Preliminary results show that the times to reach the higher temperatures in the range observed to give stress relief, of the order of 850/sup 0/C, can be as short as 8 seconds, and less with optimum coil design and power control.

  17. Direct measurement of the alpha-epsilon transition stress and kinetics for shocked iron

    SciTech Connect (OSTI)

    Jensen, Brian J; Gray, Ill, George T; Hixson, Robert S

    2009-01-01

    Iron undergoes a polymorphic phase transformation from alpha phase (bcc) to the epsilon phase (hcp) when compressed to stresses exceeding 13 CPa. Bccause the epsilon phase is denser than the alpha phase, a single shock wave is unstable and breaks up into an elastic wave, a plastic wave, and a phase transition wave. Examination of this structured wave coupled with various phase transformation models has been used to indirectly examine the transition kinetics. Recently, multimillion atom simulations (molecular dynamics) have been used to examine the shock-induced transition in single crystal iron illustrating an orientation dependence of the transition stress, mechanisms, and kinetics. The objective of the current work was to perform plate impact experiments to examine the shock-response of polycrystalline and single crystal iron with nanosecond resolution for impact stresses spanning the {alpha} - {epsilon} transition. The current data reveal an orientation dependence of the transition stress coupled with a transition time that is nonlinearly dependent on the impact stress with a duration ranging from picoseconds to hundreds of nanoseconds. The higher transition stress for iron[100] is in agreement with the predictions from MD calculations that describe an orientation dependence of the transition stress. However, MD calculations do not capture the complexity of the continuum states achieved or the transition kinetics. Further results and implications are discussed in this paper.

  18. Comparison of uniaxial strain and hydrostatic stress pore-volume compressibilities in the Nugget sandstone

    SciTech Connect (OSTI)

    Lachane, D.; Anderson, M.

    1983-10-01

    This paper presents a comparison of rock compressibilities determined under two different stress states. One stress state was the traditional though unrealistic hydrostatic stress method; the other was the more realistic though more complicated uniaxial strain (triaxial stress) with pore pressure method. Compressibilities were determined by both stress methods on Nugget sandstone core plugs from the Rocky Mountain Overthrust Belt. The resulting relationship between the two types of compressibilities did not match with previously published predictions. The uniaxial strain pore volume compressibilities averaged about one-third of the corresponding hydrostatic stress pore volume compressibilities. This was a greater difference than predicted using standard practices. Also, the uniaxial strain data varied only slightly between samples, while the hydrostatic stress data exhibited a greater range of values. From the uniaxial strain measurements, bulk volume compressibility of the Nugget sandstone is constant over the porosity and pressure range of the reservoir. Pore volume compressibility can therefore be easily determined from the porosity and the bulk volume compressibility.

  19. Numerical analysis of residual stress distribution in tubes with spiral weld cladding

    SciTech Connect (OSTI)

    Taljat, B.; Zacharia, T.; Wang, X.L.; Keiser, J.R.; Swindeman, R.W.; Feng, Z.; Jirinec, M.J.

    1998-08-01

    Residual stresses and strains in a tube with spiral weld cladding were analyzed by the finite element (FE) method. The objective of this work was to determine the residual stress-strain state in the weld clad tube and verify the developed FE model, which might serve for future parametric sensitivity studies of various welding parameters on residual stresses in such tubes. An axisymmetric FE model was developed to simulate the circumferential weld cladding process of Alloy 625 on SA210 carbon steel tube and to analyze the residual stress-strain state. The analysis was uncoupled in that the thermal and mechanical analyses were conducted in two separate runs. The results show high tensile residual stresses in the weld cladding and at the interface with a gradual transition to compressive stresses at the inner tube surface. A neutron diffraction technique was used to experimentally determine residual elastic strains in the clad tube. Comparison with the FE results shows good overall agreement. The agreement is excellent in radial and axial elastic strain components, whereas the calculated tangential elastic strain overpredicted the measured value. The difference is discussed, and certain conclusions are given. Finally, some attempts on how to prevent or relieve high tensile stresses in the weld cladding are presented and discussed in this paper.

  20. Residual stress and plastic anisotropy in indented 2024-T351 aluminum disks

    SciTech Connect (OSTI)

    Clausen, Bjorn; Prime, Michael B; Saurabh, Kabra; Brown, Donald W; Pagliaro, Pierluigi; Backlund, Peter; Shaw, Sanjiv; Criss, Everett

    2009-01-01

    Recent studies have proven that generating a well defined residual stress state using the indented disk approach is an excellent way to validate experimental and modeling techniques for measuring and predicting residual stresses. The previous studies dealt with indented stainless steel disks, and included experimental determination of residual stresses using the Contour Method and neutron diffraction measurements. The measured residual stress states showed good agreement between the techniques, and a Finite Element Model predicted residual stress state based upon material properties determined form standard tension and compression/tension tests was also in good agreement with the measurements. In the present work, disks of 2024-T351 Aluminum were investigated. As before, the residual stress profile was measured using neutron diffraction and the Contour Method and Finite Element Modeling was employed to predict the residual stress profile. Analysis and comparison of the three techniques were complicated by the fact that the experimental data shows evidence of plastic anisotropy and strong Bauschinger effect within the indented disks.

  1. Coexistence of colossal stress and texture gradients in sputter deposited nanocrystalline ultra-thin metal films

    SciTech Connect (OSTI)

    Kuru, Yener; Welzel, Udo; Mittemeijer, Eric J.

    2014-12-01

    This paper demonstrates experimentally that ultra-thin, nanocrystalline films can exhibit coexisting colossal stress and texture depth gradients. Their quantitative determination is possible by X-ray diffraction experiments. Whereas a uniform texture by itself is known to generally cause curvature in so-called sin{sup 2}? plots, it is shown that the combined action of texture and stress gradients provides a separate source of curvature in sin{sup 2}? plots (i.e., even in cases where a uniform texture does not induce such curvature). On this basis, the texture and stress depth profiles of a nanocrystalline, ultra-thin (50?nm) tungsten film could be determined.

  2. Sulfide stress-cracking resistance of nitrogen-strengthened stainless steels

    SciTech Connect (OSTI)

    Gaugh, R.R.

    1982-03-01

    A description is given of sulfide stress-cracking tests performed on a number of these alloys. Most were found to be somewhat susceptible to cracking, depending on the stress level. It was determined that this was due to their high manganese content. The mechanism responsible for cracking was not firmly established. One commercial nitrogen-strengthened stainless steel, XM19, was highly resistant to sulfide stress cracking despite a manganese content of 5%. This difference is attributed to the superior corrosion resistance of the alloy. 6 refs.

  3. Residual Stresses in 21-6-9 Stainless Steel Warm Forgings

    SciTech Connect (OSTI)

    Everhart, Wesley A.; Lee, Jordan D.; Broecker, Daniel J.; Bartow, John P.; McQueen, Jamie M.; Switzner, Nathan T.; Neidt, Tod M.; Sisneros, Thomas A.; Brown, Donald W.

    2012-11-14

    Forging residual stresses are detrimental to the production and performance of derived machined parts due to machining distortions, corrosion drivers and fatigue crack drivers. Residual strains in a 21-6-9 stainless steel warm High Energy Rate Forging (HERF) were measured via neutron diffraction. The finite element analysis (FEA) method was used to predict the residual stresses that occur during forging and water quenching. The experimentally measured residual strains were used to calibrate simulations of the three-dimensional residual stress state of the forging. ABAQUS simulation tools predicted residual strains that tend to match with experimental results when varying yield strength is considered.

  4. Damage evolution and residual stresses in plasma-sprayed zirconia thermal barrier coatings.

    SciTech Connect (OSTI)

    Singh, J. P.

    1999-02-03

    Air-plasma-sprayed zirconia thermal barrier coatings were subjected to thermal cycling and residual stress evolution in thermally grown oxide scale was studied by micro- and macro-ruby fluorescence spectroscopy. The macro approach reveals that compressive stress in the oxide scale increases with increasing number of thermal cycles (and thus increasing scale thickness), reaching a value of 1.8 GPa at a scale thickness of 3-4 {micro}m (80 cycles). Micro-ruby fluorescence spectroscopy indicates that protrusions of the zirconia top coat into the bond coat act as localized areas of high stress concentration, leading to damage initiation during thermal cycling.

  5. Fatigue fracture of thin plates under tensile and transverse shear stresses

    SciTech Connect (OSTI)

    Viz, M.J.; Zehnder, A.T.; Bamford, J.D.

    1995-12-31

    Crack growth in thin sheets loaded under tension and transverse shear is studied experimentally and the mechanics of such problems are reviewed. A small scale yielding approach is adopted that describes the crack tip fields using a combination if Kirchhoff plate theory and plane stress elasticity. Techniques for calculating the relevant stress intensity factors are presented and validated with results from six test cases. Fatigue crack growth rates are measured using a double-edge notch test specimen configuration loaded in tension and torsion. A geometrically nonlinear finite element computation is used to determine the stress intensity factors as functions of axial load, torque, and crack length.

  6. Comparative study of stress corrosion cracking of steam generator tube materials in water at 315 C

    SciTech Connect (OSTI)

    De, P.K.; Ghosal, S.K.

    1981-06-01

    Stress corrosion cracking (SCC) of Type 304 and 304L stainless steels, Inconel 600, Incoloy 800, and Monel 400 has been studied in water at 315 C, with or without 0.6 ppm Pb and 0.05 or 8 ppm O/sub 2/. Under mill annealed, cold worked (25%) and stress relieved (675 C, 1 hour) conditions, Type 304L, Incoloy 800, and Monel 400 were resistant to cracking, whereas highly stressed Inconel 600 cracked intergranularly. Inconel 600, heat treated at 600 C for 24 hours or more following annealing, was resistant to SCC. The effects of microstructural changes on SCC behavior are discussed. 20 refs.

  7. Method for measuring residual stresses in materials by plastically deforming the material and interference pattern comparison

    DOE Patents [OSTI]

    Pechersky, Martin J.

    1995-01-01

    A method for measuring residual stress in a material comprising the steps of establishing a speckle pattern on the surface with a first laser then heating a portion of that pattern with an infrared laser until the surface plastically deforms. Comparing the speckle patterns before and after deformation by subtracting one pattern from the other will produce a fringe pattern that serves as a visual and quantitative indication of the degree to which the plasticized surface responded to the stress dung heating and enables calculation of the stress.

  8. 2012 MICROBIAL STRESS RESPONSE GORDON RESEARCH CONFERENCE, JULY 20-25, 2012

    SciTech Connect (OSTI)

    Timothy Donohue

    2012-07-25

    The Gordon Research Conference on MICROBIAL STRESS RESPONSE was held at Mount Holyoke College, South Hadley, Massachusetts, July 15-20, 2012. The Conference was well-attended with 180 participants. The 2012 Microbial Stress Responses Gordon Research Conference will provide a forum for the open reporting of recent discoveries on the diverse mechanisms employed by microbes to respond to stress. Approaches range from analysis at the molecular level (how are signals perceived and transmitted to change gene expression or function) to cellular and microbial community responses. Gordon Research Conferences does not permit publication of meeting proceedings.

  9. Thin Silicon MEMS Contact-Stress Sensor (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    work offers the first, thin, MEMS contact-stress (CS) sensor capable of accurate in situ measruement of time-varying, contact-stress between two solid interfaces (e.g. in vivo cartilage contact-stress and body armor dynamic loading). This CS sensor is a silicon-based device with a load sensitive diaphragm. The diaphragm is doped to create piezoresistors arranged in a full Wheatstone bridge. The sensor is similar in performance to established silicon pressure sensors, but it is reliably produced

  10. Thermal input control and enhancement for laser based residual stress measurements using liquid temperature indicating coatings

    DOE Patents [OSTI]

    Pechersky, Martin J.

    1999-01-01

    An improved method for measuring residual stress in a material comprising the steps of applying a spot of temperature indicating coating to the surface to be studied, establishing a speckle pattern surrounds the spot of coating with a first laser then heating the spot of coating with a far infrared laser until the surface plastically deforms. Comparing the speckle patterns before and after deformation by subtracting one pattern from the other will produce a fringe pattern that serves as a visual and quantitative indication of the degree to which the plasticized surface responded to the stress during heating and enables calculation of the stress.

  11. Thermal input control and enhancement for laser based residual stress measurements using liquid temperature indicating coatings

    DOE Patents [OSTI]

    Pechersky, M.J.

    1999-07-06

    An improved method for measuring residual stress in a material is disclosed comprising the steps of applying a spot of temperature indicating coating to the surface to be studied, establishing a speckle pattern surrounds the spot of coating with a first laser then heating the spot of coating with a far infrared laser until the surface plastically deforms. Comparing the speckle patterns before and after deformation by subtracting one pattern from the other will produce a fringe pattern that serves as a visual and quantitative indication of the degree to which the plasticized surface responded to the stress during heating and enables calculation of the stress. 3 figs.

  12. Chaotic dynamics around astrophysical objects with nonisotropic stresses

    SciTech Connect (OSTI)

    Dubeibe, F. L.; Pachon, Leonardo A.; Sanabria-Gomez, Jose D.

    2007-01-15

    The existence of chaotic behavior for the geodesics of the test particles orbiting compact objects is a subject of much current research. Some years ago, Gueron and Letelier [Phys. Rev. E 66, 046611 (2002)] reported the existence of chaotic behavior for the geodesics of the test particles orbiting compact objects like black holes induced by specific values of the quadrupolar deformation of the source using as models the Erez--Rosen solution and the Kerr black hole deformed by an internal multipole term. In this work, we are interested in the study of the dynamic behavior of geodesics around astrophysical objects with intrinsic quadrupolar deformation or nonisotropic stresses, which induces nonvanishing quadrupolar deformation for the nonrotating limit. For our purpose, we use the Tomimatsu-Sato spacetime [Phys. Rev. Lett. 29 1344 (1972)] and its arbitrary deformed generalization obtained as the particular vacuum case of the five parametric solution of Manko et al. [Phys. Rev. D 62, 044048 (2000)] characterizing the geodesic dynamics throughout the Poincare sections method. We found only regular motion for the geodesics in the Tomimatsu-Sato {delta}=2 solution. Additionally, using the deformed generalization of Tomimatsu-Sato {delta}=2 solution given by Manko et al. we found chaotic motion for oblate deformation instead of prolate deformation, which is in contrast to the results by Gueron and Letelier. It opens the possibility that the particles forming the accretion disk around a large variety of different astrophysical bodies (nonprolate, e.g., neutron stars) could exhibit chaotic dynamics. We also conjecture that the existence of an arbitrary deformation parameter is necessary for the existence of chaotic dynamics.

  13. Ethanol metabolism, oxidative stress, and endoplasmic reticulum stress responses in the lungs of hepatic alcohol dehydrogenase deficient deer mice after chronic ethanol feeding

    SciTech Connect (OSTI)

    Kaphalia, Lata; Boroumand, Nahal; Hyunsu, Ju; Kaphalia, Bhupendra S.; Calhoun, William J.

    2014-06-01

    Consumption and over-consumption of alcoholic beverages are well-recognized contributors to a variety of pulmonary disorders, even in the absence of intoxication. The mechanisms by which alcohol (ethanol) may produce disease include oxidative stress and prolonged endoplasmic reticulum (ER) stress. Many aspects of these processes remain incompletely understood due to a lack of a suitable animal model. Chronic alcohol over-consumption reduces hepatic alcohol dehydrogenase (ADH), the principal canonical metabolic pathway of ethanol oxidation. We therefore modeled this situation using hepatic ADH-deficient deer mice fed 3.5% ethanol daily for 3 months. Blood ethanol concentration was 180 mg% in ethanol fed mice, compared to < 1.0% in the controls. Acetaldehyde (oxidative metabolite of ethanol) was minimally, but significantly increased in ethanol-fed vs. pair-fed control mice. Total fatty acid ethyl esters (FAEEs, nonoxidative metabolites of ethanol) were 47.6 μg/g in the lungs of ethanol-fed mice as compared to 1.5 μg/g in pair-fed controls. Histological and immunohistological evaluation showed perivascular and peribronchiolar lymphocytic infiltration, and significant oxidative injury, in the lungs of ethanol-fed mice compared to pair-fed controls. Several fold increases for cytochrome P450 2E1, caspase 8 and caspase 3 found in the lungs of ethanol-fed mice as compared to pair-fed controls suggest role of oxidative stress in ethanol-induced lung injury. ER stress and unfolded protein response signaling were also significantly increased in the lungs of ethanol-fed mice. Surprisingly, no significant activation of inositol-requiring enzyme-1α and spliced XBP1 was observed indicating a lack of activation of corrective mechanisms to reinstate ER homeostasis. The data suggest that oxidative stress and prolonged ER stress, coupled with formation and accumulation of cytotoxic FAEEs may contribute to the pathogenesis of alcoholic lung disease. - Highlights: • Chronic

  14. Science and Cellular Stresses | U.S. DOE Office of Science (SC...

    Office of Science (SC) Website

    They get stressed from environmental harms like chemicals and radiation, which can damage ... Even low doses of radiation can damage DNA. And while cells have ways to repair that ...

  15. Reduced yield stress for zirconium exposed to iodine: Reactive force field simulation

    SciTech Connect (OSTI)

    Rossi, Matthew L.; Taylor, Christopher D.; van Duin, Adri C. T.

    2014-11-04

    Iodine-induced stress-corrosion cracking (ISCC), a known failure mode for nuclear fuel cladding, occurs when iodine generated during the irradiation of a nuclear fuel pellet escapes the pellet through diffusion or thermal cracking and chemically interacts with the inner surface of the clad material, inducing a subsequent effect on the cladding’s resistance to mechanical stress. To complement experimental investigations of ISCC, a reactive force field (ReaxFF) compatible with the Zr-I chemical and materials systems has been developed and applied to simulate the impact of iodine exposure on the mechanical strength of the material. The study shows that the material’s resistance to stress (as captured by the yield stress of a high-energy grain boundary) is related to the surface coverage of iodine, with the implication that ISCC is the result of adsorption-enhanced decohesion.

  16. Reduced yield stress for zirconium exposed to iodine: Reactive force field simulation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rossi, Matthew L.; Taylor, Christopher D.; van Duin, Adri C. T.

    2014-11-04

    Iodine-induced stress-corrosion cracking (ISCC), a known failure mode for nuclear fuel cladding, occurs when iodine generated during the irradiation of a nuclear fuel pellet escapes the pellet through diffusion or thermal cracking and chemically interacts with the inner surface of the clad material, inducing a subsequent effect on the cladding’s resistance to mechanical stress. To complement experimental investigations of ISCC, a reactive force field (ReaxFF) compatible with the Zr-I chemical and materials systems has been developed and applied to simulate the impact of iodine exposure on the mechanical strength of the material. The study shows that the material’s resistance tomore » stress (as captured by the yield stress of a high-energy grain boundary) is related to the surface coverage of iodine, with the implication that ISCC is the result of adsorption-enhanced decohesion.« less

  17. Mapping residual stress fields from Vickers hardness indents using Raman microprobe spectroscopy

    SciTech Connect (OSTI)

    Sparks, R.G.; Enloe, W.S.; Paesler, M.A.

    1988-12-01

    Micro-Raman spectroscopy is used to map the residual stress fields in the vicinity of Vickers hardness indents. Both 514.5 and 488.0 nm, light is used to excite the effect and the resulting shifted and broadened Raman peaks are analyzed using computer deconvolution. Half-wave plates are used to vary the orientation of the incident later light`s polarization state with respect to crystal orientation. The Raman scattered light is then analyzed for polarization dependences which are indicative of the various components of the Raman scattering tensor. Such studies can yield valuable information about the orientation of stress components in a well known stress field. The results can then be applied to the determination of stress components in machined semiconductor materials.

  18. Amorphous carbon film growth on Si: Correlation between stress and generation of defects into the substrate

    SciTech Connect (OSTI)

    Brusa, R.S.; Macchi, C.; Mariazzi, S.; Karwasz, G.P.; Laidani, N.; Bartali, R.; Anderle, M.

    2005-05-30

    Amorphous carbon films of several thicknesses were prepared by graphite sputtering on crystalline silicon substrate. The samples were depth profiled with positron annihilation spectroscopy for open-volume measurements and characterized for their residual internal stress. It was found that after film growth the substrate presents vacancy-like defects decorated by oxygen in a layer extending in the substrate by several tens of nanometers beyond the film/Si interface. The width of the defected layer and the decoration of vacancy-like defects are directly and inversely proportional to the measured intensity of the residual stress, respectively. These findings indicate the existence of a relaxation mechanism of the stress in the films that involves deeply the substrate. The decorated vacancy-like defects are suggested to be bounded to dislocations induced in the substrate by the stress relaxation.

  19. Primary water stress corrosion crack growth rates in Alloy 600 steam generator tubing

    SciTech Connect (OSTI)

    Lott, R.G.; Jacko, R.J.; Gold, R.E.

    1992-12-31

    Direct measurements of SCC crack growth rates have been used to determine the effects of changes in PWR primary water chemistry on the stress corrosion cracking behavior of Alloy 600 steam generator tubing. Reversing current DC potential measurement techniques have been adapted for use on thin walled tubing containing through-wall circumferential cracks. These techniques have been used to monitor crack rates in Alloy 600 tubing exposed to typical PWR primary water chemistries at 330{degrees}C. Crack growth rate studies, conducted under well defined stress intensity conditions, provide a sensitivity in the assessment of stress corrosion cracking susceptibility that is not possible using more traditional techniques. Preliminary studies have been conducted to determine the effects of B and Li concentrations on the stress corrosion crack growth rate of Alloy 600 tubing.

  20. Corrosion test qualification for in situ stress relief of recirculating steam generators' U-bends

    SciTech Connect (OSTI)

    Monter, J.V.; Miglin, B.P.; Lauer, J.A.

    1989-02-01

    Highly stressed alloy 600 is susceptible to intergranular stress corrosion cracking (IGSCC) in high-purity water at nuclear steam generator (NSG) operating temperatures. Two regions in recirculating steam generators (RSG) are particularly prone to primary-side-initiated SCC: tube expansion transitions of the tube in the tubesheet and tight radii tube bends. One remedial measure to improve IGSCC in these regions is to heat the tubes and thus relieve the residual stresses that contribute significantly to the cracking problem. This article describes a corrosion test program using the accelerated SCC environments of sodium tetrathionate and sodium hydroxide to qualify an in situ stress-relief process for the most SCC-susceptible U-bends in an RSG.

  1. Analysis of stress intensity factors for a new mechanical-corrosion specimen

    SciTech Connect (OSTI)

    Rassineux, B.; Crouzet, D.; Le Hong, S.

    1996-12-01

    Electricite de France is conducting a research program to determine stress corrosion cracking rates (CSC) in the Alloy 600 steam generators tubes of the PWR primary system. The objective is to correlate the cracking rates with the specimen stress intensity factor K{sub I}. One of the samples selected for the purpose of this study is the longitudinal notched specimen (TEL). This paper presents the analysis of the stress intensity factor and its experimental validation. The stress intensity factor has been evaluated for different loads using 3D finite element calculations with the Hellen-Parks and G(q) methods. Only crack propagation are considered. As an assessment of the method, the numerical simulations are in good agreement with the fatigue crack growth rates measured experimentally for TEL and compact tension (CT) specimens.

  2. Failure Stress and Apparent Elastic Modulus of Diesel Particulate Filter Ceramics

    Broader source: Energy.gov [DOE]

    Three established mechanical 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.

  3. Vehicle Technologies Office Merit Review 2014: Residual Stress of Bimetallic Joints and Characterization

    Broader source: Energy.gov [DOE]

    Presentation given by Oak Ridge National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about residual stress...

  4. Rotating Disk-Electrode Aqueous Electrolyte Accelerated Stress Tests for PGM Electrocatalyst/Support Durability Evaluation

    Broader source: Energy.gov [DOE]

    Rotating disk-electrode aqueous electrolyte accelerated stress test protocols developed by the DOE Durability Working Group for platinum group metal (PGM) electrocatalyst/support durability evaluation, October 4, 2011.

  5. A Review & Assessment of Current Operating Conditions Allowable Stresses in ASME Section III Subsection NH

    SciTech Connect (OSTI)

    R. W. Swindeman

    2009-12-14

    The current operating condition allowable stresses provided in ASME Section III, Subsection NH were reviewed for consistency with the criteria used to establish the stress allowables and with the allowable stresses provided in ASME Section II, Part D. It was found that the S{sub o} values in ASME III-NH were consistent with the S values in ASME IID for the five materials of interest. However, it was found that 0.80 S{sub r} was less than S{sub o} for some temperatures for four of the materials. Only values for alloy 800H appeared to be consistent with the criteria on which S{sub o} values are established. With the intent of undertaking a more detailed evaluation of issues related to the allowable stresses in ASME III-NH, the availabilities of databases for the five materials were reviewed and augmented databases were assembled.

  6. Fuel Cell Tech Team Accelerated Stress Test and Polarization Curve Protocols for PEM Fuel Cells

    Broader source: Energy.gov [DOE]

    Accelerated stress test and polarization curve protocols developed by the U.S. DRIVE Fuel Cell Technical Team for polymer electrolyte membrane (PEM) fuel cells, revised January 14, 2013.

  7. Method to control residual stress in a film structure and a system thereof

    DOE Patents [OSTI]

    Parthum, Sr., Michael J.

    2008-12-30

    A method for controlling residual stress in a structure in a MEMS device and a structure thereof includes selecting a total thickness and an overall equivalent stress for the structure. A thickness for each of at least one set of alternating first and second layers is determined to control an internal stress with respect to a neutral axis for each of the at least alternating first and second layers and to form the structure based on the selected total thickness and the selected overall equivalent stress. Each of the at least alternating first and second layers is deposited to the determined thickness for each of the at least alternating first and second layers to form the structure.

  8. Assessment of Initial Test Conditions for Experiments to Assess Irradiation Assisted Stress Corrosion Cracking Mechanisms

    Broader source: Energy.gov [DOE]

    Irradiation-assisted stress corrosion cracking is a key materials degradation issue in today’s nuclear power reactor fleet and affects critical structural components within the reactor core. The...

  9. Contact and Stress Anisotropies in Start-Up Flow of Colloidal...

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

    Contact and Stress Anisotropies in Start-Up Flow of Colloidal Suspensions Authors: Martys, N.S., Lootens, D., George, W., and H Spatiotemporal correlations in start-up flows of...

  10. Borehole Imaging of In Situ Stress Tests at Mirror Lake Research...

    Open Energy Info (EERE)

    at Mirror Lake Research Site Citation U.S. Geological Survey. Borehole Imaging of In Situ Stress Tests at Mirror Lake Research Site Internet. 2013. U.S. Geological Survey. cited...

  11. Method of forming a stress relieved amorphous tetrahedrally-coordinated carbon film

    DOE Patents [OSTI]

    Friedmann, Thomas A.; Sullivan, John P.

    2000-01-01

    A stress-relieved amorphous-diamond film is formed by depositing an amorphous diamond film with specific atomic structure and bonding on to a substrate, and annealing the film at sufficiently high temperature to relieve the compressive stress in said film without significantly softening said film. The maximum annealing temperature is preferably on the order of 650.degree. C., a much lower value than is expected from the annealing behavior of other materials.

  12. Hydrogen-peroxide-induced oxidative stress responses in Desulfovibrio vulgaris Hildenborough

    SciTech Connect (OSTI)

    Zhou, A.; He, Z.; Redding-Johanson, A.M.; Mukhopadhyay, A.; Hemme, C.L.; Joachimiak, M.P.; Bender, K.S.; Keasling, J.D.; Stahl, D.A.; Fields, M.W.; Hazen, T.C.; Arkin, A.P.; Wall, J.D.; Zhou, J.; Luo, F.; Deng, Y.; He, Q.

