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Oxygen electrodes for energy conversion and storage. Annual report, 1 October 1977-30 September 1978

Description: Research on the development of high performance, long life O/sub 2/ cathodes for both alkaline and acid electrolytes for a spectrum of applications including industrial electrolysis, fuel cells, and metal-air batteries is described. Oxygen electrocatalysts studied include platinum, silver, underpotential deposited layers and alloy metal layers on noble metal substrates, intercalated graphite, transition metal macrocyclic complexes, and transition metal oxides. Research on gas fed electrodes is … more
Date: January 15, 1980
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Defect states in plasma-deposited a-Si:H. Final report, February 1979-January 1980

Description: Studies of defects in plasma-deposited, hydrogenated amorphous silicon (a-Si:H), covering the period February 1979-January 1980 are described. Substantial progress has been made in understanding defect structures, their electronic properties and the influence of doping. The two most significant results are surprising, in one case for simplicity where complexity was expected, and in the other for complexity where simplicity had been presumed. In the first study we have clarified the nature of th… more
Date: February 15, 1980
Creator: Knights, J C
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Comparison of LiMnPO4 made by Combustion and Hydrothermal Syntheses

Description: Among the olivine-structured metal phosphate family, LiMnPO{sub 4} exhibits a high discharge potential (4V), which is still compatible with common electrolytes, making it interesting for use in the next generation of Li ion batteries. The extremely low electronic conductivity of this material severely limits its electrochemical performance, however. One strategy to overcome this limitation is to make LiMnPO{sub 4} nanoparticulate to decrease the diffusion distance. Another is to add a carbon or… more
Date: May 15, 2008
Creator: Chen, Jiajun; Doeff, Marca M. & Wang, Ruigang
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Spatial resolution limits for synchrotron-based infrared spectromicroscopy

Description: Detailed spatial resolution tests were performed on beamline 1.4.4 at the Advanced Light Source synchrotron facility in Berkeley, CA. The high-brightness synchrotron source is coupled at this beamline to a Thermo-Electron Continumum XL infrared microscope. Two types of resolution tests in both the mid-IR (using a KBr beamsplitter and an MCT-A* detector) and in the near-IR (using a CaF2 beamsplitter and an InGaAS detector) were performed and compared to a simple diffraction-limited spot size mod… more
Date: October 15, 2007
Creator: Levenson, Erika; Lerch, Philippe & Martin, Michael C.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Organic carbon distribution, speciation, and elementalcorrelations within soil microaggregates: applications of STXM and NEXAFSspectroscopy

Description: Soils contain the largest inventory of organic carbon on the Earth's surface. Therefore, it is important to understand how soil organic carbon (SOC) is distributed in soils. This study directly measured SOC distributions within soil microaggregates and its associations with major soil elements from three soil groups (Phaeozem, Cambisol, and Ultisol), using scanning transmission X-ray microscopy (STXM) and near-edge X-ray absorption fine structure (NEXAFS) spectroscopy at a spatial resolution of… more
Date: March 15, 2007
Creator: Wan, Jiamin; Tyliszczak, Tolek & Tokunaga, Tetsu K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Spectral induced polarization and electrodic potential monitoring of microbially mediated iron sulfide transformations

Description: Stimulated sulfate-reduction is a bioremediation technique utilized for the sequestration of heavy metals in the subsurface.We performed laboratory column experiments to investigate the geoelectrical response of iron sulfide transformations by Desulfo vibriovulgaris. Two geoelectrical methods, (1) spectral induced polarization (SIP), and (2) electrodic potential measurements, were investigated. Aqueous geochemistry (sulfate, lactate, sulfide, and acetate), observations of precipitates (identifi… more
Date: February 15, 2008
Creator: Hubbard, Susan; Personna, Y.R.; Ntarlagiannis, D.; Slater, L.; Yee, N.; O'Brien, M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Antisense oligodeoxynucleotide inhibition as a potent diagnostic tool for gene function in plant biology

Description: Antisense oligodeoxynucleotide (ODN) inhibition emerges as an effective means for probing gene function in plant cells. Employing this method we have established the importance of the SUSIBA2 transcription factor for regulation of starch synthesis in barley endosperm, and arrived at a model for the role of the SUSIBAs in sugar signaling and source-sink commutation during cereal endosperm development. In this addendum we provide additional data demonstrating the suitability of the antisense ODN … more
Date: January 15, 2008
Creator: Jansson, Christer; Sun, Chuanxin; Ghebramedhin, Haile; Hoglund, Anna-Stina & Jansson, Christer
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Heavy-Ion Irradiation of Thulium(III) Oxide Targets Prepared by Polymer-Assisted Deposition

