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Computer simulation of explosive fracture of oil shale

Description: The steps in assembling the computational tools needed to simulate the explosive fracture of oil shale have been described. The resulting code, with its input data, was then used to simulate three explosive field experiments. The results of the calculations are in good agreement with what actually occurred in the field. Further detailed comparisons are in progress for these experiments and the others that have been conducted. As this is done, improvements will be made in the input data and in the code physics. The development of computer codes as tools to predict rock breakage makes a variety of interesting studies possible. The properties of the explosive can be changed to see how the extent of rubbling is affected. Studies of spacing and delays for decked charges are also possible. Finally, the codes can be applied in situations, such as confined-volume blasting, at the frontiers of blasting technology. These areas are vital to the effective utilization of our oil shale resources, especially with in situ techniques. Computer simulation will play a central role in the development of new technology for energy and mineral resource recovery.
Date: January 1, 1980
Creator: Adams, T.F.
Partner: UNT Libraries Government Documents Department

The Development of Mobile Melt-Dilute Technology for the Treatment of Former Soviet Union Research Reactor Fuel

Description: On-site application of the MMD process offers an economical method for converting weapons usable Former Soviet Union (FSU) High Enriched Uranium (HEU) research reactor fuel to a safe and secure Low Enriched Uranium (LEU) ingot. The objective of the MMD Project is to develop the mobile melt and dilute technology in preparation for active equipment deployment in the Newly Independent States (NIS) of the FSU.
Date: October 9, 2003
Creator: Adams, T.
Partner: UNT Libraries Government Documents Department

Application of the HWVP measurement error model and feed test algorithms to pilot scale feed testing

Description: The purpose of the feed preparation subsystem in the Hanford Waste Vitrification Plant (HWVP) is to provide, for control of the properties of the slurry that are sent to the melter. The slurry properties are adjusted so that two classes of constraints are satisfied. Processability constraints guarantee that the process conditions required by the melter can be obtained. For example, there are processability constraints associated with electrical conductivity and viscosity. Acceptability constraints guarantee that the processed glass can be safely stored in a repository. An example of an acceptability constraint is the durability of the product glass. The primary control focus for satisfying both processability and acceptability constraints is the composition of the slurry. The primary mechanism for adjusting the composition of the slurry is mixing the waste slurry with frit of known composition. Spent frit from canister decontamination is also recycled by adding it to the melter feed. A number of processes in addition to mixing are used to condition the waste slurry prior to melting, including evaporation and the addition of formic acid. These processes also have an effect on the feed composition.
Date: March 1, 1996
Creator: Adams, T.L.
Partner: UNT Libraries Government Documents Department

Properties of energetic materials: United States Department of Energy (DOE) Accelerated Strategic Computing Initiative (ASCI) strategic alliances

Description: The Accelerated Strategic Computing Initiative (ASCI) program is designed to provide the computational resources which are required to provide a simulation based approach to the Science Based Stockpile Stewardship (SBSS) program. The capability to predict the properties of energetic materials is one of the areas of interest to the US Department of Energy`s (DOE) ASCI program. This capability will support computational assessments of the safety and reliability of systems containing explosives and other energetic materials subjected to normal and abnormal environments. Several research elements related to energetic material properties are described in more detail below. They are: (A) calculation of decomposition rates, (B) molecular potential functions, (C) physical properties and transport coefficients, (D) molecular energization mechanisms, (E) fracture/failure of energetic material crystals, (F) grain-grain and grain- binder interactions, and (G) aging effects in energetic material. These elements have in common the need to develop computational methods that have a strong foundation in basic physical principles. They will generally have to be implemented to run efficiently on advanced parallel computing platforms to achieve sufficient accuracy.
Date: January 1, 1997
Creator: Adams, T.F.
Partner: UNT Libraries Government Documents Department

Parallel algorithm development

Description: Rapid changes in parallel computing technology are causing significant changes in the strategies being used for parallel algorithm development. One approach is simply to write computer code in a standard language like FORTRAN 77 or with the expectation that the compiler will produce executable code that will run in parallel. The alternatives are: (1) to build explicit message passing directly into the source code; or (2) to write source code without explicit reference to message passing or parallelism, but use a general communications library to provide efficient parallel execution. Application of these strategies is illustrated with examples of codes currently under development.
Date: June 1, 1996
Creator: Adams, T.F.
Partner: UNT Libraries Government Documents Department