    2010-07-01

    To understand how sulphate-reducing bacteria respond to oxidative stresses, the responses of Desulfovibrio vulgaris Hildenborough to H{sub 2}O{sub 2}-induced stresses were investigated with transcriptomic, proteomic and genetic approaches. H{sub 2}O{sub 2} and induced chemical species (e.g. polysulfide, ROS) and redox potential shift increased the expressions of the genes involved in detoxification, thioredoxin-dependent reduction system, protein and DNA repair, and decreased those involved in sulfate reduction, lactate oxidation and protein synthesis. A gene coexpression network analysis revealed complicated network interactions among differentially expressed genes, and suggested possible importance of several hypothetical genes in H{sub 2}O{sub 2} stress. Also, most of the genes in PerR and Fur regulons were highly induced, and the abundance of a Fur regulon protein increased. Mutant analysis suggested that PerR and Fur are functionally overlapped in response to stresses induced by H{sub 2}O{sub 2} and reaction products, and the upregulation of thioredoxin-dependent reduction genes was independent of PerR or Fur. It appears that induction of those stress response genes could contribute to the increased resistance of deletion mutants to H{sub 2}O{sub 2}-induced stresses. In addition, a conceptual cellular model of D. vulgaris responses to H{sub 2}O{sub 2} stress was constructed to illustrate that this bacterium may employ a complicated molecular mechanism to defend against the H{sub 2}O{sub 2}-induced stresses.

  13. Assessment of Residual Stresses in 3013 Inner and Outer Containers and Teardrop Samples

    SciTech Connect (OSTI)

    Stroud, Mary Ann; Prime, Michael Bruce; Veirs, Douglas Kirk; Berg, John M.; Clausen, Bjorn; Worl, Laura Ann; DeWald, Adrian T.

    2015-12-08

    This report is an assessment performed by LANL that examines packaging for plutonium-bearing materials and the resilience of its design. This report discusses residual stresses in the 3013 outer, the SRS/Hanford and RFETS/LLNL inner containers, and teardrop samples used in studies to assess the potential for SCC in 3013 containers. Residual tensile stresses in the heat affected zones of the closure welds are of particular concern.

  14. Experimental study of effective stress response of sand under water wave loading

    SciTech Connect (OSTI)

    Clukey, E.C.; Kulhawy, F.H.; Liu, P.L.F.; Turcotte, B.R.

    1984-05-01

    This paper presents experimental wave-sediment interaction data obtained in a 17.1 m long wave tank facility. Pore water pressures as well as total stresses were measured to determine the effective stress response of a medium grained sand subjected to wave heights up to 0.28 m. The results were compared with the theory presented by Yamamoto at the 1978 OTC.

  15. Enhancing Plant Growth and Stress Tolerance through Use of Fungi and

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

    Bacteria that Comprise Plant Microbiomes | Department of Energy Enhancing Plant Growth and Stress Tolerance through Use of Fungi and Bacteria that Comprise Plant Microbiomes Enhancing Plant Growth and Stress Tolerance through Use of Fungi and Bacteria that Comprise Plant Microbiomes This presentation was given by Jim White at the Symbiosis Conference. symbiosis_conference_white.pdf (2.2 MB) More Documents & Publications Symbiosis Conference Speaker and Attendee List Symbiosis

  16. The Effect of Weld Residual Stress on Life of Used Nuclear Fuel Dry Storage Canisters

    SciTech Connect (OSTI)

    Ronald G. Ballinger; Sara E. Ferry; Bradley P. Black; Sebastien P. Teysseyre

    2013-08-01

    With the elimination of Yucca Mountain as the long-term storage facility for spent nuclear fuel in the United States, a number of other storage options are being explored. Currently, used fuel is stored in dry-storage cask systems constructed of steel and concrete. It is likely that used fuel will continue to be stored at existing open-air storage sites for up to 100 years. This raises the possibility that the storage casks will be exposed to a salt-containing environment for the duration of their time in interim storage. Austenitic stainless steels, which are used to construct the canisters, are susceptible to stress corrosion cracking (SCC) in chloride-containing environments if a continuous aqueous film can be maintained on the surface and the material is under stress. Because steel sensitization in the canister welds is typically avoided by avoiding post-weld heat treatments, high residual stresses are present in the welds. While the environment history will play a key role in establishing the chemical conditions for cracking, weld residual stresses will have a strong influence on both crack initiation and propagation. It is often assumed for modeling purposes that weld residual stresses are tensile, high and constant through the weld. However, due to the strong dependence of crack growth rate on stress, this assumption may be overly conservative. In particular, the residual stresses become negative (compressive) at certain points in the weld. The ultimate goal of this research project is to develop a probabilistic model with quantified uncertainties for SCC failure in the dry storage casks. In this paper, the results of a study of the residual stresses, and their postulated effects on SCC behavior, in actual canister welds are presented. Progress on the development of the model is reported.

  17. Stress Testing of the Philips 60W Replacement Lamp L Prize Entry

    SciTech Connect (OSTI)

    Poplawski, Michael E.; Ledbetter, Marc R.; Smith, Mark

    2012-04-24

    The Pacific Northwest National Laboratory, operated by Battelle for the U.S. Department of Energy, worked with Intertek to develop a procedure for stress testing medium screw-base light sources. This procedure, composed of alternating stress cycles and performance evaluation, was used to qualitatively compare and contrast the durability and reliability of the Philips 60W replacement lamp L Prize entry with market-proven compact fluorescent lamps (CFLs) with comparable light output and functionality. The stress cycles applied simultaneous combinations of electrical, thermal, vibration, and humidity stresses of increasing magnitude. Performance evaluations measured relative illuminance, x chromaticity and y chromaticity shifts after each stress cycle. The Philips L Prize entry lamps appear to be appreciably more durable than the incumbent energy-efficient technology, as represented by the evaluated CFLs, and with respect to the applied stresses. Through the course of testing, all 15 CFL samples permanently ceased to function as a result of the applied stresses, while only 1 Philips L Prize entry lamp exhibited a failure, the nature of which was minor, non-destructive, and a consequence of a known (and resolved) subcontractor issue. Given that current CFL technology appears to be moderately mature and no Philips L Prize entry failures could be produced within the stress envelope causing 100 percent failure of the benchmark CFLs, it seems that, in this particular implementation, light-emitting diode (LED) technology would be much more durable in the field than current CFL technology. However, the Philips L Prize entry lamps used for testing were carefully designed and built for the competition, while the benchmark CFLs were mass produced for retail salea distinction that should be taken into consideration. Further reliability testing on final production samples would be necessary to judge the extent to which the results of this analysis apply to production versions of

  18. Thermal-stress analysis of a Fort St. Vrain core-support block under accident conditions

    SciTech Connect (OSTI)

    Carruthers, L.M.; Butler, T.A.; Anderson, C.A.

    1982-01-01

    A thermoelastic stress analysis of a graphite core support block in the Fort St. Vrain High Temperature Gas Cooled Reactor is described. The support block is subjected to thermal stresses caused by a loss of forced circulation accident of the reactor system. Two- and three-dimensional finite element models of the core support block are analyzed using the ADINAT and ADINA codes, and results are given that verify the integrity of this structural component under the given accident condition.

  19. Contact and Stress Anisotropies in Start-Up Flow of Colloidal Suspensions |

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

    Argonne Leadership Computing Facility Contact and Stress Anisotropies in Start-Up Flow of Colloidal Suspensions Authors: Martys, N.S., Lootens, D., George, W., and H Spatiotemporal correlations in start-up flows of attractive colloids are explored by numerical simulations as a function of their volume fraction and shear rate. The suspension is first allowed to flocculate during a time tw, then the stress necessary to induce its flow is computed. We find that, at low volume fractions, the

  20. Residual stress analysis of alloy 600 U-bends, reverse U-bends, and C-rings: Final report

    SciTech Connect (OSTI)

    Rudd, C.O.

    1994-11-01

    Over the last several years, one of the leading causes of alloy 600 steam generator tubing leaks has been the primary-side-initiated, intergranular stress corrosion cracking (IGSCC) in heavily cold-worked regions of the U-bends or tubesheet expansion transitions. Field and laboratory experiences have demonstrated that high residual stresses contribute significantly to the initiation of primary water stress corrosion cracking (PWSCC). EPRI initiated this project to measure and quantify the magnitude of these residual stresses in steam generator tubes as well as in various laboratory tests specimens. the objectives were: To measure the residual stresses in steam generator tube U-bends; To measure residual stresses in reverse U-bend (RUB) specimens as well as residual stresses and X-ray diffraction peak broadening in C-ring specimens used in laboratory tests; and To determine whether residual stress occurs as a result of exposure to steam generator operating temperature. Using an advanced X-ray instrument, investigators measured residual stresses on both the outside diameter (OD) and inside diameter (ID) surfaces and subsurfaces of steam generator U-bends and on the test surfaces of laboratory RUB and C-ring specimens. They measured these residual stresses in the hoop and axial directions and also calculated equivalent stresses. Results are discussed. 25 refs., 92 figs., 6 tabs.

  1. Klimov receives Alexander von Humboldt award

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

    Foundation to promote international cooperation between German institutes of higher learning and those in other countries. Every year, the Foundation enables more than 2,000...

  2. Characterization of Residual Stress as a Function of Friction Stir Welding Parameters in Oxide Dispersion Strengthened (ODS) Steel MA956

    SciTech Connect (OSTI)

    Brewer, Luke N.; Bennett, Martin S.; Baker, B. W.; Payzant, E. Andrew; Kolbus, Lindsay M.

    2015-09-08

    This article characterizes the residual stresses generated by friction stir welding of oxide dispersion strengthened steel MA956 over a series of welding conditions. A plate of MA956 steel was friction stir welded at three conditions: 500 rpm/25 millimeters per minute (mmpm), 400 rpm/50 mmpm and 400 rpm/100 mmpm. The residual stresses across these welds were measured using both x-ray and neutron diffraction techniques. Longitudinal residual stresses up to eighty percent of the yield strength were observed for the 400 rpm/100 mmpm condition. Increasing the traverse rate while holding the rotational speed fixed increased the residual stress levels in the stir zone and at the stir zone-thermomechanically affected zone interface. The stress profiles displayed the characteristic M shape, and the asymmetry between advancing and retreating stress peaks was limited, occurring mainly on the root side of the weld. The large magnitude of the stresses was maintained throughout the thickness of the plates.

  3. Experimental determination of the residual stresses in a Kraft recovery boiler tube

    SciTech Connect (OSTI)

    Wang, Xun-Li; Payzant, E.A.; Taljat, B.

    1997-07-01

    Neutron diffraction was used to determine the residual stresses in a spiral weld overlay tube used in Kraft recovery boilers by the pulp and paper industry. The specimen was a 2.5 inches OD carbon steel tube covered with a layer of Inconel 625 weld overlay. Residual strains in the carbon steel and weld overlay layers were determined using the ferritic (211) and austenitic (311) reflections, respectively. Residual stresses in each material were derived from the measured strains using Hooke`s law and appropriate elastic constants. Tensile stress regions were found not only in the weld metal but also in the heat affected zone in the carbon steel. The maximum tensile stress was located in the weld overlay layer and was found to be 360 MPa, or about 75% of the yield strength of the weld metal. The experimental data were compared with a finite element analysis based on an uncoupled thermal-mechanical formulation. Overall, the modeling results were in satisfactory agreement with the experimental data, although the hoop strain (stress) appears to have been overestimated by the finite element model. Additional neutron diffraction measurements on an annealed tube confirmed that these welding residual stresses were eliminated after annealing at 900{degrees}C for 20 minutes. 18 refs., 7 figs.

  4. Thermal- and electromigration-induced stresses in passivated Al- and AlSiCu-interconnects

    SciTech Connect (OSTI)

    Beckers, D.; Schroeder, H.; Schilling, W.; Eppler, I.

    1997-05-01

    Mechanical stresses in microelectronic devices are of special interest because of degradation effects in microelectronic circuits such as stress induced voiding or electromigration. Al and al-alloys are commonly used as interconnect materials in integrated electronic devices. Stress induced voiding and degradation of metal lines by electromigration are closely related to the stresses in the lines. The authors have studied the strain and stress evolution during thermal cycling, isothermal relaxation and due to electromigration in passivated Al and AlSi(1%)Cu(0.5%) lines by X-Ray diffraction with variation of experimental parameters such as the aspect ratio and the electrical current density. Furthermore the extent of voiding and plastic shear deformation has been determined from the experimental metal strains with the help of finite element calculations. Main results are: (1) During thermal cycling the voiding is less than 2 {center_dot} 10{sup {minus}3}. The extent of plastic shear deformation increases with increasing line width and with decreasing flowstress. (2) During isothermal relaxation void growth occurs but no significant change in the plastic shear deformation. (3) An electric current in the lines causes no measurable additional change of the volume averaged stresses up to line failure.

  5. Therml & Gravitational Stress in Si Wafers; Lim. on Process Htg & Cool. Rates

    Energy Science and Technology Software Center (OSTI)

    1997-01-14

    The MacWafer code determines maximum allowable processing temperatures and maximum heating and cooling rates for thermal processing of silicon semiconductor wafers in single and multiple wafer furnaces. The program runs interactively on Macintosh, PC, and workstation computers. Execution time is typically 20 seconds on a Macintosh 68040 processor operating at 33 MHz. Gravitational stresses and displacements are first calculated based on the user''s input of a support system consisting of a ring beneath the wafermoreand/or arbitrarily placed point supports. The maximum operating temperature is then deduced by comparing the calculated gravitational stresses with the temperature-dependent wafer strength. At lower temperatures, the difference between wafer strength and gravitational stress is used to determine the allowable thermal stress, and hence the allowable radial temperature difference across the wafer. Finally, an analytical model of radial heat transfer in a batch furnace yields the maximum heating or cooling rate as a function of the allowable temperature difference based on the user''s inputs of wafer spacing and furnace power. Outputs to the screen include plots of stress components and vertical displacement, as well as tables of maximum stresses and maximum heating and cooling rates as a function of temperature. All inputs and outputs may be directed to user-named files for further processing or graphical display.less

  6. From coherent to incoherent mismatched interfaces. A generalized continuum formulation of surface stresses

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dingreville, Rémi; Hallil, Abdelmalek; Berbenni, Stéphane

    2014-08-19

    The equilibrium of coherent and incoherent mismatched interfaces is reformulated in the context of continuum mechanics based on the Gibbs dividing surface concept. Two surface stresses are introduced: a coherent surface stress and an incoherent surface stress, as well as a transverse excess strain. Additionally, the coherent surface stress and the transverse excess strain represent the thermodynamic driving forces of stretching the interface while the incoherent surface stress represents the driving force of stretching one crystal while holding the other fixed and thereby altering the structure of the interface. These three quantities fully characterize the elastic behavior of coherent andmore » incoherent interfaces as a function of the in-plane strain, the transverse stress and the mismatch strain. The isotropic case is developed in detail and particular attention is paid to the case of interfacial thermo-elasticity. This exercise provides an insight on the physical significance of the interfacial elastic constants introduced in the formulation and illustrates the obvious coupling between the interface structure and its associated thermodynamics quantities. Finally, an example based on atomistic simulations of Cu/Cu2O interfaces is given to demonstrate the relevance of the generalized interfacial formulation and to emphasize the dependence of the interfacial thermodynamic quantities on the incoherency strain with an actual material system.« less

  7. Therml & Gravitational Stress in Si Wafers; Lim. on Process Htg & Cool. Rates

    Energy Science and Technology Software Center (OSTI)

    1997-01-14

    The MacWafer code determines maximum allowable processing temperatures and maximum heating and cooling rates for thermal processing of silicon semiconductor wafers in single and multiple wafer furnaces. The program runs interactively on Macintosh, PC, and workstation computers. Execution time is typically 20 seconds on a Macintosh 68040 processor operating at 33 MHz. Gravitational stresses and displacements are first calculated based on the user''s input of a support system consisting of a ring beneath the wafermore » and/or arbitrarily placed point supports. The maximum operating temperature is then deduced by comparing the calculated gravitational stresses with the temperature-dependent wafer strength. At lower temperatures, the difference between wafer strength and gravitational stress is used to determine the allowable thermal stress, and hence the allowable radial temperature difference across the wafer. Finally, an analytical model of radial heat transfer in a batch furnace yields the maximum heating or cooling rate as a function of the allowable temperature difference based on the user''s inputs of wafer spacing and furnace power. Outputs to the screen include plots of stress components and vertical displacement, as well as tables of maximum stresses and maximum heating and cooling rates as a function of temperature. All inputs and outputs may be directed to user-named files for further processing or graphical display.« less

  8. Quantification of stress history in type 304L stainless steel using positron annihilation spectroscopy

    SciTech Connect (OSTI)

    Walters, Thomas W.; Walters, Leon C.; Schoen, Marco P.; Naidu, D. Subbaram; Dickerson, Charles; Perrenoud, Ben C.

    2011-04-15

    Five Type 304L stainless steel specimens were subjected to incrementally increasing values of plastic strain. At each value of strain, the associated static stress was recorded and the specimen was subjected to positron annihilation spectroscopy (PAS) using the Doppler Broadening method. A calibration curve for the 'S' parameter as a function of stress was developed based on the five specimens. Seven different specimens (blind specimens labeled B1-B7) of 304L stainless steel were subjected to values of stress inducing plastic deformation. The values of stress ranged from 310 to 517 MPa. The seven specimens were subjected to PAS post-loading using the Doppler Broadening method, and the results were compared against the developed curve from the previous five specimens. It was found that a strong correlation exists between the 'S' parameter, stress, and strain up to a strain value of 15%, corresponding to a stress value of 500 MPa, beyond which saturation of the 'S' parameter occurs. Research Highlights: {yields} Specimens were initially in an annealed/recrystallized condition. {yields} Calibration results indicate positron annihilation measurements yield correlation. {yields} Deformation produced by cold work was likely larger than the maximum strain.

  9. Fracture porosimeter--a new tool for determining fracture conductivity under downhole stress

    SciTech Connect (OSTI)

    Wedorff, C.L.

    1982-09-01

    This paper describes a new, fast, simplified procedure for determining fracture conductivity at downhole stresses. The embedment and crushing of proppant between rock samples from a specific formation are measured at closure stresses. The conductivities of fractures propped with various proppants can be determined rather quickly. As a result, the procedure can supply information useful in determining optimum fracture treatment for a specific well. In the new procedure, samples of formation and proppants are placed in an appropriate confinement chamber. Closure stresses are applied and fracture conductivity can be calculated. A proppant data base obtained using a modified Cooke conductivity test unit includes permeabilities, porosities and fracture widths measured over a range of closure stresses. These properties are dependent upon the type and amount of proppant tested and the stress applied. The paper includes examples of permeability and surface areas of conventional proppants. Fracture conductivity determinations, made with a variety of formations and proppants, indicate how this procedure can be useful when making decisions concerning fracture treatment design. An improvement in equipment design is also presented. The use of a Hoek triaxial cell as a fracture porosimeter allows the application of both closure and confining stresses, thus more closely simulating downhole conditions.

  10. Investigation of the effect of mechanical stress on cold fusion. Master's thesis

    SciTech Connect (OSTI)

    Wohl, B.H.

    1990-03-01

    The purpose of this research was to see if the phenomenon known as cold fusion could be observed after loading a sample of titanium with deuterium gas and then subjecting the sample to mechanical stress. Samples of commercially pure titanium were loaded with deuterium by heating them inductively to 643 + or - 4 C while they were in a deuterium atmosphere. After loading, the samples were subjected to either dynamic tensile stress, a static load, or shear stress. The samples were surrounded by a 4-pi neutron detector during the application of stress and data from the detection system was analyzed for either large bursts of neutrons or continuous low-level emission of neutrons. Despite the fact that the neutron detection system was sensitive to certain environmental factors, application of tensile stress caused no positive indications of cold fusion. One suspiciously large count did occur during the application of shear stress, but that part of the experiment was relatively uncontrolled, and it is believed that the one large count was caused by environmental factors. An upper limit of 1.2 x 10 to the -24th power neutrons/deuteron pair/s has been calculated for the samples involved in the research. This is based on the limits of sensitivity of the neutron detection system.

  11. Comparison of stress-measuring techniques at the DNA-UTP site, Rodgers Hollow, Kentucky

    SciTech Connect (OSTI)

    Finley, R.E.

    1994-12-01

    The Defense Nuclear Agency (DNA) is developing explosives technology through its Underground Technology Program (UTP). Sandia National Laboratories (SNL) has supported the DNA by conducting research to characterize the in situ stress and rock mass deformability at one of the UTP underground sites at Rodgers Hollow, near Louisville, Kentucky on the Fort Knox Military Reservation. The purpose of SNL`s testing was to determine the in situ stress using three different measurement techniques and, if possible, to estimate the rock mass modulus near the underground opening. The three stress-measuring techniques are (1) borehole deformation measurements using overcoring, (2) Anelastic Strain Recovery (ASR) complemented by laboratory ultrasonic and mechanical properties testing, and (3) the in situ flatjack technique using cancellation pressure. Rock mass modulus around the underground opening was estimated using the load deformation history of the flatjack and surrounding rock. Borehole deformation measurements using the overcoring technique probably represent the most reliable method for in situ stress determination in boreholes up to 50 ft (15 m) deep in competent rock around an isolated excavation. The technique is used extensively by the tunneling and mining industries. The ASR technique is also a core-based technique and is used in the petroleum and natural gas industries for characterization of in situ stress from deep boreholes. The flatjack technique has also been used in the tunneling and mining industries, and until recently has been limited to measurement of the stress immediately around the excavation. Results from the flatjack technique must be further analyzed to calculate the in situ stress in the far field.

  12. Gyrokinetic simulation of momentum transport with residual stress from diamagnetic level velocity shears

    SciTech Connect (OSTI)

    Waltz, R. E.; Staebler, G. M.; Solomon, W. M.

    2011-04-15

    Residual stress refers to the remaining toroidal angular momentum (TAM) flux (divided by major radius) when the shear in the equilibrium fluid toroidal velocity (and the velocity itself) vanishes. Previously [Waltz et al., Phys. Plasmas 14, 122507 (2007); errata 16, 079902 (2009)], we demonstrated with GYRO [Candy and Waltz, J. Comp. Phys. 186, 545 (2003)] gyrokinetic simulations that TAM pinching from (ion pressure gradient supported or diamagnetic level) equilibrium ExB velocity shear could provide some of the residual stress needed to support spontaneous toroidal rotation against normal diffusive loss. Here we show that diamagnetic level shear in the intrinsic drift wave velocities (or ''profile shear'' in the ion and electron density and temperature gradients) provides a comparable residual stress. The individual signed contributions of these small (rho-star level) ExB and profile velocity shear rates to the turbulence level and (rho-star squared) ion energy transport stabilization are additive if the rates are of the same sign. However because of the additive stabilization effect, the contributions to the small (rho-star cubed) residual stress is not always simply additive. If the rates differ in sign, the residual stress from one can buck out that from the other (and in some cases reduce the stabilization.) The residual stress from these diamagnetic velocity shear rates is quantified by the ratio of TAM flow to ion energy (power) flow (M/P) in a global GYRO core simulation of a ''null'' toroidal rotation DIII-D [Mahdavi and Luxon, Fusion Sci. Technol. 48, 2 (2005)] discharge by matching M/P profiles within experimental uncertainty. Comparison of global GYRO (ion and electron energy as well as particle) transport flow balance simulations of TAM transport flow in a high-rotation DIII-D L-mode quantifies and isolates the ExB shear and parallel velocity (Coriolis force) pinching components from the larger ''diffusive'' parallel velocity shear driven component and

  13. Sulfur mustard induces an endoplasmic reticulum stress response in the mouse ear vesicant model

    SciTech Connect (OSTI)

    Chang, Yoke-Chen; Wang, James D.; Svoboda, Kathy K.; Casillas, Robert P.; Laskin, Jeffrey D.; Gordon, Marion K.; Gerecke, Donald R.

    2013-04-15

    The endoplasmic reticulum (ER) stress response is a cell survival pathway upregulated when cells are under severe stress. Severely damaged mouse ear skin exposed to the vesicant, sulfur mustard (bis-2-chloroethyl sulfide, SM), resulted in increased expression of ER chaperone proteins that accompany misfolded and incorrectly made proteins targeted for degradation. Time course studies with SM using the mouse ear vesicant model (MEVM) showed progressive histopathologic changes including edema, separation of the epidermis from the dermis, persistent inflammation, upregulation of laminin ?2 (one of the chains of laminin-332, a heterotrimeric skin glycoprotein required for wound repair), and delayed wound healing from 24 h to 168 h post exposure. This was associated with time related increased expression of the cell survival ER stress marker, GRP78/BiP, and the ER stress apoptosis marker, GADD153/CHOP, suggesting simultaneous activation of both cell survival and non-mitochondrial apoptosis pathways. Dual immunofluorescence labeling of a keratinocyte migration promoting protein, laminin ?2 and GRP78/BIP, showed colocalization of the two molecules 72 h post exposure indicating that the laminin ?2 was misfolded after SM exposure and trapped within the ER. Taken together, these data show that ER stress is induced in mouse skin within 24 h of vesicant exposure in a defensive response to promote cell survival; however, it appears that this response is rapidly overwhelmed by the apoptotic pathway as a consequence of severe SM-induced injury. - Highlights: ? We demonstrated ER stress response in the mouse ear vesicant model. ? We described the asymmetrical nature of wound repair in the MEVM. ? We identified the distribution of various ER stress markers in the MEVM.

  14. Corn response to climate stress detected with satellite-based NDVI time series

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wang, Ruoyu; Cherkauer, Keith; Bowling, Laura

    2016-03-23

    Corn growth conditions and yield are closely dependent on climate variability. Leaf growth, measured as the leaf area index, can be used to identify changes in crop growth in response to climate stress. This research was conducted to capture patterns of spatial and temporal corn leaf growth under climate stress for the St. Joseph River watershed, in northeastern Indiana. Leaf growth is represented by the Normalized Difference Vegetative Index (NDVI) retrieved from multiple years (2000–2010) of Landsat 5 TM images. By comparing NDVI values for individual image dates with the derived normal curve, the response of crop growth to environmentalmore » factors is quantified as NDVI residuals. Regression analysis revealed a significant relationship between yield and NDVI residual during the pre-silking period, indicating that NDVI residuals reflect crop stress in the early growing period that impacts yield. Both the mean NDVI residuals and the percentage of image pixels where corn was under stress (risky pixel rate) are significantly correlated with water stress. Dry weather is prone to hamper potential crop growth, with stress affecting most of the observed corn pixels in the area. Oversupply of rainfall at the end of the growing season was not found to have a measurable effect on crop growth, while above normal precipitation earlier in the growing season reduces the risk of yield loss at the watershed scale. Furthermore, the spatial extent of stress is much lower when precipitation is above normal than under dry conditions, masking the impact of small areas of yield loss at the watershed scale.« less

  15. Decipher the Molecular Response of Plant Single Cell Types to Environmental Stresses

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nourbakhsh-Rey, Mehrnoush; Libault, Marc

    2016-01-01

    The analysis of the molecular response of entire plants or organs to environmental stresses suffers from the cellular complexity of the samples used. Specifically, this cellular complexity masks cell-specific responses to environmental stresses and logically leads to the dilution of the molecular changes occurring in each cell type composing the tissue/organ/plant in response to the stress. Therefore, to generate a more accurate picture of these responses, scientists are focusing on plant single cell type approaches. Several cell types are now considered as models such as the pollen, the trichomes, the cotton fiber, various root cell types including the root hairmore » cell, and the guard cell of stomata. Among them, several have been used to characterize plant response to abiotic and biotic stresses. Lastly, in this review, we are describing the various -omic studies performed on these different plant single cell type models to better understand plant cell response to biotic and abiotic stresses.« less

  16. Numerical study of the stress state of a deformation twin in magnesium

    SciTech Connect (OSTI)

    Arul Kumar, M.; Kanjarla, A. K.; Niezgoda, S. R.; Lebensohn, R. A.; Tomé, C. N.

    2014-11-26

    Here, we present a numerical study of the distribution of the local stress state associated with deformation twinning in Mg, both inside the twinned domain and in its immediate neighborhood, due to the accommodation of the twinning transformation shear. A full-field elastoviscoplastic formulation based on fast Fourier transformation is modified to include the shear transformation strain associated with deformation twinning. We performed two types of twinning transformation simulations with: (i) the twin completely embedded inside a single crystal and (ii) the twin front terminating at a grain boundary. We show that: (a) the resulting stress distribution is more strongly determined by the shear transformation than by the intragranular character of the twin or the orientation of the neighboring grain; (b) the resolved shear stress on the twin plane along the twin direction is inhomogeneous along the twin–parent interface; and (c) there are substantial differences in the average values of the shear stress in the twin and in the parent grain that contains the twin. We discuss the effect of these local stresses on twin propagation and growth, and the implications of our findings for the modeling of deformation twinning.

