National Library of Energy BETA

Sample records for tc tc tc

  1. High Tc Superconductivity

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

    by C. Kim (SSRL), D. H. Lu (Stanford), K. M. Shen (Stanford) and Z.-X. Shen (Stanford/SSRL) Extensive research efforts to study the novel electronic properties of high-Tc superconductors and their related materials by angle-resolved photoemission spectroscopy at a recently commissioned Beam Line 5-4 (led by Z.-X. Shen) continue to be successful, producing many important results. These results, which are highlighted by five articles recently published in Physical Review Letters and one in

  2. Tc-99 Ion Exchange Resin Testing

    SciTech Connect (OSTI)

    Valenta, Michelle M.; Parker, Kent E.; Pierce, Eric M.

    2010-08-01

    Pacific Northwest National Laboratory was contracted by CHPRC to evaluate the release of 99Tc from spent resin used to treat water from well 299-W15-765 and stored for several years. The key questions to be answered are: 1) does 99Tc readily release from the spent ion exchange resin after being in storage for several years; 2) if hot water stripping is used to remove the co-contaminant carbon tetrachloride, will 99Tc that has been sequestered by the resin be released; and 3) can spent resin be encapsulated into a cementitious waste form; if so, how much 99Tc would be released from the weathering of the monolith waste form? The results from the long term stability leach test results confirm that the resin is not releasing a significant amount of the sequestered 99Tc, evident by the less than 0.02% of the total 99Tc loaded being identified in the solution. Furthermore, it is possible that the measured 99Tc concentration is the result of 99Tc contained in the pore spaces of the resin. In addition to these results, analyses conducted to examine the impact of hot water on the release of 99Tc suggest that only a small percentage of the total is being released. This suggest that hot water stripping to remove carbon tetrachloride will not have a significant affect on the resins ability to hold-on to sequestered 99Tc. Finally, encapsulation of spent resin in a cementitious material may be a viable disposal option, but additional tests are needed to examine the extent of physical degradation caused by moisture loss and the effect this degradation process can have on the release of 99Tc.

  3. Tc-99m Labeled carrier for imaging

    DOE Patents [OSTI]

    Henze, Eberhard

    1984-01-01

    Novel radionuclide imaging agents, having particular application for lymphangiography are provided by non-covalently binding Tc-99m to a pharmaceutically acceptable cross-linked polysaccharide. Upon injection of the Tc-99m labeled polysaccharide into the blood stream, optimum contrast can be obtained within one hour.

  4. Scintillating 99Tc Selective Ion Exchange Resins

    SciTech Connect (OSTI)

    Mitchell Greenhalgh; Richard D. Tillotson

    2012-07-01

    Scintillating technetium (99Tc) selective ion exchange resins have been developed and evaluated for equilibrium capacities and detection efficiencies. These resins can be utilized for the in-situ concentration and detection of low levels of pertechnetate anions (99TcO4-) in natural waters. Three different polystyrene type resin support materials were impregnated with varying amounts of tricaprylmethylammonium chloride (Aliquat 336) extractant, several different scintillating fluors and wavelength shifters. The prepared resins were contacted batch-wise to equilibrium over a wide range of 99TcO4- concentrations in natural water. The measured capacities were used to develop Langmuir adsorption isotherms for each resin. 99Tc detection efficiencies were determined and up to 71.4 ± 2.6% was achieved with some resins. The results demonstrate that a low level detection limit for 99TcO4- in natural waters can be realized.

  5. Trexler Climate Energy Services TC ES | Open Energy Information

    Open Energy Info (EERE)

    Trexler Climate Energy Services TC ES Jump to: navigation, search Name: Trexler Climate + Energy Services (TC + ES) Place: Portland, Oregon Zip: 97214 Sector: Services Product:...

  6. Technetium Removal Using Tc-Goethite Coprecipitation

    SciTech Connect (OSTI)

    Um, Wooyong; Wang, Guohui; Jung, Hun Bok; Peterson, Reid A.

    2013-11-18

    This report describes the results from laboratory tests performed at Pacific Northwest National Laboratory for the U.S. Department of Energy (DOE) EM-31 Support Program (EMSP) subtask, “Low temperature waste forms coupled with technetium removal using an alternative immobilization process such as Fe(II) treated-goethite precipitation” to increase our understanding of 99Tc long-term stability in goethite mineral form and the process that controls the 99Tc(VII) reduction and removal by the final Fe (oxy)hydroxide forms. The overall objectives of this task were to 1) evaluate the transformation process of Fe (oxy)hydroxide solids to the more crystalline goethite (α-FeOOH) mineral for 99Tc removal and 2) determine the mechanism that limits 99Tc(IV) reoxidation in Fe(II)-treated 99Tc-goethite mineral and 3) evaluate whether there is a long-term 99Tcoxidation state change for Tc sequestered in the iron solids.

  7. Insights into Stabilization of the 99TcVO Core for Synthesis of 99TcVO Compounds

    SciTech Connect (OSTI)

    McGregor, Donna; Burton-Pye, Benjamin P.; Lukens, Wayne W.; Howell, Robertha C.; Francesconi, Lynn C.

    2014-01-01

    Synthesis of technetium-99 (99Tc; t1/2: 2.1 105 years, max: 253 keV) materials is of importance in studies of the nuclear fuel cycle where Tc is a major fission product (6percent thermal yield from 235U and 239Pu), in understanding radioactive tank waste composition, and in identifying 99mTc compounds for nuclear medicine imaging. One of the most useful synthetic starting materials, (NBu4)TcOCl4, is susceptible to disproportionation in water to form TcO4 and TcIV species, especially TcO2 2H2O. This unwanted reaction is especially problematic when working with ligands bearing hard donor atoms, such as oxygen, where the stability with the soft TcV=O3+ core may be low. Polyoxometalates (POMs) are such ligands. They possess defect sites with four hard oxygen atoms and show low (ca. 108) stability constants with transition metals. Tc complexes of POMs are molecular-level models for Tc metal oxide solid-state materials and can provide information on coordination and redox environments of metal oxides that stabilize low-valent Tc. In order to synthesize pure Tc POM complexes [TcVO(1-P2W17O61)]7 (TcVO-1) and [TcVO(2-P2W17O61)]7 (TcVO-2) from (NBu4)TcOCl4, we have identified strategies that minimize formation of TcIV species and optimize the formation of pure TcV species. The parameters that we consider are the amount of ethylene glycol, which is employed as a transfer ligand to prevent hydrolysis of (NBu4)TcOCl4, and the precipitating agent. The TcIV species that contaminates the non-optimized syntheses is likely a TcIV -oxido-bridged dimer [TcIV-(-O)2-TcIV]. We also employ a novel procedure where the 2 ligand is photoactivated and reduced (in the presence of a sacrificial electron donor) to subsequently reduce TcVIIO4 to an isolatable TcVO-2 product that is remarkably free of TcIV.

  8. Development of Tc(IV)-Incorporated Fe Minerals to Enhance 99Tc Retention in Glass Waste Form

    SciTech Connect (OSTI)

    Um, Wooyong; Luksic, Steven A.; Wang, Guohui; Kim, Dong-Sang; Schweiger, Michael J.; Hrma, Pavel R.; Kruger, Albert A.

    2015-03-17

    Iron minerals have been considered to be good hosts for Tc immobilization because the Tc(IV) ion substitutes for Fe(III) in the crystal structure of the Fe oxide due to similarities in (1) cation size [Tc(IV) = 78.5 pm ; Fe(III) = 69 or 78.5 pm], (2) metal-oxygen interatomic distance (Tc—O = 0.199 nm, Fe—O = 0.203 nm), (3) number of coordinating oxygen atoms (both 6-fold coordinated), and (4) the redox potential (Eh=ca. +20 mV at pH = 7) for a redox couple between Tc(VII)/Tc(IV) and Fe(III)/Fe(II). Magnetite, maghemite, and trevorite are iron oxide minerals and all belong to spinel mineral group. Laboratory testing shows that Tc can be removed from aqueous waste solutions by a process of Tc reduction from Tc(VII) to Tc(IV) followed by co-precipitation with iron oxide minerals during recrystallization of Fe(OH)2(s) used as an initial solid precursor. X-ray absorption near edge structure (XANES) spectroscopy confirmed that Tc was in the +4 oxidation state in final Tc-Fe minerals. The Tc-incorporated Fe minerals were also tested for Tc retention in glass melts at different temperatures between 600 – 1,000 oC in a furnace. After being cooled in air, the solid glass specimens collected at different temperatures were analyzed for Tc oxidation state using XANES and Tc retention using liquid scintillation counting (LSC). Even though Tc(IV) started to reoxidize at 600 oC, Tc retention in the final glass specimen prepared with Tc-incorporated Fe mineral even at high temperatures was at least two times higher than glass prepared with KTcO4 salt. Higher Tc retention in glass is considered to result from limited and delayed Tc volatilization process due to Fe mineral encapsulation for Tc. Therefore, the results showing the presence of Tc(IV) in the Fe mineral structure indicate strong possibility to enhance Tc retention in borosilicate glass as well as to reduce the remediation costs at the Hanford Site.

  9. ARM - Campaign Instrument - tc-bc

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

    govInstrumentstc-bc Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Campaign Instrument : Total Carbon and Black Carbon Concentrations on Filter Samples (TC-BC) Instrument Categories Aerosols, Atmospheric Carbon Campaigns Aerosol IOP [ Download Data ] Southern Great Plains, 2003.05.01 - 2003.05.31 Primary Measurements Taken The following measurements are those considered scientifically relevant. Refer to the datastream (netcdf) file headers for

  10. Pretreatment of Tc-Containing Waste and Its Effect on Tc-99 Leaching From Grouts

    SciTech Connect (OSTI)

    Aloy, Albert; Kovarskaya, Elena N.; Harbour, John R.; Langton, Christine A.; Holtzscheiter, E. William

    2007-07-01

    A salt solution (doped with Tc-99), that simulates the salt waste stream to be processed at the Saltstone Production Facility, was immobilized in grout waste forms with and without (1) ground granulated blast furnace slag and (2) pretreatment with iron salts. The degree of immobilization of Tc-99 was measured through monolithic and crushed grout leaching tests. Although Fe (+2) was shown to be effective in reducing Tc-99 to the +4 state, the strong reducing nature of the blast furnace slag present in the grout formulation dominated the reduction of Tc-99 in the cured grouts. An effective diffusion coefficient of 4.75 x 10{sup -12} (Leach Index of 11.4) was measured using the ANSI/ANS-16.1 protocol. The leaching results show that, even in the presence of a concentrated salt solution, blast furnace slag can effectively reduce pertechnetate to the immobile +4 oxidation state. The measured diffusivity was introduced into a flow and transport model (PORFLOW) to calculate the release of Tc-99 from a Saltstone Vault as a function of hydraulic conductivity of the matrix. (authors)

  11. Electromagnetics in high-{Tc} superconductors

    SciTech Connect (OSTI)

    Ma, J.G.; Wolff, I.

    1996-04-01

    The behavior of electromagnetic fields in high-{Tc} superconductors (HTS`s) is studied in order to examine their effects in classical electromagnetic boundary value problems. It is shown that an HTS can not be simply treated as a low loss conductor and boundary conditions of HTS`s can not be considered as perfect conducting boundaries like conventional treatments. The electromagnetics of HTS are investigated in terms of complex conductivity, surface impedance with applied magnetic fields, and computational electrodynamics using the new proposed model in Ref. 1.

  12. Microsoft Word - HAB Adv #146 Tc-99.doc

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

    Performance Assessments identify Tc-99 as the primary long-term contributor to ground water contamination. What are the increased impacts to groundwater caused by elimination...

  13. 99Tc Process Monitoring System In-Lab Performance Characterization

    SciTech Connect (OSTI)

    O'Hara, Matthew J.; Niver, Cynthia M.

    2014-01-01

    Executive Summary A 99Tc Process Monitoring (Tc-Mon) System has been designed and built for deployment at the recently constructed 200 West Pump & Treat (200W P&T) Plant in the 200 West Area ZP-1 Operable Unit of the Hanford Site. The plant is operated by CH2M Hill Plateau Remediation Company (CHPRC). The Tc-Mon system was created through collaboration between Pacific Northwest National Laboratory (PNNL) and Burge Environmental, Inc. The new systems design has been optimized based on experience from an earlier field test (2011) of a prototype system at the 200W-ZP-1 Interim Pump & Treat Plant. A portion of the new 200W P&T Plant is dedicated to removal of 99Tc from contaminated groundwater in the 200 West Area. 99Tc, as the pertechnetate anion (99TcO4-), is remediated through delivery of water into two trains (Trains A and B) of three tandem extraction columns filled with Purolite A530E resin. The resin columns cannot be regenerated; therefore, once they have reached their maximum useful capacity, the columns must be disposed of as radioactive waste. The Tc-Mon systems primary duty will be to periodically sample and analyze the effluents from each of the two primary extraction columns to determine 99Tc breakthrough. The Tc-Mon system will enable the CH2M Hill Plateau Remediation Company (CHPRC) to measure primary extraction column breakthrough on demand. In this manner, CHPRC will be able to utilize each extraction column to its maximum capacity. This will significantly reduce column disposal and replacement costs over the life of the plant. The Tc-Mon system was constructed by Burge Environmental, Inc. and was delivered to PNNL in June 2013 for setup and initial hardware and software performance testing in the 325 Building. By early July, PNNL had initiated an in-laboratory performance characterization study on the system. The objective was to fully calibrate the system and then evaluate the quality of the analytical outputs 1) against a series of clean

  14. RILEM TC ISR Summer 2015 Activity Report

    SciTech Connect (OSTI)

    Le Pape, Yann

    2015-08-01

    With aging infrastructures, instances of Alkali Silica Reaction (ASR) and Delayed Ettringite Formation (DEF), broadly covered under the term Internal Swelling Reaction (ISR), are increasingly being detected. They have been observed in bridges, dams, and most recently in nuclear power plants. Concrete swelling may result in bridge partial failure, dams with structural cracks and misaligned turbine shafts, and locked slice gates. For nuclear reactors micro-cracks may cause increased gas permeability which will jeopardize the containment integrity and may decrease the residual structural resistance under accidental loading. This TC, which limits its activity to structures with known expansive concrete, seeks to address two complementary but fundamental questions: a) What is the kinetics of the reaction and b) How would it affect the integrity of the structure (serviceability and strength) and thus establish a science based prognostic to the structure owner.

  15. DOE Tour of Zero: Bellingham Power House by TC Legend Homes ...

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

    Bellingham Power House by TC Legend Homes DOE Tour of Zero: Bellingham Power House by TC Legend Homes Addthis 1 of 19 TC Legend Homes built this 2,781-square-foot home in ...

  16. DOE Tour of Zero Floorplans: Bellingham Power House by TC Legend...

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

    Bellingham Power House by TC Legend Homes DOE Tour of Zero Floorplans: Bellingham Power House by TC Legend Homes DOE Tour of Zero Floorplans: Bellingham Power House by TC Legend

  17. DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham...

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

    TC Legend Homes, Bellingham, WA DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham, WA DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham, WA Case ...

  18. DOE Tour of Zero: The Cedarwood by TC Legend Homes | Department...

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

    Cedarwood by TC Legend Homes DOE Tour of Zero: The Cedarwood by TC Legend Homes Addthis 1 of 13 Custom builder TC Legend Homes packed energy-efficiency features into this tidy...

  19. DOE Tour of Zero: The Net Zero in Seattle by TC Legend Homes...

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

    Net Zero in Seattle by TC Legend Homes DOE Tour of Zero: The Net Zero in Seattle by TC Legend Homes Addthis 1 of 15 Northwest builder TC Legend Homes has built a certified U.S. DOE...

  20. DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham...

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

    DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham Power House, ... DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham Power House, ...

  1. Introduction to Tc/I in Hanford Flowsheet

    Office of Environmental Management (EM)

    Introduction to TcI in Hanford Flowsheet Gary Smith Office of Waste Processing (EM-31) November 18, 2010 2 Rough Flowsheet Diagram Tank Farm Evaporator Pretreatment Evaporator IDF ...

  2. Bounding the Pseudogap in Cuprate High-TC Superconductors (Technical...

    Office of Scientific and Technical Information (OSTI)

    Citation Details In-Document Search Title: Bounding the Pseudogap in Cuprate High-TC Superconductors Authors: McDonald, Ross David 1 ; Shehter, Arkady 1 ; Balakirev, Fedor F. ...

  3. Solvent Extraction of Tc and Cs from Alkaline Nitrate Wastes

    SciTech Connect (OSTI)

    Moyer, Bruce A.; Bonnesen, Peter V.; Delmau, Laetitia H.; Haverlock, T J.; Sachleben, R A.; Leonard, R A.; Conner, C; Lumetta, Gregg J. ); M. Cox, M. Hidalgo, and M. Valiente

    2001-01-01

    This paper summarizes progress at three collaborating U.S. national laboratories on the extraction of the fission products 99Tc and 137Cs from alkaline high-level wastes. Efficient economical processes for Tc and Cs extraction (SRTALK and alkaline-side CSEX, respectively) have been developed, and testing has progressed through batch tests on actual wastes and continuous counter-current centrifugal-contactor tests on simulants.

  4. Solvent Extraction of Tc and Cs from Alkaline Nitrate Wastes

    SciTech Connect (OSTI)

    Bonnesen, P.V.; Conner, C.; Delmau, L.H.; Haverlock, T.J.; Leonard, R.A.; Lumetta, G.J.; Moyer, B.A.; Sachleben, R.A.

    1999-07-11

    This paper summarizes progress at three collaborating US national laboratories on the extraction of the fission products {sup 99}Tc and {sup 137}Cs from alkaline high-level wastes (HLW). Efficient, economical processes for Tc and Cs extraction (SRTALK and alkaline-side CSEX, respectively) have been developed, and testing has progressed through batch tests on actual wastes and continuous countercurrent centrifugal-contactor tests on simulants.

  5. Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity

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

    Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Wednesday, 26 April 2006 00:00 Working at the ALS, a multi-institutional collaboration led by researchers at ALS and Stanford University has identified a pseudogap phase with a nodal-antinodal dichotomy in ferromagnetic manganese oxide materials (manganites). Even though ferromagnetism and superconductivity do not exist together, the pseudogap state found in

  6. Power Systems Development Facility Gasification Test Campaign TC25

    SciTech Connect (OSTI)

    Southern Company Services

    2008-12-01

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a KBR Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This report summarizes the results of TC25, the second test campaign using a high moisture lignite coal from the Red Hills mine in Mississippi as the feedstock in the modified Transport Gasifier configuration. TC25 was conducted from July 4, 2008, through August 12, 2008. During TC25, the PSDF gasification process operated for 742 hours in air-blown gasification mode. Operation with the Mississippi lignite was significantly improved in TC25 compared to the previous test (TC22) with this fuel due to the addition of a fluid bed coal dryer. The new dryer was installed to dry coals with very high moisture contents for reliable coal feeding. The TC25 test campaign demonstrated steady operation with high carbon conversion and optimized performance of the coal handling and gasifier systems. Operation during TC25 provided the opportunity for further testing of instrumentation enhancements, hot gas filter materials, and advanced syngas cleanup technologies. The PSDF site was also made available for testing of the National Energy Technology Laboratory's fuel cell module and Media Process Technology's hydrogen selective membrane with syngas from the Transport Gasifier.

  7. Tc Reductant Chemistry and Crucible Melting Studies with Simulated Hanford Low-Activity Waste

    SciTech Connect (OSTI)

    Kim, Dong-Sang; Soderquist, Chuck Z.; Icenhower, Jonathan P.; McGrail, B PETER.; Scheele, Randall D.; McNamara, Bruce K.; Bagaasen, Larry M.; Schweiger, Michael J.; Crum, Jarrod V.; Yeager, John D.; Matyas, Josef; Darnell, Lori P.; Schaef, Herbert T.; Owen, Antionette T.; Kozelisky, Anne E.; Snow, Lanee A.; Steele, Marilyn J.

    2005-03-30

    The FY 2003 risk assessment (RA) of bulk vitrification (BV) waste packages used 0.3 wt% of the technetium (Tc) inventory as a leachable salt and found it sufficient to create a significant peak in the groundwater concentration in a 100-meter down-gradient well. Although this peak met regulatory limits, considering uncertainty in the actual Tc salt fraction, peak concentrations could exceed the maximum concentration limit (MCL) under some scenarios so reducing the leachable salt inventory is desirable. The main objective of this study was to reduce the mobile Tc species available within a BV disposal package by reducing the oxidation state of the Tc in the waste feed and/or during melting because Tc in its reduced form of Tc(IV) has a much lower volatility than Tc(VII). Reduced Tc volatility has a secondary benefit of increasing the Tc retention in glass.

  8. Tc-99 Adsorption on Selected Activated Carbons - Batch Testing Results

    SciTech Connect (OSTI)

    Mattigod, Shas V.; Wellman, Dawn M.; Golovich, Elizabeth C.; Cordova, Elsa A.; Smith, Ronald M.

    2010-12-01

    CH2M HILL Plateau Remediation Company (CHPRC) is currently developing a 200-West Area groundwater pump-and-treat system as the remedial action selected under the Comprehensive Environmental Response, Compensation, and Liability Act Record of Decision for Operable Unit (OU) 200-ZP-1. This report documents the results of treatability tests Pacific Northwest National Laboratory researchers conducted to quantify the ability of selected activated carbon products (or carbons) to adsorb technetium-99 (Tc-99) from 200-West Area groundwater. The Tc-99 adsorption performance of seven activated carbons (J177601 Calgon Fitrasorb 400, J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, J177612 Norit GAC830, J177613 Norit GAC830, and J177617 Nucon LW1230) were evaluated using water from well 299-W19-36. Four of the best performing carbons (J177606 Siemens AC1230AWC, J177609 Carbon Resources CR-1240-AW, J177611 General Carbon GC20X50, and J177613 Norit GAC830) were selected for batch isotherm testing. The batch isotherm tests on four of the selected carbons indicated that under lower nitrate concentration conditions (382 mg/L), Kd values ranged from 6,000 to 20,000 mL/g. In comparison. Under higher nitrate (750 mg/L) conditions, there was a measureable decrease in Tc-99 adsorption with Kd values ranging from 3,000 to 7,000 mL/g. The adsorption data fit both the Langmuir and the Freundlich equations. Supplemental tests were conducted using the two carbons that demonstrated the highest adsorption capacity to resolve the issue of the best fit isotherm. These tests indicated that Langmuir isotherms provided the best fit for Tc-99 adsorption under low nitrate concentration conditions. At the design basis concentration of Tc 0.865 g/L(14,700 pCi/L), the predicted Kd values from using Langmuir isotherm constants were 5,980 mL/g and 6,870 mL/g for for the two carbons. These Kd values did not meet the target Kd value of 9,000 mL/g. Tests

  9. Funda o Parque Tecnol gico da Paraiba PaqTc Incubator | Open...

    Open Energy Info (EERE)

    Funda o Parque Tecnol gico da Paraiba PaqTc Incubator Jump to: navigation, search Name: Fundao Parque Tecnolgico da Paraiba (PaqTc Incubator) Place: Brazil Sector: Services...

