National Library of Energy BETA

Sample records for thermal cracking process

  1. Catalytic cracking process

    SciTech Connect (OSTI)

    Lokhandwala, Kaaeid A.; Baker, Richard W.

    2001-01-01

    Processes and apparatus for providing improved catalytic cracking, specifically improved recovery of olefins, LPG or hydrogen from catalytic crackers. The improvement is achieved by passing part of the wet gas stream across membranes selective in favor of light hydrocarbons over hydrogen.

  2. Process for magnetic beneficiating petroleum cracking catalyst

    DOE Patents [OSTI]

    Doctor, R.D.

    1993-10-05

    A process is described for beneficiating a particulate zeolite petroleum cracking catalyst having metal values in excess of 1000 ppm nickel equivalents. The particulate catalyst is passed through a magnetic field in the range of from about 2 Tesla to about 5 Tesla generated by a superconducting quadrupole open-gradient magnetic system for a time sufficient to effect separation of said catalyst into a plurality of zones having different nickel equivalent concentrations. A first zone has nickel equivalents of about 6,000 ppm and greater, a second zone has nickel equivalents in the range of from about 2000 ppm to about 6000 ppm, and a third zone has nickel equivalents of about 2000 ppm and less. The zones of catalyst are separated and the second zone material is recycled to a fluidized bed of zeolite petroleum cracking catalyst. The low nickel equivalent zone is treated while the high nickel equivalent zone is discarded. 1 figures.

  3. Process for magnetic beneficiating petroleum cracking catalyst

    DOE Patents [OSTI]

    Doctor, Richard D. (Lisle, IL)

    1993-01-01

    A process for beneficiating a particulate zeolite petroleum cracking catalyst having metal values in excess of 1000 ppm nickel equivalents. The particulate catalyst is passed through a magnetic field in the range of from about 2 Tesla to about 5 Tesla generated by a superconducting quadrupole open-gradient magnetic system for a time sufficient to effect separation of said catalyst into a plurality of zones having different nickel equivalent concentrations. A first zone has nickel equivalents of about 6,000 ppm and greater, a second zone has nickel equivalents in the range of from about 2000 ppm to about 6000 ppm, and a third zone has nickel equivalents of about 2000 ppm and less. The zones of catalyst are separated and the second zone material is recycled to a fluidized bed of zeolite petroleum cracking catalyst. The low nickel equivalent zone is treated while the high nickel equivalent zone is discarded.

  4. Sulfur distribution in the oil fractions obtained by thermal cracking of Jordanian El-Lajjun oil Shale

    E-Print Network [OSTI]

    Shawabkeh, Reyad A.

    by the thermal cracking process of the El-Lujjan oil shale showed that the yield of oil was around 12 wt of the boiling point for different distillate fractions. Sulfur in Jordanian oil shale was found to be mainly the dominant phases in these fractions. q 2005 Published by Elsevier Ltd. 1. Introduction Oil shale

  5. Effects of Matrix Cracks on the Thermal Diffusivity of a Fiber-Reinforced Ceramic Composite

    E-Print Network [OSTI]

    Zok, Frank

    Effects of Matrix Cracks on the Thermal Diffusivity of a Fiber-Reinforced Ceramic Composite conductances coupled with a unit cell model for a fiber composite containing a periodic array of matrix cracks tolerance and notch insensitivity in continuous fiber ceramic composites (CFCCs).1 These mechanisms play

  6. Thermal resistance of bridged cracks in fiber-reinforced ceramic John Dryden

    E-Print Network [OSTI]

    Zok, Frank

    -reinforced ceramic composites obtain high toughness is through the de- velopment of multiple matrix cracksThermal resistance of bridged cracks in fiber-reinforced ceramic composites John Dryden Department in a fiber-reinforced ceramic composite is analyzed. The problem is cast in terms of a unit cell comprising

  7. Process for thermal hydrocracking of coal

    SciTech Connect (OSTI)

    Yamashita, K.; Kimura, M.

    1983-11-01

    A process for liquefying and gasifying coal by thermal treatment in the presence of hydrogen gas for hydrocracking is disclosed. The process comprises a sequence of the following two steps: (1) coal fines are injected into a heated hydrogen gas stream at a pressure of from 35 to 250 kg/cm G such that they are rapidly heated to a temperature of from 750/sup 0/ to 1100/sup 0/ C. for thermal cracking thereof; and (2) the resulting liquid product is subjected to hydrocracking for a period of from 1.0 to 60 seconds at a temperature that is lower than the temperature used in the first step and which is in the range of from 570/sup 0/ to 850/sup 0/ C.

  8. Rapid thermal processing by stamping

    DOE Patents [OSTI]

    Stradins, Pauls; Wang, Qi

    2013-03-05

    A rapid thermal processing device and methods are provided for thermal processing of samples such as semiconductor wafers. The device has components including a stamp (35) having a stamping surface and a heater or cooler (40) to bring it to a selected processing temperature, a sample holder (20) for holding a sample (10) in position for intimate contact with the stamping surface; and positioning components (25) for moving the stamping surface and the stamp (35) in and away from intimate, substantially non-pressured contact. Methods for using and making such devices are also provided. These devices and methods allow inexpensive, efficient, easily controllable thermal processing.

  9. Continuous Processing of High Thermal Conductivity Polyethylene...

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

    Processing of High Thermal Conductivity Polyethylene Fibers and Sheets Continuous Processing of High Thermal Conductivity Polyethylene Fibers and Sheets Massachusetts Institute of...

  10. 3D MULTIPLE CRACK SYSTEM: EXTRACTION AND ANALYSIS USING MOTION-BASED IMAGE PROCESSING TECHNIQUE

    E-Print Network [OSTI]

    Nagy, George

    , including the number of cracks, surface area, volume, tortuosity, and permeability. Keywords: X-ray microtomography, image processing, concrete fracture. INTRODUCTION We examine the crack surfaces of concrete the fracture behavior of concrete, they have been ignored because "understanding of this problem

  11. Roles of grain boundaries in cleavage cracking and thermal crack arrest experiments in iron-silicon alloy

    E-Print Network [OSTI]

    Qiao, Yu, 1972-

    2002-01-01

    High-angle grain boundaries in steel offer an important resistance to the propagation of cleavage cracks that affects the fracture toughness and can modulate the ductile-to-brittle transition temperature of fracture downward. ...

  12. Materials Science and Engineering A 490 (2008) 2635 Mechanisms of cracking and delamination within thick thermal barrier

    E-Print Network [OSTI]

    Hutchinson, John W.

    2008-01-01

    that characterizes the susceptibility to delamination of thermal barrier coated (TBC) hot-section aero-turbine. Introduction The maximum temperature capability of thermal barrier systems used in gas turbines is oftenMaterials Science and Engineering A 490 (2008) 26­35 Mechanisms of cracking and delamination within

  13. Thermal effects in radiation processing

    SciTech Connect (OSTI)

    Zagorski, Z.P.

    1984-10-21

    The balance of ionizing radiation energy incident on an object being processed is discussed in terms of energy losses, influencing the amount really absorbed. To obtain the amount of heat produced, the absorbed energy is corrected for the change in internal energy of the system and for the heat effect of secondary reactions developing after the initiation. The temperature of a processed object results from the heat evolved and from the specific heat of the material comprising the object. The specific heat of most materials is usually much lower than that of aqueous systems and therefore temperatures after irradiation are higher. The role of low specific heat in radiation processing at cryogenic conditions is stressed. Adiabatic conditions of accelerator irradiation are contrasted with the steady state thermal conditions prevailing in large gamma sources. Among specific questions discussed in the last part of the paper are: intermediate and final temperature of composite materials, measurement of real thermal effects in situ, neutralization of undesired warming experienced during radiation processing, processing at temperatures other than ambient and administration of very high doses of radiation.

  14. Identification of sublimation-type thermal contraction crack polygons at the proposed NASA Phoenix landing site: Implications for substrate

    E-Print Network [OSTI]

    Marchant, David R.

    Identification of sublimation-type thermal contraction crack polygons at the proposed NASA Phoenix within the NASA Phoenix landing site Area D characterized by boulder-topped, polygonally-patterned mounds of buried ice. On the basis of morphological similarities, we classify the Phoenix Box 1 polygons

  15. WATTS TOWERS: THE EFFECTS OF THERMAL CYCLES ON THE FORMATION AND BEHAVIOR OF CRACKS 

    E-Print Network [OSTI]

    Spencer, Matthew T

    2013-02-06

    of cracks located at different sections on the Towers was outfitted with strain gauges, force transducers, and thermocouples to collect data on the crack width as a function of the ambient temperature. Using the Finite Element Analysis program LS-DYNA, a...

  16. Effects of thermal aging on Stress Corrosion Cracking and mechanical properties of stainless steel weld metals

    E-Print Network [OSTI]

    Hixon, Jeff

    2006-01-01

    Stress Corrosion Cracking (SCC) in and around primary loop piping welds in Boiling Water Reactors has been observed worldwide as plants continue to operate at temperatures and pressures near 2880C (5500F) and 6.9 MPa (1000 ...

  17. LABORATORY VI ENERGY AND THERMAL PROCESSES

    E-Print Network [OSTI]

    Minnesota, University of

    LABORATORY VI ENERGY AND THERMAL PROCESSES Lab VI - 1 The change of the internal energy of a system temperature. In this lab you will concentrate on quantifying the changes in internal energy within the framework of conservation of energy. In the problems of this lab, you will master the relation

  18. Hydrocarbon Liquid Production via the bioCRACK Process and Catalytic Hydroprocessing of the Product Oil

    SciTech Connect (OSTI)

    Schwaiger, Nikolaus; Elliott, Douglas C.; Ritzberger, Jurgen; Wang, Huamin; Pucher, Peter; Siebenhofer, Matthaus

    2015-01-01

    Continuous hydroprocessing of liquid phase pyrolysis bio-oil, provided by BDI-BioEnergy International bioCRACK pilot plant at OMV Refinery in Schwechat/Vienna Austria was investigated. These hydroprocessing tests showed promising results using catalytic hydroprocessing strategies developed for unfractionated bio-oil. A sulfided base metal catalyst (CoMo on Al2O3) was evaluated. The bed of catalyst was operated at 400 °C in a continuous-flow reactor at a pressure of 12.1 MPa with flowing hydrogen. The condensed liquid products were analyzed and found that the hydrocarbon liquid was significantly hydrotreated so that nitrogen and sulfur were below the level of detection (<0.05), while the residual oxygen ranged from 0.7 to 1.2%. The density of the products varied from 0.71 g/mL up to 0.79 g/mL with a correlated change of the hydrogen to carbon atomic ratio from 2.1 down to 1.9. The product quality remained high throughout the extended tests suggesting minimal loss of catalyst activity through the test. These tests provided the data needed to assess the quality of liquid fuel products obtained from the bioCRACK process as well as the activity of the catalyst for comparison with products obtained from hydrotreated fast pyrolysis bio-oils from fluidized-bed operation.

  19. Hydrocarbon Liquid Production via the bioCRACK Process and Catalytic Hydroprocessing of the Product Oil

    SciTech Connect (OSTI)

    Schwaiger, Nikolaus; Elliott, Douglas C.; Ritzberger, Jurgen; Wang, Huamin; Pucher, Peter; Siebenhofer, Matthaus

    2015-02-13

    Continuous hydroprocessing of liquid phase pyrolysis bio-oil, provided by BDI-BioEnergy International bioCRACK pilot plant at OMV Refinery in Schwechat/Vienna Austria was investigated. These hydroprocessing tests showed promising results using catalytic hydroprocessing strategies developed for unfractionated bio-oil. A sulfided base metal catalyst (CoMo on Al2O3) was evaluated. The bed of catalyst was operated at 400 °C in a continuous-flow reactor at a pressure of 12.1 MPa with flowing hydrogen. The condensed liquid products were analyzed and found that the hydrocarbon liquid was significantly hydrotreated so that nitrogen and sulfur were below the level of detection (<0.05), while the residual oxygen ranged from 0.7 to 1.2%. The density of the products varied from 0.71 g/mL up to 0.79 g/mL with a correlated change of the hydrogen to carbon atomic ratio from 2.1 down to 1.9. The product quality remained high throughout the extended tests suggesting minimal loss of catalyst activity through the test. These tests provided the data needed to assess the quality of liquid fuel products obtained from the bioCRACK process as well as the activity of the catalyst for comparison with products obtained from hydrotreated fast pyrolysis bio-oils from fluidized-bed operation.

  20. Hydrocarbon Liquid Production via the bioCRACK Process and Catalytic Hydroprocessing of the Product Oil

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

    Schwaiger, Nikolaus; Elliott, Douglas C.; Ritzberger, Jurgen; Wang, Huamin; Pucher, Peter; Siebenhofer, Matthaus

    2015-02-13

    Continuous hydroprocessing of liquid phase pyrolysis bio-oil, provided by BDI-BioEnergy International bioCRACK pilot plant at OMV Refinery in Schwechat/Vienna Austria was investigated. These hydroprocessing tests showed promising results using catalytic hydroprocessing strategies developed for unfractionated bio-oil. A sulfided base metal catalyst (CoMo on Al2O3) was evaluated. The bed of catalyst was operated at 400 °C in a continuous-flow reactor at a pressure of 12.1 MPa with flowing hydrogen. The condensed liquid products were analyzed and found that the hydrocarbon liquid was significantly hydrotreated so that nitrogen and sulfur were below the level of detection (more »from 0.7 to 1.2%. The density of the products varied from 0.71 g/mL up to 0.79 g/mL with a correlated change of the hydrogen to carbon atomic ratio from 2.1 down to 1.9. The product quality remained high throughout the extended tests suggesting minimal loss of catalyst activity through the test. These tests provided the data needed to assess the quality of liquid fuel products obtained from the bioCRACK process as well as the activity of the catalyst for comparison with products obtained from hydrotreated fast pyrolysis bio-oils from fluidized-bed operation.« less

  1. Solar Thermal Process Heat | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page| Open Energy Information Serbia-Enhancing Capacity forSilicium deEnergyCompany Limited SPCSolar Thermal Process Heat

  2. Hydrocarbon cracking

    SciTech Connect (OSTI)

    McCoy, R.D.

    1980-12-02

    A cracking reactor is controlled in response to the proportion of heavy aromatic constituents in a feedstock to be cracked.

  3. Harvesting thermal fluctuations: Activation process induced by a nonlinear chain in thermal equilibrium

    E-Print Network [OSTI]

    Galán, Antonio Sarmiento

    Harvesting thermal fluctuations: Activation process induced by a nonlinear chain in thermal of a bistable system is a molecular chain which in turn is connected to a thermal environment of the Langevin. The distribution, intensity, and mobility of thermal fluctuations in these chains is strongly dependent

  4. Thermal challenges in MEMS applications: phase change phenomena and thermal bonding processes

    E-Print Network [OSTI]

    Lin, Liwei

    Thermal challenges in MEMS applications: phase change phenomena and thermal bonding processes Liwei, MC 1740, Berkeley, CA 94720, USA Abstract Two thermal challenges for current and next generation generate single, spherical and controllable thermal bubbles with diameters between 2 and 500 mm. Both

  5. Effect of composition and processing on the thermal fatigue and toughness of high performance die steels. Final report

    SciTech Connect (OSTI)

    Wallace, J.F.; Wang, Y.; Schwam, D.

    1997-06-01

    The objective of this study was to improve average die life by optimizing die steel composition and the die processing. Four different steels, K,Q,C and Premium Grade H-13 have been investigated for thermal fatigue resistance and toughness. Optimum heat treatment processing has been determined for each steel with respect to austenitizing temperature and tempering conditions. The effect of the quenching rate on the thermal fatigue resistance and toughness of the die steels and the effect of Electro-Discharge Machining (EDM) on the thermal fatigue resistance were also determined. The immersion thermal fatigue specimen developed at CWRU was used to determine the thermal fatigue resistance as characterized by the two parameters of average maximum crack length and total crack area. The Charpy V-notch impact test was used over a -100{degrees}F to 450{degrees}F testing temperature range to evaluate the toughness and the brittle-ductile transition behavior. K steel has been identified as superior in performance compared to Premium Grade H-13. Q and C provide lower toughness and thermal fatigue resistance than H-13. Faster cooling rates provide higher thermal fatigue resistance and toughness. Higher austenitizing temperatures such as 1925{degrees}F compared to 1875{degrees}F provide better thermal fatigue resistance, but lower austenitizing temperatures of 1875{degrees}F provide better toughness. Higher hardness improves thermal fatigue resistance, but reduces toughness. A minimum of Rc 46 hardness is desired for aluminum die casting dies. EDM reduces the thermal fatigue resistance compared to conventional machining operations. When the EDM process of multiple small steps of decreasing energy and post-EDM treatments are employed, the effect can be reduced to a very slight amount. Preliminary evidence of the superior performance of the K steel has been provided by ongoing field testing of inserts in multiple cavity dies.

  6. Discrete Element Model for Simulations of Early-Life Thermal Fracturing Behaviors in Ceramic Nuclear Fuel Pellets

    SciTech Connect (OSTI)

    Hai Huang; Ben Spencer; Jason Hales

    2014-10-01

    A discrete element Model (DEM) representation of coupled solid mechanics/fracturing and heat conduction processes has been developed and applied to explicitly simulate the random initiations and subsequent propagations of interacting thermal cracks in a ceramic nuclear fuel pellet during initial rise to power and during power cycles. The DEM model clearly predicts realistic early-life crack patterns including both radial cracks and circumferential cracks. Simulation results clearly demonstrate the formation of radial cracks during the initial power rise, and formation of circumferential cracks as the power is ramped down. In these simulations, additional early-life power cycles do not lead to the formation of new thermal cracks. They do, however clearly indicate changes in the apertures of thermal cracks during later power cycles due to thermal expansion and shrinkage. The number of radial cracks increases with increasing power, which is consistent with the experimental observations.

  7. Stress corrosion crack growth in porous sandstones. 

    E-Print Network [OSTI]

    Ojala, Ira O

    Stress corrosion crack growth occurs when the chemical weakening of strained crack tip bonds facilitates crack propagation. I have examined the effect of chemical processes on the growth of a creack population by carrying out triaxial compression...

  8. 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.

  9. Pulse thermal processing of functional materials using directed plasma arc

    DOE Patents [OSTI]

    Ott, Ronald D. (Knoxville, TN); Blue, Craig A. (Knoxville, TN); Dudney, Nancy J. (Knoxville, TN); Harper, David C. (Kingston, TN)

    2007-05-22

    A method of thermally processing a material includes exposing the material to at least one pulse of infrared light emitted from a directed plasma arc to thermally process the material, the pulse having a duration of no more than 10 s.

  10. Conductive Thermal Interaction in Evaporative Cooling Process 

    E-Print Network [OSTI]

    Kim, B. S.; Degelman, L. O.

    1990-01-01

    between water and entering air for thermal comfort. This hybrid system outperforms the two-stage evaporative cooler without employing a complicated heat exchanger (indirect system), if the temperature of underground water is lower than the ambient wet...

  11. Thermally Activated Processes in Polymer Glasses

    E-Print Network [OSTI]

    V. Parihar; D. Drosdoff; A. Widom; Y. N. Srivastava

    2005-12-03

    A derivation is given for the Vogel-Fulcher-Tammann thermal activation law for the glassy state of a bulk polymer. Our microscopic considerations involve the entropy of closed polymer molecular chains (i.e. polymer closed strings). For thin film polymer glasses, one obtains open polymer strings in that the boundary surfaces serve as possible string endpoint locations. The Vogel-Fulcher-Tammann thermal activation law thereby holds true for a bulk polymer glass but is modified in the neighborhood of the boundaries of thin film polymers.

  12. Identifying and Understanding Environment-Induced Crack propagation Behavior in Ni-based Superalloy INCONEL 617

    SciTech Connect (OSTI)

    Ma, Longzhou

    2012-11-30

    The nickel-based superalloy INCONEL 617 is a candidate material for heat exchanger applications in the next-generation nuclear plant (NGNP) system. This project will study the crack propagation process of alloy 617 at temperatures of 650°C-950°C in air under static/cyclic loading conditions. The goal is to identify the environmental and mechanical damage components and to understand in-depth the failure mechanism. Researchers will measure the fatigue crack propagation (FCP) rate (da/dn) under cyclic and hold-time fatigue conditions, and sustained crack growth rates (da/dt) at elevated temperatures. The independent FCP process will be identified and the rate-controlled sustained loading crack process will be correlated with the thermal activation equation to estimate the oxygen thermal activation energy. The FCP-dependent model indicates that if the sustained loading crack growth rate, da/dt, can be correlated with the FCP rate, da/dn, at the full time dependent stage, researchers can confirm stress-accelerated grain-boundary oxygen embrittlement (SAGBOE) as a predominate effect. Following the crack propagation tests, the research team will examine the fracture surface of materials in various cracking stages using a scanning electron microscope (SEM) and an optical microscope. In particular, the microstructure of the crack tip region will be analyzed in depth using high resolution transmission electron microscopy (TEM) and electron energy loss spectrum (EELS) mapping techniques to identify oxygen penetration along the grain boundary and to examine the diffused oxygen distribution profile around the crack tip. The cracked sample will be prepared by focused ion beam nanofabrication technology, allowing researchers to accurately fabricate the TEM samples from the crack tip while minimizing artifacts. Researchers will use these microscopic and spectroscopic results to interpret the crack propagation process, as well as distinguish and understand the environment or SAGBOE damage process under hold-time fatigue and sustained loading conditions

  13. Thermal Phenomena in Fiber-reinforced Thermoplastic Tape Winding Process

    E-Print Network [OSTI]

    Daraio, Chiara

    Thermal Phenomena in Fiber-reinforced Thermoplastic Tape Winding Process: Computational Simulations-reinforced thermoplastic tapes, thermal simulation, convective coefficient of gas torches, fiber-reinforced thermoplastic a pre-impregnated fiber-reinforced thermoplastic tape is bounded on-line to the substrate. The bonding

  14. Process and apparatus for thermal enhancement

    DOE Patents [OSTI]

    Burrill, Jr., Charles E. (Billerica, MA); Smirlock, Martin E. (Brimfield, MA); Krepchin, Ira P. (Newton Upper Falls, MA)

    1984-06-26

    Thermal treatment apparatus for downhole deployment comprising a combustion stage with an elongated hot wall combustion zone for the substantially complete combustion of the fuel-air mixture and an ignition zone immediately upstream from the combustion zone in which a mixture of atomized liquid fuel and air at or below stoichiometric ratio is ignited; together with a water injection stage immediately downstream from the combustion zone through which essentially partuculate free high temperature combustion products flow from the combustion zone and into which water is sprayed. The resulting mixture of steam and combustion products is injected into an oil formation for enhancing the speed and effectiveness of reservoir response due to physical, chemical, and/or thermal stimulation interactions.

  15. Materials Selection Considerations for Thermal Process Equipment...

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

    high-temperature metallic materials for use in process heating applications such as burners, electrical heating elements, material handling, load support, and heater tubes, etc....

  16. Solar thermal aerosol flow reaction process

    DOE Patents [OSTI]

    Weimer, Alan W.; Dahl, Jaimee K.; Pitts, J. Roland; Lewandowski, Allan A.; Bingham, Carl; Tamburini, Joseph R.

    2005-03-29

    The present invention provides an environmentally beneficial process using concentrated sunlight to heat radiation absorbing particles to carry out highly endothermic gas phase chemical reactions ultimately resulting in the production of hydrogen or hydrogen synthesis gases.

  17. Non-thermal emission processes in massive binaries

    E-Print Network [OSTI]

    M. De Becker

    2007-09-26

    In this paper, I present a general discussion of several astrophysical processes likely to play a role in the production of non-thermal emission in massive stars, with emphasis on massive binaries. Even though the discussion will start in the radio domain where the non-thermal emission was first detected, the census of physical processes involved in the non-thermal emission from massive stars shows that many spectral domains are concerned, from the radio to the very high energies. First, the theoretical aspects of the non-thermal emission from early-type stars will be addressed. The main topics that will be discussed are respectively the physics of individual stellar winds and their interaction in binary systems, the acceleration of relativistic electrons, the magnetic field of massive stars, and finally the non-thermal emission processes relevant to the case of massive stars. Second, this general qualitative discussion will be followed by a more quantitative one, devoted to the most probable scenario where non-thermal radio emitters are massive binaries. I will show how several stellar, wind and orbital parameters can be combined in order to make some semi-quantitative predictions on the high-energy counterpart to the non-thermal emission detected in the radio domain. These theoretical considerations will be followed by a census of results obtained so far, and related to this topic... (see paper for full abstract)

  18. Technical resource document for assured thermal processing of wastes

    SciTech Connect (OSTI)

    Farrow, R.L.; Fisk, G.A.; Hartwig, C.M.; Hurt, R.H.; Ringland, J.T.; Swansiger, W.A.

    1994-06-01

    This document is a concise compendium of resource material covering assured thermal processing of wastes (ATPW), an area in which Sandia aims to develop a large program. The ATPW program at Sandia is examining a wide variety of waste streams and thermal processes. Waste streams under consideration include municipal, chemical, medical, and mixed wastes. Thermal processes under consideration range from various incineration technologies to non-incineration processes such as supercritical water oxidation or molten metal technologies. Each of the chapters describes the element covered, discusses issues associated with its further development and/or utilization, presents Sandia capabilities that address these issues, and indicates important connections to other ATPW elements. The division of the field into elements was driven by the team`s desire to emphasize areas where Sandia`s capabilities can lead to major advances and is therefore somewhat unconventional. The report will be valuable to Sandians involved in further ATPW program development.

  19. Process for fabricating composite material having high thermal conductivity

    DOE Patents [OSTI]

    Colella, Nicholas J. (Livermore, CA); Davidson, Howard L. (San Carlos, CA); Kerns, John A. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA)

    2001-01-01

    A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

  20. Thermal Insulation Performance in the Process Industries: Facts and Fallacies 

    E-Print Network [OSTI]

    Tye, R. P.

    1985-01-01

    stream_source_info ESL-IE-85-05-54.pdf.txt stream_content_type text/plain stream_size 24703 Content-Encoding ISO-8859-1 stream_name ESL-IE-85-05-54.pdf.txt Content-Type text/plain; charset=ISO-8859-1 THERMAL INSULATION... PERFORMANCE IN 'mE PROCESS INDUSTRIES: FACTS AND FALLACIES R.P. Tye Dynatech RID Company, Cambridge, MA, U.S.A. ABSTRACT The efficient use of thermal insulation materials and systems for design of cryogenic and elevated temperature process...

  1. Process management using component thermal-hydraulic function classes

    DOE Patents [OSTI]

    Morman, J.A.; Wei, T.Y.C.; Reifman, J.

    1999-07-27

    A process management expert system where following malfunctioning of a component, such as a pump, for determining system realignment procedures such as for by-passing the malfunctioning component with on-line speeds to maintain operation of the process at full or partial capacity or to provide safe shut down of the system while isolating the malfunctioning component. The expert system uses thermal-hydraulic function classes at the component level for analyzing unanticipated as well as anticipated component malfunctions to provide recommended sequences of operator actions. Each component is classified according to its thermal-hydraulic function, and the generic and component-specific characteristics for that function. Using the diagnosis of the malfunctioning component and its thermal hydraulic class, the expert system analysis is carried out using generic thermal-hydraulic first principles. One aspect of the invention employs a qualitative physics-based forward search directed primarily downstream from the malfunctioning component in combination with a subsequent backward search directed primarily upstream from the serviced component. Generic classes of components are defined in the knowledge base according to the three thermal-hydraulic functions of mass, momentum and energy transfer and are used to determine possible realignment of component configurations in response to thermal-hydraulic function imbalance caused by the malfunctioning component. Each realignment to a new configuration produces the accompanying sequence of recommended operator actions. All possible new configurations are examined and a prioritized list of acceptable solutions is produced. 5 figs.

  2. Process management using component thermal-hydraulic function classes

    DOE Patents [OSTI]

    Morman, James A. (Woodridge, IL); Wei, Thomas Y. C. (Downers Grove, IL); Reifman, Jaques (Western Springs, IL)

    1999-01-01

    A process management expert system where following malfunctioning of a component, such as a pump, for determining system realignment procedures such as for by-passing the malfunctioning component with on-line speeds to maintain operation of the process at full or partial capacity or to provide safe shut down of the system while isolating the malfunctioning component. The expert system uses thermal-hydraulic function classes at the component level for analyzing unanticipated as well as anticipated component malfunctions to provide recommended sequences of operator actions. Each component is classified according to its thermal-hydraulic function, and the generic and component-specific characteristics for that function. Using the diagnosis of the malfunctioning component and its thermal hydraulic class, the expert system analysis is carried out using generic thermal-hydraulic first principles. One aspect of the invention employs a qualitative physics-based forward search directed primarily downstream from the malfunctioning component in combination with a subsequent backward search directed primarily upstream from the serviced component. Generic classes of components are defined in the knowledge base according to the three thermal-hydraulic functions of mass, momentum and energy transfer and are used to determine possible realignment of component configurations in response to thermal-hydraulic function imbalance caused by the malfunctioning component. Each realignment to a new configuration produces the accompanying sequence of recommended operator actions. All possible new configurations are examined and a prioritized list of acceptable solutions is produced.

  3. GEOPHYSICAL RESEARCH LETTERS, VOL. ???, XXXX, DOI:10.1029/, How pore fluid pressurization influences crack tip processes

    E-Print Network [OSTI]

    GEOPHYSICAL RESEARCH LETTERS, VOL. ???, XXXX, DOI:10.1029/, How pore fluid pressurization temperature and pore pressure rises along a steadily propagating shear crack, assuming a given shear stress profile along the crack (i.e., initially neglecting effects of pore pressure on shear stress

  4. Thermal acidization and recovery process for recovering viscous petroleum

    DOE Patents [OSTI]

    Poston, Robert S. (Winter Park, FL)

    1984-01-01

    A thermal acidization and recovery process for increasing production of heavy viscous petroleum crude oil and synthetic fuels from subterranean hydrocarbon formations containing clay particles creating adverse permeability effects is described. The method comprises injecting a thermal vapor stream through a well bore penetrating such formations to clean the formation face of hydrocarbonaceous materials which restrict the flow of fluids into the petroleum-bearing formation. Vaporized hydrogen chloride is then injected simultaneously to react with calcium and magnesium salts in the formation surrounding the bore hole to form water soluble chloride salts. Vaporized hydrogen fluoride is then injected simultaneously with its thermal vapor to dissolve water-sensitive clay particles thus increasing permeability. Thereafter, the thermal vapors are injected until the formation is sufficiently heated to permit increased recovery rates of the petroleum.

  5. Characterization of Fatigue Cracking and Healing of Asphalt Mixtures 

    E-Print Network [OSTI]

    Luo, Xue

    2012-07-16

    Fatigue cracking is one of the most common distresses of asphalt pavements, whereas healing is a counter process to cracking which alleviates cracking damage and extends fatigue life of asphalt pavements. Most of existing ...

  6. Method and apparatus for thermal processing of semiconductor substrates

    DOE Patents [OSTI]

    Griffiths, Stewart K. (Danville, CA); Nilson, Robert H. (Cardiss, CA); Mattson, Brad S. (Los Gatos, CA); Savas, Stephen E. (Alameda, CA)

    2000-01-01

    An improved apparatus and method for thermal processing of semiconductor wafers. The apparatus and method provide the temperature stability and uniformity of a conventional batch furnace as well as the processing speed and reduced time-at-temperature of a lamp-heated rapid thermal processor (RTP). Individual wafers are rapidly inserted into and withdrawn from a furnace cavity held at a nearly constant and isothermal temperature. The speeds of insertion and withdrawal are sufficiently large to limit thermal stresses and thereby reduce or prevent plastic deformation of the wafer as it enters and leaves the furnace. By processing the semiconductor wafer in a substantially isothermal cavity, the wafer temperature and spatial uniformity of the wafer temperature can be ensured by measuring and controlling only temperatures of the cavity walls. Further, peak power requirements are very small compared to lamp-heated RTPs because the cavity temperature is not cycled and the thermal mass of the cavity is relatively large. Increased speeds of insertion and/or removal may also be used with non-isothermal furnaces.

  7. Method and apparatus for thermal processing of semiconductor substrates

    DOE Patents [OSTI]

    Griffiths, Stewart K. (Danville, CA); Nilson, Robert H. (Cardiss, CA); Mattson, Brad S. (Los Gatos, CA); Savas, Stephen E. (Alameda, CA)

    2002-01-01

    An improved apparatus and method for thermal processing of semiconductor wafers. The apparatus and method provide the temperature stability and uniformity of a conventional batch furnace as well as the processing speed and reduced time-at-temperature of a lamp-heated rapid thermal processor (RTP). Individual wafers are rapidly inserted into and withdrawn from a furnace cavity held at a nearly constant and isothermal temperature. The speeds of insertion and withdrawal are sufficiently large to limit thermal stresses and thereby reduce or prevent plastic deformation of the wafer as it enters and leaves the furnace. By processing the semiconductor wafer in a substantially isothermal cavity, the wafer temperature and spatial uniformity of the wafer temperature can be ensured by measuring and controlling only temperatures of the cavity walls. Further, peak power requirements are very small compared to lamp-heated RTPs because the cavity temperature is not cycled and the thermal mass of the cavity is relatively large. Increased speeds of insertion and/or removal may also be used with non-isothermal furnaces.

  8. Process modeling for the Integrated Thermal Treatment System (ITTS) study

    SciTech Connect (OSTI)

    Liebelt, K.H.; Brown, B.W.; Quapp, W.J.

    1995-09-01

    This report describes the process modeling done in support of the integrated thermal treatment system (ITTS) study, Phases 1 and 2. ITTS consists of an integrated systems engineering approach for uniform comparison of widely varying thermal treatment technologies proposed for treatment of the contact-handled mixed low-level wastes (MLLW) currently stored in the U.S. Department of Energy complex. In the overall study, 19 systems were evaluated. Preconceptual designs were developed that included all of the various subsystems necessary for a complete installation, from waste receiving through to primary and secondary stabilization and disposal of the processed wastes. Each system included the necessary auxiliary treatment subsystems so that all of the waste categories in the complex were fully processed. The objective of the modeling task was to perform mass and energy balances of the major material components in each system. Modeling of trace materials, such as pollutants and radioactive isotopes, were beyond the present scope. The modeling of the main and secondary thermal treatment, air pollution control, and metal melting subsystems was done using the ASPEN PLUS process simulation code, Version 9.1-3. These results were combined with calculations for the remainder of the subsystems to achieve the final results, which included offgas volumes, and mass and volume waste reduction ratios.

  9. Modelling aging effects on a thermal cycling absorption process column

    SciTech Connect (OSTI)

    Laquerbe, C.; Contreras, S.; Demoment, J.

    2008-07-15

    Palladium coated on alumina is used in hydrogen separation systems operated at CEA/Valduc, and more particularly in Thermal Cycling Absorption Process columns. With such materials, tritium decay is known to induce aging effects which have direct side effects on hydrogen isotopes absorption isotherms. Furthermore in a TCAP column, aging occurs in an heterogeneous way. The possible impacts of these intrinsic material evolutions on the separation performances are investigated here through a numerical approach. (authors)

  10. Advanced Reactors Thermal Energy Transport for Process Industries

    SciTech Connect (OSTI)

    P. Sabharwall; S.J. Yoon; M.G. McKellar; C. Stoots; George Griffith

    2014-07-01

    The operation temperature of advanced nuclear reactors is generally higher than commercial light water reactors and thermal energy from advanced nuclear reactor can be used for various purposes such as liquid fuel production, district heating, desalination, hydrogen production, and other process heat applications, etc. Some of the major technology challenges that must be overcome before the advanced reactors could be licensed on the reactor side are qualification of next generation of nuclear fuel, materials that can withstand higher temperature, improvement in power cycle thermal efficiency by going to combined cycles, SCO2 cycles, successful demonstration of advanced compact heat exchangers in the prototypical conditions, and from the process side application the challenge is to transport the thermal energy from the reactor to the process plant with maximum efficiency (i.e., with minimum temperature drop). The main focus of this study is on doing a parametric study of efficient heat transport system, with different coolants (mainly, water, He, and molten salts) to determine maximum possible distance that can be achieved.

  11. Electrophoretically active sol-gel processes to backfill, seal, and/or densify porous, flawed, and/or cracked coatings on electrically conductive material

    DOE Patents [OSTI]

    Panitz, Janda K. (Sandia Park, NM); Reed, Scott T. (Albuquerque, NM); Ashley, Carol S. (Albuquerque, NM); Neiser, Richard A. (Albuquerque, NM); Moffatt, William C. (Albuquerque, NM)

    1999-01-01

    Electrophoretically active sol-gel processes to fill, seal, and/or density porous, flawed, and/or cracked coatings on electrically conductive substrates. Such coatings may be dielectrics, ceramics, or semiconductors and, by the present invention, may have deposited onto and into them sol-gel ceramic precursor compounds which are subsequently converted to sol-gel ceramics to yield composite materials with various tailored properties.

  12. Electrophoretically active sol-gel processes to backfill, seal, and/or densify porous, flawed, and/or cracked coatings on electrically conductive material

    DOE Patents [OSTI]

    Panitz, J.K.; Reed, S.T.; Ashley, C.S.; Neiser, R.A.; Moffatt, W.C.

    1999-07-20

    Electrophoretically active sol-gel processes to fill, seal, and/or density porous, flawed, and/or cracked coatings on electrically conductive substrates. Such coatings may be dielectrics, ceramics, or semiconductors and, by the present invention, may have deposited onto and into them sol-gel ceramic precursor compounds which are subsequently converted to sol-gel ceramics to yield composite materials with various tailored properties. 6 figs.

  13. Corrigenda for Solar Engineering of Thermal Processes, Fourth Ed. J. A. Duffie and W. A. Beckman

    E-Print Network [OSTI]

    Wisconsin at Madison, University of

    Corrigenda for Solar Engineering of Thermal Processes, Fourth Ed. J. A. Duffie and W. A. Beckman 2 769 Eqn for i 30.7 should be 30.8 #12;Corrigenda for Solar Engineering of Thermal Processes, Third Ed

  14. Energy Efficient Process Heating: Insulation and Thermal Mass Kevin Carpenter and Kelly Kissock

    E-Print Network [OSTI]

    Kissock, Kelly

    1 Energy Efficient Process Heating: Insulation and Thermal Mass Kevin Carpenter and Kelly Kissock tanks and reducing thermal mass. A companion paper, Energy Efficiency Process Heating: Managing Air Flow of the oven/furnace. Reducing the quantity of energy lost to thermal mass in a process heating system saves

  15. Analysis of Zinc 65 Contamination after Vacuum Thermal Process

    SciTech Connect (OSTI)

    Korinko, Paul S.; Tosten, Michael H.

    2013-01-01

    Radioactive contamination with a gamma energy emission consistent with {sup 65}Zn was detected in a glovebox following a vacuum thermal process. The contaminated components were removed from the glovebox and subjected to examination. Selected analytical techniques were used to determine the nature of the precursor material, i.e., oxide or metallic, the relative transferability of the deposit and its nature. The deposit was determined to be borne from natural zinc and was further determined to be deposited as a metallic material from vapor.

  16. Thermally stable booster explosive and process for manufacture

    DOE Patents [OSTI]

    Quinlin, William T. (Amarillo, TX); Thorpe, Raymond (Amarillo, TX); Lightfoot, James M. (Amarillo, TX)

    2006-03-21

    A thermally stable booster explosive and process for the manufacture of the explosive. The product explosive is 2,4,7,9-tetranitro-10H-benzo[4,5]furo[3,2-b]indole (TNBFI). A reactant/solvent such as n-methylpyrrolidone (NMP) or dimethyl formamide (DMF) is made slightly basic. The solution is heated to reduce the water content. The solution is cooled and hexanitrostilbene is added. The solution is heated to a predetermined temperature for a specific time period, cooled, and the product is collected by filtration.

  17. Method for thermal processing alumina-enriched spinel single crystals

    DOE Patents [OSTI]

    Jantzen, C.M.

    1995-05-09

    A process for age-hardening alumina-rich magnesium aluminum spinel to obtain the desired combination of characteristics of hardness, clarity, flexural strength and toughness comprises selection of the time-temperature pair for isothermal heating followed by quenching. The time-temperature pair is selected from the region wherein the precipitate groups have the characteristics sought. The single crystal spinel is isothermally heated and will, if heated long enough pass from its single phase through two pre-precipitates and two metastable precipitates to a stable secondary phase precipitate within the spinel matrix. Quenching is done slowly at first to avoid thermal shock, then rapidly. 12 figs.

  18. Continuous Processing of High Thermal Conductivity Fibers and...

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

    defects thermal conductivity drops significantly We aim to fabricate a continuous film with high thermal conductivity by disentangling and aligning polymer chains ...

  19. Crack detection using pulsed eddy current stimulated thermography

    SciTech Connect (OSTI)

    Kostson, E.; Weekes, B.; Almond, D. P. [RCNDE, Department of Mechanical Engineering, University of Bath (United Kingdom); Wilson, J.; Tian, G. Y. [School of Electrical, Electronic and Computer Engineering, Newcastle University (United Kingdom)

    2011-06-23

    This contribution presents results from studies investigating factors that influence the detection of surface breaking cracks using pulsed eddy current thermography. The influences of the current strength and crack orientation in both ferromagnetic and non-ferromagnetic metals have been investigated. It has been found that crack detection is far more sensitive to crack orientation in non-ferromagnetic metals than in ferromagnetic metals. The effects of crack size on detectability are presented for a large number of steel, nickel alloy and titanium samples. Results of studies comparing crack images obtained prior and after coating a nickel alloy sample with a thermal barrier coating are presented.

  20. Thermal casting process for the preparation of membranes

    DOE Patents [OSTI]

    Caneba, G.T.M.; Soong, D.S.

    1985-07-10

    Disclosed is a method for providing anisotropic polymer membrane from a binary polymer/solvent solution using a thermal inversion process. A homogeneous binary solution is cast onto a support and cooled in such a way as to provide a differential in cooling rate across the thickness of the resulting membrane sheet. Isotropic or anisotropic structures of selected porosities can be produced, depending on the initial concentration of polymer in the selected solvent and on the extent of the differential in cooling rate. This differential results in a corresponding gradation in pore size. The method may be modified to provide a working skin by applying a rapid, high-temperature pulse to redissolve a predetermined thickness of the membrane at one of its faces and then freezing the entire structure.

  1. Thermal Analysis of Novel Underfill Materials with Optimum Processing Characteristics

    E-Print Network [OSTI]

    Harmon, Julie P.

    - date the morphology of these composites. © 2005 Wiley Peri- odicals, Inc. J Appl Polym Sci 98: 1300 chip. Polymers are thermally insulating mate- rials; the thermal conductivity of a typical polymer the compos- ite thermal conductivity up to 32.5 W/m K at the maximum filler loading of 78 vol %. Polymer

  2. Investigation of Cracked Lithium Hydride Reactor Vessels

    SciTech Connect (OSTI)

    bird, e.l.; mustaleski, t.m.

    1999-06-01

    Visual examination of lithium hydride reactor vessels revealed cracks that were adjacent to welds, most of which were circumferentially located in the bottom portion of the vessels. Sections were cut from the vessels containing these cracks and examined by use of the metallograph, scanning electron microscope, and microprobe to determine the cause of cracking. Most of the cracks originated on the outer surface just outside the weld fusion line in the base material and propagated along grain boundaries. Crack depths of those examined sections ranged from {approximately}300 to 500 {micro}m. Other cracks were reported to have reached a maximum depth of 1/8 in. The primary cause of cracking was the creation of high tensile stresses associated with the differences in the coefficients of thermal expansion between the filler metal and the base metal during operation of the vessel in a thermally cyclic environment. This failure mechanism could be described as creep-type fatigue, whereby crack propagation may have been aided by the presence of brittle chromium carbides along the grain boundaries, which indicates a slightly sensitized microstructure.

  3. PROCESS DESIGN AND CONTROL Efficient Conversion of Thermal Energy into Hydrogen: Comparing Two Methods

    E-Print Network [OSTI]

    Kjelstrup, Signe

    PROCESS DESIGN AND CONTROL Efficient Conversion of Thermal Energy into Hydrogen: Comparing Two for the production of hydrogen from water and high temperature thermal energy are presented and compared. Increasing for the production of hydrogen from water has received considerable attention.1 High temperature thermal energy

  4. Automated Process for the Fabrication of Highly Customized Thermally...

    Energy Savers [EERE]

    of Highly Customized Thermally Insulated Cladding Systems Addthis 1 of 2 Resin casting prototype Image: Worcester Polytechnic Institute 2 of 2 A project member completes...

  5. Automated Process for the Fabrication of Highly Customized Thermally...

    Energy Savers [EERE]

    older buildings therefore consume significant amounts of energy for heating and cooling in the US. Adding thermal insulation to the external facades of a building is one...

  6. Solar-thermal fluid-wall reaction processing

    DOE Patents [OSTI]

    Weimer, Alan W.; Dahl, Jaimee K.; Lewandowski, Allan A.; Bingham, Carl; Buechler, Karen J.; Grothe, Willy

    2006-04-25

    The present invention provides a method for carrying out high temperature thermal dissociation reactions requiring rapid-heating and short residence times using solar energy. In particular, the present invention provides a method for carrying out high temperature thermal reactions such as dissociation of hydrocarbon containing gases and hydrogen sulfide to produce hydrogen and dry reforming of hydrocarbon containing gases with carbon dioxide. In the methods of the invention where hydrocarbon containing gases are dissociated, fine carbon black particles are also produced. The present invention also provides solar-thermal reactors and solar-thermal reactor systems.

  7. Solar-Thermal Fluid-Wall Reaction Processing

    DOE Patents [OSTI]

    Weimer, A. W.; Dahl, J. K.; Lewandowski, A. A.; Bingham, C.; Raska Buechler, K. J.; Grothe, W.

    2006-04-25

    The present invention provides a method for carrying out high temperature thermal dissociation reactions requiring rapid-heating and short residence times using solar energy. In particular, the present invention provides a method for carrying out high temperature thermal reactions such as dissociation of hydrocarbon containing gases and hydrogen sulfide to produce hydrogen and dry reforming of hydrocarbon containing gases with carbon dioxide. In the methods of the invention where hydrocarbon containing gases are dissociated, fine carbon black particles are also produced. The present invention also provides solar-thermal reactors and solar-thermal reactor systems.

  8. Supporting technology for enhanced oil recovery for thermal processes

    SciTech Connect (OSTI)

    Reid, T.B.; Bolivar, J.

    1997-12-01

    This report contains the results of efforts under the six tasks of the Ninth Amendment and Extension of Annex IV, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Agreement. The report is presented in sections (for each of the 6 tasks) and each section contains one or more reports prepared by various individuals or groups describing the results of efforts under each of the tasks. A statement of each task, taken from the agreement, is presented on the first page of each section. The tasks are numbered 62 through 67. The first, second, third, fourth fifth, sixth, seventh, eighth, and ninth reports on Annex IV, [Venezuela MEM/USA-DOE Fossil Energy Report IV-1, IV-2, IV-3, IV-4, IV-5, IV-6, IV-7, and IV-8 (DOE/BETC/SP-83/15, DOE/BC-84/6/SP, DOE/BC-86/2/SP, DOE/BC-87/2/SP, DOE/BC-90/1/SP, DOE/BC-90/1/SP) (DOE/BC-92/1/SP, DOE/BC-93/3/SP, and DOE/BC-95/3/SP)] contain the results from the first 61 tasks. Those reports are dated April 1983, August 1984, March 1986, July 1987, November 1988, October 1991, February 1993, and March 1995 respectively.

  9. Study on grain boundary character and strain distribution of intergranular cracking in the CGHAZ of T23 steel

    SciTech Connect (OSTI)

    Jin, Y.J.; Lu, H., E-mail: shweld@sjtu.edu.cn; Yu, C.; Xu, J.J.

    2013-10-15

    Intergranular reheat cracking in the coarse-grained heat-affected zone of T23 steel was produced by strain to fracture tests on a Gleeble 3500 thermal–mechanical simulator. Then the grain boundary character, as well as the strain distribution after reheat crack propagation, was studied by electron backscatter diffraction technique. The results showed that incoherent ?3 boundaries were seldom found on the prior austenite grain boundaries. Therefore, only the type of random high-angle boundaries played a crucial role in the intergranular cracking. Microstructurally cavities and small cracks were preferentially initiated from high-angle grain boundaries. Low-angle grain boundaries and high-angle ones with misorientation angles less than 15° were more resistant to the cracking. More importantly, the fraction of high-angle grain boundaries increased with the plastic strain induced by both temperature gradient and stress in the coarse-grained heat-affected zone, which contributed to the crack initiation and propagation. Furthermore, the strain distributions in the vicinity of cavities and cracks revealed the accommodation processes of plastic deformation during stress relaxation. It also reflected the strength differences between grain interior and grain boundary at different heat-treated temperatures, which had a large influence on the cracking mechanism. - Highlights: • The coincidence site lattice boundaries play little role in the reheat cracking. • Cavity and crack occur at high-angle grain boundaries rather than low-angle ones. • The strain leads low-angle grain boundaries to transform to high-angle ones. • Strain distribution differs for cavity and crack zones at different temperatures.

  10. Avoiding Carbon Bed Hot Spots in Thermal Process Off-Gas Systems...

    Office of Scientific and Technical Information (OSTI)

    Hot Spots in Thermal Process Off-Gas Systems Mercury has had various uses in nuclear fuel reprocessing and other nuclear processes, and so is often present in radioactive and...

  11. Monitoring of thermal enhanced oil recovery processes with electromagnetic methods

    SciTech Connect (OSTI)

    Wilt, M.

    1992-09-01

    Research in applying electromagnetic methods for imaging thermal enhanced oil recovery has progressed significantly during the past eighteen months. Working together with researchers at Lawrence Berkeley Laboratory (LBL) and supported by a group of industrial sponsors we have focused our effort on field system development and doing field surveys connected with EOR operations. Field surveys were recently completed at the Lost Hills No.3 oil field and at UC Richmond Field station. At Lost Hills, crosshole EM data sets were collected before a new phase of steam injection for EOR and again four months after the onset of steaming. The two data sets were nearly identical suggesting that very little steam had been injected into this borehole. This is in accord with the operators records which indicate injectivity problems with this particular well. At Richmond we conducted a salt water injection monitoring experiment where 50,000 gallons of salt water were injected in a shallow aquifer and crosshole EM data were collected using the injection well and several observation wells. We applied the imaging code to some of the collected data and produced an image showing that the salt water slug has propagated 8--10 m from the injector into the aquifer. This result is partially confirmed by prior calculations and well logging data. Applying the EM methods to the problem of oil field characterization essentially means extending the borehole resistivity log into the region between wells. Since the resistivity of a sedimentary environment is often directly dependent on the fluids in the rock the knowledge of the resistivity distribution within an oil field can be invaluable for finding missed or bypassed oil or for mapping the overall structure. With small modification the same methods used for mapping EOR process can be readily applied to determining the insitu resistivity structure.