Characterization of Corrosion Products from Static Cell Testing of Al-SNF Forms

Description: Aluminum-based spent nuclear fuel from foreign and domestic research reactors is being consolidated at the Savannah River Site (SRS) for ultimate disposal in the Monitored Geologic Repository. The melt-dilute treatment technology has been developed to consolidate fuel assemblies by a melting/casting process in which depleted uranium is added to reduce enrichment below 20 percent 235-U. The melt-dilute product is essentially a binary uranium-aluminum alloy to which neutron absorber materials may be readily added.
Date: September 17, 2002
Creator: Adams, T.
Partner: UNT Libraries Government Documents Department

Numerical simulation of fracture

Description: The Bedded Crack Model (BCM) is a constitutive model for brittle materials. It is based on effective modulus theory and makes use of a generalized Griffith criterion for crack growth. It is used in a solid dynamic computer code to simulate stress wave propagation and fracture in rock. A general description of the model is given and then the theoretical basis for it is presented. Some effects of finite cell size in numerical simulations are discussed. The use of the BCM is illustrated in simulations of explosive fracture of oil shale. There is generally good agreement between the calculations and data from field experiments.
Date: January 1, 1982
Creator: Margolin, L.G. & Adams, T.F.
Partner: UNT Libraries Government Documents Department

Simulation of rock fracture with the 3-D SHALE code

Description: The 3-D SHALE code simulates the propagation of stress waves and the occurrence of fracture in brittle solids. The physical models and numerical methods in this code are similar to those used in 2-D SHALE. We describe the 3-D code and present sample calculations for blasting in oil shale with a single isolated charge, an infinite array of charges, and an isolated pair of charges. These calculations illustrate the use of the code to simulate dynamic phenomena in complex geometric configurations. Some useful code improvements and possible applications are discussed. 8 references, 7 figures.
Date: January 1, 1985
Creator: Nichols, B.D. & Adams, T.F.
Partner: UNT Libraries Government Documents Department

Volatilization of Fission Products from Metallic Melts in the Melt-Dilute Treatment Technology Development for Al-Based DOE Spent Nuclear Fuels

Description: The melt-dilute treatment technology is being developed to facilitate the ultimate disposition of highly enriched Al-Base DOE spent nuclear fuels in a geologic repository such as that proposed for Yucca Mountain. Currently, approximately 28 MTHM is expected to be returned to the Savannah River Site from domestic and foreign research reactors. The melt-dilute treatment technology will melt the fuel assemblies to reduce their volume and alloys them with depleted uranium to isotopically dilute the 235U concentration. The resulting alloy is cast into a form for long term geologic repository storage. Benefits accrued from the melt-dilute process include the potential for significant volume reduction; reduced criticality potential, and proliferation concerns. A critical technology element in the development of the melt-dilute process is the development of offgas system requirements. The volatilization of radioactive species during the melting stage of the process primarily constitutes the offgas in this process. Several of the species present following irradiation of a fuel assembly have been shown to be volatile or semi-volatile under reactor core melt-down conditions. Some of the key species that have previously been studied are krypton, iodine, and cesium. All of these species have been shown to volatilize during melting experiments however, the degree to which they are released is highly dependent upon atmosphere, fuel burnup, temperature, and fuel composition. With this in mind an analytical and experimental program has been undertaken to assess the volatility and capture of species under the melt-dilute operating conditions.
Date: November 18, 1999
Creator: Adams, T.
Partner: UNT Libraries Government Documents Department

Automated microprocessor-controlled atomic absorption analysis of natural water for arsenic and selenium

Description: An automated, dual-channel atomic absorption spectrophotometer for the simultaneous determination of arsenic and selenium in natural water is now in operation. The instrument was constructed from commercially available optical components, spectral sources, and a sample changer. Automation was achieved by using an in-house-fabricated and programmed microprocessor. The instrument will analyze samples at a rate of 37 per hour, and a quantitative determination of arsenic and selenium to 0.2 ..mu..g/l (ppB) can be achieved. Arsenic can be determined with a precision of 19% at 1 ..mu..g/l and 6% at 10 ..mu..g/l, while selenium can be determined with a precision of 17% at 1 ..mu..g/l and 4% at 10 ..mu..g/l.
Date: August 1, 1978
Creator: Morrow, R.W.; Futrell, T.L. & Adams, T.T.
Partner: UNT Libraries Government Documents Department

Variable star research at Los Alamos

Description: Three major areas of variable star research at Los Alamos are carried out: (1) a study using improved Cepheid light curves in order to define more precisely the Hertzsprung sequence, in collaboration with John Castor and John Cox; (2) the suggestion by A. Cox that helium enrichment occurs in the stellar envelope, by a stellar wind, which may explain many of the mass anomalies, this work being with G. Michaud, D. King, R. Deupree, and S. Hodson; and (3) the study of Cepheid and RR Lyrae colors to compare directly to the observations. A brief discussion of the present status of each of these research programs will be given. 25 references.
Date: January 1, 1978
Creator: Davis, C.G.; Cox, A.N. & Adams, T.F.
Partner: UNT Libraries Government Documents Department

