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Enhanced High Temperature Corrosion Resistance in Advanced Fossil Energy Systems by Nano-Passive Layer Formation

Description: Due to their excellent corrosion resistance, iron aluminum alloys are currently being considered for use as weld claddings in fossil fuel fired power plants. The susceptibility to hydrogen cracking of these alloys at higher aluminum concentrations has highlighted the need for research into the effect of chromium additions on the corrosion resistance of lower aluminum alloys. In the present work, three iron aluminum alloys were exposed to simulated coal combustion environments at 500 C and 700 C… more
Date: June 14, 2007
Creator: Marder, Arnold R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Quantitative Microanalysis with high Spatial Resolution: Application of FEG-DTEM XEDS Microanalysis to the Characterization of Complex Microstructures in Irradiated Low Alloy Steet

Description: To assist in the characterization of microstructural changes associated with irradiation damage in low alloy steels, the technique of quantitative x-ray mapping using a field emission gun scanning transmission electron microscope (FEG-STEM) equipped with an x-ray energy Dispersive spectrometer (XEDS) has been employed. Quantitative XEDS microanalyses of the matrix and grain boundaries of irradiated specimens have been compared with previous quantitative analyses obtained using 3D-Atom Probe Fie… more
Date: November 14, 2001
Creator: Williams, D.B., Watanabe, M. and Burke, M.G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Characterization of Intergranular Fission Gas Bubbles in U-MO Fuel.

Description: This report can be divided into two parts: the first part, which is composed of sections 1, 2, and 3, is devoted to report the analyses of fission gas bubbles; the second part, which is in section 4, is allocated to describe the mechanistic model development. Swelling data of irradiated U-Mo alloy typically show that the kinetics of fission gas bubbles is composed of two different rates: lower initially and higher later. The transition corresponds to a burnup of {approx}0 at% U-235 (LEU) or a f… more
Date: April 14, 2008
Creator: Kim, Y. S.; Hofman, G.; Rest, J.; Shevlyakov, G. V.; Division, Nuclear Engineering & RIAR, SSCR
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Mask inspection microscopy with 13.2 nm table-top laser illumination

Description: We report the demonstration of a reflection microscope that operates at 13.2-nm wavelength with a spatial resolution of 55 {+-} 3 nm. The microscope uses illumination from a table-top EUV laser to acquire aerial images of photolithography masks with a 20 second exposure time. The modulation transfer function of the optical system was characterized.
Date: October 14, 2008
Creator: Brizuela, Fernando; Wang, Yong; Brewer, Courtney A.; Pedaci, Francesco; Chao, Weilun; Anderson, Erik H. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Reactivity of Ozone with Solid Potassium Iodide Investigated by Atomic Force Microscopy

Description: The reaction of ozone with the (100) plane of solid potassium iodide (KI) was investigated using atomic force microscopy (AFM). The reaction forming potassium iodate (KIO{sub 3}) initiates at step edges prior to reacting on the flat terraces. Small domains of KIO{sub 3}, initially 3.8 {angstrom} in height are formed on the top of step edges. Following reaction at the step edge, domains of KIO{sub 3} are formed across the terraces. With prolonged exposure to ozone, KIO{sub 3} domains nucleate fu… more
Date: April 14, 2008
Creator: Mulleregan, Alice; Brown, Matthew A.; Ashby, Paul D.; Ogletree, D. Frank; Salmeron, Miquel & Hemminger, John C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Imaging of InGaN inhomogeneities using visible aperturelessnear-field scanning optical microscope

Description: The optical properties of epitaxially grown islands of InGaN are investigated with nanometer-scale spatial resolution using visible apertureless near-field scanning optical microscopy. Scattered light from the tip-sample system is modulated by cantilever oscillations and detected at the third harmonic of the oscillation frequency to distinguish the near-field signal from unwanted scattered background light. Scattered near-field measurements indicate that the as-grown InGaN islanded film may exh… more
Date: June 14, 2007
Creator: Stebounova, Larissa V.; Romanyuk, Yaroslav E.; Chen, Dongxue & Leone, Stephen R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Scaling Behavior of Barkhausen Avalanches along the Hysteresis loop in Nucleation-Mediated Magnetization Reversal Process