  10. Spin-polaron theory of high-{Tc} superconductivity: I, spin polarons and

    Office of Scientific and Technical Information (OSTI)

    high-{Tc} pairing (Conference) | SciTech Connect Spin-polaron theory of high-{Tc} superconductivity: I, spin polarons and high-{Tc} pairing Citation Details In-Document Search Title: Spin-polaron theory of high-{Tc} superconductivity: I, spin polarons and high-{Tc} pairing The concept of a spin polaron is introduced and contrasted with the more familiar ionic polaron picture. A brief review of aspects of ionic bipolaronic superconductivity is given with particular emphasis on the real-space

  11. T-692: VMware vFabric tc Server Lets Remote Users Login Using Obfuscated

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

    Passwords | Department of Energy 92: VMware vFabric tc Server Lets Remote Users Login Using Obfuscated Passwords T-692: VMware vFabric tc Server Lets Remote Users Login Using Obfuscated Passwords August 12, 2011 - 3:47pm Addthis PROBLEM: A vulnerability was reported in VMware vFabric tc Server. A remote user can login using an obfuscated version of their password. PLATFORM: Version(s): vFabric tc Server 2.0.0.RELEASE to 2.0.5.SR01, 2.1.0.RELEASE to 2.1.1.SR01 ABSTRACT: VMware vFabric tc

  12. NMR/MRI with hyperpolarized gas and high Tc SQUID

    DOE Patents [OSTI]

    Schlenga, Klaus; de Souza, Ricardo E.; Wong-Foy, Annjoe; Clarke, John; Pines, Alexander

    2000-01-01

    A method and apparatus for the detection of nuclear magnetic resonance (NMR) signals and production of magnetic resonance imaging (MRI) from samples combines the use of hyperpolarized inert gases to enhance the NMR signals from target nuclei in a sample and a high critical temperature (Tc) superconducting quantum interference device (SQUID) to detect the NMR signals. The system operates in static magnetic fields of 3 mT or less (down to 0.1 mT), and at temperatures from liquid nitrogen (77K) to room temperature. Sample size is limited only by the size of the magnetic field coils and not by the detector. The detector is a high Tc SQUID magnetometer designed so that the SQUID detector can be very close to the sample, which can be at room temperature.

  13. Power Systems Development Facility Gasification Test Campaign TC24

    SciTech Connect (OSTI)

    Southern Company Services

    2008-03-30

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a KBR Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This report summarizes the results of TC24, the first test campaign using a bituminous coal as the feedstock in the modified Transport Gasifier configuration. TC24 was conducted from February 16, 2008, through March 19, 2008. The PSDF gasification process operated for about 230 hours in air-blown gasification mode with about 225 tons of Utah bituminous coal feed. Operational challenges in gasifier operation were related to particle agglomeration, a large percentage of oversize coal particles, low overall gasifier solids collection efficiency, and refractory degradation in the gasifier solids collection unit. The carbon conversion and syngas heating values varied widely, with low values obtained during periods of low gasifier operating temperature. Despite the operating difficulties, several periods of steady state operation were achieved, which provided useful data for future testing. TC24 operation afforded the opportunity for testing of various types of technologies, including dry coal feeding with a developmental feeder, the Pressure Decoupled Advanced Coal (PDAC) feeder; evaluating a new hot gas filter element media configuration; and enhancing syngas cleanup with water-gas shift catalysts. During TC24, the PSDF site was also made available for testing of the National Energy Technology Laboratory's fuel cell module and Media Process Technology's hydrogen selective membrane.

  14. Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity

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

    Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Working at the ALS, a multi-institutional collaboration led by researchers at ALS and Stanford University has identified a pseudogap phase with a nodal-antinodal dichotomy in ferromagnetic manganese oxide materials (manganites). Even though ferromagnetism and superconductivity do not exist together, the pseudogap state found in these manganites is remarkably similar to that found in high-temperature superconducting copper

  15. Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity

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

    Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Working at the ALS, a multi-institutional collaboration led by researchers at ALS and Stanford University has identified a pseudogap phase with a nodal-antinodal dichotomy in ferromagnetic manganese oxide materials (manganites). Even though ferromagnetism and superconductivity do not exist together, the pseudogap state found in these manganites is remarkably similar to that found in high-temperature superconducting copper

  16. Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity

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

    Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity Print Working at the ALS, a multi-institutional collaboration led by researchers at ALS and Stanford University has identified a pseudogap phase with a nodal-antinodal dichotomy in ferromagnetic manganese oxide materials (manganites). Even though ferromagnetism and superconductivity do not exist together, the pseudogap state found in these manganites is remarkably similar to that found in high-temperature superconducting copper

  17. Bridging the Gaps of High-Tc Superconductor

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

    Bridging the Gaps of High-Tc Superconductor Since the discovery of high-temperature superconductor by Bednorz and Müller in 1986, this field has become one of the most important research topics in solid state physics. In the past 20 years many unconventional properties have been discovered in this new class of materials. These have challenged our conventional wisdom and driven the development of many novel theories. Among these discoveries, the most mysterious is probably the pseudogap

  18. Power Systems Development Facility Gasification Test Campaing TC18

    SciTech Connect (OSTI)

    Southern Company Services

    2005-08-31

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF) located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a KBR Transport Gasifier, a hot gas particulate control device (PCD), advanced syngas cleanup systems, and high pressure solids handling systems. This report details Test Campaign TC18 of the PSDF gasification process. Test campaign TC18 began on June 23, 2005, and ended on August 22, 2005, with the gasifier train accumulating 1,342 hours of operation using Powder River Basin (PRB) subbituminous coal. Some of the testing conducted included commissioning of a new recycle syngas compressor for gasifier aeration, evaluation of PCD filter elements and failsafes, testing of gas cleanup technologies, and further evaluation of solids handling equipment. At the conclusion of TC18, the PSDF gasification process had been operated for more than 7,750 hours.

  19. Tc and Re Behavior in Borosilicate Waste Glass Vapor Hydration Tests

    SciTech Connect (OSTI)

    McKeown, David A.; Buechele, Andrew C.; Pegg, Ian L.; Lukens, Wayne W.; Shuh, David K.

    2007-07-01

    Technetium (Tc), found in some nuclear wastes, is of particular concern with regard to long-term storage, because of its long-lived radioactivity and high mobility in the environment. Tc and rhenium (Re), commonly used as a non-radioactive surrogate for Tc, were studied to assess their behavior in borosilicate glass under hydrothermal conditions in the Vapor Hydration Test (VHT). X-ray absorption spectroscopy (XAS) and scanning electron microscopy (SEM) measurements were made on the original Tc- and Re-containing glasses and their corresponding VHT samples, and show different behavior for Tc and Re under VHT conditions. XAS indicates that, despite starting with different Tc(IV) and Tc(VII) distributions in each glass, the VHT samples have 100% Tc(IV)O{sub 6} environments. SEM shows complete alteration of the original glass, Tc enrichment near the sample surface, and Tc depletion in the center. Perrhenate (Re(VII)O{sub 4}{sup -}) is dominant in both Re-containing samples before and after the VHT, where Re is depleted near the VHT sample surface and more concentrated toward the center. (authors)

  20. Universal Charge Order in the High-Tc Superconductors | Stanford

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

    Synchrotron Radiation Lightsource Universal Charge Order in the High-Tc Superconductors Wednesday, May 4, 2016 - 3:00pm SLAC, Redtail Hawk Conference Room 108A Speaker: Eduardo H. da Silva Neto - UBC Eduardo H. da Silva Neto was born in Recife, Brazil. He obtained his B.A. in Physics and Mathematics (2008) from Amherst College, and his Ph. D. (2013) in Physics from Princeton University. Since 2013 he has been a Max-Planck-UBC postdoctoral research fellow at the Quantum Matter Institute at

  1. Recap and Conclusions to Tc/I in Hanford Flowsheet Presentations

    Office of Environmental Management (EM)

    Recap & Conclusions to TcI in Hanford Flowsheet Presentations Gary Smith Office of Waste Processing (EM-31) November 18, 2010 2 Rough Flowsheet Diagram Tank Farm Evaporator ...

  2. 99Tc(VII) Retardation, Reduction, and Redox Rate Scaling in Naturally...

    Office of Scientific and Technical Information (OSTI)

    Reduction, and Redox Rate Scaling in Naturally Reduced Sediments Citation Details In-Document Search Title: 99Tc(VII) Retardation, Reduction, and Redox Rate Scaling in ...

  3. Spin-polaron theory of high-{Tc} superconductivity: I, spin polarons...

    Office of Scientific and Technical Information (OSTI)

    Subject: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; HIGH-TC SUPERCONDUCTORS; PAIRING ENERGY; POLARONS; SPIN; SPIN FLIP; COPPER OXIDES 665411; BASIC ...

  4. Power Systems Development Facility Gasification Test Campaign TC22

    SciTech Connect (OSTI)

    Southern Company Services

    2008-11-01

    In support of technology development to utilize coal for efficient, affordable, and environmentally clean power generation, the Power Systems Development Facility (PSDF), located in Wilsonville, Alabama, routinely demonstrates gasification technologies using various types of coals. The PSDF is an engineering scale demonstration of key features of advanced coal-fired power systems, including a KBR Transport Gasifier, a hot gas particulate control device, advanced syngas cleanup systems, and high-pressure solids handling systems. This report summarizes the results of TC22, the first test campaign using a high moisture lignite from Mississippi as the feedstock in the modified Transport Gasifier configuration. TC22 was conducted from March 24 to April 17, 2007. The gasification process was operated for 543 hours, increasing the total gasification operation at the PSDF to over 10,000 hours. The PSDF gasification process was operated in air-blown mode with a total of about 1,080 tons of coal. Coal feeder operation was challenging due to the high as-received moisture content of the lignite, but adjustments to the feeder operating parameters reduced the frequency of coal feeder trips. Gasifier operation was stable, and carbon conversions as high as 98.9 percent were demonstrated. Operation of the PCD and other support equipment such as the recycle gas compressor and ash removal systems operated reliably.

  5. Synthesis, structure elucidation and redox properties of 99Tc complexes of lacunary Wells Dawson polyoxometalates: insights into molecular 99Tc - metal oxide interactions

    SciTech Connect (OSTI)

    McGregor, Donna; Burton-Pye, Benjamin P.; Howell, Robertha C.; Mbomekalle, Israel M.; Lukens Jr, Wayne W.; Bian, Fang; Mausolf, Edward; Poineau, Frederic; Czerwinski, Kenneth R; Francesconi, Lynn C.

    2011-01-10

    The isotope 99Tc (beta max: 250 keV, half-life: 2 x 105 year) is an abundant product of uranium-235 fission in nuclear reactors and is present throughout the radioactive waste stored in underground tanks at Hanford and Savannah River. Understanding and controlling the extensive redox chemistry of 99Tc is important to identify tunable strategies to separate 99Tc from spent fuel and from waste tanks and once separated, to identify and develop an appropriately stable waste-form for 99Tc. Polyoxometalates (POMs), nanometer sized models for metal oxide solid-state materials, are used in this study to provide a molecular level understanding of the speciation and redox chemistry of incorporated 99Tc. In this study, 99Tc complexes of the (alpha 2-P2W17O61)10- and (alpha 1-P2W17O61)10- isomers were prepared. Ethylene glycol was used as a"transfer ligand" to minimize the formation of TcO2 cdot xH2O. The solution structures, formulations, and purity of TcVO(alpha 1/alpha 2-P2W17O61)7- were determined by multinuclear NMR. X-ray Absorption Spectroscopy of the complexes are in agreement with the formulation and structures determined from 31P and 183W NMR. Preliminary electrochemistry results are consistent with the EXAFS results, showing a facile reduction of the TcVO(alpha 1-P2W17O61)7- species compared to the TcVO(alpha 2-P2W17O61)7- analog. The alpha1- defect is unique in that a basic oxygen atom is positioned toward the alpha1- site and the TcVO center appears to form a dative metal-metal bond with a framework W site. These attributes may lead to the assistance of protonation events that facilitate reduction. Electrochemistry comparison shows that the ReV analogs are about 200 mV more difficult to reduce in accordance with periodic trends.

  6. In-Situ Data for Microphysical Retrievals: TC4, 2007

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Mace, Gerald

    2016-04-01

    This data set is derived from measurements collected in situ by the NASA DC8 during the Tropical Cloud Climate Composition Coupling Experiment (TC4) that was conducted during July and August, 2007 (Toon et al., 2010). During this experiment the DC8 was based in San Jose, Costa Rica and sampled clouds in the maritime region of the Eastern Pacific and adjoining continental areas. The primary objective of the DC8 during this deployment was to sample ice clouds associated with convective activity. While the vast majority of the data are from ice-phase clouds that have recent association with convection, other types of clouds such as boundary layer clouds and active convection were also sampled and are represented in this data set. The derived data set, as compiled in this delivery, includes approximately 15,000 5-second averaged measurements collected by the NASA DC8.

  7. Oxidative Dissolution Potential of Biogenic and Abiogenic TcO2 in Subsurface Sediments

    SciTech Connect (OSTI)

    Fredrickson, Jim K.; Zachara, John M.; Plymale, Andrew E.; Heald, Steve M.; McKinley, James P.; Kennedy, David W.; Liu, Chongxuan; Nachimuthu, Ponnusamy

    2009-04-15

    Technetium-99 (Tc) is an important fission product contaminant associated with sites of nuclear fuels reprocessing and geologic nuclear waste disposal. Exhibiting an intermediate redox potential, Tc is highly mobile in its anionic, oxidized state [Tc(VII)O4-]; and less mobile as a poorly soluble oxyhydroxide precipitate [Tc(IV)O2•nH2O] in its reduced state. Here we investigate the potential for oxidation of Tc(IV) that was heterogeneously reduced by reaction with biogenic Fe(II) in two sediments differing in mineralogy and aggregation state (FRC, RG). Both sediments contained Fe(III) and Mn(III/IV) as redox active phases, but FRC also contained mass-dominant Fe-phyllosilicates of different types. Biogenic Tc(IV)O2•nH2O was oxidized in anoxic, but unreduced RG and FRC sediments through redox interaction with Mn(III/IV) oxides. Bioreduction by Shewanella putrefaciens CN32 dissolved Mn(III/IV) oxides and generated biogenic Fe(II) that was reactive with Tc(VII) in heat-killed, bioreduced sediment. Biogenic Fe(II) in the FRC exceeded that in RG by a factor of two. More rapid reduction rates were observed in the RG that had lower biogenic Fe(II), and less particle aggregation. EXAFS measurements indicated that the primary reduction product was a TcO2-like phase in both sediments. Redox product Tc(IV) oxidized rapidly and completely in RG when contacted with air. Oxidation, in contrast, was slow and incomplete in the FRC, in spite of similar molecular speciation to RG. X-ray microprobe, electron microprobe, x-ray absorption spectroscopy, and micro x-ray diffraction were applied to the whole sediment and isolated Tc-contained particles. These analyses revealed that non-oxidizable Tc(IV) in the FRC existed as complexes with octahedral Fe(III) within intra-grain domains of 50-100 µm-sized, Fe-containing micas presumptively identified as celadonite. The markedly slower oxidation rates in FRC as compared to RG were attributed to mass-transfer-limited migration of O2 into

  8. Oxidative dissolution potential of biogenic and abiogenic TcO{sub 2} in subsurface sediments.

    SciTech Connect (OSTI)

    Fredrickson, J. K.; Zachara, J. M.; Plymale, A. E.; Heald, S. M.; McKinley, J. P.; Kennedy, D. W.; Liu, C.; Nachimuthu, P.

    2009-04-01

    Technetium-99 (Tc) is an important fission product contaminant associated with sites of nuclear fuels reprocessing and geologic nuclear waste disposal. Tc is highly mobile in its most oxidized state [Tc(VII)O{sub 4}{sup -}] and less mobile in the reduced form [Tc(IV)O{sub 2} {center_dot} nH{sub 2}O]. Here we investigate the potential for oxidation of Tc(IV) that was heterogeneously reduced by reaction with biogenic Fe(II) in two sediments differing in mineralogy and aggregation state; unconsolidated Pliocene-age fluvial sediment from the upper Ringold (RG) Formation at the Hanford Site and a clay-rich saprolite from the Field Research Center (FRC) background site on the Oak Ridge Site. Both sediments contained Fe(III) and Mn(III/IV) as redox active phases, but FRC also contained mass-dominant Fe-phyllosilicates of different types. Shewanella putrefaciens CN32 reduced Mn(III/IV) oxides and generated Fe(II) that was reactive with Tc(VII) in heat-killed, bioreduced sediment. After bioreduction and heat-killing, biogenic Fe(II) in the FRC exceeded that in RG by a factor of two. More rapid reduction rates were observed in the RG that had lower biogenic Fe(II), and less particle aggregation. EXAFS measurements indicated that the primary reduction product was a TcO{sub 2}-like phase in both sediments. The biogenic redox product Tc(IV) oxidized rapidly and completely in RG when contacted with air. Oxidation, in contrast, was slow and incomplete in the FRC, in spite of similar molecular scale speciation of Tc compared to RG. X-ray microprobe, electron microprobe, X-ray absorption spectroscopy, and micro X-ray diffraction were applied to the whole sediment and isolated Tc-containing particles. These analyses revealed that non-oxidizable Tc(IV) in the FRC existed as complexes with octahedral Fe(III) within intra-grain domains of 50-100 {micro}m-sized, Fe-containing micas presumptively identified as celadonite. The markedly slower oxidation rates in FRC as compared to RG were

  9. INFLUENCE OF NATURAL AND SYNTHETIC ORGANIC LIGANDS ON THE STABILITY AND MOBILITY OF REDUCED TC(IV)

    SciTech Connect (OSTI)

    Nathalie A. Wall; Baohua Gu

    2012-12-20

    The primary objectives were (1) to quantify the interactions of organic ligands with Tc(IV) through the generation of thermodynamic (complexation) and kinetic parameters needed to assess and predict the mobility of reduced Tc(IV) at DOE contaminated sites; and (2) to determine the impact of organic ligands on the mobility and fate of reduced Tc(IV) under field geochemical conditions.

  10. ARM - PI Product - In-Situ Data for Microphysical Retrievals: TC4, 2007

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

    ProductsIn-Situ Data for Microphysical Retrievals: TC4, 2007 Citation DOI: 10.5439/1244832 [ What is this? ] ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send PI Product : In-Situ Data for Microphysical Retrievals: TC4, 2007 [ ARM research ] This data set is derived from measurements collected in situ by the NASA DC8 during the Tropical Cloud Climate Composition Coupling Experiment (TC4) that was conducted during July

  11. DOE Tour of Zero: Bellingham Power House by TC Legend Homes | Department of

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

    Energy Bellingham Power House by TC Legend Homes DOE Tour of Zero: Bellingham Power House by TC Legend Homes 1 of 19 TC Legend Homes built this 2,781-square-foot home in Bellingham, Washington, to the performance criteria of the U.S. Department of Energy Zero Energy Ready Home (ZERH) program. 2 of 19 A greenhouse off the kitchen provides a thermal transition zone into the home, minimizing heat losses during the winter. The solar hot water heating panels are visible on the porch roof. 3 of 19

  12. DOE Zero Energy Ready Home Case Study: TC Legend, Seattle, WA...

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

    Legend, Seattle, WA, Custom Home DOE Zero Energy Ready Home Case Study: TC Legend, Seattle, WA, Custom Home Case study of a DOE Zero Energy Ready Home in Seattle, WA, that scored ...

  13. V-183: Cisco TelePresence TC and TE Bugs Let Remote Users Deny...

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

    Remote Users Deny Service and Remote Adjacent Authenticated Users Gain Root Shell Access V-183: Cisco TelePresence TC and TE Bugs Let Remote Users Deny Service and Remote Adjacent...

  14. In-Situ Data for Microphysical Retrievals: TC4, 2007 (Dataset...

    Office of Scientific and Technical Information (OSTI)

    This data set is derived from measurements collected in situ by the NASA DC8 during the Tropical Cloud Climate Composition Coupling Experiment (TC4) that was conducted during July ...

  15. Response of High-Tc Superconductor Metamaterials to High Intensity THz

    Office of Scientific and Technical Information (OSTI)

    Radiation (Conference) | SciTech Connect Response of High-Tc Superconductor Metamaterials to High Intensity THz Radiation Citation Details In-Document Search Title: Response of High-Tc Superconductor Metamaterials to High Intensity THz Radiation Authors: Grady, Nathaniel [1] ; Perkins Jr., Bradford G. [2] ; Hwang, Harold Y. [2] ; Brandt, Nate [2] ; Torchinsky, Darius [2] ; Singh, Ranjan [1] ; Yan, Li [3] ; Jia, Quanxi [1] ; Trugman, Stuart A. [1] ; Taylor, Antoinette J. [1] ; Nelson, Keith

  16. PV Standards: What IEC TC82 is Doing for You | Department of Energy

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

    Standards: What IEC TC82 is Doing for You PV Standards: What IEC TC82 is Doing for You Presented at the PV Module Reliability Workshop, February 26 - 27 2013, Golden, Colorado pvmrw13_ps3_sunset_kelly.pdf (74.81 KB) More Documents & Publications QA TG5 UV, temperature and humidity Test Procedure for UV Weathering Resistance of Backsheet Literature Review of the Effects of UV Exposure on PV Modules

  17. Investigation of Tc Migration Mechanism During Bulk Vitrification Process Using Re Surrogate

    SciTech Connect (OSTI)

    Kim, Dong-Sang; Bagaasen, Larry M.; Crum, Jarrod V.; Fluegel, Alex; Gallegos, Autumn B.; Martinez, Baudelio; Matyas, Josef; Meyer, Perry A.; Paulsen, Dan; Riley, Brian J.; Schweiger, Michael J.; Stewart, Charles W.; Swoboda, Robert G.; Yeager, John D.

    2006-12-04

    As a part of Bulk vitrification (BV) performance enhancement tasks, Laboratory scoping tests were performed in FY 2004-2005 to explore possible ways to reduce the amount of soluble Tc in the BV waste package. Theses scoping tests helped identify which mechanisms play an important role in the migration of Tc in the BV process (Hrma et al. 2005 and Kim et al. 2005). Based on the results from these scoping tests, additional tests were identified that will improve the understanding of Tc migration and to clearly identify the dominant mechanisms. The additional activities identified from previous studies were evaluated and prioritized for planning for Tasks 29 and 30 conducted in FY2006. Task 29 focused on the improved understanding of Tc migration mechanisms, and Task 30 focused on identifying the potential process changes that might reduce Tc/Re migration into the castable refractory block (CRB). This report summarizes the results from the laboratory- and crucible-scale tests in the lab for improved Tc migration mechanism understanding utilizing Re as a surrogate performed in Task 29.

  18. Near-yrast, medium-spin structure of the {sup 109}Tc nucleus

    SciTech Connect (OSTI)

    Urban, W.; Pinston, J. A.; Smith, A. G.; Ahmad, I.

    2010-12-15

    Excited levels in the {sup 109}Tc nucleus, populated in the spontaneous fission of {sup 248}Cm, have been studied using the EUROGAM2 array. In {sup 109}Tc we have found a new band corresponding to the {pi}5/2{sup -}[303] configuration and a three-quasiparticle band with I{sup {pi}}=(15/2{sup -}) band-head level at 1749.5 keV. The structure of the 1749.5-keV level probably involves the {l_brace}{pi}5/2{sup +}[422]{nu}(5/2{sup -}[532],5/2{sup +}[413]){r_brace}{sub 15/2}{sup -} prolate configuration. The quasiparticle-rotor model calculations performed in this work show that the odd-proton configurations observed in {sup 107}Tc and {sup 109}Tc are consistent with the scheme of proton excitations in a prolate triaxial potential. Significant differences between the degree of triaxiality observed for positive- and negative-parity excitations may be due to blocking of the triaxial shape by the odd proton populating negative-parity orbitals. The properties of the new 494.5-, 1440.7-, and 1748.8-keV levels found in {sup 109}Tc may indicate a change toward an oblate shape in this nucleus.

  19. DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham, WA |

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

    Department of Energy Bellingham, WA DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham, WA DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham, WA Case study of a DOE Zero Energy Ready home in Bellingham, WA, that achieves HERS 43 without PV or HERS 13 with 3.2 kW of PV. The 1,055-ft2 two-story production home has 6-in. SIP walls, a 10-in. SIP roof, and ICF foundation walls with R-20 high-density rigid EPS foam under the slab. A single ductless heat pump heats

  20. Migrating data from TcSE to DOORS : an evaluation of the T-Plan Integrator software application.

    SciTech Connect (OSTI)

    Post, Debra S.; Manzanares, David A.; Taylor, Jeffrey L.

    2011-02-01

    This report describes our evaluation of the T-Plan Integrator software application as it was used to transfer a real data set from the Teamcenter for Systems Engineering (TcSE) software application to the DOORS software application. The T-Plan Integrator was evaluated to determine if it would meet the needs of Sandia National Laboratories to migrate our existing data sets from TcSE to DOORS. This report presents the struggles of migrating data and focuses on how the Integrator can be used to map a data set and its data architecture from TcSE to DOORS. Finally, this report describes how the bulk of the migration can take place using the Integrator; however, about 20-30% of the data would need to be transferred from TcSE to DOORS manually. This report does not evaluate the transfer of data from DOORS to TcSE.

