National Library of Energy BETA

Sample records for monosodium titanate mst

  1. LEACHING OF TITANIUM FROM MONOSODIUM TITANATE AND MODIFIED MST

    SciTech Connect (OSTI)

    Taylor-Pashow, K.; Fondeur, F.; Fink, S.

    2012-08-01

    Analysis of a fouled coalescer and pre-filters from Actinide Removal Process/Modular Caustic Side Solvent Extraction Unit (ARP/MCU) operations showed evidence of Ti containing solids. Based on these results a series of tests were planned to examine the extent of Ti leaching from monosodium titanate (MST) and modified monosodium titanate (mMST) in various solutions. The solutions tested included a series of salt solutions with varying free hydroxide concentrations, two sodium hydroxide concentrations, 9 wt % and 15 wt %, nitric and oxalic acid solutions. Overall, the amount of Ti leached from the MST and mMST was much greater in the acid solutions compared to the sodium hydroxide or salt solutions, which is consistent with the expected trend. The leaching data also showed that increasing hydroxide concentration, whether pure NaOH solution used for filter cleaning in ARP or the waste salt solution, increased the amount of Ti leached from both the MST and mMST. For the respective nominal contact times with the MST solids - for filter cleaning or the normal filter operation, the dissolved Ti concentrations are comparable suggesting either cause may contribute to the increased Ti fouling on the MCU coalescers. Tests showed that Ti containing solids could be precipitated from solution after the addition of scrub acid and a decrease in temperature similar to expected in MCU operations. FTIR analysis of these solids showed some similarity to the solids observed on the fouled coalescer and pre-filters. Although only a cursory study, this information suggests that the practice of increasing free hydroxide in feed solutions to MCU as a mitigation to aluminosilicate formation may be offset by the impact of formation of Ti solids in the overall process. Additional consideration of this finding from MCU and SWPF operation is warranted.

  2. RADIUM AND THORIUM SORPTION BY MONOSODIUM TITANATE (MST) AND MODIFIED MST (mMST)

    SciTech Connect (OSTI)

    Taylor-Pashow, K.; Hobbs, D.

    2012-02-15

    A series of tests were planned to examine the removal of Ra and Th by monosodium titanate (MST) and modified monosodium titanate (mMST). Simulated waste solutions were prepared containing Ra and Th, along with Sr, Np, Pu, and U. Following simulant preparation the simulants were filtered through 0.45-m filters. Analysis of the simulants indicated no Th in the filtered solution. This is due to the very low solubility of Th in alkaline solutions. Based on the reported detection limits for {sup 228}Th by gamma analyses, the solubility of Th in the simulant solutions is < 3.0E-10 g/L or < 1.3E-12 M. Therefore, data could not be obtained regarding the removal of Th by MST and mMST; however, testing proceeded to examine the removal of Ra. Sorption testing indicated that Ra, like Sr, is very rapidly removed from solution by both MST and mMST. The Ra concentration in solution fell below the method detection limit (MDL) within 30 minutes of contact with MST, and within 2 hours of contact with mMST, when tested at 25 C using a 5.6 M Na simulant. Additional testing examined the effects of ionic strength and temperature on the MST and mMST performance. Results from these tests showed that the majority of samples still reached a Ra concentration below the MDL, indicating excellent removal. For the highest ionic strength solution (6.6 M Na), there did appear to be a slight decrease in the Ra removal by mMST, as indicated by a larger number of samples just above the MDL. The effect of temperature on {sup 226}Ra removal is indeterminate for either MST or mMST in the temperature range (25-60 C) and concentrations studied since the final soluble concentration of Ra remained at or below the detection limits for all tests. Desorption testing was also performed using decontaminated salt solution (DSS) diluted to sodium concentrations of 2 M and 0.5 M, to represent the intermediate and final stages of washing. Results from these tests indicated no desorption of any sorbents, with the

  3. Rheology Of MonoSodium Titanate (MST) And Modified Mst (mMST) Mixtures Relevant To The Salt Waste Processing Facility

    SciTech Connect (OSTI)

    Koopman, D. C.; Martino, C. J.; Shehee, T. C.; Poirier, M. R.

    2013-07-31

    The Savannah River National Laboratory performed measurements of the rheology of suspensions and settled layers of treated material applicable to the Savannah River Site Salt Waste Processing Facility. Suspended solids mixtures included monosodium titanate (MST) or modified MST (mMST) at various solid concentrations and soluble ion concentrations with and without the inclusion of kaolin clay or simulated sludge. Layers of settled solids were MST/sludge or mMST/sludge mixtures, either with or without sorbed strontium, over a range of initial solids concentrations, soluble ion concentrations, and settling times.

  4. TESTING AND CHARACTERIZATION OF ENGINEERED FORMS OF MONOSODIUM TITANATE (MST)

    SciTech Connect (OSTI)

    Taylor-Pashow, K.; Nash, C.; Hobbs, D.

    2012-05-14

    Engineered forms of MST and mMST were prepared at ORNL using an internal gelation process. Samples of these two materials were characterized at SRNL to examine particle size and morphology, peroxide content, tapped densities, and Na, Ti, and C content. Batch contact tests were also performed to examine the performance of the materials. The {sup E}mMST material was found to contain less than 10% of the peroxide found in a freshly prepared batch of mMST. This was also evidenced in batch contact testing with both simulated and actual waste, where little difference in performance was seen between the two engineered materials, {sup E}MST and {sup E}mMST. Based on these results, attempts were made to increase the peroxide content of the materials by post-treatment with hydrogen peroxide. The peroxide treatment resulted in a slight ({approx}10%) increase in peroxide content; however, the peroxide:Ti molar ratio was still much lower ({approx}0.1 X) than what is seen in a freshly prepared batch of mMST. Testing with simulated waste showed the performance of the peroxide treated materials was improved. Batch contact tests were also performed with an earlier (2003) prepared lot of {sup E}MST to examine the effect of ionic strength on the performance of the material. In general the results showed a decrease in removal performance with increasing ionic strength, which is consistent with previous testing with MST. A Sr loading isotherm was also determined, and the {sup E}MST material was found to reach a Sr loading as high as 13.2 wt % after 100 days of contact at a phase ratio of 20000 mL/g. At the typical MST phase ratio of 2500 mL/g (0.4 g/L), a Sr loading of 2.64 wt % was reached after 506 hours of contact. Samples of {sup E}MST and the post-peroxide treated {sup E}mMST were also tested in a column configuration using simulated waste solution. The breakthrough curves along with analysis of the sorbent beds at the conclusion of the experiments showed that the peroxide treated

  5. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #120111

    SciTech Connect (OSTI)

    Shehee, T.

    2012-02-21

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot No.120111 qualification and the first 12 verification samples met all the requirements in the specification indicating the material is acceptable for use in the process. Analyses of Pail 125 verification sample fails the criteria for solids content and has measurably lower pH, density, and total bottle weight. The verification sample for Pail 125 was retested for weight percent solids after checking that all of the solids had been suspended. The sample again failed to meet acceptance criteria. SRNL recommends accepting Pails 1 through 120. Pails 121 through 125 should be rejected and returned to the vendor.

  6. SORPTION BEHAVIOR OF MONOSODIUM TITANATE AND AMORPHOUS PEROXOTITANATE MATERIALS UNDER WEAKLY ACIDIC CONDITIONS

    SciTech Connect (OSTI)

    Hobbs, D.; Elvington, M.; Click, D.

    2009-11-11

    Inorganic, titanate-based sorbents are tested with respect to adsorption of a variety of sorbates under weakly acidic conditions (pH 3). Specifically, monosodium titanate (MST) and amorphous peroxotitanate (APT) sorption characteristics are initially probed through a screening process consisting of a pair of mixed metal solutions containing a total of 29 sorbates including alkali metals, alkaline earth metals, transition metals, metalloids and nonmetals. MST and APT sorption characteristics are further analyzed individually with chromium(III) and cadmium(II) using a batch method at ambient laboratory temperature, varying concentrations of the sorbents and sorbates and contact times. Maximum sorbate loadings are obtained from the respective adsorption isotherms.

  7. ANALYSIS OF HARRELL MONOSODIUM TITANATE LOT #s 46000606120, 46000722120, AND 46000808120

    SciTech Connect (OSTI)

    Taylor-Pashow, K.

    2012-10-08

    Monosodium titanate (MST) for use in the Actinide Removal Process (ARP) must be qualified and verified in advance. A single qualification sample for each batch of material is sent to SRNL for analysis, as well as a statistical sampling of verification samples. The Harrell Industries Lot #s 46000706120, 46000722120, and 460008081120 qualification and verification samples met each of the selected specification requirements that were tested with the exception of a few pails being marginally below the lower weight percent solids limit. These deviations from the specifications are viewed as negligible since the corresponding density of the slurries indicates no appreciable shortage of MST solids. Therefore, SRNL recommends acceptance and use of these pails.

  8. PILOT SCALE TESTING OF MONOSODIUM TITANATE MIXING FOR THE SRS SMALL COLUMN ION EXCHANGE PROCESS - 11224

    SciTech Connect (OSTI)

    Poirier, M.; Restivo, M.; Williams, M.; Herman, D.; Steeper, T.

    2011-01-25

    The Small Column Ion Exchange (SCIX) process is being developed to remove cesium, strontium, and select actinides from Savannah River Site (SRS) Liquid Waste using an existing waste tank (i.e., Tank 41H) to house the process. Savannah River National Laboratory (SRNL) is conducting pilot-scale mixing tests to determine the pump requirements for suspending monosodium titanate (MST), crystalline silicotitanate (CST), and simulated sludge. The purpose of this pilot scale testing is to determine the requirements for the pumps to suspend the MST particles so that they can contact the strontium and actinides in the liquid and be removed from the tank. The pilot-scale tank is a 1/10.85 linear scaled model of SRS Tank 41H. The tank diameter, tank liquid level, pump nozzle diameter, pump elevation, and cooling coil diameter are all 1/10.85 of their dimensions in Tank 41H. The pump locations correspond to the proposed locations in Tank 41H by the SCIX program (Risers B5 and B2 for two pump configurations and Risers B5, B3, and B1 for three pump configurations). The conclusions from this work follow: (i) Neither two standard slurry pumps nor two quad volute slurry pumps will provide sufficient power to initially suspend MST in an SRS waste tank. (ii) Two Submersible Mixer Pumps (SMPs) will provide sufficient power to initially suspend MST in an SRS waste tank. However, the testing shows the required pump discharge velocity is close to the maximum discharge velocity of the pump (within 12%). (iii) Three SMPs will provide sufficient power to initially suspend MST in an SRS waste tank. The testing shows the required pump discharge velocity is 66% of the maximum discharge velocity of the pump. (iv) Three SMPs are needed to resuspend MST that has settled in a waste tank at nominal 45 C for four weeks. The testing shows the required pump discharge velocity is 77% of the maximum discharge velocity of the pump. Two SMPs are not sufficient to resuspend MST that settled under these

  9. THE HYDROTHERMAL REACTIONS OF MONOSODIUM TITANATE, CRYSTALLINE SILICOTITANATE AND SLUDGE IN THE MODULAR SALT PROCESS: A LITERATURE SURVEY

    SciTech Connect (OSTI)

    Fondeur, F.; Pennebaker, F.; Fink, S.

    2010-11-11

    The use of crystalline silicotitanate (CST) is proposed for an at-tank process to treat High Level Waste at the Savannah River Site. The proposed configuration includes deployment of ion exchange columns suspended in the risers of existing tanks to process salt waste without building a new facility. The CST is available in an engineered form, designated as IE-911-CW, from UOP. Prior data indicates CST has a proclivity to agglomerate from deposits of silica rich compounds present in the alkaline waste solutions. This report documents the prior literature and provides guidance for the design and operations that include CST to mitigate that risk. The proposed operation will also add monosodium titanate (MST) to the supernate of the tank prior to the ion exchange operation to remove strontium and select alpha-emitting actinides. The cesium loaded CST is ground and then passed forward to the sludge washing tank as feed to the Defense Waste Processing Facility (DWPF). Similarly, the MST will be transferred to the sludge washing tank. Sludge processing includes the potential to leach aluminum from the solids at elevated temperature (e.g., 65 C) using concentrated (3M) sodium hydroxide solutions. Prior literature indicates that both CST and MST will agglomerate and form higher yield stress slurries with exposure to elevated temperatures. This report assessed that data and provides guidance on minimizing the impact of CST and MST on sludge transfer and aluminum leaching sludge.

  10. Microsoft Word - eMST report - for signature.docx

    Office of Scientific and Technical Information (OSTI)

    2-00193 Revision 0 Testing and Characterization of Engineered Forms of Monosodium Titanate (MST) K. M. L. Taylor-Pashow C. A. Nash D. T. Hobbs May 2012 Savannah River National...

  11. FATE OF FISSILE MATERIAL BOUND TO MONOSODIUM TITANATE DURING COOPER CATALYZED PEROXIDE OXIDATION OF TANK 48H WASTE

    SciTech Connect (OSTI)

    Taylor-Pashow, K.

    2012-08-09

    At the Savannah River Site (SRS), Tank 48H currently holds approximately 240,000 gallons of slurry which contains potassium and cesium tetraphenylborate (TPB). A copper catalyzed peroxide oxidation (CCPO) reaction is currently being examined as a method for destroying the TPB present in Tank 48H. Part of the development of that process includes an examination of the fate of the Tank 48H fissile material which is adsorbed onto monosodium titanate (MST) particles. This report details results from experiments designed to examine the potential degradation of MST during CCPO processing and the subsequent fate of the adsorbed fissile material. Experiments were conducted to simulate the CCPO process on MST solids loaded with sorbates in a simplified Tank 48H simulant. Loaded MST solids were placed into the Tank 48H simplified simulant without TPB, and the experiments were then carried through acid addition (pH adjustment to 11), peroxide addition, holding at temperature (50 C) for one week, and finally NaOH addition to bring the free hydroxide concentration to a target concentration of 1 M. Testing was conducted without TPB to show the maximum possible impact on MST since the competing oxidation of TPB with peroxide was absent. In addition, the Cu catalyst was also omitted, which will maximize the interaction of H{sub 2}O{sub 2} with the MST; however, the results may be non-conservative assuming the Cu-peroxide active intermediate is more reactive than the peroxide radical itself. The study found that both U and Pu desorb from the MST when the peroxide addition begins, although to different extents. Virtually all of the U goes into solution at the beginning of the peroxide addition, whereas Pu reaches a maximum of {approx}34% leached during the peroxide addition. Ti from the MST was also found to come into solution during the peroxide addition. Therefore, Ti is present with the fissile in solution. After the peroxide addition is complete, the Pu and Ti are found to

  12. PEROXOTITANATE- AND MONOSODIUM METAL-TITANATE COMPOUNDS AS INHIBITORS OF BACTERIAL GROWTH

    SciTech Connect (OSTI)

    Hobbs, D.

    2011-01-19

    Sodium titanates are ion-exchange materials that effectively bind a variety of metal ions over a wide pH range. Sodium titanates alone have no known adverse biological effects but metal-exchanged titanates (or metal titanates) can deliver metal ions to mammalian cells to alter cell processes in vitro. In this work, we test a hypothesis that metal-titanate compounds inhibit bacterial growth; demonstration of this principle is one prerequisite to developing metal-based, titanate-delivered antibacterial agents. Focusing initially on oral diseases, we exposed five species of oral bacteria to titanates for 24 h, with or without loading of Au(III), Pd(II), Pt(II), and Pt(IV), and measuring bacterial growth in planktonic assays through increases in optical density. In each experiment, bacterial growth was compared with control cultures of titanates or bacteria alone. We observed no suppression of bacterial growth by the sodium titanates alone, but significant (p < 0.05, two-sided t-tests) suppression was observed with metal-titanate compounds, particularly Au(III)-titanates, but with other metal titanates as well. Growth inhibition ranged from 15 to 100% depending on the metal ion and bacterial species involved. Furthermore, in specific cases, the titanates inhibited bacterial growth 5- to 375-fold versus metal ions alone, suggesting that titanates enhanced metal-bacteria interactions. This work supports further development of metal titanates as a novel class of antibacterials.

  13. Hydrogen peroxide modified sodium titanates with improved sorption capabilities

    DOE Patents [OSTI]

    Nyman, May D.; Hobbs, David T.

    2009-02-24

    The sorption capabilities (e.g., kinetics, selectivity, capacity) of the baseline monosodium titanate (MST) sorbent material currently being used to sequester Sr-90 and alpha-emitting radioisotopes at the Savannah River Site are significantly improved when treated with hydrogen peroxide; either during the original synthesis of MST, or, as a post-treatment step after the MST has been synthesized. It is expected that these peroxide-modified MST sorbent materials will have significantly improved sorption capabilities for non-radioactive cations found in industrial processes and waste streams.

  14. Large Particle Titanate Sorbents

    SciTech Connect (OSTI)

    Taylor-Pashow, K.

    2015-10-08

    This research project was aimed at developing a synthesis technique for producing large particle size monosodium titanate (MST) to benefit high level waste (HLW) processing at the Savannah River Site (SRS). Two applications were targeted, first increasing the size of the powdered MST used in batch contact processing to improve the filtration performance of the material, and second preparing a form of MST suitable for deployment in a column configuration. Increasing the particle size should lead to improvements in filtration flux, and decreased frequency of filter cleaning leading to improved throughput. Deployment of MST in a column configuration would allow for movement from a batch process to a more continuous process. Modifications to the typical MST synthesis led to an increase in the average particle size. Filtration testing on dead-end filters showed improved filtration rates with the larger particle material; however, no improvement in filtration rate was realized on a crossflow filter. In order to produce materials suitable for column deployment several approaches were examined. First, attempts were made to coat zirconium oxide microspheres (196 µm) with a layer of MST. This proved largely unsuccessful. An alternate approach was then taken synthesizing a porous monolith of MST which could be used as a column. Several parameters were tested, and conditions were found that were able to produce a continuous structure versus an agglomeration of particles. This monolith material showed Sr uptake comparable to that of previously evaluated samples of engineered MST in batch contact testing.

  15. DESORPTION OF SORBATES FROM MST, MMST, AND CST UNDER VARIOUS CONDITIONS

    SciTech Connect (OSTI)

    Taylor-Pashow, K.; Hobbs, D.

    2011-06-10

    The Small Column Ion Exchange (SCIX) Program (formerly referred to as the Modular Salt Processing (MSP) Project) seeks to deploy equipment to remove the {sup 134,137}Cs, {sup 90}Sr, and alpha-emitting radionuclides (principally {sup 238,239,240}Pu and {sup 237}Np) from the high level waste salt solutions. The equipment is installed within a high level waste tank to take advantage of the shielding provided by the waste tank. The process will involve adding monosodium titanate (MST) to the waste tank (i.e., Tank 41H) to sorb the Sr and select actinides, removing the MST and entrained sludge with in-riser rotary microfilters, and subsequently using ion-exchange columns containing crystalline silicotitanate (CST) to remove the Cs. After being loaded with Cs, the CST will be ground to reduce the particle size and then transferred into another waste tank (e.g., Tank 40H). The MST and sludge solids stream will be transported to a sludge batch preparation tank (i.e., Tank 42H or Tank 51H) once the SCIX batch is processed. Both streams, MST/solids and CST, will ultimately be transported into and vitrified inside the Defense Waste Processing Facility (DWPF). A series of experiments were performed to examine desorption from monosodium titanate (MST), modified monosodium titanate (mMST), and crystalline silicotitanate (CST) under various conditions. The first two experiments examined desorption from MST and CST under two different sludge treatment processes, aluminum dissolution and sludge washing. Desorption of all sorbates was observed to varying degrees under the aluminum dissolution conditions. The extent of desorption ranged from < 3% to about 50% after 4 weeks, with Pu exhibiting the lowest desorption. At the end of the experiment, the temperature was reduced from 65 C to 25 C and the tests monitored for an additional two weeks. After reducing the temperature, partial resorption of the sorbates was observed with both MST and CST. Under the sludge washing conditions, no

  16. Development of an improved sodium titanate for the pretreatment of nuclear waste at the Savannah River Site

    SciTech Connect (OSTI)

    Hobbs, D.T.; Poirier, M.R.; Barnes, M.J.; Peters, T.B.; Fondeur, F.F.; Thompson, M.E.; Fink, S.D. [Savannah River National Laboratory, Westinghouse Savannah River Company, Aiken, SC (United States); Nyman, M.D. [Sandia National Laboratories, Albuquerque, NM (United States)

    2008-07-01

    High-level nuclear waste produced from fuel reprocessing operations at the Savannah River Site (SRS) requires pretreatment to remove Cs-137, Sr-90 and alpha-emitting radionuclides (i.e., actinides) prior to disposal onsite as low level waste. Separation processes planned at SRS include sorption of Sr-90 and alpha-emitting radionuclides onto monosodium titanate (MST) and caustic side solvent extraction, for Cs-137 removal. The MST and separated Cs-137 will be encapsulated into a borosilicate glass wasteform for eventual entombment at the federal repository. The predominant alpha-emitting radionuclides in the highly alkaline waste solutions include plutonium isotopes Pu-238, Pu-239 and Pu-240. This paper describes recent results to produce an improved sodium titanate material that exhibits increased removal kinetics and capacity for Sr-90 and alpha-emitting radionuclides compared to the baseline MST material. (authors)

  17. Synthesis of nanosized sodium titanates

    DOE Patents [OSTI]

    Hobbs, David T.; Taylor-Pashow, Kathryn M. L.; Elvington, Mark C.

    2015-09-29

    Methods directed to the synthesis and peroxide-modification of nanosized monosodium titanate are described. Methods include combination of reactants at a low concentration to a solution including a nonionic surfactant. The nanosized monosodium titanate can exhibit high selectivity for sorbing various metallic ions.

  18. Titan

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

    titan Titan Titan is a two-beam laser platform. The nanosecond "long-pulse" beam is one of the Janus lasers, up to 1 kJ at 1.053 μm. The "short-pulse" beam is 1-to-10 ps and energies up to 250 J, depending on pulse duration. With a minimum pulse width of a few μm, intensities of 1021 W/cm2 and a contrast of 10-5 are typical. The beams can be used together or independently. Titan Laser Facility 3D Views of Target Chamber First download appropriate software (PC or Mac)

  19. INVESTIGATING SUSPENSION OF MST, CST, AND SIMULATED SLUDGE SLURRIES IN A PILOT-SCALE WASTE TANK

    SciTech Connect (OSTI)

    Poirier, M.; Qureshi, Z.; Restivo, M.; Steeper, T.; Williams, M.

    2011-05-24

    The Small Column Ion Exchange (SCIX) process is being developed to remove cesium, strontium, and actinides from Savannah River Site (SRS) Liquid Waste using an existing waste tank (i.e., Tank 41H) to house the process. Savannah River National Laboratory (SRNL) is conducting pilot-scale mixing tests to determine the pump requirements for suspending and resuspending monosodium titanate (MST), crystalline silicotitanate (CST), and simulated sludge. The purpose of this pilot scale testing is for the pumps to resuspend the MST, CST, and simulated sludge particles so that they can be removed from the tank, and to suspend the MST so it can contact strontium and actinides. The pilot-scale tank is a 1/10.85 linear scaled model of Tank 41H. The tank diameter, tank liquid level, pump nozzle diameter, pump elevation, and cooling coil diameter are all 1/10.85 of their dimensions in Tank 41H. The pump locations correspond to the proposed locations in Tank 41H by the SCIX program (Risers B5, B3, and B1). Previous testing showed that three Submersible Mixer Pumps (SMPs) will provide sufficient power to initially suspend MST in an SRS waste tank, and to resuspend MST that has settled in a waste tank at nominal 45 C for four weeks. The conclusions from this analysis are: (1) Three SMPs will be able to resuspend more than 99.9% of the MST and CST that has settled for four weeks at nominal 45 C. The testing shows the required pump discharge velocity is 84% of the maximum discharge velocity of the pump. (2) Three SMPs will be able to resuspend more than 99.9% of the MST, CST, and simulated sludge that has settled for four weeks at nominal 45 C. The testing shows the required pump discharge velocity is 82% of the maximum discharge velocity of the pump. (3) A contact time of 6-12 hours is needed for strontium sorption by MST in a jet mixed tank with cooling coils, which is consistent with bench-scale testing and actinide removal process (ARP) operation.

  20. Sample Results From The Interim Salt Disposition Program Macrobatch 7 Tank 21H Qualification MST Solids Sample

    SciTech Connect (OSTI)

    Washington, A. L. II; Peters, T. B.

    2013-09-19

    Savannah River National Laboratory (SRNL) performed experiments on qualification material for use in the Interim Salt Disposition Program (ISDP) Batch 7 processing. The Marcrobatch 7 material was received with visible fine particulate solids, atypical for these samples. The as received material was allowed to settle for a period greater than 24 hours. The supernatant was then decanted and utilized as our clarified feed material. As part of this qualification work, SRNL performed an Actinide Removal Process (ARP) test using the clarified feed material. From this test, the residual monosodium titanate (MST) was analyzed for radionuclide uptake after filtration from H-Tank Farm (HTF) feed salt solution. The results of these analyses are reported and are within historical precedent.

  1. SELECTIVE REMOVAL OF STRONTIUM AND CESIUM FROM SIMULATED WASTE SOLUTION WITH TITANATE ION-EXCHANGERS IN A FILTER CARTRIDGE CONFIGURATIONS-12092

    SciTech Connect (OSTI)

    Oji, L.; Martin, K.; Hobbs, D.

    2011-11-10

    Experimental results for the selective removal of strontium and cesium from simulated waste solutions with monosodium titanate (MST) and crystalline silicotitanate (CST) laden filter cartridges are presented. In these proof-of-principle tests, effective uptake of both Sr-85 and Cs-137 were observed using ion-exchangers in this filter cartridge configuration. At low salt simulant conditions, the instantaneous decontamination factor (D{sub F}) for Sr-85 with MST impregnated filter membrane cartridges measured 26, representing 96% Sr-85 removal efficiency. On the other hand, the Sr-85 instantaneous D{sub F} with co-sintered active MST cartridges measured 40 or 98% Sr-85 removal efficiency. Strontium-85 removal with the MST impregnated membrane cartridges and CST impregnated membrane cartridges, placed in series arrangement, produced an instantaneous decontamination factor of 41 compared to an instantaneous decontamination factor of 368 for strontium-85 with co-sintered active MST cartridges and co-sintered active CST cartridges placed in series. Overall, polyethylene co-sintered active titanates cartridges performed as well as titanate impregnated filter membrane cartridges in the uptake of strontium. At low ionic strength conditions, there was a significant uptake of Cs-137 with co-sintered CST cartridges. Tests results with CST impregnated membrane cartridges for Cs-137 decontamination are currently being re-evaluated. Based on these preliminary findings we conclude that incorporating MST and CST sorbents into membranes represent a promising method for the semi-continuous removal of radioisotopes of strontium and cesium from nuclear waste solutions.

  2. PILOT-SCALE TESTING OF THE SUSPENSION OF MST, CST, AND SIMULATED SLUDGE SLURRIES IN A SLUDGE TANK

    SciTech Connect (OSTI)

    Poirier, M.; Qureshi, Z.; Restivo, M.; Steeper, T.; Williams, M.; Herman, D.

    2011-08-02

    The Small Column Ion Exchange (SCIX) process is being developed to remove cesium, strontium, and actinides from Savannah River Site (SRS) Liquid Waste using an existing waste tank (i.e., Tank 41H) to house the process. Following strontium, actinide, and cesium removal, the concentrated solids will be transported to a sludge tank (i.e., monosodium titanate (MST)/sludge solids to Tank 42H or Tank 51H and crystalline silicotitanate (CST) to Tank 40H) for eventual transfer to the Defense Waste Processing Facility (DWPF). Savannah River National Laboratory (SRNL) is conducting pilot-scale mixing tests to determine the pump requirements for mixing MST, CST, and simulated sludge. The purpose of this pilot scale testing is to determine the pump requirements for mixing MST and CST with sludge in a sludge tank and to determine whether segregation of particles occurs during settling. Tank 40H and Tank 51H have four Quad Volute pumps; Tank 42H has four standard pumps. The pilot-scale tank is a 1/10.85 linear scaled model of Tank 40H. The tank diameter, tank liquid level, pump nozzle diameter, pump elevation, and cooling coil diameter are all 1/10.85 of their dimensions in Tank 40H. The pump locations correspond to the current locations in Tank 40H (Risers B2, H, B6, and G). The pumps are pilot-scale Quad Volute pumps. Additional settling tests were conducted in a 30 foot tall, 4 inch inner diameter clear column to investigate segregation of MST, CST, and simulated sludge particles during settling.

  3. MST - UW Plasma Physics

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

    UW-Madison > Physics Department > Plasma Physics Group > MST > MST Home UW Madison Madison Symmetric Torus MST Home MST HomeGraduate Student InformationLinksTourControl and Auxiliary SystemsPhysics TopicsDeviceResearch MissionMST People mst logo CPLA Home Directory Publications Links Internal University of Wisconsin Physics Department Research funding includes support from: Department of Energy National Science Foundation The Madison Symmetric Torus produces hot plasma for research

  4. MST Research Programs

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

    ADEPS » MST » MST Research Programs MST Research Programs Providing world-leading, innovative, and agile materials science and technology solutions for national security missions. Contact Us Division Leader David Teter Email Emphasizing the synergy among materials synthesis, processing, properties, and performance, the Materials Science and Technology Division applies fundamental materials science and technology expertise to a broad range of programs in support of national security needs,

  5. Device - MST - UW Plasma Physics

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

    Device UW Madison Madison Symmetric Torus Device MST HomeGraduate Student InformationLinksTourControl and Auxiliary SystemsPhysics TopicsDeviceResearch MissionMST People mst logo CPLA Home Directory Publications Links Internal University of Wisconsin Physics Department Research funding includes support from: Department of Energy National Science Foundation Anatomy of an MST shot The five capacitor banks behind the wall are charged from 2000 to 5000 Volts by the main power supply. A puff of

  6. INCORPORATION OF MONO SODIUM TITANATE AND CRYSTALLINE SILICOTITANATE FEEDS IN HIGH LEVEL NUCLEAR WASTE GLASS

    SciTech Connect (OSTI)

    Fox, K.; Johnson, F.; Edwards, T.

    2010-11-23

    Four series of glass compositions were selected, fabricated, and characterized as part of a study to determine the impacts of the addition of Crystalline Silicotitanate (CST) and Monosodium Titanate (MST) from the Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) glass waste form and the applicability of the DWPF process control models. All of the glasses studied were considerably more durable than the benchmark Environmental Assessment (EA) glass. The measured Product Consistency Test (PCT) responses were compared with the predicted values from the current DWPF durability model. One of the KT01-series and two of the KT03-series glasses had measured PCT responses that were outside the lower bound of the durability model. All of the KT04 glasses had durabilities that were predictable regardless of heat treatment or compositional view. In general, the measured viscosity values of the KT01, KT03, and KT04-series glasses are well predicted by the current DWPF viscosity model. The results of liquidus temperature (T{sub L}) measurements for the KT01-series glasses were mixed with regard to the predictability of the T{sub L} for each glass. All of the measured T{sub L} values were higher than the model predicted values, although most fell within the 95% confidence intervals. Overall, the results of this study show a reasonable ability to incorporate the anticipated SCIX streams into DWPF-type glass compositions with TiO{sub 2} concentrations of 4-5 wt % in glass.

  7. MST Filterability Tests

    SciTech Connect (OSTI)

    Poirier, M. R.; Burket, P. R.; Duignan, M. R.

    2015-03-12

    The Savannah River Site (SRS) is currently treating radioactive liquid waste with the Actinide Removal Process (ARP) and the Modular Caustic Side Solvent Extraction Unit (MCU). The low filter flux through the ARP has limited the rate at which radioactive liquid waste can be treated. Recent filter flux has averaged approximately 5 gallons per minute (gpm). Salt Batch 6 has had a lower processing rate and required frequent filter cleaning. Savannah River Remediation (SRR) has a desire to understand the causes of the low filter flux and to increase ARP/MCU throughput. In addition, at the time the testing started, SRR was assessing the impact of replacing the 0.1 micron filter with a 0.5 micron filter. This report describes testing of MST filterability to investigate the impact of filter pore size and MST particle size on filter flux and testing of filter enhancers to attempt to increase filter flux. The authors constructed a laboratory-scale crossflow filter apparatus with two crossflow filters operating in parallel. One filter was a 0.1 micron Mott sintered SS filter and the other was a 0.5 micron Mott sintered SS filter. The authors also constructed a dead-end filtration apparatus to conduct screening tests with potential filter aids and body feeds, referred to as filter enhancers. The original baseline for ARP was 5.6 M sodium salt solution with a free hydroxide concentration of approximately 1.7 M.3 ARP has been operating with a sodium concentration of approximately 6.4 M and a free hydroxide concentration of approximately 2.5 M. SRNL conducted tests varying the concentration of sodium and free hydroxide to determine whether those changes had a significant effect on filter flux. The feed slurries for the MST filterability tests were composed of simple salts (NaOH, NaNO2, and NaNO3) and MST (0.2 – 4.8 g/L). The feed slurry for the filter enhancer tests contained simulated salt batch 6 supernate, MST, and filter enhancers.

  8. Links - MST - UW Plasma Physics

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

    Links UW Madison Madison Symmetric Torus Links MST HomeGraduate Student InformationLinksTourControl and Auxiliary SystemsPhysics TopicsDeviceResearch MissionMST People mst logo CPLA Home Directory Publications Links Internal University of Wisconsin Physics Department Research funding includes support from: Department of Energy National Science Foundation Other Reversed Field Pinch Experiments around the world: RFX-mod in Padua, Italy Extrap-T2R in Stockhom, Sweden RELAX at Kyoto Institute of

  9. SELECTIVE REMOVAL OF STRONTIUM AND CESIUM FROM SIMULATED WASTE SOLUTION WITH TITANATE ION EXCHANGERS IN A FILTER CARTRIDGE CONFIGURATION

    SciTech Connect (OSTI)

    Oji, L.; Martin, K.; Hobbs, D.

