National Library of Energy BETA

Sample records for thermal cracking process

  1. Process for the hydroformylation of sulfur-containing thermally cracked petroleum residue and novel products thereof

    SciTech Connect (OSTI)

    Oswald, A.A.; Bhatia, R.N.; Mozeleski, E.J.; Glivicky, A.P.; Brueggeman, B.G.; Hooten, J.R.; Smith, C.M.; Hsu, C.S.

    1991-07-09

    This patent describes a hydroformylation-hydrogenation process comprising reacting an olefinic cracked petroleum distillate feed, produced from petroleum residue by high temperature thermal cracking, and containing C{sub 5} to C{sub 35}-1-n-alkyl olefins as the major type of olefin components, and organic sulfur compounds in concentrations exceeding 0.1% sulfur. It comprises at first with carbon monoxide and hydrogen at temperatures between about 50 and 250{degrees} C and pressures in the range of 50 to 6000 psi; in the presence of a Group VIII transition metal carbonyl complex catalyst in effective amounts to produce aldehydes of a semilinear character having an average of less than one alkyl branch per molecule and 20% by weight or more linear isomers, then with molecular hydrogen at temperatures between 100 and 250{degrees} C and pressures between 200 psi and 5000 psi (13.6 and 340 atm) in the presence of a hydrogenation catalyst in effective amounts the catalyst being sulfur resistant cobalt, molybdenum, nickel, or tungsten or a sulfide thereof to produce the corresponding alcohols of a semilinear character having an average of less than one alkyl branch per molecule and 20% by weight or more linear isomers, then with molecular hydrogen at temperatures between 100 and 250{degrees} C and pressures between 200 psi and 5000 psi (13.6 and 340 atm) in the presence of a hydrogenation catalyst in effective amounts the catalyst being sulfur resistant cobalt, molybdenum, nickel, or tungsten or a sulfide thereof to produce the corresponding alcohols of a semilinear character having an average of less than one alkyl branch per molecule.

  2. Catalytic cracking process

    DOE Patents [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.

  3. Heavy oil catalytic cracking process and apparatus (Patent) ...

    Office of Scientific and Technical Information (OSTI)

    Heavy oil catalytic cracking process and apparatus Citation Details In-Document Search Title: Heavy oil catalytic cracking process and apparatus This paper describes a fluidized ...

  4. Ultrasonic Study of Crack Under a Dynamic Thermal Load

    SciTech Connect (OSTI)

    Pitkaenen, J.; Kemppainen, M.; Virkkunen, I.

    2004-02-26

    In piping the defects play a key role for determining the life of component. Also the risk for pipe failure combined to the defects has to be taken into account. In this study thermal dynamic load has been applied to austenitic material (AISI 304) in order to introduce dynamic behaviour into the crack. The studied crack ({approx}20 mm x 7 mm) has been produced by thermal fatigue in advance. Different ultrasonic techniques were used to reveal information from interaction of ultrasonic waves from dynamic behaviour of a crack face in the sonified volume. The ultrasonic probes in the study are typical probes for defect detection and sizing on site inspections This information helps us to understand some effects in nuclear piping such as detection of cracks with special techniques and difficulties in sizing of the cracks in real situations. In this case the material is loaded to exceed the yield strength. The thermal cycles used caused high variations in the temperature scale from 20 deg. C (68 F) to 600 deg. C (1112 F) in the crack volume especially on the crack surface area. These factors cause large stress variations in the vicinity of the crack. Effects which have been detected during analysis from the measurements explain well difficulties in ultrasonic inspections of those materials on site. Experimental work explains reasons why some defects are missed in the real piping. Ultrasonic techniques used are described in details and conclusion for applicability of those techniques has been drawn.

  5. 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.

  6. Process for magnetic beneficiating petroleum cracking catalyst

    DOE Patents [OSTI]

    Doctor, Richard D.

    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.

  7. Prevention of crack initiation in valve bodies under thermal shock

    SciTech Connect (OSTI)

    Delmas, J.; Coppolani, P.

    1996-12-01

    On site and testing experience has shown that cracking in valves affects mainly the stellite hardfacing on seats and discs but may also be a concern for valve bodies. Metallurgical investigations conducted by EDF laboratories on many damaged valves have shown that most of the damage had either a chemical, manufacturing, or operating origin with a strong correlation between the origins and the type of damage. The chemical defects were either excess ferritic dilution of stellite or excess carburizing. Excess carburizing leads to a too brittle hardfacing which cracks under excessive stresses induced on the seating surfaces, via the stem, by too high operating thrusts. The same conditions can also induce cracks of the seats in the presence, in the hardfacing, of hidden defects generated during the welding process. Reduction of the number of defects results first from controls during manufacturing, mainly in the thickness of stellite. On the other hand, maintenance must be fitted to the type of defect. In-situ lapping may lead to release of cobalt, resulting in contamination of the circuit. Furthermore, it is ineffectual in the case of a crack through the seating surface, as is often found on globe valves. The use of new technologies of valves with removable seats and cobalt-free alloys solves permanently this kind of problem.

  8. Process to minimize cracking of pyrolytic carbon coatings

    DOE Patents [OSTI]

    Lackey, Jr., Walter J.; Sease, John D.

    1978-01-01

    Carbon-coated microspheroids useful as fuels in nuclear reactors are produced with a low percentage of cracked coatings and are imparted increased strength and mechanical stability characteristics by annealing immediately after the carbon coating processes.

  9. Process for the detection of micro-cracks

    DOE Patents [OSTI]

    Lapinski, Norman; Sather, Allen

    1979-01-01

    A process for the nondestructive testing of ceramic objects to detect the presence of defects and micro-cracks in the surface in which a solution of silver nitrate is applied to the surface of the object which penetrates into the surface defects, drying the object so that the silver nitrate remains in the defects, and preparing an X-ray radiograph whereby any defects and micro-cracks will appear in the radiograph.

  10. Resid cracking process and apparatus (Patent) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    and the cracking catalyst is coked, catalyst is separated from cracked products in a separation means, coked catalyst is stripped of strippable hydrocarbons with a stripping gas, ...

  11. Process for catalytic cracking of heavy hydrocarbon feed to lighter products

    SciTech Connect (OSTI)

    Herbst, J.A.; Owen, H.; Schipper, P.H.

    1990-05-29

    This patent describes a process for catalytic cracking of a feed of hydrocarbons boiling in the gas oil and heavier boiling range to lighter products by contacting the feed at catalytic cracking conditions and catalytically cracking the feed to lighter products with a cracking catalyst. It comprises: a mixture of separate particles of: a bulk conversion cracking catalyst containing at least one component with an equivalent pore size of at least about 7 angstroms in a matrix, the bulk conversion cracking catalyst having fluidization properties which permit use in a fluidized or moving bed catalytic cracking reactor; a light paraffin upgrading catalyst comprising at least one zeolite having a constraint index of 1--12 and paraffin cracking/isomerization activity; and, a light paraffin upgrading catalyst comprising at least one zeolite having a constraint index of 1--12 and paraffin aromatization activity; and wherein the upgrading catalysts have substantially the same fluidization properties as the bulk conversion cracking catalyst.

  12. 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.

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

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

    Materials Selection Considerations for Thermal Process Equipment: A BestPractices Process Heating Technical Brief Materials Selection Considerations for Thermal Process Equipment: ...

  14. Heavy oil catalytic cracking process and apparatus (Patent) ...

    Office of Scientific and Technical Information (OSTI)

    Subject: 02 PETROLEUM; 42 ENGINEERING; 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; CATALYSTS; COOLING; PETROLEUM; CATALYTIC CRACKING; AIR POLLUTION CONTROL; COKE; ...

  15. Materials performance in prototype Thermal Cycling Absorption Process (TCAP) columns

    SciTech Connect (OSTI)

    Clark, E.A.

    1992-11-21

    Two prototype Thermal Cycling Absorption Process (TCAP) columns have been metallurgically examined after retirement, to determine the causes of failure and to evaluate the performance of the column container materials in this application. Leaking of the fluid heating and cooling subsystems caused retirement of both TCAP columns, not leaking of the main hydrogen-containing column. The aluminum block design TCAP column (ABL block TCAP) used in the Advanced Hydride Laboratory, Building 773-A, failed in one nitrogen inlet tube that was crimped during fabrication, which lead to fatigue crack growth in the tube and subsequent leaking of nitrogen from this tube. The Third Generation stainless steel design TCAP column (Third generation TCAP), operated in 773-A room C-061, failed in a braze joint between the freon heating and cooling tubes (made of copper) and the main stainless steel column. In both cases, stresses from thermal cycling and local constraint likely caused the nucleation and growth of fatigue cracks. No materials compatibility problems between palladium coated kieselguhr (the material contained in the TCAP column) and either aluminum or stainless steel column materials were observed. The aluminum-stainless steel transition junction appeared to be unaffected by service in the AHL block TCAP. Also, no evidence of cracking was observed in the AHL block TCAP in a location expected to experience the highest thermal shock fatigue in this design. It is important to limit thermal stresses caused by constraint in hydride systems designed to work by temperature variation, such as hydride storage beds and TCAP columns.

  16. Materials performance in prototype Thermal Cycling Absorption Process (TCAP) columns

    SciTech Connect (OSTI)

    Clark, E.A.

    1992-11-21

    Two prototype Thermal Cycling Absorption Process (TCAP) columns have been metallurgically examined after retirement, to determine the causes of failure and to evaluate the performance of the column container materials in this application. Leaking of the fluid heating and cooling subsystems caused retirement of both TCAP columns, not leaking of the main hydrogen-containing column. The aluminum block design TCAP column (AHL block TCAP) used in the Advanced Hydride Laboratory, Building 773-A, failed in one nitrogen inlet tube that was crimped during fabrication, which lead to fatigue crack growth in the tube and subsequent leaking of nitrogen from this tube. The Third Generation stainless steel design TCAP column (Third generation TCAP), operated in 773-A room C-061, failed in a braze joint between the freon heating and cooling tubes (made of copper) and the main stainless steel column. In both cases, stresses from thermal cycling and local constraint likely caused the nucleation and growth of fatigue cracks. No materials compatibility problems between palladium coated kieselguhr (the material contained in the TCAP column) and either aluminum or stainless steel column materials were observed. The aluminum-stainless steel transition junction appeared to be unaffected by service in the AHL block TCAP. Also, no evidence of cracking was observed in the AHL block TCAP in a location expected to experience the highest thermal shock fatigue in this design. It is important to limit thermal stresses caused by constraint in hydride systems designed to work by temperature variation, such as hydride storage beds and TCAP columns.

  17. VEBA-cracking-processes for upgrading heavy oils and refinery residues

    SciTech Connect (OSTI)

    Graeser, U.; Niemann, K.

    1983-03-01

    More than 20 different heavy oils and residues have been processed by the VEBA-Combi-Cracking and VEBA-LQ-Cracking high pressure hydrocracking processes, in a bench scale unit. Conversions up to 99 wt % of to a syncrude, consisting of naphtha middle distillate and vacuum gas oil were obtained. Conversions correlate with space velocity at a given temperature and product pattern depends upon degree of conversion. The VEBA-LQ-Cracking process produces a stable syncrude whereas the products of the VEBA-Combi process are very low in sulfur and nitrogen.

  18. Investigating coupled thermal-hydrological-mechanical processes...

    Office of Scientific and Technical Information (OSTI)

    processes in geothermal reservoirs Citation Details In-Document Search Title: Investigating coupled thermal-hydrological-mechanical processes in geothermal reservoirs ...

  19. The study of crack resistance of TiAlN coatings under mechanical loading and thermal cycle testing

    SciTech Connect (OSTI)

    Akulinkin, Alexandr Shugurov, Artur Sergeev, Viktor; Panin, Alexey; Cheng, C.-H.

    2015-10-27

    The effect of preliminary ion bombardment of 321 stainless steel substrate on crack resistance of TiAlN coatings at uniaxial tension and thermal cycling is studied. The ion-beam treatment of the substrate is shown to substantially improve the adhesion strength of the coatings that prevents their delamination and spalling under uniaxial tension. The resistance to crack propagation and spalling by the thermal shock is higher in the TiAlN coating deposited onto the substrate subjected to Ti ion bombardment as compared to that in the TiAlN coating deposited onto the initial substrate.

  20. Stress-corrosion crack initiation process for Alloy 182 weld metal in simulated BWR environments

    SciTech Connect (OSTI)

    Nakayama, Guen; Akashi, Masatsune

    1995-09-01

    For preventing SCC from occurring in the internal structure of materials of the BWR plant, the injection of hydrogen into the core-water so as to reduce the free corrosion potential of the materials were proposed. Because of the lack of basic data of stress-corrosion cracking susceptibility in BWR environment on Ni-based alloys in comparison with stainless steels, the slow strain-rate tensile (SSRT) tests and the creviced bent-beam (CBB) test were conducted for a sensitized Alloy 182 weld metal in high-purity water environments containing dissolved oxygen (DO) and hydrogen (DH) to varied concentrations at 288 C, and the SCC initiation process were examined. The susceptibility of a material to SCC was discussed in terms of the electrode potential effect, and the effects of impurities of the testing water were examined by adding slightly Na{sub 2}, SO{sub 4}. In high purity waters and in the electrode potential region higher than {minus} 0.2 V vs. SHE, the interdendritic stress-corrosion cracks were observed both in the slow strain-rate test and the creviced bent-beam test. SEM observations of sub-cracks at the specimen surfaces revealed that stress-corrosion cracks were initiated when the oxide film had cracked to under-hundred {micro}m wide, that no such individual cracks could grow per se, but that those micro-cracks which happened to be formed in each other`s vicinity would coalesce into large cracks, one of which made propagated as stress-corrosion cracking, and that the stress-corrosion cracking sensitivity became more acute on addition of impurity. In the electrode potential region lower than 0 V, on the other hand, the stress-corrosion cracks were observed to be initiated at bottoms of corrosion pits formed on the specimen surfaces in the former, whereas both type of stress-corrosion cracks were observed between 0 to {minus}0.2V. No stress-corrosion crack was observed even though much the same corrosion pits in the CBB test at {minus}0.4 V.

  1. Primary water stress corrosion cracking of Alloy 600: Effects of processing parameters

    SciTech Connect (OSTI)

    Seman, D.J.; Webb, G.L.; Parrington, R.J.

    1993-10-22

    Correlations of stress corrosion cracking (SCC) data in deaerated water with temperature, stress, metallography, and processing for laboratory test specimens are presented. Initiation time data show that a low temperature anneal and resulting absence of grain boundary carbides result in a material having increased susceptibility to SCC. Data also show that hot worked and annealed Alloy 600 is more resistant than cold worked and annealed material, both having carbide decorated grain boundaries. In absence of grain boundary carbides, both materials are equally susceptible. Low temperature thermal treatment (1100F) reduces SCC susceptibility with or without grain boundary decoration. Weld metal data and data correlations developed from 700 double U-bends are presented. Data demonstrate the effect of increased carbon content to improve SCC resistance. The data shows that the general relation of time, temperature and strain for wrought material is followed for the weld metal. The weld process used did not affect the SCC susceptibility of EN-82 which showed a greater resistance to SCC than EN-62. Stress relief of weld deposits showed an improvement for wrought material. Heat affected zone resistance was improved if the starting material received a high temperature anneal (1850 to 2000F). Range of SCC initiation times for weld metal is comparable to the range of initiation times for wrought material.

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

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

    Continuous Processing of High Thermal Conductivity Polyethylene Fibers and Sheets Massachusetts Institute of Technology (MIT) - Cambridge, MA A new, continuous manufacturing ...

