National Library of Energy BETA

Sample records for ti ng ph

  1. Blue Ng | Open Energy Information

    Open Energy Info (EERE)

    Ng Jump to: navigation, search Name: Blue-Ng Place: Bath, United Kingdom Zip: BA1 1SR Sector: Biomass Product: UK-based company that constructs and operates combined heat and...

  2. PVT-NG sensor final report.

    SciTech Connect (OSTI)

    Mitchell, Dean James; Brusseau, Charles A.

    2012-01-01

    This document is a final report for the polyvinyl toluene (PVT) neutron-gamma (PVT-NG) project, which was sponsored by the Domestic Nuclear Detection Office (DNDO). The PVT-NG sensor uses PVT detectors for both gamma and neutron detection. The sensor exhibits excellent spectral resolution and gain stabilization, which are features that are beneficial for detection of both gamma-ray and neutron sources. In fact, the ability to perform isotope identification based on spectra that were measured by the PVT-NG sensor was demonstrated. As described in a previous report, the neutron sensitivity of the first version of the prototype was about 25% less than the DNDO requirement of 2.5 cps/ng for bare Cf-252. This document describes design modifications that were expected to improve the neutron sensitivity by about 50% relative to the PVT-NG prototype. However, the project was terminated before execution of the design modifications after portal vendors demonstrated other technologies that enable neutron detection without the use of He-3. Nevertheless, the PVT-NG sensor development demonstrated several performance goals that may be useful in future portal designs.

  3. Test Report for NG Sensors GTX-1000.

    SciTech Connect (OSTI)

    Manginell, Ronald P.

    2015-02-01

    This report describes initial testing of the NG Sensor GTX-1000 natural gas monitoring system. This testing showed that the retention time, peak area stability and heating value repeatability of the GTX-1000 were promising for natural gas measurements in the field or at the well head. The repeatability can be less than 0.25% for LHV and HHV for the Airgas standard tested in this report, which is very promising for a first generation prototype. Ultimately this system should be capable of 0.1% repeatability in heating value at significant size and power reductions compared with competing systems.

  4. Emissions from In-Use NG, Propane, and Diesel Fueled Heavy Duty...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    In-Use NG, Propane, and Diesel Fueled Heavy Duty Vehicles Emissions from In-Use NG, Propane, and Diesel Fueled Heavy Duty Vehicles Emissions tests of in-use heavy-duty vehicles ...

  5. Next Generation * Natural Gas (NG)2 Information Requirements--Executive Summary

    Reports and Publications (EIA)

    2000-01-01

    The Energy Information Administration (EIA) has initiated the Next Generation * Natural Gas (NG)2 project to design and implement a new and comprehensive information program for natural gas to meet customer requirements in the post-2000 time frame.

  6. POLICY FLASH 2013-55 FPDS-NG Change Management Notice for the Oklahoma

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Tornado and Storm | Department of Energy POLICY FLASH 2013-55 FPDS-NG Change Management Notice for the Oklahoma Tornado and Storm POLICY FLASH 2013-55 FPDS-NG Change Management Notice for the Oklahoma Tornado and Storm This Flash will be available online at the following website: http://energy.gov/management/office-management/operational-management/procurement-and-acquisition/policy-flashes Questions concerning this policy flash should be directed to Kevin M. Smith, of the Contract and

  7. QER Report: Energy Transmission, Storage, and Distribution Infrastructure | April 2015 NG-1

    Energy Savers [EERE]

    NG-1 Chapter VII Appendix B NATURAL GAS NG-2 QER Report: Energy Transmission, Storage, and Distribution Infrastructure | April 2015 Appendix B: NATURAL GAS Highlights Increasing Supply. The U.S. natural gas industry has undergone changes of unprecedented magnitude and pace. U.S. natural gas production increased 33 percent between 2005 and 2013. Production has shifted from traditional regions, such as the Gulf of Mexico, toward onshore shale gas regions. Most important for infrastructure has been

  8. McPhD

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    is a research code designed to explore the applications of the Haskell programming language to Monte Carlo algorithms. June 29, 2013 software McPhD is a research code designed...

  9. Emissions from In-Use NG, Propane, and Diesel Fueled Heavy Duty Vehicles |

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Department of Energy In-Use NG, Propane, and Diesel Fueled Heavy Duty Vehicles Emissions from In-Use NG, Propane, and Diesel Fueled Heavy Duty Vehicles Emissions tests of in-use heavy-duty vehicles showed that, natural gas- and propane-fueled vehicles have high emissions of NH3 and CO, compared to diesel vehicles, while meeting certification requirements PDF icon deer11_johnson.pdf More Documents & Publications Vehicle Technologies Office Merit Review 2015: Cummins-ORNL\FEERC Emissions

  10. pH optrode

    DOE Patents [OSTI]

    Northrup, M. Allen (Berkeley, CA); Langry, Kevin C. (Tracy, CA)

    1993-01-01

    A process is provided for forming a long-lasting, stable, pH-sensitive dye-acrylamide copolymer useful as a pH-sensitive material for use in an optrode or other device sensitive to pH. An optrode may be made by mechanically attaching the copolymer to a sensing device such as an optical fiber.

  11. DOE/AMO NG Infrastructure R & D & Methane emissions Mitigation workshop

    Office of Environmental Management (EM)

    Proprietary and Confidential to NYSEARCH/NGA DOE/AMO NG INFRASTRUCTURE R & D & METHANE EMISSIONS MITIGATION WORKSHOP November 2014 David Merte & Daphne D'Zurko, NYSEARCH/NGA dmerte@northeastgas.org ddzurko@northeastgas.org NYSEARCH 2 NYSEARCH Program Research Areas * Improved Installation, Maintenance & Repair * Pipeline Integrity/Direct & Remote Assessment * Pipe Location * Leak Detection * Real-time Sensing and Inspection for Distribution * Environment/Reducing Greenhouse

  12. Preparation and lithium intercalation behavior of TiO{sub 2} in aqueous solutions

    SciTech Connect (OSTI)

    Li, Yunjiao, E-mail: yunjiaoli6601@hotmail.com; Li, Lin; Chen, Lingpeng; Wang, Xuanyu; Xu, Cang

    2014-04-01

    Highlights: The poor crystalline anatase phase or amorphous TiO{sub 2} was prepared by TiCl{sub 4} hydrolysis under different pH conditions. Phase transition behavior and lithium intercalation ability of the obtained TiO{sub 2} were found to be related to TiO{sub 2} property. The results indicate that TiO{sub 2} products obtained from TiCl{sub 4} hydrolysis at lower pH are favorable for lithium intercalation. - Abstract: The low crystalline or amorphous TiO{sub 2} was prepared by TiCl{sub 4} hydrolysis in aqueous solutions under different pH conditions at 45 C. The products obtained at lower pH (1.233.10) appear to be nano-sized particles with poor crystalline anatase structure and an uniform particle size distribution, while the product prepared at pH 4.10 presents in a poor crystalline anatase structure and the regular morphology starts to disappear, and the products obtained at higher pH (>6.00) are amorphous and irregular morphology. The hydrolysis products obtained at pH 2.60 and 8.80 were heat-treated at 300, 400, 600, 700 and 800 C for 3 h, respectively, to figure out the phase transition. The differences in phase transition process were observed, which verified the properties difference. The lithium intercalation abilities of the obtained TiO{sub 2} were studied. The results indicated that the TiO{sub 2} obtained at lower pH are more favorable for lithium intercalation and are better precursors.

  13. Philosophy\tof\tNetwork\tOpera3ng Systems\tand\tIntent\tAPIs Inder...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    SDN ONF * ONOS - Carrier-grade SDN network opera3ng system that enables intent via JAVA modules, accessed via REST APIs. * NEMO - Network Modeling language which could serve...

  14. Matrix effect on vibrational frequencies: Experiments and simulations for HCl and HNgCl (Ng = Kr and Xe)

    SciTech Connect (OSTI)

    Kalinowski, Jaroslaw; Rsnen, Markku; Lignell, Antti; Khriachtchev, Leonid; Gerber, R. Benny; Department of Physical Chemistry, Hebrew University, Jerusalem 91904, Israel and Department of Chemistry, University of California, Irvine, California 92697

    2014-03-07

    We study the environmental effect on molecules embedded in noble-gas (Ng) matrices. The experimental data on HXeCl and HKrCl in Ng matrices is enriched. As a result, the H?Xe stretching bands of HXeCl are now known in four Ng matrices (Ne, Ar, Kr, and Xe), and HKrCl is now known in Ar and Kr matrices. The order of the H?Xe stretching frequencies of HXeCl in different matrices is ?(Ne) < ?(Xe) < ?(Kr) < ?(Ar), which is a non-monotonous function of the dielectric constant, in contrast to the classical order observed for HCl: ?(Xe) < ?(Kr) < ?(Ar) < ?(Ne). The order of the H?Kr stretching frequencies of HKrCl is consistently ?(Kr) < ?(Ar). These matrix effects are analyzed theoretically by using a number of quantum chemical methods. The calculations on these molecules (HCl, HXeCl, and HKrCl) embedded in single Ng{sup ?} layer cages lead to very satisfactory results with respect to the relative matrix shifts in the case of the MP4(SDQ) method whereas the B3LYP-D and MP2 methods fail to fully reproduce these experimental results. The obtained order of frequencies is discussed in terms of the size available for the Ng hydrides in the cages, probably leading to different stresses on the embedded molecule. Taking into account vibrational anharmonicity produces a good agreement of the MP4(SDQ) frequencies of HCl and HXeCl with the experimental values in different matrices. This work also highlights a number of open questions in the field.

  15. A=17C (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (See the Isobar Diagram for 17C) The atomic mass excess given by (1988WA18) for 17C is 21035 ± 17 keV. See also (1986AN07). 17C is then stable with respect to 16C + n by 0.73 MeV. Eβ- (max) to 17Ng.s. = 13.16 MeV. See also (1986BI1A). The half-life of 17C has been measured to be 202 ± 17 msec (1986CU01), 220 ± 80 msec (1986DU07), 180 ± 31 msec (1988SA04), and 174 ± 31 msec (1991RE02). Relative intensities of β-delayed gammas were measured by (1986DU07, 1986HU1A, 1986JEZY) [see

  16. Structure of Naegleria Tet-like dioxygenase (NgTet1) in complexes with a reaction intermediate 5-hydroxymethylcytosine DNA

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hashimoto, Hideharu; Pais, June E.; Dai, Nan; Corrêa, Jr., Ivan R.; Zhang, Xing; Zheng, Yu; Cheng, Xiaodong

    2015-08-31

    The family of ten-eleven translocation (Tet) dioxygenases is widely distributed across the eukaryotic tree of life, from mammals to the amoeboflagellate Naegleria gruberi. Like mammalian Tet proteins, the Naegleria Tet-like protein, NgTet1, acts on 5-methylcytosine (5mC) and generates 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC) in three consecutive, Fe(II)- and α-ketoglutarate-dependent oxidation reactions. The two intermediates, 5hmC and 5fC, could be considered either as the reaction product of the previous enzymatic cycle or the substrate for the next cycle. Here we present a new crystal structure of NgTet1 in complex with DNA containing a 5hmC. Along with the previously solvedmore » NgTet1–5mC structure, the two complexes offer a detailed picture of the active site at individual stages of the reaction cycle. In the crystal, the hydroxymethyl (OH-CH2-) moiety of 5hmC points to the metal center, representing the reaction product of 5mC hydroxylation. The hydroxyl oxygen atom could be rotated away from the metal center, to a hydrophobic pocket formed by Ala212, Val293 and Phe295. Such rotation turns the hydroxyl oxygen atom away from the product conformation, and exposes the target CH2 towards the metal-ligand water molecule, where a dioxygen O2 molecule would occupy to initiate the next round of reaction by abstracting a hydrogen atom from the substrate. The Ala212-to-Val (A212V) mutant profoundly limits the product to 5hmC, probably due to the reduced hydrophobic pocket size restricts the binding of 5hmC as a substrate.« less

  17. Enhancing solar photocatalytic detoxification by adsorption of porphyrins onto TiO sub 2

    SciTech Connect (OSTI)

    Majumder, S.A.; Ondrias, M.R. . Dept. of Chemistry); Prairie, M.R.; Shelnutt, J.A. )

    1991-01-01

    Titanium dioxide (TiO{sub 2}) is a known photocatalyst for solar detoxification of water containing organic contaminants including PCB's and dioxins. Unfortunately, the UV light used by the photocatalyst only comprises about 4% of the strong spectrum. Metalloporphyrins strongly absorb in the visible and near infrared region. Using visible light, we have investigated Ni(II) uroporphyrin (NiUroP), Sn(IV)Cl{sub 2} uroporphyrin (SnUroP) and Sn(IV)Cl{sub 2} tetrakis(p-carboxyphenyl) porphyrin (SnTCPP) as possible enhancers of destruction of a model organic compound, salicylic acid (SA), by means of photosensitization of colloidal TiO{sub 2} particles. All three porphyrins are found to adsorb reversibly onto the colloidal TiO{sub 2} upon variation of pH. Adsorption of porphyrins results in the increased colloidal stability of fine TiO{sub 2} particles in the pH range 5--8. While NiUroP on TiO{sub 2} does not show any enhancement of photodestruction, the adsorption of SnUroP increases the destruction rate compared to that of the bare TiO{sub 2} surface. The effect of ambient oxygen on the observed photolability of the Sn porphyrins and enhancement of photodestruction of SA was also investigated. SnTCPP does not photodecompose upon illumination either in the presence or absence of TiO{sub 2}, but neither does it bind to the photocatalyst at pH 6. At pH 4.5 it adsorbs onto TiO{sub 2} but it also photodecompose at this pH. We are attempting to stabilize the adsorbed porphyrins by adding suitable peripheral substituents onto the porphyrin macrocycle. 27 refs., 6 figs.

  18. N,N'-DICYCLOHEXYL-N"-ISOTRIDECYLGUANIDINE AS SUPPRESSOR FOR THE NEXT GENERATION CAUSTIC SIDE SOLVENT EXTRACTION (NG-CSSX) PROCESS

    SciTech Connect (OSTI)

    Duncan, Nathan C; Roach, Benjamin D; Williams, Neil J; Bonnesen, Peter V; Rajbanshi, Arbin; Moyer, Bruce A

    2012-01-01

    ABSTRACT The purity, concentration, and source of the N,N'-dicyclohexyl-N"-isotridecylguanidine (DCiTG) suppressor (guanidine) used in the NG-CSSX process were found to influence solvent performance. As the starting isotridecanol used in the preparation of DCiTG is comprised of a mixture of branched-chain aliphatic alcohols, varying in composition with manufacturer, the resulting DCiTG itself is a mixture. Thus, it is necessary to address how the solvent performance will be affected by the different preparations of the DCiTG solvent component. In this study, four preparations of DCiTG from three sources were analyzed and evaluated for purity and performance, both in the absence and presence of an anionic surfactant impurity.

  19. A=16Al (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not observed) See (1986AN07

  20. A=16Mg (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not observed) See (1986AN07

  1. A=16Na (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not observed) See (1986AN07

  2. A=16Si (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not observed) See (1986AN07

  3. A=19Be (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not observed) See (1983ANZQ

  4. A=19He (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not observed) See (1983ANZQ

  5. A=19Li (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not observed) See (1983ANZQ

  6. Waterless TiO{sub 2} atomic layer deposition using titanium tetrachloride and titanium tetraisopropoxide

    SciTech Connect (OSTI)

    Anderson, Virginia R.; Cavanagh, Andrew S.; Abdulagatov, Aziz I.; Gibbs, Zachary M.; George, Steven M.

    2014-01-15

    The surface chemistry for TiO{sub 2} atomic layer deposition (ALD) typically utilizes water or other oxidants that can oxidize underlying substrates such as magnetic disks or semiconductors. To avoid this oxidation, waterless or oxidant-free surface chemistry can be used that involves titanium halides and titanium alkoxides. In this study, waterless TiO{sub 2} ALD was accomplished using titanium tetrachloride (TiCl{sub 4}) and titanium tetraisopropoxide (TTIP). In situ transmission Fourier transform infrared (FTIR) studies were employed to study the surface species and the reactions during waterless TiO{sub 2} ALD. At low temperatures between 125 and 225??C, the FTIR absorbance spectra revealed that the isopropoxide species remained on the surface after TTIP exposures. The TiCl{sub 4} exposures then removed the isopropoxide species and deposited additional titanium species. At high temperatures between 250 and 300??C, the isopropoxide species were converted to hydroxyl species by ?-hydride elimination. The observation of propene gaseous reaction product by quadrupole mass spectrometry (QMS) confirmed the ?-hydride elimination reaction pathway. The TiCl{sub 4} exposures then easily reacted with the hydroxyl species. QMS studies also observed the 2-chloropropane and HCl gaseous reaction products and monitored the self-limiting nature of the TTIP reaction. Additional studies examined the waterless TiO{sub 2} ALD growth at low and high temperature. Quartz crystal microbalance measurements observed growth rates of ?3?ng/cm{sup 2} at a low temperature of 150??C. Much higher growth rates of ?15?ng/cm{sup 2} were measured at a higher temperature of 250??C under similar reaction conditions. X-ray reflectivity analysis measured a growth rate of 0.55 0.05?/cycle at 250??C. X-ray photoelectron depth-profile studies showed that the TiO{sub 2} films contained low Cl concentrations <1 at. %. This waterless TiO{sub 2} ALD process using TiCl{sub 4} and TTIP should be valuable to prevent substrate oxidation during TiO{sub 2} ALD on oxygen-sensitive substrates.

  7. pH Meter probe assembly

    DOE Patents [OSTI]

    Hale, C.J.

    1983-11-15

    An assembly for mounting a pH probe in a flowing solution, such as a sanitary sewer line, which prevents the sensitive glass portion of the probe from becoming coated with grease, oil, and other contaminants, whereby the probe gives reliable pH indication over an extended period of time. The pH probe assembly utilizes a special filter media and a timed back-rinse feature for flushing clear surface contaminants of the filter. The flushing liquid is of a known pH and is utilized to check performance of the probe. 1 fig.

  8. pH Meter probe assembly

    DOE Patents [OSTI]

    Hale, Charles J. (San Jose, CA)

    1983-01-01

    An assembly for mounting a pH probe in a flowing solution, such as a sanitary sewer line, which prevents the sensitive glass portion of the probe from becoming coated with grease, oil, and other contaminants, whereby the probe gives reliable pH indication over an extended period of time. The pH probe assembly utilizes a special filter media and a timed back-rinse feature for flushing clear surface contaminants of the filter. The flushing liquid is of a known pH and is utilized to check performance of the probe.

  9. Nanocrystalline BaTiO3 powder via ambient conditions sol process (Prop.2001-071)

    SciTech Connect (OSTI)

    Payzant, E Andrew; Wang, X.; Hu, Michael Z.; Blom, Douglas Allen

    2005-01-01

    Nanocrystalline BaTiO{sub 3} particles have been prepared by ambient condition sol (ACS) process starting from soluble precursors of barium and titanium yielding a mixed oxide/hydroxide gel. The gel was peptized and crystallized in water under a refluxing condition. Higher initial pH and Ba/Ti ratio led to smaller crystallite sizes of BaTiO{sub 3} powders. Organic mineralizer, tetramethylammonium hydroxide (TMAH), can adsorb on the BaTiO{sub 3} nuclei and inhibited further growth of the particles. Adding a polymer during BaTiO{sub 3} synthesis led to a smaller particle size and increased redispersibility of the particles in water.

  10. Theoretical investigation of HNgNH{sub 3}{sup +} ions (Ng = He, Ne, Ar, Kr, and Xe)

    SciTech Connect (OSTI)

    Gao, Kunqi; Sheng, Li

    2015-04-14

    The equilibrium geometries, harmonic frequencies, and dissociation energies of HNgNH{sub 3}{sup +} ions (Ng = He, Ne, Ar, Kr, and Xe) were investigated using the following method: Becke-3-parameter-Lee-Yang-Parr (B3LYP), Boese-Matrin for Kinetics (BMK), second-order Mller-Plesset perturbation theory (MP2), and coupled-cluster with single and double excitations as well as perturbative inclusion of triples (CCSD(T)). The results indicate that HHeNH{sub 3}{sup +}, HArNH{sub 3}{sup +}, HKrNH{sub 3}{sup +}, and HXeNH{sub 3}{sup +} ions are metastable species that are protected from decomposition by high energy barriers, whereas the HNeNH{sub 3}{sup +} ion is unstable because of its relatively small energy barrier for decomposition. The bonding nature of noble-gas atoms in HNgNH{sub 3}{sup +} was also analyzed using the atoms in molecules approach, natural energy decomposition analysis, and natural bond orbital analysis.

  11. Determination Of Ph Including Hemoglobin Correction

    DOE Patents [OSTI]

    Maynard, John D. (Albuquerque, NM); Hendee, Shonn P. (Albuquerque, NM); Rohrscheib, Mark R. (Albuquerque, NM); Nunez, David (Albuquerque, NM); Alam, M. Kathleen (Cedar Crest, NM); Franke, James E. (Franklin, TN); Kemeny, Gabor J. (Madison, WI)

    2005-09-13

    Methods and apparatuses of determining the pH of a sample. A method can comprise determining an infrared spectrum of the sample, and determining the hemoglobin concentration of the sample. The hemoglobin concentration and the infrared spectrum can then be used to determine the pH of the sample. In some embodiments, the hemoglobin concentration can be used to select an model relating infrared spectra to pH that is applicable at the determined hemoglobin concentration. In other embodiments, a model relating hemoglobin concentration and infrared spectra to pH can be used. An apparatus according to the present invention can comprise an illumination system, adapted to supply radiation to a sample; a collection system, adapted to collect radiation expressed from the sample responsive to the incident radiation; and an analysis system, adapted to relate information about the incident radiation, the expressed radiation, and the hemoglobin concentration of the sample to pH.

  12. Review. Ernie Perry, PhD

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Mid-America Freight Coalition comments for the Quadrennial Energy Review. Ernie Perry, PhD University of Wisconsin - Madison ebperry@wisc.edu August 8 2014 Chicago, Il. Thank you ...

  13. A=10F (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (Not illustrated) Not observed: see (1979AJ01). See also (1988AJ01

  14. A=10Ne (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (Not illustrated) Not observed: see (1979AJ01). See also (1988AJ01

  15. A=10O (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (Not illustrated) Not observed: see (1979AJ01). See also (1988AJ01

  16. A=17Al (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Al (1993TI07) (Not observed) See (1983ANZQ, 1988WA18, 1992AV03).

  17. A=17He (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not illustrated) Not observed: see (1986AJ04, 1988POZS

  18. A=17Li (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not illustrated) Not observed: see (1986AJ04, 1988POZS

  19. A=17Mg (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mg (1993TI07) (Not observed) See (1983ANZQ, 1988WA18, 1992AV03).

  20. A=17P (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not observed) See (1983ANZQ, 1988WA18, 1992AV03

  1. A=17Si (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Si (1993TI07) (Not observed) See (1983ANZQ, 1988WA18, 1992AV03).

  2. A=18He (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not illustrated) Not observed: See (1982AV1A, 1983ANZQ

  3. A=20Al, etc. (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    98TI06) (Not observed) See (1972AJ02, 1983ANZQ, 1986AN07

  4. A=20Be (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    98TI06) (Not observed) See (1977CE05, 1983ANZQ, 1986AN07, 1987SIZX

  5. A=20n (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    98TI06) (Not observed) See (1977CE05, 1983ANZQ, 1986AN07, 1987SIZX

  6. Prevention of hydrogen embrittlement by a TiO/sub 2/ surface layer

    SciTech Connect (OSTI)

    Nelson, J.G.; Murray, G.T.

    1984-03-01

    This article discusses the problem of hydrogen embrittlement of steels and its prevention, particularly by surface coatings. Preventive methods to date have largely been directed toward microstructure control. Because of the absence of data on prevention of hydrogen embrittlement by TiO/sub 2/ films, and because of the data that indicate that hydrogen diffusion in TiO/sub 2/ films is very low, the authors explore here the effect of a titanium oxide film on hydrogen embrittlement of 15-5 PH (an ARMCO Steel Corp. product) stainless steel.

  7. Jeff Griffin, Ph. D. Associate Laboratory Director

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Griffin, Ph. D. Associate Laboratory Director Environmental Stewardship Savannah River National Laboratory DOE-EM Robotics Team Visit to SRNL SRNL-MS-2015-00246 Rev. 0 December 7, 2015 SRNL Development and Adaptation of Technologies for Nuclear Applications 2 SRNL - National Laboratory for Environmental Management Multi-program national laboratory with broad portfolio Key role to translate basic science and technology to deployable and operable solutions * Develop detailed understanding of

  8. Development of the Next-Generation Caustic-Side Solvent Extraction (NG-CSSX) Process for Cesium Removal from High-Level Tank Waste

    SciTech Connect (OSTI)

    Moyer, Bruce A; Bonnesen, Peter V; Delmau, Laetitia Helene; Sloop Jr, Frederick {Fred} V; Williams, Neil J; Birdwell Jr, Joseph F; Lee, Denise L; Leonard, Ralph; Fink, Samuel D; Peters, Thomas B.; Geeting, Mark W

    2011-01-01

    This paper describes the chemical performance of the Next-Generation Caustic-Side Solvent Extraction (NG-CSSX) process in its current state of development for removal of cesium from the alkaline high-level tank wastes at the Savannah River Site (SRS) in the US Department of Energy (USDOE) complex. Overall, motivation for seeking a major enhancement in performance for the currently deployed CSSX process stems from needs for accelerating the cleanup schedule and reducing the cost of salt-waste disposition. The primary target of the NG-CSSX development campaign in the past year has been to formulate a solvent system and to design a corresponding flowsheet that boosts the performance of the SRS Modular CSSX Unit (MCU) from a current minimum decontamination factor of 12 to 40,000. The chemical approach entails use of a more soluble calixarene-crown ether, called MaxCalix, allowing the attainment of much higher cesium distribution ratios (DCs) on extraction. Concurrently decreasing the Cs-7SB modifier concentration is anticipated to promote better hydraulics. A new stripping chemistry has been devised using a vitrification-friendly aqueous boric acid strip solution and a guanidine suppressor in the solvent, resulting in sharply decreased DCs on stripping. Results are reported herein on solvent phase behavior and batch Cs distribution for waste simulants and real waste together with a preliminary flowsheet applicable for implementation in the MCU. The new solvent will enable MCU to process a much wider range of salt feeds and thereby extend its service lifetime beyond its design life of three years. Other potential benefits of NG-CSSX include increased throughput of the SRS Salt Waste Processing Facility (SWPF), currently under construction, and an alternative modular near-tank application at Hanford.

  9. Structure of Naegleria Tet-like dioxygenase (NgTet1) in complexes with a reaction intermediate 5-hydroxymethylcytosine DNA

    SciTech Connect (OSTI)

    Hashimoto, Hideharu; Pais, June E.; Dai, Nan; Corra, Jr., Ivan R.; Zhang, Xing; Zheng, Yu; Cheng, Xiaodong

    2015-08-31

    The family of ten-eleven translocation (Tet) dioxygenases is widely distributed across the eukaryotic tree of life, from mammals to the amoeboflagellate Naegleria gruberi. Like mammalian Tet proteins, the Naegleria Tet-like protein, NgTet1, acts on 5-methylcytosine (5mC) and generates 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC) and 5-carboxylcytosine (5caC) in three consecutive, Fe(II)- and ?-ketoglutarate-dependent oxidation reactions. The two intermediates, 5hmC and 5fC, could be considered either as the reaction product of the previous enzymatic cycle or the substrate for the next cycle. Here we present a new crystal structure of NgTet1 in complex with DNA containing a 5hmC. Along with the previously solved NgTet15mC structure, the two complexes offer a detailed picture of the active site at individual stages of the reaction cycle. In the crystal, the hydroxymethyl (OH-CH2-) moiety of 5hmC points to the metal center, representing the reaction product of 5mC hydroxylation. The hydroxyl oxygen atom could be rotated away from the metal center, to a hydrophobic pocket formed by Ala212, Val293 and Phe295. Such rotation turns the hydroxyl oxygen atom away from the product conformation, and exposes the target CH2 towards the metal-ligand water molecule, where a dioxygen O2 molecule would occupy to initiate the next round of reaction by abstracting a hydrogen atom from the substrate. The Ala212-to-Val (A212V) mutant profoundly limits the product to 5hmC, probably due to the reduced hydrophobic pocket size restricts the binding of 5hmC as a substrate.

  10. Un~ted States Env~ronmental Monltor~ng EPA.600 '4-88, 021 Envtronmental Protect~on Systems Laboratory DOE/OP/00539/060

    Office of Legacy Management (LM)

    Env~ronmental Monltor~ng EPA.600 '4-88, 021 Envtronmental Protect~on Systems Laboratory DOE/OP/00539/060 Agency P 0. Box 93478 June 1988 Las Vegas NV 89193-5478 Research and Development Off-Site Environmental Monitoring Report Radiation Monitoring Around United States 1 ' 7 L 8 f Nuclear Test Areas This page intentionally left blank EPA-60014-88-021 DOE/DPI0053?-060 May 1988 OFF-SITE ENVIRONMENTAL MONITORING REPORT R a d i a t i o n M o n i t o r i n g Around U n i t e d States Nuclear Test

  11. Nadya A. Fouad, Ph.D Romila Singh, Ph.D

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Nadya A. Fouad, Ph.D Romila Singh, Ph.D University of Wisconsin-Milwaukee WHY WOMEN LEAVE ENGINEERING " There is little to no RESPECT for women in male-dominated fields." " Still getting asked if I can handle being in a mostly male work environment in interviews in 2009 - I've been an engineer for 9 years, obviously I can. I know when I'm asked that question, I HAVE NO CHANCE AT THE JOB . It is nice they brought me in for equal opportunity survey points but don't waste my time if

  12. Mark Elless, Ph.D. | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Mark Elless, Ph.D. About Us Mark Elless, Ph.D. - Technology Manager, Bioenergy Technologies Office Most Recent Biofuels and Barbecue Chips: Small Business Develops Process to Create Versatile Chemicals May 16

  13. Ng_NERSC_ASCR.pptx

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of the cavity shape due to fabrication errors. This discovery was achieved as a team effort between SLAC, TOPS, and JLab which underscores the importance of the SciDAC...

  14. A=20He (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    He (1998TI06) (Not observed) See (1977CE05, 1983ANZQ, 1986AN07, 1987SIZX).

  15. A=20Li (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Li (1998TI06) (Not observed) See (1977CE05, 1983ANZQ, 1986AN07, 1987SIZX).

  16. A=5n (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (Not illustrated) See also the A = 5 introductory discussion titled A = 5 resonance parameters.

  17. Enhanced photocatalytic efficiency of NiS/TiO{sub 2} composite catalysts using sunset yellow, an azo dye under day light illumination

    SciTech Connect (OSTI)

    Rajamanickam, D.; Dhatshanamurthi, P.; Shanthi, M.

    2015-01-15

    Highlights: NiS/TiO{sub 2} was successfully synthesized by solgel method. This new method of preparation gives a homogeneous dispersion of NiS on TiO{sub 2}. Degradation activity of NiS/TiO{sub 2} is found to be more efficient than other catalysts. Addition of oxidants enhances the degradation efficiency significantly. COD measurements reveal the complete mineralization of dye molecules. The catalyst is found to be reusable. - Abstract: To improve the solar light induced photocatalytic application performances of TiO{sub 2}, in this study, the NiS modified TiO{sub 2} composite photocatalysts with various ratios of NiS to TiO{sub 2} were prepared by solgel method. The catalyst was characterized by X-ray diffraction (XRD), high resolution scanning electron microscope (HR-SEM), high resolution transmission electron microscope (HR-TEM), energy dispersive spectra (EDS), diffuse reflectance spectra (DRS), photoluminescence spectra (PL), X-ray photoelectron spectroscopy (XPS), and BrunauerEmmettTeller (BET) surface area measurement methods. The photocatalytic activity of NiS/TiO{sub 2} was investigated for the degradation of sunset yellow (SY) in aqueous solution using solar light. The NiS/TiO{sub 2} is found to be more efficient than prepared TiO{sub 2} and TiO{sub 2}P25 at pH 7 for the mineralization of SY. The effects of operational parameters such as the amount of photocatalyst, dye concentration and initial pH on photo mineralization of SY have been analyzed. The degradation was strongly enhanced in the presence of oxidants such as H{sub 3}K{sub 5}O{sub 18}S{sub 4} (Oxone), KIO{sub 4}, and KBrO{sub 3}. The mineralization of SY has been identified by COD measurements. The catalyst is found to be reusable.

  18. The role of adsorption in decomposition of dyes on TiO{sub 2} and N-modified TiO{sub 2} photocatalysts under UV and visible light irradiations

    SciTech Connect (OSTI)

    Bubacz, Kamila; Tryba, Beata; Morawski, Antoni W.

    2012-11-15

    Graphical abstract: Influence of pH and zeta potential of TiO{sub 2} based photocatalysts on the adsorption and degradation of MB under UV irradiation. Highlights: ? Adsorption of dyes on TiO{sub 2}/N accelerated their decomposition under visible light. ? pH of solution and the PZC of the TiO{sub 2} surface influence the adsorption of dyes. ? Under UV irradiation oxidation of pollutants with OH radicals is the most powerful. -- Abstract: Photoactivities of TiO{sub 2} based photocatalysts towards dyes decomposition was studied by consider their adsorption abilities. It was proved that zeta potential and PZC (point zero charge) of photocatalyst surface as well as pH of solution strongly influenced adsorption of tested dyes, Methylene Blue (MB) and Reactive Red 198 (RR198). These dyes underwent the photocatalytic decomposition by two ways, OH radicals attack and direct oxidation with photogenerated holes. The latter one is more efficient in case of better contact of pollutant with the photocatalysts surface and is dominant under visible light irradiation, where insignificant amount of OH radicals is formed. The former one is powerful under UV irradiation and is a key factor in decomposition of dyes regardless of their adsorption abilities.

  19. Synthesis and Characterization of Photocatalytic TiO 2 -ZnFe 2 O 4 Nanoparticles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Srinivasan, Sesha S.; Wade, Jeremy; Stefanakos, Elias K.

    2006-01-01

    A new coprecipimore » tation/hydrolysis synthesis route is used to create a TiO 2 -ZnFe 2 O 4 nanocomposite that is directed towards extending the photoresponse of TiO 2 from UV to visible wavelengths ( > 400   nm ). The effect of TiO 2 's accelerated anatase-rutile phase transformation due to the presence of the coupled ZnFe 2 O 4 narrow-bandgap semiconductor is evaluated. The transformation's dependence on pH, calcinations temperature, particle size, and ZnFe 2 O 4 concentration has been analyzed using XRD, SEM, and UV-visible spectrometry. The requirements for retaining the highly photoactive anatase phase present in a ZnFe 2 O 4 nanocomposite are outlined. The visible-light-activated photocatalytic activity of the TiO 2 -ZnFe 2 O 4 nanocomposites has been compared to an Aldrich TiO 2 reference catalyst, using a solar-simulated photoreactor for the degradation of phenol.« less

  20. Synthesis and Characterization of PhotocatalyticTiO2-ZnFe2O4Nanoparticles

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Srinivasan, Sesha S.; Wade, Jeremy; Stefanakos, Elias K.

    2006-01-01

    A new coprecipitation/hydrolysis synthesis route is used to create aTiO2-ZnFe2O4nanocomposite that is directed towards extending the photoresponse ofTiO2from UV to visible wavelengths (>400?nm). The effect ofTiO2's accelerated anatase-rutile phase transformation due to the presence of the coupledZnFe2O4narrow-bandgap semiconductor is evaluated. The transformation's dependence on pH, calcinations temperature, particle size, andZnFe2O4concentration has been analyzed using XRD, SEM, and UV-visible spectrometry. The requirements for retaining the highly photoactive anatase phase present in aZnFe2O4nanocomposite are outlined. The visible-light-activated photocatalytic activity of theTiO2-ZnFe2O4nanocomposites has been compared to an AldrichTiO2reference catalyst, using a solar-simulated photoreactor formorethe degradation of phenol.less

  1. High Flux Ti Nanofiltration Membrane

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Susan MacKay, Ph.D., Cerahelix, Inc. U.S. DOE Advanced Manufacturing Office Program Review Meeting Washington, D.C. May 28-29, 2015 This presentation does not contain any...

  2. High Flux Ti Nanofiltration Membrane

    Broader source: Energy.gov (indexed) [DOE]

    Susan MacKay, Ph.D., Cerahelix, Inc. U.S. DOE Advanced Manufacturing Office Program Review Meeting Washington, D.C. May 28-29, 2015 This presentation does not contain any proprietary, confidential, or otherwise restricted information. Project Objective To develop a ceramic filter that can separate complex mixtures at high temperature and low pH. Unique nanoscale features of the filter will enable it to perform faster, while using less energy and less pretreatment chemicals compared to competing

  3. Young PhDs in Physics | Jefferson Lab

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Ph.D.s in physics Young PhDs (left to right) William Luo, Jasmine Ellis, Shaun Lightfoot and Prakriti Verma made Oobleck with mechanical designer Joyce Miller during their visit to JLab. Young PhDs in Physics August 29, 2003 Jefferson Lab welcomes youngsters participating in summer science camp. Educating and exciting today's youth about science and technology is an important adjunct to Jefferson Lab's scientific mission. On July 16, the Department of Energy laboratory, located in Newport News,

  4. NREL: Photovoltaics Research - Emily Warren, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    philosophy degree in engineering for sustainable development from the University of Cambridge in 2006. She completed her Ph.D. at Caltech, studying the growth and energy...

  5. Adaora Nwokoye, Ph.D | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Adaora Nwokoye, Ph.D - Science and Technology Policy Fellow, Office of Energy Efficiency and Renewable Energy Most Recent Small Business Innovation Research Projects to Make a Big ...

  6. NREL: Photovoltaics Research - John Wohlgemuth, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    John Wohlgemuth, Ph.D. Principal Scientist Photo of John Wohlgemuth. 303-384-7982 Task Focus: Standards development, module failure analysis and the development of accelerated...

  7. J. Chris Ford, Ph.D. | Department of Energy

    Broader source: Energy.gov (indexed) [DOE]

    Chris Ford, Ph.D. - Technical Advisor to the Director Office of Economic Impact and Diversity Most Recent by Chris Ford Unlocking Growth Opportunities for Minority Businesses...

  8. A=16He (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not illustrated) This nucleus has not been observed. See (1982AV1A, 1983ANZQ, 1986AJ04

  9. A=19Mg (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mg (1995TI07) (Not observed) See (1987AJ02) and (1987GU1K, 1987PO01, 1993HI08

  10. A=16Li (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Li (1993TI07) (Not illustrated) This nucleus has not been observed. Shell model studies (1988POZS) are used to predict J and the magnetic dipole moment....

  11. Consideration of Factors Affecting Strip Effluent PH and Sodium Content

    SciTech Connect (OSTI)

    Peters, T.

    2015-07-29

    A number of factors were investigated to determine possible reasons for why the Strip Effluent (SE) can sometimes have higher than expected pH values and/or sodium content, both of which have prescribed limits. All of the factors likely have some impact on the pH values and Na content.

  12. Activity-based protein profiling of secreted cellulolytic enzyme activity dynamics in Trichoderma reesei QM6a, NG14, and RUT-C30

    SciTech Connect (OSTI)

    Anderson, Lindsey N.; Culley, David E.; Hofstad, Beth A.; Chauvigne-Hines, Lacie M.; Zink, Erika M.; Purvine, Samuel O.; Smith, Richard D.; Callister, Stephen J.; Magnuson, Jon M.; Wright, Aaron T.

    2013-12-01

    Development of alternative, non-petroleum based sources of bioenergy that can be applied in the short-term find great promise in the use of highly abundant and renewable lignocellulosic plant biomass.1 This material obtained from different feedstocks, such as forest litter or agricultural residues, can yield liquid fuels and other chemical products through biorefinery processes.2 Biofuels are obtained from lignocellulosic materials by chemical pretreatment of the biomass, followed by enzymatic decomposition of cellulosic and hemicellulosic compounds into soluble sugars that are converted to desired chemical products via microbial metabolism and fermentation.3, 4 To release soluble sugars from polymeric cellulose multiple enzymes are required, including endoglucanase, exoglucanase, and ?-glucosidase.5, 6 However, the enzymatic hydrolysis of cellulose into soluble sugars remains a significant limiting factor to the efficient and economically viable utilization of lignocellulosic biomass for transport fuels.7, 8 The primary industrial source of cellulose and hemicellulases is the mesophilic soft-rot fungus Trichoderma reesei,9 having widespread applications in food, feed, textile, pulp, and paper industries.10 The genome encodes 200 glycoside hydrolases, including 10 cellulolytic and 16 hemicellulolytic enzymes.11 The hypercellulolytic catabolite derepressed strain RUT-C30 was obtained through a three-step UV and chemical mutagenesis of the original T. reesei strain QM6a,12, 13 in which strains M7 and NG14 were intermediate, having higher cellulolytic activity than the parent strain but less activity and higher catabolite repression than RUT-C30.14 Numerous methods have been employed to optimize the secreted enzyme cocktail of T. reesei including cultivation conditions, operational parameters, and mutagenesis.3 However, creating an optimal and economical enzyme mixture for production-scale biofuels synthesis may take thousands of experiments to identify.

  13. Method for producing rapid pH changes

    DOE Patents [OSTI]

    Clark, John H. (Los Alamos, NM); Campillo, Anthony J. (Los Alamos, NM); Shapiro, Stanley L. (Los Alamos, NM); Winn, Kenneth R. (Los Alamos, NM)

    1981-01-01

    A method of initiating a rapid pH change in a solution by irradiating the solution with an intense flux of electromagnetic radiation of a frequency which produces a substantial pK change to a compound in solution. To optimize the resulting pH change, the compound being irradiated in solution should have an excited state lifetime substantially longer than the time required to establish an excited state acid-base equilibrium in the solution. Desired pH changes can be accomplished in nanoseconds or less by means of picosecond pulses of laser radiation.

  14. NREL: Photovoltaics Research - Nick Bosco, PhD

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Nick Bosco, PhD Senior Scientist Photo of vv 303-384-6337 Nick.Bosco@nrel.gov Task Focus: Failure Analysis and Accelerated Testing Specializes in: Infrared imaging and other...

  15. NREL: Photovoltaics Research - Nancy M. Haegel, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Nancy M. Haegel, Ph.D. Center Director, Materials Science Photo of Nancy Haegel 303 384 6548 Nancy.Haegel@nrel.gov Dr. Nancy Haegel is Center Director of the Materials Science...

  16. NREL: Photovoltaics Research - Mark Campanelli, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Mark Campanelli, Ph.D. Postdoctoral Researcher 303-384-6469 Mark.Campanelli@nrel.gov Mark Campanelli graduated with a master's degree and a doctorate in mathematics from Montana...

  17. NREL: Photovoltaics Research - Benjamin G. Lee, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Benjamin G. Lee, Ph.D. Research Scientist Photo of Benjamin Lee 303-384-7869 Benjamin.Lee@nrel.gov Benjamin Lee earned his bachelor's degree from the California Institute of...

  18. NREL: Photovoltaics Research - Bill McMahon, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Bill McMahon, Ph.D. Senior Scientist 303-384-6578 Bill.McMahon@nrel.gov Dr. Bill McMahon received a bachelor's degree in engineering physics from the Colorado School of Mines in...

  19. NREL: Biomass Research - Michael T. Guarnieri, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    T. Guarnieri, Ph.D. Photo of Michael Guarnieri Dr. Guarnieri is a Research Scientist in the National Bioenergy Center's Applied Biology group at the National Renewable Energy Laboratory. He earned his Ph.D. in biochemistry and molecular genetics, with a joint degree in biophysics and structural biology, at the University of Colorado School of Medicine in 2009, where his research focused on structural and biophysical characterization of bacterial two-component signaling proteins. Prior to his

  20. NREL: Photovoltaics Research - Glenn Teeter, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Glenn Teeter, Ph.D. Interfacial and Surface Science Group Manager 303-384-6664 Glenn.Teeter@nrel.gov Glenn Teeter is manager of the Interfacial and Surface Science Group at the National Renewable Energy Laboratory (NREL). He received his bachelor of science degree in physics from Stetson University and his Ph.D. in physics from the University of Texas at Austin under the supervision of Professor James Erskine. Dr. Teeter completed a postdoctoral appointment at the Pacific Northwest National

  1. Tina Kaarsberg, Ph.D. | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Tina Kaarsberg, Ph.D. About Us Tina Kaarsberg, Ph.D. - SBIR/STTR Program Manager, Office of Energy Efficiency and Renewable Energy Most Recent New SBIR All-in-One Web Tool Helps Small Businesses Navigate Nine Websites October 27 Small Business Innovation Research Projects to Make a Big Impact on Clean Energy Economy June 16 Small Business Innovation Research: Bringing Clean Energy Technologies to the Marketplace May

  2. Comparing Metal Leaching and Toxicity from High pH, Low pH, and High Ammonia Fly Ash

    SciTech Connect (OSTI)

    Palumbo, Anthony Vito; Phillips, Jana Randolph; Fagan, Lisa Anne; Drake, Meghan M; Ruther, Rose Emily; Fisher, L. Suzanne; Amonette, J. E.

    2007-01-01

    Previous work with both class F and class C fly ash indicated minimal leaching from most fly ashes tested. However, the addition of NOx removal equipment might result in higher levels of ammonia in the fly ash. We have recently been testing fly ash with a wide range of pH (3.7-12.4) originating from systems with NOx removal equipment. Leaching experiments were done using dilute CaCl2 solutions in batch and columns and a batch nitric acid method. All methods indicated that the leaching of heavy metals was different in the highest ammonia sample tested and the high pH sample. However, toxicity testing with the Microtox system has indicated little potential toxicity in leachates except for the fly ash at the highest pH (12.4). When the leachate from the high pH fly ash was neutralized, toxicity was eliminated.

  3. Comparing metal leaching and toxicity from high pH, low pH, and high ammonia fly ash

    SciTech Connect (OSTI)

    Palumbo, Anthony V.; Tarver, Jana R.; Fagan, Lisa A.; McNeilly, Meghan S.; Ruther, Rose; Fisher, L. S.; Amonette, James E.

    2007-07-01

    Previous work with both class F and class C fly ash indicated minimal leaching from most fly ashes tested. However, the addition of NOx removal equipment might result in higher levels of ammonia in the fly ash. We have recently been testing fly ash with a wide range of pH (3.712.4) originating from systems with NOx removal equipment. Leaching experiments were done using dilute CaCl2 solutions in batch and columns and a batch nitric acid method. All methods indicated that the leaching of heavy metals was different in the highest ammonia sample tested and the high pH sample. However, toxicity testing with the Microtox* system has indicated little potential toxicity in leachates except for the fly ash at the highest pH (12.4). When the leachate from the high pH fly ash was neutralized, toxicity was eliminated.

  4. Near-infrared noninvasive spectroscopic determination of pH

    DOE Patents [OSTI]

    Alam, Mary K. (P.O. Box 1083, Cedar Crest, NM 87008); Robinson, Mark R. (1415 Calle del Ranchero NE, Albuquerque, NM 87106)

    1998-08-11

    Methods and apparatus for, preferably, determining noninvasively and in vitro pH in a human. The non-invasive method includes the steps of: generating light at three or more different wavelengths in the range of 1000 nm to 2500 nm; irradiating blood containing tissue; measuring the intensities of the wavelengths emerging from the blood containing tissue to obtain a set of at least three spectral intensities v. wavelengths; and determining the unknown values of pH. The determination of pH is made by using measured intensities at wavelengths that exhibit change in absorbance due to histidine titration. Histidine absorbance changes are due to titration by hydrogen ions. The determination of the unknown pH values is performed by at least one multivariate algorithm using two or more variables and at least one calibration model. The determined pH values are within the physiological ranges observed in blood containing tissue. The apparatus includes a tissue positioning device, a source, at least one detector, electronics, a microprocessor, memory, and apparatus for indicating the determined values.

  5. A=18Mg, etc. (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not observed) See (1986AN07) and (1983ANZQ). See also the results of calculations of β+/electron capture half lives for neutron deficient nuclei in (1993HI08

  6. A=6B (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (Not illustrated) Not observed: see ( 1984AJ01, 1989GR06 [6Li(π+, π-) at Eπ+ = 180, 240 MeV], 1993PO11 [properties of exotic light nuclei]) (1998SU18

  7. A=6C (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (Not illustrated) Not observed: see (1979AJ01, 1984AJ01, 1989GR06 [6Li(π+, π-) at Eπ+ = 180, 240 MeV], 1993PO11 [properties of exotic light nuclei]) (1998SU18

  8. A=8Be (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 8Be) GENERAL: References to articles on general properties of 8Be published since the previous review (1988AJ01) are grouped into...

  9. A=9N (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (Not illustrated) Not observed: see (1988AJ01). Mass excesses of 46.56 and 46.40 MeV have been estimated from two different mass formulae (2000PO32). 9N would then be...

  10. A=18Li (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Li (1995TI07) (Not illustrated) 18Li has not been observed. Shell model calculations described in (1988POZS) predict the ground-state magentic dipole moment and charge and matter...

  11. A=8He (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 8He) GENERAL: References to articles on general properties of 8He published since the previous review (1988AJ01) are grouped into...

  12. A=9C (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 9C) GENERAL: References to articles on general properties of 9C published since the previous review (1988AJ01) are grouped into categories...

  13. A=7He (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (See Energy Level Diagrams for 7He) GENERAL: References to articles on general properties of 7He published since the previous review (1988AJ01) are grouped into...

  14. A=9Be (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 9Be) GENERAL: References to articles on general properties of 9Be published since the previous review (1988AJ01) are grouped into...

  15. A=10C (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 10C) GENERAL: References to articles on general properties of 10C published since the previous review (1988AJ01) are grouped into...

  16. A=8B (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 8B) GENERAL: References to articles on general properties of 8B published since the previous review (1988AJ01) are grouped into categories...

  17. A=10N (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (Not illustrated) GENERAL: References to articles on general properties of 10N published since the previous review (1988AJ01) are grouped into categories and listed,...

  18. A=10Li (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 10Li) GENERAL: References to articles on general properties of 10Li published since the previous review (1988AJ01) are grouped into...

  19. A=6Be (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (See Energy Level Diagrams for 6Be) GENERAL: References to articles on general properties of 6Be published since the previous review (1988AJ01) are grouped into...

  20. A=9He (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See the Isobar Diagram for 9He) GENERAL: References to articles on general properties of 9He published since the previous review (1988AJ01) are grouped into categories...

  1. A=5Li (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (See Energy Level Diagrams for 5Li) GENERAL: References to articles on general properties of 5Li published since the previous review (1988AJ01) are grouped into...

  2. A=9Li (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 9Li) GENERAL: References to articles on general properties of 9Li published since the previous review (1988AJ01) are grouped into...

  3. A=9B (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 9B) GENERAL: References to articles on general properties of 9B published since the previous review (1988AJ01) are grouped into categories...

  4. A=10He (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 10He) GENERAL: References to articles on general properties of 10He published since the previous review (1988AJ01) are grouped into...

  5. TiBor Skin - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Startup America Startup America Advanced Materials Advanced Materials Find More Like This Return to Search TiBor Skin Y-12 National Security Complex Contact Y12 About This Technology Publications: PDF Document Publication Fact Sheet (336 KB) PDF Document Publication Presentation (400 KB) PDF Document Publication Patent Application Publication (2,825 KB) Technology Marketing Summary Y-12 invites interested companies to license its patent-pending method known as TiBor Skin. This two-part

  6. Instability of Hydrogenated TiO2

    SciTech Connect (OSTI)

    Nandasiri, Manjula I.; Shutthanandan, V.; Manandhar, Sandeep; Schwarz, Ashleigh M.; Oxenford, Lucas S.; Kennedy, John V.; Thevuthasan, Suntharampillai; Henderson, Michael A.

    2015-11-06

    Hydrogenated TiO2 (H-TiO2) is toted as a viable visible light photocatalyst. We report a systematic study on the thermal stability of H-implanted TiO2 using X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), Rutherford backscattering spectrometry (RBS) and nuclear reaction analysis (NRA). Protons (40 keV) implanted at a ~2 atom % level within a ~120 nm wide profile of rutile TiO2(110) were situated ~300 nm below the surface. NRA revealed that this H-profile broadened preferentially toward the surface after annealing at 373 K, dissipated out of the crystal into vacuum at 473 K, and was absent within the beam sampling depth (~800 nm) at 523 K. Photoemission showed that the surface was reduced in concert with these changes. Similar anneals had no effect on pristine TiO2(110). The facile bulk diffusivity of H in rutile, as well as its activity toward interfacial reduction, significantly limits the utilization of H-TiO2 as a photocatalyst. This work was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle. The research was performed using the Environmental Molecular Sciences Laboratory (EMSL), a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

  7. Measurement and control of pH in hydrothermal solutions

    SciTech Connect (OSTI)

    Wesolowski, D.J.; Palmer, D.A.; Mesmer, R.E.

    1995-12-31

    Hydrogen-electrode concentration cells with liquid junction are routinely used to measure the pH of aqueous solutions from 0 to 300 C. Results include the dissociation constants of common acids and bases and the hydrolysis and complexation of metal ions in aqueous electrolytes over a wide range of salinities. Recently, we have utilized these cells to examine the sorption of H{sup +} on mineral surfaces, the solubility of minerals with continuous in situ pH measurement, and the thermal decompositon rates of organic acids.

  8. PhD Comics' guide to fusion makes the complex understandable...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    PhD Comics' guide to fusion makes the complex understandable June 12, 2014 (Photo by PhD Comics, www.phdcomics.comTV) A scene from PhD Comics' Jorge Cham's video "What is Fusion" ...

