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Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
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1

Catalytic cracking process  

Science Conference Proceedings (OSTI)

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.

Lokhandwala, Kaaeid A. (Union City, CA); Baker, Richard W. (Palo Alto, CA)

2001-01-01T23:59:59.000Z

2

U.S. Refinery Thermal Cracking, Visbreaking Downstream Charge ...  

U.S. Energy Information Administration (EIA)

U.S. Refinery Thermal Cracking, Visbreaking Downstream Charge Capacity as of January 1 (Barrels per Stream Day)

3

Guam Refinery Thermal Cracking/Visbreaking Downstream Charge ...  

U.S. Energy Information Administration (EIA)

Guam Refinery Thermal Cracking/Visbreaking Downstream Charge Capacity as of January 1 (Barrels per Stream Day)

4

Guam Refinery Thermal Cracking/Other (including Gas Oil ...  

U.S. Energy Information Administration (EIA)

Guam Refinery Thermal Cracking/Other (including Gas Oil) Downstream Charge Capacity as of January 1 (Barrels per Stream Day)

5

U.S. Refinery Thermal Cracking, Fluid Coking Downstream Charge ...  

U.S. Energy Information Administration (EIA)

U.S. Refinery Thermal Cracking, Fluid Coking Downstream Charge Capacity as of January 1 (Barrels per Stream Day)

6

Puerto Rico Refinery Thermal Cracking/Visbreaking Downstream ...  

U.S. Energy Information Administration (EIA)

Puerto Rico Refinery Thermal Cracking/Visbreaking Downstream Charge Capacity as of January 1 (Barrels per Stream Day)

7

U.S. Refinery Thermal Cracking, Other (including Gas Oil ...  

U.S. Energy Information Administration (EIA)

U.S. Refinery Thermal Cracking, Other (including Gas Oil) Downstream Charge Capacity as of January 1 (Barrels per Stream Day)

8

Optimal control of fluid catalytic cracking processes  

Science Conference Proceedings (OSTI)

An investigation was made of the applicability of optimal control theory to the design of control systems for non-linear, multivariable chemical processes. A hypothetical fluid catalytic cracking process was selected as a typical representative of such ...

L. A. Gould; L. B. Evans; H. Kurihara

1970-09-01T23:59:59.000Z

9

Effect of Thermomechanical Processing on Fatigue Crack ...  

Science Conference Proceedings (OSTI)

gechanical driving force such as crack opening distance (COD) . However, at hold time loading, the crack growth rate is drastically decreased with an increase of ...

10

Process for magnetic beneficiating petroleum cracking catalyst  

DOE Patents (OSTI)

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.

Doctor, Richard D. (Lisle, IL)

1993-01-01T23:59:59.000Z

11

Process for magnetic beneficiating petroleum cracking catalyst  

DOE Patents (OSTI)

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.

Doctor, R.D.

1993-10-05T23:59:59.000Z

12

Thermal stress cracking and enhancement of heat extraction from fractured geothermal reservoirs  

DOE Green Energy (OSTI)

The effects of thermal stress cracking, upon heat extraction were studied. Very fundamental approximate analyses were performed to elucidate the mechanics of thermal stress cracking, and the main results are summarized.

Murphy, H.D.

1978-01-01T23:59:59.000Z

13

Process to minimize cracking of pyrolytic carbon coatings  

DOE Patents (OSTI)

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.

Lackey, Jr., Walter J. (Oak Ridge, TN); Sease, John D. (Knoxville, TN)

1978-01-01T23:59:59.000Z

14

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

E-Print Network (OSTI)

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

Shawabkeh, Reyad A.

15

A nanomechanical investigation of the crack tip process zone of marble  

E-Print Network (OSTI)

This study explores the interaction between crack initiation and nanomechanical properties in the crack tip process zone (zone of microcracking at the tip of a propagating crack) of a brittle geomaterial. Samples of Carrara ...

Brooks, Zenzile (Zenzile Z.)

2010-01-01T23:59:59.000Z

16

Cracking Condition of Cohesionless Porous Materials in Drying Processes  

E-Print Network (OSTI)

The invasion of air into porous systems in drying processes is often localized in soft materials, such as colloidal suspensions and granular pastes, and it typically develops in the form of cracks before ordinary drying begins. To investigate such processes, we construct an invasion percolation model on a deformable lattice for cohesionless elastic systems, and with this model we derive the condition under which cracking occurs. A Griffith-like condition characterized by a dimensionless parameter is proposed, and its validity is checked numerically. This condition indicates that the ease with which cracking occurs increases as the particles composing the material become smaller, as the rigidity of the system increases, and as the degree of heterogeneity characterizing the drying processes decreases.

So Kitsunezaki

2013-01-15T23:59:59.000Z

17

Subcritical Crack Growth Processes in SiC/SiC Ceramic Matrix Composites  

Science Conference Proceedings (OSTI)

Ceramic matrix composites have the potential to operate at high-temperatures and are, therefore being considered for a variety of advanced energy technologies such as combustor liners in land based gas turbo/generators, heat exchangers and advanced fission and fusion reactors. Ceramic matrix composites exhibit a range of crack growth mechanisms driven by a range of environmental and nuclear conditions. The crack growth mechanisms include: 1) fiber relaxation by thermal (FR) and irradiation (FIR) processes, 2) fiber stress-rupture (SR), 3) interface removal (IR) by oxidation, and 4) oxidation embrittlement (OE) resulting from glass formation including effects of glass viscosity. Analysis of these crack growth processes has been accomplished with a combination experimental/modeling effort. Dynamic, high-temperature, in situ crack growth measurements have been made in variable Ar + O2 environments while a PNNL developed model has been used to extrapolate this data and to add radiation effects. In addition to the modeling effort, a map showing these mechanisms as a function of environmental parameters was developed. This mechanism map is an effective tool for identifying operating regimes and predicting behavior. The process used to develop the crack growth mechanism map was to: 1) hypothesize and experimentally verify the operative mechanisms, 2) develop an analytical model for each mechanism, and 3) define the operating regime and boundary conditions for each mechanism. A map for SiC/SiC composites has been developed for chemical and nuclear environments as a function of temperature and time.

Jones, Russell H.; Henager, Charles H.

2005-07-01T23:59:59.000Z

18

Thermal Cracking of Large-Diameter 706 Ingots  

Science Conference Proceedings (OSTI)

responsible for the cracking. The most plausible scenario is that residual stresses generated by ... Analysis of Heat Up for Homogenization. Finite Element Model.

19

Effect of Thermal-Mechanical Treatment on the Fatigue Crack ...  

Science Conference Proceedings (OSTI)

that fatigue crack propagation (FCP) resistance without holding time has no significant difference between three alloys with 718Plus being the best and 718 the ...

20

Engineering methods for predicting productivity and longevity of hot-dry-rock geothermal reservoir in the presence of thermal cracks. Technical completion report  

DOE Green Energy (OSTI)

Additional heat extraction from geothermal energy reservioirs depends on the feasibility to extend the main, hydraulic fracture through secondary thermal cracks of the adjacent hot rock. When the main, hydraulic fracture is cooled sufficiently, these secondary thermal cracks are produced normal to the main fracture surface. As such, both the heat transfer surface area and heat energy available to the fluid circulating through the main, hydraulic fracture system increase. Methods for predicting the productivity and longevity of a geothermal reservoir were developed. A question is whether a significant long-term enhancement of the heat extraction process is achieved due to these secondary thermal cracks. In short, the objectives of this investigation are to study how the main, hydraulic fracture can be extended through these secondary thermal cracks of the rock, and to develop methods for predicting the productivity and longevity of a geothermal reservoir.

Hsu, Y.C.; Lu, Y.M.; Ju, F.D.; Dhingra, K.C.; Lu, Y.M.; Ju, F.D.; Dhingra, K.C.

1978-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Thermal stress cracking and the enhancement of heat extraction from fractured geothermal reservoirs  

DOE Green Energy (OSTI)

Given sufficient time, the extraction of heat from geothermal reservoirs formed by the hydraulic fracturing of competent rock will eventually result in the formation of thermal stress cracks in the reservoir. These cracks penetrate the rock in a manner such that the penetration-to-spacing ratio is approximately one. The penetration depends upon the extent of cooling and the square root of time. Initially then, the cracks are closely spaced and penetrate but little, so that a crazing pattern is apparent; but with increasing time some of these cracks, now more widely spaced, grow deeper. Eventually these larger cracks attain a critical aperture such that significant rates of water flow can be established within them and thus the newly created heat transfer area becomes useful for heat extraction. At the same time that cracks are forming within the main reservoir, thermal cracking also occurs in the wellbores that communicate with the reservoir. These cracks eventually convey water to and from the reservoir, thus leading to a decrease in the flow impedances that are often concentrated in the wellbore regions.

Murphy, H.D.

1978-04-01T23:59:59.000Z

22

Rapid thermal processing by stamping  

DOE Patents (OSTI)

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.

Stradins, Pauls; Wang, Qi

2013-03-05T23:59:59.000Z

23

Thermal Conversion Process (TCP) Technology  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Changing World Technologies' Changing World Technologies' Thermal Conversion Process Commercial Demonstration Plant DOE/EA 1506 Weld County, Colorado December 2004 U.S. DEPARTMENT OF ENERGY GOLDEN FIELD OFFICE 1617 Cole Boulevard Golden, Colorado 80401 Thermal Conversion Process (TCP) Technology Commercial Demonstration - Weld County, CO TABLE OF CONTENTS Environmental Assessment Thermal Conversion Process (TCP) Technology Commercial Demonstration Project Weld County, Colorado SUMMARY............................................................................................................................. S-1 1.0 INTRODUCTION.........................................................................................................1-1 1.1. National Environmental Policy Act and Related Procedures...........................1-1

24

Enhanced heat extraction from hot-dry-rock geothermal reservoirs due to interacting secondary thermal cracks. Final report  

DOE Green Energy (OSTI)

How the fluid circulating through the main hydraulic fracture and the thermally-induced secondary, growing, interacting cracks affects the time-varying temperature, deformations, stresses, thermal crack geometry, water flow rates through the main and thermal cracks, reservoir coolant outlet temperature, and reservoir thermal power of the cracked geothermal reservoir is investigated. First, a simplified version of the proposed hot-dry-rock reservoir is considered. A closed-form solution of the rock temperature without thermal crack was found and substituted into SAP-IV computer code to calculate the stresses. These stresses being superposed with earth stresses and fluid pressure were used in conjunction with the fracture mechanics criterion to determine the initiation of secondary thermal crack. After the initiation of secondary thermal crack, the rock temperature was then calculated by a two-dimensional heat conduction program AYER. The detailed procedures for carrying out these steps are listed. Solutions developed are applied to studying the time-varying temperature field, thermal stresses and crack geometry produced, and additional heat power generated in the reservoir. Conclusions were discussed and summarized. (MHR)

Hsu, Y.C.

1979-04-01T23:59:59.000Z

25

Solar Thermal Process Heat | Open Energy Information  

Open Energy Info (EERE)

Process Heat Jump to: navigation, search TODO: Add description List of Solar Thermal Process Heat Incentives Retrieved from "http:en.openei.orgwindex.php?titleSolarThermalPr...

26

A computational study of the time dependent crack growth process  

SciTech Connect

Universal studies of creep crack growth for (1) constant load and (2) variable load cases are presented. Results of the constant load cases is compared to experiment. The behavior of displacements and integral creep for fracture parameters are discussed for both load cases. The need for using a constitutive law which can handle cyclic creep is discussed.

Brust, F.W.; Krishnaswamy, P.

1992-01-01T23:59:59.000Z

27

LABORATORY VI ENERGY AND THERMAL PROCESSES  

E-Print Network (OSTI)

LABORATORY VI ENERGY AND THERMAL PROCESSES Lab VI - 1 The change of the internal energy of a system temperature by sweating to cool down. Running seems to be the conversion of chemical energy to thermal energy energy into thermal energy, you decide to make some measurements in the laboratory. To make

Minnesota, University of

28

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

Science Conference Proceedings (OSTI)

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.

Venkateswara Rao, K.T.; Ritchie, R.O. (Lawrence Berkeley Lab., CA (United States)); Kim, N.J. (Pohang Inst. of Science and Technology (Korea, Republic of)); Pizzo, P.P. (San Jose State Univ., CA (United States))

1990-04-01T23:59:59.000Z

29

Modeling the cracking process of rocks from continuity to discontinuity using a cellular automaton  

Science Conference Proceedings (OSTI)

A rock discontinuous cellular automaton (RDCA) was developed for modeling rock fracturing processes from continuous to discontinuous deformation under mechanical loading. RDCA is an integration of the following basic concepts: (1) representation of heterogeneity ... Keywords: Cracking process, Discontinuity, Elasto-plastic cellular automaton, Level set, Partition of unity, Rock discontinuous cellular automaton

Peng-Zhi Pan; Fei Yan; Xia-Ting Feng

2012-05-01T23:59:59.000Z

30

Catalytic Cracking Downstream Processing of Fresh Feed Input  

U.S. Energy Information Administration (EIA)

Process: Period-Unit: Download Series History: Definitions, Sources & Notes: Show Data By: Process: Area: Mar-13 Apr-13 May-13 Jun-13 Jul-13 Aug-13 View History; U.S ...

31

Crack growth behavior of encapsulation processed SiC-PMMA particulate composites  

Science Conference Proceedings (OSTI)

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.

Sheu, C.H.

1990-05-01T23:59:59.000Z

32

ALTERNATIVE THERMAL DESTRUCTION PROCESSES FOR HAZARDOUS WASTES  

E-Print Network (OSTI)

·Product Gas 400 2,000 11,300 Natural Gas 15,900 57,700 11,300 Most of these boilers are very small natural gas Distillate oil Natural gas Residual oil Distillate oil Natural gas Bituminous coal Bituminous coal Percent regulations. Candidate thermal processes include industrial processes such as boilers, process heaters, cement

Columbia University

33

Imprinting the memory into paste and its visualization as crack patterns in drying process  

E-Print Network (OSTI)

In the drying process of paste, we can imprint into the paste the order how it should be broken in the future. That is, if we vibrate the paste before it is dried, it remembers the direction of the initial external vibration, and the morphology of resultant crack patterns is determined solely by the memory of the direction. The morphological phase diagram of crack patterns and the rheological measurement of the paste show that this memory effect is induced by the plasticity of paste.

Akio Nakahara; Yousuke Matsuo

2005-01-19T23:59:59.000Z

34

Coupled Thermal-Hydrological-Mechanical Processes in Salt, Hot...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Coupled Thermal-Hydrological-Mechanical Processes in Salt, Hot Granular Salt Consolidation, Constitutive Model and Micromechanics Coupled Thermal-Hydrological-Mechanical Processes...

35

Thermal plasma processing of materials  

SciTech Connect

Emphasis has been on plasma synthesis of fine powders, plasma Chemical Vapor Deposition (CVD), on related diagnostics, and on modeling work. Since plasma synthesis as well as plasma CVD make frequent use of plasma jets, the beginning has been devoted of plasma jets and behavior of particulates injected into such plasma jets. Although most of the construction of the Triple-Torch Plasma Reactor (TTPR) has already been done, modifications have been made in particular modifications required for plasma CVD of diamond. A new reactor designed for Counter-Flow Liquid Injection Plasma Synthesis (CFLIPS) proved to be an excellent tool for synthesis of fine powders as well as for plasma CVD. An attempt was made to model flow and temperature fields in this reactor. Substantial efforts were made to single out those parameters which govern particle size, size distribution, and powder quality in our plasma synthesis experiments. This knowledge is crucial for controlling the process and for meaningful diagnostics and modeling work. Plasma CVD of diamond films using both reactors has been very successful and we have been approached by a number of companies interested in using this technology for coating of tools.

Pfender, E.; Heberlein, J.

1992-02-01T23:59:59.000Z

36

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

E-Print Network (OSTI)

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

Hixon, Jeff

2006-01-01T23:59:59.000Z

37

Value of solar thermal industrial process heat  

DOE Green Energy (OSTI)

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.

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

1986-03-01T23:59:59.000Z

38

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

Science Conference Proceedings (OSTI)

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.

Hall, M.M. Jr.

1993-10-01T23:59:59.000Z

39

Thermal integration of processes to recover helium  

SciTech Connect

New applications for helium have resulted in significant growth in helium demand in recent years. The primary source of helium in the USA is natural gas reservoirs. Typically natural gas reservoirs that contain helium also contain nitrogen. The presence of nitrogen requires that the heating value of the gas be upgraded using nitrogen rejection units (NRU). Thermal integration of the NRU process with the helium recovery process is described. Further integration of NRU and helium recovery process to produce cold helium gas suitable for use as a feed to a helium liquefier is also described. A key aspect of the integrated process is the use of refrigeration from the NRU to reduce power requirements, and capital cost for the helium recovery process.

Pahade, R.F.; Maloney, J.J.; Fisher, T.F. (Union Carbide Corp., Linde Div., Tonawanda, NY (US))

1988-01-01T23:59:59.000Z

40

Simulation and design of solar thermal processes  

DOE Green Energy (OSTI)

Methods of simulation and design of solar thermal processes have been developed and used in process system studies. During the period of this contract, new process component model formulations have been developed, including: transient LiBr--H/sub 2/O absorption cooler; CPC and other ''advanced'' collectors; and windows, storage wall and shading devices for passive solar heating. Systems studies have included: parallel and series solar/heat pump combinations; phase change storage in solar heating; absorption cooling with and without cooler transients. The general solar process simulation program, TRNSYS, has been further developed, documented, distributed and supported. Design procedure studies have led to development of a method for calculating the phi, the average solar radiation availability, and the development of the phi, f-chart method for design of closed-loop solar heating systems which (a) can have load temperatures other than 20/sup 0/C, and (b) have approximately constant COP of any energy converters between storage and load.

Not Available

1978-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Materials Reliability Program: Computer-Based NDE Training for Thermal Fatigue Cracking (MRP-36, Revision 2)  

Science Conference Proceedings (OSTI)

This product comes packaged together and contains both #1022875, Materials Reliability Program: NDE Technology for Detection of Thermal Fatigue Damage in Piping, (MRP-23, Revision 1) and Product #1024915, Computer-Based NDE Training for Thermal ...

2012-11-20T23:59:59.000Z

42

Synthesis report on thermally driven coupled processes  

SciTech Connect

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 material documenting the conceptual and mathematical basis for modeling coupled phenomena. The actual models and codes, and their specific empirical and theoretical bases, will be documented in a separate report to be delivered in FY99.

Hardin, E.L.

1997-10-15T23:59:59.000Z

43

The evolution of solid density within a thermal explosion II. Dynamic proton radiography of cracking and solid consumption by burning  

Science Conference Proceedings (OSTI)

We report proton transmission images obtained subsequent to the laser assisted thermal ignition of a sample of PBX 9501 (a plastic bonded formulation of the explosive nitramine octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)). We describe the laser assisted thermal ignition technique as a means to synchronize a non-linear thermal ignition event while preserving the subsequent post-ignition behavior. We have obtained dynamic proton transmission images at two spatial magnifications and viewed both the radial and transverse axis of a solid cylindrical sample encased in aluminum. Images have been obtained with 3 to 15 {mu}s temporal resolution and approximately 100 {mu}m spatial resolution at the higher magnification. We observe case expansion from very early in the experiment, until case fragmentation. We observe spatially anisotropic features in the transmission which we attribute to cracking in the solid explosive, in agreement with previous measurements conducted on two dimensional samples with optical viewing. Digital analysis of the images also reveals spatially isotropic features which we attribute to the evolution of the loss of density by burning subsequent to thermal ignition.

Smilowitz, L.; Henson, B. F.; Romero, J. J.; Asay, B. W.; Saunders, A.; Merrill, F. E.; Morris, C. L.; Kwiatkowski, K.; Grim, G.; Mariam, F.; Schwartz, C. L.; Hogan, G.; Nedrow, P.; Murray, M. M.; Thompson, T. N.; Espinoza, C.; Lewis, D.; Bainbridge, J.; McNeil, W.; Rightley, P. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); and others

2012-05-15T23:59:59.000Z

44

Simulation and design of solar thermal processes  

SciTech Connect

Methods of simulation and design of solar thermal processes have been developed and used in process system studies. During the period of this contract, new process component model formulations have been developed, including: transient LiBr--H/sub 2/O absorption cooler; CPC and other ''advanced'' collectors; and windows, storage wall and shading devices for passive solar heating. Systems studies have included: parallel and series solar/heat pump combinations; phase change storage in solar heating; absorption cooling with and without cooler transients. The general solar process simulation program, TRNSYS, has been further developed, documented, distributed and supported. Design procedure studies have led to development of a method for calculating the phi, the average solar radiation availability, and the development of the phi, f-chart method for design of closed-loop solar heating systems which (a) can have load temperatures other than 20/sup 0/C, and (b) have approximately constant COP of any energy converters between storage and load.

1978-12-01T23:59:59.000Z

45

Thermal processes for heavy oil recovery  

Science Conference Proceedings (OSTI)

This status report summarizes the project BE11B (Thermal Processes for Heavy Oil Recovery) research activities conducted in FY93 and completes milestone 7 of this project. A major portion of project research during FY93 was concentrated on modeling and reservoir studies to determine the applicability of steam injection oil recovery techniques in Texas Gulf Coast heavy oil reservoirs. In addition, an in-depth evaluation of a steamflood predictive model developed by Mobil Exploration and Production Co. (Mobil E&P) was performed. Details of these two studies are presented. A topical report (NIPER-675) assessing the NIPER Thermal EOR Research Program over the past 10 years was also written during this fiscal year and delivered to DOE. Results of the Gulf Coast heavy oil reservoir simulation studies indicated that though these reservoirs can be successfully steamflooded and could recover more than 50% of oil-in-place, steamflooding may not be economical at current heavy oil prices. Assessment of Mobil E&P`s steamflood predictive model capabilities indicate that the model in its present form gives reasonably good predictions of California steam projects, but fails to predict adequately the performance of non-California steam projects.

Sarkar, A.K.; Sarathi, P.S.

1993-11-01T23:59:59.000Z

46

Thermal storage material and process for making  

SciTech Connect

A thermal storage structure and process for making the same comprises a base material of a substantially open cell structure, with the pores interconnected and open to the surface. The open cell structure may be a volcanic rock or alternatively may be a synthetically made structure such as foamed glass, foamed concrete or foamed metal. The open cell material is completely saturated with a latent heat storage component such as a salthydrate or eutectic salts. In the process of making the latent heat storage structure, the latent heat storage component is melted in a container and the open cell structure is placed therein, whereupon the melt is spontaneously imbibed by the structure, replacing the air in the open cell structure with the liquid latent heat storage component. The structure, after cooling, is packaged or encapsulated with a vapor impermeable material. In a preferred embodiment of foamed glass material, the structure is sealed in an aluminum foil, and in an alternative embodiment, the foamed aluminum material is sealed with an aluminum foil.

Boardman, B.J.

1981-05-19T23:59:59.000Z

47

List of Solar Thermal Process Heat Incentives | Open Energy Information  

Open Energy Info (EERE)

Process Heat Incentives Process Heat Incentives Jump to: navigation, search The following contains the list of 204 Solar Thermal Process Heat Incentives. CSV (rows 1 - 204) Incentive Incentive Type Place Applicable Sector Eligible Technologies Active 30% Business Tax Credit for Solar (Vermont) Corporate Tax Credit Vermont Commercial Industrial Photovoltaics Solar Space Heat Solar Thermal Electric Solar Thermal Process Heat Solar Water Heat No APS - Renewable Energy Incentive Program (Arizona) Utility Rebate Program Arizona Commercial Residential Anaerobic Digestion Biomass Daylighting Geothermal Electric Ground Source Heat Pumps Landfill Gas Other Distributed Generation Technologies Photovoltaics Small Hydroelectric Solar Pool Heating Solar Space Heat Solar Thermal Process Heat

48

Thermal Stability of Al 5356 Processed by Cryomilling and Spark ...  

Science Conference Proceedings (OSTI)

... Thermal Stability of Al 5356 Processed by Cryomilling and Spark Plasma Sintering ... Ordered Complexions: The Structure and Energy of Ni-Al2O3 Interfaces.

49

Pulse Thermal Processing of Functional Materials Using a ...  

Ronald D. Ott, Craig A. Blue, Nancy J. Dudney, and David C. Harper, Pulse Thermal Processing of Functional Materials Using Directed Plasma Arc, U.S.

50

Developing Thermal Processes with Energy Efficiency in Mind  

Science Conference Proceedings (OSTI)

Opportunities to conserve energy not only reduce ecological impact, but can result in significant cost saving, as thermal processing is a critical cost driver in ...

51

Acoustic emission from thermal-gradient cracks in UO$sub 2$  

SciTech Connect

A feasibility study has been conducted to evaluate the potential use of acoustic emission to monitor thermal-shock damage in direct electrical heating of UO$sub 2$ pellets. In the apparatus used for the present tests, two acoustic- emission sensors were placed on extensions of the upper and lower electrical feedthroughs. Commercially available equipment was used to accumulate acoustic- emission data. The accumulation of events displayed on a cathode-ray-tube screen indicates the total number of acoustic-emission events at a particular location within the pellet stack. These tests have indicated that acoustic emission can be used to monitor thermal-shock damage in UO$sub 2$ pellets subjected to direct- electrical heating. 8 references. (auth)

Kennedy, C.R.; Kupperman, D.S.; Wrona, B.J.

1975-01-01T23:59:59.000Z

52

Pulse thermal processing of functional materials using directed plasma arc  

DOE Patents (OSTI)

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.

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

2007-05-22T23:59:59.000Z

53

Thermal processing system concepts and considerations for RWMC buried waste  

SciTech Connect

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.

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

1992-02-01T23:59:59.000Z

54

Process and apparatus for thermal enhancement  

DOE Patents (OSTI)

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.

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

1984-06-26T23:59:59.000Z

55

Quench Cracking Characterization of Superalloys Using Fracture ...  

Science Conference Proceedings (OSTI)

When the on-cooling thermal stress. (load) accumulated to a certain point, quench cracking happened abruptly. Based on the precrack length, the thermal stress ...

56

Conductive Thermal Interaction in Evaporative Cooling Process  

E-Print Network (OSTI)

It has long been recognized that evaporative cooling is an effective and logical substitute for mechanical cooling in hot-arid climates. This paper explores the application of evaporative coolers to the hot-humid climates using a controlled temperature of the incoming water. With exploitation of the effect of the thermal conduction between cool underground water and entering air, the performance of an evaporative cooler can be enhanced and its use in hot and moderately humid climates should also be considered. Usually the dry-bulb depression performed by an evaporative cooler depends solely on the ambient wet-bulb temperature. The cool underground water in an evaporative cooler can cause not only adiabatic evaporation but also sensible heat transfer between water and entering air for thermal comfort. This hybrid system outperforms the two-stage evaporative cooler without employing a complicated heat exchanger (indirect system), if the temperature of underground water is lower than the ambient wet-bulb temperature. Several areas in the southern hot-humid parts of the U.S. meet this condition.

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

1990-01-01T23:59:59.000Z

57

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

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.

Sullivan, Edmund J.; Anderson, Michael T.

2013-01-01T23:59:59.000Z

58

Integrating Broad-Band High-Fidelity Acoustic Emission Sensors and Array Processing to Study Drying Shrinkage Cracking in Concrete  

E-Print Network (OSTI)

, cracks can create stress concentrations which can cause further cracking at loads which are well under energy released from the formation of a crack is converted into stress waves which in turn produce Shrinkage Cracking in Concrete Gregory C. McLaskeya,1 , Steven D. Glasera , Christian U. Grosseb

Glaser, Steven D.

59

Thermal Systems Process and Components Laboratory (Fact Sheet)  

DOE Green Energy (OSTI)

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.

Not Available

2011-10-01T23:59:59.000Z

60

Technical resource document for assured thermal processing of wastes  

Science Conference Proceedings (OSTI)

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.

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

1994-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Thermal Insulation Performance in the Process Industries: Facts and Fallacies  

E-Print Network (OSTI)

The efficient use of thermal insulation materials and systems for design of cryogenic and elevated temperature process applications depends upon a reliable knowledge of their properties. Properties determined under idealized laboratory conditions are inadequate based on quantified field performance results. The various general and specific materials and environment factors which influence actual thermal performance will be outlined and discussed. Examples are given to illustrate the significant effects that such factors can have on energy conservation in the industrial arena. Various solutions are suggested.

Tye, R. P.

1985-05-01T23:59:59.000Z

62

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

SciTech Connect

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.

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

2007-08-20T23:59:59.000Z

63

Coupled Thermal-Hydrological-Mechanical Processes in Salt, Hot Granular  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Coupled Thermal-Hydrological-Mechanical Processes in Salt, Hot Coupled Thermal-Hydrological-Mechanical Processes in Salt, Hot Granular Salt Consolidation, Constitutive Model and Micromechanics Coupled Thermal-Hydrological-Mechanical Processes in Salt, Hot Granular Salt Consolidation, Constitutive Model and Micromechanics The report addresses granular salt reconsolidation from three vantage points: laboratory testing, modeling, and petrofabrics. The experimental data 1) provide greater insight and understanding into the role of elevated temperature and pressure regimes on physical properties of reconsolidated crushed salt, 2) can supplement an existing database used to develop a reconsolidation constitutive model and 3) provide data for model evaluation. The constitutive model accounts for the effects of moisture through pressure solution and dislocation creep, with both terms dependent

64

Coupled Thermal-Hydrological-Mechanical Processes in Salt, Hot Granular  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Coupled Thermal-Hydrological-Mechanical Processes in Salt, Hot Coupled Thermal-Hydrological-Mechanical Processes in Salt, Hot Granular Salt Consolidation, Constitutive Model and Micromechanics Coupled Thermal-Hydrological-Mechanical Processes in Salt, Hot Granular Salt Consolidation, Constitutive Model and Micromechanics The report addresses granular salt reconsolidation from three vantage points: laboratory testing, modeling, and petrofabrics. The experimental data 1) provide greater insight and understanding into the role of elevated temperature and pressure regimes on physical properties of reconsolidated crushed salt, 2) can supplement an existing database used to develop a reconsolidation constitutive model and 3) provide data for model evaluation. The constitutive model accounts for the effects of moisture through pressure solution and dislocation creep, with both terms dependent

65

Process management using component thermal-hydraulic function classes  

DOE Patents (OSTI)

A process management expert system for a nuclear, chemical or other process is effective 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. The search process is based upon mass, momentum and energy conservation principles so that qualitative thermal-hydraulic fundamental principles are satisfied for new system configurations. 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.

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

1997-12-01T23:59:59.000Z

66

Process management using component thermal-hydraulic function classes  

DOE Patents (OSTI)

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.

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

1999-01-01T23:59:59.000Z

67

Process management using component thermal-hydraulic function classes  

DOE Patents (OSTI)

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.

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

1999-07-27T23:59:59.000Z

68

Thermal acidization and recovery process for recovering viscous petroleum  

DOE Patents (OSTI)

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.

Poston, Robert S. (Winter Park, FL)

1984-01-01T23:59:59.000Z

69

Prediction of Reflection Cracking in Hot Mix Asphalt Overlays  

E-Print Network (OSTI)

Reflection cracking is one of the main distresses in hot-mix asphalt (HMA) overlays. It has been a serious concern since early in the 20th century. Since then, several models have been developed to predict the extent and severity of reflection cracking in HMA overlays. However, only limited research has been performed to evaluate and calibrate these models. In this dissertation, mechanistic-based models are calibrated to field data of over 400 overlay test sections to produce a design process for predicting reflection cracks. Three cracking mechanisms: bending, shearing traffic stresses, and thermal stress are taken into account to evaluate the rate of growth of the three increasing levels of distress severity: low, medium, and high. The cumulative damage done by all three cracking mechanisms is used to predict the number of days for the reflection crack to reach the surface of the overlay. The result of this calculation is calibrated to the observed field data (severity and extent) which has been fitted with an S-shaped curve. In the mechanistic computations, material properties and fracture-related stress intensity factors are generated using efficient Artificial Neural Network (ANN) algorithms. In the bending and shearing traffic stress models, the traffic was represented by axle load spectra. In the thermal stress model, a recently developed temperature model was used to predict the temperature at the crack tips. This process was developed to analyze various overlay structures. HMA overlays over either asphalt pavement or jointed concrete pavement in all four major climatic zones are discussed in this dissertation. The results of this calculated mechanistic approach showed its ability to efficiently reproduce field observations of the growth, extent, and severity of reflection cracking. The most important contribution to crack growth was found to be thermal stress. The computer running time for a twenty-year prediction of a typical overlay was between one and four minutes.

Tsai, Fang-Ling

2010-12-01T23:59:59.000Z

70

Method and apparatus for thermal processing of semiconductor substrates  

DOE Patents (OSTI)

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.

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

2000-01-01T23:59:59.000Z

71

Unvented thermal process for treatment of hazardous and mixed wastes  

Science Conference Proceedings (OSTI)

An Unvented Thermal Process is being developed that does not release gases during the thermal treatment operation. The main unit in the process is a fluidized-bed processor containing a bed of calcined limestone (CaO), which reacts with gases given off during oxidation of organic materials. Gases that will react with CaO include CO{sub 2}, SO{sub 2}, HCI, HBr, and other acid gases. Water vapor formed during the oxidation process is carried off with the fluidizing gas and is removed in a condenser. Oxygen is added to the remaining gas (mainly nitrogen), which is recirculated to the oxidizer. The most flexible arrangement of equipment involves separating the processor into two units: An oxidizer, which may be any of a variety of types including standard incinerators, and a carbon dioxide sorber.