  17. Numerical study of the stress state of a deformation twin in magnesium

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Arul Kumar, M.; Kanjarla, A. K.; Niezgoda, S. R.; Lebensohn, R. A.; Tomé, C. N.

    2014-11-26

    Here, we present a numerical study of the distribution of the local stress state associated with deformation twinning in Mg, both inside the twinned domain and in its immediate neighborhood, due to the accommodation of the twinning transformation shear. A full-field elastoviscoplastic formulation based on fast Fourier transformation is modified to include the shear transformation strain associated with deformation twinning. We performed two types of twinning transformation simulations with: (i) the twin completely embedded inside a single crystal and (ii) the twin front terminating at a grain boundary. We show that: (a) the resulting stress distribution is more strongly determinedmore » by the shear transformation than by the intragranular character of the twin or the orientation of the neighboring grain; (b) the resolved shear stress on the twin plane along the twin direction is inhomogeneous along the twin–parent interface; and (c) there are substantial differences in the average values of the shear stress in the twin and in the parent grain that contains the twin. We discuss the effect of these local stresses on twin propagation and growth, and the implications of our findings for the modeling of deformation twinning.« less

  18. Intrinsic plasma rotation and Reynolds stress at the plasma edge in the HSX stellarator

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wilcox, Robert S.; Talmadge, J. N.; Anderson, David T.; F. S. B. Anderson; Lore, Jeremy D.

    2016-02-05

    Using multi-tipped Langmuir probes in the edge of the HSX stellarator, the radial electric field and parallel flows are found to deviate from the values calculated by the neoclassical transport code PENTA for the optimized quasi-helically symmetric (QHS) configuration. To understand whether Reynolds stress might explain the discrepancy, fluctuating floating potential measurements are made at two locations in the torus corresponding to the low field and high field sides of the device. The measurements at the two locations show clear evidence of a gradient in the Reynolds stress. However, the resulting flow due to the gradient in the stress ismore » found to be large and in opposite directions for the two locations. This makes an estimation of the flux surface average using a small number of measurement locations impractical from an experimental perspective. These results neither confirm nor rule out whether Reynolds stress plays an important role for the QHS configuration. Measurements made in configurations with the quasi-symmetry degraded show even larger flows and greater deviations from the neoclassically calculated velocity profiles than the QHS configuration while the fluctuation magnitudes are reduced. Lastly, for these configurations in particular, the Reynolds stress is most likely not responsible for the additional momentum.« less

  19. Mitofusin-2 protects against cold stress-induced cell injury in HEK293 cells

    SciTech Connect (OSTI)

    Zhang, Wenbin; Chen, Yaomin; Yang, Qun; Che, Honglei; Chen, Xiangjun; Yao, Ting; Zhao, Fang; Liu, Mingchao; Ke, Tao; Chen, Jingyuan; Luo, Wenjing

    2010-06-25

    Mitochondrial impairment is hypothesized to contribute to cell injury during cold stress. Mitochondria fission and fusion are closely related in the function of the mitochondria, but the precise mechanisms whereby these processes regulate cell injury during cold stress remain to be determined. HEK293 cells were cultured in a cold environment (4.0 {+-} 0.1 {sup o}C) for 2, 4, 8, or 12 h. Western blot analyses showed that these cells expressed decreased fission-related protein Drp1 and increased fusion-related protein Mfn2 at 4 h; meanwhile, electron microscopy analysis revealed large and long mitochondrial morphology within these cells, indicating increased mitochondrial fusion. With silencing of Mfn2 but not of Mfn1 by siRNA promoted cold-stress-induced cell death with decreased ATP production in HEK293 cells. Our results show that increased expression of Mfn2 and mitochondrial fusion are important for mitochondrial function as well as cell survival during cold stress. These findings have important implications for understanding the mechanisms of mitochondrial fusion and fission in cold-stress-induced cell injury.

  20. Energetic Consequences of nitrite stress in Desulfovibrio vulgarisHildenborough, inferred from global transcriptional analysis

    SciTech Connect (OSTI)

    He, Qiang; Huang, Katherine H.; He, Zhili; Alm, Eric J.; Fields,Matthew W.; Hazen, Terry C.; Arkin, Adam P.; Wall, Judy D.; Zhou, Jizhong

    2005-11-03

    Many of the proteins that are candidates for bioenergetic pathways involved with sulfate respiration in Desulfovibrio spp. have been studied, but complete pathways and overall cell physiology remain to be resolved for many environmentally relevant conditions. In order to understand the metabolism of these microorganisms under adverse environmental conditions for improved bioremediation efforts, Desulfovibrio vulgaris Hildenborough was used as a model organism to study stress response to nitrite, an important intermediate in the nitrogen cycle. Previous physiological studies demonstrated that growth was inhibited by nitrite and that nitrite reduction was observed to be the primary mechanism of detoxification. Global transcriptional profiling with whole-genome microarrays revealed coordinated cascades of responses to nitrite in pathways of energy metabolism, nitrogen metabolism, oxidative stress response, and iron homeostasis. In agreement with previous observations, nitrite-stressed cells showed a decrease in the expression of genes encoding sulfate reduction functions in addition to respiratory oxidative phosphorylation and ATP synthase activity. Consequently, the stressed cells had decreased expression of the genes encoding ATP-dependent amino acid transporters and proteins involved in translation. Other genes up-regulated in response to nitrite include the genes in the Fur regulon, which is suggested to be involved in iron homeostasis, and genes in the Per regulon, which is predicted to be responsible for oxidative stress response.

  1. Electrodeposition of nickel from low temperature sulfamate electrolytes.Part 1 :Electrochemistry and film stress.

    SciTech Connect (OSTI)

    Hachman, John T.; Kelly, J.J. (IBM Talin, Albert Alec; Goods, Steven Howard

    2005-11-01

    The film stress of Ni films deposited at near-ambient temperatures from sulfamate electrolytes was studied. The particulate filtering of the electrolyte, a routine industrial practice, becomes an important deposition parameter at lower bath temperatures. At 28 C, elevated tensile film stress develops at low current densities (<10 mA/cm{sup 2}) if the electrolyte is filtered. Filtering at higher current densities has a negligible effect on film stress. A similar though less pronounced trend is observed at 32 C. Sulfate-based Ni plating baths display similar film stress sensitivity to filtering, suggesting that this is a general effect for Ni electrodeposition. It is shown that filtering does not significantly change the current efficiency or the pH near the surface during deposition. The observed changes in film stress are thus attributed not to adsorbed hydrogen but instead to the effects of filtering on the formation and concentration of polyborate species due to the decreased solubility of boric acid at near-ambient temperatures.

  2. Apparatus for pre-stress-straining rod-type specimens in tension for in-situ passive fracture testing

    DOE Patents [OSTI]

    Wang, John Jy-an; Liu, Ken C.; Feng, Zhili

    2013-07-31

    A stress-strain testing apparatus imposes a stress-strain on a specimen while disposed in a controlled environment. Each end of the specimen is fastened to an end cap and a strain gage is attached to the specimen. An adjusting mechanism and a compression element are disposed between the end caps forming a frame for applying forces to the end caps and thereby stress-straining the specimen. The adjusting mechanism may be extended or retracted to increase or decrease the imposed stress-strain on the specimen, and the stress-strain is measured by the strain gage on the specimen while the apparatus is exposed to an environment such as high pressure hydrogen. Strain gages may be placed on the frame to measure stress-strains in the frame that may be caused by the environment.

  3. Microstructure and residual stress of magnetron sputtered nanocrystalline palladium and palladium gold films on polymer substrates

    SciTech Connect (OSTI)

    Castrup, Anna; Kuebel, Christian; Scherer, Torsten; Hahn, Horst [KIT-TUD Joint Research Laboratory Nanomaterials, Technische Universitaet Darmstadt (TUD), Petersenstr. 32, 64287 Darmstadt (Germany) and Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021 Karlsruhe (Germany); Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021 Karlsruhe (Germany); KIT-TUD Joint Research Laboratory Nanomaterials, Technische Universitaet Darmstadt (TUD), Petersenstr. 32, 64287 Darmstadt (Germany) and Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), P.O. Box 3640, 76021 Karlsruhe (Germany)

    2011-03-15

    The authors report the structural properties and residual stresses of 500-nm-thick nanocrystalline Pd and PdAu films on compliant substrates prepared by magnetron sputtering as a function of the pressure of the Ar-sputtering gas. Films were analyzed by x-ray diffraction, cross-sectional transmission electron microscopy, and x-ray photoelectron spectroscopy. At low pressures the metal films exhibit strong compressive stresses, which rapidly change to highly tensile with increasing pressure, and then gradually decrease. Along with this effect a change in microstructure is observed from a dense equiaxed structure at low pressures to distinctive columns with reduced atomic density at the column walls at higher pressures. The preparation of nearly stress-free dense nanocrystalline films is demonstrated.

  4. Thermal stress development in a nickel based superalloy during weldability test

    SciTech Connect (OSTI)

    Feng, Z.; Zacharia, T.; David, S.A.

    1997-11-01

    A finite element model has been developed to quantitatively evaluate the local thermomechanical conditions for weld metal solidification cracking in a laboratory weldability test (the Sigmajig test). The loading mechanism in the Sigmajig test was simulated by means of nonlinear spring elements. The effects of weld pool solidification on the thermal and mechanical behaviors of the specimen were considered. An efficient algorithm was developed to include the solidification effects in the material constitutive relations. Stress/temperature/location diagrams were constructed to reveal the local stress development behind the traveling weld pool where solidification cracking occurs. Based on the concept of the material resistance to cracking and the mechanical driving force for cracking, the calculated local stress in the solidification temperature range was used to explain the experimentally observed cracking initiation behaviors of a nickel-based superalloy single crystal under different welding and loading conditions.

  5. Global/local interlaminar stress analysis of a grid-stiffened composite panel

    SciTech Connect (OSTI)

    Wiggenraad, J.F.M.; Bauld, N.R. Jr. Clemson Univ., SC )

    1993-02-01

    A global/local procedure for the computation of the interlaminar stress components at the skin wrap, skin core, and wrap core interfaces for an advanced concept stiffened panel, is described. The procedure consists of a global model of two dimensional shell elements that is used to design a grid stiffened panel with blade type stiffeners, a local model of three dimensional solid elements that is used to compute interlaminar stress components, and a scheme devised to assign displacement boundary conditions for a local model that are based on displacement and rotation data of a few nodes of the global model. A global panel was designed according to strength, stiffness, and stability criteria associated with the design of traditional aircraft wing panels. Interlaminar normal and shearing stress components, computed via the local model, were found to be well below typical tensile normal and shearing strengths of a graphite epoxy material. 8 refs.

  6. Partial Shade Stress Test for Thin-Film Photovoltaic Modules: Preprint

    SciTech Connect (OSTI)

    Silverman, Timothy J.; Deceglie, Michael G.; Deline, Chris; Kurtz, Sarah

    2015-09-02

    Partial shade of monolithic thin-film PV modules can cause reverse-bias conditions leading to permanent damage. In this work, we propose a partial shade stress test for thin-film PV modules that quantifies permanent performance loss. We designed the test with the aid of a computer model that predicts the local voltage, current and temperature stress that result from partial shade. The model predicts the module-scale interactions among the illumination pattern, the electrical properties of the photovoltaic material and the thermal properties of the module package. The test reproduces shading and loading conditions that may occur in the field. It accounts for reversible light-induced performance changes and for additional stress that may be introduced by light-enhanced reverse breakdown. We present simulated and experimental results from the application of the proposed test.

  7. Comparing of Normal Stress Distribution in Static and Dynamic Soil-Structure Interaction Analyses

    SciTech Connect (OSTI)

    Kholdebarin, Alireza; Massumi, Ali; Davoodi, Mohammad; Tabatabaiefar, Hamid Reza

    2008-07-08

    It is important to consider the vertical component of earthquake loading and inertia force in soil-structure interaction analyses. In most circumstances, design engineers are primarily concerned about the analysis of behavior of foundations subjected to earthquake-induced forces transmitted from the bedrock. In this research, a single rigid foundation with designated geometrical parameters located on sandy-clay soil has been modeled in FLAC software with Finite Different Method and subjected to three different vertical components of earthquake records. In these cases, it is important to evaluate effect of footing on underlying soil and to consider normal stress in soil with and without footing. The distribution of normal stress under the footing in static and dynamic states has been studied and compared. This Comparison indicated that, increasing in normal stress under the footing caused by vertical component of ground excitations, has decreased dynamic vertical settlement in comparison with static state.

  8. Stress-corrosion cracking of Inconel alloy 600 in high-temperature water - an update

    SciTech Connect (OSTI)

    Bandy, R.; Van Rooyen, D.

    1984-08-01

    An experimental program on stress corrosion cracking (SCC) aimed at the development of a quantitative model for predicting the behavior of Inconel 600 tubing in high temperature water is described. Empirical data are gathered to relate factors that influence SCC. Work involves U-bends, constant extension rate tests (CERT), and constant load. Plots are made of failure time and crack velocity vs temperature, and also of SCC time vs stress, using a variety of environments related to the ingredients of primary or secondary water. Cold work of Alloy 600 is also included. The effect of temperature is found to yield-semi-log (Arrhenius) curves, and log-log plots of failure time vs stress are presented. Curves of this type are being evaluated for use in extrapolating accelerated test data to operating conditions for predictive purposes. 5 references, 8 figures, 3 tables.

  9. Stress corrosion crack detection in alloy 600 in high temperature caustic. Master`s thesis

    SciTech Connect (OSTI)

    Brisson, B.W.

    1996-06-01

    Alloy 600, the material used for pressurized water reactor steam generator tubing, is susceptible to environmentally assisted stress corrosion cracking. Intergranular stress corrosion cracking (IGSCC) attacks the tubes in areas of high residual stress, and in crevice regions. No method has been successfully developed to monitor steam generator tubing in-situ for crack initiation and growth. Essentially all available published IGSCC crack growth data for alloy 600 is based on non-tubing material. Although it is very likely that the current data base is applicable to tubing processing, differences between tube and other geometries make a comparison between tubing and other data important for verification purposes. However, obtaining crack initiation and growth data from tubing is difficult due to the geometry and the thin wall thickness.

  10. Flaw Stability Considering Residual Stress for Aging Management of Spent Nuclear Fuel Multiple-Purpose Canisters

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Lam, Poh-Sang; Sindelar, Robert L.

    2016-04-28

    A typical multipurpose canister (MPC) is made of austenitic stainless steel and is loaded with spent nuclear fuel assemblies. Because heat treatment for stress relief is not required for the construction of the MPC, the canister is susceptible to stress corrosion cracking in the weld or heat affected zone regions under long-term storage conditions. Logic for flaw acceptance is developed should crack-like flaws be detected by Inservice Inspection. The procedure recommended by API 579-1/ASME FFS-1, Fitness-for-Service, is used to calculate the instability crack length or depth by failure assessment diagram. It is demonstrated that the welding residual stress has amore » strong influence on the results.« less

  11. Fracture porosimeter: a new tool for determining fracture conductivity under downhole stress

    SciTech Connect (OSTI)

    Wendorff, C.L.

    1982-01-01

    This work describes a procedure for determining fracture conductivity at down-hole stresses. The embedment and crushing of proppant between rock samples from a specific formation are measured at closure stresses. The conductivities of fractures propped with various proppants can be determined rather quickly. As a result, the procedure can supply information useful in determining optimum fracture treatment for a specific well. In the procedure, samples of formation and proppants are placed in an appropriate confinement chamber. Closure stresses are applied and fracture conductivity can be calculated. The study includes examples of permeability and surface areas of conventional proppants. Fracture conductivity determinations, made with a variety of formations and proppants, indicate how this procedure can be useful when making decisions concerning fracture treatment design. An improvement in equipment design also is presented. 11 references.

  12. Contributions of stress and oxidation on the formation of whiskers in Pb-free solders

    SciTech Connect (OSTI)

    Duncan, A. J.; Hoffman, E. N.

    2016-01-01

    Understanding the environmental factors influencing formation of tin whiskers on electrodeposited lead free, tin coatings over copper (or copper containing) substrates is the topic of this study . An interim report* summarized initial observations as to the role of stress and oxide formation on whisker growth. From the initial results, two main areas were chosen to be the focus of additional research: the demonstration of effects of elastic stress state in the nucleation of whiskers and the confirmation of the effect of oxygen content in the formation of whiskers. Different levels of elastic stress were induced with the incorporation of a custom designed fixture that loaded the sample in a four-point bending configuration and were maintained in an environmental chamber under conditions deemed favorable for whisker growth. The effects of oxygen content were studied by aging substrates in gas vials of varying absolute pressure and different oxygen partial pressure.

  13. High reflectance-low stress Mo-Si multilayer reflective coatings

    DOE Patents [OSTI]

    Montcalm, Claude; Mirkarimi, Paul B.

    2000-01-01

    A high reflectance-low stress Mo-Si multilayer reflective coating particularly useful for the extreme ultraviolet (EUV) wavelength region. While the multilayer reflective coating has particular application for EUV lithography, it has numerous other applications where high reflectance and low stress multilayer coatings are utilized. Multilayer coatings having high near-normal incidence reflectance (R.gtoreq.65%) and low residual stress (.ltoreq.100 MPa) have been produced using thermal and non-thermal approaches. The thermal approach involves heating the multilayer coating to a given temperature for a given time after deposition in order to induce structural changes in the multilayer coating that will have an overall "relaxation" effect without reducing the reflectance significantly.

  14. Process for fabricating high reflectance-low stress Mo--Si multilayer reflective coatings

    DOE Patents [OSTI]

    Montcalm, Claude; Mirkarimi, Paul B.

    2001-01-01

    A high reflectance-low stress Mo--Si multilayer reflective coating particularly useful for the extreme ultraviolet (EUV) wavelength region. While the multilayer reflective coating has particular application for EUV lithography, it has numerous other applications where high reflectance and low stress multilayer coatings are utilized. Multilayer coatings having high near-normal incidence reflectance (R.gtoreq.65%) and low residual stress (.ltoreq.100 MPa) have been produced using thermal and non-thermal approaches. The thermal approach involves heating the multilayer coating to a given temperature for a given time after deposition in order to induce structural changes in the multilayer coating that will have an overall "relaxation" effect without reducing the reflectance significantly.

  15. Effect of cold work on the growth rates of stress corrosion cracks in structural materials of nuclear systems

    SciTech Connect (OSTI)

    Magdowski, R.; Speidel, M.O.

    1996-10-01

    The growth rates of stress corrosion cracks in austenitic stainless steels and nickel base alloy 600 exposed to simulated boiling water reactor coolant were measured by fracture mechanics testing techniques. Cold work may increase the crack growth rates up to one hundred times. In both, the annealed condition and the cold worked condition, the stress corrosion crack growth rates are independent of stress intensity over a wide K-range and crack growth rates correlate well with yield strength and hardness. In the annealed condition the fracture path is intergranular, but higher degrees of cold work introduce higher proportions of transgranular stress corrosion cracking.

  16. EFFECTS OF SAMPLE SIZE ON THE STRESS-PERMEABILITY RELATIONSHIP FOR NATURAL FRACTURES

    SciTech Connect (OSTI)

    Gale, J. E.; Raven, K. G.

    1980-10-01

    Five granite cores (10.0, 15.0, 19.3, 24.5, and 29.4 cm in diameter) containing natural fractures oriented normal to the core axis, were used to study the effect of sample size on the permeability of natural fractures. Each sample, taken from the same fractured plane, was subjected to three uniaxial compressive loading and unloading cycles with a maximum axial stress of 30 MPa. For each loading and unloading cycle, the flowrate through the fracture plane from a central borehole under constant (±2% of the pressure increment) injection pressures was measured at specified increments of effective normal stress. Both fracture deformation and flowrate exhibited highly nonlinear variation with changes in normal stress. Both fracture deformation and flowrate hysteresis between loading and unloading cycles were observed for all samples, but this hysteresis decreased with successive loading cycles. The results of this study suggest that a sample-size effect exists. Fracture deformation and flowrate data indicate that crushing of the fracture plane asperities occurs in the smaller samples because of a poorer initial distribution of contact points than in the larger samples, which deform more elastically. Steady-state flow tests also suggest a decrease in minimum fracture permeability at maximum normal stress with increasing sample size for four of the five samples. Regression analyses of the flowrate and fracture closure data suggest that deformable natural fractures deviate from the cubic relationship between fracture aperture and flowrate and that this is especially true for low flowrates and small apertures, when the fracture sides are in intimate contact under high normal stress conditions, In order to confirm the trends suggested in this study, it is necessary to quantify the scale and variation of fracture plane roughness and to determine, from additional laboratory studies, the degree of variation in the stress-permeability relationship between samples of the same

  17. Fracture Permeability and in Situ Stress in the Dixie Valley, Nevada, Geothermal Reservoir

    SciTech Connect (OSTI)

    M. D. Zoback

    1999-03-08

    We have collected and analyzed fracture and fluid flow data from wells both within and outside the producing geothermal reservoir at Dixie Valley. Data from wellbore imaging and flow tests in wells outside the producing field that are not sufficiently hydraulically connected to the reservoir to be of commercial value provide both the necessary control group of fracture populations and an opportunity to test the concepts proposed in this study on a regional, whole-reservoir scale. Results of our analysis indicate that fracture zones with high measured permeabilities within the producing segment of the fault are parallel to the local trend of the Stillwater fault and are optimally oriented and critically stressed for frictional failure in the overall east-southeast extensional stress regime measured at the site. In contrast, in the non-producing (i.e., relatively impermeable:) well 66-21 the higher ratio of S{sub hmin} to S{sub v} acts to decrease the shear stress available to drive fault slip. Thus, although many of the fractures at this site (like the Stillwater fault itself) are optimally oriented for normal faulting they are not critically stressed for frictional failure. Although some of the fractures observed in the non-producing well 45-14 are critically stressed for frictional failure, the Stillwater fault zone itself is frictionally stable. Thus, the high horizontal differential stress (i.e., S{sub Hmax}-S{sub hmin}) together with the severe misorientation of the Stillwater fault zone for normal faulting at this location appear to dominate the overall potential for fluid flow.

  18. Stress and Fracture Mechanics Analyses of Boiling Water Reactor and Pressurized Water Reactor Pressure Vessel Nozzles

    SciTech Connect (OSTI)

    Yin, Shengjun; Bass, Bennett Richard; Stevens, Gary; Kirk, Mark

    2011-01-01

    This paper describes stress analysis and fracture mechanics work performed to assess boiling water reactor (BWR) and pressurized water reactor (PWR) nozzles located in the reactor pressure vessel (RPV) adjacent to the core beltline region. Various RPV nozzle geometries were investigated: 1. BWR recirculation outlet nozzle; 2. BWR core spray nozzle3 3. PWR inlet nozzle; ; 4. PWR outlet nozzle; and 5. BWR partial penetration instrument nozzle. The above nozzle designs were selected based on their proximity to the core beltline region, i.e., those nozzle configurations that are located close enough to the core region such that they may receive sufficient fluence prior to end-of-license (EOL) to require evaluation as part of establishing the allowed limits on heatup, cooldown, and hydrotest (leak test) conditions. These nozzles analyzed represent one each of the nozzle types potentially requiring evaluation. The purpose of the analyses performed on these nozzle designs was as follows: To model and understand differences in pressure and thermal stress results using a two-dimensional (2-D) axi-symmetric finite element model (FEM) versus a three-dimensional (3-D) FEM for all nozzle types. In particular, the ovalization (stress concentration) effect of two intersecting cylinders, which is typical of RPV nozzle configurations, was investigated; To verify the accuracy of a selected linear elastic fracture mechanics (LEFM) hand solution for stress intensity factor for a postulated nozzle corner crack for both thermal and pressure loading for all nozzle types; To assess the significance of attached piping loads on the stresses in the nozzle corner region; and To assess the significance of applying pressure on the crack face with respect to the stress intensity factor for a postulated nozzle corner crack.

  19. Systems biology analysis of Zymomonas mobilis ZM4 ethanol stress responses

    SciTech Connect (OSTI)

    Yang, Shihui; Pan, Chongle; Tschaplinski, Timothy J; Hurst, Gregory {Greg} B; Engle, Nancy L; Zhou, Wen; Dam, Phuongan; Xu, Ying; Dice, Lezlee T; Davison, Brian H; Brown, Steven D

    2013-01-01

    Zymomonas mobilis ZM4 is a capable ethanogenic bacterium with high ethanol productivity and high level of ethanol tolerance. Previous studies indicated that several stress-related proteins and changes in the ZM4 membrane lipid composition may contribute to ethanol tolerance. However, the molecular mechanisms of ethanol stress response have not been elucidated fully. In this study, ethanol stress responses were investigated using systems biology tools. Medium supplementation with an initial 47.3 g/L (6% v/v) ethanol reduced Z. mobilis ZM4 glucose consumption, growth rate and ethanol productivity compared to that of untreated controls. Metabolomic profiling showed that ethanol-treated ZM4 cells accumulated greater amounts of glycerol during the entire fermentation process, which may indicate an important role for this metabolite. A proteomic analysis of early exponential growth identified about one thousand proteins, or approximately 56% of the predicted ZM4 proteome. Proteins related to metabolism and stress response such as chaperones and key regulators were more abundant in the early ethanol stress condition. Transcriptomic studies indicated the response of ZM4 to ethanol is dynamic, complex and involves many genes from all the different functional categories. There were fewer genes significantly differentially expressed in the exponential phase compared to that of stationary phase and early stationary phase. Most down-regulated genes were related to translation and ribosome biogenesis, while the ethanol-upregulated genes were mostly related to cellular processes and metabolism. Correlations among the transcriptomics, proteomics and metabolism were examined and among significantly expressed genes or proteins, we observe higher correlation coefficients when fold-change values are higher. This systems biology study elucidates key Z. mobilis ZM4 metabolites, genes and proteins that form the foundation of its distinctive physiology and its multifaceted response to

  20. Measurement of residual stresses in deposited films of SOFC component materials

    SciTech Connect (OSTI)

    Kato, T.; Momma, A.; Nagata, S.; Kasuga, Y.

    1996-12-31

    The stress induced in Solid oxide fuel cells (SOFC)s has important influence on the lifetime of SOFC. But the data on stress in SOFC and mechanical properties of SOW component materials have not been accumulated enough to manufacture SOFC. Especially, the data of La{sub 1-x}Sr{sub x}MnO{sub 3} cathode and La{sub 1-x}Sr{sub x}CrO{sub 3} interconnection have been extremely limited. We have estimated numerically the dependences of residual stress in SOFC on the material properties, the cell structure and the fabrication temperatures of the components, but these unknown factors have caused obstruction to simulate the accurate behavior of residual stress. Therefore, the residual stresses in deposited La{sub 1-x}Sr{sub x}MnO{sub 3} and La{sub 1-x}Sr{sub x}CrO{sub 3} films are researched by the observation of the bending behavior of the substrate strips. The films of SOFC component materials were prepared by the RF sputtering method, because: (1) It can fabricate dense films of poor sinterable material such as La{sub 1-x}Sr{sub x}CrO{sub 3} compared with sintering or plasma spray method. (2) For the complicated material such as perovskite materials, the difference between the composition of a film and that of a target material is generally small. (3) It can fabricate a thick ceramics film by improving of the deposition rate. For example, Al{sub 2}O{sub 3} thick films of 50{mu}m can be fabricated with the deposition rate of approximately 5{mu}m/h industrially. In this paper, the dependence of residual stress on the deposition conditions is defined and mechanical properties of these materials are estimated from the results of the experiments.