  1. Liquid scintillation counting methodology for 99Tc analysis. A remedy for radiopharmaceutical waste

    SciTech Connect (OSTI)

    Khan, Mumtaz; Um, Wooyong

    2015-08-13

    This paper presents a new approach for liquid scintillation counting (LSC) analysis of single-radionuclide samples containing appreciable organic or inorganic quench. This work offers better analytical results than existing LSC methods for technetium-99 (99gTc) analysis with significant savings in analysis cost and time. The method was developed to quantify 99gTc in environmental liquid and urine samples using LSC. Method efficiency was measured in the presence of 1.9 to 11,900 ppm total dissolved solids. The quench curve was proved to be effective in the case of spiked 99gTc activity calculation for deionized water, tap water, groundwater, seawater, and urine samples. Counting efficiency was found to be 91.66% for Ultima Gold LLT (ULG-LLT) and Ultima Gold (ULG). Relative error in spiked 99gTc samples was ±3.98% in ULG and ULG-LLT cocktails. Minimum detectable activity was determined to be 25.3 mBq and 22.7 mBq for ULG-LLT and ULG cocktails, respectively. A pre-concentration factor of 1000 was achieved at 100°C for 100% chemical recovery.

  2. Kit for the selective labeling of red blood cells in whole blood with [sup 99]Tc

    DOE Patents [OSTI]

    Srivastava, S.C.; Babich, J.W.; Straub, R.; Richards, P.

    1992-05-26

    Disclosed herein are a method and kit for the preparation of [sup 99m]Tc labeled red blood cells using whole blood in a closed sterile system containing stannous tin in a form such that it will enter the red blood cells and be available therein for reduction of technetium. No Drawings

  3. Kit for the selective labeling of red blood cells in whole blood with .sup.9 TC

    DOE Patents [OSTI]

    Srivastava, Suresh C.; Babich, John W.; Straub, Rita; Richards, Powell

    1992-01-01

    Disclosed herein are a method and kit for the preparation of .sup.99m Tc labeled red blood cells using whole blood in a closed sterile system containing stannous tin in a form such that it will enter the red blood cells and be available therein for reduction of technetium.

  4. New method for the selective labeling of erythrocytes in whole blood with Tc-99m

    DOE Patents [OSTI]

    Srivastava, S.C.; Babich, J.W.; Straub, R.; Richards, P.

    1984-01-27

    Method and kit are described for the preparation of /sup 99m/Tc labeled red blood cells using whole blood in a closed sterile system containing stannous tin in a form such that it will enter the red blood cells and be available therein for the reduction of technetium.

  5. Luminescence-Based Spectroelectrochemical Sensor for [Tc(dmpe)3]2+/+ (dmpe = 1,2-bis(dimethylphosphino)ethane) within a Charge-Selective Polymer Film

    SciTech Connect (OSTI)

    Chatterjee, Sayandev; Del Negro, Andrew S.; Edwards, Matthew K.; Bryan, Samuel A.; Kaval, Necati; Pantelic, Nebojsa; Morris, Laura K.; Heineman, W. R.; Seliskar, Carl J.

    2011-03-01

    A spectroelectrochemical sensor consisting of an indium tin oxide (ITO) optically transparent electrode (OTE) coated with a thin film of sulfonated polystyrene-blockpoly(ethylene-ran-butylene)-block-polystyrene (SSEBS) was developed for [Tc(dmpe)3]+.. [Tc(dmpe)3]+ preconcentrated by ion-exchange into the SSEBS film after 20 min exposure to aqueous [Tc(dmpe)3]+ solution, resulting in a 14-fold increase in cathodic peak current compared to a bare OTE. Colorless [Tc(dmpe)3]+ was reversibly oxidized to colored [Tc(dmpe)3]2+ by cyclic voltammetry. Detection of [Tc(dmpe)3]2+ was accomplished by electrochemically cycling the complex between non-emissive [Tc(dmpe)3]+ and emissive [Tc(dmpe)3]2+ and monitoring the modulated emission (?exc = 532 nm; ?em = 660 nm). The sensor gave a linear response over the range of 0.16 to 340.0 M.

  6. DOE Zero Energy Ready Home Case Study 2013: TC Legend, Seattle, WA

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

    TC Legend Homes Seattle, WA BUILDING TECHNOLOGIES OFFICE The U.S. Department of Energy invites home builders across the country to meet the extraordinary levels of excellence and quality specifi ed in DOE's Zero Energy Ready Home program (formerly known as Challenge Home). Every DOE Zero Energy Ready Home starts with ENERGY STAR for Homes Version 3 for an energy-effi cient home built on a solid foundation of building science research. Advanced technologies are designed in to give you superior

  7. Novel Approach to Prepare {sup 99m}Tc-Based Multivalent RGD Peptides

    SciTech Connect (OSTI)

    Shuang Liu

    2012-10-24

    This project presents a novel approach to prepare the {sup 99m}Tc-bridged multivalent RGD (arginine-glycine-aspartate) peptides. This project will focus on fundamentals of {sup 99m}Tc radiochemistry. The main objective of this project is to demonstrate the proof-of-principle for the proposed radiotracers. Once a kit formulation is developed for preparation of the {sup 99m}Tc-bridged multivalent RGD peptides, various tumor-bearing animal models will be used to evaluate their potential for SPECT (single photon-emission computed tomography) imaging of cancer. We have demonstrated that (1) multimerization of cyclic RGD peptides enhances the integrin {alpha}{sub v}{beta}{sub 3} bonding affinity and radiotracer tumor uptake; (2) addition of G{sub 3} or PEG{sub 4} linkers makes it possible for two RGD motifs in 3P-RGD{sub 2} and 3G-RGD{sub 2} to achieve simultaneous integrin {alpha}{sub v}{beta}{sub 3} binding; and (3) multimers are actually bivalent (not multivalent), the presence of extra RGD motifs can enhance the tumor retention time of the radiotracer.

  8. Method for the production of .sup.99m Tc compositions from .sup.99 Mo-containing materials

    DOE Patents [OSTI]

    Bennett, Ralph G.; Christian, Jerry D.; Grover, S. Blaine; Petti, David A.; Terry, William K.; Yoon, Woo Y.

    1998-01-01

    An improved method for producing .sup.99m Tc compositions from .sup.99 Mo compounds. .sup.100 Mo metal or .sup.100 MoO.sub.3 is irradiated with photons in a particle (electron) accelerator to ultimately produce .sup.99 MoO.sub.3. This composition is then heated in a reaction chamber to form a pool of molten .sup.99 MoO.sub.3 with an optimum depth of 0.5-5 mm. A gaseous mixture thereafter evolves from the molten .sup.99 MoO.sub.3 which contains vaporized .sup.99 MoO.sub.3, vaporized .sup.99m TcO.sub.3, and vaporized .sup.99m TcO.sub.2. This mixture is then combined with an oxidizing gas (O.sub.2(g)) to generate a gaseous stream containing vaporized .sup.99m Tc.sub.2 O.sub.7 and vaporized .sup.99 MoO.sub.3. Next, the gaseous stream is cooled in a primary condensation stage in the reaction chamber to remove vaporized .sup.99 MoO.sub.3. Cooling is undertaken at a specially-controlled rate to achieve maximum separation efficiency. The gaseous stream is then cooled in a sequential secondary condensation stage to convert vaporized .sup.99m Tc.sub.2 O.sub.7 into a condensed .sup.99m Tc-containing reaction product which is collected.

  9. Method for the production of {sup 99m}Tc compositions from {sup 99}Mo-containing materials

    DOE Patents [OSTI]

    Bennett, R.G.; Christian, J.D.; Grover, S.B.; Petti, D.A.; Terry, W.K.; Yoon, W.Y.

    1998-09-01

    An improved method is described for producing {sup 99m}Tc compositions from {sup 99}Mo compounds. {sup 100}Mo metal or {sup 100}MoO{sub 3} is irradiated with photons in a particle (electron) accelerator to ultimately produce {sup 99}MoO{sub 3}. This composition is then heated in a reaction chamber to form a pool of molten {sup 99}MoO{sub 3} with an optimum depth of 0.5--5 mm. A gaseous mixture thereafter evolves from the molten {sup 99}MoO{sub 3} which contains vaporized {sup 99}MoO{sub 3}, vaporized {sup 99m}TcO{sub 3}, and vaporized {sup 99m}TcO{sub 2}. This mixture is then combined with an oxidizing gas (O{sub 2(g)}) to generate a gaseous stream containing vaporized {sup 99m}Tc{sub 2}O{sub 7} and vaporized {sup 99}MoO{sub 3}. Next, the gaseous stream is cooled in a primary condensation stage in the reaction chamber to remove vaporized {sup 99}MoO{sub 3}. Cooling is undertaken at a specially-controlled rate to achieve maximum separation efficiency. The gaseous stream is then cooled in a sequential secondary condensation stage to convert vaporized {sup 99m}Tc{sub 2}O{sub 7} into a condensed {sup 99m}Tc-containing reaction product which is collected. 1 fig.

  10. Optimizing Cr(VI) and Tc(VII) remediation through nano-scale biomineral engineering

    SciTech Connect (OSTI)

    Cutting, R. S.; Coker, V. S.; Telling, N. D.; Kimber, R. L.; Pearce, C. I.; Ellis, B.; Lawson, R; van der Laan, G.; Pattrick, R.A.D.; Vaughan, D.J.; Arenholz, E.; Lloyd, J. R.

    2009-09-09

    To optimize the production of biomagnetite for the bioremediation of metal oxyanion contaminated waters, the reduction of aqueous Cr(VI) to Cr(III) by two biogenic magnetites and a synthetic magnetite was evaluated under batch and continuous flow conditions. Results indicate that nano-scale biogenic magnetite produced by incubating synthetic schwertmannite powder in cell suspensions of Geobacter sulfurreducens is more efficient at reducing Cr(VI) than either biogenic nano-magnetite produced from a suspension of ferrihydrite 'gel' or synthetic nano-scale Fe{sub 3}O{sub 4} powder. Although X-ray Photoelectron Spectroscopy (XPS) measurements obtained from post-exposure magnetite samples reveal that both Cr(III) and Cr(VI) are associated with nanoparticle surfaces, X-ray Magnetic Circular Dichroism (XMCD) studies indicate that some Cr(III) has replaced octahedrally coordinated Fe in the lattice of the magnetite. Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) measurements of total aqueous Cr in the associated solution phase indicated that, although the majority of Cr(III) was incorporated within or adsorbed to the magnetite samples, a proportion ({approx}10-15 %) was released back into solution. Studies of Tc(VII) uptake by magnetites produced via the different synthesis routes also revealed significant differences between them as regards effectiveness for remediation. In addition, column studies using a {gamma}-camera to obtain real time images of a {sup 99m}Tc(VII) radiotracer were performed to visualize directly the relative performances of the magnetite sorbents against ultra-trace concentrations of metal oxyanion contaminants. Again, the magnetite produced from schwertmannite proved capable of retaining more ({approx}20%) {sup 99m}Tc(VII) than the magnetite produced from ferrihydrite, confirming that biomagnetite production for efficient environmental remediation can be fine-tuned through careful selection of the initial Fe(III) mineral substrate

  11. Kit for the rapid preparation of .sup.99m Tc red blood cells

    DOE Patents [OSTI]

    Richards, Powell; Smith, Terry D.

    1976-01-01

    A method and sample kit for the preparation of .sup.99m Tc-labeled red blood cells in a closed, sterile system. A partially evacuated tube, containing a freeze-dried stannous citrate formulation with heparin as an anticoagulant, allows whole blood to be automatically drawn from the patient. The radioisotope is added at the end of the labeling sequence to minimize operator exposure. Consistent 97% yields in 20 minutes are obtained with small blood samples. Freeze-dried kits have remained stable after five months.

  12. Soy-Based, Water-Cooled, TC W-III Two Cycle Engine Oil

    SciTech Connect (OSTI)

    Scharf, Curtis R.; Miller, Mark E.

    2003-08-30

    The objective of this project was to achieve technical approval and commercial launch for a biodegradable soy oil-based, environmentally safe, TC W-III performance, water-cooled, two cycle engine oil. To do so would: (1) develop a new use for RBD soybean oil; (2) increase soybean utilization in North America in the range of 500 K-3.0 MM bushels; and (3) open up supply opportunities of 1.5-5.0 MM bushels worldwide. These goals have been successfully obtained.

  13. {sup 97}Tc produced by the ({sup 3}He,{ital pn}{gamma}) reaction

    SciTech Connect (OSTI)

    Aslan, H.; Crowe, B.; Dague, T.; Savage, D.G.; Zeghib, S.; Rickey, F.A.; Simms, P.C.

    1996-08-01

    The nuclear structure of {sup 97}Tc was studied using the {sup 96}Mo({sup 3}He,{ital pn}{gamma}) reaction, which has populated most states in the nucleus below 2 MeV excitation energy. The proton exit channel was isolated from competing reaction channels by operating {gamma}-ray detectors in coincidence with a large-solid-angle proton detector. The experiments included {gamma}-ray excitation functions, {gamma}-ray angular distributions, and {gamma}-{gamma} coincidences. The results were interpreted using a particle-rotor model. {copyright} {ital 1996 The American Physical Society.}

  14. {sup 101}Tc produced by the ({sup 3}He,pn{gamma}) reaction

    SciTech Connect (OSTI)

    Savage, D.G.; Aslan, H.; Crowe, B.; Dague, T.; Zeghib, S.; Rickey, F.A.; Simms, P.C.

    1997-01-01

    The nuclear structure of {sup 101}Tc was studied using the {sup 100}Mo({sup 3}He,pn{gamma}) reaction, which has populated most states in the nucleus below 2 MeV excitation energy. The proton exit channel was isolated from competing reaction channels by operating {gamma}-ray detectors in coincidence with a large-solid-angle proton detector. The experiments included {gamma}-ray excitation functions, {gamma}-ray angular distributions, and {gamma}-{gamma} coincidences. The results were interpreted using a particle-rotor model. {copyright} {ital 1997} {ital The American Physical Society}

  15. Conceptual design of a new homogeneous reactor for medical radioisotope Mo-99/Tc-99m production

    SciTech Connect (OSTI)

    Liem, Peng Hong; Tran, Hoai Nam; Sembiring, Tagor Malem; Arbie, Bakri

    2014-09-30

    To partly solve the global and regional shortages of Mo-99 supply, a conceptual design of a nitrate-fuel-solution based homogeneous reactor dedicated for Mo-99/Tc-99m medical radioisotope production is proposed. The modified LEU Cintichem process for Mo-99 extraction which has been licensed and demonstrated commercially for decades by BATAN is taken into account as a key design consideration. The design characteristics and main parameters are identified and the advantageous aspects are shown by comparing with the BATAN's existing Mo-99 supply chain which uses a heterogeneous reactor (RSG GAS multipurpose reactor)

  16. Spatially resolved assessment of hepatic function using 99mTc-IDA SPECT

    SciTech Connect (OSTI)

    Wang, Hesheng; Cao, Yue

    2013-09-15

    Purpose: 99mTc-iminodiacetic acid (IDA) hepatobiliary imaging is usually quantified for hepatic function on the entire liver or regions of interest (ROIs) in the liver. The authors presented a method to estimate the hepatic extraction fraction (HEF) voxel-by-voxel from single-photon emission computed tomography (SPECT)/CT with a 99mTc-labeled IDA agent of mebrofenin and evaluated the spatially resolved HEF measurements with an independent physiological measurement.Methods: Fourteen patients with intrahepatic cancers were treated with radiation therapy (RT) and imaged by 99mTc-mebrofenin SPECT before and 1 month after RT. The dynamic SPECT volumes were with a resolution of 3.9 × 3.9 × 2.5 mm{sup 3}. Throughout the whole liver with approximate 50 000 voxels, voxelwise HEF quantifications were estimated and compared between using arterial input function (AIF) from the heart and using vascular input function (VIF) from the spleen. The correlation between mean of the HEFs over the nontumor liver tissue and the overall liver function measured by Indocyanine green clearance half-time (T1/2) was assessed. Variation of the voxelwise estimation was evaluated in ROIs drawn in relatively homogeneous regions of the livers. The authors also examined effects of the time range parameter on the voxelwise HEF quantification.Results: Mean of the HEFs over the liver estimated using AIF significantly correlated with the physiological measurement T1/2 (r= 0.52, p= 0.0004), and the correlation was greatly improved by using VIF (r= 0.79, p < 0.0001). The parameter of time range for the retention phase did not lead to a significant difference in the means of the HEFs in the ROIs. Using VIF and a retention phase time range of 7–30 min, the relative variation of the voxelwise HEF in the ROIs was 10%± 6% of respective mean HEF.Conclusions: The voxelwise HEF derived from 99mTc-IDA SPECT by the deconvolution analysis is feasible to assess the spatial distribution of hepatic function in the

  17. Interfacial Electron-Phonon Coupling as the Cause of Enhanced Tc in

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

    Single-layer FeSe Films on SrTiO3 | Stanford Synchrotron Radiation Lightsource Interfacial Electron-Phonon Coupling as the Cause of Enhanced Tc in Single-layer FeSe Films on SrTiO3 Friday, February 27, 2015 In the past several years, multiple studies have confirmed superconductivity in single-unit-cell-thick films of iron selenide (1UC FeSe) grown on strontium titanate (STO), with gap opening temperatures approaching the boiling point of liquid nitrogen, which is nearly a decade higher than

  18. trans-K3[TcO2(CN)4

    SciTech Connect (OSTI)

    Chatterjee, Sayandev; Del Negro, Andrew S; Edwards, Matthew K; Twamley, Brendan; Krause, Jeanette A; Bryan, Samuel A

    2010-07-14

    The dioxotetracyanotechnetate anion, [TcO2(CN)4]3-, of the title complex has octahedral symmetry. The technetium is located on a center of inversion and is bound by two oxygen atoms and four cyano ligands. The Tc=O bond distance of 1.7721 (12) Å is consistent with double bond character. The potassium cations [located on special (1/2,0,1) and general positions] reside in octahedral or tetrahedral environments; interionic K···O and K···N interactions occur in the 2.7877 (19)-2.8598 (15) Å range.

  19. Thrombus detection using a Tc-99m labeled antifibrin monoclonal antibody (MoAb). Experiments in vitro and in animals

    SciTech Connect (OSTI)

    Wasser, M.N.; Pauwels, E.K.; Nieuwenhuizen, W. )

    1990-01-01

    This paper describes the production and characterization of an antifibrin monoclonal antibody, produced by immunizing mice with fibrinogen degradation fragment Y. The antibody (designated Y22) is directed against a conformation dependent epitope in the D-domain of fibrin Y22 was labeled with the radionuclide Tc-99m. Experiments in vitro and in rats are presented which show the potential of scintigraphic detection of thrombi with Tc-99m-Y22. Preliminary results show that immunoscintigraphy of thrombi may also have potential for the monitoring of thrombolytic therapy (eg with t-PA).

  20. Method and kit for the selective labeling of red blood cells in whole blood with TC-99M

    DOE Patents [OSTI]

    Srivastava, Suresh C.; Babich, John W.; Straub, Rita; Richards, Powell

    1988-01-01

    Disclosed herein are a method and kit for the preparation of .sup.99m Tc labeled red blood cells using whole blood in a closed sterile system containing stannous tin in a form such that it will enter the red blood cells and be available therein for the reduction of technetium.

  1. Method and kit for the selective labeling of red blood cells in whole blood with Tc-99m

    DOE Patents [OSTI]

    Srivastava, S.C.; Babich, J.W.; Straub, R.; Richards, P.

    1988-07-05

    Disclosed herein are a method and kit for the preparation of [sup 99m]Tc labeled red blood cells using whole blood in a closed sterile system containing stannous tin in a form such that it will enter the red blood cells and be available for the reduction of technetium. No Drawings

  2. Photophysics and Luminescence Spectroelectrochemistry of [Tc(dmpe)3]+/2+ (dmpe = 1,2-bis(dimethylphosphino)ethane)

    SciTech Connect (OSTI)

    Chatterjee, Sayandev; Del Negro, Andrew S.; Smith, Frances N.; Wang, Zheming; Hightower, Sean E.; Sullivan, Brian P.; Heineman, William R.; Seliskar, Carl J.; Bryan, Samuel A.

    2013-12-05

    The ligand-to-metal charge transfer (LMCT) excited state luminescence of [Tc(dmpe)3]2+ (dmpe is 1,2-bis-(dimethylphosphino)ethane) has been measured in solution at room temperature, and is compared to its Re analogue. Surprisingly, both [M(dmpe)3]2+* (M = Re, Tc) species have extremely large excited-state potentials (ESPs) as oxidants - the highest for any simple coordination complex of a transition metal. Furthermore, this potential is available using a photon of visible light (calculated for M = Re(Tc); E1/2* = +2.61(2.48) V versus SCE; ?max = 526(585) nm). Open shell TDDFT calculations support the assignment of the lowest energy transition in both the technetium and rhenium complexes to be a doublet-doublet process that involve predominantly LMCT (dmpe-to-metal) character and is in agreement with past assignments for the Re system. As expected for highly oxidizing excited state potentials, quenching is observed for the excited states by both the rhenium and technetium complexes. Stern-Volmer analysis resulted in quenching parameters for both the rhenium and technetium complexes under identical conditions, and are compared using Rehm-Weller analysis. Of particular interest is the fact that both benzene and toluene are oxidized by both the Re and Tc systems.

  3. New Synthesis Route and Characterization of Siderite (FeCO{sub 3} ) and Coprecipitation of {sup 99}Tc

    SciTech Connect (OSTI)

    Llorens, Isabelle; Fattahi, Massoud; Grambow, Bernd

    2007-07-01

    Technetium-99 is a long-lived product of nuclear fission. In the ground-waters of European disposal sites Tc is expected to be in the tetravalent state since the geochemical conditions are reducing due to the presence of redox couples such as Fe(II)/Fe(III), and the presence of reducing minerals such as pyrite and siderite (FeCO{sub 3}). Siderite is expected to be formed as well as container corrosion product. Experiments of coprecipitation of Fe{sup 2+} and Tc(IV) were conducted in the laboratory under an inert atmosphere at room temperature. High resolution transmission electron microscopy shows that the co-precipitate is around 3 nm sized particles. Analytical electron microscopy indicates that the precipitate contains 30 atom % of Tc and 70 atom % Fe. The Tc was homogeneously distributed. Selected Area Electron Diffraction does not reveal the formation of siderite, which suggests that the presence of technetium in high concentration inhibit the formation of this phase. (authors)

  4. A field trial of novel bifunctional resins for removing pertechnetate (TcO{sub 4}{sup {minus}}) from contaminated groundwater

    SciTech Connect (OSTI)

    Gu, B.; Liang, L.; Brown, G.M.; Bonnesen, P.V.; Moyer, B.A.; Alexandratos, S.D.; Ober, R.

    1998-03-01

    A field trial using a custom-designed bifunctional synthetic resin prepared at the University of Tennessee and designed to selectively remove pertechnetate (TcO{sub 4}{sup {minus}}) from groundwater was conducted in summer 1997 at the Northwest Plume Pump-and-Treat Facility at the US Department of Energy`s Paducah Gaseous Diffusion Plant (PGDP) site. The bifunctional resin, RO-02-119, was a copolymer of vinylbenzylchloride and divinylbenzene that had been functionalized with trihexylamine and triethylamine. The experiment was a parallel test of the synthetic resin and a commercial resin, Purolite A-520E, to directly compare the performance of the two resins. Purolite resin is currently used by the treatment facility to remove Tc-99 from the contaminated groundwater containing {approximately}1,000 pCi/L TcO{sub 4}{sup {minus}}. A total of {approximately}692,000 bed volumes of groundwater was passed through the column containing the synthetic resin (RO-02-119) whereas only {approximately}205,000 bed volumes of groundwater were passed through the Purolite resin column because of reduced hydraulic conductivity and clogging within the latter column. Despite less groundwater passing through the Purolite resin column, however, the breakthrough of TcO{sub 4}{sup {minus}} occurred earlier in the Purolite column than in the RO-02-119 column.