Nelson, P.A.; Swift, W.M.

1993-09-01T23:59:59.000Z

72

Supporting technology for enhanced oil recovery - EOR thermal processes  

SciTech Connect

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.

NONE

1995-03-01T23:59:59.000Z

73

Shale oil cracking. 1. Kinetics  

DOE Green Energy (OSTI)

Experiments were conducted to determine kinetics for thermal cracking of shale oil vapor over shale. Cracking temperatures of 504 to 610/sup 0/C and residence times of 2 to 11 seconds were used. A first-order Arrhenius rate expression and stoichiometry were obtained. Also observed were changes in the oil quality. Cracking decreased the H/C ratio, increased the nitrogen content, and decreased the pour point of the oil. Gas-phase oil cracking is contrasted to liquid-phase oil coking as a loss mechanism in oil-shale retorting.

Burnham, A.K.; Taylor, J.R.

1979-10-01T23:59:59.000Z

74

PICEP: Pipe Crack Evaluation Program  

Science Conference Proceedings (OSTI)

We describe a computer program that calculates the crack-opening area, the critical (stable) crack length and the two-phase flow rate through cracks in ductile stainless steel pipes and steam generator tubes. The program is useful in performing leak-before-break calculations in order to demonstrate detectable leak rates prior to a through-wall flaw reaching critical size. Necessary input to the code includes a definition of material properties, loads, thermal-hydraulic conditions, pipe geometry, and crack orientation. User information is provided in the report.

Norris, D.; Okamoto, A.; Chexal, B.; Griesbach, T.

1984-08-01T23:59:59.000Z

75

Wide-Area Thermal Processing of Light-Emitting Materials  

Science Conference Proceedings (OSTI)

Silicon carbide based materials and devices have been successfully exploited for diverse electronic applications. However, they have not achieved the same success as Si technologies due to higher material cost and higher processing temperatures required for device development. Traditionally, SiC is not considered for optoelectronic applications because it has an indirect bandgap. However, AppliCote Associates, LLC has developed a laser-based doping process which enables light emission in SiC through the creation of embedded p-n junctions. AppliCote laser irradiation of silicon carbide allows two different interaction mechanisms: (1) Laser conversion or induced phase transformation which creates carbon rich regions that have conductive properties. These conductive regions are required for interconnection to the light emitting semiconducting region. (2) Laser doping which injects external dopant atoms into the substrate that introduces deep level transition states that emit light when electrically excited. The current collaboration with AppliCote has focused on the evaluation of ORNL's unique Pulse Thermal Processing (PTP) technique as a replacement for laser processing. Compared to laser processing, Pulse Thermal Processing can deliver similar energy intensities (20-50 kW/cm2) over a much larger area (up to 1,000 cm2) at a lower cost and much higher throughput. The main findings of our investigation; which are significant for the realization of SiC based optoelectronic devices, are as follows: (1) The PTP technique is effective in low thermal budget activation of dopants in SiC similar to the laser technique. The surface electrical conductivity of the SiC samples improved by about three orders of magnitude as a result of PTP processing which is significant for charge injection in the devices; (2) The surface composition of the SiC film can be modified by the PTP technique to create a carbon-rich surface (increased local C:Si ratio from 1:1 to 2.9:1). This is significant as higher thermal and electrical conductivities of the surface layer are critical for a successful development of integrated optoelectronic devices; and (3) PTP provides low thermal budget dopant activation with a controlled depth profile, which can be exploited for high performance device development with selective patterning of the substrate. This project has successfully demonstrated that a low thermal budget annealing technique, such as PTP, is critical to defining the path for low cost electronic devices integrated on glass or polymeric substrates. This project is complimentary to the goals of the Solid State Lighting Program within DOE. It involves new manufacturing techniques for light emitting materials that are potentially much lower cost and energy efficient than existing products. Significant opportunity exists for further exploration of AppliCote's material and device technology in combination with ORNL's PTP technique, modeling, and characterization capabilities.

Duty, C.; Quick, N. (AppliCote Associates, LLC)

2011-09-30T23:59:59.000Z

76

Environmentally assisted cracking in light water reactors.  

DOE Green Energy (OSTI)

This report summarizes work performed by Argonne National Laboratory on fatigue and environmentally assisted cracking (EAC) in light water reactors (LWRs) from January to December 2002. Topics that have been investigated include: (a) environmental effects on fatigue crack initiation in carbon and low-alloy steels and austenitic stainless steels (SSs), (b) irradiation-assisted stress corrosion cracking (IASCC) of austenitic SSs in BWRs, (c) evaluation of causes and mechanisms of irradiation-assisted cracking of austenitic SS in PWRs, and (d) cracking in Ni-alloys and welds. A critical review of the ASME Code fatigue design margins and an assessment of the conservation in the current choice of design margins are presented. The existing fatigue {var_epsilon}-N data have been evaluated to define the effects of key material, loading, and environmental parameters on the fatigue lives of carbon and low-alloy steels and austenitic SSs. Experimental data are presented on the effects of surface roughness on fatigue crack initiation in these materials in air and LWR environments. Crack growth tests were performed in BWR environments on SSs irradiated to 0.9 and 2.0 x 10{sup 21} n x cm{sup -2}. The crack growth rates (CGRs) of the irradiated steels are a factor of {approx}5 higher than the disposition curve proposed in NUREG-0313 for thermally sensitized materials. The CGRs decreased by an order of magnitude in low-dissolved oxygen (DO) environments. Slow-strain-rate tensile (SSRT) tests were conducted in high-purity 289 C water on steels irradiated to {approx}3 dpa. The bulk S content correlated well with the susceptibility to intergranular SCC in 289 C water. The IASCC susceptibility of SSs that contain >0.003 wt. % S increased drastically. bend tests in inert environments at 23 C were conducted on broken pieces of SSRT specimens and on unirradiated specimens of the same materials after hydrogen charging. The results of the tests and a review of other data in the literature indicate that IASCC in 289 C water is dominated by a crack-tip grain-boundary process that involves S. An initial IASCC model has been proposed. A crack growth test was completed on mill annealed Alloy 600 in high-purity water at 289 C and 320 C under various environmental and loading conditions. The results from this test are compared with data obtained earlier on several other heats of Alloy 600.

Chopra, O. K.; Chung, H. M.; Clark, R. W.; Gruber, E. E.; Shack, W. J.; Soppet, W. K.; Strain, R. V.

2007-11-06T23:59:59.000Z

77

Thermally stable booster explosive and process for manufacture  

Science Conference Proceedings (OSTI)

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.

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

2006-03-21T23:59:59.000Z

78

Solution Processing of Polymer Nanotube Thermal Interface Materials  

Science Conference Proceedings (OSTI)

Ideal TIMs should exhibit high thermal conductivity and maintain mechanical ... bulk polymers exhibit phonon scattering and are poor conductors of thermal ...

79

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

E-Print Network (OSTI)

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

Kissock, Kelly

80

Coupled Electromagnetic and Thermal Modeling of Microwave Tissue Processing  

E-Print Network (OSTI)

This study deals with 3D finite element modeling of microwave tissue processing using Comsol software 4.0. Maxwell’s equations are coupled with heat conduction equation to determine electromagnetic field distribution and temperature profile within tissue sample in a reagent inside a domestic microwave oven. The microwave power generation term is calculated. Also, temperature distribution obtained is compared with experimental point measurements recorded in the centre of the tissue using a shielded K type thermocouple. Good agreement is found between numerical and experimental data. The effect of size of both reagent and tissue as well as tissue type on microwave heating patterns within tissue sample is investigated. Studies shows that the reagent volume has greater effect than other factors. The results of the study is considered as a basic foundation for development of coupled electromagnetic thermal models of microwave heating of tissue specimens. The model assists in choosing appropriate process parameters for achieving uniform temperature distribution within tissue specimen.

Osama A Hassan; Ahmed H K; Il Ences; Ahmed M El Bialy

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Characterization of Environment-Dependent Fatigue Crack Growth ...  

Science Conference Proceedings (OSTI)

at high frequency levels to fully environment-dependent at very low frequency ... environment-dependent crack growth process, crack increment per cycle is ...

82

Project W-320 SAR and process control thermal analyses  

SciTech Connect

This report summarizes the results of thermal hydraulic computer modeling supporting Project W-320 for process control and SAR documentation. Parametric analyses were performed for the maximum steady state waste temperature. The parameters included heat load distribution, tank heat load, fluffing factor and thermal conductivity. Uncertainties in the fluffing factor and heat load distribution had the largest effect on maximum waste temperature. Safety analyses were performed for off normal events including loss of ventilation, loss of evaporation and loss of secondary chiller. The loss of both the primary and secondary ventilation was found to be the most limiting event with saturation temperature in the bottom waste reaching in just over 30 days. An evaluation was performed for the potential lowering of the supernatant level in tank 241-AY-102. The evaluation included a loss of ventilation and steam bump analysis. The reduced supernatant level decreased the time to reach saturation temperature in the waste for the loss of ventilation by about one week. However, the consequence of a steam bump were dramatically reduced.

Sathyanarayana, K.

1997-06-19T23:59:59.000Z

83

Applications of fusion thermal energy to industrial processes  

DOE Green Energy (OSTI)

The feasibility of applying fusion thermal energy as process heat in the iron-steel industry, petrochemical industry, cement industry, and in the production of acetylene fom coal via calcium carbide are discussed. These four industries were selected for analysis because they require massive amounts of energy. This preliminary study concludes that the production of synthetic fuels using fusion heat appears to be the most promising method of storing and transporting this heat. Of the four industries studied, the iron-steel and the petrochemical industries appear to be the most promising because they consume substantial amounts of hydrogen and oxygen as feedstocks. These can be produced from water using the high-temperature fusion heat. The production of hydrogen and oxygen using fusion heat will also reduce the capital investment required for these industries. These two industries also consume tremendous amounts of heat at temperatures which can be delivered from a fusion blanket via chemical heat pipes.

Bowman, R.M.; Jody, B.J.; Lu, K.C.

1980-01-01T23:59:59.000Z

84

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

DOE Patents (OSTI)

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.

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

1999-07-20T23:59:59.000Z

85

The influence of loading rate on crack bridging processes in Al{sub 2}O{sub 3}  

SciTech Connect

Commercially available alumina of 94% nominal purity was used to examine the influence of loading rate on toughening mechanisms. For fine-grained alumina, the crack resistance, K{sub R}, was found to be independent of crack length and loading rate. Coarse-grained alumina exhibited strongly rising R-curves where the initial fracture toughness, K{sub 0}, was found to be independent of the loading rate. The net toughening, {Delta}K{sub ss} in coarse-grained alumina was found to decrease with increasing loading rate. Loading rate effects were independent of testing environment. A rate dependent coefficient of friction was incorporated into a crack bridging model to describe the effect of loading rate on toughness in this system. Predictions based on the bridging models, using the measured coefficients of friction for this material system, are in good agreement with the observed phenomenon.

Tandon, S.; Faber, K.T. [Northwestern Univ., Evanston, IL (United States)

1998-06-12T23:59:59.000Z

86

Supporting technology for enhanced oil recovery: EOR thermal processes  

Science Conference Proceedings (OSTI)

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.

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

1993-02-01T23:59:59.000Z

87

Cracking knuckles  

NLE Websites -- All DOE Office Websites (Extended Search)

Cracking knuckles Cracking knuckles Name: Renee Knuckles Location: N/A Country: N/A Date: N/A Question: Does cracking your joints especially the knuckles cause arthritis? What are some of the results of doing so? Replies: Cracking knuckles has NEVER been associated with causing arthritis. This concept is as wrong as saying weight lifting makes you short, or playing basketball makes you tall. The "popping" of the knuckles results from forcing joint fluid to very rapidly pass from one side of the joint to the other, where the "sides" are partitioned off by the main bones of the joint. Let me rephrase that: a joint is an area where two or more separate and distinct bones meet. The joint fluid provides a cushioning between the joints so that they don't grate into each other. Cracking your knuckles forces the joint fluid from one part of the joint to another, and the popping sound is just the result of the high pressured rushing of fluid.

88

Solar-Thermal Fluid-Wall Reaction Processing  

DOE Patents (OSTI)

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.

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

2006-04-25T23:59:59.000Z

89

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

E-Print Network (OSTI)

Tsang, Y.W. : Modeling the thermal-hydrologic processes in aanalyses of heterogeneity and thermal-loading factors for a2005 Lin, W. , Sun, Y. : Thermal hydrological processes in

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

2010-01-01T23:59:59.000Z

90

Analytical and experimental studies for thermal plasma processing of materials  

SciTech Connect

Work continued on thermal plasma processing of materials. This quarter, ceramic powders of carbides, aluminium nitride, oxides, solids solutions, magnetic and non magnetic spinels, superconductors, and composites have been successfully synthesized in a Triple DC Torch Plasma Jet Reactor (TTPR) and in a single DC Plasma Jet Reactor. All the ceramic powders with the exception of AIN were synthesized using a novel injection method developed to overcome the problems associated with solid injection, in particular for the single DC plasma jet reactor, and to realize the benefits of gas phase reactions. Also, initial experiments have been performed for the deposition of diamond coatings on Si wafers using the TTPR with methane as the carbon source. Well faceted diamond crystallites were deposited on the surface of the wafers, forming a continuous one particle thick coating. For measuring temperature and velocity fields in plasma systems, enthalpy probes have been developed and tested. The validity has been checked by performing energy and mass flux balances in an argon plasma jet operated in argon atmosphere. Total Gibbs free energy minimization calculations using a quasi-equilibrium modification have been applied to simulate several chemical reactions. Plasma reactor modelling has been performed for the counter-flow liquid injection plasma synthesis experiment. Plasma diagnostics has been initiated to determine the pressure gradient in the coalesced part of the plasma jet. The pressure gradient drives the diffusion of chemical species which ultimately controls the chemical reactions. 4 figs.

1990-01-01T23:59:59.000Z

91

Supporting technology for enhanced oil recovery for thermal processes  

SciTech Connect

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.

Reid, T.B.; Bolivar, J.

1997-12-01T23:59:59.000Z

92

Thermal Integration of CO2 Compression Processes with Coal-Fired...  

NLE Websites -- All DOE Office Websites (Extended Search)

Thermal Integration of CO 2 Compression Processes with Coal-Fired Power Plants Equipped with Carbon Capture Background Increased attention is being placed on research into...

93

Pulse Thermal Processing of Functional Materials Using a Directed Plasma Arc  

Using pulses of high density infrared light from a directed plasma arc, ORNL researchersinvented a method to thermally process thin films and other ...

94

Hydrogen Assisted Cracking  

Science Conference Proceedings (OSTI)

Environmentally Assisted Cracking (EAC): Laboratory Research and Field Experiences: Hydrogen Assisted Cracking Program Organizers: Suresh Divi, TIMET

95

Enhanced oil recovery: miscible flooding; thermal methods; and process implementation. Annual report, October 1, 1979-September 30, 1980  

Science Conference Proceedings (OSTI)

The individual papers in this volume covering miscible flooding, thermal methods, and process implementation were indexed.

Linville, B. (ed.)

1980-01-01T23:59:59.000Z

96

Vacuum Distillation  

U.S. Energy Information Administration (EIA) Indexed Site

Day) Process: Vacuum Distillation Thermal Cracking Thermal Cracking: Coking Thermal Cracking: Delayed Coking Thermal Cracking: Fluid Coking Thermal Cracking: Visbreaking Thermal...

97

Monitoring of thermal enhanced oil recovery processes with electromagnetic methods  

SciTech Connect

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.

Wilt, M.

1992-09-01T23:59:59.000Z

98

Representation of thermal energy in the design process  

E-Print Network (OSTI)

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

Roth, Shaun

1995-01-01T23:59:59.000Z

99

THERMAL DeNOx: A COMMERCIAL SELECTIVE NONCATALYTIC NOx REDUCTION PROCESS FOR  

E-Print Network (OSTI)

THERMAL DeNOx: A COMMERCIAL SELECTIVE NONCATALYTIC NOx REDUCTION PROCESS FOR WASTE when high NOx reduction is required. To illustrate the cost effectiveness, investment and operating in cinerators. INTRODUCTION THERMAL DeNO", a selective noncatalytic NO" reduction process, was invented just

Columbia University

100

Thermal Cracking - Energy Information Administration  

U.S. Energy Information Administration (EIA)

-No Data Reported; --= Not Applicable; NA = Not Available; W = Withheld to avoid disclosure of individual company data. Notes: See Definitions ...

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Bentonite alteration due to thermal-hydro-chemical processes during the early thermal period in a nuclear waste repository  

SciTech Connect

After closure of an underground nuclear waste repository, the decay of radionuclides will raise temperature in the repository, and the bentonite buffer will resaturate by water inflow from the surrounding host rock. The perturbations from these thermal and hydrological processes are expected to dissipate within hundreds to a few thousand years. Here, we investigate coupled thermal-hydro-chemical processes and their effects on the short-term performance of a potential nuclear waste repository located in a clay formation. Using a simplified geometric configuration and abstracted hydraulic parameters of the clayey formation, we examine geochemical processes, coupled with thermo-hydrologic phenomena, and potential changes in porosity near the waste container during the early thermal period. The developed models were used for evaluating the mineral alterations and potential changes in porosity of the buffer, which can affect the repository performance. The results indicate that mineral alteration and associated changes in porosity induced by early thermal and hydrological processes are relatively small and are expected to not significantly affect flow and transport properties. Chlorite precipitation was obtained in all simulation cases. A maximum of one percent volume fraction of chlorite could be formed, whose process may reduce swelling and sorption capacity of bentonite clay, affecting the performance of the repository. llitisation process was not obtained from the present simulations.

Xu, T.; Senger, R.; Finsterle, S.

2011-02-01T23:59:59.000Z

102

Thermal Spray and Cold Spray Processing - Programmaster.org  

Science Conference Proceedings (OSTI)

Mar 4, 2013 ... Cold Spray Processing (CSP) is a low temperature, high velocity powder spray process. In this research, billet size specimens are sought for ...

103

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

SciTech Connect

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.

Mayberry, J.; Geimer, R.; Gillins, R.; Steverson, E.M.; Dalton, D. (Science Applications International Corp., Idaho Falls, ID (United States)); Anderson, G.L. (EG and G Idaho, Inc., Idaho Falls, ID (United States))

1992-04-01T23:59:59.000Z

104

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  

Science Conference Proceedings (OSTI)

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.

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

2008-02-26T23:59:59.000Z

105

Thermal processes generated in quark-gluon plasma by yoctosecond laser pulses  

E-Print Network (OSTI)

In this paper the thermal processes generated by yoctosecond (10-24 s) laser pulses in QGP are investigated. Considering that the relaxation time in QGP is of the order of 1 ys it is shown that in QGP the yoctosecond laser pulses can generate the thermal waves with velocity v = c (0.3 fm/ys). Key words: QGP, thermal waves, yoctosecond pulses

Marciak-Kozlowska, J

2011-01-01T23:59:59.000Z

106

Thermal processes generated in quark-gluon plasma by yoctosecond laser pulses  

E-Print Network (OSTI)

In this paper the thermal processes generated by yoctosecond (10-24 s) laser pulses in QGP are investigated. Considering that the relaxation time in QGP is of the order of 1 ys it is shown that in QGP the yoctosecond laser pulses can generate the thermal waves with velocity v = c (0.3 fm/ys). Key words: QGP, thermal waves, yoctosecond pulses

J. Marciak-Kozlowska; M. Kozlowski

2011-07-03T23:59:59.000Z

107

Solar-Thermal Fluid-Wall Reaction Processing  

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 confine ...

108

Hydrocarbon Processing`s refining processes `96  

Science Conference Proceedings (OSTI)

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

NONE

1996-11-01T23:59:59.000Z

109

Process of making cryogenically cooled high thermal performance crystal optics  

DOE Patents (OSTI)

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.

Kuzay, T.M.

1990-06-29T23:59:59.000Z

110

Process of making cryogenically cooled high thermal performance crystal optics  

DOE Patents (OSTI)

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.

Kuzay, T.M.

1992-06-23T23:59:59.000Z

111

Creep Crack Growth  

Science Conference Proceedings (OSTI)

Table 3   Creep crack growth constants b and m for various ferritic steels...and Banerji, â??Creep Crack Growth Behavior

112

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

E-Print Network (OSTI)

Modern food processing operations often require that the temperature of the processed foodstuff be raised or lowered. These operations result in energy consumption by refrigeration or heating systems, and a portion of this energy can be recovered from waste heat streams for reuse in the processing operations. This paper addresses the recovery of waste heat and the storage of thermal energy as a means of energy conservation in food processing. An energy conservation project in a poultry processing plant sponsored by the U.S. Department of Energy and conducted by Georgia Tech is used as an illustrative example of potential applications of heat recovery and thermal energy storage.

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

1980-01-01T23:59:59.000Z

113

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

SciTech Connect

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, increasing the time available for experiments. For example, near Tg, on a typical laboratory time scale (e.g. {approx}1000 s), a water molecule moves less than a molecular distance. For this reason, nanoscale films help to probe the behavior and reactions of supercooled liquid at these low temperatures. ASW films can be used for investigating the non-thermal reactions relevant to radiolysis. In this account we will present a survey of our research on the thermal and non thermal properties of ASW using this approach.

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

2012-01-17T23:59:59.000Z

114

Stochastic thermal simulation considering spatial correlated within-die process variations  

Science Conference Proceedings (OSTI)

In this work, we develop a statistical thermal simulator including the effect of spatial correlation under within-die process variations. This method utilizes the Karhunen-Ločve (KL) expansion to model the physical parameters, and apply the Polynomial ...

Pei-Yu Huan; Jia-Hong Wu; Yu-Min Lee

2009-01-01T23:59:59.000Z

115

No-thermal plasma processing of VOCs and NO{sub x} at LLNL  

Science Conference Proceedings (OSTI)

For the past few years, Lawrence Livermore National Laboratory has been conducting a comprehensive research program on the application of non-thermal plasmas for air pollution control and abatement. This program combines an extensive modeling effort with an experimental facility and test program. We believe that there are two major issues to be addressed in order to apply non-thermal plasma processing to air pollution control; these are electrical energy consumption and byproduct identification. The thrust of our work has been to understand the scalability of the non-thermal process by focusing on the energy efficiency of the non-thermal process and to identify the byproducts to ensure that effluent gases from a non-thermal processor are benign. We have compared different types of electrical discharge reactors both theoretically and experimentally. Our interests in the application of non-thermal plasmas vary from the destruction of volatile organic compounds (VOCs) to NO{sub x} reduction for mobile applications. This paper will discuss the processing of both NO{sub x} and VOCs by non-thermal plasmas at LLNL.

Merritt, B.T.; Hsiao, M.C.; Penetrante, B.M.; Vogtlin, G.E.; Wallman, P.H.

1995-02-15T23:59:59.000Z

116

Indirect thermal liquefaction process for producing liquid fuels from biomass  

DOE Green Energy (OSTI)

A progress report on an indirect liquefaction process to convert biomass type materials to quality liquid hydrocarbon fuels by gasification followed by catalytic liquid fuels synthesis has been presented. A wide variety of feedstocks can be processed through the gasification system to a gas with a heating value of 500 + Btu/SCF. Some feedstocks are more attractive than others with regard to producing a high olefin content. This appears to be related to hydrocarbon content of the material. The H/sub 2//CO ratio can be manipulated over a wide range in the gasification system with steam addition. Some feedstocks require the aid of a water-gas shift catalyst while others appear to exhibit an auto-catalytic effect to achieve the conversion. H/sub 2/S content (beyond the gasification system wet scrubber) is negligible for the feedstocks surveyed. The water gas shift reaction appears to be enhanced with an increase in pyrolysis reactor temperature over the range of 1300 to 1700/sup 0/F. Reactor temperature in the Fischer-Tropsch step is a significant factor with regard to manipulating product composition analysis. The optimum temperature however will probably correspond to maximum conversion to liquid hydrocarbons in the C/sub 5/ - C/sub 17/ range. Continuing research includes integrated system performance assessment, alternative feedstock characterization (through gasification) and factor studies for gasification (e.g., catalyst usage, alternate heat transfer media, steam usage, recycle effects, residence time study) and liquefaction (e.g., improved catalysts, catalyst activity characterization).

Kuester, J.L.

1980-01-01T23:59:59.000Z

117

Origin of undesirable cracks during layer transfer  

E-Print Network (OSTI)

We investigate the origin of undesirable transverse cracks often observed in thin films obtained by the layer transfer technique. During this process, two crystals bonded to each other containing a weak plan produced by ion implantation are heated to let a thin layer of one of the material on the other. The level of stress imposed on the film during the heating phase due to the mismatch of thermal expansion coefficients of the substrate and the film is shown to be the relevant parameter of the problem. In particular, it is shown that if the film is submitted to a tensile stress, the microcracks produced by ion implantation are not stable and deviate from their straight trajectory making the layer transfer process impossible. However, if the compressive stress exceeds a threshold value, after layer transfer, the film can buckle and delaminate, leading to transverse cracks induced by bending. As a result, we show that the imposed stress \\sigma_m - or equivalently the heating temperature - must be within the ran...

Ponson, Laurent; Atwater, Harry; Ravichandran, Guruswami; Bhattacharya, Kaushik

2008-01-01T23:59:59.000Z

118

PICEP: Pipe Crack Evaluation Program (Revision 1): Special report  

Science Conference Proceedings (OSTI)

This report describes software for calculating single- or two-phase flow through cracks in pipes and steam generator tubes. Options are available for calculating the crack-opening area and the critical (stable) crack length. The program is useful in performing leak-before-break analysis to demonstrate detectable leak rates prior to crack growth instability. Input to the code includes material properties, loads, thermal-hydraulic conditions, pipe geometry, and crack type and orientation. Theory and user information are provided in this report. 16 refs., 7 figs.

Norris, D.M.; Chexal, B.

1987-12-01T23:59:59.000Z

119

THERMODYNAMIC CONSIDERATIONS FOR THERMAL WATER SPLITTING PROCESSES AND HIGH TEMPERATURE ELECTROLYSIS  

DOE Green Energy (OSTI)

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.

J. E. O'Brien

2008-11-01T23:59:59.000Z

120

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

DOE Patents (OSTI)

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.

Sheldon, Ray W. (Huntley, MT)

2001-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Thermal Systems Process and Components Laboratory (Fact Sheet), NREL (National Renewable Energy Laboratory), Energy Systems Integration Facility (ESIF)  

NLE Websites -- All DOE Office Websites (Extended Search)

Systems Process and Systems Process and Components Laboratory may include: * CSP technology developers * Utilities * Certification laboratories * Government agencies * Universities * Other National laboratories Contact Us If you are interested in working with NREL's Thermal Systems Process and Components Laboratory, please contact: ESIF Manager Carolyn Elam Carolyn.Elam@nrel.gov 303-275-4311 Thermal Systems Process and Components Laboratory 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

122

Environmentally Assisted Cracking: Nuclear  

Science Conference Proceedings (OSTI)

About this Symposium. Meeting, Materials Science & Technology 2014. Symposium, Environmentally Assisted Cracking: Nuclear. Sponsorship. Organizer(s) ...

123

Nonlinear structural crack growth monitoring  

DOE Patents (OSTI)

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.

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

2002-01-01T23:59:59.000Z

124

A thermal computation program of process steam boilers obtained with reusable equipments and plants  

Science Conference Proceedings (OSTI)

This paper presents a process steam boiler dimensioned by means of two computer programs. The first computer program entitled "thermal computation of the chamber furnace of boiler" provides the utilization of the Boltzmann criterion. This computer program ... Keywords: boiler, chamber furnace, computer program, heat exchanger

Aurel Gaba; Ion-Florin Popa; Alexis-Daniel Negrea

2010-05-01T23:59:59.000Z

125

Combined System of Monothermal Chemical Exchange Process with Electrolysis and Thermal Diffusion Process for Enriching Tritium  

Science Conference Proceedings (OSTI)

Tritium Processing / Proceedings of the Third Topical Meeting on Tritium Technology in Fission, Fusion and Isotopic Applications (Toronto, Ontario, Canada, May 1-6, 1988)

Asashi Kitamoto; Katsuo Hasegawa; Takashi Masui

126

Enhanced oil recovery for thermal processes. First amendment and extension to Annex IV  

Science Conference Proceedings (OSTI)

This report contains the result of efforts under the several tasks of the First Amendment and Extension of Annex IV, Enhanced Oil Recovery Thermal processes. The report is presented in six sections (for each of the six tasks) and each section contains one or more reports prepared by various individuals or groups describing the results of efforts under each one of the tasks. Each section has been abstracted and processed for inclusion in the Energy Data Base. A statement of each task, taken from the agreement, is presented on the first page of each section. The tasks are numbered 8-13. The first report on Annex IV, Venezuela-MEM/USE-DOE Fossil Energy Report IV-1, (DOE/BETC/SP-83/15), contains the results from the first seven tasks. That report is dated April 1983, entitled, EOR Thermal Processes.

Peterson, G.; Schwartz, E.

1984-08-01T23:59:59.000Z

127

Modeling of thermally driven hydrological processes in partially saturated fractured rock  

Science Conference Proceedings (OSTI)

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.

Tsang, Yvonne; Birkholzer, Jens; Mukhopadhyay, Sumit

2009-03-15T23:59:59.000Z

128

Laboratory And Field Investigations To Address Erosion, Volume Change And Desiccation Cracking Of Compost Amended Expansive Subsoils.  

E-Print Network (OSTI)

??Puppala, Anand Desiccations cracks are formed during drying process of fine grained cohesive soils in summer and these cracks often appear on unpaved subgrades due… (more)

Intharasombat, Napat

2007-01-01T23:59:59.000Z

129

3:2:1 Crack Spread  

Gasoline and Diesel Fuel Update (EIA)

:2:1 Crack Spread :2:1 Crack Spread Figure 1 Source: U.S. Energy Information Administration, based on Thomson Reuters. A crack spread measures the difference between the purchase price of crude oil and the selling price of finished products, such as gasoline and distillate fuel, that a refinery produces from the crude oil. Crack spreads are an indicator of the short-term profit margin of oil refineries because they compare the cost of the crude oil inputs to the wholesale, or spot, prices of the outputs (although they do not include other variable costs or any fixed costs). The 3:2:1 crack spread approximates the product yield at a typical U.S. refinery: for every three barrels of crude oil the refinery processes, it makes two barrels of gasoline and one barrel of distillate

130

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

DOE Green Energy (OSTI)

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.

Not Available

2004-11-04T23:59:59.000Z

131

Baroclinic Adjustment in an Atmosphere–Ocean Thermally Coupled Model: The Role of the Boundary Layer Processes  

Science Conference Proceedings (OSTI)

Baroclinic eddy equilibration and the roles of different boundary layer processes in limiting the baroclinic adjustment are studied using an atmosphere–ocean thermally coupled model. Boundary layer processes not only affect the dynamical ...

Yang Zhang; Peter H. Stone

2011-11-01T23:59:59.000Z

132

Solar thermal hydrogen production process. Annual technical progress report, January-December, 1979  

DOE Green Energy (OSTI)

Westinghouse is currently under contract to DOE for technology development of the Sulfur Cycle, a hybrid thermochemical-electrochemical process for the production of hydrogen and oxygen from water. Operational studies have been conducted and have resulted in definitions of operating modes for solar/hydrogen plants and in assessments of the day/night and annual variations in performance that will influence the operating modes and the sizing of plant subsystems. Conceptual design studies have been conducted for process components that interface with the solar receiver. From related trade-off studies, a preferred configuration emerged that involves an intermediate working fluid (e.g., hot gas) between the solar receiver and the sulfuric acid decomposition reactor. The design of the reactor has been based on a shell and tube type heat exchanger configuration with catalyst placement on the shell side. A number of candidate materials for structural use in the acid decomposition reactor also have been evaluated experimentally. Screening tests and endurance tests with potential catalysts (to accelerate the rate of sulfur trioxide cracking) have been conducted with encouraging results. Approximately three dozen candidate materials for use in constructing the acid vaporizer have been tested for corrosion resistance to the expected environment. Detailed discussions of the results obtained during 1979 are presented.

Parker, G.H.

1979-01-01T23:59:59.000Z

133

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

E-Print Network (OSTI)

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

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

2013-01-01T23:59:59.000Z

134

Cracks Cleave Crystals  

E-Print Network (OSTI)

The problem of finding what direction cracks should move is not completely solved. A commonly accepted way to predict crack directions is by computing the density of elastic potential energy stored well away from the crack tip, and finding a direction of crack motion to maximize the consumption of this energy. I provide here a specific case where this rule fails. The example is of a crack in a crystal. It fractures along a crystal plane, rather than in the direction normally predicted to release the most energy. Thus, a correct equation of motion for brittle cracks must take into account both energy flows that are described in conventional continuum theories and details of the environment near the tip that are not.