    2011-05-26

    This report describes experimental results for the selective removal of strontium and cesium from simulated waste solutions using monosodium titanate (MST) and crystalline silicotitanate (CST)-laden filter cartridges. Four types of ion exchange cartridge media (CST and MST designed by both 3M and POROX{reg_sign}) were evaluated. In these proof-of-principle tests effective uptake of both Sr-85 and Cs-137 was observed. However, the experiments were not performed long enough to determine the saturation levels or breakthrough curve for each filter cartridge. POREX{reg_sign} MST cartridges, which by design were based on co-sintering of the active titanates with polyethylene particles, seem to perform as well as the 3M-designed MST cartridges (impregnated filter membrane design) in the uptake of strontium. At low salt simulant conditions (0.29 M Na{sup +}), the instantaneous decontamination factor (D{sub F}) for Sr-85 with the 3M-design MST cartridge measured 26, representing the removal of 96% of the Sr-85. On the other hand, the Sr-85 instantaneous D{sub F} with the POREX{reg_sign} design MST cartridge measured 40 or 98% removal of the Sr-85. Strontium removal with the 3M-design MST and CST cartridges placed in series filter arrangement produced an instantaneous decontamination factor of 41 or 97.6% removal compared to an instantaneous decontamination factor of 368 or 99.7% removal of the strontium with the POREX{reg_sign} MST and CST cartridge design placed in series. At high salt simulant conditions (5.6 M Na{sup +}), strontium removal with 3M-designed MST cartridge only and with 3M-designed MST and CST cartridges operated in a series configuration were identical. The instantaneous decontamination factor and the strontium removal efficiency, under the above configuration, averaged 8.6 and 88%, respectively. There were no POREX{reg_sign} cartridge experiments using the higher ionic strength simulant solution. At low salt simulant conditions, the uptake of Cs-137 with

  10. MST Ltd | Open Energy Information

    Open Energy Info (EERE)

    utility-scale PV power plants using concentrator technology (CPV), in the Israeli and Spanish markets. References: MST Ltd1 This article is a stub. You can help OpenEI by...

  11. SELECTIVE REMOVAL OF STRONTIUM AND CESIUM FROM SIMULATED WASTE SOLUTION WITH TITANATE ION-EXCHANGERS IN A FILTER CARTRIDGE CONFIGURATIONS-12092

    SciTech Connect (OSTI)

    Oji, L.; Martin, K.; Hobbs, D.

    2012-01-03

    Experimental results for the selective removal of strontium and cesium from simulated waste solutions with monosodium titanate and crystalline silicotitanate laden filter cartridges are presented. In these proof-of-principle tests, effective uptake of both strontium-85 and cesium-137 were observed using ion-exchangers in this filter cartridge configuration. At low salt simulant conditions, the instantaneous decontamination factor for strontium-85 with monosodium titanate impregnated filter membrane cartridges measured 26, representing 96% strontium-85 removal efficiency. On the other hand, the strontium-85 instantaneous decontamination factor with co-sintered active monosodium titanate cartridges measured 40 or 98% Sr-85 removal efficiency. Strontium-85 removal with the monosodium titanate impregnated membrane cartridges and crystalline silicotitanate impregnated membrane cartridges, placed in series arrangement, produced an instantaneous decontamination factor of 41 compared to an instantaneous decontamination factor of 368 for strontium-85 with co-sintered active monosodium titanate cartridges and co-sintered active crystalline silicotitanate cartridges placed in series. Overall, polyethylene co-sintered active titanates cartridges performed as well as titanate impregnated filter membrane cartridges in the uptake of strontium. At low ionic strength conditions, there was a significant uptake of cesium-137 with co-sintered crystalline silicotitanate cartridges. Tests results with crystalline silicotitanate impregnated membrane cartridges for cesium-137 decontamination are currently being re-evaluated. Based on these preliminary findings we conclude that incorporating monosodium titanate and crystalline silicotitanate sorbents into membranes represent a promising method for the semicontinuous removal of radioisotopes of strontium and cesium from nuclear waste solutions.

  12. Physics Topics - MST - UW Plasma Physics

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

    Physics Topics UW Madison Madison Symmetric Torus Physics Topics MST HomeGraduate Student InformationLinksTourControl and Auxiliary SystemsPhysics TopicsDeviceResearch MissionMST People mst logo CPLA Home Directory Publications Links Internal University of Wisconsin Physics Department Research funding includes support from: Department of Energy National Science Foundation The MST physics challenges are large and many, but much of our work is captured in the following four major RFP physics goals

  13. Research Mission - MST - UW Plasma Physics

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

    Research Mission UW Madison Madison Symmetric Torus Research Mission MST HomeGraduate Student InformationLinksTourControl and Auxiliary SystemsPhysics TopicsDeviceResearch MissionMST People mst logo CPLA Home Directory Publications Links Internal University of Wisconsin Physics Department Research funding includes support from: Department of Energy National Science Foundation Additional Information: Information for Prospective Graduate Students With the MST facility, physicists study hot plasmas

  14. MST e-News December 2015

    SciTech Connect (OSTI)

    Kippen, Karen Elizabeth

    2015-12-15

    This is the December 2015 issue of the MST e-News newsletter for the Materials Science and Technology Division.

  15. CX-007012: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Monosodium Titanate (MST) RheologyCX(s) Applied: B3.6Date: 09/09/2011Location(s): Aiken, South CarolinaOffice(s): Environmental Management, National Energy Technology Laboratory

  16. CX-009101: Categorical Exclusion Determination

    Broader source: Energy.gov [DOE]

    Monosodium Titanate (MST) Rheology CX(s) Applied: B3.6 Date: 08/30/2012 Location(s): South Carolina Offices(s): Savannah River Operations Office

  17. Graduate Student Information - MST - UW Plasma Physics

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

    Graduate Student Information UW Madison Madison Symmetric Torus Graduate Student Information MST HomeGraduate Student InformationLinksTourControl and Auxiliary SystemsPhysics TopicsDeviceResearch MissionMST People mst logo CPLA Home Directory Publications Links Internal University of Wisconsin Physics Department Research funding includes support from: Department of Energy National Science Foundation Opportunities: At any given time there are about a dozen graduate students doing experimental

  18. Topics: Determining the Beta Limit - MST - UW Plasma Physics

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

    Determining the Beta Limit UW Madison Madison Symmetric Torus Topics: Determining the Beta Limit MST HomeGraduate Student InformationLinksTourControl and Auxiliary SystemsPhysics TopicsDeviceResearch MissionMST People mst logo CPLA Home Directory Publications Links Internal University of Wisconsin Physics Department Research funding includes support from: Department of Energy National Science Foundation One of the reasons improved confinement in MST can be described as "tokamak-like"

  19. Control and Auxiliary Systems - MST - UW Plasma Physics

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

    Control and Auxiliary Systems UW Madison Madison Symmetric Torus Control and Auxiliary Systems MST HomeGraduate Student InformationLinksTourControl and Auxiliary SystemsPhysics TopicsDeviceResearch MissionMST People mst logo CPLA Home Directory Publications Links Internal University of Wisconsin Physics Department Research funding includes support from: Department of Energy National Science Foundation Control of the current density profile in MST has led to reduced magnetic fluctuations and

  20. Programmable Power Supply for MST'S Poloidal

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

    IEEEINPSS 24th Symposium on Fusion Engineering SP3-47 Programmable Power Supply for MST'S Poloidal Field D. J. Holly, J. R. Adney, K. J. McCollam, J. C. Morin, and M. A. Thomas University of Wisconsin Madison, WI 53706 Abstract- We are designing a new programmable polo ida I feld power supply for the MST reversed-feld pinch. By providing fexible waveform control, the new supply will expand capabilities in oscillating feld current drive, inductive current profle control, and other inductive

  1. Electron Bernstein Wave Studies in MST

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

    Bernstein Wave Studies in MST Andrew H. Seltzman, Jay K. Anderson, Paul D. Nonn, Jason X. Kauffold, Stephanie. J. Diem et al. Citation: AIP Conf. Proc. 1406, 485 (2011); doi: 10.1063/1.3665020 View online: http://dx.doi.org/10.1063/1.3665020 View Table of Contents: http://proceedings.aip.org/dbt/dbt.jsp?KEY=APCPCS&Volume=1406&Issue=1 Published by the American Institute of Physics. Additional information on AIP Conf. Proc. Journal Homepage: http://proceedings.aip.org/ Journal Information:

  2. The TITAN reversed-field-pinch fusion reactor study

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

    This report discusses the following topics: overview of titan-2 design; titan-2 fusion-power-core engineering; titan-2 divertor engineering; titan-2 tritium systems; titan-2 safety design and radioactive-waste disposal; and titan-2 maintenance procedures.

  3. MST e-News March 2016 (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Technical Report: MST e-News March 2016 Citation Details In-Document Search Title: MST e-News March 2016 You are accessing a document from the Department of Energy's (DOE) ...

  4. Assessment of performing an MST strike in Tank 21H

    SciTech Connect (OSTI)

    Poirier, Michael R.

    2014-09-29

    Previous Savannah River National Laboratory (SRNL) tank mixing studies performed for the Small Column Ion Exchange (SCIX) project have shown that 3 Submersible Mixer Pumps (SMPs) installed in Tank 41 are sufficient to support actinide removal by MST sorption as well as subsequent resuspension and removal of settled solids. Savannah River Remediation (SRR) is pursuing MST addition into Tank 21 as part of the Large Tank Strike (LTS) project. The preliminary scope for LTS involves the use of three standard slurry pumps (installed in N, SE, and SW risers) in a Type IV tank. Due to the differences in tank size, internal interferences, and pump design, a separate mixing evaluation is required to determine if the proposed configuration will allow for MST suspension and strontium and actinide sorption. The author performed the analysis by reviewing drawings for Tank 21 [W231023] and determining the required cleaning radius or zone of influence for the pumps. This requirement was compared with previous pilot-scale MST suspension data collected for SCIX that determined the cleaning radius, or zone of influence, as a function of pump operating parameters. The author also reviewed a previous Tank 50 mixing analysis that examined the ability of standard slurry pumps to suspend sludge particles. Based on a review of the pilot-scale SCIX mixing tests and Tank 50 pump operating experience, three standard slurry pumps should be able to suspend sludge and MST to effectively sorb strontium and actinides onto the MST. Using the SCIX data requires an assumption about the impact of cooling coils on slurry pump mixing. The basis for this assumption is described in this report. Using the Tank 50 operating experience shows three standard slurry pumps should be able to suspend solids if the shear strength of the settled solids is less than 160 Pa. Because Tank 21 does not contain cooling coils, the shear strength could be larger.

  5. Overview of results from the MST reversed field pinch experiment

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

    38 Please note that terms and conditions apply. Overview of results from the MST reversed field pinch experiment View the table of contents for this issue, or go to the journal homepage for more 2015 Nucl. Fusion 55 104006 (http://iopscience.iop.org/0029-5515/55/10/104006) Home Search Collections Journals About Contact us My IOPscience | International Atomic Energy Agency Nuclear Fusion Nucl. Fusion 55 (2015) 104006 (8pp) doi:10.1088/0029-5515/55/10/104006 Overview of results from the MST

  6. Crystalline titanate catalyst supports

    DOE Patents [OSTI]

    Anthony, Rayford G.; Dosch, Robert G.

    1993-01-01

    A series of new crystalline titanates (CT) are shown to have considerable potential as catalyst supports. For Pd supported catalyst, the catalytic activity for pyrene hydrogenation was substantially different depending on the type of CT, and one was substantially more active than Pd on hydrous titanium oxide (HTO). For 1-hexene hydrogenation the activities of the new CTs were approximately the same as for the hydrous metal oxide supports.

  7. Crystalline titanate catalyst supports

    DOE Patents [OSTI]

    Anthony, R.G.; Dosch, R.G.

    1993-01-05

    A series of new crystalline titanates (CT) are shown to have considerable potential as catalyst supports. For Pd supported catalyst, the catalytic activity for pyrene hydrogenation was substantially different depending on the type of CT, and one was substantially more active than Pd on hydrous titanium oxide (HTO). For 1-hexene hydrogenation the activities of the new CTs were approximately the same as for the hydrous metal oxide supports.

  8. Zinc titanate sorbents

    DOE Patents [OSTI]

    Gupta, R.P.; Gangwal, S.K.; Jain, S.C.

    1998-02-03

    The present invention provides a zinc titanate sorbent material useful in desulfurization applications. The zinc titanate material is in the form of generally spherical particles of substantially uniform chemical distribution. The sorbent material is capable of absorbing sulfur compounds from a gaseous feed in an amount of at least about 15 weight percent based on the weight of the sorbent. The sorbent material is prepared by a process including: (a) forming a zinc oxide/titanium dioxide dry blend, (b) preparing a substantially uniform aqueous slurry comprising the zinc oxide/titanium dioxide dry blend, organic binder, and at least about 1 weight percent inorganic binder based on the solids weight of the slurry, (c) spray drying the slurry to produce substantially spherical particles, and (d) calcining the particles at a temperature of between about 750 to about 950 C. The dry blend is formed by mixing between about 0.5 to about 2 parts zinc oxide having a median particle size of less than about 0.5 microns, and about 1 part titanium dioxide having a median particle size of less than about 1 micron. The slurry contains substantially no free silica and may be prepared by the process including (1) preparing an aqueous solution of organic binder, (2) adding the dry blend to the aqueous solution of organic binder, and (3) adding the inorganic binder to the solution of organic binder, and blend. Additional reagents, such as a surfactant, may also be incorporated into the sorbent material. The present invention also provides a process for desulfurizing a gaseous stream. The process includes passing a gaseous stream through a reactor containing an attrition resistant zinc titanate sorbent material of the present invention.

  9. Zinc titanate sorbents

    DOE Patents [OSTI]

    Gupta, Raghubir P.; Gangwal, Santosh K.; Jain, Suresh C.

    1998-01-01

    The present invention provides a zinc titanate sorbent material useful in desulfurization applications. The zinc titanate material is in the form of generally spherical particles of substantially uniform chemical distribution. The sorbent material is capable of absorbing sulfur compounds from a gaseous feed in an amount of at least about 15 weight percent based on the weight of the sorbent. The sorbent material is prepared by a process including: (a) forming a zinc oxide/titanium dioxide dry blend, (b) preparing a substantially uniform aqueous slurry comprising the zinc oxide/titanium dioxide dry blend, organic binder, and at least about 1 weight percent inorganic binder based on the solids weight of the slurry, (c) spray drying the slurry to produce substantially spherical particles, and (d) calcining the particles at a temperature of between about 750.degree. C. to about 950.degree. C. The dry blend is formed by mixing between about 0.5 to about 2 parts zinc oxide having a median particle size of less than about 0.5 .mu., and about 1 part titanium dioxide having a median particle size of less than about 1 .mu.. The slurry contains substantially no free silica and may be prepared by the process including (1) preparing an aqueous solution of organic binder, (2) adding the dry blend to the aqueous solution of organic binder, and (3) adding the inorganic binder to the solution of organic binder, and blend. Additional reagents, such as a surfactant, may also be incorporated into the sorbent material. The present invention also provides a process for desulfurizing a gaseous stream. The process includes passing a gaseous stream through a reactor containing an attrition resistant zinc titanate sorbent material of the present invention.

  10. New Titan Supercomputer Named Fastest in the World | Department...

    Office of Environmental Management (EM)

    Titan Supercomputer Named Fastest in the World New Titan Supercomputer Named Fastest in ... WASHINGTON - U.S. Secretary of Energy Steven Chu today announced that Titan, a new ...

  11. MST e-News September 2014 (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    National Laboratory (LANL) Sponsoring Org: DOELANL Country of Publication: United States Language: English Subject: Materials Science(36) LANL, MST e-News, Newsletter of the...

  12. The TITAN reversed-field-pinch fusion reactor study

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

    This report discusses research on the titan-1 fusion power core. The major topics covered are: titan-1 fusion-power-core engineering; titan-1 divertor engineering; titan-1 tritium systems; titan-1 safety design and radioactive-waste disposal; and titan-1 maintenance procedures.

  13. Port hole perturbations to the magnetic field in MST

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

    2 (2010) 095002 (17pp) doi:10.1088/0741-3335/52/9/095002 Port hole perturbations to the magnetic field in MST P J Fimognari 1 , A F Almagri 1 , J K Anderson 1 , D R Demers 2 , J S Sarff 1 , V Tangri 1 and J Waksman 1 1 Department of Physics, University of Wisconsin-Madison, Madison, WI 53706, USA 2 Rensselaer Polytechnic Institute, Troy, NY 12180, USA E-mail: fimognari@wisc.edu Received 26 February 2010, in final form 23 June 2010 Published 19 July 2010 Online at stacks.iop.org/PPCF/52/095002

  14. EES/CSES/MST Frontiers in Geoscience Colloquium

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

    EES/CSES/MST Frontiers in Geoscience Colloquium Monday, March 21, 2016 3:00pm - 4:00pm EES-DO Conference Room (TA-3, 215, 275) Plastic and elastic anisotropy in olivine: Understanding plate boundaries in the laboratory Prof. Lars Hansen Department of Earth Sciences, University of Oxford, UK Plate tectonics is clearly the largest scientific revolution in the Earth sciences. However, a key outstanding gap in our understanding of the solid earth is the manner in which tectonic plates can be

  15. Locked modes and magnetic field errors in MST

    SciTech Connect (OSTI)

    Almagri, A.F.; Assadi, S.; Prager, S.C.; Sarff, J.S.; Kerst, D.W.

    1992-06-01

    In the MST reversed field pinch magnetic oscillations become stationary (locked) in the lab frame as a result of a process involving interactions between the modes, sawteeth, and field errors. Several helical modes become phase locked to each other to form a rotating localized disturbance, the disturbance locks to an impulsive field error generated at a sawtooth crash, the error fields grow monotonically after locking (perhaps due to an unstable interaction between the modes and field error), and over the tens of milliseconds of growth confinement degrades and the discharge eventually terminates. Field error control has been partially successful in eliminating locking.

  16. Structural basis of the heterodimerization of the MST and RASSF SARAH domains in the Hippo signalling pathway

    SciTech Connect (OSTI)

    Hwang, Eunha; Cheong, Hae-Kap; Mushtaq, Ameeq Ul; Kim, Hye-Yeon; Yeo, Kwon Joo; Kim, Eunhee; Lee, Woo Cheol; Hwang, Kwang Yeon; Cheong, Chaejoon; Jeon, Young Ho

    2014-07-01

    The heterodimeric structure of the MST1 and RASSF5 SARAH domains is presented. A comparison of homodimeric and heterodimeric interactions provides a structural basis for the preferential association of the SARAH heterodimer. Despite recent progress in research on the Hippo signalling pathway, the structural information available in this area is extremely limited. Intriguingly, the homodimeric and heterodimeric interactions of mammalian sterile 20-like (MST) kinases through the so-called ‘SARAH’ (SAV/RASSF/HPO) domains play a critical role in cellular homeostasis, dictating the fate of the cell regarding cell proliferation or apoptosis. To understand the mechanism of the heterodimerization of SARAH domains, the three-dimensional structures of an MST1–RASSF5 SARAH heterodimer and an MST2 SARAH homodimer were determined by X-ray crystallography and were analysed together with that previously determined for the MST1 SARAH homodimer. While the structure of the MST2 homodimer resembled that of the MST1 homodimer, the MST1–RASSF5 heterodimer showed distinct structural features. Firstly, the six N-terminal residues (Asp432–Lys437), which correspond to the short N-terminal 3{sub 10}-helix h1 kinked from the h2 helix in the MST1 homodimer, were disordered. Furthermore, the MST1 SARAH domain in the MST1–RASSF5 complex showed a longer helical structure (Ser438–Lys480) than that in the MST1 homodimer (Val441–Lys480). Moreover, extensive polar and nonpolar contacts in the MST1–RASSF5 SARAH domain were identified which strengthen the interactions in the heterodimer in comparison to the interactions in the homodimer. Denaturation experiments performed using urea also indicated that the MST–RASSF heterodimers are substantially more stable than the MST homodimers. These findings provide structural insights into the role of the MST1–RASSF5 SARAH domain in apoptosis signalling.

  17. Silico-titanates and their methods of making and using

    DOE Patents [OSTI]

    Anthony, Rayford G.; Dosch, Robert G.; Philip, C. V.

    2002-01-01

    Noval silico-titanates and the methods of making and using the said titanates are disclosed. Nb-doped silico-titanates are particularly useful for selectively removing cesuim from radioactive wastes.

  18. MST e-News March 2016 (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: MST e-News March 2016 March 2016 newsletter of the Materials Science and Technology Division of Los Alamos National Laboratory. Authors: ...

  19. Sandia National Laboratories: Remember the TITANS

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

    Remember the TITANS Facebook Twitter YouTube Flickr RSS News Remember the TITANS Photography By Nick Kerekes Thursday, September 01, 2016 TITANS (Technical Internships to Advance National Security) University Days is an annual event that supports research and recruiting partnerships with Sandia's Academic Alliance/Campus Executive schools, the Minority Serving Institutions Partnership Program, and other universities across the country. About 20 faculty members participated in this year's event,

  20. China Titans Energy Technology Group Co Ltd | Open Energy Information

    Open Energy Info (EERE)

    Titans Energy Technology Group Co Ltd Jump to: navigation, search Name: China Titans Energy Technology Group Co Ltd Place: Zhuhai, Guangdong Province, China Sector: Solar,...

  1. Delaminated titanate and peroxotitanate photocatalysts. (Journal...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Delaminated titanate and peroxotitanate photocatalysts. Citation Details In-Document Search ... Publication Date: 2011-04-01 OSTI Identifier: 1108346 Report ...

  2. Titan Omsk Group | Open Energy Information

    Open Energy Info (EERE)

    Name: Titan Omsk Group Place: Omsk, Russian Federation Product: One of Russia's top chemical companies with a subsidiary, Silarus, which is planning on building a polysilicon...

  3. Turbulent transport in the MST reversed-field pinch

    SciTech Connect (OSTI)

    Rempel, T.D.; Almagri, A.F.; Assadi, S.; Den Hartog, D.J.; Hokin, S.A.; Prager, S.C.; Sarff, J.S.; Shen, W.; Sidikman, K.L.; Spragins, C.W.; Sprott, J.C.; Stoneking, M.R.; Zita, E.J.

    1991-11-01

    Measurements of edge turbulence and the associated transport are ongoing in the Madison Symmetric Torus (R = 1.5 m, a = 0.52 m) reversed-field pinch using magnetic and electrostatic probes. Magnetic fluctuations are dominated by m = 1 and n {approximately} 2R/a tearing modes. Particle losses induced by magnetic field fluctuations have been found to be ambipolar (<{tilde J}{sub parallel}{tilde B}{sub r}> = O). Electrostatic fluctuations are broadband and turbulent, with mode widths {delta}m {approximately} 3--7 and {delta}n {approximately}70--150. Particle, parallel current, and energy transport arising from coherent motion with the fluctuating {tilde E}xB drift has been measured. Particle transport via this channel is comparable to the total particle loss from MST. Energy transport (from <{tilde P}{tilde E}{sub phi}>/B{sub o}) due to electrostatic fluctuations is relatively small, and parallel current transport (from <{tilde J}{sub parallel}{tilde E}{sub chi}>/B{sub o}) may be small as well.

  4. Hydrogen diffusion in Lead Zirconate Titanate and Barium Titanate

    SciTech Connect (OSTI)

    Alvine, Kyle J.; Vijayakumar, M.; Bowden, Mark E.; Schemer-Kohrn, Alan L.; Pitman, Stan G.

    2012-08-28

    Hydrogen is a potential clean-burning, next-generation fuel for vehicle and stationary power. Unfortunately, hydrogen is also well known to have serious materials compatibility issues in metals, polymers, and ceramics. Piezoelectric actuator materials proposed for low-cost, high efficiency high-pressure hydrogen internal combustion engines (HICE) are known to degrade rapidly in hydrogen. This limits their potential use and poses challenges for HICE. Hydrogen-induced degradation of piezoelectrics is also an issue for low-pressure hydrogen passivation in ferroelectric random access memory. Currently, there is a lack of data in the literature on hydrogen species diffusion in piezoelectrics in the temperature range appropriate for the HICE as charged via a gaseous route. We present 1HNMR quantification of the local hydrogen species diffusion within lead zirconate titanate and barium titanate on samples charged by exposure to high-pressure gaseous hydrogen ?32?MPa. Results are discussed in context of theoretically predicted interstitial hydrogen lattice sites and aqueous charging experiments from existing literature.

  5. MHD simulation of RF current drive in MST

    SciTech Connect (OSTI)

    Hendries, E. R.; Anderson, J. K.; Forest, C. B.; Reusch, J. A.; Seltzman, A. H.; Sovinec, C. R.; Diem, S.; Harvey, R. W.

    2014-02-12

    Auxiliary heating and current drive using RF waves such as the electron Bernstein wave (EBW) promises to advance the performance of the reversed field pinch (RFP). In previous computational work [1], a hypothetical edge-localized current drive is shown to suppress the tearing activity which governs the macroscopic transport properties of the RFP. The ideal conditions for tearing stabilization include a reduced toroidal induction, and precise width and radial position of the Gaussian-shaped external current drive. In support of the EBW experiment on the Madison Symmetric Torus, an integrated modeling scheme now incorporates ray tracing and Fokker-Plank predictions of auxiliary current into single fluid MHD. Simulations at low Lundquist number (S ∼ 10{sup 4}) generally agree with the previous work; significantly more burdensome simulations at MST-like Lundquist number (S ∼ 3×10{sup 6}) show unexpected results. The effect on nonlinearly saturated current profile by a particular RF-driven external force decreases in magnitude and widens considerably as the Lundquist number increases toward experimental values. Simulations reproduce the periodic current profile relaxation events observed in experiment (sawteeth) in the absence of current profile control. Reduction of the tearing mode amplitudes is still observable; however, reduction is limited to periods between the large bursts of magnetic activity at each sawtooth. The sawtoothing pattern persists with up to 10 MW of externally applied RF power. Periods with prolonged low tearing amplitude are predicted with a combination of external current drive and a reduced toroidal loop voltage, consistent with previous conclusions. Finally, the resistivity profile is observed to have a strong effect on the optimal externally driven current profile for mode stabilization.

  6. Plasma Flow in MST: Effects of Edge Biasing and Momentum Transport

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

    Flow in MST: Effects of Edge Biasing and Momentum Transport from Nonlinear Magnetic Torques J.S. Sarff, A.F. Almagri, J.K. Anderson, B.E. Chapman, D. Craig, C-S. Chiang, N.A. Crocker, D.J. Den Hartog, G. Fiksel, A.K. Hansen, and S.C. Prager Physics Department, University of Wisconsin Madison, Wisconsin, 53706 U.S.A Edge biasing in MST plasmas decreases electrostatic turbulent particle transport and increases the global particle confinement time. New Langmuir probe measurements in the edge

  7. Accelerated Application Development: The ORNL Titan Experience

    SciTech Connect (OSTI)

    Joubert, Wayne; Archibald, Richard K.; Berrill, Mark A.; Brown, W. Michael; Eisenbach, Markus; Grout, Ray; Larkin, Jeff; Levesque, John; Messer, Bronson; Norman, Matthew R.; Philip, Bobby; Sankaran, Ramanan; Tharrington, Arnold N.; Turner, John A.

    2015-05-09

    The use of computational accelerators such as NVIDIA GPUs and Intel Xeon Phi processors is now widespread in the high performance computing community, with many applications delivering impressive performance gains. However, programming these systems for high performance, performance portability and software maintainability has been a challenge. In this paper we discuss experiences porting applications to the Titan system. Titan, which began planning in 2009 and was deployed for general use in 2013, was the first multi-petaflop system based on accelerator hardware. To ready applications for accelerated computing, a preparedness effort was undertaken prior to delivery of Titan. In this paper we report experiences and lessons learned from this process and describe how users are currently making use of computational accelerators on Titan.

  8. Accelerated Application Development: The ORNL Titan Experience

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

    Joubert, Wayne; Archibald, Richard K.; Berrill, Mark A.; Brown, W. Michael; Eisenbach, Markus; Grout, Ray; Larkin, Jeff; Levesque, John; Messer, Bronson; Norman, Matthew R.; et al

    2015-05-09

    The use of computational accelerators such as NVIDIA GPUs and Intel Xeon Phi processors is now widespread in the high performance computing community, with many applications delivering impressive performance gains. However, programming these systems for high performance, performance portability and software maintainability has been a challenge. In this paper we discuss experiences porting applications to the Titan system. Titan, which began planning in 2009 and was deployed for general use in 2013, was the first multi-petaflop system based on accelerator hardware. To ready applications for accelerated computing, a preparedness effort was undertaken prior to delivery of Titan. In this papermore » we report experiences and lessons learned from this process and describe how users are currently making use of computational accelerators on Titan.« less

  9. PHLPP1 regulates contact inhibition by dephosphorylating Mst1 at the inhibitory site

    SciTech Connect (OSTI)

    Jung, Sujin; Kang, Jeong Gu; Lee, Ju Hee; Song, Kyoung Jin; Ko, Jeong-Heon; Kim, Yong-Sam

    2014-01-24

    Highlights: • PHLPP1 regulates contact inhibition by dephosphorylating Mst1 at Thr{sup 387}. • Overexpression of PHLPP1 sensitizes contact inhibition. • Tumor cells with suppressed PHLPP1 expression are refractory to apoptosis and highly proliferative. • Loss or down-regulation of PHLPP1 may drive tumor development and progression. - Abstract: Contact inhibition has been largely elusive despite that a loss of contact inhibition is a critical event for cancer development and progression. Here, we report that PHLPP1 is a binding protein for Mst1 and it modulates the Hippo pathway by dephosphorylating Mst1 at the inhibitory Thr{sup 387} of Mst1. Yap1 was localized predominantly in the nucleus but marginally in the cytoplasm in HeLa cells under sparse conditions, whereas the functional protein was more directed to sequestration in the cytoplasm under dense environments. Furthermore, loss of PHLPP1 resulted in a failure of the apoptotic control. It is interesting that down-regulated expression of PHLPP1 appears to mimic the loss of contact inhibition, a hallmark of cancer.

  10. TITAN'S TRANSPORT-DRIVEN METHANE CYCLE

    SciTech Connect (OSTI)

    Mitchell, Jonathan L.

    2012-09-10

    The mechanisms behind the occurrence of large cloud outbursts and precipitation on Titan have been disputed. A global- and annual-mean estimate of surface fluxes indicated only 1% of the insolation, or {approx}0.04 W m{sup -2}, is exchanged as sensible and/or latent fluxes. Since these fluxes are responsible for driving atmospheric convection, it has been argued that moist convection should be quite rare and precipitation even rarer, even if evaporation globally dominates the surface-atmosphere energy exchange. In contrast, climate simulations indicate substantial cloud formation and/or precipitation. We argue that the top-of-atmosphere (TOA) radiative imbalance is diagnostic of horizontal heat transport by Titan's atmosphere, and thus constrains the strength of the methane cycle. Simple calculations show the TOA radiative imbalance is {approx}0.5-1 W m{sup -2} in Titan's equatorial region, which implies 2-3 MW of latitudinal heat transport by the atmosphere. Our simulation of Titan's climate suggests this transport may occur primarily as latent heat, with net evaporation at the equator and net accumulation at higher latitudes. Thus, the methane cycle could be 10-20 times previous estimates. Opposing seasonal transport at solstices, compensation by sensible heat transport, and focusing of precipitation by large-scale dynamics could further enhance the local, instantaneous strength of Titan's methane cycle by a factor of several. A limited supply of surface liquids in regions of large surface radiative imbalance may throttle the methane cycle, and if so, we predict more frequent large storms over the lakes district during Titan's northern summer.

  11. A green synthesis of a layered titanate, potassium lithium titanate; lower temperature solid-state reaction and improved materials performance

    SciTech Connect (OSTI)

    Ogawa, Makoto; Morita, Masashi; Igarashi, Shota; Sato, Soh

    2013-10-15

    A layered titanate, potassium lithium titanate, with the size range from 0.1 to 30 m was prepared to show the effects of the particle size on the materials performance. The potassium lithium titanate was prepared by solid-state reaction as reported previously, where the reaction temperature was varied. The reported temperature for the titanate preparation was higher than 800 C, though 600 C is good enough to obtain single-phase potassium lithium titanate. The lower temperature synthesis is cost effective and the product exhibit better performance as photocatalysts due to surface reactivity. - Graphical abstract: Finite particle of a layered titanate, potassium lithium titanate, was prepared by solid-state reaction at lower temperature to show modified materials performance. Display Omitted - Highlights: Potassium lithium titanate was prepared by solid-state reaction. Lower temperature reaction resulted in smaller sized particles of titanate. 600 C was good enough to obtain single phased potassium lithium titanate. The product exhibited better performance as photocatalyst.

  12. RESULTS OF ANALYSES OF MACROBATCH 3 DECONTAMINATED SALT SOLUTION (DSS) COALESCER AND PRE-FILTERS

    SciTech Connect (OSTI)

    Peters, T.; Fondeur, F.; Fink, S.

    2012-06-13

    SRNL analyzed the pre-filter and Decontamination Salt Solution (DSS) coalescer from MCU by several analytical methods. The results of these analyses indicate that overall there is light to moderate solids fouling of both the coalescer and pre-filter elements. The majority of the solids contain aluminum, sodium, silicon, and titanium, in oxide and/or hydroxide forms that we have noted before. The titanium is presumably precipitated from leached, dissolved monosodium titanate (MST) or fines from MST at ARP, and the quantity we find is significantly greater than in the past. A parallel report discusses potential causes for the increased leaching rate of MST, showing that increases in free hydroxide concentration of the feed solutions and of chemical cleaning solutions lead to faster leaching of titanium.