  12. Hydrocarbon Processing`s refining processes `96

    SciTech Connect (OSTI)

    NONE

    1996-11-01

    The paper compiles information on the following refining processes: alkylation, benzene reduction, benzene saturation, catalytic cracking, catalytic reforming, coking, crude distillation, deasphalting, deep catalytic cracking, electrical desalting, ethers, fluid catalytic cracking, hydrocracking, hydrogenation, hydrotreating, isomerization, resid catalytic cracking, treating, and visbreaking. The application, products, a description of the process, yield, economics, installation, and licensor are given for each entry.

  13. Representation of thermal energy in the design process

    E-Print Network [OSTI]

    Roth, Shaun

    1995-01-01

    The goal of thermal design is to go beyond the comfort zone. In spatial design architects don't just look up square footage requirements and then draw a rectangle that satisfies the givens. There must be an interpretation. ...

  14. Shadows and Cracks

    E-Print Network [OSTI]

    Dowson, Mark

    The VIRGIN program will interpret pictures of crack and shadow free scenes by labelling them according to the Clowes/Huffman formalism. This paper indicates methods of extending the program to include cracks and shadows ...

  15. Crack coalescence in granite

    E-Print Network [OSTI]

    Miller, James Thomas, Ph. D. Massachusetts Institute of Technology

    2008-01-01

    This thesis experimentally investigates crack coalescence in prismatic Barre Granite specimens with two pre-cut, open flaws under uniaxial compression. Using a high-speed video system, crack initiation, propagation, and ...

  16. Nonlinear structural crack growth monitoring

    DOE Patents [OSTI]

    Welch, Donald E. (Oak Ridge, TN); Hively, Lee M. (Philadelphia, TN); Holdaway, Ray F. (Clinton, TN)

    2002-01-01

    A method and apparatus are provided for the detection, through nonlinear manipulation of data, of an indicator of imminent failure due to crack growth in structural elements. The method is a process of determining energy consumption due to crack growth and correlating the energy consumption with physical phenomena indicative of a failure event. The apparatus includes sensors for sensing physical data factors, processors or the like for computing a relationship between the physical data factors and phenomena indicative of the failure event, and apparatus for providing notification of the characteristics and extent of such phenomena.

  17. DETERMINATION OF THE UAV POSITION BY AUTOMATIC PROCESSING OF THERMAL IMAGES

    E-Print Network [OSTI]

    Schindler, Konrad

    DETERMINATION OF THE UAV POSITION BY AUTOMATIC PROCESSING OF THERMAL IMAGES Wilfried Hartmann.hartmann, sebastian.tilch, henri.eisenbeiss, konrad.schindler)@geod.baug.ethz.ch KEY WORDS: Thermal, UAV, Camera, Calibration, Bundle, Photogrammetry, GPS/INS ABSTRACT: If images acquired from Unmanned Aerial Vehicles (UAVs

  18. Process of making cryogenically cooled high thermal performance crystal optics

    DOE Patents [OSTI]

    Kuzay, T.M.

    1992-06-23

    A method is disclosed for constructing a cooled optic wherein one or more cavities are milled, drilled or formed using casting or ultrasound laser machining techniques in a single crystal base and filled with porous material having high thermal conductivity at cryogenic temperatures. A non-machined strain-free single crystal can be bonded to the base to produce superior optics. During operation of the cooled optic, N[sub 2] is pumped through the porous material at a sub-cooled cryogenic inlet temperature and with sufficient system pressure to prevent the fluid bulk temperature from reaching saturation. 7 figs.

  19. Application of the cracked pipe element to creep crack growth prediction

    SciTech Connect (OSTI)

    Brochard, J.; Charras, T.

    1997-04-01

    The modification of a computer code for leak before break analysis is very briefly described. The CASTEM2000 code was developed for ductile fracture assessment of piping systems with postulated circumferential through-wall cracks under static or dynamic loading. The modification extends the capabilities of the cracked pipe element to the determination of fracture parameters under creep conditions (C*, {phi}c and {Delta}c). The model has the advantage of evaluating significant secondary effects, such as those from thermal loading.

  20. Processing and thermal properties of molecularly oriented polymers

    E-Print Network [OSTI]

    Skow, Erik (Erik Dean)

    2007-01-01

    High molecular weight polymers that are linear in molecular construction can be oriented such that some of their physical properties in the oriented direction are enhanced. For over 50 years polymer orientation and processing ...

  1. Optimization of PZT processing using thermal ink-jet printing

    E-Print Network [OSTI]

    Jeon, Jessie Sungyun

    2008-01-01

    Lead zirconate titanate (PZT) has been known for its strong piezoelectric property for micro-sensors and actuators. Yet, its use in MEMS has been constrained by limitations in processing PZT with current MEMS fabrication ...

  2. A model of the thermal processing of particles in solar nebula shocks: Application to the cooling rates of chondrules

    E-Print Network [OSTI]

    Connolly Jr, Harold C.

    A model of the thermal processing of particles in solar nebula shocks: Application to the cooling for the thermal processing of particles in shock waves typical of the solar nebula. This shock model improves are accounted for in their ef fects on the mass, momentum and energy fluxes. Also, besides thermal exchange

  3. PVD thermal barrier coating applications and process development for aircraft engines

    SciTech Connect (OSTI)

    Rigney, D.V.; Viguie, R.; Wortman, D.J.; Skelly, D.W.

    1995-10-01

    Thermal barrier coatings (TBC`s) have been developed for application to aircraft engine components to improve the life in an increasingly hostile thermal environment. The choice of TBC type is related to the component, intended use and economics. The selection of electron beam physical vapor deposition (EB PVD) processing for turbine blades is due in part to part size, surface finish requirements, thickness control needs, and hole closure issues. Process development of PVD TBC`s has been carried out at several different sites including GEAE. Some of the influences of processing variables on microstructure are discussed. The GEAE development coater and initial experiences of pilot line operation are discussed.

  4. The relationship between crack-tip strain and subcritical cracking...

    Office of Scientific and Technical Information (OSTI)

    crack-tip strain and subcritical cracking thresholds for steels in high-pressure hydrogen gas. Citation Details In-Document Search Title: The relationship between crack-tip...

  5. Irradiation-Assisted Stress Corrosion Cracking of Austenitic Stainless Steels in BWR Environments

    SciTech Connect (OSTI)

    Chen, Y.; Chopra, O. K.; Gruber, Eugene E.; Shack, William J.

    2010-06-01

    The internal components of light water reactors are exposed to high-energy neutron irradiation and high-temperature reactor coolant. The exposure to neutron irradiation increases the susceptibility of austenitic stainless steels (SSs) to stress corrosion cracking (SCC) because of the elevated corrosion potential of the reactor coolant and the introduction of new embrittlement mechanisms through radiation damage. Various nonsensitized SSs and nickel alloys have been found to be prone to intergranular cracking after extended neutron exposure. Such cracks have been seen in a number of internal components in boiling water reactors (BWRs). The elevated susceptibility to SCC in irradiated materials, commonly referred to as irradiation-assisted stress corrosion cracking (IASCC), is a complex phenomenon that involves simultaneous actions of irradiation, stress, and corrosion. In recent years, as nuclear power plants have aged and irradiation dose increased, IASCC has become an increasingly important issue. Post-irradiation crack growth rate and fracture toughness tests have been performed to provide data and technical support for the NRC to address various issues related to aging degradation of reactor-core internal structures and components. This report summarizes the results of the last group of tests on compact tension specimens from the Halden-II irradiation. The IASCC susceptibility of austenitic SSs and heat-affected-zone (HAZ) materials sectioned from submerged arc and shielded metal arc welds was evaluated by conducting crack growth rate and fracture toughness tests in a simulated BWR environment. The fracture and cracking behavior of HAZ materials, thermally sensitized SSs and grain-boundary engineered SSs was investigated at several doses (?3 dpa). These latest results were combined with previous results from Halden-I and II irradiations to analyze the effects of neutron dose, water chemistry, alloy compositions, and welding and processing conditions on IASCC. The effect of neutron irradiation on the fracture toughness of austenitic SSs was also evaluated at dose levels relevant to BWR internals.

  6. CFD Modeling of Thermal Effects of Nuclear Waste Vitrification Processes

    SciTech Connect (OSTI)

    Rayner, Chris; Soltani, Mehdi; Barringer, Chris; Knight, Kelly

    2006-07-01

    The Waste Treatment Plant (WTP) at Hanford, WA will vitrify nuclear waste stored at the DOE Hanford facility. The vitrification process will take place in two large concrete buildings where the glass is poured into stainless steel canisters or containers and allowed to cool. Computational Fluid Dynamics (CFD) was used extensively to calculate the effects of the heat released by molten glass as it is poured and cooled, on the HVAC system and the building structure. CFD studies of the glass cooling in these facilities were used to predict canister temperatures, HVAC air temperatures, concrete temperatures and insulation requirements, and design temperatures for canister handling equipment and instrumentation at various stages of the process. These predictions provided critical input in the design of the HVAC system, specification of insulation, the design of canister handling equipment, and the selection of instrumentation. (authors)

  7. Application of the cracked pipe element to creep crack growth prediction

    SciTech Connect (OSTI)

    Brochard, J.; Charras, T. [C.E.A.-C.E.-Saclay DRN/DMT, Gif Sur Yvette (France); Ghoudi, M. [C.E.A.-C.E.-Saclay, Gif Sur Yvette (France)

    1997-04-01

    Modifications to a computer code for ductile fracture assessment of piping systems with postulated circumferential through-wall cracks under static or dynamic loading are very briefly described. The modifications extend the capabilities of the CASTEM2000 code to the determination of fracture parameters under creep conditions. The main advantage of the approach is that thermal loads can be evaluated as secondary stresses. The code is applicable to piping systems for which crack propagation predictions differ significantly depending on whether thermal stresses are considered as primary or secondary stresses.

  8. Composite material having high thermal conductivity and process for fabricating same

    DOE Patents [OSTI]

    Colella, N.J.; Davidson, H.L.; Kerns, J.A.; Makowiecki, D.M.

    1998-07-21

    A process is disclosed for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost. 7 figs.

  9. Turbulent thermalization process in high-energy heavy-ion collisions

    E-Print Network [OSTI]

    Jürgen Berges; Björn Schenke; Sören Schlichting; Raju Venugopalan

    2014-09-05

    We discuss the onset of the thermalization process in high-energy heavy-ion collisions from a weak coupling perspective, using classical-statistical real-time lattice simulations as a first principles tool to study the pre-equilibrium dynamics. Most remarkably, we find that the thermalization process is governed by a universal attractor, where the space-time evolution of the plasma becomes independent of the initial conditions and exhibits the self-similar dynamics characteristic of wave turbulence. We discuss the consequences of our weak coupling results for the thermalization process in heavy-ion experiments and briefly comment on the use of weak coupling techniques at larger values of the coupling.

  10. Composite material having high thermal conductivity and process for fabricating same

    DOE Patents [OSTI]

    Colella, Nicholas J. (Livermore, CA); Davidson, Howard L. (San Carlos, CA); Kerns, John A. (Livermore, CA); Makowiecki, Daniel M. (Livermore, CA)

    1998-01-01

    A process for fabricating a composite material such as that having high thermal conductivity and having specific application as a heat sink or heat spreader for high density integrated circuits. The composite material produced by this process has a thermal conductivity between that of diamond and copper, and basically consists of coated diamond particles dispersed in a high conductivity metal, such as copper. The composite material can be fabricated in small or relatively large sizes using inexpensive materials. The process basically consists, for example, of sputter coating diamond powder with several elements, including a carbide forming element and a brazeable material, compacting them into a porous body, and infiltrating the porous body with a suitable braze material, such as copper-silver alloy, thereby producing a dense diamond-copper composite material with a thermal conductivity comparable to synthetic diamond films at a fraction of the cost.

  11. Process to improve boiler operation by supplemental firing with thermally beneficiated low rank coal

    DOE Patents [OSTI]

    Sheldon, Ray W. (Huntley, MT)

    2001-01-01

    The invention described is a process for improving the performance of a commercial coal or lignite fired boiler system by supplementing its normal coal supply with a controlled quantity of thermally beneficiated low rank coal, (TBLRC). This supplemental TBLRC can be delivered either to the solid fuel mill (pulverizer) or directly to the coal burner feed pipe. Specific benefits are supplied based on knowledge of equipment types that may be employed on a commercial scale to complete the process. The thermally beneficiated low rank coal can be delivered along with regular coal or intermittently with regular coal as the needs require.

  12. Thermal Equilibrium in Nebulae1 For an ionized nebula under steady conditions, heating and cooling processes that in

    E-Print Network [OSTI]

    Boettcher, Markus

    processes that in isolation would change the thermal energy content of the gas are in balance to as a "photoelectron"). This kinetic energy represents an addition to the thermal energy of the gas bookkeeping for ionization. II. Cooling. Cooling occurs when thermal energy in the gas particles is converted

  13. Application of flash-assist rapid thermal processing subsequent to low-temperature furnace anneals

    E-Print Network [OSTI]

    Florida, University of

    Application of flash-assist rapid thermal processing subsequent to low-temperature furnace anneals and then implanted with 1 keV, 1 1015 cm-2 B. Low-temperature furnace anneals are performed at 500 °C for 30 minV. Implants were per- formed at a standard tilt of 7° and twist of 27°. Low- temperature furnace anneals were

  14. Effect of CTE on Fatigue Cracking of Stainless Steel Vessels

    SciTech Connect (OSTI)

    Bird, E. L.; Mustaleski, T. M.

    2002-01-31

    Visual examination of lithium hydride reactor vessels revealed cracks that were adjacent to welds. Most cracks were parallel to the weld in the bottom portion of the vessel. Sections were cut out of the vessel containing these cracks and examined using the metallograph, scanning electron microscope, and microprobe to determine the cause of cracking. most of the cracks originated on the outer surface just outside the weld fusion line in the heat affected zone and propagated along grain boundaries. Crack depth of those sections examined ranged from about 300 to 500 {micro}m. Other cracks were reported to have reached a maximum depth of 0.32-cm (0.125-inch). The primary cause of cracking was the creation of high tensile stresses associated with the CTE differences between the filler metal and the base metal during operation of the vessel in a thermally cyclic environment. This failure mechanism could be described as creep-type fatigue whereby crack propagation might have been aided by the presence of brittle chromium carbides along the grain boundaries, which is indicative of a slightly sensitized microstructure.

  15. Process for detoxifying coal tars

    DOE Patents [OSTI]

    Longwell, John P. (Cambridge, MA); Peters, William A. (Arlington, MA)

    1983-01-01

    A process for treating liquid hydrocarbons to remove toxic, mutagenic and/or carcinogenic aromatic hydrocarbons comprises feeding the hydrocarbons into a reactor where vapors are thermally treated in contact with a catalyst consisting essentially of calcium oxide or a calcium oxide containing mineral. Thermally treating liquid hydrocarbons in contact with calcium oxide preferentially increases the cracking of aromatics thus producing a product having a reduced amount of aromatic compounds.

  16. Effects Of Thermal Exchange On Material Flow During Steel Thixoextrusion Process

    SciTech Connect (OSTI)

    Becker, Eric; Gu Guochao; Langlois, Laurent; Bigot, Regis; Pesci, Raphael

    2011-01-17

    Semisolid processing is an innovative technology for near net-shape production of components, where the metallic alloys are processed in the semisolid state. Taking advantage of the thixotropic behavior of alloys in the semisolid state, significant progress has been made in semisolid processing. However, the consequences of such behavior on the flow during thixoforming are still not completely understood. To explore and better understand the influence of the different parameters on material flow during thixoextrusion process, thixoextrusion experiments were performed using the low carbon steel C38. The billet was partially melted at high solid fraction. Effects of various process parameters including the initial billet temperature, the temperature of die, the punch speed during process and the presence of a Ceraspray layer at the interface of tool and billet were investigated through experiments and simulation. After analyzing the results thus obtained, it was identified that the aforementioned parameters mainly affect thermal exchanges between die and part. The Ceraspray layer not only plays a lubricant role, but also acts as a thermal barrier at the interface of tool and billet. Furthermore, the thermal effects can affect the material flow which is composed of various distinct zones.

  17. Modeling of thermally driven hydrological processes in partially saturated fractured rock

    SciTech Connect (OSTI)

    Tsang, Yvonne; Birkholzer, Jens; Mukhopadhyay, Sumit

    2009-03-15

    This paper is a review of the research that led to an in-depth understanding of flow and transport processes under strong heat stimulation in fractured, porous rock. It first describes the anticipated multiple processes that come into play in a partially saturated, fractured porous volcanic tuff geological formation, when it is subject to a heat source such as that originating from the decay of radionuclides. The rationale is then given for numerical modeling being a key element in the study of multiple processes that are coupled. The paper outlines how the conceptualization and the numerical modeling of the problem evolved, progressing from the simplified to the more realistic. Examples of numerical models are presented so as to illustrate the advancement and maturation of the research over the last two decades. The most recent model applied to in situ field thermal tests is characterized by (1) incorporation of a full set of thermal-hydrological processes into a numerical simulator, (2) realistic representation of the field test geometry, in three dimensions, and (3) use of site-specific characterization data for model inputs. Model predictions were carried out prior to initiation of data collection, and the model results were compared to diverse sets of measurements. The approach of close integration between modeling and field measurements has yielded a better understanding of how coupled thermal hydrological processes produce redistribution of moisture within the rock, which affects local permeability values and subsequently the flow of liquid and gases. The fluid flow in turn will change the temperature field. We end with a note on future research opportunities, specifically those incorporating chemical, mechanical, and microbiological factors into the study of thermal and hydrological processes.

  18. Experimental investigation for hydrogen and deuterium separation by thermal cycling absorption process

    SciTech Connect (OSTI)

    Guangda, L.; Guoqiang, J.; Cansheng, S.

    1995-10-01

    The Thermal Cycling Absorption Process (TCAP) is a semicontinuous gas chromatographic process for hydrogen isotope separation by which the experiment for hydrogen-deuterium separation has been carried out. The main operating parameters for optimum separation were obtained. On manual operation conditions the concentrations of product and raffinate gas were better than 99.5% simultaneously at a feed rate of 12.0% for a 1:1 hydrogen-deuterium mixture. Besides, TCAP is a good process for trace heavier isotope enriching from hydrogen. The concentration of deuterium can be reduced from 0.5% to less than 50ppm in hydrogen in ten cycles. 5 refs., 4 figs.

  19. Thermal barrier coating deposition by rarefied gas jet assisted processes: Simulations of deposition on a stationary airfoil

    E-Print Network [OSTI]

    Wadley, Haydn

    Thermal barrier coating deposition by rarefied gas jet assisted processes: Simulations) The uniform coating of a complex shaped substrate, such as a gas turbine airfoil, by collisionless physical thermal barrier coating are used to investigate fundamental aspects of the deposition process, including

  20. Structurally Integrated Coatings for Wear and Corrosion (SICWC): Arc Lamp, InfraRed (IR) Thermal Processing

    SciTech Connect (OSTI)

    Mackiewicz-Ludtka, G.; Sebright, J.

    2007-12-15

    The primary goal of this Cooperative Research and Development Agreement (CRADA) betwe1311 UT-Battelle (Contractor) and Caterpillar Inc. (Participant) was to develop the plasma arc lamp (PAL), infrared (IR) thermal processing technology 1.) to enhance surface coating performance by improving the interfacial bond strength between selected coatings and substrates; and 2.) to extend this technology base for transitioning of the arc lamp processing to the industrial Participant. Completion of the following three key technical tasks (described below) was necessary in order to accomplish this goal. First, thermophysical property data sets were successfully determined for composite coatings applied to 1010 steel substrates, with a more limited data set successfully measured for free-standing coatings. These data are necessary for the computer modeling simulations and parametric studies to; A.) simulate PAL IR processing, facilitating the development of the initial processing parameters; and B.) help develop a better understanding of the basic PAL IR fusing process fundamentals, including predicting the influence of melt pool stirring and heat tnmsfar characteristics introduced during plasma arc lamp infrared (IR) processing; Second, a methodology and a set of procedures were successfully developed and the plasma arc lamp (PAL) power profiles were successfully mapped as a function of PAL power level for the ORNL PAL. The latter data also are necessary input for the computer model to accurately simulate PAL processing during process modeling simulations, and to facilitate a better understand of the fusing process fundamentals. Third, several computer modeling codes have been evaluated as to their capabilities and accuracy in being able to capture and simulate convective mixing that may occur during PAL thermal processing. The results from these evaluation efforts are summarized in this report. The intention of this project was to extend the technology base and provide for transitioning of the arc lamp processing to the industrial Participant.

  1. Evolution of seismic velocities in heavy oil sand reservoirs during thermal recovery process

    E-Print Network [OSTI]

    Nauroy, Jean-François; Guy, N; Baroni, Axelle; Delage, Pierre; Mainguy, Marc; 10.2516/ogst/2012027

    2013-01-01

    In thermally enhanced recovery processes like cyclic steam stimulation (CSS) or steam assisted gravity drainage (SAGD), continuous steam injection entails changes in pore fluid, pore pressure and temperature in the rock reservoir, that are most often unconsolidated or weakly consolidated sandstones. This in turn increases or decreases the effective stresses and changes the elastic properties of the rocks. Thermally enhanced recovery processes give rise to complex couplings. Numerical simulations have been carried out on a case study so as to provide an estimation of the evolution of pressure, temperature, pore fluid saturation, stress and strain in any zone located around the injector and producer wells. The approach of Ciz and Shapiro (2007) - an extension of the poroelastic theory of Biot-Gassmann applied to rock filled elastic material - has been used to model the velocity dispersion in the oil sand mass under different conditions of temperature and stress. A good agreement has been found between these pre...

  2. Thermal wave image processing for characterization of subsurface of flaws in materials

    SciTech Connect (OSTI)

    Gopalan, K.; Gopalsami, N.

    1993-08-01

    Infrared images resulting from back-scattered thermal waves in composite materials are corrupted by instrument noise and sample heat-spread function. This paper demonstrates that homomorphic deconvolution and {open_quotes}demultiplication{close_quotes} result in enhanced image quality for characterization of subsurface flaws in Kevlar and graphics composites. The choice of processing depends on the material characteristics and the extent of noise in the original image.

  3. Modeling and Optimization of Direct Chill Casting to Reduce Ingot Cracking

    SciTech Connect (OSTI)

    Das, S.K.; Ningileri, S.; Long, Z.; Saito, K.; Khraisheh, M.; Hassan, M.H.; Kuwana, K.; Han, Q.; Viswanathan, S.; Sabau, A.S.; Clark, J.; Hyrn, J. (ANL)

    2006-08-15

    Approximately 68% of the aluminum produced in the United States is first cast into ingots prior to further processing into sheet, plate, extrusions, or foil. The direct chill (DC) semi-continuous casting process has been the mainstay of the aluminum industry for the production of ingots due largely to its robust nature and relative simplicity. Though the basic process of DC casting is in principle straightforward, the interaction of process parameters with heat extraction, microstructural evolution, and development of solidification stresses is too complex to analyze by intuition or practical experience. One issue in DC casting is the formation of stress cracks [1-15]. In particular, the move toward larger ingot cross-sections, the use of higher casting speeds, and an ever-increasing array of mold technologies have increased industry efficiencies but have made it more difficult to predict the occurrence of stress crack defects. The Aluminum Industry Technology Roadmap [16] has recognized the challenges inherent in the DC casting process and the control of stress cracks and selected the development of 'fundamental information on solidification of alloys to predict microstructure, surface properties, and stresses and strains' as a high-priority research need, and the 'lack of understanding of mechanisms of cracking as a function of alloy' and 'insufficient understanding of the aluminum solidification process', which is 'difficult to model', as technology barriers in aluminum casting processes. The goal of this Aluminum Industry of the Future (IOF) project was to assist the aluminum industry in reducing the incidence of stress cracks from the current level of 5% to 2%. Decreasing stress crack incidence is important for improving product quality and consistency as well as for saving resources and energy, since considerable amounts of cast metal could be saved by eliminating ingot cracking, by reducing the scalping thickness of the ingot before rolling, and by eliminating butt sawing. Full-scale industrial implementation of the results of the proposed research would lead to energy savings in excess of 6 trillion Btu by the year 2020. The research undertaken in this project aimed to achieve this objective by a collaboration of industry, university, and national laboratory personnel through Secat, Inc., a consortium of aluminum companies. During the four-year project, the industrial partners and the research team met in 16 quarterly meetings to discuss research results and research direction. The industrial partners provided guidance, facilities, and experience to the research team. The research team went to two industrial plants to measure temperature distributions in commercial 60,000-lb DC casting ingot production. The project focused on the development of a fundamental understanding of ingot cracking and detailed models of thermal conditions, solidification, microstructural evolution, and stress development during the initial transient in DC castings of the aluminum alloys 3004 and 5182. The microstructure of the DC casting ingots was systematically characterized. Carefully designed experiments were carried out at the national laboratory and university facilities as well as at the industrial locations using the industrial production facilities. The advanced computational capabilities of the national laboratories were used for thermodynamic and kinetic simulations of phase transformation, heat transfer and fluid flow, solidification, and stress-strain evolution during DC casting. The achievements of the project are the following: (1) Identified the nature of crack formation during DC casting; (2) Developed a novel method for determining the mechanical properties of an alloy at the nonequilibrium mushy zone of the alloy; (3) Measured heat transfer coefficients (HTCs) between the solidifying ingot and the cooling water jet; (4) Determined the material constitutive model at high temperatures; and (5) Developed computational capabilities for the simulation of cracking formation in DC casting ingot. The models and the database de

  4. Waste Heat Recovery and Recycling in Thermal Separation Processes: Distillation, Multi-Effect Evaporation (MEE) and Crystallization Processes

    SciTech Connect (OSTI)

    Emmanuel A. Dada; Chandrakant B. Panchal; Luke K. Achenie; Aaron Reichl; Chris C. Thomas

    2012-12-03

    Evaporation and crystallization are key thermal separation processes for concentrating and purifying inorganic and organic products with energy consumption over 1,000 trillion Btu/yr. This project focused on a challenging task of recovering low-temperature latent heat that can have a paradigm shift in the way thermal process units will be designed and operated to achieve high-energy efficiency and significantly reduce the carbon footprint as well as water footprint. Moreover, this project has evaluated the technical merits of waste-heat powered thermal heat pumps for recovery of latent heat from distillation, multi-effect evaporation (MEE), and crystallization processes and recycling into the process. The Project Team has estimated the potential energy, economics and environmental benefits with the focus on reduction in CO2 emissions that can be realized by 2020, assuming successful development and commercialization of the technology being developed. Specifically, with aggressive industry-wide applications of heat recovery and recycling with absorption heat pumps, energy savings of about 26.7 trillion Btu/yr have been estimated for distillation process. The direct environmental benefits of this project are the reduced emissions of combustible products. The estimated major reduction in environmental pollutants in the distillation processes is in CO2 emission equivalent to 3.5 billion lbs/year. Energy consumption associated with water supply and treatments can vary between 1,900 kWh and 23,700 kWh per million-gallon water depending on sources of natural waters [US DOE, 2006]. Successful implementation of this technology would significantly reduce the demand for cooling-tower waters, and thereby the use and discharge of water treatment chemicals. The Project Team has also identified and characterized working fluid pairs for the moderate-temperature heat pump. For an MEE process, the two promising fluids are LiNO3+KNO3+NANO3 (53:28:19 ) and LiNO3+KNO3+NANO2(53:35:12). And for an H2O2 distillation process, the two promising fluids are Trifluoroethanol (TFE) + Triethylene Glycol Dimethyl ether (DMETEG) and Ammonia+ Water. Thermo-physical properties calculated by Aspen+ are reasonably accurate. Documentation of the installation of pilot-plants or full commercial units were not found in the literature for validating thermo-physical properties in an operating unit. Therefore, it is essential to install a pilot-scale unit to verify thermo-physical properties of working fluid pairs and validate the overall efficiency of the thermal heat pump at temperatures typical of distillation processes. For an HO2 process, the ammonia-water heat pump system is more compact and preferable than the TFE-DMETEG heat pump. The ammonia-water heat pump is therefore recommended for the H2O2 process. Based on the complex nature of the heat recovery system, we anticipated that capital costs could make investments financially unattractive where steam costs are low, especially where co-generation is involved. We believe that the enhanced heat transfer equipment has the potential to significantly improve the performance of TEE crystallizers, independent of the absorption heat-pump recovery system. Where steam costs are high, more detailed design/cost engineering will be required to verify the economic viability of the technology. Due to the long payback period estimated for the TEE open system, further studies on the TEE system are not warranted unless there are significant future improvements to heat pump technology. For the H2O2 distillation cycle heat pump waste heat recovery system, there were no significant process constraints and the estimated 5 years payback period is encouraging. We therefore recommend further developments of application of the thermal heat pump in the H2O2 distillation process with the focus on the technical and economic viability of heat exchangers equipped with the state-of-the-art enhancements. This will require additional funding for a prototype unit to validate enhanced thermal performances of heat transfer equipment, evaluat

  5. 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.

  6. Supporting technology for enhanced oil recovery: EOR thermal processes. Seventh Amendment and Extension to Annex 4, Enhanced oil recovery thermal processes

    SciTech Connect (OSTI)

    Reid, T B [USDOE Bartlesville Project Office, OK (United States)] [USDOE Bartlesville Project Office, OK (United States); Colonomos, P [INTEVEP, Filial de Petroleos de Venezuela, SA, Caracas (Venezuela)] [INTEVEP, Filial de Petroleos de Venezuela, SA, Caracas (Venezuela)

    1993-02-01

    This report contains the results of efforts under the six tasks of the Seventh Amendment and Extension of Annex IV, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Agreement. The report is presented in sections (for each of the 6 tasks) and each section contains one or more reports prepared by various individuals or groups describing the results of efforts under each of the tasks. A statement of each task, taken from the agreement, is presented on the first page of each section. The tasks are numbered 50 through 55. The first, second, third, fourth, fifth, sixth and seventh reports on Annex IV, Venezuela MEM/USA-DOE Fossil Energy Report IV-1, IV-2, IV-3, IV-4, IV-5 and IV-6 (DOE/BETC/SP-83/15, DOE/BC-84/6/SP, DOE/BC-86/2/SP, DOE/BC-87/2/SP, DOE/BC-89/l/SP, DOE/BC-90/l/SP, and DOE/BC-92/l/SP) contain the results for the first 49 tasks. Those reports are dated April 1983, August 1984, March 1986, July 1987, November 1988, December 1989, and October 1991, respectively. Each task report has been processed separately for inclusion in the Energy Science and Technology Database.

  7. Fatigue cracking in materials with brittle surface coatings

    SciTech Connect (OSTI)

    Suresh, S.; Sugimura, Y.; Ogawa, T. (Brown Univ., Providence, RI (United States))

    1993-07-15

    Ceramic coatings enhance the resistance of metal alloys to wear, oxidation, thermal exposure, corrosion, erosion and delamination in a variety of structural, optical, electrical , electronic and bioengineering applications. Recent experimental work on steel-steel bimaterials has shown that the conditions for the growth or arrest of a fatigue crack, which approaches the interface between the two steels perpendicularly, are determined by whether the crack propagates to the interface from the weaker or the stronger material. Specifically, it is found that as the fatigue crack advances toward the interface from the weaker steel, the interaction of the crack-tip plastic zone with the interface results in the arrest of the crack. However, when the fatigue crack is propagated from the stronger to the weaker steel, crack growth occurs unimpeded through the interface. In this paper, the authors present additional experimental and mechanistic descriptions of fatigue crack growth normal to interfaces. They then apply the mechanisms underlying these experiments to the design of fatigue-resistant surface coatings for alloys. In particular, they demonstrate experimentally that a fatigue crack emanating from the brittle outercoating and advancing into the substrate can be arrested and/or deflected by proper choices of ductile interlayers. Experimental results of fatigue crack profiles and high-cycle fatigue lives are presented for two different coated materials: a steel coated with a Cr[sub 2]O[sub 3] layer and a steel coated with a Cr[sub 2]O[sub 3] outerlayer and a soft Ni-Al interlayer. The paper also includes a brief discussion of the application of proposed concepts to nitrided titanium alloys.

  8. Blunt-crack band propagation in finite-element analysis for concrete structures. [LMFBR

    SciTech Connect (OSTI)

    Pfeiffer, P.A.; Bazant, Z.P.; Marchertas, A.H.

    1983-01-01

    The knowledge of concrete fracture is needed in nuclear reactor safety. The question of safety arises from the potential of concrete to crack under thermal loading. It has been postulated that structural concrete could be exposed to very high temperature, which may result from hot reactor coolant or even core debris coming in direct contact with the concrete. The utilization of the blunt crack approach for simulating concrete cracking in a general-purpose code is explored. The difficulties encountered in establishing the proper direction of crack propagation in an arbitrary discretization are described. Crack propagation is considered within the context of two types of solution techniques: (1) implicit solution of the static crack advance, and (2) explicit time integration using a dynamic relaxation technique to simulate the static crack advance. Also, in both solution techniques an elastic model is used to characterize the concrete.

  9. Three-dimensional crack growth assessment by microtopographic examination

    SciTech Connect (OSTI)

    Lloyd, W.R.; Piascik, R.S.

    1995-12-31

    The initial stage of the stable tearing process in two 2.3 mm sheet 2024-T3 aluminum alloy M(T) specimens are analyzed using fracture surface microtopography reconstruction techniques. The local crack tip opening angles (CTOA) in the interior of the specimens are determined relative to both crack extension and through-thickness position. The microtopographic analysis of cracks grown in the L-T and T-L orientations reveal that interior CTOA is comparable to those measured on the surface using standard optical analysis methods. Similar to surface CTOA results, interior (mid-thickness) CTOA exhibit a transient behavior; CTOA transitions from high angles, at near crack initiation, to a lower steady-state value of 5 deg. and 4.2 deg. for L-T and T-L, respectively, at crack lengths greater than 1.5mm. Fracture surface topographic projection maps are used to study the evolution of crack front tunneling during the initial stage of the fracture process. Stable tearing initiates at mid-thickness followed by a crack front tunneling process to a depth of approximately 2mm. A brief discussion of the basis of the fracture process reconstruction method is provided and comments on the general utility of microtopographic fracture surface examination for general assessment of elastic-plastic and fully-plastic fracture processes are made.

  10. Dependence of dynamic fracture resistance on crack velocity in tungsten: Pt. II. Bicrystals and polycrystals

    SciTech Connect (OSTI)

    Liv, J.M.; Shen, B.W.

    1986-06-01

    The experimental techniques for crack velocity measurements have been applied to bicrystals of tungsten with twist orientations about (100) and polycrystals. The hesitation of the propagating cleavage crack in the vicinity of the grain boundary is examined. The contributions to energy dissipation from deformation and fracture processes in the grain boundary region as well as the in direct effects of crack deceleration are discussed. These findings have been applied to explain th dynamic fracture resistance and crack arrest in polycrystals.

  11. HYDRODYNAMIC THERMAL MODELING OF 9-CELL ILC CAVITY ELECTROPOLISHING AND IMPLICATIONS FOR IMPROVING THE EP PROCESS

    SciTech Connect (OSTI)

    Charles Reece; John Mammosser; Jun Ortega

    2008-02-12

    Multi-cell niobium cavities often obtain the highest performance levels after having been subjected to an electropolishing (EP) process. The horizontal EP process first developed at KEK/Nomura Plating for TRISTAN[1] cavities is being applied to TESLA-style cavities and other structures for the XFEL and ILC R&D. Jefferson Lab is presently carrying this activity in the US. Because the local electropolishing current density is highly temperature dependent, we have created using CFDesign™ a full-scale hydrodynamic model which simulates the various thermal conditions present during 9-cell cavity electropolishing. The results of these simulations are compared with exterior surface temperature data gathered during ILC cavity EP at JLab. Having benchmarked the simulation, we explore the affect of altered boundary conditions in order to evaluate potentially beneficial modifications to the current standard process.

  12. Strip edge cracking simulation in cold rolling

    SciTech Connect (OSTI)

    Hubert, C.; Dubar, L.; Dubar, M.; Dubois, A.

    2011-01-17

    This research work focuses on a specific defect which occurs during cold rolling of steel strips: edge-serration. Investigations on the industrial processes have led to the conclusion that this defect is the result of the edge-trimming and cold rolling sequences. The aim of this research work is to analyze the effect of the cutting process and the cold rolling on cracks occurrence, especially on strip edges.This study is performed using an experimental testing stand called Upsetting Rolling Test (URT). It allows to reproduce cold rolling contact parameters such as forward slip, reduction ratio and friction coefficients. Specimens sampled near trimmed industrial strip edges are deformed using the URT stand. Two sets of specimens with different stress states, obtained by annealing, are submitted to two reduction passes with extreme forward slips.Scanning electron microscopy observations added to 3D optical surface profiler topographies show that on one hand, forward slip has a major effect on cracks opening. On the other hand, cracks opening decreases according to high roll strip speed gradient. Concerning the heat-treated specimens, no crack appeared after all reduction passes, showing a large influence of the cutting process and consequently of the local stress state in the vicinity of the burnish and fracture regions.

  13. Recent Advances in SRS on Hydrogen Isotope Separation Using Thermal Cycling Absorption Process

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

    Xiao, Xin; Sessions, Henry T.; Heung, L. Kit

    2015-02-01

    The recent Thermal Cycling Absorption Process (TCAP) advances at Savannah River Site (SRS) include compressor-free concept for heating/cooling, push and pull separation using an active inverse column, and compact column design. The new developments allow significantly higher throughput and better reliability from 1/10th of the current production system’s footprint while consuming 60% less energy. Various versions are derived in the meantime for external customers to be used in fusion energy projects and medical isotope production.

  14. Modeling of crack initiation, propagation and coalescence in rocks

    E-Print Network [OSTI]

    Gonçalves da Silva, Bruno Miguel

    2009-01-01

    Natural or artificial fracturing of rock plays a very important role in geologic processes and for engineered structures in and on rock. Fracturing is associated with crack initiation, propagation and coalescence, which ...

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

    E-Print Network [OSTI]

    Brooks, Zenzile (Zenzile Z.)

    2013-01-01

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

  16. Grain-by-grain study of the mechanisms of crack propagation during iodine stress corrosion cracking of Zircaloy-4

    SciTech Connect (OSTI)

    Haddad, R.E. [CNEA, Buenos Aires (Argentina); Dorado, A.O. [CONICET, Buenos Aires (Argentina)

    1994-12-31

    This paper describes the tests conducted to determine the conditions leading to cracking of a specified grain of metal, during the iodine stress corrosion cracking (SCC) of zirconium alloys, focusing on the crystallographic orientation of crack paths, the critical stress conditions, and the significance of the fractographic features encountered. In order to perform crystalline orientation of fracture surfaces, a specially heat-treated Zircaloy-4 having very large grains, grown up to the wall thickness, was used. Careful orientation work has proved that intracrystalline pseudo-cleavage occurs only along basal planes. the effects of anisotropy, plasticity, triaxiality, and residual stresses originated in thermal contraction have to be considered to account for the influence of the stress state. A grain-by-grain calculation led to the conclusion that transgranular cracking always takes place on those bearing the maximum resolved tensile stress perpendicular to basal planes. Propagation along twin boundaries has been identified among the different fracture modes encountered.

  17. Transition from cool flame to thermal flame in compression ignition process

    SciTech Connect (OSTI)

    Yamada, Hiroyuki; Suzaki, Kotaro; Goto, Yuichi; Tezaki, Atsumu

    2008-07-15

    The mechanism that initiates thermal flames in compression ignition has been studied. Experimentally, a homogeneous charge compression ignition (HCCI) engine was used with DME, n-heptane, and n-decane. Arrhenius plots of the heat release rate in the HCCI experiments showed that rates of heat release with DME, n-heptane, and n-decane exhibited a certain activation energy that is identical to that of the H{sub 2}O{sub 2} decomposition reaction. The same feature was observed in diesel engine operation using ordinary diesel fuel with advanced ignition timing to make ignition occur after the end of fuel injection. These experimental results were reproduced in nondimensional simulations using kinetic mechanisms for DME, n-heptane, and n-decane, the last being developed by extending the n-heptane mechanism. Methanol addition, which suppresses low-temperature oxidation (LTO) and delays the ignition timing, had no effect on the activation energy obtained from the Arrhenius plot of heat release rate. Nevertheless, methanol addition lowered the heat release rates during the prethermal flame process. This is because H{sub 2}O{sub 2} formation during cool flame was reduced by adding methanol. The mechanism during the transition process from cool flame to thermal flame can be explained quantitatively using thermal explosion theory, in which the rate-determining reaction is H{sub 2}O{sub 2} decomposition, assuming that heat release in this period is caused by partial oxidation of DME and HCHO initiated with the reaction with OH produced though H{sub 2}O{sub 2} decomposition. (author)

  18. Heat-affected zone liquation crack on resistance spot welded TWIP steels

    SciTech Connect (OSTI)

    Saha, Dulal Chandra [Department of Advanced Materials Engineering, Dong-Eui University, 995 Eomgwangno, Busanjin-gu, Busan 614-714 (Korea, Republic of); Chang, InSung [Automotive Production Development Division, Hyundai Motor Company (Korea, Republic of); Park, Yeong-Do, E-mail: ypark@deu.ac.kr [Department of Advanced Materials Engineering, Dong-Eui University, 995 Eomgwangno, Busanjin-gu, Busan 614-714 (Korea, Republic of)

    2014-07-01

    In this study, the heat affected zone (HAZ) liquation crack and segregation behavior of the resistance spot welded twinning induced plasticity (TWIP) steel have been reported. Cracks appeared in the post-welded joints that originated at the partially melted zone (PMZ) and propagated from the PMZ through the heat affected zone (HAZ) to the base metal (BM). The crack length and crack opening widths were observed increasing with heat input; and the welding current was identified to be the most influencing parameter for crack formation. Cracks appeared at the PMZ when nugget diameter reached at 4.50 mm or above; and the liquation cracks were found to occur along two sides of the notch tip in the sheet direction rather than in the electrode direction. Cracks were backfilled with the liquid films which has lamellar structure and supposed to be the eutectic constituent. Co-segregation of alloy elements such as, C and Mn were detected on the liquid films by electron-probe microanalysis (EPMA) line scanning and element map which suggests that the liquid film was enrich of Mn and C. The eutectic constituent was identified by analyzing the calculated phase diagram along with thermal temperature history of finite element simulation. Preliminary experimental results showed that cracks have less/no significant effect on the static cross-tensile strength (CTS) and the tensile-shear strength (TSS). In addition, possible ways to avoid cracking were discussed. - Highlights: • The HAZ liquation crack during resistance spot welding of TWIP steel was examined. • Cracks were completely backfilled and healed with divorced eutectic secondary phase. • Co-segregation of C and Mn was detected in the cracked zone. • Heat input was the most influencing factor to initiate liquation crack. • Cracks have less/no significant effect on static tensile properties.

  19. Evaluation of gasification and novel thermal processes for the treatment of municipal solid waste

    SciTech Connect (OSTI)

    Niessen, W.R.; Marks, C.H.; Sommerlad, R.E.

    1996-08-01

    This report identifies seven developers whose gasification technologies can be used to treat the organic constituents of municipal solid waste: Energy Products of Idaho; TPS Termiska Processor AB; Proler International Corporation; Thermoselect Inc.; Battelle; Pedco Incorporated; and ThermoChem, Incorporated. Their processes recover heat directly, produce a fuel product, or produce a feedstock for chemical processes. The technologies are on the brink of commercial availability. This report evaluates, for each technology, several kinds of issues. Technical considerations were material balance, energy balance, plant thermal efficiency, and effect of feedstock contaminants. Environmental considerations were the regulatory context, and such things as composition, mass rate, and treatability of pollutants. Business issues were related to likelihood of commercialization. Finally, cost and economic issues such as capital and operating costs, and the refuse-derived fuel preparation and energy conversion costs, were considered. The final section of the report reviews and summarizes the information gathered during the study.

  20. Vaporization of actinide oxides in thermal treatment processes for mixed waste

    SciTech Connect (OSTI)

    Ebbinghaus, B.B.; Krikorian, O.H.; Adamson, M.G.

    1994-10-04

    The purpose of this study is to evaluate the volatilities of U, Pu, and Am in thermal treatment processes for mixed wastes. The thermodynamics of vaporization U and Pu oxides in the presence of oxygen and water vapor and of U oxide in the presence of oxygen and chlorine were studied. Experimental studies of U oxide volatilities by previous authors have also been reviewed. For species where data are unavailable estimation methods were used to obtain free energies of formation of the gaseous species, The data are applied to thermal treatment processes in general and then more specifically to conditions representative of the Rocky Flats Plant Fluidized Bed Unit. (RFP FBU), molten salt oxidizer, and an incinerator. U volatilities are greatest ranging from 2.67 x 10{sup -7} gU/h in the RFP FBU to 4. 00 gU/h for typical incinerator conditions. Pu volatilities are almost 5 orders of magnitude less than U and Am volatilities are about 3 orders of magnitude less than Pu.

  1. Cracks in Martensite Plates as Hydrogen Traps in a Bearing Steel

    E-Print Network [OSTI]

    Solano-Alvarez, W.; Song, Eun Ju; Han, Do Kyeong; Suh, Dong-Woo; Bhadeshia, H. K. D. H.

    2014-12-03

    It is demonstrated that a macroscopically homogeneous distribution of tiny cracks introduced into a martensitic bearing steel sample can provide powerful hydrogen traps. The phenomenon has been investigated through thermal desorption spectroscopy...

  2. Crack-resistant siloxane molding compounds. [Patent application

    DOE Patents [OSTI]

    McFarland, J.W.; Swearngin, C.B.

    1980-11-03

    The crack resistance of phenyl silicone molding resins containing siliceous fillers is improved by incorporating therein about 0.5 to 5.5% by weight of ..beta..-eucryptite, a lithium aluminum silicate having a negative thermal expansion coefficient. These molding resins are particularly suitable for encapsulating electronic devices such as diodes, coils, resistors, and the like.

  3. Thermal plasma processed ferro-magnetically ordered face-centered cubic iron at room temperature

    SciTech Connect (OSTI)

    Raut, Suyog A.; Kanhe, Nilesh S.; Bhoraskar, S. V.; Mathe, V. L.; Das, A. K.

    2014-10-28

    Here, we report tailor made phase of iron nanoparticles using homogeneous gas phase condensation process via thermal plasma route. It was observed that crystal lattice of nano-crystalline iron changes as a function of operating parameters of the plasma reactor. In the present investigation iron nanoparticles have been synthesized in presence of argon at operating pressures of 125–1000?Torr and fixed plasma input DC power of 6?kW. It was possible to obtain pure fcc, pure bcc as well as the mixed phases for iron nanoparticles in powder form as a function of operating pressure. The as synthesized product was characterized for understanding the structural and magnetic properties by using X-ray diffraction, vibrating sample magnetometer, and Mössbauer spectroscopy. The data reveal that fcc phase is ferromagnetically ordered with high spin state, which is unusual whereas bcc phase is found to be ferromagnetic as usual. Finally, the structural and magnetic properties are co-related.

  4. Thermal casting process for the preparation of anisotropic membranes and the resultant membrane

    DOE Patents [OSTI]

    Caneba, Gerard T. M. (Albany, CA); Soong, David S. (Albany, CA)

    1987-01-01

    A method for providing anisotropic polymer membranes from a binary polymer/solvent solution using a thermal inversion process. A homogeneous binary solution is cast onto a support and cooled in such a way as to provide a differential in cooling rate across the thickness of the resulting membrane sheet. Isotropic or anisotropic structures of selected porosities can be produced, depending on the initial concentration of polymer in the selected solvent and on the extent of the differential in cooling rate. This differential results in a corresponding gradation in pore size. The method may be modified to provide a working skin by applying a rapid, high-temperature pulse to redissolve a predetermined thickness of the membrane at one of its faces and then freezing the entire structure.

  5. A study of the ignition processes in a center-hole-fired thermal battery

    SciTech Connect (OSTI)

    Guidotti, R.A.; Reinhardt, F.W.

    1998-04-01

    The ignition processes that take place during activation of a 16 cell, center hole fired thermal battery were examined by monitoring the voltage of each cell during activation. The average rise time of each cell to a voltage of 1.125 V was determined for the LiSi/LiCl-LiBr-LiF/FeS{sub 2} electrochemical system. The effects of heat pellet composition, center hole diameter, and the load on the activation parameters were examined for three different igniters. A large variability in individual cell performance was evident along with cell reversal, depending on the location of the cell in the stack. It was not possible to draw detailed statistical information of the relative ignition sequence due to the intrinsic large scatter in the data.

  6. Improvement of thermal properties of low-rank coals treated by hydrothermal process

    SciTech Connect (OSTI)

    Xie, X.F.; Ohki, A.; Maeda, S.

    1999-07-01

    Australian low-rank coals, Loy Yang coal, Yallourn coal and Indonesian Adaro coal are hydrothermally treated at 200-350 C. The simultaneous TG/DTA is used to investigate the thermal properties, which include the volatile release profile under a nitrogen atmosphere and the burning profile under an air atmosphere. It is found that the temperature of volatile matter combustion (Ti1) of the hot water dried coals (upgraded coals) increases with heat treatment temperature (HTT), whereas the temperature of char combustion (Ti2), the temperature of maximum reaction (Tmax) and the temperature of char burn out (Tout) do not have large increase on the HTT. These results suggest that the HWD process can raise the volatile matter ignition temperature, resulting in improving the spontaneous ignition temperature, but it still maintains the original combustion behavior. Results from TG-DTA measurements are consistent with those determined by FTIR and solid state {sup 13}C CP/MAS NMR.