  3. Thermally activated dislocation creep model for primary water stress corrosion cracking of NiCrFe alloys

    SciTech Connect (OSTI)

    Hall, M.M., Jr

    1995-12-31

    There is a growing awareness that awareness that environmentally assisted creep plays an important role in integranular stress corrosion cracking (IGSCC) of NiCrFe alloys in the primary coolant water environment of a pressurized water reactor (PWR). The expected creep mechanism is the thermally activated glide of dislocations. This mode of deformation is favored by the relatively low temperature of PWR operation combined with the large residual stresses that are most often identified as responsible for the SCC failure of plant components. Stress corrosion crack growth rate (CGR) equations that properly reflect the influence of this mechanism of crack tip deformation are required for accurate component life predictions. A phenomenological IGSCC-CGR model, which is based on an apriori assumption that the IGSCC-CGR is controlled by a low temperature dislocation creep mechanism, is developed in this report. Obstacles to dislocation creep include solute atoms such as carbon, which increase the lattice friction force, and forest dislocations, which can be introduced by cold prestrain. Dislocation creep also may be environmentally assisted due to hydrogen absorption at the crack tip. The IGSCC-CGR model developed here is based on an assumption that crack growth occurs by repeated fracture events occurring within an advancing crack-tip creep-fracture zone. Thermal activation parameters for stress corrosion cracking are obtained by fitting the CGR model to IGSCC-CGR data obtained on NiCrFe alloys, Alloy X-750 and Alloy 600. These IGSCC-CGR activation parameters are compared to activation parameters obtained from creep and stress relaxation tests. Recently reported CGR data, which exhibit an activation energy that depends on yield stress and the applied stress intensity factor, are used to benchmark the model. Finally, the effects of matrix carbon concentration, grain boundary carbides and absorbed hydrogen concentration are discussed within context of the model.

  4. Fatigue-crack propagation in aluminum-lithium alloys processed by power and ingot metallurgy

    SciTech Connect (OSTI)

    Venkateswara Rao, K.T.; Ritchie, R.O. ); Kim, N.J. ); Pizzo, P.P. )

    1990-04-01

    Fatigue-crack propagation behavior in powder-metallurgy (P/M) aluminum-lithium alloys, namely, mechanically-alloyed (MA) Al-4.0Mg-1.5Li-1.1C-0.80{sub 2} (Inco 905-XL) and rapid-solidification-processed (RSP) Al-2.6Li-1.0Cu-0.5Mg-0.5Zr (Allied 644-B) extrusions, has been studied, and results compared with data on an equivalent ingot-metallurgy (I/M) Al-Li alloy, 2090-T81 plate. Fatigue-crack growth resistance of the RSP Al-Li alloy is found to be comparable to the I/M Al-Li alloy; in contrast, crack velocities in MA 905-XL extrusions are nearly three orders of magnitude faster. Growth-rate response in both P/M Al-Li alloys, however, is high anisotropic. Results are interpreted in terms of the microstructural influence of strengthening mechanism, slip mode, grain morphology and texture on the development of crack-tip shielding from crack-path deflection and crack closure. 14 refs., 7 figs., 2 tabs.

  5. Crack growth behavior of encapsulation processed SiC-PMMA particulate composites

    SciTech Connect (OSTI)

    Sheu, C.H.

    1990-05-01

    The effect of processing on the fatigue crack propagation and fracture toughness of ceramic-polymer composites was investigated. A new process for composite production was developed with homogeneous particle distribution and low residual stress levels in mind. PMMA was uniformly distributed by encapsulating the SiC substrate by means of precipitation polymerization. The encapsulation processed powders were then compacted at temperatures above T{sub g} to form the composite. The encapsulation process was optimized by varying the initial concentrations of the reactants until homogeneous nucleation was suppressed. The coatings were found to be continuous at the SiC-PMMA interface, with particle agglomeration occurring between coated particles. Polymer loadings equivalent to 30 vol % SiC were achieved. Composites of several particle size ranges were tested under cyclic fatigue and static loading conditions. Fatigue growth rates and fracture toughness data display a trend of increasing crack growth resistance with increasing particle size, with encapsulation processed composites outperforming conventionally cast composites in both cyclic fatigue and fracture resistance. The largest K{sub Ic} value was found to be 2.95 MPa(m){sup 1/2}, a factor of 3 increase over un-reinforced PMMA. The roles of crack deflection, shielding, bridging, and pinning in enhancing toughness were discussed in light of crack profile fracture surface details. 65 refs., 30 figs., 2 tabs.

  6. Thermal synthesis apparatus and process

    DOE Patents [OSTI]

    Fincke, James R.; Detering, Brent A.

    2004-11-23

    An apparatus for thermal conversion of one or more reactants to desired end products includes an insulated reactor chamber having a high temperature heater such as a plasma torch at its inlet end and, optionally, a restrictive convergent-divergent nozzle at its outlet end. In a thermal conversion method, reactants are injected upstream from the reactor chamber and thoroughly mixed with the plasma stream before entering the reactor chamber. The reactor chamber has a reaction zone that is maintained at a substantially uniform temperature. The resulting heated gaseous stream is then rapidly cooled by passage through the nozzle, which "freezes" the desired end product(s) in the heated equilibrium reaction stage, or is discharged through an outlet pipe without the convergent-divergent nozzle. The desired end products are then separated from the gaseous stream.

  7. Sensitization and SCC (stress corrosion cracking) study on thermally treated inconel 600

    SciTech Connect (OSTI)

    Kai, J-J.; Huang, T.A.; Tsai, C.H.

    1988-01-01

    Stress corrosion cracking (SCC) was recently discovered to be the major cause of failure in Inconel 600 used in steam generator (SG) tubes of pressurized water reactors (PWRs). The failure of the Three Mile Island SG tubes has been attributed to low-temperature SCC in the sulfur-contaminated environment under cold shutdown conditions. Bandy et al. found that even in the 10{sup {minus}6} M Na{sub 2}S{sub 2}O{sub 3} (or N{sub 2}S{sub 4}O{sub 6}) environment, the SCC would still be observable. This study investigates the effect of thermal treatment on the sensitization of Inconel 600 and studies the SCC behavior of this alloy in a sulfur-contaminated environment (S{sub 2}O{sub 3}{sup {minus}2}) using constant load test. The results of this study can be used to correlate the SCC susceptibility to the degree of sensitization of Inconel 600 by defining a critical chromium concentration under the test conditions.

  8. Effect of cold work and processing orientation on stress corrosion cracking behavior of alloy 600

    SciTech Connect (OSTI)

    Moshier, W.C.; Brown, C.M.

    2000-03-01

    Cold work accelerates stress corrosion cracking (SCC) growth rates in Alloy 600 (UNS N06600). However, the variation in crack growth rates generated from cold-worked material has been significant, and the effect has been difficult to quantify. A study was performed in hydrogenated water adjusted to pH 10.2 to evaluate systematically the effect of cold work on Alloy 600 as a function of temperature, amount of cold work, stress intensity factor, and processing orientation. Cold work was introduced into the material by tensile prestraining or cold-rolling plate product. Crack growth rates were determined between 252 C and 360 C, stress intensity factors between 21 MPa{radical}m and 55 MPa{radical}m, and yield strengths between 201 MPa and 827 MPa. The material with the highest yield strength was cold-rolled and tested in the longitudinal-transverse (LT) and short-transverse (ST) orientations. Crack growth rates increased with increasing temperature, stress intensity factor, and yield strength. Furthermore, crack growth rates were a strong function of the processing orientation in the cold-rolled plate, with growth rates approximately an order of magnitude greater in the ST orientation compared to the LT orientation. Crack growth rates in the LT orientation were measured between 0.003 x 10{sup {minus}9} m/s and 1.95 x 10{sup {minus}9} m/s and between 0.066 x 10{sup {minus}9} m/s and 6.3 x 10{sup {minus}9} m/s in the ST orientation. Activation energies were slightly greater in the ST orientation, ranging from 154 kcal/mol to 191 kcal/mol, compared to activation energies between 126 kJ/mol and 157 kJ/mol in the LT orientation. Results of this study demonstrated that, although cold work can be used to accelerate SCC, the orientation of crack growth significantly can affect the results and must be taken into account when analyzing data from cold-worked material.

  9. Percolation Cooling of the Three Mile Island Unit 2 Lower Head by Way of Thermal Cracking and Gap Formation

    SciTech Connect (OSTI)

    Thomsen, K.L.

    2002-01-15

    Two partial models have been developed to elucidate the Three Mile Island Unit 2 lower head coolability by water percolation from above into the thermally cracking debris bed and into a gap between the debris and the wall. The bulk permeability of the cracked top crust is estimated based on simple fracture mechanics and application of Poiseuille's law to the fractures. The gap is considered as an abstraction representing an initially rugged interface, which probably expanded by thermal deformation and cracking in connection with the water ingress. The coupled flow and heat conduction problem for the top crust is solved in slab geometry based on the two-phase Darcy equations together with quasi-steady mass and energy conservation equations. The resulting water penetration depth is in good agreement with the depth of the so-called loose debris bed. The lower-head and bottom-crust problem is treated analogously by a two-dimensional axisymmetric model. The notion of a gap is maintained as a useful concept in the flow analysis. Simulations show that a central hot spot with a peak wall temperature of 1075 to 1100 deg. C can be obtained, but the quenching rates are not satisfactory. It is concluded that a three-dimensional model with an additional mechanism to explain the sudden water ingress to the hot spot center would be more appropriate.

  10. List of Solar Thermal Process Heat Incentives | Open Energy Informatio...

    Open Energy Info (EERE)

    List of Solar Thermal Process Heat Incentives Jump to: navigation, search The following contains the list of 211 Solar Thermal Process Heat Incentives. CSV (rows 1 - 211) Incentive...

  11. Environmental Cracking of Corrosion Resistant Alloys in the Chemical Process Industry - A Review

    SciTech Connect (OSTI)

    Rebak, R B

    2006-12-04

    A large variety of corrosion resistant alloys are used regularly in the chemical process industry (CPI). The most common family of alloys include the iron (Fe)-based stainless steels, nickel (Ni) alloys and titanium (Ti) alloys. There also other corrosion resistant alloys but their family of alloys is not as large as for the three groups mentioned above. All ranges of corrosive environments can be found in the CPI, from caustic solutions to hot acidic environments, from highly reducing to highly oxidizing. Stainless steels are ubiquitous since numerous types of stainless steels exist, each type tailored for specific applications. In general, stainless steels suffer stress corrosion cracking (SCC) in hot chloride environments while high Ni alloys are practically immune to this type of attack. High nickel alloys are also resistant to caustic cracking. Ti alloys find application in highly oxidizing solutions. Solutions containing fluoride ions, especially acid, seem to be aggressive to almost all corrosion resistant alloys.

  12. Thermally activated low temperature creep and primary water stress corrosion cracking of NiCrFe alloys

    SciTech Connect (OSTI)

    Hall, M.M. Jr.

    1993-10-01

    A phenomenological SCC-CGR model is developed based on an apriori assumption that the SCC-CGR is controlled by low temperature creep (LTC). This mode of low temperature time dependent deformation occurs at stress levels above the athermal flow stress by a dislocation glide mechanism that is thermally activated and may be environmentally assisted. The SCC-CGR model equations developed contain thermal activation parameters descriptive of the dislocation creep mechanism. Thermal activation parameters are obtained by fitting the CGR model to SCC-CGR data obtained on Alloy 600 and Alloy X-750. These SCC-CGR activation parameters are compared to LTC activation parameters obtained from stress relaxation tests. When the high concentration of hydrogen at the tip of an SCC crack is considered, the SCC-CGR activation energies and rate sensitivities are shown to be quantitatively consistent with hydrogen reducing the activation energy and increasing the strain rate sensitivity in LTC stress relaxation tests. Stress dependence of SCC-CGR activation energy consistent with that found for the LTC activation energy. Comparisons between temperature dependence of the SCC-CGR stress sensitivity and LTC stress sensitivity provide a basis for speculation on effects of hydrogen and solute carbon on SCC crack growth rates.

  13. Value of solar thermal industrial process heat

    SciTech Connect (OSTI)

    Brown, D.R.; Fassbender, L.L.; Chockie, A.D.

    1986-03-01

    This study estimated the value of solar thermal-generated industrial process heat (IPH) as a function of process heat temperature. The value of solar thermal energy is equal to the cost of producing energy from conventional fuels and equipment if the energy produced from either source provides an equal level of service. This requirement put the focus of this study on defining and characterizing conventional process heat equipment and fuels. Costs (values) were estimated for 17 different design points representing different combinations of conventional technologies, temperatures, and fuels. Costs were first estimated for median or representative conditions at each design point. The cost impact of capacity factor, efficiency, fuel escalation rate, and regional fuel price differences were then evaluated by varying each of these factors within credible ranges.

  14. 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.

  15. 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 (<0.05), while the residual oxygen rangedmore » 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

  16. Synthesis report on thermally driven coupled processes

    SciTech Connect (OSTI)

    Hardin, E.L.

    1997-10-15

    The main purpose of this report is to document observations and data on thermally coupled processes for conditions that are expected to occur within and around a repository at Yucca Mountain. Some attempt is made to summarize values of properties (e.g., thermal properties, hydrologic properties) that can be measured in the laboratory on intact samples of the rock matrix. Variation of these properties with temperature, or with conditions likely to be encountered at elevated temperature in the host rock, is of particular interest. However, the main emphasis of this report is on direct observation of thermally coupled processes at various scales. Direct phenomenological observations are vitally important in developing and testing conceptual models. If the mathematical implementation of a conceptual model predicts a consequence that is not observed, either (1) the parameters or the boundary conditions used in the calculation are incorrect or (2) the conceptual basis of the model does not fit the experiment; in either case, the model must be revised. For example, the effective continuum model that has been used in thermohydrology studies combines matrix and fracture flow in a way that is equivalent to an assumption that water is imbibed instantaneously from fractures into adjacent, partially saturated matrix. Based on this approximation, the continuum-flow response that is analogous to fracture flow will not occur until the effective continuum is almost completely saturated. This approximation is not entirely consistent with some of the experimental data presented in this report. This report documents laboratory work and field studies undertaken in FY96 and FY97 to investigate thermally coupled processes such as heat pipes and fracture-matrix coupling. In addition, relevant activities from past years, and work undertaken outside the Yucca Mountain project are summarized and discussed. Natural and artificial analogs are also discussed to provide a convenient source of

  17. Continuous Processing of High Thermal Conductivity Polyethylene Fibers and Sheets

    Broader source: Energy.gov [DOE]

    Project to develop and validate a continuous manufacturing process for polyethylene fibers and sheets yielding a thermal conductivity value greater than 60 W/m.K.

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

    DOE Patents [OSTI]

    Ott, Ronald D.; Blue, Craig A.; Dudney, Nancy J.; Harper, David C.

    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.

  19. Thermal processing system concepts and considerations for RWMC buried waste

    SciTech Connect (OSTI)

    Eddy, T.L.; Kong, P.C.; Raivo, B.D.; Anderson, G.L.

    1992-02-01

    This report presents a preliminary determination of ex situ thermal processing system concepts and related processing considerations for application to remediation of transuranic (TRU)-contaminated buried wastes (TRUW) at the Radioactive Waste Management Complex (RWMC) of the Idaho National Engineering Laboratory (INEL). Beginning with top-level thermal treatment concepts and requirements identified in a previous Preliminary Systems Design Study (SDS), a more detailed consideration of the waste materials thermal processing problem is provided. Anticipated waste stream elements and problem characteristics are identified and considered. Final waste form performance criteria, requirements, and options are examined within the context of providing a high-integrity, low-leachability glass/ceramic, final waste form material. Thermal processing conditions required and capability of key systems components (equipment) to provide these material process conditions are considered. Information from closely related companion study reports on melter technology development needs assessment and INEL Iron-Enriched Basalt (IEB) research are considered. Five potentially practicable thermal process system design configuration concepts are defined and compared. A scenario for thermal processing of a mixed waste and soils stream with essentially no complex presorting and using a series process of incineration and high temperature melting is recommended. Recommendations for applied research and development necessary to further detail and demonstrate the final waste form, required thermal processes, and melter process equipment are provided.

  20. Process and apparatus for thermal enhancement

    DOE Patents [OSTI]

    Burrill, Jr., Charles E.; Smirlock, Martin E.; Krepchin, Ira P.

    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.

  1. Automated Process for the Fabrication of Highly Customized Thermally

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

    Insulated Cladding Systems | Department of Energy Automated Process for the Fabrication of Highly Customized Thermally Insulated Cladding Systems Automated Process for the Fabrication 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 cuts foam insulating via a process known as computer numerically controlled (CNC) foam cutting. Image: Worcester Polytechnic Institute

  2. Automated Process for the Fabrication of Highly Customized Thermally

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

    Insulated Cladding Systems | Department of Energy Automated Process for the Fabrication of Highly Customized Thermally Insulated Cladding Systems Automated Process for the Fabrication of Highly Customized Thermally Insulated Cladding Systems 1 of 2 Resin casting prototype Image: Worcester Polytechnic Institute 2 of 2 A project member completes cuts foam insulating via a process known as computer numerically controlled (CNC) foam cutting. Image: Worcester Polytechnic Institute Lead Performer:

  3. 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.