  13. Sandia National Laboratories: TITANS - Technical Internships to Advance

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

    National Security Facebook Twitter YouTube Flickr RSS TITANS - Technical Internships to Advance National Security Gain comprehensive national security experience Hands-on rotational opportunities with high-caliber technical mentors About TITANS Technical Internships to Advance National Security (TITANS) is an innovative Sandia program that allows you to choose a focused, stimulating internship experience in one of three technical tracks: Center for Analysis Systems and Applications (CASA) -

  14. Flipping the switch on magnetism in strontium titanate

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

    Flipping the switch on magnetism in strontium titanate Flipping the switch on magnetism in strontium titanate Researchers have found a way to magnetize this material using light, an effect that persists for hours at a time. March 27, 2014 Los Alamos postdoctoral fellow William Rice holds a crystal of strontium titanate up to the light. This crystal, previously thought to be nonmagnetic, turns out to have surprising magnetic features when treated with special "circularly polarized"

  15. Fatigue of extracted lead zirconate titanate multilayer actuators...

    Office of Scientific and Technical Information (OSTI)

    Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses ...

  16. Titan Energy Systems Enfinity JV | Open Energy Information

    Open Energy Info (EERE)

    Systems & Enfinity JV Place: Andhra Pradesh, India Sector: Solar Product: India-based joint venture to develop solar PV projects. References: Titan Energy Systems & Enfinity...

  17. New Titan Supercomputer Named Fastest in the World | Department...

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

    This morning the "TOP500" list of the world's fastest supercomputers named Titan, a new ... the atmosphere at new levels to help researchers better understand future air quality. ...

  18. Progress at the TITAN-EBIT

    SciTech Connect (OSTI)

    Klawitter, R.; Alanssari, M.; Frekers, D.; Chowdhury, U.; Gwinner, G.; Chaudhuri, A.; Grossheim, A.; Kwiatkowski, A. A.; Leach, K.; Schultz, B. E.; Dilling, J.; Lpez-Urrutia, J. R. Crespo; Ettenauer, S.; Gallant, A. T.; Macdonald, T. D.; Lennarz, A.; Simon, M. C.; Seeraji, S.; Andreoiu, C.

    2015-01-09

    Precision mass measurements of short-lived isotopes provide insight into a wide array of physics, including nuclear structure, nucleosynthesis, and tests of the Standard Model. The precision of Penning trap mass spectrometry (PTMS) measurements is limited by the lifetime of the isotopes of interest, but scales proportionally with their charge state q, making highly charged ions attractive for mass measurements of nuclides far from stability. TITAN, TRIUMF's Ion Trap(s) for Atomic and Nuclear science, is currently the only setup in the world coupling an EBIT to a rare isotope facility for the purpose of PTMS. Charge breeding ions for Penning trap mass spectrometry, however, entails specific set of challenges. To make use of its potential, efficiencies have to be high, breeding times have to be short and the ion energy spread has to be small. An overview of the TITAN facility and charge-breeding program is given, current and future developments are highlighted and some selected results are presented.

  19. DETECTION OF PROPENE IN TITAN'S STRATOSPHERE

    SciTech Connect (OSTI)

    Nixon, C. A.; Flasar, F. M.; Jennings, D. E.; Bézard, B.; Vinatier, S.; Coustenis, A.; Teanby, N. A.; Sung, K.; Ansty, T. M.; Irwin, P. G. J.; Gorius, N.; Cottini, V.

    2013-10-10

    The Voyager 1 flyby of Titan in 1980 gave a first glimpse of the chemical complexity of Titan's atmosphere, detecting many new molecules with the infrared interferometer spectrometer (IRIS). These included propane (C{sub 3}H{sub 8}) and propyne (CH{sub 3}C{sub 2}H), while the intermediate-sized C{sub 3}H {sub x} hydrocarbon (C{sub 3}H{sub 6}) was curiously absent. Using spectra from the Composite Infrared Spectrometer on Cassini, we show the first positive detection of propene (C{sub 3}H{sub 6}) in Titan's stratosphere (5σ significance), finally filling the three-decade gap in the chemical sequence. We retrieve a vertical abundance profile from 100-250 km, that varies slowly with altitude from 2.0 ± 0.8 ppbv at 125 km, to 4.6 ± 1.5 ppbv at 200 km. The abundance of C{sub 3}H{sub 6} is less than both C{sub 3}H{sub 8} and CH{sub 3}C{sub 2}H, and we remark on an emerging paradigm in Titan's hydrocarbon abundances whereby alkanes > alkynes > alkenes within the C{sub 2}H {sub x} and C{sub 3}H {sub x} chemical families in the lower stratosphere. More generally, there appears to be much greater ubiquity and relative abundance of triple-bonded species than double-bonded, likely due to the greater resistance of triple bonds to photolysis and chemical attack.

  20. Plasma Velocity Profile During The Pulsed Poloidal Current Drive In The MST RFP Plasma

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

    Velocity Profile During The Pulsed Poloidal Current Drive In The MST RFP Plasma H. Sakakita 1,2 , D. Craig 2 , J. K. Anderson 2 , T. M. Biewer 2 , S. D. Terry 3 , B. E. Chapman 2 and D. J. Den-Hartog 2 1 Energy Electronics Institute, National Institute of A. I. S. T., Tsukuba, JAPAN 2 Department of Physics, University of Wisconsin, Madison, USA 3 Department of Electrical Engineering, University of California, Los Angels, USA Abstract. We report on the plasma velocity profile measurements during

  1. An integrated data analysis tool for improving measurements on the MST RFPa)

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

    integrated data analysis tool for improving measurements on the MST RFP a) a) Contributed paper, published as part of the Proceedings of the 20th Topical Conference on High- Temperature Plasma Diagnostics, Atlanta, Georgia, USA, June 2014. L. M. Reusch 1,b) , M. E. Galante 1 , P. Franz 2 , J. R. Johnson 1 , M. B. McGarry 1 , H. D. Stephens 1,3 and D. J. Den Hartog 1 b) Electronic mail: lmmcguire@wisc.edu Rev. Sci. Instrum. 85, 11D844 (2014); http://dx.doi.org/10.1063/1.4886957 Abstract Many

  2. Improved-confinement plasmas at high temperature and high beta in the MST RFP

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

    Improved-confinement plasmas at high temperature and high beta in the MST RFP This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2009 Nucl. Fusion 49 104020 (http://iopscience.iop.org/0029-5515/49/10/104020) Download details: IP Address: 128.104.166.214 The article was downloaded on 14/10/2010 at 00:22 Please note that terms and conditions apply. View the table of contents for this issue, or go to the journal homepage for more Home Search

  3. Internal magnetic field structure and parallel electric field profile evolution during the sawtooth cycle in MST

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

    magnetic field structure and parallel electric field profile evolution during the sawtooth cycle in MST This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2008 Plasma Phys. Control. Fusion 50 115013 (http://iopscience.iop.org/0741-3335/50/11/115013) Download details: IP Address: 128.104.166.214 The article was downloaded on 13/10/2010 at 22:35 Please note that terms and conditions apply. View the table of contents for this issue, or go to the

  4. CHARACTERIZATION OF CLOUDS IN TITAN'S TROPICAL ATMOSPHERE

    SciTech Connect (OSTI)

    Griffith, Caitlin A.; Penteado, Paulo; Rodriguez, Sebastien; Baines, Kevin H.; Buratti, Bonnie; Sotin, Christophe; Clark, Roger; Nicholson, Phil; Jaumann, Ralf

    2009-09-10

    Images of Titan's clouds, possible over the past 10 years, indicate primarily discrete convective methane clouds near the south and north poles and an immense stratiform cloud, likely composed of ethane, around the north pole. Here we present spectral images from Cassini's Visual Mapping Infrared Spectrometer that reveal the increasing presence of clouds in Titan's tropical atmosphere. Radiative transfer analyses indicate similarities between summer polar and tropical methane clouds. Like their southern counterparts, tropical clouds consist of particles exceeding 5 {mu}m. They display discrete structures suggestive of convective cumuli. They prevail at a specific latitude band between 8 deg. - 20 deg. S, indicative of a circulation origin and the beginning of a circulation turnover. Yet, unlike the high latitude clouds that often reach 45 km altitude, these discrete tropical clouds, so far, remain capped to altitudes below 26 km. Such low convective clouds are consistent with the highly stable atmospheric conditions measured at the Huygens landing site. Their characteristics suggest that Titan's tropical atmosphere has a dry climate unlike the south polar atmosphere, and despite the numerous washes that carve the tropical landscape.

  5. Solid target boronization of the MST reversed-field pinch during pulsed discharge cleaning

    SciTech Connect (OSTI)

    Den Hartog, D.J.; Kendrick, R.D.

    1994-06-01

    A solid rod of hot-pressed boron carbide is currently being used as the source of boron during boronization of MST. In previous work the authors have demonstrated that boronization can be effectively accomplished by insertion of a low apparent density B{sub 4}C rod into the edge hydrogen plasma of normal high-power RFP discharges. The authors have now extended that technique and can boronize MST by inserting a negatively biased B{sub 4}C rod into pulsed discharge cleaning (PDC) helium plasmas. The same positive results of reduced impurity contamination and particle reflux are achieved with this new boronization method. The bias for the target is provided by the ohmic heating transformer which is pulsed to produce the PDC discharges. Current flow through the B{sub 4}C rod is limited by an inductor. The amount of hydrogen in the amorphous boron carbide films is minimal because the only hydrogen in the PDC plasma is that left over from RFP discharges.

  6. MST 1: Proceedings of a conference on the integration of mathematics, science and technology in precollege education

    SciTech Connect (OSTI)

    Swyler, K.

    1995-11-01

    Example MST activities examined here show: (1) an inquiry-driven learning stimulus, involving (2) the synthesis of concepts in math, science and technology, through (3) the application of the scientific method and engineering problem solving/test protocols, and provoking (4) a stimulus for further exploration. A semi-exploratory learning approach offered background aimed at enabling participants to take meaningful courses of investigation; this approach must be balanced by maintaining contact with framework content standards. On the whole, the philosophy underlying the MST learning approach--as envisioned in the draft NYS Framework, and embodied in the example activities--is strongly endorsed. This endorsement is broad-based: those represented include teachers of mathematics, science, and technology, and school district administrators--in roughly equal numbers. Discussion centers not on whether the MST approach should be pursued, but on what is involved in doing it. Teams of conference participants were given time to plan or extend MST initiatives in their own districts. Outlines of the initiatives proposed by ten of the teams are disseminated herein.

  7. Polar state in freestanding strontium titanate nanoparticles

    SciTech Connect (OSTI)

    Tyson, Trevor A. E-mail: sswong@bnl.gov Yu, Tian; Croft, Mark; Scofield, Megan E.; Bobb-Semple, Dara; Tao, Jing; Jaye, Cherno; Fischer, Daniel; Wong, Stanislaus S. E-mail: sswong@bnl.gov

    2014-09-01

    Monodispersed strontium titanate nanoparticles were prepared and studied in detail. It is found that ?10?nm as-prepared stoichiometric nanoparticles are in a polar structural state (possibly with ferroelectric properties) over a broad temperature range. A tetragonal structure, with possible reduction of the electronic hybridization, is found as the particle size is reduced. In the 10?nm particles, no change in the local Ti-off centering is seen between 20 and 300?K. The results indicate that nanoscale motifs of SrTiO{sub 3} may be utilized in data storage as assembled nano-particle arrays in applications where chemical stability, temperature stability, and low toxicity are critical issues.

  8. Scalable k-means statistics with Titan.

    SciTech Connect (OSTI)

    Thompson, David C.; Bennett, Janine C.; Pebay, Philippe Pierre

    2009-11-01

    This report summarizes existing statistical engines in VTK/Titan and presents both the serial and parallel k-means statistics engines. It is a sequel to [PT08], [BPRT09], and [PT09] which studied the parallel descriptive, correlative, multi-correlative, principal component analysis, and contingency engines. The ease of use of the new parallel k-means engine is illustrated by the means of C++ code snippets and algorithm verification is provided. This report justifies the design of the statistics engines with parallel scalability in mind, and provides scalability and speed-up analysis results for the k-means engine.

  9. METHANE GAS STABILIZES SUPERCOOLED ETHANE DROPLETS IN TITAN'S CLOUDS

    SciTech Connect (OSTI)

    Wang, Chia C.; Lang, E. Kathrin; Signorell, Ruth

    2010-03-20

    Strong evidence for ethane clouds in various regions of Titan's atmosphere has recently been found. Ethane is usually assumed to exist as ice particles in these clouds, although the possible role of liquid and supercooled liquid ethane droplets has been recognized. Here, we report on infrared spectroscopic measurements of ethane aerosols performed in the laboratory under conditions mimicking Titan's lower atmosphere. The results clearly show that liquid ethane droplets are significantly stabilized by methane gas which is ubiquitous in Titan's nitrogen atmosphere-a phenomenon that does not have a counterpart for water droplets in Earth's atmosphere. Our data imply that supercooled ethane droplets are much more abundant in Titan's clouds than previously anticipated. Possibly, these liquid droplets are even more important for cloud processes and the formation of lakes than ethane ice particles.

  10. PROTOSOLAR AMMONIA AS THE UNIQUE SOURCE OF TITAN's NITROGEN

    SciTech Connect (OSTI)

    Mandt, Kathleen E.; Mousis, Olivier; Gautier, Daniel

    2014-06-20

    The origin of Titan's nitrogen-rich atmosphere is thought to be ammonia ice, but this has not yet been confirmed. Furthermore, it is uncertain whether the building blocks of Titan formed within the Saturnian subnebula or in the colder protosolar nebula (PSN). Recent measurements of the nitrogen isotope ratio in cometary ammonia, combined with evolutionary constraints on the nitrogen isotopes in Titan's atmosphere provide firm evidence that the nitrogen in Titan's atmosphere must have originated as ammonia ice formed in the PSN under conditions similar to that of cometary formation. This result has important implications for the projected D/H ratio in cometary methane, nitrogen isotopic fractionation in the PSN and the source of nitrogen for Earth's atmosphere.

  11. The TITAN reversed-field-pinch fusion reactor study

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

    This paper on titan plasma engineering contains papers on the following topics: reversed-field pinch as a fusion reactor; parametric systems studies; magnetics; burning-plasma simulations; plasma transient operations; current drive; and physics issues for compact RFP reactors.

  12. The TITAN Reversed-Field Pinch fusion reactor study

    SciTech Connect (OSTI)

    Not Available

    1988-03-01

    The TITAN Reversed-Field Pinch (RFP) fusion reactor study is a multi-institutional research effort to determine the technical feasibility and key developmental issues of an RFP fusion reactor, especially at high power density, and to determine the potential economics, operations, safety, and environmental features of high-mass-power-density fusion systems. The TITAN conceptual designs are DT burning, 1000 MWe power reactors based on the RFP confinement concept. The designs are compact, have a high neutron wall loading of 18 MW/m{sup 2} and a mass power density of 700 kWe/tonne. The inherent characteristics of the RFP confinement concept make fusion reactors with such a high mass power density possible. Two different detailed designs have emerged: the TITAN-I lithium-vanadium design, incorporating the integrated-blanket-coil concept; and the TITAN-II aqueous loop-in-pool design with ferritic steel structure. This report contains a collection of 16 papers on the results of the TITAN study which were presented at the International Symposium on Fusion Nuclear Technology. This collection describes the TITAN research effort, and specifically the TITAN-I and TITAN-II designs, summarizing the major results, the key technical issues, and the central conclusions and recommendations. Overall, the basic conclusions are that high-mass power-density fusion reactors appear to be technically feasible even with neutron wall loadings up to 20 MW/m{sup 2}; that single-piece maintenance of the FPC is possible and advantageous; that the economics of the reactor is enhanced by its compactness; and the safety and environmental features need not to be sacrificed in high-power-density designs. The fact that two design approaches have emerged, and others may also be possible, in some sense indicates the robustness of the general findings.

  13. DE-FG02-05ER64001 Overcoming the hurdles of multi-step targeting (MST) for effective radioimmunotherapy of solid tumors

    SciTech Connect (OSTI)

    P.I. Steven M. Larson MD Co P.I. Nai-Kong Cheung MD, Ph.D.

    2009-09-21

    The 4 specific aims of this project are: (1) Optimization of MST to increase tumor uptake; (2) Antigen heterogeneity; (3) Characterization and reduction of renal uptake; and (4) Validation in vivo of optimized MST targeted therapy. This proposal focussed upon optimizing multistep immune targeting strategies for the treatment of cancer. Two multi-step targeting constructs were explored during this funding period: (1) anti-Tag-72 and (2) anti-GD2.

  14. DISCOVERY OF FOG AT THE SOUTH POLE OF TITAN

    SciTech Connect (OSTI)

    Brown, M. E.; Smith, A. L.; Chen, C.; Adamkovics, M.

    2009-11-20

    While Saturn's moon Titan appears to support an active methane hydrological cycle, no direct evidence for surface-atmosphere exchange has yet appeared. The indirect evidence, while compelling, could be misleading. It is possible, for example, that the identified lake features could be filled with ethane, an involatile long-term residue of atmospheric photolysis; the apparent stream and channel features could be ancient remnants of a previous climate; and the tropospheric methane clouds, while frequent, could cause no rain to reach the surface. We report here the detection of fog at the south pole of Titan during late summer using observations from the VIMS instrument on board the Cassini spacecraft. While terrestrial fog can form from a variety of causes, most of these processes are inoperable on Titan. Fog on Titan can only be caused by evaporation of nearly pure liquid methane; the detection of fog provides the first direct link between surface and atmospheric methane. Based on the detections presented here, liquid methane appears widespread at the south pole of Titan in late southern summer, and the hydrological cycle on Titan is currently active.

  15. Identification And Characterization Of The Solids Found In Extraction Contactor SEP-401 In June 2012

    SciTech Connect (OSTI)

    Fondeur, F. F.; Fink, S. D.

    2012-12-10

    The Modular Caustic-Side Solvent Extraction Unit (MCU) recently conducted an outage that included maintenance on the centrifugal contactors. Operations personnel observed solids or deposits in two contactors and attempted to collect samples for analyses by Savannah River National Laboratory (SRNL). The residues found in Extraction Contactor SEP-401 are a mixture of amorphous silica, aluminosilicate, titanium, and debris from low alloy steel. The solids contain low concentrations of plutonium and strontium. These isotopes are associated with the titanium that came from the monosodium titanate (MST) added in the Actinide Removal Process (ARP) most likely as leached Ti from the MST that precipitated subsequently in MCU. An attempt was also made to obtain samples from the contents of Wash Contactor SEP-702. However, sampling provide ineffective.

  16. November 12, 2012: "Titan" named world's most powerful supercomputer |

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

    Department of Energy 2, 2012: "Titan" named world's most powerful supercomputer November 12, 2012: "Titan" named world's most powerful supercomputer November 12, 2012: "Titan" named world's most powerful supercomputer Secretary Chu announces that Titan, a new supercomputer located at DOE's Oak Ridge National Laboratory, has been named the world's most powerful according to the TOP500 list of the world's fastest supercomputers. Ten times more powerful than its

  17. DWPF FLOWSHEET STUDIES WITH SIMULANT TO DETERMINE THE IMPACT OF NEXT GENERATION SOLVENT ON THE CPC PROCESS AND GLASS FORMULATION

    SciTech Connect (OSTI)

    Newell, J.; Peeler, D.; Edwards, T.; Hay, M.; Stone, M.

    2011-06-29

    As a part of the Actinide Removal Process (ARP)/Modular Caustic Side Solvent Extraction Unit (MCU) Life Extension Project, a next generation solvent (NGS), a new strip acid, and modified monosodium titanate (mMST) will be deployed. The NGS is comprised of four components: 0.050 M MaxCalix (extractant), 0.50 M Cs-7SB (modifier), 0.003 M guanidine-LIX-79, with the balance ({approx}74 wt%) being Isopar{reg_sign} L. The strip acid will be changed from dilute nitric acid to dilute boric acid (0.01 M). Because of these changes, experimental testing with the next generation solvent and mMST was required to determine the impact of these changes in 512-S and Defense Waste Processing Facility (DWPF) operations, as well as Chemical Process Cell (CPC), glass formulation activities, and melter operations. Because of these changes, experimental testing with the next generation solvent and mMST is required to determine the impact of these changes. A Technical Task Request (TTR) was issued to support the assessments of the impact of the next generation solvent and mMST on the downstream DWPF flowsheet unit. The TTR identified five tasks to be investigated: (1) CPC Flowsheet Demonstration for NGS; (2) Solvent Stability for DWPF CPC Conditions; (3) Glass Formulation Studies; (4) Boron Volatility and Melt Rate; and (5) CPC Flowsheet Demonstration for mMST.

  18. ATOMIC CARBON IN THE UPPER ATMOSPHERE OF TITAN

    SciTech Connect (OSTI)

    Zhang, X.; Yung, Y. L.; Ajello, J. M.

    2010-01-01

    The atomic carbon emission C I line feature at 1657 A ({sup 3} P {sup 0} {sub J}-{sup 3} P{sub J} ) in the upper atmosphere of Titan is first identified from the airglow spectra obtained by the Cassini Ultra-violet Imaging Spectrograph. A one-dimensional photochemical model of Titan is used to study the photochemistry of atomic carbon on Titan. Reaction between CH and atomic hydrogen is the major source of atomic carbon, and reactions with hydrocarbons (C{sub 2}H{sub 2} and C{sub 2}H{sub 4}) are the most important loss processes. Resonance scattering of sunlight by atomic carbon is the dominant emission mechanism. The emission intensity calculations based on model results show good agreement with the observations.

  19. Anomalous ion heating and superthermal electrons in the MST reversed-field pinch

    SciTech Connect (OSTI)

    Hokin, S.; Almagri, A.; Assadi, S.; Cekic, M.; Chapman, B.; Chartas, G.; Crocker, N.; Cudzinovic, M.; Den Hartog, D.J.; Dexter, R.; Fiksel, G.; Fonck, R.; Henry, J.; Holly, D.; Prager, S.; Rempel, T.; Sarff, J.; Scime, E.; Shen, W.; Sprott, C.; Stoneking, M.; Watts, C.

    1992-09-01

    Anomalous ion heating and superthermal electron populations have been studied in the MST reversed-field pinch. The ion heating is much stronger than that given by classical electron-ion friction, and is particularly strong during dynamo bursts. The heating displays a marked density dependence: in a 350-kA discharge with a maximum {bar n} = 0.9 {times} 10{sup 13} cm{sup {minus} 3}, T{sub i} rises sharply as {bar n} drops below 0.4 {times} 10{sub 13} cm{sup {minus}3} late in the discharge. Superthermal electrons are produced in the core, with temperatures of T{sub eh}, = 350--700 eV while the bulk core temperature is T{sub e}o = 130--230 eV. The fraction of superthermal electrons decreases with increasing density, from 40% at {bar n} = 0.5 {times} 10{sup 13} cm{sup {minus}3} to 8% at {bar n} = 1.9 {times} 10{sup 13} cm{sup {minus}3} at I = 350 kA. However, data with similar plasma parameters but higher oxygen impurity content had a lower T{sub eh} and higher hot fraction. The edge superthermal electron distribution is well fit by a drifted bi-Maxwellian distribution with T{sub {parallel}} {approximately} T{sub e0} and relative drift speed v{sub d}/v{sub th} = 0.4. With the assumption that the parallel heat flux measured with a pyroelectric probe is carried by superthermal electrons, the measured electron current is consistent with T{sub {perpendicular}} {approximately} T{sub ea} {approximately} T{sub e0}/3 and accounts for over half of the total edge parallel current measured with magnetic probes.

  20. Methods for producing monodispersed particles of barium titanate

    DOE Patents [OSTI]

    Hu, Zhong-Cheng

    2001-01-01

    The present invention is a low-temperature controlled method for producing high-quality, ultrafine monodispersed nanocrystalline microsphere powders of barium titanate and other pure or composite oxide materials having particles ranging from nanosized to micronsized particles. The method of the subject invention comprises a two-stage process. The first stage produces high quality monodispersed hydrous titania microsphere particles prepared by homogeneous precipitation via dielectric tuning in alcohol-water mixed solutions of inorganic salts. Titanium tetrachloride is used as an inorganic salt precursor material. The second stage converts the pure hydrous titania microsphere particles into crystalline barium titanate microsphere powders via low-temperature, hydrothermal reactions.

  1. Northern Virginia Technology Council Titans' Breakfast | Department of

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

    Energy Northern Virginia Technology Council Titans' Breakfast Northern Virginia Technology Council Titans' Breakfast September 25, 2008 - 3:43pm Addthis Remarks as Prepared for Secretary Bodman Thank you, Gary. It is good to be here with all of you this morning to talk about America's energy future. You certainly don't need reminding that our world is confronting a rapidly growing demand for energy, rising prices, and an urgent need to produce and use energy more cleanly and efficiently in

  2. Reducing and measuring fluctuations in the MST RFP: Enhancement of energy confinement and measurement of the MHD dynamo

    SciTech Connect (OSTI)

    Den Hartog, D.J.; Almagri, A.F.; Cekic, M.

    1996-09-01

    A three- to five-fold enhancement of the energy confinement time in a reversed-field pinch (RFP) has been achieved in the Madison Symmetric Torus (MST) by reducing the amplitude of tearing mode fluctuations responsible for anomalous transport in the core of the RFP. By applying a transient poloidal inductive electric field to flatten the current density profile, the fluctuation amplitude {tilde b}/B decreases from 1.5% to 0.8%, the electron temperature T{sub e0} increases from 250 eV to 370 eV, the ohmic input power decreases from 4.5 MW to approximately 1.5 MW, the poloidal beta {beta}{sub 0} increases from 6% to 9%, and the energy confinement time {tau}{sub E} increases from 1 ms to {approximately}5 ms in I{sub {phi}} = 340 kA plasmas with density {tilde n} = 1 {times} 10{sup 19} m{sup -3}. Current profile control methods are being developed for the RFP in a program to eliminate transport associated with these current-gradient-driven fluctuations. In addition to controlling the amplitude of the tearing modes, we are vigorously pursuing an understanding of the physics of these fluctuations. In particular, plasma flow, both equilibrium and fluctuating, plays a critical role in a diversity of physical phenomena in MST. The key results: 1) Edge probe measurements show that the MHD dynamo is active in low collisionality plasmas, while at high collisionality a new mechanism, the `electron diamagnetic dynamo,` is observed. 2) Core spectroscopic measurements show that the toroidal velocity fluctuations of the plasma are coherent with the large-scale magnetic tearing modes; the scalar product of these two fluctuating quantities is similar to that expected for the MHD dynamo electromotive force. 3) Toroidal plasma flow in MST exhibits large radial shear and can be actively controlled, including unlocking locked discharges, by modifying E{sub r} with a robust biased probe. 24 refs.

  3. Identification and mitigation of stray laser light in the Thomson scattering system on the Madison Symmetric Torus (MST)

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

    and mitigation of stray laser light in the Thomson scattering system on the Madison Symmetric Torus (MST) C. M. Jacobson, M. T. Borchardt, D. J. Den Hartog, A. F. Falkowski, L. A. Morton, and M. A. Thomas Citation: Review of Scientific Instruments 87, 11E511 (2016); doi: 10.1063/1.4960063 View online: http://dx.doi.org/10.1063/1.4960063 View Table of Contents: http://scitation.aip.org/content/aip/journal/rsi/87/11?ver=pdfcov Published by the AIP Publishing Articles you may be interested in A

  4. LARGE ABUNDANCES OF POLYCYCLIC AROMATIC HYDROCARBONS IN TITAN'S UPPER ATMOSPHERE

    SciTech Connect (OSTI)

    Lopez-Puertas, M.; Funke, B.; Garcia-Comas, M.; Dinelli, B. M.; Adriani, A.; D'Aversa, E.; Moriconi, M. L.; Boersma, C.; Allamandola, L. J.

    2013-06-20

    In this paper, we analyze the strong unidentified emission near 3.28 {mu}m in Titan's upper daytime atmosphere recently discovered by Dinelli et al. We have studied it by using the NASA Ames PAH IR Spectroscopic Database. The polycyclic aromatic hydrocarbons (PAHs), after absorbing UV solar radiation, are able to emit strongly near 3.3 {mu}m. By using current models for the redistribution of the absorbed UV energy, we have explained the observed spectral feature and have derived the vertical distribution of PAH abundances in Titan's upper atmosphere. PAHs have been found to be present in large concentrations, about (2-3) Multiplication-Sign 10{sup 4} particles cm{sup -3}. The identified PAHs have 9-96 carbons, with a concentration-weighted average of 34 carbons. The mean mass is {approx}430 u; the mean area is about 0.53 nm{sup 2}; they are formed by 10-11 rings on average, and about one-third of them contain nitrogen atoms. Recently, benzene together with light aromatic species as well as small concentrations of heavy positive and negative ions have been detected in Titan's upper atmosphere. We suggest that the large concentrations of PAHs found here are the neutral counterpart of those positive and negative ions, which hence supports the theory that the origin of Titan main haze layer is located in the upper atmosphere.

  5. Attrition resistant, zinc titanate-containing, reduced sulfur sorbents

    DOE Patents [OSTI]

    Vierheilig, Albert A.; Gupta, Raghubir P.; Turk, Brian S.

    2004-11-02

    The disclosure is directed to sorbent compositions for removing reduced sulfur species (e.g., H.sub.2 S, COS and CS.sub.2) a feed stream. The sorbent is formed from a multi-phase composition including a zinc titanate phase and a zinc oxide-aluminate phase. The sorbent composition is substantially free of unreacted alumina.

  6. Safety evaluation of RTG launches aboard Titan IV launch vehicles

    SciTech Connect (OSTI)

    Rosko, Robert J.; Loughin, Stephen

    1997-01-10

    The analytical tool used to evaluate accidents aboard a Titan IV launch vehicle involving a Radioisotope Thermoelectric Generator (RTG) is discussed. The Launch Accident Scenario Evaluation Program-Titan IV version (LASEP-T) uses a Monte Carlo approach to determine the response of an RTG to various threatening environments. The threatening environments arise from a complex interplay of probabilistic and deterministic processes, and are therefore parameterized by a set of random variables with probability distributions. The assessment of the RTG response to a given environment is based on both empirical data and theoretical modeling. Imbedding detailed, complex response models into the LASEP-T calculation was not practical. Simpler response models have been constructed to capture both the inherent variability due to the phenomenology of the accident scenario along with the uncertainty of predicting response behavior. The treatment of variability and uncertainty as it pertains to the launch accident evaluation of RTG response will be discussed.

  7. Method for removing metal ions from solution with titanate sorbents

    SciTech Connect (OSTI)

    Lundquist, S.H.; White, L.R.

    1999-11-23

    A method for removing metal ions from solution comprises the steps of providing titanate particles by spray-drying a solution or slurry comprising sorbent titanates having a particle size up to 20 micrometers, optionally in the presence of polymer free of cellulose functionality as binder. The sorbent is active towards heavy metals from Periodic Table (CAS version) Groups IA, IIA, IB, IIB, IIIB, and VIII, to provide monodisperse, substantially spherical particles in a yield of at least 70% of theoretical yield which have a particle size distribution in the range of 1 to 500 micrometers. The particles can be used free flowing in columns or beds, or entrapped in a nonwoven, fibrous web or matrix or a cast porous membrane, to selectively remove metal ions from aqueous or organic liquid.

  8. Method for removing metal ions from solution with titanate sorbents

    DOE Patents [OSTI]

    Lundquist, Susan H.; White, Lloyd R.

    1999-01-01

    A method for removing metal ions from solution comprises the steps of providing titanate particles by spray-drying a solution or slurry comprising sorbent titanates having a particle size up to 20 micrometers, optionally in the presence of polymer free of cellulose functionality as binder, said sorbent being active towards heavy metals from Periodic Table (CAS version) Groups IA, IIA, IB, IIB, IIIB, and VIII, to provide monodisperse, substantially spherical particles in a yield of at least 70 percent of theoretical yield and having a particle size distribution in the range of 1 to 500 micrometers. The particles can be used free flowing in columns or beds, or entrapped in a nonwoven, fibrous web or matrix or a cast porous membrane, to selectively remove metal ions from aqueous or organic liquid.

  9. P-type conductivity in annealed strontium titanate

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

    Poole, Violet M.; Corolewski, Caleb D.; McCluskey, Matthew D.

    2015-12-17

    In this study, Hall-effect measurements indicate p-type conductivity in bulk, single-crystal strontium titanate (SrTiO3, or STO) samples that were annealed at 1200°C. Room temperature mobilities above 100 cm2/Vs were measured, an order of magnitude higher than those for electrons (5-10 cm2/Vs). Average hole densities were in the 109-1010 cm-3 range, consistent with a deep acceptor.

  10. CASSINI VIMS OBSERVATIONS SHOW ETHANE IS PRESENT IN TITAN'S RAINFALL

    SciTech Connect (OSTI)

    Dalba, Paul A.; Buratti, Bonnie J.; Baines, Kevin H.; Sotin, Christophe; Lawrence, Kenneth J.; Brown, Robert H.; Barnes, Jason W.; Clark, Roger N.; Nicholson, Philip D.