  5. A technique using {sup 99m}Tc-mebrofenin SPECT for radiotherapy treatment planning for liver cancers or metastases

    SciTech Connect (OSTI)

    Shen, Sui; Jacob, Rojymon; Bender, Luvenia W.; Duan, Jun; Spencer, Sharon A.

    2014-04-01

    Radiotherapy or stereotactic body radiosurgery (SBRT) requires a sufficient functional liver volume to tolerate the treatment. The current study extended the work of de Graaf et al. (2010) [3] on the use of {sup 99m}Tc-mebrofenin imaging for presurgery planning to radiotherapy planning for liver cancer or metastases. Patient was immobilized and imaged in an identical position on a single-photon emission computed tomography/computed tomography (SPECT-CT) system and a radiotherapy simulation CT system. {sup 99m}Tc-mebrofenin SPECT was registered to the planning CT through image registration of noncontrast CT from SPECT-CT system to the radiotherapy planning CT. The voxels with higher uptake of {sup 99m}Tc-mebrofenin were transferred to the planning CT as an avoidance structure in optimizing a 2-arc RapidArc plan for SBRT delivery. Excellent dose coverage to the target and sparing of the healthy remnant liver volume was achieved. This report illustrated a procedure for the use of {sup 99m}Tc-mebrofenin SPECT for optimizing radiotherapy for liver cancers and metastases.

  6. Method for generating a crystalline {sup 99}MoO{sub 3} product and the isolation {sup 99m}Tc compositions therefrom

    DOE Patents [OSTI]

    Bennett, R.G.; Christian, J.D.; Kirkham, R.J.; Tranter, T.J.

    1998-09-01

    An improved method is described for producing {sup 99m}Tc compositions. {sup 100}Mo metal is irradiated with photons in a particle (electron) accelerator to produce {sup 99}Mo metal which is dissolved in a solvent. A solvated {sup 99}Mo product is then dried to generate a supply of {sup 99}MoO{sub 3} crystals. The crystals are thereafter heated at a temperature which will sublimate the crystals and form a gaseous mixture containing vaporized {sup 99m}TcO{sub 3} and vaporized {sup 99m}TcO{sub 2} but will not cause the production of vaporized {sup 99}MoO{sub 3}. The mixture is then combined with an oxidizing gas to generate a gaseous stream containing vaporized {sup 99m}Tc{sub 2}O{sub 7}. Next, the gaseous stream is cooled to a temperature sufficient to convert the vaporized {sup 99m}Tc{sub 2}O{sub 7} into a condensed {sup 99m}Tc-containing product. The product has high purity levels resulting from the use of reduced temperature conditions and ultrafine crystalline {sup 99}MoO{sub 3} starting materials with segregated {sup 99m}Tc compositions therein which avoid the production of vaporized {sup 99}MoO{sub 3} contaminants. 1 fig.

  7. Method for generating a crystalline .sup.99 MoO.sub.3 product and the isolation .sup.99m Tc compositions therefrom

    DOE Patents [OSTI]

    Bennett, Ralph G.; Christian, Jerry D.; Kirkham, Robert J.; Tranter, Troy J.

    1998-01-01

    An improved method for producing .sup.99m Tc compositions. .sup.100 Mo metal is irradiated with photons in a particle (electron) accelerator to produce .sup.99 Mo metal which is dissolved in a solvent. A solvated .sup.99 Mo product is then dried to generate a supply of .sup.99 MoO.sub.3 crystals. The crystals are thereafter heated at a temperature which will sublimate the crystals and form a gaseous mixture containing vaporized .sup.99m TcO.sub.3 and vaporized .sup.99m TcO.sub.2 but will not cause the production of vaporized .sup.99 MoO.sub.3. The mixture is then combined with an oxidizing gas to generate a gaseous stream containing vaporized .sup.99m Tc.sub.2 O.sub.7. Next, the gaseous stream is cooled to a temperature sufficient to convert the vaporized .sup.99m Tc.sub.2 O.sub.7 into a condensed .sup.99m Tc-containing product. The product has high purity levels resulting from the use of reduced temperature conditions and ultrafine crystalline .sup.99 MoO.sub.3 starting materials with segregated .sup.99m Tc compositions therein which avoid the production of vaporized .sup.99 MoO.sub.3 contaminants.

  8. Nodal bilayer-splitting controlled by spin-orbit interactions in underdoped high-Tc cuprates

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

    Harrison, N.; Ramshaw, B. J.; Shekhter, A.

    2015-06-03

    The highest superconducting transition temperatures in the cuprates are achieved in bilayer and trilayer systems, highlighting the importance of interlayer interactions for high Tc. It has been argued that interlayer hybridization vanishes along the nodal directions by way of a specific pattern of orbital overlap. Recent quantum oscillation measurements in bilayer cuprates have provided evidence for a residual bilayer-splitting at the nodes that is sufficiently small to enable magnetic breakdown tunneling at the nodes. Here we show that several key features of the experimental data can be understood in terms of weak spin-orbit interactions naturally present in bilayer systems, whosemore » primary effect is to cause the magnetic breakdown to be accompanied by a spin flip. These features can now be understood to include the equidistant set of three quantum oscillation frequencies, the asymmetry of the quantum oscillation amplitudes in c-axis transport compared to ab-plane transport, and the anomalous magnetic field angle dependence of the amplitude of the side frequencies suggestive of small effective g-factors. We suggest that spin-orbit interactions in bilayer systems can further affect the structure of the nodal quasiparticle spectrum in the superconducting phase. PACS numbers: 71.45.Lr, 71.20.Ps, 71.18.+y« less

  9. Mass Measurements of Very Neutron-Deficient Mo and Tc Isotopes and Their Impact on rp Process Nucleosynthesis

    SciTech Connect (OSTI)

    Haettner, E.; Plass, W. R.; Scheidenberger, C.; Ackermann, D.; Block, M.; Eliseev, S.; Herfurth, F.; Hessberger, F. P.; Hofmann, S.; Kluge, H.-J.; Audi, G.; Blaum, K.; Ketter, J.; Fleckenstein, T.; Ketelaer, J.; Marx, G.; Schweikhard, L.; Mazzocco, M.; Novikov, Yu. N.; Vorobjev, G.

    2011-03-25

    The masses of ten proton-rich nuclides, including the N=Z+1 nuclides {sup 85}Mo and {sup 87}Tc, were measured with the Penning trap mass spectrometer SHIPTRAP. Compared to the Atomic Mass Evaluation 2003 a systematic shift of the mass surface by up to 1.6 MeV is observed causing significant abundance changes of the ashes of astrophysical x-ray bursts. Surprisingly low {alpha} separation energies for neutron-deficient Mo and Tc are found, making the formation of a ZrNb cycle in the rp process possible. Such a cycle would impose an upper temperature limit for the synthesis of elements beyond Nb in the rp process.

  10. V-183: Cisco TelePresence TC and TE Bugs Let Remote Users Deny Service and Remote Adjacent Authenticated Users Gain Root Shell Access

    Broader source: Energy.gov [DOE]

    Cisco TelePresence TC and TE Software contain two vulnerabilities in the implementation of the Session Initiation Protocol (SIP) that could allow an unauthenticated remote attacker to cause a denial of service (DoS) condition. Additionally, Cisco TelePresence TC Software contain an adjacent root access vulnerability that could allow an attacker on the same physical or logical Layer-2 network as the affected system to gain an unauthenticated root shell.

  11. Fiscal Year 2010 Summary Report on the Epsilon-Metal Phase as a Waste Form for 99 Tc

    SciTech Connect (OSTI)

    Strachan, Denis M.; Crum, Jarrod V.; Buck, Edgar C.; Riley, Brian J.; Zumhoff, Mac R.

    2010-09-30

    Epsilon metal (ε-metal) is generated in nuclear fuel during irradiation. This metal consists of Pd, Ru, Rh, Mo, and some Te. These accumulate at the UO2 grain boundaries as small (ca 5 µm) particles. These metals have limited solubility in the acid used to dissolve fuel during reprocessing and in typical borosilicate glass. These must be treated separately to improve overall waste loading in glass. This low solubility and their survival in 2 Gy-old natural reactors led us to investigate them as a waste form for the immobilization of 99Tc and 107Pd, two very long-lived isotopes.

  12. Anisotropic Hc2 , thermodynamic and transport measurements, and pressure dependence of Tc in K2Cr3As3 single crystals

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

    Kong, Tai; Bud'ko, Sergey L.; Canfield, Paul C.

    2015-01-30

    We present a detailed study of single crystalline K2Cr3As3 and analyze its thermodynamic and transport properties, anisotropic Hc2(T), and initial pressure dependence of Tc. In zero field, the temperature-dependent resistivity is metallic. Deviation from a linear temperature dependence is evident below 100 K and a T3 dependence is roughly followed from just above Tc (~10K) to ~40K. Anisotropic Hc2(T) data were measured up to 140 kOe with field applied along and perpendicular to the rodlike crystals. For the applied field perpendicular to the rod, Hc2(T) is linear with a slope ~–70 kOe/K. For field applied along the rod, the slopemore » is about –120 kOe/K below 70 kOe. Above 70 kOe, the magnitude of the slope decreases to ~–70 kOe/K. The electronic specific heat coefficient γ, just above Tc, is 73 mJ/mol K2; the Debye temperature ΘD is 220 K. As a result, the specific heat jump at the superconducting transition ΔC~2.2γTc. Finally, for hydrostatic pressures up to ~7 kbar, Tc decreases under pressure linearly at a rate of –0.034K/kbar.« less

  13. Assessment of RELAP/MOD3 using BETHSY 6.2TC 6-inch cold leg side break comparative test

    SciTech Connect (OSTI)

    Chung, Young-Jong; Jeong, Jae-Jun; Chang, Won-Pyo; Kim, Dong-Su

    1996-10-01

    This report presents the results of the RELAP5/MOD3 Version 7j assessment on BETHSY 6.2TC. BETHSY 6.2TC test corresponding to a six inch cold leg break LOCA of the Pressurizer Water Reactor(PWR). The primary objective of the test was to provide reference data of two facilities of different scales (BETHSY and LSTF facility). On the other hand, the present calculation aims at analysis of RELAP5/N4OD3 capability on the small break LOCA simulation, The results of calculation have shown that the RELAP5/MOD3 reasonably predicts occurrences as well as trends of the major phenomena such as primary pressure, timing of loop seal clearing, liquid hold up, etc. However, some disagreements also have been found in the predictions of loop seal clearing, collapsed core water level after loop seal clearing, and accumulator injection behaviors. For better understanding of discrepancies in same predictions, several sensitivity calculations have been performed as well. These include the changes of two-phase discharge coefficient at the break junction and some corrections of the interphase drag term. As result, change of a single parameter has not improved the overall predictions and it has been found that the interphase drag model has still large uncertainties.

  14. NMR characterization of sulphur substitution effects in the KxFe2-ySe2-zSz high-Tc superconductor

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

    Torchetti, D. A.; Imai, T.; Lei, H. C.; Petrovic, C.

    2012-04-17

    We present a⁷⁷ Se NMR study of the effect of S substitution in the high-Tc superconductor KxFe2-ySe2-zSz in a temperature range up to 250 K. We examine two S concentrations, with z=0.8 (Tc~ 26 K) and z=1.6 (nonsuperconducting). The samples containing sulphur exhibit broader NMR line shapes than the KxFe₂Se₂ sample due to local disorder in the Se environment. Our Knight shift ⁷⁷K data indicate that in all samples, uniform spin susceptibility decreases with temperature, and that the magnitude of the Knight shift itself decreases with increased S concentration. In addition, S substitution progressively suppresses low-frequency spin fluctuations. None ofmore » the samples exhibit an enhancement of low-frequency antiferromagnetic spin fluctuations near Tc in 1/T₁T, as seen in FeSe.« less

  15. Evidence for a new excitation at the interface between a high-Tc superconductor and a topological insulator

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

    Zareapour, Parisa; Hayat, Alex; Zhao, Shu Yang F.; Kreshchuk, Michael; Lee, Yong Kiat; Reijnders, Anjan A.; Jain, Achint; Xu, Zhijun; Liu, T. S.; Gu, G. D.; et al

    2014-12-09

    In this research, high-temperature superconductors exhibit a wide variety of novel excitations. If contacted with a topological insulator, the lifting of spin rotation symmetry in the surface states can lead to the emergence of unconventional superconductivity and novel particles. In pursuit of this possibility, we fabricated high critical-temperature (Tc ~ 85 K) superconductor/topological insulator (Bi₂Sr₂CaCu₂O₈₊δ/Bi₂Te₂Se) junctions. Below 75 K, a zero-bias conductance peak (ZBCP) emerges in the differential conductance spectra of this junction. The magnitude of the ZBCP is suppressed at the same rate for magnetic fields applied parallel or perpendicular to the junction. Furthermore, it can still be observedmore » and does not split up to at least 8.5 T. The temperature and magnetic field dependence of the excitation we observe appears to fall outside the known paradigms for a ZBCP.« less

  16. Attenuation compensation in TC-99M SPECT brain imaging: Use of attenuation maps derived from tranmission versus emission data

    SciTech Connect (OSTI)

    Pan, T.S.; Licho, R.; Penney, B.C. [Univ. of Massachusetts Mecical Center, Worcester, MA (United States)] [and others

    1994-05-01

    This study compares reconstructions of Tc-99m brain SPECT studies made using two methods of estimating the attenuation map: (1) transmission scanning, and (2) segmenting reconstructions of emission data and assigning attenuation coefficient values. A three-head SPECT system with fan beam collimators was used. Transmission scanning was performed using a line source at the focal line of a fan beam collimator right after the regular emission scan. The higher attenuation of the skull and the lower attenuation in the sinus cavities were identifiable despite the noise in the reconstructed transmission data due to: (1) the contamination of the transmission data by emission photons, (2) the maximum acquisition count rate imposed by the SPECT system, and (3) the clinical scanning time. Emission data were recorded using both photopeak and Compton scatter energy windows. Outlines of the head and the maxillary sinus could be obtained using only the Compton scatter reconstructions, whereas identifying the skull regions and the frontal sinus required the photopeak data as well. We placed appropriate linear attenuation coefficients in the soft tissue, bone, sinus and air regions (0.15,. 0.22, 0, and 0 cm{sup -1}) and blurred this attenuation map with a Gaussian kernel of about 0.2 cm standard deviation to obtain the attenuation map based on the emission data. Reconstructions were computed using the maximum likelihood expectation maximization algorithm with Siddon`s ray-tracing algorithm. Reconstructions based on the two attenuation maps were compared quantitatively on the patient data. The differences noted were quite small. These results imply that attenuation correction based on emission data alone may be adequate for Tc-99m SPECT brain imaging.

  17. High-Tc superconductivity at the interface between the CaCuO2 and SrTiO3 insulating oxides

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

    Di Castro, D.; Cantoni, C.; Ridolfi, F.; Aruta, C.; Tebano, A.; Yang, N.; Balestrino, G.

    2015-09-28

    At interfaces between complex oxides it is possible to generate electronic systems with unusual electronic properties, which are not present in the isolated oxides. One important example is the appearance of superconductivity at the interface between insulating oxides, although, until now, with very low Tc. We report the occurrence of high Tc superconductivity in the bilayer CaCuO2/SrTiO3, where both the constituent oxides are insulating. In order to obtain a superconducting state, the CaCuO2/SrTiO3 interface must be realized between the Ca plane of CaCuO2 and the TiO2 plane of SrTiO3. Only in this case can oxygen ions be incorporated in themore » interface Ca plane, acting as apical oxygen for Cu and providing holes to the CuO2 planes. In addition, a detailed hole doping spatial profile can be obtained by scanning transmission electron microscopy and electron-energy-loss spectroscopy at the O K edge, clearly showing that the (super)conductivity is confined to about 1–2 CaCuO2 unit cells close to the interface with SrTiO3. The results obtained for the CaCuO2/SrTiO3 interface can be extended to multilayered high Tc cuprates, contributing to explaining the dependence of Tc on the number of CuO2 planes in these systems.« less

  18. Highly Selective Colorimetric and Luminescence Response of a Square-Planar Platinum(II) Terpyridyl Complex to Aqueous TcO4-

    SciTech Connect (OSTI)

    Chatterjee, Sayandev; Norton, Amie E.; Edwards, Matthew K.; Peterson, James M.; Taylor, Stephen D.; Bryan, Samuel A.; Andersen, Amity; Govind, Niranjan; Albrecht-Schmitt, Thomas E.; Connick, William; Levitskaia, Tatiana G.

    2015-10-08

    In an effort to address the need for a rapid, selective and economical detection technique for aqueous pertechnetate (TcO4-) anion based on recognition at the molecular level, simple salts of transition metal complexes that undergo a distinct spectroscopic change upon exposure to aqueous anions were explored. The Pt(II) complex [Pt(tpy)Br]SbF6 (tpy=2,2';6',2"-terpyridine) undergoes a dramatic color change and intense luminescence response upon TcO4- uptake due to concomitant enhancement of Pt•••Pt interactions. The spectroscopic response was highly selective and quantitative for aqueous TcO4- among other competing anions. Complimentary Raman spectroscopy and microscopy techniques, structural determination and theoretical methods were employed to achieve molecular-level understanding of the mechanism of the response to aqueous TcO4-.

  19. Implications of CT noise and artifacts for quantitative {sup 99m}Tc SPECT/CT imaging

    SciTech Connect (OSTI)

    Hulme, K. W.; Kappadath, S. C.

    2014-04-15

    Purpose: This paper evaluates the effects of computed tomography (CT) image noise and artifacts on quantitative single-photon emission computed-tomography (SPECT) imaging, with the aim of establishing an appropriate range of CT acquisition parameters for low-dose protocols with respect to accurate SPECT attenuation correction (AC). Methods: SPECT images of two geometric and one anthropomorphic phantom were reconstructed iteratively using CT scans acquired at a range of dose levels (CTDI{sub vol} = 0.4 to 46 mGy). Resultant SPECT image quality was evaluated by comparing mean signal, background noise, and artifacts to SPECT images reconstructed using the highest dose CT for AC. Noise injection was performed on linear-attenuation (μ) maps to determine the CT noise threshold for accurate AC. Results: High levels of CT noise (σ ∼ 200–400 HU) resulted in low μ-maps noise (σ ∼ 1%–3%). Noise levels greater than ∼10% in 140 keV μ-maps were required to produce visibly perceptible increases of ∼15% in {sup 99m}Tc SPECT images. These noise levels would be achieved at low CT dose levels (CTDI{sub vol} = 4 μGy) that are over 2 orders of magnitude lower than the minimum dose for diagnostic CT scanners. CT noise could also lower (bias) the expected μ values. The relative error in reconstructed SPECT signal trended linearly with the relative shift in μ. SPECT signal was, on average, underestimated in regions corresponding with beam-hardening artifacts in CT images. Any process that has the potential to change the CT number of a region by ∼100 HU (e.g., misregistration between CT images and SPECT images due to motion, the presence of contrast in CT images) could introduce errors in μ{sub 140} {sub keV} on the order of 10%, that in turn, could introduce errors on the order of ∼10% into the reconstructed {sup 99m}Tc SPECT image. Conclusions: The impact of CT noise on SPECT noise was demonstrated to be negligible for clinically achievable CT parameters. Because

  20. Prototype Development of Remote Operated Hot Uniaxial Press (ROHUP) to Fabricate Advanced Tc-99 Bearing Ceramic Waste Forms - 13381

    SciTech Connect (OSTI)

    Alaniz, Ariana J.; Delgado, Luc R.; Werbick, Brett M.; Hartmann, Thomas

    2013-07-01

    The objective of this senior student project is to design and build a prototype construction of a machine that simultaneously provides the proper pressure and temperature parameters to sinter ceramic powders in-situ to create pellets of rather high densities of above 90% (theoretical). This ROHUP (Remote Operated Hot Uniaxial Press) device is designed specifically to fabricate advanced ceramic Tc-99 bearing waste forms and therefore radiological barriers have been included in the system. The HUP features electronic control and feedback systems to set and monitor pressure, load, and temperature parameters. This device operates wirelessly via portable computer using Bluetooth{sup R} technology. The HUP device is designed to fit in a standard atmosphere controlled glove box to further allow sintering under inert conditions (e.g. under Ar, He, N{sub 2}). This will further allow utilizing this HUP for other potential applications, including radioactive samples, novel ceramic waste forms, advanced oxide fuels, air-sensitive samples, metallic systems, advanced powder metallurgy, diffusion experiments and more. (authors)

  1. Sci—Thur PM: Imaging — 04: An iterative triple energy window (TEW) approach to cross talk correction in quantitative small animal Tc99m and In111 SPECT

    SciTech Connect (OSTI)

    Prior, P; Timmins, R; Wells, R G

    2014-08-15

    Dual isotope SPECT allows simultaneous measurement of two different tracers in vivo. With In111 (emission energies of 171keV and 245keV) and Tc99m (140keV), quantification of Tc99m is degraded by cross talk from the In111 photons that scatter and are detected at an energy corresponding to Tc99m. TEW uses counts recorded in two narrow windows surrounding the Tc99m primary window to estimate scatter. Iterative TEW corrects for the bias introduced into the TEW estimate resulting from un-scattered counts detected in the scatter windows. The contamination in the scatter windows is iteratively estimated and subtracted as a fraction of the scatter-corrected primary window counts. The iterative TEW approach was validated with a small-animal SPECT/CT camera using a 2.5mL plastic container holding thoroughly mixed Tc99m/In111 activity fractions of 0.15, 0.28, 0.52, 0.99, 2.47 and 6.90. Dose calibrator measurements were the gold standard. Uncorrected for scatter, the Tc99m activity was over-estimated by as much as 80%. Unmodified TEW underestimated the Tc99m activity by 13%. With iterative TEW corrections applied in projection space, the Tc99m activity was estimated within 5% of truth across all activity fractions above 0.15. This is an improvement over the non-iterative TEW, which could not sufficiently correct for scatter in the 0.15 and 0.28 phantoms.

  2. High-Tc Superconductor

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

    Donghui Lu, Kyle Shen, and Zhi-Xun Shen Departments of Applied Physics, Physics, and Stanford Synchrotron Radiation Laboratory, Stanford University, Stanford, CA 94305 High-temperature superconductors (HTSC's), following their remarkable discovery in 1986, continue to be at the center stage of modern condensed matter physics. Despite great efforts from both theoretical and experimental sides, the mechanism of HTSC still remains elusive. One of the most peculiar aspects of HTSC's is that their

  3. Predictive Models for Regional Hepatic Function Based on 99mTc-IDA SPECT and Local Radiation Dose for Physiologic Adaptive Radiation Therapy

    SciTech Connect (OSTI)

    Wang, Hesheng; Feng, Mary; Frey, Kirk A.; Ten Haken, Randall K.; Lawrence, Theodore S.; Cao, Yue

    2013-08-01

    Purpose: High-dose radiation therapy (RT) for intrahepatic cancer is limited by the development of liver injury. This study investigated whether regional hepatic function assessed before and during the course of RT using 99mTc-labeled iminodiacetic acid (IDA) single photon emission computed tomography (SPECT) could predict regional liver function reserve after RT. Methods and Materials: Fourteen patients treated with RT for intrahepatic cancers underwent dynamic 99mTc-IDA SPECT scans before RT, during, and 1 month after completion of RT. Indocyanine green (ICG) tests, a measure of overall liver function, were performed within 1 day of each scan. Three-dimensional volumetric hepatic extraction fraction (HEF) images of the liver were estimated by deconvolution analysis. After coregistration of the CT/SPECT and the treatment planning CT, HEF dose–response functions during and after RT were generated. The volumetric mean of the HEFs in the whole liver was correlated with ICG clearance time. Three models, dose, priori, and adaptive models, were developed using multivariate linear regression to assess whether the regional HEFs measured before and during RT helped predict regional hepatic function after RT. Results: The mean of the volumetric liver HEFs was significantly correlated with ICG clearance half-life time (r=−0.80, P<.0001), for all time points. Linear correlations between local doses and regional HEFs 1 month after RT were significant in 12 patients. In the priori model, regional HEF after RT was predicted by the planned dose and regional HEF assessed before RT (R=0.71, P<.0001). In the adaptive model, regional HEF after RT was predicted by regional HEF reassessed during RT and the remaining planned local dose (R=0.83, P<.0001). Conclusions: 99mTc-IDA SPECT obtained during RT could be used to assess regional hepatic function and helped predict post-RT regional liver function reserve. This could support individualized adaptive radiation treatment strategies

  4. Application of Surface Analysis Methods to Nanomaterials: Summaryof ISO/TC 201 Technical Report: ISO 14187:2011 -Surface Chemical Analysis- Characterization of Nanomaterials

    SciTech Connect (OSTI)

    Baer, Donald R.