  4. 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.

  5. Electrochemical Interpretation of a Stress Corrosion Cracking of Thermally Treated Ni base Alloys in a Lead Contaminated Water

    SciTech Connect (OSTI)

    Hwang, Seong Sik; Lim, Yun Soo; Kim, Hong Pyo; Kim, Joung Soo; Thomas, Larry E.

    2007-08-20

    Since the PbSCC(Lead stress corrosion cracking) of alloy 600 tubing materials was reported by Copson and Dean in 1965, the effect of lead on a corrosion film and cracking morphology have been continually debated. An electrochemical interaction of lead with the alloying elements of SG tubings was studied and the corrosion products were analyzed. It was found that lead enhanced the anodic dissolution of alloy 600 and alloy 690 in the electrochemical test. The lead preferentially dissolved the Cr from the corrosion film of alloy 600 and alloy 690 in alkaline water. The lead ion seemed to penetrate into the TG crack tip and react with the corrosion film. A selective Cr depletion was observed to weaken the stability of the passive film on the alloys. Whereas passivity of Ni became stable in lead containing solution, Cr and Fe passivity became unstable.

  6. Pulse Thermal Processing of Functional Materials Using a Directed Plasma

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

    Arc - Energy Innovation Portal Early Stage R&D Early Stage R&D Advanced Materials Advanced Materials Find More Like This Return to Search Pulse Thermal Processing of Functional Materials Using a Directed Plasma Arc Oak Ridge National Laboratory Contact ORNL About This Technology Technology Marketing SummaryUsing pulses of high density infrared light from a directed plasma arc, ORNL researchers invented a method to thermally process thin films and other functional materials on

  7. 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.

  8. Thermal Systems Process and Components Laboratory (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2011-10-01

    This fact sheet describes the purpose, lab specifications, applications scenarios, and information on how to partner with NREL's Thermal Systems Process and Components Laboratory at the Energy Systems Integration Facility. The focus of the Thermal Systems Process and Components Laboratory at NREL's Energy Systems Integration Facility (ESIF) is to research, develop, test, and evaluate new techniques for thermal energy storage systems that are relevant to utility-scale concentrating solar power plants. The laboratory holds test systems that can provide heat transfer fluids for the evaluation of heat exchangers and thermal energy storage devices. The existing system provides molten salt at temperatures up to 800 C. This unit is charged with nitrate salt rated to 600 C, but is capable of handling other heat transfer fluid compositions. Three additional test bays are available for future deployment of alternative heat transfer fluids such as hot air, carbon dioxide, or steam systems. The Thermal Systems Process and Components Laboratory performs pilot-scale thermal energy storage system testing through multiple charge and discharge cycles to evaluate heat exchanger performance and storage efficiency. The laboratory equipment can also be utilized to test instrument and sensor compatibility with hot heat transfer fluids. Future applications in the laboratory may include the evaluation of thermal energy storage systems designed to operate with supercritical heat transfer fluids such as steam or carbon dioxide. These tests will require the installation of test systems capable of providing supercritical fluids at temperatures up to 700 C.

  9. Thermal Modeling of A Friction Bonding Process

    SciTech Connect (OSTI)

    John Dixon; Douglas Burkes; Pavel Medvedev

    2007-10-01

    A COMSOL model capable of predicting temperature evolution during nuclear fuel fabrication is being developed at the Idaho National Laboratory (INL). Fuel plates are fabricated by friction bonding (FB) uranium-molybdenum (U-Mo) alloy foils positioned between two aluminum plates. The ability to predict temperature distribution during fabrication is imperative to ensure good quality bonding without inducing an undesirable chemical reaction between U-Mo and aluminum. A three-dimensional heat transfer model of the FB process implementing shallow pin penetration for cladding monolithic nuclear fuel foils is presented. Temperature distribution during the FB process as a function of fabrication parameters such as weld speed, tool load, and tool rotational frequency are predicted. Model assumptions, settings, and equations are described in relation to standard friction stir welding. Current experimental design for validation and calibration of the model is also demonstrated. Resulting experimental data reveal the accuracy in describing asymmetrical temperature distributions about the tool face. Temperature of the bonded plate drops beneath the pin and is higher on the advancing side than the retreating side of the tool.

  10. 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.

  11. Process for fabricating composite material having high thermal conductivity

    DOE Patents [OSTI]

    Colella, Nicholas J.; Davidson, Howard L.; Kerns, John A.; Makowiecki, Daniel M.

    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.

  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

  13. 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.

  14. Process management using component thermal-hydraulic function classes

    DOE Patents [OSTI]

    Morman, James A.; Wei, Thomas Y. C.; Reifman, Jaques

    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.

  15. Thermal acidization and recovery process for recovering viscous petroleum

    DOE Patents [OSTI]

    Poston, Robert S.

    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.

  16. Multi-component catalyst mixture and process for catalytic cracking of heavy hydrocarbon feed to lighter products

    SciTech Connect (OSTI)

    Herbst, J.A.; Owen, H.; Schipper, P.H.

    1991-10-08

    This paper describes a catalytic cracking catalyst. It comprises: a bulk conversion cracking catalyst containing at least one component with an equivalent pore size of at least about 7 angstroms in a matrix, the bulk conversion cracking catalyst having physical properties which permit use in a fluidized or moving bed catalytic cracking reactor; a light paraffin upgrading catalyst comprising at least one zeolite having a constraint index of 1--12 and paraffin cracking/isomerization activity; and a light paraffin upgrading catalyst comprising at least one zeolite having a constraint index of 1--12 and paraffin aromatization activity, and wherein the upgrading catalysts have substantially the same physical properties as the bulk conversion cracking catalyst.

  17. Agricultural Mixed Waster Biorefinery Using Thermal Conversion Process

    SciTech Connect (OSTI)

    2006-08-01

    This Congressionally-mandated project is supporting efforts to develop a demonstration facility that will use the patented Thermal Conversion Process (TCP) to produce fuel, power and chemicals from poultry waste and agricultural wastes such as animal and vegetable grease and wastewater sludge.

  18. Method and apparatus for thermal processing of semiconductor substrates

    DOE Patents [OSTI]

    Griffiths, Stewart K.; Nilson, Robert H.; Mattson, Brad S.; Savas, Stephen E.

    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.

  19. Method and apparatus for thermal processing of semiconductor substrates

    DOE Patents [OSTI]

    Griffiths, Stewart K.; Nilson, Robert H.; Mattson, Brad S.; Savas, Stephen E.

    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.

  20. 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.

  1. Supporting technology for enhanced oil recovery - EOR thermal processes

    SciTech Connect (OSTI)

    1995-03-01

    This report contains the results of efforts under the six tasks of the Eighth Amendment and Extension of Annex IV, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Agreement. The report is presented in sections 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.

  2. 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)

  3. 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.

  4. Fracture toughness of plasma-sprayed thermal barrier ceramics: Influence of processing, microstructure, and thermal aging

    SciTech Connect (OSTI)

    Dwivedi, Gopal; Viswanathan, Vaishak; Sampath, Sanjay; Shyam, Amit; Lara-Curzio, Edgar

    2014-06-09

    Fracture toughness has become one of the dominant design parameters that dictates the selection of materials and their microstructure to obtain durable thermal barrier coatings (TBCs). Much progress has been made in characterizing the fracture toughness of relevant TBC compositions in bulk form, and it has become apparent that this property is significantly affected by process-induced microstructural defects. In this investigation, a systematic study of the influence of coating microstructure on the fracture toughness of atmospheric plasma sprayed (APS) TBCs has been carried out. Yttria partially stabilized zirconia (YSZ) coatings were fabricated under different spray process conditions inducing different levels of porosity and interfacial defects. Fracture toughness was measured on free standing coatings in as-processed and thermally aged conditions using the double torsion technique. Results indicate significant variance in fracture toughness among coatings with different microstructures including changes induced by thermal aging. Comparative studies were also conducted on an alternative TBC composition, Gd2Zr2O7 (GDZ), which as anticipated shows significantly lower fracture toughness compared to YSZ. Furthermore, the results from these studies not only point towards a need for process and microstructure optimization for enhanced TBC performance but also a framework for establishing performance metrics for promising new TBC compositions.

  5. Fracture toughness of plasma-sprayed thermal barrier ceramics: Influence of processing, microstructure, and thermal aging

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

    Dwivedi, Gopal; Viswanathan, Vaishak; Sampath, Sanjay; Shyam, Amit; Lara-Curzio, Edgar

    2014-06-09

    Fracture toughness has become one of the dominant design parameters that dictates the selection of materials and their microstructure to obtain durable thermal barrier coatings (TBCs). Much progress has been made in characterizing the fracture toughness of relevant TBC compositions in bulk form, and it has become apparent that this property is significantly affected by process-induced microstructural defects. In this investigation, a systematic study of the influence of coating microstructure on the fracture toughness of atmospheric plasma sprayed (APS) TBCs has been carried out. Yttria partially stabilized zirconia (YSZ) coatings were fabricated under different spray process conditions inducing different levelsmore » of porosity and interfacial defects. Fracture toughness was measured on free standing coatings in as-processed and thermally aged conditions using the double torsion technique. Results indicate significant variance in fracture toughness among coatings with different microstructures including changes induced by thermal aging. Comparative studies were also conducted on an alternative TBC composition, Gd2Zr2O7 (GDZ), which as anticipated shows significantly lower fracture toughness compared to YSZ. Furthermore, the results from these studies not only point towards a need for process and microstructure optimization for enhanced TBC performance but also a framework for establishing performance metrics for promising new TBC compositions.« less

  6. Pulse Thermal Processing for Low Thermal Budget Integration of IGZO Thin Film Transistors

    SciTech Connect (OSTI)

    Noh, Joo Hyon; Joshi, Pooran C.; Kuruganti, Teja; Rack, Philip D.

    2014-11-26

    Pulse thermal processing (PTP) has been explored for low thermal budget integration of indium gallium zinc oxide (IGZO) thin film transistors (TFTs). The IGZO TFTs are exposed to a broadband (0.2-1.4 m) arc lamp radiation spectrum with 100 pulses of 1 msec pulse width. The impact of radiant exposure power on the TFT performance was analyzed in terms of the switching characteristics and bias stress reliability characteristics, respectively. The PTP treated IGZO TFTs with power density of 3.95 kW/cm2 and 0.1 sec total irradiation time showed comparable switching properties, at significantly lower thermal budget, to furnace annealed IGZO TFT. The typical field effect mobility FE, threshold voltage VT, and sub-threshold gate swing S.S were calculated to be 7.8 cm2/ V s, 8.1 V, and 0.22 V/ decade, respectively. The observed performance shows promise for low thermal budget TFT integration on flexible substrates exploiting the large-area, scalable PTP technology.

  7. Pulse Thermal Processing for Low Thermal Budget Integration of IGZO Thin Film Transistors

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

    Noh, Joo Hyon; Joshi, Pooran C.; Kuruganti, Teja; Rack, Philip D.

    2014-11-26

    Pulse thermal processing (PTP) has been explored for low thermal budget integration of indium gallium zinc oxide (IGZO) thin film transistors (TFTs). The IGZO TFTs are exposed to a broadband (0.2-1.4 m) arc lamp radiation spectrum with 100 pulses of 1 msec pulse width. The impact of radiant exposure power on the TFT performance was analyzed in terms of the switching characteristics and bias stress reliability characteristics, respectively. The PTP treated IGZO TFTs with power density of 3.95 kW/cm2 and 0.1 sec total irradiation time showed comparable switching properties, at significantly lower thermal budget, to furnace annealed IGZO TFT. Themore » typical field effect mobility FE, threshold voltage VT, and sub-threshold gate swing S.S were calculated to be 7.8 cm2/ V s, 8.1 V, and 0.22 V/ decade, respectively. The observed performance shows promise for low thermal budget TFT integration on flexible substrates exploiting the large-area, scalable PTP technology.« less

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

    DOE Patents [OSTI]

    Jantzen, Carol M.

    1995-01-01

    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.

  9. Thermally stable booster explosive and process for manufacture

    DOE Patents [OSTI]

    Quinlin, William T.; Thorpe, Raymond; Lightfoot, James M.

    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.

  10. 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.

  11. 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.

  12. Continuous Processing of High Thermal Conductivity Fibers and Sheets

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

    Professor Gang Chen, Carl Richard Soderberg Professor of Power Engineering 617-253-0006 (phone), 617-324-5545 (fax) gchen2@mit.edu U.S. DOE Advanced Manufacturing Office Peer Review Meeting Washington, D.C. May 6-7, 2014 This presentation does not contain any proprietary, confidential, or otherwise restricted information. Project Objective  Plastics are less expensive, lighter, and require less energy to process than metals; however, they have low thermal conductivity values (~0.3 W/mK) 

  13. Toward Improving the Type IV Cracking Resistance in Cr-Mo Steel Weld Through Thermo-Mechanical Processing

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

    Shassere, Benjamin A.; Yamamoto, Yukinori; Babu, Sudarsanam Suresh

    2016-02-23

    Detailed microstructure characterization of Grade 91 (Modified 9Cr-1Mo, ASTM A387) steel subjected to a thermo-mechanical treatment (TMT) process was performed to rationalize the cross-weld creep properties. A series of thermo-mechanical processing in the austenite phase region, followed by isothermal aging at temperatures at 973 to 1173 K (700 to 900ºC) was applied to the Grade 91 steel to promote precipitation kinetics of MX (M: Nb and V, X: C and N) in the austenite matrix. Detailed characterization of the base metals after standard tempering confirmed the presence of fine MX dispersion within the tempered martensitic microstructure in steels processed at/andmore » above 1073 K (800 ºC). Relatively low volume fraction of M23C6 precipitates was observed after processing at 1073 K (800 ºC). The cross-weld creep strength after processing was increased with respect to the increase of MX dispersion, indicating that these MX precipitates maintained during weld thermal cycles in the fine grained heat affected zone (FGHAZ) region and thereby contribute to improved creep resistant of welds in comparison to the welds made with the standard “normalization and tempering” processes. Lastly, the steels processed in this specific processing condition showed improved cross-weld creep resistance and sufficient room-temperature toughness. The above data is also analysed based on existing theories of creep deformation based on dislocation climb mechanism.« less

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

    Office of Scientific and Technical Information (OSTI)

    Avoiding Carbon Bed Hot Spots in Thermal Process Off-Gas Systems Citation Details In-Document Search Title: Avoiding Carbon Bed Hot Spots in Thermal Process Off-Gas Systems You ...

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

    Office of Scientific and Technical Information (OSTI)

    Conference: Avoiding Carbon Bed Hot Spots in Thermal Process Off-Gas Systems Citation Details In-Document Search Title: Avoiding Carbon Bed Hot Spots in Thermal Process Off-Gas ...

  16. 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.

  17. 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.; Reed, Scott T.; Ashley, Carol S.; Neiser, Richard A.; Moffatt, William C.

    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.

  18. Thermal processing of EVA encapsulants and effects of formulation additives

    SciTech Connect (OSTI)

    Pern, F.J.; Glick, S.H.

    1996-05-01

    The authors investigated the in-situ processing temperatures and effects of various formulation additives on the formation of ultraviolet (UV) excitable chromophores, in the thermal lamination and curing of ethylene-vinyl acetate (EVA) encapsulants. A programmable, microprocessor-controlled, double-bag vacuum laminator was used to study two commercial as formulated EVA films, A9918P and 15295P, and solution-cast films of Elvaxrm (EVX) impregnated with various curing agents and antioxidants. The results show that the actual measured temperatures of EVA lagged significantly behind the programmed profiles for the heating elements and were affected by the total thermal mass loaded inside the laminator chamber. The antioxidant Naugard P{trademark}, used in the two commercial EVA formulations, greatly enhances the formation of UV-excitable, short chromophores upon curing, whereas other tested antioxidants show little effect. A new curing agent chosen specifically for the EVA formulation modification produces little or no effect on chromophore formation, no bubbling problems in the glass/EVX/glass laminates, and a gel content of {approximately}80% when cured at programmed 155{degrees}C for 4 min. Also demonstrated is the greater discoloring effect with higher concentrations of curing-generated chromophores.

  19. 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.

  20. New processing technique for DEB powder for thermal batteries

    SciTech Connect (OSTI)

    Szwarc, R.; Walton, R.D.