  1. A less stressful alternative to oral gavage for pharmacological and toxicological studies in mice

    SciTech Connect (OSTI)

    Walker, Mary K.; Boberg, Jason R.; Walsh, Mary T.; Wolf, Valerie; Trujillo, Alisha; Duke, Melissa Skelton; Palme, Rupert

    2012-04-01

    Oral gavage dosing can induce stress and potentially confound experimental measurements, particularly when blood pressure and heart rate are endpoints of interest. Thus, we developed a pill formulation that mice would voluntarily consume and tested the hypothesis that pill dosing would be significantly less stressful than oral gavage. C57Bl/6 male mice were singly housed and on four consecutive days were exposed to an individual walking into the room (week 1, control), a pill being placed into the cage (week 2), and a dose of water via oral gavage (week 3). Blood pressure and heart rate were recorded by radiotelemetry continuously for 5 h after treatment, and feces collected 610 h after treatment for analysis of corticosterone metabolites. Both pill and gavage dosing significantly increased mean arterial pressure (MAP) during the first hour, compared to control. However, the increase in MAP was significantly greater after gavage and remained elevated up to 5 h, while MAP returned to normal within 2 h after a pill. Neither pill nor gavage dosing significantly increased heart rate during the first hour, compared to control; however, pill dosing significantly reduced heart rate while gavage significantly increased heart rate 25 h post dosing. MAP and heart rate did not differ 24 h after dosing. Lastly, only gavage dosing significantly increased fecal corticosterone metabolites, indicating a systemic stress response via activation of the hypothalamicpituitaryadrenal axis. These data demonstrated that this pill dosing method of mice is significantly less stressful than oral gavage. -- Highlights: ? Developed a novel oral dosing method using a pill that mice will readily consume. ? Assessed stress by blood pressure, heart rate, and fecal corticosterone metabolites. ? Demonstrated that pill dosing is significantly less stressful than oral gavage.

  2. Rac1 and Cdc42 GTPases regulate shear stress-driven ?-catenin signaling in osteoblasts

    SciTech Connect (OSTI)

    Wan, Qiaoqiao; Cho, Eunhye; Yokota, Hiroki; Department of Anatomy and Cell Biology, Indiana University School of Medicine, Indianapolis, IN 46202 ; Na, Sungsoo

    2013-04-19

    Highlights: Shear stress increased TCF/LEF activity and stimulated ?-catenin nuclear localization. Rac1, Cdc42, and RhoA displayed distinct dynamic activity patterns under flow. Rac1 and Cdc42, but not RhoA, regulate shear stress-driven TCF/LEF activation. Cytoskeleton did not significantly affect shear stress-induced TCF/LEF activation. -- Abstract: Beta-catenin-dependent TCF/LEF (T-cell factor/lymphocyte enhancing factor) is known to be mechanosensitive and an important regulator for promoting bone formation. However, the functional connection between TCF/LEF activity and Rho family GTPases is not well understood in osteoblasts. Herein we investigated the molecular mechanisms underlying oscillatory shear stress-induced TCF/LEF activity in MC3T3-E1 osteoblast cells using live cell imaging. We employed fluorescence resonance energy transfer (FRET)-based and green fluorescent protein (GFP)-based biosensors, which allowed us to monitor signal transduction in living cells in real time. Oscillatory (1 Hz) shear stress (10 dynes/cm{sup 2}) increased TCF/LEF activity and stimulated translocation of ?-catenin to the nucleus with the distinct activity patterns of Rac1 and Cdc42. The shear stress-induced TCF/LEF activity was blocked by the inhibition of Rac1 and Cdc42 with their dominant negative mutants or selective drugs, but not by a dominant negative mutant of RhoA. In contrast, constitutively active Rac1 and Cdc42 mutants caused a significant enhancement of TCF/LEF activity. Moreover, activation of Rac1 and Cdc42 increased the basal level of TCF/LEF activity, while their inhibition decreased the basal level. Interestingly, disruption of cytoskeletal structures or inhibition of myosin activity did not significantly affect shear stress-induced TCF/LEF activity. Although Rac1 is reported to be involved in ?-catenin in cancer cells, the involvement of Cdc42 in ?-catenin signaling in osteoblasts has not been identified. Our findings in this study demonstrate that both

  3. Sensitivities of I-V Parameters in C-Si PV Modules of Hygrothermal Stress |

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

    Department of Energy Sensitivities of I-V Parameters in C-Si PV Modules of Hygrothermal Stress Sensitivities of I-V Parameters in C-Si PV Modules of Hygrothermal Stress Presented at the PV Module Reliability Workshop, February 26 - 27 2013, Golden, Colorado pvmrw13_ps4_espec_suzuki.pdf (2.81 MB) More Documents & Publications The Acceleration of Degradation by HAST and Air-HAST in c-Si PV Modules Agenda for the PV Module Reliability Workshop, February 26 - 27 2013, Golden, Colorado

  4. Correlation of laboratory and field stress corrosion results in the power generation industry

    SciTech Connect (OSTI)

    Speidel, M.O.; Magdowski, R.

    1999-11-01

    This paper compares stress corrosion crack growth rates measured in the laboratory with stress corrosion crack growth rates derived from field experience in three different applications of the power generating industry: Pressurized water reactor (PWR) pressure vessel head penetrations with alloy 600, boiling water reactor (BWR) and RBMK (the Russian, watercooled graphite moderated channel-type power reactor, for example Chernobyl) welded nuclear reactor coolant pipes with stabilized stainless steels, and generator rotor retaining rings made from a high strength austenitic steel. It is shown that the minimum time to failure in service can well be predicted from laboratory crack growth rate tests.

  5. 1987 EPRI workshop on mechanisms of primary water intergranular stress corrosion cracking: Proceedings

    SciTech Connect (OSTI)

    Gorman, J.A.; Partridge, M.J.

    1988-09-01

    A meeting on ''Mechanisms of Primary Water IGSCC'' (PWSCC) was organized to give those working in this area an opportunity to share their results, ideas, and plans in regard to investigations of fundamental aspects of the PWSCC phenomenon affecting alloy 600 steam generator tubes. Topics discussed included: (1) General reviews of hydrogen embrittlement and film rupture - anodic dissolution mechanisms of stress corrosion cracking, (2) environmental factors involved in PWSCC, (3) the influence of microstructure on PWSCC, and (4) the influence of stress and plastic strain on PWSCC. A significant portion of the discussions of all of these topics was devoted to the subject of modelling of crack initiation and crack growth.

  6. Stress-corrosion crack initiation process for Alloy 182 weld metal in simulated BWR environments

    SciTech Connect (OSTI)

    Nakayama, Guen; Akashi, Masatsune

    1995-09-01

    For preventing SCC from occurring in the internal structure of materials of the BWR plant, the injection of hydrogen into the core-water so as to reduce the free corrosion potential of the materials were proposed. Because of the lack of basic data of stress-corrosion cracking susceptibility in BWR environment on Ni-based alloys in comparison with stainless steels, the slow strain-rate tensile (SSRT) tests and the creviced bent-beam (CBB) test were conducted for a sensitized Alloy 182 weld metal in high-purity water environments containing dissolved oxygen (DO) and hydrogen (DH) to varied concentrations at 288 C, and the SCC initiation process were examined. The susceptibility of a material to SCC was discussed in terms of the electrode potential effect, and the effects of impurities of the testing water were examined by adding slightly Na{sub 2}, SO{sub 4}. In high purity waters and in the electrode potential region higher than {minus} 0.2 V vs. SHE, the interdendritic stress-corrosion cracks were observed both in the slow strain-rate test and the creviced bent-beam test. SEM observations of sub-cracks at the specimen surfaces revealed that stress-corrosion cracks were initiated when the oxide film had cracked to under-hundred {micro}m wide, that no such individual cracks could grow per se, but that those micro-cracks which happened to be formed in each other`s vicinity would coalesce into large cracks, one of which made propagated as stress-corrosion cracking, and that the stress-corrosion cracking sensitivity became more acute on addition of impurity. In the electrode potential region lower than 0 V, on the other hand, the stress-corrosion cracks were observed to be initiated at bottoms of corrosion pits formed on the specimen surfaces in the former, whereas both type of stress-corrosion cracks were observed between 0 to {minus}0.2V. No stress-corrosion crack was observed even though much the same corrosion pits in the CBB test at {minus}0.4 V.

  7. Use of stress cycling to remove downhole scale from geothermal wells using coiled tubing

    SciTech Connect (OSTI)

    Portman, L.

    1997-12-31

    This paper describes the first application of a relatively new oil field technology to the geothermal industry. The technology is referred to as stress cycling and provides a method of removing hard deposits, such as silica or calcium scales, from tubulars using only jetting action. This new technology lends itself to coiled tubing operations and results in a very fast and efficient clean out operation. The paper describes the theory of stress cycling and lists the operational procedure used on the first job attempted on a geothermal well. The results of the operation are included.

  8. Development of a UF{sub 6} cylinder transient heat transfer/stress analysis model

    SciTech Connect (OSTI)

    Williams, W.R.

    1991-12-31

    A heat transfer/stress analysis model is being developed to simulate the heating to a point of rupture of a cylinder containing UF{sub 6} when it is exposed to a fire. The assumptions underlying the heat transfer portion of the model, which has been the focus of work to date, will be discussed. A key aspect of this model is a lumped parameter approach to modeling heat transfer. Preliminary results and future efforts to develop an integrated thermal/stress model will be outlined.

  9. TEMP-STRESS analysis of a reinforced concrete vessel under internal pressure

    SciTech Connect (OSTI)

    Marchertas, A.H.; Kennedy, J.M.; Pfeiffer, P.A.

    1987-01-01

    Prediction of the response of the Sandia National laboratory 1/6-scale reinforced concrete containment model test was obtained by Argonne National Laboratory (ANL) employing a computer program developed by ANL. The test model was internally pressurized to failure. The two-dimensional code TEMP-STRESS (1-5) has been developed at ANL for stress analysis of plane and axisymmetric 2-D reinforced structures under various thermal conditions. The program is applicable to a wide variety of nonlinear problems, and is utilized in the present study. The comparison of these pretest computations with test data on the containment model should be a good indication of the state of the code.

  10. Thin Silicon MEMS Contact-Stress Sensor (Conference) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    thin, MEMS contact-stress sensor continuously and accurately measures time-varying, solid interface loads over tens of thousands of load cycles. The contact-stress sensor is extremely thin (150 {mu}m) and has a linear output with an accuracy of {+-} 1.5% FSO. Authors: Kotovksy, J ; Tooker, A ; Horsley, D Publication Date: 2010-05-28 OSTI Identifier: 984646 Report Number(s): LLNL-PROC-433955 TRN: US201016%%1413 DOE Contract Number: W-7405-ENG-48 Resource Type: Conference Resource Relation:

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

    SciTech Connect (OSTI)

    Duffy, Stephen

    2013-09-09

    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.

  12. Mechanisms of carbon nanotube-induced toxicity: Focus on oxidative stress

    SciTech Connect (OSTI)

    Shvedova, Anna A.; Pietroiusti, Antonio; Fadeel, Bengt; Kagan, Valerian E.

    2012-06-01

    Nanotechnologies are emerging as highly promising technologies in many sectors in the society. However, the increasing use of engineered nanomaterials also raises concerns about inadvertent exposure to these materials and the potential for adverse effects on human health and the environment. Despite several years of intensive investigations, a common paradigm for the understanding of nanoparticle-induced toxicity remains to be firmly established. Here, the so-called oxidative stress paradigm is scrutinized. Does oxidative stress represent a secondary event resulting inevitably from disruption of biochemical processes and the demise of the cell, or a specific, non-random event that plays a role in the induction of cellular damage e.g. apoptosis? The answer to this question will have important ramifications for the development of strategies for mitigation of adverse effects of nanoparticles. Recent examples of global lipidomics studies of nanoparticle-induced tissue damage are discussed along with proteomics and transcriptomics approaches to achieve a comprehensive understanding of the complex and interrelated molecular changes in cells and tissues exposed to nanoparticles. We also discuss instances of non-oxidative stress-mediated cellular damage resulting from direct physical interference of nanomaterials with cellular structures. -- Highlights: ► CNT induced non-random oxidative stress associated with apoptosis. ► Non-oxidative mechanisms for cellular toxicity of carbon nanotubes. ► Biodegradation of CNT by cells of innate immune system. ► “Omics”-based biomarkers of CNT exposures.

  13. Building the crops of tomorrow: advantages of symbiont-based approaches to improving abiotic stress tolerance

    SciTech Connect (OSTI)

    Tringe, Susannah; Coleman-Derr, Devin

    2014-05-22

    The exponential growth in world population is feeding a steadily increasing global need for arable farmland, a resource that is already in high demand. This trend has led to increased farming on subprime arid and semi-arid lands, where limited availability of water and a host of environmental stresses often severely reduce crop productivity. The conventional approach to mitigating the abiotic stresses associated with arid climes is to breed for stress-tolerant cultivars, a time and labor intensive venture that often neglects the complex ecological context of the soil environment in which the crop is grown. In recent years, studies have attempted to identify microbial symbionts capable of conferring the same stress-tolerance to their plant hosts, and new developments in genomic technologies have greatly facilitated such research. Here, we highlight many of the advantages of these symbiont-based approaches and argue in favor of the broader recognition of crop species as ecological niches for a diverse community of microorganisms that function in concert with their plant hosts and each other to thrive under fluctuating environmental conditions

  14. Crystal Plasticity Analysis of Stress Partitioning Mechanisms and Their Microstructural Dependence in Advanced Steels

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Pu, Chao; Gao, Yanfei

    2015-01-23

    Two-phase advanced steels contain an optimized combination of high yield strength and large elongation strain at failure, as a result of stress partitioning between a hard phase (martensite) and a ductile phase (ferrite or austenite). Provided with strong interfaces between the constituent phases, the failure in the brittle martensite phase will be delayed by the surrounding geometric constraints, while the rule of mixture will dictate a large strength of the composite. To this end, the microstructural design of these composites is imperative especially in terms of the stress partitioning mechanisms among the constituent phases. Based on the characteristic microstructures ofmore » dual phase and multilayered steels, two polycrystalline aggregate models are constructed to simulate the microscopic lattice strain evolution of these materials during uniaxial tensile tests. By comparing the lattice strain evolution from crystal plasticity finite element simulations with advanced in situ diffraction measurements in literature, this study investigates the correlations between the material microstructure and the micromechanical interactions on the intergranular and interphase levels. Finally, it is found that although the applied stress will be ultimately accommodated by the hard phase and hard grain families, the sequence of the stress partitioning on grain and phase levels can be altered by microstructural designs. Implications of these findings on delaying localized failure are also discussed.« less

  15. Evaluation of Missing Pellet Surface Geometry on Cladding Stress Distribution and Magnitude

    SciTech Connect (OSTI)

    Capps, Nathan A.; Montgomery, Robert O.; Sunderland, Dion J.; Spencer, Ben; Pytel, Martin; Wirth, Brian D.

    2014-10-01

    Missing pellet surface (MPS) defects are local geometric defects that periodically occur in nuclear fuel pellets, usually as a result of the mishandling during the manufacturing process. The presences of these defects can lead to clad stress concentrations that are substantial enough to cause a through wall failure for certain conditions of power level, burnup, and power increase. Consequently, the impact of potential MPS defects has limited the rate of power increase or ramp rates in both PWR and BWR systems. Improved 3D MPS models that consider the effect of the MPS geometry can provide better understanding of the margins against PCMI clad failure. The Peregrine fuel performance code has been developed as a part the Consortium of Advanced Simulations of Light Water Reactors (CASL) to consider the inherently multi-physics and multi-dimensional mechanisms that control fuel behavior, including cladding failure by the presence of MPS defects. This paper presents an evaluation of the cladding stress concentrations as a function of MPS defect geometry. The results are the first step in a probabilistic approach to assess cladding failure during power maneuvers. This analysis provides insight into how varying pellet defect geometries affect the distribution of the cladding stress and fuel and cladding temperature and will be used to develop stress concentration factors for 2D and 3D models.

  16. On the Relationship between Stress and Elastic Strain for Porous and Fractured Rock

    SciTech Connect (OSTI)

    Liu, Hui-Hai; Rutqvist, Jonny; Berryman, James G.

    2008-02-25

    Modeling the mechanical deformations of porous and fractured rocks requires a stress-strain relationship. Experience with inherently heterogeneous earth materials suggests that different varieties of Hook's law should be applied within regions of the rock having significantly different stress-strain behavior, e.g., such as solid phase and various void geometries. We apply this idea by dividing a rock body conceptually into two distinct parts. The natural strain (volume change divided by rock volume at the current stress state), rather than the engineering strain (volume change divided by the unstressed rock volume), should be used in Hooke's law for accurate modeling of the elastic deformation of that part of the pore volume subject to a relatively large degree of relative deformation (i.e., cracks or fractures). This approach permits the derivation of constitutive relations between stress and a variety of mechanical and/or hydraulic rock properties. We show that the theoretical predictions of this method are generally consistent with empirical expressions (from field data) and also laboratory rock experimental data.

  17. The effects of machine parameters on residual stress determined using micro-Raman spectroscopy

    SciTech Connect (OSTI)

    Sparks, R.G.; Enloe, W.S.; Paesler, M.A.

    1988-12-01

    The effects of machine parameters on residual stresses in single point diamond turned silicon and germanium have been investigated using micro-Raman spectroscopy. Residual stresses were sampled across ductile feed cuts in < 100 > silicon and germanium which were single point diamond turned using a variety of feed rates, rake angles and clearance angles. High spatial resolution micro-Raman spectra (1{mu}m spot) were obtained in regions of ductile cutting where no visible surface damage was present. The use of both 514-5nm and 488.0nm excitation wavelengths, by virtue of their differing characteristic penetration depths in the materials, allowed determinations of stress profiles as a function of depth into the sample. Previous discussions have demonstrated that such Raman spectra will exhibit asymmetrically broadened peaks which are characteristic of the superposition of a continuum of Raman scatterers from the various depths probed. Depth profiles of residual stress were obtained using computer deconvolution of the resulting asymmetrically broadened raman spectra.

  18. Tularosa Basin Play Fairway Analysis: Partial Basin and Range Heat and Zones of Critical Stress Maps

    SciTech Connect (OSTI)

    Adam Brandt

    2015-11-15

    Interpolated maps of heat flow, temperature gradient, and quartz geothermometers are included as TIF files. Zones of critical stress map is also included as a TIF file. The zones are given a 5km diameter buffer. The study area is only a part of the Basin and Range, but it does includes the Tularosa Basin.

  19. A new coal-permeability model: Internal swelling stress and fracture-matrix interaction

    SciTech Connect (OSTI)

    Liu, H.H.; Rutqvist, J.

    2009-10-01

    We have developed a new coal-permeability model for uniaxial strain and constant confining stress conditions. The model is unique in that it explicitly considers fracture-matrix interaction during coal deformation processes and is based on a newly proposed internal-swelling stress concept. This concept is used to account for the impact of matrix swelling (or shrinkage) on fracture-aperture changes resulting from partial separation of matrix blocks by fractures that do not completely cut through the whole matrix. The proposed permeability model is evaluated with data from three Valencia Canyon coalbed wells in the San Juan Basin, where increased permeability has been observed during CH{sub 4} gas production, as well as with published data from laboratory tests. Model results are generally in good agreement with observed permeability changes. The importance of fracture-matrix interaction in determining coal permeability, demonstrated in this work using relatively simple stress conditions, underscores the need for a dual-continuum (fracture and matrix) mechanical approach to rigorously capture coal-deformation processes under complex stress conditions, as well as the coupled flow and transport processes in coal seams.

  20. /sup 14/C-incorporation into sugars and organic acids of water-stressed maize leaves

    SciTech Connect (OSTI)

    Becker, T.; Fock, H.

    1986-04-01

    The incorporation of /sup 14/C into sugars and some organic acids of maize leaves has been studied in relation to the leaf water potential by feeding /sup 14/CO/sub 2/ (370 ppm) for 1,2 and 4 min during steady state photosynthesis at 25/sup 0/C (PAR = 800 ..mu..mol m/sup -2/s/sup -1/). The relative specific radioactivity (RSA) of the sugars was low (0.2% after 4 min) at -0.62 MPa (control) and decreased by about 50% when psi dropped to -0.95 MPa. The authors conclude that the low rate of photosynthetic sugar synthesis in maize leaves decreased during water stress. The RSA of malate was extremely low at -0.62 MPa (0.02%). This result may be the consequence of the large pool size of malate in maize leaves. The authors presume that there are two malate pools present in maize leaves, a small metabolic pool and a larger storage pool. The RSA of malate decreased during the stress period. This is consistent with the decline in net CO/sub 2/ uptake during water stress. The pool sizes of citrate and isocitrate increased when psi dropped to -0.95 MPa. As practically no radioactivity was detected in these organic acids, they conclude that these compounds are synthesized from unlabelled precursors during water stress.

  1. Stress induced anisotropy in CoFeMn soft magnetic nanocomposites

    SciTech Connect (OSTI)

    Leary, A. M. Keylin, V.; McHenry, M. E.; Ohodnicki, P. R.

    2015-05-07

    The use of processing techniques to create magnetic anisotropy in soft magnetic materials is a well-known method to control permeability and losses. In nanocomposite materials, field annealing below the Curie temperature results in uniaxial anisotropy energies up to ?2?kJ/m{sup 3}. Higher anisotropies up to ?10?kJ/m{sup 3} result after annealing Fe-Si compositions under stress due to residual stress in the amorphous matrix acting on body centered cubic crystals. This work describes near zero magnetostriction Co{sub 80?x?y}Fe{sub x}Mn{sub y}Nb{sub 4}B{sub 14}Si{sub 2} soft magnetic nanocomposites, where x and y?stress induced anisotropies up to ?50?kJ/m{sup 3} and improved mechanical properties with respect to Fe-Si compositions. Difference patterns measured using transmission X-ray diffraction show evidence of affine strain with respect to the stress axis.

  2. A study of the mechanism of primary water stress corrosion cracking of Alloy 600

    SciTech Connect (OSTI)

    Gourgues, A.F.; Andrieu, E.; Scott, P.M.

    1995-12-31

    Two aspects of the mechanism of stress corrosion cracking of Alloy 600 in pressurized water reactors (PWR) primary water have been studied in detail. Results are presented showing that grain boundaries of Alloy 600 are embrittled to a depth of several microns by exposure to primary water in an unstressed condition. It has been established that this embrittlement is not reversible by high temperature degassing and cannot be directly due to hydrogen. The results seem to support the hypothesis that oxygen atom penetration of grain boundaries is possible. However, no evidence of formation of grain boundary gas bubbles or oxides has been found. It is envisaged that this embrittlement process could sequentially act at the tip of a growing stress corrosion crack. The second phenomenon under study has been the plastic deformation behavior of Alloy 600 since it is known that cold work and stress have an important effect on stress corrosion cracking sensitivity. Results of plastic deformation during cyclic straining at various controlled strain rates are presented showing that Alloy 600 is not very sensitive to loading history and that cold work is of an essentially kinematic nature.

  3. Effect of lithium hydroxide on primary water stress corrosion cracking of Alloy 600 tubing

    SciTech Connect (OSTI)

    Jacko, R. )

    1991-09-01

    Primary water stress corrosion cracking (PWSCC) studies were performed on Alloy 600 in simulated PWR high lithium primary water. Tests were conducted at 330{degree}C with Li concentrations ranging from 0.7 to 3.5 ppM in solutions containing boric acid and dissolved hydrogen. Highly stressed, Alloy 600 reverse U-bend specimens (RUBs) were predominantly used for tests. Both mill-annealed (MA) and thermally treated (TT) Alloy 600 were tested. The large number of specimens tested allowed the use of rigorous statistical techniques to interpret the variability of PWSCC performance. Results of tests of MA 600 RUBs at 2 stress levels show no effect of chemistry on the time to initiate PWSCC cracks over the range from 0.7 to 3.5 ppM Li. However, results for TT 600 RUBs and in MA 600 RUBs at a third stress level show the tendency for a shorter time to initiate PWSCC cracks at a Li concentration of 3.5 ppM. Analysis suggests that certain Alloy 600 components may experience an increase in PWSCC by using the higher LI content primary water due to a subtle influence of chemistry on PWSCC. 5 refs. 8 figs., 3 tabs.

  4. Stress corrosion cracking of Ni-Cu alloy 400 tubes in feedwater heaters

    SciTech Connect (OSTI)

    Amar, A.S.

    1994-12-31

    This paper presents the results of the inspections and metallurgical evaluations of a high pressure feedwater heater that experienced numerous tube failures after a short service life. Using EPRI NDE Center technical support, tubes were eddy current tested with special probes in the tubesheet region and with conventional probes in the remaining straight portion. Pulled tubes were metallurgically examined. Crack depths were correlated with eddy current indications. Short axial cracks were found on the inner surface of the tubes at roll transitions. Failures were attributed to intergranular stress corrosion cracking. The cold drawn-stress relieved Monel{trademark} (Alloy 400) tube had < 10 KSI hoop residual stress, however the residual stress was probably much higher in the roll transition. A large number of tubes were plugged based on the eddy current indications, however several tubes that showed no indications had leaked a few months later. This suggested that after initiation, crack growth was rapid. The heater was replaced after 4.5 years of service.

  5. Report 20.3: Stress Testing of LED PAR38 Lamps

    Broader source: Energy.gov [DOE]

    A small sample of each of the Application Summary Report 20 PAR38 lamp types underwent stress testing that included substantial temperature and humidity changes, electrical variation, and vibration. The results do not directly address expected lifetime, but can be compared with one another, as well as with benchmark conventional products, to assess the relative robustness of the product designs. (24 pages, December 2014)

  6. Measurement and interpretation of threshold stress intensity factors for steels in high-pressure hydrogen gas.

    SciTech Connect (OSTI)

    Nibur, Kevin A.

    2010-11-01

    Threshold stress intensity factors were measured in high-pressure hydrogen gas for a variety of low alloy ferritic steels using both constant crack opening displacement and rising crack opening displacement procedures. The sustained load cracking procedures are generally consistent with those in ASME Article KD-10 of Section VIII Division 3 of the Boiler and Pressure Vessel Code, which was recently published to guide design of high-pressure hydrogen vessels. Three definitions of threshold were established for the two test methods: K{sub THi}* is the maximum applied stress intensity factor for which no crack extension was observed under constant displacement; K{sub THa} is the stress intensity factor at the arrest position for a crack that extended under constant displacement; and K{sub JH} is the stress intensity factor at the onset of crack extension under rising displacement. The apparent crack initiation threshold under constant displacement, K{sub THi}*, and the crack arrest threshold, K{sub THa}, were both found to be non-conservative due to the hydrogen exposure and crack-tip deformation histories associated with typical procedures for sustained-load cracking tests under constant displacement. In contrast, K{sub JH}, which is measured under concurrent rising displacement and hydrogen gas exposure, provides a more conservative hydrogen-assisted fracture threshold that is relevant to structural components in which sub-critical crack extension is driven by internal hydrogen gas pressure.

  7. Strain rate, temperature and representative length scale influence on plasticity and yield stress in copper

    SciTech Connect (OSTI)

    Dupont, Virginie; Germann, Timothy C

    2011-01-18

    Shock compression of materials constitutes a complex process involving high strain rates, elevated temperatures and compression of the lattice. Materials properties are greatly affected by temperature, the representative length scale and the strain rate of the deformation. Experimentally, it is difficult to study the dynamic microscopic mechanisms that affect materials properties following high intensity shock loading, but they can be investigated using molecular dynamics (MD) simulations. Moreover, MD allows a better control over some parameters. We are using MD simulations to study the effect of the strain rate, representative length scale and temperature on the properties of metals during compression. A half-million-atom Cu sample is subjected to strain rates ranging from 10{sup 7} s{sup -1} to 10{sup 12} s{sup -1} at different temperatures ranging from 50K to 1500K. Single crystals as well as polycrystals are investigated. Plasticity mechanisms as well as the evolution of the micro- and macro-yield stress are observed. Our results show that the yield stress increases with increasing strain rate and decreasing temperature. We also show that the strain rate at which the transition between constant and increasing yield stress as a function of the temperature occurs increases with increasing temperature. Calculations at different grain sizes will give an insight into the grain size effect on the plasticity mechanisms and the yield stress.