    2012-09-01

    ISO Technical Report (TR) 14187 provides an introduction to (and examples of) the information that can be obtained about nanostructured materials using surface-analysis tools. In addition, both general issues and challenges associated with characterising nanostructured materials and the specific opportunities and challenges associated with individual analytical methods are identified. As the size of objects or components of materials approaches a few nanometres, the distinctions among 'bulk', 'surface' and 'particle' analysis blur. This Technical Report focuses on issues specifically relevant to surface chemical analysis of nanostructured materials. The report considers a variety of analysis methods but focuses on techniques that are in the domain of ISO/TC 201 including Auger electron spectroscopy, X-ray photoelectron spectroscopy, secondary ion mass spectrometry, and scanning probe microscopy. Measurements of nanoparticle surface properties such as surface potential that are often made in a solution are not discussed.

  5. Adaptation of methodology to select structural alternatives of one-way slab in residential building to the guidelines of the European Committee for Standardization (CEN/TC 350)

    SciTech Connect (OSTI)

    Fraile-Garcia, Esteban; Ferreiro-Cabello, Javier; Martinez-Camara, Eduardo; Jimenez-Macias, Emilio

    2015-11-15

    The European Committee for Standardization (CEN) through its Technical Committee CEN/TC-350 is developing a series of standards for assessing the building sustainability, at both product and building levels. The practical application of the selection (decision making) of structural alternatives made by one-way slabs leads to an intermediate level between the product and the building. Thus the present study addresses this problem of decision making, following the CEN guidelines and incorporating relevant aspects of architectural design into residential construction. A life cycle assessment (LCA) is developed in order to obtain valid information for the decision making process (the LCA was developed applying CML methodology although Ecoindicator99 was used in order to facilitate the comparison of the values); this information (the carbon footprint values) is contrasted with other databases and with the information from the Environmental Product Declaration (EPD) of one of the lightening materials (expanded polystyrene), in order to validate the results. Solutions of different column disposition and geometries are evaluated in the three pillars of sustainable construction on residential construction: social, economic and environmental. The quantitative analysis of the variables used in this study enables and facilitates an objective comparison in the design stage by a responsible technician; the application of the proposed methodology reduces the possible solutions to be evaluated by the expert to 12.22% of the options in the case of low values of the column index and to 26.67% for the highest values. - Highlights: • Methodology for selection of structural alternatives in buildings with one-way slabs • Adapted to CEN guidelines (CEN/TC-350) for assessing the building sustainability • LCA is developed in order to obtain valid information for the decision making process. • Results validated comparing carbon footprint, databases and Env. Product Declarations

  6. Sci—Thur PM: Imaging — 05: Calibration of a SPECT/CT camera for quantitative SPECT with {sup 99m}Tc

    SciTech Connect (OSTI)

    Gaudin, Émilie; Montégiani, Jean-François; Després, Philippe; Beauregard, Jean-Mathieu

    2014-08-15

    While quantitation is the norm in PET, it is not widely available yet in SPECT. This work's aim was to calibrate a commercially available SPECT/CT system to perform quantitative SPECT. Counting sensitivity, dead-time (DT) constant and partial volume effect (PVE) of the system were assessed. A dual-head Siemens SymbiaT6 SPECT/CT camera equipped with low energy high-resolution collimators was studied. {sup 99m}Tc was the radioisotope of interest because of its wide usage in nuclear medicine. First, point source acquisitions were performed (activity: 30–990MBq). Further acquisitions were then performed with a uniform Jaszczak phantom filled with water at high activity (25–5000MBq). PVE was studied using 6 hot spheres (diameters: 9.9–31.2 mm) filled with {sup 99m}Tc (2.8MBq/cc) in the Jaszczak phantom, which was: (1) empty, (2) water-filled and (3) water-filled with low activity (0.1MBq/cc). The data was reconstructed with the Siemens's Flash3D iterative algorithm with 4 subsets and 8 iterations, attenuation-correction (AC) and scatter-correction (SC). DT modelling was based on the total spectrum counting rate. Sensitivity was assessed using AC-SC reconstructed SPECT data. Sensitivity and DT for the sources were 99.51±1.46cps/MBq and 0.60±0.04µs. For the phantom, sensitivity and DT were 109.9±2.3cps/MBq and 0.62±0.13µs. The recovery-coefficient varied from 5% for the 9.9mm, to 80% for the 31.2mm spheres. With our calibration methods, both sensitivity and DT constant of the SPECT camera had little dependence on the object geometry and attenuation. For small objects of known size, recovery-coefficient can be applied to correct PVE. Clinical quantitative SPECT appears to be possible and has many potential applications.

  7. Travel to France as Chief US Delegate at a meeting of International Standards Organization ISO/TC-85, ``Nuclear Technology``. Foreign trip report, March 17--March 26, 1994

    SciTech Connect (OSTI)

    Westfall, R.M.

    1994-04-11

    As overall US Advisor for ISO/TC-85, SC-5, Dr. Westfall met with (1) Work Group 1, ``Measurement Techniques for the Chemical and Physical Characterization of UF{sub 6}, UO{sub 2}, and Mixed Oxide,`` on Monday, March 21, (2) Work Group 5, ``Standardization of Measurement Methods for the Characterization of Solid and Solidified Waste Forms, and for the Corrosion of their Primary Containers,`` on Tuesday, March 22; and (3) the full Subcommittee-5 on Wednesday, March 23. The status of work by all seven work groups in SC-5 was reported. Those having to do with nuclear fuel transportation (WG-4: UF, Containers, WG-9: Cask Trunnions, and WG-10: Cask Confinement) either have approved standards or drafts at an advanced stage of development. These work group convenors were asked to maintain their membership and establish new work areas in the field of nuclear fuel packaging. Definition of scope for new work is to be done in coordination with the interested staff members of the International Atomic Energy Agency, Vienna, Austria. On Thursday, March 24, the Cogema-Marcoule Plant staff hosted the SC-5 members to technical tours of their nuclear fuel reprocessing and waste vitrification and storage facilities.

  8. Wang-Landau density of states based study of the folding-unfolding transition in the mini-protein Trp-cage (TC5b)

    SciTech Connect (OSTI)

    Singh, Priya; Sarkar, Subir K.; Bandyopadhyay, Pradipta

    2014-07-07

    We present the results of a high-statistics equilibrium study of the folding/unfolding transition for the 20-residue mini-protein Trp-cage (TC5b) in water. The ECEPP/3 force field is used and the interaction with water is treated by a solvent-accessible surface area method. A Wang-Landau type simulation is used to calculate the density of states and the conditional probabilities for the various values of the radius of gyration and the number of native contacts at fixed values of energyalong with a systematic check on their convergence. All thermodynamic quantities of interest are calculated from this information. The folding-unfolding transition corresponds to a peak in the temperature dependence of the computed specific heat. This is corroborated further by the structural signatures of folding in the distributions for radius of gyration and the number of native contacts as a function of temperature. The potentials of mean force are also calculated for these variables, both separately and jointly. A local free energy minimum, in addition to the global minimum, is found in a temperature range substantially below the folding temperature. The free energy at this second minimum is approximately 5?k{sub B}T higher than the value at the global minimum.

  9. TC_CLOUD_REGIME.cdr

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

    intensity (e.g. May and Ballinger, 2007) Resulting Cloud Properties Examine rain DSD using polarimetric radar Examine ice cloud properties using MMCR and MPL Expect...

  10. TU-F-12A-04: Differential Radiation Avoidance of Functional Liver Regions Defined by 99mTc-Sulfur Colloid SPECT/CT with Proton Therapy

    SciTech Connect (OSTI)

    Bowen, S; Miyaoka, R; Kinahan, P; Sandison, G; Vesselle, H; Nyflot, M; Apisarnthanarax, S; Saini, J; Wong, T

    2014-06-15

    Purpose: Radiotherapy for hepatocellular carcinoma patients is conventionally planned without consideration of spatial heterogeneity in hepatic function, which may increase risk of radiation-induced liver disease. Pencil beam scanning (PBS) proton radiotherapy (pRT) plans were generated to differentially decrease dose to functional liver volumes (FLV) defined on [{sup 99m}Tc]sulfur colloid (SC) SPECT/CT images (functional avoidance plans) and compared against conventional pRT plans. Methods: Three HCC patients underwent SC SPECT/CT scans for pRT planning acquired 15 min post injection over 24 min. Images were reconstructed with OSEM following scatter, collimator, and exhale CT attenuation correction. Functional liver volumes (FLV) were defined by liver:spleen uptake ratio thresholds (43% to 90% maximum). Planning objectives to FLV were based on mean SC SPECT uptake ratio relative to GTV-subtracted liver and inversely scaled to mean liver dose of 20 Gy. PTV target coverage (V{sub 95}) was matched between conventional and functional avoidance plans. PBS pRT plans were optimized in RayStation for single field uniform dose (SFUD) and systematically perturbed to verify robustness to uncertainty in range, setup, and motion. Relative differences in FLV DVH and target dose heterogeneity (D{sub 2}-D{sub 98})/D50 were assessed. Results: For similar liver dose between functional avoidance and conventional PBS pRT plans (D{sub mean}?5% difference, V{sub 18Gy}?1% difference), dose to functional liver volumes were lower in avoidance plans but varied in magnitude across patients (FLV{sub 70%max} D{sub mean}?26% difference, V{sub 18Gy}?8% difference). Higher PTV dose heterogeneity in avoidance plans was associated with lower functional liver dose, particularly for the largest lesion [(D{sub 2}-D{sub 98})/D{sub 50}=13%, FLV{sub 90%max}=50% difference]. Conclusion: Differential avoidance of functional liver regions defined on sulfur colloid SPECT/CT is feasible with proton therapy

  11. {sup 99m}Tc generators for clinical use based on zirconium molybdate gel and (n, gamma) produced {sup 99}Mo: Indian experience in the development and deployment of indigenous technology and processing facilities

    SciTech Connect (OSTI)

    Saraswathy, P.; Dey, A.C.; Sarkar, S.K.; Kothalkar, C.; Naskar, P.; Arjun, G.; Arora, S.S.; Kohli, A.K.; Meera, V.; Venugopal, V.; Ramamoorthy, N.

    2008-07-15

    The Indian pursuit of gel generator technology for {sup 99m}Tc was driven mainly by three considerations, namely, (i) well-established and ease of reliable production of (n, gamma)-based {sup 99}Mo in several tens of GBq quantities in the research reactors in Trombay/Mumbai, India, (ii) need for relatively low-cost alternate technology to replace the solvent (MEK) extraction generator system in use in India since 1970s and (iii) minimize dependency on weekly import of fission-produced {sup 99}Mo raw material required for alumina column generator. Extensive investigations on process standardisation for zirconium molybdate gel (ZMG) led to a steady progress, achieved both in terms of process technology and final performance of {sup 99m}Tc gel generators. The {sup 99m}Tc final product purity from the Indian gel system was comparable to that obtained from the gold-standard alumina column generators. Based on the feasibility established for reliable small-scale production, as well as satisfactory clinical experience with a number of gel generators used in collaborating hospital radiopharmacies, full-fledged mechanised processing facilities for handling up to 150 g of ZMG were set up. The indigenous design and development included setting up of shielded plant facilities with pneumatic-driven as well as manual controls and special gadgets such as, microwave heating of the zirconium molybdate cake, dispenser for gel granules, loading of gel columns into pre-assembled generator housing etc. Formal review of the safety features was carried out by the regulatory body and stage-wise clearance for processing low and medium level {sup 99}Mo activity was granted. Starting from around 70 GBq {sup 99}Mo handling, the processing facilities have since been successfully operated at a level of 740 GBq {sup 99}Mo, twice a month. In all 18 batches of gel have been processed and 156 generators produced. The individual generator capacity was 15 to 30 GBq with an elution yield of nearly 75

  12. Systematic investigation of electronic structure in BEDT-TTF based organic superconductors with Tc above 10 K; [kappa]-(BEDT-TTF)[sub 2]X (X = Cu(NCS)[sub 2], Cu[N(CN)[sub 2

    SciTech Connect (OSTI)

    Nakamura, Toshikazu; Nobutoki, Tomoko; Miyamoto, Masao; Tsubokura, Yuichi; Tsuchiya, Ryota; Takahashi, Toshihiro ); Kanoda, Kazushi ); Saito, Gunzi )

    1994-06-01

    The electronic structure of the title superconductors has been investigated by electrical resistivity, complex susceptibility, and electron paramagnetic resonance (EPR) measurements. The superconducting properties (pressure dependence of Tc, magnetic penetration depth, upper critical field, and so on) of these three salts are similar to each other, while transport properties in the normal state have shown a large variety in the temperature dependence. In order to clarify the electronic structure in the normal state, the EPR parameters, the spin susceptibility ([Chi][sub spin]), and the linewidth ([Delta]H[sub pp]), are compared. An anomalous temperature dependence of the g-value has been observed below 150 K in the Cu(NCS)[sub 2] and Cu(CN)[N(CN)[sub 2

  13. TC&WM EIS Scoping

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

    information, please call the Tank Closure & Waste Management EIS Info Line at 888-829-6347 A Citizen's Guide Background A January 9, 2006, legal settlement requires USDOE to prepare the Tank Closure and Waste Management Environmental Impact Statement for the Hanford Site, Richland, Washington. USDOE intends for the EIS to provide a comprehensive and integrated look at near-term waste management and tank waste cleanup actions at Hanford. What are the key points of the settlement? * Expand the

  14. Electromagnetic behavior of high-{Tc} superconductors

    SciTech Connect (OSTI)

    Ma, J.G.; Wolff, I.

    1996-05-01

    Using a new proposed model, the electromagnetic behavior of high-temperature superconductors (HTSs) is discussed. It indicates that the real part of the complex conductivity of HTSs is dependent on the driving frequency, and the simulated results agree well with measured data in literature. Nonlinear surface resistances dependence on an external magnetic field are also simulated and compared with experimental results.

  15. Rapid formation of the Bi{sub 2{minus}x}Pb{sub x}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub y} high {Tc}-phase, using spray-dried nitrate precursor powders

    SciTech Connect (OSTI)

    Van Driessche, I.; Mouton, R.; Hoste, S.

    1996-08-01

    This study describes the use of spray-dried nitrate precursor powders in the synthesis of Bi-2223 high {Tc}-superconductors. The decomposition of the precursor powder is studied using TGA/DTA, XRD, IR, and nitrogen analyses. The particle size is determined using SEM. The low decomposition temperature of the nitrates ({approximately}600 C) and the small particle size of the spray dried powder ({approximately}3{center_dot}10{sup {minus}6} m), resulting in a lowering of the calcination temperature and a shortening of the sinter time, enabled the authors to synthesize a > 96% pure Bi-2223 phase (from XRD peak intensities) after a thermal process of 5h at 650 C and 60 h at 855 C.

  16. TC&WM EIS doc.pdf

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

  17. High Temperature Irradiation Resistant Thermocouple (HTIR-TC)

    SciTech Connect (OSTI)

    2011-01-01

    INL researchers have created a new thermocouple that can resist high temperature and radiation. This device will improve safety and reduce costs associated with unit failures. Learn more about INL research at http://www.facebook.com/idahonationallaboratory

  18. Response of High-Tc Superconductor Metamaterials to High Intensity...

    Office of Scientific and Technical Information (OSTI)

    Resource Relation: Conference: PECS-X: 10th International Symposium on Photonic and Electromagnetic Crystal Structures ; 2012-06-03 - 2012-06-08 ; Santa Fe, New Mexico, United ...

  19. LD Vehicles AFDC 11 25 13 TC.xlsx

    Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

    Model Year 2014: Alternative Fuel and Advanced Technology Vehicles 1 (Updated 11252013) MY FuelPowertrain Type Make Model Vehicle Type Engine SizeCylinders Transmission...

  20. Tc with AsqTad and p4rhmc

    SciTech Connect (OSTI)

    Soltz, R; Vranas, P; Gupta, R

    2007-06-20

    We present the ongoing analysis of Lattice Quantum Chromodynamics runs on the LLNL BG/L supercomputer. This installment includes the analysis of 12,000 trajectories from the MILC AsqTad code on a 32{sup 3} x 8 lattice and the time histories from the plaquette and {psi} - bar{psi} trajectories from the p4rhmc code.

  1. Universal Charge Order in the High-Tc Superconductors | Stanford...

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

    such as heavy-fermion materials and copper-oxide based superconductors, by the use ... (BCS) theory of superconductivity are obtained in some copper-oxide (cuprate) materials. ...

  2. Pseudogaps, Polarons, and the Mystery of High-Tc Superconductivity

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

    such an explanation would not only answer a foundational question in modern solid-state physics, but it could provide more precise hints on where to search for the elusive...

  3. Bounding the Pseudogap in Cuprate High-TC Superconductors (Technical...

    Office of Scientific and Technical Information (OSTI)

    A paper copy of this document is also available for sale to the public from the National Technical Information Service, Springfield, VA at www.ntis.gov. Authors: McDonald, Ross ...

  4. Response of High-Tc Superconductor Metamaterials to High Intensity...

    Office of Scientific and Technical Information (OSTI)

    2 ; Singh, Ranjan 1 ; Yan, Li 3 ; Jia, Quanxi 1 ; Trugman, Stuart A. 1 ; Taylor, Antoinette J. 1 ; Nelson, Keith A. 2 ; Chen, Hou-Tong 1 + Show Author ...

  5. Response of High-Tc Superconductor Metamaterials to High Intensity...

    Office of Scientific and Technical Information (OSTI)

    Hao 3 ; Xiong, Jie 3 ; Yan, Li 3 ; Jia, Quanxi 1 ; Trugman, Stuart A. 1 ; Taylor, Antoinette J. 1 ; Nelson, Keith A. 2 ; Chen, Houtong 1 + Show Author ...

  6. High Temperature Irradiation Resistant Thermocouple (HTIR-TC)

    ScienceCinema (OSTI)

    None

    2013-05-28

    INL researchers have created a new thermocouple that can resist high temperature and radiation. This device will improve safety and reduce costs associated with unit failures. Learn more about INL research at http://www.facebook.com/idahonationallaboratory

  7. High Tc YBCO superconductor deposited on biaxially textured Ni substrate

    DOE Patents [OSTI]

    Budai, John D.; Christen, David K.; Goyal, Amit; He, Qing; Kroeger, Donald M.; Lee, Dominic F.; List, III, Frederick A.; Norton, David P.; Paranthaman, Mariappan; Sales, Brian C.; Specht, Eliot D.

    1999-01-01

    A superconducting article includes a biaxially-textured Ni substrate, and epitaxial buffer layers of Pd (optional), CeO.sub.2 and YSZ, and a top layer of in-plane aligned, c-axis oriented YBCO having a critical current density (J.sub.c) in the range of at least 100,000 A/cm.sup.2 at 77 K.

  8. Melt-spin processing of high {Tc} oxide superconductors

    SciTech Connect (OSTI)

    Folkerts, T.J.; Wu, Hengning; Yoo, S.I.; Merkle, B.D.; Arrasmith, S.R.; Dennis, K.W.; Kramer, M.J.; McCallum, R.W.

    1993-10-01

    Containerless techniques offer distinct advantages for the melt processing of oxide superconductors. The majority of these materials form liquids which are highly reactive with standard crucible materials such as Al{sub 2}O{sub 3} and Pt, resulting in non-negligible contamination. We have developed a containerless melt-spin processing technique where in 50--400 {mu}m particles of REBa{sub 2}Cu{sub 3}O{sub 7-x} high temperature oxide superconductors are melted in free fall through a vertical tube furnace and quenched onto a copper wheel. Previously this method has been successful in producing glasses of NdBa{sub 2}Cu{sub 3}O{sub 7-x} and GdBa{sub 2}Cu{sub 3}O{sub 7-x}. In this report we discuss the results for both stoichiometric and non-stoichiometric YBa{sub 2}Cu{sub 3}O{sub 7-x} (Y123). Thermal, microstructural, and superconducting characterization of both the as-quenched and the annealed materials will be presented.

  9. Response of High-Tc Superconductor Metamaterials to High Intensity...

    Office of Scientific and Technical Information (OSTI)

    DOE Contract Number: AC52-06NA25396 Resource Type: Conference Resource Relation: Conference: SPIE Optics+Photonics ; 2012-08-12 - 2012-08-16 ; San Diego, California, United States ...

  10. Response of High-Tc Superconductor Metamaterials to High Intensity...

    Office of Scientific and Technical Information (OSTI)

    Laboratory (LANL) LDRD United States 2012-08-13 English Conference Conference: SPIE Optics+Photonics ; 2012-08-12 - 2012-08-16 ; San Diego, California, United States Medium: ED...

  11. Strength and flexibility of bulk high-{Tc} superconductors

    SciTech Connect (OSTI)

    Goretta, K.C.; Jiang, M.; Kupperman, D.S.; Lanagan, M.T.; Singh, J.P.; Vasanthamohan, N.; Hinks, D.G.; Mitchell, J.F.; Richardson, J.W. Jr.

    1996-08-01

    Strength, fracture toughness, and elastic modulus data have been gathered for bulk high-temperature superconductors, commercial 99.9% Ag, and a 1.2 at.% Mg/Ag alloy. These data have been used to calculate fracture strains for bulk conductors. The calculations indicate that the superconducting cores of clad tapes should begin to fracture at strains below 0.2%. In addition, residual strains in Ag-clad (Bi,Pb){sub 2}Sr{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} tapes have been measured by neutron diffraction. An explanation is offered for why many tapes appear to be able to tolerate large strains before exhibiting a reduction in current transport.

  12. EPRI-TC-80-907-23 DISCLAIMER

    Office of Scientific and Technical Information (OSTI)

    ... water almost six times as much heat would have to be disposed of as would be required in a coal or oil fired plant of the same size operating at high temperature and pressure. ...

  13. Low-loss, high-speed, high-{Tc} superconducting bearings

    DOE Patents [OSTI]

    Hull, J.R.; Mulcahy, T.M.; Uherka, K.L.

    1997-06-24

    A flywheel energy storage device is disclosed including an iron structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet. The stationary permanent magnet levitates the iron structure while the superconductor structure can stabilize the rotating iron structure. 15 figs.

  14. Low-loss, high-speed, high-{Tc} superconducting bearings

    DOE Patents [OSTI]

    Hull, J.R.; Mulcahy, T.M.; Uherka, K.L.

    1996-07-30

    A flywheel energy storage device is disclosed including an iron structure disposed for rotation adjacent a stationary superconductor material structure and a stationary permanent magnet. The stationary permanent magnet levitates the iron structure while the superconductor structure can stabilize and levitate the rotating iron structure. 15 figs.

  15. Compensated electron and hole pickets in an underdoped high Tc superconductor

    SciTech Connect (OSTI)

    Harrison, Neil; Altarawneh, Moaz M; Mielke, Charles H; Sebastian, Suchitra E; Goddard, P A; Liang, Ruixing; Bonn, D A; Hardy, W N; Andersen, O K; Lonzarich, G G

    2010-01-01

    Important to the question of high temperature superconductivity is whether bound fermionic pairs with zero or finite momentum - exhibiting bosonic physics - are involved. Here we use angle-dependent magnetic quantum oscillation measurements in underdoped YBa{sub 2}Cu{sub 3}O{sub 6+x} to reveal two significantly differently corrugated small sections of Fermi surface, identifying them as comprising opposite carriers located at different locations of the Brillouin zone. The surprising finding that these disproportionately heavy small pockets are equal in size indicates they are prone to a finite momentum excitonic insulator instability. We discuss the possibility that reducing the doping drives YBa{sub 2}Cu{sub 3}O{sub 6+x} closer to an instability of this nature, its ultimate realization occuring at the metal-insulator quantum critical point, accompanied by a potential enhancement of superconducting transition temperatures.