    1980-06-01

    The purpose of this paper is to explore how material processing influences thermal battery performance, and how battery performance can be improved by changes in processing. This discussion is confined to the class of thermal batteries designed by Sandia Laboratories and built under the supervision of General Electric in St. Petersburg, Florida. The electrochemical system employed is: Ca/LiCl-KCl-CaCrO/sub 4//Fe. These batteries are primary reserve batteries which employ a pelletized cell design. Each cell consists of an electrolyte-depolarizer pellet sandwiched between an anode and a heat pellet. The anode employed may be one of two forms: sheet calcium disc, mechanically attached to an iron or steel backing; or a substrate disc of iron or steel on which 3 to 5 mils of calcium had been evaporated. The depolarizer-electrolyte, commonly referred to as DEB, is composed of CaCrO/sub 4/, LiCl-KCl eutectic and SiO/sub 2/ binder powder, which has been blended and pressed into pellets. The DEB pellet serves as electrolyte and as active cathode when the salt becomes molten upon battery activation. The heat pellet serves the dual purpose of providing the heat necessary to activate the battery and as the cathode current collector. The heat pellet is composed of iron powder and KClO/sub 4/. A battery is made up of one or more stacks of about 12 cells connected in series to produce a voltage of 28 to 32 volts. Since activated life requirements for batteries vary from seconds up to one hour, the battery must be well insulated to conserve the heat produced by the ignition of the heat pellets to maintain the electrolyte in a molten state. This insulation is also important to protect sensitive electronic components in contact with the battery case. Because the electrolyte, particularly LiCl, is hygroscopic, the batteries are hermetically sealed in stainless steel cans, and are manufactured in dryrooms maintained at 3% relative humidity or better.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. Technical Letter Report - Analysis of Ultrasonic Data on Piping Cracks at Ignalina Nuclear Power Plant Before and After Applying a Mechanical Stress Improvement Process, JCN-N6319, Task 2

    SciTech Connect (OSTI)

    Anderson, Michael T.; Cumblidge, Stephen E.; Crawford, Susan L.

    2008-02-26

    Pacific Northwest National Laboratory (PNNL) is assisting the United States Nuclear Regulatory Commission (NRC) in developing a position on the management of primary water stress corrosion cracking (PWSCC) in piping systems previously analyzed for leak-before-break (LBB). Part of this work involves determining whether inspections alone are sufficient or if inspections plus mitigation techniques are needed. The work described in this report addresses the reliability of ultrasonic phased-array (PA) examinations for inspection of cracks that have been subjected to the mitigation method of mechanical stress improvement process (MSIP). It is believed that stresses imparted during MSIP may make ultrasonic crack responses in piping welds more difficult to detect and accurately characterize. To explore this issue, data were acquired, both before and after applying MSIP, and analyzed from cracked areas in piping at the Ignalina Nuclear Power Plant (INPP) in Lithuania. This work was performed under NRC Project JCN-N6319, PWSCC in Leak-Before-Break Systems.

  6. The analysis of cracks in high-pressure piping and their effects on strength and lifetime of construction components at the Ignalina nuclear plant

    SciTech Connect (OSTI)

    Aleev, A.; Petkevicius, K.; Senkus, V.

    1997-04-01

    A number of cracks and damages of other sorts have been identified in the high-pressure parts at the Ignalina Nuclear Plant. They are caused by inadequate production- and repair technologies, as well as by thermal, chemical and mechanical processes of their performance. Several techniques are available as predictions of cracks and other defects of pressurized vessels. The choice of an experimental technique should be based on the level of its agreement with the actual processes.

  7. 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.

  8. Experience base for Radioactive Waste Thermal Processing Systems: A preliminary survey

    SciTech Connect (OSTI)

    Mayberry, J.; Geimer, R.; Gillins, R.; Steverson, E.M.; Dalton, D.; Anderson, G.L.

    1992-04-01

    In the process of considering thermal technologies for potential treatment of the Idaho National Engineering Laboratory mixed transuranic contaminated wastes, a preliminary survey of the experience base available from Radioactive Waste Thermal Processing Systems is reported. A list of known commercial radioactive waste facilities in the United States and some international thermal treatment facilities are provided. Survey focus is upon the US Department of Energy thermal treatment facilities. A brief facility description and a preliminary summary of facility status, and problems experienced is provided for a selected subset of the DOE facilities.

  9. Heavy oil catalytic cracking apparatus (Patent) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    It comprises a catalytic cracking reactor means; a separation means connective with the ... PETROLEUM REFINERIES; CATALYSTS; SEPARATION PROCESSES; CHEMICAL REACTIONS; ...

  10. Hydrogen-induced cracking in pure iron

    SciTech Connect (OSTI)

    Armstrong, J.H.; Carpenter, S.H.

    1985-01-01

    The modulus and internal friction of Armco iron were continuously measured during cathodic charging with hydrogen to investigate crack initiation and growth. The observed modulus decrease was attributed to crack initiation and growth. The internal friction increase during cathodic charging was attributed to plastic deformation accompanying the crack formation. Both the modulus and internal friction behavior were found to be a sum of two parallel exponential processes. The two exponential processes were consistent with different sources of carbon for the crack-producing hydrogen bubble nucleation.

  11. 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.

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

    DOE Patents [OSTI]

    Kuzay, Tuncer M.

    1992-01-01

    A method 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.

  13. Thermal and Non-thermal Physiochemical Processes in Nanoscale Films of Amorphous Solid Water

    SciTech Connect (OSTI)

    Smith, R. Scott; Petrik, Nikolay G.; Kimmel, Gregory A.; Kay, Bruce D.

    2012-01-17

    Amorphous solid water (ASW) is a metastable form of water created by vapor deposition onto a cold substrate (typically less than 130 K). Since this unusual form of water only exists on earth in laboratories with highly specialized equipment, it is fair to ask why there is any interest in studying this esoteric material. Much of the scientific interest involves using ASW as a model system to explore the physical and reactive properties of liquid water and aqueous solutions. Other researchers are interested in ASW because it is believed to be the predominate form of water in the extreme cold temperatures found in many astrophysical and planetary environments. In addition, ASW is a convenient model system for studying the stability of metastable systems (glasses) and the properties of highly porous materials. A fundamental understanding of such properties has applications in a diverse range of disciplines including cryobiology, food science, pharmaceuticals, astrophysics and nuclear waste storage among others.There exist several excellent reviews on the properties of ASW and supercooled liquid water and a new comprehensive review is beyond the scope of this Account. Instead, we focus on our research over the past 15 years using molecular beams and surface science techniques to probe the thermal and non thermal properties of nanoscale films of ASW. We use molecular beams to precisely control the deposition conditions (flux, incident, energy, incident angle) to create compositionally-tailored, nanoscale films of ASW at low temperatures. To study the transport properties (viscosity, diffusivity), the amorphous films can be heated above their glass transition temperatures, Tg, at which time they transform into deeply supercooled liquids prior to crystallization. The advantage of this approach is that at temperatures near Tg the viscosity is approximately 15 orders of magnitude larger than a normal liquid, and therefore the crystallization kinetics are dramatically slowed

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

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

    Image: Worcester Polytechnic Institute 2 of 2 A project member completes cuts foam insulating via a process known as computer numerically controlled (CNC) foam cutting. Image: ...

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

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

    Funding Opportunity Announcement: Small Business Technology Transfer Phase I, Topic 3b ... The fragmented retrofitting process and onsite construction methods often result in wall ...

  16. Crack initiation under generalized plane strain conditions

    SciTech Connect (OSTI)

    Shum, D.K.M.; Merkle, J.G.

    1991-01-01

    A method for estimating the decrease in crack-initiation toughness, from a reference plane strain value, due to positive straining along the crack front of a circumferential flaw in a reactor pressure vessel is presented in this study. This method relates crack initiation under generalized plane strain conditions with material failure at points within a distance of a few crack-tip-opening displacements ahead of a crack front, and involves the formulation of a micromechanical crack-initiation model. While this study is intended to address concerns regarding the effects of positive out-of- plane straining on ductile crack initiation, the approach adopted in this work can be extended in a straightforward fashion to examine conditions of macroscopic cleavage crack initiation. Provided single- parameter dominance of near-tip fields exists in the flawed structure, results from this study could be used to examine the appropriateness of applying plane strain fracture toughness to the evaluation of circumferential flaws, in particular to those in ring-forged vessels which have no longitudinal welds. In addition, results from this study could also be applied toward the analysis of the effects of thermal streaming on the fracture resistance of circumferentially oriented flaws in a pressure vessel. 37 refs., 8 figs., 1 tab.

  17. Engineering process instructions and development summary MC3642 thermal battery

    SciTech Connect (OSTI)

    Jacobs, D.

    1981-06-01

    The MC3642 is a dual channel thermal battery used on the DE1010/W85 Command Disable Controller. It utilizes the CalCaCrO{sub 4} electrochemical system. The electrical requirements of this battery are as follows: RISE TIME PEAK VOLTAGE ACTIVE LIFE LOAD Channel 1 - 1.0 Sec. Max. 34 Volts 10 Sec. Min. 40.0 Ohms to 20 Volts above 20 Volts Channel 2 - .350 Sec. Max. 42 Volts 10 MSec. Min. 6.5 Ohms to 23 Volts above 23 Volts The battery consists of 14 cells connected in series (Channel 2) and 12 cells connected in series (Channel 1). Each cell is composed of an anode fabricated from a bimetallic sheet (0.005{double_prime} thick calcium on 0.005{double_prime} thick iron substrate), a depolarizer-electrolyte-binder (DEB) pellet and a heat pellet. Activation is achieved by mechanical primer. Optimum battery performance is achieved with a 35155/10 DEB pellet weighing .80g and a heat pellet, weighing 1.30 grams, of 88/12 heat powder.

  18. 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)

  19. Nonlinear structural crack growth monitoring

    DOE Patents [OSTI]

    Welch, Donald E.; Hively, Lee M.; Holdaway, Ray F.

    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.

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

    DOE Patents [OSTI]

    Colella, Nicholas J.; Davidson, Howard L.; Kerns, John A.; Makowiecki, Daniel M.

    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.

  1. 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.

  2. Solar-Thermal Fluid-Wall Reaction Processing - Energy Innovation Portal

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

    Hydrogen and Fuel Cell Hydrogen and Fuel Cell Find More Like This Return to Search Solar-Thermal Fluid-Wall Reaction Processing University of Colorado National Renewable Energy Laboratory Contact CU About This Technology Technology Marketing Summary Currently most hydrogen is produced through a process of heating natural gas with water vapor called steam reforming. This process requires energy to heat the gasses and produces greenhouse gases such as CO2 as its byproducts. These conditions

  3. 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.

  4. THERMODYNAMIC CONSIDERATIONS FOR THERMAL WATER SPLITTING PROCESSES AND HIGH TEMPERATURE ELECTROLYSIS

    SciTech Connect (OSTI)

    J. E. O'Brien

    2008-11-01

    A general thermodynamic analysis of hydrogen production based on thermal water splitting processes is presented. Results of the analysis show that the overall efficiency of any thermal water splitting process operating between two temperature limits is proportional to the Carnot efficiency. Implications of thermodynamic efficiency limits and the impacts of loss mechanisms and operating conditions are discussed as they pertain specifically to hydrogen production based on high-temperature electrolysis. Overall system performance predictions are also presented for high-temperature electrolysis plants powered by three different advanced nuclear reactor types, over their respective operating temperature ranges.

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

    DOE Patents [OSTI]

    Sheldon, Ray W.

    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.

  6. 3:2:1 Crack Spread

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    To calculate the 3:2:1 crack spread for a Gulf Coast refinery that processes Louisiana Light Sweet (LLS) crude oil, add the spot price for two barrels of Gulf Coast conventional ...

  7. Impact of pulse thermal processing on the properties of inkjet printed metal and flexible sensors

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

    Joshi, Pooran C.; Kuruganti, Teja; Killough, Stephen M.

    2015-03-11

    In this paper, we report on the low temperature processing of environmental sensors employing pulse thermal processing (PTP) technique to define a path toward flexible sensor technology on plastic, paper, and fabric substrates. Inkjet printing and pulse thermal processing technique were used to realize mask-less, additive integration of low-cost sensors on polymeric substrates with specific focus on temperature, humidity, and strain sensors. The printed metal line performance was evaluated in terms of the electrical conductivity characteristics as a function of post-deposition thermal processing conditions. The PTP processed Ag metal lines exhibited high conductivity with metal sheet resistance values below 100more » mΩ/{whitesquare} using a pulse width as short as 250 μs. The flexible temperature and relative humidity sensors were defined on flexible polyimide substrates by direct printing of Ag metal structures. The printed resistive temperature sensor and capacitive humidity sensor were characterized for their sensitivity with focus on future smart-building applications. Strain gauges were printed on polyimide substrate to determine the mechanical properties of the silver nanoparticle films. Finally, the observed electrical properties of the printed metal lines and the sensitivity of the flexible sensors show promise for the realization of a high performance print-on-demand technology exploiting low thermal-budget PTP technique.« less

  8. Study of hydrogen induced cracking in iron

    SciTech Connect (OSTI)

    Armstrong, J.H.

    1985-01-01

    The hydrogen assisted crack growth of Armco iron from cathodic charging was studied using continuous measurements of the modulus and internal friction. A Marx composite piezoelectric oscillator was used to measure resonant frequency and internal friction during the cathodic charging. Internal friction measured before and after cathodic charging was separated into dislocation and magnetic effects. The effects of charging time, vibratory strain amplitude and charging current density were studied. In all cases the modulus decreased continuously during cathodic charging. The internal friction increased rapidly during the early portion of cathodic charging and leveled off during the latter portion. Using a composite sample model (a cracked thin outer layer with a solid core), the change in modulus was found to be proportional to the quantity na/sup 3/..delta..d, where n is the crack density, a is the average crack radius and d is the depth of cracking. The kinetic behavior of both the internal friction and modulus change were found to be a two-part parallel exponential process. The rapid process was quite rapid and was found to be consistent with the initiation and growth of cracks due to the combination of hydrogen and carbon found at grain boundaries. The rapid increase in internal friction during the first process was attributed to the rapid plastic deformation from the initiation of the cracks.

  9. MC3755 Thermal Battery Lot No. 2 production summary and engineering process instruction manual

    SciTech Connect (OSTI)

    Jacobs, D.

    1989-04-27

    Production of MC3755 Thermal Battery Lot No. 2 was performed at GE Neutron Devices (GEND) in the Power Sources Development Laboratory. This report documents the results of the production build and includes an overall review of the production process, lot performance data, and the engineering process instruction manual. The overall production yield was 92%, all performance specifications were met within significant margin. 5 figs., 4 tabs.

  10. 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.

  11. 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...

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

    SciTech Connect (OSTI)

    Brochard, J.; Charras, T.

    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.

  13. Role of thermal processes in dewetting of epitaxial Ag(111) film on Si(111)

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

    Sanders, Charlotte E.; Zhang, Chendong D.; Kellogg, Gary L.; Shih, Chih-Kang

    2014-08-01

    Epitaxially grown silver (Ag) film on silicon (Si) is an optimal plasmonic device platform, but its technological utility has been limited by its tendency to dewet rapidly under ambient conditions (standard temperature and pressure). The mechanisms driving this dewetting have not heretofore been determined. In our study, scanning probe microscopy and low-energy electron microscopy are used to compare the morphological evolution of epitaxial Ag(111)/Si(111) under ambient conditions with that of similarly prepared films heated under ultra-high vacuum (UHV) conditions. Furthermore, dewetting is seen to be initiated with the formation of pinholes, which might function to relieve strain in the film.more » We find that in the UHV environment, dewetting is determined by thermal processes, and while under ambient conditions, thermal processes are not required. Finally, we conclude that dewetting in ambient conditions is triggered by some chemical process, most likely oxidation.« less

  14. Role of thermal processes in dewetting of epitaxial Ag(111) film on Si(111)

    SciTech Connect (OSTI)

    Sanders, Charlotte E.; Zhang, Chendong D.; Kellogg, Gary L.; Shih, Chih-Kang

    2014-08-01

    Epitaxially grown silver (Ag) film on silicon (Si) is an optimal plasmonic device platform, but its technological utility has been limited by its tendency to dewet rapidly under ambient conditions (standard temperature and pressure). The mechanisms driving this dewetting have not heretofore been determined. In our study, scanning probe microscopy and low-energy electron microscopy are used to compare the morphological evolution of epitaxial Ag(111)/Si(111) under ambient conditions with that of similarly prepared films heated under ultra-high vacuum (UHV) conditions. Furthermore, dewetting is seen to be initiated with the formation of pinholes, which might function to relieve strain in the film. We find that in the UHV environment, dewetting is determined by thermal processes, and while under ambient conditions, thermal processes are not required. Finally, we conclude that dewetting in ambient conditions is triggered by some chemical process, most likely oxidation.