Michael Marder

2004-03-05T23:59:59.000Z

135

Solidification Cracking Study of High Chromium Nickel-Base Filler ...  

Science Conference Proceedings (OSTI)

... and rank the relative cracking susceptibility of these filler metal specifications. ... Surface Processing of Ag /TiO2 Nanowire Membranes for Solar Photovoltaic ...

136

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

Science Conference Proceedings (OSTI)

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

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

2012-12-03T23:59:59.000Z

137

Elastoplastic analysis of process induced residual stresses in thermally sprayed coatings  

SciTech Connect

The residual stresses induced from thermal spraying process have been extensively investigated in previous studies. However, most of such works were focused on the elastic deformation range. In this paper, an elastoplastic model for predicting the residual stresses in thermally sprayed coatings was developed, in which two main contributions were considered, namely the deposition induced stress and that due to differential thermal contraction between the substrate and coating during cooling. The deposition induced stress was analyzed based on the assumption that the coating is formed layer-by-layer, and then a misfit strain is accommodated within the multilayer structure after the addition of each layer (plastic deformation is induced consequently). From a knowledge of specimen dimensions, processing temperatures, and material properties, residual stress distributions within the structure can be determined by implementing the model with a simple computer program. A case study for the plasma sprayed NiCoCrAlY on Inconel 718 system was performed finally. Besides some similar phenomena observed from the present study as compared with previous elastic model reported in literature, the elastoplastic model also provides some interesting features for prediction of the residual stresses.

Chen Yongxiong; Liang Xiubing; Liu Yan; Xu Binshi [National Key Laboratory for Remanufacturing, Academy of Armored Forces Engineering, Beijing 100072 (China)

2010-07-15T23:59:59.000Z

138

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

SciTech Connect

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.

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

1993-02-01T23:59:59.000Z

139

Stress corrosion cracking behavior of Alloy 600 in high temperature water  

Science Conference Proceedings (OSTI)

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 (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.

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

1995-07-01T23:59:59.000Z

140

Formation processes and main properties of hollow aluminosilicate microspheres in fly ash from thermal power stations  

Science Conference Proceedings (OSTI)

The main parameters of aluminosilicate microspheres formed at thermal power stations in Russia were studied. These parameters are responsible for the prospective industrial application of these microspheres. A comparative analysis of the properties of mineral coal components, the conditions of coal combustion, and the effects of chemical and phase-mineralogical compositions of mineral impurities in coals from almost all of the main coal deposits on the formation of microspheres was performed. The effects of thermal treatment conditions on gas evolution processes in mineral particles and on the fraction of aluminosilicate microspheres in fly ash were considered. It was found that the yield of microspheres was higher in pulverized coal combustion in furnaces with liquid slag removal, all other factors being equal. The regularities of microsphere formation were analyzed, and the mechanism of microsphere formation in fly ash during the combustion of solid fuels was considered.

V.S. Drozhzhin; M.Ya. Shpirt; L.D. Danilin; M.D. Kuvaev; I.V. Pikulin; G.A. Potemkin; S.A. Redyushev [Russian Federal Nuclear Center VNIIEF, Nizhegorodskaya oblast (Russia)

2008-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Site-specific investigations of aquifer thermal energy storage for space and process cooling  

Science Conference Proceedings (OSTI)

The Pacific Northwest Laboratory (PNL) has completed three preliminary site-specific feasibility studies that investigated using aquifer thermal energy storage (ATES) to reduce space and process cooling costs. Chilled water stored in an ATES system could be used to meet all or part of the process and/or space cooling loads at the three facilities investigated. The work was sponsored by the US Department of Energy's (DOE) Office of Energy Management. The ultimate goal of DOE's Thermal Energy Storage Program is to successfully transfer ATES technology to industrial and commercial sectors. The primary objective of this study was to identify prospective sites and determine the technical and economic feasibility of implementing chill ATES technology. A secondary objective was to identify site-specific factors promoting or inhibiting the application of chill ATES technology so that other potentially attractive sites could be more easily identified and evaluated. A preliminary investigation of the feasibility of commercializing chill ATES in automotive assembly facilities was completed. The results suggested that automotive assembly facilities was completed. The results suggested that automotive assembly facilities represent a good entry market for chill ATES, if the system is cost-effective. As a result, this study was undertaken to identify and evaluate prospective chill ATES applications in the automotive industry. The balance of the report contains two main sections. Section 2.0 describes the site identification process. Site feasibility is addressed in Section 3.0. Overall study conclusions and recommendations are than presented in Section 4.0.

Brown, D R; Hattrup, M P; Watts, R L

1991-08-01T23:59:59.000Z

142

Second amendment and extension to Annex IV enhanced oil recovery thermal processes  

Science Conference Proceedings (OSTI)

This report contains the result of efforts under the several tasks of the Second Amendment and Extension of Annex IV, Enhanced Oil Recovery Thermal Processes of the Venezuela/USA Energy Agreement. The report is presented in sections (for each of the 12 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 11 and 14 through 24. The first and second reports on Annex IV, Venezuela-MEM/USA-DOE Fossil Energy Report IV-1 and Report IV-2 (DOE/BETS/SP-83/15 and DOE/BC-84/6/SP), contain the results from the first 14 tasks, with the exception of an INTEVEP Survey for Task II which is included here. Those reports are dated April 1983 and August 1984 and are both entitled, ''EOR Thermal Processes''. Selected papers have been processed for inclusion in the Energy Data Base.

Peterson, G.; Munoz, J.D.

1986-03-01T23:59:59.000Z

143

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

SciTech Connect

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.

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

2011-02-01T23:59:59.000Z

144

Physical and thermal properties and leaching characteristics of a beneficiated eastern oil shale hydroretorted in the PFH process  

SciTech Connect

The preferred feedstocks for the Institute of Gas Technology`s (IGT) Pressurized Fluidized-Bed Hydroretorting (PFH) process are beneficiated Eastern US oil shales. After hydroretorting, the beneficiated shale is combusted to generate process and export power. Before hydroretorting and after combustion the shale will be stored in large embankments. The design and characteristics of these embankments depends on the physical, thermal, and leaching properties of the raw and spent shales. IGT and the Illinois Institute of Technology conducted tests to determine the physical and thermal properties and leaching characteristics of samples of beneficiated and thermally processed Alabama shale. The physical and thermal properties determined include permeability, compressibility, compactability, consolidation, shear stress, cohesion, thermal conductivity, and liquid and plastic limits. Tests were conducted on samples of raw, hydroretorted, hydroretorted and combusted (H&C), and the results show that the physical properties of raw and thermally processed beneficiated shale are considerably different. Leachability test results show that none of the thermally processed shale samples exhibited the toxicity characteristic [per the Toxicity Characteristic Leaching Procedure (TCLP)]. Combustion and agglomeration reduced the levels of metals leached from the H&C and H&A shale samples during TCLP tests. Overall, storage of raw and spent beneficiated shales in embankments will not result in significant environmental impacts

Mensinger, M.C. [Institute of Gas Technology, Chicago, IL (United States); Budiman, J.S. [Illinois Inst. of Technology, Chicago, IL (United States). Dept. of Civil Engineering

1992-12-31T23:59:59.000Z

145

Age-based preventive maintenance for passive components submitted to stress corrosion cracking  

Science Conference Proceedings (OSTI)

This paper deals with an age-based preventive maintenance for critical systems or structures subject to a gradual degradation phenomenon such as stress corrosion cracking. We analyze a system subjected to different cracks. A crack can be only detected ... Keywords: Age-based maintenance, Counting processes, Gamma process, Non-homogeneous Poisson process, SCC models

I. T. Castro; Anne Barros; Antoine Grall

2011-07-01T23:59:59.000Z

146

Nucleation and growth of cracks in vitreous-bonded aluminum oxide at elevated temperatures  

Science Conference Proceedings (OSTI)

The nucleation and growth of cracks was studied at elevated temperatures on a grade of vitreous-bonded aluminium oxide that contained approx. =8 vol% glass at the grain boundaries. Cracks were observed to nucleate within the vitreous phase, close to the tensile surface of the flexural test specimens used in these experiments. Crack nucleation occurred at a strain of approx. =0.08% to 0.12% which corresponded to a crack nucleation time of approx. =35% of the time to failure by creep rupture. Once nucleated, cracks propagated along grain boundaries, as long as the stress for crack propagation was maintained. The crack velocity for cracks that were nucleated by the creep process was found to be linearly proportional to the apparent stress intensity factor, whereas for cracks that were nucleated by indentation, the crack velocity was proportional to the fourth power of the apparent stress intensity factor.

Jakus, K.; Wiederhorn, S.M.; Hockey, B.J.

1986-10-01T23:59:59.000Z

147

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

DOE Green Energy (OSTI)

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.

Niessen, W.R.; Marks, C.H.; Sommerlad, R.E. [Camp Dresser and McKee, Inc., Cambridge, MA (United States)] [Camp Dresser and McKee, Inc., Cambridge, MA (United States)

1996-08-01T23:59:59.000Z

148

A method to determine stratification efficiency of thermal energy storage processes independently from storage heat losses  

Science Conference Proceedings (OSTI)

A new method for the calculation of a stratification efficiency of thermal energy storages based on the second law of thermodynamics is presented. The biasing influence of heat losses is studied theoretically and experimentally. Theoretically, it does not make a difference if the stratification efficiency is calculated based on entropy balances or based on exergy balances. In practice, however, exergy balances are less affected by measurement uncertainties, whereas entropy balances can not be recommended if measurement uncertainties are not corrected in a way that the energy balance of the storage process is in agreement with the first law of thermodynamics. A comparison of the stratification efficiencies obtained from experimental results of charging, standby, and discharging processes gives meaningful insights into the different mixing behaviors of a storage tank that is charged and discharged directly, and a tank-in-tank system whose outer tank is charged and the inner tank is discharged thereafter. The new method has a great potential for the comparison of the stratification efficiencies of thermal energy storages and storage components such as stratifying devices. (author)

Haller, Michel Y.; Streicher, Wolfgang [Institute of Thermal Engineering, Graz University of Technology, Inffeldgasse 25/B, 8010 Graz (Austria); Yazdanshenas, Eshagh; Andersen, Elsa; Furbo, Simon [Department of Civil Engineering, Technical University of Denmark, Brovej, Building 118, DK-2800, Kgs. Lyngby (Denmark); Bales, Chris [Solar Energy Research Center SERC, Hoegskolan Dalarna, 781 88 Borlaenge (Sweden)

2010-06-15T23:59:59.000Z

149

Fundamental limitations of non-thermal plasma processing for internal combustion engine NO{sub x} control  

DOE Green Energy (OSTI)

This paper discusses the physics and chemistry of non-thermal plasma processing for post-combustion NO{sub x} control in internal combustion engines. A comparison of electron beam and electrical discharge processing is made regarding their power consumption, radical production, NO{sub x} removal mechanisms, and by product formation. Can non-thermal deNO{sub x} operate efficiently without additives or catalysts? How much electrical power does it cost to operate? What are the by-products of the process? This paper addresses these fundamental issues based on an analysis of the electron-molecule processes and chemical kinetics.

Penetrante, B.M.

1993-08-19T23:59:59.000Z

150

LPG storage vessel cracking experience  

SciTech Connect

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.

Cantwell, J.E. (Caltex Petroleum Corp., P.O. Box 619500, Dallas, TX (US))

1988-10-01T23:59:59.000Z

151

LPG storage vessel cracking experience  

SciTech Connect

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.

Cantwell, J.E.

1988-01-01T23:59:59.000Z

152

Advanced research in coal gasification process modification technology: catalytic cracking of aromatic hydrocarbons. Topical report, 1 October 1984-31 June 1985  

SciTech Connect

The objective of this work is to screen inexpensive materials for potential use as disposable aromatic hydrocarbon (AHC) cracking catalysts in the reaction zone of the coal gasifier or in a fixed bed downstream from the gasifier. The approach is based on the conclusions reported in the literature that iron in a reduced state is an effective catalyst for AHC destruction. It therefore follows that chars or minerals with high iron content, high porosity, and high internal surface area will provide the most effective catalysts. We have screened all six of the following iron containing minerals: Siderite, Ankerite, Hematite, Magnetite, Pyrite, and Jarosite. The experimental tests measure the catalytic activity of these minerals for cracking benzene over the parameter range relevant to coal gasifier operation. Simulated coal gas containing 200 to 2000 ppM of model aromatic molecules will be used in all experiments and destruction of benzene will be measured over the temperature range 400 to 1000/sup 0/C. The porosity and surface area of these minerals (partially decomposed in coal gas) will be determined and utilized in a computer model describing pore structure, species transport and surface chemistry to interpret the reactivity data in terms of the intrinsic reactivity of the reduced state of each mineral. These results will provide a basis for catalyst selection, coal selection and economic comparison. 3 refs., 15 figs., 3 tabs.

Simons, G.A.; Ham, D.A.; Moniz, G.A.

1985-08-01T23:59:59.000Z

153

Crack tip plasticity in single crystal UO2: Atomistic simulations  

SciTech Connect

The fracture behavior of single crystal uranium dioxide is studied using molecular dynamics simulations at room temperature. Initially, an elliptical notch is created on either {111} or {110} planes, and tensile loading is applied normal to the crack planes. For cracks on both planes, shielding of crack tips by plastic deformation is observed, and crack extension occurs for crack on {111} planes only. Two plastic processes, dislocation emission and phase transformation are identified at crack tips. The dislocations have a Burgers vector of ?110?/2, and glide on {100} planes. Two metastable phases, the so-called Rutile and Scrutinyite phases, are identified during the phase transformation, and their relative stability is confirmed by separate density- functional-theory calculations. Examination of stress concentration near crack tips reveals that dislocation emission is not an effective shielding mechanism. The formation of new phases may effectively shield the crack provided all phase interfaces formed near the crack tips are coherent, as in the case of cracks residing on {110} planes.

Yongfeng Zhang; Paul C. Millett; Michael Tonks; Bulent Biner; Xiang-Yang Liu; David A. Andersson

2012-11-01T23:59:59.000Z

154

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

DOE Patents (OSTI)

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.

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

1987-01-01T23:59:59.000Z

155

Thermal Cracking Visbreaking Downstream Charge Capacity  

U.S. Energy Information Administration (EIA)

-No Data Reported; --= Not Applicable; NA = Not Available; W = Withheld to avoid disclosure of individual company data. Notes: See Definitions ...

156

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

DOE Green Energy (OSTI)

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

Not Available

1982-12-01T23:59:59.000Z

157

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

DOE Green Energy (OSTI)

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

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

2001-05-29T23:59:59.000Z

158

The thermal expansion coefficient as a key design parameter for thermoelectric materials and its relationship to processing-dependent bloating  

Science Conference Proceedings (OSTI)

The coefficient of thermal expansion (CTE) is a key design parameter for thermoelectric (TE) materials, especially in energy harvesting applications since stresses generated by CTE mismatch, thermal gradients, and thermal transients scale with the CTE of the TE material. For the PbTe PbS-based TE material (Pb 0.95 Sn 0.05 Te) 0.92(PbS) 0.08 0.055 % PbI 2 over the temperature ranges of 293 543 and 293 773 K, a CTE, alpha avg , of 21.4 0.3 x 10-6 K-1 was measured using (1) dilatometry and (2) high-temperature X-ray diffraction (HT-XRD) for powder and bulk specimens. The CTE values measured via dilatometry and HT-XRD are similar to the literature values for other Pb-based chalcogenides. However, the processing technique was found to impact the thermal expansion such that bloating (which leads to a hysteresis in thermal expansion) occurred for hot pressed billets heated to temperatures [603 K while specimens fabricated by pulsed electric current sintering and as-cast specimens did not show a bloating-modified thermal expansion even for temperatures up to 663 K. The relationship of bloating to the processing techniques is discussed, along with a pos- sible mechanism for inhibiting bloating in powder processed specimens.

Ni, Jennifer E. [Michigan State University, East Lansing; Case, Eldon D [Michigan State University, East Lansing; Schmidt, Robert [Michigan State University, East Lansing; Wu, Chun-I [Michigan State University, East Lansing; Hogan, Timothy [Michigan State University, East Lansing; Trejo, Rosa M [ORNL; Kirkham, Melanie J [ORNL; Lara-Curzio, Edgar [ORNL; Kanatzidis, Mercouri G. [Northwestern University, Evanston

2013-01-01T23:59:59.000Z

159

Corrosion Fatigue Crack Growth and Stress-Corrosion Cracking in ...  

Science Conference Proceedings (OSTI)

Abstract Scope, The high stress ratio (R=0.85) corrosion fatigue crack growth kinetics and stress-corrosion cracking resistance of sensitized (70-175 °C up to ...

160

Rapid thermal processing of high-efficiency silicon solar cells with controlled in-situ annealing  

DOE Green Energy (OSTI)

Silicon solar cell efficiencies of 17.1%, 16.4%, 14.8%, and 14.9% have been achieved on FZ, Cz, multicrystalline (mc-Si), and dendritic web (DW) silicon, respectively, using simplified, cost-effective rapid thermal processing (RTP). These represent the highest reported efficiencies for solar cells processed with simultaneous front and back diffusion with no conventional high-temperature furnace steps. Appropriate diffusion temperature coupled with the added in-situ anneal resulted in suitable minority-carrier lifetime and diffusion profiles for high-efficiency cells. The cooling rate associated with the in-situ anneal can improve the lifetime and lower the reverse saturation current density (J{sub 0}), however, this effect is material and base resistivity specific. PECVD antireflection (AR) coatings provided low reflectance and efficient front surface and bulk defect passivation. Conventional cells fabricated on FZ silicon by furnace diffusions and oxidations gave an efficiency of 18.8% due to greater short wavelength response and lower J{sub 0}.

Doshi, P.; Rohatgi, A.; Ropp, M.; Chen, Z. [Georgia Institute of Technology, Atlanta, GA (United States). Univ. Center of Excellence for Photovoltaics Research and Education; Ruby, D. [Sandia National Labs., Albuquerque, NM (United States); Meier, D.L. [EBARA Solar, Inc., Large, PA (United States)

1995-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

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

DOE Green Energy (OSTI)

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.

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

2012-09-01T23:59:59.000Z

162

Hydrogen induced crack growth in Grade-12 titanium  

DOE Green Energy (OSTI)

Internal hydrogen induced crack growth rates were measured in Grade-12 titanium which is a candidate material for high-level nuclear waste containers. As-received and hydrogen charged samples (5 ppM to 330 ppM hydrogen) were used for slow crack growth measurements at constant loads using a Krak Gauge. The testing temperature ranged from room temperature to 148/sup 0/C. The crack growth kinetics under low to moderate loads are linear, but this linear rate is interrupted by discrete fast crack jump segments with parabolic or cubic type kinetics. These fast jump segments are thought to be associated with the passage of the crack front through the alpha-beta interface phase or with the initial loading sequence. By measuring striation spacings on the fracture surface, most crack growth rates observed are found to be in stage II. The striations are considered to be associated with hydride fracture. The crack path is either transgranular in the alpha phase or interfacial in the alpha phase adjacent to the beta phase. For transgranular growth, crack growth rates are constant and slower than those for interfacial growth which is associated with fast crack growth through a high hydrogen concentration region. Most stage II crack growth rates depend slightly on the stress intensity suggesting the contribution of plastic tearing process to stage II kinetics. The activation energies for crack growth are much lower than the activation energy of hydrogen diffusion through the alpha phase, implying that hydrogen is transported along dislocations, grain boundaries or interfaces. When the temperature is increased, the crack velocity first reaches a maximum and then decreases at higher temperatures. These temperature effects come from lower hydrogen concentration trapped at dislocations or from slower hydride nucleation kinetics, both at higher temperatures.

Ahn, T.M.; Lee, K.S.

1984-01-01T23:59:59.000Z

163

Segmentation of cracks in shale rock  

Science Conference Proceedings (OSTI)

In this paper the use of morphological connected filters are studied for segmenting sheet- and thread-like cracks in images of shale rock. A volume formed from a stack of 2-D X-ray images is processed using 3-D attributes. The shape-preserving property ...

Erik R. Urbach; Marina Pervukhina; Leanne Bischof

2011-07-01T23:59:59.000Z

164

STRESS CORROSION CRACKING IN TEAR DROP SPECIMENS  

SciTech Connect

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.

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

2009-05-01T23:59:59.000Z

165

Crack Growth in Solid Oxide Fuel Cell Materials: From Discrete to Continuum Damage Modeling  

Science Conference Proceedings (OSTI)

This paper addresses the cracking problem of glass and ceramic materials used in solid oxide fuel cells (SOFCs). Analyses of an internal crack and of an interface crack between dissimilar materials were conducted using a modified boundary layer modeling approach. In this approach, fracture is allowed to occur in a small process window situated at an initial crack tip. Elastic displacement crack-tip fields are prescribed as remote boundary conditions. Crack propagation was first modeled discretely. Next, a continuum damage mechanics (CDM) model for brittle materials was developed to capture damage and crack growth in the process window. In particular, the damage model was applied to a glass-ceramic material that had been developed in-house for sealing purposes. Discrete and continuum damage solutions were then compared. Finally, the CDM model was used to determine the crack propagation direction as a function of a mode mixity measure.

Nguyen, Ba Nghiep; Koeppel, Brian J.; Ahzi, Said; Khaleel, Mohammad A.; Singh, Prabhakar

2006-04-01T23:59:59.000Z

166

Analysis of Cracked Pipe Weldments  

Science Conference Proceedings (OSTI)

EPRI estimation formulas for predicting loads necessary for crack initiation and instability can facilitate leak-before-break analysis of cracked nuclear piping. Finite-element calculations carried out in this study verified the accuracy of these formulas for analyzing through-the-wall cracks in bimetallic weldments.

1987-02-01T23:59:59.000Z

167

Thermal Flue Gas Desulfurization Wastewater Treatment Processes for Zero Liquid Discharge Operations  

Science Conference Proceedings (OSTI)

This report presents a worldwide inventory of power plant flue gas desulfurization (FGD) blowdown treatment systems using thermal technologies to achieve zero liquid discharge (ZLD) water management. The number of thermal treatment systems presently operating is very few, with the majority using chemical pretreatment followed by evaporation in a brine concentrator and crystallizer and finally dewatering of the residual salts. Of the operating thermal ZLD systems identified, six are located in Italy and o...

2010-12-31T23:59:59.000Z

168

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

E-Print Network (OSTI)

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

Brooks, Zenzile (Zenzile Z.)

2013-01-01T23:59:59.000Z

169

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

E-Print Network (OSTI)

on slow crack growth and stress corrosion processes [Wiederhorn, 1966; Anderson and Grew, 1977; Atkinson for independent controls of the confining pressure, the axial stress, and pore pressure. We produced cracks, to our knowledge, none con- sidered crack evolution under compressive stress. Some of this work explored

Fortin, JĂ©rĂ´me

170

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

SciTech Connect

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.

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

1983-01-01T23:59:59.000Z

171

Thermal removal of mercury in spent powdered activated carbon from TOXECON process  

SciTech Connect

This research developed and demonstrated a technology to liberate Hg adsorbed onto powdered activated carbon (PAC) by the TOXECON process using pilot-scale high temperature air slide (HTAS) and bench-scale thermogravimetric analyzer (TGA). The HTAS removed 65, 83, and 92% of Hg captured with PAC when ran at 900{sup o}F, 1,000{sup o}F, and 1,200 {sup o}F, respectively, while the TGA removed 46 and 100% of Hg at 800 {sup o}F and 900{sup o}F, respectively. However, addition of CuO-Fe{sub 2}O{sub 3} mixture and CuCl catalysts enhanced Hg removal and PAC regeneration at lower temperatures. CuO-Fe{sub 2}O{sub 3} mixture performed better than CuCl in PAC regeneration. Scanning electron microscopy images and energy dispersive X-ray analysis show no change in PAC particle aggregation or chemical composition. Thermally treated sorbents had higher surface area and pore volume than the untreated samples indicating regeneration. The optimum temperature for PAC regeneration in the HTAS was 1,000{sup o}F. At this temperature, the regenerated sorbent had sufficient adsorption capacity similar to its virgin counterpart at 33.9% loss on ignition. Consequently, the regenerated PAC may be recycled back into the system by blending it with virgin PAC.

Okwadha, G.D.O.; Li, J.; Ramme, B.; Kollakowsky, D.; Michaud, D. [University of Wisconsin, Milwaukee, WI (United States)

2009-10-15T23:59:59.000Z

172

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

Science Conference Proceedings (OSTI)

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.

Izequeido, Alexandor

2001-04-01T23:59:59.000Z

173

Strip edge cracking simulation in cold rolling  

SciTech Connect

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.

Hubert, C.; Dubar, L.; Dubar, M.; Dubois, A. [Univ Lille Nord de France, F-59000 Lille (France); UVHC, TEMPO EA 4542, F-59313 Valenciennes (France)

2011-01-17T23:59:59.000Z

174

Assisted thermal stripping (ATS) for removal of PCBs from contaminated soils. Design of experiments modeling of the ATS process  

Science Conference Proceedings (OSTI)

In a companion report, the Assisted Thermal Stripping (ATS) process for enhanced removal of PCBs from PCB-contaminated soil is described. In studies directed toward achieving residual PCB levels of {le}2 ppm, it was found that four factors were particularly important -- (1) process temperature; (2) process time; (3) the amount of additive (for enhancing the removal of PCBs); and (4) steam flow rate. In order to optimize the ATS process, it was deemed crucial to ascertain the relative effect exerted by each of those process factors and the reproducibility of the process. To accomplish that, we have relied on the technique {open_quotes}Design of Experiments{close_quotes} (DOE) to mathematically model the ATS process. After considering the findings from our previous investigations, it was decided to employ formic acid as the additive for enhancing the removal of PCBs.

Krabbenhoft, H.O.; Webb, J.L.; Gascoyne, D.G. [GE Corporate Research & Development, Schenectady, NY (United States); Cawse, J.N. [GE Plastics, Pittsfield, MA (United States)

1996-12-31T23:59:59.000Z

175

Design, cost, and performance comparisons of several solar thermal systems for process heat. Volume III. Receivers  

DOE Green Energy (OSTI)

The receiver subsystem converts reflected solar radiation into thermal power by heating a working fluid. The objective of the task described was to estimate the cost and performance of the receiver subsystem for parabolic troughs, parabolic dishes, and central receivers over a wide range of temperatures and power levels for thermal power applications. This volume presents the fundamental design philosophy employed, the constraints identified, the tradeoffs performed and the cost and performance results obtained for each receiver in the study matrix.

Woodard, J.B. Jr.

1981-03-01T23:59:59.000Z

176

Modeling of thermally driven hydrological processes in partially saturated fractured rock  

E-Print Network (OSTI)

the dominant heat-transfer process. Because the multipleof coupled heat transfer and reactive transport processes inflow, heat transfer, and phase transformation processes

Tsang, Yvonne

2010-01-01T23:59:59.000Z

177

Determination of Thermal Contact Conductance of Metal Tabs for Battery Ultrasonic Welding Process  

SciTech Connect

A new experimental apparatus and data analysis algorithm were used to determine the thermal contact conductance between 0.2-mm-thick pure aluminum battery tabs as a function of contact pressure from 3.6 to 14.4 MPa. Specimens were sandwiched between one optically transparent and one infrared (IR) transparent glass windows, and heated up from one side by an intense short pulse of flash light. The temperature transient on the other side was measured by an IR camera. In order to determine the thermal contact conductance, two experiment configurations having different number of Al specimen layers were used. Numerical heat conduction simulations showed that the thermal contact conductance strongly depended on the ratio of the maximum temperature rise between the two configurations. Moreover, this ratio was not sensitive to the uncertainties of other thermal properties. Through the simulation results, a simple correlation between the gap conductance and the ratio was established. Therefore, once the ratio of the temperature rise between two configurations was experimentally measured, the thermal contact conductance could be readily determined from the correlation. The new method was fast and robust. Most importantly, the data analysis algorithm improved the measurement accuracy by considerably reducing the uncertainties associated with the thermophysical properties of materials and measurement system.

Chen, Jian [ORNL; Zhang, Wei [ORNL; Yu, Zhenzhen [ORNL; Feng, Zhili [ORNL

2012-01-01T23:59:59.000Z

178

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

SciTech Connect

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

Korinko, P.; Golyski, M.

2013-11-01T23:59:59.000Z

179

Enhanced-oil-recovery thermal processes, annex IV. Venezuela-MEM/USA-DOE fossil-energy report IV-1  

Science Conference Proceedings (OSTI)

The Agreement between the United States and Venezuela was designed to further energy research and development in six areas. This report focuses on Annex IV - Enhanced-Oil-Recovery Thermal Processes which was divided into seven tasks. This report will discuss the information developed within Task I related to the Department of Energy providing data on the performance of insulated oil-well tubulars. Surface generated steam has been traditionally used in thermal enhanced oil recovery processes. In past years the tubing through which the steam is injected into the reservoir has been bare with relatively high heat losses. In recent years however various materials and designs for insulating the tubing to reduce heat losses have been developed. Evaluation of several of these designs in an instrumented test tower and in an oil field test environment was undertaken. These tests and the resulting data are presented.

Peterson, G.; Schwartz, E.

1983-04-01T23:59:59.000Z

180

Improved electrical transport properties in p-type ZnO film by Rapid Dark thermal annealing process  

SciTech Connect

A rapid dark thermal annealing process at 800 deg. C of radio frequency sputtered P doped ZnO thin films have resulted in improved electrical transport properties with hole concentration of 1 x 1018 cm-3, mobility 4.37 cm2/Vs and resistivity 1.4 {Omega}-cm. X-ray photoelectron spectroscopy shows the presence of inactivated P in as-grown ZnO films.

Ghosh, Tushar; Basak, Durga [Department of Solid State Physics, Indian Association for the Cultivation of science, Jadavpur, Kolkata-700032 (India)

2012-06-05T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Analysis of Crack Growth Data  

Science Conference Proceedings (OSTI)

Table 3   Methods for calculating crack growth rates...the derivative at the midpoint of a data set. These methods use

182

Environmentally Assisted Cracking of Materials  

Science Conference Proceedings (OSTI)

In-Situ Repairs of Oil Industry Pipelines, Tanks and Vessels by Welding Using Metal Arc Welding Under Oil (MAW-UO) · Interpretation of Crack Initiation and ...

183

Environmentally Assisted Cracking of Materials  

Science Conference Proceedings (OSTI)

Development of Alternating Current Potential Drop (ACPD) method for the detection of Primary Water Stress Corrosion Cracking initiation in Stainless Steels and ...

184

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

Science Conference Proceedings (OSTI)

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.

Heilman, J.E. [Carpenter Technology Corp., Reading, PA (United States); Damkroger, B.K. [Sandia National Labs., Albuquerque, NM (United States)

1994-09-01T23:59:59.000Z

185

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

SciTech Connect

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-tip structures- chemistries will be highlighted comparing Fe-base 316/304SS to Ni-base alloy 600/182 and for tests in oxidizing versus hydrogenated water environments.

Bruemmer, Stephen M.; Thomas, Larry E.

2010-04-05T23:59:59.000Z

186

In-flight particle pyrometer for thermal spray processes. Final report, October 1, 1992--December 31, 1994  

SciTech Connect

The objective of the project was to produce an industrial hardened particle temperature sensor. In general the thermal spray community believes that the particle temperature and velocity prior to impact on the substrate are two of the predominant parameters which effect coating quality. Prior to the full scale prototyping of such an instrument it was necessary to firmly establish the relationship between operating parameters, particle temperature and coating characteristics. It was shown in the first year of this project that the characteristics and consistency of the coatings formed are directly determined by particle velocity and temperature at impact. For the HVOF spray process the authors have also shown that the particle velocity is determined primarily by chamber pressure, while stoichiometry (the ratio of oxygen to fuel) has a minor influence. Hence, particle velocity can be controlled by maintaining the chamber pressure at a set point. Particle temperature, on the other hand is primarily a function of stoichiometry. Therefore particle velocity and temperature can be independently controlled. In the second year (FY-94), an industrial hardened prototype particle temperature sensor (In-flight Particle Pyrometer) was produced. The IPP is a two-color radiation pyrometer incorporating improvements which make the device applicable to the measurement of in-flight temperature of particles over a wide range of operating conditions in thermal spray processes. The device is insensitive to particulate loading (particle feed rate), particle composition, particle size distribution, and provides an ensemble average particle temperature. The sensor head is compact and coupled to the electronics via a fiber optic cable. Fiber optic coupling allows maximum flexibility of deployment while providing isolation of the electronics from electromagnetic interference and the hot, particulate laden environment of a typical spray booth. The device is applicable to all thermal spray processes, including plasma spray, HVOF, twin wire arc, and liquid metal fed processes, as well as other more conventional high temperature processes such as crucible or hearth melting.

1995-02-20T23:59:59.000Z

187

Structures for dense, crack free thin films  

DOE Patents (OSTI)

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.

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

2011-03-08T23:59:59.000Z

188

Reliability Centered Lifetime Prediction of Environmentally Assisted Cracking  

Science Conference Proceedings (OSTI)

This report describes the results of joint research sponsored by EPRI in cooperation with Tohoku University and a number of Japanese organizations to address the issue of environmentally assisted cracking (EAC) in boiling water reactors (BWRs) and pressurized water reactors (PWRs). The term EAC includes intergranular stress corrosion cracking and corrosion fatigue. The goal of this project was to develop a fundamental understanding of processes controlling EAC of stainless steels and nickel-base alloys i...