  7. Yellowstone as an Analog for Thermal-Hydrological-Chemical Processes at Yucca Mountain

    SciTech Connect (OSTI)

    P. F. Dobson; T. J. Kneafsey; A. Simmons; J. Hulen

    2001-05-29

    Enhanced water-rock interaction resulting from the emplacement of heat-generating nuclear waste in the potential geologic repository at Yucca Mountain, Nevada, may result in changes to fluid flow (resulting from mineral dissolution and precipitation in condensation and boiling zones, respectively). Studies of water-rock interaction in active and fossil geothermal systems (natural analogs) provide evidence for changes in permeability and porosity resulting from thermal-hydrological-chemical (THC) processes. The objective of this research is to document the effects of coupled THC processes at Yellowstone and then examine how differences in scale could influence the impact that these processes may have on the Yucca Mountain system. Subsurface samples from Yellowstone National Park, one of the largest active geothermal systems in the world, contain some the best examples of hydrothermal self-sealing found in geothermal systems. We selected core samples from two USGS research drill holes from the transition zone between conductive and convective portions of the geothermal system (where sealing was reported to occur). We analyzed the core, measuring the permeability, porosity, and grain density of selected samples to evaluate how lithology, texture, and degree of hydrothermal alteration influence matrix and fracture permeability.

  8. Solar thermal hydrogen production process: Final report, January 1978-December 1982

    SciTech Connect (OSTI)

    Not Available

    1982-12-01

    Under sponsorship by the United States Department of Energy, Westinghouse Advanced Energy-Systems Division has investigated the potential for using solar thermal energy to split water into hydrogen and oxygen. A hybrid thermochemical/electrochemical process, known as the Sulfur Cycle, has been the focus of these investigations. Process studies have indicated that, with adequate and ongoing research and development, the Sulfur Cycle can be effectively driven with solar heat. Also, economic analyses have indicated that the cycle has the potential to produce hydrogen in economic competitiveness with conventional methods (e.g. methane/steam reforming) by the turn of the century. A first generation developmental system has been defined along with its critical components, i.e. those components that need substantial engineering development. Designs for those high temperature components that concentrate, vaporize and decompose the process circulating fluid, sulfuric acid, have been prepared. Extensive experimental investigations have been conducted with regard to the selection of construction materials for these components. From these experiments, which included materials endurance tests for corrosion resistance for periods up to 6000 hours, promising materials and catalysts have been identified.

  9. Structures for dense, crack free thin films

    DOE Patents [OSTI]

    Jacobson, Craig P. (Lafayette, CA); Visco, Steven J. (Berkeley, CA); De Jonghe, Lutgard C. (Lafayette, CA)

    2011-03-08

    The process described herein provides a simple and cost effective method for making crack free, high density thin ceramic film. The steps involve depositing a layer of a ceramic material on a porous or dense substrate. The deposited layer is compacted and then the resultant laminate is sintered to achieve a higher density than would have been possible without the pre-firing compaction step.

  10. The cracking and spalling of multilayered chromium coatings

    SciTech Connect (OSTI)

    Joergensen, O.; Horsewell, A.; Soerensen, B.F. [Risoe National Lab., Roskilde (Denmark). Materials Dept.] [Risoe National Lab., Roskilde (Denmark). Materials Dept.; Leisner, P. [Technical Univ. of Denmark, Lyngby (Denmark). Centre of Advanced Electroplating] [Technical Univ. of Denmark, Lyngby (Denmark). Centre of Advanced Electroplating

    1995-11-01

    Cracks in a chromium coating on a steel substrate which are caused by residual stresses developed during an electroplating process are examined. The chromium coating, formed as a multilayer by alternating electroplating utilizing direct current (DC) and periodic current reversal (PR), is in a state of biaxial tensile stress due to a volume contraction in the successive DC layers which occurs during deposition. A uniform biaxial misfit strain idealizes this layerwise contraction. The state of stress in the multilayer is model during laminate theory. Special emphasis is given to the influence of the substrate flexibility on the stress build-up. It is shown that the flexibility of the substrate produces an equal biaxial bending moment in the coating. At a critical coating thickness, the chromium multilayer cracks and spalls off the substrate. The radius of curvature of detached coating fragments provides a measure of the size of the bending moment and, indirectly, of the misfit strain. The observed fracture mechanism is qualitatively divided into cracks channeling in the coating and debonding cracks running in the interface between the coating and the substrate. Long crack asymptotic solutions for the two distinct crack types are presented. The fracture analyses of the multilayered chromium coating show the functional dependence of relative layer and substrate thicknesses and flexibility on the energy release rate for crack propagation.

  11. Standard test method for creep-fatigue crack growth testing

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2010-01-01

    1.1 This test method covers the determination of creep-fatigue crack growth properties of nominally homogeneous materials by use of pre-cracked compact type, C(T), test specimens subjected to uniaxial cyclic forces. It concerns fatigue cycling with sufficiently long loading/unloading rates or hold-times, or both, to cause creep deformation at the crack tip and the creep deformation be responsible for enhanced crack growth per loading cycle. It is intended as a guide for creep-fatigue testing performed in support of such activities as materials research and development, mechanical design, process and quality control, product performance, and failure analysis. Therefore, this method requires testing of at least two specimens that yield overlapping crack growth rate data. The cyclic conditions responsible for creep-fatigue deformation and enhanced crack growth vary with material and with temperature for a given material. The effects of environment such as time-dependent oxidation in enhancing the crack growth ra...

  12. Automated Thermal Image Processing for Detection and Classification of Birds and Bats - FY2012 Annual Report

    SciTech Connect (OSTI)

    Duberstein, Corey A.; Matzner, Shari; Cullinan, Valerie I.; Virden, Daniel J.; Myers, Joshua R.; Maxwell, Adam R.

    2012-09-01

    Surveying wildlife at risk from offshore wind energy development is difficult and expensive. Infrared video can be used to record birds and bats that pass through the camera view, but it is also time consuming and expensive to review video and determine what was recorded. We proposed to conduct algorithm and software development to identify and to differentiate thermally detected targets of interest that would allow automated processing of thermal image data to enumerate birds, bats, and insects. During FY2012 we developed computer code within MATLAB to identify objects recorded in video and extract attribute information that describes the objects recorded. We tested the efficiency of track identification using observer-based counts of tracks within segments of sample video. We examined object attributes, modeled the effects of random variability on attributes, and produced data smoothing techniques to limit random variation within attribute data. We also began drafting and testing methodology to identify objects recorded on video. We also recorded approximately 10 hours of infrared video of various marine birds, passerine birds, and bats near the Pacific Northwest National Laboratory (PNNL) Marine Sciences Laboratory (MSL) at Sequim, Washington. A total of 6 hours of bird video was captured overlooking Sequim Bay over a series of weeks. An additional 2 hours of video of birds was also captured during two weeks overlooking Dungeness Bay within the Strait of Juan de Fuca. Bats and passerine birds (swallows) were also recorded at dusk on the MSL campus during nine evenings. An observer noted the identity of objects viewed through the camera concurrently with recording. These video files will provide the information necessary to produce and test software developed during FY2013. The annotation will also form the basis for creation of a method to reliably identify recorded objects.

  13. An investigation of crack-tip stress field criteria of predicting cleavage-crack initiation

    SciTech Connect (OSTI)

    Keeney-Walker, J.; Bass, B.R.; Landes, J.D. (Oak Ridge National Lab., TN (United States))

    1991-09-01

    Cleavage-crack initiation in large-scale wide-plate (WP) specimens could not be accurately predicted from small, compact (CT) specimens by using a linear-elastic fracture-mechanics, K{sub Ic}, methodology. In the wide-plate tests conducted by the Heavy-Section Steel Technology Program at Oak Ridge National Laboratory, crack initiation has consistently occurred at stress-intensity (K{sub I}) values ranging from two to four times those predicted by the CT specimens. Studies were initiated to develop crack-tip stress field criteria incorporating effects of geometry, size, and constraint that will lead to improved predictions of cleavage initiation in WP specimens from CT specimens. The work centers around nonlinear two-and three-dimensional finite-element analyses of the crack-tip stress fields in these geometries. Analyses were conducted on CT and WP specimens for which cleavage initiation fracture had been measured in laboratory tests. The local crack-tip field generated for these specimens were then used in the evaluation of fracture correlation parameters to augment the K{sub I} parameter for predicting cleavage initiation. Parameters of hydrostatic constraint and of maximum principal stress, measured volumetrically, are included in these evaluations. The results suggest that the cleavage initiation process can be correlated with the local crack-tip fields via a maximum principal stress criterion based on achieving a critical area within a critical stress contour. This criterion has been successfully applied to correlate cleavage initiation in 2T-CT and WP specimen geometries. 23 refs., 16 figs., 5 tabs.

  14. Rejuvenation and reuse of spent fluid cracking catalysts

    SciTech Connect (OSTI)

    Elvin, F.J. (ChemCat Corp., New Orleans, LA (US))

    1988-01-01

    Refineries processing heavy, high metals feedstocks have reused other refineries' spent cracking catalyst for the past ten years without observing any yield debits. ChemCat has developed a process whereby a refinery can reuse its own spent catalyst without suffering any yield debits. The new DEMET process is being demonstrated in the world's first commercial fluid cracking catalyst rejuvenation and demetallization plant. The plant is located in Meraux, Louisiana and processes 20 tons/day of spent cracking catalyst for local refineries. The plant removes contaminant metals from zeolite catalysts, while simultaneously increasingly the zeolite and matrix surface areas. The demetallized catalyst has a higher activity and better selectivity than the undemetallized spent catalyst. The demetallized catalyst is also more hydrothermally stable than the spent catalyst. ChemCat's DEMET process enables refiners to eliminate the high cost of spent FCCU catalyst disposal and to significantly reduce their consumption and cost of fresh catalyst.

  15. Proceedings of the NSF Workshop on Research Needs in Thermal Aspects of Material Removal Processes, edited Ranga Komanduri, Oklahoma State University, Stillwater, OK, June 10-12, 2003

    E-Print Network [OSTI]

    Yao, Y. Lawrence

    Proceedings of the NSF Workshop on Research Needs in Thermal Aspects of Material Removal Processes laser energy has enough time to be transferred to lattice, electron and lattice can reach thermal, edited Ranga Komanduri, Oklahoma State University, Stillwater, OK, June 10-12, 2003 247 Thermal Aspects

  16. Characterization of oxygen and nitrogen rapid thermal annealing processes for ultra-low-k SiCOH films

    E-Print Network [OSTI]

    Boo, Jin-Hyo

    Characterization of oxygen and nitrogen rapid thermal annealing processes for ultra-low-k Si is suggested and characterized in this work for improvement of SiCOH ultra-low-k (k 2.4) film properties. Low is decreased, and the ultra-low-k films (k

  17. Modeling of thermally driven hydrological processes in partially saturated fractured rock

    E-Print Network [OSTI]

    Tsang, Yvonne

    2010-01-01

    Waste isolation Pilot Plant (WIPP) research and developmentIsolation Pilot Plant (WIPP) Thermal/Structural InteractionWaste Isolation Pilot Plant (WIPP) Project in New Mexico,

  18. Supporting Technology for Enhanced Oil Recovery-EOR Thermal Processes Report IV-12

    SciTech Connect (OSTI)

    Izequeido, Alexandor

    2001-04-01

    This report contains the results of efforts under the six tasks of the Ninth Amendment and Extension of Annex IV, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Agreement. The report is presented in sections (for each of the 6 tasks) and each section contains one or more reports prepared by various individuals or groups describing the results of efforts under each of the tasks. A statement of each task, taken from the agreement, is presented on the first page of each section. The tasks are numbered 62 through 67. The first, second, third, fourth, fifth, sixth, seventh, eight, and ninth reports on Annex IV, [Venezuela MEM/USA-DOE Fossil Energy Report IV-1, IV-2, IV-3, IV-4, IV-5, IV-6, IV-7, and IV-8 (DOE/BETC/SP-83/15, DOE/BC-84/6/SP, DOE/BC-86/2/SP, DOE/BC-87/2/SP, DOE/BC-89/1/SP, DOE/BC-90/1/SP) DOE/BC-92/1/SP, DOE/BC-93/3/SP, and DOE/BC-95/3/SP] contain the results from the first 61 tasks. Those reports are dated April 1983, August 1984, March 1986, July 1! 987, November 1988, December 1989, October 1991, February 1993, and March 1995 respectively.

  19. Peridynamic model for fatigue cracking.

    SciTech Connect (OSTI)

    Silling, Stewart A.; Abe Askari

    2014-10-01

    The peridynamic theory is an extension of traditional solid mechanics in which the field equations can be applied on discontinuities, such as growing cracks. This paper proposes a bond damage model within peridynamics to treat the nucleation and growth of cracks due to cyclic loading. Bond damage occurs according to the evolution of a variable called the %22remaining life%22 of each bond that changes over time according to the cyclic strain in the bond. It is shown that the model reproduces the main features of S-N data for typical materials and also reproduces the Paris law for fatigue crack growth. Extensions of the model account for the effects of loading spectrum, fatigue limit, and variable load ratio. A three-dimensional example illustrates the nucleation and growth of a helical fatigue crack in the torsion of an aluminum alloy rod.

  20. Observation of an incoherent thermally activated proton hopping process in calix-[4]-arene by means of anelastic spectroscopy

    E-Print Network [OSTI]

    A. Paolone; R. Cantelli; R. Caciuffo; A. Arduini

    2002-03-04

    The anelastic spectrum of calix[4]arene was measured at two different vibrational frequencies. Three thermally activated peaks were detected. The lowest temperature peak can be described considering a continous distribution function of activation energies for the relaxation. This anelastic peak can be ascribed to a thermally activated hopping process of H atoms of the OH groups, corresponding to a flip-flop of the OH bond. From the results of the present study, it seems that anelastic spectroscopy is a good experimental technique to study atomic motion inside molecules at a mesoscopic (few molecules) level.

  1. On the thermal neutron transport processes in liquid H/sub 2/O-D/sub 2/O mixtures

    SciTech Connect (OSTI)

    Barnsal, R.M.; Tewari, S.P.

    1983-06-01

    Using the recently developed thermal neutron scattering kernels for water and heavy water, which incorporate both the collective and the molecular modes present in water and heavy water, the thermal neutron transport studies of asymptotic decay constants lambda/sub 0/, diffusion coefficient D/sub 0/, diffusion cooling coefficient C, and the transport mean-free-path lambda /SUB tr/ are studied for liquid H/sub 2/O-D/sub 2/O mixtures with varying molecular contents and for various assembly sizes at 21 and 5/sup 0/C. The calculated values of the physical constants, lambda/sub 0/, D/sub 0/, C, and lambda /SUB tr/ are found to be in good agreement with the corresponding experimental results. Both the collective motion and the molecular modes present in the liquid H/sub 2/O-D/sub 2/O mixtures play significant roles in the thermal neutron transport processes.

  2. Thermal spray vitrification process for the removal of lead oxide contained in organic paints

    SciTech Connect (OSTI)

    Karthikeyan, J.; Chen, J.; Bancke, G.A.; Herman, H.; Berndt, C.C.; Breslin, V.T.

    1995-12-31

    The US Environmental Protection Agency (US-EPA) regulations have necessitated the removal and containment of toxic lead from lead oxide containing paints. The Thermal Spray Vitrification Process (TSVP) is a novel technique in which a glass powder of appropriate composition is flame sprayed onto the painted surface to achieve removal and vitrification of the lead. Two different glass systems, i.e., alkali silicate and ferrous silicate, were chosen for detailed study. Appropriate amounts of raw materials were mixed, fused, quenched, ground and sieved to obtain the spray quality powders. Grit blasted mild steel coupons were used as test substrates for the spray parameter optimization studies; while those coupons with lead oxide containing organic paint were used for the lead removal experiments. The powders and deposits were investigated using Microtrac particle size analysis (for powders), optical microscopy, XRD and SEM. The remnant lead in the panel was measured using a specially prepared X-Ray Fluorescence (XRF) system. The lead leach rate was recorded as per US-EPA approved Toxicity Characteristic Leaching Procedure (TCLP). The results of this study have shown that lead oxide can be successfully removed form the paint by flame spraying a maximum of three layers of glass onto the painted surface. It is possible to obtain much higher lead removal rate with ferrous silicate glass as compared to alkali silicate glass is much higher than the ferrous silicate glass. The in situ vitrification has not been completely optimized; however, the lead containing glass coating can be remelted in situ or on site to enhance the vitrification of the lead which had been absorbed in the glass coating.

  3. Study on Commissioning Process for Control Logic of Thermal Storage System 

    E-Print Network [OSTI]

    Shioya, M.; Tsubaki, M.; Nakahara, N.

    2004-01-01

    and measurements of the control output, the CLT can detect faults relating to operation. The present paper reports the result of commissioning of a heat exchanger secondary control in a thermal storage system in an actual building using the CLT....

  4. Weld solidification cracking in 304 to 204L stainless steel

    SciTech Connect (OSTI)

    Hochanadel, Patrick W [Los Alamos National Laboratory; Lienert, Thomas J [Los Alamos National Laboratory; Martinez, Jesse N [Los Alamos National Laboratory; Johnson, Matthew Q [Los Alamos National Laboratory

    2010-09-15

    A series of annulus welds were made between 304 and 304L stainless steel coaxial tubes using both pulsed laser beam welding (LBW) and pulsed gas tungsten arc welding (GTAW). In this application, a change in process from pulsed LBW to pulsed gas tungsten arc welding was proposed to limit the possibility of weld solidification cracking since weldability diagrams developed for GTAW display a greater range of compositions that are not crack susceptible relative to those developed for pulsed LBW. Contrary to the predictions of the GTAW weldability diagram, cracking was found.This result was rationalized in terms of the more rapid solidification rate of the pulsed gas tungsten arc welds. In addition, for the pulsed LBW conditions, the material compositions were predicted to be, by themselves, 'weldable' according to the pulsed LBW weldability diagram. However, the composition range along the tie line connecting the two compositions passed through the crack susceptible range. Microstructurally, the primary solidification mode (PSM) of the material processed with higher power LBW was determined to be austenite (A), while solidification mode of the materials processed with lower power LBW apparently exhibited a dual PSM of both austenite (A) and ferrite-austenite (FA) within the same weld. The materials processed by pulsed GTAW showed mostly primary austenite solidification, with some regions of either primary austenite-second phase ferrite (AF) solidification or primary ferrite-second phase austenite (FA) solidification. This work demonstrates that variations in crack susceptibility may be realized when welding different heats of 'weldable' materials together, and that slight variations in processing can also contribute to crack susceptibility.

  5. Weld solidification cracking in 304 to 304L stainless steel

    SciTech Connect (OSTI)

    Hochanadel, Patrick W [Los Alamos National Laboratory; Lienert, Thomas J [Los Alamos National Laboratory; Martinez, Jesse N [Los Alamos National Laboratory; Martinez, Raymond J [Los Alamos National Laboratory; Johnson, Matthew Q [Los Alamos National Laboratory

    2010-01-01

    A series of annulus welds were made between 304 and 304L stainless steel coaxial tubes using both pulsed laser beam welding (LBW) and pulsed gas tungsten arc welding (GTAW). In this application, a change in process from pulsed LBW to pulsed gas tungsten arc welding was proposed to limit the possibility of weld solidification cracking since weldability diagrams developed for GTAW display a greater range of compositions that are not crack susceptible relative to those developed for pulsed LBW. Contrary to the predictions of the GTAW weldability diagram, cracking was found. This result was rationalized in terms of the more rapid solidification rate of the pulsed gas tungsten arc welds. In addition, for the pulsed LBW conditions, the material compositions were predicted to be, by themselves, 'weldable' according to the pulsed LBW weldability diagram. However, the composition range along the tie line connecting the two compositions passed through the crack susceptible range. Microstructurally, the primary solidification mode (PSM) of the material processed with higher power LBW was determined to be austenite (A), while solidification mode of the materials processed with lower power LBW apparently exhibited a dual PSM of both austenite (A) and ferrite-austenite (FA) within the same weld. The materials processed by pulsed GT A W showed mostly primary austenite solidification, with some regions of either primary austenite-second phase ferrite (AF) solidification or primary ferrite-second phase austenite (FA) solidification. This work demonstrates that variations in crack susceptibility may be realized when welding different heats of 'weldable' materials together, and that slight variations in processing can also contribute to crack susceptibility.

  6. Method for fabrication of crack-free ceramic dielectric films

    DOE Patents [OSTI]

    Ma, Beihai; Balachandran, Uthamalingam; Chao, Sheng; Liu, Shanshan; Narayanan, Manoj

    2014-02-11

    The invention provides a process for forming crack-free dielectric films on a substrate. The process comprise the application of a dielectric precursor layer of a thickness from about 0.3 .mu.m to about 1.0 .mu.m to a substrate. The deposition is followed by low temperature heat pretreatment, prepyrolysis, pyrolysis and crystallization step for each layer. The deposition, heat pretreatment, prepyrolysis, pyrolysis and crystallization are repeated until the dielectric film forms an overall thickness of from about 1.5 .mu.m to about 20.0 .mu.m and providing a final crystallization treatment to form a thick dielectric film. Also provided was a thick crack-free dielectric film on a substrate, the dielectric forming a dense thick crack-free dielectric having an overall dielectric thickness of from about 1.5 .mu.m to about 20.0 .mu.m.

  7. EFFECT OF THERMAL PROCESSES ON COPPER-TIN ALLOYS FOR ZINC GETTERING

    SciTech Connect (OSTI)

    Korinko, P.; Golyski, M.

    2013-11-01

    A contamination mitigation plan was initiated to address the discovery of radioactive zinc‐65 in a glovebox. A near term solution was developed, installation of heated filters in the glovebox piping. This solution is effective at retaining the zinc in the currently contaminated area, but the gamma emitting contaminant is still present in a system designed for tritium beta. A project was initiated to develop a solution to contain the {sup 65}Zn in the furnace module. Copper and bronze (a Cu/Sn alloy) were found to be candidate materials to combine with zinc‐65 vapor, using thermodynamic calculations. A series of binary Cu/Sn alloys were developed (after determining that commercial alloys were unacceptable), that were found to be effective traps of zinc vapor. The task described in this report was undertaken to determine if the bronze substrates would retain their zinc gettering capability after being exposed to simulated extraction conditions with oxidizing and reducing gases. Pure copper and three bronze alloys were prepared, exposed to varying oxidation conditions from 250 to 450{degree}C, then exposed to varying reduction conditions in He-H{sub 2} from 250-450{degree}C, and finally exposed to zinc vapor at 350{degree}C for four hours. The samples were characterized using scanning electron microscopy, X-ray diffraction, differential thermal analysis, mass change, and visual observation. It was observed that the as fabricated samples and the reduced samples all retained their zinc gettering capacity while samples in the "as-oxidized" condition exhibited losses in zinc gettering capacity. Over the range of conditions tested, i.e., composition, oxidation temperature, and reduction temperature, no particular sample composition appeared better. Samples reduced at 350{degree}C exhibited the greatest zinc capacity, although there were some testing anomalies associated with these samples. This work clearly demonstrated that the zinc gettering was not adversely affected by exposure to simulated process conditions and a full scale lithium and zinc trap should be fabricated for testing in the Tritium Extraction Facility.

  8. Modelling the microstructure of thermal barrier coatings

    SciTech Connect (OSTI)

    Cirolini, S.; Marchese, M.; Jacucci, G.; Harding, J.H.; Mulheran, P.A.

    1994-12-31

    Thermal barrier coatings produced by plasma spraying have a characteristic microstructure of lamellae, pores and cracks. The lamellae are produced by the splashing of particles onto the substrate. As the coating grows, the lamellae pile on top of each other, producing an interlocking structure. In most cases the growth is rapid and chaotic. The result is a microstructure characterized by pores and cracks. The authors present an improved model for the deposition process of thermal barrier coatings. The task of modeling the coating growth is split into two parts: first the authors consider a description of the particle on arrival at the film, based on the available theoretical, numerical and experimental findings. Second they define and discuss a set of physically-based rules for combining these events to obtain the film. The splats run along the surface and are permitted to curl up (producing pores) or interlock. The computer model uses a mesh to combine these processes and build the coating. They discuss the use of the proposed model in predicting microstructures and hence in correlating the properties of these coatings with the parameters of the process used to make them.

  9. Non-hypersingular boundary integral equations for 3-D non-planar crack dynamics

    E-Print Network [OSTI]

    Madariaga, RaĂşl

    Non-hypersingular boundary integral equations for 3-D non-planar crack dynamics T. Tada, E, are removed by way of a technique of regu- larization based on integration by parts. The variables are denoted, in time and space, of the slip along the crack and a set of integration kernels. Then a limiting process

  10. Thermal imaging measurement of lateral diffusivity and non-invasive material defect detection

    DOE Patents [OSTI]

    Sun, Jiangang (Westmont, IL); Deemer, Chris (Downers Grove, IL)

    2003-01-01

    A system and method for determining lateral thermal diffusivity of a material sample using a heat pulse; a sample oriented within an orthogonal coordinate system; an infrared camera; and a computer that has a digital frame grabber, and data acquisition and processing software. The mathematical model used within the data processing software is capable of determining the lateral thermal diffusivity of a sample of finite boundaries. The system and method may also be used as a nondestructive method for detecting and locating cracks within the material sample.

  11. The origin of thermal component in the transverse momentum spectra in high energy hadronic processes

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

    Bylinkin, Alexander A.; Inst. of Theoretical and Experimental Physics; Kharzeev, Dmitri E.; Brookhaven National Lab.; Rostovtsev, Andrei A.

    2014-12-15

    The transverse momentum spectra of hadrons produced in high energy collisions can be decomposed into two components: the exponential ("thermal") and the power ("hard") ones. Recently, the H1 Collaboration has discovered that the relative strength of these two components in Deep Inelastic Scattering (DIS) depends drastically upon the global structure of the event - namely, the exponential component is absent in the diffractive events characterized by a rapidity gap. We discuss the possible origin of this effect and speculate that it is linked to confinement. Specifically, we argue that the thermal component is due to the effective event horizon introducedmore »by the confining string, in analogy to the Hawking-Unruh effect. In diffractive events, the t-channel exchange is color-singlet and there is no fragmenting string - so the thermal component is absent. The slope of the soft component of the hadron spectrum in this picture is determined by the saturation momentum that drives the deceleration in the color field, and thus the Hawking-Unruh temperature. We analyze the data on non-diffractive pp collisions and find that the slope of the thermal component of the hadron spectrum is indeed proportional to the saturation momentum.« less

  12. Enhancement of thermal and electrical properties of carbon nanotube polymer composites by magnetic field processing

    E-Print Network [OSTI]

    Garmestani, Hamid

    Enhancement of thermal and electrical properties of carbon nanotube polymer composites by magnetic and electrical properties of single wall carbon nanotube CNT -polymer composites are significantly enhanced. INTRODUCTION The addition of small quantities of carbon nanotubes CNTs to polymer composites is known to cause

  13. The origin of thermal component in the transverse momentum spectra in high energy hadronic processes

    E-Print Network [OSTI]

    Alexander A. Bylinkin; Dmitri E. Kharzeev; Andrei A. Rostovtsev

    2014-07-15

    The transverse momentum spectra of hadrons produced in high energy collisions can be decomposed into two components: the exponential ("thermal") and the power ("hard") ones. Recently, the H1 Collaboration has discovered that the relative strength of these two components in Deep Inelastic Scattering depends drastically upon the global structure of the event - namely, the exponential component is absent in the diffractive events characterized by a rapidity gap. We discuss the possible origin of this effect, and speculate that it is linked to confinement. Specifically, we argue that the thermal component is due to the effective event horizon introduced by the confining string, in analogy to the Hawking-Unruh effect. In diffractive events, the $t$-channel exchange is color-singlet and there is no fragmenting string -- so the thermal component is absent. The slope of the soft component of the hadron spectrum in this picture is determined by the saturation momentum that drives the deceleration in the color field, and thus the Hawking-Unruh temperature. We analyze the data on non-diffractive $pp$ collisions and find that the slope of the thermal component of the hadron spectrum is indeed proportional to the saturation momentum.

  14. The origin of thermal component in the transverse momentum spectra in high energy hadronic processes

    SciTech Connect (OSTI)

    Bylinkin, Alexander A.; Kharzeev, Dmitri E.; Rostovtsev, Andrei A.

    2014-12-15

    The transverse momentum spectra of hadrons produced in high energy collisions can be decomposed into two components: the exponential ("thermal") and the power ("hard") ones. Recently, the H1 Collaboration has discovered that the relative strength of these two components in Deep Inelastic Scattering (DIS) depends drastically upon the global structure of the event - namely, the exponential component is absent in the diffractive events characterized by a rapidity gap. We discuss the possible origin of this effect and speculate that it is linked to confinement. Specifically, we argue that the thermal component is due to the effective event horizon introduced by the confining string, in analogy to the Hawking-Unruh effect. In diffractive events, the t-channel exchange is color-singlet and there is no fragmenting string - so the thermal component is absent. The slope of the soft component of the hadron spectrum in this picture is determined by the saturation momentum that drives the deceleration in the color field, and thus the Hawking-Unruh temperature. We analyze the data on non-diffractive pp collisions and find that the slope of the thermal component of the hadron spectrum is indeed proportional to the saturation momentum.

  15. Degradation of Structural Alloys Under Thermal Insulation 

    E-Print Network [OSTI]

    McIntyre, D. R.

    1984-01-01

    Wet thermal insulation may actively degrade steel and stainless steel structures by general corrosion or stress-corrosion cracking. Two different mechanisms of water ingress into insulation are discussed; flooding from external sources...

  16. Cracking in reinforced concrete bent caps 

    E-Print Network [OSTI]

    Young, Bradley S.

    2000-01-01

    cracking in order to improve durability and reduce maintenance costs of bent caps throughout the lifetime of the structure. Excessive cracking in RC bent caps can be controlled through improved design detailing for both flexure and shear. For flexure...

  17. Three-dimensional EBSD characterization of thermo-mechanical fatigue crack morphology in compacted graphite iron

    SciTech Connect (OSTI)

    Pirgazi, Hadi, E-mail: Hadi.pirgazi@ugent.be [Department of Materials Science and Engineering, Ghent University, Technologiepark 903, 9052 Gent (Belgium); Ghodrat, Sepideh, E-mail: s.ghodrat@tudelft.nl [Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD, Delft (Netherlands); Kestens, Leo A.I., E-mail: leo.kestens@ugent.be [Department of Materials Science and Engineering, Ghent University, Technologiepark 903, 9052 Gent (Belgium); Department of Materials Science and Engineering, Delft University of Technology, Mekelweg 2, 2628 CD, Delft (Netherlands)

    2014-04-01

    In cylinder heads made of compacted graphitic iron (CGI), heating and cooling cycles can lead to localized cracking due to thermo-mechanical fatigue (TMF). To meticulously characterize the complex crack path morphology of CGI under TMF condition, in relation to microstructural features and to find out how and by which mechanisms the cracks predominantly develop, three-dimensional electron back scattering diffraction (EBSD) was employed. Based on the precise quantitative microstructural analysis, it is found that graphite particles not only play a crucial role in the crack initiation, but also are of primary significance for crack propagation, i.e. crack growth is enhanced by the presence of graphite particles. Furthermore, the density of graphite particles on the fracture plane is more than double as high as in any other arbitrary plane of the structure. The obtained results did not indicate a particular crystallographic preference of fracture plane, i.e. the crystal plane parallel to the fracture plane was nearly of random orientation. - Highlights: • Crystallographic features of a thermo-mechanical fatigue (TMF) crack were studied. • Wide-field 3D EBSD is used to characterize the TMF crack morphology. • Data processing was applied on a large length scale of the order of millimeters. • Graphite density in the fracture plane is much higher than any other random plane. • It is revealed that crack growth is enhanced by the presence of graphite particles.

  18. Innovative Approach to Establish Root Causes for Cracking in Aggressive Reactor Environments

    SciTech Connect (OSTI)

    Bruemmer, Stephen M.; Thomas, Larry E.; Vetrano, John S.; Simonen, Edward P.

    2003-10-31

    The research focuses on the high-resolution characterization of degradation microstructures and microchemistries in specimens tested under controlled conditions for the environment and for the material where in-service complexities can be minimized. Thermodynamic and kinetic modeling of crack-tip processes is employed to analyze corrosion-induced structures and gain insights into degradation mechanisms. Novel mechanistic ''fingerprinting'' of crack-tip structures is used to isolate causes of environmental cracking in tandem with quantitative measurements of crack growth. Sample preparation methods and advanced analytical techniques are used to characterize corrosion/oxidation reactions and crack-tip structures at near atomic dimensions in order to gain insight into fundamental environmental cracking mechanisms. Reactions at buried interfaces, not accessible by conventional approaches, are being systematically interrogated. Crack-growth experiments in high-temperature water environments are evaluating and isolating the effects of material condition (matrix strength, grain boundary composition and precipitation) on stress corrosion cracking (SCC). The fundamental understanding of crack advance mechanisms will establish the basis to design new corrosion-resistant alloys for current light-water reactors and advanced reactor systems.

  19. Multiple use of waste catalysts with and without regeneration for waste polymer cracking

    SciTech Connect (OSTI)

    Salmiaton, A.; Garforth, A.A.

    2011-06-15

    Waste plastics contain a substantial number of valuable chemicals. The wastes from post-consumer as well as from industrial production can be recycled to valuable chemical feedstock, which can be used in refineries and/or petrochemical industries. This chemical recycling process is an ideal approach in recycling the waste for a better environment. Polymer cracking using a laboratory fluidised bed reactor concentrated on the used highly contaminated catalyst, E-Cat 2. Even though E-Cat 2 had low activity due to fewer acid sites, the products yielded were similar with amorphous ASA and were far better than thermal cracking. The high levels of heavy metals, namely nickel and vanadium, deposited during their lifetime as an FCC catalyst, did not greatly affect on the catalyst activity. It was also shown that E-Cat 2 could be used with and without regeneration. Although there was more deactivation when there was no regeneration step, the yield of gases (C{sub 2}-C{sub 7}) remained fairly constant. For the first time, these results indicate that 'waste' FCC catalyst (E-Cat) is a good candidate for future feedstock recycling of polymer waste. The major benefits of using E-Cat are a low market price, the ability to tolerate reuse and regeneration capacity.

  20. Oxidation-resistant, solution-processed plasmonic Ni nanochain-SiO{sub x} (x?thermal absorbers

    SciTech Connect (OSTI)

    Yu, Xiaobai; Wang, Xiaoxin; Liu, Jifeng; Zhang, Qinglin; Li, Juchuan

    2014-08-21

    Metal oxidation at high temperatures has long been a challenge in cermet solar thermal absorbers, which impedes the development of atmospherically stable, high-temperature, high-performance concentrated solar power (CSP) systems. In this work, we demonstrate solution-processed Ni nanochain-SiO{sub x} (x?thermal absorbers that exhibit a strong anti-oxidation behavior up to 600?°C in air. The thermal stability is far superior to previously reported Ni nanoparticle-Al{sub 2}O{sub 3} selective solar thermal absorbers, which readily oxidize at 450?°C. The SiO{sub x} (x?processed by low-cost solution-chemical methods for future generations of CSP systems.

  1. Controlled etching of hexagonal ZnO architectures in an alcohol thermal process

    SciTech Connect (OSTI)

    Wu, Junshu [State Key Laboratory of Fine Chemicals, Department of Materials Science and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012 (China)] [State Key Laboratory of Fine Chemicals, Department of Materials Science and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012 (China); Xue, Dongfeng, E-mail: dfxue@chem.dlut.edu.cn [State Key Laboratory of Fine Chemicals, Department of Materials Science and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012 (China)] [State Key Laboratory of Fine Chemicals, Department of Materials Science and Chemical Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian 116012 (China)

    2010-03-15

    An alcohol thermal technique was applied to the controlled growth of hexagonal ZnO architectures via selective chemical etching. ZnO microdisks were produced first under mild alcohol thermal conditions in presence of formamide. Due to a higher surface energy/atomic density of Zn{sup 2+} {l_brace}0 0 0 1{r_brace} than that of the other faces, hexagonal ZnO microring was obtained by selectively etching positive polar surface of disk-like precursor with a high density of planar defects at the center. The selective etching of ZnO is related to its crystallographic characteristics of surface polarity and chemical activities, which opens a new opportunity for the shape-controlled synthesis of wurtzite-structured materials.

  2. Boundary integral formulation for interfacial cracks in thermodiffusive bimaterials

    E-Print Network [OSTI]

    L. Morini; A. Piccolroaz

    2015-04-29

    An original boundary integral formulation is proposed for the problem of a semi-infinite crack at the interface between two dissimilar elastic materials in the presence of heat flows and mass diffusion. Symmetric and skew-symmetric weight function matrices are used together with a generalized Betti's reciprocity theorem in order to derive a system of integral equations that relate the applied loading, the temperature and mass concentration fields, the heat and mass fluxes on the fracture surfaces and the resulting crack opening. The obtained integral identities can have many relevant applications, such as for the modelling of crack and damage processes at the interface between different components in electrochemical energy devices characterized by multi-layered structures (solid oxide fuel cells and lithium ions batteries).

  3. Rapid low-temperature processing of metal-oxide thin film transistors with combined far ultraviolet and thermal annealing

    SciTech Connect (OSTI)

    Leppäniemi, J. Ojanperä, K.; Kololuoma, T.; Huttunen, O.-H.; Majumdar, H.; Alastalo, A.; Dahl, J.; Tuominen, M.; Laukkanen, P.

    2014-09-15

    We propose a combined far ultraviolet (FUV) and thermal annealing method of metal-nitrate-based precursor solutions that allows efficient conversion of the precursor to metal-oxide semiconductor (indium zinc oxide, IZO, and indium oxide, In{sub 2}O{sub 3}) both at low-temperature and in short processing time. The combined annealing method enables a reduction of more than 100?°C in annealing temperature when compared to thermally annealed reference thin-film transistor (TFT) devices of similar performance. Amorphous IZO films annealed at 250?°C with FUV for 5?min yield enhancement-mode TFTs with saturation mobility of ?1?cm{sup 2}/(V·s). Amorphous In{sub 2}O{sub 3} films annealed for 15?min with FUV at temperatures of 180?°C and 200?°C yield TFTs with low-hysteresis and saturation mobility of 3.2?cm{sup 2}/(V·s) and 7.5?cm{sup 2}/(V·s), respectively. The precursor condensation process is clarified with x-ray photoelectron spectroscopy measurements. Introducing the FUV irradiation at 160?nm expedites the condensation process via in situ hydroxyl radical generation that results in the rapid formation of a continuous metal-oxygen-metal structure in the film. The results of this paper are relevant in order to upscale printed electronics fabrication to production-scale roll-to-roll environments.

  4. Cracking in liquid petroleum gas Horton spheres

    SciTech Connect (OSTI)

    Trivedi, D.K. Gupta, S.C.

    1997-07-01

    A gas processing plant on the western coast of India produces sweet gas after processing sour natural gas. Liquid petroleum gas (LPG) is recovered from the sweet gas. The LPG, containing a H{sub 2}S concentration of 10 ppm to 20 ppm, is stored in Horton spheres, each 17 m in diameter with a capacity of {minus}27 C to 55 C. Horton spheres for containing liquid petroleum gas (LPG) were fabricated on-site using prestressed plates of high-strength carbon steel (CS) SA 537 Class-1 with post-weld heat treatment. High-residual tensile stresses and hydrogen absorption from H{sub 2}S present in LPG could be the cause of cracking at weld and heat-affected zone interfaces at high hardness locations. Recommendations are given for inspection and use of lower-strength CS and improved welding procedures.

  5. Hydrocracking catalysts and processes

    SciTech Connect (OSTI)

    Dolbear, G.E. [G.E. Dolbear and Associates, Diamond Bar, CA (United States)

    1995-12-31

    Hydrocracking processes convert aromatic gas oils into high quality gasoline, diesel, and turbine stocks. They operate at high hydrogen pressures, typically greater than 1500 psig. Operating temperatures range from 600-700{degrees}F (315-382{degrees}C). Commercial catalysts vary in activity and selectivity, allowing process designers to emphasize middle distillates, naphtha, or both. Catalysts are quite stable in use, with two year unit run lengths typical. A pretreatment step to remove nitrogen compounds is usually part of the same process unit. These HDN units operate integrally with the hydrocracking. The hydrogenation reactions are strongly exothermic, while the cracking is roughly thermal neutral. This combination can lead to temperature runaways. To avoid this, cold hydrogen is injected at several points in hydrocracking reactors. The mechanics of mixing this hydrogen with the oil and redistributing the mixture over the catalyst bed are very important in controlling process operation and ensuring long catalyst life.

  6. Prediction of crack propagation paths in the unit cell of SOFC stacks

    SciTech Connect (OSTI)

    Joulaee, N.; Makradi, A.; Ahzi, Said; Khaleel, Mohammad A.; Koeppel, Brian J.

    2009-08-01

    Planar Solid Oxide Fuel Cells (SOFC) stacks are multi-material layered systems with different thermo-mechanical properties. Due to their severe thermal loading, these layers have to meet high demands to preserve their mechanical integrity without initiation and propagation of fracture. Here, we focus on a typical unit cell of the stack which consists of positive electrode-electrolyte-negative electrode (PEN). Based on the mechanical properties of each layer and their interfaces, an energy criterion as a function of crack length is used for the prediction of possible crack extensions in the PEN. This criterion is a pure local criterion, independent of applied loads and geometry of the specimen. An analysis of the competition between crack deflections in the interfaces and crack penetration in layers is presented.

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

    E-Print Network [OSTI]

    Morgan, Stephen Philip

    2011-01-01

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

  8. Turbulent thermalization process in heavy-ion collisions at ultrarelativistic energies

    E-Print Network [OSTI]

    J. Berges; K. Boguslavski; S. Schlichting; R. Venugopalan

    2014-03-02

    The non-equilibrium evolution of heavy-ion collisions is studied in the limit of weak coupling at very high energy employing lattice simulations of the classical Yang-Mills equations. Performing the largest classical-statistical simulations to date, we find that the dynamics of the longitudinally expanding plasma becomes independent of the details of the initial conditions. After a transient regime dominated by plasma instabilities and free streaming, the subsequent space-time evolution is governed by a nonthermal fixed point, where the system exhibits the self-similar dynamics characteristic of wave turbulence. This allows us to distinguish between different kinetic scenarios in the classical regime. Within the accuracy of our simulations, the scaling behavior found is consistent with the ``bottom-up" thermalization scenario.

  9. EFFECT OF ELECTROLYZER CONFIGURATION AND PERFORMANCE ON HYBRID SULFUR PROCESS NET THERMAL EFFICIENCY

    SciTech Connect (OSTI)

    Gorensek, M

    2007-03-16

    Hybrid Sulfur cycle is gaining popularity as a possible means for massive production of hydrogen from nuclear energy. Several different ways of carrying out the SO{sub 2}-depolarized electrolysis step are being pursued by a number of researchers. These alternatives are evaluated with complete flowsheet simulations and on a common design basis using Aspen Plus{trademark}. Sensitivity analyses are performed to assess the performance potential of each configuration, and the flowsheets are optimized for energy recovery. Net thermal efficiencies are calculated for the best set of operating conditions for each flowsheet and the results compared. This will help focus attention on the most promising electrolysis alternatives. The sensitivity analyses should also help identify those features that offer the greatest potential for improvement.

  10. The Chemistry of the Thermal DeNOx Process: A Review of the Technology's Possible Application to control of NOx from Diesel Engines

    SciTech Connect (OSTI)

    Lyon, Richard

    2001-08-05

    This paper presents a review of the Thermal DeNOx process with respect to its application to control of NOx emissions from diesel engines. The chemistry of the process is discussed first in empirical and then theoretical terms. Based on this discussion the possibilities of applying the process to controlling NOx emissions from diesel engines is considered. Two options are examined, modifying the requirements of the chemistry of the Thermal DeNOx process to suit the conditions provided by diesel engines and modifying the engines to provide the conditions required by the process chemistry. While the former examination did not reveal any promising opportunities, the latter did. Turbocharged diesel engine systems in which the turbocharger is a net producer of power seem capable of providing the conditions necessary for NOx reduction via the Thermal DeNOx reaction.

  11. Nanocrystallization of LiCoO2 Cathodes for Thin Film Batteries Utilizing Pulse Thermal Processing

    SciTech Connect (OSTI)

    2009-04-01

    This factsheet describes a study whose focus is on the nanocrystallization of the LiCoO2 cathode thin films on polyimide substrates and evaluate the microstructural evolution and resistance as a function of PTP processing conditions.

  12. Controlled Thermal-Mechanical Processing of Tubes and Pipes for Enhanced Manufacturing and Performance

    SciTech Connect (OSTI)

    Kolarik, Robert V.

    2005-11-11

    The Alloy Steel Business of The Timken Company won an award for the controlled thermo-mechanical processing (CTMP) project and assembled a strong international public/private partnership to execute the project. The premise of the CTMP work was to combine Timken's product understanding with its process expertise and knowledge of metallurgical and deformation fundamentals developed during the project to build a predictive process design capability. The CTMP effort succeeded in delivering a pc-based capability in the tube optimization model, with a virtual pilot plant (VPP) feature to represent the desired tube making process to predict the resultant microstructure tailored for the desired application. Additional tasks included a system for direct, online measurement of grain size and demonstration of application of CTMP via robotically enhanced manufacturing.

  13. High-temperature microfluidic systems for thermally-efficient fuel processing

    E-Print Network [OSTI]

    Arana, Leonel R

    2003-01-01

    Miniaturized fuel cell systems have the potential to outperform batteries in powering a variety of portable electronics. The key to this technology is the ability to efficiently process an easily-stored, energy-dense fuel. ...

  14. Iron-Based Amorphous Coatings Produced by HVOF Thermal Spray Processing-Coating Structure and Properties

    SciTech Connect (OSTI)

    Beardsley, M B

    2008-03-26

    The feasibility to coat large SNF/HLW containers with a structurally amorphous material (SAM) was demonstrated on sub-scale models fabricated from Type 316L stainless steel. The sub-scale model were coated with SAM 1651 material using kerosene high velocity oxygen fuel (HVOF) torch to thicknesses ranging from 1 mm to 2 mm. The process parameters such as standoff distance, oxygen flow, and kerosene flow, were optimized in order to improve the corrosion properties of the coatings. Testing in an electrochemical cell and long-term exposure to a salt spray environment were used to guide the selection of process parameters.

  15. The influence of cracks in rotating shafts

    E-Print Network [OSTI]

    Sinou, Jean-Jacques

    2008-01-01

    In this paper, the influence of transverse cracks in a rotating shaft is analysed. The paper addresses the two distinct issues of the changes in modal properties and the influence of crack breathing on dynamic response during operation. Moreover, the evolution of the orbit of a cracked rotor near half of the first resonance frequency is investigated. The results provide a possible basis for an on-line monitoring system. In order to conduct this study, the dynamic response of a rotor with a breathing crack is evaluated by using the alternate frequency/time domain approach. It is shown that this method evaluates the nonlinear behaviour of the rotor system rapidly and efficiently by modelling the breathing crack with a truncated Fourier series. The dynamic response obtained by applying this method is compared with that evaluated through numerical integration. The resulting orbit during transient operation is presented and some distinguishing features of a cracked rotor are examined.

  16. The influence of cracks in rotating shafts

    E-Print Network [OSTI]

    Jean-Jacques Sinou; A. W. Lees

    2008-01-19

    In this paper, the influence of transverse cracks in a rotating shaft is analysed. The paper addresses the two distinct issues of the changes in modal properties and the influence of crack breathing on dynamic response during operation. Moreover, the evolution of the orbit of a cracked rotor near half of the first resonance frequency is investigated. The results provide a possible basis for an on-line monitoring system. In order to conduct this study, the dynamic response of a rotor with a breathing crack is evaluated by using the alternate frequency/time domain approach. It is shown that this method evaluates the nonlinear behaviour of the rotor system rapidly and efficiently by modelling the breathing crack with a truncated Fourier series. The dynamic response obtained by applying this method is compared with that evaluated through numerical integration. The resulting orbit during transient operation is presented and some distinguishing features of a cracked rotor are examined.

  17. A fast hybrid start-up process for thermally self-sustained catalytic n-butane reforming in micro-SOFC power plants

    E-Print Network [OSTI]

    Daraio, Chiara

    A fast hybrid start-up process for thermally self-sustained catalytic n-butane reforming in micro at the investigation and optimization of a hybrid start-up process for a self-sustained reactor for n-butane to syngas

  18. Materials Science and Engineering A 404 (2005) 2632 Numerical simulations of crack formation from pegs in

    E-Print Network [OSTI]

    Fleck, Norman A.

    2005-01-01

    in gas turbines for propulsion and power generation [1­4]. The systems are susceptible to performanceMaterials Science and Engineering A 404 (2005) 26­32 Numerical simulations of crack formation from pegs in thermal barrier systems with NiCoCrAlY bond coats H.X. Zhua, N.A. Flecka,, A.C.F. Cocksb, A

  19. Characterization of geothermal reservoir crack patterns using...

    Open Energy Info (EERE)

    with form History Characterization of geothermal reservoir crack patterns using shear-wave splitting Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal...

  20. Study of the effect of plasma-striking atmosphere on Fe-oxidation in thermal dc arc-plasma processing

    SciTech Connect (OSTI)

    Banerjee, I.; Khollam, Y. B.; Mahapatra, S. K.; Das, A. K.; Bhoraskar, S. V.

    2010-11-15

    The effect of plasma-striking atmosphere: air and air+Ar-gas on the crystallization of Fe-oxide phases was studied using dc thermal arc-plasma processing route. The powders were characterized by x-ray diffraction, vibrating sample magnetometry, transmission electron microscopy, and Moessbauer spectroscopy techniques. At room temperature and O{sub 2} rich atmosphere, arc-evaporated Fe{sup 2+} ions oxidize into either {gamma}-Fe{sub 2}O{sub 3} or Fe{sub 3}O{sub 4} depending upon the combining ratio of Fe with molecular O{sub 2}. Fe/O ratio could be adjusted using proper flow rate of Ar gas to crystallize the pure {gamma}-Fe{sub 2}O{sub 3}.

  1. Oxidation resistant high temperature thermal cycling resistant coatings on silicon-based substrates and process for the production thereof

    DOE Patents [OSTI]

    Sarin, V.K.

    1990-08-21

    An oxidation resistant, high temperature thermal cycling resistant coated ceramic article for ceramic heat engine applications is disclosed. The substrate is a silicon-based material, i.e. a silicon nitride- or silicon carbide-based monolithic or composite material. The coating is a graded coating of at least two layers: an intermediate AlN or Al[sub x]N[sub y]O[sub z] layer and an aluminum oxide or zirconium oxide outer layer. The composition of the coating changes gradually from that of the substrate to that of the AlN or Al[sub x]N[sub y]O[sub z] layer and further to the composition of the aluminum oxide or zirconium oxide outer layer. Other layers may be deposited over the aluminum oxide layer. A CVD process for depositing the graded coating on the substrate is also disclosed.