    2012-12-20

    Observations obtained over two years by the Cassini Imaging Science Subsystem suggest that rain showers fall on the surface. Using measurements obtained by the Visual Infrared Mapping Spectrometer, we identify the main component of the rain to be ethane, with methane as an additional component. We observe five or six probable rainfall events, at least one of which follows a brief equatorial cloud appearance, suggesting that frequent rainstorms occur on Titan. The rainfall evaporates, sublimates, or infiltrates on timescales of months, and in some cases it is associated with fluvial features but not with their creation or alteration. Thus, Titan exhibits frequent 'gentle rainfall' instead of, or in addition to, more catastrophic events that cut rivers and lay down large fluvial deposits. Freezing rain may also be present, and the standing liquid may exist as puddles interspersed with patches of frost. The extensive dune deposits found in the equatorial regions of Titan imply multi-season arid conditions there, which are consistent with small, but possibly frequent, amounts of rain, in analogy to terrestrial deserts.

  11. Midterm Summary of Japan-US Fusion Cooperation Program TITAN

    SciTech Connect (OSTI)

    Muroga, Takeo; Sze, Dai-Kai; Sokolov, Mikhail; Katoh, Yutai; Stoller, Roger E

    2011-01-01

    Japan-US cooperation program TITAN (Tritium, Irradiation and Thermofluid for America and Nippon) started in April 2007 as 6-year project. This is the summary report at the midterm of the project. Historical overview of the Japan-US cooperation programs and direction of the TITAN project in its second half are presented in addition to the technical highlights. Blankets are component systems whose principal functions are extraction of heat and tritium. Thus it is crucial to clarify the potentiality for controlling heat and tritium flow throughout the first wall, blanket and out-of-vessel recovery systems. The TITAN project continues the JUPITER-II activity but extends its scope including the first wall and the recovery systems with the title of 'Tritium and thermofluid control for magnetic and inertial confinement systems'. The objective of the program is to clarify the mechanisms of tritium and heat transfer throughout the first-wall, the blanket and the heat/tritium recovery systems under specific conditions to fusion such as irradiation, high heat flux, circulation and high magnetic fields. Based on integrated models, the breeding, transfer, inventory of tritium and heat extraction properties will be evaluated for some representative liquid breeder blankets and the necessary database will be obtained for focused research in the future.

  12. ISOTOPIC RATIOS IN TITAN's METHANE: MEASUREMENTS AND MODELING

    SciTech Connect (OSTI)

    Nixon, C. A.; Achterberg, R. K.; Temelso, B.; Vinatier, S.; Bezard, B.; Coustenis, A.; Teanby, N. A.; Mandt, K. E.; Sherrill, C. D.; Irwin, P. G. J.; Jennings, D. E.; Romani, P. N.; Flasar, F. M.

    2012-04-20

    The existence of methane in Titan's atmosphere ({approx}6% level at the surface) presents a unique enigma, as photochemical models predict that the current inventory will be entirely depleted by photochemistry in a timescale of {approx}20 Myr. In this paper, we examine the clues available from isotopic ratios ({sup 12}C/{sup 13}C and D/H) in Titan's methane as to the past atmosphere history of this species. We first analyze recent infrared spectra of CH{sub 4} collected by the Cassini Composite Infrared Spectrometer, measuring simultaneously for the first time the abundances of all three detected minor isotopologues: {sup 13}CH{sub 4}, {sup 12}CH{sub 3}D, and {sup 13}CH{sub 3}D. From these we compute estimates of {sup 12}C/{sup 13}C = 86.5 {+-} 8.2 and D/H = (1.59 {+-} 0.33) Multiplication-Sign 10{sup -4}, in agreement with recent results from the Huygens GCMS and Cassini INMS instruments. We also use the transition state theory to estimate the fractionation that occurs in carbon and hydrogen during a critical reaction that plays a key role in the chemical depletion of Titan's methane: CH{sub 4} + C{sub 2}H {yields} CH{sub 3} + C{sub 2}H{sub 2}. Using these new measurements and predictions we proceed to model the time evolution of {sup 12}C/{sup 13}C and D/H in Titan's methane under several prototypical replenishment scenarios. In our Model 1 (no resupply of CH{sub 4}), we find that the present-day {sup 12}C/{sup 13}C implies that the CH{sub 4} entered the atmosphere 60-1600 Myr ago if methane is depleted by chemistry and photolysis alone, but much more recently-most likely less than 10 Myr ago-if hydrodynamic escape is also occurring. On the other hand, if methane has been continuously supplied at the replenishment rate then the isotopic ratios provide no constraints, and likewise for the case where atmospheric methane is increasing. We conclude by discussing how these findings may be combined with other evidence to constrain the overall history of the atmospheric

  13. Enhanced flexoelectricity through residual ferroelectricity in barium strontium titanate

    SciTech Connect (OSTI)

    Garten, Lauren M. Trolier-McKinstry, Susan

    2015-03-07

    Residual ferroelectricity is observed in barium strontium titanate ceramics over 30 °C above the global phase transition temperature, in the same temperature range in which anomalously large flexoelectric coefficients are reported. The application of a strain gradient leads to strain gradient-induced poling or flexoelectric poling. This was observed by the development of a remanent polarization in flexoelectric measurements, an induced d{sub 33} piezoelectric response even after the strain gradient was removed, and the production of an internal bias of 9 kV m{sup −1}. It is concluded that residual ferroelectric response considerably enhances the observed flexoelectric response.

  14. Strain engineered barium strontium titanate for tunable thin film resonators

    SciTech Connect (OSTI)

    Khassaf, H.; Khakpash, N.; Sun, F.; Sbrockey, N. M.; Tompa, G. S.; Kalkur, T. S.; Alpay, S. P.

    2014-05-19

    Piezoelectric properties of epitaxial (001) barium strontium titanate (BST) films are computed as functions of composition, misfit strain, and temperature using a non-linear thermodynamic model. Results show that through adjusting in-plane strains, a highly adaptive rhombohedral ferroelectric phase can be stabilized at room temperature with outstanding piezoelectric response exceeding those of lead based piezoceramics. Furthermore, by adjusting the composition and the in-plane misfit, an electrically tunable piezoelectric response can be obtained in the paraelectric state. These findings indicate that strain engineered BST films can be utilized in the development of electrically tunable and switchable surface and bulk acoustic wave resonators.

  15. Dielectric behavior of barium modified strontium bismuth titanate ceramic

    SciTech Connect (OSTI)

    Nayak, P.; Badapanda, T.; Anwar, S.; Panigrahi, S.

    2014-04-24

    Barium Modified Strontium Bismuth Titanate(SBT) ceramic with general formula Sr1?xBaxBi4Ti4O15 is prepared by solid state reaction route. The structural analysis of the ceramics was done by X-ray diffraction technique. The X-ray patterns show that all the compositions are of single phase with orthorhombic structure. The temperature dependent dielectric behavior shows that the transition temperature decreases with Ba content but the maximum dielectric constant increases. The decreases of the transition with increase in Ba{sup 2+} ion, may be due to the decrease of orthorhombicity by the incorporation of Ba{sup 2+} ion in SBT lattice.

  16. P-type conductivity in annealed strontium titanate

    SciTech Connect (OSTI)

    Poole, Violet M.; Corolewski, Caleb D.; McCluskey, Matthew D.

    2015-12-17

    In this study, Hall-effect measurements indicate p-type conductivity in bulk, single-crystal strontium titanate (SrTiO3, or STO) samples that were annealed at 1200°C. Room temperature mobilities above 100 cm2/Vs were measured, an order of magnitude higher than those for electrons (5-10 cm2/Vs). Average hole densities were in the 109-1010 cm-3 range, consistent with a deep acceptor.

  17. P-type conductivity in annealed strontium titanate

    SciTech Connect (OSTI)

    Poole, Violet M.; Corolewski, Caleb D.; McCluskey, Matthew D.

    2015-12-15

    Hall-effect measurements indicate p-type conductivity in bulk, single-crystal strontium titanate (SrTiO{sub 3}, or STO) samples that were annealed at 1200°C. Room-temperature mobilities above 100 cm{sup 2}/V s were measured, an order of magnitude higher than those for electrons (5-10 cm{sup 2}/V s). Average hole densities were in the 10{sup 9}-10{sup 10} cm{sup −3} range, consistent with a deep acceptor.

  18. Safety evaluation of RTG launches aboard Titan IV launch vehicles

    SciTech Connect (OSTI)

    Rosko, R.J.; Loughin, S.

    1997-01-01

    The analytical tool used to evaluate accidents aboard a Titan IV launch vehicle involving a Radioisotope Thermoelectric Generator (RTG) is discussed. The Launch Accident Scenario Evaluation Program-Titan IV version (LASEP-T) uses a Monte Carlo approach to determine the response of an RTG to various threatening environments. The threatening environments arise from a complex interplay of probabilistic and deterministic processes, and are therefore parameterized by a set of random variables with probability distributions. The assessment of the RTG response to a given environment is based on both empirical data and theoretical modeling. Imbedding detailed, complex response models into the LASEP-T calculation was not practical. Simpler response models have been constructed to capture both the inherent variability due to the phenomenology of the accident scenario along with the uncertainty of predicting response behavior. The treatment of variability and uncertainty as it pertains to the launch accident evaluation of RTG response will be discussed. {copyright} {ital 1997 American Institute of Physics.}

  19. AN ESTIMATE OF THE CHEMICAL COMPOSITION OF TITAN's LAKES

    SciTech Connect (OSTI)

    Cordier, Daniel; Mousis, Olivier; Lunine, Jonathan I.; Lavvas, Panayotis; Vuitton, Veronique

    2009-12-20

    Hundreds of radar-dark patches interpreted as lakes have been discovered in the north and south polar regions of Titan. We have estimated the composition of these lakes by using the direct abundance measurements from the Gas Chromatograph Mass Spectrometer aboard the Huygens probe and recent photochemical models based on the vertical temperature profile derived by the Huygens Atmospheric Structure Instrument. Thermodynamic equilibrium is assumed between the atmosphere and the lakes, which are also considered nonideal solutions. We find that the main constituents of the lakes are ethane (C{sub 2}H{sub 6}) (approx76%-79%), propane (C{sub 3}H{sub 8}) (approx7%-8%), methane (CH{sub 4}) (approx5%-10%), hydrogen cyanide (HCN) (approx2%-3%), butene (C{sub 4}H{sub 8}) (approx1%), butane (C{sub 4}H{sub 10}) (approx1%), and acetylene (C{sub 2}H{sub 2}) (approx1%). The calculated composition of lakes is then substantially different from what has been expected from models elaborated prior to the exploration of Titan by the Cassini-Huygens spacecraft.

  20. Spray drying of metal alkoxide sol for strontium titanate ceramics

    SciTech Connect (OSTI)

    Varma, H.K.; Pillai, P.K.; Mani, T.V.; Warrier, K.G.K.; Damodaran, A.D.

    1994-01-01

    Conditions for obtaining a stable sol in an isopropyl alcohol-water medium containing titanium isopropoxide and strontium nitrate, and acetic acid as a modifier, have been described. Spray drying of the sol results in submicrometer spherical agglomerates which on further thermal decomposition yield submicrometer particles of strontium titanate at temperatures as low as 500 C. The thermal decomposition characteristics of the spray-dried precursor and the development of strontium titanate phase have been discussed. Calcined precursor powder possesses a specific surface area of 12 m{sup 2}/g, a compaction density of 57%, and a sintered density of > 98%. The optimum sintering temperature of such a powder was 1450 C, which resulted in a sintered grain size around 1.5 {mu}m. Further, such a sintered sample had a dielectric constant of 260 and a loss factor of 0.008 at 1 kHz. This method appears to be very convenient with respect to handling of stable sols and thus avoids the usual difficulties regarding extended gelation as well as inhomogeneous precipitation.

  1. Untangling the Chemical Evolution of Titan's Atmosphere and Surface -- From Homogeneous to Heterogeneous Chemistry

    SciTech Connect (OSTI)

    Kaiser, Ralf I.; Maksyutenko, Pavlo; Ennis, Courtney; Zhang, Fangtong; Gu, Xibin; Krishtal, Sergey P.; Mebel, Alexander M.; Kostko, Oleg; Ahmed, Musahid

    2010-03-16

    The arrival of the Cassini-Huygens probe at Saturn's moon Titan - the only Solar System body besides Earth and Venus with a solid surface and a thick atmosphere with a pressure of 1.4 atm at surface level - in 2004 opened up a new chapter in the history of Solar System exploration. The mission revealed Titan as a world with striking Earth-like landscapes involving hydrocarbon lakes and seas as well as sand dunes and lava-like features interspersed with craters and icy mountains of hitherto unknown chemical composition. The discovery of a dynamic atmosphere and active weather system illustrates further the similarities between Titan and Earth. The aerosol-based haze layers, which give Titan its orange-brownish color, are not only Titan's most prominent optically visible features, but also play a crucial role in determining Titan's thermal structure and chemistry. These smog-like haze layers are thought to be very similar to those that were present in Earth's atmosphere before life developed more than 3.8 billion years ago, absorbing the destructive ultraviolet radiation from the Sun, thus acting as 'prebiotic ozone' to preserve astrobiologically important molecules on Titan. Compared to Earth, Titan's low surface temperature of 94 K and the absence of liquid water preclude the evolution of biological chemistry as we know it. Exactly because of these low temperatures, Titan provides us with a unique prebiotic 'atmospheric laboratory' yielding vital clues - at the frozen stage - on the likely chemical composition of the atmosphere of the primitive Earth. However, the underlying chemical processes, which initiate the haze formation from simple molecules, have been not understood well to date.

  2. TESTING OF A FULL-SCALE ROTARY MICROFILTER FOR THE ENHANCED PROCESS FOR RADIONUCLIDES REMOVAL

    SciTech Connect (OSTI)

    Herman, D; David Stefanko, D; Michael Poirier, M; Samuel Fink, S

    2009-01-01

    Savannah River National Laboratory (SRNL) researchers are investigating and developing a rotary microfilter for solid-liquid separation applications in the Department of Energy (DOE) complex. One application involves use in the Enhanced Processes for Radionuclide Removal (EPRR) at the Savannah River Site (SRS). To assess this application, the authors performed rotary filter testing with a full-scale, 25-disk unit manufactured by SpinTek Filtration with 0.5 micron filter media manufactured by Pall Corporation. The filter includes proprietary enhancements by SRNL. The most recent enhancement is replacement of the filter's main shaft seal with a John Crane Type 28LD gas-cooled seal. The feed material was SRS Tank 8F simulated sludge blended with monosodium titanate (MST). Testing examined total insoluble solids concentrations of 0.06 wt % (126 hours of testing) and 5 wt % (82 hours of testing). The following are conclusions from this testing.

  3. Nonlinear transport in ionic liquid gated strontium titanate nanowires

    SciTech Connect (OSTI)

    Bretz-Sullivan, Terence M.; Goldman, A. M.

    2015-09-14

    Measurements of the current-voltage (I–V) characteristics of ionic liquid gated nanometer scale channels of strontium titanate have been carried out. At low gate voltages, the I–V characteristics exhibit a large voltage threshold for conduction and a nonlinear power law behavior at all temperatures measured. The source-drain current of these nanowires scales as a power law of the difference between the source-drain voltage and the threshold voltage. The scaling behavior of the I–V characteristic is reminiscent of collective electronic transport through an array of quantum dots. At large gate voltages, the narrow channel acts as a quasi-1D wire whose conductance follows Landauer's formula for multichannel transport.

  4. Production of Synroc ceramics from titanate gel microspheres

    SciTech Connect (OSTI)

    Sizgek, E.; Bartlett, J.R.; Woolfrey, J.L.; Vance, E.R.

    1994-12-31

    Synroc is a multi-component titanate ceramic, designed to immobilise High Level Waste (HLW) from nuclear fuel reprocessing plants. Synroc precursor powders have been previously produced by various methods, such as oxide and alkoxide-hydrolysis routes. However, various technological aspects of HLW processing make the use of free-flowing, dust-free, highly sinterable precursor powders desirable. Such powders have been produced by spray-drying colloidal precursors, yielding microspherical particles with controlled porosity. These particles were readily impregnated with 20 wt% simulated high-level nuclear waste solutions, calcined at 1023 K and subsequently hot-pressed to produce dense Synroc monoliths. This paper discusses the preparation and fabrication of Synroc monoliths from the microspheres and their physical properties. The resulting microstructures and leaching characteristics of the Synroc monoliths are also presented.

  5. OSTIblog Articles in the Titan Topic | OSTI, US Dept of Energy Office of

    Office of Scientific and Technical Information (OSTI)

    Scientific and Technical Information Titan Topic A banner year expected for high-performance computing by Kathy Chambers 05 Feb, 2014 in Science Communications 14246 Titan2.jpg A banner year expected for high-performance computing Read more about 14246 Just seven miles south of our OSTI facility in Oak Ridge, Tennessee is a national treasure - the Oak Ridge National Laboratory (ORNL). ORNL is DOE's largest multi-program laboratory where remarkable scientific expertise and world-class

  6. Fabrication and characterization of cerium-doped barium titanate inverse opal by sol-gel method

    SciTech Connect (OSTI)

    Jin Yi; Zhu Yihua Yang Xiaoling; Li Chunzhong; Zhou Jinghong

    2007-01-15

    Cerium-doped barium titanate inverted opal was synthesized from barium acetate contained cerous acetate and tetrabutyl titanate in the interstitial spaces of a polystyrene (PS) opal. This procedure involves infiltration of precursors into the interstices of the PS opal template followed by hydrolytic polycondensation of the precursors to amorphous barium titanate and removal of the PS opal by calcination. The morphologies of opal and inverse opal were characterized by scanning electron microscope (SEM). The pores were characterized by mercury intrusion porosimetry (MIP). X-ray photoelectron spectroscopy (XPS) investigation showed the doping structure of cerium, barium and titanium. And powder X-ray diffraction allows one to observe the influence of doping degree on the grain size. The lattice parameters, crystal size and lattice strain were calculated by the Rietveld refinement method. The synthesis of cerium-doped barium titanate inverted opals provides an opportunity to electrically and optically engineer the photonic band structure and the possibility of developing tunable three-dimensional photonic crystal devices. - Graphical abstract: Cerium-doped barium titanate inverted opal was synthesized from barium acetate acid contained cerous acetate and tetrabutyl titanate in the interstitial spaces of a PS opal, which involves infiltration of precursors into the interstices of the PS opal template and removal of the PS opal by calcination.

  7. Formation of titanate nanostructures under different NaOH concentration and their application in wastewater treatment

    SciTech Connect (OSTI)

    Huang Jiquan; Cao Yongge; Deng Zhonghua; Tong Hao

    2011-03-15

    The effects of the concentration of NaOH on the formation and transformation of various titanate nanostructures were studied. With increasing NaOH concentration, three different formation mechanisms were proposed. Nanotubes can only be obtained under moderate NaOH conditions, and should transform into nanowires with prolonged hydrothermal treatment, and their formation rate is accelerated by increasing NaOH concentration. Low concentration of NaOH results in the direct formation of nanowires, while extra high concentration of NaOH leads to the formation of amorphous nanoparticles. Adsorption and photocatalysis studies show that titanate nanowires and nanotubes might be potential adsorbents for the removal of both heavy metal ions and dyes and photocatalysts for the removal of dyes from wastewater. -- Graphical abstract: The morphologies of the titanates depend deeply on the concentration of NaOH. With increasing NaOH concentration, three different formation mechanisms were proposed. The application of these titanate nanostructures in the wastewater treatment was studied. Display Omitted Research highlights: {yields} Effect of NaOH concentration on the structures of various titanates was reported. {yields} Three different formation mechanisms were presented with increasing NaOH concentration. {yields} Various titanates were used as adsorbents/photocatalysts in wastewater treatment.

  8. PROCESSING ALTERNATIVES FOR DESTRUCTION OF TETRAPHENYLBORATE

    SciTech Connect (OSTI)

    Lambert, D; Thomas Peters, T; Samuel Fink, S

    2007-02-27

    Two processes were chosen in the 1980's at the Savannah River Site (SRS) to decontaminate the soluble High Level Waste (HLW). The In Tank Precipitation (ITP) process (1,2) was developed at SRS for the removal of radioactive cesium and actinides from the soluble HLW. Sodium tetraphenylborate was added to the waste to precipitate cesium and monosodium titanate (MST) was added to adsorb actinides, primarily uranium and plutonium. Two products of this process were a low activity waste stream and a concentrated organic stream containing cesium tetraphenylborate and actinides adsorbed on monosodium titanate (MST). A copper catalyzed acid hydrolysis process was built to process (3, 4) the Tank 48H cesium tetraphenylborate waste in the SRS's Defense Waste Processing Facility (DWPF). Operation of the DWPF would have resulted in the production of benzene for incineration in SRS's Consolidated Incineration Facility. This process was abandoned together with the ITP process in 1998 due to high benzene in ITP caused by decomposition of excess sodium tetraphenylborate. Processing in ITP resulted in the production of approximately 1.0 million liters of HLW. SRS has chosen a solvent extraction process combined with adsorption of the actinides to decontaminate the soluble HLW stream (5). However, the waste in Tank 48H is incompatible with existing waste processing facilities. As a result, a processing facility is needed to disposition the HLW in Tank 48H. This paper will describe the process for searching for processing options by SRS task teams for the disposition of the waste in Tank 48H. In addition, attempts to develop a caustic hydrolysis process for in tank destruction of tetraphenylborate will be presented. Lastly, the development of both a caustic and acidic copper catalyzed peroxide oxidation process will be discussed.

  9. RESULTS OF ROUTINE STRIP EFFLUENT HOLD TANK AND DECONTAMINATED SALT SOLUTION HOLD TANK SAMPLES FROM MODULAR CAUSTIC-SIDE SOLVENT EXTRACTION UNIT DURING MACROBATCH 3 OPERATIONS

    SciTech Connect (OSTI)

    Peters, T.; Fink, S.

    2011-06-10

    Strip Effluent Hold Tank (SEHT) and Decontaminated Salt Solution Hold Tank (DSSHT) samples from several of the 'microbatches' of Integrated Salt Disposition Project (ISDP) Salt Batch ('Macrobatch') 3 have been analyzed for {sup 238}Pu, {sup 90}Sr, {sup 137}Cs, and by Inductively Coupled Plasma Emission Spectroscopy (ICPES). The results indicate good decontamination performance within process design expectations. While the data set is sparse, the results of this set and the previous set of results for Macrobatch 3 samples indicate consistent operations. However, the Decontamination Factors for plutonium and strontium removal have declined in Macrobatch 3, compared to Macrobatch 2. This may be due to the differences in the Pu concentration or the bulk chemical concentrations in the feed material. SRNL is considering the possible reasons for this decline. The DSSHT samples show continued presence of titanium, likely from leaching of the monosodium titanate in ARP. During operation of the ISDP, quantities of salt waste are processed through the Actinide Removal Process (ARP) and MCU in batches of {approx}3800 gallons. Monosodium titanate (MST) is used in ARP to adsorb actinides and strontium from the salt waste and the waste slurry is then filtered prior to sending the clarified salt solution to MCU. The MCU uses solvent extraction technology to extract cesium from salt waste and concentrate cesium in an acidic aqueous stream (Strip Effluent - SE), leaving a decontaminated caustic salt aqueous stream (Decontaminated Salt Solution - DSS). Sampling occurs in the Decontaminated Salt Solution Hold Tank (DSSHT) and Strip Effluent Hold Tank (SEHT) in the MCU process. The MCU sample plan requires that batches be sampled and analyzed for plutonium and strontium content by Savannah River National Lab (SRNL) to determine MST effectiveness. The cesium measurement is used to monitor cesium removal effectiveness and the inductively coupled plasma emission spectroscopy (ICPES) is

  10. Hexagonal phase transformation in the engineered scavenger compound lithium titanate

    SciTech Connect (OSTI)

    Collins, W.K.; Riley, W.D.; Jong, B.W.

    1993-01-01

    Engineered scavenger compounds (ESC's) developed by the US Bureau of Mines are a novel class of compounds that selectively can recover a desired element from a solid or molten alloy. Lithium titanate (Li[sub 2]Ti[sub 3]O[sub 7] or Li[sub 2]O [center dot] 3TiO[sub 2]) is used as an ESC to recover lithium (Li) from aluminum-lithium (Al-Li) alloys. X-ray diffraction measurements have shown that Li[sub 2]Ti[sub 3]O[sub 7] undergoes a phase change during scavenging from an orthorhombic structure to a hexagonal structure. This change is due to the incorporation of lithium in the matrix of the material and the effect of temperature. Although both phases are metastable, the hexagonal phase that forms during the scavenging of lithium from Al-Li alloys appears to be the more stable phase. Recovering lithium from the ESC by electrodeposition does not cause the structure to revert to the orthorhombic phase. The orthorhombic and the hexagonal structures of Li[sub 2]Ti[sub 3]O[sub 7] have similar scavenging capacities for lithium. This report proposes a new mechanism for the phase transformation.

  11. Experimental and computational studies on stacking faults in zinc titanate

    SciTech Connect (OSTI)

    Sun, W.; Ageh, V.; Mohseni, H.; Scharf, T. W. E-mail: Jincheng.Du@unt.edu; Du, J. E-mail: Jincheng.Du@unt.edu

    2014-06-16

    Zinc titanate (ZnTiO{sub 3}) thin films grown by atomic layer deposition with ilmenite structure have recently been identified as an excellent solid lubricant, where low interfacial shear and friction are achieved due to intrafilm shear velocity accommodation in sliding contacts. In this Letter, high resolution transmission electron microscopy with electron diffraction revealed that extensive stacking faults are present on ZnTiO{sub 3} textured (104) planes. These growth stacking faults serve as a pathway for dislocations to glide parallel to the sliding direction and hence achieve low interfacial shear/friction. Generalized stacking fault energy plots also known as ?-surfaces were computed for the (104) surface of ZnTiO{sub 3} using energy minimization method with classical effective partial charge potential and verified by using density functional theory first principles calculations for stacking fault energies along certain directions. These two are in qualitative agreement but classical simulations generally overestimate the energies. In addition, the lowest energy path was determined to be along the [451{sup }] direction and the most favorable glide system is (104) ?451{sup }? that is responsible for the experimentally observed sliding-induced ductility.

  12. Nanoscale Strontium Titanate Photocatalysts for Overall Water Splitting

    SciTech Connect (OSTI)

    Townsend, Troy K.; Browning, Nigel D.; Osterloh, Frank

    2012-08-28

    SrTiO3 (STO) is a large band gap (3.2 eV) semiconductor that catalyzes the overall water splitting reaction under UV light irradiation in the presence of a NiO cocatalyst. As we show here, the reactivity persists in nanoscale particles of the material, although the process is less effective at the nanoscale. To reach these conclusions, Bulk STO, 30 5 nm STO, and 6.5 1 nm STO were synthesized by three different methods, their crystal structures verified with XRD and their morphology observed with HRTEM before and after NiO deposition. In connection with NiO, all samples split water into stoichiometric mixtures of H2 and O2, but the activity is decreasing from 28 ?mol H2 g1 h1 (bulk STO), to 19.4 ?mol H2 g1 h1 (30 nm STO), and 3.0 ?mol H2 g1 h1 (6.5 nm STO). The reasons for this decrease are an increase of the water oxidation overpotential for the smaller particles and reduced light absorption due to a quantum size effect. Overall, these findings establish the first nanoscale titanate photocatalyst for overall water splitting.

  13. COSMIC-RAY-MEDIATED FORMATION OF BENZENE ON THE SURFACE OF SATURN'S MOON TITAN

    SciTech Connect (OSTI)

    Zhou Li; Zheng Weijun; Kaiser, Ralf I.; Landera, Alexander; Mebel, Alexander M.; Liang, Mao-Chang; Yung, Yuk L.

    2010-08-01

    The aromatic benzene molecule (C{sub 6}H{sub 6})-a central building block of polycyclic aromatic hydrocarbon molecules-is of crucial importance for the understanding of the organic chemistry of Saturn's largest moon, Titan. Here, we show via laboratory experiments and electronic structure calculations that the benzene molecule can be formed on Titan's surface in situ via non-equilibrium chemistry by cosmic-ray processing of low-temperature acetylene (C{sub 2}H{sub 2}) ices. The actual yield of benzene depends strongly on the surface coverage. We suggest that the cosmic-ray-mediated chemistry on Titan's surface could be the dominant source of benzene, i.e., a factor of at least two orders of magnitude higher compared to previously modeled precipitation rates, in those regions of the surface which have a high surface coverage of acetylene.

  14. Highly aligned arrays of high aspect ratio barium titanate nanowires via hydrothermal synthesis

    SciTech Connect (OSTI)

    Bowland, Christopher C.; Zhou, Zhi; Malakooti, Mohammad H.; Sodano, Henry A.

    2015-06-01

    We report on the development of a hydrothermal synthesis procedure that results in the growth of highly aligned arrays of high aspect ratio barium titanate nanowires. Using a multiple step, scalable hydrothermal reaction, a textured titanium dioxide film is deposited on titanium foil upon which highly aligned nanowires are grown via homoepitaxy and converted to barium titanate. Scanning electron microscope images clearly illustrate the effect the textured film has on the degree of orientation of the nanowires. The alignment of nanowires is quantified by calculating the Herman's Orientation Factor, which reveals a 58% improvement in orientation as compared to growth in the absence of the textured film. The ferroelectric properties of barium titanate combined with the development of this scalable growth procedure provide a powerful route towards increasing the efficiency and performance of nanowire-based devices in future real-world applications such as sensing and power harvesting.

  15. Electronic excitation induced amorphization in titanate pyrochlores: an ab initio molecular dynamics study

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

    Xiao, Haiyan Y.; Weber, William J.; Zhang, Yanwen; Zu, X. T.; Li, Sean

    2015-02-09

    In this study, the response of titanate pyrochlores (A2Ti2O7, A = Y, Gd and Sm) to electronic excitation is investigated utilizing an ab initio molecular dynamics method. All the titanate pyrochlores are found to undergo a crystalline-to-amorphous structural transition under a low concentration of electronic excitations. The transition temperature at which structural amorphization starts to occur depends on the concentration of electronic excitations. During the structural transition, O2-like molecules are formed, and this anion disorder further drives cation disorder that leads to an amorphous state. This study provides new insights into the mechanisms of amorphization in titanate pyrochlores under laser,more » electron and ion irradiations.« less

  16. Silver decorated titanate/titania nanostructures for efficient solar driven photocatalysis

    SciTech Connect (OSTI)

    Gong, Dangguo; Ho, Weng Chye Jeffrey; Tang Yuxin; Tay Qiuling; Lai Yuekun; Highfield, James George; Chen Zhong

    2012-05-15

    Photocatalysis has attracted significant interest to solve both the energy crisis and effectively combat environmental contamination. However, as the most widely used photocatalyst, titania (TiO{sub 2}) suffers from inefficient utilization of solar energy due to its wide band gap. In the present paper, we describe a method to extend the absorption edge of photocatalyst to visible region by the surface plasmon effect of silver. Silver ions are photo-reduced onto the surface of titanate nanotubes, which are synthesized by a conventional hydrothermal method. The as-synthesized Ag/titanate composite is transformed into Ag/titania nanoparticles by annealing at different temperatures. It is found that the interaction of Ag nanoparticles with the supports (titanate/titania) plays a key role for the visible light activity. The samples annealed at low temperature (<350 Degree-Sign C) do not show significant activity under our conditions, while the one annealed at 450 Degree-Sign C shows fast-degradation of methyl orange (MO) under visible light irradiation. The detailed mechanisms are also discussed. - Graphical abstract: Silver nanoparticles decorated titanate/titania as visible light active photocatalysts: silver nanoparticles could be excited by visible light due to its surface plasmon effect and excited electrons could be transferred to the conduction band of the semiconductor, where the reduction process occurs. Highlights: Black-Right-Pointing-Pointer Uniform Ag nanoparticles are photo-reduced onto titanate and titania nanostructures. Black-Right-Pointing-Pointer Titania crystal is formed by annealing hydrogen titanate at different temperatures. Black-Right-Pointing-Pointer Best visible-light activity is achieved by Ag-loaded titania annealed at 450 Degree-Sign C. Black-Right-Pointing-Pointer The visible light activity is attributed to the surface plasmonic resonance effect.

  17. High-frequency fluctuation measurements by far-infrared laser Faraday-effect polarimetry-interferometry and forward scattering system on MST

    SciTech Connect (OSTI)

    Ding, W. X. Lin, L.; Brower, D. L.; Duff, J. R.

    2014-11-15

    Magnetic fluctuation-induced transport driven by global tearing modes has been measured by Faraday-effect polarimetry and interferometry (phase measurements) in the MST reversed field pinch. However, the role of small-scale broadband magnetic and density turbulence in transport remains unknown. In order to investigate broadband magnetic turbulence, we plan to upgrade the existing detector system by using planar-diode fundamental waveguide mixers optimized for high sensitivity. Initial tests indicate these mixers have ×10 sensitivity improvement compared to currently employed corner-cube Schottky-diode mixers and ×5 lower noise. Compact mixer design will allow us to resolve the wavenumbers up to k ∼ 1–2 cm{sup −1} for beam width w = 1.5 cm and 15 cm{sup −1} for beam width w = 2 mm. The system can also be used to measure the scattered signal (amplitude measurement) induced by both plasma density and magnetic fluctuations.

  18. THE INFLUENCE OF BENZENE AS A TRACE REACTANT IN TITAN AEROSOL ANALOGS

    SciTech Connect (OSTI)

    Trainer, Melissa G.; Sebree, Joshua A.; Heidi Yoon, Y.; Tolbert, Margaret A.