  9. Strong Energy-momentum Dispersion of Phonon Dressed Carriers in the Lightly Doped Band Insulator SrTiO3

    SciTech Connect (OSTI)

    Meevasana, Warawat

    2010-05-26

    Much progress has been made recently in the study of the effects of electron-phonon (el-ph) coupling in doped insulators using angle resolved photoemission (ARPES), yielding evidence for the dominant role of el-ph interactions in underdoped cuprates. As these studies have been limited to doped Mott insulators, the important question arises how this compares with doped band insulators where similar el-ph couplings should be at work. The archetypical case is the perovskite SrTiO{sub 3} (STO), well known for its giant dielectric constant of 10000 at low temperature, exceeding that of La{sub 2}CuO{sub 4} by a factor of 500. Based on this fact, it has been suggested that doped STO should be the archetypical bipolaron superconductor. Here we report an ARPES study from high-quality surfaces of lightly doped SrTiO{sub 3}. Comparing to lightly doped Mott insulators, we find the signatures of only moderate electron-phonon coupling: a dispersion anomaly associated with the low frequency optical phonon with a {lambda}{prime} {approx} 0.3 and an overall bandwidth renormalization suggesting an overall {lambda}{prime} {approx} 0.7 coming from the higher frequency phonons. Further, we find no clear signatures of the large pseudogap or small polaron phenomena. These findings demonstrate that a large dielectric constant itself is not a good indicator of el-ph coupling and highlight the unusually strong effects of the el-ph coupling in doped Mott insulators.

  10. Flexible high-temperature pH probe

    DOE Patents [OSTI]

    Bielawski, John C. (Scotia, NY); Outwater, John O. (Cambridge, MA); Halbfinger, George P. (Schenectady, NY)

    2003-04-22

    A flexible pH probe device is provided for use in hot water and other high temperature environments up to about 590.degree. F. The pH probe includes a flexible, inert tubular probe member, an oxygen anion conducting, solid state electrolyte plug located at the distal end of the tubular member, oxide powder disposed at the distal end of the tubular member; a metal wire extending along the tubular member and having a distal end in contact with the oxide powder so as to form therewith an internal reference electrode; and a compression fitting forming a pressure boundary seal around a portion of the tubular member remote from the distal end thereof. Preferably, the tubular member is made of polytetrafluoroethylene, and the solid state electrolyte plug is made of stabilized zirconia. The flexibility of the probe member enables placement of the electrode into the area of interest, including around corners, into confined areas and the like.

  11. Morphology, deformation, and defect structures of TiCr{sub 2} in Ti-Cr alloys

    SciTech Connect (OSTI)

    Chen, K.C.; Allen, S.M.; Livingston, J.D.

    1992-12-31

    The morphologies and defect structures of TiCr{sub 2} in several Ti-Cr alloys have been examined by optical metallography, x-ray diffraction, and transmission electron microscopy (TEM), in order to explore the room-temperature deformability of the Laves phase TiCr{sub 2}. The morphology of the Laves phase was found to be dependent upon alloy composition and annealing temperature. Samples deformed by compression have also been studied using TEM. Comparisons of microstructures before and after deformation suggest an increase in twin, stacking fault, and dislocation density within the Laves phase, indicating some but not extensive room-temperature deformability.

  12. NREL: Biomass Research - Edward J. Wolfrum, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Edward J. Wolfrum, Ph.D. Photo of Edward J. Wolfrum I am a Senior Researcher and Manager at the National Renewable Energy Laboratory's National Bioenergy Center in Golden, Colorado. I have experience in the technical management of research projects for both governmental and private clients, including financial management, training and supervision of research staff, subcontract monitoring, and general laboratory management. I currently lead the Biomass Compositional Analysis section, a team of

  13. NREL: Biomass Research - Glen Ferguson, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Glen Ferguson, Ph.D. Photo of Glen Ferguson Glen Ferguson is currently a Postdoctoral Fellow in the National Bioenergy Center at the National Renewable Energy Laboratory (NREL). He is studying the computational design of solid catalysts to improve the production of renewable liquid fuels. Previously Glen was a postdoctoral fellow in the Material Science Division of Argonne National Laboratory. At Argonne he studied energy storage and nanocatalysis. This work resulted in several publications, as

  14. NREL: Biomass Research - Jack Ferrell, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Jack Ferrell, Ph.D. Photo of Jack Ferrell Jack Ferrell works in the Thermochemical Catalysis R&D group. He manages tasks on analytical development for pyrolysis oil, and on kinetic and hydrodynamic modeling of biomass-to-biofuels processes. Research Interests Thermochemical conversion of biomass to fuels and chemicals Development and validation of kinetic (and microkinetic) models Coupling of kinetic models to hydrodynamic models for process scale-up Development and standardization of

  15. NREL: Biomass Research - Jeffrey G. Linger, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Jeffrey G. Linger, Ph.D. Photo of Jeffrey Linger Jeff Linger is a Research Scientist in the Applied Biology group of the National Bioenergy Center (NBC) within the National Renewable Energy Laboratory (NREL). Dr. Linger joined NREL in 2007 as a post-doctoral fellow studying the production of biofuels. Specifically, Dr. Linger used molecular biology techniques to assess the feasibility of converting the microorganism Zymomonas mobilis into a consolidated bioprocessing organism through the

  16. NREL: Biomass Research - Jesse Hensley, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Jesse Hensley, Ph.D. Photo of Jesse Hensley Jesse Hensley manages heterogeneous catalysis research in the Thermochemical Process R&D division of the National Bioenergy Center. Jesse currently serves as section supervisor as well as principal investigator for pyrolysis oil upgrading (deoxygenation) and gas-to-liquids R&D. His group includes senior engineers and scientists, post doctoral researchers, graduate students, technicians, and undergraduate interns. Jesse's group operates 3

  17. NREL: Biomass Research - Lieve Laurens, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lieve Laurens, Ph.D. I am a senior research scientist in the Bioprocess Research and Development group at the National Renewable Energy Laboratory. My research experience is primarily analytical biochemistry-investigating ways to understand lipid, carbohydrate, and protein production and composition in microalgae and other microorganisms. A large fraction of my time I dedicate to leading the DOE/EERE-funded Algal Biomass Characterization project at the National Bioenergy Center and coordinating

  18. NREL: Biomass Research - Mark F. Davis, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    F. Davis, Ph.D. Photo of Mark Davis Dr. Mark Davis is the Thermochemical Conversion Platform Leader at the National Renewable Energy Laboratory (NREL). He also currently serves as the Focus Area Lead for the characterization and modeling activities in the BioEnergy Science Center (BESC) led by Oak Ridge National Laboratory. His research program is focused on integrating multivariate statistical data analysis and spectroscopic methods such as nuclear magnetic resonance (NMR) and

  19. NREL: Biomass Research - Seonah Kim, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Seonah Kim, Ph.D. Photo of Seonah Kim Seonah Kim is a scientist in the Biochemical Process Research team in the National Bioenergy Center at the National Renewable Energy Laboratory (NREL). Her research background combines extensive experience in both classical molecular dynamics simulations and quantum mechanical modeling of transition states. She has been working on understanding and designing catalysts for the decomposition of both lignin and cellulose. At NREL she has developed catalytic

  20. NREL: Photovoltaics Research - Andriy Zakutayev, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Andriy Zakutayev, Ph.D. Scientist 303-384-6467 Andriy.Zakutayev@nrel.gov Andriy Zakutayev is a scientist working in the field of renewable energy technologies. The applied direction of his work includes development of new photovoltaic materials and devices using materials-by-design methods. The basic direction involves research on non-equilibrium synthesis of metastable materials as well as fundamental surface and interface science. Zakutayev uses high-throughput combinatorial approaches to

  1. NREL: Photovoltaics Research - Hasitha Mahabaduge, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Hasitha Mahabaduge, Ph.D. Postdoctoral Researcher Photo of Hasitha Mahabaduge 303-384-7350 Hasitha.Mahabaduge@nrel.gov Dr. Hasitha Mahabaduge's primary research interests include fabrication and characterization of flexible CdTe solar cells, transparent conducting oxide and highly resistive transparent layers for photovoltaic devices, and semiconductor physics. He earned his doctorate in physics from the University of Toledo, Ohio, in 2013. He received his bachelor's degree in computational

  2. NREL: Photovoltaics Research - Stephan Lany, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Stephan Lany, Ph.D. Scientist V Photo of Stephan Lany 303-384-6652 Stephan.Lany@nrel.gov Stephan Lany is a computational materials scientist with a background in electronic structure calculations for semiconducting materials. He received his doctorate in physics in 2002 from the Universität des Saarlandes, Germany, and joined NREL in 2003 as a postdoctoral researcher. As a staff scientist, he is currently leading computational research activities in support of the Energy Frontier Research

  3. NREL: Photovoltaics Research - Teresa Barnes, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Teresa Barnes, Ph.D. Senior Scientist 303-384-6682 Teresa.Barnes@nrel.gov Dr. Barnes received a bachelor's degree in chemical engineering from the University of Maryland in 2000 and a doctorate in chemical engineering from the Colorado School of Mines in 2004. She studied plasma-assisted chemical vapor deposition chemistry and transparent conducting oxide growth as a graduate student. She came to NREL as a postdoctoral researcher to continue working on transparent conducting oxides and began

  4. Carrier-Controlled Ferromagnetism in SrTiO3

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Moetakef, Pouya; Williams, James R.; Ouellette, Daniel G.; Kajdos, Adam P.; Goldhaber-Gordon, David; Allen, S. James; Stemmer, Susanne

    2012-06-27

    Magnetotransport and superconducting properties are investigated for uniformly La-doped SrTiO3 films and GdTiO3/SrTiO3 heterostructures, respectively. GdTiO3/SrTiO3 interfaces exhibit a high-density 2D electron gas on the SrTiO3 side of the interface, while, for the SrTiO3 films, carriers are provided by the dopant atoms. Both types of samples exhibit ferromagnetism at low temperatures, as evidenced by a hysteresis in the magnetoresistance. For the uniformly doped SrTiO3 films, the Curie temperature is found to increase with doping and to coexist with superconductivity for carrier concentrations on the high-density side of the superconducting dome. The Curie temperature of the GdTiO3/SrTiO3 heterostructures scales with themore » thickness of the SrTiO3 quantum well. The results are used to construct a stability diagram for the ferromagnetic and superconducting phases of SrTiO3.« less

  5. Giant persistent photoconductivity in BaTiO{sub 3}/TiO{sub 2} heterostructures

    SciTech Connect (OSTI)

    Plodinec, Milivoj; anti?, Ana; Gajovi?, Andreja; Zavanik, Janez; ?eh, Miran

    2014-10-13

    The persistent photoconductivity (PPC) effect in nanotube arrays of barium titanate and TiO{sub 2} (BTO/TiO{sub 2}NT) was studied at room temperature under daylight illumination. The BTO/TiO{sub 2}NT heterostructures exhibited a giant PPC effect that was six orders of magnitude higher than the dark conductivity, followed by a slow relaxation for 3 h. The PPC in this material was explained by the existence of defects at the surfaces and the interfaces of the investigated heterostructures. The sample was prepared using a two-step synthesis: the anodization of a Ti-foil and a subsequent hydrothermal synthesis. The structural and electrical characteristics were studied by micro-Raman spectroscopy, field-emission-gun scanning electron microscopy, and impedance spectroscopy.

  6. A=18Na (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not observed) 18Na has not been observed; its atomic mass excess has been estimated to be 25.32 MeV (1993AU05); it is then unbound with respect to proton emission by 1.6 MeV: see (1978AJ03). See also (1986AN07) and (1983ANZQ

  7. A=5Be (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (See the Isobar Diagram for 5Be) See also the A = 5 introductory discussion titled A = 5 resonance parameters. The absence of any group structure in the neutron spectrum in the reaction 3He(3He, n)5Be at E(3He) = 18.0 to 26.0 MeV indicates that 5Beg.s

  8. A=20B (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of 20B is predicted to be 69.08 MeV (1974TH01). 20B is then unstable with respect to breakup into 19B + n by 0.9 MeV: see 19B in (1995TI07) and (1978AJ03, 1983ANZQ) and see the...

  9. A=18C (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    of the 48Ca(18O, 18C)48Ti reaction. 18C is then bound by 4.188 MeV with respect to breakup into 17C + n. See also (1982FI10, 1987AJ02, 1992WA22). 1. 18C(-)18N Qm 11.807 The...

  10. The corrosivity and passivity of sputtered Mg-Ti alloys

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Song, Guang -Ling; Unocic, Kinga A.; Meyer, III, Harry M.; Cakmak, Ercan; Brady, Michael P.; Gannon, Paul E.; Himmer, Phil; Andrews, Quinn

    2015-11-30

    Our study explored the possibility of forming a “stainless” Mg–Ti alloy. The electrochemical behavior of magnetron-sputtered Mg–Ti alloys was measured in a NaCl solution, and the surface films on the alloys were examined by XPS, SEM and TEM. Increased corrosion resistance was observed with increased Ti content in the sputtered Mg–Ti alloys, but passive-like behavior was not reached until the Ti level (atomic %) was higher than the Mg level. Moreover, the surface film that formed on sputtered Mg–Ti based alloys in NaCl solution was thick, discontinuous and non-protective, whereas a thin, continuous and protective Mg and Ti oxide filmmore » was formed on a sputtered Ti–Mg based alloy.« less

  11. Structural characterization of the FeTiO{sub 3}-MnTiO{sub 3} solid solution

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Structural characterization of the FeTiO{sub 3}-MnTiO{sub 3} solid solution Citation Details In-Document Search Title: Structural characterization of the FeTiO{sub 3}-MnTiO{sub 3} solid solution We have synthesized the (Mn{sub 1-x}Fe{sub x})TiO{sub 3} (0.0{<=}x{<=}1.0) solid solution compounds by high-temperature sintered methods, and characterized their crystal structures by combining X-ray diffraction, Moessbauer spectroscopy and Raman

  12. NREL: Photovoltaics Research - Craig L. Perkins, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Craig L. Perkins, Ph.D. Scientist V Photo of Craig Perkins craig.perkins@nrel.gov Joining NREL in 2000, Dr. Perkins currently is a senior scientist in the laboratory's Interfacial and Surface Science group, where he works with photovoltaic and energy materials. He received a Bachelor of Science in Chemistry from the University of Florida in 1990, going on to study gas-phase chemistry of van der Waals molecules at the University of Central Florida. He switched gears to the solid state in 1992,

  13. NREL: Photovoltaics Research - Lorelle Mansfield, Ph.D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Lorelle Mansfield, Ph.D. Scientist 303-384-7884 Lorelle.Mansfield@nrel.gov Lorelle Mansfield is a Scientist in the Thin Film Material Science &amp; Processing group at NREL. Her current work focuses on Cu(In,Ga)Se2 (CIGS) thin films for photovoltaic applications. In particular, she is developing rapid two-step selenization processes for high-efficiency solar cells. Other topics of interest include enhancing the Voc of CIGS devices through alkali post-deposition treatments, increasing the Ga

  14. W. Alexander Williams, Ph.D Designation and Certification Manager

    Office of Legacy Management (LM)

    March 20, 1995 W. Alexander Williams, Ph.D Designation and Certification Manager EM-421 Quince Orchard U.S. Department of Energy Washington, DC 20585-0002 L -=kj SUBJECT: FINAL REPORT-RADIOLOGICAL SURVEY OF THE F AMERICAN MANUFACTURING COMPANY OF TEXA WORTH, TEXAS I ,d Sl I lRMER , FORT Dear Dr. Williams: The Environmental,Survey and Site Assessment Program (ESSAP) of the C for Science and Education (ORISE) conducted radiological survey activii American Manufacturing Company of Texas Site in

  15. PhD Comics' guide to fusion makes the complex understandable | Princeton

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Plasma Physics Lab PhD Comics' guide to fusion makes the complex understandable June 12, 2014 (Photo by PhD Comics, www.phdcomics.com/TV) A scene from PhD Comics' Jorge Cham's video "What is Fusion" features interviews with PPPL physicists on location and employs animation to allow the scientists to explain magnetic fusion. (Photo by (Photo by PhD Comics, www.phdcomics.com/TV) ) (Photo by PhD Comics, www.phdcomics.com/TV) A scene from PhD Comics' Jorge Cham's video "What is

  16. Structural and Morphological Difference Between Ti/TiN/TiCN Coatings Grown in Multilayer and Graded Form

    SciTech Connect (OSTI)

    Restrepo, E.; Baena, A.; Agudelo, C.; Castillo, H.; Devia, A.; Marino, A.

    2006-12-04

    Thin films can be grown in super-lattice, multilayers and graded form, having each one advantages and disadvantages. The difference between multilayer and graded coatings is the interface. In multilayers the interface is abrupt and in graded coatings it is diffuse. The interface influences many chemical and physical properties of the materials, and its choice depends on the application. Graded coatings have the advantage of having gradual properties such as thermal expansion coefficient and lattice parameter, avoiding adherence problems due to good match between their component materials. In this work the comparison between some properties of coatings grown as multilayer and graded is performed. The materials are produced using the sputtering DC technique because of its facility to control the deposition parameters and generate a slow growth. The target is a disc of titanium and the samples are made of stainless steel 304. The working gases are argon, nitrogen and methane, which are mixed according to the material to be produced, i.e. Ti layer is grown with argon, the TiN film is produced with a mixture of argon and nitrogen, and the TiCN material is obtained mixing argon, nitrogen and methane. These materials are characterized with AFM in order to determine grain size and with XPS studying the chemical composition and performing depth profiles.

  17. PH adjustment of power plant cooling water with flue gas/fly...

    Office of Scientific and Technical Information (OSTI)

    Patent: PH adjustment of power plant cooling water with flue gasfly ash Citation Details In-Document Search Title: PH adjustment of power plant cooling water with flue gasfly ash...

  18. PH adjustment of power plant cooling water with flue gas/fly...

    Office of Scientific and Technical Information (OSTI)

    PH adjustment of power plant cooling water with flue gasfly ash Citation Details In-Document Search Title: PH adjustment of power plant cooling water with flue gasfly ash A...

  19. With 400th Ph.D. grad, UW-Madison celebrates a half century of...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    With 400th Ph.D. grad, UW-Madison celebrates a half century of fusion energy American Fusion News Category: U.S. Universities Link: With 400th Ph.D. grad, UW-Madison celebrates a...

  20. Brine pH Modification Scale Control Technology. 2. A Review.pdf...

    Open Energy Info (EERE)

    Brine pH Modification Scale Control Technology. 2. A Review.pdf Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Brine pH Modification Scale...

  1. A Review Corrosion of TI Grade 7 and Other TI Alloys in Nuclear Waste Repository Environments

    SciTech Connect (OSTI)

    F. Hua; K. Mon; P. Pasupathi; G. Gordon

    2004-05-11

    Titanium alloy degradation modes are reviewed in relation to their performance in repository environments. General corrosion, localized corrosion, stress corrosion cracking, hydrogen induced cracking, microbially influenced corrosion, and radiation-assisted corrosion of Ti alloys are considered. With respect to the Ti Grade 7 drip shields selected for emplacement in the repository at Yucca Mountain, general corrosion, hydrogen induced cracking, and radiation-assisted corrosion will not lead to failure within the 10,000 year regulatory period; stress corrosion cracking (in the absence of disruptive events) is of no consequence to barrier performance; and localized corrosion and microbially influenced corrosion are not expected to occur. To facilitate the discussion, Ti Grades 2, 5, 7, 9, 11, 12, 16, 17, 18, and 24 are included in this review.

  2. Low Cost TiO2 Nanoparticles - Energy Innovation Portal

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Solar Photovoltaic Solar Photovoltaic Advanced Materials Advanced Materials Find More Like This Return to Search Low Cost TiO2 Nanoparticles Sandia National Laboratories Contact SNL About This Technology Publications: PDF Document Publication Market Sheet (866 KB) TEM image of TiO<sub>2 </sub>nanoparticles taken at 50kx magnification demonstrates discrete and stable end product. TEM image of TiO2 nanoparticles taken at 50kx magnification demonstrates discrete and stable end product.

  3. Thermoelastic Analysis of a Vibrating TiB/Ti Cantilever Beam Using Differential Thermography

    SciTech Connect (OSTI)

    Byrd, Larry; Wyen, Travis; Byrd, Alex

    2008-02-15

    Differential thermography has been used to detect the fluctuating temperatures due the thermoelastic effect for a number of years. This paper examines functionally graded TiB/Ti cantilever beams excited on an electromechanical shaker in fully reversed bending. Finite difference analysis of specimens was used to look at the effect of heat conduction, convection and the fundamental frequency on the surface temperature distribution and compared to experimental data. The thermoelastic effect was also used to detect cracking and the stress field at the tip of the fixture during fatigue.

  4. Ab initio Study of He Stability in hcp-Ti

    SciTech Connect (OSTI)

    Dai, Yunya; Yang, Li; Peng, SM; Long, XG; Gao, Fei; Zu, Xiaotao T.

    2010-12-20

    The stability of He in hcp-Ti was studied using ab initio method based on density functional theory. The results indicate that a single He atom prefers to occupy the tetrahedral site rather than the octahedral site. The interaction of He defects with Ti atoms has been used to explain the relative stabilities of He point defects in hcp-Ti. The relative stability of He defects in hcp-Ti is useful for He clustering and bubble nucleation in metal tritides, which provides the basis for development of improved atomistic models.

  5. Nature of Transactions (TI) Code | National Nuclear Security...

    National Nuclear Security Administration (NNSA)

    Nature of Transactions (TI) Code* Code: Description: A Initiates lease and financial responsibility of DOE-owned material B Transfer of lease and financial responsiblity of ...

  6. Ferroelectric Self-assembled PbTiO3 Perovskite Nanostructures...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Perovskite Nanostructures onto (100)SrTiO3 Substrates from a Novel Microemulsion-aided Sol-Gel Preparation Figure 1. PbTiO3 nanostructures onto (100) SrTiO3 substrates....

  7. Equation of State Model Quality Study for Ti and Ti64.

    SciTech Connect (OSTI)

    Wills, Ann Elisabet; Sanchez, Jason James

    2015-02-01

    Titanium and the titanium alloy Ti64 (6% aluminum, 4% vanadium and the balance ti- tanium) are materials used in many technologically important applications. To be able to computationally investigate and design these applications, accurate Equations of State (EOS) are needed and in many cases also additional constitutive relations. This report describes what data is available for constructing EOS for these two materials, and also describes some references giving data for stress-strain constitutive models. We also give some suggestions for projects to achieve improved EOS and constitutive models. In an appendix, we present a study of the 'cloud formation' issue observed in the ALEGRA code. This issue was one of the motivating factors for this literature search of available data for constructing improved EOS for Ti and Ti64. However, the study shows that the cloud formation issue is only marginally connected to the quality of the EOS, and, in fact, is a physical behavior of the system in question. We give some suggestions for settings in, and improvements of, the ALEGRA code to address this computational di culty.

  8. A=10B (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See Energy Level Diagrams for 10B) GENERAL: References to articles on general properties of 10B published since the previous review (1988AJ01) are grouped into categories and listed, along with brief descriptions of each item, in the General Tables for 10B located on our website at: (www.tunl.duke.edu/nucldata/General_Tables/10b.shtml). See also Table Prev. Table 10.18 preview 10.18 [Table of Energy Levels] (in PDF or PS). μ = +1.80064475 ± 0.00000057 μN: see (1989RA17); Q = +84.72

  9. A=19B (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not illustrated) 19B has been observed in the bombardment of Be by 12 MeV/A 56Fe ions (1984MU27) and in the fragmentation of 44 MeV/A 40Ar (1988GU1A) and 55 MeV/A 48Ca (1991MU19). See also (1989DE52). The mass excess adopted by (1993AU05) is 59.360 ± 0.400 MeV. Shell model predictions for low-lying levels are discussed in (1992WA22). See also (1989PO1K, 1990LO11

  10. A=20N (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    98TI06) (Not illustrated) 20N is particle stable. Its atomic mass excess is 21.770 ± 0.050 MeV (1995AU04). It has been observed in heavy-ion transfer (1989OR03) and projectile fragmentation reactions (1987GI05, 1988DUZT, 1988MU08, 1990MU06, 1991OR01) and in target fragmentation reactions (1988WO09, 1991RE02, 1993WOZZ). See also the review (1988VI1D). Mass measurements were reported in (1987GI05, 1988WO09, 1989OR03, 1991OR01, 1993WOZZ). Nuclear matter rms radii have been derived from

  11. A=3He (1987TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    1987TI07) GENERAL: Ground State: Jπ = 1/2+, μ = -2.127624 ± 0.0000011 nm, M - A = 14.93132 ± 0.00003 MeV. General properties of the ground state of the A = 3 system are under 3H above. The wave function is predominantly S-state (~ 90%) with S'-state (1 - 2%) and D-state (~ 9%) admixtures (1975FI08, 1980PA12, 1984CI05, 1984CI09). For 3He the measured magnetic moment is μ = -2.127624 ± 0.0000011 nm (1978LEZA, 1978NE12). Calculations which include both impulse and pion exchange contributions

  12. A=3Li (1987TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    1987TI07) GENERAL: The previous compilation (1975FI08) listed a small number of references reporting on the four reactions discussed below. Only one of the experiments cited contained any evidence for a 3p resonance, and the discussion suggested that the observed enhancement in 3He(p, n) was more likely a final state interaction. In the work reported since (1975FI08) and listed below, only (1974POZN) contains any mention of the tri-proton, and no evidence for its existence was observed. 1. 2H(p,

  13. A=4HE (1992TI02)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    He (1992TI02) (See Energy Level Diagrams for 4He) GENERAL: Ground state:Due to non-central forces, the wave function for the Jπ = 0+ ground state of 4He can be a positive-parity mixture of three 1S0, six 3P0, and five 5D0 orthogonal states (1967BE74). Of course, the symmetric S-wave component is the dominant part of the wavefunction, with significant D-wave and almost negligible P-wave contributions. Since the D-state admixture can be inferred from measurements such as the tensor analyzing

  14. A=5He (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (See Energy Level Diagrams for 5He) GENERAL: References to articles on general properties of 5He published since the previous review (1988AJ01) are grouped into categories and listed, along with brief descriptions of each item, in the General Tables for 5He located on our website at (www.tunl.duke.edu/NuclData/General_Tables/5he.shtml). See also Table Prev. Table 5.1 preview 5.1 [Table of Energy Levels] (in PDF or PS). See also the A = 5 introductory discussion titled A = 5 resonance

  15. A=6n (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (Not illustrated) 6n has not been observed. See (1979AJ01, 1988AJ01) and references cited there. More recently (1990AL40) reports a search for 6n in a 14C(7Li, 6n) activation experiment at E(7Li) = 82 MeV. No evidence for 6n was obtained. The method of angular potential functions was used by (1989GO18) in a calculation of the properties of multi-neutron systems which indicated that these systems have no bound states. The ground state energy of a six-neutron drop has been computed with

  16. A=7Be (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (See Energy Level Diagrams for 7Be) GENERAL: References to articles on general properties of 7Be published since the previous review (1988AJ01) are grouped into categories and listed, along with brief descriptions of each item, in the General Tables for 7Be located on our website at (www.tunl.duke.edu/NuclData/General_Tables/7be.shtml). See also Table Prev. Table 7.7 preview 7.7 [Table of Energy Levels] (in PDF or PS). The interaction nuclear radius of 7Be is 2.22 ± 0.02 fm

  17. O Ti-tE LOVE

    Office of Legacy Management (LM)

    ' ItqQtJulRl' IICt' O Ti-tE LOVE ~t?Al. . . At2D Al.CLkTED IChTTEtt~ . ' . . . : . ' . i I . . . . .mr TttE HOt\' ORAULE~ STANLEY FItZl:; SFCAKER ' . : ,J WE\J i' ORti STATE ASSH' rtrLY l r . . isay 29,.1980 Consultant to the Kew York ' , .' .I, " ..' . ,"' ! -. . . : . . . I.. . . . . ~. ,:- 9.. :. .' , * Ill . ,.. , ,i / All . ' %: : . : . . -. ;:. * :... . _ -. .' . . . I . ' J n' f armed. ?%c firtdingo and backup documentatiin embodied in thi preliminafy report compel the Task

  18. Fabrication of TiO{sub 2} Thick Film for Photocatalyst from Commercial TiO{sub 2} Powder

    SciTech Connect (OSTI)

    Asteti, S. Fuji; Syarif, D. Gustaman

    2008-03-17

    Photocatalytic activity of TiO{sub 2} thick film ceramics made of commercial TiO{sub 2} powder has been studied. The TiO{sub 2} powder was nano sized one that was derived from dried TiO{sub 2} suspension. The TiO{sub 2} suspension was made by pouring some blended commercial TiO{sub 2} powder into some amount of water. The paste of TiO{sub 2} was made by mixing the nano sized TiO{sub 2} powder with organic vehicle and glass frit. The paste was spread on a glass substrate. The paste was dried at 100 deg. C and heated at different temperatures (400 deg. C and 500 deg. C) for 60 minutes to produce thick film ceramics. The photocatalytic activity of these films was evaluated by measuring the concentration of a solution of methylene blue where the thick films were inside after being illuminated by UV light at various periods of times. The initial concentration of the methylene blue solution was 5 ppm. Structural analyses were carried out by X-ray diffraction (XRD). The XRD analyses showed that the produced thick film ceramic had mainly crystal structure of anatase. According to the photocatalytical data, it was known that the produced thick film ceramics were photocatalyst which were capable of decomposing an organic compound such as the methylene blue.

  19. Influence of acidic pH on hydrogen and acetate production by an

    Office of Scientific and Technical Information (OSTI)

    electrosynthetic microbiome (Journal Article) | DOE PAGES Influence of acidic pH on hydrogen and acetate production by an electrosynthetic microbiome « Prev Next » Title: Influence of acidic pH on hydrogen and acetate production by an electrosynthetic microbiome Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (~5). Hydrogen

  20. Microfluidic device having an immobilized pH gradient and PAGE gels for

    Office of Scientific and Technical Information (OSTI)

    protein separation and analysis (Patent) | SciTech Connect Microfluidic device having an immobilized pH gradient and PAGE gels for protein separation and analysis Citation Details In-Document Search Title: Microfluidic device having an immobilized pH gradient and PAGE gels for protein separation and analysis Disclosed is a novel microfluidic device enabling on-chip implementation of a two-dimensional separation methodology. Previously disclosed microscale immobilized pH gradients (IPG) are

  1. Microfluidic device having an immobilized pH gradient and page gels for

    Office of Scientific and Technical Information (OSTI)

    protein separation and analysis (Patent) | SciTech Connect Microfluidic device having an immobilized pH gradient and page gels for protein separation and analysis Citation Details In-Document Search Title: Microfluidic device having an immobilized pH gradient and page gels for protein separation and analysis Disclosed is a novel microfluidic device enabling on-chip implementation of a two-dimensional separation methodology. Previously disclosed microscale immobilized pH gradients (IPG) are

  2. Electrostatic carrier doping of GdTiO{sub 3}/SrTiO{sub 3} interfaces

    SciTech Connect (OSTI)

    Moetakef, Pouya; Cain, Tyler A.; Zhang, Jack Y.; Janotti, Anderson; Van de Walle, Chris G.; Stemmer, Susanne; Ouellette, Daniel G.; Allen, S. James; Klenov, Dmitri O.; Rajan, Siddharth

    2011-12-05

    Heterostructures and superlattices consisting of a prototype Mott insulator, GdTiO{sub 3}, and the band insulator SrTiO{sub 3} are grown by molecular beam epitaxy and show intrinsic electronic reconstruction, approximately 1/2 electron per surface unit cell at each GdTiO{sub 3}/SrTiO{sub 3} interface. The sheet carrier densities in all structures containing more than one unit cell of SrTiO{sub 3} are independent of layer thicknesses and growth sequences, indicating that the mobile carriers are in a high concentration, two-dimensional electron gas bound to the interface. These carrier densities closely meet the electrostatic requirements for compensating the fixed charge at these polar interfaces. Based on the experimental results, insights into interfacial band alignments, charge distribution, and the influence of different electrostatic boundary conditions are obtained.

  3. PhD Comics' guide to fusion makes the complex understandable | Princeton

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Plasma Physics Lab PhD Comics' guide to fusion makes the complex understandable By Jeanne Jackson DeVoe June 12, 2014 Tweet Widget Google Plus One Share on Facebook A scene from PhD Comics' Jorge Cham's video "What is Fusion" features interviews with PPPL physicists on location and employs animation to allow the scientists to explain magnetic fusion. (Photo by PhD Comics, www.phdcomics.com/TV) A scene from PhD Comics' Jorge Cham's video "What is Fusion" features

  4. ORISE: Recent Ph.D. recipients wanted for Energy Efficiency and...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Recent Ph.D. recipients wanted for Energy Efficiency and Renewable Energy Research Awards Applications being accepted through the end of April FOR IMMEDIATE RELEASE March 4, 2014...

  5. Microfluidic device having an immobilized pH gradient and PAGE...

    Office of Scientific and Technical Information (OSTI)

    microfluidic device enabling on-chip implementation of a two-dimensional separation methodology. Previously disclosed microscale immobilized pH gradients (IPG) are combined with...

  6. Development of Ti/Ti{sub 3}Sn functionally gradient material produced by eutectic bonding method

    SciTech Connect (OSTI)

    Kirihara, S.; Takeda, M.; Tsujimoto, T. [Ibaraki Univ., Hitachi (Japan). Faculty of Engineering] [Ibaraki Univ., Hitachi (Japan). Faculty of Engineering

    1996-07-15

    Although many materials which have a single function have been developed, future needs are anticipated to include materials which have various functions. A functionally gradient material (FGM) which has characteristics of two different materials is a promising candidate for multi-functional material. The present methods for production of FGM, however, are very complicated and costly. In this study the authors answer the serious problem of high production cost by fabricating the FGM by a eutectic bonding method. This fabrication method includes structural control of FGM by changing the cooling process. They describe Ti/Ti{sub 3}Sn FGM obtained by the eutectic bonding method, and tell how the structure of its composition gradient part is changed by controlling the cooling process.

  7. Nondestructive evaluation of Ni-Ti shape memory alloy

    SciTech Connect (OSTI)

    Meir, S.; Gordon, S.; Karsh, M.; Ayers, R.; Olson, D. L.; Wiezman, A.

    2011-06-23

    The nondestructive evaluation of nickel titanium (Ni-Ti) alloys for applications such as heat treatment for biomaterials applications (dental) and welding was investigated. Ni-Ti alloys and its ternary alloys are valued for mechanical properties in addition to the shape memory effect. Two analytical approaches were perused in this work. Assessment of the microstructure of the alloy that determines the martensitic start temperature (Ms) of Ni-Ti alloy as a function of heat treatment, and secondly, an attempt to evaluate a Friction Stir Welding, which involves thermo-mechanical processing of the alloy.

  8. A=16B (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (Not illustrated) This nucleus has not been observed in the 4.8 GeV proton bombardment of a uranium target. It is particle unstable. Its mass excess is predicted to be 37.97 MeV; it would then be unstable with respect to decay into 15B + n by 0.93 MeV. See (1985WA02, 1986AJ04). The ground state is predicted to have Jπ = 0- and the first three excited states are predicted to lie at 0.95, 1.10, and 1.55 MeV [Jπ = 2-, 3-, 4-] in a (0 + 1)ℏω space shell model calculation. See (1983ANZQ,

  9. A=16C (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (See Energy Level Diagrams for 16C) GENERAL: See Table Prev. Table 16.1 preview 16.1 [General Table] (in PDF or PS) and Table Prev. Table 16.2 preview 16.2 [Table of Energy Levels] (in PDF or PS) here. 1. 16C(β-)16N Qm = 8.012 The half life of 16C is 0.747 ± 0.008 sec. It decays to 16N*(0.12, 3.35, 4.32) [Jπ = 0-, 1+, 1+]: see Table Prev. Table 16.3 preview 16.3 (in PDF or PS) and (1993CH06). See also (1986AJ04) and see (1986KI05, 1988WA1E, 1992WA1L) for theoretical discussions of

  10. A=16F (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (See Energy Level Diagrams for 16F) GENERAL: See Table Prev. Table 16.29 preview 16.29 [General Table] (in PDF or PS) here. See also Table Prev. Table 16.30 preview 16.30 [Table of Energy Levels] (in PDF or PS) here. 1. (a) 14N(3He, n)16F Qm = -0.957 (b) 14N(3He, np)15O Qm = -0.421 Obserevd neutron groups from reaction (a) and results from reaction (b) are displayed in Table Prev. Table 16.31 preview 16.31 (in PDF or PS). A recent measurement of n-p angular correlations from 14N(3He,

  11. A=16Ne (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (See the Isobar Diagram for 16Ne) GENERAL: See Table Prev. Table 16.29 preview 16.29 [General Table] (in PDF or PS) and Table Prev. Table 16.32 preview 16.32 [Table of Energy Levels] (in PDF or PS). Mass of 16Ne: The Q-values of the 20Ne(α, 8He) and 16O(π+, π-) reactions lead to atomic mass excesses of 23.93 ± 0.08 MeV (1978KE06), 23.978 ± 0.024 MeV (1983WO01) and 24.048 ± 0.045 MeV (1980BU15) [recalculated using the (1985WA02) masses for 8He, 16O and 20Ne]. The weighted mean is

  12. A=17F (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (See Energy Level Diagrams for 17F) GENERAL: See Table Prev. Table 17.22 preview 17.22 [General Table] (in PDF or PS) and Table Prev. Table 17.23 preview 17.23 [Table of Energy Levels] (in PDF or PS). μ = 4.72130 ± 0.00025 n.m. (1992MI13), Q = 0.10 ± 0.02 b (1974MI21). 1. 17F(β+)17O Qm = 2.760 The half-life of 17F is 64.49 ± 0.16 sec; log ft= 3.358 ± 0.002. The log ftvalue for the transition to 17O*(0.87) is > 5.6: see (1982AJ01, 1986AJ04). The β anisotropy has been measured

  13. A=17Ne (1993TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    93TI07) (See the Isobar Diagram for 17Ne) GENERAL: See Table Prev. Table 17.26 preview 17.26 [Table of Energy Levels] (in PDF or PS). 1. (a) 17Ne(β+)17F* → 16O + p Qm = 13.928 (b) 17Ne(β+)17F → 13N + α Qm = 8.711 (c) 17Ne(β+)17F Qm = 14.529 The half-life of 17Ne has been reported as 109.0 ± 1.0 msec (1971HA05) and 109.3 ± 0.6 msec (1988BO39): the weighted mean is 109.2 ± 0.6 and we adopt it. The decay is primarily to the proton unstable states of 17F at 4.65, 5.49, 6.04 and 8.08 MeV

  14. A=18B (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (Not illustrated) 18B has not been observed in the bombardment of Ta by 44 MeV/A Ar ions (1985DE60, 1985LA03, 1986PO13) or in the bombardment of Be by 12 MeV/A 56Fe ions (1984MU27). 18B has been predicted to have a mass excess of 52.3 MeV (1993AU05). It would then be unstable with respect to 17B + n by 0.5 MeV: see (1978AJ03, 1985WA02). 18B is calculated to have Jπ = 4- and to have excited states at 0.62, 0.86 and 1.59 MeV with Jπ = 1-, 2- and 2- (1985PO10).The shell model calculations

  15. A=18F (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (See Energy Level Diagrams for 18F) GENERAL: See Table Prev. Table 18.23 preview 18.23 [General Table] (in PDF or PS) and Table Prev. Table 18.24 preview 18.24 [Table of Energy Levels] (in PDF or PS). μ1.12 = +2.86 ± 0.03 nm [see (1983AJ01)] Q1.12 = 0.13 ± 0.03 b [see (1983AJ01)]. 1. 18F(β+)18O Qm = 1.655 The positron decay is entirely to the ground state of 18O [Jπ = 0+, T = 1]; the half-life is 109.77 ± 0.05 min [see Table Prev. Table 18.11 preview 18.11 (in PDF or PS) in

  16. A=19C (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (See the Isobar Diagram for 19C) 19C has been observed in the 0.8 GeV proton bombardment of thorium (1986VI09, 1988WO09) and in the fragmentation of 66 MeV/A argon ions (1987GI05) and in 44 MeV/A 22Ne on 181Ta, and in 112 MeV/A 20Ne on 12C (1994RAZW, 1995OZ02). The mass excess adopted by (1993AU05) is 32.23 ± 0.11 MeV. See also (1986VI09, 1987GI05, 1988WO09, 1991OR01). 19C is then stable with respect to decay into 18C + n by 0.16 MeV and into 17C + 2n by 4.35 MeV. The half-life was

  17. A=19F (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (See Energy Level Diagrams for 19F) GENERAL: See Table Prev. Table 19.8 preview 19.8 [General Table] (in PDF or PS) and Table Prev. Table 19.9 preview 19.9 [Table of Energy Levels] (in PDF or PS) here. < r2 >1/2 = 2.885 ± 0.015 fm [see (1978AJ03)] μg.s. = +2.628866 (8) nm (1978LEZA) μ0.197 = +3.607 (8) nm (1978LEZA) Q0.197 = -0.12 ± 0.02 b (1978LEZA) 1. 10B(9Be, X) Mass distribution from the sequential decay of the compound nuclei formed from 10B + 9Be and 10B + 10B at Elab/A =

  18. A=19N (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (See the Isobar Diagram for 19N) 19N has been produced in a number of different multinucleon transfer reactions (1983AJ01, 1987AJ02), and these results lead to an adopted value (1993AU05) of 15.860 ± 0.016 MeV for the mass excess. 19N is then stable with respect to decay into 18N + n by 5.33 MeV. The half-life has been measured to be 0.32 ± 0.10 s (1986DU07), 0.21+0.2-0.1 s (1988MU08), 0.235 ± 0.032 s (1988SA04), 0.300 ± 0.080 s (1988DUZT), 0.329 ± 0.019 s (1991RE02). The neutron

  19. A=19Ne (1995TI07)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    95TI07) (See Energy Level Diagrams for 19Ne) GENERAL: See Table Prev. Table 19.26 preview 19.26 [General Table] (in PDF or PS) and Table Prev. Table 19.27 preview 19.27 [Table of Energy Levels] (in PDF or PS) here. μg.s. = -1.88542 (8) nm (1982MA39) μ0.239 = -0.740 (8) nm (1978LEZA) 1. 19Ne(β+)19F Qm = 3.238 We adopt the half-life of 19Ne suggested by (1983AD03): 17.34 ± 0.09 s. See also (1978AJ03). The decay is principally to 19Fg.s.: see Table Prev. Table 19.29 preview 19.29 (in PDF or

  20. A=20Mg (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    98TI06) (See the Isobar Diagram for 20Mg) 20Mg has been populated in the 24Mg(α, 8He) reaction at Eα = 127 and 156 MeV, in the 20Ne(3He, 3n) reaction at E(3He) = 70 MeV, and more recently in projectile fragmentation reactions. Reviews of proton rich nuclei and methods of production are presented in (1989AYZU, 1993SO13). See also (1990PO04). The super-allowed decay of 20Mg to the first T = 2 (Jπ = 0+) state of 20Na [Ex = 6.534 ± 0.013 MeV (1995PI03)] has been reported in early work (1979MO02,

  1. A=20Na (1998TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    98TI06) (See Energy Level Diagrams for 20Na) GENERAL: See Table Prev. Table 20.32 preview 20.32 [General Table] (in PDF or PS) and Table Prev. Table 20.33 preview 20.33 [Table of Energy Levels] (in PDF or PS) here. μ = 0.3694 ± 0.0002 nm (1975SC20, 1989RA17) 1. 20Na(β+)20Ne Qm = 13.887 20Na decays by positron emission to 20Ne*(1.63) and to a number of other excited states of 20Ne: see Table Prev. Table 20.31 preview 20.31 (in PDF or PS) and reaction 59 in 20Ne. The half-life of 20Na is 447.9

  2. A=4H (1992TI02)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    H (1992TI02) (See Energy Level Diagrams for 4H) GENERAL: The stability of the first excited state of 8Li against decay into 4He + 4H (1988AJ01) sets an upper limit for B(4H) ≤ 3.53 MeV (1965BA1A). This also sets a lower limit to the β- decay energy 4H → 4He of 17.06 MeV. The upper limit of the β- decay energy would be 20.60 MeV, if 4H is stable against decay into 3H + n. (1965BA1A) give estimates for the expected half-life of the beta decay: if Jπ(4H) = 0-, 1-, 2-, τ1/2 ≥ 10 min; if

  3. A=4n (1992TI02)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    4n (1992TI02) GENERAL: The stability of 8He (1968BA48, 1968ME03, 1973FI04, 1988AJ01) sets an upper limit to the total binding energy of 4n, because the decay 8He → 4He + 4n does not occur (1964GO1B, 1964GO25). The most precisely determined mass excess of 8He (1988WA18) yields B(4n) ≤ 3.1 MeV. Noting that in all known nuclei the proton binding energy increases when two neutrons are added, (1964VL1A) show that B(4n) < -Q, where Q is the decay energy for 5H → 3H + 2n. Since Q > 0

  4. A=7H (2002TI10)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2002TI10) (Not illustrated) 7H has not been observed. Attempts have been made to detect it in the spontaneous fission of 252Cf (1982AL33) and in the 7Li(π-, π+) reaction [see (1984AJ01)]. A study of 9Be(π-, 2p) (1987GO25) found no evidence for 7H. See also the review of (1989OG1B) and the 7Li(π-, π+) investigation reported in (1989GR06). The ground state is calculated to have Jπ = 1/2+ and to be unstable with respect to 1n, 2n, 3n and 4n emission. Excited states are predicted at 4.84, 5.00

  5. A=8C (2004TI06)

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    2004TI06) (See the Isobar Diagram for 8C) Mass of 8C: The atomic mass excess of 8C is 35094 ± 23 keV (2003AU03); Γcm = 230 ± 50 keV [Jπ = 0+; T = 2]: see (1979AJ01). 8C is stable with respect to 7B + p (Q = -0.07 MeV) and unstable with respect to 6Be + 2p (Q = 2.14), 5Li + 3p (Q = 1.55) and 4He + 4p (Q = 3.51). At E(3He) = 76 MeV the differential cross section for formation of 8Cg.s. in the 14N(3He, 9Li) reaction is ~ 5 nb/sr at θlab = 10°. The 12C(α, 8He)8C reaction has been studied at

  6. Modeling and experimental studies of oxide covered metal surfaces: TiO{sub 2}/Ti a model system. Progress report

    SciTech Connect (OSTI)

    Smyrl, W.H.

    1991-12-31

    Prior work in our laboratories at the Corrosion Research Center has shown that thin, anodic TiO{sub 2} films formed by the Slow Growth Mode (SGM) on polycrystalline titanium and microcrystalline with a texture that varies from one metal grain to another. Furthermore, the underlying metal grains are mapped by the photoelectrochemical response of the oxide. The same characteristics have also been demonstrated in our laboratory for ZnO grown on Zn. The TiO{sub 2}/Ti system has been chosen for study both because of its importance in energy systems, and because it can serve as a model system for other metal-metal oxide couples. The investigations of anodic TiO{sub 2} films on Ti have shown that the properties of thin films are consistent with the rutile form of the oxide. Both experimental data and theoretical calculations show the close resemblance to results on single crystal TiO{sub 2}. Furthermore, the modeling studies reveal that the optical transitions near the bandedge arise from the bulk band structure. The photoelectrochemical properties of anodic TiO{sub 2} films have now been shown to obey the simple Gaertner-Butler model for the semiconductor-electrolyte interface, with a few modifications. The most important deviation has now been shown to be a result of multiple internal reflections in the oxide film.

  7. Modeling and experimental studies of oxide covered metal surfaces: TiO sub 2 /Ti a model system

    SciTech Connect (OSTI)

    Smyrl, W.H.

    1991-01-01

    Prior work in our laboratories at the Corrosion Research Center has shown that thin, anodic TiO{sub 2} films formed by the Slow Growth Mode (SGM) on polycrystalline titanium and microcrystalline with a texture that varies from one metal grain to another. Furthermore, the underlying metal grains are mapped by the photoelectrochemical response of the oxide. The same characteristics have also been demonstrated in our laboratory for ZnO grown on Zn. The TiO{sub 2}/Ti system has been chosen for study both because of its importance in energy systems, and because it can serve as a model system for other metal-metal oxide couples. The investigations of anodic TiO{sub 2} films on Ti have shown that the properties of thin films are consistent with the rutile form of the oxide. Both experimental data and theoretical calculations show the close resemblance to results on single crystal TiO{sub 2}. Furthermore, the modeling studies reveal that the optical transitions near the bandedge arise from the bulk band structure. The photoelectrochemical properties of anodic TiO{sub 2} films have now been shown to obey the simple Gaertner-Butler model for the semiconductor-electrolyte interface, with a few modifications. The most important deviation has now been shown to be a result of multiple internal reflections in the oxide film.

  8. Method and apparatus for maintaining the pH in zinc-bromine battery systems

    DOE Patents [OSTI]

    Grimes, Patrick G.

    1985-09-10

    A method and apparatus for maintaining the pH level in a zinc-bromine battery features reacting decomposition hydrogen with bromine in the presence of a catalyst. The catalyst encourages the formation of hydrogen and bromine ions. The decomposition hydrogen is therefore consumed, alloying the pH of the system to remain substantially at a given value.

  9. Patent: Microfluidic device having an immobilized pH gradient and page gels

    Office of Scientific and Technical Information (OSTI)

    for protein separation and analysis | DOEpatents device having an immobilized pH gradient and page gels for protein separation and analysis Citation Details Title: Microfluidic device having an immobilized pH gradient and page gels for protein separation and analysis

  10. Consideration of factors affecting strip effluent pH and sodium content

    SciTech Connect (OSTI)

    Peters, T. B.

    2015-07-29

    A number of factors were investigated to determine possible reasons for why the Strip Effluent (SE) can sometimes have higher than expected pH values and/or sodium content, both of which have prescribed limits. All of the factors likely have some impact on the pH values and Na content.

  11. TI--CR--AL--O thin film resistors

    DOE Patents [OSTI]

    Jankowski, Alan F. (Livermore, CA); Schmid, Anthony P. (Solana Beach, CA)

    2000-01-01

    Thin films of Ti--Cr--Al--O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti--Cr--Al--O film <1 .mu.m thick. The film resistivity can be discretely selected through control of the target composition and the deposition parameters. The application of Ti--Cr--Al--O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti--Cr--Al--O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

  12. Martensite transformation of epitaxial Ni-Ti films

    SciTech Connect (OSTI)

    Buschbeck, J.; Kozhanov, A.; Kawasaki, J. K.; James, R. D.; Palmstroem, C. J.

    2011-05-09

    The structure and phase transformations of thin Ni-Ti shape memory alloy films grown by molecular beam epitaxy are investigated for compositions from 43 to 56 at. % Ti. Despite the substrate constraint, temperature dependent x-ray diffraction and resistivity measurements reveal reversible, martensitic phase transformations. The results suggest that these occur by an in-plane shear which does not disturb the lattice coherence at interfaces.

  13. A comparative study of precipitation effects in Ti only and Ti-V Ultra Low Carbon (ULC) strip steels

    SciTech Connect (OSTI)

    Ooi, S.W.; Fourlaris, G. . E-mail: g.fourlaris@swansea.ac.uk

    2006-04-15

    Two ULC steel grades were investigated, one based on combined vanadium and titanium additions and the other based on titanium only additions. It has been established that TiC formation during interphase precipitation retards grain growth of the {l_brace}111{r_brace} texture grains during continuous annealing and hence positively affects the r value of the Ti only steel. The formation of newly formed TiC precipitates on dislocations during continuous annealing has been found to result in an increase of the yield strength in both steel grades, as the annealing temperature is increased. It is also confirmed that VC particles formed during the coiling process dissolve during the continuous annealing cycles. Suitable continuous annealing cycles can be adopted to produce high formable steels with a bake hardening potential using the beneficial effects of combined Ti-V additions.

  14. Origin of the instability of octadecylamine Langmuir monolayer at low pH

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Avazbaeva, Zaure; Sung, Woongmo; Lee, Jonggwan; Phan, Minh Dinh; Shin, Kwanwoo; Vaknin, David; Kim, Doseok

    2015-11-30

    In this paper, it has been reported that an octadecylamine (ODA) Langmuir monolayer becomes unstable at low pH values with no measurable surface pressure at around pH 3.5, suggesting significant dissolution of the ODA molecule into the subphase solution (Albrecht, Colloids Surf. A 2006, 284–285, 166–174). However, by lowering the pH further, ODA molecules reoccupy the surface, and a full monolayer is recovered at pH 2.5. Using surface sum-frequency spectroscopy and pressure–area isotherms, it is found that the recovered monolayer at very low pH has a larger area per molecule with many gauche defects in the ODA molecules as comparedmore » to that at high pH values. This structural change suggests that the reappearance of the monolayer is due to the adsorbed Cl– counterions to the protonated amine groups, leading to partial charge neutralization. This proposition is confirmed by intentionally adding monovalent salts (i.e., NaCl, NaBr, or NaI) to the subphase to recover the monolayer at pH 3.5, in which the detailed structure of the monolayer is confirmed by sum frequency spectra and the adsorbed anions by X-ray reflectivity.« less

  15. Photocatalytic activity and stability of TiO{sub 2} and WO{sub 3} thin films

    SciTech Connect (OSTI)

    Carcel, Radu Adrian; Andronic, Luminita Duta, Anca

    2012-08-15

    Photocatalysis represents a viable option for complete degrading the dye molecules resulted in the textile industry, up to products that do not represent environmental threats. The photocatalytic degradation of methyl orange has been investigated using TiO{sub 2}, WO{sub 3} and mixed thin films. The photodegradation efficiency is examined in correlation with the experimental parameters (irradiation time, H{sub 2}O{sub 2} addition and stability), along with the morphology and crystallinity data. The H{sub 2}O{sub 2} addition increases the photodegradation efficiency by providing additional hydroxyl groups and further reducing the recombination of the electron-hole pairs by reacting with the electrons at the catalyst interface. To test the stability of the photocatalytic films in long time running processes, batch series of experiments were conducted using contact periods up to 9 days. The results show that the thin films maintained their photocatalytic properties confirming their stability and viability for up-scaling. Highlights: Black-Right-Pointing-Pointer TiO{sub 2}, WO{sub 3} and mixed thin films Black-Right-Pointing-Pointer We tested the photocatalytic activity and photocatalyst stability over a period up to 9 days of continuous irradiation. Black-Right-Pointing-Pointer The influence of medium pH and oxidizing agent (H{sub 2}O{sub 2}) was analyzed.