  2. Oxidation resistant high temperature thermal cycling resistant coatings on silicon-based substrates and process for the production thereof

    DOE Patents [OSTI]

    Sarin, Vinod K. (Lexington, MA)

    1990-01-01

    An oxidation resistant, high temperature thermal cycling resistant coated ceramic article for ceramic heat engine applications. The substrate is a silicon-based material, i.e. a silicon nitride- or silicon carbide-based monolithic or composite material. The coating is a graded coating of at least two layers: an intermediate AlN or Al.sub.x N.sub.y O.sub.z layer and an aluminum oxide or zirconium oxide outer layer. The composition of the coating changes gradually from that of the substrate to that of the AlN or Al.sub.x N.sub.y O.sub.z layer and further to the composition of the aluminum oxide or zirconium oxide outer layer. Other layers may be deposited over the aluminum oxide layer. A CVD process for depositing the graded coating on the substrate is also disclosed.

  3. Supporting technology for enhanced oil recovery: Sixth amendment and extension to Annex IV enhanced oil recovery thermal processes

    SciTech Connect (OSTI)

    Reid, T.B. (USDOE Bartlesville Project Office, OK (United States)); Rivas, O. (INTEVEP, Filial de Petroleos de Venezuela, SA, Caracas (Venezuela))

    1991-10-01

    This report contains the results of efforts under the six tasks of the Sixth Amendment and Extension of Annex 4, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Agreement. The report is presented in sections (for each of the 6 tasks) and each section contains one or more reports prepared by various individuals or groups describing the results of efforts under each of the tasks. A statement of each task, taken from the agreement, is presented on the first page of each section. The tasks are numbered 44 through 49. Tasks are: DOE-SUPRI-laboratory research on steam foam, CAT-SCAN, and in-situ combustion; INTEVEP-laboratory research and field projects on steam foam; DOE-NIPER-laboratory research and field projects light oil steam flooding; INTEVEP-laboratory research and field studies on wellbore heat losses; DOE-LLNL-laboratory research and field projects on electromagnetic induction tomography; INTEVEP-laoboratory research on mechanistic studies.

  4. Crack stability analysis of low alloy steel primary coolant pipe

    SciTech Connect (OSTI)

    Tanaka, T.; Kameyama, M. [Kansai Electric Power Company, Osaka (Japan); Urabe, Y. [Mitsubishi Heavy Industries, Ltd., Takasago (Japan)] [and others

    1997-04-01

    At present, cast duplex stainless steel has been used for the primary coolant piping of PWRs in Japan and joints of dissimilar material have been applied for welding to reactor vessels and steam generators. For the primary coolant piping of the next APWR plants, application of low alloy steel that results in designing main loops with the same material is being studied. It means that there is no need to weld low alloy steel with stainless steel and that makes it possible to reduce the welding length. Attenuation of Ultra Sonic Wave Intensity is lower for low alloy steel than for stainless steel and they have advantageous inspection characteristics. In addition to that, the thermal expansion rate is smaller for low alloy steel than for stainless steel. In consideration of the above features of low alloy steel, the overall reliability of primary coolant piping is expected to be improved. Therefore, for the evaluation of crack stability of low alloy steel piping to be applied for primary loops, elastic-plastic future mechanics analysis was performed by means of a three-dimensioned FEM. The evaluation results for the low alloy steel pipings show that cracks will not grow into unstable fractures under maximum design load conditions, even when such a circumferential crack is assumed to be 6 times the size of the wall thickness.

  5. Thermal barrier coating resistant to sintering

    DOE Patents [OSTI]

    Subramanian, Ramesh; Seth, Brig B.

    2005-08-23

    A device (10) is made, having a ceramic thermal barrier coating layer (16) characterized by a microstructure having gaps (18) with a sintering inhibiting material (22) disposed on the columns (20) within the gaps (18). The sintering resistant material (22) is stable over the range of operating temperatures of the device (10), is not soluble with the underlying ceramic layer (16) and is applied by a process that is not an electron beam physical vapor deposition process. The sintering inhibiting material (22) has a morphology adapted to improve the functionality of the sintering inhibiting material (22), characterized as continuous, nodule, rivulet, grain, crack, flake and combinations thereof and being disposed within at least some of the vertical and horizontal gaps.

  6. On Macroscopic and MicroscopicAnalyses for Crack Initiationand Crack Growth Toughness in DuctileAlloys

    E-Print Network [OSTI]

    Ritchie, Robert

    On Macroscopic and MicroscopicAnalyses for Crack Initiationand Crack Growth Toughness in Ductile microvoid coalescence, expressions are shown for the fracture toughness of materials in terms and the nondimensionalized crack initiation fracture toughness Ji~ is described and shown to yield a good fit to experimental

  7. Thermal Energy Storage/Heat Recovery and Energy Conservation in Food Processing 

    E-Print Network [OSTI]

    Combes, R. S.; Boykin, W. B.

    1980-01-01

    this hot water to the plant drain, a heat A project conducted by the Georgia Tech exchanger was installed at the Gold Kist plant to Engineering Experiment Station to demonstrate preheat scald tank makeup water by screening, col waste heat recovery... in the Gold Kist, Inc. poultry lecting and pumping the overflow from the scald tank processing plant located in Ellijay, Georgia will through the heat exchanger counterflow to the incom 436 ESL-IE-80-04-83 Proceedings from the Second Industrial Energy...

  8. Crack Propagation Fracture Toughness of Several Wood Species Elijah Wilson, Meisam Shir Mohammadi, and John A. Nairn

    E-Print Network [OSTI]

    Nairn, John A.

    1 Crack Propagation Fracture Toughness of Several Wood Species Elijah Wilson, Meisam Shir Mohammadi In materials with process zones, such as fiber bridging zones in wood, it is crucial to characterize fracture toughness as a function of crack growth, known as the material's R curve. Here, a new fracture testing

  9. Method for making dense crack free thin films

    DOE Patents [OSTI]

    Jacobson, Craig P. (Lafayette, CA); Visco, Steven J. (Berkeley, CA); De Jonghe, Lutgard C. (Lafayette, CA)

    2007-01-16

    The process described herein provides a simple and cost effective method for making crack free, high density thin ceramic film. The steps involve depositing a layer of a ceramic material on a porous or dense substrate. The deposited layer is compacted and then the resultant laminate is sintered to achieve a higher density than would have been possible without the pre-firing compaction step.

  10. New insight into $nd\\rightarrow$ $^3H?$ process at thermal energy with pionless effective field theory

    E-Print Network [OSTI]

    M. Moeini Arani; H. Nematollahi; N. Mahboubi; S. Bayegan

    2014-06-25

    We take a new look at the neutron radiative capture by a deuteron at thermal energy with the pionless effective field theory (EFT($\\pi\\!\\!\\!/$)) approach. We present in detail the calculation of $nd\\rightarrow$ $^3H\\gamma$ amplitudes for incoming doublet and quartet channels leading to the formation of a triton fully in the projection method based on the cluster-configuration space approach. In the present work, we consider all possible one-body and two-body photon interaction diagrams. In fact, additional diagrams that make significant changes in the results of the calculation of the total cross section in the $nd\\rightarrow$ $^3H\\gamma$ process are included in this study. The properly normalized triton wave function is calculated and taken into consideration. We compare the cross section of the dominant magnetic M1-transition of $nd\\rightarrow$ $^3H\\gamma$ up to next-to-next-to-leading order $\\textrm{N}^2\\textrm{LO}$ with the results of the previous model-dependent theoretical calculations and experimental data. The more acceptable results for cross section $\\sigma^{(2)}_{tot}=0.297\\;(\\textrm{LO})+0.124\\;(\\textrm{NLO})+0.048\\;(\\textrm{N}^2\\textrm{LO})=[0.469\\pm0.033]\\:\\textrm{mb}$ show order by order convergence and cutoff independence. No three-body currents are needed to renormalize observables up to $\\textrm{N}^2\\textrm{LO}$ in this process.

  11. Constraint effects observed in crack initiation stretch

    SciTech Connect (OSTI)

    Lambert, D.M.; Ernst, H.A.

    1995-12-31

    The current paper characterizes constraint in fracture: J-modified resistance (Jr) curves were developed for two tough structural materials, 6061-T651 (aluminum) and IN718-STA1 (nickel-base superalloy). A wide variety of configurations was tested to consider load configurations from bending to tension including three specimen types (compact tension, center-crack tension, and single-edge notched tension), and a range of ligament lengths and thicknesses, as well as side-grooved and smooth-sided ligaments. The Jr curves exhibited an inflection point after some crack extension, and the data were excluded beyond the inflection. Qualified Jr curves for the two materials showed similar behavior, but R-curves were identical for equal ligament length-to-thickness ratio (RL), for the aluminum alloy, with increasing slope for increasing RL, while for the nickel, the resistance curves aligned for equal ligament thickness, B, and the slope increased for decreasing B. Displacements at the original crack tip (CToD) were recorded throughout the test for several specimens. CToD-versus-crack extension curves were developed, and data were excluded beyond the inflection point (as with the Jr curves). The data collapsed into two distinct curves, thought to represent the surface, plane stress effect and the central, plane strain effect. This was observed for both materials. A technique called profiling is presented for the aluminum alloy only, where the crack face displacements are recorded at the final point of the test as a function of the position throughout the crack cavity, along with an effort to extract the observations in a usable form. Displacements were consistent throughout the cross-section at and behind the original crack tip. In the region where the crack grew, this displacement was developed by a combination of stretch and crack growth. The stretch required to initiate crack extension was a function of the depth beneath the surface into the cross-section.

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

    SciTech Connect (OSTI)

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

    2014-01-09

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

  13. Prediction of thermal crack spacing D.H. Timm a

    E-Print Network [OSTI]

    Guzina, Bojan

    of Civil Engineering, University of Minnesota, 500 Pillsbury Dr. S.E., Minneapolis, MN 55455, USA Received cooling event in the winter of 1996 when the surface pavement temperature dropped below )30 °C

  14. A review of carbide fuel corrosion for nuclear thermal propulsion applications

    SciTech Connect (OSTI)

    Pelaccio, D.G.; El-Genk, M.S. [Univ. of New Mexico, Albuquerque, NM (United States). Inst. for Space Nuclear Power Studies; Butt, D.P. [Los Alamos National Lab., NM (United States)

    1993-12-01

    At the operation conditions of interest in nuclear thermal propulsion reactors, carbide materials have been known to exhibit a number of life limiting phenomena. These include the formation of liquid, loss by vaporization, creep and corresponding gas flow restrictions, and local corrosion and fuel structure degradation due to excessive mechanical and/or thermal loading. In addition, the radiation environment in the reactor core can produce a substantial change in its local physical properties, which can produce high thermal stresses and corresponding stress fractures (cracking). Time-temperature history and cyclic operation of the nuclear reactor can also accelerate some of these processes. The University of New Mexico`s Institute for Space Nuclear Power Studies, under NASA sponsorship has recently initiated a study to model the complicated hydrogen corrosion process. In support of this effort, an extensive review of the open literature was performed, and a technical expert workshop was conducted. This paper summarizes the results of this review.

  15. Amorphous oxide semiconductors are promising new materials for various optoelectronic applications. In this study, improved electrical and optical properties upon thermal and microwave processing of

    E-Print Network [OSTI]

    Amorphous oxide semiconductors are promising new materials for various optoelectronic applications. In this study, improved electrical and optical properties upon thermal and microwave processing of mixed-oxide semiconductors are reported. First, arsenic-doped silicon was used as a model system to understand susceptor

  16. 12.11.2014bo Akademi Univ -Thermal and Flow Engineering Piispankatu 8, 20500 Turku 1/32 4. Refrigeration process comparison;

    E-Print Network [OSTI]

    Zevenhoven, Ron

    12.11.2014Ĺbo Akademi Univ - Thermal and Flow Engineering Piispankatu 8, 20500 Turku 1/32 4 Engineering Laboratory / Värme- och strömningsteknik tel. 3223 ; ron.zevenhoven@abo.fi Kylteknik ("KYL and Flow Engineering Piispankatu 8, 20500 Turku 2/32 4.1 Refrigeration process comparison #12;12.11.2014Ĺbo

  17. Modeling Thermal-Hydrologic Processes for a Heated Fractured Rock System: Impact of a Capillary-Pressure Maximum

    E-Print Network [OSTI]

    Sun, Y.; Buscheck, T. A.; Lee, K. H.; Hao, Y.; James, S. C.

    2010-01-01

    drift-scale thermal test at Yucca Mountain, Nevada. Lawrencemechanical analyses of the Yucca Mountain Drift Scale Test–emplacement tunnels at Yucca Mountain, Nevada. J. Contam.

  18. A study of the mechanism of laser welding defects in low thermal expansion superalloy GH909

    SciTech Connect (OSTI)

    Yan, Fei; Wang, Chunming, E-mail: yanxiangfei225@163.com; Wang, Yajun; Hu, Xiyuan; Wang, Tianjiao; Li, Jianmin; Li, Guozhu

    2013-04-15

    In this paper, we describe experimental laser welding of low-thermal-expansion superalloy GH909. The main welding defects of GH909 by laser in the weld are liquation cracks and porosities, including hydrogen and carbon monoxide porosity. The forming mechanism of laser welding defects was investigated. This investigation was conducted using an optical microscope, scanning electron microscope, energy diffraction spectrum, X-ray diffractometer and other methodologies. The results demonstrated that porosities appearing in the central weld were related to incomplete removal of oxide film on the surface of the welding samples. The porosities produced by these bubbles were formed as a result of residual hydrogen or oxygenium in the weld. These elements failed to escape from the weld since laser welding has both a rapid welding speed and cooling rate. The emerging crack in the heat affected zone is a liquation crack and extends along the grain boundary as a result of composition segregation. Laves–Ni{sub 2}Ti phase with low melting point is a harmful phase, and the stress causes grain boundaries to liquefy, migrate and even crack. Removing the oxides on the surface of the samples before welding and carefully controlling technological parameters can reduce welding defects and improve formation of the GH909 alloy weld. - Highlights: ? It is a new process for the forming of GH909 alloy via laser welding. ? The forming mechanism of laser welding defects in GH909 has been studied. ? It may be a means to improve the efficiency of aircraft engine production.

  19. Venezuela-MEM/USA-DOE Fossil Energy Report IV-11: Supporting technology for enhanced oil recovery - EOR thermal processes

    SciTech Connect (OSTI)

    Venezuela

    2000-04-06

    This report contains the results of efforts under the six tasks of the Tenth Amendment anti Extension of Annex IV, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Energy Agreement. This report is presented in sections (for each of the six Tasks) and each section contains one or more reports that were prepared to describe the results of the effort under each of the Tasks. A statement of each Task, taken from the Agreement Between Project Managers, is presented on the first page of each section. The Tasks are numbered 68 through 73. The first through tenth report on research performed under Annex IV Venezuela MEM/USA-DOE Fossil Energy Report Number IV-1, IV-2, IV-3, IV-4, IV-5, IV-6, IV-7, IV-8, IV-9, IV-10 contain the results of the first 67 Tasks. These reports are dated April 1983, August 1984, March 1986, July 1987, November 1988, December 1989, October 1991, February 1993, March 1995, and December 1997, respectively.

  20. Oxidation Behavior of In-Flight Molten Aluminum Droplets in the Twin-Wire Electric Arc Thermal Spray Process

    SciTech Connect (OSTI)

    Donna Post Guillen; Brian G. Williams

    2005-05-01

    This paper examines the in-flight oxidation of molten aluminum sprayed in air using the twin-wire electric arc (TWEA) thermal spray process. The oxidation reaction of aluminum in air is highly exothermic and is represented by a heat generation term in the energy balance. Aerodynamic shear at the droplet surface enhances the amount of in-flight oxidation by: (1) promoting entrainment and mixing of the surface oxides within the droplet, and (2) causing a continuous heat generation effect that increases droplet temperature over that of a droplet without internal circulation. This continual source of heat input keeps the droplets in a liquid state during flight. A linear rate law based on the Mott-Cabrera theory was used to estimate the growth of the surface oxide layer formed during droplet flight. The calculated oxide volume fraction of an average droplet at impact agrees well with the experimentally determined oxide content for a typical TWEA-sprayed aluminum coating, which ranges from 3.3 to 12.7%. An explanation is provided for the elevated, nearly constant surface temperature (~ 2000 oC) of the droplets during flight to the substrate and shows that the majority of oxide content in the coating is produced during flight, rather than after deposition.

  1. Vortex flow in the technology of radiation wave cracking (RWC)

    E-Print Network [OSTI]

    L. A. Tsoy; V. N. Kolushov; A. G. Komarov; A. N. Tsoy

    2012-09-16

    This article examines the theory of vortex flows in relation to the processes occurring in the radiation-wave cracking of crude oil, when the crude oil is sprayed into the gas stream in the form of a mist and then is fed into the reactor, where it is treated by the accelerated electrons and the UHF radiation. The output of this process are the products with the specified parameters (high-octane petroleum products). This process operates at the ambient pressure and temperature, which makes the process safer for industrial purposes. Besides the process itself, the authors described the equipment used in this process, as well as the parameters of the optimal process.

  2. Cracked-fuel mechanics. [PWR; BWR

    SciTech Connect (OSTI)

    Williford, R.E.; Lanning, D.D.

    1982-01-01

    This paper presents a modelling concept and a set of measurable parameters that have been shown to improve the prediction of the mechanical behavior of cracked fuel/cladding systems without added computational expense. The transition from classical annular gap/cylindrical pellet models to modified bulk properties and further to local behavior for cracked fuel systems is discussed. The results of laboratory experiments to verify these modelling parameters are shown. Data are also presented from laboratory experiments on unirradiated and irradiated rods which show that fuel rod mechanical response depends on fuel fragment size. The impact of these data on cracked fuel behavior and failure modelling is also discussed.

  3. Fatigue Enhancement of Undersized, Drilled Crack-Stop Holes

    E-Print Network [OSTI]

    Crain, Joshua Sakumura

    2010-04-20

    A common technique used to prevent the propagation of cracks in bridge girders is drilling crack-stop holes at the crack tips. By doing so, stress concentrations at the tip of the cracks are reduced and fatigue life of the ...

  4. Effect of Desiccation Cracks on Earth Embankments 

    E-Print Network [OSTI]

    Khandelwal, Siddharth

    2012-07-11

    Levees are earth structures used for flood protection. Due to their easy availability and low permeability, clays are the most common material used for the construction of levees. Clays are susceptible to desiccation cracks ...

  5. Prediction of early-age cracking of UHPC materials and structures : a thremo-chemo-mechanics approach

    E-Print Network [OSTI]

    Shim, JongMin, 1975-

    2005-01-01

    Ultra-High Performance Concrete [UHPC] has remarkable performance in mechanical properties, ductility, economical benefit, etc., but early-age cracking of UHPC can become an issue during the manufacturing process due to ...

  6. An investigation of penetrant techniques for detection of machining-induced surface-breaking cracks on monolithic ceramics

    SciTech Connect (OSTI)

    Forster, G.A.; Ellingson, W.A.

    1996-02-01

    The purpose of this effort was to evaluate penetrant methods for their ability to detect surface-breaking cracks in monolithic ceramic materials with an emphasis on detection of cracks generated by machining. There are two basic penetrant types, visible and fluorescent. The visible penetrant method is usually augmented by powder developers and cracks detected can be seen in visible light. Cracks detected by fluorescent penetrant are visible only under ultraviolet light used with or without a developer. The developer is basically a powder that wicks up penetrant from a crack to make it more observable. Although fluorescent penetrants were recommended in the literature survey conducted early in this effort, visible penetrants and two non-standard techniques, a capillary gaseous diffusion method under development at the institute of Chemical Physics in Moscow, and the {open_quotes}statiflux{close_quotes} method which involves use of electrically charged particles, were also investigated. SiAlON ring specimens (1 in. diameter, 3/4 in. wide) which had been subjected to different thermal-shock cycles were used for these tests. The capillary gaseous diffusion method is based on ammonia; the detector is a specially impregnated paper much like litmus paper. As expected, visible dye penetrants offered no detection sensitivity for tight, surface-breaking cracks in ceramics. Although the non-standard statiflux method showed promise on high-crack-density specimens, it was ineffective on limited-crack-density specimens. The fluorescent penetrant method was superior for surface-breaking crack detection, but successful application of this procedure depends greatly on the skill of the user. Two presently available high-sensitivity fluorescent penetrants were then evaluated for detection of microcracks on Si{sub 3}N{sub 4} and SiC from different suppliers. Although 50X optical magnification may be sufficient for many applications, 200X magnification provides excellent delectability.

  7. Tests and analyses for fully plastic fracture mechanics of plane strain mode I crack growth

    SciTech Connect (OSTI)

    McClintock, F.A.; Parks, D.M.; Kim, Y.J.

    1995-12-31

    Under monotonic loading, structures should ideally be ductile enough to provide continued resistance during crack growth. For fully plastic crack growth in low strength alloys, existing asymptotic solutions for elastic-plastic growing cracks are not applicable because they reach the fracture strain only in regions small compared to the inhomogeneities of the actual fracture process. For the limiting case of non-hardening fully-plastic plane strain crack growth, in a number of geometries and loadings the near-tip fields are characterized in terms of three parameters: an effective angle 2{theta}{sub s} between a pair of slip planes, and the normal stress {sigma}{sub s} and the increment of displacement {delta}u{sub s} across the planes. This three-parameter characterization is in contrast to the one- or two-parameter (K or J and T or Q) characterization in linear or non-linear elastic fracture mechanics. These {theta}{sub s}, {sigma}{sub s}, and {delta}u{sub s} parameters are found form the far-field geometries and loadings through slip line fields or least upper bound analyses based on circular arcs. The resulting crack growth, in terms of the crack tip opening angle (CTOA), is a function of {theta}{sub s}, {sigma}{sub s}, and the material. The geometry of the crack growing between two moving slip planes emanating from its tip reduces this function to the critical fracture shear strain left behind the slip planes, {gamma}f, as a function of {sigma}{sub s}. {gamma}f({sigma}{sub s}) is found theoretically from a hole initiation and growth model. It is also found from preliminary fully plastic crack growth experiments on unequally grooved specimens with fixed-grip extension or 4-point bending of a 1018 CF steel.

  8. Analysis of the tube-sheet cracking in slurry oil steam , L.J. Qiao a,

    E-Print Network [OSTI]

    Volinsky, Alex A.

    , People's Republic of China b Jinzhou Petrochemical Corporation, China National Petroleum Corporation the tubes and the tube sheets, shown in Fig. 2. During the heat exchange process, the temperature analysis performed to simulate the hydraulic expansion process showed that this kind of cracking

  9. Preparation of silica aerogels with improved mechanical properties and extremely low thermal conductivities through modified sol-gel process

    E-Print Network [OSTI]

    Zuo, Yanjia

    2010-01-01

    Reported silica aerogels have a thermal conductivity as low as 15 mW/mK. The fragility of silica aerogels, however, makes them impractical for structural applications. The purpose of the study is to improve the ductility ...

  10. Development of Spatio-Temporal Wavelet Post Processing Techniques for Application to Thermal Hydraulic Experiments and Numerical Simulations 

    E-Print Network [OSTI]

    Salpeter, Nathaniel

    2012-07-16

    This work focuses on both high fidelity experimental and numerical thermal hydraulic studies and advanced frequency decomposition methods. The major contribution of this work is a proposed method for spatio-temporal decomposition of frequencies...

  11. Inuence of foreign-object damage on crack initiation and early crack growth during high-cycle fatigue of Ti6Al4V

    E-Print Network [OSTI]

    Ritchie, Robert

    ; Ti±6Al±4V 1. Introduction The high-cycle fatigue (HCF) of aircraft gas-turbine engine components has-cycle fatigue of Ti±6Al±4V J.O. Peters, R.O. Ritchie * Department of Materials Science and Mineral Engineering of small surface fatigue cracks in a Ti±6Al±4V alloy, processed for typical turbine blade applications

  12. Contstraint effects of shallow cracks in structures containing fillet weld toe cracks 

    E-Print Network [OSTI]

    Neligon, Melinda T

    1995-01-01

    for structures containing a/W--O.l and a/W--O.5 fillet weld toe cracks. The Anderson-Dodds scaling model is applied to quantify the effects of finite size on J contour integral values for structures containing a/W=O.l and a/W=0.5 fillet weld toe cracks loaded...

  13. Characterization of cracking restraint at sawcut joints using the German Cracking Frame 

    E-Print Network [OSTI]

    Vepakomma, Shilpa

    2002-01-01

    shrinkage and creep. Early age creep and shrinkage also appear to be key factors of stress and cracking. Experiments were run to provide insight on the effect of shrinkage and creep on crack developments. The results were useful in evaluating the behavior...

  14. Discontinuous surface cracks during stress corrosion cracking of stainless steel single crystal

    E-Print Network [OSTI]

    Volinsky, Alex A.

    becomes equal to the fracture toughness, KIC, the crack will open and prop- agate. Stroh showed a crack [18]. Therefore, the fracture of most FCC metals is ductile. The chemical environment changes KIC and Protection Center, Key Laboratory for Environmental Fracture (MOE), University of Science and Technology

  15. MATERIAL POINT METHOD CALCULATIONS WITH EXPLICIT CRACKS, FRACTURE PARAMETERS, AND CRACK

    E-Print Network [OSTI]

    Nairn, John A.

    MATERIAL POINT METHOD CALCULATIONS WITH EXPLICIT CRACKS, FRACTURE PARAMETERS, AND CRACK PROPAGATION." This new method has several advantages for numerical work on fracture. Compared to finite element analysis works well for calculating key fracture parameters such as J integral, stress intensity factors

  16. TRANSPORT THROUGH CRACKED CONCRETE: LITERATURE REVIEW

    SciTech Connect (OSTI)

    Langton, C.

    2012-05-11

    Concrete containment structures and cement-based fills and waste forms are used at the Savannah River Site to enhance the performance of shallow land disposal systems designed for containment of low-level radioactive waste. Understanding and measuring transport through cracked concrete is important for describing the initial condition of radioactive waste containment structures at the Savannah River Site (SRS) and for predicting performance of these structures over time. This report transmits the results of a literature review on transport through cracked concrete which was performed by Professor Jason Weiss, Purdue University per SRR0000678 (RFP-RQ00001029-WY). This review complements the NRC-sponsored literature review and assessment of factors relevant to performance of grouted systems for radioactive waste disposal. This review was performed by The Center for Nuclear Waste Regulatory Analyses, San Antonio, TX, and The University of Aberdeen, Aberdeen Scotland and was focused on tank closure. The objective of the literature review on transport through cracked concrete was to identify information in the open literature which can be applied to SRS transport models for cementitious containment structures, fills, and waste forms. In addition, the literature review was intended to: (1) Provide a framework for describing and classifying cracks in containment structures and cementitious materials used in radioactive waste disposal, (2) Document the state of knowledge and research related to transport through cracks in concrete for various exposure conditions, (3) Provide information or methodology for answering several specific questions related to cracking and transport in concrete, and (4) Provide information that can be used to design experiments on transport through cracked samples and actual structures.

  17. Biomaterials 28 (2007) 49014911 Stresscorrosion crack growth of SiNaKMgCaPO bioactive

    E-Print Network [OSTI]

    Ritchie, Robert

    2007-01-01

    Biomaterials 28 (2007) 4901­4911 Stress­corrosion crack growth of Si­Na­K­Mg­Ca­P­O bioactive the thermal expansion (in the range of 8.8­15.1 Â 10Ŕ6 1CŔ1 ) [19] ARTICLE IN PRESS www.elsevier.com/locate/biomaterials 0142-9612/$ - see front matter r 2007 Elsevier Ltd. All rights reserved. doi:10.1016/j.biomaterials

  18. Crack-arrest behavior in SEN wide plates of low-upper-shelf base metal tested under nonisothermal conditions: WP-2 series

    SciTech Connect (OSTI)

    Naus, D.J.; Keeney-Walker, J.; Bass, B.R.; Robinson, G.C. Jr.; Iskander, S.K.; Alexander, D.J. [Oak Ridge National Lab., TN (United States); Fields, R.J.; deWit, R.; Low, S.R. [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Schwartz, C.W. [Maryland Univ., College Park, MD (United States). Dept. of Mechanical Engineering; Johansson, I.B. [Royal Inst. of Tech., Stockholm (Sweden)

    1990-08-01

    The Heavy-Section Steel Technology (HSST) Program at the Oak Ridge National Laboratory under the sponsorship of the Nuclear Regulatory Commission is conducting analytical and experimental studies aimed at understanding the circumstances that would initiate the growth of an existing crack in a reactor pressure vessel (RPV) and the conditions leading to arrest of a propagating crack. Objectives of these studies are to determine (1) if the material will exhibit crack-arrest behavior when the driving force on a crack exceeds the ASME limit, (2) the relationship between K{sub Ia} and temperature, and (3) the interaction of fracture modes (arrest, stable crack growth, unstable crack growth, and tensile instability) when arrest occurs at high temperatures. In meeting these objectives, crack-arrest data are being developed over an expanded temperature range through tests involving large thermally shocked cylinders, pressurized thermally shocked vessels, and wide-plate specimens. The wide-plate specimens provide the opportunity for a significant number of data points to be obtained at relatively affordable costs. These tests are designed to provide fracture-toughness measurements approaching or above the onset of the Charpy upper-shelf regime in a rising toughness region and with an increasing driving force. This document discusses test methodology and results. 23 refs., 92 figs., 25 tabs.

  19. Recommendations for the shallow-crack fracture toughness testing task within the HSST (Heavy-Section Steel Technology) Program

    SciTech Connect (OSTI)

    Theiss, T.J. (Oak Ridge National Lab., TN (USA))

    1990-09-01

    Recommendations for Heavy-Section Steel Technology Program's investigation into the influence of crack depth on the fracture toughness of a steel prototypic of those in a reactor pressure vessel are included in this report. The motivation for this investigation lies in the fact that probabilistic fracture mechanics evaluations show that shallow flaws play a dominant role in the likelihood of vessel failure, and shallow-flaw specimens have exhibited an elevated toughness compared with conventional deep-notch fracture toughness specimens. Accordingly, the actual margin of safety of vessels may be greater than that predicted using existing deep-notch fracture-toughness results. The primary goal of the shallow-crack project is to investigate the influence of crack depth on fracture toughness under conditions prototypic of a reactor vessel. A limited data base of fracture toughness values will be assembled using a beam specimen of prototypic reactor vessel material and with a depth of 100 mm (4 in.). This will permit comparison of fracture-toughness data from deep-cracked and shallow-crack specimens, and this will be done for several test temperatures. Fracture-toughness data will be expressed in terms of the stress-intensity factor and crack-tip-opening displacement. Results of this investigation are expected to improve the understanding of shallow-flaw behavior in pressure vessels, thereby providing more realistic information for application to the pressurized-thermal shock issues. 33 refs., 17 figs.

  20. Crack detection using resonant ultrasound spectroscopy

    DOE Patents [OSTI]

    Migliori, Albert (Santa Fe, NM); Bell, Thomas M. (Santa Fe, NM); Rhodes, George W. (Albuquerque, NM)

    1994-01-01

    Method and apparatus are provided for detecting crack-like flaws in components. A plurality of exciting frequencies are generated and applied to a component in a dry condition to obtain a first ultrasonic spectrum of the component. The component is then wet with a selected liquid to penetrate any crack-like flaws in the component. The plurality of exciting frequencies are again applied to the component and a second ultrasonic spectrum of the component is obtained. The wet and dry ultrasonic spectra are then analyzed to determine the second harmonic components in each of the ultrasonic resonance spectra and the second harmonic components are compared to ascertain the presence of crack-like flaws in the component.

  1. Crack detection using resonant ultrasound spectroscopy

    DOE Patents [OSTI]

    Migliori, A.; Bell, T.M.; Rhodes, G.W.

    1994-10-04

    Method and apparatus are provided for detecting crack-like flaws in components. A plurality of exciting frequencies are generated and applied to a component in a dry condition to obtain a first ultrasonic spectrum of the component. The component is then wet with a selected liquid to penetrate any crack-like flaws in the component. The plurality of exciting frequencies are again applied to the component and a second ultrasonic spectrum of the component is obtained. The wet and dry ultrasonic spectra are then analyzed to determine the second harmonic components in each of the ultrasonic resonance spectra and the second harmonic components are compared to ascertain the presence of crack-like flaws in the component. 5 figs.

  2. Fracture of surface cracks loaded in bending

    SciTech Connect (OSTI)

    Chao, Y.J.; Reuter, W.G.

    1997-12-31

    Theoretical background of the constraint effect in brittle fracture of solids is reviewed. Fracture test data from D6-aC, a high strength steel, using three-point-bend (SE(B)) specimens and surface cracked plate (SC(B)) specimens under bending are presented. It is shown that the SE(B) data has an elevated fracture toughness for increasing a/W, i.e., a crack geometry with a larger T/K corresponds to a higher K{sub c} which is consistent with the theoretical prediction. The fundamental fracture properties, i.e., the critical strain and the critical distance, determined from the SE(B) test data are then applied to the interpretation and prediction of the SC(B) test data. Reasonable agreement is achieved for the crack growth initiation site and the load.

  3. Environmentally assisted cracking of LWR materials.

    SciTech Connect (OSTI)

    Chopra, O. K.; Chung, H. M.; Kassner, T. F.; Park, J. H.; Shack, W. J.; Zhang, J.; Brust, F. W.; Dong, P.

    1997-12-05

    The effect of dissolved oxygen level on fatigue life of austenitic stainless steels is discussed and the results of a detailed study of the effect of the environment on the growth of cracks during fatigue initiation are presented. Initial test results are given for specimens irradiated in the Halden reactor. Impurities introduced by shielded metal arc welding that may affect susceptibility to stress corrosion cracking are described. Results of calculations of residual stresses in core shroud weldments are summarized. Crack growth rates of high-nickel alloys under cyclic loading with R ratios from 0.2-0.95 in water that contains a wide range of dissolved oxygen and hydrogen concentrations at 289 and 320 C are summarized.

  4. Numerical Study Of Melted Particles Crush Metallic Substrates And The Interaction Between Particles And A Plasma Beam In The Thermal Projection Process

    SciTech Connect (OSTI)

    Kriba, Ilhem; Djebaili, A.

    2008-09-23

    Plasma spray processes have been widely used to produce high performance coatings of a wide range of Materials (metallic, non-metallic, ceramics), offering protection from, eg. wear, extreme temperature, chemical attack and environmental corrosion. To obtain good quality coatings, spray parameters must be carefully selected. Due to the large variety in process parameters, it is difficult to optimize the process for each specific coating and substrate combinations. Furthermore modelling the spray process allows a better understanding of the process sequences during thermal spraying. Good agreement of the virtual spraying process with the real coating formation is achieved by modelling the particular process steps. The simulation of coating formation to estimate the process parameters is an important tool to develop new coating structures with defined properties. In this work, the process of plasma sprayed coating has been analyzed by numerical simulation. Commercial code is used to predict the plasma jet characteristics, plasma--particle interaction, and coating formation. Using this model we can obtain coating microstructure and characteristics which form a foundation for further improvement of an advanced ceramic coating build up model.

  5. Vitrification of lead-based paint using thermal spray

    SciTech Connect (OSTI)

    Kumar, A.; Covey, S.W.; Lattimore, J.L.; Boy, J.H.

    1996-12-31

    Lead-based paint (LBP) primers have been used to protect steel structures from corrosion. Abrasive blasting is currently used to remove old LBP. During abrasive blasting a containment structure is required to keep the hazardous lead dust from contaminating air, soil, or water. A thermal spray vitrification (TSV) process to remove LBP was developed. Dried glass powder is melted in the high temperature flame of the thermal spray torch. When the glass strikes the substrate it is molten and reacts with the paint on the substrate. The organic components of the paint are pyrolyzed, while the lead ions are trapped on the surface of glass. The quenching stresses in the glass cause the glass to crack and spall off the substrate. The crumbled glass fragments can be collected and remelted, immobilizing the lead ions within the glass network, thereby preventing leaching. The resulting glass can be disposed of as non-hazardous waste. The process is dust-free, eliminating the need for containment. The volume of residue waste is less than for abrasive blasting and is nonhazardous. The concept and techniques of using the thermal spray vitrification process for the removal and the containment of lead from a section of a bridge containing lead-based paint have been successfully demonstrated.

  6. Ocean Thermal Energy Conversion Basics

    Broader source: Energy.gov [DOE]

    A process called ocean thermal energy conversion (OTEC) uses the heat energy stored in the Earth's oceans to generate electricity.

  7. Reflective cracking of shear keys in multi-beam bridges 

    E-Print Network [OSTI]

    Sharpe, Graeme Peter

    2009-06-02

    strength to resist cracking from vehicular loads, but uneven temperature changes and shrinkage strains cause high tensile stresses in the shear key regions and lead to reflective cracking. The analyses showed the highest stresses were often times near...

  8. Environmentally assisted cracking in light water reactors

    SciTech Connect (OSTI)

    Chopra, O.K.; Chung, H.M.; Gruber, E.E. [and others

    1996-07-01

    This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) from April 1995 to December 1995. Topics that have been investigated include fatigue of carbon and low-alloy steel used in reactor piping and pressure vessels, EAC of Alloy 600 and 690, and irradiation-assisted stress corrosion cracking (IASCC) of Type 304 SS. Fatigue tests were conducted on ferritic steels in water that contained various concentrations of dissolved oxygen (DO) to determine whether a slow strain rate applied during different portions of a tensile-loading cycle are equally effective in decreasing fatigue life. Crack-growth-rate tests were conducted on compact-tension specimens from several heats of Alloys 600 and 690 in simulated LWR environments. Effects of fluoride-ion contamination on susceptibility to intergranular cracking of high- and commercial- purity Type 304 SS specimens from control-tensile tests at 288 degrees Centigrade. Microchemical changes in the specimens were studied by Auger electron spectroscopy and scanning electron microscopy to determine whether trace impurity elements may contribute to IASCC of these materials.

  9. SCATTERING BY CRACKS BENEATH FLUIDSOLID INTERFACES

    E-Print Network [OSTI]

    Craster, Richard

    , and accurately determine the position of, cracks. The non­destructive testing of a solid to detect such flaws as the fluid coupling tends to zero is non­uniform, that is, the Rayleigh wave is not related to the Sch

  10. Digital radiographic systems detect boiler tube cracks

    SciTech Connect (OSTI)

    Walker, S. [EPRI, Charlotte, NC (United States)

    2008-06-15

    Boiler water wall leaks have been a major cause of steam plant forced outages. But conventional nondestructive evaluation techniques have a poor track record of detecting corrosion fatigue cracking on the inside surface of the cold side of waterwall tubing. EPRI is performing field trials of a prototype direct-digital radiographic system that promises to be a game changer. 8 figs.

  11. Stress corrosion cracking and crack tip characterization of Alloy X-750 in light water reactor environments

    E-Print Network [OSTI]

    Gibbs, Jonathan Paul

    2011-01-01

    Stress corrosion cracking (SCC) susceptibility of Inconel Alloy X-750 in the HTH condition has been evaluated in high purity water at 93 and 288°C under Boiling Water Reactor Normal Water Chemistry (NWC) and Hydrogen Water ...

  12. Stress Corrosion Cracking and Crack Tip Characterization of Alloy X-750 in Light Water Reactor Environments

    E-Print Network [OSTI]

    Gibbs, Jonathan Paul

    Stress corrosion cracking (SCC) susceptibility of Inconel Alloy X-750 in the HTH condition has been evaluated in high purity water at 93 and 288°C under Boiling Water Reactor Normal Water Chemistry (NWC) and Hydrogen Water ...

  13. EDDY CURRENT SYSTEM FOR DETECTION OF CRACKING BENEATH BRAIDING IN CORRUGATED METAL HOSE

    SciTech Connect (OSTI)

    Wincheski, Buzz [NASA Langley Research Center, Hampton, VA 23681 (United States); Simpson, John [Lockheed Martin Space Operations, Hampton, VA 23681 (United States); Hall, George [George Washington University, Washington, D.C. 20052 (United States)

    2009-03-03

    In this paper an eddy current system for the detection of partially-through-the-thickness cracks in corrugated metal hose is presented. Design criteria based upon the geometry and conductivity of the part are developed and applied to the fabrication of a prototype inspection system. Experimental data are used to highlight the capabilities of the system and an image processing technique is presented to improve flaw detection capabilities. A case study for detection of cracking damage in a space shuttle radiator retract flex hoses is also presented.

  14. 128 CEREAL CHEMISTRY Effects of Alkali Debranning, Roller Mill Cracking and Gap Setting, and Alkali

    E-Print Network [OSTI]

    . Cracking the pericarp-free corn in a roller mill is done to further reduce kernel size so that steep time fiber, and gluten are separated. This procedure gave a practical compar- able starch yield of 67 was developed for the purpose of obtaining bran-free corn that was further processed into edible corn products

  15. THE INFLUENCE OF THE GRAIN STRUCTURE SIZE ON MICROSTRUCTURALLY SHORT CRACKS

    E-Print Network [OSTI]

    Cizelj, Leon

    ; crystal plasticity ABSTRACT The dominant processes in the initialization and propagation elasticity and crystal plasticity constitutive models are employed at the grain size scale. It is shown& strain rate tensor p kl& plastic strain rate tensoR crack direction ij stress tensor ij& stress rate

  16. Analysis of cracked piezoelectric solids by a mixed three-dimensional BE approach

    E-Print Network [OSTI]

    Ariza Moreno, Pilar

    regularization and evaluation of boundary integrals. Quadratic boundary elements and quarter-point boundary isotropy. Piezoelectric ceramics are used for construction of sensors, transducers, actuators as well, these brittle materials are likely to develop cracks. The under- standing and evaluation of the fracture process

  17. Eddy-current interaction with an ideal crack. II. The inverse problem John FL Bowler

    E-Print Network [OSTI]

    Bowler, John R.

    Eddy-current interaction with an ideal crack. II. The inverse problem John FL Bowler The University 1994) Eddy-current inversion is the process whereby the geometry of a flaw in a metal is derived from eddy-current probe impedance measurements. The approach is based on an optimization scheme that seeks

  18. Stress Corrosion Cracking and Delayed Increase in Penetration Resistance after Dynamic Compaction of Sand

    E-Print Network [OSTI]

    Michalowski, Radoslaw L.

    of Sand R.L. Michalowski1 , F. ASCE and S. S. Nadukuru2 , Student Member, ASCE 1 University of Michigan Engineering, Ann Arbor, MI 48109-2125, U.S.A.; siddu@umich.edu ABSTRACT Dynamically compacted sands exhibit on the process of stress corrosion cracking of the micro-morphological features on the surface of the sand grains

  19. Time-resolved measurement of photon emission during fast crack propagation in three-point bending fracture of silica glass and soda lime glass

    SciTech Connect (OSTI)

    Shiota, Tadashi, E-mail: tshiota@ceram.titech.ac.jp; Sato, Yoshitaka; Yasuda, Kouichi [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1-S7-13 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)] [Department of Metallurgy and Ceramics Science, Tokyo Institute of Technology, 2-12-1-S7-13 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

    2014-03-10

    Simultaneous time-resolved measurements of photon emission (PE) and fast crack propagation upon bending fracture were conducted in silica glass and soda lime glass. Observation of fracture surfaces revealed that macroscopic crack propagation behavior was similar between the silica glass and soda lime glass when fracture loads for these specimens were comparable and cracks propagated without branching. However, a large difference in the PE characteristics was found between the two glasses. In silica glass, PE (645–655?nm) was observed during the entire crack propagation process, whereas intense PE (430–490?nm and 500–600?nm) was observed during the initial stages of propagation. In contrast, only weak PE was detected in soda lime glass. These results show that there is a large difference in the atomic processes involved in fast crack propagation between these glasses, and that PE can be used to study brittle fracture on the atomic scale.

  20. Thermal spray removal of lead-based paint from the viaduct bridge at Rock Island Arsenal, IL. Final report

    SciTech Connect (OSTI)

    Boy, J.H.; Weber, R.A.; Kumar, A.

    1998-06-01

    This report documents a field demonstration at the Rock Island Arsenal, IL, that validated the thermal spray vitrification (TSV) process as a safe and effective technique for removing lead-based paint from a steel bridge. Specially formulated glass was applied in a molten state to painted steel using a conventional thermal spray application system. The molten glass reacts with the paint, and encapsulates the lead. The cooled glass readily cracks and falls off, removing the paint. After onsite remelting of the glass waste to complete the encapsulation process, the final waste product is chemically inert and may be disposed of in a regular landfill. The Illinois Environmental Protection Agency, Division of Air Pollution Control determined that the glass remelt process could be considered a paint-removal operation for which no air quality permit was required.

  1. Thermal Integration of CO{sub 2} Compression Processes with Coal-Fired Power Plants Equipped with Carbon Capture

    SciTech Connect (OSTI)

    Edward Levy

    2012-06-29

    Coal-fired power plants, equipped either with oxycombustion or post-combustion CO{sub 2} capture, will require a CO{sub 2} compression system to increase the pressure of the CO{sub 2} to the level needed for sequestration. Most analyses show that CO{sub 2} compression will have a significant effect on parasitic load, will be a major capital cost, and will contribute significantly to reduced unit efficiency. This project used first principle engineering analyses and computer simulations to determine the effects of utilizing compressor waste heat to improve power plant efficiency and increase net power output of coal-fired power plants with carbon capture. This was done for units with post combustion solvent-based CO{sub 2} capture systems and for oxyfired power plants, firing bituminous, PRB and lignite coals. The thermal integration opportunities analyzed for oxycombustion capture are use of compressor waste heat to reheat recirculated flue gas, preheat boiler feedwater and predry high-moisture coals prior to pulverizing the coal. Among the thermal integration opportunities analyzed for post combustion capture systems are use of compressor waste heat and heat recovered from the stripper condenser to regenerate post-combustion CO{sub 2} capture solvent, preheat boiler feedwater and predry high-moisture coals. The overall conclusion from the oxyfuel simulations is that thermal integration of compressor heat has the potential to improve net unit heat rate by up to 8.4 percent, but the actual magnitude of the improvement will depend on the type of heat sink used and to a lesser extent, compressor design and coal rank. The simulations of a unit with a MEA post combustion capture system showed that thermal integration of either compressor heat or stripper condenser heat to preheat boiler feedwater would result in heat rate improvements from 1.20 percent to 4.19 percent. The MEA capture simulations further showed that partial drying of low rank coals, done in combination with feedwater heating, would result in heat rate reductions of 7.43 percent for PRB coal and 10.45 percent for lignite.

  2. Computer code in support of the manuscript "Phase field model for coupled displacive and diffusive microstructural processes under thermal loading"

    E-Print Network [OSTI]

    Wells, G N; Maraldi, Mirko

    2011-01-01

    stream_source_info heat_treatment_solver.py.txt stream_content_type text/plain stream_size 14746 Content-Encoding ISO-8859-1 stream_name heat_treatment_solver.py.txt Content-Type text/plain; charset=ISO-8859-1 """This... T = 2.0e-2 # thermal conductivity delta = case_data['delta'] # heat boundary flux coefficient T_ext = case_data['T_ext'] # external temperature # Mechanical parameters rho = 5.0e-7 # solid mass density eta = 5.0e-8 # viscous stress parameter # Mass...

  3. Liquid Salts as Media for Process Heat Transfer from VHTR's: Forced Convective Channel Flow Thermal Hydraulics, Materials, and Coating

    SciTech Connect (OSTI)

    Sridharan, Kumar; Anderson, Mark; Allen, Todd; Corradini, Michael

    2012-01-30

    The goal of this NERI project was to perform research on high temperature fluoride and chloride molten salts towards the long-term goal of using these salts for transferring process heat from high temperature nuclear reactor to operation of hydrogen production and chemical plants. Specifically, the research focuses on corrosion of materials in molten salts, which continues to be one of the most significant challenges in molten salts systems. Based on the earlier work performed at ORNL on salt properties for heat transfer applications, a eutectic fluoride salt FLiNaK (46.5% LiF-11.5%NaF-42.0%KF, mol.%) and a eutectic chloride salt (32%MgCl2-68%KCl, mole %) were selected for this study. Several high temperature candidate Fe-Ni-Cr and Ni-Cr alloys: Hastelloy-N, Hastelloy-X, Haynes-230, Inconel-617, and Incoloy-800H, were exposed to molten FLiNaK with the goal of understanding corrosion mechanisms and ranking these alloys for their suitability for molten fluoride salt heat exchanger and thermal storage applications. The tests were performed at 850��������C for 500 h in sealed graphite crucibles under an argon cover gas. Corrosion was noted to occur predominantly from dealloying of Cr from the alloys, an effect that was particularly pronounced at the grain boundaries Alloy weight-loss due to molten fluoride salt exposure correlated with the initial Cr-content of the alloys, and was consistent with the Cr-content measured in the salts after corrosion tests. The alloys���¢�������� weight-loss was also found to correlate to the concentration of carbon present for the nominally 20% Cr containing alloys, due to the formation of chromium carbide phases at the grain boundaries. Experiments involving molten salt exposures of Incoloy-800H in Incoloy-800H crucibles under an argon cover gas showed a significantly lower corrosion for this alloy than when tested in a graphite crucible. Graphite significantly accelerated alloy corrosion due to the reduction of Cr from solution by graphite and formation on Cr-carbide on the graphite surface. Ni-electroplating dramatically reduced corrosion of alloys, although some diffusion of Fe and Cr were observed occur through the Ni plating. A pyrolytic carbon and SiC (PyC/SiC) CVD coating was also investigated and found to be effective in mitigating corrosion. The KCl-MgCl2 molten salt was less corrosive than FLiNaK fluoride salts for corrosion tests performed at 850oC. Cr dissolution in the molten chloride salt was still observed and consequently Ni-201 and Hastelloy N exhibited the least depth of attack. Grain-boundary engineering (GBE) of Incoloy 800H improved the corrosion resistance (as measured by weight loss and maximum depth of attack) by nearly 50% as compared to the as-received Incoloy 800H sample. Because Cr dissolution is an important mechanism of corrosion, molten salt electrochemistry experiments were initiated. These experiments were performed using anodic stripping voltammetry (ASV). Using this technique, the reduction potential of Cr was determined against a Pt quasi-reference electrode as well as against a Ni(II)-Ni reference electrode in molten FLiNaK at 650 oC. The integrated current increased linearly with Cr-content in the salt, providing for a direct assessment of the Cr concentration in a given salt of unknown Cr concentration. To study heat transfer mechanisms in these molten salts over the forced and mixed convection regimes, a forced convective loop was constructed to measure heat transfer coefficients, friction factors and corrosion rates in different diameter tubes in a vertical up flow configuration in the laminar flow regime. Equipment and instrumentation for the forced convective loop was designed, constructed, and tested. These include a high temperature centrifugal pump, mass flow meter, and differential pressure sensing capabilities to an uncertainty of < 2 Pa. The heat transfer coefficient for the KCl-MgCl2 salt was measured in t

  4. Low Thermal Conductivity, High Durability Thermal Barrier Coatings for IGCC Environments

    SciTech Connect (OSTI)

    Jordan, Eric; Gell, Maurice

    2015-01-15

    Advanced thermal barrier coatings (TBC) are crucial to improved energy efficiency in next generation gas turbine engines. The use of traditional topcoat materials, e.g. yttria-stabilized zirconia (YSZ), is limited at elevated temperatures due to (1) the accelerated undesirable phase transformations and (2) corrosive attacks by calcium-magnesium-aluminum-silicate (CMAS) deposits and moisture. The first goal of this project is to use the Solution Precursor Plasma Spray (SPPS) process to further reduce the thermal conductivity of YSZ TBCs by introducing a unique microstructural feature of layered porosity, called inter-pass boundaries (IPBs). Extensive process optimization accompanied with hundreds of spray trials as well as associated SEM cross-section and laser-flash measurements, yielded a thermal conductivity as low as 0.62 Wm?ąK?ą in SPPS YSZ TBCs, approximately 50% reduction of APS TBCs; while other engine critical properties, such as cyclic durability, erosion resistance and sintering resistance, were characterized to be equivalent or better than APS baselines. In addition, modifications were introduced to SPPS TBCs so as to enhance their resistance to CMAS under harsh IGCC environments. Several mitigation approaches were explored, including doping the coatings with Al?O? and TiO?, applying a CMAS infiltration-inhibiting surface layer, and filling topcoat cracks with blocking substances. The efficacy of all these modifications was assessed with a set of novel CMAS-TBC interaction tests, and the moisture resistance was tested in a custom-built high-temperature moisture rig. In the end, the optimal low thermal conductivity TBC system was selected based on all evaluation tests and its processing conditions were documented. The optimal coating consisted on a thick inner layer of YSZ coating made by the SPPS process having a thermal conductivity 50% lower than standard YSZ coatings topped with a high temperature tolerant CMAS resistant gadolinium zirconate Coating made by the SPPS process. Noteworthy was the fact that the YSZ to GZO interface made by the SPPS process was not the failure location as had been observed in APS coatings.