  16. Shielded high-TC BSCCO tapes or wires for high field applications

    DOE Patents [OSTI]

    Balachandran, Uthamalingam; Lelovic, Milan; Eror, Nicholas G.

    2001-01-01

    A composite superconductor having an interior component of multiple filaments of superconducting Bi-2223 sheathed in a Ag or Ag alloy material, and a RE, TI or Hg based superconductor surrounding the interior component.

  17. Shielded high-Tc bscco tapes or wires for high field applications

    DOE Patents [OSTI]

    Balachandran, Uthamalingam; Lelovic, Milan; Eror, Nicholas G.

    2002-01-01

    A composite superconductor having an interior component of multiple filaments of superconducting Bi-2223 sheathed in a Ag or Ag alloy material, and a RE, TI or Hg based superconductor surrounding the interior component.

  18. DOE Tour of Zero: The Montlake Modern by TC Legend Homes | Department...

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

    7 of 17 The home is equipped with a high-capture filtered fresh-air intake for passive makeup air; the air intake has a fan that is electronically controlled to operate when the...

  19. Irradiation response of commercial, high-Tc superconducting tapes: Electromagnetic transport properties

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

    Gapud, A. A.; Greenwood, N. T.; Alexander, J. A.; Khan, A.; Leonard, K. J.; Aytug, T.; List III, F. A.; Rupich, M. W.; Zhang, Y.

    2015-07-01

    Effects of low dose irradiation on the electrical transport current properties of commercially available high-temperature superconducting, coated-conductor tapes were investigated, in view of potential applications in the irradiative environment of fusion reactors. Three different tapes, each with unique as-grown flux-pinning structures, were irradiated with Au and Ni ions at energies that provide a range of damage effects, with accumulated damage levels near that expected for conductors in a fusion reactor environment. Measurements using transport current determined the pre- and post-irradiation resistivity, critical current density, and pinning force density, yielding critical temperatures, irreversibility lines, and inferred vortex creep rates. Results showmore » that at the irradiation damage levels tested, any detriment to as-grown pre-irradiation properties is modest; indeed in one case already-superior pinning forces are enhanced, leading to higher critical currents.« less

  20. Intra-unit-cell Electronic Nematicity of the High-Tc Copper-oxide Pseudogap States

    SciTech Connect (OSTI)

    Davis, J.C.; Lawler, M.J.; Fujita, K.; Lee, J.; Schmidt, A.R.; Kohsaka, Y.; Kim, C.K.; Eisaki, H.; Uchida, S.; Sethna, J.P.; Kim, E.-A.

    2010-07-15

    In the high-transition-temperature (high-T{sub c}) superconductors the pseudogap phase becomes predominant when the density of doped holes is reduced. Within this phase it has been unclear which electronic symmetries (if any) are broken, what the identity of any associated order parameter might be, and which microscopic electronic degrees of freedom are active. Here we report the determination of a quantitative order parameter representing intra-unit-cell nematicity: the breaking of rotational symmetry by the electronic structure within each CuO{sub 2} unit cell. We analyse spectroscopic-imaging scanning tunnelling microscope images of the intra-unit-cell states in underdoped Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} and, using two independent evaluation techniques, find evidence for electronic nematicity of the states close to the pseudogap energy. Moreover, we demonstrate directly that these phenomena arise from electronic differences at the two oxygen sites within each unit cell. If the characteristics of the pseudogap seen here and by other techniques all have the same microscopic origin, this phase involves weak magnetic states at the O sites that break 90{sup o}-rotational symmetry within every CuO{sub 2} unit cell.

  1. Materials Data on U2Si5Tc3 (SG:128) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    2015-03-07

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  2. DOE Zero Energy Ready Home Case Study: TC Legend Homes — Cedarwood, Bellingham, WA

    SciTech Connect (OSTI)

    none,

    2014-09-01

    This house was the Grand Winner in the Affordable Builder category of the 2014 Housing Innovation Awards, and has 6-inch SIP walls, a 10-inch structural insulated panel roof, and insulating concrete forms foundation walls with R-20 high-density rigid EPS foam under the slab.A single ductless heat pump heats and cools the home, which also gets passive solar heating from south-facing triple-pane windows that heat a concrete slab floor plus a connected greenhouse.

  3. DOE Zero Energy Ready Home Case Study: TC Legend Homes, Seattle, Washington

    SciTech Connect (OSTI)

    none,

    2013-09-01

    This house incorporates slab-on-grade, EPS roof, and radiant heating with an air-to-water heat pump that also preheats domestic hot water. Without counting in the solar panels, the home earns a home energy rating system (HERS) score of 37, with projected utility bills of about $740 a year. With the 6.4-kW photovoltaic power system installed on the roof, the home’s HERS scores drops to -1 and utility bills for the all-electric home drop to zero. This home was awarded a 2013 Housing Innovation Award in the affordable builder category.

  4. Reactive nanophase oxide additions to melt-processed high-{Tc} superconductors

    SciTech Connect (OSTI)

    Goretta, K.C.; Brandel, B.P.; Lanagan, M.T.; Hu, J.; Miller, D.J.; Sengupta, S.; Parker, J.C.; Ali, M.N.; Chen, Nan

    1994-10-01

    Nanophase TiO{sub 2} and Al{sub 2}O{sub 3} powders were synthesized by a vapor-phase process and mechanically mixed with stoichiometric YBa{sub 2}Cu{sub 3}O{sub x} and TlBa{sub 2}Ca{sub 2}Cu{sub 3}O{sub x} powders in 20 mole % concentrations. Pellets produced from powders with and without nanophase oxides were heated in air or O{sub 2} above the peritectic melt temperature and slow-cooled. At 4.2 K, the intragranular critical current density (J{sub c}) increased dramatically with the oxide additions. At 35--50 K, effects of the oxide additions were positive, but less pronounced. At 77 K, the additions decreased J{sub c}, probably because of inducing a depresion of the transition temperature.

  5. DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham...

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

    An exhaust fan provides ventilation by drawing in tempered outside air through a 100-foot "earth tube" buried 2-feet underground. DOEZEHTCLegendCedarwood09-20-14.pdf (1.41 MB) ...

  6. DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham, WA

    Broader source: Energy.gov [DOE]

    Case study of a DOE Zero Energy Ready home in Bellingham, WA, that achieves HERS 43 without PV or HERS 13 with 3.2 kW of PV.

  7. DOE Zero Energy Ready Home Case Study: TC Legend, Seattle, WA, Custom Home

    Broader source: Energy.gov [DOE]

    Case study of a DOE Zero Energy Ready Home in Seattle, WA, that scored HERS 37 without PV, HERS -1 with PV. This 1,915-square-foot custom home has SIP walls and roof, R-20 XPS under the slab, triple-pane windows, an air to water heat pump for radiant heat, and balanced ventilation with timer-controlled fans to bring in and exhaust air.

  8. DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham Power House, Bellingham, WA

    Broader source: Energy.gov [DOE]

    Case study of a DOE 2015 Housing Innovation Award winning custom home in the marine climate that got HERS 34 without PV or HERS -12 with PV, with 6” SIP walls and 10” SIP roof; R-28 ICF around slab, R-20 rigid foam under slab; radiant floor heat and passive design; air-to-water heat pump COP 4.4; HRV; earth tube ventilation; triple-pane windows, 100% LED.

  9. HAB_Ecology_Letter_on_Draft_TC-WM-EIS043010.pdf

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

  10. WP-96/TR-96 & TC-96 Power and Transmission Rate Case (rates/ratecases...

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

    Of Decision (WP-96 ROD) Final Studies And Documentation (WP-96-FS) Loads and Resources Revenue Requirement Segmentation Marginal Cost Analysis Wholesale Power Rate Development...

  11. Phonon characteristics of high {Tc} superconductors from neutron Doppler broadening measurements

    SciTech Connect (OSTI)

    Trela, W.J.; Kwei, G.H.; Lynn, J.E.; Meggers, K.

    1994-12-01

    Statistical information on the phonon frequency spectrum of materials can be measured by neutron transmission techniques if they contain nuclei with low energy resonances, narrow enough to be Doppler-broadened, in their neutron cross sections. The authors have carried out some measurements using this technique for materials of the lanthanum barium cuprate class, La{sub 2{minus}x}Ba{sub x}CuO{sub 4}. Two samples with slightly different concentrations of oxygen, one being superconductive, the other not, were examined. Pure lanthanum cuprate was also measured. Lanthanum, barium and copper all have relatively low energy narrow resonances. Thus it should be possible to detect differences in the phonons carried by different kinds of atom in the lattice. Neutron cross section measurements have been made with high energy resolution and statistical precision on the 59m flight path of LANSCE, the pulsed spallation neutron source at Los Alamos National Laboratory. Measurements on all three materials were made over a range of temperatures from 15K to 300K, with small steps through the critical temperature region near 27K. No significant changes in the mean phonon energy of the lanthanum atoms were observed near the critical temperature of the super-conducting material. It appears however that the mean phonon energy of lanthanum in the superconductor is considerably higher than that in the non-superconductors. The samples used in this series of experiments were too thin in barium and copper to determine anything significant about their phonon spectra.

  12. Materials Data on Tc2O7 (SG:61) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2014-11-02

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  13. Lessons learned from substation predictive maintenance project, TC project {number_sign}7014. Final report

    SciTech Connect (OSTI)

    Geisecke, J.; Spencer, G.; Richardson, F.

    1998-12-01

    The EPRI Maintenance and Diagnostics Center, through a tailored collaboration effort with 10 utilities, developed a Substation Predictive Maintenance Program (SPDM). The objective of the program was to reduce Operation and Maintenance (O and M) costs by applying predictive/condition based maintenance practices to energized substation equipment. This report presents a summary of the project including: how new and existing diagnostic technologies and equipment were evaluated and utilized; how information was gathered in program cost justification and savings and specific work procedures and program administrative aids for a SPDM process. The program was effective in implementing a preventive or condition based maintenance process for participating utilities--enhancing the prioritization or work, redirecting maintenance activity and reducing costs. This document can serve as an implementation guide with lessons learned for substation predictive maintenance processes or to compare and contrast programs currently in place.

  14. Materials Data on Co2TcO4 (SG:74) by Materials Project

    DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

    Kristin Persson

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  15. Materials Data on Co2TcO4 (SG:74) by Materials Project

    SciTech Connect (OSTI)

    Kristin Persson

    2015-05-16

    Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations

  16. DOE Zero Energy Ready Home Case Study 2014: TC Legend Homes, Montlake Modern, Seattle, WA

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

    Montlake Modern Seattle, WA DOE ZERO ENERGY READY HOME(tm) CASE STUDY The U.S. Department of Energy invites home builders across the country to meet the extraordinary levels of excellence and quality specified in DOE's Zero Energy Ready Home program (formerly known as Challenge Home). Every DOE Zero Energy Ready Home starts with ENERGY STAR Certified Homes Version 3.0 for an energy-efficient home built on a solid foundation of building science research. Advanced technologies are designed in to

  17. DOE Zero Ready Home Case Study: TC Legend Homes, Cedarwood, Bellingham, WA

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

    Cedarwood Bellingham, WA DOE ZERO ENERGY READY HOME(tm) The U.S. Department of Energy invites home builders across the country to meet the extraordinary levels of excellence and quality specified in DOE's Zero Energy Ready Home program (formerly known as Challenge Home). Every DOE Zero Energy Ready Home starts with ENERGY STAR Certified Homes Version 3.0 for an energy-efficient home built on a solid foundation of building science research. Advanced technologies are designed in to give you

  18. Bearing design for flywheel energy storage using high-TC superconductors

    DOE Patents [OSTI]

    Hull, John R.; Mulcahy, Thomas M.

    2000-01-01

    A high temperature superconductor material bearing system (38) This system (38) includes a rotor (50) having a ring permanent magnet (60), a plurality of permanent magnets (16, 20 and 70) for interacting to generate levitation forces for the system (38). This group of magnets are a push/pull bearing (75). A high temperature superconductor structure (30) interacts with the ting permanent magnet (60) to provide stabilizing forces for the system (38).

  19. Fate of Tc99 at WTP and Current Work on Capture

    Office of Environmental Management (EM)

    as seen at the DOE EM Construction Project Review November 2010 Bechtel National, Inc. Albert A. Kruger, DOE-WED Glass Scientist John Olson, BNI Manager, Process Engineering Design...

  20. Reductive Sequestration Of Pertechnetate (99TcO4-) By Nano Zerovalent...

    Office of Scientific and Technical Information (OSTI)

    Authors: Fan, Dimin ; Anitori, Roberto ; Tebo, Bradley M. ; Tratnyek, Paul G. ; Lezama Pacheco, Juan S. ; Kukkadapu, Ravi K. ; Engelhard, Mark H. ; Bowden, Mark E. ; Kovarik, Libor ...

  1. T-692: VMware vFabric tc Server Lets Remote Users Login Using...

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

    A remote user can login using an obfuscated version of their password. PLATFORM: ... user can use the password in obfuscated form (or in plain text form) to authenticate. ...

  2. Giant flux creep through the surface barriers and the irreversibility line in high-{Tc} superconductors

    SciTech Connect (OSTI)

    Burlachkov, L.; Geshkenbein, V.B. ||; Koshelev, A.E. |; Larkin, A.I. |; Vinokur, V.M.

    1994-05-01

    Magnetic flux relaxation over the surface barrier in high temperature superconductors are investigated Vortex dynamics controlled by the penetration both of pancake vortices and vortex lines are discussed. The penetration field H{sub p} for pancakes decay is exponentially with temperature. The size of the magnetization loop is determined by the decay of H{sub p} during the process of relaxation, but its shape remains unchanged. The irreversibility line associated with the pancake penetration is given by H{sub irr} {proportional_to} exp(- 2T/T{sub o}), and may lie both above and below the melting line.

  3. Irradiation of commercial, high-Tc superconducting tape for potential fusion applications: electromagnetic transport properties

    SciTech Connect (OSTI)

    Aytug, Tolga [ORNL; Gapud, Albert A. [University of South Alabama, Mobile; List III, Frederick Alyious [ORNL; Leonard, Keith J [ORNL; Rupich, Marty [American Superconductor Corporation, Westborough, MA; Zhang, Yanwen [ORNL; Greenwood, N T [University of South Alabama, Mobile; Alexander, J A [University of South Alabama, Mobile; Khan, A [University of South Alabama, Mobile

    2015-01-01

    Effects of low dose irradiation on the electrical transport current properties of commercially available high-temperature superconducting, coated-conductor tapes were investigated, in view of potential applications in the irradiative environment of fusion reactors. Three different tapes, each with unique as-grown flux-pinning structures, were irradiated with Au and Ni ions at energies that provide a range of damage effects, with accumulated damage levels near that expected for conductors in a fusion reactor environment. Measurements using transport current determined the pre- and post-irradiation resistivity, critical current density, and pinning force density, yielding critical temperatures, irreversibility lines, and inferred vortex creep rates. Results show that at the irradiation damage levels tested, any detriment to as-grown pre-irradiation properties is modest; indeed in one case already-superior pinning forces are enhanced, leading to higher critical currents.

  4. High-Risk Components Removed from K-25’s Tc-99 Area

    Broader source: Energy.gov [DOE]

    Oak Ridge's EM program removes one of the highest risk components remaining in K-25 building with the successful crane removal of five components known as NaF traps.

  5. DOE ZERH Case Study: TC Legend Homes, Bellingham Power House, Bellingham, WA

    SciTech Connect (OSTI)

    none,

    2015-09-01

    Case study of a DOE 2015 Housing Innovation Award winning custom home in the marine climate that got HERS 34 without PV or HERS -12 with PV, with 6” SIP walls and 10” SIP roof; R-28 ICF around slab, R-20 rigid foam under slab; radiant floor heat and passive design; air-to-water heat pump COP 4.4; HRV; earth tube ventilation; triple-pane windows, 100% LED.

  6. HIA 2015 DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham Power House, Bellingham, WA

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

    Bellingham Power House Bellingham, WA DOE ZERO ENERGY READY HOME(tm) The U.S. Department of Energy invites home builders across the country to meet the extraordinary levels of excellence and quality specified in DOE's Zero Energy Ready Home program (formerly known as Challenge Home). Every DOE Zero Energy Ready Home starts with ENERGY STAR Certified Homes Version 3.0 for an energy-efficient home built on a solid foundation of building science research. Advanced technologies are designed in to

  7. Improvement of magnetic shielding effects: The superposition of a double-magnetic cylinder over a high-Tc superconducting cylinder

    SciTech Connect (OSTI)

    Ohyama, Takashi; Minemoto, Takumi ); Itoh, Mineo ); Hoshino, Kazutomo )

    1993-11-01

    Improvement of magnetic shielding was achieved by superimposing a double-magnetic cylinder over a YBCO (Y-Ba-Cu-0) cylinder. The value of the magnetic shielded field for the superimposed cylinder was 47 times larger than that of the YBCO cylinder. The magnetic shielded field obtained when superimposing a soft iron single-cylinder over a YBCO cylinder was analyzed using the Bean, Wills, and Mager models, with an important criterion being derived for designing an effective shield of the chamber.

  8. Analytical description of the Jc(B) dependence of high Tc superconducting thin films in small perpendicular fields

    SciTech Connect (OSTI)

    Hanisch, Jens; Grilli, Francesco; Holzapfel, Bernhard

    2008-01-01

    The field dependencies of J{sub c} of YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} based high-temperature superconducting thin films are measured in fine steps for B||c in a wide temperature range. It is found that J{sub c}(B) of all samples can be described by a generalization of Kim's critical state model with two additional variables. At very low fields, a plateau of constant J{sub c} is observed, for which two possible reasons are discussed - self-field effects and a strong single-vortex pinning mechanism. Around 1 T we identified a small 'peak' which may be responsible for ultralow experimental {alpha} values in high-quality samples.

  9. Thallium 2223 high Tc superconductor in a silver matrix and its magnetic shielding, hermal cycle and time aging properties

    SciTech Connect (OSTI)

    Fei, X.; He, W.S.; Havenhill, A.

    1994-12-31

    Superconducting Tl{sub 2}Ba{sub 2}Ca{sub 2}Cu{sub 3}O{sub 10} (Tl2223) was ground to powder. Mixture with silver powder (0--80% weight) and press to desired shape. After proper annealing, one can get good silver-content Tl2223 bulk superconductor. It is time-stable and has good superconducting property as same as pure Tl2223. It also has better mechanical property and far better thermal cycle property than pure Tl2223.

  10. Synthesis of high {Tc} superconducting coatings and patterns by melt writing and oxidation of metallic precursor alloys

    DOE Patents [OSTI]

    Gao, W.; Vander Sande, J.B.

    1998-07-28

    A method is provided for fabrication of superconducting oxides and superconducting oxide composites and for joining superconductors to other materials. A coating of a molten alloy containing the metallic elements of the oxide is applied to a substrate surface and oxidized to form the superconducting oxide. A material can be contacted to the molten alloy which is subsequently oxidized joining the material to the resulting superconducting oxide coating. Substrates of varied composition and shape can be coated or joined by this method. 5 figs.

  11. “Nodal Gap” induced by the incommensurate diagonal spin density modulation in underdoped high- Tc superconductors

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

    Zhou, Tao; Gao, Yi; Zhu, Jian -Xin

    2015-03-07

    Recenmore » tly it was revealed that the whole Fermi surface is fully gapped for several families of underdoped cuprates. The existence of the finite energy gap along the d-wave nodal lines (nodal gap) contrasts the common understanding of the d-wave pairing symmetry, which challenges the present theories for the high-Tcsuperconductors. Here we propose that the incommensurate diagonal spin-density-wave order can account for the above experimental observation. The Fermi surface and the local density of states are also studied. Our results are in good agreement with many important experiments in high-Tcsuperconductors.« less

  12. Thermodynamic and nonstoichiometric behavior of promising Hi-Tc cuprate systems via EMF measurements : a short review.

    SciTech Connect (OSTI)

    Tetenbaum, M.

    1999-02-24

    Electromotive force (EMF) measurements of oxygen fugacities as a function of stoichiometry have been made on the YBa{sub 2}Cu{sub 3}O{sub x}, GdBa{sub 2}Cu{sub 3}O{sub x}, NdBa{sub 2}Cu{sub 3}O{sub x} and bismuth cuprate systems in the temperature range {approximately}400-750 C by means of an oxygen titration technique with an yttria-stabilized zirconia electrolyte. The shapes of the 400 C isotherms as a function of oxygen stoichiometry for the Gd and Nd cuprate systems suggest the presence of miscibility gaps at values of x that are higher than those in the YBa{sub 2}Cu{sub 3}O{sub x} system. For a given oxygen stoichiometry, oxygen partial pressures above GdBa{sub 2}Cu{sub 3}O{sub x} and NdBa{sub 2}Cu{sub 3}O{sub x} are higher (above x=6.5) than that for the promising YBa{sub 2}Cu{sub 3}O{sub x} system. A thermodynamic assessment and intercomparison of our partial pressure measurements with the results of related measurements will be presented.

  13. HYBRID SULFUR ELECTROLYZER DEVELOPMENT, NHI WORK PACKAGE N-SR07TC0301, FY07 FIRST QUARTER REPORT

    SciTech Connect (OSTI)

    Summers, W

    2006-12-20

    The proof of concept of SO2 electrolysis for the hybrid sulfur (HyS) process is the second priority research target of the DOE Nuclear Hydrogen Initiative's thermochemical program for FY07. The proof of concept of the liquid-phase option must be demonstrated at the single cell level for an extended run times (>100 hours). The rate of development of HyS will depend on the identification of a promising membrane or an alternative means for controlling sulfur formation. Once successful long-duration operation has been demonstrated, SRNL will develop a multi-cell stack that can be connected to the H2SO4 decomposer being developed by SNL for the S-I ILS for a Hybrid Sulfur Integrated Laboratory-Scale Experiment during FY 2008. During the first quarter of FY07, SRNL continued the component development and membrane development activities with the goal of identifying and characterizing improved electrodes, electrocatalysts, membranes and MEA configurations which could then be tested at larger scale in the SDE test facility. A modified glass cell was fabricated to allow measurements of sulfur dioxide (SO2) transport across membrane samples at elevated temperatures (up to 70 C). This testing also includes evaluating SO2 transport in different sulfuric acid concentrations (30-70 wt%). A new potentiostat/frequency analyzer was installed for determining ionic conductivity of membranes. This instrument enhances our capabilities to characterize membrane, electrocatalyst and MEA properties and performance. Continuing work from FY06, evaluations were preformed on various commercial and experimental membranes and electrocatalyst materials for the SDE. Several different types of commercially-available membranes were analyzed for sulfur dioxide transport as a function of acid strength including perfluorinated sulfonic acid (PFSA), sulfonated polyetherketone-ketone, and poly-benzimidazole (PBI) membranes. Experimental membranes from the sulfonated diels-alder polyphenylenes (SDAPP) and modified Nafion{reg_sign} 117 were evaluated for SO{sub 2} transport as well. These membranes exhibited reduced transport coefficient for SO{sub 2} transport without the loss in ionic conductivity.