Description: We report the scaling behavior of Barkhausen avalanches for every small field step along the hysteresis loop in CoCrPt alloy film having perpendicular magnetic anisotropy. Individual Barkhausen avalanche is directly observed utilizing a high-resolution soft X-ray microscopy that provides real space images with a spatial resolution of 15 nm. Barkhausen avalanches are found to exhibit power-law scaling behavior at all field steps along the hysteresis loop, despite their different patterns for eac… more
Date: October 14, 2008
Creator: Im, Mi-Young; Fischer, Peter; Kim, D.-H. & Shin, S.-C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Growth and structure of water on SiO2 films on Si investigated byKelvin probe microscopy and in situ X-ray Spectroscopies

Description: The growth of water on thin SiO{sub 2} films on Si wafers at vapor pressures between 1.5 and 4 torr and temperatures between -10 and 21 C has been studied in situ using Kelvin Probe Microscopy and X-ray photoemission and absorption spectroscopies. From 0 to 75% relative humidity (RH) water adsorbs forming a uniform film 4-5 layers thick. The surface potential increases in that RH range by about 400 mV and remains constant upon further increase of the RH. Above 75% RH the water film grows rapidl… more
Date: June 14, 2007
Creator: Verdaguer, A.; Weis, C.; Oncins, G.; Ketteler, G.; Bluhm, H. & Salmeron, M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Waveguide Fabrication in Fused Silica Using Tightly Focused Femtosecond Laser Pulses

Description: Refractive index changes have been induced inside bulk fused silica by using femtosecond (fs) laser pulses tightly focused inside the material. Waveguides have been fabricated inside the glass by scanning the glass with respect to the focal point of the laser beam. The refractive index change is estimated to be {approx} 10{sup -4}. Other more complex three-dimensional structures have also been fabricated (curved waveguides, splitters, and interferometers). We also report on fluorescence spectro… more
Date: December 14, 2001
Creator: Chan, J W; Huser, T; Risbud, S H & Krol, D M
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Cryoforming evaluation using high-purity nickel

Description: The cryogenic forming process was evaluated using nickel 270 to see if it had significant advantages over room-temperature (RT) forming. Typically, the procedure involved fast-strain-rate forming a set of nickel samples at cryogenic temperatures and another set at RT. Both sets were measured at RT for failure strength and their strength-preparation elongation curves compared at equal strains. Two more sets were formed, this time at slow strain rates (one at cryogenic temperatures, the other at … more
Date: September 14, 1976
Creator: Lord, D. E. & Meisner, L. F.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

IMPACT OF CURING TEMPERATURE ON THE SATURATED LIQUID PERMEABILITY OF SALTSTONE

Description: This report focuses on the impact of curing temperature on the performance properties of simulated Saltstone mixes. The key performance property of interest is saturated liquid permeability (measured as hydraulic conductivity), an input to the Performance Assessment (PA) modeling for the Saltstone Disposal Facility (SDF). Therefore, the current study was performed to measure the dependence of saturated hydraulic conductivity on curing temperature of Saltstone mixes, to correlate these results w… more
Date: February 14, 2011
Creator: Williams, F. & Harbour, J.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Statistical Behavior of Formation Process of Magnetic Vortex State in Ni80Fe20 Nanodisks

Description: Magnetic vortices in magnetic nanodots, which are characterized by an in-plane (chirality) and an out-of-plane (polarity) magnetizations, have been intensively attracted because of their high potential for technological application to data storage and memory scheme as well as their scientific interest for an understanding of fundamental physics in magnetic nanostructures. Complete understanding of the formation process of vortex state in magnetic vortex systems is very significant issue to achi… more
Date: January 14, 2011
Creator: Im, Mi-Young; Fischer, Peter; Keisuke, Yamada & Kasai, Shinya
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Focused ion beam patterned Fe thin films A study by selective area Stokes polarimetry and soft x-Ray microscopy