  5. Soil cracking modelling using the mesh-free SPH method

    E-Print Network [OSTI]

    Bui, H H; Kodikara, J; Sanchez, M

    2015-01-01

    The presence of desiccation cracks in soils can significantly alter their mechanical and hydrological properties. In many circumstances, desiccation cracking in soils can cause significant damage to earthen or soil supported structures. For example, desiccation cracks can act as the preference path way for water flow, which can facilitate seepage flow causing internal erosion inside earth structures. Desiccation cracks can also trigger slope failures and landslides. Therefore, developing a computational procedure to predict desiccation cracking behaviour in soils is vital for dealing with key issues relevant to a range of applications in geotechnical and geo-environment engineering. In this paper, the smoothed particle hydrodynamics (SPH) method will be extended for the first time to simulate shrinkage-induced soil cracking. The main objective of this work is to examine the performance of the proposed numerical approach in simulating the strong discontinuity in material behaviour and to learn about the crack ...

  6. IDENTIFICATION OF AN {sup 84}Sr-DEPLETED CARRIER IN PRIMITIVE METEORITES AND IMPLICATIONS FOR THERMAL PROCESSING IN THE SOLAR PROTOPLANETARY DISK

    SciTech Connect (OSTI)

    Paton, Chad; Schiller, Martin; Bizzarro, Martin E-mail: schiller@snm.ku.dk

    2013-02-01

    The existence of correlated nucleosynthetic heterogeneities in solar system reservoirs is now well demonstrated for numerous nuclides. However, it has proven difficult to discriminate between the two disparate processes that can explain such correlated variability: incomplete mixing of presolar material or secondary processing of a well-mixed disk. Using stepwise acid-leaching of the Ivuna CI-chondrite, we show that unlike other nuclides such as {sup 54}Cr and {sup 50}Ti, Sr-isotope variability is the result of a carrier depleted in {sup 84}Sr. The carrier is most likely presolar SiC, which is known to have both high Sr-concentrations relative to solar abundances and extremely depleted {sup 84}Sr compositions. Thus, variability in {sup 84}Sr in meteorites and their components can be attributed to varying contributions from presolar SiC. The observed {sup 84}Sr excesses in calcium-aluminum refractory inclusions (CAIs) suggest their formation from an SiC-free gaseous reservoir, whereas the {sup 84}Sr depletions present in differentiated meteorites require their formation from material with an increased concentration of SiC relative to CI chondrites. The presence of a positive correlation between {sup 84}Sr and {sup 54}Cr, despite being hosted in carriers of negative and positive anomalies, respectively, is not compatible with incomplete mixing of presolar material but instead suggests that the solar system's nucleosynthetic heterogeneity reflects selective thermal processing of dust. Based on vaporization experiments of SiC under nebular conditions, the lack of SiC material in the CAI-forming gas inferred from our data requires that the duration of thermal processing of dust resulting in the vaporization of CAI precursors was extremely short-lived, possibly lasting only hours to days.

  7. Circumferential cracking of steam generator tubes

    SciTech Connect (OSTI)

    Karwoski, K.J.

    1997-04-01

    On April 28, 1995, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 95-03, {open_quote}Circumferential Cracking of Steam Generator Tubes.{close_quote} GL 95-03 was issued to obtain information needed to verify licensee compliance with existing regulatory requirements regarding the integrity of steam generator tubes in domestic pressurized-water reactors (PWRs). This report briefly describes the design and function of domestic steam generators and summarizes the staff`s assessment of the responses to GL 95-03. The report concludes with several observations related to steam generator operating experience. This report is intended to be representative of significant operating experience pertaining to circumferential cracking of steam generator tubes from April 1995 through December 1996. Operating experience prior to April 1995 is discussed throughout the report, as necessary, for completeness.

  8. Dynamical Event during Slow Crack Propagation

    SciTech Connect (OSTI)

    Ma {sup o}loy, Knut Jorgen; Schmittbuhl, Jean

    2001-09-03

    We address the role of material heterogeneities on the propagation of a slow rupture at laboratory scale. With a high speed camera, we follow an in-plane crack front during its propagation through a transparent heterogeneous Plexiglas block. We obtain two major results. First, the slip along the interface is strongly correlated over scales much larger than the asperity sizes. Second, the dynamics is scale dependent. Locally, mechanical instabilities are triggered during asperity depinning and propagate along the front. The intermittent behavior at the asperity scale is in contrast with the large scale smooth creeping evolution of the average crack position. The dynamics is described on the basis of a Family-Vicsek scaling.

  9. Process of welding gamma prime-strengthened nickel-base superalloys

    DOE Patents [OSTI]

    Speigel, Lyle B.; White, Raymond Alan; Murphy, John Thomas; Nowak, Daniel Anthony

    2003-11-25

    A process for welding superalloys, and particularly articles formed of gamma prime-strengthened nickel-base superalloys whose chemistries and/or microstructures differ. The process entails forming the faying surface of at least one of the articles to have a cladding layer of a filler material. The filler material may have a composition that is different from both of the articles, or the same as one of the articles. The cladding layer is machined to promote mating of the faying surfaces, after which the faying surfaces are mated and the articles welded together. After cooling, the welded assembly is free of thermally-induced cracks.

  10. The effects of thermal processing on properties of fundamental food polymers in commercial Asian and experimental sorghum noodles 

    E-Print Network [OSTI]

    Leach, Michelle R

    2013-02-22

    Processing variables of 100% sorghum noodles were evaluated. A dough was made, extruded to create noodles then dried. Structural, physical, and cooking characteristics of the experimental sorghum noodles, as well as thin ...

  11. Nanoparticulate-catalyzed oxygen transfer processes

    DOE Patents [OSTI]

    Hunt, Andrew T. (Atlanta, GA); Breitkopf, Richard C. (Dunwoody, GA)

    2009-12-01

    Nanoparticulates of oxygen transfer materials that are oxides of rare earth metals, combinations of rare earth metals, and combinations of transition metals and rare earth metals are used as catalysts in a variety of processes. Unexpectedly large thermal efficiencies are achieved relative to micron sized particulates. Processes that use these catalysts are exemplified in a multistage reactor. The exemplified reactor cracks C6 to C20 hydrocarbons, desulfurizes the hydrocarbon stream and reforms the hydrocarbons in the stream to produce hydrogen. In a first reactor stage the steam and hydrocarbon are passed through particulate mixed rare earth metal oxide to crack larger hydrocarbon molecules. In a second stage, the steam and hydrocarbon are passed through particulate material that desulfurizes the hydrocarbon. In a third stage, the hydrocarbon and steam are passed through a heated, mixed transition metal/rare earth metal oxide to reform the lower hydrocarbons and thereby produce hydrogen. Stages can be alone or combined. Parallel reactors can provide continuous reactant flow. Each of the processes can be carried out individually.

  12. Technical Letter Report on the Cracking of Irradiated Cast Stainless Steels with Low Ferrite Content

    SciTech Connect (OSTI)

    Chen, Y.; Alexandreanu, B.; Natesan, K.

    2014-11-01

    Crack growth rate and fracture toughness J-R curve tests were performed on CF-3 and CF-8 cast austenite stainless steels (CASS) with 13-14% of ferrite. The tests were conducted at ~320°C in either high-purity water with low dissolved oxygen or in simulated PWR water. The cyclic crack growth rates of CF-8 were higher than that of CF-3, and the differences between the aged and unaged specimens were small. No elevated SCC susceptibility was observed among these samples, and the SCC CGRs of these materials were comparable to those of CASS alloys with >23% ferrite. The fracture toughness values of unirradiated CF-3 were similar between unaged and aged specimens, and neutron irradiation decreased the fracture toughness significantly. The fracture toughness of CF-8 was reduced after thermal aging, and declined further after irradiation. It appears that while lowering ferrite content may help reduce the tendency of thermal aging embrittlement, it is not very effective to mitigate irradiation-induced embrittlement. Under a combined condition of thermal aging and irradiation, neutron irradiation plays a dominant role in causing embrittlement in CASS alloys.

  13. Thermal cycling tests on surface-mount assemblies

    SciTech Connect (OSTI)

    Jennings, C.W.

    1988-03-01

    The capability of surface-mount (SM) solder joints to withstand various thermal cycle stresses was evaluated through electrical circuit resistance changes of a test pattern and by visual examination for cracks in the solder after exposure to thermal cycling. The joints connected different electrical components, primarily leadless-chip carriers (LCCs), and printed wiring-board (PWB) pads on different laminate substrates. Laminate compositions were epoxy-glass and polyimide-glass with and without copper/Invar/copper (CIC) inner layers, polyimide-quartz, epoxy-Kevlar, and polyimide-Kevlar. The most resistant joints were between small LCCs (24 and 48 pins) and polyimide-glass laminate with CIC inner layers. Processing in joint formation was found to be an important part of joint resistant. Thermal cycling was varied with respect to both time and temperature. A few resistors, capacitors, and inductors showed opens after 500 30-min cycles between -65/degree/C and 125/degree/C. Appreciable moisture contents were measured for laminate materials, especially those of polyimide-Kevlar after equilibration in 100/percent/ relative humidity at room temperature. If not removed or reduced, moisture can cause delamination in vapor-phase soldering. 17 refs, 12 figs.,10 tabs.

  14. Hot Rolling Scrap Reduction through Edge Cracking and Surface...

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

    Our Approach use a precompetitive material to develop new modeling technology (AA-7050) account for the anisotropic behavior during crack growth. validate model to...

  15. Thermal radiation Ron Zevenhoven

    E-Print Network [OSTI]

    Zevenhoven, Ron

    .00032, similarly for 2·T = 0.7·2500 = 1750 µmK4 this gives f0-2 = 0.03392. Thus for 0.4 - 0.7 µm, f1-2 = 0Thermal radiation revisited Ron Zevenhoven Ĺbo Akademi University Thermal and Flow Engineering Laboratory / Värme- och strömningsteknik tel. 3223 ; ron.zevenhoven@abo.fi Process Engineering

  16. Shrinkage - cracking characteristics of structural lightweight concrete 

    E-Print Network [OSTI]

    McKeen, Robert Gordon

    1969-01-01

    restraint of the material, such as reinforcement and external fri. ction 28 (h) chemical admixtures employed (i) unit water content 2. 4 ~fk' f. C 2. 4. 1 General The cracking of concrete has been a subject of interest to desi. gners for many years... were made on two six by t. )elve in. c; linders from each batch of concrete for purposes of control. . The pecimens were moist cured 14 days prior to testing. Testing was performed in accordance with ASTM C39-64. The data were taken to provid...

  17. 3:2:1 Crack Spread

    Gasoline and Diesel Fuel Update (EIA)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of Natural GasAdjustments (Billion Cubic Feet) Wyoming Dry NaturalPrices1 Table 1.10 CoolingNotes &* j o n5 1:2:1 Crack

  18. Soft ionization of thermally evaporated hypergolic ionic liquid aerosols

    E-Print Network [OSTI]

    Koh, Christine J.

    2013-01-01

    thermal energy from evaporation and the energy imparted by the ionization process.energy imparted into the isolated ion pair upon thermal vaporization and minimizes reactive processes.

  19. Advances in Hydrogen Isotope Separation Using Thermal Cycling...

    Office of Environmental Management (EM)

    Hydrogen Isotope Separation Using Thermal Cycling Absorption Process (TCAP) Advances in Hydrogen Isotope Separation Using Thermal Cycling Absorption Process (TCAP) Presentation...

  20. Radiation-induced instability of MnS precipitates and its possible consequences on irradiation-induced stress corrosion cracking of austenitic stainless steels

    SciTech Connect (OSTI)

    Chung, H.M.; Sanecki, J.E.; Garner, F.A.

    1996-12-01

    Irradiation-assisted stress corrosion cracking (IASCC) is a significant materials issue for the light water reactor (LWR) industry and may also pose a problem for fusion power reactors that will use water as coolant. A new metallurgical process is proposed that involves the radiation-induced release into solution of minor impurity elements not usually thought to participate in IASCC. MnS-type precipitates, which contain most of the sulfur in stainless steels, are thought to be unstable under irradiation. First, Mn transmutes strongly to Fe in thermalized neutron spectra. Second, cascade-induced disordering and the inverse Kirkendall effect operating at the incoherent interfaces of MnS precipitates are thought to act as a pump to export Mn from the precipitate into the alloy matrix. Both of these processes will most likely allow sulfur, which is known to exert a deleterious influence on intergranular cracking, to re-enter the matrix. To test this hypothesis, compositions of MnS-type precipitates contained in several unirradiated and irradiated heats of Type 304, 316, and 348 stainless steels (SSs) were analyzed by Auger electron spectroscopy. Evidence is presented that shows a progressive compositional modification of MnS precipitates as exposure to neutrons increases in boiling water reactors. As the fluence increases, the Mn level in MnS decreases, whereas the Fe level increases. The S level also decreases relative to the combined level of Mn and Fe. MnS precipitates were also found to be a reservoir of other deleterious impurities such as F and O which could be also released due to radiation-induced instability of the precipitates.

  1. Thermal, tensile and rheological properties of high density polyethylene (HDPE) processed and irradiated by gamma-ray in different atmospheres

    SciTech Connect (OSTI)

    Ferreto, H. F. R. E-mail: ana-feitoza@yahoo.com.br; Oliveira, A. C. F. E-mail: ana-feitoza@yahoo.com.br; Parra, D. F. E-mail: ablugao@ipen.br; Lugăo, A. B. E-mail: ablugao@ipen.br; Gaia, R.

    2014-05-15

    The aim of this paper is to investigate structural changes of high density polyethylene (HDPE) modified by ionizing radiation (gamma rays) in different atmospheres. The gamma radiation process for modification of commercial polymers is a widely applied technique to promote new physical-chemical and mechanical properties. Gamma irradiation originates free radicals which can induce chain scission or recombination, providing its annihilation, branching or crosslinking. This polymer was irradiated with gamma source of {sup 60}Co at doses of 5, 10, 20, 50 or 100 kGy at a dose rate of 5 kGy/h. The changes in molecular structure of HDPE, after gamma irradiations were evaluated using thermogravimetric analysis (TGA) and tensile machine and oscillatory rheology. The results showed the variations of the properties depending on the dose at each atmosphere.

  2. Composite tube cracking in kraft recovery boilers: A state-of-the-art review

    SciTech Connect (OSTI)

    Singbeil, D.L.; Prescott, R.; Keiser, J.R.; Swindeman, R.W.

    1997-07-01

    Beginning in the mid-1960s, increasing energy costs in Finland and Sweden made energy recovery more critical to the cost-effective operation of a kraft pulp mill. Boiler designers responded to this need by raising the steam operating pressure, but almost immediately the wall tubes in these new boilers began to corrode rapidly. Test panels installed in the walls of the most severely corroding boiler identified austenitic stainless steel as sufficiently resistant to the new corrosive conditions, and discussions with Sandvik AB, a Swedish tube manufacturer, led to the suggestion that coextruded tubes be used for water wall service in kraft recovery boilers. Replacement of carbon steel by coextruded tubes has solved most of the corrosion problems experienced by carbon steel wall tubes, however, these tubes have not been problem-free. Beginning in early 1995, a multidisciplinary research program funded by the US Department of Energy was established to investigate the cause of cracking in coextruded tubes and to develop improved materials for use in water walls and floors of kraft recovery boilers. One portion of that program, a state-of-the-art review of public- and private-domain documents related to coextruded tube cracking in kraft recovery boilers is reported here. Sources of information that were consulted for this review include the following: tube manufacturers, boiler manufacturers, public-domain literature, companies operating kraft recovery boilers, consultants and failure analysis laboratories, and failure analyses conducted specifically for this project. Much of the information contained in this report involves cracking problems experienced in recovery boiler floors and those aspects of spout and air-port-opening cracking not readily attributable to thermal fatigue. 61 refs.

  3. Syngas Production from Propane Using Atmospheric Non-thermal Plasma

    E-Print Network [OSTI]

    Ouni, Fakhreddine; Cormier, Jean Marie; 10.1007/s11090-009-9166-2

    2009-01-01

    Propane steam reforming using a sliding discharge reactor was investigated under atmospheric pressure and low temperature (420 K). Non-thermal plasma steam reforming proceeded efficiently and hydrogen was formed as a main product (H2 concentration up to 50%). By-products (C2-hydrocarbons, methane, carbon dioxide) were measured with concentrations lower than 6%. The mean electrical power injected in the discharge is less than 2 kW. The process efficiency is described in terms of propane conversion rate, steam reforming and cracking selectivity, as well as by-products production. Chemical processes modelling based on classical thermodynamic equilibrium reactor is also proposed. Calculated data fit quiet well experimental results and indicate that the improvement of C3H8 conversion and then H2 production can be achieved by increasing the gas fraction through the discharge. By improving the reactor design, the non-thermal plasma has a potential for being an effective way for supplying hydrogen or synthesis gas.

  4. Experimental Determination of Crack Driving Forces in Integrated Structures

    E-Print Network [OSTI]

    Suo, Zhigang

    8/2/2004 1 Experimental Determination of Crack Driving Forces in Integrated Structures Jun He in a structure, the crack driving force G is the reduction of the elastic energy in the structure, associated. In practice, however, such a calculation is prohibitively difficult for integrated structures of complex

  5. Crack patterns in thin lms Z. Cedric Xiaa

    E-Print Network [OSTI]

    Hutchinson, John W.

    Crack patterns in thin ®lms Z. Cedric Xiaa , John W. Hutchinsonb, * a Ford Research Laboratory elastic ®lms. Speci®c examples are presented for ®lms subject to equi-biaxial residual tensile stress Elsevier Science Ltd. All rights reserved. Keywords: Crack propagation; Thin ®lms; Integral equations 1

  6. Fracture mechanics analysis of slow crack growth in polyethylene 

    E-Print Network [OSTI]

    Self, Robert Alan

    1997-01-01

    Slow crack growth in polyethylene is often the limiting factor in long-term service of plastic pipe or other structural applications. A new test method and analysis method was developed to study slow crack growth in polyethylene. Two high density...

  7. WATER PERMEABILITY OF CRACKED CEMENTITIOUS MICHAEL LEPECH & VICTOR C. LI

    E-Print Network [OSTI]

    Lepech, Michael D.

    of ECC material exhibits a water permeability close to that of uncracked concrete when strained up to 1 structures. With compressive strengths twice that of normal concrete and a low water permeability coefficient is the permeability of concrete structures in the cracked state. Regardless of the reason for cracking, whether

  8. CRACKING OF PRESTRESSED CONCRETE CONTAINMENTS DUE TO INTERNAL PRESSURE

    E-Print Network [OSTI]

    applied to a 1/14 scale test structure. Observed values agreed well with predicted values. #12;Mac of a containment vessel (wall segment tests) reported in this paper and Ref. 4 and 5, and a test of a 1/14 size reached, all cracks observed in the tests had formed. At greater strains certain existing cracks became

  9. The Simulation of Paint Cracking and Peeling Eric Paquette

    E-Print Network [OSTI]

    Montréal, Université de

    The Simulation of Paint Cracking and Peeling Eric Paquette D´ep. I.R.O., Universit´e de Montr of time results in cracking and peeling of layers such as paint. To include these ef- fects in computer of paint peeling. We present a new approach which computes such a simulation on surfaces. Our simulation

  10. Predicting crack growth in continuous-fiber composite materials

    SciTech Connect (OSTI)

    Cordes, J.A.; Yazici, R.

    1995-12-31

    Pre-notched composite lamina with unidirectional fibers were studied experimentally and using finite element analysis. Experiments were conducted on notched graphite/aluminum and glass/epoxy panels and the results were compared to a finite element method. Under remote tensile loading, cracks in the graphite/aluminum panels propagated perpendicular to the applied load without stable crack growth. In the glass/epoxy panels, crack propagation was initially stable and parallel to the fibers. A nonlinear damage zone method (DZM) was used to predict the crack growth directions, estimate damages, model stable and unstable crack growths, and predict the loads at failure. For both materials, the predicted loads at failure were within 20% of experimental loads.

  11. ffe1098 FFE March 7, 2007 21:55 Crack tip displacements of microstructurally small cracks in 316L steel

    E-Print Network [OSTI]

    Cizelj, Leon

    -strain finite element crystal plasticity model. The model consists of 212 randomly shaped, sized and oriented plane. Keywords crack tip displacements; crystal plasticity; polycrystals; small cracks. NOMENCLATURE a) and sliding displacements (CTSD) for single crystal and polycrystal models, considering also different

  12. The effect of crack surface interaction on the stress intensity factor in Mode III crack growth in round shafts

    E-Print Network [OSTI]

    Vaziri, Ashkan

    in round shafts A. Vaziri 1 , H. Nayeb-Hashemi * Department of Mechanical, Industrial and Manufacturing March 2004; accepted 31 March 2004 Available online 6 July 2004 Abstract Turbine-generator shafts and propagate a circumferential crack in the shafts. Mode III crack growth in turbo-generator shafts often

  13. Mixed-mode, high-cycle fatigue-crack growth thresholds in II. Quantication of crack-tip shielding

    E-Print Network [OSTI]

    Ritchie, Robert

    -tip shielding J.P. Campbell, R.O. Ritchie * Department of Materials Science and Mineral Engineering, University 2000; accepted 11 May 2000 Abstract The role of crack-tip shielding in inŻuencing mixed-mode (mode I crack-tip shielding with respect to both the mode I and mode II applied loading, enabling an estimation

  14. Short and Large Crack, Mixed-Mode Fatigue-Crack Growth Thresholds in Ti-6Al-4V1

    E-Print Network [OSTI]

    Ritchie, Robert

    and control of failures due to high cycle fatigue (HCF) in turbine engine components is currently one, Dr. J. P. Campbell and Professor R. O. Ritchie2 Department of Materials Science and Engineering-crack growth thresholds with crack size and shape are reported for a Ti-6Al-4V turbine blade alloy, heat

  15. Acid-catalyzed cracking of paraffinic hydrocarbons. 3. Evidence for the protonated cyclopropane mechanism from hydrocracking/hydroisomerization experiments

    SciTech Connect (OSTI)

    Tiong Sie, S. (Koninklijke/Shell-Lab., Amsterdam (Netherlands))

    1993-03-01

    The mechanism for acid-catalyzed cracking proposed in the first paper of this series, which assumes a protonated dialkylcyclopropane carbonium ion as intermediate instead of a classical carbenium ion, has been applied to rationalize experimental results obtained in the hydrocracking/hydroisomerization of normal paraffins. The new mechanism is shown to be capable of explaining many characteristics of the hydrocracking process which cannot be understood via the classical theory, such as the virtual absence of methane and ethane as cracked products, the relatively low production of propane as compared to the higher hydrocarbons, and characteristic patterns in the branching of the cracked fragments. The new mechanism also makes it clear why crackability increases so rapidly with increasing number of carbon atoms above n-heptane and why n-hexane and lower hydrocarbons are so difficult to crack. An explanation is also offered for the ease with which high selectivities can be achieved in the isomerization of C[sub 5]/C[sub 6], as contrasted with the difficulty of isomerizing C[sub 7+] without significant cracking.

  16. In-Line Crack and Stress Detection in Silicon Solar Cells Using Resonance Ultrasonic Vibrations

    SciTech Connect (OSTI)

    Ostapenko, Sergei

    2013-04-03

    Statement of Problem and Objectives. Wafer breakage in automated solar cell production lines is identified as a major technical problem and a barrier for further cost reduction of silicon solar module manufacturing. To the best of our knowledge, there are no commercial systems addressing critical needs for in-line inspection of the mechanical quality of solar wafers and cells. The principal objective of the SBIR program is to validate through experiments and computer modeling the applicability of the Resonance Ultrasonic Vibrations system, which ultimately can be used as a real-time in-line manufacturing quality control tool for fast detection of mechanically unstable silicon solar cells caused by cracks. The specific objective of Phase II is to move the technology of in-line crack detection from the laboratory level to commercial demonstration through development of a system prototype. The fragility of silicon wafers possessing low mechanical strength is attributed to peripheral and bulk millimeter-length cracks. The research program is based on feasibility results obtained during Phase I, which established that: (i) the Resonance Ultrasonic Vibrations method is applicable to as-cut, processed wafers and finished cells; (ii) the method sensitivity depends on the specific processing step; it is highest in as-cut wafers and lowest in wafers with metallization pattern and grid contacts; (iii) the system is capable of matching the 2.0 seconds per wafer throughput rate of state-of-art solar cell production lines; (iv) finite element modeling provides vibration mode analysis along with peak shift versus crack length and crack location dependence; (v) a high 91% crack rejection rate was confirmed through experimentation and statistical analysis. The Phase II project has the following specific tasks: (i) specify optimal configurations of the in-line system�¢����s component hardware and software; (ii) develop and justify a system prototype that meets major specifications for an in-line crack detection unit, such as high throughput rate, high level of stability, reproducibility of data acquisition and analysis, and high sensitivity with respect to crack length and crack location; (iii) design a system platform that allows easy integration within and adaptation to various solar cell belt-type production lines; (iv) develop a testing protocol providing quality certification of the production-grade system. Commercial Application of the proposed activity consists of bringing to the solar market a new high-tech product based on an innovative solution and patented methodology to contribute to cost reduction of silicon solar module production. The solar industry, with crystalline silicon as a dominant segment, shows outstanding performance, with approximately 25% yearly growth during the last years. Despite a slowdown with only 5.6 GW installations in 2009, solar module production for the 2010 and 2011 years was recovered. According to European Photonics Industry Consortium new solar PV installations grow by 56% compared to 2010 reached 64.7 GW in 2011. Revenues in the PV industry reached a record high of $93 billion in 2011, a 13.4 percent gain over 2010 â�� and 150 percent over 2009. This growth was forecasted to continue in 2013 with double digits growth. The solar industry is economically driven to make solar panels of the highest conversion efficiency and reliability at the lowest production cost. The Resonance Ultrasonic Vibration system addresses critical needs of the silicon-based solar industry by providing a quality control method and tool, which will improve productivity, increase reliability of products and reduce manufacturing cost of solar panels.

  17. THERMALLY ACTIVATED MARTENSITE: ITS RELATIONSHIP TO NON-THERMALLY ACTIVATED (ATHERMAL) MARTENSITE

    E-Print Network [OSTI]

    Laughlin, David E.

    THERMALLY ACTIVATED MARTENSITE: ITS RELATIONSHIP TO NON-THERMALLY ACTIVATED (ATHERMAL) MARTENSITE Keywords: Thermal Activation, Isothermal, Athermal, Activation Energy Abstract The classification of no thermal activation. Processes with no thermal activation do not depend on time, as there is no need

  18. Room-temperature thermally induced relaxation effect in a two-dimensional cyano-bridged Cu-Mo bimetal assembly and thermodynamic analysis of the relaxation process

    SciTech Connect (OSTI)

    Umeta, Yoshikazu; Ozaki, Noriaki; Tokoro, Hiroko; Ohkoshi, Shin-ichi

    2013-04-15

    We observed a photo-switching effect in [Cu{sup II}(1,4,8,11-tetraazacyclodecane)]{sub 2}[Mo{sup IV}(CN){sub 8}]{center_dot}10H{sub 2}O by irradiation with 410-nm light around room temperature using infrared spectroscopy. This photo-switching is caused by the photo-induced charge transfer from Mo{sup IV} to Cu{sup II}. The photo-induced phase thermally relaxed to the initial phase with a half-life time of 2.7 Multiplication-Sign 10{sup 1}, 6.9 Multiplication-Sign 10{sup 1}, and 1.7 Multiplication-Sign 10{sup 2} s at 293, 283, and 273 K, respectively. The relaxation process was analyzed using Hauser's equation, k=k{sub 0}exp[-(E{sub a}+E{sub a}{sup *}{gamma}) /k{sub B}T], where k is the rate constant of relaxation, k{sub 0} is the frequency factor, E{sub a} is the activation energy, E{sub a}{sup *} is the additional activation energy due to the cooperativity, and {gamma} is the fraction of the photo-induced phase. k{sub 0}, E{sub a}, and E{sub a}{sup *} were evaluated as 1.28 Multiplication-Sign 10{sup 7}{+-} 2.6 s{sup -1}, 4002 {+-} 188 cm{sup -1}, and 546 {+-} 318 cm{sup -1}, respectively. The value of E{sub a} is much larger than that of the relaxation process for the typical light-induced spin crossover effect (E{sub a} Almost-Equal-To 1000 cm{sup -1}). Room-temperature photo-switching is an important issue in the field of optical functional materials. The present system is useful for the demonstration of high-temperature photo-switching material.

  19. Reliability of steam generator tubes with axial cracks

    SciTech Connect (OSTI)

    Cizelj, L.; Mavko, B. [Jozef Stefan Inst., Ljubljana (Slovenia). Reactor Engineering Div.; Vencelj, P. [Univ. of Ljubljana (Slovenia). Faculty of Mathematics and Physics

    1996-11-01

    An approach for estimating the failure probability of tubes containing through-wall axial cracks has already been proposed by the authors. It is based on probabilistic fracture mechanics and accounts for scatter in tube geometry and material properties, scatter in residual and operational stresses responsible for crack propagation, and characteristics of nondestructive examination and plugging procedures (e.g., detection probability, sizing accuracy, human errors). Results of preliminary tests demonstrated wide applicability of this approach and triggered some improvements. The additions to the model are extensively discussed in this paper. Capabilities are demonstrated by results of analysis of steam generator no. 1 in Slovenian nuclear power plant located in Krsko after the 1992 inspection and plugging campaign. First, the number of cracked tubes and the crack length distribution were estimated using data obtained by the 100% motorized pancake coil inspection. The inspection and plugging activities were simulated in the second step to estimate the efficiency of maintenance in terms of single and multiple-tube rupture probabilities. They were calculated as a function of maximum allowable crack length. The importance of human errors and some limitations of present nondestructive examination techniques were identified. The traditional wall thickness and crack-length-based plugging criteria are compared. The crack-length-based criterion is shown to be more efficient and more safe, especially because of strong suppression effect on probability of multiple-tube rupture. The results are considered to be important for safety and maintenance of existing plants and for further research.

  20. Fatigue crack growth behavior of Ti-1100 at elevated temperature

    SciTech Connect (OSTI)

    Maxwell, D.C.; Nicholas, T.

    1995-12-31

    Effects of temperature, frequency, and cycles with superimposed hold times are evaluated in Ti-1100 in order to study the complex creep-fatigue-environment interactions in this material. Crack growth rate tests conducted at cyclic loading frequency of 1.0 Hz show that raising the temperature from 593 to 650 C has only a slightly detrimental effect on crack growth rate, although these temperatures produce growth rates significantly higher than at room temperature. From constant {Delta}K tests, the effects of temperature at constant frequency show a minimum crack growth rate at 250 C. From the minimum crack growth rate at 250 C, the crack growth rate increases linearly with temperature. Increases in frequency at constant temperatures of 593 and 650 C produce a continuous decrease in growth rate in going from 0.001 to 1.0 Hz, although the behavior is primarily cycle dependent in this region. Tests at 1.0 Hz with superimposed hold times from 1 to 1,000 s are used to evaluate creep-fatigue-environment interactions. Hold times at maximum load are found to initially decrease and then increase the cyclic crack growth rate with increasing duration. This is attributed to crack-tip blunting during short hold times and environmental degradation at long hold times. Hold times at minimum load show no change in growth rates, indicating that there is no net environmental degradation to the bulk material beyond that experienced during the baseline 1 Hz cycling.

  1. Solar-thermal reaction processing

    DOE Patents [OSTI]

    Weimer, Alan W; Dahl, Jaimee K; Lewandowski, Allan A; Bingham, Carl; Raska Buechler, Karen J; Grothe, Willy

    2014-03-18

    In an embodiment, a method of conducting a high temperature chemical reaction that produces hydrogen or synthesis gas is described. The high temperature chemical reaction is conducted in a reactor having at least two reactor shells, including an inner shell and an outer shell. Heat absorbing particles are included in a gas stream flowing in the inner shell. The reactor is heated at least in part by a source of concentrated sunlight. The inner shell is heated by the concentrated sunlight. The inner shell re-radiates from the inner wall and heats the heat absorbing particles in the gas stream flowing through the inner shell, and heat transfers from the heat absorbing particles to the first gas stream, thereby heating the reactants in the gas stream to a sufficiently high temperature so that the first gas stream undergoes the desired reaction(s), thereby producing hydrogen or synthesis gas in the gas stream.

  2. Research and development of rapid hydrogenation for coal conversion to synthetic motor fuels (riser cracking of coal). Final report, April 1, 1976-September 30, 1980

    SciTech Connect (OSTI)

    Duncan, D. A.; Beeson, J. L.; Oberle, R. D.

    1981-02-01

    The objective of the program described was to develop a noncatalytic process for the hydropyrolysis of lignite and coal to produce high-octane blending gasoline constituents, methane, ethane, and carbon oxides. The process would operate in a balanced plant mode, using spent char to generate process hydrogen by steam-oxygen gasification. The technical program included the construction and operating of a bench-scale unit (5-10 lb/hr), the design, construction, and operation of a process development unit (PDU) (100 lb/hr), and a final technical and economic assessment of the process, called Riser Cracking of Coal. In the bench-scale unit program, 143 runs were made investigating the effects of pressure, temperature, heating rate, residence time, and particle size, processing North Dakota lignite in hydrogen. Some runs were made in which the hydrogen was preheated to pyrolysis temperatures prior to contact with the coal, and, also, in which steam was substituted for half of the hydrogen. Attempts to operate the bench-scale unit at 1200 psig and 1475/sup 0/F were not successful. Depth of carbon conversion was found to be influenced by hydrogen pressure, hydrogen-to-coal ratio, and the severity of the thermal treatment. The composition of hydrocarbon liquids produced was found to change with severity. At low severity, the liquids contained sizable fractions of phenols and cresols. At high severity, the fraction of phenols and cresols was much reduced, with an attendant increase in BTX. In operating the PDU, it was necessary to use more oxygen than was planned to achieve pyrolysis temperatures because of heat losses, and portions of hydrocarbon products were lost through combustion with a large increase in carbon oxide yields. Economic studies, however, showed that selling prices for gasoline blending stock, fuel oil, and fuel gas are competitive in current markets, so that the process is held to warrant further development.

  3. Thermal engine

    SciTech Connect (OSTI)

    Karnes, T.E.; Trupin, R.J.

    1984-01-03

    A thermal engine utilizing a strip of nitinol material or other thermally responsive shape memory effect material to drive a reciprocating output shaft, said strip of material forming a common wall between two different alternating temperature sources which thermally cycle the material.

  4. Stress-corrosion cracking of copper single crystals

    SciTech Connect (OSTI)

    Sieradzki, K.; Newman, R.C.; Sabatini, R.L.

    1984-10-01

    Constant extension rate tests have been carried out in a sodium nitrite solution. Crack velocities up to 30 nm per second were obtained at 30/sup 0/C. If dynamic straining is stopped, the cracks apparently stop growing within about 20 ..mu..m. The steps between adjacent flat facets are more energy-absorbing than in ..cap alpha..-brass, providing a possible explanation for the importance of dynamic strain. Simultaneous acoustic emission and electrochemical current transients suggest that cracking proceeds by discontinuous cleavage.

  5. Tearing of thin sheets: Cracks interacting through an elastic ridge

    E-Print Network [OSTI]

    Fabian Brau

    2014-12-17

    We study the interaction between two cracks propagating quasistatically during the tearing of a thin brittle sheet. We show that the cracks attract each other following a path described by a power law resulting from the competition between elastic and fracture energies. The power law exponent (8/11) is in close agreement with experiments. We also show that a second (asymptotic) regime, with an exponent of 9/8, emerges for small distances between the two crack tips due to the finite transverse curvature of the elastic ridge joining them.

  6. Thermal Flipping of Interstellar Grains

    E-Print Network [OSTI]

    Joseph C. Weingartner

    2008-08-27

    In interstellar dust grains, internal processes dissipate rotational kinetic energy. The dissipation is accompanied by thermal fluctuations, which transfer energy from the vibrational modes to rotation. Together, these processes are known as internal relaxation. For the past several years, internal relaxation has been thought to give rise to thermal flipping, with profound consequences for grain alignment theory. I show that thermal flipping is not possible in the limit that the inertia tensor does not vary with time.

  7. Thermal healing of realistic flaws in glass

    E-Print Network [OSTI]

    Zaccaria, Marco; Overend, Mauro

    2015-01-01

    in glass plates.â?ť Proc. Glass processing days, Tampere, Finland. 447 Anunmana, C., Anusavice, K. J., Mecholsky, J.J., (2009). â??Residual stress in glass: 448 indentation crack and fractography approaches.â?ť Dent.Mater., 40(11), 1453-1458. 449 ASTM...

  8. White(etching!matter!in!bearing!steel! Part1:!Controlled(cracking!of!52100!steel!

    E-Print Network [OSTI]

    Cambridge, University of

    ! quenched! and! untempered! steel! normally! used! in! the! manufacture! of! bearings.!The!varieties!of!cracks!studied!include!sparsely!distributed!martensite(lubricant!interactions,!or!hydrogen!trapping!can!be!studied!further.! ! Keywords:!bearing!steel,!indentation!cracks,!cracked!martensite,!grain(boundary!decohesion,! surface! 1! White(etching!matter!in!bearing!steel! Part1:!Controlled(cracking!of!52100!steel! ! W

  9. Crack coalescence in rock-like material under cycling loading

    E-Print Network [OSTI]

    Ko, Tae Young, 1973-

    2005-01-01

    A total of 170 tests (68 tests for monotonic loading, 102 tests for cyclic loading) have been performed to investigate crack initiation, propagation and coalescence. The specimens have two pre-existing flaws which are ...

  10. HYDROLOGICAL PROCESSES Hydrol. Process. 22, 980986 (2008)

    E-Print Network [OSTI]

    2008-01-01

    in their temperature. The results have consequences for thermally sensitive hydroecological processes and implications, especially when several sources of thermal energy are present, such as groundwater flow (Webb and Zhang, 1999 complexity in thermal regimes of surface water and their implications for ecological processes. A useful

  11. From thermally activated to viscosity controlled fracture of biopolymer hydrogels

    E-Print Network [OSTI]

    T. Baumberger; O. Ronsin

    2008-10-22

    We report on rate-dependent fracture energy measurements over three decades of steady crack velocities in alginate and gelatin hydrogels. We evidence that, irrespective of gel thermo-reversibility, thermally activated "unzipping" of the non-covalent cross-link zones results in slow crack propagation, prevaling against the toughening effect of viscous solvent drag during chain pull-out, which becomes efficient above a few mm.s$^{-1}$. We extend a previous model [Baumberger {\\it et al.} Nature Materials, {\\bf 5}, 552 (2006)] to account for both mechanisms, and estimate the microscopic unzipping rates.

  12. Analytical determination of critical crack size in solar cells

    SciTech Connect (OSTI)

    Chen, C.P.

    1988-05-01

    Although solar cells usually have chips and cracks, no material specifications concerning the allowable crack size on solar cells are available for quality assurance and engineering design usage. Any material specifications that the cell manufacturers use were developed for cosmetic reasons that have no technical basis. Therefore, the Applied Solar Energy Corporation (ASEC) has sponsored a continuing program for the fracture mechanics evaluation of GaAs. Fracture mechanics concepts were utilized to develop an analytical model that can predict the critical crack size of solar cells. This model indicates that the edge cracks of a solar cell are more critical than its surface cracks. In addition, the model suggests that the material specifications on the allowable crack size used for Si solar cells should not be applied to GaAs solar cells. The analytical model was applied to Si and GaAs solar cells, but it would also be applicable to the semiconductor wafers of other materials, such as a GaAs thin film on a Ge substrate, using appropriate input data.

  13. Direct Observation of the Phenomenology of a Solid Thermal Explosion Using Time-Resolved Proton Radiography

    SciTech Connect (OSTI)

    Smilowitz, L.; Henson, B. F.; Romero, J. J.; Asay, B. W.; Schwartz, C. L.; Saunders, A.; Merrill, F. E.; Morris, C. L.; Kwiatkowski, K.; Hogan, G.; Nedrow, P.; Murray, M. M.; Thompson, T. N.; McNeil, W.; Rightley, P.; Marr-Lyon, M.

    2008-06-06

    We present a new phenomenology for burn propagation inside a thermal explosion based on dynamic radiography. Radiographic images were obtained of an aluminum cased solid cylindrical sample of a plastic bonded formulation of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine. The phenomenology observed is ignition followed by cracking in the solid accompanied by the propagation of a radially symmetric front of increasing proton transmission. This is followed by a further increase in transmission through the sample, ending after approximately 100 {mu}s. We show that these processes are consistent with the propagation of a convective burn front followed by consumption of the remaining solid by conductive particle burning.

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

    DOE Patents [OSTI]

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

    2003-02-11

    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.

  15. Development of an Innovative High-Thermal Conductivity UO2 Ceramic Composites Fuel Pellets with Carbon Nano-Tubes Using Spark Plasma Sintering

    SciTech Connect (OSTI)

    Subhash, Ghatu; Wu, Kuang-Hsi; Tulenko, James

    2014-03-10

    Uranium dioxide (UO2) is the most common fuel material in commercial nuclear power reactors. Despite its numerous advantages such as high melting point, good high-temperature stability, good chemical compatibility with cladding and coolant, and resistance to radiation, it suffers from low thermal conductivity that can result in large temperature gradients within the UO2 fuel pellet, causing it to crack and release fission gases. Thermal swelling of the pellets also limits the lifetime of UO2 fuel in the reactor. To mitigate these problems, we propose to develop novel UO2 fuel with uniformly distributed carbon nanotubes (CNTs) that can provide high-conductivity thermal pathways and can eliminate fuel cracking and fission gas release due to high temperatures. CNTs have been investigated extensively for the past decade to explore their unique physical properties and many potential applications. CNTs have high thermal conductivity (6600 W/mK for an individual single- walled CNT and >3000 W/mK for an individual multi-walled CNT) and high temperature stability up to 2800°C in vacuum and about 750°C in air. These properties make them attractive candidates in preparing nano-composites with new functional properties. The objective of the proposed research is to develop high thermal conductivity of UO2–CNT composites without affecting the neutronic property of UO2 significantly. The concept of this goal is to utilize a rapid sintering method (5–15 min) called spark plasma sintering (SPS) in which a mixture of CNTs and UO2 powder are used to make composites with different volume fractions of CNTs. Incorporation of these nanoscale materials plays a fundamentally critical role in controlling the performance and stability of UO2 fuel. We will use a novel in situ growth process to grow CNTs on UO2 particles for rapid sintering and develop UO2-CNT composites. This method is expected to provide a uniform distribution of CNTs at various volume fractions so that a high thermally conductive UO2-CNT composite is obtained with a minimal volume fraction of CNTs. The mixtures are sintered in the SPS facility at a range of temperatures, pressures, and time durations so as to identify the optimal processing conditions to obtain the desired microstructure of sintered UO2-CNT pellets. The second objective of the proposed work is to identify the optimal volume fraction of CNTs in the microstructure of the composites that provides the desired high thermal conductivity yet retaining the mechanical strength required for efficient function as a reactor fuel. We will systematically study the resulting microstructure (grain size, porosity, distribution of CNTs, etc.) obtained at various SPS processing conditions using optical microscopy, scanning electron microscopy (SEM), and transmission electron microscope (TEM). We will conduct indentation hardness measurements and uniaxial strength measurements as a function of volume fraction of CNTs to determine the mechanical strength and compare them to the properties of UO2. The fracture surfaces will be studied to determine the fracture characteristics that may relate to the observed cracking during service. Finally, we will perform thermal conductivity measurements on all the composites up to 1000° C. This study will relate the microstructure, mechanical properties, and thermal properties at various volume fractions of CNTs. The overall intent is to identify optimal processing conditions that will provide a well-consolidated compact with optimal microstructure and thermo-mechanical properties. The deliverables include: (1) fully characterized UO2-CNT composite with optimal CNT volume fraction and high thermal conductivity and (2) processing conditions for production of UO2-CNT composite pellets using SPS method.

  16. Fatigue crack growth behavior of Al-Li alloy 1441

    SciTech Connect (OSTI)

    Prakash, R.V.; Parida, B.K.

    1995-12-31

    Fatigue crack growth behavior of Al-Li alloy 1441 having a marginally lower lithium content, compared to 80xx and 20xx series Al-Li alloys is presented in this paper. This investigation was conducted on single edge tension--SE(T)--specimens, under constant amplitude as well as under MiniLCA flight spectrum loading with the specific objective of determining the effects of stress ratio, orientation, thickness and cladding. Three thicknesses were considered: 1.2 mm(clad and unclad), 2.0 mm(clad and unclad) and 8.0 mm unclad. Constant amplitude fatigue tests were conducted at stress ratios of {minus}0.3, 0.1 and 0.7. Testing was performed under ambient conditions and along three orientations, namely L-T, T-L and L+45 degrees. Crack growth characteristics of this alloy are compared with that of BS:L73 (2014-T4 equivalent) for assessing the possibility of replacing BS:L73. Significant effect of stress ratio on crack growth rate was observed in all thicknesses. However, in case of 1.2 and 2.0 mm thick sheets, the effect was minimal at intermediate-crack growth regime. The orientation of the specimen does not adversely affect the fatigue crack growth behavior of 8.0 mm and 2.0 mm thick specimens. However, for 1.2 mm unclad sheet crack growth resistance in L-T direction was found to be superior to that along T-L direction. In majority of test cases considered, no significant effect was observed on crack growth rate due to thickness or cladding. Crack growth characteristics of Al-Li alloy 1441 and Al-Cu alloy BS:L73 under constant amplitude as well as MiniLCA spectrum loading are similar in the low and intermediate-crack growth rate regime. Based on these observations, it is felt that this Al-Li alloy has the potential for future aerospace applications.

  17. Thermal desorption for passive dosimeter 

    E-Print Network [OSTI]

    Liu, Wen-Chen

    1981-01-01

    recovery of styrene and improved precision when compared with thermal desorption. In addition, thermal desorption tended to breakdown sty- rene, which is vulnerable to heat. The breakdown product may interfere with the analysis results if thermal desorp... of the activation processes. (12, 1&) The first step in the production of activated carbon is carbonization, which is the formation of a char from a source material. The source materials may be coconut shells, peach pits, sawdust, wood char, etc ~ Carbonization...

  18. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    Solar Thermal Collectors .is solar energy. Solar thermal collector arrays can be usedon integrating solar thermal collectors with desalination

  19. Fischer-Tropsch indirect coal liquefaction design/economics-mild hydrocracking vs. fluid catalytic cracking

    SciTech Connect (OSTI)

    Choi, G.N.; Kramer, S.J.; Tam, S.S. [Bechtel Corp., San Francisco, CA (United States); Reagan, W.J. [Amoco Oil Co., Naperville, IL (United States)] [and others

    1996-12-31

    In order to evaluate the economics of Fischer-Tropsch (F-T) indirect coal liquefaction, conceptual plant designs and detailed cost estimates were developed for plants producing environmentally acceptable, high-quality, liquid transportation fuels meeting the Clean Air Act requirements. The designs incorporate the latest developments in coal gasification technology and advanced (F-T) slurry reactor design. In addition, an ASPEN Plus process simulation model was developed to predict plant material and energy balances, utility requirements, operating and capital costs at varying design conditions. This paper compares mild hydrocracking and fluid catalytic cracking as alternative methods for upgrading the F-T wax.

  20. Environmentally assisted cracking in light water reactors annual report January - December 2005.

    SciTech Connect (OSTI)

    Alexandreanu, B.; Chen, Y.; Chopra, O. K.; Chung, H. M.; Gruber, E. E.; Shack, W. J.; Soppet, W. K.