  14. HYBRID SULFUR ELECROLYZER DEVELOPMENT, NHI WORK PACKAGE N-SR07TC0301, FY08 FIRST QUARTER REPORT

    SciTech Connect (OSTI)

    Summers, W

    2007-12-20

    Hydrogen has been identified as a leading candidate to replace petroleum as part of the transition to a sustainable energy system, and major efforts are being conducted worldwide to develop the technologies and supporting activities required for this transition. In the United States, the federal research efforts are led by the U.S. Department of Energy (DOE). The U.S. DOE Hydrogen Program is an integrated inter-office program being conducted by the Office of Energy Efficiency and Renewable Energy, Office of Nuclear Energy (DOE-NE), Office of Fossil Energy and Office of Science. The primary objective of the DOE-NE Nuclear Hydrogen Initiative (NHI) is to develop the nuclear hydrogen production technologies necessary to produce hydrogen at a cost competitive with other alternative transportation fuels. The focus of the NHI is on thermochemical cycles and high temperature electrolysis. The Savannah River National Laboratory (SRNL) has been tasked with the primary responsibility to perform research and development in order to characterize, evaluate and develop the Hybrid Sulfur (HyS) thermochemical process. The HyS Process uses a sulfur dioxide depolarized electrolyzer (SDE) to split water and produce hydrogen. During FY05 and FY06, SRNL designed and conducted proof-of-concept testing for a SDE using a low temperature, PEM fuel cell-type design concept. The advantages of this design concept include high electrochemical efficiency and small footprint, characteristics that are crucial for successful implementation on a commercial scale. During FY07, SRNL extended the range of testing of the SDE to higher temperature and pressure, conducted a 100-hour longevity test, and designed and built a larger, multi-cell stack electrolyzer. The proof of concept of SO2 electrolysis for the HyS Process is a priority research target for the FY 2008 NHI Program. Technical options must be better defined and the challenges better understood. The current status of electrolyzer performance must be established by operation at elevated temperature (>90C) and pressure (>10 atmospheres) and during a long duration run (>100 hours). SRNL is pursuing the liquid-phase sulfur dioxide decoupled electrolyzer (SDE) option, which is the main focus of the NHI work. The rate of development of HyS will depend on the identification of a promising membrane or an alternative means for controlling sulfur formation at the cathode of the cell. SRNL will work with Sandia National Laboratory (SNL), universities, and industry to address this issue. Electrolyzers of larger size will be required as the process development proceeds, and SRNL will test a multi-cell stack that was built in FY 2007. Work will be initiated for a Hybrid Sulfur Integrated Laboratory-Scale (ILS) Experiment that will combine a SRNL electrolyzer with the sulfuric acid decomposer developed by SNL for the S-I ILS. A review will be held at mid-year, and if progress warrants, work will progress to the ILS level including ILS system design, electrolyzer fabrication and infrastructure development. Benchmarks to be considered include electrochemical efficiency, membrane durability, and minimization of SO2 crossover.

  15. Atomic scale studies of doped-hole distributions, self-organized electronic nano-domains, and electron-boson coupling in high Tc-cuprates

    SciTech Connect (OSTI)

    Davis, James C.

    2014-05-14

    Progress is reported in these areas (titles and abstracts of journal articles produced for the contract): Exotic Density Wave in Underdoped Cuprates; Varying the inter-atomic distances within individual crystal unit-­cells of cuprates; Truncated Momentum Space Electronic Structure of Underdoped Bi2Sr2CaCu2O8+δ; and, Visualizing Phase Fluctuating d-Wave Superconductivity in the Cuprate Pseudogap State.

  16. Preliminary results of Tc-99m Sulfur Colloid (SC) and glucoheptonate (GHP) surveillance of renal allografts (AG) on cyclosporin a (CSA) maintenance

    SciTech Connect (OSTI)

    George, F.A.; Brown, W.W.; Malone, J.D.; Naidu, R.; Carney, K.; Garvin, P.J.

    1985-05-01

    The potential nephro-toxicity of CSA complicates the therapeutic management of AG with unexplained reduced function. Seven living related donor (LRD) and 23 cadaver (C) AG maintained, at least initially, on CSA and low dose prednisone and functioning for at least 2 months were studied during a 10 month period; mean serum creatinine (Scr) was 1.5 mg/dl for LRD and 2.35 mg/dl for C AG recipients. A total of 12 biopsies were performed in 10 recipients (2 LRD, 10 C AG) for unexplained SCr levels above 3.0 mg/dl. SC-GHP surveillance was carried out in each recipient between 4 and 15 times. SC exam was analyzed by temporal quantitation (as previously reported) and GHP exam was evaluated visually for AG perfusion, uptake and excretion of GHP. Biopsies were examined with H and E and immunofluorescent staining. Results were compared to therapeutic outcome, subsequent biopsy or AG nephrectomy. In summary, the comparison of SC-GHP exam and biopsy diagnosis in 12 instances for the differential diagnosis of CSA toxicity versus AR demonstrated correct assessment by the SC-GHP exam 12/12. AG biopsy diagnosis was correct in 8/12 instances.

  17. Stability of U(VI)- and Tc(VII) reducing microbial communities to environmental perturbation: a thermodynamic network model and intermediate-scale experiments

    SciTech Connect (OSTI)

    McKinley, James P.; Liu, Chongxuan; Istok, Jack; Krumholz, Lee

    2006-06-01

    The project is a collaborative task with a larger project headed by Jack Istok at Oregon State University, which is conducted under the same title. The project was conceptualized as follows. A ''geochemical'' model of microbial communities was hypothesized, in which microbes were characterized as mineral species according to the chemical transformations they used for metabolic function. The iron-reducing bacteria, for example, would be represented by the iron reducing chemical reaction, including a specific electron donor, the fraction of the consumed donor used for biomass maintenance or growth, and a free energy for the reaction. The pseudomineral species would then be included in a standard geochemical model, and community succession could be calculated according to the thermodynamically favored microbially mediated reactions under progressive consumption of electron donors and receptors, and evolving geochemical conditions. The project includes relatively minor participation by the University of Oklahoma and Pacific Northwest National Laboratory, with the major component at OSU. The PNNL project was funded to provide assistance to Dr. Istok in formulating the appropriate modeling approach and geochemical constraints on the modeling effort.

  18. Matching field effects at tesla-level magnetic fields in critical current density in high-Tc superconductors containing self-assembled columnar defects

    SciTech Connect (OSTI)

    Sinclair, J.; Zuev, Yuri L; Cantoni, Claudia; Wee, Sung Hun; Varanasi, C. V.; Thompson, James R; Christen, David K

    2012-01-01

    We have investigated the superconductive transport properties of YBa2Cu3O7 films containing self-assembled columnar arrays of second phase SrZrO3 or BaSnO3 precipitates. A matching condition between columnar pinning sites (aligned at or near the c axis) and external magnetic flux, tilted with respect to them, is identified in the critical current JC.H/ data. The results for the material containing SrZrO3-based pins are analyzed within a simple intuitive model. At matching, the critical current is enhanced above the model prediction. In complementary contact-free investigations of BaSnO3-doped material, matching effects are observed over a wide range of temperatures in the field dependence of JC.H/. The deduced matching fields agree reasonably well with the densities of columnar pins directly observed by scanning electron microscopy.

  19. Spectroscopic Evidence for a High-Spin Br-Fe(IV)-Oxo Intermediate in the -Ketoglutarate-Dependent Halogenase CyTc3 From Streptomyces

    SciTech Connect (OSTI)

    Fujimori, D.Galonic; Barr, E.W.; Matthews, M.L.; Koch, G.M.; Yonce, J.R.; Walsh, C.T.; Bollinger, J.M., Jr.; Krebs, C.; Riggs-Gelasco, P.J.

    2009-06-01

    The complex of the mononuclear non-heme halogenase CytC3 from Streptomyces, Fe(II), {alpha}-ketoglutarate, bromide, and the substrate l-2-aminobutyryl-S-CytC2 reacts with O{sub 2} to form a reaction intermediate. Variable-field, freeze-quench Moessbauer spectroscopy reveals this intermediate to be a mixture of two high-spin Fe(IV) complexes in an approximate 3.7/1 ratio. Freeze-quench Fe K-edge X-ray absorption spectroscopy provides further insight into the structure of this intermediate. A short 1.62-{angstrom} interaction between the Fe and one of its ligands is attributed to the Fe(IV)-oxo group, and a 2.43-{angstrom} interaction is assigned to the Fe-Br interaction. A significantly longer Fe-Br separation (2.53 {angstrom}) is observed in the reactant complex, consistent with lower valency of the Fe in the reactant complex. This intermediate is the first example for a Br-Fe(IV)-oxo complex in a protein and provides evidence for a unifying mechanism for Fe(II) and {alpha}-ketoglutarate-dependent dioxygenases and halogenases.

  20. Commensurate antiferromagnetic excitations as a signature of the pseudogap in the tetragonal high-Tc cuprate HgBa2CuO4+δ

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

    Chan, M. K.; Dorow, C. J.; Mangin-Thro, L.; Tang, Y.; Ge, Y.; Veit, M. J.; Yu, G.; Zhao, X.; Christianson, A. D.; Park, J. T.; et al

    2016-03-04

    We report that antiferromagnetic correlations have been argued to be the cause of the d-wave superconductivity and the pseudogap phenomena exhibited by the cuprates. Although the antiferromagnetic response in the pseudogap state has been reported for a number of compounds, there exists no information for structurally simple HgBa2CuO4+δ. We report neutron-scattering results for HgBa2CuO4+δ (superconducting transition temperature Tc≈71 K, pseudogap temperature T*≈305 K) that demonstrate the absence of the two most prominent features of the magnetic excitation spectrum of the cuprates: the X-shaped ‘hourglass’ response and the resonance mode in the superconducting state. Instead, the response is Y-shaped, gapped andmore » significantly enhanced below T*, and hence a prominent signature of the pseudogap state.« less

  1. From Ions to Wires to the Grid: The Transformational Science of LANL Research in High-Tc Superconducting Tapes and Electric Power Applications

    ScienceCinema (OSTI)

    Marken, Ken [Superconductivity Technology Center, Los Alamos, New Mexico, United States

    2010-01-08

    The Department of Energy (DOE) Office of Electricity Delivery and Energy Reliability (OE) has been tasked to lead national efforts to modernize the electric grid, enhance security and reliability of the energy infrastructure, and facilitate recovery from disruptions to energy supplies. LANL has pioneered the development of coated conductors ? high-temperature superconducting (HTS) tapes ? which permit dramatically greater current densities than conventional copper cable, and enable new technologies to secure the national electric grid. Sustained world-class research from concept, demonstration, transfer, and ongoing industrial support has moved this idea from the laboratory to the commercial marketplace.

  2. Notices Disabled, 1401 S. Clark Street, Suite

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

    ... in the Final TC&WM EIS, for FFTF Decommissioning, DOE's preference is for Alternative ... Public Comments on the Final TC&WM EIS DOE received six letters regarding the Final TC&WM ...

  3. Oak Ridge Site Specific Advisory Board Monthly Meeting W W W

    Office of Environmental Management (EM)

    Ecology Corp. SEP - supplemental environmental project STP - site treatment plan SW - surface water SWSA - solid waste storage area Tc - technetium TC - time critical TDEC -...

  4. Browse by Discipline -- E-print Network Subject Pathways: Biotechnolog...

    Office of Scientific and Technical Information (OSTI)

    Yang) - Department of Geological Sciences, University of Texas at Austin Yeh, T.-C. Jim (T.-C. Jim Yeh) - Department of Hydrology and Water Resources, University ...

  5. Memorandum of Understanding Between the United States Department of Energy and the Washington State Department of Ecology for Development of the Hanford Site Tank Closure and Waste Management EIS ("TC&WM EIS")

    Broader source: Energy.gov [DOE]

    The U.S. Department of Energy (DOE) and Washington State Department of Ecology (Ecology) have mutual responsibilities for accomplishing cleanup of the Hanford Site as well as continuing ongoing...

  6. Assessment of the influences of groundwater colloids on the migration of technetium-99 at the Paducah Gaseous Diffusion Plant Site in Paducah, Kentucky

    SciTech Connect (OSTI)

    Gu, B.; McDonald, J.A.; McCarthy, J.F.; Clausen, J.L.

    1994-07-01

    This short report summarizes the influences of groundwater colloids on the migration/transport of {sup 99}Tc at the Paducah Gaseous Diffusion Plant (PGDP) site in Paducah, Kentucky. Limited data suggest that inorganic colloidal materials (e.g., aluminosilicate clay minerals) may not play a significant role in the retention and transport of Tc. Studies by size fractionation reveal that both Tc and natural organic matter (NOM) are largely present in the <3K fraction. The role of NOM on Tc retention and transport is not conclusive on the basis of this study. However, a literature review suggests that Tc is very likely associated with the groundwater organics. The presence of the organic matter could have increased the solubility and cotransport of Tc at the PGDP site. Further studies, applying such techniques as gel chromatography, size exclusion, and spectroscopy, may be useful to determine the association of organic matter with Tc. If Tc is associated with groundwater organics, appropriate protocols for removal of organic matter associated with Tc may be developed. Time and resources were limited so this study is not comprehensive with respect to the role of mobile organic and inorganic colloidal materials on Tc transport in subsurface soils. The redox conditions (DO) of groundwaters reported may not represent the true groundwater conditions, which could have influenced the association and dissociation of Tc with groundwater colloidal materials. Because Tc concentrations in the groundwater (on the order of nCi/L) at the PGDP site is much lower than the solubility of reduced Tc (IV) (on the order of {approximately}10{sup {minus}8} mol/L or parts per billion), regardless of the redox conditions, Tc will stay in solution phase as TC(IV) or Tc(VII). The mechanisms of adsorption/association vs precipitation must be understood under reduced and low Tc conditions so that strategic plans for remediation of Tc contaminated soils and groundwaters can be developed.

  7. DOE Zero Energy Ready Home: Montlake Modern - Seattle, Washington...

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

    DOE Zero Energy Ready Home Case Study: TC Legend Homes, Bellingham Power House, ... Port Hadlock WA DOE Zero Energy Ready Home Case Study: TC Legend, Seattle, WA, Custom Home

  8. Technetium Reduction and Permanent Sequestration by Abiotic and...

    Office of Scientific and Technical Information (OSTI)

    This project aims to provide a fundamental understanding of the feasibility of immobilization of TcO4- as TcSx in the vadose zone or groundwater by application nano zero-valent ...

  9. Technetium Reduction and Permanent Sequestration by Abiotic and...

    Office of Scientific and Technical Information (OSTI)

    The sulfidebacteria-containing system consistently reduced aqueous pertechnetate rapidly ... Preliminary XAS analysis pointed to a mixture of Tc-O and Tc-S binding in the abiotic ...

  10. Preparation of high specific activity technetium-96

    DOE Patents [OSTI]

    Mausner, Leonard F.; Srivastava, Suresh C.; Prach, Thomas

    1992-01-01

    The present invention relates to a method of producing Tc-96 from the proton irradiation of a rhodium target and a technique for isolating under remote hot cell conditions the Tc-96 from the proton irradiated target.

  11. U.S. DEPARTMENT OF ENERGY BIOENERGY TECHNOLOGIES OFFICE

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

    TC Bio-oil Pathways R&D May 20-24, 2013 Melissa Klembara Technology Manager 2 | Bioenergy ... cases are being developed for TC Bio-oil Pathways to gasoline, diesel, and jet fuel ...

  12. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    CreatorsAuthors contains: "Department of Physics and TcSUH, University of Houston, ... NbCoSb Huang, Lihong ; Department of Physics and TcSUH, University of Houston, ...

  13. Technetium Retention During LAW Vitrification

    Office of Environmental Management (EM)

    (1% I) for LAWE7H (AN-102, high organics) * 18% Tc (22% I) for LAWE3 (AP-101, high K) * Sugar most effective organic reductant for Tc and I retention * 15-20% absolute increase...

  14. HIPed Tailored Ceramic Waste Forms for the Immobilization of...

    Office of Scientific and Technical Information (OSTI)

    Experimental data on the immobilization of Tc in titanate ceramics containing up to 40wt% TcO2 are also be presented. Authors: Melody L. Carter ; Martin W. A. Stewart ; Eric R. ...

  15. Tank Closure and Waste Management Environmental Impact Statement...

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

    Energy Post Office Box 1178 Richland, WA 99352 Attention: TC & WM EIS Email: TC&WMEIS@saic.com Fax: 1-888-785-2865 Telephone and voicemail: 1-888-829-6347 For general information ...

  16. Notices

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

    ... Mary Beth Burandt, NEPA Document Manager, Office of River Protection, U.S. Department of Energy, P.O. Box 1178, Richland, Washington 99352, Email: TC&WMEIS@saic.com. The Final TC & ...

  17. Spinning Chen Zhou1, a), Kewei Sun3, Frederick E. Pinkerton2...

    Office of Scientific and Technical Information (OSTI)

    ... Fig. 3 (a) and (b) show the hard magnetic properties and Tc as a function of Co substitution y. For Co substitution range discussed in this study, Tc has a near linear dependence on Co ...

  18. RAP Meeting Transcribed Flipcharts

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

    on TC & WM EIS Page 1 January * DST AY-102 update (Dirk) o Assumptions communication, lessons learned (PIC) * TC & WM EIS o Were previous HAB comments addressed? Do we need new...

  19. The Geochemistry of Technetium: A Summary of the Behavior of an Artificial Element in the Natural Environment

    SciTech Connect (OSTI)

    Icenhower, Jonathan P.; Qafoku, Nikolla; Martin, Wayne J.; Zachara, John M.

    2008-12-01

    Interest in the chemistry of technetium has only increased since its discovery in 1937, mainly because of the large and growing inventory of 99Tc generated during fission of 235U, its environmental mobility in oxidizing conditions, and its potential radiotoxicity. For every ton of enriched uranium fuel (3% 235U) that is consumed at a typical burn-up rate, nearly 1 kg of 99Tc is generated. Thus, the mass of 99Tc produced since 1993 has nearly quadrupled, and will likely to continue to increase if more emphasis is placed on nuclear power to slow the accumulation of atmospheric greenhouse gases. In order to gain a comprehensive understanding of the interaction of 99Tc and the natural environment, we review the sources of 99Tc in the nuclear fuel cycle, its chemical properties, radiochemistry, and biogeochemical behavior. We include an evaluation of the use of Re as a chemical analog of Tc, as well as a summary of the redox potential, thermodynamics, sorption, colloidal behavior, and interaction of humic substances with Tc, and the potential for re-oxidation and remobilization of Tc(IV). What emerges is a more complicated picture of Tc behavior than that of an easily tractable transition of Tc(VII) to Tc(IV) with consequent immobilization. Reducing conditions (+200 to +100 mV Eh) are generally thought necessary to cause reduction of Tc(VII) to Tc(IV), but far more important are the presence of reducing agents, such as Fe(II) sorbed onto mineral grains. Catalysis of Tc(VII) by surface-mediated Fe(II) will bring the mobile Tc(VII) species to a lower oxidation state and will form the relatively insoluble Tc(IV)O2∙nH2O, but even as a solid, equilibrium concentrations of aqueous Tc are nearly a factor of 20× above the EPA set drinking water standards. However, sequestration of Tc(IV) into Fe(III)-bearing phases, such as goethite or other hydrous oxyhydroxides of iron, may ameliorate concerns over the mobility of Tc. Further, the outcome of many studies on terrestrial and

  20. Model for Energy Supply System Alternatives and their General...

    Open Energy Info (EERE)

    Resource Type: Softwaremodeling tools Website: www-tc.iaea.orgtcwebabouttcstrategyThematicpdfpresentationsener References: Overview of IAEA PESS Models 1 "MESSAGE...

  1. Financial Analysis of Electric Sector Expansion Plans (FINPLAN...

    Open Energy Info (EERE)

    Resource Type: Softwaremodeling tools Website: www-tc.iaea.orgtcwebabouttcstrategyThematicpdfpresentationsener References: Overview of IAEA PESS Models 1 "In...

  2. Magnetic coherence in cuprate superconductors (Journal Article...

    Office of Scientific and Technical Information (OSTI)

    Subject: 36 MATERIALS SCIENCE; HIGH-TC SUPERCONDUCTORS; LANTHANUM OXIDES; STRONTIUM OXIDES; COPPER OXIDES; COHERENCE LENGTH; NEUTRON DIFFRACTION; MAGNETIZATION; MAGNETIC ...

  3. Spectroscopic Evidence for the Phase Competition between the Pseudogap and

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

    High-Tc Superconductivity | Stanford Synchrotron Radiation Lightsource Spectroscopic Evidence for the Phase Competition between the Pseudogap and High-Tc Superconductivity Friday, January 30, 2015 Figure 1 Figure 1 (a) Temperature dependence of the ARPES spectra at the antinode of optimally-doped Bi2212. (b) - (d) Singularities at Tc in the spectral weight as a spectroscopic evidence of phase competition. High-transition-temperature (Tc) superconductivity is one of the most intriguing

  4. Estimating Radiation Risk from Total Effective Dose Equivalent...

    National Nuclear Security Administration (NNSA)

    0 Tc 0.37 No. 1Tj 5.25 0 TD 0.098 Tc 0 Tw (No.) Tj 15.755 -13.5 TD 0.3to Tw ( ) Tj 5.25 0 TD F1 10.5 Tf -0.1925 Tc 0 5 Report 0 1Tj 5.25 0 TD 0.098 Tc 0 Tw 8No. 7 0 TD -0.IRRPC,

  5. Equipment | The Ames Laboratory

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

    Hydrogen Analyzer Hot Vacuum Extraction System Leco CS-444 Carbon/Sulfur Determinator Leco TC-436 Nitrogen/Oxygen Determinator

  6. Tornado Climatology of the Contiguous United States (NURG/CR...

    National Nuclear Security Administration (NNSA)

    0 >76 Tc765 Tf0 Ts0.000 Tc(0) TjETBT3 Tr0.000 0.000 0.000 rg376.800 540.960 Td0.000 Tw100.756 TzF Tc765 Tf0 0 0 0 0 0 0 1...

  7. An investigation of groundwater organics, soil minerals, and activated carbon on the complexation, adsorption, and separation of technetium-99

    SciTech Connect (OSTI)

    Gu, B.; Dowlen, K.E.

    1996-01-01

    This report summarizes studies on the interactions of technetium-99 (Tc) with different organic compounds and soil minerals under both oxidizing and reducing conditions. The report is divided into four parts and includes (1) effect of natural organic matter (NOM) on the complexation and solubility of Tc, (2) complexation between Tc and trichloroethylene (TCE) in aqueous solutions, (3) adsorption of Tc on soil samples from Paducah Gaseous Diffusion Plant (PGDP), and (4) adsorption and separation of Tc on activated carbon. Various experimental techniques were applied to characterize and identify Tc complexation with organic compounds and TCE, including liquid-liquid extraction, membrane filtration, size exclusion, and gel chromatography. Results indicate, within the experimental error, Tc (as pertechnetate, TcO{sub 4}) did not appear to form complexes with groundwater or natural organic matter under both atmospheric and reducing conditions. However, Tc can form complexes with certain organic compounds or specific functional groups such as salicylate. Tc did not appear to form complexes with TCE in aqueous solution.Both liquid-liquid extraction and high performance liquid chromatography (HPLC) gave no indication Tc was complexed with TCE. The correlations between Tc and TCE concentrations in monitoring wells at PGDP may be a coincidence because TCE was commonly used as a decontamination reagent. Once TCE and Tc entered the groundwater, they behaved similarly because both TcO{sub 4}{sup {minus}} and TCE are poorly adsorbed by soils. An effective remediation technique to remove TcO{sub 4}{sup {minus}} from PGDP contaminated groundwater is needed. One possibility is the use of an activated carbon adsorption technique developed in this study.

  8. Evolution of technetium speciation in reducing grout

    SciTech Connect (OSTI)

    Lukens, Wayne W.; Bucher, Jerome J.; Shuh, David K.; Edelstein,Norman M.