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

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

    aluminum alloy plate to microstructure and rolling process parameters. Validate the model by predicting the stress intensity factor at onset of crack branching in hard alloys ...

  16. 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

  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. Materials Selection Considerations for Thermal Process Equipment: A BestPractices Process Heating Technical Brief

    Broader source: Energy.gov [DOE]

    This technical brief is a guide to selecting high-temperature metallic materials for use in process heating applications such as burners, electrical heating elements, material handling, load support, and heater tubes, etc.

  19. 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.

  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

  1. 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.

  2. Thermodynamic analysis of tar reforming through auto-thermal reforming process

    SciTech Connect (OSTI)

    Nurhadi, N. Diniyati, Dahlia; Efendi, M. Ade Andriansyah; Istadi, I.

    2015-12-29

    Fixed bed gasification is a simple and suitable technology for small scale power generation. One of the disadvantages of this technology is producing tar. So far, tar is not utilized yet and being waste that should be treated into a more useful product. This paper presents a thermodynamic analysis of tar conversion into gas producer through non-catalytic auto-thermal reforming technology. Tar was converted into components, C, H, O, N and S, and then reacted with oxidant such as mixture of air or pure oxygen. Thus, this reaction occurred auto-thermally and reached chemical equilibrium. The sensitivity analysis resulted that the most promising process performance occurred at flow rate of air was reached 43% of stoichiometry while temperature of process is 1100°C, the addition of pure oxygen is 40% and preheating of oxidant flow is 250°C. The yield of the most promising process performance between 11.15-11.17 kmol/h and cold gas efficiency was between 73.8-73.9%.The results of this study indicated that thermodynamically the conversion of tar into producer gas through non-catalytic auto-thermal reformingis more promising.

  3. 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.

  4. Fluidized catalytic cracking process utilizing a C3-C4 paraffin-rich co-feed and mixed catalyst system with selective reactivation of the medium pore silicate zeolite component thereof

    SciTech Connect (OSTI)

    Herbst, J.A.; Owen, H.; Schipper, P.H.

    1989-09-05

    This patent describes a catalytic cracking process featuring at least one riser reactor, at least one stripping unit and at least one regenerator. It comprises: catalytically cracking a C/sub 3/-C/sub 4/ paraffin-rich feed in the lower section of the riser wherein the catalyst in the lower section of the riser consists of a second component of a mixed catalyst system; cracking a heavy hydrocarbon feed in an upper section of the riser in the presence of both the first and second component of the mixed catalyst system; separating particles of spent first catalyst component from particles of second catalyst component in the stripping unit; stripping the separated particles of first catalyst component; conveying stripped, spent first catalyst component to the regenerator, the catalyst undergoing regeneration therein; conveying regenerated first catalyst component to the upper section of the riser; conveying stripped or non-stripped separated particles of second catalyst component to a reactivation zone, the catalyst undergoing reactivation therein; and conveying reactivated second catalyst component to the lower section of the riser.

  5. Interaction of thermo-mechanical processing parameters and stress corrosion cracking for two heats of Ni-Cr-Fe Alloy 600

    SciTech Connect (OSTI)

    Lynn, J.P.; Webb, G.L.

    1984-02-01

    The relationship between hot rolling parameters, annealing parameters, microstructures and stress corrosion cracking behavior of Ni-Cr-Fe Alloy 600 in deaerated primary plant grade water at 680{degrees}F was investigated. A high carbon (0.07%) and a medium carbon (0.04%) heat were hot rolled 20% or 80% starting at 3 different temperatures: below, near, and above the carbide solvus followed by annealing for 1 or 4 hours at a nominal temperature of 1600{degrees}F or 1900{degrees}F. Materials that are resistant to stress corrosion cracking were produced by hot rolling above the carbide solvus temperature followed by annealing at high temperatures (>1900{degrees}F). A combination of hot rolling below carbide solvus, large rolling reduction and a short annealing at a low temperature produced materials susceptible to stress corrosion cracking, especially for the high carbon heat. The resistant materials have by optical metallography as having carbide decorated grain boundaries, little intragranular carbide precipitation and good grainboundary correlation between a nital and a phosphoric acid etch. The susceptible materials as lack grain boundary carbide precipitation, have heavy intragranular carbide precipitation and lack grain boundary correlation between a nital and a phosphoric acid etch.

  6. Interaction of thermo-mechanical processing parameters and stress corrosion cracking for two heats of Ni-Cr-Fe Alloy 600

    SciTech Connect (OSTI)

    Lynn, J.P.; Webb, G.L.

    1984-02-01

    The relationship between hot rolling parameters, annealing parameters, microstructures and stress corrosion cracking behavior of Ni-Cr-Fe Alloy 600 in deaerated primary plant grade water at 680[degrees]F was investigated. A high carbon (0.07%) and a medium carbon (0.04%) heat were hot rolled 20% or 80% starting at 3 different temperatures: below, near, and above the carbide solvus followed by annealing for 1 or 4 hours at a nominal temperature of 1600[degrees]F or 1900[degrees]F. Materials that are resistant to stress corrosion cracking were produced by hot rolling above the carbide solvus temperature followed by annealing at high temperatures (>1900[degrees]F). A combination of hot rolling below carbide solvus, large rolling reduction and a short annealing at a low temperature produced materials susceptible to stress corrosion cracking, especially for the high carbon heat. The resistant materials have by optical metallography as having carbide decorated grain boundaries, little intragranular carbide precipitation and good grainboundary correlation between a nital and a phosphoric acid etch. The susceptible materials as lack grain boundary carbide precipitation, have heavy intragranular carbide precipitation and lack grain boundary correlation between a nital and a phosphoric acid etch.

  7. MC3714 Thermal Battery Lot No. 1 production summary and engineering process instruction manual

    SciTech Connect (OSTI)

    Jacobs, D.

    1990-03-01

    The MC3714 Thermal Battery provides the instrumentation power for the W82 joint test assembly (JTA). Lot No. 1 production was performed at GE Neutron Devices (GEND) by Power Sources Development Laboratory. Production started directly after the development program utilizing tooling, and processes from development. This substantially reduced preproduction activities and start up costs. Included in this report are the Engineering Process Instructions and the performance data from the build. The overall production yield was 99% and all performance requirements were met with no problems. 5 figs., 4 tabs.

  8. Substrate-dependent thermal conductivity of aluminum nitride thin-films processed at low temperature

    SciTech Connect (OSTI)

    Belkerk, B. E.; Bensalem, S.; Soussou, A.; Carette, M.; Djouadi, M. A.; Scudeller, Y.; Al Brithen, H.

    2014-12-01

    In this paper, we report on investigation concerning the substrate-dependent thermal conductivity (k) of Aluminum Nitride (AlN) thin-films processed at low temperature by reactive magnetron sputtering. The thermal conductivity of AlN films grown at low temperature (<200 °C) on single-crystal silicon (Si) and amorphous silicon nitride (SiN) with thicknesses ranging from 100 nm to 4000 nm was measured with the transient hot-strip technique. The k values for AlN films on SiN were found significantly lower than those on Silicon consistently with their microstructures revealed by X-ray diffraction, high resolution scanning electron microscopy, and transmission electron microscopy. The change in k was due to the thermal boundary resistance found to be equal to 10 × 10{sup −9} Km{sup 2}W{sup −1} on SiN against 3.5 × 10{sup −9} Km{sup 2}W{sup −1} on Si. However, the intrinsic thermal conductivity was determined with a value as high as 200 Wm{sup −1}K{sup −1} whatever the substrate.

  9. 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

  10. Energy and costs scoping study for plasma pyrolysis thermal processing system

    SciTech Connect (OSTI)

    Sherick, K.E.; Findley, J.E.

    1992-01-01

    The purpose of this study was to provide information in support of an investigation of thermal technologies as possible treatment process for buried wastes at the INEL. Material and energy balances and a cost estimate were generated for a representative plasma torch-based thermal waste treatment system operating in a pyrolysis mode. Two waste streams were selected which are representative of INEL buried wastes, large in volume, and difficult to treat by other technologies. These streams were a solidified nitrate sludge waste stream and a waste/soil mix of other buried waste components. The treatment scheme selected includes a main plasma chamber operating under pyrolyzing conditions; a plasma afterburner to provide additional residence time at high temperature to ensure complete destruction of hazardous organics; an off-gas treatment system; and a incinerator and stack to oxidize carbon monoxide to carbon dioxide and vent the clean, oxidized gases to atmosphere. The material balances generated provide materials flow and equipment duty information of sufficient accuracy to generate initial rough-order-of-magnitude (ROM) system capital and operating cost estimates for a representative plasma thermal processing system.

  11. 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; Colonomos, P

    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.

  12. LPG storage vessel cracking experience

    SciTech Connect (OSTI)

    Cantwell, J.E. )

    1988-10-01

    In order to evaluate liquefied petroleum gas (LPG) handling and storage hazards, Caltex Petroleum Corp. (Dallas) surveyed several installations for storage vessel cracking problems. Cracking was found in approximately one-third of the storage vessels. In most cases, the cracking appeared to be due to original fabrication problems and could be removed without compromising the pressure containment. Several in-service cracking problems found were due to exposure to wet hydrogen sulfide. Various procedures were tried in order to minimize the in-service cracking potential. One sphere was condemned because of extensive subsurface cracking. This article's recommendations concern minimizing cracking on new and existing LPG storage vessels.

  13. LPG storage vessel cracking experience

    SciTech Connect (OSTI)

    Cantwell, J.E.

    1988-01-01

    As part of an overall company program to evaluate LPG handling and storage hazards the authors surveyed several installations for storage vessel cracking problems. Cracking was found in approximately one third of the storage vessels. In most cases the cracking appeared due to original fabrication problems and could be removed without compromising the pressure containment. Several in-service cracking problems due to exposure to wet hydrogen sulfide were found. Various procedures were tried in order to minimize the in-service cracking potential. One sphere was condemned because of extensive subsurface cracking. Recommendations are made to minimize cracking on new and existing LPG storage vessels.

  14. Determination of crack morphology parameters from service failures for leak-rate analyses

    SciTech Connect (OSTI)

    Wilkowski, G.; Ghadiali, N.; Paul, D.

    1997-04-01

    In leak-rate analyses described in the literature, the crack morphology parameters are typically not well agreed upon by different investigators. This paper presents results on a review of crack morphology parameters determined from examination of service induced cracks. Service induced cracks were found to have a much more tortuous flow path than laboratory induced cracks due to crack branching associated with the service induced cracks. Several new parameters such as local and global surface roughnesses, as well as local and global number of turns were identified. The effect of each of these parameters are dependent on the crack-opening displacement. Additionally, the crack path is typically assumed to be straight through the pipe thickness, but the service data show that the flow path can be longer due to the crack following a fusion line, and/or the number of turns, where the number of turns in the past were included as a pressure drop term due to the turns, but not the longer flow path length. These parameters were statistically evaluated for fatigue cracks in air, corrosion-fatigue, IGSCC, and thermal fatigue cracks. A refined version of the SQUIRT leak-rate code was developed to account for these variables. Sample calculations are provided in this paper that show how the crack size can vary for a given leak rate and the statistical variation of the crack morphology parameters.

  15. 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.

  16. Thermal hydraulic feasibility assessment of the hot conditioning system and process

    SciTech Connect (OSTI)

    Heard, F.J.

    1996-10-10

    The Spent Nuclear Fuel Project was established to develop engineered solutions for the expedited removal, stabilization, and storage of spent nuclear fuel from the K Basins at the U.S. Department of Energy`s Hanford Site in Richland, Washington. A series of analyses have been completed investigating the thermal-hydraulic performance and feasibility of the proposed Hot Conditioning System and process for the Spent Nuclear Fuel Project. The analyses were performed using a series of thermal-hydraulic models that could respond to all process and safety-related issues that may arise pertaining to the Hot Conditioning System. The subject efforts focus on independently investigating, quantifying, and establishing the governing heat production and removal mechanisms, flow distributions within the multi-canister overpack, and performing process simulations for various purge gases under consideration for the Hot Conditioning System, as well as obtaining preliminary results for comparison with and verification of other analyses, and providing technology- based recommendations for consideration and incorporation into the Hot Conditioning System design bases.

  17. Thermal Analysis of the Divertor Primary Heat Transfer System Piping During the Gas Baking Process

    SciTech Connect (OSTI)

    Yoder Jr, Graydon L; Harvey, Karen; Ferrada, Juan J

    2011-02-01

    A preliminary analysis has been performed examining the temperature distribution in the Divertor Primary Heat Transfer System (PHTS) piping and the divertor itself during the gas baking process. During gas baking, it is required that the divertor reach a temperature of 350 C. Thermal losses in the piping and from the divertor itself require that the gas supply temperature be maintained above that temperature in order to ensure that all of the divertor components reach the required temperature. The analysis described in this report was conducted in order to estimate the required supply temperature from the gas heater.

  18. 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.

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

    SciTech Connect (OSTI)

    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 systems 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.

  20. Stress corrosion cracking behavior of Alloy 600 in high temperature water

    SciTech Connect (OSTI)

    Webb, G.L.; Burke, M.G.

    1995-07-01

    SCC susceptibility of Alloy 600 in deaerated water at 360 C (statically loaded U-bend specimens) is dependent on microstructure and whether the material was cold-worked and annealed (CWA) or hot-worked and annealed (HWA). All cracking was intergranular, and materials lacking grain boundary carbides were most susceptible to SCC initiation. CWA tubing materials are more susceptible to SCC initiation than HWA ring-rolled forging materials with similar microstructures (optical metallography). In CWA tubing materials, one crack dominated and grew to a visible size. HWA materials with a low hot-working finishing temperature (<925 C) and final anneals at 1010-1065 C developed both large cracks (similar to those in CWA materials) and small intergranular microcracks detectable only by destructive metallography. HWA materials with a high hot-working finishing temperature (>980 C) and a high-temperature final anneal (>1040 C), with grain boundaries that are fully decorated, developed only microcracks in all specimens. These materials did not develop large, visually detectable cracks, even after more than 300 weeks exposure. A low-temperature thermal treatment (610 C for 7h), which reduces or eliminates SCC in Alloy 600, did not eliminate microcrack formation in high temperature processed HWA materials. Conventional metallographic and analytical electron microscopy (AEM) were done on selected materials to identify the factors responsible for the observed differences in cracking behavior. Major difference between high-temperature HWA and low-temperature HWA and CWA materials was that the high temperature processing and final annealing produced predominantly ``semi-continuous`` dendritic M{sub 7}C{sub 3} carbides along grain boundaries with a minimal amount of intragranular carbides. Lower temperature processing produced intragranular M7C3 carbides, with less intergranular carbides.

  1. 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)

  2. Highly efficient electroluminescence from a solution-processable thermally activated delayed fluorescence emitter

    SciTech Connect (OSTI)

    Wada, Yoshimasa; Kubo, Shosei; Suzuki, Katsuaki; Kaji, Hironori; Shizu, Katsuyuki; Tanaka, Hiroyuki; Adachi, Chihaya

    2015-11-02

    We developed a thermally activated delayed fluorescence (TADF) emitter, 2,4,6-tris(4-(9,9-dimethylacridan-10-yl)phenyl)-1,3,5-triazine (3ACR-TRZ), suitable for use in solution-processed organic light-emitting diodes (OLEDs). When doped into 4,4′-bis(carbazol-9-yl)biphenyl (CBP) host at 16 wt. %, 3ACR-TRZ showed a high photoluminescence quantum yield of 98%. Transient photoluminescence decay measurements of the 16 wt. % 3ACR-TRZ:CBP film confirmed that 3ACR-TRZ exhibits efficient TADF with a triplet-to-light conversion efficiency of 96%. This high conversion efficiency makes 3ACR-TRZ attractive as an emitting dopant in OLEDs. Using 3ACR-TRZ as an emitter, we fabricated a solution-processed OLED exhibiting a maximum external quantum efficiency of 18.6%.

  3. 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.

