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Evaluation of Irradiation Embrittlement of A508 Gr 4N and Comparison to Other Low-Alloy Steels

Description: A508 Gr 4N has improved fracture toughness because of the addition of 3% nickel, compared to typical low alloy steels which have less than 1% nickel. However, there is an expectation in much of the recent literature, based mostly on low-alloy steels with nickel below 1%, that irradiation embrittlement will increase with increasing nickel (Ni) content. In contrast, the raw irradiation test data show that ASTM A508 Grade 4N containing up to 3.7% nickel, 0.1% Cu and 0.01% P does not show enhanced … more
Date: June 17, 2002
Creator: G.L. Wire, W. J. Beggs and T.R. Leax
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Development of a Waste Treatment Process to Deactivate Reactive Uranium Metal and Produce a Stable Waste Form

Description: This paper highlights the results of initial investigations conducted to support the development of an integrated treatment process to convert pyrophoric metallic uranium wastes to a non-pyrophoric waste that is acceptable for land disposal. Several dissolution systems were evaluated to determine their suitability to dissolve uranium metal and that yield a final waste form containing uranium specie(s) amenable to precipitation, stabilization, adsorption, or ion exchange. During initial studies,… more
Date: January 17, 2002
Creator: Gates-Anderson, D D; Laue, C A & Fitch, T E
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Molecular Dynamics Simulations of Coulomb Explosion

Description: A swift ion creates a track of electronic excitations in the target material. A net repulsion inside the track can cause a ''Coulomb Explosion'', which can lead to damage and sputtering of the material. Here we report results from molecular-dynamics (MD) simulations of Coulomb explosion for a cylindrical track as a function of charge density and neutralization/quenching time, {tau}. Screening by the free electrons is accounted for using a screened Coulomb potential for the interaction among cha… more
Date: May 17, 2002
Creator: Bringa, E M
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Abrasive wear behavior of heat-treated ABC-silicon carbide

Description: Hot-pressed silicon carbide, containing aluminum, boron, and carbon additives (ABC-SiC), was subjected to three-body and two-body wear testing using diamond abrasives over a range of sizes. In general, the wear resistance of ABC-SiC, with suitable heat treatment, was superior to that of commercial SiC.
Date: June 17, 2002
Creator: Zhang, Xiao Feng; Lee, Gun Y.; Chen, Da; Ritchie, Robert O. & De Jonghe, Lutgard C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Grain boundary structure and solute segregation in titanium-doped sapphire bicrystals

Description: Solute segregation to ceramic grain boundaries governs material processing and microstructure evolution, and can strongly influence material properties critical to engineering performance. Understanding the evolution and implications of grain boundary chemistry is a vital component in the greater effort to engineer ceramics with controlled microstructures. This study examines solute segregation to engineered grain boundaries in titanium-doped sapphire (Al2O3) bicrystals, and explores relationsh… more
Date: May 17, 2002
Creator: Taylor, Seth T.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Fission Multiplicity Detection With Temporal Gamma-Neutron Discrimination From Higher Order Time Correlation Statistics

Description: The subject of this thesis is the nondestructive assay (NDA) of nuclear materials. NDA is made possible by the fact that fissile and fertile transuranic isotopes emit characteristic radiations. Fission Multiplicity Detection (FMD) is the name of the standard technique used in NDA of nuclear materials in the 1960s and 1970s. It was characterized by the use of fast plastic scintillating detectors. These systems were used in both active and passive mode. These FMD systems were eventually replaced … more
Date: January 17, 2002
Creator: Oberer, R.B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Practical superconductor development for electrical applications - quarterly report for the period ending June 30, 2002.

Description: This is a multiyear experimental research program that focuses on improving relevant material properties of high-T{sub c} superconductors (HTSs) and developing fabrication methods that can be transferred to industry for production of commercial conductors. The development of teaming relationships through agreements with industrial partners is a key element of the Argonne National Laboratory (ANL) program. The technical highlights from this quarter are that the capabilities and performance of a … more
Date: September 17, 2002
Creator: Dorris, S. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

The effect of low dose rate irradiation on the tensile properties and microstructure of austenitic stainless steel.