  8. Measurement and interpretation of threshold stress intensity factors for steels in high-pressure hydrogen gas.

    SciTech Connect (OSTI)

    Dadfarnia, Mohsen; Nibur, Kevin A.; San Marchi, Christopher W.; Sofronis, Petros; Somerday, Brian P.; Foulk, James W., III; Hayden, Gary A.

    2010-07-01

    Threshold stress intensity factors were measured in high-pressure hydrogen gas for a variety of low alloy ferritic steels using both constant crack opening displacement and rising crack opening displacement procedures. The sustained load cracking procedures are generally consistent with those in ASME Article KD-10 of Section VIII Division 3 of the Boiler and Pressure Vessel Code, which was recently published to guide design of high-pressure hydrogen vessels. Three definitions of threshold were established for the two test methods: K{sub THi}* is the maximum applied stress intensity factor for which no crack extension was observed under constant displacement; K{sub THa} is the stress intensity factor at the arrest position for a crack that extended under constant displacement; and K{sub JH} is the stress intensity factor at the onset of crack extension under rising displacement. The apparent crack initiation threshold under constant displacement, K{sub THi}*, and the crack arrest threshold, K{sub THa}, were both found to be non-conservative due to the hydrogen exposure and crack-tip deformation histories associated with typical procedures for sustained-load cracking tests under constant displacement. In contrast, K{sub JH}, which is measured under concurrent rising displacement and hydrogen gas exposure, provides a more conservative hydrogen-assisted fracture threshold that is relevant to structural components in which sub-critical crack extension is driven by internal hydrogen gas pressure.

  9. Overlapping double etch technique for evaluation of metallic alloys to stress corrosion cracking

    DOE Patents [OSTI]

    Not Available

    1980-05-28

    A double overlapping etch zone technique for evaluation of the resistance of metallic alloys to stress corrosion cracking is described. The technique involves evaluating the metallic alloy along the line of demarcation between an overlapping double etch zone and single etch zone formed on the metallic alloy surface.

  10. Overlapping double etch technique for evaluation of metallic alloys to stress corrosion cracking

    DOE Patents [OSTI]

    Steeves, Arthur F.; Stewart, James C.

    1981-01-01

    A double overlapping etch zone technique for evaluation of the resistance of metallic alloys to stress corrosion cracking. The technique involves evaluating the metallic alloy along the line of demarcation between an overlapping double etch zone and single etch zone formed on the metallic alloy surface.

  11. Development of a MEMS dual-axis differential capacitance floating element shear stress sensor

    SciTech Connect (OSTI)

    Barnard, Casey; Griffin, Benjamin

    2015-09-01

    A single-axis MEMS wall shear stress sensor with differential capacitive transduction method is produced. Using a synchronous modulation and demodulation interface circuit, the system is capable of making real time measurements of both mean and fluctuating wall shear stress. A sensitivity of 3.44 mV/Pa is achieved, with linearity in response demonstrated up to testing limit of 2 Pa. Minimum detectable signals of 340 μPa at 100 Hz and 120 μPa at 1 kHz are indicated, with a resonance of 3.5 kHz. Multiple full scale wind tunnel tests are performed, producing spectral measurements of turbulent boundary layers in wind speeds ranging up to 0.5 Ma (18 Pa of mean wall shear stress). The compact packaging allows for minimally invasive installation, and has proven relatively robust over multiple testing events. Temperature sensitivity, likely due to poor CTE matching of packaged materials, is an ongoing concern being addressed. These successes are being directly leveraged into a development plan for a dual-axis wall shear stress sensor, capable of producing true vector estimates at the wall.

  12. Oscillatory motion based measurement method and sensor for measuring wall shear stress due to fluid flow

    DOE Patents [OSTI]

    Armstrong, William D.; Naughton, Jonathan; Lindberg, William R.

    2008-09-02

    A shear stress sensor for measuring fluid wall shear stress on a test surface is provided. The wall shear stress sensor is comprised of an active sensing surface and a sensor body. An elastic mechanism mounted between the active sensing surface and the sensor body allows movement between the active sensing surface and the sensor body. A driving mechanism forces the shear stress sensor to oscillate. A measuring mechanism measures displacement of the active sensing surface relative to the sensor body. The sensor may be operated under periodic excitation where changes in the nature of the fluid properties or the fluid flow over the sensor measurably changes the amplitude or phase of the motion of the active sensing surface, or changes the force and power required from a control system in order to maintain constant motion. The device may be operated under non-periodic excitation where changes in the nature of the fluid properties or the fluid flow over the sensor change the transient motion of the active sensor surface or change the force and power required from a control system to maintain a specified transient motion of the active sensor surface.

  13. Residual Stress In Sheet Metal Parts Made By Incremental Forming Process

    SciTech Connect (OSTI)

    Tanaka, Shigekazu; Nakamura, Tamotsu; Hayakawa, Kunio; Nakamura, Hideo; Motomura, Kazuo

    2007-05-17

    Incremental sheet metal forming, which uses a CNC forming stylus, is new flexible forming process not requiring the use of any expensive dies. We have applied the incremental forming process to dental prosthesis. This new process, however, posed difficult problems. After removing the outer portion of the incremental formed sheet metal part, the inner part is distorted. In this paper, the residual stress in the sheet metal part obtained by incremental forward stretch forming operations has been examined. Numerical simulations were conducted for solid elements. When small rigid ball slides on the metal sheet with a certain vertical feed, tension residual stress is produced in the upper layer of the sheet and compression stress in the lower. Then, the resultant moments throughout the sheet cause negative spring-back when the outer portion is removed. A systematic study of the behavior was conducted in this paper. Parameters considered included the tool radius and the vertical tool feed rate. The tip radius of forming stylus has a significant influence on the residual stress. The smaller radius of forming stylus, the larger bending force becomes. And new process with double forming styluses is examined to reduce the bending force.

  14. Intergranular attack and stress corrosion cracking of Alloy 600 in high-temperature caustic solutions containing contaminants

    SciTech Connect (OSTI)

    Bandy, R.; Roberge, R.; van Rooyen, D.

    1985-06-01

    Concentrated caustic is a primary cause of stress corrosion cracking and intergranular attack of Alloy 600 tubing in PWRs. However, temperature, electrochemical potential, stress, and metallurgical state all play a role. This study provides the quantitative evidence needed to develop models of crack growth and to devise effective countermeasures.

  15. Stress corrosion cracking of pressurizer instrumentation nozzles in the French 1300 MWe units

    SciTech Connect (OSTI)

    Alter, D.; Robin, Y.; Pichon, M.; Teissier, A.; Thomeret, B.

    1992-12-31

    The 1300 MWE French PWR pressurizers are equipped with nozzles through which instruments penetrate the pressure vessel. The nozzles are made from forged and bored bars of Inconel 600 mechanically expanded in the pressurizer wall. They are then manually welded with Inconel 182 coated electrodes to the internal stainless steel cladding of the pressuriser. To understand the origin of leaks occurring early in life and to assess the extent of the problem we undertook an analysis of the fabrication conditions. Field investigations were carried out by dye penetrant testing on the nozzle bore. Cracks have been found on 35 percent of the 119 tested penetrations. Destructive examination performed on 3 nozzles showed that the circumferential cracks did not go through the wall thickness. Laboratory investigations of the nozzle pulled from Nogent 1 confirmed that the crack morphology corresponded to that of primary water stress corrosion cracking. No correlation has been found between microstructure of the different heats of Alloy 600 and cracking. Nozzle mock-ups investigations allowed residual stress measurements by X-ray diffraction. Stress corrosion cracking tests, showed that only longitudinal cracks can be through-wall while both longitudinal and circumferential cracks are initiated on the internal surface. As a result, Electricite De France decided to replace the Inconel 600 nozzles by stainless steel ones with austenitic st. st. weld. Furthermore, a full inventory of the Alloy 600 parts contained in the primary circuit has been performed. For each localized parts an assessment of the risk of stress corrosion cracking is under progress by studying material structures, stress level, operating conditions and safety point of view.

  16. Stress Corrosion Cracking Model for High Level Radioactive-Waste Packages

    SciTech Connect (OSTI)

    P. Andresen; G. Gordon; S. Lu

    2004-10-05

    A stress corrosion cracking (SCC) model has been adapted for performance prediction of high level radioactive-waste packages to be emplaced in the proposed Yucca Mountain repository. For waste packages of the proposed Yucca Mountain repository, the outer barrier material is the highly corrosion-resistant Alloy UNS-N06022 (Alloy 22), the environment is represented by aqueous brine films present on the surface of the waste package from dripping or deliquescence of soluble salts present in any surface deposits, and the tensile stress is principally from weld induced residual stress. SCC has historically been separated into ''initiation'' and ''propagation'' phases. Initiation of SCC will not occur on a smooth surface if the surface stress is below a threshold value defined as the threshold stress. Cracks can also initiate at and propagate from flaws (or defects) resulting from manufacturing processes (such as welding); or that develop from corrosion processes such as pitting or dissolution of inclusions. To account for crack propagation, the slip dissolution/film rupture (SDFR) model is adopted to provide mathematical formulae for prediction of the crack growth rate. Once the crack growth rate at an initiated SCC is determined, it can be used by the performance assessment to determine the time to through-wall penetration for the waste package. This paper presents the development of the SDFR crack growth rate model based on technical information in the literature as well as experimentally determined crack growth rates developed specifically for Alloy UNS-N06022 in environments relevant to high level radioactive-waste packages of the proposed Yucca Mountain radioactive-waste repository. In addition, a seismic damage related SCC crack opening area density model is briefly described.

  17. Mono-2-ethylhexyl phthalate induces oxidative stress responses in human placental cells in vitro

    SciTech Connect (OSTI)

    Tetz, Lauren M.; Cheng, Adrienne A.; Korte, Cassandra S.; Giese, Roger W.; Wang, Poguang; Harris, Craig; Meeker, John D.; Loch-Caruso, Rita

    2013-04-01

    Di-2-ethylhexyl phthalate (DEHP) is an environmental contaminant commonly used as a plasticizer in polyvinyl chloride products. Exposure to DEHP has been linked to adverse pregnancy outcomes in humans including preterm birth, low birth-weight, and pregnancy loss. Although oxidative stress is linked to the pathology of adverse pregnancy outcomes, effects of DEHP metabolites, including the active metabolite, mono-2-ethylhexyl phthalate (MEHP), on oxidative stress responses in placental cells have not been previously evaluated. The objective of the current study is to identify MEHP-stimulated oxidative stress responses in human placental cells. We treated a human placental cell line, HTR-8/SVneo, with MEHP and then measured reactive oxygen species (ROS) generation using the dichlorofluorescein assay, oxidized thymine with mass-spectrometry, redox-sensitive gene expression with qRT-PCR, and apoptosis using a luminescence assay for caspase 3/7 activity. Treatment of HTR-8 cells with 180 ?M MEHP increased ROS generation, oxidative DNA damage, and caspase 3/7 activity, and resulted in differential expression of redox-sensitive genes. Notably, 90 and 180 ?M MEHP significantly induced mRNA expression of prostaglandin-endoperoxide synthase 2 (PTGS2), an enzyme important for synthesis of prostaglandins implicated in initiation of labor. The results from the present study are the first to demonstrate that MEHP stimulates oxidative stress responses in placental cells. Furthermore, the MEHP concentrations used were within an order of magnitude of the highest concentrations measured previously in human umbilical cord or maternal serum. The findings from the current study warrant future mechanistic studies of oxidative stress, apoptosis, and prostaglandins as molecular mediators of DEHP/MEHP-associated adverse pregnancy outcomes. - Highlights: ? MEHP increased reactive oxygen species, oxidative DNA damage, and caspase activity. ? MEHP induced expression of PTGS2, a gene important

  18. Classical and alternative macrophage activation in the lung following ozone-induced oxidative stress

    SciTech Connect (OSTI)

    Sunil, Vasanthi R.; Patel-Vayas, Kinal; Shen, Jianliang; Laskin, Jeffrey D.; Laskin, Debra L.

    2012-09-01

    Ozone is a pulmonary irritant known to cause oxidative stress, inflammation and tissue injury. Evidence suggests that macrophages play a role in the pathogenic response; however, their contribution depends on the mediators they encounter in the lung which dictate their function. In these studies we analyzed the effects of ozone-induced oxidative stress on the phenotype of alveolar macrophages (AM). Exposure of rats to ozone (2 ppm, 3 h) resulted in increased expression of 8-hydroxy-2?-deoxyguanosine (8-OHdG), as well as heme oxygenase-1 (HO-1) in AM. Whereas 8-OHdG was maximum at 24 h, expression of HO-1 was biphasic increasing after 3 h and 4872 h. Cleaved caspase-9 and beclin-1, markers of apoptosis and autophagy, were also induced in AM 24 h post-ozone. This was associated with increased bronchoalveolar lavage protein and cells, as well as matrix metalloproteinase (MMP)-2 and MMP-9, demonstrating alveolar epithelial injury. Ozone intoxication resulted in biphasic activation of the transcription factor, NF?B. This correlated with expression of monocyte chemotactic protein?1, inducible nitric oxide synthase and cyclooxygenase?2, markers of proinflammatory macrophages. Increases in arginase-1, Ym1 and galectin-3 positive anti-inflammatory/wound repair macrophages were also observed in the lung after ozone inhalation, beginning at 24 h (arginase-1, Ym1), and persisting for 72 h (galectin-3). This was associated with increased expression of pro-surfactant protein-C, a marker of Type II cell proliferation and activation, important steps in wound repair. These data suggest that both proinflammatory/cytotoxic and anti-inflammatory/wound repair macrophages are activated early in the response to ozone-induced oxidative stress and tissue injury. -- Highlights: ? Lung macrophages are highly sensitive to ozone induced oxidative stress. ? Ozone induces autophagy and apoptosis in lung macrophages. ? Proinflammatory and wound repair macrophages are activated early after ozone

  19. Residual stress and damage-induced critical fracture on CO2 laser treated fused silica

    SciTech Connect (OSTI)

    Matthews, M; Stolken, J; Vignes, R; Norton, M

    2009-11-02

    Localized damage repair and polishing of silica-based optics using mid- and far-IR CO{sub 2} lasers has been shown to be an effective method for increasing optical damage threshold in the UV. However, it is known that CO{sub 2} laser heating of silicate surfaces can lead to a level of residual stress capable of causing critical fracture either during or after laser treatment. Sufficient control of the surface temperature as a function of time and position is therefore required to limit this residual stress to an acceptable level to avoid critical fracture. In this work they present the results of 351 nm, 3 ns Gaussian damage growth experiments within regions of varying residual stress caused by prior CO{sub 2} laser exposures. Thermally stressed regions were non-destructively characterized using polarimetry and confocal Raman microscopy to measure the stress induced birefringence and fictive temperature respectively. For 1 {approx} 40s square pulse CO{sub 2} laser exposures created over 0.5-1.25 kW/cm{sup 2} with a 1-3 mm 1/e{sup 2} diameter beam (T{sub max} {approx} 1500-3000 K), the critical damage site size leading to fracture increases weakly with peak temperature, but shows a stronger dependence on cooling rate, as predicted by finite element hydrodynamics simulations. Confocal micro-Raman was used to probe structural changes to the glass over different thermal histories and indicated a maximum fictive temperature of 1900K for T{sub max} {ge} 2000 K. The effect of cooling rate on fictive temperature caused by CO{sub 2} laser heating are consistent with finite element calculations based on a Tool-Narayanaswamy relaxation model.

  20. Thin film polymer stress measurement using piezoresistive anisotropically etched pressure sensors

    SciTech Connect (OSTI)

    Bitko, G.; Harries, R.; Matkin, J.; McNeil, A.C.; Monk, D.J.; Shah, M.; Wertz, J.

    1997-05-01

    Silicon bulk micromachined piezoresistive pressure sensors are very sensitive to applied stresses: that is, applied pressure and/or packaging-related stresses. Device encapsulation has been observed to affect the electrical output of the pressure sensor significantly. The magnitude of the zero applied pressure output voltage (i.e., the offset voltage) that can be attributed to a thin film encapsulant is proportional to the magnitude of the room-temperature thermal stress of that film. Parylene C coatings have been used as encapsulants in this work. Finite element and analytical modeling techniques were used to evaluate the effect of material property variation on the offset of a pressure sensor. A simple, linear expression of offset as a function of a material property parametric group, that includes: parylene thickness, parylene biaxial modulus, parylene CTE, silicon thickness, and annealing temperature; has been established. Experimental analysis of parylene coated pressure sensors and parylene coated silicon and gallium arsenide wafers was performed to confirm the resulting model. Known variations in parylene material properties caused by processing (i.e., uncontrolled deposition, annealing, and high temperature storage) have been used as an experimental vehicle for this purpose. An empirical relationship between offset voltage on parylene coated devices and room-temperature thermal stress on parylene coated wafers that have been exposed to the same processing is a linear expression with a similar slope to the modeling results. Furthermore, stress measurements from parylene coated silicon wafers and parylene coated gallium arsenide wafers have been used to estimate the parylene biaxial modulus (approximately 5,000 MPa) and the parylene CTE (approximately 0 ppm/C) independently. These material properties were observed to shift following parylene annealing and high temperature storage exposure experiments in a manner that is consistent with the established model.

  1. Assessment of Initial Test Conditions for Experiments to Assess Irradiation Assisted Stress Corrosion Cracking Mechanisms

    SciTech Connect (OSTI)

    Busby, Jeremy T; Gussev, Maxim N

    2011-04-01

    Irradiation-assisted stress corrosion cracking is a key materials degradation issue in today s nuclear power reactor fleet and affects critical structural components within the reactor core. The effects of increased exposure to irradiation, stress, and/or coolant can substantially increase susceptibility to stress-corrosion cracking of austenitic steels in high-temperature water environments. . Despite 30 years of experience, the underlying mechanisms of IASCC are unknown. Extended service conditions will increase the exposure to irradiation, stress, and corrosive environment for all core internal components. The objective of this effort within the Light Water Reactor Sustainability program is to evaluate the response and mechanisms of IASCC in austenitic stainless steels with single variable experiments. A series of high-value irradiated specimens has been acquired from the past international research programs, providing a valuable opportunity to examine the mechanisms of IASCC. This batch of irradiated specimens has been received and inventoried. In addition, visual examination and sample cleaning has been completed. Microhardness testing has been performed on these specimens. All samples show evidence of hardening, as expected, although the degree of hardening has saturated and no trend with dose is observed. Further, the change in hardening can be converted to changes in mechanical properties. The calculated yield stress is consistent with previous data from light water reactor conditions. In addition, some evidence of changes in deformation mode was identified via examination of the microhardness indents. This analysis may provide further insights into the deformation mode under larger scale tests. Finally, swelling analysis was performed using immersion density methods. Most alloys showed some evidence of swelling, consistent with the expected trends for this class of alloy. The Hf-doped alloy showed densification rather than swelling. This observation may be

  2. Multiaxial plasticity and fatigue life prediction in coiled tubing

    SciTech Connect (OSTI)

    Tipton, S.M.

    1996-12-31

    Coiled tubing is being used increasingly in the oil well drilling and servicing industry. Continuous steel tubing of structural dimensions (up to 89 mm or 3.5 in. in diameter) is wound onto a large-diameter reel for repeated deployment into and out of a well bore. The bending strain range associated with each wrap-unwrap cycle can exceed 3% with lives well below 100 cycles. During constant internal pressure fatigue testing, tubing has been observed to grow in diameter by as much as 30%. This paper describes an analytical model to predict the fatigue behavior of coiled tubing subjected to variable pressure service conditions. The approach utilizes standard low-cycle fatigue data but requires additional experimental results from constant pressure fatigue testing. The algorithm is based on estimates of biaxial ratcheting from an incremental plasticity model using a hybrid associated flow rule, a modified kinematic hardening rule with multiple von Mises yield surfaces, and a specialized limit surface concept. An empirical damage parameter was formulated based on constant pressure fatigue data using mean and fluctuating von Mises equivalent strain components occurring throughout the life of a section of tubing. This parameters is used with the Palmgren-Miner definition of cumulative damage to track damage that is accumulating nonlinearly under constant or variable pressure histories. Modifications to standard incremental plasticity components and implementation assumptions used to apply the model are presented and discussed. The predictive capability of the model is demonstrated relative to data generated under constant and variable pressure histories.

  3. Comparison of residual stresses in Inconel 718 simple parts made by electron beam melting and direct laser metal sintering

    SciTech Connect (OSTI)

    Kolbus, Lindsay M; Payzant, E Andrew; Cornwell, Paris A; Watkins, Thomas R; Babu, Sudarsanam Suresh; Dehoff, Ryan R; Duty, Chad E

    2015-01-01

    Residual stress profiles were mapped using neutron diffraction in two simple prism builds of Inconel 718: one fabricated with electron beam melting and the other with direct laser sintering. Spatially indexed stress-free cubes were obtained by EDM sectioning equivalent prisms of similar shape. The (311) interplanar spacing examined for the EDM sectioned sample was compared to the interplanar spacings calculated to fulfill force and moment balance. We have shown that Applying force and moment balance is a necessary supplement to the measurements for the stress-free cubes with respect to accurate stress calculations in additively manufactured components. In addition, our work has shown that residual stresses in electron beam melting parts are much smaller than that of direct laser metal sintering parts.

  4. Comparison of residual stresses in Inconel 718 simple parts made by electron beam melting and direct laser metal sintering

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Payzant, E Andrew; Cornwell, Paris A; Watkins, Thomas R; Babu, Sudarsanam Suresh; Dehoff, Ryan R; Duty, Chad E

    2015-01-01

    Residual stress profiles were mapped using neutron diffraction in two simple prism builds of Inconel 718: one fabricated with electron beam melting and the other with direct laser sintering. Spatially indexed stress-free cubes were obtained by EDM sectioning equivalent prisms of similar shape. The (311) interplanar spacing examined for the EDM sectioned sample was compared to the interplanar spacings calculated to fulfill force and moment balance. We have shown that Applying force and moment balance is a necessary supplement to the measurements for the stress-free cubes with respect to accurate stress calculations in additively manufactured components. In addition, our workmore » has shown that residual stresses in electron beam melting parts are much smaller than that of direct laser metal sintering parts.« less

  5. Simulation of Distortion and Residual Stress Development During Heat Treatment of Steel Castings

    SciTech Connect (OSTI)

    Beckermann, Christoph; Carlson, Kent

    2011-07-22

    Heat treatment and associated processing, such as quenching, are critical during high strength steel casting production. These processes must be managed closely to prevent thermal and residual stresses that may result in distortion, cracking (particularly after machining), re-work, and weld repair. The risk of casting distortion limits aggressive quenching that can be beneficial to the process and yield an improved outcome. As a result of these distortions, adjustments must be made to the casting or pattern design, or tie bars must be added. Straightening castings after heat treatments can be both time-consuming and expensive. Residual stresses may reduce a casting's overall service performance, possibly resulting in catastrophic failure. Stress relieving may help, but expends additional energy in the process. Casting software is very limited in predicting distortions during heat treatment, so corrective measures most often involve a tedious trial-and-error procedure. An extensive review of existing heat treatment residual stress and distortion modeling revealed that it is vital to predict the phase transformations and microstructure of the steel along with the thermal stress development during heat treatment. After reviewing the state-of-the-art in heat treatment residual stress and distortion modeling, an existing commercial code was selected because of its advanced capabilities in predicting phase transformations, the evolving microstructure and related properties along with thermal stress development during heat treatment. However, this software was developed for small parts created from forgings or machined stock, and not for steel castings. Therefore, its predictive capabilities for heat treatment of steel castings were investigated. Available experimental steel casting heat treatment data was determined to be of insufficient detail and breadth, and so new heat treatment experiments were designed and performed, casting and heat treating modified versions of

  6. Systemic inflammatory changes and increased oxidative stress in rural Indian women cooking with biomass fuels

    SciTech Connect (OSTI)

    Dutta, Anindita; Department of Experimental Hematology, Chittaranjan National Cancer Institute, 37, S.P. Mukherjee Road, Kolkata-700 026 ; Ray, Manas Ranjan; Banerjee, Anirban

    2012-06-15

    The study was undertaken to investigate whether regular cooking with biomass aggravates systemic inflammation and oxidative stress that might result in increase in the risk of developing cardiovascular disease (CVD) in rural Indian women compared to cooking with a cleaner fuel like liquefied petroleum gas (LPG). A total of 635 women (median age 36 years) who cooked with biomass and 452 age-matched control women who cooked with LPG were enrolled. Serum interleukin-6 (IL-6), C-reactive protein (CRP), tumor necrosis factor-alpha (TNF-?) and interleukin-8 (IL-8) were measured by ELISA. Generation of reactive oxygen species (ROS) by leukocytes was measured by flow cytometry, and erythrocytic superoxide dismutase (SOD) was measured by spectrophotometry. Hypertension was diagnosed following the Seventh Report of the Joint Committee. Tachycardia was determined as pulse rate > 100 beats per minute. Particulate matter of diameter less than 10 and 2.5 ?m (PM{sub 10} and PM{sub 2.5}, respectively) in cooking areas was measured using real-time aerosol monitor. Compared with control, biomass users had more particulate pollution in indoor air, their serum contained significantly elevated levels of IL-6, IL-8, TNF-? and CRP, and ROS generation was increased by 37% while SOD was depleted by 41.5%, greater prevalence of hypertension and tachycardia compared to their LPG-using neighbors. PM{sub 10} and PM{sub 2.5} levels were positively associated with markers of inflammation, oxidative stress and hypertension. Inflammatory markers correlated with raised blood pressure. Cooking with biomass exacerbates systemic inflammation, oxidative stress, hypertension and tachycardia in poor women cooking with biomass fuel and hence, predisposes them to increased risk of CVD development compared to the controls. Systemic inflammation and oxidative stress may be the mechanistic factors involved in the development of CVD. -- Highlights: ? Effect of chronic biomass smoke exposure on cardiovascular

  7. Fluoride-elicited developmental testicular toxicity in rats: Roles of endoplasmic reticulum stress and inflammatory response

    SciTech Connect (OSTI)

    Zhang, Shun; Jiang, Chunyang; Liu, Hongliang; Guan, Zhizhong; Zeng, Qiang; Zhang, Cheng; Lei, Rongrong; Xia, Tao; Gao, Hui; Yang, Lu; Chen, Yihu; Wu, Xue; Zhang, Xiaofei; Cui, Yushan; Yu, Linyu; Wang, Zhenglun; Wang, Aiguo

    2013-09-01

    Long-term excessive fluoride intake is known to be toxic and can damage a variety of organs and tissues in the human body. However, the molecular mechanisms underlying fluoride-induced male reproductive toxicity are not well understood. In this study, we used a rat model to simulate the situations of human exposure and aimed to evaluate the roles of endoplasmic reticulum (ER) stress and inflammatory response in fluoride-induced testicular injury. SpragueDawley rats were administered with sodium fluoride (NaF) at 25, 50 and 100 mg/L via drinking water from pre-pregnancy to gestation, birth and finally to post-puberty. And then the testes of male offspring were studied at 8 weeks of age. Our results demonstrated that fluoride treatment increased MDA accumulation, decreased SOD activity, and enhanced germ cell apoptosis. In addition, fluoride elevated mRNA and protein levels of glucose-regulated protein 78 (GRP78), inositol requiring ER-to-nucleus signal kinase 1 (IRE1), and C/EBP homologous protein (CHOP), indicating activation of ER stress signaling. Furthermore, fluoride also induced testicular inflammation, as manifested by gene up-regulation of tumor necrosis factor-? (TNF-?), interleukin-1? (IL-1?), inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in a nuclear factor-?B (NF-?B)-dependent manner. These were associated with marked histopathological lesions including injury of spermatogonia, decrease of spermatocytes and absence of elongated spermatids, as well as severe ultrastructural abnormalities in testes. Taken together, our results provide compelling evidence that ER stress and inflammation would be novel and significant mechanisms responsible for fluoride-induced disturbance of spermatogenesis and germ cell loss in addition to oxidative stress. - Highlights: We used a rat model to simulate the situations of human fluoride (F) exposure. Developmental F exposure induces testicular damage related with oxidative stress. Endoplasmic

  8. Comparison of calculated and observed cyclic stress-strain relationships for Inconel Alloy 625 at 650 to 1100/sup 0/C

    SciTech Connect (OSTI)

    Purohit, A.; Ewing, T.F.; Thiele, U.