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

    SciTech Connect (OSTI)

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

    1994-04-01

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

  5. Volume Comparison

    Gasoline and Diesel Fuel Update (EIA)

    Day) Process: Vacuum Distillation Thermal Cracking Thermal Cracking: Coking Thermal Cracking: Delayed Coking Thermal Cracking: Fluid Coking Thermal Cracking: Visbreaking Thermal Cracking: Other/Gas Oil Thermal Cracking: Coking (Barrels/Calendar Day) Catalytic Cracking Fresh Feed Catalytic Cracking Fresh Feed (Barrels/Calendar Day) Catalytic Cracking Recycled Feed Catalytic Hydrocracking Catalytic Hydrocracking: Distillate Catalytic Hydrocracking: Gas Oil Catalytic Hydrocracking: Residual Fuel

  6. Insights into Stress Corrosion Cracking Mechanisms from High-Resolution Measurements of Crack-Tip Structures and Compositions

    SciTech Connect (OSTI)

    Bruemmer, Stephen M.; Thomas, Larry E.

    2004-11-25

    Recent results are presented demonstrating the application of cross-sectional analytical transmission electron microscopy (ATEM) to corrosion and cracking in high-temperature, light-water-reactor (LWR) environments. Structural, compositional and crystallographic characterizations of crack-tip oxide films and interfaces at near-atomic resolutions reveal evidence for unexpected local environments, corrosion reactions and local changes in the alloy metallurgy. Information obtained by high-resolution imaging and analysis indicates the corrosion processes that occur during crack advance, and provides insights into the mechanisms controlling environmental degradation. Examples of intergranular stress-corrosion cracking (IGSCC) in Ni- and Fe-base stainless alloys are reviewed to illustrate the value of this approach. Comparisons are made between crack characteristics found in components removed from long-term LWR service and those in materials tested under well-controlled laboratory conditions. Key insights into crack corrosion environments and advance mechanisms are established for Ni-base alloy 600 in steam-generator, secondary-water environments. Solution impurities such as Pb are often found in high concentrations at leading-edge reaction zones within porous, corrosion-product films. The presence of nanometer-wide, deeply attacked grain boundaries off the main SCC cracks (without evidence for plastic deformation) is believed to indicate a major role of active-path IG corrosion in the SCC process. Similar characteristics are identified for alloy 600 cracking in primary water. This suggests that Pb may only accelerate the IG corrosion process and not alter the basic degradation mechanism. Quite different IGSCC crack and crack-tip characteristics have been discovered for Fe-base stainless steels in LWR environments. More classic SCC crack and crack-tip structures have been seen in non-sensitized materials with wall oxide films extending to the tips. Cracked components

  7. 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

  8. 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.

  9. 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 1251000?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 Mssbauer 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.

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

    DOE Patents [OSTI]

    Caneba, Gerard T. M.; Soong, David S.

    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.

  11. 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.

  12. 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.

  13. 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.

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

    SciTech Connect (OSTI)

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

    1987-01-01

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

  15. 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.

  16. 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.

  17. 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.

  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. CIRCUMFERENTIAL MFL IN-LINE INSPECTION FOR CRACKS IN PIPELINES

    SciTech Connect (OSTI)

    J.B. Nestleroth

    2003-06-01

    axially oriented volumetric defects. While successful results are presented in this report, circumferential MFL can only detect larger cracks. Even with the field aligned properly, circumferential MFL technology has difficulty detecting cracks on the outside surface that have the potential to grow to failure. Circumferential MFL can be used to detect many corrosion, mechanical damage, and crack defects. However, the detection capabilities and sizing accuracies may not be sufficient for all pipeline threats. Inspection tools that use more sophisticated technologies for detecting and sizing defects may have better performance capabilities, but will likely be expensive to operate. Circumferential MFL will be useful in identifying locations for detailed testing. While performance enhancements may be limited, circumferential MFL inspections will be part of the inspection process for many decades.

  20. Improvement of microbead cracking catalyst manufacture

    SciTech Connect (OSTI)

    Mirskii, Ya.B.; Kosolapova, A.P.; Meged, N.F.

    1986-11-01

    In order to improve the manufacturing process for KMTsR microbead catalyst for use in new cracking units, the authors consider the method of increasing the content of aluminum oxide in its amorphous part. A microbead catalyst of zeolite, containing rare-earth elements of the KMTsR type was obtained by spray-drying a slurry prepared by mechanical dispersion of hydrogel beads, with the subsequent molding and processing operations the same as in the production of bead catalyst.

  1. 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.

  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. Causes and solutions for cracking of coextruded and weld overlay floor tubes in black liquor recovery boilers

    SciTech Connect (OSTI)

    Keiser, J.R.; Taljat, B.; Wang, X.L.

    1998-09-01

    Cracking of coextruded, black liquor recovery boiler floor tubes is both a safety and an economic issue to mill operators. In an effort to determine the cause of the cracking and to identify a solution, extensive studies, described in this and three accompanying papers, are being conducted. In this paper, results of studies to characterize both the cracking and the chemical and thermal environment are reported. Based on the results described in this series of papers, a possible mechanism is presented and means to lessen the likelihood of cracking or to totally avoid cracking of floor tubes are offered.

  4. 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.

  5. Characteristics of acoustic emission during stress corrosion cracking of Inconel 600 alloy

    SciTech Connect (OSTI)

    Sung, K.Y.; Kim, I.S.; Yoon, Y.K.

    1997-10-15

    It is possible to detect by use of the acoustic emission (AE) technique the dynamic processes in stressed materials. In this study, the AE technique is applied to SCC of Inconel 600 due to depletion of chromium at grain boundaries to investigate the AE capability of detecting crack growth and to obtain the relation between AE characteristics and crack mechanisms such as fracture mode and crack growth rate during SCC. In addition, the generation of initial cracks was detected, and minimum crack size detectable with AE was determined to assess the potential of AE as a non-destructive method.

  6. Insights into Stress Corrosion Cracking Mechanisms from High-Resolution Measurements of Crack-Tip Structures and Compositions

    SciTech Connect (OSTI)

    Bruemmer, Stephen M.; Thomas, Larry E.

    2010-04-05

    The fundamental basis for mechanistic understanding and modeling of SCC remains in question for many systems. Specific mechanisms controlling SCC can vary with changes in alloy characteristics, applied/residual stress or environmental conditions. The local crack electrochemistry, crack-tip mechanics and material metallurgy are the main factors controlling crack growth. These localized properties are difficult or impossible to measure in active cracks. Nevertheless, it is essential to quantitatively interrogate these crack-tip conditions if mechanistic understanding is to be obtained. A major recent advance has been the ability to investigate SCC cracks and crack tips using high-resolution ATEM techniques. ATEM enables the characterization of SCC cracks including trapped tip solution chemistries, corrosion product/film compositions and structures, and elemental composition gradients and defect microstructures along the crack walls and at the crack tip. A wide variety of methods for imaging and analyses at resolutions down to the atomic level can be used to examine the crack and corrosion film characteristics. Surface films and reaction layers have been examined by cross-sectional TEM techniques, but little work had been conducted on environmentally induced internal cracks until that of Lewis and co-workers [1-3] and the current authors [4-17]. This capability combined with modern ATEM techniques has enabled exciting new insights into corrosion processes occurring at buried interfaces and is being used to identify mechanisms controlling IGSCC in boiling water reactor (BWR) and pressurized water reactor (PWR) components. The objective of this paper is to summarize certain results focused on IGSCC of Fe- base and Ni-base stainless alloys in high-temperature water environments. Representative crack-tip examples will be shown to illustrate specific aspects that are characteristic of SCC in the material/environment combinations. Differences and similarities in crack

  7. 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.

  8. Structures for dense, crack free thin films

    DOE Patents [OSTI]

    Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

    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.

  9. 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

  10. The effect of process parameters on the thermal conditions during moving mold ESR

    SciTech Connect (OSTI)

    Heilman, J.E.; Damkroger, B.K.

    1994-09-01

    Several experimental melts were conducted using a moving mold electroslag remelting furnace. The conditions of electrode immersion depth, slag cap thickness, and melt current were varied. Mold wall temperatures and slag pool temperatures were measured and the heat flux through the mold wall was calculated. The relationships between varying ESR melt parameters and the resultant thermal conditions were examined. The thermal profile of the mold, the heat transfer to the mold coolant total and fractional, and the formation of a slag skin were studied.

  11. Hydrogen-Induced Cracking of the Drip Shield

    SciTech Connect (OSTI)

    F. Hua

    2004-09-07

    Hydrogen-induced cracking is characterized by the decreased ductility and fracture toughness of a material due to the absorption of atomic hydrogen in the metal crystal lattice. Corrosion is the source of hydrogen generation. For the current design of the engineered barrier without backfill, hydrogen-induced cracking may be a concern because the titanium drip shield can be galvanically coupled to rock bolts (or wire mesh), which may fall onto the drip shield, thereby creating conditions for hydrogen production by electrochemical reaction. The purpose of this report is to analyze whether the drip shield will fail by hydrogen-induced cracking under repository conditions within 10,000 years after emplacement. Hydrogen-induced cracking is a scenario of premature failure of the drip shield. This report develops a realistic model to assess the form of hydrogen-induced cracking degradation of the drip shield under the hydrogen-induced cracking. The scope of this work covers the evaluation of hydrogen absorbed due to general corrosion and galvanic coupling to less noble metals (e.g., Stainless Steel Type 316 and carbon steels) under the repository conditions during the 10,000-year regulatory period after emplacement and whether the absorbed hydrogen content will exceed the critical hydrogen concentration value, above which the hydrogen-induced cracking is assumed to occur. This report also provides the basis for excluding the features, events, and processes (FEPs) related to hydrogen-induced cracking of the drip shield with particular emphasis on FEP 2.1.03.04.OB, hydride cracking of drip shields (DTN: M00407SEPFEPLA.000 [DIRS 170760]). This report is prepared according to ''Technical Work Plan (TWP) for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 169944]).

  12. 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.; 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 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

  13. 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.

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

    SciTech Connect (OSTI)

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

    2004-12-01

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

  15. Technique to eliminate helium induced weld cracking in stainless steels

    SciTech Connect (OSTI)

    Chin-An Wang; Chin, B.A.; Grossbeck, M.L.

    1992-12-31

    Experiments have shown that Type 316 stainless steel is susceptible to heat-affected-zone (HAZ) cracking upon cooling when welded using the gas tungsten arc (GTA) process under lateral constraint. The cracking has been hypothesized to be caused by stress-assisted helium bubble growth and rupture at grain boundaries. This study utilized an experimental welding setup which enabled different compressive stresses to be applied to the plates during welding. Autogenous GTA welds were produced in Type 316 stainless steel doped with 256 appm helium. The application of a compressive stress, 55 Mpa, during welding suppressed the previously observed catastrophic cracking. Detailed examinations conducted after welding showed a dramatic change in helium bubble morphology. Grain boundary bubble growth along directions parallel to the weld was suppressed. Results suggest that stress-modified welding techniques may be used to suppress or eliminate helium-induced cracking during joining of irradiated materials.

  16. 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.

  17. Cracking behavior of cored structures

    SciTech Connect (OSTI)

    Wahid, A.; Olson, D.L.; Matlock, D.K.; Kelly, T.J.

    1991-12-31

    The effects of compositional gradients, are considered based on a thermodynamic analysis, referred to as the Cahn-Hillard analysis, which describes the degree to which a local surface energy is modified by the presence of a composition gradient. The analysis predicts that both ductile and brittle fracture mechanisms are enhanced by the presence of a composition gradient. Data on stress corrosion cracking and fatigue crack growth in selected FCC alloys are used to illustrate the significance of microsegregation on mechanical properties.

  18. Cracking behavior of cored structures

    SciTech Connect (OSTI)

    Wahid, A.; Olson, D.L.; Matlock, D.K. . Center for Welding and Joining Research); Kelly, T.J. )

    1991-01-01

    The effects of compositional gradients, are considered based on a thermodynamic analysis, referred to as the Cahn-Hillard analysis, which describes the degree to which a local surface energy is modified by the presence of a composition gradient. The analysis predicts that both ductile and brittle fracture mechanisms are enhanced by the presence of a composition gradient. Data on stress corrosion cracking and fatigue crack growth in selected FCC alloys are used to illustrate the significance of microsegregation on mechanical properties.

  19. 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.

  20. Rapid processing of carbon-carbon composites by forced flow-thermal gradient chemical vapor infiltration (FCVI)

    SciTech Connect (OSTI)

    Vaidyaraman, S.; Lackey, W.J.; Agrawal, P.K.; Freeman, G.B.; Langman, M.D.

    1995-10-01

    Carbon fiber-carbon matrix composites were fabricated using the forced flow-thermal gradient chemical vapor infiltration (FCVI) process. Preforms were prepared by stacking 40 layers of plain weave carbon cloth in a graphite holder. The preforms were infiltrated using propylene, propane, and methane. The present work showed that the FCVI process is well suited for fabricating carbon-carbon composites; without optimization of the process, the authors have achieved uniform and thorough densification. Composites with porosities as low as 7% were fabricated in 8--12 h. The highest deposition rate obtained in the present study was {approximately}3 {micro}m/h which is more than an order of magnitude faster than the typical value of 0.1--0.25 {micro}m/h for the isothermal process. It was also found that the use of propylene and propane as reagents resulted in faster infiltration compared to methane.

  1. Atomistic simulations of brittle crack growth.

    SciTech Connect (OSTI)

    Hoyt, Jeffrey John

    2007-04-01

    Ceramic materials such as lead zirconium titanates (PZT), low temperature co-fired ceramics and silica glasses are used in several of Sandia's mission critical components. Brittle fracture, either during machining and processing or after many years in service, remains a serious reliability and cost issue. Despite its technological importance, brittle fracture remains poorly understand, especially the onset and propagation of sub-critical cracks. However, some insights into the onset of fracture can be gleaned from the atomic scale structure of the amorphous material. In silica for example, it is well known [1] that the Si-O-Si bonds are relatively weak and, in angle distribution functions determined from scattering experiments, the bonds exhibit a wide spread around a peak at 150. By contrast the O-Si-O bonds are strong with a narrow peak in the distribution around the 109 dictated by the SiO{sub 4} tetrahedron. In addition, slow energy release in silica, as deduced from dissolution experiments, depends on the distribution of 3-fold and higher rings in the amorphous structure. The purpose of this four month LDRD project was to investigate the atomic structure of silica in the bulk and in the vicinity of a crack tip using molecular dynamics simulations. Changes in the amorphous structure in the neighborhood of an atomically sharp tip may provide important clues as to the initiation sites and the stress intensity required to propagate a sub-critical crack.

  2. HEATING THE SOLAR ATMOSPHERE BY THE SELF-ENHANCED THERMAL WAVES CAUSED BY THE DYNAMO PROCESSES

    SciTech Connect (OSTI)

    Dumin, Yurii V. E-mail: dumin@izmiran.ru

    2012-05-20

    We discuss a possible mechanism for heating the solar atmosphere by the ensemble of thermal waves, generated by the photospheric dynamo and propagating upward with increasing magnitudes. These waves are self-sustained and amplified due to the specific dependence of the efficiency of heat release by Ohmic dissipation on the ratio of the collisional to gyrofrequencies, which in its turn is determined by the temperature profile formed in the wave. In the case of sufficiently strong driving, such a mechanism can increase the plasma temperature by a few times, i.e., it may be responsible for heating the chromosphere and the base of the transition region.

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

    DOE Patents [OSTI]

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

    2016-05-31

    The invention provides a process for forming crack-free dielectric films on a substrate. The process comprises 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. The process provides 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.

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

    SciTech Connect (OSTI)

    Leppniemi, J. Ojanper, 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}/(Vs). 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}/(Vs) and 7.5?cm{sup 2}/(Vs), 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.

  5. 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.

  6. STAC -- a new Swedish code for statistical analysis of cracks in SG-tubes

    SciTech Connect (OSTI)

    Poern, K.

    1997-02-01

    Steam generator (SG) tubes in pressurized water reactor plants are exposed to various types of degradation processes, among which stress corrosion cracking in particular has been observed. To be able to evaluate the safety importance of such cracking of SG-tubes one has to have a good and empirically founded knowledge about the scope and the size of the cracks as well as the rate of their continuous growth. The basis of experience is to a large extent constituted of the annually performed SG-inspections and crack sizing procedures. On the basis of this experience one can estimate the distribution of existing crack lengths, and modify this distribution with regard to maintenance (plugging) and the predicted rate of crack propagation. Finally, one can calculate the rupture probability of SG-tubes as a function of a given critical crack length. On account of the Swedish Nuclear Power Inspectorate an introductory study has been performed in order to get a survey of what has been done elsewhere in this field. The study resulted in a proposal of a computerizable model to be able to estimate the distribution of true cracks, to modify this distribution due to the crack growth and to compute the probability of tube rupture. The model has now been implemented in a compute code, called STAC (STatistical Analysis of Cracks). This paper is aimed to give a brief outline of the model to facilitate the understanding of the possibilities and limitations associated with the model.