    2013-03-20

    Benzene has been detected in Titan's atmosphere by Cassini instruments, with concentrations ranging from sub-ppb in the stratosphere to ppm in the ionosphere. Sustained levels of benzene in the haze formation region could signify that it is an important reactant in the formation of Titan's organic aerosol. To date, there have not been laboratory investigations to assess the influence of benzene on aerosol properties. We report a laboratory study on the chemical composition of organic aerosol formed from C{sub 6}H{sub 6}/CH{sub 4}/N{sub 2} via far ultraviolet irradiation (120-200 nm). The compositional results are compared to those from aerosol generated by a more ''traditional Titan'' mixture of CH{sub 4}/N{sub 2}. Our results show that even a trace amount of C{sub 6}H{sub 6} (10 ppm) has significant impact on the chemical composition and production rates of organic aerosol. There are several pathways by which photolyzed benzene may react to form larger molecules, both with and without the presence of CH{sub 4}, but many of these reaction mechanisms are only beginning to be explored for the conditions at Titan. Continued work investigating the influence of benzene in aerosol growth will advance understanding of this previously unstudied reaction system.

  19. Attrition resistant, zinc titanate-containing, reduced sulfur sorbents and methods of use thereof

    DOE Patents [OSTI]

    Vierheilig, Albert A.; Gupta, Raghubir P.; Turk, Brian S.

    2006-06-27

    Reduced sulfur gas species (e.g., H.sub.2S, COS and CS.sub.2) are removed from a gas stream by compositions wherein a zinc titanate ingredient is associated with a metal oxide-aluminate phase material in the same particle species. Nonlimiting examples of metal oxides comprising the compositions include magnesium oxide, zinc oxide, calcium oxide, nickel oxide, etc.

  20. EVALUATION OF ALTERNATIVE FILTER MEDIA FOR THE ROTARY MICROFILTER, PHASE 2

    SciTech Connect (OSTI)

    Fowley, M.

    2012-07-31

    Testing was conducted at the Savannah River National Laboratory (SRNL) to investigate filter membrane performance in an effort to increase rotary microfilter (RMF) throughput. Membranes were tested in the SpinTek Filtration, Inc. Static Test Cell (STC), which permitted quick and easy testing of several different membranes. Testing consisted of 100 hours tests with two different slurry feeds, based on recommendations from the phase 1 testing. One feed contained Monosodium Titanate (MST) solids in a simulated salt solution. The other feed contained simulated sludge batch 6 (SB6) solids in a simulated salt solution. Five membranes were tested, one each from filter manufactures Pall and Porvair and three from the Oak Ridge National Laboratory (ORNL). The membrane from Pall is the current membrane used on the latest generation RMF. The Porvair membrane performed well in previous STC tests as well as one of the ORNL membranes. The other two membranes from ORNL were recently developed and not available for the previous STC test. The results indicate that the Porvair filter performed best with the MST slurry and the ORNL SVB6-1B filter performed best with the SB6 slurry. Difficulty was encountered with the ORNL filters due to their dimensional thickness, which was greater than the recommended filter thickness for the STC. The STC equipment was modified to complete the testing of the ORNL filters.

  1. Tank 49H salt batch supernate qualification for ARP/MCU

    SciTech Connect (OSTI)

    Nash, C. A.; Peters, T.; Fink, S.; Foster, T.

    2008-08-25

    This report covers the laboratory testing and analyses of Tank 49H Qualification Sample Sets A and C, performed in support of initial radioactive operations of Actinide Removal Process (ARP) and Modular Caustic-Side Solvent Extraction Unit (MCU). Major goals of this work include checking that Tank 49H was well mixed after the last receipt of Tank 23H, characterizing Tank 49H supernate after solids are settled so that its composition can be compared to waste acceptance and hazard criteria, verifying actinide and strontium adsorption with a small scale test using monosodium titanate (MST) and filtration, checking MCU solvent performance when applied to the liquid produced from MST contact, and verifying that in-tank settling after a minimum of 30 days was at least as good or better at reducing solids content after a Tank 49H to Tank 50H transfer occurred than what was observed in less time in the lab. The first four items were covered by Sample Set A. The fifth item was covered by Sample Set C, which had several analyses after compositing as required in the nuclear criticality safety evaluation (NCSE).

  2. IMPACT OF URANIUM AND THORIUM ON HIGH TIO2 CONCENTRATION NUCLEAR WASTE GLASSES

    SciTech Connect (OSTI)

    Fox, K.; Edwards, T.

    2012-01-11

    This study focused on the potential impacts of the addition of Crystalline Silicotitanate (CST) and Monosodium Titanate (MST) from the Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) glass waste form and the applicability of the DWPF process control models. MST from the Salt Waste Processing Facility (SWPF) is also considered in the study. The KT08-series of glasses was designed to evaluate any impacts of the inclusion of uranium and thorium in glasses containing the SCIX components. All but one of the study glasses were found to be amorphous by X-ray diffraction (XRD). One of the slowly cooled glasses contained a small amount of trevorite, which is typically found in DWPF-type glasses and had no practical impact on the durability of the glass. The measured Product Consistency Test (PCT) responses for the study glasses and the viscosities of the glasses were well predicted by the current DWPF models. No unexpected issues were encountered when uranium and thorium were added to the glasses with SCIX components.

  3. The TITAN Reversed-Field Pinch fusion reactor study: Scoping phase report

    SciTech Connect (OSTI)

    Not Available

    1987-01-01

    The TITAN research program is a multi-institutional effort to determine the potential of the Reversed-Field Pinch (RFP) magnetic fusion concept as a compact, high-power-density, and ''attractive'' fusion energy system from economic (cost of electricity, COE), environmental, and operational viewpoints. In particular, a high neutron wall loading design (18 MW/m/sup 2/) has been chosen as the reference case in order to quantify the issue of engineering practicality, to determine the physics requirements and plasma operating mode, to assess significant benefits of compact systems, and to illuminate the main drawbacks. The program has been divided into two phases, each roughly one year in length: the Scoping Phase and the Design Phase. During the scoping phase, the TITAN design team has defined the parameter space for a high mass power density (MPD) RFP reactor, and explored a variety of approaches to the design of major subsystems. Two major design approaches consistent with high MPD and low COE, the lithium-vanadium blanket design and aqueous loop-in-pool design, have been selected for more detailed engineering evaluation in the design phase. The program has retained a balance in its approach to investigating high MPD systems. On the one hand, parametric investigations of both subsystems and overall system performance are carried out. On the other hand, more detailed analysis and engineering design and integration are performed, appropriate to determining the technical feasibility of the high MPD approach to RFP fusion reactors. This report describes the work of the scoping phase activities of the TITAN program. A synopsis of the principal technical findings and a brief description of the TITAN multiple-design approach is given. The individual chapters on Plasma Physics and Engineering, Parameter Systems Studies, Divertor, Reactor Engineering, and Fusion Power Core Engineering have been cataloged separately.

  4. An investigation of aluminum titanate-spinel composites behavior in radiation

    SciTech Connect (OSTI)

    Cevikbas, G.; Tugrul, A. B.; Boyraz, T.; Buyuk, B.; Onen, U.

    2015-03-30

    In the present work, the radiation attenuation properties of Aluminum titanate (Al{sub 2}TiO{sub 5})-Spinel (MgAl{sub 2}O{sub 4}) ceramics composites were investigated. Al{sub 2}TiO{sub 5}-MgAl{sub 2}O{sub 4} ceramics composites which have different Al{sub 2}TiO{sub 5} percentages (0%, 5% and 10%) were produced and performed against gamma sources. Cs-137 and Co-60 were used as gamma radiation sources. Transmission technique was used in the experiments. The linear and mass attenuation coefficients of the samples were carried out for gamma radiation sources. The experimental results were compared with the theoretical mass attenuation coefficients which were calculated by using XCOM computer code. Increasing Al{sub 2}TiO{sub 5} percentage in the Aluminum titanate/ Spinel ceramics composites causes the higher linear and mass attenuation coefficients of the composites against Cs-137 and Co-60 gamma radioisotopes. Therefore Also theoretical mass attenuation coefficients are compatible with the experimental results. In conclusion, increasing the Aluminum titanate ratio in the Al{sub 2}TiO{sub 5}-MgAl{sub 2}O{sub 4} ceramics composites increases the gamma shielding property of the Al{sub 2}TiO{sub 5}-MgAl{sub 2}O{sub 4} ceramics for nuclear shielding applications.

  5. Composite solid oxide fuel cell anode based on ceria and strontium titanate

    DOE Patents [OSTI]

    Marina, Olga A.; Pederson, Larry R.

    2008-12-23

    An anode and method of making the same wherein the anode consists of two separate phases, one consisting of a doped strontium titanate phase and one consisting of a doped cerium oxide phase. The strontium titanate phase consists of Sr.sub.1-xM.sub.xTiO.sub.3-.delta., where M is either yttrium (Y), scandium (Sc), or lanthanum (La), where "x" may vary typically from about 0.01 to about 0.5, and where .delta. is indicative of some degree of oxygen non-stoichiometry. A small quantity of cerium may also substitute for titanium in the strontium titanate lattice. The cerium oxide consists of N.sub.yCe.sub.1-yO.sub.2-.delta., where N is either niobium (Nb), vanadium (V), antimony (Sb) or tantalum (Ta) and where "y" may vary typically from about 0.001 to about 0.1 and wherein the ratio of Ti in said first phase to the sum of Ce and N in the second phase is between about 0.2 to about 0.75. Small quantities of strontium, yttrium, and/or lanthanum may additionally substitute into the cerium oxide lattice. The combination of these two phases results in better performance than either phase used separately as an anode for solid oxide fuel cell or other electrochemical device.

  6. A study of thermal properties of sodium titanate nanotubes synthesized by microwave-assisted hydrothermal method

    SciTech Connect (OSTI)

    Preda, Silviu; Rutar, Melita; Umek, Polona; Zaharescu, Maria

    2015-11-15

    Highlights: • The microwave-assisted hydrothermal route was used for titanate nanotubes synthesis. • Conversion to single-phase nanotube morphology completes after 8 h reaction time. • The nanotube morphology is stable up to 600 °C, as determined by in-situ XRD and SEM. • Sodium ions migrate to the surface due to thermal motion and structure condensation. - Abstract: Sodium titanate nanotubes (NaTiNTs) were synthesized by microwave-assisted hydrothermal treatment of commercial TiO{sub 2}, at constant temperature (135 °C) and different irradiation times (15 min, 1, 4, 8 and 16 h). The products were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, differential scanning calorimetry and specific surface area measurements. The irradiation time turned out to be the key parameter for morphological control of the material. Nanotubes were observed already after 15 min of microwave irradiation. The analyses of the products irradiated for 8 and 16 h confirm the complete transformation of the starting TiO{sub 2} powder to NaTiNTs. The nanotubes are open ended with multi-wall structures, with the average outer diameter of 8 nm and specific surface area up to 210 m{sup 2}/g. The morphology, surface area and crystal structure of the sodium titanate nanotubes synthesized by microwave-assisted hydrothermal method were similar to those obtained by conventional hydrothermal method.

  7. Electronic excitation induced amorphization in titanate pyrochlores: an ab initio molecular dynamics study

    SciTech Connect (OSTI)

    Xiao, Haiyan Y.; Weber, William J.; Zhang, Yanwen; Zu, X. T.; Li, Sean

    2015-02-09

    In this study, the response of titanate pyrochlores (A2Ti2O7, A = Y, Gd and Sm) to electronic excitation is investigated utilizing an ab initio molecular dynamics method. All the titanate pyrochlores are found to undergo a crystalline-to-amorphous structural transition under a low concentration of electronic excitations. The transition temperature at which structural amorphization starts to occur depends on the concentration of electronic excitations. During the structural transition, O2-like molecules are formed, and this anion disorder further drives cation disorder that leads to an amorphous state. This study provides new insights into the mechanisms of amorphization in titanate pyrochlores under laser, electron and ion irradiations.

  8. ACTINIDE REMOVAL PROCESS SAMPLE ANALYSIS, CHEMICAL MODELING, AND FILTRATION EVALUATION

    SciTech Connect (OSTI)

    Martino, C.; Herman, D.; Pike, J.; Peters, T.

    2014-06-05

    Filtration within the Actinide Removal Process (ARP) currently limits the throughput in interim salt processing at the Savannah River Site. In this process, batches of salt solution with Monosodium Titanate (MST) sorbent are concentrated by crossflow filtration. The filtrate is subsequently processed to remove cesium in the Modular Caustic Side Solvent Extraction Unit (MCU) followed by disposal in saltstone grout. The concentrated MST slurry is washed and sent to the Defense Waste Processing Facility (DWPF) for vitrification. During recent ARP processing, there has been a degradation of filter performance manifested as the inability to maintain high filtrate flux throughout a multi-batch cycle. The objectives of this effort were to characterize the feed streams, to determine if solids (in addition to MST) are precipitating and causing the degraded performance of the filters, and to assess the particle size and rheological data to address potential filtration impacts. Equilibrium modelling with OLI Analyzer{sup TM} and OLI ESP{sup TM} was performed to determine chemical components at risk of precipitation and to simulate the ARP process. The performance of ARP filtration was evaluated to review potential causes of the observed filter behavior. Task activities for this study included extensive physical and chemical analysis of samples from the Late Wash Pump Tank (LWPT) and the Late Wash Hold Tank (LWHT) within ARP as well as samples of the tank farm feed from Tank 49H. The samples from the LWPT and LWHT were obtained from several stages of processing of Salt Batch 6D, Cycle 6, Batch 16.

  9. THE ROLE OF METHANOL IN THE CRYSTALLIZATION OF TITAN'S PRIMORDIAL OCEAN

    SciTech Connect (OSTI)

    Deschamps, Frederic; Mousis, Olivier; Lunine, Jonathan I.

    2010-12-01

    A key parameter that controls the crystallization of primordial oceans in large icy moons is the presence of anti-freeze compounds, which may have maintained primordial oceans over the age of the solar system. Here we investigate the influence of methanol, a possible anti-freeze candidate, on the crystallization of Titan's primordial ocean. Using a thermodynamic model of the solar nebula and assuming a plausible composition of its initial gas phase, we first calculate the condensation sequence of ices in Saturn's feeding zone, and show that in Titan's building blocks methanol can have a mass fraction of {approx}4 wt% relative to water, i.e., methanol can be up to four times more abundant than ammonia. We then combine available data on the phase diagram of the water-methanol system and scaling laws derived from thermal convection to estimate the influence of methanol on the dynamics of the outer ice I shell and on the heat transfer through this layer. For a fraction of methanol consistent with the building blocks composition we determined, the vigor of convection in the ice I shell is strongly reduced. The effect of 5 wt% methanol is equivalent to that of 3 wt% ammonia. Thus, if methanol is present in the primordial ocean of Titan, the crystallization may stop, and a sub-surface ocean may be maintained between the ice I and high-pressure ice layers. A preliminary estimate indicates that the presence of 4 wt% methanol and 1 wt% ammonia may result in an ocean of thickness at least 90 km.

  10. Structural and crystal chemical properties of rare-earth titanate pyrochlores

    SciTech Connect (OSTI)

    Farmer, James Matthew; Boatner, Lynn A; Chakoumakos, Bryan C; Du, Mao-Hua; Lance, Michael J; Rawn, Claudia J.; Bryan, Jeff C.

    2014-01-01

    Rare-earth titanates, RE2Ti2O7 (where RE = a rare-earth) with the pyrochlore structure continue to be investigated for use as potential stable host materials for nuclear and actinide-rich wastes. Accordingly, the present work is directed towards the elucidation of the fundamental structural, physical, and thermochemical properties of this class of compounds. Single-crystals of the rare earth pyrochlores were synthesized using a high-temperature flux technique and were subsequently characterized using single-crystal X-ray diffraction. The cubic lattice parameters display an approximately linear correlation with the RE-site cation radius. Theoretical calculations of the lattice constants and bond lengths of the subject materials were carried out using density functional theory, and the results are compared to the experimental values. The Sm and Eu titanates exhibit a covalency increase between the REO8 and TiO6 polyhedra resulting in a deviation from the increasing linear lattice parameter through the transition series. Gd2Ti2O7 with the 4f7 half-filled f-orbital Gd3+ sub-shell exhibits the lowest 48f oxygen positional parameter. The coefficient of thermal expansion for the rare-earth titanate series is approximately linear, and it has a range of 10.1 11.2 x 10-6 C-1. Raman spectroscopy indicated that the ~530 cm-1 peak associated with the Ti-O stretching mode follows a general trend of decreasing frequency with increasing RE reduced mass.

  11. Comparative study of broadband electrodynamic properties of single-crystal and thin-film strontium titanate

    SciTech Connect (OSTI)

    Findikoglu, A. T.; Jia, Q. X.; Kwon, C.; Reagor, D. W.; Kaduchak, G.; Rasmussen, K. Oe.; Bishop, A. R.

    1999-12-27

    We have used a coplanar waveguide structure to study broadband electrodynamic properties of single-crystal and thin-film strontium titanate. We have incorporated both time- and frequency-domain measurements to determine small-signal effective refractive index and loss tangent as functions of frequency (up to 4 GHz), dc bias (up to 10{sup 6} V/m), and cryogenic temperature (17 and 60 K). The large-signal impulse response of the devices and the associated phenomenological nonlinear wave equation illustrate how dissipation and nonlinearity combine to produce the overall response in the large-signal regime. (c) 1999 American Institute of Physics.

  12. Fluidizable zinc titanate materials with high chemical reactivity and attrition resistance

    DOE Patents [OSTI]

    Gupta, R.P.; Gangwal, S.K.; Jain, S.C.

    1993-10-19

    Highly durable and chemically reactive zinc titanate materials are prepared in a particle size range of 50 to 400 [mu]m suitable for a fluidized-bed reactor for removing reduced sulfur species in a gaseous form by granulating a mixture of fine zinc oxide and titanium oxide with inorganic and organic binders and by optional additions of small amounts of activators such as CoO and MoO[sub 3]; and then indurating it at 800 to 900 C for a time sufficient to produce attrition-resistant granules.

  13. Effect of samarium doping on the dielectric behavior of barium zircomium titanate ceramic

    SciTech Connect (OSTI)

    Badapanda, T.; Sarangi, S.; Behera, B.; Anwar, S.; Sinha, T. P.

    2014-04-24

    Samarium doped Barium Zirconium Titanate ceramic with general formula Ba{sub 1?x}Sm{sub 2x/3}Zr{sub 0.05}Ti{sub 0.95}O{sub 3} [x=0.0,0.01,0.02,0.03,0.04] has been prepared by high energy ball milling. The X-ray diffraction (XRD) patterns confirmed that these ceramics have a single phase with perovskite-type upto x?0.03 and a small secondary phase exist at x=0.04. The temperature dependent dielectric study shows a ferroelectric phase transition and transition temperature decreases with an increase in the Samarium content.

  14. Fluidizable zinc titanate materials with high chemical reactivity and attrition resistance

    DOE Patents [OSTI]

    Gupta, Raghubir P.; Gangwal, Santosh K.; Jain, Suresh C.

    1993-01-01

    Highly durable and chemically reactive zinc titanate materials are prepared in a particle size range of 50 to 400 .mu.m suitable for a fluidized-bed reactor for removing reduced sulfur species in a gaseous form by granulating a mixture of fine zinc oxide and titanium oxide with inorganic and organic binders and by optional additions of small amounts of activators such as CoO and MoO.sub.3 ; and then indurating it at 800.degree. to 900.degree. C. for a time sufficient to produce attrition-resistant granules.

  15. Nitrogen-sensitized dual phase titanate/titania for visible-light driven phenol degradation

    SciTech Connect (OSTI)

    Cheng, Yu Hua; Subramaniam, Vishnu P.; Gong, Dangguo; Tang, Yuxin; Highfield, James; Pehkonen, Simo O.; Pichat, Pierre; Chen, Zhong

    2012-12-15

    A dual-phase material (DP-160) comprising hydrated titanate (H{sub 2}Ti{sub 3}O{sub 7}{center_dot}xH{sub 2}O) and anatase (TiO{sub 2}) was synthesized in a low-temperature one-pot process in the presence of triethylamine (TEA) as the N-source. The unique structure exhibits strong visible light absorption. The chromophore is linked to Ti-N bonds derived from both surface sensitization and sub-surface (bulk) doping. From transmission electron microscope (TEM) and textural studies by N{sub 2} physisorption, the composite exists as mesoporous particles with a grain size of {approx}20 nm and mean pore diameter of 3.5 nm, responsible for the high surface area ({approx}180 m{sup 2}/g). DP-160 demonstrated photocatalytic activity in the degradation of phenol under visible light ({lambda}>420 nm). The activity of the composite was further enhanced by a small addition (0.001 M) of H{sub 2}O{sub 2}, which also gave rise to some visible light activity in the control samples. This effect is believed to be associated with the surface peroxo-titanate complex. GC-MS analyses showed that the intermediate products of phenol degradation induced by visible light irradiation of DP-160 did not differ from those obtained by UV (band-gap) irradiation of TiO{sub 2}. The overall performance of the composite is attributed to efficient excitation via inter-band states (due to N-doping), surface sensitization, improved adsorptive properties of aromatic compounds due to the N-carbonaceous overlayer, and the presence of heterojunctions that are known to promote directional charge transfer in other mixed-phase titanias like Degussa P25. - graphical abstract: Nitrogen-sensitized dual phase titanate/titania photocatalyst showing extended visible light absorption and efficient photocatalytic degradation of phenol. Highlights: Black-Right-Pointing-Pointer Low temperature one-pot synthesis of visible light active dual phase photocatalyst. Black-Right-Pointing-Pointer The dual phase consists of

  16. A TRANSMISSION SPECTRUM OF TITAN'S NORTH POLAR ATMOSPHERE FROM A SPECULAR REFLECTION OF THE SUN

    SciTech Connect (OSTI)

    Barnes, Jason W.; Clark, Roger N.; Sotin, Christophe; Buratti, Bonnie J.; dmkovics, Mt; Appr, Thomas; Rodriguez, Sebastien; Brown, Robert H.; Baines, Kevin H.; Le Moulic, Stphane; Nicholson, Philip D.

    2013-11-10

    Cassini/VIMS T85 observations of a solar specular reflection off of Kivu Lacus (87.4N 241.1E) provide an empirical transmission spectrum of Titan's atmosphere. Because this observation was acquired from short range (33,000 km), its intensity makes it visible within the 2.0, 2.7, and 2.8 ?m atmospheric windows in addition to the 5 ?m window where all previous specular reflections have been seen. The resulting measurement of the total one-way normal atmospheric optical depth (corresponding to haze scattering plus haze and gas absorption) provides strong empirical constraints on radiative transfer models. Using those models, we find that the total haze column abundance in our observation is 20% higher than the Huygens equatorial value. Ours is the first measurement in the 2-5 ?m wavelength range that probes all the way to the surface in Titan's arctic, where the vast majority of surface liquids are located. The specular technique complements other probes of atmospheric properties such as solar occultations and the direct measurements from Huygens. In breaking the degeneracy between surface and atmospheric absorptions, our measured optical depths will help to drive future calculations of deconvolved surface albedo spectra.

  17. Visible light carrier generation in co-doped epitaxial titanate films

    SciTech Connect (OSTI)

    Comes, Ryan B.; Smolin, Sergey Y.; Kaspar, Tiffany C.; Gao, Ran; Apgar, Brent A.; Martin, Lane W.; Bowden, Mark E.; Baxter, Jason; Chambers, Scott A.

    2015-03-02

    Perovskite titanates such as SrTiO3 (STO) exhibit a wide range of important functional properties, including high electron mobility, ferroelectricitywhich may be valuable in photovoltaic applicationsand excellent photocatalytic performance. The wide optical band gap of titanates limits their use in these applications, however, making them ill-suited for integration into solar energy harvesting technologies. Our recent work has shown that by doping STO with equal concentrations of La and Cr we can enhance visible light absorption in epitaxial thin films while avoiding any compensating defects. In this work, we explore the optical properties of photoexcited carriers in these films. Using spectroscopic ellipsometry, we show that the Cr3+ dopants, which produce electronic states immediately above the top of the O 2p valence band in STO reduce the direct band gap of the material from 3.75 eV to between 2.4 and 2.7 eV depending on doping levels. Transient reflectance measurements confirm that optically generated carriers have a recombination lifetime comparable to that of STO and are in agreement with the observations from ellipsometry. Finally, through photoelectrochemical yield measurements, we show that these co-doped films exhibit enhanced visible light photocatalysis when compared to pure STO.

  18. Visible light carrier generation in co-doped epitaxial titanate films

    SciTech Connect (OSTI)

    Comes, Ryan B. Kaspar, Tiffany C.; Chambers, Scott A.; Smolin, Sergey Y.; Baxter, Jason B.; Gao, Ran; Apgar, Brent A.; Martin, Lane W.; Bowden, Mark E.

    2015-03-02

    Perovskite titanates such as SrTiO{sub 3} (STO) exhibit a wide range of important functional properties, including ferroelectricity and excellent photocatalytic performance. The wide optical band gap of titanates limits their use in these applications; however, making them ill-suited for integration into solar energy harvesting technologies. Our recent work has shown that by doping STO with equal concentrations of La and Cr, we can enhance visible light absorption in epitaxial thin films while avoiding any compensating defects. In this work, we explore the optical properties of photoexcited carriers in these films. Using spectroscopic ellipsometry, we show that the Cr{sup 3+} dopants, which produce electronic states immediately above the top of the O 2p valence band in STO reduce the direct band gap of the material from 3.75?eV to 2.42.7?eV depending on doping levels. Transient reflectance spectroscopy measurements are in agreement with the observations from ellipsometry and confirm that optically generated carriers are present for longer than 2?ns. Finally, through photoelectrochemical methylene blue degradation measurements, we show that these co-doped films exhibit enhanced visible light photocatalysis when compared to pure STO.

  19. PHOTODISSOCIATION OF THE DIACETYLENE DIMER AND IMPLICATIONS FOR HYDROCARBON GROWTH IN TITAN'S ATMOSPHERE

    SciTech Connect (OSTI)

    Huang Cunshun; Silva, Ruchira; Gichuhi, Wilson K.; Suits, Arthur G.; Zhang Fangtong; Kaiser, Ralf I.; Kislov, Vadim V.; Mebel, Alexander M.

    2010-05-10

    The surface of Titan is obscured by multiple aerosol layers whose composition and formation mechanism have remained poorly understood. These organic haze layers are believed to arise from photolysis and electron impact triggered chemistry in the dense nitrogen (N{sub 2}) and methane (CH{sub 4}) atmosphere involving highly unsaturated hydrocarbon molecules such as acetylene (HCCH), diacetylene (HCCCCH), and triacetylene (HCCCCCCH). Here we show via laboratory studies combined with electronic structure calculations that the photodissociation of the diacetylene dimer ((HCCCCH){sub 2}) readily initiates atomic hydrogen loss and atomic hydrogen transfer reactions forming two prototypes of resonantly stabilized free radicals, C{sub 4}H{sub 3} and C{sub 8}H{sub 3}, respectively. These structures represent hydrogenated polyynes which can neither be synthesized via traditional photodissociation pathways of the monomer nor via hydrogen addition to the polyynes. The photodissociation dynamics of mixed dimers involving acetylene, diacetylene, and even triacetylene present a novel, hitherto overlooked reaction class and show the potential to synthesize more complex, resonantly stabilized free radicals considered to be major building blocks to polycyclic aromatic hydrocarbons in Titan's low-temperature atmosphere.

  20. Method for making fine and ultrafine spherical particles of zirconium titanate and other mixed metal oxide systems

    DOE Patents [OSTI]

    Hu, Michael Z.

    2006-05-23

    Disclosed is a method for making amorphous spherical particles of zirconium titanate and crystalline spherical particles of zirconium titanate comprising the steps of mixing an aqueous solution of zirconium salt and an aqueous solution of titanium salt into a mixed solution having equal moles of zirconium and titanium and having a total salt concentration in the range from 0.01 M to about 0.5 M. A stearic dispersant and an organic solvent is added to the mixed salt solution, subjecting the zirconium salt and the titanium salt in the mixed solution to a coprecipitation reaction forming a solution containing amorphous spherical particles of zirconium titanate wherein the volume ratio of the organic solvent to aqueous part is in the range from 1 to 5. The solution of amorphous spherical particles is incubated in an oven at a temperature .ltoreq.100.degree. C. for a period of time .ltoreq.24 hours converting the amorphous particles to fine or ultrafine crystalline spherical particles of zirconium titanate.

  1. Tour - MST - UW Plasma Physics

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

    Total Energy Glossary › FAQS › Overview Data Monthly Annual Analysis & Projections Major Topics Most popular Annual Monthly Projections Recurring U.S. States All reports Browse by Tag Alphabetical Frequency Tag Cloud Current Issues & Trends See more › Composition of trade influences goods output, shaping industrial sector energy intensity exportsimportsindustrialAEO2016 Changing U.S. energy mix reflects growing use of natural gas, petroleum, and renewables natural

  2. Microstructural, dielectric and magnetic properties of multiferroic composite system barium strontium titanate nickel cobalt ferrite

    SciTech Connect (OSTI)

    Pahuja, Poonam Tandon, R. P.

    2015-05-15

    Multiferroic composites (1-x) Ba{sub 0.95}Sr{sub 0.05}TiO{sub 3} + (x) Ni{sub 0.8}Co{sub 0.2}Fe{sub 2}O{sub 4} (where x = 0.1, 0.2, 0.3, 0.4) has been prepared by solid state reaction method. X-ray diffraction analysis of the composite samples confirmed the presence of both barium strontium titanate (BST) and nickel cobalt ferrite (NCF) phases. FESEM images indicated the well dispersion of NCF grains among BST grains. Dielectric constant and loss of the composite samples decreases with increase in frequency following Maxwell-Wagner relaxation mechanism. Composite sample with highest ferrite content possesses highest values of remanent and saturation magnetization.

  3. High temperature dielectric relaxation anomaly of Y? and Mn? doped barium strontium titanate ceramics

    SciTech Connect (OSTI)

    Yan, Shiguang; Mao, Chaoliang E-mail: xldong@mail.sic.ac.cn; Wang, Genshui; Yao, Chunhua; Cao, Fei; Dong, Xianlin E-mail: xldong@mail.sic.ac.cn

    2014-10-14

    Relaxation like dielectric anomaly is observed in Y? and Mn? doped barium strontium titanate ceramics when the temperature is over 450 K. Apart from the conventional dielectric relaxation analysis method with Debye or modified Debye equations, which is hard to give exact temperature dependence of the relaxation process, dielectric response in the form of complex impedance, assisted with Cole-Cole impedance model corrected equivalent circuits, is adopted to solve this problem and chase the polarization mechanism in this paper. Through this method, an excellent description to temperature dependence of the dielectric relaxation anomaly and its dominated factors are achieved. Further analysis reveals that the exponential decay of the Cole distribution parameter n with temperature is confirmed to be induced by the microscopic lattice distortion due to ions doping and the interaction between the defects. At last, a clear sight to polarization mechanism containing both the intrinsic dipolar polarization and extrinsic distributed oxygen vacancies hopping response under different temperature is obtained.

  4. Accurate spectroscopic characterization of protonated oxirane: a potential prebiotic species in Titan's atmosphere

    SciTech Connect (OSTI)

    Puzzarini, Cristina; Ali, Ashraf; Biczysko, Malgorzata; Barone, Vincenzo

    2014-09-10

    An accurate spectroscopic characterization of protonated oxirane has been carried out by means of state-of-the-art computational methods and approaches. The calculated spectroscopic parameters from our recent computational investigation of oxirane together with the corresponding experimental data available were used to assess the accuracy of our predicted rotational and IR spectra of protonated oxirane. We found an accuracy of about 10 cm{sup –1} for vibrational transitions (fundamentals as well as overtones and combination bands) and, in relative terms, of 0.1% for rotational transitions. We are therefore confident that the spectroscopic data provided herein are a valuable support for the detection of protonated oxirane not only in Titan's atmosphere but also in the interstellar medium.

  5. Elaboration and characterization of doped barium titanate films for gas sensing

    SciTech Connect (OSTI)

    Romh, M. A. El Fasquelle, D. Mascot, M.; Dputier, S.

    2014-11-05

    Barium titanate (BaTiO{sub 3}) thick films were prepared from commercial powder to develop and optimize the film elaboration. Then, BaTiO{sub 3} was doped by strontium and iron to increase the conductivity by a double substitution on site A and B of the perovskite structure in view to develop semiconductor gas sensors. Film inks were prepared by mixing BT and BSTF powder with an organic vehicle, using a ratio of 50:50; 60:40, respectively and deposited on alumina substrates. The BT and BSTF films were sintered at 1100C for 2h. The structural and physical properties of the films have been studied by using X-ray diffraction (XRD) and scanning electron microscope (SEM). The dielectric measurements showed a huge increase in the a.c. conductivity for the BSTF films, by a factor of 10000 at low frequency, when the temperature ranges from 25C to 500C.

  6. Blocking effect of crystalglass interface in lanthanum doped barium strontium titanate glassceramics

    SciTech Connect (OSTI)

    Wang, Xiangrong; Zhang, Yong; Baturin, Ivan; Liang, Tongxiang

    2013-10-15

    Graphical abstract: The blocking effect of the crystalglass interface on the carrier transport behavior in the lanthanum doped barium strontium titanate glassceramics: preparation and characterization. - Highlights: La{sub 2}O{sub 3} addition promotes the crystallization of the major crystalline phase. The Z? and M? peaks exist a significant mismatch for 0.5 mol% La{sub 2}O{sub 3} addition. The Z? and M? peaks separate obviously for 1.0 mol% La{sub 2}O{sub 3} addition. Crystallite impedance decreases while crystalglass interface impedance increases. La{sub 2}O{sub 3} addition increases blocking factor of the crystalglass interface. - Abstract: The microstructures and dielectric properties in La{sub 2}O{sub 3}-doped barium strontium titanate glassceramics have been investigated by scanning electron microscopy (SEM) and impedance spectroscopy. SEM analysis indicated that La{sub 2}O{sub 3} additive decreases the average crystallite size. Impedance spectroscopy revealed that the positions of Z? and M? peaks are close for undoped samples. When La{sub 2}O{sub 3} concentration is 0.5 mol%, the Z? and M? peaks show a significant mismatch. Furthermore, these peaks separate obviously for 1.0 mol% La{sub 2}O{sub 3} addition. With increasing La{sub 2}O{sub 3} concentration, the contribution of the crystallite impedance becomes smaller, while the contribution of the crystalglass interface impedance becomes larger. More interestingly, it was found that La{sub 2}O{sub 3} additive increases blocking factor of the crystalglass interface in the temperature range of 250450 C. This may be attributed to a decrease of activation energy of the crystallite and an increase of the crystalglass interface area.