Description: We demonstrate the potential to modify the magnetic behavior and structural properties of ferromagnetic thin films using focused ion beam 'direct-write' lithography. Patterns inspired by the split-ring resonators often used as components in meta-materials were defined upon 15 nm Fe films using a 30 keV Ga{sup +} focused ion beam at a dose of 2 x 10{sup 16} ions cm{sup -2}. Structural, chemical and magnetic changes to the Fe were studied using transmission soft X-ray microscopy at the ALS, Berke… more
Date: November 14, 2010
Creator: Cook, P. J.; Shen, T. H.; Grundy, P. J.; Im, M.-Y.; Fischer, P.; Morton, S. A. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Quality engineering and control semiannual progress report November and December 1976 and January--April 1977

Description: Research and development activities are reported on absorption spectroscopy, calorimetry, electrolysis, emission spectroscopy, fluorimetry gas chromatography, infrared spectroscopy, liquid chromatography, liquid scintillation counting, mass spectroscopy, microscopy, radiometric analysis, and thermal analysis. A group of miscellaneous projects are also described. (JRD)
Date: July 14, 1977
Creator: Carpenter, R. L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Halogenated high {Tc} superconductors and method of preparation

Description: Disclosed is a method for producing a superconductor of the R-Ba-Cu-O system which comprises of selecting an insulating material of the formula RBa{sub x}Cu{sub y}O{sub z} where R is selected from the group consisting of Y, La, Pr, Nd, Sm, Eu, Gd, Ho, Er, Tm, and Lu, and where x ranges from about 1.7 to about 2.3, y ranges from about 2.7 to about 3.3 and z ranges from about 5.0 to about 6.99, and halogenating said material with a halogen selected from the group consisting of chlorine, bromine, … more
Date: November 14, 1990
Creator: Radousky, H. B.; Glass, R. S. & Fluss, M. J.
Item Type: Refine your search to only Patent
Partner: UNT Libraries Government Documents Department
open access

Graphene Growth by Metal Etching on Ru (0001)

Description: Low-energy electron microscopy (LEEM) reveals a new mode of graphene growth on Ru(0001) in which Ru atoms from a step edge are injected under a growing graphene sheet. The injected atoms can form under-graphene islands, or incorporate into the topmost Ru layer, thereby increasing its density and forming dislocation networks. Density functional calculations imply that Ru islands nucleated between the graphene layer and the substrate are energetically stable; scanning tunneling microscopy (STM) r… more
Date: September 14, 2009
Creator: Loginova, Elena; Maier, Sabine; Stass, Ingeborg; Bartelt, Norman; Feibelman, Peter; Salmeron, Miquel et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Graphical Methods for Quantifying Macromolecules through Bright Field Imaging

Description: Bright ?eld imaging of biological samples stained with antibodies and/or special stains provides a rapid protocol for visualizing various macromolecules. However, this method of sample staining and imaging is rarely employed for direct quantitative analysis due to variations in sample fixations, ambiguities introduced by color composition, and the limited dynamic range of imaging instruments. We demonstrate that, through the decomposition of color signals, staining can be scored on a cell-by-ce… more
Date: August 14, 2008
Creator: Chang, Hang; DeFilippis, Rosa Anna; Tlsty, Thea D. & Parvin, Bahram
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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High-Resolution Spore Coat Architecture and Assembly of Bacillus Spores

Description: Elucidating the molecular architecture of bacterial and cellular surfaces and its structural dynamics is essential to understanding mechanisms of pathogenesis, immune response, physicochemical interactions, environmental resistance, and provide the means for identifying spore formulation and processing attributes. I will discuss the application of in vitro atomic force microscopy (AFM) for studies of high-resolution coat architecture and assembly of several Bacillus spore species. We have demon… more
Date: March 14, 2011
Creator: Malkin, A J; Elhadj, S & Plomp, M
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Directed assembly of discrete gold nanoparticle groupings usingbranched DNA scaffolds