2003-09-02T23:59:59.000Z

189

Hydrogen sulfide stress corrosion cracking in materials for geothermal power  

DOE Green Energy (OSTI)

Studies to evaluate the performance of alloys used in geothermal power systems are reported. Alloys which are commercially available and those which have modified metallurgical structures and/or composition modifications were tested to determine the corrosive effects of the H/sub 2/S and thermal environments in geothermal fluids. Hydrogen embrittlement and sulfide stress corrosion cracking were tested. Test results showing the effects of alloy composition, tempering temperatures, fluid temperature and salt content, and ageing on sulfide stress cracking are tabulated. (LCL)

Hehemann, R.F.; Troiano, A.R.; Abu-Khater, B.; Ferrigno, S.

1976-01-01T23:59:59.000Z

190

THE NON-CONSTANT CTOD/CTOA IN CRACK PROPAGATION  

SciTech Connect

Unlike the common belief that crack propagation behavior can be predicted successfully by employing fracture criteria based on a constant crack tip opening displacement or angle (CTOD/CTOA), this paper shows that the initially non-constant portion of the CTOD/CTOA plays an essential role in predicting the fracture load for a growing crack. Three- and two-dimensional finite element analyses indicate that a severe underestimate of the experimental load vs. crack extension curve would occur if a constant CTOD/CTOA criterion is used. However, the use of a simplified, bilinear CTOD/CTOA criterion including its non-constant portion will closely duplicate the test data. Furthermore, as a result of using the experimental data from J-integral test with various crack length to specimen width ratios (a/W), it is demonstrated that the CTOD/CTOA is crack tip constraint dependent. The initially higher values of the CTOD/CTOA are in fact a natural consequence of crack growth process which is refl ected by the J-resistance curve and its slope (tearing modulus).

LAM, POH-SANG

2004-07-19T23:59:59.000Z

191

Hydrogen-Induced Cracking of the Drip Shield  

DOE Green Energy (OSTI)

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]).

F. Hua

2004-09-07T23:59:59.000Z

192

Optimization studies on thermal and mechanical manufacturing processes for multifilament superconducting tape and wire  

E-Print Network (OSTI)

There are many parameters that significantly affect the electrical performance of ceramic-core superconducting composite wire and tapes, which remain ambiguous and require more labor on their optimization. BSCCO 2212 has not been paid the attention and investment it deserves. In this regard, all optimization efforts were made for BSCCO 2223. In our work, a practical and inexpensive manufacturing method, thermally and mechanically optimized for Pb doped BiSrCaCuO 2212 superconducting multifilament (38 filaments) wires and tapes, was successfully employed. Optimized parameters can be classified under material, mechanical (deformation) and heat treatment (thermal) subgroups. Parameters involved with materials included investigation of deformation behavior of two different sheath metals; pure silver and 0.02% magnesia dispersion reinforced silver alloy. Pb doped BiSrCaCuO 2212 ceramic superconductor powder, the other source of material related parameters, was synthesized following the "Thermal Co-decomposition or Wet Mix" method. Fabrication of mono and multifilament wires with Oxide Powder in Tube (OPIT) method followed next. Optimization of drawing deformation was practiced to achieve the best ceramic grain alignment and smoother ceramic powder core/metal sheath interface in order to avoid "sausaging" in wires. Rolling of the wire products into tapes by following different deformation regimes was the other manufacturing stage of the project. Variable and constant reduction-per-pass deformation paths were employed to reveal their effects on our composites with distinct sheath material and filament formation. The search for the best (optimum) heat treatment schedule for our Bi2212 superconductor composites, a modified version of "step solidification partial melting", was employed successfully. A solution through tried recipes for the bubbling problem that occurred with our tapes was also addressed. Electrical performance tests of fully reacted wires were carried out in our laboratory and very promising results were attained.

Basaran, Burak

2003-08-01T23:59:59.000Z

193

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

SciTech Connect

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.

Dumin, Yurii V., E-mail: dumin@yahoo.com, E-mail: dumin@izmiran.ru [Institute of Terrestrial Magnetism, Ionosphere, and Radio Wave Propagation (IZMIRAN), Russian Academy of Sciences, Troitsk, Moscow reg., 142190 (Russian Federation)

2012-05-20T23:59:59.000Z

194

Hydrogen Induced Cracking of Drip Shield  

DOE Green Energy (OSTI)

One potential failure mechanism for titanium and its alloys under repository conditions is via the absorption of atomic hydrogen in the metal crystal lattice. The resulting decreased ductility and fracture toughness may lead to brittle mechanical fracture called hydrogen-induced cracking (HIC) or hydrogen embrittlement. For the current design of the engineered barrier without backfill, HIC may be a problem since 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 scientific analysis and modeling activity is to evaluate whether the drip shield will fail by HIC or not under repository conditions within 10,000 years of emplacement. This Analysis and Model Report (AMR) addresses features, events, and processes related to hydrogen induced cracking of the drip shield. REV 00 of this AMR served as a feed to ''Waste Package Degradation Process Model Report'' and was developed in accordance with the activity section ''Hydrogen Induced Cracking of Drip Shield'' of the development plan entitled ''Analysis and Model Reports to Support Waste Package PMR'' (CRWMS M&O 1999a). This AMR, prepared according to ''Technical Work Plan for: Waste Package Materials Data Analyses and Modeling'' (BSC 2002), is to feed the License Application.

G. De

2003-02-24T23:59:59.000Z

195

Cracked shaft detection and diagnostics: A literature review  

E-Print Network (OSTI)

ABSTRACT—Cracks in shafts have long been identified as factors limiting the safe and reliable operation of turbomachines. They can sometimes result in catastrophic failure of equipment (rotor bursts) and, more often, in costly process upsets, repairs and premature scrapping and replacement of equipment. Cracked shafts still pose a significant and real threat to equipment in spite of the great advances made in the areas of metallurgy, manufacturing and design. In the past two decades, much research and many resources have gone into developing various on-line and off-line diagnostic techniques to effectively detect cracks before they cause serious damage. Because of the enormous amount of ongoing research in this area (more than 500 technical papers have been published in English alone in the past 30 years), there is a real need to periodically condense and summarize the information. This paper reviews literature on cracked shaft detection and diagnostics published after 1990.

Giridhar Sabnavis; R. Gordon Kirk; Mary Kasarda; Dane Quinn; Giridhar Sabnavis; R. Gordon Kirk; Mary Kasarda; Dane Quinn

2004-01-01T23:59:59.000Z

196

Plasma-Thermal Synthesis  

INL’s Plasma-Thermal Synthesis process improves the conversion process for natural gas into liquid hydrocarbon fuels.

197

MATERIALS, COATINGS AND PROCESSES FOR IMPROVED ...  

Science Conference Proceedings (OSTI)

Life prediction method for gas turbine nozzles was discussed. In gas turbine nozzles, crackings due to cyclic thermal strain generating with start-up and ...

198

Retrieval of Thermal and Microphysical Variables in Observed Convective Storms. Part II: Sensitivity of Cloud Processes to Variation of the Microphysical Parameterization  

Science Conference Proceedings (OSTI)

The hydrometeor content and thermal fields in a thunderstorm are estimated from a three-dimensional kinematic cloud model employing Doppler wind fields and parameterized microphysical processes. The sensitivity of the cloud model calculations to ...

Conrad L. Ziegler

1988-03-01T23:59:59.000Z

199

Heating the Solar Atmosphere by the Self-Enhanced Thermal Waves Caused by the Dynamo Processes  

E-Print Network (OSTI)

We discuss a possible mechanism for heating the solar chromosphere and lower part of the transition region by the ensemble of thermal waves, generated by the photospheric dynamo and propagating upwards 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 gyro- frequencies, 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 an order of magnitude, i.e. it may be responsible for heating the chromosphere and the lower part of the transition region.

Dumin, Yurii V

2012-01-01T23:59:59.000Z

200

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

DOE Green Energy (OSTI)

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.

Gorensek, M

2007-03-16T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Stress corrosion cracking of austenitic stainless steel core internal welds.  

SciTech Connect

Microstructural analyses by several advanced metallographic techniques were conducted on austenitic stainless steel mockup and core shroud welds that had cracked in boiling water reactors. Contrary to previous beliefs, heat-affected zones of the cracked Type 304L, as well as 304 SS core shroud welds and mockup shielded-metal-arc welds, were free of grain-boundary carbides, which shows that core shroud failure cannot be explained by classical intergranular stress corrosion cracking. Neither martensite nor delta-ferrite films were present on the grain boundaries. However, as a result of exposure to welding fumes, the heat-affected zones of the core shroud welds were significantly contaminated by oxygen and fluorine, which migrate to grain boundaries. Significant oxygen contamination seems to promote fluorine contamination and suppress thermal sensitization. Results of slow-strain-rate tensile tests also indicate that fluorine exacerbates the susceptibility of irradiated steels to intergranular stress corrosion cracking. These observations, combined with previous reports on the strong influence of weld flux, indicate that oxygen and fluorine contamination and fluorine-catalyzed stress corrosion play a major role in cracking of core shroud welds.

Chung, H. M.; Park, J.-H.; Ruther, W. E.; Sanecki, J. E.; Strain, R. V.; Zaluzec, N. J.

1999-04-14T23:59:59.000Z

202

Near net shape processing for solar thermal propulsion hardware using directed light fabrication  

DOE Green Energy (OSTI)

Directed light fabrication (DLF) is a direct metal deposition process that fuses gas delivered powder, in the focal zone of a high powered laser beam to form fully fused near net shaped components. The near net shape processing of rhenium, tungsten, iridium and other high temperature materials may offer significant cost savings compared with conventional processing. This paper describes a 3D parametric solid model, integrated with a manufacturing model, and creating a control field which runs on the DLF machine directly depositing a fully dense, solid metal, near net shaped, nozzle component. Examples of DLF deposited rhenium, iridium and tantalum, from previous work, show a continuously solidified microstructure in rod and tube shapes. Entrapped porosity indicates the required direction for continued process development. These combined results demonstrate the potential for a new method to fabricate complex near net shaped components using materials of interest to the space and aerospace industries.

Milewski, J.O. [Los Alamos National Lab., NM (United States). Materials Science and Technology Div.; Fonseca, J.C.; Lewis, G.K. [SyntheMet Corp., Los Alamos, NM (United States)

1998-12-01T23:59:59.000Z

203

Intergranular Stress Corrosion Cracking (IGSCC) Mechanism of ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2012. Symposium, Environmentally Assisted Cracking of Materials. Presentation Title ...

204

Weldability Tests for Evaluating Cracking Susceptibility  

Science Conference Proceedings (OSTI)

Table 2   Weldability tests used to evaluate susceptibility to cracking...used to evaluate susceptibility to cracking Test Fields of use Controllable variables Type of data Specialized equipment Relative cost Lehigh restraint test Weld metal hot and cold cracking, root cracking,

205

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

DOE Patents (OSTI)

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.

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

2003-01-01T23:59:59.000Z

206

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

DOE Green Energy (OSTI)

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.

Lyon, Richard

2001-08-05T23:59:59.000Z

207

THERMAL PROPERTIES AND PROCESSES D Hillel, Columbia University, New York, NY, USA  

E-Print Network (OSTI)

be the infiltration of warm waste water (from, e.g., a power plant) into an initially cold soil. Conduction, the third influences biological processes such as seed germination, seedling emergence and growth, root development- lengths, is proportional to the fourth power of the absolute temperature Tof the body's surface. This law

208

Stable crack growth estimates based on effective crack length and crack-opening displacements  

SciTech Connect

A method was developed for estimating the amount of stable crack growth that has occurred in a fracture toughness specimen that were loaded into the plastic range and for which only a monotonically increasing load-displacement curve was measured. The method was applied to data from several pressure vessel steels. The resulting J vs ..delta..a values compare favorably with a resistance curve obtained by the multiple specimen heat-tinting technique for A533, Grade B, Class 1 steel. The method for estimating stable crack growth uses several existing concepts heretofore mainly used separately. These concepts include an approximate expression for J for the compact specimen proposed by Andrews, the effective crack length concept of McCabe and Landes, the UK representation of the crack profile as a pair of straight lines intersecting at a hinge point, and Well's expression, J = m sigma/sub y/delta, for relating the crack-opening displacement to the value of J. The value of the constraint factor, m, at the advancing crack tip is estimated by means of a relation between ductility and fracture toughness. When calculated with respect to the COD at the original fatigue crack tip, the constraint factor, m/sub o/, is found to have a value consistently close to 2.0 for compact and precracked Charpy specimens. The method of estimation requires no auxiliary load-deflection measurements or calculations, and so permits single specimen estimates of stable crack growth to be made without the necessity of making high precision unloading compliance measurements.

Merkle, J.G.; Hudson, C.E.

1979-01-01T23:59:59.000Z

209

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

Science Conference Proceedings (OSTI)

Mercury has had various uses in nuclear fuel reprocessing and other nuclear processes, and so is often present in radioactive and mixed (radioactive and hazardous) wastes. Test programs performed in recent years have shown that mercury in off-gas streams from processes that treat radioactive wastes can be controlled using fixed beds of activated sulfur-impregnated carbon, to levels low enough to comply with air emission regulations such as the Hazardous Waste Combustor (HWC) Maximum Achievable Control Technology (MACT) standards. Carbon bed hot spots or fires have occurred several times during these tests, and also during a remediation of tanks that contained mixed waste. Hot spots occur when localized areas in a carbon bed become heated to temperatures where oxidation occurs. This heating typically occurs due to heat of absoption of gas species onto the carbon, but it can also be caused through external means such as external heaters used to heat the carbon bed vessel. Hot spots, if not promptly mitigated, can grow into bed fires. Carbon bed hot spots and fires must be avoided in processes that treat radioactive and mixed waste. Hot spots are detected by (a) monitoring in-bed and bed outlet gas temperatures, and (b) more important, monitoring of bed outlet gas CO concentrations. Hot spots are mitigated by (a) designing for appropriate in-bed gas velocity, for avoiding gas flow maldistribution, and for sufficient but not excessive bed depth, (b) appropriate monitoring and control of gas and bed temperatures and compositions, and (c) prompt implementation of corrective actions if bed hot spots are detected. Corrective actions must be implemented quickly if bed hot spots are detected, using a graded approach and sequence starting with corrective actions that are simple, quick, cause the least impact to the process, and are easiest to recover from.

Nick Soelberg; Joe Enneking

2011-05-01T23:59:59.000Z

210

Aspects of Stress Corrosion Cracking Relevant to Irradiation-Assisted Stress Corrosion Cracking (IASCC)  

Science Conference Proceedings (OSTI)

This report provides a comprehensive survey of crack initiation issues in irradiation-assisted stress corrosion cracking (IASCC). It considers microcracking on smooth specimens and the transition from microcracking to stable crack propagation.

2002-05-02T23:59:59.000Z

211

Thermal spray coatings: New materials, processes and applications; Proceedings of the Second National Conference on Thermal Spray, Long Beach, CA, October 31-November 2, 1984  

SciTech Connect

Thermal-spray-coating techniques and their applications are discussed in reviews and reports of laboratory experiments and industrial experience. Topics explored include the future of thermal spraying, plasma-sprayed bonding coats for plastic substrates, plasma-spray deposition of hollow-particle ceramic powders, volumetric-feed-back powder-feed controllers, metal sprayed coating systems onboard U.S. Navy ships, high-performance plasma-sprayed coatings, and arc-coating technology and equipment. Consideration is given to cavitation-erosion of plasma-sprayed alloys, statistical methods of plasma-spray parameter testing, NDE of surface coatings by photothermal imaging, NDE of thermal-spray-coating bonds, and diamond-wheel grinding of thermal-spray materials.

Longo, F.N.

1985-01-01T23:59:59.000Z

212

On the micromechanisms of fatigue-crack propagation in aluminum- lithium alloys: Sheet vs. plate material  

Science Conference Proceedings (OSTI)

Micromechanisms influencing the propagation of long (>10 mm) fatigue cracks in aluminum-lithium alloys are examined by specifically comparing crack-growth kinetics in a peak-aged Al-Li-Cu-Zr alloy 2090, processed as 1.6-mm thin (T83) sheet and 12.7-mm thick (T81) plate. It is found that in general crack-growth rates are significantly faster in the sheet material at equivalent stress-intensity levels, due to differences in the role of crack-tip shielding, resulting from crack deflection and consequent crack closure from wedging of fracture-surface asperities. Microstructurally, such differences are related to variations in the degree of recrystallization, grain structure and deformation texture in the two wrought-product forms. 14 refs., 4 figs.

Rao Venkateswara, K.T.; Ritchie, R.O. (Lawrence Berkeley Lab., CA (United States) California Univ., Berkeley, CA (United States). Dept. of Materials Science and Mineral Engineering); Bucci, R.J. (Aluminum Co. of America, Alcoa Center, PA (United States). Alcoa Labs.)

1989-12-01T23:59:59.000Z

213

Weld solidification cracking in 304 to 204L stainless steel  

Science Conference Proceedings (OSTI)

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.

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

2010-09-15T23:59:59.000Z

214

Weld solidification cracking in 304 to 304L stainless steel  

Science Conference Proceedings (OSTI)

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.

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

2010-01-01T23:59:59.000Z

215

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

DOE Patents (OSTI)

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.

Sarin, V.K.

1990-08-21T23:59:59.000Z

216

Predicting the Behavior of Small Fatigue Cracks - Programmaster.org  

Science Conference Proceedings (OSTI)

are effective at providing crack propagation resistance in many materials and composites, these mechanisms result in a crack size dependence (i.e., “small crack ...

217

Influence of Radiolysis and Hydrogen Embrittlement on the In-Service Cracking of PWR Internal Structures  

Science Conference Proceedings (OSTI)

Irradiation-assisted stress corrosion cracking (IASCC) of austenitic stainless steel components exposed to a high neutron flux in light water reactors is becoming an increasing concern for nuclear power plant owners. This study investigates the interaction between hydrogen in the metal and the water environment that may exacerbate the cracking process in PWRs.

1999-11-10T23:59:59.000Z

218

Prediction of Environmental Crack Growth in Nuclear Power Plant Components: Volumes 1-3  

Science Conference Proceedings (OSTI)

In-service assessment of crack growth rates plays a crucial role in decisions involving component integrity and life. The research presented in this three-volume report examines many important aspects of the crack tip damage processes in aqueous environments, providing an improved scientific basis for life prediction technology development.

1993-11-04T23:59:59.000Z

219

Thermal plasma processing of materials. Progress report, September 1, 1988--January 31, 1992  

SciTech Connect

Emphasis has been on plasma synthesis of fine powders, plasma Chemical Vapor Deposition (CVD), on related diagnostics, and on modeling work. Since plasma synthesis as well as plasma CVD make frequent use of plasma jets, the beginning has been devoted of plasma jets and behavior of particulates injected into such plasma jets. Although most of the construction of the Triple-Torch Plasma Reactor (TTPR) has already been done, modifications have been made in particular modifications required for plasma CVD of diamond. A new reactor designed for Counter-Flow Liquid Injection Plasma Synthesis (CFLIPS) proved to be an excellent tool for synthesis of fine powders as well as for plasma CVD. An attempt was made to model flow and temperature fields in this reactor. Substantial efforts were made to single out those parameters which govern particle size, size distribution, and powder quality in our plasma synthesis experiments. This knowledge is crucial for controlling the process and for meaningful diagnostics and modeling work. Plasma CVD of diamond films using both reactors has been very successful and we have been approached by a number of companies interested in using this technology for coating of tools.

Pfender, E.; Heberlein, J.

1992-02-01T23:59:59.000Z

220

Modeling shear failure and permeability enhancement due to coupled Thermal-Hydrological-Mechanical processes in Enhanced Geothermal Reservoirs  

Science Conference Proceedings (OSTI)

The connectivity and accessible surface area of flowing fractures, whether natural or man-made, is possibly the single most important factor, after temperature, which determines the feasibility of an Enhanced Geothermal System (EGS). Rock deformation and in-situ stress changes induced by injected fluids can lead to shear failure on preexisting fractures which can generate microseismic events, and also enhance the permeability and accessible surface area of the geothermal formation. Hence, the ability to accurately model the coupled thermal-hydrologic-mechanical (THM) processes in fractured geological formations is critical in effective EGS reservoir development and management strategies. The locations of the microseismic events can serve as indicators of the zones of enhanced permeability, thus providing vital information for verification of the coupled THM models. We will describe a general purpose computational code, FEHM, developed for this purpose, that models coupled THM processes during multiphase fluid flow and transport in fractured porous media. The code incorporates several models of fracture aperture and stress behavior combined with permeability relationships. We provide field scale examples of applications to geothermal systems to demonstrate the utility of the method.

Kelkar, Sharad [Los Alamos National Laboratory

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Generation of ELF and VLF waves by HF-modulated polar electrojet via a thermal instability process  

SciTech Connect

Generation of ELF and VLF waves via a thermal instability process in a HF-modulated polar electrojet has been investigated. It is shown that a positive feedback through the electron-neutral collisional heating process can cause the transient response of the plasma to the modulated HF heater to grow exponentially. The threshold fields of the instability under normal electrojet conditions are found to be about 2.25 V/m and 1.13 V/m for the operation of the o-mode and x-mode heaters with a 50% duty cycle, respectively. For a heater wave field of, e.g., 1.5 V/m, the instability can be excited by the x-mode heater within a few tens of millisecond. The predicted dependence of the ELF/VLF radiation amplitude on the percentage of the duty cycle of the HF modulation is identical to that of the recent observational results of Barr and Stubbe. 28 refs., 2 figs.

Kuo, S.P. (Polytechnic Univ., Farmingdale, NY (United States)); Lee, M.C. (Massachusetts Inst. of Technology, Cambridge (United States))

1993-02-05T23:59:59.000Z

222

Supporting technology for enhanced oil recovery: Third ammendment and extension to Annex IV enhanced oil recovery thermal processes  

Science Conference Proceedings (OSTI)

This report contains the results of efforts under the seven tasks of the Third 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 tasks) and each section contains one or more reports prepared by various individuals or groups describing the results of effort 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 25 through 31. The first, second, and third reports on Annex IV, ((Venezuela-MEM/USA-DOE Fossil Energy Report IV-1, IV-2, and IV-3 (DOE/BETC/SP-83/15, DOE/BC-84/6/SP, and DOE/BC-86/2/SP)) contain the results from the first 24 tasks. Those reports are dated April 1983, August 1984, and March 1986. Selected papers have been processed for inclusion in the Energy Data Base.

Peterson, G.; Munoz, J.D.

1987-07-01T23:59:59.000Z

223

Technical progress and community relations activities for the fluidized bed thermal treatment process at the Rocky Flats Plant  

SciTech Connect

A fluidized bed system is being developed at Rocky Flats for the treatment of mixed waste (a mixture of radioactive and chemically hazardous waste). The current program builds on experience gained in the 1970's and 1980's in tests with bench-scale, pilot-scale, and demonstration-scale fluidized bed incinerators. Rocky Flat's fluidized bed system operates at low temperatures ([approximately]525--600[degrees]C) which eliminates many of the disadvantages associated with high temperature thermal treatment processes. The bed makes use of in situ neutralization of acidic off-gases by incorporating either sodium carbonate or a mixture of sodium carbonate and bicarbonate (Trona) in the bed media. This obviates using wet scrubbers to treat the off-gas. It is expected that once in production, the fluidized bed process will yield up to a 40:1 reduction in the volume of the waste feed. The current development program for the full-scale system is a nationwide effort incorporating input from national laboratories, universities, regulatory agencies, and private companies to assure the most current technology is utilized and that regulatory concerns are addressed. In addition to resolving technological issues, the fluidized bed program is addressing public concerns with a proactive community relations program.

Semones, G.B.; Williams, P.M.; Stiefvater, S.P.; Mitchell, D.L.; Roecker, B.D.

1993-01-01T23:59:59.000Z

224

Technical progress and community relations activities for the fluidized bed thermal treatment process at the Rocky Flats Plant  

SciTech Connect

A fluidized bed system is being developed at Rocky Flats for the treatment of mixed waste (a mixture of radioactive and chemically hazardous waste). The current program builds on experience gained in the 1970`s and 1980`s in tests with bench-scale, pilot-scale, and demonstration-scale fluidized bed incinerators. Rocky Flat`s fluidized bed system operates at low temperatures ({approximately}525--600{degrees}C) which eliminates many of the disadvantages associated with high temperature thermal treatment processes. The bed makes use of in situ neutralization of acidic off-gases by incorporating either sodium carbonate or a mixture of sodium carbonate and bicarbonate (Trona) in the bed media. This obviates using wet scrubbers to treat the off-gas. It is expected that once in production, the fluidized bed process will yield up to a 40:1 reduction in the volume of the waste feed. The current development program for the full-scale system is a nationwide effort incorporating input from national laboratories, universities, regulatory agencies, and private companies to assure the most current technology is utilized and that regulatory concerns are addressed. In addition to resolving technological issues, the fluidized bed program is addressing public concerns with a proactive community relations program.

Semones, G.B.; Williams, P.M.; Stiefvater, S.P.; Mitchell, D.L.; Roecker, B.D.

1993-01-01T23:59:59.000Z

225

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

SciTech Connect

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.

Salmiaton, A., E-mail: mie@eng.upm.edu.my [Department of Chemical and Environmental Engineering, Faculty of Engineering, Universiti Putra Malaysia (UPM), 43400 UPM Serdang, Selangor (Malaysia); Garforth, A.A. [School of Chemical Engineering and Analytical Science, University of Manchester, P.O. Box 88, Sackville Street, Manchester M60 1QD (United Kingdom)

2011-06-15T23:59:59.000Z

226

Cessation of environmentally-assisted cracking in a low-alloy steel: Experimental results  

SciTech Connect

The presence of dissolved metallurgical sulfides in pressure vessel and piping steels has been linked to Environmentally-Assisted Cracking (EAC), a phenomenon observed in laboratory tests that results in fatigue crack growth rates as high as 100 times that in air. Previous experimental and analytical work based on diffusion as the mass transport process has shown that surface cracks that are initially clean of sulfides will not initiate EAC in most applications. This is because the average crack tip velocity would not be sufficiently high to expose enough metallurgical sulfides per unit time and produce the sulfide concentration required for EAC. However, there is a potential concern for the case of a relatively large embedded crack breaking through to the wetted surface. Such a crack would not be initially clean of sulfides, and EAC could initiate. This paper presents the results of a series of experiments conducted on two heats of an EAC susceptible, high-sulfur, low-alloy steel in 243{degrees}C low-oxygen water to further study the phenomenon of EAC persistence at low crack tip velocities. A load cycle profile that incorporated a significant load dwell period at minimum load was used. In one experiment, the fatigue cycling history was such that relatively high crack tip velocities at the start of the experiment produced a persistent case of EAC even when crack tip velocities were later reduced to levels below the EAC initiation velocity. The other series of experiments used initial crack tip velocities that were much lower and probably more realistic. Air precracking of the compact tension specimens produced an initial inventory of undissolved sulfides on the crack flanks that directly simulates the array of sulfides expected from the breakthrough of an embedded crack. In all cases, results showed EAC ceased after several hundred hours of cycling.

Li, Y.Y.

1997-01-01T23:59:59.000Z

227

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

Science Conference Proceedings (OSTI)

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.

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

2003-10-31T23:59:59.000Z

228

Intergranular Cracking of Brass Sprinkler Heads  

Science Conference Proceedings (OSTI)

Symposium, Charles R. Morin Memorial Symposium on Failure Analysis and Prevention. Presentation Title, Intergranular Cracking of Brass Sprinkler Heads.

229

A multi-criteria assessment of scenarios on thermal processing of infectious hospital wastes: A case study for Central Macedonia  

Science Conference Proceedings (OSTI)

In Greece more than 14,000 tonnes of infectious hospital waste are produced yearly; a significant part of it is still mismanaged. Only one off-site licensed incineration facility for hospital wastes is in operation, with the remaining of the market covered by various hydroclave and autoclave units, whereas numerous problems are still generally encountered regarding waste segregation, collection, transportation and management, as well as often excessive entailed costs. Everyday practices still include dumping the majority of solid hospital waste into household disposal sites and landfills after sterilization, still largely without any preceding recycling and separation steps. Discussed in the present paper are the implemented and future treatment practices of infectious hospital wastes in Central Macedonia; produced quantities are reviewed, actual treatment costs are addressed critically, whereas the overall situation in Greece is discussed. Moreover, thermal treatment processes that could be applied for the treatment of infectious hospital wastes in the region are assessed via the multi-criteria decision method Analytic Hierarchy Process. Furthermore, a sensitivity analysis was performed and the analysis demonstrated that a centralized autoclave or hydroclave plant near Thessaloniki is the best performing option, depending however on the selection and weighing of criteria of the multi-criteria process. Moreover the study found that a common treatment option for the treatment of all infectious hospital wastes produced in the Region of Central Macedonia, could offer cost and environmental benefits. In general the multi-criteria decision method, as well as the conclusions and remarks of this study can be used as a basis for future planning and anticipation of the needs for investments in the area of medical waste management.

Karagiannidis, A. [Laboratory of Heat Transfer and Environmental Engineering, Aristotle University of Thessaloniki, Box 483, GR-54124 Thessaloniki (Greece); Papageorgiou, A., E-mail: apapa@auth.g [Laboratory of Heat Transfer and Environmental Engineering, Aristotle University of Thessaloniki, Box 483, GR-54124 Thessaloniki (Greece); Perkoulidis, G. [Laboratory of Heat Transfer and Environmental Engineering, Aristotle University of Thessaloniki, Box 483, GR-54124 Thessaloniki (Greece); Sanida, G. [3rd Health Region Administration (Macedonia), 16 Aristotelous Str, GR-54623 Thessaloniki (Greece); Samaras, P. [Technological Education Institution of West Macedonia, Department of Pollution Control Technologies, 50100 Kozani (Greece)

2010-02-15T23:59:59.000Z

230

Catalytic cracking. (Latest citations from the Compendex database). Published Search  

Science Conference Proceedings (OSTI)

The bibliography contains citations concerning applications of catalytic cracking processes in fluidized bed systems, moving beds, refineries, vacuum distillations, and reformers. Design aspects, modeling, control systems, and operating procedures are also discussed. (Contains a minimum of 149 citations and includes a subject term index and title list.)

Not Available

1993-07-01T23:59:59.000Z

231

Stress Corrosion Cracking of Brass: A Comparative Study on ...  

Science Conference Proceedings (OSTI)

Environmentally Assisted Cracking of Carbon Steel in High Temperature Geothermal Well · Evaluation of the Susceptibility to Hydrogen Assisted Cracking in ...

232

Environmental Effects on Fatigue Crack Growth Rates in Sour ...  

Science Conference Proceedings (OSTI)

Environmentally Assisted Cracking of Carbon Steel in High Temperature Geothermal Well · Evaluation of the Susceptibility to Hydrogen Assisted Cracking in ...

233

Environmental Cracking Resistance of High Nickel Alloys (CRAs  

Science Conference Proceedings (OSTI)

Environmentally Assisted Cracking of Carbon Steel in High Temperature Geothermal Well · Evaluation of the Susceptibility to Hydrogen Assisted Cracking in ...

234

On Modeling Hydrogen-Induced Intergranular Cracking under ...  

Science Conference Proceedings (OSTI)

Environmentally Assisted Cracking of Carbon Steel in High Temperature Geothermal Well · Evaluation of the Susceptibility to Hydrogen Assisted Cracking in ...

235

Corrosion and Cracking of Carbon Steel in Fuel Grade Ethanol  

Science Conference Proceedings (OSTI)

Environmentally Assisted Cracking of Carbon Steel in High Temperature Geothermal Well · Evaluation of the Susceptibility to Hydrogen Assisted Cracking in ...

236

Evaluation of the Susceptibility to Hydrogen Assisted Cracking in ...  

Science Conference Proceedings (OSTI)

Environmentally Assisted Cracking of Carbon Steel in High Temperature Geothermal Well · Evaluation of the Susceptibility to Hydrogen Assisted Cracking in ...

237

On the Fatigue Crack Propagation Behavior of Superalloys at ...  

Science Conference Proceedings (OSTI)

ON THE FATIGUE CRACK PROPAGATION BEHAVIOR. OF SUPERALLOYS AT ... the FCP resistance of superalloys ... lead to poor crack propagation behavior.