  16. T.M. Bull Bennett, PhD | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    T.M. Bull Bennett, PhD About Us T.M. Bull Bennett, PhD T.M. Bull Bennett, PhD Dr. T. M. Bull Bennett (Mi'kmaq), was born in Brunswick, ME, and grew up in the mountains and prairies of Wyoming. As an undergraduate he studied field ecology earning a BS in Biology from Black Hills State University. He completed his MS in Zoology and Physiology at the University of Wyoming where he studied captive propagation of black-footed ferrets (Mustela nigripes) as part of the National Black-Footed Ferret

  17. Magneto-transport in LaTi{sub 1?x}Mn{sub x}O{sub 3}/SrTiO{sub 3} oxide heterostructures

    SciTech Connect (OSTI)

    Kumar, Pramod Dogra, Anjana Budhani, R. C.

    2014-04-24

    We report the growth of ultrathin film of Mn doped LaTiO{sub 3} on TiO{sub 2} terminated SrTiO{sub 3} (001) substrate by pulsed laser deposition (PLD) and their electrical transport characteristics including magnetoresistance (MR). Though the replacement of Mn in LaTiO{sub 3} at the Ti site in dilute limit does not affect the metallic behaviour of films but variation in resistance is observed. Normalised resistance behaviour is explained on the basis of variation in charge carriers and increased interaction between Mn atoms in the system under investigation.

  18. ORISE report shows number of health physics Ph.D.s declined in...

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ORISE report shows number of health physics Ph.D.s declined in 2009 FOR IMMEDIATE RELEASE June 15, 2010 FY10-37 OAK RIDGE, Tenn.-Health physics undergraduate degrees increased...

  19. WBU-14-0011- In the Matter of Dr. Paul M. Cole, Ph.D

    Broader source: Energy.gov [DOE]

    On November 3, 2014, the Office of Hearings and Appeals (OHA) issued a decision denying a jurisdictional appeal filed by Dr. Paul M. Cole, Ph.D (Dr. Cole), a former Oak Ridge Institute for Science...

  20. Final Report: Support for Polytechnic PhD Student, September 24, 1996 - June 30, 1999

    SciTech Connect (OSTI)

    Myerson, Allan S.

    2000-01-19

    Polytechnic University PhD student working on research projects in the area of fossil energy and renewable energy were supported in this program and did their research work at Brookhaven National Laboratory in the Department of Applied Sciences. One of these students had completed an MS degree in Chemical Engineering at Howard University while doing his research at Brookhaven. This student continued his studies by becoming a Polytechnic PhD student while doing his research work at Brookhaven.

  1. pH effect on the separation of uranium fluoride effluents by the reverse osmosis process

    SciTech Connect (OSTI)

    Yun Chen ); Min-Lin Chu; Mu-Chang Shieh , Lung-tan, )

    1992-04-01

    Ammonium fluoride solutions and uranium fluoride effluents (UFE) with solute concentrations from 0.101 to 7,920 kg/m{sup 3}, at pH 2.80 to 9.60, have been treated with a continuous feedback reverse osmosis (RO) process. The solute rejections of NH{sub 4}{sup +}, F{sup {minus}}, and U{sup 6+} depend heavily on the feed pH value. For ammonium fluoride solutions, the rejection ratio of NH{sub 4}{sup +} decreases sharply from ca. 90 to 44.2% with the feed pH increased from 3.30 to 9.60, while that of F{sup {minus}} increases abruptly from 44.8 to 99.9% at the same pH change. For UFE solutions, the rejection ratio of U{sup 6+} remains greater than 90% at pH 2.80-7.13, while that of F{sup {minus}} decreases steadily from 96.4 to 18.8% with decreasing feed pH. Accordingly, the fluoride ions can be separated from UFE solutions under acidic conditions. The changes of solute rejection with feed pH can be explained by the different solubilities of the solutes in the membrane at different pH values. The UFE solutions with {alpha} and {beta} activities at 20.4-53.7 and 8.99-21.3 ({times} 10{sup 5} Baq/m{sup 3}) can be reduced to a level lower than 2.41 and 3.37 ({times}10{sup 5} Baq/m{sup 3}), respectively, by the current RO process.

  2. Theory of signal and noise in double-gated nanoscale electronic pH sensors

    SciTech Connect (OSTI)

    Go, Jonghyun; Nair, Pradeep R.; Alam, Muhammad A.

    2012-08-01

    The maximum sensitivity of classical nanowire (NW)-based pH sensors is defined by the Nernst limit of 59 mV/pH. For typical noise levels in ultra-small single-gated nanowire sensors, the signal-to-noise ratio is often not sufficient to resolve pH changes necessary for a broad range of applications. Recently, a new class of double-gated devices was demonstrated to offer apparent 'super-Nernstian' response (>59 mV/pH) by amplifying the original pH signal through innovative biasing schemes. However, the pH-sensitivity of these nanoscale devices as a function of biasing configurations, number of electrodes, and signal-to-noise ratio (SNR) remains poorly understood. Even the basic question such as 'Do double-gated sensors actually resolve smaller changes in pH compared to conventional single-gated sensors in the presence of various sources of noise?' remains unanswered. In this article, we provide a comprehensive numerical and analytical theory of signal and noise of double-gated pH sensors to conclude that, while the theoretical lower limit of pH-resolution does not improve for double-gated sensors, this new class of sensors does improve the (instrument-limited) pH resolution.

  3. Stability of Y Ti O Precipitates in Friction Stir Welded Nanostructure...

    Office of Scientific and Technical Information (OSTI)

    Stability of Y Ti O Precipitates in Friction Stir Welded Nanostructured Ferritic Alloys Citation Details In-Document Search Title: Stability of Y Ti O Precipitates in Friction Stir...

  4. Shape-memory transformations of NiTi: Minimum-energy pathways...

    Office of Scientific and Technical Information (OSTI)

    Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, ... Citation Details In-Document Search Title: Shape-memory transformations of NiTi: ...

  5. FIRST-PRINCIPLES PHASE STABILITY IN THE TI-V ALLOY SYSTEM (Journal...

    Office of Scientific and Technical Information (OSTI)

    FIRST-PRINCIPLES PHASE STABILITY IN THE TI-V ALLOY SYSTEM Citation Details In-Document Search Title: FIRST-PRINCIPLES PHASE STABILITY IN THE TI-V ALLOY SYSTEM You are accessing...

  6. Conversion of 1,3-Propylene Glycol on Rutile TiO2(110) (Journal...

    Office of Scientific and Technical Information (OSTI)

    Conversion of 1,3-Propylene Glycol on Rutile TiO2(110) Citation Details In-Document Search Title: Conversion of 1,3-Propylene Glycol on Rutile TiO2(110) The adsorption of...

  7. High-Ti-concentration aerogels for bright x-ray sources (Technical...

    Office of Scientific and Technical Information (OSTI)

    Ti-concentration aerogels for bright x-ray sources Citation Details In-Document Search Title: High-Ti-concentration aerogels for bright x-ray sources Authors: Perez, F ; Patterson,...

  8. High-Ti-concentration aerogels for bright x-ray sources (Technical...

    Office of Scientific and Technical Information (OSTI)

    Ti-concentration aerogels for bright x-ray sources Citation Details In-Document Search Title: High-Ti-concentration aerogels for bright x-ray sources You are accessing a...

  9. Coating power RF components with TiN

    SciTech Connect (OSTI)

    Kuchnir, M.; Hahn, E.

    1995-03-01

    A facility for coating RF power components with thin films of Ti and/or TiN has been in operation for some time at Fermilab supporting the Accelerator Division RF development work and the TESLA program. It has been experimentally verified that such coatings improve the performance of these components as far as withstanding higher electric fields. This is attributed to a reduction in the secondary electron emission coefficient of the surfaces when coated with a thin film containing titanium. The purpose of this Technical Memorandum is to describe the facility and the procedure used.

  10. High strength, light weight Ti-Y composites and method of making same

    DOE Patents [OSTI]

    Verhoeven, J.D.; Ellis, T.W.; Russell, A.M.; Jones, L.L.

    1993-04-06

    A high strength, light weight in-situ'' Ti-Y composite is produced by deformation processing a cast body having Ti and Y phase components distributed therein. The composite comprises elongated, ribbon-shaped Ti and Y phase components aligned along an axis of the deformed body.

  11. High strength, light weight Ti-Y composites and method of making same

    DOE Patents [OSTI]

    Verhoeven, John D. (Ames, IA); Ellis, Timothy W. (Ames, IA); Russell, Alan M. (Ames, IA); Jones, Lawrence L. (Ames, IA)

    1993-04-06

    A high strength, light weight "in-situ" Ti-Y composite is produced by deformation processing a cast body having Ti and Y phase components distributed therein. The composite comprises elongated, ribbon-shaped Ti and Y phase components aligned along an axis of the deformed body.

  12. Influence of acidic pH on hydrogen and acetate production by an electrosynthetic microbiome

    SciTech Connect (OSTI)

    LaBelle, Edward V.; Marshall, Christopher W.; Gilbert, Jack A.; May, Harold D.; Battista, John R.

    2014-10-15

    Production of hydrogen and organic compounds by an electrosynthetic microbiome using electrodes and carbon dioxide as sole electron donor and carbon source, respectively, was examined after exposure to acidic pH (~5). Hydrogen production by biocathodes poised at -600 mV vs. SHE increased>100-fold and acetate production ceased at acidic pH, but ~5–15 mM (catholyte volume)/day acetate and>1,000 mM/day hydrogen were attained at pH ~6.5 following repeated exposure to acidic pH. Cyclic voltammetry revealed a 250 mV decrease in hydrogen overpotential and a maximum current density of 12.2 mA/cm2 at -765 mV (0.065 mA/cm2 sterile control at -800 mV) by the Acetobacterium-dominated community. Supplying -800 mV to the microbiome after repeated exposure to acidic pH resulted in up to 2.6 kg/m3/day hydrogen (≈2.6 gallons gasoline equivalent), 0.7 kg/m3/day formate, and 3.1 kg/m3/day acetate ( = 4.7 kg CO2 captured).

  13. pH control of the structure, composition, and catalytic activity of sulfated zirconia

    SciTech Connect (OSTI)

    Ivanov, Vladimir K.; Materials Science Department, Moscow State University, Moscow 119991 ; Baranchikov, Alexander Ye.; Kopitsa, Gennady P.; Lermontov, Sergey A.; Yurkova, Lyudmila L.; Gubanova, Nadezhda N.; Petersburg Nuclear Physics Institute, Orlova Roscha, Gatchina 188300 ; Ivanova, Olga S.; Lermontov, Anatoly S.; Rumyantseva, Marina N.; Vasilyeva, Larisa P.; Sharp, Melissa; Pranzas, P. Klaus; Tretyakov, Yuri D.

    2013-02-15

    We report a detailed study of structural and chemical transformations of amorphous hydrous zirconia into sulfated zirconia-based superacid catalysts. Precipitation pH is shown to be the key factor governing structure, composition and properties of amorphous sulfated zirconia gels and nanocrystalline sulfated zirconia. Increase in precipitation pH leads to substantial increase of surface fractal dimension (up to {approx}2.7) of amorphous sulfated zirconia gels, and consequently to increase in specific surface area (up to {approx}80 m{sup 2}/g) and simultaneously to decrease in sulfate content and total acidity of zirconia catalysts. Complete conversion of hexene-1 over as synthesized sulfated zirconia catalysts was observed even under ambient conditions. - Graphical abstract: Surface fractal dimension of amorphous sulfated zirconia and specific surface area and catalytic activity of crystalline sulfated zirconia as a function of precipitation pH. Highlights: Black-Right-Pointing-Pointer Structural transformation of amorphous hydrous zirconia into sulfated zirconia is studied. Black-Right-Pointing-Pointer Precipitation pH controls surface fractal dimension of amorphous zirconia gels. Black-Right-Pointing-Pointer Precipitation pH is the key factor governing properties of sulfated zirconia.

  14. Hysteretic electrical transport in BaTiO{sub 3}/Ba{sub 1?x}Sr{sub x}TiO{sub 3}/Ge heterostructures

    SciTech Connect (OSTI)

    Ngai, J. H.; Kumah, D. P.; Walker, F. J.; Ahn, C. H.

    2014-02-10

    We present electrical transport measurements of heterostructures comprised of BaTiO{sub 3} and Ba{sub 1?x}Sr{sub x}TiO{sub 3} epitaxially grown on Ge. Sr alloying imparts compressive strain to the BaTiO{sub 3}, which enables the thermal expansion mismatch between BaTiO{sub 3} and Ge to be overcome to achieve c-axis oriented growth. The conduction bands of BaTiO{sub 3} and Ba{sub 1?x}Sr{sub x}TiO{sub 3} are nearly aligned with the conduction band of Ge, which facilitates electron transport. Electrical transport measurements through the dielectric stack exhibit rectifying behavior and hysteresis, where the latter is consistent with ferroelectric switching.

  15. Influence of pH on the quantum-size-controlled photoelectrochemical etching

    Office of Scientific and Technical Information (OSTI)

    of epitaxial InGaN quantum dots (Journal Article) | SciTech Connect Influence of pH on the quantum-size-controlled photoelectrochemical etching of epitaxial InGaN quantum dots Citation Details In-Document Search This content will become publicly available on November 18, 2016 Title: Influence of pH on the quantum-size-controlled photoelectrochemical etching of epitaxial InGaN quantum dots Illumination by a narrow-band laser has been shown to enable photoelectrochemical (PEC) etching of InGaN

  16. Gating of the proton-gated ion channel from Gloeobacter violaceus at pH 4

    Office of Scientific and Technical Information (OSTI)

    as revealed by X-ray crystallography (Journal Article) | SciTech Connect Journal Article: Gating of the proton-gated ion channel from Gloeobacter violaceus at pH 4 as revealed by X-ray crystallography Citation Details In-Document Search Title: Gating of the proton-gated ion channel from Gloeobacter violaceus at pH 4 as revealed by X-ray crystallography Authors: Gonzalez-Gutierrez, Giovanni ; Cuello, Luis G. ; Nair, Satish K. ; Grosman, Claudio [1] ; TTU) [2] + Show Author Affiliations UIUC (

  17. Microfluidic device having an immobilized pH gradient and page gels for

    Office of Scientific and Technical Information (OSTI)

    protein separation and analysis (Patent) | SciTech Connect device having an immobilized pH gradient and page gels for protein separation and analysis Citation Details In-Document Search Title: Microfluidic device having an immobilized pH gradient and page gels for protein separation and analysis × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a

  18. PH adjustment of power plant cooling water with flue gas/fly ash

    DOE Patents [OSTI]

    Brady, Patrick V.; Krumhansl, James L.

    2015-09-22

    A system including a vessel including a heat source and a flue; a turbine; a condenser; a fluid conduit circuit disposed between the vessel, the turbine and the condenser; and a diverter coupled to the flue to direct a portion of an exhaust from the flue to contact with a cooling medium for the condenser water. A method including diverting a portion of exhaust from a flue of a vessel; modifying the pH of a cooling medium for a condenser with the portion of exhaust; and condensing heated fluid from the vessel with the pH modified cooling medium.

  19. Adhesion evaluation of TiN and (Ti, Al)N coatings on titanium 6Al-4V

    SciTech Connect (OSTI)

    James, R.D.; Gruss, K.A.; Horie, Y.; Davis, R.F.; Paisley, D.L.; Parthasarthi, S.; Tittmann, B.R.

    1996-12-31

    The metallic components of gas turbine engines are continually subjected to hostile atmospheres. Nitride coatings improve the performance of the metallic compressor blades in these engines. To assess the adhesion of nitride coatings on metals, titanium 6% aluminum 4% vanadium substrates were coated with titanium nitride (TiN) using both cathodic arc and electron beam evaporation. Titanium aluminum nitride ((Ti, Al)N) was also deposited using cathodic arc evaporation. The interfaces of the coated samples were loaded in tension using a high speed shock wave which caused spallation either at the interface, in the coating or in the metal. Scanning acoustic microscopy analysis of the spalled samples detected delaminations at the interface in the samples deposited by cathodic arc evaporation. DYNA2D modeling of plate impact spallation experiments revealed the tensile adhesion strength for TiN deposited by both techniques was {approx} 2.0 GPa. The tensile adhesion strength for (Ti, Al)N was less than 1.5 GPa.

  20. Dissolved oxygen and pH relationships in northern Australian mangrove waterways

    SciTech Connect (OSTI)

    Boto, K.G.; Bunt, J.S.

    1981-01-01

    Consistent, highly significant linear correlations (R2 greater than or equal to 0.8) between pH and dissolved oxygen levels have been found in northern Australian mangrove waterways. These properties seem to be influenced by dissolved organic matter, mainly polyphenolic compounds, present in the creeks and tidal channel waters.

  1. Adsorption behavior of copper and zinc in soils: Influence of pH on adsorption characteristics

    SciTech Connect (OSTI)

    Msaky, J.J. ); Calvet, R. )

    1990-08-01

    The authors studied adsorption of copper and zinc on three different soils: a brown silty soil, an Oxisol, and a Podzol. They determined the amounts adsorbed and the shapes of adsorption isotherms as a function of the pH of the adsorbing medium at a constant ionic strength. The adsorbed amount-pH relationship depended strongly on the natures of the metallic cation and of the soil. The pH greatly influenced the characteristics of adsorption isotherms. They based interpretation on the variations with the pH of both adsorbent affinity for the metal in relation to the surface electric charge and chemical speciation in solution. The adsorption mechanism in the Oxisol probably involves monohydroxylated cations but is more determined by bivalent cations in the brown silty soil and the Podzol. From a general point of view, adsorption of copper and zinc cannot be represented with a single adsorption constant, but should be described by adsorption isotherms obtained at various pH values.

  2. Aqueous biphasic extraction process with pH and particle control

    DOE Patents [OSTI]

    Chaiko, David J. (Woodridge, IL); Mensah-Biney, R. (Downers Grove, IL)

    1995-01-01

    A process for aqueous biphasic extraction of metallic oxides and the like from substances containing silica. Control of media pH enables efficient and effective partition of mixture components. The inventive method may be employed to remove excess silica from kaolin clay.

  3. Aqueous biphasic extraction process with pH and particle control

    DOE Patents [OSTI]

    Chaiko, D.J.; Mensah-Biney, R.

    1995-05-02

    A process for aqueous biphasic extraction of metallic oxides and the like from substances containing silica. Control of media pH enables efficient and effective partition of mixture components. The inventive method may be employed to remove excess silica from kaolin clay. 2 figs.

  4. Recent Ph.D. Recipients Sought for Innovative Research in Solar Energy

    Broader source: Energy.gov [DOE]

    EERE’s SunShot Initiative is now accepting applications from recent Ph.D. graduates for postdoctoral research awards in solar energy. As part of the EERE Postdoctoral Research Award Program, up to five doctoral graduates will be offered a $65,000 stipend, plus the chance to do applied research, advancing solar energy technologies.

  5. Dual Phase Li4 Ti5O12TiO2 Nanowire Arrays As Integrated Anodes For High-rate Lithium-ion Batteries

    SciTech Connect (OSTI)

    Liao, Jin; Chabot, Victor; Gu, Meng; Wang, Chong M.; Xiao, Xingcheng; Chen, Zhongwei

    2014-08-19

    Lithium titanate (Li4Ti5O12) is well known as a zero strain material inherently, which provides excellent long cycle stability as a negative electrode for lithium ion batteries. However, the low specific capacity (175 mA h g?1) limits it to power batteries although the low electrical conductivity is another intrinsic issue need to be solved. In this work, we developed a facile hydrothermal and ion-exchange route to synthesize the self-supported dual-phase Li4Ti5O12TiO2 nanowire arrays to further improve its capacity as well as rate capability. The ratio of Li4Ti5O12 to TiO2 in the dual phase Li4Ti5O12TiO2 nanowire is around 2:1. The introduction of TiO2 into Li4Ti5O12 increases the specific capacity. More importantly, by interface design, it creates a dual-phase nanostructure with high grain boundary density that facilitates both electron and Li ion transport. Compared with phase-pure nanowire Li4Ti5O12 and TiO2 nanaowire arrays, the dual-phase nanowire electrode yielded superior rate capability (135.5 at 5 C, 129.4 at 10 C, 120.2 at 20 C and 115.5 mA h g?1 at 30 C). In-situ transmission electron microscope clearly shows the near zero deformation of the dual phase structure, which explains its excellent cycle stability.

  6. Synthesis of visible light-activated TiO{sub 2} photocatalyst via surface organic modification

    SciTech Connect (OSTI)

    Jiang Dong Xu Yao Hou Bo; Wu Dong; Sun Yuhan

    2007-05-15

    A visible light-activated TiO{sub 2} photocatalyst was successfully synthesized by the surface organic modification to sol-gel-hydrothermal synthesized TiO{sub 2}. The surface hydroxyls of TiO{sub 2} nanoparticles reacted with the active -NCO groups of tolylene diisocyanate (TDI) to form a surface complex that was confirmed by the FT-IR and XPS spectra. Due to the existence of surface complex, the absorption edge of as-prepared TDI-modified TiO{sub 2} nanomaterial extended well into visible region. Compared with unmodified TiO{sub 2} and Degussa P25, the TDI-modified TiO{sub 2} photocatalysts showed higher activity for the photocatalytic degradation of methylene blue under visible light irradiation. - Graphical abstract: A visible light-activated TiO{sub 2} photocatalyst was successfully synthesized by the surface organic modification to TiO{sub 2}. The surface hydroxyls of TiO{sub 2} nanoparticles reacted with the active -NCO groups of tolylene diisocyanate (TDI) to form a surface complex. The TDI-modified TiO{sub 2} photocatalysts showed higher activity for the photocatalytic degradation of methylene blue under visible light irradiation.

  7. Structural and chemical characterization of BaTiO{sub 3} nanorods

    SciTech Connect (OSTI)

    Zagar, K.; Recnik, A.; Sturm, S.; Gajovic, A.; Ceh, M.

    2011-03-15

    Research highlights: {yields} Polycrystalline BaTiO{sub 3} nanorods were synthesized with EPD into AAO templates. {yields} Nanorods are composed of crystalline, nanosized grains with pseudo-cubic structure. {yields} Integrowth of hexagonal BaTiO{sub 3} polymorph within pseudo-cubic structure was observed. -- Abstract: An electron-microscopy investigation was performed on BaTiO{sub 3} nanorods that were processed by sol-gel electrophoretic deposition (EPD) into anodic aluminium oxide (AAO) membranes. The BaTiO{sub 3} nanorods grown within the template membranes had diameters ranging from 150 to 200 nm, with an average length of 10-50 {mu}m. By using various electron-microscopy techniques we showed that the processed BaTiO{sub 3} nanorods were homogeneous in their chemical composition. The BaTiO{sub 3} nanorods were always polycrystalline and were composed of well-crystallized, defect-free, pseudo-cubic BaTiO{sub 3} grains, ranging from 10 to 30 nm. No intergranular phases were observed between the BaTiO{sub 3} grains. A low-temperature hexagonal polymorph that is coherently intergrown with the BaTiO{sub 3} perovskite matrix was also observed as a minor phase. When annealing the AAO templates containing the BaTiO{sub 3} sol in an oxygen atmosphere the presence of the hexagonal polymorph was diminished.

  8. The Effect of Ramp Rate on the C49 to C54 Titanium Disilicide Phase Transformation from Ti and Ti(Ta)

    SciTech Connect (OSTI)

    BAILEY, GLENN A.; HU, YAO ZHI; SMITH, PAUL M.; TAY, SING PIN

    1999-09-22

    The C49 to C54 TiSi{sub 2} transformation temperature is shown to be reduced by increasing the ramp rate during rapid thermal processing and this effect is more pronounced for thinner initial Ti and Ti(Ta) films. Experiments were performed on blanket wafers and on wafers that had patterned polycrystalline Si lines with Si{sub 3}N{sub 4} sidewall spacers. Changing the ramp rate caused no change in the transformation temperature for 60 nm blanket Ti films. For blanket Ti films of 25 or 40 nm, however, increasing the ramp rate from 7 to 180 C/s decreased the transformation temperature by 15 C. Studies of patterned lines indicate that sheet resistance of narrow lines is reduced by increased ramp rates for both Ti and Ti(Ta) films, especially as the linewidths decrease below 0.4 {micro}m. This improvement is particularly pronounced for the thinnest Ti(Ta) films, which exhibited almost no linewidth effect after being annealed with a ramp rate of 75 C/s.

  9. Ti{sub 5}O{sub 5} superstructures of cubic titanium monoxide

    SciTech Connect (OSTI)

    Gusev, A. I.

    2013-08-15

    A cubic model is proposed for the Ti{sub 5}O{sub 5} (Ti{sub 5} Black-Small-Square O{sub 5}{open_square} {identical_to} Ti{sub 90} Black-Small-Square {sub 18}O{sub 90}{open_square}{sub 18}) superstructure of nonstoichiometric titanium monoxide Ti{sub x}O{sub z} with double imperfection. The unit cell of the cubic Ti{sub 5}O{sub 5} superstructure has the threefold lattice parameter of the unit cell of the basis disordered B1 structure of Ti{sub x}O{sub z} monoxide and belongs to space group Pm 3-bar m . The channel of the disorder-order transition, i.e., Ti{sub x}O{sub z} (space group Fm 3-bar m)-Ti{sub 5}O{sub 5} (space group Pm 3-bar m), includes 75 superstructure vectors of seven stars (k{sub 10}), (k{sub 7}), (k{sub 6(1)}), (k{sub 6(2)}), (k{sub 4(1)}), (k{sub 4(2)}), and (k{sub 1}). The distribution functions of Ti and O atoms over the sites of the cubic Ti{sub 5}O{sub 5} superstructure are calculated. A comparison of the X-ray and electron diffraction data obtained for ordered TiO{sub 1.087} monoxide with the theoretical simulation results supports the existence of the cubic Ti{sub 5}O{sub 5} superstructure. The cubic (space group Pm 3-bar m) Ti{sub 5}O{sub 5} superstructure is shown to be a high-temperature structure relative to the well-known monoclinic (space group C2/m) superstructure of the same type.

  10. Nature of Transactions (TI) Code | National Nuclear Security Administration

    National Nuclear Security Administration (NNSA)

    Nature of Transactions (TI) Code | National Nuclear Security Administration Facebook Twitter Youtube Flickr RSS People Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Countering Nuclear Terrorism About Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Library Bios Congressional Testimony Fact Sheets Newsletters Press Releases Photo Gallery Jobs Apply for Our Jobs Our Jobs

  11. Method of determining pH by the alkaline absorption of carbon dioxide

    DOE Patents [OSTI]

    Hobbs, David T. (1867 Lodgepole Ave., N. Augusta, SC 29841)

    1992-01-01

    A method for measuring the concentration of hydroxides in alkaline solutions in a remote location using the tendency of hydroxides to absorb carbon dioxide. The method includes the passing of carbon dioxide over the surface of an alkaline solution in a remote tank before and after measurements of the carbon dioxide solution. A comparison of the measurements yields the absorption fraction from which the hydroxide concentration can be calculated using a correlation of hydroxide or pH to absorption fraction.

  12. A Literature Survey Kathleen C. Pugh, Ph.D. Waste Management and Remediation

    Office of Scientific and Technical Information (OSTI)

    Toxicity and Physical Properties of Atrazine and its Degradation Products: A Literature Survey Kathleen C. Pugh, Ph.D. Waste Management and Remediation Environmental Research Center Muscle Shoals, Alabama DECLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, express or implied, or assumes any legal liabiiity or responsibility for

  13. pH Adjustment of Power Plant Cooling Water with Flue Gas/ Fly Ash - Energy

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Innovation Portal Advanced Materials Advanced Materials Find More Like This Return to Search pH Adjustment of Power Plant Cooling Water with Flue Gas/ Fly Ash Sandia National Laboratories Contact SNL About This Technology Publications: PDF Document Publication Market Sheet (801 KB) Technology Marketing SummaryIncreased recycling of power plant cooling water calls for low-cost means of preventing the formation of calcium carbonate and silicate scale. Hardness (Ca and Mg) and silica are two of

  14. Ronald D. Ripple, PhD Mervin Bovaird Professor of Energy Business and Finance

    Gasoline and Diesel Fuel Update (EIA)

    natural gas markets: Prospects for US exports? Ronald D. Ripple, PhD Mervin Bovaird Professor of Energy Business and Finance The University of Tulsa, USA 2015 EIA Energy Conference Washington, D.C. June 15-16, 2015 Outline 2 ! Global natural gas ! How has the past year affected projections of global natural gas markets? ! Effects of lower prices " Will lower prices affect Australia's LNG exports? " Will lower prices affect US export opportunities? ! Shipping cost differentials ! Japan

  15. Dr. David Snyder, Ph.D. Archaeology Reviews Manager Ohio Historic Preservation Office

    Office of Environmental Management (EM)

    Snyder, Ph.D. Archaeology Reviews Manager Ohio Historic Preservation Office 1982 Velma Avenue Columbus, Ohio 43211 Dear Dr. Snyder: Department of Energy Portsmouth/Paducah Project Office 1017 Majestic Drive, Suite 200 Lexington, Kentucky 40513 (859) 219-4000 OCT 1 1 2011 PPPO-03-1265954-11 SUBMITTAL OF A REPORT REGARDING PREHISTORIC NATIVE AMERICAN EARTHWORKS AND MOUND SITES IN THE AREA OF THE PORTSMOUTH GASEOUS DIFFUSION PLANT IN SCIOTO AND SEAL TOWNSHIPS, PIKETON, OHIO Enclosed please find a

  16. Photoemission study of the electronic structure and charge density waves of Na?Ti?Sb?O

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Tan, S. Y.; Jiang, J.; Ye, Z. R.; Niu, X. H.; Song, Y.; Zhang, C. L.; Dai, P. C.; Xie, B. P.; Lai, X. C.; Feng, D. L.

    2015-04-30

    The electronic structure of Na?Ti?Sb?O single crystal is studied by photon energy and polarization dependent angle-resolved photoemission spectroscopy (ARPES). The obtained band structure and Fermi surface agree well with the band structure calculation of Na?Ti?Sb?O in the non-magnetic state, which indicates that there is no magnetic order in Na?Ti?Sb?O and the electronic correlation is weak. Polarization dependent ARPES results suggest the multi-band and multi-orbital nature of Na?Ti?Sb?O. Photon energy dependent ARPES results suggest that the electronic structure of Na?Ti?Sb?O is rather two-dimensional. Moreover, we find a density wave energy gap forms below the transition temperature and reaches 65 meV atmore7 K, indicating that Na?Ti?Sb?O is likely a weakly correlated CDW material in the strong electron-phonon interaction regime. (author)less

  17. Photoemission study of the electronic structure and charge density waves of Na?Ti?Sb?O

    SciTech Connect (OSTI)

    Tan, S. Y.; Jiang, J.; Ye, Z. R.; Niu, X. H.; Song, Y.; Zhang, C. L.; Dai, P. C.; Xie, B. P.; Lai, X. C.; Feng, D. L.

    2015-04-30

    The electronic structure of Na?Ti?Sb?O single crystal is studied by photon energy and polarization dependent angle-resolved photoemission spectroscopy (ARPES). The obtained band structure and Fermi surface agree well with the band structure calculation of Na?Ti?Sb?O in the non-magnetic state, which indicates that there is no magnetic order in Na?Ti?Sb?O and the electronic correlation is weak. Polarization dependent ARPES results suggest the multi-band and multi-orbital nature of Na?Ti?Sb?O. Photon energy dependent ARPES results suggest that the electronic structure of Na?Ti?Sb?O is rather two-dimensional. Moreover, we find a density wave energy gap forms below the transition temperature and reaches 65 meV at 7 K, indicating that Na?Ti?Sb?O is likely a weakly correlated CDW material in the strong electron-phonon interaction regime. (author)

  18. LaTiO₃/KTaO₃ interfaces: A new two-dimensional electron gas system

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Zou, K.; Ismail-Beigi, Sohrab; Kisslinger, Kim; Shen, Xuan; Su, Dong; Walker, F. J.; Ahn, C. H.

    2015-03-01

    We report a new 2D electron gas (2DEG) system at the interface between a Mott insulator, LaTiO₃, and a band insulator, KTaO₃. For LaTiO₃/KTaO₃ interfaces, we observe metallic conduction from 2 K to 300 K. One serious technological limitation of SrTiO₃-based conducting oxide interfaces for electronics applications is the relatively low carrier mobility (0.5-10 cm²/V s) of SrTiO₃ at room temperature. By using KTaO₃, we achieve mobilities in LaTiO₃/KTaO₃ interfaces as high as 21 cm²/V s at room temperature, over a factor of 3 higher than observed in doped bulk SrTiO₃. By density functional theory, we attribute the higher mobilitymore » in KTaO₃ 2DEGs to the smaller effective mass for electrons in KTaO₃.« less

  19. Diamond formation due to a pH drop during fluid–rock interactions

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Sverjensky, Dimitri A.; Huang, Fang

    2015-11-03

    Diamond formation has typically been attributed to redox reactions during precipitation from fluids or magmas. Either the oxidation of methane or the reduction of carbon dioxide has been suggested, based on simplistic models of deep fluids consisting of mixtures of dissolved neutral gas molecules without consideration of aqueous ions. The role of pH changes associated with water–silicate rock interactions during diamond formation is unknown. Here we show that diamonds could form due to a drop in pH during water–rock interactions. We use a recent theoretical model of deep fluids that includes ions, to show that fluid can react irreversibly withmore » eclogite at 900 °C and 5.0 GPa, generating diamond and secondary minerals due to a decrease in pH at almost constant oxygen fugacity. Overall, our results constitute a new quantitative theory of diamond formation as a consequence of the reaction of deep fluids with the rock types that they encounter during migration. Diamond can form in the deep Earth during water–rock interactions without changes in oxidation state.« less

  20. Synthesis and new structure shaping mechanism of silica particles formed at high pH

    SciTech Connect (OSTI)

    Zhang, Henan; Zhao, Yu; Akins, Daniel L.

    2012-10-15

    For the sol-gel synthesis of silica particles under high pH catalytic conditions (pH>12) in water/ethanol solvent, we have deduced that the competing dynamics of chemical etching and sol-gel process can explain the types of silica particles formed and their morphologies. We have demonstrated that emulsion droplets that are generated by adding tetraethyl orthosilicate (TEOS) to a water-ethanol solution serve as soft templates for hollow spherical silica (1-2 {mu}m). And if the emulsion is converted by the sol-gel process, one finds that suspended solid silica spheres of diameter of {approx}900 nm are formed. Moreover, several other factors are found to play fundamental roles in determining the final morphologies of silica particles, such as by variation of the pH (in our case, using OH{sup -}) to a level where condensation dominates; by changing the volume ratios of water/ethanol; and using an emulsifier (specifically, CTAB) - Graphical abstract: 'Local chemical etching' and sol-gel process have been proposed to interpret the control of morphologies of silica particles through varying initial pHs in syntheses. Highlights: Black-Right-Pointing-Pointer Different initial pHs in our syntheses provides morphological control of silica particles. Black-Right-Pointing-Pointer 'Local chemical etching' and sol-gel process describes the formation of silica spheres. Black-Right-Pointing-Pointer The formation of emulsions generates hollow silica particles.

  1. Diamond formation due to a pH drop during fluid–rock interactions

    SciTech Connect (OSTI)

    Sverjensky, Dimitri A.; Huang, Fang

    2015-11-03

    Diamond formation has typically been attributed to redox reactions during precipitation from fluids or magmas. Either the oxidation of methane or the reduction of carbon dioxide has been suggested, based on simplistic models of deep fluids consisting of mixtures of dissolved neutral gas molecules without consideration of aqueous ions. The role of pH changes associated with water–silicate rock interactions during diamond formation is unknown. Here we show that diamonds could form due to a drop in pH during water–rock interactions. We use a recent theoretical model of deep fluids that includes ions, to show that fluid can react irreversibly with eclogite at 900 °C and 5.0 GPa, generating diamond and secondary minerals due to a decrease in pH at almost constant oxygen fugacity. Overall, our results constitute a new quantitative theory of diamond formation as a consequence of the reaction of deep fluids with the rock types that they encounter during migration. Diamond can form in the deep Earth during water–rock interactions without changes in oxidation state.

  2. Anisotropic swelling and microcracking of neutron irradiated Ti3AlC2-Ti5Al2C3 materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Ang, Caen K.; Silva, Chinthaka M.; Shih, Chunghao Phillip; Koyanagi, Takaaki; Katoh, Yutai; Zinkle, Steven J.

    2015-12-17

    Mn + 1AXn (MAX) phase materials based on Ti–Al–C have been irradiated at 400 °C (673 K) with fission neutrons to a fluence of 2 × 1025 n/m2 (E > 0.1 MeV), corresponding to ~ 2 displacements per atom (dpa). We report preliminary results of microcracking in the Al-containing MAX phase, which contained the phases Ti3AlC2 and Ti5Al2C3. Equibiaxial ring-on-ring tests of irradiated coupons showed that samples retained 10% of pre-irradiated strength. Volumetric swelling of up to 4% was observed. Phase analysis and microscopy suggest that anisotropic lattice parameter swelling caused microcracking. Lastly, variants of titanium aluminum carbide may bemore » unsuitable materials for irradiation at light water reactor-relevant temperatures.« less

  3. Heterojunction band offsets and dipole formation at BaTiO{sub 3}/SrTiO{sub 3} interfaces

    SciTech Connect (OSTI)

    Balaz, Snjezana; Zeng, Zhaoquan; Brillson, Leonard J.; Department of Physics, The Ohio State University, 191 West Woodruff, Columbus, Ohio 43210

    2013-11-14

    We used a complement of photoemission and cathodoluminescence techniques to measure formation of the BaTiO{sub 3} (BTO) on SrTiO{sub 3} (STO) heterojunction band offset grown monolayer by monolayer by molecular beam epitaxy. X-ray photoemission spectroscopy (XPS) provided core level and valence band edge energies to monitor the valence band offset in-situ as the first few crystalline BTO monolayers formed on the STO substrate. Ultraviolet photoemission spectroscopy (UPS) measured Fermi level positions within the band gap, work functions, and ionization potentials of the growing BTO film. Depth-resolved cathodoluminescence spectroscopy measured energies and densities of interface states at the buried heterojunction. Kraut-based XPS heterojunction band offsets provided evidence for STO/BTO heterojunction linearity, i.e., commutativity and transitivity. In contrast, UPS and XPS revealed a large dipole associated either with local charge transfer or strain-induced polarization within the BTO epilayer.

  4. Effect Of The Plasma Deposition Parameters On The Properties Of Ti/TiN Multilayers For Hard Coatings Applications

    SciTech Connect (OSTI)

    Saoula, N.; Henda, K.; Kesri, R.

    2008-09-23

    In this study, we present the effect of the plasma deposition parameters on the mechanical properties of Ti/TiN multilayers. The elaboration of our films has been carried out by RF-Magnetron Sputtering (13.56 MHz) under nitrogen and argon reactive plasma at low pressure. The film depositions have been done on steel substrates. The first step of our study was the optimization of the depositions conditions in order to obtain good quality films. The amount of nitrogen in the sputtering gases being fixed at 10%. The total pressure was set between 2mTorr to 10mTorr. The deposited multilayers were characterized by X-ray diffraction (XRD), energy dispersive spectroscopy (EDS), atomic force microscopy (AFM) and micro-indentation.

  5. In Situ Spectrophotometric Determination of pH under Geologic CO2 Sequestration Conditions: Method Development and Application

    SciTech Connect (OSTI)

    Shao, Hongbo; Thompson, Christopher J.; Qafoku, Odeta; Cantrell, Kirk J.

    2013-02-25

    Injecting massive amounts of CO2 into deep geologic formations will cause a range of coupled thermal, hydrodynamic, mechanical, and chemical changes. A significant perturbation in water-saturated formations is the pH drop in the reservoir fluids due to CO2 dissolution. Knowing the pH under geological CO2 sequestration conditions is important for a better understanding of the short- and long-term risks associated with geological CO2 sequestration and will help in the design of sustainable sequestration projects. Most previous studies on CO2-rock-brine interactions have utilized thermodynamic modeling to estimate the pH. In this work, a spectrophotometric method was developed to determine the in-situ pH in CO2-H2O-NaCl systems in the presence and absence of reservoir rock by observing the spectra of a pH indicator, bromophenol blue, with a UV-visible spectrophotometer. Effects of temperature, pressure, and ionic strength on the pH measurement were evaluated. Measured pH values in CO2-H2O-NaCl systems were compared with several thermodynamic models. Results indicate that bromophenol blue can be used to accurately determine the pH of brine in contact with supercritical CO2 under geologic CO2 sequestration conditions.

  6. Effect of Cu addition on the martensitic transformation of powder metallurgy processed TiNi alloys

    SciTech Connect (OSTI)

    Kim, Yeon-wook; Choi, Eunsoo

    2014-10-15

    Highlights: M{sub s} of Ti{sub 50}Ni{sub 50} powders is 22 C, while M{sub s} of SPS-sintered porous bulk increases up to 50 C. M{sub s} of Ti{sub 50}Ni{sub 40}Cu{sub 20} porous bulk is only 2 C higher than that of the powders. Recovered stain of porous TiNi and TiNiCu alloy is more than 1.5%. - Abstract: Ti{sub 50}Ni{sub 50} and Ti{sub 50}Ni{sub 30}Cu{sub 20} powders were prepared by gas atomization and their transformation behaviors were examined by means of differential scanning calorimetry and X-ray diffraction. One-step B2B19 transformation occurred in Ti{sub 50}Ni{sub 50} powders, while Ti{sub 50}Ni{sub 30}Cu{sub 20} powders showed B2B19 transformation behavior. Porous bulks with 24% porosity were fabricated by spark plasma sintering. The martensitic transformation start temperature (50 C) of Ti{sub 50}Ni{sub 50} porous bulk is much higher than that (22 C) of the as-solidified powders. However, the martensitic transformation start temperature (35 C) of Ti{sub 50}Ni{sub 30}Cu{sub 20} porous bulk is almost the same as that (33 C) of the powders. When the specimens were compressed to the strain of 8% and then unloaded, the residual strains of Ti{sub 50}Ni{sub 50} and Ti{sub 50}Ni{sub 30}Cu{sub 20} alloy bulks were 3.95 and 3.7%, respectively. However, these residual strains were recovered up to 1.7% after heating by the shape memory phenomenon.

  7. Microstructural evaluation of NiTi-based films deposited by magnetron

    Office of Scientific and Technical Information (OSTI)

    sputtering (Journal Article) | SciTech Connect Microstructural evaluation of NiTi-based films deposited by magnetron sputtering Citation Details In-Document Search Title: Microstructural evaluation of NiTi-based films deposited by magnetron sputtering Shape memory alloy films belonging to the NiTi-based systems were deposited on heated and unheated substrates, by magnetron sputtering in a custom made system, and their structure and composition was analyzed using electron microscopy. Several

  8. Shape-memory transformations of NiTi: Minimum-energy pathways between

    Office of Scientific and Technical Information (OSTI)

    austenite, martensites, and kinetically limited intermediate states (Journal Article) | DOE PAGES Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states « Prev Next » Title: Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states NiTi is the most used shape-memory alloy, nonetheless, a lack of understanding remains regarding

  9. Shape-memory transformations of NiTi: Minimum-energy pathways between

    Office of Scientific and Technical Information (OSTI)

    austenite, martensites, and kinetically limited intermediate states (Journal Article) | SciTech Connect Journal Article: Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states Citation Details In-Document Search Title: Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states NiTi is the most used shape-memory alloy, nonetheless, a

  10. Self-assembled Ni/TiO{sub 2} nanocomposite anodes synthesized via

    Office of Scientific and Technical Information (OSTI)

    electroless plating and atomic layer deposition on biological scaffolds (Journal Article) | SciTech Connect Self-assembled Ni/TiO{sub 2} nanocomposite anodes synthesized via electroless plating and atomic layer deposition on biological scaffolds Citation Details In-Document Search Title: Self-assembled Ni/TiO{sub 2} nanocomposite anodes synthesized via electroless plating and atomic layer deposition on biological scaffolds Ni(core)/TiO{sub 2}(shell) nanocomposite anodes were fabricated on

  11. Shape-memory transformations of NiTi: Minimum-energy pathways between

    Office of Scientific and Technical Information (OSTI)

    austenite, martensites, and kinetically limited intermediate states (Journal Article) | DOE PAGES Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states Title: Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states NiTi is the most used shape-memory alloy, nonetheless, a lack of understanding remains regarding the associated

  12. Spin and orbital Ti magnetism at LaMnO3/SrTiO3 interfaces

    SciTech Connect (OSTI)

    Garcial-Barriocanal, J; Cezar, J. C.; Bruno, F. Y.; Thakur, P.; Brookes, N. B.; Utfeld, C.; Riviera-Calzada, A.; Giblin, S. R.; Taylor, J. W.; Duffy, J. A.; Dugdale, S. B.; Nakamura, T.; Kodama, K.; Leon, C.; Okamoto, Satoshi; Santamaria, J.

    2010-01-01

    In systems with strong electron-lattice coupling, such as manganites, orbital degeneracy is lifted, what causes a null expectation value of the orbital moment. Magnetic structure is thus determined by spin-spin superexchange. In titanates, however, with much smaller Jahn-Teller distortions, orbital degeneracy might allow non-zero values of the orbital magnetic moment. Accordingly, novel forms of ferromagnetic superexchange interaction unique to t2g electrons systems have been theoretically predicted, although their experimental observation has remained elusive. Here we report a new kind of Ti3+ ferromagnetism at LaMnO3/SrTiO3 epitaxial interfaces. It results from charge transfer to the empty conduction band of the titanate and has spin and orbital contributions evidencing the role played by orbital degeneracy. The possibility of tuning magnetic alignment (ferromagnetic or antiferromagnetic) of Ti and Mn moments by structural parameters is demonstrated. This result will provide important clues for the understanding of the effects of orbital degeneracy in superexchange coupling.

  13. Synthesis of Highly Ordered TiO2 Nanotubes Using Ionic Liquids for Photovoltaics Applications

    SciTech Connect (OSTI)

    2009-04-01

    This factsheet describes a study that deals with a new, green approach of synthesizing highly ordered TiO2 nanotubes using ionic liquids for photovoltaics (PV) applications.

  14. Effects of hydrochloric acid treatment of TiO{sub 2}nanoparticles...

    Office of Scientific and Technical Information (OSTI)

    Effects of hydrochloric acid treatment of TiOsub 2 nanoparticlesnanofibers bilayer film on the photovoltaic properties of dye-sensitized solar cells Citation Details In-Document ...

  15. Features of a priori heavy doping of the n-TiNiSn intermetallic semiconductor

    SciTech Connect (OSTI)

    Romaka, V. A.; Rogl, P.; Romaka, V. V.; Hlil, E. K.; Stadnyk, Yu. V.; Budgerak, S. M.

    2011-07-15

    The crystal structure, the distribution of electron density, and the energy, kinetic, and magnetic properties of the n-TiNiSn intermetallic semiconductor are investigated. It is shown that a priori doping of n-TiNiSn with donors originates from partial, up to 0.5 at %, redistribution of Ti and Ni atoms in crystallographic sites of Ti atoms. The correlation is established between the donor concentration, amplitude of modulation of the continuous energy bands, and degree of filling of low-scale fluctuation potential wells with charge carriers. The results obtained are discussed within the Shklovskii-Efros model of a heavily doped and compensated semiconductor.

  16. Epitaxial Cr on n-SrTiO3(001)An ideal Ohmic contact

    SciTech Connect (OSTI)

    Capan, Cigdem; Sun, Guangyuan; Bowden, Mark E.; Chambers, Scott A.

    2012-01-30

    Epitaxial Cr metallizations grown on n-SrTiO3(001) by molecular beam epitaxy are shown to result in an ordered interface with Cr bound to O in the terminal TiO2 layer, no reduction of the SrTiO3, and a near-perfect Ohmic contact. Cr/n-SrTiO3(001) thus constitutes an ideal interface between a pure metal and wide gap oxide in which interface redox chemistry does not occur, and the Fermi level remains unpinned.

  17. Epitaxial Cr on n-SrTiO{sub 3}(001) - An ideal Ohmic contact

    SciTech Connect (OSTI)

    Capan, C.; Sun, G. Y.; Bowden, M. E.; Chambers, S. A.

    2012-01-30

    Epitaxial Cr metallizations grown on n-SrTiO{sub 3}(001) by molecular beam epitaxy are shown to result in an ordered interface with Cr bound to O in the terminal TiO{sub 2} layer, no reduction of the SrTiO{sub 3}, and a near-perfect Ohmic contact. Cr/n-SrTiO{sub 3}(001) thus constitutes an ideal interface between a pure metal and wide gap oxide in which interface redox chemistry does not occur, and the Fermi level remains unpinned.

  18. Self-assembled Ni/TiO{sub 2} nanocomposite anodes synthesized...

    Office of Scientific and Technical Information (OSTI)

    Ni(core)TiOsub 2(shell) nanocomposite anodes were fabricated on three-dimensional, self-assembled nanotemplates of Tobacco mosaic virus using atomic layer deposition, exhibiting ...

  19. Characterization of Heat-Wave Propagation through Laser-Driven Ti-Doped

    Office of Scientific and Technical Information (OSTI)

    Underdense Plasma (Journal Article) | SciTech Connect Characterization of Heat-Wave Propagation through Laser-Driven Ti-Doped Underdense Plasma Citation Details In-Document Search Title: Characterization of Heat-Wave Propagation through Laser-Driven Ti-Doped Underdense Plasma The propagation of a laser-driven heat-wave into a Ti-doped aerogel target was investigated. The temporal evolution of the electron temperature was derived by means of Ti K-shell x-ray spectroscopy, and compared with

  20. Role of the interface on radiation damage in the SrTiO{sub 3...

    Office of Scientific and Technical Information (OSTI)

    SrTiOsub 3 (STO) thin films grown on a single crystal ... 87545 (United States) Materials Science and Technology Division, ... TITANATES; SUBSTRATES; THIN FILMS; TRANSMISSION ...

  1. Impact of symmetry on the ferroelectric properties of CaTiO3...

    Office of Scientific and Technical Information (OSTI)

    properties of CaTiO3 thin films Citation Details ... Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA Department of Materials Science ...

  2. Large oriented arrays and continuous films of TiO2 based nanotubes.

    SciTech Connect (OSTI)

    Xu, Huifang; Liu, Jun; Voigt, James A.; Tian, Zhengrong Ryan; McKenzie, Bonnie Beth

    2003-08-01

    We report for the first time a one-step, templateless method to directly prepare large arrays of oriented TiO{sub 2}-based nanotubes and continuous films. These titania nanostructures can also be easily prepared as conformal coatings on a substrate. The nanostructured films were formed on a Ti substrate seeded with TiO{sub 2} nanoparticles. SEM and TEM results suggested that a folding mechanism of sheetlike structures was involved in the formation of the nanotubes. The oriented arrays of TiO{sub 2} nanotubes, continuous films, and coatings are expected to have potentials for applications in catalysis, filtration, sensing, photovoltaic cells, and high surface area electrodes.

  3. The crystal and magnetic structure of Ti-substituted LaCrO{sub 3} (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect The crystal and magnetic structure of Ti-substituted LaCrO{sub 3} Citation Details In-Document Search Title: The crystal and magnetic structure of Ti-substituted LaCrO{sub 3} Graphical abstract: Rietveld refinement plot of La(Cr{sub 0.90}Ti{sub 0.10})O{sub 3}; the inset shows the antiferromagnetic G{sub x}-type structure occurring at the Cr sub-lattice. Research highlights: {yields} Magnetic structure of Ti-substituted LaCrO{sub 3}. {yields} Spins on the Cr-site

  4. A New Method of Low Cost Production of Ti Alloys to Reduce Energy...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Cost Microstructures produced by sintering of TiH 2 in (a) hydrogen, (b) vacuum (SEM ) Refine grain sizes by controlling H 2 content and phase transformation in ...

  5. A novel 3D structure composed of strings of hierarchical TiO{sub 2} spheres formed on TiO{sub 2} nanobelts with high photocatalytic properties

    SciTech Connect (OSTI)

    Jiang, Yongjian; Li, Meicheng; Song, Dandan; Li, Xiaodan; Yu, Yue

    2014-03-15

    A novel hierarchical titanium dioxide (TiO{sub 2}) composite nanostructure with strings of anatase TiO{sub 2} hierarchical micro-spheres and rutile nanobelts framework (TiO{sub 2} HSN) is successfully synthesized via a one-step hydrothermal method. Particularly, the strings of hierarchical spheres are assembled by very thin TiO{sub 2} nanosheets, which are composed of highly crystallized anatase nanocrystals. Meanwhile, the HSN has a large surface area of 191 m{sup 2}/g, which is about 3 times larger than Degussa P25. More importantly, the photocatalytic activity of HSN and P25 were evaluated by the photocatalytic oxidation decomposition of methyl orange (MO) under UV light illumination, and the TiO{sub 2} HSN shows enhanced photocatalytic activity compared with Degussa P25, as result of its continuous hierarchical structures, special conductive channel and large specific surface area. With these features, the hierarchical TiO{sub 2} may have more potential applications in the fields of dye-sensitized solar cells and lithium ion batteries. -- Graphical abstract: Novel TiO{sub 2} with anatase micro-spheres and rutile nanobelts is synthesized. Enhanced photocatalysis is attributed to hierarchical structures (3D spheres), conductive channel (1D nanobelts) and large specific surface area (2D nanosheet). Highlights: • The novel TiO{sub 2} nanostructure (HSN) is fabricated for the first time. • HSN is composed of strings of anatase hierarchical spheres and rutile nanobelt. • HSN presents a larger S{sub BET} of 191 m{sup 2}/g, 3 times larger than the Degussa P25 (59 m{sup 2}/g). • HSN owns three kinds of dimensional TiO{sub 2} (1D, 2D and 3D) simultaneously. • HSN exhibits better photocatalytic performance compared with Degussa P25.