Description: To assess the effects of long-term, low-dose-rate neutron exposure on mechanical strength and ductility, tensile properties were measured on 12% and 20% cold-worked Type 316 stainless steel. Samples were prepared from reactor core components retrieved from the EBR-II reactor following final shutdown. Sample locations were chosen to cover a dose range of 1-56 dpa at temperatures from 371-440 C and dose rates from 0.5-5.8 x10{sup -7} dpa/s. These dose rates are approximately an order of magnitude… more
Date: September 17, 2002
Creator: Allen, T. R.; Tsai, H.; Cole, J. I.; Yoshitake, T.; Akasaka, N.; Donomae, T. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Effect of the location of Mn sites in ferromagnetic GaMnAs on its Curie temperature

Description: We report a strong correlation between the location of Mn sites in ferromagnetic Ga{sub 1-x}Mn{sub x}As measured by channeling Rutherford backscattering and by particle induced x-ray emission experiments and its Curie temperature. The concentrations of free holes determined by electrochemical capacitance-voltage profiling and of uncompensated Mn{sup ++} spins determined from SQUID magnetization measurements are found to depend on the concentration of unstable defects involving highly mobile Mn … more
Date: January 17, 2002
Creator: Yu, K.M.; Walukiewicz, W.; Wojtowicz, T.; Kuryliszyn, I.; Liu, X.; Sasaki, Y. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Vortex pinning in Nb films patterned with nano-scale hole-arrays.

Description: Nb films containing extended arrays of holes with 45-nm diameter and 100-nm spacing have been fabricated using anodized aluminum oxide (AAO) as substrate. Pronounced matching effects in the magnetization are seen in fields up to 9 kOe. Flux pinning in the patterned samples is enhanced by two orders of magnitude as compared to unpatterned reference samples in applied fields exceeding 5 kOe. The matching effects are a dominant contribution to vortex pinning at temperatures as low as 4.2 K due to … more
Date: September 17, 2002
Creator: Welp, U.; Xiao, Z. L.; Jiang, J. S.; Vlasko-Vlasov, V. K.; Bader, S. D.; Crabtree, G. W. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Superconducting phase diagram of single crystal MgB{sub 2}.

Description: Using magnetization, transport and single-crystal specific heat measurements we have determined the superconducting phase diagram of MgB{sub 2}. A zero-temperature in-pane coherence length of 9.4 nm is found. The superconducting anisotropy changes monotonously from a value around 2 near T{sub c} to above 4.5 near 22 K. We present strong evidence for a surface superconducting state for H{parallel}c which might account for the wide spread in reported values of the superconducting anisotropy.
Date: September 17, 2002
Creator: Welp, U.; Rydh, A.; Karapetrov, G.; Kwok, W. K.; Crabtree, G. W.; Marcenat, C. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Durability-Based Design Criteria for a Quasi-Isotropic Carbon-Fiber Automotive Composite

Description: This report provides recommended durability-based design properties and criteria for a quasi-isotropic carbon-fiber composite for possible automotive structural applications. The composite, which was made by a rapid molding process suitable for high-volume automotive applications, consisted of continuous Thornel T300 fibers (6K tow) in a Baydur 420 IMR urethane matrix. The reinforcement was in the form of four {+-}45{sup o} stitch-bonded mats in the following layup: [0/90{sup o}/{+-}45{sup o}]{… more
Date: April 17, 2002
Creator: Corum, J.M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Wakefield acceleration in structures.

Description: Wakefield acceleration in dielectric loaded structures is discussed in this paper. We present a description of the dielectric wakefield accelerator concept, comparing some features of the collinear and the two beam accelerator configurations. The Argonne Wakefield Accelerator Facility (AWA) is discussed in detail, including major upgrades that are presently taking place. The basic features and capabilities of the facility are presented, and the dielectric wakefield acceleration results are brie… more
Date: September 17, 2002
Creator: Conde, M. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Modeling of Material Removal by Solid State Heat Capacity Lasers

Description: Pulsed lasers offer the capability of rapid material removal. Here we present simulations of steel coupon tests by two solid state heat capacity lasers built at LLNL. Operating at 1.05 pm, these deliver pulse energies of about 80 J at 10 Hz, and about 500 J at 20 Hz. Each is flashlamp-pumped. The first laser was tested at LLNL, while the second laser has been delivered to HELSTF, White Sands Missile Range. Liquid ejection appears to be an important removal mechanism. We have modeled these exper… more
Date: April 17, 2002
Creator: Boley, C D & Rubenchik, A M
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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