238

Assessment of Cracks in Stress Concentration Regions with Localized Plastic Zones  

SciTech Connect

Marty brittle fracture evaluation procedures include plasticity corrections to elastically computed stress intensity factors. These corrections, which are based on the existence of a plastic zone in the vicinity of the crack tip, can overestimate the plasticity effect for a crack embedded in a stress concentration region in which the elastically computed stress exceeds the yield strength of the material in a localized zone. The interactions between the crack, which acts to relieve the high stresses driving the crack, plasticity effects in the stress concentration region, and the nature and source of the loading are examined by formulating explicit flaw finite element models for a crack emanating from the root of a notch located in a panel subject to an applied tensile stress. The results of these calculations provide conditions under which a crack-tip plasticity correction based on the Irwin plastic zone size overestimates the plasticity effect. A failure assessment diagram (FAD) curve is used to characterize the effect of plasticity on the crack driving force and to define a less restrictive plasticity correction for cracks at notch roots when load-controlled boundary conditions are imposed. The explicit flaw finite element results also demonstrate that stress intensity factors associated with load-controlled boundary conditions, such as those inherent in the ASME Boiler and Pressure Vessel Code as well as in most handbooks of stress intensity factors, can be much higher than those associated with displacement-controlled conditions, such as those that produce residual or thermal stresses. Under certain conditions, the inclusion of plasticity effects for cracks loaded by displacement-controlled boundary conditions reduces the crack driving force thus justifying the elimination of a plasticity correction for such loadings. The results of this study form the basis for removing unnecessary conservatism from flaw evaluation procedures that utilize plasticity corrections.

Friedman, E.

1998-11-25T23:59:59.000Z

239

Development of a Conventional Fine Grain Casting Process  

Science Conference Proceedings (OSTI)

However, all the liners cracked or spalled due to low thermal ... Failure analysis indicated that nonmetallic inclusions were the source of .... and neutron radiation

240

Ocean Thermal Energy Conversion  

Energy.gov (U.S. Department of Energy (DOE))

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

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Thermal and Thermomechanical Processing  

Science Conference Proceedings (OSTI)

Oct 8, 2012 ... State of the art Steelmaking with use of residual-free Direct-reduced iron (DRI) and continuous casting with dynamic soft reduction were ...

242

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

E-Print Network (OSTI)

drift-scale thermal test at Yucca Mountain, Nevada. Lawrencemechanical analyses of the Yucca Mountain Drift Scale Test–waste repository at Yucca Mountain, Nevada. The modeling

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

2010-01-01T23:59:59.000Z

243

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

Science Conference Proceedings (OSTI)

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.

Donna Post Guillen; Brian G. Williams

2005-05-01T23:59:59.000Z

244

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

Science Conference Proceedings (OSTI)

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.

Venezuela

2000-04-06T23:59:59.000Z

245

Cracking in liquid petroleum gas Horton spheres  

Science Conference Proceedings (OSTI)

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.

Trivedi, D.K. Gupta, S.C. [Oil and Natural Gas Corp., Surat (India). Hazari Gas Processing Complex

1997-07-01T23:59:59.000Z

246

Insights Gained from Ultrasonic Testing of Piping Welds Subjected to the Mechanical Stress Improvement Process  

SciTech Connect

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 leak-before-break piping systems. Part of this involves determining whether inspections alone, or inspections plus mitigation, are needed. This work addresses the reliability of ultrasonic testing (UT) of cracks that have been mitigated by the mechanical stress improvement process (MSIP). The MSIP has been approved by the NRC (NUREG-0313) since 1986 and modifies residual stresses remaining after welding with compressive, or neutral, stresses near the inner diameter surface of the pipe. This compressive stress is thought to arrest existing cracks and inhibit new crack formation. To evaluate the effectiveness of the MSIP and the reliability of ultrasonic inspections, flaws were evaluated both before and after MSIP application. An initial investigation was based on data acquired from cracked areas in 325-mm-diameter piping at the Ignalina Nuclear Power Plant (INPP) in Lithuania. In a follow-on exercise, PNNL acquired and evaluated similar UT data from a dissimilar metal weld (DMW) specimen containing implanted thermal fatigue cracks. The DMW specimen is a carbon steel nozzle-to-safe end-to-stainless steel pipe section that simulates a pressurizer surge nozzle. The flaws were implanted in the nozzle-to-safe end Alloy 82/182 butter region. Results are presented on the effects of MSIP on specimen surfaces, and on UT flaw responses.

Anderson, Michael T.; Cinson, Anthony D.; Crawford, Susan L.; Diaz, Aaron A.; Moran, Traci L.

2010-12-01T23:59:59.000Z

247

Modeling of solar receiver for cracking of liquid petroleum gas  

SciTech Connect

The paper presents the model of an industrial solar receiver/reactor for thermal cracking of liquid petroleum gas (LPG) at the typical temperature range of 800--850 C. The concentrated solar radiation enters the receiver located on the ground and provided with a compound parabolic concentrator (CPC) at the ceiling. This is achieved with a reflecting solar tower. The radiative model uses the classical concept of equivalent gray plane to represent a panel of 40 cracking tubes placed in parallel of a refractory wall of the receiver. The radiative flux distribution on each wall is calculated and the chemistry in each reactor tube is evaluated until convergence is achieved. The design of an industrial size receiver, its behavior, and performance have been evaluated using this model. The computer program based on this model was run for a variety of flow conditions, feed compositions, and pressures.

Segal, A.; Epstein, M. [Weizmann Inst. of Science, Rehovot (Israel). Solar Research Facilities Unit

1997-02-01T23:59:59.000Z

248

Coolant Sub-Channel and Smeared-Cracking Models in BISON | Department of  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Coolant Sub-Channel and Smeared-Cracking Models in BISON Coolant Sub-Channel and Smeared-Cracking Models in BISON Coolant Sub-Channel and Smeared-Cracking Models in BISON January 29, 2013 - 10:45am Addthis Coolant Sub-Channel and Smeared-Cracking Models in BISON A single-pin coolant sub-channel model was implemented in BISON, the pin-scale simulation code. This enables BISON to compute the heat transfer coefficient and coolant temperature as a function of axial position along the fuel pin (rather than requiring this information to be supplied by the user). At present, the model is only applicable to pressurized water reactor coolant conditions, but modifications to include boiling water reactor (BWR) coolant conditions are in progress. A preliminary UO2 thermal and irradiation creep model has been implemented in BISON and is

249

CRACK GROWTH RESPONSE OF ALLOY 690 IN SIMULATED PWR PRIMARY WATER  

SciTech Connect

The stress corrosion crack growth response of three extruded alloy 690 CRDM tube heats was investigated in several thermomechanical conditions. Extremely low propagation rates (< 1 x 10{sup -9} mm/s) were observed under constant stress intensity factor (K) loading at 325-350 C in the as-received, thermally treated (TT) materials despite using a variety of transitioning techniques. Post-test observation of the crack-growth surfaces revealed only isolated intergranular (IG) cracking. One-dimensional cold rolling to 17% reduction and testing in the S-L orientation did not promote enhanced stress corrosion rates. However, somewhat higher propagation rates were observed in a 30% cold-rolled alloy 690TT specimen tested in the T-L orientation. Cracking of the cold-rolled material was promoted on grain boundaries oriented parallel to the rolling plane with the % IG increasing with the amount of cold rolling.

Toloczko, Mychailo B.; Bruemmer, Stephen M.

2009-12-01T23:59:59.000Z

250

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

DOE Green Energy (OSTI)

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.

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

2009-08-01T23:59:59.000Z

251

Numerical Simulation of Thermal-Solid Coupling to Coal-Rock during the Process of Heat Injection Mine for CBM  

Science Conference Proceedings (OSTI)

For gaining effective influence radius of heat injection mine for CBM (Coal Bed Methane) and influence rules of permeability under the condition of temperature and effective stress, heat transfer and elastic mechanics theory combined, hooker law of thermal ... Keywords: heat injection, thermal-solid coupling, numerical simulation, effective influence radius, permeability

Xin Le Yang; Yong Li Zhang

2010-12-01T23:59:59.000Z

252

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

SciTech Connect

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.

Yue Kuo

2010-08-15T23:59:59.000Z

253

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

E-Print Network (OSTI)

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

Zuo, Yanjia

2010-01-01T23:59:59.000Z

254

Micromechanisms of monotonic and cyclic subcritical crack growth in advanced high-melting-point low-ductility intermetallics. Annual report No. 1, 15 Apr 90-14 Apr 91  

Science Conference Proceedings (OSTI)

The next generation of high-performance jet engines will require markedly stiffer materials, operating at higher stress levels and capable of withstanding temperatures of up to 1650 C. Prime candidates for such applications include ordered intermetallics, ceramics and composites based on metal, intermetallic and ceramic or carbon matrices, all of which are currently of limited use due to their low ductility and fracture properties. Moreover, there is a lack of fundamental understanding on the micromechanisms influencing crack growth in these materials, particularly intermetallics. Accordingly, the present study is aimed at exploring the potential of intermetallic alloys and their composites as advanced structural materials by identifying the critical factors influencing the crack-propagation resistance under monotonic and cyclic loads. Attention is focused on the Nb{sub 3}Al and TiAl intermetallic systems. In both cases, the principal mechanism of toughening is to impede crack advance from crack bridging by ductile second phase particles. Reactive sintering and vacuum hot pressing techniques are successful is processing Nb{sub 3}Al intermetallics and duplex Nb/Nb{sub 3}Al microstructure with a stringy niobium phase can be achieved through thermal treatments. Characterization of mechanical properties will commence in the second year.

Rao, K.T.; Murugesh, L.; DeJonghe, L.C.

1991-05-01T23:59:59.000Z

255

The influence of cracks in rotating shafts  

E-Print Network (OSTI)

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

Jean-Jacques Sinou; A. W. Lees

2008-01-19T23:59:59.000Z

256

The effect of aqueous environments upon the initiation and propagation of fatigue cracks in low-alloy steels  

Science Conference Proceedings (OSTI)

The effect of elevated temperature aqueous environments upon the initiation and propagation of fatigue cracks in low-alloy steels is discussed in terms of the several parameters which influence such behavior. These parameters include water chemistry, impurities within the steels themselves, as well as factors such as the water flow rate, loading waveform and loading rates. Some of these parameters have similar effects upon both crack initiation and propagation, while others exhibit different effects in the two stages of cracking. In the case of environmentally-assisted crack (EAC) growth, the most important impurities within the steel are metallurgical sulfide inclusions which dissolve upon contact with the water. A ``critical`` concentration of sulfide ions at the crack tip can then induce environmentally-assisted cracking which proceeds at significantly increased crack growth rates over those observed in air. The occurrence, or non-occurrence, of EAC is governed by the mass-transport of sulfide ions to and from the crack-tip region, and the mass-transport is discussed in terms of diffusion, ion migration, and convection induced within the crack enclave. Examples are given of convective mass-transport within the crack enclave resulting from external free stream flow. The initiation of fatigue cracks in elevated temperature aqueous environments, as measured by the S-N fatigue lifetimes, is also strongly influenced by the parameters identified above. The influence of sulfide inclusions does not appear to be as strong on the crack initiation process as it is on crack propagation. The oxygen content of the environment appears to be the dominant factor, although loading frequency (strain rate) and temperature are also important factors.

James, L.A. [Westinghouse Electric Corp., West Mifflin, PA (United States). Bettis Atomic Power Lab.; Van Der Sluys, W.A. [Babcock and Wilcox Co., Alliance, OH (United States)

1996-01-01T23:59:59.000Z

257

Environmentally Assisted Cracking Susceptibility Assessment of AP ...  

Science Conference Proceedings (OSTI)

Presentation Title, Environmentally Assisted Cracking Susceptibility Assessment of AP 1000 Reactor Coolant Pump Flywheel Retainer Ring A289 18Cr-18Mn ...

258

Sulfide Stress Cracking in Steels - A Review  

Science Conference Proceedings (OSTI)

Symposium, Corrosion and Corrosion Protection of Materials in the Oil and Gas Industry. Presentation Title, Sulfide Stress Cracking in Steels - A Review.

259

Stress Corrosion Cracking - Programmaster.org  

Science Conference Proceedings (OSTI)

Oct 28, 2013 ... Atomic Ordering in Alloy 690 and Its Effect on Long-term Structural Stability and Stress Corrosion Cracking Susceptibility: Michael Kaufman1; ...

260

Creep Crack Growth Behaviour of Alloy 718  

Science Conference Proceedings (OSTI)

its creep crack growth is controlled by stress intensity factor regardless of load level .... energy. Since vacancies diffuse from a low strain energy position to a high ...

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Evaluation of Stress-Corrosion Cracking  

Science Conference Proceedings (OSTI)

Table 3   Stress-corrosion cracking of selected material systems...chlorides, seawater Oil/gas production and transmission, oil refining,

262

Crystallographic Orientation Dependence of Fatigue Crack ...  

Science Conference Proceedings (OSTI)

In the present study, fatigue crack propagation behavior of rolled AZ31B magnesium ... Alloy Design for Enhancing the Fracture Resistance of Heat Treated High ...

263

MASSIVELY PARALLEL FULLY COUPLED IMPLICIT MODELING OF COUPLED THERMAL-HYDROLOGICAL-MECHANICAL PROCESSES FOR ENHANCED GEOTHERMAL SYSTEM RESERVOIRS  

SciTech Connect

Development of enhanced geothermal systems (EGS) will require creation of a reservoir of sufficient volume to enable commercial-scale heat transfer from the reservoir rocks to the working fluid. A key assumption associated with reservoir creation/stimulation is that sufficient rock volumes can be hydraulically fractured via both tensile and shear failure, and more importantly by reactivation of naturally existing fractures (by shearing) to create the reservoir. The advancement of EGS greatly depends on our understanding of the dynamics of the intimately coupled rock-fracture-fluid system and our ability to reliably predict how reservoirs behave under stimulation and production. In order to increase our understanding of how reservoirs behave under these conditions, we have developed a physics-based rock deformation and fracture propagation simulator by coupling a discrete element model (DEM) for fracturing with a continuum multiphase flow and heat transport model. In DEM simulations, solid rock is represented by a network of discrete elements (often referred as particles) connected by various types of mechanical bonds such as springs, elastic beams or bonds that have more complex properties (such as stress-dependent elastic constants). Fracturing is represented explicitly as broken bonds (microcracks), which form and coalesce into macroscopic fractures when external load is applied. DEM models have been applied to a very wide range of fracturing processes from the molecular scale (where thermal fluctuations play an important role) to scales on the order of 1 km or greater. In this approach, the continuum flow and heat transport equations are solved on an underlying fixed finite element grid with evolving porosity and permeability for each grid cell that depends on the local structure of the discrete element network (such as DEM particle density). The fluid pressure gradient exerts forces on individual elements of the DEM network, which therefore deforms and fractures. Such deformation/fracturing in turn changes the permeability, which again changes the evolution of fluid pressure, coupling the two phenomena. The intimate coupling between fracturing and fluid flow makes the meso-scale DEM simulations necessary, as these methods have substantial advantages over conventional continuum mechanical models of elastic rock deformation. The challenges that must be overcome to simulate EGS reservoir stimulation, preliminary results, progress to date and near future research directions and opportunities will be discussed.

Robert Podgorney; Hai Huang; Derek Gaston

2010-02-01T23:59:59.000Z

264

Status Review of Initiation of Environmentally Assisted Cracking and Short Crack Growth  

Science Conference Proceedings (OSTI)

This report reviews current knowledge of environmentally assisted cracking EAC initiation and short crack growth by stress corrosion cracking, strain-induced corrosion cracking, and, to a lesser extent, corrosion fatigue in nickel base alloys, austenitic stainless steels, and carbon and low-alloy steels exposed to typical pressurized water reactor PWR and boiling water reactor BWR aqueous environments. The document identifies key gaps in knowledge and recommends areas where additional experimental work i...

2005-12-06T23:59:59.000Z

265

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

E-Print Network (OSTI)

Discontinuous surface cracks during stress corrosion cracking of stainless steel single crystal L Keywords: A. Stainless steel B. SEM C. Stress corrosion a b s t r a c t Single crystal 321 stainless steel, and the river-markings exhibited microshear facets along the {1 1 1} plane. Interaction between the main crack

Volinsky, Alex A.

266

Development of a Low Thermal Expansion, Crack Growth Resistant ...  

Science Conference Proceedings (OSTI)

significant commercial usage in industries as diverse as gas turbine engine static ... Manufacturing and fabricating simplicity, and compatibility of heat treatments ...

267

Method for making dense crack free thin films  

DOE Patents (OSTI)

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.

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

2007-01-16T23:59:59.000Z

268

Evaluation of Fundamental Linkage Among Stress Corrosion Cracking (SCC) Phenomena  

Science Conference Proceedings (OSTI)

Many in-core components of stainless steels in light water reactors (LWRs) are susceptible to a degradation process known as irradiation assisted stress corrosion cracking (IASCC). This report describes the results of environmental testing on irradiated Type 304 stainless steel in boiling water reactor (BWR) and pressurized water reactor (PWR) environments to assess their susceptibility to IASCC. The work was sponsored by the Cooperative IASCC Research (CIR I) Program, an international research effort ma...

2002-10-23T23:59:59.000Z

269

Program on Technology Innovation: A Mechanistic Basis for Irradiation Assisted Stress Corrosion Cracking  

Science Conference Proceedings (OSTI)

Irradiation-assisted stress corrosion cracking (IASCC) refers to intergranular stress corrosion cracking that is accelerated under the action of irradiation in light water reactor core components. It is referred to as “assisted” because irradiation enhances, or accelerates, the IGSCC process over the non-irradiated state. IASCC has been a problem in the nuclear industry for the last 40 years and continues to occur due to a lack of understanding of its underlying mechanism. It is the single most important...

2009-09-08T23:59:59.000Z

270

Crack Formation in the Presence of an Electric Field in Droplets of Laponite Gel  

E-Print Network (OSTI)

When a colloidal gel dries through evaporation, cracks are usually formed, which often reveal underlying processes at work during desiccation. Desiccating colloid droplets of few hundred $\\mu l$ size show interesting effects of pattern formation and cracking which makes this an active subject of current research. Since aqueous gels of clay are known to be strongly affected by an electric field, one may expect crack patterns to exhibit a field effect. In the present study we allow droplets of laponite gel to dry under a radial electric field. This gives rise to highly reproducible patterns of cracks, which depend on the strength, direction and time of exposure to the electric field. For a continuously applied DC voltage, cracks always appear on dissipation of a certain constant amount of energy. If the field is switched off before cracks appear, the observed results are shown to obey a number of empirical scaling relations, which enable us to predict the time of appearance and the number of cracks under specified conditions.

Tajkera Khatun; Tapati Dutta; Sujata Tarafdar

2013-08-14T23:59:59.000Z

271

Computational Weld Mechanics of Hot Crack Nucleation in Nickel ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Computational weld mechanics (CWM) is used to estimate the likelihood of hot crack nucleation in a welded joint. A hot crack nucleates when ...

272

Characterization of Elevated Temperature Fatigue Crack Growth Rates  

Science Conference Proceedings (OSTI)

temperature fatigue and the crack growth rates may be adequately correlated with the ... During creep crack growth the use of rate dependent elastic/plastic frac-.

273

The Effect of Microstructure on the Fatigue Crack Growth Resistance ...  

Science Conference Proceedings (OSTI)

GROWTH RESISTANCE OF NICKEL BASE SUF'RRALLOYS. Randy Bowman ... damage are most resistant to crack growth. ... crack propagation. (FCP) was ...

274

High cycle fatigue and fatigue crack propagation behavior of ...  

Science Conference Proceedings (OSTI)

And fatigue crack propagation rates of modified A7075 showed slightly lower. Those superior fatigue strength and resistance of fatigue crack propagation of ...

275

The Hy-C process (thermal decomposition of natural gas): Potentially the lowest cost source of hydrogen with the least CO{sub 2} emission  

SciTech Connect

The abundance of natural gas as a natural resource and its high hydrogen content make it a prime candidate for a low cost supply of hydrogen. The thermal decomposition of natural gas by methane pyrolysis produces carbon and hydrogen. The process energy required to produce one mol of hydrogen is only 5.3% of the higher heating value of methane. The thermal efficiency for hydrogen production as a fuel without the use of carbon as a fuel, can be as high as 60%. Conventional steam reforming of methane requires 8.9% process energy per mole of hydrogen even though 4 moles of hydrogen can be produced per mole of methane, compared to 2 moles by methane pyrolysis. When considering greenhouse global gas warming, methane pyrolysis produces the least amount of CO{sub 2} emissions per unit of hydrogen and can be totally eliminated when the carbon produced is either sequestered or sold as a materials commodity, and hydrogen is used to fuel the process. Conventional steam reforming of natural gas and CO shifting produces large amounts of CO{sub 2} emissions. The energy requirement for non-fossil, solar, nuclear, and hydropower production of hydrogen, mainly through electrolysis, is much greater than that from natural gas. From the resource available energy and environmental points of view, production of hydrogen by methane pyrolysis is most attractive. The by-product carbon black, when credited as a saleable material, makes hydrogen by thermal decomposition of natural gas (the Hy-C process) potentially the lowest cost source of large amounts of hydrogen.

Steinberg, M.

1994-12-01T23:59:59.000Z

276

Stress corrosion cracking of type 304L stainless steel core shroud welds.  

SciTech Connect

Microstructural analyses by advanced metallographic techniques were conducted on mockup welds and a cracked BWR core shroud weld fabricated from Type 304L stainless steel. heat-affected zones of the shroud weld and mockup shielded-metal-arc welds were free of grain-boundary carbide, martensite, delta ferrite, or Cr depletion near grain boundaries. However, as a result of exposure to welding fumes, the heat-affected zones of the welds were significantly contaminated by fluorine and oxygen which migrate to grain boundaries. Significant oxygen contamination promotes fluorine contamination and suppresses classical thermal sensitization, even in Type 304 steels. Results of slow-strain-rate tensile tests indicate that fluorine exacerbates the susceptibility of irradiated steels to intergranular stress corrosion cracking. These observations, combined with previous reports on the strong influence of weld flux, indicate that oxygen and fluorine contamination and fluorine-catalyzed stress corrosion play a major role in cracking of Type 304L stainless steel core shroud welds.

Chung, H. M.; Park, J.-H.; Sanecki, J. E.; Zaluzec, N. J.; Yu, M. S.; Yang, T. T.

1999-10-26T23:59:59.000Z

277

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

SciTech Connect

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

Edward Levy

2012-06-29T23:59:59.000Z

278

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

E-Print Network (OSTI)

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

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

2012-09-16T23:59:59.000Z

279

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

E-Print Network (OSTI)

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

Tsoy, L A; Komarov, A G; Tsoy, A N

2012-01-01T23:59:59.000Z

280

Numerical modeling of crack reorientation and link-up  

Science Conference Proceedings (OSTI)

The FRANC3D/BES software system has been used to simulate the reorientation and link-up of hydraulic fractures in three-dimensional (3D) problems. The adopted technique only needs to discretize the body surface and the crack surface. The crack propagation ... Keywords: FRANC3D/BES, crack propagation, multiple cracks

C. Y. Dong; C. J. de Pater

2002-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

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

E-Print Network (OSTI)

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

Shim, JongMin, 1975-

2005-01-01T23:59:59.000Z

282

The Effects of Test Temperature, Temper, and Alloyed Copper on the Hydrogen-Controlled Crack Growth Rate of an Al-Zn-Mg-(Cu) Alloy  

DOE Green Energy (OSTI)

The hydrogen embrittlement controlled stage II crack growth rate of AA 7050 (6.09 wt.% Zn, 2.14 wt% Mg, 2.19 wt.% Cu) was investigated as a function of temper and alloyed copper level in a humid air environment at various temperatures. Three tempers representing the underaged, peak aged, and overaged conditions were tested in 90% relative humidity (RH) air at temperatures between 25 and 90 C. At all test temperatures, an increased degree of aging (from underaged to overaged) produced slower stage II crack growth rates. The stage II crack growth rate of each alloy and temper displayed Arrhenius-type temperature dependence with activation energies between 58 and 99 kJ/mol. For both the normal copper and low copper alloys, the fracture path was predominantly intergranular at all test temperatures (25-90 C) in each temper investigated. Comparison of the stage II crack growth rates for normal (2.19 wt.%) and low (0.06 wt.%) copper alloys in the peak aged and overaged tempers showed the beneficial effect of copper additions on stage II crack growth rate in humid air. In the 2.19 wt.% copper alloy, the significant decrease ({approx} 10 times at 25 C) in stage II crack growth rate upon overaging is attributed to an increase in the apparent activation energy for crack growth. IN the 0.06 wt.% copper alloy, overaging did not increase the activation energy for crack growth but did lower the pre-exponential factor, {nu}{sub 0}, resulting in a modest ({approx} 2.5 times at 25 C) decrease in crack growth rate. These results indicate that alloyed copper and thermal aging affect the kinetic factors that govern stage II crack growth rate. Overaged, copper bearing alloys are not intrinsically immune to hydrogen environment assisted cracking but are more resistant due to an increased apparent activation energy for stage II crack growth.

G.A. Young, Jr.; J.R. Scully

2000-09-17T23:59:59.000Z

283

REIMR - A Process for Utilizing Liquid Rocket Propulsion-Oriented 'Lessons Learned' to Mitigate Development Risk in Nuclear Thermal Propulsion  

SciTech Connect

This paper is a summary overview of a study conducted at the NASA Marshall Space Flight Center (NASA-MSFC) during the initial phases of the Space Launch Initiative (SLI) program to evaluate a large number of technical problems associated with the design, development, test, evaluation and operation of several major liquid propellant rocket engine systems (i.e., SSME, Fastrac, J-2, F-1). One of the primary results of this study was the identification of the 'Fundamental Root Causes' that enabled the technical problems to manifest, and practices that can be implemented to prevent them from recurring in future propulsion system development efforts, such as that which is currently envisioned in the field of nuclear thermal propulsion (NTP). This paper will discus the Fundamental Root Causes, cite some examples of how the technical problems arose from them, and provide a discussion of how they can be mitigated or avoided in the development of an NTP system.

Ballard, Richard O. [Nuclear and Advanced Propulsion Systems Engineering Branch, NASA Marshall Space Flight Center, AL 35812 (United States)

2006-01-20T23:59:59.000Z

284

SAES ST 909 PILOT SCALE METHANE CRACKING TESTS  

DOE Green Energy (OSTI)

Pilot scale (500 gram) SAES St 909 methane cracking tests were conducted to determine material performance for tritium process applications. Tests that ran up to 1400 hours have been performed at 700 C, 202.7 kPa (1520 torr) with a 30 sccm feed of methane, with various impurities, in a 20 vol% hydrogen, balance helium, stream. A 2.5 vol% methane feed was reduced below 30 ppm for 631 hours. A feed of 1.1 vol% methane plus 1.4 vol% carbon dioxide was reduced below 30 ppm for 513 hours. The amount of carbon dioxide gettered by St 909 can be equated to an equivalent amount of methane gettered to estimate a reduced bed life for methane cracking. The effect of 0.4 vol % and 2.1 vol% nitrogen in the feed reduced the time to exceed 30 ppm methane to 362 and 45 hours, respectively, but the nitrogen equivalence to reduced methane gettering capacity was found to be dependent on the nitrogen feed composition. Decreased hydrogen concentrations increased methane getter rates while a drop of 30 C in one bed zone increased methane emissions by over a factor of 30. The impact of gettered nitrogen can be somewhat minimized if the nitrogen feed to the bed has been stopped and sufficient time given to recover the methane cracking rate.

Klein, J; Henry Sessions, H

2007-07-02T23:59:59.000Z

285

A thermal active restrained shrinkage ring test to study the early age concrete behaviour of massive structures  

Science Conference Proceedings (OSTI)

In massive concrete structures, cracking may occur during hardening, especially if autogenous and thermal strains are restrained. The concrete permeability due to this cracking may rise significantly and thus increase leakage (in tank, nuclear containment...) and reduce the durability. The restrained shrinkage ring test is used to study the early age concrete behaviour (delayed strains evolution and cracking). This test shows, at 20 {sup o}C and without drying, for a concrete mix which is representative of a French nuclear power plant containment vessel (w/c ratio equal to 0.57), that the amplitude of autogenous shrinkage (about 40 {mu}m/m for the studied concrete mix) is not high enough to cause cracking. Indeed, in this configuration, thermal shrinkage is not significant, whereas this is a major concern for massive structures. Therefore, an active test has been developed to study cracking due to restrained thermal shrinkage. This test is an evolution of the classical restrained shrinkage ring test. It allows to take into account both autogenous and thermal shrinkages. Its principle is to create the thermal strain effects by increasing the temperature of the brass ring (by a fluid circulation) in order to expand it. With this test, the early age cracking due to restrained shrinkage, the influence of reinforcement and construction joints have been experimentally studied. It shows that, as expected, reinforcement leads to an increase of the number of cracks but a decrease of crack widths. Moreover, cracking occurs preferentially at the construction joint.

Briffaut, M. [LMT/ENS Cachan/CNRS UMR8535/UPMC/PRES UniverSud Paris, Cachan (France); Institut de radioprotection et de surete nucleaire, Fontenay-aux-Roses (France); Benboudjema, F. [LMT/ENS Cachan/CNRS UMR8535/UPMC/PRES UniverSud Paris, Cachan (France); Torrenti, J.M., E-mail: jean-michel.torrenti@lcpc.f [Universite Paris Est, Laboratoire central des ponts et chaussees, Paris (France); Nahas, G. [LMT/ENS Cachan/CNRS UMR8535/UPMC/PRES UniverSud Paris, Cachan (France); Institut de radioprotection et de surete nucleaire, Fontenay-aux-Roses (France)

2011-01-15T23:59:59.000Z

286

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

SciTech Connect

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

Paton, Chad; Schiller, Martin; Bizzarro, Martin, E-mail: chadpaton@gmail.com, E-mail: schiller@snm.ku.dk, E-mail: bizzarro@snm.ku.dk [Centre for Star and Planet Formation, Natural History Museum of Denmark, University of Copenhagen, Copenhagen DK-1350 (Denmark)

2013-02-01T23:59:59.000Z

287

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

Science Conference Proceedings (OSTI)

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.

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

1996-02-01T23:59:59.000Z

288

A literature review of coupled thermal-hydrologic-mechanical-chemical processes pertinent to the proposed high-level nuclear waste repository at Yucca Mountain  

SciTech Connect

A literature review has been conducted to determine the state of knowledge available in the modeling of coupled thermal (T), hydrologic (H), mechanical (M), and chemical (C) processes relevant to the design and/or performance of the proposed high-level waste (HLW) repository at Yucca Mountain, Nevada. The review focuses on identifying coupling mechanisms between individual processes and assessing their importance (i.e., if the coupling is either important, potentially important, or negligible). The significance of considering THMC-coupled processes lies in whether or not the processes impact the design and/or performance objectives of the repository. A review, such as reported here, is useful in identifying which coupled effects will be important, hence which coupled effects will need to be investigated by the US Nuclear Regulatory Commission in order to assess the assumptions, data, analyses, and conclusions in the design and performance assessment of a geologic reposit``. Although this work stems from regulatory interest in the design of the geologic repository, it should be emphasized that the repository design implicitly considers all of the repository performance objectives, including those associated with the time after permanent closure. The scope of this review is considered beyond previous assessments in that it attempts with the current state-of-knowledge) to determine which couplings are important, and identify which computer codes are currently available to model coupled processes.

Manteufel, R.D.; Ahola, M.P.; Turner, D.R.; Chowdhury, A.H. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

1993-07-01T23:59:59.000Z

289

Analysis of the economic potential of solar thermal energy to provide industrial process heat. Final report, Volume I. [In-depth analysis of 78 industries  

SciTech Connect

The process heat data base assembled as the result of this survey includes specific process applications from 78 four-digit Standard Industrial Classification (SIC) groups. These applications account for the consumption of 9.81 quadrillion Btu in 1974, about 59 percent of the 16.6 quadrillion Btu estimated to have been used for all process heat in 1974. About 7/sup 1///sub 2/ percent of industrial process heat is used below 212/sup 0/F (100/sup 0/C), and 28 percent below 550/sup 0/F (288/sup 0/C). In this study, the quantitative assessment of the potential of solar thermal energy systems to provide industrial process heat indicates that solar energy has a maximum potential to provide 0.6 quadrillion Btu per year in 1985, and 7.3 quadrillion Btu per year in 2000, in economic competition with the projected costs of conventional fossil fuels for applications having a maximum required temperature of 550/sup 0/ (288/sup 0/C). A wide variety of collector types were compared for performance and cost characteristics. Performance calculations were carried out for a baseline solar system providing hot water in representative cities in six geographical regions within the U.S. Specific industries that should have significant potential for solar process heat for a variety of reasons include food, textiles, chemicals, and primary metals. Lumber and wood products, and paper and allied products also appear to have significant potential. However, good potential applications for solar process heat can be found across the board throughout industry. Finally, an assessment of nontechnical issues that may influence the use of solar process heat in industry showed that the most important issues are the establishment of solar rights, standardization and certification for solar components and systems, and resolution of certain labor-related issues. (Volume 1 of 3 volumes.)

1977-02-07T23:59:59.000Z

290

Thermal spray coatings on Yankee dryers  

SciTech Connect

Several failure investigations and recent research on thermal spray coatings on Yankee dryer surfaces show at least three modes of environmentally induced degradation. Corrosion may occur with the ingress of certain chemicals into coating pores. Erosion or corrosion is manifested by streaks at local sites of high doctor blade loading. Erosion and cracking occur due to coating parameters, thermal stress, and differential expansion. While most of the results described in this paper are from investigations of molybdenum, stainless steel coatings also are discussed.