    1983-06-01

    It is concluded that both the bilinear stress-strain and creep laws used with the ANSYS spar element model and the stress relaxation method are able to describe and predict fatigue behavior of Inconel Alloy 625.

  9. Characterization of Residual Stress as a Function of Friction Stir Welding Parameters in Oxide Dispersion Strengthened (ODS) Steel MA956

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Brewer, Luke N.; Bennett, Martin S.; Baker, B. W.; Payzant, E. Andrew; Kolbus, Lindsay M.

    2015-09-08

    This article characterizes the residual stresses generated by friction stir welding of oxide dispersion strengthened steel MA956 over a series of welding conditions. A plate of MA956 steel was friction stir welded at three conditions: 500 rpm/25 millimeters per minute (mmpm), 400 rpm/50 mmpm and 400 rpm/100 mmpm. The residual stresses across these welds were measured using both x-ray and neutron diffraction techniques. Longitudinal residual stresses up to eighty percent of the yield strength were observed for the 400 rpm/100 mmpm condition. Increasing the traverse rate while holding the rotational speed fixed increased the residual stress levels in the stirmore » zone and at the stir zone-thermomechanically affected zone interface. The stress profiles displayed the characteristic M shape, and the asymmetry between advancing and retreating stress peaks was limited, occurring mainly on the root side of the weld. The large magnitude of the stresses was maintained throughout the thickness of the plates.« less

  10. Thermally activated low temperature creep and primary water stress corrosion cracking of NiCrFe alloys

    SciTech Connect (OSTI)

    Hall, M.M. Jr.

    1993-10-01

    A phenomenological SCC-CGR model is developed based on an apriori assumption that the SCC-CGR is controlled by low temperature creep (LTC). This mode of low temperature time dependent deformation occurs at stress levels above the athermal flow stress by a dislocation glide mechanism that is thermally activated and may be environmentally assisted. The SCC-CGR model equations developed contain thermal activation parameters descriptive of the dislocation creep mechanism. Thermal activation parameters are obtained by fitting the CGR model to SCC-CGR data obtained on Alloy 600 and Alloy X-750. These SCC-CGR activation parameters are compared to LTC activation parameters obtained from stress relaxation tests. When the high concentration of hydrogen at the tip of an SCC crack is considered, the SCC-CGR activation energies and rate sensitivities are shown to be quantitatively consistent with hydrogen reducing the activation energy and increasing the strain rate sensitivity in LTC stress relaxation tests. Stress dependence of SCC-CGR activation energy consistent with that found for the LTC activation energy. Comparisons between temperature dependence of the SCC-CGR stress sensitivity and LTC stress sensitivity provide a basis for speculation on effects of hydrogen and solute carbon on SCC crack growth rates.

  11. Method for improve x-ray diffraction determinations of residual stress in nickel-base alloys

    DOE Patents [OSTI]

    Berman, Robert M.; Cohen, Isadore

    1990-01-01

    A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys which comprises covering part of a predetermined area of the surface of a nickel-base alloy with a dispersion, exposing the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample.

  12. A STUDY OF CORROSION AND STRESS CORROSION CRACKING OF CARBON STEEL NUCLEAR WASTE STORAGE TANKS

    SciTech Connect (OSTI)

    BOOMER, K.D.

    2007-08-21

    The Hanford reservation Tank Farms in Washington State has 177 underground storage tanks that contain approximately 50 million gallons of liquid legacy radioactive waste from cold war plutonium production. These tanks will continue to store waste until it is treated and disposed. These nuclear wastes were converted to highly alkaline pH wastes to protect the carbon steel storage tanks from corrosion. However, the carbon steel is still susceptible to localized corrosion and stress corrosion cracking. The waste chemistry varies from tank to tank, and contains various combinations of hydroxide, nitrate, nitrite, chloride, carbonate, aluminate and other species. The effect of each of these species and any synergistic effects on localized corrosion and stress corrosion cracking of carbon steel have been investigated with electrochemical polarization, slow strain rate, and crack growth rate testing. The effect of solution chemistry, pH, temperature and applied potential are all considered and their role in the corrosion behavior will be discussed.

  13. Method for improving x-ray diffraction determinations of residual stress in nickel-base alloys

    DOE Patents [OSTI]

    Berman, R.M.; Cohen, I.

    1988-04-26

    A process for improving the technique of measuring residual stress by x-ray diffraction in pieces of nickel-base alloys is discussed. Part of a predetermined area of the surface of a nickel-base alloy is covered with a dispersion. This exposes the covered and uncovered portions of the surface of the alloy to x-rays by way of an x-ray diffractometry apparatus, making x-ray diffraction determinations of the exposed surface, and measuring the residual stress in the alloy based on these determinations. The dispersion is opaque to x-rays and serves a dual purpose, since it masks off unsatisfactory signals such that only a small portion of the surface is measured, and it supplies an internal standard by providing diffractogram peaks comparable to the peaks of the nickel alloy so that the alloy peaks can be very accurately located regardless of any sources of error external to the sample. 2 figs.

  14. How sulphate-reducing microorganisms cope with stress: Lessons from systems biology

    SciTech Connect (OSTI)

    Zhou, J.; He, Q.; Hemme, C.L.; Mukhopadhyay, A.; Hillesland, K.; Zhou, A.; He, Z.; Nostrand, J.D. Van; Hazen, T.C.; Stahl, D.A.; Wall, J.D.; Arkin, A.P.

    2011-04-01

    Sulphate-reducing microorganisms (SRMs) are a phylogenetically diverse group of anaerobes encompassing distinct physiologies with a broad ecological distribution. As SRMs have important roles in the biogeochemical cycling of carbon, nitrogen, sulphur and various metals, an understanding of how these organisms respond to environmental stresses is of fundamental and practical importance. In this Review, we highlight recent applications of systems biology tools in studying the stress responses of SRMs, particularly Desulfovibrio spp., at the cell, population, community and ecosystem levels. The syntrophic lifestyle of SRMs is also discussed, with a focus on system-level analyses of adaptive mechanisms. Such information is important for understanding the microbiology of the global sulphur cycle and for developing biotechnological applications of SRMs for environmental remediation, energy production, biocorrosion control, wastewater treatment and mineral recovery.

  15. Conservation of Modules but not Phenotype in Bacterial Response to Environmental Stress

    SciTech Connect (OSTI)

    Timberlake, Sonia; Joachimiak, Marcin; Joyner, Dominique; Chakraborty, Romy; Baumohl, Jason; Dehal, Paramvir; Arkin, Adam; Hazen, Terry; Alm, Eric

    2010-05-17

    Microbes live in changing environments and change their phenotype via gene regulation in response. Although this transcriptional response is important for fitness, very little is known about how it evolves in microbes. We started by asking a number of high-level questions about the evolution of transcriptional phenotype: (1) To what extent is transcriptional response conserved, i.e. do conserved genes respond similarly to the same condition; (2) To what extent are transcriptional modules conserved; and (3) Does there exist a general stress response to a variety of stressors? To illuminate these questions, we analyzed more than 500 microarray experiments across the bacterial domain. We looked for conservation of transcriptional regulation both in close sister species and vastly divergent clades. In addition, we produced and analyzed an extensive in-house compendium of environmental stress data in three metal-reducing bacteria.

  16. Packaging strategies for printed circuit board components. Volume I, materials & thermal stresses.

    SciTech Connect (OSTI)

    Neilsen, Michael K.; Austin, Kevin N.; Adolf, Douglas Brian; Spangler, Scott W.; Neidigk, Matthew Aaron; Chambers, Robert S.

    2011-09-01

    Decisions on material selections for electronics packaging can be quite complicated by the need to balance the criteria to withstand severe impacts yet survive deep thermal cycles intact. Many times, material choices are based on historical precedence perhaps ignorant of whether those initial choices were carefully investigated or whether the requirements on the new component match those of previous units. The goal of this program focuses on developing both increased intuition for generic packaging guidelines and computational methodologies for optimizing packaging in specific components. Initial efforts centered on characterization of classes of materials common to packaging strategies and computational analyses of stresses generated during thermal cycling to identify strengths and weaknesses of various material choices. Future studies will analyze the same example problems incorporating the effects of curing stresses as needed and analyzing dynamic loadings to compare trends with the quasi-static conclusions.

  17. Pressure, stress, and strain distribution in the double-stage diamond anvil cell

    SciTech Connect (OSTI)

    Lobanov, Sergey S.; Prakapenka, Vitali B.; Prescher, Clemens; Konôpková, Zuzana; Liermann, Hanns-Peter; Crispin, Katherine L.; Zhang, Chi; Goncharov, Alexander F.

    2015-07-21

    Double stage diamond anvil cells (DACs) of two designs have been assembled and tested. We used a standard symmetric DAC with flat or beveled culets as a primary stage and CVD microanvils machined by a focused ion beam as a second. We evaluated pressure, stress, and strain distributions in gold and a mixture of gold and iron as well as in secondary anvils using synchrotron x-ray diffraction with a micro-focused beam. A maximum pressure of 240 GPa was reached independent of the first stage anvil culet size. We found that the stress field generated by the second stage anvils is typical of conventional DAC experiments. The maximum pressures reached are limited by strains developing in the secondary anvil and by cupping of the first stage diamond anvil in the presented experimental designs. Also, our experiments show that pressures of several megabars may be reached without sacrificing the first stage diamond anvils.

  18. Tensile behavior and flow stress anisotropy of accumulative roll bonded Cu-Nb nanolaminates

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nizolek, Thomas; Beyerlein, Irene J.; Mara, Nathan A.; Avallone, Jaclyn T.; Pollock, Tresa M.

    2016-02-01

    The flow stress, ductility, and in-plane anisotropy are evaluated for bulk accumulative roll bonded copper-niobium nanolaminates with layer thicknesses ranging from 1.8 μm to 15 nm. Uniaxial tensile tests conducted parallel to the rolling direction and transverse direction demonstrate that ductility generally decreases with decreasing layer thickness; however, at 30 nm, both high strengths (1200 MPa) and significant ductility (8%) are achieved. The yield strength increases monotonically with decreasing layer thickness, consistent with the Hall-Petch relationship, and significant in-plane flow stress anisotropy is observed. As a result, Taylor polycrystal modeling is used to demonstrate that crystallographic texture is responsible formore » the in-plane anisotropy and that the effects of texture dominate even at nanoscale layer thicknesses.« less

  19. Thick, low-stress films, and coated substrates formed therefrom, and methods for making same

    DOE Patents [OSTI]

    Henager, Jr., Charles H.; Knoll, Robert W.

    1992-01-01

    Stress-induced deformation, and the damage resulting therefrom, increases with film thickness. The overcoming of excessive stress by the use of the Si-Al-N film material of the present invention, permits the formation of thick films that are necessary for certain of the above described applications. The most likely use for the subject film materials, other than their specialized views as an optical film, is for microelectronic packaging of components on silicon substrates. In general, the subject films have excellent adherence to the underlying substrate, a high degree of hardness and durability, and are excellent insulators. Prior art elevated temperature deposition processes cannot meet the microelectronic packaging temperature formation constraints. The process of the present invention is conducted under non-elevated temperature conditions, typically 500.degree. C. or less.

  20. Semi-flexible gas-insulated transmission line using electric field stress shields

    DOE Patents [OSTI]

    Cookson, A.H.; Dale, S.J.; Bolin, P.C.

    1982-12-28

    A gas-insulated transmission line includes an outer sheath, an inner conductor, an insulating gas electrically insulating the inner conductor from the outer sheath, and insulating supports insulatably supporting the inner conductor within the outer sheath. The inner conductor is provided with flexibility by use of main conductor sections which are joined together through a conductor hub section and flexible flexing elements. Stress shields are provided to control the electric field at the locations of the conductor hub sections where the insulating supports are contacting the inner conductor. The flexing elements and the stress shields may also be utilized in connection with a plug and socket arrangement for providing electrical connection between main conductor sections. 10 figs.

  1. Identification of crystalline elastic anisotropy in PZT ceramics from in-situ blocking stress measurements

    SciTech Connect (OSTI)

    Daniel, L.; Hall, D. A.; Withers, P. J.; Webber, K. G.; King, A.

    2014-05-07

    High energy x-ray diffraction measurements of lattice strains were performed on a rhombohedral Lead Zirconate Titanate ceramic (PZT 55-45) under combinations of applied electric field and compressive stress. These measurements allow the construction of blocking stress curves for different sets of crystallographic orientations which reflect the single crystal elastic anisotropy. A micro-mechanical interpretation of the results is then proposed. Assuming cubic symmetry for the crystalline elastic stiffness tensor and isotropy for the macroscopic elastic properties, the elastic properties of the single crystal are extracted from the measured data. An anisotropy ratio close to 0.3 is found (compared to 1 for isotropic materials). The high level of anisotropy found in this work suggests that crystalline elastic anisotropy should not be neglected in the modelling of ferroelectric materials.

  2. Stress state and nature of failure of detonation coatings based on alumina

    SciTech Connect (OSTI)

    Anisimov, M.I.; Galeev, I.M.; Gol`dfain, V.N.

    1995-03-01

    Detonation coatings based on alumina are used on an increasing scale in industry for increasing the corrosion and wear resistance of materials. The physicomechanical and service characteristics of coatings are determined by the stress state . In this work, investigations were carried out into the distribution of residual phase stresses in the layer and the nature of failure of coatings in combined deformation with the substrate at T = 600{degrees}C. Coatings of electrocorundum powder of 24A grade with a grain size of M40 were deposited on a substrate of KhN78 alloy. In certain cases, an intermediate layer of PN85Yu15 powder was deposited on the substrate prior to spraying. Spraying was carried out in ADK Prometei equipment using an oxygen-acetylene mixture. The thickness of the coatings was 0.4-0.5 mm.

  3. Oxidation growth stresses in an alumina-forming ferritic steel measured by creep deflection

    SciTech Connect (OSTI)

    Saunders, S.R.J.; Gohil, D.D.; Osgerby, S.

    1997-10-01

    Deflection tests have been used to estimate the stresses developed in the alumina layer formed during short-term oxidation of a Fe-22Cr-5Al-0.3Y Fecralloy steel at 1000{degrees}C. Elastic analysis of the deflecting specimen is inappropriate under these test conditions because of the low creep strength of the alloy. Accordingly, a recent creep analysis has been used in this work using currently determined creep properties of the alloy substrate. The results of the analysis show that for the thin oxides produced (< 1 {mu}m), the planar stress within the oxide layer is everywhere compressive. Average values are approximately 850 MPa after 0.5 hr oxidation but reduce to < 200 MPa after 6.5 hr. These values are very much less than would be expected under conditions of elastic deformation.

  4. Semi-flexible gas-insulated transmission line using electric field stress shields

    DOE Patents [OSTI]

    Cookson, Alan H.; Dale, Steinar J.; Bolin, Philip C.

    1982-12-28

    A gas-insulated transmission line includes an outer sheath, an inner conductor, an insulating gas electrically insulating the inner conductor from the outer sheath, and insulating supports insulatably supporting the inner conductor within the outer sheath. The inner conductor is provided with flexibility by use of main conductor sections which are joined together through a conductor hub section and flexible flexing elements. Stress shields are provided to control the electric field at the locations of the conductor hub sections where the insulating supports are contacting the inner conductor. The flexing elements and the stress shields may also be utilized in connection with a plug and socket arrangement for providing electrical connection between main conductor sections.

  5. Nonenzymatic Role for WRN in Preserving Nascent DNA Strands after Replication Stress

    SciTech Connect (OSTI)

    Su, Fengtao; Mukherjee, Shibani; Yang, Yanyong; Mori, Eiichiro; Bhattacharya, Souparno; Kobayashi, Junya; Yannone, Steven  M.; Chen, David  J.; Asaithamby, Aroumougame

    2014-11-20

    WRN, the protein defective in Werner syndrome (WS), is a multifunctional nuclease involved in DNA damage repair, replication, and genome stability maintenance. It was assumed that the nuclease activities of WRN were critical for these functions. Here, we report a nonenzymatic role for WRN in preserving nascent DNA strands following replication stress. We found that lack of WRN led to shortening of nascent DNA strands after replication stress. Furthermore, we discovered that the exonuclease activity of MRE11 was responsible for the shortening of newly replicated DNA in the absence of WRN. Mechanistically, the N-terminal FHA domain of NBS1 recruits WRN to replication-associated DNA double-stranded breaks to stabilize Rad51 and to limit the nuclease activity of its C-terminal binding partner MRE11. Thus, this previously unrecognized nonenzymatic function of WRN in the stabilization of nascent DNA strands sheds light on the molecular reason for the origin of genome instability in WS individuals.

  6. Residual stress relief due to fatigue in tetragonal lead zirconate titanate ceramics

    SciTech Connect (OSTI)

    Hall, D. A.; Mori, T. [School of Materials, University of Manchester, Grosvenor St., Manchester M1 7HS (United Kingdom); Comyn, T. P. [Institute for Materials Research, Woodhouse Lane, University of Leeds, LS2 9JT (United Kingdom); Ringgaard, E. [Meggitt Sensing Systems, Hejreskovvej 18A, 3490 Kvistgaard (Denmark); Wright, J. P. [ESRF, 6 Rue Jules Horowitz, BP-220, 38043 Grenoble Cedex (France)

    2013-07-14

    High energy synchrotron XRD was employed to determine the lattice strain {epsilon}{l_brace}111{r_brace}and diffraction peak intensity ratio R{l_brace}200{r_brace}in tetragonal PZT ceramics, both in the virgin poled state and after a bipolar fatigue experiment. It was shown that the occurrence of microstructural damage during fatigue was accompanied by a reduction in the gradient of the {epsilon}{l_brace}111{r_brace}-cos{sup 2} {psi} plot, indicating a reduction in the level of residual stress due to poling. In contrast, the fraction of oriented 90 Degree-Sign ferroelectric domains, quantified in terms of R{l_brace}200{r_brace}, was not affected significantly by fatigue. The change in residual stress due to fatigue is interpreted in terms of a change in the average elastic stiffness of the polycrystalline matrix due to the presence of inter-granular microcracks.

  7. Process for the electrodeposition of low stress nickel-manganese alloys

    DOE Patents [OSTI]

    Kelly, James John; Goods, Steven Howard; Yang, Nancy Yuan-Chi; Cadden, Charles Henry

    2005-06-07

    A process for electrodepositing a low stress nickel-manganese multilayer alloy on an electrically conductive substrate is provided. The process includes the steps of immersing the substrate in an electrodeposition solution containing a nickel salt and a manganese salt and repeatedly passing an electric current through an immersed surface of the substrate. The electric current is alternately pulsed for predetermined durations between a first electrical current that is effective to electrodeposit nickel and a second electrical current that is effective to electrodeposit nickel and manganese. A multilayered alloy having adjacent layers of nickel and a nickel-manganese alloy on the immersed surface of the substrate is thereby produced. The resulting multilayered alloy exhibits low internal stress, high strength and ductility, and high strength retention upon exposure to heat.

  8. Epitaxy and stress of MgO/GaAs(001) heterostructures

    SciTech Connect (OSTI)

    Wang, Shibo; Sarkar, Anirban; Gruber, Markus; Koch, Reinhold

    2013-10-21

    We report on the preparation of epitaxial MgO film on GaAs(001) substrates by molecular beam epitaxy at growth temperature of 20–200 °C. Reflection high energy electron diffraction, x-ray diffraction, and high resolution transmission electron microscopy reveal the growth of ordered crystalline cubic MgO(001) film at ∼200 °C with MgO(001)[100]|| GaAs(001)[100] and a 4 : 3 lattice registry. The surface of the MgO films, characterized by atomic force microscopy, exhibits a root mean square roughness of only 0.5 nm. In situ stress measurements reveal tensile stress as low as 1.7 GPa for a growth temperature of 200 °C in good agreement with the calculated residual misfit strain.

  9. Effects of vacuum exposure on stress and spectral shift of high reflective coatings

    SciTech Connect (OSTI)

    Stolz, C.J.; Taylor, J.R.; Eickelberg, W.K.; Lindh, J.D.

    1992-06-01

    The Atomic Vapor Laser Isotope Laser Separation (AVLIS) program operates the world`s largest average power dye laser; the dye laser beams are combined, formatted, and transported in vacuum. The optical system is aligned at atmosphere, while the system must meet requirements in vacuum. Therefore, coating performance must be characterized in both atmosphere and vacuum. Changes in stress and spectral shift in ambient and vacuum environments are reported for conventional and dense multilayer dielectric coatings.

  10. Effects of vacuum exposure on stress and spectral shift of high reflective coatings

    SciTech Connect (OSTI)

    Stolz, C.J.; Taylor, J.R.; Eickelberg, W.K.; Lindh, J.D.

    1992-06-01

    The Atomic Vapor Laser Isotope Laser Separation (AVLIS) program operates the world's largest average power dye laser; the dye laser beams are combined, formatted, and transported in vacuum. The optical system is aligned at atmosphere, while the system must meet requirements in vacuum. Therefore, coating performance must be characterized in both atmosphere and vacuum. Changes in stress and spectral shift in ambient and vacuum environments are reported for conventional and dense multilayer dielectric coatings.

  11. Natural Gas Issues and Trends - High prices show stresses in New England

    U.S. Energy Information Administration (EIA) Indexed Site

    natural gas delivery system - Energy Information Administration High prices show stresses in New England natural gas delivery system Released: February 7, 2014 Abstract. Since 2012, limited supply from the Canaport and Everett liquefied natural gas (LNG) terminals coupled with congestion on the Tennessee and Algonquin pipelines has led to winter natural gas price spikes in New England. The problem continued in the winter of 2013-14, as indicated by New England's forward basis for January

  12. SLUDGE BATCH SUPPLEMENTAL SRAT RUNS EFFECTS OF YIELD STRESS AND CYCLE TIME INCREASE

    SciTech Connect (OSTI)

    Fernandez, A.

    2010-08-10

    The Defense Waste Processing Facility (DWPF) has transitioned from Sludge Batch 5 (SB5) processing to Sludge Batch 6 (SB6) processing. Phase III-Tank 40 Chemical Process Cell (CPC) flowsheet simulations have been completed to determine the initial processing conditions for the DWPF transition. The impact of higher yield stress (SB-25) and cycle time extension (SB6-26) on the physical and chemical effects of SB6 processing during the SRAT (Sludge Receipt and Adjustment Tank) cycle were evaluated. No significant impacts on the SRAT chemistry were noted during the higher yield stress run. In particular, no impact on mercury stripping was noted, indicating that settling of elemental mercury was not the primary factor in the low mercury recovery noted in the flowsheet testing. The SRAT product from this run retained the higher yield stress of the starting sludge. The run indicated that ultrasonication is an effective tool to increase the yield stress of simulants to targeted values and the chemistry of downstream processing is not impacted. Significant differences were noted in the cycle time extension test compared to the Phase III flowsheet baseline runs. Large decreases in the ammonia and hydrogen generation rates were noted along with reduced mercury stripping efficiency. The latter effect is similar to that of operating under a high acid stoichiometry. It is conceivable that, under the distinctly different conditions of high formic acid concentration (high acid run) or slow formic acid addition (extended run), that mercury could form amalgams with noble metals, possibly rendering both inert. Thus, the removal of free mercury and noble metals could decrease the rate of catalytic formic acid reactions which would decrease generation of ammonium and hydrogen. The potential underlying reasons for the behavior noted during this run would require additional testing.

  13. Magnetically tunable resonance frequency beam utilizing a stress-sensitive film

    DOE Patents [OSTI]

    Davis, J. Kenneth; Thundat, Thomas G.; Wachter, Eric A.

    2001-01-01

    Methods and apparatus for detecting particular frequencies of vibration utilize a magnetically-tunable beam element having a stress-sensitive coating and means for providing magnetic force to controllably deflect the beam element thereby changing its stiffness and its resonance frequency. It is then determined from the response of the magnetically-tunable beam element to the vibration to which the beam is exposed whether or not a particular frequency or frequencies of vibration are detected.

  14. Accelerated Stress Test and Polarization Curve Protocols for PEM Fuel Cells

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

    Appendix A: FCTT AST and Polarization Curve Protocols for PEMFCs U.S. DRIVE Fuel Cell Tech Team Cell Component Accelerated Stress Test and Polarization Curve Protocols for PEM Fuel Cells (Electrocatalysts, Supports, Membranes, and Membrane Electrode Assemblies) Last Revision: January 14, 2013 Fuel cells, especially for automotive propulsion, must operate over a wide range of operating and cyclic conditions. The desired operating range encompasses temperatures from below the freezing point to

  15. Distinctive Oxidative Stress Responses to Hydrogen Peroxide in Sulfate Reducing Bacteria Desulfovibrio vulgaris Hildenborough

    SciTech Connect (OSTI)

    Zhou, Aifen; He, Zhili; Redding, A.M.; Mukhopadhyay, Aindrila; Hemme, Christopher L.; Joachimiak, Marcin P.; Bender, Kelly S.; Keasling, Jay D.; Stahl, David A.; Fields, Matthew W.; Hazen, Terry C.; Arkin, Adam P.; Wall, Judy D.; Zhou, Jizhong

    2009-01-01

    Response of Desulfovibrio vulgaris Hildenborough to hydrogen peroxide (H2O2, 1 mM) was investigated with transcriptomic, proteomic and genetic approaches. Microarray data demonstrated that gene expression was extensively affected by H2O2 with the response peaking at 120 min after H2O2 treatment. Genes affected include those involved with energy production, sulfate reduction, ribosomal structure and translation, H2O2 scavenging, posttranslational modification and DNA repair as evidenced by gene coexpression networks generated via a random matrix-theory based approach. Data from this study support the hypothesis that both PerR and Fur play important roles in H2O2-induced oxidative stress response. First, both PerR and Fur regulon genes were significantly up-regulated. Second, predicted PerR regulon genes ahpC and rbr2 were derepressedin Delta PerR and Delta Fur mutants and induction of neither gene was observed in both Delta PerR and Delta Fur when challenged with peroxide, suggesting possible overlap of these regulons. Third, both Delta PerR and Delta Fur appeared to be more tolerant of H2O2 as measured by optical density. Forth, proteomics data suggested de-repression of Fur during the oxidative stress response. In terms of the intracellular enzymatic H2O2 scavenging, gene expression data suggested that Rdl and Rbr2 may play major roles in the detoxification of H2O2. In addition, induction of thioredoxin reductase and thioredoxin appeared to be independent of PerR and Fur. Considering all data together, D. vulgaris employed a distinctive stress resistance mechanism to defend against increased cellular H2O2, and the temporal gene expression changes were consistent with the slowdown of cell growth at the onset of oxidative stress.

  16. Scrambled and fried: Cigarette smoke exposure causes antral follicle destruction and oocyte dysfunction through oxidative stress

    SciTech Connect (OSTI)

    Sobinoff, A.P.; Beckett, E.L.; Jarnicki, A.G.; Sutherland, J.M.; McCluskey, A.; Hansbro, P.M.; McLaughlin, E.A.

    2013-09-01

    Cigarette smoke is a reproductive hazard associated with pre-mature reproductive senescence and reduced clinical pregnancy rates in female smokers. Despite an increased awareness of the adverse effects of cigarette smoke exposure on systemic health, many women remain unaware of the adverse effects of cigarette smoke on female fertility. This issue is compounded by our limited understanding of the molecular mechanisms behind cigarette smoke induced infertility. In this study we used a direct nasal exposure mouse model of cigarette smoke-induced chronic obstructive pulmonary disease to characterise mechanisms of cigarette-smoke induced ovotoxicity. Cigarette smoke exposure caused increased levels of primordial follicle depletion, antral follicle oocyte apoptosis and oxidative stress in exposed ovaries, resulting in fewer follicles available for ovulation. Evidence of oxidative stress also persisted in ovulated oocytes which escaped destruction, with increased levels of mitochondrial ROS and lipid peroxidation resulting in reduced fertilisation potential. Microarray analysis of ovarian tissue correlated these insults with a complex mechanism of ovotoxicity involving genes associated with detoxification, inflammation, follicular activation, immune cell mediated apoptosis and membrane organisation. In particular, the phase I detoxifying enzyme cyp2e1 was found to be significantly up-regulated in developing oocytes; an enzyme known to cause molecular bioactivation resulting in oxidative stress. Our results provide a preliminary model of cigarette smoke induced sub-fertility through cyp2e1 bioactivation and oxidative stress, resulting in developing follicle depletion and oocyte dysfunction. - Highlights: Cigarette smoke exposure targets developing follicle oocytes. The antral follicle oocyte is a primary site of ovarian cigarette smoke metabolism. Cyp2e1 is a major enzyme involved in ameliorating smoke-induced ovotoxicity. Cigarette smoke causes oocyte

  17. Heat treatment of NiCrFe alloy 600 to optimize resistance to intergranular stress corrosion

    DOE Patents [OSTI]

    Steeves, A.F.; Bibb, A.E.