  6. Solar photocatalytic activities of porous Nb-doped TiO{sub 2} microspheres by coupling with tungsten oxide

    SciTech Connect (OSTI)

    Kou, Yanqiang; Yang, Jikai; Li, Bing; Fu, Shencheng

    2015-03-15

    Highlights: Nb-TiO{sub 2}/WO{sub 3} was prepared by USP method combined impregnation method. Nb-doping extend the spectral absorption of TiO{sub 2} into visible spectrum. Nb-TiO{sub 2}/WO{sub 3} has a similar optical band gap as Nb-TiO{sub 2}. PL spectra indicate WO{sub 3} can accept the photoexcited electrons from Nb-TiO{sub 2}. Nb-TiO{sub 2}/WO{sub 3} shows higher activity than TiO{sub 2} and Nb-TiO{sub 2} under solar light. - Abstract: Nb doped TiO{sub 2} microspheres modified with WO{sub 3} (Nb-TiO{sub 2}/WO{sub 3}) was prepared by ultrasonic spray pyrolysis method combined with impregnation method. The microspheres were characterized with SEM, TEM, XRD, BET, photoluminescence and UVvis absorption spectra. The Nb-doping was observed to extend the spectral absorption of TiO{sub 2} into visible spectrum, and the absorption onset was red-shifted for about 88 nm compared to pristine TiO{sub 2} microspheres. Nb-TiO{sub 2}/WO{sub 3} microspheres do not display a red-shifted absorption edge compared with Nb doped TiO{sub 2} microspheres. Under solar irradiation, Nb-TiO{sub 2}/WO{sub 3} microspheres showed higher photocatalytic activity for methylene blue degradation compared with that of pure TiO{sub 2} microspheres and Nb doped TiO{sub 2} microspheres, which could be ascribed to the extended light absorption range and the suppression of electron-hole pair recombination.

  7. PH Sensitive Polymers for Improving Reservoir Sweep and Conformance Control in Chemical Flooring

    SciTech Connect (OSTI)

    Mukul Sharma; Steven Bryant; Chun Huh

    2008-03-31

    There is an increasing opportunity to recover bypassed oil from depleted, mature oilfields in the US. The recovery factor in many reservoirs is low due to inefficient displacement of the oil by injected fluids (typically water). The use of chemical flooding methods to increase recovery efficiencies is severely constrained by the inability of the injected chemicals to contact the bypassed oil. Low sweep efficiencies are the primary cause of low oil recoveries observed in the field in chemical flooding operations even when lab studies indicate high oil recovery efficiency. Any technology that increases the ability of chemical flooding agents to better contact the remaining oil and reduce the amount of water produced in conjunction with the produced oil will have a significant impact on the cost of producing oil domestically in the US. This translates directly into additional economically recoverable reserves, which extends the economic lives of marginal and mature wells. The objective of this research project was to develop a low-cost, pH-triggered polymer for use in IOR processes to improve reservoir sweep efficiency and reservoir conformance in chemical flooding. Rheological measurements made on the polymer solution, clearly show that it has a low viscosity at low pH and exhibits a sudden increase in viscosity (by 2 orders of magnitude or more) at a pH of 3.5 to 4. This implies that the polymer would preferentially flow into zones containing water since the effective permeability to water is highest in these zones. As the pH of the zone increases due to the buffering capacity of the reservoir rock, the polymer solution undergoes a liquid to gel transition causing a sharp increase in the viscosity of the polymer solution in these zones. This allows operationally robust, in-depth conformance treatment of such water bearing zones and better mobility control. The rheological properties of HPAM solutions were measured. These include: steady-shear viscosity and viscoelastic behavior as functions of pH; shear rate; polymer concentration; salinity, including divalent ion effects; polymer molecular weight; and degree of hydrolysis. A comprehensive rheological model was developed for HPAM solution rheology in terms of: shear rate; pH; polymer concentration; and salinity, so that the spatial and temporal changes in viscosity during the polymer flow in the reservoir can be accurately modeled. A series of acid coreflood experiments were conducted to understand the geochemical reactions relevant for both the near-wellbore injection profile control and for conformance control applications. These experiments showed that the use hydrochloric acid as a pre-flush is not viable because of the high reaction rate with the rock. The use of citric acid as a pre-flush was found to be quite effective. This weak acid has a slow rate of reaction with the rock and can buffer the pH to below 3.5 for extended periods of time. With the citric acid pre-flush the polymer could be efficiently propagated through the core in a low pH environment i.e. at a low viscosity. The transport of various HPAM solutions was studied in sandstones, in terms of permeability reduction, mobility reduction, adsorption and inaccessible pore volume with different process variables: injection pH, polymer concentration, polymer molecular weight, salinity, degree of hydrolysis, and flow rate. Measurements of polymer effluent profiles and tracer tests show that the polymer retention increases at the lower pH. A new simulation capability to model the deep-penetrating mobility control or conformance control using pH-sensitive polymer was developed. The core flood acid injection experiments were history matched to estimate geochemical reaction rates. Preliminary scale-up simulations employing linear and radial geometry floods in 2-layer reservoir models were conducted. It is clearly shown that the injection rate of pH-sensitive polymer solutions can be significantly increased by injecting it at a pH below 3.5 (at a fixed bottom-hole pressure). This improvement in injectivity by a fa

  8. Pb{sub 5}Fe{sub 3}TiO{sub 11}Cl: A rare example of Ti(IV) in a square pyramidal oxygen coordination

    SciTech Connect (OSTI)

    Batuk, Maria; Batuk, Dmitry; Abakumov, Artem M.; Hadermann, Joke

    2014-07-01

    A new oxychloride Pb{sub 5}Fe{sub 3}TiO{sub 11}Cl has been synthesized using the solid state method. Its crystal and magnetic structure was investigated in the 1.5550 K temperature range using electron diffraction, high angle annular dark field scanning transmission electron microscopy, atomic resolution energy dispersive X-ray spectroscopy, neutron and X-ray powder diffraction. At room temperature Pb{sub 5}Fe{sub 3}TiO{sub 11}Cl crystallizes in the P4/mmm space group with the unit cell parameters a=3.91803(3) and c=19.3345(2) . Pb{sub 5}Fe{sub 3}TiO{sub 11}Cl is a new n=4 member of the oxychloride perovskite-based homologous series A{sub n+1}B{sub n}O{sub 3n?1}Cl. The structure is built of truncated Pb{sub 3}Fe{sub 3}TiO{sub 11} quadruple perovskite blocks separated by CsCl-type Pb{sub 2}Cl slabs. The perovskite blocks consist of two layers of (Fe,Ti)O{sub 6} octahedra sandwiched between two layers of (Fe,Ti)O{sub 5} square pyramids. The Ti{sup 4+} cations are preferentially located in the octahedral layers, however, the presence of a noticeable amount of Ti{sup 4+} in a five-fold coordination environment has been undoubtedly proven using neutron powder diffraction and atomic resolution compositional mapping. Pb{sub 5}Fe{sub 3}TiO{sub 11}Cl is antiferromagnetically ordered below 450(10) K. The ordered Fe magnetic moments at 1.5 K are 4.06(4) ?{sub B} and 3.86(5) ?{sub B} on the octahedral and square-pyramidal sites, respectively. - Highlights: Pb{sub 5}Fe{sub 3}TiO{sub 11}Cl has been synthesized using the solid state method. The structure has been refined using neutron powder diffraction data at 1.5550 K. It is a new n=4 member of the perovskite-related homologous series A{sub n+1}B{sub n}O{sub 3n?1}Cl. Ti{sup 4+} cations have both octahedral and square-pyramidal coordination environment. Pb{sub 5}Fe{sub 3}TiO{sub 11}Cl is antiferromagnetically ordered below T{sub N}?450 K.

  9. Alturas LLC- FE Dkt. No. 14-55-NG (FTA)

    Broader source: Energy.gov [DOE]

    The Office of Fossil Energy gives notice of receipt of an application filed on April 18, 2014, by Alturas LLC requesting long-term authority to export up to a total of 1.5 million metric tons ...

  10. DOE/AMO NG Infrastructure R & D & Methane emissions Mitigation...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    ... with the FAA to decide on appropriate regulation of flight requirements Task 2 - ... Network Measuring Pressure Temperature Humidity Flow (volume and flow ...

  11. completed-ng-projects | netl.doe.gov

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Projects Completed Natural Gas and Unconventional Resources Projects DE-FE0001175 Targeted Technology Transfer for Oil and Natural Gas Petroleum Technology Transfer Council...

  12. Structural and spectroscopic properties of high temperature prepared ZrO₂–TiO₂ mixed oxides

    SciTech Connect (OSTI)

    Gionco, Chiara; Battiato, Alfio; Vittone, Ettore; Paganini, Maria Cristina; Giamello, Elio

    2013-05-01

    ZrO₂-TiO₂ mixed oxides of various composition, with the molar fraction of TiO₂ ranging from 0.1% to 15%, have been prepared via sol-gel synthesis and then calcined at 1273 K to check both their thermal stability and physicochemical properties. These solids are usually employed in photocatalytic processes and as active phase supports in heterogeneous catalysis. As indicated by X-ray diffraction and Raman spectroscopy, solid solutions based on Ti ions diluted in the ZrO₂ matrix are formed in the whole range of Ti molar fraction examined. Materials with low Ti loading (0.1%–1%) are basically constituted by the monoclinic phase of ZrO₂ while the tetragonal phase becomes prevalent at 15% of TiO₂ molar fraction. The presence of Ti ions modify the electronic structure of the solid as revealed by investigation of the optical properties. The typical band gap transition of ZrO₂ undergoes, in fact, a red shift roughly proportional to the Ti loading which reach the remarkable value of 1.6 eV for the sample with 10% of molar Ti concentration. Comparing chemical analysis of the solids with XPS data it has been put into evidence that the titanium ions distribution into the solid is not uniform and the concentration of Ti⁴⁺ tend to be higher in subsurface layers than in the crystal bulk. The introduction of titanium ions in the structure increases the reducibility of the solid. Annealing under vacuum at various temperatures causes oxygen depletion with consequent reduction of the solid which shows up mainly in terms of formation of Ti³⁺ reduced centres which are characterized by a typical EPR signal. Ti³⁺ defects forms, as also forecast by theoretical modelling of the solid, as their energy is lower than that of other possible reduced defective centers. The reduced solids are able to transfer electrons to adsorbed oxygen molecules in mild condition resulting in the formation of surface superoxide anions (O₂⁻) which are stabilized on surface Zr⁴⁺ or, alternatively, on Ti⁴⁺ ions according to the sample composition. - Graphical abstract: The presence of Ti in ZrO₂ modifies UV–vis and electronic properties of mixed oxides. Highlights: • ZrO₂–TiO₂ mixed oxides have been prepared via sol–gel synthesis. • Solids with low Ti loading are constituted by the monoclinic phase of ZrO₂. • The presence of Ti ions modify the electronic structure of the solid. • The introduction of titanium ions increases the reducibility of the solid.

  13. Development of On-Line Spectroscopic pH Monitoring for Nuclear Fuel Reprocessing Plants: Weak Acid Schemes

    SciTech Connect (OSTI)

    Casella, Amanda J.; Hylden, Laura R.; Campbell, Emily L.; Levitskaia, Tatiana G.; Peterson, James M.; Smith, Frances N.; Bryan, Samuel A.

    2015-05-19

    Knowledge of real-time solution properties and composition is a necessity for any spent nuclear fuel reprocessing method. Metal-ligand speciation in aqueous solutions derived from the dissolved commercial spent fuel is highly dependent upon the acid concentration/pH, which influences extraction efficiency and the resulting speciation in the organic phase. Spectroscopic process monitoring capabilities, incorporated in a counter current centrifugal contactor bank, provide a pathway for on-line real-time measurement of solution pH. The spectroscopic techniques are process-friendly and can be easily configured for on-line applications, while classic potentiometric pH measurements require frequent calibration/maintenance and have poor long-term stability in aggressive chemical and radiation environments. Our research is focused on developing a general method for on-line determination of pH of aqueous solutions through chemometric analysis of Raman spectra. Interpretive quantitative models have been developed and validated under the range of chemical composition and pH using a lactic acid/lactate buffer system. The developed model was applied to spectra obtained on-line during solvent extractions performed in a centrifugal contactor bank. The model predicted the pH within 11% for pH > 2, thus demonstrating that this technique could provide the capability of monitoring pH on-line in applications such as nuclear fuel reprocessing.

  14. ORISE report shows number of health physics Ph.D.s declined in 2009

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    ORISE report shows number of health physics Ph.D.s declined in 2009 FOR IMMEDIATE RELEASE June 15, 2010 FY10-37 OAK RIDGE, Tenn.-Health physics undergraduate degrees increased slightly in 2009 continuing a six-year trend, but doctorate degrees reported a 40-year low, says a report recently released by the Oak Ridge Institute for Science and Education. The report also showed the number of M.S. degrees was 21 percent less than in 2008. The ORISE report, Health Physics Enrollments and Degrees

  15. ORISE: After a Brief Decline, Recent Foreign Ph.D. Graduates are Staying in

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    the U.S. at Near-record Levels After a Brief Decline, Recent Foreign Ph.D. Graduates are Staying in the U.S. at Near-record Levels FOR IMMEDIATE RELEASE: Feb. 3, 2010 FY10-20 OAK RIDGE, Tenn.-Two years after completing doctoral degrees at United States (U.S.) universities, 67% of foreign students graduating in 2005 remained in the U.S., according to a new report issued by the Oak Ridge Institute for Science and Education (ORISE) and funded by the National Science Foundation (NSF). This is a

  16. Dark Energy: A Universe Out of Control Nicholas B. Suntzeff. Ph. D.

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    Dark Energy: A Universe Out of Control Nicholas B. Suntzeff. Ph. D. Mitchell/Heep/Munnerlyn Professor of Observational Astronomy Texas A&M University Nobel Prize in Physics 2011 Ferdinand Magellan (1519-1521) Our Universe The most profound observation in modern cosmology is ? Why is the sky black at night? Olber's Paradox Weird stuff about the Universe * When you look deep into the sky - it is the same everywhere - galaxies we see in one direction have not seen the galaxies we see in the

  17. Visible light photocatalytic degradation of 4-chlorophenol using vanadium and nitrogen co-doped TiO{sub 2}

    SciTech Connect (OSTI)

    Jaiswal, R.; Kothari, D. C.; Patel, N.; Miotello, A.

    2013-02-05

    Vanadium and Nitrogen were codoped in TiO{sub 2} photocatalyst by Sol-gel method to utilize visible light more efficiently for photocatalytic reactions. A noticeable shift of absorption edge to visible light region was obtained for the singly-doped namely V-TiO{sub 2}, N-TiO{sub 2} and codoped V-N-TiO{sub 2} samples in comparison with undoped TiO{sub 2}, with smallest band gap obtained with codoped-TiO{sub 2}. The photocatalytic activities for all TiO{sub 2} photocatalysts were tested by 4-chlorophenol (organic pollutant) degradation under visible light irradiation. It was found that codoped TiO{sub 2} exhibits the best photocatalytic activity, which could be attributed to the synergistic effect produced by V and N dopants.

  18. PAA-15-0001 - In the Matter of Rolf E. Carlson, PhD | Department of Energy

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    PAA-15-0001 - In the Matter of Rolf E. Carlson, PhD PAA-15-0001 - In the Matter of Rolf E. Carlson, PhD On July 31, 2015, OHA issued a decision denying a Privacy Act Appeal filed by Rolf E. Carlson, PhD from a determination issued to him by the DOE's National Nuclear Security Administration (NNSA). In the Appeal, the Appellant challenged the denial of his request to amend or correct his Personnel Security File (PSF). NNSA denied the request to amend the Appellant's PSF because his employer had

  19. Stable atomic structure of NiTi austenite

    SciTech Connect (OSTI)

    Zarkevich, Nikolai A; Johnson, Duane D

    2014-08-01

    Nitinol (NiTi), the most widely used shape-memory alloy, exhibits an austenite phase that has yet to be identified. The usually assumed austenitic structure is cubic B2, which has imaginary phonon modes, hence it is unstable. We suggest a stable austenitic structure that on average has B2 symmetry (observed by x-ray and neutron diffraction), but it exhibits finite atomic displacements from the ideal B2 sites. The proposed structure has a phonon spectrum that agrees with that from neutron scattering, has diffraction spectra in agreement with x-ray diffraction, and has an energy relative to the ground state that agrees with calorimetry data.

  20. Injection mode-locking Ti-sapphire laser system

    DOE Patents [OSTI]

    Hovater, James Curtis; Poelker, Bernard Matthew

    2002-01-01

    According to the present invention there is provided an injection modelocking Ti-sapphire laser system that produces a unidirectional laser oscillation through the application of a ring cavity laser that incorporates no intracavity devices to achieve unidirectional oscillation. An argon-ion or doubled Nd:YVO.sub.4 laser preferably serves as the pump laser and a gain-switched diode laser serves as the seed laser. A method for operating such a laser system to produce a unidirectional oscillating is also described.

  1. HNF-SD-WM-TI-740, Rev. OC

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    84047 HNF-SD-WM-TI-740, Rev. OC Standard Inventories of Chemicals and Radionuclides in Hanford Site Tank Wastes M. J. Kupfer, A. L. Boldt, K. N. Hodgson, L. W. Shelton, B. C. Simpson, and R. A. Watrous (LMHC); M. D. LeClair (SAIC); G. 1. Borsheim (BA); R. T. Winward (MA); B. A. Higley and R. M. Orme (NHC); N. G. Colton (PNNL); S. L. Lambert and D. E. Place (Cogema); and W. W. Schulz (112S) Lockheed Martin Hanford Corporation, Richland, WA 99352 U.S. Department of Energy Contract

  2. An Experimental and Theoretical Multi-Mbar Study of Ti-6Al-4V

    SciTech Connect (OSTI)

    Tegner, B E; Macleod, S G; CYNN, H; Proctor, J; Evans, W J; McMahon, M I; Ackland, G J

    2011-04-13

    We report results from an experimental and theoretical study of the room temperature (RT) compression of the ternary alloy Ti-6Al-4V. In this work, we have extended knowledge of the equation of state (EOS) from 40 GPa to 221 GPa, and observed a different sequence of phase transitions to that reported previously for pure Ti.

  3. Preparation and properties of ce-doped TiO{sub 2} photocatalyst

    SciTech Connect (OSTI)

    Yan, Ningning; Zhu, Zhongqi; Zhang, Jin; Zhao, Zongyan; Liu, Qingju

    2012-08-15

    Highlights: ? The cerium ion doped TiO{sub 2} (Ce-TiO{sub 2}) powders were prepared and characterized. ? The spectrum absorption region of Ce-TiO{sub 2} is red-shifted to visible light. ? The recombination of photo-generated electron-hole pairs of Ce-TiO{sub 2} is inhibited. ? The photocatalytic activity was effected by Ce ion content and greatly improved. -- Abstract: TiO{sub 2} nanoparticles doped with different content of Ce ion were prepared by solgel method. The samples were characterized by XRD, XPS, TEM, UVVis, and PL, the photocatalytic activity was evaluated by photocatalytic degradation of methylene blue (MB) under the irradiation of fluorescent lamp. The results indicate that Ce ion is incorporated into the lattice of TiO{sub 2}, which can restrain the increase of grain size, broaden the absorption region to visible light, and inhibit the recombination of the photo-generated electron and hole pairs. Moreover, the photocatalytic activity of Ce-TiO{sub 2} in MB degradation is evidently enhanced. The MB degradation rate of the sample with Ce:Ti = 0.33% (molar ratio) in 8 h is 90.03%, which is much higher than that of P25 (68.19%).

  4. Monomer volume fraction profiles in pH responsive planar polyelectrolyte brushes

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mahalik, Jyoti P.; Yang, Yubo; Deodhar, Chaitra V.; Ankner, John Francis; Lokitz, Bradley S.; Kilbey, II, S. Michael; Sumpter, Bobby G.; Kumar, Rajeev

    2016-03-06

    Spatial dependencies of monomer volume fraction profiles of pH responsive polyelectrolyte brushes were investigated using field theories and neutron reflectivity experiments. In particular, planar polyelectrolyte brushes in good solvent were studied and direct comparisons between predictions of the theories and experimental measurements are presented. The comparisons between the theories and the experimental data reveal that solvent entropy and ion-pairs resulting from adsorption of counterions from the added salt play key roles in affecting the monomer distribution and must be taken into account in modeling polyelectrolyte brushes. Furthermore, the utility of this physics-based approach based on these theories for the predictionmore » and interpretation of neutron reflectivity profiles in the context of pH responsive planar polyelectrolyte brushes such as polybasic poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) and polyacidic poly(methacrylic acid) (PMAA) brushes is demonstrated. The approach provides a quantitative way of estimating molecular weights of the polymers polymerized using surface-initiated atom transfer radical polymerization.« less

  5. TiN/VN composites with core/shell structure for supercapacitors

    SciTech Connect (OSTI)

    Dong, Shanmu; Chen, Xiao; Gu, Lin; Zhou, Xinhong; Wang, Haibo; Liu, Zhihong; Han, Pengxian; Yao, Jianhua; Wang, Li; Cui, Guanglei; Chen, Liquan; Institute of Physics, Chinese Academy of Sciences, Beijing 100080

    2011-06-15

    Research highlights: {yields} Vanadium and titanium nitride nanocomposite with core-shell structure was prepared. {yields} TiN/VN composites with different V:Ti molar ratios were obtained. {yields} TiN/VN composites can provide promising electronic conductivity and favorable capacity storage. -- Abstract: TiN/VN core-shell composites are prepared by a two-step strategy involving coating of commercial TiN nanoparticles with V{sub 2}O{sub 5}.nH{sub 2}O sols followed by ammonia reduction. The highest specific capacitance of 170 F g{sup -1} is obtained when scanned at 2 mV s{sup -1} and a promising rate capacity performance is maintained at higher voltage sweep rates. These results indicate that these composites with good electronic conductivity can deliver a favorable capacity performance.

  6. Revealing the atomic and electronic structure of a SrTiO{sub 3}/LaNiO{sub 3}/SrTiO{sub 3} heterostructure interface

    SciTech Connect (OSTI)

    Zhang, Zaoli; Soltan, S.; Schmid, H.; Habermeier, H.-U.; Keimer, B.; Kaiser, U.

    2014-03-14

    The atomic structures of SrTiO{sub 3} (STO)/LaNiO{sub 3} (LNO)/STO heterostructure interfaces were investigated by spherical aberration-corrected (C{sub S}) (scanning) transmission electron microscopy. Atomic displacement and lattice distortion measurements and electron energy loss spectroscopy (EELS) were used to quantitatively analyze the distortion of the interfacial octahedra and the bond length at the interfaces. Combined with high-resolution transmission electron microscopy (HRTEM) and scanning transmission electron microscopy analyses, two distinct interfacial atomic terminating layers are unambiguously determined. Ensuing quantitative HRTEM measurements revealed that the Ni-O bond length in the interfacial octahedral is elongated at the bottom interface (NiO{sub 2}-SrO). Atomic displacement shows structural relaxation effects when crossing the interfaces and lattice distortions across the interface is more pronounced in LNO than in STO. The Ti/O atomic ratio, La and Ti relative atomic ratio as derived by EELS quantification indicate non-stoichiometric composition at the interfaces. Distinct fine structures of Ti-L{sub 2,3} edge and O-K edge at the bottom and top interfaces are observed. By comparison, we are able to estimate Ti valency at both interfaces. Combining the structural distortions and Ti valency, the polar discontinuity and charge transfer at the interfaces are discussed.

  7. Active wear and failure mechanisms of TiN-coated high speed steel and TiN-coated cemented carbide tools when machining powder metallurgically made stainless steels

    SciTech Connect (OSTI)

    Jiang, L.; Haenninen, H.; Paro, J.; Kauppinen, V.

    1996-09-01

    In this study, active wear and failure mechanisms of both TiN-coated high speed steel and TiN-coated cemented carbide tools when machining stainless steels made by powder metallurgy in low and high cutting speed ranges, respectively, have been investigated. Abrasive wear mechanisms, fatigue-induced failure, and adhesive and diffusion wear mechanisms mainly affected the tool life of TiN-coated high speed steel tools at cutting speeds below 35 m/min, between 35 and 45 m/min, and over 45 m/min, respectively. Additionally, fatigue-induced failure was active at cutting speeds over 45 m/min in the low cutting speed range when machining powder metallurgically made duplex stainless steel 2205 and austenitic stainless steel 316L. In the high cutting speed range, from 100 to 250 m/min, fatigue-induced failure together with diffusion wear mechanism, affected the tool life of TiN-coated cemented carbide tools when machining both 316L and 2205 stainless steels. It was noticed that the tool life of TiN-coated high speed steel tools used in the low cutting speed range when machining 2205 steel was longer than that when machining 316L steel, whereas the tool life of TiN-coated cemented carbide tools used in the high cutting speed range when machining 316L steel was longer than that when machining 2205 steel.

  8. Lack of correlation between extended pH monitoring and scintigraphy in the evaluation of infants with gastroesophageal reflux

    SciTech Connect (OSTI)

    Tolia, V.; Calhoun, J.A.; Kuhns, L.R.; Kauffman, R.E. )

    1990-05-01

    Sixty-nine infants younger than 1 year of age, with symptoms of persistent vomiting, recurrent choking, apnea, persistent cough, or stridor, were evaluated for gastroesophageal reflux. All infants underwent extended intraesophageal pH monitoring for 16 to 24 hours as well as gastroesophageal scintigraphy with technetium 99m sulfur colloid to study the correlation between the two tests. Forty-eight infants exhibited reflux with extended pH monitoring whereas 46 infants showed reflux with scintigraphy. However, the diagnosis of reflux in individual patients by extended pH monitoring corresponded poorly with the diagnosis of reflux in the same patients by scintigraphy. Similarly, no correlation was observed between extended pH monitoring and scintigraphy results, whether expressed as percent gastric emptying or as gastroesophageal reflux ratio. We conclude that extended pH monitoring and scintigraphy measure different pathophysiologic phenomena and detect reflux under different conditions. The ability of these tests to detect reflux may be complementary and they may be of greatest value when used together to enhance the sensitivity and specificity of the diagnostic evaluation. Extended pH monitoring and scintigraphy should not be used interchangeably to monitor gastroesophageal reflux.

  9. Fabrication and characterization of photovoltaic devices based on perovskite compounds with TiO{sub 2} nanoparticles

    SciTech Connect (OSTI)

    Kanayama, Masato Oku, Takeo Suzuki, Atsushi; Yamada, Masahiro; Sakamoto, Hiroki; Fukunishi, Sakiko; Kohno, Kazufumi

    2015-02-27

    Perovskite-type photovoltaic devices were fabricated by a spin-coating method using a mixture solution. The compact and meso-porous TiO{sub 2} of the solar cells were fabricated from TiO{sub 2} nanoparticles and sol, and the photovoltaic properties and microstructures were characterized. The conversion efficiencies were improved by the combination of TiO{sub 2} nanoparticles and sol. Current density was also improved by increasing numbers of spin-coatings of meso-porous TiO{sub 2}. Thick meso-porous TiO2 layers would assist the construction of perovskite layers and block of the leak current.

  10. Brazing ZrO{sub 2} ceramic to Ti6Al4V alloy using NiCrSiB amorphous filler foil: Interfacial microstructure and joint properties

    SciTech Connect (OSTI)

    Cao, J., E-mail: cao_jian@hit.edu.cn [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Song, X.G., E-mail: song_xiaoguohit@yahoo.com.cn [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Li, C., E-mail: li_chun1989@yahoo.cn [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Zhao, L.Y., E-mail: Zhao_ly@163.com [State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China); Feng, J.C., E-mail: feng_jicai@163.com [Shandong Provincial Key Laboratory of Special Welding Technology, Harbin Institute of Technology at Weihai, Weihai 264209 (China); State Key Laboratory of Advanced Welding and Joining, Harbin Institute of Technology, Harbin 150001 (China)

    2013-07-15

    Reliable brazing of ZrO{sub 2} ceramic and Ti6Al4V alloy was achieved using NiCrSiB amorphous filler foil. The interfacial microstructure of ZrO{sub 2}/Ti6Al4V joints was characterized by scanning electron microscope, energy dispersive spectrometer and micro-focused X-ray diffractometer. The effects of brazing temperature on the interfacial microstructure and joining properties of brazed joints were investigated in detail. Active Ti of Ti6Al4V alloy dissolved into molten filler metal and reacted with ZrO{sub 2} ceramic to form a continuous TiO reaction layer, which played an important role in brazing. Various reaction phases including Ti{sub 2}Ni, Ti{sub 5}Si{sub 3} and ?-Ti were formed in brazed joints. With an increasing of brazing temperature, the TiO layer thickened gradually while the Ti{sub 2}Ni amount reduced. Shear test indicated that brazed joints tend to fracture at the interface between ZrO{sub 2} ceramic and brazing seam or Ti{sub 2}Ni intermetallic layer. The maximum average shear strength reached 284.6 MPa when brazed at 1025 C for 10 min. - Graphical Abstract: Interfacial microstructure of ZrO{sub 2}/TC4 joint brazed using NiCrSiB amorphous filler foil was: ZrO{sub 2}/TiO/Ti{sub 2}Ni + ?-Ti + Ti{sub 5}Si{sub 3}/?-Ti/Widmansttten structure/TC4. - Highlights: Brazing of ZrO{sub 2} ceramic and Ti-6Al-4V alloy was achieved. Interfacial microstructure was TiO/Ti{sub 2}Ni + ? + Ti{sub 5}Si{sub 3}/?/Widmansttten structure. The formation of TiO produced the darkening effect of ZrO{sub 2} ceramic. The highest joining strength of 284.6MPa was obtained.

  11. Composite WO3/TiO2 nanostructures for high electrochromic activity

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Reyes-Gil, Karla R.; Stephens, Zachary D.; Stavila, Vitalie; Robinson, David B.

    2015-01-06

    A composite material consisting of TiO2 nanotubes (NT) with WO3 electrodeposited on its surface has been fabricated, detached from its Ti substrate, and attached to a fluorine-doped tin oxide (FTO) film on glass for application to electrochromic (EC) reactions. Several adhesion layers were tested, finding that a paste of TiO2 made from commercially available TiO2 nanoparticles creates an interface for the TiO2 NT film to attach to the FTO glass, which is conductive and does not cause solution-phase ions in an electrolyte to bind irreversibly with the material. The effect of NT length and WO3 concentration on the EC performancemore » were studied. As a result, the composite WO3/TiO2 nanostructures showed higher ion storage capacity, better stability, enhanced EC contrast, and longer memory time compared with the pure WO3 and TiO2 materials« less

  12. Nanoscale compositional analysis of NiTi shape memory alloy films deposited by DC magnetron sputtering

    SciTech Connect (OSTI)

    Sharma, S. K.; Mohan, S.; Bysakh, S.; Kumar, A.; Kamat, S. V.

    2013-11-15

    The formation of surface oxide layer as well as compositional changes along the thickness for NiTi shape memory alloy thin films deposited by direct current magnetron sputtering at substrate temperature of 300 C in the as-deposited condition as well as in the postannealed (at 600 C) condition have been thoroughly studied by using secondary ion mass spectroscopy, x-ray photoelectron spectroscopy, and scanning transmission electron microscopy-energy dispersive x-ray spectroscopy techniques. Formation of titanium oxide (predominantly titanium dioxide) layer was observed in both as-deposited and postannealed NiTi films, although the oxide layer was much thinner (8 nm) in as-deposited condition. The depletion of Ti and enrichment of Ni below the oxide layer in postannealed films also resulted in the formation of a graded microstructure consisting of titanium oxide, Ni{sub 3}Ti, and B2 NiTi. A uniform composition of B2 NiTi was obtained in the postannealed film only below a depth of 200250 nm from the surface. Postannealed film also exhibited formation of a ternary silicide (Ni{sub x}Ti{sub y}Si) at the filmsubstrate interface, whereas no silicide was seen in the as-deposited film. The formation of silicide also caused a depletion of Ni in the film in a region ?250300 nm just above the film substrate interface.

  13. Photo-oxidative degradation of TiO{sub 2}/polypropylene films

    SciTech Connect (OSTI)

    Garca-Montelongo, X.L.; Martnez-de la Cruz, A.; Vzquez-Rodrguez, S.; Torres-Martnez, Leticia M.

    2014-03-01

    Graphical abstract: - Highlights: Photo-oxidative degradation of polypropylene is accelerated by TiO{sub 2} incorporation. Weight loss, FTIR, SEM and GPC shown high degree of degradation of polypropylene. A mechanism of the photo-degradation of polypropylene by TiO{sub 2} is proposed. - Abstract: Photo-oxidative degradation of polypropylene films with TiO{sub 2} nanoparticles incorporated was studied in a chamber of weathering with Xenon lamps as irradiation source. TiO{sub 2} powder with crystalline structure of anatase was synthesized by thermal treatments at 400 and 500 C starting from a precursor material obtained by solgel method. Composites of TiO{sub 2}/polypropylene were prepared with 0.1, 0.5 and 1.0 wt% of TiO{sub 2}. The mixture of components was performed using a twin screw extruder, the resulting material was pelletized by mechanical fragmenting and then hot-pressed in order to form polypropylene films with TiO{sub 2} dispersed homogeneously. Photo-oxidative degradation process was followed by visual inspection, weight loss of films, scanning electron microscopy (SEM), infrared spectroscopy with Fourier transformed (FTIR), and gel permeation chromatography (GPC)

  14. Graphene oxide modified TiO2 nanotube arrays?enhanced visible light photoelectrochemical properties

    SciTech Connect (OSTI)

    Song, Peng; Zhang, Xiao-Yan; Sun, Mingxun; Cui, Xiao-Li; Lin, Yuehe

    2012-03-01

    Novel nanocomposite films based on graphene oxide (GO) and TiO{sub 2} nanotube arrays were synthesized by assembling GO on the surface of self-organized TiO{sub 2} nanotube arrays through a simple assembling method. The composite films were characterized with field emission scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and UV-vis diffuse reflectance spectroscopy. Photoelectrochemical properties of the composite nanotube arrays were investigated under visible light illumination. Remarkably enhanced visible light photoelectrochemical response was observed for the GO decorated TiO{sub 2} nanotube composite electrode compared with pristine TiO{sub 2} nanotube arrays. Sensitizing effect of GO on the photoelectrochemical response of TiO{sub 2} nanotube arrays was demonstrated and about 15 times enhanced maximum photoconversion efficiency was obtained with the presence of GO. Enhanced photocatalytic activity of TiO{sub 2} nanotube arrays towards degradation of methyl blue was also demonstrated after modification of GO. The results presented here demonstrate GO to be efficient for the improvement of utilization of visible light for TiO{sub 2} nanotube arrays.

  15. Location Of Hole And Electron Traps On Nanocrystalline Anatase TiO2

    SciTech Connect (OSTI)

    Mercado, Candy C.; Knorr, Fritz J.; McHale, Jeanne L.; Usmani, Shirin M.; Ichimura, Andrew S.; Saraf, Laxmikant V.

    2012-05-17

    The defect photoluminescence from TiO2 nanoparticles in the anatase phase is reported for nanosheets which expose predominantly (001) surfaces, and compared to that from conventional anatase nanoparticles which expose mostly (101) surfaces. Also reported is the weak defect photoluminescence of TiO2 nanotubes, which we find using electron back-scattered diffraction to consist of walls which expose (110) and (100) facets. The nanotubes exhibit photoluminescence that is blue-shifted and much weaker than that from conventional TiO2 nanoparticles. Despite the preponderance of (001) surfaces in the nanosheet samples, they exhibit photoluminescence similar to that of conventional nanoparticles. We assign the broad visible photoluminescence of anatase nanoparticles to two overlapping distributions: hole trap emission associated with oxygen vacancies on (101) exposed surfaces, which peaks in the green, and a broader emission extending into the red which results from electron traps on under-coordinated titanium atoms, which are prevalent on (001) facets. The results of this study suggest how morphology of TiO2 nanoparticles could be optimized to control the distribution and activity of surface traps. Our results also shed light on the mechanism by which the TiCl4 surface treatment heals traps on anatase and mixed-phase TiO2 films, and reveals distinct differences in the trap-state distributions of TiO2 nanoparticles and nanotubes. The molecular basis for electron and hole traps and their spatial separation on different facets is discussed.

  16. Direct Evidence of Lithium-Induced Atomic Ordering in Amorphous TiO2 Nanotubes

    SciTech Connect (OSTI)

    Gao, Qi; Gu, Meng; Nie, Anmin; Mashayek, Farzad; Wang, Chong M.; Odegard, Gregory M.; Shahbazian-Yassar, Reza

    2014-01-27

    In this paper, we report the first direct chemical and imaging evidence of lithium-induced atomic ordering in amorphous TiO2 nanomaterials and propose new reaction mechanisms that contradict the many works in the published literature on the lithiation behavior of these materials. The lithiation process was conducted in situ inside an atomic resolution transmission electron microscope. Our results indicate that the lithiation started with the valence reduction of Ti4+ to Ti3+ leading to a LixTiO2 intercalation compound. The continued intercalation of Li ions in TiO2 nanotubes triggered an amorphous to crystalline phase transformation. The crystals were formed as nano-islands and identified to be Li2Ti2O4 with cubic structure (a = 8.375 ). The tendency for the formation of these crystals was verified with density functional theory (DFT) simulations. The size of the crystalline islands provides a characteristic length scale (?5 nm) at which the atomic bonding configuration has been changed within a short time period. This phase transformation is associated with local inhomogeneities in Li distribution. On the basis of these observations, a new reaction mechanism is proposed to explain the first cycle lithiation behavior in amorphous TiO2 nanotubes.

  17. Effect of the top electrode materials on the resistive switching characteristics of TiO{sub 2} thin film

    SciTech Connect (OSTI)

    Oh, Sang Chul; Jung, Ho Yong; Lee, Heon

    2011-06-15

    Various metals, such as Pt, stainless steel (SUS), Al, Ni, and Ti, were used as a top electrode (TE) to evaluate the dependency of the resistive switching characteristics on the TE of the metal/TiO{sub 2}/Pt structure. The variation of the chemical composition of TiO{sub 2} in the metal/TiO{sub 2}/Pt structure before and after switching was examined to identify the factors affecting the resistive switching characteristics of the samples with various TE materials. In the case of TE/TiO{sub 2}/Pt structures showing unstable resistive switching behavior, e.g., those with the Al, Ni, and Ti TEs, secondary ion mass spectrometry revealed an increase in the oxygen concentration at the interface area between the TE metal and TiO{sub 2}. This suggests that the oxidation reaction at the interface between the TE metal and TiO{sub 2} might cause the TE/TiO{sub 2}/Pt structure to exhibit unstable resistive switching characteristics. According to these results, the oxidation reaction at the interface between the metal TE and TiO{sub 2} thin film is a primary factor affecting the resistive switching characteristics of TiO{sub 2}-based Resistive Random Access Memory devices.

  18. Atomic structure of nanometer-sized amorphous TiO2

    SciTech Connect (OSTI)

    Zhang, H.; Chen, B.; Banfield, J.F.; Waychunas, G.A.

    2008-10-15

    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 (PDF) derived from Fourier transform of the WAXS data was used for reverse Monte Carlo (RMC) simulations of the atomic structure of the amorphous TiO{sub 2} nanoparticles. Molecular dynamics simulations were used to generate input structures for the RMC. X-ray absorption spectroscopy (XAS) simulations were used to screen candidate structures obtained from the RMC by comparing with experimental XAS data. The structure model that best describes both the WAXS and XAS data shows that an amorphous TiO{sub 2} particle consists of a highly distorted shell and a small strained anatase-like crystalline core. The average coordination number of Ti is 5.3 and most Ti-O bonds are populated around 1.940 {angstrom}. Relative to bulk TiO{sub 2}, the reduction of the coordination number is primarily due to the truncation of the Ti-O octahedra at the amorphous nanoparticle surface and the shortening of the Ti-O bond length to the bond contraction in the distorted shell. The preexistence of the anatase-like core may be critical to the formation of single-phase nanocrystalline anatase in crystallization of amorphous TiO{sub 2} upon heating.

  19. Electrochromism in sol-gel deposited TiO(sub 2) films

    SciTech Connect (OSTI)

    Bell, J.M.; Barczynska, J.; Evans, L.A.; MacDonald, K.A.; Wang, J.; Green, D.C.; Smith, G.B.

    1994-12-31

    Electrochromism in sol-gel deposited TiO{sub 2} films and films containing TiO{sub 2} and WO{sub 3} has been observed. The films are deposited by dip-coating from a precursor containing titanium isopropoxide in ethanol or titanium propoxide in ethanol, and after deposition the films are heat treated to between 250 C and 300 C. The films do not show any signs of crystallinity. However substantial coloration is observed using Li{sup +} ions in a non-aqueous electrolyte, both in pure TiO{sub 2} films and in mixed metal oxide films (WO{sub 3}:TiO{sub 2}), although the voltage required to produce coloration is different in the two cases. Results will be presented detailing the optical switching and charge transport properties of the films during cyclic voltammetry. These results will be used to compare the performance of the TiO{sub 2} films with other electrochromics. The TiO{sub 2} and mixed metal films all color cathodically, and the colored state is a neutral greyish color for TiO{sub 2}, while the bleached state is transparent and colorless. Results on coloration efficiency and the stability under repeated electrochemical cycling will also be presented. The neutral color of the TiO{sub 2} films and mixed-metal films means that electrochromic windows based on TiO{sub 2} may have significant advantages over WO{sub 3}-based windows. A detailed analysis of the optical properties of the colored state of the films will be presented. The dynamics of coloration for these films is also under investigation, and preliminary results will be presented.

  20. Efficient photocatalytic degradation of gaseous formaldehyde by the TiO{sub 2}/tourmaline composites

    SciTech Connect (OSTI)

    Zhang, Gaoke Qin, Xi

    2013-10-15

    Graphical abstract: - Highlights: The TiO{sub 2}/tourmaline composites were prepared by a solgel method. The composites exhibited excellent photocatalytic activity and good stability. The physicochemical property of tourmaline may be favor for the degradation of HCHO. The mixed-phase of anatase and rutile TiO{sub 2} may be favor for the degradation of HCHO. - Abstract: The TiO{sub 2} supported tourmaline composites were prepared by a solgel method and used as a photocatalyst for the degradation of formaldehyde (HCHO). The composites were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), N{sub 2} adsorptiondesorption, Fourier transform infrared (FT-IR) spectroscopy and UVvis diffuse reflectance spectroscopy (UVvis DRS). The results indicate that the mixed-phase of anatase and rutile exists in the TiO{sub 2}/tourmaline composites. The specific surface area of the TiO{sub 2}/tourmaline composites is much higher than that of the pure TiO{sub 2}. The TiO{sub 2}/tourmaline composites exhibited excellent photocatalytic activity for the degradation of HCHO, which was 6 times higher than that of the pure TiO{sub 2}. Moreover, the excellent photocatalytic activity of the composites was fully maintained after five photocatalytic cycles, which may be attributed to the physicochemical property of tourmaline and the mixed-phase of anatase and rutile in the TiO{sub 2}/tourmaline composites.

  1. Giant strain with ultra-low hysteresis and high temperature stability in grain oriented lead-free K₀̣₅Bi₀̣₅TiO₃-BaTiO₃-Na₀̣₅Bi₀̣₅TiO₃ piezoelectric materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Maurya, Deepam; Zhou, Yuan; Wang, Yaojin; Yan, Yongke; Li, Jiefang; Viehland, Dwight; Priya, Shashank

    2015-02-26

    We synthesized grain-oriented lead-free piezoelectric materials in (K₀̣₅Bi₀̣₅TiO₃-BaTiO₃-xNa₀̣₅Bi₀̣₅TiO₃ (KBT-BT-NBT) system with high degree of texturing along the [001]c (c-cubic) crystallographic orientation. We demonstrate giant field induced strain (~0.48%) with an ultra-low hysteresis along with enhanced piezoelectric response (d₃₃ ~ 190pC/N) and high temperature stability (~160°C). Transmission electron microscopy (TEM) and piezoresponse force microscopy (PFM) results demonstrate smaller size highly ordered domain structure in grain-oriented specimen relative to the conventional polycrystalline ceramics. The grain oriented specimens exhibited a high degree of non-180° domain switching, in comparison to the randomly axed ones. These results indicate the effective solution to the lead-free piezoelectricmore » materials.« less

  2. Giant strain with ultra-low hysteresis and high temperature stability in grain oriented lead-free K???Bi???TiO?-BaTiO?-Na???Bi???TiO? piezoelectric materials

    SciTech Connect (OSTI)

    Maurya, Deepam; Zhou, Yuan; Wang, Yaojin; Yan, Yongke; Li, Jiefang; Viehland, Dwight; Priya, Shashank

    2015-02-26

    We synthesized grain-oriented lead-free piezoelectric materials in (K???Bi???TiO?-BaTiO?-xNa???Bi???TiO? (KBT-BT-NBT) system with high degree of texturing along the [001]c (c-cubic) crystallographic orientation. We demonstrate giant field induced strain (~0.48%) with an ultra-low hysteresis along with enhanced piezoelectric response (d?? ~ 190pC/N) and high temperature stability (~160C). Transmission electron microscopy (TEM) and piezoresponse force microscopy (PFM) results demonstrate smaller size highly ordered domain structure in grain-oriented specimen relative to the conventional polycrystalline ceramics. The grain oriented specimens exhibited a high degree of non-180 domain switching, in comparison to the randomly axed ones. These results indicate the effective solution to the lead-free piezoelectric materials.

  3. Structural evolution in Ti-Cu-Ni metallic glasses during heating

    SciTech Connect (OSTI)

    Gargarella, P.; Pauly, S.; Stoica, M.; Khn, U.; Vaughan, G.; Afonso, C. R. M.; Eckert, J.

    2015-01-01

    The structural evolution of Ti{sub 50}Cu{sub 43}Ni{sub 7} and Ti{sub 55}Cu{sub 35}Ni{sub 10} metallic glasses during heating was investigated by in-situ synchrotron X-ray diffraction. The width of the most intense diffraction maximum of the glassy phase decreases slightly during relaxation below the glass transition temperature. Significant structural changes only occur above the glass transition manifesting in a change in the respective peak positions. At even higher temperatures, nanocrystals of the shape memory B2-Ti(Cu,Ni) phase precipitate, and their small size hampers the occurrence of a martensitic transformation.

  4. Effects of aging on the characteristics of TiNiPd shape memory alloy thin films

    SciTech Connect (OSTI)

    Zhang Congchun

    2008-07-15

    TiNiPd thin films have been deposited on glass substrate using R.F. magnetron sputtering. Effects of annealing and aging on the microstructure, phase transformation behaviors and shape memory effects of these thin films have been studied by X-ray diffractometry, differential scanning calorimeter, tensile tests and internal friction characteristics. The TiNiPd thin films annealed at 750 deg. C exhibit uniform martensite/austenite transformations and shape memory effect. Aging at 450 deg. C for 1 h improved the uniformity of transformations and shape memory effect. Long time aging decreased transformation temperatures and increased the brittleness of TiNiPd thin films.

  5. On the origins of hardness of Cu–TiN nanolayered composites

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Pathak, S.; Li, N.; Maeder, X.; Hoagland, R. G.; Baldwin, J. K.; Michler, J.; Misra, A.; Wang, J.; Mara, N. A.

    2015-07-18

    We investigated the mechanical response of physical vapor deposited Cu–TiN nanolayered composites of varying layer thicknesses from 5 nm to 200 nm. Both the Cu and TiN layers were found to consist of single phase nanometer sized grains. The grain sizes in the Cu and TiN layers, measured using transmission electron microscopy and X-ray diffraction, were found to be comparable to or smaller than their respective layer thicknesses. Indentation hardness testing revealed that the hardness of such nanolayered composites exhibits a weak dependence on the layer thickness but is more correlated to their grain size.

  6. Photo-induced wettability of TiO{sub 2} film with Au buffer layer

    SciTech Connect (OSTI)

    Purkayastha, Debarun Dhar; Sangani, L. D. Varma; Krishna, M. Ghanashyam; Madhurima, V.

    2014-04-24

    The effect of thickness of Au buffer layer (15-25 nm) between TiO{sub 2} film and substrate on the wettability of TiO{sub 2} films is reported. TiO{sub 2} films grown on Au buffer layer have a higher contact angle of 96-;100 as compared to 47.6o for the film grown without buffer layer. The transition from hydrophobicity to hydrophilicity under UV irradiation occurs within 10 min. for the buffer layered films whereas it is almost 30 min. for the film grown without buffer layer. The enhanced photo induced hydrophilicity is shown to be surface energy driven.

  7. Complex catalytic behaviors of CuTiOx mixed-oxide during CO oxidation

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Complex catalytic behaviors of CuTiOx mixed-oxide during CO oxidation Citation Details In-Document Search This content will become publicly available on September 21, 2016 Title: Complex catalytic behaviors of CuTiOx mixed-oxide during CO oxidation Mixed metal oxides have attracted considerable attention in heterogeneous catalysis due to the unique stability, reactivity, and selectivity. Here, the activity and stability of the CuTiOx monolayer film

  8. Doping of TiO 2 Polymorphs for Altered Optical and Photocatalytic Properties

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nie, Xiliang; Zhuo, Shuping; Maeng, Gloria; Sohlberg, Karl

    2009-01-01

    Tmore » his paper reviews recent investigations of the influence of dopants on the optical properties of TiO 2 polymorphs. The common undoped polymorphs of TiO 2 are discussed and compared. The results of recent doping efforts are tabulated, and discussed in the context of doping by elements of the same chemical group. Dopant effects on the band gap and photocatalytic activity are interpreted with reference to a simple qualitative picture of the TiO 2 electronic structure, which is supported with first-principles calculations.« less

  9. Transparent TiO2 nanotube array photoelectrodes prepared via two-step anodization

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, Jin Young; Zhu, Kai; Neale, Nathan R.; Frank, Arthur J.

    2014-04-04

    Two-step anodization of transparent TiO2 nanotube arrays has been demonstrated with aid of a Nb-doped TiO2 buffer layer deposited between the Ti layer and TCO substrate. Enhanced physical adhesion and electrochemical stability provided by the buffer layer has been found to be important for successful implementation of the two-step anodization process. As a result, with the proposed approach, the morphology and thickness of NT arrays could be controlled very precisely, which in turn, influenced their optical and photoelectrochemical properties.

  10. Doping ofTiO2Polymorphs for Altered Optical and Photocatalytic Properties

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Nie, Xiliang; Zhuo, Shuping; Maeng, Gloria; Sohlberg, Karl

    2009-01-01

    This paper reviews recent investigations of the influence of dopants on the optical properties ofTiO2polymorphs. The common undoped polymorphs ofTiO2are discussed and compared. The results of recent doping efforts are tabulated, and discussed in the context of doping by elements of the same chemical group. Dopant effects on the band gap and photocatalytic activity are interpreted with reference to a simple qualitative picture of theTiO2electronic structure, which is supported with first-principles calculations.

  11. Size-Dependent Pressure-Induced Amorphization in Nanoscale TiO{sub 2}

    Office of Scientific and Technical Information (OSTI)

    (Journal Article) | SciTech Connect Size-Dependent Pressure-Induced Amorphization in Nanoscale TiO{sub 2} Citation Details In-Document Search Title: Size-Dependent Pressure-Induced Amorphization in Nanoscale TiO{sub 2} We investigated the size-dependent high-pressure phase transition behavior of nanocrystalline anatase TiO{sub 2} with synchrotron x-ray diffraction and Raman spectroscopy to 45 GPa at ambient temperature. Pressure-induced amorphization results in a high-density amorphous (HDA)

  12. TRENDS IN {sup 44}Ti AND {sup 56}Ni FROM CORE-COLLAPSE SUPERNOVAE (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect TRENDS IN {sup 44}Ti AND {sup 56}Ni FROM CORE-COLLAPSE SUPERNOVAE Citation Details In-Document Search Title: TRENDS IN {sup 44}Ti AND {sup 56}Ni FROM CORE-COLLAPSE SUPERNOVAE We compare the yields of {sup 44}Ti and {sup 56}Ni produced from post-processing the thermodynamic trajectories from three different core-collapse models-a Cassiopeia A progenitor, a double shock hypernova progenitor, and a rotating two-dimensional explosion-with the yields from exponential

  13. Thickness-dependent coherent phonon frequency in ultrathin FeSe/SrTiO3

    Office of Scientific and Technical Information (OSTI)

    films (Journal Article) | SciTech Connect Thickness-dependent coherent phonon frequency in ultrathin FeSe/SrTiO3 films Citation Details In-Document Search Title: Thickness-dependent coherent phonon frequency in ultrathin FeSe/SrTiO3 films Ultrathin FeSe films grown on SrTiO3 substrates are a recent milestone in atomic material engineering due to their important role in understanding unconventional superconductivity in Fe-based materials. By using femtosecond time- and angle-resolved

  14. Catalytic Effect of Ti for Hydrogen Cycling in NaAlH4 | Department of

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Energy Catalytic Effect of Ti for Hydrogen Cycling in NaAlH4 Catalytic Effect of Ti for Hydrogen Cycling in NaAlH4 A presentation about how hydrogen can be reversibly absorbed and desorbed from NaAlH4 under moderate conditions by the addition of catalysts. PDF icon catalytic_effect_of_ti.pdf More Documents & Publications Final Report for the DOE Metal Hydride Center of Excellence Effects of Point Defects and Impurities on Kinetics in NaAlH4 Prediction of New Hydrogen Storage Compounds

  15. Model NbTi Helical Solenoid Fabrication and Test Results

    SciTech Connect (OSTI)

    Andreev, N.; Barzi, E.; Chlachidze, G.; Evbota, D.; Kashikhin, V.S.; Kashikhin, V.V.; Lamm, M.J.; Makarov, A.; Novitski, I.; Orris, D.F.; Tartaglia, M.A.; /Fermilab

    2011-09-01

    A program to develop model magnets for a helical cooling channel is under way at Fermilab. In the first steps of a planned sequence of magnets, two four-coil helical solenoid models with 300 mm aperture have been fabricated and tested. These two models, HSM01 and HSM02, used insulated NbTi Rutherford cable wound onto stainless steel rings with spliceless transitions between coils. Strip heaters were included for quench protection of each coil, and the coils were epoxy-impregnated after winding inside the support structures. Based on the results of the first model the second model was made using a cable with optimized cross-section, improved winding and epoxy-impregnation procedures, enhanced ground insulation, and included heat exchange tubing for a test of conduction cooling. We report on the results and lessons learned from fabrication and tests of these two models.