    2007-08-31

    This report summarizes work performed from January to December 2005 by Argonne National Laboratory on fatigue and environmentally assisted cracking in light water reactors (LWRs). Existing statistical models for estimating the fatigue life of carbon and low-alloy steels and austenitic stainless steels (SSs) as a function of material, loading, and environmental conditions were updated. Also, the ASME Code fatigue adjustment factors of 2 on stress and 20 on life were critically reviewed to assess the possible conservatism in the current choice of the margins. An approach, based on an environmental fatigue correction factor, for incorporating the effects of LWR environments into ASME Section III fatigue evaluations is discussed. The susceptibility of austenitic stainless steels and their welds to irradiation-assisted stress corrosion cracking (IASCC) is being evaluated as a function of the fluence level, water chemistry, material chemistry, and fabrication history. For this task, crack growth rate (CGR) tests and slow strain rate tensile (SSRT) tests are being conducted on various austenitic SSs irradiated in the Halden boiling water reactor. The SSRT tests are currently focused on investigating the effects of the grain boundary engineering process on the IASCC of the austenitic SSs. The CGR tests were conducted on Type 316 SSs irradiated to 0.45-3.0 dpa, and on sensitized Type 304 SS and SS weld heat-affected-zone material irradiated to 2.16 dpa. The CGR tests on materials irradiated to 2.16 dpa were followed by a fracture toughness test in a water environment. The effects of material composition, irradiation, and water chemistry on growth rates are discussed. The susceptibility of austenitic SS core internals to IASCC and void swelling is also being evaluated for pressurized water reactors. Both SSRT tests and microstructural examinations are being conducted on specimens irradiated in the BOR-60 reactor in Russia to doses up to 20 dpa. Crack growth rate data, obtained in the pressurized water reactor environment, are presented on Ni-alloy welds prepared in the laboratory or obtained from the nozzle-to-pipe weld of the V. C. Summer reactor. The experimental CGRs under cyclic and constant load are compared with the existing CGR data for Ni-alloy welds to determine the relative susceptibility of these materials to environmentally enhanced cracking under a variety of loading conditions.

  1. Ocean Thermal Energy Conversion Basics | Department of Energy

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

    Ocean Thermal Energy Conversion Basics Ocean Thermal Energy Conversion Basics August 16, 2013 - 4:22pm Addthis A process called ocean thermal energy conversion (OTEC) uses the heat...

  2. The Role of Thermal Energy Storage in Industrial Energy Conservation 

    E-Print Network [OSTI]

    Duscha, R. A.; Masica, W. J.

    1979-01-01

    Thermal Energy Storage for Industrial Applications is a major thrust of the Department of Energy's Thermal Energy Storage Program. Utilizing Thermal Energy Storage (TES) with process or reject heat recovery systems has been shown to be extremely...

  3. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    and thermal energy storage in solar thermal applications,"aided or powered by solar thermal energy. A section is alsoexhaustive review of solar thermal energy systems has been

  4. Advanced Thermal Control

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

    thermal models power density cost lifetime Advanced Thermal Interface Materials Advanced Heat Transfer Technologies Air Cooling Thermal System Performance and Integration Thermal...

  5. 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.

  6. Dynamic crack initiation toughness : experiments and peridynamic modeling.

    SciTech Connect (OSTI)

    Foster, John T.

    2009-10-01

    This is a dissertation on research conducted studying the dynamic crack initiation toughness of a 4340 steel. Researchers have been conducting experimental testing of dynamic crack initiation toughness, K{sub Ic}, for many years, using many experimental techniques with vastly different trends in the results when reporting K{sub Ic} as a function of loading rate. The dissertation describes a novel experimental technique for measuring K{sub Ic} in metals using the Kolsky bar. The method borrows from improvements made in recent years in traditional Kolsky bar testing by using pulse shaping techniques to ensure a constant loading rate applied to the sample before crack initiation. Dynamic crack initiation measurements were reported on a 4340 steel at two different loading rates. The steel was shown to exhibit a rate dependence, with the recorded values of K{sub Ic} being much higher at the higher loading rate. Using the knowledge of this rate dependence as a motivation in attempting to model the fracture events, a viscoplastic constitutive model was implemented into a peridynamic computational mechanics code. Peridynamics is a newly developed theory in solid mechanics that replaces the classical partial differential equations of motion with integral-differential equations which do not require the existence of spatial derivatives in the displacement field. This allows for the straightforward modeling of unguided crack initiation and growth. To date, peridynamic implementations have used severely restricted constitutive models. This research represents the first implementation of a complex material model and its validation. After showing results comparing deformations to experimental Taylor anvil impact for the viscoplastic material model, a novel failure criterion is introduced to model the dynamic crack initiation toughness experiments. The failure model is based on an energy criterion and uses the K{sub Ic} values recorded experimentally as an input. The failure model is then validated against one class of problems showing good agreement with experimental results.

  7. Materials processing issues for non-destructive laser gas sampling (NDLGS)

    SciTech Connect (OSTI)

    Lienert, Thomas J [Los Alamos National Laboratory

    2010-12-09

    The Non-Destructive Laser Gas Sampling (NDLGS) process essentially involves three steps: (1) laser drilling through the top of a crimped tube made of 304L stainles steel (Hammar and Svennson Cr{sub eq}/Ni{sub eq} = 1.55, produced in 1985); (2) gas sampling; and (3) laser re-welding of the crimp. All three steps are performed in a sealed chamber with a fused silica window under controlled vacuum conditions. Quality requirements for successful processing call for a hermetic re-weld with no cracks or other defects in the fusion zone or HAZ. It has been well established that austenitic stainless steels ({gamma}-SS), such as 304L, can suffer from solidification cracking if their Cr{sub eq}/Ni{sub eq} is below a critical value that causes solidification to occur as austenite (fcc structure) and their combined impurity level (%P+%S) is above {approx}0.02%. Conversely, for Cr{sub eq}/Ni{sub eq} values above the critical level, solidification occurs as ferrite (bcc structure), and cracking propensity is greatly reduced at all combined impurity levels. The consensus of results from studies of several researchers starting in the late 1970's indicates that the critical Cr{sub eq}/Ni{sub eq} value is {approx}1.5 for arc welds. However, more recent studies by the author and others show that the critical Cr{sub eq}/Ni{sub eq} value increases to {approx}1 .6 for weld processes with very rapid thermal cycles, such as the pulsed Nd:YAG laser beam welding (LBW) process used here. Initial attempts at NDLGS using pulsed LBW resulted in considerable solidification cracking, consistent with the results of work discussed above. After a brief introduction to the welding metallurgy of {gamma}-SS, this presentation will review the results of a study aimed at developing a production-ready process that eliminates cracking. The solution to the cracking issue, developed at LANL, involved locally augmenting the Cr content by applying either Cr or a Cr-rich stainless steel (ER 312) to the top of the crimp using the electro-spark deposition (ESD) process followed by laser mixing, drilling and rewelding. Results of a study of the ESD parameters on deposition rate and efficiency will be discussed along with mass balance calculations for determining the desired Cr content to eliminate cracking. The study also required purchase of new pulsed Nd:YAG laser welders. Evaluation of the performance of the new lasers, including beam profiling results, will also be presented. Development of a mixing, drilling and re-welding process at atmospheric pressure with inert gas shielding demonstrated the efficacy of the Cr-augmentation approach. However, extending the process to vacuum conditions proved more challenging owing to loss of laser transmission through the window from spatter and condensation of metal vapors. Solutions developed to circumvent hese issues will be reviewed. Weld microstructures found with various Cr levels will be presented and discussed.

  8. Fluid Catalytic Cracking Power Recovery Computer Simulation 

    E-Print Network [OSTI]

    Samurin, N. A.

    1979-01-01

    operating conditions. The digital computer model simulates the performance of the axial compressor, power recovery expander, regenerator section, and system pressure drops. The program can simulate the process system design conditions for compatibility...

  9. Failure probability of axially cracked steam generator tubes; A probabilistic fracture mechanics model

    SciTech Connect (OSTI)

    Mavko, B.; Cizelj, L. (Jozef Stefan Inst., Reactor Engineering Div., P.O. Box 100, 61111 Ljubljana, Slovenia (YU))

    1992-05-01

    In this paper a model for estimating the failure probability of axially cracked steam generator tubes is proposed. The model compares observed crack length distribution with critical crack length distribution by means of probabilistic fracture mechanics. The observed crack length is influenced by measured data, measurement reliability, sizing accuracy, and predicted crack growth rate. The critical crack length is defined by a deterministic mechanical model. All cracks are conservatively assumed to extend through the tube wall. The effect of the plugging limit is studied along with the number of cracked tubes to perform risk-based lifetime optimization of steam generators. A numerical example presented considers hypothetical accidental operating conditions during a feedwater line break.

  10. The application of a logic framework for fatigue crack growth analyses to microstructural effects

    SciTech Connect (OSTI)

    Xu, J.G.; Liu, H.W.

    1995-12-31

    {Delta}K has been widely used to correlate da/dN data. The relation between da/dN and {Delta}K is usually found empirically. However, fatigue crack growth relations can also be derived theoretically. Three fatigue crack growth theories are derived for the state of small scale yielding and plane strain. These three theories constitute a logic framework useful for fatigue crack growth analyses. The application of the logic framework to the analyses of microstructural effects on fatigue crack growth is illustrated. The fatigue crack growth curve of 7075-T651 aluminum alloy has five distinct regions. A fatigue crack grows by crack-tip shear decohesion forming striations and by brittle fractures of particles followed by localized shear decohesion at these microcracks forming dimples. The logic framework helps to relate the fatigue crack growth behaviors in these five regions to the fractures of inclusions and to the resistance of grain boundaries and dispersoids to shear decohesion.

  11. Monitoring Cracking of a Smectitic Vertisol using Three-dimensional Electrical Resistivity Tomography 

    E-Print Network [OSTI]

    Ackerson, Jason Paul

    2013-11-20

    Upon desiccation, the matrix of Vertisols and other expansive soils shrinks. Matrix shrinkage results in the formation of cracks that can alter the hydrology of the soil. Despite the importance of cracks, many hydrologic models do not account...

  12. Numerical simulation of oxidation and its effect on the crack growth resistance of titanium alloys 

    E-Print Network [OSTI]

    Triharjanto, Robertus Heru

    1997-01-01

    though the oxidation generally degrades the MMC, the oxidation from the crack surfaces may improve the crack growth resistance of the metal matrix. Titanium alloys are potential candidates for use in MMC. Therefore, a more thorough understanding...

  13. Microwave Enhanced Direct Cracking of Hydrocarbon Feedstock for Energy Efficient Production of Ethylene and Propylene.

    SciTech Connect (OSTI)

    Shulman, Holly; Fall, Morgana; Wagner, Eric; Bowlin, Ricardo

    2012-02-13

    This project demonstrated microwave cracking of ethane with good product conversion and ethylene selectivity, with a short residence time ({approx}0.001 sec). The laboratory scale equipment was designed and built, along with concept designs for larger scale implementation. The system was operated below atmospheric pressures, in the range of 15-55 torr, with argon as a carrier gas. The measured products included hydrogen, methane, acetylene, and ethylene. The results followed similar trends to those predicted by the modeling software SPYRO{reg_sign}, with the exception that the microwave appeared to produce slightly lower amounts of ethylene and methane, although enhanced analytical analysis should reduce the difference. Continued testing will be required to verify these results and quantify the energy consumption of microwave vs. conventional. The microwave cracking process is an attractive option due to the possibility of selectively heating the reaction volume rather than the reactor walls, which may allow novel reactor designs that result in more efficient production of ethylene. Supplemental studies are needed to continue the laboratory testing and refine processing parameters.

  14. Irradiation assisted stress corrosion cracking of HTH Alloy X-750 and Alloy 625

    SciTech Connect (OSTI)

    Mills, W.J.; Lebo, M.R.; Bajaj, R.; Kearns, J.J.; Hoffman, R.C.; Korinko, J.J.

    1994-06-01

    In-reactor testing of bolt-loaded precracked compact tension specimens was performed in 360{degree}C water to determine effect of irradiation on the SCC behavior of HTH Alloy X-750 and direct aged Alloy 625. Out-of-flux and autoclave control specimens provided baseline data. Primary test variables were stress intensity factor, fluence, chemistry, processing history, prestrain. Results for the first series of experiments were presented at a previous conference. Data from two more recent experiments are compared with previous results; they confirm that high irradiation levels significantly reduce SCC resistance in HTH Alloy X-750. Heat-to-heat differences in IASCC were related to differences in boron content, with low boron heats showing improved SCC resistance. The in-reactor SCC performance of Alloy 625 was superior to that for Alloy X-750, as no cracking was observed in any Alloy 625 specimens even though they were tested at very high K{sub 1} and fluence levels. A preliminary SCC usage model developed for Alloy X-750 indicates that in-reactor creep processes, which relax stresses but also increase crack tip strain rates, and radiolysis effects accelerate SCC. Hence, in-reactor SCC damage under high flux conditions may be more severe than that associated with postirradiation tests. In addition, preliminary mechanism studies were performed to determine the cause of IASCC In Alloy X-750.

  15. Agglutination of single catalyst particles during fluid catalytic cracking as observed by X-ray nanotomography

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

    Meirer, F.; Kalirai, S.; Weker, J. Nelson; Liu, Y.; Andrews, J. C.; Weckhuysen, B. M.

    2015-04-14

    Metal accumulation at the catalyst particle surface plays a role in particle agglutination during fluid catalytic cracking.

  16. Incipient Crack Detection in Composite Wind Turbine Blades

    SciTech Connect (OSTI)

    Taylor, Stuart G. [Los Alamos National Laboratory; Choi, Mijin [Chonbuk National University, Korea; Jeong, Hyomi [Chonbuk National University, Korea; Jang, Jae Kyeong [Chonbuk National University, Korea; Park, Gyuhae [Chonnam National University, Korea; Farinholt, Kevin [Commonwealth Center for Advanced Manufacturing, VA; Farrar, Charles R. [Los Alamos National Laboratory; Ammerman, Curtt N. [Los Alamos National Laboratory; Todd, Michael D. [Los Alamos National Laboratory; Lee, Jung-Ryul [Chonbuk National University, Korea

    2012-08-28

    This paper presents some analysis results for incipient crack detection in a 9-meter CX-100 wind turbine blade that underwent fatigue loading to failure. The blade was manufactured to standard specifications, and it underwent harmonic excitation at its first resonance using a hydraulically-actuated excitation system until reaching catastrophic failure. This work investigates the ability of an ultrasonic guided wave approach to detect incipient damage prior to the surfacing of a visible, catastrophic crack. The blade was instrumented with piezoelectric transducers, which were used in an active, pitchcatch mode with guided waves over a range of excitation frequencies. The performance results in detecting incipient crack formation in the fiberglass skin of the blade is assessed over the range of frequencies in order to determine the point at which the incipient crack became detectable. Higher excitation frequencies provide consistent results for paths along the rotor blade's carbon fiber spar cap, but performance falls off with increasing excitation frequencies for paths off of the spar cap. Lower excitation frequencies provide more consistent performance across all sensor paths.

  17. CONTAINED PLASTIC DEFORMATION NEAR CRACKS AND NOTCHES UNDER LONGITUDINAL SHEAR

    E-Print Network [OSTI]

    CONTAINED PLASTIC DEFORMATION NEAR CRACKS AND NOTCHES UNDER LONGITUDINAL SHEAR James R. Rice* ABSTRACT An exact linear elastic-perfectly plastic solution is presented for the problem of a sharp notch coordinates corresponding to given stresses, position of the elastic-plastic boundary, and accompanying

  18. Thin film with oriented cracks on a flexible substrate

    DOE Patents [OSTI]

    Feng, Bao; McGilvray, Andrew; Shi, Bo

    2010-07-27

    A thermoelectric film is disclosed. The thermoelectric film includes a substrate that is substantially electrically non-conductive and flexible and a thermoelectric material that is deposited on at least one surface of the substrate. The thermoelectric film also includes multiple cracks oriented in a predetermined direction.

  19. Solvent control of crack dynamics in a reversible hydrogel

    E-Print Network [OSTI]

    Tristan Baumberger; Christiane Caroli; David Martina

    2006-05-16

    The resistance to fracture of reversible biopolymer hydrogels is an important control factor of the cutting/slicing and eating characteristics of food gels. It is also critical for their utilization in tissue engineering, for which mechanical protection of encapsulated components is needed. Its dependence on loading rate and, recently, on the density and strength of cross-links has been investigated. But no attention was paid so far to solvent nor to environment effects. Here we report a systematic study of crack dynamics in gels of gelatin in water/glycerol mixtures. We show on this model system that: (i) increasing solvent viscosity slows down cracks; (ii) soaking with solvent increases markedly gel fragility; (iii) tuning the viscosity of the (miscible) environmental liquid affects crack propagation via diffusive invasion of the crack tip vicinity. The results point toward the fact that fracture occurs by viscoplastic chain pull-out. This mechanism, as well as the related phenomenology, should be common to all reversibly cross-linked (physical) gels.

  20. Method of making crack-free zirconium hydride

    DOE Patents [OSTI]

    Sullivan, Richard W. (Denver, CO)

    1980-01-01

    Crack-free hydrides of zirconium and zirconium-uranium alloys are produced by alloying the zirconium or zirconium-uranium alloy with beryllium, or nickel, or beryllium and scandium, or nickel and scandium, or beryllium and nickel, or beryllium, nickel and scandium and thereafter hydriding.

  1. PENNY--SHAPED CRACK BRIDGED BY N.V. Movchan,

    E-Print Network [OSTI]

    Bath, University of

    PENNY--SHAPED CRACK BRIDGED BY FIBRES N.V. Movchan, School of Mathematical Sciences, University and Theoretical Physics, Silver Street, Cambridge, CB3 9EW, U.K. Abstract An axi--symmetric problem for a penny traction distribution. In the present paper we deal only with the second step, namely we consider a penny

  2. 1. INTRODUCTION Current design methods focus on crack growth curves which are material properties for given

    E-Print Network [OSTI]

    Hively, Lee M.

    propagation. This technique has been demonstrated by test and analysis in fiberglass composite, aircraft fatigue, as well as Mode I low-temperature creep and stress corrosion. During the 1930s, A. A. Griffith sustained loading of cracks) and stress corrosion cracking (KI scc, JI scc, sustained loading of cracks

  3. Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D

    E-Print Network [OSTI]

    Zhou, Wei

    Hot cracking in tungsten inert gas welding of magnesium alloy AZ91D W. Zhou*, T. Z. Long and C. K of the plates were produced using tungsten inert gas (TIG) welding method. The TIG arc was also used to deposit welding beads on some of the thin plates. No cracking was found in the butt joints. However, hot cracking

  4. Brittle film-induced cracking of ductile substrates , Lijie Qiao a,

    E-Print Network [OSTI]

    Volinsky, Alex A.

    Brittle film-induced cracking of ductile substrates Tao Guo a , Lijie Qiao a, , Xiaolu Pang b 29 May 2015 Revised 22 July 2015 Accepted 23 July 2015 Keywords: Brittle film Ductile substrate Film-induced cracking Dislocations Crack velocity a b s t r a c t Film and substrate mechanical integrity is essential

  5. Mechanics and mechanisms of fatigue damage and crack growth in advanced materials

    E-Print Network [OSTI]

    Ritchie, Robert

    Mechanics and mechanisms of fatigue damage and crack growth in advanced materials R.O. Ritchie*, C 94720-1760, USA Abstract The mechanisms of fatigue-crack propagation in ceramics and intermetallics growth is considered to be a mutual competition between intrinsic mechanisms of crack advance ahead

  6. Permeability and elastic properties of cracked glass under pressure A. OugierSimonin,1

    E-Print Network [OSTI]

    Fortin, Jérôme

    for independent controls of the confining pressure, the axial stress, and pore pressure. We produced cracks with identified average aspect ratio and crack aperture, (2) a very small permeability which decreases as a power behavior of a cracked elastic brittle solid is reversible and independent of the fluid nature. Two

  7. A cracked beam finite element for rotating shaft dynamics and stability analysis

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    A cracked beam finite element for rotating shaft dynamics and stability analysis Saber El Arem Palaiseau, France Abstract In this paper, a method for the construction of a cracked beam finite element is presented. The additional flexibility due to the cracks is identified from three- dimensional finite element

  8. Automated Detection of Cracked Railway Axle Journals Using an Ultrasonic Phased Array Technique 

    E-Print Network [OSTI]

    Baik, Jaeyong

    2014-06-27

    ) automated detection system of a cracked axle journal using the ultrasonic phased array technique, 2) detection of a cracked axle journal using a chain scanner, and 3) cracked axle journal detection using surface waves. An ultrasonic phased array system has a...

  9. Fatigue-Crack Growth Behavior in the Superelastic and Shape-Memory Alloy Nitinol

    E-Print Network [OSTI]

    Ritchie, Robert

    Fatigue-Crack Growth Behavior in the Superelastic and Shape-Memory Alloy Nitinol A.L. McKELVEY and R.O. RITCHIE This article presents a study of fatigue-crack propagation behavior in Nitinol, a 50Ni, and constitutive behavior on crack-growth rates in NiTi.* NITINOL is a thermoelastic alloy with a composition

  10. A penny-shaped cohesive crack model for material damage G. Wang, S.F. Li *

    E-Print Network [OSTI]

    Li, Shaofan

    A penny-shaped cohesive crack model for material damage G. Wang, S.F. Li * Department of Civil solids with ran- domly distributed penny-shaped cohesive micro-cracks (Barenblatt­Dugdale type). Energy are derived based on homogenization of randomly distributed penny-shaped cohesive cracks (Barenblatt

  11. Crack Response to Blast Vibrations and Moisture Induced Volumetric Changes in Foundation Soils

    E-Print Network [OSTI]

    Crack Response to Blast Vibrations and Moisture Induced Volumetric Changes in Foundation Soils By C, Evanston, IL. Abstract In this paper vibratory crack response is compared to that produced by volumetric over a period of weeks to several months. On the other hand, crack response produced by volumetric

  12. the thermal-8 to-plasma

    E-Print Network [OSTI]

    Vertes, Akos

    Modeling the thermal- 8 to-plasma . transitions for Cu photoablation by A. Vertes R. W. Dreyfus D. E. Platt Excimer laser ablation of metals starts as a thermal process in the -1-J/cm2 fluence range on the thermal (diffusivity and vapor pressure) properties of copper, along with electron heating by inverse

  13. Local formation of HArF in solid argon: Low-temperature limit and thermal activation

    E-Print Network [OSTI]

    Lignell, H.; Khriachtchev, L.; Lignell, A.; Räsänen, M.

    2010-01-01

    Räsänen, IR light. The thermal activation of the process wasand R. ?ArHAr? and thermal activation of these processes aretemperature limit and thermal activation H. Lignell, a? L.

  14. Predicting Fracture Energies and Crack-Tip Fields of Soft Tough Materials

    E-Print Network [OSTI]

    Teng Zhang; Shaoting Lin; Hyunwoo Yuk; Xuanhe Zhao

    2015-06-13

    Soft materials including elastomers and gels are pervasive in biological systems and technological applications. Whereas it is known that intrinsic fracture energies of soft materials are relatively low, how the intrinsic fracture energy cooperates with mechanical dissipation in process zone to give high fracture toughness of soft materials is not well understood. In addition, it is still challenging to predict fracture energies and crack-tip strain fields of soft tough materials. Here, we report a scaling theory that accounts for synergistic effects of intrinsic fracture energies and dissipation on the toughening of soft materials. We then develop a coupled cohesive-zone and Mullins-effect model capable of quantitatively predicting fracture energies of soft tough materials and strain fields around crack tips in soft materials under large deformation. The theory and model are quantitatively validated by experiments on fracture of soft tough materials under large deformations. We further provide a general toughening diagram that can guide the design of new soft tough materials.

  15. AQUIFER THERMAL ENERGY STORAGE

    E-Print Network [OSTI]

    Tsang, C.-F.

    2011-01-01

    varying solar energy inputs and thermal or power demands. Itusing aquifers for thermal energy storage. Problems outlinedmatical Modeling of Thermal Energy Storage in Aquifers,"

  16. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    of solar collectors and thermal energy storage in solaraided or powered by solar thermal energy. A section is alsobesides MVC require thermal energy as their primary energy

  17. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    15] O. A. Hamed, "THERMAL PERFORMANCE OF MULTISTAGE FLASHdesa4.aspx. [18] Encon, "Thermal Evaporators," June 2013. [http://www.evaporator.com/thermal-evaporator. [19] Y. Tian

  18. AQUIFER THERMAL ENERGY STORAGE

    E-Print Network [OSTI]

    Tsang, C.-F.

    2011-01-01

    of such an aquifer thermal storage system were studied andusing aquifers for thermal energy storage. Problems outlinedmatical Modeling of Thermal Energy Storage in Aquifers,"

  19. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    This requires no thermal storage tanks, but can have athe need for large thermal storage equipment, the evaporatorinclude analysis of thermal storage. A way of keeping the

  20. AQUIFER THERMAL ENERGY STORAGE

    E-Print Network [OSTI]

    Tsang, C.-F.

    2011-01-01

    aquifers for thermal energy storage. Problems outlined aboveModeling of Thermal Energy Storage in Aquifers," Proceed-ings of Aquifer Thermal Energy Storage Workshop, Lawrence

  1. Thermal Decoupling of Molecular-Relaxation Processes from the Vibrational Density of States at Terahertz Frequencies in Supercooled Hydrogen-Bonded Liquids

    E-Print Network [OSTI]

    Sibik, Juraj; Elliott, Stephen R.; Zeitler, J. Axel

    2014-05-20

    At terahertz frequencies, the libration-vibration motions couple to the dielectric relaxations in disordered hydrogen-bonded solids. The interplay between these processes is still poorly understood, in particular at temperatures below the glass...

  2. Fatigue and Creep Crack Propagation behaviour of Alloy 617 in the Annealed and Aged Conditions

    SciTech Connect (OSTI)

    Julian K. Benz; Richard N. Wright

    2013-10-01

    The crack propagation behaviour of Alloy 617 was studied under various conditions. Elevated temperature fatigue and creep-fatigue crack growth experiments were conducted at 650 and 800 degrees C under constant stress intensity (triangle K) conditions and triangular or trapezoidal waveforms at various frequencies on as-received, aged, and carburized material. Environmental conditions included both laboratory air and characteristic VHTR impure helium. As-received Alloy 617 displayed an increase in the crack growth rate (da/dN) as the frequency was decreased in air which indicated a time-dependent contribution component in fatigue crack propagation. Material aged at 650°C did not display any influence on the fatigue crack growth rates nor the increasing trend of crack growth rate with decreasing frequency even though significant microstructural evolution, including y’ (Ni3Al) after short times, occurred during aging. In contrast, carburized Alloy 617 showed an increase in crack growth rates at all frequencies tested compared to the material in the standard annealed condition. Crack growth studies under quasi-constant K (i.e. creep) conditions were also completed at 650 degrees C and a stress intensity of K = 40 MPa9 (square root)m. The results indicate that crack growth is primarily intergranular and increased creep crack growth rates exist in the impure helium environment when compared to the results in laboratory air. Furthermore, the propagation rates (da/dt) continually increased for the duration of the creep crack growth either due to material aging or evolution of a crack tip creep zone. Finally, fatigue crack propagation tests at 800 degrees C on annealed Alloy 617 indicated that crack propagation rates were higher in air than impure helium at the largest frequencies and lowest stress intensities. The rates in helium, however, eventually surpass the rates in air as the frequency is reduced and the stress intensity is decreased which was not observed at 650 degrees C.

  3. Composition of Municipal Solid Waste-Need for Thermal Treatment in the present Indian context

    E-Print Network [OSTI]

    Columbia University

    , Biomethanation, pelletization with or without energy recovery and other thermal processes for adoption

  4. Compliant alkali silicate sealing glass for solid oxide fuel cell applications: thermal cycle stability and chemical compatibility

    SciTech Connect (OSTI)

    Chou, Y. S.; Thomsen, Edwin C.; Williams, Riley T.; Choi, Jung-Pyung; Canfield, Nathan L.; Bonnett, Jeff F.; Stevenson, Jeffry W.; Shyam, Amit; Lara-Curzio, E.

    2011-03-01

    An alkali silicate glass (SCN-1) is currently being evaluated as a candidate sealing glass for solid oxide fuel (SOFC) applications. The glass containing ~17 mole% alkalis (K2O and Na2O) remains vitreous and compliant during SOFC operation, unlike conventional SOFC sealing glasses, which experience substantial devitrification after the sealing process. The non-crystallizing compliant sealing glass has lower glass transition and softening temperatures since the microstructure remains glassy without significant crystallite formation, and hence can relieve or reduce residual stresses and also has the potential for crack healing. Sealing approaches based on compliant glass will also need to satisfy all the mechanical, thermal, chemical, physical, and electrical requirements for SOFC applications, not only in bulk properties but also at sealing interfaces. In this first of a series of papers we will report the thermal cycle stability of the glass when sealed between two SOFC components, i.e., a NiO/YSZ anode supported YSZ bilayer and a coated ferritic stainless steel interconnect material. High temperature leak rates were monitored versus thermal cycles between 700-850oC using back pressures ranging from 0.2 psi to 1.0 psi. Isothermal stability was also evaluated in a dual environment consisting of flowing dilute H2 fuel versus ambient air. In addition, chemical compatibility at the alumina and YSZ interfaces was examined with scanning electron microscopy and energy dispersive spectroscopy. The results shed new light on the topic of SOFC glass seal development.

  5. Penny-shaped and half-plane cracks in a transversely isotropic piezoelectric solid under arbitrary loading

    E-Print Network [OSTI]

    Sevostianov, Igor

    Penny-shaped and half-plane cracks in a transversely isotropic piezoelectric solid under arbitrary loading E. Karapetian, I. Sevostianov, M. Kachanov Summary The problem of a penny-shaped crack for a piezoelectric medium with a crack. Solutions for penny-shaped and half-plane cracks in an in®nite medium loaded

  6. Methodology for predicting asphalt concrete overlay life against reflection cracking 

    E-Print Network [OSTI]

    Jayawickrama, Priyantha Warnasuriya

    1985-01-01

    METHODOLOGY FOR PREDICTING ASPHALT CONCRETE OVERLAY Lr 8 AGAINST REFLECTION CRACKING A Thesis by PRIYANTHA NARNASURIYA JAYAWICKRAMA Submitted to the Graduate College of Texas A8M University in Partial fulfillment of the requirements.... Experimental investigations carried out at Ohio State University ( 1, 2, 3) and Texas A8M University ( 4, 5, 6 ) have verified the applicability of fracture mechanics principles in predicting fatigue life of asphalt TIP OF THE CRACX /~ // N/i OVERLAY OLD...

  7. Catalytic cracking receives heavy attention at Q and A meeting

    SciTech Connect (OSTI)

    Not Available

    1993-04-19

    Refiners discussed fluid catalytic cracking (FCC) - the workhorse of the modern refinery - in great detail at the most recent National Petroleum Refiners Association's annual question and answer session on refining and petrochemical technology. Among the topics covered were the newest FCC refractory lining and particulate-control methods. The panel of experts also answered questions on the role of FCC in reducing gasoline benzene to meet reformulated gasoline specifications. This paper discusses refractories; particulate control; gasoline feeds; and benzene reduction.

  8. Crack growth monitoring in harsh environments by electrical potential measurements

    SciTech Connect (OSTI)

    W. R. Lloyd; W. G. Reuter; D. M. Weinberg

    1999-09-19

    Electric potential measurement (EPM) technology offers an attractive alternative to conventional nondestructive evaluation (NDE) for monitoring crack growth in harsh environments. Where conventional NDE methods typically require localized human interaction, the EPM technique developed at the Idaho National Engineering and Environmental Laboratory (INEEL) can be operated remotely and automatically. Once a crack-like defect is discovered via conventional means, EPM can be applied to monitor local crack size changes. This is of particular interest in situations where an identified structural defect is not immediately rejectable from a fitness-for-service viewpoint, but due to operational and environmental conditions may grow to an unsafe size with continuing operation. If the location is in a harsh environment where periodic monitoring by normal means is either too costly or not possible, a very expensive repair may be immediately mandated. However, the proposed EPM methodology may offer a unique monitoring capability that would allow for continuing service. INEEL has developed this methodology, supporting equipment, and calibration information to apply EPM in a field environment for just this purpose. Laboratory and pilot scale tests on full-size engineering structures (pressure vessels and piping) have been successfully performed. The technique is applicable to many severe environments because the sensitive equipment (electronics, operators) can be situated in a remote location, with only current and voltage probe electrical leads entering into the harsh environment. Experimental results showing the utility of the methodology are presented, and unique application concepts that have been examined by multiple experiments are discussed.

  9. Crack Growth Monitoring in Harsh Environments by Electric Potential Measurements

    SciTech Connect (OSTI)

    Lloyd, Wilson Randolph; Reuter, Walter Graham; Weinberg, David Michael

    1999-09-01

    Electric potential measurement (EPM) technology offers an attractive alternative to conventional nondestructive evaluation (NDE) for monitoring crack growth in harsh environments. Where conventional NDE methods typically require localized human interaction, the EPM technique developed at the Idaho National Engineering and Environmental Laboratory (INEEL) can be operated remotely and automatically. Once a crack-like defect is discovered via conventional means, EPM can be applied to monitor local crack size changes. This is of particular interest in situations where an identified structural defect is not immediately rejectable from a fitness-for-service viewpoint, but due to operational and environmental conditions may grow to an unsafe size with continuing operation. If the location is in a harsh environment where periodic monitoring by normal means is either too costly or not possible, a very expensive repair may be immediately mandated. However, the proposed EPM methodology may offer a unique monitoring capability that would allow for continuing service. INEEL has developed this methodology, supporting equipment, and calibration information to apply EPM in a field environment for just this purpose. Laboratory and pilot scale tests on full-size engineering structures (pressure vessels and piping) have been successfully performed. The technique applicable is many severe environments because the sensitive equipment (electronics, operators) can be situated in a remote location, with only current and voltage probe electrical leads entering into the harsh environment. Experimental results showing the utility of the methodology are presented, and unique application concepts that have been examined by multiple experiments are discussed.

  10. Advances in crack-arrest technology for reactor pressure vessels

    SciTech Connect (OSTI)

    Bass, B.R.; Pugh, C.E.

    1988-01-01

    The Heavy-Section Steel Technology (HSST) Program at the Oak Ridge National Laboratory (ORNL) under the sponsorship of the US Nuclear Regulatory Commission is continuing to improve the understanding of conditions that govern the initiation, rapid propagation, arrest, and ductile tearing of cracks in reactor pressure vessel (RPV) steels. This paper describes recent advances in a coordinated effort being conducted under the HSST Program by ORNL and several subcontracting groups to develop the crack-arrest data base and the analytical tools required to construct inelastic dynamic fracture models for RPV steels. Large-scale tests are being carried out to generate crack-arrest toughness data at temperatures approaching and above the onset of Charpy upper-shelf behavior. Small- and intermediate-size specimens subjected to static and dynamic loading are being developed and tested to provide additional fracture data for RPV steels. Viscoplastic effects are being included in dynamic fracture models and computer programs and their utility validated through analyses of data from carefully controlled experiments. Recent studies are described that examine convergence problems associated with energy-based fracture parameters in viscoplastic-dynamic fracture applications. Alternative techniques that have potential for achieving convergent solutions for fracture parameters in the context of viscoplastic-dynamic models are discussed. 46 refs., 15 figs., 3 tabs.

  11. To Crack or Not to Crack: Strain in High TemperatureSuperconductors

    SciTech Connect (OSTI)

    Godeke, Arno

    2007-08-22

    Round wire Bi 2212 is emerging as a viable successor ofNb3Sn in High Energy Physics and Nuclear Magnetic Resonance, to generatemagnetic fields that surpass the intrinsic limitations of Nb3Sn. Ratherbold claims are made on achievable magnetic fields in applications usingBi 2212, due to the materials' estimated critical magnetic field of 100 Tor higher. High transport currents in high magnetic fields, however, leadto large stress on, and resulting large strain in the superconductor. Theeffect of strain on the critical properties of Bi-2212 is far fromunderstood, and strain is, as with Nb3Sn, often treated as a secondaryparameter in the design of superconducting magnets. Reversibility of thestrain induced change of the critical surface of Nb3Sn, points to anelectronic origin of the observed strain dependence. Record breaking highfield magnets are enabled by virtue of such reversible behavior. Straineffects on the critical surface of Bi-2212, in contrast, are mainlyirreversible and suggest a non-electronic origin of the observed straindependence, which appears to be dominated by the formation of cracks inthe superconductor volumes. A review is presented of available results onthe effects of strain on the critical surface of Bi-2212, Bi-2223 andYBCO. It is shown how a generic behavior emerges for the (axial) straindependence of the critical current density, and how the irreversiblereduction of the critical current density is dominated by strain inducedcrack formation in the superconductor. From this generic model it becomesclear that magnets using high temperature superconductors will be strainlimited far before the intrinsic magnetic field limitations will beapproached, or possibly even before the magnetic field limitation ofNb3Sn can be surpassed. On a positive note, in a very promising recentresult from NIST on the axial strain dependence of the critical currentdensity in extremely well aligned YBCO, reversible behavior was observed.This result emphasizes the need for further conductor development,specifically for round wire Bi-2212, to generate a wire with a similarreversible dependence on strain. Availability of such a wire will enablethe construction of magnets that can indeed generate fields that farsurpass the limitations of Nb3Sn superconductors.

  12. Thermal dissolution of solid fossil fuels

    SciTech Connect (OSTI)

    E.G. Gorlov

    2007-10-15

    The use of oil shales and coals in the processes of thermal dissolution is considered. It is shown that thermal dissolution is a mode of liquefaction of solid fossil fuels and can be used both independently and in combination with liquefaction of coals and processing of heavy petroleum residues.

  13. Evolution of Crack-Tip Transformation Zones in Superelastic Nitinol Subjected to in Situ Fatigue. a Fracture Mechanics And Synchrotron X-Ray Microdiffraction Analysis

    SciTech Connect (OSTI)

    Robertson, S.W.; Mehta, A.; Pelton, A.R.; Ritchie, R.O.; /UC, Berkeley /SLAC, SSRL

    2009-04-29

    The ultrahigh spatial resolution ({approx}1 {micro}m{sup 2}) of synchrotron X-ray microdiffraction is combined with fracture mechanics techniques to directly measure in situ three-dimensional strains, phases and crystallographic alignment ahead of a growing fatigue crack (100 cycles in situ) in superelastic Nitinol. The results provide some surprising insights into the growth of cracks in phase-transforming material at the microscale. Specifically, despite a macroscopic superelastic strain recovery of 6-8% associated with the phase transformation, individual austenite grains experience local strains of less than 1.5%. This observation indicates that it is the localized process of the accommodation of the transformation and subsequent loading of the martensite that provide the main source of the large recoverable strains. Furthermore, the plastic region ahead of the crack is composed of deformed martensite. This micromechanical transformation process is dependent upon the material texture, and directly influences the transformation zone size/shape as well as the crack path.

  14. Asphalt overlay design methods for rigid pavements considering rutting, reflection cracking, and fatigue cracking. Research report September 1996--August 1997

    SciTech Connect (OSTI)

    Cho, Y.H.; Liu, C.; Dossey, T.; McCullough, B.F.

    1998-10-01

    An asphalt concrete pavement (ACP) overlay over a rigid pavement represents a viable rehabilitation strategy. It can provide good serviceability at an initial construction cost that is substantially less than that of a rigid overlay rehabilitation. In addition, ACP overlays require less construction time, which can reduce user costs during construction. However, it may not be the most economical solution for long-term rehabilitation. Because of their relatively short service life, ACP overlays may require maintenance sooner than rigid overlays. And one of the more critical distresses that effectively determine the life span of the structure is reflection cracking. This report investigates alternative strategies that seek to prevent reflection cracking on ACP overlays.

  15. Thermal Transport in Nanoporous Materials for Energy Applications

    E-Print Network [OSTI]

    Fang, Jin

    2012-01-01

    Thermal Conductivity Measurement . . . . . . . . . . . . .Thermal ConductivityThermal Conductivity . . . . . . . . . . . . . . . .Thermal

  16. Enhancing Low-Grade Thermal Energy Recovery in a Thermally Regenerative Ammonia Battery Using

    E-Print Network [OSTI]

    Enhancing Low-Grade Thermal Energy Recovery in a Thermally Regenerative Ammonia Battery Using of renewable energy that is carbon neutral and sustainable.[1] Low-grade thermal energy from either industrial processes or natural solar or geothermal pro- cesses becomes attractive as a possible energy source because

  17. 400 Final Version of PIERS Abstracts will be available on www.piers.org Efficiency Optimization for Microwave Thermal Processing of

    E-Print Network [OSTI]

    Yakovlev, Vadim

    optimization of the systems of microwave heating of materials whose media parameters (the dielectric constant and a cylindrical sample of processed material on it. The optimization problem is formulated as follows: Given: (1400 Final Version of PIERS Abstracts will be available on www.piers.org Efficiency Optimization

  18. Microstructure, Processing, Performance Relationships for High Temperature Coatings

    SciTech Connect (OSTI)

    Thomas Lillo; Richard Wright

    2009-05-01

    HVOF coatings have shown high resistance to corrosion in fossil energy applications and it is generally accepted that mechanical failure, e.g. cracking or spalling, ultimately will determine coating lifetime. The high velocity oxygen-fuel method (HVOF) for applying coatings is one of the most commercially viable and allows the control of various parameters including powder particle velocity and temperature which influence coating properties, such as residual stress, bond coat strength and microstructure. The mechanical durability of coatings is being assessed using a dual eddy current coil method to monitor crack formation in real time during thermal cycling. Absolute impedence signals from two coils, which interrogate two different areas on the sample, are collected. Crack detection can be determined from the differential signal generated from these absolute signals. The coils are operated at two different frequencies, resulting in two differential signals used for crack detection. Currently this crack detection method is being used to elucidate the influence of thermal cycling temperature and coating thickness on cracking. Recent results (cycles to failure) will be presented for FeAl coatings thermally sprayed (HVOF) onto carbon steel to two coating thicknesses (160 microns and 250 microns thick) and subsequently cycled at temperatures up to 700oC. Thinner coatings exhibit greater resistance to cracking. Ultimately the resistance to cracking will be used to explore the relationship between HVOF spraying parameters, the mechanical properties of the coating and coating bond strength to develop optimized thermal spray parameters. To this end thermal spray coatings (FeAl and Fe3Al) have been applied to additional alloy substrates (Grade 91 steel, 316 SS, etc.) relevant to the fossil industry. Future plans also include a direct comparison to conventional weld overlay coatings currently used in the industry as well as exploration of new coatings. The room temperature mechanical strength and coating adhesion to the substrate is also of considerable importance. Eddy current methods are being developed to detect coating failure during room temperature tensile tests to optimize surface preparation as well as aid in the optimization of the HVOF thermal spray parameters.

  19. Thermal Shock-resistant Cement

    SciTech Connect (OSTI)

    Sugama T.; Pyatina, T.; Gill, S.

    2012-02-01

    We studied the effectiveness of sodium silicate-activated Class F fly ash in improving the thermal shock resistance and in extending the onset of hydration of Secar #80 refractory cement. When the dry mix cement, consisting of Secar #80, Class F fly ash, and sodium silicate, came in contact with water, NaOH derived from the dissolution of sodium silicate preferentially reacted with Class F fly ash, rather than the #80, to dissociate silicate anions from Class F fly ash. Then, these dissociated silicate ions delayed significantly the hydration of #80 possessing a rapid setting behavior. We undertook a multiple heating -water cooling quenching-cycle test to evaluate the cement’s resistance to thermal shock. In one cycle, we heated the 200 and #61616;C-autoclaved cement at 500 and #61616;C for 24 hours, and then the heated cement was rapidly immersed in water at 25 and #61616;C. This cycle was repeated five times. The phase composition of the autoclaved #80/Class F fly ash blend cements comprised four crystalline hydration products, boehmite, katoite, hydrogrossular, and hydroxysodalite, responsible for strengthening cement. After a test of 5-cycle heat-water quenching, we observed three crystalline phase-transformations in this autoclaved cement: boehmite and #61614; and #61543;-Al2O3, katoite and #61614; calcite, and hydroxysodalite and #61614; carbonated sodalite. Among those, the hydroxysodalite and #61614; carbonated sodalite transformation not only played a pivotal role in densifying the cementitious structure and in sustaining the original compressive strength developed after autoclaving, but also offered an improved resistance of the #80 cement to thermal shock. In contrast, autoclaved Class G well cement with and without Class F fly ash and quartz flour failed this cycle test, generating multiple cracks in the cement. The major reason for such impairment was the hydration of lime derived from the dehydroxylation of portlandite formed in the autoclaved cement, causing its volume to expand.

  20. Thermal, chemical, and mass-transport processes induced in abyssal sediments by the emplacement of nuclear waste: experimental and modeling results

    SciTech Connect (OSTI)

    McVey, D.F.; Erickson, K.L.; Seyfried, W.

    1980-01-01

    This paper discusses heat and mass transport studies of marine red clay sediments being considered as a nuclear waste isolation medium. Numerical models indicate that for a maximum allowable sediment/canister interface temperature of 200 to 250/sup 0/C, the sediment can absorb about 1.5 kW initial power from waste in a 3 m long by 0.3 m dia canister buried 30 m in the sediment. Fluid displacement due to convection is found to be less than 1 m. Laboratory studies of the geochemical effects induced by heating sediment/seawater mixtures indicate that the canister and waste form must be designed to resist a hot, acid (pH 3 to 4) oxidizing environment. Since the thermally altered sediment volume of about 5.5 m/sup 3/ is small relative to the sediment volume overlying the canister, the acid and oxidizing conditions are not anticipated to effect the properties of the far field. Using sorption coefficient correlations, the migration of four nuclides /sup 239/Pu, /sup 137/Cs, /sup 129/I, and /sup 99/Tc were computer for a canister buried 30 m deep in a 60 m thick red clay sediment layer. It was found that the /sup 239/Pu and /sup 137/Cs are essentially completely contained in the sediments, while /sup 129/I and /sup 99/Tc broke through the 30 m of sediment in about 5000 years. The resultant peak injection rates of 4.6 x 10/sup -5/ ..mu..Ci/year-m/sup 2/ for /sup 129/I and 1.6 x 10/sup -2/ ..mu..Ci/year-m/sup 2/ for /sup 99/Tc were less than the natural radioactive flux of /sup 226/Ra (3.5 to 8.8 x 10/sup -4/ ..mu..Ci/year-m/sup 2/) and /sup 222/Rn (0.26 to 0.88 ..mu..Ci/year-m/sup 2/).

  1. 2009 PILOT SCALE FLUIDIZED BED STEAM REFORMING TESTING USING THE THOR (THERMAL ORGANIC REDUCTION) PROCESS: ANALYTICAL RESULTS FOR TANK 48H ORGANIC DESTRUCTION - 10408

    SciTech Connect (OSTI)

    Williams, M.; Jantzen, C.; Burket, P.; Crawford, C.; Daniel, G.; Aponte, C.; Johnson, C.

    2009-12-28

    The Savannah River Site (SRS) must empty the contents of Tank 48H, a 1.3 million gallon Type IIIA HLW storage tank, to return this tank to service. The tank contains organic compounds, mainly potassium tetraphenylborate that cannot be processed downstream until the organic components are destroyed. The THOR{reg_sign} Treatment Technologies (TTT) Fluidized Bed Steam Reforming (FBSR) technology, herein after referred to as steam reforming, has been demonstrated to be a viable process to remove greater than 99.9% of the organics from Tank 48H during various bench scale and pilot scale tests. These demonstrations were supported by Savannah River Remediation (SRR) and the Department of Energy (DOE) has concurred with the SRR recommendation to proceed with the deployment of the FBSR technology to treat the contents of Tank 48H. The Savannah River National Laboratory (SRNL) developed and proved the concept with non-radioactive simulants for SRR beginning in 2003. By 2008, several pilot scale campaigns had been completed and extensive crucible testing and bench scale testing were performed in the SRNL Shielded Cells using Tank 48H radioactive sample. SRNL developed a Tank 48H non-radioactive simulant complete with organic compounds, salt, and metals characteristic of those measured in a sample of the radioactive contents of Tank 48H. FBSR Pilot Scaled Testing with the Tank 48H simulant has demonstrated the ability to remove greater than 98% of the nitrites and greater than 99.5% of the nitrates from the Tank 48H simulant, and to form a solid product that is primarily alkali carbonate. The alkali carbonate is soluble and, thus, amenable to pumping as a liquid to downstream facilities for processing. The FBSR technology was demonstrated in October of 2006 in the Engineering Scale Test Demonstration (ESTD) pilot scale steam reformer at the Hazen Research Inc. (HRI) facility in Golden, CO. Additional ESTD tests were completed in 2008 and in 2009 that further demonstrated the TTT steam reforming process ability to destroy organics in the Tank 48 simulant and produce a soluble carbonate waste form. The ESTD was operated at varying feed rates and Denitration and Mineralization Reformer (DMR) temperatures, and at a constant Carbon Reduction Reformer (CRR) temperature of 950 C. The process produced a dissolvable carbonate product suitable for processing downstream. ESTD testing was performed in 2009 at the Hazen facility to demonstrate the long term operability of an integrated FBSR processing system with carbonate product and carbonate slurry handling capability. The final testing demonstrated the integrated TTT FBSR capability to process the Tank 48 simulant from a slurry feed into a greater than 99.9% organic free and primarily dissolved carbonate FBSR product slurry. This paper will discuss the SRNL analytical results of samples analyzed from the 2008 and 2009 THOR{reg_sign} steam reforming ESTD performed with Tank 48H simulant at HRI in Golden, Colorado. The final analytical results will be compared to prior analytical results from samples in terms of organic, nitrite, and nitrate destruction.

  2. Methods of cracking a crude product to produce additional crude products

    DOE Patents [OSTI]

    Mo, Weijian (Sugar Land, TX); Roes, Augustinus Wilhelmus Maria (Houston, TX); Nair, Vijay (Katy, TX)

    2009-09-08

    A method for producing a crude product is disclosed. Formation fluid is produced from a subsurface in situ heat treatment process. The formation fluid is separated to produce a liquid stream and a first gas stream. The first gas stream includes olefins. The liquid stream is fractionated to produce one or more crude products. At least one of the crude products has a boiling range distribution from 38.degree. C. and 343.degree. C. as determined by ASTM Method D5307. The crude product having the boiling range distribution from 38.degree. C. and 343.degree. C. is catalytically cracked to produce one or more additional crude products. At least one of the additional crude products is a second gas stream. The second gas stream has a boiling point of at most 38.degree. C. at 0.101 MPa.