Description: Thulium(III) oxide (Tm{sub 2}O{sub 3}) targets prepared by the polymer-assisted deposition (PAD) method were irradiated by heavy-ion beams to test the method's feasibility for nuclear science applications. Targets were prepared on silicon nitride backings (thickness of 1000 nm, 344 {micro}g/cm{sup 2}) and were irradiated with an {sup 40}Ar beam at laboratory frame energy of {approx}210 MeV (50 particle nA). The root mean squared (RMS) roughness prior to irradiation is 1.1 nm for a {approx}250 n… more
Date: September 15, 2008
Creator: Garcia, Mitch A.; Ali, Mazhar N.; Chang, Noel N.; Parsons-Moss, Tashi; Ashby, Paul D.; Gates, Jacklyn M. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Monodisperse Platinum and Rhodium Nanoparticles as Model Heterogeneous Catalysts

Description: Model heterogeneous catalysts have been synthesized and studied to better understand how the surface structure of noble metal nanoparticles affects catalytic performance. In this project, monodisperse rhodium and platinum nanoparticles of controlled size and shape have been synthesized by solution phase polyol reduction, stabilized by polyvinylpyrrolidone (PVP). Model catalysts have been developed using these nanoparticles by two methods: synthesis of mesoporous silica (SBA-15) in the presence … more
Date: August 15, 2008
Creator: Coble, Inger M
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Structure and electrical activity of planar defects in EFG ribbons. First quarterly report, January 1--March 31, 1979

Description: The structure and electrical activity of planar defects in EFG Silicon was investigated by optical, electron beam induced current (EBIC), and transmission electron microscopy (TEM). What appears to be twin boundaries by both optical microscopy + etching, and by EBIC are in reality systems of microtwins, some of which are only a few atomic lattice planes thick. The electrical activity of planar defects appears to be correlated with emission of dislocations especially at termination points. Impur… more
Date: April 15, 1979
Creator: Ast, D.G.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Scanning-Electron-Microscopy Study of Corrosion and Surface Features in Glass Microballoons

Description: Gaseous acid treatment (HBr) of surface-hardened binary glass microballoons results in etching and the growth of salt nodules, tubes or whiskers, depending on moisture conditions. Temperatures from 400/sup 0/C to 625/sup 0/C for 24 h or more are required for the effects to be significant. Numerous imperfections, including craters, are documented on the unexposed interiors surfaces. The evident phase separation and nucleation sites suggest a need for better production controls and post-productio… more
Date: September 15, 1982
Creator: Bystroff, R. I.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Stress studies in EFG. Quarterly progress report, April 1-June 30, 1984

Description: Electrical characterization of defects induced in FZ and CZ silicon stress in four-point bending above 1200/sup 0/C has been started. Techniques to study electrical activity that will permit correlation of defect activity with diffusion length and with room and low temperature EBIC are being developed. Preliminary characterization of defects in ribbon grown at very low speeds of less than 1 cm/min shows that the dislocation density is very low over significant regions of cross section, while re… more
Date: August 15, 1984
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Steam Gasification of Carbon: Catalyst Properties

Description: The objectives of this research are to determine the catalyst composition and concentration for metal oxide (potassium and calcium oxides) catalyzed gasification of carbon. The scope of this research involves determining: the concentration of active catalytic sites (and thus the dispersion), at reaction conditions, as a function of temperature, carbon burnoff, catalyst loading, and catalyst type; the location of catalyst, on the surface, on an atomic scale; catalyst composition; the site-specif… more
Date: September 15, 1990
Creator: Falconer, J.L. & Lauderback, L.L.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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High-temperature oxidation of ion-implanted tantalum. [At 500 and 1000/sup 0/C]

Description: The oxidation of ion-implanted Ta in two different high temperature regimes has been studied. Oxidations were carried out at 500/sup 0/C in Ar/O/sub 2/ mixtures, where oxide growth is known to follow a parabolic rate law in initial stages, and at 1000/sup 0/C in pure O/sub 2/, where a linear-rate behavior obtains. Implanted species include Al, Ce, Cr, Li, Si and Zr at fluences of the order of 10/sup 17//cm/sup 2/. Oxidized samples were studied using Rutherford backscattering, nuclear reaction a… more
Date: September 15, 1982
Creator: Kaufmann, E. N.; Musket, R. G.; Truhan, J. J.; Grabowski, K. S.; Singer, I. L. & Gossett, C. R.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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The effects of moisture on the microstructure of cement-based materials. Progress report, September 15, 1991--January 15, 1993

Description: New experimental techniques that allow the precise measurement of drying shrinkage of cement-based materials within the Environmental Scanning Electron Microscope have been developed. Accuracies of approximately 1% can be obtained on images as small as 20 {times} 20 pixels. Preliminary results on the shrinking of these materials has been obtained and quantitatively analyzed to produce ``maps`` of the deformation process. Samples have been dried from saturation in environments which a approximat… more
Date: July 15, 1992
Creator: Jennings, H. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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The effects of moisture on the microstructure of cement-based materials

Description: New experimental techniques that allow the precise measurement of drying shrinkage of cement-based materials within the Environmental Scanning Electron Microscope have been developed. Accuracies of approximately 1% can be obtained on images as small as 20 {times} 20 pixels. Preliminary results on the shrinking of these materials has been obtained and quantitatively analyzed to produce maps'' of the deformation process. Samples have been dried from saturation in environments which a approximatel… more
Date: July 15, 1992
Creator: Jennings, H. M.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
open access