  16. Controlling the pH of acid cheese whey in a two-stage anaerobic digester with sodium hydroxide

    SciTech Connect (OSTI)

    Ghaly, A.E.; Ramkumar, D.R.

    1999-07-01

    Anaerobic digestion of cheese whey offers a two-fold benefit: pollution potential reduction and biogas production. The biogas, as an energy source, could be used to reduce the consumption of traditional fuels in the cheese plant. However, as a result of little or no buffering capacity of whey, the pH of the anaerobic digester drops drastically and the process is inhibited. In this study, the effect of controlling the pH of the second chamber of a two-stage, 150 L anaerobic digester operating on cheese whey on the quality and quantity of biogas and the pollution potential reduction, was investigated using sodium hydroxide. The digester was operated at a temperature of 35 C and a hydraulic retention time of 15 days for three runs (no pH control, pH control with no reseeding, and ph control with reseeding) each lasting 50 days. The results indicated that operating the digester without pH control resulted in a low pH (3.3) which inhibited the methanogenic bacteria. The inhibition was irreversible and the digester did not recover (no methane production) when the pH was restored to 7.0 without reseeding, as the observed increased gas production was a false indication of recovery because the gas was mainly carbon dioxide. The addition of base resulted in a total alkalinity of 12,000 mg/L as CaCO{sub 3}. When the system was reseeded and the pH controlled, the total volatile acid concentration was 15,100 mg/L (as acetic acid), with acetic (28%), propionic (21%), butyric (25%), valeric (8%), and caproic (15%) acids as the major constituents. The biogas production was 62.6 L/d (0.84 m{sup 3}/m{sup 3}/d) and the methane content was 60.7%. Reductions of 27.3, 30.4 and 23.3% in the total solids, chemical oxygen demand and total kjeldahl nitrogen were obtained, respectively. The ammonium nitrogen content increased significantly (140%).

  17. Molecular Hydrogen Formation from Proximal Glycol Pairs on TiO2(110)

    SciTech Connect (OSTI)

    Chen, Long; Li, Zhenjun; Smith, R. Scott; Kay, Bruce D.; Dohnalek, Zdenek

    2014-04-16

    Understanding hydrogen formation on TiO2 surfaces is of great importance as it could provide fundamental insight into water splitting for hydrogen production using solar energy. In this work, hydrogen formation from glycols having different numbers of methyl end-groups have been studied using temperature pro-grammed desorption on reduced, hydroxylated, and oxidized TiO2(110) surfaces. The results from OD-labeled glycols demon-strate that gas-phase molecular hydrogen originates exclusively from glycol hydroxyl groups. The yield is controlled by a combi-nation of glycol coverage, steric hindrance, TiO2(110) order and the amount of subsurface charge. Combined, these results show that proximal pairs of hydroxyl aligned glycol molecules and subsurface charge are required to maximize the yield of this redox reaction. These findings highlight the importance of geometric and electronic effects in hydrogen formation from adsorbates on TiO2(110).

  18. Amphoteric doping of praseodymium Pr3+ in SrTiO3 grain boundaries

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, H.; Lee, H. S.; Kotula, P. G.; Sato, Y.; Ikuhara, Y.; Browning, N. D.

    2015-03-26

    Charge Compensation in rare-earth Praseodymium (Pr3+) doped SrTiO3 plays an important role in determining the overall photoluminescence properties of the system. Here, the Pr3+ doping behavior in SrTiO3 grain boundaries (GBs) is analyzed using aberration corrected scanning transmission electron microscopy (STEM). The presence of Pr3+ induces structure variations and changes the statistical prevalence of GB structures. In contrast to the assumption that Pr3+ substitutes for A site as expected in the bulk, Pr3+ is found to substitute both Sr and Ti sites inside GBs with the highest concentration in the Ti sites. As a result, this amphoteric doping behavior inmore »the boundary plane is further confirmed by first principles theoretical calculations.« less

  19. Process for producing Ti-Cr-Al-O thin film resistors

    DOE Patents [OSTI]

    Jankowski, Alan F. (Livermore, CA); Schmid, Anthony P. (Solana Beach, CA)

    2001-01-01

    Thin films of Ti-Cr-Al-O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti-Cr-Al-O film <1 .mu.m thick. The film resistivity can be discretely selected through control of the target composition and the deposition parameters. The application of Ti-Cr-Al-O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti-Cr-Al-O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

  20. Flat panel display using Ti-Cr-Al-O thin film

    DOE Patents [OSTI]

    Jankowski, Alan F. (Livermore, CA); Schmid, Anthony P. (Solan Beach, CA)

    2002-01-01

    Thin films of Ti--Cr--Al--O are used as a resistor material. The films are rf sputter deposited from ceramic targets using a reactive working gas mixture of Ar and O.sub.2. Resistivity values from 10.sup.4 to 10.sup.10 Ohm-cm have been measured for Ti--Cr--Al--O film <1 .mu.m thick. The film resistivity can be discretely selected through control of the target composition and the deposition parameters. The application of Ti--Cr--Al--O as a thin film resistor has been found to be thermodynamically stable, unlike other metal-oxide films. The Ti--Cr--Al--O film can be used as a vertical or lateral resistor, for example, as a layer beneath a field emission cathode in a flat panel display; or used to control surface emissivity, for example, as a coating on an insulating material such as vertical wall supports in flat panel displays.

  1. Ability of TiO2(110) Surface to Be Fully Hydroxylated and Fully...

    Office of Scientific and Technical Information (OSTI)

    The resulting hydroxylation can significantly alter its surface properties. While behavior of single, isolated OH species on the model metal oxide surface of rutile TiO2(110) is ...

  2. Amphoteric doping of praseodymium Pr3+ in SrTiO3 grain boundaries

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, H.; Lee, H. S.; Kotula, P. G.; Sato, Y.; Ikuhara, Y.; Browning, N. D.

    2015-03-26

    Charge Compensation in rare-earth Praseodymium (Pr3+) doped SrTiO3 plays an important role in determining the overall photoluminescence properties of the system. Here, the Pr3+ doping behavior in SrTiO3 grain boundaries (GBs) is analyzed using aberration corrected scanning transmission electron microscopy (STEM). The presence of Pr3+ induces structure variations and changes the statistical prevalence of GB structures. In contrast to the assumption that Pr3+ substitutes for A site as expected in the bulk, Pr3+ is found to substitute both Sr and Ti sites inside GBs with the highest concentration in the Ti sites. As a result, this amphoteric doping behavior inmore » the boundary plane is further confirmed by first principles theoretical calculations.« less

  3. Recyclability study on Inconel 718 and Ti-6Al-4V powders for...

    Office of Scientific and Technical Information (OSTI)

    that govern the powder reuse times. This work presents the results from a recyclability study conducted on Inconel 718 and Ti-6Al-4V powders. It has been found that the Inconel...

  4. A New Method of Low Cost Production of Ti Alloys to Reduce Energy...

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    by sintering of TiH 2 in (a) hydrogen, (b) vacuum (SEM ) Refine grain sizes by controlling H 2 content and phase transformation in as-sintered state High density - >99% ...

  5. Role of polaron hopping in leakage current behavior of a SrTiO...

    Office of Scientific and Technical Information (OSTI)

    m thickness for SrTiOsub 3 layer, and a temperature of 150 C. The applied voltage resulted in the migration of ionic defects (oxygen vacancies) from anode towards cathode. ...

  6. Adhesion strength of sputtered TiAlN-coated WC insert tool

    SciTech Connect (OSTI)

    Budi, Esmar; Razali, M. Mohd.; Nizam, A. R. Md.

    2013-09-09

    The adhesion strength of TiAlN coating that deposited by using DC magnetron sputtering on WC insert tool are studied. TiAlN coating are deposited on Tungsten Carbide (WC) insert tool by varying negatively substrate bias from 79 to 221 volt and nitrogen flow rate from 30 to 72 sccm. The adhesion strength are obtained by using Rockwell indentation test method with a Brale diamond at applied load of 60,100 and 150 kgf. The lateral diameter of indentation is plotted on three different applied loads and the adhesion strength of TiAlN coating was obtained from the curved slopes at 100 and 150 kgf. The lower curve slop indicated better adhesion strength. The results shows that the adhesion strength of sputterred TiAlN coating tend to increase as the negatively substrate bias and nitrogen flow rate are increased.

  7. TiN coated aluminum electrodes for DC high voltage electron guns

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mamun, Md Abdullah A.; Elmustafa, Abdelmageed A.; Taus, Rhys; Forman, Eric; Poelker, Matthew

    2015-05-01

    Preparing electrodes made of metals like stainless steel, for use inside DC high voltage electron guns, is a labor-intensive and time-consuming process. In this paper, the authors report the exceptional high voltage performance of aluminum electrodes coated with hard titanium nitride (TiN). The aluminum electrodes were comparatively easy to manufacture and required only hours of mechanical polishing using silicon carbide paper, prior to coating with TiN by a commercial vendor. The high voltage performance of three TiN-coated aluminum electrodes, before and after gas conditioning with helium, was compared to that of bare aluminum electrodes, and electrodes manufactured from titanium alloymore » (Ti-6AI-4V). Following gas conditioning, each TiN-coated aluminum electrode reached -225 kV bias voltage while generating less than 100 pA of field emission (<10 pA) using a 40 mm cathode/anode gap, corresponding to field strength of 13.7 MV/m. Smaller gaps were studied to evaluate electrode performance at higher field strength with the best performing TiN-coated aluminum electrode reaching ~22.5 MV/m with field emission less than 100 pA. These results were comparable to those obtained from our best-performing electrodes manufactured from stainless steel, titanium alloy and niobium, as reported in references cited below. The TiN coating provided a very smooth surface and with mechanical properties of the coating (hardness and modulus) superior to those of stainless steel, titanium-alloy, and niobium electrodes. These features likely contributed to the improved high voltage performance of the TiN-coated aluminum electrodes.« less

  8. Polycrystalline TiO2(B) Nanosheet Films Deposited via Langmuir-Blodgett

    Office of Scientific and Technical Information (OSTI)

    Method. (Conference) | SciTech Connect Polycrystalline TiO2(B) Nanosheet Films Deposited via Langmuir-Blodgett Method. Citation Details In-Document Search Title: Polycrystalline TiO2(B) Nanosheet Films Deposited via Langmuir-Blodgett Method. Abstract not provided. Authors: Biedermann, Laura ; Kotula, Paul Gabriel ; Beechem Iii, Thomas Edwin ; Chan, Calvin ; Dylla, Anthony ; Stevenson, Keith Publication Date: 2014-03-01 OSTI Identifier: 1140906 Report Number(s): SAND2014-1720C 505110 DOE

  9. Mechanisms of Oriented Attachment of TiO2 Nanocrystals in Vacuum and Humid

    Office of Scientific and Technical Information (OSTI)

    Environments: Reactive Molecular Dynamics (Journal Article) | SciTech Connect Mechanisms of Oriented Attachment of TiO2 Nanocrystals in Vacuum and Humid Environments: Reactive Molecular Dynamics Citation Details In-Document Search Title: Mechanisms of Oriented Attachment of TiO2 Nanocrystals in Vacuum and Humid Environments: Reactive Molecular Dynamics Authors: Raju, Muralikrishna [1] ; Van Duin, Adri C. T. [2] ; Fichthorn, Kristen [1] + Show Author Affiliations Pennsylvania State

  10. Shape-memory transformations of NiTi: Minimum-energy pathways between

    Office of Scientific and Technical Information (OSTI)

    austenite, martensites, and kinetically limited intermediate states (Journal Article) | SciTech Connect Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states Citation Details In-Document Search Title: Shape-memory transformations of NiTi: Minimum-energy pathways between austenite, martensites, and kinetically limited intermediate states × You are accessing a document from the Department of Energy's (DOE)

  11. Direct Epoxidation of Propylene over Stabilized Cu+ Surface Sites on Ti Modified Cu2O

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, X.; Kattel, S.; Xiong, K.; Mudiyanselage, K.; Rykov, S.; Senanayake, S. D.; Rodriguez, J. A.; Liu, P.; Stacchiola, D. J.; Chen, J. G.

    2015-07-17

    Direct propylene epoxidation by O2 is a challenging reaction because of the strong tendency for complete combustion. Results from the current study demonstrate the feasibility to tune the epoxidation selectivity by generating highly dispersed and stabilized Cu+ active sites in a TiCuOx mixed oxide. The TiCuOx surface anchors the key surface intermediate, oxametallacycle, leading to higher selectivity for epoxidation of propylene.

  12. Finite Difference Modeling of Wave Progpagation in Acoustic TiltedTI Media

    Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

    (Journal Article) | SciTech Connect Journal Article: Finite Difference Modeling of Wave Progpagation in Acoustic TiltedTI Media Citation Details In-Document Search Title: Finite Difference Modeling of Wave Progpagation in Acoustic TiltedTI Media × You are accessing a document from the Department of Energy's (DOE) SciTech Connect. This site is a product of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional

  13. Observation of Ti{sup 4+} ions in a high power impulse magnetron sputtering plasma

    SciTech Connect (OSTI)

    Andersson, Joakim; Anders, Andre; Ehiasarian, Arutiun P.

    2008-08-18

    Multiply charged titanium ions including Ti{sup 4+} were observed in high power impulse magnetron sputtering discharges. Mass/charge spectrometry was used to identify metal ion species. Quadruply charged titanium ions were identified by isotope-induced broadening at mass/charge 12. Due to their high potential energy, Ti{sup 4+} ions give a high yield of secondary electrons, which in turn are likely to be responsible for the generation of multiply charged states.

  14. TiN coated aluminum electrodes for DC high voltage electron guns

    SciTech Connect (OSTI)

    Mamun, Md Abdullah A.; Elmustafa, Abdelmageed A.; Taus, Rhys; Forman, Eric; Poelker, Matthew

    2015-05-15

    Preparing electrodes made of metals like stainless steel, for use inside DC high voltage electron guns, is a labor-intensive and time-consuming process. In this paper, the authors report the exceptional high voltage performance of aluminum electrodes coated with hard titanium nitride (TiN). The aluminum electrodes were comparatively easy to manufacture and required only hours of mechanical polishing using silicon carbide paper, prior to coating with TiN by a commercial vendor. The high voltage performance of three TiN-coated aluminum electrodes, before and after gas conditioning with helium, was compared to that of bare aluminum electrodes, and electrodes manufactured from titanium alloy (Ti-6Al-4V). Following gas conditioning, each TiN-coated aluminum electrode reached ?225?kV bias voltage while generating less than 100?pA of field emission (<10?pA) using a 40?mm cathode/anode gap, corresponding to field strength of 13.7?MV/m. Smaller gaps were studied to evaluate electrode performance at higher field strength with the best performing TiN-coated aluminum electrode reaching ?22.5 MV/m with field emission less than 100?pA. These results were comparable to those obtained from our best-performing electrodes manufactured from stainless steel, titanium alloy and niobium, as reported in references cited below. The TiN coating provided a very smooth surface and with mechanical properties of the coating (hardness and modulus) superior to those of stainless steel, titanium-alloy, and niobium electrodes. These features likely contributed to the improved high voltage performance of the TiN-coated aluminum electrodes.

  15. TiN coated aluminum electrodes for DC high voltage electron guns

    SciTech Connect (OSTI)

    Mamun, Md Abdullah A.; Elmustafa, Abdelmageed A.; Taus, Rhys; Forman, Eric; Poelker, Matthew

    2015-05-01

    Preparing electrodes made of metals like stainless steel, for use inside DC high voltage electron guns, is a labor-intensive and time-consuming process. In this paper, the authors report the exceptional high voltage performance of aluminum electrodes coated with hard titanium nitride (TiN). The aluminum electrodes were comparatively easy to manufacture and required only hours of mechanical polishing using silicon carbide paper, prior to coating with TiN by a commercial vendor. The high voltage performance of three TiN-coated aluminum electrodes, before and after gas conditioning with helium, was compared to that of bare aluminum electrodes, and electrodes manufactured from titanium alloy (Ti-6AI-4V). Following gas conditioning, each TiN-coated aluminum electrode reached -225 kV bias voltage while generating less than 100 pA of field emission (<10 pA) using a 40 mm cathode/anode gap, corresponding to field strength of 13.7 MV/m. Smaller gaps were studied to evaluate electrode performance at higher field strength with the best performing TiN-coated aluminum electrode reaching ~22.5 MV/m with field emission less than 100 pA. These results were comparable to those obtained from our best-performing electrodes manufactured from stainless steel, titanium alloy and niobium, as reported in references cited below. The TiN coating provided a very smooth surface and with mechanical properties of the coating (hardness and modulus) superior to those of stainless steel, titanium-alloy, and niobium electrodes. These features likely contributed to the improved high voltage performance of the TiN-coated aluminum electrodes.

  16. Preparation and properties of sliver and nitrogen co-doped TiO{sub 2} photocatalyst

    SciTech Connect (OSTI)

    Zhang, Ying; Zhang, Jin; Zhu, Zhongqi; Yan, Ningning; Liu, Qingju

    2013-11-15

    Graphical abstract: - Highlights: The silver and nitrogen co-doped TiO{sub 2} photocatalysts were prepared and characterized. The light absorption threshold wavelength of AgNTiO{sub 2} is red-shifted to visible light. The recombination of the photo-generated electrons and holes of AgNTiO{sub 2} is inhibited. The photocatalytic activity of AgNTiO{sub 2} is remarkable improved. - Abstract: TiO{sub 2} photocatalysts co-doped with different content of Ag and N were prepared by solgel method combined with microwave chemical method. The samples were analyzed by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), transmission electron microscope (TEM), ultravioletvisible diffuse reflectance spectrum (UVvis) and photo-luminescence emission spectrum (PL). The photocatalytic activity was investigated by photocatalytic degradation of methylene blue (MB) under irradiation of fluorescent lamp. The results indicate that Ag and N co-doping can restrain the increase of grain size, broaden the absorption spectrum to visible light region, and inhibit the recombination of the photo-generated electronhole pairs. Moreover, the photocatalytic activity of AgNTiO{sub 2} in MB degradation is remarkable improved. The degradation rate of the sample with Ag:TiO{sub 2} = 0.05 at%, N:TiO{sub 2} = 18.50 wt% in 5 h is 93.44%, which is much higher than that of Degussa P25 (39.40%)

  17. Singlet-Triplet Excitations in the Unconventional Spin-Peierls TiOBr

    Office of Scientific and Technical Information (OSTI)

    Compound (Journal Article) | SciTech Connect Singlet-Triplet Excitations in the Unconventional Spin-Peierls TiOBr Compound Citation Details In-Document Search Title: Singlet-Triplet Excitations in the Unconventional Spin-Peierls TiOBr Compound Authors: Clancy, J. P. ; Gaulin, B. D. ; Adams, C. P. ; Granroth, G. E. ; Kolesnikov, A. I. ; Sherline, T. E. ; Chou, F. C. Publication Date: 2011-03-18 OSTI Identifier: 1100073 Type: Publisher's Accepted Manuscript Journal Name: Physical Review

  18. The Valence and Coordination of Ti in Olivine and Pyroxene in Ordinary and

    Office of Scientific and Technical Information (OSTI)

    Enstatite Chondrites as a Function of Metamorphic Grade. (Conference) | SciTech Connect Conference: The Valence and Coordination of Ti in Olivine and Pyroxene in Ordinary and Enstatite Chondrites as a Function of Metamorphic Grade. Citation Details In-Document Search Title: The Valence and Coordination of Ti in Olivine and Pyroxene in Ordinary and Enstatite Chondrites as a Function of Metamorphic Grade. Authors: Simon, S.B. ; Sutton, S.R. ; Grossman, L. [1] + Show Author Affiliations (UC)

  19. The kinetics of the [omega] to [alpha] phase transformation in Zr, Ti:

    Office of Scientific and Technical Information (OSTI)

    Analysis of data from shock-recovered samples and atomistic simulations (Journal Article) | SciTech Connect The kinetics of the [omega] to [alpha] phase transformation in Zr, Ti: Analysis of data from shock-recovered samples and atomistic simulations Citation Details In-Document Search Title: The kinetics of the [omega] to [alpha] phase transformation in Zr, Ti: Analysis of data from shock-recovered samples and atomistic simulations Authors: Zong, Hongxiang ; Lookman, Turab ; Ding, Xiangdong

  20. A microbial fuel cell operating at low pH using an acidophile, Acidiphilium cryptum.

    SciTech Connect (OSTI)

    Borole, Abhijeet P; Cesar, Scott A; O'Neill, Hugh Michael; Tsouris, Costas

    2008-01-01

    A microbial fuel cell using an acidophilic microorganism, Acidiphilium cryptum, as the anode biocatalyst was investigated. The mode of electron transfer by this organism to the electrode was studied. Electricity production in the presence of a mediator was demonstrated using its natural electron acceptor, iron, as well as phenosafranin as the electron mediating agent. Production of Fe(II), as a result of iron reduction, at a pH of 4.0 or below was found to support electricity production. Accumulation of the oxidized iron, Fe(III) as a result of electron donation to the electrode, however, restricted higher current output. Addition of nitrilotriacetic acid helped resolve the problem by redissolution of deposited Fe(III). Further, use of phenosafranin as a secondary mediator resulted in improvement in power output. At a cell loading equivalent to OD600 of 1.0, a power output of 12.7 mW/m2 was obtained in a two-chamber air-sparged fuel cell. Potential for direct electron transfer was also investigated but not detected under the conditions studied.

  1. Production of Ni-Cr-Ti-natural fibres composite and investigation of mechanical properties

    SciTech Connect (OSTI)

    Pesmen, G.; Erol, A.

    2015-03-30

    Intermetallic materials such as Ni{sub 2}Ti, Cr{sub 2}Ti are among advanced technology materials that have outstanding mechanical and physical properties for high temperature applications. Especially creep resistance, low density and high hardness properties stand out in such intermetallics. The microstructure, mechanical properties of (%50Ni-%48Cr-%2Ti)-%10Naturel Fibres and (%64Ni-%32Cr-%4Ti)-%10Naturel Fibres powders were investigated using specimens produced by tube furnace sintering at 1000-1200-1400C temperature. A composite consisting of ternary additions, a metallic phase, Ti,Cr and Ni have been prepared under Ar shroud and then tube furnace sintered. XRD, SEM (Scanning Electron Microscope), were investigated to characterize the properties of the specimens. Experimental results carried out for composition (%64Ni-%32Cr-%4Ti)-%10Naturel at 1400C suggest that the best properties as 112.09HV and 5,422g/cm{sup 3} density were obtained at 1400C.

  2. Structural Environment of Nitrogen in N-doped Rutile TiO2(110)

    SciTech Connect (OSTI)

    Henderson, Michael A.; Shutthanandan, V.; Ohsawa, Takeo; Chambers, Scott A.

    2010-12-31

    We employ x-ray photoelectron spectroscopy (XPS), reflection high-energy electron diffraction (RHEED) and nuclear reaction analysis (NRA) to characterize the concentration-dependent structural properties of nitrogen doping into rutile TiO2. High quality N-doped TiO2 were prepared on rutile single crystal TiO2(110) substrates using plasma-assisted molecular beam epitaxy with an electron cyclotron resonance (ECR) plasma and Ti effusive sources. Films with N dopant concentrations at or below 2 at.% exhibited predominately substitutional doping based on NRA data, whereas films with concentrations above this limit resulted in little or no substitutional N and surfaces rich in Ti3+. The binding energy of the N 1s feature in XPS did not readily distinguish between these two extremes in N-doping, rendering features within 0.4 eV of each other and similar peak profiles. Although widely used to characterize the state of N in anion-doped TiO2 materials, we find that XPS is unsuitable for this task.

  3. Structural, morphological and interfacial characterization of Al-Mg/TiC composites

    SciTech Connect (OSTI)

    Contreras, A. . E-mail: acontrer@imp.mx; Angeles-Chavez, C.; Flores, O.; Perez, R.

    2007-08-15

    Morphological and structural characterization of Al-Mg/TiC composites obtained by infiltration process and wetting by the sessile drop technique were studied. Focusing at the interface, wetting of TiC substrates by molten Al-Mg-alloys at 900 deg. C was investigated. Electron probe microanalysis (EPMA) indicated that aluminum carbide (Al{sub 4}C{sub 3}) is formed at the interface and traces of TiAl{sub 3} in the wetting assemblies were detected. Scanning Electron Microscopy (SEM) observations show that TiC particles do not appear to be uniformly attacked to produce a continuous layer of Al{sub 4}C{sub 3} at the interface. Molten Al-Mg-alloys were infiltrated into TiC preforms with flowing argon at a temperature of 900 deg. C. In the composites no reaction phase was observed by SEM. Quantification of the Al phase in the composite was carried out by X-ray diffraction (XRD) and Rietveld analysis. Chemical mapping analyzed by SEM shows that the Al-Mg alloy surrounds TiC particles. In the composites with 20 wt.% of Mg the Al-Mg-{beta} phase was detected through XRD.

  4. Composite WO3/TiO2 nanostructures for high electrochromic activity.

    SciTech Connect (OSTI)

    Reyes, Karla Rosa; Stephens, Zachary Dan.; Robinson, David B.

    2013-05-01

    A composite material consisting of TiO2 nanotubes (NTs) with WO3 electrodeposited homogeneously on its surface has been fabricated, detached from its substrate, and attached to a fluorine-doped tin oxide film on glass for application to electrochromic (EC) reactions. A paste of TiO2 made from commercially available TiO2 nanoparticles creates an interface for the TiO2 NT film to attach to the FTO glass, which is conductive and does not cause solution-phase ions in an electrolyte to bind irreversibly with the material. The effect of NT length on the current density and the EC contrast of the material were studied. The EC redox reaction seen in this material is diffusion- limited, having relatively fast reaction rates at the electrode surface. The composite WO3/TiO2 nanostructures showed higher ion storage capacity, better stability, enhanced EC contrast and longer memory time compared with the pure WO3 and TiO2.

  5. Enhancement of solar photocatalytic detoxification by adsorption of porphyrins onto TiO sub 2

    SciTech Connect (OSTI)

    Majumder, S.A.; Ondrias, M.R. . Dept. of Chemistry); Prairie, M.R. ); Shelnutt, J.A. . Dept. of Chemistry Sandia National Labs., Albuquerque, NM )

    1991-01-01

    Titanium dioxide (TiO{sub 2}) is a photocatalyst for solar detoxification of water containing organic contaminants such as solvents, PCB's, dioxins, pesticides, and dyes. Unfortunately, the ultraviolet (UV) energy used by TiO{sub 2} ({lambda}<400 nm) only comprises about 4% of the solar spectrum. One way of enhancing the efficiency of solar detoxification technologies is to utilize a larger portion of the solar spectrum to initiate the Tio{sub 2}- catalyzed detoxification chemistry. Metalloporphyrins strongly absorb visible and near infrared radiation. By utilization of a process called photosensitization, adsorption of these dyes onto TiO{sub 2} can enable a much broader portion of the solar spectrum to be used. Photosensitization relies upon the ability of the dye molecule to absorb more of the solar energy than bare TiO{sub 2} and to interact electronically with the TiO{sub 2} surface in such a way as to initiate TiO{sub 2}-based redox photochemistry using the dye-absorbed energy. 16 refs., 7 figs.

  6. WO3/TiO2 nanotube photoanodes for solar water splitting with simultaneous wastewater treatment.

    SciTech Connect (OSTI)

    Reyes, Karla Rosa; Robinson, David B.

    2013-05-01

    Nanostructured WO3/TiO2 nanotubes with properties that enhance solar photoconversion reactions were developed, characterized and tested. The TiO2 nanotubes were prepared by anodization of Ti foil, and WO3 was electrodeposited on top of the nanotubes. SEM images show that these materials have the same ordered structure as TiO2 nanotubes, with an external nanostructured WO3 layer. Diffuse reflectance spectra showed an increase in the visible absorption relative to bare TiO2 nanotubes, and in the UV absorption relative to bare WO3 films. Incident simulated solar photon-to-current efficiency increased from 30% (for bare WO3) to 50% (for WO3/TiO2 composites). With the addition of diverse organic pollutants, the photocurrent densities exhibited more than a 5-fold increase. Chemical oxygen demand measurements showed the simultaneous photodegradation of organic pollutants. The results of this work indicate that the unique structure and composition of these composite materials enhance the charge carrier transport and optical properties compared with the parent materials.

  7. A Comparative Study of the Water Gas Shift Reaction Over Platinum Catalysts Supported on CeO2, TiO2 and Ce-Modified TiO2

    SciTech Connect (OSTI)

    Gonzalez, I.; Navarro, R; Wen, W; Marinkovic, N; Rodriguez, J; Rosa, F; Fierro, J

    2010-01-01

    WGS reaction has been investigated on catalysts based on platinum supported over CeO{sub 2}, TiO{sub 2} and Ce-modified TiO{sub 2}. XPS and XANES analyses performed on calcined catalysts revealed a close contact between Pt precursors and cerium species on CeO{sub 2} and Ce-modified TiO{sub 2} supports. TPR results corroborate the intimate contact between Pt and cerium entities in the Pt/Ce-TiO{sub 2} catalyst that facilitates the reducibility of the support at low temperatures while the Ce-O-Ti surface interactions established in the Ce-modified TiO{sub 2} support decreases the reduction of TiO{sub 2} at high temperature. The changes in the support reducibility leads to significant differences in the WGS activity of the studied catalysts. Pt supported on Ce-modified TiO{sub 2} support exhibits better activity than those corresponding to individual CeO{sub 2} and TiO{sub 2}-supported catalysts. Additionally, the Ce-TiO{sub 2}-supported catalyst displays better stability at reaction temperatures higher than 573 K that observed on pure TiO{sub 2}-supported counterpart. Activity measurements, when coupled with the physicochemical characterization of catalysts suggest that the modifications in the surface reducibility of the support play an essential role in the enhancement of activity and stability observed when Pt is supported on the Ce-modified TiO{sub 2} substrate.

  8. THE SENSITIVITY OF CARBON STEELS' SUSCEPTIBILITY TO LOCALIZED CORROSION TO THE PH OF NITRATE BASED NUCLEAR WASTES

    SciTech Connect (OSTI)

    BOOMER KD

    2010-01-14

    The Hanford tank reservation contains approximately 50 million gallons of liquid legacy radioactive waste from cold war weapons production, which is stored in 177 underground storage tanks. The tanks will be in use until waste processing operations are completed. The wastes tend to be high pH (over 10) and nitrate based. Under these alkaline conditions carbon steels tend to be passive and undergo relatively slow uniform corrosion. However, the presence of nitrate and other aggressive species, can lead to pitting and stress corrosion cracking. This work is a continuation of previous work that investigated the propensity of steels to suffer pitting and stress corrosion cracking in various waste simulants. The focus of this work is an investigation of the sensitivity of the steels' pitting and stress corrosion cracking susceptibility tosimulant pH. Previous work demonstrated that wastes that are high in aggressive nitrate and low in inhibitory nitrite are susceptible to localized corrosion. However, the previous work involved wastes with pH 12 or higher. The current work involves wastes with lower pH of 10 or 11. It is expected that at these lower pHs that a higher nitrite-to-nitrate ratio will be necessary to ensure tank integrity. This experimental work involved both electrochemical testing, and slow strain rate testing at either the free corrosion potential or under anodic polarization. The results of the current work will be discussed, and compared to work previously presented.

  9. Draft Genome Sequence for Microbacterium laevaniformans Strain OR221, a Bacterium Tolerant to Metals, Nitrate, and Low pH

    SciTech Connect (OSTI)

    Brown, Steven D; Palumbo, Anthony Vito; Panikov, Nikolai; Ariyawansa, Thilini; Klingeman, Dawn Marie; Johnson, Courtney M; Land, Miriam L; Utturkar, Sagar M; Epstein, Slava

    2012-01-01

    Microbacterium laevaniformans strain OR221 was isolated from subsurface sediments obtained from the Field Research Center (FRC) in Oak Ridge, TN. It was characterized as a bacterium tolerant to heavy metals such as uranium, nickel, cobalt, cadmium, as well as nitrate and low pH. We present its draft genome sequence.

  10. Separation of switchgrass bio-oil by water/organic solvent addition and pH adjustment

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Park, Lydia Kyoung-Eun; Ren, Shoujie; Yiacoumi, Sotira; Ye, X. Philip; Borole, Abhijeet P.; Tsouris, Costas

    2016-01-01

    Applications of bio-oil are limited by its challenging properties including high moisture content, low pH, high viscosity, high oxygen content, and low heating value. Separation of switchgrass bio-oil components by adding water, organic solvents (hexadecane and octane), and sodium hydroxide may help to overcome these issues. Acetic acid and phenolic compounds were extracted in aqueous and organic phases, respectively. Polar chemicals, such as acetic acid, did not partition in the organic solvent phase. Acetic acid in the aqueous phase after extraction is beneficial for a microbial-electrolysis-cell application to produce hydrogen as an energy source for further hydrodeoxygenation of bio-oil. Organicmore » solvents extracted more chemicals from bio-oil in combined than in sequential extraction; however, organic solvents partitioned into the aqueous phase in combined extraction. When sodium hydroxide was added to adjust the pH of aqueous bio-oil, organic-phase precipitation occurred. As the pH was increased, a biphasic aqueous/organic dispersion was formed, and phase separation was optimized at approximately pH 6. The neutralized organic bio-oil had approximately 37% less oxygen and 100% increased heating value than the initial centrifuged bio-oil. In conclusion, the less oxygen content and increased heating value indicated a significant improvement of the bio-oil quality through neutralization.« less

  11. Synthesis and characterization of F-N-W-codoped TiO{sub 2} photocatalyst with enhanced visible light response

    SciTech Connect (OSTI)

    Shi, Xiaoliang; School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070 ; Qin, Haibo; Yang, Xingyong; Zhang, Qiaoxin; School of Materials Science and Engineering, Wuhan University of Technology, 122 Luoshi Road, Wuhan 430070

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ? Anatase F-N-W-codoped TiO{sub 2} was prepared by a solgel-hydrothermal method. ? Under visible illumination, carbon removal rate of RB reached 94% using F-7NW-TiO{sub 2}. ? F, N and W dopants narrowed band gap and lowed charge pairs recombination rate. ? There were W{sub x}Ti{sub 1?x}O{sub 2}, O-Ti-N and valence variation of W ions existing. -- Abstract: Anatase F-N-W-codoped TiO{sub 2} photocatalyst was successfully prepared by a method combining solgel with hydrothermal treatment. Effects of F, N and W ion dosage concentration on the crystallinity, morphology, grain size and chemical status of the photocatalyst were investigated. The results showed that the F-7NW-TiO{sub 2} photocatalyst composed of uniform ellipsoidal particles around 20 nm in length and 10 nm in width, and the photocatalyst displayed enhanced visible-light absorption and photocatalytic activities. Using the photocatalyst and under visible irradiation for 1.5 h, the decoloration percent of RB and carbon removal rate were about 98% and 94% respectively, which were much higher than that of commercial P25, TiO{sub 2}, N-W-TiO{sub 2} and F-TiO{sub 2}. The high visible-light photocatalytic activity of F-7NW-TiO{sub 2} might result from narrowing the band gap and lowing charge pairs recombination rate for the W{sub x}Ti{sub 1?x}O{sub 2}, O-Ti-N and valence variation of W ions existing.

  12. Molecular basis of the structural stability of a Top7-based scaffold at extreme pH and temperature conditions

    SciTech Connect (OSTI)

    Soares, Thereza A.; Boschek, Curt B.; Apiyo, David O.; Baird, Cheryl L.; Straatsma, TP

    2010-07-01

    The development of stable scaffolds that can tolerate environmental extremes has an immense potential for applications in industry and defense. Recently, we have engineered an eight-residue loop into the de novo designed Top7 protein, which specifically binds the glycoprotein CD4. The robust properties of the Top7, coupled with the ease in production, make it a robust scaffold to design novel functionalities for use under extreme environmental conditions. In the present work, a series of explicit-solvent molecular dynamics simulations are reported which investigates the effect of mutations and extreme conditions of temperature and pH on the structure, stability, and dynamics of the native and engineered Top7. These simulations indicate that i. The structural dynamics of the engineered and native Top7 in solution are equivalent under corresponding conditions of pH and temperature. Ensemble-averaged structures of the native and engineered Top7 maintain the overall tertiary structure pattern, albeit with loss of helical content when at low pH and high-temperature conditions. Mutations of residues E43A, D46A, E67A, E69A, EA81A along the ?-helices of the engineered Top7 did not lead to significant changes in the native fold under pH 2 and 400 K, suggesting that the helices can accommodate varying sequences. iii. The anti-parallel ?-sheet is the structural core responsible for the stability of the native and engineered Top7 and is well maintained under extreme pH and temperature conditions. These findings indicate that the insertion of an eight-residue loop into the structure of Top7 does not adversely affect the global fold or the structural stability of the Top7 scaffold.

  13. Fatigue crack growth behavior of Ti-1100 at elevated temperature

    SciTech Connect (OSTI)

    Maxwell, D.C.; Nicholas, T.

    1995-12-31

    Effects of temperature, frequency, and cycles with superimposed hold times are evaluated in Ti-1100 in order to study the complex creep-fatigue-environment interactions in this material. Crack growth rate tests conducted at cyclic loading frequency of 1.0 Hz show that raising the temperature from 593 to 650 C has only a slightly detrimental effect on crack growth rate, although these temperatures produce growth rates significantly higher than at room temperature. From constant {Delta}K tests, the effects of temperature at constant frequency show a minimum crack growth rate at 250 C. From the minimum crack growth rate at 250 C, the crack growth rate increases linearly with temperature. Increases in frequency at constant temperatures of 593 and 650 C produce a continuous decrease in growth rate in going from 0.001 to 1.0 Hz, although the behavior is primarily cycle dependent in this region. Tests at 1.0 Hz with superimposed hold times from 1 to 1,000 s are used to evaluate creep-fatigue-environment interactions. Hold times at maximum load are found to initially decrease and then increase the cyclic crack growth rate with increasing duration. This is attributed to crack-tip blunting during short hold times and environmental degradation at long hold times. Hold times at minimum load show no change in growth rates, indicating that there is no net environmental degradation to the bulk material beyond that experienced during the baseline 1 Hz cycling.

  14. Metallic glass alloys of Zr, Ti, Cu and Ni

    DOE Patents [OSTI]

    Lin, Xianghong (Pasadena, CA); Peker, Atakan (Pasadena, CA); Johnson, William L. (Pasadena, CA)

    1997-01-01

    At least quaternary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10.sup.3 K/s. Such alloys comprise titanium from 19 to 41 atomic percent, an early transition metal (ETM) from 4 to 21 atomic percent and copper plus a late transition metal (LTM) from 49 to 64 atomic percent. The ETM comprises zirconium and/or hafnium. The LTM comprises cobalt and/or nickel. The composition is further constrained such that the product of the copper plus LTM times the atomic proportion of LTM relative to the copper is from 2 to 14. The atomic percentage of ETM is less than 10 when the atomic percentage of titanium is as high as 41, and may be as large as 21 when the atomic percentage of titanium is as low as 24. Furthermore, when the total of copper and LTM are low, the amount of LTM present must be further limited. Another group of glass forming alloys has the formula (ETM.sub.1-x Ti.sub.x).sub.a Cu.sub.b (Ni.sub.1-y Co.sub.y).sub.c wherein x is from 0.1 to 0.3, y.cndot.c is from 0 to 18, a is from 47 to 67, b is from 8 to 42, and c is from 4 to 37. This definition of the alloys has additional constraints on the range of copper content, b.

  15. Advancements in Ti Alloy Powder Production by Close-Coupled Gas Atomization

    SciTech Connect (OSTI)

    Heidloff, Andy; Rieken, Joel; Anderson, Iver; Byrd, David

    2011-04-01

    As the technology for titanium metal injection molding (Ti-MIM) becomes more readily available, efficient Ti alloy fine powder production methods are required. An update on a novel close-coupled gas atomization system has been given. Unique features of the melting apparatus are shown to have measurable effects on the efficiency and ability to fully melt within the induction skull melting system (ISM). The means to initiate the melt flow were also found to be dependent on melt apparatus. Starting oxygen contents of atomization feedstock are suggested based on oxygen pick up during the atomization and MIM processes and compared to a new ASTM specification. Forming of titanium by metal injection molding (Ti-MIM) has been extensively studied with regards to binders, particle shape, and size distribution and suitable de-binding methods have been discovered. As a result, the visibility of Ti-MIM has steadily increased as reviews of technology, acceptability, and availability have been released. In addition, new ASTM specification ASTM F2885-11 for Ti-MIM for biomedical implants was released in early 2011. As the general acceptance of Ti-MIM as a viable fabrication route increases, demand for economical production of high quality Ti alloy powder for the preparation of Ti-MIM feedstock correspondingly increases. The production of spherical powders from the liquid state has required extensive pre-processing into different shapes thereby increasing costs. This has prompted examination of Ti-MIM with non-spherical particle shape. These particles are produced by the hydride/de-hydride process and are equi-axed but fragmented and angular which is less than ideal. Current prices for MIM quality titanium powder range from $40-$220/kg. While it is ideal for the MIM process to utilize spherical powders within the size range of 0.5-20 {mu}m, titanium's high affinity for oxygen to date has prohibited the use of this powder size range. In order to meet oxygen requirements the top size cut has traditionally been 45 {mu}m, and in some instances a bottom cut at +5 {mu}m is made to remove ultra-fine particles and reduce oxygen content. Predictably, use of irregular shaped or larger particle feedstock powder can reduce part quality as sintering shrinkage and part detail suffer. Thus, widespread production and technological use of Ti-MIM is limited due in large part to Ti alloy feedstock cost and availability, not MIM processing capability. Lower cost feedstock of fine, spherical Ti alloy powder with sufficient purity must be available in order to fully utilize the advantages of the Ti-MIM processing route allowing expansion of the market to small complex Ti parts in many high volume applications.

  16. Synthesis and characterization of CdS doped TiO{sub 2} nanocrystalline powder: A spectroscopic study

    SciTech Connect (OSTI)

    Thakur, Priya; Chadha, Ridhima; Biswas, Nandita; Sarkar, Sisir K.; Mukherjee, Tulsi; Joshi, Satyawati S.; Kapoor, Sudhir

    2012-07-15

    Graphical abstract: Raman spectra of TiO{sub 2} sample doped with 50% CdS and annealed at 600 C. Highlights: ? Transformation from anatase to rutile is prohibited in doped TiO{sub 2}. ? FTIR study indicates that TiO{sub 2} lattice has been modified in the presence of CdS. ? Raman spectroscopy is found to be more sensitive as compared to XRD. -- Abstract: This report aimed to study the effect of CdS doping in TiO{sub 2} on the phase transformation of TiO{sub 2} from anatase to rutile using X-ray diffraction (XRD) and Raman spectroscopy. CdS-doped TiO{sub 2} nanocomposites have been prepared and characterized using Fourier transform infrared spectroscopy (FTIR) and transmission electron microscopy (TEM). We have observed that contrary to bare TiO{sub 2}, phase transformation of TiO{sub 2} from anatase to rutile is hindered when doped with CdS at high temperature. Raman spectroscopy is found to be more sensitive for detection of the surface of TiO{sub 2} as compared to XRD.

  17. Reactivity Screening of Anatase TiO2 Nanotube Arrays and Anatase Thin Films: A Surface Chemistry Point of View

    SciTech Connect (OSTI)

    Funk, S.; Hokkanen, B.; Nurkic, T.; Goering, J.; Kadossov, E.; Burghaus, Uwe; Ghicov, A.; Schmuki, P.; Yu, Zhongqing; Thevuthasan, Suntharampillai; Saraf, Laxmikant V.

    2008-09-19

    As a reactivity screening we collected thermal desorption spectroscopy (TDS) data of iso-butane, O2, CO2, and CO adsorbed on ordered TiO2 nanotube (TiNTs) arrays. As a reference system iso-butane adsorption on an anatase TiO2 thin film has been considered as well. The as-grown TiNTs are vertically aligned and amorphous. Polycrystalline (poly.) anatase or poly. anatase/rutile mixed nanotubes are formed by annealing confirmed by x-ray diffraction (XRD) and scanning electron microscopy (SEM). The anatase thin film was grown on SrTiO3(001) and characterized by XRD and atomic force microscopy (AFM). Surprisingly, oxygen distinctly interacts with the TiNTs whereas this process is not observed on fully oxidized single crystal rutile TiO2(110). Desorption temperatures of 110-150 K and 100-120 K were observed for CO2 and CO, respectively, on the TiNTs. Variations in the binding energies of the alkanes on TiNTs and anatase thin films also were present, i.e., a structure-activity relationship (SAR) is evident.

  18. Structure of epitaxial (Fe,N) codoped rutile TiO2 thin films by x-ray absorption

    SciTech Connect (OSTI)

    Kaspar, Tiffany C.; Ney, A.; Mangham, Andrew N.; Heald, Steve M.; Joly, Yves; Ney, V.; Wilhelm, F.; Rogalev, A.; Yakou, Flora; Chambers, Scott A.

    2012-07-23

    Homoepitaxial thin films of Fe:TiO2 and (Fe,N):TiO2 were deposited on rutile(110) by molecular beam epitaxy. X-ray absorption near edge spectroscopy (XANES) spectra were collected at the Ti L-edge, Fe L-edge, O K-edge, N K-edge, and Ti K-edge. No evidence of structural disorder associated with a high concentration of oxygen vacancies is observed. Substitution of Fe for Ti could not be confirmed, although secondary phase Fe2O3 and metallic Fe can be ruled out. The similarity of the N K-edge spectra to O, and the presence of a strong x-ray linear dichroism (XLD) signal for the N K-edge, indicates that N is substitutional for O in the rutile lattice, and is not present as a secondary phase such as TiN. Simulations of the XANES spectra qualitatively confirm substitution, although N appears to be present in more than one local environment. Neither Fe:TiO2 nor (Fe,N):TiO2 exhibit intrinsic room temperature ferromagnetism, despite the presence of mixed valence Fe(II)/Fe(III) in the reduced (Fe,N):TiO2 film.

  19. Direct imaging of LaAlO{sub 3}/SrTiO{sub 3} nanostructures using

    Office of Scientific and Technical Information (OSTI)

    piezoresponse force microscopy (Journal Article) | SciTech Connect Direct imaging of LaAlO{sub 3}/SrTiO{sub 3} nanostructures using piezoresponse force microscopy Citation Details In-Document Search Title: Direct imaging of LaAlO{sub 3}/SrTiO{sub 3} nanostructures using piezoresponse force microscopy The interface between LaAlO{sub 3} and TiO{sub 2}-terminated SrTiO{sub 3} can be switched between metastable conductive and insulating states using a conductive atomic force microscope probe.

  20. The electronic and optical properties of Eu/Si-codoped anatase TiO{sub 2} photocatalyst

    SciTech Connect (OSTI)

    Lin Yanming; Jiang Zhenyi; Zhang Xiaodong; Hu Xiaoyun; Fan Jun

    2012-03-05

    The electronic and optical properties of Eu/Si-codoped anatase TiO{sub 2} are investigated using the density functional theory. The calculated results show that the synergistic effects of Eu/Si codoping can effectively extend the optical absorption edge, which can lead to higher visible-light photocatalytic activities than pure anatase TiO{sub 2}. To verify the reliability of our calculated results, nanocrystalline Eu/Si-codoped TiO{sub 2} is prepared by a sol-gel-solvothermal method, and the experimental results also indicate that the codoping sample exhibits better absorption performance and higher photocatalytic activities than pure TiO{sub 2}.

  1. The visible light degradation activity and the photocatalytic mechanism of tetra(4-carboxyphenyl) porphyrin sensitized TiO{sub 2}

    SciTech Connect (OSTI)

    Wang, Huigang; Zhou, Dongmei; Wu, Zhangzhu; Wan, Junmin; Zheng, Xuming; Yu, Lihong; Phillips, David Lee

    2014-09-15

    Highlights: Tetra(4-carboxyphenyl) porphyrin were chemically sensitized on TiO{sub 2}. S2S0 fluorescence intensity is enhanced and lifetime prolonged noticeably by TiO{sub 2}. The TCPP-TiO{sub 2} exhibits better photoactivity under visible light than that of TiO{sub 2}. The electronic relaxation dynamics is presented, catalytic mechanism is discussed. Adsorption and photo degradation of MB were systematically investigated. - Abstract: Tetra(4-carboxyphenyl) porphyrin(TCPP) were chemically sensitized on TiO{sub 2} to act as visible light antenna and to modify the photoresponse properties of TiO{sub 2} particles, their properties of photo-generated holes and electrons were studied by transient absorption spectroscopes. The time-correlated single-photon counting (TCSPC) technique revealed that the S2S0 fluorescence intensity of TCPP is enhanced noticeably by TiO{sub 2}, and the lifetime prolonged. Adsorption and photo degradation of methylene blue (MB) over TCPP-TiO{sub 2} were systematically investigated. Moreover the overall picture of electronic relaxation dynamics for TCPP-TiO{sub 2} is presented, and the detailed short-time dynamics for visible-light induced catalytic mechanism was discussed. The development of the porphyrin-based photocatalyst provides an alternative approach in harnessing solar visible light and show promising prospect for the treatment of dye pollutants from wastewaters in future industrial application.

  2. A study of photocatalytic grapheneTiO{sub 2} synthesis via peroxo titanic acid refluxed sol

    SciTech Connect (OSTI)

    Low, Wasu; Boonamnuayvitaya, Virote

    2013-08-01

    Graphical abstract: - Highlights: TiO{sub 2} synthesized via PTA as a precursor demonstrates exclusively anatase phase. The TEM image of GRTiO{sub 2} (PTA) demonstrates that TiO{sub 2} nanoparticles are successfully loaded onto graphene sheet. The specific surface area seems to increase with increasing weight ratio of graphene oxide. It was observed that GRTiO{sub 2} showed higher adsorption compared to bare TiO{sub 2} (PTA). The GRTiO{sub 2} (PTA, 1:50) catalyst showed higher photocatalytic activity than any other catalyst. - Abstract: In the present work, grapheneTiO{sub 2} (GRTiO{sub 2}) photocatalyst with various weight ratios of graphene was synthesized using peroxo titanic acid solution (PTA) as a precursor for TiO{sub 2}. Graphene oxide prepared by Hummer's method was converted to graphene under ultraviolet (UV) irradiation in ethanolwater solvent for 48 h. The as-prepared GRTiO{sub 2} composites were characterized using X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, UVvis spectrophotometry, and transmission electron microscopy (TEM). The automated potentiostat was applied to measure the photocurrent generations of prepared catalysts. The photocatalytic activities of GRTiO{sub 2} (PTA) catalysts were determined by measuring the percentage methylene blue (MB) degradation. The results showed that TiO{sub 2} nanoparticles were successfully loaded onto graphene sheet and the surface area of catalysts increased with increasing weight ratio of graphene. In addition, GRTiO{sub 2} (PTA, 1:50) exhibited the highest photocatalytic activity among the catalysts under UV and visible light irradiation. The adsorption edge of GRTiO{sub 2} was shifted to a longer wavelength of 400 nm in comparison with that of pure TiO{sub 2} (PTA). The increase in the photocatalytic performance of GRTiO{sub 2} (PTA) catalyst may be attributed to the increase in surface area, the extension of light absorption in the visible light region, and prevention of charge recombination.

  3. Direct imaging of LaAlO{sub 3}/SrTiO{sub 3} nanostructures using...

    Office of Scientific and Technical Information (OSTI)

    Direct imaging of LaAlOsub 3SrTiOsub 3 nanostructures using piezoresponse force ... (United States) Department of Materials Science and Engineering, University of ...