  7. On the sol-gel synthesis of strontium-titanate thin films and the prospects of their use in electronics

    SciTech Connect (OSTI)

    Sohrabi Anaraki, H.; Gaponenko, N. V. Rudenko, M. V.; Guk, A. F.; Zavadskij, S. M.; Golosov, D. A.; Kolosnitsyn, B. S.; Kolos, V. V.; Pyatlitskij, A. N.; Turtsevich, A. S.

    2014-12-15

    Strontium-titanate films obtained by the sol-gel technique are deposited onto silicon and silicon/oxide titanium/platinum substrates. The strontium-titanate phase is detected by the method of X-ray diffraction analysis after heat treatment at temperatures of 750 and 800°C. The thickness of the films obtained by the spin-on method increases from 50 to 250 nm as the number of deposited layers is increased and is accompanied with an increase in the grain size in the films. Prospects of the development of the sol-gel technique for the formation of film components of electronic devices based on SrTiO{sub 3} xerogels are discussed.

  8. Cerium-modified doped strontium titanate compositions for solid oxide fuel cell anodes and electrodes for other electrochemical devices

    DOE Patents [OSTI]

    Marina, Olga A [Richland, WA; Stevenson, Jeffry W [Richland, WA

    2010-11-23

    The present invention provides novel compositions that find advantageous use in making electrodes for electrochemical cells and electrochemical devices such as solid oxide fuel cells, electrolyzers, sensors, pumps and the like, the compositions comprising cerium-modified doped strontium titanate. The invention also provides novel methods for making and using anode material compositions and solid oxide fuel cells and solid oxide fuel cell assemblies having anodes comprising the compositions.

  9. Cerium-modified doped strontium titanate compositions for solid oxide fuel cell anodes and electrodes for other electrochemical devices

    DOE Patents [OSTI]

    Marina, Olga A [Richland, WA; Stevenson, Jeffry W [Richland, WA

    2010-03-02

    The present invention provides novel compositions that find advantageous use in making electrodes for electrochemical cells and electrochemical devices such as solid oxide fuel cells, electrolyzers, sensors, pumps and the like, the compositions comprising cerium-modified doped strontium titanate. The invention also provides novel methods for making and using anode material compositions and solid oxide fuel cells and solid oxide fuel cell assemblies having anodes comprising the compositions.

  10. LABORATORY STUDIES ON THE IRRADIATION OF SOLID ETHANE ANALOG ICES AND IMPLICATIONS TO TITAN'S CHEMISTRY

    SciTech Connect (OSTI)

    Kim, Y. S.; Bennett, C. J.; Chen, L-H; Kaiser, R. I.; O'Brien, K.

    2010-03-10

    Pure ethane ices (C{sub 2}H{sub 6}) were irradiated at 10, 30, and 50 K under contamination-free, ultrahigh vacuum conditions with energetic electrons generated in the track of galactic cosmic-ray (GCR) particles to simulate the interaction of GCRs with ethane ices in the outer solar system. The chemical processing of the samples was monitored by a Fourier transform infrared spectrometer and a quadrupole mass spectrometer during the irradiation phase and subsequent warm-up phases on line and in situ in order to extract qualitative (products) and quantitative (rate constants and yields) information on the newly synthesized molecules. Six hydrocarbons, methane (CH{sub 4}), acetylene (C{sub 2}H{sub 2}), ethylene (C{sub 2}H{sub 4}), and the ethyl radical (C{sub 2}H{sub 5}), together with n-butane (C{sub 4}H{sub 10}) and butene (C{sub 4}H{sub 8}), were found to form at the radiation dose reaching 1.4 eV per molecule. The column densities of these species were quantified in the irradiated ices at each temperature, permitting us to elucidate the temperature and phase-dependent production rates of individual molecules. A kinetic reaction scheme was developed to fit column densities of those species produced during irradiation of amorphous/crystalline ethane held at 10, 30, or 50 K. In general, the yield of the newly formed molecules dropped consistently for all species as the temperature was raised from 10 K to 50 K. Second, the yield in the amorphous samples was found to be systematically higher than in the crystalline samples at constant temperature. A closer look at the branching ratios indicates that ethane decomposes predominantly to ethylene and molecular hydrogen, which may compete with the formation of n-butane inside the ethane matrix. Among the higher molecular products, n-butane dominates. Of particular relevance to the atmosphere of Saturn's moon Titan is the radiation-induced methane production from ethane-an alternative source of replenishing methane into the

  11. SCIX IMPACT ON DWPF CPC

    SciTech Connect (OSTI)

    Koopman, D.

    2011-07-14

    A program was conducted to systematically evaluate potential impacts of the proposed Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) Chemical Processing Cell (CPC). The program involved a series of interrelated tasks. Past studies of the impact of crystalline silicotitanate (CST) and monosodium titanate (MST) on DWPF were reviewed. Paper studies and material balance calculations were used to establish reasonable bounding levels of CST and MST in sludge. Following the paper studies, Sludge Batch 10 (SB10) simulant was modified to have both bounding and intermediate levels of MST and ground CST. The SCIX flow sheet includes grinding of the CST which is larger than DWPF frit when not ground. Nominal ground CST was not yet available, therefore a similar CST ground previously in Savannah River National Laboratory (SRNL) was used. It was believed that this CST was over ground and that it would bound the impact of nominal CST on sludge slurry properties. Lab-scale simulations of the DWPF CPC were conducted using SB10 simulants with no, intermediate, and bounding levels of CST and MST. Tests included both the Sludge Receipt and Adjustment Tank (SRAT) and Slurry Mix Evaporator (SME) cycles. Simulations were performed at high and low acid stoichiometry. A demonstration of the extended CPC flowsheet was made that included streams from the site interim salt processing operations. A simulation using irradiated CST and MST was also completed. An extensive set of rheological measurements was made to search for potential adverse consequences of CST and MST and slurry rheology in the CPC. The SCIX CPC impact program was conducted in parallel with a program to evaluate the impact of SCIX on the final DWPF glass waste form and on the DWPF melter throughput. The studies must be considered together when evaluating the full impact of SCIX on DWPF. Due to the fact that the alternant flowsheet for DWPF has not been selected, this study did not

  12. SAMPLE RESULTS FROM THE INTEGRATED SALT DISPOSITION PROGRAM MACROBATCH 4 TANK 21H QUALIFICATION SAMPLES

    SciTech Connect (OSTI)

    Peters, T.; Fink, S.

    2011-06-22

    Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H to qualify them for use in the Integrated Salt Disposition Program (ISDP) Batch 4 processing. All sample results agree with expectations based on prior analyses where available. No issues with the projected Salt Batch 4 strategy are identified. This revision includes additional data points that were not available in the original issue of the document, such as additional plutonium results, the results of the monosodium titanate (MST) sorption test and the extraction, scrub strip (ESS) test. This report covers the revision to the Tank 21H qualification sample results for Macrobatch (Salt Batch) 4 of the Integrated Salt Disposition Program (ISDP). A previous document covers initial characterization which includes results for a number of non-radiological analytes. These results were used to perform aluminum solubility modeling to determine the hydroxide needs for Salt Batch 4 to prevent the precipitation of solids. Sodium hydroxide was then added to Tank 21 and additional samples were pulled for the analyses discussed in this report. This work was specified by Task Technical Request and by Task Technical and Quality Assurance Plan (TTQAP).

  13. SAMPLE RESULTS FROM THE INTERIM SALT DISPOSITION PROGRAM MACROBATCH 8 TANK 21H QUALIFICATION SAMPLES

    SciTech Connect (OSTI)

    Peters, T. B.; Washington, A. L.

    2015-01-13

    Savannah River National Laboratory (SRNL) analyzed samples from Tank 21H in support of qualification of Macrobatch (Salt Batch) 8 for the Interim Salt Disposition Program (ISDP). An Actinide Removal Process (ARP) and several Extraction-Scrub- Strip (ESS) tests were also performed. This document reports characterization data on the samples of Tank 21H as well as simulated performance of ARP and the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU). No issues with the projected Salt Batch 8 strategy are identified. A demonstration of the monosodium titanate (MST) (0.2 g/L) removal of strontium and actinides provided acceptable average decontamination factors for plutonium of 2.62 (4 hour) and 2.90 (8 hour); and average strontium decontamination factors of 21.7 (4 hour) and 21.3 (8 hour). These values are consistent with results from previous salt batch ARP tests. The two ESS tests also showed acceptable performance with extraction distribution ratios (D{sub (Cs)}) values of 52.5 and 50.4 for the Next Generation Solvent (NGS) blend (from MCU) and NGS (lab prepared), respectively. These values are consistent with results from previous salt batch ESS tests. Even though the performance is acceptable, SRNL recommends that a model for predicting extraction behavior for cesium removal for the blended solvent and NGS be developed in order to improve our predictive capabilities for the ESS tests.

  14. Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling

    SciTech Connect (OSTI)

    Wang, Hong; Lee, Sung Min; Wang, James L.; Lin, Hua-Tay

    2014-12-19

    Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 10^8 cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and the fatigue index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications such as piezoelectric fuel injectors in heavy-duty diesel engines.

  15. Hexagonal phase transformation in the engineered scavenger compound lithium titanate. Report of Investigations/1993

    SciTech Connect (OSTI)

    Collins, W.K.; Riley, W.D.; Jong, B.W.

    1993-01-01

    Engineered scavenger compounds (ESC's) developed by the US Bureau of Mines are a novel class of compounds that selectively can recover a desired element from a solid or molten alloy. Lithium titanate (Li2Ti3O7 or Li2O center dot 3TiO2) is used as an ESC to recover lithium (Li) from aluminum-lithium (Al-Li) alloys. X-ray diffraction measurements have shown that Li2Ti3O7 undergoes a phase change during scavenging from an orthorhombic structure to a hexagonal structure. This change is due to the incorporation of lithium in the matrix of the material and the effect of temperature. Although both phases are metastable, the hexagonal phase that forms during the scavenging of lithium from Al-Li alloys appears to be the more stable phase. Recovering lithium from the ESC by electrodeposition does not cause the structure to revert to the orthorhombic phase. The orthorhombic and the hexagonal structures of Li2Ti3O7 have similar scavenging capacities for lithium. The report proposes a new mechanism for the phase transformation.

  16. Fatigue of extracted lead zirconate titanate multilayer actuators under unipolar high field electric cycling

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

    Wang, Hong; Lee, Sung Min; Wang, James L.; Lin, Hua-Tay

    2014-12-19

    Testing of large prototype lead zirconate titanate (PZT) stacks presents substantial technical challenges to electronic testing systems, so an alternative approach that uses subunits extracted from prototypes has been pursued. Extracted 10-layer and 20-layer plate specimens were subjected to an electric cycle test under an electric field of 3.0/0.0 kV/mm, 100 Hz to 10^8 cycles. The effects of measurement field level and stack size (number of PZT layers) on the fatigue responses of piezoelectric and dielectric coefficients were observed. On-line monitoring permitted examination of the fatigue response of the PZT stacks. The fatigue rate (based on on-line monitoring) and themore » fatigue index (based on the conductance spectrum from impedance measurement or small signal measurement) were developed to quantify the fatigue status of the PZT stacks. The controlling fatigue mechanism was analyzed against the fatigue observations. The data presented can serve as input to design optimization of PZT stacks and to operation optimization in critical applications such as piezoelectric fuel injectors in heavy-duty diesel engines.« less

  17. Microstructural studies of nanocrystalline barium zirconium titanate (BZT) for piezoelectric applications

    SciTech Connect (OSTI)

    Jamil, Nor Huwaida Janil Izzuddin, Izura; Zainuddin, Zalita; Jumali, Mohammad Hafizuddin Haji

    2015-09-25

    Lead-free piezoelectric ceramics based on barium titanate (BaTiO{sub 3}) with substitution of Zr{sup 4+} were prepared using sol-gel method. The Ba(Zr{sub x}Ti{sub 1-x})O{sub 3}, (BZT) powders with x = 0.0, 0.1, 0.2 and 0.3 were pressed into pellets and sintered at 1250 °C for 2 h. Focusing on the effect of Zr{sup 4+} substitutions into BaTiO{sub 3} perovskite system, the phase transition and microstructural properties of BZT ceramics were studied using XRD, SEM and EDX spectroscopy. All X-ray diffractograms were fitted using Pawley refinement model. The XRD diffractograms revealed the progressive phase transition from tetragonal to cubic phase as Zr content increased. The crystallite exhibited decreasing trend and was supported by shrinkage in grain size. The EDX analysis confirmed the successful substitution of Ti{sup 4+} with Zr{sup 4+} in BaTiO3 crystal.

  18. Growth and micro structural studies on Yittria Stabilized Zirconia (YSZ) and Strontium Titanate (STO) buffer layers

    SciTech Connect (OSTI)

    Srinivas, S.; Bhatnagar, A.K.; Pinto, R.

    1994-12-31

    Microstructure of Yittria Stabilized Zirconia (YSZ) and Strontium Titanate (STO) of radio frequency magnetron sputtered buffer layers was studied at various sputtering conditions on Si<100>, Sapphire and LaAlO{sub 3} <100> substrates. The effect of substrate temperatures upto 800 C and sputtering gas pressures in the range of 50 mTorr. of growth conditions was studied. The buffer layers of YSZ and STO showed a strong tendency for columnar structure with variation growth conditions. The buffer layers of YSZ and STO showed orientation. The tendency for columnar growth was observed above 15 mTorr sputtering gas pressure and at high substrate temperatures. Post annealing of these films in oxygen atmosphere reduced the oxygen deficiency and strain generated during growth of the films. Strong c-axis oriented superconducting YBa{sub 2}Cu{sub 9}O{sub 7-x} (YBCO) thin films were obtained on these buffer layers using pulsed laser ablation technique. YBCO films deposited on multilayers of YSZ and STO were shown to have better superconducting properties.

  19. PHOTODISSOCIATION DYNAMICS OF METHYLAMINE CATION AND ITS RELEVANCE TO TITAN'S IONOSPHERE

    SciTech Connect (OSTI)

    Singh, Prashant Chandra; Shen Lei; Zhou Jia; Schlegel, H. Bernhard; Suits, Arthur G.

    2010-02-10

    Photodissociation of CH{sub 3}NH{sub 2} {sup +} has been studied using the DC sliced ion imaging technique and ab initio calculations in order to understand the formation of HCNH{sup +}, an important molecule in Titan's ionosphere. Our experimental and theoretical observations show that hydrogen loss from CH{sub 3}NH{sub 2} {sup +} has two channels: one giving rise to the triplet species CH{sub 3}NH{sup +}, while the other product is CH{sub 2}NH{sub 2} {sup +}. The latter then decomposes further to form HCNH{sup +}. H{sub 2} loss from CH{sub 3}NH{sub 2} {sup +} has only one channel, yielding CH{sub 2}NH{sup +}. This species further loses H to form HCNH{sup +}. The branching ratio of the H, H{sub 2}, and H+H{sub 2} loss channels is found to be 4.2:1:2.5. This is ascribed to the fact that, at these energies, the H loss has one stable triplet product channel, while most of the H{sub 2} loss product further decomposes to HCNH{sup +}.

  20. Synthesis of Mn-intercalated layered titanate by exfoliation-flocculation approach and its efficient photocatalytic activity under visible-light

    SciTech Connect (OSTI)

    Fu, Jie; Tian, Yanlong; Chang, Binbin; Li, Gengnan; Xi, Fengna; Dong, Xiaoping

    2012-12-15

    A novel Mn-intercalated layered titanate as highly active photocatalyst in visible-light region has been synthesized via a convenient and efficient exfoliation-flocculation approach with divalent Mn ions and monolayer titanate nanosheets. The 0.91 nm interlayer spacing of obtained photocatalyst is in accordance with the sum of the thickness of titanate nanosheet and the diameter of Mn ions. The yellow photocatalyst shows a spectral response in visible-light region and the calculated band gap is 2.59 eV. The photocatalytic performance of this material was evaluated by degradation and mineralization of an aqueous dye methylene blue under visible-light irradiation, and an enhanced photocatalytic activity in comparison with protonated titanate as well as the P25 TiO{sub 2} and N-doped TiO{sub 2} was obtained. Additionally, the layered structure is retained, no dye ions intercalating occurs during the photocatalysis process, and a {approx}90% photocatalytic activity can be remained after reusing 3 cycles. - Graphical abstract: Mn-intercalated layered titanate as a novel and efficient visible-light harvesting photocatalyst was synthesized via a convenient and efficient exfoliation-flocculation approach in a mild condition. Highlights: Black-Right-Pointing-Pointer Mn-intercalated titanate has been prepared by exfoliation-flocculation approach. Black-Right-Pointing-Pointer The as-prepared catalyst shows spectral response in the visible-light region. Black-Right-Pointing-Pointer Heat treatment at certain temperature enables formation of Mn-doped TiO{sub 2}. Black-Right-Pointing-Pointer Dye can be degradated effectively by the catalyst under visible light irradiation.

  1. Structural resistance of chemically modified 1-D nanostructured titanates in inorganic acid environment

    SciTech Connect (OSTI)

    Marinkovic, Bojan A.; Fredholm, Yann C.; Morgado, Edisson

    2010-10-15

    Sodium containing one-dimensional nanostructured layered titanates (1-D NSLT) were produced both from commercial anatase powder and Brazilian natural rutile mineral sands by alkali hydrothermal process. The 1-D NSLT were chemically modified with proton, cobalt or iron via ionic exchange and all products were additionally submitted to intensive inorganic acid aging (pH = 0.5) for 28 days. The morphology and crystal structure transformations of chemically modified 1-D NSLT were followed by transmission electron microscopy, powder X-ray diffraction, selected area electron diffraction and energy dispersive spectroscopy. It was found that the original sodium rich 1-D NSLT and cobalt substituted 1-D NSLT were completely converted to rutile nanoparticles, while the protonated form was transformed in a 70%-30% (by weight) anatase-rutile nanoparticles mixture, very similar to that of the well-known TiO{sub 2}-photocatalyst P25 (Degussa). The iron substituted 1-D NSLT presented better acid resistance as 13% of the original structure and morphology remained, the rest being converted in rutile. A significant amount of remaining 1-D NSLT was also observed after the acid treatment of the product obtained from rutile sand. The results showed that phase transformation of NSLT into titanium dioxide polymorph in inorganic acid conditions were controllable by varying the exchanged cations. Finally, the possibility to transform, through acid aging, 1-D NSLT obtained from Brazilian natural rutile sand into TiO{sub 2}-polymorphs was demonstrated for the first time to the best of authors' knowledge, opening path for producing TiO{sub 2}-nanoproducts with different morphologies through a simple process and from a low cost precursor.

  2. Magnetoelectric coupling of multiferroic chromium doped barium titanate thin film probed by magneto-impedance spectroscopy

    SciTech Connect (OSTI)

    Shah, Jyoti Kotnala, Ravinder K. E-mail: rkkotnala@gmail.com

    2014-04-07

    Thin film of BaTiO{sub 3} doped with 0.1 at. % Cr (Cr:BTO) has been prepared by pulsed laser deposition technique. Film was deposited on Pt/SrTiO{sub 3} substrate at 500 °C in 50 mTorr Oxygen gas pressure using KrF (298 nm) laser. Polycrystalline growth of single phase Cr:BTO thin film has been confirmed by grazing angle X-ray diffraction. Cr:BTO film exhibited remnant polarization 6.4 μC/cm{sup 2} and 0.79 MV/cm coercivity. Magnetization measurement of Cr:BTO film showed magnetic moment 12 emu/cc. Formation of weakly magnetic domains has been captured by magnetic force microscopy. Theoretical impedance equation fitted to experimental data in Cole-Cole plot for thin film in presence of transverse magnetic field resolved the increase in grain capacitance from 4.58 × 10{sup −12} to 5.4 × 10{sup −11} F. Film exhibited high value 137 mV/cm-Oe magneto-electric (ME) coupling coefficient at room temperature. The high value of ME coupling obtained can reduce the typical processing steps involved in multilayer deposition to obtain multiferrocity in thin film. Barium titanate being best ferroelectric material has been tailored to be multiferroic by non ferromagnetic element, Cr, doping in thin film form opens an avenue for more stable and reliable spintronic material for low power magnetoelectric random excess memory applications.

  3. Pyroelectric response of lead zirconate titanate thin films on silicon: Effect of thermal stresses

    SciTech Connect (OSTI)

    Kesim, M. T.; Zhang, J.; Alpay, S. P.; Trolier-McKinstry, S.; Mantese, J. V.; Whatmore, R. W.

    2013-11-28

    Ferroelectric lead zirconate titanate [Pb(Zr{sub x}Ti{sub 1-x}O){sub 3}, (PZT x:1-x)] has received considerable interest for applications related to uncooled infrared devices due to its large pyroelectric figures of merit near room temperature, and the fact that such devices are inherently ac coupled, allowing for simplified image post processing. For ferroelectric films made by industry-standard deposition techniques, stresses develop in the PZT layer upon cooling from the processing/growth temperature due to thermal mismatch between the film and the substrate. In this study, we use a non-linear thermodynamic model to investigate the pyroelectric properties of polycrystalline PZT thin films for five different compositions (PZT 40:60, PZT 30:70, PZT 20:80, PZT 10:90, PZT 0:100) on silicon as a function of processing temperature (25800?C). It is shown that the in-plane thermal stresses in PZT thin films alter the out-of-plane polarization and the ferroelectric phase transformation temperature, with profound effect on the pyroelectric properties. PZT 30:70 is found to have the largest pyroelectric coefficient (0.042??C cm{sup ?2}?C{sup ?1}, comparable to bulk values) at a growth temperature of 550?C; typical to what is currently used for many deposition processes. Our results indicate that it is possible to optimize the pyroelectric response of PZT thin films by adjusting the Ti composition and the processing temperature, thereby, enabling the tailoring of material properties for optimization relative to a specific deposition process.

  4. Transverse piezoelectric coefficient measurement of flexible lead zirconate titanate thin films

    SciTech Connect (OSTI)

    Dufay, T.; Guiffard, B.; Seveno, R.; Thomas, J.-C.

    2015-05-28

    Highly flexible lead zirconate titanate, Pb(Zr,Ti)O{sub 3} (PZT), thin films have been realized by modified sol-gel process. The transverse piezoelectric coefficient d{sub 31} was determined from the tip displacement of bending-mode actuators made of PZT cantilever deposited onto bare or RuO{sub 2} coated aluminium substrate (16 μm thick). The influence of the thickness of ruthenium dioxide RuO{sub 2} and PZT layers was investigated for Pb(Zr{sub 0.57}Ti{sub 0.43})O{sub 3}. The modification of Zr/Ti ratio from 40/60 to 60/40 was done for 3 μm thick PZT thin films onto aluminium (Al) and Al/RuO{sub 2} substrates. A laser vibrometer was used to measure the beam displacement under controlled electric field. The experimental results were fitted in order to find the piezoelectric coefficient. Very large tip deflections of about 1 mm under low voltage (∼8 V) were measured for every cantilevers at the resonance frequency (∼180 Hz). For a given Zr/Ti ratio of 58/42, it was found that the addition of a 40 nm thick RuO{sub 2} interfacial layer between the aluminium substrate and the PZT layer induces a remarkable increase of the d{sub 31} coefficient by a factor of 2.7, thus corresponding to a maximal d{sub 31} value of 33 pC/N. These results make the recently developed PZT/Al thin films very attractive for both low frequency bending mode actuating applications and vibrating energy harvesting.

  5. Atomic layer deposition of epitaxial layers of anatase on strontium titanate single crystals: Morphological and photoelectrochemical characterization

    SciTech Connect (OSTI)

    Kraus, Theodore J.; Nepomnyashchii, Alexander B.; Parkinson, B. A.

    2015-01-15

    Atomic layer deposition was used to grow epitaxial layers of anatase (001) TiO{sub 2} on the surface of SrTiO{sub 3} (100) crystals with a 3% lattice mismatch. The epilayers grow as anatase (001) as confirmed by x-ray diffraction. Atomic force microscope images of deposited films showed epitaxial layer-by-layer growth up to about 10 nm, whereas thicker films, of up to 32 nm, revealed the formation of 2–5 nm anatase nanocrystallites oriented in the (001) direction. The anatase epilayers were used as substrates for dye sensitization. The as received strontium titanate crystal was not sensitized with a ruthenium-based dye (N3) or a thiacyanine dye (G15); however, photocurrent from excited state electron injection from these dyes was observed when adsorbed on the anatase epilayers. These results show that highly ordered anatase surfaces can be grown on an easily obtained substrate crystal.

  6. Tuned sensitivity towards H{sub 2}S and NH{sub 3} with Cu doped barium strontium titanate materials

    SciTech Connect (OSTI)

    Simion, C. E. Teodorescu, V. S.; Stănoiu, A.; Sackmann, A.; Ruşti, C. F.; Piticescu, R. M.

    2014-11-05

    The different amount of Cu-doped Barium Strontium Titanate (BST) thick film materials have been tested for their gas-sensing performances towards NH{sub 3} and H{sub 2}S under dry and 50% relative humidity (RH) background conditions. The optimum NH{sub 3} sensitivity was attained with 0.1mol% Cu-doped BST whereas the selective detection of H{sub 2}S was highlighted using 5mol% Cu-doped BST material. No cross-sensitivity effects to CO, NO{sub 2}, CH{sub 4} and SO{sub 2} were observed for all tested materials operated at their optimum temperature (200°C) under humid conditions (50% RH). The presence of humidity clearly enhances the gas sensitivity to NH{sub 3} and H{sub 2}S detection.

  7. RHEOLOGY OF SETTLED SOLIDS IN THE SMALL COLUMN ION EXCHANGE PROCESS

    SciTech Connect (OSTI)

    Ferguson, C.; Prior, M.; Koopman, D.; Edwards, T.

    2011-06-20

    The Small Column Ion Exchange (SCIX) process is being developed to remove cesium, strontium, and actinides from Savannah River Site (SRS) Liquid Waste using an existing waste tank as process housing. This method includes the addition of monosodium titanate (MST) to a waste tank containing salt solution and entrained sludge solids, followed by tank mixing and filtration. The filtrate is then processed through in-tank ion exchange columns containing crystalline silicotitanate (CST) media. While the process is operating, it is known that solid particles begin to settle in the tank and temperatures may reach beyond 45 C. Previous testing has shown that sludge-MST slurries that sit for extended periods at elevated temperatures can develop large shear strengths, making them difficult to resuspend and remove from the tank. The authors conducted rheological testing of mixtures containing various concentrations of sludge simulant, MST, and CST (three preparations) that were aged at different times (i.e., 0 to 13 weeks) and isothermally maintained to 30, 45, or 60 C. Two types of grinding methodologies were employed to prepare CST for this testing, herein called Savannah River National Laboratory (SRNL) and Vitreous State Laboratory (VSL) ground materials. Unground CST particles were also tested. A small number of samples were irradiated prior to 4 week settling and 60 C temperature treatment, with exposures ranging from 0 to 100 MRad. Additional tests are also being conducted that will allow the solid particles to settle at 45 C for 6, 12, and 24 months. The objectives of this task are to determine the impact of feed composition, settling time, and temperature on the shear strength, yield stress, and consistency of the slurries and to determine the impact of radiation on slurry rheology. The testing will determine the relative impact of these parameters rather than predict the shear strength, yield stress, and consistency as a function of feed and operating conditions. This

  8. Real-time radiography of Titan IV Solid Rocket Motor Upgrade (SRMU) static firing test QM-2

    SciTech Connect (OSTI)

    Dolan, K.W.; Curnow, G.M.; Perkins, D.E.; Schneberk, D.J.; Costerus, B.W.; La Chapell, M.J.; Turner, D.E.; Wallace, P.W.

    1994-03-08

    Real-time radiography was successfully applied to the Titan-IV Solid Rocket Motor Upgrade (SRMU) static firing test QM-2 conducted February 22, 1993 at Phillips Laboratory, Edwards AFB, CA. The real-time video data obtained in this test gave the first incontrovertible evidence that the molten slag pool is low (less than 5 to 6 inches in depth referenced to the bottom of the aft dome cavity) before T + 55 seconds, builds fairly linearly from this point in time reaching a quasi-equilibrium depth of 16 to 17 inches at about T + 97 seconds, which is well below the top of the vectored nozzle, and maintains that level until T + 125 near the end motor burn. From T + 125 seconds to motor burn-out at T + 140 seconds the slag pool builds to a maximum depth of about 20 to 21 inches, still well below the top of the nozzle. The molten slag pool was observed to interact with motions of the vectored nozzle, and exhibit slosh and wave mode oscillations. A few slag ejection events were also observed.

  9. Symmetries and multiferroic properties of novel room-temperature magnetoelectrics: Lead iron tantalate – lead zirconate titanate (PFT/PZT)

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

    Sanchez, Dilsom A.; Ortega, N.; Kumar, Ashok; Roque-Malherbe, R.; Polanco, R.; Scott, J. F.; Katiyar, Ram S.

    2011-12-01

    Mixing 60-70% lead zirconate titanate with 40-30% lead iron tantalate produces a single-phase, low-loss, room-temperature multiferroic with magnetoelectric coupling: (PbZr₀.₅₃Ti₀.₄₇O₃) (1-x)- (PbFe₀.₅Ta₀.₅O₃)x. The present study combines x-ray scattering, magnetic and polarization hysteresis in both phases, plus a second-order dielectric divergence (to epsilon = 6000 at 475 K for 0.4 PFT; to 4000 at 520 K for 0.3 PFT) for an unambiguous assignment as a C2v-C4v (Pmm2-P4mm) transition. The material exhibits square saturated magnetic hysteresis loops with 0.1 emu/g at 295 K and saturation polarization Pr = 25 μC/cm², which actually increases (to 40 μC/cm²) in the high-T tetragonal phase, representingmore » an exciting new room temperature oxide multiferroic to compete with BiFeO₃. Additional transitions at high temperatures (cubic at T>1300 K) and low temperatures (rhombohedral or monoclinic at T<250 K) are found. These are the lowest-loss room-temperature multiferroics known, which is a great advantage for magnetoelectric devices.« less

  10. IMPACT OF SMALL COLUMN ION EXCHANGE STREAMS ON DWPF GLASS FORMULATION MELT RATE STUDIES

    SciTech Connect (OSTI)

    Fox, K.; Miller, D.; Koopman, D.

    2011-04-26

    This study was undertaken to evaluate the potential impacts of the Small Column Ion Exchange (SCIX) streams - particularly the addition of Monosodium Titanate (MST) and Crystalline Silicotitanate (CST) - on the melt rate of simulated feed for the Defense Waste Processing Facility (DWPF). Additional MST was added to account for contributions from the Salt Waste Processing Facility (SWPF). The Savannah River National Laboratory (SRNL) Melt Rate Furnace (MRF) was used to evaluate four melter feed compositions: two with simulated SCIX and SWPF material and two without. The Slurry-fed Melt Rate Furnace (SMRF) was then used to compare two different feeds: one with and one without bounding concentrations of simulated SCIX and SWPF material. Analyses of the melter feed materials confirmed that they met their targeted compositions. Four feeds were tested in triplicate in the MRF. The linear melt rates were determined by using X-ray computed tomography to measure the height of the glass formed along the bottom of the beakers. The addition of the SCIX and SWPF material reduced the average measured melt rate by about 10% in MRF testing, although there was significant scatter in the data. Two feeds were tested in the SMRF. It was noted that the ground CST alone (ground CST with liquid in a bucket) was extremely difficult to resuspend during preparation of the feed with material from SCIX and SWPF. This feed was also more difficult to pump than the material without MST and CST due to settling occurring in the melter feed line, although the yield stress of both feeds was high relative to the DWPF design basis. Steady state feeding conditions were maintained for about five hours for each feed. There was a reduction in the feed and pour rates of approximately 15% when CST and MST were added to the feed, although there was significant scatter in the data. Analysis of samples collected from the SMRF pour stream showed that the composition of the glass changed as expected when MST and

  11. Rotary Microfilter Media Evaluation

    SciTech Connect (OSTI)

    Poirier, M

    2005-04-20

    Savannah River National Laboratory (SRNL) received funding from DOE EM-21, Office of Cleanup Technologies, to develop the rotary microfilter for high level radioactive service. One aspect of this project evaluated alternative filter media to select one for the 2nd generation rotary microfilter being procured as a prefilter to a small column ion exchange process. The authors conducted screening tests on a variety of filter media and pore sizes using a stirred cell followed by pilot-scale testing on a more limited number of filter media and pore sizes with a three disk rotary microfilter. These tests used 5.6 molar sodium supernate, and sludge plus monosodium titanate (MST) solids. The conclusions from this work are: (1) The 0.1 {micro} nominal TruMem{reg_sign} ceramic and the Pall PMM M050 (0.5 {micro} nominal) stainless steel filter media produced the highest flux in rotary filter testing. (2) The Pall PMM M050 media produced the highest flux of the stainless steel media tested in rotary filter testing. (3) The Pall PMM M050 media met filtrate quality requirements for the rotary filter. (4) The 0.1 {micro} TruMem{reg_sign} and 0.1 {micro} Pall PMM media met filtrate quality requirements as well. (5) The Pall PMM M050 media produced comparable flux to the 0.1 {micro} TruMem{reg_sign} media, and proved more durable and easier to weld. Based on these test results, the authors recommend Pall PMM M050 filter media for the 2nd generation rotary microfilter.