Description: The concept of self-assembled dendrimers is explored for the creation of discrete nanoparticle assemblies. Hybridization of branched DNA trimers and nanoparticle-DNA conjugates results in the synthesis of nanoparticle trimer and tetramer complexes. Multiple tetramer architectures are investigated, utilizing Au-DNA conjugates with varying secondary structural motifs. Hybridization products are analyzed by gel electrophoresis, and discrete bands are observed corresponding to structures with incre… more
Date: September 14, 2004
Creator: Claridge, Shelley A.; Goh, Sarah L.; Frechet, Jean M.J.; Williams, Shara C.; Micheel, Christine M. & Alivisatos, A. Paul
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Atomic Scale coexistence of Periodic and quasiperiodic order in a2-fold A1-Ni-Co decagonal quasicrystal surface

Description: Decagonal quasicrystals are made of pairs of atomic planes with pentagonal symmetry periodically stacked along a 10-fold axis. We have investigated the atomic structure of the 2-fold surface of a decagonal Al-Ni-Co quasicrystal using scanning tunneling microscopy (STM). The surface consists of terraces separated by steps of heights 1.9, 4.7, 7.8, and 12.6{angstrom} containing rows of atoms parallel to the 10-fold direction with an internal periodicity of 4{angstrom}. The rows are arranged aperi… more
Date: November 14, 2005
Creator: Park, Jeong Young; Ogletree, D. F.; Salmeron, M.; Ribeiro, R. A.; Canfield, P. C.; Jenks, C. J. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Reversible wetting of NaCl nanoparticles at relative humidities below deliquescence observed by environmental non-contact AFM

Description: The behavior of NaCl nanoparticles as a function of relative humidity (RH) was characterized by depositing particles on a prepared hydrophobic surface and measuring their height via non-contact environmental atomic force microscopy (AFM). Non-contact AFM allows greater sensitivity to changes in the size of particles than does contact AFM or scanning electron microscopy, and greater sensitivity to changes in shape than do mass-based techniques. Crystalline cubic NaCl nanoparticles with sides of … more
Date: December 14, 2009
Creator: Bruzewicz, D.A.; Lewis, E.; Ocko, B. M.; McGraw, R. L. & Schwartz, S. E.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Historical background: Why is it important to improve automated particle selection methods?

Description: A current trend in single-particle electron microscopy is to compute three-dimensional reconstructions with ever-increasing numbers of particles in the data sets. Since manual--or even semi-automated--selection of particles represents a major bottleneck when the data set exceeds several thousand particles, there is growing interest in developing automatic methods for selecting images of individual particles. Except in special cases, however, it has proven difficult to achieve the degree of effi… more
Date: August 14, 2003
Creator: Glaeser, Robert M.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Seeing atoms only 0.78A apart

Description: The one-Angstrom microscope (OAM) project at the USDOE's National Center for Electron Microscopy has extended the limits of high-resolution transmission electron microscopy to sub-Angstrom levels. The OAM combines image-processing software with a modified 300keV electron microscope equipped with a highly-coherent field-emission electron gun. We have found that a reduction in the OAM's electron-gun extraction voltage allows us to ''see'' silicon atoms separated by only 0.78A.
Date: March 14, 2001
Creator: O'Keefe, M. A. & Nelson, E. C.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Reduction of Micro-Cracks in Large Diameter InxGa1-XSb Bulk Crystals

Description: The ternary alloy, In{sub x}Ga{sub 1-x}Sb, is a compound semiconductor of tunable bandgap in the range of 0.18-0.72 eV, making it useful for infrared range optoelectronic devices. Utilizing a unique system based upon vertical Bridgman technique, large diameter (50 millimeter) In{sub x}Ga{sub 1-x}Sb polycrystals of composition ranging in x from 0.015 to 0.988 were grown. Methods of mixing the melt during solidification, including the accelerated crucible rotation technique (ACRT), have been used… more
Date: April 14, 2003
Creator: Vogel, Juliet & Dutta, Partha S.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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