  4. Thin films of the spin ice compound Ho{sub 2}Ti{sub 2}O{sub 7} (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | SciTech Connect Thin films of the spin ice compound Ho{sub 2}Ti{sub 2}O{sub 7} Citation Details In-Document Search Title: Thin films of the spin ice compound Ho{sub 2}Ti{sub 2}O{sub 7} The pyrochlore compounds Ho{sub 2}Ti{sub 2}O{sub 7} and Dy{sub 2}Ti{sub 2}O{sub 7} show an exotic form of magnetism called the spin ice state, resulting from the interplay between geometrical frustration and ferromagnetic coupling. A fascinating feature of this state is the appearance of magnetic

  5. A New Method of Low Cost Production of Ti Alloys to Reduce Energy Consumption of Mechanical Systems

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    Univ. of Utah Ravi Chandran, Co-PI, Univ. of Utah U.S. DOE Advanced Manufacturing Office Peer Review Meeting Washington, D.C. May 28-29, 2015 This presentation does not contain any proprietary, confidential, or otherwise restricted information. Project Objective  Develop a novel low cost method for manufacturing Ti  Demonstrate the mechanical properties of Ti using the new method to be equivalent to that of wrought Ti at a fraction of its cost.  Initiate efforts to promote the use of Ti

  6. Direct observation of oxygen-vacancy-enhanced polarization in a SrTiO3-buffered ferroelectric BaTiO3 film on GaAs

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Qiao, Q.; Zhang, Y.; Contreras-Guerrero, Rocio; Droopad, Ravi; Pantelides, S. T.; Pennycook, Stephen J.; Ogut, Serdar; Klie, Robert F.

    2015-11-16

    The integration of functional oxide thin-films on compound semiconductors can lead to a class of reconfigurable spin-based optoelectronic devices if defect-free, fully reversible active layers are stabilized. However, previous first-principles calculations predicted that SrTiO3 thin filmsgrown on Si exhibit pinned ferroelectric behavior that is not switchable, due to the presence of interfacial vacancies. Meanwhile, piezoresponse force microscopy measurements have demonstrated ferroelectricity in BaTiO3 grown on semiconductor substrates. The presence of interfacial oxygen vacancies in such complex-oxide/semiconductor systems remains unexplored, and their effect on ferroelectricity is controversial. We also use a combination of aberration-corrected scanning transmission electron microscopy and first-principles densitymore » functional theory modeling to examine the role of interfacial oxygen vacancies on the ferroelectricpolarization of a BaTiO3 thin filmgrown on GaAs. Moreover, we demonstrate that interfacial oxygen vacancies enhance the polar discontinuity (and thus the single domain, out-of-plane polarization pinning in BaTiO3), and propose that the presence of surface charge screening allows the formation of switchable domains.« less

  7. Adsorption, Desorption, and Dissociation of Benzene on TiO2(110) and Pd/TiO2(110)

    SciTech Connect (OSTI)

    Zhou, Jing; Dag, Sefa; Senanayake, Sanjaya D; Hathorn, Bryan C; Kalinin, Sergei V; Meunier, Vincent; Mullins, David R; Overbury, Steven {Steve} H; Baddorf, Arthur P

    2006-01-01

    Adsorption and reaction of benzene molecules on clean TiO{sub 2}(110) and on TiO{sub 2}(110) with deposited Pd nanoparticles are investigated using a combination of scanning tunneling microscopy (STM), temperature-programmed desorption, and first-principles calculations. Above {approx}50 K, the one-dimensional motion of benzene between bridging oxygen rows is shown to be too fast for STM imaging. At 40 K benzene molecules form chains on top of titanium rows, with calculations indicating every other benzene is rotated 30{sup o}. Both experimental and theoretical studies find no dissociative reactivity of benzene on the clean TiO{sub 2}(110) surface, due to little hybridization between TiO{sub 2} and benzene electronic states. After deposition of Pd nanoparticles, molecular benzene is observed with STM both on the substrate and adjacent to metallic particles. Upon heating to 800 K, benzene fully breaks down into its atomic constituents in a multistep decomposition process.

  8. Thermal conductivity of nitride films of Ti, Cr, and W deposited by reactive magnetron sputtering

    SciTech Connect (OSTI)

    Jagannadham, Kasichainula

    2015-05-15

    Nitride films of Ti, Cr, and W were deposited using reactive magnetron sputtering from metal targets in argon and nitrogen plasma. TiN films with (200) orientation were achieved on silicon (100) at the substrate temperature of 500 and 600?C. The films were polycrystalline at lower temperature. An amorphous interface layer was observed between the TiN film and Si wafer deposited at 600?C. TiN film deposited at 600?C showed the nitrogen to Ti ratio to be near unity, but films deposited at lower temperature were nitrogen deficient. CrN film with (200) orientation and good stoichiometry was achieved at 600?C on Si(111) wafer but the film deposited at 500?C showed cubic CrN and hexagonal Cr{sub 2}N phases with smaller grain size and amorphous back ground in the x-ray diffraction pattern. An amorphous interface layer was not observed in the cubic CrN film on Si(111) deposited at 600?C. Nitride film of tungsten deposited at 600?C on Si(100) wafer was nitrogen deficient, contained both cubic W{sub 2}N and hexagonal WN phases with smaller grain size. Nitride films of tungsten deposited at 500?C were nonstoichiometric and contained cubic W{sub 2}N and unreacted W phases. There was no amorphous phase formed along the interface for the tungsten nitride film deposited at 600?C on the Si wafer. Thermal conductivity and interface thermal conductance of all the nitride films of Ti, Cr, and W were determined by transient thermoreflectance technique. The thermal conductivity of the films as function of deposition temperature, microstructure, nitrogen stoichiometry and amorphous interaction layer at the interface was determined. Tungsten nitride film containing both cubic and hexagonal phases was found to exhibit much higher thermal conductivity and interface thermal conductance. The amorphous interface layer was found to reduce effective thermal conductivity of TiN and CrN films.

  9. REE Sorption Study on sieved -50 +100 mesh fraction of Media #1 in Brine #1 with Different Starting pH's at 70C

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Gary Garland

    2015-09-29

    This is a continuation of the REE sorption study for shaker bath tests on 2g media #1 in 150mL brine #1 with different starting pH's at 70C. In a previous submission we reported data for shaker bath tests for brine #1 with starting pH's of 3.5, 4.5 and 5.5. In this submission we these pH's compared to starting brine #1 pH's of 6, and 7.

  10. Efficient H{sub 2} production over Au/graphene/TiO{sub 2} induced by surface plasmon resonance of Au and band-gap excitation of TiO{sub 2}

    SciTech Connect (OSTI)

    Liu, Yang; Yu, Hongtao; Wang, Hua; Chen, Shuo; Quan, Xie

    2014-11-15

    Highlights: Both surface plasmon resonance and band-gap excitation were used for H{sub 2} production. Au/Gr/TiO{sub 2} composite photocatalyst was synthesized. Au/Gr/TiO{sub 2} exhibited enhancement of light absorption and charge separation. H{sub 2} production rate of Au/Gr/TiO{sub 2} was about 2 times as high as that of Au/TiO{sub 2}. - Abstract: H{sub 2} production over Au/Gr/TiO{sub 2} composite photocatalyst induced by surface plasmon resonance of Au and band-gap excitation of TiO{sub 2} using graphene (Gr) as an electron acceptor has been investigated. Electron paramagnetic resonance study indicated that, in this composite, Gr collected electrons not only from Au with surface plasmon resonance but also from TiO{sub 2} with band-gap excitation. Surface photovoltage and UVvis absorption measurements revealed that compared with Au/TiO{sub 2}, Au/Gr/TiO{sub 2} displayed more effective photogenerated charge separation and higher optical absorption. Benefiting from these advantages, the H{sub 2} production rate of Au/Gr/TiO{sub 2} composite with Gr content of 1.0 wt% and Au content of 2.0 wt% was about 2 times as high as that of Au/TiO{sub 2}. This work represents an important step toward the efficient application of both surface plasmon resonance and band-gap excitation on the way to converting solar light into chemical energy.

  11. Microstructure and tribological performance of nanocomposite Ti-Si-C-N coatings deposited using hexamethyldisilazane precursor

    SciTech Connect (OSTI)

    Wei Ronghua; Rincon, Christopher; Langa, Edward; Yang Qi

    2010-09-15

    Thick nanocomposite Ti-Si-C-N coatings (20-30 {mu}m) were deposited on Ti-6Al-4V substrate by magnetron sputtering of Ti in a gas mixture of Ar, N{sub 2}, and hexamethyldisilazane (HMDSN) under various deposition conditions. Microstructure and composition of the coatings were studied using scanning electron microscopy, x-ray diffraction, and energy dispersive x-ray spectroscopy, while the mechanical and tribological properties of these coatings were studied using Rc indentation, and micro- and nanoindentations, solid particle erosion testing, and ball-on-disk wear testing. It has been observed that the Si concentration of these coatings is varied from 0% (TiN) to 15% (Ti-Si-C-N), while the structure of these coatings is similar to the nanocomposite Ti-Si-N coatings and consists of nanocrystalline B1 structured Ti(C,N) in an amorphous matrix of SiC{sub x}N{sub y} with the grain size of 5->100 nm, depending on the coating preparation process. These coatings exhibit excellent adhesion when subjected to Rc indentation tests. The microhardness of these coatings varies from 1200 to 3400 HV25, while the nanohardness varies from 10 to 26 GPa. Both the microhardness and nanohardness are slightly lower than those of similar coatings prepared using trimethylsilane. However, the erosion test using a microsand erosion tester at both 30 deg. and 90 deg. incident angles shows that these coatings have very high erosion resistance and up to a few hundred times of improvement has been observed. These coatings also exhibit very high resistance to sliding wear with a low coefficient of friction of about 0.2 in dry sliding. There are a few advantages of using the HMDSN precursor to prepare the Ti-Si-C-N coatings over conventional magnetron sputtered deposition of Ti-Si-N coatings including composition uniformity, precursor handling safety, and high deposition rate. The coatings can be applied to protect gas turbine compressor blades from solid particle erosion and steam turbine blades from liquid droplet erosion, as well as other mechanical components that experience severe abrasion. These coatings may also be used in areas where both high wear resistance and low friction are required.

  12. Deformation and fracture behavior of composite structured Ti-Nb-Al-Co(-Ni) alloys

    SciTech Connect (OSTI)

    Okulov, I. V. Marr, T.; Schultz, L.; Eckert, J.; Khn, U.; Freudenberger, J.; Oertel, C.-G.; Skrotzki, W.

    2014-02-17

    Tensile ductility of the Ti-based composites, which consist of a ?-Ti phase surrounded by ultrafine structured intermetallics, is tunable through the control of intermetallics. The two Ti-based alloys studied exhibit similar compressive yield strength (about 1000?MPa) and strain (about 35%40%) but show a distinct difference in their tensile plasticity. The alloy Ti{sub 71.8}Nb{sub 14.1}Ni{sub 7.4}Al{sub 6.7} fractures at the yield stress while the alloy Ti{sub 71.8}Nb{sub 14.1}Co{sub 7.4}Al{sub 6.7} exhibits about 4.5% of tensile plastic deformation. To clarify the effect of microstructure on the deformation behavior of these alloys, tensile tests were carried out in the scanning electron microscope. It is shown that the distribution as well as the type of intermetallics affects the tensile ductility of the alloys.

  13. Investigation of the phase equilibrium of alloys of the ternary system Ti-Al-Nb

    SciTech Connect (OSTI)

    Nartova, T.T.; Sopochkin, G.G.

    1987-09-09

    This investigation of the constitution diagram of the ternary system titanium-aluminum-niobium is limited to the specific system Ti-Ti3A1-Nb in order to establish the regions of the alpha and beta solid solutions of titanium, the solid solutions based on aluminide Ti3A1, and the phases conjugated with them. The constitution diagram of the systems Ti-A1 and Ti-Nb obtained from the data were used as the basis for constructing the constitution diagram of the ternary system. The methods of microstructural, thermal and X ray phase analysis were used in the study. The X ray pictures were taken in copper emission from powders that had been preliminarily annealed in a vacuum at 600 for 30 min. Iodic titanium, aluminum brand AV-000 and fillet niobium were used as the source materials. The alloys were remelted five times in an electric-arc furnace with a nonconsumable tungsten electrode in an argon atmosphere, and then by crucibleless melting in the suspended state. The constancy of the chemical composition of the alloys was monitored by their weight after smelting in an electric arc furnace.

  14. First-principles study on negative thermal expansion of PbTiO{sub 3}

    SciTech Connect (OSTI)

    Wang, Fangfang; Chen, Jun; Xing, Xianran; Xie, Ying; Fu, Honggang

    2013-11-25

    It is well known that perovskite-type PbTiO{sub 3} behaves negative thermal expansion in a wide temperature range from room temperature to Curie temperature (763?K). The present study reports the first-principles study of the anisotropic thermal expansion of PbTiO{sub 3}, in the framework of the density-functional theory and the density-functional perturbation theory. The curve of temperature dependence of the unit cell volume is presented from 20 to 520?K through the calculation of the minimum of total free energy at each temperature point. The negative thermal expansion of PbTiO{sub 3} is calculated without empirical parameters. Furthermore, the distinctive thermodynamic act of PbTiO{sub 3} from expanding to contracting at tetragonal phase is reproduced. The ab-initio calculations reveal that this unique appearance depends on the phonon vibration. The dynamical contributions of various atoms are also calculated to account for the disparate role of Pb-O and Ti-O bond.

  15. Influence of rare earth doping on thermoelectric properties of SrTiO{sub 3} ceramics

    SciTech Connect (OSTI)

    Liu, J. Wang, C. L.; Li, Y.; Su, W. B.; Zhu, Y. H.; Li, J. C.; Mei, L. M.

    2013-12-14

    Thermoelectric properties of SrTiO{sub 3} ceramics, doped with different rare earth elements, were investigated in this work. It's found that the ionic radius of doping elements plays an important role on thermoelectric properties: SrTiO{sub 3} ceramics doped with large rare earth ions (such as La, Nd, and Sm) exhibit large power factors, and those doped with small ions (such as Gd, Dy, Er, and Y) exhibit low thermal conductivities. Therefore, a simple approach for enhancing the thermoelectric performance of SrTiO{sub 3} ceramics is proposed: mainly doped with large ions to obtain a large power factor and, simultaneously, slightly co-doped with small ions to obtain a low thermal conductivity. Based on this rule, Sr{sub 0.8}La{sub 0.18}Yb{sub 0.02}TiO{sub 3} ceramics were prepared, whose ZT value at 1?023?K reaches 0.31, increasing by a factor of 19% compared with the single-doped counterpart Sr{sub 0.8}La{sub 0.2}TiO{sub 3} (ZT?=?0.26)

  16. Significant increase of Curie temperature in nano-scale BaTiO{sub 3}

    SciTech Connect (OSTI)

    Li, Yueliang; Liao, Zhenyu; Fang, Fang; Zhu, Jing; Wang, Xiaohui; Li, Longtu

    2014-11-03

    The low Curie temperature (T{sub c}?=?130?C) of bulk BaTiO{sub 3} greatly limits its applications. In this work, the phase structures of BaTiO{sub 3} nanoparticles with sizes ranging from 2.5?nm to 10?nm were studied at various temperatures by using aberration-corrected transmission electron microscopy (TEM) equipped with an in-situ heating holder. The results implied that each BaTiO{sub 3} nanoparticle was composed of different phases, and the ferroelectric ones were observed in the shells due to the complicated surface structure. The ferroelectric phases in BaTiO{sub 3} nanoparticles remained at 600?C, suggesting a significant increase of T{sub c}. Based on the in-situ TEM results and the data reported by others, temperature-size phase diagrams for BaTiO{sub 3} particles and ceramics were proposed, showing that the phase transition became diffused and the T{sub c} obviously increased with decreasing size. The present work sheds light on the design and fabrication of advanced devices for high temperature applications.

  17. Coreshell TiO? microsphere with enhanced photocatalytic activity and improved lithium storage

    SciTech Connect (OSTI)

    Guo, Hong; Tian, Dongxue; Liu, Lixiang; Wang, Yapeng; Guo, Yuan; Yang, Xiangjun

    2013-05-01

    Inorganic hollow coreshell spheres have attracted considerable interest due to their singular properties and wide range of potential applications. Herein a novel facile generic strategy of combining template assisted and solvothermal alcoholysis is employed to prepare corevoidshell anatase TiO? nanoparticle aggregates with an excellent photocatalytic activity, and enhanced lithium storage in large quantities. Amorphous carbon can be loaded on the TiO? nanoparticles uniformly under a suitably formulated ethanol/water system in the solvothermal alcoholysis process, and the subsequent calcination results of the formation of coreshellshell anatase TiO? nanoparticle aggregates. The intrinsic corevoidshell nature as well as high porosity of the unique nanostructures contributes greatly to the superior photocatalytic activity and improved performance as anode materials for lithium ion batteries. - Graphical abstract: A novel strategy of combining template assisted and solvothermal alcoholysis is employed to prepare unique corevoidshell anatase TiO? nanoparticle aggregates with the superior photocatalytic activity and improved lithium storage. Highlights: TiO? mesospheres are synthesized by solvothermal alcoholysis. It is corevoidshell structure and the thickness of shell is estimated to 80 nm. It exhibits a remarkable photocatalytic activity and improved lithium storage.

  18. Femtosecond laser-induced periodic surface structure on the Ti-based nanolayered thin films

    SciTech Connect (OSTI)

    Petrovi?, Suzana M.; Gakovi?, B.; Peruko, D.; Stratakis, E.; Department of Materials Science and Technology, University of Crete, 710 03 Heraklion, Crete ; Bogdanovi?-Radovi?, I.; ?ekada, M.; Fotakis, C.; Department of Physics, University of Crete, 714 09 Heraklion, Crete ; Jelenkovi?, B.

    2013-12-21

    Laser-induced periodic surface structures (LIPSSs) and chemical composition changes of Ti-based nanolayered thin films (Al/Ti, Ni/Ti) after femtosecond (fs) laser pulses action were studied. Irradiation is performed using linearly polarized Ti:Sapphire fs laser pulses of 40 fs pulse duration and 800 nm wavelength. The low spatial frequency LIPSS (LSFL), oriented perpendicular to the laser polarization with periods slightly lower than the irradiation wavelength, was typically formed at elevated laser fluences. On the contrary, high spatial frequency LIPSS (HSFL) with uniform period of 155 nm, parallel to the laser light polarization, appeared at low laser fluences, as well as in the wings of the Gaussian laser beam distribution for higher used fluence. LSFL formation was associated with the material ablation process and accompanied by the intense formation of nanoparticles, especially in the Ni/Ti system. The composition changes at the surface of both multilayer systems in the LSFL area indicated the intermixing between layers and the substrate. Concentration and distribution of all constitutive elements in the irradiated area with formed HSFLs were almost unchanged.

  19. Study of new states in visible light active W, N co-doped TiO{sub 2} photo catalyst

    SciTech Connect (OSTI)

    Sajjad, Ahmed Khan Leghari; Shamaila, Sajjad; Zhang, Jinlong

    2012-11-15

    Highlights: ? Visible light efficient W, N co-doped TiO{sub 2} photo catalysts are prepared by solgel. ? Oxygen vacancies are detected in the form of new linkages as N-Ti-O, N-W-O, Ti-O-N and W-O-N. ? W, N co-doped titania has new energy states which narrows the band gap effectively. ? Oxygen vacancies are proved to be the cause for high photo catalytic activity. ? W and N co-doping plays the major role to make the composite thermally stable. -- Abstract: The visible light efficient W, N co-doped TiO{sub 2} photo catalysts are prepared by solgel method. New linkages of N, W and O are formed as N-Ti-O, N-W-O, Ti-O-N and W-O-N. Electron paramagnetic resonance illustrates the presence of oxygen vacancies in W, N co-doped TiO{sub 2} acting as trapping agencies for electrons to produce active species. X-ray photoelectron spectroscopy confirms the presence of new energy states. New linkages and oxygen vacancies are proved to be the main cause for the improved photo catalytic performances. W, N co-doped TiO{sub 2} has new energy states which narrow the band gap effectively. W, N co-doped TiO{sub 2} is thermally stable and retains its anatase phase up to 900 C. 4.5% W, N co-doped TiO{sub 2} showed superior activity for the degradation of Rhodamine B and 2,4-dichlorophenol as compared to pure titania, Degussa P-25, traditional N-doped TiO{sub 2} and pure WO{sub 3}.

  20. Dielectric and photocatalytic properties of sulfur doped TiO{sub 2} nanoparticles prepared by ball milling

    SciTech Connect (OSTI)

    Jalalah, Mohammed; Faisal, M.; Bouzid, Houcine; Ismail, Adel A.; Al-Sayari, Saleh A.

    2013-09-01

    Graphical abstract: - Highlights: Designing of visible light responsive photocatalyst utilizing ball milling. Sulphur used as dopant in commercial TiO{sub 2} P25 at different atomic percentage. S doping resulted in an intense increase in absorption in the visible light region. Newly design photocatalyst exhibited excellent photocatalytic performance. 0.11 at.% S-doped TiO{sub 2} shows 3-times higher activity than that of TiO{sub 2} P25. - Abstract: Sulfur (S) doped commercial TiO{sub 2} P-25 has been achieved by changing the amount of thiourea using ball milling technique. The results of XRD clearly reveal biphasial anatase and rutile mixtures for all prepared samples and doping of S does not change the morphology of the TiO{sub 2}. The optical absorption edge of S-doped TiO{sub 2} was red shifted with indirect bandgap energy of 2.8 eV. The dielectric studies confirm that the dielectric constant of TiO{sub 2} increases after doping, however it becomes more conductive. Newly designed S-doped TiO{sub 2} photocatalysts exhibited excellent photocatalytic performance for the degradation of methylene blue (MB) under visible light. The overall photocatalytic activity of 0.11 at.% S-doped TiO{sub 2} was significantly 3-times higher than that of commercial TiO{sub 2} P-25 and complete degradation of MB has taken place after 90 min of irradiation under visible light while only 35% dye degraded when the reaction has been carried out in the presence of undoped TiO{sub 2}.

  1. Metallic glass alloys of Zr, Ti, Cu and Ni

    DOE Patents [OSTI]

    Lin, X.; Peker, A.; Johnson, W.L.

    1997-04-08

    At least quaternary alloys form metallic glass upon cooling below the glass transition temperature at a rate less than 10{sup 3} K/s. Such alloys comprise titanium from 19 to 41 atomic percent, an early transition metal (ETM) from 4 to 21 atomic percent and copper plus a late transition metal (LTM) from 49 to 64 atomic percent. The ETM comprises zirconium and/or hafnium. The LTM comprises cobalt and/or nickel. The composition is further constrained such that the product of the copper plus LTM times the atomic proportion of LTM relative to the copper is from 2 to 14. The atomic percentage of ETM is less than 10 when the atomic percentage of titanium is as high as 41, and may be as large as 21 when the atomic percentage of titanium is as low as 24. Furthermore, when the total of copper and LTM are low, the amount of LTM present must be further limited. Another group of glass forming alloys has the formula (ETM{sub 1{minus}x}Ti{sub x}){sub a} Cu{sub b} (Ni{sub 1{minus}y}Co{sub y}){sub c} wherein x is from 0.1 to 0.3, y{center_dot}c is from 0 to 18, a is from 47 to 67, b is from 8 to 42, and c is from 4 to 37. This definition of the alloys has additional constraints on the range of copper content, b. 2 figs.

  2. Evolution of structure in Na{sub 0.5}Bi{sub 0.5}TiO{sub 3} single...

    Office of Scientific and Technical Information (OSTI)

    Evolution of structure in Nasub 0.5Bisub 0.5TiOsub 3 single crystals with BaTiOsub 3 Citation Details In-Document Search Title: Evolution of structure in Nasub 0.5Bisub ...

  3. Enhanced photocatalytic activity of TiO{sub 2} nanobarbed fibers treated with atmospheric pressure plasma using O{sub 2} gas

    SciTech Connect (OSTI)

    Lee, Hyun-Uk; Ahn, Kyun; Jeong, Se-Young; Cho, Chae-Ryong; Kim, Jong-Pil; Bae, Jong-Seong; Kim, Hyun-Gyu; Kwon, Se-Hun; Lee, Hyung Woo

    2010-11-29

    TiO{sub 2} nanobarbed fibers (NBFs) were prepared by growing rutile TiO{sub 2} nanorods on anatase TiO{sub 2} nanofibers via electrospinning and hydrothermal reaction processes. There was a large increase in the photocatalytic activity of O{sub 2}-plasma-treated (OP)-TiO{sub 2} NBFs relative to that of the TiO{sub 2} NBFs; this is due to the hydroxylation of the surface of the TiO{sub 2} NBFs by OP treatment. The repeatability of the photocatalytic activity of the OP-TiO{sub 2} NBFs was found to be high and the decolorization rate after ten cycles was 88.3% of the initial value. These results indicate that OP-TiO{sub 2} NBFs have great potential for use as a photocatalyst.

  4. Correlating hydrogen oxidation and evolution activity on platinum at different pH with measured hydrogen binding energy

    SciTech Connect (OSTI)

    Sheng, WC; Zhuang, ZB; Gao, MR; Zheng, J; Chen, JGG; Yan, YS

    2015-01-08

    The hydrogen oxidation/evolution reactions are two of the most fundamental reactions in distributed renewable electrochemical energy conversion and storage systems. The identification of the reaction descriptor is therefore of critical importance for the rational catalyst design and development. Here we report the correlation between hydrogen oxidation/evolution activity and experimentally measured hydrogen binding energy for polycrystalline platinum examined in several buffer solutions in a wide range of electrolyte pH from 0 to 13. The hydrogen oxidation/evolution activity obtained using the rotating disk electrode method is found to decrease with the pH, while the hydrogen binding energy, obtained from cyclic voltammograms, linearly increases with the pH. Correlating the hydrogen oxidation/evolution activity to the hydrogen binding energy renders a monotonic decreasing hydrogen oxidation/evolution activity with the hydrogen binding energy, strongly supporting the hypothesis that hydrogen binding energy is the sole reaction descriptor for the hydrogen oxidation/evolution activity on monometallic platinum.

  5. Microstructure evolution in solution treated Ti15Mo alloy processed by high pressure torsion

    SciTech Connect (OSTI)

    Jane?ek, Milo; ?ek, Jakub; Strsk, Josef; Vclavov, Kristna; Hruka, Petr; Polyakova, Veronika; Gatina, Svetlana; Semenova, Irina

    2014-12-15

    Microstructure evolution and mechanical properties of ultra-fine grained Ti15Mo alloy processed by high pressure torsion were investigated. High pressure torsion straining resulted in strong grain refinement as-observed by transmission electron microscopy. Microhardness and light microscopy showed two distinct regions (i) a central region with radial material flow and low microhardness (340 HV) and (ii) a peripheral region with rotational material flow and high microhardness (430 HV). Positron annihilation spectroscopy showed that the only detectable defects in the material are dislocations, whose density increases with the radial distance and the number of high pressure torsion revolutions. The local chemical environment around defects does not differ significantly from the average composition. - Highlights: Beta-Ti alloy Ti15Mo was processed by high pressure torsion (HPT). Lateral inhomogeneity of the microstructure and microhardness was found. Dislocations are the only lattice defects detectable by positron annihilation. Molybdenum is not preferentially segregated along dislocation cores.

  6. Surface roughness and interface width scaling of magnetron sputter deposited Ni/Ti multilayers

    SciTech Connect (OSTI)

    Maidul Haque, S.; Biswas, A.; Tokas, R. B.; Bhattacharyya, D.; Sahoo, N. K.; Bhattacharya, Debarati

    2013-09-14

    Using an indigenously built r.f. magnetron sputtering system, several single layer Ti and Ni films have been deposited at varying deposition conditions. All the samples have been characterized by Grazing Incidence X-ray Reflectivity (GIXR) and Atomic Force Microscopy to estimate their thickness, density, and roughness and a power law dependence of the surface roughness on the film thickness has been established. Subsequently, at optimized deposition condition of Ti and Ni, four Ni/Ti multilayers of 11-layer, 21-layer, 31-layer, and 51-layer having different bilayer thickness have been deposited. The multilayer samples have been characterized by GIXR and neutron reflectivity measurements and the experimental data have been fitted assuming an appropriate sample structure. A power law correlation between the interface width and bilayer thickness has been observed for the multilayer samples, which was explained in the light of alternate roughening/smoothening of multilayers and assuming that at the interface the growth restarts every time.

  7. Microstructural evaluation of NiTi-based films deposited by magnetron sputtering

    SciTech Connect (OSTI)

    Cr?ciunescu, Corneliu M. Mitelea, Ion Bud?u, Victor; Ercu?a, Aurel

    2014-11-24

    Shape memory alloy films belonging to the NiTi-based systems were deposited on heated and unheated substrates, by magnetron sputtering in a custom made system, and their structure and composition was analyzed using electron microscopy. Several substrates were used for the depositions: glass, Cu-Zn-Al, Cu-Al-Ni and Ti-NiCu shape memory alloy ribbons and kapton. The composition of the Ti-Ni-Cu films showed limited differences, compared to the one of the target and the microstructure for the DC magnetron sputtering revealed crystallized structure with features determined on peel off samples from a Si wafer. Both inter and transcrystalline fractures were observed and related to the interfacial stress developed on cooling from deposition temperature.

  8. Resistive switching phenomena in TiO{sub x} nanoparticle layers for memory applications

    SciTech Connect (OSTI)

    Goren, Emanuelle; Tsur, Yoed; Ungureanu, Mariana; Zazpe, Raul; Rozenberg, Marcelo; Hueso, Luis E.; Casanova, Flix; Stoliar, Pablo

    2014-10-06

    Electrical characteristics of a Co/ TiO{sub x}/Co resistive memory device, fabricated by two different methods, are reported. In addition to crystalline TiO{sub 2} layers fabricated via conventional atomic layer deposition (ALD), an alternative method has been examined, where TiO{sub x} nanoparticle layers were fabricated via sol-gel. The different devices have shown different hysteresis loops with a unique crossing point for the sol-gel devices. A simple qualitative model is introduced to describe the different current-voltage behaviours by suggesting only one active metal-oxide interface for the ALD devices and two active metal-oxide interfaces for the sol-gel devices. Furthermore, we show that the resistive switching behaviour could be easily tuned by proper interface engineering and that despite having a similar active material, different fabrication methods can lead to dissimilar resistive switching properties.

  9. Eutectic bonding of a Ti sputter coated, carbon aerogel wafer to a Ni foil

    SciTech Connect (OSTI)

    Jankowski, A.F.; Hayes, J.P.; Kanna, R.L.

    1994-06-01

    The formation of high energy density, storage devices is achievable using composite material systems. Alternate layering of carbon aerogel wafers and Ni foils with rnicroporous separators is a prospective composite for capacitor applications. An inherent problem exists to form a physical bond between Ni and the porous carbon wafer. The bonding process must be limited to temperatures less than 1000{degrees}C, at which point the aerogel begins to degrade. The advantage of a low temperature eutectic in the Ni-Ti alloy system solves this problem. Ti, a carbide former, is readily adherent as a sputter deposited thin film onto the carbon wafer. A vacuum bonding process is then used to join the Ni foil and Ti coating through eutectic phase formation. The parameters required for successfld bonding are described along with a structural characterization of the Ni foil-carbon aerogel wafer interface.

  10. Thermoelectricity of Nanocomposites Containing TiO2CoO Coaxial Nanocables

    SciTech Connect (OSTI)

    Su, L.; Zhang, L.; Gana, Y.X.

    2011-04-01

    TiO{sub 2}-CoO coaxial nanocables were deposited into anodic aluminum oxide (AAO) nanoporous templates to form nanocomposite materials. Electron microscopic analysis was conducted to reveal their structures. Seebeck coefficients of the composites were measured. The highest absolute value of Seebeck coefficient is 393 {micro}V K{sup -1} for the TiO{sub 2} nanotube-filled AAO. The TiO{sub 2}-CoO coaxial nanocable-filled AAO has a lower absolute value of 300 {micro}V K{sup -1}. Both composites showed n-type behavior. The effect of Ag nanoparticles addition on the thermoelectric behavior was also examined.

  11. Industrial Application of Thin Films (TiAl)N Deposited on Thermo-Wells

    SciTech Connect (OSTI)

    Velez, G.; Jaramillo, S.; Arango, Y. C.; Devia, D.; Quintero, J.; Devia, A.

    2006-12-04

    The thermo-well is formed by two layers, one layer is a ceramic and the other layer is anviloy (comprised tungsten). They are used to coat the thermocouple in the control temperature system during the Aluminum-Silicon alloy melting process. After two weeks of continuous work at 750 deg. C of temperature (the alloy temperature), a high wear in this material is observed, affecting the ceramic. (TiAl)N thin films are deposited directly on the anviloy substrates by the PAPVD (Plasma Assisted Physics Vapor Deposition) in arc pulsed technique, using a TiAl target in a mono-vaporizer system, composed by a reactor and a power controlled system. Two opposite electrodes are placed into the reactor and discharge is produced by a controlled power system. The XRD (X-ray diffraction) patterns show the presence of the (TiAl)N thin film peaks. The morphological characteristics are studied by the scanning probe microscopy (SPM)

  12. Thermo-mechanical processing (TMP) of Ti-48Al-2Nb-2Cr based alloys

    SciTech Connect (OSTI)

    Fuchs, G.E.

    1995-02-01

    The effects of heat treatment and deformation processing on the microstructures and properties of {gamma}-TiAl based alloys produced by ingot metallurgy (I/M) and powder metallurgy (P/M) techniques were examined. The alloy selected for this work is the second generation {gamma}-TiAl based alloy -- Ti-48Al-2Nb-2Cr (at %). Homogenization of I/M samples was performed at a variety of temperatures, followed by hot working by isothermal forging. P/M samples were prepared from gas atomized powders, consolidated by both HIP and extrusion and some of the HIPed material was then hot worked by isothermal forging. The effects of processing, heat treatment and hot working on the microstructures and properties will be discussed.

  13. Process of making titanium carbide (TiC) nano-fibrous felts

    DOE Patents [OSTI]

    Fong, Hao; Zhang, Lifeng; Zhao, Yong; Zhu, Zhengtao

    2015-01-13

    A method of synthesizing mechanically resilient titanium carbide (TiC) nanofibrous felts comprising continuous nanofibers or nano-ribbons with TiC crystallites embedded in carbon matrix, comprising: (a) electrospinning a spin dope for making precursor nanofibers with diameters less than 0.5 J.Lm; (b) overlaying the nanofibers to produce a nanofibrous mat (felt); and then (c) heating the nano-felts first at a low temperature, and then at a high temperature for making electrospun continuous nanofibers or nano-ribbons with TiC crystallites embedded in carbon matrix; and (d) chlorinating the above electrospun nano-felts at an elevated temperature to remove titanium for producing carbide derived carbon (CDC) nano-fibrous felt with high specific surface areas.

  14. Tunable synthesis of TiO{sub 2}/SrO core/shell nanowire arrays with enhanced photocatalytic activity

    SciTech Connect (OSTI)

    Wang, Wenqi; Yang, Jie; Gong, Yingpeng; Hong, Hanlie

    2013-01-15

    Graphical abstract: TiO{sub 2} nanowires with tunable SrO shell layer are easily fabricated. The core/shell structure can enhance the photocatalytic activity of TiO{sub 2} nanowires and restrict the recombination of the electrons/holes. Display Omitted Highlights: ? A facile method to fabricate TiO{sub 2}/SrO core-shell nanowire array is reported. ? The thickness of SrO shell layer can be tunable by adjusting the dipping time. ? TiO{sub 2}/SrO core/shell nanowires shows enhanced photocatalytic activity. -- Abstract: We report a simple method to fabricate well-aligned TiO{sub 2}/SrO core/shell nanowire arrays. The core/shell structure is confirmed to have crystalline TiO{sub 2} nanowires core and amorphous SrO shell layer. The shell is composed of SrO with tunable thickness. Photocatalytic activity measurement shows that TiO{sub 2}/SrO core/shell nanowire arrays outperform uncovered TiO{sub 2} nanowires. Such core/shell nanowire arrays have potential applications for photovoltaic devices and as high performance photocatalyst.

  15. Pulsed laser-induced oxygen deficiency at TiO{sub 2} surface: Anomalous structure and electrical transport properties

    SciTech Connect (OSTI)

    Nakajima, Tomohiko; Tsuchiya, Tetsuo; Kumagai, Toshiya

    2009-09-15

    We have studied pulsed laser-induced oxygen deficiencies at rutile TiO{sub 2} surfaces. The crystal surface was successfully reduced by excimer laser irradiation, and an oxygen-deficient TiO{sub 2-{delta}} layer with 160 nm thickness was formed by means of ArF laser irradiation at 140 mJ/cm{sup 2} for 2000 pulses. The TiO{sub 2-{delta}} layer fundamentally maintained a rutile structure, though this structure was distorted by many stacking faults caused by the large oxygen deficiency. The electrical resistivity of the obtained TiO{sub 2-{delta}} layer exhibited unconventional metallic behavior with hysteresis. A metal-insulator transition occurred at 42 K, and the electrical resistivity exceeded 10{sup 4} OMEGA cm below 42 K. This metal-insulator transition could be caused by bipolaronic ordering derived from Ti-Ti pairings that formed along the stacking faults. The constant magnetization behavior observed below 42 K is consistent with the bipolaronic scenario that has been observed previously for Ti{sub 4}O{sub 7}. These peculiar electrical properties are strongly linked to the oxygen-deficient crystal structure, which contains many stacking faults formed by instantaneous heating during excimer laser irradiation. - Graphical abstract: A pulsed laser-irradiated TiO{sub 2-{delta}} substrate showed an unconventional metallic phase, with hysteresis over a wide range of temperatures and a metal-insulator transition at 42 K.

  16. A reaction mechanism for titanium nitride CVD from TiCl{sub 4} and NH{sub 3}

    SciTech Connect (OSTI)

    Larson, R.S.; Allendorf, M.D.

    1995-12-01

    A gas-phase and surface reaction mechanism for the CVD of TiN from TiCl{sub 4} and NH{sub 3} is proposed. The only gas-phase process is complex formation, which can compete with deposition. The surface mechanism postulates the stepwise elimination of Cl and H atoms from TiCl{sub 4} and NH{sub 3}, respectively, to form solid TiN and gaseous HCl. The mechanism also accounts for the change in oxidation state of Ti by allowing for liberation of N{sub 2}. Provided that the surface composition is at steady state, the stoichiometry of the overall reaction is reproduced exactly. In addition, the global kinetic law predicted by the mechanism is successfully fit to new deposition data from a rotating disk reactor and is shown to be consistent with literature results.

  17. Thermal protection of H13 steel by growth of (TiAl)N films by PAPVD pulsed arc technique

    SciTech Connect (OSTI)

    Jimenez, H.; Devia, D.M.; Benavides, V.; Devia, A. Arango, Y.C.; Arango, P.J.; Velez, J.M.

    2008-08-15

    (TiAl)N Films were grown on H13 steel by a plasma assisted repetitive pulsed arc discharge. To grow the coatings, a TiAl sintered cathode was used, 50% Ti-50% Al. The deposition system consists of a reaction chamber with two electrodes placed face to face. A pulsed power supply, which allows for control of parameters like time active arc, time between arcs, arc energy, and others, is used to generate the discharge. Thermal changes were carried out on H13 steel before and after growing the (TiAl)N films. X-ray diffraction (XRD) was employed to study the coatings, observing the H13 steel and (TiAl)N oxidation temperature. Morphological characteristics were analyzed by means of an Atomic Force Microscopy (AFM). Scanning electron microscopy (SEM) revealed the surface chemical composition of the films and morphological details of the samples.

  18. Characterizations Of Precipitate Phases In a Ti-Ni-Pd Alloy

    SciTech Connect (OSTI)

    Yang, Fan; Kovarik, Libor; Phillips, Patrick J.; Noebe, Ronald D.; Mills, M. J.

    2012-06-01

    Precipitates in the Ti46Ni37.5Pd16.5 alloy were investigated by electron diffraction and high-resolution scanning transmission electron microscopy. The phase content and stability were determined at several different temperatures and times. Aging at 400 C for an hour results in a new phase, which is consumed by P-phase at longer aging time. At 450 C, the new phase appears first, and then coexists with P-phase. At 500 C, the entire alloy transformed into the new phase. At 550 C, Ti3(Ni,Pd)4 phase begins to form.

  19. An Experimental and Theoretical Study of Ti-6Al-4V to Multi-mbar Pressures

    SciTech Connect (OSTI)

    MacLeod, S G; Tegner, B E; Cynn, H; Evans, W J; Proctor, J; McMahon, M I; Ackland, G J

    2012-03-14

    We report results from an experimental and theoretical study of the ternary alloy Ti-6Al-4V to 221 GPa. We observe a phase transition to the hexagonal {omega}-phase at approximately 30 GPa, and then a further transition to the cubic {beta}-phase starting at 94-99 GPa. We do not observe the orthorhombic {gamma} and {delta} phases reported previously in pure Ti. Computational studies show that this sequence is possible only if there is significant local atomic ordering during the compression process, yet insufficient atomic diffusion to reach the phase separated thermodynamic equilibrium state.

  20. ZnO/porous-Si and TiO{sub 2}/porous-Si nanocomposite nanopillars

    SciTech Connect (OSTI)

    Wang, Dong, E-mail: dong.wang@tu-ilmenau.de; Yan, Yong; Schaaf, Peter [Chair Materials for Electronics, Institute of Materials Engineering and Institute of Micro- and Nanotechnologies MacroNano, TU Ilmenau, Gustav-Kirchhoff-Str. 5, 98693 Ilmenau (Germany); Sharp, Thomas [Oxford Instruments Plasma Technology Ltd., Yatton, Bristol BS49 4AP (United Kingdom); Schnherr, Sven; Ronning, Carsten [Institute for Solid State Physics, Friedrich Schiller University Jena, Max-Wien-Platz 1, 07743 Jena (Germany); Ji, Ran [SUSS MicroTec Lithography GmbH, Schleissheimer Str. 90, 85748 Garching (Germany)

    2015-01-01

    Porous Si nanopillar arrays are used as templates for atomic layer deposition of ZnO and TiO{sub 2}, and thus, ZnO/porous-Si and TiO{sub 2}/porous-Si nanocomposite nanopillars are fabricated. The diffusion of the precursor molecules into the inside of the porous structure occurs via Knudsen diffusion and is strongly limited by the small pore size. The luminescence of the ZnO/porous-Si nanocomposite nanopillars is also investigated, and the optical emission can be changed and even quenched after a strong plasma treatment. Such nanocomposite nanopillars are interesting for photocatalysis and sensors.

  1. Visible Light Photocatalysis via CdS/TiO2Nanocomposite Materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Srinivasan, Sesha S.; Wade, Jeremy; Stefanakos, Elias K.

    2006-01-01

    Nanostructured colloidal semiconductors with heterogeneous photocatalytic behavior have drawn considerable attention over the past few years. This is due to their large surface area, high redox potential of the photogenerated charge carriers, and selective reduction/oxidation of different classes of organic compounds. In the present paper, we have carried out a systematic synthesis of nanostructured CdS-TiO2via reverse micelle process. The structural and microstructural characterizations of the as-prepared CdS-TiO2nanocomposites are determined using XRD and SEM-EDS techniques. The visible light assisted photocatalytic performance is monitored by means of degradation of phenol in water suspension.

  2. Discovery of a ternary pseudobrookite phase in the earth-abundant TiZnO

    Office of Scientific and Technical Information (OSTI)

    system (Journal Article) | SciTech Connect Discovery of a ternary pseudobrookite phase in the earth-abundant TiZnO system Citation Details In-Document Search Title: Discovery of a ternary pseudobrookite phase in the earth-abundant TiZnO system Authors: Perry, Nicola H. ; Stevanovic, Vladan ; Lime, Linda Y. ; Mason, Thomas O. [1] ; CSM) [2] ; NWU) [2] ; MIT) [2] + Show Author Affiliations Stanford ( Publication Date: 2016-02-11 OSTI Identifier: 1238274 Resource Type: Journal Article Resource

  3. FIRST-PRINCIPLES PHASE STABILITY IN THE TI-V ALLOY SYSTEM (Journal Article)

    Office of Scientific and Technical Information (OSTI)

    | SciTech Connect FIRST-PRINCIPLES PHASE STABILITY IN THE TI-V ALLOY SYSTEM Citation Details In-Document Search Title: FIRST-PRINCIPLES PHASE STABILITY IN THE TI-V ALLOY SYSTEM Authors: Soderlind, P ; Landa, A ; Yang, L H ; Teweldebrhan, A Publication Date: 2013-04-11 OSTI Identifier: 1108866 Report Number(s): LLNL-JRNL-635374 DOE Contract Number: W-7405-ENG-48 Resource Type: Journal Article Resource Relation: Journal Name: Journal of Alloys and Compounds, vol. 581, na, December 25, 2013,

  4. Mixed-sputter deposition of Ni-Ti-Cu shape memory films

    SciTech Connect (OSTI)

    Krulevitch, P.; Ramsey, P.B.; Makowiecki, D.M.; Lee, A.P.; Northrup, M.A.; Johnson, G.C.

    1994-05-01

    Ni-Ti-Cu shape memory films were mixed-sputter deposited from separate nickel, titanium, and copper targets, providing increased compositional flexibility. Shape memory characteristics, examined for films with 7 at. % Cu and 41--51 at. % Tl, were determined with temperature controlled substrate curvature measurements, and microstructure was studied with transmission electron microscopy. The Ni-Ti-Cu films were found to have shape memory properties comparable to bulk materials, with transformation temperatures between 20 and 62{degree}C, a 10--13{degree}C hysteresis, and up to 330 MPa recoverable stress.

  5. Role of polaron hopping in leakage current behavior of a SrTiO{sub 3}

    Office of Scientific and Technical Information (OSTI)

    single crystal (Journal Article) | SciTech Connect Role of polaron hopping in leakage current behavior of a SrTiO{sub 3} single crystal Citation Details In-Document Search Title: Role of polaron hopping in leakage current behavior of a SrTiO{sub 3} single crystal We studied the ionic/electronic transport and resistance degradation behavior of dielectric oxides by solving the electrochemical transport equations. Here, we took into account the non-periodical boundary conditions for the

  6. Ti3CrCu4: A possible 2-D ferromagnetic spin fluctuating system (Journal

    Office of Scientific and Technical Information (OSTI)

    Article) | DOE PAGES Ti3CrCu4: A possible 2-D ferromagnetic spin fluctuating system Title: Ti3CrCu4: A possible 2-D ferromagnetic spin fluctuating system Authors: Dhar, S. K. [1] ; Provino, A. [2] ; Manfrinetti, P. [2] ; Kulkarni, R. [1] ; Goyal, Neeraj [1] ; Paudyal, D. [3] + Show Author Affiliations Department of Condensed Matter Physics & Materials Science, T.I.F.R., Homi Bhabha Road, Colaba, Mumbai, 400005, India Department of Chemistry, University of Genova, Via Dodecaneso 31, 16146

  7. Preparation, characterization, and photocatalytic studies on anatase nano-TiO{sub 2} at internal air lift circulating photocatalytic reactor

    SciTech Connect (OSTI)

    Xu, Hang Li, Mei; Jun, Zhang

    2013-09-01

    Graphical abstract: The micro morphological structure of the nano-TiO{sub 2} particles was also observed with TEM, as shown in figure. The TEM images clearly exhibited the homogeneous microstructure of particles with a size of around 1015 nm. - Highlights: Nano-TiO{sub 2} was prepared by complex techniques of solgel, micro-emulsion and solvent thermal. The size of TiO{sub 2} was nano level and uniformity. Nano-TiO{sub 2} exhibited high photo-catalytic activity at internal air lift circulating reactor. The best nano-TiO{sub 2} dosage was obtained. - Abstract: Anatase nano-titania (TiO{sub 2}) powder was prepared by using a solgel process mediated in reverse microemulsion combined with a solvent thermal technique. The structures of the obtained TiO{sub 2} were characterized by TG-DSC, XRD, TEM. The photocatalytic decomposition of methylene blue (MB) on nano-TiO{sub 2} was studied by using an internal air lift circulating photocatalytic reactor. The results show that the anatase structure appears in the calcination temperature range of 400510 C, while the transformation of anatase into rutile takes place above 510 C. The homogeneous microstructure of nano-TiO{sub 2} particles was obtained with a size of around 1015 nm. In the photocatalytic performance, degradation process follows pseudo first order kinetics with different dosages of photocatalyst and initial MB concentrations and optimal TiO{sub 2} dosage is 0.1 g/L with neutral medium.

  8. Effect of pulse frequency on microstructural, nanomechanical, and wear properties of electrodeposited NiTiN composite coatings

    SciTech Connect (OSTI)

    Xia, Fafeng; Tian, Jiyu; Ma, Chunyang Guo, Xue; Potts, Matt

    2014-12-21

    The current paper reports successful syntheses of NiTiN composite coatings by pulse electrodeposition. The effect of pulse frequency on the microstructures, nanomechanical, and wear properties of the coatings was investigated using transmission electron microscopy, Xray diffraction, nanoindenter, scanning electron microscopy, and wear test instrument. The results showed that the NiTiN composite coating prepared at the pulse frequency of 100?Hz showed the presence of a less number of TiN particles and some degrees of aggregation in micro-regions. By contrast, in the NiTiN coating deposited at the pulse frequency of 500?Hz, the TiN particles were large in number and dispersed homogeneously, thereby, offering the coating a uniform and fine structure. The average grain diameters of Ni and TiN in the coating prepared at 100?Hz were 154.7 and 44.8?nm, respectively, whereas those for the coating prepared at 500?Hz were 67.3 and 25.9?nm, respectively. The maximum TiN content in the Ni-TiN coating deposited at 800?Hz was approximately 10.5?wt.?%. The maximum microhardness and the Young's modulus values for the NiTiN composite coatings deposited at 800?Hz were 35.7?GPa and 167.4?GPa, respectively. Furthermore, the NiTiN composite coating prepared at 100?Hz had more severe damages, whereas the morphologies of worn surface of the coatings deposited at 500?Hz and 800?Hz were smooth and only a few small pits appeared on the surface.

  9. In situ X-ray diffraction strain-controlled study of TiNbZr and TiNbTa shape memory alloys: crystal lattice and transformation features

    SciTech Connect (OSTI)

    Dubinskiy, S.; Prokoshkin, S.; Brailovski, V.; Inaekyan, K.; Korotitskiy, A.

    2014-02-15

    Phase and structure transformations in biomedical Ti21.8Nb6.0Zr (TNZ) and Ti19.7Nb5.8Ta (TNT) shape memory alloys (at.%) under and without load in the ? 150 to 100 S temperature range are studied in situ using an original tensile module for a low-temperature chamber of an X-ray diffractometer. Alpha?- and beta-phase lattice parameters, the crystallographic resource of recovery strain, phase and structure transformation sequences, and microstress appearance and disappearance are examined, compared and discussed. For both alloys, the crystallographic resource of recovery strain decreases with temperature increase to become 4.5% for TNZ and 2.5% for TNT alloy (at RT). Loading at low temperatures leads to additional ??-phase formation and reorientation. Heating under load, as compared to strain-free heating, affects the reverse transformation sequence of both alloys in different ways. For TNZ alloy, strain-free heating results in simultaneous ??? and ???? transformations, whereas during heating under stress, they are sequential: ? + ???? precedes ????. For TNT alloy, strain-free heating results in reverse ???? transformation, whereas during heating under stress, ???? transformation is preceded by ??-phase reorientation. - Highlights: Comparative in situ XRD analysis of TiNbZr(Ta) shape memory alloys is realized. Lattice parameters of ?- and ??-phases are calculated in the ? 150 to + 100 C range. The higher the temperature, the lower the ???? transformation strain. Loading at low temperatures results in ??-phase formation and reorientation. Transformation sequences upon heating with and without loading are different.

  10. In-situ imaging of the nucleation and growth of epitaxial anatase TiO2(001) films on SrTiO3(001)

    SciTech Connect (OSTI)

    Du, Yingge; Kim, Dong Jun; Kaspar, Tiffany C.; Chamberlin, Sara E.; Lyubinetsky, Igor; Chambers, Scott A.

    2012-09-30

    The growth of TiO2 anatase films on Nb doped SrTiO3(001) by oxygen-assisted molecular beam epitaxy has been studied in-situ by scanning tunneling microscopy. We show that the initial growth follows the Stranski-Krastanov mode, where islands form on top of a wetting layer consisting of two monolayers (ML) of TiO2. The epitaxial islands subsequently nucleate and coalescence into large commonly-oriented crystallites. The (4x4) reconstruction observed by reflection high-energy electron diffraction (RHEED) is shown to result from the coexistence of individual (4x1) and (1x4) reconstructions present on different crystallite surfaces. The anatase grows in units of bilayers, resulting in a step height of 2 ML (~0.5 nm). This result explains the fact that the measured period of the RHEED specular-beam intensity oscillations corresponds to the time required for deposition of 2 ML. Ar ion sputtering and UHV annealing results in a transformation to coexisting (4x1) and (1x4) reconstructed terraces on individual crystallites, as commonly observed by ex-situ STM studies.