  12. Structural, microstructural and thermal properties of lead-free bismuthsodiumbariumtitanate piezoceramics synthesized by mechanical alloying

    SciTech Connect (OSTI)

    Amini, Rasool; Ghazanfari, Mohammad Reza; Alizadeh, Morteza; Ardakani, Hamed Ahmadi; Ghaffari, Mohammad

    2013-02-15

    Graphical abstract: Mechano-synthesis of lead-free (Bi{sub 0.5}Na{sub 0.5}){sub 0.94}Ba{sub 0.06}TiO{sub 3} piezoceramics with nanocrystalline/amorphous structure and homogeneous composition: partial transformation of constituents to BNBT, BNT and pyrochlore, amorphous phase formation, mechano-crystallization of the amorphous, pyrochlore-to-perovskite BNBT phase transformation during the process. Display Omitted Highlights: ? Perovskite BNBT powders with homogeneous composition were synthesized by MA. ? Partial transformation of constituents to BNBT, BNT and pyrochlore occurred by MA. ? Formation of an amorphous phase and afterwards its crystallization occurred by MA. ? Pyrochlore-to-perovskite BNBT phase transformation occurred after prolong milling. ? Polymorphic transformations of TiO{sub 2} act as the main alloying impediment during MA. -- Abstract: Bismuthsodiumbariumtitanate piezoceramics with a composition of (Bi{sub 0.5}Na{sub 0.5}){sub 0.94}Ba{sub 0.06}TiO{sub 3} (BNBT) were prepared by mechanical alloying (MA). Structural analysis and phase identification were performed by X-ray diffraction (XRD). Microstructural studies and chemical composition homogeneity were performed by scanning electron microscope (SEM) coupled with energy dispersive X-ray analysis (EDX). Furthermore, thermal properties of the as-milled powders were evaluated by thermogravimetry/differential thermal analysis (TG/DTA). During the initial milling, the constituents were transformed to the perovskite, pyrochlore, and BNT phases; in addition, partial amorphization of the structure appeared during the milling cycle. As MA progressed, transformation of pyrochlore-to-perovskite and crystallization of the amorphous phase occurred and also, the BNBT phase was significantly developed. It was found that the MA process has the ability to synthesize the BNBT powders with a submicron particle size, regular morphology, and uniform elemental distribution.

  13. FABRICATION AND TESTING OF MICROWAVE SINTERED SOL-GEL SPRAY-ON BISMUTH TITANATE-LITHIUM NIOBATE BASED PIEZOELECTRIC COMPOSITE FOR USE AS A HIGH TEMPERATURE (>500 deg. C) ULTRASONIC TRANSDUCER

    SciTech Connect (OSTI)

    Searfass, C. T.; Baba, A.; Tittmann, B. R.; Agrawal, D. K.

    2010-02-22

    Bismuth titanate-lithium niobate based ultrasonic transducers have been fabricated using a sol-gel spray-on deposition technique. These transducers were then tested to determine their potential as high temperature ultrasonic transducers. Fabricated transducers were capable of operating to 1000 deg. C in pulse-echo mode; however, the exposure to such extreme temperatures appears to be destructive to the transducers.

  14. THE IMPLANTATION AND INTERACTIONS OF O{sup +} IN TITAN'S ATMOSPHERE: LABORATORY MEASUREMENTS OF COLLISION-INDUCED DISSOCIATION OF N{sub 2} AND MODELING OF POSITIVE ION FORMATION

    SciTech Connect (OSTI)

    Shah, M. B.; Latimer, C. J.; Montenegro, E. C.; Tucker, O. J.; Johnson, R. E.; Smith, H. T.

    2009-10-01

    Energetic oxygen ions are an important component of the plasma incident onto Titan's atmosphere. Therefore, we report measurements of electron capture and ionization collisions of N{sub 2} with incident O{sup +} over the energy range 10-100 keV. Using time of flight coincidence counting techniques we also measured the collision-induced dissociation of N{sub 2} following ionization and electron capture. The electron capture and ionization cross sections were found to have comparable magnitudes. Capture collisions are dominated by non-dissociative processes with the dissociative processes providing contributions that are only slightly smaller. In contrast, ionization is entirely dominated by the dissociative processes. The energy distributions of the N{sup +} and N atom fragments ejected by 20, 50, and 100 keV incident O{sup +} projectiles have also been determined. These fragments carry considerable amounts of energy and if produce in the exobase region can readily escape. The cross sections measured here have been used with Cassini energetic ion and atmospheric density data to determine the ionization by and neutralization of energetic O{sup +} penetrating Titan's N{sub 2} rich atmosphere. Neutralization by charge exchange is found not to occur efficiently above Titan's exobase, so energetic particles with large gyroradii penetrate the atmosphere primarily as ions. When the energetic O{sup +} flux is large, we also show it is an important source of ionization and heating at depth into Titan's atmosphere and the fragments contribute to the net atmospheric loss rate.

  15. DWPF Flowsheet Studies with Simulants to Determine Modular Caustic Side Solvent Extraction Unit Solvent Partitioning and Verify Actinide Removal Process Incorporation Strategy

    SciTech Connect (OSTI)

    Herman, C

    2006-04-21

    The Actinide Removal Process (ARP) facility and the Modular Caustic Side Solvent Extraction Unit (MCU) are scheduled to begin processing salt waste in fiscal year 2007. A portion of the streams generated in the salt processing facilities will be transferred to the Defense Waste Processing Facility (DWPF) to be incorporated in the glass matrix. Before the streams are introduced, a combination of impact analyses and research and development studies must be performed to quantify the impacts on DWPF processing. The Process Science & Engineering (PS&E) section of the Savannah River National Laboratory (SRNL) was requested via Technical Task Request (TTR) HLW/DWPF/TTR-2004-0031 to evaluate the impacts on DWPF processing. Simulant Chemical Process Cell (CPC) flowsheet studies have been performed using previous composition and projected volume estimates for the ARP sludge/monosodium titanate (MST) stream. Due to changes in the flammability control strategy for DWPF for salt processing, the incorporation strategy for ARP has changed and additional ARP flowsheet tests were necessary to validate the new processing strategy. The last round of ARP testing included the incorporation of the MCU stream and identified potential processing issues with the MCU solvent. The identified issues included the potential carry-over and accumulation of the MCU solvent components in the CPC condensers and in the recycle stream to the Tank Farm. Therefore, DWPF requested SRNL to perform additional MCU flowsheet studies to better quantify the organic distribution in the CPC vessels. The previous MCU testing used a Sludge Batch 4 (SB4) simulant since it was anticipated that both of these facilities would begin salt processing during SB4 processing. The same sludge simulant recipe was used in this round of ARP and MCU testing to minimize the number of changes between the two phases of testing so a better comparison could be made. ARP and MCU stream simulants were made for this phase of testing

  16. ROTARY FILTER FINES TESTING FOR SMALL COLUMN ION EXCHANGE

    SciTech Connect (OSTI)

    Herman, D.

    2011-08-03

    SRNL was requested to quantify the amount of 'fines passage' through the 0.5 micron membranes currently used for the rotary microfilter (RMF). Testing was also completed to determine if there is any additional benefit to utilizing a 0.1 micron filter to reduce the amount of fines that could pass through the filter. Quantifying of the amount of fines that passed through the two sets of membranes that were tested was accomplished by analyzing the filtrate by Inductively Coupled Plasma Atomic Emission Spectrometry (ICP-AES) for titanium. Even with preparations to isolate the titanium, all samples returned results of less than the instrument's detection limit of 0.184 mg/L. Test results show that the 0.5 micron filters produced a significantly higher flux while showing a negligible difference in filtrate clarity measured by turbidity. The first targeted deployment of the RMF is with the Small Column Ion Exchange (SCIX) at the Savannah River Site (SRS). SCIX uses crystalline silicotitanate (CST) to sorb cesium to decontaminate a clarified salt solution. The passage of fine particles through the filter membranes in sufficient quantities has the potential to impact the downstream facilities. To determine the amount of fines passage, a contract was established with SpinTek Filtration to operate a 3-disk pilot scale unit with prototypic filter disk and various feeds and two different filter disk membranes. SpinTek evaluated a set of the baseline 0.5 micron filter disks as well as a set of 0.1 micron filter disks to determine the amount of fine particles that would pass the membrane and to determine the flux each set produced. The membrane on both disk sets is manufactured by the Pall Corporation (PMM 050). Each set of disks was run with three feed combinations: prototypically ground CST, CST plus monosodium titanate (MST), and CST, MST, plus Sludge Batch 6 (SB6) simulant. Throughout the testing, samples of the filtrate were collected, measured for turbidity, and sent back

  17. Development of Chemical Treatment Alternatives for Tetraphenylborate Destruction in Tank 48H

    SciTech Connect (OSTI)

    LAMBERT, DANIELP.

    2004-05-04

    This study assessed chemical treatment options for decomposing the tetraphenylborate in High Level Waste (HLW) Tank 48H. Tank 48H, located at the Savannah River Site in Aiken, SC, contains approximately one million liters of HLW. The tetraphenylborate slurry represents legacy material from commissioning of an In Tank Precipitation process to separate radioactive cesium and actinides from the non radioactive chemicals. During early operations, the process encountered an unplanned chemical reaction that catalytically decomposed the excess tetraphenylborate producing benzene. Subsequent research indicated that personnel could not control the operations within the existing equipment to both meet the desired treatment rate for the waste and maintain the benzene concentration within allowable concentrations. Since then, the Department of Energy selected an alternate treatment process for handling high-level waste at the site. However, the site must destroy the tetraphenylborate before returning the tank to HLW service. The research focuses on identifying treatments to decompose tetraphenylborate to the maximum extent feasible, with a preference for decomposition methods that produce carbon dioxide rather than benzene. A number of experiments examined whether the use of oxidants, catalysts or acids proved effective in decomposing the tetraphenylborate. Additional experiments developed an understanding of the solid, liquid and gas decomposition products. The testing identified several successful treatment options including: an iron catalyst combined with hydrogen peroxide (Fenton's reagent) with added acid; sodium permanganate with added acid; and copper catalyst with added acid. A mistake occurred in the selection and make-up of the Tank 48H simulant recipe which led to an under representation of the amount of monosodium titanate and insoluble sludge solids compared to the simulant target. The amount of added MST and sludge proved about a factor of 40 low relative to the

  18. 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

  19. Enhanced durability for high-temperature desulfurization sorbents for moving-bed applications -- Option 3 program: Development and testing of additional zinc titanate sorbents. Final report, September 1992--May 1996

    SciTech Connect (OSTI)

    Ayala, R.E.; Chuck, T.L.

    1996-12-31

    GE is developing a moving-bed, high-temperature desulfurization system for the integrated gasification combined-cycle (IGCC) power cycle in which zinc-based regenerable sorbents are currently being used as desulfurization sorbents. Zinc titanate and other zinc-based oxides are being considered as sorbents for use in the Clean Coal Technology Demonstration Program at Tampa Electric Co.`s Polk Power Station. A key to success in the development of high-temperature desulfurization systems is the matching of sorbent properties for the selected process operating conditions, namely, sustainable desulfurization kinetics, high sulfur capacity, and mechanical durability over multiple cycles. Additionally, the sulfur species produced during regeneration of the sorbent must be in a form compatible with sulfur recovery systems, such as sulfuric acid or elemental sulfur processes. The objective of this contract is to identify and test sorbent fabrication methods and chemical compositions that enhance the long-term chemical reactivity and mechanical strength of zinc titanate and other novel sorbents for moving-bed, high-temperature desulfurization of coal-derived gases. A parametric study on the use of calcium sulfate additives to zinc titanate was conducted for zinc titanates having a 2:1 and 1.5:1 zinc-to-titanium molar ratio, and they showed a beneficial effect on crush strength of fresh 2:1 zinc titanate sorbents. In addition, a test procedure was developed to screen sorbent formulations based on resistance to spalling and pellet breakage induced by zinc sulfate formation in the presence of sulfur dioxide and excess oxygen conditions.

  20. THE {nu}{sub 8} BENDING MODE OF DIACETYLENE: FROM LABORATORY SPECTROSCOPY TO THE DETECTION OF {sup 13}C ISOTOPOLOGUES IN TITAN'S ATMOSPHERE

    SciTech Connect (OSTI)

    Jolly, A.; Benilan, Y.; Fayt, A.; Jacquemart, D.; Nixon, C. A.; Jennings, D. E.

    2010-05-01

    The strong {nu}{sub 8} band of diacetylene at 627.9 cm{sup -1} has been investigated to improve the spectroscopic line data used to model the observations, particularly in Titan's atmosphere by Cassini/Composite Infrared Spectrometer. Spectra have first been recorded in the laboratory at 0.5 and 0.1 cm{sup -1} resolution and temperature as low as 193 K. Previous analysis and line lists present in the GEISA database appeared to be insufficient to model the measured spectra in terms of intensity and hot band features. To improve the situation and in order to be able to take into account all rovibrational transitions with a non-negligible intensity, a global analysis of C{sub 4}H{sub 2} has been carried out to improve the description of the energy levels up to E{sub v} = 1900 cm{sup -1}. The result is a new extensive line list which enables us to model very precisely the temperature variation as well as the numerous hot band features observed in the laboratory spectra. One additional feature, observed at 622.3 cm{sup -1}, was assigned to the {nu}{sub 6} mode of a {sup 13}C isotopologue of diacetylene. The {nu}{sub 8} bands of both {sup 13}C isotopomers were also identified in the 0.1 cm{sup -1} resolution spectrum. Finally, a {sup 13}C/C{sub 4}H{sub 2} line list was added to the model for comparison with the observed spectra of Titan. We obtain a clear detection of {sup 13}C monosubstituted diacetylene at 622.3 cm{sup -1} and 627.5 cm{sup -1} (blended {nu}{sub 8} bands), deriving a mean {sup 12}C/{sup 13}C isotopic ratio of 90 {+-} 8. This value agrees with the terrestrial (89.4, inorganic standard) and giant planet values (88 {+-} 7), but is only marginally consistent with the bulk carbon value in Titan's atmosphere, measured in CH{sub 4} by Huygens GCMS to be 82 {+-} 1, indicating that isotopic fractionation during chemical processing may be occurring, as suggested for ethane formation.

  1. 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

  2. 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.

  3. 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.

  4. Electric field and temperature dependence of dielectric permittivity in strontium titanate investigated by a photoemission study on Pt/SrTiO{sub 3}:Nb junctions

    SciTech Connect (OSTI)

    Hirose, Sakyo; Okushi, Hideyo; Yoshikawa, Hideki; Adachi, Yutaka; Ohsawa, Takeo; Haneda, Hajime; Ueda, Shigenori; Ando, Akira; Ohashi, Naoki

    2015-05-11

    Schottky junctions made from platinum and niobium-doped strontium titanate (SrTiO{sub 3}:Nb) were investigated by hard X-ray photoemission (HXPES) and through a band bending behavior simulation using a phenomenological model, which assumes a decrease in dielectric constant due to an electric field. Thus, we confirmed that the observed HXPES spectra at relatively high temperatures, e.g., >250?K, were well simulated using this phenomenological model. In contrast, it was inferred that the model was not appropriate for junction behavior at lower temperatures, e.g., <150?K. Therefore, a reconstruction of the phenomenological model is necessary to adequately explain the dielectric properties of SrTiO{sub 3}.

  5. Low leakage Ru-strontium titanate-Ru metal-insulator-metal capacitors for sub-20 nm technology node in dynamic random access memory

    SciTech Connect (OSTI)

    Popovici, M. Swerts, J.; Redolfi, A.; Kaczer, B.; Aoulaiche, M.; Radu, I.; Clima, S.; Everaert, J.-L.; Van Elshocht, S.; Jurczak, M.

    2014-02-24

    Improved metal-insulator-metal capacitor (MIMCAP) stacks with strontium titanate (STO) as dielectric sandwiched between Ru as top and bottom electrode are shown. The Ru/STO/Ru stack demonstrates clearly its potential to reach sub-20 nm technology nodes for dynamic random access memory. Downscaling of the equivalent oxide thickness, leakage current density (J{sub g}) of the MIMCAPs, and physical thickness of the STO have been realized by control of the Sr/Ti ratio and grain size using a heterogeneous TiO{sub 2}/STO based nanolaminate stack deposition and a two-step crystallization anneal. Replacement of TiN with Ru as both top and bottom electrodes reduces the amount of electrically active defects and is essential to achieve a low leakage current in the MIM capacitor.

  6. CHARACTERIZATION REPORT FOR STRONTIUM TITANATE IN SWSA 7 AND ADJACENT PARCELS IN SUPPORT OF THE NATIONAL PRIORITIES LIST SITE BOUNDARY DEFINITION PROGRAM OAK RIDGE, TENNESSEE

    SciTech Connect (OSTI)

    David A. King

    2011-10-10

    The U.S. Department of Energy (DOE) Oak Ridge Office requested support from the Oak Ridge Institute for Science and Education (ORISE) contract to delineate the extent of strontium titanate (SrTiO3) contamination in and around Solid Waste Storage Area (SWSA) 7 as part of the Oak Ridge National Priorities List Site boundary definition program. The study area is presented in Fig. 1.1 relative to the Oak Ridge Reservation (ORR). The investigation was executed according to Sampling and Analysis Plan/Quality Assurance Project Plan (SAP/QAPP) (DOE 2011) to supplement previous investigations noted below and to determine what areas, if any, have been adversely impacted by site operations.

  7. 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

  8. DEMONSTRATION OF THE DWPF FLOWSHEET IN THE SRNL SHIELDED CELLS USING ARP PRODUCT SIMULANT AND SB4 TANK 40 SLUDGE SLURRY

    SciTech Connect (OSTI)

    Lambert, D; John Pareizs, J; Bradley Pickenheim, B; Cj Bannochie, C; Michael Stone, M; Damon Click, D; Erich Hansen, E; Kim Crapse, K; David Hobbs, D

    2008-05-14

    The radioactive startup of two new SRS processing facilities, the Actinide Removal Process (ARP) and the Modular Caustic-Side-Solvent-Extraction Unit (MCU) will add two new waste streams to the Defense Waste Processing Facility (DWPF). The ARP will remove actinides from the 5.6 M salt solution resulting in a sludge-like product that is roughly half monosodium titanate (MST) insoluble solids and half sludge insoluble solids. The ARP product will be added to the Sludge Receipt and Adjustment Tank (SRAT) at boiling and dewatered prior to pulling a SRAT receipt sample. The cesium rich MCU stream will be added to the SRAT at boiling after both formic and nitric acid have been added and the SRAT contents concentrated to the appropriate endpoint. A concern was raised by an external hydrogen review panel that the actinide loaded MST could act as a catalyst for hydrogen generation (Mar 15, 2007 report, Recommendation 9). Hydrogen generation, and it's potential to form a flammable mixture in the off-gas, under SRAT and Slurry Mix Evaporator (SME) processing conditions has been a concern since the discovery that noble metals catalyze the decomposition of formic acid. Radiolysis of water also generates hydrogen, but the radiolysis rate is orders of magnitude lower than the noble metal catalyzed generation. As a result of the concern raised by the external hydrogen review panel, hydrogen generation was a prime consideration in this experiment. Testing was designed to determine whether the presence of the irradiated ARP simulant containing MST caused uncontrolled or unexpected hydrogen production during experiments simulating the DWPF Chemical Process Cell (CPC) due to activation of titanium. A Shielded Cells experiment, SC-5, was completed using SB4 sludge from Tank 405 combined with an ARP product produced from simulants by SRNL researchers. The blend of sludge and MST was designed to be prototypic of planned DWPF SRAT and SME cycles. As glass quality was not an objective in

  9. Nanostructured aluminium titanate (Al{sub 2}TiO{sub 5}) particles and nanofibers: Synthesis and mechanism of microstructural evolution

    SciTech Connect (OSTI)

    Azarniya, Abolfazl; Azarniya, Amir; Hosseini, Hamid Reza Madaah; Simchi, Abdolreza

    2015-05-15

    In this study, aluminium titanate (AT) particles and nanofibers were synthesized through citrate sol gel and sol gel-assisted electrospinning methods in both nanostructured powder and nanofiber forms. The results of X-ray diffraction analysis, field-emission scanning electron microscopy and differential thermal analysis showed that the synthetic products benefit a nanostructured nature with a grain size less than 70 nm. The optimal values for time and temperature at which a roughly pure AT is attained were determined as 2 h and 900 °C, respectively. It was found that the sol gel precursor bears an amorphous structure till 700 °C and begins to be crystallized to alumina, anatase and AT at higher temperatures. Moreover, AT tends to decompose into rutile and alumina at temperatures higher than 900 °C and its degradation rate reaches a maximum at temperatures near to 1100 °C. In this synthesis, citric acid was used as a chelating agent for Al{sup 3} {sup +} and Ti{sup 4} {sup +} ions and it was shown that a low citric acid-to-metal cation ratio leads to larger numbers of nuclei during crystallization and smaller grain size. Finally, a model was suggested to describe the microstructural evolution of AT compound based on a nucleation and growth regime. - Graphical abstract: Display Omitted - Highlights: • We synthesized aluminium titanate ceramic in both powder and nanofiber forms. • The methods in use were citrate sol gel and sol gel-assisted electrospinning. • Powders and nanofibers bear a nanostructured nature with a grain size less than 70 nm. • A model is suggested to describe microstructural evolution of synthetic products.

  10. Synthesis and crystal chemistry of microporous titanates K{sub x}(Ti,M){sub 8}O{sub 16} where M=Sc–Ni

    SciTech Connect (OSTI)

    Moetakef, Pouya; Larson, Amber M.; Hodges, Brenna C.; Zavalij, Peter; Gaskell, Karen J.; Piccoli, Philip M.; Rodriguez, Efrain E.

    2014-12-15

    Through salt-flux methods, single crystals of eight novel hollandite-type titanates have been grown with the stoichiometry K{sub x}(Ti{sub 8−y}M{sub y}){sub 8}O{sub 16} for x=y≈1.5 where M{sup 3+}=Sc, Ti, V, Cr, Mn, and Fe, and for x/2=y≈0.75 where M{sup 2+}=Co and Ni. Single crystal and powder X-ray diffraction reveals phase pure crystals with tetragonal space group I4/m. These titanates are microporous oxides with 1-dimensional channels where the non-framework cation, K, resides. In addition to diffraction, spectroscopic methods were used to characterize the chemical composition of both the bulk and surface. X-ray photoelectron spectroscopy affords the oxidation states of the substituted transition metals M on the surface and energy dispersive X-ray spectroscopy the metal ratios, including that of potassium, for an overall accurate description of the chemical composition of both the bulk and surface. Magnetization versus temperature measurements indicate that all phases are Curie paramagnets with effective magnetic moments consistent with the d-electron count given by combined X-ray diffraction and elemental analysis techniques. - Highlights: • Single crystal growth of K{sub x}(Ti,M){sub 8}O{sub 16} for M=Sc–Ni via molten salt flux. • Single crystal and powder X-ray diffraction utilized for structure of all compounds. • Oxidation states for all metals determined by X-ray photoelectron spectroscopy. • Cation stoichiometry confirmed by energy dispersive spectroscopy. • Effective moments from magnetization coincide with spectroscopy results.

  11. Physics and technology in the ion-cyclotron range of frequency on Tore Supra and TITAN test facility: implication for ITER

    SciTech Connect (OSTI)

    Litaudon, X; Bernard, J. M.; Colas, L.; Dumont, R. J.; Argouarch, A.; Bottollier-Curtet, H.; Bremond, S.; Champeaux, S.; Corre, Y.; Dumortier, P.; Firdaouss, M.; Guilhem, D.; Gunn, J. P.; Gouard, Ph.; Hoang, G T; Jacquot, Jonathan; Klepper, C Christopher; Kubic, M.; Kyrytsya, V.; Lombard, G.; Milanesio, D.; Messiaen, A.; Mollard, P.; Meyer, O.; Zarzoso, D.

    2013-01-01

    To support the design of an ITER ion-cyclotron range of frequency heating (ICRH) system and to mitigate risks of operation in ITER, CEA has initiated an ambitious Research & Development program accompanied by experiments on Tore Supra or test-bed facility together with a significant modelling effort. The paper summarizes the recent results in the following areas: Comprehensive characterization (experiments and modelling) of a new Faraday screen concept tested on the Tore Supra antenna. A new model is developed for calculating the ICRH sheath rectification at the antenna vicinity. The model is applied to calculate the local heat flux on Tore Supra and ITER ICRH antennas. Full-wave modelling of ITER ICRH heating and current drive scenarios with the EVE code. With 20 MW of power, a current of 400 kA could be driven on axis in the DT scenario. Comparison between DT and DT(3He) scenario is given for heating and current drive efficiencies. First operation of CW test-bed facility, TITAN, designed for ITER ICRH components testing and could host up to a quarter of an ITER antenna. R&D of high permittivity materials to improve load of test facilities to better simulate ITER plasma antenna loading conditions.

  12. OPERATIONS REVIEW OF THE SAVANNAH RIVER SITE INTEGRATED SALT DISPOSITION PROCESS - 11327

    SciTech Connect (OSTI)

    Peters, T.; Poirier, M.; Fondeur, F.; Fink, S.; Brown, S.; Geeting, M.

    2011-02-07

    The Savannah River Site (SRS) is removing liquid radioactive waste from its Tank Farm. To treat waste streams that are low in Cs-137, Sr-90, and actinides, SRS developed the Actinide Removal Process and implemented the Modular Caustic Side Solvent Extraction (CSSX) Unit (MCU). The Actinide Removal Process contacts salt solution with monosodium titanate to sorb strontium and select actinides. After monosodium titanate contact, the resulting slurry is filtered to remove the monosodium titanate (and sorbed strontium and actinides) and entrained sludge. The filtrate is transferred to the MCU for further treatment to remove cesium. The solid particulates removed by the filter are concentrated to {approx} 5 wt %, washed to reduce the sodium concentration, and transferred to the Defense Waste Processing Facility for vitrification. The CSSX process extracts the cesium from the radioactive waste using a customized solvent to produce a Decontaminated Salt Solution (DSS), and strips and concentrates the cesium from the solvent with dilute nitric acid. The DSS is incorporated in grout while the strip acid solution is transferred to the Defense Waste Processing Facility for vitrification. The facilities began radiological processing in April 2008 and started processing of the third campaign ('MarcoBatch 3') of waste in June 2010. Campaigns to date have processed {approx}1.2 million gallons of dissolved saltcake. Savannah River National Laboratory (SRNL) personnel performed tests using actual radioactive samples for each waste batch prior to processing. Testing included monosodium titanate sorption of strontium and actinides followed by CSSX batch contact tests to verify expected cesium mass transfer. This paper describes the tests conducted and compares results from facility operations. The results include strontium, plutonium, and cesium removal, cesium concentration, and organic entrainment and recovery data. Additionally, the poster describes lessons learned during operation

  13. On the crystal energy and structure of A{sub 2}Ti{sub n}O{sub 2n+1} (A=Li, Na, K) titanates by DFT calculations and neutron diffraction

    SciTech Connect (OSTI)

    Catti, Michele; Pinus, Ilya; Scherillo, Antonella

    2013-09-15

    First-principles quantum-mechanical calculations (CRYSTAL09 code, B3LYP functional) were performed on alkali titanates A{sub 2}Ti{sub n}O{sub 2n+1} with layered structure (n=3,4,6). Monoclinic structural types with unshifted (P2{sub 1}/m) and with shifted (C2/m) layers were considered. Crystal energies and full structural details were obtained for all Li, Na, and K phases. Neutron diffraction data were collected on powder samples of P2{sub 1}/m-Li{sub 2}Ti{sub 3}O{sub 7} (a=9.3146(3), b=3.7522(1), c=7.5447(3) Å, β=97.611(4)°) and C2/m-K{sub 2}Ti{sub 4}O{sub 9} (a=18.2578(8), b=3.79160(9), c=12.0242(4) Å, β=106.459(4)°) and their structures were Rietveld-refined. Computed energies show the P2{sub 1}/m arrangement as favoured over the C2/m one for n=3, and the opposite holds for n=6. In the n=4 case the P2{sub 1}/m configuration is predicted to be more stable for Li and Na, and the C2/m one for K titanates. Analysis of Li–O and K–O crystal-chemical environments from experiment and theory shows that the alkali atom bonding is stabilized/destabilized in the different phases consistently with the energy trend. - Graphical abstract: Display Omitted - Highlights: • The P2{sub 1}/m structure-type is found to be more stable for A{sub 2}Ti{sub 3}O{sub 7} layer titanates. • The C2/m structure-type is found to be more stable for A{sub 2}Ti{sub 6}O{sub 13} layer titanates. • Tetratitanates are predicted to prefer the P2{sub 1}/m (Li and Na) or C2/m (K) structure. • Li–O and K–O bond distances follow a trend consistent with computed phase energies.

  14. Optical amplification in disordered electrooptic Tm{sup 3+} and Ho{sup 3+} codoped lanthanum-modified lead zirconate titanate ceramics and study of spectroscopy and communication between cations

    SciTech Connect (OSTI)

    Zhao, Hua; Zhang, Kun; Xu, Long; Sun, Fankui; Zhang, Jingwen; Chen, Xuesheng; Li, Kewen K.

    2014-02-21

    Rare earth doped electro-optic (EO) ceramics of lanthanum-modified lead zirconate titanate (PLZT) are promising in building multifunctional optical devices, by taking advantage of both EO effect and optical activity. In this work, the combination of the measured spectra of absorption and photoluminescence, the fluorescent decay, the calculated Judd-Ofelt parameters, and measured single pass gain in Tm{sup 3+}, Ho{sup 3+} codoped PLZT ceramics have marked them out as promising gain media in building electrically controllable lasers/optical amplifiers and other multifunctional devices. Optical energy storage was also observed in the optical amplification dynamics.

  15. Laboratory Scoping Tests Of Decontamination Of Hanford Waste Treatment Plant Low Activity Waste Off-Gas Condensate Simulant

    SciTech Connect (OSTI)

    Taylor-Pashow, Kathryn M.; Nash, Charles A.; Crawford, Charles L.; McCabe, Daniel J.; Wilmarth, William R.

    2014-01-21

    compatible with longterm tank storage and immobilization methods. For this new application, testing is needed to demonstrate acceptable treatment sorbents and precipitating agents and measure decontamination factors for additional radionuclides in this unique waste stream. The origin of this LAW Off-Gas Condensate stream will be the liquids from the Submerged Bed Scrubber (SBS) and the Wet Electrostatic Precipitator (WESP) from the LAW melter off-gas system. The stream is expected to be a dilute salt solution with near neutral pH, and will likely contain some insoluble solids from melter carryover. The soluble components are expected to be mostly sodium and ammonium salts of nitrate, chloride, and fluoride. This stream has not been generated yet and will not be available until the WTP begins operation, but a simulant has been produced based on models, calculations, and comparison with pilot-scale tests. One of the radionuclides that is volatile and expected to be in high concentration in this LAW Off-Gas Condensate stream is Technetium-99 ({sup 99}Tc). Technetium will not be removed from the aqueous waste in the Hanford WTP, and will primarily end up immobilized in the LAW glass by repeated recycle of the off-gas condensate into the LAW melter. Other radionuclides that are also expected to be in appreciable concentration in the LAW Off-Gas Condensate are {sup 129}I, {sup 90}Sr, {sup 137}Cs, and {sup 241}Am. This report discusses results of preliminary radionuclide decontamination testing of the simulant. Testing examined use of Monosodium Titanate (MST) to remove {sup 90}Sr and actinides, inorganic reducing agents for {sup 99}Tc, and zeolites for {sup 137}Cs. Test results indicate that excellent removal of {sup 99}Tc was achieved using Sn(II)Cl{sub 2} as a reductant, coupled with sorption onto hydroxyapatite, even in the presence of air and at room temperature. This process was very effective at neutral pH, with a Decontamination Factor (DF) >577 in two hours. It was less

  16. Topics: Discovering the lower limit to magnetic transport - MST...

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

    fluctuations. In conventional RFP plasmas - i.e., those formed by steady toroidal induction - a spectrum of modes arises through linear tearing instability from current profile...

  17. Overview of results from the MST reversed field pinch experiment

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

    ... MHD with the Hall term and gyro-viscosity shows that two-fluid effects tend to ... Since the mode amplitudes are dynamic over the sawtooth cycle, this provides a stringent ...

  18. ANALYSES OF HTF-48-12-20/24 (FEBRUARY, 2012) AND ARCHIVED HTF-E-05-021 TANK 48H SLURRY SAMPLES

    SciTech Connect (OSTI)

    Nash, C.; Peters, T.

    2012-08-02

    Personnel characterized a Savannah River National Laboratory (SRNL) archived sample of Tank 48H slurry (HTF-E-05-021) in addition to the composite of samples HTF-48-12-20 and HTF-48-12-24, which were both retrieved in February 2012. The combined February 2012 sample is referred to as HTF-48-12-20/24 in this report. The results from these analyses are compared with Tank 48H samples analyzed in 2003, 2004, and 2005. This work supports the effort to demonstrate copper-catalyzed peroxide oxidation (CCPO) of organic content in this material. The principal findings with respect to the chemical and physical characteristics of the most recent sample are: (1) The measured potassium tetraphenylborate (KTPB) solid concentration is 1.76 wt %; (2) Titanium was in line with 2004 and 2005 slurry measurements at 897 mg/L, it represents 0.1535 {+-} 0.0012 wt % monosodium titanate (MST); (3) The measured insoluble solids content was 1.467 wt %; (4) The free hydroxide concentration in the Tank 48H filtrate sample (1.02 {+-} 0.02 M) is close to the Tank 48H limit (1.0 M); (5) Carbonate reported by total inorganic carbon (TIC, 1.39 {+-} 0.03 M) is more than double the concentrations measured in past (2003-2005) samples; (6) The soluble potassium content (measured at 286 {+-} 23 mg/L) in the filtrate is in line with all past measurements; and (7) The measured {sup 137}Cs concentration is 7.81E + 08 {+-} 3.9E + 07 dpm/mL of slurry (1.33 {+-} 5% Ci/gallon or 3.18E + 05 {+-} 5% curies of {sup 137}Cs in the tank) in the slurry which is in agreement with the 2005 report of 3.14E + 05 {+-} 1.5% curies of {sup 137}Cs in the tank. The filtrate {sup 137}Cs concentration is 2.57E + 07 {+-} 2.6E + 05 dpm/mL. This result is consistent with previous results. Significant analytical data are summarized in Table 1.