  3. Analogies between the cracking noise of ethanol-damped charcoal and earthquakes

    E-Print Network [OSTI]

    Ribeiro, H V; Alves, L G A; Santoro, P A; Picoli, S; Lenzi, E K; Mendes, R S

    2015-01-01

    We report on an extensive characterization of the cracking noise produced by charcoal samples when damped with ethanol. We argue that the evaporation of ethanol causes transient and irregularly distributed internal stresses that promotes the fragmentation of samples and mimic some situations found in mining process. The results show that, in general, the most fundamental seismic laws ruling earthquakes (Gutenberg-Richter law, unified scaling law for the recurrence times, Omori's law, productivity law and Bath's law) hold under the conditions of the experiment. Some discrepancies were also identified (a smaller exponent in Gutenberg-Richter law, a stationary behavior in the aftershocks rates for long times and a double power-law relationship in productivity law) and related to the different loading condition. Our results thus corroborate to elucidate the parallel between seismic laws and fracture experiments caused by a more complex loading condition that also occurs in natural and induced seismicity (such as ...

  4. Dependence of dynamic fracture resistance on crack velocity in tungsten: Pt. 1. Single crystals

    SciTech Connect (OSTI)

    Liv, J.M.; Shen, B.W.

    1984-06-01

    The dependence of dynamic fracture resistance on crack propagation velocity on (100) in tungsten has been examined. A correlation is obtained between the measured local crack velocity with the surfac and subsurface deformations. Based on the experimental results on one pass, two passes, and prestrained, electron beam zone refined single crystals, a discussion is given on the slip modes activated at the crack tip, the contributions to the dynamic fracture resistance from dislocations and surface features and from the preexisting deformed microstructure.

  5. Selective thermal and photooxidation of hydrocarbons in zeolites by oxygen

    DOE Patents [OSTI]

    Frei, Heinz (Berkeley, CA); Blatter, Fritz (Basel, CH); Sun, Hai (Saint Charles, MO)

    2001-01-01

    A process for a combined selective thermal oxidation and photooxidation of hydrocarbons adsorbed onto zeolite matrices. A highly combined selective thermal oxidation and photooxidation of unsubstituted or alkyl substituted alkanes, alkenes, aromatics and cycloalkyls in solvent free zeolites under dark thermal conditions or under irradiation with visible light. The process oxidizes hydrocarbons almost completely selectively without substantial production of byproducts.

  6. Selective thermal and photooxidation of hydrocarbons in zeolites by oxygen

    DOE Patents [OSTI]

    Frei, H.; Blatter, F.; Sun, H.

    1999-06-22

    A process is described for selective thermal oxidation or photooxidation of hydrocarbons adsorbed onto zeolite matrices. A highly selective thermal oxidation and photooxidation of unsubstituted or alkyl substituted alkanes, alkenes, aromatics and cycloalkyls in solvent free zeolites under dark thermal conditions or under irradiation with visible light. The process oxidizes hydrocarbons almost completely selectively without substantial production of byproducts. 19 figs.

  7. Selective thermal and photooxidation of hydrocarbons in zeolites by oxygen

    DOE Patents [OSTI]

    Frei, Heinz (Berkeley, CA); Blatter, Fritz (Basel, CH); Sun, Hai (Saint Charles, MO)

    1999-01-01

    A process for selective thermal oxidation or photooxidation of hydrocarbons adsorbed onto zeolite matrices. A highly selective thermal oxidation and photooxidation of unsubstituted or alkyl substituted alkanes, alkenes, aromatics and cycloalkyls in solvent free zeolites under dark thermal conditions or under irradiation with visible light. The process oxidizes hydrocarbons almost completely selectively without substantial production of byproducts.

  8. Selective thermal oxidation of hydrocarbons in zeolites by oxygen

    DOE Patents [OSTI]

    Frei, Heinz (Berkeley, CA); Blatter, Fritz (Basel, CH); Sun, Hai (Saint Charles, MO)

    2000-01-01

    A process for selective thermal oxidation of hydrocarbons adsorbed onto zeolite matrices. A highly selective thermal oxidation of unsubstituted or alkyl substituted alkanes, alkenes, aromatics and cycloalkyls is carried out in solvent free zeolites under dark thermal conditions. The process oxidizes hydrocarbons almost completely selectively without substantial production of byproducts.

  9. J-integral for a semi-elliptical surface crack at a bimaterial interface

    SciTech Connect (OSTI)

    Sharobeam, M.H.; Landes, J.D.

    1995-12-31

    Surface cracks are common defects in welded, bonded, and composite structures. The elastic-plastic fracture of these defects may be analyzed using the J-integral. The authors have recently developed a new approach to evaluate the J-integral for semi-elliptical surface cracks in panels made of homogeneous materials and subject to remote tension. This approach, which is based on load separation, allows the evaluation of J for such a three-dimensional geometry using a single specimen test record. It is analogous to the single specimen technique in two-dimensional geometries. In this article, the authors extend their study to surface cracks at bimaterial interfaces. A three-dimensional finite element model is developed to model such a crack. The J-integral is evaluated along the crack front using the virtual crack extension method. The elastic-plastic fracture behavior of the crack is studied. Load separation is also examined and the new single specimen approach for surface cracks in single material panels is extended to those at bimaterial interfaces. The study also includes a comparison between the results of surface cracks in single material panels and those at bimaterial interfaces.

  10. Simulation of the ultrasonic array response from real branched cracks using an efficient finite element method

    SciTech Connect (OSTI)

    Felice, Maria V. [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR, United Kingdom and Rolls-Royce plc., Bristol BS34 7QE (United Kingdom); Velichko, Alexander; Wilcox, Paul D. [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR (United Kingdom); Barden, Tim J.; Dunhill, Tony K. [Rolls-Royce plc., Bristol BS34 7QE (United Kingdom)

    2014-02-18

    A hybrid model to simulate the ultrasonic array response from stress corrosion cracks is presented. These cracks are branched and difficult to detect so the model is required to enable optimization of an array design. An efficient frequency-domain finite element method is described and selected to simulate the ultrasonic scattering. Experimental validation results are presented, followed by an example of the simulated ultrasonic array response from a real stress corrosion crack whose geometry is obtained from an X-ray Computed Tomography image. A simulation-assisted array design methodology, which includes the model and use of real crack geometries, is proposed.

  11. Standard test method for measurement of creep crack growth times in metals

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2007-01-01

    1.1 This test method covers the determination of creep crack growth (CCG) in metals at elevated temperatures using pre-cracked specimens subjected to static or quasi-static loading conditions. The time (CCI), t0.2 to an initial crack extension ?ai = 0.2 mm from the onset of first applied force and creep crack growth rate, ?a or da/dt is expressed in terms of the magnitude of creep crack growth relating parameters, C* or K. With C* defined as the steady state determination of the crack tip stresses derived in principal from C*(t) and Ct (1-14). The crack growth derived in this manner is identified as a material property which can be used in modeling and life assessment methods (15-25). 1.1.1 The choice of the crack growth correlating parameter C*, C*(t), Ct, or K depends on the material creep properties, geometry and size of the specimen. Two types of material behavior are generally observed during creep crack growth tests; creep-ductile (1-14) and creep-brittle (26-37). In creep ductile materials, where cr...

  12. Grain boundary chemistry effects on environment-induced crack growth of iron-based alloys

    SciTech Connect (OSTI)

    Jones, R.H.

    1992-11-01

    Relation between grain boundary chemistry and environment-induced crack growth of Fe-based alloys is reviewed. The importance of the cleanliness of steels is clearly demonstrated by direct relations between grain boundary chemistry and crack growth behavior for both H and anodic dissolution-induced crack growth. Relationships between strain to failure, work of fracture, K[sub ISCC], crack velocity and fracture mode and grain boundary chemistry are presented. Only results in which the grain boundary chemistry has been measured directly by Auger electron spectroscopy (AES) on intergranular surfaces exposed by in situ fracture have been considered in this review.

  13. Grain boundary chemistry effects on environment-induced crack growth of iron-based alloys

    SciTech Connect (OSTI)

    Jones, R.H.

    1992-11-01

    Relation between grain boundary chemistry and environment-induced crack growth of Fe-based alloys is reviewed. The importance of the cleanliness of steels is clearly demonstrated by direct relations between grain boundary chemistry and crack growth behavior for both H and anodic dissolution-induced crack growth. Relationships between strain to failure, work of fracture, K{sub ISCC}, crack velocity and fracture mode and grain boundary chemistry are presented. Only results in which the grain boundary chemistry has been measured directly by Auger electron spectroscopy (AES) on intergranular surfaces exposed by in situ fracture have been considered in this review.

  14. Investigation of cracking and leaking of nuclear reactor pools 

    E-Print Network [OSTI]

    Cooper, William Bernard

    1965-01-01

    . Typical Gage Points on Pool Wall 12 8. s, . Locations of Leakage b. Locations of Leakage c. Locations of Leakage 13 14 15 9 ~ Structural Model 10. Creep Test 11. Shrinkage of Various Concrete Specimens (Dry ), 12. Permeability Test 16 26 28...'LLCS H. ~ Typi cB1 LCBkage T)n Q13gi'I th 8 PQol Wall ~ ln 196Q~ ax attempt was made to control tbe leakage by grani, in~ =". lean cemert, mix Under' high pressure into the cracks in tbe concrete pool vail in. an attempt, to fill the existing voids...

  15. On the approximation of crack shapes found during inservice inspection

    SciTech Connect (OSTI)

    Bhate, S.R.; Chawla, D.S.; Kushwaha, H.S. [Bhabha Atomic Research Centre, Bombay (India)] [and others

    1997-04-01

    This paper addresses the characterization of axial internal flaw found during inservice inspection of a pipe. J-integral distribution for various flaw shapes is obtained using line spring finite, element method. The peak J-value and its distribution across the crack is found to be characteristic feature of each shape. The triangular shape yields peak J-value away from the center, the point of depth. The elliptic approximation results in large overestimate of J-value for unsymmetric flaws. Triangular approximation is recommended for such flaws so that further service can be obtained from the component.

  16. Recycling of wasted energy : thermal to electrical energy conversion

    E-Print Network [OSTI]

    Lim, Hyuck

    2011-01-01

    the consumed thermal energy, and this process can be greatlythermal energy to electric energy must be based on processesprocess of an indirect energy conversion system consists of multiple steps to convert thermal

  17. Synthesis and design of optimal thermal membrane distillation networks 

    E-Print Network [OSTI]

    Nyapathi Seshu, Madhav

    2006-10-30

    Thermal membrane distillation is one of the novel separation methods in the process industry. It involves the simultaneous heat and mass transfer through a hydrophobic semipermeable membrane through the use of thermal energy to bring about...

  18. Bayesian-based simulation model validation for spacecraft thermal systems

    E-Print Network [OSTI]

    Stout, Kevin Dale

    2015-01-01

    Over the last several decades of space flight, spacecraft thermal system modeling software has advanced significantly, but the model validation process, in general, has changed very little. Although most thermal systems ...

  19. High Temperature Thermal Array for Next Generation Solar Thermal...

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

    High Temperature Thermal Array for Next Generation Solar Thermal Power Production High Temperature Thermal Array for Next Generation Solar Thermal Power Production This...

  20. Nonadiabatic Spin Torque Investigated Using Thermally Activated Magnetic Domain Wall Dynamics

    E-Print Network [OSTI]

    Dunin-Borkowski, Rafal E.

    Nonadiabatic Spin Torque Investigated Using Thermally Activated Magnetic Domain Wall Dynamics M microscopy, we investigate the thermally activated motion of domain walls (DWs) between two positions properly analyzed, thermally activated processes at tem- peratures even well below the Curie temperature

  1. Energy-Saving Melting and Revert Reduction Technology (E-SMARRT): Use of Laser Engineered Net Shaping for Rapid Manufacturing of Dies with Protective Coatings and Improved Thermal Management

    SciTech Connect (OSTI)

    Brevick, Jerald R.

    2014-06-13

    In the high pressure die casting process, molten metal is introduced into a die cavity at high pressure and velocity, enabling castings of thin wall section and complex geometry to be obtained. Traditional die materials have been hot work die steels, commonly H13. Manufacture of the dies involves machining the desired geometry from monolithic blocks of annealed tool steel, heat treating to desired hardness and toughness, and final machining, grinding and polishing. The die is fabricated with internal water cooling passages created by drilling. These materials and fabrication methods have been used for many years, however, there are limitations. Tool steels have relatively low thermal conductivity, and as a result, it takes time to remove the heat from the tool steel via the drilled internal water cooling passages. Furthermore, the low thermal conductivity generates large thermal gradients at the die cavity surfaces, which ultimately leads to thermal fatigue cracking on the surfaces of the die steel. The high die surface temperatures also promote the metallurgical bonding of the aluminum casting alloy to the surface of the die steel (soldering). In terms of process efficiency, these tooling limitations reduce the number of die castings that can be made per unit time by increasing cycle time required for cooling, and increasing downtime and cost to replace tooling which has failed either by soldering or by thermal fatigue cracking (heat checking). The objective of this research was to evaluate the feasibility of designing, fabricating, and testing high pressure die casting tooling having properties equivalent to H13 on the surface in contact with molten casting alloy - for high temperature and high velocity molten metal erosion resistance – but with the ability to conduct heat rapidly to interior water cooling passages. A layered bimetallic tool design was selected, and the design evaluated for thermal and mechanical performance via finite element analysis. H13 was retained as the exterior layer of the tooling, while commercially pure copper was chosen for the interior structure of the tooling. The tooling was fabricated by traditional machining of the copper substrate, and H13 powder was deposited on the copper via the Laser Engineered Net Shape (LENSTM) process. The H13 deposition layer was then final machined by traditional methods. Two tooling components were designed and fabricated; a thermal fatigue test specimen, and a core for a commercial aluminum high pressure die casting tool. The bimetallic thermal fatigue specimen demonstrated promising performance during testing, and the test results were used to improve the design and LENS TM deposition methods for subsequent manufacture of the commercial core. Results of the thermal finite element analysis for the thermal fatigue test specimen indicate that it has the ability to lose heat to the internal water cooling passages, and to external spray cooling, significantly faster than a monolithic H13 thermal fatigue sample. The commercial core is currently in the final stages of fabrication, and will be evaluated in an actual production environment at Shiloh Die casting. In this research, the feasibility of designing and fabricating copper/H13 bimetallic die casting tooling via LENS TM processing, for the purpose of improving die casting process efficiency, is demonstrated.

  2. Effects of thermal fluctuations on thermal inflation

    E-Print Network [OSTI]

    Takashi Hiramatsu; Yuhei Miyamoto; Jun'ichi Yokoyama

    2014-12-25

    The mechanism of thermal inflation, a relatively short period of accelerated expansion after primordial inflation, is a desirable ingredient for a certain class of particle physics models if they are not to be in contention with the cosmology of the early Universe. Though thermal inflation is most simply described in terms of a thermal effective potential, a thermal environment also gives rise to thermal fluctuations that must be taken into account. We numerically study the effects of these thermal fluctuations using lattice simulations. We conclude that though they do not ruin the thermal inflation scenario, the phase transition at the end of thermal inflation proceeds through phase mixing and is therefore not accompanied by the formations of bubbles nor appreciable amplitude of gravitational waves.

  3. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    storage in solar thermal applications," Applied Energy, pp.of Non-Tracking Solar Thermal Technology," 2011. [26] R.C. Y. Zhao, "A review of solar collectors and thermal energy

  4. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    Evaporator Powered By Solar Thermal Energy 10:00 AM 10:00 AMaided or powered by solar thermal energy. A section is alsoexhaustive review of solar thermal energy systems has been

  5. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    and thermal energy storage in solar thermal applications,"Solar infrastructure should include analysis of thermal storage.storage equipment, the evaporator can be integrated into the current solar

  6. Low-Cracking High-Performance Concrete (LC-HPC) Bridge Decks: Shrinkage-Reducing Admixtures, Internal Curing, and Cracking Performance

    E-Print Network [OSTI]

    Pendergrass, Ben Andrew

    2014-05-31

    ABSTRACT The development, construction, and evaluation of low-cracking high-performance concrete (LC-HPC) bridge decks is described based on laboratory tests of mixtures containing shrinkage-reducing admixtures and mineral admixtures in conjunction...

  7. Modeling dynamic crack propagation in fiber reinforced composites including frictional effects q

    E-Print Network [OSTI]

    Espinosa, Horacio D.

    Modeling dynamic crack propagation in fiber reinforced composites including frictional effects q S Abstract Dynamic crack propagation in a unidirectional carbon/epoxy composite is studied through finite deformation anisotropic visco-plastic model is used to describe the constitutive response of the composite

  8. Cracks in martensite plates as hydrogen traps in a bearing steel

    E-Print Network [OSTI]

    Cambridge, University of

    Cracks in martensite plates as hydrogen traps in a bearing steel W. Solano-Alvareza , Eun Ju Songb stability requirements, and to improve the properties of the martensite [1]. Like most strong steels It is demonstrated that a macroscopically homogeneous distribution of tiny cracks introduced into a martensitic

  9. Theory of thin-skin eddy-current interaction with surface cracks N. Harfielda)

    E-Print Network [OSTI]

    Bowler, John R.

    Theory of thin-skin eddy-current interaction with surface cracks N. Harfielda) and J. R. Bowler; accepted for publication 14 July 1997 Eddy-current non-destructive evaluation is commonly performed of a typical crack. A thin-skin analysis of eddy currents is presented in which the electromagnetic fields

  10. THE ELASTIC-PLASTIC MECHANICS OF CRACK EXTENSION James R. Rice*

    E-Print Network [OSTI]

    THE ELASTIC-PLASTIC MECHANICS OF CRACK EXTENSION James R. Rice* ABSTRACT This paper briefly reviews progres~in the elastic plastic analysisof crack extension. Analytical results for plane strain and plane stress deformation fields are noted, and elastic-plastic fracture instability as well as transitional

  11. Mixed Mode Static and Fatigue Crack Growth in Wind Blade Paste Adhesives

    E-Print Network [OSTI]

    1 Mixed Mode Static and Fatigue Crack Growth in Wind Blade Paste Adhesives Daniel D. Samborsky, static GIc and mixed mode fracture, and fatigue crack growth resistance. I. Introduction Wind turbine, then adhesively bonded together. The large size coupled with cost constraints result in bond lines at least

  12. THE DYNAMICS OF RAPIDLY MOVING TENSILE CRACKS IN BRITTLE AMORPHOUS MATERIAL

    E-Print Network [OSTI]

    Fineberg, Jay

    initiated during the second World War. These theories generalized the concept of energy balance, which, and a corresponding sharp increase of the fracture energy with the mean crack velocity. We present experimental occurs when the potential elastic energy per unit area released by a unit extension of a crack is equal

  13. Robust damage assessment of multiple cracks based on the Frequency Response Function and the Constitutive Relation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Robust damage assessment of multiple cracks based on the Frequency Response Function a damage assessment technique for the non destructive detection and sizing of multiple open cracks in beams, many researchers have performed extensive investigations and damage assess- ment techniques based

  14. Assessing Hydrogen-Assisted Cracking Fracture Modes in High-Strength

    E-Print Network [OSTI]

    Eagar, Thomas W.

    I I Ii . I f. Assessing Hydrogen-Assisted Cracking Fracture Modes in High-Strength Steel Weldments Test results substantiate and extend the Beachem theory on hydrogen embrittlement ABSTRACT of the hydrogen content at the crack loca- tion. This relationship was used to assess previously proposed

  15. Statistical fracture modeling: crack path and fracture criteria with application to homogeneous and

    E-Print Network [OSTI]

    Ritchie, Robert

    Statistical fracture modeling: crack path and fracture criteria with application to homogeneous; accepted 23 January 2002 Abstract Analysis has been performed on fracture initiation near a crack in a brittle material with strength described by Weibull statistics. This nonlocal fracture model allows

  16. Brittle fracture in a periodic structure with internal potential energy. Spontaneous crack propagation

    E-Print Network [OSTI]

    Mark Ayzenberg-Stepanenko; Gennady Mishuris; Leonid Slepyan

    2014-02-12

    Spontaneous brittle fracture is studied based on the recently introduced model (Mishuris and Slepyan, Brittle fracture in a periodic structure with internal potential energy. Proc. Roy. Soc. A, in press). A periodic structure is considered, where only the prospective crack-path layer is specified as a discrete set of alternating initially stretched and compressed bonds. A bridged crack destroying initially stretched bonds may propagate under a certain level of the internal energy without external sources. The general analytical solution with the crack speed $-$ energy relation is presented in terms of the crack-related dynamic Green's function. For the anisotropic two-line chain and lattice considered earlier in quasi-statics, the dynamic problem is examined in detail. The crack speed is found to grow unboundedly as the energy approaches its upper limit. It is revealed that the spontaneous fracture can occur in the form of a pure bridged, partially bridged or fully open crack depending on the internal energy level. Generally, the steady-state mode of the crack propagation is found to be realised, whereas an irregular growth, clustering and the crack speed oscillations are detected in a vicinity of the lower bound of the energy.

  17. A stochastic model of fatigue crack propagation under variable-amplitude loading

    E-Print Network [OSTI]

    Ray, Asok

    -space model of fatigue crack propagation under variable-amplitude loading. The (non-stationary) statistic. Introduction Fatigue crack analysis is an essential tool for life prediction and maintenance of machinery/strain) factor b a constant model parameter larger than 1 (I 10) d increment operator DS eective stress range W 2

  18. Comparing Methods of Estimating Crack Volume in Shrink-Swell Soils 

    E-Print Network [OSTI]

    Rivera, Leonardo D.

    2011-08-04

    were measured on both soils. Vertical subsidence was measured at three locations in each soil with rods fixed at four depths. Rod movement was converted to soil crack volume by assuming equi-dimensional shrinkage. A second method for estimating crack...

  19. The roles of toughness and cohesive strength on crack deflection at

    E-Print Network [OSTI]

    Thouless, Michael

    composite systems. Brittle materials such as ceramics, concrete or epoxies can be toughened by the addition & Engineering University of Michigan Ann Arbor, MI 48109 August 30, 2005 Abstract In order to design composites and the matrix. If crack deflection does not occur, a crack propagating through the matrix will continue

  20. Fatigue-crack propagation in Nitinol, a shape-memory and superelastic endovascular stent material

    E-Print Network [OSTI]

    Ritchie, Robert

    Fatigue-crack propagation in Nitinol, a shape-memory and superelastic endovascular stent material A Nitinol. Specifically, the objective of this work was to study the effect of environ- ment on cyclic crack of Nitinol endovascular stents. The material selected for this study was heat treated

  1. Fracture toughness and crack-resistance curve behavior in metallic glass-matrix composites

    E-Print Network [OSTI]

    Ritchie, Robert

    Fracture toughness and crack-resistance curve behavior in metallic glass-matrix composites M. E of cracks, such as tensile ductil- ity, toughness, and fatigue resistance, can become severely compromised macroscopic ductility,3,4 such that the toughness is far lower than in comparable crystalline alloys

  2. Technical Note Fiducial marks as measures of thin film crack arrest toughness

    E-Print Network [OSTI]

    Volinsky, Alex A.

    Technical Note Fiducial marks as measures of thin film crack arrest toughness Alex A. Volinsky a Published by Elsevier Science Ltd. Keywords: Fiducial marks; Adhesion; Fracture; Delamination; Crack arrest). This technique was shown to work with ductile metallic films (Al, Cu, Au, Cr) [2,4­9,15], ceramic (Ta2N) [10

  3. EFFECT OF VISCOUS GRAIN BRIDGING ON CYCLIC FATIGUE-CRACK GROWTH IN MONOLITHIC CERAMICS

    E-Print Network [OSTI]

    Ritchie, Robert

    EFFECT OF VISCOUS GRAIN BRIDGING ON CYCLIC FATIGUE-CRACK GROWTH IN MONOLITHIC CERAMICS AT ELEVATED crack under cyclic loading conditions at elevated temperatures in high-toughness, monolithic ceramics the frequency and temperature sensitivity not gen- erally observed in ceramics at room temperature. Solutions

  4. Channel cracks in a hermetic coating consisting of organic and inorganic layers

    E-Print Network [OSTI]

    Suo, Zhigang

    Channel cracks in a hermetic coating consisting of organic and inorganic layers Nicolas Cordero 2007 Flexible electronic devices often require hermetic coatings that can withstand applied strains. This letter calculates the critical strains for various configurations of channel cracks in a coating

  5. Effect of elastic coating on fracture behaviour of piezoelectric fibre with a penny-shaped crack

    E-Print Network [OSTI]

    Qin, Qinghua

    Effect of elastic coating on fracture behaviour of piezoelectric fibre with a penny-shaped crack, Tianjin University, Tianjin 300072, China Abstract In this paper, the problem of a penny-shaped crack of piezoelectric fibre composites. Ó 2006 Elsevier Ltd. All rights reserved. Keywords: Piezoelectric fibre; Penny

  6. Thermo Tracer Infrared Thermal Imager

    E-Print Network [OSTI]

    Walker, D. Greg

    -range area G Environment monitoring Volcano, ecology, vegetation, global warming, pollution G R&D Evaluation is a fixed installation type infrared thermal imaging camera to monitor important facilities Production line monitoring Quality anomalies in production processes G Facility monitoring Anomalies

  7. Thermal Control & System Integration

    Broader source: Energy.gov [DOE]

    The thermal control and system integration activity focuses on issues such as the integration of motor and power control technologies and the development of advanced thermal control technologies....

  8. DNA Engine Thermal Cycler

    E-Print Network [OSTI]

    Raizada, Manish N.

    ® Peltier Thermal Cycler PTC-0200 DNA Engine Cycler Operations Manual Version 4.0 #12;ii Tech Support: 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .vi The DNA Engine® Peltier Thermal Cycler Introduction

  9. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    and C. Y. Zhao, "A review of solar collectors and thermalenergy storage in solar thermal applications," Appliedon photovoltaic/thermal hybrid solar technology," Applied

  10. AQUIFER THERMAL ENERGY STORAGE

    E-Print Network [OSTI]

    Tsang, C.-F.

    2011-01-01

    thermal energy becomes apparent with the development of solarsolar energy systems, aquifer energy storage provides a buffer between time-varying solar energy inputs and thermal

  11. Analysis of thermally-degrading, confined HMX

    SciTech Connect (OSTI)

    Hobbs, M.L.; Schmitt, R.G.; Renlund, A.M.

    1996-12-01

    The response of a thermally-degrading, confined HMX pellet is analyzed using a Reactive Elastic-Plastic (REP) constitutive model which is founded on the collapse and growth of internal inclusions resulting from physical and chemical processes such as forced displacement, thermal expansion, and/or decomposition. Axial stress predictions compare adequately to data. Deficiencies in the model and future directions are discussed.

  12. Fatigue crack propagation in a quasi one-dimensional elasto-plastic model

    E-Print Network [OSTI]

    Tomás M. Guozden; Eduardo A. Jagla

    2012-06-27

    Fatigue crack advance induced by the application of cyclic quasistatic loads is investigated both numerically and analytically using a lattice spring model. The system has a quasi-one-dimensional geometry, and consists in two symmetrical chains that are pulled apart, thus breaking springs which connect them, and producing the advance of a crack. Quasistatic crack advance occurs as a consequence of the plasticity included in the springs which form the chains, and that implies a history dependent stress-strain curve for each spring. The continuous limit of the model allows a detailed analytical treatment that gives physical insight of the propagation mechanism. This simple model captures key features that cause well known phenomenology in fatigue crack propagation, in particular a Paris-like law of crack advance under cyclic loading, and the overload retardation effect.

  13. Growth of geologic fractures into large-strain populations: review of nomenclature, subcritical crack growth, and some implications

    E-Print Network [OSTI]

    crack growth, and some implications for rock engineering R.A. Schultz* Geomechanics-Rock Fracture Group

  14. Review of industry efforts to manage pressurized water reactor feedwater nozzle, piping, and feedring cracking and wall thinning

    SciTech Connect (OSTI)

    Shah, V.N.; Ware, A.G.; Porter, A.M.

    1997-03-01

    This report presents a review of nuclear industry efforts to manage thermal fatigue, flow-accelerated corrosion, and water hammer damage to pressurized water reactor (PWR) feedwater nozzles, piping, and feedrings. The review includes an evaluation of design modifications, operating procedure changes, augmented inspection and monitoring programs, and mitigation, repair and replacement activities. Four actions were taken: (a) review of field experience to identify trends of operating events, (b) review of technical literature, (c) visits to PWR plants and a PWR vendor, and (d) solicitation of information from 8 other countries. Assessment of field experience is that licensees have apparently taken sufficient action to minimize feedwater nozzle cracking caused by thermal fatigue and wall thinning of J-tubes and feedwater piping. Specific industry actions to minimize the wall-thinning in feedrings and thermal sleeves were not found, but visual inspection and necessary repairs are being performed. Assessment of field experience indicates that licensees have taken sufficient action to minimize steam generator water hammer in both top-feed and preheat steam generators. Industry efforts to minimize multiple check valve failures that have allowed backflow of steam from a steam generator and have played a major role in several steam generator water hammer events were not evaluated. A major finding of this review is that analysis, inspection, monitoring, mitigation, and replacement techniques have been developed for managing thermal fatigue and flow-accelerated corrosion damage to feedwater nozzles, piping, and feedrings. Adequate training and appropriate applications of these techniques would ensure effective management of this damage.

  15. Model of crack propagation in a clay soil 

    E-Print Network [OSTI]

    Carriere, Patrick Edwidge

    1985-01-01

    of variance (ANOVA) to obtain the best selection to be included in the model. The ANOYA model was expressed by: Model = BO(H) + Bl(CL) + B2(M) + B3(H"M) + B4(H*CL) + B5(M*CL) + B6(H~M*CL) where: H = humidity effect, CL = clay content effect, M = initial.... 0280* T5 0. 7413 0. 5771 6. 16 0. 0001* T6 0. 2973 0. 2887 4. 94 0. 001* T7 0. 2065 0. 3432 2. 89 0. 0084* T8 0. 2543 0. 0767 15. 89 0. 0001* * significant at level 0. 05 30 Table 3. ANOVA results for crack de th. Source Sum of Degrees of Mean F...

  16. Specified pipe fittings susceptible to sulfide stress cracking

    SciTech Connect (OSTI)

    McIntyre, D.R.; Moore, E.M. Jr. [Saudi Aramco, Dhahran (Saudi Arabia)

    1996-01-01

    The NACE Standard MR0175 limit of HRC 22 is too high for cold-forged and stress-relieved ASTM A234 WPB pipe fittings. Hardness surveys and sulfide stress cracking test results per ASTM G 39 and NACE TM0177 Method B are presented to support this contention. More stringent inspection and a hardness limit of HB 197 (for cold-forged and stress-relieved fittings only) are recommended. The paper describes a case in which fittings were welded in place in wet sour service flow lines and gas-oil separating plants which were ready to start. The failure of a welded fitting shortly after start-up led to extensive field hardness testing on all fittings from this manufacturer.

  17. Surface Tension regularizes the Crack Singularity of Adhesive Contacts

    E-Print Network [OSTI]

    Stefan Karpitschka; Leen van Wijngaarden; Jacco H. Snoeijer

    2015-08-14

    The elastic and adhesive properties of a solid surface can be quantified by indenting it with a rigid sphere. Indentation tests are classically described by the JKR-law when the solid is very stiff, while recent work highlights the importance of surface tension for exceedingly soft materials. Here we show that surface tension plays a crucial role even for stiff solids: it regularizes the crack-like singularity at the edge of the contact. We find that the edge region exhibits a universal, self-similar structure that emerges from the balance of surface tension and elasticity. The similarity theory provides a complete description for adhesive contacts, reconciling the global adhesion laws and local contact mechanics.

  18. Automated crack control analysis for concrete pavement construction 

    E-Print Network [OSTI]

    Jang, Se Hoon

    2005-11-01

    and the subbase, and concrete shrinkage. Other factors relevant to concrete mixture characteristics such as cement content and type of coarse aggregate affect development of early aged stresses caused by shrinkage and thermally induced contraction. A probabilistic...

  19. CRACK GROWTH ANALYSIS OF SOLID OXIDE FUEL CELL ELECTROLYTES

    SciTech Connect (OSTI)

    S. Bandopadhyay; N. Nagabhushana

    2003-10-01

    Defects and Flaws control the structural and functional property of ceramics. In determining the reliability and lifetime of ceramics structures it is very important to quantify the crack growth behavior of the ceramics. In addition, because of the high variability of the strength and the relatively low toughness of ceramics, a statistical design approach is necessary. The statistical nature of the strength of ceramics is currently well recognized, and is usually accounted for by utilizing Weibull or similar statistical distributions. Design tools such as CARES using a combination of strength measurements, stress analysis, and statistics are available and reasonably well developed. These design codes also incorporate material data such as elastic constants as well as flaw distributions and time-dependent properties. The fast fracture reliability for ceramics is often different from their time-dependent reliability. Further confounding the design complexity, the time-dependent reliability varies with the environment/temperature/stress combination. Therefore, it becomes important to be able to accurately determine the behavior of ceramics under simulated application conditions to provide a better prediction of the lifetime and reliability for a given component. In the present study, Yttria stabilized Zirconia (YSZ) of 9.6 mol% Yttria composition was procured in the form of tubes of length 100 mm. The composition is of interest as tubular electrolytes for Solid Oxide Fuel Cells. Rings cut from the tubes were characterized for microstructure, phase stability, mechanical strength (Weibull modulus) and fracture mechanisms. The strength at operating condition of SOFCs (1000 C) decreased to 95 MPa as compared to room temperature strength of 230 MPa. However, the Weibull modulus remains relatively unchanged. Slow crack growth (SCG) parameter, n = 17 evaluated at room temperature in air was representative of well studied brittle materials. Based on the results, further work was planned to evaluate the strength degradation, modulus and failure in more representative environment of the SOFCs.

  20. Repeated compressive stress increase with 400 [degree]C thermal cycling in tantalum thin films due to increases in the oxygen content

    SciTech Connect (OSTI)

    Cabral, C. Jr.; Clevenger, L.A.; Schad, R.G. )

    1994-07-01

    Stresses which build up in thin films such as tantalum, during thermal processing, can cause major reliability problems in electronic and x-ray optics applications. We demonstrate that 50--200 nm thick sputtered [beta]-Ta thin films undergo repeated compressive stress increases when thermally cycled to 400 [degree]C (at a rate of 10 [degree]C/min) and back in a purified He ambient because of small amounts of oxygen gettered by the tantalum. The oxygen contamination results from the poor quality of the atmospheric seal on the quartz annealing chamber. As-deposited Ta thin films have a compressive stress ranging from [minus]1 to [minus]4 GPa. The compressive stress buildup was monitored [ital in] [ital situ] and was shown to increase [minus]0.5 GPa on average after each thermal cycle for a final value from [minus]6 to [minus]7 GPa after seven cycles. After being cycled thermally seven times any perturbation of the film such as a four-point probe resistivity measurement can cause the film to instantaneously crack in a serpentine pattern, relieving the large compressive stress. Auger electron spectroscopy depth profiling analysis was used to determine that the as-deposited film contained 1 at. % oxygen which increased to 8%--12% after seven thermal cycles with an approximate doubling in resistivity. The [minus]0.5 GPa average compressive stress increase in Ta thin films when cycled to 400 [degree]C is attributed to a 1.3% increase in oxygen concentration leading to a Ta unit cell expansion of 0.6%.

  1. Thermal Regimes of Northeast Streams

    E-Print Network [OSTI]

    Thermal Loading (USGS) Stormwater and Streams ­ Optimizing Stormwater Management to Protect the Thermal

  2. SRNL SHELF LIFE STUDIES - SCC STUDIES AT ROOM TEMPERTURE [stress corrosion cracking

    SciTech Connect (OSTI)

    Mickalonis, J.; Duffey, J.

    2014-11-12

    Phase II, Series 2 corrosion testing performed by the Savannah River National Laboratory (SRNL) for the Department of Energy 3013 container has been completed. The corrosion tests are part of an integrated plan conducted jointly by Los Alamos National Laboratory and the Savannah River Site. SRNL was responsible for conducting corrosion studies in small-scale vessels to address the influence of salt composition, water loading, and type of oxide/salt contact on the relative humidity inside a 3013 container and on the resulting corrosion of Type 304L and 316L stainless steel (304L and 316L). This testing was conducted in two phases: Phase I evaluated a broad spectrum of salt compositions and initial water loadings on the salt mixtures exposed to 304L and 316L and the resulting corrosion; Phase II evaluated the corrosion of 304L at specific water loadings and a single salt composition. During Phase I testing at high initial moisture levels (0.35 to 1.24 wt%)a, the roomtemperature corrosion of 304L exposed to a series of plutonium oxide/chloride salt mixtures ranged from superficial staining to pitting and stress corrosion cracking (SCC). 304L teardrop coupons that exhibited SCC were directly exposed to a mixture composed of 98 wt % PuO2, 0.9 wt % NaCl, 0.9 wt % KCl, and 0.2 wt % CaCl2. Cracking was not observed in a 316L teardrop coupon. Pitting was also observed in this environment for both 304L and 316L with depths ranging from 20 to 100 ?m. Neither pitting nor SCC was observed in mixtures with a greater chloride salt concentration (5 and 28 wt%). These results demonstrated that for a corrosive solution to form a balance existed between the water loading and the salt chloride concentration. This chloride solution results from the interaction of loaded water with the hydrating CaCl2 salt. In Phase II, Series 1 tests, the SCC results were shown to be reproducible with cracking occurring in as little as 85 days. The approximate 0.5 wt% moisture level was found to result in an initial relative humidity of ~55% within the small-scale vessels. Pits were found to be associated with cracks and appeared to act as initiators for the cracking. In a vapor-space only exposure, the weld oxide, which results from the TIG closure weld used to fabricate the teardrop coupon, was also shown to be more susceptible to pitting corrosion than a surface free from weld oxide. This result has important implications for the closure weld of the 3013 inner can since the weld oxide on the can internal surface cannot be removed. The results from the Phase II, Series 2 tests further demonstrated the significance of forming a solution with a critical chloride concentration for corrosion to proceed. 304L teardrop coupons were found to corrode only by pitting with a similar oxide/salt mixture as used in Series 1 testing but with a lower water loading of 0.2 wt%, which resulted in an initial relative humidity of 35-38%. These tests ran twice as long as those for Series 1 testing. The exposure condition was also found to impact the corrosion with salt-exposed surfaces showing lower corrosion resistance. Additional analyses of the Series 2 coupons are recommended especially for determining if cracks emanate from the bottom of pits. Data generated under the 2009 3013 corrosion test plan, as was presented here, increased the understanding of the corrosion process within a sealed 3013 container. Along with the corrosion data from destructive evaluations of 3013 containers, the inner can closure weld region (ICCWR) has been identified as the most vulnerable area of the inner can where corrosion may lead to corrosive species leaking to the interior surface of the outer container, thereby jeopardizing the integrity of the 3013 container. A new corrosion plan has been designed that will characterize the corrosion at the ICCWR of 3013 DEs as well as parameters affecting this corrosion.

  3. Fundamentals of fluidized bed chemical processes

    SciTech Connect (OSTI)

    Yates, J.G.

    1983-01-01

    Chemical processes based on the use of fluidized solids, although widely used on an industrial scale for some four decades, are currently increasing in importance as industry looks for improved methods for handling and reacting solid materials. This book provides background necessary for an understanding of the technique of gas-solid fluidization. Contents: Some Fundamental Aspects of Fluidization-General Features of Gas-Solid Fluidization; Minimum Fluidization Velocity; Inter-particle forces; Liquid-Solid Fluidization; Bubbles; Slugging; Entrainment and Elutriation; Particle Movement; Bed Viscosity; Fluidization Under Pressure. Fluidized-Bed Reactor Models-ome Individual Models; Model Comparisons; Multiple Region Models. Catalytic Cracking-Process Developments Riser Cracking; Catalysis; Process Chemistry; Kinetics; Process Models. Combustion and Gasification-Plant Developments; Oil and Gas Combustion; Desulphurization; No/sub x/ Emissions; Coal Gassification. Miscellaneous Processes-Phthalic Anhydride (1,3-isobezofurandione); Acrylonitrile (prop-3-enenitrile); Vinyl Chloride (chloroethene); Titanium Dioxide; Uranium Processing; Sulphide Roasting; Indexes.

  4. THERMAL PROCESSES GOVERNING HOT-JUPITER RADII

    SciTech Connect (OSTI)

    Spiegel, David S.; Burrows, Adam E-mail: burrows@astro.princeton.edu

    2013-07-20

    There have been many proposed explanations for the larger-than-expected radii of some transiting hot Jupiters, including either stellar or orbital energy deposition deep in the atmosphere or deep in the interior. In this paper, we explore the important influences on hot-Jupiter radius evolution of (1) additional heat sources in the high atmosphere, the deep atmosphere, and deep in the convective interior; (2) consistent cooling of the deep interior through the planetary dayside, nightside, and poles; (3) the degree of heat redistribution to the nightside; and (4) the presence of an upper atmosphere absorber inferred to produce anomalously hot upper atmospheres and inversions in some close-in giant planets. In particular, we compare the radius expansion effects of atmospheric and deep-interior heating at the same power levels and derive the power required to achieve a given radius increase when night-side cooling is incorporated. We find that models that include consistent day/night cooling are more similar to isotropically irradiated models when there is more heat redistributed from the dayside to the nightside. In addition, we consider the efficacy of ohmic heating in the atmosphere and/or convective interior in inflating hot Jupiters. Among our conclusions are that (1) the most highly irradiated planets cannot stably have uB {approx}> 10 km s{sup -1} G over a large fraction of their daysides, where u is the zonal wind speed and B is the dipolar magnetic field strength in the atmosphere, and (2) that ohmic heating cannot in and of itself lead to a runaway in planet radius.

  5. Materials Selection Considerations for Thermal Process Equipment...

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

    productivity and operating cost of the equipment. These materials are used in burners, electrical heating elements, material handling, load support, and heater tubes, etc....

  6. Thermal Plasma Systems for Industrial Processes 

    E-Print Network [OSTI]

    Fey, M. G.; Meyer, T. N.; Reed, W. H.; Philbrook, W. O.

    1982-01-01

    , metallurgical, and specialty materials areas. The applications for plasma systems to be discussed in this paper include: blast furnace conversions, direct reduction or iron ore, hot blast superheating and hydrocarbon pyrolysis. Both the technical and economic...

  7. Method For Brazing And Thermal Processing

    DOE Patents [OSTI]

    Milewski, John O. (Santa Fe, NM); Dave, Vivek R. (Los Alamos, NM); Christensen, Dane (Livermore, CA); Carpenter, II, Robert W. (Los Alamos, NM)

    2005-07-12

    The present invention includes a method for brazing of two objects or heat treatment of one object. First, object or objects to be treated are selected and initial conditions establishing a relative geometry and material characteristics are determined. Then, a first design of an optical system for directing heat energy onto the object or objects is determined. The initial conditions and first design of the optical system are then input into a optical ray-tracing computer program. The program is then run to produce a representative output of the heat energy input distribution to the object or objects. The geometry of the object or objects, material characteristics, and optical system design are then adjusted until an desired heat input is determined.

  8. Continuous Processing of High Thermal Conductivity Polyethylene...

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

    conductivity polyethylene fibers and sheets will be developed to replace metals and ceramics in heat-transfer devices. Project innovations include using massively parallel...

  9. Fatigue cracking of a bare steel first wall in an inertial confinement fusion chamber

    SciTech Connect (OSTI)

    Hunt, R. M.; Abbott, R. P.; Havstad, M. A.; Dunne, A. M.

    2013-06-01

    Inertial confinement fusion power plants will deposit high energy X-rays onto the outer surfaces of the first wall many times a second for the lifetime of the plant. These X-rays create brief temperature spikes in the first few microns of the wall, which cause an associated highly compressive stress response on the surface of the material. The periodicity of this stress pulse is a concern due to the possibility of fatigue cracking of the wall. We have used finite element analyses to simulate the conditions present on the first wall in order to evaluate the driving force of crack propagation on fusion-facing surface cracks. Analysis results indicate that the X-ray induced plastic compressive stress creates a region of residual tension on the surface between pulses. This tension film will likely result in surface cracking upon repeated cycling. Additionally, the compressive pulse may induce plasticity ahead of the crack tip, leaving residual tension in its wake. However, the stress amplitude decreases dramatically for depths greater than 80–100 ?m into the fusion-facing surface. Crack propagation models as well as stress-life estimates agree that even though small cracks may form on the surface of the wall, they are unlikely to propagate further than 100 ?m without assistance from creep or grain erosion phenomena.

  10. Fracture analysis of axially cracked pressure tube of pressurized heavy water reactor

    SciTech Connect (OSTI)

    Krishnan, S.; Bhasin, V.; Mahajan, S.C. [Bhabha Atomic Research Centre, Bombay (India)] [and others

    1997-04-01

    Three Dimensional (313) finite element elastic plastic fracture analysis was done for through wall axially cracked thin pressure tubes of 220 MWe Indian Pressurized Heavy Water Reactor. The analysis was done for Zr-2 and Zr-2.5Nb pressure tubes operating at 300{degrees}C and subjected to 9.5 Mpa internal pressure. Critical crack length was determined based on tearing instability concept. The analysis included the effect of crack face pressure due to the leaking fluid from tube. This effect was found to be significant for pressure tubes. The available formulae for calculating J (for axially cracked tubes) do not take into account the effect of crack face pressure. 3D finite element analysis also gives insight into variation of J across the thickness of pressure tube. It was observed that J is highest at the mid-surface of tube. The results have been presented in the form of across the thickness average J value and a peak factor on J. Peak factor on J is ratio of J at mid surface to average J value. Crack opening area for different cracked lengths was calculated from finite element results. The fracture assessment of pressure tubes was also done using Central Electricity Generating Board R-6 method. Ductile tearing was considered.

  11. Holographic thermalization of charged operators

    E-Print Network [OSTI]

    Alejandro Giordano; Nicolas E. Grandi; Guillermo A. Silva

    2014-12-26

    We study a light-like charged collapsing shell in AdS-Reissner-Nordstrom spacetime, investigating whether the corresponding Vaidya metric is supported by matter that satisfies the null energy condition. We find that, if the absolute value of the charge decreases during the collapse, energy conditions are fulfilled everywhere in spacetime. On the other hand, if the absolute value of the charge increases, the metric does not satisfy energy conditions in the IR region. Therefore, from the gauge/gravity perspective, this last case is only useful to study the thermalization of the UV degrees of freedom. For all these geometries, we probe the thermalization process with two point correlators of charged operators, finding that the thermalization time grows with the charge of the operator, as well as with the dimension of space.

  12. Technique development for field inspection of cracking in seam welded ducts

    SciTech Connect (OSTI)

    Shell, Eric B.; Benson, Craig [Wyle Laboratories, Inc., Dayton, OH 45440 (United States); Liljestrom, Greg C.; Shanahan, Stephen [Wyle Laboratories, Inc., Oklahoma City, OK 73110 (United States)

    2014-02-18

    The resistance seam weld interfaces between alloyed and pure titanium are an in service concern due to precipitation of titanium hydride and resulting embrittlement and cracking. Several inspection techniques were developed and evaluated for field use to characterize the damage in the fleet. Electromagnetic, ultrasonic, florescent penetrant, thermographic, and radiographic techniques were considered. The ultrasonic and electromagnetic approaches were both found suitable. However, the electromagnetic approach is more desirable for field inspections, due to consistency and ease of use. The electromagnetic inspection procedure is able to discriminate between precursor damage and through cracking with sufficient sensitivity to small cracks.

  13. HEATS: Thermal Energy Storage

    SciTech Connect (OSTI)

    2012-01-01

    HEATS Project: The 15 projects that make up ARPA-E’s HEATS program, short for “High Energy Advanced Thermal Storage,” seek to develop revolutionary, cost-effective ways to store thermal energy. HEATS focuses on 3 specific areas: 1) developing high-temperature solar thermal energy storage capable of cost-effectively delivering electricity around the clock and thermal energy storage for nuclear power plants capable of cost-effectively meeting peak demand, 2) creating synthetic fuel efficiently from sunlight by converting sunlight into heat, and 3) using thermal energy storage to improve the driving range of electric vehicles (EVs) and also enable thermal management of internal combustion engine vehicles.

  14. Stress corrosion cracking of steel Stressed-Out Metals: Predicting their Response from the Bottom Up

    E-Print Network [OSTI]

    Simons, Jack

    Stress corrosion cracking of steel Stressed-Out Metals: Predicting their Response from the Bottom;Shocked Iron Ground state bcc undergoes a martensitic phase transformation to hcp at ~13 GPa

  15. Cracked lifting lug welds on ten-ton UF{sub 6} cylinders

    SciTech Connect (OSTI)

    Dorning, R.E. [Martin Marietta Energy Systems, Inc., Piketon, OH (United States)

    1991-12-31

    Ten-ton, Type 48X, UF{sub 6} cylinders are used at the Portsmouth Gaseous Diffusion Plant to withdraw enriched uranium hexafluoride from the cascade, transfer enriched uranium hexafluoride to customer cylinders, and feed enriched product to the cascade. To accomplish these activities, the cylinders are lifted by cranes and straddle carriers which engage the cylinder lifting lugs. In August of 1988, weld cracks on two lifting lugs were discovered during preparation to lift a cylinder. The cylinder was rejected and tagged out, and an investigating committee formed to determine the cause of cracking and recommend remedial actions. Further investigation revealed the problem may be general to this class of cylinder in this use cycle. This paper discusses the actions taken at the Portsmouth site to deal with the cracked lifting lug weld problem. The actions include inspection activities, interim corrective actions, metallurgical evaluation of cracked welds, weld repairs, and current monitoring/inspection program.

  16. Keep Customers-and Energy-From Slipping Through the Cracks |...

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

    Keep Customers-and Energy-From Slipping Through the Cracks A photo of three people standing and talking to each other, two men and a woman, inside a home. The most successful...

  17. August 27, 2006 CRACKING OF LAMINATES SUBJECTED TO BIAXIAL TENSILE STRAINS

    E-Print Network [OSTI]

    Suo, Zhigang

    ] developed a strain energy release rate expression for the tunnel crack in layers subjected to biaxial tensile stress in the zirconia layer [14] r = r EZr 1- Zr 1+ t w EZr / 1- Zr( ) EAl/ Zr / 1- Al / Zr

  18. Integrating Gas Turbines with Cracking Heaters - Impact on Emissions and Energy Efficiency 

    E-Print Network [OSTI]

    Platvoet, E.

    2011-01-01

    Turbine Exhaust Gas (TEG) contains high levels of oxygen, typically 15 vol. percent, due to gas turbine blade material temperature limits. As such it can be used as an oxidant for combustion in cracking furnaces and reformers. Its high temperature...

  19. 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...

  20. Linear elastic fracture mechanics in anisotropic solids : application to fluid-driven crack propagation

    E-Print Network [OSTI]

    Laubie, Hadrien Hyacinthe

    2013-01-01

    Fracture mechanics is a field of continuum mechanics with the objective to predict how cracks initiate and propagate in solids. It has a wide domain of application. While aerospace engineers want to make sure a defect in ...