  11. Interfacial dislocations in (111) oriented (Ba0.7Sr0.3)TiO3 films on SrTiO3 single crystal

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Shen, Xuan; Yamada, Tomoaki; Lin, Ruoqian; Kamo, Takafumi; Funakubo, Hiroshi; Wu, Di; Xin, Huolin L.; Su, Dong

    2015-10-08

    In this study, we have investigated the interfacial structure of epitaxial (Ba,Sr)TiO3 films grown on (111)-oriented SrTiO3 single-crystal substrates using transmission electron microscopy (TEM) techniques. Compared with the (100) epitaxial perovskite films, we observe dominant dislocation half-loop with Burgers vectors of a<110> comprised of a misfit dislocation along <112>, and threading dislocations along <110> or <100>. The misfit dislocation with Burgers vector of a <110> can dissociate into two ½ a <110> partial dislocations and one stacking fault. We found the dislocation reactions occur not only between misfit dislocations, but also between threading dislocations. Via three-dimensional electron tomography, we retrievedmore » the configurations of the threading dislocation reactions. The reactions between threading dislocations lead to a more efficient strain relaxation than do the misfit dislocations alone in the near-interface region of the (111)-oriented (Ba0.7Sr0.3)TiO3 films.« less

  12. Planet hunters. VII. Discovery of a new low-mass, low-density planet (PH3 C) orbiting Kepler-289 with mass measurements of two additional planets (PH3 B and D)

    SciTech Connect (OSTI)

    Schmitt, Joseph R.; Fischer, Debra A.; Wang, Ji; Margossian, Charles; Brewer, John M.; Giguere, Matthew J. [Department of Astronomy, Yale University, New Haven, CT 06511 (United States); Agol, Eric [Department of Astronomy, Box 351580, University of Washington, Seattle, WA 98195 (United States); Deck, Katherine M. [Department of Physics and Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139 (United States); Rogers, Leslie A. [Department of Astronomy and Division of Geological and Planetary Sciences, California Institute of Technology, MC249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Gazak, J. Zachary [Institute for Astronomy, University of Hawaii, 2680 Woodlawn Drive, Honolulu, HI 96822 (United States); Holman, Matthew J. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Jek, Kian J.; Omohundro, Mark R.; Winarski, Troy; Lintott, Chris; Simpson, Robert [Oxford Astrophysics, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH (United Kingdom); Lynn, Stuart; Parrish, Michael [Adler Planetarium, 1300 South Lake Shore Drive, Chicago, IL 60605 (United States); Schawinski, Kevin [Institute for Astronomy, Department of Physics, ETH Zurich, Wolfgang-Pauli-Strasse 16, CH-8093 Zurich (Switzerland); Schwamb, Megan E., E-mail: joseph.schmitt@yale.edu [Institute of Astronomy and Astrophysics, Academia Sinica: 11F Astronomy-Mathematics Building, National Taiwan University. No.1, Sec. 4, Roosevelt Road, Taipei 10617, Taiwan (China); and others

    2014-11-10

    We report the discovery of one newly confirmed planet (P = 66.06 days, R {sub P} = 2.68 0.17 R {sub ?}) and mass determinations of two previously validated Kepler planets, Kepler-289 b (P = 34.55 days, R {sub P} = 2.15 0.10 R {sub ?}) and Kepler-289-c (P = 125.85 days, R {sub P} = 11.59 0.10 R {sub ?}), through their transit timing variations (TTVs). We also exclude the possibility that these three planets reside in a 1:2:4 Laplace resonance. The outer planet has very deep (?1.3%), high signal-to-noise transits, which puts extremely tight constraints on its host star's stellar properties via Kepler's Third Law. The star PH3 is a young (?1 Gyr as determined by isochrones and gyrochronology), Sun-like star with M {sub *} = 1.08 0.02 M {sub ?}, R {sub *} = 1.00 0.02 R {sub ?}, and T {sub eff} = 5990 38 K. The middle planet's large TTV amplitude (?5 hr) resulted either in non-detections or inaccurate detections in previous searches. A strong chopping signal, a shorter period sinusoid in the TTVs, allows us to break the mass-eccentricity degeneracy and uniquely determine the masses of the inner, middle, and outer planets to be M = 7.3 6.8 M {sub ?}, 4.0 0.9M {sub ?}, and M = 132 17 M {sub ?}, which we designate PH3 b, c, and d, respectively. Furthermore, the middle planet, PH3 c, has a relatively low density, ? = 1.2 0.3 g cm{sup 3} for a planet of its mass, requiring a substantial H/He atmosphere of 2.1{sub ?0.3}{sup +0.8}% by mass, and joins a growing population of low-mass, low-density planets.

  13. Evaluation of experimentally measured and model-calculated pH for rock-brine-CO2 systems under geologic CO2 sequestration conditions

    SciTech Connect (OSTI)

    Shao, Hongbo; Thompson, Christopher J.; Cantrell, Kirk J.

    2013-11-01

    pH is an essential parameter for understanding the geochemical reactions that occur in rock-brine-CO2 systems when CO2 is injected into deep geologic formations for long-term storage. Due to a lack of reliable experimental methods, most laboratory studies conducted under geological CO2 sequestration (GCS) conditions have relied on thermodynamic modeling to estimate pH. The accuracy of these model predictions is typically uncertain. In our previous work, we have developed a method for pH determination by in-situ spectrophotometry. In the present work, we expanded the applicable pH range for this method and measured the pH of several rock-brine-CO2 systems at GCS conditions for five rock samples collected from ongoing GCS demonstration projects. Experimental measurements were compared with pH values calculated using several geochemical modeling approaches. The effect of different thermodynamic databases on the accuracy of model prediction was evaluated. Results indicate that the accuracy of model calculations is rock-dependent. For rocks comprised of carbonate and sandstone, model results generally agreed well with experimentally measured pH; however, for basalt, significant differences were observed. These discrepancies may be due to the models failure to fully account for certain reaction occurring between the basalt minerals the CO2-saturated brine solutions.

  14. Structural and magnetic phase transitions inEuTi1-xNbxO3

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Li, Ling; Morris, James R.; Koehler, Michael R.; Dun, Zhiling; Zhou, Haidong; Yan, Jiaqiang; Mandrus, David; Keppens, Veerle

    2015-07-30

    We have investigated the structural and magnetic phase transitions in EuTi1-xNbxO3 (0 ≤ x ≤ 0.3) with synchrotron powder x-ray diffraction, resonant ultrasound spectroscopy, and magnetization measurements. Upon Nb doping, the Pm3¯m ↔ I4/mcm structural transition shifts to higher temperatures and the room temperature lattice parameter increases while the magnitude of the octahedral tilting decreases. In addition, Nb substitution for Ti destabilizes the antiferromagnetic ground state of the parent compound and long-range ferromagnetic order is observed in the samples with x ≥ 0.1. The structural transition in pure and doped compounds is marked by a dramatic steplike softening of themore »elastic moduli near TS , which resembles that of SrTiO3 and can be adequately modeled using the Landau free energy model employing the same coupling between strain and octahedral tilting order parameter as previously used to model SrTiO3.« less

  15. Theoretical study of cubic Rashba effect at SrTiO3 (001) surfaces

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Shanavas, Kavungal Veedu

    2016-01-11

    The origin of Rashba spin splitting in the two-dimensional electron gas at the (001) surface of SrTiO3 is studied using first-principles calculations and tight-binding model. Calculations of oxygen vacancies under virtual crystal approximation reveal a two-dimensional electron-gas subband structure similar to polar materials, consistent with observations on SrTiO3. Our studies also confirm that k dependence of the spin splitting is predominantly cubic in the surface Tit2g states, even though structural relaxations diminish the effect in dxy bands. A tight-binding model, explicitly including Tid and Op states as well as next-nearest-neighbor interactions, is derived to understand the first-principles results. Effective RashbamoreHamiltonians for the surface bands are derived using quasidegenerate perturbation theory and scenarios in which linear k contribution may be suppressed are discussed. Furthermore, the cubic terms in the Hamiltonian are found to be different from the model derived using k ? p theory, leading to different pseudospin symmetry in the Brillouin zone.less

  16. Structural and electrical characterization of CoTiN metal gates

    SciTech Connect (OSTI)

    Wongpiya, Ranida; Ouyang, Jiaomin; Chung, Chia-Jung; Duong, Duc T.; Clemens, Bruce; Deal, Michael; Nishi, Yoshio

    2015-02-21

    As the gate size continues to decrease in nanoscale transistors, having metal gates with amorphous or near amorphous structures can potentially reduce grain-induced work function variation. Furthermore, amorphous materials are known to have superior diffusion barrier properties, which can help prevent work function change due to the diffusion of metals in contact with the gate. In this work we show that with the addition of cobalt, thin films of polycrystalline TiN become more amorphous with a smaller grain size. Co{sub x}(TiN){sub 1-x} films, where x?=?6080%, appear to consist of nanocrystals embedded in an amorphous matrix, and are thermally stable with no significant crystallization up to an annealing temperature of at least 600?C. Reducing the nitrogen gas flow ratio during sputter deposition from 9% to 2.5% further decreases the films' crystallinity, which is apparent by more sparse and even smaller nanocrystals. In addition to being partially amorphous, these CoTiN films also exhibit good thermal stability, low resistivity, low roughness, and have the potential for atomic layer deposition compatibility. Even though these materials are not completely amorphous, their small crystal size and amorphous matrix can potentially reduce work function variation and improve their diffusion barrier property. These properties make CoTiN a good candidate as a gate material for future nanoelectronic devices and technology.

  17. Room temperature alcohol sensing by oxygen vacancy controlled TiO{sub 2} nanotube array

    SciTech Connect (OSTI)

    Hazra, A.; Dutta, K.; Bhowmik, B.; Bhattacharyya, P.; Chattopadhyay, P. P.

    2014-08-25

    Oxygen vacancy (OV) controlled TiO{sub 2} nanotubes, having diameters of 5070?nm and lengths of 200250?nm, were synthesized by electrochemical anodization in the mixed electrolyte comprising NH{sub 4}F and ethylene glycol with selective H{sub 2}O content. The structural evolution of TiO{sub 2} nanoforms has been studied by field emission scanning electron microscopy. Variation in the formation of OVs with the variation of the structure of TiO{sub 2} nanoforms has been evaluated by photoluminescence and X-ray photoelectron spectroscopy. The sensor characteristics were correlated to the variation of the amount of induced OVs in the nanotubes. The efficient room temperature sensing achieved by the control of OVs of TiO{sub 2} nanotube array has paved the way for developing fast responding alcohol sensor with corresponding response magnitude of 60.2%, 45.3%, and 36.5% towards methanol, ethanol, and 2-propanol, respectively.

  18. CriTi-CAL: A computer program for Critical Coiled Tubing Calculations

    SciTech Connect (OSTI)

    He, X.

    1995-12-31

    A computer software package for simulating coiled tubing operations has been developed at Rogaland Research. The software is named CriTiCAL, for Critical Coiled Tubing Calculations. It is a PC program running under Microsoft Windows. CriTi-CAL is designed for predicting force, stress, torque, lockup, circulation pressure losses and along-hole-depth corrections for coiled tubing workover and drilling operations. CriTi-CAL features an user-friendly interface, integrated work string and survey editors, flexible input units and output format, on-line documentation and extensive error trapping. CriTi-CAL was developed by using a combination of Visual Basic and C. Such an approach is an effective way to quickly develop high quality small to medium size software for the oil industry. The software is based on the results of intensive experimental and theoretical studies on buckling and post-buckling of coiled tubing at Rogaland Research. The software has been validated by full-scale test results and field data.

  19. Atomic and electronic structure of the ferroelectric BaTiO{sub 3}/Ge(001) interface

    SciTech Connect (OSTI)

    Fredrickson, Kurt D.; Ponath, Patrick; Posadas, Agham B.; Demkov, Alexander A.; McCartney, Martha R.; Smith, David J.; Aoki, Toshihiro

    2014-06-16

    In this study, we demonstrate the epitaxial growth of BaTiO{sub 3} on Ge(001) by molecular beam epitaxy using a thin Zintl template buffer layer. A combination of density functional theory, atomic-resolution electron microscopy and in situ photoemission spectroscopy is used to investigate the electronic properties and atomic structure of the BaTiO{sub 3}/Ge interface. Aberration-corrected scanning transmission electron micrographs reveal that the Ge(001) 2??1 surface reconstruction remains intact during the subsequent BaTiO{sub 3} growth, thereby enabling a choice to be made between several theoretically predicted interface structures. The measured valence band offset of 2.7?eV matches well with the theoretical value of 2.5?eV based on the model structure for an in-plane-polarized interface. The agreement between the calculated and measured band offsets, which are highly sensitive to the detailed atomic arrangement, indicates that the most likely BaTiO{sub 3}/Ge(001) interface structure has been identified.

  20. Complex catalytic behaviors of CuTiOx mixed-oxide during CO oxidation

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Kim, Hyun You; Liu, Ping

    2015-09-21

    Mixed metal oxides have attracted considerable attention in heterogeneous catalysis due to the unique stability, reactivity, and selectivity. Here, the activity and stability of the CuTiOx monolayer film supported on Cu(111), CuTiOx/Cu(111), during CO oxidation was explored using density functional theory (DFT). The unique structural frame of CuTiOx is able to stabilize and isolate a single Cu+ site on the terrace, which is previously proposed active for CO oxidation. Furthermore, it is not the case, where the reaction via both the Langmuir–Hinshelwood (LH) and the Mars-van Krevelen (M-vK) mechanisms are hindered on such single Cu+ site. Upon the formation ofmore » step-edges, the synergy among Cuδ+ sites, TiOx matrix, and Cu(111) is able to catalyze the reaction well. Depending on temperatures and partial pressure of CO and O2, the surface structure varies, which determines the dominant mechanism. In accordance with our results, the Cuδ+ ion alone does not work well for CO oxidation in the form of single sites, while the synergy among multiple active sites is necessary to facilitate the reaction.« less

  1. Pseudocapacitive Lithium-Ion Storage in Oriented Anatase TiO2 Nanotube Arrays

    SciTech Connect (OSTI)

    Zhu, K.; Wang, Q.; Kim, J. H.; Pesaran, A. A.; Frank, A. J.

    2012-06-07

    We report on the synthesis and electrochemical properties of oriented anatase TiO{sub 2} nanotube (NT) arrays as electrodes for Li-ion batteries. The TiO{sub 2} NT electrodes displayed both pseudocapacitive Li{sup +} storage associated with the NT surface and the Li{sup +} storage within the bulk material. The relative contribution of the pseudocapacitive and bulk storages depends strongly on the scan rate. While the charges are stored primarily in the bulk at low scan rates (<< 1 mV/s), the surface storage dominates the total storage capacity at higher scan rates (>1 mV/s). The storage capacity of the NT electrodes as a function of charge/discharge rates showed no dependence on the NT film thickness, suggesting that the Li{sup +} insertion/extraction processes occur homogeneously across the entire length of NT arrays. These results indicated that the electron conduction along the NT walls and the ion conduction within the electrolyte do not cause significant hindering of the charge/discharge kinetics for NT electrode architectures. As a result of the surface pseudocapacitive storage, the reversible Li{sup +} storage capacities for TiO{sub 2} NT electrodes were higher than the theoretical storage capacity for bulk anatase TiO{sub 2} materials.

  2. Metastable bcc phase formation in the Nb-Cr-Ti system

    SciTech Connect (OSTI)

    Thoma, D.J.; Perepezko, J.H.

    1994-08-01

    Metastable disordered bcc phases have been formed from the melt in the Nb-Cr-Ti system where primary Laves phases would develop under equilibrium solidification conditions. Three vertical temperature-composition sections in the ternary system incorporating NbCr, were evaluated: the Nb-Cr binary, the TiCr{sub 2}-NbCr{sub 2} isoplethal section, and the NbCr{sub 2}-Ti plethal section. In the rapid solidification of NbCr{sub 2}, metastable bcc phase formation was not observed, but deviations from NbCr{sub 2} stoichiometry or alloying with Ti was found to promote bcc phase formation by decreasing the required liquid undercooling to reach the metastable bcc liquidus and solidus. The metastable phases were characterized through x-ray diffraction (XRD), and systematic deviations from Vegard`s Rule have been defined in the three plethal sections. The metastable bcc phases decompose at temperatures >800{degrees}C to uniformly refined microstructures. As a result, novel microstructural tailoring schemes are possible through the metastable precursor microstructures.

  3. Preparation of atomically flat rutile TiO2(001) surfaces for oxide film growth

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Wang, Yang; Lee, Shinbuhm; Vilmercati, P.; Lee, Ho Nyung; Weitering, Hanno; Snijders, Paul C.

    2016-03-01

    The availability of low-index rutile TiO2 single crystal substrates with atomically flat surfaces is essential for enabling epitaxialgrowth of rutile transition metal oxide films. The high surface energy of the rutile (001) surface often leads to surface faceting, which precludes the sputter and annealing treatment commonly used for the preparation of clean and atomically flat TiO2(110) substrate surfaces. In this work, we reveal that stable and atomically flat rutile TiO2(001) surfaces can be prepared with an atomically ordered reconstructedsurface already during a furnace annealing treatment in air. We tentatively ascribe this result to the decrease in surface energy associated withmore » the surface reconstruction, which removes the driving force for faceting. Despite the narrow temperature window where this morphology can initially be formed, we demonstrate that it persists in homoepitaxialgrowth of TiO2(001) thin films. The stabilization of surface reconstructions that prevent faceting of high-surface-energy crystal faces may offer a promising avenue towards the realization of a wider range of high quality epitaxial transition metal oxide heterostructures.« less

  4. The Synthesis of Ag-Doped Mesoporous TiO2

    SciTech Connect (OSTI)

    Li, Xiaohong S.; Fryxell, Glen E.; Wang, Chong M.; Engelhard, Mark H.

    2008-04-15

    Ag-doped mesoporous titanium oxide was prepared using non-ionic surfactants and easily handled titanium precursors, under mild reaction conditions. In contrast to the stabilizing effect of Cd-doping on mesoporous TiO2, Ag-doping was found to significantly destabilize the mesoporous structure.

  5. Generation of Organic Radicals During Photocatalytic Reactions on TiO2

    SciTech Connect (OSTI)

    Henderson, Michael A.; Deskins, N. Aaron; Zehr, Robert T.; Dupuis, Michel

    2011-04-01

    Using a variety of organic carbonyl molecules (R1C(O)R2) and the rutile TiO2(110) surface as a model photocatalyst, we demonstrate both experimentally and theoretically that ejection of organic radicals from TiO2 surfaces is likely a prevalent reaction process occurring during heterogeneous photooxidationof organic molecules. Organic carbonyls react with coadsorbed oxygen species to form organic diolates which are more strongly bound to TiO2 than are the parent carbonyls. The parent carbonyls, when bound to TiO2(110) in an ?1 configuration, are photo-inactive. However, the diolates are shown to photodecompose by ejection one of the two R substituents from the surface into the gas phase, leaving behind the carboxylate of the other R group. Theoretical calculations using DFT show that in most cases the choice of which R group is ejected can be predicted based on the C-R bond energies and, to a lesser extent, the stability of the ejected R group.

  6. Isothermal oxidation behavior and microstructure of plasma surface Ta coating on ?-TiAl

    SciTech Connect (OSTI)

    Song, Jian; Zhang, Ping-Ze Wei, Dong-Bo; Wei, Xiang-Fei; Wang, Ya

    2014-12-15

    The oxidation behavior of ?-TiAl with Ta surface coating fabricated by double glow plasma surface alloying technology was investigated by thermogravimetric method. Oxidation experiments were carried out at 750 C and 850 C in air for 100 h. The modification layer was comprised of deposition layer and diffusion layer, which metallurgically adhered to the substrate. Tantalum element decreased with the case depth. The oxidation morphology was studied by a scanning electron microscope and X-ray diffraction. The results highlighted that in the oxidizing process of the oxidation, the phase containing Ta-richer may restrain diffusing outward of the element Al in the matrix. Ti diffused outward, and formed the TiO{sub 2} scales, while the middle layer was rich in Al, and formed the continuous Al{sub 2}O{sub 3} scales after oxidation, which was effective to prevent further infiltration of oxygen atoms, and as a result the oxidation resistance increased immensely. - Highlights: A Ta modified coating was prepared on ?-TiAl using DGP surface alloying technology. The modification layer metallurgically adhered to the substrate. The bonding force is about 60 N, satisfying the demands of practical use. The oxidation resistance increased immensely at 750 C and 850 C.

  7. Effects of pH and anion on hydrogen sorption/desorption at/within oxide-derived Pd electrodes

    SciTech Connect (OSTI)

    Hu, C.C.; Wen, T.C.

    1995-05-01

    A lot of interest in the electrochemical behavior of H and D sorption within/at palladium has been prompted by Fleischmann and Pons` reports which had claimed to observe that nuclear fusion was induced by electrochemical compression of deuterium within a palladium lattice, although there are some disputes of this work in the open literature. Oxide-derived Pd electrodes were obtained by cathodic polarization of Pd oxide-coated titanium electrodes (fabricated by thermal decomposition) at 0 V (RHE) for 30 min in 1.5 mol/dm{sup 3} NaOH. Hydrogen adsorption/absorption (denoted hereafter as sorption) and desorption within/at these electrodes were obtained using cyclic voltammetry (CV), chronopotentiometry, and linear sweep voltammetry (LSV). CV results revealed that {beta}-PdH formation/oxidation is more reversible in either concentrated acid or base solutions than in intermediate pH media and the rate of {beta}-PDH desorption is faster in a pH solution <10. The oxidation of {beta}-PDH is electron transfer controlled in intermediate pH media, especially in weakly basic solutions due to the adsorption of H{sub 2}PO{sub 4}{sup {minus}}/HPO{sub 4}{sup 2{minus}}. The sequence of anions with respect to increasing ability to inhibit hydrogen sorption is: CH{sub 3}COO{sup {minus}} < Cl{sup {minus}} < HSO{sub 4}{sup {minus}} {approx_equal} ClO{sub 4} < HC{sub 2}O{sub 4} < H{sub 2}PO{sub 4}.

  8. Microfluidic device having an immobilized pH gradient and PAGE gels for protein separation and analysis

    DOE Patents [OSTI]

    Sommer, Gregory J.; Hatch, Anson V.; Singh, Anup K.; Wang, Ying-Chih

    2012-12-11

    Disclosed is a novel microfluidic device enabling on-chip implementation of a two-dimensional separation methodology. Previously disclosed microscale immobilized pH gradients (IPG) are combined with perpendicular polyacrylamide gel electrophoresis (PAGE) microchannels to achieve orthogonal separations of biological samples. Device modifications enable inclusion of sodium dodecyl sulfate (SDS) in the second dimension. The device can be fabricated to use either continuous IPG gels, or the microscale isoelectric fractionation membranes we have also previously disclosed, for the first dimension. The invention represents the first all-gel two-dimensional separation microdevice, with significantly higher resolution power over existing devices.

  9. E&nr Ph. S. W.. Wahhgt~n. D.C. 200242174, TIkpbnc (202) 48a60uo

    Office of Legacy Management (LM)

    75' 00.955 L' E&nr Ph. S. W.. Wahhgt~n. D.C. 200242174, TIkpbnc (202) 48a60uo 7117-03.87.cdy.43 23 September 1987 CR CA.d M r. Andrew Wallo, III, NE-23 Division of Facility & Site Decoaunissioning Projects U.S. Department of Energy Germantown, Maryland 20545 Dear M r. Wallo: ELIMINATION RECOMMENDATION -- COLLEGES AND UNIVERSITIES M /4.0-03 kl 77.0% I - The attached elimination reconunendation was prepared in accordance rlL.0~ with your suggestion during our meeting on 22 September. The

  10. Paul J. Merges, PhD Director, Bureau of Radiation New York State Department of Environmental Conservation

    Office of Legacy Management (LM)

    AU62 & 1993 Paul J. Merges, PhD Director, Bureau of Radiation New York State Department of Environmental Conservation 50 Wolf Road Albany, New York 12233 1; Dear Dr. Merges: Your letter of August 13, 1993, requested information concerning the I Mt. Kisco, New York, site that was used for radium production by the former Canadian Radium and Uranium Company. This site was considered for the U.S. Department of Energy's Formerly Utilized Sites Remedial Action Program, and it was eliminated from

  11. The Path of Carbon in Photosynthesis XIII. pH Effects in C{sup 14}O{sub 2} Fixation by Scenedesmus

    DOE R&D Accomplishments [OSTI]

    Ouellet, C.; Benson, A. A.

    1951-10-23

    The rates of photosynthesis and dark fixation of C{sup 14}O{sub 2} in Scenedesmus have been compared in dilute phosphate buffers of 1.6 to 11.4 pH; determination of C{sup 14} incorporation into the various products shows enhancement of uptake in an acid medium into sucrose, polysaccharides, alanine and serine, in an alkaline medium into malic asparctic acids. kinetic experiments at extreme pH values suggest that several paths are available for CO{sub 2} assimilation. A tentative correlation of the results with the pH optima of some enzymes and resultant effects upon concentrations of intermediates is presented.

  12. Study of structure of the TiO{sub 2}MoO{sub 3} bilayer films by Raman spectroscopy

    SciTech Connect (OSTI)

    Santos, Elias de Barros; Sigoli, Fernando Aparecido; Mazali, Italo Odone

    2014-12-15

    Highlights: TiO{sub 2}MoO{sub 3} bilayer thin films were easily prepared by dip-coating technique. Ti and Mo metallo-organic compounds were used as source of its respective oxide. TiO{sub 2} in anatase phase and orthorhombic phase of ?-MoO{sub 3} were identified. The bilayer structure was investigated by Raman spectroscopy. - Abstract: In this work, TiO{sub 2}MoO{sub 3} films were easily prepared by dip-coating technique and metallo-organic decomposition process (MOD). Raman analyses indicate the formation of TiO{sub 2} in anatase phase and orthorhombic phase of ?-MoO{sub 3}. It was observed that the Raman bands intensities attributed to TiO{sub 2} and MoO{sub 3} oxides were dependent on the number of decompositiondeposition cycles (DDC). The different number of DDC generates films with different thicknesses and the Raman signal was sensitive to this variation. Raman analyses provided qualitative information about the bilayer structure of the bi-component TiO{sub 2}MoO{sub 3} films, which was confirmed by scanning electron microscopy. In this direction, the dip-coating technique and MOD process can be an efficient strategy to facile preparation of many samples to be used in applications.

  13. Physical properties and electronic structure of a new barium titanate suboxide Ba1+?Ti13-?O?? (? = 0.11)

    SciTech Connect (OSTI)

    Rotundu, Costel R.; Jiang, Shan; Deng, Xiaoyu; Qian, Yiting; Khan, Saeed; Hawthorn, David G.; Kotliar, Gabriel; Ni, Ni

    2015-04-01

    The structure, transport, thermodynamic properties, x-ray absorption spectra (XAS), and electronic structure of a new barium titanate suboxide, Ba1+?Ti13-?O?? (? = 0.11), are reported. It is a paramagnetic poor metal with hole carriers dominating the transport. Fermi liquid behavior appears at low temperature. The oxidization state of Ti obtained by the XAS is consistent with the metallic Ti? state. Local density approximation band structure calculations reveal the material is near the Van Hove singularity. The pseudogap behavior in the Ti-d band and the strong hybridization between the Ti-d and O-p orbitals reflect the characteristics of the building blocks of the Ti?? semi-cluster and the TiO? quasi-squares, respectively.

  14. Physical properties and electronic structure of a new barium titanate suboxide Ba{sub 1+?}Ti{sub 13??}O{sub 12} (? = 0.11)

    SciTech Connect (OSTI)

    Rotundu, Costel R.; Jiang, Shan; Ni, Ni; Deng, Xiaoyu; Kotliar, Gabriel; Qian, Yiting; Hawthorn, David G.; Khan, Saeed

    2015-04-01

    The structure, transport, thermodynamic properties, x-ray absorption spectra (XAS), and electronic structure of a new barium titanate suboxide, Ba{sub 1+?}Ti{sub 13??}O{sub 12} (? = 0.11), are reported. It is a paramagnetic poor metal with hole carriers dominating the transport. Fermi liquid behavior appears at low temperature. The oxidization state of Ti obtained by the XAS is consistent with the metallic Ti{sup 2+} state. Local density approximation band structure calculations reveal the material is near the Van Hove singularity. The pseudogap behavior in the Ti-d band and the strong hybridization between the Ti-d and O-p orbitals reflect the characteristics of the building blocks of the Ti{sub 13} semi-cluster and the TiO{sub 4} quasi-squares, respectively.

  15. Effects of Ti-Based Additives on the Hydrogen Storage Properties of a L i B H 4 / C a H 2 Destabilized System

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, Hongwei; Ibikunle, Adeola; Goudy, Andrew J.

    2010-01-01

    Tmore » he hydrogen storage properties of a destabilized LiBH 4 / CaH 2 system ball-milled with TiCl 3 , TiF 3 , and TiO 2 additives have been investigated. It is found that the system with TiCl 3 additive has a lower dehydrogenation temperature than the ones with other additives. Further study shows that a higher amount of TiCl 3 is more effective in reducing the desorption temperature of the LiBH 4 / CaH 2 system, since it leads to a lower activation energy of dehydrogenation. The activations energies for mixtures containing 4, 10, and 25 mol% of TiCl 3 are 141, 126, and 110 kJ/mol, respectively. However, the benefits of higher amounts of TiCl 3 are offset by a larger reduction in hydrogen capacity of the mixtures.« less

  16. Evolution of structure in Na{sub 0.5}Bi{sub 0.5}TiO{sub 3} single crystals

    Office of Scientific and Technical Information (OSTI)

    with BaTiO{sub 3} (Journal Article) | SciTech Connect Evolution of structure in Na{sub 0.5}Bi{sub 0.5}TiO{sub 3} single crystals with BaTiO{sub 3} Citation Details In-Document Search Title: Evolution of structure in Na{sub 0.5}Bi{sub 0.5}TiO{sub 3} single crystals with BaTiO{sub 3} The structural, dielectric, and piezoelectric properties of Na{sub 0.5}Bi{sub 0.5}TiO{sub 3}-x mol. %BaTiO{sub 3} (NBT-x%BT) crystals have been investigated. The dielectric and piezoelectric properties of NBT-x%BT

  17. Effects of Ti-Based Additives on the Hydrogen Storage Properties of aLiBH4/CaH2Destabilized System

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Yang, Hongwei; Ibikunle, Adeola; Goudy, Andrew J.

    2010-01-01

    The hydrogen storage properties of a destabilizedLiBH4/CaH2system ball-milled withTiCl3,TiF3, andTiO2additives have been investigated. It is found that the system withTiCl3additive has a lower dehydrogenation temperature than the ones with other additives. Further study shows that a higher amount ofTiCl3is more effective in reducing the desorption temperature of theLiBH4/CaH2system, since it leads to a lower activation energy of dehydrogenation. The activations energies for mixtures containing 4, 10, and 25?mol% ofTiCl3are 141, 126, and 110?kJ/mol, respectively. However, the benefits of higher amounts ofTiCl3are offset by a larger reduction in hydrogen capacity of the mixtures.

  18. Electronic and optical properties of TiCoSb under different pressures

    SciTech Connect (OSTI)

    Xu Bin; Zhang Jing; Liang Jianchu; Gao Guoying; Yi Lin

    2012-08-15

    The electronic structure and optical properties of TiCoSb are studied by the first-principles calculation. It is found that the band gaps increase with the pressure increasing. It is noted that the increase of the band gap is due to the electrons of Ti 3d and Co 3d of the valence band (VB) shifting away from the Fermi level. Our calculation indicates that TiCoSb has the large density of state near the Fermi level; moreover, the changes of the density of states near the Fermi level mainly are caused by Ti 3d and Co 3d under the different pressures. It is noted that the absorption edge increases with an increase of pressure. As pressure increases, the static dielectric constants {epsilon}{sub 1}(0) decrease. All peaks of the imaginary part of the dielectric function {epsilon}{sub 2}({omega}) move towards higher energies within increasing pressure. - Graphical abstract: The first peak positions of the absorption spectrum increase and shift the high energy with an increase of pressure. The buleshift of the absorption edge could be observed. Highlights: Black-Right-Pointing-Pointer It is noted that the increase of the band gap is due to the electrons of Ti 3d and Co 3d of VB moving away from the Fermi level. Black-Right-Pointing-Pointer It is noted that the absorption edge increases with an increase of pressure. Black-Right-Pointing-Pointer As pressure increases, the static dielectric constant {epsilon}{sub 1}(0) decreases. Black-Right-Pointing-Pointer All peaks of the imaginary part of the dielectric function {epsilon}{sub 2}({omega}) move to wards higher energies within creasing pressure.

  19. Microstructural study and densification analysis of hot work tool steel matrix composites reinforced with TiB{sub 2} particles

    SciTech Connect (OSTI)

    Fedrizzi, A.; Pellizzari, M.; Zadra, M.; Marin, E.

    2013-12-15

    Hot work tool steels are characterized by good toughness and high hot hardness but are less wear resistant than other tooling materials, such as high speed steel. Metal matrix composites show improved tribological behavior, but not much work has been done in the field of hot work tool steels. In this paper TiB{sub 2}-reinforced hot work tool steel matrix composites were produced by spark plasma sintering (SPS). Mechanical alloying (MA) was proposed as a suited process to improve the composite microstructure. Density measurements and microstructure confirmed that MA promotes sintering and produces a fine and homogeneous dispersion of reinforcing particles. X-ray diffraction patterns of the sintered composites highlighted the formation of equilibrium Fe{sub 2}B and TiC, as predicted by thermodynamic calculations using Thermo-Calc software. Scanning electron microscopy as well as scanning Kelvin probe force microscopy highlighted the reaction of the steel matrix with TiB{sub 2} particles, showing the formation of a reaction layer at the TiB{sub 2}-steel interface. Phase investigations pointed out that TiB{sub 2} is not chemically stable in steel matrix because of the presence of carbon even during short time SPS. - Highlights: TiB{sub 2} reinforced steel matrix composites were produced by spark plasma sintering. TiB{sub 2} was successfully dispersed in the steel matrix by mechanical alloying. Steel and TiB{sub 2} react during sintering forming equilibrium Fe{sub 2}B and TiC. The new phases were investigated by means of AFM, Volta potential and XRD analyses.

  20. Nanocrystalline SiC and Ti3SiC2 Alloys for Reactor Materials: Diffusion of Fission Product Surrogates

    SciTech Connect (OSTI)

    Henager, Charles H.; Jiang, Weilin

    2014-11-01

    MAX phases, such as titanium silicon carbide (Ti3SiC2), have a unique combination of both metallic and ceramic properties, which make them attractive for potential nuclear applications. Ti3SiC2 has been suggested in the literature as a possible fuel cladding material. Prior to the application, it is necessary to investigate diffusivities of fission products in the ternary compound at elevated temperatures. This study attempts to obtain relevant data and make an initial assessment for Ti3SiC2. Ion implantation was used to introduce fission product surrogates (Ag and Cs) and a noble metal (Au) in Ti3SiC2, SiC, and a dual-phase nanocomposite of Ti3SiC2/SiC synthesized at PNNL. Thermal annealing and in-situ Rutherford backscattering spectrometry (RBS) were employed to study the diffusivity of the various implanted species in the materials. In-situ RBS study of Ti3SiC2 implanted with Au ions at various temperatures was also performed. The experimental results indicate that the implanted Ag in SiC is immobile up to the highest temperature (1273 K) applied in this study; in contrast, significant out-diffusion of both Ag and Au in MAX phase Ti3SiC2 occurs during ion implantation at 873 K. Cs in Ti3SiC2 is found to diffuse during post-irradiation annealing at 973 K, and noticeable Cs release from the sample is observed. This study may suggest caution in using Ti3SiC2 as a fuel cladding material for advanced nuclear reactors operating at very high temperatures. Further studies of the related materials are recommended.

  1. Electronic structure of the SiN{sub x}/TiN interface: A model system for superhard nanocomposites

    SciTech Connect (OSTI)

    Patscheider, Joerg; Hellgren, Niklas; Haasch, Richard T.; Petrov, Ivan; Greene, J. E.

    2011-03-15

    Nanostructured materials such as nanocomposites and nanolaminates--subjects of intense interest in modern materials research--are defined by internal interfaces, the nature of which is generally unknown. Nevertheless, the interfaces often determine the bulk properties. An example of this is superhard nanocomposites with hardness approaching that of diamond. TiN/Si{sub 3}N{sub 4} nanocomposites (TiN nanocrystals encapsulated in a fully percolated SiN{sub x} tissue phase) and nanolaminates, in particular, have attracted much attention as model systems for the synthesis of such superhard materials. Here, we use in situ angle-resolved x-ray photoelectron spectroscopy to probe the electronic structure of Si{sub 3}N{sub 4}/TiN(001), Si/TiN(001), and Ti/TiN(001) bilayer interfaces, in which 4-ML-thick overlayers are grown in an ultrahigh vacuum system by reactive magnetron sputter deposition onto epitaxial TiN layers on MgO(001). The thickness of the Si{sub 3}N{sub 4}, Si, and Ti overlayers is chosen to be thin enough to insure sufficient electron transparency to probe the interfaces, while being close to values reported in typical nanocomposites and nanolaminates. The results show that these overlayer/TiN(001) interfaces have distinctly different bonding characteristics. Si{sub 3}N{sub 4} exhibits interface polarization through the formation of an interlayer, in which the N concentration is enhanced at higher substrate bias values during Si{sub 3}N{sub 4} deposition. The increased number of Ti-N bonds at the interface, together with the resulting polarization, strengthens interfacial bonding. In contrast, overlayers of Si and, even more so, metallic Ti weaken the interface by minimizing the valence band energy difference between the two phases. A model is proposed that provides a semiquantitative explanation of the interfacial bond strength in nitrogen-saturated and nitrogen-deficient Ti-Si-N nanocomposites.

  2. Electric field effects in graphene/LaAlO{sub 3}/SrTiO{sub 3}

    Office of Scientific and Technical Information (OSTI)

    heterostructures and nanostructures (Journal Article) | SciTech Connect Electric field effects in graphene/LaAlO{sub 3}/SrTiO{sub 3} heterostructures and nanostructures Citation Details In-Document Search Title: Electric field effects in graphene/LaAlO{sub 3}/SrTiO{sub 3} heterostructures and nanostructures We report the development and characterization of graphene/LaAlO{sub 3}/SrTiO{sub 3} heterostructures. Complex-oxide heterostructures are created by pulsed laser deposition and are

  3. TiO{sub 2}/PANI And MWNT/PANI Composites Thin Films For Hydrogen Gas Sensing

    SciTech Connect (OSTI)

    Srivastava, Subodh; Kumar, Sumit; Agrawal, Shweta; Saxena, Arpita; Choudhary, B. L.; Mathur, Shubhra; Singh, M.; Vijay, Y. K.

    2010-12-01

    The MWNT and TiO{sub 2} doped Polyaniline (PANI) composites were synthesized by In-situ chemical oxidative polymerization method at low temperature. The MWNT/PANI and TiO{sub 2}/PANI composite thin films were prepared using spin coating method onto finger type interdigited electrodes to develop the chemiresistor type gas sensor for hydrogen gas sensing application. It was observed that the MWNT and TiO{sub 2} doped PANI composite thin films show a higher response in comparision to neat PANI. The structural and morphological properties of these composite films were characterized by X-Ray differaction (XRD) pattern and sccaning electrone microscopy (SEM) respectively.

  4. Thermochemical generation of hydrogen and oxygen from water. [NaMnO/sub 2/ and TiO/sub 2/

    DOE Patents [OSTI]

    Robinson, P.R.; Bamberger, C.E.

    1980-02-08

    A thermochemical cyclic process for the production of hydrogen exploits the reaction between sodium manganate (NaMnO/sub 2/) and titanium dioxide (TiO/sub 2/) to form sodium titanate (Na/sub 2/TiO/sub 3/), manganese (II) titanate (MnTiO/sub 3/) and oxygen. The titanate mixture is treated with sodium hydroxide, in the presence of steam, to form sodium titanate, sodium manganate (III), water and hydrogen. The sodium titanate-manganate (III) mixture is treated with water to form sodium manganate (III), titanium dioxide and sodium hydroxide. Sodium manganate (III) and titanium dioxide are recycled following dissolution of sodium hydroxide in water.

  5. IMPROVED log(gf) VALUES FOR LINES OF Ti I AND ABUNDANCE DETERMINATIONS IN THE PHOTOSPHERES OF THE SUN AND METAL-POOR STAR HD 84937 (ACCURATE TRANSITION PROBABILITIES FOR Ti I)

    SciTech Connect (OSTI)

    Lawler, J. E.; Guzman, A.; Wood, M. P.; Sneden, C.; Cowan, J. J. E-mail: adrianaguzman2014@u.northwestern.edu E-mail: chris@verdi.as.utexas.edu

    2013-04-01

    New atomic transition probability measurements for 948 lines of Ti I are reported. Branching fractions from Fourier transform spectra and from spectra recorded using a 3 m echelle spectrometer are combined with published radiative lifetimes from laser-induced fluorescence measurements to determine these transition probabilities. Generally good agreement is found in comparisons to the NIST Atomic Spectra Database. The new Ti I data are applied to re-determine the Ti abundance in the photospheres of the Sun and metal-poor star HD 84937 using many lines covering a range of wavelength and excitation potential to explore possible non-local thermal equilibrium effects. The variation of relative Ti/Fe abundance with metallicity in metal-poor stars observed in earlier studies is supported in this study.

  6. Large area graphene ion sensitive field effect transistors with tantalum pentoxide sensing layers for pH measurement at the Nernstian limit

    SciTech Connect (OSTI)

    Fakih, Ibrahim, E-mail: ibrahim.fakih@mail.mcgill.ca; Sabri, Shadi; Szkopek, Thomas, E-mail: thomas.szkopek@mcgill.ca [Department of Electrical and Computer Engineering, McGill University, Montreal, Quebec H3A 2A7 (Canada); Mahvash, Farzaneh [Department of Electrical and Computer Engineering, McGill University, Montreal, Quebec H3A 2A7 (Canada); Dpartement de Chimie et Biochimie, Universite du Qubec Montral, Montreal, Quebec H3C 3P8 (Canada); Nannini, Matthieu [McGill Nanotools Microfab, McGill University, Montreal, Quebec H3A 2A7 (Canada); Siaj, Mohamed [Dpartement de Chimie et Biochimie, Universite du Qubec Montral, Montreal, Quebec H3C 3P8 (Canada)

    2014-08-25

    We have fabricated and characterized large area graphene ion sensitive field effect transistors (ISFETs) with tantalum pentoxide sensing layers and demonstrated pH sensitivities approaching the Nernstian limit. Low temperature atomic layer deposition was used to deposit tantalum pentoxide atop large area graphene ISFETs. The charge neutrality point of graphene, inferred from quantum capacitance or channel conductance, was used to monitor surface potential in the presence of an electrolyte with varying pH. Bare graphene ISFETs exhibit negligible response, while graphene ISFETs with tantalum pentoxide sensing layers show increased sensitivity reaching up to 55?mV/pH over pH 3 through pH 8. Applying the Bergveld model, which accounts for site binding and a Guoy-Chapman-Stern picture of the surface-electrolyte interface, the increased pH sensitivity can be attributed to an increased buffer capacity reaching up to 10{sup 14} sites/cm{sup 2}. ISFET response was found to be stable to better than 0.05 pH units over the course of two weeks.

  7. Activated RhoA Binds to the Pleckstrin Homology (PH) Domain of PDZ-RhoGEF, a Potential Site for Autoregulation

    SciTech Connect (OSTI)

    Chen, Zhe; Medina, Frank; Liu, Mu-ya; Thomas, Celestine; Sprang, Stephen R.; Sternweis, Paul C.

    2010-07-19

    Guanine nucleotide exchange factors (GEFs) catalyze exchange of GDP for GTP by stabilizing the nucleotide-free state of the small GTPases through their Dbl homology/pleckstrin homology (DH {center_dot} PH) domains. Unconventionally, PDZ-RhoGEF (PRG), a member of the RGS-RhoGEFs, binds tightly to both nucleotide-free and activated RhoA (RhoA {center_dot} GTP). We have characterized the interaction between PRG and activated RhoA and determined the structure of the PRG-DH {center_dot} PH-RhoA {center_dot} GTP{gamma}S (guanosine 5{prime}-O-[{gamma}-thio]triphosphate) complex. The interface bears striking similarity to a GTPase-effector interface and involves the switch regions in RhoA and a hydrophobic patch in PRG-PH that is conserved among all Lbc RhoGEFs. The two surfaces that bind activated and nucleotide-free RhoA on PRG-DH {center_dot} PH do not overlap, and a ternary complex of PRG-DH {center_dot} PH bound to both forms of RhoA can be isolated by size-exclusion chromatography. This novel interaction between activated RhoA and PH could play a key role in regulation of RhoGEF activity in vivo.

  8. Visible light activated photocatalytic behaviour of rare earth modified commercial TiO{sub 2}

    SciTech Connect (OSTI)

    Tobaldi, D.M.; Seabra, M.P.; Labrincha, J.A.

    2014-02-01

    Highlights: RE gave more surface hydroxyl groups attached to the photocatalyst's surface. RE gave the modified and fired samples a high specific surface area. Photocatalytic activity was assessed in gassolid phase under visible-light exposure. Thermal treated RE-TiO{sub 2}s showed a superior visible-light photocatalytic activity. La-TiO{sub 2} was the best performing photocatalyst. - Abstract: A commercial TiO{sub 2} nanopowder, Degussa P25, was modified with several rare earth (RE) elements in order to extend its photocatalytic activity into the visible range. The mixtures were prepared via solid-state reaction of the precursor oxides, and thermally treated at high temperature (900 and 1000 C), with the aim of investigating the photocatalytic activity of the thermally treated samples. This thermal treatment was chosen for a prospective application as a surface layer in materials that need to be processed at high temperatures. The photocatalytic activity (PCA) of the samples was assessed in gassolid phase monitoring the degradation of isopropanol (IPA) under visible-light irradiation. Results showed that the addition of the REs lanthanum, europium and yttrium to TiO{sub 2} greatly improved its photocatalytic activity, despite the thermal treatment, because of the presence of more surface hydroxyl groups attached to the photocatalyst's surface, together with a higher specific surface area (SSA) of the modified and thermally treated samples, with regard to the unmodified and thermally treated Degussa P25. The samples doped with La, Eu and Y all had excellent PCA under visible-light irradiation, even higher than the untreated Degussa P25 reference sample, despite their thermal treatment at 900 C, with lanthanum producing the best results (i.e. the La-, Eu- and Y-TiO{sub 2} samples, thermally treated at 900 C, had, respectively, a PCA equal to 26, 27 and 18 ppm h{sup ?1} in terms of acetone formation versus 15 ppm h{sup ?1} for the 900 C thermally treated Degussa P25). On the other hand, CeTiO{sub 2}s had no significant photocatalytic activity.

  9. Low Activation Joining of SiC/SiC Composites for Fusion Applications: Tape Casting TiC+Si Powders

    SciTech Connect (OSTI)

    Henager, Charles H.; Kurtz, Richard J.; Canfield, Nathan L.; Shin, Yongsoon; Luscher, Walter G.; Mansurov, Jirgal; Roosendaal, Timothy J.; Borlaug, Brennan A.

    2014-03-03

    This work discusses the latest developments in TiC + Si displacement reaction joining at PNNL based on new work to produce tape-cast powders for improved SiC-joints.

  10. Increased photocatalytic activity of TiO2 mesoporous microspheres from codoping with transition metals and nitrogen

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Mathis, John E.; Lieffers, Justin J.; Mitra, Chandrima; Reboredo, Fernando A.; Bi, Z.; Bridges, Craig A.; Kidder, Michelle K.; Paranthaman, Mariappan Parans

    2015-11-06

    The composition of anatase TiO2 was modified by codoping using combinations of a transition metal and nitrogen in order to increase its photocatalytic activity and extend it performance in the visible region of the electromagnetic spectrum. The transition metals (Mn, Co, Ni, Cu) were added during the hydrothermal preparation of mesoporous TiO2 particles, and the nitrogen was introduced by post-annealing in flowing ammonia gas at high temperature. The samples were analyzed by SEM, XRD, BET, inductively-coupled plasma spectroscopy, and diffuse reflectance UV-vis spectroscopy. The photocatalytic activity was assessed by observing the change in methylene blue concentrations under both UV-vis andmore » visible-only light irradiation. As a result, the photocatalytic activity of the (Mn,N), (Co,N), (Cu,N), and Ni,N) codoped TiO2 was significantly enhanced relative to (N) TiO2.« less

  11. Low Activation Joining of SiC/SiC Composites for Fusion Applications: Tape Casting TiC+Si Powders

    SciTech Connect (OSTI)

    Henager, Charles H.; Kurtz, Richard J.; Canfield, Nathan L.; Shin, Yongsoon; Luscher, Walter G.; Mansurov, Jirgal; Roosendaal, Timothy J.; Borlaug, Brennan A.

    2013-08-06

    The use of SiC composites in fusion environments likely requires joining of plates using reactive joining or brazing. One promising reactive joining method uses solid-state displacement reactions between Si and TiC to produce Ti3SiC2 + SiC. We continue to explore the processing envelope for this joint for the TITAN collaboration in order to produce optimal joints to undergo irradiation studies in HFIR. One noted feature of the joints produced using tape-calendared powders of TiC+Si has been the large void regions that have been apparently unavoidable. Although the produced joints are very strong, these voids are undesirable. In addition, the tapes that were made for this joining were produced about 20 years ago and were aging. Therefore, we embarked on an effort to produce some new tape cast powders of TiC and Si that could replace our aging tape calendared materials.

  12. Observation of Precipitation Evolution in Fe-Ni-Mn-Ti-Al Maraging Steel using Atom Probe Tomography

    SciTech Connect (OSTI)

    Pereloma, E. V.; Stohr, R A; Miller, Michael K; Ringer, S. P.

    2009-01-01

    We describe the full decomposition sequence in an Fe-Ni-Mn-Ti-Al maraging steel during isothermal annealing at 550 C. Following significant pre-precipitation clustering reactions within the supersaturated martensitic solid solution, (Ni,Fe){sub 3}Ti and (Ni,Fe){sub 3}(Al,Mn) precipitates eventually form after isothermal aging for {approx}60 seconds. The morphology of the (Ni,Fe){sub 3}Ti particles changes gradually during aging from predominantly plate-like to rod-like, and, importantly, Mn and Al were observed to segregate to these precipitate/matrix interfaces. The (Ni,Fe){sub 3}(Al,Mn) precipitates occurred at two main locations: uniformly within the matrix and at the periphery of the (Ni,Fe){sub 3}Ti particles. We relate this latter mode of precipitation to the Mn-Al segregation.

  13. Spin-dependent transport across Co/LaAlO{sub 3}/SrTiO{sub 3} heterojunctions

    SciTech Connect (OSTI)

    Swartz, Adrian G.; Harashima, Satoshi; Xie, Yanwu; Kim, Bongju; Hwang, Harold Y.; Lu, Di; Bell, Christopher; Hikita, Yasuyuki

    2014-07-21

    The conducting interface formed between LaAlO{sub 3} and SrTiO{sub 3} exhibits high electron mobility, tunable carrier densities, and is theoretically predicted to have long spin lifetimes. Thus, the LaAlO{sub 3}/SrTiO{sub 3} heterostructure is a promising system for the transportation of spin information. We have investigated spin-dependent transport across Co/LaAlO{sub 3}/SrTiO{sub 3} heterostructures using an all electrical three terminal geometry and observed Lorentzian magnetoresistance typically associated with Hanle spin dephasing. However, such a picture fails to explain all the experimentally observed behavior. Further, experiments with spin-unpolarized Au/LaAlO{sub 3}/SrTiO{sub 3} heterojunctions support an alternative scenario involving current modulation by spin-dependent transport through defect states in the LaAlO{sub 3} barrier.

  14. Crystal Structure and Thermodynamic Stability of Ba/Ti-Substituted Pollucites for Radioactive Cs/Ba Immobilization

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Xu, Hongwu; Chavez, Manuel E.; Mitchell, Jeremy N.; Garino, Terry J.; Schwarz, Haiqing L.; Rodriguez, Mark A.; Rademacher, David X.; Nenoff, Tina Maria

    2015-04-23

    An analogue of the mineral pollucite (CsAlSi2O6), CsTiSi2O6.5 has a potential host phase for radioactive Cs. However, as 137Cs and 135Cs transmute to 137Ba and 135Ba, respectively, through the beta decay, it is essential to study the structure and stability of this phase upon Cs → Ba substitution. In this work, two series of Ba/Ti-substituted samples, CsxBa(1-x)/2TiSi2O6.5 and CsxBa1-xTiSi2O7-0.5x, (x = 0.9 and 0.7), were synthesized by high-temperature crystallization from their respective precursors. Synchrotron X-ray diffraction and Rietveld analysis reveal that while CsxBa(1-x)/2TiSi2O6.5 samples are phase-pure, CsxBa1-xTiSi2O7-0.5x samples contain Cs3x/(2+x)Ba(1-x)/(2+x)TiSi2O6.5 pollucites (i.e., also two-Cs-to-one-Ba substitution) and a secondary phase, fresnoitemore » (Ba2TiSi2O8). Thus, the CsxBa1-xTiSi2O7-0.5x series is energetically less favorable than CsxBa(1-x)/2TiSi2O6.5. To study the stability systematics of CsxBa(1-x)/2TiSi2O6.5 pollucites, high-temperature calorimetric experiments were performed at 973 K with or without the lead borate solvent. Enthalpies of formation from the constituent oxides (and elements) have thus been derived. Our results show that with increasing Ba/(Cs + Ba) ratio, the thermodynamic stability of these phases decreases with respect to their component oxides. Hence, from the energetic viewpoint, continued Cs → Ba transmutation tends to destabilize the parent silicotitanate pollucite structure. However, the Ba-substituted pollucite co-forms with fresnoite (which incorporates the excess Ba), thereby providing viable ceramic waste forms for all the Ba decay products.« less

  15. TiO{sub 2}/N-graphene nanocomposite via a facile in-situ hydrothermal solgel strategy for visible light photodegradation of eosin Y

    SciTech Connect (OSTI)

    Liu, Yingliang; Pei, Fuyun Lu, Ruijuan; Xu, Shengang; Cao, Shaokui

    2014-12-15

    Highlights: TiO{sub 2}/N-graphene is synthesized via in-situ hydrothermal solgel strategy. TiO{sub 2} nanoparticles are chemically anchored on N-graphene nanosheets. The band gap of TiO{sub 2}/N-graphene is red-shifted from neat TiO{sub 2} nanoparticles. 5-NGT nanocomposite has the best visible light photodegradation performance. - Abstract: TiO{sub 2}/N-graphene nanocomposites are synthesized via a facile in-situ hydrothermal solgel strategy in order to improve the photocatalytic efficiency for pollutant photodegradation under visible light irradiation. The as-prepared nanocomposites are respectively characterized by transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD) and UVvis diffuse reflectance spectroscopy. Results indicated that neat TiO{sub 2} nanoparticles have an average diameter about 6.70 nm while TiO{sub 2} nanoparticles in TiO{sub 2}/N-graphene nanocomposites synthesized through in-situ hydrothermal solgel strategy bear an average diameter of ?1 nm and are anchored on N-graphene nanosheets via chemical bonding. Both neat TiO{sub 2} nanoparticles and chemically anchored TiO{sub 2} nanoparticles in TiO{sub 2}/N-graphene nanocomposites take on the crystal type of anatase. The band gap of TiO{sub 2}/N-graphene nanocomposites is red-shifted compared with neat TiO{sub 2} nanoparticles. The evaluation of photodegradation performance under visible light irradiation suggested that the nanocomposite with 5 wt% N-graphene content has the best visible light photodegradation performance.