    A process of producing a NiCrFe alloy having a high resistance to stress corrosion cracking comprises heating a NiCrFe alloy to a temperature sufficient to enable the carbon present in the alloy body in the form of carbide deposits to enter into solution, rapidly cooling the alloy body, and heating the cooled body to a temperature between 1100 to 1500/sup 0/F for about 1 to 30 hours.

  18. Heat treatment of NiCrFe alloy to optimize resistance to intergrannular stress corrosion

    DOE Patents [OSTI]

    Steeves, Arthur F.; Bibb, Albert E.

    1984-01-01

    A process of producing a NiCrFe alloy having a high resistance to stress corrosion cracking comprising heating a NiCrFe alloy to a temperature sufficient to enable the carbon present in the alloy body in the form of carbide deposits to enter into solution, rapidly cool the alloy body, and heat the cooled body to a temperature between 1100.degree. to 1500.degree. F. for about 1 to 30 hours.

  19. The Role of Geochemistry and Stress on Fracture Development and Proppant

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

    Behavior in EGS Reservoirs; 2010 Geothermal Technology Program Peer Review Report | Department of Energy Reservoirs; 2010 Geothermal Technology Program Peer Review Report The Role of Geochemistry and Stress on Fracture Development and Proppant Behavior in EGS Reservoirs; 2010 Geothermal Technology Program Peer Review Report DOE 2010 Geothermal Technologies Program Peer Review reservoir_032_moore.pdf (208.8 KB) More Documents & Publications Use of Geophysical Techniques to Characterize

  20. Electrostatically tunable resonance frequency beam utilizing a stress-sensitive film

    DOE Patents [OSTI]

    Thundat, Thomas G.; Wachter, Eric A.; Davis, J. Kenneth

    2001-01-01

    Methods and apparatus for detecting particular frequencies of acoustic vibration utilize an electrostatically-tunable beam element having a stress-sensitive coating and means for providing electrostatic force to controllably deflect the beam element thereby changing its stiffness and its resonance frequency. It is then determined from the response of the electrostatically-tunable beam element to the acoustical vibration to which the beam is exposed whether or not a particular frequency or frequencies of acoustic vibration are detected.

  1. Stress-dependent grain size evolution of nanocrystalline Ni-W and its impact on friction behavior

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Argibay, N.; Furnish, T. A.; Boyce, B. L.; Clark, B. G.; Chandross, M.

    2016-06-07

    The friction behavior of ultra-nanocrystalline Ni-W coatings was investigated. A critical stress threshold was identified below which friction remained low, and above which a time-dependent evolution toward higher friction behavior occurred. Founded on established plasticity models we propose a correlation between surface grain size and applied stress that can be used to predict the critical stress separating the two friction regimes. Lastly, this interpretation of plasticity models suggests that macro-scale low and high friction regimes are respectively associated with the nano-scale mechanisms of grain boundary and dislocation-mediated plasticity.

  2. Stress-corrosion cracking and surface-pitting tests of NiCrFe alloy bolts (LWBR development program)

    SciTech Connect (OSTI)

    Keller, K.L.

    1983-02-01

    Accelerated corrosion tests confirmed the adequate resistance to stress corrosion cracking (SCC) of the specific heats of NiCrFe X-750 and NiCrFe 600 used as bolts in the LWBR. SCC acceleration was achieved by running autoclave corrosion tests at 680/sup 0/F (well above the LWBR core operating temperatures of approximately 525/sup 0/F to 560/sup 0/F). Component stress levels were representative of maximum service stresses. No specimens from heats of either alloy suffered SCC.

  3. Effects of fluid shear stress on polyelectrolyte multilayers by neutron scattering studies

    SciTech Connect (OSTI)

    Singh, Saurabh; Junghans, Ann; Watkins, Erik; Kapoor, Yash; Toomey, Ryan; Majewski, Jaroslaw

    2015-02-17

    The structure of layer-by-layer (LbL) deposited nanofilm coatings consists of alternating polyethylenimine (PEI) and polystyrenesulfonate (PSS) films deposited on a single crystal quartz substrate. LbL-deposited nanofilms were investigated by neutron reflectomery (NR) in contact with water in the static and fluid shear stress conditions. The fluid shear stress was applied through a laminar flow of the liquid parallel to the quartz/polymer interface in a custom-built solid–liquid interface cell. The scattering length density profiles obtained from NR results of these polyelectrolyte multilayers (PEM), measured under different shear conditions, showed proportional decrease of volume fraction of water hydrating the polymers. For the highest shear rate applied (ca. 6800 s–1) the water volume fraction decreased by approximately 7%. The decrease of the volume fraction of water was homogeneous through the thickness of the film. Since there were not any significant changes in the total polymer thickness, it resulted in negative osmotic pressures in the film. The PEM films were compared with the behavior of thin films of thermoresponsive poly(N-isopropylacrylamide) (pNIPAM) deposited via spin-coating. The PEM and pNIPAM differ in their interactions with water molecules, and they showed opposite behaviors under the fluid shear stress. In both cases the polymer hydration was reversible upon the restoration of static conditions. Furthermore, a theoretical explanation is given to explain this difference in the effect of shear on hydration of polymeric thin films.

  4. Beyond Adapting to Climate Change: Embedding Adaptation in Responses to Multiple Threats and Stresses

    SciTech Connect (OSTI)

    Wilbanks, Thomas J; Kates, Dr. Robert W.

    2010-01-01

    Climate change impacts are already being experienced in every region of the United States and every part of the world most severely in Arctic regions and adaptation is needed now. Although climate change adaptation research is still in its infancy, significant adaptation planning in the United States has already begun in a number of localities. This article seeks to broaden the adaptation effort by integrating it with broader frameworks of hazards research, sustainability science, and community and regional resilience. To extend the range of experience, we draw from ongoing case studies in the Southeastern United States and the environmental history of New Orleans to consider the multiple threats and stresses that all communities and regions experience. Embedding climate adaptation in responses to multiple threats and stresses helps us to understand climate change impacts, themselves often products of multiple stresses, to achieve community acceptance of needed adaptations as co-benefits of addressing multiple threats, and to mainstream the process of climate adaptation through the larger envelope of social relationships, communication channels, and broad-based awareness of needs for risk management that accompany community resilience.

  5. Soil erosion rates caused by wind and saltating sand stresses in a wind tunnel

    SciTech Connect (OSTI)

    Ligotke, M.W.

    1993-02-01

    Wind erosion tests were performed in a wind tunnel in support of the development of long-term protective barriers to cap stabilized waste sites at the Hanford Site. Controlled wind and saltating sand erosive stresses were applied to physical models of barrier surface layers to simulate worst-case eolian erosive stresses. The goal of these tests was to provide information useful to the design and evaluation of the surface layer composition of an arid-region waste site barrier concept that incorporates a deep fine-soil reservoir. A surface layer composition is needed that will form an armor resistant to eolian erosion during periods of extreme dry climatic conditions, especially when such conditions result in the elimination or reduction of vegetation by water deprivation or wildfire. Because of the life span required of Hanford waste barriers, it is important that additional work follow these wind tunnel studies. A modeling effort is planned to aid the interpretation of test results with respect to the suitability of pea gravel to protect the finite-soil reservoir during long periods of climatic stress. It is additionally recommended that wind tunnel tests be continued and field data be obtained at prototype or actual barrier sites. Results wig contribute to barrier design efforts and provide confidence in the design of long-term waste site caps for and regions.

  6. Stress-induced piezoelectric field in GaN-based 450-nm light-emitting diodes

    SciTech Connect (OSTI)

    Tawfik, Wael Z.; Hyeon, Gil Yong; Lee, June Key

    2014-10-28

    We investigated the influence of the built-in piezoelectric field induced by compressive stress on the characteristics of GaN-based 450-nm light-emitting diodes (LEDs) prepared on sapphire substrates of different thicknesses. As the sapphire substrate thickness was reduced, the compressive stress in the GaN layer was released, resulting in wafer bowing. The wafer bowing-induced mechanical stress altered the piezoelectric field, which in turn reduced the quantum confined Stark effect in the InGaN/GaN active region of the LED. The flat-band voltage was estimated by measuring the applied bias voltage that induced a 180° phase shift in the electro-reflectance (ER) spectrum. The piezoelectric field estimated by the ER spectra changed by ∼110 kV/cm. The electroluminescence spectral peak wavelength was blue-shifted, and the internal quantum efficiency was improved by about 22% at a high injection current of 100 mA. The LED on the 60-μm-thick sapphire substrate exhibited the highest light output power of ∼59 mW at an injection current of 100 mA, with the operating voltage unchanged.

  7. Development of adherent ceramic coatings to reduce contact stress damage of ceramics

    SciTech Connect (OSTI)

    Wayne, S.F.; Selverian, J.H.; O'Neil, D. )

    1992-11-01

    Strongly adherent coatings were deposited on reaction bonded Si[sub 3]N[sub 4] (RBSN), sintered SiC (SSC), and HIP'ed Si[sub 3]N[sub 4] (HSN) and using a newly developed chemical vapor deposition (CVD) process. Performance of the coating was assessed by oxidation, strength and contact stress testing. A new method was developed to experimentally determine the strength and Weibull modulus of thin brittle films on ceramic substrates. A significant portion of the study was devoted to numerical modeling of the coatings in order to understand the contributions of residual stress as different coating materials and thicknesses were combined. Coating designs were further analyzed by simulating the crack growth behavior in multilayer films while accounting for the interface fracture mechanics. This work has shown that the Al[sub 2]0[sub 3+]ZrO[sub 2] composite coating developed in this program can provide resistance to oxidation and contact stress. Commercial application of the composite coating has been successfully demonstrated by useof the Al[sub 2]0[sub 3+]ZrO[sub 2] composite as a protective coating on a Si[sub 3]N[sub 4] cutting tool.

  8. Measurements of stress fields near a grain boundary: Exploring blocked arrays of dislocations in 3D

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Guo, Y.; Collins, D. M.; Tarleton, E.; Hofmann, F.; Tischler, J.; Liu, W.; Xu, R.; Wilkinson, A. J.; Britton, T. B.

    2015-06-24

    The interaction between dislocation pile-ups and grain boundaries gives rise to heterogeneous stress distributions when a structural metal is subjected to mechanical loading. Such stress heterogeneity leads to preferential sites for damage nucleation and therefore is intrinsically linked to the strength and ductility of polycrystalline metals. To date the majority of conclusions have been drawn from 2D experimental investigations at the sample surface, allowing only incomplete observations. Our purpose here is to significantly advance the understanding of such problems by providing quantitative measurements of the effects of dislocation pile up and grain boundary interactions in 3D. This is accomplished throughmore » the application of differential aperture X-ray Laue micro-diffraction (DAXM) and high angular resolution electron backscatter diffraction (HR-EBSD) techniques. Our analysis demonstrates a similar strain characterization capability between DAXM and HR-EBSD and the variation of stress intensity in 3D reveals that different parts of the same grain boundary may have different strengths in resisting slip transfer, likely due to the local grain boundary curvature.« less

  9. Preliminary Analysis of Stress in the Newberry EGS Well NWG 55-29

    SciTech Connect (OSTI)

    Nicholas C. Davatzes, Stephen H. Hickman

    2011-10-23

    As part of the planning for stimulation of the Newberry Volcano Enhanced Geothermal Systems (EGS) Demonstration project in Oregon, a high-resolution borehole televiewer (BHTV) log was acquired using the ALT ABI85 BHTV tool in the slightly deviated NWG 55-29 well. The image log reveals an extensive network of fractures in a conjugate set striking approximately N-S and dipping 50° that are well oriented for normal slip and are consistent with surface-breaking regional normal faults in the vicinity. Similarly, breakouts indicate a consistent minimum horizontal stress, Shmin, azimuth of 092.3±17.3°. In conjunction with a suite of geophysical logs, a model of the stress magnitudes constrained by the width of breakouts at depth and a model of rock strength independently indicates a predominantly normal faulting stress regime.

  10. Microearthquake Study of the Salton Sea Geothermal Field, California: Evidence of Stress Triggering - Masters Thesis

    SciTech Connect (OSTI)

    Holland, Austin Adams

    2002-02-01

    A digital network of 24 seismograph stations was operated from September 15, 1987 to September 30, 1988, by Lawrence Livermore National Laboratory and Unocal as part of the Salton Sea Scientific Drilling Project to study seismicity related to tectonics and geothermal activity near the drilling site. More than 2001 microearthquakes were relocated in this study in order to image any pervasive structures that may exist within the Salton Sea geothermal field. First, detailed velocity models were obtained through standard 1-D inversion techniques. These velocity models were then used to relocate events using both single event methods and Double-Differencing, a joint hypocenter location method. An anisotropic velocity model was built from anisotropy estimates obtained from well logs within the study area. During the study period, the Superstition wills sequence occurred with two moderate earthquakes of MS 6.2 and MS 6.6. These moderate earthquakes caused a rotation of the stress field as observed from the inversion of first motion data from microearthquakes at the Salton Sea geothermal field. Coulomb failure analysis also indicates that microearthquakes occurring after the Superstition Hills sequence are located within a region of stress increase suggesting stress triggering caused by the moderate earthquakes.

  11. STRESS AND FAILURE ANALYSIS OF RAPIDLY ROTATING ASTEROID (29075) 1950DA

    SciTech Connect (OSTI)

    Hirabayashi, Masatoshi; Scheeres, Daniel J.

    2015-01-01

    Rozitis et al. recently reported that near-Earth asteroid (29075) 1950DA, whose bulk density ranges from 1.0 g cm{sup 3} to 2.4g cm{sup 3}, is a rubble pile and requires a cohesive strength of at least 44-76 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 1950DA. 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 1950DA 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 75-85 Pa. It suggests that for the failure mode of this body, the internal core first fails structurally, followed by the surface region. This implies that if cohesion is constant over the whole volume, the equatorial ridge of 1950DA results from a material flow going outward along the equatorial plane in the internal core, but not from a landslide as has been hypothesized. This has additional implications for the likely density of the interior of the body.

  12. Interfacial stress balances in structured continua and free surface flows in ferrofluids

    SciTech Connect (OSTI)

    Chaves, Arlex; Rinaldi, Carlos

    2014-04-15

    Interfacial linear and internal angular momentum balances are obtained for a structured continuum and for the special case of a ferrofluid, a suspension of magnetic nanoparticles in a Newtonian fluid. The interfacial balance equations account for the effects of surface tension and surface tension gradient, magnetic surface excess forces, antisymmetric stresses, and couple stresses in driving interfacial flows in ferrofluids. Application of the interfacial balance equations is illustrated by obtaining analytical expressions for the translational and spin velocity profiles in a thin film of ferrofluid on an infinite flat plate when a rotating magnetic field is applied with axis of rotation parallel to the ferrofluid/air interface. The cases of zero and non-zero spin viscosity are considered for small applied magnetic field amplitude. Expressions for the maximum translational velocity, slope of the translational velocity profile at the ferrofluid/air interface, and volumetric flow rate are obtained and their use to test the relevance of spin viscosity and couple stresses in the flow situation under consideration is discussed.

  13. Primary water stress corrosion cracking of Alloy 600: Effects of processing parameters

    SciTech Connect (OSTI)

    Seman, D.J.; Webb, G.L.; Parrington, R.J.

    1993-10-22

    Correlations of stress corrosion cracking (SCC) data in deaerated water with temperature, stress, metallography, and processing for laboratory test specimens are presented. Initiation time data show that a low temperature anneal and resulting absence of grain boundary carbides result in a material having increased susceptibility to SCC. Data also show that hot worked and annealed Alloy 600 is more resistant than cold worked and annealed material, both having carbide decorated grain boundaries. In absence of grain boundary carbides, both materials are equally susceptible. Low temperature thermal treatment (1100F) reduces SCC susceptibility with or without grain boundary decoration. Weld metal data and data correlations developed from 700 double U-bends are presented. Data demonstrate the effect of increased carbon content to improve SCC resistance. The data shows that the general relation of time, temperature and strain for wrought material is followed for the weld metal. The weld process used did not affect the SCC susceptibility of EN-82 which showed a greater resistance to SCC than EN-62. Stress relief of weld deposits showed an improvement for wrought material. Heat affected zone resistance was improved if the starting material received a high temperature anneal (1850 to 2000F). Range of SCC initiation times for weld metal is comparable to the range of initiation times for wrought material.

  14. Lead-induced stress corrosion cracking of Alloy 600 and 690 in high temperature water

    SciTech Connect (OSTI)

    Sakai, T.; Senjuh, T.; Aoki, K.; Shigemitsu, T.; Kishi, Y.

    1992-12-31

    Lead is one of the potential contributing impurities to the degradation of PWR steam generator tubing. Recent laboratory testing has shown that lead is a corrosive material for Alloy 600 steam generator tubing. However, it is still unknown how lead influences the corrosion of steam generator tubing, including the effect of lead concentration, solution pH, stress level and material characteristics. In this study, two kinds of experiments were performed. One was to investigate the thin film characteristic and selectively dissolved base metal elements of Alloy 600MA in high temperature solutions of different lead concentrations and pH. The other investigated the dependency of degradation of Alloy 600MA and Alloy 690TT on lead concentration and stress level in mild acidic environment, at 340{degrees}C for 2500 hrs. It was firstly demonstrated that lead-enhanced selective dissolution of nickel from alloy base metal, as a result of electrochemical reaction between lead and nickel, might cause the initiation and propagation of corrosion. Secondly, we showed that Alloy 690TT, generally very corrosion resistant material, also suffered from Pb-induced corrosion. The difference of the lead-induced stress corrosion morphology of Alloy 600MA and Alloy 690TT was also clarified.

  15. Surface and grain boundary segregation, stress corrosion cracking, and corrosion fatigue of Inconel 600

    SciTech Connect (OSTI)

    Smialowska, S.; Cragnolino, G.; Macdonald, D.D.

    1985-03-01

    The stress corrosion cracking of Inconel 600 in environments related to nuclear power systems was studied in relation to the role of segregation in the alloy. Auger electron spectroscopy was used to evaluate the surface segregation of different impurities in Inconel 600 as a function of heat-to-heat variation and heat treatment. The degree of segregation of various elements (S, P, N, Ti, Si, and C) on the fracture surface of nickel was also evaluated as a function of the heat treatment employed, temperature, and cooling rate. The effects of alloying elements, added to nickel with the aim of reducing sulfur segregation to grain boundaries, was also studied. The susceptibility of nickel to intergranular corrosion in acidic and alkaline solutions at different potentials was measured as a function of sulfur segregation to the grain boundaries. The effect of heat treatment and applied potential on the caustic stress corrosion cracking susceptibiliy of Inconel 600 was studied in concentrated NaOH solutions at 140/sup 0/C using the slow strain rate technique. The corrosion fatigue resistance of Inconel Alloy 600 in concentrated NaOH solutions at 140/sup 0/C was evaluated as a function of heat treatment conditions using smooth bar specimens. The results have shown that the stress corrosion behavior of Inconel 600 in caustic solutions differs greatly from that in acidic and nearly neutral environments. Furthermore, sensitization by heat treatment was found to be beneficial under caustic corrosion conditions but detrimental in acidic environments.

  16. Stress-intensity-factor influence coefficients for semielliptical inner-surface flaws in clad pressure vessels

    SciTech Connect (OSTI)

    Keeney, J.A.; Bryson, J.W.

    1995-12-31

    A problem of particular interest in pressure vessel technology is the calculation of accurate stress-intensity factors for semielliptical surface cracks in cylinders. Computing costs for direct solution techniques can be prohibitive when applied to three-dimensional (3-D) geometries with time-varying boundary conditions such as those associated with pressurized thermal shock. An alternative superposition technique requires the calculation of a set of influence coefficients for a given 3-D crack model that can be superimposed to obtain mode-I stress-intensity factors. This paper presents stress-intensity-factor influence coefficients (SIFICs) for axially and circumferentially oriented finite-length semielliptical inner-surface flaws with aspect ratios (total crack length (2c) to crack depth (a)) of 2, 6, and 10 for clad cylinders having an internal radius to wall thickness (t) ratio of 10. SIFICs are computed for flaw depths in the range of 0.01 {le} a/t {le} 0.5 and two cladding thicknesses. The incorporate of this SIFIC data base in fracture mechanics codes will facilitate the generation of fracture mechanics solutions for a wide range of flaw geometries as may be required in structural integrity assessments of pressurized-water and boiling-water reactors.

  17. Chlorobenzene induces oxidative stress in human lung epithelial cells in vitro

    SciTech Connect (OSTI)

    Feltens, Ralph; Moegel, Iljana; Roeder-Stolinski, Carmen; Simon, Jan-Christoph; Herberth, Gunda; Lehmann, Irina

    2010-01-01

    Chlorobenzene is a volatile organic compound (VOC) that is widely used as a solvent, degreasing agent and chemical intermediate in many industrial settings. Occupational studies have shown that acute and chronic exposure to chlorobenzene can cause irritation of the mucosa of the upper respiratory tract and eyes. Using in vitro assays, we have shown in a previous study that human bronchial epithelial cells release inflammatory mediators such as the cytokine monocyte chemoattractant protein-1 (MCP-1) in response to chlorobenzene. This response is mediated through the NF-kappaB signaling pathway. Here, we investigated the effects of monochlorobenzene on human lung cells, with emphasis on potential alterations of the redox equilibrium to clarify whether the chlorobenzene-induced inflammatory response in lung epithelial cells is caused via an oxidative stress-dependent mechanism. We found that expression of cellular markers for oxidative stress, such as heme oxygenase 1 (HO-1), glutathione S-transferase pi1 (GSTP1), superoxide dismutase 1 (SOD1), prostaglandin-endoperoxide synthase 2 (PTGS2) and dual specificity phosphatase 1 (DUSP1), were elevated in the presence of monochlorobenzene. Likewise, intracellular reactive oxygen species (ROS) were increased in response to exposure. However, in the presence of the antioxidants N-(2-mercaptopropionyl)-glycine (MPG) or bucillamine, chlorobenzene-induced upregulation of marker proteins and release of the inflammatory mediator MCP-1 are suppressed. These results complement our previous findings and point to an oxidative stress-mediated inflammatory response following chlorobenzene exposure.

  18. Nonlinear ultrasonic assessment of stress corrosion cracking damage in sensitized 304 stainless steel

    SciTech Connect (OSTI)

    Morlock, Florian Jacobs, Laurence J. Kim, Jin-Yeon; Singh, Preet; Wall, James J.

    2015-03-31

    This research uses nonlinear Rayleigh surface waves to characterize stress corrosion cracking (SCC) damage in welded 304 Stainless Steel (304 SS). 304 SS is widely used in reactor pressure vessels, where a corrosive environment in combination with applied stress due to high internal pressures can cause SCC. Welds and the nearby heat affected zones (HAZ) in the vessel material are especially sensitive to SCC damage. SCC damage results in microstructural changes such as dislocation formation and microcrack initiation that in the long term lead to reduced structural integrity and material failure. Therefore, the early detection of SCC is crucial to ensure safe operation. It has been shown that the microstructural changes caused by SCC can generate higher harmonic waves when excited harmonically. This research considers different levels of SCC damage induced in samples of welded 304 SS by applying stress to a specimen held in a corrosive medium (Sodium Thiosulfate). A nonlinear Rayleigh surface wave is introduced in the material and the fundamental and the second harmonic waves are measured using wedge detection. The nonlinearity parameter that relates the fundamental and the second harmonic amplitudes, is computed to quantify the SCC damage in each sample. These results are used to demonstrate the feasibility of using nonlinear Rayleigh waves to characterize SCC damage.

  19. Oxidative stress induced lipid accumulation via SREBP1c activation in HepG2 cells

    SciTech Connect (OSTI)

    Sekiya, Mika; Hiraishi, Ako; Touyama, Maiko [Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8572 (Japan); Sakamoto, Kazuichi [Graduate School of Life and Environmental Sciences, University of Tsukuba, 1-1-1 Tennoudai, Tsukuba, Ibaraki 305-8572 (Japan)], E-mail: sakamoto@biol.tsukuba.ac.jp

    2008-10-31

    SREBP1c (sterol regulatory element-binding protein 1c) is a metabolic-syndrome-associated transcription factor that controls fatty acid biosynthesis under glucose/insulin stimulation. Oxidative stress increases lipid accumulation, which promotes the generation of reactive oxygen species (ROS). However, we know little about the role of oxidative stress in fatty acid biosynthesis. To clarify the action of oxidative stress in lipid accumulation via SREBP1c, we examined SREBP1c activity in H{sub 2}O{sub 2}-treated mammalian cells. We introduced a luciferase reporter plasmid carrying the SREBP1c-binding site into HepG2 or COS-7 cells. With increasing H{sub 2}O{sub 2} dose, SREBP1c transcriptional activity increased in HepG2 cells but declined in COS-7 cells. RT-PCR analysis revealed that mRNA expression of SREBP1c gene or of SREBP1c-regulated genes rose H{sub 2}O{sub 2} dose-dependently in HepG2 cells but dropped in COS-7 cells. Lipid accumulation and levels of the nuclear form of SREBP1c increased in H{sub 2}O{sub 2}-stimulated HepG2 cells. ROS may stimulate lipid accumulation in HepG2 cells via SREBP1c activation.

  20. 3-D description of fracture surfaces and stress-sensitivity analysis for naturally fractured reservoirs

    SciTech Connect (OSTI)

    Zhang, S.Q.; Jioa, D.; Meng, Y.F.; Fan, Y.

    1997-08-01

    Three kinds of reservoir cores (limestone, sandstone, and shale with natural fractures) were used to study the effect of morphology of fracture surfaces on stress sensitivity. The cores, obtained from the reservoirs with depths of 2170 to 2300 m, have fractures which are mated on a large scale, but unmated on a fine scale. A specially designed photoelectric scanner with a computer was used to describe the topography of the fracture surfaces. Then, theoretical analysis of the fracture closure was carried out based on the fracture topography generated. The scanning results show that the asperity has almost normal distributions for all three types of samples. For the tested samples, the fracture closure predicted by the elastic-contact theory is different from the laboratory measurements because plastic deformation of the aspirates plays an important role under the testing range of normal stresses. In this work, the traditionally used elastic-contact theory has been modified to better predict the stress sensitivity of reservoir fractures. Analysis shows that the standard deviation of the probability density function of asperity distribution has a great effect on the fracture closure rate.

  1. Trichodermin induces cell apoptosis through mitochondrial dysfunction and endoplasmic reticulum stress in human chondrosarcoma cells

    SciTech Connect (OSTI)

    Su, Chen-Ming; Wang, Shih-Wei; Lee, Tzong-Huei; Tzeng, Wen-Pei; Hsiao, Che-Jen; Liu, Shih-Chia; Tang, Chih-Hsin

    2013-10-15

    Chondrosarcoma is the second most common primary bone tumor, and it responds poorly to both chemotherapy and radiation treatment. Nalanthamala psidii was described originally as Myxosporium in 1926. This is the first study to investigate the anti-tumor activity of trichodermin (trichothec-9-en-4-ol, 12,13-epoxy-, acetate), an endophytic fungal metabolite from N. psidii against human chondrosarcoma cells. We demonstrated that trichodermin induced cell apoptosis in human chondrosarcoma cell lines (JJ012 and SW1353 cells) instead of primary chondrocytes. In addition, trichodermin triggered endoplasmic reticulum (ER) stress protein levels of IRE1, p-PERK, GRP78, and GRP94, which were characterized by changes in cytosolic calcium levels. Furthermore, trichodermin induced the upregulation of Bax and Bid, the downregulation of Bcl-2, and the dysfunction of mitochondria, which released cytochrome c and activated caspase-3 in human chondrosarcoma. In addition, animal experiments illustrated reduced tumor volume, which led to an increased number of terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL)-positive cells and an increased level of cleaved PARP protein following trichodermin treatment. Together, this study demonstrates that trichodermin is a novel anti-tumor agent against human chondrosarcoma cells both in vitro and in vivo via mitochondrial dysfunction and ER stress. - Highlights: Trichodermin induces chondrosarcoma apoptosis. ER stress is involved in trichodermin-induced cell death. Trichodermin induces chondrosarcoma death in vivo.