Transport and deposition of functionalized CdTe nanoparticles in saturated porous media

Description: Comprehensive understanding of the transport and deposition of engineered nanoparticles (NPs) in subsurface is required to assess their potential negative impact on the environment. We studied the deposition behavior of functionalized quantum dot (QD) NPs (CdTe) in different types of sands (Accusand, ultrapure quartz, and iron-coated sand) at various solution ionic strengths (IS). The observed transport behavior in ultrapure quartz and iron-coated sand was consistent with conventional colloid d… more
Date: October 15, 2010
Creator: Torkzaban, S.; Wan, J.; Kim, Y.; Mulvihill, M. & Tokunaga, T. K.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Developing new optical imaging techniques for single particle and molecule tracking in live cells

Description: Differential interference contrast (DIC) microscopy is a far-field as well as wide-field optical imaging technique. Since it is non-invasive and requires no sample staining, DIC microscopy is suitable for tracking the motion of target molecules in live cells without interfering their functions. In addition, high numerical aperture objectives and condensers can be used in DIC microscopy. The depth of focus of DIC is shallow, which gives DIC much better optical sectioning ability than those of ph… more
Date: December 15, 2010
Creator: Sun, Wei
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries Government Documents Department
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Solid state chemistry of rare earth oxides. Technical progress report, 1975--1976. [Pr/sub 7/O/sub 12/; Pr/sub 10/O/sub 18/; HfO/sub 2/. xEr/sub 2/O/sub 3/]

Description: It has been demonstrated that electron microscope images obtained at about 3A resolution for Pr/sub 7/O/sub 12/ are in agreement with calculated images based upon known structures. This establishes the efficacy of crystal structure image interpretation in structural terms, including the defect structure and mechanism of phase reactions, for these types of related phases whose structures are as yet beyond conventional means to determine. Further work on the epsilon (Pr/sub 10/O/sub 18/) phase is… more
Date: April 15, 1976
Creator: Eyring, LeRoy; Skarnulis, A. Jerome; Tuenge, R. T. & Von Dreele, R. B.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Silica Membranes for Hydrogen Separation From Coal Gas. Quarterly Progress Report, December 1, 1992--February 28, 1993

Description: A new reactor system was constructed which can be used for CVD Of SiO{sub 2} layers on porous Vycor tubes. The system is suitable for the usual one-sided deposition and for alternating (or layer-by-layer) deposition whereby the silylating agent and water are passed one at a time in alternating periods. The main advantage of alternating deposition is that it allows membrane deposition using silica precursors for which the homogeneous hydrolysis is fast. As we have demonstrated in earlier work, f… more
Date: April 15, 1993
Creator: Gavalas, G. R.
Item Type: Refine your search to only Report
Partner: UNT Libraries Government Documents Department
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Atomic structure of nanometer-sized amorphous TiO2

Description: Amorphous titania (TiO{sub 2}) is an important precursor for synthesis of single-phase nanocrystalline anatase. We synthesized x-ray amorphous titania by hydrolysis of titanium ethoxide at the ice point. Transmission electron microscopy examination and nitrogen gas adsorption indicated the particle size of the synthesized titania is {approx} 2 nm. Synchrotron wide-angle x-ray scattering (WAXS) was used to probe the atomic correlations in this amorphous sample. Atomic pair-distribution function … more
Date: October 15, 2008
Creator: Zhang, H.; Chen, B.; Banfield, J. F. & Waychunas, G. A.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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Multiple charge density wave transitions in Gd2Te5

Description: Diffraction measurements performed via transmission electron microscopy and high resolution X-ray scattering reveal two distinct charge density wave transitions in Gd{sub 2}Te{sub 5} at T{sub c1} = 410(3) and T{sub c2} = 532(3) K, associated with the on-axis incommensurate lattice modulation and off-axis commensurate lattice modulation respectively. Analysis of the temperature dependence of the order parameters indicates a non-vanishing coupling between these two distinct CDW states.
Date: February 15, 2010
Creator: Shin, K. Y.; Ru, N.; Condron, C. L.; Wu, Y. Q.; Kramer, M. J.; Toney, M. F. et al.
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
open access

Tunable Tensor Voting Improves Grouping of Membrane-Bound Macromolecules

Description: Membrane-bound macromolecules are responsible for structural support and mediation of cell-cell adhesion in tissues. Quantitative analysis of these macromolecules provides morphological indices for damage or loss of tissue, for example as a result of exogenous stimuli. From an optical point of view, a membrane signal may have nonuniform intensity around the cell boundary, be punctate or diffused, and may even be perceptual at certain locations along the boundary. In this paper, a method for the… more
Date: April 15, 2009
Creator: Loss, Leandro A.; Bebis, George & Parvin, Bahram
Item Type: Refine your search to only Article
Partner: UNT Libraries Government Documents Department
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