Bowers, D.F. (Packer Engineering, Inc., Naperville, IL (United States))

1994-08-01T23:59:59.000Z

291

Procession  

E-Print Network (OSTI)

UEE 2008 Ziermann, Martin 2004 Macht und Architektur: ZweiP ROCESSION Martin Stadler EDITORS W ILLEKE W ENDRICHFull Citation: Stadler, Martin, 2008, Procession. In Jacco

Stadler, Martin

2008-01-01T23:59:59.000Z

292

Processing  

Science Conference Proceedings (OSTI)

...are processed to complex final shapes by investment casting. Iron-nickel-base superalloys are not customarily investment cast. Investment casting permits intricate internal cooling

293

Development of CFD-Based Simulation Tools for In-Situ Thermal Processing of Oil Shale/Sands  

Science Conference Proceedings (OSTI)

In our research, we are taking the novel approach of developing and applying high performance computing, computational fluid dynamics (CFD)-based simulation tools to a modified in-situ process for production of oil from oil shale. The simulation tools being developed capture the relevant physical processes and data from a large-scale system. The modified in-situ application is a pilot-scale heat transfer process inside Red Leaf Resourcesâ?? EcoShale capsule. We demonstrate the need to understand fluid flow behavior in the convective channels of the rubblized shale bed as convective heating greatly decreases the time required to heat the oil shale to the production temperature when compared with conductive heating alone. We have developed and implemented a geometry creation strategy for a representative section of the EcoShale capsule, developed a meshing approach to deal with the complicated geometry and produce a well-behaved mesh, analyzed the effects of boundary conditions on the simulation results, and devised a new operator splitting solution algorithm that reduces computational costs by taking advantage of the differing convective and conductive time scales occurring in the simulation. These simulation tools can be applied to a wide range of processes involving convective fluid flow heating in rubblized beds.

None

2012-04-30T23:59:59.000Z

294

Effect of Hot Cracks on EAC Crack Initiation and Growth in Nickel ...  

Science Conference Proceedings (OSTI)

No crack initiation/extension from hot cracks occured in any weld metals, which is ... Applicability of Lean Grade of Duplex Stainless Steels in Nuclear Power Plants .... Wear of Zircaloy-4 Grid Straps Due to Fretting and Periodic Impact with RV ...

295

TRANSPORT THROUGH CRACKED CONCRETE: LITERATURE REVIEW  

SciTech Connect

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.

Langton, C.

2012-05-11T23:59:59.000Z

296

Linking Grain Boundary Microstructure to Stress Corrosion Cracking of Cold Rolled Alloy 690 in PWR Primary Water  

SciTech Connect

Grain boundary microstructures and microchemistries are examined in cold-rolled alloy 690 tubing and plate materials and comparisons are made to intergranular stress corrosion cracking (IGSCC) behavior in PWR primary water. Chromium carbide precipitation is found to be a key aspect for materials in both the mill annealed and thermally treated conditions. Cold rolling to high levels of reduction was discovered to produce small IG voids and cracked carbides in alloys with a high density of grain boundary carbides. The degree of permanent grain boundary damage from cold rolling was found to depend directly on the initial IG carbide distribution. For the same degree of cold rolling, alloys with few IG precipitates exhibited much less permanent damage. Although this difference in grain boundary damage appears to correlate with measured SCC growth rates, crack tip examinations reveal that cracked carbides appeared to blunt propagation of IGSCC cracks in many cases. Preliminary results suggest that the localized grain boundary strains and stresses produced during cold rolling promote IGSCC susceptibility and not the cracked carbides and voids.

Bruemmer, Stephen M.; Olszta, Matthew J.; Toloczko, Mychailo B.; Thomas, Larry E.

2012-10-01T23:59:59.000Z

297

A review of test results on parabolic dish solar thermal power modules with dish-mounted rankine engines and for production of process steam  

SciTech Connect

This paper presents results of development testing of various solar thermal parabolic dish modules and assemblies. Most of the tests were at modules and assemblies that used a dish-mounted, organic Rankine cycle turbine for production of electric power. Some tests were also run on equipment for production of process steam or for production of electricity using dish-mounted reciprocating steam engines. These tests indicate that early modules achieve efficiencies of about 18 percent in converting sunlight to electricity (excluding the inverter but including parasitics). A number of malfunctions occurred. The performance measurements, as well as the malfunctions and other operating experience, provided information that should be of value in developing systems with improved performance and reduced maintenance.

Jaffe, L.D.

1988-11-01T23:59:59.000Z

298

Adsorbent-treated cat cracked gasoline in motor fuels  

SciTech Connect

A methof is described for supressing carburetor deposit formation of motor fuels containing untreated cat cracked gasoline by blending adsorbent-treated cat cracked gasoline into the motor fuel. Up to about 50 percent by weight of the total composition is adsorbent treated cat cracked gasoline, but preferably from about 5 to about 25 percent by weight of the total composition is adsorbent treated cat cracked gasoline. In a preferred embodiment a standard reference fuel capable of providing a predetermined level of carburetor deposit formation is provided by the addition of either adsorbent-treated cat cracked gasoline, untreated cat cracked gasoline, or aromatic amines to a base fuel.

Thomas, S.P.

1980-09-30T23:59:59.000Z

299

Thermally Processed High-Mobility MOS Thin-Film Transistors on Transferable Single-Crystal Elastically Strain-Sharing Si/SiGe/Si Nanomembranes  

DOE Green Energy (OSTI)

Demonstration of high-performance MOS thin-film transistors (TFTs) on elastically strain-sharing single-crystal Si/SiGe/Si nanomembranes (SiNMs) that are transferred to foreign substrates is reported. The transferable SiNMs are realized by first growing pseudomorphic SiGe and Si layers on silicon-on-insulator (SOI) substrates, and then, selectively removing the buried oxide (BOX) layer from the SOI. Before the release, only the SiGe layer is compressively strained. Upon release, part of the compressive strain in the SiGe layer is transferred to the thin Si layers, and the Si layers, thus, become tensile strained. Both the initial compressive strain state in the SiGe layer and the final strain sharing state between the SiGe and the Si layers are verified with X-ray diffraction measurements. The TFTs are fabricated employing the conventional high-temperature MOS process on the strain-shared SiNMs that are transferred to an oxidized Si substrate. The transferred strained-sharing SiNMs show outstanding thermal stability and can withstand the high-temperature TFT process on the new host substrate. The strained-channel TFTs fabricated on the new host substrate show high current drive capability and an average electron effective mobility of 270 cm{sup 2}/V ldr s. The results suggest that transferable and thermally stable single-crystal elastically strain- sharing SiNMs can serve as excellent active material for high-speed device application with a simple and scalable transfer method. The demonstration of MOS TFTs on the transferable nanomembranes may create the opportunity for future high-speed Si CMOS heterogeneous integration on any substrate.

Yuan, H.-C.; Kelly, M. M.; Savage, D. E.; Lagally, M. G.; Celler, G. K.; Zhenqiang, M.

2008-03-01T23:59:59.000Z

300

Energy Basics: Ocean Thermal Energy Conversion  

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

Thermal Energy Conversion A process called ocean thermal energy conversion (OTEC) uses the heat energy stored in the Earth's oceans to generate electricity. OTEC works best when...

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Crack detection using resonant ultrasound spectroscopy  

DOE Patents (OSTI)

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

Migliori, A.; Bell, T.M.

1992-12-31T23:59:59.000Z

302

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

E-Print Network (OSTI)

Processing variables of 100% sorghum noodles were evaluated. A dough was made, extruded to create noodles then dried. Structural, physical, and cooking characteristics of the experimental sorghum noodles, as well as thin spaghetti, commercial Asian rice, broad bean, tapioca, sweet potato and egg noodles were evaluated. In comparison to the commercial noodles, the experimental sorghum noodles had high dry matter loss, but similar water uptake and moisture. The dry matter loss of sorghum noodles was greatly affected by the heating stage before extrusion, with a lower dry matter loss resulting from a longer heating time. The internal structure of the noodles was evaluated with the ESEM. Starch noodles had a thick starchy continuous phase that was smooth and amorphous. The protein based noodles were held together by a gluten matrix, small endosperm pieces with intact starch granules were visible and suspended within the matrix. Noodles made from any grain or starch other than wheat must rely on starch gelatinization for their structure. The sorghum noodles produced in this experiment indicated that sorghum could be used to produce a non-wheat noodle. A sorghum noodle could be a new food product for those who are gluten-intolerant or an alternative food product for the semi-arid tropic regions where sorghum is a native grain.

Leach, Michelle R

1999-01-01T23:59:59.000Z

303

Development of a carbonaceous selective absorber for solar thermal energy collection and process for its formation: Final report  

Science Conference Proceedings (OSTI)

The main goal of the US Department of Energy supported part of this project is to develop information about controlling the complicated chemical processes involved in the formation of a carbonaceous selective absorber and learn what equipment will allow production of this absorber commercially. The work necessary to accomplish this goal is not yet complete. Formation of the carbonaceous selective absorber in the conveyor oven tried so far has been unsatisfactory, because the proper conditions for applying the carbonaceous coating in each conveyor oven fabricated, either have been difficult to obtain, or have been difficult to maintain over an extended period of time. A new conveyor oven is nearing completion which is expected to allow formation of the carbonaceous selective absorber on absorber tubes in a continuous operation over many days without the necessity of cleaning the conveyor oven or changing the thickness of the electroplated nickel catalyst to compensate for changes in the coating environment in the oven. Work under this project concerned with forming and sealing glass panels to test ideas on evacuated glass solar collector designs and production have been generally quite satisfactory. Delays in completion of the selective absorber work, has caused postponement of the fabrication of a small prototype evacuated glass solar collector panel. Preliminary cost estimates of the selective absorber and solar collector panel indicate that this collector system should be lower in cost than evacuated solar collectors now on the market. 4 figs.

Garrison, J.D.

1989-02-25T23:59:59.000Z

304

Thermal Sprays and Ceramic Coatings Assessments: Laboratory and Field Evaluations of Ceramic and Thermal Sprays Coatings  

Science Conference Proceedings (OSTI)

This report includes assessments of Ceramic and Thermal Spray coatings both by laboratory evaluation and analysis of field samples. The field samples are presented as case studies describing the condition of the material solution applied. Several thermal sprays and ceramic coatings were tested and analyzed for their ability to mitigate fireside corrosion, reduce slagging and it's propensity to have circumferential cracking occur due to cyclic temperature variations. In addition, the case studies provide ...

2010-12-31T23:59:59.000Z

305

THERMAL RECOVERY  

NLE Websites -- All DOE Office Websites (Extended Search)

THERMAL RECOVERY Thermal recovery comprises the techniques of steamflooding, cyclic steam stimulation, and in situ combustion. In steamflooding, high-temperature steam is injected...

306

Accelerated Fatigue Crack Growth Behavior of PWA 1480 Single ...  

Science Conference Proceedings (OSTI)

3 456. 610. 1520 30. AK . AKrss. MPa v'?! Fig. 10 Fatigue crack growth rate as a function of AKrss and AK. Prediction of the Microscopic Crack Behavior: An ...

307

Reading of cracked optical discs using iterative learning control  

Science Conference Proceedings (OSTI)

Optical discs, including Compact Discs (CDs), Digital Versatile Discs (DVDs), and Blu-ray Discs (BDs), can get cracked during storage and usage. Such cracks commonly lead to discontinuities in the data track, potentially preventing reading of the data ...

Maarten Steinbuch; Koos Van Berkel; George Leenknegt; Tom Oomen; Jeroen Van De Wijdeven

2009-06-01T23:59:59.000Z

308

Applications of thermal energy storage to process heat storage and recovery in the paper and pulp industry. Final report, September 1977--May 1978  

DOE Green Energy (OSTI)

Applications of Thermal Energy Storage (TES) in a paper and pulp mill power house were studied as one approach to the transfer of steam production from fossil fuel boilers to waste fuel (hog fuel) boilers. Data from specific mills were analyzed, and various TES concepts evaluated for application in the process steam supply system. Constant pressure and variable pressure steam accumulators were found to be the most attractive storage concepts for this application. Performance analyses based on the operation of a math model of the process steam supply system indicate potential substitution of waste wood fuel for 100,000 bbl oil per year per installation with the accumulator TES system. Based on an industry survey of potential TES application, which requires excess base steaming capability, the results from the individual installation were extrapolated to a near-term (1980's) fossil fuel savings in the paper and pulp industry of 3.2 x 10/sup 6/ bbl oil/year. Conceptual designs of mechanical equipment and control systems indicate installed cost estimates of about $560,000 per installation, indicating an after tax return on investment of over 30%.

Carr, J.H.; Hurley, P.J.; Martin, P.J.

1978-09-01T23:59:59.000Z

309

Applications of thermal energy storage to process heat storage and recovery in the paper and pulp industry. Final report, September 1977--May 1978  

SciTech Connect

Applications of Thermal Energy Storage (TES) in a paper and pulp mill power house were studied as one approach to the transfer of steam production from fossil fuel boilers to waste fuel (hog fuel) boilers. Data from specific mills were analyzed, and various TES concepts evaluated for application in the process steam supply system. Constant pressure and variable pressure steam accumulators were found to be the most attractive storage concepts for this application. Performance analyses based on the operation of a math model of the process steam supply system indicate potential substitution of waste wood fuel for 100,000 bbl oil per year per installation with the accumulator TES system. Based on an industry survey of potential TES application, which requires excess base steaming capability, the results from the individual installation were extrapolated to a near-term (1980's) fossil fuel savings in the paper and pulp industry of 3.2 x 10/sup 6/ bbl oil/year. Conceptual designs of mechanical equipment and control systems indicate installed cost estimates of about $560,000 per installation, indicating an after tax return on investment of over 30%.

Carr, J.H.; Hurley, P.J.; Martin, P.J.

1978-09-01T23:59:59.000Z

310

Ocean Thermal Energy Conversion | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

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

311

Girth Weld Cracking at Ethanol Terminal Facilities - Programmaster ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Failure Analysis and Prevention. Presentation Title, Girth Weld Cracking at ...

312

Stress Corrosion Cracking of Steel In Concentrated Nitrate ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2011. Symposium, Environmentally Assisted Cracking of Materials. Presentation Title, Stress ...

313

Interaction between Local Strains and Stress Corrosion Cracks ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2013. Symposium, Environmentally Assisted Cracking (EAC): Laboratory Research and Field ...

314

Stress Corrosion Cracking Observation in API G-105 Grade Drill ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2011. Symposium, Environmentally Assisted Cracking of Materials. Presentation Title, Stress ...

315

Environmentally Assisted Cracking of Stainless Steels and Nickel ...  

Science Conference Proceedings (OSTI)

Oct 10, 2012 ... Intergranular Stress Corrosion Cracking (IGSCC) Mechanism of Structural Component Materials in Pressurized Water Reactors : Young Suk ...

316

stress corrosion cracking of iron and nickel based alloys  

Science Conference Proceedings (OSTI)

This Table of Contents is from Chemistry and Electrochemistry of Corrosion and Stress Corrosion Cracking published by TMS.

317

Latent Cracking of Tantalum - Titanium Welds Due to Hydrogen ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2012. Symposium, Environmentally Assisted Cracking of Materials. Presentation Title, Latent ...

318

Molecular Dynamics of Fatigue Crack Growth in Nanocrystalline ...  

Science Conference Proceedings (OSTI)

Experimental techniques are prohibitive due to limitations of nano samples and advanced microscopic manipulators. In this study, crack propagation under ...

319

Fuzzy modeling of fluidized catalytic cracking unit  

Science Conference Proceedings (OSTI)

The paper deals with the fuzzy system identification of reactor-regenerator-stripper-fractionator's (RRSF) section of a fluidized catalytic cracking unit (FCCU). The fuzzy system identification based on the data collected from an operating refinery of ... Keywords: Dynamic fuzzy model, FCCU models, Fuzzy clustering, Fuzzy inference systems, Fuzzy models, Hybrid learning, Mountain clustering, Supervised learning, Unsupervised learning

Mohammad Fazle Azeem; Nesar Ahmad; M. Hanmandlu

2007-01-01T23:59:59.000Z

320

Cracked rotor vibrations by multifractal analysis  

E-Print Network (OSTI)

Multifractal analysis has been used to diagnoze cracked and healthy rotors. Is has been shown that the complexity and regularity criteria of the dynamical systems defined by the multiple scaling of the time series can indicate the damages of the rotating shaft.

Grzegorz Litak; Jerzy T. Sawicki

2008-04-15T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Honeywords: making password-cracking detectable  

Science Conference Proceedings (OSTI)

We propose a simple method for improving the security of hashed passwords: the maintenance of additional ``honeywords'' (false passwords) associated with each user's account. An adversary who steals a file of hashed passwords and inverts the hash function ... Keywords: authentication, chaffing, honeywords, login, password cracking, password hashes, passwords

Ari Juels, Ronald L. Rivest

2013-11-01T23:59:59.000Z

322

Digital radiographic systems detect boiler tube cracks  

SciTech Connect

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

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

2008-06-15T23:59:59.000Z

323

A Parametric Study of the Lead-Induced Stress Corrosion Cracking of Alloy 690  

Science Conference Proceedings (OSTI)

Alloy 690 steam generator tubing, which has been the material of choice for replacement steam generators, is susceptible to lead-induced stress corrosion cracking (PbSCC) in alkaline environments. No obvious correlation was found between processing parameters or material characteristics and PbSCC susceptibility.

1999-04-22T23:59:59.000Z

324

Technical note: Filling trim cracks on GPU-rendered solid models  

Science Conference Proceedings (OSTI)

We present an algorithm for improving the rendering appearance of CAD models with trimmed freeform surfaces when evaluated on graphics processing units (GPUs). Rendering on client GPUs allows mechanical CAD to embrace cloud computing by storing a single ... Keywords: Cracks, GPU rendering, Geometric modeling, Trimmed surfaces

Sushrut Pavanaskar; Sara Mcmains

2013-02-01T23:59:59.000Z

325

The influence of crack-imbalance orientation and orbital evolution for an extended cracked Jeffcott rotor  

E-Print Network (OSTI)

Vibration peaks occurring at rational fractions of the fundamental rotating critical speed, here named Local Resonances, facilitate cracked shaft detection during machine shut-down. A modified Jeffcott-rotor on journal bearings accounting for gravity effects and oscillating around nontrivial equilibrium points is employed. Modal parameter selection allows this linear model to represent first mode characteristics of real machines. Orbit evolution and vibration patterns are analyzed, yielding useful results. Crack detection results indicate that, instead of 1x and 2x components, analysis of the remaining local resonances should have priority; this is due to crack-residual imbalance interaction and to 2x multiple induced origins. Therefore, local resonances and orbital evolution around 1/2, 1/3 and 1/4 of the critical speed are emphasized for various crack-imbalance orientations.

Julio Gomez-Mancilla; Jean-Jacques Sinou; V. R. Nosov; Fabrice Thouverez; A. Zambrano

2008-01-19T23:59:59.000Z

326

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

E-Print Network (OSTI)

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

Gibbs, Jonathan Paul

2011-01-01T23:59:59.000Z

327

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

E-Print Network (OSTI)

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

Gibbs, Jonathan Paul

328

Materials Reliability Program: Input for Pressurized Thermal Shock Rulemaking (MRP-248)  

Science Conference Proceedings (OSTI)

The Pressurized Thermal Shock (PTS) rule addresses the risk of a nuclear power plant reactor vessel failing due to propagation of a crack through the vessel wall. If a plant has an emergency cool-down event that superimposes a large thermal transient stress on a large pressure stress in the presence of a pre-existing flaw, it is possible that a crack could initiate and propagate through the vessel wall. The resistance of a vessel to crack initiation and propagation declines as the vessel ages. As a resul...

2008-12-23T23:59:59.000Z

329

Research Article HZSM-5 Catalyst for Cracking Palm Oil to Gasoline: A Comparative Study with and without Impregnation  

E-Print Network (OSTI)

It is important to develop a renewable source of energy to overcome a limited source fossil energy. Palm oil is a potential alternative and environmental friendly energy resource in Indonesia due to high production capacity of this vegetable oil. The research studied effect of catalyst to selectivity of biofuel product from cracking of palm oil. The catalyst consisted of HZSM-5 catalyst with or without impregnation. The research was conducted in two steps, namely catalyst synthesized and catalytic cracking process. HZSM-5 was synthesized using Plank methods. The characterization of the synthesized catalysts used AAS (Atomic Absorption Spectroscopy) and BET (Brunaueur Emmet Teller). The cracking was carried out in a fixed bed microreactor with diameter of 1 cm and length of 16 cm which was filled with 0.6 gram catalyst. The Ni/HZSM-5 catalyst was recommended for cracking palm oil for the high selectivity to gasoline. © 2013

Achmad Roesyadi; Danawati Hariprajitno; N. Nurjannah; Santi Dyah Savitri

2012-01-01T23:59:59.000Z

330

EMAT based inspection of natural gas pipelines for SSC cracks  

NLE Websites -- All DOE Office Websites (Extended Search)

EMAT-Based Inspection of Natural Gas EMAT-Based Inspection of Natural Gas Pipelines for Stress Corrosion Cracks FY2004 Report Venugopal K. Varma, Raymond W. Tucker, Jr., and Austin P. Albright Oak Ridge National Laboratory Oak Ridge, Tennessee 37831 1 This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name,

331

Prediction of Failure Due to Thermal Aging, Corrosion and Environmental Fracture in Amorphous and Titanium Alloys  

DOE Green Energy (OSTI)

DARPA is exploring a number of advanced materials for military applications, including amorphous metals and titanium-based alloys. Equipment made from these materials can undergo degradation due to thermal aging, uniform corrosion, pitting, crevice corrosion, denting, stress corrosion cracking, corrosion fatigue, hydrogen induced cracking and microbial influenced corrosion. Amorphous alloys have exceptional resistance to corrosion, due in part to the absence of grain boundaries, but can undergo crystallization and other phase instabilities during heating and welding. Titanium alloys are extremely corrosion resistant due to the formation of a tenacious passive film of titanium oxide, but is prone to hydrogen absorption in crevices, and hydrogen induced cracking after hydrogen absorption. Accurate predictions of equipment reliability, necessary for strategic planning, requires integrated models that account for all relevant modes of attack, and that can make probabilistic predictions. Once developed, model parameters must be determined experimentally, and the validity of models must be established through careful laboratory and field tests. Such validation testing requires state-of-the-art surface analytical techniques, as well as electrochemical and fracture mechanics tests. The interaction between those processes that perturb the local environment on a surface and those that alter metallurgical condition must be integrated in predictive models. The material and environment come together to drive various modes of corrosive attack (Figure 1). Models must be supported through comprehensive materials testing capabilities. Such capabilities are available at LLNL and include: the Long Term Corrosion Test Facility (LTCTF) where large numbers of standard samples can be exposed to realistic test media at several temperature levels; a reverse DC machine that can be used to monitor the propagation of stress corrosion cracking (SCC) in situ; and banks of potentiostats with temperature controlled cells for potentiostatic and potentiodynamic testing (Figure 2).

Farmer, J C

2003-04-15T23:59:59.000Z

332

Applications of thermal energy storage to process heat and waste heat recovery in the primary aluminum industry. Final report, September 1977-September 1978  

DOE Green Energy (OSTI)

The results of a study entitled, Applications of Thermal Energy Storage to Process Heat and Waste Heat Recovery in the Primary Aluminum Industry are presented. In this preliminary study, a system has been identified by which the large amounts of low-grade waste energy in the primary pollution control system gas stream can be utilized for comfort heating in nearby communities. Energy is stored in the form of hot water, contained in conventional, insulated steel tanks, enabling a more efficient utilization of the constant energy source by the cyclical energy demand. Less expensive energy storage means (heated ponds, aquifers), when they become fully characterized, will allow even more cost-competitive systems. Extensive design tradeoff studies have been performed. These tradeoff studies indicate that a heating demand equivalent to 12,000 single-family residences can be supplied by the energy from the Intalco plant. Using a 30-year payback criterion (consistent with utility planning practice), the average cost of energy supplied over the system useful life is predicted at one-third the average cost of fossil fuel. The study clearly shows that the utilization of waste energy from aluminum plants is both technically and economically attractive. The program included a detailed survey of all aluminum plants within the United States, allowing the site specific analyses to be extrapolated to a national basis. Should waste heat recovery systems be implemented by 1985, a national yearly savings of 6.5 million barrels of oil can be realized.

Katter, L.B.; Hoskins, R.L.

1979-04-01T23:59:59.000Z

333

Residual stresses and stress corrosion cracking in pipe fittings  

Science Conference Proceedings (OSTI)

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

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

1994-06-01T23:59:59.000Z

334

Solar Thermal Conversion  

DOE Green Energy (OSTI)

The thermal conversion process of solar energy is based on well-known phenomena of heat transfer (Kreith 1976). In all thermal conversion processes, solar radiation is absorbed at the surface of a receiver, which contains or is in contact with flow passages through which a working fluid passes. As the receiver heats up, heat is transferred to the working fluid which may be air, water, oil, or a molten salt. The upper temperature that can be achieved in solar thermal conversion depends on the insolation, the degree to which the sunlight is concentrated, and the measures taken to reduce heat losses from the working fluid.

Kreith, F.; Meyer, R. T.

1982-11-01T23:59:59.000Z

335

Effects of Process/Microstructure on the Threshold Fatigue Crack ...  

Science Conference Proceedings (OSTI)

6. D.O. Harris. Journal of Bas~c Engineering, 39. 1967, p.49. 7. M.S. G~lbert and S.N. Malih. unpublished research. GE Aircraft Eng~nes, Cincinnati, Ohio. 8.

336

Catalytic Cracking Downstream Processing of Fresh Feed Input  

U.S. Energy Information Administration (EIA)

-No Data Reported; --= Not Applicable; NA = Not Available; W = Withheld to avoid disclosure of individual company data. Notes: Totals may not equal sum ...

337

An experimental and numerical investigation on the influence of external gas recirculation on the HCCI autoignition process in an engine: Thermal, diluting, and chemical effects  

Science Conference Proceedings (OSTI)

In order to contribute to the solution of controlling the autoignition in a homogeneous charge compression ignition (HCCI) engine, parameters linked to external gas recirculation (EGR) seem to be of particular interest. Experiments performed with EGR present some difficulties in interpreting results using only the diluting and thermal aspect of EGR. Lately, the chemical aspect of EGR is taken more into consideration, because this aspect causes a complex interaction with the dilution and thermal aspects of EGR. This paper studies the influence of EGR on the autoignition process and particularly the chemical aspect of EGR. The diluents present in EGR are simulated by N{sub 2} and CO{sub 2}, with dilution factors going from 0 to 46 vol%. For the chemically active species that could be present in EGR, the species CO, NO, and CH{sub 2}O are used. The initial concentration in the inlet mixture of CO and NO is varied between 0 and 170 ppm, while that of CH{sub 2}O alters between 0 and 1400 ppm. For the investigation of the effect of the chemical species on the autoignition, a fixed dilution factor of 23 vol% and a fixed EGR temperature of 70 C are maintained. The inlet temperature is held at 70 C, the equivalence ratios between 0.29 and 0.41, and the compression ratio at 10.2. The fuels used for the autoignition are n-heptane and PRF40. It appeared that CO, in the investigated domain, did not influence the ignition delays, while NO had two different effects. At concentrations up until 45 ppm, NO advanced the ignition delays for the PRF40 and at higher concentrations, the ignition delayed. The influence of NO on the autoignition of n-heptane seemed to be insignificant, probably due to the higher burn rate of n-heptane. CH{sub 2}O seemed to delay the ignition. The results suggested that especially the formation of OH radicals or their consumption by the chemical additives determines how the reactivity of the autoignition changed. (author)

Machrafi, Hatim; Cavadias, Simeon [UPMC Universite Paris 06, LGPPTS, Ecole Nationale Superieure de Chimie de Paris, 11, rue de Pierre et Marie Curie, 75005 Paris (France); UPMC Universite Paris 06, FRT, Institut Jean Le Rond D'Alembert, 2, place de la Gare de Ceinture, 78210 St Cyr l'Ecole (France); Guibert, Philippe [UPMC Universite Paris 06, FRT, Institut Jean Le Rond D'Alembert, 2, place de la Gare de Ceinture, 78210 St Cyr l'Ecole (France)

2008-11-15T23:59:59.000Z

338

Circumferential cracking of steam generator tubes  

SciTech Connect

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

Karwoski, K.J.

1997-04-01T23:59:59.000Z

339

SCREENING TESTS FOR IMPROVED METHANE CRACKING MATERIALS  

DOE Green Energy (OSTI)

Bench scale (1 to 6 gram) methane cracking tests have been performed on a variety of pure elements, some alloys, and SAES{reg_sign} commercial getters St 101, St 198, St 707, St 737, and St 909 to determine methane cracking performance (MCP) of 5% methane in a helium carrier at 700 C, 101.3 kPa (760 torr) with a 10 sccm feed. The MCP was almost absent from some materials tested while others showed varying degrees of MCP. Re, Cr, V, Gd, and Mo powders had good MCP, but limited capacities. Nickel supported on kieselguhr (Ni/k), a Zr-Ni alloy, and the SAES{reg_sign} getters had good MCP in a helium carrier. The MCP of these same materials was suppressed in a hydrogen carrier stream and the MCP of the Zr-based materials was reduced by nitride formation when tested with a nitrogen carrier gas.

Klein, J; Jeffrey Holder, J

2007-07-16T23:59:59.000Z

340

A computational study of ethane cracking in cluster models of zeolite H-ZSM-5.  

DOE Green Energy (OSTI)

Protolytic cracking of ethane by zeolites has been studied using quantum-chemical techniques and a cluster model of the zeolite Broensted acid site. Previous computational studies have utilized small cluster models and have not accounted for the long-range effects of the zeolite lattice. These studies have found reaction barriers for cracking which are significantly higher than experimental values. In this work we used a larger zeolite cluster model containing five tetrahedral (Si, Al) atoms (denoted 5T) and searched for stationary points along one possible reaction path for cracking at the HF/6-31 G(d) level of theory. This path involves a multi-step cracking reaction, in which the proton is first transferred from the acid site to the adsorbed ethane molecule to form an ion-pair equilibrium complex. Subsequently the proton attacks the C-C bond to complete the cracking process. The activation barrier for cracking was calculated, including corrections for (i) vibrational energies at the experimental reaction temperature of 773 K; (ii) electron correlation and an extended basis set at the B3LYP/6-311+G(3df,2p) level; and (iii) the influence of the surrounding zeolite lattice in H-ZSM-5. The barrier we obtain, 53 {+-} 5 kcal/mol, is significantly smaller than previous theoretical results and is in good agreement with typical experimental values for small hydrocarbons. Work is currently in progress to extend this study by carrying out geometry optimization of these complexes using the B3LYP method of density functional theory.

Zygmunt, S. A.

1998-08-21T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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341

Methane cracking over a bituminous coal char  

Science Conference Proceedings (OSTI)

Methane cracking over a bed of Chinese bituminous coal char was studied using a fixed-bed reactor at atmospheric pressure and temperatures between 1073 and 1223 K. Methane conversion over the fresh char increased with increasing temperature to 90% at 1223 K. Hydrogen was the only gas-phase product that was detected during the experimentation. The char was shown to exert a significant catalytic effect on methane cracking by comparing results from experiments with the raw char and demineralised char as well as from blank experiments using quartz. It was further shown that the ash was not the source of the catalytic effect of the char. However, both methane conversion and hydrogen yield decreased with increasing reaction time, irrespective of other experimental conditions, indicating that the char rapidly became deactivated following the exposure to methane. It was speculated that the deposition of carbon from methane cracking was responsible for this deactivation, which is supported by scanning electron microscopy (SEM) image analysis. It was demonstrated that the catalytic activity of the deactivated char can be partially recovered by burning off the carbon deposits with an oxidizing gas mixture containing 0.46% oxygen. 10 refs., 11 figs., 1 tab.

Zhi-qiang Sun; Jin-hu Wu; Mohammad Haghighi; John Bromly; Esther Ng; Hui Ling Wee; Yang Wang; Dong-ke Zhang [Chinese Academy of Sciences, Taiyuan (China). Institute of Coal Chemistry

2007-06-15T23:59:59.000Z

342

Syngas Production from Propane Using Atmospheric Non-thermal Plasma  

E-Print Network (OSTI)

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

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

2009-01-01T23:59:59.000Z

343

Final report on PCRV thermal cylinder axial tendon failures  

SciTech Connect

The post-test examination of the failed tendons from the PCRV thermal cylinder experiment has been concluded. Failures in the wires are attributed to stress-corrosion cracking. The cause of tendon failures has not been unequivocably established, but they may have been due to nitrates in the duct. The wires employed in the manufacture of the tendons will crack in less than 72 hr in a 0.2 M solution of ammonium nitrate at 70$sup 0$C. The quality of the wires is poor, and surface cracks were detected. These could have acted as concentrating sites for both stress and the deleterious contaminants. It is believed that the factors that led to the failures in the thermal cylinder experiment were unique. An improper formulation of the epoxy resin did not provide the tendon anchor plate seal that was desired; indeed, the improper formulation is responsible for the high level of nitrogen in the ducts of the failed tendons. (auth)

Canonico, D.A.; Griess, J.C.; Robinson, G.C.

