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Corrosion and Creep of Candidate Alloys in High Temperature Helium and Steam Environments for the NGNP

Description: This project aims to understand the processes by which candidate materials degrade in He and supercritical water/steam environments characteristic of the current NGNP design. We will focus on understanding the roles of temperature, and carbon and oxygen potential in the 750-850 degree C range on both uniform oxidation and selective internal oxidation along grain boundaries in alloys 617 and 800H in supercritical water in the temperature range 500-600 degree C; and examining the application of s… more
Date: June 21, 2013
Creator: Was, Gary & Jones, J. W.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Surface structure of protonated R-plane-sapphire (1-102) studied by sum frequency vibrational spectroscopy

Description: Sum frequency vibrational spectroscopy was used to study the protonated R-plane (1{bar 1}02 ) sapphire surface. The OH stretch vibrational spectra show that the surface is terminated with three hydroxyl moieties, two from AlOH{sub 2} and one from Al{sub 2}OH functional groups. The observed polarization dependence allows determination of the orientations of the three OH species. The results suggest that the protonated sapphire (1{bar 1}02 ) surface differs from an ideal stoichimetric termination… more
Date: April 1, 2011
Creator: Sung, J.; Zhang, L.; Tian, C.; Waychunas, G. A. & Shen, Y. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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A New Technique for Observing the Amorphous to Crystalline Transformation in Thin Surface Layers on Silicon Wafers

Description: Thin amorphous ({alpha}) films of silicon created by ion-implantation have been studied in-situ while undergoing the amorphous to crystalline transformation in the electron microscope. The specimens were prepared in such a manner that the amorphous/crystalline interface was viewed edge-on and its advance during annealing was easily observed over distances of several microns. Growth rates and activation energies were measured. The active role that defects play during the regrowth process was als… more
Date: February 1, 1980
Creator: Drosd, B. & Washburn, J.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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UV laser ablation of parylene films from gold substrates

Description: Parylene films, coating gold substrates, were removed by laser ablation using 248 nm light from an excimer laser. Each sample was processed by a different number of pulses in one of three different environments: air at atmospheric pressure, nitrogen at atmospheric pressure, and vacuum. The laser-induced craters were analyzed by optical microscopy and x-ray photoelectron spectroscopy. Multi-pulse ablation thresholds of gold and parylene were estimated.
Date: November 19, 2009
Creator: Musaev, O. R.; Scott, P.; Wrobel, J. M. & Kruger, M. B.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Surfaces of Intermetallics: Quasicrystals and Beyond

Description: The goal of this work is to characterize surfaces of intermetallics, including quasicrystals. In this work, surface characterization is primarily focused on composition and structure using X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM) performed under ultrahigh vacuum (UHV) conditions.
Date: October 26, 2012
Creator: Yuen, Chad
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Advanced Combustion

Description: Topics covered in this presentation include: the continued importance of coal; related materials challenges; combining oxy-combustion & A-USC steam; and casting large superalloy turbine components.
Date: March 5, 2013
Creator: Holcomb, Gordon R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Density functional theory studies on theelectronic, structural, phonon dynamicaland thermo-stability properties of bicarbonates MHCO3, M D Li, Na, K

Description: The structural, electronic, phonon dispersion and thermodynamic properties of MHCO3 (M D Li, Na, K) solids were investigated using density functional theory. The calculated bulk properties for both their ambient and the high-pressure phases are in good agreement with available experimental measurements. Solid phase LiHCO3 has not yet been observed experimentally. We have predicted several possible crystal structures for LiHCO3 using crystallographic database searching and prototype electrostati… more
Date: July 1, 2012
Creator: Duan, Yuhua; Zhang, Bo; Sorescu, Dan C.; Johnson, Karl; Majzoub, Eric H & Luebke, David R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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X-ray imaging of vortex cores in confined magnetic structures

Description: Cores of magnetic vortices in micron-sized NiFe disk structures, with thicknesses between 150 and 50 nm, were imaged and analysed by high resolution magnetic soft X-ray microscopy. A decrease of the vortex core radius was observed, from #24; ~38 to 18 nm with decreasing disk thickness. By comparing with full 3D micromagnetic simulations showing the well-known barrel structure, we obtained excellent agreement taking into account instrumental broadening and a small perpendicular anisotropy. The p… more
Date: February 11, 2011
Creator: Fischer, P.; Im, M.-Y.; Kasai, S.; Yamada, K.; Ono, T. & Thiaville, A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Statics and Dynamics of Dimensionally and Spatially Constrained Oxides. Summary Progress Report Submitted to Department of Energy Basic Energy Science Division. Division of Materials Science & Engineering.