  19. Formation enthalpies and heat capacities of rear earth titanates: RE{sub 2}TiO{sub 5} (RE=La, Nd and Gd)

    SciTech Connect (OSTI)

    Hayun, Shmuel; Navrotsky, Alexandra

    2012-03-15

    The formation enthalpies and heat capacities of orthorhombic rare earth titanates, RE{sub 2}TiO{sub 5} (RE=La, Nd and Gd), have been studied by high temperature differential scanning calorimetry (300-1473 K) and oxide-melt solution calorimetry. The RE{sub 2}TiO{sub 5} samples are stable in enthalpy with respect to their oxides and the pyrochlore RE{sub 2}Ti{sub 2}O{sub 7} phase. The general trend that has been demonstrated in other RE-ternary systems; decreasing thermodynamic stability with decreasing R{sub A}/R{sub B} was found to be valid for the RE{sub 2}TiO{sub 5}, and their enthalpies of formation from oxides become more negative with increasing RE{sup 3+} ionic radius. - Graphical abstract: Normalized enthalpy of formation for one RE{sup 3+} cation from the oxides for several RE ternary oxide systems vs. the cation radius ratio R{sub A}/R{sub B} (A=RE, B=Ti, Zr, P). All the RE ternary oxide systems are stable relative to constituent oxides, with increasing stability as R{sub A}/R{sub B} increases. The Roman numerals above the cations represent the coordination number. Highlights: Black-Right-Pointing-Pointer Formation enthalpies and heat capacities of RE{sub 2}TiO{sub 5} (RE=La, Nd and Gd) were determined. Black-Right-Pointing-Pointer Enthalpies of formation of RE{sub 2}TiO{sub 5} from oxides become more negative with increasing RE{sup 3+} ionic radius. Black-Right-Pointing-Pointer RE{sub 2}TiO{sub 5} phases are stable in enthalpy with respect to their oxides and the pyrochlore RE{sub 2}Ti{sub 2}O{sub 7} phases. Black-Right-Pointing-Pointer Thermodynamic stability of orthorhombic RE{sub 2}TiO{sub 5} decrease with increasing R{sub B} to R{sub A} ratio.

  20. CRITICAL REVIEW OF N, N{sup +}, N{sup +} {sub 2}, N{sup ++}, And N{sup ++} {sub 2} MAIN PRODUCTION PROCESSES AND REACTIONS OF RELEVANCE TO TITAN'S ATMOSPHERE

    SciTech Connect (OSTI)

    Dutuit, Odile; Thissen, Roland; Vuitton, Veronique; Canosa, Andre; Picard, Sebastien Le; Loison, Jean-Christophe; Ascenzi, Daniela; Tosi, Paolo; Franceschi, Pietro; Price, Stephen D.; Lavvas, Panayotis

    2013-02-15

    This paper is a detailed critical review of the production processes and reactions of N, N{sup +}, N{sup +} {sub 2}, N{sup ++}, and N{sup ++} {sub 2} of relevance to Titan's atmosphere. The review includes neutral, ion-molecule, and recombination reactions. The review covers all possible active nitrogen species under Titan's atmospheric conditions, specifically N{sub 2} (A {sup 3}{Sigma}{sup +} {sub u}), N ({sup 4} S), N ({sup 2} D), N ({sup 2} P), N{sup +} {sub 2}, N{sup +} ({sup 3} P), N{sup +} ({sup 1} D), N{sup ++} {sub 2}, and N{sup ++} species, and includes a critical survey of the reactions of N, N{sup +}, N{sup +} {sub 2}, N{sup ++}, and N{sup ++} {sub 2} with N{sub 2}, H{sub 2}, D{sub 2}, CH{sub 4}, C{sub 2}H{sub 2}, C{sub 2}H{sub 4}, C{sub 2}H{sub 6}, C{sub 3}H{sub 8} and the deuterated hydrocarbon analogs, as well as the recombination reactions of N{sup +} {sub 2}, N{sup +}, N{sup ++} {sub 2}, and N{sup ++}. Production processes, lifetimes, and quenching by collisions with N{sub 2} of all reactant species are reviewed. The N ({sup 4} S) state is reactive with radicals and its reactions with CH{sub 2}, CH{sub 3}, C{sub 2}H{sub 3}, and C{sub 2}H{sub 5} are reviewed. Metastable states N{sub 2} (A {sup 3}{Sigma}{sup +} {sub u}), N ({sup 2} D), and N ({sup 2} P) are either reactive or quenched by collisions with the target molecules reviewed. The reactions of N{sup +} ({sup 1} D) have similar rate constants as N{sup +} ({sup 3} P), but the product branching ratios differ significantly. Temperature effects and the role of the kinetic energy content of reactants are investigated. In all cases, experimental uncertainties of laboratory data are reported or estimated. Recommended values with uncertainties, or estimated values when no data are available, are given for rate constants and product branching ratios at 300 K and at the atmospheric temperature range of Titan (150-200 K for neutral reactions and 150 K for ion reactions).

  1. Titan Platform | Open Energy Information

    Open Energy Info (EERE)

    Wind Facility Status Proposed Developer Offshore Wind Power Systems of Texas Location Gulf of Mexico TX Coordinates 27.912, -96.833 Show Map Loading map......

  2. Titan_SP-1.pdf

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

    Tips For Getting Hired Tips For Getting Hired Successful candidates know it takes a little extra effort to get to the top. This one hour workshop introduces you to the Department of Energy, in addition to guiding you in creating a competitive Federal resume, it also covers veteran hiring options, and offers important tips to help prepare for the interview. So, If you are new to the Federal government hiring process or just want to improve your odds of getting that critical interview, this

  3. CHARACTERIZATION OF A PRECIPITATE REACTOR FEED TANK (PRFT) SAMPLE FROM THE DEFENSE WASTE PROCESSING FACILITY (DWPF)

    SciTech Connect (OSTI)

    Crawford, C.; Bannochie, C.

    2014-05-12

    A sample of from the Defense Waste Processing Facility (DWPF) Precipitate Reactor Feed Tank (PRFT) was pulled and sent to the Savannah River National Laboratory (SRNL) in June of 2013. The PRFT in DWPF receives Actinide Removal Process (ARP)/ Monosodium Titanate (MST) material from the 512-S Facility via the 511-S Facility. This 2.2 L sample was to be used in small-scale DWPF chemical process cell testing in the Shielded Cells Facility of SRNL. A 1L sub-sample portion was characterized to determine the physical properties such as weight percent solids, density, particle size distribution and crystalline phase identification. Further chemical analysis of the PRFT filtrate and dissolved slurry included metals and anions as well as carbon and base analysis. This technical report describes the characterization and analysis of the PRFT sample from DWPF. At SRNL, the 2.2 L PRFT sample was composited from eleven separate samples received from DWPF. The visible solids were observed to be relatively quick settling which allowed for the rinsing of the original shipping vials with PRFT supernate on the same day as compositing. Most analyses were performed in triplicate except for particle size distribution (PSD), X-ray diffraction (XRD), Scanning Electron Microscopy (SEM) and thermogravimetric analysis (TGA). PRFT slurry samples were dissolved using a mixed HNO3/HF acid for subsequent Inductively Coupled Plasma Atomic Emission Spectroscopy (ICPAES) and Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) analyses performed by SRNL Analytical Development (AD). Per the task request for this work, analysis of the PRFT slurry and filtrate for metals, anions, carbon and base were primarily performed to support the planned chemical process cell testing and to provide additional component concentrations in addition to the limited data available from DWPF. Analysis of the insoluble solids portion of the PRFT slurry was aimed at detailed characterization of these solids (TGA, PSD

  4. IMPACTS OF SMALL COLUMN ION EXCHANGE STREAMS ON DWPF GLASS FORMULATION: KT08, KT09, AND KT10-SERIES GLASS COMPOSITIONS

    SciTech Connect (OSTI)

    Fox, K.; Edwards, T.

    2011-04-26

    This report is the fourth in a series of studies of the impacts of the addition of Crystalline Silicotitanate (CST) and Monosodium Titanate (MST) from the Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) glass waste form and the applicability of the DWPF process control models. MST from the Salt Waste Processing Facility (SWPF) is also considered in the study. The KT08-series of glasses was designed to evaluate any impacts of the inclusion of uranium and thorium in glasses containing the SCIX components. The KT09-series of glasses was designed to study the effect of increasing Al{sub 2}O{sub 3} and K{sub 2}O concentrations on the propensity for crystallization of titanium containing phases in high TiO{sub 2} concentration glasses. Earlier work on the KT05-series glasses recommended that the impact of these two components be studied further. Increased Al{sub 2}O{sub 3} concentrations have been shown to improve the properties and performance of high waste loading glasses, and K{sub 2}O has been reported to improve the retention of TiO{sub 2} in silicate glasses. The KT10-series of compositions was designed to evaluate any impacts of the SCIX components at concentrations 50% higher than currently projected.a The glasses were fabricated in the laboratory and characterized to identify crystallization, to verify chemical compositions, to measure viscosity, and to measure durability. Liquidus temperature measurements for the KT10-series glasses are underway and will be reported separately. All but one of the KT08-series glasses were found to be amorphous by X-ray diffraction (XRD). One of the slowly cooled glasses contained a small amount of trevorite, which had no practical impact on the durability of the glass and is typically found in DWPF-type glasses. The measured Product Consistency Test (PCT) responses for the KT08-series glasses are well predicted by the DWPF models. The viscosities of the KT08-series glasses were generally

  5. Results Of Routine Strip Effluent Hold Tank And Decontaminated Salt Solution Hold Tank Samples From Modular Caustic-Side Solvent Extraction Unit During Macrobatch 5 Operations

    SciTech Connect (OSTI)

    Peters, T. B.; Fondeur, F. F.

    2013-04-30

    Strip Effluent Hold Tank (SEHT) and Decontaminated Salt Solution Hold Tank (DSSHT) samples from several of the ''microbatches'' of Integrated Salt Disposition Project (ISDP) Salt Batch (''Macrobatch'') 5 have been analyzed for {sup 238}Pu, {sup 90}Sr, {sup 137}Cs, and by Inductively Coupled Plasma Emission Spectroscopy (ICPES). The results indicate good decontamination performance within process design expectations. While the data set is sparse, the results of this set and the previous set of results for Macrobatch 4 samples indicate generally consistent operations. The DSSHT samples show continued presence of titanium, likely from leaching of the monosodium titanate in the Actinide Removal process (ARP).

  6. PAPER STUDY EVALUATIONS OF THE INTRODUCTION OF SMALL COLUMN ION EXCHANGE WASTE STREAMS TO THE DEFENSE WASTE PROCESSING FACILITY

    SciTech Connect (OSTI)

    Fox, K.; Edwards, T.; Stone, M.; Koopman, D.

    2010-06-29

    The objective of this paper study is to provide guidance on the impact of Monosodium Titanate (MST) and Crystalline Silicotitanate (CST) streams from the Small Column Ion Exchange (SCIX) process on the Defense Waste Processing Facility (DWPF) flowsheet and glass waste form. A series of waste processing scenarios was evaluated, including projected compositions of Sludge Batches 8 through 17 (SB8 through SB17), MST additions, CST additions to Tank 40 or to a sludge batch preparation tank (Tank 42 or Tank 51, referred to generically as Tank 51 in this report), streams from the Salt Waste Processing Facility (SWPF), and two canister production rates. A wide array of potential glass frit compositions was used to support this assessment. The sludge and frit combinations were evaluated using the predictive models in the current DWPF Product Composition Control System (PCCS). The results were evaluated based on the number of frit compositions available for a particular sludge composition scenario. A large number of candidate frit compositions (e.g., several dozen to several hundred) is typically a good indicator of a sludge composition for which there is flexibility in forming an acceptable waste glass and meeting canister production rate commitments. The MST and CST streams will significantly increase the concentrations of certain components in glass, such as Nb{sub 2}O{sub 5}, TiO{sub 2}, and ZrO{sub 2}, to levels much higher than have been previously processed at DWPF. Therefore, several important assumptions, described in detail in the report, had to be made in performing the evaluations. The results of the paper studies, which must be applied carefully given the assumptions made concerning the impact of higher Ti, Zr, and Nb concentrations on model validity, provided several observations: (1) There was difficulty in identifying a reasonable number of candidate frits (and in some cases an inability to identify any candidate frits) when a waste loading of 40% is

  7. THERMAL MODELING ANALYSIS OF CST MEDIA IN THE SMALL COLUMN ION EXCHANGE PROJECT

    SciTech Connect (OSTI)

    Lee, S.

    2010-11-01

    Models have been developed to simulate the thermal characteristics of Crystalline Silicotitanate (CST) ion exchange media fully loaded with radioactive cesium in a column configuration and distributed within a waste storage tank. This work was conducted to support the Small Column Ion Exchange (SCIX) program which is focused on processing dissolved, high-sodium salt waste for the removal of specific radionuclides (including Cs-137, Sr-90, and actinides) within a High Level Waste (HLW) storage tank at the Savannah River Site. The SCIX design includes CST columns inserted and supported in the tank top risers for cesium removal. Temperature distributions and maximum temperatures across the column were calculated with a focus on process upset conditions. A two-dimensional computational modeling approach for the in-column ion-exchange domain was taken to include conservative, bounding estimates for key parameters such that the results would provide the maximum centerline temperatures achievable under the design configurations using a feed composition known to promote high cesium loading on CST. One salt processing scenario includes the transport of the loaded (and possibly ground) CST media to the treatment tank floor. Therefore, additional thermal modeling calculations were conducted using a three-dimensional approach to evaluate temperature distributions for the entire in-tank domain including distribution of the spent CST media either as a mound or a flat layer on the tank floor. These calculations included mixtures of CST with HLW sludge or loaded Monosodium Titanate (MST) media used for strontium/actinide sorption. The current full-scale design for the CST column includes one central cooling pipe and four outer cooling tubes. Most calculations assumed that the fluid within the column was stagnant (i.e. no buoyancy-induced flow) for a conservative estimate. A primary objective of these calculations was to estimate temperature distributions across packed CST beds

  8. Titan Energy Systems Ltd | Open Energy Information

    Open Energy Info (EERE)

    India Zip: 500015 Sector: Solar Product: One of the leading Indian manufacturers and exporters of Solar Photovolatic modules. Coordinates: 17.46071, 78.49298 Show Map Loading...

  9. Titan I Wind Farm | Open Energy Information

    Open Energy Info (EERE)

    Wind energy Facility Type Commercial Scale Wind Facility Status In Service Owner BP Alternative EnergyClipper Developer BP Alternative EnergyClipper Energy Purchaser...

  10. Flexoelectricity in barium strontium titanate thin film

    SciTech Connect (OSTI)

    Kwon, Seol Ryung; Huang, Wenbin; Yuan, Fuh-Gwo; Jiang, Xiaoning; Shu, Longlong; Maria, Jon-Paul

    2014-10-06

    Flexoelectricity, the linear coupling between the strain gradient and the induced electric polarization, has been intensively studied as an alternative to piezoelectricity. Especially, it is of interest to develop flexoelectric devices on micro/nano scales due to the inherent scaling effect of flexoelectric effect. Ba{sub 0.7}Sr{sub 0.3}TiO{sub 3} thin film with a thickness of 130 nm was fabricated on a silicon wafer using a RF magnetron sputtering process. The flexoelectric coefficients of the prepared thin films were determined experimentally. It was revealed that the thin films possessed a transverse flexoelectric coefficient of 24.5 μC/m at Curie temperature (∼28 °C) and 17.44 μC/m at 41 °C. The measured flexoelectric coefficients are comparable to that of bulk BST ceramics, which are reported to be 10–100 μC/m. This result suggests that the flexoelectric thin film structures can be effectively used for micro/nano-sensing devices.

  11. Graph algorithms in the titan toolkit.

    SciTech Connect (OSTI)

    McLendon, William Clarence, III; Wylie, Brian Neil

    2009-10-01

    Graph algorithms are a key component in a wide variety of intelligence analysis activities. The Graph-Based Informatics for Non-Proliferation and Counter-Terrorism project addresses the critical need of making these graph algorithms accessible to Sandia analysts in a manner that is both intuitive and effective. Specifically we describe the design and implementation of an open source toolkit for doing graph analysis, informatics, and visualization that provides Sandia with novel analysis capability for non-proliferation and counter-terrorism.

  12. Titan Electric Corporation | Open Energy Information

    Open Energy Info (EERE)

    Place: Peabody, Massachusetts Zip: 01960 Region: Greater Boston Area Sector: Wind energy Product: Design and installation of small-scale renewable energy systems Website:...

  13. Hydrothermal crystallization of Na{sub 2}Ti{sub 6}O{sub 13}, Na{sub 2}Ti{sub 3}O{sub 7}, and Na{sub 16}Ti{sub 10}O{sub 28} in the NaOH-TiO{sub 2}-H{sub 2}O system at a temperature of 500 deg. C and a pressure of 0.1 GPa: The structural mechanism of self-assembly of titanates from suprapolyhedral clusters

    SciTech Connect (OSTI)

    Hyushin, G. D.

    2006-07-15

    An increase in the NaOH concentration in the NaOH-TiO{sub 2} (rutile)-H{sub 2}O system at a temperature of 500 deg. C and a pressure of 0.1 GPa leads to the crystallization R-TiO{sub 2} + Na{sub 2}Ti{sub 6}O{sub 13} {sup {yields}} Na{sub 2}Ti{sub 3}O{sub 7} {sup {yields}} Na{sub 16}Ti{sub 10}O{sub 28}. Crystals of the Na{sub 2}Ti{sub 6}O{sub 13} titanate (space group C2/m) have the three-dimensional framework structure Ti{sub 6}O{sub 13}. The structure of the Na{sub 2}Ti{sub 3}O{sub 7} titanate (space group P2{sub 1}/m) contains the two-dimensional layers Ti{sub 3}O{sub 7}. The structure of the Na{sub 16}Ti{sub 10}O{sub 28} titanate (space group P-1) is composed of the isolated ten-polyhedron cluster precursors Ti{sub 10}O{sub 28}. In all the structures, the titanium atoms have an octahedral coordination (MTiO{sub 6}). The matrix self-assembly of the Na{sub 2}Ti{sub 6}O{sub 13} and Na{sub 2}Ti{sub 3}O{sub 7} (Na{sub 4}Ti{sub 6}O{sub 14}) crystal structures from Na{sub 4}M{sub 12} invariant precursors is modeled. These precursors are clusters consisting of twelve M polyhedra linked through the edges. It is demonstrated that the structurally rigid precursors Na{sub 4}M{sub 12} control all processes of the subsequent evolution of the crystal-forming titanate clusters. The specific features of the self-assembly of the Na{sub 2}Ti{sub 3}O{sub 7} structure that result from the additional incorporation of twice the number of sodium atoms into the composition of the high-level clusters are considered.

  14. MST e-News December 2015 (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    Authors: Kippen, Karen Elizabeth 1 + Show Author Affiliations Los Alamos National Lab. (LANL), Los Alamos, NM (United States) Publication Date: 2015-12-15 OSTI Identifier: ...

  15. MST-12 485-REC-R00 Treatment of Evaporator Bottoms Issued July 13 1984.pdf

    Office of Environmental Management (EM)

  16. MST e-News September 2014 (Technical Report) | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    of DOE's Office of Scientific and Technical Information (OSTI) and is provided as a public service. Visit OSTI to utilize additional information resources in energy science...

  17. Global confinement and discrete dynamo activity in the MST reversed-field pinch

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

    Mold Manufacturing | Department of Energy Global Wind Day 2016 - AMO's Role in Applying 3D Printing to Wind Blade Mold Manufacturing Global Wind Day 2016 - AMO's Role in Applying 3D Printing to Wind Blade Mold Manufacturing June 14, 2016 - 4:52pm Addthis Global Wind Day 2016 – AMO’s Role in Applying 3D Printing to Wind Blade Mold Manufacturing Global Wind Day is a worldwide event that occurs annually on June 15 and is dedicated to discovering the possibilities wind holds to reshape

  18. SAMPLE RESULTS FROM THE INTEGRATED SALT DISPOSITION PROGRAM MACROBATCH 5 TANK 21H QUALIFICATION MST, ESS AND PODD SAMPLES

    SciTech Connect (OSTI)

    Peters, T.; Fink, S.

    2012-04-24

    Savannah River National Laboratory (SRNL) performed experiments on qualification material for use in the Integrated Salt Disposition Program (ISDP) Batch 5 processing. This qualification material was a composite created from recent samples from Tank 21H and archived samples from Tank 49H to match the projected blend from these two tanks. Additionally, samples of the composite were used in the Actinide Removal Process (ARP) and extraction-scrub-strip (ESS) tests. ARP and ESS test results met expectations. A sample from Tank 21H was also analyzed for the Performance Objectives Demonstration Document (PODD) requirements. SRNL was able to meet all of the requirements, including the desired detection limits for all the PODD analytes. This report details the results of the Actinide Removal Process (ARP), Extraction-Scrub-Strip (ESS) and Performance Objectives Demonstration Document (PODD) samples of Macrobatch (Salt Batch) 5 of the Integrated Salt Disposition Program (ISDP).

  19. Fast pyrobolometers for measurements of plasma heat fluxes and radiation losses in the MST Reversed Field Pinch

    SciTech Connect (OSTI)

    Fiksel, G.; Frank, J.; Holly, D.

    1993-01-07

    Two types of fast bolometers are described for the plasma energy transport study in the Madison Symmetric Torus plasma confinement device. Both types use pyrocrystals of LiTaO[sub 3] or LiNbO[sub 3] as the sensors. One type is used for measurements of the radiated heat losses and is situated at the vacuum shell inner surface. Another type is insertable in the plasma and measures the plasma particle heat flux. The frequency response of the bolometers is measured to be in the 150--200 kHz range. The range of the measured power fluxes is 0.1 W/cm[sup 2] 10 kW/cm[sup 2] and can be adjusted by changing the size of the entrance aperture. The lower limit is determined by the amplifier noise and the frequency bandwidth, the higher limit by destruction of the bolometer sensor.

  20. Fast pyrobolometers for measurements of plasma heat fluxes and radiation losses in the MST Reversed Field Pinch

    SciTech Connect (OSTI)

    Fiksel, G.; Frank, J.; Holly, D.

    1993-01-07

    Two types of fast bolometers are described for the plasma energy transport study in the Madison Symmetric Torus plasma confinement device. Both types use pyrocrystals of LiTaO{sub 3} or LiNbO{sub 3} as the sensors. One type is used for measurements of the radiated heat losses and is situated at the vacuum shell inner surface. Another type is insertable in the plasma and measures the plasma particle heat flux. The frequency response of the bolometers is measured to be in the 150--200 kHz range. The range of the measured power fluxes is 0.1 W/cm{sup 2} 10 kW/cm{sup 2} and can be adjusted by changing the size of the entrance aperture. The lower limit is determined by the amplifier noise and the frequency bandwidth, the higher limit by destruction of the bolometer sensor.

  1. Stabilization of lead lithium iron tungstate with adding barium titanate

    SciTech Connect (OSTI)

    Lu, C.; Fang, B.

    1997-01-01

    The kinetics of formation, phase stabilities, and dielectric constants of Pb(Li{sub 1/4}Fe{sub 1/4}W{sub 1/2})O{sub 3} and BaTiO{sub 3}-added Pb(Li{sub 1/4}Fe{sub 1/4}W{sub 1/2})O{sub 3} have been compared. The addition of 2 mol{percent} BaTiO{sub 3} in Pb(Li{sub 1/4}Fe{sub 1/4}W{sub 1/2})O{sub 3} was confirmed to promote the complete formation of the perovskite phase at 700{degree}C. Also the thermal stability of the perovskite phase was significantly enhanced, which results in an increase of the dielectric permittivity. {copyright} {ital 1997 Materials Research Society.}

  2. Crystallographic changes in lead zirconate titanate due to neutron irradiation

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

    Henriques, Alexandra; Graham, Joseph T.; Landsberger, Sheldon; Ihlefeld, Jon F.; Brennecka, Geoff L.; Brown, Donald W.; Forrester, Jennifer S.; Jones, Jacob L.

    2014-11-17

    Piezoelectric and ferroelectric materials are useful as the active element in non-destructive monitoring devices for high-radiation areas. Here, crystallographic structural refinement (i.e., the Rietveld method) is used to quantify the type and extent of structural changes in PbZr0.5Ti0.5O3 after exposure to a 1 MeV equivalent neutron fluence of 1.7 × 1015 neutrons/cm2. The results show a measurable decrease in the occupancy of Pb and O due to irradiation, with O vacancies in the tetragonal phase being created preferentially on one of the two O sites. The results demonstrate a method by which the effects of radiation on crystallographic structure maymore » be investigated.« less

  3. Crystallographic changes in lead zirconate titanate due to neutron irradiation

    SciTech Connect (OSTI)

    Henriques, Alexandra; Graham, Joseph T.; Landsberger, Sheldon; Ihlefeld, Jon F.; Brennecka, Geoff L.; Brown, Donald W.; Forrester, Jennifer S.; Jones, Jacob L.

    2014-11-15

    Piezoelectric and ferroelectric materials are useful as the active element in non-destructive monitoring devices for high-radiation areas. Here, crystallographic structural refinement (i.e., the Rietveld method) is used to quantify the type and extent of structural changes in PbZr{sub 0.5}Ti{sub 0.5}O{sub 3} after exposure to a 1 MeV equivalent neutron fluence of 1.7 × 10{sup 15} neutrons/cm{sup 2}. The results show a measurable decrease in the occupancy of Pb and O due to irradiation, with O vacancies in the tetragonal phase being created preferentially on one of the two O sites. The results demonstrate a method by which the effects of radiation on crystallographic structure may be investigated.

  4. A modified method for barium titanate nanoparticles synthesis

    SciTech Connect (OSTI)

    Ashiri, R.; Nemati, Ali; Sasani Ghamsari, M.; Sanjabi, S.; Aalipour, M.

    2011-12-15

    Graphical abstract: TEM micrograph of BaTiO{sub 3} powders synthesized at 800 Degree-Sign C for 1 h and SAED pattern (inset) of BaTiO{sub 3} powders. In this research, a modified, cost efficient and quick sol-gel procedure was used for preparation of BaTiO{sub 3} nanoparticles. Highlights: Black-Right-Pointing-Pointer A modified process was used for preparation. Black-Right-Pointing-Pointer The modified process led to preparation of finer BaTiO{sub 3} nanoparticles in shorter period of time and lower temperature contrary to previous researches. Black-Right-Pointing-Pointer The proposed procedure seems to be more preferable for mass production. -- Abstract: In this research, a modified, cost effective sol-gel procedure applied to synthesize BaTiO{sub 3} nanoparticles. XRD and electron microscopy (SEM and TEM) applied for microstructural characterization of powders. The obtained results showed that the type of precursors, their ratio and the hydrolysis conditions had a great effect on time, temperature and therefore the costs of the synthesis process. By selection, utilization of optimized precursor's type, hydrolysis conditions, fine cubic BaTiO{sub 3} nanoparticles were synthesized at low temperature and in short time span (1 h calcination at 800 Degree-Sign C). The proposed procedure seems to be more preferable for mass production. The result indicated that the polymorphic transformation to tetragonal (ferroelectric characteristic) occurred at 900 Degree-Sign C, which might be an indication of being nanosized.

  5. Microstructure tuning and magnetism switching of ferroelectric barium titanate

    SciTech Connect (OSTI)

    Zhou, Wenliang; Deng, Hongmei; Ding, Nuofan; Yu, Lu; Yue, Fangyu; Yang, Pingxiong; Chu, Junhao

    2015-09-15

    Single-crystal and polycrystal BaTiO{sub 3} (BTO) materials synthesized by the physical and chemical methods, respectively, have been studied based on microstructural characterizations and magnetic measurements. The results of X-ray diffraction and Raman scatting spectra show that a single crystal tetragonal to polycrystalline pseudo-cubic structure transformation occurs in BTO ferroelectrics, dependent of growth conditions and interface effects. High-resolution transmission electron microscope data indicate that the as-prepared BTO/SrTiO{sub 3} (001) and BTO/SrRuO{sub 3}/SrTiO{sub 3} (001) heterostructures are highly c-axis oriented with atomic sharp interfaces. Lattice defects (i.e., edge-type misfit dislocations and stacking faults) in the heterostructures could be identified clearly and showed tunable with the variations of interface strain. Furthermore, the effects of vacancy defects on magnetic properties of BTO are discussed, which shows a diamagnetism–ferromagnetism switching as intrinsic vacancies increase. This work opens up a possible avenue to prepare magnetic BTO ferroelectrics. - Highlights: • Structure of BTO is tunable, depending on growth conditions and interface strain. • STEM–EDX data indicate the presence of lattice defects in BTO ferroelectrics. • BTO magnetism could be controlled by defects showing dia-ferromagnetism switching. • BTO with more vacancies shows RTFM, as evidence of vacancy magnetism effects.

  6. Cuprate-titanate superconductor and method for making

    DOE Patents [OSTI]

    Toreki, R.; Poeppelmeier, K.; Dabrowski, B.

    1995-05-23

    A new copper oxide superconductor of the formula Ln{sub 1{minus}x}M{sub x}Sr{sub 2}Cu{sub 3{minus}y}Ti{sub y}O{sub 7+{delta}} is disclosed, and exhibits a {Tc} of 60 K with deviations from linear metallic behavior as high as 130 K. 2 Figs.

  7. Crystallographic changes in lead zirconate titanate due to neutron irradiation

    SciTech Connect (OSTI)

    Henriques, Alexandra; Graham, Joseph T.; Landsberger, Sheldon; Ihlefeld, Jon F.; Brennecka, Geoff L.; Brown, Donald W.; Forrester, Jennifer S.; Jones, Jacob L.

    2014-11-17

    Piezoelectric and ferroelectric materials are useful as the active element in non-destructive monitoring devices for high-radiation areas. Here, crystallographic structural refinement (i.e., the Rietveld method) is used to quantify the type and extent of structural changes in PbZr0.5Ti0.5O3 after exposure to a 1 MeV equivalent neutron fluence of 1.7 1015 neutrons/cm2. The results show a measurable decrease in the occupancy of Pb and O due to irradiation, with O vacancies in the tetragonal phase being created preferentially on one of the two O sites. The results demonstrate a method by which the effects of radiation on crystallographic structure may be investigated.

  8. X-ray diffraction study of crystalline barium titanate ceramics

    SciTech Connect (OSTI)

    Zali, Nurazila Mat; Mahmood, Che Seman; Mohamad, Siti Mariam; Foo, Choo Thye; Murshidi, Julie Adrianny

    2014-02-12

    In this study, BaTiO{sub 3} ceramics have been prepared via solid-state reaction method. The powders were calcined for 2 hours at different temperatures ranging from 600C to 1200C. Using X-ray diffraction with a Rietveld analysis, the phase formation and crystal structure of the BaTiO{sub 3} powders were studied. Change in crystallite size and tetragonality as a function of calcination temperature were also discussed. It has been found that the formation of pure perovskite phase of BaTiO{sub 3} began at calcination condition of 1000 C for 2 hours. The crystal structure of BaTiO{sub 3} formed is in the tetragonal structure. The second phases of BaCO{sub 3} and TiO{sub 2} existed with calcination temperature below 1000 C. Purity, crystallite size and tetragonality of BaTiO{sub 3} powders were found to increase with increasing calcination temperature.

  9. Electronic structure basis for the titanic magnetoresistance in WTe?

    SciTech Connect (OSTI)

    Pletikosic, I.; Ali, Mazhar N.; Fedorov, A. V.; Cava, R. J.; Valla, T.

    2014-11-19

    The electronic structure basis of the extremely large magnetoresistance in layered non-magnetic tungsten ditelluride has been investigated by angle-resolved photoelectron spectroscopy. Hole and electron pockets of approximately the same size were found at the Fermi level, suggesting that carrier compensation should be considered the primary source of the effect. The material exhibits a highly anisotropic, quasi one-dimensional Fermi surface from which the pronounced anisotropy of the magnetoresistance follows. A change in the Fermi surface with temperature was found and a high-density-of-states band that may take over conduction at higher temperatures and cause the observed turn-on behavior of the magnetoresistance in WTe? was identified.

  10. Electronic structure basis for the titanic magnetoresistance in WTe?

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

    Pletikosic, I.; Ali, Mazhar N.; Fedorov, A. V.; Cava, R. J.; Valla, T.

    2014-11-19

    The electronic structure basis of the extremely large magnetoresistance in layered non-magnetic tungsten ditelluride has been investigated by angle-resolved photoelectron spectroscopy. Hole and electron pockets of approximately the same size were found at the Fermi level, suggesting that carrier compensation should be considered the primary source of the effect. The material exhibits a highly anisotropic, quasi one-dimensional Fermi surface from which the pronounced anisotropy of the magnetoresistance follows. A change in the Fermi surface with temperature was found and a high-density-of-states band that may take over conduction at higher temperatures and cause the observed turn-on behavior of the magnetoresistance inmoreWTe? was identified.less