1976-01-01T23:59:59.000Z

344

Role of crack tip shielding in the initiation and growth of long and small fatigue cracks in composite microstructures  

Science Conference Proceedings (OSTI)

The role of crack tip shielding in retarding the initiation and growth of fatigue cracks has been examined in metallic composite microstructures (consisting of hard and soft phases), with the objective of achieving maximum resistance to fatigue. Specifically, duplex ferritic-martensitic structures have been developed in AISI 1008 and 1015 mild steels to promote shielding without loss in strength. The shielding is developed primarily from crack deflection and resultant crack closure, such that unusually high long crack propagation resistance is obtained. It is found that the fatigue threshold ..delta..K/sub TH/ in AISI 1008 can be increased by more than 100 pct to over 20 MPa ..sqrt..m, without sacrifice in strength, representing the highest ambient temperature threshold reported for a metallic alloy to date. Similar but smaller increases are found in AISI 1015. The effect of the dual-phase microstructures on crack initiation and small crack (10 to 1000 ..mu..m) growth, however, is markedly different, characteristic of behavior influenced by the mutual competition of intrinsic and extrinsic (shielding) ''toughening'' mechanisms. Accordingly, the composite microstructures which appear to show the highest resistance to the growth of long cracks, show the lowest resistance to crack initiation and small crack growth. In general, dual-phase steels are found to display remarkable fatigue properties, with fatigue limits as high as 58 pct of the tensile strengths and fatigue thresholds in the range of 13 to 20 MPa..sqrt..m.

Shang, J.K.; Tzou, J.L.; Ritchie, R.O. (Materials and Chemical Sciences Div., Lawrence Berkeley Lab., and Dept. of Materials Science and Mineral Engineering, Univ. of California, Berkeley, CA (US))

1987-09-01T23:59:59.000Z

345

Thermal fatigue evaluation of solder alloys. Final report  

SciTech Connect

An evaluation was made of the relative thermal fatigue resistance of 29 solder alloys. A number of these alloys were found to be less susceptible to thermal fatigue cracking in encapsulated printed wiring board applications than the commonly used tin-lead eutectic (63Sn-37Pb). Three alloys, 95Sn-5Ag, 96.5Sn-3.5Ag, and 95Sn-5Sb offered the greatest resistance to thermal fatigue. The selection of the encapsulation materials was confirmed to be a significant factor in thermal fatigue of solder joints, regardless of the solder alloy used.

Jarboe, D.M.

1980-02-01T23:59:59.000Z

346

Thermal Flipping of Interstellar Grains  

E-Print Network (OSTI)

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

Joseph C. Weingartner

2008-08-27T23:59:59.000Z

347

Ductile Crack Investigation in Multicomponent Materials  

Science Conference Proceedings (OSTI)

At this stage of the research Authors proposed two scale numerical model. ... Optimization of Thermal Cycle for Rails with Respect to the Wear Resistance.

348

Factors Affecting the Hydrogen Environment Assisted Cracking Resistance of an AL-Zn-Mg-(Cu) Alloy  

DOE Green Energy (OSTI)

Precipitation hardenable Al-Zn-Mg alloys are susceptible to hydrogen environment assisted cracking (HEAC) when exposed to aqueous environments. In Al-Zn-Mg-Cu alloys, overaged tempers are used to increase HEAC resistance at the expense of strength but overaging has little benefit in low copper alloys. However, the mechanism or mechanisms by which overaging imparts HEAC resistance is poorly understood. The present research investigated hydrogen uptake, diffusion, and crack growth rate in 90% relative humidity (RH) air for both a commercial copper bearing Al-Zn-Mg-Cu alloy (AA 7050) and a low copper variant of this alloy in order to better understand the factors which affect HEAC resistance. Experimental methods used to evaluate hydrogen concentrations local to a surface and near a crack tip include nuclear reaction analysis (NRA), focused ion beam, secondary ion mass spectroscopy (FIB/SIMS) and thermal desorption spectroscopy (TDS). Results show that overaging the copper bearing alloys both inhibits hydrogen ingress from oxide covered surfaces and decreases the apparent hydrogen diffusion rates in the metal.

G.A. Young; J.R. Scully

2002-04-09T23:59:59.000Z

349

Relationships Between Stress Corrosion Cracking Tests and Utility ...  

Science Conference Proceedings (OSTI)

Aug 1, 1999 ... Several utility steam generator and stress corrosion cracking ... Superheated steam and neutral solution environments are found to be ...

350

Influence of Different Cooling Structure on Surface Crack of HSLA ...  

Science Conference Proceedings (OSTI)

Presentation Title, Influence of Different Cooling Structure on Surface Crack of .... of Si3N4-SiC Heat Absorption Ceramic Material Used for Tower Type Solar ...

351

Basic Aspects of Superalloy Design for Crack Growth Resistance  

Science Conference Proceedings (OSTI)

theories for fatigue and creep crack growth resistance that are particularly ... devices as the nuclear reactors and in such strategic and expensive vehicles.

352

Stress Corrosion Cracking of Stabilized Austenitic Stainless Steels ...  

Science Conference Proceedings (OSTI)

Aug 1, 1999 ... Stress Corrosion Cracking of Stabilized Austenitic Stainless Steels in Various Types of Nuclear Power Plants by M.O. Speidel and R.

353

Orientation Effects and Influence of Delta Phase on Fatigue Crack ...  

Science Conference Proceedings (OSTI)

including a hold time at maximum load lead to increased crack propagation rates when compared ... 720°C ;' 8 hours .! controlled cooling rate at 50°C per hour.

354

Fatigue Property-Microstructure Relationships and Crack Growth  

Science Conference Proceedings (OSTI)

Feb 28, 2011 ... Effect of Microstructure on Fatigue Behavior of Two Pipeline Steels: .... to a transition crack length (LEFM applicable) is approximated using ...

355

In-vitro Evaluation of Stress Corrosion Cracking of Biomedical ...  

Science Conference Proceedings (OSTI)

In this study, the susceptibility to stress corrosion cracking of biodegradable and aluminium-free magnesium alloys, WZ21 and WE43, was investigated using ...

356

Corrosion Inhibition of Stress Corrosion Cracking and Localized ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Stress corrosion cracking of 7050 aluminum alloys in the turbo expander industry can cause expensive catastrophic failures, especially for turbo

357

Strain Rate Sensitivity of Alloy 718 Stress Corrosion Cracking  

Science Conference Proceedings (OSTI)

Stress corrosion cracking (SCC) tests were conducted in 36O'C pressurized- water-reactor. (PWR) primary water using. Alloy 718 heat-treated to produce.

358

Stress Corrosion Cracking of Aluminium-Free Magnesium Alloys in ...  

Science Conference Proceedings (OSTI)

Presentation Title, Stress Corrosion Cracking of Aluminium-Free Magnesium Alloys in a Simulated Human Body Fluid. Author(s), Lokesh Choudhary, R. K. Singh ...

359

Environmentally Assisted Cracking of Alloy 7050-T7451 Exposed to ...  

Science Conference Proceedings (OSTI)

Under cyclic loading notched specimens failed by transgranular stress corrosion cracking. Striations were observed on the cleavage-like facets. The number of ...

360

Stress Corrosion Crack Initiation of Alloy 690 in Subcritical and ...  

Science Conference Proceedings (OSTI)

Abstract Scope, The objective of this study is to investigate the structure and chemistry of corrosion and stress corrosion crack initiation in Alloy 690. To avoid

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

grain boundary oxidation and stress corrosion cracking in nickel ...  

Science Conference Proceedings (OSTI)

Accelerated stress corrosion cracking tests and exposures were conducted on alloy 600, Ni-9Fe, and Ni-9Fe-5Cr (LCr) in constant extension rate mode in ...

362

Model for the Superimposed Effects of Stress-Corrosion Cracking ...  

Science Conference Proceedings (OSTI)

Symposium, Fatigue and Corrosion Damage in Metallic Materials: Fundamentals, ... and a stress-corrosion cracking mode acting at high stress intensity in NaCl.

363

Stress Corrosion Cracking Threshold of Ti 6-4 Extrusions  

Science Conference Proceedings (OSTI)

Ti 6Al-4V extrusions with standard chemistry and extra low interstitial are evaluated for their stress corrosion cracking resistance. Also examined is the affect of ...

364

A Study on the Stress Corrosion Cracking Mechanism of Carbon ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Carbon steel is susceptible to stress corrosion cracking (SCC) in fuel grade ethanol (FGE). The research results obtained thus far have found ...

365

Stress Corrosion Cracking Initiation of Austenitic Alloys in ...  

Science Conference Proceedings (OSTI)

Presentation Title, Stress Corrosion Cracking Initiation of Austenitic Alloys in Supercritical Water. Author(s), Guoping Cao, Vahid Firouzdor, Todd Allen. On-

366

Galvanic Corrosion and Stress Corrosion Cracking of Steel and ...  

Science Conference Proceedings (OSTI)

No aluminum bolt AW 7075 failed in magnesium due to stress corrosion cracking (SCC). Even aluminum bolts in T6 condition can be used for automotive ...

367

Stress corrosion cracking of zirconium in nitric acid  

Science Conference Proceedings (OSTI)

The susceptibility of zirconium and its common alloys to stress corrosion cracking (SCC) in nitric acid was investigated by slow strain-rate and constant deflection techniques. Cracking occurred at 25/sup 0/C over a wide range of acid concentrations and electrochemical potentials. The crack velocity increased slightly with increasing temperature. The failure mode was transgranular and the morphology was similar to SCC failures of zirconium alloys in other environments. The fracture was very orientation-dependent suggesting that it occurs on a single crystallographic plane in the material. The results of the study are not consistent with a hydrogen mechanism for cracking.

Beavers, J.A.; Griess, J.C.; Boyd, W.K.

1980-01-01T23:59:59.000Z

368

One-Dimensional Cold Rolling Effects on Stress Corrosion Crack ...  

Science Conference Proceedings (OSTI)

A Microstructural Investigation on the Effect of Cold Work on Environmentally .... Stress Corrosion Cracking Behavior near the Fusion Boundary of Dissimilar ...

369

Intergranular Liquid Formation, Distribution, and Cracking in the ...  

Science Conference Proceedings (OSTI)

zone adjacent to the fusion zone. These intergranular cracks form when liquid ...... 718, and A286 in Light Water Reactor. Environments",. J. Mater. Eng., 2, pp.

370

Research and Evaluation of Low Temperature Crack Propagation of ...  

Science Conference Proceedings (OSTI)

NRC/EPRI Welding Residual Stress Validation Program (Phase III) · On the Microstructure of Alloy 600 SCC Cracks Observed by TEM on PWR SG Pulled Tubes ...

371

DPQ Event Cracked Bushing Leads to Transformer Bank Failure  

Science Conference Proceedings (OSTI)

As part of EPRI's distribution power quality (DPQ) project this power quality (PQ) case study investigates cracked bushing recorded by PQ monitors that led to tranformer bank failure.

2003-12-31T23:59:59.000Z

372

Ranking the Susceptibility to Hydrogen-assisted Cracking in Super ...  

Science Conference Proceedings (OSTI)

Thus, SDSS welds are exposed to hydrogen charging to under CP. There have been reported hydrogen assisted cracking (HAC) failures in SDSS welds during ...

373

Hydrogen Induced Cracking Susceptibility of Titanium Alloys in ...  

Science Conference Proceedings (OSTI)

May 16, 2007 ... This report evaluates hydrogen-induced cracking (HIC) susceptibility of titanium alloys in environments anticipated in the Yucca Mountain ...

374

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

Open Energy Info (EERE)

P wave anisotropy, stress, and crack distribution at Coso geothermal field, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: P wave...

375

Failure Analysis of a Cracked Thermite Welded Rail Section  

Science Conference Proceedings (OSTI)

Brittle fracture followed the fatigue crack propagation causing complete separation of the rail. Although the excess material was thought to reinforce the rails it ...

376

High-Temperature Stress Relaxation Cracking and Stress Rupture ...  

Science Conference Proceedings (OSTI)

An incident occurred that resulted in the cracking of gasifier internals, bulging and stress rupture of the shell and the escape of hot syngas, causing a fire.

377

Corrosion Fatigue and Crack Propagation of Different Austenitic ...  

Science Conference Proceedings (OSTI)

A FIB Study of the Resistance of Grain Boundaries to Short Fatigue Crack Propagation in Three-Dimensions in High Strength Al Alloys · A Non-Linear Damage ...

378

Effect of Interstitial Content on High Temperature Fatigue Crack ...  

Science Conference Proceedings (OSTI)

instance; resulted in fatigue crack propagation (FCP)' programs like ESDADTA(2) and ENSIP(3). Fatigue resistance of nickel base superalloys is affected by ...

379

Fatigue and Fatigue Crack Propagation Behaviors of High ...  

Science Conference Proceedings (OSTI)

The S-N fatigue and fatigue crack propagation (FCP) behaviors of high ... The mechanisms associated with the improved fatigue resistance for the high ...

380

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

SciTech Connect

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

Chung, H.M.; Sanecki, J.E. [Argonne National Lab., IL (United States); Garner, F.A. [Pacific Northwest National Lab., Richland, WA (United States)

1996-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Short-Crack Response of Alloy 182 Weld Metal Undergoing Stress Corrosion Cracking in High-Temperature PWR Primary Water  

Science Conference Proceedings (OSTI)

Mechanistic investigations of environmentally assisted cracking (EAC), to date, have focused more on propagation relative to initiation. At the same time, components spend most of their life in the initiation and "short-crack" growth regimes. Prior exploratory work conducted at General Electric Global Research Center (GE GRC) showed that stainless steels, Alloy 600, and Alloy 182 weld metal exhibit lower average growth rates when the cracks are very short or small (1050 m). In those tests, the transition...

2008-10-31T23:59:59.000Z

382

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

Science Conference Proceedings (OSTI)

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

Singbeil, D.L.; Prescott, R. [Pulp and Paper Research Inst. of Canada, Vancouver, British Columbia (Canada); Keiser, J.R.; Swindeman, R.W. [Oak Ridge National Lab., TN (United States)

1997-07-01T23:59:59.000Z

383

Stress Corrosion Cracking of the Drip Shield, the Waste Package Outer Barrier, and the Stainless Steel Structural Material  

Science Conference Proceedings (OSTI)

Stress corrosion cracking is one of the most common corrosion-related causes for premature breach of metal structural components. Stress corrosion cracking is the initiation and propagation of cracks in structural components due to three factors that must be present simultaneously: metallurgical susceptibility, critical environment, and static (or sustained) tensile stresses. This report was prepared according to ''Technical Work Plan for: Regulatory Integration Modeling and Analysis of the Waste Form and Waste Package'' (BSC 2004 [DIRS 171583]). The purpose of this report is to provide an evaluation of the potential for stress corrosion cracking of the engineered barrier system components (i.e., the drip shield, waste package outer barrier, and waste package stainless steel inner structural cylinder) under exposure conditions consistent with the repository during the regulatory period of 10,000 years after permanent closure. For the drip shield and waste package outer barrier, the critical environment is conservatively taken as any aqueous environment contacting the metal surfaces. Appendix B of this report describes the development of the SCC-relevant seismic crack density model (SCDM). The consequence of a stress corrosion cracking breach of the drip shield, the waste package outer barrier, or the stainless steel inner structural cylinder material is the initiation and propagation of tight, sometimes branching, cracks that might be induced by the combination of an aggressive environment and various tensile stresses that can develop in the drip shields or the waste packages. The Stainless Steel Type 316 inner structural cylinder of the waste package is excluded from the stress corrosion cracking evaluation because the Total System Performance Assessment for License Application (TSPA-LA) does not take credit for the inner cylinder. This document provides a detailed description of the process-level models that can be applied to assess the performance of Alloy 22 (used for the waste package outer barrier) and Titanium Grade 7 (used for the drip shield) that are subjected to the effects of stress corrosion cracking. The use of laser peening or other residual stress mitigation techniques is considered as a means of mitigating stress corrosion cracking in the waste package final closure lid weld.

G. Gordon

2004-10-13T23:59:59.000Z

384

Thermal fatigue behavior of US and Russian grades of beryllium  

Science Conference Proceedings (OSTI)

A novel technique has been used to test the relative low cycle thermal fatigue resistance of different grades of US and Russian beryllium which is proposed as plasma facing armor for fusion reactor first wall, limiter, and divertor components. The 30 KW electron beam test system at Sandia National Laboratories was used to sweep the beam spot along one direction at 1 Hz. This produces a localized temperature ``spike`` of 750{degrees}C for each pass of the beam. Large thermal stress in excess of the yield strength are generated due to very high spot heat flux, 250 MW/m{sup 2}. Cyclic plastic strains on the order of 0.6% produced visible cracking on the heated surface in less than 3000 cycles. An in-vacuo fiber optic borescope was used to visually inspect the beryllium surfaces for crack initiation. Grades of US beryllium tested included: S-65C, S-65H, S-200F, S-300F-H, Sr-200, I-400, extruded high purity. HIP`d sperical powder, porous beryllium (94% and 98% dense), Be/30% BeO, Be/60% BeO, and TiBe{sub 12}. Russian grades included: TGP-56, TShGT, DShG-200, and TShG-56. Both the number of cycles to crack initiation, and the depth of crack propagation, were measured. The most fatigue resistant grades were S-65C, DShG-200, TShGT, and TShG-56. Rolled sheet Be(SR-200) showed excellent crack propagation resistance in the plane of rolling, despite early formation of delamination cracks. Only one sample showed no evidence of surface melting, Extruded (T). Metallographic and chemical analyses are provided. Good agreement was found between the measured depth of cracks and a 2-D elastic-plastic finite element stress analysis.

Watson, R.D.; Youchison, D.L. [Sandia National Labs., Albuquerque, NM (United States); Dombrowski, D.E. [Brush Wellman, Inc., Cleveland, OH (United States); Guiniatouline, R.N. [Efremov Institute, St. Petersburg (USSR); Kupriynov, I.B. [Russian Inst. of Inorganic Materials, Moscow (USSR)

1996-02-01T23:59:59.000Z

385

Evaluation of Circumferential Cracking on Supercritical Boiler Waterwalls  

Science Conference Proceedings (OSTI)

Circumferential cracking of the fireside surfaces of supercritical waterwalls remains a problem for many coal-fired boilers. Two parallel test programs at Pennsylvania Power and Light's (PPL) Brunner Island Unit 3 attempted to correlate operating conditions with the development and propagation of circumferential cracks.

2008-03-31T23:59:59.000Z

386

Micro-crack Damage Evolution of Fracturing Rock Chaotic Characteristics  

Science Conference Proceedings (OSTI)

Chaotic theory and bifurcation of modern nonlinear science were used to study the evolution of micro-cracks under the hydraulic fracturing of the rock mass characteristics, the tensor damage variable which described the chao evolution of micro-cracks ... Keywords: chaos theory, bifurcation theory, damage evolution

Zhaowan Chun; Wang Tingting

2010-06-01T23:59:59.000Z

387

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

E-Print Network (OSTI)

with inherently tight crack widths, typically less than 80 micron, even when strained up to 5% in uniaxial tension to undergo large deformations while maintaining load capacity. Of interest to this study are the tight crack mixture. Mixing proportions of both materials are shown in Table 1. The sand used in ECC had an average

Lepech, Michael D.

388

Fatigue-crack propagation behavior of Inconel 718  

DOE Green Energy (OSTI)

The techniques of linear-elastic fracture mechanics were used to characterize the effect of several variables (temperature, environment, cyclic frequency, stress ratio, and heat-treatment variations) upon the fatigue-crack growth behavior of Inconel 718 base metal and weldments. Relevant crack growth data on this alloy from other laboratories is also presented. (33 fig, 39 references) (auth)

James, L.A.

1975-09-01T23:59:59.000Z

389

Measurement of rising R-curve behavior in toughened silicon nitride by stable crack propagation in bending  

SciTech Connect

A simple procedure for measuring the R-curve properties of ceramics by a stable fracture test in three-point bending is described. As a typical case, data are displayed for a Si{sub 3}N{sub 4} material toughened by the presence of acicular grains in situ grown during the sintering process. The fracture mechanics specimen was a single-edge double-notched beam (SEDNB), whose notch was sharpened to a radius of < 10 {micro}m in order to reduce the amount of elastic energy stored at its root prior to crack extension. Furthermore, a stabilizer, specially designed for the bending geometry, was used to control crack stability. During stable extension, the crack could be easily arrested at selected locations of the load-displacement curve, the load quickly released, and the stable crack extension directly measured by the die-penetration technique. The crack resistance, K{sub R}, of the material was calculated from the measured crack extent and the onset load value before unloading. This method enabled them to precisely monitor the critical load value at which the load-displacement curve deviated from linear behavior, as well as crack extensions from a few tens of micrometers to about 1 mm. As an application of this method, the fracture resistance of a Si{sub 3}N{sub 4} material with rising R-curve behavior was measured and found to increase from about 5.5 to 9.0 MPa {center_dot} m{sup 1/2} within a 0.8-mm extension.

Nishida, Toshihiko; Hanaki, Yoshikazu [Kyoto Inst. of Tech. (Japan). Dept. of Materials; Nojima, Taketoshi [Kyoto Univ. (Japan). Dept. of Aeronautical Engineering; Pezzotti, G. [Toyohashi Univ. of Technology (Japan). Dept. of Materials Science

1995-11-01T23:59:59.000Z

390

Fatigue Crack Closure and Corrosion Fatigue in Al 7075 Alloy Using ...  

Science Conference Proceedings (OSTI)

Traditional methods to quantify crack closure load, such as load-displacement curves, are not very accurate. In this study, the degree of crack closure through ...

391

A Study on Fatigue-Crack-Deformation Behavior Following a Single ...  

Science Conference Proceedings (OSTI)

Apr 27, 2009 ... Width. Using this method, the respective crack—opening load (COL) at various crack-growth stages can be determined ?om the curve of the ...

392

Induction Heating Stress Improvement Effectiveness on Crack Growth in Operating Plants (BWRVIP-61)  

Science Conference Proceedings (OSTI)

New reports of intergranular stress corrosion cracking prompted this review of factors that could influence the performance of the pipe cracking remedy known as induction heating stress improvement.

1999-01-27T23:59:59.000Z

393

Assessment of Crack in Corrosion Defects in Natural Gas Transmission Pipelines.  

E-Print Network (OSTI)

??Pipelines are one of the safest forms of transportation for oil and gas. However, pipelines may experience some defects, such as cracks, corrosion and cracks… (more)

Hosseini, Seyed Aliakbar

2010-01-01T23:59:59.000Z

394

MacroscoMacroscopic Cracking Determination in LaBS Glasspic Cracking Determination in LaBS Glass  

SciTech Connect

The DOE/EM plans to conduct the Plutonium Vitrification Project at the Savannah River Site (SRS). An important part of this project is to reduce the attractiveness of the plutonium by fabricating a plutonium glass form and immobilizing the Pu form within the high level waste (HLW) glass prepared in the Defense Waste Processing Facility (DWPF). This requires that a project schedule that is consistent with EM plans for DWPF and cleanup of the SRS be developed. Critical inputs to key decisions in the vitrification project schedule are near-term data that will increase confidence that the lanthanide borosilicate (LaBS) glass product is suitable for disposal in the Yucca Mountain Repository. A workshop was held on April 28, 2005 at Bechtel SAIC Company (BSC) facility in Las Vegas, NV to define the near term data needs. Dissolution rate data and the fate of plutonium oxide and the neutron absorbers during the dissolution process were defined as key data needs. A suite of short-term tests were defined at the workshop to obtain the needed data. The objectives of these short-term tests are to obtain data that can be used to show that the dissolution rate of a LaBS glass is acceptable and to show that the extent of Pu separation from neutron absorbers, as the glass degrades and dissolves, is not likely to lead to criticality concerns. An additional data need was identified regarding the degree of macroscopic cracking and/or voiding that occurs during processing of the Pu glass waste form and subsequent pouring of HLW glass in the DWPF. A final need to evaluate new frit formulations that may increase the durability of the plutonium glass and/or decrease the degree to which neutron absorbers separate from the plutonium during dissolution was identified. This task plan covers the need to evaluate the degree of macroscopic cracking and/or voiding that occurs during processing of the Vitrified Plutonium Waste Form (i.e. the can-in-canister configuration containing the vitrified Pu product). Separate task plans were developed for Pu glass performance testing of the current baseline LaBS glass composition and development of alternative frit formulations. Recent results from Pressurized Unsaturated Flow (PUF) testing showed the potential separation of Pu from Gd during the glass dissolution process [3]. Post-test analysis of the LaBS glass from a 6-year PUF test showed a region where Pu had apparently accumulated in a Pu-bearing disk-like phase that had become separated from neutron absorber (Gd). It should be noted that this testing was conducted on the early LaBS Frit A glass composition that was devoid of HfO{sub 2} as a neutron absorber. PUF testing is currently being initiated using the LaBS Frit B composition that contains HfO{sub 2}. The potential for fissile material and neutron absorber separation is a criticality risk for the repository. The surface area that is available for leaching (i.e. due to the degree of cracking or voiding within the Pu glass cylinder) is a factor in modeling the amount of fissile material and neutron absorber released during the dissolution process. A mathematical expression for surface area is used in the Total Systems Performance Assessment (TSPA) performed by BSC personnel. Specifically, the surface area available for leaching is being used in current external criticality assessments. The planned processing steps for producing a VPWF assembly involves processing Pu feed and LaBS frit to produce a can of Pu LaBS glass, packaging this can into a second can (i.e. bagless transfer) for removal from the glovebox processing environment, placing a series of bagless transfer cans into a DWPF canister, and pouring HLW glass into the DWPF canister to encapsulate bagless transfer cans. The objective of this task is to quantify the degree of cracking and/or voiding that will occur during the processing of the VPWF.

Marra, James

2005-08-01T23:59:59.000Z

395

Materials Reliability Program: Thermal Fatigue Monitoring Guidelines (MRP-32, Revision 1)  

Science Conference Proceedings (OSTI)

This report provides thermal fatigue monitoring guidelines for attached piping systems in which there might be high potential for thermal fatigue cracking. The Materials Reliability Program (MRP) has published guidance under the Nuclear Energy Institute (NEI) 03-08 materials initiative for addressing potential thermal fatigue cycling in non-isolable reactor coolant system branch lines. This guidance calls for monitoring, inspection, and/or fatigue analysis of susceptible lines.

2011-06-16T23:59:59.000Z

396

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

SciTech Connect

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

Ostapenko, Sergei

2013-04-03T23:59:59.000Z

397

Influence of the material substructure on crack propagation: a unified treatment  

E-Print Network (OSTI)

The influence of the material texture (substructure) on the force driving the crack tip in complex materials admitting Ginzburg-Landau-like energies is analyzed in a three-dimensional continuum setting. The theory proposed accounts for finite deformations and general coarse-grained order parameters. A modified expression of the J-integral is obtained together with other path-integrals which are necessary to treat cases where the process zone around the tip has finite size. The results can be applied to a wide class of material substructures. As examples, cracks in ferroelectrics and in materials with strain-gradient effects are discussed: in these cases the specializations of the general results fit reasonably experimental data.

Paolo Maria Mariano

2003-05-02T23:59:59.000Z

398

Catalytic cracking of aromatic hydrocarbons. Final report, October 1984-March 1986  

SciTech Connect

Iron containing minerals and chars were screened as cracking catalysts for aromatic hydrocarbons (AHC) in simulated gasifier effluents. Catalytic activities of six minerals and two chars were measured and used to infer fundamental hetereogeneous rate constants using measured properties of the pore structure of the solids. Measurements were made for 200 ppM and 2000 ppM benzene cracking over the temperature range 400 to 1000/sup 0/C. The active catalyst under gasifier conditions was found to be FeO. The minerals have a higher reactivity per unit mass in chars than in a pure form. H/sub 2/S was found to reduce the catalytic activity to one third of the unpoisoned value, but the catalysts maintained this reduced activity. These minerals have the potential to be economically feasible, disposable catalysts in a fixed bed or fluidized bed process if they can survive for ten hours. 8 refs., 33 figs., 3 tabs.

Simons, G.A.; Ham, D.O.; Moniz, G.A.

1986-04-01T23:59:59.000Z

399

Analysis of Alloy 600 and X-750 stress corrosion cracks  

Science Conference Proceedings (OSTI)

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

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

1993-06-01T23:59:59.000Z

400

Thermal spallation drilling  

DOE Green Energy (OSTI)

Thermal spallation drilling is an underdeveloped process with great potential for reducing the costs of drilling holes and mining shafts and tunnels in most very hard rocks. Industry has used this process to drill blast holes for emplacing explosives and to quarry granite. Some theoretical work has been performed, and many signs point to a great future for this process. The Los Alamos National Laboratory has studied the theory of the spallation process and is conducting experiments to prove out the system and to adapt it for use with a conventional rotary rig. This report describes work that has been accomplished at the Laboratory on the development of thermal spallation drilling and some work that is projected for the future on the system. 3 references, 3 figures.

Williams, R.E.

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Factors Affecting the Hydrogen Environment Assisted Cracking Resistance of an Al-Zn-Mg-(Cu) Alloy  

DOE Green Energy (OSTI)

It is well established that Al-Zn-Mg-(Cu) aluminum alloys are susceptible to hydrogen environment assisted cracking (HEAC) when exposed to aqueous environments. In Al-Zn-Mg-Cu alloys, overaged tempers are commonly used to increase HEAC resistance at the expense of strength. Overaging has little benefit in low copper alloys. However, the mechanism or mechanisms by which overaging imparts HEAC resistance is poorly understood. The present research investigated hydrogen uptake, diffusion, and crack growth rate in 90% relative humidity (RH) air for both a commercial copper bearing Al-Zn-Mg-Cu alloy (AA 7050) and a low copper variant of this alloy in order to better understand the factors which affect HEAC resistance. Experimental methods used to evaluate hydrogen concentrations local to a surface and near a crack tip include nuclear reaction analysis (NRA), focused ion beam, secondary ion mass spectroscopy (FIB/SIMS) and thermal desorption spectroscopy (TDS). When freshly bared coupons of AA 7050 are exposed to 90 C, 90% RH air, hydrogen ingress follows inverse-logarithmic-type kinetics and is equivalent for underaged (HEAC susceptible) and overaged (HEAC resistant) tempers. However, when the native oxide is allowed to form (24 hrs in 25 C, 40% RH lab air) prior to exposure to 90 C, 90% RH air, underaged alloy shows significantly greater hydrogen ingress than the overaged alloy. Humid air is a very aggressive environment producing local ({approx}1{micro}m) hydrogen concentrations in excess of 10,000 wt. ppm at 90 C. In the copper bearing alloy, overaging also effects the apparent diffusivity of hydrogen. As AA 7050 is aged from underaged {yields} peak aged {yields} overaged, the activation energy for hydrogen diffusion increases and the apparent diffusivity for hydrogen decreases, In the low copper alloy, overaging has little effect on hydrogen diffusion. Comparison of the apparent activation energies for hydrogen diffusion and for K independent (stage II) crack growth rate in 90% RH air between 25 and 90 C indicates that hydrogen transport kinetics are responsible for the decreased crack growth rate of overaged AA 7050 relative to the peak aged temper.

G.A. Young; J.R. Scully

2001-09-12T23:59:59.000Z

402

The selective catalytic cracking of Fischer-Tropsch liquids to high value transportation fuels. Final report  

DOE Green Energy (OSTI)

Amoco Oil Company, investigated a selective catalytic cracking process (FCC) to convert the Fischer-Tropsch (F-T) gasoline and wax fractions to high value transportation fuels. The primary tasks of this contract were to (1) optimize the catalyst and process conditions of the FCC process for maximum conversion of F-T wax into reactive olefins for later production of C{sub 4}{minus}C{sub 8} ethers, and (2) use the olefin-containing light naphtha obtained from FCC processing of the F-T wax as feedstock for the synthesis of ethers. The catalytic cracking of F-T wax feedstocks gave high conversions with low activity catalysts and low process severities. HZSM-5 and beta zeolite catalysts gave higher yields of propylene, isobutylene, and isoamylenes but a lower gasoline yield than Y zeolite catalysts. Catalyst selection and process optimization will depend on product valuation. For a given catalyst and process condition, Sasol and LaPorte waxes gave similar conversions and product selectivities. The contaminant iron F-T catalyst fines in the LaPorte wax caused higher coke and hydrogen yields.

Schwartz, M.M.; Reagon, W.J.; Nicholas, J.J.; Hughes, R.D.

1994-11-01T23:59:59.000Z

403

Improved load ratio method for predicting crack length  

SciTech Connect

The elastic compliance from unloading/reloading sequences in a load-displacement record estimates well crack length in elastic-plastic fracture toughness tests of compact tension [C(T)] and bending type specimens. The need for partial unloading of the specimen makes it difficult to run the test under static loading and impossible under either dynamic loading or very high temperatures. Furthermore, fracture toughness testing in which crack length is determined from elastic compliance requires high precision testing equipment and highly skilled technicians. As a result, such tests are confined usually to research laboratories and seldom used under production settings. To eliminate these problems, an improved load ratio method of predicting crack length is proposed that utilizes only the recorded load versus load-line displacement curve (or load versus crack-mouth-opening displacement curve) without unloading/reloading sequences. As a result, the instrumentation is much simpler than in the elastic compliance or potential drop methods. If only a monotonic load-displacement record is to be measured the fracture toughness test becomes almost as simple to perform as a tension test. The method described here improves in three ways the ``original load ratio method`` proposed by Hu et al. First, a blunting term is added to the crack length before maximum load. Second, a strain hardening correction is included after maximum load. And, third, the initial crack length and the physical (final) crack length measured at the end of the test serve to anchor the predicted crack lengths, forcing agreement between predicted and measured values. The method predicts crack extension with excellent accuracy in specimens fabricated from A302, A508, and A533B piping and pressure vessel steels, A588 and A572 structural steels, and HY-80 ship steel.