Permeability enhancement using explosive techniques

Description: In situ recovery methods for many of our hydrocarbon and mineral resources depend on the ability to create or enhance permeability in the resource bed to allow uniform and predictable flow. To meet this need, a new branch of geomechanics devoted to computer prediction of explosive rock breakage and permeability enhancement has developed. The computer is used to solve the nonlinear equations of compressible flow, with the explosive behavior and constitutive properties of the medium providing the initial/boundary conditions and material response. Once the resulting computational tool has been verified and calibrated with appropriate large-scale field tests, it can be used to develop and optimize commercially useful explosive techniques for in situ resource recovery.
Date: January 1, 1980
Creator: Adams, T.F.; Schmidt, S.C. & Carter, W.J.
Partner: UNT Libraries Government Documents Department

Instrumentation and diagnostic techniques used by Los Alamos National Laboratory in fragmentation experiments in oil shale

Description: Discussed are the instrumentation and diagnostic techniques used to evaluate the explosive fragmentation experiments in oil shale at the Colony and Anvil Points Mines in Colorado. These experiments were conducted to investigate some of the many parameters that control the fragmenting or rubblizing of oil shale in preparation for subsurface retorting. Framing and TV cameras were used to study the size and speed of the ejected shale fragments. Stress and accelerometer gauges provided quantitative data about the explosively induced stress field in the rock. The CORRTEX technique was used to determine the detonation velocity of the explosive and the induced fracture velocity in the oil shale. Postshot measurements included the crater dimensions and rubble size distribution. In addition preshot and postshot geological mapping was done to relate fractures and joints to crater size and shape.
Date: January 1, 1981
Creator: Edwards, C.L.; Adams, T.F. & Dick, R.D.
Partner: UNT Libraries Government Documents Department

Measurement of the neutron spectrum from the reaction of 30-MeV deuterons on a thick beryllium target

Description: Measurements were made of the neutron spectrum produced by bombarding a thick beryllium target with 30-MeV deuterons at the University of California, Davis cyclotron. This spectrum is of interest in studying the effect of neutrons on materials to be used in future fusion reactors. The spectrum was inferred from the activation of two sets of detector foils placed at 0/sup 0/ to the deuteron beam, one immediately behind the beryllium target block, and one 40 mm to the rear. A least-squares program was used to analyze the foil activation data to obtain the fluence in each of seven energy groups. The neutron spectrum (fluence/MeV) close to the target decreases continuously with energy in the range 5-32 MeV, while the spectrum 40 mm back has a peak at about 13 MeV. The contribution from neutrons of energies less than 10 MeV is much greater than that found in previous spectral measurements made at large distances from the target. This difference is attributed to the neutrons which are emitted at large angles from the deuteron beam. These observations show the importance of evaluating the neutron spectrum near the target if samples of materials are to be irradiated in this location. (auth)
Date: February 16, 1976
Creator: Nethaway, D. R.; Van Konynenburg, R. A. & Adams, T. M.
Partner: UNT Libraries Government Documents Department

Light curves for ''bump Cepheids'' computed with a dynamically zoned pulsation code

Description: The dynamically zoned pulsation code developed by Castor, Davis, and Davison has been used to recalculate the Goddard model and to calculate three other Cepheid models with the same period (9.8 days). This family of models shows how the bumps and other features of the light and velocity curves change as the mass is varied at constant period. This study, with a code that is capable of producing reliable light curves, shows again that the light and velocity curves for 9.8-day Cepheid models with standard homogeneous compositions do not show bumps like those that are observed unless the mass is significantly lower than the ''evolutionary mass.'' The light and velocity curves for the Goddard model presented here are similar to those computed independently by Fischel, Sparks, and Karp. They should be useful as standards for future investigators.
Date: January 1, 1978
Creator: Adams, T.F.; Castor, J.E. & Davis, C.G.
Partner: UNT Libraries Government Documents Department

Theoretical light and velocity curves for Cepheid variables. [Nonlinear models]

Description: New Research Initiatives Program W-318 was successfully completed with the calculation of a series of nonlinear Cepheid models with the new DYN code. The dynamical zoning feature of the DYN code makes it unique in that it allows reliable light curves, as well as velocity curves, to be calculated. The models are used to extend to light curves Christy's conclusion, based on velocity curves, that the observations of Cepheids cannot be matched unless the mass is significantly reduced (assuming a homogeneous composition). An examination of results also leads to the conclusion that observed light curves are considerably more complex than has previously been thought. The light and velocity curves we have calculated should be useful guides for interpreting the observations. 36 references.
Date: December 1, 1978
Creator: Adams, T.F.; Davis, C.G. & Keller, C.F.
Partner: UNT Libraries Government Documents Department