  1. Fatigue failure in thin-film polysilicon is due to subcritical cracking within the oxide layer

    E-Print Network [OSTI]

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

    2005-01-01

    and manual fracture: no oxide layer thickening (principalCRACKING WITHIN THE OXIDE LAYER D. H. Alsem, a),b),c) E. A.air with thickened oxide layer around the notch root (

  2. Effect of Voids on the Crack Kinking in Single Lap Joints 

    E-Print Network [OSTI]

    Sengab, Ahmed M

    2015-05-12

    Polymer matrix composites are used extensively for their exceptional mechanical properties. The effect of voids on the energy release rate of interface crack has been studied before; however none of the studies investigated ...

  3. Integral identities for a semi-infinite interfacial crack in 2D and 3D elasticity

    E-Print Network [OSTI]

    Piccolroaz, Andrea

    2011-01-01

    The paper is concerned with the problem of a semi-infinite crack at the interface between two dissimilar elastic half-spaces, loaded by a general asymmetrical system of forces distributed along the crack faces. On the basis of the weight function approach and the fundamental reciprocal identity (Betti formula), we formulate the elasticity problem in terms of singular integral equations relating the applied loading and the resulting crack opening. Such formulation is fundamental in the theory of elasticity and extensively used to solve several problems in linear elastic fracture mechanics (for instance various classic crack problems in homogeneous and heterogeneous media). This formulation is also crucial in important recent multiphysics applications, where the elastic problem is coupled with other concurrent physical phenomena. A paradigmatic example is hydraulic fracturing, where the elasticity equations are coupled with fluid dynamics.

  4. Integral identities for a semi-infinite interfacial crack in 2D and 3D elasticity

    E-Print Network [OSTI]

    Andrea Piccolroaz; Gennady Mishuris

    2012-06-06

    The paper is concerned with the problem of a semi-infinite crack at the interface between two dissimilar elastic half-spaces, loaded by a general asymmetrical system of forces distributed along the crack faces. On the basis of the weight function approach and the fundamental reciprocal identity (Betti formula), we formulate the elasticity problem in terms of singular integral equations relating the applied loading and the resulting crack opening. Such formulation is fundamental in the theory of elasticity and extensively used to solve several problems in linear elastic fracture mechanics (for instance various classic crack problems in homogeneous and heterogeneous media). This formulation is also crucial in important recent multiphysics applications, where the elastic problem is coupled with other concurrent physical phenomena. A paradigmatic example is hydraulic fracturing, where the elasticity equations are coupled with fluid dynamics.

  5. Effect of oxygen potential on high temperature crack growth in alloy 617

    E-Print Network [OSTI]

    Benz, Julian K

    2009-01-01

    The effect of oxygen partial pressure on crack growth rates in Alloy 617 has been studied using both static and fatigue loading at 650°C. Tests were conducted at a constant stress intensity factor, K, for static loading ...

  6. Electrical Impedance Tomographic Methods for Sensing Strain Fields and Crack Damage in Cementitious Structures

    E-Print Network [OSTI]

    Lynch, Jerome P.

    of their origins (Bungey et al., 2006). After suspicious cracks are encountered, non- destructive (for example, ultrasonic inspection) and partially destructive (for example, core holes) testing can be carried out

  7. On the fracture toughness of ferroelectric ceramics with electric field applied parallel to the crack front

    E-Print Network [OSTI]

    On the fracture toughness of ferroelectric ceramics with electric field applied parallel crack growth. The effects of electric field on the fracture toughness of both initially unpoled and poled materials are investigated. Results for the predicted fracture toughness, remanent strain

  8. Spatial and Temporal Distribution of Desiccation Cracks in Shrink-Swell Soils 

    E-Print Network [OSTI]

    Neely, Haly Lury

    2014-04-17

    Soil crack volume estimates, which are important for hydrology models on shrink-swell soils, are currently based on field measurements of vertical shrinkage and an assumption of isotropic shrinkage; however, few studies have validated the resulting...

  9. A program to design asphalt concrete overlays to mitigate reflection cracking 

    E-Print Network [OSTI]

    Satyanarayana Rao, Sindhu

    2002-01-01

    . Various engineering reinforcing grids have been used in recent years to mitigate the occurrence and propagation of reflection cracking. Reinforcing grids made of fiberglass or polypropylene has been used for this purpose. The main objectives...

  10. Analytical Investigation of Repair Methods for Fatigue Cracks in Steel Bridges

    E-Print Network [OSTI]

    Richardson, Temple

    2012-08-31

    Numerous retrofits have been used to stop distortion-induced fatigue cracks from initiating and propagating in steel bridges. Some decrease stiffness in the web gap region to transfer the load path to an area of higher stiffness, while others...

  11. Webinar: Impacts of Impurities on Hydrogen Assisted Fatigue Crack Growth in Structural Steels

    Broader source: Energy.gov [DOE]

    The Energy Department will present a live webinar titled "Impacts of Impurities on Hydrogen Assisted Fatigue Crack Growth in Structural Steels" on Tuesday, January 12, from 12 to 1 p.m. EST.

  12. Evaluation of the filler effects on fatique cracking and permanent deformation of asphalt concrete mixtures 

    E-Print Network [OSTI]

    Izzo, Richard P

    1997-01-01

    The addition of hydrated lime to asphalt has shown to be beneficial with an improvement in the Theological properties of the binder, as well as resistance to permanent deformation (rutting) and fatigue cracking of asphalt concrete mixtures...

  13. Identification of asphalt binder properties that affect cracking performance of hot mixed asphalt concrete pavements 

    E-Print Network [OSTI]

    Hastings, Charles Patrick

    1997-01-01

    with the original mixture designs, compacted in the laboratory, and tested using the National Cooperative Highway Research Program (NCHRP) asphalt aggregate mixture analysis system (AAMAS) test protocols to assess relative resistance to fatigue cracking. Field cores...

  14. Reaction kinetics of olefin saturation in the hydrodesulfurization of fluid catalytic cracked naphtha 

    E-Print Network [OSTI]

    Schumann, Brian Herbert

    1995-01-01

    U.S. governmental agencies are calling for strict environmental regulations on the quality of gasoline. Fluid catalytic cracked naphtha is an important blending component of the gasoline pool. The majority of the sulfur in the gasoline pool comes...

  15. Thermal and Electrical Transport in Oxide Heterostructures

    E-Print Network [OSTI]

    Ravichandran, Jayakanth

    2011-01-01

    of thermal conductivity . . . . . . . . . . . . . . . .4.4 Thermal transport in2.3.2 Thermal transport . . . . . . . . . . . . . . . .

  16. Methodology for extracting local constants from petroleum cracking flows

    DOE Patents [OSTI]

    Chang, Shen-Lin (Woodridge, IL); Lottes, Steven A. (Naperville, IL); Zhou, Chenn Q. (Munster, IN)

    2000-01-01

    A methodology provides for the extraction of local chemical kinetic model constants for use in a reacting flow computational fluid dynamics (CFD) computer code with chemical kinetic computations to optimize the operating conditions or design of the system, including retrofit design improvements to existing systems. The coupled CFD and kinetic computer code are used in combination with data obtained from a matrix of experimental tests to extract the kinetic constants. Local fluid dynamic effects are implicitly included in the extracted local kinetic constants for each particular application system to which the methodology is applied. The extracted local kinetic model constants work well over a fairly broad range of operating conditions for specific and complex reaction sets in specific and complex reactor systems. While disclosed in terms of use in a Fluid Catalytic Cracking (FCC) riser, the inventive methodology has application in virtually any reaction set to extract constants for any particular application and reaction set formulation. The methodology includes the step of: (1) selecting the test data sets for various conditions; (2) establishing the general trend of the parametric effect on the measured product yields; (3) calculating product yields for the selected test conditions using coupled computational fluid dynamics and chemical kinetics; (4) adjusting the local kinetic constants to match calculated product yields with experimental data; and (5) validating the determined set of local kinetic constants by comparing the calculated results with experimental data from additional test runs at different operating conditions.

  17. In situ investigation of high humidity stress corrosion cracking of 7075 aluminum alloy by three-dimensional (3D) X-ray synchrotron tomography

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

    Singh, S. S.; Williams, J. J.; Lin, M. F.; Xiao, X.; De Carlo, F.; Chawla, N.

    2014-05-14

    In situ X-ray synchrotron tomography was used to investigate the stress corrosion cracking behavior of under-aged Al–Zn–Mg–Cu alloy in moisture. The discontinuous surface cracks (crack jumps) mentioned in the literature are actually a single continuous and tortuous crack when observed in three dimension (3D). Contrary to 2D measurements made at the surface which suggest non-uniform crack growth rates, 3D measurements of the crack length led to a much more accurate measurement of crack growth rates.

  18. Underground Coal Thermal Treatment

    SciTech Connect (OSTI)

    P. Smith; M. Deo; E. Eddings; A. Sarofim; K. Gueishen; M. Hradisky; K. Kelly; P. Mandalaparty; H. Zhang

    2011-10-30

    The long-term objective of this work is to develop a transformational energy production technology by insitu thermal treatment of a coal seam for the production of substitute natural gas (SNG) while leaving much of the coalâ??s carbon in the ground. This process converts coal to a high-efficiency, low-GHG emitting gas fuel. It holds the potential of providing environmentally acceptable access to previously unusable coal resources. This topical report discusses the development of experimental capabilities, the collection of available data, and the development of simulation tools to obtain process thermo-chemical and geo-thermal parameters in preparation for the eventual demonstration in a coal seam. It also includes experimental and modeling studies of CO{sub 2} sequestration. Efforts focused on: â?˘ Constructing a suite of three different coal pyrolysis reactors. These reactors offer the ability to gather heat transfer, mass transfer and kinetic data during coal pyrolysis under conditions that mimic in situ conditions (Subtask 6.1). â?˘ Studying the operational parameters for various underground thermal treatment processes for oil shale and coal and completing a design matrix analysis for the underground coal thermal treatment (UCTT). This analysis yielded recommendations for terms of targeted coal rank, well orientation, rubblization, presence of oxygen, temperature, pressure, and heating sources (Subtask 6.2). â?˘ Developing capabilities for simulating UCTT, including modifying the geometry as well as the solution algorithm to achieve long simulation times in a rubblized coal bed by resolving the convective channels occurring in the representative domain (Subtask 6.3). â?˘ Studying the reactive behavior of carbon dioxide (CO{sub 2}) with limestone, sandstone, arkose (a more complex sandstone) and peridotite, including mineralogical changes and brine chemistry for the different initial rock compositions (Subtask 6.4). Arkose exhibited the highest tendency of participating in mineral reactions, which can be attributed to the geochemical complexity of its initial mineral assemblage. In experiments with limestone, continuous dissolution was observed with the release of CO{sub 2} gas, indicated by the increasing pressure in the reactor (formation of a gas chamber). This occurred due to the lack of any source of alkali to buffer the solution. Arkose has the geochemical complexity for permanent sequestration of CO{sub 2} as carbonates and is also relatively abundant. The effect of including NH{sub 3} in the injected gas stream was also investigated in this study. Precipitation of calcite and trace amounts of ammonium zeolites was observed. A batch geochemical model was developed using Geochemists Workbench (GWB). Degassing effect in the experiments was corrected using the sliding fugacity model in GWB. Experimental and simulation results were compared and a reasonable agreement between the two was observed.

  19. Thermal Energy Storage

    SciTech Connect (OSTI)

    Rutberg, Michael; Hastbacka, Mildred; Cooperman, Alissa; Bouza, Antonio

    2013-06-05

    The article discusses thermal energy storage technologies. This article addresses benefits of TES at both the building site and the electricity generation source. The energy savings and market potential of thermal energy store are reviewed as well.

  20. Hydrocarbons Heterogeneous Pyrolysis: Experiments and Modeling for Scramjet Thermal Management

    E-Print Network [OSTI]

    Bouchez, Marc; Visez, Nicolas; Herbinet, Olivier; Fournet, René; Marquaire, Paul-Marie

    2009-01-01

    The last years saw a renewal of interest for hypersonic research in general and regenerative cooling specifically, with a large increase of the number of dedicated facilities and technical studies. In order to quantify the heat transfer in the cooled structures and the composition of the cracked fuel entering the combustor, an accurate model of the thermal decomposition of the fuel is required. This model should be able to predict the fuel chemical composition and physical properties for a broad range of pressures, temperatures and cooling geometries. For this purpose, an experimental and modeling study of the thermal decomposition of generic molecules (long-chain or polycyclic alkanes) that could be good surrogates of real fuels, has been started at the DCPR laboratory located in Nancy (France). This successful effort leads to several versions of a complete kinetic model. These models do not assume any effect from the material that constitutes the cooling channel. A specific experimental study was performed ...

  1. Mechanism of Irradiation Assisted Cracking of Core Components in Light Water Reactors

    SciTech Connect (OSTI)

    Gary S. Was; Michael Atzmon; Lumin Wang

    2003-04-28

    The overall goal of the project is to determine the mechanism of irradiation assisted stress corrosion cracking (IASCC). IASCC has been linked to hardening, microstructural and microchemical changes during irradiation. Unfortunately, all of these changes occur simultaneously and at similar rates during irradiation, making attribution of IASCC to any one of these features nearly impossible to determine. The strategy set forth in this project is to develop means to separate microstructural from microchemical changes to evaluate each separately for their effect on IASCC. In the first part, post irradiation annealing (PIA) treatments are used to anneal the irradiated microstructure, leaving only radiation induced segregation (RIS) for evaluation for its contribution to IASCC. The second part of the strategy is to use low temperature irradiation to produce a radiation damage dislocation loop microstructure without radiation induced segregation in order to evaluate the effect of the dislocation microstructure alone. A radiation annealing model was developed based on the elimination of dislocation loops by vacancy absorption. Results showed that there were indeed, time-temperature annealing combinations that leave the radiation induced segregation profile largely unaltered while the dislocation microstructure is significantly reduced. Proton irradiation of 304 stainless steel irradiated with 3.2 MeV protons to 1.0 or 2.5 dpa resulted in grain boundary depletion of chromium and enrichment of nickel and a radiation damaged microstructure. Post irradiation annealing at temperatures of 500 ? 600°C for times of up to 45 min. removed the dislocation microstructure to a greater degree with increasing temperatures, or times at temperature, while leaving the radiation induced segregation profile relatively unaltered. Constant extension rate tensile (CERT) experiments in 288°C water containing 2 ppm O2 and with a conductivity of 0.2 mS/cm and at a strain rate of 3 x 10-7 s-1 showed that the IASCC susceptibility, as measured by the crack length per unit strain, decreased with very short anneals and was almost completely removed by an anneal at 500°C for 45 min. This annealing treatment removed about 15% of the dislocation microstructure and the irradiation hardening, but did not affect the grain boundary chromium depletion or nickel segregation, nor did it affect the grain boundary content of other minor impurities. These results indicate that RIS is not the sole controlling feature of IASCC in irradiated stainless steels in normal water chemistry. The isolation of the irradiated microstructure was approached using low temperature irradiation or combinations of low and high temperature irradiations to achieve a stable, irradiated microstructure without RIS. Experiments were successful in achieving a high degree of irradiation hardening without any evidence of RIS of either major or minor elements. The low temperature irradiations to doses up to 0.3 dpa at T<75°C were also very successful in producing hardening to levels considerably above that for irradiations conducted under nominal conditions of 1 dpa at 360°C. However, the microstructure consisted of an extremely fine dispersion of defect clusters of sizes that are not resolvable by either transmission electron microscopy (TEM) or small angle x-ray scattering (SAXS). The microstructure was not stable at the 288°C IASCC test temperature and resulted in rapid reduction of hardening and presumably, annealing of the defect clusters at this temperature as well. Nevertheless, the annealing studies showed that treatments that resulted in significant decreases in the hardening produced small changes in the dislocation microstructure that were confined to the elimination of the finest of loops (~1 nm). These results substantiate the importance of the very fine defect microstructure in the IASCC process. The results of this program provide the first definitive evidence that RIS is not the sole controlling factor in the irradiation assisted stress corrosion cracking of austenitic stain

  2. Thermal Management of Solar Cells

    E-Print Network [OSTI]

    Saadah, Mohammed Ahmed

    2013-01-01

    phonon transmission and interface thermal conductance acrossF. Miao, et al. , "Superior Thermal Conductivity of Single-Advanced Materials for Thermal Management of Electronic

  3. AQUIFER THERMAL ENERGY STORAGE

    E-Print Network [OSTI]

    Tsang, C.-F.

    2011-01-01

    time-varying solar energy inputs and thermal or powerthermal energy becomes apparent with the development of solar

  4. Crack initiation in smooth fatigue specimens of austenitic stainless steel in light water reactor environments.

    SciTech Connect (OSTI)

    Chopra, O. K.; Smith, J. L.

    1999-04-08

    The fatigue design curves for structural materials specified in Section III of the ASME Boiler and Pressure Vessel Code are based on tests of smooth polished specimens at room temperature in air. The effects of light water reactor (LWR) coolant environments are not explicitly addressed by the Code design curves; however, recent test data illustrate the detrimental effects of LWR coolant environments on the fatigue resistance of austenitic stainless steels (SSs). Certain loading and environmental conditions have led to test specimen fatigue lives that are significantly shorter than those obtained in air. Results of fatigue tests that examine the influence of reactor environments on crack initiation and crack growth of austenitic SSs are presented. Block loading was used to mark the fracture surface to determine crack length as a function of fatigue cycles in water environments, Crack lengths were measured by scanning electron microscopy. The mechanism for decreased fatigue life in LWR environments is discussed, and crack growth rates in the smooth fatigue specimens are compared with existing data from studies of crack growth rates.

  5. Stress-corrosion fatigue-crack growth in a Zr-based bulk amorphousmetal

    SciTech Connect (OSTI)

    Schroeder, V.; Ritchie, R.O.

    2005-09-21

    Electrochemical and mechanical experiments were conducted to analyze the environmentally-influenced cracking behavior of a bulk amorphous metal, Zr41.2Ti13.8Cu12.5Ni10Be22.5. This study was motivated by a scientific interest in mechanisms of fatigue-crack propagation in an amorphous metal, and by a practical interest in the use of this amorphous metal in applications that take advantage of its unique properties, including high specific strength, large elastic strains and low damping. The objective of the work was to determine the rate and mechanisms of subcritical crack growth in this metallic glass in an aggressive environment. Specifically, fatigue-crack propagation behavior was investigated at a range of stress intensities in air and aqueous salt solutions by examining the effects of loading cycle, stress-intensity range, solution concentration, anion identity, solution de-aeration, and bulk electrochemical potential. Results indicate that crack growth in aqueous solution in this alloy is driven by a stress-assisted anodic reaction at the crack tip. Rate-determining steps for such behavior are reasoned to be electrochemical, stress-dependent reaction at near-threshold levels, and mass transport at higher (steady-state) growth rates.

  6. Sonic IR crack detection of aircraft turbine engine blades with multi-frequency ultrasound excitations

    SciTech Connect (OSTI)

    Zhang, Ding; Han, Xiaoyan; Newaz, Golam

    2014-02-18

    Effectively and accurately detecting cracks or defects in critical engine components, such as turbine engine blades, is very important for aircraft safety. Sonic Infrared (IR) Imaging is such a technology with great potential for these applications. This technology combines ultrasound excitation and IR imaging to identify cracks and flaws in targets. In general, failure of engine components, such as blades, begins with tiny cracks. Since the attenuation of the ultrasound wave propagation in turbine engine blades is small, the efficiency of crack detection in turbine engine blades can be quite high. The authors at Wayne State University have been developing the technology as a reliable tool for the future field use in aircraft engines and engine parts. One part of the development is to use finite element modeling to assist our understanding of effects of different parameters on crack heating while experimentally hard to achieve. The development has been focused with single frequency ultrasound excitation and some results have been presented in a previous conference. We are currently working on multi-frequency excitation models. The study will provide results and insights of the efficiency of different frequency excitation sources to foster the development of the technology for crack detection in aircraft engine components.

  7. Placement of Thermal Vias in 3D ICs using Various Thermal Objectives

    E-Print Network [OSTI]

    Sapatnekar, Sachin

    via islands increased, more heat removal was achieved but less space was available for routing [3]. Li and greater thermal resistance along heat dissipation paths. With the advent of better processing technologies

  8. Multiwavelength Thermal Emission

    E-Print Network [OSTI]

    California at Santa Cruz, University of

    Multiwavelength Astronomy NASA #12;Thermal Emission #12;Thermal Emission Non-thermal p-p collisions Optical IR Radio/ Microwave sources of emission massive stars, WHIM, Ly many dust, cool objects-ray ~GeV Gamma-ray ~TeV sources of emission AGN, clusters, SNR, binaries, stars AGN (obscured), shocks

  9. Thermal neutron detection system

    DOE Patents [OSTI]

    Peurrung, Anthony J. (Richland, WA); Stromswold, David C. (West Richland, WA)

    2000-01-01

    According to the present invention, a system for measuring a thermal neutron emission from a neutron source, has a reflector/moderator proximate the neutron source that reflects and moderates neutrons from the neutron source. The reflector/moderator further directs thermal neutrons toward an unmoderated thermal neutron detector.

  10. Thermal Performance Benchmarking (Presentation)

    SciTech Connect (OSTI)

    Moreno, G.

    2014-11-01

    This project will benchmark the thermal characteristics of automotive power electronics and electric motor thermal management systems. Recent vehicle systems will be benchmarked to establish baseline metrics, evaluate advantages and disadvantages of different thermal management systems, and identify areas of improvement to advance the state-of-the-art.

  11. Compliant alkali silicate sealing glass for solid oxide fuel cell applications: Combined stability in isothermal ageing and thermal cycling with YSZ coated ferritic stainless steels

    SciTech Connect (OSTI)

    Chou, Y. S.; Thomsen, Edwin C.; Choi, Jung-Pyung; Stevenson, Jeffry W.

    2012-01-01

    An alkali-containing silicate glass (SCN-1) is currently being evaluated as a candidate sealing glass for solid oxide fuel cell (SOFC) applications. The glass contains about 17 mole% alkalis (K+Na) and has low glass transition and softening temperatures. It remains vitreous and compliant around 750-800oC after sealing without substantial crystallization, as contrary to conventional glass-ceramic sealants, which experience rapid crystallization after the sealing process. The glassy nature and low characteristic temperatures can reduce residual stresses and result in the potential for crack healing. In a previous study, the glass was found to have good thermal cycle stability and was chemically compatible with YSZ coating during short term testing. In the current study, the compliant glass was further evaluated in a more realistic way in that the sealed glass couples were first isothermally aged for 1000h followed by thermal cycling. High temperature leakage was measured. The chemical compatibility was also investigated with powder mixtures at 700 and 800oC to enhance potential interfacial reaction. In addition, interfacial microstructure was examined with scanning electron microscopy and evaluated with regard to the leakage and chemical compatibility results.

  12. Solid oxide fuel cell processing using plasma arc spray deposition techniques. Final report

    SciTech Connect (OSTI)

    Ray, E.R.; Spengler, C.J.; Herman, H.

    1991-07-01

    The Westinghouse Electric Corporation, in conjunction with the Thermal Spray Laboratory of the State University of New York, Stony Brook, investigated the fabrication of a gas-tight interconnect layer on a tubular solid oxide fuel cell with plasma arc spray deposition. The principal objective was to determine the process variables for the plasma spray deposition of an interconnect with adequate electrical conductivity and other desired properties. Plasma arc spray deposition is a process where the coating material in powder form is heated to or above its melting temperature, while being accelerated by a carrier gas stream through a high power electric arc. The molten powder particles are directed at the substrate, and on impact, form a coating consisting of many layers of overlapping, thin, lenticular particles or splats. The variables investigated were gun power, spray distance, powder feed rate, plasma gas flow rates, number of gun passes, powder size distribution, injection angle of powder into the plasma plume, vacuum or atmospheric plasma spraying, and substrate heating. Typically, coatings produced by both systems showed bands of lanthanum rich material and cracking with the coating. Preheating the substrate reduced but did not eliminate internal coating cracking. A uniformly thick, dense, adherent interconnect of the desired chemistry was finally achieved with sufficient gas- tightness to allow fabrication of cells and samples for measurement of physical and electrical properties. A cell was tested successfully at 1000{degree}C for over 1,000 hours demonstrating the mechanical, electrical, and chemical stability of a plasma-arc sprayed interconnect layer.

  13. Solid oxide fuel cell processing using plasma arc spray deposition techniques

    SciTech Connect (OSTI)

    Ray, E.R.; Spengler, C.J.; Herman, H.

    1991-07-01

    The Westinghouse Electric Corporation, in conjunction with the Thermal Spray Laboratory of the State University of New York, Stony Brook, investigated the fabrication of a gas-tight interconnect layer on a tubular solid oxide fuel cell with plasma arc spray deposition. The principal objective was to determine the process variables for the plasma spray deposition of an interconnect with adequate electrical conductivity and other desired properties. Plasma arc spray deposition is a process where the coating material in powder form is heated to or above its melting temperature, while being accelerated by a carrier gas stream through a high power electric arc. The molten powder particles are directed at the substrate, and on impact, form a coating consisting of many layers of overlapping, thin, lenticular particles or splats. The variables investigated were gun power, spray distance, powder feed rate, plasma gas flow rates, number of gun passes, powder size distribution, injection angle of powder into the plasma plume, vacuum or atmospheric plasma spraying, and substrate heating. Typically, coatings produced by both systems showed bands of lanthanum rich material and cracking with the coating. Preheating the substrate reduced but did not eliminate internal coating cracking. A uniformly thick, dense, adherent interconnect of the desired chemistry was finally achieved with sufficient gas- tightness to allow fabrication of cells and samples for measurement of physical and electrical properties. A cell was tested successfully at 1000{degree}C for over 1,000 hours demonstrating the mechanical, electrical, and chemical stability of a plasma-arc sprayed interconnect layer.

  14. Thermal conductivity measurements of Summit polycrystalline silicon.

    SciTech Connect (OSTI)

    Clemens, Rebecca; Kuppers, Jaron D.; Phinney, Leslie Mary

    2006-11-01

    A capability for measuring the thermal conductivity of microelectromechanical systems (MEMS) materials using a steady state resistance technique was developed and used to measure the thermal conductivities of SUMMiT{trademark} V layers. Thermal conductivities were measured over two temperature ranges: 100K to 350K and 293K to 575K in order to generate two data sets. The steady state resistance technique uses surface micromachined bridge structures fabricated using the standard SUMMiT fabrication process. Electrical resistance and resistivity data are reported for poly1-poly2 laminate, poly2, poly3, and poly4 polysilicon structural layers in the SUMMiT process from 83K to 575K. Thermal conductivity measurements for these polysilicon layers demonstrate for the first time that the thermal conductivity is a function of the particular SUMMiT layer. Also, the poly2 layer has a different variation in thermal conductivity as the temperature is decreased than the poly1-poly2 laminate, poly3, and poly4 layers. As the temperature increases above room temperature, the difference in thermal conductivity between the layers decreases.

  15. Computational modeling of crack initiation in cross-role piercing

    E-Print Network [OSTI]

    Chiluveru, Sudhir

    2007-01-01

    Thle Mannesmann process is the preferred method in the oil industry for fabrication of hollow pipes. The critical phenomenon in this process is the formation of a small round hole at the center of the cylindrical billet ...

  16. Ceramic Processing

    SciTech Connect (OSTI)

    EWSUK,KEVIN G.

    1999-11-24

    Ceramics represent a unique class of materials that are distinguished from common metals and plastics by their: (1) high hardness, stiffness, and good wear properties (i.e., abrasion resistance); (2) ability to withstand high temperatures (i.e., refractoriness); (3) chemical durability; and (4) electrical properties that allow them to be electrical insulators, semiconductors, or ionic conductors. Ceramics can be broken down into two general categories, traditional and advanced ceramics. Traditional ceramics include common household products such as clay pots, tiles, pipe, and bricks, porcelain china, sinks, and electrical insulators, and thermally insulating refractory bricks for ovens and fireplaces. Advanced ceramics, also referred to as ''high-tech'' ceramics, include products such as spark plug bodies, piston rings, catalyst supports, and water pump seals for automobiles, thermally insulating tiles for the space shuttle, sodium vapor lamp tubes in streetlights, and the capacitors, resistors, transducers, and varistors in the solid-state electronics we use daily. The major differences between traditional and advanced ceramics are in the processing tolerances and cost. Traditional ceramics are manufactured with inexpensive raw materials, are relatively tolerant of minor process deviations, and are relatively inexpensive. Advanced ceramics are typically made with more refined raw materials and processing to optimize a given property or combination of properties (e.g., mechanical, electrical, dielectric, optical, thermal, physical, and/or magnetic) for a given application. Advanced ceramics generally have improved performance and reliability over traditional ceramics, but are typically more expensive. Additionally, advanced ceramics are typically more sensitive to the chemical and physical defects present in the starting raw materials, or those that are introduced during manufacturing.

  17. Cracking of n-butane catalyzed by iron- and maganese-promoted sulfated zirconia

    SciTech Connect (OSTI)

    Cheung, T.K.; d`Itri, J.L.; Gates, B.C.

    1995-05-01

    Fe- and Mn-promoted sulfated zirconia was used to catalyze the conversion of n-butane at atmospheric pressure and n-butane partial pressures in the range of 0.0025-0.01 atm. At temperatures <225{degrees}C, the significant reactions were isomerization and disproportionation; in the range of 225-300{degrees}C, these reactions were accompanied by cracking, and at temperatures >350{degrees}C, cracking and isomerization occurred. Catalyst deactivation, resulting at least in part from coke formation, was rapid. The primary cracking products were methane, ethane, ethylene, and propylene. The observation of these products along with an ethane/ethylene molar ratio of nearly 1 at 450{degrees}C is consistent with cracking occurring, at least in part, by the Haag-Dessau mechanism, whereby the strongly acidic catalyst protonates n-butane to give carbonium ions. The rate of methane formation from n-butane cracking catalyzed by Fe- and Mn-promoted sulfated zirconia at 450{degrees}C was about 3 x 10{sup {minus}9}mol/(g of catalyst {center_dot}s). This comparison suggests that the catalytic activity of the promoted sulfated zirconia at 450{degrees}C is about the same as that of the zeolite, although its activity for n-butane isomerization and disproportionation at temperatures <100{degrees}C is orders of magnitude greater than those of zeolites. Thus the indication of superacidity of the promoted sulfated zirconia does not extend to high temperatures. The results raise questions about the nature of the presumed superacidity: perhaps the low-temperature reactions may involve catalyst functions other than the acidic function responsible for high-temperature cracking reactions or perhaps superacidic sites may be very rapidly poisoned at cracking temperatures. 14 refs., 8 figs., 3 tabs.

  18. Enhanced Productivity of Chemical Processes Using Dense Fluidized Beds

    SciTech Connect (OSTI)

    Sibashis Banerjee; Alvin Chen; Rutton Patel; Dale Snider; Ken Williams; Timothy O'Hern; Paul Tortora

    2008-02-29

    The work detailed in this report addresses Enabling Technologies within Computational Technology by integrating a “breakthrough” particle-fluid computational technology into traditional Process Science and Engineering Technology. The work completed under this DOE project addresses five major development areas 1) gas chemistry in dense fluidized beds 2) thermal cracking of liquid film on solids producing gas products 3) liquid injection in a fluidized bed with particle-to-particle liquid film transport 4) solid-gas chemistry and 5) first level validation of models. Because of the nature of the research using tightly coupled solids and fluid phases with a Lagrangian description of the solids and continuum description of fluid, the work provides ground-breaking advances in reactor prediction capability. This capability has been tested against experimental data where available. The commercial product arising out of this work is called Barracuda and is suitable for a wide (dense-to-dilute) range of industrial scale gas-solid flows with and without reactions. Commercial applications include dense gas-solid beds, gasifiers, riser reactors and cyclones.

  19. Thermally Activated Martensite: Its Relationship to Non-Thermally Activated (Athermal) Martensite

    SciTech Connect (OSTI)

    Laughlin, D E; Jones, N J; Schwartz, A J; Massalski, T B

    2008-10-21

    The classification of martensitic displacive transformations into athermal, isothermal or anisothermal is discussed. Athermal does not mean 'no temperature dependence' as is often thought, but is best considered to be short for the notion of no thermal activation. Processes with no thermal activation do not depend on time, as there is no need to wait for sufficient statistical fluctuations in some specific order parameter to overcome an activation barrier to initiate the process. Clearly, this kind of process contrasts with those that are thermally activated. In the literature, thermally activated martensites are usually termed isothermal martensites, suggesting a constant temperature. Actually such martensites also typically occur with continuous cooling. The important distinctive feature of these martensites is that they are thermally activated and hence are distinguishable in principle from athermal martensites. A third type of process, anisothermal, has been introduced to account for those transformations which are thought to be thermally activated but which occur on continuous cooling. They may occur so rapidly that they do not appear to have an incubation time, and hence could be mistakenly called an athermal transformation. These designations will be reviewed and discussed in terms of activation energies and kinetic processes of the various martensitic transformations.

  20. The effect of residuals on the presence of intergranular surface cracks on continuously cast billets

    SciTech Connect (OSTI)

    Wijngaarden, M.J.U.T. van; Visagie, G.P.

    1996-12-31

    During 1991, Iscor Vereeniging experienced a dramatic increase in the rejection rate of specialty steel bars rolled from continuously cast billets due to the presence of seams on the bars. The seams originated from tearing of the billets during the first 2 passes in the roughing mill during hot rolling. The defective billets were found to contain fine intergranular cracks on the surface. Such cracks have been described in the literature and have been attributed to the presence of high levels of residuals resulting in the well-known phenomenon of surface hot shortness which results from the enrichment of residuals at the grain boundaries after preferential oxidation of iron during scaling of the steel. The present investigation revealed that the effect of residuals on intergranular surface cracking is a complex interaction between steel composition and casting conditions such as casting speed, intensity of secondary cooling, section size, and mold type. This paper quantifies the effect of residuals on the intergranular surface cracking of continuously cast billets and quantitatively relates the incidence of these cracks to parameters which can be controlled during steelmaking and continuous casting.

  1. Cracking of simulated oil refinery off-gas over a coal char, petroleum coke, and quartz

    SciTech Connect (OSTI)

    Yuan Zhang; Jin-hu Wu; Dong-ke Zhang

    2008-03-15

    The cracking of oil refinery off-gas, simulated with a gas mixture containing methane (51%), ethylene (21.4%), ethane (21.1%), and propane (6.5%), over a coal char, petroleum coke, and quartz, respectively, has been studied in a fixed bed reactor. The experiments were performed at temperatures between 850 and 1000{sup o}C and at atmospheric pressure. The results show that the conversions of all species considered increased with increasing temperature. Ethane and propane completely decomposed over all three bed materials in the temperature range investigated. However, the higher initial conversion rates of methane and ethylene cracking at all temperatures were observed only over the coal char and not on the petroleum coke and quartz, indicating a significant catalytic effect of the coal char on methane and ethylene cracking. Methane and ethylene conversions decreased with reaction time due to deactivation of the coal char by carbon deposition on the char surface and, in the later stage of a cracking experiment, became negative, suggesting that methane and ethylene had been formed during the cracking of ethane and propane. 16 refs., 13 figs., 2 tabs.

  2. Detection of submicron scale cracks and other surface anomalies using positron emission tomography

    DOE Patents [OSTI]

    Cowan, Thomas E.; Howell, Richard H.; Colmenares, Carlos A.

    2004-02-17

    Detection of submicron scale cracks and other mechanical and chemical surface anomalies using PET. This surface technique has sufficient sensitivity to detect single voids or pits of sub-millimeter size and single cracks or fissures of millimeter size; and single cracks or fissures of millimeter-scale length, micrometer-scale depth, and nanometer-scale length, micrometer-scale depth, and nanometer-scale width. This technique can also be applied to detect surface regions of differing chemical reactivity. It may be utilized in a scanning or survey mode to simultaneously detect such mechanical or chemical features over large interior or exterior surface areas of parts as large as about 50 cm in diameter. The technique involves exposing a surface to short-lived radioactive gas for a time period, removing the excess gas to leave a partial monolayer, determining the location and shape of the cracks, voids, porous regions, etc., and calculating the width, depth, and length thereof. Detection of 0.01 mm deep cracks using a 3 mm detector resolution has been accomplished using this technique.

  3. Fracture toughness results and preliminary analysis for International Cooperative Test Program on specimens containing surface cracks

    SciTech Connect (OSTI)

    Reuter, W.G.; Elfer, N.C.; Hull, D.A.; Newman, J.C. Jr.; Munz, D.; Panontin, T.L.

    1997-12-31

    Specimens containing surface cracks were tested in either tension or bending to compare the stress intensity factor at failure with plane strain fracture toughness (K{sub Ic}) in an International Cooperative Test Program. The material was heat treated to {sigma}{sub ys} = 1 587 MPa and K{sub Ic} = 54 MPa m{sub 1/2}. Because substantial stable crack growth occurred for some specimens, the test plan was modified to include detecting the onset of crack growth. It is shown that P{sub max} and the original fatigue precrack size cannot be employed to calculate K{sub max} for comparison with K{sub Ic} when significant stable crack growth occurs. However, using P{sub init} (load at which stable crack growth is initiated) and the original fatigue precrack size to calculate K{sub max} or K{sub {phi}=30{degree}} provides a very useful comparison with K{sub Ic}. The influence of variations in fatigue precrack configuration on test results are also discussed.

  4. Acoustic Emission and Guided Wave Monitoring of Fatigue Crack Growth on a Full Pipe Specimen

    SciTech Connect (OSTI)

    Meyer, Ryan M.; Cumblidge, Stephen E.; Ramuhalli, Pradeep; Watson, Bruce E.; Doctor, Steven R.; Bond, Leonard J.

    2011-05-06

    Continuous on-line monitoring of active and passive systems, structures and components in nuclear power plants will be critical to extending the lifetimes of nuclear power plants in the US beyond 60 years. Acoustic emission and guided ultrasonic waves are two tools for continuously monitoring passive systems, structures and components within nuclear power plants and are the focus of this study. These tools are used to monitor fatigue damage induced in a SA 312 TP304 stainless steel pipe specimen. The results of acoustic emission monitoring indicate that crack propagation signals were not directly detected. However, acoustic emission monitoring exposed crack formation prior to visual confirmation through the detection of signals caused by crack closure friction. The results of guided ultrasonic wave monitoring indicate that this technology is sensitive to the presence and size of cracks. The sensitivity and complexity of GUW signals is observed to vary with respect to signal frequency and path traveled by the guided ultrasonic wave relative to the crack orientation.

  5. Fracture behavior of ceramic laminates in bending-I. Modeling of crack propagation

    SciTech Connect (OSTI)

    Phillipps, A.J.; Clegg, W.J.; Clyne, T.W. . Dept. of Materials Science and Metallurgy)

    1993-03-01

    This paper concerns the fracture behavior of specimens made up of ceramic sheets, separated by thin interlayers, which act to deflect cracks and thus to prevent catastrophic failure of the specimen. The treatment is divided into two parts. In this paper, the behavior of this type of material during bending is quantitatively modeled. The model is based on through-thickness cracks propagating when a critical stress is reached and interfacial cracks then advancing a distance dictated by the available energy. The variation in laminae strengths is modeled using a Monte Carlo method to determine the strength of successive laminae for a given Weibull modulus. The model is used to predict load/displacement plots and to explore the effects of changes in loading geometry and specimen variables, including Young's modulus, lamina strength, loading span, interfacial toughness, as well as lamina and sample thickness. A distinction is drawn between the energy actually absorbed in causing complete failure of the specimen as measured from the area under the load/displacement curve, and the amount of energy necessary to cause the crack propagation which occurred. These differ if the energy available to drive the interfacial cracks is more than sufficient for them to reach the ends of the specimen or if energy is dissipated elsewhere in the system. A criterion is derived by which specimens can be designed so as to minimize the difference between these two quantities. The significance of this concept in optimizing the toughness of these laminated materials is briefly discussed.

  6. Catalytic thermal barrier coatings

    DOE Patents [OSTI]

    Kulkarni, Anand A. (Orlando, FL); Campbell, Christian X. (Orlando, FL); Subramanian, Ramesh (Oviedo, FL)

    2009-06-02

    A catalyst element (30) for high temperature applications such as a gas turbine engine. The catalyst element includes a metal substrate such as a tube (32) having a layer of ceramic thermal barrier coating material (34) disposed on the substrate for thermally insulating the metal substrate from a high temperature fuel/air mixture. The ceramic thermal barrier coating material is formed of a crystal structure populated with base elements but with selected sites of the crystal structure being populated by substitute ions selected to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a higher rate than would the base compound without the ionic substitutions. Precious metal crystallites may be disposed within the crystal structure to allow the ceramic thermal barrier coating material to catalytically react the fuel-air mixture at a lower light-off temperature than would the ceramic thermal barrier coating material without the precious metal crystallites.

  7. Hydroprocessing catalyst and process

    SciTech Connect (OSTI)

    Chen, N.Y.; Huang, T.J.

    1988-07-12

    In a hydrocracking process for converting a hydrocarbon feed, at least 70% of which boils within the range of 650/sup 0/ to about 1050/sup 0/F, to liquid products boiling in the rane of C/sub 5/+ to 700/sup 0/F. This patent describes a process which comprises contacting the feed and gaseous hydrogen at elevated pressure with a hydrocracking catalyst under hydrocracking conditions. The improvement comprises: contacting the feed with a hydrocracking catalyst composition comprising a hydrogenation component, a crystalline aluminosilicate cracking component having the essential X-ray diffraction pattern of Zeolite Beta, the crystalline aluminosilicate being further characterized by the presence of 0.5 wt % to about 4.0 wt % of framework boron and a silica to alumina ratio of at least about 35, and a solid source of alumina, whereby the catalyst life is extended.

  8. Characterization of geothermal reservoir crack patterns using shear-wave

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION J APPENDIX ECoopButte County,Camilla,Thermal Gradient HolesCentral,Chandler HillsOpensplitting |

  9. AQUIFER THERMAL ENERGY STORAGE

    E-Print Network [OSTI]

    Tsang, C.-F.

    2011-01-01

    aquifers for thermal energy storage. Problems outlined abovean Aquifer Used for Hot Water Storage: Digital Simulation ofof Aquifer Systems for Cyclic Storage of Water," of the Fall

  10. Scattering Solar Thermal Concentrators

    Office of Environmental Management (EM)

    sunshot DOEGO-102012-3669 * September 2012 MOTIVATION All thermal concentrating solar power (CSP) systems use solar tracking, which involves moving large mirror surfaces...

  11. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    pp. 67-73, 2003. [17] "Energy Requirements of Desalinationof solar collectors and thermal energy storage in solarapplications," Applied Energy, pp. 538-553, 2013. [20] P. G.

  12. Solar Thermal Powered Evaporators

    E-Print Network [OSTI]

    Moe, Christian Robert

    2015-01-01

    C. Y. Zhao, "A review of solar collectors and thermal energya Passive Flat-Plate Solar Collector," International Journalof Flat Plate Solar Collector Equipped with Rectangular Cell

  13. Method for cracking hydrocarbon compositions using a submerged reactive plasma system

    DOE Patents [OSTI]

    Kong, P.C.

    1997-05-06

    A method is described for cracking a liquid hydrocarbon composition (e.g. crude oil) to produce a cracked hydrocarbon product. A liquid hydrocarbon composition is initially provided. An electrical arc is generated directly within the hydrocarbon composition so that the arc is entirely submerged in the composition. Arc generation is preferably accomplished using a primary and secondary electrode each having a first end submerged in the composition. The first ends of the electrodes are separated from each other to form a gap there between. An electrical potential is then applied to the electrodes to generate the arc within the gap. A reactive gas is thereafter delivered to the arc which forms a bubble around the arc. Gas delivery may be accomplished by providing a passageway through each electrode and delivering the gas through the passageways. The arc and gas cooperate to produce a plasma which efficiently cracks the hydrocarbon composition. 6 figs.

  14. Ultrasonic inspection of austenitic stainless steel welds with artificially produced stress corrosion cracks

    SciTech Connect (OSTI)

    Dugan, Sandra; Wagner, Sabine [Materials Testing Institute University of Stuttgart (MPA), Pfaffenwaldring 32, 70569 Stuttgart (Germany)

    2014-02-18

    Austenitic stainless steel welds and nickel alloy welds, which are widely used in nuclear power plants, present major challenges for ultrasonic inspection due to the grain structure in the weld. Large grains in combination with the elastic anisotropy of the material lead to increased scattering and affect sound wave propagation in the weld. This results in a reduced signal-to-noise ratio, and complicates the interpretation of signals and the localization of defects. Mechanized ultrasonic inspection was applied to study austenitic stainless steel test blocks with different types of flaws, including inter-granular stress corrosion cracks (IGSCC). The results show that cracks located in the heat affected zone of the weld are easily detected when inspection from both sides of the weld is possible. In cases of limited accessibility, when ultrasonic inspection can be carried out only from one side of a weld, it may be difficult to distinguish between signals from scattering in the weld and signals from cracks.

  15. Method for cracking hydrocarbon compositions using a submerged reactive plasma system

    DOE Patents [OSTI]

    Kong, Peter C. (Idaho Falls, ID)

    1997-01-01

    A method for cracking a liquid hydrocarbon composition (e.g. crude oil) to produce a cracked hydrocarbon product. A liquid hydrocarbon composition is initially provided. An electrical arc is generated directly within the hydrocarbon composition so that the arc is entirely submerged in the composition. Arc generation is preferably accomplished using a primary and secondary electrode each having a first end submerged in the composition. The first ends of the electrodes are separated from each other to form a gap therebetween. An electrical potential is then applied to the electrodes to generate the arc within the gap. A reactive gas is thereafter delivered to the arc which forms a bubble around the arc. Gas delivery may be accomplished by providing a passageway through each electrode and delivering the gas through the passageways. The arc and gas cooperate to produce a plasma which efficiently cracks the hydrocarbon composition.

  16. Can surface cracks and unipolar arcs explain breakdown and gradient limits?

    SciTech Connect (OSTI)

    Insepov, Zeke; Norem, Jim

    2013-01-15

    The authors argue that the physics of unipolar arcs and surface cracks can help understand rf breakdown and vacuum arc data. They outline a model of the basic mechanisms involved in breakdown and explore how the physics of unipolar arcs and cracks can simplify the picture of breakdown and gradient limits in accelerators, tokamaks as well as laser ablation, micrometeorites, and other applications. Cracks are commonly seen in SEM images of arc damage and they are produced as the liquid metal cools. They can produce the required field enhancements to explain field emission data and can produce mechanical failure of the surface that would trigger breakdown events. Unipolar arcs can produce currents sufficient to short out rf structures, and can cause the sort of damage seen in SEM images. They should be unstable, and possibly self-quenching, as seen in optical fluctuations and surface damage. The authors describe some details and consider the predictions of this simple model.

  17. Method and apparatus for detecting external cracks from within a metal tube

    DOE Patents [OSTI]

    Caffey, Thurlow W. H. (Albuquerque, NM)

    2001-08-07

    A method and tool using a continuous electromagnetic wave from a transverse magnetic-dipole source with a coaxial electric-dipole receiver is described for the detection of external sidewall cracks and other anomalies in boiler tubes and other enclosures. The invention utilizes the concept of radar backscatter rather than eddy-currents or ultrasound, which are sometimes used in prior art crack-detection methods. A numerical study of the distribution of the fields shows that the direct transmission from the source to the receiver is reduced from that in free space. Further, if the diameter of the receiver dipole is made sufficiently small, it should be possible to detect cracks with a scattering loss of up to -40 dB in thin-walled boiler tubes.

  18. Fast Thermal Simulation for Architecture Level Dynamic Thermal Management

    E-Print Network [OSTI]

    Tan, Sheldon X.-D.

    Fast Thermal Simulation for Architecture Level Dynamic Thermal Management Pu Liu, Zhenyu Qi, Hang temperature by dynamic thermal managements becomes necessary. This paper proposes a novel approach to the thermal analysis at chip architecture level for efficient dynamic thermal management. Our new approach

  19. Mechanisms for fracture and fatigue-crack propagation in a bulk metallic glass

    SciTech Connect (OSTI)

    Gilbert, C.J.; Schroeder, V.; Ritchie, R.O. [Univ. of California, Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering

    1999-07-01

    The fracture and fatigue properties of a newly developed bulk metallic glass alloy, Zr{sub 41.2}Ti{sub 13.8}Cu{sub 12.5}Ni{sub 10}Be{sub 22.5} (at. pct), have been examined. Experimental measurements using conventional fatigue precracked compact-tension C(T) specimens ({approximately}7-mm thick) indicated that the fully amorphous alloy has a plane-strain fracture toughness comparable to polycrystalline aluminum alloys. However, significant variability was observed and possible sources are identified. The fracture surfaces exhibited a vein morphology typical of metallic glasses, and, in some cases, evidence for local melting was observed. Attempts were made to rationalize the fracture toughness in terms of a previously developed micromechanical model based on the Taylor instability, as well as on the observation of extensive crack branching and deflection. Upon partial or complete crystallization, however, the alloy was severely embrittled, with toughnesses dropping to {approximately}1 MPa {radical}m. Commensurate with this drop in toughness was a marginal increase in hardness and a reduction in ductility (as measured via depth-sensing indentation experiments). Under cyclic loading, crack-propagation behavior in the amorphous structure was similar to that observed in polycrystalline steel and aluminum alloys. Moreover, the crack-advance mechanism was associated with alternating blunting and resharpening of the crack tip. This was evidenced by striations on fatigue fracture surfaces. Conversely, the (unnotched) stress/life (S/N) properties were markedly different. Crack initiation and subsequent growth occurred quite readily, due to the lack of microstructural barriers that would normally provide local crack-arrest points. This resulted in a low fatigue limit of {approximately}4 pct of ultimate tensile strength.

  20. On Axion Thermalization in the Early Universe

    E-Print Network [OSTI]

    Eduard Masso; Francesc Rota; Gabriel Zsembinszki

    2002-05-24

    We reanalyze the conditions under which we have a primordial thermal population of axions. Compared with previous studies, we find other processes, involving gluons and quarks, that dominate at high temperatures. We conclude that if the Peccei-Quinn scale fulfills $F_a < 1.2 \\times 10^{12} \\GeV$ there is thermal axion production. In this case, a period in the early universe exists where axions interact with the QCD plasma and we point out that non-thermal axions produced before the end of this period will thermalize. This could lead to a reduction of the expected density of axions from string decay in models with $F_a < 1.2 \\times 10^{12} \\GeV$.