Chen, X.; Albrecht, P. [Univ. of Maryland, College Park, MD (United States). Inst. for Systems Research; Wright, W. [Federal Highway Administration, McLean, VA (United States). Turner-Fairbank Highway Research Center; Joyce, J.A. [Naval Academy, Annapolis, MD (United States). Mechanical Engineering Dept.

1995-04-01T23:59:59.000Z

404

Examination of cracked turbine discs from nuclear power plants  

SciTech Connect

Investigations were performed on a cracked turbine disc from the Cooper Nuclear Power Station (BWR), and on two failed turbine discs from the Yankee-Rowe Nuclear Power Station (PWR). The Yankee-Rowe discs were subjected to SEM/EDAX, uniaxial tension tests, hardness testing, notch sensitivity tests, and environmental notched tensile tests. The results of this investigation support the model whereby the cracks initiated at startup of the turbine, probably from H/sub 2/S produced by hydrolysis of MoS/sub 2/, and grew at a rate consistent with published data for propagation of cracks in pure steam.

Czajkowski, C.J.; Weeks, J.R.

1983-03-01T23:59:59.000Z

405

Shale oil cracking. 2. Effect on oil composition  

DOE Green Energy (OSTI)

Results from spectroscopic investigations are presented that demonstrate the effect of oil cracking on shale oil composition. Techniques used include infrared spectroscopy, capillary column gas chromatography/mass spectroscopy and /sup 13/C nuclear magnetic resonance. We show that cracking causes an increase in aromatic and alkene content of the oil. We compare our results for oils prepared in the laboratory with oils prepared in the TOSCO-II semi-works and in modified and true-in-situ combustion retorts. We demonstrate that the napthalene/2-methyl-naphthalene ratio is a good indicator of cracking conditions in an oil shale retort.

Burnham, A.K.; Sanborn, R.H.; Crawford, R.W.; Newton, J.C.; Happe, J.A.

1980-08-01T23:59:59.000Z

406

Evaluation of Cracks in ABB HK Arc Chutes  

Science Conference Proceedings (OSTI)

The nuclear power industry has a number of medium voltage (5 Kv-15 Kv) ABB HK air-magnetic circuit breakers with cracks in various places on the ceramic liner plate and cold-molded asbestos portions of the arc chutes. These cracks may or may not be cosmetic. This "jump gap crack" issue has been discussed in several ABB circuit breaker users group meetings. Five utilities (Brunswick, Seabrook, TVA, Duke, and Vogtle) have previously expressed interest in this issue. The present ABB Quality Assurance Proced...

2005-05-03T23:59:59.000Z

407

Control of growth and the processes of energy transfer from CdSe quantum dots for Nd{sup 3+} ions in a vitreous system: Thermal annealing time  

SciTech Connect

The authors report clear evidence of radiative and nonradiative energy transfer from CdSe quantum dots to Nd{sup 3+} ions in a glass system synthesized by melting method. An efficient control of energy transfer can be obtained by controlling the mean radius of the CdSe quantum dots. Increase of about 100% of the near infrared Nd{sup 3+} emission ({sup 4}F{sub 3/2}{yields}{sup 4}I{sub 9/2}) was observed as a function of thermal annealing time.

Dantas, N. O.; Serqueira, E. O. [Laboratorio de Novos Materiais Isolantes e Semicondutores-LNMIS, Instituto de Fisica, Universidade Federal de Uberlandia, 38400-902 Uberlandia, Minas Gerais (Brazil); Anjos, V.; Bell, M. J. V. [Grupo de Espectroscopia de Materiais, Departamento de Fisica, Universidade Federal de Juiz de Fora, 36036-330 Juiz de Fora, Minas Gerais (Brazil)

2012-09-17T23:59:59.000Z

408

Measurement of Thermal Diffusity and Flow Resistance for TCAP Materials  

DOE Green Energy (OSTI)

SRS uses the Thermal Cycling Absorption Process (TCAP) to separate isotopes of hydrogen. The frequency of thermal cycles is a limit of the productivity of the process and that frequency is largely determined by the thermal diffusivity of the absorbent material. For a given tube diameter, a larger thermal diffusivity decreases the time required for each cycle. In 1998, the Engineering Development Laboratory measured thermal diffusivity and thermal conductivity for three TCAP materials in helium.

STEIMKE, JOHN

2004-11-11T23:59:59.000Z

409

Coal liquefaction process  

DOE Patents (OSTI)

An improved coal liquefaction process is provided which enables conversion of a coal-oil slurry to a synthetic crude refinable to produce larger yields of gasoline and diesel oil. The process is characterized by a two-step operation applied to the slurry prior to catalytic desulfurization and hydrogenation in which the slurry undergoes partial hydrogenation to crack and hydrogenate asphaltenes and the partially hydrogenated slurry is filtered to remove minerals prior to subsequent catalytic hydrogenation.

Karr, Jr., Clarence (Morgantown, WV)

1977-04-19T23:59:59.000Z

410

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

DOE Green Energy (OSTI)

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.

Yue Kuo

2010-08-15T23:59:59.000Z

411

Strategies for planar crack propagation based on the concept of material forces  

Science Conference Proceedings (OSTI)

This paper presents a computational framework for the simulation of planar crack growth (including kinking) driven by "material forces". An evolution law for the crack tip position is formulated, which is shown to give rise to different propagation strategies ... Keywords: Configurational forces, Crack curving, Crack propagation

Jim Brouzoulis; Fredrik Larsson; Kenneth Runesson

2011-03-01T23:59:59.000Z

412

Thermal energy storage application areas  

DOE Green Energy (OSTI)

The use of thermal energy storage in the areas of building heating and cooling, recovery of industrial process and waste heat, solar power generation, and off-peak energy storage and load management in electric utilities is reviewed. (TFD)

Not Available

1979-03-01T23:59:59.000Z

413

Environmentally Assisted Cracking of Ni-Base Alloys [Corrosion and  

NLE Websites -- All DOE Office Websites (Extended Search)

LWRs > Environmentally Assisted LWRs > Environmentally Assisted Cracking of Ni-Base Alloys Capabilities Materials Testing Environmentally Assisted Cracking (EAC) of Reactor Materials Corrosion Performance/Metal Dusting Overview Light Water Reactors Fatigue Testing of Carbon Steels and Low-Alloy Steels Environmentally Assisted Cracking of Ni-Base Alloys Irradiation-Induced Stress Corrosion Cracking of Austenitic Stainless Steels Steam Generator Tube Integrity Program Air Oxidation Kinetics for Zr-based Alloys Fossil Energy Fusion Energy Metal Dusting Publications List Irradiated Materials Steam Generator Tube Integrity Other Facilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Corrosion and Mechanics of Materials Light Water Reactors

414

Irradiation-Induced Stress Corrosion Cracking of Austenitic Stainless  

NLE Websites -- All DOE Office Websites (Extended Search)

Environmentally Assisted Environmentally Assisted Cracking of Ni-Base Alloys Capabilities Materials Testing Environmentally Assisted Cracking (EAC) of Reactor Materials Corrosion Performance/Metal Dusting Overview Light Water Reactors Fatigue Testing of Carbon Steels and Low-Alloy Steels Environmentally Assisted Cracking of Ni-Base Alloys Irradiation-Induced Stress Corrosion Cracking of Austenitic Stainless Steels Steam Generator Tube Integrity Program Air Oxidation Kinetics for Zr-based Alloys Fossil Energy Fusion Energy Metal Dusting Publications List Irradiated Materials Steam Generator Tube Integrity Other Facilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Corrosion and Mechanics of Materials Light Water Reactors Bookmark and Share

415

Crack coalescence in rock-like material under cycling loading  

E-Print Network (OSTI)

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

Ko, Tae Young, 1973-

2005-01-01T23:59:59.000Z

416

Evaluation of Stress Corrosion Cracking Susceptibility of Drill Pipe ...  

Science Conference Proceedings (OSTI)

G-105 and S-135 grades of drill pipe steels have been used to study the effect of temperature and solution chemistry on the stress corrosion cracking behavior of ...

417

Effect of Oxygen Potential on Crack Growth in Alloy 617  

Science Conference Proceedings (OSTI)

Static crack growth rate increases from 4 x 10-9 m/sec to 4 x 10-8 m/sec when the oxygen concentration decreases from .001 to .0000001 atm. Proceedings ...

418

3D Characterization and Modeling of Fatigue Cracks  

Science Conference Proceedings (OSTI)

The HEDM and CT are performed with high energy x-rays at the Advanced Photon Source (APS). One set of LSHR specimens has small cracks on the order of ...

419

SLAC National Accelerator Laboratory - SLAC Research Cracks Puzzle...  

NLE Websites -- All DOE Office Websites (Extended Search)

Press Release Archive SLAC Research Cracks Puzzle of Enzyme Critical to Food Supply November 17, 2011 Menlo Park, Calif. - If we could make plant food from nitrogen the way nature...

420

Temperature dependence of the intrinsic small fatigue crack growth behavior in Ni-base superalloys based on measurement of crack closure  

Science Conference Proceedings (OSTI)

The effect of temperature on the small fatigue crack growth behavior of a single crystal and directionally solidified Ni-base superalloys was investigated at temperatures between 873 to 1,123 K by measuring the crack closure. The results were also compared with those of the physically long crack. It was found that the propagation resistance and the fatigue threshold of the long cracks increased with temperature in all the materials. The long crack growth rates at three temperatures were approximately represented by an unique curve, after taking account of crack closure level and elastic modulus. In contrast, the small crack growth resistance decreased with temperature even when the crack closure phenomenon was taken into consideration. Furthermore, the small fatigue cracks exhibited considerably higher growth rates than the long cracks at a given effective stress intensity factor range and also grew under effective stress intensity factor ranges below the long crack threshold. The factors responsible for the lack of similitude in propagation rates between small and long cracks were also discussed, based on these observations and the chemical analysis near the crack tip using the electron probe microanalyzer.

Okazaki, M.; Yamada, H. [Nagaoka Univ. of Technology (Japan). Dept. of Mechanical Engineering; Nohmi, S. [Kawasaki Heavy Industries Co. Ltd., Akashi (Japan)

1996-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Crack reconstruction using a level-set strategy  

Science Conference Proceedings (OSTI)

We present a level-set based technique to recover key characteristics of a defect or crack (e.g. location, length and shape) in a two-dimensional material from boundary electrical measurements. The key feature of this work is to extend the usual level-set ... Keywords: 02.30.Zz, 41.20.Cv, 42.30.Wb, Crack reconstruction, Electrical impedance tomography, Level-sets

Diego Álvarez; Oliver Dorn; Natalia Irishina; Miguel Moscoso

2009-09-01T23:59:59.000Z

422

Thermal Conversion of Methane to Acetylene  

DOE Green Energy (OSTI)

This report describes the experimental demonstration of a process for the direct thermal conversion of methane to acetylene. The process utilizes a thermal plasma heat source to dissociation products react to form a mixture of acetylene and hydrogen. The use of a supersonic expansion of the hot gas is investigated as a method of rapidly cooling (quenching) the product stream to prevent further reaction or thermal decomposition of the acetylene which can lower the overall efficiency of the process.

Fincke, James Russell; Anderson, Raymond Paul; Hyde, Timothy Allen; Wright, Randy Ben; Bewley, Randy Lee; Haggard, Delon C; Swank, William David

2000-01-01T23:59:59.000Z

423

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

Science Conference Proceedings (OSTI)

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

Lienert, Thomas J [Los Alamos National Laboratory

2010-12-09T23:59:59.000Z

424

Modeling the steady-state ISV (in situ vitrification) process: A 3-D finite element analysis of coupled thermal-electric fields  

Science Conference Proceedings (OSTI)

Steady-state modeling considerations for simulating the in situ vitrification (ISV) process are documented based upon the finite element numerical approach. Recommendations regarding boundary condition specifications and mesh discretization are presented. The effects of several parameters on the ISV process response are calculated and the results discussed. The parameters investigated include: (1) electrode depth, (2) ambient temperature, (3) supplied current, (4) electrical conductivity, (5) electrode separation, and (6) soil/waste characterization. 13 refs., 29 figs., 1 tab.

Langerman, M.A.

1990-09-01T23:59:59.000Z

425

Thermal Properties  

Science Conference Proceedings (OSTI)

Table 12   Thermal conductivities of polymers and other materials...40,000 2.8 Aluminum 24,000 1.7 Steel 5000 0.35 Granite 350 0.02 Crown glass (75 wt% silica) 90 0.006 Source: Ref 4...

426

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

DOE Patents (OSTI)

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

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

2003-02-11T23:59:59.000Z

427

Degradation of Structural Alloys Under Thermal Insulation  

E-Print Network (OSTI)

Wet thermal insulation may actively degrade steel and stainless steel structures by general corrosion or stress-corrosion cracking. Two different mechanisms of water ingress into insulation are discussed; flooding from external sources, and migration from condensation of atmospheric moisture. The general corrosion rate of steels under insulation is predictable (within a broad scatter band) on the basis of temperature and oxygen content. This relationship is presented graphically based on plant case histories. Rainwater, washwater and the insulation itself are compared as potential sources of chloride to promote external SCC of stainless steels. Preventative measures will be discussed.

McIntyre, D. R.

1984-01-01T23:59:59.000Z

428

Fractography of Thermally Shocked Glass Cookware  

Science Conference Proceedings (OSTI)

Fractography of fractured glass cookware can be a time consuming process of putting ... to Conduct Thermal Shock Test on Refractories Using Steel Blocks.

429

Thermal conductivity of mass-graded graphene flakes  

E-Print Network (OSTI)

In this letter we investigate thermal conductions in mass-graded graphene flakes by nonequilibrium molecular dynamics simulations. It shows mass-graded graphene flakes reveal no thermal rectification effect in thermal conduction process. Dependences of thermal conductivity upon the heat fluxes and the mass gradients are studied. It is found that thermal conductivity would be dramatically decreased by increasing the mass gradients. We also discuss the influence of thermal curvatures and thermal expansions upon the thermal conduction process in mass-graded graphene flakes.

Cheh, Jigger

2011-01-01T23:59:59.000Z

430

Office of Fossil EnergyTOPICAL REPORT: DEVELOPMENT OF CFD_BASED SIMULATION TOOLS FOR IN SITU THERMAL PROCESSING OF OIL SHALE/SANDS  

E-Print Network (OSTI)

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof. In our research, we are taking the novel approach of developing and applying high performance computing, computational fluid dynamics (CFD)-based simulation tools to a modified in-situ process for production of oil from oil shale. The simulation tools being developed capture the relevant physical processes and data from a large-scale system. The modified in-situ application

Michal Hradisky; Philip J. Smith; Doe Award; No. De-fe

2009-01-01T23:59:59.000Z

431

Modelling and Experimental Study of Methane Catalytic Cracking as a Hydrogen Production Technology.  

E-Print Network (OSTI)

??Production of hydrogen is primarily achieved via catalytic steam reforming, partial oxidation,and auto-thermal reforming of natural gas. Although these processes are mature technologies, they are… (more)

Amin, Ashraf Mukhtar Lotfi

2011-01-01T23:59:59.000Z

432

AQUIFER THERMAL ENERGY STORAGE  

E-Print Network (OSTI)

using aquifers for thermal energy storage. Problems outlinedmatical Modeling of Thermal Energy Storage in Aquifers,"Proceed- ings of Aquifer Thermal Energy Storage Workshop,

Tsang, C.-F.

2011-01-01T23:59:59.000Z

433

AQUIFER THERMAL ENERGY STORAGE  

E-Print Network (OSTI)

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

Tsang, C.-F.

2011-01-01T23:59:59.000Z

434

Uptake swelling and thermal expansion of CFRP tendons  

E-Print Network (OSTI)

research. Changes in the concrete cover do not have much of an influence on the maximum hoop stress generated. However, this should be treated with caution since the analysis in Figure 11 only considers elastic behaviour up to first cracking. The concrete... composites. Journal of Composite Materials, 1978, 12, No. 2, 153–168. 15. TOMPKINS S. S. Thermal expansion of selected graphite- reinforced polyimide-, epoxy- and glass-matrix composites. International Journal of Thermophysics, 1987, 8, No. 1, 119–132. 16...

Scott, P.; Lees, Janet M.

2009-08-01T23:59:59.000Z

435

Novel Ceramic Thermal Insulators Prepared by Gelation Freezing ...  

Science Conference Proceedings (OSTI)

Developing Thermal Processes with Energy Efficiency in Mind · Development of Ceramic ... Improving the Efficiency of Solar Cells · Integrating Ceramics and ...

436

Design and application of innovative site remediation technologies: Thermal destruction  

Science Conference Proceedings (OSTI)

The book covers wet air oxidation, Texaco gasification process, flameless thermal oxidation, and plasma furnaces. 17 figs., 20 tabs.

Holm, F.W.

1998-12-31T23:59:59.000Z

437

BWRVIP-196: BWR Vessel and Internals Project, Assessment of Mixing Tee Thermal Fatigue Susceptibility in BWR Plants  

Science Conference Proceedings (OSTI)

In 1998, a French pressurized water reactor (PWR) plant experienced leakage due to thermal fatigue from piping immediately downstream of a residual heat removal (RHR) heat exchanger. EPRI report 1013305, Materials Reliability Program: Assessment of RHR Mixing Tee Thermal Fatigue in PWR Plants (MRP-192), December 2006, was prepared so that owners of PWR plants could determine if their RHR piping systems might be susceptible to similar thermal fatigue cracking and if additional inspection should be recomme...

2008-09-23T23:59:59.000Z

438

Crack Surface Roughness in Three-Dimensional Random Fuse Networks  

SciTech Connect

Using large system sizes with extensive statistical sampling, we analyze the scaling properties of crack roughness and damage profiles in the three-dimensional random fuse model. The analysis of damage profiles indicates that damage accumulates in a diffusive manner up to the peak load, and localization sets in abruptly at the peak load starting from a uniform damage landscape. The global crack width scales as $W \\sim L^{0.5}$ and is consistent with the scaling of localization length $\\xi \\sim L^{0.5}$ used in the data collapse of damage profiles in the post-peak regime. This consistency between the global crack roughness exponent and the post-peak damage profile localization length supports the idea that the post-peak damage profile is predominantly due to the localization produced by the catastrophic failure, which at the same time results in the formation of the final crack. Finally, the crack width distributions can be collapsed for different system sizes and follow a log-normal distribution.

Nukala, Phani K [ORNL; Zapperi, Stefano [University of La Sapienza, Rome; Simunovic, Srdjan [ORNL

2006-01-01T23:59:59.000Z

439

Near-field thermal transistor  

E-Print Network (OSTI)

Using a block of three separated solid elements, a thermal source and drain together with a gate made of an insulator-metal transition material exchanging near-field thermal radiation, we introduce a nanoscale analog of a field-effect transistor which is able to control the flow of heat exchanged by evanescent thermal photons between two bodies. By changing the gate temperature around its critical value, the heat flux exchanged between the hot body (source) and the cold body (drain) can be reversibly switched, amplified, and modulated by a tiny action on the gate. Such a device could find important applications in the domain of nanoscale thermal management and it opens up new perspectives concerning the development of contactless thermal circuits intended for information processing using the photon current rather than the electric current.

Ben-Abdallah, Philippe

2013-01-01T23:59:59.000Z

440

FITNESS-FOR-SERVICE ASSESSMENT FOR A RADIOACTIVE WASTE TANK THAT CONTAINS STRESS CORROSION CRACKS  

SciTech Connect

Radioactive wastes are confined in 49 underground storage tanks at the Savannah River Site. The tanks are examined by ultrasonic (UT) methods for thinning, pitting, and stress corrosion cracking in order to assess fitness-for-service. During an inspection in 2002, ten cracks were identified on one of the tanks. Given the location of the cracks (i.e., adjacent to welds, weld attachments, and weld repairs), fabrication details (e.g., this tank was not stress-relieved), and the service history the degradation mechanism was stress corrosion cracking. Crack instability calculations utilizing API-579 guidance were performed to show that the combination of expected future service condition hydrostatic and weld residual stresses do not drive any of the identified cracks to instability. The cracks were re-inspected in 2007 to determine if crack growth had occurred. During this re-examination, one indication that was initially reported as a 'possible perpendicular crack <25% through wall' in 2002, was clearly shown not to be a crack. Additionally, examination of a new area immediately adjacent to other cracks along a vertical weld revealed three new cracks. It is not known when these new cracks formed as they could very well have been present in 2002 as well. Therefore, a total of twelve cracks were evaluated during the re-examination. Comparison of the crack lengths measured in 2002 and 2007 revealed that crack growth had occurred in four of the nine previously measured cracks. The crack length extension ranged from 0.25 to 1.8 inches. However, in all cases the cracks still remained within the residual stress zone (i.e., within two to three inches of the weld). The impact of the cracks that grew on the future service of Tank 15 was re-assessed. API-579 crack instability calculations were again performed, based on expected future service conditions and trended crack growth rates for the future tank service cycle. The analysis showed that the combined hydrostatic and weld residual stresses do not drive the identified cracks to instability. This tank expected to be decommissioned in the near future. However, if these plans are delayed, it was recommended that a third examination of selected cracks in the tank be performed in 2014.

Wiersma, B; James Elder, J; Rodney Vandekamp, R; Charles Mckeel, C

2009-04-23T23:59:59.000Z

Note: This page contains sample records for the topic "thermal cracking process" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Modeling Hydrogen-Induced Cracking of Titanium Alloys in Nuclear Waste Repository Environments  

DOE Green Energy (OSTI)

This paper reviews the current understanding of hydrogen-induced cracking (HIC) of Ti Grade 7 and other relevant titanium alloys within the context of the current waste package design for the repository environmental conditions anticipated within the Yucca Mountain repository. The review concentrates on corrosion processes possible in the aqueous environments expected within this site. A brief background discussion of the relevant properties of titanium alloys, the hydrogen absorption process, and the properties of passive film on titanium alloys is presented as the basis for the subsequent discussion of model developments. The key corrosion processes that could occur are addressed individually. Subsequently, the expected corrosion performance of these alloys under the specific environmental conditions anticipated at Yucca Mountain is considered. It can be concluded that, based on the conservative modeling approaches adopted, hydrogen-induced cracking of titanium alloys will not occur under nuclear waste repository conditions since there will not be sufficient hydrogen in the alloy after 10,000 years of emplacement.

F. Hua; K. Mon; P. Pasupathi; G. Gordon

2004-09-08T23:59:59.000Z

442

Advanced solar thermal technology  

SciTech Connect

The application of dish solar collectors to industrial process heat (IPH) has been reviewed. IPH represents a market for displacement of fossil fuels (10 quads/y). A 10% market penetration would indicate a substantial market for solar thermal systems. Apparently, parabolic dish systems can produce IPH at a lower cost than that of troughs or compound parabolic concentrators, even though dish fabrication costs per unit area are more expensive. Successful tests of point-focusing collectors indicate that these systems can meet the energy requirements for process heat applications. Continued efforts in concentrator and transport technology development are needed. 7 figures.

Leibowitz, L.P.; Hanseth, E.; Liu, T.M.

1982-06-01T23:59:59.000Z

443

The unbearable lightness of PIN cracking  

Science Conference Proceedings (OSTI)

We describe new attacks on the financial PIN processing API. The attacks apply to switches as well as to verification facilities. The attacks are extremely severe allowing an attacker to expose customer PINs by executing only one or two API calls per ... Keywords: API attack, EMV, HSM, IBM 3624, VISA PVV, financial PIN processing API, insider attack, phantom withdrawal, security API

Omer Berkman; Odelia Moshe Ostrovsky

2007-02-01T23:59:59.000Z

444

Characterization of geothermal reservoir crack patterns using shear-wave  

Open Energy Info (EERE)

geothermal reservoir crack patterns using shear-wave geothermal reservoir crack patterns using shear-wave splitting Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Characterization of geothermal reservoir crack patterns using shear-wave splitting Details Activities (1) Areas (1) Regions (0) Abstract: Microearthquakes recorded by a downhole, three-component seismic network deployed around the Coso, California, geothermal reservoir since 1992 display distinctive shear-wave splitting and clear polarization directions. From the polarizations the authors estimated three predominant subsurface fracture directions, and from the time delays of the split waves they determined tomographically the 3-D fracture density distribution in the reservoir. Author(s): Lou, M.; Rial, J.A. Published: Geophysics, 3/1/1997

445

Shear-wave splitting and reservoir crack characterization: the Coso  

Open Energy Info (EERE)

Shear-wave splitting and reservoir crack characterization: the Coso Shear-wave splitting and reservoir crack characterization: the Coso geothermal field Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Shear-wave splitting and reservoir crack characterization: the Coso geothermal field Details Activities (1) Areas (1) Regions (0) Abstract: This paper aims to improve current understanding of the subsurface fracture system in the Coso geothermal field, located in east-central California. The Coso reservoir is in active economic development, so that knowledge of the subsurface fracture system is of vital importance for an accurate evaluation of its geothermal potential and day-to-day production. To detect the geometry and density of fracture systems we applied the shear-wave splitting technique to a large number of

446

Cracking a Cold Case and Enduring Mystery | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Cracking a Cold Case and Enduring Mystery Cracking a Cold Case and Enduring Mystery Cracking a Cold Case and Enduring Mystery July 1, 2013 - 3:04pm Addthis Chris Brandon of the ROMACONS project collects a sample of ancient Roman concrete drilled from a breakwater in Pozzuoli Bay, near Naples, Italy. The breakwater dates back to roughly 37 B.C. | Photo courtesy of J.P. Oleson. Chris Brandon of the ROMACONS project collects a sample of ancient Roman concrete drilled from a breakwater in Pozzuoli Bay, near Naples, Italy. The breakwater dates back to roughly 37 B.C. | Photo courtesy of J.P. Oleson. Charles Rousseaux Charles Rousseaux Senior Writer, Office of Science What are the key facts? Modern concrete buildings -- most made with Portland cement -- are built to last for a hundred or so years. But Roman concrete has withstood

447

Angle of crack propagation for a vertical hydraulic fracture  

DOE Green Energy (OSTI)

Using the strain-energy-density-factor (S) theory, the positive fracture angle +theta/sub o/ (the initial fracture angle of crack propagation) of a near-vertical crack is predicted by using the opening- and sliding-mode stress-intensity factors in the presence of the overburden pressure, the least in situ horizontal principal stress, and the borehole fluid pressure. The crack spreads in the positive theta/sub o/ direction (counter-clockwise) in the plane for which S is a minimum, S/sub min/. It was verified that S/sub min/ is greater than or equal to S/sub c/. The quantity S/sub c/ is defined as the critical value of S, and remains essentially constant. Of interest is the numerical example for calculating fracture angle and the critical uniform borehole fluid pressure required to initiate fracture at such an angle for the present LASL Dry Hot Rock Geothermal Energy Program. (auth)

Sarda, J.P.; Hsu, Y.C.

1975-12-01T23:59:59.000Z

448

Stress corrosion cracking of candidate waste container materials  

SciTech Connect

Six alloys have been selected as candidate container materials for the storage of high-level nuclear waste at the proposed Yucca Mountain site in Nevada. These materials are Type 304L stainless steel (SS), Type 316L SS, Incology 825, P-deoxidized Cu, Cu-30%Ni, and Cu-7% Al. The present program has been initiated to determine whether any of these materials can survive for 300 years in the site environment without developing through-wall stress corrosion cracks, and to assess the relative resistance of these materials to stress corrosion cracking (SCC). A series of slow-strain-rate tests (SSRTs) in simulated Well J-13 water which is representative of the groundwater present at the Yucca Mountain site has been completed, and crack-growth-rate (CGR) tests are also being conducted under the same environmental conditions. 13 refs., 60 figs., 22 tabs.

Maiya, P.S.; Soppet, W.K.; Park, J.Y.; Kassner, T.F.; Shack, W.J.; Diercks, D.R.

1990-11-01T23:59:59.000Z

449

Dynamic crack initiation toughness : experiments and peridynamic modeling.  

SciTech Connect

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

Foster, John T.

2009-10-01T23:59:59.000Z

450

Session: COMPOSITES: Mechanical Properties & Processing  

Science Conference Proceedings (OSTI)

Laser Speckle technique, a high sensitive noncontact technique, was employed to measure Crack Opening Displacement (COD) and Crack Shearing ...

451

Materials Reliability Program: Lessons Learned from PWR Thermal Fatigue Management Training (MRP-83)  

Science Conference Proceedings (OSTI)

In January 2001, The EPRI Materials Reliability Program (MRP) issued an Interim Guideline (MRP-24) for the management of thermal fatigue in non-isolable piping attached to reactor coolant piping in pressurized water reactor (PWR) plants (EPRI report 1000701). To assist utility personnel in understanding the potential for thermal fatigue in this piping, the MRP also conducted plant-specific workshops at plant sites. These workshops offered training on fatigue and fatigue cracking in non-isolable piping, a...

2002-12-05T23:59:59.000Z

452

Thermal dissolution of solid fossil fuels  

Science Conference Proceedings (OSTI)

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

E.G. Gorlov [Institute for Fossil Fuels, Moscow (Russian Federation)

2007-10-15T23:59:59.000Z

453

FITNESS-FOR-SERVICE ASSESSMENT FOR A RADIOACTIVE WASTE TANK THAT CONTAINS STRESS CORROSION CRACKS  

Science Conference Proceedings (OSTI)

Radioactive wastes are confined in 49 underground storage tanks at the Savannah River Site. The tanks are examined by ultrasonic (UT) methods for thinning, pitting, and stress corrosion cracking in order to assess fitness-for-service. During an inspection in 2002, ten cracks were identified on one of the tanks. Given the location of the cracks (i.e., adjacent to welds, weld attachments, and weld repairs), fabrication details (e.g., this tank was not stress-relieved), and the service history the degradation mechanism was stress corrosion cracking. Crack instability calculations utilizing API-579 guidance were performed to show that the combination of expected future service condition hydrostatic and weld residual stresses do not drive any of the identified cracks to instability. The cracks were re-inspected in 2007 to determine if crack growth had occurred. During this re-examination, one indication that was initially reported as a 'possible perpendicular crack API-579 crack instability calculations were again performed, based on expected future service conditions and trended crack growth rates for the future tank service cycle. The analysis showed that the combined hydrostatic and weld residual stresses do not drive the identified cracks to instability. This tank expected to be decommissioned in the near future. However, if these plans are delayed, it was recommended that a third examination of selected cracks in the tank be performed in 2014.

Wiersma, B; James Elder, J; Rodney Vandekamp, R; Charles Mckeel, C

2009-04-23T23:59:59.000Z

454

Texas Inland Downstream Processing of Fresh Feed Input  

U.S. Energy Information Administration (EIA)

Process: Area: 2007 2008 2009 2010 2011 2012 View History; Catalytic Reforming : 133: 125: 131: 2010-2012: Catalytic Cracking: 173: 158: 159: 149: 162: 164: 1987-2012 ...

455

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

Science Conference Proceedings (OSTI)

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

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

2011-03-01T23:59:59.000Z

456

Thermal Shock-resistant Cement  

SciTech Connect

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

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

2012-02-01T23:59:59.000Z

457

Thermal Stabilization Blend Plan  

SciTech Connect

This Blend Plan documents the feed material items that are stored in 2736-2 vaults, the 2736-ZB 638 cage, the 192C vault, and the 225 vault that will be processed through the thermal stabilization furnaces. The purpose of thermal stabilization is to heat the material to 1000 degrees Celsius to drive off all water and leave the plutonium and/or uranium as oxides. The stabilized material will be sampled to determine the Loss On Ignition (LOI) or percent water. The stabilized material must meet water content or LOI of less than 0.5% to be acceptable for storage under DOE-STD-3013-99 specifications. Out of specification material will be recycled through the furnaces until the water or LOI limits are met.

RISENMAY, H.R.

2000-05-02T23:59:59.000Z

458

Reactor Thermal-Hydraulics  

NLE Websites -- All DOE Office Websites (Extended Search)

Thermal-Hydraulics Thermal-Hydraulics Dr. Tanju Sofu, Argonne National Laboratory In a power reactor, the energy produced in fission reaction manifests itself as heat to be removed by a coolant and utilized in a thermodynamic energy conversion cycle to produce electricity. A simplified schematic of a typical nuclear power plant is shown in the diagram below. Primary coolant loop Steam Reactor Heat exchanger Primary pump Secondary pump Condenser Turbine Water Although this process is essentially the same as in any other steam plant configuration, the power density in a nuclear reactor core is typically four orders of magnitude higher than a fossil fueled plant and therefore it poses significant heat transfer challenges. Maximum power that can be obtained from a nuclear reactor is often limited by the

459

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

DOE Green Energy (OSTI)

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