  16. Production of coreshell type conducting FTO/TiO{sub 2} photoanode for dye sensitized solar cells

    SciTech Connect (OSTI)

    Icli, Kerem Cagatay; Yavuz, Halil Ibrahim; Ozenbas, Macit

    2014-02-15

    Coreshell type photoanode composed of electrically conducting fluorine doped tin dioxide (FTO) matrix and TiO{sub 2} shell layer was prepared and applied in dye sensitized solar cells. Effects of fluorine doping on tin dioxide based cells and precursor material on shell layer were investigated. Fluorine doped tin dioxide nanoparticles were synthesized under hydrothermal conditions and resistivity value down to 17 ? cm was achieved. Cells constructed from FTO nanoparticles show enhanced performance compared to intrinsic SnO{sub 2}. Deposition of thin blocking TiO{sub 2} layers was conducted using ammonium hexafluorotitanate and titanium tetrachloride aqueous solutions for different dipping durations which yielded significant deviations in the layer morphology and affected cell parameters. Best results were obtained with titanium tetrachloride treated cells giving 11.51 mA/cm{sup 2} photocurrent density and they were comparable with that of pure TiO{sub 2} based cells prepared under identical conditions. - Graphical abstract: Core shell type FTO matrix was formed as TiO{sub 2} is the shell material to create a blocking layer between FTO core and the electrolyte for suppressed recombination and efficiency enhancement. Display Omitted - Highlights: Coreshell type photoanode using conducting FTO matrix and TiO{sub 2} shell was prepared. FTO nanoparticles having resistivity value down to 17 ? cm was achieved. Best cell parameters were obtained with TiCl{sub 4} treated cells. FTO nanoparticle based cells show enhanced performance compared to intrinsic SnO{sub 2}. Photocurrent in TiCl{sub 4} treated cells is found as comparable to pure TiO{sub 2} cell.

  17. Thermodynamic Instability at the Stoichiometric LaAlO3/SrTiO3(001) Interface

    SciTech Connect (OSTI)

    Qiao, Liang; Droubay, Timothy C.; Shutthanandan, V.; Zhu, Zihua; Sushko, P. V.; Chambers, Scott A.

    2010-08-11

    Fully stoichiometric epitaxial LaAlO3 grown on the TiO2-terminated SrTiO3(001) by off-axis pulsed laser deposition is shown to exhibit strong La-Sr cation intermixing. This result is predicted by classical and quantum mechanical calculations of the relative stabilities of abrupt and intermixed states. The extensive cation intermixing has a marked impact on the electronic properties of the interface.

  18. Ammonia formation from NO reaction with surface hydroxyls on rutile TiO2 (110) - 11

    SciTech Connect (OSTI)

    Kim, Boseong; Kay, Bruce D.; Dohnalek, Zdenek; Kim, Yu Kwon

    2015-01-15

    The reaction of NO with hydroxylated rutile TiO2(110)-11 surface (h-TiO2) was investigated as a function of NO coverage using temperature-programmed desorption. Our results show that NO reaction with h-TiO2 leads to formation of NH3 which is observed to desorb at ~ 400 K. Interestingly, the amount of NH3 produced depends nonlinearly on the coverage of NO. The yield increases up to a saturation value of ~1.31013 NH3/cm2 at a NO dose of 51013 NO/cm2, but subsequently decreases at higher NO doses. Preadsorbed H2O is found to have a negligible effect on the NH3 desorption yield. Additionally, no NH3 is formed in the absence of surface hydroxyls (HObs) upon coadsorption of NO and H2O on a stoichiometric TiO2(110) (s-TiO2(110)). Based on these observations, we conclude that nitrogen from NO has a strong preference to react with HObs on the bridge-bonded oxygen rows (but not with H2O) to form NH3. The absolute NH3 yield is limited by competing reactions of HOb species with titanium-bound oxygen adatoms to form H2O. Our results provide new mechanistic insight about the interactions of NO with hydroxyl groups on TiO2(110) .

  19. One-step in situ synthesis of grapheneTiO{sub 2} nanorod hybrid composites with enhanced photocatalytic activity

    SciTech Connect (OSTI)

    Sun, Mingxuan Li, Weibin; Sun, Shanfu; He, Jia; Zhang, Qiang; Shi, Yuying

    2015-01-15

    Chemically bonded graphene/TiO{sub 2} nanorod hybrid composites with superior dispersity were synthesized by a one-step in situ hydrothermal method using graphene oxide (GO) and TiO{sub 2} (P25) as the starting materials. The as-prepared samples were characterized by XRD, XPS, TEM, FE-SEM, EDX, Raman, N{sub 2} adsorption, and UVvis DRS techniques. Enhanced light absorption and a red shift of absorption edge were observed for the composites in the ultravioletvisible diffuse reflectance spectroscopy (UVvis DRS). Their effective photocatalytic activity was evaluated by the photodegradation of methylene blue under visible light irradiation. An enhancement of photocatalytic performance was observed over graphene/TiO{sub 2} nanorod hybrid composite photocatalysts, as 3.7 times larger than that of pristine TiO{sub 2} nanorods. This work demonstrated that the synthesis of TiO{sub 2} nanorods and simultaneous conversion of GO to graphene without using reducing agents had shown to be a rapid, direct and clean approach to fabricate chemically bonded graphene/TiO{sub 2} nanorod hybrid composites with enhanced photocatalytic performance.

  20. Growth and self-assembly of BaTiO{sub 3} nanocubes for resistive switching memory cells

    SciTech Connect (OSTI)

    Chu, Dewei, E-mail: D.Chu@unsw.edu.au [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Lin, Xi; Younis, Adnan [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia); Li, Chang Ming [Chongqing Key Lab for Advanced Materials and Clean Energies of Techonologies Dean, Institute for Clean Energy and Advanced Materials, Southwest University, Chongqing (China); Dang, Feng [Research Center for Materials Back Casting Technology (MBT Center), Nagoya University, Nagoya 464-8603 (Japan); Li, Sean [School of Materials Science and Engineering, University of New South Wales, Sydney, 2052 NSW (Australia)

    2014-06-01

    In this work, the self-assembled BaTiO{sub 3} nanocubes based resistive switching memory capacitors are fabricated with hydrothermal and drop-coating approaches. The device exhibits excellent bipolar resistance switching characteristics with ON/OFF ratio of 5870, better reliability and stability over various polycrystalline BaTiO{sub 3} nanostructures. It is believed that the inter cube junctions is responsible for such a switching behaviour and it can be described by the filament model. The effect of film thickness on switching ratio (ON/OFF) was also investigated in details. - Graphical abstract: This work describes a novel resistive switching memory cell based on self-assembled BaTiO{sub 3} nanocubes. - Highlights: BaTiO{sub 3} nanocubes were prepared by one step facile hydrothermal method. Self-assembled BaTiO{sub 3} nanocubes thin films were obtained by drop-coating approach. The BaTiO{sub 3} nanocubes show excellent resistive switching properties for memory applications.

  1. Electrochemically synthesized ordered TiO2 and platinum nanocomposite electrode: preparation, characterization, and application to photoelectrocatalytic methanol oxidation

    SciTech Connect (OSTI)

    Li, Zhizhou; Cui, Xiaoli; Lin, Yuehe

    2009-04-01

    In this work, the nanocomposite electrodes consisting of Pt and TiO2 nanotubular arrays have been synthesized, and the morphologies, structural, and photo-electrochemical properties of the electrodes are characterized by SEM, XRD, and electrochemical methods. Highly ordered TiO2 nanotubular arrays can be obtained through anodization of titanium. The platinum nanoparticles are electrodeposited into TiO2 nanotubes by a chronopotentiometry method. Cyclic voltammetry and XRD measurements can confirm the presence of platinum in this nanocomposite electrode. The nanostructural electrode greatly improved performances for methanol oxidation under UV-Vis illumination compared to that without illumination. An enhancement of 58% in the current density has been observed upon illumination with UV-Vis light irradiance at an intensity of 50 mW/cm2. The improved performance of the TiO2/Pt nanocomposite electrode results from a enhanced methanol oxidation by photo-generated holes in the TiO2 nanoarrays under illumination and a synergistic effectiveness between TiO2 and Pt nanoparticles.

  2. Photocatalytic degradation of methyl orange dye in water solutions in the presence of MWCNT/TiO{sub 2} composites

    SciTech Connect (OSTI)

    Da Dalt, S.; Alves, A.K.; Bergmann, C.P.

    2013-05-15

    Highlights: ? MWCNTs/TiO{sub 2} composites were obtained to degrade organic dyes in water. ? MWCNT/TiO{sub 2} composites were analyzed by photocatalysis and structural characterization. ? The photocatalytic shows efficient method for the degradation of dyes from aqueous effluents. - Abstract: The textile and dyestuff industries are the primary sources of the release of synthetic dyes into the environment and usually there are major pollutants in dye wastewaters. Because of their toxicity and slow degradation, these dyes are categorized as environmentally hazardous materials. In this context, carbon nanotubes/TiO{sub 2} (CNTs/TiO{sub 2}) composites were prepared using multi-walled CNTs (MWCNTs), titanium (IV) propoxide and commercial TiO{sub 2} (P25{sup }) as titanium oxide sources, to degrade the methyl orange dye in solution through photocatalyst activity using UV irradiation. The composites were prepared by solution processing followed by thermal treatment at 400, 500 and 600 C. The heterojunction between nanotubes and TiO{sub 2} was confirmed by XRD, specific surface area. The coating morphology was observed with SEM and TEM.

  3. Ab-initio study of hydrogen doping and oxygen vacancy at anatase TiO{sub 2} surface

    SciTech Connect (OSTI)

    Sotoudeh, M.; Mohammadizadeh, M. R.; Hashemifar, S. J.; Abbasnejad, M.

    2014-02-15

    Density functionalpseudopotential calculations were performed to study the effects of hydrogen doping and oxygen vacancy, both individually and together, on the electronic structure and stability of (001) surface of TiO{sub 2} in the anatase phase. Based on our calculations, O/Ti termination is the most stable one, and it appears that p-states of deep and surface O atoms and d-orbitals of surface Ti atoms have roles in the valence band and, the conduction band comes from the d-orbitals of deep Ti atoms. Although, no considerable change was seen during H doping, a mid-gap state appeared below the conduction band in the O vacancy configuration. In the framework of ab-initio atomistic thermodynamics, we argue that the anatase TiO{sub 2} prefers a defected O layer termination in the [001] direction. The obtained electronic structures indicate that H doping in the bulk creates the empty mid-gap state below the conduction band and hence decreases the band gap of the system. This phenomenon may explain the enhanced photocatalytic activity of the anatase TiO{sub 2} (001) surface after hydrogenation.

  4. Solubility Measurements of Crystalline NiO in Aqueous Solution as a Function of Temperature and pH

    SciTech Connect (OSTI)

    Palmer, Donald; Benezeth, Pascale; Xiao, Caibin {nmn}; Wesolowski, David J; Anovitz, Lawrence {Larry} M

    2011-01-01

    Abstract Results of solubility experiments involving crystalline nickel oxide (bunsenite) in aqueous solutions are reported as functions of temperature (0 to 350 C) and pH at pressures slightly exceeding (with one exception) saturation vapor pressure. These experiments were carried out in either flow-through reactors or a hydrogen-electrode concentration cell for mildly acidic to near neutral pH solutions. The results were treated successfully with a thermodynamic model incorporating only the unhydrolyzed aqueous nickel species (viz., Ni2+ ) and the neutrally charged hydrolyzed species (viz., Ni(OH)02 ). The thermodynamic quantities obtained at 25 C and infinite dilution are, with 2 uncertainties: log10Ko s0 = (12.40 0.29), rGo m = (70.8 1.7) kJ mol 1; rHo m = (105.6 1.3) kJ mol 1; rSo m = (116.6 3.2) J K 1 mol 1; rCo p,m = (0 13) J K 1 mol 1; and log10Ko s2 = (8.76 0.15); rGo m = (50.0 1.7) kJ mol 1; rHo m = (17.7 1.7) kJ mol 1; rSo m = (108 7) J K 1 mol 1; rCo p,m = (108 3) J K 1 mol 1. These results are internally consistent, but the latter set differs from those gleaned from previous studies recorded in the literature. The corresponding thermodynamic quantities for the formation of Ni2+ and Ni(OH)02 are also estimated. Moreover, the Ni(OH) 3 anion was never observed, even in relatively strong basic solutions (mOH = 0.1 mol kg 1), contrary to the conclusions drawn from all but one previous study.

  5. Oxygen vacancies at the surface of SrTiO{sub 3} thin films

    SciTech Connect (OSTI)

    Silva, Alexandre R.; Dalpian, Gustavo M.

    2014-01-21

    The two-dimensional electron gas (2DEG) observed at the surface of oxide thin films and at the interface between two oxides has been widely discussed, but the mechanism responsible for this behavior is still not well understood. In this work, we study the properties of the SrTiO{sub 3} (001) surface and show that defects are necessary in order to explain this 2DEG. We study the properties of oxygen vacancies at the TiO{sub 2} and SrO terminated surface, and conclude they can explain the metallic behavior experimentally observed. There is a strong tendency for these vacancies to be localized at the surface, where the formation energy is less than 2.92?eV.

  6. A Low Hysteresis NiTiFe Shape Memory Alloy Based Thermal Conduction Switch

    SciTech Connect (OSTI)

    Lemanski, J. L.; Krishnan, V. B.; Manjeri, R. Mahadevan; Vaidyanathan, R.; Notardonato, W. U.

    2006-03-31

    Shape memory alloys possess the ability to return to a preset shape by undergoing a solid state phase transformation at a particular temperature. This work reports on the development and testing of a low temperature thermal conduction switch that incorporates a NiTiFe shape memory element for actuation. The switch was developed to provide a variable conductive pathway between liquid methane and liquid oxygen dewars in order to passively regulate the temperature of methane. The shape memory element in the switch undergoes a rhombohedral or R-phase transformation that is associated with a small hysteresis (typically 1-2 deg. C) and offers the advantage of precision control over a set temperature range. For the NiTiFe alloy used, its thermomechanical processing, subsequent characterization using dilatometry, differential scanning calorimetry and implementation in the conduction switch configuration are addressed.

  7. Dielectric relaxation and conduction in SrTiO{sub 3} thin films under dc bias

    SciTech Connect (OSTI)

    Ang, Chen; Yu, Zhi; Cross, L. E.; Guo, Ruyan; Bhalla, A. S.

    2001-08-06

    The dielectric and conduction behavior of SrTiO{sub 3} thin films deposited on a SrTiO{sub 3} single-crystal substrate is studied. Without dc bias, an obvious dielectric 'defect mode' in the dielectric loss is observed in the temperature range of {approx}100--200 K; however, no noticeable corresponding dielectric constant peak is observed. By applying a high dc bias ({>=}40 kV/cm), a dielectric constant peak with frequency dispersion appears in the same temperature range, the dielectric loss is increased, and simultaneously high dc conduction is observed. The induced dielectric constant peak is related to dc conduction and attributed to the coupling effect of the mobile carriers with the dielectric defect mode. {copyright} 2001 American Institute of Physics.

  8. Enhanced photocatalytic activity of Ag microgrid connected TiO{sub 2} nanocrystalline films

    SciTech Connect (OSTI)

    Pan Feng; Zhang Junying; Zhang Weiwei; Wang Tianmin; Cai Chao

    2007-03-19

    One reason for the high degree of photogenerated carrier recombination was found to be the charge accumulation caused by the uneven reaction area on the photocatalyst surface. The authors connected TiO{sub 2} nanoparticles with conducting Ag microgrid. Obvious photocatalytic activity improvement (81%) over the pure TiO{sub 2} was observed, which is attributed to the electron-hole pairs separation by the metal-semiconductor contact and the large specific area of metal grid, which increased the O{sub 2} absorption and transported the electrons to the sites needed for the deoxidize reactions. This structure lowers the electron accumulation on the particles and improves the utilization ratio of the photoexcited carriers.

  9. Aggregated TiO2 Based Nanotubes for Dye Sensitized Solar Cells

    SciTech Connect (OSTI)

    Nie, Zimin; Zhou, Xiaoyuan; Zhang, Qifeng; Cao, Guozhong; Liu, Jun

    2013-11-01

    One-dimensional (1D) semiconducting oxides have attracted great attention for dye sensitized solar cells (DSCs), but the overall performance is still quite limited as compared to TiO2 nanocrystalline DSCs. Here, we report the synthesis of aggregated TiO2 based nanotubes with controlled morphologies and crystalline structures to obtain an overall power conversion efficiency of 9.9% using conventional dye without any additional chemical treatment steps. The high efficiency is attributed to the unique aggregate structure for light harvesting, optimized high surface area, and good crystallinity of the nanotube aggregates obtained through proper thermal annealing. This study demonstrates that high efficiency DSCs can be obtained with 1D nanomaterials, and provides lessons on the importance of optimizing both the nanocrystalline structure and the overall microscale morphology.

  10. Applications of Tunable TiO2 Nanotubes as Nanotemplate and Photovoltaic Device

    SciTech Connect (OSTI)

    Li, Dongdong; Chang, Pai-Chun; Chien, Chung-Jen; Lu, Jia Grace

    2010-10-26

    Highly ordered anodic titanium oxide (ATO) TiO{sub 2} nanotube film has been synthesized via a typical two-step anodization method. Following a reductive doping approach, metallic materials (copper and nickel) can be efficiently electrodeposited into the nanotubes. This versatile process yields reproducible tubular structures in ATO membranes, because of the conductive nature of crystallized TiO{sub 2}, yielding promising potential for nanotemplate applications. In this paper, we present a dye-sensitized solar cell constructed by employing such ATO films. It is observed that the reductive doping treatment can also enhance the solar cells short current density and fill factor, resulting in an improved energy conversion efficiency.

  11. Visible Light Photocatalysis via CdS/ TiO 2 Nanocomposite Materials

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Srinivasan, Sesha S.; Wade, Jeremy; Stefanakos, Elias K.

    2006-01-01

    Nmore » anostructured colloidal semiconductors with heterogeneous photocatalytic behavior have drawn considerable attention over the past few years. This is due to their large surface area, high redox potential of the photogenerated charge carriers, and selective reduction/oxidation of different classes of organic compounds. In the present paper, we have carried out a systematic synthesis of nanostructured CdS- TiO 2 via reverse micelle process. The structural and microstructural characterizations of the as-prepared CdS- TiO 2 nanocomposites are determined using XRD and SEM-EDS techniques. The visible light assisted photocatalytic performance is monitored by means of degradation of phenol in water suspension.« less

  12. XAFS Study on TiO2 Photocatalyst Loaded on Zeolite Synthesized from Steel Slag

    SciTech Connect (OSTI)

    Kuwahara, Yasutaka; Ohmichi, Tetsutaro; Mori, Kosuke; Katayama, Iwao; Yamashita, Hiromi

    2007-02-02

    The convenient route for the synthesis of Y-zeolites by utilizing steel slag as a material source was developed. Through hydrothermal treatment, well-crystallized Y-zeolite was obtained. We also synthesized TiO2-loaded Y-zeolites by an impregnation method. The structure of titanium oxide species highly dispersed on the zeolite, which couldn't be detected by XRD patterns, was investigated by XAFS analysis. Photocatalytic activity for decomposition of 2-propanol in liquid phase was found to be enhanced by the hydrophobic surface property of zeolite. It has been demonstrated that the zeolite synthesized from steel slag would be applicable as a promising support of TiO2 photocatalyst.

  13. Diffusion of CO{sub 2} on Rutile TiO{sub 2}(110) Surface

    SciTech Connect (OSTI)

    Lee, Junseok; Sorescu, Dan C.; Deng, Xingyi; Jordan, Kenneth D.

    2011-12-15

    The diffusion of CO{sub 2} molecules on a reduced rutile TiO{sub 2}(110)-(11) surface has been investigated using scanning tunneling microscopy (STM) and density functional theory (DFT) calculations. The STM feature associated with a CO{sub 2} molecule at an oxygen vacancy (V{sub O}) becomes increasingly streaky with increasing temperature, indicating thermally activated CO{sub 2} diffusion from the V{sub O} site. From temperature-dependent tunneling current measurements, the barrier for diffusion of CO{sub 2} from the V{sub O} site is estimated to be 3.31 0.23 kcal/mol. The corresponding value from the DFT calculations is 3.80 kcal/mol. In addition, the DFT calculations give a barrier for diffusion of CO{sub 2} along Ti rows of only 1.33 kcal/mol.

  14. Voltage-dependent resistance of undoped rutile, TiO{sub 2}, ceramics

    SciTech Connect (OSTI)

    Liu, Yang; West, Anthony R.

    2013-12-23

    Lightly reduced rutile ceramics are n-type semiconductors whose resistance increases reversibly by 12 orders of magnitude, depending on temperature, on application of a small dc bias of 10100?V cm{sup ?1}. A similar effect is seen on changing the oxygen partial pressure surrounding the sample during impedance measurements and the bias dependence is attributed to changes in the equilibria between various ionised oxygen species adsorbed on sample surfaces, leading to changes in the mobile electron concentration in the sample bulk. The increase in resistance of n-type TiO{sub 2} with dc bias mirrors the decrease in resistance seen with p-type semiconductors such as acceptor-doped BaTiO{sub 3} and represents an effect, which has certain memristive characteristics but also significant differences.

  15. Composition, morphology and mechanical properties of sputtered TiAlN coating

    SciTech Connect (OSTI)

    Budi, Esmar; Razali, M. Mohd.; Nizam, A. R. Md.

    2014-03-24

    TiAlN coating was deposited on the tungsten carbide cutting tool by using DC magnetron sputtering system to study the influence of substrate bias and nitrogen flow rate on the composition, morphology and mechanical properties. The negatively substrate bias and nitrogen flow rate was varied from about ?79 to ?221 V and 30 sccm to 72 sccm, respectively. The coating composition and roughness were characterized by using SEM/EDX and Atomic Force Microscopy (AFM), respectively. The dynamic ultra micro hardness tester was used to measure the mechanical properties. The coating hardness increases to about 10-12 GPa with an increase of the negatively substrate bias up to ? 200 V and it tend to decrease with an increase in nitrogen flow rate up to 70 sccm. The increase of hardness follows the increase of Ti and N content and rms coating roughness.

  16. Environmental effect on room-temperature ductility of isothermally forged TiAl-base alloys

    SciTech Connect (OSTI)

    Nakamura, Morihiko; Hashimoto, Kenki (National Research Inst. for Metals, Tokyo (Japan)); Itoh, Naoyuki (Nippon Steel Corp., Chiba (Japan)); Tsujimoto, Tokuzo (Ibaraki Univ. (Japan). Faculty of Engineering); Suzuki, Toshiyuki (Kougakuin Univ., Tokyo (Japan))

    1994-02-01

    Isothermally forged TiAl-base alloy (Al-rich, Mn-containing, and Cr-containing TiAl) were heat-treated in various conditions, and equiaxed grain structures consisting of [gamma] and [alpha][sub 2] or [beta] phases were obtained. The heat-treated alloys were tensile tested in vacuum and air at room temperature, and the environmental effect on tensile elongation was studied. The ductility of the alloys consisting of equiaxed [gamma] grains and a large amount of [alpha][sub 2] grains was not largely affecting by laboratory air, and a decrease in the amount of [alpha][sub 2] grains resulted in a large reduction of ductility in air. The [beta] phase in the Cr-containing alloy improved the ductility in vacuum, but it resulted in a large reduction of ductility in air.

  17. Synthesis of mesoporous NiO doped TiO{sub 2} submicrosphere via spray hydrolysis

    SciTech Connect (OSTI)

    Bahadur, J.; Sen, D.; Prakash, J.; Singh, Ripandeep; Paul, B.; Mazumder, S.; Sathiyamoorthy, D.

    2012-06-05

    NiO doped TiO{sub 2} submicrosphere have been prepared via spray hydrolysis. The doping concentration has been varied form 2 wt% to 15 wt%. Morphology of the submicrospheres has been investigated using small-angle neutron scattering and scanning electron microscopy. Elemental analysis has been carried out by energy dispersive X-ray analysis which confirms the doping concentrations. The mesopores in submicrospheres possess cylindrical morphology.

  18. X-ray diffraction study of the phase transformations in NiTi shape memory alloy

    SciTech Connect (OSTI)

    Uchil, J.; Fernandes, F.M. Braz . E-mail: kkmahesh@rediffmail.com

    2007-03-15

    The phase transformations occurring in heat-treated NiTi shape memory alloys have been studied through the analysis of variation in integrated peak area (integrated intensity) with temperature, under the XRD peak profiles in the transformation temperature range. For this purpose, integrated peak area under the prominent peak corresponding to (110) plane of the austenitic phase has been chosen. The results so obtained are compared with those got from the DSC method. The XRD method is found to be more sensitive.

  19. Martensitic transformation behaviors of rapidly solidified TiNiMo powders

    SciTech Connect (OSTI)

    Kim, Yeon-wook

    2012-10-15

    For the fabrication of bulk near-net-shape shape memory alloys and porous metallic biomaterials, consolidation of TiNiMo alloy powders is more useful than that of elemental powders of Ti, Ni and Mo. Ti{sub 50}Ni{sub 49.9}Mo{sub 0.1} shape memory alloy powders were prepared by gas atomization, and transformation temperatures and microstructures of those powders were investigated as a function of powder size. XRD analysis showed that the B2RB19 martensitic transformation occurred in powders smaller than 150 ?m. According to DSC analysis of the as-atomized powders, the B2R transformation temperature (T{sub R}) of the 2550 ?m powders was 18.4 C. The T{sub R} decreased with increasing powder size, however, the difference in T{sub R} between 2550 ?m powders and 100150 ?m powders is only 1 C. Evaluation of powder microstructures was based on SEM examination of the surface and the polished and etched powder cross sections and the typical images of the rapidly solidified powders showed cellular morphology. Porous cylindrical foams of 10 mm diameter and 1.5 mm length were fabricated by spark plasma sintering (SPS) at 800 C and 5 MPa. Finally these porous TiNi alloy samples are heat-treated for 1 h at 850 C, and then quenched in ice water. The bulk samples have 23% porosity and 4.6 g/cm{sup 3} density and their T{sub R} is 17.8 C.

  20. Importance of Diffusion in Methanol Photochemistry on TiO2(110)

    SciTech Connect (OSTI)

    Shen, Mingmin; Acharya, Danda P.; Dohnalek, Zdenek; Henderson, Michael A.

    2012-12-06

    The photoactivity of methanol on the rutile TiO2(110) surface is shown to depend on the ability of methanol to diffuse on the surface and find sites active for its thermal dissociation to methoxy. Temperature programmed desorption (TPD) results show that the extent of methanol photodecomposition to formaldehyde is negligible on the clean TiO2(110) surface at 100 K due to a scarcity of sites that can convert (photoinactive) methanol to (photoactive) methoxy. The extent of photoactivity at 100 K significantly increases when methanol is coadsorbed with oxygen, however only those molecules able to adsorb near (next to) a coadsorbed oxygen species are active. Preannealing coadsorbed methanol and oxygen to above 200 K prior to UV irradiation results in a significant increase in photoactivity. Scanning tunneling microscopy (STM) images clearly show that the advent of increased photoactivity in TPD correlates with the onset of methanol diffusion along the surfaces Ti4+ rows at ~200 K. These results demonstrate that optimizing thermal processes (such as diffusion or proton transfer reactions) can be critical to maximizing photocatalytic reactivity on TiO2 surfaces. This work was supported by the US Department of Energy, Office of Basic Energy Sciences, Division of Chemical Sciences, Geosciences & Biosciences. Pacific Northwest National Laboratory (PNNL) is a multiprogram national laboratory operated for DOE by Battelle under contract DEAC05-76RL01830. The research was performed using EMSL, a national scientific user facility sponsored by the Department of Energy's Office of Biological and Environmental Research and located at Pacific Northwest National Laboratory.

  1. U.S. Department of Energy TP/TI Date PROPERTY

    Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

    01-95) U.S. Department of Energy TP/TI Date PROPERTY TRANSFER or TURN-IN From LOCATION Property Tag No. Stock No. Description of Articles Serial No. Qty. Unit Price Age and Condition ORIGINAL; COPY 1 - TRANSFEREE; COPY 2 - PROPERTY ACCOUNTABLE OFFICER; COPY 3 - TRANSFEROR Date recorded: Signature (Transferor) ACCOUNTABLE PROPERTY REPRESENTATIVE (PROPERTY SECTION) Date shipped Date received Signature (Transferee) ACCOUNTABLE PROPERTY REPRESENTATIVE TRANSFER APPROVED: PROPERTY ACCOUNTABLE OFFICER

  2. Bio-corrosion and cytotoxicity studies on novel Zr55Co30Ti15 and Cu60Zr20Ti20 metallic glasses

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Vincent, S.; Daiwile, A.; Devi, S. S.; Kramer, M. J.; Besser, M. F.; Murty, B. S.; Bhatt, Jatin

    2014-09-26

    Metallic glasses are a potential and compatible implant candidate for biomedical applications. In the present investigation, a comparative study between novel Zr55Co30Ti15 and Cu60Zr20Ti20 metallic glasses is carried out to evaluate in vitro biocompatibility using simulated body fluids. The bio-corrosion behavior of Zr- and Cu-based metallic glasses in different types of artificial body fluids such as artificial saliva solution, phosphate-buffered saline solution, artificial blood plasma solution, and Hank’s balanced saline solution is evaluated using potentiodynamic polarization studies at a constant body temperature of 310.15 K (37 °C). Surface morphology of samples after bio-corrosion experiments was observed by scanning electron microscopy.more » In vitro cytotoxicity test on glassy alloys were performed using human osteosarcoma cell line as per 10993-5 guidelines from International Organization for Standardization. As a result, the comparative study between Zr- and Cu-based glassy alloys provides vital information about the effect of elemental composition on biocompatibility of metallic glasses.« less

  3. Epitaxial c-axis oriented BaTiO{sub 3} thin films on SrTiO{sub 3}-buffered Si(001) by atomic layer deposition

    SciTech Connect (OSTI)

    Ngo, Thong Q.; McDaniel, Martin D.; Ekerdt, John G., E-mail: ekerdt@che.utexas.edu [Department of Chemical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Posadas, Agham B.; Demkov, Alexander A. [Department of Physics, The University of Texas at Austin, Austin, Texas 78712 (United States); Hu, Chengqing; Yu, Edward T. [Department of Electrical Engineering, The University of Texas at Austin, Austin, Texas 78712 (United States); Bruley, John [IBM Research Division, Yorktown Heights, New York 10593 (United States)

    2014-02-24

    Atomic layer deposition (ALD) of epitaxial c-axis oriented BaTiO{sub 3} (BTO) on Si(001) using a thin (1.6?nm) buffer layer of SrTiO{sub 3} (STO) grown by molecular beam epitaxy is reported. The ALD growth of crystalline BTO films at 225??C used barium bis(triisopropylcyclopentadienyl), titanium tetraisopropoxide, and water as co-reactants. X-ray diffraction (XRD) reveals a high degree of crystallinity and c-axis orientation of as-deposited BTO films. Crystallinity is improved after vacuum annealing at 600??C. Two-dimensional XRD confirms the tetragonal structure and orientation of 720-nm thick films. The effect of the annealing process on the BTO structure is discussed. A clean STO/Si interface is found using in-situ X-ray photoelectron spectroscopy and confirmed by cross-sectional scanning transmission electron microscopy. The capacitance-voltage characteristics of 720?nm-thick BTO films are examined and show an effective dielectric constant of ?660 for the heterostructure.

  4. Aluminum Stabilized NbTi Conductor Test Coil Design, Fabrication, and Test Results

    SciTech Connect (OSTI)

    Andreev, N.; Chlachidze, G.; Evbota, D.; Kashikhin, V.S.; Lamm, M.; Makarov, A.; Tartaglia, M.; Nakamoto, T.; Ogitsu, T.; Tanaka, K.; Yamamoto, A.; /KEK, Tsukuba

    2011-09-01

    A new generation of precision muon conversion experiments is planned at both Fermilab and KEK. These experiments will depend upon a complex set of solenoid magnets for the production, momentum selection and transport of a muon beam to a stopping target, and for tracking detector momentum analysis of candidate conversion electrons from the target. Baseline designs for the production and detector solenoids use NbTi cable that is heavily stabilized by an extruded high RRR aluminum jacket. A U.S.-Japan research collaboration has begun whose goal is to advance the development of optimized Al-NbTi conductors, gain experience with the technology of winding coils from this material, and test the conductor performance as modest length samples become available. For this purpose, a 'conductor test' solenoid with three coils was designed and built at Fermilab. A sample of the RIKEN Al-NbTi conductor from KEK was wound into a 'test' coil; this was sandwiched between two 'field' coils wound from doubled SSC cable, to increase the peak field on the RIKEN test coil. All three solenoid coils were epoxy impregnated, and utilized aluminum outer bandage rings to apply preload to the coils when cold. The design and fabrication details, and results of the magnet quench performance tests are presented and discussed.

  5. Influence of fatigue on the nanohardness of NiTiCr-wires

    SciTech Connect (OSTI)

    Frotscher, M.; Young, M. L.; Bei, Hongbin; George, Easo P; Neuking, K.; Eggeler, G.

    2009-01-01

    Testing parameters, such as rotational speed and bending radius, have a strong influence on the fatigue life of pseudoelastic NiTi shape-memory alloys during bending rotation fatigue (BRF) experiments [M. F. X. Wagner, Int. J. Mat. Res. 97 (2006), p. 1687-1696. and M. Frotscher, et al., Thermomechanical processing, microstructure and bending rotation fatigue of ultra-fine grained NiTiCr-wires, Proceedings of the International Conference for Shape Memory and Superelastic Technologies (SMST 2007), Tsukuba, Japan, ASM International, (2008), p. 149-158.]. Previous studies showed a decrease in the fatigue life for smaller bending radius (i.e. higher equivalent strain) and larger rotational speed. This observation is associated with an increase of dislocation density, the stabilization of stressinduced martensite during cycling, and an increase of the plateau stresses due to self-heating. In the present study, we examine the influence of these fatigue parameters on the nanohardness and shape recovery of pseudoelastic NiTiCr shape-memory alloy wires by nanoindentation. We show that nanoindentation is a suitable method for the characterization of fatigue-related microstructural changes, which affect the mechanical properties.

  6. A simplified model of TiH1.65/KClO4 pyrotechnic ignition.

    SciTech Connect (OSTI)

    Chen, Ken Shuang

    2009-04-01

    A simplified model was developed and is presented in this report for simulating thermal transport coupled with chemical reactions that lead to the pyrotechnic ignition of TiH1.65/KClO4 powder. The model takes into account Joule heating via a bridgewire, thermal contact resistance at the wire/powder interface, convective heat loss to the surroundings, and heat released from the TiH1.65- and KClO4-decomposition and TiO2-oxidation reactions. Chemical kinetic sub-models were put forth to describe the chemical reaction rate(s) and quantify the resultant heat release. The simplified model predicts pyrotechnic ignition when heat from the pyrotechnic reactions is accounted for. Effects of six key parameters on ignition were examined. It was found that the two reaction-rate parameters and the thermal contact resistance significantly affect the dynamic ignition process whereas the convective heat transfer coefficient essentially has no effect on the ignition time. Effects of the initial/ambient temperature and electrical current load through the wire are as expected. Ignition time increases as the initial/ambient temperature is lowered or the wire current load is reduced. Lastly, critical needs such as experiments to determine reaction-rate and other model-input parameters and to measure temperature profiles, time to ignition and burn-rate data for model validation as well as efforts in incorporating reaction-rate dependency on pressure are pointed out.

  7. Epitaxial growth of NiTiO3 with a distorted ilmenite structure

    SciTech Connect (OSTI)

    Varga, Tamas; Droubay, Timothy C.; Bowden, Mark E.; Nachimuthu, Ponnusamy; Shutthanandan, V.; Bolin, Trudy B.; Shelton, William A.; Chambers, Scott A.

    2012-06-30

    MTiO3 (M = Fe, Mn, Ni) compounds have received recent attention as possible candidates for new multiferroic materials capable of magnetization switching by application of an electric field. Epitaxial Ni1-xTi1-yO3 films of different thickness and composition were deposited on Al2O3(0001) by pulsed laser deposition, and characterized using several techniques. Structural parameters for the metastable LiNbO3-type NiTiO3 structure with the space group R3c were predicted using density functional theory calculations, and compared with the experimental results. Our structural data from x-ray diffraction and x-ray absorption spectroscopy indicate that epitaxial ilmenite-type NiTiO3 films were successfully grown. Furthermore, lattice strain exerted by the sapphire substrate results in a distorted ilmenite structure similar to the LiNbO3-type one. Our results demonstrate the potential of oxide heteroepitaxy to stabilize metastable multiferroic phases that may be difficult to prepare or are inaccessible in the bulk.

  8. Cr-doped TiSe2 - A layered dichalcogenide spin glass

    SciTech Connect (OSTI)

    Luo, Huixia; Tao, Jing; Krizan, Jason W.; Seibel, Elizabeth M.; Xie, Weiwei; Sahasrabudhe, Girija S.; Bergman, Susanna L.; Phelan, Brendan F.; Wang, Zhen; Zhang, Jiandi; Cava, R. J.

    2015-09-17

    We report the magnetic characterization of the Cr-doped layered dichalcogenide TiSe2. The temperature dependent magnetic susceptibilities are typical of those seen in geometrically frustrated insulating antiferromagnets. The Cr moment is close to the spin-only value, and the Curie–Weiss temperatures (θcw) are between –90 and –230 K. Freezing of the spin system, which is glassy, characterized by peaks in the ac and dc susceptibility and specific heat, does not occur until below T/θcw = 0.05. The CDW transition seen in the resistivity for pure TiSe2 is still present for 3% Cr substitution but is absent by 10% substitution, above which the materials are metallic and p-type. Structural refinements, magnetic characterization, and chemical considerations indicate that the materials are of the type Ti1–xCrxSe2-x/2 for 0 ≤ x ≤ 0.6.

  9. Hard X-ray emission and {sup 44}Ti line features of the Tycho supernova remnant

    SciTech Connect (OSTI)

    Wang, Wei [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Li, Zhuo, E-mail: wangwei@bao.ac.cn, E-mail: zhuo.li@pku.edu.cn [Department of Astronomy and Kavli Institute for Astronomy and Astrophysics, Peking University, Beijing 100871 (China)

    2014-07-10

    A deep hard X-ray survey of the International Gamma-Ray Astrophysics Laboratory (INTEGRAL) satellite has detected for the first time non-thermal emission up to 90 keV in the Tycho supernova (SN) remnant. Its 3-100 keV spectrum is fitted with a thermal bremsstrahlung of kT ? 0.81 0.45 keV plus a power-law model of ? ? 3.01 0.16. Based on diffusive shock acceleration theory, this non-thermal emission, together with radio measurements, implies that the Tycho remnant may not accelerate protons up to >PeV but to hundreds TeV. Only heavier nuclei may be accelerated to the cosmic ray spectral 'knee'. In addition, using INTEGRAL, we search for soft gamma-ray lines at 67.9 and 78.4 keV that come from the decay of radioactive {sup 44}Ti in the Tycho remnant. A bump feature in the 60-90 keV energy band, potentially associated with the {sup 44}Ti line emission, is found with a marginal significance level of ?2.6?. The corresponding 3? upper limit on the {sup 44}Ti line flux amounts to 1.5 10{sup 5} photon cm{sup 2} s{sup 1}. Implications on the progenitor of the Tycho SN, considered to be a Type Ia SN prototype, are discussed.

  10. Mechanical and functional behavior of high-temperature Ni-Ti-Pt shape memory alloys

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Buchheit, Thomas E.; Susan, Donald F.; Massad, Jordan E.; McElhanon, James R.; Noebe, Ronald D.

    2016-01-22

    A series of Ti-rich Ni-Ti-Pt ternary alloys with 13 to 18 at. pct Pt were processed by vacuum arc melting and characterized for their transformation behavior to identify shape memory alloys (SMA) that undergo transformation between 448 K and 498 K (175 °C and 225 °C) and achieve recoverable strain exceeding 2 pct. From this broader set of compositions, three alloys containing 15.5 to 16.5 at. pct Pt exhibited transformation temperatures in the vicinity of 473 K (200 °C), thus were targeted for more detailed characterization. Preliminary microstructural evaluation of these three compositions revealed a martensitic microstructure with small amountsmore » of Ti2(Ni,Pt) particles. Room temperature mechanical testing gave a response characteristic of martensitic de-twinning followed by a typical work-hardening behavior to failure. Elevated mechanical testing, performed while the materials were in the austenitic state, revealed yield stresses of approximately 500 MPa and 3.5 pct elongation to failure. Thermal strain recovery characteristics were more carefully investigated with unbiased incremental strain-temperature tests across the 1 to 5 pct strain range, as well as cyclic strain-temperature tests at 3 pct strain. As a result, the unbiased shape recovery results indicated a complicated strain recovery path, dependent on prestrain level, but overall acceptable SMA behavior within the targeted temperature and recoverable strain range.« less

  11. Interface Architecture Determined Electrocatalytic Activity of Pt on Vertically Oriented TiO2 Nanotubes

    SciTech Connect (OSTI)

    R Rettew; N Allam; F Alamgir

    2011-12-31

    The surface atomic structure and chemical state of Pt is consequential in a variety of surface-intensive devices. Herein we present the direct interrelationship between the growth scheme of Pt films, the resulting atomic and electronic structure of Pt species, and the consequent activity for methanol electro-oxidation in Pt/TiO{sub 2} nanotube hybrid electrodes. X-ray photoelectron spectroscopy (XPS) and X-ray absorption spectroscopy (XAS) measurements were performed to relate the observed electrocatalytic activity to the oxidation state and the atomic structure of the deposited Pt species. The atomic structure as well as the oxidation state of the deposited Pt was found to depend on the pretreatment of the TiO{sub 2} nanotube surfaces with electrodeposited Cu. Pt growth through Cu replacement increases Pt dispersion, and a separation of surface Pt atoms beyond a threshold distance from the TiO{sub 2} substrate renders them metallic, rather than cationic. The increased dispersion and the metallic character of Pt results in strongly enhanced electrocatalytic activity toward methanol oxidation. This study points to a general phenomenon whereby the growth scheme and the substrate-to-surface-Pt distance dictates the chemical state of the surface Pt atoms, and thereby, the performance of Pt-based surface-intensive devices.

  12. Cr-doped TiSe2 - A layered dichalcogenide spin glass

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Luo, Huixia; Tao, Jing; Krizan, Jason W.; Seibel, Elizabeth M.; Xie, Weiwei; Sahasrabudhe, Girija S.; Bergman, Susanna L.; Phelan, Brendan F.; Wang, Zhen; Zhang, Jiandi; et al

    2015-09-17

    We report the magnetic characterization of the Cr-doped layered dichalcogenide TiSe2. The temperature dependent magnetic susceptibilities are typical of those seen in geometrically frustrated insulating antiferromagnets. The Cr moment is close to the spin-only value, and the Curie–Weiss temperatures (θcw) are between –90 and –230 K. Freezing of the spin system, which is glassy, characterized by peaks in the ac and dc susceptibility and specific heat, does not occur until below T/θcw = 0.05. The CDW transition seen in the resistivity for pure TiSe2 is still present for 3% Cr substitution but is absent by 10% substitution, above which themore » materials are metallic and p-type. Structural refinements, magnetic characterization, and chemical considerations indicate that the materials are of the type Ti1–xCrxSe2-x/2 for 0 ≤ x ≤ 0.6.« less

  13. The local structure and ferromagnetism in Fe-implanted SrTiO? single crystals

    SciTech Connect (OSTI)

    Lobacheva, O. Chavarha, M.; Yiu, Y. M.; Sham, T. K.; Goncharova, L. V.

    2014-07-07

    We report a connection between the local structure of low-level Fe impurities and vacancies as the cause of ferromagnetic behavior observed in strontium titanate single crystals (STO), which were implanted with Fe and Si ions at different doses then annealed in oxygen. The effects of Fe doping and post-implantation annealing of STO were studied by X-ray Absorption Near Edge Structure (XANES) spectroscopy and Superconducting Quantum Interference Device magnetometry. XANES spectra for Fe and Ti K- and L-edge reveal the changes in the local environment of Fe and Ti following the implantation and annealing steps. The annealing in oxygen atmosphere partially healed implantation damages and changed the oxidation state of the implanted iron from metallic Fe? to Fe?/Fe? oxide. The STO single crystals were weak ferromagnets prior to implantation. The maximum saturation moment was obtained after our highest implantation dose of 210? Fe atom/cm, which could be correlated with the metallic Fe? phases in addition to the presence of O/Ti vacancies. After recrystallization annealing, the ferromagnetic response disappears. Iron oxide phases with Fe? and Fe? corresponding to this regime were identified and confirmed by calculations using Real Space Multiple Scattering program (FEFF9).

  14. Dielectric investigations in nanostructured tetragonal BaTiO{sub 3} ceramics

    SciTech Connect (OSTI)

    Silveira, L.G.D.; Alves, M.F.S.; Ctica, L.F.; Gotardo, R.A.M.; Nascimento, W.J.; Garcia, D.; Eiras, J.A.; Santos, I.A.

    2013-05-15

    Highlights: ? Nanostructured BaTiO{sub 3} ceramics processed by an innovative protocol. ? Dielectric relaxations related to strains and vacancies. ? Dielectric and ferroelectric properties enhanced by strain. - Abstract: In this paper, structural and dielectric properties of BaTiO{sub 3} ceramics obtained under extreme conditions were investigated. The temperature dependent dielectric investigations revealed that the phase transition temperatures of the BaTiO{sub 3} ceramics were raised as a function of residual strains associated to the nanostructuration, while structural characterizations showed a tetragonal arrangement at room temperature. From the frequency dependence analyses of the imaginary parts of dielectric permittivity, impedance and modulus function, three relaxation processes were identified. Two of them exhibit activation energies of 0.45 and 0.63 eV, and were attributed to single and double-ionization of oxygen vacancies. The whole set of results also indicated that the electrons resulting from the ionization of oxygen vacancies are trapped and do not contribute to the electrical conductivity, while the physical properties of the analyzed samples were enhanced by retaining a strained microstructure.

  15. Physical properties and electronic structure of a new barium titanate suboxide Ba1+δTi13-δO₁₂ (δ = 0.11)

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Rotundu, Costel R.; Jiang, Shan; Deng, Xiaoyu; Qian, Yiting; Khan, Saeed; Hawthorn, David G.; Kotliar, Gabriel; Ni, Ni

    2015-04-01

    The structure, transport, thermodynamic properties, x-ray absorption spectra (XAS), and electronic structure of a new barium titanate suboxide, Ba1+δTi13-δO₁₂ (δ = 0.11), are reported. It is a paramagnetic poor metal with hole carriers dominating the transport. Fermi liquid behavior appears at low temperature. The oxidization state of Ti obtained by the XAS is consistent with the metallic Ti²⁺ state. Local density approximation band structure calculations reveal the material is near the Van Hove singularity. The pseudogap behavior in the Ti-d band and the strong hybridization between the Ti-d and O-p orbitals reflect the characteristics of the building blocks of themore »Ti₁₃ semi-cluster and the TiO₄ quasi-squares, respectively.« less

  16. Structural evolution across the insulator-metal transition in oxygen-deficient BaTiO3-δ studied using neutron total scattering and Rietveld analysis

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Jeong, I.-K.; Lee, Seunghun; Jeong, Se-Young; Won, C. J.; Hur, N.; Llobet, A.

    2011-08-29

    Oxygen-deficient BaTiO3-δ exhibits an insulator-metal transition with increasing δ. We performed neutron total scattering measurements to study structural evolution across an insulator-metal transition in BaTiO3-δ. Despite its significant impact on resistivity, slight oxygen reduction (δ=0.09) caused only a small disturbance on the local doublet splitting of Ti-O bond. This finding implies that local polarization is well preserved under marginal electric conduction. In the highly oxygen-deficient metallic state (δ=0.25), however, doublet splitting of the Ti-O bond became smeared. The smearing of the local Ti-O doublet is complemented with long-range structural analysis and demonstrates that the metallic conduction in the highly oxygen-reducedmore » BaTiO3-δ is due to the appearance of nonferroelectric cubic lattice.« less

  17. A transmission electron microscopy study of the deformation behavior underneath nanoindents in nano-scale Al-TiN multilayered composites

    SciTech Connect (OSTI)

    Bhattacharyya, Dhriti; Mara, Nathan A; Dickerson, Patricia O; Misra, Amit; Hoagland, R G

    2009-01-01

    Nano-scale multilayered Al-TiN composites were deposited with DC magnetron sputtering technique in two different layer thickness ratios - Al:TiN = 1:1 and Al:TiN = 9:1. The Al layer thickness varied from 2 nm to 450 nm. The hardness of the samples was tested by nanoindentation using a Berkovich tip. Cross-sectional Transmission Electron Microscopy (TEM) was carried out on samples extracted with Focused Ion Beam (FIB) from below the nanoindents. This paper presents the results of the hardness tests in the Al-TiN multilayers with the two different thickness ratios and the observations from the cross-sectional TEM studies of the regions underneath the indents. These studies showed remarkable strength in the multilayers, as well as some very interesting deformation behavior in the TiN layers at extremely small length scales, where the hard TiN layers undergo co-deformation with the Al layers.

  18. TiO2 nanotube arrays for photocatalysis: Effects of crystallinity, local order, and electronic structure

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Liu, Jing; Hosseinpour, Pegah M.; Luo, Si; Heiman, Don; Menon, Latika; Arena, Dario A.; Lewis, Laura H.

    2014-11-19

    To furnish insight into correlations of electronic and local structure and photoactivity, arrays of short and long TiO₂ nanotubes were synthesized by electrochemical anodization of Ti foil, followed by thermal treatment in O₂ (oxidizing), Ar (inert), and H₂ (reducing) environments. The physical and electronic structures of these nanotubes were probed with x-ray diffraction, scanning electron microscopy, and synchrotron-based x-ray absorption spectroscopy, and correlated with their photocatalytic properties. The photocatalytic activity of the nanotubes was evaluated by monitoring the degradation of methyl orange under UV-VIS light irradiation. Results show that upon annealing at 350 °C all as-anodized amorphous TiO₂ nanotube samplesmore » partially transform to the anatase structure, with variations in the degree of crystallinity and in the concentration of local defects near the nanotubes' surface (~5 nm) depending on the annealing conditions. Degradation of methyl orange was not detectable for the as-anodized TiO₂ nanotubes regardless of their length. The annealed long nanotubes demonstrated detectable catalytic activity, which was more significant with the H₂-annealed nanotubes than with the Ar- and O₂-annealed nanotube samples. This enhanced photocatalytic response of the H₂-annealed long nanotubes relative to the other samples is positively correlated with the presence of a larger concentration of lattice defects (such as Ti3+ and anticipated oxygen vacancies) and a slightly lower degree of crystallinity near the nanotube surface. These physical and electronic structural attributes impact the efficacy of visible light absorption; moreover, the increased concentration of surface defects is postulated to promote the generation of hydroxyl radicals and thus accelerate the photodegradation of the methyl orange. The information obtained from this study provides unique insight into the role of the near-surface electronic and defect structure, crystal structure, and the local chemical environment on the photocatalytic activity and may be employed for tailoring the materials' properties for photocatalysis and other energy-related applications.« less

  19. PH dependent adhesive peptides

    DOE Patents [OSTI]

    Tomich, John; Iwamoto, Takeo; Shen, Xinchun; Sun, Xiuzhi Susan

    2010-06-29

    A novel peptide adhesive motif is described that requires no receptor or cross-links to achieve maximal adhesive strength. Several peptides with different degrees of adhesive strength have been designed and synthesized using solid phase chemistries. All peptides contain a common hydrophobic core sequence flanked by positively or negatively charged amino acids sequences.

  20. Spontaneous formation of suboxidic coordination around Co in ferromagnetic rutile Ti0.95Co0.5O2 film

    DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

    Hu, Wen; Hayaski, Kouichi; Fukumura, Tomoteru; Akagi, Kazuto; Tsukada, Masaru; Happo, Naohisa; Hosokawa, Shinya; Ohwada, Kenji; Takahasi, Masamitu; Suzuki, Motohiro; et al

    2015-06-02

    To evaluate local atomic structures around Co in high temperature diluted ferromagnetic semiconductor Co-doped TiO2, x-ray fluorescence holography and x-ray absorption fine structure experiments were carried out on rutile paramagnetic Ti0.99Co0.01O2 and ferromagnetic Ti0.95Co0.05O2 films. The Co atoms in the Ti0.99Co0.01O2 simply substituted for Ti sites in the rutile structure, whereas a suboxidic arrangement of CoO2Ti4 formed around Co in the Ti0.95Co0.05O2 films. A theoretical investigation based on a series of first-principles calculations indicated the stability of the aggregated suboxidic clusters in the rutile TiO2, supporting our hypothesis for the formation of suboxidic coordination in the highly Co-doped sample. Asmore » a result, the suboxidic coordination may be the source of strong exchange interaction, resulting in the high Curie temperature in Co-doped TiO2.« less