  7. 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.

  8. Getter materials for cracking ammonia

    DOE Patents [OSTI]

    Boffito, Claudio; Baker, John D.

    1999-11-02

    A method is provided for cracking ammonia to produce hydrogen. The method includes the steps of passing ammonia over an ammonia-cracking catalyst which is an alloy including (1) alloys having the general formula Zr.sub.1-x Ti.sub.x M.sub.1 M.sub.2, wherein M.sub.1 and M.sub.2 are selected independently from the group consisting of Cr, Mn, Fe, Co, and Ni, and x is between about 0.0 and about 1.0 inclusive; and between about 20% and about 50% Al by weight. In another aspect, the method of the invention is used to provide methods for operating hydrogen-fueled internal combustion engines and hydrogen fuel cells. In still another aspect, the present invention provides a hydrogen-fueled internal combustion engine and a hydrogen fuel cell including the above-described ammonia-cracking catalyst.

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

    SciTech Connect (OSTI)

    Hochanadel, Patrick W; Lienert, Thomas J; Martinez, Jesse N; Martinez, Raymond J; Johnson, Matthew Q

    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.

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

    SciTech Connect (OSTI)

    Hochanadel, Patrick W; Lienert, Thomas J; Martinez, Jesse N; Johnson, Matthew Q

    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.

  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. 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.

  14. Development of reduced crude cracking catalysts

    SciTech Connect (OSTI)

    Hettinger, W.P. Jr. )

    1987-08-01

    In 1974 OPEC imposed an embargo on oil to the United States and caused a rapid rise in the price of a barrel of oil. At the time of the embargo, Ashland imported a considerable portion of its oil from the Middle East, thus raising the question of oil availability. As the problem increased in severity, Messrs. George Meyer, Oliver Zandona and Llyod Busch, began to explore alternative ways of squeezing more product from a given barrel of crude. After considering many alternatives, they arrived at the innovative thought that it might be possible to catalytically crack the 1050{degree}F plus fraction of the barrel directly to gasoline which would in effect, give them an additional volume of crude oil. Also, if vacuum fractionation were eliminated and if the entire 650{degree}F plus (reduced crude) portion of the barrel processed, this would further reduce operating costs. With these objectives and some new process innovations in mind, they began reduced crude cracking experimentation in a small 12,000 B/D FCC operating unit at Louisville. It was from these goals, concepts and a small operating unit, that the RCC process was born.

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

    DOE Patents [OSTI]

    Sun, Jiangang; Deemer, Chris

    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.

  16. 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.

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

    SciTech Connect (OSTI)

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

    2004-04-20

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

  18. 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.

  19. A low thermal impact annealing process for SiO{sub 2}-embedded Si nanocrystals with optimized interface quality

    SciTech Connect (OSTI)

    Hiller, Daniel Gutsch, Sebastian; Hartel, Andreas M.; Zacharias, Margit; Löper, Philipp; Gebel, Thoralf

    2014-04-07

    Silicon nanocrystals (Si NCs) for 3rd generation photovoltaics or optoelectronic applications can be produced by several industrially compatible physical or chemical vapor deposition technologies. A major obstacle for the integration into a fabrication process is the typical annealing to form and crystallize these Si quantum dots (QDs) which involves temperatures ≥1100  °C for 1 h. This standard annealing procedure allows for interface qualities that correspond to more than 95% dangling bond defect free Si NCs. We study the possibilities to use rapid thermal annealing (RTA) and flash lamp annealing to crystallize the Si QDs within seconds or milliseconds at high temperatures. The Si NC interface of such samples exhibits huge dangling bond defect densities which makes them inapplicable for photovoltaics or optoelectronics. However, if the RTA high temperature annealing is combined with a medium temperature inert gas post-annealing and a H{sub 2} passivation, luminescent Si NC fractions of up to 90% can be achieved with a significantly reduced thermal load. A new figure or merit, the relative dopant diffusion length, is introduced as a measure for the impact of a Si NC annealing procedure on doping profiles of device structures.

  20. Thermal and mechanical stabilization process of the organic fraction of the municipal solid waste

    SciTech Connect (OSTI)

    Giudicianni, Paola; Bozza, Pio; Sorrentino, Giancarlo; Ragucci, Raffaele

    2015-10-15

    Graphical abstract: Display Omitted - Highlights: • A domestic scale prototype for the pre-treatment of OFMSW has been tested. • Two grinding techniques are compared and thermopress is used for the drying stage. • Increasing temperature up to 170 °C reduces energy consumption of the drying stage. • In the range 5–10 bar a reduction of 97% of the initial volume is obtained. • In most cases energy recovery from the dried waste matches energy consumption. - Abstract: In the present study a thermo-mechanical treatment for the disposal of the Organic Fraction of Municipal Solid Waste (OFMSW) at apartment or condominium scale is proposed. The process presents several advantages allowing to perform a significant volume and moisture reduction of the produced waste at domestic scale thus producing a material with an increased storability and improved characteristics (e.g. calorific value) that make it available for further alternative uses. The assessment of the applicability of the proposed waste pretreatment in a new scheme of waste management system requires several research steps involving different competences and application scales. In this context, a preliminary study is needed targeting to the evaluation and minimization of the energy consumption associated to the process. To this aim, in the present paper, two configurations of a domestic appliance prototype have been presented and the effect of some operating variables has been investigated in order to select the proper configuration and the best set of operating conditions capable to minimize the duration and the energy consumption of the process. The performances of the prototype have been also tested on three model mixtures representing a possible daily domestic waste and compared with an existing commercially available appliance. The results obtained show that a daily application of the process is feasible given the short treatment time required and the energy consumption comparable to the one of

  1. 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.

  2. 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.

  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. ); Rivas, O. )

    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. 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}.

  5. 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.

  6. 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.

  7. Creep crack growth in ductile alloys

    SciTech Connect (OSTI)

    Argon, A.S.; Lau, C.W.; Ozmat, B.; Parks, D.M.

    1984-01-01

    Creep crack growth in ductile alloys involves considerable fragmentation of the crack tip region in its early phases of growth. This is a result of the defocusing action of crack tip blunting by both distortional and cavitational strains on the distribution of intergranular creep damage and is affected significantly by the initial sharpness of the crack. Specific models of intergranular damage combining non-steady creep flow, evolution and growth of grain boundary facet cracks in the inelastic deformation field leading to final fracture have been developed. When used in conjunction with finite element programs for crack tips, these damage models can explain such crack extension modes. The combination of mechanistic three dimensional damage models and large strain finite element codes, promise to be of wide-spread utility in predicting the development of creep damage under complex loading histories.

  8. 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.

  9. Saber's heavy oil cracking refinery project

    SciTech Connect (OSTI)

    Benefield, C.S.; Glasscock, W.L.

    1983-03-01

    Perhaps more than any other industry, petroleum refining has been subjected to the radical swings in business and political climates of the past several decades. Because of the huge investments and long lead times to construct refining facilities, stable government policies, predictable petroleum prices, secure feedstock supplies and markets, and reliable cost estimates are necessary ingredients to effectively plan new refinery projects. However, over the past ten years the political and economic climates have provided anything but these conditions. Yet, refiners have demonstrated a willingness to undertake risks by continuing to expand and modernize their refineries. The refining business -- just as most businesses -- responds to economic incentives. These incentives, when present, result in new technology and capacity additions. In the 1940's, significant technology advances were commercialized to refine higher-octane motor gasolines. Such processes as continuous catalytic cracking (Houdry Process Corporation), fluid catalytic cracking (Standard Oil Development Company), HF alkylation (UOP and Phillips Petroleum Company), and catalytic reforming (UOP) began to supply a growing gasoline market, generated from the war effort and the ever increasing numbers of automobiles on the road. The post-war economy of the 1950's and 1960's further escalated demand for refined products, products which had to meet higher performance specifications and be produced from a wider range of raw materials. The refining industry met the challenge by introducing hydro-processing technology, such as hydrocracking developed in 1960. But, the era must be characterized by the large crude processing capacity additions, required to meet demand from the rapidly expanding U.S. economy. In 1950, refining capacity was 6.2 million BPD. By 1970, capacity had grown to 11.9 million BPD, an increase of 91%.

  10. 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.

  11. Surrogate formulations for thermal treatment of low-level mixed waste. Part 3: Plasma hearth process testing

    SciTech Connect (OSTI)

    Chiang, J.M.; Bostick, W.D.; Hoffman, D.P.; Hermes, W.H.; Gibson, L.V. Jr.; Richmond, A.A.

    1994-01-01

    The plasma hearth process (PHP) presented in this report has been tested at a facility at Ukiah, California, in a cooperative effort between the Department of Energy (DOE), Science Applications International Corporation, Inc., and ReTech, Inc. The electrically heated plasma gas is used to destroy organic materials and bind radionuclides and Resource Conservation and Recovery Act (RCRA) metals in the glassy slag. Proof-of-principle tests were conducted successfully using nonhazardous and non-radioactive materials placed in 30-gal steel drums. On-line analyses of the gaseous effluents indicated complete combustion; emissions of CO, NO{sub x}, and particulates were low. The process also produced highly stable solid waste forms. The experiments for the next phase have been planned employing surrogates for the hazardous and radioactive components of the simulated waste streams. Natural cerium oxide is selected to simulate the behavior of radioactive actinide and transuranium elements, while natural cesium chloride is simulated for the study of relatively volatile radioactive fission products. For RCRA organics, naphthalene and 1,2-dichlorobenzene are semivolatile compounds selected to represent significant challenges to thermal destruction, whereas chlorobenzene is selected for the study of relatively volatile organics. Salts of chromium, nickel, lead, and cadmium are chosen to represent the twelve regulated toxic metals for emission and partitioning studies. The simulated waste packages presented in the text do not necessarily represent an individual waste stream within the DOE complex; rather, they were formulated to represent the most probable components in generic waste stream categories.

  12. Stress corrosion crack detection in alloy 600 in high temperature caustic. Master`s thesis

    SciTech Connect (OSTI)

    Brisson, B.W.

    1996-06-01

    Alloy 600, the material used for pressurized water reactor steam generator tubing, is susceptible to environmentally assisted stress corrosion cracking. Intergranular stress corrosion cracking (IGSCC) attacks the tubes in areas of high residual stress, and in crevice regions. No method has been successfully developed to monitor steam generator tubing in-situ for crack initiation and growth. Essentially all available published IGSCC crack growth data for alloy 600 is based on non-tubing material. Although it is very likely that the current data base is applicable to tubing processing, differences between tube and other geometries make a comparison between tubing and other data important for verification purposes. However, obtaining crack initiation and growth data from tubing is difficult due to the geometry and the thin wall thickness.

  13. Fundamental understanding and life prediction of stress corrosion cracking in BWRs and energy systems

    SciTech Connect (OSTI)

    Andresen, P.L.; Ford, F.P.

    1998-03-01

    The objective of this paper is to present an approach for design and lifetime evaluation of environmental cracking based on experimental and fundamental modeling of the underlying processes operative in crack advance. In detailed this approach and its development and quantification for energy (hot water) systems, the requirements for a life prediction methodology will be highlighted and the shortcomings of the existing design and lifetime evaluation codes reviewed. Examples are identified of its use in a variety of cracking systems, such as stainless steels, low alloy steels, nickel base alloys, and irradiation assisted stress corrosion cracking in boiling water reactor (BWR) water, as well as preliminary use for low alloy steel and Alloy 600 in pressurized water reactors (PWRs) and turbine steels in steam turbines. Identification of the common aspects with environmental cracking in other hot water systems provides a secure basis for its extension to related energy systems. 166 refs., 49 figs.

  14. Upgrading of heavy oils by asphaltenic bottom cracking

    SciTech Connect (OSTI)

    Sudoh, j.; Shiroto, Y.; Fukui, Y.; Takeuchi, C.

    1983-03-01

    Results of the pilot plant study of the conversion of heavy petroleum residues (Khafji VR) to lighter feedstocks deasphalted oil (DAO) by a combination process involving asphaltenic bottom cracking (ABC) and solvent deasphalting (SDA) are reported. In addition to correlations between DAO and asphalt yield under various hydrotreating conditions, a mathematical model describing quantitative relationships between recycle rate of SDA asphalt and ABC in extinction and recycle operations are described. Effects of process variations on product (DAO, asphalt) quality are also discussed.

  15. Prediction of reinforcement corrosion using corrosion induced cracks width in corroded reinforced concrete beams

    SciTech Connect (OSTI)

    Khan, Inamullah; François, Raoul; Castel, Arnaud

    2014-02-15

    This paper studies the evolution of reinforcement corrosion in comparison to corrosion crack width in a highly corroded reinforced concrete beam. Cracking and corrosion maps of the beam were drawn and steel reinforcement was recovered from the beam to observe the corrosion pattern and to measure the loss of mass of steel reinforcement. Maximum steel cross-section loss of the main reinforcement and average steel cross-section loss between stirrups were plotted against the crack width. The experimental results were compared with existing models proposed by Rodriguez et al., Vidal et al. and Zhang et al. Time prediction models for a given opening threshold are also compared to experimental results. Steel cross-section loss for stirrups was also measured and was plotted against the crack width. It was observed that steel cross-section loss in the stirrups had no relationship with the crack width of longitudinal corrosion cracks. -- Highlights: •Relationship between crack and corrosion of reinforcement was investigated. •Corrosion results of natural process and then corresponds to in-situ conditions. •Comparison with time predicting model is provided. •Prediction of load-bearing capacity from crack pattern was studied.

  16. 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.

  17. 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.

  18. 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.

  19. Crack growth and propagation in metallic alloys

    SciTech Connect (OSTI)

    Morrey, W.C.; Wille, L.T.

    1996-12-01

    Using large-scale molecular dynamics simulation on a massively parallel computer, the authors have studied the initiation of cracking in a Monel-like alloy of Cu-Ni. In a low temperature 2D sample, fracture from a notch starts at a little beyond 2.5% critical strain when the propagation direction is perpendicular to a cleavage plane. The authors discuss a method of characterizing crack tip position using a measure of area around the crack tip.

  20. Investigations of Low Temperature Time Dependent Cracking

    SciTech Connect (OSTI)

    Van der Sluys, W A; Robitz, E S; Young, B A; Bloom, J

    2002-09-30

    The objective of this project was to investigate metallurgical and mechanical phenomena associated with time dependent cracking of cold bent carbon steel piping at temperatures between 327 C and 360 C. Boiler piping failures have demonstrated that understanding the fundamental metallurgical and mechanical parameters controlling these failures is insufficient to eliminate it from the field. The results of the project consisted of the development of a testing methodology to reproduce low temperature time dependent cracking in laboratory specimens. This methodology was used to evaluate the cracking resistance of candidate heats in order to identify the factors that enhance cracking sensitivity. The resultant data was integrated into current available life prediction tools.

  1. Surface cracking in resistance seam welding of coated steels

    SciTech Connect (OSTI)

    Adonyi, Y.; Kimchi, M.

    1994-12-31

    In this experimental work, the focus was on the understanding the electrode-wheel/coated steel surface phenomena by building operational lobes and by correlating the weld quality with static-and dynamic-contact-resistance variation during welding. Conventional AC, DC, and electrode-wire resistance-seam weldability of printed zinc-coated and hot-dipped tin-coated steel was performed in this work, as compared with traditional lead-tin (terne) coating used as reference material. Variables included steel substrate type, welding equipment type, electrode-wheel cleaning practice, and electrode-wire geometry. Optic and electron microscopy were used for the evaluation of specimens extracted from longitudinal cross-sections of representative welds. The size and morphology of surface cracks was characterized and correlated with variations in the above-mentioned parameters. It was found that the tin-coated (unpainted) steel sheet had a superior all-together performance to the zinc-coated steel and terne-coated steel, both in terms of wider weldability lobes and lesser surface cracking. The extent of surface cracking was greatly reduced by using the electrode-wire seam welding process using a longitudinally grooved wire profile, which also widened the corresponding weldability lobes. It was also found that the extent of cracking depended on the electrode knurl geometry, substrate type, and the presence of conductive paint applied on top of the metallic coating. An attempt was made to characterize the specific mechanisms governing the LME phenomenon for the lead-, zinc and tin-based coating systems and to assess the potential for crack propagation in the welds. The dynamic contact resistance was found to be a good measure of the welding process stability and an indicator of defect formation. It was found that the ratio between the static and dynamic contact resistances of the tin-coated sheet was considerably lower than similar ratios for bare and zinc-coated sheet.