ALTERNATIVE MATERIALS TO PD MEMBRANES FOR HYDROGEN PURIFICATION

Description: Development of advanced hydrogen separation membranes in support of hydrogen production processes such as coal gasification and as front end gas purifiers for fuel cell based system is paramount to the successful implementation of a national hydrogen economy. Current generation metallic hydrogen separation membranes are based on Pd-alloys. Although the technology has proven successful, at issue is the high cost of palladium. Evaluation of non-noble metal based dense metallic separation membranes is currently receiving national and international attention. The focal point of the reported work was to evaluate two different classes of materials for potential replacement of conventional Pd-alloy purification/diffuser membranes. Crystalline V-Ni-Ti and Amorphous Fe- and Co-based metallic glass alloys have been evaluated using gaseous hydrogen permeation testing techniques.
Date: September 12, 2008
Creator: Korinko, P & Adams, T.
Partner: UNT Libraries Government Documents Department

Hydrogen Permeability of Mulitphase V-Ti-Ni Metallic Membranes

Description: Development of advanced hydrogen separation membranes in support of hydrogen production processes such as coal gasification and as front end gas purifiers for fuel cell based system is paramount to the successful implementation of a national hydrogen economy. Current generation metallic hydrogen separation membranes are based on Pd-alloys. Although the technology has proven successful, at issue is the high cost of palladium. Evaluation of non-noble metal based dense metallic separation membranes is currently receiving national and international attention. The focal point of the reported work was to evaluate a Group 5A-Ta, Nb, V-based alloy with respect to microstructural features and hydrogen permeability. Electrochemical hydrogen permeation testing of the V-Ti-Ni alloy is reported herein and compared to pure Pd measurements recorded as part of this same study. The V-Ti-Ni was demonstrated to have a steady state hydrogen permeation rate an order of magnitude higher than the pure Pd material in testing conducted at 22 C.
Date: October 18, 2005
Creator: Adams, T. M. & Mickalonis, J.
Partner: UNT Libraries Government Documents Department

Hydrogen Permeability of Mulitphase V-Ti-Ni Metallic Membranes

Description: Development of advanced hydrogen separation membranes in support of hydrogen production processes such as coal gasification and as front end gas purifiers for fuel cell based system is paramount to the successful implementation of a national hydrogen economy. Current generation metallic hydrogen separation membranes are based on Pd-alloys. Although the technology has proven successful, at issue is the high cost of palladium. Evaluation of non-noble metal based dense metallic separation membranes is currently receiving national and international attention. The focal point of the reported work was to evaluate a Group 5A-Ta, Nb, V-based alloy with respect to microstructural features and hydrogen permeability. Electrochemical hydrogen permeation testing of the V-Ti-Ni alloy is reported herein and compared to pure Pd measurements recorded as part of this same study. The V-Ti-Ni was demonstrated to have a steady state hydrogen permeation rate an order of magnitude higher than the pure Pd material in testing conducted at 22 C.
Date: October 18, 2005
Creator: Adams, T. M. & Mickalonis, J.
Partner: UNT Libraries Government Documents Department

Searches for new phenomena with lepton final states at the Tevatron

Description: Numerous searches for new phenomena have been carried out using data from proton-antiproton collisions at Fermilab's Tevatron. Final states with leptons give signatures which are relatively unique and generally have small backgrounds. We present many of the latest results from the CDF and D0 collaborations from 0.4-1.2 fb{sup -1} of data. Topics include supersymmetry, extra gauge bosons, Randall-Sundrum gravitons, excited electrons and neutral, long-lived particles.
Date: May 1, 2007
Creator: Adams, T. & U., /Florida State
Partner: UNT Libraries Government Documents Department

LASER ENGINEERED NET SHAPING FOR REPAIR AND HYDROGEN COMPATIBILITY

Description: A method to repair mismatched or damaged components using Laser Engineered Net Shaping{sup R} (LENS) technology to apply material was investigated for its feasibility for components exposed to hydrogen. The mechanical properties of LENS bulk materials were also tested for hydrogen compatibility. The LENS process was used to repair simulated and actual mismachined components. These sample components were hydrogen charged and burst tested in the as-received, as-damaged, and as-repaired conditions. The testing showed that there was no apparent additional deficiency associated with hydrogen charging compared to the repair technique. The repair techniques resulted in some components meeting the requirements while others did not. Additional procedure/process development is required prior to recommending production use of LENS.
Date: August 5, 2011
Creator: Korinko, P. & Adams, T.
Partner: UNT Libraries Government Documents Department