  2. Plant salt stress status is transmitted systemically via propagating calcium waves

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Stephan, Aaron B.; Schroeder, Julian I.

    2014-04-29

    The existence and relevance of rapid long distance signaling in plants is evident to any observer of the nastic movements of the Venus flytrap (Dionaea muscipula) or the sensitive plant (Mimosa pudica). However, all plants require the transmission of sensory information from the site of perception to other tissues to adjust their physiological states according to their environment. It is becoming increasingly apparent that rapid long-distance signals exist throughout the plant kingdom and may be responsible for initiating a multitude of physiological responses: electrical “action potentials” have been shown to convey wounding and saltstress information from leaf-to-leaf (1, 2); amore » “hydraulic signal” transmitted by the direction of water movement within the xylem can mediate long-distance signaling of water stress experienced by the roots to the leaves in Arabidopsis (3); and reactive oxygen species (ROS) have been shown to propagate across a plant and carry stimulus-specific information to a variety of stresses (4). In PNAS, Choi et al. (5) use elegant approaches and present advances demonstrating that calcium can function as a long-distance signaling messenger, propagating in waves from roots and carrying salt-stress signals to induce expression of salt tolerance genes in leaves.« less

  3. ADDITIONAL STRESS AND FRACTURE MECHANICS ANALYSES OF PRESSURIZED WATER REACTOR PRESSURE VESSEL NOZZLES

    SciTech Connect (OSTI)

    Walter, Matthew; Yin, Shengjun; Stevens, Gary; Sommerville, Daniel; Palm, Nathan; Heinecke, Carol

    2012-01-01

    In past years, the authors have undertaken various studies of nozzles in both boiling water reactors (BWRs) and pressurized water reactors (PWRs) located in the reactor pressure vessel (RPV) adjacent to the core beltline region. Those studies described stress and fracture mechanics analyses performed to assess various RPV nozzle geometries, which were selected based on their proximity to the core beltline region, i.e., those nozzle configurations that are located close enough to the core region such that they may receive sufficient fluence prior to end-of-life (EOL) to require evaluation of embrittlement as part of the RPV analyses associated with pressure-temperature (P-T) limits. In this paper, additional stress and fracture analyses are summarized that were performed for additional PWR nozzles with the following objectives: To expand the population of PWR nozzle configurations evaluated, which was limited in the previous work to just two nozzles (one inlet and one outlet nozzle). To model and understand differences in stress results obtained for an internal pressure load case using a two-dimensional (2-D) axi-symmetric finite element model (FEM) vs. a three-dimensional (3-D) FEM for these PWR nozzles. In particular, the ovalization (stress concentration) effect of two intersecting cylinders, which is typical of RPV nozzle configurations, was investigated. To investigate the applicability of previously recommended linear elastic fracture mechanics (LEFM) hand solutions for calculating the Mode I stress intensity factor for a postulated nozzle corner crack for pressure loading for these PWR nozzles. These analyses were performed to further expand earlier work completed to support potential revision and refinement of Title 10 to the U.S. Code of Federal Regulations (CFR), Part 50, Appendix G, Fracture Toughness Requirements, and are intended to supplement similar evaluation of nozzles presented at the 2008, 2009, and 2011 Pressure Vessels and Piping (PVP

  4. Cell-specific oxidative stress and cytotoxicity after wildfire coarse particulate matter instillation into mouse lung

    SciTech Connect (OSTI)

    Williams, Keisha M.; Franzi, Lisa M.; Last, Jerold A.

    2013-01-01

    Our previous work has shown that coarse particulate matter (PM{sub 10-2.5}) from wildfire smoke is more toxic to lung macrophages on an equal dose (by mass) basis than coarse PM isolated from normal ambient air, as evidenced by decreased numbers of macrophages in lung lavage fluid 6 and 24 hours after PM instillation into mouse lungs in vivo and by cytotoxicity to a macrophage cell line observed directly in vitro. We hypothesized that pulmonary macrophages from mice instilled with wildfire coarse PM would undergo more cytotoxicity than macrophages from controls, and that there would be an increase in oxidative stress in their lungs. Cytotoxicity was quantified as decreased viable macrophages and increased percentages of dead macrophages in the bronchoalveolar lavage fluid (BALF) of mice instilled with wildfire coarse PM. At 1 hour after PM instillation, we observed both decreased numbers of viable macrophages and increased dead macrophage percentages as compared to controls. An increase in free isoprostanes, an indicator of oxidative stress, from control values of 28.1 3.2 pg/mL to 83.9 12.2 pg/mL was observed a half-hour after PM instillation. By 1 hour after PM instillation, isoprostane values had returned to 30.4 7.6 pg/mL, not significantly different from control concentrations. Lung sections from mice instilled with wildfire coarse PM showed rapid Clara cell responses, with decreased intracellular staining for the Clara cell secretory protein CCSP 1 hour after wildfire PM instillation. In conclusion, very rapid cytotoxicity occurs in pulmonary macrophages and oxidative stress responses are seen 0.51 hour after wildfire coarse PM instillation. These results define early cellular and biochemical events occurring in vivo and support the hypothesis that oxidative stress-mediated macrophage toxicity plays a key role in the initial response of the mouse lung to wildfire PM exposure. -- Highlights: ? We studied very early events (0.51 hour) after giving

  5. Aryl hydrocarbon receptor protects lung adenocarcinoma cells against cigarette sidestream smoke particulates-induced oxidative stress

    SciTech Connect (OSTI)

    Cheng, Ya-Hsin; Huang, Su-Chin; Lin, Chun-Ju; Cheng, Li-Chuan; Li, Lih-Ann

    2012-03-15

    Environmental cigarette smoke has been suggested to promote lung adenocarcinoma progression through aryl hydrocarbon receptor (AhR)-signaled metabolism. However, whether AhR facilitates metabolic activation or detoxification in exposed adenocarcinoma cells remains ambiguous. To address this question, we have modified the expression level of AhR in two human lung adenocarcinoma cell lines and examined their response to an extract of cigarette sidestream smoke particulates (CSSP). We found that overexpression of AhR in the CL1-5 cell line reduced CSSP-induced ROS production and oxidative DNA damage, whereas knockdown of AhR expression increased ROS level in CSSP-exposed H1355 cells. Oxidative stress sensor Nrf2 and its target gene NQO1 were insensitive to AhR expression level and CSSP treatment in human lung adenocarcinoma cells. In contrast, induction of AhR expression concurrently increased mRNA expression of xenobiotic-metabolizing genes CYP1B1, UGT1A8, and UGT1A10 in a ligand-independent manner. It appeared that AhR accelerated xenobiotic clearing and diminished associated oxidative stress by coordinate regulation of a set of phase I and II metabolizing genes. However, the AhR-signaled protection could not shield cells from constant oxidative stress. Prolonged exposure to high concentrations of CSSP induced G0/G1 cell cycle arrest via the p53–p21–Rb1 signaling pathway. Despite no effect on DNA repair rate, AhR facilitated the recovery of cells from growth arrest when CSSP exposure ended. AhR-overexpressing lung adenocarcinoma cells exhibited an increased anchorage-dependent and independent proliferation when recovery from exposure. In summary, our data demonstrated that AhR protected lung adenocarcinoma cells against CSSP-induced oxidative stress and promoted post-exposure clonogenicity. -- Highlights: ► AhR expression level influences cigarette sidestream smoke-induced ROS production. ► AhR reduces oxidative stress by coordinate regulation of

  6. Laboratory evaluation of mechanical properties of rock using an automated triaxial compression test with a constant mean stress criterion

    SciTech Connect (OSTI)

    Mellegard, K.D.; Pfeifle, T.W.

    1999-07-01

    A computerized, servohydraulic test system has been used in the laboratory to perform axisymmetric, triaxial compression tests on natural rock salt using a load path that maintains constant mean stress. The constant mean stress test protocol illustrates that modern test systems allow a nonstandard load path which can focus on a particular aspect of rock characterization; namely, the onset of dilation. Included are discussions of how the constant mean stress test could be used to investigate material anisotropy and determine elastic moduli. The results from the constant mean stress tests are compared to test results from a traditional test method. The paper also addresses system calibration concerns and the effects of pressure changes on the direct-contact extensometers used to measure strain.

  7. Environment-induced embrittlement: effects of impurity segregation and state of stress. Final report, July 1, 1981-November 30, 1985

    SciTech Connect (OSTI)

    Heldt, L.A.; Hintz, M.B.; Koss, D.A.

    1986-01-01

    Studied were: embrittlement of Monel 400 by hydrogen and liquid metals, intergranular sulfur in nickel, stress corrosion in Cu-Zn alloys, and hydrogen embrittlement of Zircaloy 2, Ni, and carbon steels. (DLC)

  8. Irradiation-Assisted Stress Corrosion Cracking of Austenitic Stainless Steels and Alloy 690 from Halden Phase-II Irradiations

    SciTech Connect (OSTI)

    Chen, Y.; Chopra, O. K.; Soppet, W. K.; Dietz Rago, Nancy L.; Shack, W. J.

    2008-09-01

    This work is an ongoing effort at Argonne National Laboratory on the mechanistic study of irradiation-assisted stress corrosion cracking (IASCC) in the core internals of light water reactors.

  9. Chemical chaperones reduce ionizing radiation-induced endoplasmic reticulum stress and cell death in IEC-6 cells

    SciTech Connect (OSTI)

    Lee, Eun Sang; Lee, Hae-June; Lee, Yoon-Jin; Jeong, Jae-Hoon; Kang, Seongman; Lim, Young-Bin

    2014-07-25

    Highlights: UPR activation precedes caspase activation in irradiated IEC-6 cells. Chemical ER stress inducers radiosensitize IEC-6 cells. siRNAs that targeted ER stress responses ameliorate IR-induced cell death. Chemical chaperons prevent cell death in irradiated IEC-6 cells. - Abstract: Radiotherapy, which is one of the most effective approaches to the treatment of various cancers, plays an important role in malignant cell eradication in the pelvic area and abdomen. However, it also generates some degree of intestinal injury. Apoptosis in the intestinal epithelium is the primary pathological factor that initiates radiation-induced intestinal injury, but the mechanism by which ionizing radiation (IR) induces apoptosis in the intestinal epithelium is not clearly understood. Recently, IR has been shown to induce endoplasmic reticulum (ER) stress, thereby activating the unfolded protein response (UPR) signaling pathway in intestinal epithelial cells. However, the consequences of the IR-induced activation of the UPR signaling pathway on radiosensitivity in intestinal epithelial cells remain to be determined. In this study, we investigated the role of ER stress responses in IR-induced intestinal epithelial cell death. We show that chemical ER stress inducers, such as tunicamycin or thapsigargin, enhanced IR-induced caspase 3 activation and DNA fragmentation in intestinal epithelial cells. Knockdown of Xbp1 or Atf6 with small interfering RNA inhibited IR-induced caspase 3 activation. Treatment with chemical chaperones prevented ER stress and subsequent apoptosis in IR-exposed intestinal epithelial cells. Our results suggest a pro-apoptotic role of ER stress in IR-exposed intestinal epithelial cells. Furthermore, inhibiting ER stress may be an effective strategy to prevent IR-induced intestinal injury.

  10. Stress transfer during different deformation stages in a nano-precipitate-strenthened Ni-Ti shape memory alloy

    SciTech Connect (OSTI)

    Dong, Y. H.; Cong, D. Y.; Nie, Z. H.; He, Z. B.; Wang, Z. L.; Ren, Yang; Wang, Y. D.; Li, L. F.

    2015-11-16

    Understanding the role of fine coherent precipitates in the micromechanical behavior of precipitate-strengthened shape memory alloys (SMAs), which still remains a mystery heretofore, is of crucial importance to the design of advanced SMAs with optimal functional and mechanical properties. Here, we investigate the lattice strain evolution of, and the stress partition between the nanoscale Ni4Ti3 precipitates and the matrix in a precipitate-strengthened Ni-Ti SMA during different deformation stages by in-situ synchrotron high-energy X-ray diffraction technique. We found that, during R-phase reorientation and stress-induced martensitic transformation, which both involve the shear deformation process, the lattice strain of the nanoscale precipitates drastically increases by a magnitude of 0.5%, which corresponds to an abrupt increase of ~520 MPa in internal stress. This indicates that stress repartition occurs and most of the stress is transferred to the precipitates during the shear deformation of the matrix. Lastly, it is further revealed that the nanoscale precipitates which only have a low volume fraction bear a considerable amount of applied stress during all deformation stages investigated, implying that the nanoscale precipitates play an important role in the deformation behavior of the precipitate-strengthened Ni-Ti SMAs.

  11. High-throughput characterization of stresses in thin film materials libraries using Si cantilever array wafers and digital holographic microscopy

    SciTech Connect (OSTI)

    Lai, Y. W.; Ludwig, A.; Hamann, S.; Ehmann, M.

    2011-06-15

    We report the development of an advanced high-throughput stress characterization method for thin film materials libraries sputter-deposited on micro-machined cantilever arrays consisting of around 1500 cantilevers on 4-inch silicon-on-insulator wafers. A low-cost custom-designed digital holographic microscope (DHM) is employed to simultaneously monitor the thin film thickness, the surface topography and the curvature of each of the cantilevers before and after deposition. The variation in stress state across the thin film materials library is then calculated by Stoney's equation based on the obtained radii of curvature of the cantilevers and film thicknesses. DHM with nanometer-scale out-of-plane resolution allows stress measurements in a wide range, at least from several MPa to several GPa. By using an automatic x-y translation stage, the local stresses within a 4-inch materials library are mapped with high accuracy within 10 min. The speed of measurement is greatly improved compared with the prior laser scanning approach that needs more than an hour of measuring time. A high-throughput stress measurement of an as-deposited Fe-Pd-W materials library was evaluated for demonstration. The fast characterization method is expected to accelerate the development of (functional) thin films, e.g., (magnetic) shape memory materials, whose functionality is greatly stress dependent.

  12. Stress transfer during different deformation stages in a nano-precipitate-strenthened Ni-Ti shape memory alloy

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Dong, Y. H.; Cong, D. Y.; Nie, Z. H.; He, Z. B.; Wang, Z. L.; Ren, Yang; Wang, Y. D.; Li, L. F.

    2015-11-16

    Understanding the role of fine coherent precipitates in the micromechanical behavior of precipitate-strengthened shape memory alloys (SMAs), which still remains a mystery heretofore, is of crucial importance to the design of advanced SMAs with optimal functional and mechanical properties. Here, we investigate the lattice strain evolution of, and the stress partition between the nanoscale Ni4Ti3 precipitates and the matrix in a precipitate-strengthened Ni-Ti SMA during different deformation stages by in-situ synchrotron high-energy X-ray diffraction technique. We found that, during R-phase reorientation and stress-induced martensitic transformation, which both involve the shear deformation process, the lattice strain of the nanoscale precipitates drasticallymore » increases by a magnitude of 0.5%, which corresponds to an abrupt increase of ~520 MPa in internal stress. This indicates that stress repartition occurs and most of the stress is transferred to the precipitates during the shear deformation of the matrix. Lastly, it is further revealed that the nanoscale precipitates which only have a low volume fraction bear a considerable amount of applied stress during all deformation stages investigated, implying that the nanoscale precipitates play an important role in the deformation behavior of the precipitate-strengthened Ni-Ti SMAs.« less

  13. Stress transfer during different deformation stages in a nano-precipitate-strengthened Ni-Ti shape memory alloy

    SciTech Connect (OSTI)

    Dong, Y. H.; Cong, D. Y. He, Z. B.; Li, L. F.; Wang, Y. D.; Nie, Z. H.; Wang, Z. L.; Ren, Y.

    2015-11-16

    Understanding the role of fine coherent precipitates in the micromechanical behavior of precipitate-strengthened shape memory alloys (SMAs), which still remains a mystery heretofore, is of crucial importance to the design of advanced SMAs with optimal functional and mechanical properties. Here, we investigate the lattice strain evolution of, and the stress partition between the nanoscale Ni{sub 4}Ti{sub 3} precipitates and the matrix in a precipitate-strengthened Ni-Ti SMA during different deformation stages by in-situ synchrotron high-energy X-ray diffraction technique. We found that, during R-phase reorientation and stress-induced martensitic transformation, which both involve the shear deformation process, the lattice strain of the nanoscale precipitates drastically increases by a magnitude of 0.5%, which corresponds to an abrupt increase of ∼520 MPa in internal stress. This indicates that stress repartition occurs and most of the stress is transferred to the precipitates during the shear deformation of the matrix. It is further revealed that the nanoscale precipitates which only have a low volume fraction bear a considerable amount of applied stress during all deformation stages investigated, implying that the nanoscale precipitates play an important role in the deformation behavior of the precipitate-strengthened Ni-Ti SMAs.

  14. Probability of pipe fracture in the primary coolant loop of a PWR plant. Volume 3: nonseismic stress analysis. Final report

    SciTech Connect (OSTI)

    Chan, A.L.; Curtis, D.J.; Rybicki, E.F.; Lu, S.C.

    1981-08-01

    This volume describes the analyses used to evaluate stresses due to loads other than seismic excitations in the primary coolant loop piping of a selected four-loop pressurized water reactor nuclear power station. The results of the analyses are used as input to a simulation procedure for predicting the probability of pipe fracture in the primary coolant system. Sources of stresses considered in the analyses are pressure, dead weight, thermal expansion, thermal gradients through the pipe wall, residual welding, and mechanical vibrations. Pressure and thermal transients arising from plant operations are best estimates and are based on actual plant operation records supplemented by specified plant design conditions. Stresses due to dead weight and thermal expansion are computed from a three-dimensional finite element model that uses a combination of pipe, truss, and beam elements to represent the reactor coolant loop piping, reactor pressure vessel, reactor coolant pumps, steam generators, and the pressurizer. Stresses due to pressure and thermal gradients are obtained by closed-form solutions. Calculations of residual stresses account for the actual heat impact, welding speed, weld preparation geometry, and pre- and post-heat treatments. Vibrational stresses due to pump operation are estimated by a dynamic analysis using existing measurements of pump vibrations.

  15. Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material

    SciTech Connect (OSTI)

    G. Gordon

    2004-10-13

    Stress corrosion cracking is one of the most common corrosion-related causes for premature breach of metal structural components. Stress corrosion cracking is the initiation and propagation of cracks in structural components due to three factors that must be present simultaneously: metallurgical susceptibility, critical environment, and static (or sustained) tensile stresses. This report was prepared according to ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The purpose of this report is to provide an evaluation of the potential for stress corrosion cracking of the engineered barrier system components (i.e., the drip shield, waste package outer barrier, and waste package stainless steel inner structural cylinder) under exposure conditions consistent with the repository during the regulatory period of 10,000 years after permanent closure. For the drip shield and waste package outer barrier, the critical environment is conservatively taken as any aqueous environment contacting the metal surfaces. Appendix B of this report describes the development of the SCC-relevant seismic crack density model (SCDM). The consequence of a stress corrosion cracking breach of the drip shield, the waste package outer barrier, or the stainless steel inner structural cylinder material is the initiation and propagation of tight, sometimes branching, cracks that might be induced by the combination of an aggressive environment and various tensile stresses that can develop in the drip shields or the waste packages. The Stainless Steel Type 316 inner structural cylinder of the waste package is excluded from the stress corrosion cracking evaluation because the Total System Performance Assessment for License Application (TSPA-LA) does not take credit for the inner cylinder. This document provides a detailed description of the process-level models that can be applied to assess the performance of Alloy 22

  16. Effects of fluid shear stress on polyelectrolyte multilayers by neutron scattering studies

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Singh, Saurabh; Junghans, Ann; Watkins, Erik; Kapoor, Yash; Toomey, Ryan; Majewski, Jaroslaw

    2015-02-17

    The structure of layer-by-layer (LbL) deposited nanofilm coatings consists of alternating polyethylenimine (PEI) and polystyrenesulfonate (PSS) films deposited on a single crystal quartz substrate. LbL-deposited nanofilms were investigated by neutron reflectomery (NR) in contact with water in the static and fluid shear stress conditions. The fluid shear stress was applied through a laminar flow of the liquid parallel to the quartz/polymer interface in a custom-built solid–liquid interface cell. The scattering length density profiles obtained from NR results of these polyelectrolyte multilayers (PEM), measured under different shear conditions, showed proportional decrease of volume fraction of water hydrating the polymers. For themore » highest shear rate applied (ca. 6800 s–1) the water volume fraction decreased by approximately 7%. The decrease of the volume fraction of water was homogeneous through the thickness of the film. Since there were not any significant changes in the total polymer thickness, it resulted in negative osmotic pressures in the film. The PEM films were compared with the behavior of thin films of thermoresponsive poly(N-isopropylacrylamide) (pNIPAM) deposited via spin-coating. The PEM and pNIPAM differ in their interactions with water molecules, and they showed opposite behaviors under the fluid shear stress. In both cases the polymer hydration was reversible upon the restoration of static conditions. Furthermore, a theoretical explanation is given to explain this difference in the effect of shear on hydration of polymeric thin films.« less

  17. Early life low-level cadmium exposure is positively associated with increased oxidative stress

    SciTech Connect (OSTI)

    Kippler, Maria; Bakhtiar Hossain, Mohammad; Lindh, Christian; Moore, Sophie E.; Kabir, Iqbal; Vahter, Marie; Broberg, Karin

    2012-01-15

    Environmental exposure to cadmium (Cd) is known to induce oxidative stress, a state of imbalance between the production of reactive oxygen species (ROS) and the ability to detoxify them, in adults. However, data are lacking on potential effects in early-life. We evaluated urinary concentrations of 8-oxo-7,8-dihydro-2 Prime -deoxyguanosine (8-oxodG), a recognized marker of oxidative DNA damage, in relation to Cd exposure in 96 predominantly breast-fed infants (11-17 weeks of age) in rural Bangladesh. Urinary 8-oxodG was measured using liquid chromatography tandem mass spectrometry and Cd in urine and breast milk by inductively coupled plasma mass spectrometry. Median concentration of 8-oxodG was 3.9 nmol/L, urinary Cd 0.30 {mu}g/L, and breast-milk Cd 0.13 {mu}g/L. In linear regression analyses, urinary 8-oxodG was positively associated with Cd in both urine (p=0.00067) and breast milk (p=0.0021), and negatively associated with body weight (kg; p=0.0041). Adjustment for age, body weight, socio-economic status, urinary arsenic, as well as magnesium, calcium, and copper in breast milk did not change the association between Cd exposure and urinary 8-oxodG. These findings suggest that early-life low-level exposure to Cd via breast milk induces oxidative stress. Further studies are warranted to elucidate whether this oxidative stress is associated with impaired child health and development.

  18. Effect of local stress fields on twin characteristics in HCP metals

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Arul Kumar, M.; Beyerlein, Irene Jane; Tomé, Carlos N.

    2016-06-23

    Here we study the effect of nearest neighboring grains on the propensity for {1012} twin growth in Mg and Zr. Twin lamellae lying within one grain flanked by two neighboring grains with several orientations are considered. The fields of resolved shear stress on the twin system are calculated in the multicrystal using a three-dimensional full-field crystal plasticity Fast Fourier Transform approach. The calculations were carried out for Mg and Zr using slip threshold stresses corresponding to 300K and 76K, respectively, where twin activity is important. We show that the neighboring grain constraint tends to oppose further growth and that themore » critical applied stress needed to overcome this resistance depends on neighboring grain orientation, more strongly in Zr than in Mg. We also present results for a pair of adjacent and parallel twins at various spacings. It is found that their paired interaction increases the resistive forces for twin growth above that for an isolated twin. The critical spacing above which this enhanced resistance is removed is smaller for Zr than Mg. Our analysis reveals that these two disparate responses of Zr and Mg are both a consequence of the fact that Zr is elastically and plastically more anisotropic than Mg. Additional calculations carried out on Ti support this conclusion. Finally, these findings can help explain why, for the same grain size, more twins per grain form in Zr than in Mg, twins in Zr tend to be thinner than those in Mg, and the relationship between the thickness of the twin and its Schmid factor in Zr is not as strong as in Mg.« less

  19. Large-Scale, Continuous-Flow Production of Stressed Biomass (Desulfovibrio vulgaris Hildenborough)

    SciTech Connect (OSTI)

    Geller, Jil T.; Borglin, Sharon E.; Fortney, Julian L.; Lam, Bonita R.; Hazen, Terry C.; Biggin, Mark D.

    2010-05-01

    The Protein Complex Analysis Project (PCAP, http://pcap.lbl.gov/), focuses on high-throughput analysis of microbial protein complexes in the anaerobic, sulfate-reducing organism, DesulfovibriovulgarisHildenborough(DvH).Interest in DvHas a model organism for bioremediation of contaminated groundwater sites arises from its ability to reduce heavy metals. D. vulgarishas been isolated from contaminated groundwater of sites in the DOE complex. To understand the effect of environmental changes on the organism, midlog-phase cultures are exposed to nitrate and salt stresses (at the minimum inhibitory concentration, which reduces growth rates by 50percent), and compared to controls of cultures at midlogand stationary phases. Large volumes of culture of consistent quality (up to 100 liters) are needed because of the relatively low cell density of DvHcultures (one order of magnitude lower than E. coli, for example) and PCAP's challenge to characterize low-abundance membrane proteins. Cultures are grown in continuous flow stirred tank reactors (CFSTRs) to produce consistent cell densities. Stressor is added to the outflow from the CFSTR, and the mixture is pumped through a plug flow reactor (PFR), to provide a stress exposure time of 2 hours. Effluent is chilled and held in large carboys until it is centrifuged. A variety of analyses -- including metabolites, total proteins, cell density and phospholipidfatty-acids -- track culture consistency within a production run, and differences due to stress exposure and growth phase for the different conditions used. With our system we are able to produce the requisite 100 L of culture for a given condition within a week.

  20. Effect of silicon compounds on stress corrosion cracking of alloy 600 in caustic solutions

    SciTech Connect (OSTI)

    Navas, M.; Gomez-Briceno, D.; Garcia-Mazario, M.; McIlree, A.R.

    1999-07-01

    Silicon compounds are abundant in both steam generator tube deposits removed from operating plants and in the hideout return analyses performed during plant operation. Despite their abundance, the effect of these compounds on the susceptibility to intergranular attack (IGA) and stress corrosion cracking (SCC) of alloy 600 (UNS N06600) has not been established clearly in laboratory tests or under operating conditions. The present work studied the effect of different compounds of silicon, such as silica (SiO{sub 2}) and sodium metasilicate (Na{sub 2}SiO{sub 3}), on the susceptibility to IGA/SCC of alloy 600 in caustic solutions, with and without impurities. Experimental work included measurement of potentiodynamic polarization curves and development of stress corrosion tests with potentiostatic control at 315 C. Results of both tests indicated an inhibiting effect of silicon compounds on stress corrosion of mill-annealed (MA) alloy 600. Polarization curves in solutions with silicon compounds showed a wider range of passivation and a reduction in passive current density and anodic dissolution compared to the curves obtained in sodium hydroxide (NaOH). In corrosion tests performed in solutions containing silicon compounds, cracking appeared at only some of the potentials tested and with much reduced depth. Judging by the results obtained from analyses of the surface deposits, the inhibiting effect appeared to be related to the incorporation of silicon in the oxide layer. Regarding the effect of impurities, these have been observed not to be harmful for the response o alloy 600MA to IGA/SCC, and would appear even to improve this response in solutions containing silicon compounds, probably caused by the formation of insoluble silicates.