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

    SciTech Connect (OSTI)

    Tanaka, T.; Kameyama, M.; Urabe, Y.

    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.

  3. Development of crack shape: LBB methodology for cracked pipes

    SciTech Connect (OSTI)

    Moulin, D.; Chapuliot, S.; Drubay, B.

    1997-04-01

    For structures like vessels or pipes containing a fluid, the Leak-Before-Break (LBB) assessment requires to demonstrate that it is possible, during the lifetime of the component, to detect a rate of leakage due to a possible defect, the growth of which would result in a leak before-break of the component. This LBB assessment could be an important contribution to the overall structural integrity argument for many components. The aim of this paper is to review some practices used for LBB assessment and to describe how some new R & D results have been used to provide a simplified approach of fracture mechanics analysis and especially the evaluation of crack shape and size during the lifetime of the component.

  4. Formulation of cracking catalyst based on zeolite and natural clays

    SciTech Connect (OSTI)

    Aliev, R.R.; Lupina, M.I.

    1995-11-01

    Domestically manufactured cracking catalysts are based on a synthetic amorphous aluminosilicate matrix and Y zeolite. A multistage {open_quotes}gel{close_quotes} technology is used in manufacturing the catalysts. The process includes mixing solutions of sodium silicate and acidic aluminum sulfate, forming, syneresis, and activation of the beaded gel. In the manufacture of bead catalysts, the next steps in the process are washing, drying, and calcining; in the manufacture of microbead catalysts, the next steps are dispersion and formation of a hydrogel slurry, spray-drying, and calcining. The Y zeolite is either introduced into the alumina-silica sol in the stage of forming the beads, or introduced in the dispersion stage. With the aim of developing an active and selective cracking catalyst based on Y zeolite and natural clays, with improved physicomechanical properties, the authors carried out a series of studies, obtaining results that are set forth in the present article.

  5. Crack length determination by ultrasonic methods

    SciTech Connect (OSTI)

    Rehbein, D.K.; Thompson, R.B.; Buck, O.

    1992-01-01

    Under the restriction of being able to operate in through transmission with focussed transducers, it has been shown that the location of the tip of a fatigue crack can be determined to within 0.5 mm in those cases where curvature of the crack front is significant with correspondingly better accuracy as the curvature decreases. Location of the crack tip is accomplished through use of the distributed spring model and also yields information on the residual stresses due to closure. The technique used is able to determine the crack length to within [plus minus] 0.5 mm in the unloaded condition in contrast to most of the work done previously, removing the necessity for application of a load sufficient to fully open the crack.

  6. Crack length determination by ultrasonic methods

    SciTech Connect (OSTI)

    Rehbein, D.K.; Thompson, R.B.; Buck, O.

    1992-12-31

    Under the restriction of being able to operate in through transmission with focussed transducers, it has been shown that the location of the tip of a fatigue crack can be determined to within 0.5 mm in those cases where curvature of the crack front is significant with correspondingly better accuracy as the curvature decreases. Location of the crack tip is accomplished through use of the distributed spring model and also yields information on the residual stresses due to closure. The technique used is able to determine the crack length to within {plus_minus} 0.5 mm in the unloaded condition in contrast to most of the work done previously, removing the necessity for application of a load sufficient to fully open the crack.

  7. Crack shape developments and leak rates for circumferential complex-cracked pipes

    SciTech Connect (OSTI)

    Brickstad, B.; Bergman, M.

    1997-04-01

    A computerized procedure has been developed that predicts the growth of an initial circumferential surface crack through a pipe and further on to failure. The crack growth mechanism can either be fatigue or stress corrosion. Consideration is taken to complex crack shapes and for the through-wall cracks, crack opening areas and leak rates are also calculated. The procedure is based on a large number of three-dimensional finite element calculations of cracked pipes. The results from these calculations are stored in a database from which the PC-program, denoted LBBPIPE, reads all necessary information. In this paper, a sensitivity analysis is presented for cracked pipes subjected to both stress corrosion and vibration fatigue.

  8. Method for making dense crack free thin films

    DOE Patents [OSTI]

    Jacobson, Craig P.; Visco, Steven J.; De Jonghe, Lutgard C.

    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.

  9. 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.

  10. A NOVEL LOW THERMAL BUDGET THIN-FILM POLYSILICON FABRICATION PROCESS FOR LARGE-AREA, HIGH-THROUGHPUT SOLAR CELL PRODUCTION

    SciTech Connect (OSTI)

    Yue Kuo

    2010-08-15

    A novel thin-film poly-Si fabrication process has been demonstrated. This low thermal budget process transforms the single- and multi-layer amorphous silicon thin films into a poly-Si structure in one simple step over a pulsed rapid thermal annealing process with the enhancement of an ultrathin Ni layer. The complete poly-Si solar cell was fabricated in a short period of time without deteriorating the underneath glass substrate. The unique vertical crystallization process including the mechanism is discussed. Influences of the dopant type and process parameters on crystal structure will be revealed. The poly-Si film structure has been proved using TEM, XRD, Raman, and XPS methods. The poly-Si solar cell structure and the performance have been examined. In principle, the new process is potentially applicable to produce large-area thin-film poly-Si solar cells at a high throughput and low cost. A critical issue in this process is to prevent the excessive dopant diffusion during crystallization. Process parameters and the cell structure have to be optimized to achieve the production goal.

  11. Uncommon Deformation Mechanisms during Fatigue-Crack Propagation...

    Office of Scientific and Technical Information (OSTI)

    Uncommon Deformation Mechanisms during Fatigue-Crack Propagation in Nanocrystalline Alloys Prev Next Title: Uncommon Deformation Mechanisms during Fatigue-Crack Propagation ...

  12. Intergranular Strain Evolution near Fatigue Crack Tips in Polycrystall...

    Office of Scientific and Technical Information (OSTI)

    and history of the residual strain along the crack path depend on the stress multiaxiality, material properties, and history of stress intensity factor and crack growth rate. ...

  13. 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. LavesNi{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.

  14. 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

  15. MECHANICS OF CRACK BRIDGING UNDER DYNAMIC LOADS

    SciTech Connect (OSTI)

    N. SRIDHAR; ET AL

    2001-02-01

    A bridging law for fiber reinforced composites under dynamic crack propagation conditions has been derived. Inertial effects in the mechanism of fiber pullout during dynamic propagation of a bridged crack are critically examined for the first time. By reposing simple shear lag models of pullout as problems of dynamic wave propagation, the effect of the frictional coupling between the fibers and the matrix is accounted for in a fairly straightforward way. The solutions yield the time-dependent relationship between the crack opening displacement and the bridging traction. Engineering criteria and the role of material and geometrical parameters for significant inertial effects are identified.

  16. 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.

  17. Observations and insights into Pb-assisted stress corrosion cracking of alloy 600 steam generator tubes

    SciTech Connect (OSTI)

    Thomas, L.; Bruemmer, Stephen M.

    2005-08-15

    Pb-assisted stress-corrosion cracking (PbSCC) of Alloy 600 steam-generator tubing in high-temperature-water service and laboratory tests were studied by analytical transmission electron microscopy of cross-sectioned samples. Examinations of pulled tubes from many pressurized water reactors revealed lead in cracks from 11 of 17 samples. Comparisons of the degraded intergranular structures with ones produced in simple laboratory tests with PbO in near-neutral AVT water showed that the PbSCC characteristics in service tubing could be reproduced without complex chemistries and heat-flow conditions that can occur during plant operation. Observations of intergranular and transgranular cracks promoted by Pb in the test samples also provided new insights into the mechanisms of PbSCC in mill-annealed and thermally treated Alloy 600.

  18. Stress-corrosion cracking of sensitized stainless steel by sulfur-containing compounds

    SciTech Connect (OSTI)

    Isaacs, H.S.; Vyas, B.; Kendig, M.W.

    1981-01-01

    The stress corrosion cracking (SCC) of sensitized Type 304 stainless steel in thiosulfate solutions has been studied using constant extension rate tests. Very low concentrations of about 6.10/sup -7/M Na/sub 2/S/sub 2/O/sub 3/ (0.1ppm) gave cracking. With boric acid added, higher concentrations (1ppm) were required. The SCC was shown to be electrochemically controlled. Below -0.5v/sub SCE/ (-0.75/sub SHE/) no SCC took place; above this potential the rate of SCC increased with potential. An induction period was required before SCC continued above -0.5v if the potential was held at or below this value for extended times. This period was associated with the build up of an aggressive solution of thiosulfate decomposition products within the crack. The cracking process has been considered to be controlled by rupture of a salt layer and not a passivating oxide.

  19. Stress Corrosion Cracking Model for High Level Radioactive-Waste Packages

    SciTech Connect (OSTI)

    P. Andresen; G. Gordon; S. Lu

    2004-10-05

    A stress corrosion cracking (SCC) model has been adapted for performance prediction of high level radioactive-waste packages to be emplaced in the proposed Yucca Mountain repository. For waste packages of the proposed Yucca Mountain repository, the outer barrier material is the highly corrosion-resistant Alloy UNS-N06022 (Alloy 22), the environment is represented by aqueous brine films present on the surface of the waste package from dripping or deliquescence of soluble salts present in any surface deposits, and the tensile stress is principally from weld induced residual stress. SCC has historically been separated into ''initiation'' and ''propagation'' phases. Initiation of SCC will not occur on a smooth surface if the surface stress is below a threshold value defined as the threshold stress. Cracks can also initiate at and propagate from flaws (or defects) resulting from manufacturing processes (such as welding); or that develop from corrosion processes such as pitting or dissolution of inclusions. To account for crack propagation, the slip dissolution/film rupture (SDFR) model is adopted to provide mathematical formulae for prediction of the crack growth rate. Once the crack growth rate at an initiated SCC is determined, it can be used by the performance assessment to determine the time to through-wall penetration for the waste package. This paper presents the development of the SDFR crack growth rate model based on technical information in the literature as well as experimentally determined crack growth rates developed specifically for Alloy UNS-N06022 in environments relevant to high level radioactive-waste packages of the proposed Yucca Mountain radioactive-waste repository. In addition, a seismic damage related SCC crack opening area density model is briefly described.

  20. 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.

  1. Tungsten-rhenium composite tube fabricated by CVD for application in 1800/sup 0/C high thermal efficiency fuel processing furnace

    SciTech Connect (OSTI)

    Svedberg, R.C.; Bowen, W.W.; Buckman, R.W. Jr.

    1980-04-01

    Chemical Vapor Deposit (CVD) rhenium was selected as the muffle material for an 1800/sup 0/C high thermal efficiency fuel processing furnace. The muffle is exposed to high vacuum on the heater/insulation/instrumentation side and to a flowing argon-8 V/0 hydrogen gas mixture at one atmosphere pressure on the load volume side. During operation, the muffle cycles from room temperature to 1800/sup 0/C and back to room temperature once every 24 hours. Operational life is dependent on resistance to thermal fatigue during the high temperature exposure. For a prototypical furnace, the muffle is approximately 13 cm I.D. and 40 cm in length. A small (about one-half size) rhenium closed end tube overcoated with tungsten was used to evaluate the concept. The fabrication and testing of the composite tungsten-rhenium tube and prototypic rhenium muffle is described.

  2. 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.

  3. 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

  4. 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.

  5. Stress corrosion cracking of alloys 600 and 690 in all-volatile-treated water at elevated temperatures: Final report

    SciTech Connect (OSTI)

    Miglin, B.P.; Theus, G.J.

    1988-05-01

    This report describes stress corrosion (SCC) tests of Inconnel alloys 600 and 690 in all-volatile treated (AVT) water. Specimens of alloys 600 and 690 were exposed to AVT water at 288/degree/, 332/degree/, 343/degree/, and 360/degree/C. Alloy 660 generally resists SCC in high-purity water at normal sevice temperatures, but is susceptible to SCC at higher temperatures. In general, mill-annealed alloy 600 is more susceptible than high-treated material with fine lacy grain boundary carbides. Very high stresses (near or above yield) are required to induce cracking of alloy 600 in AVT or other high-purity waters. For alloy 600, 78 of 520 alloy 600 specimens eventually cracked. Although exposed for less total time than alloy 600 specimens, no alloy 690 specimens cracked. Three alloy 600 specimens cracked in the same autoclave tests in less time than those accumulated by the alloy 690 specimens. Longitudinally-oriented ID cracks became evident on alloy 690 split-tube U-bend specimens after autoclave exposures. These cracks on the 690 specimens were from three to ten times longer after exposure than similar defects found on unexposed alloy 690 specimens. The longitudinal crack lengthening on the alloy 690 split-tube U-bend specimens may have been a stress relaxation process or possibly a crack opening process of pre-existing, partially closed, longitudinal defects. Similar cracks were present in alloy 600 specimens, but in at least one case SCC did initiate from these shallow, blunt cracks.

  6. 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.

  7. Recent evaluations of crack-opening-area in circumferentially cracked pipes

    SciTech Connect (OSTI)

    Rahman, S.; Brust, F.; Ghadiali, N.; Wilkowski, G.; Miura, N.

    1997-04-01

    Leak-before-break (LBB) analyses for circumferentially cracked pipes are currently being conducted in the nuclear industry to justify elimination of pipe whip restraints and jet shields which are present because of the expected dynamic effects from pipe rupture. The application of the LBB methodology frequently requires calculation of leak rates. The leak rates depend on the crack-opening area of the through-wall crack in the pipe. In addition to LBB analyses which assume a hypothetical flaw size, there is also interest in the integrity of actual leaking cracks corresponding to current leakage detection requirements in NRC Regulatory Guide 1.45, or for assessing temporary repair of Class 2 and 3 pipes that have leaks as are being evaluated in ASME Section XI. The objectives of this study were to review, evaluate, and refine current predictive models for performing crack-opening-area analyses of circumferentially cracked pipes. The results from twenty-five full-scale pipe fracture experiments, conducted in the Degraded Piping Program, the International Piping Integrity Research Group Program, and the Short Cracks in Piping and Piping Welds Program, were used to verify the analytical models. Standard statistical analyses were performed to assess used to verify the analytical models. Standard statistical analyses were performed to assess quantitatively the accuracy of the predictive models. The evaluation also involved finite element analyses for determining the crack-opening profile often needed to perform leak-rate calculations.

  8. 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 850C 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

  9. Flaw Tolerance for Multiple Fatique Cracks

    SciTech Connect (OSTI)

    Gosselin, Stephen R.; Simonen, Fredric A.; Carter, R. G.

    2005-07-01

    This paper documents important details of the technical bases for changes to Appendix L. Calculations identified aspect ratios for equivalent single cracks (ESC) between the extremes of a 6:1 ratio and a full circumferential crack that can be used in Appendix L flaw tolerance assessments to account for the initiation, growth, and linking of multiple fatigue cracks. Probabilistic fracture mechanics (PFM) calculations determined ESC aspect ratios that result in the same through-wall crack probability as multiple small cracks (0.02 inch depth) that initiate and coalesce. The computations considered two materials (stainless and low alloy steels), three pipe diameters, five cyclic membrane-to-gradient stress ratios and a wide range of primary loads. Subsequent deterministic calculations identified the ESC aspect ratio for the hypothetical reference flaw depth assumptions in Appendix L. This paper also describes computations that compare the Appendix L flaw tolerance allowable operating period for the ESC models with results obtained when the a single default 6:1 aspect ratio reference flaw.

  10. Process for upgrading heavy petroleum feedstock

    SciTech Connect (OSTI)

    Rudnick, L.R.

    1987-02-10

    A method is described for reducing the coking tendency of a heavy hydrocarbon feedstock in a non-hydrogenative catalytic cracking process. The process comprises contacting the feedstock prior to catalytic cracking with a free radical removing catalyst comprising a transition metal napthenate at a temperature below 350/sup 0/C. for a time sufficient to reduce the free radical concentration of the feedstock whereby the coking tendency of the feedstock to the catalytic cracking process is reduced.