Description: Work is reported on nanopatterning of ceramic oxides; microstructure tailoring, control and versatility of nanopatterned oxides; and characterization and localized properties of nanopatterned oxides.
Date: July 31, 2010
Creator: Dravid, Vinayak P.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Erosion Mechanism in Ductile Metals

Description: The removal of material from the surface of a ductile metal by small impacting particles is a design concern to the builders of synthetic fuels plants that utilize pulverized coal to produce gaseous forms of fuel. A series of room temperature experiments was conducted to determine the mechanism of material removal when an erosive particle stream impacts on a ductile metal surface. 1100-0 and 7075-T6 aluminum were used for the target and 600 {micro}m SiC particles moving at a velocity of 100 fps… more
Date: June 1, 1980
Creator: Bellman, Robert, Jr. & Levy, Alan
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Quantitative Studies of Thermal Shock in Ceramics Based on a Novel Test Technique

Description: A thermal shock test has been designed which permits the thermal fracture resistance and the mechanical strength of brittle materials to be quantitatively correlated. Thermal shock·results for two materials, Al{sub 2}O{sub 3} and SiC, have been accurately predicted from biaxial strength measurements and a transient thermal stress analysis (performed using a finite element method). General implications for the prediction of thermal shock resistance, with special reference to ceramic components, … more
Date: May 1, 1981
Creator: Faber, K. T.; Huang, M. D. & Evans, A. G.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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CORROSION ISSUES ASSOCIATED WITH AUSTENITIC STAINLESS STEEL COMPONENTS USED IN NUCLEAR MATERIALS EXTRACTION AND SEPARATION PROCESSES

Description: This paper illustrated the magnitude of the systems, structures and components used at the Savannah River Site for nuclear materials extraction and separation processes. Corrosion issues, including stress corrosion cracking, pitting, crevice corrosion and other corrosion induced degradation processes are discussed and corrosion mitigation strategies such as a chloride exclusion program and corrosion release testing are also discussed.
Date: December 17, 2012
Creator: Mickalonis, J.; Louthan, M. & Sindelar, R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Study of Hydrophobic and Ionizable Hydrophilic Copolymers at Polymer/Solid and Polymer/Liquid Interfaces

Description: Joint experimental-computational efforts were set to characterize the interfacial effects on the structure and dynamics of polymers consisting of highly rigid hydrophilic-ionizable and hydrophobic sub-units within one polymeric chain casted into thin films of several molecular dimensions. Focusing on the ultra thin film region we separate out the interfacial effects from bulk characteristics. Specifically, the study sought to: identify the parameters that control the formation of a stable polym… more
Date: November 1, 2011
Creator: Perahia, Dvora
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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A PRELIMINARY SURVEY OF SOME FLUORIDE COMPOUNDS - II

Description: These two parts were issued separately, but are cataloged as a unit. The two compounds Na/sub 4/U/sub 3/F/sub 17/ and Na/sub 3/Th/sub 2/F/sub 11/ were found to have a face-centered cubic structure. From parameter dimensions and intensity values these two compounds appear to be isomorphous. Na/sub 5/U/sub 3/F/sub 17/ has an identical cell size with alpha -Na/sub 2//UF/sub 6/. A group of three compounds (Rb/sub 2/ThF/sub Rb/sub 2/ZrF/sub 6/, and CsZrF/sub 6/) were reliably identified as being uni… more
Date: May 14, 1958
Creator: Harris, L.A.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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RELEASE OF ELASTIC STRAIN ENERGY AS ACOUSTIC EMISSION DURING THE REVERSE THERMOELASTIC PHASE TRANSFORMATION IN Au-47.5 at.percent Cd ALLOY

Description: The objective of this paper is to present experimental evidence concerning the acoustic energy evolved during the heating and cooling phase changes in Au-47.5 at.% Cd polycrystals. The results are examined from the point of view of the stored elastic strain energy during the martensite formation, and the frictional work that is dissipated by the movement of martensite interfaces in either direction, upon heating and cooling.
Date: May 1, 1980
Creator: Baram, J.; Avissar, J.; Gefen, Y. & Rosen, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Tabulation, bibliography, and structure of binary intermetallic compounds. III. Compounds of copper, silver and gold

Description: A review is given of the various transverse thermomagnetic and galvanomagnetic effects. The coefficicnts and relations between coefficients are listed for both metals and semiconductors. A quantitative annlysis is given of the error in Hall effcct measurements owing to non-isothermal conditions. (auth)
Date: September 9, 1957
Creator: Klepfer, H. H. & Shoemaker, H. E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Characterization of Optical Fiber Strength Under Applied Tensile Stress and Bending Stress

Description: Various types of tensile testing and bend radius tests were conducted on silica core/silica cladding optical fiber of different diameters with different protective buffer coatings, fabricated by different fiber manufacturers. The tensile tests were conducted to determine not only the average fiber strengths at failure, but also the distribution in fracture strengths, as well as the influence of buffer coating on fracture strength. The times-to-failure of fiber subjected to constant applied bend… more
Date: August 1, 2011
Creator: Klingsporn, P.E.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Preparation of Refractories from Uranium Dioxide for Melting Uranium

Description: Attention is now being drawn to the refractory properties of the pure dioxide of uranium, which make it suitable for special applications, such as the melting of pure uranium. Properties of uranium dioxide are described as they relate to fabrication. Forming of UO{sub 2} refractories by pressing and slip casting is discussed, as well as the firing of urania refractories and the properties of fired ware. Health hazards pertaining to UO{sub 2} are briefly described.
Date: April 29, 1952
Creator: R.E. Corwin, G.B. Eyerly
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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