    2003-11-24

    Cementitious waste forms (CWFs) are an important component of the strategy to immobilize high-level nuclear waste resulting from plutonium production by the U.S. Department of Energy (DOE). Technetium (99Tc) is an abundant fission product of particular concern in CWFs due to the high solubility and mobility of pertechnetate, TcO4-, the stable form of technetium in aerobic environments. CWFs can more effectively immobilize 99Tc if they contain additives that reduce mobile TcO4- to immobile Tc(IV) species. Leaching of 99Tc from reducing CWFs that contain Tc(IV) is much slower than for CWFs containing TcO4-. Previous X-ray absorption fine structure (XAFS) studies showed that the Tc(IV) species were oxidized to TcO4- in reducing grout samples prepared on a laboratory scale. Whether the oxidizer was atmospheric O2 or NO3- in the waste simulant was not determined. In actual CWFs, rapid oxidation of Tc(IV) by NO3- would be a concern, whereas oxidation by atmospheric O2 would be of less concern due to the slow diffusion and reaction of O2 with the reducing CWF. To address this uncertainty, two series of reducing grouts were prepared using TcO4- containing waste simulants with and without NO3-. In the first series of samples, the TcO4- was completely reduced using Na2S, and the samples were placed in containers that permitted O2 diffusion. In these samples, all of the technetium was initially present as aTc(IV) sulfide compound, TcSx, which was characterized using extended X-ray absorption fine structure (EXAFS) spectroscopy, and is likely Tc2S7. The TcSx initially present in the grout samples was steadily oxidized over 4 years. In the second series of samples, all of the TcO4- was not initially reduced, and the grout samples were placed in airtight containers. In these samples, the remaining TcO4- continued to be reduced as the samples aged, presumably due to the presence of reducing blast furnace slag. When samples in the second series were exposed to atmosphere, the

  9. Investigation of Technetium Redox Cycling in FRC Background Sediments using EXAFS and Gamma Camera Imaging

    SciTech Connect (OSTI)

    Lloyd, J.R.; McBeth, J.M.; Lear, G.; Morris, K.; Burke, I.T.; Livens, F.R.; Ellis, B.; Lawson, R.

    2006-04-05

    Technetium-99 is a priority pollutant at numerous DOE sites, due to its long half-life (2.1 x 105 years), high mobility as Tc(VII) in oxic waters, and bioavailability as a sulfate analogue. {sup 99}Tc is far less mobile under anaerobic conditions, forming insoluble Tc(IV) precipitates. As anaerobic microorganisms can reduce soluble Tc(VII) to insoluble Tc(IV), microbial metabolism may have the potential to treat sediments and waters contaminated with Tc. Baseline studies of fundamental mechanisms of Tc(VII) bioreduction and precipitation (reviewed by Lloyd et al., 2005, in press) have generally used pure cultures of metal-reducing bacteria, in order to develop conceptual models for the biogeochemical cycling of {sup 99}Tc. There is, however, comparatively little known about interactions of metal-reducing bacteria with environmentally relevant trace concentrations of {sup 99}Tc, against a more complex biogeochemical background provided by mixed microbial communities in aquifer sediments. The objective of this project is to probe the site specific biogeochemical conditions that control the mobility of {sup 99}Tc at the US DOE Field Research Center Site (FRC; Oak Ridge, Tennessee). This information is required for the rational design of in situ bioremediation strategies for technetium-contaminated subsurface environments. We are using a combination of geochemical, mineralogical, microbiological and spectroscopic techniques to determine the solubility and phase associations of {sup 99}Tc in FRC sediments, and characterize the underpinning biogeochemical controls.

  10. Oxidative Remobilization of Technetium Sequestered by Sulfide-Transformed Nano Zerovalent Iron

    SciTech Connect (OSTI)

    Fan, Dimin; Anitori, Roberto; Tebo, Bradley M.; Tratnyek, P. G.; Lezama Pacheco, Juan S.; Kukkadapu, Ravi K.; Kovarik, Libor; Engelhard, Mark H.; Bowden, Mark E.

    2014-06-02

    The dissolution of Tc(IV) sulfide and concurrent transformation of sulfidated ZVI during 2 oxidation were examined. Kinetic data obtained with 10 mL batch reactors showed that Tc(VII) 3 reduced by sulfidated nZVI has significantly slower reoxidation rates than Tc(VII) reduced by 4 nZVI only. In a 50 mL batch reactor, initial inhibition of Tc(IV) dissolution was apparent and 5 lasted until 120 hours at S/Fe = 0.112, presumably due to the redox buffer capacity of FeS. This 6 is evidenced by the parallel trends in oxidation-reduction potentials (ORP) and Tc dissolution 7 kinetics. M?ssbauer spectra and micro X-ray diffraction of S/Fe = 0.112 suggested the 8 persistence of FeS after 24-h oxidation although X-ray photoelectron spectroscopy indicated 9 substantial surface oxidation. After 120-h oxidation, all characterizations showed complete 10 oxidation of FeS, which further indicates that FeS inhibits Tc oxidation. X-ray absorption 11 spectroscopy for S/Fe = 0.011 showed significantly increasing percentage of TcS2 in the solid 12 phase after 24-h oxidation, indicating TcS2 is more resistant to oxidation than TcO2. At S/Fe = 13 0.112, the XAS results revealed significant transformation of Tc speciation from TcS2 to TcO2 14 after 120-h oxidation at S/Fe = 0.112. Given that no apparent Tc dissolution occurred during this 15 period, the speciation transformation might play a secondary role in hindering Tc oxidation, 16 especially as redox buffer capacity approached depletion.

  11. Effects of aqueous-soluble organic compounds on the removal of selected radionuclides from high-level waste part I: Distribution of Sr, Cs, and Tc onto 18 absorbers from an irradiated, organic-containing leachate simulant for Hanford Tank 101-SY

    SciTech Connect (OSTI)

    Marsh, S.F.; Svitra, Z.V.; Bowen, S.M.

    1995-01-01

    Many of the radioactive waste storage tanks at U.S. Department of Energy facilities contain organic compounds that have been degraded by radiolysis and chemical reactions. In this investigation, we measured the effect of some aqueous-soluble organic compounds on the sorption of strontium, cesium, and technetium onto 18 absorbers that offer high sorption of strontium from organic-free solutions. For our test solution we used a leachate from a simulated slurry for Hanford Tank 101-SY that initially contained ethylenediaminetetraacetic acid (EDTA) and then was gamma-irradiated to 34 Mrads. We measured distribution coefficients (Kds) for each element/absorber combination for dynamic contact periods of 30 min, 2 h, and 6 h to obtain information about sorption kinetics. To facilitate comparisons, we include Kd values for these same element/absorber combinations from three organic-free simulant solutions. The Kd values for strontium sorption from the simulant that contained the degraded organics usually decreased by large factors, whereas the Kd values for cesium and technetium sorption were relatively unaffected.

  12. Comment on "Radiocarbon Calibration Curve Spanning 0 to 50,000 Years B.P. Based on Paired 230Th/234U/238U and 14C Dates on Pristine Corals" by R.G. Fairbanks, R. A. Mortlock, T.-C. Chiu, L. Cao, A. Kaplan, T. P. Guilderson, T. W. Fairbanks, A. L. Bloom, P

    SciTech Connect (OSTI)

    Reimer, P J; Baillie, M L; Bard, E; Beck, J W; Blackwell, P G; Buck, C E; Burr, G S; Edwards, R L; Friedrich, M; Guilderson, T P; Hogg, A G; Hughen, K A; Kromer, B; McCormac, G; Manning, S; Reimer, R W; Southon, J R; Stuiver, M; der Plicht, J v; Weyhenmeyer, C E

    2005-10-02

    Radiocarbon calibration curves are essential for converting radiocarbon dated chronologies to the calendar timescale. Prior to the 1980's numerous differently derived calibration curves based on radiocarbon ages of known age material were in use, resulting in ''apples and oranges'' comparisons between various records (Klein et al., 1982), further complicated by until then unappreciated inter-laboratory variations (International Study Group, 1982). The solution was to produce an internationally-agreed calibration curve based on carefully screened data with updates at 4-6 year intervals (Klein et al., 1982; Stuiver and Reimer, 1986; Stuiver and Reimer, 1993; Stuiver et al., 1998). The IntCal working group has continued this tradition with the active participation of researchers who produced the records that were considered for incorporation into the current, internationally-ratified calibration curves, IntCal04, SHCal04, and Marine04, for Northern Hemisphere terrestrial, Southern Hemisphere terrestrial, and marine samples, respectively (Reimer et al., 2004; Hughen et al., 2004; McCormac et al., 2004). Fairbanks et al. (2005), accompanied by a more technical paper, Chiu et al. (2005), and an introductory comment, Adkins (2005), recently published a ''calibration curve spanning 0-50,000 years''. Fairbanks et al. (2005) and Chiu et al. (2005) have made a significant contribution to the database on which the IntCal04 and Marine04 calibration curves are based. These authors have now taken the further step to derive their own radiocarbon calibration extending to 50,000 cal BP, which they claim is superior to that generated by the IntCal working group. In their papers, these authors are strongly critical of the IntCal calibration efforts for what they claim to be inadequate screening and sample pretreatment methods. While these criticisms may ultimately be helpful in identifying a better set of protocols, we feel that there are also several erroneous and misleading statements made by these authors which require a response by the IntCal working group. Furthermore, we would like to comment on the sample selection criteria, pretreatment methods, and statistical methods utilized by Fairbanks et al. in derivation of their own radiocarbon calibration.

  13. Gas-Phase Treatment of Technetium in the Vadose Zone at the Hanford Site Central Plateau

    SciTech Connect (OSTI)

    Truex, Michael J.; Szecsody, James E.; Zhong, Lirong; Qafoku, Nikolla

    2014-09-01

    Technetium-99 (Tc-99) is present in the vadose zone of the Hanford Central Plateau and is a concern with respect to the protection of groundwater. The persistence, limited natural attenuation mechanisms, and geochemical behavior of Tc-99 in oxic vadose zone environments must be considered in developing effective alternatives for remediation. This report describes a new in situ geochemical manipulation technique for decreasing Tc-99 mobility using a combination of geochemical Tc-99 reduction with hydrogen sulfide gas and induced sediment mineral dissolution with ammonia vapor, which create conditions for deposition of stable precipitates that decrease the mobility of Tc-99. Laboratory experiments were conducted to examine changes in Tc-99 mobility in vadose zone sediment samples to evaluate the effectiveness of the treatment under a variety of operational and sediment conditions.

  14. Technetium-99m generator system

    DOE Patents [OSTI]

    Mirzadeh, Saed (Knoxville, TN); Knapp, Jr., Furn F. (Oak Ridge, TN); Collins, Emory D. (Knoxville, TN)

    1998-01-01

    A .sup.99 Mo/.sup.99m Tc generator system includes a sorbent column loaded with a composition containing .sup.99 Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating .sup.99m Tc eluted from the sorbent column. A method of preparing a concentrated solution of .sup.99m Tc includes the general steps of: a. providing a sorbent column loaded with a composition containing .sup.99 Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; b. eluting the sorbent column with a salt solution to elute .sup.99m Tc from the sorbent and to trap and concentrate the eluted .sup.99m Tc on the ion-exchange column; and c. eluting the concentrated .sup.99m Tc from the ion-exchange column with a solution comprising a reductive complexing agent.

  15. Technetium-99m generator system

    DOE Patents [OSTI]

    Mirzadeh, S.; Knapp, F.F. Jr.; Collins, E.D.

    1998-06-30

    A {sup 99}Mo/{sup 99m}Tc generator system includes a sorbent column loaded with a composition containing {sup 99}Mo. The sorbent column has an effluent end in fluid communication with an anion-exchange column for concentrating {sup 99m}Tc eluted from the sorbent column. A method of preparing a concentrated solution of {sup 99m}Tc includes the general steps of: (a) providing a sorbent column loaded with a composition containing {sup 99}Mo, the sorbent column having an effluent end in fluid communication with an anion-exchange column; (b) eluting the sorbent column with a salt solution to elute {sup 99m}Tc from the sorbent and to trap and concentrate the eluted {sup 99m}Tc on the ion-exchange column; and (c) eluting the concentrated {sup 99m}Tc from the ion-exchange column with a solution comprising a reductive complexing agent. 1 fig.

  16. Anomalous Fermi-Surface Dependent Pairing in a Self-Doped High...

    Office of Scientific and Technical Information (OSTI)

    Subject: 36 MATERIALS SCIENCE; FERMI LEVEL; HIGH-TC SUPERCONDUCTORS; VALENCE; BARIUM OXIDES; CALCIUM OXIDES; COPPER OXIDES; BARIUM FLUORIDES; CALCIUM FLUORIDES; COPPER FLUORIDES; ...

  17. Anomalous Fermi-Surface Dependent Pairing in a Self-DopedHigh...

    Office of Scientific and Technical Information (OSTI)

    mechanism:the van Hove singularity and the antiferromagnetic (pia, pia)scattering. ... Subject: 75; FERMI LEVEL; HIGH-TC SUPERCONDUCTORS; SCATTERING; SHAPE; SINGULARITY; ...

  18. Search for: All records | DOE PAGES

    Office of Scientific and Technical Information (OSTI)

    ... Evidence for a new excitation at the interface between a high- T c superconductor and a ... high critical-temperature (Tc 85 K) superconductortopological insulator ...

  19. Burkina Faso-IAEA Cooperation | Open Energy Information

    Open Energy Info (EERE)

    Agency Sector Energy Topics Background analysis Website http:www-tc.iaea.orgtcwebt Program Start 2009 Country Burkina Faso Western Africa References IAEA Project...

  20. Mauritania-IAEA Cooperation | Open Energy Information

    Open Energy Info (EERE)

    Agency Sector Energy Topics Background analysis Website http:www-tc.iaea.orgtcwebt Country Mauritania Western Africa References IAEA project database1 IAEA is working...

  1. Sudan-IAEA Cooperation | Open Energy Information

    Open Energy Info (EERE)

    Agency Sector Energy Topics Background analysis Website http:www-tc.iaea.orgtcwebt Program Start 2007 Country Sudan Northern Africa References IAEA project database1...

  2. Nigeria-IAEA Energy Planning | Open Energy Information

    Open Energy Info (EERE)

    Agency Sector Energy Topics Background analysis Website http:www-tc.iaea.orgtcwebt Program Start 2005 Country Nigeria Western Africa References IAEA project database1...

  3. South Africa-IAEA Energy Planning | Open Energy Information

    Open Energy Info (EERE)

    Agency Sector Energy Topics Background analysis Website http:www-tc.iaea.orgtcwebt Country South Africa Southern Africa References IAEA Project Database1 IAEA is working...

  4. Malawi-IAEA Cooperation | Open Energy Information

    Open Energy Info (EERE)

    Agency Sector Energy Topics Background analysis Website http:www-tc.iaea.orgtcwebt Country Malawi Eastern Africa References IAEA project database1 IAEA is working with...

  5. Niger-IAEA Cooperation | Open Energy Information

    Open Energy Info (EERE)

    Agency Sector Energy Topics Background analysis Website http:www-tc.iaea.orgtcwebt Program Start 2007 Country Niger Western Africa References IAEA Project Database1 IAEA...

  6. Double-sided reel-to-reel metal-organic chemical vapor deposition...

    Office of Scientific and Technical Information (OSTI)

    Subject: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; BARIUM OXIDES; CHEMICAL VAPOR DEPOSITION; COPPER OXIDES; CRITICAL CURRENT; HIGH-TC SUPERCONDUCTORS; ...

  7. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... (United States) Naval Petroleum and Oil Shale Reserves ... Office of Groundwater and Soil Remediation Office of ... for remediation of Tc-contaminated groundwater whereby ...

  8. Watching a Liquid-Crystal Helix Unwind

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

    Temperature dependence of the helical half-pitch scattering profile. Top: Heating from room temperature (RT) to the B4-phase critical temperature (TC 142 C). The peak...

  9. Department

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

    BUSINESS (WOSB) CONCERNS 4. HISTORICALLY BLACK COLLEGES AND UNIVERSITIES (HBCU) AND ... LARGE BUSINESS CONCERNS tc. TOTAL Name: Scott Harrison Whole Dollars Percent 98,430,119 ...

  10. Nuclear Waste Program Quarterly Report July 1, 2003 - September...

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

    Ecology's Perspective on the Draft TC & WM EIS Suzanne Dahl Nuclear Waste Program Washington State Department of Ecology Topics Decisions the Draft EIS supports Cooperating ...

  11. Ultrafast charge localization in a stripe-phase nickelate (Journal...

    Office of Scientific and Technical Information (OSTI)

    e.g. fluctuating charge stripes whose role in high-Tc superconductivity is under debate. ... Subject: 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; 36 MATERIALS ...

  12. Tank Closure and Waste Management Environmental Impact Statement...

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

    1 APPENDIX V RECHARGE SENSITIVITY ANALYSIS In the Draft Tank Closure and Waste Management Environmental Impact Statement for the Hanford Site, Richland, Washington (Draft TC & WM...

  13. Microsoft Word - Settlement Agreement - FINAL - 01-06-061.doc

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

    (DOE) and the Washington State Department of Ecology's ... involving the Hanford Solid Waste EIS. The overarching ... participate in the preparation of the TC&WM EIS as ...

  14. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    ... Full Text Available April 2008 Compensated electron and hole pickets in an underdoped high Tc superconductor Harrison, Neil ; Altarawneh, Moaz M ; Mielke, Charles H ; Sebastian, ...

  15. Two-Phase Westward Encroachment of Basin and Range Extension...

    Open Energy Info (EERE)

    Authors Benjamin E. Surpless, Daniel F. Stockli, Trevor A. Dumitru and Elizabeth L. Miller Published Journal Tectonics, 012002 DOI 10.10292000TC001257 Online Internet link for...

  16. PowerPoint Presentation

    Office of Environmental Management (EM)

    "moly") * "Molybdenum-99 is the parent isotope of technetium-99m ( 99m Tc) - 99 Mo is ... development and commercialization of the medical radioisotope molybdenum-99 (Mo-99) ...

  17. IAEA-Botswana Cooperation | Open Energy Information

    Open Energy Info (EERE)

    Website http:www-tc.iaea.orgtcwebt Program Start 2009 Country Botswana Southern Africa References IAEA Project Database1 IAEA is working with Botswana on Supporting...

  18. Frederic Laquai Seminar: Photocurrent Generation in Low-Bandgap...

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

    ... In: G. Gurzadyan, G. Lanzani, C. Soci, T.C. Sum (Ed.): Ultrafast Dynamics in Molecules, Nanostructures and Interfaces, World Scientific - Series in Optics and Photonics - Vol. 8 ...

  19. Search for: All records | SciTech Connect

    Office of Scientific and Technical Information (OSTI)

    (77) copper oxides (73) high-tc superconductors (62) strontium oxides (55) chalcogenides (51) oxides (49) superconductors (48) oxygen compounds (47) alkaline earth ...

  20. Rhenium Solubility in Borosilicate Nuclear Waste Glass: Implications...

    Office of Scientific and Technical Information (OSTI)

    In this context, the present article reports on the solubilityretention of rhenium, a nonradioactive surrogate for 99Tc, in a LAW borosilicate glass. Due to the radioactive nature ...

  1. Microsoft Word - finalMOU-4-signature1.doc

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

    in place for the Tank Closure Environmental Impact Statement (TC-EIS) effective March 25, 2003. ... V. PROCEDURES ECOLOGY Ecology will notify the DOE document manager of any ...

  2. Using magnetic fields to understand high-temperature superconductivity

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

    (high-Tc) superconductivity has been the issue as to whether a quantum critical point-a special doping value where quantum fluctuations lead to strong...

  3. DOE/ORO-2467 Cleanup Progress Annual Report

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

    ... to remove flush and fuel salt at MSRE ... could theoretically cause a nuclear criticality to occur. ... the Tc-99 area would have spent weeks cutting out ...

  4. Tank Closure and Waste Management Environmental Impact Statement...

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

    Hanford Site, Richland, Washington (Final TC & WM EIS) U.S. Department of Energy (DOE) Foreword DOE appreciates the efforts of the Washington State Department of Ecology (Ecology)...

  5. ALSNews Vol. 326

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

    Two Phase Transitions Make a High-Temperature Superconductor Three research groups joined forces to show that high- temperature (high-Tc) cuprate superconductors undergo two phase...

  6. News Archive | Department of Energy

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

    Environmental Impact Statement for the Hanford Site, Richland, Washington (Final TC & WM EIS, DOEEIS-0391, December 2012). With regard to those wastes that, in the future,...

  7. EIS-0391: Notice to Extend Scoping Period | Department of Energy

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

    Management Environmental Impact Statement for the Hanford Site, Richland, Washington (TC & WM EIS) and rescheduling the public scoping meetings. PDF icon EIS-0391-NOI-scop-2006....

  8. Highly Selective Colorimetric and Luminescence Response of a...

    Office of Scientific and Technical Information (OSTI)

    The spectroscopic response was highly selective and quantitative for aqueous TcO4- among other competing anions. Complimentary Raman spectroscopy and microscopy techniques, ...

  9. Technetium Sorption by Cementitious Materials Under Reducing Conditions

    SciTech Connect (OSTI)

    Kaplan, Daniel I.; Estes, Shanna L.; Powell, Brian A.

    2012-09-28

    The objective of this study was to measure technetium ({sup 99}Tc) sorption to cementitious materials under reducing conditions to simulate Saltstone Disposal Facility conditions. {sup 99}Tc(VII) batch sorption experiments were conducted for 319 days in an inert glovebag with a variety of cementitious materials (aged cement, Vault 2, TR545, and TR547) containing varying amounts of blast furnace slag. Between 154 and 319 days, the {sup 99}Tc aqueous concentrations tended to remain constant and samples amended with different initial {sup 99}Tc concentrations, tended to merge at about 10{sup -9} M for Vault 2 (17% slag) and TR545 (90% slag) and 10{sup -8} M for TR547 (45% slag). This data provided strong evidence that solubility, and not adsorption (K{sub d} values), was controlling aqueous {sup 99}Tc concentrations. Laboratory data superimposed over thermodynamic speciation diagrams further supported the conclusion that solubility, and not adsorption controlled {sup 99}Tc aqueous concentrations. The oxidation state of the aqueous {sup 99}Tc at the end of the sorption experiment was determined by solvent extraction to be almost entirely {sup 99}Tc(VII). The pH of the present system was ~11.8. Previously proposed solubility controlling phases including Tc-sulfides may be present, but do not appear to control solubility. After the 319 day sorption period, the suspensions were removed from the glovebag and a desorption step under oxic conditions was conducted for 20 days by adding oxic, pH-buffered solutions to the suspensions. {sup 99}Tc aqueous concentrations increased by more than an order of magnitude and Eh increased by several hundred millivolts within 24 hours after the introduction of the oxic solutions. These desorption results are consistent with re-oxidation and dissolution/desorption of {sup 99}Tc(IV) phases possibly present in the cementitious materials after the anoxic sorption step of the experiment. Aqueous {sup 99}Tc concentrations continued to increase

  10. Novel Imaging Techniques, Integrated with Mineralogical, Geochemical and Microbiological Characterization to Determine the Biogeochemical Controls....

    SciTech Connect (OSTI)

    Lloyd, Jonathan R.

    2005-06-01

    Tc(VII) will be reduced and precipitated in FRC sediments under anaerobic conditions in batch experiments (progressive microcosms). The complementary microcosm experiments using low pH/nigh nitrate sediments from 3 (near FW 009) are imminent, with the sediment cores already shipped to Manchester. HYPOTHESIS 2. Tc(VII) reduction and precipitation can be visualized in discrete biogeochemical zones in sediment columns using 99mTc and a gamma-camera. Preliminary experiments testing the use of 99mTc as a radiotracer to address hypotheses 2 and 3 have suggested that the 99mTc associates with Fe(II)-bearing sediments in microcosms and stratified columns containing FRC sediments. Initial proof of concept microcosms containing Fe(II)-bearing, microbially-reduced FRC sediments were spiked with 99mTc and imaged using a gamma-camera. In comparison with oxic controls, 99mTc was significantly partitioned in the solid phase in Fe(III)-reducing sediments in batch experiments. Column experiments using FRC background area soil with stratified biogeochemical zones after stimulation of anaerobic processes through nutrient supplementation, suggested that 99mTc transport was retarded through areas of Fe(III) reduction. HYPOTHESIS 3. Sediment-bound reduced 99mTc can be solubilized by perturbations including oxidation coupled to biological nitrate reduction, and mobilization visualized in real-time using a gamma-camera. Significant progress has been made focusing on the impact of nitrate on the biogeochemical behavior of technetium. Additions of 100 mM nitrate to FRC sediment microcosms, which could potentially compete for electrons during metal reduction, inhibited the reduction of both Fe(III) and Tc(VII) completely. Experiments have also addressed the impact of high nitrate concentrations on Fe(II) and Tc(IV) in pre-reduced sediments, showing no significant resolubilization of Tc with the addition of 25 mM nitrate. A parallel set of experiments addressing the impact of aerobic